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18096	https://en.wikipedia.org/wiki/Lavr%20Kornilov	Lavr Kornilov	Lavr Georgiyevich Kornilov (, ; – 13 April 1918) was a Russian military intelligence officer, explorer, and general in the Imperial Russian Army during World War I and the ensuing Russian Civil War. Kornilov was of Siberian Cossack origin. Today he is best remembered for the Kornilov Affair, an unsuccessful endeavor in August/September 1917 that was intended to strengthen Alexander Kerensky's Provisional Government, but which led to Kerensky eventually having Kornilov arrested and charged with attempting a coup d'état, and ultimately undermined Kerensky's rule. Kornilov escaped from jail in November 1917 and subsequently became the military commander of the anti-Bolshevik Volunteer Army which took the charge of anti-Bolshevik opposition in the south of Russia. He and his troops were badly outnumbered in many of their encounters, and he was killed by a shell on 13 April 1918 while laying siege to Ekaterinodar, the capital of the Kuban Soviet Republic. Pre-revolutionary career One story relates how Kornilov was originally born as a Don Cossack Kalmyk named Lorya Dildinov and adopted in Ust-Kamenogorsk, Russian Turkestan (now Kazakhstan) by the family of his mother's brother, the Russian Cossack Khorunzhiy Georgy Nikolayevich Kornilov, whose wife was of Kazakh origin. But his sister wrote that he had not been adopted, had not been a Don Cossack, and that their mother had Polish and Altai Oirot descent. (Though their language was not a Kalmyk/Mongolian one, but because of their Asian race and their history in the Jungar Oirot (Kalmyk) state, Altai Oirots were called Altai Kalmyks by Russians. They were not Muslims or Kazakhs.) But Boris Shaposhnikov, who served with Pyotr Kornilov, the brother of Lavr, in 1903, mentioned the "Kyrgyz" ancestry of their mother - this name was usually used in reference to Kazakhs in 1903. Kornilov's Siberian Cossack father was a friend of Potanin (1835-1920), a prominent figure in the Siberian autonomy movement. Kornilov entered military school in Omsk in 1885 and went on to study at the Mikhailovsky Artillery School in St. Petersburg in 1889. In August 1892 he was assigned as a lieutenant to the Turkestan Military District, where he led several exploration missions in Eastern Turkestan, Afghanistan and Persia, learned several Central Asian languages, and wrote detailed reports about his observations. Kornilov returned to St. Petersburg to attend the Mykolayiv General Staff Academy and graduated as a captain in 1897. Again refusing a posting at St. Peterburg, he returned to the Turkestan Military District, where he resumed his duties as a military intelligence officer. Among his missions at this post was an attempt at traveling incognito to British India in 1904, though he was quickly discovered and subsequently kept under close surveillance. During the Russo-Japanese War of 1904-1905 Kornilov became the Chief of staff of the 1st Infantry Brigade, and was heavily involved in the Battle of Sandepu (January 1905) and the Battle of Mukden (February/March 1905). He was awarded the Order of St. George (4th class) for bravery and promoted to the rank of colonel. Following the end of the war, Kornilov served as military attache in China from 1907 to 1911. He studied the Chinese language, travelled extensively (researching data on the history, traditions and customs of the Chinese, which he intended to use as material for a book about life in contemporary China), and regularly sent detailed reports to the General Staff and Foreign Ministry. Kornilov paid much attention to the prospects of cooperation between Russia and China in the Far East and met with the future president of China, Chiang Kai-shek. In 1910 Kornilov was recalled from Beijing but remained in St. Petersburg for only five months before departing for western Mongolia and Kashgar to examine the military situation along China's border with Russia. On 2 February 1911 he became Commander of the 8th Infantry Regiment of Estonia and was later appointed commander of the 9th Siberian Rifle Division, stationed in Vladivostok. In 1914, at the start of World War I, Kornilov was appointed commander of the 48th Infantry Division, which saw combat in Galicia and the Carpathians. In 1915, he was promoted to the rank of major general. During heavy fighting, he was captured by the Austrians in April 1915, when his division became isolated from the rest of the Russian forces. After his capture, Field Marshal Conrad, the commander of the Austro-Hungarian Army, made a point of meeting him in person. As a major general, he was a high-value prisoner of war, but in July 1916 Kornilov managed to escape back to Russia and return to duty. After the abdication of Tsar Nicholas II, he was given command of the Petrograd Military District in March 1917. On 8 March, Kornilov placed the Empress Alexandra and her children under house arrest at the Alexander Palace (Nicholas was still held at Stavka), replacing the Tsar's Escort and Combined Regiments of the Imperial Guard with 300 revolutionary troops. But when the Provisional Government declined to give him the authority he sought to deal with indiscipline, he was transferred at his request to command the Russian Eighth Army. His army inflicted a spectacular defeat on the Austrians, taking ten thousand prisoners - Russia's only notable military success in the year 1917 - though after five days, was forced to retreat. On 24 July, he was appointed commander of the southern front. A week later, he replaced Aleksei Brusilov as Supreme Commander-in-Chief of the Provisional Government's armed forces. Kornilov Affair In the mass discontent following the July Days, the Russian populace grew highly skeptical about the Provisional Government's abilities to alleviate the economic distress and social resentment among the lower classes. Pavel Milyukov, the Kadet leader, describes the situation in Russia in late July as, "Chaos in the army, chaos in foreign policy, chaos in industry and chaos in the nationalist questions".Kornilov, appointed commander-in-chief of the Russian army in July 1917, considered the Petrograd Soviet responsible for the breakdown in the military in recent times and believed that the Provisional Government lacked the power and confidence to dissolve the Petrograd Soviet. Following several ambiguous correspondences between Kornilov and Alexander Kerensky, Kornilov commanded an assault on the Petrograd Soviet. Because the Petrograd Soviet was able to quickly gather a powerful army of workers and soldiers in defence of the Revolution, Kornilov's coup was an abysmal failure, and he was placed under arrest. The Kornilov Affair resulted in significantly increased distrust among Russians towards the Provisional Government. Russian Civil War After the alleged coup collapsed as his troops disintegrated, Kornilov and his fellow conspirators were placed under arrest in the Bykhov jail. On 19 November, a few weeks after the proclamation of Soviet power in Petrograd, they escaped from their confinement (eased by the fact that the jail was guarded by Kornilov's supporters) and made their way to the Don region, which was controlled by the Don Cossacks. Here they linked up with General Mikhail Alekseev. Kornilov became the military commander of the anti-Bolshevik Volunteer Army with Alekseev as the political chief. The Kornilov Shock Detachment of the 8th Army was the most famous and longest-lived volunteer unit in the Russian Imperial Army. It was also the last regiment of the Russian Imperial Army and the first of the Volunteer Army. In late 1917, the Kornilov Shock Regiment, one of the crack units of the Volunteer Army, was named after him, as well as many other autonomous White Army formations, such as the Kuban Cossack Kornilov Horse Regiment. Kornilov's forces became recognizable for their Totenkopf insignia, which appeared on the regiment's flags, pennants, and soldiers' sleeve patches. Even before the Red Army was formed, Lavr Kornilov promised, "the greater the terror, the greater our victories." He vowed that the goals of his forces must be fulfilled even if it was needed "to set fire to half the country and shed the blood of three-quarters of all Russians." In the Don region village of Lezhanka alone, bands of Kornilov's officers killed more than 500 people. On the other hand, Kornilov's adjutant recalled, that the general "loved only the [Russia] itself" and served it for all his life, having no time to think about political systems. The Bolsheviks for him were dangerous traitors, who ruined Russia's unity and had to be stopped. On 24 February 1918, as Rostov and the Don Cossack capital of Novocherkassk fell to the Bolsheviks, Kornilov led the Volunteer Army on the epic 'Ice March' into the empty steppe towards the Kuban. Although badly outnumbered, he escaped destruction from pursuing Bolshevik forces and laid siege to Ekaterinodar, the capital of the Kuban Soviet Republic, on 10 April. However, in the early morning of 13 April, a Soviet shell landed on his farmhouse headquarters and killed him. He was quietly buried in nearby Gnadau (modern day Dolinovskoe). A few days later, when the Bolsheviks gained control of the village, they unearthed Kornilov's coffin, dragged his corpse to the main square and burnt his remains on the local rubbish dump. Memorials In 13 April 2013, a monument to the late General was erected in Krasnodar. Commemoration ceremonies take place with local cossacks, along with Cossacks from Don, Stavropol and Taman. Honours and awards Order of St. Stanislaus, third degree (1901), 2nd degree (1904 and 1906 with swords) Order of St. Anne, 3rd degree (1903) and 2nd degree (6 December 1909) Order of St. George, 4th degree (9 August 1905) and 3rd degree (28 April 1915) Gold Sword for Bravery (9 May 1907) Badge of the 1st Kuban (Ice) campaign (3 October 1918), issued posthumously, No.1 out of 3,689 References Bibliography Asher, Harvey. "The Kornilov Affair: A Reinterpretation." Russian Review (1970) 29#3 pp: 286-300. in JSTOR Grebenkin, I. N. "General L.G. Kornilov: A Rough Sketch for a Character Portrait." Russian Studies in History 56.3 (2017): 188-211. Katkov, George. Russia 1917, the Kornilov Affair: Kerensky and the Break-up of the Russian Army (Longman, 1980) Mawdsley, Evan. The Russian Civil War (2008) Moncure, James A. ed. Research Guide to European Historical Biography: 1450-Present (4 vol 1992) 3:1082-90 White, James D. "The Kornilov affair—a study in counter‐revolution," Europe‐Asia Studies (1968) 20#2 pp 187–205. Yang, Ho-Hwan. "Different Ways of Interpreting the Kornilov Affair: A Review of George Katkov's The Kornilov Affair: Kerensky and the Break-up of the Russian Army, London and New York: Longman, 1980" The SNU Journal of Education Research (1993) pp 17–28. online External links 1870 births 1918 deaths People from Oskemen People from Semipalatinsk Oblast Commanders-in-chief of the Russian Army Cossacks of the Russian Empire People of the Russian Civil War Recipients of the Gold Sword for Bravery Recipients of the Order of Saint Stanislaus (Russian), 2nd class Recipients of the Order of St. Anna, 2nd class Recipients of the Order of St. George of the Third Degree Russian people of Kazakhstani descent Russian Provisional Government generals Russian military personnel of the Russo-Japanese War Generals of the Russian Empire Anti-communists of the Russian Empire Explorers of the Russian Empire Russian military personnel killed in action Russian military personnel of World War I World War I prisoners of war held by Austria-Hungary Prisoners of war from the Russian Empire Russian Empire escapees White movement generals Kalmyk people Military attachés of the Russian Empire Posthumous executions	[ -0.20850419998168945, 0.5302728414535522, -0.6208803653717041, -0.3773007094860077, 0.021376876160502434, 1.0300804376602173, 0.8356145024299622, -0.1750166267156601, -0.02078678272664547, -0.1701122671365738, -0.6489543914794922, 0.4717745780944824, -0.35069960355758667, 0.391714274883270...
18100	https://en.wikipedia.org/wiki/L.%20L.%20Zamenhof	L. L. Zamenhof	L. L. Zamenhof (15 December 185914 April 1917) was an ophthalmologist who lived for most of his life in Warsaw. He is best known as the creator of Esperanto, the most widely used constructed international auxiliary language. Zamenhof first developed the language in 1873 while still in school. He grew up fascinated by the idea of a world without war. He believed that this could happen with the help of a new international auxiliary language. The language would be a tool to gather people together through neutral, fair, equitable communication. He successfully formed a community that continues today despite the World Wars of the 20th century. Also, it has developed like other languages, through the interaction and creativity of its users. In light of his achievements, and his support of intercultural dialogue, UNESCO selected Zamenhof as one of its eminent personalities of 2017, on the 100th anniversary of his death. Biography Early years Zamenhof was born on 15 December 1859, the son of Mark Zamenhof and Rozalia Zamenhof (), in the multi-ethnic city of Belostok in the Russian Empire (now Białystok in Poland). At that time the city was in the Grodno Governorate of the Russian Empire as a result of the 1807 Treaties of Tilsit. His parents were of Litvak Jewish descent. This group inhabited the former Grand Duchy of Lithuania. He appears to have been natively bilingual in Yiddish and Russian. His father was a teacher of German and French. From him, Zamenhof learned German, French and Hebrew. He also spoke some major languages of Białystok: Polish, Yiddish, Belarusian, and German. Polish became the native language of his children in Warsaw. In school he studied the classical languages Latin, Greek, Hebrew, and Aramaic. He later learned some English, though in his own words not very well. He had an interest in Lithuanian and Italian and learned Volapük when it came out in 1880. By that point his international language project was already well developed. In addition to the Yiddish-speaking Jewish majority, the population of Białystok included Roman Catholic Poles and Eastern Orthodox Russians (mainly government officials), with smaller groups of Belarusians, Germans and other ethnic groups. Zamenhof was saddened and frustrated by the many quarrels among these groups. He supposed that the main reason for the hate and prejudice lay in the mutual misunderstanding caused by the lack of a common language. If such a language existed, Zamenhof postulated, it could play the role of a neutral communication tool between people of different ethnic and linguistic backgrounds. As a student at secondary school in Warsaw, Zamenhof attempted to create an international language with a grammar that was rich, but complex. When he later studied English, he decided that the international language must have a simpler grammar. Apart from his parents' native languages Russian and Yiddish and his adopted language Polish, his projects were also aided by his mastery of German, a good passive understanding of Latin, Hebrew and French, and a basic knowledge of Greek, English and Italian. By 1878, his project Lingwe uniwersala was finished. However, Zamenhof was too young then to publish his work. Soon after graduation he began to study medicine, first in Moscow, and later in Warsaw. In 1885, Zamenhof graduated from university and began his practice as a doctor in Veisiejai. After 1886 he worked as an ophthalmologist in Płock and Vienna. While healing people there, he continued to work on his project of an international language. For two years he tried to raise funds to publish a booklet describing the language, until he received the financial help from his future wife's father. In 1887, the book titled Международный язык. Предисловие и полный учебникъ (International language: Introduction and complete textbook) was published in Russian under the pseudonym "Doktoro Esperanto" (Doctor Hoper, or literally "Doctor One Who Hopes"). Zamenhof initially called his language "Lingvo internacia" (international language), but those who learned it began to call it Esperanto after his pseudonym, and this soon became the official name for the language. For Zamenhof, this language, far from being merely a communication tool, was a way to promote peaceful coexistence between people of different cultures. Work on Yiddish language and Jewish issues In 1879 Zamenhof wrote the first grammar of Yiddish. It was partly published years later in the Yiddish magazine Lebn un visnshaft. The complete original Russian text of this manuscript was only published in 1982, with parallel Esperanto translation by Adolf Holzhaus, in L. Zamenhof, provo de gramatiko de novjuda lingvo (An attempt at a grammar of neo-Jewish language), Helsinki, pp. 9–36. In this work, not only does he provide a review of Yiddish grammar, but also proposes its transition to the Latin script and other orthographic innovations. In the same period Zamenhof wrote some other works in Yiddish, including perhaps the first survey of Yiddish poetics (see p. 50 in the above-cited book). In 1882 a wave of pogroms within the Russian Empire, including Congress Poland, motivated Zamenhof to take part in the early Zionist movement, the Hibbat Zion. He left the movement in 1887, and in 1901 published a statement in Russian with the title Hillelism, in which he argued that the Zionist project could not solve the problems of the Jewish people. In 1914 he declined an invitation to join a new organization of Jewish Esperantists, the TEHA. In his letter to the organizers, he said, "I am profoundly convinced that every nationalism offers humanity only the greatest unhappiness .... It is true that the nationalism of oppressed peoples – as a natural self-defensive reaction – is much more excusable than the nationalism of peoples who oppress; but, if the nationalism of the strong is ignoble, the nationalism of the weak is imprudent; both give birth to and support each other ...." The Hebrew Bible is among the many works that Zamenhof translated into Esperanto. Zamenhof died in Warsaw on 14 April 1917, possibly of a heart attack, and was buried at the Okopowa Street Jewish Cemetery. The farewell speech was delivered by the chief rabbi and preacher of the Great Synagogue in Warsaw, Samuel Abraham Poznański, who said: "There will be a time where the Polish soil and nation will understand what fame gave this great son of God to his homeland." Family Zamenhof and his wife Klara Silbernik raised three children, a son, Adam, and two daughters, Zofia and Lidia. All three were murdered in the Holocaust. Lidia Zamenhof in particular took a keen interest in Esperanto, and as an adult became a teacher of the language, traveling through Europe and to America to teach classes in it. Through her friendship with Martha Root, Lidia accepted Bahá'u'lláh and became a member of the Baháʼí Faith. As one of its social principles, the Baháʼí Faith teaches that an auxiliary world language should be selected by the representatives of all the world's nations. Zamenhof's grandson, Louis-Christophe Zaleski-Zamenhof (Adam's son), lived in France from the 1960s until his death in 2019. As of 2020 Louis-Christophe's daughter, Margaret Zaleski-Zamenhof, is active in the Esperanto movement. Religious philosophy Besides his linguistic work, Zamenhof published a religious philosophy he called Homaranismo (the term in Esperanto, usually rendered as "humanitism" in English, sometimes rendered loosely as humanitarianism or humanism), based on the principles and teachings of Hillel the Elder. He said of Homaranismo: "It is indeed the object of my whole life. I would give up everything for it." Name Zamenhof came from a multilingual area. His name is variously transliterated, depending on the language: English: – English prononciation: Esperanto: – French: – German: – Hebrew: – Hebrew translitteration: Eli'ezer Ludwig Zamenhof Lithuanian: Polish: – Russian: – Russian translitteration: Lyudvik Lazar' (Leyzer) Markovich Zamengof Yiddish: – Yiddish translitteration: Leyzer "Levi" Zamenhof Born into an Ashkenazi family, at his birth Zamenhof was given the common Hebrew name Eliezer by his parents, the equivalent of the English Lazarus. However as the area was a part of the Russian empire at the time, his name was recorded on his birth certificate as Leyzer Zamengov, using the Yiddish form of the forename and a russified version of his surname; many later Russian language documents also include the patronymic Markovich « son of Mark » (in reference to his father, Markus), as is the custom in the language. His family name is of German origin and was originally written Samenhof; this was later transcribed into Yiddish as , then re-romanized back as Zamenhof. The change of the initial letter from « S » to « Z » is not unusual, as in German an initial « s » is pronounced . In his adolescence he used both the Yiddish Leyzer and the Russian Lazar when writing his first name. While at university, Zamenhof began using the Russian name Lyudovik (also transcribed Ludovic or translated as Ludwig) in place of Lazar, possibly in honor of Francis Lodwick, who in 1652 had published an early conlang proposal. When his brother Leon became a doctor and started signing his name "Dr L. Zamenhof", Zamenhof reclaimed his birth name Lazar and from 1901 signed his name "Dr L. L. Zamenhof" to avoid confusion with his brother. The two L's do not seem to have specifically represented either name, and the order Ludwik Lejzer is a modern convention. Honours and namesakes In 1905 Zamenhof received the Légion d'honneur for creating Esperanto. In 1910, Zamenhof was first nominated for the Nobel Peace Prize, by four British Members of Parliament (including James O'Grady and Philip Snowden) and Professor Stanley Lane Poole. (The Prize was instead awarded to the International Peace Bureau.) Ultimately Zamenhof was nominated 12 times for the Nobel Peace Prize. On the occasion of the fifth Universala Kongreso de Esperanto in Barcelona, Zamenhof was made a Commander of the Order of Isabella the Catholic by King Alfonso XIII of Spain. A monument or place linked to Zamenhof or Esperanto is known as a Zamenhof-Esperanto object (or ZEO). The minor planet 1462 Zamenhof is named in his honour. It was discovered on 6 February 1938 by Yrjö Väisälä. There is also a minor planet named in honour of Esperanto (1421 Esperanto). Hundreds of city streets, parks, and bridges worldwide have also been named after Zamenhof. In Lithuania, the best-known Zamenhof Street is in Kaunas, where he lived and owned a house for some time. There are others in Poland, the United Kingdom, France, Hungary, Croatia, the Czech Republic, Spain (mostly in Catalonia), Italy, Israel, Belgium and Brazil. There are Zamenhof Hills in Hungary and Brazil, and a Zamenhof Island in the Danube. In some Israeli cities, street signs identify Esperanto's creator and give his birth and death dates, but refer to him solely by his Jewish name Eliezer (a variant of which, El'azar, is the origin of Lazarus). Zamenhof is honoured as a deity by the Japanese religion Oomoto, which encourages the use of Esperanto among its followers. Also, a genus of lichen has been named Zamenhofia in his honour. Russian writer Nikolai Afrikanovich Borovko, who lived in Odessa, together with Vladimir Gernet, founded a branch of the first official Esperanto society Esrero in Russia. In the years 1896-97 N.A. Borovko became its chairman. A monument to L. Zamenhof was installed in Odessa in an ordinary residential courtyard. Esperantist sculptor Nikolai Vasilyevich Blazhkov lived in this house, who in the early 1960s brought a sculptural portrait into the courtyard, because the customs authorities did not allow the sculpture to be sent to the Esperanto Congress in Vienna. In Gothenburg, Sweden a public square is named Esperantoplatsen. In Italy, a few streets are named after Esperanto, including Largo Esperanto in Pisa. In 1959, UNESCO honoured Zamenhof in the occasion of his centenary. In 2015 it decided to support the celebration of the 100th anniversary of his death. His birthday, 15 December, is celebrated annually as Zamenhof Day by users of Esperanto. On 15 December 2009, Esperanto's green-starred flag flew on the Google homepage to commemorate Zamenhof's 150th birthday. The house of the Zamenhof family and a monument to Zamenhof are sites on the Jewish Heritage Trail in Białystok, which was opened in June 2008 by volunteers at The University of Białystok Foundation. Białystok is also home to the Ludwik Zamenhof Centre. In 1960, Esperanto summer schools were established in Stoke-on-Trent in the United Kingdom by the Esperanto Association of Britain (EAB), which began to provide lessons and promote the language locally. There is a road named after Zamenhof in the city: Zamenhof Grove. As Dr. Zamenhof was born on 15 December 1859, the Esperanto Society of New York gathers every December to celebrate Zamenhofa Tago (Zamenhof Day in Esperanto). Partial bibliography Original works Unua Libro, 1887 (First Book) Dua Libro, 1888 (Second Book) Hilelismo – propono pri solvo de la hebrea demando, 1901 (Hillelism: A Project in Response to the Jewish Question) Esenco kaj estonteco de la ideo de lingvo internacia, 1903 (Essence and Future of the Idea of an International Language) Fundamenta Krestomatio de la Lingvo Esperanto, 1903 (Basic Anthology of the Esperanto Language) Fundamento de Esperanto, 1905 (Foundation of Esperanto) Declaration of Boulogne, 1905 Homaranismo, 1913 (Humanitism) Periodicals La Esperantisto, 1889–1895 (The Esperantist) Lingvo Internacia, 1895–1914 (International Language) La Revuo, 1906–1914 (The Review) Poems "Al la fratoj" ("To the Brothers") "Ho, mia kor'" ("Oh, My Heart") "La Espero" ("The Hope") "La vojo" ("The Way") "Mia penso" ("My Thought") Translations Hamleto, Reĝido de Danujo (Hamlet, Prince of Denmark) by William Shakespeare Ifigenio en Taŭrido (Iphigenia in Tauris) by Johann Wolfgang von Goethe La batalo de l' vivo (The Battle of Life) by Charles Dickens La rabistoj (The Robbers) by Friedrich Schiller La revizoro (The Government Inspector) by Nikolai Gogol Malnova Testamento (parts of the Old Testament) Marta by Eliza Orzeszkowa See also List of peace activists Notes References External links 1859 births 1917 deaths 19th-century translators Articles containing video clips Commanders of the Order of Isabella the Catholic Commandeurs of the Légion d'honneur Constructed language creators Esperanto history Esperanto literature Esperanto speaking Jews Grammarians of Yiddish Inventors of the Russian Empire Jews of the Russian Empire Linguists from Poland People from Belostoksky Uyezd People from Białystok Polish Esperantists Polish inventors Polish Ashkenazi Jews Polish ophthalmologists Translators of Johann Wolfgang von Goethe Translators of the Bible into Esperanto Translators of William Shakespeare	[ -0.05548449978232384, 0.15599125623703003, -0.08583259582519531, -0.7167460322380066, 0.015726251527667046, 0.41187766194343567, 0.036879245191812515, -0.06382432579994202, -0.29217728972435, -0.5035446286201477, -0.3271956741809845, 0.09302455186843872, 0.004807324148714542, 0.58727872371...
18102	https://en.wikipedia.org/wiki/Linear%20map	Linear map	In mathematics, and more specifically in linear algebra, a linear map (also called a linear mapping, linear transformation, vector space homomorphism, or in some contexts linear function) is a mapping between two vector spaces that preserves the operations of vector addition and scalar multiplication. The same names and the same definition are also used for the more general case of modules over a ring; see Module homomorphism. If a linear map is a bijection then it is called a . In the case where , a linear map is called a (linear) endomorphism. Sometimes the term linear operator refers to this case, but the term "linear operator" can have different meanings for different conventions: for example, it can be used to emphasize that and are real vector spaces (not necessarily with ), or it can be used to emphasize that is a function space, which is a common convention in functional analysis. Sometimes the term linear function has the same meaning as linear map, while in analysis it does not. A linear map from V to W always maps the origin of V to the origin of W. Moreover, it maps linear subspaces in V onto linear subspaces in W (possibly of a lower dimension); for example, it maps a plane through the origin in V to either a plane through the origin in W, a line through the origin in W, or just the origin in W. Linear maps can often be represented as matrices, and simple examples include rotation and reflection linear transformations. In the language of category theory, linear maps are the morphisms of vector spaces. Definition and first consequences Let and be vector spaces over the same field . A function is said to be a linear map if for any two vectors and any scalar the following two conditions are satisfied: Additivity / operation of addition Homogeneity of degree 1 / operation of scalar multiplication Thus, a linear map is said to be operation preserving. In other words, it does not matter whether the linear map is applied before (the right hand sides of the above examples) or after (the left hand sides of the examples) the operations of addition and scalar multiplication. By the associativity of the addition operation denoted as +, for any vectors and scalars the following equality holds: Thus a linear map is one which preserves linear combinations. Denoting the zero elements of the vector spaces and by and respectively, it follows that Let and in the equation for homogeneity of degree 1: A linear map with viewed as a one-dimensional vector space over itself is called a linear functional. These statements generalize to any left-module over a ring without modification, and to any right-module upon reversing of the scalar multiplication. Examples A prototypical example that gives linear maps their name is a function , of which the graph is a line through the origin. More generally, any homothety where centered in the origin of a vector space is a linear map. The zero map between two vector spaces (over the same field) is linear. The identity map on any module is a linear operator. For real numbers, the map is not linear. For real numbers, the map is not linear (but is an affine transformation). If is a real matrix, then defines a linear map from to by sending a column vector to the column vector . Conversely, any linear map between finite-dimensional vector spaces can be represented in this manner; see the , below. If is an isometry between real normed spaces such that then is a linear map. This result is not necessarily true for complex normed space. Differentiation defines a linear map from the space of all differentiable functions to the space of all functions. It also defines a linear operator on the space of all smooth functions (a linear operator is a linear endomorphism, that is, a linear map with the same domain and codomain). An example is A definite integral over some interval is a linear map from the space of all real-valued integrable functions on to . For example, An indefinite integral (or antiderivative) with a fixed integration starting point defines a linear map from the space of all real-valued integrable functions on to the space of all real-valued, differentiable functions on . Without a fixed starting point, the antiderivative maps to the quotient space of the differentiable functions by the linear space of constant functions. If and are finite-dimensional vector spaces over a field , of respective dimensions and , then the function that maps linear maps to matrices in the way described in (below) is a linear map, and even a linear isomorphism. The expected value of a random variable (which is in fact a function, and as such a element of a vector space) is linear, as for random variables and we have and , but the variance of a random variable is not linear. Linear extensions Often, a linear map is constructed by defining it on a subset of a vector space and then to the linear span of the domain. A of a function refers to an extension of to some vector space that is a linear map. Suppose and are vector spaces and is a function defined on some subset Then can be extended to a linear map if and only if whenever is an integer, are scalars, and are vectors such that then necessarily If a linear extension of exists then the linear extension is unique and holds for all and as above. If is linearly independent then every function into any vector space has a linear extension to a (linear) map (the converse is also true). For example, if and then the assignment and can be linearly extended from the linearly independent set of vectors to a linear map on The unique linear extension is the map that sends to Every (scalar-valued) linear functional defined on a vector subspace of a real or complex vector space has a linear extension to all of Indeed, the Hahn–Banach dominated extension theorem even guarantees that when this linear functional is dominated by some given seminorm (meaning that holds for all in the domain of ) then there exists a linear extension to that is also dominated by Matrices If and are finite-dimensional vector spaces and a basis is defined for each vector space, then every linear map from to can be represented by a matrix. This is useful because it allows concrete calculations. Matrices yield examples of linear maps: if is a real matrix, then describes a linear map (see Euclidean space). Let be a basis for . Then every vector is uniquely determined by the coefficients in the field : If is a linear map, which implies that the function f is entirely determined by the vectors . Now let be a basis for . Then we can represent each vector as Thus, the function is entirely determined by the values of . If we put these values into an matrix , then we can conveniently use it to compute the vector output of for any vector in . To get , every column of is a vector corresponding to as defined above. To define it more clearly, for some column that corresponds to the mapping , where is the matrix of . In other words, every column has a corresponding vector whose coordinates are the elements of column . A single linear map may be represented by many matrices. This is because the values of the elements of a matrix depend on the bases chosen. The matrices of a linear transformation can be represented visually: Matrix for relative to : Matrix for relative to : Transition matrix from to : Transition matrix from to : Such that starting in the bottom left corner and looking for the bottom right corner , one would left-multiply—that is, . The equivalent method would be the "longer" method going clockwise from the same point such that is left-multiplied with , or . Examples in two dimensions In two-dimensional space R2 linear maps are described by 2 × 2 matrices. These are some examples: rotation by 90 degrees counterclockwise: by an angle θ counterclockwise: reflection through the x axis: through the y axis: through a line making an angle θ with the origin: scaling by 2 in all directions: horizontal shear mapping: squeeze mapping: projection onto the y axis: Vector space of linear maps The composition of linear maps is linear: if and are linear, then so is their composition . It follows from this that the class of all vector spaces over a given field K, together with K-linear maps as morphisms, forms a category. The inverse of a linear map, when defined, is again a linear map. If and are linear, then so is their pointwise sum , which is defined by . If is linear and is an element of the ground field , then the map , defined by , is also linear. Thus the set of linear maps from to itself forms a vector space over , sometimes denoted . Furthermore, in the case that , this vector space, denoted , is an associative algebra under composition of maps, since the composition of two linear maps is again a linear map, and the composition of maps is always associative. This case is discussed in more detail below. Given again the finite-dimensional case, if bases have been chosen, then the composition of linear maps corresponds to the matrix multiplication, the addition of linear maps corresponds to the matrix addition, and the multiplication of linear maps with scalars corresponds to the multiplication of matrices with scalars. Endomorphisms and automorphisms A linear transformation is an endomorphism of ; the set of all such endomorphisms together with addition, composition and scalar multiplication as defined above forms an associative algebra with identity element over the field (and in particular a ring). The multiplicative identity element of this algebra is the identity map . An endomorphism of that is also an isomorphism is called an automorphism of . The composition of two automorphisms is again an automorphism, and the set of all automorphisms of forms a group, the automorphism group of which is denoted by or . Since the automorphisms are precisely those endomorphisms which possess inverses under composition, is the group of units in the ring . If has finite dimension , then is isomorphic to the associative algebra of all matrices with entries in . The automorphism group of is isomorphic to the general linear group of all invertible matrices with entries in . Kernel, image and the rank–nullity theorem If is linear, we define the kernel and the image or range of by is a subspace of and is a subspace of . The following dimension formula is known as the rank–nullity theorem: The number is also called the rank of and written as , or sometimes, ; the number is called the nullity of and written as or . If and are finite-dimensional, bases have been chosen and is represented by the matrix , then the rank and nullity of are equal to the rank and nullity of the matrix , respectively. Cokernel A subtler invariant of a linear transformation is the cokernel, which is defined as This is the dual notion to the kernel: just as the kernel is a subspace of the domain, the co-kernel is a quotient space of the target. Formally, one has the exact sequence These can be interpreted thus: given a linear equation f(v) = w to solve, the kernel is the space of solutions to the homogeneous equation f(v) = 0, and its dimension is the number of degrees of freedom in the space of solutions, if it is not empty; the co-kernel is the space of constraints that the solutions must satisfy, and its dimension is the maximal number of independent constraints. The dimension of the co-kernel and the dimension of the image (the rank) add up to the dimension of the target space. For finite dimensions, this means that the dimension of the quotient space W/f(V) is the dimension of the target space minus the dimension of the image. As a simple example, consider the map f: R2 → R2, given by f(x, y) = (0, y). Then for an equation f(x, y) = (a, b) to have a solution, we must have a = 0 (one constraint), and in that case the solution space is (x, b) or equivalently stated, (0, b) + (x, 0), (one degree of freedom). The kernel may be expressed as the subspace (x, 0) < V: the value of x is the freedom in a solution – while the cokernel may be expressed via the map W → R, : given a vector (a, b), the value of a is the obstruction to there being a solution. An example illustrating the infinite-dimensional case is afforded by the map f: R∞ → R∞, with b1 = 0 and bn + 1 = an for n > 0. Its image consists of all sequences with first element 0, and thus its cokernel consists of the classes of sequences with identical first element. Thus, whereas its kernel has dimension 0 (it maps only the zero sequence to the zero sequence), its co-kernel has dimension 1. Since the domain and the target space are the same, the rank and the dimension of the kernel add up to the same sum as the rank and the dimension of the co-kernel (), but in the infinite-dimensional case it cannot be inferred that the kernel and the co-kernel of an endomorphism have the same dimension (0 ≠ 1). The reverse situation obtains for the map h: R∞ → R∞, with cn = an + 1. Its image is the entire target space, and hence its co-kernel has dimension 0, but since it maps all sequences in which only the first element is non-zero to the zero sequence, its kernel has dimension 1. Index For a linear operator with finite-dimensional kernel and co-kernel, one may define index as: namely the degrees of freedom minus the number of constraints. For a transformation between finite-dimensional vector spaces, this is just the difference dim(V) − dim(W), by rank–nullity. This gives an indication of how many solutions or how many constraints one has: if mapping from a larger space to a smaller one, the map may be onto, and thus will have degrees of freedom even without constraints. Conversely, if mapping from a smaller space to a larger one, the map cannot be onto, and thus one will have constraints even without degrees of freedom. The index of an operator is precisely the Euler characteristic of the 2-term complex 0 → V → W → 0. In operator theory, the index of Fredholm operators is an object of study, with a major result being the Atiyah–Singer index theorem. Algebraic classifications of linear transformations No classification of linear maps could be exhaustive. The following incomplete list enumerates some important classifications that do not require any additional structure on the vector space. Let and denote vector spaces over a field and let be a linear map. Monomorphism is said to be injective or a monomorphism if any of the following equivalent conditions are true: is one-to-one as a map of sets. is monic or left-cancellable, which is to say, for any vector space and any pair of linear maps and , the equation implies . is left-invertible, which is to say there exists a linear map such that is the identity map on . Epimorphism is said to be surjective or an epimorphism if any of the following equivalent conditions are true: is onto as a map of sets. is epic or right-cancellable, which is to say, for any vector space and any pair of linear maps and , the equation implies . is right-invertible, which is to say there exists a linear map such that is the identity map on . Isomorphism is said to be an isomorphism if it is both left- and right-invertible. This is equivalent to being both one-to-one and onto (a bijection of sets) or also to being both epic and monic, and so being a bimorphism. If is an endomorphism, then: If, for some positive integer , the -th iterate of , , is identically zero, then is said to be nilpotent. If , then is said to be idempotent If , where is some scalar, then is said to be a scaling transformation or scalar multiplication map; see scalar matrix. Change of basis Given a linear map which is an endomorphism whose matrix is A, in the basis B of the space it transforms vector coordinates [u] as [v] = A[u]. As vectors change with the inverse of B (vectors are contravariant) its inverse transformation is [v] = B[v']. Substituting this in the first expression hence Therefore, the matrix in the new basis is A′ = B−1AB, being B the matrix of the given basis. Therefore, linear maps are said to be 1-co- 1-contra-variant objects, or type (1, 1) tensors. Continuity A linear transformation between topological vector spaces, for example normed spaces, may be continuous. If its domain and codomain are the same, it will then be a continuous linear operator. A linear operator on a normed linear space is continuous if and only if it is bounded, for example, when the domain is finite-dimensional. An infinite-dimensional domain may have discontinuous linear operators. An example of an unbounded, hence discontinuous, linear transformation is differentiation on the space of smooth functions equipped with the supremum norm (a function with small values can have a derivative with large values, while the derivative of 0 is 0). For a specific example, converges to 0, but its derivative does not, so differentiation is not continuous at 0 (and by a variation of this argument, it is not continuous anywhere). Applications A specific application of linear maps is for geometric transformations, such as those performed in computer graphics, where the translation, rotation and scaling of 2D or 3D objects is performed by the use of a transformation matrix. Linear mappings also are used as a mechanism for describing change: for example in calculus correspond to derivatives; or in relativity, used as a device to keep track of the local transformations of reference frames. Another application of these transformations is in compiler optimizations of nested-loop code, and in parallelizing compiler techniques. See also Notes Bibliography Abstract algebra Functions and mappings Transformation (function)	[ -0.5076335668563843, -0.0952841192483902, -0.11393269896507263, 0.009649095125496387, -0.17273034155368805, 0.18541359901428223, -0.4803025722503662, 0.10699177533388138, -0.11936720460653305, -0.7441609501838684, -0.5289800763130188, 0.34299641847610474, -0.3664436936378479, 0.06102934852...
18103	https://en.wikipedia.org/wiki/Leyden%20jar	Leyden jar	A Leyden jar (or Leiden jar, or archaically, sometimes Kleistian jar) is an electrical component which stores a high-voltage electric charge (from an external source) between electrical conductors on the inside and outside of a glass jar. It typically consists of a glass jar with metal foil cemented to the inside and the outside surfaces, and a metal terminal projecting vertically through the jar lid to make contact with the inner foil. It was the original form of the capacitor (also called a condenser). Its invention was a discovery made independently by German cleric Ewald Georg von Kleist on 11 October 1745 and by Dutch scientist Pieter van Musschenbroek of Leiden (Leyden), Netherlands in 1745–1746. The invention was named after the city. The Leyden jar was used to conduct many early experiments in electricity, and its discovery was of fundamental importance in the study of electrostatics. It was the first means of accumulating and preserving electric charge in large quantities that could be discharged at the experimenter's will, thus overcoming a significant limit to early research into electrical conduction. Leyden jars are still used in education to demonstrate the principles of electrostatics. History The Ancient Greeks already knew that pieces of amber could attract lightweight particles after being rubbed. The amber becomes electrified by the triboelectric effect, mechanical separation of charge in a dielectric material. The Greek word for amber is ἤλεκτρον ("ēlektron") and is the origin of the word "electricity". Thales of Miletus, a pre-Socratic philosopher is thought to have accidentally commented on the phenomena of electrostatic charging, due to his belief that even lifeless things have a soul in them, hence the popular analogy of the spark. Around 1650, Otto von Guericke built a crude electrostatic generator: a sulphur ball that rotated on a shaft. When Guericke held his hand against the ball and turned the shaft quickly, a static electric charge built up. This experiment inspired the development of several forms of "friction machines", that greatly helped in the study of electricity. The Leyden jar was effectively discovered independently by two parties: German deacon Ewald Georg von Kleist, who made the first discovery, and Dutch scientists Pieter van Musschenbroek and Andreas Cunaeus, who figured out how it worked only when held in the hand. The Leyden jar is a high-voltage device; it is estimated that at a maximum the early Leyden jars could be charged to 20,000 to 60,000 volts. The center rod electrode has a metal ball on the end to prevent leakage of the charge into the air by corona discharge. It was first used in electrostatics experiments, and later in high-voltage equipment such as spark-gap radio transmitters and electrotherapy machines. Von Kleist Ewald Georg von Kleist discovered the immense storage capability of the Leyden jar while working under a theory that saw electricity as a fluid, and hoped a glass jar filled with alcohol would "capture" this fluid. He was the deacon at the cathedral of Camin in Pomerania, a region now divided between Germany and Poland. In October 1745, von Kleist tried to accumulate electricity in a small medicine bottle filled with alcohol with a nail inserted in the cork. He was following up on an experiment developed by Georg Matthias Bose where electricity had been sent through water to set alcoholic spirits alight. He attempted to charge the bottle from a large prime conductor (invented by Bose) suspended above his friction machine. Kleist was convinced that a substantial electric charge could be collected and held within the glass which he knew would provide an obstacle to the escape of the 'fluid'. He received a significant shock from the device when he accidentally touched the nail through the cork while still cradling the bottle in his other hand. He communicated his results to at least five different electrical experimenters, in several letters from November 1745 to March 1746, but did not receive any confirmation that they had repeated his results, until April 1746. Polish-Lithuanian physicist Daniel Gralath learned about Kleist's experiment from seeing Kleist's letter to Paul Swietlicki, written in November 1745. After Gralath's failed first attempt to reproduce the experiment in December 1745, he wrote to Kleist for more information (and was told that the experiment would work better if the tube half-filled with alcohol was used). Gralath (in collaboration with ) succeeded in getting the intended effect on 5 March 1746, holding a small glass medicine bottle with a nail inside in one hand, moving it close to an electrostatic generator, and then moving the other hand close to the nail. Kleist didn't understand the significance of his conducting hand holding the bottle — and both he and his correspondents were loath to hold the device when told that the shock could throw them across the room. It took some time before Kleist's student associates at Leyden worked out that the hand provided an essential element. Musschenbroek and Cunaeus The Leyden jar's invention was long credited to Pieter van Musschenbroek, the physics professor at Leiden University, who also ran a family foundry which cast brass cannonettes, and a small business (De Oosterse Lamp – "The Eastern Lamp") which made scientific and medical instruments for the new university courses in physics and for scientific gentlemen keen to establish their own 'cabinets' of curiosities and instruments. Ewald Kleist is credited with first using the fluid analogy for electricity and demonstrated this to Bose by drawing sparks from water with his finger. Like Kleist, Musschenbroek was also interested in, and attempting to repeat, Bose's experiment. During this time, Andreas Cunaeus, a lawyer, came to learn about this experiment from visiting Musschenbroek's laboratory and Cunaeus attempted to duplicate the experiment at home with household items. Using a glass of beer, Cunaeus was unable to make it work. Cunaeus was the first to discover that such an experimental setup could deliver a severe shock when he held his jar in his hand while charging it rather than placing it on an insulated stand, not realizing that was the standard practice, thus making himself part of the circuit. He reported his procedure and experience to Swiss-Dutch natural philosopher Jean-Nicolas-Sebastian Allamand, Musschenbroek's colleague. Allamand and Musschenbroek also received severe shocks. Musschenbroek communicated the experiment in a letter from 20 January 1746 to French entomologist René Antoine Ferchault de Réaumur, who was Musschenbroek's appointed correspondent at the Paris Academy. Abbé Jean-Antoine Nollet read this report, confirmed the experiment, and then read Musschenbroek's letter in a public meeting of the Paris Academy in April 1746 (translating from Latin to French). Musschenbroek's outlet in France for the sale of his company's 'cabinet' devices was the Abbé Nollet (who started building and selling duplicate instruments in 1735). Nollet then gave the electrical storage device the name "Leyden jar" and promoted it as a special type of flask to his market of wealthy men with scientific curiosity. The "Kleistian jar" was therefore promoted as the Leyden jar, and as having been discovered by Pieter van Musschenbroek and his acquaintance Andreas Cunaeus. Musschenbroek, however, never claimed that he had invented it, and some think that Cunaeus was mentioned only to diminish credit to him. Further developments Within months after Musschenbroek's report about how to reliably create a Leyden jar, other electrical researchers were making and experimenting with their own Leyden jars. One of his expressed original interests was to see if the total possible charge could be increased. Johann Heinrich Winckler, whose first experience with a single Leyden jar was reported in a letter to the Royal Society on 29 May 1746, had connected three Leyden jars together in a kind of electrostatic battery on 28 July 1746. In 1746, Abbé Nollet performed two experiments for the edification of King Louis XV of France, in the first of which he discharged a Leyden jar through 180 royal guardsmen, and in the second through a larger number of Carthusian monks; all of whom sprang into the air more or less simultaneously. The opinions of neither the king nor the experimental subjects have been recorded. Daniel Gralath reported in 1747 that in 1746 he had conducted experiments with connecting two or three jars, probably in series. In 1746-1748, Benjamin Franklin experimented with charging Leyden jars in series, and developed a system involving 11 panes of glass with thin lead plates glued on each side, and then connected together. He used the term "electrical battery" to describe his electrostatic battery in a 1749 letter about his electrical research in 1748. It is possible that Franklin's choice of the word battery was inspired by the humorous wordplay at the conclusion of his letter, where he wrote, among other things, about a salute to electrical researchers from a battery of guns. This is the first recorded use of the term electrical battery. The multiple and rapid developments for connecting Leyden jars during the period 1746–1748 resulted in a variety of divergent accounts in secondary literature about who made the first "battery" by connecting Leyden jars, whether they were in series or parallel, and who first used the term "battery". The term was later used for combinations of multiple electrochemical cells, the modern meaning of the term "battery". The Swedish physicist, chemist and meteorologist, Tobern Bergman translated much of Benjamin Franklin's writings on electricity into German and continued to study electrostatic properties. Starting in late 1756, Franz Aepinus, in a complicated interaction of cooperation and independent work with Johan Wilcke, developed an "air condenser", a variation on the Leyden jar, by using air rather than glass as the dielectric. This functioning apparatus, without glass, created a problem for Benjamin Franklin's explanation of the Leyden jar, which maintained that the charge was located in the glass. Beginning in the late 18th century it was used in the Victorian medical field of electrotherapy to treat a variety of diseases by electric shock. By the middle of the 19th century, the Leyden jar had become common enough for writers to assume their readers knew of and understood its basic operation. Around the turn of the century it began to be widely used in spark-gap transmitters and medical electrotherapy equipment. By the early 20th century, improved dielectrics and the need to reduce their size and undesired inductance and resistance for use in the new technology of radio caused the Leyden jar to evolve into the modern compact form of capacitor. Design A typical design consists of a glass jar with conducting tin foil coating the inner and outer surfaces. The foil coatings stop short of the mouth of the jar, to prevent the charge from arcing between the foils. A metal rod electrode projects through the nonconductive stopper at the mouth of the jar, electrically connected by some means (usually a hanging chain) to the inner foil, to allow it to be charged. The jar is charged by an electrostatic generator, or other source of electric charge, connected to the inner electrode while the outer foil is grounded. The inner and outer surfaces of the jar store equal but opposite charges. The original form of the device is just a glass bottle partially filled with water, with a metal wire passing through a cork closing it. The role of the outer plate is provided by the hand of the experimenter. Soon John Bevis found (in 1747) that it was possible to coat the exterior of the jar with metal foil, and he also found that he could achieve the same effect by using a plate of glass with metal foil on both sides. These developments inspired William Watson in the same year to have a jar made with a metal foil lining both inside and outside, dropping the use of water. Early experimenters (such as Benjamin Wilson in 1746) reported that the thinner the dielectric and the greater the surface, the greater the charge that could be accumulated. Further developments in electrostatics revealed that the dielectric material was not essential, but increased the storage capability (capacitance) and prevented arcing between the plates. Two plates separated by a small distance also act as a capacitor, even in a vacuum. Storage of the charge It was initially believed that the charge was stored in the water in early Leyden jars. In the 1700s American statesman and scientist Benjamin Franklin performed extensive investigations of both water-filled and foil Leyden jars, which led him to conclude that the charge was stored in the glass, not in the water. A popular experiment, due to Franklin, which seems to demonstrate this involves taking a jar apart after it has been charged and showing that little charge can be found on the metal plates, and therefore it must be in the dielectric. The first documented instance of this demonstration is in a 1749 letter by Franklin. Franklin designed a "dissectible" Leyden jar (right), which was widely used in demonstrations. The jar is constructed out of a glass cup nested between two fairly snugly fitting metal cups. When the jar is charged with a high voltage and carefully dismantled, it is discovered that all the parts may be freely handled without discharging the jar. If the pieces are re-assembled, a large spark may still be obtained from it. This demonstration appears to suggest that capacitors store their charge inside their dielectric. This theory was taught throughout the 1800s. However, this phenomenon is a special effect caused by the high voltage on the Leyden jar. In the dissectible Leyden jar, charge is transferred to the surface of the glass cup by corona discharge when the jar is disassembled; this is the source of the residual charge after the jar is reassembled. Handling the cup while disassembled does not provide enough contact to remove all the surface charge. Soda glass is hygroscopic and forms a partially conductive coating on its surface, which holds the charge. Addenbrooke (1922) found that in a dissectible jar made of paraffin wax, or glass baked to remove moisture, the charge remained on the metal plates. Zeleny (1944) confirmed these results and observed the corona charge transfer. Quantity of charge Originally, the amount of capacitance was measured in number of 'jars' of a given size, or through the total coated area, assuming reasonably standard thickness and composition of the glass. A typical Leyden jar of one pint size has a capacitance of about 1 nF. Residual charge If a charged Leyden jar is discharged by shorting the inner and outer coatings and left to sit for a few minutes, the jar will recover some of its previous charge, and a second spark can be obtained from it. Often this can be repeated, and a series of 4 or 5 sparks, decreasing in length, can be obtained at intervals. This effect is caused by dielectric absorption. See also Franklin bells Notes References External links Leyden Jar – Interactive Java Tutorial National High Magnetic Field Laboratory Schechner, Sara J.“The Art of Making Leyden Jars and Batteries according to Benjamin Franklin.” eRittenhouse 26 (2015). Science fair project idea. Electrical instruments Capacitors Dielectrics Dutch inventions Energy storage Glass jars Historical scientific instruments Science and technology in the Dutch Republic 1746 introductions 18th-century inventions German inventions	[ 0.2812330424785614, 0.41743630170822144, -0.018644198775291443, 0.13714374601840973, -0.05341307446360588, 0.3261582553386688, 0.010812753811478615, -0.3743288218975067, 0.04157949239015579, 0.07916175574064255, -0.20388801395893097, 0.17876754701137543, -0.011546416208148003, 0.5511063933...
18109	https://en.wikipedia.org/wiki/Lennon%20Wall	Lennon Wall	The Lennon Wall or John Lennon Wall is a wall in Prague, Czech Republic. Since the 1980s this once typical wall has been filled with John Lennon-inspired graffiti, lyrics from Beatles' songs, and designs relating to local and global causes. History and ongoing development Located in a small and secluded square across from the French Embassy, the wall had been decorated by love poems and short messages against the regime since 1960s. It received its first decoration connected to John Lennon, a symbol of freedom, western culture, and political struggle, following the 1980 assassination of John Lennon when an unknown artist painted a single image of the singer-songwriter and some lyrics. In 1988, the wall was a source of irritation for Gustáv Husák's communist regime. Following a short-lived era of democratization and political liberalization known as the Prague Spring, the newly-installed communist government dismantled the reforms, inspiring anger and resistance. Young Czechs wrote their grievances on the wall and, according to a report of the time, this led to a clash between hundreds of students and security police on the nearby Charles Bridge. The liberalization movement these students followed was described as "Lennonism" (not to be confused with "Leninism"), and Czech authorities described participants variously as alcoholic, mentally deranged, sociopathic, and agents of Western free market capitalism. The wall continuously undergoes change, and the original portrait of Lennon is long lost under layers of new paint. Even when the wall was repainted by authorities, by the next day it was again full of poems and flowers. Today, the wall represents a symbol of global ideals such as love and peace. The wall is owned by the Sovereign Military Order of Malta, which allowed the graffiti, and is located at Velkopřevorské náměstí (Grand Priory Square), Malá Strana. On 17 November 2014, the 25th anniversary of the Velvet Revolution, the wall was painted over in pure white by a group of art students, leaving only the text "wall is over" . The Knights of Malta initially filed a criminal complaint for vandalism against the students, which they later retracted after contacting them. The wall mural is still there as of 23 July 2017. And the "Wall is Over" bit has been changed to "War Is Over" from the song Happy Xmas (War Is Over). On 22 April 2019, Earth Day, the action group Extinction Rebellion repainted the entire wall with slogans demanding action from the Czech government on climate change. "KLIMATICKÁ NOUZE" was painted in large block print letters, which reads "climate emergency" in Czech. Members of the public were encouraged to add their own messages during the process, resulting in calls for action painted in several languages. A giant image of a skull was also painted. The repaint was carried out in a manner which allowed some of the existing artwork to be included on the new wall. In July 2019, artists painted a memorial on the wall for Hong Kong democracy activist Marco Leung Ling-kit, who became known as a martyr and a symbol of hope for the 2019 anti-extradition bill protest movement. The image on the wall depicts the yellow raincoat he was wearing during the banner drop that eventually led to a fall from the building, along with some words of solidarity: "Hong Kong, Add oil." On 4 August 2019 it was reported that the wall will be put under CCTV surveillance to block "unlawful graffiti" and combat the swaths of tourists that pass by it every day. In October 2019, the Sovereign Military Order of Malta together with Prague 1 started the reconstruction of the Lennon Wall which lasted until November. They reacted thus to the recent situation of vandalism on the Wall and its surroundings connected to the overtourism which became unbearable this summer. The place should regain its respectable form which was going to be introduced on the occasion of the 30th anniversary of the Velvet Revolution in November as an open-air gallery with new rules. On 7 November 2019, the new face of the Lennon Wall as an open-air gallery was created and introduced to the public. Over 30 Czech and foreign professional artists gathered by the Czech designer Pavel Šťastný painted on the Wall. New rules of the Wall makes spraying no longer allowed, people can leave their messages connected to freedom and love only in the white free zones andy in more sensitive materials than sprays, e.g. pencil, marker or chalk. Cameras and police will monitor the wall to ensure the artistic portion is not defaced. Lennon Walls in Hong Kong During the 2014 democracy protests in Hong Kong, a similar Lennon Wall appeared along the staircase outside of the Hong Kong Central Government Offices. Inspired by the original in Prague, many thousands of people posted colourful post-it notes expressing democratic wishes for Hong Kong. The wall was one of the major arts of the Umbrella Movement. Throughout the several months of occupations and protest, many efforts were made by different groups to ensure physical and digital preservation of the Hong Kong Lennon Wall. Five years later, during the 2019–20 Hong Kong protests, the same wall was again created, with new post-it notes. Within days, dozens of post-it-note Lennon Walls had "blossomed everywhere" (遍地開花) throughout Hong Kong, including on Hong Kong Island itself, Kowloon, the New Territories, and on the many outlying islands. There are even some Lennon Walls located inside government offices, including RTHK and the Policy Innovation and Co-ordination Office. According to a crowd-sourced map of Hong Kong, there are over 150 Lennon Walls throughout the region. On 21 September 2019, police in Hong Kong began tearing down Lennon Walls across the city to remove anti-government statements. Lennon Walls have also appeared outside of Hong Kong in the cities of: Toronto, Vancouver BC, Calgary, Seoul, Tokyo, Berlin, London, Sydney, Manchester, Melbourne, Taipei, and Auckland. See also John Lennon Park — Havana, Cuba Strawberry Fields — Memorial in Central Park NYC Tsoi Wall — a similar wall near Arbat Street in Moscow Lennon Walls of Hong Kong Art of the Umbrella Movement 2019–20 Hong Kong protests Extinction Rebellion List of famous walls References External links Digital Lennon Wall Google Maps location of John Lennon Wall Article about the Lennon Wall in the Erasmuspc World CityPoem collection Book of Lennon Wall Cultural depictions of John Lennon Buildings and structures in Prague Culture in Prague Graffiti and unauthorised signage Tourist attractions in Prague Walls Malá Strana	[ 0.45236343145370483, 0.7020838260650635, -0.19424737989902496, -0.4486260712146759, 0.1901586353778839, 0.12241052836179733, 0.28841912746429443, 0.15938206017017365, -0.42252472043037415, -0.12607266008853912, 0.016233673319220543, -0.439537912607193, -0.2974560558795929, 0.35560101270675...
18110	https://en.wikipedia.org/wiki/Los%20Angeles	Los Angeles	Los Angeles (; ; , , ), often referred to by its initials L.A., is the largest city in California. With a 2020 population of 3,898,747, it is the second-largest city in the United States, following New York City. Los Angeles is known for its Mediterranean climate, ethnic and cultural diversity, Hollywood film industry and sprawling metropolitan area. The City of Los Angeles lies in a basin in Southern California, adjacent to the Pacific Ocean, and extends through the Santa Monica Mountains and into the San Fernando Valley, covering a total of about . It is the seat of Los Angeles County, which is the most populous county in the United States with just over 10 million residents in 2020. Home to the Chumash and Tongva indigenous peoples, the area that became Los Angeles was claimed by Juan Rodríguez Cabrillo for Spain in 1542. The city was founded on September 4, 1781, under Spanish governor Felipe de Neve, on the village of Yaanga. It became a part of Mexico in 1821 following the Mexican War of Independence. In 1848, at the end of the Mexican–American War, Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo, and thus became part of the United States. Los Angeles was incorporated as a municipality on April 4, 1850, five months before California achieved statehood. The discovery of oil in the 1890s brought rapid growth to the city. The city was further expanded with the completion of the Los Angeles Aqueduct in 1913, which delivers water from Eastern California. Los Angeles has a diverse and robust economy, and hosts businesses in a broad range of professional and cultural fields. It also has the busiest container port in the Americas. In 2018, the Los Angeles metropolitan area had a gross metropolitan product of over $1.0 trillion, making it the city with the third-largest GDP in the world, after Tokyo and New York City. Los Angeles hosted the 1932 and 1984 Summer Olympics and will host the 2028 Summer Olympics. History Pre-colonial history The Los Angeles coastal area was settled by the Tongva (Gabrieleños) and Chumash tribes. Los Angeles would eventually be founded on the village of iyáangẚ or Yaanga (written "Yang-na" by the Spanish), meaning "poison oak place." Maritime explorer Juan Rodríguez Cabrillo claimed the area of southern California for the Spanish Empire in 1542 while on an official military exploring expedition moving north along the Pacific coast from earlier colonizing bases of New Spain in Central and South America. Gaspar de Portolà and Franciscan missionary Juan Crespí reached the present site of Los Angeles on August 2, 1769. Spanish rule In 1771, Franciscan friar Junípero Serra directed the building of the Mission San Gabriel Arcángel, the first mission in the area. On September 4, 1781, a group of forty-four settlers known as "Los Pobladores" founded the pueblo they called . The original name of the settlement is disputed; the Guinness Book of World Records rendered it as "El Pueblo de Nuestra Señora la Reina de los Ángeles de Porciúncula"; other sources have shortened or alternate versions of the longer name. The present-day city has the largest Roman Catholic archdiocese in the United States. Two-thirds of the Mexican or (New Spain) settlers were mestizo or mulatto, a mixture of African, indigenous and European ancestry. The settlement remained a small ranch town for decades, but by 1820, the population had increased to about 650 residents. Today, the pueblo is commemorated in the historic district of Los Angeles Pueblo Plaza and Olvera Street, the oldest part of Los Angeles. Mexican rule New Spain achieved its independence from the Spanish Empire in 1821, and the pueblo continued as a part of Mexico. During Mexican rule, Governor Pío Pico made Los Angeles Alta California's regional capital. 1847 to present Mexican rule ended during the Mexican–American War: Americans took control from the Californios after a series of battles, culminating with the signing of the Treaty of Cahuenga on January 13, 1847. Railroads arrived with the completion of the transcontinental Southern Pacific line from New Orleans to Los Angeles in 1876 and the Santa Fe Railroad in 1885. Petroleum was discovered in the city and surrounding area in 1892, and by 1923, the discoveries had helped California become the country's largest oil producer, accounting for about one-quarter of the world's petroleum output. By 1900, the population had grown to more than 102,000, putting pressure on the city's water supply. The completion of the Los Angeles Aqueduct in 1913, under the supervision of William Mulholland, ensured the continued growth of the city. Because of clauses in the city's charter that prevented the City of Los Angeles from selling or providing water from the aqueduct to any area outside its borders, many adjacent cities and communities felt compelled to join Los Angeles. Los Angeles created the first municipal zoning ordinance in the United States. On September 14, 1908, the Los Angeles City Council promulgated residential and industrial land use zones. The new ordinance established three residential zones of a single type, where industrial uses were prohibited. The proscriptions included barns, lumber yards, and any industrial land use employing machine-powered equipment. These laws were enforced against industrial properties after the fact. These prohibitions were in addition to existing activities that were already regulated as nuisances. These included explosives warehousing, gas works, oil drilling, slaughterhouses, and tanneries. Los Angeles City Council also designated seven industrial zones within the city. However, between 1908 and 1915, Los Angeles City Council created various exceptions to the broad proscriptions that applied to these three residential zones, and as a consequence, some industrial uses emerged within them. There are two differences between the 1908 Residence District Ordinance and later zoning laws in the United States. First, the 1908 laws did not establish a comprehensive zoning map as the 1916 New York City Zoning Ordinance did. Second, the residential zones did not distinguish types of housing; they treated apartments, hotels, and detached-single-family housing equally. In 1910, Hollywood merged into Los Angeles, with 10 movie companies already operating in the city at the time. By 1921, more than 80 percent of the world's film industry was concentrated in L.A. The money generated by the industry kept the city insulated from much of the economic loss suffered by the rest of the country during the Great Depression. By 1930, the population surpassed one million. In 1932, the city hosted the Summer Olympics. During World War II, Los Angeles was a major center of wartime manufacturing, such as shipbuilding and aircraft. Calship built hundreds of Liberty Ships and Victory Ships on Terminal Island, and the Los Angeles area was the headquarters of six of the country's major aircraft manufacturers (Douglas Aircraft Company, Hughes Aircraft, Lockheed, North American Aviation, Northrop Corporation, and Vultee). During the war, more aircraft were produced in one year than in all the pre-war years since the Wright brothers flew the first airplane in 1903, combined. Manufacturing in Los Angeles skyrocketed, and as William S. Knudsen, of the National Defense Advisory Commission put it, "We won because we smothered the enemy in an avalanche of production, the like of which he had never seen, nor dreamed possible." In the 1930s–1940s, Los Angeles County was the national leader in agriculture. Following the end of World War II, Los Angeles grew more rapidly than ever, sprawling into the San Fernando Valley. The expansion of the Interstate Highway System during the 1950s and 1960s helped propel suburban growth and signaled the demise of the city's electrified rail system, once the world's largest. As a consequence of World War II, suburban growth, and population density, many amusement parks were built and operated in this area. An example is Beverly Park, which was located at the corner of Beverly Boulevard and La Cienega before being closed and substituted by the Beverly Center. Racial tensions led to the Watts riots in 1965, resulting in 34 deaths and over 1,000 injuries. In 1969, California became the birthplace of the Internet, as the first ARPANET transmission was sent from the University of California, Los Angeles (UCLA) to the Stanford Research Institute in Menlo Park. In 1973, Tom Bradley was elected as the city's first African American mayor, serving for five terms until retiring in 1993. Other events in the city during the 1970s included the Symbionese Liberation Army's South Central standoff in 1974 and the Hillside Stranglers murder cases in 1977–1978. In 1984, the city hosted the Summer Olympic Games for the second time. Despite being boycotted by 14 Communist countries, the 1984 Olympics became more financially successful than any previous, and the second Olympics to turn a profit; the other, according to an analysis of contemporary newspaper reports, was the 1932 Summer Olympics, also held in Los Angeles. Racial tensions erupted on April 29, 1992, with the acquittal by a Simi Valley jury of four Los Angeles Police Department (LAPD) officers captured on videotape beating Rodney King, culminating in large-scale riots. In 1994, the magnitude 6.7 Northridge earthquake shook the city, causing $12.5 billion in damage and 72 deaths. The century ended with the Rampart scandal, one of the most extensive documented cases of police misconduct in American history. In 2002, Mayor James Hahn led the campaign against secession, resulting in voters defeating efforts by the San Fernando Valley and Hollywood to secede from the city. Los Angeles will host the 2028 Summer Olympics and Paralympic Games, making Los Angeles the third city to host the Olympics three times. Pronunciation The English pronunciation of the name of the city has varied. A 1953 article in the journal of the American Name Society asserts that the pronunciation was established following the 1850 incorporation of the city and that since the 1880s the pronunciation emerged out of a trend in California to give places Spanish, or Spanish-sounding, names and pronunciations. In 1908, librarian Charles Fletcher Lummis, who argued for the pronunciation with , reported that there were at least 12 pronunciation variants. In the early 1900s, the Los Angeles Times advocated for pronouncing it Loce AHNG-hayl-ais (), approximating Spanish , by printing the respelling under its masthead for several years. This did not find favor. Since the 1930s, has been most common. In 1934, the United States Board on Geographic Names decreed that this pronunciation be used. This was also endorsed in 1952 by a "jury" appointed by Mayor Fletcher Bowron to devise an official pronunciation. Geography Topography The city of Los Angeles covers a total area of , comprising of land and of water. The city extends for north-south and for east-west. The perimeter of the city is . Los Angeles is both flat and hilly. The highest point in the city proper is Mount Lukens at , located at the northeastern end of the San Fernando Valley. The eastern end of the Santa Monica Mountains stretches from Downtown to the Pacific Ocean and separates the Los Angeles Basin from the San Fernando Valley. Other hilly parts of Los Angeles include the Mt. Washington area north of Downtown, eastern parts such as Boyle Heights, the Crenshaw district around the Baldwin Hills, and the San Pedro district. Surrounding the city are much higher mountains. Immediately to the north lie the San Gabriel Mountains, which is a popular recreation area for Angelenos. Its high point is Mount San Antonio, locally known as Mount Baldy, which reaches . Further afield, the highest point in the Greater Los Angeles area is San Gorgonio Mountain, with a height of . The Los Angeles River, which is largely seasonal, is the primary drainage channel. It was straightened and lined in of concrete by the Army Corps of Engineers to act as a flood control channel. The river begins in the Canoga Park district of the city, flows east from the San Fernando Valley along the north edge of the Santa Monica Mountains, and turns south through the city center, flowing to its mouth in the Port of Long Beach at the Pacific Ocean. The smaller Ballona Creek flows into the Santa Monica Bay at Playa del Rey. Vegetation Los Angeles is rich in native plant species partly because of its diversity of habitats, including beaches, wetlands, and mountains. The most prevalent plant communities are coastal sage scrub, chaparral shrubland, and riparian woodland. Native plants include: the California poppy, matilija poppy, toyon, Ceanothus, Chamise, Coast Live Oak, sycamore, willow and Giant Wildrye. Many of these native species, such as the Los Angeles sunflower, have become so rare as to be considered endangered. Although it is not native to the area, the official tree of Los Angeles is the Coral Tree (Erythrina caffra) and the official flower of Los Angeles is the Bird of Paradise (Strelitzia reginae). Mexican Fan Palms, Canary Island Palms, Queen Palms, Date Palms, and California Fan Palms are common in the Los Angeles area, although only the last is native to California, though still not native to the City of Los Angeles. Geology Los Angeles is subject to earthquakes because of its location on the Pacific Ring of Fire. The geologic instability has produced numerous faults, which cause approximately 10,000 earthquakes annually in Southern California, though most of them are too small to be felt. The strike-slip San Andreas Fault system, which sits at the boundary between the Pacific Plate and the North American Plate, passes through the Los Angeles metropolitan area. The segment of the fault passing through Southern California experiences a major earthquake roughly every 110 to 140 years, and seismologists have warned about the next "big one", as the last major earthquake was the 1857 Fort Tejon earthquake. The Los Angeles basin and metropolitan area are also at risk from blind thrust earthquakes. Major earthquakes that have hit the Los Angeles area include the 1933 Long Beach, 1971 San Fernando, 1987 Whittier Narrows, and the 1994 Northridge events. All but a few are of low intensity and are not felt. The USGS has released the UCERF California earthquake forecast, which models earthquake occurrence in California. Parts of the city are also vulnerable to tsunamis; harbor areas were damaged by waves from Aleutian Islands earthquake in 1946, Valdivia earthquake in 1960, Alaska earthquake in 1964, Chile earthquake in 2010 and Japan earthquake in 2011. Cityscape The city is divided into many different districts and neighborhoods, some of which were incorporated cities that merged with Los Angeles. These neighborhoods were developed piecemeal, and are well-defined enough that the city has signage marking nearly all of them. Overview The city's street patterns generally follow a grid plan, with uniform block lengths and occasional roads that cut across blocks. However, this is complicated by rugged terrain, which has necessitated having different grids for each of the valleys that Los Angeles covers. Major streets are designed to move large volumes of traffic through many parts of the city, many of which are extremely long; Sepulveda Boulevard is long, while Foothill Boulevard is over long, reaching as far east as San Bernardino. Drivers in Los Angeles suffer from one of the worst rush hour periods in the world, according to an annual traffic index by navigation system maker, TomTom. LA drivers spend an additional 92 hours in traffic each year. During the peak rush hour, there is 80% congestion, according to the index. Los Angeles is often characterized by the presence of low-rise buildings, in contrast to New York City. Outside of a few centers such as Downtown, Warner Center, Century City, Koreatown, Miracle Mile, Hollywood, and Westwood, skyscrapers and high-rise buildings are not common in Los Angeles. The few skyscrapers built outside of those areas often stand out above the rest of the surrounding landscape. Most construction is done in separate units, rather than wall-to-wall. That being said, Downtown Los Angeles itself has many buildings over 30 stories, with fourteen over 50 stories, and two over 70 stories, the tallest of which is the Wilshire Grand Center. Also, Los Angeles is increasingly becoming a city of apartments rather than single-family dwellings, especially in the dense inner city and Westside neighborhoods. Climate Los Angeles has a Mediterranean climate (Köppen Csb on the coast and most of downtown, Csa near the metropolitan region to the west), and receives just enough annual precipitation to avoid being classified as a semi-arid climate (BSh). Daytime temperatures are generally temperate all year round. In winter, they average around giving it a tropical feel although it is a few degrees too cool to be a true tropical climate on average due to cool night temperatures. Los Angeles has plenty of sunshine throughout the year, with an average of only 35 days with measurable precipitation annually. Temperatures in the coastal basin exceed on a dozen or so days in the year, from one day a month in April, May, June and November to three days a month in July, August, October and to five days in September. Temperatures in the San Fernando and San Gabriel Valleys are considerably warmer. Temperatures are subject to substantial daily swings; in inland areas the difference between the average daily low and the average daily high is over . The average annual temperature of the sea is , from in January to in August. Hours of sunshine total more than 3,000 per year, from an average of 7 hours of sunshine per day in December to an average of 12 in July. The Los Angeles area is also subject to phenomena typical of a microclimate, causing extreme variations in temperature in close physical proximity to each other. For example, the average July maximum temperature at the Santa Monica Pier is whereas it is in Canoga Park, away. The city, like much of the Southern Californian coast, is subject to a late spring/early summer weather phenomenon called "June Gloom". This involves overcast or foggy skies in the morning that yield to sun by early afternoon. Downtown Los Angeles averages of precipitation annually, mainly occurring between November and March, generally in the form of moderate rain showers, but sometimes as heavy rainfall during winter storms. Rainfall is usually higher in the hills and coastal slopes of the mountains because of orographic uplift. Summer days are usually rainless. Rarely, an incursion of moist air from the south or east can bring brief thunderstorms in late summer, especially to the mountains. The coast gets slightly less rainfall, while the inland and mountain areas get considerably more. Years of average rainfall are rare. The usual pattern is a year-to-year variability, with a short string of dry years of rainfall, followed by one or two wet years with more than . Wet years are usually associated with warm water El Niño conditions in the Pacific, dry years with cooler water La Niña episodes. A series of rainy days can bring floods to the lowlands and mudslides to the hills, especially after wildfires have denuded the slopes. Both freezing temperatures and snowfall are extremely rare in the city basin and along the coast, with the last occurrence of a reading at the downtown station being January 29, 1979; freezing temperatures occur nearly every year in valley locations while the mountains within city limits typically receive snowfall every winter. The greatest snowfall recorded in downtown Los Angeles was on January 15, 1932. While the most recent snowfall occurred in February 2019, the first snowfall since 1962, with snow falling in areas adjacent to Los Angeles as recently as January 2021. At the official downtown station, the highest recorded temperature is on September 27, 2010, while the lowest is , on January 4, 1949. Within the City of Los Angeles, the highest temperature ever officially recorded is , on September 6, 2020, at the weather station at Pierce College in the San Fernando Valley neighborhood of Woodland Hills. During autumn and winter, Santa Ana winds sometimes bring much warmer and drier conditions to Los Angeles, and raise wildfire risk. Environmental issues A Gabrielino settlement in the area was called iyáangẚ (written Yang-na by the Spanish), which has been translated as "poison oak place". Yang-na has also been translated as "the valley of smoke". Owing to geography, heavy reliance on automobiles, and the Los Angeles/Long Beach port complex, Los Angeles suffers from air pollution in the form of smog. The Los Angeles Basin and the San Fernando Valley are susceptible to atmospheric inversion, which holds in the exhausts from road vehicles, airplanes, locomotives, shipping, manufacturing, and other sources. The percentage of small particle pollution (the kind that penetrates into the lungs) coming from vehicles in the city can get as high as 55 percent. The smog season lasts from approximately May to October. While other large cities rely on rain to clear smog, Los Angeles gets only of rain each year: pollution accumulates over many consecutive days. Issues of air quality in Los Angeles and other major cities led to the passage of early national environmental legislation, including the Clean Air Act. When the act was passed, California was unable to create a State Implementation Plan that would enable it to meet the new air quality standards, largely because of the level of pollution in Los Angeles generated by older vehicles. More recently, the state of California has led the nation in working to limit pollution by mandating low-emission vehicles. Smog is expected to continue to drop in the coming years because of aggressive steps to reduce it, which include electric and hybrid cars, improvements in mass transit, and other measures. The number of Stage 1 smog alerts in Los Angeles has declined from over 100 per year in the 1970s to almost zero in the new millennium. Despite improvement, the 2006 and 2007 annual reports of the American Lung Association ranked the city as the most polluted in the country with short-term particle pollution and year-round particle pollution. In 2008, the city was ranked the second most polluted and again had the highest year-round particulate pollution. The city met its goal of providing 20 percent of the city's power from renewable sources in 2010. The American Lung Association's 2013 survey ranks the metro area as having the nation's worst smog, and fourth in both short-term and year-round pollution amounts. Los Angeles is also home to the nation's largest urban oil field. There are more than 700 active oil wells within of homes, churches, schools and hospitals in the city, a situation about which the EPA has voiced serious concerns. Demographics The 2010 United States Census reported Los Angeles had a population of 3,792,621. The population density was 8,092.3 people per square mile (2,913.0/km2). The age distribution was 874,525 people (23.1%) under 18, 434,478 people (11.5%) from 18 to 24, 1,209,367 people (31.9%) from 25 to 44, 877,555 people (23.1%) from 45 to 64, and 396,696 people (10.5%) who were 65 or older. The median age was 34.1 years. For every 100 females, there were 99.2 males. For every 100 females age 18 and over, there were 97.6 males. There were 1,413,995 housing units—up from 1,298,350 during 2005–2009—at an average density of 2,812.8 households per square mile (1,086.0/km2), of which 503,863 (38.2%) were owner-occupied, and 814,305 (61.8%) were occupied by renters. The homeowner vacancy rate was 2.1%; the rental vacancy rate was 6.1%. 1,535,444 people (40.5% of the population) lived in owner-occupied housing units and 2,172,576 people (57.3%) lived in rental housing units. According to the 2010 United States Census, Los Angeles had a median household income of $49,497, with 22.0% of the population living below the federal poverty line. Race and ethnicity According to the 2010 Census, the racial makeup of Los Angeles included: 1,888,158 Whites (49.8%), 365,118 African Americans (9.6%), 28,215 Native Americans (0.7%), 426,959 Asians (11.3%), 5,577 Pacific Islanders (0.1%), 902,959 from other races (23.8%), and 175,635 (4.6%) from two or more races. Hispanics or Latinos of any race were 1,838,822 persons (48.5%). Los Angeles is home to people from more than 140 countries speaking 224 different identified languages. Ethnic enclaves like Chinatown, Historic Filipinotown, Koreatown, Little Armenia, Little Ethiopia, Tehrangeles, Little Tokyo, Little Bangladesh, and Thai Town provide examples of the polyglot character of Los Angeles. Non-Hispanic Whites were 28.7% of the population in 2010, compared to 86.3% in 1940. The majority of the Non-Hispanic White population is living in areas along the Pacific coast as well as in neighborhoods near and on the Santa Monica Mountains from the Pacific Palisades to Los Feliz. Mexican ancestry make up the largest ethnic group of Hispanics at 31.9% of the city's population, followed by those of Salvadoran (6.0%) and Guatemalan (3.6%) heritage. The Hispanic population has a long established Mexican-American and Central American community and is spread well-nigh throughout the entire city of Los Angeles and its metropolitan area. It is most heavily concentrated in regions around Downtown as East Los Angeles, Northeast Los Angeles and Westlake. Furthermore, a vast majority of residents in neighborhoods in eastern South Los Angeles towards Downey are of Hispanic origin. The largest Asian ethnic groups are Filipinos (3.2%) and Koreans (2.9%), which have their own established ethnic enclaves—Koreatown in the Wilshire Center and Historic Filipinotown. Chinese people, which make up 1.8% of Los Angeles's population, reside mostly outside of Los Angeles city limits and rather in the San Gabriel Valley of eastern Los Angeles County, but make a sizable presence in the city, notably in Chinatown. Chinatown and Thaitown are also home to many Thais and Cambodians, which make up 0.3% and 0.1% of Los Angeles's population, respectively. The Japanese comprise 0.9% of LA's population and have an established Little Tokyo in the city's downtown, and another significant community of Japanese Americans is in the Sawtelle district of West Los Angeles. Vietnamese make up 0.5% of Los Angeles's population. Indians make up 0.9% of the city's population. The city is also home to Armenians, Assyrians, and Iranians, many of whom live in enclaves like Little Armenia and Tehrangeles. African Americans have been the predominant ethnic group in South Los Angeles, which has emerged as the largest African American community in the western United States since the 1960s. The neighborhoods of South Los Angeles with highest concentration of African Americans include Crenshaw, Baldwin Hills, Leimert Park, Hyde Park, Gramercy Park, Manchester Square and Watts. Apart from South Los Angeles, neighborhoods in the Central region of Los Angeles, as Mid-City and Mid-Wilshire have a moderate concentration of African Americans as well. Religion According to a 2014 study by the Pew Research Center, Christianity is the most prevalently practiced religion in Los Angeles (65%). The Roman Catholic Archdiocese of Los Angeles is the largest archdiocese in the country. Cardinal Roger Mahony, as the archbishop, oversaw construction of the Cathedral of Our Lady of the Angels, which opened in September 2002 in Downtown Los Angeles. In 2011, the once common, but ultimately lapsed, custom of conducting a procession and Mass in honor of Nuestra Señora de los Ángeles, in commemoration of the founding of the City of Los Angeles in 1781, was revived by the Queen of Angels Foundation and its founder Mark Albert, with the support of the Archdiocese of Los Angeles as well as several civic leaders. The recently revived custom is a continuation of the original processions and Masses that commenced on the first anniversary of the founding of Los Angeles in 1782 and continued for nearly a century thereafter. With 621,000 Jews in the metropolitan area, the region has the second-largest population of Jews in the United States. Many of Los Angeles's Jews now live on the Westside and in the San Fernando Valley, though Boyle Heights once had a large Jewish population prior to World War II due to restrictive housing covenants. Major Orthodox Jewish neighborhoods include Hancock Park, Pico-Robertson, and Valley Village, while Jewish Israelis are well represented in the Encino and Tarzana neighborhoods, and Persian Jews in Beverly Hills. Many varieties of Judaism are represented in the greater Los Angeles area, including Reform, Conservative, Orthodox, and Reconstructionist. The Breed Street Shul in East Los Angeles, built in 1923, was the largest synagogue west of Chicago in its early decades; it is no longer in daily use as a synagogue and is being converted to a museum and community center. The Kabbalah Centre also has a presence in the city. The International Church of the Foursquare Gospel was founded in Los Angeles by Aimee Semple McPherson in 1923 and remains headquartered there to this day. For many years, the church convened at Angelus Temple, which, at its construction, was one of the largest churches in the country. Los Angeles has had a rich and influential Protestant tradition. The first Protestant service in Los Angeles was a Methodist meeting held in a private home in 1850 and the oldest Protestant church still operating, First Congregational Church, was founded in 1867. In the early 1900s the Bible Institute Of Los Angeles published the founding documents of the Christian Fundamentalist movement and the Azusa Street Revival launched Pentecostalism. The Metropolitan Community Church also had its origins in the Los Angeles area. Important churches in the city include First Presbyterian Church of Hollywood, Bel Air Presbyterian Church, First African Methodist Episcopal Church of Los Angeles, West Angeles Church of God in Christ, Second Baptist Church, Crenshaw Christian Center, McCarty Memorial Christian Church, and First Congregational Church. The Los Angeles California Temple, the second-largest temple operated by The Church of Jesus Christ of Latter-day Saints, is on Santa Monica Boulevard in the Westwood neighborhood of Los Angeles. Dedicated in 1956, it was the first temple of The Church of Jesus Christ of Latter-day Saints built in California and it was the largest in the world when completed. The Hollywood region of Los Angeles also has several significant headquarters, churches, and the Celebrity Center of Scientology. Because of Los Angeles's large multi-ethnic population, a wide variety of faiths are practiced, including Buddhism, Hinduism, Islam, Zoroastrianism, Sikhism, Baháʼí, various Eastern Orthodox Churches, Sufism, Shintoism, Taoism, Confucianism, Chinese folk religion and countless others. Immigrants from Asia for example, have formed a number of significant Buddhist congregations making the city home to the greatest variety of Buddhists in the world. The first Buddhist joss house was founded in the city in 1875. Atheism and other secular beliefs are also common, as the city is the largest in the Western U.S. Unchurched Belt. Homelessness As of January 2020, there are 41,290 homeless people in the City of Los Angeles, comprising roughly 62% of the homeless population of LA County. This is an increase of 14.2% over the previous year (with a 12.7% increase in the overall homeless population of LA County). The epicenter of homelessness in Los Angeles is the Skid Row neighborhood, which contains 8,000 homeless people, one of the largest stable populations of homeless people in the United States. The increased homeless population in Los Angeles has been attributed largely to lack of housing affordability. Almost 60 percent of the 82,955 people who became newly homeless in 2019 said their homelessness was because of economic hardship. In Los Angeles, black people are roughly four times more likely to experience homelessness. Crime In 1992, the city of Los Angeles recorded 1,092 murders. Los Angeles experienced a significant decline in crime in the 1990s and late 2000s and reached a 50-year low in 2009 with 314 homicides. This is a rate of 7.85 per 100,000 population—a major decrease from 1980 when a homicide rate of 34.2 per 100,000 was reported. This included 15 officer-involved shootings. One shooting led to the death of a SWAT team member, Randal Simmons, the first in LAPD's history. Los Angeles in the year of 2013 totaled 251 murders, a decrease of 16 percent from the previous year. Police speculate the drop resulted from a number of factors, including young people spending more time online. In 2021, murders rose to the highest level since 2008 and there were 348. In 2015, it was revealed that the LAPD had been under-reporting crime for eight years, making the crime rate in the city appear much lower than it really is. The Dragna crime family and the Cohen crime family dominated organized crime in the city during the Prohibition era and reached its peak during the 1940s and 1950s with the battle of Sunset Strip as part of the American Mafia, but has gradually declined since then with the rise of various black and Hispanic gangs in the late 1960s and early 1970s. According to the Los Angeles Police Department, the city is home to 45,000 gang members, organized into 450 gangs. Among them are the Crips and Bloods, which are both African American street gangs that originated in the South Los Angeles region. Latino street gangs such as the Sureños, a Mexican American street gang, and Mara Salvatrucha, which has mainly members of Salvadoran descent, all originated in Los Angeles. This has led to the city being referred to as the "Gang Capital of America". Economy The economy of Los Angeles is driven by international trade, entertainment (television, motion pictures, video games, music recording, and production), aerospace, technology, petroleum, fashion, apparel, and tourism. Other significant industries include finance, telecommunications, law, healthcare, and transportation. In the 2017 Global Financial Centres Index, Los Angeles was ranked as having the 19th most competitive financial center in the world, and sixth most competitive in the United States (after New York City, San Francisco, Chicago, Boston, and Washington, D.C.). One of the five major film studios, Paramount Pictures, is within the city limits, its location being part of the so-called "Thirty-Mile Zone" of entertainment headquarters in Southern California. Los Angeles is the largest manufacturing center in the United States. The contiguous ports of Los Angeles and Long Beach together comprise the busiest port in the United States by some measures and the fifth-busiest port in the world, vital to trade within the Pacific Rim. The Los Angeles metropolitan area has a gross metropolitan product of over $1.0 trillion (), making it the third-largest economic metropolitan area in the world, after Tokyo and New York. Los Angeles has been classified an "alpha world city" according to a 2012 study by a group at Loughborough University. The Department of Cannabis Regulation enforces cannabis legislation after the legalization of the sale and distribution of cannabis in 2016. , more than 300 existing cannabis businesses (both retailers and their suppliers) have been granted approval to operate in what is considered the nation's largest market. , Los Angeles is home to three Fortune 500 companies: AECOM, CBRE Group, and Reliance Steel & Aluminum Co. Arts and culture Los Angeles is often billed as the "Creative Capital of the World" because one in every six of its residents works in a creative industry and there are more artists, writers, filmmakers, actors, dancers and musicians living and working in Los Angeles than any other city at any other time in history. Movies and the performing arts The city's Hollywood neighborhood has become recognized as the center of the motion picture industry and the Los Angeles area is also associated as being the center of the television industry. The city is home to major film studios as well as major record labels. Los Angeles plays host to the annual Academy Awards, the Primetime Emmy Awards, the Grammy Awards as well as many other entertainment industry awards shows. Los Angeles is the site of the USC School of Cinematic Arts, the oldest film school in the United States. The performing arts play a major role in Los Angeles's cultural identity. According to the USC Stevens Institute for Innovation, "there are more than 1,100 annual theatrical productions and 21 openings every week." The Los Angeles Music Center is "one of the three largest performing arts centers in the nation", with more than 1.3 million visitors per year. The Walt Disney Concert Hall, centerpiece of the Music Center, is home to the prestigious Los Angeles Philharmonic. Notable organizations such as Center Theatre Group, the Los Angeles Master Chorale, and the Los Angeles Opera are also resident companies of the Music Center. Talent is locally cultivated at premier institutions such as the Colburn School and the USC Thornton School of Music. Museums and galleries There are 841 museums and art galleries in Los Angeles County, more museums per capita than any other city in the U.S. Some of the notable museums are the Los Angeles County Museum of Art (the largest art museum in the Western United States), the Getty Center (part of the J. Paul Getty Trust, the world's wealthiest art institution), the Petersen Automotive Museum, the Huntington Library, the Natural History Museum, the Battleship Iowa, and the Museum of Contemporary Art. A significant number of art galleries are on Gallery Row, and tens of thousands attend the monthly Downtown Art Walk there. Libraries The Los Angeles Public Library system operates 72 public libraries in the city. Enclaves of unincorporated areas are served by branches of the County of Los Angeles Public Library, many of which are within walking distance to residents. Landmarks Important landmarks in Los Angeles include the Hollywood Sign, Walt Disney Concert Hall, Capitol Records Building, the Cathedral of Our Lady of the Angels, Angels Flight, Grauman's Chinese Theatre, Dolby Theatre, Griffith Observatory, Getty Center, Getty Villa, Stahl House, the Los Angeles Memorial Coliseum, L.A. Live, the Los Angeles County Museum of Art, the Venice Canal Historic District and boardwalk, Theme Building, Bradbury Building, U.S. Bank Tower, Wilshire Grand Center, Hollywood Boulevard, Los Angeles City Hall, Hollywood Bowl, battleship , Watts Towers, Staples Center, Dodger Stadium, and Olvera Street. Sports The city of Los Angeles and its metropolitan area are the home of eleven top-level professional sports teams, several of which play in neighboring communities but use Los Angeles in their name. These teams include the Los Angeles Dodgers and Los Angeles Angels of Major League Baseball (MLB), the Los Angeles Rams and Los Angeles Chargers of the National Football League (NFL), the Los Angeles Lakers and Los Angeles Clippers of the National Basketball Association (NBA), the Los Angeles Kings and Anaheim Ducks of the National Hockey League (NHL), the Los Angeles Galaxy and Los Angeles FC of Major League Soccer (MLS), and the Los Angeles Sparks of the Women's National Basketball Association (WNBA). Other notable sports teams include the UCLA Bruins and the USC Trojans in the National Collegiate Athletic Association (NCAA), both of which are Division I teams in the Pac-12 Conference. Los Angeles is the second-largest city in the United States but hosted no NFL team between 1995 and 2015. At one time, the Los Angeles area hosted two NFL teams: the Rams and the Raiders. Both left the city in 1995, with the Rams moving to St. Louis, and the Raiders moving back to their original home of Oakland. After 21 seasons in St. Louis, on January 12, 2016, the NFL announced the Rams would be moving back to Los Angeles for the 2016 NFL season with its home games played at the Los Angeles Memorial Coliseum for four seasons. Prior to 1995, the Rams played their home games in the Coliseum from 1946 to 1979 which made them the first professional sports team to play in Los Angeles, and then moved to Anaheim Stadium from 1980 until 1994. The San Diego Chargers announced on January 12, 2017, that they would also relocate back to Los Angeles (the first since its inaugural season in 1960) and become the Los Angeles Chargers beginning in the 2017 NFL season and played at Dignity Health Sports Park in Carson, California for three seasons. The Rams and the Chargers would soon move to the newly built SoFi Stadium, located in nearby Inglewood during the 2020 season. Los Angeles boasts a number of sports venues, including Dodger Stadium, the Los Angeles Memorial Coliseum, Banc of California Stadium and the Crypto.com Arena. The Forum, SoFi Stadium, Dignity Health Sports Park, the Rose Bowl, Angel Stadium and Honda Center are also in adjacent cities and cities in Los Angeles's metropolitan area. Los Angeles has twice hosted the Summer Olympic Games: in 1932 and in 1984, and will host the games for a third time in 2028. Los Angeles will be the third city after London (1908, 1948 and 2012) and Paris (1900, 1924 and 2024) to host the Olympic Games three times. When the tenth Olympic Games were hosted in 1932, the former 10th Street was renamed Olympic Blvd. Los Angeles also hosted the Deaflympics in 1985 and Special Olympics World Summer Games in 2015. 7 NFL Super Bowls were also held in the city and its surrounding areas- 2 at the Memorial Coliseum (the first Super Bowl, I and VII) and 5 at the Rose Bowl in suburban Pasadena (XI, XIV, XVII, XXI, and XXVII), 10 miles north of downtown Los Angeles. Super Bowl LVI will be held at SoFi Stadium in Inglewood in 2022. The Rose Bowl also hosts an annual and highly prestigious NCAA college football game called the Rose Bowl, which happens every New Year's Day. Los Angeles also hosted 8 FIFA World Cup soccer games at the Rose Bowl in 1994, including the final, where Brazil won. The Rose Bowl also hosted 4 matches in the 1999 FIFA Women's World Cup, including the final, where the United States won against China on penalty kicks. This was the game where Brandi Chastain took her shirt off after she scored the tournament-winning penalty kick, creating an iconic image. Los Angeles is one of six North American cities to have won championships in all five of its major leagues (MLB, NFL, NHL, NBA and MLS), having completed the feat with the Kings' 2012 Stanley Cup title. Government Los Angeles is a charter city as opposed to a general law city. The current charter was adopted on June 8, 1999, and has been amended many times. The elected government consists of the Los Angeles City Council and the mayor of Los Angeles, which operate under a mayor–council government, as well as the city attorney (not to be confused with the district attorney, a county office) and controller. The mayor is Eric Garcetti. There are 15 city council districts. The city has many departments and appointed officers, including the Los Angeles Police Department (LAPD), the Los Angeles Board of Police Commissioners, the Los Angeles Fire Department (LAFD), the Housing Authority of the City of Los Angeles (HACLA), the Los Angeles Department of Transportation (LADOT), and the Los Angeles Public Library (LAPL). The charter of the City of Los Angeles ratified by voters in 1999 created a system of advisory neighborhood councils that would represent the diversity of stakeholders, defined as those who live, work or own property in the neighborhood. The neighborhood councils are relatively autonomous and spontaneous in that they identify their own boundaries, establish their own bylaws, and elect their own officers. There are about 90 neighborhood councils. Residents of Los Angeles elect supervisors for the 1st, 2nd, 3rd, and 4th supervisorial districts. Federal and state representation In the California State Assembly, Los Angeles is split between fourteen districts. In the California State Senate, the city is split between eight districts. In the United States House of Representatives, it is split among ten congressional districts. Education Colleges and universities There are three public universities within the city limits: California State University, Los Angeles (CSULA), California State University, Northridge (CSUN) and University of California, Los Angeles (UCLA). Private colleges in the city include: American Film Institute Conservatory Alliant International University American Academy of Dramatic Arts (Los Angeles Campus) American Jewish University Abraham Lincoln University The American Musical and Dramatic Academy – Los Angeles campus Antioch University's Los Angeles campus Charles R. Drew University of Medicine and Science Colburn School Columbia College Hollywood Emerson College (Los Angeles Campus) Emperor's College Fashion Institute of Design & Merchandising's Los Angeles campus (FIDM) Los Angeles Film School Loyola Marymount University (LMU is also the parent university of Loyola Law School in Los Angeles) Marymount College Mount St. Mary's College National University of California Occidental College ("Oxy") Otis College of Art and Design (Otis) Southern California Institute of Architecture (SCI-Arc) Southwestern Law School University of Southern California (USC) Woodbury University The community college system consists of nine campuses governed by the trustees of the Los Angeles Community College District: East Los Angeles College (ELAC) Los Angeles City College (LACC) Los Angeles Harbor College Los Angeles Mission College Los Angeles Pierce College Los Angeles Valley College (LAVC) Los Angeles Southwest College Los Angeles Trade-Technical College West Los Angeles College There are numerous additional colleges and universities outside the city limits in the Greater Los Angeles area, including the Claremont Colleges consortium, which includes the most selective liberal arts colleges in the U.S., and the California Institute of Technology (Caltech), one of the top STEM-focused research institutions in the world. Schools Los Angeles Unified School District serves almost all of the city of Los Angeles, as well as several surrounding communities, with a student population around 800,000. After Proposition 13 was approved in 1978, urban school districts had considerable trouble with funding. LAUSD has become known for its underfunded, overcrowded and poorly maintained campuses, although its 162 Magnet schools help compete with local private schools. Several small sections of Los Angeles are in the Inglewood Unified School District, and the Las Virgenes Unified School District. The Los Angeles County Office of Education operates the Los Angeles County High School for the Arts. Media The Los Angeles metro area is the second-largest broadcast designated market area in the U.S. (after New York) with 5,431,140 homes (4.956% of the U.S.), which is served by a wide variety of local AM and FM radio and television stations. Los Angeles and New York City are the only two media markets to have seven VHF allocations assigned to them. As part of the region's aforementioned creative industry, the Big Four major broadcast television networks, ABC, CBS, FOX, and NBC, all have production facilities and offices throughout various areas of Los Angeles. All four major broadcast television networks, plus major Spanish-language networks Telemundo and Univision, also own and operate stations that both serve the Los Angeles market and serve as each network's West Coast flagship station: ABC's KABC-TV (Channel 7), CBS's KCBS-TV (Channel 2), Fox's KTTV-TV (Channel 11), NBC's KNBC-TV (Channel 4), MyNetworkTV's KCOP-TV (Channel 13), Telemundo's KVEA-TV (Channel 52), and Univision's KMEX-TV (Channel 34). The region also has three PBS stations, as well as KCET (Channel 28), the nation's largest independent public television station. KTBN (Channel 40) is the flagship station of the religious Trinity Broadcasting Network, based out of Santa Ana. A variety of independent television stations, such as KCAL-TV (Channel 9) and KTLA-TV (Channel 5), also operate in the area. The major daily English-language newspaper in the area is the Los Angeles Times. La Opinión is the city's major daily Spanish-language paper. The Korea Times is the city's major daily Korean language paper while The World Journal is the city and county's major Chinese newspaper. The Los Angeles Sentinel is the city's major African-American weekly paper, boasting the largest African-American readership in the Western United States. Investor's Business Daily is distributed from its LA corporate offices, which are headquartered in Playa del Rey. There are also a number of smaller regional newspapers, alternative weeklies and magazines, including the Los Angeles Register, Los Angeles Community News, (which focuses on coverage of the greater Los Angeles area), Los Angeles Daily News (which focuses coverage on the San Fernando Valley), LA Weekly, L.A. Record (which focuses coverage on the music scene in the Greater Los Angeles Area), Los Angeles Magazine, the Los Angeles Business Journal, the Los Angeles Daily Journal (legal industry paper), The Hollywood Reporter, Variety (both entertainment industry papers), and Los Angeles Downtown News. In addition to the major papers, numerous local periodicals serve immigrant communities in their native languages, including Armenian, English, Korean, Persian, Russian, Chinese, Japanese, Hebrew, and Arabic. Many cities adjacent to Los Angeles also have their own daily newspapers whose coverage and availability overlaps with certain Los Angeles neighborhoods. Examples include The Daily Breeze (serving the South Bay), and The Long Beach Press-Telegram. Los Angeles arts, culture and nightlife news is also covered by a number of local and national online guides, including Time Out Los Angeles, Thrillist, Kristin's List, DailyCandy, Diversity News Magazine, LAist, and Flavorpill. Infrastructure Transportation Freeways The city and the rest of the Los Angeles metropolitan area are served by an extensive network of freeways and highways. The Texas Transportation Institute, which publishes an annual Urban Mobility Report, ranked Los Angeles road traffic as the most congested in the United States in 2005 as measured by annual delay per traveler. The average traveler in Los Angeles experienced 72 hours of traffic delay per year according to the study. Los Angeles was followed by San Francisco/Oakland, Washington, D.C., and Atlanta (each with 60 hours of delay). Despite the congestion in the city, the mean travel time for commuters in Los Angeles is shorter than other major cities, including New York City, Philadelphia and Chicago. Los Angeles's mean travel time for work commutes in 2006 was 29.2 minutes, similar to those of San Francisco and Washington, D.C. The major highways that connect LA to the rest of the nation include Interstate 5, which runs south through San Diego to Tijuana in Mexico and north through Sacramento, Portland, and Seattle to the Canada–US border; Interstate 10, the southernmost east–west, coast-to-coast Interstate Highway in the United States, going to Jacksonville, Florida; and U.S. Route 101, which heads to the California Central Coast, San Francisco, the Redwood Empire, and the Oregon and Washington coasts. Transit systems The LA County Metropolitan Transportation Authority (LA County Metro) and other agencies operate an extensive system of bus lines, as well as subway and light rail lines across Los Angeles County, with a combined monthly ridership (measured in individual boardings) of 38.8 million . The majority of this (30.5 million) is taken up by the city's bus system, the second busiest in the country. The subway and light rail combined average the remaining roughly 8.2 million boardings per month. LA County Metro recorded over 397 million boardings for the 2017 calendar year, including about 285 million bus riders and about 113 million riding on rail transit. For the first quarter of 2018, there were just under 95 million system-wide boardings, down from about 98 million in 2017, and about 105 million in 2016. In 2005, 10.2% of Los Angeles commuters rode some form of public transportation. According to the 2016 American Community Survey, 9.2% of working Los Angeles (city) residents made the journey to work via public transportation. The city's subway system is the ninth busiest in the United States and its light rail system is the country's busiest. The rail system includes the B and D subway lines, as well as the A, C, E, and L light rail lines. In 2016, the E Line was extended to the Pacific Ocean at Santa Monica. The Metro G and J lines are bus rapid transit lines with stops and frequency similar to those of light rail. , the total number of light rail stations is 93. The city is also central to the commuter rail system Metrolink, which links Los Angeles to all neighboring counties as well as many suburbs. Besides the rail service provided by Metrolink and the Los Angeles County Metropolitan Transportation Authority, Los Angeles is served by inter-city passenger trains from Amtrak. The main rail station in the city is Union Station just north of Downtown. In addition, the city directly contracts for local and commuter bus service through the Los Angeles Department of Transportation, or LADOT. Airports The main international and domestic airport serving Los Angeles is Los Angeles International Airport , commonly referred to by its airport code, LAX. Other major nearby commercial airports include: Ontario International Airport, owned by the city of Ontario, CA; serves the Inland Empire. Hollywood Burbank Airport, jointly owned by the cities of Burbank, Glendale, and Pasadena. Formerly known as Bob Hope Airport and Burbank Airport, the closest airport to Downtown Los Angeles serves the San Fernando, San Gabriel, and Antelope Valleys. Long Beach Airport, serves the Long Beach/Harbor area. John Wayne Airport of Orange County. One of the world's busiest general-aviation airports is also in Los Angeles: Van Nuys Airport . Seaports The Port of Los Angeles is in San Pedro Bay in the San Pedro neighborhood, approximately south of Downtown. Also called Los Angeles Harbor and WORLDPORT LA, the port complex occupies of land and water along of waterfront. It adjoins the separate Port of Long Beach. The sea ports of the Port of Los Angeles and Port of Long Beach together make up the Los Angeles/Long Beach Harbor. Together, both ports are the fifth busiest container port in the world, with a trade volume of over 14.2 million TEU's in 2008. Singly, the Port of Los Angeles is the busiest container port in the United States and the largest cruise ship center on the West Coast of the United States – The Port of Los Angeles's World Cruise Center served about 590,000 passengers in 2014. There are also smaller, non-industrial harbors along Los Angeles's coastline. The port includes four bridges: the Vincent Thomas Bridge, Henry Ford Bridge, Gerald Desmond Bridge, and Commodore Schuyler F. Heim Bridge. Passenger ferry service from San Pedro to the city of Avalon on Santa Catalina Island is provided by Catalina Express. Notable people As home to Hollywood and its entertainment industry, numerous singers, actors, celebrities and other entertainers live in various districts of Los Angeles. Sister cities Los Angeles has 25 sister cities, listed chronologically by year joined: Eilat, Israel (1959) Nagoya, Japan (1959) Salvador, Brazil (1962) Bordeaux, France (1964) Berlin, Germany (1967) Lusaka, Zambia (1968) Mexico City, Mexico (1969) Auckland, New Zealand (1971) Busan, South Korea (1971) Mumbai, India (1972) Tehran, Iran (1972) Taipei, Taiwan (1979) Guangzhou, China (1981) Athens, Greece (1984) Saint Petersburg, Russia (1984) Vancouver, Canada (1986) Giza, Egypt (1989) Jakarta, Indonesia (1990) Kaunas, Lithuania (1991) Makati, Philippines (1992) Split, Croatia (1993) San Salvador, El Salvador (2005) Beirut, Lebanon (2006) Ischia, Campania, Italy (2006) Yerevan, Armenia (2007) In addition, Los Angeles has the following "friendship cities": London, United Kingdom Łódź, Poland City of Melbourne, Australia Manchester, United Kingdom Tel Aviv, Israel See also Largest cities in Southern California Largest cities in the Americas List of hotels in Los Angeles List of largest houses in the Los Angeles Metropolitan Area List of museums in Los Angeles List of museums in Los Angeles County, California List of music venues in Los Angeles List of people from Los Angeles List of tallest buildings in Los Angeles Los Angeles in popular culture National Register of Historic Places listings in Los Angeles, California Notes References Further reading General Architecture and urban theory Race relations LGBT Environment Art and literature External links Cities in Los Angeles County, California County seats in California Incorporated cities and towns in California Populated coastal places in California Port cities in California Railway towns in California Populated places established in 1781 1781 establishments in New Spain 1850 establishments in California	[ 0.3877504765987396, -0.05213681980967522, 0.2905951738357544, -0.08413567394018173, -0.030863085761666298, 0.5184972286224365, -0.19650371372699738, 0.678505539894104, -0.38419249653816223, -0.4880000352859497, -0.3806583285331726, 0.06728322803974152, -0.21142740547657013, 0.3164460957050...
18111	https://en.wikipedia.org/wiki/Lepus%20%28constellation%29	Lepus (constellation)	Lepus (, ) is a constellation lying just south of the celestial equator. Its name is Latin for hare. It is located below—immediately south—of Orion (the hunter), and is sometimes represented as a hare being chased by Orion or by Orion's hunting dogs. Although the hare does not represent any particular figure in Greek mythology, Lepus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. History and mythology Lepus is most often represented as a hare being hunted by Orion, whose hunting dogs (Canis Major and Canis Minor) pursue it. The constellation is also associated with the Moon rabbit. Four stars of this constellation (α, β, γ, δ Lep) form a quadrilateral and are known as ‘Arsh al-Jawzā', "the Throne of Jawzā'" or Kursiyy al-Jawzā' al-Mu'akhkhar, "the Hindmost Chair of Jawzā'" and al-Nihāl, "the Camels Quenching Their Thirst" in Arabic. Features Stars There are a fair number of bright stars, both single and double, in Lepus. Alpha Leporis, the brightest star of Lepus, is a white supergiant of magnitude 2.6, 1300 light-years from Earth. Its traditional name, Arneb (أرنب ’arnab), means "hare" in Arabic. Beta Leporis, traditionally known as Nihal (Arabic for "quenching their thirst"), is a yellow giant of magnitude 2.8, 159 light-years from Earth. Gamma Leporis is a double star divisible in binoculars. The primary is a yellow star of magnitude 3.6, 29 light-years from Earth. The secondary is an orange star of magnitude 6.2. Delta Leporis is a yellow giant of magnitude 3.8, 112 light-years from Earth. Epsilon Leporis is an orange giant of magnitude 3.2, 227 light-years from Earth. Kappa Leporis is a double star divisible in medium aperture amateur telescopes, 560 light-years from Earth. The primary is a blue-white star of magnitude 4.4 and the secondary is a star of magnitude 7.4. There are several variable stars in Lepus. R Leporis is a Mira variable star. It is also called "Hind's Crimson Star" for its striking red color and because it was named for John Russell Hind. It varies in magnitude from a minimum of 9.8 to a maximum of 7.3, with a period of 420 days. R Leporis is at a distance of 1500 light-years. The color intensifies as the star brightens. It can be as dim as magnitude 12 and as bright as magnitude 5.5. T Leporis is also a Mira variable observed in detail by ESO's Very Large Telescope Interferometer. RX Leporis is a semi-regular red giant that has a period of 2 months. It has a minimum magnitude of 7.4 and a maximum magnitude of 5.0. Deep-sky objects There is one Messier object in Lepus, M79. It is a globular cluster of magnitude 8.0, 42,000 light-years from Earth. One of the few globular clusters visible in the Northern Celestial Hemisphere's winter, it is a Shapley class V cluster, which means that it has an intermediate concentration towards its center. It is often described as having a "starfish" shape. M79 was discovered in 1780 by Pierre Méchain. See also Lepus (Chinese astronomy) List of star names in Lepus References Inline citations Sources referenced Ridpath, Ian & Tirion, Wil (2007). Stars and Planets Guide, Collins, London. . Princeton University Press, Princeton. . External links Hundred metre virtual telescope captures unique detailed colour image — ESO's Organisational Release The Deep Photographic Guide to the Constellations: Lepus Star Tales – Lepus Warburg Institute Iconographic Database (medieval and early modern images of Lepus) Constellations Southern constellations Constellations listed by Ptolemy	[ 0.19714988768100739, 0.15061357617378235, 0.39838138222694397, -0.04209338501095772, -0.12779554724693298, 0.5175201892852783, -0.2537406086921692, 0.9016047716140747, -0.6008749604225159, -1.1293977499008179, -0.40290677547454834, -0.40694406628608704, -0.5189125537872314, 0.2222975194454...
18112	https://en.wikipedia.org/wiki/Lupus%20%28constellation%29	Lupus (constellation)	Lupus is a constellation of the mid-Southern Sky. Its name is Latin for wolf. Lupus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations but was long an asterism associated with the just westerly, larger constellation Centaurus. History and mythology In ancient times, the constellation was considered an asterism within Centaurus, and was considered to have been an arbitrary animal, killed, or about to be killed, on behalf of, or for, Centaurus. An alternative visualization, attested by Eratosthenes, saw this constellation as a wineskin held by Centaurus. It was not separated from Centaurus until Hipparchus of Bithynia named it ( meaning "beast") in the 2nd century BC. The Greek constellation is probably based on the Babylonian figure known as the Mad Dog (UR.IDIM). This was a strange hybrid creature that combined the head and torso of a man with the legs and tail of a lion (the cuneiform sign 'UR' simply refers to a large carnivore; lions, wolves and dogs are all included). It is often found in association with the sun god and another mythical being called the Bison-man, which is supposedly related to the Greek constellation of Centaurus. In Arab folk astronomy, Lupus, together with Centaurus were collectively called الشماريخ , meaning the dense branches of the date palm's fruit. Later, in Islamic Medieval astronomy, it was named السبع , which is a term used for any predatory wild beast (same as the Greek ), as a separate constellation, but drawn together with Centaurus. In some manuscripts of Al-Sufi's Book of Fixed Stars and celestial globes, it was drawn as a lion; in others, it is drawn as a wolf, both conforming to the Sab''' name. In Europe, no particular animal was associated with it until the Latin translation of Ptolemy's work identified it with the wolf. Characteristics Lupus is bordered by six different constellations, although one of them (Hydra) merely touches at the corner. The other five are Scorpius (the scorpion), Norma (the right angle), Circinus (the compass), Libra (the balance scale), and Centaurus (the centaur). Covering 333.7 square degrees and 0.809% of the night sky, it ranks 46th of the 88 modern constellations. The three-letter abbreviation for the constellation, as adopted by the International Astronomical Union in 1922, is Lup. The official constellation boundaries are defined by a twelve-sided polygon (illustrated in infobox). In the equatorial coordinate system, the right ascension coordinates of these borders lie between and, while the declination coordinates are between −29.83° and −55.58°. The whole constellation is visible to observers south of latitude 34°N. Features Stars Overall, there are 127 stars within the constellation's borders brighter than or equal to apparent magnitude 6.5. In his book Star Names and Their Meanings, R. H. Allen gave the names Yang Mun for Alpha Lupi, the brightest star in Lupus, and KeKwan for the blue giant Beta Lupi, both from Chinese. However, the first name is in error; both stars were part of a large Chinese constellation known in modern transliteration as Qíguān, the Imperial Guards. Most of the brightest stars in Lupus are massive members of the nearest OB association, Scorpius–Centaurus. Alpha Lupi is an ageing blue giant star of spectral type B1.5 III that is 460 ± 10 light-years distant from Earth. It is a Beta Cephei variable, pulsating in brightness by 0.03 of a magnitude every 7 hours and 6 minutes. Deep-sky objects Towards the north of the constellation are globular clusters NGC 5824 and NGC 5986, and close by the dark nebula B 228. To the south are two open clusters, NGC 5822 and NGC 5749, as well as globular cluster NGC 5927 on the eastern border with Norma. On the western border are two spiral galaxies and the Wolf–Rayet planetary nebula IC 4406, containing some of the hottest stars in existence. IC 4406, also called the Retina Nebula, is a cylindrical nebula at a distance of 5,000 light-years. It has dust lanes throughout its center. Another planetary nebula, NGC 5882, is towards the center of the constellation. The transiting exoplanet Lupus-TR-3b lies in this constellation. The historic supernova SN 1006 is described by various sources as appearing on April 30 to May 1, 1006, in the constellation of Lupus. ESO 274-1 is a spiral galaxy seen from edge-on that requires an amateur telescope with at least 12 inches of aperture to view. It can be found by using Lambda Lupi and Mu Lupi as markers, and can only be seen under very dark skies. It is 9 arcminutes by 0.7 arcminutes with a small, elliptical nucleus. See also SN 1006, a supernova widely observed in the year 1006, as well as the brightest stellar event in recorded history. Chinese star names Lupus in Chinese astronomy Notes References cited texts Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide'', Collins, London. . Princeton University Press, Princeton. . External links Star Tales – Lupus Warburg Institute Iconographic Database (medieval and early modern images of Lupus) Constellations Southern constellations Constellations listed by Ptolemy	[ 0.4539493918418884, -0.15114906430244446, 0.14034703373908997, -0.23397541046142578, -0.24822324514389038, 0.43136361241340637, 0.1725541651248932, 1.0751473903656006, -0.5607432126998901, -1.1300654411315918, -0.3961993455886841, -0.004796797875314951, -0.7305333614349365, 0.5299366712570...
18113	https://en.wikipedia.org/wiki/Lyra	Lyra	Lyra (; Latin for lyre, from Greek λύρα) is a small constellation. It is one of the 48 listed by the 2nd century astronomer Ptolemy, and is one of the modern 88 constellations recognized by the International Astronomical Union. Lyra was often represented on star maps as a vulture or an eagle carrying a lyre, and hence is sometimes referred to as Vultur Cadens or Aquila Cadens ("Falling Vulture" or "Falling Eagle"), respectively. Beginning at the north, Lyra is bordered by Draco, Hercules, Vulpecula, and Cygnus. Lyra is nearly overhead in temperate northern latitudes shortly after midnight at the start of summer. From the equator to about the 40th parallel south it is visible low in the northern sky during the same (thus winter) months. Vega, Lyra's brightest star, is one of the brightest stars in the night sky, and forms a corner of the famed Summer Triangle asterism. Beta Lyrae is the prototype of a class of binary stars known as Beta Lyrae variables. These binary stars are so close to each other that they become egg-shaped and material flows from one to the other. Epsilon Lyrae, known informally as the Double Double, is a complex multiple star system. Lyra also hosts the Ring Nebula, the second-discovered and best-known planetary nebula. History In Greek mythology, Lyra represents the lyre of Orpheus. Made by Hermes from a tortoise shell, given to Apollo as a bargain, it was said to be the first lyre ever produced. Orpheus's music was said to be so great that even inanimate objects such as rocks could be charmed. Joining Jason and the Argonauts, his music was able to quell the voices of the dangerous Sirens, who sang tempting songs to the Argonauts. At one point, Orpheus married Eurydice, a nymph. While fleeing from an attack by Aristaeus, she stepped on a snake that bit her, killing her. To reclaim her, Orpheus entered the Underworld, where the music from his lyre charmed Hades. Hades relented and let Orpheus bring Eurydice back, on the condition that he never once look back until outside. Unfortunately, near the very end, Orpheus faltered and looked back, causing Eurydice to be left in the Underworld forever. Orpheus spent the rest of his life strumming his lyre while wandering aimlessly through the land, rejecting all marriage offers from women. There are two competing myths relating to the death of Orpheus. According to Eratosthenes, Orpheus failed to make a necessary sacrifice to Dionysus due to his regard for Apollo as the supreme deity instead. Dionysus then sent his followers to rip Orpheus apart. Ovid tells a rather different story, saying that women, in retribution for Orpheus's rejection of marriage offers, ganged up and threw stones and spears. At first, his music charmed them as well, but eventually their numbers and clamor overwhelmed his music and he was hit by the spears. Both myths then state that his lyre was placed in the sky by Zeus, and Orpheus' bones buried by the muses. Vega and its surrounding stars are also treated as a constellation in other cultures. The area corresponding to Lyra was seen by the Arabs as a vulture or an eagle diving with folded wings. In Wales, Lyra is known as King Arthur's Harp (Talyn Arthur), and King David's harp. The Persian Hafiz called it the Lyre of Zurah. It has been called the Manger of the Infant Saviour, Praesepe Salvatoris. In Australian Aboriginal astronomy, Lyra is known by the Boorong people in Victoria as the Malleefowl constellation. Lyra was known as Urcuchillay by the Incas and was worshipped as an animal deity. Characteristics Lyra is bordered by Vulpecula to the south, Hercules to the east, Draco to the north, and Cygnus to the west. Covering 286.5 square degrees, it ranks 52nd of the 88 modern constellations in size. It appears prominently in the northern sky during the Northern Hemisphere's summer, and the whole constellation is visible for at least part of the year to observers north of latitude 42°S. Its main asterism consists of six stars, and 73 stars in total are brighter than magnitude 6.5. The constellation's boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a 17-sided polygon. In the equatorial coordinate system, the right ascension coordinates of these borders lie between and , while the declination coordinates are between and . The International Astronomical Union (IAU) adopted the three-letter abbreviation "Lyr" for the constellation in 1922. Features Stars German cartographer Johann Bayer used the Greek letters alpha through nu to label the most prominent stars in the constellation. English astronomer John Flamsteed observed and labelled two stars each as delta, epsilon, zeta and nu. He added pi and rho, not using xi and omicron as Bayer used these letters to denote Cygnus and Hercules on his map. The brightest star in the constellation is Vega (Alpha Lyrae), a main-sequence star of spectral type A0Va. Only 7.7 parsecs distant, Vega is a Delta Scuti variable, varying between magnitudes −0.02 and 0.07 over 0.2 days. On average, it is the second-brightest star of the northern hemisphere (after Arcturus) and the fifth-brightest star in all, surpassed only by Arcturus, Alpha Centauri, Canopus, and Sirius. Vega was the pole star in the year 12,000 BCE, and will again become the pole star around 14,000 CE. Vega is one of the most magnificent of all stars, and has been called "arguably the next most important star in the sky after the Sun". Vega was the first star other than the Sun to be photographed, as well as the first to have a clear spectrum recorded, showing absorption lines for the first time. The star was the first single main-sequence star other than the Sun to be known to emit X-rays, and is surrounded by a circumstellar debris disk, similar to the Kuiper Belt. Vega forms one corner of the famous Summer Triangle asterism; along with Altair and Deneb, these three stars form a prominent triangle during the northern hemisphere summer. Vega also forms one vertex of a much smaller triangle, along with Epsilon and Zeta Lyrae. Zeta forms a wide binary star visible in binoculars, consisting of an Am star and an F-type subgiant. The Am star has an additional close companion, bringing the total number of stars in the system to three. Epsilon is a more famous wide binary that can even be separated by the naked eye under good conditions. Both components are themselves close binaries which can be seen with telescopes to consist of A- and F-type stars, and a faint star was recently found to orbit component C as well, for a total of five stars. In contrast to Zeta and Epsilon Lyrae, Delta Lyrae is an optical double, with the two stars simply lying along the same line of sight east of Zeta. The brighter and closer of the two, Delta2 Lyrae, is a 4th-magnitude red bright giant that varies semiregularly by around 0.2 magnitudes with a dominant period of 79 days, while the fainter Delta1 Lyrae is a spectroscopic binary consisting of a B-type primary and an unknown secondary. Both systems, however, have very similar radial velocities, and are the two brightest members of a sparse open cluster known as the Delta Lyrae cluster. South of Delta is Gamma Lyrae, a blue giant and the second-brightest star in the constellation. Around 190 parsecs distant, it has been referred to as a "superficially normal" star. The final star forming the lyre's figure is Beta Lyrae, also a binary composed of a blue bright giant and an early B-type star. In this case, the stars are so close together that the larger giant is overflowing its Roche lobe and transferring material to the secondary, forming a semidetached system. The secondary, originally the less massive of the two, has accreted so much mass that it is now substantially more massive, albeit smaller, than the primary, and is surrounded by a thick accretion disk. The plane of the orbit is aligned with Earth and the system thus shows eclipses, dropping nearly a full magnitude from its 3rd-magnitude baseline every 13 days, although its period is increasing by around 19 seconds per year. It is the prototype of the Beta Lyrae variables, eclipsing semidetached binaries of early spectral types in which there are no exact onsets of eclipses, but rather continuous changes in brightness. Another easy-to-spot variable is the bright R Lyrae, north of the main asterism. Also known as 13 Lyrae, it is a 4th-magnitude red giant semiregular variable that varies by several tenths of a magnitude. Its periodicity is complex, with several different periods of varying lengths, most notably one of 46 days and one of 64 days. Even further north is FL Lyrae, a much fainter 9th-magnitude Algol variable that drops by half a magnitude every 2.18 days during the primary eclipse. Both components are main-sequence stars, the primary being late F-type and the secondary late G-type. The system was one of the first main-sequence eclipsing binaries containing G-type star to have its properties known as well as the better-studied early-type eclipsing binaries. At the very northernmost edge of the constellation is the even fainter V361 Lyrae, an eclipsing binary that does not easily fall into one of the traditional classes, with features of Beta Lyrae, W Ursae Majoris, and cataclysmic variables. It may be a representative of a very brief phase in which the system is transitioning into a contact binary. It can be found less than a degree away from the naked-eye star 16 Lyrae, a 5th-magnitude A-type subgiant located around 37 parsecs distant. The brightest star not included in the asterism and the westernmost cataloged by Bayer or Flamsteed is Kappa Lyrae, a typical red giant around 73 parsecs distant. Similar bright orange or red giants include the 4th-magnitude Theta Lyrae, Lambda Lyrae, and HD 173780. Lambda is located just south of Gamma, Theta is positioned in the east, and HD 173780, the brightest star in the constellation with no Bayer or Flamsteed designation, is more southernly. Just north of Theta and of almost exactly the same magnitude is Eta Lyrae, a blue subgiant with a near-solar metal abundance. Also nearby is the faint HP Lyrae, a post-asymptotic giant branch (AGB) star that shows variability. The reason for its variability is still a mystery: first cataloged as an eclipsing binary, it was theorized to be an RV Tauri variable in 2002, but if so, it would be by far the hottest such variable discovered. In the extreme east is RR Lyrae, the prototype of the large class of variables known as RR Lyrae variables, which are pulsating variables similar to Cepheids, but are evolved population II stars of spectral types A and F. Such stars are usually not found in a galaxy's thin disk, but rather in the galactic halo. Such stars serve as standard candles, and thus are a reliable way to calculate distances to the globular clusters in which they reside. RR Lyrae itself varies between magnitudes 7 and 8 while exhibiting the Blazhko effect. The easternmost star designated by Flamsteed, 19 Lyrae, is also a small-amplitude variable, an Alpha2 Canum Venaticorum variable with a period of just over one day. Another evolved star is the naked-eye variable XY Lyrae, a red bright giant just north of Vega that varies between 6th and 7th magnitudes over a period of 120 days. Also just visible to the naked eye is the peculiar classical Cepheid V473 Lyrae. It is unique in that it is the only known Cepheid in the Milky Way to undergo periodic phase and amplitude changes, analogous to the Blazhko effect in RR Lyrae stars. At 1.5 days, its period was the shortest known for a classical Cepheid at the time of its discovery. W and S Lyrae are two of the many Mira variables in Lyra. W varies between 7th and 12th magnitudes over approximately 200 days, while S, slightly fainter, is a silicate carbon star, likely of the J-type. Another evolved star is EP Lyrae, a faint RV Tauri variable and an "extreme example" of a post-AGB star. It and a likely companion are surrounded by a circumstellar disk of material. Rather close to Earth at a distance of only is Gliese 758. The sunlike primary star has a brown dwarf companion, the coldest to have been imaged around a sunlike star in thermal light when it was discovered in 2009. Only slightly farther away is V478 Lyrae, an eclipsing RS Canum Venaticorum variable whose primary star shows active starspot activity. One of the most peculiar systems in Lyra is MV Lyrae, a nova-like star consisting of a red dwarf and a white dwarf. Originally classified as a VY Sculptoris star due to spending most time at maximum brightness, since around 1979 the system has been dominantly at minimum brightness, with periodic outbursts. Its nature is still not fully understood. Another outbursting star is AY Lyrae, an SU Ursae Majoris-type dwarf nova that has undergone several superoutbursts. Of the same type is V344 Lyrae, notable for an extremely short period between superoutbursts coupled with one of the highest amplitudes for such a period. The true nova HR Lyrae flared in 1919 to a maximum magnitude of 6.5, over 9.5 magnitudes higher than in quiescence. Some of its characteristics are similar to those of recurring novae. Deep-sky objects M57, also known as the "Ring Nebula" and NGC 6720, at a distance of 2,000 light-years from Earth is one of the best known planetary nebulae and the second to be discovered; its integrated magnitude is 8.8. It was discovered in 1779 by Antoine Darquier, 15 years after Charles Messier discovered the Dumbbell Nebula. Astronomers have determined that it is between 6,000 and 8,000 years old; it is approximately one light-year in diameter. The outer part of the nebula appears red in photographs because of emission from ionized hydrogen. The middle region is colored green; doubly ionized oxygen emits greenish-blue light. The hottest region, closest to the central star, appears blue because of emission from helium. The central star itself is a white dwarf with a temperature of 120,000 kelvins. In telescopes, the nebula appears as a visible ring with a green tinge; it is slightly elliptical because its three-dimensional shape is a torus or cylinder seen from a slight angle. It can be found halfway between Gamma Lyrae and Beta Lyrae. Another planetary nebula in Lyra is Abell 46. The central star, V477 Lyrae, is an eclipsing post-common-envelope binary, consisting of a white dwarf primary and an oversized secondary component due to recent accretion. The nebula itself is of relatively low surface brightness compared to the central star, and is undersized for the primary's mass for reasons not yet fully understood. NGC 6791 is a cluster of stars in Lyra. It contains three age groups of stars: 4 billion year-old white dwarfs, 6 billion year-old white dwarfs and 8 billion year-old normal stars. NGC 6745 is an irregular spiral galaxy in Lyra that is at a distance of 208 million light-years. Several million years ago, it collided with a smaller galaxy, which created a region filled with young, hot, blue stars. Astronomers do not know if the collision was simply a glancing blow or a prelude to a full-on merger, which would end with the two galaxies incorporated into one larger, probably elliptical galaxy. A remarkable long-duration gamma-ray burst was GRB 050525A, which flared in 2005. The afterglow re-brightened at 33 minutes after the original burst, only the third found to exhibit such an effect in the timeframe, and unable to be completely explained by known phenomena. The light curve observed over the next 100 days was consistent with that of a supernova or even a hypernova, dubbed SN 2005nc. The host galaxy proved elusive to find at first, although it was subsequently identified. Exoplanets In orbit around the orange subgiant star HD 177830 is one of the earliest exoplanets to be detected. A jovian-mass planet, it orbits in an eccentric orbit with a period of 390 days. A second planet closer to the star was discovered in 2011. Visible to the naked eye are HD 173416, a yellow giant hosting a planet over twice the mass of Jupiter discovered in 2009; and HD 176051, a low-mass binary star containing another high-mass planet. Just short of naked-eye visibility is HD 178911, a triple system consisting of a close binary and a visually separable sunlike star. The sunlike star has a planet with over 6 Jupiter masses discovered in 2001, the second found in a triple system after that of 16 Cygni. One of the most-studied exoplanets in the night sky is TrES-1b, in orbit around the star GSC 02652-01324. Detected from a transit of its parent star, the planet has around 3/4 the mass of Jupiter, yet orbits its parent star in only three days. The transits have been reported to have anomalies multiple times. Originally thought to be possibly due to the presence of an Earth-like planet, it is now accepted that the irregularities are due to a large starspot. Also discovered by the transit method is WASP-3b, with 1.75 times the mass of Jupiter. At the time of its discovery, it was one of the hottest known exoplanets, in orbit around the F-type main-sequence star WASP-3. Similar to TrES-1b, irregularities in the transits had left open the possibility of a second planet, although this now appears unlikely as well. Lyra is one of three constellations (along with neighboring Cygnus and Draco) to be in the Kepler Mission's field of view, and as such it contains many more known exoplanets than most constellations. One of the first discovered by the mission is Kepler-7b, an extremely low-density exoplanet with less than half the mass of Jupiter, yet nearly 1.5 times the radius. Almost as sparse is Kepler-8b, only slightly more massive and of a similar radius. The Kepler-20 system contains five known planets; three of them are only slightly smaller than Neptune, while the other two are some of the first Earth-sized exoplanets to be discovered. Kepler-37 is another star with an exoplanet discovered by Kepler; the planet is the smallest known extrasolar planet known as of February 2013. In April 2013, it was announced that of the five planets orbiting Kepler-62, at least two—Kepler-62e and Kepler-62f—are within the boundaries of the habitable zone of that star, where scientists think liquid water could exist, and are both candidates for being a solid, rocky, earth-like planet. The exoplanets are 1.6 and 1.4 times the diameter of Earth respectively, with their star Kepler-62 at a distance of 1,200 light-years. See also Lyra (Chinese astronomy) Uttara Ashadha Notes References Citations External links Warburg Institute Iconographic Database (medieval and early modern images of Lyra) The clickable Lyra Constellations Northern constellations Constellations listed by Ptolemy	[ -0.002689084969460964, -0.11452768743038177, 0.11865576356649399, -0.6497332453727722, -0.041110385209321976, 0.7515743374824524, -0.5189607739448547, 0.5154599547386169, -0.32593032717704773, -0.6341241002082825, -0.37675854563713074, 0.2293614000082016, -0.4556991755962372, 0.30303314328...
18115	https://en.wikipedia.org/wiki/Legnica	Legnica	Legnica (Polish: ; , , , ) is a city in southwestern Poland, in the central part of Lower Silesia, on the Kaczawa River (left tributary of the Oder) and the Czarna Woda. Between 1 June 1975 and 31 December 1998 Legnica was the capital of the Legnica Voivodeship. It is currently the seat of the county and since 1992 the city has been the seat of a Diocese. As of 2020, Legnica had a population of 98,436 inhabitants. The city was first referenced in chronicles dating from the year 1004, although previous settlements could be traced back to the 7th century. The name "Legnica" was mentioned in 1149 under High Duke of Poland Bolesław IV the Curly. Legnica was most likely the seat of Bolesław and it became the residence of the high dukes that ruled the Duchy of Legnica from 1248 until 1675. Legnica is a city over which the Piast dynasty reigned the longest, for about 700 years, from the time of ruler Mieszko I of Poland after the creation of the Polish state in the 10th century, until 1675 and the death of the last Piast duke George William. Legnica is one of the historical burial sites of Polish monarchs and consorts. Legnica became renowned for the fierce battle that took place at Legnickie Pole near the city on 9 April 1241 during the first Mongol invasion of Poland. The Christian coalition under the command of the Polish Duke Henry II the Pious, supported by nobles, knights, and mercenaries, was decisively defeated by the Mongols. This, however, was a turning point in the war as the Mongols, having killed Henry II, halted their advance into Europe and retreated to Hungary through Moravia. During the High Middle Ages, Legnica was one of the most important cities of Central Europe. The city began to rapidly develop after the sudden discovery of gold in the Kaczawa River between Legnica and the town of Złotoryja. In 1675 it was incorporated into Habsburg ruled Kingdom of Bohemia. In 1742 the city was annexed by the Kingdom of Prussia after King Frederick the Great's victory over Austria in the War of the Austrian Succession. Subsequently, it was part of German Empire from 1871, and later Weimar Republic and Nazi Germany until the end of World War II, when majority of Lower Silesia east of the Neisse (Nysa), was transferred to Poland under border changes promulgated at the Potsdam Conference in 1945, when Poland was granted the Recovered Territories. Legnica is an economic, cultural and academic centre in Lower Silesia, together with Wrocław. The city is renowned for its varied architecture, spanning from early medieval to modern period, and its preserved Old Town with the Piast Castle, one of the largest in Poland. According to the Foreign direct investment ranking (FDI) from 2016, Legnica is one of the most progressive high-income cities in the Silesian region. Population Legnica has 102,708 inhabitants and is the third largest city in the voivodeship (after Wrocław and Wałbrzych) and 38th in Poland. It also constitutes the southernmost and the largest urban center of a copper deposit (Legnicko-Głogowski Okręg Miedziowy) with agglomeration of 448,617 inhabitants. Legnica is the largest city of the conurbation and is a member of the Association of Polish Cities. History Early history Archaeological research conducted in eastern Legnica in the late 1970s, showed the existence of a bronze foundry and the graves of three metallurgists. The find indicates a time interval about year 1000 BC. A settlement of the Lusatian culture people existed in the 8th century B.C. After invasions of Celts beyond upper Danube basin, the area of Legnica and north foothills of Sudetes was infiltrated by Celtic settlers and traders. Tacitus and Ptolemy recorded the ancient nation of Lugii (Lygii) in the area, and mentioned their town of Lugidunum, which has been attributed to both Legnica and Głogów. Slavic borough and early Poland Slavic Lechitic tribes moved into the area in the 8th century. The city was first officially mentioned in chronicles from 1004, although settlement dates to the 7th century. Dendrochronological research proves that during the reign of Mieszko I of Poland, a new fortified settlement was built here in a style typical of the early Piast dynasty. It is mentioned in 1149 when High Duke Bolesław IV the Curly funded a chapel at the St. Benedict monastery. Legnica was the most likely place of residence for Bolesław and it became the residence of the high dukes of Poland in 1163 and was the seat of a principality ruled from 1248 until 1675. Legnica became famous for the battle that took place at Legnickie Pole near the city on 9 April 1241 during the First Mongol invasion of Poland. The Christian army of the Polish duke Henry II the Pious of Silesia, supported by feudal nobility, which included in addition to Poles, Bavarian miners and military orders and Czech troops, was decisively defeated by the Mongols. The Mongols killed Henry and destroyed his forces, then turned south to rejoin the rest of the Mongol armies, which were massing at the Plain of Mohi in Hungary via Moravia against a coalition of King Bela IV and his armies, and Bela's Kipchak allies. After the war, nonetheless, the city was developing rapidly. In 1258 at the church of St. Peter, a parish school was established, probably the first of its kind in Poland. Around 1278 a Dominican monastery was founded by Bolesław II the Horned, who was buried there as the only monarch of Poland to be buried in Legnica. Already by 1300 there was a city council in Legnica. Duke Bolesław III the Generous granted new trade privileges in 1314 and 1318 and allowed the construction of a town hall, and in 1337 the first waterworks were built. In the years 1327–1380 a new Gothic church of Saint Peter (today's Cathedral) was erected in place of the old one, and is one of Legnica's landmarks since. Also by the 14th century the city walls were erected. In 1345 the first coins were produced in the local mint. In 1374, the potters' guild was founded, as one of the oldest in Silesia. Queen consort of Poland Hedwig of Sagan died in Legnica in 1390 and was buried in the local collegiate church, which has not survived to this day. Duchy of Legnica As the capital of the Duchy of Legnica at the beginning of the 14th century, Legnica was one of the most important cities of Central Europe, having a population of nearly 16,000 residents. The city began to expand quickly after the discovery of gold in the Kaczawa River between Legnica and Złotoryja (Goldberg). Unfortunately, such a growth rate can not be maintained long. Shortly after the city reached its maximum population increase, wooden buildings which had been erected during this period of rapid growth were devastated by a huge fire. The fire decreased the number of inhabitants in the city and halted any significant further development for many decades. Legnica, along with other Silesian duchies, became a vassal of the Kingdom of Bohemia during the 14th century and was included within the multi-ethnic Holy Roman Empire, however remained ruled by local dukes of the Polish Piast dynasty. In 1454, a local rebellion prevented Legnica from falling under direct rule of the Bohemian kings. In 1505, Duke Frederick II of Legnica met in Legnica with the duke of nearby Głogów, Sigismund I the Old, the future king of Poland. The Protestant Reformation was introduced in the duchy as early as 1522 and the population became Lutheran. In 1526, a Protestant university was established in Legnica, which, however, was closed in 1529. In 1528 the first printing house in Legnica was established. After the death of King Louis II of Hungary and Bohemia at Mohács in 1526, Legnica became a fief of the Habsburg Monarchy of Austria. The first map of Silesia was made by native son Martin Helwig. The city suffered during the Thirty Years' War. In 1633 a plague epidemic broke out, and in 1634 the Austrian army destroyed the suburbs. In 1668 Duke of Legnica Christian presented his candidacy to the Polish throne, however, in the 1669 Polish–Lithuanian royal election he wasn't chosen as King. In 1676, Legnica passed to direct Habsburg rule after the death of the last Silesian Piast duke and the last Piast duke overall, George William (son of Duke Christian), despite the earlier inheritance pact by Brandenburg and Silesia, by which it was to go to Brandenburg. The last Piast duke was buried in the St. John's church in Legnica in 1676. 18th and 19th centuries Silesian aristocracy was trained at the Liegnitz Ritter-Akademie, established in the early 18th century. One of two main routes connecting Warsaw and Dresden ran through the city in the 18th century and Kings Augustus II the Strong and Augustus III of Poland traveled that route many times. The postal milestone of King Augustus II comes from that period. In 1742 most of Silesia, including Liegnitz, became part of the Kingdom of Prussia after King Frederick the Great's defeat of Austria in the War of the Austrian Succession. In 1760 during the Seven Years' War, Liegnitz was the site of the Battle of Liegnitz when Frederick's army defeated an Austrian army led by Laudon. During the Napoleonic Wars and Polish national liberation fights, in 1807 Polish uhlans were stationed in the city, and in 1813, the Prussians, under Field Marshal Blücher, defeated the French forces of MacDonald in the Battle of Katzbach (Kaczawa) nearby. After the administrative reorganization of the Prussian state following the Congress of Vienna, Liegnitz and the surrounding territory (Landkreis Liegnitz) were incorporated into the Regierungsbezirk (administrative district) of Liegnitz, within the Province of Silesia on 1 May 1816. Along with the rest of Prussia, the town became part of the German Empire in 1871 during the unification of Germany. On 1 January 1874 Liegnitz became the third city in Lower Silesia (after Breslau and Görlitz) to be raised to an urban district, although the district administrator of the surrounding Landkreis of Liegnitz continued to have his seat in the city. Its military garrison was home to Königsgrenadier-Regiment Nr. 7 a military unit formed almost exclusively out of Polish soldiers. The 20th century The census of 1910 gave Liegnitz's population as 95.86% German, 0.15% German and Polish, 1.27% Polish, 2.26% Wendish, and 0.19% Czech. On 1 April 1937 parts of the Landkreis of Liegnitz communities of Alt Beckern (Piekary), Groß Beckern (Piekary Wielkie), Hummel, Liegnitzer Vorwerke, Pfaffendorf (Piątnica) und Prinkendorf (Przybków) were incorporated into the city limits. After the Treaty of Versailles following World War I, Liegnitz was part of the newly created Province of Lower Silesia from 1919 to 1938, then of the Province of Silesia from 1938 to 1941, and again of the Province of Lower Silesia from 1941 to 1945. After the Nazi Party came to power in Germany, as early as 1933, a boycott of local Jewish premises was ordered, during the Kristallnacht in 1938 the synagogue was burned down, and in 1939 the local Polish population was terrorized and persecuted. A Nazi court prison was operated in the city with a forced labour subcamp. During World War II, the Germans established two forced labour camps in the city, as well as two prisoner of war labor subcamps of the prisoner of war camp located in Żagań (then Sagan), and one labor subcamp of the Stalag VIII-A POW camp in Zgorzelec (then Görlitz). After the defeat of Nazi Germany during World War II, Liegnitz and all of Silesia east of the Neisse was preliminarily transferred to Poland following the Potsdam Conference in 1945. Majority of the German population was either expelled or fled from the city. The city was repopulated with Poles, some of whom were expelled from pre-war eastern Poland after its annexation by the Soviet Union. Also Greeks, refugees of the Greek Civil War, settled in Legnica in 1950. As the medieval Polish name Lignica was considered archaic, the town was renamed Legnica. The transfer to Poland decided at Potsdam in 1945 was officially recognized by East Germany in 1950, by West Germany under Chancellor Willy Brandt in the Treaty of Warsaw signed in 1970, and finally by the reunited Germany by the Two Plus Four Agreement in 1990. By 1990 only a handful of Polonized Germans, prewar citizens of Liegnitz, remained of the pre-1945 German population. In 2010 the city celebrated the 65th anniversary of the return of Legnica to Poland and its liberation from the Nazi Germany. The city was only partly damaged in World War II. In June 1945 Legnica was briefly the capital of the Lower Silesian (Wrocław) Voivodship, after the administration was moved there from Trzebnica and before it was finally moved to Wrocław. In 1947, the Municipal Library was opened, in 1948 a piano factory was founded, and in the years 1951-1959 Poland's first copper smelter was built in Legnica. After 1965 most parts of the preserved old town with its town houses were demolished, the historical layout was abolished, and the city was rebuilt in modern form.<ref>Dehio - Handbuch der Kunstdenkmäler in Polen: Schlesien, Herder-Institut Marburg and Krajowy Osrodek Badan i Dokumentacji Zabytkow Warszawa, Deutscher Kunstverlag 2005, , page 521</ref> From 1945 to 1990, during the Cold War, the headquarters of the Soviet forces in Poland, the so-called Northern Group of Forces, was located in the city. This fact had a strong influence on the life of the city. For much of the period, the city was divided into Polish and Soviet areas, with the latter closed to the public. These were first established in July 1945, when the Soviets forcibly ejected newly arrived Polish inhabitants from the parts of the city they wanted for their own use. The ejection was perceived by some as a particularly brutal action, and rumours circulated exaggerating its severity, though no evidence of anyone being killed in the course of it has come to light. In April 1946 city officials estimated that there were 16,700 Poles, 12,800 Germans, and 60,000 Soviets in Legnica. In October 1956, the largest anti-Soviet demonstrations in Lower Silesia took place in Legnica. The last Soviet units left the city in 1993. In 1992 the Roman Catholic Diocese of Legnica was established, Tadeusz Rybak became the first bishop of Legnica. New local newspapers and a radio station were founded in the 1990s. In 1997, Legnica was visited by Pope John Paul II. The city suffered in the 1997 Central European flood. Climate Legnica has an oceanic climate (Köppen climate classification: Cfb). Sights Legnica is a city with rich historical architecture, ranging from Romanesque and Gothic through the Renaissance and Baroque to Historicist styles. Among the landmarks of Legnica are: the Piast Castle, former seat of the local dukes of the Piast dynasty Cathedral of Saints Peter and Paul Market Square (Rynek) with: Baroque Old Town Hall (Stary Ratusz) Helena Modrzejewska Theatre Kamienice Śledziowe ("Herring Houses") Dom Pod Przepiórczym Koszem ("Under the Quail Basket House") former Dominican and later Benedictine monastery, founded by Bolesław II the Horned, who was buried there as the only monarch of Poland to be buried in Legnica; nowadays housing the I Liceum Ogólnokształcące im. Tadeusza Kościuszki (high school) Saint John the Baptist church with a mausoleum of the last Piast dukes New Town Hall (Nowy Ratusz), seat of city authorities Saint Mary church Copper Museum (Muzeum Miedzi) Medieval Chojnów and Głogów Gates, remnants of the medieval city walls Former Knight Academy, now housing municipal offices and a branch of the Copper Museum Public Library and archive Park Miejski ("City Park"), the oldest and largest park of Legnica There is also a monument of Pope John Paul II and a postal milestone of King Augustus II the Strong from 1725 in Legnica. Economy In the 1950s and 1960s the local copper and nickel industries became a major factor in the economic development of the area. Legnica houses industrial plants belonging to KGHM Polska Miedź, one of the largest producers of copper and silver in the world. The company owns a large copper mill on the western outskirts of town. There is a Special Economic Zone in Legnica, where Lenovo was going to open a factory in summer 2008. Education Legnica is a regional academic center with seven universities enrolling approximately 16,000 students. State-run colleges and universities Witelon University of Applied Sciences (Państwowa Wyższa Szkoła Zawodowa im. Witelona) Wrocław University of Technology Foreign Language Teacher Training College in Legnica Other Wyższa Szkoła Zarządzania / The Polish Open University Legnica University of Management Wyższe Seminarium Duchowne / Seminary Environment Legnica is noted for its parks and gardens, and has seven hundred hectares of green space, mostly along the banks of the Kaczawa; the Tarninow district is particularly attractive. Roads To the south of Legnica is the A4 motorway. Legnica has also a district, which is a part of national road no 3. The express road S3 building has been planned nearby. Public transport In the city there are 20 regular bus lines, 1 belt-line, 2 night lines and 3 suburban. The town has an airport (airport code EPLE) with a 1600-metre runway, the remains of a former Soviet air base, but it is () in a poor state and not used for commercial flights. Until the winter of 2003, the longest train service in Poland ran from Katowice to Legnica (via Kędzierzyn-Koźle, Nysa, and Jaworzyna Śląska). Sports Miedź Legnica – men's football team (Polish Cup winner 1992; played in the Ekstraklasa in season 2018–19) Films produced in Legnica In recent years Legnica has been frequently used as a film set for the following films as a result of its well preserved Old Town, proximity to Germany and low costs:Przebacz (dir. M. Stacharski) – 2005Anonyma – Eine Frau in Berlin (dir. M. Färberböck) – 2007Wilki (dir. F. Fromm) – 2007Little Moscow (dir. W. Krzystek) – 2008Mein Leben – Marcel Reich-Ranicki (dir. D. Zahavi) – 2008Die Wölfe (dir. F.Fromm) – 2009Jack Strong (dir. W. Pasikowski) – 2014 Politics Municipal politics Legnica tends to be a left-of-center town with a considerable influence of workers' unions. The Municipal Council of Legnica (Rada miejska miasta Legnica) is the legislative branch of the local government and is composed of 25 members elected in local elections every five years. The mayor or town president (Prezydent miasta) is the executive branch of the local government and is directly elected in the same municipal elections. Legnica – Jelenia Góra constituency Members of Parliament (Sejm) elected from Legnica-Jelenia Gora constituency: Ryszard Bonda, Samoobrona Bronisława Kowalska, SLD-UP Adam Lipiński, PiS Tadeusz Maćkała, PO Ryszard Maraszek, SLD-UP Olgierd Poniźnik, SLD-UP Władysław Rak, SLD-UP Tadeusz Samborski, PSL Jerzy Szmajdziński, SLD-UP Halina Szustak, LPR Michał Turkiewicz, SLD-UP Ryszard Zbrzyzny, SLD-UP Notable residents Henry II the Pious (1196/1207–1241), High Duke of Poland Witelo (1230–died 1280–1314), philosopher and scientist Bolesław II the Bald (1220–1278), High Duke of Poland Hans Aßmann Freiherr von Abschatz (1646–1699), lyricist and translator Georg Rudolf Böhmer (1723–1803), physician and botanist Johann Wilhelm Ritter (1776–1810), scientist, philosopher, discoverer of ultraviolet radiation Heinrich Wilhelm Dove (1803–1879) physicist Benjamin Bilse (1816–1902), conductor and composer Karl von Vogelsang (1818–1890), Catholic journalist, politician and social reformer Leopold Kronecker (1823–1891), mathematician Hugo Rühle (1824–1888), physician Gustav Winkler (1867–1954), textile manufacturer Wilhelm Schubart (1873–1960) classical philologist, historian and papyrologist Paul Löbe (1875–1967), social democratic politician Erich von Manstein (1887–1973) field marshal Gert Jeschonnek (1912–1999), an officer of the Navy, Vice Admiral, Chief of Navy Hans-Heinrich Jescheck (1915–2009), jurist Günter Reich (1921–1989), opera singer (baritone) Claus-Wilhelm Canaris (born 1937), jurist and legal philosopher Uta Zapf (born 1941), politician (SPD), member of the Bundestag from 1990 to 2013 Anna Dymna (born 1951), TV, film and theatre actress Jacek Oleksyn (born 1953), biologist Włodzimierz Juszczak (born 1957), bishop of the Eparchy of Wroclaw–Gdansk of the Ukrainian Greek Catholic Church Marzena Kipiel-Sztuka (born 1965), actress Beata Tadla (born 1975), journalist and TV presenter Tomasz Kot (born 1977), actor Marek Pająk (born 1977), musician Popek (born 1978), rapper and MMA fighter Mariusz Lewandowski (born 1979), footballer Aleksandra Klejnowska (born 1982), weightlifter Marcin Robak (born 1982), football player Jagoda Szmytka (born 1982), composer Jakub Popiwczak (born 1996), volleyball player Joanna Jarmołowicz (born 1994), actress Twin towns – sister cities Legnica is twinned with: Blansko, Czech Republic Drohobych, Ukraine Meissen, Germany Roanne, France Wuppertal, Germany In fiction Legnica and its then ruler Count Conrad figure prominently in the alternate history series The Crosstime Engineer, set in the period of 1230 to 1270, by Leo Frankowski. References External links Map of Silesia with town of Li(e)gnitz in 1600 Li(e)gnitz on HRE Germany map in 1600 Jewish Community in Legnica on Virtual Shtetl0 Legnica - Liegnitz, Lignica na portalu polska-org.pl Municipal website Lca.pl City hall Legnica Cities and towns in Lower Silesian Voivodeship Cities in Silesia City counties of Poland	[ 0.1912614107131958, -0.5315163135528564, 0.5260086059570312, -0.5233649611473083, -0.38405606150627136, 0.9873931407928467, 0.2745915651321411, 0.4788624048233032, -0.45420485734939575, -0.5374804735183716, 0.10710035264492035, 0.013059751130640507, -0.035923831164836884, 0.371879100799560...
18119	https://en.wikipedia.org/wiki/Liverpool%20F.C.	Liverpool F.C.	Liverpool Football Club is a professional football club based in Liverpool, England, that competes in the Premier League, the top tier of English football. Domestically, the club has won nineteen League titles, seven FA Cups, a record nine League Cups and fifteen FA Community Shields. In international competitions, the club has won six European Cups, more than any other English club, three UEFA Cups, four UEFA Super Cups, and one FIFA Club World Cup. In terms of trophies won, it is the joint-most successful club in English football. Founded in 1892, the club joined the Football League the following year and has played at Anfield since its formation. Liverpool established itself as a major force in English and European football in the 1970s and 1980s, when Bill Shankly, Bob Paisley, Joe Fagan and Kenny Dalglish led the club to a combined eleven League titles and four European Cups. Liverpool won two further European Cups in 2005 and 2019 under the management of Rafael Benítez and Jürgen Klopp, respectively; the latter led Liverpool to a nineteenth League title in 2020, the club's first during the Premier League era. Liverpool is one of the most widely supported clubs in the world, as well as one of the most valuable. Liverpool has long-standing rivalries with Manchester United and Everton. In 1964 the team changed from red shirts and white shorts to an all-red home strip which has been used ever since. The club's anthem is "You'll Never Walk Alone". The club's supporters have been involved in two major tragedies. The Heysel Stadium disaster, where escaping fans were pressed against a collapsing wall at the 1985 European Cup Final in Brussels, resulted in 39 deaths. Most of these were Italians and Juventus fans, and English clubs were given a five-year ban from European competition as a result. The Hillsborough disaster in 1989, where 97 Liverpool supporters died in a crush against perimeter fencing, led to the elimination of fenced standing terraces in favour of all-seater stadiums in the top two tiers of English football. History Liverpool F.C. was founded following a dispute between the Everton committee and John Houlding, club president and owner of the land at Anfield. After eight years at the stadium, Everton relocated to Goodison Park in 1892 and Houlding founded Liverpool F.C. to play at Anfield. Originally named "Everton F.C. and Athletic Grounds Ltd" (Everton Athletic for short), the club became Liverpool F.C. in March 1892 and gained official recognition three months later, after The Football Association refused to recognise the club as Everton. Liverpool played their first match on 1 September 1892, a pre-season friendly match against Rotherham Town, which they won 7–1. The team Liverpool fielded against Rotherham was composed entirely of Scottish players – the players who came from Scotland to play in England in those days were known as the Scotch Professors. Manager John McKenna had recruited the players after a scouting trip to Scotland – so they became known as the "team of Macs". The team won the Lancashire League in its debut season and joined the Football League Second Division at the start of the 1893–94 season. After the club was promoted to the First Division in 1896, Tom Watson was appointed manager. He led Liverpool to its first league title in 1901, before winning it again in 1906. Liverpool reached its first FA Cup Final in 1914, losing 1–0 to Burnley. It won consecutive League championships in 1922 and 1923, but did not win another trophy until the 1946–47 season, when the club won the First Division for a fifth time under the control of ex-West Ham United centre half George Kay. Liverpool suffered its second Cup Final defeat in 1950, playing against Arsenal. The club was relegated to the Second Division in the 1953–54 season. Soon after Liverpool lost 2–1 to non-league Worcester City in the 1958–59 FA Cup, Bill Shankly was appointed manager. Upon his arrival he released 24 players and converted a boot storage room at Anfield into a room where the coaches could discuss strategy; here, Shankly and other "Boot Room" members Joe Fagan, Reuben Bennett, and Bob Paisley began reshaping the team. The club was promoted back into the First Division in 1962 and won it in 1964, for the first time in 17 years. In 1965, the club won its first FA Cup. In 1966, the club won the First Division but lost to Borussia Dortmund in the European Cup Winners' Cup final. Liverpool won both the League and the UEFA Cup during the 1972–73 season, and the FA Cup again a year later. Shankly retired soon afterwards and was replaced by his assistant, Bob Paisley. In 1976, Paisley's second season as manager, the club won another League and UEFA Cup double. The following season, the club retained the League title and won the European Cup for the first time, but it lost in the 1977 FA Cup Final. Liverpool retained the European Cup in 1978 and regained the First Division title in 1979. During Paisley's nine seasons as manager Liverpool won 20 trophies, including three European Cups, a UEFA Cup, six League titles and three consecutive League Cups; the only domestic trophy he did not win was the FA Cup. Paisley retired in 1983 and was replaced by his assistant, Joe Fagan. Liverpool won the League, League Cup and European Cup in Fagan's first season, becoming the first English side to win three trophies in a season. Liverpool reached the European Cup final again in 1985, against Juventus at the Heysel Stadium. Before kick-off, Liverpool fans breached a fence that separated the two groups of supporters and charged the Juventus fans. The resulting weight of people caused a retaining wall to collapse, killing 39 fans, mostly Italians. The incident became known as the Heysel Stadium disaster. The match was played in spite of protests by both managers, and Liverpool lost 1–0 to Juventus. As a result of the tragedy, English clubs were banned from participating in European competition for five years; Liverpool received a ten-year ban, which was later reduced to six years. Fourteen Liverpool fans received convictions for involuntary manslaughter. Fagan had announced his retirement just before the disaster and Kenny Dalglish was appointed as player-manager. During his tenure, the club won another three league titles and two FA Cups, including a League and Cup "Double" in the 1985–86 season. Liverpool's success was overshadowed by the Hillsborough disaster: in an FA Cup semi-final against Nottingham Forest on 15 April 1989, hundreds of Liverpool fans were crushed against perimeter fencing. Ninety-four fans died that day; the 95th victim died in hospital from his injuries four days later, the 96th died nearly four years later, without regaining consciousness, and the 97th, Andrew Devine, died of injuries sustained in the disaster in 2021. After the Hillsborough disaster there was a government review of stadium safety. The resulting Taylor Report paved the way for legislation that required top-division teams to have all-seater stadiums. The report ruled that the main reason for the disaster was overcrowding due to a failure of police control. Liverpool was involved in the closest finish to a league season during the 1988–89 season. Liverpool finished equal with Arsenal on both points and goal difference, but lost the title on total goals scored when Arsenal scored the final goal in the last minute of the season. Dalglish cited the Hillsborough disaster and its repercussions as the reason for his resignation in 1991; he was replaced by former player Graeme Souness. Under his leadership Liverpool won the 1992 FA Cup Final, but their league performances slumped, with two consecutive sixth-place finishes, eventually resulting in his dismissal in January 1994. Souness was replaced by Roy Evans, and Liverpool went on to win the 1995 Football League Cup Final. While they made some title challenges under Evans, third-place finishes in 1996 and 1998 were the best they could manage, and so Gérard Houllier was appointed co-manager in the 1998–99 season, and became the sole manager in November 1998 after Evans resigned. In 2001, Houllier's second full season in charge, Liverpool won a "treble": the FA Cup, League Cup and UEFA Cup. Houllier underwent major heart surgery during the 2001–02 season and Liverpool finished second in the League, behind Arsenal. They won a further League Cup in 2003, but failed to mount a title challenge in the two seasons that followed. Houllier was replaced by Rafael Benítez at the end of the 2003–04 season. Despite finishing fifth in Benítez's first season, Liverpool won the 2004–05 UEFA Champions League, beating A.C. Milan 3–2 in a penalty shootout after the match ended with a score of 3–3. The following season, Liverpool finished third in the Premier League and won the 2006 FA Cup Final, beating West Ham United in a penalty shootout after the match finished 3–3. American businessmen George Gillett and Tom Hicks became the owners of the club during the 2006–07 season, in a deal which valued the club and its outstanding debts at £218.9 million. The club reached the 2007 UEFA Champions League Final against Milan, as it had in 2005, but lost 2–1. During the 2008–09 season Liverpool achieved 86 points, its highest Premier League points total, and finished as runners up to Manchester United. In the 2009–10 season, Liverpool finished seventh in the Premier League and failed to qualify for the Champions League. Benítez subsequently left by mutual consent and was replaced by Fulham manager Roy Hodgson. At the start of the 2010–11 season Liverpool was on the verge of bankruptcy and the club's creditors asked the High Court to allow the sale of the club, overruling the wishes of Hicks and Gillett. John W. Henry, owner of the Boston Red Sox and of Fenway Sports Group, bid successfully for the club and took ownership in October 2010. Poor results during the start of that season led to Hodgson leaving the club by mutual consent and former player and manager Kenny Dalglish taking over. In the 2011–12 season, Liverpool secured a record 8th League Cup success and reached the FA Cup final, but finished in eighth position, the worst league finish in 18 years; this led to the sacking of Dalglish. He was replaced by Brendan Rodgers, whose Liverpool team in the 2013–14 season mounted an unexpected title charge to finish second behind champions Manchester City and subsequently return to the Champions League, scoring 101 goals in the process, the most since the 106 scored in the 1895–96 season. Following a disappointing 2014–15 season, where Liverpool finished sixth in the league, and a poor start to the following campaign, Rodgers was sacked in October 2015. Rodgers was replaced by Jürgen Klopp. Liverpool reached the finals of the Football League Cup and UEFA Europa League in Klopp's first season, finishing as runner-up in both competitions. The club finished second in the 2018–19 season with 97 points, losing only one game: a points record for a non-title winning side. Klopp took Liverpool to successive Champions League finals in 2018 and 2019, with the club defeating Tottenham Hotspur 2–0 to win the 2019 UEFA Champions League Final. Liverpool beat Flamengo of Brazil in the final 1–0 to win the FIFA Club World Cup for the first time. Liverpool then went on to win the 2019–20 Premier League, winning their first top-flight league title in thirty years. The club set multiple records in the season, including winning the league with seven games remaining making it the earliest any team has ever won the title, amassing a club record 99 points, and achieving a joint-record 32 wins in a top-flight season. Colours and badge For much of Liverpool's history its home colours have been all red, but when the club was founded its kit was more like the contemporary Everton kit. The blue and white quartered shirts were used until 1894, when the club adopted the city's colour of red. The city's symbol of the liver bird was adopted as the club's badge (or crest, as it is sometimes known) in 1901, although it was not incorporated into the kit until 1955. Liverpool continued to wear red shirts and white shorts until 1964 when manager Bill Shankly decided to change to an all-red strip. Liverpool played in all red for the first time against Anderlecht, as Ian St John recalled in his autobiography: The Liverpool away strip has more often than not been all yellow or white shirts and black shorts, but there have been several exceptions. An all grey kit was introduced in 1987, which was used until the 1991–92 centenary season when it was replaced by a combination of green shirts and white shorts. After various colour combinations in the 1990s, including gold and navy, bright yellow, black and grey, and ecru, the club alternated between yellow and white away kits until the 2008–09 season, when it re-introduced the grey kit. A third kit is designed for European away matches, though it is also worn in domestic away matches on occasions when the current away kit clashes with a team's home kit. Between 2012 and 2015, the kits were designed by Warrior Sports, who became the club's kit providers at the start of the 2012–13 season. In February 2015, Warrior's parent company New Balance announced it would be entering the global football market, with teams sponsored by Warrior now being outfitted by New Balance. The only other branded shirts worn by the club were made by Umbro until 1985, when they were replaced by Adidas, who produced the kits until 1996 when Reebok took over. They produced the kits for 10 years before Adidas made the kits from 2006 to 2012. Nike became the club's official kit supplier at the start of the 2020–21 season. Liverpool was the first English professional club to have a sponsor's logo on its shirts, after agreeing a deal with Hitachi in 1979. Since then the club has been sponsored by Crown Paints, Candy, Carlsberg and Standard Chartered. The contract with Carlsberg, which was signed in 1992, was the longest-lasting agreement in English top-flight football. The association with Carlsberg ended at the start of the 2010–11 season, when Standard Chartered Bank became the club's sponsor. The Liverpool badge is based on the city's liver bird symbol, which in the past had been placed inside a shield. In 1977, a red liver bird standing on a football (blazoned as "Statant upon a football a Liver Bird wings elevated and addorsed holding in the beak a piece of seaweed gules") was granted as a heraldic badge by the College of Arms to the English Football League intended for use by Liverpool. However, Liverpool never made use of this badge. In 1992, to commemorate the centennial of the club, a new badge was commissioned, including a representation of the Shankly Gates. The next year twin flames were added at either side, symbolic of the Hillsborough memorial outside Anfield, where an eternal flame burns in memory of those who died in the Hillsborough disaster. In 2012, Warrior Sports' first Liverpool kit removed the shield and gates, returning the badge to what had adorned Liverpool shirts in the 1970s; the flames were moved to the back collar of the shirt, surrounding the number 96 for the number who died at Hillsborough. Kit suppliers and shirt sponsors Stadium Anfield was built in 1884 on land adjacent to Stanley Park. Situated 2 miles (3 km) from Liverpool city centre, it was originally used by Everton before the club moved to Goodison Park after a dispute over rent with Anfield owner John Houlding. Left with an empty ground, Houlding founded Liverpool in 1892 and the club has played at Anfield ever since. The capacity of the stadium at the time was 20,000, although only 100 spectators attended Liverpool's first match at Anfield. The Kop was built in 1906 due to the high turnout for matches and was called the Oakfield Road Embankment initially. Its first game was on 1 September 1906 when the home side beat Stoke City 1–0. In 1906 the banked stand at one end of the ground was formally renamed the Spion Kop after a hill in KwaZulu-Natal. The hill was the site of the Battle of Spion Kop in the Second Boer War, where over 300 men of the Lancashire Regiment died, many of them from Liverpool. At its peak, the stand could hold 28,000 spectators and was one of the largest single-tier stands in the world. Many stadiums in England had stands named after Spion Kop, but Anfield's was the largest of them at the time; it could hold more supporters than some entire football grounds. Anfield could accommodate more than 60,000 supporters at its peak and had a capacity of 55,000 until the 1990s, when, following recommendations from the Taylor Report, all clubs in the Premier League were obliged to convert to all-seater stadiums in time for the 1993–94 season, reducing its capacity to 45,276. The findings of the report precipitated the redevelopment of the Kemlyn Road Stand, which was rebuilt in 1992, coinciding with the centenary of the club, and was known as the Centenary Stand until 2017 when it was renamed the Kenny Dalglish Stand. An extra tier was added to the Anfield Road end in 1998, which further increased the capacity of the ground but gave rise to problems when it was opened. A series of support poles and stanchions were inserted to give extra stability to the top tier of the stand after movement of the tier was reported at the start of the 1999–2000 season. Because of restrictions on expanding the capacity at Anfield, Liverpool announced plans to move to the proposed Stanley Park Stadium in May 2002. Planning permission was granted in July 2004, and in September 2006, Liverpool City Council agreed to grant Liverpool a 999-year lease on the proposed site. Following the takeover of the club by George Gillett and Tom Hicks in February 2007, the proposed stadium was redesigned. The new design was approved by the Council in November 2007. The stadium was scheduled to open in August 2011 and would hold 60,000 spectators, with HKS, Inc. contracted to build the stadium. Construction was halted in August 2008, as Gillett and Hicks had difficulty in financing the £300 million needed for the development. In October 2012, BBC Sport reported that Fenway Sports Group, the new owners of Liverpool FC, had decided to redevelop their current home at Anfield stadium, rather than building a new stadium in Stanley Park. As part of the redevelopment the capacity of Anfield was to increase from 45,276 to approximately 60,000 and would cost approximately £150m. When construction was completed on the new Main stand the capacity of Anfield was increased to 54,074. This £100 million expansion added a third tier to the stand. This was all part of a £260 million project to improve the Anfield area. Jürgen Klopp the manager at the time described the stand as "impressive." In June 2021, it was reported that Liverpool Council had given planning permission for the club to renovate and expand the Anfield Road stand, boosting the capacity by around 7,000 and taking the overall capacity at Anfield to 61,000. The expansion, which is estimated to cost £60m, was described as "a huge milestone" by managing director Andy Hughes, and would also see rail seating being trialled in the Kop for the 2021-22 Premier League season. Support Liverpool is one of the best supported clubs in the world. The club states that its worldwide fan base includes more than 200 officially recognised Supporters Clubs in at least 50 countries. Notable groups include Spirit of Shankly. The club takes advantage of this support through its worldwide summer tours, which has included playing in front of 101,000 in Michigan, U.S., and 95,000 in Melbourne, Australia. Liverpool fans often refer to themselves as Kopites, a reference to the fans who once stood, and now sit, on the Kop at Anfield. In 2008 a group of fans decided to form a splinter club, A.F.C. Liverpool, to play matches for fans who had been priced out of watching Premier League football. The song "You'll Never Walk Alone", originally from the Rodgers and Hammerstein musical Carousel and later recorded by Liverpool musicians Gerry and the Pacemakers, is the club's anthem and has been sung by the Anfield crowd since the early 1960s. It has since gained popularity among fans of other clubs around the world. The song's title adorns the top of the Shankly Gates, which were unveiled on 2 August 1982 in memory of former manager Bill Shankly. The "You'll Never Walk Alone" portion of the Shankly Gates is also reproduced on the club's badge. The club's supporters have been involved in two stadium disasters. The first was the 1985 Heysel Stadium disaster, in which 39 Juventus supporters were killed. They were confined to a corner by Liverpool fans who had charged in their direction; the weight of the cornered fans caused a wall to collapse. UEFA laid the blame for the incident solely on the Liverpool supporters, and banned all English clubs from European competition for five years. Liverpool was banned for an additional year, preventing it from participating in the 1990–91 European Cup, even though it won the League in 1990. Twenty-seven fans were arrested on suspicion of manslaughter and were extradited to Belgium in 1987 to face trial. In 1989, after a five-month trial in Belgium, 14 Liverpool fans were given three-year sentences for involuntary manslaughter; half of the terms were suspended. The second disaster took place during an FA Cup semi-final between Liverpool and Nottingham Forest at Hillsborough Stadium, Sheffield, on 15 April 1989. Ninety-six Liverpool fans died as a consequence of overcrowding at the Leppings Lane end, in what became known as the Hillsborough disaster. In the following days, The Suns coverage of the event spread falsehoods, particularly an article entitled "The Truth" that claimed that Liverpool fans had robbed the dead and had urinated on and attacked the police. Subsequent investigations proved the allegations false, leading to a boycott of the newspaper by Liverpool fans across the city and elsewhere; many still refuse to buy The Sun 30 years later. Many support organisations were set up in the wake of the disaster, such as the Hillsborough Justice Campaign, which represents bereaved families, survivors and supporters in their efforts to secure justice. Rivalries Liverpool's longest-established rivalry is with fellow Liverpool team Everton, against whom they contest the Merseyside derby. The rivalry stems from Liverpool's formation and the dispute with Everton officials and the then owners of Anfield. The Merseyside derby is one of the few local derbies which do not enforce fan segregation, and hence has been known as the "friendly derby". Since the mid-1980s, the rivalry has intensified both on and off the field and, since the inception of the Premier League in 1992, the Merseyside derby has had more players sent off than any other Premier League game. It has been referred to as "the most ill-disciplined and explosive fixture in the Premier League". In terms of support within the city, the number of Liverpool fans outweighs Everton supporters by a ratio of 2:1. Liverpool's rivalry with Manchester United stems from the cities' competition in the Industrial Revolution of the 19th century. Connected by the world's first inter-city railway, by road Liverpool and Manchester are separated by approximately 30 miles (48 km) along the East Lancs Road. Ranked the two biggest clubs in England by France Football magazine, Liverpool and Manchester United are the most successful English teams in both domestic and international competitions, and both clubs have a global fanbase. Viewed as one of the biggest rivalries in world football, it is considered the most famous fixture in English football. The two clubs alternated as champions between 1964 and 1967, and Manchester United became the first English team to win the European Cup in 1968, followed by Liverpool's four European Cup victories. Despite the 39 league titles and nine European Cups between them the two rivals have rarely been successful at the same time – Liverpool's run of titles in the 1970s and 1980s coincided with Manchester United's 26-year title drought, and United's success in the Premier League-era likewise coincided with Liverpool's 30-year title drought, and the two clubs have finished first and second in the league only five times. Such is the rivalry between the clubs they rarely do transfer business with each other. The last player to be transferred between the two clubs was Phil Chisnall, who moved to Liverpool from Manchester United in 1964. Ownership and finances As the owner of Anfield and founder of Liverpool, John Houlding was the club's first chairman, a position he held from its founding in 1892 until 1904. John McKenna took over as chairman after Houlding's departure. McKenna subsequently became President of the Football League. The chairmanship changed hands many times before John Smith, whose father was a shareholder of the club, took up the role in 1973. He oversaw the most successful period in Liverpool's history before stepping down in 1990. His successor was Noel White who became chairman in 1990. In August 1991 David Moores, whose family had owned the club for more than 50 years, became chairman. His uncle John Moores was also a shareholder at Liverpool and was chairman of Everton from 1961 to 1973. Moores owned 51 percent of the club, and in 2004 expressed his willingness to consider a bid for his shares in Liverpool. Moores eventually sold the club to American businessmen George Gillett and Tom Hicks on 6 February 2007. The deal valued the club and its outstanding debts at £218.9 million. The pair paid £5,000 per share, or £174.1m for the total shareholding and £44.8m to cover the club's debts. Disagreements between Gillett and Hicks, and the fans' lack of support for them, resulted in the pair looking to sell the club. Martin Broughton was appointed chairman of the club on 16 April 2010 to oversee its sale. In May 2010, accounts were released showing the holding company of the club to be £350m in debt (due to leveraged takeover) with losses of £55m, causing auditor KPMG to qualify its audit opinion. The group's creditors, including the Royal Bank of Scotland, took Gillett and Hicks to court to force them to allow the board to proceed with the sale of the club, the major asset of the holding company. A High Court judge, Mr Justice Floyd, ruled in favour of the creditors and paved the way for the sale of the club to Fenway Sports Group (formerly New England Sports Ventures), although Gillett and Hicks still had the option to appeal. Liverpool was sold to Fenway Sports Group on 15 October 2010 for £300m. Liverpool has been described as a global brand; a 2010 report valued the club's trademarks and associated intellectual property at £141m, an increase of £5m on the previous year. Liverpool was given a brand rating of AA (Very Strong). In April 2010 business magazine Forbes ranked Liverpool as the sixth most valuable football team in the world, behind Manchester United, Real Madrid, Arsenal, Barcelona and Bayern Munich; they valued the club at $822m (£532m), excluding debt. Accountants Deloitte ranked Liverpool eighth in the Deloitte Football Money League, which ranks the world's football clubs in terms of revenue. Liverpool's income in the 2009–10 season was €225.3m. According to a 2018 report by Deloitte, the club had an annual revenue of €424.2 million for the previous year, and Forbes valued the club at $1.944 billion. In 2018, annual revenue increased to €513.7 million, and Forbes valued the club at $2.183 billion. In 2019 revenue increased to €604 million (£533 million) according to Deloitte, with the club breaching the half a billion pounds mark. In April 2020, the owners of the club came under fire from fans and the media for deciding to furlough all non-playing staff during the COVID-19 pandemic. In response to this, the club made a U-turn on the decision and apologised for their initial decision. In April 2021 Forbes valued the club at $4.1 billion, a two-year increase of 88%, making it the world's fifth-most-valuable football club. Liverpool in the media Liverpool featured in the first edition of BBC's Match of the Day, which screened highlights of their match against Arsenal at Anfield on 22 August 1964. The first football match to be televised in colour was between Liverpool and West Ham United, broadcast live in March 1967. Liverpool fans featured in the Pink Floyd song "Fearless", in which they sang excerpts from "You'll Never Walk Alone". To mark the club's appearance in the 1988 FA Cup Final, Liverpool released the "Anfield Rap", a song featuring John Barnes and other members of the squad. A docudrama on the Hillsborough disaster, written by Jimmy McGovern, was screened in 1996. It featured Christopher Eccleston as Trevor Hicks, who lost two teenage daughters in the disaster, went on to campaign for safer stadiums and helped to form the Hillsborough Families Support Group. Liverpool featured in the 2001 film The 51st State, in which ex-hitman Felix DeSouza (Robert Carlyle) is a keen supporter of the team and the last scene takes place at a match between Liverpool and Manchester United. The club also featured in the 1984 children's television show Scully, about a young boy who tries to gain a trial with Liverpool. The opening scenes of the Doctor Who episode "The Halloween Apocalypse", aired in October 2021, features The Doctor (played by Jodie Whittaker) exiting the TARDIS outside Anfield as she exclaims: "Liverpool? Anfield! Klopp era, classic!". Players First-team squad Out on loan Reserves and Academy Former players Player records Club captains Since the establishment of the club in 1892, 45 players have been club captain of Liverpool F.C. Andrew Hannah became the first captain of the club after Liverpool separated from Everton and formed its own club. Alex Raisbeck, who was club captain from 1899 to 1909, was the longest serving captain before being overtaken by Steven Gerrard who served 12 seasons as Liverpool captain starting from the 2003–04 season. The present captain is Jordan Henderson, who in the 2015–16 season replaced Gerrard who moved to LA Galaxy. Player of the season Club officials Owner: Fenway Sports Group Honorary life president: David Moores Ambassadors: Ian Rush, Robbie Fowler, Michael Owen Liverpool Football Club and Athletic Grounds Limited Principal owner: John W. Henry Chairman: Tom Werner Chief executive officer: Billy Hogan Chief operating officer: Andy Hughes Source: Liverpool Football Club Directors: John W. Henry, Tom Werner, Michael Gordon, Peter Moore, Michael Egan Non-Executive Director: Kenny Dalglish Director of communications: Susan Black Director of scouting: Dave Fallows Chief scout: Barry Hunter Director of technical performance: Michael Edwards Source: Coaching and medical staff Manager: Jürgen Klopp Assistant coach: Pepijn Lijnders Assistant coach: Peter Krawietz Elite Development coach: Vitor Matos First-team goalkeeping coach: John Achterberg First-team goalkeeping coach: Cláudio Taffarel First-team assistant goalkeeping coach: Jack Robinson Head of Fitness and Conditioning: Andreas Kornmayer Head of Recovery and Performance: Dr. Andreas Schlumberger First-team fitness coach: Dr. Conall Murtagh First-team assistant fitness coach: Jordan Fairclough Club Doctor: Dr. Jim Moxon Head Physiotherapist: Lee Nobes Head of Nutrition: Mona Nemmer Academy Director: Alex Inglethorpe Source: Honours Liverpool's first trophy was the Lancashire League, which it won in the club's first season. In 1901, the club won its first League title, while the nineteenth and most recent was in 2020. Its first success in the FA Cup was in 1965. In terms of the number of trophies won, Liverpool's most successful decade was the 1980s, when the club won six League titles, two FA Cups, four League Cups, one Football League Super Cup, five Charity Shields (one shared) and two European Cups. The club has accumulated more top-flight wins and points than any other English team. Liverpool also has the highest average league finishing position (3.3) for the 50-year period to 2015 and second-highest average league finishing position for the period 1900–1999 after Arsenal, with an average league placing of 8.7. Liverpool is the most successful British club in international football with fourteen trophies, having won the European Cup/UEFA Champions League, UEFA's premier club competition, six times, an English record and only surpassed by Real Madrid and A.C. Milan. Liverpool's fifth European Cup win, in 2005, meant that the club was awarded the trophy permanently and was also awarded a multiple-winner badge. Liverpool also hold the English record of three wins in the UEFA Cup, UEFA's secondary club competition. Liverpool also hold the English record of four wins in the UEFA Super Cup. In 2019, the club won the FIFA Club World Cup for the first time, and also became the first English club to win the international treble of Club World Cup, Champions League and UEFA Super Cup. Domestic League First Division/Premier League Winners (19): 1900–01, 1905–06, 1921–22, 1922–23, 1946–47, 1963–64, 1965–66, 1972–73, 1975–76, 1976–77, 1978–79, 1979–80, 1981–82, 1982–83, 1983–84, 1985–86, 1987–88, 1989–90, 2019–20 Second Division Winners (4): 1893–94, 1895–96, 1904–05, 1961–62 Cups FA Cup Winners (7): 1964–65, 1973–74, 1985–86, 1988–89, 1991–92, 2000–01, 2005–06 Football League Cup/EFL Cup Winners (9): 1980–81, 1981–82, 1982–83, 1983–84, 1994–95, 2000–01, 2002–03, 2011–12, 2021–22 Football League Super Cup Winners (1): 1985–86 FA Charity Shield/FA Community Shield Winners (15): 1964, 1965, 1966, 1974, 1976, 1977, 1979, 1980, 1982, 1986, 1988, 1989, 1990, 2001, 2006 ( shared) Sheriff of London Charity Shield Winners (1): 1906 European European Cup/UEFA Champions League Winners (6): 1976–77, 1977–78, 1980–81, 1983–84, 2004–05, 2018–19 UEFA Cup Winners (3): 1972–73, 1975–76, 2000–01 European/UEFA Super Cup Winners (4): 1977, 2001, 2005, 2019 Worldwide FIFA Club World Cup Winners (1): 2019 Doubles and Trebles Doubles: League and FA Cup (1): 1985–86 League and League Cup (2): 1981–82, 1982–83 League and European Cup (1): 1976–77 League and UEFA Cup (2): 1972–73, 1975–76 League Cup and European Cup (1): 1980–81 Trebles: League, League Cup and European Cup (1): 1983–84 FA Cup, League Cup and UEFA Cup (1): 2000–01 See also References Footnote Bibliography </ref> External links Independent websites LFCHistory.net Statistics website Liverpool at Sky Sports Liverpool at Premier League Football clubs in England 1892 establishments in England Association football clubs established in 1892 EFL Cup winners Lancashire League (football) Former English Football League clubs FA Cup winners G-14 clubs Multi-sport clubs in the United Kingdom Premier League clubs Liv UEFA Champions League winning clubs UEFA Cup winning clubs UEFA Super Cup winning clubs Shorty Award winners	[ 0.3148069679737091, -0.023161472752690315, 0.06317993253469467, -0.9220718145370483, 0.20420204102993011, 0.22179603576660156, -0.12564000487327576, 0.41010230779647827, -0.20249798893928528, -0.434858113527298, -0.09740593284368515, 0.05435042455792427, -0.5370111465454102, 0.315314561128...
18120	https://en.wikipedia.org/wiki/Lysosome	Lysosome	A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane proteins, and its lumenal proteins. The lumen's pH (~4.5–5.0) is optimal for the enzymes involved in hydrolysis, analogous to the activity of the stomach. Besides degradation of polymers, the lysosome is involved in various cell processes, including secretion, plasma membrane repair, apoptosis, cell signaling, and energy metabolism. Lysosomes act as the waste disposal system of the cell by digesting used materials in the cytoplasm, from both inside and outside the cell. Material from outside the cell is taken up through endocytosis, while material from the inside of the cell is digested through autophagy. The sizes of the organelles vary greatly—the larger ones can be more than 10 times the size of the smaller ones. They were discovered and named by Belgian biologist Christian de Duve, who eventually received the Nobel Prize in Physiology or Medicine in 1974. Lysosomes are known to contain more than 60 different enzymes, and have more than 50 membrane proteins. Enzymes of the lysosomes are synthesised in the rough endoplasmic reticulum and exported to the Golgi apparatus upon recruitment by a complex composed of CLN6 and CLN8 proteins. The enzymes are trafficked from the Golgi apparatus to lysosomes in small vesicles, which fuse with larger acidic vesicles. Enzymes destined for a lysosome are specifically tagged with the molecule mannose 6-phosphate, so that they are properly sorted into acidified vesicles. In 2009, Marco Sardiello and co-workers discovered that the synthesis of most lysosomal enzymes and membrane proteins is controlled by transcription factor EB (TFEB), which promotes the transcription of nuclear genes. Mutations in the genes for these enzymes are responsible for more than 50 different human genetic disorders, which are collectively known as lysosomal storage diseases. These diseases result from an accumulation of specific substrates, due to the inability to break them down. These genetic defects are related to several neurodegenerative disorders, cancers, cardiovascular diseases, and aging-related diseases. Discovery Christian de Duve, the chairman of the Laboratory of Physiological Chemistry at the Catholic University of Louvain in Belgium, had been studying the mechanism of action of a pancreatic hormone insulin in liver cells. By 1949, he and his team had focused on the enzyme called glucose 6-phosphatase, which is the first crucial enzyme in sugar metabolism and the target of insulin. They already suspected that this enzyme played a key role in regulating blood sugar levels. However, even after a series of experiments, they failed to purify and isolate the enzyme from the cellular extracts. Therefore, they tried a more arduous procedure of cell fractionation, by which cellular components are separated based on their sizes using centrifugation. They succeeded in detecting the enzyme activity from the microsomal fraction. This was the crucial step in the serendipitous discovery of lysosomes. To estimate this enzyme activity, they used that of the standardized enzyme acid phosphatase and found that the activity was only 10% of the expected value. One day, the enzyme activity of purified cell fractions which had been refrigerated for five days was measured. Surprisingly, the enzyme activity was increased to normal of that of the fresh sample. The result was the same no matter how many times they repeated the estimation, and led to the conclusion that a membrane-like barrier limited the accessibility of the enzyme to its substrate, and that the enzymes were able to diffuse after a few days (and react with their substrate). They described this membrane-like barrier as a "saclike structure surrounded by a membrane and containing acid phosphatase." It became clear that this enzyme from the cell fraction came from membranous fractions, which were definitely cell organelles, and in 1955 De Duve named them "lysosomes" to reflect their digestive properties. The same year, Alex B. Novikoff from the University of Vermont visited de Duve's laboratory, and successfully obtained the first electron micrographs of the new organelle. Using a staining method for acid phosphatase, de Duve and Novikoff confirmed the location of the hydrolytic enzymes of lysosomes using light and electron microscopic studies. de Duve won the Nobel Prize in Physiology or Medicine in 1974 for this discovery. Originally, De Duve had termed the organelles the "suicide bags" or "suicide sacs" of the cells, for their hypothesized role in apoptosis. However, it has since been concluded that they only play a minor role in cell death. Function and structure Lysosomes contain a variety of enzymes, enabling the cell to break down various biomolecules it engulfs, including peptides, nucleic acids, carbohydrates, and lipids (lysosomal lipase). The enzymes responsible for this hydrolysis require an acidic environment for optimal activity. In addition to being able to break down polymers, lysosomes are capable of fusing with other organelles & digesting large structures or cellular debris; through cooperation with phagosomes, they are able to conduct autophagy, clearing out damaged structures. Similarly, they are able to break down virus particles or bacteria in phagocytosis of macrophages. The size of lysosomes varies from 0.1 μm to 1.2 μm. With a pH ranging from ~4.5–5.0, the interior of the lysosomes is acidic compared to the slightly basic cytosol (pH 7.2). The lysosomal membrane protects the cytosol, and therefore the rest of the cell, from the degradative enzymes within the lysosome. The cell is additionally protected from any lysosomal acid hydrolases that drain into the cytosol, as these enzymes are pH-sensitive and do not function well or at all in the alkaline environment of the cytosol. This ensures that cytosolic molecules and organelles are not destroyed in case there is leakage of the hydrolytic enzymes from the lysosome. The lysosome maintains its pH differential by pumping in protons (H+ ions) from the cytosol across the membrane via proton pumps and chloride ion channels. Vacuolar-ATPases are responsible for transport of protons, while the counter transport of chloride ions is performed by ClC-7 Cl−/H+ antiporter. In this way a steady acidic environment is maintained. It sources its versatile capacity for degradation by import of enzymes with specificity for different substrates; cathepsins are the major class of hydrolytic enzymes, while lysosomal alpha-glucosidase is responsible for carbohydrates, and lysosomal acid phosphatase is necessary to release phosphate groups of phospholipids. Formation Many components of animal cells are recycled by transferring them inside or embedded in sections of membrane. For instance, in endocytosis (more specifically, macropinocytosis), a portion of the cell's plasma membrane pinches off to form vesicles that will eventually fuse with an organelle within the cell. Without active replenishment, the plasma membrane would continuously decrease in size. It is thought that lysosomes participate in this dynamic membrane exchange system and are formed by a gradual maturation process from endosomes. The production of lysosomal proteins suggests one method of lysosome sustainment. Lysosomal protein genes are transcribed in the nucleus in a process that is controlled by transcription factor EB (TFEB). mRNA transcripts exit the nucleus into the cytosol, where they are translated by ribosomes. The nascent peptide chains are translocated into the rough endoplasmic reticulum, where they are modified. Lysosomal soluble proteins exit the endoplasmic reticulum via COPII-coated vesicles after recruitment by the EGRESS complex (ER-to-Golgi relaying of enzymes of the lysosomal system), which is composed of CLN6 and CLN8 proteins. COPII vesicles then deliver lysosomal enzymes to the Golgi apparatus, where a specific lysosomal tag, mannose 6-phosphate, is added to the peptides. The presence of these tags allow for binding to mannose 6-phosphate receptors in the Golgi apparatus, a phenomenon that is crucial for proper packaging into vesicles destined for the lysosomal system. Upon leaving the Golgi apparatus, the lysosomal enzyme-filled vesicle fuses with a late endosome, a relatively acidic organelle with an approximate pH of 5.5. This acidic environment causes dissociation of the lysosomal enzymes from the mannose 6-phosphate receptors. The enzymes are packed into vesicles for further transport to established lysosomes. The late endosome itself can eventually grow into a mature lysosome, as evidenced by the transport of endosomal membrane components from the lysosomes back to the endosomes. Pathogen entry As the endpoint of endocytosis, the lysosome also acts as a safeguard in preventing pathogens from being able to reach the cytoplasm before being degraded. Pathogens often hijack endocytotic pathways such as pinocytosis in order to gain entry into the cell. The lysosome prevents easy entry into the cell by hydrolyzing the biomolecules of pathogens necessary for their replication strategies; reduced Lysosomal activity results in an increase in viral infectivity, including HIV. In addition, AB5 toxins such as cholera hijack the endosomal pathway while evading lysosomal degradation. Clinical significance Lysosomes are involved in a group of genetically inherited deficiencies, or mutations called lysosomal storage diseases (LSD), inborn errors of metabolism caused by a dysfunction of one of the enzymes. The rate of incidence is estimated to be 1 in 5,000 births, and the true figure expected to be higher as many cases are likely to be undiagnosed or misdiagnosed. The primary cause is deficiency of an acid hydrolase. Other conditions are due to defects in lysosomal membrane proteins that fail to transport the enzyme, non-enzymatic soluble lysosomal proteins. The initial effect of such disorders is accumulation of specific macromolecules or monomeric compounds inside the endosomal–autophagic–lysosomal system. This results in abnormal signaling pathways, calcium homeostasis, lipid biosynthesis and degradation and intracellular trafficking, ultimately leading to pathogenetic disorders. The organs most affected are brain, viscera, bone and cartilage. There is no direct medical treatment to cure LSDs. The most common LSD is Gaucher's disease, which is due to deficiency of the enzyme glucocerebrosidase. Consequently, the enzyme substrate, the fatty acid glucosylceramide accumulates, particularly in white blood cells, which in turn affects spleen, liver, kidneys, lungs, brain and bone marrow. The disease is characterized by bruises, fatigue, anaemia, low blood platelets, osteoporosis, and enlargement of the liver and spleen. As of 2017, enzyme replacement therapy is available for treating 8 of the 50-60 known LDs. The most severe and rarely found, lysosomal storage disease is inclusion cell disease. Metachromatic leukodystrophy is another lysosomal storage disease that also affects sphingolipid metabolism. Dysfunctional lysosome activity is also heavily implicated in the biology of aging, and age-related diseases such as Alzheimer's, Parkinson's, and cardiovascular disease. Different enzymes present in Lysosomes Lysosomotropism Weak bases with lipophilic properties accumulate in acidic intracellular compartments like lysosomes. While the plasma and lysosomal membranes are permeable for neutral and uncharged species of weak bases, the charged protonated species of weak bases do not permeate biomembranes and accumulate within lysosomes. The concentration within lysosomes may reach levels 100 to 1000 fold higher than extracellular concentrations. This phenomenon is called lysosomotropism, "acid trapping" or "proton pump" effect. The amount of accumulation of lysosomotropic compounds may be estimated using a cell-based mathematical model. A significant part of the clinically approved drugs are lipophilic weak bases with lysosomotropic properties. This explains a number of pharmacological properties of these drugs, such as high tissue-to-blood concentration gradients or long tissue elimination half-lives; these properties have been found for drugs such as haloperidol, levomepromazine, and amantadine. However, high tissue concentrations and long elimination half-lives are explained also by lipophilicity and absorption of drugs to fatty tissue structures. Important lysosomal enzymes, such as acid sphingomyelinase, may be inhibited by lysosomally accumulated drugs. Such compounds are termed FIASMAs (functional inhibitor of acid sphingomyelinase) and include for example fluoxetine, sertraline, or amitriptyline. Ambroxol is a lysosomotropic drug of clinical use to treat conditions of productive cough for its mucolytic action. Ambroxol triggers the exocytosis of lysosomes via neutralization of lysosomal pH and calcium release from acidic calcium stores. Presumably for this reason, Ambroxol was also found to improve cellular function in some disease of lysosomal origin such as Parkinson's or lysosomal storage disease. Systemic lupus erythematosus Impaired lysosome function is prominent in systemic lupus erythematosus preventing macrophages and monocytes from degrading neutrophil extracellular traps and immune complexes. The failure to degrade internalized immune complexes stems from chronic mTORC2 activity, which impairs lysosome acidification. As a result, immune complexes in the lysosome recycle to the surface of macrophages causing an accumulation of nuclear antigens upstream of multiple lupus-associated pathologies. Controversy in botany By scientific convention, the term lysosome is applied to these vesicular organelles only in animals, and the term vacuole is applied to those in plants, fungi and algae (some animal cells also have vacuoles). Discoveries in plant cells since the 1970s started to challenge this definition. Plant vacuoles are found to be much more diverse in structure and function than previously thought. Some vacuoles contain their own hydrolytic enzymes and perform the classic lysosomal activity, which is autophagy. These vacuoles are therefore seen as fulfilling the role of the animal lysosome. Based on de Duve's description that "only when considered as part of a system involved directly or indirectly in intracellular digestion does the term lysosome describe a physiological unit", some botanists strongly argued that these vacuoles are lysosomes. However, this is not universally accepted as the vacuoles are strictly not similar to lysosomes, such as in their specific enzymes and lack of phagocytic functions. Vacuoles do not have catabolic activity and do not undergo exocytosis as lysosomes do. Etymology and pronunciation The word lysosome (, ) is New Latin that uses the combining forms lyso- (referring to lysis and derived from the Latin lysis, meaning "to loosen", via Ancient Greek λύσις [lúsis]), and -some, from soma, "body", yielding "body that lyses" or "lytic body". The adjectival form is lysosomal. The forms lyosome and lyosomal are much rarer; they use the lyo- form of the prefix but are often treated by readers and editors as mere unthinking replications of typos, which has no doubt been true as often as not. See also Peroxisome Cathelicidin Antimicrobial peptides Innate immune system References External links 3D structures of proteins associated with lysosome membrane Hide and Seek Foundation For Lysosomal Research Lysosomal Disease Network, a research consortium funded by the NIH through its NCATS/Rare Diseases Clinical Research Network Self-Destructive Behavior in Cells May Hold Key to a Longer Life Mutations in the Lysosomal Enzyme–Targeting Pathway and Persistent Stuttering Animation showing how lysosomes are made, and their function Vesicles Cell anatomy Organelles Lysosomal storage diseases	[ 0.14164291322231293, 0.14436009526252747, 0.1385936588048935, 0.13002701103687286, 0.24317599833011627, -0.36994966864585876, -0.4953855872154236, 0.4701502323150635, 0.18075913190841675, -0.6963358521461487, -0.2756166160106659, 0.15888921916484833, -0.7713857293128967, 0.643101155757904,...
18121	https://en.wikipedia.org/wiki/Leg%20spin	Leg spin	Leg spin is a type of spin bowling in cricket. A leg spinner bowls right-arm with a wrist spin action. The leg spinner's normal delivery causes the ball to spin from right to left (from the bowler's perspective) when the ball bounces on the pitch. For a right-handed batsman, that is away from the leg side, and this is where it gets the name leg break. Leg spinners bowl mostly leg breaks, varying them by adjusting the line and length, and amount of side spin versus topspin of the deliveries. Leg spinners also typically use variations of flight by sometimes looping the ball in the air, allowing any cross-breeze and the aerodynamic effects of the spinning ball to cause the ball to dip and drift before bouncing and spinning or "turning", sharply. Leg spinners also bowl other types of delivery, which spin differently, such as the googly. The terms 'leg spin', 'leg spinner', 'leg break' and 'leggie' are used in slightly different ways by different sources. The bowlers with the second and fourth highest number of wickets in the history of Test cricket, Shane Warne and Anil Kumble, were leg spinners. One famous example of leg spin is Warne's Ball of the Century. History In the 1970s and 1980s it was thought that leg spin would disappear from the game due to the success of West Indian, and later Australian teams, exclusively using fast bowlers. During this time Abdul Qadir of Pakistan was the highest-profile leg spinner in the world and is sometimes credited with "keeping the art alive". However, leg spin has again become popular with cricket fans and a successful part of cricket teams, driven largely by the success of Shane Warne, beginning with his spectacular Ball of the Century to Mike Gatting in 1993. Comparison with other types of bowling A left-handed bowler who bowls with the same (wrist spin) action as a leg spinner is known as a left-arm unorthodox spin bowler. The ball itself spins in the opposite direction. The same kind of trajectory, which spins from right to left on pitching, when performed by a left-arm bowler is known as left-arm orthodox spin bowling. As with all spinners, leg spinners bowl the ball far more slowly (70–90 km/h or 45–55 mph) than fast bowlers. The fastest leg spinners will sometimes top 100 km/h (60 mph). While very difficult to bowl accurately, good leg spin is considered one of the most threatening types of bowling to bat against for a right-handed batsman, since the flight and sharp turn make the ball's movement extremely hard to read, and the turn away from the right-handed batsman is more dangerous than the turn into the right-handed batsman generated by an off spinner. Any miscalculation can result in an outside edge off the bat and a catch going to the wicket-keeper or slip fielders. Alternatively, for a ball aimed outside the leg stump, the breaking may be so sharp that the ball goes behind a right-handed batsman and hits the stumps – the batsman is then said (informally) to be "bowled around his legs". A left-handed batsman has less difficulty facing leg spin bowling, because the ball moves in towards the batsman's body, meaning the batsman's legs are usually in the path of the ball if it misses the bat or takes an edge. This makes it difficult for the bowler to get the batsman out bowled or caught from a leg break. Terminology Leg spin: Some sources make the term 'leg spin' synonymous with leg break, implying that other deliveries bowled by a leg spinner do not count as 'leg spin'. However, other sources use the term 'leg spin' more widely, to include all deliveries bowled by a leg spinner, including non-leg break deliveries. Leg break: In the definition of a leg break, some sources actually include the bowler being a leg spinner, which implies that only leg spinners can bowl leg breaks; all leg breaks are bowled by leg spinners. Other sources do not include the bowler being a leg spinner in the definition of a leg break, and say a leg break is simply a delivery that spins from the legside to the offside, and so can also be bowled by other types of bowler. In this case, leg breaks are (only) mostly bowled by leg spinners. Leg spinner: The term leg spinner can be used to mean either the bowler or the leg break delivery. Leggie: The term leggie can also be used to mean either the bowler or the leg break delivery. Technique A leg break is bowled by holding the cricket ball in the palm of the hand with the seam running across under all the fingers. As the ball is released, the wrist is rotated to the left and the ball flicked by the ring finger, giving the ball an anti-clockwise spin as seen from behind. To grip the ball for a leg-spinning delivery, the ball is placed into the palm with the seam parallel to the palm. The first two fingers then spread and grip the ball, and the third and fourth fingers close together and rest against the side of the ball. The first bend of the third finger should grasp the seam. The thumb resting against the side is up to the bowler but should impart no pressure. When the ball is bowled, the third finger will apply most of the spin. The wrist is cocked as it comes down by the hip, and the wrist moves sharply from right to left as the ball is released, adding more spin. The ball is tossed up to provide flight. The batsman will see the hand with the palm facing towards them when the ball is released. Notable leg spin bowlers Players listed below have been included as they meet specific criteria which the general cricketing public would recognise as having achieved significant success in the art of leg spin bowling. For example: leading wicket-takers, and inventors of new deliveries. Shane Warne – 708 Test wickets (second all-time), one of five Wisden Cricketers of the Century Bernard Bosanquet – credited with inventing the googly B. S. Chandrasekhar – took 16 five-wicket hauls Clarrie Grimmett – 216 Test wickets Anil Kumble – 619 Test wickets (currently 4th on the list of all-time Test cricket wicket takers), best bowling in an innings of 10/74 Abdul Qadir – took 10 wickets in a match on five occasions Other deliveries bowled by leg spin bowlers Highly skilled leg spin bowlers are also able to bowl deliveries that behave unexpectedly, including the googly, which turns the opposite way to a normal leg break and the topspinner, which does not turn but dips sharply and bounces higher than other deliveries. A few leg spinners such as Abdul Qadir, Anil Kumble, Shane Warne and Mushtaq Ahmed have also mastered the flipper, a delivery that like a topspinner goes straight on landing, but floats through the air before skidding and keeping low, often dismissing batsmen leg before wicket or bowled. Another variation in the arsenal of some leg spinners is the slider, a leg break pushed out of the hand somewhat faster, so that it does not spin as much, but travels more straight on. See also Ball of the Century Flipper Googly Off break Topspinner References External links About Leg Spin – talkCricket Leg Spin Definition – Oxford Dictionaries Leg Spin Basics video – wisdomtalkies How to bowl leg spin – BBC Sport Cricket terminology Bowling (cricket)	[ 0.2242218554019928, -0.5356777310371399, -0.29869094491004944, -0.046160146594047546, -0.6878163814544678, -0.16517668962478638, 0.07650691270828247, 0.33319202065467834, -0.1930284947156906, -0.05010005459189415, 0.5000497102737427, 0.03948117792606354, -0.12394297868013382, 0.15293316543...
18123	https://en.wikipedia.org/wiki/Lisp%20machine	Lisp machine	Lisp machines are general-purpose computers designed to efficiently run Lisp as their main software and programming language, usually via hardware support. They are an example of a high-level language computer architecture, and in a sense, they were the first commercial single-user workstations. Despite being modest in number (perhaps 7,000 units total as of 1988) Lisp machines commercially pioneered many now-commonplace technologies, including effective garbage collection, laser printing, windowing systems, computer mice, high-resolution bit-mapped raster graphics, computer graphic rendering, and networking innovations such as Chaosnet. Several firms built and sold Lisp machines in the 1980s: Symbolics (3600, 3640, XL1200, MacIvory, and other models), Lisp Machines Incorporated (LMI Lambda), Texas Instruments (Explorer, MicroExplorer), and Xerox (Interlisp-D workstations). The operating systems were written in Lisp Machine Lisp, Interlisp (Xerox), and later partly in Common Lisp. History Historical context Artificial intelligence (AI) computer programs of the 1960s and 1970s intrinsically required what was then considered a huge amount of computer power, as measured in processor time and memory space. The power requirements of AI research were exacerbated by the Lisp symbolic programming language, when commercial hardware was designed and optimized for assembly- and Fortran-like programming languages. At first, the cost of such computer hardware meant that it had to be shared among many users. As integrated circuit technology shrank the size and cost of computers in the 1960s and early 1970s, and the memory needs of AI programs began to exceed the address space of the most common research computer, the Digital Equipment Corporation (DEC) PDP-10, researchers considered a new approach: a computer designed specifically to develop and run large artificial intelligence programs, and tailored to the semantics of the Lisp language. To keep the operating system (relatively) simple, these machines would not be shared, but would be dedicated to single users. Initial development In 1973, Richard Greenblatt and Thomas Knight, programmers at Massachusetts Institute of Technology (MIT) Artificial Intelligence Laboratory (AI Lab), began what would become the MIT Lisp Machine Project when they first began building a computer hardwired to run certain basic Lisp operations, rather than run them in software, in a 24-bit tagged architecture. The machine also did incremental (or Arena) garbage collection. More specifically, since Lisp variables are typed at runtime rather than compile time, a simple addition of two variables could take five times as long on conventional hardware, due to test and branch instructions. Lisp Machines ran the tests in parallel with the more conventional single instruction additions. If the simultaneous tests failed, then the result was discarded and recomputed; this meant in many cases a speed increase by several factors. This simultaneous checking approach was used as well in testing the bounds of arrays when referenced, and other memory management necessities (not merely garbage collection or arrays). Type checking was further improved and automated when the conventional byte word of 32-bits was lengthened to 36-bits for Symbolics 3600-model Lisp machines and eventually to 40-bits or more (usually, the excess bits not accounted for by the following were used for error-correcting codes). The first group of extra bits were used to hold type data, making the machine a tagged architecture, and the remaining bits were used to implement CDR coding (wherein the usual linked list elements are compressed to occupy roughly half the space), aiding garbage collection by reportedly an order of magnitude. A further improvement was two microcode instructions which specifically supported Lisp functions, reducing the cost of calling a function to as little as 20 clock cycles, in some Symbolics implementations. The first machine was called the CONS machine (named after the list construction operator cons in Lisp). Often it was affectionately referred to as the Knight machine, perhaps since Knight wrote his master's thesis on the subject; it was extremely well received. It was subsequently improved into a version called CADR (a pun; in Lisp, the cadr function, which returns the second item of a list, is pronounced or , as some pronounce the word "cadre") which was based on essentially the same architecture. About 25 of what were essentially prototype CADRs were sold within and without MIT for ~$50,000; it quickly became the favorite machine for hacking- many of the most favored software tools were quickly ported to it (e.g. Emacs was ported from ITS in 1975). It was so well received at an AI conference held at MIT in 1978 that Defense Advanced Research Projects Agency (DARPA) began funding its development. Commercializing MIT Lisp machine technology In 1979, Russell Noftsker, being convinced that Lisp machines had a bright commercial future due to the strength of the Lisp language and the enabling factor of hardware acceleration, proposed to Greenblatt that they commercialize the technology. In a counter-intuitive move for an AI Lab hacker, Greenblatt acquiesced, hoping perhaps that he could recreate the informal and productive atmosphere of the Lab in a real business. These ideas and goals were considerably different from those of Noftsker. The two negotiated at length, but neither would compromise. As the proposed firm could succeed only with the full and undivided assistance of the AI Lab hackers as a group, Noftsker and Greenblatt decided that the fate of the enterprise was up to them, and so the choice should be left to the hackers. The ensuing discussions of the choice divided the lab into two factions. In February 1979, matters came to a head. The hackers sided with Noftsker, believing that a commercial venture fund-backed firm had a better chance of surviving and commercializing Lisp machines than Greenblatt's proposed self-sustaining start-up. Greenblatt lost the battle. It was at this juncture that Symbolics, Noftsker's enterprise, slowly came together. While Noftsker was paying his staff a salary, he had no building or any equipment for the hackers to work on. He bargained with Patrick Winston that, in exchange for allowing Symbolics' staff to keep working out of MIT, Symbolics would let MIT use internally and freely all the software Symbolics developed. A consultant from CDC, who was trying to put together a natural language computer application with a group of West-coast programmers, came to Greenblatt, seeking a Lisp machine for his group to work with, about eight months after the disastrous conference with Noftsker. Greenblatt had decided to start his own rival Lisp machine firm, but he had done nothing. The consultant, Alexander Jacobson, decided that the only way Greenblatt was going to start the firm and build the Lisp machines that Jacobson desperately needed was if Jacobson pushed and otherwise helped Greenblatt launch the firm. Jacobson pulled together business plans, a board, a partner for Greenblatt (one F. Stephen Wyle). The newfound firm was named LISP Machine, Inc. (LMI), and was funded by CDC orders, via Jacobson. Around this time Symbolics (Noftsker's firm) began operating. It had been hindered by Noftsker's promise to give Greenblatt a year's head start, and by severe delays in procuring venture capital. Symbolics still had the major advantage that while 3 or 4 of the AI Lab hackers had gone to work for Greenblatt, a solid 14 other hackers had signed onto Symbolics. Two AI Lab people were not hired by either: Richard Stallman and Marvin Minsky. Stallman, however, blamed Symbolics for the decline of the hacker community that had centered around the AI lab. For two years, from 1982 to the end of 1983, Stallman worked by himself to clone the output of the Symbolics programmers, with the aim of preventing them from gaining a monopoly on the lab's computers. Regardless, after a series of internal battles, Symbolics did get off the ground in 1980/1981, selling the CADR as the LM-2, while Lisp Machines, Inc. sold it as the LMI-CADR. Symbolics did not intend to produce many LM-2s, since the 3600 family of Lisp machines was supposed to ship quickly, but the 3600s were repeatedly delayed, and Symbolics ended up producing ~100 LM-2s, each of which sold for $70,000. Both firms developed second-generation products based on the CADR: the Symbolics 3600 and the LMI-LAMBDA (of which LMI managed to sell ~200). The 3600, which shipped a year late, expanded on the CADR by widening the machine word to 36-bits, expanding the address space to 28-bits, and adding hardware to accelerate certain common functions that were implemented in microcode on the CADR. The LMI-LAMBDA, which came out a year after the 3600, in 1983, was compatible with the CADR (it could run CADR microcode), but hardware differences existed. Texas Instruments (TI) joined the fray when it licensed the LMI-LAMBDA design and produced its own variant, the TI Explorer. Some of the LMI-LAMBDAs and the TI Explorer were dual systems with both a Lisp and a Unix processor. TI also developed a 32-bit microprocessor version of its Lisp CPU for the TI Explorer. This Lisp chip also was used for the MicroExplorer – a NuBus board for the Apple Macintosh II (NuBus was initially developed at MIT for use in Lisp machines). Symbolics continued to develop the 3600 family and its operating system, Genera, and produced the Ivory, a VLSI implementation of the Symbolics architecture. Starting in 1987, several machines based on the Ivory processor were developed: boards for Suns and Macs, stand-alone workstations and even embedded systems (I-Machine Custom LSI, 32 bit address, Symbolics XL-400, UX-400, MacIvory II; in 1989 available platforms were Symbolics XL-1200, MacIvory III, UX-1200, Zora, NXP1000 "pizza box"). Texas Instruments shrank the Explorer into silicon as the MicroExplorer which was offered as a card for the Apple Mac II. LMI abandoned the CADR architecture and developed its own K-Machine, but LMI went bankrupt before the machine could be brought to market. Before its demise, LMI was working on a distributed system for the LAMBDA using Moby space. These machines had hardware support for various primitive Lisp operations (data type testing, CDR coding) and also hardware support for incremental garbage collection. They ran large Lisp programs very efficiently. The Symbolics machine was competitive against many commercial super minicomputers, but was never adapted for conventional purposes. The Symbolics Lisp Machines were also sold to some non-AI markets like computer graphics, modeling, and animation. The MIT-derived Lisp machines ran a Lisp dialect named Lisp Machine Lisp, descended from MIT's Maclisp. The operating systems were written from the ground up in Lisp, often using object-oriented extensions. Later, these Lisp machines also supported various versions of Common Lisp (with Flavors, New Flavors, and Common Lisp Object System (CLOS)). Interlisp, BBN, and Xerox Bolt, Beranek and Newman (BBN) developed its own Lisp machine, named Jericho, which ran a version of Interlisp. It was never marketed. Frustrated, the whole AI group resigned, and were hired mostly by Xerox. So, Xerox Palo Alto Research Center had, simultaneously with Greenblatt's own development at MIT, developed their own Lisp machines which were designed to run InterLisp (and later Common Lisp). The same hardware was used with different software also as Smalltalk machines and as the Xerox Star office system. These included the Xerox 1100, Dolphin (1979); the Xerox 1132, Dorado; the Xerox 1108, Dandelion (1981); the Xerox 1109, Dandetiger; and the Xerox 1186/6085, Daybreak. The operating system of the Xerox Lisp machines has also been ported to a virtual machine and is available for several platforms as a product named Medley. The Xerox machine was well known for its advanced development environment (InterLisp-D), the ROOMS window manager, for its early graphical user interface and for novel applications like NoteCards (one of the first hypertext applications). Xerox also worked on a Lisp machine based on reduced instruction set computing (RISC), using the 'Xerox Common Lisp Processor' and planned to bring it to market by 1987, which did not occur. Integrated Inference Machines In the mid-1980s, Integrated Inference Machines (IIM) built prototypes of Lisp machines named Inferstar. Developments of Lisp machines outside the United States In 1984–85 a UK firm, Racal-Norsk, a joint subsidiary of Racal and Norsk Data, attempted to repurpose Norsk Data's ND-500 supermini as a microcoded Lisp machine, running CADR software: the Knowledge Processing System (KPS). There were several attempts by Japanese manufacturers to enter the Lisp machine market: the Fujitsu Facom-alpha mainframe co-processor, NTT's Elis, Toshiba's AI processor (AIP) and NEC's LIME. Several university research efforts produced working prototypes, among them are Kobe University's TAKITAC-7, RIKEN's FLATS, and Osaka University's EVLIS. In France, two Lisp Machine projects arose: M3L at Toulouse Paul Sabatier University and later MAIA. In Germany Siemens designed the RISC-based Lisp co-processor COLIBRI. End of the Lisp machines With the onset of the AI winter and the early beginnings of the microcomputer revolution, which would sweep away the minicomputer and workstation makers, cheaper desktop PCs soon could run Lisp programs even faster than Lisp machines, with no use of special purpose hardware. Their high profit margin hardware business eliminated, most Lisp machine makers had gone out of business by the early 90s, leaving only software based firms like Lucid Inc. or hardware makers who had switched to software and services to avoid the crash. , besides Xerox and TI, Symbolics is the only Lisp machine firm still operating, selling the Open Genera Lisp machine software environment and the Macsyma computer algebra system. Legacy Several attempts to write open-source emulators for various Lisp Machines have been made: CADR Emulation, Symbolics L Lisp Machine Emulation, the E3 Project (TI Explorer II Emulation), Meroko (TI Explorer I), and Nevermore (TI Explorer I). On 3 October 2005, the MIT released the CADR Lisp Machine source code as open source. In September 2014, Alexander Burger, developer of PicoLisp, announced PilMCU, an implementation of PicoLisp in hardware. The Bitsavers' PDF Document Archive has PDF versions of the extensive documentation for the Symbolics Lisp Machines, the TI Explorer and MicroExplorer Lisp Machines and the Xerox Interlisp-D Lisp Machines. Applications Domains using the Lisp machines were mostly in the wide field of artificial intelligence applications, but also in computer graphics, medical image processing, and many others. The main commercial expert systems of the 80s were available: Intellicorp's Knowledge Engineering Environment (KEE), Knowledge Craft, from The Carnegie Group Inc., and ART (Automated Reasoning Tool) from Inference Corporation. Technical overview Initially the Lisp machines were designed as personal workstations for software development in Lisp. They were used by one person and offered no multi-user mode. The machines provided a large, black and white, bitmap display, keyboard and mouse, network adapter, local hard disks, more than 1 MB RAM, serial interfaces, and a local bus for extension cards. Color graphics cards, tape drives, and laser printers were optional. The processor did not run Lisp directly, but was a stack machine with instructions optimized for compiled Lisp. The early Lisp machines used microcode to provide the instruction set. For several operations, type checking and dispatching was done in hardware at runtime. For example, only one addition operation could be used with various numeric types (integer, float, rational, and complex numbers). The result was a very compact compiled representation of Lisp code. The following example uses a function that counts the number of elements of a list for which a predicate returns true. (defun example-count (predicate list) (let ((count 0)) (dolist (i list count) (when (funcall predicate i) (incf count))))) The disassembled machine code for above function (for the Ivory microprocessor from Symbolics): Command: (disassemble (compile #'example-count)) 0 ENTRY: 2 REQUIRED, 0 OPTIONAL ;Creating PREDICATE and LIST 2 PUSH 0 ;Creating COUNT 3 PUSH FP\|3 ;LIST 4 PUSH NIL ;Creating I 5 BRANCH 15 6 SET-TO-CDR-PUSH-CAR FP\|5 7 SET-SP-TO-ADDRESS-SAVE-TOS SP\|-1 10 START-CALL FP\|2 ;PREDICATE 11 PUSH FP\|6 ;I 12 FINISH-CALL-1-VALUE 13 BRANCH-FALSE 15 14 INCREMENT FP\|4 ;COUNT 15 ENDP FP\|5 16 BRANCH-FALSE 6 17 SET-SP-TO-ADDRESS SP\|-2 20 RETURN-SINGLE-STACK The operating system used virtual memory to provide a large address space. Memory management was done with garbage collection. All code shared a single address space. All data objects were stored with a tag in memory, so that the type could be determined at runtime. Multiple execution threads were supported and termed processes. All processes ran in the one address space. All operating system software was written in Lisp. Xerox used Interlisp. Symbolics, LMI, and TI used Lisp Machine Lisp (descendant of MacLisp). With the appearance of Common Lisp, Common Lisp was supported on the Lisp Machines and some system software was ported to Common Lisp or later written in Common Lisp. Some later Lisp machines (like the TI MicroExplorer, the Symbolics MacIvory or the Symbolics UX400/1200) were no longer complete workstations, but boards designed to be embedded in host computers: Apple Macintosh II and SUN 3 or 4. Some Lisp machines, such as the Symbolics XL1200, had extensive graphics abilities using special graphics boards. These machines were used in domains like medical image processing, 3D animation, and CAD. See also ICAD – example of knowledge-based engineering software originally developed on a Lisp machine that was useful enough to be then ported via Common Lisp to Unix Orphaned technology References General "LISP Machine Progress Report", Alan Bawden, Richard Greenblatt, Jack Holloway, Thomas Knight, David A. Moon, Daniel Weinreb, AI Lab memos, AI-444, 1977. "CADR", Thomas Knight, David A. Moon, Jack Holloway, Guy L. Steele. AI Lab memos, AIM-528, 1979. "Design of LISP-based Processors, or SCHEME: A Dielectric LISP, or Finite Memories Considered Harmful, or LAMBDA: The Ultimate Opcode", Guy Lewis Steele, Gerald Jay Sussman, AI Lab memo, AIM-514, 1979 David A. Moon. Chaosnet. A.I. Memo 628, Massachusetts Institute of Technology Artificial Intelligence Laboratory, June 1981. "Implementation of a List Processing Machine". Tom Knight, Master's thesis. Lisp Machine manual, 6th ed. Richard Stallman, Daniel Weinreb, David A. Moon. 1984. "Anatomy of a LISP Machine", Paul Graham, AI Expert, December 1988 Free as in Freedom: Richard Stallman's Crusade for Free Software External links Symbolics website Medley Bitsavers, PDF documents LMI documentation MIT CONS documentation MIT CADR documentation Lisp Machine Manual, Chinual "The Lisp Machine manual, 4th Edition, July 1981" "The Lisp Machine manual, 6th Edition, HTML/XSL version" "The Lisp Machine manual" Information and code for LMI Lambda and LMI K-Machine – A set of links and locally stored documents regarding all manner of Lisp machines "A Few Things I Know About LISP Machines" – A set of links, mostly discussion of buying Lisp machines Ralf Möller's Symbolics Lisp Machine Museum Vintage Computer Festival pictures of some Lisp machines, one running Genera LISPMachine.net – Lisp Books and Information Lisp machines timeline – a timeline of Symbolics' and others' Lisp machines "Présentation Générale du projet M3L" – An account of French efforts in the same vein Discussion "If It Works, It's Not AI: A Commercial Look at Artificial Intelligence startups" "Symbolics, Inc.: A failure of Heterogenous engineering" – (PDF) "My Lisp Experiences and the Development of GNU Emacs" – transcript of a speech Richard Stallman gave about Emacs, Lisp, and Lisp machines Lisp (programming language) Computer workstations History of artificial intelligence High-level language computer architecture	[ -0.14856356382369995, 0.24419479072093964, 0.02839331142604351, 0.27763497829437256, -0.0686684250831604, 0.10499390214681625, -0.027896644547581673, 0.3126368224620819, -0.23629792034626007, -0.6110825538635254, -0.6500332951545715, 0.3868480622768402, -0.7170535922050476, -0.347416162490...
18125	https://en.wikipedia.org/wiki/Links%20%28web%20browser%29	Links (web browser)	Links is an open source text and graphical web browser with a pull-down menu system. It renders complex pages, has partial HTML 4.0 support (including tables and frames and support for multiple character sets such as UTF-8), supports color and monochrome terminals and allows horizontal scrolling. It is intended for users who want to retain many typical elements of graphical user interfaces (pop-up windows, menus etc.) in a text-only environment. The original version of Links was developed by Mikuláš Patočka in the Czech Republic. His group Twibright Labs later developed version 2 of the Links browser, that displays graphics, renders fonts in different sizes (with spatial anti-aliasing), but does not support JavaScript any more (it used to, up to version 2.1pre28). The resulting browser is very fast, but it does not display many pages as they were intended. The graphical mode works even on Unix systems without the X Window System or any other window environment, using either SVGAlib or the framebuffer of the system's graphics card. The source code is available on Github. Graphics stack The graphics stack has several peculiarities unusual for a web browser. The fonts displayed by Links are not derived from the system, but compiled into the binary as grayscale bitmaps in Portable Network Graphics (PNG) format. This allows the browser to be one executable file independent of the system libraries. However this increases the size of the executable to about 5 MB. The fonts are anti-aliased without hinting and for small line pitch an artificial sharpening is employed to increase legibility. Subpixel sampling further increases legibility on LCD displays. This allowed Links to have anti-aliased fonts at a time when anti-aliased font libraries were uncommon. All graphic elements (images and text) are first converted from given gamma space (according to known or assumed gamma information in PNG, JPEG etc.) through known user gamma setting into a 48 bits per pixel photometrically linear space where they are resampled with bilinear resampling to the target size, possibly taking aspect ratio correction into account. Then the data are passed through high-performance restartable dithering engine which is used regardless of monitor bit depth, i.e., also for 24 bits per pixel colour. This Floyd-Steinberg dithering engine takes into account the gamma characteristics of the monitor and uses 768 KiB of dithering tables to avoid time expensive calculations. A technique similar to self-modifying code, function templates, is used to maximise the speed of the dithering engine without using assembly language optimization. Images which are scaled down also use subpixel sampling on LCD to increase level of detail. The reason for this high quality processing is: provide proper realistic up and down sampling of images, and photorealistic display regardless of the monitor gamma, without colour fringing caused by 8-bit gamma correction built into the X server. It also increases the perceived colour depth over 24 bits per pixel. Links has graphics drivers for the X Server, Linux framebuffer, svgalib, OS/2 PMShell and AtheOS GUI. Forks ELinks Experimental/Enhanced Links (ELinks) is a fork of Links led by Petr Baudis. It is based on Links 0.9. It has a more open development and incorporates patches from other Links versions (such as additional extension scripting in Lua) and from Internet users. Hacked Links Hacked Links is another version of the Links browser which has merged some of Elinks' features into Links 2. Andrey Mirtchovski has ported it to Plan 9 from Bell Labs. It is considered a good browser on that operating system, though some users have complained about its inability to cut and paste with the Plan 9 snarf buffer. , the last release of Hacked Links is that of July 9, 2003 with some further changes unreleased. Other Links was also ported to run on the Sony PSP platform as PSPRadio by Rafael Cabezas with the last version (2.1pre23_PSP_r1261) released on February 6, 2007. The BeOS port was updated by François Revol who also added GUI support. It also runs on Haiku. References External links User documentation for Links Links-Hacked project Links for OS X on PowerPC and Intel (forum) Linkx fork Original Links Source Code 1999 software Free web browsers OS/2 web browsers MacOS web browsers POSIX web browsers SVGAlib programs Text-based web browsers Web browsers for Plan 9	[ 0.16920706629753113, 0.26409924030303955, 0.1673663854598999, 0.017726736143231392, -0.18503178656101227, -0.2790139615535736, 0.03754851594567299, 0.5790871977806091, -0.4753667414188385, -0.8231791257858276, -0.5292567610740662, -0.017991693690419197, -0.5854766964912415, 0.2843492627143...
18126	https://en.wikipedia.org/wiki/Learning%20object	Learning object	A learning object is "a collection of content items, practice items, and assessment items that are combined based on a single learning objective". The term is credited to Wayne Hodgins, and dates from a working group in 1994 bearing the name. The concept encompassed by 'Learning Objects' is known by numerous other terms, including: content objects, chunks, educational objects, information objects, intelligent objects, knowledge bits, knowledge objects, learning components, media objects, reusable curriculum components, nuggets, reusable information objects, reusable learning objects, testable reusable units of cognition, training components, and units of learning. The core idea of the use of learning objects is characterized by the following: discoverability, reusability, and interoperability. To support discoverability, learning objects are described by Learning Object Metadata, formalized as IEEE 1484.12 Learning object metadata. To support reusability, the IMS Consortium proposed a series of specifications such as the IMS Content package. And to support interoperability, the U.S. military's Advanced Distributed Learning organization created the Sharable Content Object Reference Model. Learning objects were designed in order to reduce the cost of learning, standardize learning content, and to enable the use and reuse of learning content by learning management systems. Definitions The Institute of Electrical and Electronics Engineers (IEEE) defines a learning object as "any entity, digital or non-digital, that may be used for learning, education or training". Chiappe defined Learning Objects as: "A digital self-contained and reusable entity, with a clear educational purpose, with at least three internal and editable components: content, learning activities and elements of context. The learning objects must have an external structure of information to facilitate their identification, storage and retrieval: the metadata." The following definitions focus on the relation between learning object and digital media. RLO-CETL, a British inter-university Learning Objects Center, defines "reusable learning objects" as "web-based interactive chunks of e-learning designed to explain a stand-alone learning objective". Daniel Rehak and Robin Mason define it as "a digitized entity which can be used, reused or referenced during technology supported learning". Adapting a definition from the Wisconsin Online Resource Center, Robert J. Beck suggests that learning objects have the following key characteristics: Learning objects are a new way of thinking about learning content. Traditionally, content comes in a several hour chunk. Learning objects are much smaller units of learning, typically ranging from 2 minutes to 15 minutes. Are self-contained – each learning object can be taken independently Are reusable – a single learning object may be used in multiple contexts for multiple purposes Can be aggregated – learning objects can be grouped into larger collections of content, including traditional course structures Are tagged with metadata – every learning object has descriptive information allowing it to be easily found by a search Components The following is a list of some of the types of information that may be included in a learning object and its metadata: General Course Descriptive Data, including: course identifiers, language of content (English, Spanish, etc.), subject area (Maths, Reading, etc.), descriptive text, descriptive keywords Life Cycle, including: version, status Instructional Content, including: text, web pages, images, sound, video Glossary of Terms, including: terms, definition, acronyms Quizzes and Assessments, including: questions, answers Rights, including: cost, copyrights, restrictions on Use Relationships to Other Courses, including prerequisite courses Educational Level, including: grade level, age range, typical learning time, and difficulty. [IEEE 1484.12.1:2002] Typology as defined by Churchill (2007): presentation, practice, simulation, conceptual models, information, and contextual representation Metadata One of the key issues in using learning objects is their identification by search engines or content management systems. This is usually facilitated by assigning descriptive learning object metadata. Just as a book in a library has a record in the card catalog, learning objects must also be tagged with metadata. The most important pieces of metadata typically associated with a learning object include: objective: The educational objective the learning object is instructing prerequisites: The list of skills (typically represented as objectives) which the learner must know before viewing the learning object topic: Typically represented in a taxonomy, the topic the learning object is instructing interactivity: The Interaction Model of the learning object. technology requirements: The required system requirements to view the learning object. Mutability A mutated learning object is, according to Michael Shaw, a learning object that has been "re-purposed and/or re-engineered, changed or simply re-used in some way different from its original intended design". Shaw also introduces the term "contextual learning object", to describe a learning object that has been "designed to have specific meaning and purpose to an intended learner". This may be useful if the intent involves just-in-time learning and the individual needs of individual learners. Portability Before any institution invests a great deal of time and energy into building high-quality e-learning content (which can cost over $10,000 per classroom hour), it needs to consider how this content can be easily loaded into a Learning Management System. It is possible for example, to package learning objects with SCORM specification and load it in Moodle Learning Management System or Desire2Learn Learning Environment. If all of the properties of a course can be precisely defined in a common format, the content can be serialized into a standard format such as XML and loaded into other systems. When it is considered that some e-learning courses need to include video, mathematical equations using MathML, chemistry equations using CML and other complex structures, the issues become very complex, especially if the systems needs to understand and validate each structure and then place it correctly in a database. Criticism In 2001, David Wiley criticized learning object theory in his paper, The Reusability Paradox which is summarized by D'Arcy Norman as, If a learning object is useful in a particular context, by definition it is not reusable in a different context. If a learning object is reusable in many contexts, it isn’t particularly useful in any. In Three Objections to Learning Objects and E-learning Standards, Norm Friesen, Canada Research Chair in E-Learning Practices at Thompson Rivers University, points out that the word neutrality in itself implies a state or position that is antithetical ... to pedagogy and teaching. See also Instructional materials Intelligent tutoring system North Carolina Learning Object Repository (NCLOR) Serious games References Further reading . . . Spanish Draf: Blog de Andrés Chiappe - Objetos de Aprendizaje. . . Churchill, D. (2007). Towards a useful classification of learning objects. Educational Technology Research & Development, 55(5), 479-497. Innayah: Creating An Audio Script with Learning Object, unpublished, 2013. External links The Learning Objects at Milwaukee's Center for International Education. Data management Educational materials Educational technology	[ 0.19028669595718384, 0.1373259574174881, -0.3239454925060272, 0.6962340474128723, 0.15022610127925873, -0.19360172748565674, 0.0547330267727375, 0.06031014397740364, -0.11943031847476959, -0.5215544700622559, -0.8021461963653564, 0.165019229054451, 0.21895284950733185, 0.30884963274002075,...
18129	https://en.wikipedia.org/wiki/List%20of%20Labour%20parties	List of Labour parties	The name Labour (or Labor) Party, or similar, is used by political parties around the world, particularly in countries of the Commonwealth of Nations. They are usually, but not exclusively, social-democratic or democratic-socialist and traditionally allied to trade unions and the labour movement. Many labour parties are members of the Socialist International and/or participants of the Progressive Alliance. Active Labour parties Historical Labour parties See also Labour Party (disambiguation) Communist party List of communist parties Democratic Socialist Party (disambiguation) Labour government Labour movement List of left-wing political parties Social Democratic Party List of social democratic parties Socialist Labour Party (disambiguation) Socialist Party Socialist Workers Party (disambiguation) Workers' Party Socialism Labour	[ 0.4125857353210449, -0.016502000391483307, -0.16614742577075958, -0.19036586582660675, -0.6117473840713501, 0.6163699626922607, 0.00950077548623085, 0.6613184809684753, -1.0506932735443115, 0.028248107060790062, -0.2905237674713135, -0.06417940557003021, -0.47730937600135803, 0.32877966761...
18130	https://en.wikipedia.org/wiki/Louisiana	Louisiana	Louisiana (Standard French: ; ; French: La Louisiane [/lwi.zjan/]) is a state in the Deep South and South Central regions of the United States. It is the 20th-smallest by area and the 25th most populous of the 50 U.S. states. Louisiana is bordered by the state of Texas to the west, Arkansas to the north, Mississippi to the east, and the Gulf of Mexico to the south. A large part of its eastern boundary is demarcated by the Mississippi River. Louisiana is the only U.S. state with political subdivisions termed parishes, which are equivalent to counties, making it one of only two U.S. states not subdivided into counties (the other being Alaska). The state's capital is Baton Rouge, and its largest city is New Orleans. Much of the state's lands were formed from sediment washed down the Mississippi River, leaving enormous deltas and vast areas of coastal marsh and swamp. These contain a rich southern biota; typical examples include birds such as ibises and egrets. There are also many species of tree frogs, and fish such as sturgeon and paddlefish. In more elevated areas, fire is a natural process in the landscape and has produced extensive areas of longleaf pine forest and wet savannas. These support an exceptionally large number of plant species, including many species of terrestrial orchids and carnivorous plants. Louisiana has more Native American tribes than any other southern state, including four that are federally recognized, ten that are state recognized, and four that have not received recognition. Some Louisiana urban environments have a multicultural, multilingual heritage, being so strongly influenced by a mixture of 18th–century French, Haitian, Spanish, French Canadian, Native American, and African cultures that they are considered to be exceptional in the U.S. Before the American purchase of the territory in 1803, the present–day U.S. state of Louisiana had been both a French colony and for a brief period a Spanish one. In addition, colonists imported numerous African people as slaves in the 18th century. Many came from peoples of the same region of West Africa, thus concentrating their culture; Filipinos also arrived during colonial Louisiana. In the post–Civil War environment, Anglo Americans increased the pressure for Anglicization, and in 1921, English was for a time made the sole language of instruction in Louisiana schools before a policy of multilingualism was revived in 1974. There has never been an official language in Louisiana, and the state constitution enumerates "the right of the people to preserve, foster, and promote their respective historic, linguistic, and cultural origins." Based on national averages, Louisiana frequently ranks low among the U.S. in terms of health, education, and development, and high in measures of poverty. In 2018, Louisiana was ranked as the least healthy state in the country, with high levels of drug-related deaths and excessive alcohol consumption, while it has had the highest homicide rate in the United States since at least the 1990s. Etymology Louisiana was named after Louis XIV, King of France from 1643 to 1715. When René-Robert Cavelier, Sieur de La Salle claimed the territory drained by the Mississippi River for France, he named it . The suffix –ana (or –ane) is a Latin suffix that can refer to "information relating to a particular individual, subject, or place." Thus, roughly, Louis + ana carries the idea of "related to Louis." Once part of the French colonial empire, the Louisiana Territory stretched from present–day Mobile Bay to just north of the present–day Canada–United States border, including a small part of what are now the Canadian provinces of Alberta and Saskatchewan. History Pre–colonial history The area of Louisiana is the place of origin of the Mound Builders culture during the Middle Archaic period, in the 4th millennium BC. The sites of Caney and Frenchman's Bend have been securely dated to 5600–5000 BP (about 3700–3100 BC), demonstrating that seasonal hunter-gatherers from around this time organized to build complex earthwork constructions in what is now northern Louisiana. The Watson Brake site near present-day Monroe has an eleven-mound complex, it was built about 5400 BP (3500 BC). These discoveries overturned previous assumptions in archaeology that such complex mounds were built only by cultures of more settled peoples who were dependent on maize cultivation. The Hedgepeth Site in Lincoln Parish is more recent, dated to 5200–4500 BP (3300–2600 BC). Nearly 2,000 years later, Poverty Point was built; it is the largest and best-known Late Archaic site in the state. The city of modern–day Epps developed near it. The Poverty Point culture may have reached its peak around 1500 BC, making it the first complex culture, and possibly the first tribal culture in North America. It lasted until approximately 700 BC. The Poverty Point culture was followed by the Tchefuncte and Lake Cormorant cultures of the Tchula period, local manifestations of Early Woodland period. The Tchefuncte culture were the first people in the area of Louisiana to make large amounts of pottery. These cultures lasted until AD 200. The Middle Woodland period started in Louisiana with the Marksville culture in the southern and eastern part of the state, reaching across the Mississippi River to the east around Natchez, and the Fourche Maline culture in the northwestern part of the state. The Marksville culture was named after the Marksville Prehistoric Indian Site in Avoyelles Parish. These cultures were contemporaneous with the Hopewell cultures of present-day Ohio and Illinois, and participated in the Hopewell Exchange Network. Trade with peoples to the southwest brought the bow and arrow. The first burial mounds were built at this time. Political power began to be consolidated, as the first platform mounds at ritual centers were constructed for the developing hereditary political and religious leadership. By 400 the Late Woodland period had begun with the Baytown culture, Troyville culture, and Coastal Troyville during the Baytown period and were succeeded by the Coles Creek cultures. Where the Baytown peoples built dispersed settlements, the Troyville people instead continued building major earthwork centers. Population increased dramatically and there is strong evidence of a growing cultural and political complexity. Many Coles Creek sites were erected over earlier Woodland period mortuary mounds. Scholars have speculated that emerging elites were symbolically and physically appropriating dead ancestors to emphasize and project their own authority. The Mississippian period in Louisiana was when the Plaquemine and the Caddoan Mississippian cultures developed, and the peoples adopted extensive maize agriculture, cultivating different strains of the plant by saving seeds, selecting for certain characteristics, etc. The Plaquemine culture in the lower Mississippi River Valley in western Mississippi and eastern Louisiana began in 1200 and continued to about 1600. Examples in Louisiana include the Medora Site, the archaeological type site for the culture in West Baton Rouge Parish whose characteristics helped define the culture, the Atchafalaya Basin Mounds in St. Mary Parish, the Fitzhugh Mounds in Madison Parish, the Scott Place Mounds in Union Parish, and the Sims Site in St. Charles Parish. Plaquemine culture was contemporaneous with the Middle Mississippian culture that is represented by its largest settlement, the Cahokia site in Illinois east of St. Louis, Missouri. At its peak Cahokia is estimated to have had a population of more than 20,000. The Plaquemine culture is considered ancestral to the historic Natchez and Taensa peoples, whose descendants encountered Europeans in the colonial era. By 1000 in the northwestern part of the state, the Fourche Maline culture had evolved into the Caddoan Mississippian culture. The Caddoan Mississippians occupied a large territory, including what is now eastern Oklahoma, western Arkansas, northeast Texas, and northwest Louisiana. Archaeological evidence has demonstrated that the cultural continuity is unbroken from prehistory to the present. The Caddo and related Caddo-language speakers in prehistoric times and at first European contact were the direct ancestors of the modern Caddo Nation of Oklahoma of today. Significant Caddoan Mississippian archaeological sites in Louisiana include Belcher Mound Site in Caddo Parish and Gahagan Mounds Site in Red River Parish. Many current place names in Louisiana, including Atchafalaya, Natchitouches (now spelled Natchitoches), Caddo, Houma, Tangipahoa, and Avoyel (as Avoyelles), are transliterations of those used in various Native American languages. Exploration and colonization by Europeans The first European explorers to visit Louisiana came in 1528 when a Spanish expedition led by Pánfilo de Narváez located the mouth of the Mississippi River. In 1542, Hernando de Soto's expedition skirted to the north and west of the state (encountering Caddo and Tunica groups) and then followed the Mississippi River down to the Gulf of Mexico in 1543. Spanish interest in Louisiana faded away for a century and a half. In the late 17th century, French and French Canadian expeditions, which included sovereign, religious and commercial aims, established a foothold on the Mississippi River and Gulf Coast. With its first settlements, France laid claim to a vast region of North America and set out to establish a commercial empire and French nation stretching from the Gulf of Mexico to Canada. In 1682, the French explorer Robert Cavelier de La Salle named the region Louisiana to honor King Louis XIV of France. The first permanent settlement, Fort Maurepas (at what is now Ocean Springs, Mississippi, near Biloxi), was founded in 1699 by Pierre Le Moyne d'Iberville, a French military officer from Canada. By then the French had also built a small fort at the mouth of the Mississippi at a settlement they named La Balise (or La Balize), "seamark" in French. By 1721 they built a wooden lighthouse-type structure here to guide ships on the river. A royal ordinance of 1722—following the Crown's transfer of the Illinois Country's governance from Canada to Louisiana—may have featured the broadest definition of Louisiana: all land claimed by France south of the Great Lakes between the Rocky Mountains and the Alleghenies. A generation later, trade conflicts between Canada and Louisiana led to a more defined boundary between the French colonies; in 1745, Louisiana governor general Vaudreuil set the northern and eastern bounds of his domain as the Wabash valley up to the mouth of the Vermilion River (near present-day Danville, Illinois); from there, northwest to le Rocher on the Illinois River, and from there west to the mouth of the Rock River (at present day Rock Island, Illinois). Thus, Vincennes and Peoria were the limit of Louisiana's reach; the outposts at Ouiatenon (on the upper Wabash near present-day Lafayette, Indiana), Chicago, Fort Miamis (near present-day Fort Wayne, Indiana), and Prairie du Chien, Wisconsin, operated as dependencies of Canada. The settlement of Natchitoches (along the Red River in present-day northwest Louisiana) was established in 1714 by Louis Juchereau de St. Denis, making it the oldest permanent European settlement in the modern state of Louisiana. The French settlement had two purposes: to establish trade with the Spanish in Texas via the Old San Antonio Road, and to deter Spanish advances into Louisiana. The settlement soon became a flourishing river port and crossroads, giving rise to vast cotton kingdoms along the river that were worked by imported African slaves. Over time, planters developed large plantations and built fine homes in a growing town. This became a pattern repeated in New Orleans and other places, although the commodity crop in the south was primarily sugar cane. Louisiana's French settlements contributed to further exploration and outposts, concentrated along the banks of the Mississippi and its major tributaries, from Louisiana to as far north as the region called the Illinois Country, around present-day St. Louis, Missouri. The latter was settled by French colonists from Illinois. Initially, Mobile and then Biloxi served as the capital of La Louisiane. Recognizing the importance of the Mississippi River to trade and military interests, and wanting to protect the capital from severe coastal storms, France developed New Orleans from 1722 as the seat of civilian and military authority south of the Great Lakes. From then until the United States acquired the territory in the Louisiana Purchase of 1803, France and Spain jockeyed for control of New Orleans and the lands west of the Mississippi. In the 1720s, German immigrants settled along the Mississippi River, in a region referred to as the German Coast. France ceded most of its territory to the east of the Mississippi to Great Britain in 1763, in the aftermath of Britain's victory in the Seven Years' War (generally referred to in North America as the French and Indian War). The rest of Louisiana, including the area around New Orleans and the parishes around Lake Pontchartrain, had become a colony of Spain by the Treaty of Fontainebleau (1762). The transfer of power on either side of the river would be delayed until later in the decade. In 1765, during Spanish rule, several thousand Acadians from the French colony of Acadia (now Nova Scotia, New Brunswick, and Prince Edward Island) made their way to Louisiana after having been expelled from Acadia by the British government after the French and Indian War. They settled chiefly in the southwestern Louisiana region now called Acadiana. The governor Luis de Unzaga y Amézaga, eager to gain more settlers, welcomed the Acadians, who became the ancestors of Louisiana's Cajuns. Spanish Canary Islanders, called Isleños, emigrated from the Canary Islands of Spain to Louisiana under the Spanish crown between 1778 and 1783. In 1800, France's Napoleon Bonaparte reacquired Louisiana from Spain in the Treaty of San Ildefonso, an arrangement kept secret for two years. Expansion of slavery Jean-Baptiste Le Moyne, Sieur de Bienville brought the first two African slaves to Louisiana in 1708, transporting them from a French colony in the West Indies. In 1709, French financier Antoine Crozat obtained a monopoly of commerce in La Louisiane, which extended from the Gulf of Mexico to what is now Illinois. According to historian Hugh Thomas, "that concession allowed him to bring in a cargo of blacks from Africa every year". Physical conditions, including disease, were so harsh there was high mortality among both the colonists and the slaves, resulting in continuing demand and importation of slaves. Starting in 1719, traders began to import slaves in higher numbers; two French ships, the Du Maine and the Aurore, arrived in New Orleans carrying more than 500 black slaves coming from Africa. Previous slaves in Louisiana had been transported from French colonies in the West Indies. By the end of 1721, New Orleans counted 1,256 inhabitants, of whom about half were slaves. In 1724, the French government issued a law called the Code Noir ("Black Code" in English) which "regulate[d] the interaction of whites [blancs] and blacks [noirs] in its colony of Louisiana (which was much larger than the current state of Louisiana). The law consisted of 57 articles, which regulated religion in the colony, outlawed "interracial" marriages (those between people of different skin color, the varying shades of which were also defined by law), restricted manumission, outlined legal punishment of slaves for various offenses, and defined some obligations of owners to their slaves. The main intent of the French government was to assert control over the slave system of agriculture in Louisiana and to impose restrictions on slaveowners there. In practice, the Code Noir was exceedingly difficult to enforce from afar. Some priests continued to perform interracial marriage ceremonies, for example, and some slaveholders continued to manumit slaves without permission while others punished slaves brutally. Article II of the Code Noir of 1724 required owners to provide their slaves with religious education in the state religion, Roman Catholicism. Sunday was to be a day of rest for slaves. On days off, slaves were expected to feed and take care of themselves. During the 1740s economic crisis in the colony, owners had trouble feeding their slaves and themselves. Giving them time off also effectively gave more power to slaves, who started cultivating their own gardens and crafting items for sale as their own property. They began to participate in the economic development of the colony while at the same time increasing independence and self-subsistence. Article VI of the Code Noir forbade mixed marriages, forbade but did little to protect slave women from rape by their owners, overseers or other slaves. On balance, the code benefitted the owners but had more protections and flexibility than did the institution of slavery in the southern Thirteen Colonies. The Louisiana Black Code of 1806 made the cruel punishment of slaves a crime, but owners and overseers were seldom prosecuted for such acts. Fugitive slaves, called maroons, could easily hide in the backcountry of the bayous and survive in small settlements. The word "maroon" comes from the Spanish "cimarron", meaning "fugitive cattle." In the late 18th century, the last Spanish governor of the Louisiana territory wrote: When the United States purchased Louisiana in 1803, it was soon accepted that enslaved Africans could be brought to Louisiana as easily as they were brought to neighboring Mississippi, though it violated U.S. law to do so. Despite demands by United States Rep. James Hillhouse and by the pamphleteer Thomas Paine to enforce existing federal law against slavery in the newly acquired territory, slavery prevailed because it was the source of great profits and the lowest-cost labor. At the start of the 19th century, Louisiana was a small producer of sugar with a relatively small number of slaves, compared to Saint-Domingue and the West Indies. It soon thereafter became a major sugar producer as new settlers arrived to develop plantations. William C. C. Claiborne, Louisiana's first United States governor, said African slave labor was needed because white laborers "cannot be had in this unhealthy climate." Hugh Thomas wrote that Claiborne was unable to enforce the abolition of the Atlantic slave trade, which the U.S. and Great Britain enacted in 1807. The United States continued to protect the domestic slave trade, including the coastwise trade—the transport of slaves by ship along the Atlantic Coast and to New Orleans and other Gulf ports. By 1840, New Orleans had the biggest slave market in the United States, which contributed greatly to the economy of the city and of the state. New Orleans had become one of the wealthiest cities, and the third largest city, in the nation. The ban on the African slave trade and importation of slaves had increased demand in the domestic market. During the decades after the American Revolutionary War, more than one million enslaved African Americans underwent forced migration from the Upper South to the Deep South, two thirds of them in the slave trade. Others were transported by their owners as slaveholders moved west for new lands. With changing agriculture in the Upper South as planters shifted from tobacco to less labor-intensive mixed agriculture, planters had excess laborers. Many sold slaves to traders to take to the Deep South. Slaves were driven by traders overland from the Upper South or transported to New Orleans and other coastal markets by ship in the coastwise slave trade. After sales in New Orleans, steamboats operating on the Mississippi transported slaves upstream to markets or plantation destinations at Natchez and Memphis. Interestingly, for a slave-state, Louisiana harbored escaped Filipino slaves from the Manila Galleons. The members of the Filipino community were then commonly referred to as Manila men, or Manilamen, and later Tagalas, as they were free when they created the oldest settlement of Asians in the United States in the village of Saint Malo, Louisiana, the inhabitants of which, even joined the United States in the War of 1812 against the British Empire while they were being lead by the French-American Jean Lafitte. Haitian migration and influence Spanish occupation of Louisiana lasted from 1769 to 1800. Beginning in the 1790s, waves of immigration took place from Saint-Domingue, following a slave rebellion that started in 1791. Over the next decade, thousands of migrants landed in Louisiana from the island, including ethnic Europeans, free people of color, and African slaves, some of the latter brought in by each free group. They greatly increased the French-speaking population in New Orleans and Louisiana, as well as the number of Africans, and the slaves reinforced African culture in the city. The process of gaining independence in Saint-Domingue was complex, but uprisings continued. In 1803, France pulled out its surviving troops from the island, having suffered the loss of two-thirds sent to the island two years before, mostly to yellow fever. In 1804, Haiti (the second republic in the western hemisphere) proclaimed its independence, achieved by slave leaders. Pierre Clément de Laussat (Governor, 1803) said: "Saint-Domingue was, of all our colonies in the Antilles, the one whose mentality and customs influenced Louisiana the most." Purchase by the United States When the United States won its independence from Great Britain in 1783, one of its major concerns was having a European power on its western boundary, and the need for unrestricted access to the Mississippi River. As American settlers pushed west, they found that the Appalachian Mountains provided a barrier to shipping goods eastward. The easiest way to ship produce was to use a flatboat to float it down the Ohio and Mississippi rivers to the port of New Orleans, where goods could be put on ocean-going vessels. The problem with this route was that the Spanish owned both sides of the Mississippi below Natchez. Napoleon's ambitions in Louisiana involved the creation of a new empire centered on the Caribbean sugar trade. By the terms of the Treaty of Amiens of 1802, Great Britain returned control of the islands of Martinique and Guadeloupe to the French. Napoleon looked upon Louisiana as a depot for these sugar islands, and as a buffer to U.S. settlement. In October 1801 he sent a large military force to take back Saint-Domingue, then under control of Toussaint Louverture after the Haitian revolution. When the army led by Napoleon's brother-in-law Leclerc was defeated, Napoleon decided to sell Louisiana. Thomas Jefferson, third president of the United States, was disturbed by Napoleon's plans to re-establish French colonies in North America. With the possession of New Orleans, Napoleon could close the Mississippi to U.S. commerce at any time. Jefferson authorized Robert R. Livingston, U.S. minister to France, to negotiate for the purchase of the city of New Orleans, portions of the east bank of the Mississippi, and free navigation of the river for U.S. commerce. Livingston was authorized to pay up to $2million. An official transfer of Louisiana to French ownership had not yet taken place, and Napoleon's deal with the Spanish was a poorly kept secret on the frontier. On October 18, 1802, however, Juan Ventura Morales, acting intendant of Louisiana, made public the intention of Spain to revoke the right of deposit at New Orleans for all cargo from the United States. The closure of this vital port to the United States caused anger and consternation. Commerce in the west was virtually blockaded. Historians believe the revocation of the right of deposit was prompted by abuses by the Americans, particularly smuggling, and not by French intrigues as was believed at the time. President Jefferson ignored public pressure for war with France, and appointed James Monroe a special envoy to Napoleon, to assist in obtaining New Orleans for the United States. Jefferson also raised the authorized expenditure to $10million. However, on April 11, 1803, French foreign minister Talleyrand surprised Livingston by asking how much the United States was prepared to pay for the entirety of Louisiana, not just New Orleans and the surrounding area (as Livingston's instructions covered). Monroe agreed with Livingston that Napoleon might withdraw this offer at any time (leaving them with no ability to obtain the desired New Orleans area), and that approval from President Jefferson might take months, so Livingston and Monroe decided to open negotiations immediately. By April 30, they closed a deal for the purchase of the entire Louisiana territory of for sixty million Francs (approximately $15million). Part of this sum, $3.5million, was used to forgive debts owed by France to the United States. The payment was made in United States bonds, which Napoleon sold at face value to the Dutch firm of Hope and Company, and the British banking house of Baring, at a discount of per each $100 unit. As a result, France received only $8,831,250 in cash for Louisiana. English banker Alexander Baring conferred with Marbois in Paris, shuttled to the United States to pick up the bonds, took them to Britain, and returned to France with the money—which Napoleon used to wage war against Baring's own country. When news of the purchase reached the United States, Jefferson was surprised. He had authorized the expenditure of $10million for a port city, and instead received treaties committing the government to spend $15million on a land package which would double the size of the country. Jefferson's political opponents in the Federalist Party argued the Louisiana purchase was a worthless desert, and that the U.S. constitution did not provide for the acquisition of new land or negotiating treaties without the consent of the federal legislature. What really worried the opposition was the new states which would inevitably be carved from the Louisiana territory, strengthening western and southern interests in U.S. Congress, and further reducing the influence of New England Federalists in national affairs. President Jefferson was an enthusiastic supporter of westward expansion, and held firm in his support for the treaty. Despite Federalist objections, the U.S. Senate ratified the Louisiana treaty on October 20, 1803. By statute enacted on October 31, 1803, President Thomas Jefferson was authorized to take possession of the territories ceded by France and provide for initial governance. A transfer ceremony was held in New Orleans on November 29, 1803. Since the Louisiana territory had never officially been turned over to the French, the Spanish took down their flag, and the French raised theirs. The following day, General James Wilkinson accepted possession of New Orleans for the United States. A similar ceremony was held in St. Louis on March 9, 1804, when a French tricolor was raised near the river, replacing the Spanish national flag. The following day, Captain Amos Stoddard of the First U.S. Artillery marched his troops into town and had the American flag run up the fort's flagpole. The Louisiana territory was officially transferred to the United States government, represented by Meriwether Lewis. The Louisiana Territory, purchased for less than three cents an acre, doubled the size of the United States overnight, without a war or the loss of a single American life, and set a precedent for the purchase of territory. It opened the way for the eventual expansion of the United States across the continent to the Pacific Ocean. Shortly after the United States took possession, the area was divided into two territories along the 33rd parallel north on March 26, 1804, thereby organizing the Territory of Orleans to the south and the District of Louisiana (subsequently formed as the Louisiana Territory) to the north. Statehood Louisiana became the eighteenth U.S. state on April 30, 1812; the Territory of Orleans became the State of Louisiana and the Louisiana Territory was simultaneously renamed the Missouri Territory. At its creation, the state of Louisiana did not include the area north and east of the Mississippi River known as the Florida Parishes. On April 14, 1812, Congress had authorized Louisiana to expand its borders to include the Florida Parishes, but the border change required approval of the state legislature, which it did not give until August 4. For the roughly three months in between, the northern border of eastern Louisiana was the course of Bayou Manchac and the middle of Lake Maurepas and Lake Pontchartrain. From 1824 to 1861, Louisiana moved from a political system based on personality and ethnicity to a distinct two-party system, with Democrats competing first against Whigs, then Know Nothings, and finally only other Democrats. Secession and the Civil War According to the 1860 census, 331,726 people were enslaved, nearly 47% of the state's total population of 708,002. The strong economic interest of elite whites in maintaining the slave society contributed to Louisiana's decision to secede from the Union on January 26, 1861. It followed other U.S. states in seceding after the election of Abraham Lincoln as president of the United States. Louisiana's secession was announced on January 26, 1861, and it became part of the Confederate States of America. The state was quickly defeated in the Civil War, a result of Union strategy to cut the Confederacy in two by controlling the Mississippi River. Federal troops captured New Orleans on April 25, 1862. Because a large part of the population had Union sympathies (or compatible commercial interests), the federal government took the unusual step of designating the areas of Louisiana under federal control as a state within the Union, with its own elected representatives to the U.S. Congress. Post–Civil War to mid–20th century Following the American Civil War and emancipation of slaves, violence rose in the southern U.S. as the war was carried on by insurgent private and paramilitary groups. During the initial period afer the war, there was a massive rise in Black participation in terms of voting and holding political office. Louisiana saw the United States' first and second Black governors with Oscar Dunn and P.B.S. Pinchback, both taking the office after serving as Lieutenant Governors (Dunn having been elected to the post of Lieutenant Governor while Pinchback was appointed after being elected as a member of the state Sentate and President Pro Tempore of that body), with 125 Black members of the state legislature being elected during this time, while Charles E. Nash was elected to represent the state's 6 Congressional District in the U.S. House of Representatives. Eventually former Confederates came to dominante the state legislature after the end of Reconstruction and federal occupation in the late 1870s, and black codes were implemented to regulate freedmen and increasinlgy restricted the right to vote. They refused to extend voting rights to African Americans who had been free before the war and had sometimes obtained education and property (as in New Orleans). Following the Memphis riots of 1866 and the New Orleans riot the same year, the Fourteenth Amendment was passed that provided suffrage and full citizenship for freedmen. Congress passed the Reconstruction Act, establishing military districts for those states where conditions were considered the worst, including Louisiana. It was grouped with Texas in what was administered as the Fifth Military District. African Americans began to live as citizens with some measure of equality before the law. Both freedmen and people of color who had been free before the war began to make more advances in education, family stability and jobs. At the same time, there was tremendous social volatility in the aftermath of war, with many whites actively resisting defeat and the free labor market. White insurgents mobilized to enforce white supremacy, first in Ku Klux Klan chapters. By 1877, when federal forces were withdrawn, white Democrats in Louisiana and other states had regained control of state legislatures, often by paramilitary groups such as the White League, which suppressed black voting through intimidation and violence. Following Mississippi's example in 1890, in 1898, the white Democratic, planter-dominated legislature passed a new constitution that effectively disfranchised people of color by raising barriers to voter registration, such as poll taxes, residency requirements and literacy tests. The effect was immediate and long lasting. In 1896, there were 130,334 black voters on the rolls and about the same number of white voters, in proportion to the state population, which was evenly divided. The state population in 1900 was 47% African American: a total of 652,013 citizens. Many in New Orleans were descendants of Creoles of color, the sizeable population of free people of color before the Civil War. By 1900, two years after the new constitution, only 5,320 black voters were registered in the state. Because of disfranchisement, by 1910 there were only 730 black voters (less than 0.5 percent of eligible African-American men), despite advances in education and literacy among blacks and people of color. Blacks were excluded from the political system and also unable to serve on juries. White Democrats had established one-party Democratic rule, which they maintained in the state for decades deep into the 20th century until after congressional passage of the 1965 Voting Rights Act provided federal oversight and enforcement of the constitutional right to vote. In the early decades of the 20th century, thousands of African Americans left Louisiana in the Great Migration north to industrial cities for jobs and education, and to escape Jim Crow society and lynchings. The boll weevil infestation and agricultural problems cost many sharecroppers and farmers their jobs. The mechanization of agriculture also reduced the need for laborers. Beginning in the 1940s, blacks went west to California for jobs in its expanding defense industries. During some of the Great Depression, Louisiana was led by Governor Huey Long. He was elected to office on populist appeal. His public works projects provided thousands of jobs to people in need, and he supported education and increased suffrage for poor whites, but Long was criticized for his allegedly demogogic and autocratic style. He extended patronage control through every branch of Louisiana's state government. Especially controversial were his plans for wealth redistribution in the state. Long's rule ended abruptly when he was assassinated in the state capitol in 1935. Mid–20th century to present Mobilization for World War II created jobs in the state. But thousands of other workers, black and white alike, migrated to California for better jobs in its burgeoning defense industry. Many African Americans left the state in the Second Great Migration, from the 1940s through the 1960s to escape social oppression and seek better jobs. The mechanization of agriculture in the 1930s had sharply cut the need for laborers. They sought skilled jobs in the defense industry in California, better education for their children, and living in communities where they could vote. On November 26, 1958, at Chennault Air Force Base, a USAF B-47 bomber with a nuclear weapon on board developed a fire while on the ground. The aircraft wreckage and the site of the accident were contaminated after a limited explosion of non-nuclear material. In the 1950s the state created new requirements for a citizenship test for voter registration. Despite opposition by the States Rights Party, downstate black voters had begun to increase their rate of registration, which also reflected the growth of their middle classes. In 1960 the state established the Louisiana State Sovereignty Commission, to investigate civil rights activists and maintain segregation. Despite this, gradually black voter registration and turnout increased to 20% and more, and it was 32% by 1964, when the first national civil rights legislation of the era was passed. The percentage of black voters ranged widely in the state during these years, from 93.8% in Evangeline Parish to 1.7% in Tensas Parish, for instance, where there were white efforts to suppress the vote in the black-majority parish. Violent attacks on civil rights activists in two mill towns were catalysts to the founding of the first two chapters of the Deacons for Defense and Justice in late 1964 and early 1965, in Jonesboro and Bogalusa, respectively. Made up of veterans of World War II and the Korean War, they were armed self-defense groups established to protect activists and their families. Continued violent white resistance in Bogalusa to blacks trying to use public facilities in 1965, following passage of the Civil Rights Act of 1964, caused the federal government to order local police to protect the activists. Other chapters were formed in Louisiana, Mississippi, and Alabama. By 1960 the proportion of African Americans in Louisiana had dropped to 32%. The 1,039,207 black citizens were still suppressed by segregation and disfranchisement. African Americans continued to suffer disproportionate discriminatory application of the state's voter registration rules. Because of better opportunities elsewhere, from 1965 to 1970, blacks continued to migrate out of Louisiana, for a net loss of more than 37,000 people. Based on official census figures, the African American population in 1970 stood at 1,085,109, a net gain of more than 46,000 people compared to 1960. During the latter period, some people began to migrate to cities of the New South for opportunities. Since that period, blacks entered the political system and began to be elected to office, as well as having other opportunities. On May 21, 1919, the Nineteenth Amendment to the United States Constitution, giving women full rights to vote, was passed at a national level, and was made the law throughout the United States on August 18, 1920. Louisiana finally ratified the amendment on June 11, 1970. Due to its location on the Gulf Coast, Louisiana has regularly suffered the effects of tropical storms and damaging hurricanes. On August 29, 2005, New Orleans and many other low-lying parts of the state along the Gulf of Mexico were hit by the catastrophic Hurricane Katrina. It caused widespread damage due to breaching of levees and large-scale flooding of more than 80% of the city. Officials had issued warnings to evacuate the city and nearby areas, but tens of thousands of people, mostly African Americans, stayed behind, many of them stranded. Many people died and survivors suffered through the damage of the widespread floodwaters. In July 2016 the shooting of Alton Sterling sparked protests throughout the state capital of Baton Rouge. In August 2016, an unnamed storm dumped trillions of gallons of rain on southern Louisiana, including the cities of Denham Springs, Baton Rouge, Gonzales, St. Amant and Lafayette, causing catastrophic flooding. An estimated 110,000 homes were damaged and thousands of residents were displaced. In 2019, three Louisiana black churches were set on fire. The suspect used gasoline, destroying each church completely. Holden Matthews, 21 years old, was charged with the destruction of the churches. The first case of COVID-19 in Louisiana was announced on March 9, 2020. Since the first confirmed case as of October 27, 2020, there had been 180,069 confirmed cases; 5,854 people have died of COVID-19. Louisiana entered phase one of re-opening the state on May 15. On June 4, Governor John Bel Edwards signed an order moving to phase two. Gov. Edwards extended phase two until September 11, and phase three began with speculation on October 9. Geography Louisiana is bordered to the west by Texas; to the north by Arkansas; to the east by Mississippi; and to the south by the Gulf of Mexico. The state may properly be divided into two parts, the uplands of the north (the region of North Louisiana), and the alluvial along the coast (the Central Louisiana, Acadiana, Florida Parishes, and Greater New Orleans regions). The alluvial region includes low swamp lands, coastal marshlands and beaches, and barrier islands that cover about . This area lies principally along the Gulf of Mexico and the Mississippi River, which traverses the state from north to south for a distance of about and empties into the Gulf of Mexico; also in the state are the Red River; the Ouachita River and its branches; and other minor streams (some of which are called bayous). The breadth of the alluvial region along the Mississippi is 10–60 miles (15–100 km), and along the other rivers, the alluvial region averages about 10 miles (15 km) across. The Mississippi River flows along a ridge formed by its natural deposits (known as a levee), from which the lands decline toward a river beyond at an average fall of six feet per mile (3m/km). The alluvial lands along other streams present similar features. The higher and contiguous hill lands of the north and northwestern part of the state have an area of more than . They consist of prairie and woodlands. The elevations above sea level range from 10 feet (3m) at the coast and swamp lands to 50–60 feet (15–18m) at the prairie and alluvial lands. In the uplands and hills, the elevations rise to Driskill Mountain, the highest point in the state only 535 feet (163m) above sea level. From 1932 to 2010 the state lost 1,800 square miles due to rises in sea level and erosion. The Louisiana Coastal Protection and Restoration Authority (CPRA) spends around $1billion per year to help shore up and protect Louisiana shoreline and land in both federal and state funding. Besides the waterways named, there are the Sabine, forming the western boundary; and the Pearl, the eastern boundary; the Calcasieu, the Mermentau, the Vermilion, Bayou Teche, the Atchafalaya, the Boeuf, Bayou Lafourche, the Courtableau River, Bayou D'Arbonne, the Macon River, the Tensas, Amite River, the Tchefuncte, the Tickfaw, the Natalbany River, and a number of other smaller streams, constituting a natural system of navigable waterways, aggregating over long. The state also has political jurisdiction over the approximately -wide portion of subsea land of the inner continental shelf in the Gulf of Mexico. Through a peculiarity of the political geography of the United States, this is substantially less than the -wide jurisdiction of nearby states Texas and Florida, which, like Louisiana, have extensive Gulf coastlines. The southern coast of Louisiana in the United States is among the fastest-disappearing areas in the world. This has largely resulted from human mismanagement of the coast (see Wetlands of Louisiana). At one time, the land was added to when spring floods from the Mississippi River added sediment and stimulated marsh growth; the land is now shrinking. There are multiple causes. Artificial levees block spring flood water that would bring fresh water and sediment to marshes. Swamps have been extensively logged, leaving canals and ditches that allow salt water to move inland. Canals dug for the oil and gas industry also allow storms to move sea water inland, where it damages swamps and marshes. Rising sea waters have exacerbated the problem. Some researchers estimate that the state is losing a landmass equivalent to 30 football fields every day. There are many proposals to save coastal areas by reducing human damage, including restoring natural floods from the Mississippi. Without such restoration, coastal communities will continue to disappear. And as the communities disappear, more and more people are leaving the region. Since the coastal wetlands support an economically important coastal fishery, the loss of wetlands is adversely affecting this industry. The Gulf of Mexico 'dead zone' off the coast of Louisiana is the largest recurring hypoxic zone in the United States. It was in 2017, the largest ever recorded. Geology The Gulf of Mexico did not exist 250 million years ago when there was but one supercontinent, Pangea. As Pangea split apart, the Atlantic Ocean and Gulf of Mexico opened. Louisiana slowly developed, over millions of years, from water into land, and from north to south. The oldest rocks are exposed in the north, in areas such as the Kisatchie National Forest. The oldest rocks date back to the early Cenozoic Era, some 60 million years ago. The history of the formation of these rocks can be found in D. Spearing's Roadside Geology of Louisiana. The youngest parts of the state were formed during the last 12,000 years as successive deltas of the Mississippi River: the Maringouin, Teche, St. Bernard, Lafourche, the modern Mississippi, and now the Atchafalaya. The sediments were carried from north to south by the Mississippi River. In between the tertiary rocks of the north, and the relatively new sediments along the coast, is a vast belt known as the Pleistocene Terraces. Their age and distribution can be largely related to the rise and fall of sea levels during past ice ages. In general, the northern terraces have had sufficient time for rivers to cut deep channels, while the newer terraces tend to be much flatter. Salt domes are also found in Louisiana. Their origin can be traced back to the early Gulf of Mexico when the shallow ocean had high rates of evaporation. There are several hundred salt domes in the state; one of the most familiar is Avery Island, Louisiana. Salt domes are important not only as a source of salt; they also serve as underground traps for oil and gas. Climate Louisiana has a humid subtropical climate (Köppen climate classification Cfa), with long, hot, humid summers and short, mild winters. The subtropical characteristics of the state are due to its low latitude, low lying topography, and the influence of the Gulf of Mexico, which at its farthest point is no more than away. Rain is frequent throughout the year, although from April to September is slightly wetter than the rest of the year, which is the state's wet season. There is a dip in precipitation in October. In summer, thunderstorms build during the heat of the day and bring intense but brief, tropical downpours. In winter, rainfall is more frontal and less intense. Summers in southern Louisiana have high temperatures from June through September averaging or more, and overnight lows averaging above . At times, temperatures in the 90s°F(), combined with dew points in the upper 70s°F(), create sensible temperatures over . The humid, thick, jungle-like heat in southern Louisiana is a famous subject of countless stories and movies. Temperatures are generally warm in the winter in the southern part of the state, with highs around New Orleans, Baton Rouge, the rest of southern Louisiana, and the Gulf of Mexico averaging . The northern part of the state is mildly cool in the winter, with highs averaging . The overnight lows in the winter average well above freezing throughout the state, with the average near the Gulf and an average low of in the winter in the northern part of the state. On occasion, cold fronts from low-pressure centers to the north, reach Louisiana in winter. Low temperatures near occur on occasion in the northern part of the state but rarely do so in the southern part of the state. Snow is rare near the Gulf of Mexico, although residents in the northern parts of the state might receive a dusting of snow a few times each decade. Louisiana's highest recorded temperature is in Plain Dealing on August 10, 1936, while the coldest recorded temperature is at Minden on February 13, 1899. Louisiana is often affected by tropical cyclones and is very vulnerable to strikes by major hurricanes, particularly the lowlands around and in the New Orleans area. The unique geography of the region, with the many bayous, marshes and inlets, can result in water damage across a wide area from major hurricanes. The area is also prone to frequent thunderstorms, especially in the summer. The entire state averages over 60 days of thunderstorms a year, more than any other state except Florida. Louisiana averages 27 tornadoes annually. The entire state is vulnerable to a tornado strike, with the extreme southern portion of the state slightly less so than the rest of the state. Tornadoes are more common from January to March in the southern part of the state, and from February through March in the northern part of the state. Publicly owned land Owing to its location and geology, the state has high biological diversity. Some vital areas, such as southwestern prairie, have experienced a loss in excess of 98 percent. The pine flatwoods are also at great risk, mostly from fire suppression and urban sprawl. There is not yet a properly organized system of natural areas to represent and protect Louisiana's biological diversity. Such a system would consist of a protected system of core areas linked by biological corridors, such as Florida is planning. Louisiana contains a number of areas which, to varying degrees, prevent people from using them. In addition to National Park Service areas and a United States National Forest, Louisiana operates a system of state parks, state historic sites, one state preservation area, one state forest, and many Wildlife Management Areas. One of Louisiana's largest government-owned areas is Kisatchie National Forest. It is some 600,000 acres in area, more than half of which is flatwoods vegetation, which supports many rare plant and animal species. These include the Louisiana pinesnake and red-cockaded woodpecker. The system of government-owned cypress swamps around Lake Pontchartrain is another large area, with southern wetland species including egrets, alligators, and sturgeon. At least 12 core areas would be needed to build a "protected areas system" for the state; these would range from southwestern prairies, to the Pearl River Floodplain in the east, to the Mississippi River alluvial swamps in the north. Additionally, the state operates a system of 22 state parks, 17 state historic sites and one state preservation area; in these lands, Louisiana maintains a diversity of fauna and flora. National Park Service Historic or scenic areas managed, protected, or otherwise recognized by the National Park Service include: Atchafalaya National Heritage Area in Ascension Parish; Cane River National Heritage Area near Natchitoches; Cane River Creole National Historical Park near Natchitoches; Jean Lafitte National Historical Park and Preserve, headquartered in New Orleans, with units in St. Bernard Parish, Barataria (Crown Point), and Acadiana (Lafayette); Poverty Point National Monument at Delhi, Louisiana; and Saline Bayou, a designated National Wild and Scenic River near Winn Parish in northern Louisiana. U.S. Forest Service Kisatchie National Forest is Louisiana's only national forest. It includes more than 600,000 acres in central and northern Louisiana with large areas of flatwoods and longleaf pine forest. Major cities Louisiana contains 308 incorporated municipalities, consisting of four consolidated city-parishes, and 304 cities, towns, and villages. Louisiana's municipalities cover only 7.9% of the state's land mass but are home to 45.3% of its population. The majority of urban Louisianians live along the coast or in northern Louisiana. The oldest permanent settlement in the state is Nachitoches. Baton Rouge, the state capital, is the second-largest city in the state. The most populous city is New Orleans. As defined by the U.S. Census Bureau, Louisiana contains nine metropolitan statistical areas. Major areas include Greater New Orleans, Greater Baton Rouge, Lafayette, and Shreveport–Bossier City. Demographics Louisiana is the second-most populous of the South Central United States after Texas. The majority of the state's growing population lives in southern Louisiana, spread throughout Greater New Orleans, the Florida Parishes, and Acadiana, while Central and North Louisiana have been losing population. At the 2020 United States census, Louisiana had an apportioned population of 4,661,468. Its resident population was 4,657,757 as of 2020. The United States Census Bureau estimated that the population of Louisiana was 4,648,794 on July 1, 2019, a 2.55% increase since the 2010 United States census. In 2010, the state of Louisiana had a population of 4,533,372, up from 76,556 in 1810. According to immigration statistics in 2018, approximately four percent of Louisianians were immigrants, while another four percent were native-born U.S. citizens with at least one immigrant parent. The majority of Louisianian immigrants came from Mexico (16%), Honduras (15%), Vietnam (10%), the Philippines (5%), and Guatemala (4%). Among the immigrant population in 2014, an estimated 64,500 were undocumented; Louisiana's undocumented immigrant population earned more than a billion U.S. dollars and paid $136million in taxes. The undocumented immigrant population increased to 70,000 in 2016 and comprised two percent of the state population. New Orleans has been defined as a sanctuary city. The population density of the state is 104.9 people per square mile. The center of population of Louisiana is located in Pointe Coupee Parish, in the city of New Roads. According to the 2010 United States census, 5.4% of the population age5 and older spoke Spanish at home, up from 3.5% in 2000; and 4.5% spoke French (including Louisiana French and Louisiana Creole), down from 4.8% in 2000. Race and ethnicity Several American Indian tribes such as the Atakapa and Caddo were the primary residents of Louisiana before European colonization, concentrated along the Red River and Gulf of Mexico. At the beginning of French and Spanish colonization of Louisiana, white and black Americans began to move into the area. From French and Spanish rule in Louisiana, they were joined by Filipinos and Germans, both slave and free, who settled in enclaves within the Greater New Orleans region and Acadiana. By the 19th and 20th centuries, the state's population fluctuated between white and black Americans; 47% of the population was Black or African American in 1900. The Black or African American population declined following migration to states including New York and California in efforts to flee Jim Crow regulations. At the end of the 20th century, Louisiana's population has experienced diversification again, and its non-Hispanic or Latino American white population has been declining. Since 2020, the Black or African American population have made up the largest non-white share of youths. Hispanic and Latino Americans have also increased as the second-largest racial and ethnic composition in the state, making up nearly 7% of Louisiana's population at the 2020 census. As of 2018, the largest single Hispanic and Latino American ethnicity were Mexican Americans (2.0%), followed by Puerto Ricans (0.3%) and Cuban Americans (0.2%). Other Hispanic and Latino Americans altogether made up 2.6% of Louisiana's Hispanic or Latino American population. The Asian American and multiracial communities have also experienced rapid growth, with many of Louisiana's multiracial population identifying as Cajun or Louisiana Creole. At the 2019 American Community Survey, the largest ancestry groups of Louisiana were African American (31.4%), French (9.6%), German (6.2%), English (4.6%), Italian (4.2%), and Scottish (0.9%). African American and French heritage have been dominant since colonial Louisiana. As of 2011, 49.0% of Louisiana's population younger than age1 were minorities. Religion Christians made up 84% of the adult population in 2014, making Louisiana one of the most predominantly-Christian states in the United States; at the 2020 Public Religion Research Institute study, 76.5% of the total adult population were Christian. In 2010, the largest Christian denominations by number of adherents were the Catholic Church with 1,200,900; Southern Baptist Convention with 709,650; and the United Methodist Church with 146,848. Non-denominational Evangelical Protestant churches had 195,903 members. As in other southern U.S. states, the majority of Louisianians, particularly in the north of the state, belong to various Protestant denominations, with Protestants comprising 57% of the state's adult population at the 2014 Pew Research Center study, and 53% at the 2020 Public Religion Research Institute's study. Protestants are concentrated in North Louisiana, Central Louisiana, and the northern tier of the Florida Parishes. According to the 2014 study, Louisiana's largest Protestant Christian denominations were the Southern Baptist Convention, National Baptist Convention USA, National Baptist Convention of America, Progressive National Baptist Convention, American Baptist Churches USA, non/interdenominational Evangelicals and mainline Protestants, the Assemblies of God USA, Church of God in Christ, African Methodist Episcopal and Christian Methodist Episcopal churches, and the United Methodist Church. Because of French and Spanish heritage, and their descendants the Creoles, and later Irish, Italian, Portuguese and German immigrants, southern Louisiana and the Greater New Orleans area are predominantly Catholic; according to the 2020 study, 22% of the population were Catholic. Since Creoles were the first settlers, planters and leaders of the territory, they have traditionally been well represented in politics. For instance, most of the early governors were Creole Catholics. Because Catholics still constitute a significant fraction of Louisiana's population, they have continued to be influential in state politics. The high proportion and influence of the Catholic population makes Louisiana distinct among southern states. The Roman Catholic Archdiocese of New Orleans, Diocese of Baton Rouge, and Diocese of Lafayette in Louisiana are the largest Catholic jurisdictions in the state, located within the Greater New Orleans, Greater Baton Rouge, and Lafayette metropolitan statistical areas. Jewish communities are established in the state's larger cities, notably New Orleans and Baton Rouge. The most significant of these is the Jewish community of the New Orleans area. In 2000, before the 2005 Hurricane Katrina, its population was about 12,000. Louisiana was among the southern states with a significant Jewish population before the 20th century; Virginia, South Carolina, and Georgia also had influential Jewish populations in some of their major cities from the 18th and 19th centuries. The earliest Jewish colonists were Sephardic Jews who immigrated to the Thirteen Colonies. Later in the 19th century, German Jews began to immigrate, followed by those from eastern Europe and the Russian Empire in the late 19th and early 20th centuries. Dominant Jewish movements in the state include Orthodox and Reform Judaism. Prominent Jews in Louisiana's political leadership have included Whig (later Democrat) Judah P. Benjamin (1811–1884), who represented Louisiana in the U.S. Senate before the American Civil War and then became the Confederate secretary of state; Democrat-turned-Republican Michael Hahn who was elected as governor, serving 1864–1865 when Louisiana was occupied by the Union Army, and later elected in 1884 as a U.S. congressman; Democrat Adolph Meyer (1842–1908), Confederate Army officer who represented the state in the U.S. House of Representatives from 1891 until his death in 1908; Republican secretary of state Jay Dardenne (1954–), and Republican (Democrat before 2011) attorney general Buddy Caldwell (1946–). Other non-Christian religions are also primarily established in the metropolitan areas of Louisiana, including Islam, Buddhism and Hinduism. In the Shreveport–Bossier City metropolitan area, Muslims made up an estimated 14% of Louisiana's total Muslim population as of 2014. The largest Islamic denominations in the major metropolises of Louisiana were Sunni Islam, non-denominational Islam and Quranism, Shia Islam, and the Nation of Islam. In the state's irreligious community, 2% affiliated with Atheism and 13% claimed no religion as of 2014; an estimated 10% of the state's population practiced nothing in particular at the 2014 study. Economy Louisiana's population, agricultural products, abundance of oil and natural gas, and southern Louisiana's medical and technology corridors have contributed to its growing and diversifying economy. In 2014, Louisiana was ranked as one of the most small business friendly states, based on a study drawing upon data from more than 12,000 small business owners. The state's principal agricultural products include seafood (it is the biggest producer of crawfish in the world, supplying approximately 90%), cotton, soybeans, cattle, sugarcane, poultry and eggs, dairy products, and rice. Among its energy and other industries, chemical products, petroleum and coal products, processed foods, transportation equipment, and paper products have contributed to a significant portion of the state's GSP. Tourism and gaming are also important elements in the economy, especially in Greater New Orleans. The Port of South Louisiana, located on the Mississippi River between New Orleans and Baton Rouge, was the largest volume shipping port in the Western hemisphere and 4th largest in the world, as well as the largest bulk cargo port in the U.S. in 2004. The Port of South Louisiana continued to be the busiest port by tonnage in the U.S. through 2018. South Louisiana was number 15 among world ports in 2016. New Orleans, Shreveport, and Baton Rouge are home to a thriving film industry. State financial incentives since 2002 and aggressive promotion have given Louisiana the nickname "Hollywood South." Because of its distinctive culture within the United States, only Alaska is Louisiana's rival in popularity as a setting for reality television programs. In late 2007 and early 2008, a film studio was scheduled to open in Tremé, with state-of-the-art production facilities, and a film training institute. Tabasco sauce, which is marketed by one of the United States' biggest producers of hot sauce, the McIlhenny Company, originated on Avery Island. From 2010 to 2020, Louisiana's gross state product increased from $213.6billion to $253.3billion, the 26th highest in the United States at the time. As of 2020, its GSP is greater than the GDPs of Greece, Peru, and New Zealand. Ranking 41st in the United States with a per capita personal income of $30,952 in 2014, its residents per capita income decreased to $28,662 in 2019. The median household income was $51,073, while the national average was $65,712 at the 2019 American Community Survey. In July 2017, the state's unemployment rate was 5.3%; it decreased to 4.4% in 2019. Louisiana has three personal income tax brackets, ranging from 2% to 6%. The state sales tax rate is 4.45%, and parishes can levy additional sales tax on top of this. The state also has a use tax, which includes 4% to be distributed to local governments. Property taxes are assessed and collected at the local level. Louisiana is a subsidized state, and Louisiana taxpayers receive more federal funding per dollar of federal taxes paid compared to the average state. Per dollar of federal tax collected in 2005, Louisiana citizens received approximately $1.78 in the way of federal spending. This ranks the state fourth highest nationally and represents a rise from 1995 when Louisiana received $1.35 per dollar of taxes in federal spending (ranked seventh nationally). Neighboring states and the amount of federal spending received per dollar of federal tax collected were: Texas ($0.94), Arkansas ($1.41), and Mississippi ($2.02). Federal spending in 2005 and subsequent years since has been exceptionally high due to the recovery from Hurricane Katrina. Culture Louisiana is home to many cultures; especially notable are the distinct cultures of the Louisiana Creoles and Cajuns, descendants of French and Spanish settlers in colonial Louisiana. African culture The French colony of La Louisiane struggled for decades to survive. Conditions were harsh, the climate and soil were unsuitable for certain crops the colonists knew, and they suffered from regional tropical diseases. Both colonists and the slaves they imported had high mortality rates. The settlers kept importing slaves, which resulted in a high proportion of native Africans from West Africa, who continued to practice their culture in new surroundings. As described by historian Gwendolyn Midlo Hall, they developed a marked Afro-Creole culture in the colonial era. At the turn of the 18th century and in the early 1800s, New Orleans received a major influx of White and mixed-race refugees fleeing the violence of the Haitian Revolution, many of whom brought their slaves with them. This added another infusion of African culture to the city, as more slaves in Saint-Domingue were from Africa than in the United States. They strongly influenced the African-American culture of the city in terms of dance, music and religious practices. Creole culture Creole culture is an amalgamation of French, African, Spanish (and other European), and Native American cultures. Creole comes from the Portuguese word crioulo; originally it referred to a colonist of European (specifically French) descent who was born in the New World, in comparison to immigrants from France. The oldest Louisiana manuscript to use the word "Creole", from 1782, applied it to a slave born in the French colony. But originally it referred more generally to the French colonists born in Louisiana. Over time, there developed in the French colony a relatively large group of Creoles of color (gens de couleur libres), who were primarily descended from African slave women and French men (later other Europeans became part of the mix, as well as some Native Americans). Often the French would free their concubines and mixed-race children, and pass on social capital to them. They might educate sons in France, for instance, and help them enter the French Army for a career. They also settled capital or property on their mistresses and children. The free people of color gained more rights in the colony and sometimes education; they generally spoke French and were Roman Catholic. Many became artisans and property owners. Over time, the term "Creole" became associated with this class of Creoles of color, many of whom achieved freedom long before the American Civil War. Wealthy French Creoles generally maintained town houses in New Orleans as well as houses on their large sugar plantations outside town along the Mississippi River. New Orleans had the largest population of free people of color in the region; they could find work there and created their own culture, marrying among themselves for decades. Acadian culture The ancestors of Cajuns immigrated mostly from west central France to New France, where they settled in the Atlantic provinces of New Brunswick, Nova Scotia and Prince Edward Island, known originally as the French colony of Acadia. After the British defeated France in the French and Indian War (Seven Years' War) in 1763, France ceded its territory east of the Mississippi River to Britain. After the Acadians refused to swear an oath of loyalty to the British Crown, they were expelled from Acadia, and made their way to places such as France, Britain, and New England. Other Acadians covertly remained in British North America or moved to New Spain. Many Acadians settled in southern Louisiana in the region around Lafayette and the LaFourche Bayou country. They developed a distinct rural culture there, different from the French Creole colonists of New Orleans. Intermarrying with others in the area, they developed what was called Cajun music, cuisine and culture. Isleño culture A third distinct culture in Louisiana is that of the Isleños. Its members are descendants of colonists from the Canary Islands who settled in Spanish Louisiana between 1778 and 1783 and intermarried with other communities such as Frenchman, Acadians, Creoles, Spaniards, and other groups, mainly through the 19th and early 20th centuries. In Louisiana, the Isleños originally settled in four communities which included Galveztown, Valenzuela, Barataria, and San Bernardo. Of those settlements, Valenzuela and San Bernardo were the most successful as the other two were plagued with both disease and flooding. The large migration of Acadian refugees to Bayou Lafourche led to the rapid gallicization of the Valenzuela community while the community of San Bernardo (Saint Bernard) was able to preserve much of its unique culture and language into the 21st century. This being said, the transmission of Spanish and other customs has completely halted in St. Bernard with those having competency in Spanish being octogenarians. Through the centuries, the various Isleño communities of Louisiana have kept alive different elements of their Canary Islander heritage while also adopting and building upon the customs and traditions of the communities that surround them. Today two heritage associates exist for the communities: Los Isleños Heritage and Cultural Society of St. Bernard as well as the Canary Islanders Heritage Society of Louisiana. The Fiesta de los Isleños is celebrated annually in St. Bernard Parish which features heritage performances from local groups and the Canary Islands. Languages According to a 2010 study by the Modern Language Association among persons aged five years and older, 91.26% of Louisiana residents speak only English at home, 3.45% speak French (standard French, French Creole, or Cajun French), 3.30% speak Spanish, and 0.59% speak Vietnamese. Historically, Native American peoples in the area at the time of European encounter were seven tribes distinguished by their languages: Caddo, Tunica, Natchez, Houma, Choctaw, Atakapa, and Chitimacha. Other Native American peoples migrated into the region, escaping from European pressure from the east. Among these were the Alabama, Biloxi, Koasati, and Ofo peoples. Only Koasati still has native speakers in Louisiana (Choctaw, Alabama and possibly Caddo are still spoken in other states), although several tribes are working to revitalize their languages. Starting in the 1700s, French colonists began to settle along the coast and founded New Orleans. They established French culture and language institutions. They imported thousands of slaves from tribes of West Africa, who spoke several different languages. In the creolization process, the slaves developed a Louisiana Creole dialect incorporating both French and African forms, which colonists adopted to communicate with them, and which persisted beyond slavery. In the 20th century, there were still people of mixed race, particularly, who spoke Louisiana Creole French. During the 19th century after the Louisiana Purchase by the United States, English gradually gained prominence for business and government due to the shift in population with settlement by numerous Americans who were English speakers. Many ethnic French families continued to use French in private. Slaves and some free people of color also spoke Louisiana Creole French. The State Constitution of 1812 gave English official status in legal proceedings, but use of French remained widespread. Subsequent state constitutions reflect the diminishing importance of French. The 1868 constitution, passed during the Reconstruction era before Louisiana was re-admitted to the Union, banned laws requiring the publication of legal proceedings in languages other than English. Subsequently, the legal status of French recovered somewhat, but it never regained its pre-Civil War prominence. Several unique dialects of French, Creole, and English are spoken in Louisiana. Dialects of the French language are: Colonial French and Houma French. Louisiana Creole French is the term for one of the Creole languages. Two unique dialects developed of the English language: Louisiana English, a French-influenced variety of English in which dropping of postvocalic /r/ is common; and what is informally known as Yat, which resembles the New York City dialect sometimes with southern influences, particularly that of historical Brooklyn. Both accents were influenced by large communities of immigrant Irish and Italians, but the Yat dialect, which developed in New Orleans, was also influenced by French and Spanish. Colonial French was the dominant language of white settlers in Louisiana during the French colonial period; it was spoken primarily by the French Creoles (native-born). In addition to this dialect, the mixed-race people and slaves developed Louisiana Creole, with a base in West African languages. The limited years of Spanish rule at the end of the 18th century did not result in widespread adoption of the Spanish language. French and Louisiana Creole are still used in modern-day Louisiana, often in family gatherings. English and its associated dialects became predominant after the Louisiana Purchase of 1803, after which the area became dominated by numerous English speakers. In some regions, English was influenced by French, as seen with Louisiana English. Colonial French, although mistakenly named Cajun French by some Cajuns, has persisted alongside English. Renewed interest in the French language in Louisiana has led to the establishment of Canadian-modeled French immersion schools, as well as bilingual signage in the historic French neighborhoods of New Orleans and Lafayette. In addition to private organizations, since 1968 the state has maintained the Council for the Development of French in Louisiana (CODOFIL), which promotes use of the French language in the state's tourism, economic development, culture, education and international relations. In 2018, Louisiana became the first U.S. state to join the Organisation internationale de la Francophonie as an observer. Since Louisiana joined the Francophonie, new organizations have launched to help revitalize Louisiana French and Creole, including the Nous Foundation. Education Louisiana is home to over 40 public and private colleges and universities including Louisiana State University in Baton Rouge, the University of Louisiana at Lafayette in Lafayette, and Tulane University in New Orleans. Louisiana State University is the largest and most comprehensive university in Louisiana; the University of Louisiana at Lafayette is the second largest by enrollment. The University of Louisiana at Lafayette became an R1 university in December 2021. Tulane University is a major private research university and the wealthiest university in Louisiana with an endowment over $1.1billion. Tulane is also highly regarded for its academics nationwide, consistently ranked in the top 50 on U.S. News & World Report's list of best national universities. Louisiana's two oldest and largest HBCUs (historically black colleges and universities) are Southern University in Baton Rouge and Grambling State University in Grambling. Both these Southwestern Athletic Conference (SWAC) schools compete against each other in football annually in the much anticipated Bayou Classic during Thanksgiving weekend in the Superdome. Of note among the education system, the Louisiana Science Education Act was a controversial law passed by the Louisiana Legislature on June 11, 2008 and signed into law by Governor Bobby Jindal on June 25. The act allowed public school teachers to use supplemental materials in the science classroom which are critical of established science on such topics as the theory of evolution and global warming. In 2000, of all of the states, Louisiana had the highest percentage of students in private schools. Danielle Dreilinger of The Times Picayune wrote in 2014 that "Louisiana parents have a national reputation for favoring private schools." The number of students in enrolled in private schools in Louisiana declined by 9% from circa 2000–2005 until 2014, due to the proliferation of charter schools, the 2008 recession and Hurricane Katrina. Ten parishes in the Baton Rouge and New Orleans area had a combined 17% decline in private school enrollment in that period. This prompted private schools to lobby for school vouchers. Louisiana's school voucher program is known as the Louisiana Scholarship Program. It was available in the New Orleans area beginning in 2008 and in the rest of the state beginning in 2012. In 2013, the number of students using school vouchers to attend private schools was 6,751, and for 2014 it was projected to over 8,800. As per a ruling from Ivan Lemelle, a U.S. district judge, the federal government has the right to review the charter school placements to ensure they do not further racial segregation. Transportation The Louisiana Department of Transportation and Development is the state government organization in charge of maintaining public transportation, roadways, bridges, canals, select levees, floodplain management, port facilities, commercial vehicles, and aviation which includes 69 airports. Interstate highways United States highways The Intracoastal Waterway is an important means of transporting commercial goods such as petroleum and petroleum products, agricultural produce, building materials and manufactured goods. In 2018, the state sued the federal government to repair erosion along the waterway. In 2011, Louisiana ranked among the five deadliest states for debris/litter-caused vehicle accidents per total number of registered vehicles and population size. Figures derived from the NHTSA show at least 25 persons in Louisiana were killed per year in motor vehicle collisions with non-fixed objects, including debris, dumped litter, animals and their carcasses. Mass transit Predominantly serving New Orleans, the New Orleans Regional Transit Authority is the largest transit agency in the state. Other transit organizations are St. Bernard Urban Rapid Transit, Jefferson Transit, Capital Area Transit System, Lafayette Transit System, Shreveport Area Transit System, and Monroe Transit, among others. During the 1984 Louisiana World Exposition, there was a gondola system built to go across the Mississippi River, called Mississippi Aerial River Transit, but was closed less than a year later. The Louisiana Transportation Authority (under the Louisiana Department of Transportation and Development), was created in 2001, was created to "promote, plan, finance, develop, construct, control, regulate, operate and maintain any tollway or transitway to be constructed within its jurisdiction. Development, construction, improvement, expansion, and maintenance of an efficient, safe, and well-maintained intermodal transportation system is essential to promote Louisiana's economic growth and the ability of Louisiana's business and industry to compete in regional, national, and global markets and to provide a high quality of life for the people of Louisiana." Law and government In 1849, the state moved the capital from New Orleans to Baton Rouge. Donaldsonville, Opelousas, and Shreveport have briefly served as the seat of Louisiana state government. The Louisiana State Capitol and the Louisiana Governor's Mansion are both located in Baton Rouge. The Louisiana Supreme Court, however, did not move to Baton Rouge but remains headquartered in New Orleans. The current Louisiana governor is Democrat John Bel Edwards. The current United States senators are Republicans John Neely Kennedy and Bill Cassidy. Louisiana has six congressional districts and is represented in the U.S. House of Representatives by five Republicans and one Democrat. Louisiana had eight votes in the Electoral College for the 2020 election. In a 2020 study, Louisiana was ranked as the 24th hardest state for citizens to vote in. Administrative divisions Louisiana is divided into 64 parishes (the equivalent of counties in most other states). List of parishes in Louisiana Louisiana census statistical areas Most parishes have an elected government known as the Police Jury, dating from the colonial days. It is the legislative and executive government of the parish, and is elected by the voters. Its members are called Jurors, and together they elect a president as their chairman. A more limited number of parishes operate under home rule charters, electing various forms of government. This include mayor–council, council–manager (in which the council hires a professional operating manager for the parish), and others. Civil law The Louisiana political and legal structure has maintained several elements from the times of French and Spanish governance. One is the use of the term "parish" (from the French: paroisse) in place of "county" for administrative subdivision. Another is the legal system of civil law based on French, German, and Spanish legal codes and ultimately Roman law, as opposed to English common law. Louisiana's civil law system is what the majority of sovereign states in the world use, especially in Europe and its former colonies, excluding those that derive their legal systems from the British Empire. However, it is incorrect to equate the Louisiana Civil Code with the Napoleonic Code. Although the Napoleonic Code and Louisiana law draw from common legal roots, the Napoleonic Code was never in force in Louisiana, as it was enacted in 1804, after the United States had purchased and annexed Louisiana in 1803. While the Louisiana Civil Code of 1808 has been continuously revised and updated since its enactment, it is still considered the controlling authority in the state. Differences are found between Louisianian civil law and the common law found in the other U.S. states. While some of these differences have been bridged due to the strong influence of common law tradition, the civil law tradition is still deeply rooted in most aspects of Louisiana private law. Thus property, contractual, business entities structure, much of civil procedure, and family law, as well as some aspects of criminal law, are still based mostly on traditional Roman legal thinking. Marriage In 1997, Louisiana became the first state to offer the option of a traditional marriage or a covenant marriage. In a covenant marriage, the couple waives their right to a "no-fault" divorce after six months of separation, which is available in a traditional marriage. To divorce under a covenant marriage, a couple must demonstrate cause. Marriages between ascendants and descendants, and marriages between collaterals within the fourth degree (i.e., siblings, aunt and nephew, uncle and niece, first cousins) are prohibited. Same-sex marriages were prohibited by statute, but the U.S. Supreme Court declared such bans unconstitutional in 2015, in its ruling in Obergefell v. Hodges. Same-sex marriages are now performed statewide. Louisiana is a community property state. Elections From 1898 to 1965, a period when Louisiana had effectively disfranchised most African Americans and many poor whites by provisions of a new constitution, this was essentially a one-party state dominated by white Democrats. Elites had control in the early 20th century, before populist Huey Long came to power as governor. In multiple acts of resistance, blacks left behind the segregation, violence and oppression of the state and moved out to seek better opportunities in northern and western industrial cities during the Great Migrations of 1910–1970, markedly reducing their proportion of population in Louisiana. The franchise for whites was expanded somewhat during these decades, but blacks remained essentially disfranchised until after the civil rights movement of the mid-20th century, gaining enforcement of their constitutional rights through passage by Congress of the Voting Rights Act of 1965. Since the 1960s, when civil rights legislation was passed under President Lyndon Johnson to protect voting and civil rights, most African Americans in the state have affiliated with the Democratic Party. In the same years, many white social conservatives have moved to support Republican Party candidates in national, gubernatorial and statewide elections. In 2004, David Vitter was the first Republican in Louisiana to be popularly elected as a U.S. senator. The previous Republican senator, John S. Harris, who took office in 1868 during Reconstruction, was chosen by the state legislature under the rules of the 19th century. Louisiana is unique among U.S. states in using a system for its state and local elections similar to that of modern France. All candidates, regardless of party affiliation, run in a nonpartisan blanket primary (or "jungle primary") on Election Day. If no candidate has more than 50% of the vote, the two candidates with the highest vote totals compete in a runoff election approximately one month later. This run-off method does not take into account party identification; therefore, it is not uncommon for a Democrat to be in a runoff with a fellow Democrat or a Republican to be in a runoff with a fellow Republican. Congressional races have also been held under the jungle primary system. All other states (except Washington, California, and Maine) use single-party primaries followed by a general election between party candidates, each conducted by either a plurality voting system or runoff voting, to elect senators, representatives, and statewide officials. Between 2008 and 2010, federal congressional elections were run under a closed primary system—limited to registered party members. However, upon the passage of House Bill 292, Louisiana again adopted a nonpartisan blanket primary for its federal congressional elections. Louisiana has six seats in the U.S. House of Representatives, five of which are currently held by Republicans and one by a Democrat. Though the state historically flips between Republican and Democratic governors, Louisiana is not classified as a swing state for presidential elections, as it has regularly supported Republican candidates since the late 20th century. The state's two U.S. senators are Bill Cassidy (R) and John Neely Kennedy (R). Law enforcement Louisiana's statewide police force is the Louisiana State Police. It began in 1922 with the creation of the Highway Commission. In 1927, a second branch, the Bureau of Criminal Investigations, was formed. In 1932, the State Highway Patrol was authorized to carry weapons. On July 28, 1936, the two branches were consolidated to form the Louisiana Department of State Police; its motto was "courtesy, loyalty, service". In 1942, this office was abolished and became a division of the Department of Public Safety, called the Louisiana State Police. In 1988, the Criminal Investigation Bureau was reorganized. Its troopers have statewide jurisdiction with power to enforce all laws of the state, including city and parish ordinances. Each year, they patrol over 12 million miles (20 million km) of roadway and arrest about 10,000 impaired drivers. The State Police are primarily a traffic enforcement agency, with other sections that delve into trucking safety, narcotics enforcement, and gaming oversight. The elected sheriff in each parish is the chief law enforcement officer in the parish. They are the keepers of the local parish prisons, which house felony and misdemeanor prisoners. They are the primary criminal patrol and first responder agency in all matters criminal and civil. They are also the official tax collectors in each parish. The sheriffs are responsible for general law enforcement in their respective parishes. Orleans Parish is an exception, as the general law enforcement duties fall to the New Orleans Police Department. Before 2010, Orleans Parish was the only parish to have two sheriff's offices. Orleans Parish divided sheriffs' duties between criminal and civil, with a different elected sheriff overseeing each aspect. In 2006, a bill was passed which eventually consolidated the two sheriff's departments into one parish sheriff responsible for both civil and criminal matters. In 2015, Louisiana had a higher murder rate (10.3 per 100,000) than any other state in the country for the 27th straight year. Louisiana is the only state with an annual average murder rate (13.6 per 100,000) at least twice as high as the U.S. annual average (6.6 per 100,000) during that period, according to Bureau of Justice Statistics from FBI Uniform Crime Reports. In a different kind of criminal activity, the Chicago Tribune reports that Louisiana is the most corrupt state in the United States. According to The Times Picayune, Louisiana is the prison capital of the world. Many for-profit private prisons and sheriff-owned prisons have been built and operate here. Louisiana's incarceration rate is nearly five times Iran's, 13 times China's and 20 times Germany's. Minorities are incarcerated at rates disproportionate to their share of the state's population. The New Orleans Police Department began a new sanctuary policy to "no longer cooperate with federal immigration enforcement" beginning on February 28, 2016. Judiciary The judiciary of Louisiana is defined under the constitution and law of Louisiana and is composed of the Louisiana Supreme Court, the Louisiana Circuit Courts of Appeal, the district courts, the Justice of the Peace courts, the mayor's courts, the city courts, and the parish courts. The chief justice of the Louisiana Supreme Court is the chief administrator of the judiciary. Its administration is aided by the Judiciary Commission of Louisiana, the Louisiana Attorney Disciplinary Board, and the Judicial Council of the Supreme Court of Louisiana. National Guard Louisiana has more than 9,000 soldiers in the Louisiana Army National Guard, including the 225th Engineer Brigade and the 256th Infantry Brigade. Both these units have served overseas during the War on Terror. The Louisiana Air National Guard has more than 2,000 airmen, and its 159th Fighter Wing has likewise seen combat. Training sites in the state include Camp Beauregard near Pineville, Camp Villere near Slidell, Camp Minden near Minden, England Air Park (formerly England Air Force Base) near Alexandria, Gillis Long Center near Carville, and Jackson Barracks in New Orleans. Sports Louisiana is nominally the least populous state with more than one major professional sports league franchise: the National Basketball Association's New Orleans Pelicans and the National Football League's New Orleans Saints. Louisiana has 12 collegiate NCAA Division I programs, a high number given its population. The state has no NCAA Division II teams and only two NCAA Division III teams. As of 2019, the LSU Tigers football team has won 12 Southeastern Conference titles, six Sugar Bowls and four national championships. Each year New Orleans plays host to the Bayou Classic, and the New Orleans Bowl college football games, while Shreveport hosts the Independence Bowl. Also, New Orleans has hosted the Super Bowl a record eleven times, as well as the BCS National Championship Game, NBA All-Star Game and NCAA Men's Division I Basketball Championship. The Zurich Classic of New Orleans, is a PGA Tour golf tournament held since 1938. The Rock 'n' Roll Mardi Gras Marathon and Crescent City Classic are two road running competitions held at New Orleans. As of 2016, Louisiana was the birthplace of the most NFL players per capita for the eighth year in a row. Notable people Jake Bird, murderer and suspected serial killer Terry Bradshaw, former NFL quarterback and sports personality James Carville, political strategist known for his success with Bill Clinton's presidential campaign Ellen DeGeneres, comedian, television host, actress, writer, and producer Armand Duplantis, pole vaulter. IAAF male World Athlete of the Year 2020 Mannie Fresh; DJ, producer, and rapper Kevin Gates; rapper, singer, songwriter, and entrepreneur DJ Khaled; American DJ, record executive and media personality Angela Kinsey, actress Ali Landry, actress and Miss USA 1996 Jared Leto, actor and musician Huey Long, politician Peyton Manning, former American football quarterback Tim McGraw, singer, actor and record producer Tyler Perry, actor, director, producer, and screenwriter Dustin Poirier; American mixed martial artist, currently signed to the UFC Zachary Richard; Cajun singer, songwriter and poet Fred L. Smith Jr., founder of Competitive Enterprise Institute Ian Somerhalder, actor, model and director Britney Spears; singer, songwriter, dancer and actress Jamie Lynn Spears, singer and actress Lil Wayne; rapper, singer, songwriter, record executive, entrepreneur, and actor Shane West, actor, singer and songwriter Reese Witherspoon, actress YoungBoy Never Broke Again; rapper, singer, and songwriter See also Index of Louisiana-related articles Outline of Louisiana Notes References Bibliography The Sugar Masters: Planters and Slaves in Louisiana's Cane World, 1820–1860 by Richard Follett, Louisiana State University Press, 2007. The Slave Trade: The Story of the Atlantic Slave Trade, 1440–1870 by Hugh Thomas. 1997: Simon and Schuster. p. 548. Inhuman Bondage: The Rise and Fall of Slavery in the New World by David Brion Davis 2006: Oxford University Press. Yiannopoulos, A.N., The Civil Codes of Louisiana (reprinted from Civil Law System: Louisiana and Comparative law, A Coursebook: Texts, Cases and Materials, 3d Edition; similar to version in preface to Louisiana Civil Code, ed. by Yiannopoulos) Rodolfo Batiza, "The Louisiana Civil Code of 1808: Its Actual Sources and Present Relevance", 46 TUL. L. REV. 4 (1971); Rodolfo Batiza, "Sources of the Civil Code of 1808, Facts and Speculation: A Rejoinder", 46 TUL. L. REV. 628 (1972); Robert A. Pascal, Sources of the Digest of 1808: A Reply to Professor Batiza, 46 TUL. L. REV. 603 (1972); Joseph M. Sweeney, Tournament of Scholars Over the Sources of the Civil Code of 1808,46 TUL. L. REV. 585 (1972). The standard history of the state, though only through the Civil War, is Charles Gayarré's History of Louisiana (various editions, culminating in 1866, 4 vols., with a posthumous and further expanded edition in 1885). A number of accounts by 17th- and 18th-century French explorers: Jean-Bernard Bossu, François-Marie Perrin du Lac, Pierre-François-Xavier de Charlevoix, Dumont (as published by Fr. Mascrier), Fr. Louis Hennepin, Lahontan, Louis Narcisse Baudry des Lozières, Jean-Baptiste Bénard de la Harpe, and Laval. In this group, the explorer Antoine Simon Le Page du Pratz may be the first historian of Louisiana with his Histoire de la Louisiane (3 vols., Paris, 1758; 2 vols., London, 1763) François Xavier Martin's History of Louisiana (2 vols., New Orleans, 1827–1829, later ed. by J. F. Condon, continued to 1861, New Orleans, 1882) is the first scholarly treatment of the subject, along with François Barbé-Marbois' Histoire de la Louisiane et de la cession de colonie par la France aux Etats-Unis (Paris, 1829; in English, Philadelphia, 1830). Alcée Fortier's A History of Louisiana (N.Y., 4 vols., 1904) is the most recent of the large-scale scholarly histories of the state. The official works of Albert Phelps and Grace King, the publications of the Louisiana Historical Society and several works on the history of New Orleans (q.v.), among them those by Henry Rightor and John Smith Kendall provide background. External links Louisiana: State Resource Guide, from the Library of Congress Louisiana Geographic Information Center Louisiana Endowment for the Humanities Louisiana Weather and Tides 1812 establishments in the United States Former French colonies Former Spanish colonies Southern United States States and territories established in 1812 States of the Confederate States States of the Gulf Coast of the United States States of the United States Contiguous United States	[ 0.031758036464452744, 0.15921129286289215, -0.18833523988723755, -0.19893109798431396, 0.339172899723053, 0.4277867078781128, 0.27764251828193665, 0.49513232707977295, -0.39520055055618286, -0.48248291015625, -0.31704315543174744, 0.2635519504547119, -0.22958603501319885, 0.703495621681213...
18131	https://en.wikipedia.org/wiki/Los%20Angeles%20International%20Airport	Los Angeles International Airport	Los Angeles International Airport , commonly referred to as LAX (with each of its letters pronounced individually), is the primary international airport serving Los Angeles and its surrounding metropolitan area. LAX is located in the Westchester neighborhood of Los Angeles, southwest of Downtown Los Angeles, with the commercial and residential areas of Westchester to the north, the city of El Segundo to the south and the city of Inglewood to the east. LAX is the closest airport to the Westside and the South Bay. The airport is operated by Los Angeles World Airports (LAWA), a branch of the Los Angeles city government, that also operates Van Nuys Airport for general aviation. The airport covers of land and has four parallel runways. In 2019, LAX handled 88,068,013 passengers, making it the world's third-busiest and the United States' second-busiest airport following Hartsfield–Jackson Atlanta International Airport. As the largest and busiest international airport on the U.S. West Coast, LAX is a major international gateway to the United States, and also serves a connection point for passengers traveling internationally (such as between East Asia and South America). The airport holds the record for the world's busiest origin and destination airport, because relative to other airports, many more travelers begin or end their trips in Los Angeles than use it as a connection. It is also the only airport to rank among the top five U.S. airports for both passenger and cargo traffic. LAX serves as a major hub or focus city for more passenger airlines than any other airport in the United States. Although LAX is the busiest airport in the Greater Los Angeles Area, several other airports, including Hollywood Burbank Airport, John Wayne Airport (Orange County), Long Beach Airport, and Ontario International Airport, serve the region. History In 1926, the Los Angeles City Council and the Chamber of Commerce recognized the need for the city to have its own airport to tap into the fledgling, but quickly growing aviation industry. Several locations were considered, but the final choice was a field in the southern part of Westchester. The location had been promoted by real estate agent William W. Mines, and Mines Field as it was known, had already been selected to host the 1928 National Air Races. On August 13, 1928 the city leased the land and the newly formed Department of Airports began converting the fields once used to grow wheat, barley and lima beans into dirt landing strips. The airport opened on October 1, 1928 and the first structure, Hangar No. 1, was erected in 1929. The building still stands at the airport, remaining in active use and listed on the National Register of Historic Places. Over the next year, the airport started to come together: the dirt runway was replaced with an all-weather surface and more hangars, a restaurant, and a control tower were built. On June 7, 1930, the facility was dedicated and renamed Los Angeles Municipal Airport. The airport was used by private pilots and flying schools, but the city’s vision was that Los Angeles would become the main passenger hub for the area. However, the airport failed to entice any carriers away from the established Burbank Airport or the Grand Central Airport in Glendale. World War II put a pause on any further development of the airport for passenger use. Before the United States entered the war, the aviation manufacturers located around the airport were busy providing aircraft for the allied powers, while the flying schools found themselves in high demand. In January 1942, the military assumed control of the airport, stationing fighter planes at the airfield and building naval gun batteries in the ocean dunes to the west. Meanwhile, airport managers published a master plan for the land, and in early 1943 and convinced voters to back a $12.5 million bond for airport improvements. With a plan and funding in place, the airlines were finally convinced to make the move. After the end of the war, four temporary terminals were quickly erected on the north side of the airport and on December 9, 1946, American Airlines, Trans World Airlines (TWA), United Airlines, Southwest Airways and Western Airlines began passenger operations at the airport, with Pan American Airways (Pan Am) joining the next month. The airport was renamed Los Angeles International Airport in 1949. The temporary terminals would remain in place for 15 years but quickly became inadequate, especially as air travel entered the "jet age" and other cities invested in modern facilities. Airport leaders once again convinced voters to back a $59 million bond on June 5, 1956. The current layout of the passenger facilities was established in 1958 with a plan to build a series of terminals and parking facilities, arranged in the shape of the letter U, in the central portion of the property. The original plan called for the terminal buildings connected at the center of the property by a huge steel-and-glass dome. The dome was never built, but a smaller Theme Building built in the central area became a focal point for people coming to the airport. The first of the new passenger buildings, Terminals 7 and 8, were opened for United Airlines on June 25, 1961, following opening festivities that lasted several days. Terminals 2, 3, 4, 5 and 6 opened later that same year. A major expansion of the airport came in the early 1980s, ahead of the 1984 Summer Olympic Games. In November 1983 a second-level roadway was added, Terminal 1 opened in January 1984 and the Tom Bradley International Terminal opened in June 1984. The original terminals also received expansions and updates in the 1980s. Since 2008, the airport has been undergoing another major expansion. All of the terminals are being refurbished, and the Tom Bradley International Terminal was completely rebuilt, with a West Gates concourse added. Outside of the terminal area, a 4,300 stall parking structure, a Los Angeles Metro Rail station, and a consolidated rental car facility are being built. All will be connected to the terminal area by the LAX Automated People Mover. In the near future, airport managers plan to build two more terminals (0 and 9). All together, these projects are expected to cost of $14 billion and bring LAX's total gates from 146 to 182. The "X" in LAX Before the 1930s, US airports used a two-letter abbreviation and at that time, "LA" served as the designation for Los Angeles Airport. With the rapid growth in the aviation industry, in 1947, the identifiers expanded to three letters and "LA" received an extra letter to become "LAX." The letter "X" does not otherwise have any specific meaning in this identifier. "LAX" is also used for the Port of Los Angeles in San Pedro and by Amtrak for Union Station in downtown Los Angeles. Infrastructure Airfield 24R/06L and 24L/06R (designated the North Airfield Complex) are north of the airport terminals, and 25R/07L and 25L/07R (designated the South Airfield Complex) are south of the airport terminals. LAX is located with the Pacific Ocean to the west and residential communities on all other sides. Since 1972, Los Angeles World Airports has adopted a "Preferential Runway Use Policy" to minimize noise levels in the communities closest to LAX. Typically the loudest operations at an airport are from departing aircraft (as engines operate at full power), so during daytime hours (6:30am to midnight), LAX prefers to operate under the "Westerly Operations" air traffic pattern, named for the prevailing west winds. Under "Westerly Operations", departing aircraft take off to the west (over the ocean), and arriving aircraft approach from the east. To reduce noise to areas north and south of the airport, LAX prefers to use the "inboard" runways (06R/24L and 07L/25R) closest to the central terminal area and further from residential areas for departures, and the "outboard" runways are preferred for arrivals. Historically, over 90% of flights have used the "inboard" departures and "outboard" arrivals scheme. During nighttime hours, when there are fewer aircraft operations and residential areas tend to be more noise sensitive, additional changes are made to reduce noise. Between 10pm and 7am, air traffic controls try to use the "outboard" runways as little as possible and between midnight and 6:30am the air traffic pattern shifts to "Over-Ocean Operations" where departing aircraft continue to take off to the west, but arriving aircraft also approach from the west (over the ocean). There are times when the Over-Ocean and Westerly operations are not possible, particularly when the winds originate from the east, typically during inclement weather and Santa Ana winds events. When that happens, the airport shifts to the non-preferred "Easterly Operations" air traffic pattern where departing aircraft take off to the east, and arriving aircraft approach from the west. The South Airfield Complex tends to see more operations than the North, due to a larger number of passenger gates and air cargo operations. Runways in the North Airfield Complex are separated by . Plans have been advanced and approved to increase the separation by , which would allow a central taxiway between runways, despite opposition from residents living north of LAX. The separation between the two runways in the South Airfield Complex has already increased by to accommodate a central taxiway. Terminals LAX has nine passenger terminals with a total of 146 gates arranged in the shape of the letter U or a horseshoe that are identified by numbers except for the Tom Bradley International Terminal. The Midfield Satellite Concourse, now renamed the West Gates, an expansion for international flights reached through the Tom Bradley Terminal, opened on May 1, 2021. There are of cargo facilities at LAX, as well as a heliport operated by Bravo Aviation. Theme Building The distinctive Theme Building, designed by Pereira & Luckman architect Paul Williams in the Googie style and built in 1961 by Robert E. McKee Construction Co., resembles a flying saucer that has landed on its four legs. A restaurant with a sweeping view of the airport is suspended beneath two arches that form the legs. The Los Angeles City Council designated the building a Los Angeles Historic-Cultural Monument in 1992. A $4 million renovation, with retro-futuristic interior and electric lighting designed by Walt Disney Imagineering, was completed before the Encounter Restaurant opened there in 1997 but is no longer in business. Visitors are able to take the elevator up to the observation deck of the "Theme Building", which had previously been closed after the September 11, 2001 attacks for security reasons. A memorial to the victims of the 9/11 attacks is located on the grounds, as three of the four hijacked planes were originally destined for LAX. The Bob Hope USO expanded and relocated to the first floor of the Theme Building in 2018. Future developments LAWA currently has several plans to modernize LAX, at a cost of $14 billion. These include terminal and runway improvements, which will enhance the passenger experience, reduce overcrowding, and provide airport access to the latest class of very large passenger aircraft; this would bring LAX's total gates from 146 to 182. These improvements include: Reconstruction of Terminals 1 (completed), 2 (completed), 3 (under construction), 4 (under construction), and 6 (under construction) Construction of Terminal 1.5, a connector building between terminals 1 and 2, with a post-security bridge between the terminals and a bus gate to take passengers to boarding gates in the Tom Bradley International Terminal (completed) Reconstruction of Tom Bradley International Terminal (completed) Construction of the West Gates at Tom Bradley International Terminal adding 15 gates (completed) Expansion of the West Gates at Tom Bradley International adding 8 temporary gates (under construction) Construction of the LAX Automated People Mover (APM) (under construction) Construction of the Economy Parking, a 4,300 stall parking structure with passenger pick-up/drop-off areas, connected to the terminal area by the APM (completed) Construction of the Intermodal Transportation Facility – East (ITF-East), a Los Angeles Metro Rail and bus station, connected to the terminal area by the APM (under construction) Construction of a consolidated rental car facility, connected to the terminal area by the APM (under construction) Construction of Concourse 0 east of Terminal 1, adding 9 gates and an additional international arrivals facility (planned) Construction of Terminal 9 east of Sepulveda Boulevard, adding 12 gates and an additional international arrivals facility (planned) Airlines and destinations Passenger Cargo Traffic and statistics It is the world's fourth-busiest airport by passenger traffic and eleventh-busiest by cargo traffic, serving over 87 million passengers and 2 million tons of freight and mail in 2018. It is the busiest airport in the state of California, and the second-busiest airport by passenger boardings in the United States. In terms of international passengers, the second busiest airport for international traffic in the United States, behind only JFK in New York City. The number of aircraft movements (landings and takeoffs) was 700,362 in 2017, the third most of any airport in the world. Top domestic destinations Top international destinations Airline market share Ground transportation and access Transiting between terminals In the secure area of the airport, tunnels or above-ground connectors link terminals 4, 5, 6, 7, 8, and B (Tom Bradley International Terminal). Connectors are currently under construction between terminals 1, 2, 3 and B. LAX Shuttle route A operates in a counter-clockwise loop around the Central Terminal Area, providing frequent service for connecting passengers. However, connecting passengers who use these shuttles must leave and then later re-enter security. LAX Shuttle routes LAX operates several shuttle routes to connect passengers and employees around the airport area: Route A Terminal Connector operates in a counter-clockwise loop around the Central Terminal Area, providing frequent service for connecting passengers. However, connecting passengers who use these shuttles must leave and then later re-enter security. Route C City Bus Center connects the Central Terminal Area and the LAX City Bus Center which is served by transit buses from Beach Cities Transit, Culver CityBus, Los Angeles Metro, Santa Monica Big Blue Bus and Torrance Transit. Buses on this route also serve the Employee South Lot. Route E Economy Parking connects the Central Terminal Area and the Intermodal Transport Facility–West, the airport's economy parking garage. Route M Metro Connector connects the Central Terminal Area and the Aviation/LAX station on the Metro C Line, away. Buses also stop at the "Remote Rental Car Depot," a bus stop served by shuttles to smaller rental car companies. Route X LAX Employee Lots connects the Central Terminal Area and the Employee Parking Lots. The route has three service patterns, the East Lot route only stops at Terminals 1, 2, 3, and B; the West Lot route only stops at Terminals 4, 5, 6, and 7; and the South Lot route stops at all terminals and also stops at the City Bus Center as Route C. Transit buses Most transit buses operate from the LAX City Bus Center, which is located away from the Central Terminal Area, inside Parking Lot C on 96th Street, east of Sepulveda Boulevard. LAX Shuttle route C offers free connections between the LAX City Bus Center/Parking Lot C and the Central Terminal Area. The LAX City Bus Center is served by Beach Cities Transit line 109 to Redondo Beach, Culver CityBus lines 6 and Rapid 6 to Culver City and UCLA, Los Angeles Metro lines 102 to South Gate, 111 to Norwalk, 117 to Downey and 232 to Long Beach, Santa Monica Big Blue Bus lines 3 and Rapid 3 to Santa Monica, and Torrance Transit line 8 to Torrance. During the overnight hours, Los Angeles Metro line 40 offers service to Downtown Los Angeles. The LAX City Bus Center will eventually be replaced by the Intermodal Transport Facility-East, which will be connected to the rest of LAX by the Automated People Mover system. There is also a bus stop at Sepulveda Boulevard and Century Boulevard that is a walk away from Terminals 1 and 7/8 that is served by LADOT Commuter Express line 574 to Sylmar and Encino. This bus stop is also served by some of the same routes as the LAX City Bus Center: Los Angeles Metro lines 40 (overnight only), 117 and 232 and Torrance Transit line 8. FlyAway Bus The FlyAway bus is a nonstop motorcoach/shuttle service run by LAWA, which provides scheduled service between LAX and Union Station in Downtown LA or the FlyAway Terminal at the Van Nuys Airport in the San Fernando Valley. FlyAway buses stop at every LAX terminal in a counter-clockwise direction, starting at terminal 1. The service hours vary based on the line, with most leaving on or near the top of the hour. Buses use the regional system of high-occupancy vehicle lanes and high-occupancy toll lanes (Metro ExpressLanes) to expedite their trips. Metro Rail LAX does not currently have any direct service from the Los Angeles Metro Rail system, however there is a bus connection to a nearby station. LAX Shuttle route G offers free connections between the Central Terminal Area and the Aviation/LAX station on the C Line, away. In 2023, Aviation/Century station on the K Line is expected to open about away from the Central Terminal Area and will the LAX Shuttle will be rerouted. In 2024, Aviation/96th Street station on the K Line is expected to open and will have a direct connection to the LAX Automated People Mover system to the Central Terminal Area. LAX Automated People Mover The LAX Automated People Mover (APM) is an electric train system currently under construction by LAWA. The APM will travel and will have three stations serving the Central Terminal Area (Terminals 1–8 and the Tom Bradley International Terminal). Leaving the Central Terminal Area stations, heading east, the first station will be the Intermodal Transportation Facility–West, a large long-term parking structure, located near employee parking and hotels. The next station will be the Intermodal Transportation Facility–East, which is being built on top of Metro Rail's Aviation/96th Street station and will also have a transit bus terminal. The last stop on the APM will be Consolidated Rent-A-Car facility, which will house of the car rental companies. The APM project is estimated to cost $5.5 billion and be completed in 2023. Freeways and roads LAX's terminals are immediately west of the interchange between Century Boulevard and Sepulveda Boulevard (State Route 1). Interstate 405 can be reached to the east via Century Boulevard. Interstate 105 is to the south via Sepulveda Boulevard, through the Airport Tunnel that crosses under the airport runways. Taxis, ride-share and private shuttles Arriving passengers take a shuttle or walk to the LAXit waiting area east of Terminal 1 for taxi or ride-share pickups. Taxicab services are operated by nine city-authorized taxi companies and regulated by Authorized Taxicab Supervision Inc. (ATS). ATS queues up taxis at the LAXit waiting area. A number of private shuttle companies also offer limousine and bus services to LAX, including from suburban areas such as Lancaster, Palmdale, and Santa Clarita. Bakersfield had a similar service to LAX, but it suspended operations during the 2020 pandemic. Other facilities The airport has the administrative offices of Los Angeles World Airports. Continental Airlines once had its corporate headquarters on the airport property. At a 1962 press conference in the office of Mayor of Los Angeles Sam Yorty, Continental Airlines announced that it planned to move its headquarters to Los Angeles in July 1963. In 1963 Continental Airlines headquarters moved to a two-story, $2.3 million building on the grounds of the airport. The July 2009 Continental Magazine issue stated that the move "underlined Continental Airlines western and Pacific orientation". On July 1, 1983 the airline's headquarters were relocated to the America Tower in the Neartown area of Houston. In addition to Continental Airlines, Western Airlines and Flying Tiger Line also had their headquarters at LAX. Flight Path Learning Center & Museum The Flight Path Learning Center is a museum located at 6661 Imperial Highway and was formerly known as the "West Imperial Terminal". This building used to house some charter flights. It sat empty for 10 years until it was re-opened as a learning center for LAX. The center contains information on the history of aviation, several pictures of the airport, as well as aircraft scale models, flight attendant uniforms, and general airline memorabilia such as playing cards, china, magazines, signs, a TWA gate information sign. The museum's library contains an extensive collection of rare items such as aircraft manufacturer company newsletters/magazines, technical manuals for both military and civilian aircraft, industry magazines dating back to World War II and before, historic photographs and other invaluable references on aircraft operation and manufacturing. The museum has on display "The Spirit of Seventy-Six," a DC-3 that flew in commercial airline service, before serving as a corporate aircraft for Union 76 Oil Company for 32 years. The plane was built in the Douglas Aircraft Company plant in Santa Monica in January 1941, which was a major producer of both commercial and military aircraft. Accidents and incidents During its history there have been numerous incidents, but only the most notable are summarized below: 1930s On January 23, 1939, the sole prototype Douglas 7B twin-engine attack bomber, designed and built as a company project, suffered a loss of the vertical fin and rudder during a demonstration flight over Mines Field, flat spun into the parking lot of North American Aviation, and burned. Another source states that the test pilot, in an attempt to impress the Gallic passenger, attempted a snap roll at low altitude with one engine feathered, resulting in the fatal spin. Douglas test pilot Johnny Cable bailed out at 300 feet, his chute unfurled but did not have time to deploy, he was killed on impact, the flight engineer John Parks rode in the airframe and died, but 33-year-old French Air Force Capt. Paul Chemidlin, riding in the aft fuselage near the top turret, survived with a broken leg, severe back injuries, and a slight concussion. The presence of Chemidlin, a representative of a foreign purchasing mission, caused a furor in Congress by isolationists over neutrality and export laws. The type was developed as the Douglas DB-7. 1940s On June 1, 1940, the first Douglas R3D-1 for the U.S. Navy, BuNo 1901, crashed at Mines Field, before delivery. The Navy later acquired the privately owned DC-5 prototype, from William E. Boeing as a replacement. On November 20, 1940, the prototype NA-73X Mustang, NX19998, first flown October 26, 1940, by test pilot Vance Breese, crashed this date. According to P-51 designer Edgar Schmued, the NA-73 was lost because test pilot Paul Balfour refused, before a high-speed test run, to go through the takeoff and flight test procedure with Schmued while the aircraft was on the ground, claiming "one airplane was like another". After making two high speed passes over Mines Field, he forgot to put the fuel valve on "reserve" and during the third pass ran out of fuel. An emergency landing in a freshly plowed field caused the wheels to dig in, the aircraft flipped over, the airframe was not rebuilt, the second aircraft being used for subsequent testing. On October 26, 1944, WASP pilot Gertrude Tompkins Silver of the 601st Ferrying Squadron, 5th Ferrying Group, Love Field, Dallas, Texas, departed Los Angeles Airport, in a North American P-51D Mustang, 44-15669, at 1600 hrs PWT, headed for the East Coast. She took off into the wind, into an offshore fog bank, and was expected that night at Palm Springs. She never arrived. Owing to a paperwork foul-up, a search did not get under way for several days, and while the eventual search of land and sea was massive, it failed to find a trace of Silver or her plane. She is the only missing WASP pilot. She had married Sgt. Henry Silver one month before her disappearance. 1950s On June 30, 1956, United Airlines Flight 718 collided with TWA Flight 2 over the Grand Canyon, killing 128 people. Both aircraft departed LAX, with fight 718 bound for Chicago Midway, and flight 2 bound for Kansas City. The cause was found to be issues within the US air traffic control system and aviation law. 1960s On January 13, 1969, Scandinavian Airlines System Flight 933 Douglas DC-8-62, crashed into Santa Monica Bay, approximately west of LAX at 7:21 pm, local time. The aircraft was operating as flight SK933, nearing the completion of a flight from Seattle. Of nine crewmembers, three lost their lives to drowning, while 12 of the 36 passengers also drowned. On January 18, 1969, United Airlines Flight 266 a Boeing 727-100 bearing the registration number N7434U, crashed into Santa Monica Bay approximately west of LAX at 6:21 pm local time. The aircraft was destroyed, resulting in the death of all 32 passengers and six crew members aboard. 1970s On the evening of June 6, 1971, Hughes Airwest Flight 706, a Douglas DC-9 jetliner that had departed LAX on a flight to Salt Lake City, Utah, was struck nine minutes after takeoff by a U.S. Marine Corps McDonnell Douglas F-4 Phantom II fighter jet over the San Gabriel Mountains. The midair collision killed all 44 passengers and five crew members aboard the DC-9 airliner and one of two crewmen aboard the military jet. On August 4, 1971, Continental Airlines Flight 712, a Boeing 707, collided in midair with a Cessna 150 over Compton. There were no fatalities. On August 6, 1974, a bomb exploded near the Pan Am ticketing area at Terminal 2; three people were killed and 35 were injured. On March 1, 1978, two tires burst in succession on a McDonnell Douglas DC-10-10 on Continental Airlines Flight 603 during its takeoff roll at LAX and the plane, bound for Honolulu, veered off the runway. A third tire burst and the DC-10's left landing gear collapsed, causing a fuel tank to rupture. Following the aborted takeoff, spilled fuel ignited and enveloped the center portion of the aircraft in flames. During the ensuing emergency evacuation, a husband and wife died when they exited the passenger cabin onto the wing and dropped down directly into the flames. Two additional passengers died of their injuries approximately three months after the accident; 74 others aboard the plane were injured, as were 11 firemen battling the fire. On the evening of March 10, 1979, Swift Aire Flight 235, a twin-engine Aerospatiale Nord 262A-33 turboprop en route to Santa Maria, was forced to ditch in Santa Monica Bay after experiencing engine problems upon takeoff from LAX. The pilot, co-pilot, and a female passenger drowned when they were unable to exit the aircraft after the ditching. The female flight attendant and the three remaining passengers—two men and a pregnant woman—survived and were rescued by several pleasure boats and other watercraft in the vicinity. 1980s On August 31, 1986, Aeroméxico Flight 498, a DC-9 en route from Mexico City, Mexico to Los Angeles, began its descent into LAX when a Piper Cherokee collided with the DC-9's left horizontal stabilizer over Cerritos, causing the DC-9 to crash into a residential neighborhood. All 67 people on the two aircraft were killed, in addition to 15 people on the ground. 5 homes were destroyed and an additional 7 were damaged by the crash and resulting fire. The Piper went down in a nearby schoolyard and caused no further injuries on the ground. As a result of this incident, the FAA required all commercial aircraft to be equipped with Traffic Collision Avoidance System (TCAS). 1990s On February 1, 1991, USAir Flight 1493 (arriving from Columbus, Ohio), a Boeing 737-300, landing on runway 24L at LAX, collided on touchdown with a SkyWest Airlines Fairchild Metroliner, Flight 5569 departing to Palmdale. The Skywest plane was given clearance to wait on the runway for takeoff. The same controller then gave the USAir plane clearance to land on the same runway, forgetting that the SkyWest plane was there. The collision killed all 12 occupants of the SkyWest plane and 23 people aboard the USAir 737. On September 6, 1993, Air New Zealand Flight 55, a Boeing 767-200, suffered a right rear undercarriage failure while boarding for Honolulu. The aircraft was at Gate 104 in the Tom Bradley Terminal. There were 9 crew and 195 passengers onboard. Mud from a runway excursion was slammed for causing the corrosion and stress cracking which caused the failure. 2000s Al-Qaeda attempted to bomb LAX on New Year's Eve 1999/2000. The bomber, Algerian Ahmed Ressam, was captured in Port Angeles, Washington, the U.S. port of entry, with a cache of explosives that could have produced a blast 40 times greater than that of a car bomb hidden in the trunk of the rented car in which he had traveled from Canada. He had planned to leave one or two suitcases filled with explosives in an LAX passenger waiting area. He was initially sentenced to 22 years in prison, but in February 2010 an appellate court ordered that his sentence be extended. On January 31, 2000, Alaska Airlines Flight 261, a McDonnell Douglas MD-83 jetliner flying from Puerto Vallarta, Mexico to San Francisco and Seattle, requested an emergency landing at LAX after experiencing problems with its tail-mounted horizontal stabilizer. Before the plane could divert to Los Angeles, it suddenly plummeted into the Pacific Ocean approximately north of Anacapa Island off the California coast, killing all 88 people aboard. On September 11, 2001, American Airlines Flight 11, United Airlines Flight 175 and American Airlines Flight 77 were bound for LAX and they were hijacked mid-flight. The hijackers flew the aircraft themselves and then crashing the planes into the World Trade Center and The Pentagon. American flags flies over the gates of the three flights at Logan International Airport and Washington Dulles International Airport. In the 2002 Los Angeles International Airport shooting of July 4, 2002, Hesham Mohamed Hadayet killed two Israelis at the ticket counter of El Al Airlines at LAX. Although the gunman was not linked to any terrorist group, the man was upset at U.S. support for Israel, and therefore was motivated by political disagreement. This led the FBI to classify this shooting as a terrorist act, one of the first on U.S. soil since the September 11 attacks. On September 21, 2005, JetBlue Flight 292, an Airbus A320 discovered a problem with its landing gear as it took off from Bob Hope Airport in Burbank. It flew in circles for three hours to burn off fuel, then landed safely at Los Angeles International Airport on runway 25L, balancing on its back wheels as it rolled down the center of the runway. Passengers were able to watch their own coverage live from the satellite broadcast on JetBlue in-flight TV seat displays of their plane as it made an emergency landing with the front landing gear visibly becoming damaged. Because JetBlue did not serve LAX at the time, the aircraft was evaluated and repaired at a Continental Airlines hangar. On July 29, 2006, after America West Express Flight 6008, a Canadair Regional Jet operated by Mesa Airlines from Phoenix, Arizona, landed on runway 25L, controllers instructed the pilot to leave the runway on a taxiway known as "Mike" and stop short of runway 25R. Even though the pilot read back the instructions correctly, he accidentally taxied onto 25R and into the path of a departing SkyWest Airlines Embraer EMB-120 operating United Express Flight 6037 to Monterey. They cleared each other by and nobody was hurt. On August 16, 2007, a runway incursion occurred between WestJet Flight 900 and Northwest Airlines Flight 180 on runways 24R and 24L, respectively, with the aircraft coming within of each other. The planes were carrying a combined total of 296 people, none of whom were injured. The NTSB concluded that the incursion was the result of controller error. In September 2007, FAA Administrator Marion Blakey stressed the need for LAX to increase lateral separation between its pair of north runways in order to preserve the safety and efficiency of the airport. 2010s On October 13 and 14, 2013, two incidents of dry ice bomb explosions occurred at the airport. The first dry ice bomb exploded at 7:00 p.m. in an employee restroom in Terminal 2, with no injuries. Terminal 2 was briefly shut down as a result. On the next day at 8:30 p.m., a dry ice bomb exploded on the ramp area near the Tom Bradley International Terminal, also without injuries. Two other plastic bottles containing dry ice were found at the scene during the second explosion. On October 15, a 28-year-old airport employee was arrested in connection with the explosions and was booked on charges of possession of an explosive or destructive device near an aircraft. On October 18, a 41-year-old airport employee was arrested in connection with the second explosion, and was booked on suspicion of possessing a destructive device near an aircraft. Authorities believe that the incidents were not linked to terrorism. Both men subsequently pleaded no contest and were each sentenced to three years' probation. The airport workers had removed dry ice from a cargo hold into which a dog was to be loaded, because of fears that the dry ice could harm the animal. In the 2013 Los Angeles International Airport shooting of November 1, 2013, at around 9:31 a.m. PDT, a lone gunman entered Terminal 3 and opened fire with a semi-automatic rifle, killing a Transportation Security Administration (TSA) officer and wounding three other people. The gunman was later apprehended and taken into custody. Until the situation was clarified and under control, a few terminals at the airport were evacuated, all inbound flights were diverted and all outbound flights were grounded until the airport began returning to normal operation at around 2:30 p.m. On August 28, 2016, there was a false report of shots fired throughout the airport, causing a temporary lock down and about 3 hours of flight delays. On May 20, 2017, Aeroméxico Flight 642, a Boeing 737-800, collided with a utility truck on a taxiway near Runway 25R, injuring 8 people, two of them seriously. On November 21, 2019, Philippine Airlines Flight 113, operated by a Boeing 777-300ER suffered an engine compressor stall shortly after take off from the airport's Runway 25R, forcing the flight to return. The flight made a successful emergency landing just 13 minutes after departure. There were 342 passengers and 18 crew onboard the flight, with no injuries reported. 2020s On October 28, 2021, more than 300 passengers were forced to flee onto the tarmac after report of a person with a gun at the Terminal 1. Two people were injured, and the flights were temporarily suspended. No weapons were found, but two people were arrested and taken into custody by the airport police. Aircraft spotting The "Imperial Hill" area of El Segundo is a prime location for aircraft spotting, especially for takeoffs. Part of the Imperial Hill area has been set aside as a city park, Clutter's Park. Another popular spotting location sits under the final approach for runways 24 L&R on a lawn next to the Westchester In-N-Out Burger on Sepulveda Boulevard. This is one of the few remaining locations in Southern California from which spotters may watch such a wide variety of low-flying commercial airliners from directly underneath a flight path. One can also do aircraft spotting at a small park in the take-off pattern that (normally) goes out over the Pacific. The park is on the East side of the street Vista Del Mar from where it takes its name, Vista Del Mar Park. Space Shuttle Endeavour At 12:51 p.m. on Friday, September 21, 2012, a Shuttle Carrier Aircraft carrying the Space Shuttle Endeavour landed at LAX on runway 25L. An estimated 10,000 people saw the shuttle land. Interstate 105 was backed up for miles at a standstill. Imperial Highway was shut down for spectators. It was quickly taken off the Shuttle Carrier Aircraft, a modified Boeing 747, and was moved to a United Airlines hangar. The shuttle spent about a month in the hangar while it was prepared to be transported to the California Science Center. In popular culture Numerous films and television shows have been set or filmed partially at LAX, at least partly due to the airport's proximity to Hollywood studios and Los Angeles. Film shoots at the Los Angeles airports, including LAX, produced $590 million for the Los Angeles region from 2002 to 2005. See also California World War II Army Airfields List of airports in the Los Angeles area Metro Los Angeles Airport Police Peirson Mitchell Hall References Further reading Bullock, Freddy. LAX: Los Angeles International Airport (1998) Schoneberger, William A., Ethel Pattison, and Lee Nichols. Los Angeles International Airport (Arcadia Publishing, 2009.) External links Los Angeles International Airport official website LAneXt website LAX Noise Management Internet Flight Tracking System View of LAX runways from inside air traffic control tower, California, 1986. Los Angeles Times Photographic Archive (Collection 1429). UCLA Library Special Collections, Charles E. Young Research Library, University of California, Los Angeles. 1930 establishments in California Airfields of the United States Army Air Forces Air Transport Command in North America Airfields of the United States Army Air Forces in California Airports established in 1930 Airports in Los Angeles County, California Transportation buildings and structures in Los Angeles Westchester, Los Angeles Airports in California	[ -0.10576950013637543, -0.15321539342403412, 0.28225845098495483, 0.20741437375545502, 0.09648428857326508, 0.10640185326337814, 0.024749215692281723, 0.7332050204277039, 0.17783552408218384, -0.7802618145942688, -0.6070489287376404, 0.18214185535907745, -0.6387487649917603, 0.2029696553945...
18133	https://en.wikipedia.org/wiki/La%20T%C3%A8ne%20culture	La Tène culture	The La Tène culture (; ) was a European Iron Age culture. It developed and flourished during the late Iron Age (from about 450 BCE to the Roman conquest in the 1st century BCE), succeeding the early Iron Age Hallstatt culture without any definite cultural break, under considerable Mediterranean influence from the Greeks in pre-Roman Gaul, the Etruscans, and Golasecca culture, but whose artistic style nevertheless did not depend on those Mediterranean influences. La Tène culture's territorial extent corresponded to what is now France, Belgium, Switzerland, Austria, England, Southern Germany, the Czech Republic, parts of Northern Italy, Slovenia and Hungary, as well as adjacent parts of the Netherlands, Slovakia, Serbia, Croatia, Transylvania (western Romania), and Transcarpathia (western Ukraine). The Celtiberians of western Iberia shared many aspects of the culture, though not generally the artistic style. To the north extended the contemporary Pre-Roman Iron Age of Northern Europe, including the Jastorf culture of Northern Germany and all the way to Galatia in Asia Minor (today Turkey). Centered on ancient Gaul, the culture became very widespread, and encompasses a wide variety of local differences. It is often distinguished from earlier and neighbouring cultures mainly by the La Tène style of Celtic art, characterized by curving "swirly" decoration, especially of metalwork. It is named after the type site of La Tène on the north side of Lake Neuchâtel in Switzerland, where thousands of objects had been deposited in the lake, as was discovered after the water level dropped in 1857. La Tène is the type site and the term archaeologists use for the later period of the culture and art of the ancient Celts, a term that is firmly entrenched in the popular understanding, but presents numerous problems for historians and archaeologists. Periodization Extensive contacts through trade are recognized in foreign objects deposited in elite burials; stylistic influences on La Tène material culture can be recognized in Etruscan, Italic, Greek, Dacian and Scythian sources. Date-able Greek pottery and analysis employing scientific techniques such as dendrochronology and thermoluminescence help provide date ranges for an absolute chronology at some La Tène sites. La Tène history was originally divided into "early", "middle" and "late" stages based on the typology of the metal finds (Otto Tischler 1885), with the Roman occupation greatly disrupting the culture, although many elements remain in Gallo-Roman and Romano-British culture. A broad cultural unity was not paralleled by overarching social-political unifying structures, and the extent to which the material culture can be linguistically linked is debated. The art history of La Tène culture has various schemes of periodization. The archaeological period is now mostly divided into four sub-periods, following Paul Reinecke. History The preceding final phase of the Hallstatt culture, HaD, c. 650–450 BC, was also widespread across Central Europe, and the transition over this area was gradual, being mainly detected through La Tène style elite artefacts, which first appear on the western edge of the old Hallstatt region.Though there is no agreement on the precise region in which La Tène culture first developed, there is a broad consensus that the centre of the culture lay on the northwest edges of Hallstatt culture, north of the Alps, within the region between in the West the valleys of the Marne and Moselle, and the part of the Rhineland nearby. In the east the western end of the old Hallstatt core area in modern Bavaria, Czechia, Austria and Switzerland formed a somewhat separate "eastern style Province" in the early La Tène, joining with the western area in Alsace. In 1994 a prototypical ensemble of elite grave sites of the early 5th century BCE was excavated at Glauberg in Hesse, northeast of Frankfurt-am-Main, in a region that had formerly been considered peripheral to the La Tène sphere. The site at La Tène itself was therefore near the southern edge of the original "core" area (as is also the case for the Hallstatt site for its core). The establishment of a Greek colony, soon very successful, at Massalia (modern Marseilles) on the Mediterranean coast of France led to great trade with the Hallstatt areas up the Rhone and Saone river systems, and early La Tène elite burials like the Vix Grave in Burgundy contain imported luxury goods along with artifacts produced locally. Most areas were probably controlled by tribal chiefs living in hilltop forts, while the bulk of the population lived in small villages or farmsteads in the countryside. By 500 BCE the Etruscans expanded to border Celts in north Italy, and trade across the Alps began to overhaul trade with the Greeks, and the Rhone route declined. Booming areas included the middle Rhine, with large iron ore deposits, the Marne and Champagne regions, and also Bohemia, although here trade with the Mediterranean area was much less important. Trading connections and wealth no doubt played a part in the origin of the La Tène style, though how large a part remains much discussed; specific Mediterranean-derived motifs are evident, but the new style does not depend on them. Barry Cunliffe notes localization of La Tène culture during the 5th century BCE when there arose "two zones of power and innovation: a Marne – Moselle zone in the west with trading links to the Po Valley via the central Alpine passes and the Golasecca culture, and a Bohemian zone in the east with separate links to the Adriatic via the eastern Alpine routes and the Venetic culture". From their homeland, La Tène culture expanded in the 4th century BCE to more of modern France, Germany, and Central Europe, and beyond to Hispania, northern and central Italy, the Balkans, and even as far as Asia Minor, in the course of several major migrations. La Tène style artefacts start to appear in Britain around the same time, and Ireland rather later. The style of "Insular La Tène" art is somewhat different and the artefacts are initially found in some parts of the islands but not others. Migratory movements seem at best only partly responsible for the diffusion of La Tène culture there, and perhaps other parts of Europe. By about 400 BCE, the evidence for Mediterranean trade becomes sparse; this may be because the expanding Celtic populations began to migrate south and west, coming into violent conflict with the established populations, including the Etruscans and Romans. The settled life in much of the La Tène homelands also seems to have become much more unstable and prone to wars. In about 387 BCE, the Celts under Brennus defeated the Romans and then sacked Rome, establishing themselves as the most prominent threats to the Roman homeland, a status they would retain through a series of Roman-Gallic wars until Julius Caesar's final conquest of Gaul in 58-50 BCE. The Romans prevented the Celts from reaching very far south of Rome, but on the other side of the Adriatic Sea groups passed through the Balkans to reach Greece, where Delphi was attacked in 279 BCE, and Asia, where Galatia was established as a Celtic area of Anatolia. By this time, the La Tène style was spreading to the British Isles, though apparently without any significant movements in population. After about 275 BCE, Roman expansion into the La Tène area began, at first with the conquest of Gallia Cisalpina. The conquest of Celtic Gaul began in 121 BCE and was complete with the Gallic Wars of the 50s BCE. Gaulish culture now quickly assimilated to Roman culture, giving rise to the hybrid Gallo-Roman culture of Late Antiquity. Material culture La Tène metalwork in bronze, iron and gold, developing technologically out of Hallstatt culture, is stylistically characterized by inscribed and inlaid intricate spirals and interlace, on fine bronze vessels, helmets and shields, horse trappings and elite jewelry, especially the neck rings called torcs and elaborate clasps called fibulae. It is characterized by elegant, stylized curvilinear animal and vegetal forms, allied with the Hallstatt traditions of geometric patterning. The Early Style of La Tène art and culture mainly featured static, geometric decoration, while the transition to the Developed Style constituted a shift to movement-based forms, such as triskeles. Some subsets within the Developed Style contain more specific design trends, such as the recurrent serpentine scroll of the Waldalgesheim Style. Initially La Tène people lived in open settlements that were dominated by the chieftains' hill forts. The development of towns—oppida—appears in mid-La Tène culture. La Tène dwellings were carpenter-built rather than of masonry. La Tène peoples also dug ritual shafts, in which votive offerings and even human sacrifices were cast. Severed heads appear to have held great power and were often represented in carvings. Burial sites included weapons, carts, and both elite and household goods, evoking a strong continuity with an afterlife. Elaborate burials also reveal a wide network of trade. In Vix, France, an elite woman of the 6th century BCE was buried with a very large bronze "wine-mixer" made in Greece. Exports from La Tène cultural areas to the Mediterranean cultures were based on salt, tin, copper, amber, wool, leather, furs and gold. Artefacts typical of the La Tène culture were also discovered in stray finds as far afield as Scandinavia, Northern Germany, Poland and in the Balkans. It is therefore common to also talk of the "La Tène period" in the context of those regions even though they were never part of the La Tène culture proper, but connected to its core area via trade. Ethnology The bearers of the La Tène culture were the people known as Celts or Gauls to ancient ethnographers. Ancient Celtic culture had no written literature of its own, but rare examples of epigraphy in the Greek or Latin alphabets exist allowing the fragmentary reconstruction of Continental Celtic. Current knowledge of this cultural area is derived from three sources comprising archaeological evidence, Greek and Latin literary records, and ethnographical evidence suggesting some La Tène artistic and cultural survivals in traditionally Celtic regions of far western Europe. Some of the societies that are archaeologically identified with La Tène material culture were identified by Greek and Roman authors from the 5th century onwards as Keltoi ("Celts") and Galli ("Gauls"). Herodotus (iv.49) correctly placed Keltoi at the source of the Ister/Danube, in the heartland of La Tène material culture: "The Ister flows right across Europe, rising in the country of the Celts". Whether the usage of classical sources means that the whole of La Tène culture can be attributed to a unified Celtic people is difficult to assess; archaeologists have repeatedly concluded that language, material culture, and political affiliation do not necessarily run parallel. Frey (2004) notes that in the 5th century, "burial customs in the Celtic world were not uniform; rather, localised groups had their own beliefs, which, in consequence, also gave rise to distinct artistic expressions". Type site The La Tène type site is on the northern shore of Lake Neuchâtel, Switzerland, where the small river Thielle, connecting to another lake, enters the Lake Neuchâtel. In 1857, prolonged drought lowered the waters of the lake by about 2 m. On the northernmost tip of the lake, between the river and a point south of the village of Epagnier (), Hansli Kopp, looking for antiquities for Colonel Frédéric Schwab, discovered several rows of wooden piles that still reached up about 50 cm into the water. From among these, Kopp collected about forty iron swords. The Swiss archaeologist Ferdinand Keller published his findings in 1868 in his influential first report on the Swiss pile dwellings (Pfahlbaubericht). In 1863 he interpreted the remains as a Celtic village built on piles. Eduard Desor, a geologist from Neuchâtel, started excavations on the lakeshore soon afterwards. He interpreted the site as an armory, erected on platforms on piles over the lake and later destroyed by enemy action. Another interpretation accounting for the presence of cast iron swords that had not been sharpened, was of a site for ritual depositions. With the first systematic lowering of the Swiss lakes from 1868 to 1883, the site fell completely dry. In 1880, Emile Vouga, a teacher from Marin-Epagnier, uncovered the wooden remains of two bridges (designated "Pont Desor" and "Pont Vouga") originally over 100 m long, that crossed the little Thielle River (today a nature reserve) and the remains of five houses on the shore. After Vouga had finished, F. Borel, curator of the Marin museum, began to excavate as well. In 1885 the canton asked the Société d'Histoire of Neuchâtel to continue the excavations, the results of which were published by Vouga in the same year. All in all, over 2500 objects, mainly made from metal, have been excavated in La Tène. Weapons predominate, there being 166 swords (most without traces of wear), 270 lanceheads, and 22 shield bosses, along with 385 brooches, tools, and parts of chariots. Numerous human and animal bones were found as well. The site was used from the 3rd century, with a peak of activity around 200 BCE and abandonment by about 60 BCE. Interpretations of the site vary. Some scholars believe the bridge was destroyed by high water, while others see it as a place of sacrifice after a successful battle (there are almost no female ornaments). An exhibition marking the 150th anniversary of the discovery of the La Tène site opened in 2007 at the Musée Schwab in Biel/Bienne, Switzerland, moving to move to Zürich in 2008 and Mont Beuvray in Burgundy in 2009. Genetics A genetic study published in PLOS One in December 2018 examined 45 individuals buried at a La Téne necropolis in Urville-Nacqueville, France. The people buried there were identified as Gauls. The mtDNA of the examined individuals belonged primarily to haplotypes of H and U. They were found to be carrying a large amount of steppe ancestry, and to have been closely related to peoples of the preceding Bell Beaker culture, suggesting genetic continuity between Bronze Age and Iron Age France. Significant gene flow with Great Britain and Iberia was detected. The results of the study partially supported the notion that French people are largely descended from the Gauls. A genetic study published in the Journal of Archaeological Science in October 2019 examined 43 maternal and 17 paternal lineages for the La Téne necropolis in Urville-Nacqueville, France, and 27 maternal and 19 paternal lineages for La Téne tumulus of Gurgy Les Noisats near modern Paris, France. The examined individuals displayed strong genetic resemblance to peoples of the earlier Yamnaya culture, Corded Ware culture and Bell Beaker culture. They carried a diverse set of maternal lineages associated with steppe ancestry. The paternal lineages were on the other hand characterized by a "striking homogeneity", belonging entirely to haplogroup R and R1b, both of whom are associated with steppe ancestry. The evidence suggested that the Gauls of the La Téne culture were patrilineal and patrilocal, which is in agreement with archaeological and literary evidence. A genetic study published in the Proceedings of the National Academy of Sciences of the United States of America in June 2020 examined the remains of 25 individuals ascribed to the La Tène culture. The nine examples of individual Y-DNA extracted were determined to belong to either the paragroups or subclades of haplogroups R1b1a1a2 (R-M269; three examples), R1b1a1a2a1a2c1a1a1a1a1 (R-M222), R1b1 (R-L278), R1b1a1a (R-P297), I1 (I-M253), E1b1b (E-M215), or other, unspecified, subclades of haplogroup R. The 25 samples of mtDNA extracted was determined to belong to various subclades of haplogroup H, HV, U, K, J, V and W. The examined individuals of the Hallstatt culture and La Tène culture were genetically highly homogenous and displayed continuity with the earlier Bell Beaker culture. They carried about 50% steppe-related ancestry. Sites Some sites are: Artifacts See :Category:Celtic art. Some outstanding La Tène artifacts are: Vix Grave of a very wealthy woman in Burgundy buried with an 1100-litre (290 gallon) bronze krater, the largest ever found. Mšecké Žehrovice Head, a stone head from the modern Czech Republic A life-sized sculpture of a warrior that stood above the Glauberg burials Chariot burial found at La Gorge Meillet (St-Germain-en-Laye: Musée des Antiquités Nationales) Basse Yutz Flagons 5th century Agris Helmet, with gold covering, c. 350 Waldalgesheim chariot burial, Bad Kreuznach, Germany, late 4th century BCE, Rheinisches Landesmuseum Bonn; the "Waldalgesheim phase/style" of the art takes its name from the jewellery found here. A gold-and-bronze model of an oak tree (3rd century BCE) found at the Oppidum of Manching. Sculptures from Roquepertuse, a sanctuary in the south of France The silver Gundestrup cauldron (2nd or 1st century BCE), found ritually broken in a peat bog near Gundestrup, Denmark, but probably made near the Black Sea, perhaps in Thrace. (National Museum of Denmark, Copenhagen) Battersea Shield (350–50 BCE), found in the Thames, made of bronze with red enamel. (British Museum, London) Waterloo Helmet, 150-50 BCE, found in London in the Thames "Witham Shield" (4th century BCE). (British Museum, London) Torrs Pony-cap and Horns, from Scotland Cordoba Treasure Turoe stone in Galway and Killycluggin Stone in Cavan Ireland Great Torc from Snettisham, 100-75 BCE, gold, the most elaborate of the British style of torcs Meyrick Helmet, post-conquest Roman helmet shape, with La Tène decoration Noric steel Notes References Garrow, Duncan (ed), Rethinking Celtic Art, 2008, Oxbow Books, , 9781842173183, google books Green, Miranda, Celtic Art, Reading the Messages, 1996, The Everyman Art Library, Laing, Lloyd and Jenifer. Art of the Celts, Thames and Hudson, London 1992 McIntosh, Jane, Handbook to Life in Prehistoric Europe, 2009, Oxford University Press (USA), Megaw, Ruth and Vincent (2001). Celtic Art. Further reading Cunliffe, Barry. The Ancient Celts. Oxford: Oxford University Press. 1997 Collis, John. The Celts: Origins, Myths, Invention. London: Tempus, 2003. Kruta, Venceslas, La grande storia dei Celti. La nascita, l'affermazione, la decadenza, Newton & Compton, Roma, 2003 (492 pp. - a translation of Les Celtes, histoire et dictionnaire. Des origines à la romanisation et au christianisme, Robert Laffont, Paris, 2000, without the dictionary) James, Simon. The Atlantic Celts. London: British Museum Press, 1999. James, Simon & Rigby, Valery. Britain and the Celtic Iron Age. London: British Museum Press, 1997. Reginelli Servais Gianna and Béat Arnold, La Tène, un site, un mythe, Hauterive : Laténium - Parc et musée d'archéologie de Neuchâtel, 2007, Cahiers d'archéologie romande de la Bibliothèque historique vaudoise, 3 vols, External links Charles Bergengren, Cleveland Institute of Art, 1999: illustrations of La Tène artifacts La Tène Archaeological Sites in Romania Celtic archaeological cultures Iron Age cultures of Europe Archaeological cultures of Central Europe Archaeological cultures of Southeastern Europe Archaeological cultures of Southern Europe Archaeological cultures of Southwestern Europe Archaeological cultures of Western Europe Archaeological cultures in Austria Archaeological cultures in Belgium Archaeological cultures in Bulgaria Archaeological cultures in Croatia Archaeological cultures in the Czech Republic Archaeological cultures in England Archaeological cultures in France Archaeological cultures in Germany Archaeological cultures in Hungary Archaeological cultures in Ireland Archaeological cultures in the Netherlands Archaeological cultures in Portugal Archaeological cultures in Romania Archaeological cultures in Scotland Archaeological cultures in Serbia Archaeological cultures in Slovakia Archaeological cultures in Slovenia Archaeological cultures in Spain Archaeological cultures in Switzerland Archaeological cultures in Turkey	[ 0.06559675931930542, 0.1055818572640419, -0.9946136474609375, -0.06438573449850082, -0.13184301555156708, 0.8831610083580017, 0.37569659948349, 1.0771749019622803, -0.48739519715309143, -0.8815836906433105, -0.26044678688049316, 0.19336649775505066, 0.0739424079656601, 0.6245935559272766, ...
18135	https://en.wikipedia.org/wiki/Lorenz%20curve	Lorenz curve	In economics, the Lorenz curve is a graphical representation of the distribution of income or of wealth. It was developed by Max O. Lorenz in 1905 for representing inequality of the wealth distribution. The curve is a graph showing the proportion of overall income or wealth assumed by the bottom x% of the people, although this is not rigorously true for a finite population (see below). It is often used to represent income distribution, where it shows for the bottom x% of households, what percentage (y%) of the total income they have. The percentage of households is plotted on the x-axis, the percentage of income on the y-axis. It can also be used to show distribution of assets. In such use, many economists consider it to be a measure of social inequality. The concept is useful in describing inequality among the size of individuals in ecology and in studies of biodiversity, where the cumulative proportion of species is plotted against the cumulative proportion of individuals. It is also useful in business modeling: e.g., in consumer finance, to measure the actual percentage y% of delinquencies attributable to the x% of people with worst risk scores. Explanation Data from 2005. Points on the Lorenz curve represent statements such as, "the bottom 20% of all households have 10% of the total income." A perfectly equal income distribution would be one in which every person has the same income. In this case, the bottom N% of society would always have N% of the income. This can be depicted by the straight line y = x; called the "line of perfect equality." By contrast, a perfectly unequal distribution would be one in which one person has all the income and everyone else has none. In that case, the curve would be at y = 0% for all x < 100%, and y = 100% when x = 100%. This curve is called the "line of perfect inequality." The Gini coefficient is the ratio of the area between the line of perfect equality and the observed Lorenz curve to the area between the line of perfect equality and the line of perfect inequality. The higher the coefficient, the more unequal the distribution is. In the diagram on the right, this is given by the ratio A/(A+B), where A and B are the areas of regions as marked in the diagram. Definition and calculation The Lorenz curve is a probability plot (a P–P plot) comparing the distribution of a variable against a hypothetical uniform distribution of that variable. It can usually be represented by a function L(F), where F, the cumulative portion of the population, is represented by the horizontal axis, and L, the cumulative portion of the total wealth or income, is represented by the vertical axis. For a discrete distribution of Y given by values y1,...,yn in non-decreasing order ( yi ≤ yi+1) and their probabilities the Lorenz curve is the continuous piecewise linear function connecting the points ( Fi, Li ), i = 0 to n, where F0 = 0, L0 = 0, and for i = 1 to n: When all yi are equally probable with probabilities 1/n this simplifies to For a continuous distribution with the probability density function f and the cumulative distribution function F, the Lorenz curve L is given by: where denotes the average. The Lorenz curve L(F) may then be plotted as a function parametric in x: L(x) vs. F(x). In other contexts, the quantity computed here is known as the length biased (or size biased) distribution; it also has an important role in renewal theory. Alternatively, for a cumulative distribution function F(x) with inverse x(F), the Lorenz curve L(F) is directly given by: The inverse x(F) may not exist because the cumulative distribution function has intervals of constant values. However, the previous formula can still apply by generalizing the definition of x(F): x(F1) = inf {y : F(y) ≥ F1} For an example of a Lorenz curve, see Pareto distribution. Properties A Lorenz curve always starts at (0,0) and ends at (1,1). The Lorenz curve is not defined if the mean of the probability distribution is zero or infinite. The Lorenz curve for a probability distribution is a continuous function. However, Lorenz curves representing discontinuous functions can be constructed as the limit of Lorenz curves of probability distributions, the line of perfect inequality being an example. The information in a Lorenz curve may be summarized by the Gini coefficient and the Lorenz asymmetry coefficient. The Lorenz curve cannot rise above the line of perfect equality. A Lorenz curve that never falls beneath a second Lorenz curve and at least once runs above it, has Lorenz dominance over the second one. If the variable being measured cannot take negative values, the Lorenz curve: cannot sink below the line of perfect inequality, is increasing. Note however that a Lorenz curve for net worth would start out by going negative due to the fact that some people have a negative net worth because of debt. The Lorenz curve is invariant under positive scaling. If X is a random variable, for any positive number c the random variable c X has the same Lorenz curve as X. The Lorenz curve is flipped twice, once about F = 0.5 and once about L = 0.5, by negation. If X is a random variable with Lorenz curve LX(F), then −X has the Lorenz curve: L − X = 1 − L X (1 − F) The Lorenz curve is changed by translations so that the equality gap F − L(F) changes in proportion to the ratio of the original and translated means. If X is a random variable with a Lorenz curve L X (F) and mean μ X , then for any constant c ≠ −μ X , X + c has a Lorenz curve defined by: For a cumulative distribution function F(x) with mean μ and (generalized) inverse x(F), then for any F with 0 < F < 1 : If the Lorenz curve is differentiable: If the Lorenz curve is twice differentiable, then the probability density function f(x) exists at that point and: If L(F) is continuously differentiable, then the tangent of L(F) is parallel to the line of perfect equality at the point F(μ). This is also the point at which the equality gap F − L(F), the vertical distance between the Lorenz curve and the line of perfect equality, is greatest. The size of the gap is equal to half of the relative mean absolute deviation: See also Distribution (economics) Distribution of wealth Welfare economics Income inequality metrics Gini coefficient Hoover index (a.k.a. Robin Hood index) ROC analysis Social welfare (political science) Economic inequality Zipf's law Pareto distribution Mean deviation References Further reading External links WIID: World Income Inequality Database, a source of information on inequality, collected by WIDER (World Institute for Development Economics Research, part of United Nations University) glcurve: Stata module to plot Lorenz curve (type "findit glcurve" or "ssc install glcurve" in Stata prompt to install) Free add-on to STATA to compute inequality and poverty measures Free Online Software (Calculator) computes the Gini Coefficient, plots the Lorenz curve, and computes many other measures of concentration for any dataset Free Calculator: Online and downloadable scripts (Python and Lua) for Atkinson, Gini, and Hoover inequalities Users of the R data analysis software can install the "ineq" package which allows for computation of a variety of inequality indices including Gini, Atkinson, Theil. A MATLAB Inequality Package, including code for computing Gini, Atkinson, Theil indexes and for plotting the Lorenz Curve. Many examples are available. A complete handout about the Lorenz curve including various applications, including an Excel spreadsheet graphing Lorenz curves and calculating Gini coefficients as well as coefficients of variation. LORENZ 3.0 is a Mathematica notebook which draw sample Lorenz curves and calculates Gini coefficients and Lorenz asymmetry coefficients from data in an Excel sheet. Economics curves Welfare economics Statistical charts and diagrams Income inequality metrics	[ -0.0840805172920227, -0.4723968505859375, 0.18260878324508667, 0.2954291105270386, -0.06375167518854141, 0.41333597898483276, -0.34976455569267273, 0.0013366366038098931, -0.3091840445995331, -0.5603542923927307, -0.24151283502578735, 0.7019066214561462, -0.17669111490249634, 0.44008952379...
18136	https://en.wikipedia.org/wiki/Literate%20programming	Literate programming	Literate programming is a programming paradigm introduced by Donald Knuth in which a computer program is given an explanation of its logic in a natural language, such as English, interspersed with snippets of macros and traditional source code, from which compilable source code can be generated. The approach is used in scientific computing and in data science routinely for reproducible research and open access purposes. Literate programming tools are used by millions of programmers today. The literate programming paradigm, as conceived by Knuth, represents a move away from writing computer programs in the manner and order imposed by the computer, and instead enables programmers to develop programs in the order demanded by the logic and flow of their thoughts. Literate programs are written as an uninterrupted exposition of logic in an ordinary human language, much like the text of an essay, in which macros are included to hide abstractions and traditional source code. Literate programming (LP) tools are used to obtain two representations from a literate source file: one suitable for further compilation or execution by a computer, the "tangled" code, and another for viewing as formatted documentation, which is said to be "woven" from the literate source. While the first generation of literate programming tools were computer language-specific, the later ones are language-agnostic and exist above the programming languages. History and philosophy Literate programming was first introduced by Knuth in 1984. The main intention behind this approach was to treat a program as literature understandable to human beings. This approach was implemented at Stanford University as a part of research on algorithms and digital typography. This implementation was called "WEB" by Knuth since he believed that it was one of the few three-letter words of English that hadn't already been applied to computing. However, it correctly resembles the complicated nature of software delicately pieced together from simple materials. The practice of literate programming has seen an important resurgence in the 2010s with the use of computational notebooks, especially in data science. Concept Literate programming is writing out the program logic in a human language with included (separated by a primitive markup) code snippets and macros. Macros in a literate source file are simply title-like or explanatory phrases in a human language that describe human abstractions created while solving the programming problem, and hiding chunks of code or lower-level macros. These macros are similar to the algorithms in pseudocode typically used in teaching computer science. These arbitrary explanatory phrases become precise new operators, created on the fly by the programmer, forming a meta-language on top of the underlying programming language. A preprocessor is used to substitute arbitrary hierarchies, or rather "interconnected 'webs' of macros", to produce the compilable source code with one command ("tangle"), and documentation with another ("weave"). The preprocessor also provides an ability to write out the content of the macros and to add to already created macros in any place in the text of the literate program source file, thereby disposing of the need to keep in mind the restrictions imposed by traditional programming languages or to interrupt the flow of thought. Advantages According to Knuth, literate programming provides higher-quality programs, since it forces programmers to explicitly state the thoughts behind the program, making poorly thought-out design decisions more obvious. Knuth also claims that literate programming provides a first-rate documentation system, which is not an add-on, but is grown naturally in the process of exposition of one's thoughts during a program's creation. The resulting documentation allows the author to restart his own thought processes at any later time, and allows other programmers to understand the construction of the program more easily. This differs from traditional documentation, in which a programmer is presented with source code that follows a compiler-imposed order, and must decipher the thought process behind the program from the code and its associated comments. The meta-language capabilities of literate programming are also claimed to facilitate thinking, giving a higher "bird's eye view" of the code and increasing the number of concepts the mind can successfully retain and process. Applicability of the concept to programming on a large scale, that of commercial-grade programs, is proven by an edition of TeX code as a literate program. Knuth also claims that literate programming can lead to easy porting of software to multiple environments, and even cites the implementation of TeX as an example. Contrast with documentation generation Literate programming is very often misunderstood to refer only to formatted documentation produced from a common file with both source code and comments – which is properly called documentation generation – or to voluminous commentaries included with code. This is the converse of literate programming: well-documented code or documentation extracted from code follows the structure of the code, with documentation embedded in the code; while in literate programming, code is embedded in documentation, with the code following the structure of the documentation. This misconception has led to claims that comment-extraction tools, such as the Perl Plain Old Documentation or Java Javadoc systems, are "literate programming tools". However, because these tools do not implement the "web of abstract concepts" hiding behind the system of natural-language macros, or provide an ability to change the order of the source code from a machine-imposed sequence to one convenient to the human mind, they cannot properly be called literate programming tools in the sense intended by Knuth. Critique In 1986, Jon Bentley asked Knuth to demonstrate the concept of literate programming for his Programming Pearls column in the Communications of the ACM, by writing a program in WEB. Knuth sent him a program for a problem previously discussed in the column (that of sampling M random numbers in the range 1..N), and also asked for an "assignment". Bentley gave him the problem of finding the K most common words from a text file, for which Knuth wrote a WEB program that was published together with a review by Douglas McIlroy of Bell Labs. McIlroy praised the intricacy of Knuth's solution, his choice of a data structure (a variant of Frank M. Liang's hash trie), and the presentation. He criticized some matters of style, such as the fact that the central idea was described late in the paper, the use of magic constants, and the absence of a diagram to accompany the explanation of the data structure. McIlroy, known for Unix pipelines, also used the review to critique the programming task itself, pointing out that in Unix (developed at Bell Labs), utilities for text processing (tr, sort, uniq and sed) had been written previously that were "staples", and a solution that was easy to implement, debug and reuse could be obtained by combining these utilities in a six-line shell script. In response, Bentley wrote that: McIlroy later admitted that his critique was unfair, since he criticized Knuth's program on engineering grounds, while Knuth's purpose was only to demonstrate the literate programming technique. In 1987, Communications of the ACM published a followup article which illustrated literate programming with a C program that combined artistic approach of Knuth with engineering approach of McIlroy, with a critique by John Gilbert. Workflow Implementing literate programming consists of two steps: Weaving: Generating a comprehensive document about the program and its maintenance. Tangling: Generating machine executable code Weaving and tangling are done on the same source so that they are consistent with each other. Example A classic example of literate programming is the literate implementation of the standard Unix wc word counting program. Knuth presented a CWEB version of this example in Chapter 12 of his Literate Programming book. The same example was later rewritten for the noweb literate programming tool. This example provides a good illustration of the basic elements of literate programming. Creation of macros The following snippet of the wc literate program shows how arbitrary descriptive phrases in a natural language are used in a literate program to create macros, which act as new "operators" in the literate programming language, and hide chunks of code or other macros. The mark-up notation consists of double angle brackets ("<<...>>") that indicate macros, the "@" symbol which indicates the end of the code section in a noweb file. The "<<>>" symbol stands for the "root", topmost node the literate programming tool will start expanding the web of macros from. Actually, writing out the expanded source code can be done from any section or subsection (i.e. a piece of code designated as "<<name of the chunk>>=", with the equal sign), so one literate program file can contain several files with machine source code. The purpose of wc is to count lines, words, and/or characters in a list of files. The number of lines in a file is ......../more explanations/ Here, then, is an overview of the file wc.c that is defined by the noweb program wc.nw: <<>>= <<Header files to include>> <<Definitions>> <<Global variables>> <<Functions>> <<The main program>> @ We must include the standard I/O definitions, since we want to send formatted output to stdout and stderr. <<Header files to include>>= #include <stdio.h> @ The unraveling of the chunks can be done in any place in the literate program text file, not necessarily in the order they are sequenced in the enclosing chunk, but as is demanded by the logic reflected in the explanatory text that envelops the whole program. Program as a web—macros are not just section names Macros are not the same as "section names" in standard documentation. Literate programming macros can hide any chunk of code behind themselves, and be used inside any low-level machine language operators, often inside logical operators such as "if", "while" or "case". This is illustrated by the following snippet of the wc literate program. The present chunk, which does the counting, was actually one of the simplest to write. We look at each character and change state if it begins or ends a word. <<Scan file>>= while (1) { <<Fill buffer if it is empty; break at end of file>> c = ptr++; if (c > ' ' && c < 0177) { / visible ASCII codes / if (!in_word) { word_count++; in_word = 1; } continue; } if (c == '\n') line_count++; else if (c != ' ' && c != '\t') continue; in_word = 0; / c is newline, space, or tab / } @ In fact, macros can stand for any arbitrary chunk of code or other macros, and are thus more general than top-down or bottom-up "chunking", or than subsectioning. Knuth says that when he realized this, he began to think of a program as a web of various parts. Order of human logic, not that of the compiler In a noweb literate program besides the free order of their exposition, the chunks behind macros, once introduced with "<<...>>=", can be grown later in any place in the file by simply writing "<<name of the chunk>>=" and adding more content to it, as the following snippet illustrates ("plus" is added by the document formatter for readability, and is not in the code). The grand totals must be initialized to zero at the beginning of the program. If we made these variables local to main, we would have to do this initialization explicitly; however, C globals are automatically zeroed. (Or rather,``statically zeroed.'' (Get it?) <<Global variables>>+= long tot_word_count, tot_line_count, tot_char_count; / total number of words, lines, chars / @ Record of the train of thought The documentation for a literate program is produced as part of writing the program. Instead of comments provided as side notes to source code a literate program contains the explanation of concepts on each level, with lower level concepts deferred to their appropriate place, which allows for better communication of thought. The snippets of the literate wc above show how an explanation of the program and its source code are interwoven. Such exposition of ideas creates the flow of thought that is like a literary work. Knuth wrote a "novel" which explains the code of the interactive fiction game Colossal Cave Adventure. Remarkable examples Axiom, which is evolved from scratchpad, a computer algebra system developed by IBM. It is now being developed by Tim Daly, one of the developers of scratchpad, Axiom is totally written as a literate program. Literate programming practices The first published literate programming environment was WEB, introduced by Knuth in 1981 for his TeX typesetting system; it uses Pascal as its underlying programming language and TeX for typesetting of the documentation. The complete commented TeX source code was published in Knuth's TeX: The program, volume B of his 5-volume Computers and Typesetting. Knuth had privately used a literate programming system called DOC as early as 1979. He was inspired by the ideas of Pierre-Arnoul de Marneffe. The free CWEB, written by Knuth and Silvio Levy, is WEB adapted for C and C++, runs on most operating systems and can produce TeX and PDF documentation. There are various other implementations of the literate programming concept (some of them don't have macros and hence violate the order of human logic principle): Other useful tools include The Leo text editor is an outlining editor which supports optional noweb and CWEB markup. The author of Leo mixes two different approaches: first, Leo is an outlining editor, which helps with management of large texts; second, Leo incorporates some of the ideas of literate programming, which in its pure form (i.e., the way it is used by Knuth Web tool or tools like "noweb") is possible only with some degree of inventiveness and the use of the editor in a way not exactly envisioned by its author (in modified @root nodes). However, this and other extensions (@file nodes) make outline programming and text management successful and easy and in some ways similar to literate programming. The Haskell programming language has native support for semi-literate programming. The compiler/interpreter supports two file name extensions: .hs and .lhs; the latter stands for literate Haskell. The literate scripts can be full LaTeX source text, at the same time it can be compiled, with no changes, because the interpreter only compiles the text in a code environment, for example: % here text describing the function: \begin{code} fact 0 = 1 fact (n+1) = (n+1) fact n \end{code} here more text The code can be also marked in the Richard Bird style, starting each line with a greater than symbol and a space, preceding and ending the piece of code with blank lines. The LaTeX listings package provides a lstlisting environment which can be used to embellish the source code. It can be used to define a code environment to use within Haskell to print the symbols in the following manner: \newenvironment{code}{\lstlistings[language=Haskell]}{\endlstlistings} \begin{code} comp :: (beta -> gamma) -> (alpha -> beta) -> (alpha -> gamma) (g `comp` f) x = g(f x) \end{code} which can be configured to yield: Although the package does not provide means to organize chunks of code, one can split the LaTeX source code in different files. See listings manual for an overview. The Web 68 Literate Programming system used Algol 68 as the underlying programming language, although there was nothing in the pre-processor 'tang' to force the use of that language. The customization mechanism of the Text Encoding Initiative which enables the constraining, modification, or extension of the TEI scheme enables users to mix prose documentation with fragments of schema specification in their One Document Does-it-all format. From this prose documentation, schemas, and processing model pipelines can be generated and Knuth's Literate Programming paradigm is cited as the inspiration for this way of working. See also Documentation generator – the inverse on literate programming where documentation is embedded in and generated from source code Notebook interface – virtual notebook environment used for literate programming Sweave and Knitr – examples of use of the "noweb"-like Literate Programming tool inside the R language for creation of dynamic statistical reports Self-documenting code – source code that can be easily understood without documentation References Further reading (includes software) External links LiterateProgramming at WikiWikiWeb Literate Programming FAQ at CTAN Articles with example code Computer-related introductions in 1981	[ 0.028330065310001373, 0.16217492520809174, -0.28302785754203796, 0.502288281917572, -0.12382616847753525, 0.6061031818389893, 0.14746332168579102, 0.6023707389831543, 0.31429150700569153, -0.3153064548969269, -0.3610784411430359, 0.6984952688217163, -0.21955417096614838, -0.263991326093673...
18137	https://en.wikipedia.org/wiki/Logistic%20map	Logistic map	The logistic map is a polynomial mapping (equivalently, recurrence relation) of degree 2, often cited as an archetypal example of how complex, chaotic behaviour can arise from very simple non-linear dynamical equations. The map was popularized in a 1976 paper by the biologist Robert May, in part as a discrete-time demographic model analogous to the logistic equation written down by Pierre François Verhulst. Mathematically, the logistic map is written where is a number between zero and one, that represents the ratio of existing population to the maximum possible population. This nonlinear difference equation is intended to capture two effects: reproduction where the population will increase at a rate proportional to the current population when the population size is small. starvation (density-dependent mortality) where the growth rate will decrease at a rate proportional to the value obtained by taking the theoretical "carrying capacity" of the environment less the current population. The usual values of interest for the parameter are those in the interval , so that remains bounded on . The case of the logistic map is a nonlinear transformation of both the bit-shift map and the case of the tent map. If this leads to negative population sizes. (This problem does not appear in the older Ricker model, which also exhibits chaotic dynamics.) One can also consider values of in the interval , so that remains bounded on . Characteristics of the map Behavior dependent on The image below shows the amplitude and frequency content of some logistic map iterates for parameter values ranging from 2 to 4. By varying the parameter , the following behavior is observed: With between 0 and 1, the population will eventually die, independent of the initial population. With between 1 and 2, the population will quickly approach the value , independent of the initial population. With between 2 and 3, the population will also eventually approach the same value , but first will fluctuate around that value for some time. The rate of convergence is linear, except for , when it is dramatically slow, less than linear (see Bifurcation memory). With between 3 and 1 + ≈ 3.44949 the population will approach permanent oscillations between two values. These two values are dependent on and given by . With between 3.44949 and 3.54409 (approximately), from almost all initial conditions the population will approach permanent oscillations among four values. The latter number is a root of a 12th degree polynomial . With increasing beyond 3.54409, from almost all initial conditions the population will approach oscillations among 8 values, then 16, 32, etc. The lengths of the parameter intervals that yield oscillations of a given length decrease rapidly; the ratio between the lengths of two successive bifurcation intervals approaches the Feigenbaum constant . This behavior is an example of a period-doubling cascade. At is the onset of chaos, at the end of the period-doubling cascade. From almost all initial conditions, we no longer see oscillations of finite period. Slight variations in the initial population yield dramatically different results over time, a prime characteristic of chaos. Most values of beyond 3.56995 exhibit chaotic behaviour, but there are still certain isolated ranges of that show non-chaotic behavior; these are sometimes called islands of stability. For instance, beginning at 1 + (approximately 3.82843) there is a range of parameters that show oscillation among three values, and for slightly higher values of oscillation among 6 values, then 12 etc. The development of the chaotic behavior of the logistic sequence as the parameter varies from approximately 3.56995 to approximately 3.82843 is sometimes called the Pomeau–Manneville scenario, characterized by a periodic (laminar) phase interrupted by bursts of aperiodic behavior. Such a scenario has an application in semiconductor devices. There are other ranges that yield oscillation among 5 values etc.; all oscillation periods occur for some values of . A period-doubling window with parameter is a range of -values consisting of a succession of subranges. The th subrange contains the values of for which there is a stable cycle (a cycle that attracts a set of initial points of unit measure) of period . This sequence of sub-ranges is called a cascade of harmonics. In a sub-range with a stable cycle of period , there are unstable cycles of period for all . The value at the end of the infinite sequence of sub-ranges is called the point of accumulation of the cascade of harmonics. As rises there is a succession of new windows with different values. The first one is for ; all subsequent windows involving odd occur in decreasing order of starting with arbitrarily large . Beyond , almost all initial values eventually leave the interval and diverge. For any value of there is at most one stable cycle. If a stable cycle exists, it is globally stable, attracting almost all points. Some values of with a stable cycle of some period have infinitely many unstable cycles of various periods. The bifurcation diagram at right summarizes this. The horizontal axis shows the possible values of the parameter while the vertical axis shows the set of values of visited asymptotically from almost all initial conditions by the iterates of the logistic equation with that value. The bifurcation diagram is a self-similar: if we zoom in on the above-mentioned value and focus on one arm of the three, the situation nearby looks like a shrunk and slightly distorted version of the whole diagram. The same is true for all other non-chaotic points. This is an example of the deep and ubiquitous connection between chaos and fractals. We can also consider negative values of : For between -2 and -1 the logistic sequence also features chaotic behavior. With between -1 and 1 - and for 0 between 1/ and 1-1/, the population will approach permanent oscillations between two values, as with the case of between 3 and 1 + , and given by the same formula. Chaos and the logistic map The relative simplicity of the logistic map makes it a widely used point of entry into a consideration of the concept of chaos. A rough description of chaos is that chaotic systems exhibit a great sensitivity to initial conditions—a property of the logistic map for most values of between about 3.57 and 4 (as noted above). A common source of such sensitivity to initial conditions is that the map represents a repeated folding and stretching of the space on which it is defined. In the case of the logistic map, the quadratic difference equation describing it may be thought of as a stretching-and-folding operation on the interval . The following figure illustrates the stretching and folding over a sequence of iterates of the map. Figure (a), left, shows a two-dimensional Poincaré plot of the logistic map's state space for , and clearly shows the quadratic curve of the difference equation (). However, we can embed the same sequence in a three-dimensional state space, in order to investigate the deeper structure of the map. Figure (b), right, demonstrates this, showing how initially nearby points begin to diverge, particularly in those regions of corresponding to the steeper sections of the plot. This stretching-and-folding does not just produce a gradual divergence of the sequences of iterates, but an exponential divergence (see Lyapunov exponents), evidenced also by the complexity and unpredictability of the chaotic logistic map. In fact, exponential divergence of sequences of iterates explains the connection between chaos and unpredictability: a small error in the supposed initial state of the system will tend to correspond to a large error later in its evolution. Hence, predictions about future states become progressively (indeed, exponentially) worse when there are even very small errors in our knowledge of the initial state. This quality of unpredictability and apparent randomness led the logistic map equation to be used as a pseudo-random number generator in early computers. Since the map is confined to an interval on the real number line, its dimension is less than or equal to unity. Numerical estimates yield a correlation dimension of (Grassberger, 1983), a Hausdorff dimension of about 0.538 (Grassberger 1981), and an information dimension of approximately 0.5170976 (Grassberger 1983) for (onset of chaos). Note: It can be shown that the correlation dimension is certainly between 0.4926 and 0.5024. It is often possible, however, to make precise and accurate statements about the likelihood of a future state in a chaotic system. If a (possibly chaotic) dynamical system has an attractor, then there exists a probability measure that gives the long-run proportion of time spent by the system in the various regions of the attractor. In the case of the logistic map with parameter and an initial state in , the attractor is also the interval and the probability measure corresponds to the beta distribution with parameters and . Specifically, the invariant measure is Unpredictability is not randomness, but in some circumstances looks very much like it. Hence, and fortunately, even if we know very little about the initial state of the logistic map (or some other chaotic system), we can still say something about the distribution of states arbitrarily far into the future, and use this knowledge to inform decisions based on the state of the system. Special cases of the map Upper bound when Although exact solutions to the recurrence relation are only available in a small number of cases, a closed-form upper bound on the logistic map is known when . There are two aspects of the behavior of the logistic map that should be captured by an upper bound in this regime: the asymptotic geometric decay with constant , and the fast initial decay when is close to 1, driven by the term in the recurrence relation. The following bound captures both of these effects: Solution when The special case of can in fact be solved exactly, as can the case with ; however, the general case can only be predicted statistically. The solution when is, where the initial condition parameter is given by For rational , after a finite number of iterations maps into a periodic sequence. But almost all are irrational, and, for irrational , never repeats itself – it is non-periodic. This solution equation clearly demonstrates the two key features of chaos – stretching and folding: the factor shows the exponential growth of stretching, which results in sensitive dependence on initial conditions, while the squared sine function keeps folded within the range . For an equivalent solution in terms of complex numbers instead of trigonometric functions is where is either of the complex numbers with modulus equal to 1. Just as the squared sine function in the trigonometric solution leads to neither shrinkage nor expansion of the set of points visited, in the latter solution this effect is accomplished by the unit modulus of . By contrast, the solution when is for . Since for any value of other than the unstable fixed point 0, the term goes to 0 as goes to infinity, so goes to the stable fixed point . Finding cycles of any length when For the case, from almost all initial conditions the iterate sequence is chaotic. Nevertheless, there exist an infinite number of initial conditions that lead to cycles, and indeed there exist cycles of length for all integers . We can exploit the relationship of the logistic map to the dyadic transformation (also known as the bit-shift map) to find cycles of any length. If follows the logistic map and follows the dyadic transformation then the two are related by a homeomorphism The reason that the dyadic transformation is also called the bit-shift map is that when is written in binary notation, the map moves the binary point one place to the right (and if the bit to the left of the binary point has become a "1", this "1" is changed to a "0"). A cycle of length 3, for example, occurs if an iterate has a 3-bit repeating sequence in its binary expansion (which is not also a one-bit repeating sequence): 001, 010, 100, 110, 101, or 011. The iterate 001001001... maps into 010010010..., which maps into 100100100..., which in turn maps into the original 001001001...; so this is a 3-cycle of the bit shift map. And the other three binary-expansion repeating sequences give the 3-cycle 110110110... → 101101101... → 011011011... → 110110110.... Either of these 3-cycles can be converted to fraction form: for example, the first-given 3-cycle can be written as → → → . Using the above translation from the bit-shift map to the logistic map gives the corresponding logistic cycle 0.611260467... → 0.950484434... → 0.188255099... → 0.611260467.... We could similarly translate the other bit-shift 3-cycle into its corresponding logistic cycle. Likewise, cycles of any length can be found in the bit-shift map and then translated into the corresponding logistic cycles. However, since almost all numbers in are irrational, almost all initial conditions of the bit-shift map lead to the non-periodicity of chaos. This is one way to see that the logistic map is chaotic for almost all initial conditions. The number of cycles of (minimal) length for the logistic map with (tent map with ) is a known integer sequence : 2, 1, 2, 3, 6, 9, 18, 30, 56, 99, 186, 335, 630, 1161.... This tells us that the logistic map with has 2 fixed points, 1 cycle of length 2, 2 cycles of length 3 and so on. This sequence takes a particularly simple form for prime : . For example: 2 ⋅ = 630 is the number of cycles of length 13. Since this case of the logistic map is chaotic for almost all initial conditions, all of these finite-length cycles are unstable. Related concepts Feigenbaum universality of 1-D maps Universality of one-dimensional maps with parabolic maxima and Feigenbaum constants , is well visible with map proposed as a toy model for discrete laser dynamics: , where stands for electric field amplitude, is laser gain as bifurcation parameter. The gradual increase of at interval changes dynamics from regular to chaotic one with qualitatively the same bifurcation diagram as those for logistic map. See also Logistic function, solution of the logistic map's continuous counterpart: the Logistic differential equation. Lyapunov stability#Definition for discrete-time systems Malthusian growth model Periodic points of complex quadratic mappings, of which the logistic map is a special case confined to the real line Radial basis function network, which illustrates the inverse problem for the logistic map. Schröder's equation Stiff equation Notes References External links The Chaos Hypertextbook. An introductory primer on chaos and fractals. An interactive visualization of the logistic map as a Jupyter notebook The Logistic Map and Chaos by Elmer G. Wiens Complexity & Chaos (audiobook) by Roger White. Chapter 5 covers the Logistic Equation. "History of iterated maps," in A New Kind of Science by Stephen Wolfram. Champaign, IL: Wolfram Media, p. 918, 2002. "A very brief history of universality in period doubling" by P. Cvitanović "A not so short history of Universal Function" by P. Cvitanović Discrete Logistic Equation by Marek Bodnar after work by Phil Ramsden, Wolfram Demonstrations Project. Multiplicative coupling of 2 logistic maps by C. Pellicer-Lostao and R. Lopez-Ruiz after work by Ed Pegg Jr, Wolfram Demonstrations Project. Using SAGE to investigate the discrete logistic equation Chaotic maps	[ -0.7698128819465637, -0.299638032913208, 0.04118947312235832, 0.25520849227905273, -0.264932781457901, 0.0342315211892128, -0.1390792429447174, -0.1942920982837677, -0.23324429988861084, -0.7689796090126038, -0.4142366051673889, 0.41106486320495605, -0.6215355396270752, 0.00456813396885991...
18138	https://en.wikipedia.org/wiki/Levant	Levant	The Levant () is an approximate historical geographical term referring to a large area in the Eastern Mediterranean region of Western Asia. In its narrowest sense, which is in use today in archaeology and other cultural contexts, it is equivalent to a stretch of land bordering the Mediterranean in southwestern Asia, i.e. the historical region of Syria ("greater Syria"), which includes present-day Syria, Lebanon, Jordan, Israel, Palestinian territories and most of Turkey southwest of the middle Euphrates. Its overwhelming characteristic is that it represents the land bridge between Africa and Eurasia. In its widest historical sense, the Levant included all of the Eastern Mediterranean with its islands; that is, it included all of the countries along the Eastern Mediterranean shores, extending from Greece to Cyrenaica in eastern Libya. The term entered English in the late 15th century from French. It derives from the Italian , meaning "rising", implying the rising of the Sun in the east, and is broadly equivalent to the term al-Mashriq (, ), meaning "the eastern place, where the Sun rises". In the 13th and 14th centuries, the term levante was used for Italian maritime commerce in the Eastern Mediterranean, including Greece, Anatolia, Syria-Palestine, and Egypt, that is, the lands east of Venice. Eventually the term was restricted to the Muslim countries of Syria-Palestine and Egypt. In 1581, England set up the Levant Company to monopolize commerce with the Ottoman Empire. The name Levant States was used to refer to the French mandate over Syria and Lebanon after World War I. This is probably the reason why the term Levant has come to be used more specifically to refer to modern Syria, Lebanon, Palestine, Israel, Jordan, and Cyprus. Some scholars mistakenly believed that it derives from the name of Lebanon. Today the term is often used in conjunction with prehistoric or ancient historical references. It has the same meaning as "Syria-Palestine" or Ash-Shaam (, ), the area that is bounded by the Taurus Mountains of Turkey in the north, the Mediterranean Sea in the west, the north Arabian Desert and Mesopotamia in the east, and Sinai in the south (which can be fully included or not). Typically, it does not include Anatolia (also called Asia Minor), the Caucasus Mountains, or any part of the Arabian Peninsula proper. Cilicia (in Asia Minor) and the Sinai Peninsula (Asian Egypt) are sometimes included. As a name for the contemporary region, several dictionaries consider Levant to be archaic today. Both the noun Levant and the adjective Levantine are now commonly used to describe the ancient and modern culture area formerly called Syro-Palestinian or Biblical: archaeologists now speak of the Levant and of Levantine archaeology; food scholars speak of Levantine cuisine; and the Latin Christians of the Levant continue to be called Levantine Christians. The Levant has been described as the "crossroads of western Asia, the eastern Mediterranean, and northeast Africa", and in geological (tectonic) terms as the "northwest of the Arabian plate". The populations of the Levant share not only the geographic position, but cuisine, some customs, and history. They are often referred to as Levantines. Etymology The term Levant appears in English in 1497, and originally meant 'the East' or 'Mediterranean lands east of Italy'. It is borrowed from the French 'rising', referring to the rising of the sun in the east, or the point where the sun rises. The phrase is ultimately from the Latin word , meaning 'lift, raise'. Similar etymologies are found in Greek (Anatolē, cf. Anatolia), in Germanic Morgenland (), in Italian (as in 'Riviera di Levante', the portion of the Liguria coast east of Genoa), in Hungarian Kelet, in Spanish and Catalan Levante and Llevant, ("the place of rising"), and in Hebrew (, mizrah, 'east'). Most notably, "Orient" and its Latin source oriens meaning "east", is literally "rising", deriving from Latin orior "rise". The notion of the Levant has undergone a dynamic process of historical evolution in usage, meaning, and understanding. While the term "Levantine" originally referred to the European residents of the eastern Mediterranean region, it later came to refer to regional "native" and "minority" groups. The term became current in English in the 16th century, along with the first English merchant adventurers in the region; English ships appeared in the Mediterranean in the 1570s, and the English merchant company signed its agreement ("capitulations") with the Ottoman Sultan in 1579. The English Levant Company was founded in 1581 to trade with the Ottoman Empire, and in 1670 the French Compagnie du Levant was founded for the same purpose. At this time, the Far East was known as the "Upper Levant". In early 19th-century travel writing, the term sometimes incorporated certain Mediterranean provinces of the Ottoman empire, as well as independent Greece (and especially the Greek islands). In 19th-century archaeology, it referred to overlapping cultures in this region during and after prehistoric times, intending to reference the place instead of any one culture. The French mandate of Syria and Lebanon (1920–1946) was called the Levant states. Geography and modern-day use of the term Today, "Levant" is the term typically used by archaeologists and historians with reference to the history of the region. Scholars have adopted the term Levant to identify the region due to it being a "wider, yet relevant, cultural corpus" that does not have the "political overtones" of Syria-Palestine. The term is also used for modern events, peoples, states or parts of states in the same region, namely Cyprus, Egypt, Iraq, Israel, Jordan, Lebanon, Palestine, Syria, and Turkey are sometimes considered Levant countries (compare with Near East, Middle East, Eastern Mediterranean and Western Asia). Several researchers include the island of Cyprus in Levantine studies, including the Council for British Research in the Levant, the UCLA Near Eastern Languages and Cultures department, Journal of Levantine Studies and the UCL Institute of Archaeology, the last of which has dated the connection between Cyprus and mainland Levant to the early Iron Age. Archaeologists seeking a neutral orientation that is neither biblical nor national have used terms such as Levantine archaeology and archaeology of the Southern Levant. While the usage of the term "Levant" in academia has been restricted to the fields of archeology and literature, there is a recent attempt to reclaim the notion of the Levant as a category of analysis in political and social sciences. Two academic journals were launched in the early 2010s using the word: the Journal of Levantine Studies, published by the Van Leer Jerusalem Institute and The Levantine Review, published by Boston College. The word Levant has been used in some translations of the term ash-Shām as used by the organization known as ISIL, ISIS, and other names, though there is disagreement as to whether this translation is accurate. In archaeology: a definition In The Oxford Handbook of the Archaeology of the Levant: c. 8000–332 BCE (OHAL; 2013), the definition of the Levant for the specific purposes of the book is synonymous to that of the Arabic "bilad al-sham, 'the land of sham [Syria]'", translating in Western parlance to greater Syria. OHAL defines the boundaries of the Levant as follows. To the north: the Taurus Mountains or the Plain of 'Amuq To the east: the eastern deserts, i.e. (from north to south) the Euphrates and the Jebel el-Bishrī area for the northern Levant, followed by the Syrian Desert east of the eastern hinterland of the Anti-Lebanon range (whose southernmost part is Mount Hermon), and Transjordan's highlands and eastern desert (also discussed at Syrian Desert, also known as the Badia region). In other words, Mesopotamia and the North Arabian Desert. To the south: Wadi al-Arish in Sinai To the west: the Mediterranean Sea Subregions A distinction is made between the main subregions of the Levant, the northern and the southern: The Litani River marks the division between the Northern Levant and the Southern Levant. The island of Cyprus is also included as a third subregion in the archaeological region of the Levant: Cyprus, geographically distinct from the Levant, is included due to its proximity and natural resources (copper in particular), which induced close cultural ties. History Demographics and religion The largest religious group in the Levant are the Muslims and the largest cultural-linguistic group are Arabs. Muslim Arabs became the majority due to the Muslim conquest of the Levant in the 7th century and subsequent Arabization of the region. The majority of Muslim Levantines are Sunni with Alawi and Shia minorities. Other large ethnic groups in the Levant include Jews, Maronites, Kurds, Turks, Turkmens, Antiochian Greeks, Assyrians, Yazidi Kurds, Druze and Armenians. There are many Levantine Christian groups such as Greek, Oriental Orthodox (mainly Syriac Orthodox, Coptic, Georgian, and Maronite), Roman Catholic, Nestorian, and Protestant. Armenians mostly belong to the Armenian Apostolic Church. There are Levantines or Franco-Levantines who are mostly Roman Catholic. There are also Circassians, Turks, Samaritans, and Nawars. There are Assyrian peoples belonging to the Assyrian Church of the East (autonomous) and the Chaldean Catholic Church (Catholic). In addition, this region has a number of sites that are of religious significance, such as Al-Aqsa Mosque, Antioch in Hatay, the Church of the Holy Sepulchre, and the Western Wall in Jerusalem. Language Most populations in the Levant speak Levantine Arabic (, ), usually classified as the varieties North Levantine Arabic in Lebanon, Syria, and parts of Turkey, and South Levantine Arabic in Palestine and Jordan. Each of these encompasses a spectrum of regional or urban/rural variations. In addition to the varieties normally grouped together as "Levantine", a number of other varieties and dialects of Arabic are spoken in the Levant area, such as Levantine Bedawi Arabic and Mesopotamian Arabic. Among the languages of Israel, the official language is Hebrew; Arabic was until July 19, 2018, also an official language. The Arab minority, in 2018 about 21% of the population of Israel, speaks a dialect of Levantine Arabic essentially indistinguishable from the forms spoken in the Palestinian territories. Of the languages of Cyprus, the majority language is Greek, followed by Turkish (in the north). Two minority languages are recognized: Armenian, and Cypriot Maronite Arabic, a hybrid of mostly medieval Arabic vernaculars with strong influence from contact with Greek, spoken by approximately 1,000 people. Some communities and populations speak Aramaic, Greek, Armenian, Circassian, French, Russian, or English. See also Overlapping regional designations Fertile Crescent Mashriq Mesopotamia Middle East Near East Western Asia Subregional designations Southern Levant Others French post offices in the Ottoman Empire ("Levant" stamps) History of the Levant Islamic State of Iraq and the Levant (Referred to in current events as ISIL or ISIS) Levantine Sea Levantines (Latin Christians), Catholic Europeans in the Levant Other places in the east of a larger region Levante, Spain Riviera di Levante, Italy Notes References Bibliography Further reading Julia Chatzipanagioti: Griechenland, Zypern, Balkan und Levante. Eine kommentierte Bibliographie der Reiseliteratur des 18. Jahrhunderts. 2 Vol. Eutin 2006. Levantine Heritage site. Includes many oral and scholarly histories, and genealogies for some Levantine Turkish families. Philip Mansel, Levant: Splendour and Catastrophe on the Mediterranean, London, John Murray, 11 November 2010, hardback, 480 pages, , New Haven, Yale University Press, 24 May 2011, hardback, 470 pages, External links France and the Levant Eastern Mediterranean Near East Geography of the Middle East History of Western Asia Regions of Europe Geography of Cyprus Geography of Israel Geography of Jordan Geography of Lebanon Geography of the State of Palestine Geography of Syria Geography of Hatay Province Regions of Asia Historical regions	[ -0.251630961894989, 0.25410741567611694, -0.49194324016571045, -0.6015968918800354, 0.4391859173774719, 0.3870405852794647, -0.07562597095966339, 0.6961724758148193, -0.15535686910152435, -0.18119646608829498, -0.5119965672492981, 0.04009212553501129, -0.2740745544433594, 0.558103442192077...
18139	https://en.wikipedia.org/wiki/League%20of%20Nations%20mandate	League of Nations mandate	A League of Nations mandate was a legal status for certain territories transferred from the control of one country to another following World War I, or the legal instruments that contained the internationally agreed-upon terms for administering the territory on behalf of the League of Nations. These were of the nature of both a treaty and a constitution, which contained minority rights clauses that provided for the rights of petition and adjudication by the Permanent Court of International Justice. The mandate system was established under Article 22 of the Covenant of the League of Nations, entered into force on 28 June 1919. With the dissolution of the League of Nations after World War II, it was stipulated at the Yalta Conference that the remaining Mandates should be placed under the trusteeship of the United Nations, subject to future discussions and formal agreements. Most of the remaining mandates of the League of Nations (with the exception of South-West Africa) thus eventually became United Nations Trust Territories. Two governing principles formed the core of the Mandate System, being non-annexation of the territory and its administration as a "sacred trust of civilisation" to develop the territory for the benefit of its native people. Basis The mandate system was established by Article 22 of the Covenant of the League of Nations, drafted by the victors of World War I. The article referred to territories which after the war were no longer ruled by their previous sovereign, but their peoples were not considered "able to stand by themselves under the strenuous conditions of the modern world". The article called for such people's tutelage to be "entrusted to advanced nations who by reason of their resources, their experience or their geographical position can best undertake this responsibility". Woodrow Wilson and Jan Smuts played influential roles in pushing for the establishment of a mandates system. Generalities All of the territories subject to League of Nations mandates were previously controlled by states defeated in World War I, principally Imperial Germany and the Ottoman Empire. The mandates were fundamentally different from the protectorates in that the Mandatory power undertook obligations to the inhabitants of the territory and to the League of Nations. The process of establishing the mandates consisted of two phases: The formal removal of sovereignty of the state previously controlling the territory. The transfer of mandatory powers to individual states among the Allied Powers. Treaties The divestiture of Germany's overseas colonies, along with three territories disentangled from its European homeland area (the Free City of Danzig, Memel Territory, and Saar), was accomplished in the Treaty of Versailles (1919), with the territories being allotted among the Allies on 7 May of that year. Ottoman territorial claims were first addressed in the Treaty of Sèvres (1920) and finalised in the Treaty of Lausanne (1923). The Turkish territories were allotted among the Allied Powers at the San Remo conference in 1920. Types of mandates The League of Nations decided the exact level of control by the Mandatory power over each mandate on an individual basis. However, in every case the Mandatory power was forbidden to construct fortifications or raise an army within the territory of the mandate, and was required to present an annual report on the territory to the Permanent Mandates Commission of the League of Nations. The mandates were divided into three distinct groups based upon the level of development each population had achieved at that time. The first group, or Class A mandates, were territories formerly controlled by the Ottoman Empire that were deemed to "... have reached a stage of development where their existence as independent nations can be provisionally recognized subject to the rendering of administrative advice and assistance by a Mandatory until such time as they are able to stand alone. The wishes of these communities must be a principal consideration in the selection of the Mandatory." The second group of mandates, or Class B mandates, were all former German colonies in West and Central Africa, referred to by Germany as (protectorates or territories), which were deemed to require a greater level of control by the mandatory power: "...the Mandatory must be responsible for the administration of the territory under conditions which will guarantee freedom of conscience and religion." The mandatory power was forbidden to construct military or naval bases within the mandates. The Class C mandates, including South West Africa and certain of the South Pacific Islands, were considered to be "best administered under the laws of the Mandatory as integral portions of its territory" List of mandates Column header abbreviations: C = Class, sov. = sovereignty Rules of establishment According to the Council of the League of Nations, meeting of August 1920: "draft mandates adopted by the Allied and Associated Powers would not be definitive until they had been considered and approved by the League ... the legal title held by the mandatory Power must be a double one: one conferred by the Principal Powers and the other conferred by the League of Nations," Three steps were required to establish a Mandate under international law: (1) The Principal Allied and Associated Powers confer a mandate on one of their number or on a third power; (2) the principal powers officially notify the council of the League of Nations that a certain power has been appointed mandatory for such a certain defined territory; and (3) the council of the League of Nations takes official cognisance of the appointment of the mandatory power and informs the latter that it [the council] considers it as invested with the mandate, and at the same time notifies it of the terms of the mandate, after ascertaining whether they are in conformance with the provisions of the covenant." The U.S. State Department Digest of International Law says that the terms of the Treaty of Lausanne provided for the application of the principles of state succession to the "A" Mandates. The Treaty of Versailles (1920) provisionally recognised the former Ottoman communities as independent nations. It also required Germany to recognise the disposition of the former Ottoman territories and to recognise the new states laid down within their boundaries. The terms of the Treaty of Lausanne (1923) required the newly created states that acquired the territory detached from the Ottoman Empire to pay annuities on the Ottoman public debt and to assume responsibility for the administration of concessions that had been granted by the Ottomans. The treaty also let the States acquire, without payment, all the property and possessions of the Ottoman Empire situated within their territory. The treaty provided that the League of Nations was responsible for establishing an arbitral court to resolve disputes that might arise and stipulated that its decisions were final. A disagreement regarding the legal status and the portion of the annuities to be paid by the "A" mandates was settled when an Arbitrator ruled that some of the mandates contained more than one State:The difficulty arises here how one is to regard the Asiatic countries under the British and French mandates. Iraq is a Kingdom in regard to which Great Britain has undertaken responsibilities equivalent to those of a Mandatory Power. Under the British mandate, Palestine and Transjordan have each an entirely separate organization. We are, therefore, in the presence of three States sufficiently separate to be considered as distinct Parties. France has received a single mandate from the Council of the League of Nations, but in the countries subject to that mandate, one can distinguish two distinct States: Syria and the Lebanon, each State possessing its own constitution and a nationality clearly different from the other. Later history After the United Nations was founded in 1945 and the League of Nations was disbanded, all but one of the mandated territories that remained under the control of the mandatory power became United Nations trust territories, a roughly equivalent status. In each case, the colonial power that held the mandate on each territory became the administering power of the trusteeship, except that Japan, which had been defeated in World War II, lost its mandate over the South Pacific islands, which became a "strategic trust territory" known as the Trust Territory of the Pacific Islands under United States administration. The sole exception to the transformation of the League of Nations mandates into UN trusteeships was that South Africa refused to place South-West Africa under trusteeship. Instead, South Africa proposed that it be allowed to annex South-West Africa, a proposal rejected by the United Nations General Assembly. The International Court of Justice held that South Africa continued to have international obligations under the mandate for South-West Africa. The territory finally attained independence in 1990 as Namibia, after a long guerrilla war of independence against the apartheid regime. Nearly all the former League of Nations mandates had become sovereign states by 1990, including all of the former United Nations Trust Territories with the exception of a few successor entities of the gradually dismembered Trust Territory of the Pacific Islands (formerly Japan's South Pacific Trust Mandate). These exceptions include the Northern Mariana Islands which is a commonwealth in political union with the United States with the status of unincorporated organised territory. The Northern Mariana Islands does elect its own governor to serve as territorial head of government, but it remains a U.S. territory with its head of state being the President of the United States and federal funds to the Commonwealth administered by the Office of Insular Affairs of the United States Department of the Interior. Remnant Micronesia and the Marshall Islands, the heirs of the last territories of the Trust, attained final independence on 22 December 1990. (The UN Security Council ratified termination of trusteeship, effectively dissolving trusteeship status, on 10 July 1987.) The Republic of Palau, split off from the Federated States of Micronesia, became the last to effectively get its independence, on 1 October 1994. See also United Nations trust territories Sources and references Anghie, Antony "Colonialism and the Birth of International Institutions: Sovereignty, Economy, and the Mandate System of the League of Nations" 34 (3) New York University Journal of International Law and Politics 513 (2002) Nele Matz, Civilization and the Mandate System under the League of Nations as Origin of Trusteeship, in: A. von Bogdandy and R. Wolfrum, (eds.), Max Planck Yearbook of United Nations Law, Volume 9, 2005, p. 47–95. Pugh, Jeffrey, "Whose Brother's Keeper? International Trusteeship and the Search for Peace in the Palestinian Territories", International Studies Perspectives 13, no. 4 (November 2012): 321–343. Tamburini, Francesco "I mandati della Società delle Nazioni", in Africana, Rivista di Studi Extraeuropei, n.XV – 2009, pp. 99–122. Further reading Bruce, Scot David, Woodrow Wilson's Colonial Emissary: Edward M. House and the Origins of the Mandate System, 1917–1919 (University of Nebraska Press, 2013). Callahan, Michael D. Mandates and empire: the League of Nations and Africa, 1914–1931 (Brighton: Sussex Academic Press, 1999) Haas, Ernst B. "The reconciliation of conflicting colonial policy aims: acceptance of the League of Nations mandate system," International Organization (1952) 6#4 pp: 521–536. Margalith, Aaron M. The International Mandates (1930) online Pedersen, Susan. The Guardians: the League of Nations and the Crisis of Empire, (New York: Oxford University Press, 2015) Sluglett, Peter. "An improvement on colonialism? The 'A' mandates and their legacy in the Middle East," International Affairs (2014) 90#2 pp. 413–427. On the former Arab provinces of the Ottoman Empire References * 1946 disestablishments 20th century in Japan Decolonization French colonial empire Governance of the British Empire	[ 0.34462013840675354, -0.4718708097934723, -0.4891103506088257, 0.15806880593299866, -0.6046571135520935, -0.49365177750587463, 0.013208664953708649, 0.2207777053117752, -0.015834635123610497, -0.18877007067203522, -0.3731864392757416, -0.1942378133535385, -0.3519066870212555, 0.58221393823...
18142	https://en.wikipedia.org/wiki/Loudon%20Classic	Loudon Classic	The Loudon Classic, held at the New Hampshire Motor Speedway (formerly Bryar Motorsport Park and New Hampshire International Speedway) is the longest running motorcycle race in the United States, and is held every year on Father's Day. While it is popularly known as Laconia, the location of the race was moved from Belknap Recreation Area to Loudon in 1964. References Motorsport in New Hampshire Motorcycle races Recurring sporting events established in 1934 Annual sporting events in the United States	[ -0.3495236337184906, 0.014279024675488472, 0.10344325751066208, -0.09759781509637833, 0.3261948525905609, -0.4441226124763489, 0.6156231164932251, 0.5887359380722046, -0.36522525548934937, -0.1137629821896553, 0.18813075125217438, 0.8012558221817017, 0.2626424729824066, 0.532440185546875, ...
18143	https://en.wikipedia.org/wiki/Lincoln%2C%20New%20Hampshire	Lincoln, New Hampshire	Lincoln is a town in Grafton County, New Hampshire, United States. It is the second-largest town by area in New Hampshire. The population was 1,631 at the 2020 census. The town is home to the New Hampshire Highland Games and to a portion of Franconia Notch State Park. Set in the White Mountains, large portions of the town are within the White Mountain National Forest. The Appalachian Trail crosses the western and northeastern parts of the town. Lincoln is the location of Loon Mountain Ski Resort and associated recreation-centered development. The primary settlement in town, where 969 people resided at the 2020 census, is defined as the Lincoln census-designated place (CDP) and is located along New Hampshire Route 112 east of Interstate 93. The town also includes the former village sites of Stillwater and Zealand (sometimes known as Pullman) in the town's remote eastern and northern sections respectively, which are now within the White Mountain National Forest. History In 1764, colonial Governor Benning Wentworth granted to a group of approximately 70 land investors from Connecticut. Lincoln was named after Henry Fiennes Pelham-Clinton, 2nd Duke of Newcastle, 9th Earl of Lincoln – a cousin of the Wentworth governors. He held the position of comptroller of customs for the port of London under King George II and George III, which was important to trade between America and England. The town was settled about 1782. The 1790 census indicates that it had 22 inhabitants. Rocky soil yielded poor farming, but the area's abundant timber, combined with water power to run sawmills on the Pemigewasset River and its East Branch, helped Lincoln develop into a center for logging. By 1853, the Merrimack River Lumber Company was operating. The railroad transported freight, and increasingly brought tourists to the beautiful mountain region. In 1892, James Everell Henry (1831–1912) bought approximately of virgin timber and established a logging enterprise at what is today the center of Lincoln. In 1902, he built a pulp and paper mill. He erected the Lincoln House hotel in 1903, although a 1907 fire would nearly raze the community. Until he died in 1912, Henry controlled his company town, installing relatives in positions of civic authority. In 1917, Henry's heirs sold the business to the Parker Young Company, which in turn sold it to the Marcalus Manufacturing Company in 1946. Franconia Paper took over in 1950, producing 150 tons of paper a day until bankruptcy in 1971, at which time new river classification standards discouraged further papermaking in Lincoln. Tourism is today the principal business. Nearby Loon Mountain has long drawn skiers, and in recent years has attempted to convert itself into a four-season attraction. The Flume is one of the most visited attractions in the state. Discovered in 1808, it is a natural canyon extending at the base of Mount Liberty. Walls of Conway granite rise to a height of and are only apart. Geography According to the United States Census Bureau, the town has a total area of , of which are land and are water, comprising 0.43% of the town. It is the second-largest town in area in New Hampshire, after Pittsburg. Lincoln is drained by the Pemigewasset River and its East Branch. Lincoln lies almost fully within the Merrimack River watershed, with the western edge of town in the Connecticut River watershed. Kancamagus Pass, elevation , is on the Kancamagus Highway at the eastern boundary. The highest point in Lincoln is the summit of Mount Bond at above sea level. Demographics As of the census of 2010, there were 1,662 people, 794 households, and 439 families residing in the town. There were 2,988 housing units, of which 2,194, or 73.4%, were vacant. 2,083 of the vacant units were for seasonal or recreational use. The racial makeup of the town was 96.9% white, 0.3% African American, 0.1% Native American, 1.7% Asian, 0.0% Native Hawaiian or Pacific Islander, 0.3% some other race, and 0.6% from two or more races. 1.7% of the population were Hispanic or Latino of any race. Of the 794 households, 21.5% had children under the age of 18 living with them, 43.1% were headed by married couples living together, 7.8% had a female householder with no husband present, and 44.7% were non-families. 37.0% of all households were made up of individuals, and 13.4% were someone living alone who was 65 years of age or older. The average household size was 2.09, and the average family size was 2.75. In the town, 18.7% of the population were under the age of 18, 6.8% were from 18 to 24, 19.4% from 25 to 44, 34.8% from 45 to 64, and 20.4% were 65 years of age or older. The median age was 48.5 years. For every 100 females, there were 105.2 males. For every 100 females age 18 and over, there were 103.3 males. For the period 2011-2015, the estimated median annual income for a household was $37,095, and the median income for a family was $55,326. Male full-time workers had a median income of $31,106 versus $27,381 for females. The per capita income for the town was $24,109. 21.0% of the population and 9.1% of families were below the poverty line. 20.2% of the population under the age of 18 and 8.6% of those 65 or older were living in poverty. See also White Mountain art Sites of interest Clark's Bears (formerly Clark's Trading Post) White Mountain Central Railroad Franconia Notch State Park, including: Flume Gorge Lonesome Lake Hobo Railroad Loon Mountain ski resort Whale's Tale Water Park References External links Lincoln Public Library New Hampshire Highland Games New Hampshire Economic and Labor Market Information Bureau Profile Company towns in New Hampshire Logging communities in the United States Populated places established in 1764 Towns in Grafton County, New Hampshire Towns in New Hampshire 1764 establishments in New Hampshire	[ -0.8881860375404358, 0.551517903804779, -0.23138941824436188, -0.13798166811466217, 0.663413405418396, 0.592853307723999, 0.641301155090332, 0.6979572176933289, -0.32001596689224243, -0.6273882985115051, -0.42571142315864563, -0.13147392868995667, -0.07022993266582489, 0.566031813621521, ...
18145	https://en.wikipedia.org/wiki/List%20of%20laser%20applications	List of laser applications	Many scientific, military, medical and commercial laser applications have been developed since the invention of the laser in 1958. The coherency, high monochromaticity, and ability to reach extremely high powers are all properties which allow for these specialized applications. Scientific In science, lasers are used in many ways, including: A wide variety of interferometric techniques Raman spectroscopy Laser induced breakdown spectroscopy Atmospheric remote sensing Investigating nonlinear optics phenomena Holographic techniques employing lasers also contribute to a number of measurement techniques. Laser based lidar (LIght raDAR) technology has application in geology, seismology, remote sensing and atmospheric physics. Lasers have been used aboard spacecraft such as in the Cassini-Huygens mission. In astronomy, lasers have been used to create artificial laser guide stars, used as reference objects for adaptive optics telescopes. Lasers may also be indirectly used in spectroscopy as a micro-sampling system, a technique termed Laser ablation (LA), which is typically applied to ICP-MS apparatus resulting in the powerful LA-ICP-MS. The principles of laser spectroscopy are discussed by Demtröder. Spectroscopy Most types of laser are an inherently pure source of light; they emit near-monochromatic light with a very well defined range of wavelengths. By careful design of the laser components, the purity of the laser light (measured as the "linewidth") can be improved more than the purity of any other light source. This makes the laser a very useful source for spectroscopy. The high intensity of light that can be achieved in a small, well collimated beam can also be used to induce a nonlinear optical effect in a sample, which makes techniques such as Raman spectroscopy possible. Other spectroscopic techniques based on lasers can be used to make extremely sensitive detectors of various molecules, able to measure molecular concentrations in the parts-per-1012 (ppt) level. Due to the high power densities achievable by lasers, beam-induced atomic emission is possible: this technique is termed Laser induced breakdown spectroscopy (LIBS). Heat treatment Heat treating with the lasers allows selective surface hardening against wear with little or no distortion of the component. Because this eliminates much part reworking that is currently done, the laser system's capital cost is recovered in a short time. An inert, absorbent coating for laser heat treatment has also been developed that eliminates the fumes generated by conventional paint coatings during the heat-treating process with CO2 laser beams. One consideration crucial to the success of a heat treatment operation is control of the laser beam irradiance on the part surface. The optimal irradiance distribution is driven by the thermodynamics of the laser-material interaction and by the part geometry. Typically, irradiances between 500-5000 W/cm^2 satisfy the thermodynamic constraints and allow the rapid surface heating and minimal total heat input required. For general heat treatment, a uniform square or rectangular beam is one of the best options. For some special applications or applications where the heat treatment is done on an edge or corner of the part, it may be better to have the irradiance decrease near the edge to prevent melting. Weather Research shows that scientists may one day be able to induce rain and lightning storms (as well as micro-manipulating some other weather phenomena) using high energy lasers. Such a breakthrough could potentially eradicate droughts, help alleviate weather related catastrophes, and allocate weather resources to areas in need. Lunar laser ranging When the Apollo astronauts visited the moon, they planted retroreflector arrays to make possible the Lunar Laser Ranging Experiment. Laser beams are focused through large telescopes on Earth aimed toward the arrays, and the time taken for the beam to be reflected back to Earth measured to determine the distance between the Earth and Moon with high accuracy. Photochemistry Some laser systems, through the process of mode locking, can produce extremely brief pulses of light - as short as picoseconds or femtoseconds (10−12 - 10−15 seconds). Such pulses can be used to initiate and analyze chemical reactions, a technique known as photochemistry. The short pulses can be used to probe the process of the reaction at a very high temporal resolution, allowing the detection of short-lived intermediate molecules. This method is particularly useful in biochemistry, where it is used to analyse details of protein folding and function. Laser scanner Laser barcode scanners are ideal for applications that require high speed reading of linear codes or stacked symbols. Laser cooling A technique that has recent success is laser cooling. This involves atom trapping, a method where a number of atoms are confined in a specially shaped arrangement of electric and magnetic fields. Shining particular wavelengths of light at the ions or atoms slows them down, thus cooling them. As this process is continued, they all are slowed and have the same energy level, forming an unusual arrangement of matter known as a Bose–Einstein condensate. Nuclear fusion Some of the world's most powerful and complex arrangements of multiple lasers and optical amplifiers are used to produce extremely high intensity pulses of light of extremely short duration, e.g. laboratory for laser energetics, National Ignition Facility, GEKKO XII, Nike laser, Laser Mégajoule, HiPER. These pulses are arranged such that they impact pellets of tritium–deuterium simultaneously from all directions, hoping that the squeezing effect of the impacts will induce atomic fusion in the pellets. This technique, known as "inertial confinement fusion", so far has not been able to achieve "breakeven", that is, so far the fusion reaction generates less power than is used to power the lasers, but research continues. Microscopy Confocal laser scanning microscopy and Two-photon excitation microscopy make use of lasers to obtain blur-free images of thick specimens at various depths. Laser capture microdissection use lasers to procure specific cell populations from a tissue section under microscopic visualization. Additional laser microscopy techniques include harmonic microscopy, four-wave mixing microscopy and interferometric microscopy. Military Directly as an energy weapon A laser weapon is directed-energy weapon based on lasers. Defensive countermeasures Defensive countermeasure applications can range from compact, low power infrared countermeasures to high power, airborne laser systems. IR countermeasure systems use lasers to confuse the seeker heads on infrared homing missiles. Disorientation Some weapons simply use a laser to disorient a person. One such weapon is the Thales Green Laser Optical Warner. Guidance Laser guidance is a technique of guiding a missile or other projectile or vehicle to a target by means of a laser beam. Target designator Another military use of lasers is as a laser target designator. This is a low-power laser pointer used to indicate a target for a precision-guided munition, typically launched from an aircraft. The guided munition adjusts its flight-path to home in to the laser light reflected by the target, enabling a great precision in aiming. The beam of the laser target designator is set to a pulse rate that matches that set on the guided munition to ensure munitions strike their designated targets and do not follow other laser beams which may be in use in the area. The laser designator can be shone onto the target by an aircraft or nearby infantry. Lasers used for this purpose are usually infrared lasers, so the enemy cannot easily detect the guiding laser light. Firearms Laser sight The laser has in most firearms applications been used as a tool to enhance the targeting of other weapon systems. For example, a laser sight'' is a small, usually visible-light laser placed on a handgun or a rifle and aligned to emit a beam parallel to the barrel. Since a laser beam has low divergence, the laser light appears as a small spot even at long distances; the user places the spot on the desired target and the barrel of the gun is aligned (but not necessarily allowing for bullet drop, windage, distance between the direction of the beam and the axis of the barrel, and the target mobility while the bullet travels). Most laser sights use a red laser diode. Others use an infrared diode to produce a dot invisible to the naked human eye but detectable with night vision devices. The firearms adaptive target acquisition module LLM01 laser light module combines visible and infrared laser diodes. In the late 1990s, green diode pumped solid state laser (DPSS) laser sights (532 nm) became available. Eye-targeted lasers A non-lethal laser weapon was developed by the U.S. Air Force to temporarily impair an adversary's ability to fire a weapon or to otherwise threaten enemy forces. This unit illuminates an opponent with harmless low-power laser light and can have the effect of dazzling or disorienting the subject or causing them to flee. Several types of dazzlers are now available, and some have been used in combat. There remains the possibility of using lasers to blind, since this requires relatively low power levels and is easily achievable in a man-portable unit. However, most nations regard the deliberate permanent blinding of the enemy as forbidden by the rules of war (see Protocol on Blinding Laser Weapons). Although several nations have developed blinding laser weapons, such as China's ZM-87, none of these are believed to have made it past the prototype stage. In addition to the applications that cross over with military applications, a widely known law enforcement use of lasers is for lidar to measure the speed of vehicles. Holographic weapon sight A holographic weapon sight uses a laser diode to illuminate a hologram of a reticle built into a flat glass optical window of the sight. The user looks through the optical window and sees a cross hair reticle image superimposed at a distance on the field of view. Medical Cosmetic surgery (removing tattoos, scars, stretch marks, sunspots, wrinkles, birthmarks, and hairs): see laser hair removal. Laser types used in dermatology include ruby (694 nm), alexandrite (755 nm), pulsed diode array (810 nm), Nd:YAG (1064 nm), Ho:YAG (2090 nm), and Er:YAG (2940 nm). Eye surgery and refractive surgery Soft tissue surgery: CO2, Er:YAG laser Laser scalpel (General surgery, gynecological, urology, laparoscopic) Photobiomodulation (i.e. laser therapy) "No-Touch" removal of tumors, especially of the brain and spinal cord. In dentistry for caries removal, endodontic/periodontic procedures, tooth whitening, and oral surgery Cancer treatment Burn and surgical scar management: scar contracture CO2 (especially the newer fractionated CO2 lasers), redness and itch (Pulsed Dye laser - PDL), post-inflammatory hyper-pigmentation (Q-switched lasers :Ruby, Alexandrite), burn scar unwanted hair growth and trapped hairs (Ruby, IPL and numerous hair removal lasers) Industrial and commercial Industrial laser applications can be divided into two categories depending on the power of the laser: material processing and micro-material processing. In material processing, lasers with average optical power above 1 kilowatt are used mainly for industrial materials processing applications. Beyond this power threshold there are thermal issues related to the optics that separate these lasers from their lower-power counterparts. Laser systems in the 50-300W range are used primarily for pumping, plastic welding and soldering applications. Lasers above 300W are used in brazing, thin metal welding, and sheet metal cutting applications. The required brightness (as measured in by the beam parameter product) is higher for cutting applications than for brazing and thin metal welding. High power applications, such as hardening, cladding, and deep penetrating welding, require multiple kW of optical power, and are used in a broad range of industrial processes. Micro material processing is a category that includes all laser material processing applications under 1 kilowatt. The use of lasers in Micro Materials Processing has found broad application in the development and manufacturing of screens for smartphones, tablet computers, and LED TVs. A detailed list of industrial and commercial laser applications includes: Laser cutting Laser welding Laser drilling Laser marking Laser cleaning Laser cladding, a surface engineering process applied to mechanical components for reconditioning, repair work or hardfacing Photolithography Optical communications over optical fiber or in free space Laser peening Guidance systems (e.g., ring laser gyroscopes) Laser rangefinder / surveying, Lidar / pollution monitoring, Digital minilabs Barcode readers Laser engraving of printing plate Laser bonding of additive marking materials for decoration and identification, Laser pointers Laser mice Laser accelerometers OLED display manufacturing Holography Bubblegrams Optical tweezers Writing subtitles onto motion picture films. Power beaming, which is a possible solution to transfer energy to the climber of a Space elevator 3D laser scanners for accurate 3D measurement Laser line levels are used in surveying and construction. Lasers are also used for guidance for aircraft. Extensively in both consumer and industrial imaging equipment. In laser printers: gas and diode lasers play a key role in manufacturing high resolution printing plates and in image scanning equipment. Diode lasers are used as a lightswitch in industry, with a laser beam and a receiver which will switch on or off when the beam is interrupted, and because a laser can keep the light intensity over larger distances than a normal light, and is more precise than a normal light it can be used for product detection in automated production. Laser alignment Additive manufacturing Plastic welding Metrology - handheld and robotic laser systems for Aerospace, Automotive and Rail applications To store and retrieve data in optical discs, such as CDs and DVDs Blu-ray Entertainment and recreation Laser lighting displays accompany many music concerts Laser tag Laser harp: a musical instrument were the strings are replaced with laser beams As a light source for digital cinema projectors Surveying and ranging Images See also List of laser articles Non-lethal weapon References External links Coherent.com article on Applications for lasers	[ 0.3398869037628174, 0.5949715375900269, 0.093509741127491, -0.15920770168304443, 0.2863325774669647, 0.04424768313765526, 0.15199227631092072, -0.2213054895401001, -0.6015989184379578, 0.05444944649934769, -0.38392651081085205, 0.6954454779624939, -0.5132555365562439, -0.033149734139442444...
18148	https://en.wikipedia.org/wiki/Left-arm%20orthodox%20spin	Left-arm orthodox spin	Left-arm orthodox spin, Left-arm off spin also known as slow left-arm orthodox spin bowling, is a type of left-arm finger spin bowling in the sport of cricket. Left-arm orthodox spin is bowled by a left-arm bowler using the fingers to spin the ball from right to left of the cricket pitch (from the bowler's perspective). Left arm orthodox spin bowlers generally attempt to drift the ball in the air into a right-handed batsman, and then turn it away from the batsman (towards off-stump) upon landing on the pitch. The drift and turn in the air are attacking techniques. The stock delivery of a left-arm orthodox spin bowler is the left-arm orthodox spinner. The major variations of a left-arm orthodox spin bowler are the topspinner (which turns less and bounces higher in the cricket pitch), the arm ball (which does not turn at all, drifts into a right-handed batsman in the direction of the bowler's arm movement; also called a 'floater') and the left-arm spinner's version of a doosra (which turns the other way). Notable slow left arm orthodox spin bowlers Players listed below have been included as they meet specific criteria which the general cricketing public would recognise as having achieved significant success in the art of left-arm orthodox spin bowling. For example, leading wicket-takers, and inventors of new deliveries. Rangana Herath – 433 Test wickets Daniel Vettori – 362 Test wickets and 305 ODI wickets Derek Underwood – 297 Test wickets Bishan Singh Bedi – 266 Test wickets Ravindra Jadeja – 223 Test wickets and 188 ODI wickets Shakib Al Hasan - 215 Test wickets, 115 T20I wickets and 277 ODI wickets Ravi Shastri – 151 Test wickets Keshav Maharaj - 129 Test Wickets Ashley Giles- 143 Test wickets Taijul Islam- 134 Test wickets Jess Jonassen – 109 WODI wickets and 71 WT20I wickets Sophie Ecclestone - 64 WT20I wickets Ajaz Patel - Only left arm orthodox spinner to take 10 wickets in an innings of a Test Match Monty Panesar- 167 Test wickets Ashton Agar- Highest test score by a number 11 batsman References Cricket terminology Bowling (cricket) Articles containing video clips	[ -0.1533748358488083, -0.6413947343826294, -0.19636711478233337, -0.10900653898715973, -0.4079741835594177, -0.08873853832483292, -0.4660451114177704, 0.37713372707366943, -0.0928841158747673, 0.1496049463748932, 0.37928900122642517, 0.05009891092777252, -0.16133880615234375, 0.183049723505...
18151	https://en.wikipedia.org/wiki/Laser%20construction	Laser construction	A laser is constructed from three principal parts: An energy source (usually referred to as the pump or pump source), A gain medium or laser medium, and Two or more mirrors that form an optical resonator. Pump source The pump source is the part that provides energy to the laser system. Examples of pump sources include electrical discharges, flashlamps, arc lamps, light from another laser, chemical reactions and even explosive devices. The type of pump source used principally depends on the gain medium, and this also determines how the energy is transmitted to the medium. A helium–neon (HeNe) laser uses an electrical discharge in the helium-neon gas mixture, a Nd:YAG laser uses either light focused from a xenon flash lamp or diode lasers, and excimer lasers use a chemical reaction. Gain medium / Laser medium The gain medium is the major determining factor of the wavelength of operation, and other properties, of the laser. Gain media in different materials have linear spectra or wide spectra. Gain media with wide spectra allow tuning of the laser frequency. There are hundreds if not thousands of different gain media in which laser operation has been achieved (see list of laser types for a list of the most important ones). The gain medium is excited by the pump source to produce a population inversion, and it is in the gain medium where spontaneous and stimulated emission of photons takes place, leading to the phenomenon of optical gain, or amplification. Examples of different gain media include: Liquids, such as dye lasers. These are usually organic chemical solvents, such as methanol, ethanol or ethylene glycol, to which are added chemical dyes such as coumarin, rhodamine, and fluorescein. The exact chemical configuration of the dye molecules determines the operation wavelength of the dye laser. Gases, such as carbon dioxide, argon, krypton and mixtures such as helium–neon. These lasers are often pumped by electrical discharge. Solids, such as crystals and glasses. The solid host materials are usually doped with an impurity such as chromium, neodymium, erbium or titanium ions. Typical hosts include YAG (yttrium aluminium garnet), YLF (yttrium lithium fluoride), sapphire (aluminium oxide) and various glasses. Examples of solid-state laser media include Nd:YAG, Ti:sapphire, Cr:sapphire (usually known as ruby), Cr:LiSAF (chromium-doped lithium strontium aluminium fluoride), Er:YLF, Nd:glass, and Er:glass. Solid-state lasers are usually pumped by flashlamps or light from another laser. Semiconductors, a type of solid, crystal with uniform dopant distribution or material with differing dopant levels in which the movement of electrons can cause laser action. Semiconductor lasers are typically very small, and can be pumped with a simple electric current, enabling them to be used in consumer devices such as compact disc players. See laser diode. Optical resonator The optical resonator, or optical cavity, in its simplest form is two parallel mirrors placed around the gain medium, which provide feedback of the light. The mirrors are given optical coatings which determine their reflective properties. Typically, one will be a high reflector, and the other will be a partial reflector. The latter is called the output coupler, because it allows some of the light to leave the cavity to produce the laser's output beam. Light from the medium, produced by spontaneous emission, is reflected by the mirrors back into the medium, where it may be amplified by stimulated emission. The light may reflect from the mirrors and thus pass through the gain medium many hundreds of times before exiting the cavity. In more complex lasers, configurations with four or more mirrors forming the cavity are used. The design and alignment of the mirrors with respect to the medium is crucial for determining the exact operating wavelength and other attributes of the laser system. Other optical devices, such as spinning mirrors, modulators, filters, and absorbers, may be placed within the optical resonator to produce a variety of effects on the laser output, such as altering the wavelength of operation or the production of pulses of laser light. Some lasers do not use an optical cavity, but instead rely on very high optical gain to produce significant amplified spontaneous emission (ASE) without needing feedback of the light back into the gain medium. Such lasers are said to be superluminescent, and emit light with low coherence but high bandwidth. Since they do not use optical feedback, these devices are often not categorized as lasers. See also Injection seeder Mode locking Q-switching List of laser articles References Koechner, Walter (1992). Solid-State Laser Engineering, 3rd ed., Springer-Verlag. External links Sam's Laser FAQ A Practical Guide to Lasers for Experimenters and Hobbyists Construction	[ 0.7126473784446716, 0.4992395043373108, 0.47316399216651917, 0.07223748415708542, 0.18692848086357117, 0.1466842144727707, 0.1356838494539261, -0.3089318871498108, -0.23442012071609497, -0.4582383334636688, -0.6447341442108154, 0.7458155751228333, -0.3870590925216675, 0.250200480222702, ...
18152	https://en.wikipedia.org/wiki/Logical%20conjunction	Logical conjunction	In logic, mathematics and linguistics, And () is the truth-functional operator of logical conjunction; the and of a set of operands is true if and only if all of its operands are true. The logical connective that represents this operator is typically written as or . is true if and only if is true and is true. An operand of a conjunction is a conjunct. Beyond logic, the term "conjunction" also refers to similar concepts in other fields: In natural language, the denotation of expressions such as English "and". In programming languages, the short-circuit and control structure. In set theory, intersection. In lattice theory, logical conjunction (greatest lower bound). In predicate logic, universal quantification. Notation And is usually denoted by an infix operator: in mathematics and logic, it is denoted by , or ; in electronics, ; and in programming languages, &, &&, or and. In Jan Łukasiewicz's prefix notation for logic, the operator is K, for Polish koniunkcja. Definition Logical conjunction is an operation on two logical values, typically the values of two propositions, that produces a value of true if and only if both of its operands are true. The conjunctive identity is true, which is to say that AND-ing an expression with true will never change the value of the expression. In keeping with the concept of vacuous truth, when conjunction is defined as an operator or function of arbitrary arity, the empty conjunction (AND-ing over an empty set of operands) is often defined as having the result true. Truth table The truth table of : Defined by other operators In systems where logical conjunction is not a primitive, it may be defined as or Introduction and elimination rules As a rule of inference, conjunction introduction is a classically valid, simple argument form. The argument form has two premises, A and B. Intuitively, it permits the inference of their conjunction. A, B. Therefore, A and B. or in logical operator notation: Here is an example of an argument that fits the form conjunction introduction: Bob likes apples. Bob likes oranges. Therefore, Bob likes apples and Bob likes oranges. Conjunction elimination is another classically valid, simple argument form. Intuitively, it permits the inference from any conjunction of either element of that conjunction. A and B. Therefore, A. ...or alternatively, A and B. Therefore, B. In logical operator notation: ...or alternatively, Negation Definition A conjunction is proven false by establishing either or . In terms of the object language, this reads This formula can be seen as a special case of when is a false proposition. Other proof strategies If implies , then both as well as prove the conjunction false: In other words, a conjunction can actually be proven false just by knowing about the relation of its conjuncts, and not necessary about their truth values. This formula can be seen as a special case of when is a false proposition. Either of the above are constructively valid proofs by contradiction. Properties commutativity: yes associativity: yes distributivity: with various operations, especially with or idempotency: yes monotonicity: yes truth-preserving: yesWhen all inputs are true, the output is true. falsehood-preserving: yesWhen all inputs are false, the output is false. Walsh spectrum: (1,-1,-1,1) Nonlinearity: 1 (the function is bent) If using binary values for true (1) and false (0), then logical conjunction works exactly like normal arithmetic multiplication. Applications in computer engineering In high-level computer programming and digital electronics, logical conjunction is commonly represented by an infix operator, usually as a keyword such as "AND", an algebraic multiplication, or the ampersand symbol & (sometimes doubled as in &&). Many languages also provide short-circuit control structures corresponding to logical conjunction. Logical conjunction is often used for bitwise operations, where 0 corresponds to false and 1 to true: 0 AND 0 = 0, 0 AND 1 = 0, 1 AND 0 = 0, 1 AND 1 = 1. The operation can also be applied to two binary words viewed as bitstrings of equal length, by taking the bitwise AND of each pair of bits at corresponding positions. For example: 11000110 AND 10100011 = 10000010. This can be used to select part of a bitstring using a bit mask. For example, 10011101 AND 00001000 = 00001000 extracts the fifth bit of an 8-bit bitstring. In computer networking, bit masks are used to derive the network address of a subnet within an existing network from a given IP address, by ANDing the IP address and the subnet mask. Logical conjunction "AND" is also used in SQL operations to form database queries. The Curry–Howard correspondence relates logical conjunction to product types. Set-theoretic correspondence The membership of an element of an intersection set in set theory is defined in terms of a logical conjunction: x ∈ A ∩ B if and only if (x ∈ A) ∧ (x ∈ B). Through this correspondence, set-theoretic intersection shares several properties with logical conjunction, such as associativity, commutativity and idempotence. Natural language As with other notions formalized in mathematical logic, the logical conjunction and is related to, but not the same as, the grammatical conjunction and in natural languages. English "and" has properties not captured by logical conjunction. For example, "and" sometimes implies order having the sense of "then". For example, "They got married and had a child" in common discourse means that the marriage came before the child. The word "and" can also imply a partition of a thing into parts, as "The American flag is red, white, and blue." Here, it is not meant that the flag is at once red, white, and blue, but rather that it has a part of each color. See also And-inverter graph AND gate Bitwise AND Boolean algebra (logic) Boolean algebra topics Boolean conjunctive query Boolean domain Boolean function Boolean-valued function Conjunction elimination De Morgan's laws First-order logic Fréchet inequalities Grammatical conjunction Logical disjunction Logical negation Logical graph Operation Peano–Russell notation Propositional calculus References External links Wolfram MathWorld: Conjunction Conjunction Semantics	[ -0.24449652433395386, 0.307369202375412, -0.3723079264163971, 0.12898261845111847, -0.303558886051178, 0.02285126969218254, 0.20968392491340637, 0.18496844172477722, 0.26288512349128723, -0.2188638150691986, -0.54383385181427, 0.5986489057540894, -0.2156783640384674, -0.033798009157180786,...
18153	https://en.wikipedia.org/wiki/Logical%20connective	Logical connective	In logic, a logical connective (also called a logical operator, sentential connective, or sentential operator) is a logical constant. They can be used to connect logical formulas. For instance in the syntax of propositional logic, the binary connective can be used to join the two atomic formulas and , rendering the complex formula . Common connectives include negation, disjunction, conjunction, and implication. In standard systems of classical logic, these connectives are interpreted as truth functions, though they receive a variety of alternative interpretations in nonclassical logics. Their classical interpretations are similar to the meanings of natural language expressions such as English "not", "or", "and", and "if", but not identical. Discrepancies between natural language connectives and those of classical logic have motivated nonclassical approaches to natural language meaning as well as approaches which pair a classical compositional semantics with a robust pragmatics. A logical connective is similar to, but not equivalent to, a syntax commonly used in programming languages called a conditional operator. Overview In formal languages, truth functions are represented by unambiguous symbols. This allows logical statements to not be understood in an ambiguous way. These symbols are called logical connectives, logical operators, propositional operators, or, in classical logic, truth-functional connectives. For the rules which allow new well-formed formulas to be constructed by joining other well-formed formulas using truth-functional connectives, see well-formed formula. Logical connectives can be used to link zero or more statements, so one can speak about -ary logical connectives. The boolean constants True and False can be thought of as zero-ary operators. Negation is a 1-ary connective, and so on. Common logical connectives List of common logical connectives Commonly used logical connectives include: Negation (not): ¬ , N (prefix), ~ Conjunction (and): ∧ , K (prefix), & , ∙ Disjunction (or): ∨, A (prefix) Material implication (if...then): → , C (prefix), ⇒ , ⊃ Biconditional (if and only if): ↔ , E (prefix), ≡ , = Alternative names for biconditional are iff, xnor, and bi-implication. For example, the meaning of the statements it is raining (denoted by P) and I am indoors (denoted by Q) is transformed, when the two are combined with logical connectives: It is not raining (P) It is raining and I am indoors () It is raining or I am indoors () If it is raining, then I am indoors () If I am indoors, then it is raining () I am indoors if and only if it is raining () It is also common to consider the always true formula and the always false formula to be connective: True formula (⊤, 1, V [prefix], or T) False formula (⊥, 0, O [prefix], or F) History of notations Negation: the symbol ¬ appeared in Heyting in 1929 (compare to Frege's symbol ⫟ in his Begriffsschrift); the symbol ~ appeared in Russell in 1908; an alternative notation is to add a horizontal line on top of the formula, as in ; another alternative notation is to use a prime symbol as in P'. Conjunction: the symbol ∧ appeared in Heyting in 1929 (compare to Peano's use of the set-theoretic notation of intersection ∩); the symbol & appeared at least in Schönfinkel in 1924; the symbol . comes from Boole's interpretation of logic as an elementary algebra. Disjunction: the symbol ∨ appeared in Russell in 1908 (compare to Peano's use of the set-theoretic notation of union ∪); the symbol + is also used, in spite of the ambiguity coming from the fact that the + of ordinary elementary algebra is an exclusive or when interpreted logically in a two-element ring; punctually in the history a + together with a dot in the lower right corner has been used by Peirce,<ref>Peirce (1867) On an improvement in Boole's calculus of logic.</ref> Implication: the symbol → can be seen in Hilbert in 1917; ⊃ was used by Russell in 1908 (compare to Peano's inverted C notation); ⇒ was used in Vax. Biconditional: the symbol ≡ was used at least by Russell in 1908; ↔ was used at least by Tarski in 1940; ⇔ was used in Vax; other symbols appeared punctually in the history, such as ⊃⊂ in Gentzen, ~ in Schönfinkel or ⊂⊃ in Chazal. True: the symbol 1 comes from Boole's interpretation of logic as an elementary algebra over the two-element Boolean algebra; other notations include (to be found in Peano). False: the symbol 0 comes also from Boole's interpretation of logic as a ring; other notations include (to be found in Peano). Some authors used letters for connectives at some time of the history: u. for conjunction (German's "und" for "and") and o. for disjunction (German's "oder" for "or") in earlier works by Hilbert (1904); Np for negation, Kpq for conjunction, Dpq for alternative denial, Apq for disjunction, Xpq for joint denial, Cpq for implication, Epq for biconditional in Łukasiewicz (1929); cf. Polish notation. Redundancy Such a logical connective as converse implication "←" is actually the same as material conditional with swapped arguments; thus, the symbol for converse implication is redundant. In some logical calculi (notably, in classical logic), certain essentially different compound statements are logically equivalent. A less trivial example of a redundancy is the classical equivalence between and . Therefore, a classical-based logical system does not need the conditional operator "→" if "¬" (not) and "∨" (or) are already in use, or may use the "→" only as a syntactic sugar for a compound having one negation and one disjunction. There are sixteen Boolean functions associating the input truth values and with four-digit binary outputs. These correspond to possible choices of binary logical connectives for classical logic. Different implementations of classical logic can choose different functionally complete subsets of connectives. One approach is to choose a minimal set, and define other connectives by some logical form, as in the example with the material conditional above. The following are the minimal functionally complete sets of operators in classical logic whose arities do not exceed 2: One element {↑}, {↓}. Two elements , , , , , , , , , , , , , , , , , . Three elements , , , , , . Another approach is to use with equal rights connectives of a certain convenient and functionally complete, but not minimal set. This approach requires more propositional axioms, and each equivalence between logical forms must be either an axiom or provable as a theorem. The situation, however, is more complicated in intuitionistic logic. Of its five connectives, {∧, ∨, →, ¬, ⊥}, only negation "¬" can be reduced to other connectives (see for more). Neither conjunction, disjunction, nor material conditional has an equivalent form constructed from the other four logical connectives. Natural language The standard logical connectives of classical logic have rough equivalents in the grammars of natural languages. In English, as in many languages, such expressions are typically grammatical conjunctions. However, they can also take the form of complementizers, verb suffixes, and particles. The denotations of natural language connectives is a major topic of research in formal semantics, a field that studies the logical structure of natural languages. The meanings of natural language connectives are not precisely identical to their nearest equivalents in classical logic. In particular, disjunction can receive an exclusive interpretation in many languages. Some researchers have taken this fact as evidence that natural language semantics is nonclassical. However, others maintain classical semantics by positing pragmatic accounts of exclusivity which create the illusion of nonclassicality. In such accounts, exclusivity is typically treated as a scalar implicature. Related puzzles involving disjunction include free choice inferences, Hurford's Constraint, and the contribution of disjunction in alternative questions. Other apparent discrepancies between natural language and classical logic include the paradoxes of material implication, donkey anaphora and the problem of counterfactual conditionals. These phenomena have been taken as motivation for identifying the denotations of natural language conditionals with logical operators including the strict conditional, the variably strict conditional, as well as various dynamic operators. The following table shows the standard classically definable approximations for the English connectives. Properties Some logical connectives possess properties that may be expressed in the theorems containing the connective. Some of those properties that a logical connective may have are: Associativity Within an expression containing two or more of the same associative connectives in a row, the order of the operations does not matter as long as the sequence of the operands is not changed. CommutativityThe operands of the connective may be swapped, preserving logical equivalence to the original expression. Distributivity A connective denoted by · distributes over another connective denoted by +, if for all operands , , . Idempotence Whenever the operands of the operation are the same, the compound is logically equivalent to the operand. Absorption A pair of connectives ∧, ∨ satisfies the absorption law if for all operands , . Monotonicity If f(a1, ..., an) ≤ f(b1, ..., bn) for all a1, ..., an, b1, ..., bn ∈ {0,1} such that a1 ≤ b1, a2 ≤ b2, ..., an ≤ bn. E.g., ∨, ∧, ⊤, ⊥. Affinity Each variable always makes a difference in the truth-value of the operation or it never makes a difference. E.g., ¬, ↔, , ⊤, ⊥. Duality To read the truth-value assignments for the operation from top to bottom on its truth table is the same as taking the complement of reading the table of the same or another connective from bottom to top. Without resorting to truth tables it may be formulated as . E.g., ¬. Truth-preserving The compound all those arguments are tautologies is a tautology itself. E.g., ∨, ∧, ⊤, →, ↔, ⊂ (see validity). Falsehood-preserving The compound all those argument are contradictions is a contradiction itself. E.g., ∨, ∧, , ⊥, ⊄, ⊅ (see validity). Involutivity (for unary connectives) . E.g. negation in classical logic. For classical and intuitionistic logic, the "=" symbol means that corresponding implications "...→..." and "...←..." for logical compounds can be both proved as theorems, and the "≤" symbol means that "...→..." for logical compounds is a consequence of corresponding "...→..." connectives for propositional variables. Some many-valued logics may have incompatible definitions of equivalence and order (entailment). Both conjunction and disjunction are associative, commutative and idempotent in classical logic, most varieties of many-valued logic and intuitionistic logic. The same is true about distributivity of conjunction over disjunction and disjunction over conjunction, as well as for the absorption law. In classical logic and some varieties of many-valued logic, conjunction and disjunction are dual, and negation is self-dual, the latter is also self-dual in intuitionistic logic. Order of precedence As a way of reducing the number of necessary parentheses, one may introduce precedence rules: ¬ has higher precedence than ∧, ∧ higher than ∨, and ∨ higher than →. So for example, is short for . Here is a table that shows a commonly used precedence of logical operators. However, not all compilers use the same order; for instance, an ordering in which disjunction is lower precedence than implication or bi-implication has also been used. Sometimes precedence between conjunction and disjunction is unspecified requiring to provide it explicitly in given formula with parentheses. The order of precedence determines which connective is the "main connective" when interpreting a non-atomic formula. Computer science A truth-functional approach to logical operators is implemented as logic gates in digital circuits. Practically all digital circuits (the major exception is DRAM) are built up from NAND, NOR, NOT, and transmission gates; see more details in Truth function in computer science. Logical operators over bit vectors (corresponding to finite Boolean algebras) are bitwise operations. But not every usage of a logical connective in computer programming has a Boolean semantic. For example, lazy evaluation is sometimes implemented for and , so these connectives are not commutative if either or both of the expressions , have side effects. Also, a conditional, which in some sense corresponds to the material conditional connective, is essentially non-Boolean because for if (P) then Q;, the consequent Q is not executed if the antecedent P is false (although a compound as a whole is successful ≈ "true" in such case). This is closer to intuitionist and constructivist views on the material conditional— rather than to classical logic's views. See also Boolean domain Boolean function Boolean logic Boolean-valued function Four-valued logic List of Boolean algebra topics Logical constant Modal operator Propositional calculus Truth function Truth table Truth values References Sources Bocheński, Józef Maria (1959), A Précis of Mathematical Logic'', translated from the French and German editions by Otto Bird, D. Reidel, Dordrecht, South Holland. . External links Lloyd Humberstone (2010), "Sentence Connectives in Formal Logic", Stanford Encyclopedia of Philosophy (An abstract algebraic logic approach to connectives.) John MacFarlane (2005), "Logical constants", Stanford Encyclopedia of Philosophy. Connective da:Logisk konnektiv	[ -0.27553123235702515, 0.015222840011119843, -0.359276682138443, 0.5227766036987305, -0.29665541648864746, -0.10214721411466599, -0.10898138582706451, 0.33423566818237305, 0.0905180349946022, -0.3223252594470978, -0.3938952386379242, 0.30761563777923584, -0.41836223006248474, 0.484336018562...
18154	https://en.wikipedia.org/wiki/Propositional%20calculus	Propositional calculus	Propositional calculus is a branch of logic. It is also called propositional logic, statement logic, sentential calculus, sentential logic, or sometimes zeroth-order logic. It deals with propositions (which can be true or false) and relations between propositions, including the construction of arguments based on them. Compound propositions are formed by connecting propositions by logical connectives. Propositions that contain no logical connectives are called atomic propositions. Unlike first-order logic, propositional logic does not deal with non-logical objects, predicates about them, or quantifiers. However, all the machinery of propositional logic is included in first-order logic and higher-order logics. In this sense, propositional logic is the foundation of first-order logic and higher-order logic. Explanation Logical connectives are found in natural languages. In English for example, some examples are "and" (conjunction), "or" (disjunction), "not" (negation) and "if" (but only when used to denote material conditional). The following is an example of a very simple inference within the scope of propositional logic: Premise 1: If it's raining then it's cloudy. Premise 2: It's raining. Conclusion: It's cloudy. Both premises and the conclusion are propositions. The premises are taken for granted, and with the application of modus ponens (an inference rule), the conclusion follows. As propositional logic is not concerned with the structure of propositions beyond the point where they can't be decomposed any more by logical connectives, this inference can be restated replacing those atomic statements with statement letters, which are interpreted as variables representing statements: Premise 1: Premise 2: Conclusion: The same can be stated succinctly in the following way: When is interpreted as "It's raining" and as "it's cloudy" the above symbolic expressions can be seen to correspond exactly with the original expression in natural language. Not only that, but they will also correspond with any other inference of this form, which will be valid on the same basis this inference is. Propositional logic may be studied through a formal system in which formulas of a formal language may be interpreted to represent propositions. A system of axioms and inference rules allows certain formulas to be derived. These derived formulas are called theorems and may be interpreted to be true propositions. A constructed sequence of such formulas is known as a derivation or proof and the last formula of the sequence is the theorem. The derivation may be interpreted as proof of the proposition represented by the theorem. When a formal system is used to represent formal logic, only statement letters (usually capital roman letters such as , and ) are represented directly. The natural language propositions that arise when they're interpreted are outside the scope of the system, and the relation between the formal system and its interpretation is likewise outside the formal system itself. In classical truth-functional propositional logic, formulas are interpreted as having precisely one of two possible truth values, the truth value of true or the truth value of false. The principle of bivalence and the law of excluded middle are upheld. Truth-functional propositional logic defined as such and systems isomorphic to it are considered to be zeroth-order logic. However, alternative propositional logics are also possible. For more, see Other logical calculi below. History Although propositional logic (which is interchangeable with propositional calculus) had been hinted by earlier philosophers, it was developed into a formal logic (Stoic logic) by Chrysippus in the 3rd century BC and expanded by his successor Stoics. The logic was focused on propositions. This advancement was different from the traditional syllogistic logic, which was focused on terms. However, most of the original writings were lost and the propositional logic developed by the Stoics was no longer understood later in antiquity. Consequently, the system was essentially reinvented by Peter Abelard in the 12th century. Propositional logic was eventually refined using symbolic logic. The 17th/18th-century mathematician Gottfried Leibniz has been credited with being the founder of symbolic logic for his work with the calculus ratiocinator. Although his work was the first of its kind, it was unknown to the larger logical community. Consequently, many of the advances achieved by Leibniz were recreated by logicians like George Boole and Augustus De Morgan—completely independent of Leibniz. Just as propositional logic can be considered an advancement from the earlier syllogistic logic, Gottlob Frege's predicate logic can be also considered an advancement from the earlier propositional logic. One author describes predicate logic as combining "the distinctive features of syllogistic logic and propositional logic." Consequently, predicate logic ushered in a new era in logic's history; however, advances in propositional logic were still made after Frege, including natural deduction, truth trees and truth tables. Natural deduction was invented by Gerhard Gentzen and Jan Łukasiewicz. Truth trees were invented by Evert Willem Beth. The invention of truth tables, however, is of uncertain attribution. Within works by Frege and Bertrand Russell, are ideas influential to the invention of truth tables. The actual tabular structure (being formatted as a table), itself, is generally credited to either Ludwig Wittgenstein or Emil Post (or both, independently). Besides Frege and Russell, others credited with having ideas preceding truth tables include Philo, Boole, Charles Sanders Peirce, and Ernst Schröder. Others credited with the tabular structure include Jan Łukasiewicz, Alfred North Whitehead, William Stanley Jevons, John Venn, and Clarence Irving Lewis. Ultimately, some have concluded, like John Shosky, that "It is far from clear that any one person should be given the title of 'inventor' of truth-tables.". Terminology In general terms, a calculus is a formal system that consists of a set of syntactic expressions (well-formed formulas), a distinguished subset of these expressions (axioms), plus a set of formal rules that define a specific binary relation, intended to be interpreted as logical equivalence, on the space of expressions. When the formal system is intended to be a logical system, the expressions are meant to be interpreted as statements, and the rules, known to be inference rules, are typically intended to be truth-preserving. In this setting, the rules, which may include axioms, can then be used to derive ("infer") formulas representing true statements—from given formulas representing true statements. The set of axioms may be empty, a nonempty finite set, or a countably infinite set (see axiom schema). A formal grammar recursively defines the expressions and well-formed formulas of the language. In addition a semantics may be given which defines truth and valuations (or interpretations). The language of a propositional calculus consists of a set of primitive symbols, variously referred to as atomic formulas, placeholders, proposition letters, or variables, and a set of operator symbols, variously interpreted as logical operators or logical connectives. A well-formed formula is any atomic formula, or any formula that can be built up from atomic formulas by means of operator symbols according to the rules of the grammar. Mathematicians sometimes distinguish between propositional constants, propositional variables, and schemata. Propositional constants represent some particular proposition, while propositional variables range over the set of all atomic propositions. Schemata, however, range over all propositions. It is common to represent propositional constants by , , and , propositional variables by , , and , and schematic letters are often Greek letters, most often , , and . Basic concepts The following outlines a standard propositional calculus. Many different formulations exist which are all more or less equivalent, but differ in the details of: their language (i.e., the particular collection of primitive symbols and operator symbols), the set of axioms, or distinguished formulas, and the set of inference rules. Any given proposition may be represented with a letter called a 'propositional constant', analogous to representing a number by a letter in mathematics (e.g., ). All propositions require exactly one of two truth-values: true or false. For example, let be the proposition that it is raining outside. This will be true () if it is raining outside, and false otherwise (). We then define truth-functional operators, beginning with negation. represents the negation of , which can be thought of as the denial of . In the example above, expresses that it is not raining outside, or by a more standard reading: "It is not the case that it is raining outside." When is true, is false; and when is false, is true. As a result, always has the same truth-value as . Conjunction is a truth-functional connective which forms a proposition out of two simpler propositions, for example, and . The conjunction of and is written , and expresses that each are true. We read as " and ". For any two propositions, there are four possible assignments of truth values: is true and is true is true and is false is false and is true is false and is false The conjunction of and is true in case 1, and is false otherwise. Where is the proposition that it is raining outside and is the proposition that a cold-front is over Kansas, is true when it is raining outside and there is a cold-front over Kansas. If it is not raining outside, then is false; and if there is no cold-front over Kansas, then is also false. Disjunction resembles conjunction in that it forms a proposition out of two simpler propositions. We write it , and it is read " or ". It expresses that either or is true. Thus, in the cases listed above, the disjunction of with is true in all cases—except case 4. Using the example above, the disjunction expresses that it is either raining outside, or there is a cold front over Kansas. (Note, this use of disjunction is supposed to resemble the use of the English word "or". However, it is most like the English inclusive "or", which can be used to express the truth of at least one of two propositions. It is not like the English exclusive "or", which expresses the truth of exactly one of two propositions. In other words, the exclusive "or" is false when both and are true (case 1). An example of the exclusive or is: You may have a bagel or a pastry, but not both. Often in natural language, given the appropriate context, the addendum "but not both" is omitted—but implied. In mathematics, however, "or" is always inclusive or; if exclusive or is meant it will be specified, possibly by "xor".) Material conditional also joins two simpler propositions, and we write , which is read "if then ". The proposition to the left of the arrow is called the antecedent, and the proposition to the right is called the consequent. (There is no such designation for conjunction or disjunction, since they are commutative operations.) It expresses that is true whenever is true. Thus is true in every case above except case 2, because this is the only case when is true but is not. Using the example, if then expresses that if it is raining outside, then there is a cold-front over Kansas. The material conditional is often confused with physical causation. The material conditional, however, only relates two propositions by their truth-values—which is not the relation of cause and effect. It is contentious in the literature whether the material implication represents logical causation. Biconditional joins two simpler propositions, and we write , which is read " if and only if ". It expresses that and have the same truth-value, and in cases 1 and 4. ' is true if and only if ' is true, and is false otherwise. It is very helpful to look at the truth tables for these different operators, as well as the method of analytic tableaux. Closure under operations Propositional logic is closed under truth-functional connectives. That is to say, for any proposition , is also a proposition. Likewise, for any propositions and , is a proposition, and similarly for disjunction, conditional, and biconditional. This implies that, for instance, is a proposition, and so it can be conjoined with another proposition. In order to represent this, we need to use parentheses to indicate which proposition is conjoined with which. For instance, is not a well-formed formula, because we do not know if we are conjoining with or if we are conjoining with . Thus we must write either to represent the former, or to represent the latter. By evaluating the truth conditions, we see that both expressions have the same truth conditions (will be true in the same cases), and moreover that any proposition formed by arbitrary conjunctions will have the same truth conditions, regardless of the location of the parentheses. This means that conjunction is associative, however, one should not assume that parentheses never serve a purpose. For instance, the sentence does not have the same truth conditions of , so they are different sentences distinguished only by the parentheses. One can verify this by the truth-table method referenced above. Note: For any arbitrary number of propositional constants, we can form a finite number of cases which list their possible truth-values. A simple way to generate this is by truth-tables, in which one writes , , ..., , for any list of propositional constants—that is to say, any list of propositional constants with entries. Below this list, one writes rows, and below one fills in the first half of the rows with true (or T) and the second half with false (or F). Below one fills in one-quarter of the rows with T, then one-quarter with F, then one-quarter with T and the last quarter with F. The next column alternates between true and false for each eighth of the rows, then sixteenths, and so on, until the last propositional constant varies between T and F for each row. This will give a complete listing of cases or truth-value assignments possible for those propositional constants. Argument The propositional calculus then defines an argument to be a list of propositions. A valid argument is a list of propositions, the last of which follows from—or is implied by—the rest. All other arguments are invalid. The simplest valid argument is modus ponens, one instance of which is the following list of propositions: This is a list of three propositions, each line is a proposition, and the last follows from the rest. The first two lines are called premises, and the last line the conclusion. We say that any proposition follows from any set of propositions , if must be true whenever every member of the set is true. In the argument above, for any and , whenever and are true, necessarily is true. Notice that, when is true, we cannot consider cases 3 and 4 (from the truth table). When is true, we cannot consider case 2. This leaves only case 1, in which is also true. Thus is implied by the premises. This generalizes schematically. Thus, where and may be any propositions at all, Other argument forms are convenient, but not necessary. Given a complete set of axioms (see below for one such set), modus ponens is sufficient to prove all other argument forms in propositional logic, thus they may be considered to be a derivative. Note, this is not true of the extension of propositional logic to other logics like first-order logic. First-order logic requires at least one additional rule of inference in order to obtain completeness. The significance of argument in formal logic is that one may obtain new truths from established truths. In the first example above, given the two premises, the truth of is not yet known or stated. After the argument is made, is deduced. In this way, we define a deduction system to be a set of all propositions that may be deduced from another set of propositions. For instance, given the set of propositions , we can define a deduction system, , which is the set of all propositions which follow from . Reiteration is always assumed, so . Also, from the first element of , last element, as well as modus ponens, is a consequence, and so . Because we have not included sufficiently complete axioms, though, nothing else may be deduced. Thus, even though most deduction systems studied in propositional logic are able to deduce , this one is too weak to prove such a proposition. Generic description of a propositional calculus A propositional calculus is a formal system , where: The language of , also known as its set of formulas, well-formed formulas, is inductively defined by the following rules: Base: Any element of the alpha set is a formula of . If are formulas and is in , then is a formula. Closed: Nothing else is a formula of . Repeated applications of these rules permits the construction of complex formulas. For example: By rule 1, is a formula. By rule 2, is a formula. By rule 1, is a formula. By rule 2, is a formula. Example 1. Simple axiom system Let , where , , , are defined as follows: The set , the countably infinite set of symbols that serve to represent logical propositions: The functionally complete set of logical operators (logical connectives and negation) is as follows. Of the three connectives for conjunction, disjunction, and implication (, and ), one can be taken as primitive and the other two can be defined in terms of it and negation (). Alternatively, all of the logical operators may be defined in terms of a sole sufficient operator, such as the Sheffer stroke. The biconditional () can of course be defined in terms of conjunction and implication as . Adopting negation and implication as the two primitive operations of a propositional calculus is tantamount to having the omega set partition as follows: The set (the set of initial points of logical deduction, i.e., logical axioms) is the axiom system proposed by Jan Łukasiewicz, and used as the propositional-calculus part of a Hilbert system. The axioms are all substitution instances of: The set of transformation rules (rules of inference) is the sole rule modus ponens (i.e., from and , infer ). Then is defined as , and is defined as . This system is used in Metamath set.mm formal proof database. Example 2. Natural deduction system Let , where , , , are defined as follows: The alpha set , is a countably infinite set of symbols, for example: The omega set partitions as follows: In the following example of a propositional calculus, the transformation rules are intended to be interpreted as the inference rules of a so-called natural deduction system. The particular system presented here has no initial points, which means that its interpretation for logical applications derives its theorems from an empty axiom set. The set of initial points is empty, that is, . The set of transformation rules, , is described as follows: Our propositional calculus has eleven inference rules. These rules allow us to derive other true formulas given a set of formulas that are assumed to be true. The first ten simply state that we can infer certain well-formed formulas from other well-formed formulas. The last rule however uses hypothetical reasoning in the sense that in the premise of the rule we temporarily assume an (unproven) hypothesis to be part of the set of inferred formulas to see if we can infer a certain other formula. Since the first ten rules don't do this they are usually described as non-hypothetical rules, and the last one as a hypothetical rule. In describing the transformation rules, we may introduce a metalanguage symbol . It is basically a convenient shorthand for saying "infer that". The format is , in which is a (possibly empty) set of formulas called premises, and is a formula called conclusion. The transformation rule means that if every proposition in is a theorem (or has the same truth value as the axioms), then is also a theorem. Note that considering the following rule Conjunction introduction, we will know whenever has more than one formula, we can always safely reduce it into one formula using conjunction. So for short, from that time on we may represent as one formula instead of a set. Another omission for convenience is when is an empty set, in which case may not appear. Negation introduction From and , infer . That is, . Negation elimination From , infer . That is, . Double negation elimination From , infer . That is, . Conjunction introduction From and , infer . That is, . Conjunction elimination From , infer . From , infer . That is, and . Disjunction introduction From , infer . From , infer . That is, and . Disjunction elimination From and and , infer . That is, . Biconditional introduction From and , infer . That is, . Biconditional elimination From , infer . From , infer . That is, and . Modus ponens (conditional elimination) From and , infer . That is, . Conditional proof (conditional introduction) From [accepting allows a proof of ], infer . That is, . Basic and derived argument forms Proofs in propositional calculus One of the main uses of a propositional calculus, when interpreted for logical applications, is to determine relations of logical equivalence between propositional formulas. These relationships are determined by means of the available transformation rules, sequences of which are called derivations or proofs. In the discussion to follow, a proof is presented as a sequence of numbered lines, with each line consisting of a single formula followed by a reason or justification for introducing that formula. Each premise of the argument, that is, an assumption introduced as an hypothesis of the argument, is listed at the beginning of the sequence and is marked as a "premise" in lieu of other justification. The conclusion is listed on the last line. A proof is complete if every line follows from the previous ones by the correct application of a transformation rule. (For a contrasting approach, see proof-trees). Example of a proof in natural deduction system To be shown that . One possible proof of this (which, though valid, happens to contain more steps than are necessary) may be arranged as follows: Interpret as "Assuming , infer ". Read as "Assuming nothing, infer that implies ", or "It is a tautology that implies ", or "It is always true that implies ". Example of a proof in a classical propositional calculus system We now prove the same theorem in the axiomatic system by Jan Łukasiewicz described above, which is an example of a classical propositional calculus systems, or a Hilbert-style deductive system for propositional calculus. The axioms are: (A1) (A2) (A3) And the proof is as follows: (instance of (A1)) (instance of (A2)) (from (1) and (2) by modus ponens) (instance of (A1)) (from (4) and (3) by modus ponens) Soundness and completeness of the rules The crucial properties of this set of rules are that they are sound and complete. Informally this means that the rules are correct and that no other rules are required. These claims can be made more formal as follows. Note that the proofs for the soundness and completeness of the propositional logic are not themselves proofs in propositional logic ; these are theorems in ZFC used as a metatheory to prove properties of propositional logic. We define a truth assignment as a function that maps propositional variables to true or false. Informally such a truth assignment can be understood as the description of a possible state of affairs (or possible world) where certain statements are true and others are not. The semantics of formulas can then be formalized by defining for which "state of affairs" they are considered to be true, which is what is done by the following definition. We define when such a truth assignment satisfies a certain well-formed formula with the following rules: satisfies the propositional variable if and only if satisfies if and only if does not satisfy satisfies if and only if satisfies both and satisfies if and only if satisfies at least one of either or satisfies if and only if it is not the case that satisfies but not satisfies if and only if satisfies both and or satisfies neither one of them With this definition we can now formalize what it means for a formula to be implied by a certain set of formulas. Informally this is true if in all worlds that are possible given the set of formulas the formula also holds. This leads to the following formal definition: We say that a set of well-formed formulas semantically entails (or implies) a certain well-formed formula if all truth assignments that satisfy all the formulas in also satisfy . Finally we define syntactical entailment such that is syntactically entailed by if and only if we can derive it with the inference rules that were presented above in a finite number of steps. This allows us to formulate exactly what it means for the set of inference rules to be sound and complete: Soundness: If the set of well-formed formulas syntactically entails the well-formed formula then semantically entails . Completeness: If the set of well-formed formulas semantically entails the well-formed formula then syntactically entails . For the above set of rules this is indeed the case. Sketch of a soundness proof (For most logical systems, this is the comparatively "simple" direction of proof) Notational conventions: Let be a variable ranging over sets of sentences. Let and range over sentences. For " syntactically entails " we write " proves ". For " semantically entails " we write " implies ". We want to show: (if proves , then implies ). We note that " proves " has an inductive definition, and that gives us the immediate resources for demonstrating claims of the form "If proves , then ...". So our proof proceeds by induction. Notice that Basis Step II can be omitted for natural deduction systems because they have no axioms. When used, Step II involves showing that each of the axioms is a (semantic) logical truth. The Basis steps demonstrate that the simplest provable sentences from are also implied by , for any . (The proof is simple, since the semantic fact that a set implies any of its members, is also trivial.) The Inductive step will systematically cover all the further sentences that might be provable—by considering each case where we might reach a logical conclusion using an inference rule—and shows that if a new sentence is provable, it is also logically implied. (For example, we might have a rule telling us that from "" we can derive " or ". In III.a We assume that if is provable it is implied. We also know that if is provable then " or " is provable. We have to show that then " or " too is implied. We do so by appeal to the semantic definition and the assumption we just made. is provable from , we assume. So it is also implied by . So any semantic valuation making all of true makes true. But any valuation making true makes " or " true, by the defined semantics for "or". So any valuation which makes all of true makes " or " true. So " or " is implied.) Generally, the Inductive step will consist of a lengthy but simple case-by-case analysis of all the rules of inference, showing that each "preserves" semantic implication. By the definition of provability, there are no sentences provable other than by being a member of , an axiom, or following by a rule; so if all of those are semantically implied, the deduction calculus is sound. Sketch of completeness proof (This is usually the much harder direction of proof.) We adopt the same notational conventions as above. We want to show: If implies , then proves . We proceed by contraposition: We show instead that if does not prove then does not imply . If we show that there is a model where does not hold despite being true, then obviously does not imply . The idea is to build such a model out of our very assumption that does not prove . Thus every system that has modus ponens as an inference rule, and proves the following theorems (including substitutions thereof) is complete: p → (¬p → q) (p → q) → ((¬p → q) → q) p → (q → (p → q)) p → (¬q → ¬(p → q)) ¬p → (p → q) p → p p → (q → p) (p → (q → r)) → ((p → q) → (p → r)) The first five are used for the satisfaction of the five conditions in stage III above, and the last three for proving the deduction theorem. Example As an example, it can be shown that as any other tautology, the three axioms of the classical propositional calculus system described earlier can be proven in any system that satisfies the above, namely that has modus ponens as an inference rule, and proves the above eight theorems (including substitutions thereof). Out of the eight theorems, the last two are two of the three axioms; the third axiom, , can be proven as well, as we now show. For the proof we may use the hypothetical syllogism theorem (in the form relevant for this axiomatic system), since it only relies on the two axioms that are already in the above set of eight theorems. The proof then is as follows: (instance of the 7th theorem) (instance of the 7th theorem) (from (1) and (2) by modus ponens) (instance of the hypothetical syllogism theorem) (instance of the 5th theorem) (from (5) and (4) by modus ponens) (instance of the 2nd theorem) (instance of the 7th theorem) (from (7) and (8) by modus ponens) (instance of the 8th theorem) (from (9) and (10) by modus ponens) (from (3) and (11) by modus ponens) (instance of the 8th theorem) (from (12) and (13) by modus ponens) (from (6) and (14) by modus ponens) Verifying completeness for the classical propositional calculus system We now verify that the classical propositional calculus system described earlier can indeed prove the required eight theorems mentioned above. We use several lemmas proven here: (DN1) - Double negation (one direction) (DN2) - Double negation (another direction) (HS1) - one form of Hypothetical syllogism (HS2) - another form of Hypothetical syllogism (TR1) - Transposition (TR2) - another form of transposition. (L1) (L3) We also use the method of the hypothetical syllogism metatheorem as a shorthand for several proof steps. p → (¬p → q) - proof: (instance of (A1)) (instance of (TR1)) (from (1) and (2) using the hypothetical syllogism metatheorem) (instance of (DN1)) (instance of (HS1)) (from (4) and (5) using modus ponens) (from (3) and (6) using the hypothetical syllogism metatheorem) (p → q) → ((¬p → q) → q) - proof: (instance of (HS1)) (instance of (L3)) (instance of (HS1)) (from (2) and (3) by modus ponens) (from (1) and (4) using the hypothetical syllogism metatheorem) (instance of (TR2)) (instance of (HS2)) (from (6) and (7) using modus ponens) (from (5) and (8) using the hypothetical syllogism metatheorem) p → (q → (p → q)) - proof: (instance of (A1)) (instance of (A1)) (from (1) and (2) using modus ponens) p → (¬q → ¬(p → q)) - proof: (instance of (L1)) (instance of (TR1)) (from (1) and (2) using the hypothetical syllogism metatheorem) ¬p → (p → q) - proof: (instance of (A1)) (instance of (A3)) (from (1) and (2) using the hypothetical syllogism metatheorem) p → p - proof given in the proof example above p → (q → p) - axiom (A1) (p → (q → r)) → ((p → q) → (p → r)) - axiom (A2) Another outline for a completeness proof If a formula is a tautology, then there is a truth table for it which shows that each valuation yields the value true for the formula. Consider such a valuation. By mathematical induction on the length of the subformulas, show that the truth or falsity of the subformula follows from the truth or falsity (as appropriate for the valuation) of each propositional variable in the subformula. Then combine the lines of the truth table together two at a time by using "( is true implies ) implies (( is false implies ) implies )". Keep repeating this until all dependencies on propositional variables have been eliminated. The result is that we have proved the given tautology. Since every tautology is provable, the logic is complete. Interpretation of a truth-functional propositional calculus An interpretation of a truth-functional propositional calculus is an assignment to each propositional symbol of of one or the other (but not both) of the truth values truth (T) and falsity (F), and an assignment to the connective symbols of of their usual truth-functional meanings. An interpretation of a truth-functional propositional calculus may also be expressed in terms of truth tables. For distinct propositional symbols there are distinct possible interpretations. For any particular symbol , for example, there are possible interpretations: is assigned T, or is assigned F. For the pair , there are possible interpretations: both are assigned T, both are assigned F, is assigned T and is assigned F, or is assigned F and is assigned T. Since has , that is, denumerably many propositional symbols, there are , and therefore uncountably many distinct possible interpretations of . Interpretation of a sentence of truth-functional propositional logic If and are formulas of and is an interpretation of then the following definitions apply: A sentence of propositional logic is true under an interpretation if assigns the truth value T to that sentence. If a sentence is true under an interpretation, then that interpretation is called a model of that sentence. is false under an interpretation if is not true under . A sentence of propositional logic is logically valid if it is true under every interpretation. means that is logically valid. A sentence of propositional logic is a semantic consequence of a sentence if there is no interpretation under which is true and is false. A sentence of propositional logic is consistent if it is true under at least one interpretation. It is inconsistent if it is not consistent. Some consequences of these definitions: For any given interpretation a given formula is either true or false. No formula is both true and false under the same interpretation. is false for a given interpretation is true for that interpretation; and is true under an interpretation is false under that interpretation. If and are both true under a given interpretation, then is true under that interpretation. If and , then . is true under is not true under . is true under either is not true under or is true under . A sentence of propositional logic is a semantic consequence of a sentence is logically valid, that is, . Alternative calculus It is possible to define another version of propositional calculus, which defines most of the syntax of the logical operators by means of axioms, and which uses only one inference rule. Axioms Let , , and stand for well-formed formulas. (The well-formed formulas themselves would not contain any Greek letters, but only capital Roman letters, connective operators, and parentheses.) Then the axioms are as follows: Axiom may be considered to be a "distributive property of implication with respect to implication." Axioms and correspond to "conjunction elimination". The relation between and reflects the commutativity of the conjunction operator. Axiom corresponds to "conjunction introduction." Axioms and correspond to "disjunction introduction." The relation between and reflects the commutativity of the disjunction operator. Axiom corresponds to "reductio ad absurdum." Axiom says that "anything can be deduced from a contradiction." Axiom is called "tertium non-datur" (Latin: "a third is not given") and reflects the semantic valuation of propositional formulas: a formula can have a truth-value of either true or false. There is no third truth-value, at least not in classical logic. Intuitionistic logicians do not accept the axiom . Inference rule The inference rule is modus ponens: . Meta-inference rule Let a demonstration be represented by a sequence, with hypotheses to the left of the turnstile and the conclusion to the right of the turnstile. Then the deduction theorem can be stated as follows: If the sequence has been demonstrated, then it is also possible to demonstrate the sequence . This deduction theorem (DT) is not itself formulated with propositional calculus: it is not a theorem of propositional calculus, but a theorem about propositional calculus. In this sense, it is a meta-theorem, comparable to theorems about the soundness or completeness of propositional calculus. On the other hand, DT is so useful for simplifying the syntactical proof process that it can be considered and used as another inference rule, accompanying modus ponens. In this sense, DT corresponds to the natural conditional proof inference rule which is part of the first version of propositional calculus introduced in this article. The converse of DT is also valid: If the sequence has been demonstrated, then it is also possible to demonstrate the sequence in fact, the validity of the converse of DT is almost trivial compared to that of DT: If then 1: 2: and from (1) and (2) can be deduced 3: by means of modus ponens, Q.E.D. The converse of DT has powerful implications: it can be used to convert an axiom into an inference rule. For example, the axiom AND-1, can be transformed by means of the converse of the deduction theorem into the inference rule which is conjunction elimination, one of the ten inference rules used in the first version (in this article) of the propositional calculus. Example of a proof The following is an example of a (syntactical) demonstration, involving only axioms and : Prove: (Reflexivity of implication). Proof: Axiom with Axiom with From (1) and (2) by modus ponens. Axiom with From (3) and (4) by modus ponens. Equivalence to equational logics The preceding alternative calculus is an example of a Hilbert-style deduction system. In the case of propositional systems the axioms are terms built with logical connectives and the only inference rule is modus ponens. Equational logic as standardly used informally in high school algebra is a different kind of calculus from Hilbert systems. Its theorems are equations and its inference rules express the properties of equality, namely that it is a congruence on terms that admits substitution. Classical propositional calculus as described above is equivalent to Boolean algebra, while intuitionistic propositional calculus is equivalent to Heyting algebra. The equivalence is shown by translation in each direction of the theorems of the respective systems. Theorems of classical or intuitionistic propositional calculus are translated as equations of Boolean or Heyting algebra respectively. Conversely theorems of Boolean or Heyting algebra are translated as theorems of classical or intuitionistic calculus respectively, for which is a standard abbreviation. In the case of Boolean algebra can also be translated as , but this translation is incorrect intuitionistically. In both Boolean and Heyting algebra, inequality can be used in place of equality. The equality is expressible as a pair of inequalities and . Conversely the inequality is expressible as the equality , or as . The significance of inequality for Hilbert-style systems is that it corresponds to the latter's deduction or entailment symbol . An entailment is translated in the inequality version of the algebraic framework as Conversely the algebraic inequality is translated as the entailment . The difference between implication and inequality or entailment or is that the former is internal to the logic while the latter is external. Internal implication between two terms is another term of the same kind. Entailment as external implication between two terms expresses a metatruth outside the language of the logic, and is considered part of the metalanguage. Even when the logic under study is intuitionistic, entailment is ordinarily understood classically as two-valued: either the left side entails, or is less-or-equal to, the right side, or it is not. Similar but more complex translations to and from algebraic logics are possible for natural deduction systems as described above and for the sequent calculus. The entailments of the latter can be interpreted as two-valued, but a more insightful interpretation is as a set, the elements of which can be understood as abstract proofs organized as the morphisms of a category. In this interpretation the cut rule of the sequent calculus corresponds to composition in the category. Boolean and Heyting algebras enter this picture as special categories having at most one morphism per homset, i.e., one proof per entailment, corresponding to the idea that existence of proofs is all that matters: any proof will do and there is no point in distinguishing them. Graphical calculi It is possible to generalize the definition of a formal language from a set of finite sequences over a finite basis to include many other sets of mathematical structures, so long as they are built up by finitary means from finite materials. What's more, many of these families of formal structures are especially well-suited for use in logic. For example, there are many families of graphs that are close enough analogues of formal languages that the concept of a calculus is quite easily and naturally extended to them. Many species of graphs arise as parse graphs in the syntactic analysis of the corresponding families of text structures. The exigencies of practical computation on formal languages frequently demand that text strings be converted into pointer structure renditions of parse graphs, simply as a matter of checking whether strings are well-formed formulas or not. Once this is done, there are many advantages to be gained from developing the graphical analogue of the calculus on strings. The mapping from strings to parse graphs is called parsing and the inverse mapping from parse graphs to strings is achieved by an operation that is called traversing the graph. Other logical calculi Propositional calculus is about the simplest kind of logical calculus in current use. It can be extended in several ways. (Aristotelian "syllogistic" calculus, which is largely supplanted in modern logic, is in some ways simpler – but in other ways more complex – than propositional calculus.) The most immediate way to develop a more complex logical calculus is to introduce rules that are sensitive to more fine-grained details of the sentences being used. First-order logic (a.k.a. first-order predicate logic) results when the "atomic sentences" of propositional logic are broken up into terms, variables, predicates, and quantifiers, all keeping the rules of propositional logic with some new ones introduced. (For example, from "All dogs are mammals" we may infer "If Rover is a dog then Rover is a mammal".) With the tools of first-order logic it is possible to formulate a number of theories, either with explicit axioms or by rules of inference, that can themselves be treated as logical calculi. Arithmetic is the best known of these; others include set theory and mereology. Second-order logic and other higher-order logics are formal extensions of first-order logic. Thus, it makes sense to refer to propositional logic as "zeroth-order logic", when comparing it with these logics. Modal logic also offers a variety of inferences that cannot be captured in propositional calculus. For example, from "Necessarily " we may infer that . From we may infer "It is possible that ". The translation between modal logics and algebraic logics concerns classical and intuitionistic logics but with the introduction of a unary operator on Boolean or Heyting algebras, different from the Boolean operations, interpreting the possibility modality, and in the case of Heyting algebra a second operator interpreting necessity (for Boolean algebra this is redundant since necessity is the De Morgan dual of possibility). The first operator preserves 0 and disjunction while the second preserves 1 and conjunction. Many-valued logics are those allowing sentences to have values other than true and false. (For example, neither and both are standard "extra values"; "continuum logic" allows each sentence to have any of an infinite number of "degrees of truth" between true and false.) These logics often require calculational devices quite distinct from propositional calculus. When the values form a Boolean algebra (which may have more than two or even infinitely many values), many-valued logic reduces to classical logic; many-valued logics are therefore only of independent interest when the values form an algebra that is not Boolean. Solvers Finding solutions to propositional logic formulas is an NP-complete problem. However, practical methods exist (e.g., DPLL algorithm, 1962; Chaff algorithm, 2001) that are very fast for many useful cases. Recent work has extended the SAT solver algorithms to work with propositions containing arithmetic expressions; these are the SMT solvers. See also Higher logical levels First-order logic Second-order propositional logic Second-order logic Higher-order logic Related topics Boolean algebra (logic) Boolean algebra (structure) Boolean algebra topics Boolean domain Boolean function Boolean-valued function Categorical logic Combinational logic Combinatory logic Conceptual graph Disjunctive syllogism Entitative graph Equational logic Existential graph Frege's propositional calculus Implicational propositional calculus Intuitionistic propositional calculus Jean Buridan Laws of Form List of logic symbols Logical graph Logical NOR Logical value Mathematical logic Operation (mathematics) Paul of Venice Peirce's law Peter of Spain (author) Propositional formula Symmetric difference Tautology (rule of inference) Truth function Truth table Walter Burley William of Sherwood References Further reading Brown, Frank Markham (2003), Boolean Reasoning: The Logic of Boolean Equations, 1st edition, Kluwer Academic Publishers, Norwell, MA. 2nd edition, Dover Publications, Mineola, NY. Chang, C.C. and Keisler, H.J. (1973), Model Theory, North-Holland, Amsterdam, Netherlands. Kohavi, Zvi (1978), Switching and Finite Automata Theory, 1st edition, McGraw–Hill, 1970. 2nd edition, McGraw–Hill, 1978. Korfhage, Robert R. (1974), Discrete Computational Structures, Academic Press, New York, NY. Lambek, J. and Scott, P.J. (1986), Introduction to Higher Order Categorical Logic, Cambridge University Press, Cambridge, UK. Mendelson, Elliot (1964), Introduction to Mathematical Logic, D. Van Nostrand Company. Related works External links Klement, Kevin C. (2006), "Propositional Logic", in James Fieser and Bradley Dowden (eds.), Internet Encyclopedia of Philosophy, Eprint. Formal Predicate Calculus, contains a systematic formal development along the lines of Alternative calculus forall x: an introduction to formal logic, by P.D. Magnus, covers formal semantics and proof theory for sentential logic. Chapter 2 / Propositional Logic from Logic In Action Propositional sequent calculus prover on Project Nayuki. (note: implication can be input in the form !X\|Y, and a sequent can be a single formula prefixed with > and having no commas) Propositional Logic - A Generative Grammar Systems of formal logic Logical calculi Boolean algebra Classical logic Analytic philosophy	[ -0.056656599044799805, 0.1929074227809906, -0.3937712609767914, 0.5509667992591858, -0.27641043066978455, -0.12387876957654953, -0.018102768808603287, 0.6388759016990662, -0.03690221905708313, -0.3227398991584778, -0.636625349521637, 0.6738899946212769, -0.30309855937957764, -0.11854075640...
18155	https://en.wikipedia.org/wiki/Lazy%20evaluation	Lazy evaluation	In programming language theory, lazy evaluation, or call-by-need, is an evaluation strategy which delays the evaluation of an expression until its value is needed (non-strict evaluation) and which also avoids repeated evaluations (sharing). The benefits of lazy evaluation include: The ability to define control flow (structures) as abstractions instead of primitives. The ability to define potentially infinite data structures. This allows for more straightforward implementation of some algorithms. The ability to define partially-defined data structures where some elements are errors. This allows for rapid prototyping. Lazy evaluation is often combined with memoization, as described in Jon Bentley's Writing Efficient Programs. After a function's value is computed for that parameter or set of parameters, the result is stored in a lookup table that is indexed by the values of those parameters; the next time the function is called, the table is consulted to determine whether the result for that combination of parameter values is already available. If so, the stored result is simply returned. If not, the function is evaluated and another entry is added to the lookup table for reuse. Lazy evaluation is difficult to combine with imperative features such as exception handling and input/output, because the order of operations becomes indeterminate. The opposite of lazy evaluation is eager evaluation, sometimes known as strict evaluation. Eager evaluation is the evaluation strategy employed in most programming languages. History Lazy evaluation was introduced for lambda calculus by Christopher Wadsworth and employed by the Plessey System 250 as a critical part of a Lambda-Calculus Meta-Machine, reducing the resolution overhead for access to objects in a capability-limited address space. For programming languages, it was independently introduced by Peter Henderson and James H. Morris and by Daniel P. Friedman and David S. Wise. Applications Delayed evaluation is used particularly in functional programming languages. When using delayed evaluation, an expression is not evaluated as soon as it gets bound to a variable, but when the evaluator is forced to produce the expression's value. That is, a statement such as x = expression; (i.e. the assignment of the result of an expression to a variable) clearly calls for the expression to be evaluated and the result placed in x, but what actually is in x is irrelevant until there is a need for its value via a reference to x in some later expression whose evaluation could itself be deferred, though eventually the rapidly growing tree of dependencies would be pruned to produce some symbol rather than another for the outside world to see. Control structures Lazy evaluation allows control structures to be defined normally, and not as primitives or compile-time techniques. For example one can define if-then-else and short-circuit evaluation operators: ifThenElse True b c = b ifThenElse False b c = c -- or True \|\| b = True False \|\| b = b -- and True && b = b False && b = False These have the usual semantics, i.e. evaluates (a), then if and only if (a) evaluates to true does it evaluate (b), otherwise it evaluates (c). That is, exactly one of (b) or (c) will be evaluated. Similarly for , if the easy part gives True the lots of work expression could be avoided. Finally, when evaluating , if SafeToTry is false there will be no attempt at evaluating the Expression. Conversely, in an eager language the above definition for would evaluate (a), (b), and (c) regardless of the value of (a). This is not the desired behavior, as (b) or (c) may have side effects, take a long time to compute, or throw errors. It is usually possible to introduce user-defined lazy control structures in eager languages as functions, though they may depart from the language's syntax for eager evaluation: Often the involved code bodies need to be wrapped in a function value, so that they are executed only when called. Working with infinite data structures Delayed evaluation has the advantage of being able to create calculable infinite lists without infinite loops or size matters interfering in computation. The actual values are only computed when needed. For example, one could create a function that creates an infinite list (often called a stream) of Fibonacci numbers. The calculation of the n-th Fibonacci number would be merely the extraction of that element from the infinite list, forcing the evaluation of only the first n members of the list. Take for example this trivial program in Haskell: numberFromInfiniteList :: Int -> Int numberFromInfiniteList n = infinity !! n - 1 where infinity = [1..] main = print $ numberFromInfiniteList 4 In the function , the value of is an infinite range, but until an actual value (or more specifically, a specific value at a certain index) is needed, the list is not evaluated, and even then it is only evaluated as needed (that is, until the desired index.) Provided the programmer is careful, the program completes normally. However, certain calculations may result in the program attempting to evaluate an infinite number of elements; for example, requesting the length of the list or trying to sum the elements of the list with a fold operation would result in the program either failing to terminate or running out of memory. As another example, the list of all Fibonacci numbers can be written in the Haskell programming language as: fibs = 0 : 1 : zipWith (+) fibs (tail fibs) In Haskell syntax, ":" prepends an element to a list, tail returns a list without its first element, and zipWith uses a specified function (in this case addition) to combine corresponding elements of two lists to produce a third. List-of-successes pattern Other uses In computer windowing systems, the painting of information to the screen is driven by expose events which drive the display code at the last possible moment. By doing this, windowing systems avoid computing unnecessary display content updates. Another example of laziness in modern computer systems is copy-on-write page allocation or demand paging, where memory is allocated only when a value stored in that memory is changed. Laziness can be useful for high performance scenarios. An example is the Unix mmap function, which provides demand driven loading of pages from disk, so that only those pages actually touched are loaded into memory, and unneeded memory is not allocated. MATLAB implements copy on edit, where arrays which are copied have their actual memory storage replicated only when their content is changed, possibly leading to an out of memory error when updating an element afterwards instead of during the copy operation. Performance The number of beta reductions to reduce a lambda term with call-by-need is no larger than the number needed by call-by-value or call-by-name reduction. And with certain programs the number of steps may be much smaller, for example a specific family of lambda terms using Church numerals take an infinite amount of steps with call-by-value (i.e. never complete), an exponential number of steps with call-by-name, but only a polynomial number with call-by-need. Call-by-need embodies two optimizations - never repeat work (similar to call-by-value), and never perform unnecessary work (similar to call-by-name). Lazy evaluation can also lead to reduction in memory footprint, since values are created when needed. In practice, lazy evaluation may cause significant performance issues compared to eager evaluation. For example, on modern computer architectures, delaying a computation and performing it later is slower than performing it immediately. This can be alleviated through strictness analysis. Lazy evaluation can also introduce memory leaks due to unevaluated expressions. Implementation Some programming languages delay evaluation of expressions by default, and some others provide functions or special syntax to delay evaluation. In Miranda and Haskell, evaluation of function arguments is delayed by default. In many other languages, evaluation can be delayed by explicitly suspending the computation using special syntax (as with Scheme's "delay" and "force" and OCaml's "lazy" and "Lazy.force") or, more generally, by wrapping the expression in a thunk. The object representing such an explicitly delayed evaluation is called a lazy future. Raku uses lazy evaluation of lists, so one can assign infinite lists to variables and use them as arguments to functions, but unlike Haskell and Miranda, Raku does not use lazy evaluation of arithmetic operators and functions by default. Laziness and eagerness Controlling eagerness in lazy languages In lazy programming languages such as Haskell, although the default is to evaluate expressions only when they are demanded, it is possible in some cases to make code more eager—or conversely, to make it more lazy again after it has been made more eager. This can be done by explicitly coding something which forces evaluation (which may make the code more eager) or avoiding such code (which may make the code more lazy). Strict evaluation usually implies eagerness, but they are technically different concepts. However, there is an optimisation implemented in some compilers called strictness analysis, which, in some cases, allows the compiler to infer that a value will always be used. In such cases, this may render the programmer's choice of whether to force that particular value or not, irrelevant, because strictness analysis will force strict evaluation. In Haskell, marking constructor fields strict means that their values will always be demanded immediately. The seq function can also be used to demand a value immediately and then pass it on, which is useful if a constructor field should generally be lazy. However, neither of these techniques implements recursive strictness—for that, a function called deepSeq was invented. Also, pattern matching in Haskell 98 is strict by default, so the ~ qualifier has to be used to make it lazy. Simulating laziness in eager languages Java In Java, lazy evaluation can be done by using objects that have a method to evaluate them when the value is needed. The body of this method must contain the code required to perform this evaluation. Since the introduction of lambda expressions in Java SE8, Java has supported a compact notation for this. The following example generic interface provides a framework for lazy evaluation: interface Lazy<T> { T eval(); } The Lazy interface with its eval() method is equivalent to the Supplier interface with its get() method in the java.util.function library. Each class that implements the Lazy interface must provide an eval method, and instances of the class may carry whatever values the method needs to accomplish lazy evaluation. For example, consider the following code to lazily compute and print 210: Lazy<Integer> a = ()-> 1; for (int i = 1; i <= 10; i++) { final Lazy<Integer> b = a; a = ()-> b.eval() + b.eval(); } System.out.println( "a = " + a.eval() ); In the above, the variable initially refers to a lazy integer object created by the lambda expression ()->1. Evaluating this lambda expression is equivalent to constructing a new instance of an anonymous class that implements Lazy<Integer> with an method returning . Each iteration of the loop links to a new object created by evaluating the lambda expression inside the loop. Each of these objects holds a reference to another lazy object, , and has an method that calls b.eval() twice and returns the sum. The variable is needed here to meet Java's requirement that variables referenced from within a lambda expression be final. This is an inefficient program because this implementation of lazy integers does not memoize the result of previous calls to . It also involves considerable autoboxing and unboxing. What may not be obvious is that, at the end of the loop, the program has constructed a linked list of 11 objects and that all of the actual additions involved in computing the result are done in response to the call to a.eval() on the final line of code. This call recursively traverses the list to perform the necessary additions. We can build a Java class that memoizes a lazy objects as follows: class Memo<T> implements Lazy<T> { private Lazy<T> lazy; // a lazy expression, eval sets it to null private T memo = null; // the memorandum of the previous value public Memo( Lazy<T> lazy ) { // constructor this.lazy = lazy; } public T eval() { if (lazy != null) { memo = lazy.eval(); lazy = null; } return memo; } } This allows the previous example to be rewritten to be far more efficient. Where the original ran in time exponential in the number of iterations, the memoized version runs in linear time: Lazy<Integer> a = ()-> 1; for (int i = 1; i <= 10; i++) { final Lazy<Integer> b = a; a = new Memo<Integer>( ()-> b.eval() + b.eval() ); } System.out.println( "a = " + a.eval() ); Note that Java's lambda expressions are just syntactic sugar. Anything you can write with a lambda expression can be rewritten as a call to construct an instance of an anonymous inner class implementing the interface, and any use of an anonymous inner class can be rewritten using a named inner class, and any named inner class can be moved to the outermost nesting level. JavaScript In JavaScript, lazy evaluation can be simulated by using a generator. For example, the stream of all Fibonacci numbers can be written, using memoization, as: /** * Generator functions return generator objects, which reify lazy evaluation. * @return {!Generator<bigint>} A non-null generator of integers. / function fibonacciNumbers() { let memo = [1n, -1n]; // create the initial state (e.g. a vector of "negafibonacci" numbers) while (true) { // repeat indefinitely memo = [memo[0] + memo[1], memo[0]]; // update the state on each evaluation yield memo[0]; // yield the next value and suspend execution until resumed } } let stream = fibonacciNumbers(); // create a lazy evaluated stream of numbers let first10 = Array.from(new Array(10), () => stream.next().value); // evaluate only the first 10 numbers console.log(first10); // the output is [0n, 1n, 1n, 2n, 3n, 5n, 8n, 13n, 21n, 34n] Python In Python 2.x the range() function computes a list of integers. The entire list is stored in memory when the first assignment statement is evaluated, so this is an example of eager or immediate evaluation: >>> r = range(10) >>> print r [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> print r[3] 3 In Python 3.x the range() function returns a generator which computes elements of the list on demand. Elements are only generated when they are needed (e.g., when print(r[3]) is evaluated in the following example), so this is an example of lazy or deferred evaluation: >>> r = range(10) >>> print(r) range(0, 10) >>> print(r[3]) 3 This change to lazy evaluation saves execution time for large ranges which may never be fully referenced and memory usage for large ranges where only one or a few elements are needed at any time. In Python 2.x is possible to use a function called xrange() which returns an object that generates the numbers in the range on demand. The advantage of xrange is that generated object will always take the same amount of memory. >>> r = xrange(10) >>> print(r) xrange(10) >>> lst = [x for x in r] >>> print(lst) [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] From version 2.2 forward, Python manifests lazy evaluation by implementing iterators (lazy sequences) unlike tuple or list sequences. For instance (Python 2): >>> numbers = range(10) >>> iterator = iter(numbers) >>> print numbers [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] >>> print iterator <listiterator object at 0xf7e8dd4c> >>> print iterator.next() 0 The above example shows that lists are evaluated when called, but in case of iterator, the first element '0' is printed when need arises. .NET Framework In the .NET Framework it is possible to do lazy evaluation using the class System.Lazy<T>. The class can be easily exploited in F# using the lazy keyword, while the force method will force the evaluation. There are also specialized collections like Microsoft.FSharp.Collections.Seq that provide built-in support for lazy evaluation. let fibonacci = Seq.unfold (fun (x, y) -> Some(x, (y, x + y))) (0I,1I) fibonacci \|> Seq.nth 1000 In C# and VB.NET, the class System.Lazy<T> is directly used. public int Sum() { int a = 0; int b = 0; Lazy<int> x = new Lazy<int>(() => a + b); a = 3; b = 5; return x.Value; // returns 8 } Or with a more practical example: // recursive calculation of the n'th fibonacci number public int Fib(int n) { return (n == 1)? 1 : (n == 2)? 1 : Fib(n-1) + Fib(n-2); } public void Main() { Console.WriteLine("Which Fibonacci number do you want to calculate?"); int n = Int32.Parse(Console.ReadLine()); Lazy<int> fib = new Lazy<int>(() => Fib(n)); // function is prepared, but not executed bool execute; if (n > 100) { Console.WriteLine("This can take some time. Do you really want to calculate this large number? [y/n]"); execute = (Console.ReadLine() == "y"); } else execute = true; if (execute) Console.WriteLine(fib.Value); // number is only calculated if needed } Another way is to use the yield keyword: // eager evaluation public IEnumerable<int> Fibonacci(int x) { IList<int> fibs = new List<int>(); int prev = -1; int next = 1; for (int i = 0; i < x; i++) { int sum = prev + next; prev = next; next = sum; fibs.Add(sum); } return fibs; } // lazy evaluation public IEnumerable<int> LazyFibonacci(int x) { int prev = -1; int next = 1; for (int i = 0; i < x; i++) { int sum = prev + next; prev = next; next = sum; yield return sum; } } See also Combinatory logic Currying Dataflow Eager evaluation Functional programming Futures and promises Generator (computer programming) Graph reduction Incremental computing – a related concept whereby computations are only repeated if their inputs change. May be combined with lazy evaluation. Lambda calculus Lazy initialization Look-ahead Non-strict programming language Normal order evaluation Short-circuit evaluation (minimal) References Further reading External links Lazy evaluation macros in Nemerle Lambda calculus in Boost Libraries in C++ language Lazy Evaluation in ANSI C++ by writing code in a style which uses classes to implement function closures. Evaluation strategy Compiler optimizations Implementation of functional programming languages Articles with example Haskell code	[ 0.041574668139219284, 0.18125855922698975, -0.44288370013237, 0.057848770171403885, -0.28886690735816956, -0.09068772196769714, 0.4261752963066101, 0.004390471614897251, 0.23172642290592194, -0.11721513420343399, -0.3984038829803467, 0.8190611004829407, -0.6846715211868286, -0.100765533745...
18156	https://en.wikipedia.org/wiki/Lemuridae	Lemuridae	Lemuridae is a family of strepsirrhine primates native to Madagascar and the Comoros. They are represented by the Lemuriformes in Madagascar with one of the highest concentration of the lemurs. One of five families commonly known as lemurs. These animals were once thought to be the evolutionary predecessors of monkeys and apes, but this is no longer considered correct. They are formally referred to as lemurids. Classification The family Lemuridae contains 21 extant species in five genera. Family Lemuridae Genus Lemur Ring-tailed lemur, Lemur catta Genus Eulemur, true lemursCommon brown lemur, Eulemur fulvusSanford's brown lemur, Eulemur sanfordiWhite-headed lemur, Eulemur albifronsRed lemur, Eulemur rufusRed-fronted lemur, Eulemur rufifronsCollared brown lemur, Eulemur collarisGray-headed lemur, Eulemur cinereicepsBlack lemur, Eulemur macacoBlue-eyed black lemur, Eulemur flavifronsCrowned lemur, Eulemur coronatusRed-bellied lemur, Eulemur rubriventerMongoose lemur, Eulemur mongozGenus Varecia, ruffed lemurs Black-and-white ruffed lemur, Varecia variegataRed ruffed lemur, Varecia rubraGenus Hapalemur, bamboo lemurs Eastern lesser bamboo lemur (a.k.a. gray gentle bamboo lemur), Hapalemur griseusSouthern lesser bamboo lemur, Hapalemur meridionalisWestern lesser bamboo lemur, Hapalemur occidentalisLac Alaotra gentle lemur (a.k.a. bandro), Hapalemur alaotrensisGolden bamboo lemur, Hapalemur aureusGenus ProlemurGreater bamboo lemur, Prolemur simusGenus †Pachylemur†Pachylemur insignis†Pachylemur jullyi'' This family was once broken into two subfamilies, Hapalemurinae (bamboo lemurs and the greater bamboo lemur) and Lemurinae (the rest of the family), but molecular evidence and the similarity of the scent glands have since placed the ring-tailed lemur with the bamboo lemurs and the greater bamboo lemur. Characteristics Lemurids are medium-sized arboreal primates, ranging from 32 to 56 cm in length, excluding the tail, and weighing from 0.7 to 5 kg. They have long, bushy tails and soft, woolly fur of varying coloration. The hindlegs are slightly longer than the forelegs, although not enough to hamper fully quadrupedal movement (unlike the sportive lemurs). Most species are highly agile, and regularly leap several metres between trees. They have a good sense of smell and binocular vision. Unlike most other lemurs, all but one species of lemurid (the ring-tailed lemur) lack a tapetum lucidum, a reflective layer in the eye that improves night vision. Historically among mammals, activity cycles are either strictly diurnal or nocturnal, however, these can widely vary across species. Lemur activity has in general evolved from nocturnal to diurnal. Some lemurs are also cathemeral, an activity pattern where an animal is neither strictly diurnal nor nocturnal. Lemurids are herbivorous, eating fruit, leaves, and, in some cases, nectar. For the most part, they have the dental formula: . A lemur's diet is one that is not restricted since their diet consists of frugivory, granivory, folivory, insectivory, omnivory, and gumnivory foods. Some Subfossil records have contributed to the knowledge of the currently extant lemurs from the Holocene by showing the changes in their dental records in habitats near human activity. This demonstrates that lemur species such as the lemur catta and the common brown lemur were forced to switch their primary diet to a group of secondary food sources. With most lemurids, the mother gives birth to one or two young after a gestation period of between 120 and 140 days, depending on species. The ruffed lemur species are the only lemurids that have true litters, consisting of anywhere from two to six offspring. They are generally sociable animals, living in groups of up to thirty individuals in some species. In some cases, such as the ring-tailed lemur, the groups are long-lasting, with distinct dominance hierarchies, while in others, such as the common brown lemur, the membership of the groups varies from day to day, and seems to have no clear social structure. Some of the lemur traits include low basal metabolic rate, highly seasonal breeders, adaptations to unpredictable climate and female dominance. Female dominance amongst lemurs is when the females are sexually monomorphic and have priority access to food. Lemurs live in groups of 11 to 17 animals, where females tend to stay within their natal groups and the males migrate. Male lemurs are competitive to win their mates which causes instability among the other organisms. Lemurs are able to mark their territory by using scents from local areas. A number of lemur species are considered threatened; two species are critically endangered, one species is endangered, and five species are rated as vulnerable. Habitat The highly seasonal dry deciduous forest of Madagascar alternates between dry and wet seasons, making it uniquely suitable for lemurs. Lemur species diversity increases as the number of tree species in an area increase and is also higher in forests that have been disturbed over undisturbed areas. Evidence from the Subfossil records show that many of the now extinct lemurs actually lived in much drier climates than the currently extant lemurs. References External links Primate families Lemurs Taxa named by John Edward Gray	[ -0.30010661482810974, 0.10147333145141602, -0.6323171257972717, -0.3399207890033722, 0.13711948692798615, 0.9247497916221619, 0.6614848375320435, 0.013662366196513176, -0.979649007320404, -0.21830779314041138, 0.0796712189912796, 0.30645567178726196, -0.8886001110076904, 0.0271712671965360...
18157	https://en.wikipedia.org/wiki/Lucent	Lucent	Lucent Technologies, Inc. was an American multinational telecommunications equipment company headquartered in Murray Hill, New Jersey. It was established on September 30, 1996, through the divestiture of the former AT&T Technologies business unit of AT&T Corporation, which included Western Electric and Bell Labs. Lucent was merged with Alcatel SA of France on December 1, 2006, forming Alcatel-Lucent. Alcatel-Lucent was absorbed by Nokia in January 2016. Name Lucent means "light-bearing" in Latin. The name was applied for in 1996 at the time of the split from AT&T. The name was widely criticised, as the logo was to be, both internally and externally. Corporate communications and business cards included the strapline 'Bell Labs Innovations' in a bid to retain the prestige of the internationally famous research lab, within a new business under an as-yet unknown name. This same linguistic root also gives Lucifer, "the light bearer" (from lux, 'light', and ferre, 'to bear'), who is also a character in Dante's epic poem Inferno. Shortly after the Lucent renaming in 1996, Lucent's Plan 9 project released a development of their work as the Inferno OS in 1997. This extended the 'Lucifer' and Dante references as a series of punning names for the components of Inferno - Dis, Limbo, Charon and Styx (9P Protocol). When the rights to Inferno were sold in 2000, the company Vita Nuova Holdings was formed to represent them. This continues the Dante theme, although moving away from his Divine Comedy to the poem La Vita Nuova. Logo The Lucent logo, the Innovation Ring, was designed by Landor Associates, a prominent San Francisco-based branding consultancy. One source inside Lucent says that the logo is a Zen Buddhist symbol for "eternal truth", the Enso, turned 90 degrees and modified. Another source says it represents the mythic ouroboros, a snake holding its tail in its mouth. Lucent's logo also has been said to represent constant re-creating and re-thinking. Carly Fiorina picked the logo because her mother was a painter and she rejected the sterile geometric logos of most high tech companies. After the logo was compared in the media to the ring a coffee mug leaves on paper, a Dilbert comic strip showed Dogbert as an overpaid consultant designing a new company logo; he takes a piece of paper that his coffee cup was sitting on and calls it the "Brown Ring of Quality". A telecommunication commentator referred to the logo as "a big red zero" and predicted financial losses. History One of the primary reasons AT&T Corporation chose to spin off its equipment manufacturing business was to permit it to profit from sales to competing telecommunications providers; these customers had previously shown reluctance to purchase from a direct competitor. Bell Labs brought prestige to the new company, as well as the revenue from thousands of patents. At the time of its spinoff, Lucent was placed under the leadership of Henry Schacht, who was brought in to oversee its transition from an arm of AT&T into an independent corporation. Richard McGinn, who was serving as President and COO, succeeded Schacht as CEO in 1997 while Schacht remained chairman of the board. Lucent became a "darling" stock of the investment community in the late 1990s, and its split-adjusted spinoff price of $7.56/share rose to a high of $84. Its market capitalization reached a high of $258 billion, and it was at the time the most widely held company with 5.3 million shareholders. In 1997, Lucent acquired Milpitas-based voicemail market leader Octel Communications Corporation for $2.1 billion, a move which immediately rendered the Business Systems Group profitable. By 1999 Lucent stock continued to soar and in that year Lucent acquired Ascend Communications, an Alameda, California–based manufacturer of communications equipment for US$24 billion. Lucent held discussions to acquire Juniper Networks but decided instead to build its own routers. In 1997, Lucent acquired Livingston Enterprises Inc. for $650 million in stock. Livingston was known most for the creation of the RADIUS protocol and their PortMaster product that was used widely by dial-up internet service providers. In 1995, Carly Fiorina led corporate operations. In that capacity, she reported to Lucent chief executive Henry B. Schacht. She played a key role in planning and implementing the 1996 initial public offering of a successful stock and company launch strategy. Under her guidance, the spin-off raised 3 billion. Later in 1996, Fiorina was appointed president of Lucent's consumer products sector, reporting to president and chief operating officer Rich McGinn. In 1997, she was named group president for Lucent's 19 billion global service-provider business, overseeing marketing and sales for the company's largest customer segment. That year, Fiorina chaired a 2.5 billion joint venture between Lucent's consumer communications and Royal Philips Electronics, under the name Philips Consumer Communications (PCC). The focus of the venture was to bring both companies to the top three in technology, distribution, and brand recognition. Ultimately, the project struggled and dissolved a year later after it garnered only 2% market share in mobile phones. Losses were at $500 million on sales of $2.5 billion. As a result of the failed joint venture, Philips announced the closure of one-quarter of the company's 230 factories worldwide, and Lucent closed down its wireless handset portion of the venture. Analysts suggested that the joint venture's failure was due to a combination of technology and management problems. Upon the end of the joint venture, PCC sent 5,000 employees back to Philips, many of which were laid off, and 8,400 employees back to Lucent. Under Fiorina, the company added 22,000 jobs and revenues seemed to grow from 19 billion to 38 billion. However, the real cause of Lucent spurring sales under Fiorina was by lending money to their own customers. According to Fortune magazine, "In a neat bit of accounting magic, money from the loans began to appear on Lucent’s income statement as new revenue while the dicey debt got stashed on its balance sheet as an allegedly solid asset". Lucent's stock price grew 10-fold. At the start of 2000, Lucent's "private bubble" burst, while competitors like Nortel Networks and Alcatel were still going strong; it would be many months before the rest of the telecom industry bubble collapsed. Previously Lucent had 14 straight quarters where it exceeded analysts' expectations, leading to high expectations for the 15th quarter, ending Dec. 31, 1999. On January 6, 2000, Lucent made the first of a string of announcements that it had missed its quarterly estimates, as CEO Rich McGinn grimly announced that Lucent had run into special problems during that quarter—including disruptions in its optical networking business—and reported flat revenues and a big drop in profits. That caused the stock to plunge by 28%, shaving $64 billion off of the company's market capitalization. When it was later revealed that it had used dubious accounting and sales practices to generate some of its earlier quarterly numbers, Lucent fell from grace. It was said that "Rich McGinn couldn't accept Lucent's fall from its early triumphs." He described himself once as imposing "audacious" goals on his managers, believing the stretch for performance would produce dream results. Henry Schacht defended the corporate culture that McGinn created and also noted that McGinn did not sell any Lucent shares while serving as CEO. In November 2000, the company disclosed to the Securities and Exchange Commission that it had a $125 million accounting error for the third quarter of 2000, and by December 2000 it reported it had overstated its revenues for its latest quarter by nearly $700 million. Although no wrongdoing was found on his part, McGinn was forced to resign as CEO and he was replaced by Schacht on an interim basis. Subsequently, its CFO, Deborah Hopkins, left the company in May 2001 with Lucent's stock at $9.06 whereas at the time she was hired it was at $46.82. In 2001 there were merger discussions between Lucent and Alcatel, which would have seen Lucent acquired at its current market price without a premium; the newly combined entity would have been headquartered in Murray Hill. However, these negotiations collapsed when Schacht insisted on an equal 7-7 split of the merged company's board of directors, while Alcatel chief executive officer Serge Tchuruk wanted 8 of the 14 board seats for Alcatel due to it being in a stronger position. The failure of the merger talks caused Lucent's share price to collapse, and by October 2002 the stock price had bottomed at 55 cents per share. Patricia Russo, formerly Lucent's EVP of the Corporate Office who then left for Eastman Kodak to serve as COO, was named permanent Chairman and CEO of Lucent in 2002, succeeding Schacht who remained on the Board of Directors. In April 2000, Lucent sold its Consumer Products unit to VTech and Consumer Phone Services. In October 2000, Lucent spun off its Business Systems arm into Avaya, Inc., and in June 2002, it spun off its microelectronics division into Agere Systems. The spinoffs of enterprise networking and wireless, the industry's key growth businesses from 2003 onward, meant that Lucent no longer had the capacity to serve this market. Lucent was reduced to 30,500 employees, down from about 165,000 employees at its zenith. The layoffs of so many experienced employees meant that the company was in a weakened position and unable to reestablish itself when the market recovered in 2003. By early 2003, Lucent's market value was $15.6 billion (which includes $6.8 billion of current value for two companies that Lucent had recently spun off, Avaya and Agere Systems), making the shares worth around $2.13, a far cry from its dotcom bubble peak of around $84, when Lucent was worth $258 billion. Lucent continued to be active in the areas of telephone switching, optical, data and wireless networking. On April 2, 2006, Lucent announced a merger agreement with Alcatel, which was 1.5 times the size of Lucent. Serge Tchuruk became non-executive chairman, and Russo served as CEO of the newly merged company, Alcatel-Lucent, until they were both forced to resign at the end of 2008. The merger failed to produce the expected synergies, and there were significant write-downs of Lucent's assets that Alcatel purchased. Operations Divisions Lucent was divided into several core groups: Network Solutions Group served landline/cellular telephone service providers by providing equipment and other solutions necessary to provide telephone service, including networking equipment. Lucent Worldwide Services (LWS) provided network services to telecom companies and business; clients included AT&T Corporation and Verizon. Divisions of LWS included the AT&T Customer Business Unit, known as ACBU; and another group for Southwestern Bell and other Bell companies. Both divisions were responsible for the installation of telecom equipment ranging from 2-pair copper to multi-wire fiber optics. Each group also installed the first true national cellular service with LTE speeds in the 1990s. Bell Labs was created in 1925 as the R&D firm of the Bell System. It was an AT&T subsidiary set up as dual ownership by AT&T and Western Electric, the manufacturing arm of AT&T. Murray Hill facility The Murray Hill anechoic chamber, built in 1940, is the world's oldest wedge-based anechoic chamber. The interior room measures approximately high by wide by deep. The exterior concrete and brick walls are about thick to keep outside noise from entering the chamber. The chamber absorbs over 99.995% of the incident acoustic energy above 200 Hz. At one time the Murray Hill chamber was cited in the Guinness Book of World Records as the world's quietest room. It is possible to hear the sounds of skeletal joints and heart beats very prominently. The Murray Hill facility was the global headquarters for Lucent Technologies. The Murray Hill facility also has the largest copper-roof in the world. When Lucent Technologies was experiencing financial troubles in 2000 and 2001, one out of every three fluorescent lights was turned off in the facility. The same was done in the Naperville, Illinois, and Allentown, Pennsylvania, facilities for a while. The facility had a cricket field and featured a nearby station from which enthusiasts could control RC airplanes and helicopters. References Further reading Lazonick, William, and Edward March (2011) "The Rise and Demise of Lucent Technologies," Journal of Strategic Management Education, vol. 7, no. 4., online Telecommunications companies established in 1996 American companies established in 1996 Telecommunications companies disestablished in 2006 Defunct companies based in New Jersey Defunct telecommunications companies of the United States Telecommunications equipment vendors	[ 0.06861225515604019, 0.08974814414978027, 0.1858135461807251, 0.16293497383594513, -0.03487229719758034, 0.3082256019115448, -0.5176767706871033, 0.47722405195236206, 0.2107124924659729, -0.32988211512565613, -0.3142220973968506, 0.25685033202171326, 0.48863545060157776, 0.3928793370723724...
18158	https://en.wikipedia.org/wiki/Lupercalia	Lupercalia	Lupercalia was a pastoral festival of Ancient Rome observed annually on February 15 to purify the city, promoting health and fertility. Lupercalia was also known as dies Februatus, after the purification instruments called februa, the basis for the month named Februarius. Name The festival was originally known as Februa ("Purifications" or "Purgings") after the which was used on the day. It was also known as and gave its name variously, as epithet to Juno Februalis, Februlis, or Februata in her role as patron deity of that month; to a supposed purification deity called Februus; and to February (), the month during which the festival occurred. Ovid connects to an Etruscan word for "purging". Some sources connect the Latin word for fever () with the same idea of purification or purging, due to the "sweating out" commonly associated with fevers. The name Lupercalia was believed in antiquity to evince some connection with the Ancient Greek festival of the Arcadian Lykaia, a wolf festival (, lýkos; ), and the worship of Lycaean Pan, assumed to be a Greek equivalent to Faunus, as instituted by Evander. Justin describes a cult image of "the Lycaean god, whom the Greeks call Pan and the Romans Lupercus", as nude, save for a goatskin girdle. The statue stood in the Lupercal, the cave where tradition held that Romulus and Remus were suckled by the she-wolf (Lupa). The cave lay at the foot of the Palatine Hill, on which Romulus was thought to have founded Rome. The name of the festival most likely derives from lupus, "wolf", though both the etymology and its significance are obscure. Despite Justin's assertion, no deity named "Lupercus" has been identified. Rites Locations The rites were confined to the Lupercal cave, the Palatine Hill, and the Forum, all of which were central locations in Rome's foundation myth. Near the cave stood a sanctuary of Rumina, goddess of breastfeeding; and the wild fig-tree (Ficus Ruminalis) to which Romulus and Remus were brought by the divine intervention of the river-god Tiberinus; some Roman sources name the wild fig tree caprificus, literally "goat fig". Like the cultivated fig, its fruit is pendulous, and the tree exudes a milky sap if cut, which makes it a good candidate for a cult of breastfeeding. Priesthoods The Lupercalia had its own priesthood, the Luperci ("brothers of the wolf"), whose institution and rites were attributed either to the Arcadian culture-hero Evander, or to Romulus and Remus, erstwhile shepherds who had each established a group of followers. The Luperci were young men (iuvenes), usually between the ages of 20 and 40. They formed two religious collegia (associations) based on ancestry; the Quinctiliani (named after the gens Quinctia) and the Fabiani (named after the gens Fabia). Each college was headed by a magister. In 44 BC, a third college, the Juliani, was instituted in honor of Julius Caesar; its first magister was Mark Antony. The college of Juliani disbanded or lapsed following the Assassination of Julius Caesar, and was not re-established in the reforms of his successor, Augustus. In the Imperial era, membership of the two traditional collegia was opened to iuvenes of equestrian status. Sacrifice At the Lupercal altar, a male goat (or goats) and a dog were sacrificed by one or another of the Luperci, under the supervision of the Flamen dialis, Jupiter's chief priest. An offering was also made of salted mealcakes, prepared by the Vestal Virgins. After the blood sacrifice, two Luperci approached the altar. Their foreheads were anointed with blood from the sacrificial knife, then wiped clean with wool soaked in milk, after which they were expected to laugh. The sacrificial feast followed, after which the Luperci cut thongs (known as ) from the flayed skin of the animal, and ran with these, naked or near-naked, along the old Palatine boundary, in an anticlockwise direction around the hill. In Plutarch's description of the Lupercalia, written during the early Empire, ...many of the noble youths and of the magistrates run up and down through the city naked, for sport and laughter striking those they meet with shaggy thongs. And many women of rank also purposely get in their way, and like children at school present their hands to be struck, believing that the pregnant will thus be helped in delivery, and the barren to pregnancy. The Luperci completed their circuit of the Palatine, then returned to the Lupercal cave. History The Februa was of ancient and possibly Sabine origin. After February was added to the Roman calendar, Februa occurred on its fifteenth day (). Of its various rituals, the most important came to be those of the Lupercalia. The Romans themselves attributed the instigation of the Lupercalia to Evander, a culture hero from Arcadia who was credited with bringing the Olympic pantheon, Greek laws and alphabet to Italy, where he founded the city of Pallantium on the future site of Rome, 60 years before the Trojan War. Lupercalia was celebrated in parts of Italy and Gaul; Luperci are attested by inscriptions at Velitrae, Praeneste, Nemausus (modern Nîmes) and elsewhere. The ancient cult of the Hirpi Sorani ("wolves of Soranus", from Sabine hirpus "wolf"), who practiced at Mt. Soracte, north of Rome, had elements in common with the Roman Lupercalia. Descriptions of the Lupercalia festival of 44 BC attest to its continuity; Julius Caesar used it as the backdrop for his public refusal of a golden crown offered to him by Mark Antony. The Lupercal cave was restored or rebuilt by Augustus, and has been speculated to be identical with a grotto discovered in 2007, below the remains of Augustus' residence; according to scholarly consensus, the grotto is a nymphaeum, not the Lupercal. The Lupercalia festival is marked on a calendar of 354 alongside traditional and Christian festivals. Despite the banning in 391 of all non-Christian cults and festivals, the Lupercalia was celebrated by the nominally Christian populace on a regular basis into the reign of the emperor Anastasius. Pope Gelasius I (494–96) claimed that only the "vile rabble" were involved in the festival and sought its forceful abolition; the Roman Senate protested that the Lupercalia was essential to Rome's safety and well-being. This prompted Gelasius' scornful suggestion that "If you assert that this rite has salutary force, celebrate it yourselves in the ancestral fashion; run nude yourselves that you may properly carry out the mockery". There is no contemporary evidence to support the popular notions that Gelasius abolished the Lupercalia, or that he, or any other prelate, replaced it with the Feast of the Purification of the Blessed Virgin Mary. A literary association between the Lupercalia and the romantic elements of Saint Valentine's Day dates back to Chaucer and poetic traditions of courtly love. Legacy Horace's Ode III, 18 alludes to the Lupercalia. The festival or its associated rituals gave its name to the Roman month of February () and thence to the modern month. The Roman god Februus personified both the month and purification, but seems to postdate both. William Shakespeare's play Julius Caesar begins during the Lupercalia. Mark Antony is instructed by Caesar to strike his wife Calpurnia, in the hope that she will be able to conceive. Research published in 2019 suggests that the word Leprechaun derives from Lupercus. In the second season of the Netflix series Chilling Adventures of Sabrina the witches celebrate Lupercalia. Today, the Satanic Temple celebrates Lupercalia among its official holidays. References Citations Bibliography A. M. Franklin, The Lupercalia (doctoral dissertation, 1921, 102pp.) Liebler, Naomi Conn (1988). The Ritual Ground of Julius Caesar. Further reading Beard, Mary; North, John; Price, Simon. Religions of Rome: A History. Cambridge University Press, 1998, vol. 1, limited preview online; search "Lupercalia". Lincoln, Bruce. Authority: Construction and Corrosion. University of Chicago Press, 1994, pp. 43–44 online on Julius Caesar and the politicizing of the Lupercalia; valuable list of sources pp. 182–183. North, John. Roman Religion. The Classical Association, 2000, pp. 47 online and 50 on the problems of interpreting evidence for the Lupercalia. Markus, R.A. The End of Ancient Christianity. Cambridge University Press, 1990, pp. 131–134 online, on the continued celebration of the Lupercalia among "uninhibited Christians" into the 5th century, and the reasons for the "brutal intervention" by Pope Gelasius. Wiseman, T.P. "The Lupercalia". In Remus: A Roman Myth. Cambridge, Cambridge University Press, 1995, pp. 77–88, limited preview online, discussion of the Lupercalia in the context of myth and ritual. Wiseman, T.P. "The God of the Lupercal", in Idem, Unwritten Rome. Exeter, University of Exeter Press, 2008. External links William Smith, Dictionary of Greek and Roman Antiquities, 1875: Lupercalia Ancient Roman festivals February observances Wolves in folklore, religion and mythology She-wolf (Roman mythology)	[ 0.06746140122413635, -0.4743060767650604, 0.20804078876972198, -0.05004817992448807, -0.5555105209350586, 0.9506790041923523, 0.04686906188726425, 1.146531105041504, -0.2698856294155121, 0.14610590040683746, 0.3598225712776184, 0.2595086395740509, -0.14446942508220673, 0.5756649374961853, ...
18162	https://en.wikipedia.org/wiki/Lists%20of%20atheists	Lists of atheists	Atheism is, in a broad sense, the lack of belief in the existence of deities. In a narrower sense, atheism is simply the absence of belief that any deities exist. This is a compilation of the various lists of atheists with articles on Wikipedia by category. Living persons in these lists are people whose atheism is relevant to their notable activities or public life, and who have publicly identified themselves as atheists. Lists by country, territory, or people List of atheist Americans List of atheist Armenians List of Dutch atheists List of Jewish atheists and agnostics List of South African atheists Lists by profession List of atheist activists and educators List of atheist authors List of atheist philosophers List of atheists in film, radio, television and theater List of atheists in music List of atheists in politics and law List of atheists in science and technology List of atheists (miscellaneous) Lists by surname List of atheists (surnames A to B) List of atheists (surnames C to D) List of atheists (surnames E to G) List of atheists (surnames H to K) List of atheists (surnames L to M) List of atheists (surnames N to Q) List of atheists (surnames R to S) List of atheists (surnames T to Z) See also List of nonreligious Nobel laureates List of fictitious atheists and agnostics Lists of people by belief (including non-beliefs) List of agnostics List of converts to nontheism List of deists List of former atheists and agnostics List of humanists List of Jewish atheists and agnostics List of pantheists List of secularist organizations Lists about skepticism	[ 0.9880390763282776, 0.8850190043449402, -0.3339850604534149, 0.03892636299133301, -1.154170036315918, 0.0029406738467514515, 1.1030075550079346, 0.48166829347610474, -0.46306195855140686, 0.18943877518177032, -0.004555693827569485, 0.1422717422246933, -0.624854564666748, 0.1163703128695488...
18163	https://en.wikipedia.org/wiki/List%20of%20Buddhists	List of Buddhists	This is a list of notable Buddhists, encompassing all the major branches of the religion (i.e. in Buddhism), and including interdenominational and eclectic Buddhist practitioners. This list includes both formal teachers of Buddhism, and people notable in other areas who are publicly Buddhist or who have espoused Buddhism. Philosophers and founders of schools Individuals are grouped by nationality, except in cases where their influence was felt elsewhere. Gautama Buddha and his immediate disciples ('Buddhists') are listed separately from later Indian Buddhist thinkers, teachers and contemplatives. Buddha's disciples and early Buddhists Gautama Buddha, Siddhārtha Gautama Clergy Ānanda, the Buddha's cousin, personal attendant of the Buddha and a chief disciple Aṅgulimāla, serial killer who attained to sainthood after renouncing wickedness Anuruddhā, one of the ten principal disciples Aśvajit, one of the first five disciples of the Buddha Bharika, one of the first five disciples of the Buddha Devadatta, another cousin of Siddhārtha and later rival who attempted to assassinate the Buddha Gavāṃpati Gayākāśyapa Kālodayin Maha Kapphina Kātyāyana, foremost in explaining the Dharma Kaundinya (also known as Kondañña or Ājñātakauṇḍinya), the first arhat and one of the first five disciples of the Buddha Khemā, a chief of the women disciples Kisā Gautamī Koṣṭhila Mahākāśyapa Mahākauṣṭhila, foremost in eloquence Mahānāman, one of the first five disciples of the Buddha Mahāprajāpatī Gautamī, Buddha's aunt and foster mother, as well as the first woman to be ordained Maudgalyāyana, one of two chief disciples of the Buddha Nanda, younger half-brother of the Buddha Nandika Nadīkāśyapa Paṭācārā Pilindavatsa Piṇḍola Bhāradvāja Pūrṇamaitrāyaṇīputra, one of the ten principal disciples Rāhula, son of Siddhārtha and Yasodharā Revata Śāriputra one of two chief disciples of the Buddha Subhūti, one of the ten principal disciples Śuddhipanthakena Suvāhu Sundarī Nandā, the Buddha's half-sister Sunīta, a low-caste man who reached enlightenment Upāli, foremost disciple in knowledge of the Vinaya Utpalavarṇā Uruvilvākāśyapa Vāgīśa Vakkula Vāṣpa, one of the first five disciples of the Buddha Yasodharā, Siddhārtha's wife before he renounced the palace life Laity Amrapali, royal courtesan Anathapindika, wealthy merchant and banker Ajatasattu, king of Magadha, son of Bimbisāra Bimbisāra, king of Magadha Chandaka, prince Siddhārtha's charioteer Citta, wealthy merchant Cunda Kammāraputta, a smith who gave the Buddha his last meal Hastaka Āṭavika, saved by the Buddha from a demon Kubjottarā, a chief woman disciple and servant of Queen Śyāmāvatī Pasenadi, King of Kosala Samavati, a queen of Kauśāmbī Śuddhodana, the Buddha's father Velukantakiyā Viśākhā, an aristocratic woman and chief female patron Later Indian Buddhists (after Buddha) Aryadeva, foremost disciple of Nagarjuna, continued the philosophical school of Madhyamaka Aśvaghoṣa, Sarvāstivāda Buddhist philosopher, dramatist, poet and orator from India Atiśa, holder of the "mind training" teachings, considered an indirect founder of the Gelug school of Tibetan Buddhism Bhāviveka, early expositor of the Svatantrika branch of the Madhyamaka school Bodhidharma, founder of Chan Buddhism Bodhiruci, patriarch of the Dilun (Chinese:地論) school Batuo, founding abbot and patriarch of the Shaolin Monastery Buddhaghosa, Theravadin commentator Buddhapālita, early expositor of the Prasaṅgika branch of the Madhyamaka school Chandragomin, renowned grammarian Candrakīrti, considered the greatest exponent of Prasaṅgika Dharmakirti, famed logician, author of the Seven Treatises; student of Dignāga's student, Īśvārasēna; said to have debated famed Hindu scholar Adi Shankara Dignāga, famed logician Kamalaśīla (8th century), author of important texts on meditation Kumārajīva, Buddhist monk, scholar, missionary and translator from the Kingdom of Kucha, Central Asia Luipa, one of the eighty-four tantric Mahasiddhas Nagarjuna, founder of the Madhyamaka school, widely considered the most important Mahayana philosopher (with Asanga) Nadapada (Tib. Naropa), Tilopa's primary disciple, teacher of Marpa the Translator and Khungpo Nyaljor Saraha, famed mahasiddha, forefather of the Kagyu lineage Śāntarakṣita, abbot of Nalanda, founder of the Yogacara who helped Padmasambhava establish Buddhism in Tibet Shantideva (8th century), author of the Bodhisattvacaryāvatāra Śīlabhadra, Buddhist monk and philosopher and erstwhile abbot of Nālandā university in India Tilopa, recipient of four separate transmissions from Nagarjuna, Nagpopa, Luipa, and Khandro Kalpa Zangmo; Naropa's teacher From Gandhara Asanga, founder of the Yogacara school, widely considered the most important Mahayana philosopher along with Nagarjuna Garab Dorje, Indian founder of Dzogchen (Great Perfection) tradition Vasubandhu, author of the Abhidharmakōśa and various Yogacara treatises; these may or may not be the same person Padmasambhava (Tib. Guru Rinpoche), Indian founder of Tibetan Buddhism Indo-Greek Dharmaraksita (3rd century BCE), Greek Buddhist missionary sent by emperor Ashoka, and a teacher of the monk Nagasena Mahadharmaraksita (2nd century BCE), Greek Buddhist master during the time of Menander Nāgasena (2nd century BCE), Buddhist sage questioned about Buddhism by Milinda, the Indo-Greek king in the Milinda Pañha Central Asian An Shigao, Parthian monk and the first known Buddhist missionary to China, in 148 CE Dharmarakṣa, Yuezhi monk, the first known translator of the Lotus Sutra into Chinese Jñānagupta (561–592), monk and translator from Gandhara, Pakistan Kumārajīva (c. 401), Kuchan monk and one of the most important translators Lokaksema, Kushan monk from Gandhara, first translator of Mahayana scriptures into Chinese, around 180 CE Prajñā (c. 810), monk and translator from Gandhara, who translated important texts into Chinese and educated the Japanese Kūkai in Sanskrit texts Chinese Baizhang Huaihai, Zen buddhist master of Tang dynasty Bodhidharma, first patriarch of Chan Buddhism in China Dahui Zonggao, 12th-century kōan master Daman Hongren, fifth patriarch of Chan Buddhism in China Dayi Daoxin, fourth patriarch of Chan Buddhism in China Dazu Huike, second patriarch of Chan Buddhism in China Faxian, translator and pilgrim Fazang, was the third of the five patriarchs of the Huayan school of Mahayana Buddhism, of which he is traditionally considered the founder. Guifeng Zongmi, fifth patriarch of the Huayan school Hong Yi, calligraphist, painter, master of seal carving Huangbo Xiyun, 9th-century teacher of Linji Yixuan Huineng, sixth and last patriarch of Chan Buddhism in China Ingen, 17th-century Chinese Chan monk, founder of the Ōbaku sect of Zen Ji Gong, a Buddhist monk revered as a deity in Taoism Jizang, founder of East Asian Mādhyamaka Jnanayasas, translator Linji Yixuan, 9th-century Chinese monk, founder of the Linji school of Chan Buddhism Mazu Daoyi, 8th-century Chan master Moheyan, 8th-century Chinese monk, advocate of "sudden" enlightenment Sanghapala, 6th-century monk (Mon-Khmer?) who translated many texts to Chinese Sengcan, third patriarch of Chan Buddhism in China Wumen Huikai, author of the Gateless Gate Xuanzang, brought Yogacara to China to found the East Asian Yogācāra school; significant pilgrim, translator Xueting Fuyu, 13th-century Shaolin Monastery abbot of the Caodong school Yijing, pilgrim and translator Yunmen Wenyan, founder of one of the five schools of Chan Buddhism Yuquan Shenxiu, Tang dynasty, patriarch of "Northern School" sect of Chan Buddhism Zhaozhou, 9th-century Chan master; noted for "Mu" koan Zhiyi, founder of the Tiantai school Tibetan Gampopa, student of Jetsun Milarepa and founder of the Karma Kagyu lineage of Tibetan Buddhism Jigten Sumgön, founder of Drikung Kagyu Lineage Dolpopa Sherab Gyaltsen, founder of the Jonang school and advocate of the shentong philosophy Longchenpa, one of the greatest Nyingma philosophers Mandarava, important female student and consort of Padmasambhava Marpa Lotsawa, student of Naropa and a founder of the Kagyu lineage of Tibetan Buddhism Milarepa, foremost student of Marpa Lotsawa Padmasambhava, Gandharan founder of Nyingma school of Tibetan Buddhism Karmapa, the founder of Karma Kagyu or Kamtsang Kagyu lineage of Tibetan Buddhism Jamgon Kongtrul, Tibetan buddhist scholar,artist, physician and polymath Sakya Pandita, one of the greatest Sakya philosophers Taranatha, important Jonang scholar Je Tsongkhapa, 14th-century Tibetan monk, founder of the Gelug school of Tibetan Buddhism, based upon the Kadam Yeshe Tsogyal, important female student and consort of Padmasambhava Rongzom Mahapandita, important Nyingma scholar and meditation master of Nyingma lineage of Tibetan Buddhism Japanese Bankei Yōtaku (1622–1693), Zen master of the Rinzai school Dōgen Zenji (1200–1253), founder of the Sōtō school of Zen, based upon the Caodong school Eisai (1141–1215), travelled to China and returned to found the Rinzai school of Zen] Hakuin Ekaku (1686–1769), Rinzai school of Zen] Hōnen (1133–1212), founder of the Jōdo-shū school of Pure Land Buddhism Ikkyū (1374–1481), Zen Buddhist monk and poet Ippen (1234–1289), founder of the Ji-shū sect of Pure Land Buddhism Kūkai (774–835), founder of Shingon Buddhism Myōe (1173–1232), monk of Kegon and Shingon Buddhism, known for his propagation of the Mantra of Light Nakahara Nantenbō (1839–1925), Zen master and artist Nichiren (1222–1282), founder of Nichiren Buddhism Nikkō (1246–1333), founder of Nichiren Shōshū Rōben (689–773), invited Simsang to Japan and founded the Kegon tradition based upon the Korean Hwaeom school Ryōkan (1758–1831), Zen monk and poet Saichō (767–822), founded Tendai school in Japan, also known by the posthumous title Dengyō Daishi Shinran (1173–1263), founder of the Jōdo Shinshū school of Pure Land Buddhism and disciple of Hōnen Takuan Sōhō (1573–1645), Zen teacher, and, according to legend, mentor of the swordsman Miyamoto Musashi Gempō Yamamoto (1866–1961), Zen master Shinjō Itō (1906–1989), founder of Shinnyo-en Korean Gihwa (1376–1433), Korean Seon monk; wrote commentaries on the Diamond Sutra and Sutra of Perfect Enlightenment Jinul, Korean Seon monk (1158–1210); founder of modern Korean gong'an meditation system Uisang (7th century), Korean monk, founder of Hwaeom tradition, based upon the Chinese Huayan school Woncheuk Wonhyo (617–668), Korean monk; prolific commentator on Mahayana sutras Burmese Shin Arahan, primate of Pagan Kingdom, 1056–1115 Ledi Sayadaw, propagator of Vipassanā Mahasi Sayadaw, propagator of Vipassanā Sayadaw U Tejaniya, propagator of Vipassanā Mogok Sayadaw, propagator of Vipassanā Webu Sayadaw, propagator of Vipassanā Panditarama Sayadaw, propagator of Vipassanā Mingun Sayadaw, first monk in Myanmar to be awarded the title of Tipitakadhara, meaning Keeper and Guardian of the Tipitaka Taunggwin Sayadaw, the last Buddhist monk to hold the office as Thathanabaing of Burma Maha Bodhi Ta Htaung Sayadaw, founder of Maha Bodhi Tahtaung Thamanya Sayadaw, best known for his doctrinal emphasis on metta Sunlun Sayadaw, a popular meditation teacher among the monks and Vipassanā meditation master Sitagu Sayadaw, founder and Supreme Head of the Sitagu Buddhist Academies Ashin Nandamalabhivamsa, rector of International Theravada Buddhist Missionary University Chanmyay Sayadaw, well-known monk and editor of the Buddhist Scriptures in Pali for reciting Buddhist scriptures at the Sixth Buddhist Council in Myanmar Taung Galay Sayadaw, Karen Theravadin Buddhist monk, and also known as a prolific writer and a historian Sayadaw U Narada, planted many thousands of Bodhi trees, built thousands of pagodas and Buddha statues Sayadaw U Pannavamsa, prominent Buddhist monk, known for his missionary work, particularly in Sri Lanka and Malaysia Ashin Sandadika, well-known monk Sayagyi U Ba Khin, propagator of vipassana meditation in the Ledi tradition Thai Somdet Phra Buddhacarya (1788–1872), monk who was the preceptor and teacher of King Rama IV Ajahn Sao Kantasīlo (1861–1941), one of the pioneers of the Dhammayuttika Nikaya, mentor of Ajahn Mun Ajahn Mun Bhūridatta (1870–1949), monk who established the Thai Forest Tradition or "Kammaṭṭhāna tradition" Khruba Siwichai (1878–1939), best known for the building of many temples during his time, his charismatic and personalistic character Luang Pu Sodh Candasaro (1884–1959), monk who founded the Dhammakaya Movement in the early 20th century Luang Pu Waen Suciṇṇo (1887–1985), first generation student of the Thai Forest Tradition Somdet Phra Sangharaja Chao Krommaluang Jinavajiralongkorn (1897–1988), the 18th Supreme Patriarch of Thailand Phra Ajaan Thate Desaransi (1902–1994), first generation student of the Thai Forest Tradition and one of the founding teachers of the lineage Buddhādasa Bhikkhu (1906–1993), famous and influential Thai ascetic-philosopher of the 20th century Ajahn Lee Dhammadharo (1907–1961), regarded as one of the great teacher and meditation master of the Thai Forest Tradition Ajahn Maha Bua (1913–2011), well-known monk in the Thai Forest Tradition Somdet Phra Sangharaja Chao Krommaluang Vajirañāṇasaṃvara (1913–2013), the 19th Supreme Patriarch of Thailand Ajahn Fuang Jotiko (1915–1986), student of Ajahn Lee, well-known monk in the Thai Forest Tradition Ajahn Chah (1918–1992), monk well known for his students from all over the world Ajahn Suwat Suvaco (1919–2002), student of Ajahn Funn and established four monasteries in the United States Phra Chanda Thawaro (1922–2012), student of Ajahn Mun, one of the best known Thai Buddhist monks of the late 20th and early 21st centuries Somdet Phra Ariyavongsagatanana IX (1927–), the 20th and current Supreme Patriarch of Thailand, practitioner of the Thai Forest Tradition Rulers and monarchs Anawrahta (1015–1078), founder of the Pagan Kingdom and credited with introducing Theravada Buddhism there and reintroducing it in Ceylon Ashoka (304–232 BC), Mauryan Emperor of ancient India, and the first Buddhist ruler to send Buddhist missionaries outside of India throughout the Old World (阿育王) Brihadratha Maurya, last ruler of the Maurya Empire Bayinnaung Kyawhtin Nawrahta (1516-1581), king of the Toungoo Dynasty, assembled the largest empire in the history of Southeast Asia, viewed himself as the protector of Theravada Buddhism, and had long tried to promote and protect the religion in Ceylon, introduced more orthodox Theravada Buddhism to Upper Burma and the Shan states, prohibited all human and animal sacrifices throughout the kingdom Harsha (606–648), Indian emperor who converted to Buddhism Jayavarman VII (1181–1219), king of Cambodia Kanishka the Great, ruler of the Kushan Empire Kublai Khan, Mongol khagan and founder of the Yuan dynasty of China Hulagu Khan, Mongol ruler who conquered much of Southwest Asia, he converted to Buddhism on his deathbed, spending most of his life as a Nestorian Christian Menander I (Pali: Milinda), 2nd century BCE, a king of the Indo-Greek Kingdom of Northwestern India who questioned Nāgasena about Buddhism in the Milinda Pañha and is said to have become an arhat Mindon Min (1808–1878), penultimate King of Burma and facilitator of the Fifth Buddhist council Emperor Ming of Han Mongkut, king of Thailand and founder of the Dhammayuttika Nikaya Prince Shōtoku (574–622), mythologized crown prince and regent of Japan Theodorus (1st century BCE), Indo-Greek governor, author of a Buddhist dedication Wu Zetian (625–705), only female Empress Regnant in Chinese history Emperor Wu of Liang (梁武帝) (502–549) Devanampiya Tissa of Anuradhapura (307 BCE–267 BCE), King of Anuradhapura Dutugamunu of Anuradhapura (161 BCE-131 BCE), King of Sri Lanka Bimbisar (544-492 BC) founder of Haryanka dynasty Ajatshatru (492 460 BC ) second emperor of Haryanka dynasty Udayin (460-444 BC) third emperor of Haryanka dynasty Pasenadi king of kosala Mahinda Rajapaksa Prime minister of Sri Lanka and Modern Day leader of Buddhist’s World Modern teachers Theravada teachers Ajahn Amaro (1956–) Ajahn Buddhadasa Bhikkhu (1906–1993) Ajahn Brahm (1951–) Ajahn Candasiri (1947–) Ajahn Chah (1918–1992) Ajahn Jayasaro (1958–) Ajahn Khemadhammo (1944–) Ajahn Mun Bhuridatta (1870–1949) Ajahn Pasanno (1949–) Ajahn Sucitto (1949–) Ajahn Sumedho (1934–) Ajahn Sundara (1946–) Ajahn Viradhammo (1947–) Ayya Khema (1923–1997) Balangoda Ananda Maitreya Thero (1896–1998) Bhante Sujato (1966–) Bhikkhu Anālayo (1962–) Bhikkhu Bodhi (1944–) Bhikkhu Kiribathgoda Gnanananda (1961–) Bour Kry (1945–) Charles Henry Allan Bennett (1872–1923) Dipa Ma (1911–1989) Godwin Samararatne (1932–2000) Hammalawa Saddhatissa (1914–1990) Henepola Gunaratana (1927–) Jack Kornfield (1945–) K. L. Dhammajoti (1949–) K. Sri Dhammananda (1919–2006) Kirinde Sri Dhammaratana (1948–) Ledi Sayadaw (1846–1923) Luangpor Thong (1939–) Mahasi Sayadaw (1904–1982) Mother Sayamagyi (1925–2017) Ñāṇamoli Bhikkhu (1905–1960) Nyānaponika Mahāthera (1901–1994) Nyānatiloka Mahāthera (1878–1957) Ñāṇavīra Thera (1920–1965) Narada Maha Thera Phra Paisal Visalo Piyadassi Maha Thera Preah Maha Ghosananda (1929–2007) Sayagyi U Ba Khin (1899–1971) S. N. Goenka (1924–2013) Sharon Salzberg (1952–) Sujiva (1951–) Thanissaro Bhikkhu (1949–) Yuttadhammo Bhikkhu (1979–) In Thailand, Ajahn means monk teachers (have to been a monk more than 10-years) For Theravada, Bhikkhu (male) and Bhikkhuni (female) mean monastic members in Pali (Theravada use Pali language for studying Tripitaka) Tibetan Buddhist teachers Anagarika Govinda (1898–1985) B. Alan Wallace (1950–) Chagdud Tulku Rinpoche (1930–2002) Chögyam Trungpa Rinpoche (1940–1987) Chökyi Nyima Rinpoche (1951–) Dhardo Rimpoche (1917–1990) Dilgo Khyentse (1910–1991) Dudjom Jigdral Yeshe Dorje (1904–1987) Gyaincain Norbu, the 11th Panchen Lama (controversial; born 1990) Kalu Rinpoche (1905–1989) Karma Thinley Rinpoche (1931–) Kelsang Gyatso Matthieu Ricard (1946–) Ole Nydahl (1941–) Rangjung Rigpe Dorje, 16th Karmapa (1924–1981) Sakyong Mipham 14th Dalai Lama (1935–) Tenzin Palmo (1943–) Thubten Yeshe (known as Lama Yeshe) (1935–1984), Tibetan lama who, while exiled in Nepal, co-founded Kopan Monastery (1969) and the Foundation for the Preservation of the Mahayana Tradition (1975). He followed the Gelug tradition. Thubten Zopa Rinpoche Trijang Lobsang Yeshe Tenzin Gyatso(1901–1981) Tsoknyi Rinpoche (1966–) Tulku Urgyen Rinpoche (1920–1996), Dzogchen, Mahamudra and the Chokling Tersar Yongey Mingyur Rinpoche (1975–) Gelek Rimpoche Tsem Tulku Rinpoche (1965–) Dagyab Kyabgoen Rinpoche Yongey Mingyur Rinpoche Sakya Trizin Thubten Chodron Pema Chödrön Robina Courtin Robert Thurman Mark Epstein Dzogchen and Bon Teachers Namkhai Norbu (1938–2018) Tenzin Wangyal Rinpoche (1961–) Zen teachers American Adyashanti Robert Baker Aitken (1917–2010) Anne Hopkins Aitken (1911–1994) Reb Anderson (1943–) Zentatsu Richard Baker (1936–) Joko Beck (1917–2011) Sherry Chayat (1943–) Issan Dorsey (1933–1990) Zoketsu Norman Fischer (1946–) James Ishmael Ford (1948–) Tetsugen Bernard Glassman (1939–2018) Paul Haller Cheri Huber (1944) Sozui Schubert (1965) hvzc.org Soenghyang (Barbara Rhodes, 1948–) Philip Kapleau (1912–2004) Houn Jiyu-Kennett (1924–1996) Bodhin Kjolhede (1948–) Jakusho Kwong (1935–) Taigen Dan Leighton (1950–) John Daido Loori (1931–2009) Dai Bai Zan Cho Bo Zen Ji (1954–) Heng Sure (1949–) Bonnie Myotai Treace (1956–) Brad Warner (1964–) Chinese Fayun (1933–2003) Hsu Yun (1840–1959) Hsuan Hua (1918–1995) Nan Huai-Chin (1918–2012) European John Crook (1930–2011) U Dhammaloka (1856?–1914?) John Garrie (1923–1998) Muhō Noelke (1968–) Japanese Kōbun Chino Otogawa (1938–2002) Taisen Deshimaru (1914–1982) Hakuin Ekaku (1686–1769) Keido Fukushima Jakushitsu Genkō (1290–1367) Shodo Harada (1940–) Harada Daiun Sogaku (1871–1961) Dainin Katagiri (1928–1990) Musō Soseki (1275–1351) Imakita Kosen (1816–1892) Yamada Koun (1907–1989) Taizan Maezumi (1931–1995) Sōyū Matsuoka (?–1998) Sōkō Morinaga (1925–1995) Soen Nakagawa (1907–1984) Gudō Wafu Nishijima (1919–2014) Shōhaku Okumura Kōdō Sawaki (1880–1965) Nyogen Senzaki (1876–1958) Oda Sessō (1901–1966) Soyen Shaku (1859–1919) Zenkei Shibayama (1894–1974) Eido Tai Shimano (1932–2018) Omori Sogen (1904–1994) D. T. Suzuki (1870–1966) Shunryū Suzuki (1904–1971) Dai Bai Zan Cho Bo Zen Ji (1933–) Bassui Tokushō (1327–1387) Sesshū Tōyō (1420–1506) Sobin Yamada Hakuun Yasutani (1885–1973) Bankei Yōtaku (1622–1693) Sesson Yūbai (1290–1348) Korean Seongcheol (1912–1993) Seungsahn (1927–2004) Pomnyun (1953–) Malaysian Chi Chern (1955–) Taiwanese Guang Qin (廣欽) (1892–1986), founder of Cheng Tian Temple (承天禪寺) in Taiwan Yin Shun (印順) (1906–2005), founder of Humanistic Buddhism (人間佛教) Sheng-yen (聖嚴) (1931–2009), founder of Dharma Drum Mountain (法鼓山) in Taiwan Cheng Yen (證嚴) (1937–), founder of Tzu Chi Foundation (慈濟基金會) in Taiwan Hsing Yun (星雲) (1927–), founder of Fo Guang Shan (佛光山) in Taiwan Wei Chueh (惟覺) (1928–), founder of Chung Tai Shan (中台禪寺) in Taiwan Vietnamese Thích Nhất Hạnh (1926–2022) Thích Chân Không (1938–) Thích Thiên-Ân (1926–1980) Thích Thanh Từ (1924–) Writers Nyanatiloka Mahathera, (1878–1957), translated several important Theravadin Pali texts into German, also wrote a Pali grammar, an anthology, and a Buddhist dictionary Nyanaponika Thera (1901–1994), co-founder of the Buddhist Publication Society, contemporary author of numerous seminal Theravada books Ñāṇamoli Bhikkhu (1905–1960), is remembered for his reliable translations from the Pali into English, remarkable command of the Pali language and a wide knowledge of the canonical scriptures Bhikkhu Bodhi (1944–), second president of the Buddhist Publication Society and has edited and authored several publications grounded in the Theravada Buddhist tradition Ṭhānissaro Bhikkhu (1949–), known for his translations of almost 1000 Sutta in all and providing the majority of the sutta translations in a website known as "Access to Insight" Bhikkhu Analayo (1962–), known for his comparative studies of Early Buddhist Texts as preserved by the various early Buddhist traditions Buddhādasa Bhikkhu, his works literally take up an entire room in the National Library of Thailand, and inspired a group of Thai social activists and artists of the 20th century Jack Kornfield (1945–), American book writer, student of renowned forest monk Ajahn Chah, and teacher of Theravada Buddhism Joseph Goldstein (1944–), one of the first American Vipassana teachers, contemporary author of numerous popular books on Buddhism Ven. K. Sri Dhammananda (1919–2006), Buddhist monk and scholar. in Malaysia, wrote approximately 60 Buddhist works, ranging from small pamphlets to texts of over 700 pages Achan Sobin S. Namto (1931–), taught Vipassana meditation and Buddhist psychology in Southeast Asia and North America for over 50 years Phra Dhammavisuddhikavi (1936–), Ex-Vice Rector for Academic Affairs at Mahamakut Buddhist University and has written 70 books on Buddhism P.A. Payutto (1937–), lectured and written extensively about a variety of topics related to Buddhism, awarded the 1994 UNESCO Prize for Peace Education Phra Paisal Visalo, writing and editing books on environment and Buddhism, co-founder of Sekiyadhamma, a network of socially engaged monks in Thailand Yuttadhammo Bhikkhu, (1979–), facilitates a meditation website for groups and individuals, maintains a YouTube channel where hosts both live chatrooms and pre-recorded videos answering viewers' questions about Theravada Buddhism Tara Brach (1953–) John Crook (1930–2011), British ecologist, sociologist, and practitioner of both Ch'an and Tibetan Buddhism tradition Josei Toda (1900–1958), peace activist and second president of the Soka Gakkai Han Yong-un (1879–1944) Chittadhar Hridaya (1906–1982) Hsuan Hua (1918–1995), Tripitaka Master; extensive English commentaries on the major Mahayana Sutras: Avatamsaka Sutra, Shurangama Sutra, Shurangama Mantra, Lotus Sutra, Diamond Sutra, and many others Christmas Humphreys (1901–1983) Daisaku Ikeda (1928–), prolific writer of Nichiren Buddhism, society, peace and nuclear abolition, and President of the Soka Gakkai International Sangharakshita (1925–2018) Edward Salim Michael (1921—2006) Nakamura Hajime (1911–1999) Nishida Kitaro (1870–1945) Gudo Wafu Nishijima (1919–2014) Nishitani Keiji (1900–1990) Henry Steel Olcott (1832–1907), major revivalist of Buddhism in Sri Lanka and a Buddhist modernist for his efforts in interpreting Buddhism through a Westernized len Shunryū Suzuki (1904–1971), Sōtō Zen monk and teacher who helped popularize Zen Buddhism in the United States Sharon Salzberg (1953–), teacher of Buddhist meditation practices in the West, and also a New York Times Best selling author Sheng-yen (1930–2009), religious scholar, one of the most respected teachers of Chinese Ch'an (Zen) Buddhism, and founder of spiritual and educational organization Dharma Drum Mountain Taixu (1890–1947), activist and thinker who advocated the reform and renewal of Chinese Buddhism Yin Shun (1906–2005), bring forth the ideal of "Humanistic" (human-realm) Buddhism and regenerated the interests in the long-ignored Āgamas among Chinese Buddhists Tanaka Chigaku (1861–1939) Tsunesaburo Makiguchi (1871–1944), Japanese educator and founder of the Soka Gakkai Robert Thurman (1941–), American author, editor and translator of books on Tibetan Buddhism, Je Tsongkhapa professor of Indo-Tibetan Buddhist Studies at Columbia University and co-founder and president of Tibet House U.S. Brad Warner (1964–) Alan Watts (1915–1973) Robert Wright (1957–) Noah Levine (1971–) is an American Buddhist teacher and the author Politicians and activists Indian B. R. Ambedkar (1891–1956), Indian nationalist, jurist, scholar, political leader, anthropologist, economist and architect of the Constitution of India Prakash(Balasaheb) Ambedkar, Indian Politician, Grandson of Dr. Babasaheb Ambedkar Kiren Rijiju, Indian politician Ramdas Athawale, Indian politician Udit Raj, is an Indian politician and member of Indian National Congress. Raj, a Dalit, converted from Hinduism to Buddhism in 2001. Malaysian Tan Cheng Lock (1883-1960), Malaysian nationalist, businessmen and founder of Malaysian Chinese Association, key figure in the independence of Malaysia. Burmese Aung San Suu Kyi, Burmese opposition politician and chairperson of the National League for Democracy (NLD) in Burma; received the Rafto Prize and the Sakharov Prize in 1990 and the Nobel Peace Prize in 1991 (Theravada) U Thant (1909–1974), Burmese diplomat and third Secretary-General of the United Nations (1961–1971) (Theravada) U Nu (1997 - 1995), Prime Minister of Burma and facilitator of Sixth Buddhist Council American Bill Clinton, 42nd U.S. president from (1993-2001) David Ige is an american politician. He is the 8th Governor of Hawaii. A Democrat, he served in the Hawaii State Senate from 2003 to 2014 and the Hawaii House of Representatives from 1985 to 2003. In the 2014 gubernatorial election, he defeated incumbent Governor Neil Abercrombie in the Democratic primary, and won the general election over Republican nominee Duke Aiona. Ige was reelected in 2018. Colleen Hanabusa, U.S. Congresswoman (2011–), Democrat and lawyer from Hawaii Mazie Hirono, U.S. Senator (2013–), U.S. Congresswoman (2007–2013) and Democrat from Hawaii; first elected female Senator from Hawaii, first Asian-American woman elected to the Senate, first U.S. Senator born in Japan and the nation's first Buddhist Senator Hank Johnson, U.S. Congressman (2007–) and Democrat from Georgia; one of the first two Buddhists to serve in the United States Congress (Soka Gakkai International) English Eric Lubbock, 4th Baron Avebury (1928–2016), English politician and Liberal Democrat; served as the Liberal Member of Parliament for Orpington from 1962 to 1970 and served in the House of Lords, having inherited the title of Baron Avebury in 1971 (Secular Buddhism) South Korean Jiyul, a Buddhist nun from South Korea who fasted to stop destruction of Korean salamander lands (Korean Seon) Pomnyun, South Korean Buddhist monk, Zen master, and peace activist who received the Ramon Magsaysay Award for Peace and International Understanding in 2002 for his peace activism on the issue of Korean peninsula. (Korean Seon) Vietnamese Thích Huyền Quang (1919–2008), Vietnamese Buddhist monk, dissident and activist; formerly the patriarch of the Unified Buddhist Sangha of Vietnam; in 2002, he was awarded the Homo Homini Award for his human rights activism by the Czech group People in Need Thích Quảng Độ, Vietnamese Buddhist monk, current patriarch of the Unified Buddhist Sangha of Vietnam; awarded the Homo Homini Award for human rights activism by the Czech group People in Need in 2002; nine-time Nobel Peace Prize nominee Thích Quảng Đức (1897–1963), Vietnamese Mahayana monk and self-martyr for freedom of religion; burned himself to death at a busy Saigon road intersection on 11 June 1963 (Mahayana) Sri Lankan D. S. Senanayake (1883-1952), Prime Minister of Ceylon S. W. R. D. Bandaranaike (1899-1959), Prime Minister of Ceylon Sirimavo Bandaranaike (1916-2000), Prime Minister of Sri Lanka and first female Prime Minister in the world. Actors American Anthony Lee, (1981-2000), was an American Buddhist actor and playwright. (Soka Gakkai International) Keanu Reeves (1964- ), American- Canadian Actor and became Lord Buddha in Little Buddha (1993) and Neo in The Matrix film series . (Theravada) Robert Downey Junior (1965-), American jewish buddhist who is well-known as Iron Man. He has said many times that Buddhism has helped him with his drug and alcohol addiction.He was honored by Time Magazine's "Time 100" in 2008, an annual list of the 100 most influential people in the world. His laurels include two Academy Award nominations, three Golden Globe wins, numerous other award nominations and wins, and tremendous popular and commercial success, particularly in his roles as Sherlock Holmes and Tony Stark (the latter of which he has so far played in Iron Man (2008), Iron Man 2 (2010), The Avengers (2012), Iron Man 3 (2013), and Avengers: Age of Ultron (2015). For three consecutive years, from 2012 to 2015, Downey has topped the Forbes list of Hollywood's highest-paid actors, making an estimated $80 million in earnings between June 2014 and June 2015.(Theravada) Ron Glass (1945-2016), is an american devout buddhist actor and comedian. Steven Seagal, American actor and aikido expert (Tibetan Buddhism) Chris Evans (1981- ), is an American buddhist actor. He is well-known as Captain America. He is a student of Indian Buddism. He spent three weeks in Rishikesh in 2005 or 2006 at a Buddhist retreat and that he attends a Buddhism class in LA.(Theravada) Pattrick Duffy (1949- ), is an American actor and director widely known for his role on the CBS primetime soap opera Dallas, where he played Bobby Ewing, the youngest son of Miss Ellie, and the nicest brother of J.R. Ewing from 1978 to 1985 and from 1986 to 1991. The actor was brought closer to the teachings of Buddhism by his late wife, the ballet dancer Carlyn Rosser (1939-2017). He has now been practicing religion for almost 50 years and describes it as an "Essential part" of his life. (Soka Gakkai International) Peter Coyote (1941–), American actor and author Jeff Bridges (1949- ), is an American actor. One of the most acclaimed actors of his generation, he is the recipient of numerous accolades, including a Screen Actors Guild Award, two Golden Globe Awards, and an Academy Award from seven nominations. Critic Pauline Kael wrote that Bridges "May be the most natural and least self-conscious screen actor that has ever lived." The actor elaborated that his Buddhism is more like a general calmness. (Zen) Michael Imperioli (1966- ), is an American actor, writer, director and musician, best known for his role as Christopher Moltisanti in the HBO crime drama The Sopranos (1999–2007), which earned him the Primetime Emmy Award for Outstanding Supporting Actor in a Drama Series in 2004. In 2008, Imperioli became a Buddhist. John Astin is an American actor best known for playing Gomez Addams on The Addams Family Martin Starr (1983- ), is an American Buddhist actor and comedian. He is known for the television roles of Bill Haverchuck on the short-lived comedy-drama Freaks and Geeks (1999–2000), Roman De Beers on the comedy series Party Down (2009–2010), Bertram Gilfoyle on the HBO series Silicon Valley (2014–2019), for his film roles in Knocked Up (2007) and Adventureland (2009), and as Roger Harrington in the Marvel Cinematic Universe films The Incredible Hulk (2008), Spider-Man: Homecoming (2017), Spider-Man: Far From Home (2019), and Spider-Man: No Way Home (2021). (Theravada) David Labrava is an actor, writer, tattoo artist, former member of the Hells Angels, and motorcycle enthusiast best known for playing Happy Lowman in the FX series Sons of Anarchy and its spinoff Mayans M.C.(Zen) Garry Shandling (1949-2016), was an american actor and comedian. (Zen) Drew Carey, is an american buddhist actor, comedian, game show host and photographer.(Theravada) British Adewale Akinnuoye-Agbaje (1967 ) British-Nigerian actor best known for his roles on television, including Lost, Oz, and Game of Thrones (Soka Gakkai International) Benedict Cumberbatch (1976- ) is a British buddhist actor.He is famous for Dr.Strange (2021), The Imitation Game (2014) and Spider-man:No Way Home (2021).(Theravada). Chris Gascoyne (1968-) is an english buddhist actor, who is known for his role as the seventh Peter Barlow in the soap opera Coronation Street from 2000 . Gascoyne has been nominated for several accolades at the British Soap Awards for his portrayal of Peter Barlow.(Theravada) Orlando Bloom (1977- ), English actor. Well-known for Will turner in Pirates of the Carrebean flim series, Elf Legolas in Lord of Rings movie series. (Soka Gakkai International) Peter Dean (1939-), is a British buddhist actor.Best known for his roles as Pete Beale in EastEnders, Jeff Bateman in Coronation Street and Sergeant Jack Wilding in Woodentop (Zen) Russell Brand (1975- ), is a british comedian, actor, and radio host. After beginning his career as a comedian and later becoming an MTV presenter, Brand first achieved renown in 2004 as the host of Big Brother's Big Mouth, and Big Brother spin-off.(Tibetan Buddhism) Indian Gagan Malik (1976- ), Indian actor.(Theravada) Tusshar Kapoor (1976- ), Most celebrated Bollywood actor and producer of India. He is famous for Golmal flim series. ( Nichiren Buddhism) Ayushman Khurrana (1984- ), is an Indian flim actor and activists. Ayushmann Khurrana and his wife Tahira Kashyap are followers of Nichiren Buddhism, which has provided the fuel to fight their battles against cancer. Buddhism has also helped Khurrana articulate his journey as an actor better. “I practice Nichren Buddhism. It has taught me that you have to be mentally strong. It has an impact on your physical being. It (cancer) was a minor frustration for me. But I accepted it truly. I decided that I will not live in denial and hide it from the world,” says Tahira, who was detected with DCIS (ductal carcinoma in situ) with high grade malignant cells last year. ( Niciren Buddhism) Ravi Dubey (1983- ), is an indian buddhist actor,model and producer. He is a Nichiren Buddhist. He said, "I started following Buddhism when I was going through a very rough patch in my life and I wanted some understanding of the chaos that was going on in one's life. I wanted to align myself and feel better about myself. So, when things went out of control, I started chanting at that time."(Nichiren Buddhism) Italian Manuel de pepe (1970-), italian actor,producer and singer. He converted to Buddhism in 2011. (Secular Buddhism) Marco Columbro (1950- ), is an Italian actor and television host.(Tibetan Buddhism) Singer American David Bowie (8 January 1947 – 10 January 2016), was an English singer-songwriter and actor. Duncan Sheik American singer-songwriter and composer(Soka Gakkai International ) Steven Sater American playwright, lyricist and screenwriter best known for Spring Awakenings(Soka Gakkai International) Australian Jimmy Barnes , is an australian singer. British Howard Jones English musician, singer and songwriter Canadian Beverly Glenn-Copeland U.S.-born Canadian musician, songwriter and singer(Soka Gakkai International) k.d. lang, Canadian singer (Tibetan Buddhism) Chinese French Hong Konger Daniel Chan, is a popular Hong Kong singer, songwriter, and actor. He is most notable as one of the young talents in the 1990s music scene.Chan is a Buddhist.(Chan Buddhism) Indian Shibani Kashyap, Indian singer Italian Carmen Consoli Italian singer and songwriter Vietnamese Sport players Footballer Brett Kirk (1976–), is a former Australian rules football player of the Sydney Swans and was the AFL's International Ambassador. Kirk is currently serving as an assistant coach with the Sydney Swans.Kirk is known as a Buddhist and has a tattoo of a Buddhist symbol on his back. Fabien Barthez, French goalkeeper (1994–2006) of 1998 FIFA World Cup and Euro 2000-winning French national football team (Zen) Shunsuke Nakamura Japanese soccer player, midfielder for the Scottish team Celtic F.C. Sébastien Frey, is a French former professional footballer who played as a goalkeeper. His club career began in France with Cannes in 1997, but later went on to spend most of his career in the Italian Serie A, playing for Inter Milan, Hellas Verona, Parma, Fiorentina, and Genoa; he ended his career in 2015, after two seasons with Turkish side Bursaspor.Frey is a Buddhist and credited former Fiorentina legend Roberto Baggio as one of his spiritual mentors.(Soka Gakkai International) Roberto Baggio, Italian (1988–2004) footballer; in 1993, he was named FIFA World Player of the Year and won the Ballon d'Or (Soka Gakkai International) Mario Balotelli Barwuah, is an Italian buddhist professional footballer who plays as a striker for Süper Lig club Adana Demirspor. Balotelli started his professional football career at Lumezzane and played for the first team twice before having an unsuccessful trial at Barcelona, and subsequently joining Inter Milan in 2007. He is studying Buddhism in a bid to find inner peace.He has also bought several copies of the dharma, the religion’s teachings, and set up a quiet area with a statue of Buddha where he can meditate. (Pure Land Buddhism) Mehmet Scholl, is a German football manager and former player. He played most of his career as an attacking midfielder for Bayern Munich. During his career he won the UEFA Cup in 1996, the Euro 1996, and the UEFA Champions League in 2001, as well as eight German Championships.(Theravada) Cricketer Kumar Sangakkara (1977-) is a Sri Lankan cricket commentator, former professional cricketer, businessman, ICC Hall of Fame inductee, and the former president of Marylebone Cricket Club. He is widely regarded as one of the greatest wicket-keeper-batters in the history of the sport. (Theravada) Lasith Malinga (1981- ) is a Sri Lankan professional cricket player and Captain of T20 International cricket of Sri Lanka. he is considered as one of the greatest limited-overs bowlers of all time. He has got a lot of popularity for his ability to take Hat-trick in all three formats of the game. In addition to this, Malinga is the first player to take two world cup Hat-trick and three Hat-tricks in the ODIs.(Theravada) Tillakaratne Dilshan (1976–), Sri Lankan cricket player who converted from Islam to Buddhism at the age of 16, previously known as Tuwan Muhammad Dilshan. (Theravada) Tillakaratne Sampath (1982–), Sri Lankan cricket player who was previously known as Tuwan Mohammad Nishan Sampath Suraj Randiv (1985–), Sri Lankan cricket player.(Theravada) Swimer Anthony Ervin, american gold medilist swimer.(Zen) Rugby Jonny Wilkinson (1979- ), is an english former rugby union player. He is particularly known for scoring the winning drop goal in the 2003 Rugby World Cup Final and is widely acknowledged as one of the best rugby union players of all time. (Thravada) Golfer Tiger Woods, American golfer(Theravada) Military leaders Ellison Onizuka (1946–1986), U.S. Air Force Colonel and first Asian American astronaut of NASA (Pure Land Buddhism) Buddhist practitioners notable in other fields Kate Bosworth, American actress (Soka Gakkai International) John Cage, American composer (Zen Buddhism) Jennifer Aniston (1965- ) , American actress and producer. She famous for Freinds. (Zen) Robert Wright (1957–) American journalist and author.(Zen) Belinda Carlisle, American singer (Soka Gakkai International) Anne Louise Hassing Danish actress(Soka Gakkai International) Tisca Chopra, Indian actress (Soka Gakkai International) Edson Celulari, Brazilian actor Chow Yun-fat, Chinese actor Leonard Cohen, Canadian singer-songwriter/poet (Zen) Penélope Cruz, Spanish actress and model Shraddha Das, is an Indian actress and model who predominantly appears in Telugu, Hindi, and Kannada language films.(Theravada) George Dvorsky, Transhumanist, Futurist and one of directors of Humanity+ (Secular Buddhism) Richard Gere, American actor (Tibetan Buddhism) Allen Ginsberg, poet (Tibetan Buddhism) Philip Glass, American composer (Tibetan Buddhist) Herbie Hancock, American pianist and composer (Soka Gakkai International) Steve Jobs, American businessman, entrepreneur, marketer, inventor and the CEO of Apple Inc (Zen) Jack Kerouac, American novelist (Zen and Tibetan Buddhism; also the Catholic Church) Celeste Lecesne, American actor, author, screenwriter, LGBT rights activist, founder of The Trevor Project (Soka Gakkai International) Jet Li, Chinese martial artist, Hollywood actor (Tibetan Buddhist) Courtney Love, American singer-songwriter (Soka Gakkai International) Naima Mora, fashion model, winner of America's Next Top Model (Soka Gakkai International) Hansika Motwani, is an Indian actress who predominantly appears in Tamil and Telugu films. She is Buddhist. She said in an interview, “The best way to effectively de-stress for me is to chant- Nam Myo Ho Renge Kyo, as I strongly follow Buddhism.” (Tibetan Buddhism) Kenneth Pai, Chinese-American writer Maya Soetoro-Ng, Indonesian American writer, university instructor and maternal half-sister of Barack Obama, the 44th President of the United States Oliver Stone, American film director Sharon Stone, American actress, producer, and former fashion model Earl Sweatshirt, American rapper, songwriter, and record producer. (Nichiren Buddhism) George Takei, American actor and author (Theravada) Tina Turner, American singer-songwriter (Soka Gakkai International) Marcia Wallace, American actress, voice artist, comedian (Soka Gakkai International) Naomi Watts, British-Australian actress and film producer Faye Wong, Chinese singer and actress (Tibetan Buddhism) Michelle Yeoh, Malaysian actress Priscilla Chan, pediatrician and philanthropist, wife of Facebook founder Mark Zuckerberg Fictional Buddhists Anime and Manga Gautama Buddha, protagonist from Saint Young Men The cast from Ah My Buddha Ikkyū, protagonist from Ikkyū-san The cast from Oseam Seishin Muroi, character from Shiki Yoh Asakura, protagonist of the anime/manga Shaman King Hanamaru Kunikida, character from Love Live! Sunshine!! Miroku, character from Japanese Anime Inuyasha Krillin, character from the Dragonball series Kaname Asahina, Chiaki and Yūsei, characters from Brothers Conflict Chichiri, character from Fushigi Yūgi Yakumo Kokonoe, character from The Irregular at Magic High School Mayura Sōda, Miyuki Sagara, and Yukimasa Sagara, characters from RDG: Red Data Girl Keisei Tagami and Akasha Shishidō, characters from the Corpse Princess series Anji Yūkyūzan, character from Rurouni Kenshin Enkai, character from Requiem from the Darkness Graphic novels Enigma, a Marvel Comics superheroine Xorn, Marvel Comics character and member of the X-Men Green Lama, an American pulp magazine hero Green Arrow (Connor Hawke), DC Comics superhero Literature Sun Wukong, Monkey King in Chinese epic novel Journey to the West, and a fictional pupil of historical Chinese monk Xuanzang Mary Elizabeth, character from the novel The Perks of Being a Wallflower Film and television Steve Jinks, a character from Warehouse 13, (Season 3, Episode 1) "The New Guy" Daryl Dixon, character from The Walking Dead, Episode 8 (Season 2, Episode 2) "Bloodletting" Kahn Souphanousinphone, character from the cartoon King of the Hill Connie Souphanousinphone, character from the cartoon King of the Hill Dale Cooper, protagonist of the television series Twin Peaks Kyle Valenti, character from the television series Roswell Lisa Simpson, feminist and daughter of Homer and Marge Simpson, character from the cartoon The Simpsons Episode 275 (Season 13 Episode 6) "She of Little Faith" , Carl Carlson and Lenny Leonard Trini Kwan, original Yellow Ranger of the Mighty Morphin Power Rangers Wendy Wu, protagonist of the Disney Channel Original Movie Wendy Wu: Homecoming Warrior Master Splinter, a Zen sensei/teacher to the Teenage Mutant Ninja Turtles Hiro Nakamura, protagonist character in TV series Heroes Gi, the Planeteer able to wield the element water Edina Monsoon (Eddy) from the Absolutely Fabulous TV sitcom The God character in South Park, Episode 58 (Season 4, Episode 11) "Probably" Charlie Crews, Zen Buddhist, protagonist of television series Life Buddha, character from Air Buddies Satomi Ito, Alpha Werewolf and leader of Buddhist werewolf pack in the television series Teen Wolf (2011 TV series) Video Games Liu Kang, character from the video game and later movie, Mortal Kombat Sage, a class of trainer from the Pokémon series Misc 2D, lead singer and keyboardist of the British virtual band Gorillaz Jeremy, from the popular web series Pure Pwnage See also Awgatha Three Refuges Five precepts Dalit Buddhist movement Jewish Buddhists List of Marathi Buddhists List of converts to Buddhism List of converts to Buddhism from Christianity List of converts to Buddhism from Hinduism Outline of Buddhism References Lists of religious people lists Rinpoches	[ 0.5049760937690735, 0.7136080265045166, -1.025646448135376, -0.41617605090141296, -1.0337212085723877, 0.4345857501029968, 1.3755792379379272, 0.6822246313095093, -0.8784171938896179, 0.21062909066677094, -0.3890960216522217, -0.08696825802326202, -0.14050471782684326, 0.19304822385311127,...
18166	https://en.wikipedia.org/wiki/List%20of%20agnostics	List of agnostics	Listed here are persons who have identified themselves as theologically agnostic. Also included are individuals who have expressed the view that the veracity of a god's existence is unknown or inherently unknowable. List Activists and authors Saul Alinsky (1909–1972): American community organizer and writer; Rules for Radicals. Poul Anderson (1926–2001): American science fiction author. Piers Anthony (born 1934): English-American writer of science fiction and fantasy. Susan B. Anthony (1820–1906): American civil rights leader who played a pivotal role in the 19th century women's rights movement to introduce women's suffrage into the United States; co-founder of the first Women's Temperance Movement with Elizabeth Cady Stanton as President. Hannah Arendt (1906–1975): German American writer and political theorist. Samuel Beckett (1906–1989): Irish avant-garde novelist, playwright, theatre director, and poet; awarded the Nobel Prize in Literature in 1969. Ambrose Bierce (1842 – c. 1913): American editorialist, journalist, short story writer, fabulist and satirist; known for his short story "An Occurrence at Owl Creek Bridge" and his satirical lexicon The Devil's Dictionary. Jorge Luis Borges (1899–1986): Argentine writer. Henry Cadbury (1883–1974): English biblical scholar and Quaker who contributed to the New Revised Standard Version of the Bible. Thomas Carlyle (1795–1881): Scottish satirical writer, essayist, historian and teacher during the Victorian era. Ariel Dorfman (born 1942): Argentine/Chilean novelist, playwright, essayist, academic, and human rights activist. Arthur Conan Doyle (1859–1930): Scottish physician and writer; known for his stories about the detective Sherlock Holmes; a prolific writer whose other works include science fiction stories, plays, romances, poetry, non-fiction and historical novels. W.E.B. Du Bois (1868–1963): American sociologist, historian, civil rights activist, Pan-Africanist, author and editor; co-founder of the National Association for the Advancement of Colored People (NAACP) in 1909. Bart D. Ehrman (born 1955): American New Testament scholar and "a happy agnostic". Edward FitzGerald (1809–1883): English poet and writer, best known as the poet of the first and most famous English translation of The Rubaiyat of Omar Khayyam Betty Friedan (1921–2006): American writer, activist and feminist; a leading figure in the women's movement in the United States; her 1963 book, The Feminine Mystique, is often credited with sparking the "second wave" of American feminism in the 20th century. Frederick James Furnivall (1825–1910): English second editor of the Oxford English Dictionary. John Galsworthy (1867–1933): English novelist and playwright; The Forsyte Saga (1906–1921) and its sequels, A Modern Comedy and End of the Chapter; won the Nobel Prize in Literature in 1932 Neil Gaiman (born 1960): English author of short fiction, novels, comic books, graphic novels, audio theatre and films including the comic book series The Sandman and novels Stardust, American Gods, Coraline, and The Graveyard Book. Maxim Gorky (1868–1936): Russian and Soviet author who brought Socialist Realism to literature. Thomas Hardy (1840–1928): English novelist and poet; while his works typically belong to the Naturalism movement, several poems display elements of the previous Romantic and Enlightenment periods of literature, such as his fascination with the supernatural. Sadegh Hedayat (1903–1951): Iranian author and writer. Robert A. Heinlein (1907–1988): American science fiction writer. Joseph Heller (1923–1999): American satirical novelist, short story writer, and playwright; Catch-22. Alexander Herzen (1812–1870): Russian writer and thinker; the "father of Russian socialism"; one of the main fathers of agrarian populism. Aldous Huxley (1894–1963): English writer of novels, such as Brave New World, and wide-ranging essays. A.J. Jacobs (born 1968): American author. James Joyce (1882–1941): Irish novelist and poet, considered to be one of the most influential writers in the modernist avant-garde movement of the early 20th century; best known for his novel Ulysses. Franz Kafka (1883–1924): Czech-born Jewish writer. John Keats (1795–1821): English Romantic poet. Janusz Korczak (1878 or 1879–1942): Polish Jewish educator, children's author and pediatrician. After spending many years working as director of an orphanage in Warsaw, Korczak refused freedom and remained with the orphans as they were sent to Treblinka extermination camp during the Grossaktion Warsaw of 1942. Stanislaw Lem (1921–2006): Polish science fiction novelist and essayist. H. P. Lovecraft (1890–1937): American writer of strange fiction and horror. Lucretius (99 BC–55 BC): Roman poet and philosopher. Bernard Malamud (1914–1986): American author of novels and short stories; one of the great American Jewish authors of the 20th century. H. L. Mencken (1880–1956): German-American journalist, satirist, social critic, cynic and freethinker, known as the "Sage of Baltimore". Thomas Mann (1875–1955): German novelist, short story writer, social critic, philanthropist, essayist, and 1929 Nobel Prize laureate, known for his series of highly symbolic and ironic epic novels and novellas, noted for their insight into the psychology of the artist and the intellectual. Vladimir Nabokov (1899–1977): Russian novelist, poet and short story writer; known for his novel Lolita. Eugene O'Neill (1888–1953), American playwright; won the Nobel Prize in Literature in 1936. Larry Niven (born 1938): American science fiction author; Ringworld (1970). Fernando Pessoa (1888–1935): Portuguese poet, writer, literary critic and translator, described as one of the most significant literary figures of the 20th century and one of the greatest poets in Portuguese. Marcel Proust (1871–1922): French novelist, critic and essayist, known for his work In Search of Lost Time. Philip Pullman (born 1946): English children's author of the trilogy His Dark Materials; has said that he is technically an agnostic, though he also calls himself an atheist. Alexander Pushkin (1799–1837): Russian author of the Romantic era, considered by many to be the greatest Russian poet and the founder of modern Russian literature. Edward Said (1935–2003): Palestinian-American literary theorist and advocate for Palestinian rights; university professor of English and Comparative Literature at Columbia University; a founding figure in postcolonialism. Arthur M. Schlesinger Jr. (1917–2007): American historian and Pulitzer Prize–winning writer. Mary Shelley (1797–1851): English novelist, short story writer, dramatist, essayist, biographer, and travel writer, best known for her Gothic novel Frankenstein (1818). Edward Snowden (born 1983): American computer specialist, privacy activist and former CIA employee and NSA contractor; disclosed classified details of several top-secret United States and British government mass surveillance programs. Elizabeth Cady Stanton (1815–1902): American social activist, abolitionist, and leading figure of the early woman's movement. Her Declaration of Sentiments, presented at the Seneca Falls Convention held in 1848 in Seneca Falls, New York, is often credited with initiating the first organized woman's rights and woman's suffrage movements in the United States. Late in life she led the effort to write the Woman's Bible to correct the injustices she perceived against women in the Bible. Olaf Stapledon (1886–1950): English philosopher and author of several influential works of science fiction. John Steinbeck (1902–1968): American writer known for novels such as The Grapes of Wrath and East of Eden; won the Nobel Prize in Literature in 1962 Stendhal (1783–1842) (a.k.a. Marie-Henri Beyle): French writer. Boris Strugatsky (1925–2012): Soviet-Russian science fiction author who collaborated with his brother, Arkady Strugatsky, on various works; their novel Piknik na obochine was translated into English as Roadside Picnic in 1977 and was filmed by Andrei Tarkovsky under the title Stalker. Charles Templeton (1915–2001): Canadian evangelist; author of A Farewell to God. Thucydides (c. 460–c. 395): Greek historian and author from Alimos. His History of the Peloponnesian War recounts the 5th-century BC war between Sparta and Athens to the year 411 BC. Thucydides has been dubbed the father of "scientific history", because of his strict standards of evidence-gathering and analysis in terms of cause and effect without reference to intervention by the gods, as outlined in his introduction to his work. Ivan Turgenev (1818–1883): Russian novelist, short story writer and playwright; A Sportsman's Sketches, Fathers and Sons. Mark Twain (1835–1910): American humorist, satirist, lecturer and writer, most noted for his novels Adventures of Huckleberry Finn and The Adventures of Tom Sawyer; has also been identified a deist. Adam Bruno Ulam (1922–2000): Polish and American historian and political scientist at Harvard University; one of the world's foremost authorities on Russia and the Soviet Union, and the author of twenty books and many articles. Ibn Warraq (born 1946): known for his books critical of Islam. Hale White (1831–1913): British writer and civil servant. Robert Anton Wilson (1932–2007): American author and futurologist Mary Wollstonecraft (1759–1797): English writer, philosopher, and advocate of women's rights. During her brief career, she wrote novels, treatises, a travel narrative, a history of the French Revolution, a conduct book, and a children's book. Wollstonecraft is best known for A Vindication of the Rights of Woman (1792), in which she argues that women are not naturally inferior to men, but appear to be only because they lack education. She suggests that both men and women should be treated as rational beings and imagines a social order founded on reason. David Yallop (born 1937): English true crime author. Émile Zola (1840–1902): French writer; prominent figure in the literary school of naturalism; important contributor to the development of theatrical naturalism. Business Leslie Alexander (born 1943): American sports owner, owner of the Houston Rockets Warren Buffett (born 1930): American investor; identified himself as agnostic in response to Warren Allen Smith, who had asked him whether he believed in God Henry Dunant (1828–1910): Swiss businessman and social activist; founder of International Committee of the Red Cross; in 1901 he received the first Nobel Peace Prize, together with Frédéric Passy Elon Musk (born 1971): South African American inventor and entrepreneur best known for founding SpaceX and co-founding Tesla Motors and PayPal (originally X.com) Ted Turner (born 1938): American founder of Turner Broadcasting System, now part of Time Warner Media and arts John Adams (born 1947): American composer Hideaki Anno (born 1960): Japanese animation and film director; known for his work on the popular anime series Neon Genesis Evangelion Simon Baker (born 1969): Australian television and movie actor David Bazan (born 1976): American singer, songwriter, musician and former frontman of Pedro The Lion, an indie rock outfit associated with Christian rock that was controversial among Christians for their language and off-kilter views about religion; his solo career has been focused around his newfound agnosticism. Monica Bellucci (born 1964): Italian actress and fashion model Tom Bergeron (born 1955): American television personality and game show host; host of America's Funniest Home Videos, Hollywood Squares and Dancing with the Stars Ingmar Bergman (1918–2007): Swedish director, writer and producer for film, stage and television Irving Berlin (1888–1989): American composer and lyricist of Jewish heritage, widely considered one of the greatest songwriters in American history Hector Berlioz (1803–1869): French Romantic composer Gael García Bernal (born 1978): Mexican actor and director; claims to be "culturally Catholic" and "spiritually agnostic" Lewis Black (born 1948): American stand-up comedian, author, playwright, social critic and actor Johannes Brahms (1833–1897): German composer and pianist Georges Brassens (1921–1981): French singer-songwriter and poet Benjamin Britten (1913–1976): English composer, conductor, and pianist; a central figure of 20th-century British classical music Gavin Bryars (born 1943): English composer and double bassist Rose Byrne (born 1979), Australian actress Dick Cavett (born 1936): American television talk show host Charlie Chaplin (1889–1977): English comic actor, film director and composer best known for his work in the United States during the silent film era Aaron Copland (1900–1990): American composer Salvador Dalí (1904–1989): Spanish surrealist painter born in Figueres, Spain. Dalí, a skilled draftsman, became best known for the striking and bizarre images in his surrealist work. His painterly skills are often attributed to the influence of Renaissance masters. His arguably best-known work, The Persistence of Memory, was completed in 1931. Dalí's expansive artistic repertoire included film, sculpture, and photography, in collaboration with a range of artists in a variety of media. He allegedly claimed to be both an agnostic and a Roman Catholic. Miles Davis (1926–1991): American trumpeter, bandleader, and composer. Daniel Day-Lewis (born 1957): English-Irish actor, three-time Academy Award for Best Actor winner Leonardo DiCaprio (born 1974): American actor Ronnie James Dio (1942–2010): American heavy metal singer (Elf, Rainbow, Black Sabbath, Dio, Heaven & Hell) Richard Dreyfuss (born 1947): American actor Thomas Eakins (1844–1916): American realist painter, photographer, sculptor, and fine arts educator; widely acknowledged to be one of the most important artists in American art history Christopher Eccleston (born 1964): English actor Zac Efron (born 1987): American actor, star of movies such as High School Musical and 17 Again; was raised agnostic (his paternal grandfather was Jewish) Carrie Fisher (1956–2016): American actress, screenwriter and novelist Gabriel Fauré (1845–1924): French composer, organist, pianist and teacher; one of the foremost French composers of his generation; his musical style influenced many 20th-century composers Henry Fonda (1905–1982): American film and stage actor Emilia Fox (born 1974): English actress William Friedkin (born 1935): American film and television director, producer and screenwriter, known for directing the action thriller film The French Connection and the supernatural horror film The Exorcist. Gilberto Gil (born 1942): Brazilian singer, guitarist, and songwriter, known for both his musical innovation and political commitment Jean-Luc Godard (born 1930): French-Swiss film director, screenwriter and film critic; often identified with the 1960s French film movement La Nouvelle Vague, or "New Wave" Matt Groening (born 1954): American creator of animated TV series The Simpsons and Futurama, and the comic Life in Hell Bob Guccione (1930–2010): American founder and publisher of Penthouse magazine Neil Patrick Harris (born 1973): American actor, producer, singer, and director; best known for Doogie Howser, M.D. and How I Met Your Mother; as a child, belonged to an Episcopal Church with his family, where he sang in choir, but has designated himself as an agnostic on his Myspace Hergé (1907–1983): Belgian cartoonist; creator of The Adventures of Tintin Gustav Holst (1874–1934): English composer, arranger and teacher; best known for his orchestral suite The Planets; composed a large number of works across a range of genres, although none achieved comparable success John Humphrys (born 1943): English radio and television presenter who hosted a series of programmes interviewing religious leaders, Humphrys in Search of God Leoš Janáček (1854–1928): Czech composer Gene Kelly (1912–1996): American dancer, actor, singer, film director and producer, and choreographer Myles Kennedy (born 1969): American musician, singer, and songwriter; lead vocalist and guitarist of the rock band Alter Bridge Larry King (1933–2021): host of Larry King Live Janez Lapajne (born 1967): Slovenian film director, producer, screenwriter, film editor and production designer Cloris Leachman (1926–2021): American actress Stan Lee (1922–2018) American comic book writer, editor, actor, producer, publisher, television personality; former president and chairman of Marvel Comics Lemmy (1945–2015): English rock singer and bass guitarist; founder of the rock band Motörhead Joe Lipari also known as J.R. Lipari, (born October 5, 1979) is an American comedian, artist, agnostic minister & yoga teacher. James Hetfield (born 1963): American heavy metal singer and rhythm guitarist; co-founder of the heavy metal band Metallica Annie Lennox (born 1954): Scottish recording artist Andrew Lloyd Webber (born 1948): Lloyd Webber views Jesus as one of "one of the great figures of history" and wrote the rock opera Jesus Christ Superstar about him. The opera was controversial with conservative Christian groups. René Magritte (1898–1967): Belgian surrealist artist Gustav Mahler (1860–1911): Austrian Late-Romantic composer and conductor Dave Matthews (born 1967): American musician and actor Brian May (born 1947): English musician and astrophysicist most widely known as the guitarist, songwriter and occasional singer of the rock band Queen. Paul McCartney (born 1942): English musician, singer and composer David Mitchell (born 1974): British actor, comedian and writer Edvard Munch (1863–1944): Norwegian Symbolist painter, printmaker and an important forerunner of expressionist art; known for The Scream Ernest Newman (1868–1959): English music critic and musicologist Conor Oberst (born 1980): American singer-songwriter; fronts the band Bright Eyes Hubert Parry (1848–1918): English composer, teacher and historian of music Neil Peart (1952–2020): Canadian drummer and lyricist for progressive rock band Rush; many Rush song lyrics criticize religion and theism Sean Penn (born 1960): American actor, twice winner of the Academy Award for Best Actor Brendan Perry (born 1959): English singer and multi-instrumentalist best known for his work as the male half of the duo Dead Can Dance with Lisa Gerrard Chris Pine (born 1980): American actor Brad Pitt (born 1963): American actor; stated that he did not believe in God, and that he was mostly agnostic Sidney Poitier (1927–2022): Bahamian American actor, film director, author, and diplomat; his views are closer to deism Hugo Riemann (1949–1919): German music theorist and composer Joe Rogan (born 1967): American comedian, podcaster, social critic and UFC color commentator Andy Rooney (1919–2011): American broadcast personality; specified that he was an agnostic and not an atheist, but also called himself an atheist Tim Rice (born 1944): Wrote the rock opera Jesus Christ Superstar about Jesus. The opera was controversial with conservative Christians. Larry Sanger (born 1968): American co-founder of Wikipedia. Franz Schubert (1797–1828): Austrian composer Robert Schumann (1810–1856): German composer and influential music critic; widely regarded as one of the greatest composers of the Romantic era Ridley Scott (born 1937): English film director and producer; Alien (1979), Blade Runner Adrienne Shelly (1966–2006), American actor, screenwriter and director Richard Strauss (1864–1949): German composer of the late Romantic and early modern eras Howard Stern (born 1954): American radio personality, television host, author, actor, and photographer Sting (born 1951): English musician and lead singer of The Police Matt Stone (born 1971): American co-creator of the cartoon series South Park; considers himself an agnostic Jew (his mother is Jewish), though he has also denied the existence of God Osamu Tezuka (1928–1989): Japanese cartoonist, manga artist, animator, producer, activist and medical doctor; creator of Astro Boy, Kimba the White Lion and Black Jack; often credited as the "godfather of anime", and is often considered the Japanese equivalent to Walt Disney Jhonen Vasquez (born 1974): American comic book writer, and cartoonist; known for the animated series Invader Zim Giuseppe Verdi (1813–1901): Italian composer, one of the most influential of the 19th century Robert Jastrow (1925–2008): American astronomer, physicist and cosmologist. Edwin Thompson Jaynes (1922–1998): American physicist and statistician. He wrote extensively on statistical mechanics and on foundations of probability and statistical inference. He also pioneered the field of Digital physics. James Hopwood Jeans (1877–1946): English physicist, astronomer and mathematician. Jerome Karle (1918–2013): American physical chemist. Jointly with Herbert A. Hauptman, he was awarded the Nobel Prize in Chemistry in 1985, for the direct analysis of crystal structures using X-ray scattering techniques. August Kekulé (1829–1896): German organic chemist. He was one of the most prominent chemists in Europe, especially in theoretical chemistry. He was the principal founder of the theory of chemical structure. John Kendrew (1917–1997): English biochemist and crystallographer who shared the 1962 Nobel Prize in Chemistry with Max Perutz; their group in the Cavendish Laboratory investigated the structure of heme-containing proteins. John Maynard Keynes (1883–1946): British economist. His ideas are the basis for the school of thought known as Keynesian economics, as well as its various offshoots. Michio Kaku (born 1947): American theoretical physicist. Alfred Kastler (1902–1984): French physicist. He won the Nobel Prize in Physics in 1966. Joseph-Louis Lagrange (1736–1813): Italian-French mathematician and astronomer. He made significant contributions to all fields of analysis, number theory, and classical and celestial mechanics. Irving Langmuir (1881–1957): American chemist and physicist. He was awarded the 1932 Nobel Prize in Chemistry for his work in surface chemistry. Anthony James Leggett (born 1938): English-American physicist. Professor Leggett is widely recognized as a world leader in the theory of low-temperature physics, and his pioneering work on superfluidity was recognized by the 2003 Nobel Prize in Physics. Joseph Leidy (1823–1891): American paleontologist. Mario Livio (born 1945): Israeli-American astrophysicist. Seth Lloyd (born 1960): American mechanical engineer. He is a professor of mechanical engineering at the Massachusetts Institute of Technology. James Lovelock (born 1919): British scientist, environmentalist and futurologist. He is best known for proposing the Gaia hypothesis. Percival Lowell (1855–1916): American businessman, author, mathematician, and astronomer who fueled speculation that there were canals on Mars, founded the Lowell Observatory in Flagstaff, Arizona, and formed the beginning of the effort that led to the discovery of Pluto 14 years after his death. Frank Malina (1912–1981): American aeronautical engineer and painter, especially known for becoming both a pioneer in the art world and the realm of scientific engineering. Rudolph A. Marcus (born 1923): Canadian-born chemist who received the 1992 Nobel Prize in Chemistry for his theory of electron transfer. Lynn Margulis (1938–2011): American biologist. She is best known for her theory on the origin of eukaryotic organelles, and her contributions to the endosymbiotic theory, which is now generally accepted for how certain organelles were formed. She is also associated with the Gaia hypothesis, based on an idea developed by the English environmental scientist James Lovelock. Dan McKenzie (geophysicist) (born 1942): British geophysicist. Simon van der Meer (1925–2011): Dutch particle accelerator physicist who shared the Nobel Prize in Physics in 1984 with Carlo Rubbia for contributions to the CERN project which led to the discovery of the W and Z particles, two of the most fundamental constituents of matter. Albert Abraham Michelson (1852–1931): American physicist known for his work on the measurement of the speed of light and especially for the Michelson–Morley experiment. In 1907 he received the Nobel Prize in Physics. Ludwig von Mises (1881–1973): Austrian Economist and Philosopher. He was a prominent figure in the Austrian School of economic thought. Ludwig Mond (1839–1909): German-born British chemist and industrialist. Robert S. Mulliken (1896–1986): American physicist and chemist, primarily responsible for the early development of molecular orbital theory, i. e. the elaboration of the molecular orbital method of computing the structure of molecules. Dr. Mulliken received the Nobel Prize for chemistry in 1966. Nathan Myhrvold (born 1959): American computer scientist, technologist, mathematician, physicist, entrepreneur, nature and wildlife photographer, master chef. David Nalin (born 1941): American physiologist. Nalin had the key insight that Oral rehydration therapy (ORT) would work if the volume of solution patients drank matched the volume of their fluid losses, and that this would drastically reduce or completely replace the only current treatment for cholera, intravenous therapy. Nalin's discoveries have been estimated to have saved over 50 million lives worldwide. Fridtjof Nansen (1861–1930): Norwegian explorer, scientist, diplomat, humanitarian and Nobel Peace Prize laureate. In 1922, he was awarded the Nobel Peace Prize for his work on behalf of the displaced victims of the First World War and related conflicts. Erwin Neher (born 1944): German biophysicist. Along with Bert Sakmann, he was awarded the Nobel Prize in Physiology or Medicine in 1991. Ronald George Wreyford Norrish (1897–1978): British chemist. As a result of the development of flash photolysis, he was awarded the Nobel Prize in Chemistry in 1967 along with Manfred Eigen and George Porter for their study of extremely fast chemical reactions. Robert Noyce (1927–1990): American physicist, businessman, and inventor. He co-founded Fairchild Semiconductor in 1957 and Intel Corporation in 1968. He is also credited (along with Jack Kilby) with the invention of the integrated circuit or microchip which fueled the personal computer revolution. Sherwin B. Nuland (1930–2014): American surgeon and author of How We Die. Paul Nurse (born 1949): 2001 Nobel Laureate in Physiology or Medicine, called himself an atheist, but specified that "sceptical agnostic" was a more "philosophically correct" term. Bill Nye (born 1955): American science educator, comedian, television host, actor, mechanical engineer and scientist. Popularly known as "Bill Nye the Science Guy". George Olah (1927–2017): 1994 Nobel Laureate in Chemistry, discoverer of superacids, Mark Oliphant (1901–2000): Australian physicist and humanitarian. He played a fundamental role in the first experimental demonstration of nuclear fusion and also the development of the atomic bomb. Karl Pearson (1857–1936): English mathematician who has been credited for establishing the discipline of mathematical statistics. Saul Perlmutter (born 1959): American astrophysicist. He shared both the 2006 Shaw Prize in Astronomy and the 2011 Nobel Prize in Physics with Brian P. Schmidt and Adam Riess for providing evidence that the expansion of the universe is accelerating. Henri Poincaré (1854–1912): French mathematician, theoretical physicist, engineer, and a philosopher of science. He is often described as a polymath, and in mathematics as The Last Universalist, since he excelled in all fields of the discipline as it existed during his lifetime. Siméon Denis Poisson (1781–1840): French mathematician, geometer, and physicist. George Pólya (1888–1985): Hungarian Jewish mathematician. He was a professor of mathematics from 1914 to 1940 at ETH Zürich and from 1940 to 1953 at Stanford University. He made fundamental contributions to combinatorics, number theory, numerical analysis and probability theory. He is also noted for his work in heuristics and mathematics education. Carolyn Porco (born 1953): American planetary scientist. She is best known for her work in the exploration of the outer Solar System, beginning with her imaging work on the Voyager missions to Jupiter, Saturn, Uranus and Neptune in the 1980s. Vladimir Prelog (1906–1998): Croatian organic chemist. He won the Nobel Prize in Chemistry in 1975. Vilayanur S. Ramachandran (born 1951): Indian-American neuroscientist. Best known for his work in the fields of behavioral neurology and visual psychophysics. C. V. Raman (1888–1970): Indian physicist whose work was influential in the growth of science in India. He was the recipient of the Nobel Prize for Physics in 1930 for the discovery that when light traverses a transparent material, some of the light that is deflected changes in wavelength. This phenomenon is now called Raman scattering and is the result of the Raman effect. Lisa Randall (born 1962): American theoretical physicist and a student of particle physics and cosmology. She works on several of the competing models of string theory in the quest to explain the fabric of the universe. Her best known contribution to the field is the Randall–Sundrum model, first published in 1999 with Raman Sundrum. John Strutt, 3rd Baron Rayleigh (1842–1919): English physicist who, with William Ramsay, discovered the element argon, an achievement for which he earned the Nobel Prize for Physics in 1904. He also discovered the phenomenon now called Rayleigh scattering, explaining why the sky is blue, and predicted the existence of the surface waves now known as Rayleigh waves. Rayleigh's textbook, The Theory of Sound, is still referred to by acoustic engineers today. Grote Reber (1911–2002): American amateur astronomer and pioneer of radio astronomy. He was instrumental in investigating and extending Karl Jansky's pioneering work, and conducted the first sky survey in the radio frequencies. His 1937 radio antenna was the second ever to be used for astronomical purposes and the first parabolic reflecting antenna to be used as a "radio telescope". Robert Coleman Richardson (1937–2013): American experimental physicist. He, along with David Lee, as senior researchers, and then graduate student Douglas Osheroff, shared the 1996 Nobel Prize in Physics for their 1972 discovery of the property of superfluidity in helium-3 atoms in the Cornell University Laboratory of Atomic and Solid State Physics. Charles Richet (1850–1935): French physiologist, won the 1913 Nobel Prize in Physiology or Medicine for his work on anaphylaxis. Isaac Roberts (1829–1904): Welsh engineer and business man best known for his work as an amateur astronomer, pioneering the field of astrophotography of nebulae. Richard J. Roberts (born 1943): British biochemist and molecular biologist. He was awarded the 1993 Nobel Prize in Physiology or Medicine with Phillip Allen Sharp for the discovery of introns in eukaryotic DNA and the mechanism of gene-splicing. Józef Rotblat (1908–2005): Polish-British physicist. Along with the Pugwash Conferences on Science and World Affairs, he received the Nobel Peace Prize in 1995. Carl Sagan (1934–1996): astronomer and skeptic. Frederick Sanger (1918–2013): English biochemist and a two-time Nobel Laureate in Chemistry. Nicholas Saunderson (1682–1739): English scientist and mathematician. Peter Schuster (born 1941): Professor of Theoretical Chemistry at the University of Vienna. Harlow Shapley (1885–1972): American astronomer. Best known for determining the correct position of the Sun within the Milky Way galaxy. Charles Scott Sherrington (1857–1952): English neurophysiologist, histologist, bacteriologist, and pathologist. He, along with Edgar Adrian, won the 1932 Nobel Prize in Physiology or Medicine. George Gaylord Simpson (1902–1984): American paleontologist. He is considered to be one of the most influential paleontologist of the 20th century, and a major participant in the modern evolutionary synthesis. Jens C. Skou (1918–2018): Danish chemist. In 1997 he received the Nobel Prize in Chemistry (together with Paul D. Boyer and John E. Walker) for his discovery of Na+, K+-ATPase. Homer Smith (1895–1962): American physiologist. His research work focused on the kidney and he discovered inulin at the same time as A.N. Richards. William Smith (geologist) (1769–1839): English geologist, credited with creating the first nationwide geological map. He is known as the "Father of English Geology" for collating the geological history of England and Wales into a single record, although recognition was very slow in coming. George Smoot (born 1945): American astrophysicist, cosmologist, Nobel laureate, and $1 million TV quiz show prize winner (Are You Smarter Than a 5th Grader?). He won the Nobel Prize in Physics in 2006 for his work on the Cosmic Background Explorer with John C. Mather that led to the measurement "of the black body form and anisotropy of the cosmic microwave background radiation." Charles Proteus Steinmetz (1865–1923): German-American mathematician and electrical engineer. Piero Sraffa (1898–1983): influential Italian economist whose book Production of Commodities by Means of Commodities is taken as founding the Neo-Ricardian school of Economics. Albert Szent-Györgyi (1893–1986): Hungarian physiologist who won the Nobel Prize in Physiology or Medicine in 1937. He is credited with discovering vitamin C and the components and reactions of the citric acid cycle. Leo Szilard (1898–1964): Austro-Hungarian physicist and inventor. Igor Tamm (1895–1971): Soviet physicist who received the 1958 Nobel Prize in Physics, jointly with Pavel Alekseyevich Cherenkov and Ilya Frank, for their 1934 discovery of Cherenkov radiation. Edward Teller (1908–2003): Hungarian-American theoretical physicist, known colloquially as "the father of the hydrogen bomb". Teller made numerous contributions to nuclear and molecular physics, spectroscopy (the Jahn–Teller and Renner–Teller effects), and surface physics. Thorvald N. Thiele (1838–1910): Danish astronomer, actuary and mathematician, most notable for his work in statistics, interpolation and the three-body problem. He was the first to propose a mathematical theory of Brownian motion. Thiele introduced the cumulants and (in Danish) the likelihood function; these contributions were not credited to Thiele by Ronald A. Fisher, who nevertheless named Thiele to his (short) list of the greatest statisticians of all time on the strength of Thiele's other contributions. E. Donnall Thomas (1920–2012): American physician, professor emeritus at the University of Washington, and director emeritus of the clinical research division at the Fred Hutchinson Cancer Research Center. In 1990 he shared the Nobel Prize in Physiology or Medicine with Joseph E. Murray for the development of cell and organ transplantation. Thomas developed bone marrow transplantation as a treatment for leukemia. John Tyndall (1820–1893): Prominent 19th century experimental physicist. Known for producing a number of discoveries about processes in the atmosphere. Neil deGrasse Tyson (born 1958): American astrophysicist, science communicator, the Frederick P. Rose Director of the Hayden Planetarium at the Rose Center for Earth and Space, and a Research Associate in the Department of Astrophysics at the American Museum of Natural History. Stanislaw Ulam (1909–1984): Polish-Jewish mathematician. He participated in America's Manhattan Project, originated the Teller–Ulam design of thermonuclear weapons, invented the Monte Carlo method of computation, and suggested nuclear pulse propulsion. Martinus J. G. Veltman (1931–2021): Dutch theoretical physicist. He shared the 1999 Nobel Prize in Physics with his former student Gerardus 't Hooft for their work on particle theory. Rudolf Virchow (1821–1902): German doctor, anthropologist, pathologist, prehistorian, biologist and politician. Referred to as "the father of modern pathology," he is considered one of the founders of social medicine. John von Neumann (1903–1957): Hungarian-American mathematician and polymath who made major contributions to a vast number of fields, including set theory, functional analysis, quantum mechanics, ergodic theory, geometry, fluid dynamics, economics, linear programming, game theory, computer science, numerical analysis, hydrodynamics, and statistics, as well as many other mathematical fields. It is indicated that he was an "agnostic Catholic" due to his agreement with Pascal's Wager. Alfred Russel Wallace (1823–1913): British naturalist, explorer, geographer, anthropologist and biologist. He is best known for independently proposing a theory of evolution due to natural selection that prompted Charles Darwin to publish his own theory. André Weil (1906–1998): French mathematician. He is especially known for his foundational work in number theory and algebraic geometry. Walter Frank Raphael Weldon (1860–1906): English evolutionary biologist and a founder of biometry. He was the joint founding editor of Biometrika, with Francis Galton and Karl Pearson. Norbert Wiener (1894–1964): American mathematician and child prodigy. He is regarded as the originator of cybernetics. Eugene Wigner (1902–1995): Hungarian American theoretical physicist and mathematician. He received a share of the Nobel Prize in Physics in 1963 "for his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles"; the other half of the award was shared between Maria Goeppert-Mayer and J. Hans D. Jensen. Wigner is important for having laid the foundation for the theory of symmetries in quantum mechanics as well as for his research into the structure of the atomic nucleus. It was Eugene Wigner who first identified Xe-135 "poisoning" in nuclear reactors, and for this reason it is sometimes referred to as Wigner poisoning. Wigner is also important for his work in pure mathematics, having authored a number of theorems. Frank Wilczek (born 1951): American theoretical physicist. Along with David J. Gross and Hugh David Politzer, won the Nobel Prize in Physics in 2004. Steve Wozniak (born 1950): co-founder of Apple Computer and inventor of the Apple I and Apple II. Chen Ning Yang (born 1922): Chinese-born American physicist who works on statistical mechanics and particle physics. He and Tsung-dao Lee received the 1957 Nobel Prize in Physics for their work on parity nonconservation of weak interaction. Hubert Yockey (1916–2016): American physicist and information theorist. Hans Zinsser (1878–1940): American bacteriologist and a prolific author. He is known for his work in isolating the typhus bacterium and developing a protective vaccine. Celebrities and athletes Steve Austin (born 1964): American professional wrestler. Kristy Hawkins (born 1980): American IFBB professional bodybuilder and scientist. Edmund Hillary (1919–2008): New Zealand mountaineer, explorer and philanthropist. He along with Tenzing Norgay became the first climbers confirmed as having reached the summit of Mount Everest. Pat Tillman (1976–2004): American professional football player and U.S. Army veteran. Rafael Nadal (born 1986): Spanish professional tennis player. Rob Van Dam (born 1970): American professional wrestler, winner of three separate major promotion world championships. See also Lists of atheists List of secular humanists Lists of lists of people by belief Notes External links Agnostics in The Celebrity Atheist List Famous Black Freethinkers Famous Dead Nontheists Agnostics	[ 0.29534590244293213, 1.2486233711242676, -0.8155913352966309, -0.2987925112247467, -0.9423781633377075, 0.1629817932844162, 1.321354866027832, 0.9709562063217163, -0.560543417930603, 0.023082168772816658, -0.31714922189712524, -0.04969146475195885, -0.40507665276527405, 0.7944706678390503,...
18167	https://en.wikipedia.org/wiki/Linked%20list	Linked list	In computer science, a linked list is a linear collection of data elements whose order is not given by their physical placement in memory. Instead, each element points to the next. It is a data structure consisting of a collection of nodes which together represent a sequence. In its most basic form, each node contains: data, and a reference (in other words, a link) to the next node in the sequence. This structure allows for efficient insertion or removal of elements from any position in the sequence during iteration. More complex variants add additional links, allowing more efficient insertion or removal of nodes at arbitrary positions. A drawback of linked lists is that access time is linear (and difficult to pipeline). Faster access, such as random access, is not feasible. Arrays have better cache locality compared to linked lists. Linked lists are among the simplest and most common data structures. They can be used to implement several other common abstract data types, including lists, stacks, queues, associative arrays, and S-expressions, though it is not uncommon to implement those data structures directly without using a linked list as the basis. The principal benefit of a linked list over a conventional array is that the list elements can be easily inserted or removed without reallocation or reorganization of the entire structure because the data items need not be stored contiguously in memory or on disk, while restructuring an array at run-time is a much more expensive operation. Linked lists allow insertion and removal of nodes at any point in the list, and allow doing so with a constant number of operations by keeping the link previous to the link being added or removed in memory during list traversal. On the other hand, since simple linked lists by themselves do not allow random access to the data or any form of efficient indexing, many basic operations—such as obtaining the last node of the list, finding a node that contains a given datum, or locating the place where a new node should be inserted—may require iterating through most or all of the list elements. The advantages and disadvantages of using linked lists are given below. History Linked lists were developed in 1955–1956, by Allen Newell, Cliff Shaw and Herbert A. Simon at RAND Corporation as the primary data structure for their Information Processing Language. IPL was used by the authors to develop several early artificial intelligence programs, including the Logic Theory Machine, the General Problem Solver, and a computer chess program. Reports on their work appeared in IRE Transactions on Information Theory in 1956, and several conference proceedings from 1957 to 1959, including Proceedings of the Western Joint Computer Conference in 1957 and 1958, and Information Processing (Proceedings of the first UNESCO International Conference on Information Processing) in 1959. The now-classic diagram consisting of blocks representing list nodes with arrows pointing to successive list nodes appears in "Programming the Logic Theory Machine" by Newell and Shaw in Proc. WJCC, February 1957. Newell and Simon were recognized with the ACM Turing Award in 1975 for having "made basic contributions to artificial intelligence, the psychology of human cognition, and list processing". The problem of machine translation for natural language processing led Victor Yngve at Massachusetts Institute of Technology (MIT) to use linked lists as data structures in his COMIT programming language for computer research in the field of linguistics. A report on this language entitled "A programming language for mechanical translation" appeared in Mechanical Translation in 1958. Another early appearance of linked lists was by Hans Peter Luhn who wrote an internal IBM memorandum in January 1953 that suggested the use of linked lists in chained hash tables. LISP, standing for list processor, was created by John McCarthy in 1958 while he was at MIT and in 1960 he published its design in a paper in the Communications of the ACM, entitled "Recursive Functions of Symbolic Expressions and Their Computation by Machine, Part I". One of LISP's major data structures is the linked list. By the early 1960s, the utility of both linked lists and languages which use these structures as their primary data representation was well established. Bert Green of the MIT Lincoln Laboratory published a review article entitled "Computer languages for symbol manipulation" in IRE Transactions on Human Factors in Electronics in March 1961 which summarized the advantages of the linked list approach. A later review article, "A Comparison of list-processing computer languages" by Bobrow and Raphael, appeared in Communications of the ACM in April 1964. Several operating systems developed by Technical Systems Consultants (originally of West Lafayette Indiana, and later of Chapel Hill, North Carolina) used singly linked lists as file structures. A directory entry pointed to the first sector of a file, and succeeding portions of the file were located by traversing pointers. Systems using this technique included Flex (for the Motorola 6800 CPU), mini-Flex (same CPU), and Flex9 (for the Motorola 6809 CPU). A variant developed by TSC for and marketed by Smoke Signal Broadcasting in California, used doubly linked lists in the same manner. The TSS/360 operating system, developed by IBM for the System 360/370 machines, used a double linked list for their file system catalog. The directory structure was similar to Unix, where a directory could contain files and other directories and extend to any depth. Basic concepts and nomenclature Each record of a linked list is often called an 'element' or 'node'. The field of each node that contains the address of the next node is usually called the 'next link' or 'next pointer'. The remaining fields are known as the 'data', 'information', 'value', 'cargo', or 'payload' fields. The 'head' of a list is its first node. The 'tail' of a list may refer either to the rest of the list after the head, or to the last node in the list. In Lisp and some derived languages, the next node may be called the 'cdr' (pronounced could-er) of the list, while the payload of the head node may be called the 'car'. Singly linked list Singly linked lists contain nodes which have a data field as well as 'next' field, which points to the next node in line of nodes. Operations that can be performed on singly linked lists include insertion, deletion and traversal. The following code demonstrates how to add a new node with data "value" to the end of a singly linked list:node addNode(node head, int value) { node temp, p; // declare two nodes temp and p temp = createNode(); // assume createNode creates a new node with data = 0 and next pointing to NULL. temp->data = value; // add element's value to data part of node if (head == NULL) { head = temp; // when linked list is empty } else { p = head; // assign head to p while (p->next != NULL) { p = p->next; // traverse the list until p is the last node. The last node always points to NULL. } p->next = temp; // Point the previous last node to the new node created. } return head; } Doubly linked list In a 'doubly linked list', each node contains, besides the next-node link, a second link field pointing to the 'previous' node in the sequence. The two links may be called 'forward('s') and 'backwards', or 'next' and 'prev'('previous'). A technique known as XOR-linking allows a doubly linked list to be implemented using a single link field in each node. However, this technique requires the ability to do bit operations on addresses, and therefore may not be available in some high-level languages. Many modern operating systems use doubly linked lists to maintain references to active processes, threads, and other dynamic objects. A common strategy for rootkits to evade detection is to unlink themselves from these lists. Multiply linked list In a 'multiply linked list', each node contains two or more link fields, each field being used to connect the same set of data records in a different order of same set (e.g., by name, by department, by date of birth, etc.). While doubly linked lists can be seen as special cases of multiply linked list, the fact that the two and more orders are opposite to each other leads to simpler and more efficient algorithms, so they are usually treated as a separate case. Circular linked list In the last node of a list, the link field often contains a null reference, a special value is used to indicate the lack of further nodes. A less common convention is to make it point to the first node of the list; in that case, the list is said to be 'circular' or 'circularly linked'; otherwise, it is said to be 'open' or 'linear'. It is a list where the last pointer points to the first node. In the case of a circular doubly linked list, the first node also points to the last node of the list. Sentinel nodes In some implementations an extra 'sentinel' or 'dummy' node may be added before the first data record or after the last one. This convention simplifies and accelerates some list-handling algorithms, by ensuring that all links can be safely dereferenced and that every list (even one that contains no data elements) always has a "first" and "last" node. Empty lists An empty list is a list that contains no data records. This is usually the same as saying that it has zero nodes. If sentinel nodes are being used, the list is usually said to be empty when it has only sentinel nodes. Hash linking The link fields need not be physically part of the nodes. If the data records are stored in an array and referenced by their indices, the link field may be stored in a separate array with the same indices as the data records. List handles Since a reference to the first node gives access to the whole list, that reference is often called the 'address', 'pointer', or 'handle' of the list. Algorithms that manipulate linked lists usually get such handles to the input lists and return the handles to the resulting lists. In fact, in the context of such algorithms, the word "list" often means "list handle". In some situations, however, it may be convenient to refer to a list by a handle that consists of two links, pointing to its first and last nodes. Combining alternatives The alternatives listed above may be arbitrarily combined in almost every way, so one may have circular doubly linked lists without sentinels, circular singly linked lists with sentinels, etc. Tradeoffs As with most choices in computer programming and design, no method is well suited to all circumstances. A linked list data structure might work well in one case, but cause problems in another. This is a list of some of the common tradeoffs involving linked list structures. Linked lists vs. dynamic arrays A dynamic array is a data structure that allocates all elements contiguously in memory, and keeps a count of the current number of elements. If the space reserved for the dynamic array is exceeded, it is reallocated and (possibly) copied, which is an expensive operation. Linked lists have several advantages over dynamic arrays. Insertion or deletion of an element at a specific point of a list, assuming that we have indexed a pointer to the node (before the one to be removed, or before the insertion point) already, is a constant-time operation (otherwise without this reference it is O(n)), whereas insertion in a dynamic array at random locations will require moving half of the elements on average, and all the elements in the worst case. While one can "delete" an element from an array in constant time by somehow marking its slot as "vacant", this causes fragmentation that impedes the performance of iteration. Moreover, arbitrarily many elements may be inserted into a linked list, limited only by the total memory available; while a dynamic array will eventually fill up its underlying array data structure and will have to reallocate—an expensive operation, one that may not even be possible if memory is fragmented, although the cost of reallocation can be averaged over insertions, and the cost of an insertion due to reallocation would still be amortized O(1). This helps with appending elements at the array's end, but inserting into (or removing from) middle positions still carries prohibitive costs due to data moving to maintain contiguity. An array from which many elements are removed may also have to be resized in order to avoid wasting too much space. On the other hand, dynamic arrays (as well as fixed-size array data structures) allow constant-time random access, while linked lists allow only sequential access to elements. Singly linked lists, in fact, can be easily traversed in only one direction. This makes linked lists unsuitable for applications where it's useful to look up an element by its index quickly, such as heapsort. Sequential access on arrays and dynamic arrays is also faster than on linked lists on many machines, because they have optimal locality of reference and thus make good use of data caching. Another disadvantage of linked lists is the extra storage needed for references, which often makes them impractical for lists of small data items such as characters or boolean values, because the storage overhead for the links may exceed by a factor of two or more the size of the data. In contrast, a dynamic array requires only the space for the data itself (and a very small amount of control data). It can also be slow, and with a naïve allocator, wasteful, to allocate memory separately for each new element, a problem generally solved using memory pools. Some hybrid solutions try to combine the advantages of the two representations. Unrolled linked lists store several elements in each list node, increasing cache performance while decreasing memory overhead for references. CDR coding does both these as well, by replacing references with the actual data referenced, which extends off the end of the referencing record. A good example that highlights the pros and cons of using dynamic arrays vs. linked lists is by implementing a program that resolves the Josephus problem. The Josephus problem is an election method that works by having a group of people stand in a circle. Starting at a predetermined person, one may count around the circle n times. Once the nth person is reached, one should remove them from the circle and have the members close the circle. The process is repeated until only one person is left. That person wins the election. This shows the strengths and weaknesses of a linked list vs. a dynamic array, because if the people are viewed as connected nodes in a circular linked list, then it shows how easily the linked list is able to delete nodes (as it only has to rearrange the links to the different nodes). However, the linked list will be poor at finding the next person to remove and will need to search through the list until it finds that person. A dynamic array, on the other hand, will be poor at deleting nodes (or elements) as it cannot remove one node without individually shifting all the elements up the list by one. However, it is exceptionally easy to find the nth person in the circle by directly referencing them by their position in the array. The list ranking problem concerns the efficient conversion of a linked list representation into an array. Although trivial for a conventional computer, solving this problem by a parallel algorithm is complicated and has been the subject of much research. A balanced tree has similar memory access patterns and space overhead to a linked list while permitting much more efficient indexing, taking O(log n) time instead of O(n) for a random access. However, insertion and deletion operations are more expensive due to the overhead of tree manipulations to maintain balance. Schemes exist for trees to automatically maintain themselves in a balanced state: AVL trees or red–black trees. Singly linked linear lists vs. other lists While doubly linked and circular lists have advantages over singly linked linear lists, linear lists offer some advantages that make them preferable in some situations. A singly linked linear list is a recursive data structure, because it contains a pointer to a smaller object of the same type. For that reason, many operations on singly linked linear lists (such as merging two lists, or enumerating the elements in reverse order) often have very simple recursive algorithms, much simpler than any solution using iterative commands. While those recursive solutions can be adapted for doubly linked and circularly linked lists, the procedures generally need extra arguments and more complicated base cases. Linear singly linked lists also allow tail-sharing, the use of a common final portion of sub-list as the terminal portion of two different lists. In particular, if a new node is added at the beginning of a list, the former list remains available as the tail of the new one—a simple example of a persistent data structure. Again, this is not true with the other variants: a node may never belong to two different circular or doubly linked lists. In particular, end-sentinel nodes can be shared among singly linked non-circular lists. The same end-sentinel node may be used for every such list. In Lisp, for example, every proper list ends with a link to a special node, denoted by nil or (), whose CAR and CDR links point to itself. Thus a Lisp procedure can safely take the CAR or CDR of any list. The advantages of the fancy variants are often limited to the complexity of the algorithms, not in their efficiency. A circular list, in particular, can usually be emulated by a linear list together with two variables that point to the first and last nodes, at no extra cost. Doubly linked vs. singly linked Double-linked lists require more space per node (unless one uses XOR-linking), and their elementary operations are more expensive; but they are often easier to manipulate because they allow fast and easy sequential access to the list in both directions. In a doubly linked list, one can insert or delete a node in a constant number of operations given only that node's address. To do the same in a singly linked list, one must have the address of the pointer to that node, which is either the handle for the whole list (in case of the first node) or the link field in the previous node. Some algorithms require access in both directions. On the other hand, doubly linked lists do not allow tail-sharing and cannot be used as persistent data structures. Circularly linked vs. linearly linked A circularly linked list may be a natural option to represent arrays that are naturally circular, e.g. the corners of a polygon, a pool of buffers that are used and released in FIFO ("first in, first out") order, or a set of processes that should be time-shared in round-robin order. In these applications, a pointer to any node serves as a handle to the whole list. With a circular list, a pointer to the last node gives easy access also to the first node, by following one link. Thus, in applications that require access to both ends of the list (e.g., in the implementation of a queue), a circular structure allows one to handle the structure by a single pointer, instead of two. A circular list can be split into two circular lists, in constant time, by giving the addresses of the last node of each piece. The operation consists in swapping the contents of the link fields of those two nodes. Applying the same operation to any two nodes in two distinct lists joins the two list into one. This property greatly simplifies some algorithms and data structures, such as the quad-edge and face-edge. The simplest representation for an empty circular list (when such a thing makes sense) is a null pointer, indicating that the list has no nodes. Without this choice, many algorithms have to test for this special case, and handle it separately. By contrast, the use of null to denote an empty linear list is more natural and often creates fewer special cases. For some applications, it can be useful to use singly linked lists that can vary between being circular and being linear, or even circular with a linear initial segment. Algorithms for searching or otherwise operating on these have to take precautions to avoid accidentally entering an endless loop. One usual method is to have a second pointer walking the list at half or double the speed, and if both pointers meet at the same node, you know you found a cycle. Using sentinel nodes Sentinel node may simplify certain list operations, by ensuring that the next or previous nodes exist for every element, and that even empty lists have at least one node. One may also use a sentinel node at the end of the list, with an appropriate data field, to eliminate some end-of-list tests. For example, when scanning the list looking for a node with a given value x, setting the sentinel's data field to x makes it unnecessary to test for end-of-list inside the loop. Another example is the merging two sorted lists: if their sentinels have data fields set to +∞, the choice of the next output node does not need special handling for empty lists. However, sentinel nodes use up extra space (especially in applications that use many short lists), and they may complicate other operations (such as the creation of a new empty list). However, if the circular list is used merely to simulate a linear list, one may avoid some of this complexity by adding a single sentinel node to every list, between the last and the first data nodes. With this convention, an empty list consists of the sentinel node alone, pointing to itself via the next-node link. The list handle should then be a pointer to the last data node, before the sentinel, if the list is not empty; or to the sentinel itself, if the list is empty. The same trick can be used to simplify the handling of a doubly linked linear list, by turning it into a circular doubly linked list with a single sentinel node. However, in this case, the handle should be a single pointer to the dummy node itself. Linked list operations When manipulating linked lists in-place, care must be taken to not use values that you have invalidated in previous assignments. This makes algorithms for inserting or deleting linked list nodes somewhat subtle. This section gives pseudocode for adding or removing nodes from singly, doubly, and circularly linked lists in-place. Throughout we will use null to refer to an end-of-list marker or sentinel, which may be implemented in a number of ways. Linearly linked lists Singly linked lists Our node data structure will have two fields. We also keep a variable firstNode which always points to the first node in the list, or is null for an empty list. record Node { data; // The data being stored in the node Node next // A reference to the next node, null for last node } record List { Node firstNode // points to first node of list; null for empty list } Traversal of a singly linked list is simple, beginning at the first node and following each next link until we come to the end: node := list.firstNode while node not null (do something with node.data) node := node.next The following code inserts a node after an existing node in a singly linked list. The diagram shows how it works. Inserting a node before an existing one cannot be done directly; instead, one must keep track of the previous node and insert a node after it. function insertAfter(Node node, Node newNode) // insert newNode after node newNode.next := node.next node.next := newNode Inserting at the beginning of the list requires a separate function. This requires updating firstNode. function insertBeginning(List list, Node newNode) // insert node before current first node newNode.next := list.firstNode list.firstNode := newNode Similarly, we have functions for removing the node after a given node, and for removing a node from the beginning of the list. The diagram demonstrates the former. To find and remove a particular node, one must again keep track of the previous element. function removeAfter(Node node) // remove node past this one obsoleteNode := node.next node.next := node.next.next destroy obsoleteNode function removeBeginning(List list) // remove first node obsoleteNode := list.firstNode list.firstNode := list.firstNode.next // point past deleted node destroy obsoleteNode Notice that removeBeginning() sets list.firstNode to null when removing the last node in the list. Since we can't iterate backwards, efficient insertBefore or removeBefore operations are not possible. Inserting to a list before a specific node requires traversing the list, which would have a worst case running time of O(n). Appending one linked list to another can be inefficient unless a reference to the tail is kept as part of the List structure, because we must traverse the entire first list in order to find the tail, and then append the second list to this. Thus, if two linearly linked lists are each of length , list appending has asymptotic time complexity of . In the Lisp family of languages, list appending is provided by the append procedure. Many of the special cases of linked list operations can be eliminated by including a dummy element at the front of the list. This ensures that there are no special cases for the beginning of the list and renders both insertBeginning() and removeBeginning() unnecessary. In this case, the first useful data in the list will be found at list.firstNode.next. Circularly linked list In a circularly linked list, all nodes are linked in a continuous circle, without using null. For lists with a front and a back (such as a queue), one stores a reference to the last node in the list. The next node after the last node is the first node. Elements can be added to the back of the list and removed from the front in constant time. Circularly linked lists can be either singly or doubly linked. Both types of circularly linked lists benefit from the ability to traverse the full list beginning at any given node. This often allows us to avoid storing firstNode and lastNode, although if the list may be empty we need a special representation for the empty list, such as a lastNode variable which points to some node in the list or is null if it's empty; we use such a lastNode here. This representation significantly simplifies adding and removing nodes with a non-empty list, but empty lists are then a special case. Algorithms Assuming that someNode is some node in a non-empty circular singly linked list, this code iterates through that list starting with someNode: function iterate(someNode) if someNode ≠ null node := someNode do do something with node.value node := node.next while node ≠ someNode Notice that the test "while node ≠ someNode" must be at the end of the loop. If the test was moved to the beginning of the loop, the procedure would fail whenever the list had only one node. This function inserts a node "newNode" into a circular linked list after a given node "node". If "node" is null, it assumes that the list is empty. function insertAfter(Node node, Node newNode) if node = null // assume list is empty newNode.next := newNode else newNode.next := node.next node.next := newNode update lastNode variable if necessary Suppose that "L" is a variable pointing to the last node of a circular linked list (or null if the list is empty). To append "newNode" to the end of the list, one may do insertAfter(L, newNode) L := newNode To insert "newNode" at the beginning of the list, one may do insertAfter(L, newNode) if L = null L := newNode This function inserts a value "newVal" before a given node "node" in O(1) time. We create a new node between "node" and the next node, and then put the value of "node" into that new node, and put "newVal" in "node". Thus, a singly linked circularly linked list with only a firstNode variable can both insert to the front and back in O(1) time. function insertBefore(Node node, newVal) if node = null // assume list is empty newNode := new Node(data:=newVal, next:=newNode) else newNode := new Node(data:=node.data, next:=node.next) node.data := newVal node.next := newNode update firstNode variable if necessary This function removes a non-null node from a list of size greater than 1 in O(1) time. It copies data from the next node into the node, and then sets the node's next pointer to skip over the next node. function remove(Node node) if node ≠ null and size of list > 1 removedData := node.data node.data := node.next.data node.next = node.next.next return removedData Linked lists using arrays of nodes Languages that do not support any type of reference can still create links by replacing pointers with array indices. The approach is to keep an array of records, where each record has integer fields indicating the index of the next (and possibly previous) node in the array. Not all nodes in the array need be used. If records are also not supported, parallel arrays can often be used instead. As an example, consider the following linked list record that uses arrays instead of pointers: record Entry { integer next; // index of next entry in array integer prev; // previous entry (if double-linked) string name; real balance; } A linked list can be built by creating an array of these structures, and an integer variable to store the index of the first element. integer listHead Entry Records[1000] Links between elements are formed by placing the array index of the next (or previous) cell into the Next or Prev field within a given element. For example: In the above example, ListHead would be set to 2, the location of the first entry in the list. Notice that entry 3 and 5 through 7 are not part of the list. These cells are available for any additions to the list. By creating a ListFree integer variable, a free list could be created to keep track of what cells are available. If all entries are in use, the size of the array would have to be increased or some elements would have to be deleted before new entries could be stored in the list. The following code would traverse the list and display names and account balance: i := listHead while i ≥ 0 // loop through the list print i, Records[i].name, Records[i].balance // print entry i := Records[i].next When faced with a choice, the advantages of this approach include: The linked list is relocatable, meaning it can be moved about in memory at will, and it can also be quickly and directly serialized for storage on disk or transfer over a network. Especially for a small list, array indexes can occupy significantly less space than a full pointer on many architectures. Locality of reference can be improved by keeping the nodes together in memory and by periodically rearranging them, although this can also be done in a general store. Naïve dynamic memory allocators can produce an excessive amount of overhead storage for each node allocated; almost no allocation overhead is incurred per node in this approach. Seizing an entry from a pre-allocated array is faster than using dynamic memory allocation for each node, since dynamic memory allocation typically requires a search for a free memory block of the desired size. This approach has one main disadvantage, however: it creates and manages a private memory space for its nodes. This leads to the following issues: It increases complexity of the implementation. Growing a large array when it is full may be difficult or impossible, whereas finding space for a new linked list node in a large, general memory pool may be easier. Adding elements to a dynamic array will occasionally (when it is full) unexpectedly take linear (O(n)) instead of constant time (although it's still an amortized constant). Using a general memory pool leaves more memory for other data if the list is smaller than expected or if many nodes are freed. For these reasons, this approach is mainly used for languages that do not support dynamic memory allocation. These disadvantages are also mitigated if the maximum size of the list is known at the time the array is created. Language support Many programming languages such as Lisp and Scheme have singly linked lists built in. In many functional languages, these lists are constructed from nodes, each called a cons or cons cell. The cons has two fields: the car, a reference to the data for that node, and the cdr, a reference to the next node. Although cons cells can be used to build other data structures, this is their primary purpose. In languages that support abstract data types or templates, linked list ADTs or templates are available for building linked lists. In other languages, linked lists are typically built using references together with records. Internal and external storage When constructing a linked list, one is faced with the choice of whether to store the data of the list directly in the linked list nodes, called internal storage, or merely to store a reference to the data, called external storage. Internal storage has the advantage of making access to the data more efficient, requiring less storage overall, having better locality of reference, and simplifying memory management for the list (its data is allocated and deallocated at the same time as the list nodes). External storage, on the other hand, has the advantage of being more generic, in that the same data structure and machine code can be used for a linked list no matter what the size of the data is. It also makes it easy to place the same data in multiple linked lists. Although with internal storage the same data can be placed in multiple lists by including multiple next references in the node data structure, it would then be necessary to create separate routines to add or delete cells based on each field. It is possible to create additional linked lists of elements that use internal storage by using external storage, and having the cells of the additional linked lists store references to the nodes of the linked list containing the data. In general, if a set of data structures needs to be included in linked lists, external storage is the best approach. If a set of data structures need to be included in only one linked list, then internal storage is slightly better, unless a generic linked list package using external storage is available. Likewise, if different sets of data that can be stored in the same data structure are to be included in a single linked list, then internal storage would be fine. Another approach that can be used with some languages involves having different data structures, but all have the initial fields, including the next (and prev if double linked list) references in the same location. After defining separate structures for each type of data, a generic structure can be defined that contains the minimum amount of data shared by all the other structures and contained at the top (beginning) of the structures. Then generic routines can be created that use the minimal structure to perform linked list type operations, but separate routines can then handle the specific data. This approach is often used in message parsing routines, where several types of messages are received, but all start with the same set of fields, usually including a field for message type. The generic routines are used to add new messages to a queue when they are received, and remove them from the queue in order to process the message. The message type field is then used to call the correct routine to process the specific type of message. Example of internal and external storage Suppose you wanted to create a linked list of families and their members. Using internal storage, the structure might look like the following: record member { // member of a family member next; string firstName; integer age; } record family { // the family itself family next; string lastName; string address; member members // head of list of members of this family } To print a complete list of families and their members using internal storage, we could write: aFamily := Families // start at head of families list while aFamily ≠ null // loop through list of families print information about family aMember := aFamily.members // get head of list of this family's members while aMember ≠ null // loop through list of members print information about member aMember := aMember.next aFamily := aFamily.next Using external storage, we would create the following structures: record node { // generic link structure node next; pointer data // generic pointer for data at node } record member { // structure for family member string firstName; integer age } record family { // structure for family string lastName; string address; node members // head of list of members of this family } To print a complete list of families and their members using external storage, we could write: famNode := Families // start at head of families list while famNode ≠ null // loop through list of families aFamily := (family) famNode.data // extract family from node print information about family memNode := aFamily.members // get list of family members while memNode ≠ null // loop through list of members aMember := (member)memNode.data // extract member from node print information about member memNode := memNode.next famNode := famNode.next Notice that when using external storage, an extra step is needed to extract the record from the node and cast it into the proper data type. This is because both the list of families and the list of members within the family are stored in two linked lists using the same data structure (node), and this language does not have parametric types. As long as the number of families that a member can belong to is known at compile time, internal storage works fine. If, however, a member needed to be included in an arbitrary number of families, with the specific number known only at run time, external storage would be necessary. Speeding up search Finding a specific element in a linked list, even if it is sorted, normally requires O(n) time (linear search). This is one of the primary disadvantages of linked lists over other data structures. In addition to the variants discussed above, below are two simple ways to improve search time. In an unordered list, one simple heuristic for decreasing average search time is the move-to-front heuristic'', which simply moves an element to the beginning of the list once it is found. This scheme, handy for creating simple caches, ensures that the most recently used items are also the quickest to find again. Another common approach is to "index" a linked list using a more efficient external data structure. For example, one can build a red–black tree or hash table whose elements are references to the linked list nodes. Multiple such indexes can be built on a single list. The disadvantage is that these indexes may need to be updated each time a node is added or removed (or at least, before that index is used again). Random-access lists A random-access list is a list with support for fast random access to read or modify any element in the list. One possible implementation is a skew binary random-access list using the skew binary number system, which involves a list of trees with special properties; this allows worst-case constant time head/cons operations, and worst-case logarithmic time random access to an element by index. Random-access lists can be implemented as persistent data structures. Random-access lists can be viewed as immutable linked lists in that they likewise support the same O(1) head and tail operations. A simple extension to random-access lists is the min-list, which provides an additional operation that yields the minimum element in the entire list in constant time (without mutation complexities). Related data structures Both stacks and queues are often implemented using linked lists, and simply restrict the type of operations which are supported. The skip list is a linked list augmented with layers of pointers for quickly jumping over large numbers of elements, and then descending to the next layer. This process continues down to the bottom layer, which is the actual list. A binary tree can be seen as a type of linked list where the elements are themselves linked lists of the same nature. The result is that each node may include a reference to the first node of one or two other linked lists, which, together with their contents, form the subtrees below that node. An unrolled linked list is a linked list in which each node contains an array of data values. This leads to improved cache performance, since more list elements are contiguous in memory, and reduced memory overhead, because less metadata needs to be stored for each element of the list. A hash table may use linked lists to store the chains of items that hash to the same position in the hash table. A heap shares some of the ordering properties of a linked list, but is almost always implemented using an array. Instead of references from node to node, the next and previous data indexes are calculated using the current data's index. A self-organizing list rearranges its nodes based on some heuristic which reduces search times for data retrieval by keeping commonly accessed nodes at the head of the list. Notes References Further reading External links Description from the Dictionary of Algorithms and Data Structures Introduction to Linked Lists, Stanford University Computer Science Library Linked List Problems, Stanford University Computer Science Library Open Data Structures - Chapter 3 - Linked Lists, Pat Morin Patent for the idea of having nodes which are in several linked lists simultaneously (note that this technique was widely used for many decades before the patent was granted) Articles with example C code	[ 0.0972234457731247, 0.23701630532741547, -0.2650934159755707, 0.5861301422119141, 0.018740009516477585, -0.010183506645262241, -0.36933815479278564, 0.12009621411561966, -0.6198673844337463, -0.4707625210285187, -0.4886469542980194, -0.10678120702505112, -0.4384632706642151, 0.378113687038...
18168	https://en.wikipedia.org/wiki/Logic%20gate	Logic gate	A logic gate is an idealized model of computation or a physical electronic device implementing a Boolean function, a logical operation performed on one or more binary inputs that produces a single binary output. Depending on the context, the term may refer to an ideal logic gate, one that has for instance zero rise time and unlimited fan-out, or it may refer to a non-ideal physical device (see Ideal and real op-amps for comparison). Logic gates are primarily implemented using diodes or transistors acting as electronic switches, but can also be constructed using vacuum tubes, electromagnetic relays (relay logic), fluidic logic, pneumatic logic, optics, molecules, or even mechanical elements. With amplification, logic gates can be cascaded in the same way that Boolean functions can be composed, allowing the construction of a physical model of all of Boolean logic, and therefore, all of the algorithms and mathematics that can be described with Boolean logic. Logic circuits include such devices as multiplexers, registers, arithmetic logic units (ALUs), and computer memory, all the way up through complete microprocessors, which may contain more than 100 million gates. In modern practice, most gates are made from MOSFETs (metal–oxide–semiconductor field-effect transistors). Compound logic gates AND-OR-Invert (AOI) and OR-AND-Invert (OAI) are often employed in circuit design because their construction using MOSFETs is simpler and more efficient than the sum of the individual gates. In reversible logic, Toffoli gates are used. Electronic gates A functionally complete logic system may be composed of relays, valves (vacuum tubes), or transistors. The simplest family of logic gates uses bipolar transistors, and is called resistor–transistor logic (RTL). Unlike simple diode logic gates (which do not have a gain element), RTL gates can be cascaded indefinitely to produce more complex logic functions. RTL gates were used in early integrated circuits. For higher speed and better density, the resistors used in RTL were replaced by diodes resulting in diode–transistor logic (DTL). Transistor–transistor logic (TTL) then supplanted DTL. As integrated circuits became more complex, bipolar transistors were replaced with smaller field-effect transistors (MOSFETs); see PMOS and NMOS. To reduce power consumption still further, most contemporary chip implementations of digital systems now use CMOS logic. CMOS uses complementary (both n-channel and p-channel) MOSFET devices to achieve a high speed with low power dissipation. For small-scale logic, designers now use prefabricated logic gates from families of devices such as the TTL 7400 series by Texas Instruments, the CMOS 4000 series by RCA, and their more recent descendants. Increasingly, these fixed-function logic gates are being replaced by programmable logic devices, which allow designers to pack many mixed logic gates into a single integrated circuit. The field-programmable nature of programmable logic devices such as FPGAs has reduced the 'hard' property of hardware; it is now possible to change the logic design of a hardware system by reprogramming some of its components, thus allowing the features or function of a hardware implementation of a logic system to be changed. Other types of logic gates include, but are not limited to: Electronic logic gates differ significantly from their relay-and-switch equivalents. They are much faster, consume much less power, and are much smaller (all by a factor of a million or more in most cases). Also, there is a fundamental structural difference. The switch circuit creates a continuous metallic path for current to flow (in either direction) between its input and its output. The semiconductor logic gate, on the other hand, acts as a high-gain voltage amplifier, which sinks a tiny current at its input and produces a low-impedance voltage at its output. It is not possible for current to flow between the output and the input of a semiconductor logic gate. Another important advantage of standardized integrated circuit logic families, such as the 7400 and 4000 families, is that they can be cascaded. This means that the output of one gate can be wired to the inputs of one or several other gates, and so on. Systems with varying degrees of complexity can be built without great concern of the designer for the internal workings of the gates, provided the limitations of each integrated circuit are considered. The output of one gate can only drive a finite number of inputs to other gates, a number called the 'fan-out limit'. Also, there is always a delay, called the 'propagation delay', from a change in input of a gate to the corresponding change in its output. When gates are cascaded, the total propagation delay is approximately the sum of the individual delays, an effect which can become a problem in high-speed circuits. Additional delay can be caused when many inputs are connected to an output, due to the distributed capacitance of all the inputs and wiring and the finite amount of current that each output can provide. History and development The binary number system was refined by Gottfried Wilhelm Leibniz (published in 1705), influenced by the ancient I Chings binary system. Leibniz established that using the binary system combined the principles of arithmetic and logic. In an 1886 letter, Charles Sanders Peirce described how logical operations could be carried out by electrical switching circuits. Eventually, vacuum tubes replaced relays for logic operations. Lee De Forest's modification, in 1907, of the Fleming valve can be used as a logic gate. Ludwig Wittgenstein introduced a version of the 16-row truth table as proposition 5.101 of Tractatus Logico-Philosophicus (1921). Walther Bothe, inventor of the coincidence circuit, got part of the 1954 Nobel Prize in physics, for the first modern electronic AND gate in 1924. Konrad Zuse designed and built electromechanical logic gates for his computer Z1 (from 1935 to 1938). From 1934 to 1936, NEC engineer Akira Nakashima, Claude Shannon and Viktor Shetakov introduced switching circuit theory in a series of papers showing that two-valued Boolean algebra, which they discovered independently, can describe the operation of switching circuits. Using this property of electrical switches to implement logic is the fundamental concept that underlies all electronic digital computers. Switching circuit theory became the foundation of digital circuit design, as it became widely known in the electrical engineering community during and after World War II, with theoretical rigor superseding the ad hoc methods that had prevailed previously. Metal-oxide-semiconductor (MOS) devices in the forms of PMOS and NMOS were demonstrated by Bell Labs engineers Mohamed M. Atalla and Dawon Kahng in 1960. Both types were later combined and adapted into complementary MOS (CMOS) logic by Chih-Tang Sah and Frank Wanlass at Fairchild Semiconductor in 1963. Active research is taking place in molecular logic gates. Symbols There are two sets of symbols for elementary logic gates in common use, both defined in ANSI/IEEE Std 91-1984 and its supplement ANSI/IEEE Std 91a-1991. The "distinctive shape" set, based on traditional schematics, is used for simple drawings and derives from United States Military Standard MIL-STD-806 of the 1950s and 1960s. It is sometimes unofficially described as "military", reflecting its origin. The "rectangular shape" set, based on ANSI Y32.14 and other early industry standards as later refined by IEEE and IEC, has rectangular outlines for all types of gate and allows representation of a much wider range of devices than is possible with the traditional symbols. The IEC standard, IEC 60617-12, has been adopted by other standards, such as EN 60617-12:1999 in Europe, BS EN 60617-12:1999 in the United Kingdom, and DIN EN 60617-12:1998 in Germany. The mutual goal of IEEE Std 91-1984 and IEC 60617-12 was to provide a uniform method of describing the complex logic functions of digital circuits with schematic symbols. These functions were more complex than simple AND and OR gates. They could be medium scale circuits such as a 4-bit counter to a large scale circuit such as a microprocessor. IEC 617-12 and its successor IEC 60617-12 do not explicitly show the "distinctive shape" symbols, but do not prohibit them. These are, however, shown in ANSI/IEEE 91 (and 91a) with this note: "The distinctive-shape symbol is, according to IEC Publication 617, Part 12, not preferred, but is not considered to be in contradiction to that standard." IEC 60617-12 correspondingly contains the note (Section 2.1) "Although non-preferred, the use of other symbols recognized by official national standards, that is distinctive shapes in place of symbols [list of basic gates], shall not be considered to be in contradiction with this standard. Usage of these other symbols in combination to form complex symbols (for example, use as embedded symbols) is discouraged." This compromise was reached between the respective IEEE and IEC working groups to permit the IEEE and IEC standards to be in mutual compliance with one another. A third style of symbols, DIN 40700 (1976), was in use in Europe and is still widely used in European academia, see the logic table in German Wikipedia. In the 1980s, schematics were the predominant method to design both circuit boards and custom ICs known as gate arrays. Today custom ICs and the field-programmable gate array are typically designed with Hardware Description Languages (HDL) such as Verilog or VHDL. Truth tables Output comparison of 1-input logic gates. Output comparison of 2-input logic gates. Universal logic gates Charles Sanders Peirce (during 1880–81) showed that NOR gates alone (or alternatively NAND gates alone) can be used to reproduce the functions of all the other logic gates, but his work on it was unpublished until 1933. The first published proof was by Henry M. Sheffer in 1913, so the NAND logical operation is sometimes called Sheffer stroke; the logical NOR is sometimes called Peirce's arrow. Consequently, these gates are sometimes called universal logic gates. De Morgan equivalent symbols By use of De Morgan's laws, an AND function is identical to an OR function with negated inputs and outputs. Likewise, an OR function is identical to an AND function with negated inputs and outputs. A NAND gate is equivalent to an OR gate with negated inputs, and a NOR gate is equivalent to an AND gate with negated inputs. This leads to an alternative set of symbols for basic gates that use the opposite core symbol (AND or OR) but with the inputs and outputs negated. Use of these alternative symbols can make logic circuit diagrams much clearer and help to show accidental connection of an active high output to an active low input or vice versa. Any connection that has logic negations at both ends can be replaced by a negationless connection and a suitable change of gate or vice versa. Any connection that has a negation at one end and no negation at the other can be made easier to interpret by instead using the De Morgan equivalent symbol at either of the two ends. When negation or polarity indicators on both ends of a connection match, there is no logic negation in that path (effectively, bubbles "cancel"), making it easier to follow logic states from one symbol to the next. This is commonly seen in real logic diagrams – thus the reader must not get into the habit of associating the shapes exclusively as OR or AND shapes, but also take into account the bubbles at both inputs and outputs in order to determine the "true" logic function indicated. A De Morgan symbol can show more clearly a gate's primary logical purpose and the polarity of its nodes that are considered in the "signaled" (active, on) state. Consider the simplified case where a two-input NAND gate is used to drive a motor when either of its inputs are brought low by a switch. The "signaled" state (motor on) occurs when either one OR the other switch is on. Unlike a regular NAND symbol, which suggests AND logic, the De Morgan version, a two negative-input OR gate, correctly shows that OR is of interest. The regular NAND symbol has a bubble at the output and none at the inputs (the opposite of the states that will turn the motor on), but the De Morgan symbol shows both inputs and output in the polarity that will drive the motor. De Morgan's theorem is most commonly used to implement logic gates as combinations of only NAND gates, or as combinations of only NOR gates, for economic reasons. Data storage Logic gates can also be used to store data. A storage element can be constructed by connecting several gates in a "latch" circuit. More complicated designs that use clock signals and that change only on a rising or falling edge of the clock are called edge-triggered "flip-flops". Formally, a flip-flop is called a bistable circuit, because it has two stable states which it can maintain indefinitely. The combination of multiple flip-flops in parallel, to store a multiple-bit value, is known as a register. When using any of these gate setups the overall system has memory; it is then called a sequential logic system since its output can be influenced by its previous state(s), i.e. by the sequence of input states. In contrast, the output from combinational logic is purely a combination of its present inputs, unaffected by the previous input and output states. These logic circuits are known as computer memory. They vary in performance, based on factors of speed, complexity, and reliability of storage, and many different types of designs are used based on the application. Three-state logic gates A three-state logic gate is a type of logic gate that can have three different outputs: high (H), low (L) and high-impedance (Z). The high-impedance state plays no role in the logic, which is strictly binary. These devices are used on buses of the CPU to allow multiple chips to send data. A group of three-states driving a line with a suitable control circuit is basically equivalent to a multiplexer, which may be physically distributed over separate devices or plug-in cards. In electronics, a high output would mean the output is sourcing current from the positive power terminal (positive voltage). A low output would mean the output is sinking current to the negative power terminal (zero voltage). High impedance would mean that the output is effectively disconnected from the circuit. Manufacturing Since the 1990s, most logic gates are made in CMOS (complementary metal oxide semiconductor) technology that uses both NMOS and PMOS transistors. Often millions of logic gates are packaged in a single integrated circuit. Early techniques Non-electronic implementations are varied, though few of them are used in practical applications. Many early electromechanical digital computers, such as the Harvard Mark I, were built from relay logic gates, using electro-mechanical relays. Logic gates can be made using pneumatic devices, such as the Sorteberg relay or mechanical logic gates, including on a molecular scale. Logic gates have been made out of DNA (see DNA nanotechnology) and used to create a computer called MAYA (see MAYA-II). Logic gates can be made from quantum mechanical effects, see quantum logic gate. Photonic logic gates use nonlinear optical effects. In principle any method that leads to a gate that is functionally complete (for example, either a NOR or a NAND gate) can be used to make any kind of digital logic circuit. Note that the use of 3-state logic for bus systems is not needed, and can be replaced by digital multiplexers, which can be built using only simple logic gates (such as NAND gates, NOR gates, or AND and OR gates). Logic families There are several logic families with different characteristics (power consumption, speed, cost, size) such as: RDL (resistor–diode logic), RTL (resistor-transistor logic), DTL (diode–transistor logic), TTL (transistor–transistor logic) and CMOS. There are also sub-variants, e.g. standard CMOS logic vs. advanced types using still CMOS technology, but with some optimizations for avoiding loss of speed due to slower PMOS transistors. See also And-inverter graph Boolean algebra topics Boolean function Digital circuit Espresso heuristic logic minimizer Fan-out Field-programmable gate array (FPGA) Flip-flop (electronics) Functional completeness Karnaugh map Combinational logic List of 4000 series integrated circuits List of 7400 series integrated circuits Logic family Logic level Logical graph NMOS logic Programmable Logic Controller (PLC) Programmable Logic Device (PLD) Propositional calculus Quantum logic gate Race hazard Reversible computing Truth table References Further reading External links	[ -0.15284283459186554, 0.016719063743948936, -0.43809622526168823, 0.43784719705581665, -0.16817641258239746, 0.11779644340276718, 0.013203869573771954, -0.03910694271326065, 0.06228775903582573, -0.31388089060783386, -0.5259406566619873, 0.23187905550003052, -0.49623754620552063, 0.4661766...
18171	https://en.wikipedia.org/wiki/Linear%20search	Linear search	In computer science, a linear search or sequential search is a method for finding an element within a list. It sequentially checks each element of the list until a match is found or the whole list has been searched. A linear search runs in at worst linear time and makes at most comparisons, where is the length of the list. If each element is equally likely to be searched, then linear search has an average case of comparisons, but the average case can be affected if the search probabilities for each element vary. Linear search is rarely practical because other search algorithms and schemes, such as the binary search algorithm and hash tables, allow significantly faster searching for all but short lists. Algorithm A linear search sequentially checks each element of the list until it finds an element that matches the target value. If the algorithm reaches the end of the list, the search terminates unsuccessfully. Basic algorithm Given a list of elements with values or records , and target value , the following subroutine uses linear search to find the index of the target in . Set to 0. If , the search terminates successfully; return . Increase by 1. If , go to step 2. Otherwise, the search terminates unsuccessfully. With a sentinel The basic algorithm above makes two comparisons per iteration: one to check if equals T, and the other to check if still points to a valid index of the list. By adding an extra record to the list (a sentinel value) that equals the target, the second comparison can be eliminated until the end of the search, making the algorithm faster. The search will reach the sentinel if the target is not contained within the list. Set to 0. If , go to step 4. Increase by 1 and go to step 2. If , the search terminates successfully; return . Else, the search terminates unsuccessfully. In an ordered table If the list is ordered such that , the search can establish the absence of the target more quickly by concluding the search once exceeds the target. This variation requires a sentinel that is greater than the target. Set to 0. If , go to step 4. Increase by 1 and go to step 2. If , the search terminates successfully; return . Else, the search terminates unsuccessfully. Analysis For a list with n items, the best case is when the value is equal to the first element of the list, in which case only one comparison is needed. The worst case is when the value is not in the list (or occurs only once at the end of the list), in which case n comparisons are needed. If the value being sought occurs k times in the list, and all orderings of the list are equally likely, the expected number of comparisons is For example, if the value being sought occurs once in the list, and all orderings of the list are equally likely, the expected number of comparisons is . However, if it is known that it occurs once, then at most n - 1 comparisons are needed, and the expected number of comparisons is (for example, for n = 2 this is 1, corresponding to a single if-then-else construct). Either way, asymptotically the worst-case cost and the expected cost of linear search are both O(n). Non-uniform probabilities The performance of linear search improves if the desired value is more likely to be near the beginning of the list than to its end. Therefore, if some values are much more likely to be searched than others, it is desirable to place them at the beginning of the list. In particular, when the list items are arranged in order of decreasing probability, and these probabilities are geometrically distributed, the cost of linear search is only O(1). Application Linear search is usually very simple to implement, and is practical when the list has only a few elements, or when performing a single search in an un-ordered list. When many values have to be searched in the same list, it often pays to pre-process the list in order to use a faster method. For example, one may sort the list and use binary search, or build an efficient search data structure from it. Should the content of the list change frequently, repeated re-organization may be more trouble than it is worth. As a result, even though in theory other search algorithms may be faster than linear search (for instance binary search), in practice even on medium-sized arrays (around 100 items or less) it might be infeasible to use anything else. On larger arrays, it only makes sense to use other, faster search methods if the data is large enough, because the initial time to prepare (sort) the data is comparable to many linear searches. See also Ternary search Hash table Linear search problem References Citations Works Search algorithms	[ -0.2428567260503769, 0.012654365040361881, -0.04090326279401779, 0.31096845865249634, -0.00999870803207159, 0.12981390953063965, 0.0055334013886749744, -0.0732632726430893, -0.592410683631897, -0.4053897559642792, -0.5187303423881531, 0.2697683870792389, -0.7945585250854492, 0.145484983921...
18172	https://en.wikipedia.org/wiki/Land%20mine	Land mine	A land mine is an explosive device concealed under or on the ground and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. Such a device is typically detonated automatically by way of pressure when a target steps on it or drives over it, although other detonation mechanisms are also sometimes used. A land mine may cause damage by direct blast effect, by fragments that are thrown by the blast, or by both. The use of land mines is controversial because of their potential as indiscriminate weapons. They can remain dangerous many years after a conflict has ended, harming civilians and the economy. Seventy-eight countries are contaminated with land mines and 15,000–20,000 people are killed every year while many more are injured. Approximately 80% of land mine casualties are civilians, with children as the most affected age group. Most killings occur in times of peace. With pressure from a number of campaign groups organised through the International Campaign to Ban Landmines, a global movement to prohibit their use led to the 1997 Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, also known as the Ottawa Treaty. To date, 164 nations have signed the treaty, but these do not include China, the Russian Federation, or the United States. Definition In the Anti-Personnel Mine Ban Convention (also known as the "Ottawa Treaty") and the "Protocol on Mines, Booby-Traps and Other Devices", a mine is defined as a "munition designed to be placed under, on or near the ground or other surface area and to be exploded by the presence, proximity or contact of a person or vehicle". Similar in function is the booby-trap, which the protocol defines as "any device or material which is designed, constructed or adapted to kill or injure and which functions unexpectedly when a person disturbs or approaches an apparently harmless object or performs an apparently safe act". Such actions might include opening a door or picking up an object. Normally, mines are mass-produced and placed in groups, while booby traps are improvised and deployed one at a time. Also, booby traps can be non-explosive devices such as punji sticks. Overlapping both categories is the improvised explosive device (IED), which is "a device placed or fabricated in an improvised manner incorporating explosive material, destructive, lethal, noxious, incendiary, pyrotechnic materials or chemicals designed to destroy, disfigure, distract or harass. They may incorporate military stores, but are normally devised from non-military components." Some meet the definition of mines or booby traps and are also referred to as "improvised", "artisanal" or "locally manufactured" mines. Other types of IED are remotely activated, so are not considered mines. Remotely delivered mines are dropped from aircraft or carried by devices such as artillery shells or rockets. Another type of remotely delivered explosive is the cluster munition, a device that releases several sub munitions ("bomblets") over a large area. The use, transfer, production, and stockpiling of cluster munitions is prohibited by the international CCM treaty. If bomblets do not explode, they are referred to as unexploded ordnance (UXO), along with unexploded artillery shells and other explosive devices that were not manually placed (that is, mines and booby traps are not UXOs). Explosive remnants of war (ERW) include UXOs and abandoned explosive ordnance (AXO), devices that were never used and were left behind after a conflict. Land mines are divided into two types: anti-tank mines, which are designed to disable tanks or other vehicles; and anti-personnel mines, which are designed to injure or kill people. History The history of land mines can be divided into three main phases: In the ancient world, buried spikes provided many of the same functions as modern mines. Mines using gunpowder as the explosive were used from the Ming dynasty to the American Civil War. Subsequently, high explosives were developed and used in land mines. Before explosives Some fortifications in the Roman Empire were surrounded by a series of hazards buried in the ground. These included goads, foot-long pieces of wood with iron hooks on their ends; lilia (lilies, so named after their appearance), which were pits in which sharpened logs were arranged in a five-point pattern; and abatis, fallen trees with sharpened branches facing outwards. As with modern land mines, they were "victim-operated", often concealed, and formed zones that were wide enough so that the enemy could not do much harm from outside, but were under fire (from spear throws, in this case) if they attempted to remove the obstacles. A notable use of these defenses was by Julius Caesar in the Battle of Alesia. His forces were besieging Vercingetorix, the leader of the Gauls, but Vercingetorix managed to send for reinforcements. To maintain the siege and defend against the reinforcements, Caesar formed a line of fortifications on both sides, and they played an important role in his victory. Lilies were also used by Scots against the English at the Battle of Bannockburn in 1314, and by Germans at the Battle of Passchendaele in the First World War. A more easily deployed defense used by the Romans was the caltrop, a weapon 12–15 cm across with four sharp spikes that are oriented so that when it is thrown on the ground, one spike always points up. As with modern antipersonnel mines, caltrops are designed to disable soldiers rather than kill them; they are also more effective in stopping mounted forces, who lack the advantage of being able to carefully scrutinize each step they take (though forcing foot-mounted forces to take the time to do so has benefits in and of itself). They were used by the Jin dynasty in China at the Battle of Zhongdu to slow down the advance of Genghis Khan's army; Joan of Arc was wounded by one in the Siege of Orléans; in Japan they are known as tetsu-bishu and were used by ninjas from the fourteenth century onward. Caltrops are still strung together and used as roadblocks in some modern conflicts. Gunpowder East Asia Starting in the ninth century, the Chinese began centuries of experiments that resulted in gunpowder, an explosive mixture of sulfur, charcoal and potassium nitrate. Gunpowder was first used in battle in the thirteenth century. An "enormous bomb", credited to Lou Qianxia, was used in 1277 by the Chinese at the Battle of Zhongdu, although it probably had little effect. Gunpowder was difficult to use in mines because it is hygroscopic, easily absorbing water from the atmosphere, and when wet it is no longer explosive. A 14th-century military treatise, the Huolongjing (fire dragon manual), describes hollow cast iron cannonball shells filled with gunpowder. The wad of the mine was made of hard wood, carrying three different fuses in case of defective connection to the touch hole. These fuses were long and lit by hand, so they required carefully timed calculations of enemy movements. The Huolongjing also describes land mines that were set off by enemy movement. A nine-foot length of bamboo was waterproofed by wrapping it in cowhide and covering it with oil. It was filled with compressed gunpowder and lead or iron pellets, sealed with wax and concealed in a trench. The triggering mechanism was not fully described until the early 17th century. When the enemy stepped onto hidden boards, they dislodged a pin, causing a weight to fall. A cord attached to the weight was wrapped around a drum attached to two steel wheels; when the weight fell, the wheels struck sparks against flint, igniting a set of fuses leading to multiple mines. A similar mechanism was used in the first wheellock musket in Europe as sketched by Leonardo da Vinci around 1500 AD. Another victim-operated device was the "underground sky-soaring thunder", which lured bounty hunters with halberds, pikes, and lances planted in the ground. If they pulled on one of these weapons, the butt end disturbed a bowl underneath and a slow-burning incandescent material in the bowl ignited the fuses. The fuse mechanisms for the above devices were cumbersome and unreliable. By the time Europeans arrived in China, landmines were largely forgotten. Europe and the United States At Augsburg in 1573, three centuries after the Chinese invented the first pressure-operated mine, a German military engineer by the name of Samuel Zimmermann invented the Fladdermine (flying mine). It consisted of a few pounds of black powder buried near the surface and was activated by stepping on it or tripping a wire that made a flintlock fire. Such mines were deployed on the slope in front of a fort. They were used during the Franco-Prussian War, but were probably not very effective because a flintlock does not work for long when left untended. Another device, the fougasse, was not victim-operated or mass-produced, but it was a precursor of modern fragmentation mines and the claymore mine. It consisted of a cone-shape hole with gunpowder at the bottom, covered either by rocks and scrap iron (stone fougasse) or mortar shells, similar to large black powder hand grenades (shell fougasse). It was triggered by a flintlock connected to a tripwire on the surface. It could sometimes cause heavy casualties but required high maintenance due to the susceptibility of black powder to dampness. Consequently, it was mainly employed in the defenses of major fortifications, in which role it used in several European wars of the eighteenth century and the American Revolution. One of the greatest limitations of early land mines was the unreliable fuses and their susceptibility to dampness. This changed with the invention of the safety fuse. Later, command initiation, the ability to detonate a charge immediately instead of waiting several minutes for a fuse to burn, became possible after electricity was developed. An electrical current sent down a wire could ignite the charge with a spark. The Russians claim first use of this technology in the Russo-Turkish War of 1828–1829, and with it the fougasse remained useful until it was superseded by the claymore in the 1960s. Victim-activated mines were also unreliable because they relied on a flintlock to ignite the explosive. The percussion cap, developed in the early 19th century, made them much more reliable, and pressure-operated mines were deployed on land and sea in the Crimean War (1853–1856). During the American Civil War, the Confederate brigadier general Gabriel J. Rains deployed thousands of "torpedoes" consisting of artillery shells with pressure caps, beginning with the Battle of Yorktown in 1862. As a captain, Rains had earlier employed explosive booby traps during the Seminole Wars in Florida in 1840. Over the course of the war, mines only caused a few hundred casualties, but they had a large effect on morale and slowed down the advance of Union troops. Many on both sides considered the use of mines barbaric, and in response, generals in the Union Army forced Confederate prisoners to remove the mines. High explosives Starting in the 19th century, more powerful explosives than gunpowder were developed, often for non-military reasons such as blasting train tunnels in the Alps and Rockies. Guncotton, up to four times more powerful than gunpowder, was invented by Christian Schonbein in 1846. It was dangerous to make until Frederick Augustus Abel developed a safe method in 1865. From the 1870s to the First World War, it was the standard explosive used by the British military. In 1847, Ascanio Sobrero invented nitroglycerine to treat angina pectoris and it turned out to be a much more powerful explosive than guncotton. It was very dangerous to use until Alfred Nobel found a way to incorporate it in a solid mixture called dynamite and developed a safe detonator. Even then, dynamite needed to be stored carefully or it could form crystals that detonated easily. Thus, the military still preferred guncotton. In 1863, the German chemical industry developed trinitrotoluene (TNT). This had the advantage that it was difficult to detonate, so it could withstand the shock of firing by artillery pieces. It was also advantageous for land mines for several reasons: it was not detonated by the shock of shells landing nearby; it was lightweight, unaffected by damp, and stable under a wide range of conditions; it could be melted to fill a container of any shape, and it was cheap to make. Thus, it became the standard explosive in mines after the First World War. Between the American Civil War and the First World War The British used mines in the Siege of Khartoum to hold off a much larger Sudanese Mahdist force for ten months. In the end, however, the town was taken and the British massacred. In the Boer War (1899–1903), they succeeded in holding Mafeking against Boer forces with the help of a mixture of real and fake minefields; and they laid mines alongside railroad tracks to discourage sabotage. In the Russo-Japanese War of 1904–1905, both sides used land and sea mines, although the effect on land mainly affected morale. The naval mines were far more effective, destroying several battleships. First World War One sign of the increasing power of explosives used in land mines was that, by the First World War, they burst into about 1,000 high-velocity fragments; in the Franco-Prussian War (1870), it had only been 20 to 30 fragments. Nevertheless, antipersonnel mines were not a big factor in the war because machine guns, barbed wire and rapid-fire artillery were far more effective defenses. An exception was in Africa (now Tanzania and Namibia) where the warfare was much more mobile. Towards the end of the war, the British started to use tanks to break through trench defenses. The Germans responded with anti-tank guns and mines. Improvised mines gave way to mass-produced mines consisting of wooden boxes filled with guncotton, and minefields were standardized to stop masses of tanks from advancing. Between world wars, the future Allies did little work on land mines, but the Germans developed a series of anti-tank mines, the Tellermines (plate mines). They also developed the Schrapnell mine (also known as the S-mine), the first bounding mine. When triggered, this jumped up to about waist height and exploded, sending thousands of steel balls in all directions. Triggered by pressure, trip wires or electronics, it could harm soldiers within an area of about 2,800 square feet. Second World War Tens of millions of mines were laid in the Second World War, particularly in the deserts of North Africa and the steppes of Eastern Europe, where the open ground favored tanks. However, the first country to use them was Finland. They were defending against a much larger Soviet force with over 6,000 tanks, twenty times the number the Finns had; but they had terrain that was broken up by lakes and forests, so tank movement was restricted to roads and tracks. Their defensive line, the Mannerheim Line, integrated these natural defenses with mines, including simple fragmentation mines mounted on stakes. While the Germans were advancing rapidly using blitzkrieg tactics, they did not make much use of mines. After 1942, however, they were on the defensive and became the most inventive and systematic users of mines. Their production shot up and they began inventing new types of mines as the Allies found ways to counter the existing ones. To make it more difficult to remove antitank mines, they surrounded them with S-mines and added anti-handling devices that would explode when soldiers tried to lift them. They also took a formal approach to laying mines and they kept detailed records of the locations of mines. In the Second Battle of El Alamein in 1942, the Germans prepared for an Allied attack by laying about half a million mines in two fields running across the entire battlefield and five miles deep. Nicknamed the "Devil's gardens", they were covered by 88 mm anti-tank guns and small-arms fire. The Allies prevailed, but at the cost of over half their tanks; 20 percent of the losses were caused by mines. The Soviets learned the value of mines from their war with Finland, and when Germany invaded, they made heavy use of them, manufacturing over 67 million. At the Battle of Kursk, which put an end to the German advance, they laid over a million mines in eight belts with an overall depth of 35 kilometres. Mines forced tanks to slow down and wait for soldiers to go ahead and remove the mines. The main method of breaching minefields involved prodding the dirt with a bayonet or stick at an angle of 30 degrees (to avoid putting pressure on the top of the mine and detonating it). Since all mines at the beginning of the war had metal casings, metal detectors could be used to speed up the locating of mines. A Polish officer, Józef Kosacki, developed a portable mine detector known as the Polish mine detector. To counter the detector, Germans developed mines with wooden casings, the Schu-mine 42 (antipersonnel) and Holzmine 42 (anti-tank). Effective, cheap and easy to make, the schu mine became the most common mine in the war. Mine casings were also made of glass, concrete and clay. The Russians developed a mine with a pressed-cardboard casing, the PMK40, and the Italians made an anti-tank mine out of bakelite. In 1944, the Germans created the Topfmine, an entirely non-metallic mine. They ensured that they could detect their own mines by covering them with radioactive sand, but the Allies did not find this out until after the war. Several mechanical methods for clearing mines were tried. Heavy rollers attached to tanks or cargo trucks, but they did not last long and their weight made the tanks considerably slower. Tanks and bulldozers pushed ploughs that in turn pushed aside any mines to a depth of 30 cm. The Bangalore torpedo, a long thin tube filled with explosives, was invented in 1912 and used to clear barbed wire. Larger versions such as the Snake and the Conger were developed but were not very effective. One of the best options was the flail, which chains with weights on the end attached to rotating drums. The first version, the Scorpion, was attached to the Matilda tank and used in the Second Battle of El Alamein. The Crab, attached to the Sherman tank, was faster (2 kilometers per hour); it was used during D-Day and the aftermath. Cold War During the Cold War, the members of NATO were concerned about massive armored attacks by the Soviet Union. They planned for a minefield stretching across the entire West German border, and developed new types of mine. The British designed an anti-tank mine, the Mark 7, to defeat rollers by detonating the second time it was pressed. It also had a 0.7-second delay so the tank would be directly over the mine. They also developed the first scatterable mine, the No. 7 ("Dingbat"). The Americans used the M6 antitank mine and tripwire-operated bounding antipersonnel mines such as the M2 and M16. In the Korean War, land mine use was dictated by the steep terrain, narrow valleys, forest cover and lack of developed roads. This made tanks less effective and more easily stopped by mines. However, mines laid near roads were often easy to spot. In response to this problem, the US developed the M24, a mine that was placed off to the side of the road. When triggered by a tripwire, it fired a rocket. However, the mine was not available until after the war. The Chinese had a lot of success with massed infantry attacks. The extensive forest cover limited the range of machine guns, but anti-personnel mines were effective. However, mines were poorly recorded and marked, often becoming as much a hazard to allies as enemies. Tripwire-operated mines were not defended by pressure mines; the Chinese were often able to disable them and reuse them against UN forces. Looking for more destructive mines, the Americans developed the Claymore, a directional fragmentation mine that hurls steel balls in a 60-degree arc at a lethal speed of 1,200 metres per second. They also developed a pressure-operated mine, the M14 ("toe-popper"). These, too, were ready too late for the Korean war. In 1948, the British developed the No. 6 antipersonnel mine, a minimum-metal mine with a narrow diameter, making it difficult to detect with metal detectors or prodding. Its three-pronged pressure piece inspired the nickname "carrot mine". However, it was unreliable in wet conditions. In the 1960s the Canadians developed a similar, but more reliable mine, the C3A1 ("Elsie") and the British army adopted it. The British also developed the L9 bar mine, a wide anti-tank mine with a rectangular shape, which covered more area, allowing a minefield to be laid four times as fast as previous mines. They also upgraded the Dingbat to the Ranger, a plastic mine that was fired from a truck-mounted discharger that could fire 72 mines at a time. In the 1950s, the US Operation Doan Brook studied the feasibility of delivering mines by air. This led to three types of air-delivered mine. Wide area anti-personnel mines (WAAPMs) were small steel spheres that discharged tripwires when they hit the ground; each dispenser held 540 mines. The BLU-43 Dragontooth was small and had a flattened W shape to slow its descent, while the gravel mine was larger. Both were packed by the thousand into bombs. All three were designed to inactivate after a period of time, but any that failed to activate presented a safety challenge. Over 37 million Gravel mines were produced between 1967 and 1968, and when they were dropped in places like Vietnam their locations were unmarked and unrecorded. A similar problem was presented by unexploded cluster munitions. The next generation of scatterable mines arose in response to the increasing mobility of war. The Germans developed the Skorpion system, which scattered AT2 mines from a tracked vehicle. The Italians developed a helicopter delivery system that could rapidly switch between SB-33 anti-personnel mines and SB-81 anti-tank mines. The US developed a range of systems called the Family of Scatterable Mines (FASCAM) that could deliver mines by fast jet, artillery, helicopter and ground launcher. Middle eastern conflicts The Iraq-Iran War, the Gulf War, and the Islamic State have all contributed to land mine saturation in Iraq from the 1980s through 2020. Iraq is now the most saturated country in the world with landmines. Countries that provided land mines during the Iran-Iraq War included Belgium, Canada, Chile, China, Egypt, France, Italy, Romania, Singapore, the former Soviet Union and the U.S., and were concentrated in the Kurdish areas in the northern area of Iraq. During the Gulf War, the U.S. deployed 117,634 mines, with 27,967 being anti-personnel mines and 89,667 being anti-vehicle mines. The U.S. did not use land mines during the Iraq War. Chemical and nuclear In the First World War, the Germans developed a device, nicknamed the "Yperite Mine" by the British, that they left behind in abandoned trenches and bunkers. It was detonated by a delayed charge, spreading mustard gas ("Yperite"). In the Second World War they developed a modern chemical mine, the Sprüh-Büchse 37 (Bounding Gas Mine 37), but never used it. The United States developed the M1 chemical mine , which used mustard gas, in 1939; and the M23 chemical mine, which used the VX nerve agent, in 1960. The Soviets developed the KhF, a "bounding chemical mine". The French had chemical mines and the Iraqis were believed to have them before the invasion of Kuwait. In 1997, the Chemical Weapons Convention came into force, prohibiting the use of chemical weapons and mandating their destruction. As of April 30, 2019, 97% of the declared stockpiles of chemical weapons were destroyed. For a few decades during the Cold War, the U.S. developed atomic demolition munitions, often referred to as nuclear land mines. These were portable nuclear bombs that could be placed by hand, and could be detonated remotely or with a timer. Some of these were deployed in Europe. Governments in West Germany, Turkey and Greece wanted to have nuclear minefields as a defense against attack from the Warsaw Pact. However, such weapons were politically and tactically infeasible, and by 1989 the last of these munitions was retired. The British also had a project, codenamed Blue Peacock, to develop nuclear mines to be buried in Germany; the project was cancelled in 1958. Characteristics and function A conventional land mine consists of a casing that is mostly filled with the main charge. It has a firing mechanism such as a pressure plate; this triggers a detonator or igniter, which in turn sets off a booster charge. There may be additional firing mechanisms in anti-handling devices. Firing mechanisms and initiating actions A land mine can be triggered by a number of things including pressure, movement, sound, magnetism and vibration. Anti-personnel mines commonly use the pressure of a person's foot as a trigger, but tripwires are also frequently employed. Most modern anti-vehicle mines use a magnetic trigger to enable it to detonate even if the tires or tracks did not touch it. Advanced mines are able to sense the difference between friendly and enemy types of vehicles by way of a built-in signature catalog. This will theoretically enable friendly forces to use the mined area while denying the enemy access. Many mines combine the main trigger with a touch or tilt trigger to prevent enemy engineers from defusing it. Land mine designs tend to use as little metal as possible to make searching with a metal detector more difficult; land mines made mostly of plastic have the added advantage of being very inexpensive. Some types of modern mines are designed to self-destruct, or chemically render themselves inert after a period of weeks or months to reduce the likelihood of civilian casualties at the conflict's end. These self-destruct mechanisms are not absolutely reliable, and most land mines laid historically are not equipped in this manner. There is a common misperception that a landmine is armed by stepping on it and only triggered by stepping off, providing tension in movies. In fact the initial pressure trigger will detonate the mine, as they are designed to kill or maim, not to make someone stand very still until it can be disarmed. Anti-handling devices Anti-handling devices detonate the mine if someone attempts to lift, shift or disarm it. The intention is to hinder deminers by discouraging any attempts to clear minefields. There is a degree of overlap between the function of a boobytrap and an anti-handling device insofar as some mines have optional fuze pockets into which standard pull or pressure-release boobytrap firing devices can be screwed. Alternatively, some mines may mimic a standard design, but actually be specifically intended to kill deminers, such as the MC-3 and PMN-3 variants of the PMN mine. Anti-handling devices can be found on both anti-personnel mines and anti-tank mines, either as an integral part of their design or as improvised add-ons. For this reason, the standard render safe procedure for mines is often to destroy them on site without attempting to lift them. Anti-tank mines Anti-tank mines were created not long after the invention of the tank in the First World War. At first improvised, purpose-built designs were developed. Set off when a tank passes, they attack the tank at one of its weaker areas – the tracks. They are designed to immobilize or destroy vehicles and their occupants. In U.S. military terminology destroying the vehicles is referred to as a catastrophic kill while only disabling its movement is referred to as a mobility kill. Anti-tank mines are typically larger than anti-personnel mines and require more pressure to detonate. The high trigger pressure, normally requiring prevents them from being set off by infantry or smaller vehicles of lesser importance. More modern anti-tank mines use shaped charges to focus and increase the armor penetration of the explosives. Anti-personnel mines Anti-personnel mines are designed primarily to kill or injure people, as opposed to vehicles. They are often designed to injure rather than kill to increase the logistical support (evacuation, medical) burden on the opposing force. Some types of anti-personnel mines can also damage the tracks or wheels of armored vehicles. In the asymmetric warfare conflicts and civil wars of the 21st century, improvised explosives, known as IEDs, have partially supplanted conventional landmines as the source of injury to dismounted (pedestrian) soldiers and civilians. IEDs are used mainly by insurgents and terrorists against regular armed forces and civilians. The injuries from the anti-personnel IED were recently reported in BMJ Open to be far worse than with landmines resulting in multiple limb amputations and lower body mutilation. Warfare Land mines were designed for two main uses: To create defensive tactical barriers, channelling attacking forces into predetermined fire zones or slowing an invading force's progress to allow reinforcements to arrive. To act as passive area-denial weapons (to deny the enemy use of valuable terrain, resources or facilities when active defense of the area is not desirable or possible). Land mines are currently used in large quantities mostly for this first purpose, thus their widespread use in the demilitarized zones (DMZs) of likely flashpoints such as Cyprus, Afghanistan and Korea. As of 2013, the only governments that still laid land mines were Myanmar in its internal conflict, and Syria in its civil war. In military science, minefields are considered a defensive or harassing weapon, used to slow the enemy down, to help deny certain terrain to the enemy, to focus enemy movement into kill zones, or to reduce morale by randomly attacking material and personnel. In some engagements during World War II, anti-tank mines accounted for half of all vehicles disabled. Since combat engineers with mine-clearing equipment can clear a path through a minefield relatively quickly, mines are usually considered effective only if covered by fire. The extents of minefields are often marked with warning signs and cloth tape, to prevent friendly troops and non-combatants from entering them. Of course, sometimes terrain can be denied using dummy minefields. Most forces carefully record the location and disposition of their own minefields, because warning signs can be destroyed or removed, and minefields should eventually be cleared. Minefields may also have marked or unmarked safe routes to allow friendly movement through them. Placing minefields without marking and recording them for later removal is considered a war crime under Protocol II of the Convention on Certain Conventional Weapons, which is itself an annex to the Geneva Conventions. Artillery and aircraft scatterable mines allow minefields to be placed in front of moving formations of enemy units, including the reinforcement of minefields or other obstacles that have been breached by enemy engineers. They can also be used to cover the retreat of forces disengaging from the enemy, or for interdiction of supporting units to isolate front line units from resupply. In most cases these minefields consist of a combination of anti-tank and anti-personnel mines, with the anti-personnel mines making removal of the anti-tank mines more difficult. Mines of this type used by the United States are designed to self-destruct after a preset period of time, reducing the requirement for mine clearing to only those mines whose self-destruct system did not function. Some designs of these scatterable mines require an electrical charge (capacitor or battery) to detonate. After a certain period of time, either the charge dissipates, leaving them effectively inert or the circuitry is designed such that upon reaching a low level, the device is triggered, thus destroying the mine. Guerrilla warfare None of the conventional tactics and norms of mine warfare applies when they are employed in a guerrilla role: The mines are not used in defensive roles (for specific position or area). Mined areas are not marked. Mines are usually placed singly and not in groups covering an area. Mines are often left unattended (not covered by fire). Land mines were commonly deployed by insurgents during the South African Border War, leading directly to the development of the first dedicated mine-protected armoured vehicles in South Africa. Namibian insurgents used anti-tank mines to throw South African military convoys into disarray before attacking them. To discourage detection and removal efforts, they also laid anti-personnel mines directly parallel to the anti-tank mines. This initially resulted in heavy South African military and police casualties, as the vast distances of road network vulnerable to insurgent sappers every day made comprehensive detection and clearance efforts impractical. The only other viable option was the adoption of mine-protected vehicles which could remain mobile on the roads with little risk to their passengers even if a mine was detonated. South Africa is widely credited with inventing the v-hull, a vee-shaped hull for armoured vehicles which deflects mine blasts away from the passenger compartment. During the ongoing Syrian Civil War, Iraqi Civil War (2014–2017) and Yemeni Civil War (2015–present) landmines have been used for both defensive and guerrilla purposes. Laying mines Minefields may be laid by several means. The preferred, but most labour-intensive, way is to have engineers bury the mines, since this will make the mines practically invisible and reduce the number of mines needed to deny the enemy an area. Mines can be laid by specialized mine-laying vehicles. Mine-scattering shells may be fired by artillery from a distance of several tens of kilometers. Mines may be dropped from helicopters or airplanes, or ejected from cluster bombs or cruise missiles. Anti-tank minefields can be scattered with anti-personnel mines to make clearing them manually more time-consuming; and anti-personnel minefields are scattered with anti-tank mines to prevent the use of armored vehicles to clear them quickly. Some anti-tank mine types are also able to be triggered by infantry, giving them a dual purpose even though their main and official intention is to work as anti-tank weapons. Some minefields are specifically booby-trapped to make clearing them more dangerous. Mixed anti-personnel and anti-tank minefields, anti-personnel mines under anti-tank mines, and fuses separated from mines have all been used for this purpose. Often, single mines are backed by a secondary device, designed to kill or maim personnel tasked with clearing the mine. Multiple anti-tank mines have been buried in stacks of two or three with the bottom mine fuzed, to multiply the penetrating power. Since the mines are buried, the ground directs the energy of the blast in a single direction—through the bottom of the target vehicle or on the track. Another specific use is to mine an aircraft runway immediately after it has been bombed to delay or discourage repair. Some cluster bombs combine these functions. One example was the British JP233 cluster bomb which includes munitions to damage (crater) the runway as well as anti-personnel mines in the same cluster bomb. As a result of the anti-personnel mine ban it was withdrawn from British Royal Air Force service, and the last stockpiles of the mine were destroyed on October 19, 1999. Demining Metal detectors were first used for demining, after their invention by the Polish officer Józef Kosacki. His invention, known as the Polish mine detector, was used by the Allies alongside mechanical methods, to clear the German mine fields during the Second Battle of El Alamein when 500 units were shipped to Field Marshal Montgomery's Eighth Army. The Nazis used captured civilians who were chased across minefields to detonate the explosives. According to Laurence Rees "Curt von Gottberg, the SS-Obergruppenführer who, during 1943, conducted another huge anti-partisan action called Operation Kottbus on the eastern border of Belarus, reported that 'approximately two to three thousand local people were blown up in the clearing of the minefields'." Whereas the placing and arming of mines is relatively inexpensive and simple, the process of detecting and removing them is typically expensive, slow, and dangerous. This is especially true of irregular warfare where mines were used on an ad hoc basis in unmarked areas. Anti-personnel mines are most difficult to find, due to their small size and the fact that many are made almost entirely of non-metallic materials specifically to escape detection. Manual clearing remains the most effective technique for clearing mine fields, although hybrid techniques involving the use of animals and robots are being developed. Animals are desirable due to their strong sense of smell, which is more than capable of detecting a land mine. Animals like rats and dogs can also differentiate between other metal objects and land mines because they can be trained to detect the explosive agent itself. Other techniques involve the use of geo-location technologies. A joint team of researchers at the University of New South Wales and Ohio State University is working to develop a system based on multi-sensor integration. The laying of land mines has inadvertently led to a positive development in the Falkland Islands. Mine fields laid near the sea during the Falklands War have become favorite places for penguins, which do not weigh enough to detonate the mines. Therefore, they can breed safely, free of human intrusion. These odd sanctuaries have proven so popular and lucrative for ecotourism that efforts exist to prevent removal of the mines. International treaties The use of land mines is controversial because they are indiscriminate weapons, harming soldier and civilian alike. They remain dangerous after the conflict in which they were deployed has ended, killing and injuring civilians and rendering land impassable and unusable for decades. To make matters worse, many factions have not kept accurate records (or any at all) of the exact locations of their minefields, making removal efforts painstakingly slow. These facts pose serious difficulties in many developing nations where the presence of mines hampers resettlement, agriculture, and tourism. The International Campaign to Ban Landmines campaigned successfully to prohibit their use, culminating in the 1997 Convention on the Prohibition of the Use, Stockpiling, Production and Transfer of Anti-Personnel Mines and on their Destruction, known informally as the Ottawa Treaty. The Treaty came into force on March 1, 1999. The treaty was the result of the leadership of the Governments of Canada, Norway, South Africa and Mozambique working with the International Campaign to Ban Landmines, launched in 1992. The campaign and its leader, Jody Williams, won the Nobel Peace Prize in 1997 for its efforts. The treaty does not include anti-tank mines, cluster bombs or claymore-type mines operated in command mode and focuses specifically on anti-personnel mines, because these pose the greatest long term (post-conflict) risk to humans and animals since they are typically designed to be triggered by any movement or pressure of only a few kilograms, whereas anti-tank mines require much more weight (or a combination of factors that would exclude humans). Existing stocks must be destroyed within four years of signing the treaty. Signatories of the Ottawa Treaty agree that they will not use, produce, stockpile or trade in anti-personnel land mines. In 1997, there were 122 signatories; as of early 2016, 162 countries have joined the Treaty. Thirty-six countries, including the People's Republic of China, the Russian Federation and the United States, which together may hold tens of millions of stockpiled antipersonnel mines, are not party to the Convention. Another 34 have yet to sign on. The United States did not sign because the treaty lacks an exception for the Korean Demilitarized Zone. There is a clause in the treaty, Article 3, which permits countries to retain land mines for use in training or development of countermeasures. Sixty-four countries have taken this option. As an alternative to an outright ban, 10 countries follow regulations that are contained in a 1996 amendment of Protocol II of the Convention on Conventional Weapons (CCW). The countries are China, Finland, India, Israel, Morocco, Pakistan, South Korea and the United States. Sri Lanka, which had adhered to this regulation, announced in 2016 that it would join the Ottawa Treaty. Submunitions and unexploded ordinance from cluster munitions can also function as landmines, in that they continue to kill and maim indiscriminately long after conflicts have ended. The Convention on Cluster Munitions (CCM) is an international treaty that prohibits the use, distribution, or manufacture of cluster munitions. The CCM entered into force in 2010, and has been ratified by over 100 countries. Manufacturers Before the Ottawa Treaty was adopted, the Arms Project of Human Rights Watch identified "almost 100 companies and government agencies in 48 countries" that had manufactured "more than 340 types of antipersonnel landmines in recent decades." Five to ten million mines were produced per year with a value of $50 to $200 million. The largest producers were probably China, Italy and the Soviet Union. The companies involved included giants such as Daimler-Benz, the Fiat Group, the Daewoo Group, RCA and General Electric. As of 2017, the Landmine & Cluster Munition Monitor identified four countries that were "likely to be actively producing" land mines: India, Myanmar, Pakistan and South Korea. Another seven states reserved the right to make them but were probably not doing so: China, Cuba, Iran, North Korea, Russia, Singapore, and Vietnam. Impacts Throughout the world there are millions of hectares that are contaminated with land mines. Casualties From 1999 to 2017, the Landmine Monitor has recorded over 120,000 casualties from mines, IEDs and explosive remnants of war; it estimates that another 1,000 per year go unrecorded. The estimate for all time is over half a million. In 2017, at least 2,793 were killed and 4,431 injured. 87% of the casualties were civilians and 47% were children (less than 18 years old). The largest numbers of casualties were in Afghanistan (2,300), Syria (1,906), and Ukraine (429). Environmental Natural disasters can have a significant impact on efforts to demine areas of land. For example, the floods that occurred in Mozambique in 1999 and 2000 may have displaced hundreds of thousands of land mines left from the war. Uncertainty about their locations delayed recovery efforts. Land degradation From a study by Asmeret Asefaw Berhe, land degradation caused by land mines "can be classified into five groups: access denial, loss of biodiversity, micro-relief disruption, chemical composition, and loss of productivity". The effects of an explosion depend on: "(i) the objectives and methodological approaches of the investigation; (ii) concentration of mines in a unit area; (iii) chemical composition and toxicity of the mines; (iv) previous uses of the land and (v) alternatives that are available for the affected populations." Access denial The most prominent ecological issue associated with landmines (or fear of them) is denial of access to vital resources (where "access" refers to the ability to use resources, in contrast to "property", the right to use them). The presence and fear of presence of even a single landmine can discourage access for agriculture, water supplies and possibly conservation measures. Reconstruction and development of important structures such as schools and hospitals are likely to be delayed, and populations may shift to urban areas, increasing overcrowding and the risk of spreading diseases. Access denial can have positive effects on the environment. When a mined area becomes a "no-man's land", plants and vegetation have a chance to grow and recover. For example, formerly arable lands in Nicaragua returned to forests and remained undisturbed after the establishment of landmines. Similarly, the Penguins of the Falkland Islands have benefited because they are not heavy enough to trigger the mines present. However, these benefits can only last as long as animals, tree limbs, etc. do not detonate the mines. In addition, long idle periods could "potentially end up creating or exacerbating loss of productivity", particularly within land of low quality. Loss of biodiversity Landmines can threaten biodiversity by wiping out vegetation and wildlife during explosions or demining. This extra burden can push threatened and endangered species to extinction. They have also been used by poachers to target endangered species. Displace people refugees hunt animals for food and destroy habitat by making shelters. Shrapnel, or abrasions of bark or roots caused by detonated mines, can cause the slow death of trees and provide entry sites for wood-rotting fungi. When landmines make land unavailable for farming, residents resort to the forests to meet all of their survival needs. This exploitation furthers the loss of biodiversity. Chemical contamination Near mines that have exploded or decayed, soils tend to be contaminated, particularly with heavy metals. Products produced from the explosives, both organic and inorganic substances, are most likely to be "long lasting, water-soluble and toxic even in small amounts". They can be implemented either "directly or indirectly into soil, water bodies, microorganisms and plants with drinking water, food products or during respiration". Toxic compounds can also find their way into bodies of water and accumulate in land animals, fish and plants. They can act "as a nerve poison to hamper growth", with deadly effect. See also Countermine System Demolition belt Mine Protected Vehicle Unexploded ordnance (UXO) Improvised explosive device Convention on Cluster Munitions TM 31-210 Improvised Munitions Handbook Mines ARGES mine Blast resistant mine Intelligent Munitions System List of land mines Minimum metal mine PFM-1 Smart mine Wooden box mine Bulgarian anti-helicopter mines Places Land mines in Central America Land mines in Cambodia Landmines in Israel Land mines in North Africa Uzbek-Tajikistan border minefields Organisations Mines Advisory Group (MAG) Mine clearance agencies Notes References External links ICBL: International Campaign to Ban Landmines Landmines and international humanitarian law, ICRC Detector Spots Buried Mines 1943, Popular Science article on the "Polish" mine detector. "How Axis Land Mines Work", April 1944 detailed article on types of land mines E-Mine Electronic Mine Information Network by United Nations Mine Action Services Detecting Land Mines: New Technology, by Paul Grad. Published by Asian Surveying and Mapping Ken Rutherford, "Landmines: A Survivor’s Tale" – Journal of Mine Action Chinese inventions Explosive weapons	[ 0.2776740491390228, 0.5295524597167969, -0.44722285866737366, -0.24128128588199615, 0.3649623692035675, -0.08895380049943924, 0.4681319296360016, -0.3525333106517792, -0.001458028331398964, -0.39201340079307556, -0.9775756001472473, 0.7001826167106628, 0.1362863928079605, 0.231359943747520...
18173	https://en.wikipedia.org/wiki/List%20of%20libertarian%20political%20parties	List of libertarian political parties	Many countries and subnational political entities have libertarian parties. Although these parties may describe themselves as libertarian, they follow classical liberalism and their ideologies differ considerably, and not all of them support all elements of libertarianism. Most of these political parties are right-libertarians, or are right-leaning for favouring classical liberalism and economic liberalism, as left-libertarians take a different approach, generally opposing electoral politics and political parties themselves; exceptions have been the Libertarian Left in Chile, Libertarian Peru (now Free Peru), and the Radical Party in Italy. Active parties by country Defunct parties by country Organizations associated with Libertarian parties See also Liberal parties by country List of libertarian organizations Lists of political parties Outline of libertarianism References Libertarian	[ 0.21678930521011353, -0.06265180557966232, -0.08011671900749207, 0.4293787181377411, -0.7291294932365417, -0.270601361989975, 0.17739950120449066, 0.8592866659164429, -0.6539358496665955, 0.16527114808559418, -0.2995816171169281, 0.042646437883377075, -0.4194626212120056, -0.07045879215002...
18175	https://en.wikipedia.org/wiki/Lwa	Lwa	( ), also called loa or loi, are spirits in the African diasporic religion of Haitian Vodou. They have also been incorporated into some revivalist forms of Louisiana Voodoo. Many of the lwa derive their identities in part from deities venerated in the traditional religions of West Africa, especially those of the Fon and Yoruba. In Haitian Vodou, the lwa serve as intermediaries between humanity and Bondyé, a transcendent creator divinity. Vodouists believe that over a thousand lwa exist, the names of at least 232 of which are recorded. Each lwa has its own personality and is associated with specific colors and objects. Many of them are equated with specific Roman Catholic saints on the basis of similar characteristics or shared symbols. The lwa are divided into different groups, known as nanchon (nations), the most notable of which are the Petwo and the Rada. According to Vodou belief, the lwa communicate with humans through dreams and divination, and in turn are given offerings, including sacrificed animals. Vodou teaches that during ceremonies, the lwa possess specific practitioners, who during the possession are considered the chwal (horse) of the lwa. Through possessing an individual, Vodouists believe, the lwa can communicate with other humans, offering advice, admonishment, or healing. During the Atlantic slave trade of the 16th to 19th centuries, thousands of enslaved West Africans were transported to the Americas, often bringing their traditional religions with them. In the French colony of Saint-Domingue, which became the republic of Haiti in the early 19th century, the diasporic religion of Vodou emerged amid the mixing of different West African traditional religions and the influence of the French colonists' Roman Catholicism. From at least the 19th century, Haitian migrants took their religion to Louisiana, by that point part of the United States, where they contributed to the formation of Louisiana Voodoo, a religion that largely died out in the early 20th century. In the latter part of that century, Voodoo revivalist groups emerged in Louisiana, often incorporating both the lwa spirits of Haitian Vodou and the oricha spirits of Cuban Santería into their practices. Etymology Modern linguists trace the etymology of lwa to a family of Yoruba language words which include (god) and babalawo (diviner or priest). The term lwa is phonetically identical to both a French term for law, loi, and a Haitian Creole term for law, lwa. The early 20th-century writer Jean Price-Mars pondered if the term lwa, used in reference to Vodou spirits, emerged from their popular identification with the laws of the Roman Catholic Church. In the early 21st century, the historian Kate Ramsey agreed that the phonetic similarity between the terms for the law and the Vodou spirits may not be "mere linguistic coincidence" but could reflect the complex interactions of African and French colonial cultures in Haiti. Several spelling for lwa have been used. Early 20th-century writers on Haitian religion, such as Price-Mars, usually spelled the term loi. During that century, writers like the American anthropologist Melville Herskovits favored the spelling loa, although in 2008 the historian Jeffrey E. Anderson wrote that the spelling loa was typically found in older works on the topic, having fallen out of favor with scholarly writers. The spelling lwa has been favored by more recent scholarly writers including Anderson, Ramsey, the anthropologist Karen McCarthy Brown, the scholar of religious studies Leslie Desmangles, and the Hispanic studies scholars Margarite Fernández Olmos and Lizabeth Paravisini-Gebert. Theology Vodou teaches that there are over a thousand lwa. They are regarded as the intermediaries of Bondyé, the supreme creator deity in Vodou. Desmangles argued that by learning about the various lwas, practitioners come to understand the different facets of Bondyé. Much as Vodouists often identify Bondyé with the Christian God, the lwa are sometimes equated with the angels of Christian cosmology. The lwa are also known as the mystères, anges, saints, and les invisibles. The lwa can offer help, protection, and counsel to humans, in return for ritual service. They are thought of as having wisdom that is useful for humans, although they are not seen as moral exemplars which practitioners should imitate. Each lwa has its own personality, and is associated with specific colors, days of the week, and objects. The lwa can be either loyal or capricious in their dealings with their devotees; Vodouists believe that the lwa are easily offended, for instance if offered food that they dislike. When angered, the lwa are believed to remove their protection from their devotees, or to inflict misfortune, illness, or madness on an individual. Although there are exceptions, most lwa names derive from the Fon and Yoruba languages. New lwa are nevertheless added to those brought from Africa; practitioners believe that some Vodou priests and priestesses became lwa after death, or that certain talismans become lwa. Vodouists often refer to the lwa residing in "Guinea", but this is not intended as a precise geographical location. Many lwa are also understood to live under the water, at the bottom of the sea or in rivers. Vodouists believe that the lwa communicate with humans through dreams and through the possession of human beings. During rituals, the lwa are summoned through designs known as veve. These are sketched out on the floor of the ceremonial space using cornmeal, ash, coffee grounds, or powdered eggshells. The lwa are associated with specific Roman Catholic saints. For instance, Azaka, the lwa of agriculture, is associated with Saint Isidore the farmer. Similarly, because he is understood as the "key" to the spirit world, Papa Legba is typically associated with Saint Peter, who is visually depicted holding keys in traditional Roman Catholic imagery. The lwa of love and luxury, Ezili Freda, is associated with Mater Dolorosa. Damballa, who is a serpent, is often equated with Saint Patrick, who is traditionally depicted in a scene with snakes; alternatively he is often associated with Moses. The Marasa, or sacred twins, are typically equated with the twin saints Cosmos and Damian. Nanchon In Haitian Vodou, the lwa are divided into nanchon or "nations". This classificatory system derives from the way in which enslaved West Africans were divided into "nations" upon their arrival in Haiti, usually based on their African port of departure rather than their ethno-cultural identity. The nanchons are nevertheless not groupings based in the geographical origins of specific lwas. The term fanmi (family) is sometimes used synonymously with "nation" or alternatively as a sub-division of the latter category. It is often claimed that there are 17 nanchon, although few Haitians could name all of them. Each is deemed to have its own characteristic ethos. Among the more commonly known nanchon are the Wangol, Ginen, Kongo, Nago (or Anago), Ibo, Rada, and Petwo. Of these, the Rada and the Petwo are the largest and most dominant. The Rada derive their name from Arada, a city in the Dahomey kingdom of West Africa. The Rada lwa are usually regarded as dous or doux, meaning that they are sweet-tempered. The Petwo lwa are conversely seen as lwa chaud (lwa cho), indicating that they can be forceful or violent and are associated with fire; they are generally regarded as being socially transgressive and subversive. The Rada lwa are seen as being 'cool'; the Petwo lwa as 'hot'. The Rada lwa are generally regarded as righteous, whereas their Petwo counterparts are thought of as being more morally ambiguous, associated with issues like money. At the same time, the Rada lwa are regarded as being less effective or powerful than those of the Petwo nation. The Petwo lwa derive from various backgrounds, including Creole, Kongo, and Dahomeyan. In various cases, certain lwa can be absorbed from one nanchon into another; various Kongo and Ibo lwa have been incorporated into the Petwo nanchon. Many lwa exist andezo or en deux eaux, meaning that they are "in two waters" and are served in both Rada and Petwo rituals. Various lwas are understood to have direct counterparts in different nanchon; several Rada lwas for instance have Petwo counterparts whose names bear epithets like Flangbo (afire), Je-Rouge (Red-Eye), or Zarenyen (spider). One example is the Rada lwa Ezili, who is associated with love, but who has a Petwo parallel known as Ezili Je-Rouge, who is regarded as dangerous and prone to causing harm. Another is the Rada lwa Legba, who directs human destiny, and who is paralleled in the Petwo pantheon by Kafou Legba, a trickster who causes accidents that alter a person's destiny. The Guédé (also Ghede or Gede) family of lwa are associated with the realm of the dead. The head of the family is Baron Samedi ("Baron Saturday"). His consort is Grand Brigitte; she has authority over cemeteries and is regarded as the mother of many of the other Guédé. When the Guédé are believed to have arrived at a Vodou ceremony they are usually greeted with joy because they bring merriment. Those possessed by the Guédé at these ceremonies are known for making sexual innuendos; the Guédé's symbol is an erect penis, while the banda dance associated with them involves sexual-style thrusting. Ritual Offerings and animal sacrifice Feeding the lwa is of great importance in Vodou, with rites often termed mangers-lwa ("feeding the lwa"). Offering food and drink to the lwa is the most common ritual within the religion, conducted both communally and in the home. An oungan (priest) or manbo (priestess) will also organize an annual feast for their congregation in which animal sacrifices to various lwa will be made. The choice of food and drink offered varies depending on the lwa in question, with different lwa believed to favour different foodstuffs. Damballa for instance requires white foods, especially eggs. Foods offered to Legba, whether meat, tubers, or vegetables, need to be grilled on a fire. The lwa of the Ogu and Nago nations prefer raw rum or clairin as an offering. A mange sèc (dry meal) is an offering of grains, fruit, and vegetables that often precedes a simple ceremony; it takes its name from the absence of blood. Species used for sacrifice include chickens, goats, and bulls, with pigs often favored for petwo lwa. The animal may be washed, dressed in the color of the specific lwa, and marked with food or water. Often, the animal's throat will be cut and the blood collected in a calabash. Chickens are often killed by the pulling off of their heads; their limbs may be broken beforehand. The organs are removed and placed on the altar or vèvè. The flesh will be cooked and placed on the altar, subsequently often being buried. Maya Deren wrote that: "The intent and emphasis of sacrifice is not upon the death of the animal, it is upon the transfusion of its life to the lwa; for the understanding is that flesh and blood are of the essence of life and vigor, and these will restore the divine energy of the god." Because Agwé is believed to reside in the sea, rituals devoted to him often take place beside a large body of water such as a lake, river, or sea. His devotees sometimes sail out to Trois Ilets, drumming and singing, where they throw a white sheep overboard as a sacrifice to him. The food is typically offered when it is cool; it remains there for a while before humans can then eat it. The food is often placed within a kwi, a calabash shell bowl. Once selected, the food is placed on special calabashes known as assiettes de Guinée which are located on the altar. Offerings not consumed by the celebrants are then often buried or left at a crossroads. Libations might be poured into the ground. Vodouists believe that the lwa then consume the essence of the food. Certain foods are also offered in the belief that they are intrinsically virtuous, such as grilled maize, peanuts, and cassava. These are sometimes sprinkled over animals that are about to be sacrificed or piled upon the vèvè designs on the floor of the peristil. Possession Possession by the lwa constitutes an important element of Vodou. It lies the heart of many of its rituals; these typically take place in a temple called an ounfò, specifically in a room termed the peristil or peristyle. The person being possessed is referred to as the chwal or chual (horse); the act of possession is called "mounting a horse". Vodou teaches that a lwa can possess an individual regardless of gender; both male and female lwa can possess either men or women. Although children are often present at these ceremonies, they are rarely possessed as it is considered too dangerous. While the specific drums and songs used are designed to encourage a specific lwa to possess someone, sometimes an unexpected lwa appears and takes possession instead. In some instances a succession of lwa possess the same individual, one after the other. The trance of possession is known as the crise de lwa. Vodouists believe that during this process, the lwa enters the head of the chwal and displaces their gwo bon anj, which is one of the two halves of a person's soul. This displacement is believed to cause the chwal to tremble and convulse; Maya Deren described a look of "anguish, ordeal and blind terror" on the faces of those as they became possessed. Because their consciousness has been removed from their head during the possession, Vodouists believe that the chwal will have no memory of what occurs during the incident. The length of the possession varies, often lasting a few hours but sometimes several days. It may end with the chwal collapsing in a semi-conscious state; they are typically left physically exhausted. Some individuals attending the dance will put a certain item, often wax, in their hair or headgear to prevent possession. Once the lwa possesses an individual, the congregation greet it with a burst of song and dance. The chwal will typically bow before the officiating priest or priestess and prostrate before the poto mitan, a central pillar within the temple. The chwal is often escorted into an adjacent room where they are dressed in clothing associated with the possessing lwa. Alternatively, the clothes are brought out and they are dressed in the peristil itself. Once the chwal has been dressed, congregants kiss the floor before them. These costumes and props help the chwal take on the appearance of the lwa. Many ounfo have a large wooden phallus on hand which is used by those possessed by Ghede lwa during their dances. The chwal takes on the behaviour and expressions of the possessing lwa; their performance can be very theatrical. Those believing themselves possessed by the serpent Damballa, for instance, often slither on the floor, dart out their tongue, and climb the posts of the peristil. Those possessed by Zaka, lwa of agriculture, will dress as a peasant in a straw hat with a clay pipe and will often speak in a rustic accent. The chwal will often then join in with the dances, dancing with anyone whom they wish to, or sometimes eating and drinking. Sometimes the lwa, through the chwal, will engage in financial transactions with members of the congregation, for instance by selling them food that has been given as an offering or lending them money. Possession facilitates direct communication between the lwa and its followers; through the chwal, the lwa communicates with their devotees, offering counsel, chastisement, blessings, warnings about the future, and healing. Lwa possession has a healing function, with the possessed individual expected to reveal possible cures to the ailments of those assembled. Clothing that the chwal touches is regarded as bringing luck. The lwa may also offer advice to the individual they are possessing; because the latter is not believed to retain any memory of the events, it is expected that other members of the congregation will pass along the lwa's message. In some instances, practitioners have reported being possessed at other times of ordinary life, such as when someone is in the middle of the market, or when they are asleep. History During the closing decades of the 20th century, attempts were made to revive Louisiana Voodoo, often by individuals drawing heavily on Haitian Vodou and Cuban Santería in doing so. Among those drawing on both Vodou lwa and Santería oricha to create a new Voodoo was the African American Miriam Chamani, who established the Voodoo Spiritual Temple in the French Quarter of New Orleans in 1990. Another initiate of Haitian Vodou, the Ukrainian-Jewish American Sallie Ann Glassman, launched an alternative group, La Source Ancienne, in the city's Bywater neighborhood. A further Haitian Vodou initiate, the Louisiana Creole Ava Kay Jones, also began promoting a form of Louisiana Voodoo. List Vodouisants will sometimes comment that there are over a thousand lwas, most of whom are not known to humans. Of these, the names of at least 232 have been recorded. The large number of lwas found in Vodou contrasts with the Cuban religion of Santería, where only 15 orichas (spirits) have gained prominence among its followers. Adjassou-Linguetor Adjinakou Adya Houn'tò Agaou Agassou Agwé Anaisa Pye Anmino Ayida-Weddo Ayizan Azaka-Tonnerre Bacalou Badessy Baron Samedi Baron Criminel Belie Belcan Boli Shah Bossou Ashadeh Boum'ba Maza Brize Bugid Y Aiba Captain Debas Captain Zombi Clermeil Congo Damballa Dan Petro Dan Wédo Demeplait Dereyale Diable Tonnere Diejuste Dinclinsin Erzulie Filomez Guede Guede-Double Guede L'Orage Guede-Linto Guede Nibo Grand Bois Jean Zombi Joseph Danger Joumalonge Kalfu (Maître Carrefour, Mait' Carrefour, Mèt Kalfou, Kafou) Klemezin Klemay Lemba L'inglesou La Sirène Limba Loco Lovana Mademoiselle Charlotte Maîtresse Délai Maîtresse Hounon'gon Maman Brigitte Marassa Marinette Maroule Mombu Manze Marie Mounanchou Nago Shango Ogoun Papa Legba Pie Silibo Simbi Sobo Sousson-Pannan Senegal Ti Kita Ti Jean Quinto Ti Malice Ti Jean Petro Trois Carrefours (Kalfou Twa) Wawe See also Haitian mythology Kami Tuatha Dé Danann References Notes Citations Sources Further reading Primary sources External links Descriptions of Various Loa of Voodoo, Spring 1990, by Jan Chatland (Webster.edu) Caribbean mythology Haitian Vodou Caribbean legendary creatures	[ 0.4762665331363678, -0.24198204278945923, -0.601242184638977, -0.468458354473114, -0.007986759766936302, 0.8486884236335754, 0.2045428305864334, 0.11509726196527481, -0.46556559205055237, -0.2759355306625366, -0.33761611580848694, 0.5083930492401123, -0.12129129469394684, 0.260969072580337...
18178	https://en.wikipedia.org/wiki/Labour%20economics	Labour economics	Labour economics seeks to understand the functioning and dynamics of the markets for wage labour. Labour is a commodity that is supplied by labourers in exchange for a wage paid by demanding firms. Because these labourers exist as parts of a social, institutional, or political system, labour economics is often regarded as a sociology or political science. Labour markets or job markets function through the interaction of workers and employers. Labour economics looks at the suppliers of labour services (workers) and the demanders of labour services (employers), and attempts to understand the resulting pattern of wages, employment, and income. These patterns exist because each individual in the market is presumed to make rational choices based on the information that they know regarding wage, desire to provide labour, and desire for leisure. Labour markets are normally geographically bounded, but the rise of the internet has brought about a 'planetary labour market' in some sectors. Labour is a measure of the work done by human beings. It is conventionally contrasted with other factors of production, such as land and capital. Some theories focus on human capital, or entrepreneurship, (which refers to the skills that workers possess and not necessarily the actual work that they produce). Labour is unique to study because it is a special type of good that cannot be separated from the owner (i.e. the work cannot be separated from the person who does it). A labour market is also different from other markets in that workers are the suppliers and firms are the demanders. Macro and micro analysis of labour markets There are two sides to labour economics. Labour economics can generally be seen as the application of microeconomic or macroeconomic techniques to the labour market. Microeconomic techniques study the role of individuals and individual firms in the labour market. Macroeconomic techniques look at the interrelations between the labour market, the goods market, the money market, and the foreign trade market. It looks at how these interactions influence macro variables such as employment levels, participation rates, aggregate income and gross domestic product. Macroeconomics of labour markets The labour market in macroeconomic theory shows that the supply of labour exceeds demand, which has been proven by salary growth that lags productivity growth. When labour supply exceeds demand, salary faces downward pressure due to an employer's ability to pick from a labour pool that exceeds the jobs pool. However, if the demand for labour is larger than the supply, salary increases, as employee have more bargaining power while employers have to compete for scarce labour. The Labour force (LF) is defined as the number of people of working age, who are either employed or actively looking for work (unemployed). The labour force participation rate (LFPR) is the number of people in the labour force divided by the size of the adult civilian noninstitutional population (or by the population of working age that is not institutionalized), LFPR = LF/Population. The non-labour force includes those who are not looking for work, those who are institutionalized (such as in prisons or psychiatric wards), stay-at-home spouses, children not of working age, and those serving in the military. The unemployment level is defined as the labour force minus the number of people currently employed. The unemployment rate is defined as the level of unemployment divided by the labour force. The employment rate is defined as the number of people currently employed divided by the adult population (or by the population of working age). In these statistics, self-employed people are counted as employed. The skills required in a labour force can vary from individual to individual, as well as from firm to firm. Some firms have specific skills they are interested in, limiting the labour force to certain criteria. A firm requiring specific skills will help determine the size of the market. Variables like employment level, unemployment level, labour force, and unfilled vacancies are called stock variables because they measure a quantity at a point in time. They can be contrasted with flow variables which measure a quantity over a duration of time. Changes in the labour force are due to flow variables such as natural population growth, net immigration, new entrants, and retirements. Changes in unemployment depend on inflows (non-employed people starting to look for jobs and employed people who lose their jobs that are looking for new ones) and outflows (people who find new employment and people who stop looking for employment). When looking at the overall macroeconomy, several types of unemployment have been identified, which can be separated into two categories of natural and unnatural unemployment. Natural Unemployment Frictional unemployment – This reflects the fact that it takes time for people to find and settle into new jobs that they feel are appropriate for them and their skill set. Technological advancement often reduces frictional unemployment; for example, internet search engines have reduced the cost and time associated with locating employment or personnel selection. Structural unemployment – the number of jobs available in an industry are not sufficient enough to provide jobs to all persons who are interested in working or qualified to work in that industry. This can be due to the changes in industries prevalent in a country or because wages for the industry are too high, causing people to want to supply their labour to that industry. Natural rate of unemployment (also known as full employment) – This is the summation of frictional and structural unemployment, that excludes cyclical contributions of unemployment (e.g. recessions) and seasonal unemployment. It is the lowest rate of unemployment that a stable economy can expect to achieve, given that some frictional and structural unemployment is inevitable. Economists do not agree on the level of the natural rate, with estimates ranging from 1% to 5%, or on its meaning – some associate it with "non-accelerating inflation". The estimated rate varies between countries and across time. Unnatural Unemployment Demand deficient unemployment (also known as cyclical unemployment) – In Keynesian economics, any level of unemployment beyond the natural rate is probably due to insufficient goods demand in the overall economy. During a recession, aggregate expenditure is deficient causing the underutilisation of inputs (including labour). Aggregate expenditure (AE) can be increased, according to Keynes, by increasing consumption spending (C), increasing investment spending (I), increasing government spending (G), or increasing the net of exports minus imports (X−M), since AE = C + I + G + (X−M). Seasonal unemployment -- unemployment due to seasonal fluctuations of demand for workers across industries, such as in the retail industry after holidays that involve a lot of shopping are over. Neoclassical microeconomics of labour markets Neoclassical economists view the labour market as similar to other markets in that the forces of supply and demand jointly determine the price (in this case the wage rate) and quantity (in this case the number of people employed). However, the labour market differs from other markets (like the markets for goods or the financial market) in several ways. In particular, the labour market may act as a non-clearing market. While according to neoclassical theory most markets quickly attain a point of equilibrium without excess supply or demand, this may not be true of the labour market: it may have a persistent level of unemployment. Contrasting the labour market to other markets also reveals persistent compensating differentials among similar workers. Models that assume perfect competition in the labour market, as discussed below, conclude that workers earn their marginal product of labour. Neoclassical microeconomic model – Supply Households are suppliers of labour. In microeconomic theory, people are assumed to be rational and seeking to maximize their utility function. In the labour market model, their utility function expresses trade-offs in preference between leisure time and income from time used for labour. However, they are constrained by the hours available to them. Let w denote the hourly wage, k denote total hours available for labour and leisure, L denote the chosen number of working hours, π denote income from non-labour sources, and A denote leisure hours chosen. The individual's problem is to maximise utility U, which depends on total income available for spending on consumption and also depends on the time spent in leisure, subject to a time constraint, with respect to the choices of labour time and leisure time: This is shown in the graph below, which illustrates the trade-off between allocating time to leisure activities and allocating it to income-generating activities. The linear constraint indicates that every additional hour of leisure undertaken requires the loss of an hour of labour and thus of the fixed amount of goods that that labour's income could purchase. Individuals must choose how much time to allocate to leisure activities and how much to working. This allocation decision is informed by the indifference curve labelled IC1. The curve indicates the combinations of leisure and work that will give the individual a specific level of utility. The point where the highest indifference curve is just tangent to the constraint line (point A), illustrates the optimum for this supplier of labour services. If consumption is measured by the value of income obtained, this diagram can be used to show a variety of interesting effects. This is because the absolute value of the slope of the budget constraint is the wage rate. The point of optimisation (point A) reflects the equivalency between the wage rate and the marginal rate of substitution of leisure for income (the absolute value of the slope of the indifference curve). Because the marginal rate of substitution of leisure for income is also the ratio of the marginal utility of leisure (MUL) to the marginal utility of income (MUY), one can conclude: where Y is total income and the right side is the wage rate. Effects of a wage increase If the wage rate increases, this individual's constraint line pivots up from X,Y1 to X,Y2. He/she can now purchase more goods and services. His/her utility will increase from point A on IC1 to point B on IC2. To understand what effect this might have on the decision of how many hours to work, one must look at the income effect and substitution effect. The wage increase shown in the previous diagram can be decomposed into two separate effects. The pure income effect is shown as the movement from point A to point C in the next diagram. Consumption increases from YA to YC and – since the diagram assumes that leisure is a normal good – leisure time increases from XA to XC. (Employment time decreases by the same amount as leisure increases.) The Income and Substitution effects of a wage increase But that is only part of the picture. As the wage rate rises, the worker will substitute away from leisure and into the provision of labour—that is, will work more hours to take advantage of the higher wage rate, or in other words substitute away from leisure because of its higher opportunity cost. This substitution effect is represented by the shift from point C to point B. The net impact of these two effects is shown by the shift from point A to point B. The relative magnitude of the two effects depends on the circumstances. In some cases, such as the one shown, the substitution effect is greater than the income effect (in which case more time will be allocated to working), but in other cases, the income effect will be greater than the substitution effect (in which case less time is allocated to working). The intuition behind this latter case is that the individual decides that the higher earnings on the previous amount of labour can be "spent" by purchasing more leisure. The Labour Supply curve If the substitution effect is greater than the income effect, an individual's supply of labour services will increase as the wage rate rises, which is represented by a positive slope in the labour supply curve (as at point E in the adjacent diagram, which exhibits a positive wage elasticity). This positive relationship is increasing until point F, beyond which the income effect dominates the substitution effect and the individual starts to reduce the number of labour hours he supplies (point G) as wage increases; in other words, the wage elasticity is now negative. The direction of the slope may change more than once for some individuals, and the labour supply curve is different for different individuals. Other variables that affect the labour supply decision, and can be readily incorporated into the model, include taxation, welfare, work environment, and income as a signal of ability or social contribution. Neoclassical microeconomic model – Demand A firm's labour demand is based on its marginal physical product of labour (MPPL). This is defined as the additional output (or physical product) that results from an increase of one unit of labour (or from an infinitesimal increase in labour). (See also Production theory basics.) Labour demand is a derived demand; that is, hiring labour is not desired for its own sake but rather because it aids in producing output, which contributes to an employer's revenue and hence profits. The demand for an additional amount of labour depends on the Marginal Revenue Product (MRP) and the marginal cost (MC) of the worker. With a perfectly competitive goods market, the MRP is calculated by multiplying the price of the end product or service by the Marginal Physical Product of the worker. If the MRP is greater than a firm's Marginal Cost, then the firm will employ the worker since doing so will increase profit. The firm only employs however up to the point where MRP=MC, and not beyond, in neoclassical economic theory. The MRP of the worker is affected by other inputs to production with which the worker can work (e.g. machinery), often aggregated under the term "capital". It is typical in economic models for greater availability of capital for a firm to increase the MRP of the worker, all else equal. Education and training are counted as "human capital". Since the amount of physical capital affects MRP, and since financial capital flows can affect the amount of physical capital available, MRP and thus wages can be affected by financial capital flows within and between countries, and the degree of capital mobility within and between countries. According to neoclassical theory, over the relevant range of outputs, the marginal physical product of labour is declining (law of diminishing returns). That is, as more and more units of labour are employed, their additional output begins to decline. Additionally, although the MRP is a good way of expressing an employer's demand, other factors such as social group formation can the demand, as well as the labour supply. This constantly restructures exactly what a labour market is, and leads way to cause problems for theories of inflation. Neoclassical microeconomic model – Equilibrium A firm's labour demand in the short run (D) and a horizontal supply curve (S) The marginal revenue product of labour can be used as the demand for labour curve for this firm in the short run. In competitive markets, a firm faces a perfectly elastic supply of labour which corresponds with the wage rate and the marginal resource cost of labour (W = SL = MFCL). In imperfect markets, the diagram would have to be adjusted because MFCL would then be equal to the wage rate divided by marginal costs. Because optimum resource allocation requires that marginal factor costs equal marginal revenue product, this firm would demand L units of labour as shown in the diagram. The demand for labour of this firm can be summed with the demand for labour of all other firms in the economy to obtain the aggregate demand for labour. Likewise, the supply curves of all the individual workers (mentioned above) can be summed to obtain the aggregate supply of labour. These supply and demand curves can be analysed in the same way as any other industry demand and supply curves to determine equilibrium wage and employment levels. Wage differences exist, particularly in mixed and fully/partly flexible labour markets. For example, the wages of a doctor and a port cleaner, both employed by the NHS, differ greatly. There are various factors concerning this phenomenon. This includes the MRP of the worker. A doctor's MRP is far greater than that of the port cleaner. In addition, the barriers to becoming a doctor are far greater than that of becoming a port cleaner. To become a doctor takes a lot of education and training which is costly, and only those who excel in academia can succeed in becoming doctors. The port cleaner, however, requires relatively less training. The supply of doctors is therefore significantly less elastic than that of port cleaners. Demand is also inelastic as there is a high demand for doctors and medical care is a necessity, so the NHS will pay higher wage rates to attract the profession. Monopsony Some labour markets have a single employer and thus do not satisfy the perfect competition assumption of the neoclassical model above. The model of a monopsonistic labour market gives a lower quantity of employment and a lower equilibrium wage rate than does the competitive model. Asymmetric information In many real-life situations, the assumption of perfect information is unrealistic. An employer does not necessarily know how hard workers are working or how productive they are. This provides an incentive for workers to shirk from providing their full effort, called moral hazard. Since it is difficult for the employer to identify the hard-working and the shirking employees, there is no incentive to work hard and productivity falls overall, leading to the hiring of more workers and a lower unemployment rate. One solution that is used to avoid a moral hazard is stock options that grant employees the chance to benefit directly from a firm's success. However, this solution has attracted criticism as executives with large stock-option packages have been suspected of acting to over-inflate share values to the detriment of the long-run welfare of the firm. Another solution, foreshadowed by the rise of temporary workers in Japan and the firing of many of these workers in response to the financial crisis of 2008, is more flexible job- contracts and -terms that encourage employees to work less than full-time by partially compensating for the loss of hours, relying on workers to adapt their working time in response to job requirements and economic conditions instead of the employer trying to determine how much work is needed to complete a given task and overestimating. Another aspect of uncertainty results from the firm's imperfect knowledge about worker ability. If a firm is unsure about a worker's ability, it pays a wage assuming that the worker's ability is the average of similar workers. This wage under compensates high-ability workers which may drive them away from the labour market as well as at the same time attracting low-ability workers. Such a phenomenon, called adverse selection, can sometimes lead to market collapse. One way to combat adverse selection, firms will try to use signalling, pioneered by Michael Spence, whereby employers could use various characteristics of applicants differentiate between high-ability or low-ability workers. One common signal used is education, whereby employers assume that high-ability workers will have higher levels of education. Employers can then compensate high-ability workers with higher wages. However, signalling does not always work, and it may appear to an external observer that education has raised the marginal product of labour, without this necessarily being true. Search models One of the major research achievements of the 1990-2010 period was the development of a framework with dynamic search, matching, and bargaining. Personnel economics: hiring and incentives At the micro level, one sub-discipline eliciting increased attention in recent decades is analysis of internal labour markets, that is, within firms (or other organisations), studied in personnel economics from the perspective of personnel management. By contrast, external labour markets "imply that workers move somewhat fluidly between firms and wages are determined by some aggregate process where firms do not have significant discretion over wage setting." The focus is on "how firms establish, maintain, and end employment relationships and on how firms provide incentives to employees," including models and empirical work on incentive systems and as constrained by economic efficiency and risk/incentive tradeoffs relating to personnel compensation. Discrimination and inequality Inequality and discrimination in the workplace can have many effects on workers. In the context of labour economics, inequality is usually referring to the unequal distribution of earning between households. Inequality is commonly measured by economists using the Gini coefficient. This coefficient does not have a concrete meaning but is more used as a way to compare inequality across regions. The higher the Gini coefficient is calculated to be the larger inequality exists in a region. Over time, inequality has, on average, been increasing. This is due to numerous factors including labour supply and demand shifts as well as institutional changes in the labour market. On the shifts in labour supply and demand, factors include demand for skilled workers going up more than the supply of skilled workers and relative to unskilled workers as well as technological changes that increase productivity; all of these things cause wages to go up for skilled labour while unskilled worker wages stay the same or decline. As for the institutional changes, a decrease in union power and a declining real minimum wage, which both reduce unskilled workers wages, and tax cuts for the wealthy all increase the inequality gap between groups of earners. As for discrimination, it is the difference in pay that can be attributed to the demographic differences between people, such as gender, race, ethnicity, religion, sexual orientation, etc, even though these factors do not affect the productivity of the worker. Many regions and countries have enacted government policies to combat discrimination, including discrimination in the workplace. Discrimination can be modelled and measured in numerous ways. The oaxaca decomposition is a common method used to calculate the amount of discrimination that exists when wages differ between groups of people. This decomposition aims to calculate the difference in wages that occurs because of differences in skills versus the returns to those skills. A way of modelling discrimination in the workplace when dealing with wages are Gary Becker's taste models. Using taste models, employer discrimination can be thought of as the employer not hiring the minority worker because of their perceived cost of hiring that worker is higher than that of the cost of hiring a non-minority worker, which causes less hiring of the minority. Another taste model is for employee discrimination, which does not cause a decline in the hiring of minorities, but instead causes a more segregated workforce because the prejudiced worker feels that they should be paid more to work next to the worker they are prejudiced against or that they are not paid an equal amount as the worker they are prejudiced against. One more taste model involves customer discrimination, whereby the employers themselves are not prejudiced but believe that their customers might be, so therefore the employer is less likely to hire the minority worker if they are going to interact with customers that are prejudiced. There are many other taste models other than these that Gary Becker has made to explain discrimination that causes differences in hiring in wages in the labour market. Criticisms Many sociologists, political economists, and heterodox economists claim that labour economics tends to lose sight of the complexity of individual employment decisions. These decisions, particularly on the supply side, are often loaded with considerable emotional baggage and a purely numerical analysis can miss important dimensions of the process, such as social benefits of a high income or wage rate regardless of the marginal utility from increased consumption or specific economic goals. From the perspective of mainstream economics, neoclassical models are not meant to serve as a full description of the psychological and subjective factors that go into a given individual's employment relations, but as a useful approximation of human behaviour in the aggregate, which can be fleshed out further by the use of concepts such as information asymmetry, transaction costs, contract theory etc. Also missing from most labour market analyses is the role of unpaid labour such as unpaid internships where workers with little or no experience are allowed to work a job without pay so that they can gain experience in a particular profession. Even though this type of labour is unpaid it can nevertheless play an important part in society if not abused by employers. The most dramatic example is child raising. However, over the past 25 years an increasing literature, usually designated as the economics of the family, has sought to study within household decision making, including joint labour supply, fertility, child-raising, as well as other areas of what is generally referred to as home production. Wage slavery The labour market, as institutionalised under today's market economic systems, has been criticised, especially by both mainstream socialists and anarcho-syndicalists, who utilise the term wage slavery as a pejorative for wage labour. Socialists draw parallels between the trade of labour as a commodity and slavery. Cicero is also known to have suggested such parallels. According to Noam Chomsky, analysis of the psychological implications of wage slavery goes back to the Enlightenment era. In his 1791 book On the Limits of State Action, classical liberal thinker Wilhelm von Humboldt explained how "whatever does not spring from a man's free choice, or is only the result of instruction and guidance, does not enter into his very nature; he does not perform it with truly human energies, but merely with mechanical exactness" and so when the labourer works under external control, "we may admire what he does, but we despise what he is." Both the Milgram and Stanford experiments have been found useful in the psychological study of wage-based workplace relations. The American philosopher John Dewey posited that until "industrial feudalism" is replaced by "industrial democracy," politics will be "the shadow cast on society by big business". Thomas Ferguson has postulated in his investment theory of party competition that the undemocratic nature of economic institutions under capitalism causes elections to become occasions when blocs of investors coalesce and compete to control the state. As per anthropologist David Graeber, the earliest wage labour contracts we know about were in fact contracts for the rental of chattel slaves (usually the owner would receive a share of the money, and the slave, another, with which to maintain his or her living expenses.) Such arrangements, according to Graeber, were quite common in New World slavery as well, whether in the United States or Brazil. C. L. R. James argued that most of the techniques of human organisation employed on factory workers during the industrial revolution were first developed on slave plantations. Additionally, Marxists posit that labour-as-commodity, which is how they regard wage labour, provides an absolutely fundamental point of attack against capitalism. "It can be persuasively argued," noted one concerned philosopher, "that the conception of the worker's labour as a commodity confirms Marx's stigmatisation of the wage system of private capitalism as 'wage-slavery;' that is, as an instrument of the capitalist's for reducing the worker's condition to that of a slave, if not below it." See also References Further reading Richard Blundell and Thomas MaCurdy, 2008. "labour supply," The New Palgrave Dictionary of Economics, 2nd Edition Abstract. Freeman, R.B., 1987. "Labour economics," The New Palgrave: A Dictionary of Economics, v. 3, pp. 72–76. John R. Hicks, 1932, 2nd ed., 1963. The Theory of Wages. London, Macmillan. Handbook of Labor Economics. Elsevier. Amsterdam: North-Holland. Links to one-page chapter previews for each volume: Orley C. Ashenfelter and Richard Layard, ed., 1986, v. 1 & 2; Orley Ashenfelter and David Card, ed., 1999, v. 3A, 3B, and 3C Orley Ashenfelter and David Card, ed., 2011, v. 4A & 4B. Mark R. Killingsworth, 1983. Labour Supply. Cambridge: Cambridge Surveys of Economic Literature. Jacob Mincer, 1974. Schooling, Experience, and Earnings. New York: Columbia University Press. Anindya Bakrie & Morendy Octora, 2002. Schooling, Experience, and Earnings. New York, Singapore National University : Columbia University Press. Simon Head, The New Ruthless Economy. Work and Power in the Digital Age, Oxford UP 2005, External links Ageing workers EU-OSHA The Labour Economics Gateway – Collection of Internet sites that are of interest to labour economists Labour & Worklife Program at Harvard Law School, Changing Labour Markets Project W.E. Upjohn Institute for Employment Research ILO: Key Indicators of the Labour Market (KILM). 5. ed. Sept. 2007 LabourFair Resources – Link to Fair Labour Practices Labour Research Network – Labour research programme treating various fields Labour Research Department – Independent labour economics research organisation Factors of production	[ 0.2841017544269562, 0.16870936751365662, -0.03502578288316727, 0.05445996671915054, -0.06362877786159515, 0.6846312284469604, -0.2240985929965973, 0.2764648497104645, -0.3558829128742218, -0.6579632759094238, -0.36045825481414795, 0.8120411038398743, -0.29175183176994324, 0.430140942335128...
18179	https://en.wikipedia.org/wiki/Lammas	Lammas	Lammas Day (Anglo-Saxon hlaf-mas, "loaf-mass"), also known as Loaf Mass Day, is a Christian holiday celebrated in some English-speaking countries in the Northern Hemisphere on 1 August. The name originates from the word "loaf" in reference to bread and "Mass" in reference to the primary Christian liturgy celebrating Holy Communion. It is a festival in the liturgical calendar to mark the blessing of the First Fruits of harvest, with a loaf of bread being brought to the church for this purpose. On Loaf Mass Day, it is customary to bring to a Christian church a loaf made from the new crop, which began to be harvested at Lammastide, which falls at the halfway point between the summer solstice and autumn September equinox. Christians also have church processions to bakeries, where those working therein are blessed by Christian clergy. Lammas has coincided with the feast of St. Peter in Chains, commemorating St. Peter's miraculous deliverance from prison, but in the liturgical reform of 1969 the feast of St. Alphonsus Liguori was transferred to this day, the day of St. Alphonsus' death. While Loaf Mass Day is traditionally a Christian holy day, Lughnasadh is celebrated by Neopagans around the same time. History Ann Lewin explains a key practice of the Christian feast of Lammas (Loaf Mass Day) and its importance in the Christian Calendar in relation to other feasts of the Church Year: In the Church of England, the mother church of the Anglican Communion, during the celebration of Holy Communion, "The Lammas loaf, or part of it, may be used as the bread of the Eucharist, or the Lammas loaf and the eucharistic bread may be kept separate." The loaf is blessed and in Anglo-Saxon England it might be employed afterwards in protective rituals: a book of Anglo-Saxon charms directed that the Lammas bread be broken into four parts, which were to be placed at the four corners of the barn, to protect the garnered grain. In many parts of England, tenants were bound to present freshly harvested wheat to their landlords on or before the first day of August. In the Anglo-Saxon Chronicle, where it is referred to frequently, it is called "the feast of first fruits". The blessing of first fruits was performed annually in both the Eastern and Western churches on the 1st or the 6th of August (the latter being the feast of the Transfiguration of Christ). In medieval times the feast was sometimes known in England and Scotland as the "Gule of August", but the meaning of "gule" is unclear. Ronald Hutton suggests following the 18th-century Welsh clerical antiquary John Pettingall that it is merely an anglicisation of , Welsh for "feast of August". The OED and most etymological dictionaries give it a more circuitous origin similar to gullet; from Old French , a diminutive of , "throat, neck," from Latin "throat". Several antiquaries beginning with John Brady offered a back-construction to its being originally known as Lamb-mass, under the undocumented supposition that tenants of the Cathedral of York, dedicated to St. Peter ad Vincula, of which this is the feast, would have been required to bring a live lamb to the church, or, with John Skinner, "because Lambs then grew out of season." This is a folk etymology, of which OED notes that it was "subsequently felt as if from LAMB + MASS". For many villeins, the wheat must have run low in the days before Lammas, and the new harvest began a season of plenty, of hard work and company in the fields, reaping in teams. Thus there was a spirit of celebratory play. In the medieval agricultural year, Lammas also marked the end of the hay harvest that had begun after Midsummer. At the end of hay-making a sheep would be loosed in the meadow among the mowers, for him to keep who could catch it. In Shakespeare's Romeo and Juliet (1.3.19) it is observed of Juliet, "Come Lammas Eve at night shall she [Juliet] be fourteen." Since Juliet was born on Lammas Eve, she came before the harvest festival, which is significant since her life ended before she could reap what she had sown, as blessed by the Friar Francisco, by consummating her marriage: Another well-known cultural reference is the opening of The Battle of Otterburn: "It fell about the Lammas tide when the muir-men win their hay." William Hone speaks in The Every-Day Book (1838) of a later festive Lammas Day sport common among Scottish farmers near Edinburgh. He says that they "build towers ... leaving a hole for a flag-pole in the centre so that they may raise their colours." When the flags over the many peat-constructed towers were raised, farmers would go to others' towers and attempt to "level them to the ground." A successful attempt would bring great praise. However, people were allowed to defend their towers, and so everyone was provided with a "tooting-horn" to alert nearby country folk of the impending attack and the battle would turn into a "brawl". According to Hone, more than four people had died at this festival and many more were injured. At the day's end, races were held, with prizes given to the townspeople. Other uses Neopaganism Lughnasadh is the name used for one of the eight sabbats in the Neopagan Wheel of the Year. It is the first of the three autumn harvest festivals, the other two being the autumn equinox (also called Mabon) and Samhain. In the Northern Hemisphere it takes place around 1 August, while in the Southern Hemisphere it is celebrated around 1 February. To the members of the Asatru faith, Lammas is known as Freyfaxi, as it refers to a festival held during Old Norse times when a horse is sacrificed as an offering to Freyr. The name comes from the Old Norse words for "Freyr's horse mane", most likely referring to the deity's steed Blóðughófi. Scottish quarter days Lammas Day was one of the traditional Scottish quarter days (before 1886). Horticulture Lammas leaves or Lammas growth refers to a second crop of leaves produced in high summer by some species of trees in temperate countries to replace those lost to insect damage. They often differ slightly in shape, texture and/or hairiness from the earlier leaves. A low-impact development project at Tir y Gafel, Glandwr, Pembrokeshire, Lammas Ecovillage, is a collective initiative for nine self-built homes. It was the first such project to obtain planning permission based on a predecessor of what is now the sixth national planning guidance for sustainable rural communities originally proposed by the One Planet Council. Exeter in Devon is one of the few towns in England that still celebrates its Lammas Fair and has a processional custom which stretches back over 900 years, led by the Lord Mayor. During the fair a white glove on a pole decorated with garlands is raised above the Guildhall. The fair now takes place on the first Thursday in July. In popular culture The Doctor Who serial The Image of the Fendahl takes place on Lammas Eve. In the Inspector Morse episode "Day of the Devil", Lammas Day is presented as a Satanic (un)holy day, "the Devil's day". Katherine Kurtz's alternate World War II fantasy "history" takes its title, Lammas Night, from pagan tradition surrounding the first of August and the Divine Right of Kings. The English football club Staines Lammas F.C. is named for a local field. The Song "Corn Rigs" by Paul Giovanni, from the soundtrack to the 1973 film The Wicker Man, takes place "upon a Lammas Night". See also Plough Sunday Rogation days Leyton Marshes Ould Lammas Fair References External links Lammastide - The Church of England Lammas Day - Full Homely Divinity Observations on Popular Antiquities Christian festivals in Europe Christian processions August observances Holidays in Scotland Scottish quarter days February observances Summer holidays cy:Gŵyl Galan Awst	[ 0.3664477467536926, 0.13153076171875, 0.4032052457332611, -1.0670102834701538, -0.21695056557655334, 0.3639165759086609, 0.469819039106369, 0.720434844493866, -0.6494234800338745, -0.1322188675403595, -0.6599275469779968, 0.29134875535964966, 0.3895607590675354, -0.050756826996803284, -0...
18182	https://en.wikipedia.org/wiki/Longmeadow%2C%20Massachusetts	Longmeadow, Massachusetts	Longmeadow is a town in Hampden County, Massachusetts, in the United States. The population was 15,853 at the 2020 census. History Longmeadow was first settled in 1644, and officially incorporated October 17, 1783. The town was originally farmland within the limits of Springfield. It remained relatively pastoral until the street railway was built , when the population tripled over a fifteen-year period. After Interstate 91 was built in the wetlands on the west side of town, population tripled again between 1960 and 1975. During the 19th and early 20th centuries, Longmeadow was best known as the site from which Longmeadow brownstone was mined. Several famous American buildings, including Princeton University's Neo-Gothic library, are made of Longmeadow brownstone. In 1894, the more populous and industrialized "East Village" portion of the town containing the brownstone quarries split off to become East Longmeadow. Designed by famed golf course architect Donald Ross in 1922, the Longmeadow Country Club was the proving ground for golf equipment designed and manufactured by the Spalding Co. of Chicopee. Bobby Jones, a consultant for Spalding, was a member in standing at LCC and made a number of his instructional films at LCC in the 1930s. Geography Longmeadow is located in the western part of the state, just south of the city of Springfield, and is bordered on the west by the Connecticut River and Agawam, to the east by East Longmeadow, and to the south by Enfield, Connecticut. It extends approximately north to south and east to west. It is approximately north of Hartford. More than 30% of the town is permanent open space. Conservation areas on the west side of town include more than bordering the Connecticut River. The area supports a wide range of wildlife including deer, beaver, wild turkeys, foxes, and eagles. Springfield's Forest Park, which at is the largest city park in New England, forms the northern border of the town. The private Twin Hills and public Franconia golf courses, plus town athletic fields and conservation land, cover nearly 2/3 of the eastern border of the town. Two large public parks, the Longmeadow Country Club, and three conservation areas account for the bulk of the remaining formal open space. Almost 20% of the houses in town are in proximity to a "dingle", a tree-lined steep-sided sandy ravine with a wetland at the bottom that provides a privacy barrier between yards. Longmeadow has a town common, commonly referred to as "The Green" , located along U.S. Route 5 on the west side of town. It is about long. Roughly 100 houses date back before 1900, most of which are in the historic district, are located near the town green. Longmeadow's Town Green is a historic district on the National Register of Historic Places, and it is surrounded by a number of buildings dating back to the 18th and 19th centuries. Longmeadow is unique as the town green has maintained its residential purpose and has resisted commercial pressure. The current function as listed by the National Register of Historic Places is domestic and landscape. The current sub-function as listed by the National Register of Historic Places is park and single dwelling. Houses along the photogenic main street (Longmeadow Street) are set back farther than in most towns of similar residential density.The town has three recently remodeled elementary schools, two secondary schools, and one high school. The commercial center of town is an area called "The Longmeadow Shops" , including restaurants and clothing stores. According to the United States Census Bureau, the town has a total area of , of which are land and , or 5.34%, are water. Demographics As of the census of 2000, there were 15,633 people, 5,734 households, and 4,432 families residing in the town. The population density was . There were 5,879 housing units at an average density of . The racial makeup of the town was 95.42% White, 0.69% African American, 0.05% Native American, 2.90% Asian, 0.06% Pacific Islander, 0.26% from other races, and 0.62% from two or more races. Hispanic or Latino of any race were 1.09% of the population. There were 5,734 households, out of which 37.1% had children under the age of 18 living with them, 69.1% were married couples living together, 6.4% had a female householder with no husband present, and 22.7% were non-families. 20.4% of all households were made up of individuals, and 14.0% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.09. In the town, the population was spread out, with 26.8% under the age of 18, 4.6% from 18 to 24, 22.0% from 25 to 44, 28.7% from 45 to 64, and 17.8% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 87.7 males. For every 100 females age 18 and over, there were 82.0 males. The median income for a household in the town was $109,586, and the median income for a family was $115,578. Males had a median income of $68,238 versus $40,890 for females. The per capita income for the town was $48,949. About 1.0% of families and 2.1% of the population were below the poverty line, including 0.3% of those under age 18 and 8.3% of those age 65 or over . Government The town is chartered as an Open Town Meeting form of government. The town government also consists of a Select Board with five members, elected by the town. The public school system is governed by the School Committee. The School Committee is made up of seven voting members elected by the town, the superintendent of schools, two assistant-superintendents, a secretary, and a student representative. Education The Longmeadow public school system operates six schools. Blueberry Hill School, Center School, and Wolf Swamp Road School are K−5 elementary schools. Williams Middle School and Glenbrook Middle School serve grades 6–8. Longmeadow High School serves all students in the town between grades 9 and 12. The town's elementary schools have been recently rebuilt, statements of interest for improvements to the two middle schools and Longmeadow High School were filed with the Massachusetts School Building Authority in 2007. In 2010, the voters of Longmeadow approved a 2.5% budget override to support the construction of a new $78 million high school. The town received an estimated $34 million in state funds to be used towards the new construction The new High School was completed and opened to students on February 26, 2013. After students and faculty had moved into the new school, the demolition of the old school was begun. The demolition was completed by June 2013. The school had its grand opening in September 2013 with both the brand new school and renovated business & administration wing open. Longmeadow also hosts two private parochial schools, the Lubavitcher Yeshiva Academy (LYA) and St. Mary's Academy. LYA was established in 1946 in response to the Greater Springfield Jewish community's need for a quality Jewish day school. In 1999, LYA became the first Jewish day school to be accredited by the New England Association of Schools and Colleges (NEASC). The more than 90 students that the school serves each year from across the spectrum of Jewish life include orthodox, conservative, reform, and unaffiliated families. St. Mary's Academy, located behind St. Mary's Church, serves Catholic students grades Pre-K through Grade 8. Approximately 50% of the students at Longmeadow High School participate in the music program. The choruses have won numerous gold medals at the MICCA competition. The jazz ensemble has won numerous gold medals as well, but no longer competes. The honors chorus "Lyrics" has won numerous awards and has traveled to many places around the world on tours, such as Italy and Sweden. The wind ensemble and symphony orchestra have had the honor of performing in Indianapolis, Boston (Boston Symphony Hall), and New York (Carnegie Hall). In 2010, Longmeadow was awarded The American Prize in Orchestral Performance. The music program's crowning achievement has been receiving three national Grammy Awards based on the high level of excellence maintained throughout all groups in the music program. Longmeadow also contains the 46-acre primary campus for Bay Path University, a private undergraduate and graduate institution. Notable people Terri Alden, fictional nurse Barry Almeida, professional hockey player. Mary Ann Booth, microscopist Craig E. Campbell, Alaska's lieutenant governor and retired Alaska National Guard lieutenant general John Chapman (Johnny Appleseed), pioneer nurseryman who introduced apple trees to large parts of Ohio, Indiana, and Illinois David Cohen (1917-2020), a member of the US Army, a liberator of the Ohrdruf concentration camp, and a schoolteacher. J. H. Colton, leading 19th Century cartographer Bianca D'Agostino, former soccer player John Deluca, actor (Butchy in Teen Beach Movie) Damien Fahey, MTV VJ and host of Total Request Live Meghann Fahy, Sutton on Freeform's The Bold Type, One Life to Live character Hannah, Natalie on Broadway's Next to Normal Paul Fenton, Former NHL GM for the Minnesota Wild and scout Jonathan Green, British author and journalist Jay Heaps, former player and manager for New England Revolution of Major League Soccer Nathan Cooley Keep, pioneer in field of dentistry, founding dean of Harvard School of Dental Medicine Andrew Lam, author and retinal surgeon Eric Lesser, Massachusetts State Senator Aaron Lewis, guitarist and vocalist for band Staind Chirlane McCray, African-American writer and activist, wife of NYC mayor Bill de Blasio Bridget Moynahan, model and actress, star of films and TV series Blue Bloods Joe Philbin, NFL coach, former head coach of Miami Dolphins Joey Santiago, lead guitarist for influential alternative rock band Pixies Anita Shreve, award-winning writer Jim Sleeper, author and journalist Brynn Cartelli, winner of the 14th season of The Voice Erinn Bartlett, actress (Deep Blue Sea, The In Crowd) References External links Town of Longmeadow official website Towns in Hampden County, Massachusetts Springfield metropolitan area, Massachusetts Massachusetts populated places on the Connecticut River Towns in Massachusetts 1644 establishments in Massachusetts Populated places established in 1644	[ -0.6995331645011902, 0.297155499458313, 0.19340717792510986, -0.4466865658760071, 0.29785802960395813, 0.1269625574350357, 0.3074943423271179, 0.9741982817649841, -0.5015271902084351, 0.07381042093038559, -0.4633257985115051, 0.004487335216253996, -0.08032336831092834, 0.807663083076477, ...
18183	https://en.wikipedia.org/wiki/Body%20relative%20direction	Body relative direction	Body relative directions (also known as egocentric coordinates) are geometrical orientations relative to a body such as a human person's. The most common ones are: left and right; forward(s) and backward(s); up and down. They form three pairs of orthogonal axes. Traditions and conventions Since definitions of left and right based on the geometry of the natural environment are unwieldy, in practice, the meaning of relative direction words is conveyed through tradition, acculturation, education, and direct reference. One common definition of up and down uses gravity and the planet Earth as a frame of reference. Since there is a very noticeable force of gravity acting between the Earth and any other nearby object, down is defined as that direction which an object moves in reference to the Earth when the object is allowed to fall freely. Up is then defined as the opposite direction of down. Another common definition uses a human body, standing upright, as a frame of reference. In that case, up is defined as the direction from feet to head, perpendicular to the surface of the Earth. In most cases, up is a directionally oriented position generally opposite to that of the pull of gravity. In situations where a common frame of reference is needed, it is most common to use an egocentric view. A simple example is road signage. Another example is stage blocking, where "stage left" "stage right" are, by convention, defined from the point of view of actors facing the audience. "Upstage" and "downstage" do not follow gravity but by convention mean away from and towards the audience. An example of a non-egocentric view is page layout, where the relative terms "upper half" "left margin," etc. are defined in terms of the observer but employed in reverse for a type compositor, returning to an egocentric view. In medicine and science, where precise definitions are crucial, relative directions (left and right) are the sides of the organism, not those of the observer. The same is true in heraldry, where left and right in a coat of arms is treated as if the shield were being held by the armiger. To avoid confusion, Latin terminology is employed: dexter and sinister for right and left. Proper right and proper left are terms mainly used to describe artistic images, and overcome the potential confusion that a figure's "own" right or "proper right" hand is on the left hand as the viewer sees it from the front. Forward and backward may be defined by referring to an object's or person's motion. Forward is defined as the direction in which the object is moving. Backward is then defined as the opposite direction to forward. Alternatively, 'forward' may be the direction pointed by the observer's nose, defining 'backward' as the direction from the nose to the sagittal border in the observer's skull. With respect to a ship 'forward' would indicate the relative position of any object lying in the direction the ship is pointing. For symmetrical objects, it is also necessary to define forward and backward in terms of expected direction. Many mass transit trains are built symmetrically with paired control booths, and definitions of forward, backward, left, and right are temporary. Given significant distance from the magnetic poles, one can figure which hand is which using a magnetic compass and the sun. Facing the sun, before noon, the north pointer of the compass points to the "left" hand. After noon, it points to the "right". Geometry of the natural environment A right-hand rule is one common way to relate three principal directions. For many years a fundamental question in physics was whether a left-hand rule would be equivalent. Many natural structures, including human bodies, follow a certain "handedness", but it was widely assumed that nature did not distinguish the two possibilities. This changed with the discovery of parity violations in particle physics. If a sample of cobalt-60 atoms is magnetized so that they spin counterclockwise around some axis, the beta radiation resulting from their nuclear decay will be preferentially directed opposite that axis. Since counter-clockwise may be defined in terms of up, forward, and right, this experiment unambiguously differentiates left from right using only natural elements: if they were reversed, or the atoms spun clockwise, the radiation would follow the spin axis instead of being opposite to it. Nautical terminology Bow, stern, port, and starboard, fore and aft are nautical terms that convey an impersonal relative direction in the context of the moving frame of persons aboard a ship. The need for impersonal terms is most clearly seen in a rowing shell where the majority of the crew face aft ("backwards"), hence the oars to their right are actually on the port side of the boat. Rowers eschew the terms left, right, port and starboard in favor of stroke-side and bow-side. The usage derives from the tradition of having the stroke (the rower closest to the stern of the boat) oar on the port side of the boat. Cultures without relative directions Most human cultures use relative directions for reference, but there are exceptions. Australian Aboriginal peoples like the Guugu Yimithirr, Kaiadilt and Thaayorre have no words denoting the egocentric directions in their language; instead, they exclusively refer to cardinal directions, even when describing small-scale spaces. For instance, if they wanted someone to move over on the car seat to make room, they might say "move a bit to the east". To tell someone where exactly they left something in their house, they might say, "I left it on the southern edge of the western table." Or they might warn a person to "look out for that big ant just north of your foot". Other peoples "from Polynesia to Mexico and from Namibia to Bali" similarly have predominantly "geographic languages". American Sign Language makes heavy use of geographical direction through absolute orientation. Left-right discrimination and left-right confusion Left-right discrimination (LRD) refers to a person's ability to differentiate between left and right. The inability to accurately differentiate between left and right is known as left-right confusion (LRC). According to research performed by John R. Clarke of Drexel University, LRC affects approximately 15% of the population. People who suffer from LRC can typically perform daily navigational tasks, such as driving according to road signs or following a map, but may have difficulty performing actions that require a precise understanding of directional commands, such as ballroom dancing. Prevalence Data regarding LRC prevalence is primarily based on behavioral studies, self-assessments, and surveys. Gormley and Brydges found that in a group of 800 adults, 17% of women and 9% of men reported difficulty differentiating between left and right. Such studies suggest that women are more prone to LRC than men, with women reporting higher rates of LRC in both accuracy and speed of response. Sex differences The Bergen Left-Right Discrimination (BLRD) test is designed to measure individual performance in LRD accuracy. However, this test has been criticized for incorporating tasks that require the use of additional strategies, such as mental rotation (MR). Because men have been shown to consistently outperform women in MR tasks, tests involving the use of this particular strategy may present alternative cognitive demands and lead to inaccurate assessment of LRD performance. An extended version of the BLRD test was designed to allow for differential evaluation of LRD and MR abilities, in which subtests were created with either high or low demands on mental rotation. Results from these studies did not find sex differences in LRD performance when mental rotation demands were low. Another study found that sex differences in left-right discrimination existed in terms of self-reported difficulty, but not in actual tested ability. Alternatively, studies focused on LRD as a phenomenon distinct from MR concluded that there are sex differences present in LRD. Scientists controlled for MR demands, potential menstrual cycle effects, and other hormone fluctuations, and determined that the neurocognitive mechanisms that support LRD are different for men and women. This research revealed that inferior parietal and right angular gyrus activation were correlated with LRD performance in both men and women. Women also demonstrated increased prefrontal activation, but did not exhibit greater bilateral activation. Additionally, no correlation was found between LRD accuracy and brain activation, or between brain activation and reaction time, for either sex. These results indicate that there are sex differences in the neurocognitive mechanisms underlying LRD performance; however, findings did not suggest that women are more prone to LRC than men. Acquisition and comparison Humans are constantly making decisions about spatial relations; however, some spatial relations, such as left-right, are commonly confused, while other spatial relations, such as up-down, above-below, and front-back, are seldom, if ever, mistaken. The ability to categorize and compartmentalize space is an essential tool for navigating this 3D world; an ability shown to develop in early infancy. Infant ability to visually match above-below and left-right relations appears to diminish in early toddlerhood, as language acquisition may complicate verbal labeling. Children learn to verbally discriminate between above-below relations around the age of three, and learn left-right linguistic labels between the ages of six and seven; however, these classifications may only exist in the linguistic context. In other words, children may learn the terms for left and right without having developed a cognitive representation to allow for the accurate application of such spatial distinctions. Research seeks to explain the neural activity associated with left-right discrimination, attempting to identify differences in the encoding, consolidation, and retrieval of left-right versus above-below relations. One study found that neural activity patterns for left-right and above-below distinctions are represented differently in the brain, leading to the theory that these spatial judgements are supported by separate cognitive mechanisms. Experiments used magnetoencephalography (MEG) to record neural activity during a computerized nonverbal task, examining left-right and above-below differences in encoding and working memory. Results showed differences in neural activity patterns in the right cerebellum, right superior temporal gyrus, and left temporoparietal junction during the encoding phase, and indicated differential neural activity in the inferior parietal, right superior temporal, and right cerebellum regions in the working memory tests. The role of distraction Although some individuals may struggle with LRD more than others, discriminating between left and right in the face of distraction has been shown to impair even the most proficient individual's ability to accurately differentiate between the two. This issue is of particular importance to medical students, clinicians and health care professionals, where distraction in the workplace and LRD inaccuracy can lead to severe consequences, including laterality errors and wrong-side surgeries. Laterality errors in the field of aviation may also lead to equally devastating results, for example, causing a major airline crash. Distraction has a significant impact on LRD accuracy, and the type of distraction can alter the magnitude of these effects. For example, cognitive distraction, which occurs when an individual is not directly focused on the task at hand, has a more profound effect on LRD performance than auditory distraction, such as the presence of continuous ambient noise. Additionally, in the field of health care, it has been noted that mental rotation is often involved in making left-right distinctions, such as when a medical practitioner is facing their patient and must adjust for the opposite left-right relations. See also Anatomical terms of location Cardinal direction Cerebral hemisphere Clock position Dexter and sinister Horizontal direction Dextral and sinistral Handedness List of international common standards Orientation (geometry) Port and starboard Rotation Sense of direction Slant direction Windward and leeward References Orientation (geometry)	[ -0.017609110102057457, -0.20330865681171417, 0.2841580808162689, 0.03376955911517143, -0.32800865173339844, 0.26533326506614685, 0.11620458960533142, 0.3573980927467346, 0.13926906883716583, -0.6240090727806091, -0.20930780470371246, 0.582003653049469, -0.0747777670621872, 0.15193270146846...
18184	https://en.wikipedia.org/wiki/Lizard	Lizard	Lizards (suborder Lacertilia) are a widespread group of squamate reptiles, with over 6,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic as it excludes the snakes and Amphisbaenia; some lizards are more closely related to these two excluded groups than they are to other lizards. Lizards range in size from chameleons and geckos a few centimeters long to the 3 meter long Komodo dragon. Most lizards are quadrupedal, running with a strong side-to-side motion. Some lineages (known as "legless lizards"), have secondarily lost their legs, and have long snake-like bodies. Some such as the forest-dwelling Draco lizards are able to glide. They are often territorial, the males fighting off other males and signalling, often with brightly colours, to attract mates and to intimidate rivals. Lizards are mainly carnivorous, often being sit-and-wait predators; many smaller species eat insects, while the Komodo eats mammals as big as water buffalo. Lizards make use of a variety of antipredator adaptations, including venom, camouflage, reflex bleeding, and the ability to sacrifice and regrow their tails. Anatomy Largest and smallest The adult length of species within the suborder ranges from a few centimeters for chameleons such as Brookesia micra and geckos such as Sphaerodactylus ariasae to nearly in the case of the largest living varanid lizard, the Komodo dragon. Most lizards are fairly small animals. Distinguishing features Lizards typically have rounded torsos, elevated heads on short necks, four limbs and long tails, although some are legless. Lizards and snakes share a movable quadrate bone, distinguishing them from the rhynchocephalians, which have more rigid diapsid skulls. Some lizards such as chameleons have prehensile tails, assisting them in climbing among vegetation. As in other reptiles, the skin of lizards is covered in overlapping scales made of keratin. This provides protection from the environment and reduces water loss through evaporation. This adaptation enables lizards to thrive in some of the driest deserts on earth. The skin is tough and leathery, and is shed (sloughed) as the animal grows. Unlike snakes which shed the skin in a single piece, lizards slough their skin in several pieces. The scales may be modified into spines for display or protection, and some species have bone osteoderms underneath the scales. The dentitions of lizards reflect their wide range of diets, including carnivorous, insectivorous, omnivorous, herbivorous, nectivorous, and molluscivorous. Species typically have uniform teeth suited to their diet, but several species have variable teeth, such as cutting teeth in the front of the jaws and crushing teeth in the rear. Most species are pleurodont, though agamids and chameleons are acrodont. The tongue can be extended outside the mouth, and is often long. In the beaded lizards, whiptails and monitor lizards, the tongue is forked and used mainly or exclusively to sense the environment, continually flicking out to sample the environment, and back to transfer molecules to the vomeronasal organ responsible for chemosensation, analogous to but different from smell or taste. In geckos, the tongue is used to lick the eyes clean: they have no eyelids. Chameleons have very long sticky tongues which can be extended rapidly to catch their insect prey. Three lineages, the geckos, anoles, and chameleons, have modified the scales under their toes to form adhesive pads, highly prominent in the first two groups. The pads are composed of millions of tiny setae (hair-like structures) which fit closely to the substrate to adhere using van der Waals forces; no liquid adhesive is needed. In addition, the toes of chameleons are divided into two opposed groups on each foot (zygodactyly), enabling them to perch on branches as birds do. Physiology Locomotion Aside from legless lizards, most lizards are quadrupedal and move using gaits with alternating movement of the right and left limbs with substantial body bending. This body bending prevents significant respiration during movement, limiting their endurance, in a mechanism called Carrier's constraint. Several species can run bipedally, and a few can prop themselves up on their hindlimbs and tail while stationary. Several small species such as those in the genus Draco can glide: some can attain a distance of , losing in height. Some species, like geckos and chameleons, adhere to vertical surfaces including glass and ceilings. Some species, like the common basilisk, can run across water. Senses Lizards make use of their senses of sight, touch, olfaction and hearing like other vertebrates. The balance of these varies with the habitat of different species; for instance, skinks that live largely covered by loose soil rely heavily on olfaction and touch, while geckos depend largely on acute vision for their ability to hunt and to evaluate the distance to their prey before striking. Monitor lizards have acute vision, hearing, and olfactory senses. Some lizards make unusual use of their sense organs: chameleons can steer their eyes in different directions, sometimes providing non-overlapping fields of view, such as forwards and backwards at once. Lizards lack external ears, having instead a circular opening in which the tympanic membrane (eardrum) can be seen. Many species rely on hearing for early warning of predators, and flee at the slightest sound. As in snakes and many mammals, all lizards have a specialised olfactory system, the vomeronasal organ, used to detect pheromones. Monitor lizards transfer scent from the tip of their tongue to the organ; the tongue is used only for this information-gathering purpose, and is not involved in manipulating food. Some lizards, particularly iguanas, have retained a photosensory organ on the top of their heads called the parietal eye, a basal ("primitive") feature also present in the tuatara. This "eye" has only a rudimentary retina and lens and cannot form images, but is sensitive to changes in light and dark and can detect movement. This helps them detect predators stalking it from above. Venom Until 2006 it was thought that the Gila monster and the Mexican beaded lizard were the only venomous lizards. However, several species of monitor lizards, including the Komodo dragon, produce powerful venom in their oral glands. Lace monitor venom, for instance, causes swift loss of consciousness and extensive bleeding through its pharmacological effects, both lowering blood pressure and preventing blood clotting. Nine classes of toxin known from snakes are produced by lizards. The range of actions provides the potential for new medicinal drugs based on lizard venom proteins. Genes associated with venom toxins have been found in the salivary glands on a wide range of lizards, including species traditionally thought of as non-venomous, such as iguanas and bearded dragons. This suggests that these genes evolved in the common ancestor of lizards and snakes, some 200 million years ago (forming a single clade, the Toxicofera). However, most of these putative venom genes were "housekeeping genes" found in all cells and tissues, including skin and cloacal scent glands. The genes in question may thus be evolutionary precursors of venom genes. Respiration Recent studies (2013 and 2014) on the lung anatomy of the savannah monitor and green iguana found them to have a unidirectional airflow system, which involves the air moving in a loop through the lungs when breathing. This was previously thought to only exist in the archosaurs (crocodilians and birds). This may be evidence that unidirectional airflow is an ancestral trait in diapsids. Reproduction and lifecycle As with all amniotes, lizards rely on internal fertilisation and copulation involves the male inserting one of his hemipenes into the female's cloaca. The majority of species are oviparous (egg laying). The female deposits the eggs in a protective structure like a nest or crevice or simply on the ground. Depending on the species, clutch size can vary from 4–5 percent of the females body weight to 40–50 percent and clutches range from one or a few large eggs to dozens of small ones. In most lizards, the eggs have leathery shells to allow for the exchange of water, although more arid-living species have calcified shells to retain water. Inside the eggs, the embryos use nutrients from the yolk. Parental care is uncommon and the female usually abandons the eggs after laying them. Brooding and protection of eggs does occur in some species. The female prairie skink uses respiratory water loss to maintain the humidity of the eggs which facilitates embryonic development. In lace monitors, the young hatch close to 300 days, and the female returns to help them escape the termite mound where the eggs were laid. Around 20 percent of lizard species reproduce via viviparity (live birth). This is particularly common in Anguimorphs. Viviparous species give birth to relatively developed young which look like miniature adults. Embryos are nourished via a placenta-like structure. A minority of lizards have parthenogenesis (reproduction from unfertilised eggs). These species consist of all females who reproduce asexually with no need for males. This is known in occur in various species of whiptail lizards. Parthenogenesis was also recorded in species that normally reproduce sexually. A captive female Komodo dragon produced a clutch of eggs, despite being separated from males for over two years. Sex determination in lizards can be temperature-dependent. The temperature of the eggs' micro-environment can determine the sex of the hatched young: low temperature incubation produces more females while higher temperatures produce more males. However, some lizards have sex chromosomes and both male heterogamety (XY and XXY) and female heterogamety (ZW) occur. Behaviour Diurnality and thermoregulation The majority of lizard species are active during the day, though some are active at night, notably geckos. As ectotherms, lizards have a limited ability to regulate their body temperature, and must seek out and bask in sunlight to gain enough heat to become fully active. In high altitudes, the Podarcis hispaniscus responds to higher temperature with a darker dorsal coloration to prevent UV-radiation and background matching. Their thermoregulatory mechanisms also allow the lizard to maintain their ideal body temperature for optimal mobility. Territoriality Most social interactions among lizards are between breeding individuals. Territoriality is common and is correlated with species that use sit-and-wait hunting strategies. Males establish and maintain territories that contain resources which attract females and which they defend from other males. Important resources include basking, feeding, and nesting sites as well as refuges from predators. The habitat of a species affects the structure of territories, for example, rock lizards have territories atop rocky outcrops. Some species may aggregate in groups, enhancing vigilance and lessening the risk of predation for individuals, particularly for juveniles. Agonistic behaviour typically occurs between sexually mature males over territory or mates and may involve displays, posturing, chasing, grappling and biting. Communication Lizards signal both to attract mates and to intimidate rivals. Visual displays include body postures and inflation, push-ups, bright colours, mouth gapings and tail waggings. Male anoles and iguanas have dewlaps or skin flaps which come in various sizes, colours and patterns and the expansion of the dewlap as well as head-bobs and body movements add to the visual signals. Some species have deep blue dewlaps and communicate with ultraviolet signals. Blue-tongued skinks will flash their tongues as a threat display. Chameleons are known to change their complex colour patterns when communicating, particularly during agonistic encounters. They tend to show brighter colours when displaying aggression and darker colours when they submit or "give up". Several gecko species are brightly coloured; some species tilt their bodies to display their coloration. In certain species, brightly coloured males turn dull when not in the presence of rivals or females. While it is usually males that display, in some species females also use such communication. In the bronze anole, head-bobs are a common form of communication among females, the speed and frequency varying with age and territorial status. Chemical cues or pheromones are also important in communication. Males typically direct signals at rivals, while females direct them at potential mates. Lizards may be able to recognise individuals of the same species by their scent. Acoustic communication is less common in lizards. Hissing, a typical reptilian sound, is mostly produced by larger species as part of a threat display, accompanying gaping jaws. Some groups, particularly geckos, snake-lizards, and some iguanids, can produce more complex sounds and vocal apparatuses have independently evolved in different groups. These sounds are used for courtship, territorial defense and in distress, and include clicks, squeaks, barks and growls. The mating call of the male tokay gecko is heard as "tokay-tokay!". Tactile communication involves individuals rubbing against each other, either in courtship or in aggression. Some chameleon species communicate with one another by vibrating the substrate that they are standing on, such as a tree branch or leaf. Ecology Distribution and habitat Lizards are found worldwide, excluding the far north and Antarctica, and some islands. They can be found in elevations from sea level to . They prefer warmer, tropical climates but are adaptable and can live in all but the most extreme environments. Lizards also exploit a number of habitats; most primarily live on the ground, but others may live in rocks, on trees, underground and even in water. The marine iguana is adapted for life in the sea. Diet The majority of lizard species are predatory and the most common prey items are small, terrestrial invertebrates, particularly insects. Many species are sit-and-wait predators though others may be more active foragers. Chameleons prey on numerous insect species, such as beetles, grasshoppers and winged termites as well as spiders. They rely on persistence and ambush to capture these prey. An individual perches on a branch and stays perfectly still, with only its eyes moving. When an insect lands, the chameleon focuses its eyes on the target and slowly moves towards it before projecting its long sticky tongue which, when hauled back, brings the attach prey with it. Geckos feed on crickets, beetles, termites and moths. Termites are an important part of the diets of some species of Autarchoglossa, since, as social insects, they can be found in large numbers in one spot. Ants may form a prominent part of the diet of some lizards, particularly among the lacertas. Horned lizards are also well known for specializing on ants. Due to their small size and indigestible chitin, ants must be consumed in large amounts, and ant-eating lizards have larger stomachs than even herbivorous ones. Species of skink and alligator lizards eat snails and their power jaws and molar-like teeth are adapted for breaking the shells. Larger species, such as monitor lizards, can feed on larger prey including fish, frogs, birds, mammals and other reptiles. Prey may be swallowed whole and torn into smaller pieces. Both bird and reptile eggs may also be consumed as well. Gila monsters and beaded lizards climb trees to reach both the eggs and young of birds. Despite being venomous, these species rely on their strong jaws to kill prey. Mammalian prey typically consists of rodents and leporids; the Komodo dragon can kill prey as large as water buffalo. Dragons are prolific scavengers, and a single decaying carcass can attract several from away. A dragon is capable of consuming a carcass in 17 minutes. Around 2 percent of lizard species, including many iguanids, are herbivores. Adults of these species eat plant parts like flowers, leaves, stems and fruit, while juveniles eat more insects. Plant parts can be hard to digest, and, as they get closer to adulthood, juvenile iguanas eat faeces from adults to acquire the microflora necessary for their transition to a plant-based diet. Perhaps the most herbivorous species is the marine iguana which dives to forage for algae, kelp and other marine plants. Some non-herbivorous species supplement their insect diet with fruit, which is easily digested. Antipredator adaptations Lizards have a variety of antipredator adaptations, including running and climbing, venom, camouflage, tail autotomy, and reflex bleeding. Camouflage Lizards exploit a variety of different camouflage methods. Many lizards are disruptively patterned. In some species, such as Aegean wall lizards, individuals vary in colour, and select rocks which best match their own colour to minimise the risk of being detected by predators. The Moorish gecko is able to change colour for camouflage: when a light-coloured gecko is placed on a dark surface, it darkens within an hour to match the environment. The chameleons in general use their ability to change their coloration for signalling rather than camouflage, but some species such as Smith's dwarf chameleon do use active colour change for camouflage purposes. The flat-tail horned lizard's body is coloured like its desert background, and is flattened and fringed with white scales to minimise its shadow. Autotomy Many lizards, including geckos and skinks, are capable of shedding their tails (autotomy). The detached tail, sometimes brilliantly coloured, continues to writhe after detaching, distracting the predator's attention from the fleeing prey. Lizards partially regenerate their tails over a period of weeks. Some 326 genes are involved in regenerating lizard tails. The fish-scale gecko Geckolepis megalepis sheds patches of skin and scales if grabbed. Escape, playing dead, reflex bleeding Many lizards attempt to escape from danger by running to a place of safety; for example, wall lizards can run up walls and hide in holes or cracks. Horned lizards adopt differing defences for specific predators. They may play dead to deceive a predator that has caught them; attempt to outrun the rattlesnake, which does not pursue prey; but stay still, relying on their cryptic coloration, for Masticophis whip snakes which can catch even swift prey. If caught, some species such as the greater short-horned lizard puff themselves up, making their bodies hard for a narrow-mouthed predator like a whip snake to swallow. Finally, horned lizards can squirt blood at cat and dog predators from a pouch beneath its eyes, to a distance of about ; the blood tastes foul to these attackers. Evolution Fossil history The earliest known fossil remains of a lizard belong to the iguanian species Tikiguania estesi, found in the Tiki Formation of India, which dates to the Carnian stage of the Triassic period, about 220 million years ago. However, doubt has been raised over the age of Tikiguania because it is almost indistinguishable from modern agamid lizards. The Tikiguania remains may instead be late Tertiary or Quaternary in age, having been washed into much older Triassic sediments. Lizards are most closely related to the Rhynchocephalia, which appeared in the Late Triassic, so the earliest lizards probably appeared at that time. Mitochondrial phylogenetics suggest that the first lizards evolved in the late Permian. It had been thought on the basis of morphological data that iguanid lizards diverged from other squamates very early on, but molecular evidence contradicts this. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Early Cretaceous. Dolichosauridae is a family of Late Cretaceous aquatic varanoid lizards closely related to the mosasaurs. Phylogeny External The position of the lizards and other Squamata among the reptiles was studied using fossil evidence by Rainer Schoch and Hans-Dieter Sues in 2015. Lizards form about 60% of the extant non-avian reptiles. Internal Both the snakes and the Amphisbaenia (worm lizards) are clades deep within the Squamata (the smallest clade that contains all the lizards), so "lizard" is paraphyletic. The cladogram is based on genomic analysis by Wiens and colleagues in 2012 and 2016. Excluded taxa are shown in upper case on the cladogram. Taxonomy In the 13th century, lizards were recognized in Europe as part of a broad category of reptiles that consisted of a miscellany of egg-laying creatures, including "snakes, various fantastic monsters, […], assorted amphibians, and worms", as recorded by Vincent of Beauvais in his Mirror of Nature. The seventeenth century saw changes in this loose description. The name Sauria was coined by James Macartney (1802); it was the Latinisation of the French name Sauriens, coined by Alexandre Brongniart (1800) for an order of reptiles in the classification proposed by the author, containing lizards and crocodilians, later discovered not to be each other's closest relatives. Later authors used the term "Sauria" in a more restricted sense, i.e. as a synonym of Lacertilia, a suborder of Squamata that includes all lizards but excludes snakes. This classification is rarely used today because Sauria so-defined is a paraphyletic group. It was defined as a clade by Jacques Gauthier, Arnold G. Kluge and Timothy Rowe (1988) as the group containing the most recent common ancestor of archosaurs and lepidosaurs (the groups containing crocodiles and lizards, as per Mcartney's original definition) and all its descendants. A different definition was formulated by Michael deBraga and Olivier Rieppel (1997), who defined Sauria as the clade containing the most recent common ancestor of Choristodera, Archosauromorpha, Lepidosauromorpha and all their descendants. However, these uses have not gained wide acceptance among specialists. Suborder Lacertilia (Sauria) – (lizards) Family †Bavarisauridae Family †Eichstaettisauridae Infraorder Iguania Family †Arretosauridae Family †Euposauridae Family Corytophanidae (casquehead lizards) Family Iguanidae (iguanas and spinytail iguanas) Family Phrynosomatidae (earless, spiny, tree, side-blotched and horned lizards) Family Polychrotidae (anoles) Family Leiosauridae (see Polychrotinae) Family Tropiduridae (neotropical ground lizards) Family Liolaemidae (see Tropidurinae) Family Leiocephalidae (see Tropidurinae) Family Crotaphytidae (collared and leopard lizards) Family Opluridae (Madagascar iguanids) Family Hoplocercidae (wood lizards, clubtails) Family †Priscagamidae Family †Isodontosauridae Family Agamidae (agamas, frilled lizards) Family Chamaeleonidae (chameleons) Infraorder Gekkota Family Gekkonidae (geckos) Family Pygopodidae (legless geckos) Family Dibamidae (blind lizards) Infraorder Scincomorpha Family †Paramacellodidae Family †Slavoiidae Family Scincidae (skinks) Family Cordylidae (spinytail lizards) Family Gerrhosauridae (plated lizards) Family Xantusiidae (night lizards) Family Lacertidae (wall lizards or true lizards) Family †Mongolochamopidae Family †Adamisauridae Family Teiidae (tegus and whiptails) Family Gymnophthalmidae (spectacled lizards) Infraorder Diploglossa Family Anguidae (slowworms, glass lizards) Family Anniellidae (American legless lizards) Family Xenosauridae (knob-scaled lizards) Infraorder Platynota (Varanoidea) Family Varanidae (monitor lizards) Family Lanthanotidae (earless monitor lizards) Family Helodermatidae (Gila monsters and beaded lizards) Family †Mosasauridae (marine lizards) Convergence Lizards have frequently evolved convergently, with multiple groups independently developing similar morphology and ecological niches. Anolis ecomorphs have become a model system in evolutionary biology for studying convergence. Limbs have been lost or reduced independently over two dozen times across lizard evolution, including in the Anniellidae, Anguidae, Cordylidae, Dibamidae, Gymnophthalmidae, Pygopodidae, and Scincidae; snakes are just the most famous and species-rich group of Squamata to have followed this path. Relationship with humans Most lizard species are harmless to humans. Only the largest lizard species, the Komodo dragon, which reaches in length and weighs up to , has been known to stalk, attack, and, on occasion, kill humans. An eight-year-old Indonesian boy died from blood loss after an attack in 2007. Numerous species of lizard are kept as pets, including bearded dragons, iguanas, anoles, and geckos (such as the popular leopard gecko).Monitor lizards such as the savannah monitor and tegus such as the Argentine tegu and red tegu are also kept. Lizards appear in myths and folktales around the world. In Australian Aboriginal mythology, Tarrotarro, the lizard god, split the human race into male and female, and gave people the ability to express themselves in art. A lizard king named Mo'o features in Hawaii and other cultures in Polynesia. In the Amazon, the lizard is the king of beasts, while among the Bantu of Africa, the god UNkulunkulu sent a chameleon to tell humans they would live forever, but the chameleon was held up, and another lizard brought a different message, that the time of humanity was limited. A popular legend in Maharashtra tells the tale of how a common Indian monitor, with ropes attached, was used to scale the walls of the fort in the Battle of Sinhagad. In the Bhojpuri speaking region of India and Nepal, there is a belief among children that, on touching skink's tail three (or five) time with the shortest finger gives money. Green iguanas are eaten in Central America, where they are sometimes referred to as "chicken of the tree" after their habit of resting in trees and their supposedly chicken-like taste, while spiny-tailed lizards are eaten in Africa. In North Africa, Uromastyx species are considered dhaab or 'fish of the desert' and eaten by nomadic tribes. Lizards such as the Gila monster produce toxins with medical applications. Gila toxin reduces plasma glucose; the substance is now synthesized for use in the anti-diabetes drug exenatide (Byetta). Another toxin from Gila monster saliva has been studied for use as an anti-Alzheimer's drug. Lizards in many cultures share the symbolism of snakes, especially as an emblem of resurrection. This may have derived from their regular molting. The motif of lizards on Christian candle holders probably alludes to the same symbolism. According to Jack Tresidder, in Egypt and the Classical world they were beneficial emblems, linked with wisdom. In African, Aboriginal and Melanesian folklore they are linked to cultural heroes or ancestral figures. Notes References General sources Further reading External links Paraphyletic groups Obsolete vertebrate taxa Extant Hettangian first appearances	[ 0.3944586217403412, 0.3499670624732971, -0.8021815419197083, 0.2648921608924866, -0.37574899196624756, 0.7228901982307434, 0.9145382046699524, 0.540178656578064, -0.5472991466522217, 0.08213645219802856, -0.034158702939748764, 0.1293676346540451, -0.37573638558387756, -0.010774615220725536...
18185	https://en.wikipedia.org/wiki/List%20of%20deists	List of deists	This is a partial list of people who have been categorized as Deists, the belief in a deity based on natural religion only, or belief in religious truths discovered by people through a process of reasoning, independent of any revelation through scriptures or prophets. They have been selected for their influence on Deism, or for their fame in other areas. Ethan Allen (1738–89), early American revolutionary and guerrilla leader Al-Maʿarri (973–1058), was a blind Arab philosopher, poet and writer, and a controversial rationalist. Luis Walter Alvarez (1911–1988), American experimental physicist and inventor, who spent nearly all of his long professional career on the faculty of the University of California, Berkeley. He was awarded the Nobel Prize in Physics in 1968, and took out over 40 patents, some of which led to commercial products. Anaxagoras (c. 500–428 BC), Pre-Socratic Greek philosopher. Neil Armstrong (1930–2012), American NASA astronaut, test pilot, aerospace engineer, university professor, United States Naval Aviator, and the first person to set foot upon the Moon. Ludwig Boltzmann (1844–1906), Austrian physicist famous for his founding contributions in the fields of statistical mechanics and statistical thermodynamics. Max Born (1882–1970), German-British physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s. Born won the 1954 Nobel Prize in Physics (shared with Walther Bothe). Nick Cave (1957–), Australian musician, songwriter, poet, author and actor. Émilie du Châtelet (1706–1749), French mathematician, physicist, and author during the Age of Enlightenment. Her crowning achievement is considered to be her translation and commentary on Isaac Newton's work Principia Mathematica. Jean le Rond d'Alembert (1717–1783), French mathematician, mechanician, physicist, philosopher, and music theorist. He was also co-editor with Denis Diderot of the Encyclopédie. Leonardo da Vinci (1452–1519), Italian Renaissance polymath: painter, sculptor, architect, musician, scientist, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist, and writer. described as a deist by some sources. most historians have deemed him a Roman Catholic. Paul Davies (1946–), British physicist and science writer and broadcaster Humphry Davy (1778–1829), British chemist and inventor. Rodrigo Duterte (1945–), 16th President of the Philippines. Thomas Alva Edison (1847–1931), American inventor and businessman. Antony Flew (1923–2010), British analytic philosopher and prominent former atheist; during his last years he openly made an allegiance to Deism and stated to have acknowledged the existence of an Intelligent Creator of the universe, the Aristotelian God. Benjamin Franklin (1706–1790), American polymath; one of the Founding Fathers of the United States Martin Gardner (1914–2010), American popular mathematics and science writer specializing in recreational mathematics, but with interests encompassing micromagic, stage magic, literature (especially the writings of Lewis Carroll and G. K. Chesterton), philosophy, scientific skepticism, and religion. William Lloyd Garrison (1805–1879), American abolitionist, journalist, and social reformer. He is best known as the editor of the abolitionist newspaper The Liberator, and was one of the founders of the American Anti-Slavery Society, he promoted "immediate emancipation" of slaves in the United States. Carl Friedrich Gauss (1777–1855), German mathematician and physical scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics. Brett Gurewitz (1962–), guitarist and songwriter for the American punk rock band Bad Religion Edward Herbert, 1st Baron Herbert of Cherbury (1583–1648), British soldier, diplomat, historian, poet and religious philosopher Harish-Chandra (1923–1983), Indian mathematician, who did fundamental work in representation theory, especially Harmonic analysis on semisimple Lie groups. James Heckman (1944–), American economist who shared the Nobel Memorial Prize in Economic Sciences in 2000 for his pioneering work in econometrics and microeconomics. Victor Hugo (1802–85), French writer, artist, activist and statesman William Hogarth (1697–1764), English painter, visual artist and pioneering cartoonist James Hutton (1726–1797), Scottish physician, geologist, naturalist, chemical manufacturer and experimental agriculturalist. His work helped to establish the basis of modern geology. His theories of geology and geologic time, also called deep time, came to be included in theories which were called plutonism and uniformitarianism. Thomas Jefferson (1743–1826), author of the Jefferson Bible, an American Founding Father, the principal author of the U.S. Declaration of Independence, and the third President of the United States. Walter Kohn (1923–2016), Austrian-born American theoretical physicist. He was awarded, with John Pople, the Nobel Prize in Chemistry in 1998. Harmony Korine (1973–), American film director, producer, screenwriter, and author. Jean-Baptiste Lamarck (1744–1829), French naturalist. He was a soldier, biologist, academic, and an early proponent of the idea that evolution occurred and proceeded in accordance with natural laws. Abraham Lincoln (1809–1865), sixteenth president of the United States of America. He never joined any church and has been described as a "Christian deist". As a young man, he was religiously skeptical and sometimes ridiculed revivalists. During his early years, Lincoln enjoyed reading the works of deists such as Thomas Paine and Voltaire. He drafted a pamphlet incorporating such ideas but did not publish it. After charges of hostility to Christianity almost cost him a congressional bid, he kept his unorthodox beliefs private. James Adams labelled Lincoln as a deist. In 1834, he reportedly wrote a manuscript essay challenging Christianity modelled on Paine's book The Age of Reason, which a friend supposedly burned to protect him from ridicule. He seemed to believe in an all-powerful God, who shaped events and, by 1865, was expressing those beliefs in major speeches. Gottfried Leibniz (1646–1716), German mathematician and philosopher. He is best known for developing infinitesimal calculus independently of Isaac Newton, and his mathematical notation has been widely used ever since it was published. He has also been labeled a Christian as well. Gotthold Ephraim Lessing (1729–1781), German writer, philosopher, dramatist, publicist, and art critic Mikhail Lomonosov (1711–1765), Russian polymath, scientist and writer, who made important contributions to literature, education, and science. Among his discoveries was the atmosphere of Venus. His spheres of science were natural science, chemistry, physics, mineralogy, history, art, philology, optical devices and others. Lomonosov was also a poet and influenced the formation of the modern Russian literary language. Charles Lyell (1797–1875), British lawyer and the foremost geologist of his day. He is best known as the author of Principles of Geology, which popularised James Hutton's concepts of uniformitarianism. Colin Maclaurin (1698–1746), Scottish mathematician who made important contributions to geometry and algebra. The Maclaurin series, a special case of the Taylor series, are named after him. James Madison (1751–1836), "Father of the United States Constitution", one of the Founding Fathers of the United States, and the 4th President of the United States Alfred M. Mayer (1836–1897), American physicist. Dmitri Mendeleev (1834–1907), Russian chemist and inventor. He is credited as being the creator of the first version of the periodic table of elements. Moses Mendelssohn (1729–1796), German philosopher influential in the Jewish Haskalah Simon Newcomb (1835–1909), Canadian-American astronomer and mathematician. Thomas Paine (1737–1809), English pamphleteer, revolutionary, radical, inventor, and intellectual, and one of the Founding Fathers of the United States Elihu Palmer (1764–1806), American author and advocate of deism Wolfgang Pauli (1900–1958), Austrian theoretical physicist. In 1945, he received the Nobel Prize in Physics. He is best known for his work on Pauli principle and spin theory. Charles Sanders Peirce (1839–1914), American philosopher, logician, mathematician, and scientist, sometimes known as "the father of pragmatism". He was educated as a chemist and employed as a scientist for 30 years. Today he is appreciated largely for his contributions to logic, mathematics, philosophy, scientific methodology, and semiotics, and for his founding of pragmatism. Max Planck (1858–1947), German physicist, regarded as the founder of quantum theory. José Rizal (1861–1896), a Filipino patriot, philosopher, medical doctor, poet, journalist, novelist, political scientist, painter and polyglot. Considered to be one of the Philippines' most important heroes and martyrs whose writings and execution contributed to the igniting of the Philippine Revolution. He is also considered as Asia's first modern non-violent proponent of freedom. Ernest Rutherford (1871–1937), New Zealand chemist and "father" of nuclear physics, who was awarded the Nobel Prize in Chemistry in 1908 "for his investigations into the disintegration of the elements, and the chemistry of radioactive substances". Maximilien Robespierre (1758–94), French revolutionary and lawyer Friedrich Schiller (1759–1805), German poet, philosopher, historian, and playwright. Adam Smith (1723–1790), Scottish Philosopher and economist; considered the father of modern economics Lysander Spooner (1808–1887), American anarchist, philosopher and abolitionist Matthew Tindal (1657–1733), controversial English author whose works were influential on Enlightenment thinking Mark Twain (1835–1910), American author and humorist Jules Verne (1828–1905), French author who pioneered the science fiction genre in Europe. He is best known for his novels Twenty Thousand Leagues Under the Sea, Journey to the Center of the Earth, and Around the World in Eighty Days. Voltaire (1694–1778), French Enlightenment writer and philosopher George Washington (1732–1799), American soldier, statesman, and Founding Father, who served as the first president of the United States from 1789 to 1797. James Watt (1736–1819), Scottish inventor and mechanical engineer whose improvements to the Newcomen steam engine were fundamental to the changes brought by the Industrial Revolution in both his native Great Britain and the rest of the world. Johann Adam Weishaupt (1748–1830), Bavarian Philosopher, Canon Law Professor and Founder of the Illuminati Henrik Wergeland (1808–1845), Norwegian poet and theologist (by self-definition). Hermann Weyl (1885–1955), German mathematician and theoretical physicist. See also List of people by belief References Deists	[ 0.6438935995101929, 0.5676926374435425, -0.767631471157074, -0.07646661251783371, -0.5034807324409485, 0.16273526847362518, 1.0428494215011597, 0.5237902402877808, -0.209245964884758, -0.13220176100730896, -0.15597859025001526, 0.5053925514221191, -0.25695785880088806, 0.37548261880874634,...
18187	https://en.wikipedia.org/wiki/Book%20of%20Leviticus	Book of Leviticus	The Book of Leviticus (, from Leuïtikón; Vayyīqrāʾ, "And He called") is the third book of the Torah (the Pentateuch) and of the Old Testament, also known as the Third Book of Moses; scholars generally agree that it developed over a long period of time, reaching its present form during the Persian Period between 538–332 BC. Most of its chapters (1–7, 11–27) consist of Yahweh's speeches to Moses, which Yahweh commands Moses to repeat to the Israelites. This takes place within the story of the Israelites' Exodus after they escaped Egypt and reached Mount Sinai (Exodus 19:1). The Book of Exodus narrates how Moses led the Israelites in building the Tabernacle (Exodus 35–40) with God's instructions (Exodus 25–31). In Leviticus, God tells the Israelites and their priests, the Levites, how to make offerings in the Tabernacle and how to conduct themselves while camped around the holy tent sanctuary. Leviticus takes place during the month or month-and-a-half between the completion of the Tabernacle (Exodus 40:17) and the Israelites' departure from Sinai (Numbers 1:1, 10:11). The instructions of Leviticus emphasize ritual, legal and moral practices rather than beliefs. Nevertheless, they reflect the world view of the creation story in Genesis 1 that God wishes to live with humans. The book teaches that faithful performance of the sanctuary rituals can make that possible, so long as the people avoid sin and impurity whenever possible. The rituals, especially the sin and guilt offerings, provide the means to gain forgiveness for sins (Leviticus 4–5) and purification from impurities (Leviticus 11–16) so that God can continue to live in the Tabernacle in the midst of the people. Name The English name Leviticus comes from the Latin Leviticus, which is in turn from the , Leuitikon, referring to the priestly tribe of the Israelites, "Levi". The Greek expression is in turn a variant of the rabbinic Hebrew torat kohanim, "law of priests", as many of its laws relate to priests. In Hebrew the book is called Vayikra (), from the opening of the book, va-yikra "And He [God] called." Structure The outlines from commentaries are similar, though not identical; compare those of Wenham, Hartley, Milgrom, and Watts. I. Laws on sacrifice (1:1–7:38) A. Instructions for the laity on bringing offerings (1:1–6:7) 1–5. The types of offering: burnt, cereal, peace, purification, reparation (or sin) offerings (ch. 1–5) B. Instructions for the priests (6:1–7:38) 1–6. The various offerings, with the addition of the priests' cereal offering (6:1–7:36) 7. Summary (7:37–38) II. Institution of the priesthood (8:1–10:20) A. Ordination of Aaron and his sons (ch. 8) B. Aaron makes the first sacrifices (ch. 9) C. Judgement on Nadab and Abihu (ch. 10) III. Uncleanliness and its treatment (11:1–15:33) A. Unclean animals (ch. 11) B. Childbirth as a source of uncleanliness (ch. 12) C. Unclean diseases (ch. 13) D. Cleansing of diseases (ch. 14) E. Unclean discharges (ch. 15) IV. Day of Atonement: purification of the tabernacle from the effects of uncleanliness and sin (ch. 16) V. Prescriptions for practical holiness (the Holiness Code, chs. 17–26) A. Sacrifice and food (ch. 17) B. Sexual behaviour (ch. 18) C. Neighbourliness (ch.19) D. Grave crimes (ch. 20) E. Rules for priests (ch. 21) F. Rules for eating sacrifices (ch. 22) G. Festivals (ch.23) H. Rules for the tabernacle (ch. 24:1–9) I. Blasphemy (ch. 24:10–23) J. Sabbatical and Jubilee years (ch. 25) K. Exhortation to obey the law: blessing and curse (ch. 26) VI. Redemption of votive gifts (ch. 27) Summary Chapters 1–5 describe the various sacrifices from the sacrificers' point of view, although the priests are essential for handling the blood. Chapters 6–7 go over much the same ground, but from the point of view of the priest, who, as the one actually carrying out the sacrifice and dividing the "portions", needs to know how to do it. Sacrifices are between God, the priest, and the offerers, although in some cases the entire sacrifice is a single portion to God—i.e., burnt to ashes. Chapters 8–10 describe how Moses consecrates Aaron and his sons as the first priests, the first sacrifices, and God's destruction of two of Aaron's sons for ritual offenses. The purpose is to underline the character of altar priesthood (i.e., those priests with power to offer sacrifices to God) as an Aaronite privilege, and the responsibilities and dangers of their position. With sacrifice and priesthood established, chapters 11–15 instruct the lay people on purity (or cleanliness). Eating certain animals produces uncleanliness, as does giving birth; certain skin diseases (but not all) are unclean, as are certain conditions affecting walls and clothing (mildew and similar conditions); and genital discharges, including female menses and male gonorrhea, are unclean. The reasoning behind the food rules are obscure; for the rest the guiding principle seems to be that all these conditions involve a loss of "life force", usually but not always blood. Leviticus 16 concerns the Day of Atonement. This is the only day on which the High Priest is to enter the holiest part of the sanctuary, the holy of holies. He is to sacrifice a bull for the sins of the priests, and a goat for the sins of the laypeople. The priest is to send a second goat into the desert to "Azazel", bearing the sins of the whole people. Azazel may be a wilderness-demon, but its identity is mysterious. Chapters 17–26 are the Holiness code. It begins with a prohibition on all slaughter of animals outside the Temple, even for food, and then prohibits a long list of sexual contacts and also child sacrifice. The "holiness" injunctions which give the code its name begin with the next section: there are penalties for the worship of Molech, consulting mediums and wizards, cursing one's parents and engaging in unlawful sex. Priests receive instruction on mourning rituals and acceptable bodily defects. The punishment for blasphemy is death, and there is the setting of rules for eating sacrifices; there is an explanation of the calendar, and there are rules for sabbatical and Jubilee years; there are rules for oil lamps and bread in the sanctuary; and there are rules for slavery. The code ends by telling the Israelites they must choose between the law and prosperity on the one hand, or, on the other, horrible punishments, the worst of which will be expulsion from the land. Chapter 27 is a disparate and probably late addition telling about persons and things serving as dedication to the Lord and how one can redeem, instead of fulfill, vows. Composition The majority of scholars have concluded that the Pentateuch received its final form during the Persian period (538–332 BC). Nevertheless, Leviticus had a long period of growth before reaching that form. The entire composition of the book of Leviticus is Priestly literature. Most scholars see chapters 1–16 (the Priestly code) and chapters 17–26 (the Holiness code) as the work of two related schools, but while the Holiness material employs the same technical terms as the Priestly code, it broadens their meaning from pure ritual to the theological and moral, turning the ritual of the Priestly code into a model for the relationship of Israel to Yahweh: as the tabernacle, which is apart from uncleanliness, becomes holy by the presence of Yahweh, so He will dwell among Israel when Israel receives purification (becomes holy) and separates from other peoples. The ritual instructions in the Priestly code apparently grew from priests giving instruction and answering questions about ritual matters; the Holiness code (or H) used to be a separate document, later becoming part of Leviticus, but it seems better to think of the Holiness authors as editors who worked with the Priestly code and actually produced Leviticus as we now have it. Themes Sacrifice and ritual Many scholars argue that the rituals of Leviticus have a theological meaning concerning Israel's relationship with its God. Jacob Milgrom was especially influential in spreading this view. He maintained that the priestly regulations in Leviticus expressed a rational system of theological thought. The writers expected them to be put into practice in Israel's temple, so the rituals would express this theology as well, as well as ethical concern for the poor. Milgrom also argued that the book's purity regulations (chaps. 11–15) have a basis in ethical thinking. Many other interpreters have followed Milgrom in exploring the theological and ethical implications of Leviticus's regulations (e.g. Marx, Balentine), though some have questioned how systematic they really are. Ritual, therefore, is not taking a series of actions for their own sake, but a means of maintaining the relationship between God, the world, and humankind. Kehuna (Jewish priesthood) The main function of the priests is service at the altar, and only the sons of Aaron are priests in the full sense. (Ezekiel also distinguishes between altar-priests and lower Levites, but in Ezekiel the altar-priests are sons of Zadok instead of sons of Aaron; many scholars see this as a remnant of struggles between different priestly factions in First Temple times, finding resolution by the Second Temple into a hierarchy of Aaronite altar-priests and lower-level Levites, including singers, gatekeepers and the like). In chapter 10, God kills Nadab and Abihu, the oldest sons of Aaron, for offering "strange incense". Aaron has two sons left. Commentators have read various messages in the incident: a reflection of struggles between priestly factions in the post–Exilic period (Gerstenberger); or a warning against offering incense outside the Temple, where there might be the risk of invoking strange gods (Milgrom). In any case, there has been a pollution of the sanctuary by the bodies of the two dead priests, leading into the next theme, holiness. Uncleanliness and purity Ritual purity is essential for an Israelite to be able to approach Yahweh and remain part of the community. Uncleanliness threatens holiness; Chapters 11–15 review the various causes of uncleanliness and describe the rituals which will restore cleanliness; one is to maintain cleanliness through observation of the rules on sexual behaviour, family relations, land ownership, worship, sacrifice, and observance of holy days. Yahweh dwells with Israel in the holy of holies. All of the priestly ritual focuses on Yahweh and the construction and maintenance of a holy space, but sin generates impurity, as do everyday events such as childbirth and menstruation; impurity pollutes the holy dwelling place. Failure to ritually purify the sacred space could result in God leaving, which would be disastrous. Infectious diseases in Chapter 13 In Leviticus 13, the Lord God told Moses and Aaron how to identify infectious diseases and deal with them accordingly. The translators and interpreters of the Bible in various languages have never reached a consensus on these infectious diseases or tzaraath (Hebrew צרעת), so that the translation and interpretation of the scriptures are not known for certain. The most translated disease is leprosy, but what is described in the scriptures is not a typical manifestation of leprosy as we know it today. In fact, any modern dermatologist can tell that these are mainly dermatophytoses, which are a group of highly contagious skin diseases. Firstly, the infectious disease of the chin described in Verses 29-37 seems to be Tinea barbae in men or Tinea faciei in women; and, the infectious disease described in Verses 29-37 with hair loss and eventual baldness seems to be Tinea capitis (Favus). Verses 1-17 seem to describe Tinea corporis. The Hebrew word bohaq, alphos in Verses 38-39 is translated as tetter or freckles, likely because translators did not know what it meant at the time, and thus, translated it incorrectly. Later translations believe it is talking about vitiligo, however, vitiligo is not an infectious disease. We can conclude the only infectious disease that can heal itself and leave white patches after infection is pityriasis versicolor (tinea versicolor). Tetter originally meant an outbreak, which later evolved meaning ringworm-like lesions. Therefore, a common name for Tinea pedis (athlete's foot) was Cantlie’s foot tetter. In addition, Verses 18-23 describe infections after scald, and Verses 24-28 describe infections after burn. These two infections are translated into diseases that are unknown in the Chinese version. Atonement Through sacrifice, the priest "makes atonement" for sin and the offeror receives forgiveness (but only if Yahweh accepts the sacrifice). Atonement rituals involve the pouring or sprinkling of blood as the symbol of the life of the victim: the blood has the power to wipe out or absorb the sin. The two-part division of the book structurally reflects the role of atonement: chapters 1–16 call for the establishment of the institution for atonement, and chapters 17–27 call for the life of the atoned community in holiness. Holiness The consistent theme of chapters 17–26 is in the repetition of the phrase, "Be holy, for I the Lord your God am holy." Holiness in ancient Israel and the Bible had a different meaning than in contemporary usage: it might have been regarded as the essence of Yahweh, an invisible but physical and potentially dangerous force. Specific objects, or even days, can be holy, but they derive holiness from being connected with Yahweh—the seventh day, the tabernacle, and the priests all derive their holiness from Him. As a result, Israel had to maintain its own holiness in order to live safely alongside God. The need for holiness is for the possession of the Promised Land (Canaan), where the Jews will become a holy people: "You shall not do as they do in the land of Egypt where you dwelt, and you shall not do as they do in the land of Canaan to which I am bringing you...You shall do my ordinances and keep my statutes...I am the Lord, your God." (Leviticus 18:3). Subsequent tradition Leviticus, as part of the Torah, became the law book of Jerusalem's Second Temple as well as of the Samaritan temple. Evidence of its influence is evident among the Dead Sea Scrolls, which included fragments of seventeen manuscripts of Leviticus dating from the third to the first centuries BC. Many other Qumran scrolls cite the book, especially the Temple Scroll and 4QMMT. Jews and Christians have not observed Leviticus's instructions for animal offerings since the first century AD. Because of the destruction of the temple in Jerusalem in 70 AD, Jewish worship has focused on prayer and the study of Torah. Nevertheless, Leviticus constitutes a major source of Jewish law and is traditionally the first book children learn in the Rabbinic system of education. There are two main Midrashim on Leviticus—the halakhic one (Sifra) and a more aggadic one (Vayikra Rabbah). The New Testament, particularly the Epistle to the Hebrews, uses ideas and images from Leviticus to describe Christ as the high priest who offers his own blood as a sin offering. Therefore, Christians do not make animal offerings, either, as Gordon Wenham summarized: "With the death of Christ the only sufficient 'burnt offering' was offered once and for all, and therefore the animal sacrifices which foreshadowed Christ's sacrifice were made obsolete." Christians generally have the view that the New Covenant supersedes the Old Testament's ritual laws, which includes many of the rules in Leviticus. Christians, therefore, do not usually follow Leviticus' rules regarding diet, purity, and agriculture. Christian teachings have differed, however, as to where to draw the line between ritual and moral regulations. In Homilies on Leviticus, Origen expounds on the qualities of priests: to be perfect in everything, strict, wise and to examine themselves individually, forgive sins, and convert sinners (by words and by doctrine). Judaism's weekly Torah portions in the Book of Leviticus For detailed contents, see: Vayikra, on Leviticus 1–5: Laws of the sacrifices Tzav, on Leviticus 6–8: Sacrifices, ordination of the priests Shemini, on Leviticus 9–11: Concecration of tabernacle, alien fire, dietary laws Tazria, on Leviticus 12–13: Childbirth, skin disease, clothing Metzora, on Leviticus 14–15: Skin disease, unclean houses, genital discharges Acharei Mot, on Leviticus 16–18: Yom Kippur, centralized offerings, sexual practices Kedoshim, on Leviticus 19–20: Holiness, penalties for transgressions Emor, on Leviticus 21–24: Rules for priests, holy days, lights and bread, a blasphemer Behar, on Leviticus 25–25: Sabbatical year, debt servitude limited Bechukotai, on Leviticus 26–27: Blessings and curses, payment of vows See also 613 commandments En-Gedi Scroll Paleo-Hebrew Leviticus scroll Liberty Bell – inscribed with a quotation from Leviticus References Bibliography Translations of Leviticus Leviticus at Bible gateway Commentaries on Leviticus Bamberger, Bernard Jacob The Torah: A Modern Commentary (1981), General External links Online versions of Leviticus: Hebrew: Leviticus at Mechon-Mamre (Jewish Publication Society translation) Leviticus (The Living Torah) Rabbi Aryeh Kaplan's translation and commentary at Ort.org Vayikra—Levitichius (Judaica Press) translation [with Rashi's commentary] at Chabad.org ויקרא Vayikra—Leviticus (Hebrew—English at Mechon-Mamre.org) Christian translations: The Book of Leviticus, Douay Rheims Version, with Bishop Challoner Commentaries Online Bible at GospelHall.org (King James Version) Online Audio and Classic Bible at Bible-Book.org (King James Version) oremus Bible Browser (New Revised Standard Version) oremus Bible Browser (Anglicized New Revised Standard Version) Various versions Related article: Book of Leviticus article (Jewish Encyclopedia) The Literary Structure of Leviticus (chaver.com) Brief introduction Leviticus 7th-century BC books 6th-century BC books 5th-century BC books 4th-century BC books Tabernacle and Temples in Jerusalem 3	[ 0.31428536772727966, 0.334318608045578, -0.5337182283401489, -0.7486415505409241, -0.38917016983032227, 0.5821288824081421, 0.40868061780929565, -0.03962066024541855, 0.049014635384082794, -0.44468945264816284, -0.22249595820903778, -0.08372915536165237, -0.3337181806564331, -0.03285009413...
18188	https://en.wikipedia.org/wiki/L.%20Frank%20Baum	L. Frank Baum	Lyman Frank Baum (; May 15, 1856 – May 6, 1919) was an American author best known for his children's books, particularly The Wonderful Wizard of Oz and its sequels. He wrote 14 novels in the Oz series, plus 41 other novels (not including four lost, unpublished novels), 83 short stories, over 200 poems, and at least 42 scripts. He made numerous attempts to bring his works to the stage and screen; the 1939 adaptation of the first Oz book became a landmark of 20th-century cinema. Born and raised in upstate New York, Baum moved west after an unsuccessful stint as a theater producer and playwright. He and his wife opened a store in South Dakota and he edited and published a newspaper. They then moved to Chicago, where he worked as a newspaper reporter and published children's literature, coming out with the first Oz book in 1900. While continuing his writing, among his final projects he sought to establish a movie studio focused on children's films in Los Angeles, California. His works anticipated such later commonplaces as television, augmented reality, laptop computers (The Master Key), wireless telephones (Tik-Tok of Oz), women in high-risk and action-heavy occupations (Mary Louise in the Country), and the ubiquity of clothes advertising (Aunt Jane's Nieces at Work). Childhood and early life Baum was born in Chittenango, New York, in 1856 into a devout Methodist family. He had German, Scots-Irish, and English ancestry. He was the seventh of nine children of Cynthia Ann (née Stanton) and Benjamin Ward Baum, only five of whom survived into adulthood. "Lyman" was the name of his father's brother, but he always disliked it and preferred his middle name "Frank". His father succeeded in many businesses, including barrel-making, oil drilling in Pennsylvania, and real estate. Baum grew up on his parents' expansive estate called Rose Lawn, which he fondly recalled as a sort of paradise. Rose Lawn was located in Mattydale, New York. Frank was a sickly, dreamy child, tutored at home with his siblings. From the age of 12, he spent two miserable years at Peekskill Military Academy but, after being severely disciplined for daydreaming, he had a possibly psychogenic heart attack and was allowed to return home. Baum started writing early in life, possibly prompted by his father buying him a cheap printing press. He had always been close to his younger brother Henry (Harry) Clay Baum, who helped in the production of The Rose Lawn Home Journal. The brothers published several issues of the journal, including advertisements from local businesses, which they gave to family and friends for free. By the age of 17, Baum established a second amateur journal called The Stamp Collector, printed an 11-page pamphlet called Baum's Complete Stamp Dealers' Directory, and started a stamp dealership with friends. At 20, Baum took on the national craze of breeding fancy poultry. He specialized in raising the Hamburg chicken. In March 1880, he established a monthly trade journal, The Poultry Record, and in 1886, when Baum was 30 years old, his first book was published: The Book of the Hamburgs: A Brief Treatise upon the Mating, Rearing, and Management of the Different Varieties of Hamburgs. Baum had a flair for being the spotlight of fun in the household, including during times of financial difficulties. His selling of fireworks made the Fourth of July memorable. His skyrockets, Roman candles, and fireworks filled the sky, while many people around the neighborhood would gather in front of the house to watch the displays. Christmas was even more festive. Baum dressed as Santa Claus for the family. His father would place the Christmas tree behind a curtain in the front parlor so that Baum could talk to everyone while he decorated the tree without people managing to see him. He maintained this tradition all his life. Career Theater Baum embarked on his lifetime infatuation—and wavering financial success—with the theater. A local theatrical company duped him into replenishing their stock of costumes on the promise of leading roles coming his way. Disillusioned, Baum left the theater—temporarily—and went to work as a clerk in his brother-in-law's dry goods company in Syracuse. This experience may have influenced his story "The Suicide of Kiaros", first published in the literary journal The White Elephant. A fellow clerk one day had been found locked in a store room dead, probably from suicide. Baum could never stay away long from the stage. He performed in plays under the stage names of Louis F. Baum and George Brooks. In 1880, his father built him a theater in Richburg, New York, and Baum set about writing plays and gathering a company to act in them. The Maid of Arran proved a modest success, a melodrama with songs based on William Black's novel A Princess of Thule. Baum wrote the play and composed songs for it (making it a prototypical musical, as its songs relate to the narrative), and acted in the leading role. His aunt Katharine Gray played his character's aunt. She was the founder of Syracuse Oratory School, and Baum advertised his services in her catalog to teach theater, including stage business, play writing, directing, translating (French, German, and Italian), revision, and operettas. On November 9, 1882, Baum married Maud Gage, a daughter of Matilda Joslyn Gage, a famous women's suffrage and feminist activist. While Baum was touring with The Maid of Arran, the theater in Richburg caught fire during a production of Baum's ironically titled parlor drama Matches, destroying the theater as well as the only known copies of many of Baum's scripts, including Matches, as well as costumes. The South Dakota years In July 1888, Baum and his wife moved to Aberdeen, Dakota Territory where he opened a store called "Baum's Bazaar". His habit of giving out wares on credit led to the eventual bankrupting of the store, so Baum turned to editing the local newspaper The Aberdeen Saturday Pioneer where he wrote the column Our Landlady. Following the death of Sitting Bull at the hands of Indian agency police, Baum urged the wholesale extermination of all America's native peoples in a column that he wrote on December 20, 1890 (full text below). On January 3, 1891, he returned to the subject in an editorial response to the Wounded Knee Massacre: The Pioneer has before declared that our only safety depends upon the total extirmination of the Indians. Having wronged them for centuries, we had better, in order to protect our civilization, follow it up by one more wrong and wipe these untamed and untamable creatures from the face of the earth. Baum's description of Kansas in The Wonderful Wizard of Oz is based on his experiences in drought-ridden South Dakota. During much of this time, Matilda Joslyn Gage was living in the Baum household. While Baum was in South Dakota, he sang in a quartet which included James Kyle, who became one of the first Populist (People's Party) Senators in the U.S. Writing Baum's newspaper failed in 1891, and he, Maud, and their four sons moved to the Humboldt Park section of Chicago, where Baum took a job reporting for the Evening Post. Beginning in 1897, he founded and edited a magazine called The Show Window, later known as the Merchants Record and Show Window, which focused on store window displays, retail strategies and visual merchandising. The major department stores of the time created elaborate Christmas time fantasies, using clockwork mechanisms that made people and animals appear to move. The former Show Window magazine is still currently in operation, now known as VMSD magazine (visual merchandising + store design), based in Cincinnati. In 1900, Baum published a book about window displays in which he stressed the importance of mannequins in drawing customers. He also had to work as a traveling salesman. In 1897, he wrote and published Mother Goose in Prose, a collection of Mother Goose rhymes written as prose stories and illustrated by Maxfield Parrish. Mother Goose was a moderate success and allowed Baum to quit his sales job (which had had a negative impact on his health). In 1899, Baum partnered with illustrator W. W. Denslow to publish Father Goose, His Book, a collection of nonsense poetry. The book was a success, becoming the best-selling children's book of the year. The Wonderful Wizard of Oz In 1900, Baum and Denslow (with whom he shared the copyright) published The Wonderful Wizard of Oz to much critical acclaim and financial success. The book was the best-selling children's book for two years after its initial publication. Baum went on to write thirteen more novels based on the places and people of the Land of Oz. The Wizard of Oz: Fred R. Hamlin's Musical Extravaganza Two years after Wizard publication, Baum and Denslow teamed up with composer Paul Tietjens and director Julian Mitchell to produce a musical stage version of the book under Fred R. Hamlin. Baum and Tietjens had worked on a musical of The Wonderful Wizard of Oz in 1901 and based closely upon the book, but it was rejected. This stage version opened in Chicago in 1902 (the first to use the shortened title "The Wizard of Oz"), then ran on Broadway for 293 stage nights from January to October 1903. It returned to Broadway in 1904, where it played from March to May and again from November to December. It successfully toured the United States with much of the same cast, as was done in those days, until 1911, and then became available for amateur use. The stage version starred Anna Laughlin as Dorothy Gale, alongside David C. Montgomery and Fred Stone as the Tin Woodman and Scarecrow respectively, which shot the pair to instant fame. The stage version differed quite a bit from the book, and was aimed primarily at adults. Toto was replaced with Imogene the Cow, and Tryxie Tryfle (a waitress) and Pastoria (a streetcar operator) were added as fellow cyclone victims. The Wicked Witch of the West was eliminated entirely in the script, and the plot became about how the four friends were allied with the usurping Wizard and were hunted as traitors to Pastoria II, the rightful King of Oz. It is unclear how much control or influence Baum had on the script; it appears that many of the changes were written by Baum against his wishes due to contractual requirements with Hamlin. Jokes in the script, mostly written by Glen MacDonough, called for explicit references to President Theodore Roosevelt, Senator Mark Hanna, Rev. Andrew Danquer, and oil tycoon John D. Rockefeller. Although use of the script was rather free-form, the line about Hanna was ordered dropped as soon as Hamlin got word of his death in 1904. Beginning with the success of the stage version, most subsequent versions of the story, including newer editions of the novel, have been titled "The Wizard of Oz", rather than using the full, original title. In more recent years, restoring the full title has become increasingly common, particularly to distinguish the novel from the Hollywood film. Baum wrote a new Oz book, The Marvelous Land of Oz, with a view to making it into a stage production, which was titled The Woggle-Bug, but Montgomery and Stone balked at appearing when the original was still running. The Scarecrow and Tin Woodman were then omitted from this adaptation, which was seen as a self-rip-off by critics and proved to be a major flop before it could reach Broadway. He also worked for years on a musical version of Ozma of Oz, which eventually became The Tik-Tok Man of Oz. This did fairly well in Los Angeles, but not well enough to convince producer Oliver Morosco to mount a production in New York. He also began a stage version of The Patchwork Girl of Oz, but this was ultimately realized as a film. Later life and work With the success of Wizard on page and stage, Baum and Denslow hoped for further success and published Dot and Tot of Merryland in 1901. The book was one of Baum's weakest, and its failure further strained his faltering relationship with Denslow. It was their last collaboration. Baum worked primarily with John R. Neill on his fantasy work beginning in 1904, but Baum met Neill few times (all before he moved to California) and often found Neill's art not humorous enough for his liking. He was particularly offended when Neill published The Oz Toy Book: Cut-outs for the Kiddies without authorization. Baum reportedly designed the chandeliers in the Crown Room of the Hotel del Coronado; however, that attribution has yet to be corroborated. Several times during the development of the Oz series, Baum declared that he had written his last Oz book and devoted himself to other works of fantasy fiction based in other magical lands, including The Life and Adventures of Santa Claus and Queen Zixi of Ix. However, he returned to the series each time, persuaded by popular demand, letters from children, and the failure of his new books. Even so, his other works remained very popular after his death, with The Master Key appearing on St. Nicholas Magazine's survey of readers' favorite books well into the 1920s. In 1905, Baum declared plans for an Oz amusement park. In an interview, he mentioned buying “Pedloe Island” off the coast of California to turn it into an Oz park. However, there is no evidence that he purchased such an island, and no one has ever been able to find any island whose name even resembles Pedloe in that area. Nevertheless, Baum stated to the press that he had discovered a Pedloe Island off the coast of California and that he had purchased it to be "the Marvelous Land of Oz," intending it to be "a fairy paradise for children." Eleven year old Dorothy Talbot of San Francisco was reported to be ascendant to the throne on March 1, 1906, when the Palace of Oz was expected to be completed. Baum planned to live on the island, with administrative duties handled by the princess and her all-child advisers. Plans included statues of the Scarecrow, Tin Woodman, Jack Pumpkinhead, and H.M. Woggle-Bug, T.E. Baum abandoned his Oz park project after the failure of The Woggle-Bug, which was playing at the Garrick Theatre in 1905. Because of his lifelong love of theatre, he financed elaborate musicals, often to his financial detriment. One of Baum's worst financial endeavors was his The Fairylogue and Radio-Plays (1908), which combined a slideshow, film, and live actors with a lecture by Baum as if he were giving a travelogue to Oz. However, Baum ran into trouble and could not pay his debts to the company who produced the films. He did not get back to a stable financial situation for several years, after he sold the royalty rights to many of his earlier works, including The Wonderful Wizard of Oz. This resulted in the M.A. Donahue Company publishing cheap editions of his early works with advertising which purported that Baum's newer output was inferior to the less expensive books that they were releasing. He claimed bankruptcy in August 1911. However, Baum had shrewdly transferred most of his property into Maud's name, except for his clothing, his typewriter, and his library (mostly of children's books, such as the fairy tales of Andrew Lang, whose portrait he kept in his study)—all of which, he successfully argued, were essential to his occupation. Maud handled the finances anyway, and thus Baum lost much less than he could have. Baum made use of several pseudonyms for some of his other non-Oz books. They include: Edith Van Dyne (the Aunt Jane's Nieces series) Laura Bancroft (The Twinkle Tales, Policeman Bluejay) Floyd Akers (The Boy Fortune Hunters series, continuing the Sam Steele series) Suzanne Metcalf (Annabel) Schuyler Staunton (The Fate of a Crown, Daughters of Destiny) John Estes Cooke (Tamawaca Folks) Capt. Hugh Fitzgerald (the Sam Steele series) Baum also anonymously wrote The Last Egyptian: A Romance of the Nile. He continued theatrical work with Harry Marston Haldeman's men's social group The Uplifters, for which he wrote several plays for various celebrations. He also wrote the group's parodic by-laws. The group also included Will Rogers, but was proud to have had Baum as a member and posthumously revived many of his works despite their ephemeral intent. Many of these play's titles are known, but only The Uplift of Lucifer is known to survive (it was published in a limited edition in the 1960s). Prior to that, his last produced play was The Tik-Tok Man of Oz (based on Ozma of Oz and the basis for Tik-Tok of Oz), a modest success in Hollywood that producer Oliver Morosco decided did not do well enough to take to Broadway. Morosco, incidentally, quickly turned to film production, as did Baum. In 1914, Baum started his own film production company The Oz Film Manufacturing Company, which came as an outgrowth of the Uplifters. He served as its president and principal producer and screenwriter. The rest of the board consisted of Louis F. Gottschalk, Harry Marston Haldeman, and Clarence R. Rundel. The films were directed by J. Farrell MacDonald, with casts that included Violet MacMillan, Vivian Reed, Mildred Harris, Juanita Hansen, Pierre Couderc, Mai Welles, Louise Emmons, J. Charles Haydon, and early appearances by Harold Lloyd and Hal Roach. Silent film actor Richard Rosson appeared in one of the films (Rosson's younger brother Harold Rosson was the cinematographer on The Wizard of Oz, released in 1939). After little success probing the unrealized children's film market, Baum acknowledged his authorship of The Last Egyptian and made a film of it (portions of which are included in Decasia), but the Oz name had become box office poison for the time being, and even a name change to Dramatic Feature Films and transfer of ownership to Frank Joslyn Baum did not help. Baum invested none of his own money in the venture, unlike The Fairylogue and Radio-Plays, but the stress probably took its toll on his health. Death On May 5, 1919, Baum suffered a stroke, slipped into a coma and died the following day, at the age of 62. His last words were spoken to his wife during a brief period of lucidity: "Now we can cross the Shifting Sands." He was buried in Glendale's Forest Lawn Memorial Park Cemetery. His final Oz book, Glinda of Oz, was published on July 10, 1920, a year after his death. The Oz series was continued long after his death by other authors, notably Ruth Plumly Thompson, who wrote an additional twenty-one Oz books. Baum's beliefs Literary Baum's avowed intentions with the Oz books and his other fairy tales was to retell tales such as those which are found in the works of the Brothers Grimm and Hans Christian Andersen, remake them in an American vein, update them, omit stereotypical characters such as dwarfs or genies, and remove the association of violence and moral teachings. His first Oz books contained a fair amount of violence, but the amount of it decreased as the series progressed; in The Emerald City of Oz, Ozma objects to the use of violence, even to the use of violence against the Nomes who threaten Oz with invasion. His introduction is often cited as the beginning of the sanitization of children's stories, although he did not do a great deal more than eliminate harsh moral lessons. Another traditional element that Baum intentionally omitted was the emphasis on romance. He considered romantic love to be uninteresting to young children, as well as largely incomprehensible. In The Wonderful Wizard of Oz, the only elements of romance lay in the background of the Tin Woodman and his love for Nimmie Amee, which explains his condition but does not affect the tale in any other way, and the background of Gayelette and the enchantment of the Winged monkeys. The only other stories with such elements were The Scarecrow of Oz and Tik-Tok of Oz, both of them were based on dramatizations, which Baum regarded warily until his readers accepted them. Political Women's suffrage advocate When Baum lived in Aberdeen, South Dakota, where he was secretary of its Equal Suffrage Club, much of the politics in the Republican Aberdeen Saturday Pioneer dealt with trying to convince the populace to vote for women's suffrage. Susan B. Anthony visited Aberdeen and stayed with the Baums. Nancy Tystad Koupal notes an apparent loss of interest in editorializing after Aberdeen failed to pass the bill for women's enfranchisement. Sally Roesch Wagner of The Matilda Joslyn Gage Foundation published The Wonderful Mother of Oz, describing how Matilda Gage's feminist politics were sympathetically channeled by Baum into his Oz books. Some of Baum's contacts with suffragists of his day seem to have inspired much of The Marvelous Land of Oz. In this story, General Jinjur leads the girls and women of Oz in a revolt, armed with knitting needles; they succeed and make the men do the household chores. Jinjur proves to be an incompetent ruler, but Princess Ozma, who advocates gender equality, is ultimately placed on the throne. Charlotte Perkins Gilman's 1915 classic of feminist science fiction, Herland, bears strong similarities to The Emerald City of Oz(1910); the link between Baum and Gilman is considered to be Gage. Baum's stories outside of Oz also contain feminist or egalitarian themes. His Edith Van Dyne stories depict girls and young women engaging in traditionally masculine activities, including Aunt Jane's Nieces and The Flying Girl and its sequel. The Bluebird Books feature a girl sleuth. Racial views During the period surrounding the 1890 Ghost Dance movement and Wounded Knee Massacre, Baum wrote two editorials asserting that the safety of white settlers depended on the wholesale genocide of American Indians. These editorials were re-published in 1990 by sociologist Robert Venables of Cornell University, who argues that Baum was not using sarcasm. The first piece was published on December 20, 1890, five days after the killing of the Lakota Sioux holy man, Sitting Bull.Rogers, p. 259. The piece opined that with Sitting Bull's death, "the nobility of the Redskin" had been extinguished, and the safety of the frontier would not be established until there was "total annihilation" of the remaining Native Americans, who, he claimed, lived as "miserable wretches." Baum said that their extermination should not be regretted, and their elimination would "do justice to the manly characteristics" of their ancestors. The Wounded Knee Massacre occurred nine days later; the second editorial was published on January 3, 1891. Baum alleged that General Nelson A. Miles' weak rule of the Native Americans had caused American soldiers to suffer a "terrible loss of blood", in a "battle" which had been a disgrace to the Department of War. He found that the "disaster" could have easily been prevented with proper preparations. Baum reiterated that he believed, due to the history of mistreatment of Native Americans, that the extermination of the "untamed and untamable" tribes was necessary to protect American settlers. Baum ended the editorial with the following anecdote: "An eastern contemporary, with a grain of wisdom in its wit, says that 'when the whites win a fight, it is a victory, and when the Indians win it, it is a massacre.'" In 2006, two descendants of Baum apologized to the Sioux nation for any hurt that their ancestor had caused. The short story "The Enchanted Buffalo" claims to be a legend about a tribe of bison, and it states that a key element of it made it into the legends of Native American tribes. Baum mentions his characters' distaste for a Hopi snake dance in Aunt Jane's Nieces and Uncle John, but he also deplores the horrible situation which exists on Indian Reservations. Aunt Jane's Nieces on the Ranch features a hard-working Mexican in order to disprove Anglo stereotypes which portray Mexicans as lazy. Baum's mother-in-law and woman's suffrage leader Matilda Joslyn Gage strongly influenced his views. Gage was initiated into the Wolf Clan and admitted into the Iroquois Council of Matrons in recognition of her outspoken respect and sympathy for Native American people. Political imagery in The Wizard of Oz Numerous political references to the "Wizard" appeared early in the 20th century. Henry Littlefield, an upstate New York high school history teacher, wrote a scholarly article in 1964, the first full-fledged interpretation of the novel as an extended metaphor of the politics and characters of the 1890s. He paid special attention to the Populist metaphors and debates over silver and gold. Baum was a Republican and avid supporter of women's suffrage, and it is thought that he did not support the political ideals of either the Populist movement of 1890–1892 or the Bryanite silver crusade of 1896–1900. He published a poem in support of William McKinley. Since 1964, many scholars, economists, and historians have expanded on Littlefield's interpretation, pointing to multiple similarities between the characters (especially as depicted in Denslow's illustrations) and stock figures from editorial cartoons of the period. Littlefield wrote to The New York Times letters to the editor section spelling out that his theory had no basis in fact, but that his original point was "not to label Baum, or to lessen any of his magic, but rather, as a history teacher at Mount Vernon High School, to invest turn-of-the-century America with the imagery and wonder I have always found in his stories." Baum's newspaper had addressed politics in the 1890s, and Denslow was an editorial cartoonist as well as an illustrator of children's books. A series of political references is included in the 1902 stage version, such as references to the President, to a powerful senator, and to John D. Rockefeller for providing the oil needed by the Tin Woodman. Scholars have found few political references in Baum's Oz books after 1902. Baum was asked whether his stories had hidden meanings, but he always replied that they were written to "please children". Religion Baum was originally a Methodist, but he joined the Episcopal Church in Aberdeen in order to participate in community theatricals. Later, he and his wife were encouraged to become members of the Theosophical Society in 1892 by Matilda Joslyn Gage. Baum's beliefs are frequently reflected in his writings; however, the only mention of a church in his Oz books is the porcelain one which the Cowardly Lion breaks in the Dainty China Country in The Wonderful Wizard of Oz. The Baums sent their older sons to "Ethical Culture Sunday School" in Chicago, which taught morality, not religion.Michael Patrick Hearn. The Annotated Wizard of Oz. 2nd Edition. 2000. pp. 7, 271, 328. Writers including Evan I. Schwartz among others have suggested that Baum intentionally used allegory and symbolism in The Wonderful Wizard of Oz to convey concepts that are central to spiritual teachings such as Theosophy and Buddhism. They postulate that the main characters’ experiences in Oz represent the soul’s journey toward enlightenment. Schwartz specifically states that key plot elements of the book take “the reader on a journey guided by Eastern philosophy” (Schwartz, p. 265). An article in BBC Culture lists several allegorical interpretations of the book including that it may be viewed as a parable of Theosophy. The article cites various symbols and their possible meanings, for example the Yellow Brick Road representing the ‘Golden Path’ in Buddhism, along which the soul travels to a state of spiritual realization. Baum’s own writing suggests he believed the story may have been divinely inspired: “It was pure inspiration. It came to me right out of the blue. I think that sometimes the Great Author had a message to get across and He was to use the instrument at hand”. Bibliography Works Mother Goose in Prose (1897) By the Candelabra's Glare (1898) Father Goose: His Book (1899) A New Wonderland (1900) The Army Alphabet (1900) The Navy Alphabet (1900) American Fairy Tales (1901) The Life and Adventures of Santa Claus (1902) The Boy Fortune Hunters in Egypt (1908) The Boy Fortune Hunters in Panama (1908) Fortune Hunters in China The Boy Fortune Hunters in the South Seas (1911) The Sea Fairies (1911) Sky Island (1912) Queen Zixi of Ix (1905) The Fate of a Crown (1905) Sam Steele's Adventures on Land and Sea (1906) Daughters of Destiny (novel) (1906) The Last Egyptian (1907) Land of Oz worksThe Wonderful Wizard of Oz (1900)The Marvelous Land of Oz (1904)Queer Visitors from the Marvelous Land of Oz (1905, comic strip depicting 27 stories)The Woggle-Bug Book (1905)Ozma of Oz (1907)Dorothy and the Wizard in Oz (1908)The Road to Oz (1909)The Emerald City of Oz (1910)The Patchwork Girl of Oz (1913)Little Wizard Stories of Oz (1913, collection of 6 short stories)Tik-Tok of Oz (1914)The Scarecrow of Oz (1915)Rinkitink in Oz (1916)The Lost Princess of Oz (1917)The Tin Woodman of Oz (1918)The Magic of Oz (1919, posthumously published)Glinda of Oz (1920, posthumously published) 1921's The Royal Book of Oz was posthumously attributed to Baum but was entirely the work of Ruth Plumly Thompson. Popular culture and legacy A 1970 episode of the long-running American Western anthology series Death Valley Days presents a highly romanticized portrayal of Baum's time in South Dakota. The comedic teleplay, titled "The Wizard of Aberdeen", stars Conlan Carter as Baum and Beverlee McKinsey as Maud. Although the 30-minute presentation touches on Baum's family life and his struggles in Aberdeen as a newspaper editor, it focuses principally on his storytelling to local children about characters in a distant land he initially refers to as "Ooz". John Ritter portrayed Baum in the television film The Dreamer of Oz: The L. Frank Baum Story (1990). The theme park Storybook Land, located in Aberdeen, South Dakota, features the Land of Oz, with characters and attractions from the books. In the short-lived 2008 TV series Terminator: The Sarah Connor Chronicles, the show's protagonist John Connor enrolls in high school under the name of "John Baum" (after L. Frank Baum) to keep his true identity a secret. His mother Sarah had mentioned to Cameron that The Wonderful Wizard Of Oz was John's favorite book when he was younger. In 2013, Baum was inducted into the Chicago Literary Hall of Fame. Chittenango, New York holds a three-day annual festival called Oz-Stravaganza! to celebrate the literary works of author L. Frank Baum, who was born in Chittenango on May 15, 1856. The children's novel The Wonderful Wizard of Oz was published on May 17, 1900. The weekend-long festival, usually held during the first Saturday of June and the weekend thereof, includes a parade, which features many community groups. The parade has also featured actors and actresses who played Munchkins in the 1939 film The Wizard of Oz, including Jerry Maren, Karl Slover, Meinhardt Raabe, and Margaret Williams Pellegrini. See also Notes References Algeo, John. "A Notable Theosophist: L. Frank Baum." American Theosophist, Vol. 74 (August–September 1986), pp. 270–3. Attebery, Brian. The Fantasy Tradition in American Literature. Bloomington, IN, Indiana University Press, 1980. Baum, Frank Joslyn, and Russell P. Macfall. To Please a Child. Chicago, Reilly & Lee, 1961. Baum, L. Frank. The Annotated Wizard of Oz. Edited with an Introduction and Notes by Michael Patrick Hearn. New York, Clarkson N. Potter, 1973. Revised 2000. New York, W.W. Norton, 2000. Ford, Alla T. The High-Jinks of L. Frank Baum. Hong Kong, Ford Press, 1969. Ford, Alla T. The Musical Fantasies of L. Frank Baum. Lake Worth, FL, Ford Press, 1969. Gardner, Martin, and Russel B. Nye. The Wizard of Oz and Who He Was. East Lansing, MI, Michigan State University Press, 1957. Revised 1994. Hearn, Michael Patrick. The Critical Heritage Edition of the Wizard of Oz. New York, Schocken, 1986. Koupal, Nancy Tystad. Baum's Road to Oz: The Dakota Years. Pierre, SD, South Dakota State Historical Society, 2000. Koupal, Nancy Tystad. Our Landlady. Lawrence, KS, University of Nebraska Press, 1986. Parker, David B. The Rise and Fall of The Wonderful Wizard of Oz as a "Parable on Populism" Journal of the Georgia Association of Historians, vol. 15 (1994), pp. 49–63. Reneau, Reneau H. "Misanthropology: A Florilegium of Bahumbuggery" Inglewood, CA, donlazaro translations, 2004, pp. 155–164 Reneau, Reneau H. "A Newer Testament: Misanthropology Unleashed" Inglewood, CA, donlazaro translations, 2008, pp. 129–147 Riley, Michael O. Oz and Beyond: The Fantasy World of L. Frank Baum. Lawrence, KS, University of Kansas Press, 1997. Rogers, Katharine M. L. Frank Baum, Creator of Oz: A Biography. New York, St. Martin's Press, 2002. Sale, Roger. Fairy Tales and After: From Snow White to E. B. White. Cambridge, MA, Harvard University press, 1978. Schwartz, Evan I. Finding Oz: How L. Frank Baum Discovered the Great American Story. New York, Houghton Mifflin Harcourt, 2009 Wagner, Sally Roesch. The Wonderful Mother of Oz. Fayetteville, NY: The Matilda Joslyn Gage Foundation, 2003. Wilgus, Neal. "Classic American Fairy Tales: The Fantasies of L. Frank Baum" in Darrell Schweitzer (ed) Discovering Classic Fantasy Fiction'', Gillette NJ: Wildside Press, 1996, pp. 113–121. External links The Complete Oz Works L. Frank Baum Papers at Syracuse University Bibliography (Baum and Oz) The International Wizard of Oz Club, Inc. Wonderful Wizard of Oz Website Copyright Registration Application from Claimant L. Frank Baum for The wonderful Wizard of Oz From the Collections at the Library of Congress Finding aid to Roland Orvil Baughman collection about L. Frank Baum at Columbia University, Rare Book & Manuscript Library 1856 births 1919 deaths 19th-century American male actors 19th-century American newspaper editors 19th-century American newspaper publishers (people) 19th-century American novelists 20th-century American novelists 19th-century male writers 20th-century American male writers 20th-century American poets American male short story writers 20th-century American male actors American children's writers American fantasy writers American feminist writers American film producers American Methodists American people of English descent American people of German descent American people of Scotch-Irish descent American male silent film actors American male stage actors American suffragists American Theosophists Burials at Forest Lawn Memorial Park (Glendale) Children's poets Male feminists Oz (franchise) People from Aberdeen, South Dakota People from Chittenango, New York Peekskill Military Academy alumni Writers from Syracuse, New York Silent film directors Writers from Chicago New York (state) Republicans South Dakota Republicans California Republicans American male poets American male novelists Journalists from South Dakota Journalists from New York (state) Stamp dealers Novelists from Illinois American male non-fiction writers Male novelists 19th-century pseudonymous writers 20th-century pseudonymous writers	[ 0.0344829298555851, 0.4699510335922241, -0.5394211411476135, 0.20215222239494324, 0.5091267824172974, -0.2234635353088379, 0.28565913438796997, 0.541877269744873, 0.008276181295514107, -0.38490810990333557, -0.6402229070663452, 0.07861579209566116, -0.4108956754207611, 0.6136518120765686, ...
18189	https://en.wikipedia.org/wiki/Lake%20Ladoga	Lake Ladoga	Lake Ladoga ( or , [earlier in Finnish Nevajärvi]; ; ) is a freshwater lake located in the Republic of Karelia and Leningrad Oblast in northwestern Russia, in the vicinity of Saint Petersburg. It is the largest lake located entirely in Europe, the second largest lake after Baikal in Russia, and the 14th largest freshwater lake by area in the world. Ladoga Lacus, a methane lake on Saturn's moon Titan, is named after the lake. Etymology In one of Nestor's chronicles from the 12th century a lake called "the Great Nevo" is mentioned, a clear link to the Neva River and possibly further to Finnish nevo 'sea' or neva 'bog, quagmire'. Ancient Norse sagas and Hanseatic treaties both mention a city made of lakes named Old Norse Aldeigja or Aldoga. Since the beginning of the 14th century this hydronym was commonly known as Ladoga. According to T. N. Jackson, it can be taken "almost for granted that the name of Ladoga first referred to the river, then the city, and only then the lake". Therefore, he considers the primary hydronym Ladoga to originate in the eponymous inflow to the lower reaches of the Volkhov River whose early Finnic name was Alodejoki (corresponding to modern ) 'river of the lowlands'. The Germanic toponym (Aldeigja ~ Aldoga) was soon borrowed by the Slavic population and transformed by means of the Old East Slavic metathesis ald- → lad- to . The Old Norse intermediary word between Finnish and Old East Slavic word is fully supported by archeology, since the Scandinavians first appeared in Ladoga in the early 750s, that is, a couple of decades before the Slavs. Other hypotheses about the origin of the name derive it from 'wave' and 'wavy', or from the Russian dialectal word алодь, meaning 'open lake, extensive water field'. Eugene Helimski by contrast, offers an etymology rooted in German. In his opinion, the primary name of the lake was 'old source', associated to the open sea, in contrast to the name of the Neva River (flowing from Lake Ladoga) which would derive from the German expression for 'the new'. Through the intermediate form *Aldaugja, came about, referring to the city of Ladoga. Geography The lake has an average surface area of 17,891 km2 (excluding the islands), slightly larger than Kuwait. Its north-to-south length is 219 km and its average width is 83 km; the average depth is 51 m, although it reaches a maximum of 230 m in the north-western part. Basin area: 276,000 km2, volume: 837 km3 (earlier estimated as 908 km3). There are around 660 islands, with a total area of about 435 km2. Ladoga is, on average, 5 m above sea level. Most of the islands, including the famous Valaam archipelago, Kilpola and Konevets, are situated in the northwest of the lake. Separated from the Baltic Sea by the Karelian Isthmus, it drains into the Gulf of Finland via the Neva River. Lake Ladoga is navigable, being a part of the Volga-Baltic Waterway connecting the Baltic Sea with the Volga River. The Ladoga Canal bypasses the lake in the south, connecting the Neva to the Svir. The basin of Lake Ladoga includes about 50,000 lakes and 3,500 rivers longer than 10 km. About 85% of the water inflow is due to tributaries, 13% is due to precipitation, and 2% is due to underground waters. Geological history Geologically, the Lake Ladoga depression is a graben and syncline structure of Proterozoic age (Precambrian). This "Ladoga–Pasha structure", as it is known, hosts Jotnian sediments. During the Pleistocene glaciations the depression was partially stripped of its sedimentary rock fill by glacial overdeepening. During the Last Glacial Maximum, about 17,000 years BP, the lake served likely as a channel that concentrated ice of the Fennoscandian Ice Sheet into an ice stream that fed glacier lobes further east. Deglaciation following the Weichselian glaciation took place in the Lake Ladoga basin between 12,500 and 11,500 radiocarbon years BP. Lake Ladoga was initially part of the Baltic Ice Lake (70–80 m. above present sea level), a historical freshwater stage of Baltic Sea. It is possible, though not certain, that Ladoga was isolated from it during regression of the subsequent Yoldia Sea brackish stage (10,200–9,500 BP). The isolation threshold should be at Heinjoki to the east of Vyborg, where the Baltic Sea and Ladoga were connected by a strait or a river outlet at least until the formation of the River Neva, and possibly even much later, until the 12th century AD or so. At 9,500 BP, Lake Onega, previously draining into the White Sea, started emptying into Ladoga via the River Svir. Between 9,500 and 9,100 BP, during the transgression of Ancylus Lake, the next freshwater stage of the Baltic, Ladoga certainly became part of it, even if they hadn't been connected immediately before. During the Ancylus Lake subsequent regression, around 8,800 BP Ladoga became isolated. Ladoga slowly transgressed in its southern part due to uplift of the Baltic Shield in the north. It has been hypothesized, but not proven, that waters of the Litorina Sea, the next brackish-water stage of the Baltic, occasionally invaded Ladoga between 7,000 and 5,000 BP. Around 5,000 BP the waters of the Saimaa Lake penetrated Salpausselkä and formed a new outlet, River Vuoksi, entering Lake Ladoga in the northwestern corner and raising its level by 1–2 m. The River Neva originated when the Ladoga waters at last broke through the threshold at Porogi into the lower portions of Izhora River, then a tributary of the Gulf of Finland, between 4,000 and 2,000 BP. Dating of some sediments in the northwestern part of Lake Ladoga suggests it happened at 3,100 radiocarbon years BP (3,410–3,250 calendar years BP). Wildlife The Ladoga is rich with fish. 48 forms (species and infra specific taxa) of fish have been encountered in the lake, including roach, carp bream, zander, European perch, ruffe, endemic variety of smelt, two varieties of Coregonus albula (vendace), eight varieties of Coregonus lavaretus, a number of other Salmonidae as well as, albeit rarely, endangered Atlantic sturgeon (formerly confused with European sea sturgeon). Commercial fishing was once a major industry but has been hurt by overfishing. After the war, between 1945–1954, the total annual catch increased and reached a maximum of 4,900 tonnes. However, unbalanced fishery led to the drastic decrease of catch in 1955–1963, sometimes to 1,600 tonnes per year. Trawling has been forbidden in Lake Ladoga since 1956 and some other restrictions were imposed. The situation gradually recovered, and in 1971–1990 the catch ranged between 4,900 and 6,900 tonnes per year, about the same level as the total catch in 1938. Fish farms and recreational fishing are developing. It has its own endemic ringed seal subspecies known as the Ladoga seal. Since the beginning of the 1960s Ladoga has become considerably eutrophicated. Nizhnesvirsky Natural Reserve is situated along the shore of Lake Ladoga immediately to the north of the mouth of the River Svir. The Ladoga has a population of Arctic char that is genetically close to the chars of Lake Sommen and Lake Vättern in southern Sweden. History In the Middle Ages, the lake formed a vital part of the trade route from the Varangians to the Eastern Roman Empire, with the Norse emporium at Staraya Ladoga defending the mouth of the Volkhov since the 8th century. In the course of the Swedish–Novgorodian Wars, the area was disputed between the Novgorod Republic and Sweden. In the early 14th century, the fortresses of Korela (Kexholm) and Oreshek (Nöteborg) were established along the banks of the lake. The ancient Valaam Monastery was founded on the island of Valaam, the largest in Lake Ladoga, abandoned between 1611–1715, restored in the 18th century, and evacuated to Finland during the Winter War in 1940. In 1989 the monastic activities in the Valaam were resumed. Other historic cloisters in the vicinity are the Konevets Monastery, which sits on the Konevets island, and the Alexander-Svirsky Monastery, which preserves samples of medieval Muscovite architecture. During the Ingrian War, a fraction of the Ladoga coast was occupied by Sweden. In 1617, by the Treaty of Stolbovo, the northern and western coast was ceded by Russia to Sweden. In 1721, after the Great Northern War, it was restitutioned to Russia by the Treaty of Nystad. In the 18th century, the Ladoga Canal was built to bypass the lake which was prone to winds and storms that destroyed hundreds of cargo ships. Later, from around 1812–1940 the lake was shared between Finland and Russia. According to the conditions of the 1920 Tartu Peace Treaty militarization of the lake was severely restricted. However, both Soviet Russia and Finland had flotillas in Ladoga (see also Finnish Ladoga Naval Detachment). After the Winter War (1939–40) according to the Moscow Peace Treaty, Ladoga, previously shared with Finland, became an internal basin of the Soviet Union. During World War II not only Finnish and Soviet, but also German and Italian vessels operated there (see also Naval Detachment K and Regia Marina). Under these circumstances, during much of the Siege of Leningrad (1941–44), Lake Ladoga provided the only access to the besieged city as a section of the eastern shore remained in Soviet hands. Supplies were transported into Leningrad with trucks on winter roads over the ice, the "Road of Life", and by boat in the summer. After World War II, Finland lost the Karelia region again to the USSR, and all Finnish citizens were evacuated from the ceded territory. Ladoga became an internal Soviet basin once again. The northern shore, Ladoga Karelia with the town of Sortavala, is now part of the Republic of Karelia. The western shore, Karelian Isthmus, became part of Leningrad Oblast. Lists Tributaries (incomplete list) Svir River from Lake Onega (south-east, discharge: 790 m3/s); Volkhov River from Lake Ilmen (south, discharge: 580 m3/s); Vuoksi River (and Burnaya River) from Lake Saimaa in Finland (west, discharge: 540 m3/s). Syas River (south, discharge: 53 m3/s). Olonka River from Lake Utozero Towns upon the lake Shlisselburg (at ) Novaya Ladoga (at ) Syasstroy (at ) Pitkyaranta (at ) Sortavala (at ) Lakhdenpokhya (at ) Priozersk (at ) Image gallery References External links Simola, Heikki et al. (eds), Proceeding of The First International Lake Ladoga Symposium. Special issue of Hydrobiologia. Vol. 322, Issues 1–3. / April 1996. Ladoga Lake (photos) War on Lake Ladoga, 1941–1944 Maps Ladoga LLadoga Karelian Isthmus Ladoga Mesoproterozoic rifts and grabens Ladoga	[ -0.3519824743270874, 0.12267608195543289, 0.2060319185256958, 0.01925192028284073, 0.19297462701797485, 0.024715285748243332, 0.5537667274475098, 0.5404919981956482, -0.3179166913032532, 0.11784512549638748, -0.5447367429733276, -0.1768912971019745, -0.27862057089805603, 0.6055291295051575...
18190	https://en.wikipedia.org/wiki/Language%20family	Language family	A language family is a group of languages related through descent from a common ancestral language or parental language, called the proto-language of that family. The term "family" reflects the tree model of language origination in historical linguistics, which makes use of a metaphor comparing languages to people in a biological family tree, or in a subsequent modification, to species in a phylogenetic tree of evolutionary taxonomy. Linguists therefore describe the daughter languages within a language family as being genetically related. According to Ethnologue there are 7,139 living human languages distributed in 142 different language families. A living language is defined as one that is the first language of at least one person. There are also many dead languages, or languages which have no native speakers living, and extinct languages, which have no native speakers and no descendant languages. Finally, there are some languages that are insufficiently studied to be classified, and probably some which are not even known to exist outside their respective speech communities. Membership of languages in a language family is established by research in comparative linguistics. Sister languages are said to descend "genetically" from a common ancestor. Speakers of a language family belong to a common speech community. The divergence of a proto-language into daughter languages typically occurs through geographical separation, with the original speech community gradually evolving into distinct linguistic units. Individuals belonging to other speech communities may also adopt languages from a different language family through the language shift process. Genealogically related languages present shared retentions; that is, features of the proto-language (or reflexes of such features) that cannot be explained by chance or borrowing (convergence). Membership in a branch or group within a language family is established by shared innovations; that is, common features of those languages that are not found in the common ancestor of the entire family. For example, Germanic languages are "Germanic" in that they share vocabulary and grammatical features that are not believed to have been present in the Proto-Indo-European language. These features are believed to be innovations that took place in Proto-Germanic, a descendant of Proto-Indo-European that was the source of all Germanic languages. Structure of a family Language families can be divided into smaller phylogenetic units, conventionally referred to as branches of the family because the history of a language family is often represented as a tree diagram. A family is a monophyletic unit; all its members derive from a common ancestor, and all attested descendants of that ancestor are included in the family. (Thus, the term family is analogous to the biological term clade.) Some taxonomists restrict the term family to a certain level, but there is little consensus in how to do so. Those who affix such labels also subdivide branches into groups, and groups into complexes. A top-level (i.e., the largest) family is often called a phylum or stock. The closer the branches are to each other, the more closely the languages will be related. This means if a branch off of a proto-language is four branches down and there is also a sister language to that fourth branch, then the two sister languages are more closely related to each other than to that common ancestral proto-language. The term macrofamily or superfamily is sometimes applied to proposed groupings of language families whose status as phylogenetic units is generally considered to be unsubstantiated by accepted historical linguistic methods. There is a remarkably similar pattern shown by the linguistic tree and the genetic tree of human ancestry that was verified statistically. Languages interpreted in terms of the putative phylogenetic tree of human languages are transmitted to a great extent vertically (by ancestry) as opposed to horizontally (by spatial diffusion). Dialect continua Some close-knit language families, and many branches within larger families, take the form of dialect continua in which there are no clear-cut borders that make it possible to unequivocally identify, define, or count individual languages within the family. However, when the differences between the speech of different regions at the extremes of the continuum are so great that there is no mutual intelligibility between them, as occurs in Arabic, the continuum cannot meaningfully be seen as a single language. A speech variety may also be considered either a language or a dialect depending on social or political considerations. Thus, different sources, especially over time, can give wildly different numbers of languages within a certain family. Classifications of the Japonic family, for example, range from one language (a language isolate with dialects) to nearly twenty—until the classification of Ryukyuan as separate languages within a Japonic language family rather than dialects of Japanese, the Japanese language itself was considered a language isolate and therefore the only language in its family. Isolates Most of the world's languages are known to be related to others. Those that have no known relatives (or for which family relationships are only tentatively proposed) are called language isolates, essentially language families consisting of a single language. There are an estimated 129 language isolates known today. An example is Basque. In general, it is assumed that language isolates have relatives or had relatives at some point in their history but at a time depth too great for linguistic comparison to recover them. It is commonly misunderstood that language isolates are classified as such because there is not sufficient data on or documentation of the language. This is false because a language isolate is classified based on the fact that enough is known about the isolate to compare it genetically to other languages but no common ancestry or relationship is found with any other known language. A language isolated in its own branch within a family, such as Albanian and Armenian within Indo-European, is often also called an isolate, but the meaning of the word "isolate" in such cases is usually clarified with a modifier. For instance, Albanian and Armenian may be referred to as an "Indo-European isolate". By contrast, so far as is known, the Basque language is an absolute isolate: it has not been shown to be related to any other modern language despite numerous attempts. Another well-known isolate is Mapudungun, the Mapuche language from the Araucanían language family in Chile. A language may be said to be an isolate currently but not historically if related but now extinct relatives are attested. The Aquitanian language, spoken in Roman times, may have been an ancestor of Basque, but it could also have been a sister language to the ancestor of Basque. In the latter case, Basque and Aquitanian would form a small family together. (Ancestors are not considered to be distinct members of a family.) Proto-languages A proto-language can be thought of as a mother language (not to be confused with a mother tongue, which is one that a specific person has been exposed to from birth), being the root which all languages in the family stem from. The common ancestor of a language family is seldom known directly since most languages have a relatively short recorded history. However, it is possible to recover many features of a proto-language by applying the comparative method, a reconstructive procedure worked out by 19th century linguist August Schleicher. This can demonstrate the validity of many of the proposed families in the list of language families. For example, the reconstructible common ancestor of the Indo-European language family is called Proto-Indo-European. Proto-Indo-European is not attested by written records and so is conjectured to have been spoken before the invention of writing. Other classifications of languages Sprachbund A sprachbund is a geographic area having several languages that feature common linguistic structures. The similarities between those languages are caused by language contact, not by chance or common origin, and are not recognized as criteria that define a language family. An example of a sprachbund would be the Indian subcontinent. Shared innovations, acquired by borrowing or other means, are not considered genetic and have no bearing with the language family concept. It has been asserted, for example, that many of the more striking features shared by Italic languages (Latin, Oscan, Umbrian, etc.) might well be "areal features". However, very similar-looking alterations in the systems of long vowels in the West Germanic languages greatly postdate any possible notion of a proto-language innovation (and cannot readily be regarded as "areal", either, since English and continental West Germanic were not a linguistic area). In a similar vein, there are many similar unique innovations in Germanic, Baltic and Slavic that are far more likely to be areal features than traceable to a common proto-language. But legitimate uncertainty about whether shared innovations are areal features, coincidence, or inheritance from a common ancestor, leads to disagreement over the proper subdivisions of any large language family. Contact languages The concept of language families is based on the historical observation that languages develop dialects, which over time may diverge into distinct languages. However, linguistic ancestry is less clear-cut than familiar biological ancestry, in which species do not crossbreed. It is more like the evolution of microbes, with extensive lateral gene transfer: Quite distantly related languages may affect each other through language contact, which in extreme cases may lead to languages with no single ancestor, whether they be creoles or mixed languages. In addition, a number of sign languages have developed in isolation and appear to have no relatives at all. Nonetheless, such cases are relatively rare and most well-attested languages can be unambiguously classified as belonging to one language family or another, even if this family's relation to other families is not known. Language contact can lead to the development of new languages from the mixture of two or more languages for the purposes of interactions between two groups who speak different languages. Languages that arise in order for two groups to communicate with each other to engage in commercial trade or that appeared as a result of colonialism are called pidgin. Pidgins are an example of linguistic and cultural expansion caused by language contact. However, language contact can also lead to cultural divisions. In some cases, two different language speaking groups can feel territorial towards their language and do not want any changes to be made to it. This causes language boundaries and groups in contact are not willing to make any compromises to accommodate the other language. See also Constructed language Endangered language Extinct language Language death List of revived languages Global language system ISO 639-5 Linguist List List of language families List of languages by number of native speakers Origin of language Proto-language Proto-Human language Tree model Unclassified language Father Tongue hypothesis Farming/language dispersal hypothesis References Further reading Boas, Franz. (1922). Handbook of American Indian languages (Vol. 2). Bureau of American Ethnology, Bulletin 40. Washington, D.C.: Government Print Office (Smithsonian Institution, Bureau of American Ethnology). Boas, Franz. (1933). Handbook of American Indian languages (Vol. 3). Native American legal materials collection, title 1227. Glückstadt: J.J. Augustin. Campbell, Lyle. (1997). American Indian languages: The historical linguistics of Native America. New York: Oxford University Press. . Campbell, Lyle; & Mithun, Marianne (Eds.). (1979). The languages of native America: Historical and comparative assessment. Austin: University of Texas Press. Goddard, Ives (Ed.). (1996). Languages. Handbook of North American Indians (W. C. Sturtevant, General Ed.) (Vol. 17). Washington, D.C.: Smithsonian Institution. . Goddard, Ives. (1999). Native languages and language families of North America (rev. and enlarged ed. with additions and corrections). [Map]. Lincoln, NE: University of Nebraska Press (Smithsonian Institution). (Updated version of the map in Goddard 1996). . Gordon, Raymond G., Jr. (Ed.). (2005). Ethnologue: Languages of the world (15th ed.). Dallas, TX: SIL International. . (Online version: Ethnologue: Languages of the World). Greenberg, Joseph H. (1966). The Languages of Africa (2nd ed.). Bloomington: Indiana University. Harrison, K. David. (2007) When Languages Die: The Extinction of the World's Languages and the Erosion of Human Knowledge. New York and London: Oxford University Press. Mithun, Marianne. (1999). The languages of Native North America. Cambridge: Cambridge University Press. (hbk); . Ross, Malcolm. (2005). "Pronouns as a preliminary diagnostic for grouping Papuan languages". In: Andrew Pawley, Robert Attenborough, Robin Hide and Jack Golson, eds, Papuan pasts: cultural, linguistic and biological histories of Papuan-speaking peoples (PDF) Ruhlen, Merritt. (1987). A guide to the world's languages. Stanford: Stanford University Press. Sturtevant, William C. (Ed.). (1978–present). Handbook of North American Indians (Vol. 1–20). Washington, D.C.: Smithsonian Institution. (Vols. 1–3, 16, 18–20 not yet published). Voegelin, C. F. & Voegelin, F. M. (1977). Classification and index of the world's languages. New York: Elsevier. External links Linguistic maps (from Muturzikin) Ethnologue The Multitree Project Lenguas del mundo (World Languages) Comparative Swadesh list tables of various language families (from Wiktionary) Most similar languages Historical linguistics	[ 0.23549264669418335, 0.31306585669517517, -0.554986298084259, 0.054964739829301834, 0.11605996638536453, 0.5551788210868835, 0.6536826491355896, 0.4489865303039551, -0.36875107884407043, -0.8645976781845093, -0.43920621275901794, -0.04464799165725708, -0.030057502910494804, 0.3966460824012...
18194	https://en.wikipedia.org/wiki/Looe%20Island	Looe Island	Looe Island (, meaning Island of the Monk's Enclosure), also known as St George's Island, and historically St Michael's Island is a small island nature reserve a mile from the mainland town of Looe off Cornwall, England. According to local legend, Joseph of Arimathea landed here with the Christ Child. Some scholars, including Glyn S. Lewis, suggest the island could be Ictis, the location described by Diodorus Siculus as a centre for the tin trade in pre-Roman Britain. The island is now owned and managed by the Cornwall Wildlife Trust charity where access (including landing on the foreshore and flying of drones over the island) is carefully managed for the benefit of wildlife and landing is only possible via the Cornwall Wildlife Trust authorized boatman. The waters around the island are a marine nature reserve and form part of the Looe Voluntary Marine Conservation Area (VMCA). First established in 1995, the Looe VCMA covers nearly 5 km of coastline and aims to protect the coastal and marine wildlife around Looe. History People have been living on Looe Island since the Iron Age. Evidence of early habitation includes pieces of Roman amphorae as well as stone boat anchors and Roman coins. A number of late prehistoric or Romano-British finds have been made in the vicinity of the island, including a large bronze ingot found by divers south of Looe Island, which has led a number of people to suggest the island is possibly Ictis, the tin trading island seen by Pytheas in the 4th century BC and recalled by Diodorus Siculus in the 1st century BC. A small hoard of eight late Roman coins was recovered in 2008. These coins were recovered from one of the shallow ditches forming a 'pear shaped enclosure' which encompassed the top of Looe Island and the later Christian chapel site. All eight coins date to the late 3rd or early 4th century AD. In the Dark Ages, the island was used a seat of early Christian settlement. The child Jesus was believed to have visited the Island with his uncle, Joseph of Arimathea, who traded with the Cornish tin traders. Looe Island was already a place of pilgrimage for early Christians before the creation of this story and a small thatched roofed chapel was built there during this time. In the later medieval period, the island came under the overall control of Glastonbury Abbey, with the Prior of Lammana being directly responsible for its governance; the island's chapel was under the care of two Benedictine monks until 1289 when the property was sold to a local landowner. The priory was replaced by a domestic chapel served by a secular priest until the Dissolution of the Monasteries in 1536 when it became property of the Crown. From the 13th to the 16th centuries it was known as St Michael's Island but after the dissolution of the monasteries, it was rededicated in 1594 as St George's Island. Through the 17th and 18th centuries the island was used by smugglers to avoid the British Government's revenue cutters out of Plymouth and Falmouth. The Old Guildhall Museum in Looe holds information and research about the smuggling families of Looe Island and information is also available in the more recent publications about the island. During the Second World War, Looe Island was for a time renamed as 'H.M.S St. George', following the dropping of a probable parachute mine which resulted in a large crater in the summit. It was believed the island was mistaken for an Allied ship. The incident was recorded in The Cornish Times under the headline "H.M.S St. George. Nazi Airman's Direct Hit Off Looe – Another 'Success' for the Luftwaffe". The article continued "H.M.S St. George is still riding peacefully at her anchorage in Looe Bay, after being bombed recently by a Nazi air-raider in what would seem to have been an attempt to sink her. Although St. George has occupied the same berth for millennia, and is as well-known to inhabitants and visitors to Looe as the palms of their hands, no one has determined to what particular class of battleship she belongs, indeed all are familiar with the shapely hulk lying seaward of Hannafore as Looe Island (or, cartographically St. Georges Island)". In the 20th century, Looe island was owned (and inhabited) by two sisters, Babs and Evelyn Atkins, who wrote two books: We Bought An Island and its sequel Tales From Our Cornish Island. They chronicle the purchase of the island and what it was like to live there. Evelyn died in 1997 at the age of 87; Babs continued to live on the island until her death in 2004, at the age of 86. On her death, the island was bequeathed to the Cornwall Wildlife Trust; it will be preserved as a nature reserve in perpetuity. Today the wardens for Cornwall Wildlife Trust live on the island and manage it for the benefit of wildlife. The adjoining islet, formerly known as Little Island, now renamed Trelawny Island and connected by a small bridge, was bequeathed by Miss Atkins back to the Trelawny family, who previously owned Looe Island from 1743 to 1921. Geography Situated in the English Channel, about one mile from East Looe in the direction of Polperro, it is about in area and a mile (1.6 km) in circumference. Its highest point is above sea level. Looe Island, like much of south west England, has a mild climate with frost and snow being rare. The island is owned and managed by the Cornwall Wildlife Trust. This is a non-profit-making venture, the landing fees and other income being devoted to conserving the island's natural environment and providing facilities. The island is open during the summer to day visitors arriving by the Trust's boat. After a short welcome talk visitors are directed to the small visitor centre from where they can pick up a copy of the self-guided trail. Visitors have some two hours on the island and all trips are subject to tides and weather/sea state. While it is normally accessible only by the Cornwall Wildlife Trust's boat, at extremely low spring tides it is possible for the journey to be made by foot across the slippery, seaweed-covered rocky sea floor. However you have to remain on the beach and promptly head back to the mainland. Media appearances In 2008, Channel 4's archaeology series Time Team visited the island to carry out an investigation into its early Christian history. They excavated the sites of Christian chapels built on both the island and on the mainland opposite. During their dig they found the remains of a Benedictine chapel that was built in c.1139 by monks from Glastonbury Abbey, a reliquary, graves and the remains of much earlier Anglo-Romano places of worship built of wood with dating evidence suggesting use by Christians before the reign of Constantine the Great. In 1994/95 Andrew Hugill composed Island Symphony, an electro-acoustic piece utilising sampled sounds sourced over the net plus recorded natural sounds from the island itself. In the TV comedy series Yes Prime Minister, there was mention of another St. George's Island, but this one was a fictitious place in the Arabian Sea. See also St Michael's Mount Mont Saint-Michel List of monastic houses in Cornwall References Further reading Looe Island Then and Now: Carolyn Clarke 2014 United P. C Publisher The Looe Island Story: an Illustrated History of St George's Island, Mike Dunn, 2006, Polperro Heritage Press, Island Life: A History of Looe Island, David Clensy, 2006 We Bought an Island: Evelyn E Atkins 1976 Tales from our Cornish Island: Evelyn E Atkins 0-340-22688-9 External links Cornwall Wildlife Trust Smuggling history Looe Marine Conservation Group Islands of Cornwall Nature reserves of the Cornwall Wildlife Trust Looe	[ 0.39426568150520325, 0.015814388170838356, 0.14952722191810608, -0.8010948300361633, 0.683597207069397, -0.028374388813972473, 0.2503803074359894, -0.08302954584360123, -0.3737170994281769, 0.4946039319038391, -0.42015427350997925, -0.012479419820010662, -0.20389556884765625, -0.4198268651...
18195	https://en.wikipedia.org/wiki/LaTeX	LaTeX	LaTeX ( or , often stylized as ) is a software system for document preparation. When writing, the writer uses plain text as opposed to the formatted text found in "What You See Is What You Get" word processors like Microsoft Word, LibreOffice Writer and Apple Pages. The writer uses markup tagging conventions to define the general structure of a document to stylise text throughout a document (such as bold and italics), and to add citations and cross-references. A TeX distribution such as TeX Live or MiKTeX is used to produce an output file (such as PDF or DVI) suitable for printing or digital distribution. LaTeX is widely used in academia for the communication and publication of scientific documents in many fields, including mathematics, computer science, engineering, physics, chemistry, economics, linguistics, quantitative psychology, philosophy, and political science. It also has a prominent role in the preparation and publication of books and articles that contain complex multilingual materials, such as Sanskrit and Greek. LaTeX uses the TeX typesetting program for formatting its output, and is itself written in the TeX macro language. LaTeX can be used as a standalone document preparation system, or as an intermediate format. In the latter role, for example, it is sometimes used as part of a pipeline for translating DocBook and other XML-based formats to PDF. The typesetting system offers programmable desktop publishing features and extensive facilities for automating most aspects of typesetting and desktop publishing, including numbering and cross-referencing of tables and figures, chapter and section headings, the inclusion of graphics, page layout, indexing and bibliographies. Like TeX, LaTeX started as a writing tool for mathematicians and computer scientists, but even from early in its development, it has also been taken up by scholars who needed to write documents that include complex math expressions or non-Latin scripts, such as Arabic, Devanagari and Chinese. LaTeX is intended to provide a high-level, descriptive markup language that accesses the power of TeX in an easier way for writers. In essence, TeX handles the layout side, while LaTeX handles the content side for document processing. LaTeX comprises a collection of TeX macros and a program to process LaTeX documents, and because the plain TeX formatting commands are elementary, it provides authors with ready-made commands for formatting and layout requirements such as chapter headings, footnotes, cross-references and bibliographies. LaTeX was originally written in the early 1980s by Leslie Lamport at SRI International. The current version is LaTeX2e (stylised as ), released in 1994, but updated in 2020. LaTeX3 () has been under long-term development since the early 1990s. LaTeX is free software and is distributed under the LaTeX Project Public License (LPPL). Typesetting system LaTeX attempts to follow the design philosophy of separating presentation from content, so that authors can focus on the content of what they are writing without attending simultaneously to its visual appearance. In preparing a LaTeX document, the author specifies the logical structure using simple, familiar concepts such as chapter, section, table, figure, etc., and lets the LaTeX system handle the formatting and layout of these structures. As a result, it encourages the separation of the layout from the content — while still allowing manual typesetting adjustments whenever needed. This concept is similar to the mechanism by which many word processors allow styles to be defined globally for an entire document, or the use of Cascading Style Sheets in styling HTML documents. The LaTeX system is a markup language that handles typesetting and rendering, and can be arbitrarily extended by using the underlying macro language to develop custom macros such as new environments and commands. Such macros are often collected into packages, which could then be made available to address some specific typesetting needs such as the formatting of complex mathematical expressions or graphics (e.g., the use of the align environment provided by the amsmath package to produce aligned equations). In order to create a document in LaTeX, you first write a file, say document.tex, using your preferred text editor. Then you give your document.tex file as input to the TeX program (with the LaTeX macros loaded), which prompts TeX to write out a file suitable for onscreen viewing or printing. This write-format-preview cycle is one of the chief ways in which working with LaTeX differs from the What-You-See-Is-What-You-Get (WYSIWYG) style of document editing. It is similar to the code-compile-execute cycle known to computer programmers. Today, many LaTeX-aware editing programs make this cycle a simple matter through the pressing of a single key, while showing the output preview on the screen beside the input window. Some online LaTeX editors even automatically refresh the preview, while other online tools provide incremental editing in-place, mixed in with the preview in a streamlined single window. How it works The example below shows the input to LaTeX and the corresponding output from the system: Note how the equation for (highlighted in the example code) was typeset by the markup: E &= \frac{mc^2}{\sqrt{1-\frac{v^2}{c^2}}} where the square root is denoted by "\sqrt{argument}", and the fractions by "\frac{numerator}{denominator}". Pronouncing and writing "LaTeX" The characters 'T', 'E', and 'X' in the name come from the Greek capital letters tau, epsilon, and chi, as the name of TeX derives from the ('skill', 'art', 'technique'); for this reason, TeX's creator Donald Knuth promotes its pronunciation as () (that is, with a voiceless velar fricative as in Modern Greek, similar to the ch in loch). Lamport remarks that "TeX is usually pronounced tech, making lah-tech, lah-tech, and lay-tech the logical choices; but language is not always logical, so lay-tecks is also possible." The name is traditionally printed in running text with a special typographical logo: . In media where the logo cannot be precisely reproduced in running text, the word is typically given the unique capitalization LaTeX. Alternatively, the TeX, LaTeX and XeTeX logos can also be rendered via pure CSS and XHTML for use in graphical web browsers — by following the specifications of the internal \LaTeX macro. Related software As a macro package, LaTeX provides a set of macros for TeX to interpret. There are many other macro packages for TeX, including Plain TeX, GNU Texinfo, AMSTeX, and ConTeXt. When TeX "compiles" a document, it follows (from the user's point of view) the following processing sequence: Macros → TeX → Driver → Output. Different implementations of each of these steps are typically available in TeX distributions. Traditional TeX will output a DVI file, which is usually converted to a PostScript file. More recently, Hàn Thế Thành and others have written a new implementation of TeX called pdfTeX, which also outputs to PDF and takes advantage of features available in that format. The XeTeX engine developed by Jonathan Kew, on the other hand, merges modern font technologies and Unicode with TeX. The default font for LaTeX is Knuth's Computer Modern, which gives default documents created with LaTeX the same distinctive look as those created with plain TeX. XeTeX allows the use of OpenType and TrueType (that is, outlined) fonts for output files. There are also many editors for LaTeX, some of which are offline, source-code-based while others are online, partial-WYSIWYG-based. For more, see Comparison of TeX editors. Compatibility and converters LaTeX documents (.tex) can be opened with any text editor. They consist of plain text and do not contain hidden formatting codes or binary instructions. Additionally, TeX documents can be shared by rendering the LaTeX file to Rich Text Format (.rtf), XML, or the container format. This can be done using the free software programs LaTeX2RTF or TeX4ht. LaTeX can also be rendered to PDF files using the LaTeX extension pdfLaTeX. LaTeX files containing Unicode text can be processed into PDFs with the inputenc package, or by the TeX extensions XeLaTeX and LuaLaTeX. HeVeA is a converter written in Ocaml that converts LaTeX documents to HTML5. It is licensed under the Q Public License. LaTeX2HTML is a converter written in Perl that converts LaTeX documents to HTML. This way, e.g., scientific papers—primarily typeset for printing—can be placed on the Web for online viewing. It is licensed under GNU GPL v2. The latest updates are available from CTAN. LaTeXML is a free, public domain software, written in Perl, which converts LaTeX documents to a variety of structured formats, including HTML5 (with MathML), epub (encapsulation of HTML), jats, tei. Pandoc is a 'universal document converter' able to transform LaTeX into many different file formats, including HTML5, epub, rtf and docx. It is licensed under GNU GPL v2. LaTeX has become the de facto standard to typeset mathematical expression in scientific documents. Hence, there are several conversion tools focusing on mathematical LaTeX expressions, such as converters to MathML or Computer Algebra System. MathJax is a JavaScript library for converting LaTeX to MathML, picture formats, or HTML. The Wikimedia foundation uses it to build Mathoid, a web-service converter using Node.js that converts math inputs, such as LaTeX, to MathML and picture formats, including SVG and PNG. Mathoid is used in Wikipedia to render math. KaTeX is a JavaScript library for converting LaTeX to HTML and MathML. It is developed by the Khan Academy, and is among the fastest LaTeX to HTML converters. Licensing LaTeX is typically distributed along with plain TeX under a free software license: the LaTeX Project Public License (LPPL). The LPPL is not compatible with the GNU General Public License, as it requires that modified files must be clearly differentiable from their originals (usually by changing the filename); this was done to ensure that files that depend on other files will produce the expected behavior and avoid dependency hell. The LPPL is DFSG compliant as of version 1.3. As free software, LaTeX is available on most operating systems, which include UNIX (Solaris, HP-UX, AIX), BSD (FreeBSD, macOS, NetBSD, OpenBSD), Linux (Red Hat, Debian, Arch, Gentoo), Windows, DOS, RISC OS, AmigaOS and Plan9. Versions LaTeX2e is the current version of LaTeX, since it replaced LaTeX 2.09 in 1994. , LaTeX3, which started in the early 1990s, is under a long-term development project. Planned features include improved syntax (separation of content from styling), hyperlink support, a new user interface, access to arbitrary fonts and a new documentation. Some LaTeX3 features are available in LaTeX2e using packages, and by 2020 many features have been enabled in LaTeX2e by default for a gradual transition. There are numerous commercial implementations of the entire TeX system. System vendors may add extra features like additional typefaces and telephone support. LyX is a free, WYSIWYM visual document processor that uses LaTeX for a back-end. TeXmacs is a free, WYSIWYG editor with similar functionalities as LaTeX, but with a different typesetting engine. Other WYSIWYG editors that produce LaTeX include Scientific Word on Windows, and BaKoMa TeX on Windows, Mac and Linux. A number of community-supported TeX distributions are available. History LaTeX was created in the early 1980s by Leslie Lamport, when he was working at SRI. He needed to write TeX macros for his own use, and thought that with a little extra effort he could make a general package usable by others. Peter Gordon, an editor at Addison-Wesley, convinced him to write a LaTeX user's manual for publication (Lamport was initially skeptical that anyone would pay money for it); it came out in 1986 and sold hundreds of thousands of copies. Meanwhile, Lamport released versions of his LaTeX macros in 1984 and 1985. On 21 August 1989, at a TeX Users Group (TUG) meeting at Stanford, Lamport agreed to turn over maintenance and development of LaTeX to Frank Mittelbach. Mittelbach, along with Chris Rowley and Rainer Schöpf, formed the LaTeX3 team; in 1994, they released LaTeX2e, the current standard version, and continue working on LaTeX3. See also BibTeX – reference management software typically used with LaTeX Formula editor Help:Displaying a formula List of document markup languages List of TeX extensions xdvi – software for viewing DVI files while using Unix Notes References Further reading External links 1983 software Declarative markup languages Free TeX software Free text editors Free typesetting software Typesetting Open formats Software using the LPPL license SRI International software Formula editors	[ 0.2690158486366272, 0.050269465893507004, 0.032591890543699265, 0.3607127368450165, 0.23534221947193146, -0.03812573850154877, -0.3087694048881531, 0.4293777644634247, 0.06335052847862244, -0.4902149736881256, -0.6528568863868713, 0.5343720316886902, 0.012515424750745296, 0.014236657880246...
18196	https://en.wikipedia.org/wiki/List%20of%20saints	List of saints	This sortable list of Christian saints includes—where known—a surname, location, and personal attribute (or those attributes included as part of the historical name). Listed Canonized Roman Catholic saints have been through a formal institutional process resulting in their canonization. There have been thousands of canonizations. (Pope John Paul II alone canonized 110 individuals, as well as many group canonizations such as 110 martyr saints of China, 103 Korean martyrs, 117 Vietnamese martyrs, the Mexican Martyrs, Spanish martyrs and French revolutionary martyrs. Note that 78 popes are considered saints.) Among the Eastern Orthodox and Oriental Orthodox Communions, the numbers may be even higher, since there is no fixed process of "canonization" and each individual jurisdiction within the two Orthodox communions independently maintains parallel lists of saints that have only partial overlap. The Anglican Communion recognizes pre-Reformation saints, as does the United Methodist Church. Persons who have led lives of celebrated sanctity or missionary zeal are included in the Calendar of the Prayer Book "...without thereby enrolling or commending such persons as saints of the Church..." Similarly, any individuals commemorated in the Lutheran calendar of saints will be listed. Other denominations have their own Calendars of Saints they maintain. Christian saints since AD 300 Notes on saints list 4 Common Worship has "Commemoration". 6 Eastern Rite Catholic Churches only. 7 Russian Orthodox Church only. 8 9 Ukrainian Orthodox Church. Catholic known canonizations See also Calendar of saints Calendar of saints (Church of England) Calendar of saints (Episcopal Church) Calendar of saints (Anglican Church of Southern Africa) Calendar of saints (Lutheran) Coptic Orthodox calendar of saints Chronological list of saints and blesseds Doctor of the church Martyrology On the Resting-Places of the Saints (list from 11th century England) Patron saint Roman Martyrology Saint symbology Saints in Anglicanism Saints in Methodism Additional Lists: List of blesseds List of Catholic saints List of Coptic saints List of early Christian saints List of patron saints by occupation and activity List of saints of India List of Russian saints List of saints by pope List of saints of Ireland List of saints of the Society of Jesus List of servants of God (Roman Catholic Church) List of venerable people (Roman Catholic) List of venerable people (Eastern Orthodox) References Further reading Canonizations before 1588. Retrieved 2008-05-15. External links Extensive categorized lists of Catholic Saints Hagiographies, hymnography, and icons for many Orthodox saints from the website of the Orthodox Church in America. Canonizations 1982–2010 Hagiography Circle	[ -0.06776130199432373, 0.9844213128089905, -0.36659297347068787, -0.2500747740268707, -0.31910789012908936, 0.48108071088790894, 1.356073021888733, 0.4188801348209381, -1.1190177202224731, -0.25219419598579407, -0.07200169563293457, 0.10769373178482056, -0.04283991828560829, 0.3830904364585...
18198	https://en.wikipedia.org/wiki/Lebesgue%20measure	Lebesgue measure	In measure theory, a branch of mathematics, the Lebesgue measure, named after French mathematician Henri Lebesgue, is the standard way of assigning a measure to subsets of n-dimensional Euclidean space. For n = 1, 2, or 3, it coincides with the standard measure of length, area, or volume. In general, it is also called n-dimensional volume, n''-volume, or simply volume. It is used throughout real analysis, in particular to define Lebesgue integration. Sets that can be assigned a Lebesgue measure are called Lebesgue-measurable; the measure of the Lebesgue-measurable set A is here denoted by λ(A). Henri Lebesgue described this measure in the year 1901, followed the next year by his description of the Lebesgue integral. Both were published as part of his dissertation in 1902. The Lebesgue measure is often denoted by dx, but this should not be confused with the distinct notion of a volume form. Definition For any interval (or ) in the set of real numbers, let denote its length. For any subset , the Lebesgue outer measure is defined as an infimum Some sets satisfy the Carathéodory criterion, which requires that for every , The set of all such forms a σ-algebra. For any such , its Lebesgue measure is defined to be its Lebesgue outer measure: . A set that does not satisfy the Carathéodory criterion is not Lebesgue-measurable. Non-measurable sets do exist; an example is the Vitali sets. Intuition The first part of the definition states that the subset of the real numbers is reduced to its outer measure by coverage by sets of open intervals. Each of these sets of intervals covers in a sense, since the union of these intervals contains . The total length of any covering interval set may overestimate the measure of because is a subset of the union of the intervals, and so the intervals may include points which are not in . The Lebesgue outer measure emerges as the greatest lower bound (infimum) of the lengths from among all possible such sets. Intuitively, it is the total length of those interval sets which fit most tightly and do not overlap. That characterizes the Lebesgue outer measure. Whether this outer measure translates to the Lebesgue measure proper depends on an additional condition. This condition is tested by taking subsets of the real numbers using as an instrument to split into two partitions: the part of which intersects with and the remaining part of which is not in : the set difference of and . These partitions of are subject to the outer measure. If for all possible such subsets of the real numbers, the partitions of cut apart by have outer measures whose sum is the outer measure of , then the outer Lebesgue measure of gives its Lebesgue measure. Intuitively, this condition means that the set must not have some curious properties which causes a discrepancy in the measure of another set when is used as a "mask" to "clip" that set, hinting at the existence of sets for which the Lebesgue outer measure does not give the Lebesgue measure. (Such sets are, in fact, not Lebesgue-measurable.) Examples Any closed interval of real numbers is Lebesgue-measurable, and its Lebesgue measure is the length . The open interval has the same measure, since the difference between the two sets consists only of the end points a and b and has measure zero. Any Cartesian product of intervals and is Lebesgue-measurable, and its Lebesgue measure is , the area of the corresponding rectangle. Moreover, every Borel set is Lebesgue-measurable. However, there are Lebesgue-measurable sets which are not Borel sets. Any countable set of real numbers has Lebesgue measure 0. In particular, the Lebesgue measure of the set of algebraic numbers is 0, even though the set is dense in R. The Cantor set and the set of Liouville numbers are examples of uncountable sets that have Lebesgue measure 0. If the axiom of determinacy holds then all sets of reals are Lebesgue-measurable. Determinacy is however not compatible with the axiom of choice. Vitali sets are examples of sets that are not measurable with respect to the Lebesgue measure. Their existence relies on the axiom of choice. Osgood curves are simple plane curves with positive Lebesgue measure (it can be obtained by small variation of the Peano curve construction). The dragon curve is another unusual example. Any line in , for , has a zero Lebesgue measure. In general, every proper hyperplane has a zero Lebesgue measure in its ambient space. Properties The Lebesgue measure on Rn has the following properties: If A is a cartesian product of intervals I1 × I2 × ⋯ × In, then A is Lebesgue-measurable and If A is a disjoint union of countably many disjoint Lebesgue-measurable sets, then A is itself Lebesgue-measurable and λ(A) is equal to the sum (or infinite series) of the measures of the involved measurable sets. If A is Lebesgue-measurable, then so is its complement. λ(A) ≥ 0 for every Lebesgue-measurable set A. If A and B are Lebesgue-measurable and A is a subset of B, then λ(A) ≤ λ(B). (A consequence of 2.) Countable unions and intersections of Lebesgue-measurable sets are Lebesgue-measurable. (Not a consequence of 2 and 3, because a family of sets that is closed under complements and disjoint countable unions does not need to be closed under countable unions: .) If A is an open or closed subset of Rn (or even Borel set, see metric space), then A is Lebesgue-measurable. If A is a Lebesgue-measurable set, then it is "approximately open" and "approximately closed" in the sense of Lebesgue measure (see the regularity theorem for Lebesgue measure). A Lebesgue-measurable set can be "squeezed" between a containing open set and a contained closed set. This property has been used as an alternative definition of Lebesgue measurability. More precisely, is Lebesgue-measurable if and only if for every there exist an open set and a closed set such that and . A Lebesgue-measurable set can be "squeezed" between a containing Gδ set and a contained Fσ. I.e, if A is Lebesgue-measurable then there exist a Gδ set G and an Fσ F such that G ⊇ A ⊇ F and λ(G \ A) = λ(A \ F) = 0. Lebesgue measure is both locally finite and inner regular, and so it is a Radon measure. Lebesgue measure is strictly positive on non-empty open sets, and so its support is the whole of Rn. If A is a Lebesgue-measurable set with λ(A) = 0 (a null set), then every subset of A is also a null set. A fortiori, every subset of A is measurable. If A is Lebesgue-measurable and x is an element of Rn, then the translation of A by x, defined by A + x = {a + x : a ∈ A}, is also Lebesgue-measurable and has the same measure as A. If A is Lebesgue-measurable and , then the dilation of by defined by is also Lebesgue-measurable and has measure More generally, if T is a linear transformation and A is a measurable subset of Rn, then T(A) is also Lebesgue-measurable and has the measure . All the above may be succinctly summarized as follows (although the last two assertions are non-trivially linked to the following): The Lebesgue-measurable sets form a σ-algebra containing all products of intervals, and λ is the unique complete translation-invariant measure on that σ-algebra with The Lebesgue measure also has the property of being σ-finite. Null sets A subset of Rn is a null set if, for every ε > 0, it can be covered with countably many products of n intervals whose total volume is at most ε. All countable sets are null sets. If a subset of Rn has Hausdorff dimension less than n then it is a null set with respect to n-dimensional Lebesgue measure. Here Hausdorff dimension is relative to the Euclidean metric on Rn (or any metric Lipschitz equivalent to it). On the other hand, a set may have topological dimension less than n and have positive n-dimensional Lebesgue measure. An example of this is the Smith–Volterra–Cantor set which has topological dimension 0 yet has positive 1-dimensional Lebesgue measure. In order to show that a given set A is Lebesgue-measurable, one usually tries to find a "nicer" set B which differs from A only by a null set (in the sense that the symmetric difference (A − B) ∪ (B − A) is a null set) and then show that B can be generated using countable unions and intersections from open or closed sets. Construction of the Lebesgue measure The modern construction of the Lebesgue measure is an application of Carathéodory's extension theorem. It proceeds as follows. Fix . A box in Rn is a set of the form where , and the product symbol here represents a Cartesian product. The volume of this box is defined to be For any subset A of Rn, we can define its outer measure λ*(A) by: We then define the set A to be Lebesgue-measurable if for every subset S of Rn, These Lebesgue-measurable sets form a σ-algebra, and the Lebesgue measure is defined by for any Lebesgue-measurable set A. The existence of sets that are not Lebesgue-measurable is a consequence of the set-theoretical axiom of choice, which is independent from many of the conventional systems of axioms for set theory. The Vitali theorem, which follows from the axiom, states that there exist subsets of R that are not Lebesgue-measurable. Assuming the axiom of choice, non-measurable sets with many surprising properties have been demonstrated, such as those of the Banach–Tarski paradox. In 1970, Robert M. Solovay showed that the existence of sets that are not Lebesgue-measurable is not provable within the framework of Zermelo–Fraenkel set theory in the absence of the axiom of choice (see Solovay's model). Relation to other measures The Borel measure agrees with the Lebesgue measure on those sets for which it is defined; however, there are many more Lebesgue-measurable sets than there are Borel measurable sets. The Borel measure is translation-invariant, but not complete. The Haar measure can be defined on any locally compact group and is a generalization of the Lebesgue measure (Rn with addition is a locally compact group). The Hausdorff measure is a generalization of the Lebesgue measure that is useful for measuring the subsets of Rn of lower dimensions than n, like submanifolds, for example, surfaces or curves in R3 and fractal sets. The Hausdorff measure is not to be confused with the notion of Hausdorff dimension. It can be shown that there is no infinite-dimensional analogue of Lebesgue measure. See also Lebesgue's density theorem Lebesgue measure of the set of Liouville numbers Non-measurable set Vitali set References Measures (measure theory)	[ -0.34389370679855347, -0.28528326749801636, -0.4066314995288849, -0.08440548181533813, -0.22227028012275696, 0.41695672273635864, -0.16390866041183472, -0.38329946994781494, -0.18963754177093506, -0.9175105094909668, -0.5864373445510864, 0.06616026908159256, -0.36536905169487, 0.4018053412...
18201	https://en.wikipedia.org/wiki/Lake%20Champlain	Lake Champlain	Lake Champlain ( ; ; Abenaki: Pitawbagw ["At Lake Champlain" (loc.):Pitawbagok] ; ) is a natural freshwater lake in North America mainly within the borders of the United States (in the states of Vermont and New York) but also across the Canada–U.S. border into the Canadian province of Quebec. The New York portion of the Champlain Valley includes the eastern portions of Clinton County and Essex County. Most of this area is part of the Adirondack Park. There are recreational facilities in the park and along the relatively undeveloped coastline of Lake Champlain. The cities of Plattsburgh, New York and Burlington, Vermont are on the lake's western and eastern shores, respectively, and the Town of Ticonderoga, New York is in the region's southern part. The Quebec portion is in the regional county municipalities of Le Haut-Richelieu and Brome-Missisquoi. There are a number of islands in the lake; the largest include Grand Isle, Isle La Motte and North Hero: all part of Grand Isle County, Vermont. Because of both Lake Champlain's connection to the St. Lawrence Seaway via the Richelieu River and the existence of the Champlain Canal, Lake Champlain is sometimes referred to as "The Sixth Great Lake." Geology The Champlain Valley is the northernmost unit of a landform system known as the Great Appalachian Valley, which stretches between Quebec, Canada, to the north, and Alabama, US, to the south. The Champlain Valley is a physiographic section of the larger Saint Lawrence Valley, which in turn is part of the larger Appalachian physiographic division. Lake Champlain is one of numerous large lakes scattered in an arc through Labrador, in Canada, the northern United States, and the Northwest Territories of Canada. It is the thirteenth-largest lake by area in the US. Approximately in area, the lake is long and across at its widest point, and has a maximum depth of approximately . The lake varies seasonally from about above mean sea level. Lake Champlain has been described as the sixth-largest lake in the United States. Hydrology Lake Champlain is in the Lake Champlain Valley between the Green Mountains of Vermont and the Adirondack Mountains of New York, drained northward by the Richelieu River into the St. Lawrence River at Sorel-Tracy, Quebec, northeast and downstream of Montreal, Quebec. It also receives the waters from the Lake George, so its basin collects waters from the northwestern slopes of the Green Mountains and the northernmost eastern peaks of the Adirondack Mountains. Lake Champlain drains nearly half of Vermont, and approximately 250,000 people get their drinking water from the lake. The lake is fed in Vermont by the LaPlatte, Lamoille, Missisquoi, Poultney and Winooski rivers, along with Lewis Creek, Little Otter Creek and Otter Creek. In New York, it is fed by the Ausable, Boquet, Great Chazy, La Chute, Little Ausable, Little Chazy, Salmon and Saranac rivers, along with Putnam Creek. In Quebec, it is fed by the Pike River. It is connected to the Hudson River by the Champlain Canal. Parts of the lake freeze each winter, and in some winters the entire lake surface freezes, referred to as "closing". In July and August, the lake temperature reaches an average of . Chazy Reef The Chazy Reef is an extensive Ordovician carbonate rock formation that extends from Tennessee to Quebec and Newfoundland. The oldest reefs are around "The Head" of the south end of Isle La Motte; slightly-younger reefs are found at the Fisk Quarry, and the youngest (the famous coral reefs) are in fields to the north. History The lake has long acted as a border between indigenous nations, much as it is today between the states of New York and Vermont. The lake is located at the frontier between Abenaki and Mohawk (Iroquois Confederacy) traditional territories. The official toponym for the lake, according to the orthography established by the Grand Council of Wanab-aki Nation, is Pitawbagok (alternative orthographies include Petonbowk and Bitawbagok), meaning 'middle lake', 'lake in between' or 'double lake'. The Mohawk name in modern orthography, as standardized in 1993, is Kaniatarakwà:ronte, meaning "a bulged lake" or "lake with a bulge in it". An alternate name is Kaniá:tare tsi kahnhokà:ronte (phonetic English spelling Caniaderi Guarunte), meaning 'door of the country' or 'lake to the country'. The lake is an important eastern gateway to Iroquois Confederacy lands. The lake was named after the French explorer Samuel de Champlain, who encountered it in July, 1609. While the ports of Burlington, Vermont, Port Henry, New York and Plattsburgh, New York today are primarily used by small craft, ferries and lake cruise ships, they were of substantial commercial and military importance in the 18th and 19th centuries. Colonial America and the Revolutionary War New France allocated concessions all along lake Champlain to French settlers and built forts to defend the waterways. In colonial times, Lake Champlain was used as a water (or, in winter, ice) passage between the Saint Lawrence and Hudson valleys. Travelers found it easier to journey by boats and sledges on the lake rather than go overland on unpaved and frequently mud-bound roads. The lake's northern tip at Saint-Jean-sur-Richelieu, Quebec (known as St. John in colonial times under British rule) is a short distance from Montreal, Quebec. The southern tip at Whitehall (Skenesborough in revolutionary times) is a short distance from Saratoga, Glens Falls and Albany, New York. Forts were built at Ticonderoga and Crown Point (Fort St. Frederic) to control passage on the lake in colonial times. Important battles were fought at Ticonderoga in 1758 and 1775. During the Revolutionary War, the British and Americans conducted a frenetic shipbuilding race through the spring and summer of 1776, at opposite ends of the lake, and fought a significant naval engagement on October 11 at the Battle of Valcour Island. While it was a tactical defeat for the Americans, and the small fleet led by Benedict Arnold was almost destroyed, the Americans gained a strategic victory; the British invasion was delayed long enough so the approach of winter prevented the fall of these forts until the following year. In this period, the Continental Army gained strength and was victorious at Saratoga. Beginning of the Revolutionary War At the start of the Revolutionary War, British forces occupied the Champlain Valley. However, it did not take long for rebel leaders to realize the importance of controlling Lake Champlain. Early in the war, the colonial militias attempted to expel the British from Boston; however, this undertaking could not be achieved without heavy artillery. The British forts at Ticonderoga and Crown Point, on Lake Champlain, were known to have ample supplies of artillery and were weakly-manned by the British. Thus, the colonial militias devised a plan to take control of the two forts and bring the guns back to the fight in Boston. The necessity of controlling the two forts at Ticonderoga and Crown Point placed Lake Champlain as a strategic arena during the Revolutionary War. By taking control of these forts, Americans not only gained heavy artillery, but control of a vast water highway as well: Lake Champlain provided a direct invasion route to British Canada. However, had the British controlled the lake, they could have divided the colonies of New England and further depleted the Continental Army. The Continental Army's first offensive action took place in May 1775, three weeks after the Battles of Lexington and Concord. Ethan Allen, accompanied by 200 Green Mountain Boys, was ordered to capture Fort Ticonderoga and retrieve supplies for the fight in Boston. Benedict Arnold shared the command with Allen, and, in early May 1775, they captured Fort Ticonderoga, Crown Point and the southern Loyalist settlement of Skenesborough. As a result of Allen's offensive attack on the Champlain Valley in 1775, the American forces controlled the Lake Champlain waterway. Siege of Quebec: 1775–1776 The Continental Army realized the strategic advantage of controlling Lake Champlain, as it leads directly to the heart of Quebec. Immediately after taking Forts Ticonderoga and Crown Point, the Americans began planning an attack on British Canada. The American siege of Quebec was a two-pronged assault and occurred throughout the winter of 1775–1776. Brigadier General Richard Montgomery led the first assault up the Champlain Valley into Canada, while Benedict Arnold led a second army to Quebec via the Maine wilderness. Despite the strategic advantage of controlling a direct route to Quebec by way of the Champlain Valley, the American siege of British Canada during the winter of 1775 failed. The Continental Army mistakenly assumed that it would receive support from the Canadians upon their arrival at Quebec. This was not the case, and the rebel army struggled to take Quebec with diminishing supplies, support, and harsh northern winter weather. The Continental Army was forced to camp outside Quebec's walls for the winter, with reinforcements from New York, Pennsylvania, Massachusetts, New Hampshire and Connecticut allowing the soldiers to maintain their siege of the city. The reinforcements traveled hundreds of miles (kilometres) up the frozen Lake Champlain and St. Lawrence River, but were too late and too few to influence a successful siege of Quebec. In May 1776, with the arrival of a British convoy carrying 10,000 British and Hessian troops to Canada, the Continental forces retreated back down the Champlain Valley to reevaluate their strategy. "I know of no better method than to secure the important posts of Ticonderoga and Crown Point, and by building a number of armed vessels to command the lakes, otherwise the forces now in Canada will be brought down upon us as quick as possible, having nothing to oppose them...They will doubtless try to construct some armed vessels and then endeavor to penetrate the country toward New York." (Brigadier General John Sullivan to George Washington, June 24, 1776). Both British and American forces spent the summer of 1776 building their naval fleets, at opposite ends of Lake Champlain. By the October 1776, the Continental Army had 16 operating naval vessels on Lake Champlain: a great increase to the four small ships they had at the beginning of the summer. General Benedict Arnold commanded the American naval fleet on Lake Champlain, which was composed of volunteers and soldiers drafted from the Northern Army. With great contrast to the Continental navy, experienced Royal Navy officers, British seamen and Hessian artillerymen manned the British fleet on Lake Champlain. By the end of the summer of 1776, the opposing armies were prepared to battle over the strategic advantage of controlling Lake Champlain. Battle of Valcour Island On October 11, 1776, the British and American naval fleets met on the western side of Valcour Island, on Lake Champlain. American General Benedict Arnold established the location, as it provided the Continental fleet with a natural defensive position. The British and American vessels engaged in combat for much of the day, only stopping due to impending nightfall. After a long day of combat, the American fleet was in worse shape than the experienced British Navy. Upon ceasefire, Arnold called a council of war with his fellow officers, proposing to escape the British fleet via rowboats under the cover of night. As the British burned Arnold's flagship, the Royal Savage, to the east, the Americans rowed past the British lines. The following morning, the British learned of the Americans' escape and set out after the fleeing Continental vessels. On October 13, the British fleet caught up to the struggling American ships near Split Rock Mountain. With no hope of fighting off the powerful British navy, Arnold ordered his men to run their five vessels aground in Ferris Bay, Panton, Vermont. The depleted Continental army escaped on land back to Fort Ticonderoga and Mount Independence; however, they no longer controlled the Lake Champlain waterway. The approaching winter of 1776–1777 restricted British movement along the recently-controlled Lake Champlain. As the British abandoned Crown Point and returned to Canada for the winter, the Americans reduced their garrisons in the Champlain Valley from 13,000 to 2,500 soldiers. General Burgoyne’s Campaign In early 1777, British General John Burgoyne led 8,000 troops from Canada, down Lake Champlain and into the Champlain Valley. The goal of this invasion was to divide the New England colonies, thus forcing the Continental Army into a separated fight on multiple fronts. Lake Champlain provided Burgoyne with protected passage deep into the American colonies. Burgoyne's army reached Fort Ticonderoga and Mount Independence in late June, 1777. During the night of July 5, the American forces fled Ticonderoga as the British took control of the fort. However, Burgoyne's southern campaign did not go uncontested. On October 7, 1777, American General Horatio Gates, who occupied Bemis Heights, met Burgoyne's army at the Second Battle of Freeman's Farm. At Freeman's Farm, Burgoyne's army suffered its final defeat and ended its invasion south into the colonies. Ten days later, on October 17, 1777, British General Burgoyne surrendered his army at Saratoga. This defeat was instrumental to the momentum of the Revolutionary War, as the defeat of the British army along the Champlain-Hudson waterway convinced France to ally with the American army. Aftermath of 1777 Following the failed British campaign led by General Burgoyne, the British still maintained control over the Champlain waterway for the duration of the Revolutionary War. The British used the Champlain waterway to supply raids across the Champlain Valley from 1778 to 1780, and Lake Champlain permitted direct transportation of supplies from the British posts at the northern end of the lake. With the end of the Revolutionary War in 1783, the British naval fleet on Lake Champlain retreated up to St. John's. However, British troops garrisoned at Fort Dutchman's Point (North Hero, Vermont) and Fort au Fer (Champlain, New York), on Lake Champlain, did not leave until the 1796 Jay Treaty. Post-Revolutionary War period Eager to take back control of Lake Champlain following the end of the Revolutionary War, Americans flocked to settle the Champlain Valley. Many individuals emigrated from Massachusetts and other New England colonies, such as Salmon Dutton, a settler of Cavendish, Vermont. Dutton emigrated in 1782 and worked as a surveyor, town official and toll-road owner. His home had a dooryard garden, typical of mid-19th century New England village homes, and his experience settling in the Champlain Valley depicts the industries and lifestyles surrounding Lake Champlain following the Revolutionary War. Similar to the experience of Salmon Dutton, former colonial militia Captain Hezekiah Barnes settled in Charlotte, Vermont in 1787. Following the war, Barnes also worked as a road surveyor; he also established an inn and trading post in Charlotte, along the main trade route from Montreal down Lake Champlain. Barnes' stagecoach inn was built in traditional Georgian style, with 10 fireplaces, a ballroom on the interior and a wraparound porch on the outside. In 1800, Continental Army Captain Benjamin Harrington established a distillery business in Shelburne, Vermont, which supplied his nearby inn. Furthermore, Captain Stevens and Jeremiah Trescott built a water-powered sawmill in South Royalton, Vermont in the late 1700s. These individual accounts shed light on the significance of Lake Champlain during the post-Revolutionary War period. War of 1812 During the War of 1812, British and American forces faced each other in the Battle of Lake Champlain, also known as the Battle of Plattsburgh, fought on September 11, 1814. This ended the final British invasion of the northern states during the War of 1812. It was fought just prior to the signing of the Treaty of Ghent, and the American victory denied the British any leverage to demand exclusive control over the Great Lakes or territorial gains against the New England states. Three US Naval ships have been named after this battle: , and a cargo ship used during World War I. Following the War of 1812, the U.S. Army began construction on "Fort Blunder": an unnamed fortification built at the northernmost end of Lake Champlain to protect against attacks from British Canada. Its nickname came from a surveying error: the initial phase of construction on the fort turned out to be taking place on a point north of the Canada–U.S. border. Once this error was spotted, construction was abandoned. Locals scavenged materials used in the abandoned fort for use in their homes and public buildings. By the Webster-Ashburton Treaty of 1842, the Canada–U.S. border was adjusted northward to include the strategically-important site of "Fort Blunder" on the US side. In 1844, work was begun to replace the remains of the 1812-era fort with a massive new Third System masonry fortification, known as Fort Montgomery. Portions of this fort are still standing. Modern history In the early 19th century, the construction of the Champlain Canal connected Lake Champlain to the Hudson River system, allowing north–south commerce by water from New York City to Montreal and Atlantic Canada. In 1909, 65,000 people celebrated the 300th anniversary of the French discovery of the lake. Attending dignitaries included President William Howard Taft, along with representatives from France, Canada and the United Kingdom. In 1929, then-New York Governor Franklin Roosevelt and Vermont Governor John Weeks dedicated the first bridge to span the lake, built from Crown Point to Chimney Point. This bridge lasted until December, 2009. Severe deterioration was found, and the bridge was demolished and replaced with the Lake Champlain Bridge, which opened in November, 2011. On February 19, 1932, boats were able to sail on Lake Champlain. It was the first time that the lake was known to be free of ice during the winter at that time. Lake Champlain briefly became the nation's sixth Great Lake on March 6, 1998, when President Clinton signed Senate Bill 927. This bill, which was led by U.S. Senator Patrick Leahy of Vermont and reauthorized the National Sea Grant Program, contained a line declaring Lake Champlain to be a Great Lake. This status enabled its neighboring states to apply for additional federal research and education funds allocated to these national resources. However, following a small uproar, the Great Lake status was rescinded on March 24 (although New York and Vermont universities continue to receive funds to monitor and study the lake). "Champ", Lake Champlain monster In 1609, Samuel de Champlain wrote that he saw a lake monster long, as thick as a man's thigh, with silver-gray scales a dagger could not penetrate. The alleged monster had jaws with sharp and dangerous teeth. Native Americans claimed to have seen similar monsters long. This mysterious creature is likely the original Lake Champlain monster. The monster has been memorialized in sports teams' names and mascots, i.e., the Vermont Lake Monsters and Champ, the mascot of the state's minor league baseball team. A Vermont Historical Society publication recounts the story and offers possible explanations for accounts of the so-called monster: "floating logs, schools of large sturgeon diving in a row, or flocks of blackbirds flying close to the water". Ecology A pollution prevention, control and restoration plan for Lake Champlain was first endorsed in October, 1996 by the governors of New York and Vermont and the regional administrators of the United States Environmental Protection Agency (EPA). In April, 2003, the plan was updated, and Quebec signed-on to it. The plan is being implemented by the Lake Champlain Basin Program and its partners at the state, provincial, federal and local levels. Renowned as a model for interstate and international cooperation, its primary goals are to reduce phosphorus inputs to Lake Champlain, reduce toxic contamination, minimize the risks to humans from water-related health hazards and control the introduction, spread, and impact of non-native nuisance species to preserve the integrity of the Lake Champlain ecosystem. Senior staff who helped organize the Environmental Protection Agency in 1970 recall that International Paper was one of the first companies to call upon the brand-new agency, because it was being pressured by both New York and Vermont with regard to a discharge of pollution into Lake Champlain. Agricultural and urban runoff from the watershed or drainage basin is the primary source of excess phosphorus, which exacerbates algae blooms in Lake Champlain. The most problematic blooms have been cyanobacteria, commonly called blue-green algae, in the northeastern part of the Lake: primarily Missisquoi Bay. To reduce phosphorus runoff to this part of the lake, Vermont and Quebec agreed to reduce their inputs by 60% and 40%, respectively, by an agreement signed in 2002. While agricultural sources (manure and fertilizers) are the primary sources of phosphorus (about 70%) in the Missisquoi basin, runoff from developed land and suburbs is estimated to contribute about 46% of the phosphorus runoff basin-wide to Lake Champlain, and agricultural lands contributed about 38%. In 2002, the cleanup plan noted that the lake had the capacity to absorb of phosphorus each year. In 2009, a judge noted that were still flowing in annually: more than twice what the lake could handle. Sixty municipal and industrial sewage plants discharge processed waste from the Vermont side. In 2008, the EPA expressed concerns to the State of Vermont that the Lake's cleanup was not progressing fast enough to meet the original cleanup goal of 2016. The state, however, cites its Clean and Clear Action Plan as a model that will produce positive results for Lake Champlain. In 2007, Vermont banned phosphates for dishwasher use starting in 2010. This will prevent an estimated from flowing into the lake. While this represents 0.6% of the phosphate pollution, it took US$1.9 million to remove the pollutant from treated wastewater: an EPA requirement. Despite concerns about pollution, Lake Champlain is safe for swimming, fishing and boating. It is considered a world-class fishery for salmonid species (Lake trout and Atlantic salmon) and bass. About 81 fish species live in the lake, and more than 300 bird species rely on it for habitat and as a resource during migrations. By 2008, at least six institutions were monitoring lake water health: Conservation Law Foundation, which in 2002 appointed a "lakekeeper" who reviews the state's pollution controls Friends of Missisquoi Bay, formed in 2003 Lake Champlain Committee Vermont Water Resources Board, which hired a water quality expert in 2008 to write water quality standards and create wetland protection rules Vermont Agency of Natural Resources, which in 2007 appointed a "lake czar" to oversee pollution control Clean and Clear, an agency of the Vermont state government, established in 2004 Nature Conservancy, a non-profit group which focuses on biodiversity and ecosystem health. In 2001, scientists estimated that farming contributed 38% of the phosphorus runoff. By 2010, results of environmentally-conscious farming practices, enforced by law, had made a positive contribution to lake cleanliness. A federally-funded study was started to analyze this problem and to arrive at a solution. Biologists have been trying to control lampreys in the lake since 1985 or earlier. Lampreys are native to the area, but have expanded in population to such an extent that they wounded nearly all lake trout in 2006, and 70–80% of salmon. The use of pesticides against the lamprey has reduced their damage to other fish to 35% of salmon and 31% of lake trout. The goal was 15% of salmon and 25% of lake trout. The federal and state governments originally budgeted US$18 million for lake programs for 2010. This was later supplemented by an additional US$6.5 million from the federal government. Natural history In 2010, the estimate of cormorant population, now classified as a nuisance species because they take so much of the lake fish, ranged from 14,000 to 16,000. A Fish and Wildlife commissioner said that the ideal population would be about 3,300 . Cormorants had disappeared from the lake (and all northern lakes) due to the use of DDT in the 1940s and 1950s, which made their eggs more fragile and reduced breeding populations. Ring-billed gulls are also considered a nuisance, and measures have been taken to reduce their population. Authorities are trying to encourage the return of black crowned night herons, cattle egrets and great blue herons, which disappeared during the time DDT was being widely used. In 1989, UNESCO designated the area around Lake Champlain as the Champlain-Adirondack Biosphere Reserve. Infrastructure Lake crossings The Alburgh Peninsula (also known as the Alburgh Tongue), extending south from the Quebec shore of the lake into Vermont, and Province Point, the southernmost tip of a small promontory approximately in size a few miles (kilometres) to the northeast of the town of East Alburgh, Vermont, are connected by land to the rest of the state only via Canada. This is a distinction shared with the state of Alaska, Point Roberts, Washington and the Northwest Angle in Minnesota. All of these are practical exclaves of the United States contiguous with Canada. Unlike the other cases, highway bridges across the lake provide direct access to the Alburgh peninsula from within the United States (from three directions), but Province Point is still accessible by land only through Canada. Road Two roadways cross over the lake, connecting Vermont and New York: Since November 2011, the Lake Champlain Bridge has crossed the lake's southern part, connecting Chimney Point in Vermont with Crown Point, New York. It replaced Champlain Bridge, which was closed in 2009 because of severe structural problems that could have resulted in a collapse. In 2009, the bridge had been used by 3,400 drivers per day, and driving around the southern end of the lake added two hours to the trip. Ferry service was re-established to take some of the traffic burden. On December 28, 2009, the bridge was destroyed by a controlled demolition. A new bridge was rapidly constructed by a joint state commitment, opening on November 7, 2011. To the north, US 2 runs from Rouses Point, New York, to Grand Isle County, Vermont, in the town of Alburgh, before continuing south along a chain of islands toward Burlington. To the east, Vermont Route 78 runs from an intersection with US 2 in Alburgh through East Alburgh to Swanton. The US 2-VT 78 route technically runs from the New York mainland to an extension of the mainland between two arms of the lake and then to the Vermont mainland, but it provides a direct route across the two main arms of the lake's northern part. Ferry North of Ticonderoga, New York, the lake widens appreciably; ferry service is operated by the Lake Champlain Transportation Company at: Charlotte, Vermont, to Essex, New York (may not travel when the lake is frozen) Burlington, Vermont, to Port Kent, New York (seasonal) Grand Isle, Vermont, to Cumberland Head, part of Plattsburgh, New York (year-round icebreaking service) While the old bridge was being demolished and the new one constructed, Lake Champlain Transportation Company operated a free, 24-hour ferry from just south of the bridge to Chimney Point, Vermont, at the expense of the states of New York and Vermont, at a cost to the states of about $10 per car. The most southerly crossing is the Fort Ticonderoga Ferry, connecting Ticonderoga, New York with Shoreham, Vermont, just north of the historic fort. Railroad Four significant railroad crossings were built over the lake. As of 2021, only one remains. The "floating" rail trestle from Larabees Point, Vermont to Ticonderoga, New York was operated by the Addison Branch of the Rutland Railroad. It was abandoned in 1918, due to a number of accidents which resulted in locomotives and rail cars falling into the lake. The Island Line Causeway, a marble tailings and granite rock landfill causeway that stretched from Colchester (on the mainland) north and west to South Hero, Vermont. Two breaks in the causeway were spanned by a fixed iron trestle and a swing bridge that could be opened to allow boats to pass. The Rutland Railroad (later Rutland Railway) operated trains over this causeway from 1901–1961, with the last passenger train operated in 1953. The railroad was officially abandoned in 1963, with tracks and trestles removed over the course of the ten years that followed. The marble tailings and granite rock causeway still remains, as does the fixed iron trestle that bridges the lesser of the two gaps. The swing bridge over the navigation channel was removed in the early 1970s. Now called Colchester Park, the main three-mile (5 km) causeway has been adapted and preserved as a recreation area for cyclists, runners and anglers. Two smaller marble tailings and granite rock landfill causeways were also erected as part of this line that connected Grand Isle to North Hero, and spanned from North Hero to Alburgh. The Alburgh, Vermont – Rouses Point, New York rail trestle. From sometime in the late 19th century until 1964, this wooden trestle carried two railroads (the Rutland Railroad and the Central Vermont Railroad) over the lake just south of the US 2 vehicular bridge. The iron swing bridge at the center (over the navigation channel) has been removed. Most of the wooden pilings remain, greatly deteriorated, and can be seen looking south from the US 2 bridge. Part of the trestle on the Rouses Point side has been converted for use as an access pier associated with the local marina. The Swanton – Alburgh, Vermont rail trestle. Built in the same manner as at Rouses Point, it crosses the lake just south of Missisquoi Bay and the Canada–U.S. border, within yards south of the Vermont Route 78 bridge. It is still in use by the New England Central Railroad. Waterways Lake Champlain has been connected to the Erie Canal via the Champlain Canal since the canal's official opening on September 9, 1823: the same day as the opening of the Erie Canal from Rochester on Lake Ontario to Albany. It connects to the St. Lawrence River via the Richelieu River, with the Chambly Canal bypassing rapids on the river since 1843. Together with these waterways, the lake is part of the Lakes to Locks Passage. The Lake Champlain Seaway, a project to use the lake to bring ocean-going ships from New York City to Montreal, was proposed in the late 19th century and considered as late as the 1960s, but rejected for various reasons. The lake is also part of the 740-mile Northern Forest Canoe Trail, which begins in Old Forge, New York and ends in Fort Kent, Maine. Surroundings Major cities Burlington, Vermont (pop. 42,217, 2010 Census) is the largest city on the lake. The second and third most-populated cities/towns are Plattsburgh, New York and South Burlington, Vermont, respectively. The fourth-largest community is the town of Colchester. Islands Lake Champlain contains roughly 80 islands, three of which comprise four entire Vermont towns (most of Grand Isle County). The largest islands: South Hero Island, the largest, containing the towns of Grand Isle, Vermont and South Hero, Vermont North Hero Island, containing the town of North Hero, Vermont Isle La Motte, containing the town of Isle La Motte, Vermont Valcour Island, New York Juniper Island (Lake Champlain) Three Sisters Four Brothers Savage Island Burton Island (State Park) Cloak Island Garden Island (Gunboat Island) Crab Island, New York Dameas Island Hen Island Butler's Island Carleton's Prize Young Island Providence Island Stave Island Sunset Island Lighthouses Bluff Point Lighthouse, on Valcour Island near the New York shore, was built in 1871; it was manned by a full-time lightkeeper until 1930, making it one of the last lighthouses to be manned on the Lake Cumberland Head Light, which operated until 1934, is an historic stone lighthouse located on Cumberland Head which is privately-owned Isle La Motte Light, on the northern end of the island, was originally red, but faded to pink over time; it is privately owned Juniper Island Light is a cast-iron lighthouse that dates from 1846; in 1954, it was deactivated and replaced by a steel tower; it is privately owned On Point Au Roche, part of Beekmantown, New York, there is a privately-owned, historic lighthouse Split Rock Lighthouse is located south of Essex, New York, near a natural boundary of the territory between the Mohawk and Algonquin tribes Aids to navigation All active navigational aids on the American portion of the lake are maintained by USCG Burlington station, along with those on international Lake Memphremagog to the east. Aids to navigation on the Canadian portion of the lake are maintained by the Canadian Coast Guard. Parks There are a number of parks in the Lake Champlain region, in both New York and Vermont. Those on the New York side of the lake include: Point Au Roche State Park, which park grounds have hiking and cross country skiing trails and a public beach; and the Ausable Point State Park. The Cumberland Bay State Park is located on Cumberland Head, with a campground, city beach and sports fields. There are various parks along the lake on the Vermont side, including Sand Bar State Park in Milton, featuring a natural sand beach, swimming, canoe and kayak rentals, food concession, picnic grounds and a play area. At , Grand Isle State Park contains camping facilities, a sand volleyball court, a nature walk trail, a horseshoe pit and a play area. Button Bay State Park in Ferrisburgh features campsites, picnic areas, a nature center and a swimming pool. Burlington's Waterfront Park is a revitalized industrial area. Public safety Coast Guard Station Burlington provides "Search and Rescue, Law Enforcement and Ice Rescue services 24 hours a day, 365 days a year". Services are also provided by local, state and federal governments bordering on the lake, including the U.S. Border Patrol, Royal Canadian Mounted Police, Vermont State Police, New York State Police Marine Detail, and Vermont Fish and Wildlife wardens. See also Champlain Sea, post-glacial predecessor to Lake Champlain Île aux Noix List of lakes in Vermont List of New York rivers List of rivers of Quebec List of rivers in Vermont Odziozo References External links Bloom: the Plight of Lake Champlain (PBS film series) Champlain: The Lake Between Documentary produced by Vermont Public Television ECHO, Leahy Center for Lake Champlain Ethan Allen Homestead Museum Lake Champlain Community Sailing Center Lake Champlain Basin Atlas Lake Champlain Basin Program Lake Champlain Maritime Museum Lake Champlain Quadricentennial International flood study Shelburne Museum Lake Champlain United Lake Champlain International Biosphere reserves of the United States Borders of New York (state) Borders of Vermont Canada–United States border Champlain Champlain Champlain Champlain Champlain Champlain Champlain Champlain Champlain Champlain Champlain Champlain Champlain Tributaries of the Saint Lawrence River	[ -0.9612295031547546, 0.39214426279067993, -0.007697992492467165, 0.16119417548179626, -0.07641100883483887, 0.34705835580825806, 0.3410618007183075, 0.8939222097396851, -0.7094744443893433, -0.12589339911937714, -0.32734552025794983, 0.5334423184394836, -0.037911832332611084, 0.17885857820...
18203	https://en.wikipedia.org/wiki/Lambda%20calculus	Lambda calculus	Lambda calculus (also written as λ-calculus) is a formal system in mathematical logic for expressing computation based on function abstraction and application using variable binding and substitution. It is a universal model of computation that can be used to simulate any Turing machine. It was introduced by the mathematician Alonzo Church in the 1930s as part of his research into the foundations of mathematics. Lambda calculus consists of constructing lambda terms and performing reduction operations on them. In the simplest form of lambda calculus, terms are built using only the following rules: producing expressions such as: (λx.λy.(λz.(λx.z x) (λy.z y)) (x y)). Parentheses can be dropped if the expression is unambiguous. For some applications, terms for logical and mathematical constants and operations may be included. The reduction operations include: If De Bruijn indexing is used, then α-conversion is no longer required as there will be no name collisions. If repeated application of the reduction steps eventually terminates, then by the Church–Rosser theorem it will produce a β-normal form. Variable names are not needed if using a universal lambda function, such as Iota and Jot, which can create any function behavior by calling it on itself in various combinations. Explanation and applications Lambda calculus is Turing complete, that is, it is a universal model of computation that can be used to simulate any Turing machine. Its namesake, the Greek letter lambda (λ), is used in lambda expressions and lambda terms to denote binding a variable in a function. Lambda calculus may be untyped or typed. In typed lambda calculus, functions can be applied only if they are capable of accepting the given input's "type" of data. Typed lambda calculi are weaker than the untyped lambda calculus, which is the primary subject of this article, in the sense that typed lambda calculi can express less than the untyped calculus can, but on the other hand typed lambda calculi allow more things to be proven; in the simply typed lambda calculus it is, for example, a theorem that every evaluation strategy terminates for every simply typed lambda-term, whereas evaluation of untyped lambda-terms need not terminate. One reason there are many different typed lambda calculi has been the desire to do more (of what the untyped calculus can do) without giving up on being able to prove strong theorems about the calculus. Lambda calculus has applications in many different areas in mathematics, philosophy, linguistics, and computer science. Lambda calculus has played an important role in the development of the theory of programming languages. Functional programming languages implement lambda calculus. Lambda calculus is also a current research topic in category theory. History The lambda calculus was introduced by mathematician Alonzo Church in the 1930s as part of an investigation into the foundations of mathematics. The original system was shown to be logically inconsistent in 1935 when Stephen Kleene and J. B. Rosser developed the Kleene–Rosser paradox. Subsequently, in 1936 Church isolated and published just the portion relevant to computation, what is now called the untyped lambda calculus. In 1940, he also introduced a computationally weaker, but logically consistent system, known as the simply typed lambda calculus. Until the 1960s when its relation to programming languages was clarified, the lambda calculus was only a formalism. Thanks to Richard Montague and other linguists' applications in the semantics of natural language, the lambda calculus has begun to enjoy a respectable place in both linguistics and computer science. Origin of the lambda symbol There is some uncertainty over the reason for Church's use of the Greek letter lambda (λ) as the notation for function-abstraction in the lambda calculus, perhaps in part due to conflicting explanations by Church himself. According to Cardone and Hindley (2006): By the way, why did Church choose the notation “λ”? In [an unpublished 1964 letter to Harald Dickson] he stated clearly that it came from the notation “” used for class-abstraction by Whitehead and Russell, by first modifying “” to “” to distinguish function-abstraction from class-abstraction, and then changing “” to “λ” for ease of printing. This origin was also reported in [Rosser, 1984, p.338]. On the other hand, in his later years Church told two enquirers that the choice was more accidental: a symbol was needed and λ just happened to be chosen. Dana Scott has also addressed this question in various public lectures. Scott recounts that he once posed a question about the origin of the lambda symbol to Church's son-in-law John Addison, who then wrote his father-in-law a postcard: Dear Professor Church, Russell had the iota operator, Hilbert had the epsilon operator. Why did you choose lambda for your operator? According to Scott, Church's entire response consisted of returning the postcard with the following annotation: "eeny, meeny, miny, moe". Informal description Motivation Computable functions are a fundamental concept within computer science and mathematics. The lambda calculus provides a simple semantics for computation, enabling properties of computation to be studied formally. The lambda calculus incorporates two simplifications that make this semantics simple. The first simplification is that the lambda calculus treats functions "anonymously", without giving them explicit names. For example, the function can be rewritten in anonymous form as (which is read as "a tuple of and is mapped to "). Similarly, the function can be rewritten in anonymous form as where the input is simply mapped to itself. The second simplification is that the lambda calculus only uses functions of a single input. An ordinary function that requires two inputs, for instance the function, can be reworked into an equivalent function that accepts a single input, and as output returns another function, that in turn accepts a single input. For example, can be reworked into This method, known as currying, transforms a function that takes multiple arguments into a chain of functions each with a single argument. Function application of the function to the arguments (5, 2), yields at once , whereas evaluation of the curried version requires one more step // the definition of has been used with in the inner expression. This is like β-reduction. // the definition of has been used with . Again, similar to β-reduction. to arrive at the same result. The lambda calculus The lambda calculus consists of a language of lambda terms, which are defined by a certain formal syntax, and a set of transformation rules, which allow manipulation of the lambda terms. These transformation rules can be viewed as an equational theory or as an operational definition. As described above, all functions in the lambda calculus are anonymous functions, having no names. They only accept one input variable, with currying used to implement functions with several variables. Lambda terms The syntax of the lambda calculus defines some expressions as valid lambda calculus expressions and some as invalid, just as some strings of characters are valid C programs and some are not. A valid lambda calculus expression is called a "lambda term". The following three rules give an inductive definition that can be applied to build all syntactically valid lambda terms: a variable, , is itself a valid lambda term if is a lambda term, and is a variable, then (sometimes written in ASCII as ) is a lambda term (called an abstraction); if and are lambda terms, then is a lambda term (called an application). Nothing else is a lambda term. Thus a lambda term is valid if and only if it can be obtained by repeated application of these three rules. However, some parentheses can be omitted according to certain rules. For example, the outermost parentheses are usually not written. See Notation, below. An abstraction is a definition of an anonymous function that is capable of taking a single input and substituting it into the expression . It thus defines an anonymous function that takes and returns . For example, is an abstraction for the function using the term for . The definition of a function with an abstraction merely "sets up" the function but does not invoke it. The abstraction binds the variable in the term . An application represents the application of a function to an input , that is, it represents the act of calling function on input to produce . There is no concept in lambda calculus of variable declaration. In a definition such as (i.e. ), the lambda calculus treats as a variable that is not yet defined. The abstraction is syntactically valid, and represents a function that adds its input to the yet-unknown . Bracketing may be used and may be needed to disambiguate terms. For example, and denote different terms (although they coincidentally reduce to the same value). Here, the first example defines a function whose lambda term is the result of applying x to the child function, while the second example is the application of the outermost function to the input x, which returns the child function. Therefore, both examples evaluate to the identity function . Functions that operate on functions In lambda calculus, functions are taken to be 'first class values', so functions may be used as the inputs, or be returned as outputs from other functions. For example, represents the identity function, , and represents the identity function applied to . Further, represents the constant function , the function that always returns , no matter the input. In lambda calculus, function application is regarded as left-associative, so that means . There are several notions of "equivalence" and "reduction" that allow lambda terms to be "reduced" to "equivalent" lambda terms. Alpha equivalence A basic form of equivalence, definable on lambda terms, is alpha equivalence. It captures the intuition that the particular choice of a bound variable, in an abstraction, does not (usually) matter. For instance, and are alpha-equivalent lambda terms, and they both represent the same function (the identity function). The terms and are not alpha-equivalent, because they are not bound in an abstraction. In many presentations, it is usual to identify alpha-equivalent lambda terms. The following definitions are necessary in order to be able to define β-reduction: Free variables The free variables of a term are those variables not bound by an abstraction. The set of free variables of an expression is defined inductively: The free variables of are just The set of free variables of is the set of free variables of , but with removed The set of free variables of is the union of the set of free variables of and the set of free variables of . For example, the lambda term representing the identity has no free variables, but the function has a single free variable, . Capture-avoiding substitutions Suppose , and are lambda terms and and are variables. The notation indicates substitution of for in in a capture-avoiding manner. This is defined so that: ; if ; ; ; if and is not in the free variables of . The variable is said to be "fresh" for . For example, , and . The freshness condition (requiring that is not in the free variables of ) is crucial in order to ensure that substitution does not change the meaning of functions. For example, a substitution is made that ignores the freshness condition can lead to errors: . This substitution turns the constant function into the identity by substitution. In general, failure to meet the freshness condition can be remedied by alpha-renaming with a suitable fresh variable. For example, switching back to our correct notion of substitution, in the abstraction can be renamed with a fresh variable , to obtain , and the meaning of the function is preserved by substitution. β-reduction The β-reduction rule states that an application of the form reduces to the term . The notation is used to indicate that β-reduces to . For example, for every , . This demonstrates that really is the identity. Similarly, , which demonstrates that is a constant function. The lambda calculus may be seen as an idealized version of a functional programming language, like Haskell or Standard ML. Under this view, β-reduction corresponds to a computational step. This step can be repeated by additional β-reductions until there are no more applications left to reduce. In the untyped lambda calculus, as presented here, this reduction process may not terminate. For instance, consider the term . Here . That is, the term reduces to itself in a single β-reduction, and therefore the reduction process will never terminate. Another aspect of the untyped lambda calculus is that it does not distinguish between different kinds of data. For instance, it may be desirable to write a function that only operates on numbers. However, in the untyped lambda calculus, there is no way to prevent a function from being applied to truth values, strings, or other non-number objects. Formal definition Definition Lambda expressions are composed of: variables v1, v2, ...; the abstraction symbols λ (lambda) and . (dot); parentheses (). The set of lambda expressions, , can be defined inductively: If x is a variable, then If x is a variable and then If then Instances of rule 2 are known as abstractions and instances of rule 3 are known as applications. Notation To keep the notation of lambda expressions uncluttered, the following conventions are usually applied: Outermost parentheses are dropped: M N instead of (M N). Applications are assumed to be left associative: M N P may be written instead of ((M N) P). The body of an abstraction extends as far right as possible: λx.M N means λx.(M N) and not (λx.M) N. A sequence of abstractions is contracted: λx.λy.λz.N is abbreviated as λxyz.N. Free and bound variables The abstraction operator, λ, is said to bind its variable wherever it occurs in the body of the abstraction. Variables that fall within the scope of an abstraction are said to be bound. In an expression λx.M, the part λx is often called binder, as a hint that the variable x is getting bound by appending λx to M. All other variables are called free. For example, in the expression λy.x x y, y is a bound variable and x is a free variable. Also a variable is bound by its nearest abstraction. In the following example the single occurrence of x in the expression is bound by the second lambda: λx.y (λx.z x). The set of free variables of a lambda expression, M, is denoted as FV(M) and is defined by recursion on the structure of the terms, as follows: FV(x) = {x}, where x is a variable. FV(λx.M) = FV(M) \ {x}. An expression that contains no free variables is said to be closed. Closed lambda expressions are also known as combinators and are equivalent to terms in combinatory logic. Reduction The meaning of lambda expressions is defined by how expressions can be reduced. There are three kinds of reduction: α-conversion: changing bound variables; β-reduction: applying functions to their arguments; η-reduction: which captures a notion of extensionality. We also speak of the resulting equivalences: two expressions are α-equivalent, if they can be α-converted into the same expression. β-equivalence and η-equivalence are defined similarly. The term redex, short for reducible expression, refers to subterms that can be reduced by one of the reduction rules. For example, (λx.M) N is a β-redex in expressing the substitution of N for x in M. The expression to which a redex reduces is called its reduct; the reduct of (λx.M) N is M[x := N]. If x is not free in M, λx.M x is also an η-redex, with a reduct of M. α-conversion α-conversion, sometimes known as α-renaming, allows bound variable names to be changed. For example, α-conversion of λx.x might yield λy.y. Terms that differ only by α-conversion are called α-equivalent. Frequently, in uses of lambda calculus, α-equivalent terms are considered to be equivalent. The precise rules for α-conversion are not completely trivial. First, when α-converting an abstraction, the only variable occurrences that are renamed are those that are bound to the same abstraction. For example, an α-conversion of λx.λx.x could result in λy.λx.x, but it could not result in λy.λx.y. The latter has a different meaning from the original. This is analogous to the programming notion of variable shadowing. Second, α-conversion is not possible if it would result in a variable getting captured by a different abstraction. For example, if we replace x with y in λx.λy.x, we get λy.λy.y, which is not at all the same. In programming languages with static scope, α-conversion can be used to make name resolution simpler by ensuring that no variable name masks a name in a containing scope (see α-renaming to make name resolution trivial). In the De Bruijn index notation, any two α-equivalent terms are syntactically identical. Substitution Substitution, written M[V := N], is the process of replacing all free occurrences of the variable V in the expression M with expression N. Substitution on terms of the lambda calculus is defined by recursion on the structure of terms, as follows (note: x and y are only variables while M and N are any lambda expression): x[x := N] = N y[x := N] = y, if x ≠ y (M1 M2)[x := N] = M1[x := N] M2[x := N] (λx.M)[x := N] = λx.M (λy.M)[x := N] = λy.(M[x := N]), if x ≠ y and y ∉ FV(N) To substitute into an abstraction, it is sometimes necessary to α-convert the expression. For example, it is not correct for (λx.y)[y := x] to result in λx.x, because the substituted x was supposed to be free but ended up being bound. The correct substitution in this case is λz.x, up to α-equivalence. Substitution is defined uniquely up to α-equivalence. β-reduction β-reduction captures the idea of function application. β-reduction is defined in terms of substitution: the β-reduction of (λV.M) N is M[V := N]. For example, assuming some encoding of 2, 7, ×, we have the following β-reduction: (λn.n × 2) 7 → 7 × 2. β-reduction can be seen to be the same as the concept of local reducibility in natural deduction, via the Curry–Howard isomorphism. η-reduction η-reduction expresses the idea of extensionality, which in this context is that two functions are the same if and only if they give the same result for all arguments. η-reduction converts between λx.f x and f whenever x does not appear free in f. η-reduction can be seen to be the same as the concept of local completeness in natural deduction, via the Curry–Howard isomorphism. Normal forms and confluence For the untyped lambda calculus, β-reduction as a rewriting rule is neither strongly normalising nor weakly normalising. However, it can be shown that β-reduction is confluent when working up to α-conversion (i.e. we consider two normal forms to be equal if it is possible to α-convert one into the other). Therefore, both strongly normalising terms and weakly normalising terms have a unique normal form. For strongly normalising terms, any reduction strategy is guaranteed to yield the normal form, whereas for weakly normalising terms, some reduction strategies may fail to find it. Encoding datatypes The basic lambda calculus may be used to model booleans, arithmetic, data structures and recursion, as illustrated in the following sub-sections. Arithmetic in lambda calculus There are several possible ways to define the natural numbers in lambda calculus, but by far the most common are the Church numerals, which can be defined as follows: and so on. Or using the alternative syntax presented above in Notation: A Church numeral is a higher-order function—it takes a single-argument function , and returns another single-argument function. The Church numeral is a function that takes a function as argument and returns the -th composition of , i.e. the function composed with itself times. This is denoted and is in fact the -th power of (considered as an operator); is defined to be the identity function. Such repeated compositions (of a single function ) obey the laws of exponents, which is why these numerals can be used for arithmetic. (In Church's original lambda calculus, the formal parameter of a lambda expression was required to occur at least once in the function body, which made the above definition of impossible.) One way of thinking about the Church numeral , which is often useful when analysing programs, is as an instruction 'repeat n times'. For example, using the and functions defined below, one can define a function that constructs a (linked) list of n elements all equal to x by repeating 'prepend another x element' n times, starting from an empty list. The lambda term is By varying what is being repeated, and varying what argument that function being repeated is applied to, a great many different effects can be achieved. We can define a successor function, which takes a Church numeral and returns by adding another application of , where '(mf)x' means the function 'f' is applied 'm' times on 'x': Because the -th composition of composed with the -th composition of gives the -th composition of , addition can be defined as follows: can be thought of as a function taking two natural numbers as arguments and returning a natural number; it can be verified that and are β-equivalent lambda expressions. Since adding to a number can be accomplished by adding 1 times, an alternative definition is: Similarly, multiplication can be defined as Alternatively since multiplying and is the same as repeating the add function times and then applying it to zero. Exponentiation has a rather simple rendering in Church numerals, namely The predecessor function defined by for a positive integer and is considerably more difficult. The formula can be validated by showing inductively that if T denotes , then for . Two other definitions of are given below, one using conditionals and the other using pairs. With the predecessor function, subtraction is straightforward. Defining , yields when and otherwise. Logic and predicates By convention, the following two definitions (known as Church booleans) are used for the boolean values and : (Note that is equivalent to the Church numeral zero defined above) Then, with these two lambda terms, we can define some logic operators (these are just possible formulations; other expressions are equally correct): We are now able to compute some logic functions, for example: and we see that is equivalent to . A predicate is a function that returns a boolean value. The most fundamental predicate is , which returns if its argument is the Church numeral , and if its argument is any other Church numeral: The following predicate tests whether the first argument is less-than-or-equal-to the second: , and since , if and , it is straightforward to build a predicate for numerical equality. The availability of predicates and the above definition of and make it convenient to write "if-then-else" expressions in lambda calculus. For example, the predecessor function can be defined as: which can be verified by showing inductively that is the add − 1 function for > 0. Pairs A pair (2-tuple) can be defined in terms of and , by using the Church encoding for pairs. For example, encapsulates the pair (,), returns the first element of the pair, and returns the second. A linked list can be defined as either NIL for the empty list, or the of an element and a smaller list. The predicate tests for the value . (Alternatively, with , the construct obviates the need for an explicit NULL test). As an example of the use of pairs, the shift-and-increment function that maps to can be defined as which allows us to give perhaps the most transparent version of the predecessor function: Additional programming techniques There is a considerable body of programming idioms for lambda calculus. Many of these were originally developed in the context of using lambda calculus as a foundation for programming language semantics, effectively using lambda calculus as a low-level programming language. Because several programming languages include the lambda calculus (or something very similar) as a fragment, these techniques also see use in practical programming, but may then be perceived as obscure or foreign. Named constants In lambda calculus, a library would take the form of a collection of previously defined functions, which as lambda-terms are merely particular constants. The pure lambda calculus does not have a concept of named constants since all atomic lambda-terms are variables, but one can emulate having named constants by setting aside a variable as the name of the constant, using abstraction to bind that variable in the main body, and apply that abstraction to the intended definition. Thus to use to mean M (some explicit lambda-term) in N (another lambda-term, the "main program"), one can say N M Authors often introduce syntactic sugar, such as , to permit writing the above in the more intuitive order MN By chaining such definitions, one can write a lambda calculus "program" as zero or more function definitions, followed by one lambda-term using those functions that constitutes the main body of the program. A notable restriction of this is that the name is not defined in M, since M is outside the scope of the abstraction binding ; this means a recursive function definition cannot be used as the M with . The more advanced syntactic sugar construction that allows writing recursive function definitions in that naive style instead additionally employs fixed-point combinators. Recursion and fixed points Recursion is the definition of a function using the function itself. Lambda calculus cannot express this as directly as some other notations: all functions are anonymous in lambda calculus, so we can't refer to a value which is yet to be defined, inside the lambda term defining that same value. However, recursion can still be achieved by arranging for a lambda expression to receive itself as its argument value, for example in . Consider the factorial function recursively defined by . In the lambda expression which is to represent this function, a parameter (typically the first one) will be assumed to receive the lambda expression itself as its value, so that calling it – applying it to an argument – will amount to recursion. Thus to achieve recursion, the intended-as-self-referencing argument (called here) must always be passed to itself within the function body, at a call point: with to hold, so and The self-application achieves replication here, passing the function's lambda expression on to the next invocation as an argument value, making it available to be referenced and called there. This solves it but requires re-writing each recursive call as self-application. We would like to have a generic solution, without a need for any re-writes: with to hold, so and where so that Given a lambda term with first argument representing recursive call (e.g. here), the fixed-point combinator will return a self-replicating lambda expression representing the recursive function (here, ). The function does not need to be explicitly passed to itself at any point, for the self-replication is arranged in advance, when it is created, to be done each time it is called. Thus the original lambda expression is re-created inside itself, at call-point, achieving self-reference. In fact, there are many possible definitions for this operator, the simplest of them being: In the lambda calculus, is a fixed-point of , as it expands to: Now, to perform our recursive call to the factorial function, we would simply call , where n is the number we are calculating the factorial of. Given n = 4, for example, this gives: Every recursively defined function can be seen as a fixed point of some suitably defined function closing over the recursive call with an extra argument, and therefore, using , every recursively defined function can be expressed as a lambda expression. In particular, we can now cleanly define the subtraction, multiplication and comparison predicate of natural numbers recursively. Standard terms Certain terms have commonly accepted names: is the identity function. and form complete combinator calculus systems that can express any lambda term - see the next section. is , the smallest term that has no normal form. is standard and defined above. and defined above are commonly abbreviated as and . Abstraction elimination If N is a lambda-term without abstraction, but possibly containing named constants (combinators), then there exists a lambda-term T(,N) which is equivalent to N but lacks abstraction (except as part of the named constants, if these are considered non-atomic). This can also be viewed as anonymising variables, as T(,N) removes all occurrences of from N, while still allowing argument values to be substituted into the positions where N contains an . The conversion function T can be defined by: T(, ) := I T(, N) := K N if is not free in N. T(, M N) := S T(, M) T(, N) In either case, a term of the form T(,N) P can reduce by having the initial combinator I, K, or S grab the argument P, just like β-reduction of N P would do. I returns that argument. K throws the argument away, just like N would do if has no free occurrence in N. S passes the argument on to both subterms of the application, and then applies the result of the first to the result of the second. The combinators B and C are similar to S, but pass the argument on to only one subterm of an application (B to the "argument" subterm and C to the "function" subterm), thus saving a subsequent K if there is no occurrence of in one subterm. In comparison to B and C, the S combinator actually conflates two functionalities: rearranging arguments, and duplicating an argument so that it may be used in two places. The W combinator does only the latter, yielding the B, C, K, W system as an alternative to SKI combinator calculus. Typed lambda calculus A typed lambda calculus is a typed formalism that uses the lambda-symbol () to denote anonymous function abstraction. In this context, types are usually objects of a syntactic nature that are assigned to lambda terms; the exact nature of a type depends on the calculus considered (see Kinds of typed lambda calculi). From a certain point of view, typed lambda calculi can be seen as refinements of the untyped lambda calculus but from another point of view, they can also be considered the more fundamental theory and untyped lambda calculus a special case with only one type. Typed lambda calculi are foundational programming languages and are the base of typed functional programming languages such as ML and Haskell and, more indirectly, typed imperative programming languages. Typed lambda calculi play an important role in the design of type systems for programming languages; here typability usually captures desirable properties of the program, e.g. the program will not cause a memory access violation. Typed lambda calculi are closely related to mathematical logic and proof theory via the Curry–Howard isomorphism and they can be considered as the internal language of classes of categories, e.g. the simply typed lambda calculus is the language of Cartesian closed categories (CCCs). Reduction strategies Whether a term is normalising or not, and how much work needs to be done in normalising it if it is, depends to a large extent on the reduction strategy used. Common lambda calculus reduction strategies include: Normal order The leftmost, outermost redex is always reduced first. That is, whenever possible the arguments are substituted into the body of an abstraction before the arguments are reduced. Applicative order The leftmost, innermost redex is always reduced first. Intuitively this means a function's arguments are always reduced before the function itself. Applicative order always attempts to apply functions to normal forms, even when this is not possible. Full β-reductions Any redex can be reduced at any time. This means essentially the lack of any particular reduction strategy—with regard to reducibility, "all bets are off". Weak reduction strategies do not reduce under lambda abstractions: Call by value A redex is reduced only when its right hand side has reduced to a value (variable or abstraction). Only the outermost redexes are reduced. Call by name As normal order, but no reductions are performed inside abstractions. For example, is in normal form according to this strategy, although it contains the redex . Strategies with sharing reduce computations that are "the same" in parallel: Optimal reduction As normal order, but computations that have the same label are reduced simultaneously. Call by need As call by name (hence weak), but function applications that would duplicate terms instead name the argument, which is then reduced only "when it is needed". Computability There is no algorithm that takes as input any two lambda expressions and outputs or depending on whether one expression reduces to the other. More precisely, no computable function can decide the question. This was historically the first problem for which undecidability could be proven. As usual for such a proof, computable means computable by any model of computation that is Turing complete. In fact computability can itself be defined via the lambda calculus: a function F: N → N of natural numbers is a computable function if and only if there exists a lambda expression f such that for every pair of x, y in N, F(x)=y if and only if f =β , where and are the Church numerals corresponding to x and y, respectively and =β meaning equivalence with β-reduction. See the Church–Turing thesis for other approaches to defining computability and their equivalence. Church's proof of uncomputability first reduces the problem to determining whether a given lambda expression has a normal form. Then he assumes that this predicate is computable, and can hence be expressed in lambda calculus. Building on earlier work by Kleene and constructing a Gödel numbering for lambda expressions, he constructs a lambda expression that closely follows the proof of Gödel's first incompleteness theorem. If is applied to its own Gödel number, a contradiction results. Complexity The notion of computational complexity for the lambda calculus is a bit tricky, because the cost of a β-reduction may vary depending on how it is implemented. To be precise, one must somehow find the location of all of the occurrences of the bound variable in the expression , implying a time cost, or one must keep track of the locations of free variables in some way, implying a space cost. A naïve search for the locations of in is O(n) in the length n of . Director strings were an early approach that traded this time cost for a quadratic space usage. More generally this has led to the study of systems that use explicit substitution. In 2014 it was shown that the number of β-reduction steps taken by normal order reduction to reduce a term is a reasonable time cost model, that is, the reduction can be simulated on a Turing machine in time polynomially proportional to the number of steps. This was a long-standing open problem, due to size explosion, the existence of lambda terms which grow exponentially in size for each β-reduction. The result gets around this by working with a compact shared representation. The result makes clear that the amount of space needed to evaluate a lambda term is not proportional to the size of the term during reduction. It is not currently known what a good measure of space complexity would be. An unreasonable model does not necessarily mean inefficient. Optimal reduction reduces all computations with the same label in one step, avoiding duplicated work, but the number of parallel β-reduction steps to reduce a given term to normal form is approximately linear in the size of the term. This is far too small to be a reasonable cost measure, as any Turing machine may be encoded in the lambda calculus in size linearly proportional to the size of the Turing machine. The true cost of reducing lambda terms is not due to β-reduction per se but rather the handling of the duplication of redexes during β-reduction. It is not known if optimal reduction implementations are reasonable when measured with respect to a reasonable cost model such as the number of leftmost-outermost steps to normal form, but it has been shown for fragments of the lambda calculus that the optimal reduction algorithm is efficient and has at most a quadratic overhead compared to leftmost-outermost. In addition the BOHM prototype implementation of optimal reduction outperformed both Caml Light and Haskell on pure lambda terms. Lambda calculus and programming languages As pointed out by Peter Landin's 1965 paper "A Correspondence between ALGOL 60 and Church's Lambda-notation", sequential procedural programming languages can be understood in terms of the lambda calculus, which provides the basic mechanisms for procedural abstraction and procedure (subprogram) application. Anonymous functions For example, in Lisp the "square" function can be expressed as a lambda expression as follows: (lambda (x) (* x x)) The above example is an expression that evaluates to a first-class function. The symbol lambda creates an anonymous function, given a list of parameter names, (x) – just a single argument in this case, and an expression that is evaluated as the body of the function, (* x x). Anonymous functions are sometimes called lambda expressions. For example, Pascal and many other imperative languages have long supported passing subprograms as arguments to other subprograms through the mechanism of function pointers. However, function pointers are not a sufficient condition for functions to be first class datatypes, because a function is a first class datatype if and only if new instances of the function can be created at run-time. And this run-time creation of functions is supported in Smalltalk, JavaScript and Wolfram Language, and more recently in Scala, Eiffel ("agents"), C# ("delegates") and C++11, among others. Parallelism and concurrency The Church–Rosser property of the lambda calculus means that evaluation (β-reduction) can be carried out in any order, even in parallel. This means that various nondeterministic evaluation strategies are relevant. However, the lambda calculus does not offer any explicit constructs for parallelism. One can add constructs such as Futures to the lambda calculus. Other process calculi have been developed for describing communication and concurrency. Semantics The fact that lambda calculus terms act as functions on other lambda calculus terms, and even on themselves, led to questions about the semantics of the lambda calculus. Could a sensible meaning be assigned to lambda calculus terms? The natural semantics was to find a set D isomorphic to the function space D → D, of functions on itself. However, no nontrivial such D can exist, by cardinality constraints because the set of all functions from D to D has greater cardinality than D, unless D is a singleton set. In the 1970s, Dana Scott showed that if only continuous functions were considered, a set or domain D with the required property could be found, thus providing a model for the lambda calculus. This work also formed the basis for the denotational semantics of programming languages. Variations and extensions These extensions are in the lambda cube: Typed lambda calculus – Lambda calculus with typed variables (and functions) System F – A typed lambda calculus with type-variables Calculus of constructions – A typed lambda calculus with types as first-class values These formal systems are extensions of lambda calculus that are not in the lambda cube: Binary lambda calculus – A version of lambda calculus with binary I/O, a binary encoding of terms, and a designated universal machine. Lambda-mu calculus – An extension of the lambda calculus for treating classical logic These formal systems are variations of lambda calculus: Kappa calculus – A first-order analogue of lambda calculus These formal systems are related to lambda calculus: Combinatory logic – A notation for mathematical logic without variables SKI combinator calculus – A computational system based on the S, K and I combinators, equivalent to lambda calculus, but reducible without variable substitutions See also Applicative computing systems – Treatment of objects in the style of the lambda calculus Cartesian closed category – A setting for lambda calculus in category theory Categorical abstract machine – A model of computation applicable to lambda calculus Curry–Howard isomorphism – The formal correspondence between programs and proofs De Bruijn index – notation disambiguating alpha conversions De Bruijn notation – notation using postfix modification functions Deductive lambda calculus – The consideration of the problems associated with considering lambda calculus as a Deductive system. Domain theory – Study of certain posets giving denotational semantics for lambda calculus Evaluation strategy – Rules for the evaluation of expressions in programming languages Explicit substitution – The theory of substitution, as used in β-reduction Functional programming Harrop formula – A kind of constructive logical formula such that proofs are lambda terms Interaction nets Kleene–Rosser paradox – A demonstration that some form of lambda calculus is inconsistent Knights of the Lambda Calculus – A semi-fictional organization of LISP and Scheme hackers Krivine machine – An abstract machine to interpret call-by-name in lambda calculus Lambda calculus definition – Formal definition of the lambda calculus. Let expression – An expression closely related to an abstraction. Minimalism (computing) Rewriting – Transformation of formulæ in formal systems SECD machine – A virtual machine designed for the lambda calculus Scott–Curry theorem – A theorem about sets of lambda terms To Mock a Mockingbird – An introduction to combinatory logic Universal Turing machine – A formal computing machine that is equivalent to lambda calculus Unlambda – An esoteric functional programming language based on combinatory logic Notes References Further reading Abelson, Harold & Gerald Jay Sussman. Structure and Interpretation of Computer Programs. The MIT Press. . Hendrik Pieter Barendregt Introduction to Lambda Calculus. Henk Barendregt, The Impact of the Lambda Calculus in Logic and Computer Science. The Bulletin of Symbolic Logic, Volume 3, Number 2, June 1997. Barendregt, Hendrik Pieter, The Type Free Lambda Calculus pp1091–1132 of Handbook of Mathematical Logic, North-Holland (1977) Cardone and Hindley, 2006. History of Lambda-calculus and Combinatory Logic. In Gabbay and Woods (eds.), Handbook of the History of Logic, vol. 5. Elsevier. Church, Alonzo, An unsolvable problem of elementary number theory, American Journal of Mathematics, 58 (1936), pp. 345–363. This paper contains the proof that the equivalence of lambda expressions is in general not decidable. Alonzo Church, The Calculi of Lambda-Conversion () Frink Jr., Orrin, Review: The Calculi of Lambda-Conversion Kleene, Stephen, A theory of positive integers in formal logic, American Journal of Mathematics, 57 (1935), pp. 153–173 and 219–244. Contains the lambda calculus definitions of several familiar functions. Landin, Peter, A Correspondence Between ALGOL 60 and Church's Lambda-Notation, Communications of the ACM, vol. 8, no. 2 (1965), pages 89–101. Available from the ACM site. A classic paper highlighting the importance of lambda calculus as a basis for programming languages. Larson, Jim, An Introduction to Lambda Calculus and Scheme. A gentle introduction for programmers. Schalk, A. and Simmons, H. (2005) An introduction to λ-calculi and arithmetic with a decent selection of exercises. Notes for a course in the Mathematical Logic MSc at Manchester University. A paper giving a formal underpinning to the idea of 'meaning-is-use' which, even if based on proofs, it is different from proof-theoretic semantics as in the Dummett–Prawitz tradition since it takes reduction as the rules giving meaning. Hankin, Chris, An Introduction to Lambda Calculi for Computer Scientists, Monographs/textbooks for graduate students: Morten Heine Sørensen, Paweł Urzyczyn, Lectures on the Curry–Howard isomorphism, Elsevier, 2006, is a recent monograph that covers the main topics of lambda calculus from the type-free variety, to most typed lambda calculi, including more recent developments like pure type systems and the lambda cube. It does not cover subtyping extensions. covers lambda calculi from a practical type system perspective; some topics like dependent types are only mentioned, but subtyping is an important topic.Some parts of this article are based on material from FOLDOC, used with permission. External links Graham Hutton, Lambda Calculus, a short (12 minutes) Computerphile video on the Lambda Calculus Helmut Brandl, Step by Step Introduction to Lambda Calculus Achim Jung, A Short Introduction to the Lambda Calculus-(PDF) Dana Scott, A timeline of lambda calculus-(PDF) David C. Keenan, To Dissect a Mockingbird: A Graphical Notation for the Lambda Calculus with Animated Reduction Raúl Rojas, A Tutorial Introduction to the Lambda Calculus-(PDF) Peter Selinger, Lecture Notes on the Lambda Calculus-(PDF) L. Allison, Some executable λ-calculus examples Georg P. Loczewski, The Lambda Calculus and A++ Bret Victor, Alligator Eggs: A Puzzle Game Based on Lambda Calculus Lambda Calculus on Safalra's Website LCI Lambda Interpreter a simple yet powerful pure calculus interpreter Lambda Calculus links on Lambda-the-Ultimate Mike Thyer, Lambda Animator, a graphical Java applet demonstrating alternative reduction strategies. Implementing the Lambda calculus using C++ Templates Marius Buliga, Graphic lambda calculus Lambda Calculus as a Workflow Model by Peter Kelly, Paul Coddington, and Andrew Wendelborn; mentions graph reduction as a common means of evaluating lambda expressions and discusses the applicability of lambda calculus for distributed computing (due to the Church–Rosser property, which enables parallel graph reduction for lambda expressions). Shane Steinert-Threlkeld, "Lambda Calculi", Internet Encyclopedia of Philosophy'' Anton Salikhmetov, Macro Lambda Calculus 1936 in computing Articles with example Lisp (programming language) code Computability theory Formal methods Models of computation Theoretical computer science	[ 0.0950322151184082, -0.07383941113948822, -0.06652984768152237, 0.07387806475162506, -0.12376423180103302, 0.23807351291179657, -0.3733159899711609, -0.04244205728173256, 0.1722334325313568, 0.030675368383526802, -0.26614952087402344, 0.6547445058822632, -0.8044250011444092, -0.33411332964...
18208	https://en.wikipedia.org/wiki/Lossy%20compression	Lossy compression	In information technology, lossy compression or irreversible compression is the class of data encoding methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size for storing, handling, and transmitting content. The different versions of the photo of the cat on this page show how higher degrees of approximation create coarser images as more details are removed. This is opposed to lossless data compression (reversible data compression) which does not degrade the data. The amount of data reduction possible using lossy compression is much higher than using lossless techniques. Well-designed lossy compression technology often reduces file sizes significantly before degradation is noticed by the end-user. Even when noticeable by the user, further data reduction may be desirable (e.g., for real-time communication or to reduce transmission times or storage needs). The most widely used lossy compression algorithm is the discrete cosine transform (DCT), first published by Nasir Ahmed, T. Natarajan and K. R. Rao in 1974. In 2019 a new family of sinusoidal-hyperbolic transform functions, which have comparable properties and performance with DCT, were proposed for lossy compression. Lossy compression is most commonly used to compress multimedia data (audio, video, and images), especially in applications such as streaming media and internet telephony. By contrast, lossless compression is typically required for text and data files, such as bank records and text articles. It can be advantageous to make a master lossless file which can then be used to produce additional copies from. This allows one to avoid basing new compressed copies off of a lossy source file, which would yield additional artifacts and further unnecessary information loss. Types It is possible to compress many types of digital data in a way that reduces the size of a computer file needed to store it, or the bandwidth needed to transmit it, with no loss of the full information contained in the original file. A picture, for example, is converted to a digital file by considering it to be an array of dots and specifying the color and brightness of each dot. If the picture contains an area of the same color, it can be compressed without loss by saying "200 red dots" instead of "red dot, red dot, ...(197 more times)..., red dot." The original data contains a certain amount of information, and there is a lower limit to the size of file that can carry all the information. Basic information theory says that there is an absolute limit in reducing the size of this data. When data is compressed, its entropy increases, and it cannot increase indefinitely. For example, a compressed ZIP file is smaller than its original, but repeatedly compressing the same file will not reduce the size to nothing. Most compression algorithms can recognize when further compression would be pointless and would in fact increase the size of the data. In many cases, files or data streams contain more information than is needed. For example, a picture may have more detail than the eye can distinguish when reproduced at the largest size intended; likewise, an audio file does not need a lot of fine detail during a very loud passage. Developing lossy compression techniques as closely matched to human perception as possible is a complex task. Sometimes the ideal is a file that provides exactly the same perception as the original, with as much digital information as possible removed; other times, perceptible loss of quality is considered a valid tradeoff. The terms "irreversible" and "reversible" are preferred over "lossy" and "lossless" respectively for some applications, such as medical image compression, to circumvent the negative implications of "loss". The type and amount of loss can affect the utility of the images. Artifacts or undesirable effects of compression may be clearly discernible yet the result still useful for the intended purpose. Or lossy compressed images may be 'visually lossless', or in the case of medical images, so-called Diagnostically Acceptable Irreversible Compression (DAIC) may have been applied. Transform coding Some forms of lossy compression can be thought of as an application of transform coding, which is a type of data compression used for digital images, digital audio signals, and digital video. The transformation is typically used to enable better (more targeted) quantization. Knowledge of the application is used to choose information to discard, thereby lowering its bandwidth. The remaining information can then be compressed via a variety of methods. When the output is decoded, the result may not be identical to the original input, but is expected to be close enough for the purpose of the application. The most common form of lossy compression is a transform coding method, the discrete cosine transform (DCT), which was first published by Nasir Ahmed, T. Natarajan and K. R. Rao in 1974. DCT is the most widely used form of lossy compression, for popular image compression formats (such as JPEG), video coding standards (such as MPEG and H.264/AVC) and audio compression formats (such as MP3 and AAC). In the case of audio data, a popular form of transform coding is perceptual coding, which transforms the raw data to a domain that more accurately reflects the information content. For example, rather than expressing a sound file as the amplitude levels over time, one may express it as the frequency spectrum over time, which corresponds more accurately to human audio perception. While data reduction (compression, be it lossy or lossless) is a main goal of transform coding, it also allows other goals: one may represent data more accurately for the original amount of space – for example, in principle, if one starts with an analog or high-resolution digital master, an MP3 file of a given size should provide a better representation than a raw uncompressed audio in WAV or AIFF file of the same size. This is because uncompressed audio can only reduce file size by lowering bit rate or depth, whereas compressing audio can reduce size while maintaining bit rate and depth. This compression becomes a selective loss of the least significant data, rather than losing data across the board. Further, a transform coding may provide a better domain for manipulating or otherwise editing the data – for example, equalization of audio is most naturally expressed in the frequency domain (boost the bass, for instance) rather than in the raw time domain. From this point of view, perceptual encoding is not essentially about discarding data, but rather about a better representation of data. Another use is for backward compatibility and graceful degradation: in color television, encoding color via a luminance-chrominance transform domain (such as YUV) means that black-and-white sets display the luminance, while ignoring the color information. Another example is chroma subsampling: the use of color spaces such as YIQ, used in NTSC, allow one to reduce the resolution on the components to accord with human perception – humans have highest resolution for black-and-white (luma), lower resolution for mid-spectrum colors like yellow and green, and lowest for red and blues – thus NTSC displays approximately 350 pixels of luma per scanline, 150 pixels of yellow vs. green, and 50 pixels of blue vs. red, which are proportional to human sensitivity to each component. Information loss Lossy compression formats suffer from generation loss: repeatedly compressing and decompressing the file will cause it to progressively lose quality. This is in contrast with lossless data compression, where data will not be lost via the use of such a procedure. Information-theoretical foundations for lossy data compression are provided by rate-distortion theory. Much like the use of probability in optimal coding theory, rate-distortion theory heavily draws on Bayesian estimation and decision theory in order to model perceptual distortion and even aesthetic judgment. There are two basic lossy compression schemes: In lossy transform codecs, samples of picture or sound are taken, chopped into small segments, transformed into a new basis space, and quantized. The resulting quantized values are then entropy coded. In lossy predictive codecs, previous and/or subsequent decoded data is used to predict the current sound sample or image frame. The error between the predicted data and the real data, together with any extra information needed to reproduce the prediction, is then quantized and coded. In some systems the two techniques are combined, with transform codecs being used to compress the error signals generated by the predictive stage. Comparison The advantage of lossy methods over lossless methods is that in some cases a lossy method can produce a much smaller compressed file than any lossless method, while still meeting the requirements of the application. Lossy methods are most often used for compressing sound, images or videos. This is because these types of data are intended for human interpretation where the mind can easily "fill in the blanks" or see past very minor errors or inconsistencies – ideally lossy compression is transparent (imperceptible), which can be verified via an ABX test. Data files using lossy compression are smaller in size and thus cost less to store and to transmit over the Internet, a crucial consideration for streaming video services such as Netflix and streaming audio services such as Spotify. Emotional effects A study conducted by the Audio Engineering Library concluded that lower bit rate (112 kbps) lossy compression formats such as MP3s have distinct effects on timbral and emotional characteristics, tending to strengthen negative emotional qualities and weaken positive ones. The study further noted that the trumpet is the instrument most affected by compression, while the horn is least. Transparency When a user acquires a lossily compressed file, (for example, to reduce download time) the retrieved file can be quite different from the original at the bit level while being indistinguishable to the human ear or eye for most practical purposes. Many compression methods focus on the idiosyncrasies of human physiology, taking into account, for instance, that the human eye can see only certain wavelengths of light. The psychoacoustic model describes how sound can be highly compressed without degrading perceived quality. Flaws caused by lossy compression that are noticeable to the human eye or ear are known as compression artifacts. Compression ratio The compression ratio (that is, the size of the compressed file compared to that of the uncompressed file) of lossy video codecs is nearly always far superior to that of the audio and still-image equivalents. Video can be compressed immensely (e.g., 100:1) with little visible quality loss Audio can often be compressed at 10:1 with almost imperceptible loss of quality Still images are often lossily compressed at 10:1, as with audio, but the quality loss is more noticeable, especially on closer inspection. Transcoding and editing An important caveat about lossy compression (formally transcoding), is that editing lossily compressed files causes digital generation loss from the re-encoding. This can be avoided by only producing lossy files from (lossless) originals and only editing (copies of) original files, such as images in raw image format instead of JPEG. If data which has been compressed lossily is decoded and compressed losslessly, the size of the result can be comparable with the size of the data before lossy compression, but the data already lost cannot be recovered. When deciding to use lossy conversion without keeping the original, format conversion may be needed in the future to achieve compatibility with software or devices (format shifting), or to avoid paying patent royalties for decoding or distribution of compressed files. Editing of lossy files By modifying the compressed data directly without decoding and re-encoding, some editing of lossily compressed files without degradation of quality is possible. Editing which reduces the file size as if it had been compressed to a greater degree, but without more loss than this, is sometimes also possible. JPEG The primary programs for lossless editing of JPEGs are jpegtran, and the derived exiftran (which also preserves Exif information), and Jpegcrop (which provides a Windows interface). These allow the image to be cropped, rotated, flipped, and flopped, or even converted to grayscale (by dropping the chrominance channel). While unwanted information is destroyed, the quality of the remaining portion is unchanged. Some other transforms are possible to some extent, such as joining images with the same encoding (composing side by side, as on a grid) or pasting images such as logos onto existing images (both via Jpegjoin), or scaling. Some changes can be made to the compression without re-encoding: Optimizing the compression (to reduce size without change to the decoded image) Converting between progressive and non-progressive encoding. The freeware Windows-only IrfanView has some lossless JPEG operations in its JPG_TRANSFORM plugin. Metadata Metadata, such as ID3 tags, Vorbis comments, or Exif information, can usually be modified or removed without modifying the underlying data. Downsampling/compressed representation scalability One may wish to downsample or otherwise decrease the resolution of the represented source signal and the quantity of data used for its compressed representation without re-encoding, as in bitrate peeling, but this functionality is not supported in all designs, as not all codecs encode data in a form that allows less important detail to simply be dropped. Some well-known designs that have this capability include JPEG 2000 for still images and H.264/MPEG-4 AVC based Scalable Video Coding for video. Such schemes have also been standardized for older designs as well, such as JPEG images with progressive encoding, and MPEG-2 and MPEG-4 Part 2 video, although those prior schemes had limited success in terms of adoption into real-world common usage. Without this capacity, which is often the case in practice, to produce a representation with lower resolution or lower fidelity than a given one, one needs to start with the original source signal and encode, or start with a compressed representation and then decompress and re-encode it (transcoding), though the latter tends to cause digital generation loss. Another approach is to encode the original signal at several different bitrates, and then either choose which to use (as when streaming over the internet – as in RealNetworks' "SureStream" – or offering varying downloads, as at Apple's iTunes Store), or broadcast several, where the best that is successfully received is used, as in various implementations of hierarchical modulation. Similar techniques are used in mipmaps, pyramid representations, and more sophisticated scale space methods. Some audio formats feature a combination of a lossy format and a lossless correction which when combined reproduce the original signal; the correction can be stripped, leaving a smaller, lossily compressed, file. Such formats include MPEG-4 SLS (Scalable to Lossless), WavPack, OptimFROG DualStream, and DTS-HD Master Audio in lossless (XLL) mode). Methods Graphics Image Discrete cosine transform (DCT) JPEG WebP (high-density lossless or lossy compression of RGB and RGBA images) High Efficiency Image Format (HEIF) Better Portable Graphics (BPG) (lossless or lossy compression) JPEG XR, a successor of JPEG with support for high-dynamic range, wide gamut pixel formats (lossless or lossy compression) Wavelet compression JPEG 2000, JPEG's successor format that uses wavelets (lossless or lossy compression) DjVu ICER, used by the Mars Rovers, related to JPEG 2000 in its use of wavelets PGF, Progressive Graphics File (lossless or lossy compression) Cartesian Perceptual Compression, also known as CPC Fractal compression JBIG2 (lossless or lossy compression) S3TC texture compression for 3D computer graphics hardware 3D computer graphics glTF Video Discrete cosine transform (DCT) H.261 Motion JPEG MPEG-1 Part 2 MPEG-2 Part 2 (H.262) MPEG-4 Part 2 (H.263) Advanced Video Coding (AVC / H.264 / MPEG-4 AVC) (may also be lossless, even in certain video sections) High Efficiency Video Coding (HEVC / H.265) Ogg Theora (noted for its lack of patent restrictions) VC-1 Wavelet compression Motion JPEG 2000 Dirac Sorenson video codec Audio General Modified discrete cosine transform (MDCT) Dolby Digital (AC-3) Adaptive Transform Acoustic Coding (ATRAC) MPEG Layer III (MP3) Advanced Audio Coding (AAC / MP4 Audio) Vorbis Windows Media Audio (WMA) (Standard and Pro profiles are lossy. WMA Lossless is also available.) LDAC Opus (Notable for lack of patent restrictions, low delay, and high quality speech and general audio.) Adaptive differential pulse-code modulation (ADPCM) Master Quality Authenticated (MQA) MPEG-1 Audio Layer II (MP2) Musepack (based on Musicam) aptX/ aptX-HD Speech Linear predictive coding (LPC) Adaptive predictive coding (APC) Code-excited linear prediction (CELP) Algebraic code-excited linear prediction (ACELP) Relaxed code-excited linear prediction (RCELP) Low-delay CELP (LD-CELP) Adaptive Multi-Rate (used in GSM and 3GPP) Codec2 (noted for its lack of patent restrictions) Speex (noted for its lack of patent restrictions) Modified discrete cosine transform (MDCT) AAC-LD Constrained Energy Lapped Transform (CELT) Opus (mostly for real-time applications) Other data Researchers have (semi-seriously) performed lossy compression on text by either using a thesaurus to substitute short words for long ones, or generative text techniques, although these sometimes fall into the related category of lossy data conversion. Lowering resolution A general kind of lossy compression is to lower the resolution of an image, as in image scaling, particularly decimation. One may also remove less "lower information" parts of an image, such as by seam carving. Many media transforms, such as Gaussian blur, are, like lossy compression, irreversible: the original signal cannot be reconstructed from the transformed signal. However, in general these will have the same size as the original, and are not a form of compression. Lowering resolution has practical uses, as the NASA New Horizons craft transmitted thumbnails of its encounter with Pluto-Charon before it sent the higher resolution images. Another solution for slow connections is the usage of Image interlacing which progressively defines the image. Thus a partial transmission is enough to preview the final image, in a lower resolution version, without creating a scaled and a full version too. See also Data compression Lossless compression Compression artifact Rate–distortion theory List of codecs Lenna Image scaling Seam carving Transcoding Notes External links Lossy audio formats, comparing the speed and compression strength of five lossy audio formats. Data compression basics, including chapters on lossy compression of images, audio and video. Lossy PNG image compression (research) (Wayback Machine copy) Using lossy GIF/PNG compression for the web (article) JPG for Archiving, comparing the suitability of JPG and lossless compression for image archives Data compression Lossy compression algorithms fr:Compression de données#Compression avec pertes	[ -0.0966474711894989, 0.3458602726459503, -0.24361811578273773, 0.25772422552108765, 0.12062376737594604, 0.09295227378606796, 0.35240650177001953, 0.47938239574432373, 0.32769784331321716, -0.5768309235572815, -1.0083729028701782, 0.36711716651916504, -0.1209411695599556, 0.530540406703949...
18209	https://en.wikipedia.org/wiki/Lossless%20compression	Lossless compression	Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data. By contrast, lossy compression permits reconstruction only of an approximation of the original data, though usually with greatly improved compression rates (and therefore reduced media sizes). By operation of the pigeonhole principle, no lossless compression algorithm can efficiently compress all possible data. For this reason, many different algorithms exist that are designed either with a specific type of input data in mind or with specific assumptions about what kinds of redundancy the uncompressed data are likely to contain. Therefore, compression ratios tend to be stronger on human- and machine-readable documents and code in comparison to entropic binary data (random bytes). Lossless data compression is used in many applications. For example, it is used in the ZIP file format and in the GNU tool gzip. It is also often used as a component within lossy data compression technologies (e.g. lossless mid/side joint stereo preprocessing by MP3 encoders and other lossy audio encoders). Lossless compression is used in cases where it is important that the original and the decompressed data be identical, or where deviations from the original data would be unfavourable. Typical examples are executable programs, text documents, and source code. Some image file formats, like PNG or GIF, use only lossless compression, while others like TIFF and MNG may use either lossless or lossy methods. Lossless audio formats are most often used for archiving or production purposes, while smaller lossy audio files are typically used on portable players and in other cases where storage space is limited or exact replication of the audio is unnecessary. Lossless compression techniques Most lossless compression programs do two things in sequence: the first step generates a statistical model for the input data, and the second step uses this model to map input data to bit sequences in such a way that "probable" (e.g. frequently encountered) data will produce shorter output than "improbable" data. The primary encoding algorithms used to produce bit sequences are Huffman coding (also used by the deflate algorithm) and arithmetic coding. Arithmetic coding achieves compression rates close to the best possible for a particular statistical model, which is given by the information entropy, whereas Huffman compression is simpler and faster but produces poor results for models that deal with symbol probabilities close to 1. There are two primary ways of constructing statistical models: in a static model, the data is analyzed and a model is constructed, then this model is stored with the compressed data. This approach is simple and modular, but has the disadvantage that the model itself can be expensive to store, and also that it forces using a single model for all data being compressed, and so performs poorly on files that contain heterogeneous data. Adaptive models dynamically update the model as the data is compressed. Both the encoder and decoder begin with a trivial model, yielding poor compression of initial data, but as they learn more about the data, performance improves. Most popular types of compression used in practice now use adaptive coders. Lossless compression methods may be categorized according to the type of data they are designed to compress. While, in principle, any general-purpose lossless compression algorithm (general-purpose meaning that they can accept any bitstring) can be used on any type of data, many are unable to achieve significant compression on data that are not of the form for which they were designed to compress. Many of the lossless compression techniques used for text also work reasonably well for indexed images. Multimedia These techniques take advantage of the specific characteristics of images such as the common phenomenon of contiguous 2-D areas of similar tones. Every pixel but the first is replaced by the difference to its left neighbor. This leads to small values having a much higher probability than large values. This is often also applied to sound files, and can compress files that contain mostly low frequencies and low volumes. For images, this step can be repeated by taking the difference to the top pixel, and then in videos, the difference to the pixel in the next frame can be taken. A hierarchical version of this technique takes neighboring pairs of data points, stores their difference and sum, and on a higher level with lower resolution continues with the sums. This is called discrete wavelet transform. JPEG2000 additionally uses data points from other pairs and multiplication factors to mix them into the difference. These factors must be integers, so that the result is an integer under all circumstances. So the values are increased, increasing file size, but hopefully the distribution of values is more peaked. The adaptive encoding uses the probabilities from the previous sample in sound encoding, from the left and upper pixel in image encoding, and additionally from the previous frame in video encoding. In the wavelet transformation, the probabilities are also passed through the hierarchy. Historical legal issues Many of these methods are implemented in open-source and proprietary tools, particularly LZW and its variants. Some algorithms are patented in the United States and other countries and their legal usage requires licensing by the patent holder. Because of patents on certain kinds of LZW compression, and in particular licensing practices by patent holder Unisys that many developers considered abusive, some open source proponents encouraged people to avoid using the Graphics Interchange Format (GIF) for compressing still image files in favor of Portable Network Graphics (PNG), which combines the LZ77-based deflate algorithm with a selection of domain-specific prediction filters. However, the patents on LZW expired on June 20, 2003. Many of the lossless compression techniques used for text also work reasonably well for indexed images, but there are other techniques that do not work for typical text that are useful for some images (particularly simple bitmaps), and other techniques that take advantage of the specific characteristics of images (such as the common phenomenon of contiguous 2-D areas of similar tones, and the fact that color images usually have a preponderance of a limited range of colors out of those representable in the color space). As mentioned previously, lossless sound compression is a somewhat specialized area. Lossless sound compression algorithms can take advantage of the repeating patterns shown by the wave-like nature of the data – essentially using autoregressive models to predict the "next" value and encoding the (hopefully small) difference between the expected value and the actual data. If the difference between the predicted and the actual data (called the error) tends to be small, then certain difference values (like 0, +1, −1 etc. on sample values) become very frequent, which can be exploited by encoding them in few output bits. It is sometimes beneficial to compress only the differences between two versions of a file (or, in video compression, of successive images within a sequence). This is called delta encoding (from the Greek letter Δ, which in mathematics, denotes a difference), but the term is typically only used if both versions are meaningful outside compression and decompression. For example, while the process of compressing the error in the above-mentioned lossless audio compression scheme could be described as delta encoding from the approximated sound wave to the original sound wave, the approximated version of the sound wave is not meaningful in any other context. Lossless compression methods No lossless compression algorithm can efficiently compress all possible data (see the section Limitations below for details). For this reason, many different algorithms exist that are designed either with a specific type of input data in mind or with specific assumptions about what kinds of redundancy the uncompressed data are likely to contain. Some of the most common lossless compression algorithms are listed below. General purpose Run-length encoding (RLE) – Simple scheme that provides good compression of data containing many runs of the same value Huffman coding – Entropy encoding, pairs well with other algorithms Arithmetic coding – Entropy encoding ANS – Entropy encoding, used by LZFSE and Zstandard Lempel-Ziv compression (LZ77 and LZ78) – Dictionary-based algorithm that forms the basis for many other algorithms Lempel–Ziv–Storer–Szymanski (LZSS) – Used by WinRAR in tandem with Huffman coding Deflate – Combines LZSS compression with Huffman coding, used by ZIP, gzip, and PNG images Lempel–Ziv–Welch (LZW) – Used by GIF images and Unix's compress utility Lempel–Ziv–Markov chain algorithm (LZMA) – Very high compression ratio, used by 7zip and xz Burrows–Wheeler transform reversible transform for making textual data more compressible, used by bzip2 Prediction by partial matching (PPM) – Optimized for compressing plain text Audio Apple Lossless (ALAC – Apple Lossless Audio Codec) Adaptive Transform Acoustic Coding (ATRAC) Audio Lossless Coding (also known as MPEG-4 ALS) Direct Stream Transfer (DST) Dolby TrueHD DTS-HD Master Audio Free Lossless Audio Codec (FLAC) Meridian Lossless Packing (MLP) Monkey's Audio (Monkey's Audio APE) MPEG-4 SLS (also known as HD-AAC) OptimFROG Original Sound Quality (OSQ) RealPlayer (RealAudio Lossless) Shorten (SHN) TTA (True Audio Lossless) WavPack (WavPack lossless) WMA Lossless (Windows Media Lossless) Raster graphics AVIF – AOMedia Video 1 Image File Format FLIF – Free Lossless Image Format HEIF – High Efficiency Image File Format (lossless or lossy compression, using HEVC) ILBM – (lossless RLE compression of Amiga IFF images) JBIG2 – (lossless or lossy compression of B&W images) JPEG 2000 – (includes lossless compression method via LeGall-Tabatabai 5/3 reversible integer wavelet transform) JPEG-LS – (lossless/near-lossless compression standard) JPEG XL – (lossless or lossy compression) JPEG XR – formerly WMPhoto and HD Photo, includes a lossless compression method LDCT – Lossless Discrete Cosine Transform PCX – PiCture eXchange PDF – Portable Document Format (lossless or lossy compression) PNG – Portable Network Graphics TGA – Truevision TGA TIFF – Tagged Image File Format (lossless or lossy compression) WebP – (lossless or lossy compression of RGB and RGBA images) 3D Graphics OpenCTM – Lossless compression of 3D triangle meshes Video See list of lossless video codecs Cryptography Cryptosystems often compress data (the "plaintext") before encryption for added security. When properly implemented, compression greatly increases the unicity distance by removing patterns that might facilitate cryptanalysis. However, many ordinary lossless compression algorithms produce headers, wrappers, tables, or other predictable output that might instead make cryptanalysis easier. Thus, cryptosystems must utilize compression algorithms whose output does not contain these predictable patterns. Genetics and Genomics Genetics compression algorithms (not to be confused with genetic algorithms) are the latest generation of lossless algorithms that compress data (typically sequences of nucleotides) using both conventional compression algorithms and specific algorithms adapted to genetic data. In 2012, a team of scientists from Johns Hopkins University published the first genetic compression algorithm that does not rely on external genetic databases for compression. HAPZIPPER was tailored for HapMap data and achieves over 20-fold compression (95% reduction in file size), providing 2- to 4-fold better compression much faster than leading general-purpose compression utilities. Genomic sequence compression algorithms, also known as DNA sequence compressors, explore the fact that DNA sequences have characteristic properties, such as inverted repeats. The most successful compressors are XM and GeCo. For eukaryotes XM is slightly better in compression ratio, though for sequences larger than 100 MB its computational requirements are impractical. Executables Self-extracting executables contain a compressed application and a decompressor. When executed, the decompressor transparently decompresses and runs the original application. This is especially often used in demo coding, where competitions are held for demos with strict size limits, as small as 1k. This type of compression is not strictly limited to binary executables, but can also be applied to scripts, such as JavaScript. Lossless compression benchmarks Lossless compression algorithms and their implementations are routinely tested in head-to-head benchmarks. There are a number of better-known compression benchmarks. Some benchmarks cover only the data compression ratio, so winners in these benchmarks may be unsuitable for everyday use due to the slow speed of the top performers. Another drawback of some benchmarks is that their data files are known, so some program writers may optimize their programs for best performance on a particular data set. The winners on these benchmarks often come from the class of context-mixing compression software. Matt Mahoney, in his February 2010 edition of the free booklet Data Compression Explained, additionally lists the following: The Calgary Corpus dating back to 1987 is no longer widely used due to its small size. Matt Mahoney maintained the Calgary Compression Challenge, created and maintained from May 21, 1996, through May 21, 2016, by Leonid A. Broukhis. The Large Text Compression Benchmark and the similar Hutter Prize both use a trimmed Wikipedia XML UTF-8 data set. The Generic Compression Benchmark, maintained by Matt Mahoney, tests compression of data generated by random Turing machines. Sami Runsas (the author of NanoZip) maintained Compression Ratings, a benchmark similar to Maximum Compression multiple file test, but with minimum speed requirements. It offered the calculator that allowed the user to weight the importance of speed and compression ratio. The top programs were fairly different due to the speed requirement. In January 2010, the top program was NanoZip followed by FreeArc, CCM, flashzip, and 7-Zip. The Monster of Compression benchmark by Nania Francesco Antonio tested compression on 1Gb of public data with a 40-minute time limit. In December 2009, the top ranked archiver was NanoZip 0.07a and the top ranked single file compressor was ccmx 1.30c. The Compression Ratings website published a chart summary of the "frontier" in compression ratio and time. The Compression Analysis Tool is a Windows application that enables end users to benchmark the performance characteristics of streaming implementations of LZF4, Deflate, ZLIB, GZIP, BZIP2 and LZMA using their own data. It produces measurements and charts with which users can compare the compression speed, decompression speed and compression ratio of the different compression methods and to examine how the compression level, buffer size and flushing operations affect the results. Limitations Lossless data compression algorithms (that do not attach compression id labels to their output data sets) cannot guarantee compression for all input data sets. In other words, for any lossless data compression algorithm, there will be an input data set that does not get smaller when processed by the algorithm, and for any lossless data compression algorithm that makes at least one file smaller, there will be at least one file that it makes larger. This is easily proven with elementary mathematics using a counting argument called the pigeonhole principle, as follows: Assume that each file is represented as a string of bits of some arbitrary length. Suppose that there is a compression algorithm that transforms every file into an output file that is no longer than the original file, and that at least one file will be compressed into an output file that is shorter than the original file. Let M be the least number such that there is a file F with length M bits that compresses to something shorter. Let N be the length (in bits) of the compressed version of F. Because N<M, every file of length N keeps its size during compression. There are 2N such files possible. Together with F, this makes 2N+1 files that all compress into one of the 2N files of length N. But 2N is smaller than 2N+1, so by the pigeonhole principle there must be some file of length N that is simultaneously the output of the compression function on two different inputs. That file cannot be decompressed reliably (which of the two originals should that yield?), which contradicts the assumption that the algorithm was lossless. We must therefore conclude that our original hypothesis (that the compression function makes no file longer) is necessarily untrue. Most practical compression algorithms provide an "escape" facility that can turn off the normal coding for files that would become longer by being encoded. In theory, only a single additional bit is required to tell the decoder that the normal coding has been turned off for the entire input; however, most encoding algorithms use at least one full byte (and typically more than one) for this purpose. For example, deflate compressed files never need to grow by more than 5 bytes per 65,535 bytes of input. In fact, if we consider files of length N, if all files were equally probable, then for any lossless compression that reduces the size of some file, the expected length of a compressed file (averaged over all possible files of length N) must necessarily be greater than N. So if we know nothing about the properties of the data we are compressing, we might as well not compress it at all. A lossless compression algorithm is useful only when we are more likely to compress certain types of files than others; then the algorithm could be designed to compress those types of data better. Thus, the main lesson from the argument is not that one risks big losses, but merely that one cannot always win. To choose an algorithm always means implicitly to select a subset of all files that will become usefully shorter. This is the theoretical reason why we need to have different compression algorithms for different kinds of files: there cannot be any algorithm that is good for all kinds of data. The "trick" that allows lossless compression algorithms, used on the type of data they were designed for, to consistently compress such files to a shorter form is that the files the algorithms are designed to act on all have some form of easily modeled redundancy that the algorithm is designed to remove, and thus belong to the subset of files that that algorithm can make shorter, whereas other files would not get compressed or even get bigger. Algorithms are generally quite specifically tuned to a particular type of file: for example, lossless audio compression programs do not work well on text files, and vice versa. In particular, files of random data cannot be consistently compressed by any conceivable lossless data compression algorithm; indeed, this result is used to define the concept of randomness in Kolmogorov complexity. It is provably impossible to create an algorithm that can losslessly compress any data. While there have been many claims through the years of companies achieving "perfect compression" where an arbitrary number N of random bits can always be compressed to N − 1 bits, these kinds of claims can be safely discarded without even looking at any further details regarding the purported compression scheme. Such an algorithm contradicts fundamental laws of mathematics because, if it existed, it could be applied repeatedly to losslessly reduce any file to length 1. On the other hand, it has also been proven that there is no algorithm to determine whether a file is incompressible in the sense of Kolmogorov complexity. Hence it is possible that any particular file, even if it appears random, may be significantly compressed, even including the size of the decompressor. An example is the digits of the mathematical constant pi, which appear random but can be generated by a very small program. However, even though it cannot be determined whether a particular file is incompressible, a simple theorem about incompressible strings shows that over 99% of files of any given length cannot be compressed by more than one byte (including the size of the decompressor). Mathematical background Abstractly, a compression algorithm can be viewed as a function on sequences (normally of octets). Compression is successful if the resulting sequence is shorter than the original sequence (and the instructions for the decompression map). For a compression algorithm to be lossless, the compression map must form an injection from "plain" to "compressed" bit sequences. The pigeonhole principle prohibits a bijection between the collection of sequences of length N and any subset of the collection of sequences of length N−1. Therefore, it is not possible to produce a lossless algorithm that reduces the size of every possible input sequence. Points of application in real compression theory Real compression algorithm designers accept that streams of high information entropy cannot be compressed, and accordingly, include facilities for detecting and handling this condition. An obvious way of detection is applying a raw compression algorithm and testing if its output is smaller than its input. Sometimes, detection is made by heuristics; for example, a compression application may consider files whose names end in ".zip", ".arj" or ".lha" uncompressible without any more sophisticated detection. A common way of handling this situation is quoting input, or uncompressible parts of the input in the output, minimizing the compression overhead. For example, the zip data format specifies the 'compression method' of 'Stored' for input files that have been copied into the archive verbatim. The Million Random Digit Challenge Mark Nelson, in response to claims of "magic" compression algorithms appearing in comp.compression, has constructed a 415,241 byte binary file of highly entropic content, and issued a public challenge of $100 to anyone to write a program that, together with its input, would be smaller than his provided binary data yet be able to reconstitute it without error. A similar challenge, with $5,000 as reward, was issued by Mike Goldman. See also Comparison of file archivers Data compression David A. Huffman Entropy (information theory) Grammar-based code Information theory Kolmogorov complexity List of codecs Lossless Transform Audio Compression (LTAC) Lossy compression Precompressor Universal code (data compression) Normal number References Further reading (790 pages) (488 pages) External links overview of US patent #7,096,360, "[a]n "Frequency-Time Based Data Compression Method" supporting the compression, encryption, decompression, and decryption and persistence of many binary digits through frequencies where each frequency represents many bits." Data compression Lossless compression algorithms	[ -0.3134649991989136, 0.3676743507385254, -0.2902301847934723, 0.16980084776878357, 0.10666733235120773, 0.22835713624954224, 0.2876533269882202, 0.30548304319381714, 0.07467898726463318, -0.4634374976158142, -1.0836808681488037, 0.5906769037246704, -0.25083380937576294, 0.3660871982574463,...
18210	https://en.wikipedia.org/wiki/Larry%20Niven	Larry Niven	Laurence van Cott Niven (; born April 30, 1938) is an American science fiction writer. His best-known works are Ringworld (1970), which received Hugo, Locus, Ditmar, and Nebula awards, and, with Jerry Pournelle, The Mote in God's Eye (1974) and Lucifer's Hammer (1977). The Science Fiction and Fantasy Writers of America named him the 2015 recipient of the Damon Knight Memorial Grand Master Award. His work is primarily hard science fiction, using big science concepts and theoretical physics. It also often includes elements of detective fiction and adventure stories. His fantasy includes the series The Magic Goes Away, rational fantasy dealing with magic as a non-renewable resource. Biography Niven was born in Los Angeles. He is a great-grandson of Edward L. Doheny, an oil tycoon who drilled the first successful well in the Los Angeles City Oil Field in 1892, and also was subsequently implicated in the Teapot Dome scandal. Niven briefly attended the California Institute of Technology and graduated with a Bachelor of Arts in mathematics (with a minor in psychology) from Washburn University in Topeka, Kansas in 1962. He also completed a year of graduate work in mathematics at the University of California, Los Angeles. On September 6, 1969, he married Marilyn Wisowaty, a science fiction and Regency literature fan. Work Niven is the author of numerous science fiction short stories and novels, beginning with his 1964 story "The Coldest Place". In this story, the coldest place concerned is the dark side of Mercury, which at the time the story was written was thought to be tidally locked with the Sun (it was found to rotate in a 2:3 resonance after Niven received payment for the story, but before it was published). Algis Budrys said in 1968 that Niven becoming a top writer despite the New Wave was evidence that "trends are for second-raters". In addition to the Nebula Award in 1970 and the Hugo and Locus awards in 1971 for Ringworld, Niven won the Hugo Award for Best Short Story for "Neutron Star" in 1967. He won the same award in 1972, for "Inconstant Moon", and in 1975 for "The Hole Man". In 1976, he won the Hugo Award for Best Novelette for "The Borderland of Sol". Niven has written scripts for three science fiction television series: the original Land of the Lost series; Star Trek: The Animated Series, for which he adapted his early story "The Soft Weapon"; and The Outer Limits, for which he adapted his story "Inconstant Moon" into an episode of the same name. Niven has also written for the DC Comics character Green Lantern, including in his stories hard science fiction concepts such as universal entropy and the redshift effect. He has included limited psi gifts (mind over matter) in some characters in his stories; like Gil Hamilton's psychic arm which can only reach as far as a corporeal arm could, though it can, for example, reach through solid materials and manipulate objects on the other side, and through videophone screens, or Matt Keller's ability to make people not notice him. Several of his stories predicted the black market in transplant organs ("organlegging"). Many of Niven's stories—sometimes called the Tales of Known Space—take place in his Known Space universe, in which humanity shares the several habitable star systems nearest to the Sun with over a dozen alien species, including the aggressive feline Kzinti and the very intelligent but cowardly Pierson's Puppeteers, which are frequently central characters. The Ringworld series is part of the Tales of Known Space, and Niven has shared the setting with other writers since a 1988 anthology, The Man-Kzin Wars (Baen Books, jointly edited with Jerry Pournelle and Dean Ing). There have been several volumes of short stories and novellas. Niven has also written a logical fantasy series The Magic Goes Away, which utilizes an exhaustible resource called mana to power a rule-based "technological" magic. The Draco Tavern series of short stories take place in a more light-hearted science fiction universe, and are told from the point of view of the proprietor of an omni-species bar. The whimsical Svetz series consists of a collection of short stories, The Flight of the Horse, and a novel, Rainbow Mars, which involve a nominal time machine sent back to retrieve long-extinct animals, but which travels, in fact, into alternative realities and brings back mythical creatures such as a roc and a unicorn. Much of his writing since the 1970s has been in collaboration, particularly with Jerry Pournelle and Steven Barnes, but also Brenda Cooper and Edward M. Lerner. Other works One of Niven's best known humorous works is "Man of Steel, Woman of Kleenex", in which he uses real-world physics to underline the difficulties of Superman and a human woman (Lois Lane or Lana Lang) mating. Influence In Niven's novel Ringworld, he envisions a Ringworld: a band of material, roughly a million miles wide, of approximately the same diameter as Earth's orbit, rotating around a star. The idea originated in Niven's attempts to imagine a more efficient version of a Dyson sphere, which could produce the effect of surface gravity through rotation. Given that spinning a Dyson sphere would result in the atmosphere pooling around the equator, the Ringworld removes all the extraneous parts of the structure, leaving a spinning band landscaped on the sun-facing side, with the atmosphere and inhabitants kept in place through centrifugal force and high perimeter walls (rim walls). After publication of Ringworld two friends, Dan Alderson and Ctein, told Niven that the Ringworld was dynamically unstable: if the center of rotation drifts away from the central sun, gravitational forces will not "re-center" it, thus allowing the ring to eventually contact the sun and be destroyed. Niven used this as a core plot element in the sequel novel, The Ringworld Engineers. This idea proved influential, serving as an alternative to a full Dyson sphere that required fewer assumptions (such as artificial gravity) and allowed a day/night cycle to be introduced (through the use of a smaller ring of "shadow squares", rotating between the ring and its sun). This was further developed by Iain M. Banks in his Culture series, which features about ringworld–size megastructures called Orbitals that orbit a star rather than encircling it entirely (actual "Rings" and Dyson "Spheres" are also mentioned but are much rarer). Alastair Reynolds also uses ringworlds in his 2008 novel House of Suns. The Ringworld-like namesake of the Halo video game series is the eponymous Halo megastructure/superweapon. In the Magic: The Gathering trading card game, the card Nevinyrral's Disk uses his name, spelled backwards. This tribute was paid because the game's system where mana from lands is used to power spells was inspired by his book The Magic Goes Away. The card Nevinyrral, Urborg Tyrant was added in Commander Legends, adding the Niven's namesake character fully to the game. Politics According to author Michael Moorcock, in 1967, Niven was among those Science Fiction Writers of America members who voiced opposition to the Vietnam War. However, in 1968 Niven's name appeared in a prowar advertisement in Galaxy Science Fiction. Niven was an adviser to Ronald Reagan on the creation of the Strategic Defense Initiative antimissile policy, as part of the Citizens' Advisory Council on National Space Policy—as covered in the BBC documentary Pandora's Box by Adam Curtis. In 2007, Niven, in conjunction with a think tank of science fiction writers known as SIGMA, founded and led by Dr. Arlan Andrews, Sr., began advising the U.S. Department of Homeland Security as to future trends affecting terror policy and other topics. Among those topics was reducing costs for hospitals to which Niven offered the solution to spread rumors in Latino communities that organs were being harvested illegally in hospitals. Niven's laws Larry Niven is also known in science fiction fandom for "Niven's Law": "There is no cause so right that one cannot find a fool following it." Over the course of his career Niven has added to this first law a list of Niven's Laws which he describes as "how the Universe works" as far as he can tell. Bibliography References External links Bibliography and works with bibliography Larry Niven at Fantastic Fiction Interviews Audio interview with Larry Niven 1938 births 20th-century American novelists 21st-century American novelists Activists from California American agnostics American anti–Vietnam War activists American comics writers American male novelists American science fiction writers Filkers Hugo Award-winning writers Inkpot Award winners Living people People from Los Angeles Nebula Award winners SFWA Grand Masters Writers from Los Angeles 20th-century American male writers 21st-century American male writers	[ -0.13257917761802673, 0.2306041419506073, -0.6168316602706909, -0.3714178204536438, 0.4919213354587555, 0.6745265126228333, -0.016110997647047043, 0.4965284466743469, -0.08349665999412537, -0.10976746678352356, -0.27464938163757324, 0.9018598198890686, -0.004998155403882265, 0.379648864269...
18212	https://en.wikipedia.org/wiki/Linux%20distribution	Linux distribution	A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one of the Linux distributions, which are available for a wide variety of systems ranging from embedded devices (for example, OpenWrt) and personal computers (for example, Linux Mint) to powerful supercomputers (for example, Rocks Cluster Distribution). A typical Linux distribution comprises a Linux kernel, GNU tools and libraries, additional software, documentation, a window system (the most common being the X Window System, or, more recently, Wayland), a window manager, and a desktop environment. Most of the included software is free and open-source software made available both as compiled binaries and in source code form, allowing modifications to the original software. Usually, Linux distributions optionally include some proprietary software that may not be available in source code form, such as binary blobs required for some device drivers. A Linux distribution may also be described as a particular assortment of application and utility software (various GNU tools and libraries, for example), packaged together with the Linux kernel in such a way that its capabilities meet the needs of many users. The software is usually adapted to the distribution and then packaged into software packages by the distribution's maintainers. The software packages are available online in repositories, which are storage locations usually distributed around the world. Beside glue components, such as the distribution installers (for example, Debian-Installer and Anaconda) or the package management systems, there are only very few packages that are originally written from the ground up by the maintainers of a Linux distribution. Almost one thousand Linux distributions exist. Because of the huge availability of software, distributions have taken a wide variety of forms, including those suitable for use on desktops, servers, laptops, netbooks, mobile phones and tablets, as well as minimal environments typically for use in embedded systems. There are commercially backed distributions, such as Fedora Linux (Red Hat), openSUSE (SUSE) and Ubuntu (Canonical Ltd.), and entirely community-driven distributions, such as Debian, Slackware, Gentoo and Arch Linux. Most distributions come ready to use and pre-compiled for a specific instruction set, while some distributions (such as Gentoo) are distributed mostly in source code form and compiled locally during installation. History Linus Torvalds developed the Linux kernel and distributed its first version, 0.01, in 1991. Linux was initially distributed as source code only, and later as a pair of downloadable floppy disk images one bootable and containing the Linux kernel itself, and the other with a set of GNU utilities and tools for setting up a file system. Since the installation procedure was complicated, especially in the face of growing amounts of available software, distributions sprang up to simplify this. Early distributions included the following: H. J. Lu's "Boot-root", the aforementioned disk image pair with the kernel and the absolute minimal tools to get started, in late 1991 MCC Interim Linux, which was made available to the public for download in February 1992 Softlanding Linux System (SLS), released in 1992, was the most comprehensive distribution for a short time, including the X Window System Yggdrasil Linux/GNU/X, a commercial distribution first released in December 1992 The two oldest and still active distribution projects started in 1993. The SLS distribution was not well maintained, so in July 1993 a new distribution, called Slackware and based on SLS, was released by Patrick Volkerding. Also dissatisfied with SLS, Ian Murdock set to create a free distribution by founding Debian, which had its first release in December 1993. Users were attracted to Linux distributions as alternatives to the DOS and Microsoft Windows operating systems on IBM PC compatible computers, Mac OS on the Apple Macintosh, and proprietary versions of Unix. Most early adopters were familiar with Unix from work or school. They embraced Linux distributions for their low (if any) cost, and availability of the source code for most or all of the software included. As of 2017, Linux has become more popular in server and embedded devices markets than in the desktop market. For example, Linux is used on over 50% of web servers, whereas its desktop market share is about 3.7%. Components Many Linux distributions provide an installation system akin to that provided with other modern operating systems. On the other hand, some distributions, including Gentoo Linux, provide only the binaries of a basic kernel, compilation tools, and an installer; the installer compiles all the requested software for the specific architecture of the user's computer, using these tools and the provided source code. Package management Distributions are normally segmented into packages. Each package contains a specific application or service. Examples of packages are a library for handling the PNG image format, a collection of fonts or a web browser. The package is typically provided as compiled code, with installation and removal of packages handled by a package management system (PMS) rather than a simple file archiver. Each package intended for such a PMS contains meta-information such as a package description, version, and "dependencies". The package management system can evaluate this meta-information to allow package searches, to perform an automatic upgrade to a newer version, to check that all dependencies of a package are fulfilled, and/or to fulfill them automatically. Although Linux distributions typically contain much more software than proprietary operating systems, it is normal for local administrators to also install software not included in the distribution. An example would be a newer version of a software application than that supplied with a distribution, or an alternative to that chosen by the distribution (for example, KDE Plasma Workspaces rather than GNOME or vice versa for the user interface layer). If the additional software is distributed in source-only form, this approach requires local compilation. However, if additional software is locally added, the "state" of the local system may fall out of synchronization with the state of the package manager's database. If so, the local administrator will be required to take additional measures to ensure the entire system is kept up to date. The package manager may no longer be able to do so automatically. Most distributions install packages, including the kernel and other core operating system components, in a predetermined configuration. Few now require or even permit configuration adjustments at first install time. This makes installation less daunting, particularly for new users, but is not always acceptable. For specific requirements, much software must be carefully configured to be useful, to work correctly with other software, or to be secure, and local administrators are often obliged to spend time reviewing and reconfiguring assorted software. Some distributions go to considerable lengths to specifically adjust and customize most or all of the software included in the distribution. Not all do so. Some distributions provide configuration tools to assist in this process. By replacing everything provided in a distribution, an administrator may reach a "distribution-less" state: everything was retrieved, compiled, configured, and installed locally. It is possible to build such a system from scratch, avoiding a distribution altogether. One needs a way to generate the first binaries until the system is self-hosting. This can be done via compilation on another system capable of building binaries for the intended target (possibly by cross-compilation). For example, see Linux From Scratch. Types and trends In broad terms, Linux distributions may be: Commercial or non-commercial Designed for enterprise users, power users, or for home users Supported on multiple types of hardware, or platform-specific, even to the extent of certification by the platform vendor Designed for servers, desktops, or embedded devices General purpose or highly specialized toward specific machine functionalities (e.g. firewalls, network routers, and computer clusters) Targeted at specific user groups, for example through language internationalization and localization, or through inclusion of many music production or scientific computing packages Built primarily for security, usability, portability, or comprehensiveness Standard release or rolling release, see below. The diversity of Linux distributions is due to technical, organizational, and philosophical variation among vendors and users. The permissive licensing of free software means that users with sufficient knowledge and interest can customize any existing distribution, or design one to suit their own needs. Rolling distributions Rolling Linux distributions are kept updated using small and frequent updates. The terms partially rolling and partly rolling (along with synonyms semi-rolling and half-rolling), fully rolling, truly rolling and optionally rolling are sometimes used by software developers and users. Repositories of rolling distributions usually contain very recent software releases – often the latest stable software releases available. They have pseudo-releases and installation media that are simply a snapshot of the software distribution at the time of the release of the installation image. Typically, a rolling release operating system installed from an older installation medium can be fully updated post-installation to a current state. Depending on the use case, there can be pros and cons to both standard release and rolling release software development methodologies. In terms of the software development process, standard releases require significant development effort being spent on keeping old versions up to date due to propagating bug fixes back to the newest branch, versus focusing more on the newest development branch. Also, unlike rolling releases, standard releases require more than one code branch to be developed and maintained, which increases the software development and software maintenance workload of the software developers and software maintainers. On the other hand, software features and technology planning are easier in standard releases due to a better understanding of upcoming features in the next version(s). Software release cycles can also be synchronized with those of major upstream software projects, such as desktop environments. As far as the user experience, standard releases are often viewed as more stable and bug-free since software conflicts can be more easily addressed and the software stack more thoroughly tested and evaluated, during the software development cycle. For this reason, they tend to be the preferred choice in enterprise environments and mission-critical tasks. However, rolling releases offer more current software which can also provide increased stability and fewer software bugs along with the additional benefits of new features, greater functionality, faster running speeds, and improved system and application security. Regarding software security, the rolling release model can have advantages in timely security updates, fixing system or application security bugs and vulnerabilities, that standard releases may have to wait till the next release for or patch in various versions. In a rolling release distribution, where the user has chosen to run it as a highly dynamic system, the constant flux of software packages can introduce new unintended vulnerabilities. Installation-free distributions (live CD/USB) A "live" distribution is a Linux distribution that can be booted from removable storage media such as optical discs or USB flash drives, instead of being installed on and booted from a hard disk drive. The portability of installation-free distributions makes them advantageous for applications such as demonstrations, borrowing someone else's computer, rescue operations, or as installation media for a standard distribution. When the operating system is booted from a read-only medium such as a CD or DVD, any user data that needs to be retained between sessions cannot be stored on the boot device but must be written to another storage device, such as a USB flash drive or a hard disk drive. Many Linux distributions provide a "live" form in addition to their conventional form, which is a network-based or removable-media image intended to be used only for installation; such distributions include SUSE, Ubuntu, Linux Mint, MEPIS and Fedora Linux. Some distributions, including Knoppix, Puppy Linux, Devil-Linux, SuperGamer, SliTaz GNU/Linux and dyne:bolic, are designed primarily for live use. Additionally, some minimal distributions can be run directly from as little space as one floppy disk without the need to change the contents of the system's hard disk drive. Examples The website DistroWatch lists many Linux distributions, and displays some of the ones that have the most web traffic on the site. The Wikimedia Foundation released an analysis of the browser User Agents of visitors to WMF websites until 2015, which includes details of the most popular Operating System identifiers, including some Linux distributions. Many of the popular distributions are listed below. Widely used GNU-based or GNU-compatible distributions Debian, a non-commercial distribution and one of the earliest, maintained by a volunteer developer community with a strong commitment to free software principles and democratic project management. Knoppix, the first Live CD distribution to run completely from removable media without installation to a hard disk, derived from Debian. Linux Mint Debian Edition (LMDE) uses Debian packages directly (rather than Ubuntu's) Ubuntu, a desktop and server distribution derived from Debian, maintained by British company Canonical Ltd. There are several distributions based on Ubuntu that mainly replace the GNOME stock desktop environment, like: Kubuntu based on KDE, Lubuntu based on LXQT, Xubuntu based on XFCE, Ubuntu MATE based on MATE, Ubuntu Budgie based on Budgie. Other official forks have specific uses like: Ubuntu Kylin for Chinese-speaking users, or Ubuntu Studio for media content creators. Linux Mint, a distribution based on and compatible with Ubuntu. Supports multiple desktop environments, among others GNOME Shell fork Cinnamon and GNOME 2 fork MATE. Fedora Linux, a community distribution sponsored by American company Red Hat and the successor to the company's previous offering, Red Hat Linux. It aims to be a technology testbed for Red Hat's commercial Linux offering, where new open-source software is prototyped, developed, and tested in a communal setting before maturing into Red Hat Enterprise Linux. Red Hat Enterprise Linux (RHEL), a derivative of Fedora Linux, maintained and commercially supported by Red Hat. It seeks to provide tested, secure, and stable Linux server and workstation support to businesses. CentOS, a distribution derived from the same sources used by Red Hat, maintained by a dedicated volunteer community of developers with both 100% Red Hat-compatible versions and an upgraded version that is not always 100% upstream compatible. Oracle Linux, which is a derivative of Red Hat Enterprise Linux, maintained and commercially supported by Oracle Mandriva Linux was a Red Hat Linux derivative popular in several European countries and Brazil, backed by the French company of the same name. After the company went bankrupt, it was superseded by OpenMandriva Lx, although a number of derivatives now have a larger user base. Mageia, a community fork of Mandriva Linux created in 2010 PCLinuxOS, a derivative of Mandriva, which grew from a group of packages into a community-spawned desktop distribution openSUSE, a community distribution mainly sponsored by German company SUSE. SUSE Linux Enterprise, derived from openSUSE, maintained and commercially supported by SUSE Arch Linux, a rolling release distribution targeted at experienced Linux users and maintained by a volunteer community, offers official binary packages and a wide range of unofficial user-submitted source packages. Packages are usually defined by a single PKGBUILD text file. Manjaro Linux, a derivative of Arch Linux that includes a graphical installer and other ease-of-use features for less experienced Linux users. Gentoo, a distribution targeted at power users, known for its FreeBSD Ports-like automated system for compiling applications from source code Slackware, created in 1993, one of the first Linux distributions and among the earliest still maintained, committed to remain highly Unix-like and easily modifiable by end users Linux kernel based operating systems Android, Google's commercial operating system based on Android OSP that runs on many devices such as smart phones, smart TVs, set-top boxes. Chrome OS, Google's commercial operating system based on Chromium OS that only runs on Chromebooks, Chromeboxes and tablet computers. Like Android, it has the Google Play Store and other Google apps. Support for applications that require GNU compatibility is available through a virtual machine called Crostini and referred to by Google as Linux support, see Chromebook#Integration with Linux. Whether the above operating systems count as a "Linux distribution" is a controversial topic. They use the Linux kernel, so the Linux Foundation and Chris DiBona, Google's open-source chief, agree that Android is a Linux distribution; others, such as Google engineer Patrick Brady, disagree by noting the lack of support for many GNU tools in Android, including glibc. Other Linux kernel based operating systems include Cyanogenmod, its fork LineageOS, Android-x86 and recently Tizen, Mer/Sailfish OS and KaiOS. Lightweight distributions Lightweight Linux distributions are those that have been designed with support for older hardware in mind, allowing older hardware to still be used productively, or, for maximum possible speed in newer hardware by leaving more resources available for use by applications. Examples include Tiny Core Linux, Puppy Linux and Slitaz. Niche distributions Other distributions target specific niches, such as: Routers for example, targeted by the tiny embedded router distribution OpenWrt Internet of things for example, targeted by Ubuntu Core Home theater PCs for example, targeted by KnoppMyth, Kodi (former XBMC) and Mythbuntu Specific platforms for example, Raspberry Pi OS targets the Raspberry Pi platform Education examples are Edubuntu and Karoshi, server systems based on PCLinuxOS Scientific computer servers and workstations for example, targeted by Scientific Linux Digital audio workstations for music production for example, targeted by Ubuntu Studio Computer Security, digital forensics and penetration testing examples are Kali Linux and Parrot Security OS Privacy and anonymity for example, targeted by Tails, Whonix, Qubes, or FreedomBox Offline use for example, Endless OS Microsoft's Azure Sphere Interdistribution issues The Free Standards Group is an organization formed by major software and hardware vendors that aims to improve interoperability between different distributions. Among their proposed standards are the Linux Standard Base, which defines a common ABI and packaging system for Linux, and the Filesystem Hierarchy Standard which recommends a standard filenaming chart, notably the basic directory names found on the root of the tree of any Linux filesystem. Those standards, however, see limited use, even among the distributions developed by members of the organization. The diversity of Linux distributions means that not all software runs on all distributions, depending on what libraries and other system attributes are required. Packaged software and software repositories are usually specific to a particular distribution, though cross-installation is sometimes possible on closely related distributions. Tools for choosing a distribution The process of constantly switching between distributions is often referred to as "distro hopping". Virtual machines such as VirtualBox and VMware Workstation virtualize hardware allowing users to test live media on a virtual machine. Some websites like DistroWatch offer lists of distributions, and link to screenshots of operating systems as a way to get a first impression of various distributions. There are tools available to help people select an appropriate distribution, such as several versions of the Linux Distribution Chooser, and the universal package search tool whohas. There are easy ways to try out several Linux distributions before deciding on one: Multi Distro is a Live CD that contains nine space-saving distributions. Installation There are several ways to install a Linux distribution. The most common method of installing Linux is by booting from a live USB memory stick, which can be created by using a USB image writer application and the ISO image, which can be downloaded from the various Linux distribution websites. DVD disks, CD disks, network installations and even other hard drives can also be used as "installation media". In the 1990s Linux distributions were installed using sets of floppies but this has been abandoned by all major distributions. By the 2000s many distributions offered CD and DVD sets with the vital packages on the first disc and less important packages on later ones. Some distributions, such as Debian also enabled installation over a network after booting from either a set of floppies or a CD with only a small amount of data on it. New users tend to begin by partitioning a hard drive in order to keep their previously installed operating system. The Linux distribution can then be installed on its own separate partition without affecting previously saved data. In a Live CD setup, the computer boots the entire operating system from CD without first installing it on the computer's hard disk. Many distributions have a Live CD installer, where the computer boots the operating system from the disk, and it can then be installed on the computer's hard disk, providing a seamless transition from the OS running from the CD to the OS running from the hard disk. Both servers and personal computers that come with Linux already installed are available from vendors including Hewlett-Packard, Dell and System76. On embedded devices, Linux is typically held in the device's firmware and may or may not be consumer-accessible. Anaconda, one of the more popular installers, is used by Red Hat Enterprise Linux, Fedora (which uses the Fedora Media Writer) and other distributions to simplify the installation process. Debian, Ubuntu and many others use Debian-Installer. Installation via an existing operating system Some distributions let the user install Linux on top of their current system, such as WinLinux or coLinux. Linux is installed to the Windows hard disk partition, and can be started from inside Windows itself. Virtual machines (such as VirtualBox or VMware) also make it possible for Linux to be run inside another OS. The VM software simulates a separate computer onto which the Linux system is installed. After installation, the virtual machine can be booted as if it were an independent computer. Various tools are also available to perform full dual-boot installations from existing platforms without a CD, most notably: The (now deprecated) Wubi installer, which allows Windows users to download and install Ubuntu or its derivatives into a FAT32 or an NTFS partition without an installation CD, allowing users to easily dual boot between either operating system on the same hard drive without losing data. Replaced by Ubiquity. Win32-loader, which is in the process of being integrated in official Debian CDs/DVDs, and allows Windows users to install Debian without a CD, though it performs a network installation and thereby requires repartitioning UNetbootin, which allows Windows and Linux users to perform similar no-CD network installations for a wide variety of Linux distributions and additionally provides live USB creation support Proprietary software Some specific proprietary software products are not available in any form for Linux. As of September 2015, the Steam gaming service has 1,500 games available on Linux, compared to 2,323 games for Mac and 6,500 Windows games. Emulation and API-translation projects like Wine and CrossOver make it possible to run non-Linux-based software on Linux systems, either by emulating a proprietary operating system or by translating proprietary API calls (e.g., calls to Microsoft's Win32 or DirectX APIs) into native Linux API calls. A virtual machine can also be used to run a proprietary OS (like Microsoft Windows) on top of Linux. OEM contracts Computer hardware is usually sold with an operating system other than Linux already installed by the original equipment manufacturer (OEM). In the case of IBM PC compatibles the OS is usually Microsoft Windows; in the case of Apple Macintosh computers it has always been a version of Apple's OS, currently macOS; Sun Microsystems sold SPARC hardware with the Solaris installed; video game consoles such as the Xbox, PlayStation, and Wii each have their own proprietary OS. This limits Linux's market share: consumers are unaware that an alternative exists, they must make a conscious effort to use a different operating system, and they must either perform the actual installation themselves, or depend on support from a friend, relative, or computer professional. However, it is possible to buy hardware with Linux already installed. Lenovo, Hewlett-Packard, Dell, Affordy, Purism, Pine64 and System76 all sell general-purpose Linux laptops. Custom-order PC manufacturers will also build Linux systems, but possibly with the Windows key on the keyboard. Fixstars Solutions (formerly Terra Soft) sells Macintosh computers and PlayStation 3 consoles with Yellow Dog Linux installed. It is more common to find embedded devices sold with Linux as the default manufacturer-supported OS, including the Linksys NSLU2 NAS device, TiVo's line of personal video recorders, and Linux-based cellphones (including Android smartphones), PDAs, and portable music players. The current Microsoft Windows license lets the manufacturer determine the refund policy. With previous versions of Windows, it was possible to obtain a refund if the manufacturer failed to provide the refund by litigation in the small claims courts. On February 15, 1999, a group of Linux users in Orange County, California held a "Windows Refund Day" protest in an attempt to pressure Microsoft into issuing them refunds. In France, the Linuxfrench and AFUL (French speaking Libre Software Users' Association) organizations along with free software activist Roberto Di Cosmo started a "Windows Detax" movement, which led to a 2006 petition against "racketiciels" (translation: Racketware) with 39,415 signatories and the DGCCRF branch of the French government filing several complaints against bundled software. On March 24, 2014, a new international petition was launched by AFUL on the Avaaz platform, translated into several languages and supported by many organizations around the world. Statistics There are no official figures on popularity, adoption, downloads or installed base of Linux distributions. There are also no official figures for the total number of Linux systems, partly due to the difficulty of quantifying the number of PCs running Linux (see Desktop Linux adoption), since many users download Linux distributions. Hence, the sales figures for Linux systems and commercial Linux distributions indicate a much lower number of Linux systems and level of Linux adoption than is the case; this is mainly due to Linux being free and open-source software that can be downloaded free of charge. A Linux Counter Project had kept track of a running guesstimate of the number of Linux systems, but did not distinguish between rolling release and standard release distributions. It ceased operation in August 2018, though a few related blog posts were created through October 2018. Desktop usage statistical reports for particular Linux distributions have been collected and published since July 2014 by the Linux Hardware Project. See also Comparison of Linux distributions Light-weight Linux distribution List of Linux distributions References External links The LWN.net Linux Distribution List – a categorized list with information about each entry List of GNU/Linux distributions considered free by the Free Software Foundation Google's approach to a large-scale live upgrading between two widely different Linux distributions: presentation and text version, LinuxCon 2013, by Marc Merlin Rolling release vs. fixed release Linux, ZDNet, February 3, 2015, by Steven J. Vaughan-Nichols DistroTest - test any Linux Distro without installing Linus Torvalds	[ 0.2111472487449646, -0.09202892333269119, -0.27062028646469116, 0.035042569041252136, 0.14332756400108337, -0.2501620054244995, -0.2956332266330719, 0.5909620523452759, -0.19565564393997192, -0.27966174483299255, -0.9069188237190247, 0.46190088987350464, -0.5252112150192261, 0.295905441045...
18213	https://en.wikipedia.org/wiki/Los%20Angeles%20Dodgers	Los Angeles Dodgers	The Los Angeles Dodgers are an American professional baseball team based in Los Angeles. The Dodgers compete in Major League Baseball (MLB) as a member club of the National League (NL) West division. Established in 1883 in the city of Brooklyn, which later became a borough of New York City, the team joined the NL in 1890 as the Brooklyn Bridegrooms and assumed several different monikers thereafter before finally settling on the name Dodgers in 1932. From the 1940s through the mid-1950s, the Dodgers developed a fierce cross-town rivalry with the New York Yankees as the two clubs faced each other in the World Series seven times, with the Dodgers losing the first five matchups before defeating them to win the franchise's first title in 1955. It was also during this period that the Dodgers made history by breaking the baseball color line in 1947 with the debut of Jackie Robinson, the first African-American to play in the Major Leagues since 1884. Another major milestone was reached in 1956 when Don Newcombe became the first player ever to win both the Cy Young Award and the NL MVP in the same season. After 68 seasons in Brooklyn, Dodgers owner and president Walter O'Malley relocated the franchise to Los Angeles before the 1958 season. The team played their first four seasons at the Los Angeles Memorial Coliseum before moving to their current home of Dodger Stadium in 1962. The Dodgers found immediate success in Los Angeles by winning the 1959 World Series, representing the franchise's first championship since moving to Los Angeles. Success continued into the 1960s with their one-two punch ace pitchers Sandy Koufax and Don Drysdale being the cornerstones of two more titles in 1963 and 1965. During the 1980s, Mexican phenom pitcher Fernando Valenzuela quickly became a sensation—affectionately referred to as "Fernandomania"—when he led the team as a rookie to another championship in 1981. Valenzuela became the first and, to date, the only player to ever win the Cy Young and Rookie of the Year awards in the same season. The Dodgers were once again victorious in 1988, upsetting their heavily favored opponent in each series and becoming the first and only franchise to win multiple titles in the 80s. After a 32-year drought, which included 12 postseason appearances in a 17-year span and eight consecutive division titles from 2013 to 2020, the Dodgers won the 2020 World Series. One of the most successful and storied franchises in MLB, the Dodgers have won seven World Series championships and a record 24 National League pennants. Eleven NL MVP award winners have played for the Dodgers, winning a total of 14. Eight Cy Young Award winners have pitched for the club, winning a total of 12—by far the most of any Major League franchise. Additionally, the Dodgers boast 18 Rookie of the Year Award winners—twice as many as the next club. This includes four consecutive Rookies of the Year from 1979 to 1982 and five consecutive from 1992 to 1996. From 1884 through 2021, the Dodgers' all-time record is 11,123–9,891 (). Today, the Dodgers are among the most popular MLB teams, enjoying large fan support both at home and on the road. They maintain a fierce rivalry with the San Francisco Giants dating back to when the two clubs were based in New York City. As of 2021, Forbes ranks the Dodgers second in MLB franchise valuation at $3.57 billion. History In the early 20th century, the team, then sometimes called the Brooklyn Robins after manager Wilbert Robinson, won league pennants in 1916 and 1920, losing the World Series both times, first to Boston and then Cleveland. In the 1930s, the team officially adopted the Dodgers nickname, which had been in use since the 1890s, named after the Brooklyn pedestrians who dodged the streetcars in the city. In 1941, the Dodgers captured their third National League pennant, only to lose to the New York Yankees. This marked the onset of the Dodgers–Yankees rivalry, as the Dodgers would face them in their next six World Series appearances. Led by Jackie Robinson, the first black Major League Baseball player of the modern era; and three-time National League Most Valuable Player Roy Campanella, also signed out of the Negro leagues, the Dodgers captured their first World Series title in 1955 by defeating the Yankees for the first time, a story notably described in the 1972 book The Boys of Summer. Following the 1957 season the team left Brooklyn. In just their second season in Los Angeles, the Dodgers won their second World Series title, beating the Chicago White Sox in six games in 1959. Spearheaded by the dominant pitching style of Sandy Koufax and Don Drysdale, the Dodgers captured three pennants in the 1960s and won two more World Series titles, sweeping the Yankees in four games in 1963, and edging the Minnesota Twins in seven in 1965. The 1963 sweep was their second victory against the Yankees, and their first against them as a Los Angeles team. The Dodgers won four more pennants in 1966, 1974, 1977 and 1978, but lost in each World Series appearance. They went on to win the World Series again in 1981, thanks in part to pitching sensation Fernando Valenzuela. The early 1980s were affectionately dubbed "Fernandomania." In 1988, another pitching hero, Orel Hershiser, again led them to a World Series victory, aided by one of the most memorable home runs of all time by their star outfielder Kirk Gibson coming off the bench, despite having injuries to both knees, to pinch-hit with two outs in the bottom of the ninth inning of game 1, in his only appearance of the series. The Dodgers won the pennant in 2017 for the first time since their world series victory in 1988, aided by a Justin Turner walk-off home run on the same night of Gibson's iconic walk-off home run 29 years earlier. They went on to face the Houston Astros and lose in 7 games; however, the series became embroiled in controversy due to the Houston Astros sign stealing scandal. The Dodgers won the pennant in 2018 for a second year in a row, moving on to lose to the Boston Red Sox in 5 games. They went on to win the World Series again in 2020 by defeating the Tampa Bay Rays in 6 games, after playing a season shortened to 60 games due to the COVID-19 pandemic. The Dodgers share a fierce rivalry with the San Francisco Giants, dating back to when the two franchises played in New York City. Both teams moved west for the 1958 season. The Brooklyn/Los Angeles Dodgers have appeared in the World Series 21 times, while the New York/San Francisco Giants have appeared in the World Series 20 times. The Giants have won one more World Series (8); when the two teams were based in New York, the Giants won five World Series championships, and the Dodgers one. After the move to California, the Dodgers have won six World Series while the Giants have won three. In Brooklyn, the Dodgers won the NL pennant twelve times (1890, 1899, 1900, 1916, 1920, 1941, 1947, 1949, 1952, 1953, 1955, 1956) and the World Series in 1955. After moving to Los Angeles, the team won National League pennants in 1959, 1963, 1965, 1966, 1974, 1977, 1978, 1981, 1988, 2017, 2018, and 2020, with World Series championships in 1959, 1963, 1965, 1981, 1988, and 2020. In all, the Dodgers have appeared in 21 World Series: 9 in Brooklyn and 12 in Los Angeles. Team history Brooklyn Dodgers The Dodgers were founded in 1883 as the Brooklyn Atlantics, borrowing the name of a defunct team that had played in Brooklyn before them. The team joined the American Association in 1884 and won the AA championship in 1889 before joining the National League in 1890. They promptly won the NL Championship their first year in the League. The team was known alternatively as the Bridegrooms, Grooms, Superbas, Robins, and Trolley Dodgers before officially becoming the Brooklyn Dodgers in the 1930s. Jackie Robinson For most of the first half of the 20th century, no Major League Baseball team employed an African American player. Jackie Robinson became the first African American to play for a Major League Baseball team when he played his first major league game on April 15, 1947, as a member of the Brooklyn Dodgers. This was mainly due to general manager Branch Rickey's efforts. The deeply religious Rickey's motivation appears to have been primarily moral, although business considerations were also a factor. Rickey was a member of The Methodist Church, the antecedent denomination to The United Methodist Church of today, which was a strong advocate for social justice and active later in the American Civil Rights Movement. This event was the harbinger of the integration of professional sports in the United States, the concomitant demise of the Negro leagues, and is regarded as a key moment in the history of the American Civil Rights Movement. Robinson was an exceptional player, a speedy runner who sparked the team with his intensity. He was the inaugural recipient of the Rookie of the Year award, which is now named the Jackie Robinson Award in his honor. The Dodgers' willingness to integrate, when most other teams refused to, was a key factor in their 1947–1956 success. They won six pennants in those 10 years with the help of Robinson, three-time MVP Roy Campanella, Cy Young Award winner Don Newcombe, Jim Gilliam and Joe Black. Robinson would eventually go on to become the first African-American elected to the Baseball Hall of Fame in 1962. Move to California Real estate investor Walter O'Malley acquired majority ownership of the Dodgers in 1950, when he bought the 25 percent share of co-owner Branch Rickey and became allied with the widow of another equal partner, Mrs. John L. Smith. Shortly afterwards, he was working to buy new land in Brooklyn to build a more accessible and profitable ballpark than the aging Ebbets Field. Beloved as it was, Ebbets Field was no longer well-served by its aging infrastructure and the Dodgers could no longer sell out the park even in the heat of a pennant race, despite largely dominating the National League from 1946 to 1957. O'Malley wanted to build a new, state-of-the-art stadium in Brooklyn. But City Planner Robert Moses and New York politicians refused to grant him the eminent domain authority required to build pursuant to O'Malley's plans. To put pressure on the city, during the 1955 season, O'Malley announced that the team would play seven regular-season games and one exhibition game at Jersey City's Roosevelt Stadium in 1956. Moses and the City considered this an empty threat, and did not believe O'Malley would go through with moving the team from New York City. After teams began to travel to and from games by air instead of train, it became possible to include locations in the far west. Los Angeles officials attended the 1956 World Series looking to the Washington Senators to move to the West Coast. When O'Malley heard that LA was looking for a club, he sent word to the Los Angeles officials that he was interested in talking. LA offered him what New York would not: a chance to buy land suitable for building a ballpark, and own that ballpark, giving him complete control over all revenue streams. When the news came out, NYC Mayor Robert F. Wagner, Jr. and Moses made an offer to build a ballpark on the World's Fair Grounds in Queens that would be shared by the Giants and Dodgers. However, O'Malley was interested in his park under only his conditions, and the plans for a new stadium in Brooklyn seemed like a pipe dream. O'Malley decided to move the Dodgers to California, convincing Giants owner Horace Stoneham to move to San Francisco instead of Minneapolis to keep the Giants-Dodgers rivalry alive on the West Coast. The Dodgers played their final game at Ebbets Field on September 24, 1957, which the Dodgers won 2–0 over the Pittsburgh Pirates. New York remained a one-team town with the New York Yankees until 1962, when Joan Payson founded the New York Mets and brought National League baseball back to the city. The blue background used by the Dodgers was adopted by the Mets, honoring their New York NL forebears with a blend of Dodgers blue and Giants orange. Los Angeles Dodgers The Dodgers were the first Major League Baseball team to ever play in Los Angeles. On April 18, 1958, the Dodgers played their first LA game, defeating the former New York and now new San Francisco Giants, 6–5, before 78,672 fans at the Los Angeles Memorial Coliseum. Catcher Roy Campanella, left partially paralyzed in an off-season accident, was never able to play in Los Angeles. Construction on Dodger Stadium was completed in time for Opening Day 1962. With its clean, simple lines and its picturesque setting amid hills and palm trees, the ballpark quickly became an icon of the Dodgers and their new California lifestyle. O'Malley was determined that there would not be a bad seat in the house, achieving this by cantilevered grandstands that have since been widely imitated. More importantly for the team, the stadium's spacious dimensions, along with other factors, gave defense an advantage over offense and the Dodgers moved to take advantage of this by assembling a team that would excel with its pitching. Since moving to Los Angeles, the Dodgers have won 12 more National League Championships and six more World Series rings. Other historical notes Historical records and firsts First baseball team to win championships in different leagues in consecutive years (1889–1890) First television broadcast (1939) First use of batting helmets (1941) First MLB team to employ and start an African-American player in the 20th century (Jackie Robinson, 1947) First MLB team to have numbers on the front of their uniforms (1952) First West Coast team (1958) – along with the San Francisco Giants First Western team to win a World Series (1959) First MLB team to allow a female sports journalist into a locker room (Anita Martini, 1974) First MLB team to establish a baseball academy in the Dominican Republic when they opened the doors to Campo Las Palmas (1987) Largest home-opener attendance: 78,672 (1958) (since broken by the Colorado Rockies in 1993) Largest single game attendance: 93,103 (1959) and 115,300 (2008) *World Record First MLB team to open an office in Asia (1998) Longest MLB record for home start going 13–0 (2009) North American record for the buying of a sports team ($2 billion, 2012) Most no-hitters (26) Most Cy Young award winners (12) First MLB team to employ a female lead trainer (Sue Falsone, 2012) 11,000 franchise wins 8-30-2020 (vs Texas) Most runs scored in a single inning of a postseason game (11 runs in 2020 NLCS Game 3, 2020) Most Rookie of the Year awards (18) First team to draw 3 million fans First team to have a pair of two-slam games in a season (2021) Origin of the nickname The Dodgers' official history reports that the term "Trolley Dodgers" was attached to the Brooklyn ballclub due to the complex maze of trolley cars that weaved its way through the borough of Brooklyn. In 1892, the city of Brooklyn (Brooklyn was an independent city until annexed by New York City in 1898) began replacing its slow-moving, horse-drawn trolley lines with the faster, more powerful electric trolley lines. Within less than three years, by the end of 1895, electric trolley accidents in Brooklyn had resulted in more than 130 deaths and maimed well over 500 people. Brooklyn's high profile, the significant number of widely reported accidents, and a trolley strike in early 1895, combined to create a strong association in the public's mind between Brooklyn and trolley dodging. Sportswriters started using the name "Trolley Dodgers" to refer to the Brooklyn team early in the 1895 season. The name was shortened to, on occasion, the "Brooklyn Dodgers" as early as 1898. Sportswriters in the early 20th century began referring to the Dodgers as the "Bums", in reference to the team's fans and possibly because of the "street character" nature of Jack Dawkins, the "Artful Dodger" in Charles Dickens' Oliver Twist. Newspaper cartoonist Willard Mullin used a drawing of famous clown Emmett Kelly to depict "Dem Bums": the team would later use "Weary Willie" in promotional images, and Kelly himself was a club mascot during the 1950s. Other team names used by the franchise were the Atlantics, Grays, Grooms, Bridegrooms, Superbas and Robins. All of these nicknames were used by fans and sportswriters to describe the team, but not in any official capacity. The team's legal name was the Brooklyn Base Ball Club. However, the Trolley Dodger nickname was used throughout this period, simultaneously with these other nicknames, by fans and sportswriters of the day. The team did not use the name in any formal sense until 1932, when the word "Dodgers" appeared on team jerseys. The "conclusive shift" came in 1933, when both home and road jerseys for the team bore the name "Dodgers". Examples of how the many popularized names of the team were used are available from newspaper articles before 1932. A New York Times article describing a game in 1916 starts out: "Jimmy Callahan, pilot of the Pirates, did his best to wreck the hopes the Dodgers have of gaining the National League pennant", but then goes on to comment: "the only thing that saved the Superbas from being toppled from first place was that the Phillies lost one of the two games played". What is interesting about the use of these two nicknames is that most baseball statistics sites and baseball historians generally now refer to the pennant-winning 1916 Brooklyn team as the Robins. A 1918 New York Times article uses the nickname in its title: "Buccaneers Take Last From Robins", but the subtitle of the article reads: "Subdue The Superbas By 11 To 4, Making Series An Even Break". Another example of the use of the many nicknames is found on the program issued at Ebbets Field for the 1920 World Series, which identifies the matchup in the series as "Dodgers vs. Indians" despite the fact that the Robins nickname had been in consistent use for around six years. The "Robins" nickname was derived from the name of their Hall of Fame manager, Wilbert Robinson, who led the team from 1914 to 1931. Uniforms The Dodgers' uniform has remained relatively unchanged since the 1930s. The home jersey is white with "Dodgers" written in script across the chest in royal. The road jersey is gray with "Los Angeles" written in script across the chest in royal. The word "Dodgers" was first used on the front of the team's home jersey in 1933; the uniform was then white with red pinstripes and a stylized "B" on the left shoulder. The Dodgers also wore green outlined uniforms and green caps throughout the 1937 season but reverted to blue the following year. The current design was created in 1939, and has remained the same ever since with only cosmetic changes. Originally intended for the 1951 World Series for which the ballclub failed to qualify, red numbers under the "Dodgers" script were added to the home uniform in 1952. The road jersey also has a red uniform number under the script. When the franchise moved from Brooklyn to Los Angeles, the city name on the road jersey changed, and the stylized "B" was replaced with the interlocking "LA" on the caps in 1958. In 1970, the Dodgers removed the city name from the road jerseys and had "Dodgers" on both the home and away uniforms. The city script returned to the road jerseys in 1999, and the tradition-rich Dodgers flirted with an alternate uniform for the first time since 1944 (when all-blue satin uniforms were introduced). These 1999 alternate jerseys had a royal top with the "Dodgers" script in white across the chest, and the red number on the front. These were worn with white pants and a new cap with silver brim, top button and Dodger logo. These alternates proved unpopular and the team abandoned them after only one season. In 2014, the Dodgers introduced an alternate road jersey: a gray version with the "Dodgers" script instead of the city name. Since its introduction, however, the road jersey with the "Dodgers" script was used more often than the road jersey with the "Los Angeles" script, so much that the team now considers it as a primary road uniform. In 2018, the Dodgers wore their 60th anniversary patch to honor the 60 years of being in Los Angeles. Asian players The Dodgers have been groundbreaking in their signing of players from Asia; mainly Japan, South Korea, and Taiwan. Former owner Peter O'Malley began reaching out in 1980 by starting clinics in China and South Korea, building baseball fields in two Chinese cities, and in 1998 becoming the first major league team to open an office in Asia. The Dodgers were the second team to start a Japanese player in recent history, pitcher Hideo Nomo, the first team to start a South Korean player, pitcher Chan Ho Park, and the first Taiwanese player, Chin-Feng Chen. In addition, they were the first team to send out three Asian pitchers, from different Asian countries, in one game: Park, Hong-Chih Kuo of Taiwan, and Takashi Saito of Japan. In the 2008 season, the Dodgers had the most Asian players on its roster of any major league team with five. They included Japanese pitchers Takashi Saito and Hiroki Kuroda; South Korean pitcher Chan Ho Park; and Taiwanese pitcher Hong-Chih Kuo and infielder Chin-Lung Hu. In 2005, the Dodgers' Hee Seop Choi became the first Asian player to compete in the Home Run Derby. For the 2013 season, the Dodgers signed starting pitcher Hyun-Jin Ryu with a six-year, $36 million contract, after posting a bid of nearly $27 million to acquire him from the KBO's Hanhwa Eagles. For the 2016 season, the Dodgers signed starting pitcher Kenta Maeda with an eight-year, $25 million contract, after posting a bid of $20 million to acquire him from the NPB's Hiroshima Toyo Carp. Rivalries The Dodgers' rivalry with the San Francisco Giants dates back to the 19th century, when the two teams were based in New York; the rivalry with the New York Yankees took place when the Dodgers were based in New York, but was revived with their East Coast/West Coast World Series battles in 1963, 1977, 1978, and 1981. The Dodgers rivalry with the Philadelphia Phillies also dates back to their days in New York, but was most fierce during the 1970s, 1980s, and 2000s. The Dodgers also had a heated rivalry with the Cincinnati Reds during the 1970s, 1980s and early 1990s. The intra-city rivalry with the Los Angeles Angels dates back to the Angels' inaugural season in 1961. San Francisco Giants The Dodgers–Giants rivalry is one of the longest-standing rivalries in U.S. baseball. The feud between the Dodgers and the San Francisco Giants began in the late 19th century when both clubs were based in New York City, with the Dodgers playing in Brooklyn and the Giants playing at the Polo Grounds in Manhattan. After the 1957 season, Dodgers owner Walter O'Malley moved the team to Los Angeles for financial and other reasons. Along the way, he managed to convince Giants owner Horace Stoneham—who was considering moving his team to Minnesota—to preserve the rivalry by bringing his team to California as well. New York baseball fans were stunned and heartbroken by the move. Given that the cities of Los Angeles and San Francisco have been bitter rivals in economic, cultural, and political arenas for over a century and a half, the new venue in California became fertile ground for its transplantation. Each team's ability to endure for over a century while moving across an entire continent, as well as the rivalry's leap from a cross-city to a cross-state engagement, have led to the rivalry being considered one of the greatest in American sports history. Unlike many other historic baseball match-ups in which one team remains dominant for most of their history, the Dodgers–Giants rivalry has exhibited a persistent balance in the respective successes of the two teams. While the Giants have more wins in franchise history, the Dodgers have the most National League pennants at 24, with the Giants following close behind at 23. The Giants have won eight World Series titles, while the Dodgers have won seven. The 2010 World Series was the Giants' first championship since moving to California, while the Dodgers had won six World Series titles since their move, their last title coming in the 2020 World Series. Los Angeles Angels This rivalry refers to a series of games played with the Los Angeles Angels. The Freeway Series takes its name from the massive freeway system in the greater Los Angeles metropolitan area, the home of both teams; one could travel from one team's stadium to the other simply by traveling along Interstate 5. The term is akin to Subway Series which refers to meetings between New York City baseball teams. The term "Freeway Series" also inspired the official name of the region's NHL rivalry: the Freeway Face-Off. Animosity between the team's fanbases grew stronger in 2005, when the Angels' new team owner Arte Moreno changed the name of his ball club from the 'Anaheim Angels', to the 'Los Angeles Angels of Anaheim'. Since the city of Anaheim is located roughly 30 miles from Downtown Los Angeles, the Angels franchise was ridiculed throughout the league for the contradictory nature surrounding the name, especially by Dodgers owner Frank McCourt, who filed a formal complaint to commissioner Bud Selig. Once the complaint was denied, McCourt devised a t-shirt mocking the crosstown rivals reading 'The Los Angeles Dodgers of Los Angeles', which remains popular amongst the fanbase to this day. Historical rivalry New York Yankees The Dodgers–Yankees rivalry is one of the most well-known rivalries in Major League Baseball. The two teams have met eleven times in the World Series, more times than any other pair from the American and National Leagues. The initial significance was embodied in the two teams' proximity in New York City, when the Dodgers initially played in Brooklyn. After the Dodgers moved to Los Angeles in 1958, the rivalry retained its significance as the two teams represented the dominant cities on each coast of the United States, and since the 1980s, the two largest cities in the United States. Although the rivalry's significance arose from the two teams' numerous World Series meetings, the Yankees and Dodgers have not met in the World Series since . They would not play each other in a non-exhibition game until 2004, when they played a three-game interleague series. Their last meeting was in August 2019, when the Yankees won two out of three games in Los Angeles. Fan support The Dodgers have a loyal fanbase, evidenced by the fact that the Dodgers were the first MLB team to attract more than 3 million fans in a season (in 1978), and accomplished that feat six more times before any other franchise did it once. The Dodgers drew at least 3 million fans for 15 consecutive seasons from 1996 to 2010, the longest such streak among all MLB teams. The team's largest fan club, Pantone 294 (a reference to the Pantone code of Dodger blue), regularly travel to away games to cheer for the Dodgers. On July 3, 2007, Dodgers management announced that total franchise attendance, dating back to 1901, had reached 175 million, a record for all professional sports. In 2007, the Dodgers set a franchise record for single-season attendance, attracting over 3.8 million fans. On March 28, 2008, the Dodgers set the world record for the largest attendance for a single baseball game during an exhibition game against the Boston Red Sox at the Los Angeles Memorial Coliseum in honor of the Dodgers' 50th anniversary, with 115,300 fans in attendance. In 2009, the Dodgers led the MLB in total attendance. The Dodger baseball cap is consistently in the top three in sales. Given the team's proximity to Hollywood, numerous celebrities can often be seen attending home games at Dodger Stadium. Celebrities such as co-owner Magic Johnson, Mary Hart, DaBaby, Larry King, Tiger Woods, Alyssa Milano, Shia LaBeouf, Lana Del Rey, Mila Kunis and Ashton Kutcher are known to frequently attend Dodger games, with some sitting at field box seats behind home plate where they sign autographs for fellow Dodger fans. Actor Bryan Cranston is a lifelong Dodger fan. Primarily, Dodgers fans are from their own location in southern California and also parts of southern Nevada. However, there are also numerous strong pockets of supporters in Mexico due to the impact of players such as Fernando Valenzuela or more recently; Julio Urias and the fanbase is ever present throughout Asian countries such as South Korea and Japan, and their away games throughout the US will usually attract substantial numbers of expats and traveling fans. Radio and television Vin Scully called Dodgers games from 1950 to 2016. His longtime partners were Jerry Doggett (1956–1987) and Ross Porter (1977–2004). In 1976, he was selected by Dodgers fans as the Most Memorable Personality (on the field or off) in the team's history. He is also a recipient of the Baseball Hall of Fame's Ford C. Frick Award for broadcasters (inducted in 1982). Unlike the modern style in which multiple sportscasters have an on-air conversation (usually with one functioning as play-by-play announcer and the other[s] as color commentator), Scully, Doggett and Porter generally called games solo, trading with each other inning-by-inning. In the 1980s and 1990s, Scully would call the entire radio broadcast except for the third and seventh inning, allowing the other Dodger commentators to broadcast an inning. When Doggett retired after the 1987 season, he was replaced by Hall-of-Fame Dodgers pitcher Don Drysdale, who previously broadcast games for the California Angels and Chicago White Sox. Drysdale died in his hotel room following a heart attack before a game in Montreal in 1993. This was a difficult broadcast for Scully and Porter who could not mention it on-air until Drysdale's family had been notified and the official announcement made. He was replaced by former Dodgers outfielder Rick Monday. Porter's tenure ended after the 2004 season, after which the format of play-by-play announcers and color commentators was installed, led by Monday and newcomer Charley Steiner. Scully, however, continued to announce solo. Scully called roughly 100 games per season (all home games and road games in California and Arizona) for both flagship radio station KLAC and on television for Spectrum SportsNet LA. Scully was simulcast for the first three innings of each of his appearances, then announced only for the TV audience. If Scully was calling the game, Steiner took over play-by-play on radio beginning with the fourth inning, with Monday as color commentator. If Scully was not calling the game, Steiner and Orel Hershiser called the entire game on television while Monday and Kevin Kennedy did the same on radio. In the event the Dodgers were in post-season play, Scully called the first three and last three innings of the radio broadcast alone and Steiner and Monday handled the middle innings. Vin Scully retired from calling games in 2016. His tenure with the Dodgers was the longest with any single sports team at 67 years. Youthful announcer Joe Davis was selected in 2017 by Dodgers management to handle play by play on television with Orel Hershiser as his colorman; when Davis is on assignment for Fox Sports' MLB and NFL broadcasts, Tim Neverett would fill in. The Dodgers also broadcast on radio in two other languages, Spanish and Korean. In Spanish, the play-by-play is voiced by another Frick Award winner, Jaime Jarrín, who has been with the Dodgers since 1959. The color analyst for some games is former Dodger pitcher Fernando Valenzuela, for whom Jarrin once translated post-game interviews. The Spanish-language radio flagship station is KTNQ. Meanwhile, the Dodgers' Korean broadcast began in 2013 through KMPC. Management Owner: Guggenheim Baseball Management Chairman/Controlling Partner: Mark Walter Partner: Earvin "Magic" Johnson Partner: Peter Guber Partner: Todd Boehly Partner: Billie Jean King Partner: Ilana Kloss Partner: Robert "Bobby" Patton, Jr. Partner: Alan Smolinisky Partner: Robert L. Plummer President/chief executive officer: Stan Kasten President of Baseball Operations: Andrew Friedman General Manager: Brandon Gomes Achievements Baseball Hall of Famers Ford C. Frick Award recipients Team captains Leo Durocher 1938–1941 Pee Wee Reese 1950–1958 Duke Snider 1962 Maury Wills 1963–1966 Davey Lopes 1978–1979 Retired numbers Koufax, Campanella, and Robinson were the first Dodgers to have their numbers retired, in a ceremony at Dodger Stadium on June 4, 1972. This was the year in which Koufax was inducted into the Baseball Hall of Fame; Robinson and Campanella were already Hall-of-Famers. Alston's number was retired in the year following his retirement as the Dodgers manager, six years before he was inducted into the Hall of Fame. Gilliam died suddenly in 1978 after a 28-year career with the Dodgers organization. The Dodgers retired his number two days after his death, prior to Game 1 of the 1978 World Series. As of 2018, he is the only non-Hall-of-Famer to have his number retired by the Dodgers (Alston's number was retired before he was elected to the Hall of Fame). Beginning in 1980, the Dodgers have retired the numbers of longtime Dodgers (Snider, Reese, Drysdale, Lasorda, and Sutton) during the seasons in which each was inducted into the Hall of Fame. In 1997, 50 years after he broke the color barrier and 25 years after the Dodgers retired his number, Robinson's No. 42 was retired throughout Major League Baseball. Robinson is the only major league baseball player to have this honor bestowed upon him. Starting in the 2007 season, Jackie Robinson Day (April 15, commemorating Opening Day of Robinson's rookie season of 1947) has featured many or all players and coaches wearing the number 42 as a tribute to Robinson. The Dodgers have not issued the number 34 since the departure of Fernando Valenzuela in 1991, although it has not been officially retired. In 2017, the Dodgers honored broadcaster Vin Scully with a microphone displayed alongside the team's retired numbers. In 2018 Spanish language broadcaster Jaime Jarrín was honored with a microphone displayed alongside the team's retired numbers. Awards Most Valuable Player (NL) Brooklyn – Jake Daubert 1924 – Dazzy Vance 1941 – Dolph Camilli 1949 – Jackie Robinson 1951 – Roy Campanella 1953 – Roy Campanella 1955 – Roy Campanella 1956 – Don Newcombe Los Angeles 1962 – Maury Wills 1963 – Sandy Koufax 1974 – Steve Garvey 1988 – Kirk Gibson 2014 – Clayton Kershaw 2019 – Cody Bellinger World Series MVP 1955 – Johnny Podres 1959 – Larry Sherry 1963 – Sandy Koufax 1965 – Sandy Koufax 1981 – Ron Cey, Pedro Guerrero and Steve Yeager 1988 – Orel Hershiser 2020 – Corey Seager Cy Young Award (NL) Brooklyn 1956 – Don Newcombe (MLB) Los Angeles 1962 – Don Drysdale (MLB) 1963 – Sandy Koufax (MLB) 1965 – Sandy Koufax (MLB) 1966 – Sandy Koufax (MLB) 1974 – Mike Marshall 1981 – Fernando Valenzuela 1988 – Orel Hershiser 2003 – Éric Gagné 2011 – Clayton Kershaw 2013 – Clayton Kershaw 2014 – Clayton Kershaw Triple Crown Brooklyn 1924 – Dazzy Vance Los Angeles 1963 – Sandy Koufax 1965 – Sandy Koufax 1966 – Sandy Koufax 2011 – Clayton Kershaw Rookie of the Year Award (NL) Brooklyn 1947 – Jackie Robinson (MLB) 1949 – Don Newcombe 1952 – Joe Black 1953 – Jim Gilliam Los Angeles 1960 – Frank Howard 1965 – Jim Lefebvre 1969 – Ted Sizemore 1979 – Rick Sutcliffe 1980 – Steve Howe 1981 – Fernando Valenzuela 1982 – Steve Sax 1992 – Eric Karros 1993 – Mike Piazza 1994 – Raúl Mondesi 1995 – Hideo Nomo 1996 – Todd Hollandsworth 2016 – Corey Seager 2017 – Cody Bellinger Team records Personnel Current roster Presidents Charlie Byrne (1883–1897) Charles Ebbets (1898–1925) Edward McKeever (1925, interim) Wilbert Robinson (1925–1929) Frank B. York (1930–1932) Stephen McKeever (1933–1938) Larry MacPhail (1939–1942) Branch Rickey (1943–1950) Walter O'Malley (1950–1970) Peter O'Malley (1970–1997) Bob Graziano (1998–2004) Jamie McCourt (2004–2009) Dennis Mannion (2009–2010) Stan Kasten (2012–present) Managers Since 1884, the Dodgers have used a total of 31 Managers, the most current being Dave Roberts, who was appointed following the 2015 postseason, after the departure of Don Mattingly. Over the nearly 43 years from 1954 to mid-1996, the Dodgers employed only two managers, Walter Alston and Tommy Lasorda, both of whom are in the Hall of Fame. During this entire time period of extraordinary stability, the Dodgers were family-owned by Walter O'Malley and then his son Peter O'Malley. It was during this era that the Dodgers won 11 of their 24 pennants, and their first six World Series championships. The managers of the Los Angeles Dodgers (1958–present) are as follows: Walter Alston (1958–1976) (in Brooklyn since 1954) Tommy Lasorda (1976–1996) Bill Russell (1996–1998) Glenn Hoffman (1998) Davey Johnson (1999–2000) Jim Tracy (2001–2005) Grady Little (2006–2007) Joe Torre (2008–2010) Don Mattingly (2011–2015) Dave Roberts (2016–present) General Managers Larry MacPhail (1938–1942) Branch Rickey (1943–1950) Buzzie Bavasi (1950–1968) Fresco Thompson (1968) Al Campanis (1968–1987) Fred Claire (1987–1998) Tommy Lasorda (1998) Kevin Malone (1999–2001) Dave Wallace (2001) Dan Evans (2001–2004) Paul DePodesta (2004–2005) Ned Colletti (2005–2014) Farhan Zaidi (2014–2018) Vacant (2019–present) Public address announcers/organists From the Dodgers' move to Los Angeles from Brooklyn in 1958, the Dodgers employed a handful of well-known public address announcers; the most famous of which was John Ramsey, who served as the PA voice of the Dodgers from 1958 until his retirement in 1982; he was also well known for announcing at other venerable Los Angeles venues, including the Los Angeles Memorial Coliseum and Sports Arena, and the Forum. Ramsey died in 1990. From 1958 to 1982, Doug Moore, Philip Petty, and Dennis Packer served as back-up voices for John Ramsey for the Dodgers, California Angels, Los Angeles Chargers, USC football and Los Angeles Rams. Packer was Ramsey's primary backup for the Los Angeles Lakers and Los Angeles Kings until Ramsey's retirement from the Forum in 1978. Thereafter, Packer became the public address announcer for the Lakers, Kings, indoor soccer and indoor tennis events at the Forum. Nick Nickson, a radio broadcaster for the Los Angeles Kings, replaced John Ramsey as the Dodger Stadium public address announcer in 1983 and served in that capacity through the 1989 season to work with the Kings full-time. Dennis Packer and Pete Arbogast were emulators of John Ramsey, using the same stentorian style of announcing Ramsey was famous for. Packer and Arbogast shared the stadium announcing chores for the 1994 FIFA World Cup matches at the Rose Bowl. Arbogast won the Dodgers job on the day that Ramsey died on January 25, 1990, by doing a verbatim imitation of Ramsey's opening and closing remarks that were standard at each game. His replacement, in 1994 was Mike Carlucci, who remained as the Dodgers' PA voice announcer until he resigned in 2002 to concentrate on his voiceover and acting career along with his Olympics announcing duties. From 2003 to 2014, the Dodgers public address announcer was Eric Smith, who also announces for the Los Angeles Clippers and USC Trojans. On April 3, 2015, the Dodgers announced that former radio broadcaster Todd Leitz was hired to become their new public address announcer. Leitz was an anchor and news reporter in Los Angeles at KNX 1070 AM for 10 years, and a news reporter at KABC 790 for two years. From 1988 to 2015, Nancy Bea enjoyed popularity behind the Dodger Stadium keyboard similar to Gladys Goodding. Since retirement in 2015, Bea's replacement and current organist is Dieter Ruehle, who also plays at Staples Center for Los Angeles Kings games. Other Vin Scully is permanently honored in the Baseball Hall of Fame's "Scribes & Mikemen" exhibit as a result of winning the Ford C. Frick Award in 1982. Frick Award recipients are not official members of the Hall. Sue Falsone, was the first female physical therapist in Major League baseball, and from 2012 to 2013, was the first female head athletic trainer. Minor league affiliations The Los Angeles Dodgers farm system consists of seven minor league affiliates. See also 1994 in baseball Dodger Dog List of Los Angeles Dodgers broadcasters List of Los Angeles Dodgers managers List of Los Angeles Dodgers seasons Los Angeles Dodgers all-time roster Los Angeles Dodgers minor league players Roy Campanella Award Notelist References Further reading Red Barber, Rhubarb in the Catbird Seat Stanley Cohen, Dodgers! The First 100 Years Robert W. Creamer, Stengel: His Life and Times Steve Delsohn, True Blue: The Dramatic History of the Los Angeles Dodgers, Told By the Men Who Lived It Carl Erskine and Vin Scully, Tales From the Dodger Dugout: Extra Innings Harvey Froemmer, New York City Baseball Steve Garvey, "My Bat Boy Days: Lessons I Learned from the Boys of Summer" Cliff Gewecke, Day by Day in Dodgers History Andrew Goldblatt, The Giants and the Dodgers: Four Cities, Two Teams, One Rivalry Richard Goldstein, Superstars and Screwballs: 100 Years of Brooklyn Baseball Peter Golenbock, Bums: An Oral History of the Brooklyn Dodgers Doris Kearns Goodwin, Wait Till Next Year: A Memoir Frank Graham, The Brooklyn Dodgers: An Informal History Orel Hershiser with Jerry B. Jenkins, Out of the Blue Donald Honig, The Los Angeles Dodgers: Their First quarter Century Roger Kahn, The Boys of Summer Roger Kahn, The Era 1947–1957: When the Yankees, the Giants and the Dodgers Ruled the World Mark Langill, The Los Angeles Dodgers Tommy Lasorda with David Fisher, The Artful Dodger Jane Leavy, Sandy Koufax: A Lefty's Legacy Joseph McCauley, Ebbets Field: Brooklyn's Baseball Shrine William McNeil, The Dodgers Encyclopedia Tom Meany (editor), The Artful Dodgers Andrew Paul Mele, A Brooklyn Dodgers Reader John J. Monteleone (editor), Branch Rickey's Little Blue Book Thomas Oliphant, Praying for Gil Hodges: A Memoir of the 1955 World Series and One Family's Love of the Brooklyn Dodgers David Plaut, Chasing October: The Dodgers-Giants Pennant Race of 1962 Carl E. Prince, Brooklyn's Dodgers: The Bums, The Borough and The Best of Baseball Jackie Robinson, I Never Had It Made Gene Schoor, The Complete Dodgers Record Book Gene Schoor, The Pee Wee Reese Story Duke Snider with Bill Gilbert, The Duke of Flatbush Michael Shapiro, The Last Good Season: Brooklyn, The Dodgers, and Their Final Pennant Race Together Glen Stout, The Dodgers: 120 Years of Dodgers Baseball Neil J. Sullivan, The Dodgers Move West Jules Tygiel, Baseball's Great Experiment: Jackie Robinson and His Legacy John Weaver, Los Angeles: The Enormous Village, 1781–1981 External links Los Angeles Dodgers Baseball Reference.com "The 1960s Dodgers: Two Parts Patience, One Part Creative Insanity" by Steve Treder, November 10, 2004. Article on the 1960s Los Angeles Dodgers in The Hardball Times. Dodgers Major League Baseball teams Cactus League Baseball teams established in 1883 1883 establishments in New York (state) Baseball teams established in 1958 1958 establishments in California Companies that filed for Chapter 11 bankruptcy in 2011 Shorty Award winners	[ 0.19947294890880585, 0.12693430483341217, -0.4319192171096802, 0.07371871918439865, -0.10814744979143143, -0.16690181195735931, -0.04572880640625954, 0.44517752528190613, -0.6455578207969666, -0.33525753021240234, 0.2467033565044403, 0.37254956364631653, -0.2096615731716156, 0.187297716736...
18214	https://en.wikipedia.org/wiki/Louis%20Andriessen	Louis Andriessen	Louis Joseph Andriessen (; 6 June 1939 – 1 July 2021) was a Dutch composer, pianist and academic teacher. Considered the most influential Dutch composer of his generation, he was a central proponent of The Hague school of composition. Although his music was initially dominated by neoclassicism and serialism, his style gradually shifted to a synthesis of American minimalism, jazz and the manner of Stravinsky. Born in Utrecht into a musical family, Andriessen studied with his father, the composer Hendrik Andriessen as well as composers Kees van Baaren and Luciano Berio. Andriessen taught at the Royal Conservatory of The Hague from 1974 to 2012, influencing notable composers. His opera La Commedia, based on Dante's Divine Comedy, won the 2011 Grawemeyer Award for Music Composition and was selected in 2019 by critics at The Guardian as one of the most outstanding compositions of the 21st century. Life and career Andriessen was born in Utrecht on 6 June 1939 to a musical family, the son of the composer Hendrik Andriessen and Johanna Justina Anschütz (1898–1975). His father was professor of composition at the Royal Conservatory of The Hague, and later its director. His siblings are composers Jurriaan Andriessen and Caecilia Andriessen (1931–2019), and he is the nephew of Willem Andriessen (1887–1964). Andriessen originally studied with his father and Kees van Baaren at the Royal Conservatory of The Hague, graduating in 1961 with a first prize, before embarking upon two years of study with Italian composer Luciano Berio in Milan and Berlin. His father introduced him to the works of Francis Poulenc and Eric Satie which he came to love. From 1961-65, Andriessen wrote for the daily De Volkskrant, and for De Gids magazine from 1966-69. Andriessen lived in Amsterdam since 1965. In 1969, he was part of a group of protesters at a concert of the Concertgebouw Orchestra. They disrupted the concert with nutcrackers and bicycle horns, handing out leaflets on the dismal representation of Dutch new music in the orchestra's programming. The next year, he and the other "Nutcrackers" were given one-week prison sentences, and yet their protest sparked something of a social reform in the Dutch music scene. Andriessen was internationally recognised as a composer with his 1976 De Staat which included texts from Plato's Republic. He was one of the founders of the Hague School, an avant-garde and minimalist movement from the second half of the 20th century. In later decades, he accepted commissions from major orchestras, including the San Francisco Symphony, the Los Angeles Philharmonic, the BBC Symphony Orchestra and the New York Philharmonic. Andriessen was the focus of festivals in Tanglewood (1994), London (1994; 2002), Tokyo (2000), Brisbane (2001) and New York (2004). In 2008, he was elected an honorary member of the International Society for Contemporary Music ISCM. He held the Richard and Barbara Debs Composer's Chair at Carnegie Hall during the 2009–10 season. Ensembles In 1969, Andriessen co-founded Studio voor Elektro-Instrumentale Muziek STEIM in Amsterdam. In opposition to the classical orchestra, a structure seen as "hierarchical", he also helped founding the instrumental groups Orkest de Volharding and Hoketus, both of which performed compositions of the same names, formed by classical, jazz and pop musicians. He later became closely involved with the Schonberg and Asko ensembles and inspired the formation of the British ensemble Icebreaker. Teaching Andriessen joined the faculty of the Royal Conservatory in 1974. He taught instrumentation from 1974 to 1978 and taught composition there from 1978 to 2012, where he influenced notable students including Michel van der Aa, Richard Ayres and Steve Martland. Yale University invited him in 1987 to lecture on theory and composition, he was also guest lecturer at New York State University, Buffalo (1989) and Princeton (1996). The arts faculty of the University of Leiden appointed him professor in 2004. Personal life Andriessen was married to guitarist Jeanette Yanikian (1935–2008). They were a couple for over 40 years, and were married in 1996. La Commedia is dedicated to Yanikian. He was married in 2012 a second time to violinist Monica Germino, for whom he wrote several works. In December 2020, she announced that the composer was suffering from dementia. He died on 1 July 2021 in Weesp at age 82. Style and notable works Andriessen began in the style of an intentionally dry neoclassicism, but then turned into a strict serialist. His early works show experimentation with various contemporary trends: post-war serialism (Series, 1958), pastiche (Anachronie I, 1966–67), and tape (Il Duce, 1973). His reaction to what he perceived as the conservatism of much of the Dutch contemporary music scene quickly moved him to form a radically alternative musical aesthetic of his own. From the early 1970s on he refused to write for conventional symphony orchestras and instead opted to write for his own idiosyncratic instrumental combinations, which often retain some traditional orchestral instruments alongside electric guitars, electric basses, and congas. Andriessen repeatedly used his music for political confessions and messages, but he also referred to painting and philosophy. His range of inspiration was wide, from the music of Charles Ives in Anachronie I, the art of Mondriaan in De Stijl, and medieval poetic visions in Hadewijch, to writings on shipbuilding and atomic theory in De Materie Part I. Andriessen's later style is a unique blend of American sounds and European forms. His mature music combines the influences of jazz, American minimalism, Igor Stravinsky, and Claude Vivier. The music consists of minimalist polyrhythms, lyrical melodic fragments, predominantly consonant harmonies disrupted by explosive blocks of concentrated dissonance. Andriessen's music thus departs from post-war European serialism and its offshoots. By the 21st century he was widely regarded as Europe's most important minimalist composer. His notable works include Workers Union (1975), a melodically indeterminate piece "for any loud sounding group of instruments" whose score specifies rhythm and contour but not exact pitch; Mausoleum (1979) for two baritones and large ensemble; De Tijd (Time, 1979–81) for female singers and ensemble; De Snelheid (Velocity, 1982–83), for three amplified ensembles; De Materie (Matter, 1984–88), a large four-part work for voices and ensemble; collaborations with filmmaker and librettist Peter Greenaway on the film M is for Man, Music, Mozart and the operas Rosa: A Horse Drama (1994) and Writing to Vermeer (1998); and La Passione (2000–02) for female voice, violin and ensemble. His opera La Commedia, based on Dante's Divine Comedy, is particularly renowned; it won the 2011 Grawemeyer Award for Music Composition and was selected in 2019 by critics at The Guardian as No 7 of the then most outstanding compositions of the 21st century. Awards and honours 1959 Gaudeamus International Composers Award 1977 Matthijs Vermeulen Award for De Staat 1977 UNESCO International Rostrum of Composers in Paris 1992 Matthijs Vermeulen Award for M. is for Man, Music and Mozart; Facing Death, Dances, Hout en Lacrimosa 1993 Edison Award 2010 Honorary doctorate from the Birmingham City University 2011 Grawemeyer Award for Music Composition for the multimedia opera La Commedia (2004–2008). 2016 Marie-Josée Kravis Prize for New Music 2019 Honorary doctorate from the University of Amsterdam Works Andriessen's primary publishers are Boosey & Hawkes and Donemus. Complete list of works: Rondo Barbaro (1954) for piano Sonata (1956) for flute and piano (dedicated to Lucas van Regteren Altena) Elegy (1957) for cello and piano Elegy (1957) for double bass and piano (arrangement by Quirijn van Regteren Altena) Nuit d'été (1957) for piano four hands Quartet in two movements (1957) for string quartet Séries (1958) for 2 pianos Nocturnen (1959) (text by the composer) for 2 sopranos, orchestra (dedicated to Jeanette Yanikian) Percosse (1959) for flute, trumpet, bassoon and percussion Prospettive e Retrospettive (1959) for piano Trois Pièces (1961) for piano left hand Aanloop en sprongen (1961) (Rincorsa e salti) for flute, oboe and clarinet in Bb Ittrospezione I (1961) for piano 4 hands Joli commentaire (1961) for piano 4 hands Paintings (1961) for one flutist (or recorder player) and one pianist Étude pour les timbres (1962) for piano Triplum (1962) for guitar (dedicated to Jeanette Yanikian) Canzone 3 (Utinam) (1962) for voice and piano Constructions for a Ballet (1962, revision 2009) for orchestra, including Ondine, timbres voor orkest Plein-chant (1963) for flute and harp (dedicated to Eugenie van des Grinten and Veronica Reyns) Ittrospezione II (1963) for large orchestra Sweet (1964) for alto (treble) recorder (dedicated to Frans Brüggen) Registers (1963) for piano A flower song II (1964) for oboe solo A flower song III (1964) for violoncello solo Ittrospezione III (Concept I) (1964) for 2 pianos and 3 instrumental groups Double (1965) for clarinet and piano (dedicated to George Pieterson and Tan Crone) Ittrospezione III (Concept II) – Fragment (1965) tenor saxophone ad libitum, 2 pianos (section of Ittrospezione III [Concept II]; may be performed separately) Beatles Songs (1966) (satirical arrangements of four Beatles songs) for female voice and piano Souvenirs d'enfance (1954–1966) for piano. Including amongst others: Nocturne, Ricercare, Allegro Marcato, As you like it, Blokken, Strawinsky, Rondo opus 1, Étude pour les timbres, dotted quarter note = 70 Rage, rage against the dying of the light (1966) for 4 trombones Anachronie I (1966–67) for large orchestra The Garden of Ryoan-gi (1967) for 3 electronic organs Worum es ging und worum es geht (1967) (with Misha Mengelberg) for orchestra Contra tempus (1967–1968) for large ensemble Choralvorspiele (1969) for barrel organ Anachronie II (1969) for oboe, small orchestra (4 horns, harp, piano, strings) Hoe het is (1969) for 52 strings and live electronics Sonate op. 2 nr. 1 (1969) for piano with interruptions from string quartet (based on Piano Sonata No. 1 by Ludwig van Beethoven) (1969) (with Reinbert de Leeuw, Misha Mengelberg, Peter Schat, Jan van Vlijmen; libretto by Hugo Claus, Harry Mulisch) Morality opera for soloists, 3 mixed choruses (4 voices each), orchestra (11 winds, 7 brass, 2 guitars, 11 keyboards, 10 strings), live electronics De negen symfonieën van Beethoven (1970) for ice cream bell, orchestra Spektakel (1970) for improvisational ensemble (saxophone [+ bass clarinet], viola, bass guitar, electronic organ [+ piano], percussion [or other instruments]), small orchestra (12 winds, 4 horns, 6 percussion) Vergeet mij niet (1970) (Forget me not) for oboe Le voile du bonheur (1966–1971) for violin and piano een, twee (1971) for organ, 10 instrumentalists and piano In Memoriam (1971) for tape Volkslied (1971) for an unlimited number and kinds of instruments (in all octaves) (based on the Dutch national anthem Wilhelmus van Nassouwe and on The Internationale) De Volharding (1972) (Perseverance) for piano and wind instruments (written for Orkest de Volharding) Dat gebeurt in Vietnam (1972) (That's going on in Vietnam) for wind ensemble Arrangement of Solidaritätslied by Hanns Eisler (1972) for wind ensemble Arrangement of Streikslied by Hanns Eisler (1972) for wind ensemble Arrangement of In C by Terry Riley (1972) for wind ensemble Arrangement of Bereits sprach der Welt by Hanns Eisler (1972) for wind ensemble Arrangement of Tango by Igor Stravinsky (1972) for wind ensemble Arrangement of La création du monde by Darius Milhaud (1972) for wind ensemble Thanh Hoa (1972) (text by Nguyen Thai Mao) for voice and piano Canzone 3: Utinam (1972) (text from the Book of Job) for soprano, piano, 1962; Thanh Hoa (text by Nguyen Thay Mao), voice, piano On Jimmy Yancey (1973) for 9 winds, piano and double bass (written for Orkest de Volharding) Voor Sater (1973) for wind ensemble Amsterdam Vrij (1973) for wind ensemble Il Duce (1973) for tape The family (1973) for ensemble (film music) Melodie (1972–1974) for alto recorder (or other flute) and piano Arrangement of Ipanema and Gavea from Saudades do Brasil by Darius Milhaud (1974) for wind ensemble Il Principe (1974) (text by Niccolò Machiavelli) for 2 mixed choruses, 8 winds, 3 horns, tuba, bass guitar, piano Wals (1974) for piano Symfonieën der Nederlanden (1974) for 2 or more symphonic bands (minimum 32 players) Nederland, let op uw schoonheyt (1975) for symphonic band Workers Union (1975) for any loud-sounding group of instruments De Staat (1972–76) (text by Plato) for 2 sopranos, 2 mezzo-sopranos, 4 oboes (3rd, 4th + English horn), 4 horns, 4 trumpets, 3 trombones, bass trombone, 2 harps, 2 electric guitars, 4 violas, bass guitar, 2 pianos (also transcribed for two pianos in 1992 by Cees van Zeeland and Gerard Bouwhuis) Mattheus passie (1976) (text by Louis Ferron) Music theatre work for 8 mixed voices, 2 oboes (both + English horn), Hammond organ, string quartet, double bass Hoketus (1975–76) for 2 panpipes, 2 alto saxophones ad libitum, 2 bass guitars, 2 pianos, 2 electric pianos, 2 congas Orpheus (1977) (text by Lodewijk de Boer) Music theatre work for 8 mixed voices, lyricon, electric guitar, bass guitar, synthesizer, percussion Symphonie voor losse snaren (1978) for 12 strings Laat toch vrij die straat (1978) (text by Jaap van der Merwe) for voice and piano Hymn to the Memory of Darius Milhaud (1978) (version of chamber work) Felicitatie (1979) for 3 trumpets Toespraak (1979) for speaker who also plays trombone Mausoleum (1979 rev. 1981) (texts by Mikhail Bakunin, Arthur Arnould) for 2 high baritones, orchestra (12 brass, 2 harps, cimbalom, 2 pianos, 2 percussion, minimum 10 strings, bass guitar) Music for the film The Alien (1980) (Rudolf van den Berg) George Sand (1980) (text by Mia Meyer) Music theatre work for 8 mixed voices, 4 pianos Un beau baiser (1980) for mixed chorus Messe des pauvres by Erik Satie, arrangement by Louis Andriessen for choir, 15 solo strings, accordion, contrabass clarinet and harp (1980) Ende (1981) for 2 alto recorders (1 player) (dedicated to Frans Brüggen) Anfang (1981) for sopranino recorder and piano De Tijd (1979–81) (text by St. Augustine of Hippo) for female chorus, percussion ensemble, orchestra (6 flutes, 2 alto flutes, 3 clarinets, contrabass clarinet, 6 trumpets, 2 harps, 2 pianos, Hammond organ, strings, 2 bass guitars) Commentaar (1981) (text by Wilhelm Schön) for voice and piano La voce (1981) (to a text by Cesare Pavese) for cello and voice Disco (1982) for violin and piano Overture to Orpheus (1982) for harpsichord De Snelheid (1982–83 rev. 1984) for 3 amplified ensembles Y después (1983) (text by Federico García Lorca) for voice and piano Menuet voor Marianne (1983) for piano Trepidus (1983) for piano Doctor Nero (1984) Music theatre work Berceuse voor Annie van Os (1985) for piano De Lijn (1986) for 3 flutes Dubbelspoor (1986 rev. 1994) Ballet music for piano, harpsichord, celesta, glockenspiel De Materie (1984–88) (texts from the Plakkaat van Verlatinge, Nicolaes Witsen, David Gorlaeus, Hadewijch, M.H.J. Schoenmaekers, Madame van Domselaer-Middelkoop, Willem Kloos, Marie Curie, Françoise Giroud). Music theatre work for soprano, tenor, 2 female speakers, 8 amplified mixed voices, amplified orchestra (15 winds, 13 brass, harp, 2 electric guitars, 2 pianos [one + electric piano], off-stage upright piano, celesta, 2 synthesizers, 6 percussion, minimum 9 strings, bass guitar. Two of its four sections may be performed separately as concert works: [2] Hadewijch, [3] De Stijl De Toren (1988, rev. 2000) for carillon Nietzsche redet (1989) (text by Friedrich Nietzsche) for speaker, alto flute, English horn, clarinet, bass clarinet, bassoon, 2 violins, viola, 2 celli, double bass, 2 pianos Flora Tristan (1990) for mixed choir a cappella (text by Fleur Bourgonje) Facing Death (1990) for amplified string quartet Facing Death (1990) for saxophone quartet (arrangement by Aurelia Saxophone Quartet) Dances (1991) (text by Joan Grant, choreography by Bianca van Dillen) For soprano, small orchestra (amplified harp, amplified piano, percussion, strings). May be performed as a concert work. M is for Man, Music, Mozart (1991) (texts by the composer, Jeroen van der Linden, Peter Greenaway) for female jazz voice, flute (+ piccolo), soprano saxophone, alto saxophone, tenor saxophone, horn, 3 trumpets, 2 trombones, bass trombone, double bass, piano (TV score; may be performed as a concert work with one additional song) Lacrimosa (1991) for 2 bassoons Lacrimosa (1991) for 2 flutes (arrangement by Manuel Zurria) Hout (1991) for tenor saxophone, electric guitar, piano and marimba (+ woodblocks) Romance voor Caecilia (1991) for piano Nadir en Zenit (1992) improvisations on poems by Sybren Polet for voice and piano (+ synthesizer) ...not being sundered (1992) (text by Rainer Maria Rilke) for soprano, flute, cello Song Lines (1992) for 3–6 saxophones Deuxième chorale (1992) for music box The Memory of Roses (1992) for piano (+ toy piano) Chorale (1992) for piano M is Muziek, Monoloog en Moord (1993) (text by Lodewijk de Boer) Music theatre work Lied (1993) for piano Rosa – A Horse Drama: The Death of a Composer (1993–94) (libretto by Peter Greenaway) Opera for 2 sopranos, tenor, 2 baritones, female speaker, 8 mixed voices, orchestra. Een lied van de zee (1994) (text by Hélène Swarth) for female voice Zilver (1994) for flute, clarinet, violin, cello, piano, vibraphone and marimba Base (1994) for piano left hand Odysseus' Women (1995) (text by Homer, choreography by Beppie Blankert) for 2 sopranos, 2 altos, sampler De komst van Willibrord (1995) for carillon To Pauline O (1995) for oboe Machmes Wos (1996) for voice, piano Trilogie van de Laatste Dag (1996–97) (each of its three sections may be performed separately: (i) The Last Day (texts by Lucebert, folksong A Woman and Her Lass) for boy soprano, 4 male voices, orchestra; (ii) TAO (texts by Laozi, Kotaro Takamura) for 4 female voices, piano [+ voice, koto], small orchestra [5 winds, 2 horns, harp, piano (+ celesta), 2 percussion, minimum 14 strings]; (iii) Dancing on the Bones (text by the composer) for children's chorus, orchestra, 1997) De herauten (1997) for 3 horns, 3 trumpets, 3 trombones, tuba, timpani Not an Anfang (1997) for piano De eerste minnaar (1998) (text by Toon Tellegen) for boy soprano, organ, 1998 (section of music theatre work Oldenbarneveldt; may be performed as a concert work) Tuin van Zink (1998) for viola and live electronics Writing to Vermeer (1997–99) (libretto by Peter Greenaway) Opera for 2 children's voices, 2 sopranos, mezzo-soprano, female chorus, orchestra (7 winds, 2 horns, 2 trumpets [2nd + bass trumpet], 2 harps, 2 electric guitars, cimbalom, 2 pianos, on-stage harpsichord, 2 percussion, minimum 22 strings), CD (music by Michel van der Aa) Woodpecker (1999) for percussion Image de Moreau (1999) for piano Dirck Sweelinck Missed the Prince (1999) for harpsichord Passeggiata in tram in America e ritorno (1999) (text by Dino Campana) for female Italian voice, violin and piano What Shall I Buy You, Son? (2000) for voice, piano Boodschappenlijstje van een gifmengster (2000) (text by the composer) for vocalist (also writes), voice (may be performed as Shopping List of a Poisoner [translated by Nicoline Gatehouse] Inanna's Descent (2000) for mezzo-soprano, piccolo, oboe, violin, piano, 2 percussion ensembles (4–12 total players) The New Math(s) (2000) (text by Hal Hartley) for soprano, transverse flute, violin, marimba, CD (music by Michel van der Aa), 2000 (film score; may be performed as a concert work) Feli-citazione (2000) for piano Passeggiata in tram in America e ritorno (2001) (text by Dino Campana) for female Italian voice, 3 trumpets, 3 trombones, electric guitar, electric violin, double bass, piano, percussion, 1998 (also version for voice, flute, horn, 3 trumpets, 3 trombones, amplified violin, double bass, piano De vleugels van de herinnering (2001) (text by Larissa Tiginachvili [Dutch translation]) for voice, piano Fanfare om te beginnen (2001) for 6 groups of horns La Passione (2000–02) (text by Dino Campana) for female jazz voice, violin, small orchestra (7 winds, 7 brass, electric guitar, cimbalom, 2 pianos, synthesizer, 2 percussion, 3 violins, bass guitar) Very Sharp Trumpet Sonata (2002) for trumpet Tuin van Eros (Garden of Eros) (2002) for string quartet Klokken voor Haarlem (Bells for Haarlem) (2002) for piano, celesta, synthesizer, vibraphone (+ glockenspiel) Pupazzetti by Alfredo Casella, arranged by Louis Andriessen for ensemble in 2002–2003 Inanna (2003) texts by Hal Hartley, Theo J.H. Krispijn) for 4 voices, 3 actors, mixed chorus, contrabass clarinet, 4 saxophones, violin, film (by Hal Hartley) Letter from Cathy (2003) (text from a letter by Cathy Berberian to the composer) for female jazz voice, harp, violin, double bass, piano, percussion Tuin van Eros (2003) for violin and piano RUTTMANN Opus II, III, IV (2003) for flute, 3 saxophones, horn, 3 trumpets, 3 trombones, double bass, piano (film music for a film of Walter Ruttman, written for the Filmmuseum Biennale 2003) Haags Hakkûh (The Hague Hacking) (2003) for 2 pianos. Renamed to Haags Hakkûh Stukje (The Hague Hacking Scrap) in 2008. Racconto dall'inferno (2004) (text by Dante Alighieri) for female jazz voice, small orchestra (8 winds, 6 brass, guitar, cimbalom, 2 pianos, 2 percussion, minimum 8 strings, bass guitar). Part II of La Commedia (2004–08). De Opening (2005) for ensemble (combined Orkest de Volharding, ASKO Ensemble, Schoenberg Ensemble) Vermeer Pictures (2005) concert suite for orchestra from Writing to Vermeer (arrangement by Clark Rundell) XENIA (2005) for violin Hymn to the memory of Darius Milhaud for ensemble (1974/2006) Hellende Fanfare (Inclined fanfare; Fanfara inclinata) (2006) for voice and ensemble (Text by Dino Campana) Raadsels (Riddle) (2006) for solo violin Johann Sebastian Bach's Prelude in b minor from the Well-Tempered Clavier BWV 866, arranged for string quartet with the first six bars augmented with a viola part by Igor Stravinsky, completed by Louis Andriessen (2006) ..miserere... (2006–07) for string quartet The City of Dis or: The Ship of Fools (2007) for voices and ensemble. Part I of La Commedia (2004–08). La Commedia (2004–08). Film opera in five parts (texts by Dante and Vondel and from the Old Testament) Haags Hakkûh (The Hague Hacking) (2008) for two pianos and large ensemble Christiaan Andriessens uitzicht op de Amstel (Christiaan Andriessen's view on the river Amstel) (2009) for ensemble Life (2009) for ensemble, with film by Marijke van Warmerdam Anaïs Nin (2009/10) for singer, ensemble and film La Girò (2011), for violin solo and ensemble Mysteriën (2013), for orchestra Tapdance (2013), concerto for percussion and large ensemble Two way ticket (2014), for piano Theatre of the World (2013–15), a 'grotesque stagework' in nine scenes (Libretto by Helmut Krausser) Mach's mit mir, Gott (Do unto me, God) (2016), for organ Signs and Symbols (2016), for wind ensemble and percussion Ahania Weeping (2016), for mixed chorus De goddelijke routine (The divine routine) (2017), for organ Rimsky or La Monte Young (2017), for piano Agamemnon (2017), for speaker and large orchestra Searching for unison (étude) (2018), for piano The Only One (2018), song cycle for female jazz singer and large ensemble, dedicated to Nora Fischer, who premiered the work at The Proms 2019 May (2019), for choir and orchestra References Sources Further reading Adlington, Robert: De Staat. Hants. (UK): Ashgate (2004). Andriessen, Louis and Elmer Schonberger (trans. Jeff Hamburg): The Apollonian Clockwork: On Stravinsky Amsterdam: Amsterdam UP (reprint, 2006). Everett, Yayoi Uno. The Music of Louis Andriessen. Cambridge: Cambridge University Press (2006). . Zegers, Mirjam (ed.): Trans. Clare Yates. The Art of Stealing Time. Arc Publications. . External links Louis Andriessen / 1939 – 2021 ( biography, works list, recordings and performance search) Boosey and Hawkes 2021 Andriessen on Andriessen (documentary) Louis Andriessen Nonesuch Records Robert Davidson: Louis Andriessen interview topologymusic.com 2001 1939 births 2021 deaths 20th-century classical composers 20th-century Dutch composers 20th-century Dutch male musicians 21st-century classical composers 21st-century Dutch composers 21st-century male musicians Composers for carillon Contemporary classical music performers Dutch anarchists Dutch classical composers Dutch classical pianists Dutch male classical composers Gaudeamus Composition Competition prize-winners International Rostrum of Composers prize-winners Male classical pianists Minimalist composers Nonesuch Records artists Musicians from Utrecht (city) Postmodern composers Pupils of Luciano Berio Royal Conservatory of The Hague alumni Royal Conservatory of The Hague faculty Twelve-tone and serial composers	[ -0.24049322307109833, 0.5236119031906128, 0.02589081972837448, -0.6402840614318848, -0.11889932304620743, 1.0548195838928223, 0.27772316336631775, -0.2458311766386032, -0.13643237948417664, -0.4205370247364044, 0.08564657717943192, -0.058691881597042084, 0.07101104408502579, 0.151148542761...
18217	https://en.wikipedia.org/wiki/Leonard%20Peltier	Leonard Peltier	Leonard Peltier (born September 12, 1944) is an American Indian activist and mainstay member of the American Indian Movement who, following a controversial trial, was convicted of aiding and abetting murder and has been imprisoned since 1977. He was sentenced to two consecutive terms of life imprisonment for aiding and abetting resulting in the death of two Federal Bureau of Investigation (FBI) agents in a June 26, 1975 shooting on the Pine Ridge Indian Reservation in South Dakota. In his 1999 memoir Prison Writings: My Life Is My Sun Dance, Peltier admitted to participating in the shootout but said he did not kill the FBI agents. Human rights watchdogs, such as Amnesty International, and political figures including Nelson Mandela, Mother Teresa, and the 14th Dalai Lama, have campaigned for clemency for Peltier in recent decades. At the time of the shootout, Peltier was an active member of the American Indian Movement (AIM), an indigenous rights advocacy group that worked to combat the racism and police brutality experienced by American Indians. Peltier ran for President of the United States in 2004, winning the nomination of the Peace and Freedom Party, and receiving 27,607 votes, limited to the ballot in California. He ran as Vice President of the United States in 2020, on a ticket with Gloria LaRiva as the presidential candidate, on tickets for other left parties as well as on the ballot of the Peace and Freedom Party. Leonard withdrew from those tickets on August 1, 2020 for health reasons. Peltier is incarcerated at the United States Penitentiary, Coleman in Florida. Peltier became eligible for parole in 1993. On January 18, 2017, it was announced that President Barack Obama denied Peltier's application for clemency. He is of Lakota, Dakota and French descent. He is an enrolled member of the Turtle Mountain Chippewa. Early life and education Peltier was born on September 12, 1944, at the Turtle Mountain Indian Reservation of the Turtle Mountain Chippewa near Belcourt, North Dakota, in a family of 13 children. Peltier's parents divorced when he was four years old. Leonard and his sister Betty Ann lived with their paternal grandparents Alex and Mary Dubois-Peltier in the Turtle Mountain Indian Reservation. In September 1953, at the age of nine, Leonard was enrolled at the Wahpeton Indian School in Wahpeton, North Dakota, an Indian boarding school run by the Bureau of Indian Affairs (BIA). Leonard remained away from his home at Wahpeton Indian School through the ninth grade; the school forced assimilation to white American culture by requiring the children to use English and forbidding the inclusion of Native American culture. He graduated from Wahpeton in May 1957, and attended the Flandreau Indian School in Flandreau, South Dakota. After finishing the ninth grade, he returned to the Turtle Mountain Reservation to live with his father. Peltier later obtained a general equivalency degree (GED). Career and activism In 1965, Peltier relocated to Seattle, Washington. Peltier worked as a welder, a construction worker, and as the co-owner of an auto shop in Seattle in his twenties. The co-owners used the upper level of the building as a kind of stopping place, or halfway house, for American Indians who had alcohol addiction issues or had recently finished their prison sentences and were re-entering society. However, the halfway house took a financial toll on the shop, so they closed it down. In Seattle, Peltier became involved in a variety of causes championing Native American civil rights. In the early 1970s, he learned about the factional tensions at the Pine Ridge Indian Reservation in South Dakota between supporters of Richard Wilson, elected tribal chairman in 1972, and traditionalist members of the Lakota tribe. It was Dennis Banks who first invited Leonard Peltier to join AIM. Consequently, Peltier became an official member of the American Indian Movement (AIM) in 1972, which was founded by urban Indians in Minneapolis in 1968, at a time of rising Indian activism for civil rights. Wilson had created a private militia, known as the Guardians of the Oglala Nation (GOON), whose members were reputed to have attacked political opponents. Protests over a failed impeachment hearing of Wilson contributed to the AIM and Lakota armed takeover of Wounded Knee at the reservation in February 1973. Federal forces reacted, conducting a 71-day siege, which became known as the Wounded Knee incident. They demanded the resignation of Wilson. Peltier, however, spent most of the occupation in a Milwaukee, Wisconsin jail charged with attempted murder related to a different protest. When Peltier secured bail at the end of April, he took part in an AIM protest outside the federal building in Milwaukee and was on his way to Wounded Knee with the group to deliver supplies when the incident ended. In 1975, Peltier traveled as a member of AIM to the Pine Ridge Indian Reservation to try to help reduce the continuing violence among political opponents. At the time, he was a fugitive, with an arrest warrant having been issued in Milwaukee, Wisconsin. It charged him with unlawful flight to avoid prosecution for the attempted murder of an off-duty Milwaukee police officer. (He was acquitted of the attempted murder charge in February 1978.) During this time period, Peltier had seven children from two marriages and adopted two children. Shootout at Pine Ridge On June 26, 1975, Special Agents Jack R. Coler and Ronald A. Williams of the Federal Bureau of Investigation (FBI) were on the Pine Ridge Indian Reservation searching for a young man named Jimmy Eagle, who was wanted for questioning in connection with the recent assault and robbery of two local ranch hands. Eagle had been involved in a physical altercation with a friend, during which he had stolen a pair of leather cowboy boots. At approximately 11:50 a.m., Williams and Coler, driving two separate unmarked cars, spotted, reported, and followed a red pick-up truck that matched the description of Eagle's. Soon after his initial report, Williams radioed to a local dispatch that he and Coler had come under fire from the occupants of the vehicle. Williams radioed that they would be killed if reinforcements did not arrive. He next radioed that they both had been shot. FBI Special Agent Gary Adams was the first to respond to Williams' call for assistance, and he also came under gunfire; Adams was unable to reach Coler and Williams in time, and both agents died within the first ten minutes of gunfire. At about 4:25 p.m., authorities recovered the bodies of Williams and Coler from their vehicles. The FBI reported that Williams had received a defensive wound to his right hand (as he attempted to shield his face) from a bullet that passed through his hand into his head, killing him instantly. Williams received two gunshot injuries, to his body and foot, prior to the contact shot that killed him. Coler, incapacitated from earlier bullet wounds, had been shot twice in the head. In total, 125 bullet holes were found in the agents' vehicles, many from a .223 Remington rifle. The shooters took apart Williams's car and stole four guns belonging to the agents. Aftermath At least three men were arrested in connection with the shooting: Peltier, Robert Robideau, and Darrelle "Dino" Butler, all AIM members who were present on the Jumping Bull compound at the time of the shootings. Leonard Peltier provided numerous alibis to several people about his activities on the morning of the attacks. In an interview with the author Peter Matthiessen (In the Spirit of Crazy Horse 1983), Peltier described working on a car in Oglala, claiming to have driven back to the Jumping Bull Compound about an hour before the shooting started. In an interview with Lee Hill, he described being awakened in the tent city at the ranch by the sound of gunshots. To Harvey Arden, for Prison Writings, he described enjoying a beautiful morning before he heard the firing. On September 5, 1975, Agent Coler's .308 rifle and handgun and Agent Williams's handgun were recovered from an automobile in the vicinity of Butler's arrest location. The FBI forwarded a description of a recreational vehicle (RV) and the Plymouth station wagon recently purchased by Peltier to law enforcement during the hunt for the suspects. The RV was stopped by an Oregon State Trooper, but the driver, later discovered to be Peltier, fled on foot following a small shootout. Both Peltier's thumbprint and Agent Coler's handgun were discovered under the RV's front seat. On September 10, 1975, AIM members Robert Robideau, Norman Charles, and Michael Anderson were injured in the explosion of a station wagon on the Kansas Turnpike close to Wichita. Agent Coler's .308 rifle and an AR-15 rifle were found in the burned vehicle. Trial On December 22, 1975, Peltier was named to the FBI Ten Most Wanted Fugitives list. On February 6, 1976, Peltier was arrested at Robert Smallboy's camp along the Brazeau River south of Hinton, Alberta. In December 1976, he was extradited from Canada based on documents submitted by the FBI. Warren Allmand, Canada's Solicitor General at the time, later stated that these documents contained false information. One of those documents was an affidavit signed by Myrtle Poor Bear, a Native American woman local to the area near Pine Ridge Reservation. While Poor Bear stated that she was Peltier's girlfriend during that time and watched the killings, Peltier and others at the scene said that Poor Bear did not know Peltier and was not present during the murders. Poor Bear later admitted to lying to the FBI, but said that the agents interviewing her had coerced her into making these claims above. When Poor Bear tried to testify against the FBI, the judge barred her testimony because of mental incompetence. Peltier fought extradition to the United States. Robideau and Butler were acquitted on the grounds of self-defense by a federal jury in Cedar Rapids, Iowa. Peltier returned too late to be tried with Robideau and Butler, and he was subsequently tried separately. Peltier's trial was held in Fargo, North Dakota, where a jury convicted Peltier of the murders of Coler and Williams. Unlike the testimony in the trial for Butler and Robideau, the jury was informed that the two FBI agents were killed by close-range shots to their heads, when they were already defenseless due to previous gunshot wounds. Consequently, Peltier could not submit a self-defense testimony that may have resulted in an acquittal. The jury was also shown autopsy and crime scene photographs of the two agents, which had not been shown to the jury at Cedar Rapids. In April 1977, Peltier was convicted and sentenced to two consecutive life sentences. Inconsistencies in the prosecution's case Numerous doubts have been raised over Peltier's guilt and the fairness of his trial, based on allegations and inconsistencies regarding the FBI and prosecution's handling of this case. Several key witnesses in the initial trial have recanted their statements and admitted they were made under duress at the hands of the FBI. At least one witness was given immunity from prosecution in exchange for testimony against Peltier. Recanted witness statements Peltier was convicted in 1977 largely on the evidence presented by three witness affidavits, all signed by Myrtle Poor Bear, that placed him at the scene of the shootout and contended that Peltier planned his crimes. Poor Bear claimed to be Peltier's girlfriend at the time, but later admitted that she never knew him personally. Moreover, Poor Bear was known to be mentally unstable. This was confirmed when the FBI deemed her unfit to testify at court. But her testimony, as put forth in her previous affidavits, remained a key part of the prosecution's case against Peltier. Two other witnesses whose testimony was used to place Peltier at the scene of the crime also later recanted. They alleged that the FBI had coerced and threatened them by tying them to chairs, denying them their right to talk to their attorney, and otherwise intimidated them. Discrepancies in material evidence FBI radio intercepts indicated that the two FBI agents Williams and Coler had entered the Pine Ridge Reservation in pursuit of a suspected thief in a red pickup truck. The FBI confirmed this claim the day after the shootout, but red pickup trucks near the reservation had been stopped for weeks, and Leonard Peltier did not drive a red pickup truck. Evidence was given that Peltier was driving a Chevrolet Suburban; a large station wagon-style sedan built on a pickup truck chassis, with an enclosed rear section. Peltier's vehicle was orange with a white roof—not a red, open-tray pickup truck with no white paint. At Peltier's trial, the FBI changed their previous statements that they had been in search of a red pickup truck and instead said that they were looking for an orange and white van, similar to the one Peltier drove. This contradictory statement by the FBI was a highly contentious matter of evidence in the trials. Though the FBI's investigation indicated that an AR-15 was used to kill the agents, several different AR-15s were in the area at the time of the shootout. Also, no other cartridge cases or evidence about them were offered by the prosecutor's office, although other bullets were fired at the crime scene. During the trial, all the bullets and bullet fragments found at the scene were provided as evidence and detailed by Cortland Cunningham, FBI Firearms expert, in testimony (Ref US v. Leonard Peltier, Vol 9). Years later, a request under the Freedom of Information Act prompted another examination of the FBI ballistics report used to convict Peltier. An impartial expert evaluated the firing pin linked to the gun that shot Williams and Coler and concluded that the cartridge case from the scene of the crime did not come from the rifle tied to Peltier. This evidence negated a key facet of the prosecution's case against Peltier. The court did not allow the defense to present the Fargo jury with information about other cases in which the FBI had been rebuked for tampering with evidence and witnesses. In some similar prosecutions against AIM leaders at the time, defense attorneys did present such evidence to the juries. 1979 prison escape Peltier began serving his sentences in 1977. On July 20, 1979, he and two other inmates escaped from Federal Correctional Institution, Lompoc. One inmate was shot dead by a guard outside the prison and the other was captured 90 minutes later, approximately away. Peltier remained at large until he was captured by a search party three days later near Santa Maria, California, after a farmer alerted authorities that Peltier had consumed some of his crops for food. Peltier was later apprehended without incident. As he was in possession of a Ruger Mini-14 rifle at the time of his capture, Peltier was convicted and sentenced to serve a five-year sentence for escape and a two-year sentence for being a felon in possession of a firearm, in addition to his preexisting two life sentences. Clemency appeals Support for clemency Peltier's conviction sparked great controversy and has drawn criticism from a number of prominent figures across a wide range of disciplines. In 1999, Peltier asserted on CNN that he did not commit the murders and that he has no knowledge who shot the FBI agents nor knowledge implicating others in the crime. Peltier has described himself as a political prisoner. Numerous public and legal appeals have been filed on his behalf; however, due to the consistent objection of the FBI, none of the resulting rulings has been made in his favor. His appeals for clemency received support from world famous civil rights advocates including Nelson Mandela, Archbishop Desmond Tutu, and Rev. Jesse Jackson, Tenzin Gyatso (the 14th Dalai Lama), Nobel Peace Prize Laureate and activist Rigoberta Menchú, and Mother Teresa. International government entities such as the Office of the United Nations High Commissioner on Human Rights, the United Nations Working Group on Indigenous Populations, the European Parliament, the Belgian Parliament, and the Italian Parliament have all passed resolutions in favor of Peltier's clemency. Moreover, several human rights groups including The International Federation of Human Rights and Amnesty International have launched campaigns advocating for Peltier's clemency. In the United States, the Kennedy Memorial Center for Human Rights, the Committee of Concerned Scientists, Inc., the National Lawyers Guild, and the American Association of Jurists are all active supporters of clemency for Peltier. The police officer that arrested Peltier is convinced that he "was extradited illegally and that he didn't get a fair trial in the United States." Denial of clemency In 1999, Peltier filed a habeas corpus petition, but it was rejected by the 10th Circuit Court on November 4, 2003. Near the end of the Clinton administration in 2001, rumors began circulating that Bill Clinton was considering granting Peltier clemency. Opponents of Peltier campaigned against his possible clemency; about 500 FBI agents and families protested outside the White House, and FBI director Louis Freeh sent a letter opposing Peltier's clemency to the White House. Clinton did not grant Peltier clemency. In 2002, Peltier filed a civil rights lawsuit in the U.S. District Court for the District of Columbia against the FBI, Louis Freeh and FBI agents who had participated in the campaign against his clemency petition, alleging that they "engaged in a systematic and officially sanctioned campaign of misinformation and disinformation." On March 22, 2004, the suit was dismissed. In January 2009, President George W. Bush denied Peltier's clemency petition before leaving office. In 2016, Peltier's attorney's filed a clemency application with the White House's Office of the Pardon Attorney, and his supporters organized a campaign to convince President Barack Obama to commute Peltier's sentence, a campaign which included an appeal by Pope Francis, as well as James Reynolds, a senior attorney and former US Attorney who supervised the prosecution against Peltier in the appeal period following his initial trial. In a letter to the United States Department of Justice, Reynolds wrote that clemency was "in the best interest of justice in considering the totality of all matters involved". In a subsequent letter to the Chicago Tribune, Reynolds added that the case against Peltier "was a very thin case that likely would not be upheld by courts today. It is a gross overstatement to label Peltier a 'cold-blooded murderer' on the basis of the minimal proof that survived the appeals in his case." On January 18, 2017, two days before President Obama left office, the Office of the Pardon Attorney announced that Obama had denied Peltier's application for clemency. On June 8, 2018, KFGO Radio in Fargo, N.D., reported that Peltier filed a formal clemency request with President Trump. KFGO obtained and published a letter that was sent by Peltier's attorney to the White House. Remaining questions In the documentary film Incident at Oglala (1992), AIM activist Robert Robideau said that the FBI agents had been shot by a 'Mr X'. When Peltier was interviewed about 'Mr X', he said he knew who the man was. Dino Butler, in a 1995 interview with E.K. Caldwell of News From Indian Country, said that 'Mr X' was fictional and had been named as the murderer in an attempt to gain Peltier's release from prison. In a 2001 interview with News From Indian Country, Bernie Lafferty said that she had witnessed Peltier's referring to his murder of one of the agents. Later developments 2002 editorial about deaths of agents and Aquash In January 2002 in the News from Indian Country, publisher Paul DeMain wrote an editorial that an "unnamed delegation" told him that Peltier had murdered the FBI agents. DeMain described the delegation as "grandfathers and grandmothers, AIM activists, Pipe carriers and others who have carried a heavy unhealthy burden within them that has taken its toll." DeMain said he was also told that the motive for the execution-style murder of high-ranking AIM activist Anna Mae Aquash in December 1975 at Pine Ridge "allegedly was her knowledge that Leonard Peltier had shot the two agents, as he was convicted." DeMain did not accuse Peltier of participation in the Aquash murder. In 2003 two Native American men were indicted and later convicted of the murder. On May 1, 2003, Peltier sued DeMain for libel for similar statements about the case published on March 10, 2003, in News from Indian Country. On May 25, 2004, Peltier withdrew the suit after he and DeMain settled the case. DeMain issued a statement saying he did not think Peltier was given a fair trial for the two murder convictions, nor did he think Peltier was connected to Aquash's death. DeMain stated he did not retract his allegations that Peltier was guilty of the murders of the FBI agents and that the motive for Aquash's murder was the fear that she might inform on the activist. Indictments and trials for the murder of Aquash In 2003 there were federal grand jury hearings on charges against Arlo Looking Cloud and John Graham for the murder of Anna Mae Aquash. Bruce Ellison, Leonard Peltier's lawyer since the 1970s, was subpoenaed and invoked his Fifth Amendment rights against self-incrimination, refusing to testify. He also refused to testify, on the same grounds, at Looking Cloud's trial in 2004. During the trial, the federal prosecutor named Ellison as a co-conspirator in the Aquash case. Witnesses said that Ellison participated in interrogating Aquash about being an FBI informant on December 11, 1975, shortly before her murder. In February 2004, Fritz Arlo Looking Cloud, an Oglala Sioux, was tried and convicted of the murder of Aquash. In Looking Cloud's trial, the federal prosecution argued that AIM leaders' suspicion of Aquash stemmed from her having heard Peltier admit to the murders. Darlene "Kamook" Nichols, former wife of AIM leader Dennis Banks, was a witness for the prosecution. She testified that in late 1975, Peltier told her and a small group of AIM fugitive activists about shooting the FBI agents. At the time, all were fleeing law enforcement after the Pine Ridge shootout. The other fugitives included her sister Bernie Nichols, her husband Dennis Banks, and Aquash, among several others. Bernie Nichols-Lafferty testified with a similar account of Peltier's statement. Earlier in 1975, AIM member Douglass Durham had been revealed to be an undercover FBI agent and dismissed from the organization. AIM leaders were fearful of infiltration. Other witnesses have testified that, when Aquash was suspected of being an informant, Peltier interrogated her while holding a gun to her head. Peltier and David Hill were said to have Aquash participate in bomb-making so that her fingerprints would be on the bombs. Prosecutors alleged in court documents that the trio planted these bombs at two power plants on the Pine Ridge Indian Reservation on Columbus Day 1975. During the trial, Nichols acknowledged receiving $42,000 from the FBI in connection with her cooperation on the case. She said it was compensation for travel expenses to collect evidence and moving expenses to be farther from her ex-husband Dennis Banks, whom she feared because she had implicated him as a witness. Peltier has claimed that Kamook Nichols committed perjury with her testimony. On June 26, 2007, the Supreme Court of British Columbia ordered the extradition of John Graham to the United States to stand trial for his alleged role in the murder of Aquash. He was eventually tried by the state of South Dakota in 2010. During Graham's trial, Darlene "Kamook" Ecoffey said Peltier told both her and Aquash that he had killed the FBI agents in 1975. Ecoffey testified under oath, "He (Peltier) held his hand like this", she said, pointing her index finger like a gun, "and he said 'that (expletive) was begging for his life but I shot him anyway.'" Graham was convicted of murdering Aquash and sentenced to life in prison. Presidential politics Peltier was the candidate for the Peace and Freedom Party in the 2004 election for President of the United States. While numerous states have laws that prohibit prison inmates convicted of felonies from voting (Maine and Vermont are exceptions), the United States Constitution has no prohibition against felons being elected to federal offices, including President. The Peace and Freedom Party secured ballot status for Peltier only in California. His presidential candidacy received 27,607 votes, approximately 0.2% of the vote in that state. In 2020 he ran as the vice-presidential running mate of Gloria La Riva, on the ticket of the Party for Socialism and Liberation in the presidential campaign. He was forced to resign from the ticket for health reasons in early August 2020, and was replaced with Sunil Freeman. Ruling on FBI documents In a February 27, 2006, decision, U.S. District Judge William Skretny ruled that the FBI did not have to release five of 812 documents relating to Peltier and held at their Buffalo field office. He ruled that the particular documents were exempted on the grounds of "national security and FBI agent/informant protection". In his opinion, Judge Skretny wrote, "Plaintiff has not established the existence of bad faith or provided any evidence contradicting (the FBI's) claim that the release of these documents would endanger national security or would impair this country's relationship with a foreign government." In response, Michael Kuzma, a member of Peltier's defense team, said, "We're appealing. It's incredible that it took him 254 days to render a decision." Kuzma further said, "The pages we were most intrigued about revolved around a teletype from Buffalo ... a three-page document that seems to indicate that a confidential source was being advised by the FBI not to engage in conduct that would compromise attorney-client privilege." Peltier's supporters have tried to obtain more than 100,000 pages of documents from FBI field offices, claiming that the files should have been turned over at the time of his trial or following a Freedom of Information Act (FOIA) request filed soon after. Victim of prison violence On January 13, 2009, Peltier was beaten by inmates at the United States Penitentiary, Canaan, where he had been transferred from USP Lewisburg. He was sent back to Lewisburg, where he remained until the fall of 2011, when he was transferred to a federal penitentiary in Florida. As of 2016, Leonard Peltier is housed at Coleman Federal Correctional Complex in Coleman, Florida. In popular culture Sculpture In 2016, a statue of Peltier, based on a self portrait he made in prison, was created by artist Rigo 23 and installed on the grounds of American University in Washington, D.C.. After the university received complaints from the FBI Agents Association, the statue was removed and relocated to the Main Museum in Los Angeles. Films Incident at Oglala: The Leonard Peltier Story (1992) is a documentary by Michael Apted about Peltier and narrated by Robert Redford. The film argues in favour of the assertion that the government's prosecution of Peltier was unjust and politically motivated. Thunderheart (1992) is a fictional movie by Michael Apted, partly based on Peltier's case but with no pretense to accuracy. Warrior, The Life of Leonard Peltier (1992) is a feature documentary film about Peltier's life, the American Indian Movement, and his trial directed by Suzie Baer. The film argues that the government's prosecution of Peltier was unjust and motivated by the hugely profitable energy interests in the area. Music Free Salamander Exhibit released the song "Undestroyed" on December 13, 2016. The lyrics are drawn nearly verbatim from Peltier's book, Prison Writings: My Life Is My Sun Dance. Little Steven released the song "Leonard Peltier" on his 1989 album Revolution. The song discusses Peltier's case and the struggle of the Native Americans. The Indigo Girls popularized Buffy St. Marie's song, "Bury My Heart at Wounded Knee", with a cover on their 1995 live album 1200 Curfews. The song mentions Peltier, saying, "the bullets don’t match the gun." Sixteen Canadian artists contributed to Pine Ridge: An Open Letter to Allan Rock – Songs for Leonard Peltier, a benefit CD released in 1996 by What Magazine. Toad the Wet Sprocket reference Peltier, as well as the conflict at Pine Ridge and the Wounded Knee massacre, in their song "Crazy Life" on their album Coil: What have you done with Peltier? (1997) Anal Cunt released the song "Laughing While Lennard Peltier Gets Raped In Prison" as apart of their album It Just Gets Worse. U2 recorded the song "Native Son" about Peltier. It was later reworked into their hit song "Vertigo" on their album, How to Dismantle an Atomic Bomb (2004). Five years later, "Native Son" was released on their digital album Unreleased and Rare (2009). Bring Leonard Peltier Home in 2012 was a concert that took place at the Beacon Theatre in New York City. The concert featured Pete Seeger, Harry Belafonte, Jackson Browne, Common, Mos Def, Michael Moore, Danny Glover, Rubin "Hurricane" Carter, Bruce Cockburn, Margo Thunderbird, Silent Bear, Bill Miller, etc. all standing up for the immediate release of Leonard Peltier. In 2015, Sarah Meyer, formerly of the band Velveteen Dream, released a cover of Toad the Wet Sprocket's "Crazy Life" from their 1997 album Coil, which asks, "What have you done with Peltier?" Their SoundCloud single features an image of Sacheen Littlefeather, the Native American civil rights activist who served as a proxy for Marlon Brando when he was awarded a 1973 Academy Award for Academy Award for Best Actor for starring in The Godfather. Brando was involved in AIM with Peltier during the early 1970s and sought Littlefeather's help in 1973 to protest the ongoing Wounded Knee Incident standoff. Rage Against The Machine's 1994 "Freedom" video clip shows footage of the case and ends with a picture of Peltier in prison and the phrase "justice has not been done". "Sacrifice" from Contact from the Underworld of Redboy, the 1998 music recording by Robbie Robertson (formerly of The Band), features voice recordings of Peltier throughout the song, and surrounded with melody and vocals. The song ends with Peltier alone sayin, "I've gone too far now to start backing down. I don't give up. Not 'til my people are free will I give up and if I have to sacrifice some more, then I sacrifice some more." French singer Renaud released a song called "Leonard's Song" in his 2006 album Rouge Sang. It supports Peltier and Native American rights, comparing in its lyrics the foundation of America to conducting an equivalent of The Holocaust against the Native American people. Alternative hip-hop trio The Goats mention Peltier several times on their 1992 debut album Tricks of the Shade: in a track entitled "Leonard Peltier in a Cage", and in the song "Do the Digs Dug" (which also mentions activist Annie Mae Aquash – lyrics referencing them are "Leonard Peltier Leonard Peltier Who da hell is that, why the f* should ya care? In jail, in jail, in jail like a dealer F* George Bush says my T-Shirt squeeler Please oh please set Leonard P. free Cause ya wiped out his race like an ant colony Whatcha afraid of, Annie Mae Aquash? Found her lying in the ditch with no place for a watch") Other It was reported by Joseph Corré that the last words of his father, Malcolm McLaren, were "Free Leonard Peltier". Publications Arden, Harvey (& Leonard Peltier). "Have You Thought of Leonard Peltier Lately?" HYT Publishing, 2004. . Peltier, Leonard. Prison Writings: My Life Is My Sun Dance. New York, 1999. . See also List of memoirs of political prisoners List of longest prison sentences served Category:Native American activists Lapu Lapu Omar Mukhtar Chino Roces References Further reading "Writer Sues Peltier", Kansas City Star, July 3, 1992. Anderson, Scott. "The Martyrdom of Leonard Peltier", Outside Magazine, July 1995. Churchill, Ward and Jim Vander Wall: Agents of Repression: The FBI's Secret Wars Against the Black Panther Party and the American Indian Movement. South End Press, Cambridge, Massachusetts, 1988, 2002. . Churchill, Ward and Jim Vander Wall: The COINTELPRO Papers: Documents from the FBI's Secret Wars Against Dissent in the United States. South End Press, Cambridge, Massachusetts, 1990, 2002. . Matthiessen, Peter (1983). In the Spirit of Crazy Horse. Penguin. . Messerschmidt, Jim or also known as James W. Messerschmidt. The Trial of Leonard Peltier. South End Press, Boston, Massachusetts, 1983. . External links Native American Activist Leonard Peltier's Jailhouse Plea for Long-Denied Clemency, an interview with Peter Coyote on Democracy Now!, December 13, 2012 The Leonard Peltier Trial (Documents) Interview with Leonard Peltier from jail in 2000 by Democracy Now! Plazm magazine — Interview with Leonard Peltier from jail in 1995 Documents from Leonard Peltier's FBI File Federal Bureau of Investigation, Minneapolis Division: Leonard Peltier Case Leonard Peltier Memorial Bridge Leonard Peltier on Earth Liberation Prisoners Support Network No Parole Peltier Association International Leonard Peltier Defense Committee (archived) A.I.M (the American Indian Movement) Parole Hearing to Be Held Tuesday for Imprisoned Native American Activist Leonard Peltier – video report by Democracy Now! July 27, 2009 the yet official Leonard Peltier ~ Defense Offense Committee – LP-DOC(since May 2008) 1944 births 1975 murders in the United States 2020 United States vice-presidential candidates 20th-century Native Americans 21st-century Native Americans Dakota people Lakota people Ojibwe people Living people Members of the American Indian Movement Native American activists Native American artists Native American writers Native American candidates for Vice President of the United States American people of French descent American escapees 20th-century American memoirists Escapees from United States federal government detention FBI Ten Most Wanted Fugitives People extradited from Canada to the United States People convicted of murder by the United States federal government People convicted of murdering FBI agents Prisoners sentenced to life imprisonment by the United States federal government American people convicted of murdering police officers American prisoners sentenced to life imprisonment Peace and Freedom Party presidential nominees Candidates in the 2004 United States presidential election People from Grand Forks, North Dakota	[ 0.23353752493858337, 0.5619630813598633, -0.7846952676773071, -0.15985913574695587, 0.39338424801826477, 0.35064181685447693, 0.9218927621841431, -0.19026339054107666, -0.07689368724822998, -0.008337881416082382, 0.46783652901649475, 0.39067086577415466, -0.3482891321182251, 0.110274799168...
18221	https://en.wikipedia.org/wiki/LambdaMOO	LambdaMOO	LambdaMOO is an online community of the variety called a MOO. It is the oldest MOO today. LambdaMOO was founded in 1990 by Pavel Curtis at Xerox PARC. Now hosted in the state of Washington, it is operated and administered entirely on a volunteer basis. Guests are allowed, and membership is free to anyone with an e-mail address. LambdaMOO gained some notoriety when Julian Dibbell wrote a book called My Tiny Life describing his experiences there. Over its history, LambdaMOO has been highly influential in the examination of virtual-world social issues. History LambdaMOO has its roots in the 1978–1980 work by Roy Trubshaw and Richard Bartle to create and expand the concept of Multi-User Dungeon (MUD) – virtual communities. Around 1987–1988, the expansion of the global internet allowed more users to experience the MUD. Pavel Curtis at Xerox Parc noted that they were "almost exclusively for recreational purposes." Curtis determined to explore whether the MUD could be non-recreational. He developed LambdaMOO software to run on the LambdaMOO server, which implements the MOO programming language. This software was subsequently made available to the public. Several starter databases, known as cores, are available for MOOs; LambdaMOO itself uses the LambdaCore database. The "Lambda" name is from Curtis's own username on earlier MUD systems. LambdaMOO can refer to the software, the server, or the community of users. Geography LambdaMOO central geography was based on Pavel Curtis's California home. New players and guests traditionally connected in "The Coat Closet", but a second area, "The Linen Closet" (specially programmed as a silent area) was later added as an alternative connection point. The coat closet opens onto the center of the house in The Living Room, a common hangout and place for conversation; its fixtures include a fireplace (where things can be roasted), The Living Room Couch (which periodically causes players' objects to 'fall through' to underneath the couch), and a pet Cockatoo who repeats overheard phrases (which is sometimes found with its beak gagged). Occasionally, the Cockatoo is replaced with a more seasonal creature: a Turkey near Thanksgiving, a Raven near Halloween, et cetera. To the north of the Living Room is the Entrance Hall, the Front Yard, and a limited residential area along LambdaStreet. There is an extensive subterranean complex located down the manhole, including a sewage system. Players walking to the far west along LambdaStreet may be given the option to 'jump off the edge of the world', which disables access to their account for three months. To the south of the Living Room is a pool deck, a hot tub, and some of the extensive grounds of the mansion, featuring gardens, hot air balloon landing pads, open fields, fishing holes, and the like. To the northwest of the living room are the laundry room, garage, dining room, smoking room, drawing room, housekeeper's quarters, and kitchen. To the east of the entry hall, hallways provide access to some individual rooms, the Linen Closet, and to the eastern wing of the house. In the eastern wing can be found the Library of online books, the Museum of generic objects (which account-holders may create instances of), and an extensive area for the LambdaMOO RPG. Since the creation of the original LambdaMOO map, many users have expanded the MOO by making additional rooms with the command "@dig." Politics While most MOOs are run by administrative fiat, in summer of 1993 LambdaMOO implemented a petition/ballot mechanism, allowing the community to propose and vote on new policies and other administrative actions. A petition may be created by anyone eligible to participate in politics (those who have maintained accounts at the MOO for at least 30 days), can be signed by other players, and may then be submitted for administrative 'vetting'. Once vetted, the petition has a limited time to collect enough signatures to become valid and be made into a ballot. Ballots are subsequently voted on; those with a 66% approval rating are passed and will be implemented. This system suffered quite a lot of evolution and eventually passed into a state where wizards took back the power they'd passed into the hands of the people, but still maintain the ballot system as a way for the community to express its opinions. Demographics The population of LambdaMOO numbered close to 10,000 around 1994, with over 300 actively connected at any time. See also "A Rape in Cyberspace" References External links Status blog LiveJournal community MU* games Video games developed in the United States Xerox spin-offs	[ 0.17204682528972626, 0.12745949625968933, -0.4073919653892517, -0.09221482276916504, -0.35795748233795166, -0.24254348874092102, 0.37883174419403076, 0.7162193655967712, -0.4534396231174469, 0.06072964519262314, -0.609928548336029, 0.15686479210853577, -0.06233641505241394, -0.091457001864...
18223	https://en.wikipedia.org/wiki/Lorica%20segmentata	Lorica segmentata	The lorica segmentata (), also called lorica lamminata (; see §Name), is a type of personal armour that was used by soldiers of the Roman Empire, consisting of metal strips fashioned into circular bands, fastened to internal leather straps. The lorica segmentata has come to be viewed as iconic of the Roman legions in popular culture. The tendency to portray Roman legionaries clad in this type of armour often extends to periods of time that are too early or too late in history. History Despite the armor being commonly associated with the Romans, the armor was used by other civilizations before the Romans. The armor was originally used by the Parthians and possibly the Dacians, Scythians, or Sarmatians before the Romans used it. Some sets of armor similar to the lorica segmentata dating back to the 4th century BC have been found in archaeological sites located in the steppe. The Dendra Cuirass is a set of armor similar to the lorica segmentata that has been dated back to the 15th century BC. The armor was first used in the early 1st century. Although, the exact time in which the Romans adopted the armor remains unknown. Some say it was after Crassus' defeat at Carrhae in 53 BC. Others say the armor was adopted in 21 AD after the Revolt of Julius Sacrovir and Julius Florus. One form of the armor was used as early as 9 AD. Because the soldiers at the Battle of Teutoberg Forest wore the lorica segmentata, we can conclude the armor must have been in use before 21 AD. Around the middle of the third century the lorica segmentata fell out of favor with the Roman army. Although, it did remain in use during the Late Roman Empire. The armor was still around in the 4th century. Soldiers wearing the lorica segmentata were depicted on the Arch of Constantine, a monument erected in 315. However, it has been argued that these depictions are from an earlier monument by Marcus Aurelius, from which Constantine incorporated portions into his Arch. The latest known use of the armor was in the 4th century. Over time the type of lorica segmentata would change. From 9 BC to 43 AD the Roman soldier wore the Dngestetten-Kalkriese-Vindonissa type, from 69 to 100 the Corbridge-Carnuntum was used and from 164 to 180 Newstead type was used. The time the armors were worn would overlap. It is possible that there was a fourth type, covering the body with segmented armour joined to scale shoulder defences. However, this is only known from one badly-damaged statue originating at Alba Iulia in Romania. The currently accepted range for the use of the armour is from about 14 B.C. to the late 3rd century A.D. The lorica segmentata's use in the Roman army was geographically widespread, but the mail armor lorica hamata may have been more common at all times. Usage in the Roman Army The question as to precisely who used the armour is debated. On the monument, Auxilia are generally shown wearing mail, cuirasses, and carrying oval shields. Legionaries are uniformly depicted wearing the lorica segmentata and carrying the curved rectangular shield. On this basis, it has been supposed that lorica segmentata was exclusively used by legionaries and praetorians. However, some historians consider Trajan's Column to be inaccurate as a historical source due to its inaccurate and stylised portrayal of Roman armour. These historians also say that "it is probably safest to interpret the Column reliefs as 'impressions', rather than accurate representations." The discovery of parts of the lorica segmentata at areas where auxiliary soldiers would have been stationed implies that auxiliary troops used the lorica segmentata. However, it is entirely possible that the reason behind the presence of the lorica segmentata in these areas could because these areas had a small number of legionaries stationed there. On the Adamclisi Tropaeum, the lorica segmentata does not appear at all, and legionaries and auxilia alike are depicted wearing the lorica squamata. Some experts are of the opinion that the Adamclisi monument is a more accurate portrayal of the situation, the segmentata used rarely, maybe only for set-piece battles and parades. This viewpoint considers the figures in Trajan's Column to be highly stereotyped, in order to distinguish clearly between different types of troops. It's also debated if the lorica segmentata was only used in the west. Every archaeological find of such armour has been made in the western part of the Roman Empire but never in the east. Forging The plates in the lorica segmentata armour were made by overlapping ferrous plates that were then riveted to straps made from leather. It is unknown what animal was used to make the leather and if the leather was tanned or tawed. The plates were soft iron on the inside and rolled mild steel on the outside, making the plates hardened against damage without becoming brittle. This case hardening was done by packing organic matter tightly around them and heating them in a forge, transferring carbon from the burnt materials into the surface of the metal. The plates were made from beating out ingots. The strips were arranged horizontally on the body, overlapping downwards, and they surrounded the torso in two halves, being fastened at the front and back. The upper body and shoulders were protected by additional strips ("shoulder guards") and breast- and backplates. The form of the armour allowed it to be stored very compactly, since it was possible to separate it into four sections, each of which would collapse on itself into a compact mass. The fitments that closed the various plate sections together (buckles, lobate hinges, hinged straps, tie-hooks, tie-rings, etc.) were made of brass. In later variants dating from around 75–80 A.D., the fastenings of the armour were simplified. Bronze hinges were removed in favour of simple rivets, belt fastenings utilized small hooks, and the lowest two girdle plates were replaced by one broad plate. The component parts of the lorica segemtata moved in synchronization with the other parts. This made it so the armor was more flexible. The armor was very long lasting. The Kalkriese type of armor lasted 55 years. the Corbridge armor lasted 70 years, and the Newsteadtype lasted 90 years. Despite the longevity of the armor, all evidence points to the armor being very fragile. Name In Latin, the name lorica segmentata translates to "segmented cuirass." However, this name was not given to the armor by the Romans. Instead, it was given by scholars in the 16th century. Despite the lack of knowledge on the Roman name for the armor, scholars can make educated guesses on the Roman name. It is obvious the name had the word lorica in its name. However, the following part of the name is unknown. Some scholars believe that the name was lorica lamminata. This theory is based of the fact that the Romans referred to sheets of metal as lamina. Although, there is no firm evidence for any theory regarding the name of the armor. See also Laminar armour Manica – Roman armguard of similar construction Lorica plumata Lorica hamata Lorica squamata References Bibliography External links Lorica Segmentata Volume I: A Handbook of Articulated Roman Plate Armour, M.C. Bishop, Armatura Press (November 1, 2002) (online version) Roman Army website, showing the third century finds of segmentata in spain (downloadable PDF) Ancient originals on the pages of the Roman Military Equipment Web Museum Ancient Roman legionary equipment Roman armour	[ -0.19872689247131348, -0.7126169800758362, -0.05524406209588051, 0.549141526222229, -0.1917724907398224, 0.6247547268867493, 0.12672452628612518, 0.05046653002500534, -0.6053978204727173, -0.14669941365718842, -0.23772969841957092, 0.5716601610183716, -0.3977234959602356, 0.043616671115159...
18224	https://en.wikipedia.org/wiki/Known%20Space	Known Space	Known Space is the fictional setting of about a dozen science fiction novels and several collections of short stories written by Larry Niven. It has also become a shared universe in the spin-off Man-Kzin Wars anthologies. ISFDB catalogs all works set in the fictional universe that includes Known Space under the series name Tales of Known Space, which was the title of a 1975 collection of Niven's short stories. The first-published work in the series, which was Niven's first published piece was "The Coldest Place", in the December 1964 issue of If magazine, edited by Frederik Pohl. This was the first-published work in the 1975 collection. The stories span approximately one thousand years of future history, from the first human explorations of the Solar System to the colonization of dozens of nearby systems. Late in the series, Known Space is an irregularly shaped "bubble" about 60 light-years across. Within the Tales of Known Space, the epithet "Known Space" refers to a relatively small region in the Milky Way galaxy, one centered on Earth. In the future that the series depicts, spanning roughly the third millennium, humans have explored this region and colonized many of its worlds. Contact has been made with other species, such as the two-headed Pierson's Puppeteers and the aggressive felinoid Kzinti. Stories in the Known Space series include events and places outside of the region called "Known Space" such as the Ringworld, the Pierson's Puppeteers' Fleet of Worlds and the Pak homeworld. The Tales were originally conceived as two separate series, the Belter stories set roughly from 2000 to 2350 CE and the Neutron Star / Ringworld stories set in 2651 CE and later. The earlier, Belter period features solar-system colonization and slower-than-light travel with fusion-powered and Bussard ramjet ships. The later, Neutron Star, period features faster-than-light ships using "hyperdrive". Niven implicitly joined the two settings as a single fictional universe in the short story "A Relic of the Empire" (If, December 1966), by using background elements of the Slaver civilization from the Belter series as a plot element in the faster-than-light setting. In the late 1980s—having written almost no Tales of Known Space in more than a decade—Niven opened the 300-year gap in the Known Space timeline as a shared universe, and the stories of the Man-Kzin Wars volumes fill in that history, bridging the two settings. Locations One aspect of the Known Space universe is that most of the early human colonies are on planets suboptimal for Homo sapiens. During the first phase of human interstellar colonization (i.e. before humanity acquired FTL), simple robotic probes were sent to nearby stars to assess their planets for habitation. The programming of these probes was flawed: they sent back a "good for colonization" message if they found a habitable point, rather than a habitable planet. Sleeper ships containing human colonists were sent to the indicated star systems. Too often, those colonists had to make the best of a bad situation. Earth, the human homeworld, is ruled by the United Nations, a direct democracy, but not a utopia. An important organization is the ARM, a global police force tasked to deal with organlegging and crimes committed by cutting edge technologies. For centuries, due to the perfection of organ transplant technology, all state executions were done in hospitals to provide organ transplants, and to maximize their availability nearly all crimes carried the death penalty, including such offenses as multiple traffic tickets or tax evasion. This period ended when Jack Brennan, who had consumed the Tree-of-Life root and become a human version of the Pak Protector, used his superior intelligence to engineer social change in medical technology and social attitudes that eventually reduced the use of organ banks to reasonable levels. Part of Brennan's manipulation was the development of a science known as "psychistry". Psychistry was used to "correct" all forms of "mental aberration" - the populace is extremely docile. To combat overpopulation (one estimate is 18 billion people), a license is required to procreate, only available after exhaustive testing has determined that a prospect is free of "abnormalities"; unlicensed procreation is a capital crime. This policy, in addition to the existence of the transfer booth and a one-world language and economy, has led to the populace eventually becoming fairly genetically homogeneous. To prevent the development of new WMDs, all scientific research is regulated by the government and potentially dangerous technology is suppressed. Due to such suppression, Earth has had fewer real breakthroughs in science than would be expected. A common title for people born on Earth is "Flatlander"; having been born and raised in the only environment in Known Space to which humans are well-adapted, they are considered naïve and a bit helpless by humans from colony worlds. The Moon is a separate entity, with its own distinct culture but is under the control of the same government as Earth. Humans native to the Moon are called "Lunies", and tend toward tall, lean body types regularly reaching eight feet in height. They are frequently referred to as looking much like Tolkien's Elves due to their physiques and alien allure. Mars, fourth planet in the Solar System and the first planetary colony in Known Space. Native "Martians" were exterminated by the Brennan genocide. No one goes there, as resources are easier to mine in the Belt and Jovian moons. Earth ultimately colonized Mars specifically to study the descent landing pod used by Phssthpok the Pak in 2124 AD and the research colony was still in existence in 2183 when the Martians were exterminated by Brennan. The colony expanded greatly during the first Man-Kzin war 2367-2433. The Sol Belt possesses an abundance of valuable ores, which are easily accessible due to the low to negligible gravity of the rocks containing them. Originally a harsh frontier under U.N. control, the Belt declared independence after creating Confinement Asteroid, a habitat with spin gravity that permitted safe gestation of children, and Farmer's Asteroid, the Belt's primary food source. Almost immediately a lively competition began between the fiercely independent "Belters" and the technology police of the U.N. Several years of tension and economic conflicts followed, but soon settled into a relatively peaceful trade relationship as the Belt has so many resources that the UN and the Earth need. Mercury is also a colony world with a small number of inhabitants, used mainly for mining and as a gravitational anchor for orbiting solar power stations which beam power to the more remote colonies using gigantic lasers. At the time of the First Man-Kzin War, human society is so pacifistic that no weapons exist; those who are able to even contemplate killing another sentient being or constructing a weapon for that purpose are regarded as mental aberrations and must take drugs to control their thoughts. However, an enormous laser, whether constructed as a weapon or not, makes a highly effective one, and it's strongly implied that the existence of the Mercury power satellites is a large part of what enabled Sol System to hold off the Kzinti in the early part of the war. Down is the home world of the Grogs and a former Kzinti colony. It orbits "L5-1668", a faint, cool M-type star, significantly redder and cooler than Sol and 12.3 light-years from it. Down is made habitable in part because of its large moon, Sheila. Grogs, though friendly, are feared by humanity, due to their telepathic ability to control the minds of animals (and possibly sentient species as well). Because of this fear, humans have placed a Bussard ramjet field generator in close orbit around Down's sun, thus enabling them to destroy the Grog population should they ever take hostile action against any sentient species. Jinx, orbiting Sirius A, is a massive moon of a gas giant (called Primary), stretched by tidal forces into an egg shape and tidally locked. In the habitable areas it has high surface gravity near the limits of human extended tolerance. The points nearest to and farthest from Primary (called the "East" and "West" ends) lie elevated out of the atmosphere in vacuum. The atmosphere of the belt-region halfway between them is too dense and too hot to breathe, and is inhabited only by the Bandersnatchi. The zones between the vacuum areas and the high-density belt area have atmosphere breathable by humans. Jinx's "East" and "West" ends become a major in vacuo manufacturing area. Jinxian humans are short and squat, the strongest bipeds in Known Space. But they tend to die early, from heart and circulatory problems. There is a tourist industry which provides substantial useful interplanetary trade credits for the Bandersnatchi, who allow themselves to be hunted by humans under strict protocols. Wunderland is a planet circling Alpha Centauri, and was the earliest extra-solar colony in Known Space's human history. It has a surface gravity of 60% that of Earth's and is hospitable to human life. Wunderland was invaded and its population enslaved by the Kzinti during the first Man-Kzin War. It was freed near the end of the First War by the human Hyperdrive Armada from We Made It. The system has an asteroid belt in the shape of a crescent, which gives it its name—the Serpent Swarm. The capital asteroid, Tiamat, houses one of the largest Kzin populations in Known Space. We Made It, orbiting Procyon A, got its name because the first colony ship crash-landed. Gravity is about three-fifths Earth's. The planet's axis is pointed along the plane of its ecliptic (like Uranus), creating ferocious winds on the order of 500 mph (800 km/h) during half of the planet's year, forcing the people to live underground. Natives are known as "Crashlanders", tend to be very tall, and many are albinos. Their capital, which was the site of their colony ship's landing, is called Crashlanding City. We Made It also has viscous, algae-choked "oceans" and a big icy moon, ironically named Desert Isle. Plateau in the Tau Ceti system is Venus-like, with a plateau (called Mount Lookitthat), half the size of California, rising high enough out of the dense atmosphere to be habitable. Inhabitants ("Mountaineers") are divided into two rigid hereditary castes, the "crew" and the "colonists", depending on whether their ancestors piloted the colonizing vessel. The crew are the upper caste, and hold power through their monopoly on organ transplantation and control of the police. The original colonists signed the "Covenant of Planetfall", agreeing that this outcome was just recompense for the labors of the crew during the voyage; that they signed at gunpoint as they were awakened from hibernation is kept secret from later generations, and also that those who refused, died. This repressive system is overthrown in A Gift From Earth, and the former inequality and caste system appears to have disappeared by the time The Ethics of Madness takes place. Home orbits the star Epsilon Indi, about 12 light years from Earth. The planet received its name because of its remarkable similarity to Earth; its day is nearly 24 hours long and its surface gravity is a comfortable 1.08 g. Oceans, mean global temperature, seasons, and moon (Home's moon is called Metaluna, but is often referred to as "the Moon" by Homers) are also similar. According to Protector, the original colonists had planned to call their world "Flatland" as a sort of joke, but once settled on Home they had changed their minds—"a belated attack of patriotism", Elroy Truesdale of Protector muses. The entire population of Home is secretly destroyed as a consequence of Brennan's and Truesdale's war with the Pak—Brennan turns the entire population into human Protectors to create an army to fight the Pak invaders. Home is resettled quickly though, since another ramjet with colonists is already on its way when the colony "fails". In Procrustes and other later stories, Home is once again presented as a vibrant colony. Canyon was once an uninhabitable Mars-like world known as Warhead. It is the second of seven planets around p Eridani A, 22 light-years from Earth. It was used as a military outpost by the Kzinti, until the planet was hit by a weapon called the "Wunderland Treatymaker" during the Third War. The attack tore a long, narrow, kilometers-deep crater into the crust approximately the size of the Baja Peninsula. The air and moisture in the thin atmosphere gathered at the bottom of this artificial canyon, creating a breathable environment, complete with a sea at the bottom. The planet was then renamed for the crater, and settled by humans in a huge city running up the crater wall. Archaic (hyper-aggressive and intractable) Kzinti were entombed in stasis field shells during the attack and are still beneath the lava, and someday, somebody will have to deal with them. The attack by the Wunderland Treatymaker is detailed as a part of Destiny's Forge by Paul Chafe, a part of the Man-Kzin Wars shared universe. Gummidgy is a jungle world popular with hunters. It is home to the Gummidgy Orchid-Thing, a sessile carnivore which hangs from trees and is a popular trophy for the wealthy. It orbits CY Aquarii, a blue giant SX Phoenicis variable star; due to the resulting high levels of ultraviolet light, most humans (except Jinxians) require melanin-boosting medication to venture outdoors. Fafnir is a former Kzin colony covered almost entirely in water. When under Kzinti control it was called Shasht, a Kzin word meaning "burrowing murder." It was captured by humans during the Man-Kzin Wars. Humans and Kzinti now cohabitate. The humans prefer to live on the coral islands while the Kzinti prefer the single large continent which they continue to call Shasht. Margrave is a late addition to the family of Human colonies. In the Ringworld era it is still a frontier world, and is home to enormous birds the inhabitants have dubbed "rocs". It orbits Lambda Serpentis (27 Serpentis), a G0 star 34.7 light-years from Earth. It is named after its discoverer, J. Margrave Julland. Silvereyes is, at the time of Ringworld, the furthest Human world from Earth (21.3 light-years, 60 days at Quantum-I hyperdrive speeds), orbiting Beta Hydri. In Niven's obscure story The Color of Sunfire it has entire continents covered with Slaver sunflowers (bred as defense for Thrint manors, they focus sunlight using silver leaves as parabolic reflectors), giving it an appearance from orbit of having "silver eyes". The Man-Kzin Wars books, conversely, have it entirely covered by a world ocean, with groves of sunflowers growing up from the bottom of the ocean. The Ringworld Roleplaying Game describes it as an ocean planet dotted with island shield volcanoes. The Fleet of Worlds is the five (at one point six, as detailed in Fleet of Worlds) planets that are home to the Puppeteers (see above), presently being moved in formation at sub-light speeds out of the galaxy to avoid destruction as the wave of radiation from an explosion of the galactic core sweeps towards the outer reaches of the galaxy. They orbit about each other in a Klemperer rosette. Hearth is the homeworld of the Pierson's Puppeteers, with a population of around one trillion and is covered by arcologies, most over one mile tall. Its industries and population generate so much waste heat it no longer requires a star for warmth (the four other "farmworlds", simply named "Nature Preserves" or NP1, NP2, etc., use artificial orbital lights to grow food). Together they are often referred as "the fleet of Worlds" and do not orbit any star, but use Outsider manufactured drives to move in order to flee the galactic core explosion discovered by Beowulf Schaffer. Kobold was a tiny artificial world created in the outer Sol System by Jack Brennan, a human Protector, composed of a small sphere of neutronium in the center ringed by a larger torus. Gravity generators facilitated movement between the two sections and were used in games and art. Brennan destroyed Kobold just prior to leaving for his war with the Pak Protectors. The Ringworld is an artificial world structure with three million times the surface area of Earth, built in the shape of a giant ring circling its sun, a million miles wide and with a diameter of 186 million miles. It was built by the Pak, who either abandoned it, or more likely died out much as the Earth Pak did, due to a lack of a key yamlike root which produces the conversion to Protector-stage Pak (which required a very specifically targeted soil chemistry to grow). It is inhabited by a number of different evolved hominid species, and includes representative samples of Bandersnatchi, Martians and Kzinti, and possibly other alien races that existed at the time of its construction. Sheathclaws is a planet colonized by humans aboard Angel's Pencil and descendants of a rogue Kzin telepath. It orbits an as-yet-unspecified star 98 light-years from Earth, and kept its existence secret for several centuries. The Patriarchy would dearly love to capture the entire population of potential Telepaths and press them into service. "Kzin" translates as "Home-of-the-Kzinti" or "Kzinhome" in the Hero's Tongue. It orbits 61 Ursae Majoris and has higher gravity than Earth and more oxygen in the atmosphere. It has two moons, known as the Hunter's Moon and the Traveler's Moon. Cue Ball is an uninhabitable ice world orbiting Beta Lyrae. Jm'ho A moon similar to Europa, homeword to the Gw'oth. It orbits a gas giant called Tl'ho. The star is simply called G567-X2 in the Puppeteers' catalogue Kl'mo A Gw'oth colony founded by Ol't'ro. Not much is explained about this world, except that it seems very primitive and has a very strong gravity. Oceanus A primitive world briefly surveyed by the crew of "Explorer" in the first "Fleet of worlds" book. Technology The series features a number of "superscience" inventions which figure as plot devices. Stories earlier in the timeline feature technology such as Bussard ramjets, Drouds (wires capable of directly stimulating the pleasure centers of the brain) and explore how organ transplantation technology enables the new crime of organlegging (as well as the general sociological effects of widespread transplant technology), while later stories feature hyperdrive, invulnerable starship hulls, stasis fields, molecular monofilaments, transfer booths (teleporters used only on planetary surfaces), the lifespan-extending drug boosterspice, and the tasp which is an extension of the wirehead development which works without direct contact. Boosterspice Boosterspice is a compound that increases the longevity and reverses aging of human beings. With the use of boosterspice, humans can easily live hundreds of years and, theoretically, indefinitely. Developed by the Institute of Knowledge on Jinx, it is said to be made from genetically engineered ragweed (although early stories have it ingested in the form of edible seeds). In Ringworld's Children, it is suggested boosterspice may actually be adapted from Tree-of-Life, without the symbiotic virus that enabled hominids to metamorphose from Pak Breeder stage to Pak Protector stage (mutated Pak breeders were the ancestors of both Homo sapiens and the hominids of the Ringworld). On the Ringworld, there is an analogous (and apparently more potent) compound developed from Tree-of-Life, but they are mutually incompatible; in The Ringworld Engineers, Louis Wu learns that the character Halrloprillalar died when in ARM custody after leaving the Ringworld, as a result of having taken boosterspice after having used the Ringworld equivalent. Boosterspice only works on Homo sapiens, whereas the Tree-of-Life compound will work on any hominid descended from the Pak. Hyperdrive Faster-than-light (FTL) propulsion, or hyperdrive, was obtained from the Outsiders at the end of the First Man-Kzin War. In addition to winning the war for humanity, it allowed the re-integration of all the human colonies, which were previously separated by distance. Standard hyperdrive covers a distance of one light-year every three days (121.75 x c). A more advanced Quantum II Hyperdrive introduced later is able to cover the same distance in one and a quarter minutes (420,768 x c). In Niven's first novel, World of Ptavvs, the hyperdrive used by the Thrintun required a ship to be going faster than 93% of the speed of light. However, this is the only time that Hyperdrive is described this way. In the vast majority of Known Space material, hyperdrive requires that a ship be outside a star's gravity well to use. Ships which activate hyperdrive close to a star are likely to disappear without a trace. This effect is regarded as a limitation based on the laws of physics. In Niven's novel Ringworld's Children the Ringworld itself is converted into a gigantic Quantum II hyperdrive and launched into hyperspace while within its star's gravity well. Ringworld's Children reveals that there is life in hyperspace around gravity wells and that hyperspace predators eat spaceships which appear in hyperspace close to large masses, thus explaining why a structure as large as the Ringworld can safely engage the hyperdrive in a star's gravity well. One phenomenon travellers in hyperspace can experience is the so-called 'blind spot' should they look through a porthole or camera screen, giving the impression that the walls around the porthole or sides of the camera view screen are expanding to 'cover up the outside'. The phenomenon is the result of hyperspace being so fundamentally different from 'normal/Einstein' space that a traveller's senses can not truly comprehend it, and instead the observer 'sees' a form of nothingness that can be hypnotic and dangerous. Staring too long into the 'blind' spot can be insanity inducing, so as a precaution all view ports on ships are blinded when a ship enters hyperspace. Invulnerable hulls The Puppeteer firm, General Products, produces an invulnerable starship hull, known simply as a General Products Hull. The hulls are impervious to any type of matter or energy, with the exception of antimatter (which destroys the hull), gravitation, and visible light (which passes through the hull). While invulnerable themselves, this is no guarantee that the contents are likewise protected. For example, though a high speed impact with the surface of a planet or star may cause no harm to the hull, the occupants will be crushed if they are not protected by additional measures such as a stasis field or a gravity compensating field. In Fleet of Worlds, the characters tour a General Products factory and receive clues that allow them to destroy a General Products hull from the inside using only a high-powered interstellar communications laser. In Juggler of Worlds, the Puppeteers, attempting to surmise how this was done without antimatter, identify another technique which can be used to destroy the otherwise invulnerable hulls, one which does suggest some potential defense options. Organ transplantation On Earth in the mid-21st century, it became possible to transplant any organ from any person to another, with the exception of brain and central nervous system tissue. Individuals were categorized according to their so-called "rejection spectrum" which allowed doctors to counter any immune system responses to the new organs, allowing transplants to "take" for life. It also enabled the crime of "organlegging" which lasted well into the 24th century. Stasis fields A Slaver stasis field creates a bubble of space/time disconnected from the entropy gradient of the rest of the universe. Time slows effectively to a stop for an object in stasis, at a ratio of some billions of years outside to a second inside. An object in stasis is invulnerable to anything occurring outside the field, as well as being preserved indefinitely. A stasis field may be recognized by its perfectly reflecting surface, so perfect that it reflects 100% of all radiation and particles, including neutrinos. However one stasis field cannot exist inside another. This is used in World of Ptavvs where humans develop a stasis field technology and realize that a mirrored artifact known as the Sea Statue must be actually an alien in a stasis field. They place it with a human envoy, who is a telepath, and envelop both in field. By doing this, they unleash the last living member of the Slaver species on the world. Stepping disks Stepping disks are a fictional teleportation technology. They were invented by the Pierson's Puppeteers, and their existence is not generally known to other races until the events of The Ringworld Engineers. The stepping disks are an outgrowth and improvement of the transfer booth technology used by humans and other Known Space races. Unlike the booths, the disks do not require an enclosed chamber, and somehow can differentiate between solid masses and air, for example. They also have a far greater range than transfer booths, extending several astronomical units. Several limitations to stepping disks are mentioned in the Ringworld novels. If there is a difference in velocity between two disks, any matter transferred between them must be accelerated by the disk accordingly. If there is not enough energy to do so, the transfer cannot take place. This becomes a problem with disks that are a significant distance apart on the Ringworld surface, as they will have different velocities: same speed, different direction. Transfer booths Transfer booths or displacement booths are an inexpensive form of teleportation. Short-range booths are similar in appearance to an old style telephone booth: one enters, "dials" one's desired destination, and is immediately deposited in a corresponding booth at the destination. Longer-range booths operate similarly, but are housed in former airports due to requiring "equipment to compensate for the difference in rotational velocity between different points on the Earth". They are inexpensive: a trip anywhere on Earth costs only a "tenth-star" (presumably equivalent to a dime). Introduced by one of Gregory Pelton's ancestors, apparently bought from, and based on, Puppeteer technology. "A displacement booth was a glass cylinder with a rounded top. The machinery that made the magic work was invisible, buried beneath the booth. Coin slots and a telephone dial were set into the glass at sternum level" (from Flash Crowd) Paranormal abilities Some individuals in the stories display limited paranormal or "psionic" abilities. Gil Hamilton can move objects with his mind using his phantom arm, which he gained after losing an arm in an asteroid mining accident. When he finally had the arm replaced from an organ bank on Earth, the ability persisted. "Plateau Eyes" (introduced in A Gift From Earth) is an ability to hide in plain sight, by causing others not to notice you. Population control is tight on Earth, but these abilities can gain the possessor a license to have more children. The Pierson's Puppeteers engineer a lottery for child licenses on Earth to increase the occurrence of Luck, which they think is a paranormal ability humans have that has enabled them to defeat races such as the Kzinti. In Ringworld, the character Teela Brown is said to have this ability (although possibly not to the same extent as others who avoided being included in the expedition). Organizations ARM The ARM is the police force of the United Nations. ARM originated as an acronym for "Amalgamation of Regional Militia", though this is not a term in current usage by the time of the Known Space novels. An agent of the ARM, Gil Hamilton, is the protagonist of Niven's science fictional detective stories, a series-within-a-series gathered in the collection Flatlander. (Confusingly, "Flatlander" is also the name of an unrelated Known Space story.) Their basic function is to enforce mandatory birth control on overcrowded Earth, and restrict research which might lead to dangerous weapons. In short, the ARM hunts down women who have illegal pregnancies and suppresses all new technologies. They also hunt organleggers, especially in the era of the "organ bank problem". Among the many technologies they control and outlaw are all trained forms of armed and unarmed combat. By the 25th century, ARM agents were kept in an artificially induced state of paranoid schizophrenia to enhance their usefulness as law enforcement officials, which led to them sometimes being referred to as "Schizes". Agents with natural tendencies toward paranoia were medicated into docility during their off duty hours, through the aforementioned science of psychistry (see Madness Has Its Place and Juggler of Worlds). Their jurisdiction is limited to the Earth-Moon system; other human colonies have their own militia. Nevertheless, in many Known Space stories, ARM agents operate or exert influence in other human star systems through the "Bureau of Alien Affairs" (see In the Hall of the Mountain King, Procrustes, The Borderland of Sol, and "Neutron Star"). These interventions begin following the Man-Kzin Wars and the introduction of hyperdrive, presumably as part of a general re-integration of human societies. Stories in Known Space The Tales of Known Space were first published primarily as short stories or serials in science fiction magazines. Generally the short fiction was subsequently released in one or more collections and the serial novels as books. Some of the shorter novels (novellas) published in magazines were expanded as, or incorporated in, book-length novels. There are also two or three short stories which share common themes and some background elements with Known Space stories, but which are not considered a part of the Known Space universe: One Face (1965) and Bordered in Black (1966) —both in the 1979 collection Convergent Series—and possibly The Color of Sunfire, published online and listed here. In the Known Space stories, Niven had created a number of technological devices (GP hull, stasis field, Ringworld material) which, combined with the "Teela Brown gene", made it very difficult to construct engaging stories beyond a certain date—the combination of factors made it tricky to produce any kind of creditable threat/problem without complex contrivances. Niven demonstrated this, to his own satisfaction, with Safe at Any Speed (1967). He used the setting for much less short fiction after 1968 and much less for novels after two published in 1980. Late in that decade, Niven invited other authors to participate in a series of shared-universe novels, with the Man-Kzin Wars as their setting. The first volume was published in 1988. {\| class="wikitable sortable" \|+ Stories written by Larry Niven in the Tales of Known Space series !Title\|\|Published\|\|First appearance\|\|Collection \|- \|"The Coldest Place"\|\|1964 (December) \|\|Worlds of If\|\|Tales of Known Space \|- \|"World of Ptavvs" \|\|1965\|\|Worlds of Tomorrow\|\| Three Books of Known Space \|- \|"Becalmed in Hell"\|\|1965 \|The Magazine of Fantasy and Science Fiction \|Tales of Known Space, All the Myriad Ways, Playgrounds of the Mind \|- \|World of Ptavvs \|\|1966 \|\|(novel)\|\| Three Books of Known Space \|- \|"Eye of an Octopus"\|\|1966\|\|Galaxy Magazine\|\|Tales of Known Space \|- \|"The Warriors"\|\|1966\|\|Worlds of If\|\|Tales of Known Space, Man-Kzin Wars I\|- \|"Neutron Star"\|\|1966\|\|Worlds of If\|\|Neutron Star Crashlander\|- \|"How the Heroes Die"\|\|1966\|\|Galaxy Magazine\|\|Tales of Known Space\|- \|"At the Core"\|\|1966\|\|Worlds of If\|\|Neutron Star, Crashlander\|- \|"A Relic of the Empire"\|\|1966\|\|Worlds of If\|\|Neutron Star, Playgrounds of the Mind\|- \|"At the Bottom of a Hole"\|\|1966\|\|Galaxy Magazine\|\|Tales of Known Space\|- \|"The Soft Weapon"\|\|1967\|\|Worlds of If\|\|Neutron Star, Playgrounds of the Mind\|- \|"Flatlander"\|\|1967\|\|Worlds of If\|\|Neutron Star, Crashlander\|- \|"The Ethics of Madness"\|\|1967\|\|Worlds of If\|\|Neutron Star\|- \|"Safe at any Speed"\|\|1967\|\|The Magazine of Fantasy and Science Fiction\|\|Tales of Known Space\|- \|"The Adults" \|\|1967\|\|Galaxy Magazine\|\| Protector\|- \|"The Handicapped"\|\|1967\|\|Galaxy Magazine\|\|Neutron Star\|- \|"The Jigsaw Man"\|\|1967\|\|Dangerous Visions\|\|Tales of Known Space\|- \|"Slowboat Cargo" \|\|1968\|\|Worlds of If\|\|A Gift From Earth\|- \|"The Deceivers" (later titled "Intent to Deceive") \|\|1968\|\|Galaxy Magazine\|\|Tales of Known Space\|- \|"Grendel"\|\|1968\|\|(collection only)\|\|Neutron Star, Crashlander\|- \|"There is a Tide"\|\|1968\|\|Galaxy Magazine\|\|Tales of Known Space, A Hole in Space\|- \|A Gift From Earth \|\|1968\|\|(novel)\|\| Three Books of Known Space\|- \|"Wait It Out"\|\|1968\|\|Future Unbounded convention program\|\|Tales of Known Space\|- \|"The Organleggers" (later titled "Death by Ecstasy") \|\|1969 (January) \|\|Galaxy Magazine\|\|The Shape of Space, The Long ARM of Gil Hamilton, Flatlander\|- \|Ringworld\|\|1970\|\|(novel)\|\| — \|- \|"Cloak of Anarchy"\|\|1972\|\|Analog Science Fiction\|\|Tales of Known Space, N-Space\|- \|Protector \|\|1973\|\|(novel)\|\| — \|- \|"The Defenseless Dead"\|\|1973\|\|Ten Tomorrows\|\|Flatlander, The Long ARM of Gil Hamilton, Playgrounds of the Mind\|- \|"The Borderland of Sol"\|\|1975\|\|Analog Science Fiction\|\|Tales of Known Space, Crashlander, Playgrounds of the Mind\|- \|"ARM"\|\|1975\|\|Epoch\|\|The Long ARM of Gil Hamilton\|- \|The Ringworld Engineers\|\|1979\|\|(novel)\|\| — \|- \|The Patchwork Girl\|\|1980\|\|(novel)\|\| Flatlander\|- \|"Madness Has Its Place"\|\|1990\|\|Isaac Asimov's Science Fiction Magazine\|\|Man-Kzin Wars III, Three Books of Known Space\|- \|Inconstant Star \|1991 \|(fix-up novel) \|The Man-Kzin Wars (Part One), Man-Kzin Wars III (Part Two) \|- \|"The Color Of Sunfire"\|\|1993\|\|Worldcon 51 convention program ("Bridging the Galaxies")\|\| Bridging the Galaxies\|- \|"Procrustes"\|\|1993\|\|Worldcon 51 convention program ("Bridging the Galaxies")\|\|Crashlander\|- \|"Ghost"\|\|1994\|\| (collection only, as frame story) \|\|Crashlander\|- \|"The Woman in Del Rey Crater"\|\|1995\|\|(collection only)\|\|Flatlander\|- \|The Ringworld Throne\|\|1996\|\|(novel)\|\| — \|- \|"Choosing Names"\|\|1998\|\|(collection only)\|\|Choosing Names: Man-Kzin Wars VIII\|- \|"Fly-By-Night"\|\|2000\|\|Asimov's Science Fiction\|\|Man-Kzin Wars IX\|- \|Ringworld's Children\|\|2004\|\|(novel)\|\| — \|- \|"The Hunting Park"\|\|2005\|\|(collection only)\|\|Man-Kzin Wars XI\|- \|Fleet of Worlds (Edward M. Lerner and Niven, coauthors) \|\|2007 \|\|(novel)\|\| — \|- \|Juggler of Worlds (Lerner and Niven) \|\|2008\|\|(novel)\|\| — \|- \|Destroyer of Worlds (Lerner and Niven) \|\|2009\|\|(novel)\|\| — \|- \|Betrayer of Worlds (Lerner and Niven) \|\|2010\|\|(novel)\|\| — \|- \|Fate of Worlds (Lerner and Niven) \|\|2012\|\|(novel)\|\| — \|}Ringworld (1970) won the annual Nebula, Hugo, and Locus best novel awards.Protector (1973) and The Ringworld Engineers (1980) were nominated for the Hugo and Locus Awards. Man-Kzin Wars Playground Niven has described his fiction as "playground equipment", encouraging fans to speculate and extrapolate on the events described. Debates have been made, for example, on who built the Ringworld (Pak Protectors and the Outsiders being the traditional favorites, but see Ringworld's Children for a possibly definitive answer), and what happened to the Tnuctipun. Niven also states that this is not an invitation to violate his copyrights, warning potential publishers and editors not to proceed without permission. Niven was also reported to have said that "Known Space should be seen as a possible future history told by people that may or may not have all their facts right." The author also published an "outline" for a story which would "destroy" the Known Space Series (or more precisely, reveal much of the Known Space background to be an in-universe hoax), in an article entitled "Down in Flames". Although the article is written as though Niven intended to write the story, he later wrote that the article was only an elaborate joke, and he never intended to write such a novel. The article itself notes that the outline was made obsolete by the publication of Ringworld. "Down in Flames" was a result of a conversation between Norman Spinrad and Niven in 1968, but at the time of its first publication in 1977 some of the concepts were invalidated by Niven's writings between '68 and '77. (A further edited version of the outline was published in N-Space in 1990.) References Citations Wayne Douglas Barlowe, Barlowe's Guide to Extraterrestrials: Great Aliens from Science Fiction Literature'', Workman Pub Co, 1979. External links Known Space: The Future Worlds of Larry Niven (official) Encyclopedia of Known Space The Known Space Concordance Timeline of the Known Space universe Marc Carlson's Timeline of the Known Space universe Website for the Man-Kzin Wars novel Destiny's Forge Homepage of MKW author Paul Chafe Book series introduced in 1964 Fictional universes Novels by Larry Niven Science fiction book series Fiction about trans-Neptunian objects Fiction about asteroid mining Genetic engineering in fiction Extraterrestrial life in popular culture Organ transplantation in fiction Novels about drugs Hive minds in fiction Fiction about telepathy Computing in fiction Faster-than-light travel in fiction Novels about slavery Fiction set on Mars Fiction about mind control Fiction set on the Moon Fiction about dolphins KnownSpace	[ -0.04256706312298775, 0.5379607081413269, -0.7922738790512085, 0.27277079224586487, 0.05290525406599045, 0.008517018519341946, -0.29823896288871765, 0.7820470929145813, -0.059295762330293655, -0.2058393955230713, -0.47188708186149597, -0.0005268980748951435, -0.26065340638160706, 0.8487874...
18225	https://en.wikipedia.org/wiki/LeRoy%20Homer%20Jr.	LeRoy Homer Jr.	LeRoy Wilton Homer Jr. (August 27, 1965 – September 11, 2001) was the First Officer of United Airlines Flight 93, which was hijacked as part of the September 11 attacks in 2001, and crashed into a field near Shanksville, Pennsylvania, killing all 37 passengers and seven crewmembers, including LeRoy. Biography Homer, son of a West German woman and an American soldier who was stationed in West Germany, grew up on Long Island in New York, where he always dreamed of flying. As a child, he assembled model airplanes, collected aviation memorabilia and read books on aviation. He was 15 years old when he started flight instruction in a Cessna 152. Working part-time jobs after school to pay for flying lessons, he completed his first solo trip at the age of 16 and obtained his private pilot's certificate in 1983. Homer was graduated from Ss. Cyril and Methodius School in 1979 and St. John the Baptist Diocesan High School in 1983. He entered the United States Air Force Academy as a member of the class of 1987. As an upperclassman, he was a member of Cadet Squadron 31. He graduated on May 27, 1987, and was commissioned as a second lieutenant in the U.S. Air Force. After completing his USAF pilot training in 1988, he was assigned to McGuire Air Force Base in New Jersey, flying a Lockheed C-141 Starlifter. While on active duty, he served in the Gulf War and later supported operations in Somalia. He received many commendations, awards and medals during his military career. In 1993, he was named the Twenty-First Air Force "Aircrew Instructor of the Year". Homer achieved the rank of captain before his honorable discharge from active duty in 1995 and his acceptance of a reserve commission in order to continue his career as an Air Force officer. Homer continued his military career as a member of the U.S. Air Force Reserve, initially as a C-141 instructor pilot with the 356th Airlift Squadron at Wright-Patterson Air Force Base in Ohio, then subsequently as an Academy Liaison Officer, recruiting potential candidates for both the Air Force Academy and the Air Force Reserve Officer Training Corps. During his time in the Air Force Reserve, he achieved the rank of major. He continued his flying career by joining United Airlines in May 1995. His first assignment was Second Officer on the Boeing 727. He then upgraded to First Officer on the Boeing 757/Boeing 767 in 1996, where he remained until September 11, 2001. He married his wife, Melodie, on May 24, 1998, and his first child, Laurel, was born in late November 2000. They resided together in Marlton, New Jersey. September 11 attacks On September 11, 2001, Homer was flying with Captain Jason M. Dahl on United Airlines Flight 93 from Newark, New Jersey, to San Francisco. The plane was hijacked by four al-Qaeda terrorists as part of the September 11 attacks. Homer and Dahl struggled with the hijackers, which was transmitted to Air Traffic Control. After learning of the earlier crashes at the World Trade Center and the Pentagon, the crew and passengers attempted to foil the hijacking and reclaim the aircraft. Given the uprising of crew and passengers, and knowing they would not make it to their intended target, which was the US Capitol, the hijackers instead chose to crash the plane into a field near Shanksville, Pennsylvania. Homer received many awards and citations posthumously, including honorary membership in the historic Tuskegee Airmen; the Congress of Racial Equality's Dr. Martin Luther King Jr. Award; the Southern Christian Leadership Conference Drum Major for Justice Award; and the Westchester County Trailblazer Award. He was survived by his wife, Melodie, and his only child, daughter Laurel. Other family members include his mother, seven sisters, and his brother. His widow Melodie Homer established the LeRoy W. Homer Jr. Foundation, which awards scholarships related to aviation. At the National 9/11 Memorial, Homer Jr. is memorialized at the South Pool, on Panel S-67, along with other crew and passengers on Flight 93. References Further reading Melodie Homer, From Where I Stand: Flight #93 Pilot's Widow Sets the Record Straight () External links "United Pilot Was a Proud Papa, Helped Others", Newsday. "Huge crowd remembers LeRoy Homer Jr.", phillyBurbs.com. LeRoy Homer Foundation 1965 births 2001 deaths People from Evesham Township, New Jersey People from Long Island United States Air Force Academy alumni United Airlines Flight 93 victims American terrorism victims Murdered African-American people People murdered in Pennsylvania Terrorism deaths in Pennsylvania American people of German descent Commercial aviators Aviators killed in aviation accidents or incidents in the United States St. John the Baptist Diocesan High School alumni 21st-century African-American politicians Victims of the September 11 attacks Military personnel from New Jersey	[ -0.5814557671546936, 0.7525594830513, -0.7873943448066711, -0.4214828610420227, -0.01605575904250145, 0.20913800597190857, 0.49140653014183044, 0.19714784622192383, -0.5801430344581604, -0.23746256530284882, -0.21297264099121094, 0.513523519039154, -0.2793988883495331, 0.5170552134513855, ...
18227	https://en.wikipedia.org/wiki/LGB	LGB	LGB may refer to: Places La Grande Boissière, a campus of the International School of Geneva Long Beach Airport (IATA code), California, US Other uses The Larger Grain Borer (LGB), Prostephanus truncatus Laser-guided bomb Lectures on Government and Binding, a book by Noam Chomsky "Lesbian, gay, and bisexual", later usually LGBT "Let's Go Brandon", a political slogan used since 2021 LGB (trains) (Lehmann Gross Bahn), garden railroads LGB Alliance	[ 0.6216228604316711, 0.16392238438129425, 0.11962882429361343, -0.18640601634979248, -0.030347025021910667, 0.15602894127368927, -0.02864127978682518, 0.4942821264266968, -0.22229814529418945, -0.16015461087226868, -0.7618156671524048, -0.003637429093942046, -0.48720136284828186, 0.11795479...
10237729	https://en.wikipedia.org/wiki/Azizi%20Bank	Azizi Bank	Azizi Bank is one of the largest commercial banks in Afghanistan, having more than 80 branches including extension counters and 101 ATMs in Kabul and throughout the country. The bank opened on June 13, 2006, and is headquartered in Zanbaq Square, Kabul, Afghanistan. The banks caters to a wide gamut of products and services ranging from variety of accounts, attractive rates for fixed deposits, international debit and credit cards, international money transfer services, treasury and forex services, mobile wallet and trade finance facilities. References "Capitalism Comes to Afghanistan". Time. (December 4, 2006). "Life's a lottery in the new Afghanistan". Sydney Morning Herald. (September 18, 2006). External links Banks of Afghanistan Banks established in 2005	[ 0.33698827028274536, -0.19036522507667542, -0.40434470772743225, -0.4216639995574951, -0.03098204918205738, 0.7307993173599243, 0.4167225956916809, 0.4289077818393707, -0.10635165125131607, 0.04404548555612564, -0.24877972900867462, -0.28183427453041077, -0.6792768836021423, 0.300919324159...
18230	https://en.wikipedia.org/wiki/La%20Jet%C3%A9e	La Jetée	La Jetée () is a 1962 French science fiction featurette directed by Chris Marker and associated with the Left Bank artistic movement. Constructed almost entirely from still photos, it tells the story of a post-nuclear war experiment in time travel. It is 28 minutes long and shot in black and white. It won the Prix Jean Vigo for short film. The 1995 science fiction film 12 Monkeys was inspired by and borrows several concepts directly from La Jetée. Plot A man (Davos Hanich) is a prisoner in the aftermath of World War III in post-apocalyptic Paris, where survivors live underground in the Palais de Chaillot galleries. Scientists research time travel, hoping to send test subjects to different time periods "to call past and future to the rescue of the present." They have difficulty finding subjects who can mentally withstand the shock of time travel. The scientists eventually settle upon the protagonist; his key to the past is a vague but obsessive memory from his pre-war childhood of a woman (Hélène Châtelain) he had seen on the observation platform ("the jetty") at Orly Airport shortly before witnessing a startling incident there. He did not understand exactly what happened, but knew he had seen a man die. After several attempts, he reaches the pre-war period. He meets the woman from his memory, and they develop a romantic relationship. After his successful passages to the past, the experimenters attempt to send him into the far future. In a brief meeting with the technologically advanced people of the future, he is given a power unit sufficient to regenerate his own destroyed society. Upon his return, with his mission accomplished, he discerns that he is to be executed by his jailers. He is contacted by the people of the future, who offer to help him escape to their time permanently; but he asks instead to be returned to the pre-war time of his childhood, hoping to find the woman again. He is returned to the past, placed on the jetty at the airport, and it occurs to him that the child version of himself is probably also there at the same time. He is more concerned with locating the woman, and quickly spots her. However, as he rushes to her, he notices an agent of his jailers who has followed him and realizes the agent is about to kill him. In his final moments, he comes to understand that the incident he witnessed as a child, which has haunted him ever since, was his own death. Cast Jean Négroni as Narrator Hélène Châtelain as The Woman Davos Hanich as The Man Jacques Ledoux as The Experimenter Ligia Branice as Woman From The Future Janine Kleina as Woman From The Future William Klein as Man From The Future Production La Jetée is constructed almost entirely from optically printed photographs playing out as a photomontage of varying rhythm. It contains only one brief shot (of the woman mentioned above sleeping and suddenly waking up) originating on a motion-picture camera, this due to the fact that Marker could only afford to hire one for an afternoon. The stills were taken with a Pentax Spotmatic and the motion-picture segment was shot with a 35 mm Arriflex. The film has no dialogue aside from small sections of muttering in German and people talking in an airport terminal. The story is told by a voice-over narrator. The scene in which the hero and the woman look at a cut-away trunk of a tree is a reference to Alfred Hitchcock's 1958 film Vertigo which Marker also references in his 1983 film Sans soleil. The editing of La Jetée adds to the intensity of the film. With the use of cut-ins and fade-outs, it produces the eerie and unsettling nature adding to the theme of the apocalyptic destruction of World War III. Terry Gilliam, director of 12 Monkeys, describes the editing as "simply poetic" in the combination of editing and soundtrack that is used in the short film. As the film plays out as a photomontage, the only continuous variable is the sound. The sound used in this production is minimal, showing up in the form of narration, Orchestral score and sound effect. The rhythmic patterns of the soundtrack act as a framework to add to the intensity of the film. "The dissolve is synchronized with the sound. As the story moves from the past to the present, La Jetee creates mental continuity." The soundtrack adds to the illusion of movement within the film and the change of time. Interpretation In Black and Blue, her study of postwar French fiction, Carol Mavor describes La Jetée as "taking place in a no-place (u-topia) in no-time (u-chronia)" which she connects to the time and place of the fairy tale. She further elaborates: "even the sound of the title resonates with the fairy-tale surprise of finding oneself in another world: La Jetée evokes 'là j'étais' (there I was)". By "u-topia", Mavor does not refer to "utopia" as the word is commonly used; she also describes an ambiguity of dystopia/utopia in the film: "It is dystopia with the hope of utopia, or is it utopia cut by the threat of dystopia." Tor Books blogger Jake Hinkson summed up his interpretation in the title of an essay about the film, "There's No Escape Out of Time". He elaborated: Hinkson also addresses the symbolic use of imagery: "The Man is blindfolded with some kind of padded device and he sees images. The Man is chosen for this assignment because ... he has maintained a sharp mind because of his attachment to certain images. Thus a film told through the use of still photos becomes about looking at images." He further observes that Marker himself did not refer to La Jetée as a film, but as photo novel. Yannis Karpouzis makes a structuralistic analysis on La Jetée, examining it as an intermedial artwork: Chris Marker creates an "archive" of objects and conditions that have a photographic quality of their own and they are followed by the same predicates as pictures. The dialogue between the media (photography and cinematography) and the filmic signifier (film stills, storyline and narration) is constantly in the backdrop. Reception In 2010, Time ranked La Jetée first in its list of "Top 10 time-travel movies". In 2012, in correspondence with the Sight & Sound Poll, the British Film Institute deemed La Jetée as the 50th greatest film of all time. In 1963, Prix Jean Vigo awarded La Jetée for "Best Short Film." In 1963, La Jetée was part of the Locarno International Film Festival. In 2009, the film was featured in "Buenos Aires Festival Internacional de Cine Independiente. La Jetée was featured in the "Cine//B Film Festival" in 2011. The International Documentary Film Festival Amsterdam had La Jetée as a featured film in 2019. Science fiction writer William Gibson considers the film one of his main influences. Legacy The video for Sigue Sigue Sputnik's 1989 single "Dancerama" is also an homage to La Jetée. The film is one of the influences in the video for David Bowie's "Jump They Say" (1993). Terry Gilliam's 12 Monkeys (1995) was inspired by and takes several concepts directly from La Jetée (acknowledging this debt in the opening credits). The 2003 short film La puppé is both an homage to and a parody of La Jetée. The 2007 Mexican film Year of the Nail, which is told entirely through still photographs, was inspired by La Jetée. The 2018 Spanish film Entre Oscuros Sueños, where is used the still-image movie concept, was entirely inspired by La Jetée. Kode9 in collaboration with Ms. Haptic, Marcel Weber (aka MFO), and Lucy Benson created an homage to La Jetée in 2011, for the Unsound Festival. Northern Irish rock band Two Door Cinema Club screened the film at the launch party for their 2016 album Gameshow. The final track on the album, "Je viens de la", is inspired by La Jetée and describes the journey of the film's protagonist. The film was included in the "1001 Movies You Must See Before You Die" by producer Steven Schneider. Friend of the World, a two-hander film, was inspired by La Jetée among others. Related media In 1992, Zone Books released a book which reproduced the film's original images along with the script in both English and French. Home media release In Region 2, the film is available with English subtitles in the La Jetée/Sans soleil digipack released by Arte Video. In Region 1, the Criterion Collection has released a La Jetée/Sans soleil combination DVD / Blu-ray, which features the option of hearing the English or French narration. See also Filmstrip List of films featuring time loops The Glass Fortress (similar photomontage style) References External links La Jetée analysis of themes and storyline by Simon Sellars Platonic Themes in Chris Marker's La Jetée by Sander Lee at Senses of Cinema La Jetée: Unchained Melody, an essay by Jonathan Romney at the Criterion Collection 1960s dystopian films 1960s science fiction films 1962 films Dystopian films Existentialist works Films about time travel Films directed by Chris Marker Films produced by Anatole Dauman Films set in Paris French films French post-apocalyptic films French science fiction films French short films Metaphysical fiction films Science fiction short films Time loop films	[ -0.29760369658470154, 0.30418580770492554, -0.3502514660358429, 0.3531029224395752, 0.11107314378023148, -0.19279184937477112, 0.33396726846694946, 0.12418564409017563, -0.11044179648160934, 0.3877151310443878, -0.07732315361499786, 0.5908824801445007, -0.3592933416366577, 0.49082320928573...
18232	https://en.wikipedia.org/wiki/Little%20penguin	Little penguin	The little penguin (Eudyptula minor) is the smallest species of penguin. It grows to an average of in height and in length, though specific measurements vary by subspecies. It is found on the coastlines of southern Australia and New Zealand, with possible records from Chile. In Australia, they are often called fairy penguins because of their small size. In New Zealand, they are more commonly known by their Māori name as kororā (singular and plural), or in English as little blue penguins or blue penguins owing to their slate-blue plumage. Taxonomy The little penguin was first described by German naturalist Johann Reinhold Forster in 1781. Several subspecies are known, but a precise classification of these is still a matter of dispute. The holotypes of the subspecies E. m. variabilis and Eudyptula minor chathamensis are in the collection of the Museum of New Zealand Te Papa Tangaroa. The white-flippered penguin is sometimes considered a subspecies of the little penguin, sometimes a separate species, and sometimes a colour morph. Genetic analyses indicate that the Australian and Otago (the southeastern coast of South Island) little penguins may constitute a distinct species. In this case the specific name minor would devolve on it, with the specific name novaehollandiae suggested for the other populations. This interpretation suggests that E. novaehollandiae individuals arrived in New Zealand between A.D. 1500 and 1900, while the local E. minor population had declined, leaving a genetic opening for a new species. Mitochondrial and nuclear DNA evidence suggests the split between Eudyptula and Spheniscus occurred around 25 million years ago, with the ancestors of the white-flippered and little penguins diverging about 2.7 million years ago. Description Like those of all penguins, the little penguin's wings have developed into flippers used for swimming. The little penguin typically grows to between tall and usually weighs about 1.5 kg on average (3.3 lb). The head and upper parts are blue in colour, with slate-grey ear coverts fading to white underneath, from the chin to the belly. Their flippers are blue in colour. The dark grey-black beak is 3–4 cm long, the irises pale silvery- or bluish-grey or hazel, and the feet pink above with black soles and webbing. An immature individual will have a shorter bill and lighter upperparts. Like most seabirds, they have a long lifespan. The average for the species is 6.5 years, but flipper ringing experiments show in very exceptional cases up to 25 years in captivity. Distribution and habitat The little penguin breeds along the entire coastline of New Zealand (including the Chatham Islands), and southern Australia (including roughly 20,000 pairs on Babel Island). Australian colonies exist in New South Wales, Victoria, Tasmania, South Australia, Western Australia and the Jervis Bay Territory. Little penguins have also been reported from Chile (where they are known as pingüino pequeño or pingüino azul) (Isla Chañaral 1996, Playa de Santo Domingo, San Antonio, 16 March 1997) and South Africa, but it is unclear whether these birds were vagrants. As new colonies continue to be discovered, rough estimates of the world population circa 2011 were around 350,000-600,000 animals. New Zealand Overall, little penguin populations in New Zealand have been decreasing. Some colonies have become extinct and others continue to be at risk. Some new colonies have been established in urban areas. The species is not considered endangered in New Zealand, with the exception of the white-flippered subspecies found only on Banks Peninsula and nearby Motunau Island. Since the 1960s, the mainland population has declined by 60-70%; though a small increase has occurred on Motunau Island. A colony exists in Wellington Harbor on Matiu/Somes Island. Australia Australian little penguin colonies primarily exist on offshore islands, where they are protected from feral terrestrial predators and human disturbance. Colonies are found from Port Stephens in northern New South Wales around the southern coast to Fremantle, Western Australia. Foraging penguins have occasionally been seen as far north as Southport, Queensland and Shark Bay, Western Australia. New South Wales An endangered population of little penguins exists at Manly, in Sydney's North Harbour. The population is protected under the NSW Threatened Species Conservation Act 1995 and has been managed in accordance with a Recovery Plan since the year 2000. The population once numbered in the hundreds, but has decreased to around 60 pairs of birds. The decline is believed to be mainly due to loss of suitable habitat, attacks by foxes and dogs and disturbance at nesting sites. The largest colony in New South Wales is on Montague Island. Up to 8000 breeding pairs are known to nest there each year. Additional colonies exist on the Tollgate Islands in Batemans Bay. Additional colonies exist in the Five Islands Nature Reserve, offshore from Port Kembla, and at Boondelbah Island, Cabbage Tree Island and the Broughton Islands off Port Stephens. Jervis Bay Territory A population of about 5,000 breeding pairs exists on Bowen Island. The colony has increased from 500 pairs in 1979 and 1500 pairs in 1985. During this time, the island was privately leased. The island was vacated in 1986 and is currently controlled by the federal government. South Australia In South Australia, many little penguin colony declines have been identified across the state. In some cases, colonies have declined to extinction (including the Neptune Islands, West Island, Wright Island, Pullen Island and several colonies on western Kangaroo Island), while others have declined from thousands of animals to few (Granite Island and Kingscote). The only known mainland colony exists at Bunda Cliffs on the state's far west coast, though colonies have existed historically on Yorke Peninsula. A report released in 2011 presented evidence supporting the listing of the statewide population or the more closely monitored sub-population from Gulf St. Vincent as Vulnerable under South Australia's National Parks & Wildlife Act 1972. As of 2014, the little penguin is not listed as a species of conservation concern, despite ongoing declines at many colonies. Tasmania Tasmanian has Australia's largest little penguin population, with estimates ranging from 110,000 to 190,000 breeding pairs, of which less than 5% are found on mainland Tasmania. Conservation activities, education campaigns, and measures to prevent dog attacks on little penguin rookeries have been implemented. Victoria The largest colony of little penguins in Victoria is located at Phillip Island, where the nightly 'parade' of penguins across Summerland Beach has been a major tourist destination, and more recently a major conservation effort, since the 1920s. Phillip Island is home to an estimated 32,000 breeding adults. Little penguins can also be seen in the vicinity of the St Kilda pier and breakwater in the inner suburbs of Melbourne. The breakwater is home to a colony of little penguins which have been the subject of a conservation study since 1986. As of 2020 the colony is 1,400 breeding adults and growing. Little penguin habitats also exist at a number of other locations, including London Arch and The Twelve Apostles along the Great Ocean Road, Wilsons Promontory and Gabo Island. Western Australia The largest colony of little penguins in Western Australia is believed to be located on Penguin Island, where an estimated 1,000 pairs nest during winter. Penguins are also known to nest on Garden Island and Carnac Island which lie north of Penguin Island. Many islands along Western Australia's southern coast are likely to support little penguin colonies, though the status of these populations is largely unknown. An account of little penguins on Bellinger Island published in 1928 numbered them in their thousands. Visiting naturalists in November 1986 estimated the colony at 20 breeding pairs. The account named another substantial colony 12 miles from Bellinger Island and the same distance from Cape Pasley. Little penguins are known to breed on some islands of the Recherche Archipelago, including Woody Island where day-tripping tourists can view the animals. A penguin colony exists on Mistaken Island in King George Sound near Albany. Historical accounts of little penguins on Newdegate Island at the mouth of Deep River and on Breaksea Island in King George Sound also exist. West Australian little penguins have been found to forage as far as 150 miles north of Geraldton (south of Denham and Shark Bay). Behaviour Little penguins are diurnal and like many penguin species, spend the largest part of their day swimming and foraging at sea. During the breeding and chick-rearing seasons, little penguins leave their nest at sunrise, forage for food throughout the day and return to their nests just after dusk. Thus, sunlight, moonlight and artificial lights can affect the behaviour of attendance to the colony. Also, increased wind speeds negatively affect the little penguins' efficiency in foraging for chicks, but for reasons not yet understood. Little penguins preen their feathers to keep them waterproof. They do this by rubbing a tiny drop of oil onto every feather from a special gland above the tail. Range Tagged or banded birds later recaptured or found deceased have shown that individual birds can travel great distances during their lifetimes. In 1984, a penguin that had been tagged at Gabo Island in eastern Victoria was found dead at Victor Harbor in South Australia. Another little penguin was found near Adelaide in 1970 after being tagged at Phillip Island in Victoria the previous year. In 1996, a banded penguin was found dead at Middleton. It had been banded in 1991 at Troubridge Island in Gulf St Vincent, South Australia. The little penguin's foraging range is quite limited in terms of distance from shore when compared to seabirds that can fly. Feeding Little penguins feed by hunting small clupeoid fish, cephalopods and crustaceans, for which they travel and dive quite extensively including to the sea floor. Researcher Tom Montague studied a Victorian population for two years in order to understand its feeding patterns. Montague's analysis revealed a penguin diet consisting of 76% fish and 24% squid. Nineteen fish species were recorded, with pilchard and anchovy dominating. The fish were usually less than 10 cm long and often post-larval or juvenile. Less common little penguin prey include: crab larvae, eels, jellyfish and seahorses. In New Zealand, important little penguin prey items include arrow squid, slender sprat, Graham's gudgeon, red cod and ahuru. Since the year 2000, the little penguins of Port Phillip Bay's diet has consisted mainly of barracouta, anchovy, and arrow squid. Pilchards previously featured more prominently in southern Australian little penguin diets prior to mass sardine mortality events of the 1990s. These mass mortality events affected sardine stocks over 5,000 kilometres of coastline. Jellyfish including species in the genera Chrysaora and Cyanea were found to be actively sought-out food items, while they previously had been thought to be only accidentally ingested. Similar preferences were found in the Adélie penguin, yellow-eyed penguin and Magellanic penguin. An important crustacean present in the little penguin diet is the krill, Nyctiphanes australis, which surface-swarms during the day. Little penguins are generally inshore feeders. The use of data loggers has shown that in the diving behaviour of little penguins, 50% of dives go no deeper than 2 m, and the mean diving time is 21 seconds. In the 1980s, average little penguin dive time was estimated to be 23–24 seconds. The maximum recorded depth and time submerged are 66.7 metres and 90 seconds respectively. Tracking technology is allowing researchers from IMAS and the University of Tasmania to garner new insights into the foraging behavior of little penguins. Parasites Little penguins play an important role in the ecosystem as not only a predator to parasites but also a host. Recent studies have shown a new species of feather mite that feeds on the preening oil on the feathers of the penguin. Little penguins preen their mates to strengthen social bonds and remove parasites, especially from their partner's head where self-preening is difficult. Reproduction Little penguins reach sexual maturity at different ages. The female matures at two years old and the male at three years old. Between June and August, males return to shore to renovate or dig new burrows and display to attract a mate for the season. Males compete for partners with their displays. Breeding occurs annually, but the timing and duration of the breeding season varies from location to location and from year to year. Breeding occurs during spring and summer when oceans are most productive and food is plentiful. Little penguins remain faithful to their partner during a breeding season and whilst hatching eggs. At other times of the year they tend to swap burrows. They exhibit site fidelity to their nesting colonies and nesting sites over successive years. Little penguins can breed as isolated pairs, in colonies, or semi-colonially. Nesting Penguins' nests vary depending on the available habitat. They are established close to the sea in sandy burrows excavated by the birds' feet or dug previously by other animals. Nests may also be made in caves, rock crevices, under logs or in or under a variety of man-made structures including nest boxes, pipes, stacks of wood or timber, and buildings. Nests have been occasionally observed to be shared with prions, while some burrows are occupied by short-tailed shearwaters and little penguins in alternating seasons. In the 1980s, little was known on the subject of competition for burrows between bird species. Timing The timing of breeding seasons varies across the species' range. In the 1980s, the first egg laid at a penguin colony on Australia's eastern coast could be expected to come as early as May or as late as October. Eastern Australian populations (including at Phillip Island, Victoria) lay their eggs from July to December. In South Australia's Gulf St. Vincent, eggs are laid between April and October and south of Perth in Western Australia, peak egg-laying occurred in June and continued until mid-October (based on observations from the 1980s). Male and female birds share incubating and chick-rearing duties. They are the only species of penguin capable of producing more than one clutch of eggs per breeding season, but few populations do so. In ideal conditions, a penguin pair is capable of raising two or even three clutches of eggs over an extended season, which can last between eight and twenty-eight weeks. The one or two (on rare occasions, three) white or lightly mottled brown eggs are laid between one and four days apart. Each egg typically weighs around 55 grams at time of laying. Incubation takes up to 36 days. Chicks are brooded for 18–38 days and fledge after 7–8 weeks. On Australia's east coast, chicks are raised from August to March. In Gulf St. Vincent, chicks are raised from June through November. Little penguins typically return to their colonies to feed their chicks at dusk. The birds tend to come ashore in small groups to provide some defence against predators, which might otherwise pick off individuals. In Australia, the strongest colonies are usually on cat-free and fox-free islands. However, the population on Granite Island (which is a fox, cat and dog-free island) has been severely depleted, from around 2000 penguins in 2001 down to 22 in 2015. Granite Island is connected to the mainland via a timber causeway. Native predators Predation by native animals is not considered a threat to little penguin populations, as these predators' diets are diverse. In Australia, large native reptiles including the tiger snake and Rosenberg's goanna are known to take little penguin chicks and blue-tongued lizards are known to take eggs. At sea, little penguins are eaten by long-nosed fur seals. A study conducted by researchers from the South Australian Research and Development Institute found that roughly 40 percent of seal droppings in South Australia's Granite Island area contained little penguin remains. Other marine predators include Australian sea lions, sharks and barracouta. The introduction of Tasmanian Devils to the Australian island of Maria Island in 2012 has led to the complete destruction of a population of little penguins that numbered 3,000 breeding pairs before the introduction. Little penguins are also preyed upon by white-bellied sea eagles. These large birds-of-prey are endangered in South Australia and not considered a threat to colony viability there. Other avian predators include: kelp gulls, pacific gulls, brown skuas and currawongs. In Victoria, at least one penguin death has been attributed to a water rat. Mass mortalities A mass mortality event occurred in Port Phillip Bay in March 1935. The event coincided with moulting and deaths were attributed to fatigue. Another event occurred at Phillip Island in Victoria in 1940. The population there was believed to have fallen from 2000 birds to 200. Dead birds were allegedly in healthy-looking condition so speculation pointed to a disease or pathogen. Oil spills resulting from shipping activity have occasionally resulted in mass mortalities of Little penguins. The worst of these was the Iron Baron oil spill at Low Head, Tasmania in 1995, followed by the Rena oil spill in New Zealand in 2011. Citizens have raised concerns about mass mortality of penguins alleging a lack of official interest in the subject. Discoveries of dead penguins in Australia should be reported to the corresponding state's environment department. In South Australia, a mortality register was established in 2011. Relationship with humans Little penguins have long been a curiosity to humans Captive animals are often exhibited in zoos. Over time attitudes towards penguins have evolved from direct exploitation (for meat, skins and eggs) to the development of tourism ventures, conservation management and the protection of both birds and their habitat. Direct exploitation During the 19th and 20th centuries, little penguins were shot for sport, killed for their skins, captured for amusement and eaten by ship-wrecked sailors and castaways to avoid starvation. Their eggs were also collected for human consumption by indigenous and non-indigenous people. In 1831, N. W. J. Robinson noted that penguins were typically soaked in water for many days to tenderise the meat before eating. One of the colonies raided for penguin skins was Lady Julia Percy Island in Victoria. The following directions for preparing penguin skin were published in The Chronicle in 1904:'F.W.M.,' Port Lincoln. — To clean penguin skins, scrape off as much fat as you can with a blunt knife. Then peg the skin out carefully, stretching it well. Let it remain in the sun till most of the fat is dried out of it, then rub with a compound of powdered alum, salt, and pepper in about equal proportions. Continue to rub this on at intervals until the skin becomes soft and pliable.An Australian taxidermist was once commissioned to make a woman's hat for a cocktail party from the remains of a dead little penguin. The newspaper described it as "a smart little toque of white and black feathers, with black flippers set at a jaunty angle on the crown." In the 20th century, little penguins were maliciously attacked by humans, used as bait to catch Southern rock lobster, used to free snagged fishing tackle, killed as incidental bycatch by fishermen using nets, and killed by vehicle strikes on roads and on the water. However, towards the end of the 20th century and the beginning of the 21st, more mutually beneficial relationships between penguins and humans developed. The sites of some breeding colonies have become carefully managed tourist destinations which provide an economic boost for coastal and island communities in Australia and New Zealand. These locations also often provide facilities and volunteer staff to support population surveys, habitat improvement works and little penguin research programs. Tourism At Phillip Island, Victoria, a viewing area has been established at the Phillip Island Nature Park to allow visitors to view the nightly "penguin parade". Lights and concrete stands have been erected to allow visitors to see but not photograph or film the birds (this is because it can blind or scare them) interacting in their colony. In 1987, more international visitors viewed the penguins coming ashore at Phillip Island than visited Uluru. In the financial year 1985–86, 350,000 people saw the event, and at that time audience numbers were growing 12% annually. In Bicheno, Tasmania, evening penguin viewing tours are offered by a local tour operator at a rookery on private land. A similar sunset tour is offered at Low Head, near the mouth of the Tamar River on Tasmania's north coast. Observation platforms exist near some of Tasmania's other little penguin colonies, including Bruny Island and Lillico Beach near Devonport. South of Perth, Western Australia, visitors to Penguin Island are able to view penguin feeding within a penguin rehabilitation centre and may also encounter wild penguins ashore in their natural habitat. The island is accessible via a short passenger ferry ride, and visitors depart the island before dusk to protect the colony from disturbance. Visitors to Kangaroo Island, South Australia, have nightly opportunities to observe penguins at the Kangaroo Island Marine Centre in Kingscote and at the Penneshaw Penguin Centre. Granite Island at Victor Harbor, South Australia continues to offer guided tours at dusk, despite its colony dropping from thousands in the 1990s to dozens in 2014. There is also a Penguin Centre located on the island where the penguins can be viewed in captivity. In the Otago, New Zealand town of Oamaru, visitors view the birds returning to their colony at dusk. In Oamaru it is common for penguins to nest within the cellars and foundations of local shorefront properties, especially in the old historic precinct of the town. Little penguin viewing facilities have been established at Pilots Beach on the Otago Peninsula in Dunedin. Here visitors are guided by volunteer wardens to watch penguins returning to their burrows at dusk. Threats Prey availability Food availability appears to strongly influence the survival and breeding success of little penguin populations across their range. Variation in prey abundance and distribution from year to year causes young birds to be washed up dead from starvation or in weak condition. This problem is not constrained to young birds, and has been observed throughout the 20th century. The breeding season of 1984–1985 in Australia was particularly bad, with minimal breeding success. Eggs were deserted prior to hatching and many chicks starved to death. Malnourished penguin carcasses were found washed up on beaches and the trend continued the following year. In April 1986, approximately 850 dead penguins were found washed ashore in south-western Victoria. The phenomenon was ascribed to lack of available food. There are two seasonal peaks in the discovery of dead little penguins in Victoria. The first follows moult and the second occurs in mid-winter. Moulting penguins are under stress, and some return to the water in a weak condition afterwards. Mid-winter marks the season of lowest prey availability, thus increasing the probability of malnutrition and starvation. In 1990, 24 dead penguins were found in the Encounter Bay area in South Australia during a week spanning late April to early May. A State government park ranger explained that many of the birds were juvenile and had starved after moulting. In 1995 pilchard mass mortality events occurred, which reduced the penguins' available prey and resulted in starvation and breeding failure. Another similar event occurred in 1999. Both mortality events were attributed to an exotic pathogen which spread across the entire Australian population of the fish, reducing the breeding biomass by 70%. Crested tern and gannet populations also suffered following these events. In 1995, 30 dead penguins were found ashore between Waitpinga and Chiton Rocks in the Encounter Bay area. The birds has suffered severe bacterial infections and the mortalities may have been linked to the mass mortality of pilchards that resulted from the spread of an exotic pathogen that year. In the late 1980s, it was believed that penguins did not compete with the fishing industry, despite anchovy being commercially caught. That assertion was made prior to the establishment and development of South Australia's commercial pilchard fishery in the 1990s. In South Africa, the overfishing of species of preferred penguin prey has caused Jackass penguin populations to decline. Overfishing is a potential (but not proven) threat to the little penguin. Introduced predators Introduced mammalian predators present the greatest terrestrial risk to little penguins and include cats, dogs, rats, foxes, ferrets and stoats. Dogs and cats Uncontrolled dogs or feral cats can have sudden and severe impacts on penguin colonies (more than the penguin's natural predators) and may kill many individuals. Examples of colonies affected by dog attacks include Manly, New South Wales, Penneshaw, South Australia, Red Chapel Beach, Wynyard, Camdale and Low Head in Tasmania, Penguin Island in Western Australia and Little Kaiteriteri Beach in New Zealand. Paw prints at an attack site at Freeman's Knob, Encounter Bay, South Australia showed that the dog responsible was small, roughly the size of a terrier. The single attack may have rendered the small colony extinct. Cats have been recorded preying on penguin chicks at Emu Bay on Kangaroo Island in South Australia. In October 2011, 15 dead penguin chicks were found near the Kingscote colony with their heads removed. A dog or cat attack was presumed to be the cause of death. A similar event also occurred in 2010. The threat of dog and cat attack is ongoing at many colonies and reports of dog attacks on penguins date back to the mid 20th century. In the first seven months of 2014, South Australian animal rescue organisation AMWRRO received and treated 22 penguins that had been injured during dog attacks. Foxes Foxes have been known to prey on little penguins since at least the early 20th century. A fox was believed responsible for the deaths of 53 little penguins over several nights on Granite Island in 1994. Little penguins on Middle Island off Warrnambool, Victoria have suffered heavy predation by foxes, which were able to reach the island at low tide by a tidal sand bridge. The small colony was reduced from approximately 600 penguins in 2001 to less than 10 in 2005. The use of Maremma sheepdogs to guard the colony has helped it recover to 100 birds by 2017. In June 2015, 26 penguins from the Manly colony were killed in 11 days. A fox believed responsible was eventually shot in the area and an autopsy was expected to prove or disprove its involvement. In November 2015 a fox entered the little penguin enclosure at the Melbourne Zoo and killed 14 penguins, prompting measures to further "fox proof" the enclosure. Ferrets and stoats A suspected stoat or ferret attack at Doctor's Point near Dunedin, New Zealand claimed the lives of 29 little blue penguins in November 2014. Tasmanian devils A population of Tasmanian devils introduced to Maria Island in 2012 for conservation reasons led to the loss of the local little penguin colony. Human development The impacts of human habitation in proximity to little penguin colonies include collisions with vehicles, direct harassment, burning and clearing of vegetation and housing development. In 1950, roughly a hundred little penguins were allegedly burned to death near The Nobbies at Port Phillip Bay during a grass fire lit intentionally by a grazier for land management purposes. It was later reported that the figure had been overstated. The matter was resolved when the grazier offered to return land to the custody of the State for the future protection of the colony. A study in Perth from 2003 to 2012 found that the main cause of mortality was trauma, most likely from watercraft, leading to a recommendation for management strategies to avoid watercraft strikes. The Conservation Council of Western Australia has expressed opposition to the proposed development of a marina and canals at Mangles Bay, in close proximity to penguin colonies at Penguin Island and Garden Island. Researcher Belinda Cannell of Murdoch University found that over a quarter of penguins found dead in the area had been killed by boats. Carcasses had been found with heads, flippers or feet cut off, cuts on their backs and ruptured organs. The development would increase boat traffic and result in more penguin deaths. Protestors have opposed the development of a marina at Kennedy Point, Waiheke Island in New Zealand for the risk it poses to Little penguins and their habitat. Protesters claimed that they exhausted all legal means to oppose the project and have had to resort to occupation and non-violent resistance. Several arrests have been made for trespassing. Human interference Penguins are vulnerable to interference by humans, especially while they are ashore during moult or nesting periods. In 1930 in Tasmania, it was believed that little penguins were competing with mutton-birds, which were being commercially exploited. An "open season" in which penguins would be permitted to be killed was planned in response to requests from members of the mutton-birding industry. In the 1930s, an arsonist was believed to have started a fire on Rabbit Island near Albany, Western Australia- a known little penguin rookery. Visitors later reported finding dead penguins there with their feet burned off. In 1938 an account was given of a little penguin found with its flippers tied together with fishing line. In 1949, penguins on Phillip Island in Victoria became victims of human cruelty, with some kicked and others thrown off a cliff and shot at. These acts of cruelty prompted the state government to fence off the rookeries. In 1973, ten dead penguins and fifteen young seagulls were found dead on Wright Island in Encounter Bay, South Australia. It was believed that they were killed by people poking sticks down burrows before scattering the dead bodies around, though a dog attack is also possible. In 1983 one penguin was found dead and another injured at Encounter Bay, both by human interference. The injured bird was euthanased. More recent examples of destructive interference can be found at Granite Island, where in 1994 a penguin chick was taken from a burrow and abandoned on the mainland, a burrow containing penguin chicks was trampled and litter was discarded down active burrows. In 1998, two incidents in six months resulted in penguin deaths. The latter, which occurred in May, saw 13 penguins apparently kicked to death. In March 2016, two little penguins were kicked and attacked by humans during separate incidents at the St Kilda colony, Victoria. In 2018, 20-year-old Tasmanian man Joshua Leigh Jeffrey was fined $82.50 in court costs and sentenced to 49 hours of community service at Burnie Magistrates Court after killing nine little penguins at Sulphur Creek in North West Tasmania on 1 January 2016 by beating them with a stick. Dr Eric Woehler from conservation group Birds Tasmania denounced the perceived leniency of the sentence, which he said placed minimal value on Tasmania's wildlife and set an "unwelcome precedent". Following an appeal by prosecutors, Jeffrey had his sentence doubled on 15 October 2018. The office of the Director of Public Prosecutions said it considered the original sentence to be manifestly inadequate. The original sentence was set aside, and Jeffrey was sentenced to two months in prison, suspended on the condition of him committing no offences for a year that are punishable by imprisonment. His community order was also doubled to 98 hours. Also in 2018, a dozen little penguin carcasses were found in a garbage bin at Low Head, Tasmania prompting an investigation into the causes of death. Interactions with fishing Some little penguins are drowned when amateur fishermen set gill nets near penguin colonies. Discarded fishing line can also present an entanglement risk and contact can result in physical injury, reduced mobility or drowning. In 2014, a group of 25 dead little penguins was found on Altona Beach in Victoria. Necropsies concluded that the animals had died after becoming entangled in net fishing equipment, prompting community calls for a ban on net fishing in Port Phillip Bay. In the 20th century, little penguins were intentionally shot or caught by fishermen to use as bait in pots for catching Southern rock lobster (also known as crayfish) or by line fishermen. Colonies were targeted for this purpose in various parts of Tasmania including Bruny Island and at West Island, South Australia. Oil spills Oil spills can be lethal for penguins and other sea birds and events related ports and shipping have impacted penguins across the Southern hemisphere since the 1920s. Oil is toxic when ingested and penguins' buoyancy and the insulative quality of their plumage is damaged by contact with oil. Little penguin populations have been significantly affected during two major oil spills at sea: the Iron Baron oil spill off Tasmania's north coast in 1995 and the grounding of the Rena off New Zealand in 2011. In 2005, a 10-year post-mortem reflection on the Iron Baron incident estimated penguin fatalities at 25,000. The Rena incident killed 2,000 seabirds (including little penguins) directly, and killed an estimated 20,000 in total based on wider ecosystem impacts. Victoria's coastline has been subjected to chronic oil contamination from minor discharges or spills which have impacted little penguins at several colonies. An oil spill or dumping event claimed the lives of up to 120 little penguins which were found oiled, deceased and ashore near Warnambool in 1990. A further 104 penguins were taken into care for cleaning. The waters west of Cape Otway were polluted with bunker oil. The source was unknown at the time and an investigation was started into three potentially responsible vessels. Earlier oil spill or oil dumping events have injured or killed little penguins at various locations in the 1920s, 1930s, 1940s, 1950s, 1960s and 1970s. The threat persists in the 21st century, with oiled birds received for treatment at specialised facilities like AMWRRO in South Australia. Plastic pollution Plastics are swallowed by little penguins, who mistake them for prey items. They present a choking hazard and also occupy space in the animal's stomach. Indigestible material in a penguin's stomach can contribute to malnutrition or starvation. Other larger plastic items, such as bottle packaging rings, can become entangled around penguins' necks, affecting their mobility. Climate change Heat waves can result in mass mortality episodes at nesting sites, as the penguins have poor physiological adaptations towards losing heat. Climate change is recognised as a threat, though currently it is assessed to be less significant than others. Efforts are being made to protect penguins in Australia from the likely future increased occurrence of extreme heat events. Variation in the timing of seasonal ocean upwelling events, such as the Bonney Upwelling, which provide abundant nutrients vital to the growth and reproduction of primary producers at the base of the food chain, may adversely affect prey availability, and the timing and success or failure of little penguin breeding seasons. Conservation Little penguins are protected from various threats under different legislation in different jurisdictions. The table below may not be exhaustive. Management of introduced predators Management strategies to mitigate the risk of domestic and feral dog and cats attack include establishing dog-free zones near penguin colonies and introducing regulations to ensure dogs to remain on leashes at all times in adjacent areas. The threat of colony collapse at Warnambool prompted conservationists to pioneer the experimental use of Maremma Sheepdogs to protect the colony and fend off would-be predators. The deployment of Maremma sheepdogs to protect the penguin colony has deterred the foxes and enabled the penguin population to rebound. This is in addition to the support from groups of volunteers who work to protect the penguins from attack at night. The first Maremma sheepdog to prove the concept was Oddball, whose story inspired a feature film of the same name, released in 2015. In December 2015, the BBC reported, "The current dogs patrolling Middle Island are Eudy and Tula, named after the scientific term for the fairy penguin: Eudyptula. They are the sixth and seventh dogs to be used and a new puppy is being trained up [...] to start work in 2016. In Sydney, snipers have been used to protect a colony of little penguins. This effort is in addition to support from local volunteers who work to protect the penguins from attack at night. In 2019 it was announced that the defensive strategies were paying off and that Manly colony was recovering. Near some colonies in Tasmania, traps are set and feral cats that are captured are euthanized. Habitat restoration Several efforts have been made to improve breeding sites on Kangaroo Island, including augmenting habitat with artificial burrows and revegetation work. The Knox School's habitat restoration efforts were filmed and broadcast in 2008 by Totally Wild. In 2019, concrete nesting "huts" were made for the little penguins of Lion Island in the mouth of the Hawkesbury River in New South Wales, Australia. The island had been ravaged by a fire which began with a lightning strike and destroyed 85% of the penguin's natural habitat. Weed control undertaken by the Friends of Five Islands in New South Wales helps improve prospects of breeding success for seabirds, including the little penguin. The main problem species on the Five Islands are kikuyu grass and coastal morning glory. The weeding work has resulted in increasing numbers of little penguin burrows in the areas weeded and the return of the white-faced storm petrel to the island after a 56-year breeding absence. Oil spill response Penguins are taken into care and cleaned by trained staff at specialised facilities when they are found alive in an oiled condition. When animals are first received at Phillip Island's rehabilitation facility, a knitted penguin sweater, made to a specific pattern, is applied to the bird. The sweater prevents the bird from attempting to preen off the oil itself. Once the birds have been treated and cleaned, the jumper is discarded. In 2019, the Phillip Island centre put out a call for 1,400 new penguin jumpers to be knitted after they increased the carrying capacity of their treatment facility. The last major oil spill the centre responded to saw 438 birds cleaned with a 96% survival rate after rehabilitation. The Melbourne Zoo also treats and rehabilitates oiled little penguins, and the Taronga Zoo has been cleaning and rehabilitating oiled penguins since the 1950s. Zoological exhibits Zoological exhibits featuring purpose-built enclosures for little penguins can be seen in Australia at the Adelaide Zoo, Melbourne Zoo, the National Zoo & Aquarium in Canberra, Perth Zoo, Caversham Wildlife Park (Perth), Ballarat Wildlife Park, Sea Life Sydney Aquarium and the Taronga Zoo in Sydney. Enclosures include nesting boxes or similar structures for the animals to retire into, a reconstruction of a pool and in some cases, a transparent aquarium wall to allow patrons to view the animals underwater while they swim. A little penguin exhibit exists at Sea World, on the Gold Coast, Queensland, Australia. In early March, 2007, 25 of the 37 penguins died from an unknown toxin following a change of gravel in their enclosure. It is still not known what caused the deaths of the little penguins, and it was decided not to return the 12 surviving penguins to the same enclosure where the penguins became ill. A new enclosure for the little penguin colony was opened at Sea World in 2008. In New Zealand, little penguin exhibits exist at the Auckland Zoo, the Wellington Zoo and the National Aquarium of New Zealand. Since 2017, the National Aquarium of New Zealand, has featured a monthly "Penguin of the Month" board, declaring two of their resident animals the "Naughty" and "Nice" penguin for that month. Photos of the board have gone viral and gained the aquarium a large worldwide social media following. A colony of little blue penguins exists at the New England Aquarium in Boston, Massachusetts. The penguins are one of three species on exhibit and are part of the Association of Zoos and Aquariums' Species Survival Plan for little blue penguins. Little penguins can also be seen at the Louisville Zoo and the Bronx Zoo. Mascots and logos Linus Torvalds, the original creator of Linux (a popular operating system kernel), was once pecked by a little penguin while on holiday in Australia. Reportedly, this encounter encouraged Torvalds to select Tux as the official Linux mascot. A Linux kernel programming challenge called the Eudyptula Challenge has attracted thousands of persons; its creator(s) use the name "Little Penguin". Penny the Little Penguin was the mascot for the 2007 FINA World Swimming Championships held in Melbourne, Victoria. See also References Further reading External links State of Penguins: Little (blue) penguin – detailed and current species account of (Eudyptula minor) in New Zealand Little penguins at the International Penguin Conservation Little penguin at PenguinWorld West Coast Penguin Trust (New Zealand) Philip Island Nature Park website Gould's The Birds of Australia plate little penguin little penguin Birds of Western Australia Birds of South Australia Birds of Victoria (Australia) Birds of Tasmania Birds of New Zealand Subterranean nesting birds little penguin	[ -0.8105555176734924, -0.024970877915620804, -0.41482970118522644, -0.1521560698747635, 0.1741660088300705, 0.42320770025253296, 0.2764517366886139, 0.5476500391960144, -0.9280422925949097, -0.162303164601326, 0.03583865612745285, -0.42238035798072815, -0.2959195077419281, 0.335211068391799...
18233	https://en.wikipedia.org/wiki/Lake%20Balaton	Lake Balaton	Lake Balaton (, , , , , Slovene: Blatno jezero) is a freshwater lake in the Transdanubian region of Hungary. It is the largest lake in Central Europe, and one of the region's foremost tourist destinations. The Zala River provides the largest inflow of water to the lake, and the canalised Sió is the only outflow. The mountainous region of the northern shore is known both for its historic character and as a major wine region, while the flat southern shore is known for its resort towns. Balatonfüred and Hévíz developed early as resorts for the wealthy, but it was not until the late 19th century when landowners, ruined by Phylloxera attacking their grape vines, began building summer homes to rent out to the burgeoning middle classes. Name In distinction to all other endonyms for lakes, which universally bear the identifying suffix -tó ("lake"), Lake Balaton is referred to in Hungarian with a definite article, ie. a Balaton (the Balaton). It was called lacus Pelsodis or Pelso by the Romans. The name is Indo-European in origin (cf. Czech pleso 'sinkhole, deep end of a lake'), later replaced by the Slavic *bolto (Czech bláto, Slovak blato, Polish błoto) meaning 'mud, swamp' (from earlier Proto-Slavic boltьno, , ). In January 846 Slavic prince Pribina began to build a fortress as his seat of power and several churches in the region of Lake Balaton, in a territory of modern Zalavár surrounded by forests and swamps along the river Zala. His well-fortified castle and capital of Lower Pannonian Principality that became known as Blatnohrad or Moosburg ("Swamp Fortress") served as a bulwark both against the Bulgarians and the Moravians. The German name for the lake is . It is unlikely it was given that name for being shallow since the adjective is a Greek loanword that was borrowed via French and entered the general German vocabulary in the 17th century. It is also noteworthy that the average depth of Balaton () is not extraordinary for the area (cf. the average depth of the neighbouring Neusiedler See, which is roughly ). Climate Lake Balaton affects the local area precipitation. The area receives approximately more precipitation than most of Hungary, resulting in more cloudy days and less extreme temperatures. The lake's surface freezes during winters. The microclimate around Lake Balaton has also made the region ideal for viticulture. The Mediterranean-like climate, combined with the soil (containing volcanic rock), has made the region notable for its production of wines since the Roman period two thousand years ago. History While a few settlements on Lake Balaton, including Balatonfüred and Hévíz, have long been resort centres for the Hungarian aristocracy, it was only in the late 19th century that the Hungarian middle class began to visit the lake. The construction of railways in 1861 and 1909 increased tourism substantially, but the post-war boom of the 1950s was much larger. By the turn of the 20th century, Balaton had become a center of research by Hungarian biologists, geologists, hydrologists, and other scientists, leading to the country's first biological research institute being built on its shore in 1927. The last major German offensive of World War II, Operation Frühlingserwachen, was conducted in the region of Lake Balaton in March 1945, being referred to as "the Lake Balaton Offensive" in many British histories of the war. The battle was a German attack by Sepp Dietrich's Sixth Panzer Army and the Hungarian Third Army between 6 March and 16 March 1945, and in the end, resulted in a Red Army victory. Several Ilyushin Il-2 wrecks have been pulled out of the lake after having been shot down during the later months of the war. During the 1960s and 1970s, Balaton became a major tourist destination due to focused government efforts, causing the number of overnight guests in local hotels and campsites to increase from 700,000 in July 1965 to two million in July 1975. Weekend visitors to the region, including tens of thousands from Budapest, reached more than 600,000 by 1975. It was visited by ordinary working Hungarians and especially for subsidised holiday excursions for labor union members. It also attracted many East Germans and other residents of the Eastern Bloc. West Germans could also visit, making Balaton a common meeting place for families and friends separated by the Berlin Wall until 1989. Tourism The major resorts around the lake are Siófok, Keszthely, and Balatonfüred. Zamárdi, another resort town on the southern shore, has been the site of Balaton Sound, a notable electronic music festival since 2007. Balatonkenese has hosted numerous traditional gastronomic events. Siófok is known for attracting young people to it because of its large clubs. Keszthely is the site of the Festetics Palace and Balatonfüred is a historical bathing town which hosts the annual Anna Ball. The peak tourist season extends from June until the end of August. The average water temperature during the summer is , which makes bathing and swimming popular on the lake. Most of the beaches consist of either grass, rocks, or the silty sand that also makes up most of the bottom of the lake. Many resorts have artificial sandy beaches and all beaches have step access to the water. Other tourist attractions include sailing, fishing, and other water sports, as well as visiting the countryside and hills, wineries on the north coast, and nightlife on the south shore. The Tihany Peninsula is a historical district. Badacsony is a volcanic mountain and wine-growing region as well as a lakeside resort. The lake is almost completely surrounded by separated bike lanes to facilitate bicycle tourism. Although the peak season at the lake is the summer, Balaton is also frequented during the winter, when visitors go ice-fishing or even skate, sledge, or ice-sail on the lake if it freezes over. Sármellék International Airport provides air service to Balaton (although most service is only seasonal). Other resort towns include: Balatonalmádi, Balatonboglár, Balatonlelle, Fonyód and Vonyarcvashegy. Towns and villages North shore From east to west: Balatonfőkajár - Balatonakarattya - Balatonkenese - Balatonfűzfő - Balatonalmádi - Alsóörs - Paloznak - Csopak - Balatonarács - Balatonfüred - Tihany - Aszófő - Örvényes - Balatonudvari - Fövenyes - Balatonakali - Zánka - Balatonszepezd - Szepezdfürdő - Révfülöp - Pálköve - Ábrahámhegy - Balatonrendes - Badacsonytomaj - Badacsony - Badacsonytördemic - Szigliget - Balatonederics - Balatongyörök - Vonyarcvashegy - Gyenesdiás - Keszthely South shore From east to west: Balatonakarattya - Balatonaliga - Balatonvilágos - Sóstó - Szabadifürdő - Siófok - Széplak - Zamárdi - Szántód - Balatonföldvár - Balatonszárszó - Balatonszemes - Balatonlelle - Balatonboglár - Fonyód - Fonyód–Alsóbélatelep - Bélatelep - Balatonfenyves - Balatonmáriafürdő - Balatonkeresztúr - Balatonberény - Fenékpuszta Gallery See also Balaton Principality Balaton Uplands National Park Geography of Hungary References External links Balaton Ramsar sites in Hungary	[ -0.21638458967208862, 0.5272374153137207, 0.4446682929992676, -0.12103523313999176, 0.3783816397190094, 0.5070738792419434, 0.5630006790161133, 0.6777153015136719, -0.5382636189460754, 0.07565726339817047, -0.18876412510871887, -0.43189311027526855, -0.4355457127094269, 0.692753791809082, ...
18234	https://en.wikipedia.org/wiki/Libro%20de%20los%20Juegos	Libro de los Juegos	The Libro de los Juegos ("Book of games"), or Libro de axedrez, dados e tablas ("Book of chess, dice and tables", in Old Spanish), was commissioned by Alfonso X of Castile, Galicia and León and completed in his scriptorium in Toledo in 1283. It contains the earliest European treatise on chess as well as being the oldest document on European tables games, and is an exemplary piece of Alfonso's medieval literary legacy. Significance The Libro de los Juegos is one of the most important documents for researching the history of board games. This "celebrated MS book of games" has been described as "one of the choicest treasures of the library of the Escorial" as well as the "perhaps the greatest source of information on board games ever compiled during the Middle Ages." It is both "the earliest treatise on chess and the oldest document relating to tables which have had their origin in Europe." Description The book consists of ninety-seven leaves of parchment, many with color illustrations, and contains 150 miniatures. The text is a treatise that addresses the playing of three games: a game of skill, or chess; a game of chance, or dice; and a third game, backgammon, which combines elements of both skill and chance. These games are discussed in the final section of the book at both an astronomical and astrological level. Examining further, the text can also be read as an allegorical initiation tale and as a metaphysical guide for leading a balanced, prudent, and virtuous life. In addition to the didactic, although not overly moralistic, aspect of the text, the manuscript's illustrations reveal a rich cultural, social, and religious complexity. Location The earliest manuscript is in the library of the monastery of El Escorial near Madrid in Spain, as manuscript T.I.6. It is bound in sheepskin and is 40 cm high and 28 cm wide (16 in × 11 in). A 1334 copy is held in the library of the Spanish Royal Academy of History in Madrid. Background Alfonso was likely influenced by his contact with scholars in the Arab world. Unlike many contemporary texts on the topic, he does not engage the games in the text with moralistic arguments; instead, he portrays them in an astrological context. He conceives of gaming as a dichotomy between the intellect and chance. The book is divided into three parts reflecting this: the first on chess (a game purely of abstract strategy), the second on dice (with outcomes controlled strictly by chance), and the last on tables (combining elements of both). The text may have been influenced by Frederick II's text on falconry. Chess The Libro de juegos contains an extensive collection of writings on chess, with over 100 chess problems and variants. Among its more notable entries is a depiction of what Alfonso calls the ajedrex de los quatro tiempos ("chess of the four seasons"). This game is a chess variant for four players, described as representing a conflict between the four elements and the four humors. The chessmen are marked correspondingly in green, red, black, and white, and pieces are moved according to the roll of dice. Alfonso also describes a game entitled "astronomical chess", played on a board of seven concentric circles, divided radially into twelve areas, each associated with a constellation of the Zodiac. Another variant described in the book is the "Grant Acedrex", played over a 12x12 board with alternative pieces as the giraffe and the unicornio. Tables The book describes the rules for a number of games in the tables family. One notable entry is todas tablas, the equivalent of the Anglo-Scottish game of Irish, which has several similarities to modern backgammon including an identical starting position and the same rules for movement and bearing off. Alfonso also describes a variant played on a board with seven points in each table. Players rolled seven-sided dice to determine the movement of pieces, an example of Alfonso's preference for the number seven. The tables games described are: Quinze Tablas (Fifteen Pieces) Doce Canes or Doce Hermanos (Twelve Dogs or Twelve Brothers) Doblet (Doublet), related to the English game of Doublets Fallas (Drop Dead), related to the English game of Fayles Seys Does e As (Six, Two and Ace), related to the English game of Six-Ace Emperador (Emperor) Medio-Emperador (Half Emperor) Paireia de Entrada (Paired Entry) Cab e Quinal (Alongside Fives) Todas Tablas (All Pieces), related to the Anglo-Scottish game of Irish Laquet, related to the French game of Jacquet Buffa Cortesa (Courtly Puff), related to the German game of Puff Buffa de Baldrac (Common Puff) Rencontrat Art The miniatures in the Libro de juegos vary between half- and full-page illustrations. The half-page miniatures typically occupy the upper half of a folio, with text explaining the game "problem" solved in the image occupying the bottom half. The back or second (verso) side of Folio 1, in a half-page illustration, depicts the initial stages of the creation of the Libro de juegos, accompanied by text on the bottom half of the page, and the front or first (recto) side of Folio 2 depicts the transmission of the game of chess from an Indian Philosopher-King to three followers. The full-page illustrations are almost exclusively on the verso side of later folios and are faced by accompanying text on the recto side of the following folio. The significance of the change in miniature size and placement may indicate images of special emphasis, could merely function as a narrative or didactic technique, or could indicate different artisans at work in Alfonso's scriptorium as the project developed over time. Having multiple artisans working on the Libro de juegos would have been a typical practice for medieval chanceries and scriptoria, where the labor of producing a manuscript was divided amongst individuals of varying capacities, for example the positions of scribe, draftsman, and apprentice cutting pages. But in addition to performing different tasks, various artisans could have labored at the same job, such as the work of illustration in the Libro de juegos, thereby revealing a variety hands or styles. The Libro de Juegos offers such evidence in the difference in size between the half- and full-page illustrations in addition to changes in framing techniques amongst the folios: geometrical frames with embellished corners, architectural frames established by loosely perspectival rooftops and colonnades, and games played under tents. Other stylistic variances are found in figural representation, in facial types, and in a repertoire of different postures assumed by the players in different folios in the manuscript. For example, in a comparison of two miniatures, found on Folios 53v and 76r, examples of these different styles are apparent, although the trope of a pair of gamers is maintained. In Folio 53v, two men are playing chess, both wearing turbans and robes. Although they may be seated on rugs on the ground, as suggested by the ceramic containers that are placed on or front of the rug near the man on the right side of the board, the figures' seated positions, which are full frontal with knees bent at right angles, suggests that they are seated on stools or perhaps upholstered benches. The figures' robes display a Byzantine conservatism, with their modeled three-dimensionality and allusion to a Classical style, yet the iconic hand gestures are reminiscent of a Romanesque energy and theatricality. Although the figures are seated with their knees and torsos facing front, their shoulders and heads rotate in three-quarter profile toward the center of the page, the chess board, and each other. The proximal, inner arm of each player (the arm that is closest to the board) is raised in a speaking gesture; the distal, outside arms of the players are also raised and are bent at the elbows, creating a partial crossing of each player's torso as the hands lift in speaking gestures. The faces reveal a striking specificity of subtle detail, particular to a limited number of miniatures throughout the Libro de juegos, perhaps indicative of a particular artist's hand. These details include full cheeks, realistic wrinkles around the eyes and across the brow, and a red, full-lipped mouth that hints at the Gothic affectations in figural representation coming out of France during the late twelfth and early thirteenth centuries. The style in the miniature in Folio 76v is markedly different from the style in Folio 53v. In this case, the framed miniature contains two men, perhaps Spanish, with uncovered wavy light brown hair that falls to the jaw line. The men seem young, as the player on the left has no facial hair and his face is unlined. In both folios, both pairs of players are playing backgammon and seem to be well-dressed, although there is no addition of gold detailing to their robes as seen in the wardrobes of aristocratic players in other miniatures. These players are seated on the ground, leaning on pillows that are placed next to a backgammon board. In this miniature, the figure on the left side of the board faces the reader, while the figure on the right leans in to the board with his back to the reader. In other words, each player is leaning on his left elbow, using his right hand to reach across his body to play. In the miniatures of this style, the emphasis seems to be more on the posture of the player than the detail of their faces; this crossed, lounging style is only found in the folios of the Libro de tablas, the third section of the Libro de juegos which explains the game of backgammon, again perhaps indicative of the work of a particular artist. Other visual details contemporaneous of Alfonso's court and social and cultural milieu infuse the Libro de juegos. Although some of the miniatures are framed by simple rectangles with corners embellished by the golden castles and lions of Castile and León, other are framed by medieval Spanish architectural motifs, including Gothic and Mudéjar arcades of columns and arches. At times, the figural depictions are hierarchical, especially in scenes with representations of Alfonso, where the king is seated on a raised throne while dictating to scribes or meting out punishments to gamblers. Yet a contemporary atmosphere of Spanish convivencia is evoked by the inclusion nobility, rogues, vagrants, young and old, men, women, Christian, Muslim, and Jewish characters. Alfonso himself is depicted throughout the text, both as participant and spectator and as an older man and as a younger. The pages are filled with many social classes and ethnicities in various stages of solving the challenges presented by games. Iconography The Libro de juegos can be divided into three parts: the games and problems it explores textually, the actual illuminations themselves, and the metaphysical allegories, where an analysis of the texts and illuminations reveals the movements of the macrocosmos of the universe and the microcosmos of man. The symbolism within the medieval illuminations, as explained by the accompanying texts, reveal allusions to medieval literature, art, science, law and philosophy. Intended as a didactic text, the manuscript functions as a manual that documents and explains how and why one plays games ranging from pure, intellectual strategy (chess), to games of pure chance (dice), to games that incorporate both elements (backgammon). Conceivably, Alfonso hoped to elucidate for himself how to better play the game of life, while also providing a teaching tool for others. The game of ajedrex, or chess, is not the only game explained in the Libro de Juegos, but it does occupy the primary position in the text and is given the most attention to detail. In the thirteenth century, chess had been played in Europe for almost two hundred years, having been introduced into Europe by Arabs around the year 1000. The Arabs had become familiar with the game as early as the eighth century when the Islamic empire conquered Persia, where the game of chess was alleged to have been originated. It is said that a royal advisor had invented the game in order to teach his king prudence without having to overtly correct him. As Arab contact with the West expanded, so too did the game and its various permutations, and by the twelfth century, chess was becoming an entertaining diversion among a growing population of Europeans, including some scholars, clergy, the aristocracy, and the merchant classes; thus, by the thirteenth century, the iconography and symbolism associated with chess would have been accessible and familiar to Alfonso and his literate court culture, who may have had access to the private library, and manuscripts, of Alfonso, including the Libro de juegos. The Libro de juegos manuscript was a Castilian translation of Arabic texts, which were themselves translations of Persian manuscripts. The visual trope portrayed in the Libro de juegos miniatures is seen in other European transcriptions of the Arabic translations, most notably the German Carmina Burana Manuscript: two figures, one on either side of the board, with the board tilted up to reveal to the readers the moves made by the players. The juxtaposition of chess and dice in Arabic tradition, indicating the opposing values of skill (chess) and ignorance (dice), was given a different spin in Alfonso's manuscript, however. As Alfonso elucidates in the opening section of the Libro de Juegos, the Libro de ajedrex (Book of chess) demonstrates the value of the intellect, the Libro de los dados (Book of dice) illustrates that chance has supremacy over pure intellect, and the Libro de las tablas (Book of tables) celebrates a conjoined use of both intellect and chance. Further, the iconographic linkage between chess and kingship in the Western tradition continued to evolve and became symbolic of kingly virtues, including skill, prudence, and intelligence. Significance Most of the work accomplished in Alfonso's scriptorium consisted of translations into the Spanish vernacular from Arabic translations of Greek texts or classical Jewish medicinal texts. As a result, very few original works were produced by this scholar-king, relative to the huge amount of work that was translated under his auspices. This enormous focus on translation was perhaps an attempt by Alfonso to continue the legacy of academic openness in Castile, initiated by Islamic rulers in Córdoba, where the emirates had also employed armies of translators in order to fill their libraries with Arabic translations of classic Greek texts. Alfonso was successful in promoting Castilian society and culture through his emphasis on the use of Galaico-Portuguese and Castilian, in academic, juridical, diplomatic, literary, and historical works. This emphasis also had the effect of reducing the universality of his translated works and original academic writings, as Latin was the lingua franca in both Iberia and Europe; yet Alfonso never desisted in his promotion of the Castilian vernacular. Legacy In 1217, Alfonso had captured the Kingdom of Murcia, on the Mediterranean coast south of Valencia, for his father, King Alfonso IX, thereby unifying the kingdoms of Castile and León, bringing together the northern half of the Iberian Peninsula under one Christian throne. With the Christian re-conquest of the Peninsula underway, inroads into Islamic territories were successfully incorporating lands previously held by the taifa kingdoms. The arts and sciences prospered in the Kingdom of Castile under the confluence of Latin and Arabic traditions of academic curiosity as Alfonso sponsored scholars, translators, and artists of all three religions of the Book (Jewish, Christian, and Muslim) in his chanceries and scriptoria. Clerical and secular scholars from Europe turned their eyes to Iberian Peninsula as the arts and sciences prospered in an early Spanish "renaissance" under the patronage of Alfonso X, who was continuing the tradition of (relatively) enlightened and tolerant convivencia established by the Muslim emirate several centuries earlier. As an inheritor of a dynamic mixture of Arabic and Latin culture, Alfonso was steeped in the rich heritage of humanistic philosophy, and the production of his Libro de juegos reveals the compendium of world views that comprised the eclectic thirteenth century admixture of faith and science. According to this approach, man's actions could be traced historically and his failures and successes could be studied as lessons to be applied to his future progress. These experiences can be played out and studied as they are lived, or as game moves played and analyzed in the pages of the Libro de juegos. It is a beautiful and luxurious document, rich not only in workmanship but also in the amount of scholarship of multiple medieval disciplines that are integrated in its pages. See also Literature of Alfonso X Astronomical chess Scachs d'amor References Further reading Canettieri, Paolo, "A critical edition of The Book of Games". Google Knol collection. Canettieri, Paolo, "The Book of Games: A bibliography". Google Knol collection. Canettieri, Paolo, "The Book of Games: A critical edition" (Italian: "ALFONSO X EL SABIO – Il Libro dei giochi – Introduzione, edizione e commento"). Google Knol collection. Cazaux, Jean-Louis and Rick Knowlton (2017). A World of Chess. Jefferson, NC: McFarland. Fiske, Willard (1905). Chess in Iceland and in Icelandic literature: with Historical Notes on other Table-Games. Florence: Florentine Typographical Society. Golladay, Sonja Musser, "Alfonso X's Book of Games: A translation" (old link archived from the University of Arizona: A translation) (PDF version) Cf. especially section on "The Alfonso X 'Book of Games'". Vazquez-Campos, Braulio, "Alfonso X and Chess" (Spanish: "Alfonso X y el ajedrez"). Google Knol collection. External links Alphonso X Book of Games at RenGeekCentral Elliot Avedon Museum & Archive of Games Focus on Chess variants from Alfonso's codex 13th-century books 13th century in chess Medieval chess Chess books Chess in Spain Books about board games 13th century in Castile	[ -0.19135567545890808, 0.38798844814300537, 0.004819468129426241, 0.33975696563720703, -0.2218690663576126, 0.375887006521225, -0.5858533978462219, 0.6971306204795837, -0.3699023425579071, -0.4073737561702728, 0.39181989431381226, 0.6582700610160828, 0.15891043841838837, 0.02844810299575329...
18236	https://en.wikipedia.org/wiki/Lithium%20citrate	Lithium citrate	Lithium citrate (Li3C6H5O7) is a chemical compound of lithium and citrate that is used as a mood stabilizer in psychiatric treatment of manic states and bipolar disorder. There is extensive pharmacology of lithium, the active component of this salt. Lithia water contains various lithium salts, including the citrate. An early version of Coca-Cola available in pharmacies' soda fountains called Lithia Coke was a mixture of Coca-Cola syrup and lithia water. The soft drink 7Up was originally named "Bib-Label Lithiated Lemon-Lime Soda" when it was formulated in 1929 because it contained lithium citrate. The beverage was a patent medicine marketed as a cure for hangover. Lithium citrate was removed from 7Up in 1948. References Citrates Lithium compounds Mood stabilizers Organolithium compounds	[ -0.2618970274925232, 0.35207971930503845, -0.1969994455575943, -0.2053074687719345, -0.21612180769443512, -0.003930219449102879, 0.26564085483551025, 0.06256406754255295, 0.22030314803123474, 0.705629289150238, -0.3066674470901489, 0.5245137810707092, -0.3465454578399658, 0.296123594045639...
18237	https://en.wikipedia.org/wiki/Lithium%20carbonate	Lithium carbonate	Lithium carbonate is an inorganic compound, the lithium salt of carbonate with the formula . This white salt is widely used in the processing of metal oxides. It is listed on the World Health Organization's List of Essential Medicines because it can be used as a treatment for mood disorders such as bipolar disorder. Uses Lithium carbonate is an important industrial chemical. Its main use is as a precursor for compounds used in lithium-ion batteries. Glasses derived from lithium carbonate are useful in ovenware. Lithium carbonate is a common ingredient in both low-fire and high-fire ceramic glaze. It forms low-melting fluxes with silica and other materials. Its alkaline properties are conducive to changing the state of metal oxide colorants in glaze, particularly red iron oxide (). Cement sets more rapidly when prepared with lithium carbonate, and is useful for tile adhesives. When added to aluminium trifluoride, it forms LiF which gives a superior electrolyte for the processing of aluminium. Rechargeable batteries The main use of lithium carbonate (and lithium hydroxide) is as a precursor to lithium compounds used in lithium-ion batteries. In practice two components of the battery are made with lithium compounds: the cathode and the electrolyte. The electrolyte is a solution of lithium hexafluorophosphate, while the cathode uses one of several lithiated structures, the most popular of which are lithium cobalt oxide and lithium iron phosphate. Lithium carbonate may be converted into lithium hydroxide before conversion to the compounds above. Medical uses In 1843, lithium carbonate was used as a new solvent for stones in the bladder. In 1859, some doctors recommended a therapy with lithium salts for a number of ailments, including gout, urinary calculi, rheumatism, mania, depression, and headache. In 1948, John Cade discovered the anti-manic effects of lithium ions. This finding led lithium, specifically lithium carbonate, to be used to treat mania associated with bipolar disorder. Lithium carbonate is used as a psychiatric medication to treat mania, the elevated phase of bipolar disorder. Prescription lithium carbonate from a pharmacy is suitable for use as medicine in humans while industrial lithium carbonate is not since the latter may, for example, contain unsafe levels of toxic heavy metals or other toxicants. After ingestion, lithium carbonate is dissociated into pharmacologically active lithium ions (Li+) and (non-therapeutic) carbonate, with 300 mg of lithium carbonate containing approximately 8 mEq (8 mmol) of lithium ion. According to the Food and Drug Administration (FDA), 300–600 mg of lithium carbonate taken two to three times daily is typical for maintenance of bipolar I disorder in adults, where the exact dose given varies depending on factors such as the patient's serum lithium concentrations, which must be monitored by a physician to avoid lithium toxicity and potential kidney damage (or even failure) from lithium-induced nephrogenic diabetes insipidus. Lithium ions interfere with ion transport processes (see “sodium pump”) that relay and amplify messages carried to the cells of the brain. Mania is associated with irregular increases in protein kinase C (PKC) activity within the brain. Lithium carbonate and sodium valproate, another drug traditionally used to treat the disorder, act in the brain by inhibiting PKC's activity and help to produce other compounds that also inhibit the PKC. Lithium carbonate's mood-controlling properties are not fully understood. Adverse reactions Taking lithium salts has risks and side effects. Extended use of lithium to treat various mental disorders has been known to lead to acquired nephrogenic diabetes insipidus. Lithium intoxication can affect the central nervous system and renal system and can be lethal. Red pyrotechnic colorant Lithium carbonate is used to impart a red color to fireworks. Properties and reactions Unlike sodium carbonate, which forms at least three hydrates, lithium carbonate exists only in the anhydrous form. Its solubility in water is low relative to other lithium salts. The isolation of lithium from aqueous extracts of lithium ores capitalizes on this poor solubility. Its apparent solubility increases 10-fold under a mild pressure of carbon dioxide; this effect is due to the formation of the metastable bicarbonate, which is more soluble: + + 2 The extraction of lithium carbonate at high pressures of and its precipitation upon depressurizing is the basis of the Quebec process. Lithium carbonate can also be purified by exploiting its diminished solubility in hot water. Thus, heating a saturated aqueous solution causes crystallization of . Lithium carbonate, and other carbonates of group 1, do not decarboxylate readily. decomposes at temperatures around 1300 °C. Production Lithium is extracted from primarily two sources: spodumene in pegmatite deposits, and lithium salts in underground brine pools. About 82,000 tons were produced in 2020, showing significant and consistent growth. From underground brine reservoirs As an example, in the Salar de Atacama in the Atacama desert of Northern Chile, SQM produces lithium carbonate and hydroxide from brine. The process involves pumping up lithium rich brine from below the ground into shallow pans for evaporation. The brine contains many different dissolved ions, and as the concentration increases, salts precipitate out of solution and sink. The remaining liquid (the supernatant) is used for the next step. The exact sequence of pans may vary depending on the concentration of ions in a particular source of brine. In the first pan, halite (sodium chloride or common salt) crystallises. This has insufficient economic value and is discarded. The supernatant, with ever increasing concentration of dissolved solids, is transferred successively to the sylvinite (sodium potassium chloride) pan, the carnalite (potassium magnesium chloride) pan and finally a pan designed to maximise the concentration of lithium chloride. The process takes about 15 months. The concentrate (30-35% lithium chloride solution) is trucked to Salar del Carmen. There, boron and magnesium are removed (typically residual boron is removed by solvent extraction and/or ion exchange and magnesium by raising the pH above 10 with sodium hydroxide) then in the final step, by addition of sodium carbonate, the desired lithium carbonate is precipitated out, separated, and processed. Some of the by-products from the evaporation process may also have economic value. There is considerable focus on the use of water in this water poor region. SQM commissioned a life-cycle analysis which concluded that water consumption for SQM's lithium hydroxide and carbonate is significantly lower than the average consumption in production from the main ore-based process, using spodumene. A more general LCA suggests the opposite for extraction from reservoirs as a whole. The majority of brine based production is in the "lithium triangle" in South America. From 'geothermal' brine Another potential source of lithium is the leachates of geothermal wells, which are carried to the surface. Recovery of lithium has been demonstrated in the field; the lithium is separated by simple precipitation and filtration. The process and environmental costs are primarily those of the already-operating well; net environmental impacts may thus be positive. The brine of United Downs Deep Geothermal Power project near Redruth is claimed by Cornish Lithium to be valuable due to its high lithium concentration (220 mg/l) with low magnesium (<5 mg/l) and total dissolved solids content of <29g/l, and a flow rate of 40-60l/s. From ore α-spodumene is roasted at 1100 °C for 1h to make β-spodumene, then roasted at 250 °C for 10 minutes with sulphuric acid. As of 2020, Australia was the world's largest producer of lithium intermediates, all based on spodumene. In recent years many mining companies have begun exploration of lithium projects throughout North America, South America and Australia to identify economic deposits that can potentially bring new supplies of lithium carbonate online to meet the growing demand for the product. From clay Tesla Motors announced a revolutionary process to extract lithium from clay in Nevada using only salt and no acid. This was met with scepticism. From end of life batteries A few small companies are actively recycling spent batteries, mostly focusing on recovering copper and cobalt. Some do recover lithium also. Other In April 2017 MGX Minerals reported it had received independent confirmation of its rapid lithium extraction process to recover lithium and other valuable minerals from oil and gas wastewater brine. Electrodialysis has been proposed to extract lithium from seawater, but it is not commercially viable. Natural occurrence Natural lithium carbonate is known as zabuyelite. This mineral is connected with deposits of some salt lakes and some pegmatites. References External links Official FDA information published by Drugs.com Carbonates Lithium compounds Mood stabilizers Salts	[ -0.22610390186309814, 0.6777133345603943, -0.48467135429382324, -0.2578350305557251, 0.1544000804424286, 0.1468770056962967, -0.2944047152996063, 0.24491025507450104, 0.31088781356811523, 0.38013190031051636, -0.31101831793785095, 0.22555561363697052, -0.28734833002090454, 0.47387123107910...
18238	https://en.wikipedia.org/wiki/Lunar%20Roving%20Vehicle	Lunar Roving Vehicle	The Lunar Roving Vehicle (LRV) is a battery-powered four-wheeled rover used on the Moon in the last three missions of the American Apollo program (15, 16, and 17) during 1971 and 1972. It is popularly called the Moon buggy, a play on the term dune buggy. Built by Boeing, each LRV has a mass of without payload. It could carry a maximum payload of , including two astronauts, equipment, and lunar samples, and was designed for a top speed of , although it achieved a top speed of on its last mission, Apollo 17. Each LRV was carried to the Moon folded up in the Lunar Module's Quadrant 1 Bay. After being unpacked, each was driven an average of 30 km, without major incident. These three LRVs remain on the Moon. History The concept of a lunar rover predated Apollo, with a 1952–1954 series in Collier's Weekly magazine by Wernher von Braun and others, "Man Will Conquer Space Soon!" In this, von Braun described a six-week stay on the Moon, featuring 10-ton tractor trailers for moving supplies. In 1956, Mieczysław G. Bekker published two books on land locomotion. At the time, Bekker was a University of Michigan professor and a consultant to the U.S. Army Tank-Automotive Command's Land Locomotion Laboratory. The books provided much of the theoretical basis for future lunar vehicle development. Early lunar mobility studies In the February 1964 issue of Popular Science, von Braun, then director of NASA's Marshall Space Flight Center (MSFC), discussed the need for a lunar surface vehicle, and revealed that studies had been underway at Marshall in conjunction with Lockheed, Bendix, Boeing, General Motors, Brown Engineering, Grumman, and Bell Aerospace. Beginning in the early 1960s, a series of studies centering on lunar mobility were conducted under Marshall. This began with the lunar logistics system (LLS), followed by the mobility laboratory (MOLAB), then the lunar scientific survey module (LSSM), and finally the mobility test article (MTA). In early planning for the Apollo program, it had been assumed that two Saturn V launch vehicles would be used for each lunar mission: one for sending the crew aboard a Lunar Surface Module (LSM) to lunar orbit, landing, and returning, and a second for sending an LSM-Truck (LSM-T) with all of the equipment, supplies, and transport vehicle for use by the crew while on the surface. All of the first Marshall studies were based on this dual-launch assumption, allowing a large, heavy, roving vehicle. Grumman and Northrop, in the fall of 1962, began to design pressurized-cabin vehicles, with electric motors for each wheel. At about this same time Bendix and Boeing started their own internal studies on lunar transportation systems. Mieczysław Bekker, now with General Motors Defense Research Laboratories at Santa Barbara, California, was completing a study for NASA's Jet Propulsion Laboratory on a small, uncrewed lunar roving vehicle for the Surveyor program. Ferenc Pavlics, originally from Hungary, used a wire-mesh design for "resilient wheels," a design that would be followed in future small rovers. In early 1963, NASA selected Marshall for studies in an Apollo Logistics Support System (ALSS). Following reviews of all earlier efforts, this resulted in a 10-volume report. Included was the need for a pressurized vehicle in the weight range, accommodating two men with their expendables and instruments for traverses up to two weeks in duration. In June 1964, Marshall awarded contracts to Bendix and to Boeing, with GM's lab designated as the vehicle technology subcontractor. Bell Aerospace was already under contract for studies of Lunar Flying Vehicles. Even as the Bendix and Boeing studies were underway, Marshall was examining a less ambitious surface exploration activity, the LSSM. This would be composed of a fixed, habitable shelter–laboratory with a small lunar-traversing vehicle that could either carry one man or be remotely controlled. This mission would still require a dual launch with the moon vehicle carried on the "lunar truck". Marshall's Propulsion and Vehicle Engineering (P&VE) lab contracted with Hayes International to make a preliminary study of the shelter and its related vehicle. Because of the potential need for an enclosed vehicle for enlarged future lunar explorations, those design efforts continued for some time, and resulted in several full-scale test vehicles. With pressure from Congress to hold down Apollo costs, Saturn V production was reduced, allowing only a single launch per mission. Any roving vehicle would have to fit on the same lunar module as the astronauts. In November 1964, two-rocket models were put on indefinite hold, but Bendix and Boeing were given study contracts for small rovers. The name of the lunar excursion module was changed to simply the lunar module, indicating that the capability for powered "excursions" away from a lunar-lander base did not yet exist. There could be no mobile lab — the astronauts would work out of the LM. Marshall continued to also examine uncrewed robotic rovers that could be controlled from the Earth. From the beginnings at Marshall, the Brown Engineering Company of Huntsville, Alabama, had participated in all of the lunar mobility efforts. In 1965, Brown became the prime support contractor for Marshall's P&VE Laboratory. With an urgent need to determine the feasibility of a two-man self-contained lander, von Braun bypassed the usual procurement process and had P&VE's Advanced Studies Office directly task Brown to design, build, and test a prototype vehicle. While Bendix and Boeing would continue to refine concepts and designs for a lander, test model rovers were vital for Marshall human factors studies involving spacesuit-clad astronauts interfacing with power, telemetry, navigation, and life-support rover equipment. Brown's team made full use of the earlier small-rover studies, and commercially available components were incorporated wherever possible. The selection of wheels was of great importance, and almost nothing was known at that time about the lunar surface. The Marshall Space Sciences Laboratory (SSL) was responsible for predicting surface properties, and Brown was also prime support contractor for this lab; Brown set up a test area to examine a wide variety of wheel-surface conditions. To simulate Pavlics' "resilient wheel," a four-foot-diameter inner tube wrapped with nylon ski rope was used. On the small test rover, each wheel had a small electric motor, with overall power provided by standard truck batteries. A roll bar gave protection from overturn accidents. In early 1966, Brown's vehicle became available for examining human factors and other testing. Marshall built a small test track with craters and rock debris where the several different mock-ups were compared; it became obvious that a small rover would be best for the proposed missions. The test vehicle was also operated in remote mode to determine characteristics that might be dangerous to the driver, such as acceleration, bounce-height, and turn-over tendency as it traveled at higher speeds and over simulated obstacles. The test rover's performance under one-sixth gravity was obtained through flights on a KC-135A aircraft in a Reduced Gravity parabolic maneuver; among other things, the need for a very soft wheel and suspension combination was shown. Although Pavlics' wire-mesh wheels were not initially available for the reduced gravity tests, the mesh wheels were tested on various soils at the Waterways Experiment Station of the U.S. Army Corps of Engineers at Vicksburg, Mississippi. Later, when wire-mesh wheels were tested on low-g flights, the need for wheel fenders to reduce dust contamination was found. The model was also extensively tested at the U.S. Army's Yuma Proving Ground in Arizona, as well as the Army's Aberdeen Proving Ground in Maryland. Lunar Roving Vehicle Project During 1965 and 1967, the Summer Conference on Lunar Exploration and Science brought together leading scientists to assess NASA's planning for exploring the Moon and to make recommendations. One of their findings was that the LSSM was critical to a successful program and should be given major attention. At Marshall, von Braun established a Lunar Roving Task Team, and in May 1969, NASA approved the Manned Lunar Rover Vehicle Program as a Marshall hardware development. Saverio "Sonny" Morea was named Lunar Roving Vehicle Project Manager. On 11 July 1969, just before the successful Moon landing of Apollo 11, a request for proposal for the final development and building the Apollo LRV was released by Marshall. Boeing, Bendix, Grumman, and Chrysler submitted proposals. Following three months of proposal evaluation and negotiations, Boeing was selected as the Apollo LRV prime contractor on 28 October 1969. Boeing would manage the LRV project under Henry Kudish in Huntsville, Alabama. As a major subcontractor, the General Motors' Defense Research Laboratories in Santa Barbara, California, would furnish the mobility system (wheels, motors, and suspension); this effort would be led by GM Program Manager Samuel Romano andFerenc Pavlics. Boeing in Seattle, Washington, would furnish the electronics and navigation system. Vehicle testing would take place at the Boeing facility in Kent, Washington, and the chassis manufacturing and overall assembly would be at the Boeing facility in Huntsville. The first cost-plus-incentive-fee contract to Boeing was for $19,000,000 and called for delivery of the first LRV by 1 April 1971. Cost overruns, however, led to a final cost of $38,000,000, which was about the same as NASA's original estimate. Four lunar rovers were built, one each for Apollo missions 15, 16, and 17; and one used for spare parts after the cancellation of further Apollo missions. Other LRV models were built: a static model to assist with human factors design; an engineering model to design and integrate the subsystems; two one-sixth gravity models for testing the deployment mechanism; a one-gravity trainer to give the astronauts instruction in the operation of the rover and allow them to practice driving it; a mass model to test the effect of the rover on the LM structure, balance, and handling; a vibration test unit to study the LRV's durability and handling of launch stresses; and a qualification test unit to study integration of all LRV subsystems. A paper by Saverio Morea gives details of the LRV system and its development. LRVs were used for greater surface mobility during the Apollo J-class missions, Apollo 15, Apollo 16, and Apollo 17. The rover was first used on 31 July 1971, during the Apollo 15 mission. This greatly expanded the range of the lunar explorers. Previous teams of astronauts were restricted to short walking distances around the landing site due to the bulky space suit equipment required to sustain life in the lunar environment. The range, however, was operationally restricted to remain within walking distance of the lunar module, in case the rover broke down at any point. The rovers were designed with a top speed of about , although Eugene Cernan recorded a maximum speed of , giving him the (unofficial) lunar land-speed record. The LRV was developed in only 17 months and performed all its functions on the Moon with no major anomalies. Scientist-astronaut Harrison Schmitt of Apollo 17 said, "The Lunar Rover proved to be the reliable, safe and flexible lunar exploration vehicle we expected it to be. Without it, the major scientific discoveries of Apollo 15, 16, and 17 would not have been possible; and our current understanding of lunar evolution would not have been possible." The LRVs experienced some minor problems. The rear fender extension on the Apollo 16 LRV was lost during the mission's second extra-vehicular activity (EVA) at station 8 when John Young bumped into it while going to assist Charles Duke. The dust thrown up from the wheel covered the crew, the console, and the communications equipment. High battery temperatures and resulting high power consumption ensued. No repair attempt was mentioned. The fender extension on the Apollo 17 LRV broke when accidentally bumped by Eugene Cernan with a hammer handle. Cernan and Schmitt taped the extension back in place, but due to the dusty surfaces, the tape did not adhere and the extension was lost after about one hour of driving, causing the astronauts to be covered with dust. For their second EVA, a replacement "fender" was made with some EVA maps, duct tape, and a pair of clamps from inside the Lunar Module that were nominally intended for the moveable overhead light. This repair was later undone so that the clamps could be taken inside for the return launch. The maps were brought back to Earth and are now on display at the National Air and Space Museum. The abrasion from the dust is evident on some portions of the makeshift fender. The color TV camera mounted on the front of the LRV could be remotely operated by Mission Control in pan and tilt axes as well as zoom. This allowed far better television coverage of the EVA than the earlier missions. On each mission, at the conclusion of the astronauts' stay on the surface, the commander drove the LRV to a position away from the Lunar Module so that the camera could record the ascent stage launch. The camera operator in Mission Control experienced difficulty in timing the various delays so that the LM ascent stage was in frame through the launch. On the third and final attempt (Apollo 17), the launch and ascent were successfully tracked. NASA's rovers, left behind, are among the artificial objects on the Moon, as are the Soviet Union's uncrewed rovers, Lunokhod 1 and Lunokhod 2. Features and specifications The Apollo Lunar Roving Vehicle was an electric-powered vehicle designed to operate in the low-gravity vacuum of the Moon and to be capable of traversing the lunar surface, allowing the Apollo astronauts to extend the range of their surface extravehicular activities. Three LRVs were used on the Moon: one on Apollo 15 by astronauts David Scott and Jim Irwin, one on Apollo 16 by John Young and Charles Duke, and one on Apollo 17 by Eugene Cernan and Harrison Schmitt. The mission commander served as the driver, occupying the left-hand seat of each LRV. Features are available in papers by Morea, Baker, and Kudish. Mass and payload The Lunar Roving Vehicle had a mass of , and was designed to hold a payload of . This resulted in weights in the approximately one-sixth g on the lunar surface of empty (curb weight) and fully loaded (gross vehicle weight). The frame was long with a wheelbase of . The height of the vehicle was . The frame was made of 2219 aluminium alloy tubing welded assemblies and consisted of a three-part chassis that was hinged in the center so it could be folded up and hung in the Lunar Module Quadrant 1 bay, which was kept open to space by omission of the outer skin panel. It had two side-by-side foldable seats made of tubular aluminium with nylon webbing and aluminum floor panels. An armrest was mounted between the seats, and each seat had adjustable footrests and a Velcro-fastened seat belt. A large mesh dish antenna was mounted on a mast on the front center of the rover. The suspension consisted of a double horizontal wishbone with upper and lower torsion bars and a damper unit between the chassis and upper wishbone. Fully loaded, the LRV had a ground clearance of . Wheels and power The wheels were designed and manufactured by General Motors Defense Research Laboratories in Santa Barbara, California. Ferenc Pavlics was given special recognition by NASA for developing the "resilient wheel". They consisted of a spun aluminum hub and a diameter, wide tire made of zinc-coated woven diameter steel strands attached to the rim and discs of formed aluminum. Titanium chevrons covered 50% of the contact area to provide traction. Inside the tire was a diameter bump stop frame to protect the hub. Dust guards were mounted above the wheels. Each wheel had its own electric drive made by Delco, a direct current (DC) series-wound motor capable of at 10,000 rpm, attached to the wheel via an 80:1 harmonic drive, and a mechanical brake unit. Each wheel could free-wheel in case of drive failure. Maneuvering capability was provided through the use of front and rear steering motors. Each series-wound DC steering motor was capable of . The front and rear wheels could pivot in opposite directions to achieve a tight turning radius of , or could be decoupled so only front or rear would be used for steering. Power was provided by two 36-volt silver-zinc potassium hydroxide non-rechargeable batteries with a charge capacity of 121 A·h each (a total of 242 A·h), yielding a range of . These were used to power the drive and steering motors and also a 36-volt utility outlet mounted on the front of the LRV to power the communications relay unit or the TV camera. LRV batteries and electronics were passively cooled, using change-of-phase wax thermal capacitor packages and reflective, upward-facing radiating surfaces. While driving, radiators were covered with mylar blankets to minimize dust accumulation. When stopped, the astronauts would open the blankets, and manually remove excess dust from the cooling surfaces with hand brushes. Control and navigation A T-shaped hand controller situated between the two seats controlled the four drive motors, two steering motors, and brakes. Moving the stick forward powered the LRV forward, left and right turned the vehicle left or right, and pulling backwards activated the brakes. Activating a switch on the handle before pulling back would put the LRV into reverse. Pulling the handle all the way back activated a parking brake. The control and display modules were situated in front of the handle and gave information on the speed, heading, pitch, and power and temperature levels. Navigation was based on continuously recording direction and distance through use of a directional gyro and odometer and feeding this data to a computer that would keep track of the overall direction and distance back to the LM. There was also a Sun-shadow device that could give a manual heading based on the direction of the Sun, using the fact that the Sun moved very slowly in the sky. Usage The LRV was used during the lunar surface operations of Apollo 15, 16 and 17, the J missions of the Apollo program. On each mission, the LRV was used on three separate EVAs, for a total of nine lunar traverses, or sorties. During operation, the Commander (CDR) always drove, while the Lunar Module Pilot (LMP) was a passenger who assisted with navigation. An operational constraint on the use of the LRV was that the astronauts must be able to walk back to the LM if the LRV were to fail at any time during the EVA (called the "Walkback Limit"). Thus, the traverses were limited in the distance they could go at the start and at any time later in the EVA. Therefore, they went to the farthest point away from the LM and worked their way back to it so that, as the life support consumables were depleted, their remaining walk back distance was equally diminished. This constraint was relaxed during the longest traverse on Apollo 17, based on the demonstrated reliability of the LRV and spacesuits on previous missions. A paper by Burkhalter and Sharp provides details on usage. Deployment Astronaut deployment of the LRV from the LM's open Quadrant 1 bay was achieved with a system of pulleys and braked reels using ropes and cloth tapes. The rover was folded and stored in the bay with the underside of the chassis facing out. One astronaut would climb the egress ladder on the LM and release the rover, which would then be slowly tilted out by the second astronaut on the ground through the use of reels and tapes. As the rover was let down from the bay, most of the deployment was automatic. The rear wheels folded out and locked in place. When they touched the ground, the front of the rover could be unfolded, the wheels deployed, and the entire frame let down to the surface by pulleys. The rover components locked into place upon opening. Cabling, pins, and tripods would then be removed and the seats and footrests raised. After switching on all the electronics, the vehicle was ready to back away from the LM. Locations Four flight-ready LRVs were manufactured, as well as several others for testing and training. Three were transported to and left on the Moon via the Apollo 15, 16, and 17 missions, with the fourth rover used for spare parts on the first three following the cancellation of Apollo 18. Since only the upper stages of the lunar excursion modules could return to lunar orbit from the surface, the vehicles, along with the lower stages were abandoned. As a result, the only lunar rovers on display are test vehicles, trainers, and mock-ups. The rover used on Apollo 15 was left at Hadley-Apennine ( ). The rover used on Apollo 16 was left at Descartes ( ). The rover used on Apollo 17 was left at Taurus-Littrow ( ) and was seen by the Lunar Reconnaissance Orbiter during passes in 2009 and 2011. In 2020 the State of Washington designated the flown rovers as historic landmarks. Several rovers were created for testing, training, or validation purposes. The engineering mockup is on display at the Museum of Flight in Seattle, Washington. The Qualification Test Unit is on display at the National Air and Space Museum in Washington, D.C. The rover used for vibration testing is on display in the Davidson Saturn V Center at the U.S. Space & Rocket Center in Huntsville, Alabama. Additional test units are on display at the Johnson Space Center in Houston, Texas, and the Kennedy Space Center Visitors Complex in Cape Canaveral, Florida. Replicas of rovers are on display at the National Museum of Naval Aviation in Pensacola, Florida, the Evergreen Aviation & Space Museum in McMinnville, Oregon, and the Kansas Cosmosphere and Space Center in Hutchinson, Kansas. A replica on loan from the Smithsonian Institution is on display at the Mission: Space attraction at Epcot at the Walt Disney World Resort near Orlando, Florida. Media See also List of artificial objects on the Moon Lunar Terrain Vehicle Modular Equipment Transporter References External links Boeing Lunar Rover Vehicle Operations Handbook Article about the rover LRV Operations Handbook, Appendix A (Performance Data) Mobility Performance of the Lunar Roving Vehicle: Terrestrial Studies – Apollo 15 Results Lunar Rover in Operation Video Lunar and Planetary Rovers: The Wheels of Apollo and the Quest for Mars Apollo Lunar Roving Vehicle Documentation – Apollo Lunar Surface Journal Lunar Roving Vehicle at the Smithsonian National Air and Space Museum Lunar Roving Vehicle Collection, The University of Alabama in Huntsville Archives and Special Collections Ronald Lancaster Collection, The University of Alabama in Huntsville Archives and Special Collections Engineer's collection of photos and documents on the design and construction of the LRV. Exploration of the Moon Apollo program hardware Missions to the Moon Lunar rovers Electric cars All-wheel-drive vehicles NASA vehicles Articles containing video clips Apollo 15 Apollo 16 Apollo 17 Off-road vehicles 1971 on the Moon 1972 on the Moon	[ -0.4230532646179199, 0.4342488646507263, 0.5944016575813293, 0.17519909143447876, 0.07357823103666306, 0.17417177557945251, -0.3518024981021881, 0.08184517920017242, -0.39912161231040955, 0.21310639381408691, -0.19314320385456085, 0.6445522308349609, 0.11408326774835587, -0.076962999999523...
18240	https://en.wikipedia.org/wiki/Lake%20Kickapoo	Lake Kickapoo	Lake Kickapoo is a reservoir in Archer County, Texas. Created in 1947. It has a surface area of . Named after the Kickapoo tribe native to the area. One of the nine Air Force Space Surveillance System (formerly NAVSPASUR) sites is located at Lake Kickapoo (). It is the master transmitter and the most powerful continuous wave (CW) station in the world, at 768 kW radiated power. External links Protected areas of Archer County, Texas Kickapoo 1947 establishments in Texas Protected areas established in 1947 Bodies of water of Archer County, Texas	[ -0.33300694823265076, 0.54469895362854, -0.17078039050102234, 0.2820570468902588, -0.10336354374885559, -0.31740623712539673, 0.9695603847503662, 0.48028239607810974, 0.5343063473701477, -0.09113398939371109, -0.3769351541996002, -0.20110206305980682, -1.0531857013702393, 0.672781050205230...
18243	https://en.wikipedia.org/wiki/Land%20%28disambiguation%29	Land (disambiguation)	Land is the solid surface of the Earth that is not covered by water. Land, lands, The Land or the Lands may also refer to: Entertainment and media Film Land (1987 film), a British television film by Barry Collins Land (2018 film), an international drama by Babak Jalali Land (2021 film), a drama directed by and starring Robin Wright Music Dah (band), a former Yugoslav/Belgian rock band, known as Land during 1975-1976 period Land (1975–2002), an album by Patti Smith Land (band), an American rock band Land (Land album), 1995 Land (worship band), a Scottish Christian band Land (The Comsat Angels album), 1983 Land (Týr album), 2008 Lands (band), a Japanese rock band Other media Land (book), a 2021 non-fiction book by Simon Winchester Land (magazine), a Swedish weekly magazine The Land (weekly newspaper) Places Land Glacier, Antarctica Land, Norway The Lands, common name for Anangu Pitjantjatjara Yankunytjatjara, or APY Lands, in South Australia Division of a country Länder of Austria (singular: Land), the states of Austria Länder of Germany , the states of Germany (singular: Land) Lands of Denmark Lands of Finland Lands of Norway Lands of Sweden Other uses -land, a suffix used in the names of several countries and other regions LAND, a type of denial-of-service attack Land (economics), a factor of production comprising all naturally occurring resources Land (surname) Landing, the end of a flight Land Tawney, an American conservationist In rifling, lands are the raised areas between grooves in gun barrels See also Land Instruments International, a company specialising in temperature monitoring equipment Land law	[ 0.21297572553157806, 0.20950588583946228, -0.11866766959428787, 0.23056352138519287, -0.06951498985290527, -0.10938724130392075, 0.25355806946754456, 0.1957961916923523, -0.15522781014442444, -0.6732562780380249, -0.24633900821208954, 0.24375499784946442, 0.05359138920903206, 0.58136427402...
18245	https://en.wikipedia.org/wiki/Labyrinth	Labyrinth	In Greek mythology, the Labyrinth (, ) was an elaborate, confusing structure designed and built by the legendary artificer Daedalus for King Minos of Crete at Knossos. Its function was to hold the Minotaur, the monster eventually killed by the hero Theseus. Daedalus had so cunningly made the Labyrinth that he could barely escape it after he built it. Although early Cretan coins occasionally exhibit branching (multicursal) patterns, the single-path (unicursal) seven-course "Classical" design without branching or dead ends became associated with the Labyrinth on coins as early as 430 BC, and similar non-branching patterns became widely used as visual representations of the Labyrinth – even though both logic and literary descriptions make it clear that the Minotaur was trapped in a complex branching maze. Even as the designs became more elaborate, visual depictions of the mythological Labyrinth from Roman times until the Renaissance are almost invariably unicursal. Branching mazes were reintroduced only when hedge mazes became popular during the Renaissance. In English, the term labyrinth is generally synonymous with maze. As a result of the long history of unicursal representation of the mythological Labyrinth, however, many contemporary scholars and enthusiasts observe a distinction between the two. In this specialized usage maze refers to a complex branching multicursal puzzle with choices of path and direction, while a unicursal labyrinth has only a single path to the center. A labyrinth in this sense has an unambiguous route to the center and back and presents no navigational challenge. Unicursal labyrinths appeared as designs on pottery or basketry, as body art, and in etchings on walls of caves or churches. The Romans created many primarily decorative unicursal designs on walls and floors in tile or mosaic. Many labyrinths set in floors or on the ground are large enough that the path can be walked. Unicursal patterns have been used historically both in group ritual and for private meditation, and are increasingly found for therapeutic use in hospitals and hospices. Etymology Labyrinth is a word of pre-Greek origin whose derivation and meaning are uncertain. Maximillian Mayer suggested as early as 1892 that labyrinthos might derive from labrys, a Lydian word for "double-bladed axe". Arthur Evans, who excavated the palace of Knossos in Crete early in the 20th century, suggested that the palace was the original labyrinth, and since the double axe motif appears in the palace ruins, he asserted that labyrinth could be understood to mean "the house of the double axe". The same symbol, however, was discovered in other palaces in Crete. Nilsson observed that in Crete the double axe is not a weapon and always accompanies goddesses or women and not a male god. The association with "labrys" lost some traction when Linear B was deciphered in the 1950s, and the Mycenaean Greek version of "labyrinth" appeared as (). This may be related to the Minoan word du-bu-re or du-pu2-re, which appears in Linear A on libation tablets and in connection with Mts Dikte and Ida, both of which are associated with caverns. Caverns near Gortyna, the Cretan capital in the 1st century AD, were called labyrinthos. Pliny's Natural History gives four examples of ancient labyrinths: the Cretan labyrinth, an Egyptian labyrinth, a Lemnian labyrinth, and an Italian labyrinth. These are all complex underground structures, and this appears to have been the standard Classical understanding of the word. Beekes also finds the relation with labrys speculative, and suggests instead a relation with Greek ('narrow street'). The goddess of the double-axe probably presided over the Minoan palaces, and especially over the palace of Knossos. The Linear B (Mycenaean) inscription on tablet ΚΝ Gg 702, is interpreted as da-pu2-ri-to-jo,po-ti-ni-ja (labyrinthoio potnia, "Mistress of the labyrinth), and she was undoubtedly the goddess of the palace. The word daburinthos (labyrinthos) may possibly show the same equivocation between initial d- and l- as is found in the variation of the early Hittite royal name Tabarna / Labarna (where written t- may represent phonetic d-). Ancient labyrinths Cretan labyrinth When the Bronze Age site at Knossos was excavated by explorer Arthur Evans, the complexity of the architecture prompted him to suggest that the palace had been the Labyrinth of Daedalus. Evans found various bull motifs, including an image of a man leaping over the horns of a bull, as well as depictions of a labrys carved into the walls. On the strength of a passage in the Iliad, it has been suggested that the palace was the site of a dancing-ground made for Ariadne by the craftsman Daedalus, where young men and women, of the age of those sent to Crete as prey for the Minotaur, would dance together. By extension, in popular legend the palace is associated with the myth of the Minotaur. In the 2000s, archaeologists explored other potential sites of the labyrinth. Oxford University geographer Nicholas Howarth believes that "Evans's hypothesis that the palace of Knossos is also the Labyrinth must be treated sceptically." Howarth and his team conducted a search of an underground complex known as the Skotino cave but concluded that it was formed naturally. Another contender is a series of tunnels at Gortyn, accessed by a narrow crack but expanding into interlinking caverns. Unlike the Skotino cave, these caverns have smooth walls and columns, and appear to have been at least partially man-made. This site corresponds to a labyrinth symbol on a 16th-century map of Crete in a book of maps in the library of Christ Church, Oxford. A map of the caves themselves was produced by the French in 1821. The site was also used by German soldiers to store ammunition during the Second World War. Howarth's investigation was shown on a documentary produced for the National Geographic Channel. The Egyptian labyrinth More generally, labyrinth might be applied to any extremely complicated maze-like structure. In Book II of his Histories, Herodotus applies the term "labyrinth" to a building complex in Egypt "near the place called the City of Crocodiles", that he considered to surpass the pyramids: During the nineteenth century, the remains of this ancient Egyptian structure were discovered at Hawara in the Faiyum Oasis by Flinders Petrie at the foot of the pyramid of the twelfth-dynasty pharaoh Amenemhat III (reigned c. 1860 BC to c. 1814 BC). The Classical accounts of various authors (Herodotus, Strabo, Pliny the Elder, among others) are not entirely consistent, perhaps due to degradation of the structure during Classical times. The structure may have been a collection of funerary temples such as are commonly found near Egyptian pyramids. Records indicate that Amenemhat's daughter Sobekneferu made additions to the complex during her reign as king of Egypt. In 1898, the Harpers Dictionary of Classical Antiquities described the structure as "the largest of all the temples of Egypt, the so-called Labyrinth, of which, however, only the foundation stones have been preserved." Herodotus' description of the Egyptian Labyrinth inspired some central scenes in Bolesław Prus' 1895 historical novel, Pharaoh. Pliny's Lemnian labyrinth Pliny the Elder's Natural History (36.90) lists the legendary Smilis, reputed to be a contemporary of Daedalus, together with the historical mid-sixth-century BC architects and sculptors Rhoikos and Theodoros as two of the makers of the Lemnian labyrinth, which Andrew Stewart regards as "evidently a misunderstanding of the Samian temple's location en limnais ['in the marsh']." Pliny's Italian labyrinth According to Pliny, the tomb of the great Etruscan general Lars Porsena contained an underground maze. Pliny's description of the exposed portion of the tomb is intractable; Pliny, it seems clear, had not observed this structure himself, but is quoting the historian and Roman antiquarian Varro. Ancient labyrinths outside Europe A design essentially identical to the 7-course "classical" pattern appeared in Native American culture, the Tohono O'odham people labyrinth which features I'itoi, the "Man in the Maze." The Tonoho O'odham pattern has two distinct differences from the classical: it is radial in design, and the entrance is at the top, where traditional labyrinths have the entrance at the bottom (see below). The earliest appearances cannot be dated securely; the oldest is commonly dated to the 17th century. Unsubstantiated claims have been made for the early appearance of labyrinth figures in India, such as a prehistoric petroglyph on a riverbank in Goa purportedly dating to circa 2500 BC. Other examples have been found among cave art in northern India and on a dolmen shrine in the Nilgiri Mountains, but are difficult to date accurately. Securely datable examples begin to appear only around 250 BC. Early labyrinths in India typically follow the Classical pattern or a local variant of it; some have been described as plans of forts or cities. Labyrinths appear in Indian manuscripts and Tantric texts from the 17th century onward. They are often called "Chakravyuha" in reference to an impregnable battle formation described in the ancient Mahabharata epic. Lanka, the capital city of mythic Rāvana, is described as a labyrinth in the 1910 translation of Al-Beruni's India (c. 1030 AD) p. 306 (with a diagram on the following page). By the White Sea, notably on the Solovetsky Islands, there have been preserved more than 30 stone labyrinths. The most remarkable monument is the Stone labyrinths of Bolshoi Zayatsky Island – a group of some 13 stone labyrinths on 0.4 km2 area of one small island. Local archaeologists have speculated that these labyrinths may be 2,000–3,000 years old, though most researchers remain dubious. Labyrinth as pattern The 7-course "Classical" or "Cretan" pattern known from Cretan coins (ca 400–200 BC) appears in several examples from antiquity, some perhaps as early as the late Stone Age or early Bronze Age. Roman floor mosaics typically unite four copies of the classical labyrinth (or a similar pattern) interlinked around the center, squared off as the medium requires, but still recognisable. An image of the Minotaur or an allusion to the legend of the Minotaur appears at the center of many of these mosaic labyrinths. The four-axis medieval patterns may have developed from the Roman model, but are more varied in how the four quadrants of the design are traced out. The Minotaur or other danger is retained in the center of several medieval examples. The Chartres pattern (named for its appearance in Chartres Cathedral) is the most common medieval design; it appears in manuscripts as early as the 9th century. Medieval labyrinths and turf mazes When the early humanist Benzo d'Alessandria visited Verona before 1310, he noted the "Laberinthum which is now called the Arena"; perhaps he was seeing the cubiculi beneath the arena's missing floor. The full flowering of the medieval labyrinth came about from the twelfth through fourteenth centuries with the grand pavement labyrinths of the gothic cathedrals, notably Chartres, Reims and Amiens in northern France. The symbolism or purpose behind these is unclear, and may have varied from one installation to the next. Descriptions survive of French clerics performing a ritual Easter dance along the path on Easter Sunday. Some labyrinths may have originated as allusions to the Holy City; and some modern writers have theorized that prayers and devotions may have accompanied the perambulation of their intricate paths. Although some books (in particular guidebooks) suggest that the mazes on cathedral floors served as substitutes for pilgrimage paths, the earliest attested use of the phrase "chemin de Jerusalem" (path to Jerusalem) dates to the late 18th century when it was used to describe mazes at Reims and Saint-Omer. The accompanying ritual, depicted in Romantic illustrations as involving pilgrims following the maze on their knees while praying, may have been practiced at Chartres during the 17th century. The cathedral labyrinths are thought to be the inspiration for the many turf mazes in the UK, such as survive at Wing, Hilton, Alkborough, and Saffron Walden. Over the same general period, some 500 or more non-ecclesiastical labyrinths were constructed in Scandinavia. These labyrinths, generally in coastal areas, are marked out with stones, most often in the simple 7- or 11-course classical forms. They often have names which translate as "Troy Town." They are thought to have been constructed by fishing communities: trapping malevolent trolls or winds in the labyrinth's coils might ensure a safe fishing expedition. There are also stone labyrinths on the Isles of Scilly, although none is known to date from before the nineteenth century. There are examples of labyrinths in many disparate cultures. The symbol has appeared in various forms and media (petroglyphs, classic-form, medieval-form, pavement, turf, and basketry) at some time throughout most parts of the world, from Native North and South America to Australia, Java, India, and Nepal. Modern labyrinths In recent years, there has been a resurgence of interest in labyrinths and a revival in labyrinth building, of both unicursal and multicursal patterns. Approximately 6,000 labyrinths have been registered with the Worldwide Labyrinth Locator; these are located around the world in private properties, libraries, schools, gardens, recreational areas, as well as famous temples and cathedrals. The labyrinth is also treated in contemporary fine arts. Examples include Piet Mondrian's Pier and Ocean (1915), Joan Miró's Labyrinth (1923), Pablo Picasso's Minotauromachy (1935), M. C. Escher's Relativity (1953), Friedensreich Hundertwasser's Labyrinth (1957), Jean Dubuffet's Logological Cabinet (1970), Richard Long's Connemara sculpture (1971), Joe Tilson's Earth Maze (1975), Richard Fleischner's Chain Link Maze (1978), István Orosz's Atlantis Anamorphosis (2000), Dmitry Rakov's Labyrinth (2003), and drawings by contemporary American artist Mo Morales employing what the artist calls "Labyrinthine projection." The Italian painter Davide Tonato has dedicated many of his artistic works to the labyrinth theme. In modern imagery, the labyrinth of Daedalus is often represented by a multicursal maze, in which one may become lost. Mark Wallinger has created a set of 270 enamel plaques of unicursal labyrinth designs, one for every tube station in the London Underground, to mark the 150th anniversary of the Underground. The plaques were installed over a 16-month period in 2013 and 2014, and each is numbered according to its position in the route taken by the contestants in the 2009 Guinness World Record Tube Challenge. Cultural meanings Prehistoric labyrinths may have served as traps for malevolent spirits or as paths for ritual dances. Many Roman and Christian labyrinths appear at the entrances of buildings, suggesting that they may have served a similar apotropaic purpose. In their cross-cultural study of signs and symbols, Patterns that Connect, Carl Schuster and Edmund Carpenter present various forms of the labyrinth and suggest various possible meanings, including not only a sacred path to the home of a sacred ancestor, but also, perhaps, a representation of the ancestor him/herself: ."..many [New World] Indians who make the labyrinth regard it as a sacred symbol, a beneficial ancestor, a deity. In this they may be preserving its original meaning: the ultimate ancestor, here evoked by two continuous lines joining its twelve primary joints." Schuster also observes the common theme of the labyrinth being a refuge for a trickster; in India, the demon Ravana has dominion over labyrinths, the trickster Djonaha lives in a labyrinth according to Sumatran Bataks, and Europeans say it is the home of a rogue. One can think of labyrinths as symbolic of pilgrimage; people can walk the path, ascending toward salvation or enlightenment. Author Ben Radford conducted an investigation into some of the claims of spiritual and healing effects of labyrinths, reporting on his findings in his book Mysterious New Mexico. Many labyrinths have been constructed recently in churches, hospitals, and parks. These are often used for contemplation; walking among the turnings, one loses track of direction and of the outside world, and thus quiets the mind. Christian use Labyrinths have on various occasions been used in Christian tradition as a part of worship. The earliest known example is from a fourth-century pavement at the Basilica of St Reparatus, at Orleansville, Algeria, with the words "Sancta Eclesia" at the center, though it is unclear how it might have been used in worship. In medieval times, labyrinths began to appear on church walls and floors around 1000 AD. The most famous medieval labyrinth, with great influence on later practice, was created in Chartres Cathedral. The use of labyrinths has recently been revived in some contexts of Christian worship. Many churches in Europe and North America have constructed permanent, typically unicursal, labyrinths, or employ temporary ones (e.g., painted on canvas or outlined with candles). For example, a labyrinth was set up on the floor of St Paul's Cathedral for a week in March 2000. Some conservative Christians disapprove of labyrinths, considering them pagan practices or "new age" fads. Mass Media Labyrinths and mazes have been embraced by the video game industry, and countless video games include such a feature. A number of film, game, and music creations feature labyrinths. For instance, the avant-garde multi-screen film, In the Labyrinth, presents a search for meaning in a symbolic modern labyrinth. The well-received 2006 film Pan's Labyrinth draws heavily upon labyrinth legend for symbolism. A magical labyrinth appears in the third episode "And The Horns of a Dilemma" of The Librarians. Please see Labyrinth (disambiguation) for a further list of titles. The Argentine writer Jorge Luis Borges was entranced with the idea of the labyrinth, and used it extensively in his short stories (such as "The House of Asterion" in The Aleph). His use of it has inspired other authors (e.g. Umberto Eco's The Name of the Rose, Mark Z. Danielewski's House of Leaves). Additionally, Roger Zelazny's fantasy series, The Chronicles of Amber, features a labyrinth, called "the Pattern," which grants those who walk it the power to move between parallel worlds. In Rick Riordan's series Percy Jackson & the Olympians, the events of the fourth novel The Battle of the Labyrinth predominantly take place within the labyrinth of Daedalus, which has followed the heart of the West to settle beneath the United States. Australian author Sara Douglass incorporated some labyrinthine ideas in her series The Troy Game, in which the Labyrinth on Crete is one of several in the ancient world, created with the cities as a source of magical power. Lawrence Durrell's The Dark Labyrinth depicts travelers trapped underground in Crete. Because a labyrinth can serve as a metaphor for situations that are difficult to be extricated from, Octavio Paz titled his book on Mexican identity The Labyrinth of Solitude, describing the Mexican condition as orphaned and lost. See also Caerdroia Celtic maze I'itoi Julian's Bower Mizmaze Oxkintok Notes References Hermann Kern, Through the Labyrinth, ed. Robert Ferré and Jeff Saward, Prestel, 2000, . (This is an English translation of Kern's original German monograph Labyrinthe published by Prestel in 1982.) Lauren Artress, Walking a Sacred Path: Rediscovering the Labyrinth as a Spiritual Practice, Penguin Books, 1995, . Lauren Artress, The Sacred Path Companion: A Guide to Walking the Labyrinth to Heal and Transform, Penguin Books, 2006, . Herodotus, The Histories, Newly translated and with an introduction by Aubrey de Sélincourt, Harmondsworth, England, Penguin Books, 1965. Karl Kerenyi, Dionysos: Archetypal Image of Indestructible Life, Princeton University Press, 1976. Helmut Jaskolski, The Labyrinth: Symbol of Fear, Rebirth and Liberation, Shambala, 1997. Adrian Fisher & Georg Gerster, The Art of the Maze, Weidenfeld & Nicolson, 1990. . Jeff Saward, Labyrinths and Mazes, Gaia Books Ltd, 2003, . Jeff Saward, Magical Paths, Mitchell Beazley, 2002, . W. H. Matthews, Mazes and Labyrinths: Their History and Development, Longmans, Green & Co., 1922. Includes bibliography. Dover Publications reprint, 1970, . Andrew Stewart, One Hundred Greek Sculptors: Their Careers and Extant Works. Henning Eichberg, "Racing in the labyrinth? About some inner contradictions of running." In: Athletics, Society & Identity. Imeros, Journal for Culture and Technology, 5 (2005): 1. Athen: Foundation of the Hellenic World, 169-192. Edward Hays, The Lenten Labyrinth: Daily Reflections for the Journey of Lent, Forest of Peace Publishing, 1994. Carl Schuster and Edmund Carpenter, Patterns that Connect: Social Symbolism in Ancient & Tribal Art, Harry N. Abrams, NY, 1996. Ettore Selli, Labirinti Vegetali, la guida completa alle architetture verdi dei cinque continenti, Ed. Pendragon, 2020; ISBN 9788833642222 External links The Labyrinth Society World-Wide Labyrinth Locator, an international directory Veriditas – Spiritual labyrinth organization founded by Lauren Artress. Sunysb.edu, Through Mazes to Mathematics, Exposition by Tony Phillips Astrolog.org, Maze classification, Extensive classification of labyrinths and algorithms to solve them. Irrgartenwelt.de, Lars O. Heintel's collection of handdrawn labyrinths and mazes Begehbare-labyrinthe.de Website with diagrams and photos of virtually all the public labyrinths in Germany. Mymaze.de, German website and Mymaze.de with descriptions, animations, links, and especially photos of (mostly European) labyrinths. Indigogroup.co.uk, British turf labyrinths by Marilyn Clark. Photos and descriptions of the surviving historical turf mazes in Britain. Gwydir.demon.co.uk, Jo Edkins's Maze Page, an early website providing a clear overview of the territory and suggestions for further study. Gottesformel.ch, "Die Kretische Labyrinth-Höhle" by Thomas M. Waldmann, rev. 2009 . Description of a labyrinthine artificial cave system near Gortyn, Crete, widely considered the original labyrinth on Crete. Spiralzoom.com an educational website about the science of pattern formation, spirals in nature, and spirals in the mythic imagination & labyrinths. Sanu.ac.rs, "The Geometry of History," Tessa Morrison, University of Newcastle, Australia. An attempt to extend Phillips's topological classification to more general unicursal labyrinths. Labyrinth of Egypt – Archaeological site reconstruction and 3D diagrams based on the writings of Herodotus and Strabo. Report of expedition to Hawara in 2008 in search of the lost Egyptian Labyrinth of Herodotus. Video and annotation on labyrinths Puzzles Mazes Rituals Garden features Locations in Greek mythology History of Crete Land art Knossos	[ 0.20188747346401215, 0.24123498797416687, -0.7397311329841614, 0.47738099098205566, 0.9498428106307983, 1.0559473037719727, 0.36983534693717957, 0.2881227135658264, -0.5529006123542786, -0.2369435578584671, -0.20166142284870148, -0.09656719118356705, -0.5789833068847656, 0.3990157246589660...
18246	https://en.wikipedia.org/wiki/Lyon%20%26%20Healy	Lyon & Healy	Lyon & Healy Harps, Inc. is an American musical instrument manufacturer based in Chicago, Illinois and is a subsidiary of Salvi Harps. Today best known for concert harps, the company's Chicago headquarters and manufacturing facility contains a showroom and concert hall. George W. Lyon and Patrick J. Healy began the company in 1864 as a sheet music shop. By the end of the 19th century, they manufactured a wide range of musical instruments—including not only harps, but pianos, guitars, mandolins, banjos, ukuleles and various brass and other percussion instruments. Today, Lyon & Healy harps are widely played by professional musicians, since they are one of the few makers of harps for orchestral use—which are known as concert harps or pedal harps. Lyon & Healy also makes smaller folk harps or lever harps (based on traditional Irish and Scottish instruments) that use levers to change string pitch instead of pedals. In the 1980s, Lyon & Healy also began to manufacture electroacoustic harps and, later, solid body electric harps. History George W. Lyon, a native of Northborough, Massachusetts; and Patrick J. Healy, born in Mallow, Ireland, founded the company in 1864, after they moved from Boston to start a sheet music shop for music publisher Oliver Ditson. Determining Lyon & Healy's history is complicated because its building and company records were destroyed in two fires, including the Great Chicago Fire of 1871. Two smaller fires did little damage to the firm and did not result in data loss. Company letters and trade catalogs don't provide exact dates that would reveal when Lyon & Healy began manufacturing instruments. An article in the Musical Courier states that Lyon & Healy began manufacturing instruments in 1885. Clearly, Lyon & Healy was making fretted string instruments in the 1880s, with Washburn (guitars, mandolins, banjos, and zithers) as their premier line. By the 1900s, if not earlier, Lyon & Healy might well have been manufacturing bowed string instruments. According to Vintage Guitar magazine, "Circa 1900, the firm was so large it manufactured under a host of sub-brands; Washburn is perhaps the most recognized, though Leland, Lakeside, and American Conservatory are still seen." Lyon & Healy also made various percussion instruments. Later, Lyon & Healy began manufacturing brass instruments, possibly as early as the 1890s. Lyon & Healy also repaired instruments, and offered engraving services. Complicating matters still further, Lyon & Healy engraved instruments that it retailed but did not actually manufacture. In its 1892 catalog, it claimed that it manufactured 100,000 instruments annually. For a period of time, 1876 to the Great Depression, the "Golden Age" of piano making, the company hand made pianos and reed organs in addition to harps. Like their harps, Lyon & Healy put the highest quality and craftsmanship in building these instruments. In addition to making grand pianos, George W. Lyon patented his cottage upright in 1878. Its top-of-the-line pianos were sold under the Lyon & Healy name. Their pianos have been described as being remarkably powerful, clear, and having a singing tone. Some have compared the Lyon & Healy grand pianos to other high end brands of the time such as Steinway & Sons, Wm. Knabe & Co., and Sohmer. Lower cost pianos were sold by Lyon & Healy under various other brand names. Like most other Golden Age piano companies, they stopped making pianos during the Great Depression. Lyon retired in 1889 and Healy became the company's first president. That year, Lyon & Healy built their first harp. Healy wanted to develop a harp better suited to the rigors of the American climate than available European models. They successfully produced a harp notable for its strength, pitch reliability, and freedom from unwanted vibration. Previously, most harps in North America were made by small groups of craftsmen in France, England, Ireland, or Italy. In 1890, Lyon & Healy introduced the Style 23 Harp, still a popular and recognizable design. It has 47 strings, highly decorative floral carving on the top of the column, base, and feet, and a fleur de lis pattern at the bottom of the column. It is available in a gold version. It is tall, and weighs about . Lyon & Healy produces one of the most ornate and elaborate harps in the world, the Louis XV, which includes carvings of leaves, flowers, scrolls, and shells along its neck and kneeblock, as well the soundboard edges. Lyon would later form a new company with E.A. Potter called Lyon & Potter, and remained there until his death on January 12, 1894. Healy died of pneumonia on April 3, 1905. In the 1890s the company—which used the slogan,"Everything in music"—began building pipe organs. In 1894 Robert J. Bennett came to Lyon & Healy from the Hutchings company of Boston to head their organ department. The largest surviving Lyon & Healy pipe organ is at the Our Lady of Sorrows Basilica in Chicago. It is a large organ of four manuals and 57 ranks of pipes. They also made small pipe organs. An example survives at St. Mary's Catholic Church in Aspen Colorado. It is a two manual tracker with a 30 note straight pedalboard and 7 ranks. It is believed to have been built around 1900, and can still be pumped by hand. By the 1900s, Lyon & Healy was one of the largest music publishers in the world, and was a major producer of musical instruments. However, In late 1920s, Lyon & Healy sold its brass musical instrument manufacturing branch (see "New Langwill Index"). In the 1970s, the firm concentrated solely upon making and selling harps. In 1928, Lyon & Healy introduced one of the most unusual harps ever mass-produced, the Salzedo Model. The company designed it in collaboration with the harpist Carlos Salzedo. It an Art Deco style instrument that incorporates bold red and white lines on the soundboard to create a stylized and distinct appearance. In the 1960s, Lyon & Healy introduced a smaller lever harp, the Troubadour, a 36-string harp for young beginners with smaller hands, and for casual players. This harp stands , and weighs . In the late 1970s, Steinway & Sons (then owned by CBS) purchased Lyon & Healy and soon after closed all retail stores, which sold sheet music and musical instruments, to focus on harp production. By 1985, Lyon & Healy also made folk harps, also known as Irish harps, which are even smaller than the Troubadour. The "Shamrock model folk harp" has 34 strings. It stands tall with its legs. The legs can be removed so the player can hold the instrument lap—style on the knees. It weighs about . It features Celtic designs on the soundboard. An Irish or folk harp player is sometimes called a harper rather than harpist. DePaul University now owns the Wabash building. Lyon & Healy harps are still in Chicago, Illinois, at 168 North Ogden Avenue. The building was once home to the recording studios of Orlando R. Marsh. Craftsmanship Wood in harp construction varies by instrument, but Sitka Spruce (Picea sitchensis) is the most common soundboard wood. Various Lyon & Healy guitars, mandolins, and many other instrument types reside in major musical instrument museums in the U.S. and Europe. Lyon and Healy now primarily manufactures four types of harps—the lever harp, petite pedal harp, semi-grande pedal harp, and concert grand harp. They also make limited numbers of special harps called concert grands. Lyon & Healy makes electric lever harps in nontraditional colors such as pink, green, blue, and red. Lyon & Healy Corporation Lyon & Healy Corporation is a musical product distribution company in North America representing brands such as Delta, Relish Guitars, SIM1, Paoletti Guitars and Acus Sound Engineering. Lyon & Healy Corporation aims to become the leading provider of premium quality musical instruments and accessories. See also Washburn Guitars List of Stradivarius instruments Notes External links Official website for Lyon & Healy Musical instrument manufacturing companies based in Chicago Harp makers Former CBS Corporation subsidiaries Companies established in 1864	[ 0.49287116527557373, 0.420302152633667, -0.14121408760547638, -0.5252059102058411, -0.2697087228298187, 0.4692891836166382, 0.050467442721128464, -0.15473462641239166, -0.3038623332977295, -0.14556807279586792, -0.16307881474494934, 0.0792468711733818, -0.1674596220254898, 0.37311351299285...
18247	https://en.wikipedia.org/wiki/Index%20of%20philosophy%20articles%20%28A%E2%80%93C%29	Index of philosophy articles (A–C)	',-," 'Pataphysics" theory of conservatism Mahesh sonavane 0–9 14th Dalai Lama 16 Questions on the Assassination 1649 in philosophy 1658 in philosophy 17th-century philosophy 18th-century philosophy 1919 United States anarchist bombings 1922 in philosophy 1926 in philosophy 1962 in philosophy 1972 in philosophy 1973 in philosophy 1974 in philosophy 1975 in philosophy 1976 in philosophy 1977 in philosophy 1978 in philosophy 1979 in philosophy 1980 in philosophy 19th-century philosophy 20th-century philosophy 20th-century Western painting 2150 AD A A-series and B-series A Buyer's Market A Calendar of Wisdom A Conflict of Visions A Contribution to the Critique of Political Economy A Defence of Common Sense A Defense of Abortion A Dissertation on Liberty and Necessity, Pleasure and Pain A Few Words on Non-Intervention A Fórmula de Deus A fortiori argument A General View of Positivism A Grief Observed A Guide for the Perplexed A Happy Death A History of God A History of Murphy's Law A History of Philosophy (Copleston) A History of Western Philosophy A las Barricadas A Legend of Old Egypt A Letter Concerning Toleration A maiore ad minus A Mathematician's Apology A Message from the Emperor A minore ad maius A New Era of Thought A New Model of the Universe A New Philosophy of Society: Assemblage Theory and Social Complexity A New Refutation of Time A Philosophical Enquiry into the Origin of Our Ideas of the Sublime and Beautiful A posteriori A priori (philosophy) A priori and a posteriori A Salty Piece of Land A Scanner Darkly A Secular Humanist Declaration A Short History of Chinese Philosophy A System of Logic A Thousand Plateaus A Thousand Years of Nonlinear History A Treatise Concerning the Principles of Human Knowledge A Treatise of Human Nature A Vindication of Natural Society A Vindication of the Rights of Men A Vindication of the Rights of Woman A Voyage to Arcturus A. A. Long A. A. Luce A. C. Ewing A. C. Grayling A. D. Gordon A. H. Almaas A. H. Armstrong A. J. Baker (philosopher) A. V. Dicey A. W. Benn A. P. Martinich A. R. Natarajan Ab ovo Abacus logic Abahlali baseMjondolo Abandonment (existentialism) Abas (sophist) Abbasgulu Bakikhanov Abd al-Karīm ibn Hawāzin al-Qushayri Abd al-Rahman al-Kawakibi Abd al-Rahman Ibn Khaldun Abdallah ibn Yasin Abdel-Halim Mahmoud Abdel Rahman Badawi Abdel Wahab Elmessiri Abderites Abdoldjavad Falaturi Abdolkarim Soroush Abductive logic programming Abductive reasoning Abductive validation Abdullah Yusuf Azzam Abdurrahman Ibn Khaldun Abdurrahmān Ibn Khaldūn Abel Paz Abhayakaragupta Abhidhamma Pitaka Abhidharma Abhinavagupta Abilene paradox Abimael Guzmán Abjection Abjunction Abner of Burgos Abner Shimony Abolishing the Borders from Below Abortion Abortion debate Aboutness Abraham Abigdor Abraham Abulafia Abraham bar Hiyya Abraham ben Moses Maimon Abraham ben Moses Maimonides Abraham Cohen de Herrera Abraham Edel Abraham ibn Daud Abraham Ibn Daud Abraham ibn Ezra Abraham Ibn Ezra Abraham Isaac Kook Abraham Joshua Heschel Abraham Kaplan Abraham Kovoor Abraham Leon Abraham Robinson Abraham Tucker Abraham Yagel Abraham Yehudah Khein Abram Deborin Absolute (philosophy) Absolute atheism Absolute idealism Absolute Infinite Absolute space Absolute theory Absolute threshold Absolute time Absolute truth Abstinence Abstract art Abstract entity Abstract expressionism Abstract Illusionism Abstract Imagists Abstract labour and concrete labour Abstract object Abstract objects Abstract particulars Abstract process Abstract semantic graph Abstraction Abstraction (philosophy) Abstractionism Absurdism Abu'l Hasan Muhammad Ibn Yusuf al-'Amiri Abu'l Walid Muhammad Ibn Rushd Abu 'Ali al-Husayn Ibn Sina Abu al-Hakam al-Kirmani Abu al-Hasan al-Ash'ari Abu Bakr Ibn Bajja Abu Bakr Ibn Bājja Abu Bakr Ibn Ţufayl Abu Bakr Muhammad Ibn Tufayl Abu Bakr Muhammad Ibn Yahya Ibn as-Say'igh Ibn Bajja Abu Bakr Muhammad Ibn Zakariyya' al-Razi Abu Hamid al-Ghazali Abu Hamid Muhammad al-Ghazali Abū Hayyān al-Tawhīdī Abu Mansur Maturidi Abu Muhammad 'Ali Ibn Hazm Abu Nasr al-Farabi Abū Nasr al-Fārābī Abu Rayhan Biruni Abu Sulayman al-Sijistani Abu Sulayman Muhammad al-Sijistani Abu Tahir Marwazi Abu Yaqub Sijistani Abu Yusuf Ya'qub ibn Ishaq al-Kindi Abul Ala Maududi Academic art Academic authorship Academic freedom Academic skepticism Academy Acatalepsy Accademia degli Infiammati Accent Acceptance Accessibility Accessibility relation Accident Accident (fallacy) Accident (philosophy) Accidental necessity Accidental properties Accidental property Accidentalism Accidie Accountability Accountant-client privilege Accounting ethics Accounting reform Accumulation by dispossession Acharya Hemachandra Achieving Our Country Achille Gagliardi Achille Varzi (philosopher) Achilles paradox Achintya Bheda Abheda Acosmism Acquaintance Acquiescence bias Acquired taste Acrasia Acratas Acrion Act utilitarianism Acting Out (book) Action (philosophy) Action at a distance Action Philosophers! Action theory (philosophy) Action verb Active citizenship Active intellect Actor–observer bias Acts of Literature Acts of the Apostles Actual idealism Actual Idealism Actual infinite Actual infinity Actualism Actualist Actuality Actuel Marx Actus et potentia Actus primus Actus purus Acumenus Acyutananda Ad captandum Ad feminam Ad hoc Ad hoc hypothesis Ad hominem Ad hominem argument Ad infinitum Ad nauseam Ada Albrecht Adalbertus Ranconis de Ericinio Adam Burski Adam de Buckfield Adam de Wodeham Adam Ferguson Adam Ignacy Zabellewicz Adam Karl August von Eschenmayer Adam Mahrburg Adam Morton Adam Müller Adam of Łowicz Adam Parvipontanus Adam Pulchrae Mulieris Adam Schaff Adam Smith Adam Steuart Adam Tanner (mathematician) Adam Weishaupt Adam Wodeham Adam Zachary Newton Adamantios Korais Adamites Adaptation Adaptive bias Adaptive grammar Adaptive representation Adaptive system Addiction Addison Webster Moore Addition (logic) Adela Cortina Adelard of Bath Adevism Adi (metaphysical plane) Adi Ophir Adi Sanakara Philosophy Adi Shankara Adiaphora Adicity Admissible rule Adolf Grunbaum Adolf Grünbaum Adolf Lasson Adolf Lindenbaum Adolf Reinach Adolf von Harnack Adolfo Sánchez Vázquez Adolfo Veber Tkalčević Adolph Stöhr Adrastus of Aphrodisias Adriaan Koerbagh Adrian Piper Adriana Cavarero Adriano Tilgher (philosopher) Adrianus Adrsta Adultery Advaita Advaita Vedanta Advance health care directive Adventures of Wim Adverbs Adverse effect Advertising Advice (opinion) Aedesia Aedesius Aeneas of Gaza Aenesidemus Aenesidemus (book) Aequiprobabilism Aesara Aeschines of Neapolis Aeschines of Sphettus Aesthetic distance Aesthetic emotions Aesthetic of Ugliness Aesthetic Realism Aesthetic relativism Aestheticism Aestheticization of politics Aestheticization of violence Aesthetics Aesthetics of music Aeterni Patris Aether Aether (classical element) Aetius (philosopher) Affect (philosophy) Affect heuristic Affection Affectionism Affective Affective forecasting Affine logic Affirmative action Affirmative conclusion from a negative premise Affirming a disjunct Affirming the antecedent Affirming the consequent African philosophy African Spir African Uplands Africana philosophy Africana womanism Afrikan Spir Afshin Ellian After Many a Summer After Virtue Afterlife Against Civilization: Readings and Reflections Against His-Story, Against Leviathan Against the Day Āgama (Buddhism) Āgama (Hinduism) Āgama (Jainism) Agama Hindu Dharma Agapē Agapē Agape Agapius of Athens Agathism Agathobulus Agathon Agathosthenes Agathusia and aschimothusia Age of Enlightenment Age of reason Age of reason (canon law) Agency (philosophy) Agent (law) Agent Communications Language Aggadah Aggression Aggressionism Ágnes Heller Agnostic Agnostic atheism Agnostic existentialism Agnostic theism Agnosticism Agonism Agonistic liberalism Agonistic pluralism Agorism Agostinho da Silva Agostino Nifo Agrarianism Agricultural philosophy Agrippa the Skeptic Ahad Ha'am Ahamkāra Ahankara Ahimsa Ahimsa in Jainism Ahistoricism Ahl ar-ra'y Ahmad Ahmadi (philosopher) Ahmad Fardid Ahmad Ibn Muhammad Ibn Miskawayh Ahmad Nadeem Qasimi Ahmad Sirhindi Ahmed Hulusi Ahura Mazda AI effect Ai Siqi Aijaz Ahmad Aizawa Seishisai Ajahn Amaro Ajahn Chah Ajahn Sumedho Ajahn Sundara Ajita Kesakambali Ajivika AK Press Ākāśa Akeel Bilgrami Akira Asada Akira Yamada Akka Mahadevi Akrasia Al-Farabi Al-Fārābī Al-Ghazali Al-Ghazālī Al-Hajj Salim Suwari Al-Hilli Al-Jahiz Al-Jubba'i Al-Juwayni Al-Khazini Al-Khidr Al-Kindi Al-Kindī Al-Ma`arri Al-Mawardi Al-Nahda Al-Rāzī Al-Shahrastani Al-Shahrazuri Al-Shirazi Al-Sijistani Al-Tabarani Al-Tawhidi Al-Zamakhshari Al Amiri Alain Badiou Alain de Benoist Alain de Botton Alain de Lille Alain Etchegoyen Alain Finkielkraut Alain LeRoy Locke Alan Carter (philosopher) Alan Donagan Alan Gewirth Alan Grant (writer) Alan Mathison Turing Alan Millar Alan Moore Alan Musgrave Alan of Lynn Alan Ross Anderson Alan Ryan Alan Soble Alan Stout (philosopher) Alan Turing Alan Watts Alan Woods (politician) Alasdair C. MacIntyre Alasdair MacIntyre Alasdair Urquhart Alastair Hannay Alastair Norcross Ālaya-vijñāna Albert (short story) Albert Blumberg Albert Borgmann Albert Camus Albert Chernenko Albert Einstein Albert Lautman Albert Meltzer Albert of Saxony (philosopher) Albert Outler Albert Parsons Albert Rivaud Albert Schwegler Albert Schweitzer Albert Venn Dicey Alberto Jori Alberto Moreiras Alberto Toscano Albertus Magnus Albinus (philosopher) Albrecht Ritschl Albrecht von Müller Albrecht Wellmer Alchemy Alcinous (philosopher) Alciphron (book) Alcmaeon of Croton Alcuin Aldo Gargani Alejandro Deustua Alejandro Korn Alejandro Rossi Alejandro Rozitchner Aleksander Świętochowski Aleksandr Danilovich Aleksandrov Aleksandr Ivanovich Herzen Aleksandr Zinovyev Aleksei Losev Aleksey Khomyakov Alenka Zupančič Aleš Ušeničnik Alessandro Achillini Alessandro Piccolomini Aletheia Alethiology Alex Callinicos Alex Comfort Alex Grey Alexamenus of Teos Alexander Atabekian Alexander Bain Alexander Berkman Alexander Bogdanov Alexander Bonini Alexander Bryan Johnson Alexander Campbell Fraser Alexander Crombie Alexander Esenin-Volpin Alexander George (philosopher) Alexander Gerard Alexander Gottlieb Baumgarten Alexander Herzen Alexander Meiklejohn Alexander Neckam Alexander Neckham Alexander Nehamas Alexander of Aegae Alexander of Aphrodisias Alexander of Hales Alexander Pfänder Alexander Piatigorsky Alexander Rosenberg Alexander S. Kechris Alexander Schapiro Alexander Sutherland (educator) Alexander Tille Alexandr Ivanovich Herzen Alexandre Kojeve Alexandre Kojève Alexandre Koyré Alexandrian school Alexandros Schinas Alexandru Bogdan-Piteşti Alexandru Dragomir Alexicrates Alexinus Alexis de Tocqueville Alexis Kagame Alexis Rosenbaum Alexius Meinong Alf Ahlberg Alf Ross Alfonso Falero Alfred Adler Alfred Baeumler Alfred Binet Alfred Brunswig Alfred Edward Taylor Alfred Espinas Alfred Henry Lloyd Alfred Horn Alfred I. Tauber Alfred Jules Ayer Alfred Jules Émile Fouillée Alfred Kastil Alfred Loisy Alfred Mele Alfred North Whitehead Alfred of Sareshel Alfred Rosenberg Alfred Russel Wallace Alfred Schmidt (philosopher) Alfred Schutz Alfred Schütz Alfred Sohn-Rethel Alfred Tarski Alfred Wilm Alfredo M. Bonanno Algazel Algebra Algebraic normal form Algernon Charles Swinburne Algorithm Alhazen Alic Halford Smith Alice Ambrose Alice Bailey Alice von Hildebrand Alienation Alison Wylie All All About Love: New Visions All and Everything All horses are the same color All men are created equal All That Is Solid Melts into Air All Truth Is God's Truth Allan Antliff Allan Bloom Allan Gibbard Allan Gotthelf Allan Ramsay (1713-1784) Allegory of the cave Allegory of the Cave Allen Buchanan Alois Riehl Alon Ben-Meir Alonso Gutiérrez Alonzo Church Aloys Hirt Alpha et Omega Alphabet of human thought Alphonso Lingis Altered state of consciousness Alterity Alternative denial Alternative dispute resolution Alternative Media Project Alternative Press Review Altheides Altruism Alvin Goldman Alvin Plantinga Always already Ama-gi Amadeo Bordiga Amafinius Amakasu Incident Amalric of Bena Amartya K. Sen Amartya Sen Ambiguity Ambiguity effect Ambrose Ambrosius Theodosius Macrobius Amelius America at the Crossroads American Bar Association Model Code of Professional Responsibility American Bar Association Model Rules of Professional Conduct American Catholic Philosophical Association American Catholic Philosophical Quarterly American Craftsman American Empire (style) American Enlightenment American Indian Movement American Journal of Bioethics American Philosophical Association American Philosophical Quarterly American Philosophical Society American philosophy American realism American Society for Political and Legal Philosophy Amerika (novel) Amicus Plato, sed magis amica veritas Amilcar Cabral Amílcar Cabral Amilcare Cipriani Ammon Hennacy Ammonius Hermiae Ammonius of Alexandria (Christian philosopher) Ammonius of Athens Ammonius Saccas Amoralism Amorality Amos Bronson Alcott Amour-propre Amour de soi Amphibology Amphiboly Amsterdam Declaration Amy Gutmann Amynomachus An Enquiry concerning Human Understanding An Enquiry Concerning Human Understanding An Enquiry Concerning the Principles of Morals An Essay Concerning Human Understanding An Essay on the History of Civil Society An Essay on the Principle of Population An Honest Thief An Hyang An Intelligent Person's Guide to Atheism An Occurrence at Owl Creek Bridge An Sich Anacharsis Anāgāmi Analects Analects of Confucius Analogy Analogy of the divided line Analysis Analysis (journal) Analysis (philosophy) Analysis paralysis Analytic philosophy Analytic-synthetic distinction Analytic and synthetic knowledge Analytic and synthetic statements Analytic ethics Analytic hierarchy Analytic jurisprudence Analytic knowledge Analytic Marxism Analytic philosophy Analytic proof Analytic proposition Analytic reasoning Analytical hierarchy Analytical jurisprudence Analytical philosophy Analytical psychology Analytical Thomism Anamnesis (philosophy) Anamorphosis Anan ben David Ānanda Ananda Coomaraswamy Anandamaya kosha Anandavardhana Anangeon Ananke Anantarika-karma Anaphor Anaphora Anarch (sovereign individual) Anarcha-feminism Anarchism Anarchism and anarcho-capitalism Anarchism and animal rights Anarchism and capitalism Anarchism and Friedrich Nietzsche Anarchism and Islam Anarchism and Marxism Anarchism and nationalism Anarchism and the arts Anarchism and violence Anarchism in Africa Anarchism in America (film) Anarchism in Asia Anarchism in Australia Anarchism in Brazil Anarchism in Canada Anarchism in China Anarchism in Cuba Anarchism in England Anarchism in France Anarchism in Greece Anarchism in Iceland Anarchism in India Anarchism in Ireland Anarchism in Israel Anarchism in Italy Anarchism in Japan Anarchism in Korea Anarchism in Mexico Anarchism in Poland Anarchism in Russia Anarchism in Spain Anarchism in Sweden Anarchism in the United States Anarchism in Turkey Anarchism in Ukraine Anarchism in Vietnam Anarchism without adjectives Anarchism: A Documentary History of Libertarian Ideas Anarchist Black Cross Anarchist Black Cross Federation Anarchist Black Cross Network Anarchist Bookfair Anarchist Catalonia Anarchist communism Anarchist Exclusion Act Anarchist Federation (Britain and Ireland) Anarchist law Anarchist Manifesto Anarchist People of Color Anarchist schools of thought Anarchist St. Imier International Anarchist Studies Anarchist symbolism Anarchist terminology Anarchistic free school Anarchists (film) Anarchists Against the Wall Anarcho-capitalism Anarcho-capitalism and minarchism Anarcho-capitalist literature Anarcho-capitalist symbolism Anarcho-pacifism Anarcho-primitivism Anarcho-punk Anarcho-syndicalism Anarcho-Syndicalism (book) Anarcho-Syndicalist Review Anarcho-syndicalist symbolism Anarchy Anarchy (book) Anarchy Alive! Anarchy Archives Anarchy Comics Anarchy in the Age of Dinosaurs Anarchy Magazine Anarchy, State, and Utopia Anarchy: A Journal of Desire Armed Anarky Anarky (comic book) Anat Biletzki Anathon Aall Anatoly Lunacharsky Anatta Anava Anaxagoras Anaxarchus Anaxilaus Anaximander Anaximenes of Miletus Ancestral Ancestral relation Anchoring Ancient commentators project Ancient Greek philosophy Ancient philosophy Ancient skepticism Ancient Wisdom, Modern World And you are lynching Negroes Anders Chydenius Anders Nygren Anders Vilhelm Lundstedt Ando Shoeki André-François Deslandes André-Marie Ampère André Comte-Sponville André Glucksmann André Gorz André Malet (philosopher) André Malraux André of Neufchâteau Andrea Bonomi Andrea Cesalpino Andreas Kinneging Andreas Speiser Andrei Andreevich Markov Andrei Marga Andrej Grubacic Andres Luure Andrés Ortiz-Osés Andrew Baxter Andrew Bernstein Andrew Feenberg Andrew Janiak Andrew of Cornwall Andrew Pyle (philosopher) Andrew Seth Pringle-Pattison Andries Mac Leod Androcentrism Androcydes (Pythagorean) Android epistemology Andronicus of Rhodes Andrzej Mostowski Andrzej Towiański Andy Blunden Andy Clark Andy Warhol Anekantavada Ángel Rama Angelaki Angeli (novel) Angelo Galli Anger Angie Hobbs Anglo-Japanese style Angst Anguish Angus Taylor (philosopher) Anima mundi Anima mundi (spirit) Animal consciousness Animal Experimentation: Opposing Viewpoints Animal language Animal Liberation (book) Animal rights Animal spirits Animals in Buddhism Animistic fallacy Anioł Dowgird Anja Steinbauer Anna-Teresa Tymieniecka Anna Maria van Schurman Anne Conway, Viscountess Conway Anne Finch Anne Louise Germaine de Staël Annemarie Gethmann-Siefert Annemarie Mol Annette Baier Anniceris Anomalous monism Anomie Ansatz Anselm Jappe Anselm of Canterbury Anselm of Laon Anselme Bellegarrigue Ansgar Beckermann Answer to Job Answering the Question: What Is Enlightenment? 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Young Arthur Moeller van den Bruck Arthur Norman Prior Arthur Oncken Lovejoy Arthur Pap Arthur Prior Arthur Schafer Arthur Schopenhauer Arthur Schopenhauer's aesthetics Arthur Stanley Eddington Arthur Willink Artificial brain Artificial consciousness Artificial intelligence Artificial language Artificial life Artist Artistic expression Artistic freedom Artistic inspiration Artistic interpretation Artistic merit Artistic revolution Artistic style Arto Haapala Arts and Crafts Movement Arts criticism Arturo Andrés Roig Artworld Arvi Grotenfelt Arya Arya Samaj Aryadeva As a Man Thinketh As I Lay Dying (novel) As I was going to St Ives As if As She Climbed Across the Table Asa Gray Asa Kasher Asanga Asceticism Asclepiades of Phlius Asclepiades the Cynic Asclepigenia Asclepiodotus (philosopher) Asclepiodotus of Alexandria Asclepius of Tralles Ascribed status Ascriptivism Aseity Ashanti Alston Ashcan School Asher Ginzberg Ashley Treatment Ashtamangala Asian values Asiatic mode of production Askapāda Gotama Asociación Continental Americana de Trabajadores Aspasius Assertion Assertoric Assi Rahbani Assisted suicide Association fallacy Association for Logic, Language and Information Association for Symbolic Logic Association for the Scientific Study of Consciousness Association of Autonomous Astronauts Association of ideas Associationism Associative law Āstika and nāstika Astrology Aśvaghoṣa Asymmetrical Ataraxia Ateneo de la Juventud Athanasius of Alexandria Atheism Atheist's Wager Atheist existentialism Athenaeus of Seleucia Athenian democracy Athenodoros Cananites Athenodoros Cordylion Athenodorus of Soli Athens Athīr al-Dīn al-Abharī Atisha Atlantis Atlas Shrugged Atman (Buddhism) Ātman (Buddhism) Atman (Hinduism) Atomic fact Atomic sentence Atomism Atonement in Christianity Atonement in Judaism Atopy (philosophy) Atrocity story Attacking Faulty Reasoning Attalus (Stoic) Attempt at a Critique of All Revelation Attentional bias Atticus (philosopher) Attitude (psychology) Attitude polarization Attorney–client privilege Attorney misconduct Attorney/client privilege Attribute grammar Attribution theory Attributional bias Auberon Herbert Auctoritas Auctoritates Aristotelis Aufheben Augmented Backus–Naur form Augoeides August Cieszkowski August Wilhelm Schlegel Auguste Comte Auguste Vaillant Augustin Bonnetty Augustin Souchy Augustine Eriugena Augustine of Hippo Augustinian Studies Augustinian values Augusto César Sandino Augusto Vera Augustus De Morgan Aulus Egnatius Priscillianus Aulus Gellius Aurel Kolnai Austin Farrer Austin Marsden Farrer Austin Woodbury Australasian Association of Philosophy Australasian Journal of Philosophy Australian materialism Australian realism Austrofascism Autarchism Authenticity (philosophy) Authoritarianism Authority Auto-destructive art Autocracy Autoepistemic logic Autological Automata theory Automated reasoning Automatic sequence Automaton Autonomedia Autonomism Autonomous Action Autonomy Autopoiesis Avadhuta Gita Availability heuristic Avant-garde Avant-Garde and Kitsch Avatar Avecebrol Avempace Average and total utilitarianism Averaging argument Averroes Averroës Averroism Aversion therapy Avicebrol Avicebron Avicenna Avicenna Prize Avicennism Avidya (Hinduism) Avidyā (Buddhism) Avishai Margalit Avital Ronell Avodah Avraham son of Rambam Avrum Stroll Awareness Awareness League Axel Hägerström Axel Honneth Axial Age Axiochus (dialogue) Axiology Axiom Axiom of abstraction Axiom of choice Axiom of comprehension Axiom of Equity Axiom of extensionality Axiom of infinity Axiom of projective determinacy Axiom of reducibility Axiom of replacement Axiom of separation Axiom S5 Axiom schema Axiomatic method Axiomatic set theory Axiomatic system Axiomatization Axiothea of Phlius Ayatana Ayn al-Quzat Hamadani Ayn Rand Ayn Rand: A Sense of Life Ayn Rand: The Russian Radical Ayurveda Ayyavazhi Ayyavazhi phenomenology Azizah Y. al-Hibri Aztec philosophy B B-series B-Theory of time B. 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Traven Babette Babich Baby K Backgammon Backus–Naur form Backward causation Backward chaining Bad faith Bad faith (existentialism) Baden School Bahmanyār Bahshamiyya Bahya ibn Paquda Baker Brownell Balance (metaphysics) Balance of nature Balangoda Ananda Maitreya Baltasar Gracián Balthasar Bekker Banality of evil Banausos Bandwagon effect Bantu Philosophy Baptista Mantuanus Baptists in the history of separation of church and state Barba non facit philosophum Barbara Barbara Forrest Barbara Herrnstein Smith Barber paradox Barbershop paradox Barbizon school Barcan formula Barcelona May Days Bardo Bare particular Bargaining theory Barhaspatya sutras Barlaam of Seminara Baron d'Holbach Baron de Montesquieu Baron Herbert of Cherbury Baroque Baroque Revival architecture Barracks communism Barrie Karp Barrows Dunham Barry Loewer Barry Smith (ontologist) Barry Stroud Bartholomäus Keckermann Bartholomew Des Bosses Bartholomew Keckermann Bartholomew of Bologna (philosopher) Bartolomé de Medina Bartolommeo Spina Bartolus de Saxoferrato Baruch Spinoza Barwise prize Barzillai Quaife Bas C. van Fraassen Bas Haring Bas van Fraassen Base and superstructure Base and superstructure (Marxism) Base rate fallacy Basic belief Basic Limiting Principle Basic norm Basic Points Unifying the Theravāda and the Mahāyāna Basil Mitchell (academic) Basilides Basilides (Stoic) Basilides the Epicurean Basilios Bessarion Batis of Lampsacus Batman: Anarky Battle of Peregonovka (1919) Bauhaus Bay Area Figurative Movement Bayes' theorem Bayes's rule Bayes's theorem Bayesian probability Bayesianism Beatific vision Béatrice Longuenesse Beatriz Sarlo Beauty Becoming Becoming (philosophy) Bedeutung Beelzebub's Tales to His Grandson Beerwolf Begging the question Begriffsschrift Behavior therapy Behavioral script Behavioralism Behaviorism Behaviourism Behind the Mirror: A Search for a Natural History of Human Knowledge Behold a Pale Horse (film) Being Being and becoming Being and Nothingness Being and Time Being beautiful in spirit Being for itself Being in itself Béla Balázs Béla Hamvas Belief Belief-Desire-Intention model Belief-in Belief bias Belief in Belief revision Bell's inequality Bell's theorem Bellum omnium contra omnes Belmont Report Ben Salem Himmich Benedetto Croce Benedict de Spinoza Benedict Pereira Benedictus Spinoza Benedito Nunes Beneficence Benjamin Apthorp Gould Fuller Benjamin Constant Benjamin Franklin Benjamin Lee (academic) Benjamin Paul Blood Benjamin Peirce Benjamin Tucker Benjamin Whichcote Benny Lévy Benoît Broutchoux Benoît de Maillet Benson Mates Berlin Circle Bernard-Henri Lévy Bernard A. 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Anthony Anderson C. D. Broad C. E. M. Joad C. I. Lewis C. Lloyd Morgan C. S. Lewis C. S. Lewis bibliography C. Stephen Evans C. T. K. Chari C. A. J. 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18271	https://en.wikipedia.org/wiki/Lamborghini	Lamborghini	Automobili Lamborghini S.p.A. () is an Italian brand and manufacturer of luxury sports cars and SUVs based in Sant'Agata Bolognese. The company is owned by the Volkswagen Group through its subsidiary Audi. Ferruccio Lamborghini, an Italian manufacturing magnate, founded Automobili Ferruccio Lamborghini S.p.A. in 1963 to compete with Ferrari. The company was noted for using a rear mid-engine, rear-wheel drive layout. Lamborghini grew rapidly during its first decade, but sales plunged in the wake of the 1973 worldwide financial downturn and the oil crisis. The firm's ownership changed three times after 1973, including a bankruptcy in 1978. American Chrysler Corporation took control of Lamborghini in 1987 and sold it to Malaysian investment group Mycom Setdco and Indonesian group V'Power Corporation in 1994. In 1998, Mycom Setdco and V'Power sold Lamborghini to the Volkswagen Group where it was placed under the control of the group's Audi division. New products and model lines were introduced to the brand's portfolio and brought to the market and saw an increased productivity for the brand. In the late 2000s, during the worldwide financial crisis and the subsequent economic crisis, Lamborghini's sales saw a drop of nearly 50 per cent. Lamborghini currently produces the V12-powered Aventador and the V10-powered Huracán, along with the Urus SUV powered by a twin-turbo V8 engine. In addition, the company produces V12 engines for offshore powerboat racing. Lamborghini Trattori, founded in 1948 by Ferruccio Lamborghini, is headquartered in Pieve di Cento, Italy and continues to produce tractors. History Manufacturing magnate Italian Ferruccio Lamborghini founded the company in 1963 with the objective of producing a refined grand touring car to compete with offerings from established marques such as Ferrari. The company's first models, such as the 350 GT, were released in the mid-1960s. Lamborghini was noted for the 1966 Miura sports coupé, which used a rear mid-engine, rear-wheel drive layout. Lamborghini grew rapidly during its first ten years, but sales fell in the wake of the 1973 worldwide financial downturn and the oil crisis. Ferruccio Lamborghini sold the company to Georges-Henri Rossetti and René Leimer and retired in 1974. The company went bankrupt in 1978, and was placed in the receivership of brothers Jean-Claude and Patrick Mimran in 1980. The Mimrans purchased the company out of receivership by 1984 and invested heavily in its expansion. Under the Mimrans' management, Lamborghini's model line was expanded from the Countach to include the Jalpa sports car and the LM002 high-performance off-road vehicle. The Mimrans sold Lamborghini to the Chrysler Corporation in 1987. After replacing the Countach with the Diablo and discontinuing the Jalpa and the LM002, Chrysler sold Lamborghini to Malaysian investment group Mycom Setdco and Indonesian group V'Power Corporation in 1994. In 1998, Mycom Setdco and V'Power sold Lamborghini to the Volkswagen Group where it was placed under the control of the group's Audi division. New products and model lines were introduced to the brand's portfolio and brought to the market and saw an increased productivity for the brand Lamborghini. In the late 2000s, during the worldwide financial crisis and the subsequent economic crisis, Lamborghini's sales saw a drop of nearly 50 per cent. In 2021, the CEO of Lamborghini said that by 2024 all its models will be hybrid. Products Automobiles As of the 2018 model year, Lamborghini's automobile product range consists of three model lines, two of which are mid-engine two-seat sports cars while the third one is a front engined, all-wheel drive SUV. Models in production Aventador The current V12-powered Aventador production line consists of the LP 740–4 Aventador Ultimate and SVJ coupés and roadsters and it is said that the production of all Aventador models will end in 2022. Huracán The V10-powered Huracán line currently includes the all-wheel-drive LP 610-4 coupé and Spyder, the low cost rear-wheel-drive LP 580-2 coupé and spyder and the most powerful, track oriented LP 640-4 Performanté coupé and spyder. Urus With the intention of doubling its sales volume by 2019, Lamborghini also added an SUV named Urus in its line-up which is powered by a twin-turbo V8 engine and utilises a front engine, all-wheel drive layout. Marine engines Motori Marini Lamborghini produces a large V12 marine engine block for use in World Offshore Series Class 1 powerboats. A Lamborghini branded marine engine displaces approximately and outputs approximately . Lamborghini motorcycle In the mid-1980s, Lamborghini produced a limited-production run of a sports motorcycle. UK weekly newspaper Motor Cycle News reported in 1994 – when featuring an example available through an Essex motorcycle retailer – that 24 examples were produced with a Lamborghini alloy frame having adjustable steering head angle, Kawasaki GPz1000RX engine/transmission unit, Ceriani front forks and Marvic wheels. The bodywork was plastic and fully integrated with front fairing merged into fuel tank and seat cover ending in a rear tail-fairing. The motorcycles were designed by Lamborghini stylists and produced by French business Boxer Bikes. Branded merchandise Lamborghini licenses its brand to manufacturers that produce a variety of Lamborghini-branded consumer goods including scale models, clothing, accessories, bags, electronics and laptop computers. Motorsport Automobiles produced Lamborghini Motorsport Division Squadra Corse produces GT3 cars and cars for their Super Trofeo events based on the Gallardo and Huracán. Apart from them, the Squadra Corse builds cars upon customer request. GT3 and Super Trofeo Cars Gallardo LP 570-4 Super Trofeo Gallardo LP560-4 Super Trofeo Huracán LP 620-2 Super Trofeo EVO Huracán LP 620-2 Super Trofeo EVO2 Huracán Super Trofeo GT2 Huracán GT3 Huracán GT3 Evo Special cars These cars were built by Squadra Corse upon customer request. Essenza SCV12 SC18 Alston SC20 Events held Lamborghini Super Trofeo The Super Trofeo is a series of Motorsport events held by Squadra corse using their Super Trofeo model vehicles (currently the Huracán Super Trofeo EVO) which are racing versions of the road-approved models (Huracán and Gallardo models). The Super Trofeo events are held in three different series, in three continents: America, Asia and Europe. Many private race team participate each of these events. Every series consists of six rounds, each of which feature free practice sessions, qualifying and two races lasting 50 minutes each. There are four categories of drivers: Pro, Pro-Am, Am and Lamborghini Cup. The season ends in the Lamborghini Super Trofeo World Final. Lamborghini GT3 The Lamborghini GT3 is a series of Motorsport events held by The Squadra Corse using Huracán GT3 cars that comply with the FIA GT3 regulations. The racing event is open to any Huracán GT3 customer. Lamborghini currently uses Huracán GT3 Evo cars for these events and more than 60 private race teams participate these events. Lamborghini F1 career In contrast to his rival Enzo Ferrari, Ferruccio Lamborghini had decided early on that there would be no factory-supported racing of Lamborghinis, viewing motorsport as too expensive and too draining on company resources. This was unusual for the time, as many sports car manufacturers sought to demonstrate speed, reliability, and technical superiority through motorsport participation. Enzo Ferrari in particular was known for considering his road car business mostly a source of funding for his participation in motor racing. Ferruccio's policy led to tensions between him and his engineers, many of whom were racing enthusiasts; some had previously worked at Ferrari. When Dallara, Stanzani, and Wallace began dedicating their spare time to the development of the P400 prototype, they designed it to be a road car with racing potential, one that could win on the track and also be driven on the road by enthusiasts. When Ferruccio discovered the project, he allowed them to go ahead, seeing it as a potential marketing device for the company, while insisting that it would not be raced. The P400 went on to become the Miura. The closest the company came to building a true race car under Lamborghini's supervision were a few highly modified prototypes, including those built by factory test driver Bob Wallace, such as the Miura SV-based "Jota" and the Jarama S-based "Bob Wallace Special". In the mid-1970s, while Lamborghini was under the management of Georges-Henri Rossetti, Lamborghini entered into an agreement with BMW to develop, then manufacture 400 cars for BMW in order to meet Group 4 homologation requirements. BMW lacked experience developing a mid-engined vehicle and believed that Lamborghini's experience in that area would make Lamborghini an ideal choice of partner. Due to Lamborghini's shaky finances, Lamborghini fell behind schedule developing the car's structure and running gear. When Lamborghini failed to deliver working prototypes on time, BMW took the program in house, finishing development without Lamborghini. BMW contracted with Baur to produce the car, which BMW named the M1, delivering the first vehicle in October 1978. In 1985, Lamborghini's British importer developed the Countach QVX, in conjunction with Spice Engineering, for the 1986 Group C championship season. One car was built, but lack of sponsorship caused it to miss the season. The QVX competed in only one race, the non-championship 1986 Southern Suns 500 km race at Kyalami in South Africa, driven by Tiff Needell. Despite the car finishing better than it started, sponsorship could once again not be found and the programme was cancelled. Lamborghini was an engine supplier in Formula One for the 1989 through 1993 Formula One seasons. It supplied engines to Larrousse (1989–1990, 1992–1993), Lotus (1990), Ligier (1991), Minardi (1992), and to the Modena team in 1991. While the latter is commonly referred to as a factory team, the company saw itself as a supplier, not a backer. The 1992 Larrousse–Lamborghini was largely uncompetitive but noteworthy in its tendency to spew oil from its exhaust system. Cars following closely behind the Larrousse were commonly coloured yellowish-brown by the end of the race. Lamborghini's best result was achieved with Larrousse at the 1990 Japanese Grand Prix, when Aguri Suzuki finished third on home soil. In late 1991, a Lamborghini Formula One motor was used in the Konrad KM-011 Group C sports car, but the car only lasted a few races before the project was cancelled. The same engine, re-badged a Chrysler, Lamborghini's then-parent company, was tested by McLaren towards the end of the 1993 season, with the intent of using it during the 1994 season. Although driver Ayrton Senna was reportedly impressed with the engine's performance, McLaren pulled out of negotiations, choosing a Peugeot engine instead, and Chrysler ended the project. Two racing versions of the Diablo were built for the Diablo Supertrophy, a single-model racing series held annually from 1996 to 1999. In the first year, the model used in the series was the Diablo SVR, while the Diablo 6.0 GTR was used for the remaining three years. Lamborghini developed the Murciélago R-GT as a production racing car to compete in the FIA GT Championship, the Super GT Championship and the American Le Mans Series in 2004. The car's highest placing in any race that year was the opening round of the FIA GT Championship at Valencia, where the car entered by Reiter Engineering finished third from a fifth-place start. In 2006, during the opening round of the Super GT championship at Suzuka, a car run by the Japan Lamborghini Owners Club garnered the first victory (in class) by an R-GT. A GT3 version of the Gallardo has been developed by Reiter Engineering. A Murciélago R-GT entered by All-Inkl.com racing, driven by Christophe Bouchut and Stefan Mücke, won the opening round of the FIA GT Championship held at Zhuhai International Circuit, achieving the first major international race victory for Lamborghini. Complete Formula One results (key) (results in bold indicate pole position) Marketing Brand identity The world of bullfighting is a key part of Lamborghini's identity. In 1962, Ferruccio Lamborghini visited the Seville ranch of Don Eduardo Miura, a renowned breeder of Spanish fighting bulls. Lamborghini, a Taurus himself, was so impressed by the majestic Miura animals that he decided to adopt a raging bull as the emblem for the automaker he would open shortly. Vehicle nomenclature After producing two cars with alphanumeric designations, Lamborghini once again turned to the bull breeder for inspiration. Don Eduardo was filled with pride when he learned that Ferruccio had named a car for his family and their line of bulls; the fourth Miura to be produced was unveiled to him at his ranch in Seville. The automaker would continue to draw upon the bullfighting connection in future years. The Islero was named for the Miura bull that killed the famed bullfighter Manolete in 1947. Espada is the Spanish word for sword, sometimes used to refer to the bullfighter himself. The Jarama's name carried a special double meaning; though it was intended to refer only to the historic bullfighting region in Spain, Ferruccio was concerned about confusion with the also historic Jarama motor racing track. After christening the Urraco after a bull breed, in 1974, Lamborghini broke from tradition, naming the Countach () not for a bull, but for (), a Piedmontese expletive. Legend has it that stylist Nuccio Bertone uttered the word in surprise when he first saw the Countach prototype, "Project 112". The LM002 (LM for Lamborghini Militaire) sport utility vehicle and the Silhouette (named after the popular racing category of the time) were other exceptions to the tradition. The Jalpa of 1982 was named for a bull breed; Diablo, for the Duke of Veragua's ferocious bull famous for fighting an epic battle against El Chicorro in Madrid in 1869; Murciélago, the legendary bull whose life was spared by El Lagartijo for his performance in 1879; Gallardo, named for one of the five ancestral castes of the Spanish fighting bull breed; and Reventón, the bull that defeated young Mexican torero Félix Guzmán in 1943. The Estoque concept of 2008 was named for the estoc, the sword traditionally used by matadors during bullfights. Concept vehicles Throughout its history, Lamborghini has envisioned and presented a variety of concept cars, beginning in 1963 with the very first Lamborghini prototype, the 350GTV. Other famous models include Bertone's 1967 Marzal, 1974 Bravo, and 1980 Athon, Chrysler's 1987 Portofino, the Italdesign-styled Cala from 1995, the Zagato-built Raptor from 1996. A retro-styled Lamborghini Miura concept car, the first creation of chief designer Walter de'Silva, was presented in 2006. President and CEO Stephan Winkelmann denied that the concept would be put into production, saying that the Miura concept was "a celebration of our history, but Lamborghini is about the future. Retro design is not what we are here for. So we won’t do the [new] Miura.” At the 2008 Paris Motor Show, Lamborghini revealed the Estoque, a four-door sedan concept. Although there had been much speculation regarding the Estoque's eventual production, Lamborghini management has not made a decision regarding production of what might be the first four-door car to roll out of the Sant'Agata factory. At the 2010 Paris Motor Show, Lamborghini unveiled the Sesto Elemento. The concept car is made almost entirely of carbon fibre making it extremely light, with a weight of . The Sesto Elemento shares the same V10 engine found in the Lamborghini Gallardo. Lamborghini hopes to signal a shift in the company's direction from making super cars focused on top speed to producing more agile, track focused cars with the Sesto Elemento. The concept car can reach in 2.5 seconds and can reach a top speed of over 180 mph. At the 2012 Geneva Motor Show, Lamborghini unveiled the Aventador J – a roofless, windowless version of the Lamborghini Aventador. The Aventador J uses the same 700 hp engine and seven-speed transmission as the standard Aventador. At the 2012 Beijing Motor Show, Lamborghini unveiled the Urus SUV. This is the first SUV built by Lamborghini since the LM002. As part of the celebration of 50 years of Lamborghini, the company created the Egoista. Egoista is for one person's driving and only one Egoista is to be made. At the 2014 Paris Motor Show, Lamborghini unveiled the Asterion LPI910-4 hybrid concept car. Named after the half-man, half-bull hybrid (Minotaur) of Greek legend, it is the first hybrid Lamborghini in the history of the company. Utilizing the Huracán's 5.2 litre V10 producing , along with one electric motor mounted on the transaxle and an additional two on the front axle, developing an additional . This puts the power at a combined figure of . The time is claimed to be just above 3 seconds, with a claimed top speed of . Corporate affairs Structure As of 2011, Lamborghini is structured as a wholly-owned subsidiary of Audi AG named Automobili Lamborghini S.p.A. Automobili Lamborghini S.p.A. controls five principal subsidiaries: Ducati Motor Holding S.p.A., a manufacturer of motorcycles; Italdesign Giugiaro S.p.A., a 90.1%-owned design and prototyping firm that provides services to the entire Volkswagen Group; MML S.p.A. (Motori Marini Lamborghini), a manufacturer of marine engine blocks; and Volkswagen Group Italia S.p.A. (formerly Autogerma S.p.A.), which sells Audi and other Volkswagen Group vehicles in Italy. The Lamborghini headquarters and main production site is located in Sant'Agata Bolognese, Italy. With the launch of its Urus SUV, the production site expanded from 80,000 to 160,000 square meters. On 13 November 2020, Stephan Winkelmann, current President of Bugatti, was appointed to be the new CEO of Lamborghini. He takes up his new position as of December 1, 2020. Sales results By sales, the most important markets in 2004 for Lamborghini's sports cars were the U.S. (41%), Germany (13%), Great Britain (9%) and Japan (8%). Prior to the launch of the Gallardo in 2003, Lamborghini produced approximately 400 vehicles per year; in 2011 Lamborghini produced 1,711 vehicles. Annual Lamborghini new car sales Licensing Automóviles Lamborghini Latinoamérica Automóviles Lamborghini Latinoamérica S.A. de C.V. (Lamborghini Automobiles of Latin America Public Limited Company) is an authorized distributor and manufacturer of Lamborghini-branded vehicles and merchandise in Latin America and South America. In 1995, Indonesian corporation MegaTech, Lamborghini's owner at the time, entered into distribution and license agreements with Mexican businessman Jorge Antonio Fernandez Garcia. The agreements give Automóviles Lamborghini Latinoamérica S.A. de C.V. the exclusive distributorship of Lamborghini vehicles and branded merchandise in Latin America and South America. Under the agreements, Automóviles Lamborghini is also allowed to manufacture Lamborghini vehicles and market them worldwide under the Lamborghini brand. Automóviles Lamborghini has produced two rebodied versions of the Diablo called the Eros and the Coatl. In 2015, Automóviles Lamborghini transferred the IP-rights to the Coatl foundation (chamber of commerce no. 63393700) in The Netherlands in order to secure these rights and to make them more marketable. The company has announced the production of a speedboat called the Lamborghini Glamour. Museo Lamborghini This two-storey museum is attached to the headquarters, and covers the history of Lamborghini cars and sport utility vehicles, showcasing a variety of modern and vintage models. The museum uses displays of cars, engines and photos to provide a history and review important milestones of Lamborghini. Museo Ferruccio Lamborghini A 9,000 square-foot museum about Ferruccio Lamborghini houses several cars, industrial prototypes, sketches, personal objects and family photos from Ferruccio's early life. See also List of automobile manufacturers of Italy Automotive industry in Italy Notes Citations References Corporate documents Alt URL External links Official website Lamborghini of Latinoamerica Official page Lamborghini Car Register Audi Companies based in the Metropolitan City of Bologna Formula One engine manufacturers Italian brands Italian racecar constructors Luxury motor vehicle manufacturers Marine engine manufacturers Sports car manufacturers Volkswagen Group 1963 establishments in Italy Vehicle manufacturing companies established in 1963 Car brands Engine manufacturers of Italy	[ 0.1207926943898201, 0.3241637349128723, -0.1165875568985939, -0.05473154038190842, -0.23089587688446045, 0.30119621753692627, 0.41083160042762756, -0.26851141452789307, -0.4607410728931427, -0.3790014386177063, 0.1645636111497879, -0.08930952847003937, -0.009111971594393253, 0.740880012512...
18272	https://en.wikipedia.org/wiki/LaGrand%20case	LaGrand case	The LaGrand case was a legal action heard before the International Court of Justice (ICJ) which concerned the Vienna Convention on Consular Relations. In the case, the ICJ ruled that its own temporary court orders were legally binding and that the rights contained in the convention could not be denied by the application of domestic legal procedures. Background On January 7, 1982, brothers Karl-Heinz LaGrand (1963–1999) and Walter Bernhard LaGrand (1962–1999) bungled an armed bank robbery in Marana, Arizona, United States, killing 63-year-old Kenneth Hartsock by stabbing him 24 times with a letter opener, and severely injuring 20-year-old Dawn Lopez by stabbing her multiple times. Lopez later said she heard one of the brothers twice say "Just make sure he's dead." They were subsequently charged and convicted of murder and sentenced to death. The LaGrands also had prior convictions for robbery and burglary, which were used against them during the sentencing phase of their trials. The LaGrands were German nationals, having been born from a German mother in Germany. While they had both lived in the United States since they were four and five, respectively, neither had obtained U.S. citizenship. As foreigners, the LaGrands should have been informed of their right to consular assistance, under the Vienna Convention, from their state of nationality, Germany. However, the Arizona authorities failed to do this. The brothers later contacted Consul William Behrens, head of the German Consulate in Phoenix, on their own accord, having learned of their right to consular assistance. They appealed their sentences and convictions on the grounds that they were not informed of their right to consular assistance, and that with consular assistance they might have been able to mount a better defense. The federal courts rejected their argument on grounds of procedural default, which provides that issues cannot be raised in federal court appeals unless they have first been raised in state courts. Diplomatic efforts, including pleas by German Ambassador Jürgen Chrobog and German Member of Parliament Claudia Roth, and the recommendation of Arizona's clemency board, failed to sway Arizona Governor Jane Dee Hull, who insisted that the executions be carried out. Karl LaGrand was subsequently executed by the state of Arizona on February 24, 1999, by lethal injection. Walter LaGrand was executed March 3, 1999, by lethal gas, and currently remains the last person executed by that method in the United States. The case Germany initiated legal action in the International Court of Justice against the United States regarding Walter LaGrand. Hours before Walter LaGrand was due to be executed, Germany applied for the Court to grant a provisional court order, requiring the United States to delay the execution of Walter LaGrand, which the court granted. Germany then initiated action in the U.S. Supreme Court for enforcement of the provisional order. In its judgment, the U.S. Supreme Court held that it lacked jurisdiction with respect to Germany's complaint against Arizona due to the Eleventh Amendment of the U.S. constitution, which prohibits federal courts from hearing lawsuits of foreign states against a U.S. state. With respect to Germany's case against the United States, it held that the doctrine of procedural default was not incompatible with the Vienna Convention, and that even if procedural default did conflict with the Vienna Convention it had been overruled by later federal law – the Antiterrorism and Effective Death Penalty Act of 1996, which explicitly legislated the doctrine of procedural default. (Subsequent federal legislation overrides prior self-executing treaty provisions, Whitney v. Robertson, ). The U.S. Solicitor General sent a letter to the Supreme Court, as part of these proceedings, arguing that provisional measures of the International Court of Justice are not legally binding. The United States Department of State also conveyed the ICJ's provisional measure to the Governor of Arizona without comment. The Arizona clemency board recommended a stay to the governor, on the basis of the pending ICJ case; but the Governor of Arizona ignored the recommendation. Germany then modified its complaint in the case before the ICJ, alleging furthermore that the U.S. violated international law by failing to implement the provisional measures. In opposition to the German submissions, the United States argued that the Vienna Convention did not grant rights to individuals, only to states; that the convention was meant to be exercised subject to the laws of each state party, which in the case of the United States meant subject to the doctrine of procedural default; and that Germany was seeking to turn the ICJ into an international court of criminal appeal. ICJ decision On June 27, 2001, the ICJ, rejecting all of the United States' arguments, ruled in favor of Germany. The ICJ held that the Vienna Convention on Consular Relations of April 24, 1963, granted rights to individuals on the basis of its plain meaning, and that domestic laws could not limit the rights of the accused under the convention, but only specify the means by which those rights were to be exercised. The ICJ also found that its own provisional measures were legally binding. The nature of provisional measures has been a subject of great dispute in international law; the English text of the Statute of the International Court of Justice implies they are not binding, while the French text implies that they are. Faced with a contradiction between two equally authentic texts of the statute, the court considered which interpretation better served the objects and purposes of the statute, and hence found that they are binding. This was the first time in the court's history it had ruled as such. The court also found that the United States violated the Vienna Convention through its application of procedural default. The court was at pains to point out that it was not passing judgment on the doctrine itself, but only its application to cases involving the Vienna Convention. See also Capital punishment in Arizona List of people executed in Arizona Avena case Leal Garcia v. Texas (2011) Linda Carty List of United States Supreme Court cases, volume 526 References External links Judgments of the International Court of Justice Judgment of U.S. Supreme Court, Federal Republic of Germany vs. United States ASIL Insight article on LaGrand case Federal Republic of Germany v. United States, 526 U.S. 111 (1999) The opinion by the Supreme Court in the matter referenced in the article. Stewart v. LaGrand, 526 U.S. 115 (1999) The Companion Case Breard v. Greene, 523 U.S. 317 (1997) The earlier case of the execution of a Paraguayan on which the LaGrand decisions rest. Capital punishment in Arizona United States Supreme Court case articles without infoboxes United States Supreme Court cases International Court of Justice cases 1999 in case law 2001 in case law 2001 in Germany 2001 in the United States LaGrand Germany–United States relations 2001 in international relations History of Pima County, Arizona Diplomatic immunity and protection treaties United States Supreme Court cases of the Rehnquist Court	[ 0.027375759556889534, 0.3003094494342804, -0.27711230516433716, -0.32097354531288147, 0.03514184430241585, 0.30992573499679565, -0.30360114574432373, 0.063423752784729, -0.17994415760040283, 0.05814095959067345, -0.4239283800125122, 0.3654862344264984, -0.18600592017173767, 0.5662106871604...
18273	https://en.wikipedia.org/wiki/Lotus%201-2-3	Lotus 1-2-3	Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software (later part of IBM). It was the first killer application of the IBM PC, was hugely popular in the 1980s, and significantly contributed to the success of IBM PC-compatibles. The first spreadsheet, VisiCalc, had helped launch the Apple II as one of the earliest personal computers in business use. With IBM's entry into the market, VisiCalc was slow to respond, and when they did, they launched what was essentially a straight port of their existing system despite the greatly expanded hardware capabilities. Lotus's solution was marketed as a three-in-one integrated solution: it handled spreadsheet calculations, database functionality, and graphical charts, hence the name "1-2-3", though how much database capability the product actually had was debatable, given the sparse memory left over after launching 1-2-3. It quickly overtook VisiCalc, as well as Multiplan and SuperCalc, the two VisiCalc competitors. 1-2-3 was the spreadsheet standard throughout the 1980s and into the 1990s, part of an unofficial set of three stand-alone office automation products that included dBase and WordPerfect, to build a complete business platform. With the acceptance of Windows 3.0, the market for desktop software grew even more. None of the major spreadsheet developers had seriously considered the graphical user interface (GUI) to supplement their DOS offerings, and so they responded slowly to Microsoft's own GUI-based products Excel and Word. Lotus was surpassed by Microsoft in the early 1990s, and never recovered. IBM purchased Lotus in 1995, and continued to sell Lotus offerings, only officially ending sales in 2013. History VisiCalc VisiCalc was launched in 1979 on the Apple II and immediately became a best-seller. Compared to earlier programs, VisiCalc allowed one to easily construct free-form calculation systems for practically any purpose, the limitations being primarily memory and speed related. The application was so compelling that there were numerous stories of people buying Apple II machines to run the program (see article Killer application). VisiCalc's runaway success on the Apple led to direct bug compatible ports to other platforms, including the Atari 8-bit family, Commodore PET and many others. This included the IBM PC when it launched in 1981, where it quickly became another best-seller, with an estimated 300,000 sales in the first six months on the market. There were well known problems with VisiCalc, and several competitors appeared to address some of these issues. One early example was 1980's SuperCalc, which solved the problem of circular references, while a slightly later example was Microsoft Multiplan from 1981, which offered larger sheets and other improvements. In spite of these, and others, VisiCalc continued to outsell them all. Beginnings The Lotus Development Corporation was founded by Mitchell Kapor, a friend of the developers of VisiCalc. 1-2-3 was originally written by Jonathan Sachs, who had written two spreadsheet programs previously while working at Concentric Data Systems, Inc. To aid its growth both in the UK and possibly elsewhere, Lotus 1-2-3 became the very first computer software to use television consumer advertising. Kapor was primarily a marketing guru. His ability to develop his product to appeal to non-technical users was one secret to its rapid success. Unlike many technologists, Kapor relied on focus group feedback to make his user instructions more user-friendly. One example: the instructions that came with the floppy disc read: "Remove the protective cover and insert disc into computer." A few focus group participants tried to rip-off the stiff plastic envelope of disc carrier. Kapor's recognition that techno-speak instructions needed to be translated to normative English was a strong contributor to the product's popularity. Lotus 1-2-3 was released on 26 January 1983, and immediately overtook Visicalc in sales. Unlike Microsoft Multiplan, it stayed very close to the model of VisiCalc, including the "A1" letter and number cell notation, and slash-menu structure. It was cleanly programmed, relatively bug-free, gained speed from being written completely in x86 assembly language (this remained the case for all DOS versions until 3.0, when Lotus switched to C) and wrote directly to video memory rather than use the slow DOS and/or BIOS text output functions. Among other novelties that Lotus introduced was a graph maker that could display several forms of graphs (including pie charts, bar graphics, or line charts) but required the user to have a graphics card. At this early stage, the only video boards available for the PC were IBM's Color/Graphics Adapter and Monochrome Display and Printer Adapter, the latter not supporting any graphics. However, because the two video boards used different RAM and port addresses, both could be installed in the same machine and so Lotus took advantage of this by supporting a "split" screen mode whereby the user could display the worksheet portion of 1-2-3 on the sharper monochrome video and the graphics on the CGA display. The initial release of 1-2-3 supported only three video setups: CGA, MDA (in which case the graph maker was not available) or dual-monitor mode. However, a few months later support was added for Hercules Computer Technology's Hercules Graphics Adapter which was a clone of the MDA that allowed bitmap mode. The ability to have high-resolution text and graphics capabilities (at the expense of color) proved extremely popular and Lotus 1-2-3 is credited with popularizing the Hercules graphics card. Subsequent releases of Lotus 1-2-3 supported more video standards as time went on, including EGA, AT&T/Olivetti, and VGA. Significantly, support for the PCjr/Tandy modes was never added and users of those machines were limited to CGA graphics. The early versions of 1-2-3 also had a key disk copy protection. While the program was hard disk installable, the user had to insert the original floppy disk when starting 1-2-3 up. This protection scheme was easily cracked and a minor inconvenience for home users, but proved a serious nuisance in an office setting. Starting with Release 3.0, Lotus no longer used copy protection. However, it was then necessary to "initialize" the System disk with one's name and company name so as to customize the copy of the program. Release 2.2 and higher had this requirement. This was an irreversible process unless one had made an exact copy of the original disk so as to be able to change names to transfer the program to someone else. The reliance on the specific hardware of the IBM PC led to 1-2-3 being utilized as one of the two stress test applications, along with Microsoft Flight Simulator, for true 100% compatibility when PC clones appeared in the early 1980s. 1-2-3 required two disk drives and at least 192K of memory, which made it incompatible with the IBM PCjr; Lotus produced a version for the PCjr that was on two cartridges but otherwise identical. By early 1984 the software was a killer app for the IBM PC and compatibles, while hurting sales of computers that could not run it. "They're looking for 1-2-3. Boy, are they looking for 1-2-3!" InfoWorld wrote. Noting that computer purchasers did not want PC compatibility as much as compatibility with certain PC software, the magazine suggested "let's tell it like it is. Let's not say 'PC compatible,' or even 'MS-DOS compatible.' Instead, let's say '1-2-3 compatible.'" PC clones' advertising did often prominently state that they were compatible with 1-2-3. An Apple II software company promised that its spreadsheet had "the power of 1-2-3". Because spreadsheets use large amounts of memory, 1‐2‐3 helped popularize greater RAM capacities in PCs, and especially the advent of expanded memory, which allowed greater than 640k to be accessed. Rivals Lotus 1-2-3 inspired imitators, the first of which was Mosaic Software's "The Twin", written in the fall of 1985 largely in the C language, followed by VP-Planner, which was backed by Adam Osborne. These were able to not only read 1-2-3 files, but also execute many or most macro programs by incorporating the same command structure. Copyright law had first been understood to only cover the source code of a program. After the success of lawsuits which claimed that the very "look and feel" of a program were covered, Lotus sought to ban any program which had a compatible command and menu structure. Program commands had not been considered to be covered before, but the commands of 1-2-3 were embedded in the words of the menu displayed on the screen. 1-2-3 won its 3-year long court battle against Paperback Software International and Mosaic Software Inc. in 1990. However, when it sued Borland over its Quattro Pro spreadsheet in Lotus v. Borland, a 6-year battle that ended at the Supreme Court in 1996, the final ruling appeared to support narrowing the applicability of copyright law to software; this is because the lower court's decision that it was not a copyright violation to merely have a compatible command menu or language was upheld, but only via stalemate. In 1995, the First Circuit found that command menus are an uncopyrightable "method of operation" under section 102(b) of the Copyright Act. The 1-2-3 menu structure (example, slash File Erase) was itself an advanced version of single letter menus introduced in VisiCalc. When the case came before the Supreme Court, the justices would end up deadlocked 4-4. This meant that Borland had emerged victorious, but the extent to which copyright law would be applicable to computer software went unaddressed and undefined. Decline Microsoft's early spreadsheet Multiplan eventually gave way to Excel, which debuted on the Macintosh in 1985. It arrived on PCs with the release of Windows 2.x in 1987, but as Windows was not yet popular, it posed no serious threat to Lotus's stranglehold on spreadsheet sales. However, Lotus suffered technical setbacks in this period. Version 3 of Lotus 1-2-3, fully converted from its original macro assembler to the more portable C language, was delayed by more than a year as the totally new 1-2-3 had to be made portable across platforms and fully compatible with existing macro sets and file formats. The inability to fit the larger code size of compiled C into lower-powered machines forced the company to split its spreadsheet offerings, with 1-2-3 release 3 only for higher-end machines, and a new version 2.2, based on the 2.01 assembler code base, available for PCs without extended memory. By the time these versions were released in 1989, Microsoft had eroded much of Lotus's market share. During the early 1990s, Windows grew in popularity, and along with it, Excel, which gradually displaced Lotus from its leading position. A planned total revamp of 1-2-3 for Windows fell apart, and all that the company could manage, was a Windows adaptation of their existing spreadsheet with no changes except using a graphical interface. Additionally, several versions of 1-2-3 had different features and slightly different interfaces. 1-2-3's intended successor, Lotus Symphony, was Lotus's entry into the anticipated "integrated software" market. It intended to expand the rudimentary all-in-one 1-2-3 into a fully-fledged spreadsheet, graph, database and word processor for DOS, but none of the integrated packages ever really succeeded. 1-2-3 migrated to the Windows platform, as part of Lotus SmartSuite. IBM's continued development and marketing of Lotus SmartSuite and OS/2 during the 1990s placed it in direct competition with Microsoft Office and Microsoft Windows, respectively. As a result, Microsoft "punished the IBM PC Company with higher prices, a late license for Windows 95, and the withholding of technical and marketing support." Microsoft did not grant IBM the OEM rights for Windows 95 until 15 minutes prior to the release of Windows 95 on 24 August 1995. Because of this uncertainty, IBM machines were sold without Windows 95, while Compaq, HP, and other companies sold machines with Windows 95 from day one. On 11 June 2013, IBM announced it would withdraw the Lotus brand: IBM Lotus 1-2-3 Millennium Edition V9.x, IBM Lotus SmartSuite 9.x V9.8.0, and Organizer V6.1.0. IBM stated, "Customers will no longer be able to receive support for these offerings after 30 September 2014. No service extensions will be offered. There will be no replacement programs." User features The name "1-2-3" stemmed from the product's integration of three main capabilities: along with its core spreadsheet functionality, 1-2-3 also offered integral charting/graphing and rudimentary database operations. Data features included sorting data in any defined rectangle, by order of information in one or two columns in the rectangular area. Justifying text in a range into paragraphs allowed it to be used as a primitive word processor. It had keyboard-driven pop-up menus as well as one-key commands, making it fast to operate. It was also user-friendly, introducing an early instance of context-sensitive help accessed by the F1 key. Macros in version one and add-ins (introduced in version 2.0) contributed much to 1-2-3's popularity, allowing dozens of outside vendors to sell macro packages and add-ins ranging from dedicated financial worksheets like F9 to full-fledged word processors. In the single-tasking MS-DOS, 1-2-3 was sometimes used as a complete office suite. All major graphics standards were supported; initially CGA and Hercules, and later EGA, AT&T, and VGA. Early versions used the filename extension "WKS". In version 2.0, the extension changed first to "WK1", then "WK2". This later became "WK3" for version 3.0 and "WK4" for version 4.0. Version 2 introduced macros with syntax and commands similar in complexity to an advanced BASIC interpreter, as well as string variable expressions. Later versions supported multiple worksheets and were written in C. The charting/graphing routines were written in Forth by Jeremy Sagan (son of Carl Sagan) and the printing routines by Paul Funk (founder of Funk Software). PC version history DOS Real Mode (8088+) These editions of 1-2-3 for DOS were primarily written in x86 assembly language. Release 1 was the first release for DOS-based PCs. Introduced in January 1983. Release 1A in April 1983 Officially supported ASCII, unofficially supported the IBM extended character set (but not LICS). Release 2 brought add-in support, better memory management and expanded memory support, supported x87 math coprocessors, and introduced support for the Lotus International Character Set (LICS). Introduced in September 1985. The Japanese version Lotus 1-2-3 Release 2J for NEC PC-98 computers was released on 1986-09-05. Release 2.01 in July 1986. Introduced an option to switch between LICS and the IBM extended character set. The Japanese version Lotus 1-2-3 Release 2.1J for NEC PC-98 computers was released in October 1987. A version Lotus 1-2-3 Release 2.1J+ followed in February 1989. Release 2.2 brought improved speed, automated macro tools, and presentation-quality graphics. Introduced in 1989. The Japanese version Lotus 1-2-3 Release 2.2J was released in February 1990. Release 2.3 brought WYSIWYG editing to the 2.x line. Introduced in 1991. The Japanese version Lotus 1-2-3 Release 2.3J was released in September 1991. Release 2.4 added icons and additional tools, and was the last release supporting 2D (only) spreadsheets. Introduced in 1992. The Japanese version Lotus 1-2-3 Release 2.4J was released in September 1993. In July 1995, Lotus released Lotus 1-2-3 Release 2.5J for DOS. Protected Mode (80286+) These editions of 1-2-3 for DOS were primarily written in C. Release 3 introduced the concept of 3D spreadsheets, utilized extended memory, supported having multiple files open simultaneously, and required an 80286-based PC or higher. It also introduced support for the Lotus Multi-Byte Character Set (LMBCS). Introduced in March 1989. Releases 3.1 and 3.1+ added WYSIWYG capabilities, the ability to swap to disk allowing for larger files (up to 64 MB), and could be run as a DOS program under Windows 3.0 and OS/2. Introduced in 1990. Release 3.4 added icons, improved performance, and enhanced graph capabilities, making it functionally similar to Release 2.4. Introduced in 1992. Lotus 1-2-3 for Home, 1992 Release 4 was the last release for DOS. More an upgrade to Release 3.4 than in line with Release 3 for Windows, it contains an improved interface and new features, including Version Manager, a spell checker, context-sensitive help, and cell comments. Introduced in May 1994. OS/2 Lotus 1-2-3/G Release 1. OS/2 text mode application introduced support for the Lotus Multi-Byte Character Set (LMBCS) together with the Release 3.0 for DOS in summer 1989. Release 1.1. Introduced in 1991. Release 2. Introduced in 1992. Release 2.1. Introduced in 1994. Windows Win16 (Windows 3.x) Lotus 1-2-3/W Release 1 was the first release for Windows, requiring Windows 3.0 or higher, was 16-bit, and was functionally equivalent to Release 3.x for DOS. Introduced in 1991. The Japanese version Lotus 1-2-3/Windows R1.0J was released on 1991-11-15. The version Lotus 1-2-3/Windows R1.1J was released on 1992-6-2. Release 4 was an extensive improvement that added groupware capabilities, improved integration with Lotus Notes, advanced graphics, context-sensitive menus and icons, and in-cell editing. Introduced in June 1993. A Japanese Lotus 1-2-3/Windows Release 4J was released 1993-07-16. Release 5 added additional groupware capabilities, chart maps, and improved database access. This was the last 16-bit version for Windows 3.1x, and was available as part of SmartSuite 3.1, 4, and 4.5. Introduced in mid-1994. The Japanese version Lotus 1-2-3/Windows Release 5J was released on 1994-09-22. Win32 (Windows 9x/NT) The 97 Edition was the first 32-bit version, requiring Windows 95 or Windows NT 4.0, and had a changed interface and support for LotusScript. Introduced in 1997. The Japanese-language version Lotus 1-2-3 97J was released on 1997-04-11. The Japanese-language Lotus 1-2-3 98J was released on 1998-06-05, followed by Lotus 1-2-3 2000J on 1999-07-02, and by Lotus 1-2-3 2001J on 2001-07-27. The Millennium Edition (version 9.8) contained new functions, improved Y2K support, Internet support, and better Excel compatibility. This is the last version of 1-2-3 for any platform, and has received maintenance releases through Fixpack 2. Introduced in 2002. Other operating systems DeskMate Introduced in 1989, "Lotus Spreadsheet for DeskMate", which was not officially called "1-2-3", supported 1-2-3 version 2.x files, and used windows, on-screen symbols, pull-down menus, dialog boxes and other graphical tools, similar to Microsoft Windows. However, it did not support add-ins, macros, or expanded memory. Unix A single version for Unix System V/386 was released in 1990. It was certified for SCO Xenix 2.3 and SCO Unix 3.2.0, but also expected to work on AT&T's plain System V and on ISC's 386/ix. SunOS / Solaris At least three releases for SPARC-based systems were published. Release 1.1 supported both SunView and the OpenWindows / OPEN LOOK windowing systems. It also featured real-time update support. Introduced in 1991. Release 1.2 supported "Classic" in xterm, "Classic" in X Window, OPEN LOOK, and OSF/Motif. OpenVMS A character cell terminal version of Lotus 1-2-3 was available on OpenVMS. HP MS-DOS palmtop PCs A joint collaboration between Hewlett Packard and Lotus, the HP 95LX, HP 100LX, HP 200LX and HP OmniGo 700LX (1991–1994) had ports of Lotus 1-2-3 R2.2 and R2.4 embedded in ROM. Apple Macintosh Lotus's first truly WYSIWYG spreadsheet, taking full advantage of the Mac OS, had two releases: Release 1.0 debuted in 1991 and Release 1.1 was introduced the following year. Lotus 1-2-3 for Macintosh 1.0 received a 4 mice rating (out of 5) in the March 1992 issue of MacUser, praising it for being the first spreadsheet on Macintosh to include in-cell editing instead of using the formula bar found in competing products, as well as other interface refinements. The user interface provided Macintosh users the advanced charting capabilities of the PC version with a Macintosh user interface, while also offering a "classic" keyboard driven user interface familiar to the users of the DOS version, giving it a mice rating (out of 5). In 1987, Lotus announced a mainframe version of Lotus 1-2-3, Lotus 1-2-3/M; 1-2-3/M was designed for use with IBM 3270 terminals and ran under both VM/CMS and MVS operating systems. Lotus 1-2-3/M was jointly developed by IBM and Lotus, and exclusively sold by IBM. File Formats Lotus 1-2-3 file formats use various filename extensions including 123, wks, wk1, wk2, wk3, wk4, some of these may open in the desktop applications of Collabora Online, LibreOffice and Apache OpenOffice, these can then be saved into the OpenDocument format or other file formats. Reception After previewing 1-2-3 on the IBM PC in 1982, BYTE called it "modestly revolutionary" for elegantly combining spreadsheet, database, and graphing functions. It praised the application's speed and ease of use, stating that with the built-in help screens and tutorial, "1-2-3 is one of the few pieces of software that can literally be used by anybody. You can buy 1-2-3 and [an IBM PC] and be running the two together the same day". PC Magazine in 1983 called 1-2-3 "a powerful and impressive program ... as a spreadsheet, it's excellent", and attributed its very fast performance to being written in assembly language. See also As-Easy-As Comparison of office suites Compose key sequence Reverse Polish Notation (RPN in formulas) Microsoft Works References External links . . . . . . . . . . . 1983 software Discontinued software DOS software 1-2-3 1-2-3 OS/2 software Assembly language software Spreadsheet software Spreadsheet software for Windows	[ -0.527229905128479, 0.0007923120865598321, -0.2528087794780731, 0.02877877652645111, -0.571186363697052, 0.2173088788986206, -0.13556812703609467, -0.2939527630805969, -0.18999771773815155, 0.14272034168243408, -0.13014651834964752, 0.19059590995311737, -0.5021200776100159, -0.314381301403...
18274	https://en.wikipedia.org/wiki/List%20of%20memorials%20to%20Lyndon%20B.%20Johnson	List of memorials to Lyndon B. Johnson	This is a list of memorials to Lyndon B. Johnson, the 36th president of the United States. Buildings Lyndon B. Johnson Student Center, a complex including teaching theaters, shops, a student pool hall, and office space located at the Texas State University in San Marcos, Texas; President Johnson's college alma mater. Lyndon B. Johnson Tropical Medical Center, a hospital in American Samoa Lyndon B. Johnson General Hospital, part of Harris Health System in Houston, Texas Lyndon B. Johnson Space Center in Houston, Texas Lyndon Baines Johnson Department of Education Building, in Washington, D.C. Lyndon Baines Johnson Library and Museum, presidential museum in Austin, Texas Military vessels USS Lyndon B. Johnson (DDG-1002) Parks and topographical features Lyndon B. Johnson National Historical Park, Johnson City, Texas Lake Lyndon B. Johnson, a lake in Texas Lyndon B. Johnson National Grassland, in Texas Lyndon Baines Johnson Memorial Grove on the Potomac, in Washington, D.C. FELDA L.B. Johnson, a village settlement in Negeri Sembilan, Malaysia. Roads Lyndon B. Johnson Freeway (Interstate 635), a freeway in Dallas, Texas Schools Lyndon B. Johnson Elementary School in Jackson, Kentucky Lyndon B. Johnson High School (Austin, Texas) Lyndon B. Johnson High School (Johnson City, Texas) Lyndon B. Johnson High School (Laredo, Texas) Lyndon B. Johnson Middle School in Melbourne, Florida Lyndon B. Johnson School of Public Affairs, a public affairs graduate school at the University of Texas at Austin Johnson Elementary in Bryan, Texas Johnson, Lyndon Memorials Johnson, Lyndon	[ -0.2268744856119156, 1.1079410314559937, -0.9317676424980164, 0.16532732546329498, -0.6366204023361206, 0.6635693907737732, 0.5125850439071655, 0.2977256178855896, -0.7212458252906799, -0.2860211133956909, -0.13405995070934296, -0.1823866069316864, -0.3955151438713074, 0.44368332624435425,...
18278	https://en.wikipedia.org/wiki/Liberation%20Day%20%28Netherlands%29	Liberation Day (Netherlands)	Liberation Day () is a public holiday in the Netherlands celebrated each year on 5 May to mark the end of the occupation by Nazi Germany during World War II. It follows the Remembrance of the Dead (Dodenherdenking) on 4 May. The nation was liberated by Canadian forces, British infantry divisions, the British I Corps, the 1st Polish Armoured Division, American, Belgian, Dutch and Czechoslovak troops. Parts of the country, in particular the south-east, were liberated by the British Second Army which included American and Polish airborne forces (see Operation Market Garden) and French airbornes (see Operation Amherst). On 5 May 1945, at Hotel de Wereld in Wageningen, I Canadian Corps commander Lieutenant-General Charles Foulkes and Oberbefehlshaber Niederlande commander-in-chief Generaloberst Johannes Blaskowitz reached an agreement on the capitulation of all German forces in the Netherlands. The capitulation document was signed the next day (no typewriter had been available the prior day) in the auditorium of Wageningen University, located next door. After liberation in 1945, Liberation Day was celebrated every five years. In 1990 the day was declared a national holiday when liberation would be remembered and celebrated every year. Festivals are held in most places in the Netherlands with parades of veterans and musical festivals throughout the whole country. See also Battle of the Netherlands Liberation of the Netherlands Liberation Day Liberation of Arnhem Victory in Europe Day External links Nationaal Comité 4 en 5 mei WWII: Liberation of the Netherlands - Canada at War 1st Polish armoured division liberating Netherlands 4th Canadian armoured division liberating Netherlands Dutch society May observances National days Wageningen History of Wageningen L Annual events in the Netherlands Spring (season) events in the Netherlands	[ 0.26611432433128357, -0.17751462757587433, 0.030728153884410858, -0.8354551792144775, -0.1634182184934616, 0.19496986269950867, 0.5785938501358032, 0.27070149779319763, -0.4324738383293152, 0.1451665461063385, -0.4371376037597656, 0.03679189831018448, 0.02553275227546692, 0.220189377665519...
18279	https://en.wikipedia.org/wiki/Light%20pollution	Light pollution	Light pollution is the presence of unwanted, inappropriate, or excessive artificial lighting. In a descriptive sense, the term "light pollution" refers to the effects of any poorly implemented lighting, during the day or night. These effects can be found as an issue throughout the levels of our societies, impacting all the way from the individual level, such as from an unwanted blinking light on a consumer product, to a community level, as when a new urban development affects existing communities through its poorly planned street lighting. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution. Although this type of pollution can exist throughout the day, its effects are magnified during the night with the contrast of darkness. It has been estimated that 83 percent of the world's people live under light-polluted skies and that 23 percent of the world's land area is affected by skyglow. The area affected by artificial illumination continues to increase. A major side-effect of urbanization, light pollution is blamed for compromising health, disrupting ecosystems, and spoiling aesthetic environments. Solutions to light pollution are often easy steps like adjusting light fixtures or using more appropriate lightbulbs. However, because it is a human-made phenomenon, addressing its impacts on humans and the wider ecological systems of Earth involves vast societal complexities that overlay light pollution with political, social, and economic considerations. Definitions Light pollution is the presence of anthropogenic artificial light in otherwise dark conditions. The term is most commonly used in relation to in the outdoor environment and surrounding, but is also used to refer to artificial light indoors. Adverse consequences are multiple; some of them may not be known yet. Light pollution competes with starlight in the night sky for urban residents, interferes with astronomical observatories, and, like any other form of pollution, disrupts ecosystems and has adverse health effects. Light pollution is a side-effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, outdoor area lighting (such as car parks), offices, factories, streetlights, and illuminated sporting venues. It is most severe in highly industrialized, densely populated areas of North America, Europe, and Asia and in major cities in the Middle East and North Africa like Tehran and Cairo, but even relatively small amounts of light can be noticed and create problems. Awareness of the deleterious effects of light pollution began in the second half of the 19th century, but efforts to address effects did not begin until the 1950s. In the 1980s a global dark-sky movement emerged with the founding of the International Dark-Sky Association (IDA). There are now such educational and advocacy organizations in many countries worldwide. Results Energy conservation advocates contend that light pollution must be addressed by changing the habits of society, so that lighting is used more efficiently, with less waste and less creation of unwanted or unneeded illumination. Several industry groups also recognize light pollution as an important issue. For example, the Institution of Lighting Engineers in the United Kingdom provides its members with information about light pollution, the problems it causes, and how to reduce its impact. Although, recent research point that the energy efficiency is not enough to reduce the light pollution because of the rebound effect. Since people may disagree over whether any particular lighting source is irritating or how important its effects on non-human life are, it is common for one person to consider as light pollution something that another finds desirable. One example is found in advertising, when an advertiser wishes for particular lights to be bright and visible while others find them annoying. Other types of light pollution are less disputed. For instance, light that accidentally crosses a property boundary and annoys a neighbour is generally considered wasted and pollutive. For this reason and others, decisions about how to manage artificial light are often marked by disputes. Differences of opinion over what light is reasonable and who should have authority and responsibility sometimes make it necessary for parties to negotiate. Where it is desired that such decisions be supported by objective data, light levels can be quantified by field measurement or mathematical modeling, the results of which are typically rendered in isophote maps or light contour maps. To deal with light pollution, authorities have taken a variety of measures depending on the interests, beliefs, and understandings of the society involved. These measures range from doing nothing at all to implementing strict laws and regulations specifying how lights may be installed and used. Types Light pollution is caused by inefficient or unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, and skyglow. A single offending light source often falls into more than one of these categories. Light trespass Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbour's fence. A common light trespass problem occurs when a strong light enters the window of one's home from the outside, causing problems such as sleep deprivation. A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. To assist them, the International Dark-Sky Association has developed a set of model lighting ordinances. The Dark-Sky Association was started to reduce the light going up into the sky which reduces the visibility of stars (see Skyglow below). This is any light that is emitted more than 90° above nadir. By limiting light at this 90° mark they have also reduced the light output in the 80–90° range which creates most of the light trespass issues. U.S. federal agencies may also enforce standards and process complaints within their areas of jurisdiction. For instance, in the case of light trespass by white strobe lighting from communication towers in excess of FAA minimum lighting requirements the Federal Communications Commission maintains an Antenna Structure Registration database information which citizens may use to identify offending structures and provides a mechanism for processing citizen inquiries and complaints. The U.S. Green Building Council (USGBC) has also incorporated a credit for reducing the amount of light trespass and sky glow into their environmentally friendly building standard known as LEED. Light trespass can be reduced by selecting light fixtures that limit the amount of light emitted more than 80° above the nadir. The IESNA definitions include full cutoff (0%), cutoff (10%), and semi-cutoff (20%). (These definitions also include limits on light emitted above 90° to reduce sky glow.) Over-illumination Over-illumination is the excessive use of light. In the USA commercial building lighting consumes in excess of 81.68 terawatts (1999 data) of electricity, according to the DOE. Even among developed countries there are large differences in patterns of light use. American cities emit three to five times more light to space per capita compared to German cities. Over-illumination stems from several factors: Consensus-based standards or norms that are not based on vision science; Not using timers, occupancy sensors or other controls to extinguish lighting when not needed; Improper design, by specifying higher levels of light than needed for a given visual task; Incorrect choice of fixtures or light bulbs, which do not direct light into areas as needed; Improper selection of hardware to utilize more energy than needed to accomplish the lighting task; Incomplete training of building managers and occupants to use lighting systems efficiently; Inadequate lighting maintenance resulting in increased stray light and energy costs; "Daylight lighting" demanded by citizens to reduce crime or by shop owners to attract customers; Substitution of old lamps with more efficient LEDs using the same electrical power; and Indirect lighting techniques, such as illuminating a vertical wall to bounce light onto the ground. Most of these issues can be readily corrected with available, inexpensive technology, and with the resolution of landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly, public awareness would need to improve for industrialized countries to realize the large payoff in reducing over-illumination. In certain cases, an over-illumination lighting technique may be needed. For example, indirect lighting is often used to obtain a "softer" look, since hard direct lighting is generally found less desirable for certain surfaces, such as skin. The indirect lighting method is perceived as cozier and suits bars, restaurants, and living quarters. It is also possible to block the direct lighting effect by adding softening filters or other solutions, though intensity will be reduced. Glare Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies, as follows: Blinding glare describes effects such as that caused by staring into the Sun. It is completely blinding and leaves temporary or permanent vision deficiencies. Disability glare describes effects such as being blinded by oncoming car lights, or light scattering in fog or in the eye, reducing contrast, as well as reflections from print and other dark areas that render them bright, with a significant reduction in sight capabilities. Discomfort glare does not typically cause a dangerous situation in itself, though it is annoying and irritating at best. It can potentially cause fatigue if experienced over extended periods. According to Mario Motta, president of the Massachusetts Medical Society, "...glare from bad lighting is a public-health hazard—especially the older you become. Glare light scattering in the eye causes loss of contrast and leads to unsafe driving conditions, much like the glare on a dirty windshield from low-angle sunlight or the high beams from an oncoming car." In essence bright and/or badly shielded lights around roads can partially blind drivers or pedestrians and contribute to accidents. The blinding effect is caused in large part by reduced contrast due to light scattering in the eye by excessive brightness, or to the reflection of light from dark areas in the field of vision, with luminance similar to the background luminance. This kind of glare is a particular instance of disability glare, called veiling glare. (This is not the same as loss of accommodation of night vision which is caused by the direct effect of the light itself on the eye.) Light clutter Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertisements surround the roadways. Depending on the motives of the person or organization that installed the lights, their placement and design can even be intended to distract drivers, and can contribute to accidents. From satellites Another source of light pollution are artificial satellites. With future increase in numbers of satellite constellations, like OneWeb and Starlink, it is feared especially by the astronomical community, such as the IAU that light pollution will increase significantly, beside other problems of satellite overcrowding. Public discourse surrounding the anticipated growth of satellite constellation, like OneWeb and Starlink, includes multiple petitions by astronomers and citizen scientists, and has raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight. Measurement Issues to measuring light pollution Measuring the effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light and illumination from the Moon. This is caused by two main sources: airglow and scattered light. At high altitudes, primarily above the mesosphere, there is enough UV radiation from the sun at very short wavelengths to cause ionization. When the ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow. The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the Earth's shadow. Lower in the atmosphere all the solar photons with energies above the ionization potential of N2 and O2 have already been absorbed by the higher layers and thus no appreciable ionization occurs. Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the Milky Way, but also the zodiacal light, sunlight that is reflected and backscattered from interplanetary dust particles. The amount of airglow and zodiacal light is quite varied (depending, amongst other things on sunspot activity and the Solar cycle) but given optimal conditions, the darkest possible sky has a brightness of about 22 magnitude/square arc second. If a full moon is present, the sky brightness increases to about 18 magnitude/sq. arcsecond depending on local atmospheric transparency, 40 times brighter than the darkest sky. In densely populated areas a sky brightness of 17 magnitude/sq. an arcsecond is not uncommon, or as much as 100 times brighter than is natural. Satellite imagery measuring To precisely measure how bright the sky gets, night time satellite imagery of the earth is used as raw input for the number and intensity of light sources. These are put into a physical model of scattering due to air molecules and aerosoles to calculate cumulative sky brightness. Maps that show the enhanced sky brightness have been prepared for the entire world. Bortle scale The Bortle scale is a nine-level measuring system used to track how much light pollution there is in the sky. Five or less is the amount required to see the Milky Way whilst one is "pristine", the darkest possible. Global impact Europe Inspection of the area surrounding Madrid reveals that the effects of light pollution caused by a single large conglomeration can be felt up to away from the center. Global effects of light pollution are also made obvious. Research in the late 1990s showed that entire area consisting of southern England, Netherlands, Belgium, West Germany, and northern France have a sky brightness of at least two to four times normal. The only places in continental Europe where the sky can attain its natural darkness are in northern Scandinavia and in islands far from the continent. North America In North America the situation is comparable. There is a significant problem with light pollution ranging from the Canadian Maritime Provinces to the American Southwest. The International Dark-Sky Association works to designate areas that have high-quality night skies. These areas are supported by communities and organizations that are dedicated to reducing light pollution (e.g. Dark-sky preserve). The National Park Service Natural Sounds and Night Skies Division has measured night sky quality in national park units across the U.S. Sky quality in the U.S. ranges from pristine (Capitol Reef National Park and Big Bend National Park) to severely degraded (Santa Monica Mountains National Recreation Area and Biscayne National Park). The National Park Service Night Sky Program monitoring database is available online (2015). East Asia Light pollution in Hong Kong was declared the 'worst on the planet' in March 2013. In June 2016, it was estimated that one third of the world's population could no longer see the Milky Way, including 80% of Americans and 60% of Europeans. Singapore was found to be the most light-polluted country in the world. Consequences Public health impact Medical research on the effects of excessive light on the human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue, medically defined stress, decrease in sexual function and increase in anxiety. Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety. For those who need to be awake at night, light at night also has an acute effect on alertness and mood. In 2007, "shift work that involves circadian disruption" was listed as a probable carcinogen by the World Health Organization's International Agency for Research on Cancer. (IARC Press release No. 180). Multiple studies have documented a correlation between night shift work and the increased incidence of breast and prostate cancer. One study which examined the link between exposure to artificial light at night (ALAN) and levels of breast cancer in South Korea found that regions which had the highest levels of ALAN reported the highest number of cases of breast cancer. Seoul, which had the highest levels of light pollution, had 34.4% more cases of breast cancer than Ganwon-do, which had the lowest levels of light pollution. This suggested a high correlation between ALAN and the prevalence of breast cancer. It was also found that there was no correlation between other types of cancer such as cervical or lung cancer and ALAN levels. A more recent discussion (2009), written by Professor Steven Lockley, Harvard Medical School, can be found in the CfDS handbook "Blinded by the Light?". Chapter 4, "Human health implications of light pollution" states that "...light intrusion, even if dim, is likely to have measurable effects on sleep disruption and melatonin suppression. Even if these effects are relatively small from night to night, continuous chronic circadian, sleep and hormonal disruption may have longer-term health risks". The New York Academy of Sciences hosted a meeting in 2009 on Circadian Disruption and Cancer. Red light suppresses melatonin the least. In June 2009, the American Medical Association developed a policy in support of control of light pollution. News about the decision emphasized glare as a public health hazard leading to unsafe driving conditions. Especially in the elderly, glare produces loss of contrast, obscuring night vision. A new 2021 study published in the Southern Economic Journal indicates that light pollution may increase by 13% in preterm births before 23 weeks of gestation. Ecological impact When artificial light affects organisms and ecosystems it is called ecological light pollution. While light at night can be beneficial, neutral, or damaging for individual species, its presence invariably disturbs ecosystems. For example, some species of spiders avoid lit areas, while other species are happy to build their spider web directly on a lamp post. Since lamp posts attract many flying insects, the spiders that don't mind light gain an advantage over the spiders that avoid it. This is a simple example of the way in which species frequencies and food webs can be disturbed by the introduction of light at night. Light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse animal navigation, alter competitive interactions, change predator-prey relations, and cause physiological harm. The rhythm of life is orchestrated by the natural diurnal patterns of light and dark, so disruption to these patterns impacts the ecological dynamics. Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia, from eating surface algae, causing algal blooms that can kill off the lakes' plants and lower water quality. Light pollution may also affect ecosystems in other ways. For example, entomologists have documented that nighttime light may interfere with the ability of moths and other nocturnal insects to navigate. It can also negative impact on insect development and reproduction. Night-blooming flowers that depend on moths for pollination may be affected by night lighting, as there is no replacement pollinator that would not be affected by the artificial light. This can lead to species decline of plants that are unable to reproduce, and change an area's longterm ecology. Among nocturnal insects, fireflies (Coleoptera: Lampyridae, Phengodidae and Elateridae) are especially interesting study objects for light pollution, once they depend on their own light to reproduce and, consequently, are very sensitive to environmental levels of light. Fireflies are well known and interesting to the general public (unlike many other insects) and are easily spotted by non-experts, and, due to their sensibility and rapid response to environmental changes good bioindicators for artificial night lighting. Significant declines in some insect populations have been suggested as being at least partially mediated by artificial lights at night. A 2009 study also suggests deleterious impacts on animals and ecosystems because of perturbation of polarized light or artificial polarization of light (even during the day, because direction of natural polarization of sun light and its reflection is a source of information for a lot of animals). This form of pollution is named polarized light pollution (PLP). Unnatural polarized light sources can trigger maladaptive behaviors in polarization-sensitive taxa and alter ecological interactions. Lights on tall structures can disorient migrating birds. Estimates by the U.S. Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from four to five million per year to an order of magnitude higher. The Fatal Light Awareness Program (FLAP) works with building owners in Toronto, Ontario, Canada and other cities to reduce mortality of birds by turning out lights during migration periods. Similar disorientation has also been noted for bird species migrating close to offshore production and drilling facilities. Studies carried out by Nederlandse Aardolie Maatschappij b.v. (NAM) and Shell have led to the development and trial of new lighting technologies in the North Sea. In early 2007, the lights were installed on the Shell production platform L15. The experiment proved a great success since the number of birds circling the platform declined by 50 to 90%. Birds migrate at night for several reasons. Save water from dehydration in hot day flying and part of the bird's navigation system works with stars in some way. With city light outshining the night sky, birds (and also about mammals) no longer navigate by stars. Sea turtle hatchlings emerging from nests on beaches are another casualty of light pollution. It is a common misconception that hatchling sea turtles are attracted to the moon. Rather, they find the ocean by moving away from the dark silhouette of dunes and their vegetation, a behavior with which artificial lights interfere. The breeding activity and reproductive phenology of toads, however, are cued by moonlight. Juvenile seabirds may also be disoriented by lights as they leave their nests and fly out to sea. Amphibians and reptiles are also affected by light pollution. Introduced light sources during normally dark periods can disrupt levels of melatonin production. Melatonin is a hormone that regulates photoperiodic physiology and behaviour. Some species of frogs and salamanders utilize a light-dependent "compass" to orient their migratory behaviour to breeding sites. Introduced light can also cause developmental irregularities, such as retinal damage, reduced juvenile growth, premature metamorphosis, reduced sperm production, and genetic mutation. In September 2009, the 9th European Dark-Sky Symposium in Armagh, Northern Ireland had a session on the environmental effects of light at night (LAN). It dealt with bats, turtles, the "hidden" harms of LAN, and many other topics. The environmental effects of LAN were mentioned as early as 1897, in a Los Angeles Times article. The following is an excerpt from that article, called "Electricity and English songbirds": In December 2021, the first global atlas highlighting potential impacts in the marine environment was published in Elementa Effect on astronomy Astronomy is very sensitive to light pollution. The night sky viewed from a city bears no resemblance to what can be seen from dark skies. Skyglow (the scattering of light in the atmosphere at night) reduces the contrast between stars and galaxies and the sky itself, making it much harder to see fainter objects. This is one factor that has caused newer telescopes to be built in increasingly remote areas. Even at apparent clear night skies, there can be a lot of stray light that becomes visible at longer exposure times in astrophotography. By means of software the stray light can be reduced, but at the same time object detail is getting lost in the images. The following picture of the area around the Pinwheel Galaxy (Messier 101) with the apparent magnitude of 7.5m with all stars down to an apparent magnitude of 10m was taken in Berlin in direction close to the zenith with a fast lens (f-number 1.2) and an exposure time of five seconds at an exposure index of ISO 12800: Some astronomers use narrow-band "nebula filters", which allow only specific wavelengths of light commonly seen in nebulae, or broad-band "light pollution filters", which are designed to reduce (but not eliminate) the effects of light pollution by filtering out spectral lines commonly emitted by sodium- and mercury-vapor lamps, thus enhancing contrast and improving the view of dim objects such as galaxies and nebulae. Unfortunately, these light pollution reduction (LPR) filters are not a cure for light pollution. LPR filters reduce the brightness of the object under study and this limits the use of higher magnifications. LPR filters work by blocking light of certain wavelengths, which alters the color of the object, often creating a pronounced green cast. Furthermore, LPR filters work only on certain object types (mainly emission nebulae) and are of little use on galaxies and stars. No filter can match the effectiveness of a dark sky for visual or photographic purposes. Light pollution affects the visibility of diffuse sky objects like nebulae and galaxies more than stars, due to their low surface brightness. Most such objects are rendered invisible in heavily light-polluted skies above major cities. A simple method for estimating the darkness of a location is to look for the Milky Way, which from truly dark skies appears bright enough to cast a shadow. In addition to skyglow, light trespass can impact observations when artificial light directly enters the tube of the telescope and is reflected from non-optical surfaces until it eventually reaches the eyepiece. This direct form of light pollution causes a glow across the field of view, which reduces contrast. Light trespass also makes it hard for a visual observer to become sufficiently adapted to the dark. The usual measures to reduce this glare, if reducing the light directly is not an option, include flocking the telescope tube and accessories to reduce reflection, and putting a light shield (also usable as a dew shield) on the telescope to reduce light entering from angles other than those near the target. Under these conditions, some astronomers prefer to observe under a black cloth to ensure maximum adaptation to the dark. Increase in atmospheric pollution A study presented at the American Geophysical Union meeting in San Francisco found that light pollution destroys nitrate radicals thus preventing the normal night time reduction of atmospheric smog produced by fumes emitted from cars and factories. The study was presented by Harald Stark from the National Oceanic and Atmospheric Administration. Reduction of natural sky polarization In the night, the polarization of the moonlit sky is very strongly reduced in the presence of urban light pollution, because scattered urban light is not strongly polarized. Polarized moonlight cannot be seen by humans, but is believed to be used by many animals for navigation. Reduction Reducing light pollution implies many things, such as reducing sky glow, reducing glare, reducing light trespass, and reducing clutter. The method for best reducing light pollution, therefore, depends on exactly what the problem is in any given instance. Possible solutions include: Utilizing light sources of minimum intensity necessary to accomplish the light's purpose. Turning lights off using a timer or occupancy sensor or manually when not needed. Improving lighting fixtures, so they direct their light more accurately towards where it is needed, and with fewer side effects. Adjusting the type of lights used, so the light waves emitted are those that are less likely to cause severe light pollution problems. Mercury, metal halide and above all first generation of blue-light LED road luminaires are much more polluting than sodium lamps: Earth's atmosphere scatters and transmits blue light better than yellow or red light. It is a common experience observing "glare" and "fog" around and below LED road luminaires as soon as air humidity increases, while orange sodium lamp luminaires are less prone to showing this phenomenon. Evaluating existing lighting plans, and re-designing some or all the plans depending on whether existing light is actually needed. Improving lighting fixtures The use of full cutoff lighting fixtures, as much as possible, is advocated by most campaigners for the reduction of light pollution. It is also commonly recommended that lights be spaced appropriately for maximum efficiency, and that number of luminaires being used as well as the wattage of each luminaire match the needs of the particular application (based on local lighting design standards). Full cutoff fixtures first became available in 1959 with the introduction of General Electric's M100 fixture. A full cutoff fixture, when correctly installed, reduces the chance for light to escape above the plane of the horizontal. Light released above the horizontal may sometimes be lighting an intended target, but often serves no purpose. When it enters into the atmosphere, light contributes to sky glow. Some governments and organizations are now considering, or have already implemented, full cutoff fixtures in street lamps and stadium lighting. The use of full cutoff fixtures helps to reduce sky glow by preventing light from escaping above the horizontal. Full cutoff typically reduces the visibility of the lamp and reflector within a luminaire, so the effects of glare are also reduced. Campaigners also commonly argue that full cutoff fixtures are more efficient than other fixtures, since light that would otherwise have escaped into the atmosphere may instead be directed towards the ground. However, full cutoff fixtures may also trap more light in the fixture than other types of luminaires, corresponding to lower luminaire efficiency, suggesting a re-design of some luminaires may be necessary. The use of full cutoff fixtures can allow for lower wattage lamps to be used in the fixtures, producing the same or sometimes a better effect, due to being more carefully controlled. In every lighting system, some sky glow also results from light reflected from the ground. This reflection can be reduced, however, by being careful to use only the lowest wattage necessary for the lamp, and setting spacing between lights appropriately. Assuring luminaire setback is greater than 90° from highly reflective surfaces also diminishes reflectance. A common criticism of full cutoff lighting fixtures is that they are sometimes not as aesthetically pleasing to look at. This is most likely because historically there has not been a large market specifically for full cutoff fixtures, and because people typically like to see the source of illumination. Due to the specificity with their direction of light, full cutoff fixtures sometimes also require expertise to install for maximum effect. The effectiveness of using full cutoff roadway lights to combat light pollution has also been called into question. According to design investigations, luminaires with full cutoff distributions (as opposed to cutoff or semi cutoff, compared here) have to be closer together to meet the same light level, uniformity and glare requirements specified by the IESNA. These simulations optimized the height and spacing of the lights while constraining the overall design to meet the IESNA requirements, and then compared total uplight and energy consumption of different luminaire designs and powers. Cutoff designs performed better than full cutoff designs, and semi-cutoff performed better than either cutoff or full cutoff. This indicates that, in roadway installations, over-illumination or poor uniformity produced by full cutoff fixtures may be more detrimental than direct uplight created by fewer cutoff or semi-cutoff fixtures. Therefore, the overall performance of existing systems could be improved more by reducing the number of luminaires than by switching to full cutoff designs. However, using the definition of "light pollution" from some Italian regional bills (i.e., "every irradiance of artificial light outside competence areas and particularly upward the sky") only full cutoff design prevents light pollution. The Italian Lombardy region, where only full cutoff design is allowed (Lombardy act no. 17/2000, promoted by Cielobuio-coordination for the protection of the night sky), in 2007 had the lowest per capita energy consumption for public lighting in Italy. The same legislation also imposes a minimum distance between street lamps of about four times their height, so full cut-off street lamps are the best solution to reduce both light pollution and electrical power usage. Adjusting types of light sources Several different types of light sources exist, each having a variety of properties that determine their appropriateness for different tasks. Particularly notable characteristics are efficiency and spectral power distribution. It is often the case that inappropriate light sources have been selected for a task, either due to ignorance or because more appropriate lighting technology was unavailable at the time of installation. Therefore, poorly chosen light sources often contribute unnecessarily to light pollution and energy waste. By updating light sources appropriately, it is often possible to reduce energy use and pollutive effects while simultaneously improving efficiency and visibility. Some types of light sources are listed in order of energy efficiency in the table below (figures are approximate maintained values), and include their visual skyglow impact, relative to LPS lighting. Many astronomers request that nearby communities use low-pressure sodium lights or amber Aluminium gallium indium phosphide LED as much as possible because the principal wavelength emitted is comparably easy to work around or in rare cases filter out. The low cost of operating sodium lights is another feature. In 1980, for example, San Jose, California, replaced all street lamps with low pressure sodium lamps, whose light is easier for nearby Lick Observatory to filter out. Similar programs are now in place in Arizona and Hawaii. Such yellow light sources also have significantly less visual skyglow impact, so reduce visual sky brightness and improve star visibility for everyone. Disadvantages of low-pressure sodium lighting are that fixtures must usually be larger than competing fixtures, and that color cannot be distinguished, due to its emitting principally a single wavelength of light (see security lighting). Due to the substantial size of the lamp, particularly in higher wattages such as 135 W and 180 W, control of light emissions from low-pressure sodium luminaires is more difficult. For applications requiring more precise direction of light (such as narrow roadways) the native lamp efficacy advantage of this lamp type is decreased and may be entirely lost compared to high pressure sodium lamps. Allegations that this also leads to higher amounts of light pollution from luminaires running these lamps arise principally because of older luminaires with poor shielding, still widely in use in the UK and in some other locations. Modern low-pressure sodium fixtures with better optics and full shielding, and the decreased skyglow impacts of yellow light preserve the luminous efficacy advantage of low-pressure sodium and result in most cases is less energy consumption and less visible light pollution. Unfortunately, due to continued lack of accurate information, many lighting professionals continue to disparage low-pressure sodium, contributing to its decreased acceptance and specification in lighting standards and therefore its use. Another disadvantage of low-pressure sodium lamps is that some people find the characteristic yellow light very displeasing aesthetically. Because of the increased sensitivity of the human eye to blue and green wavelengths when viewing low-luminances (the Purkinje effect) in the night sky, different sources produce dramatically different amounts of visible skyglow from the same amount of light sent into the atmosphere. Re-designing lighting plans In some cases, evaluation of existing plans has determined that more efficient lighting plans are possible. For instance, light pollution can be reduced by turning off unneeded outdoor lights, and lighting stadiums only when there are people inside. Timers are especially valuable for this purpose. One of the world's first coordinated legislative efforts to reduce the adverse effect of this pollution on the environment began in Flagstaff, Arizona, in the U.S. There, more than three decades of ordinance development has taken place, with the full support of the population, often with government support, with community advocates, and with the help of major local observatories, including the United States Naval Observatory Flagstaff Station. Each component helps to educate, protect and enforce the imperatives to intelligently reduce detrimental light pollution. One example of a lighting plan assessment can be seen in a report originally commissioned by the Office of the Deputy Prime Minister in the United Kingdom, and now available through the Department for Communities and Local Government. The report details a plan to be implemented throughout the UK, for designing lighting schemes in the countryside, with a particular focus on preserving the environment. In another example, the city of Calgary has recently replaced most residential street lights with models that are comparably energy efficient. The motivation is primarily operation cost and environmental conservation. The costs of installation are expected to be regained through energy savings within six to seven years. The Swiss Agency for Energy Efficiency (SAFE) uses a concept that promises to be of great use in the diagnosis and design of road lighting, "consommation électrique spécifique (CES)", which can be translated into English as "specific electric power consumption (SEC)". Thus, based on observed lighting levels in a wide range of Swiss towns, SAFE has defined target values for electric power consumption per metre for roads of various categories. Thus, SAFE currently recommends an SEC of two to three watts per meter for roads less than ten metres wide (four to six for wider roads). Such a measure provides an easily applicable environmental protection constraint on conventional "norms", which usually are based on the recommendations of lighting manufacturing interests, who may not take into account environmental criteria. In view of ongoing progress in lighting technology, target SEC values will need to be periodically revised downwards. A newer method for predicting and measuring various aspects of light pollution was described in the journal Lighting Research & Technology (September 2008). Scientists at Rensselaer Polytechnic Institute's Lighting Research Center have developed a comprehensive method called Outdoor Site-Lighting Performance (OSP), which allows users to quantify, and thus optimize, the performance of existing and planned lighting designs and applications to minimize excessive or obtrusive light leaving the boundaries of a property. OSP can be used by lighting engineers immediately, particularly for the investigation of glow and trespass (glare analyses are more complex to perform and current commercial software does not readily allow them), and can help users compare several lighting design alternatives for the same site. In the effort to reduce light pollution, researchers have developed a "Unified System of Photometry", which is a way to measure how much or what kind of street lighting is needed. The Unified System of Photometry allows light fixtures to be designed to reduce energy use while maintaining or improving perceptions of visibility, safety, and security. There was a need to create a new system of light measurement at night because the biological way in which the eye's rods and cones process light is different in nighttime conditions versus daytime conditions. Using this new system of photometry, results from recent studies have indicated that replacing traditional, yellowish, high-pressure sodium (HPS) lights with "cool" white light sources, such as induction, fluorescent, ceramic metal halide, or LEDs can actually reduce the amount of electric power used for lighting while maintaining or improving visibility in nighttime conditions. The International Commission on Illumination, also known as the CIE from its French title, la Commission Internationale de l'Eclairage, will soon be releasing its own form of unified photometry for outdoor lighting. Gallery Videos See also Roy Henry Garstang References Further reading Introductory Save the night in Europe. (2021). What is light pollution?. Astronomy Luginbuhl, C. B., Walker, C. E., and Wainscoat R. J. (2009) "Lighting and Astronomy: Light Pollution". Energy ASSIST. (2009). Outdoor Lighting: Visual Efficacy. Crawford, M. (2015). LED light pollution: Can we save energy and save the night? Envirnoment and ecology Albers, S. and Duriscoe, D. (2001) Modeling Light Pollution from Population Data and Implications for National Park Service Lands. TAB. (2019). Light pollution – extent, societal and ecological impacts as well as approaches. General Alliance for Lighting Information. (2017). Alliance for Lighting Information . Dobrzynski, J. H. (2009). Reclaiming the nighy sky. Fraknoi, A. (2018). Light pollution and dark skies: a research guide. Lewicki, M. (2005). Adelaide's Light Pollution - And the Solution. Light Pollution UK. (2006). Is light pollution killing our birds?. Owen, D. (2007). The Dark Side: Making war on light pollution. Handbooks British Astronomical Association. (2009). Blinded by the Light?. A handbook for campaigners against the misuse of artificial light, victims of light pollution and friends of the terrestrial and celestial natural environments. Industrialisation Schivelbusch, W. (1998). Disenchanted Night: The Industrialization of Light in the Nineteenth Century. Reading lists Kyba, C. (2012). Light pollution papers (and books). UK Hillarys. (2021). Skyglow: light pollution & the UK's changing skies. External links Campaigns and research organizations Conferences and events The Urban Wildlands Group (2002) Ecological Consequences of Artificial Night Lighting: Conference ISTIL (2002). The Venice Meeting - Light Pollution Science and Technology Institute NOAO (2009). Dark skies awareness: an IYA2009 cornerstone project. Interactive materials Need-Less—Interactive simulations that demonstrate the effects of light pollution Night Eart. Earth at night. Scientific models Cool, A. D. (2010). German skyglow for population by postcode according to Walker's law. Presentations Technical slide show "Lamp Spectrum and Light Pollution: The Other Side of Light Pollution" Pollution Light sources Lighting Observational astronomy Visibility	[ 0.8107138276100159, 0.44125840067863464, -0.42206206917762756, -0.014101525768637657, -0.07244384288787842, -0.41842201352119446, 0.34548741579055786, 0.4003715217113495, -0.11221366375684738, -0.9068421721458435, -0.3001552224159241, 0.5052958130836487, -0.7018336653709412, 0.468588262796...
18285	https://en.wikipedia.org/wiki/Lagrange%20point	Lagrange point	In celestial mechanics, the Lagrange points (also Lagrangian points, L-points, or libration points) are points of equilibrium for small-mass objects under the influence of two massive orbiting bodies. Mathematically, this involves the solution of the restricted three-body problem in which two bodies are very much more massive than the third. Normally, the two massive bodies exert an unbalanced gravitational force at a point altering the orbit of whatever is at that point. At the Lagrange points, the gravitational forces of the two large bodies and the centrifugal force balance each other. This can make Lagrange points an excellent location for satellites, as few orbit corrections are needed to maintain the desired orbit. Small objects placed in orbit at Lagrange points are in equilibrium in at least two directions relative to the center of mass of the large bodies. There are five such points, labelled L1 to L5, all in the orbital plane of the two large bodies, for each given combination of two orbital bodies. For instance, there are five Lagrangian points L1 to L5 for the Sun–Earth system, and in a similar way there are five different Lagrangian points for the Earth–Moon system. L1, L2, and L3 are on the line through the centres of the two large bodies, while L4 and L5 each act as the third vertex of an equilateral triangle formed with the centres of the two large bodies. L4 and L5 are stable, which implies that objects can orbit around them in a rotating coordinate system tied to the two large bodies. When the mass ratio of the two bodies is large enough, the L4 and L5 points are stable points and have a tendency to pull objects into them. Several planets have trojan asteroids near their L4 and L5 points with respect to the Sun; Jupiter has more than one million of these trojans. Artificial satellites have been placed at L1 and L2 with respect to the Sun and Earth, and with respect to the Earth and the Moon. The Lagrangian points have been proposed for uses in space exploration. History The three collinear Lagrange points (L1, L2, L3) were discovered by Leonhard Euler a few years before Joseph-Louis Lagrange discovered the remaining two. In 1772, Lagrange published an "Essay on the three-body problem". In the first chapter he considered the general three-body problem. From that, in the second chapter, he demonstrated two special constant-pattern solutions, the collinear and the equilateral, for any three masses, with circular orbits. Lagrange points The five Lagrange points are labelled and defined as follows: point The point lies on the line defined between the two large masses M1 and M2. It is the point where the gravitational attraction of M2 and that of M1 combine to produce an equilibrium. An object that orbits the Sun more closely than Earth would normally have a shorter orbital period than Earth, but that ignores the effect of Earth's own gravitational pull. If the object is directly between Earth and the Sun, then Earth's gravity counteracts some of the Sun's pull on the object, and therefore increases the orbital period of the object. The closer to Earth the object is, the greater this effect is. At the point, the orbital period of the object becomes exactly equal to Earth's orbital period. is about 1.5 million kilometers from Earth, or 0.01 au. point The point lies on the line through the two large masses, beyond the smaller of the two. Here, the gravitational forces of the two large masses balance the centrifugal effect on a body at . On the opposite side of Earth from the Sun, the orbital period of an object would normally be greater than that of Earth. The extra pull of Earth's gravity decreases the orbital period of the object, and at the point that orbital period becomes equal to Earth's. Like L1, L2 is about 1.5 million kilometers or 0.01 au from Earth. A notable example of a spacecraft at L2 is the James Webb Space Telescope, designed to operate near the Earth–Sun L2. See other spacecraft at Sun–Earth L2. point The point lies on the line defined by the two large masses, beyond the larger of the two. Within the Sun–Earth system, the point exists on the opposite side of the Sun, a little outside Earth's orbit and slightly closer to the center of the Sun than Earth is. This placement occurs because the Sun is also affected by Earth's gravity and so orbits around the two bodies' barycentre, which is well inside the body of the Sun. An object at Earth's distance from the Sun would have an orbital period of one year if only the Sun's gravity is considered. But an object on the opposite side of the Sun from Earth and directly in line with both "feels" Earth's gravity adding slightly to the Sun's and therefore must orbit a little farther from the barycentre of Earth and Sun in order to have the same 1-year period. It is at the point that the combined pull of Earth and Sun causes the object to orbit with the same period as Earth, in effect orbiting an Earth+Sun mass with the Earth-Sun barycentre at one focus of its orbit. and points The and points lie at the third corners of the two equilateral triangles in the plane of orbit whose common base is the line between the centres of the two masses, such that the point lies ahead of () or behind () the smaller mass with regard to its orbit around the larger mass. Stability The triangular points ( and ) are stable equilibria, provided that the ratio of is greater than 24.96. This is the case for the Sun–Earth system, the Sun–Jupiter system, and, by a smaller margin, the Earth–Moon system. When a body at these points is perturbed, it moves away from the point, but the factor opposite of that which is increased or decreased by the perturbation (either gravity or angular momentum-induced speed) will also increase or decrease, bending the object's path into a stable, kidney bean-shaped orbit around the point (as seen in the corotating frame of reference). The points , , and are positions of unstable equilibrium. Any object orbiting at , , or will tend to fall out of orbit; it is therefore rare to find natural objects there, and spacecraft inhabiting these areas must employ station keeping in order to maintain their position. Natural objects at Lagrange points Due to the natural stability of and , it is common for natural objects to be found orbiting in those Lagrange points of planetary systems. Objects that inhabit those points are generically referred to as 'trojans' or 'trojan asteroids'. The name derives from the names that were given to asteroids discovered orbiting at the Sun–Jupiter and points, which were taken from mythological characters appearing in Homer's Iliad, an epic poem set during the Trojan War. Asteroids at the point, ahead of Jupiter, are named after Greek characters in the Iliad and referred to as the "Greek camp". Those at the point are named after Trojan characters and referred to as the "Trojan camp". Both camps are considered to be types of trojan bodies. As the Sun and Jupiter are the two most massive objects in the Solar System, there are more Sun–Jupiter trojans than for any other pair of bodies. However, smaller numbers of objects are known at the Lagrange points of other orbital systems: The Sun–Earth and points contain interplanetary dust and at least two asteroids, and . The Earth–Moon and points contain concentrations of interplanetary dust, known as Kordylewski clouds. Stability at these specific points is greatly complicated by solar gravitational influence. The Sun–Neptune and points contain several dozen known objects, the Neptune trojans. Mars has four accepted Mars trojans: 5261 Eureka, , , and . Saturn's moon Tethys has two smaller moons of Saturn in its and points, Telesto and Calypso. Another Saturn moon, Dione also has two Lagrangian co-orbitals, Helene at its point and Polydeuces at . The moons wander azimuthally about the Lagrangian points, with Polydeuces describing the largest deviations, moving up to 32° away from the Saturn–Dione point. One version of the giant impact hypothesis postulates that an object named Theia formed at the Sun–Earth or point and crashed into Earth after its orbit destabilized, forming the Moon. In binary stars, the Roche lobe has its apex located at ; if one of the stars expands past its Roche lobe, then it will lose matter to its companion star, known as Roche lobe overflow. Objects which are on horseshoe orbits are sometimes erroneously described as trojans, but do not occupy Lagrange points. Known objects on horseshoe orbits include 3753 Cruithne with Earth, and Saturn's moons Epimetheus and Janus. Physical and mathematical details Lagrangian points are the constant-pattern solutions of the restricted three-body problem. For example, given two massive bodies in orbits around their common barycenter, there are five positions in space where a third body, of comparatively negligible mass, could be placed so as to maintain its position relative to the two massive bodies. As seen in a rotating reference frame that matches the angular velocity of the two co-orbiting bodies, the gravitational fields of two massive bodies combined providing the centripetal force at the Lagrangian points, allowing the smaller third body to be relatively stationary with respect to the first two. The location of L1 is the solution to the following equation, gravitation providing the centripetal force: where r is the distance of the L1 point from the smaller object, R is the distance between the two main objects, and M1 and M2 are the masses of the large and small object, respectively. (The quantity in parentheses on the right is the distance of L1 from the center of mass.) Solving this for r involves solving a quintic function, but if the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1) then and are at approximately equal distances r from the smaller object, equal to the radius of the Hill sphere, given by: We may also write this as: Since the tidal effect of a body is proportional to its mass divided by the distance cubed, this means that the tidal effect of the smaller body at the L or at the L point is about three times of that body. We may also write: where ρ and ρ are the average densities of the two bodies and and are their diameters. The ratio of diameter to distance gives the angle subtended by the body, showing that viewed from these two Lagrange points, the apparent sizes of the two bodies will be similar, especially if the density of the smaller one is about thrice that of the larger, as in the case of the earth and the sun. This distance can be described as being such that the orbital period, corresponding to a circular orbit with this distance as radius around M2 in the absence of M1, is that of M2 around M1, divided by ≈ 1.73: The location of L2 is the solution to the following equation, gravitation providing the centripetal force: with parameters defined as for the L1 case. Again, if the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1) then L2 is at approximately the radius of the Hill sphere, given by: The same remarks about tidal influence and apparent size apply as for the L point. For example, the angular radius of the sun as viewed from L2 is arcsin(/) ≈ 0.264°, whereas that of the earth is arcsin(6371/) ≈ 0.242°. Looking toward the sun from L2 one sees an annular eclipse. It is necessary for a spacecraft, like Gaia, to follow a Lissajous orbit or a halo orbit around L2 in order for its solar panels to get full sun. L3 The location of L3 is the solution to the following equation, gravitation providing the centripetal force: with parameters M1, M2, and R defined as for the L1 and L2 cases, and r now indicates the distance of L3 from the position of the smaller object, if it were rotated 180 degrees about the larger object, while positive r implying L3 is closer to the larger object than the smaller object. If the mass of the smaller object (M2) is much smaller than the mass of the larger object (M1), then: and The reason these points are in balance is that at and the distances to the two masses are equal. Accordingly, the gravitational forces from the two massive bodies are in the same ratio as the masses of the two bodies, and so the resultant force acts through the barycenter of the system; additionally, the geometry of the triangle ensures that the resultant acceleration is to the distance from the barycenter in the same ratio as for the two massive bodies. The barycenter being both the center of mass and center of rotation of the three-body system, this resultant force is exactly that required to keep the smaller body at the Lagrange point in orbital equilibrium with the other two larger bodies of the system (indeed, the third body needs to have negligible mass). The general triangular configuration was discovered by Lagrange working on the three-body problem. Radial acceleration The radial acceleration a of an object in orbit at a point along the line passing through both bodies is given by: where r is the distance from the large body M1, R is the distance between the two main objects, and sgn(x) is the sign function of x. The terms in this function represent respectively: force from M1; force from M2; and centripetal force. The points L3, L1, L2 occur where the acceleration is zero — see chart at right. Positive acceleration is acceleration towards the right of the chart and negative acceleration is towards the left; that is why acceleration has opposite signs on opposite sides of the gravity wells. Stability Although the , , and points are nominally unstable, there are quasi-stable periodic orbits called halo orbits around these points in a three-body system. A full n-body dynamical system such as the Solar System does not contain these periodic orbits, but does contain quasi-periodic (i.e. bounded but not precisely repeating) orbits following Lissajous-curve trajectories. These quasi-periodic Lissajous orbits are what most of Lagrangian-point space missions have used until now. Although they are not perfectly stable, a modest effort of station keeping keeps a spacecraft in a desired Lissajous orbit for a long time. For Sun–Earth- missions, it is preferable for the spacecraft to be in a large-amplitude () Lissajous orbit around than to stay at , because the line between Sun and Earth has increased solar interference on Earth–spacecraft communications. Similarly, a large-amplitude Lissajous orbit around keeps a probe out of Earth's shadow and therefore ensures continuous illumination of its solar panels. The and points are stable provided that the mass of the primary body (e.g. the Earth) is at least 25 times the mass of the secondary body (e.g. the Moon), and the mass of the secondary is at least 10 times that of the tertiary (e.g. the satellite). The Earth is over 81 times the mass of the Moon (the Moon is 1.23% of the mass of the Earth). Although the and points are found at the top of a "hill", as in the effective potential contour plot above, they are nonetheless stable. The reason for the stability is a second-order effect: as a body moves away from the exact Lagrange position, Coriolis acceleration (which depends on the velocity of an orbiting object and cannot be modeled as a contour map) curves the trajectory into a path around (rather than away from) the point. Because the source of stability is the Coriolis force, the resulting orbits can be stable, but generally are not planar, but "three-dimensional": they lie on a warped surface intersecting the ecliptic plane. The kidney-shaped orbits typically shown nested around and are the projections of the orbits on a plane (e.g. the ecliptic) and not the full 3-D orbits. Solar System values This table lists sample values of L1, L2, and L3 within the Solar System. Calculations assume the two bodies orbit in a perfect circle with separation equal to the semimajor axis and no other bodies are nearby. Distances are measured from the larger body's center of mass with L3 showing a negative location. The percentage columns show how the distances compare with the semimajor axis. E.g. for the Moon, L1 is located from Earth's center, which is 84.9% of the Earth–Moon distance or 15.1% in front of the Moon; L2 is located from Earth's center, which is 116.8% of the Earth–Moon distance or 16.8% beyond the Moon; and L3 is located from Earth's center, which is 99.3% of the Earth–Moon distance or 0.7084% in front of the Moon's 'negative' position. Spaceflight applications Sun–Earth Sun–Earth is suited for making observations of the Sun–Earth system. Objects here are never shadowed by Earth or the Moon and, if observing Earth, always view the sunlit hemisphere. The first mission of this type was the 1978 International Sun Earth Explorer 3 (ISEE-3) mission used as an interplanetary early warning storm monitor for solar disturbances. Since June 2015, DSCOVR has orbited the L1 point. Conversely it is also useful for space-based solar telescopes, because it provides an uninterrupted view of the Sun and any space weather (including the solar wind and coronal mass ejections) reaches L1 up to an hour before Earth. Solar and heliospheric missions currently located around L1 include the Solar and Heliospheric Observatory, Wind, and the Advanced Composition Explorer. Planned missions include the Interstellar Mapping and Acceleration Probe (IMAP) and the NEO Surveyor. Sun–Earth is a good spot for space-based observatories. Because an object around will maintain the same relative position with respect to the Sun and Earth, shielding and calibration are much simpler. It is, however, slightly beyond the reach of Earth's umbra, so solar radiation is not completely blocked at L2. Spacecraft generally orbit around L2, avoiding partial eclipses of the Sun to maintain a constant temperature. From locations near L2, the Sun, Earth and Moon are relatively close together in the sky; this means that a large sunshade with the telescope on the dark-side can allow the telescope to cool passively to around 50 K – this is especially helpful for infrared astronomy and observations of the cosmic microwave background. The James Webb Space Telescope was positioned in a halo orbit about L2 on January 24, 2022. Sun–Earth and are saddle points and exponentially unstable with time constant of roughly 23 days. Satellites at these points will wander off in a few months unless course corrections are made. Sun–Earth was a popular place to put a "Counter-Earth" in pulp science fiction and comic books, despite the fact that the existence of a planetary body in this location had been understood as an impossibility once orbital mechanics and the perturbations of planets upon each other's orbits came to be understood, long before the Space Age; the influence of an Earth-sized body on other planets would not have gone undetected, nor would the fact that the foci of Earth's orbital ellipse would not have been in their expected places, due to the mass of the counter-Earth. The Sun–Earth , however, is a weak saddle point and exponentially unstable with time constant of roughly 150 years. Moreover, it could not contain a natural object, large or small, for very long because the gravitational forces of the other planets are stronger than that of Earth (for example, Venus comes within 0.3 AU of this every 20 months). A spacecraft orbiting near Sun–Earth would be able to closely monitor the evolution of active sunspot regions before they rotate into a geoeffective position, so that a seven-day early warning could be issued by the NOAA Space Weather Prediction Center. Moreover, a satellite near Sun–Earth would provide very important observations not only for Earth forecasts, but also for deep space support (Mars predictions and for crewed mission to near-Earth asteroids). In 2010, spacecraft transfer trajectories to Sun–Earth were studied and several designs were considered. Earth–Moon Earth–Moon allows comparatively easy access to Lunar and Earth orbits with minimal change in velocity and this has as an advantage to position a habitable space station intended to help transport cargo and personnel to the Moon and back. Earth–Moon has been used for a communications satellite covering the Moon's far side, for example, Queqiao, launched in 2018, and would be "an ideal location" for a propellant depot as part of the proposed depot-based space transportation architecture. Sun–Venus Scientists at the B612 Foundation were planning to use Venus's L3 point to position their planned Sentinel telescope, which aimed to look back towards Earth's orbit and compile a catalogue of near-Earth asteroids. Sun–Mars In 2017, the idea of positioning a magnetic dipole shield at the Sun–Mars point for use as an artificial magnetosphere for Mars was discussed at a NASA conference. The idea is that this would protect the planet's atmosphere from the Sun's radiation and solar winds. See also Co-orbital configuration Euler's three-body problem Gegenschein Hill sphere Horseshoe orbit Klemperer rosette L5 Society Lagrange point colonization Lagrangian mechanics Lissajous orbit List of objects at Lagrange points Lunar space elevator Oberth effect Explanatory notes References External links Joseph-Louis, Comte Lagrange, from Oeuvres Tome 6, "Essai sur le Problème des Trois Corps"—Essai (PDF); source Tome 6 (Viewer) "Essay on the Three-Body Problem" by J-L Lagrange, translated from the above, in merlyn.demon.co.uk. Considerationes de motu corporum coelestium—Leonhard Euler—transcription and translation at merlyn.demon.co.uk. What are Lagrange points?—European Space Agency page, with good animations Explanation of Lagrange points—Prof. Neil J. Cornish A NASA explanation—also attributed to Neil J. Cornish Explanation of Lagrange points—Prof. John Baez Geometry and calculations of Lagrange points—Dr J R Stockton Locations of Lagrange points, with approximations—Dr. David Peter Stern An online calculator to compute the precise positions of the 5 Lagrange points for any 2-body system—Tony Dunn Astronomy Cast—Ep. 76: "Lagrange Points" by Fraser Cain and Dr. Pamela Gay The Five Points of Lagrange by Neil deGrasse Tyson Earth, a lone Trojan discovered See the Lagrange Points and Halo Orbits subsection under the section on Geosynchronous Transfer Orbit in NASA: Basics of Space Flight, Chapter 5 Trojans (astronomy) Point	[ -0.26997947692871094, 0.2288295328617096, 0.4003109335899353, -0.24003461003303528, 0.13468798995018005, 0.11256969720125198, -0.528423011302948, 0.2997777462005615, 0.0724903866648674, -0.5025939345359802, -0.627479076385498, -0.04357775300741196, -0.28583666682243347, 0.6260587573051453,...
18286	https://en.wikipedia.org/wiki/Lucid%20dream	Lucid dream	A lucid dream is a type of dream where the dreamer becomes aware that they are dreaming. During a lucid dream, the dreamer may gain some amount of control over the dream characters, narrative, or environment; however, this is not actually necessary for a dream to be described as lucid. Lucid dreaming has been studied and reported for many years. Prominent figures from ancient to modern times have been fascinated by lucid dreams and have sought ways to better understand their causes and purpose. Many different theories have emerged as a result of scientific research on the subject and have even been shown in pop culture. Further developments in psychological research have pointed to ways in which this form of dreaming may be utilized as a form of sleep therapy. Etymology The term lucid dream was coined by Dutch author and psychiatrist Frederik van Eeden in his 1913 article A Study of Dreams, though descriptions of dreamers being aware that they are dreaming predate the article. Van Eeden studied his own dreams between January 20, 1898 and December 26, 1912, recording the ones he deemed most important in a dream diary. 352 of these dreams are categorized as lucid. Van Eeden created names for seven different types of dreams he experienced based on the data he collected: initial dreams pathological dreams ordinary dreams vivid dreams demoniacal dreams general dream-sensations lucid dreams He said the seventh type, lucid dreaming, is "the most interesting and worthy of the most careful observation and study." History Ancient Cultivating the dreamer's ability to be aware that they are dreaming is central to both the ancient Indian Hindu practice of Yoga nidra and the Tibetan Buddhist practice of dream Yoga. The cultivation of such awareness was a common practice among early Buddhists. Early references to the phenomenon are also found in ancient Greek writing. For example, the philosopher Aristotle wrote: "often when one is asleep, there is something in consciousness which declares that what then presents itself is but a dream". Meanwhile, the physician Galen of Pergamon used lucid dreams as a form of therapy. In addition, a letter written by Saint Augustine of Hippo in 415 AD tells the story of a dreamer, Doctor Gennadius, and refers to lucid dreaming. 17th century Philosopher and physician Sir Thomas Browne (1605–1682) was fascinated by dreams and described his own ability to lucid dream in his Religio Medici, stating: "...yet in one dream I can compose a whole Comedy, behold the action, apprehend the jests and laugh my self awake at the conceits thereof". Samuel Pepys in his diary entry for 15 August 1665 records a dream, stating: "I had my Lady Castlemayne in my arms and was admitted to use all the dalliance I desired with her, and then dreamt that this could not be awake, but that it was only a dream". 19th century In 1867, the French sinologist Marie-Jean-Léon, Marquis d'Hervey de Saint Denys anonymously published Les Rêves et Les Moyens de Les Diriger; Observations Pratiques ('Dreams and the ways to direct them; practical observations'), in which he describes his own experiences of lucid dreaming, and proposes that it is possible for anyone to learn to dream consciously. 20th century In 1913, Dutch psychiatrist and writer Frederik (Willem) van Eeden (1860–1932) coined the term 'lucid dream' in an article entitled "A Study of Dreams". Some have suggested that the term is a misnomer because Van Eeden was referring to a phenomenon more specific than a lucid dream. Van Eeden intended the term lucid to denote "having insight", as in the phrase a lucid interval applied to someone in temporary remission from a psychosis, rather than as a reference to the perceptual quality of the experience, which may or may not be clear and vivid. Scientific research In 1968, Celia Green analyzed the main characteristics of such dreams, reviewing previously published literature on the subject and incorporating new data from participants of her own. She concluded that lucid dreams were a category of experience quite distinct from ordinary dreams and said they were associated with rapid eye movement sleep (REM sleep). Green was also the first to link lucid dreams to the phenomenon of false awakenings. In 1975, Dr Keith Hearne had the idea to exploit the nature of Rapid Eye Movements (REM) to allow a dreamer to send a message directly from dreams to the waking world. Working with an experienced lucid dreamer (Alan Worsley), he eventually succeeded in recording (via the use of an electrooculogram or EOG) a pre-defined set of eye movements signalled from within Worsley's lucid dream. This occurred at around 8 am on the morning of April 12, 1975. Hearne's EOG experiment was formally recognized through publication in the journal for The Society for Psychical Research. Lucid dreaming was subsequently researched by asking dreamers to perform pre-determined physical responses while experiencing a dream, including eye movement signals. In 1980, Stephen LaBerge at Stanford University developed such techniques as part of his doctoral dissertation. In 1985, LaBerge performed a pilot study that showed that time perception while counting during a lucid dream is about the same as during waking life. Lucid dreamers counted out ten seconds while dreaming, signaling the start and the end of the count with a pre-arranged eye signal measured with electrooculogram recording. LaBerge's results were confirmed by German researchers D. Erlacher and M. Schredl in 2004. In a further study by Stephen LaBerge, four subjects were compared either singing while dreaming or counting while dreaming. LaBerge found that the right hemisphere was more active during singing and the left hemisphere was more active during counting. Neuroscientist J. Allan Hobson has hypothesized what might be occurring in the brain while lucid. The first step to lucid dreaming is recognizing one is dreaming. This recognition might occur in the dorsolateral prefrontal cortex, which is one of the few areas deactivated during REM sleep and where working memory occurs. Once this area is activated and the recognition of dreaming occurs, the dreamer must be cautious to let the dream continue but be conscious enough to remember that it is a dream. While maintaining this balance, the amygdala and parahippocampal cortex might be less intensely activated. To continue the intensity of the dream hallucinations, it is expected the pons and the parieto-occipital junction stay active. Using electroencephalography (EEG) and other polysomnographical measurements, LaBerge and others have shown that lucid dreams begin in the Rapid Eye Movement (REM) stage of sleep. LaBerge also proposes that there are higher amounts of beta-1 frequency band (13–19 Hz) brain wave activity experienced by lucid dreamers, hence there is an increased amount of activity in the parietal lobes making lucid dreaming a conscious process. Paul Tholey, a German Gestalt psychologist and a professor of psychology and sports science, originally studied dreams in order to resolve the question of whether one dreams in colour or black and white. In his phenomenological research, he outlined an epistemological frame using critical realism. Tholey instructed his subjects to continuously suspect waking life to be a dream, in order that such a habit would manifest itself during dreams. He called this technique for inducing lucid dreams the Reflexionstechnik (reflection technique). Subjects learned to have such lucid dreams; they observed their dream content and reported it soon after awakening. Tholey could examine the cognitive abilities of dream figures. Nine trained lucid dreamers were directed to set other dream figures arithmetic and verbal tasks during lucid dreaming. Dream figures who agreed to perform the tasks proved more successful in verbal than in arithmetic tasks. Tholey discussed his scientific results with Stephen LaBerge, who has a similar approach. A study was conducted by Stephen LaBerge and other scientists to see if it were possible to attain the ability to lucid dream through a drug. In 2018, galantamine was given to 121 patients in a double-blind, placebo-controlled trial, the only one of its kind. Some participants found as much as a 42 percent increase in their ability to lucid dream, compared to self-reports from the past six months, and ten people experienced a lucid dream for the first time. It is theorized that galantamine allows acetylcholine to build up, leading to greater recollection and awareness during dreaming. Two-way communication Teams of cognitive scientists established real-time two-way communication with people undergoing a lucid dream. During dreaming they were able to consciously communicate with experimenters via eye movements or facial muscle signals, were able to comprehend complex questions and use working memory. Such interactive lucid dreaming could be a new approach for the scientific exploration of the dream state and could have applications for learning and creativity. Alternative theories Other researchers suggest that lucid dreaming is not a state of sleep, but of brief wakefulness, or "micro-awakening". Experiments by Stephen LaBerge used "perception of the outside world" as a criterion for wakefulness while studying lucid dreamers, and their sleep state was corroborated with physiological measurements. LaBerge's subjects experienced their lucid dream while in a state of REM, which critics felt may mean that the subjects are fully awake. J Allen Hobson responded that lucid dreaming must be a state of both waking and dreaming. Philosopher Norman Malcolm has argued against the possibility of checking the accuracy of dream reports, pointing out that "the only criterion of the truth of a statement that someone has had a certain dream is, essentially, his saying so." Definition Paul Tholey laid the epistemological basis for the research of lucid dreams, proposing seven different conditions of clarity that a dream must fulfill in order to be defined as a lucid dream: Awareness of the dream state (orientation) Awareness of the capacity to make decisions Awareness of memory functions Awareness of self Awareness of the dream environment Awareness of the meaning of the dream Awareness of concentration and focus (the subjective clarity of that state) Later, in 1992, a study by Deirdre Barrett examined whether lucid dreams contained four "corollaries" of lucidity: The dreamer is aware that they are dreaming Objects disappear after waking Physical laws need not apply in the dream The dreamer has a clear memory of the waking world Barrett found less than a quarter of lucidity accounts exhibited all four. Subsequently, Stephen LaBerge studied the prevalence of being able to control the dream scenario among lucid dreams, and found that while dream control and dream awareness are correlated, neither requires the other. LaBerge found dreams that exhibit one clearly without the capacity for the other; also, in some dreams where the dreamer is lucid and aware they could exercise control, they choose simply to observe. Prevalence and frequency In 2016, a meta-analytic study by David Saunders and colleagues on 34 lucid dreaming studies, taken from a period of 50 years, demonstrated that 55% of a pooled sample of 24,282 people claimed to have experienced lucid dreams at least once or more in their lifetime. Furthermore, for those that stated they did experience lucid dreams, approximately 23% reported to experience them on a regular basis, as often as once a month or more. In a 2004 study on lucid dream frequency and personality, a moderate correlation between nightmare frequency and frequency of lucid dreaming was demonstrated. Some lucid dreamers also reported that nightmares are a trigger for dream lucidity. Previous studies have reported that lucid dreaming is more common among adolescents than adults. A 2015 study by Julian Mutz and Amir-Homayoun Javadi showed that people who had practiced meditation for a long time tended to have more lucid dreams. The authors claimed that "Lucid dreaming is a hybrid state of consciousness with features of both waking and dreaming" in a review they published in Neuroscience of Consciousness in 2017. Mutz and Javadi found that during lucid dreaming, there is an increase in activity of the dorsolateral prefrontal cortex, the bilateral frontopolar prefrontal cortex, the precuneus, the inferior parietal lobules, and the supramarginal gyrus. All are brain functions related to higher cognitive functions including working memory, planning, and self-consciousness. The researchers also found that during a lucid dream, "levels of self-determination" were similar to those that people experienced during states of wakefulness. They also found that lucid dreamers can only control limited aspects of their dream at once. Mutz and Javadi also have stated that by studying lucid dreaming further, scientists could learn more about various types of consciousness, which happen to be less easy to separate and research at other times. Suggested applications Treating nightmares It has been suggested that those who suffer from nightmares could benefit from the ability to be aware they are indeed dreaming. A pilot study performed in 2006 showed that lucid dreaming therapy treatment was successful in reducing nightmare frequency. This treatment consisted of exposure to the idea, mastery of the technique, and lucidity exercises. It was not clear what aspects of the treatment were responsible for the success of overcoming nightmares, though the treatment as a whole was said to be successful. Australian psychologist Milan Colic has explored the application of principles from narrative therapy to clients' lucid dreams, to reduce the impact not only of nightmares during sleep but also depression, self-mutilation, and other problems in waking life. Colic found that therapeutic conversations could reduce the distressing content of dreams, while understandings about life—and even characters—from lucid dreams could be applied to their lives with marked therapeutic benefits. Psychotherapists have applied lucid dreaming as a part of therapy. Studies have shown that, by inducing a lucid dream, recurrent nightmares can be alleviated. It is unclear whether this alleviation is due to lucidity or the ability to alter the dream itself. A 2006 study performed by Victor Spoormaker and Van den Bout evaluated the validity of lucid dreaming treatment (LDT) in chronic nightmare sufferers. LDT is composed of exposure, mastery and lucidity exercises. Results of lucid dreaming treatment revealed that the nightmare frequency of the treatment groups had decreased. In another study, Spoormaker, Van den Bout, and Meijer (2003) investigated lucid dreaming treatment for nightmares by testing eight subjects who received a one-hour individual session, which consisted of lucid dreaming exercises. The results of the study revealed that the nightmare frequency had decreased and the sleep quality had slightly increased. Holzinger, Klösch, and Saletu managed a psychotherapy study under the working name of ‘Cognition during dreaming—a therapeutic intervention in nightmares’, which included 40 subjects, men and women, 18–50 years old, whose life quality was significantly altered by nightmares. The test subjects were administered Gestalt group therapy and 24 of them were also taught to enter the state of lucid dreaming by Holzinger. This was purposefully taught in order to change the course of their nightmares. The subjects then reported the diminishment of their nightmare prevalence from 2–3 times a week to 2–3 times per month. Creativity In her book The Committee of Sleep, Deirdre Barrett describes how some experienced lucid dreamers have learned to remember specific practical goals such as artists looking for inspiration seeking a show of their own work once they become lucid or computer programmers looking for a screen with their desired code. However, most of these dreamers had many experiences of failing to recall waking objectives before gaining this level of control. Exploring the World of Lucid Dreaming by Stephen LaBerge and Howard Rheingold (1990) discusses creativity within dreams and lucid dreams, including testimonials from a number of people who claim they have used the practice of lucid dreaming to help them solve a number of creative issues, from an aspiring parent thinking of potential baby names to a surgeon practicing surgical techniques. The authors discuss how creativity in dreams could stem from "conscious access to the contents of our unconscious minds"; access to "tacit knowledge"—the things we know but can't explain, or things we know but are unaware that we know. The Dreams Behind the Music book by Craig Webb (2016) details lucid dreams of a number of musical artists, including how they are able not just to hear, but also compose, mix, arrange, practice, and perform music while conscious within their dreams. In popular culture Films Films like Dreamscape (1984), Waking Life (2001), Vanilla Sky (2001), Paprika (2006), Inception (2010), Lucid Dream (2017) and 118 (2019) refer to lucid dreaming. Songs The spoken bridge in the 1991 song Silent Lucidity by Queensrÿche instructs the listener on how to achieve lucid dreaming. 1999 hit song "Higher" by American rock band Creed was directly inspired by lead singer Scott Stapp's lucid dreaming experience. In the hit 2018 song by Juice Wrld, "Lucid Dreams," Juice uses the analogy of a lucid dream he can't control to describe the memory of his ex-romantic interest he can't forget. Other Media In the episode Waking Moments in Star Trek: Voyager (1998), Commander Chakotay uses lucid dreaming to free Voyager from alien control. The video game Superliminal (2019) takes place within "dream therapy" where the player character is in a lucid dream induced by the Pierce Institute. Risks Though lucid dreaming can be beneficial to a number of aspects of life, some risks have been suggested. Those who have never had a lucid dream may not understand what is happening when they experience it for the first time. This could cause those individuals to feel a variety of different emotions as they are going through a completely new psychological experience. Feelings of stress, worry, or confusion could arise. On the other hand, the feeling of empowerment could also come up as they realize that they are now in control of their dreams. Individuals who experience lucid dreams regularly could begin to feel isolated from others due to the fact that they have different experiences when it comes to dreaming. Someone struggling with certain mental illnesses could find it hard to be able to tell the difference between reality and the actual dream. A very small percentage of people may experience sleep paralysis, which is something that can sometimes be confused with lucid dreaming. Although from the outside, both of these seem to be quite similar, there are a few distinct differences that can help differentiate them. A person usually experiences sleep paralysis when they partially wake up in REM atonia, a state in which said person is partially paralyzed and cannot move their limbs. When in sleep paralysis, people may also experience hallucinations. Although said hallucinations cannot cause physical damage, they may still be frightening. There are three common types of hallucinations: an intruder in the same room, a crushing feeling on one's chest or back, and a feeling of flying or levitating. About 7.6% of the general population have experienced sleep paralysis at least once. Exiting sleep paralysis to a waking state can be achieved by intently focusing on a part of the body, such as a finger, and wiggling it, continuing the action of moving to then the hand, the arm, and so on, until the person is fully awake. Long-term risks with lucid dreaming have not been extensively studied. Although many people have been lucid dreaming for many years without any adverse effects. See also Active imagination Astral projection Oneirology Pre-lucid dream Recurring dream Sleep paralysis Yoga nidra References Further reading Blanken, C.M. den and Meijer, E.J.G. "An Historical View of Dreams and the Ways to Direct Them; Practical Observations by Marie-Jean-Léon-Lecoq, le Marquis d'Hervey-Saint-Denys". Lucidity Letter, 7 (2) 67–78; 1988. Revised Edition in: Lucidity,10 (1&2) 311–22; 1991. Tholey, Paul (1983). "Relation between dream content and eye movements tested by lucid dreams". Perceptual and Motor Skills, 56, pp. 875–78. Tholey, Paul (1988). "A model for lucidity training as a means of self-healing and psychological growth". In: J. Gackenbach & S. LaBerge (Eds.), Conscious mind, sleeping brain. Perspectives on lucid dreaming, pp. 263–87. London: Plenum Press. Lucid dreaming can be induced by electric scalp stimulation, study finds A look at four psychology fads – a comparison of est, primal therapy, Transcendental Meditation and lucid dreaming at the Los Angeles Times Dream Sleep physiology Phenomena	[ 0.20296606421470642, -0.025537433102726936, -0.03449953347444534, 0.14474567770957947, -0.1429188847541809, -0.03555385768413544, 0.8712608218193054, 0.5499125719070435, -0.3931765854358673, -0.7043707370758057, -0.541145384311676, 0.33482128381729126, -0.10677920281887054, 0.6381306052207...
18288	https://en.wikipedia.org/wiki/Lyric	Lyric	Lyric may refer to: Lyrics, the words, often in verse form, which are sung, usually to a melody, and constitute the semantic content of a song Lyric poetry is a form of poetry that expresses a subjective, personal point of view Lyric, from the Greek language, a song that is played with a lyre Lyric describes, in the classification of the human voice in European classical music, a specific vocal weight and a range at the upper end of the given voice part RTÉ lyric fm, a radio station in Ireland Lyric (group), a rhythm and blues girl group "Lyric" (song), a single released in June 2003 by Zwan Lyric Hearing, an extended wear hearing aid The Lyric (magazine), a North American poetry magazine The Lyric (album), a 2005 jazz album by Jim Tomlinson and Stacey Kent See also Lyric Opera (disambiguation) Lyric Theatre (disambiguation)	[ 0.049177609384059906, -0.07300245016813278, -0.3749779164791107, -0.14790818095207214, -0.3367425799369812, 0.16171538829803467, 0.5173007249832153, 0.005858538206666708, 0.11763586103916168, -0.776042640209198, -0.7654566168785095, 0.6712885499000549, 0.15850713849067688, -0.2156315743923...
18290	https://en.wikipedia.org/wiki/Light-emitting%20diode	Light-emitting diode	A light-emitting diode (LED) is a semiconductor light source that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresponding to the energy of the photons) is determined by the energy required for electrons to cross the band gap of the semiconductor. White light is obtained by using multiple semiconductors or a layer of light-emitting phosphor on the semiconductor device. Appearing as practical electronic components in 1962, the earliest LEDs emitted low-intensity infrared (IR) light. Infrared LEDs are used in remote-control circuits, such as those used with a wide variety of consumer electronics. The first visible-light LEDs were of low intensity and limited to red. Early LEDs were often used as indicator lamps, replacing small incandescent bulbs, and in seven-segment displays. Recent developments have produced LEDs available in visible, ultraviolet (UV), and infrared wavelengths, with high, low, or intermediate light output, for instance white LEDs suitable for room and outdoor area lighting. LEDs have also given rise to new types of displays and sensors, while their high switching rates are useful in advanced communications technology with applications as diverse as aviation lighting, fairy lights, automotive headlamps, advertising, general lighting, traffic signals, camera flashes, lighted wallpaper, horticultural grow lights, and medical devices. LEDs have many advantages over incandescent light sources, including lower power consumption, longer lifetime, improved physical robustness, smaller size, and faster switching. In exchange for these generally favorable attributes, disadvantages of LEDs include electrical limitations to low voltage and generally to DC (not AC) power, inability to provide steady illumination from a pulsing DC or an AC electrical supply source, and lesser maximum operating temperature and storage temperature. In contrast to LEDs, incandescent lamps can be made to intrinsically run at virtually any supply voltage, can utilize either AC or DC current interchangeably, and will provide steady illumination when powered by AC or pulsing DC even at a frequency as low as 50 Hz. LEDs usually need electronic support components to function, while an incandescent bulb can and usually does operate directly from an unregulated DC or AC power source. History Discoveries and early devices Electroluminescence as a phenomenon was discovered in 1907 by the English experimenter H. J. Round of Marconi Labs, using a crystal of silicon carbide and a cat's-whisker detector. Russian inventor Oleg Losev reported creation of the first LED in 1927. His research was distributed in Soviet, German and British scientific journals, but no practical use was made of the discovery for several decades. In 1936, Georges Destriau observed that electroluminescence could be produced when zinc sulphide (ZnS) powder is suspended in an insulator and an alternating electrical field is applied to it. In his publications, Destriau often referred to luminescence as Losev-Light. Destriau worked in the laboratories of Madame Marie Curie, also an early pioneer in the field of luminescence with research on radium. Hungarian Zoltán Bay together with György Szigeti pre-empted LED lighting in Hungary in 1939 by patenting a lighting device based on SiC, with an option on boron carbide, that emitted white, yellowish white, or greenish white depending on impurities present. Kurt Lehovec, Carl Accardo, and Edward Jamgochian explained these first LEDs in 1951 using an apparatus employing SiC crystals with a current source of a battery or a pulse generator and with a comparison to a variant, pure, crystal in 1953. Rubin Braunstein of the Radio Corporation of America reported on infrared emission from gallium arsenide (GaAs) and other semiconductor alloys in 1955. Braunstein observed infrared emission generated by simple diode structures using gallium antimonide (GaSb), GaAs, indium phosphide (InP), and silicon-germanium (SiGe) alloys at room temperature and at 77 kelvins. In 1957, Braunstein further demonstrated that the rudimentary devices could be used for non-radio communication across a short distance. As noted by Kroemer Braunstein "…had set up a simple optical communications link: Music emerging from a record player was used via suitable electronics to modulate the forward current of a GaAs diode. The emitted light was detected by a PbS diode some distance away. This signal was fed into an audio amplifier and played back by a loudspeaker. Intercepting the beam stopped the music. We had a great deal of fun playing with this setup." This setup presaged the use of LEDs for optical communication applications. In September 1961, while working at Texas Instruments in Dallas, Texas, James R. Biard and Gary Pittman discovered near-infrared (900 nm) light emission from a tunnel diode they had constructed on a GaAs substrate. By October 1961, they had demonstrated efficient light emission and signal coupling between a GaAs p-n junction light emitter and an electrically isolated semiconductor photodetector. On August 8, 1962, Biard and Pittman filed a patent titled "Semiconductor Radiant Diode" based on their findings, which described a zinc-diffused p–n junction LED with a spaced cathode contact to allow for efficient emission of infrared light under forward bias. After establishing the priority of their work based on engineering notebooks predating submissions from G.E. Labs, RCA Research Labs, IBM Research Labs, Bell Labs, and Lincoln Lab at MIT, the U.S. patent office issued the two inventors the patent for the GaAs infrared light-emitting diode (U.S. Patent US3293513), the first practical LED. Immediately after filing the patent, Texas Instruments (TI) began a project to manufacture infrared diodes. In October 1962, TI announced the first commercial LED product (the SNX-100), which employed a pure GaAs crystal to emit an 890 nm light output. In October 1963, TI announced the first commercial hemispherical LED, the SNX-110. The first visible-spectrum (red) LED was demonstrated by J. W. Allen and R. J. Cherry in late 1961 at the SERL in Baldock, UK. This work was reported in Journal of Physics and Chemistry of Solids, Volume 23, Issue 5, May 1962, Pages 509–511. Another early device was demonstrated by Nick Holonyak, Jr. on October 9, 1962, while he was working for General Electric in Syracuse, New York. Holonyak and Bevacqua reported this LED in the journal Applied Physics Letters on December 1, 1962. M. George Craford, a former graduate student of Holonyak, invented the first yellow LED and improved the brightness of red and red-orange LEDs by a factor of ten in 1972. In 1976, T. P. Pearsall designed the first high-brightness, high-efficiency LEDs for optical fiber telecommunications by inventing new semiconductor materials specifically adapted to optical fiber transmission wavelengths. Initial commercial development The first commercial visible-wavelength LEDs were commonly used as replacements for incandescent and neon indicator lamps, and in seven-segment displays, first in expensive equipment such as laboratory and electronics test equipment, then later in such appliances as calculators, TVs, radios, telephones, as well as watches (see list of signal uses). Until 1968, visible and infrared LEDs were extremely costly, in the order of US$200 per unit, and so had little practical use. Hewlett-Packard (HP) was engaged in research and development (R&D) on practical LEDs between 1962 and 1968, by a research team under Howard C. Borden, Gerald P. Pighini and Mohamed M. Atalla at HP Associates and HP Labs. During this time, Atalla launched a material science investigation program on gallium arsenide (GaAs), gallium arsenide phosphide (GaAsP) and indium arsenide (InAs) devices at HP, and they collaborated with Monsanto Company on developing the first usable LED products. The first usable LED products were HP's LED display and Monsanto's LED indicator lamp, both launched in 1968. Monsanto was the first organization to mass-produce visible LEDs, using GaAsP in 1968 to produce red LEDs suitable for indicators. Monsanto had previously offered to supply HP with GaAsP, but HP decided to grow its own GaAsP. In February 1969, Hewlett-Packard introduced the HP Model 5082-7000 Numeric Indicator, the first LED device to use integrated circuit (integrated LED circuit) technology. It was the first intelligent LED display, and was a revolution in digital display technology, replacing the Nixie tube and becoming the basis for later LED displays. Atalla left HP and joined Fairchild Semiconductor in 1969. He was the vice president and general manager of the Microwave & Optoelectronics division, from its inception in May 1969 up until November 1971. He continued his work on LEDs, proposing they could be used for indicator lights and optical readers in 1971. In the 1970s, commercially successful LED devices at less than five cents each were produced by Fairchild Optoelectronics. These devices employed compound semiconductor chips fabricated with the planar process (developed by Jean Hoerni, based on Atalla's surface passivation method). The combination of planar processing for chip fabrication and innovative packaging methods enabled the team at Fairchild led by optoelectronics pioneer Thomas Brandt to achieve the needed cost reductions. LED producers continue to use these methods. The early red LEDs were bright enough only for use as indicators, as the light output was not enough to illuminate an area. Readouts in calculators were so small that plastic lenses were built over each digit to make them legible. Later, other colors became widely available and appeared in appliances and equipment. Early LEDs were packaged in metal cases similar to those of transistors, with a glass window or lens to let the light out. Modern indicator LEDs are packed in transparent molded plastic cases, tubular or rectangular in shape, and often tinted to match the device color. Infrared devices may be dyed, to block visible light. More complex packages have been adapted for efficient heat dissipation in high-power LEDs. Surface-mounted LEDs further reduce the package size. LEDs intended for use with fiber optics cables may be provided with an optical connector. Blue LED The first blue-violet LED using magnesium-doped gallium nitride was made at Stanford University in 1972 by Herb Maruska and Wally Rhines, doctoral students in materials science and engineering. At the time Maruska was on leave from RCA Laboratories, where he collaborated with Jacques Pankove on related work. In 1971, the year after Maruska left for Stanford, his RCA colleagues Pankove and Ed Miller demonstrated the first blue electroluminescence from zinc-doped gallium nitride, though the subsequent device Pankove and Miller built, the first actual gallium nitride light-emitting diode, emitted green light. In 1974 the U.S. Patent Office awarded Maruska, Rhines and Stanford professor David Stevenson a patent for their work in 1972 (U.S. Patent US3819974 A). Today, magnesium-doping of gallium nitride remains the basis for all commercial blue LEDs and laser diodes. In the early 1970s, these devices were too dim for practical use, and research into gallium nitride devices slowed. In August 1989, Cree introduced the first commercially available blue LED based on the indirect bandgap semiconductor, silicon carbide (SiC). SiC LEDs had very low efficiency, no more than about 0.03%, but did emit in the blue portion of the visible light spectrum. In the late 1980s, key breakthroughs in GaN epitaxial growth and p-type doping ushered in the modern era of GaN-based optoelectronic devices. Building upon this foundation, Theodore Moustakas at Boston University patented a method for producing high-brightness blue LEDs using a new two-step process in 1991. Two years later, in 1993, high-brightness blue LEDs were demonstrated by Shuji Nakamura of Nichia Corporation using a gallium nitride growth process. In parallel, Isamu Akasaki and Hiroshi Amano of Nagoya University were working on developing the important GaN deposition on sapphire substrates and the demonstration of p-type doping of GaN. This new development revolutionized LED lighting, making high-power blue light sources practical, leading to the development of technologies like Blu-ray. Nakamura was awarded the 2006 Millennium Technology Prize for his invention. Nakamura, Hiroshi Amano and Isamu Akasaki were awarded the Nobel Prize in Physics in 2014 for the invention of the blue LED. In 2015, a US court ruled that three companies had infringed Moustakas's prior patent, and ordered them to pay licensing fees of not less than US$13 million. In 1995, Alberto Barbieri at the Cardiff University Laboratory (GB) investigated the efficiency and reliability of high-brightness LEDs and demonstrated a "transparent contact" LED using indium tin oxide (ITO) on (AlGaInP/GaAs). In 2001 and 2002, processes for growing gallium nitride (GaN) LEDs on silicon were successfully demonstrated. In January 2012, Osram demonstrated high-power InGaN LEDs grown on silicon substrates commercially, and GaN-on-silicon LEDs are in production at Plessey Semiconductors. As of 2017, some manufacturers are using SiC as the substrate for LED production, but sapphire is more common, as it has the most similar properties to that of gallium nitride, reducing the need for patterning the sapphire wafer (patterned wafers are known as epi wafers). Samsung, the University of Cambridge, and Toshiba are performing research into GaN on Si LEDs. Toshiba has stopped research, possibly due to low yields. Some opt towards epitaxy, which is difficult on silicon, while others, like the University of Cambridge, opt towards a multi-layer structure, in order to reduce (crystal) lattice mismatch and different thermal expansion ratios, in order to avoid cracking of the LED chip at high temperatures (e.g. during manufacturing), reduce heat generation and increase luminous efficiency. Sapphire substrate patterning can be carried out with nanoimprint lithography. GaN-on-Si is desirable since it takes advantage of existing semiconductor manufacturing infrastructure; however, it is difficult to achieve. It also allows for the wafer-level packaging of LED dies resulting in extremely small LED packages. GaN is often deposited using Metalorganic vapour-phase epitaxy (MOCVD), and it also utilizes Lift-off. White LEDs and the illumination breakthrough Even though white light can be created using individual red, green and blue LEDs, this results in poor color rendering, since only three narrow bands of wavelengths of light are being emitted. The attainment of high efficiency blue LEDs was quickly followed by the development of the first white LED. In this device a :Ce (known as "YAG" or Ce:YAG phosphor) cerium-doped phosphor coating produces yellow light through fluorescence. The combination of that yellow with remaining blue light appears white to the eye. Using different phosphors produces green and red light through fluorescence. The resulting mixture of red, green and blue is perceived as white light, with improved color rendering compared to wavelengths from the blue LED/YAG phosphor combination. The first white LEDs were expensive and inefficient. However, the light output of LEDs has increased exponentially. The latest research and development has been propagated by Japanese manufacturers such as Panasonic, and Nichia, and by Korean and Chinese manufacturers such as Samsung, Solstice, Kingsun, Hoyol and others. This trend in increased output has been called Haitz's law after Roland Haitz. Light output and efficiency of blue and near-ultraviolet LEDs rose and the cost of reliable devices fell. This led to relatively high-power white-light LEDs for illumination, which are replacing incandescent and fluorescent lighting. Experimental white LEDs were demonstrated in 2014 to produce 303 lumens per watt of electricity (lm/W); some can last up to 100,000 hours. However, commercially available LEDs have an efficiency of up to 223 lm/W as of 2018. A previous record of 135 lm/W was achieved by Nichia in 2010. Compared to incandescent bulbs, this is a huge increase in electrical efficiency, and even though LEDs are more expensive to purchase, overall lifetime cost is significantly cheaper than that of incandescent bulbs. The LED chip is encapsulated inside a small, plastic, white mold. It can be encapsulated using resin (polyurethane-based), silicone, or epoxy containing (powdered) Cerium-doped YAG phosphor. After allowing the solvents to evaporate, the LEDs are often tested, and placed on tapes for SMT placement equipment for use in LED light bulb production. Encapsulation is performed after probing, dicing, die transfer from wafer to package, and wire bonding or flip chip mounting, perhaps using Indium tin oxide, a transparent electrical conductor. In this case, the bond wire(s) are attached to the ITO film that has been deposited in the LEDs. Some "remote phosphor" LED light bulbs use a single plastic cover with YAG phosphor for several blue LEDs, instead of using phosphor coatings on single-chip white LEDs. The temperature of the phosphor during operation and how it is applied limits the size of an LED die. Wafer-level packaged white LEDs allow for extremely small LEDs. Physics of light production and emission In a light emitting diode, the recombination of electrons and electron holes in a semiconductor produces light (be it infrared, visible or UV), a process called "electroluminescence". The wavelength of the light depends on the energy band gap of the semiconductors used. Since these materials have a high index of refraction, design features of the devices such as special optical coatings and die shape are required to efficiently emit light. Unlike a laser, the light emitted from an LED is neither spectrally coherent nor even highly monochromatic. However, its spectrum is sufficiently narrow that it appears to the human eye as a pure (saturated) color. Also unlike most lasers, its radiation is not spatially coherent, so it cannot approach the very high brightnesses characteristic of lasers. Colors By selection of different semiconductor materials, single-color LEDs can be made that emit light in a narrow band of wavelengths from near-infrared through the visible spectrum and into the ultraviolet range. As the wavelengths become shorter, because of the larger band gap of these semiconductors, the operating voltage of the LED increases. Blue and ultraviolet Blue LEDs have an active region consisting of one or more InGaN quantum wells sandwiched between thicker layers of GaN, called cladding layers. By varying the relative In/Ga fraction in the InGaN quantum wells, the light emission can in theory be varied from violet to amber. Aluminium gallium nitride (AlGaN) of varying Al/Ga fraction can be used to manufacture the cladding and quantum well layers for ultraviolet LEDs, but these devices have not yet reached the level of efficiency and technological maturity of InGaN/GaN blue/green devices. If un-alloyed GaN is used in this case to form the active quantum well layers, the device emits near-ultraviolet light with a peak wavelength centred around 365 nm. Green LEDs manufactured from the InGaN/GaN system are far more efficient and brighter than green LEDs produced with non-nitride material systems, but practical devices still exhibit efficiency too low for high-brightness applications. With AlGaN and AlGaInN, even shorter wavelengths are achievable. Near-UV emitters at wavelengths around 360–395 nm are already cheap and often encountered, for example, as black light lamp replacements for inspection of anti-counterfeiting UV watermarks in documents and bank notes, and for UV curing. Substantially more expensive, shorter-wavelength diodes are commercially available for wavelengths down to 240 nm. As the photosensitivity of microorganisms approximately matches the absorption spectrum of DNA, with a peak at about 260 nm, UV LED emitting at 250–270 nm are expected in prospective disinfection and sterilization devices. Recent research has shown that commercially available UVA LEDs (365 nm) are already effective disinfection and sterilization devices. UV-C wavelengths were obtained in laboratories using aluminium nitride (210 nm), boron nitride (215 nm) and diamond (235 nm). White There are two primary ways of producing white light-emitting diodes. One is to use individual LEDs that emit three primary colors—red, green and blue—and then mix all the colors to form white light. The other is to use a phosphor material to convert monochromatic light from a blue or UV LED to broad-spectrum white light, similar to a fluorescent lamp. The yellow phosphor is cerium-doped YAG crystals suspended in the package or coated on the LED. This YAG phosphor causes white LEDs to appear yellow when off, and the space between the crystals allow some blue light to pass through in LEDs with partial phosphor conversion. Alternatively, white LEDs may use other phosphors like manganese(IV)-doped potassium fluorosilicate (PFS) or other engineered phosphors. PFS assists in red light generation, and is used in conjunction with conventional Ce:YAG phosphor. In LEDs with PFS phosphor, some blue light passes through the phosphors, the Ce:YAG phosphor converts blue light to green and red (yellow) light, and the PFS phosphor converts blue light to red light. The color, emission spectrum or color temperature of white phosphor converted and other phosphor converted LEDs can be controlled by changing the concentration of several phosphors that form a phosphor blend used in an LED package. The 'whiteness' of the light produced is engineered to suit the human eye. Because of metamerism, it is possible to have quite different spectra that appear white. The appearance of objects illuminated by that light may vary as the spectrum varies. This is the issue of color rendition, quite separate from color temperature. An orange or cyan object could appear with the wrong color and much darker as the LED or phosphor does not emit the wavelength it reflects. The best color rendition LEDs use a mix of phosphors, resulting in less efficiency and better color rendering. RGB systems Mixing red, green, and blue sources to produce white light needs electronic circuits to control the blending of the colors. Since LEDs have slightly different emission patterns, the color balance may change depending on the angle of view, even if the RGB sources are in a single package, so RGB diodes are seldom used to produce white lighting. Nonetheless, this method has many applications because of the flexibility of mixing different colors, and in principle, this mechanism also has higher quantum efficiency in producing white light. There are several types of multicolor white LEDs: di-, tri-, and tetrachromatic white LEDs. Several key factors that play among these different methods include color stability, color rendering capability, and luminous efficacy. Often, higher efficiency means lower color rendering, presenting a trade-off between the luminous efficacy and color rendering. For example, the dichromatic white LEDs have the best luminous efficacy (120 lm/W), but the lowest color rendering capability. Although tetrachromatic white LEDs have excellent color rendering capability, they often have poor luminous efficacy. Trichromatic white LEDs are in between, having both good luminous efficacy (>70 lm/W) and fair color rendering capability. One of the challenges is the development of more efficient green LEDs. The theoretical maximum for green LEDs is 683 lumens per watt but as of 2010 few green LEDs exceed even 100 lumens per watt. The blue and red LEDs approach their theoretical limits. Multicolor LEDs also offer a new means to form light of different colors. Most perceivable colors can be formed by mixing different amounts of three primary colors. This allows precise dynamic color control. However, this type of LED's emission power decays exponentially with rising temperature, resulting in a substantial change in color stability. Such problems inhibit industrial use. Multicolor LEDs without phosphors cannot provide good color rendering because each LED is a narrowband source. LEDs without phosphor, while a poorer solution for general lighting, are the best solution for displays, either backlight of LCD, or direct LED based pixels. Dimming a multicolor LED source to match the characteristics of incandescent lamps is difficult because manufacturing variations, age, and temperature change the actual color value output. To emulate the appearance of dimming incandescent lamps may require a feedback system with color sensor to actively monitor and control the color. Phosphor-based LEDs This method involves coating LEDs of one color (mostly blue LEDs made of InGaN) with phosphors of different colors to form white light; the resultant LEDs are called phosphor-based or phosphor-converted white LEDs (pcLEDs). A fraction of the blue light undergoes the Stokes shift, which transforms it from shorter wavelengths to longer. Depending on the original LED's color, various color phosphors are used. Using several phosphor layers of distinct colors broadens the emitted spectrum, effectively raising the color rendering index (CRI). Phosphor-based LEDs have efficiency losses due to heat loss from the Stokes shift and also other phosphor-related issues. Their luminous efficacies compared to normal LEDs depend on the spectral distribution of the resultant light output and the original wavelength of the LED itself. For example, the luminous efficacy of a typical YAG yellow phosphor based white LED ranges from 3 to 5 times the luminous efficacy of the original blue LED because of the human eye's greater sensitivity to yellow than to blue (as modeled in the luminosity function). Due to the simplicity of manufacturing, the phosphor method is still the most popular method for making high-intensity white LEDs. The design and production of a light source or light fixture using a monochrome emitter with phosphor conversion is simpler and cheaper than a complex RGB system, and the majority of high-intensity white LEDs presently on the market are manufactured using phosphor light conversion. Among the challenges being faced to improve the efficiency of LED-based white light sources is the development of more efficient phosphors. As of 2010, the most efficient yellow phosphor is still the YAG phosphor, with less than 10% Stokes shift loss. Losses attributable to internal optical losses due to re-absorption in the LED chip and in the LED packaging itself account typically for another 10% to 30% of efficiency loss. Currently, in the area of phosphor LED development, much effort is being spent on optimizing these devices to higher light output and higher operation temperatures. For instance, the efficiency can be raised by adapting better package design or by using a more suitable type of phosphor. Conformal coating process is frequently used to address the issue of varying phosphor thickness. Some phosphor-based white LEDs encapsulate InGaN blue LEDs inside phosphor-coated epoxy. Alternatively, the LED might be paired with a remote phosphor, a preformed polycarbonate piece coated with the phosphor material. Remote phosphors provide more diffuse light, which is desirable for many applications. Remote phosphor designs are also more tolerant of variations in the LED emissions spectrum. A common yellow phosphor material is cerium-doped yttrium aluminium garnet (Ce3+:YAG). White LEDs can also be made by coating near-ultraviolet (NUV) LEDs with a mixture of high-efficiency europium-based phosphors that emit red and blue, plus copper and aluminium-doped zinc sulfide (ZnS:Cu, Al) that emits green. This is a method analogous to the way fluorescent lamps work. This method is less efficient than blue LEDs with YAG:Ce phosphor, as the Stokes shift is larger, so more energy is converted to heat, but yields light with better spectral characteristics, which render color better. Due to the higher radiative output of the ultraviolet LEDs than of the blue ones, both methods offer comparable brightness. A concern is that UV light may leak from a malfunctioning light source and cause harm to human eyes or skin. Other white LEDs Another method used to produce experimental white light LEDs used no phosphors at all and was based on homoepitaxially grown zinc selenide (ZnSe) on a ZnSe substrate that simultaneously emitted blue light from its active region and yellow light from the substrate. A new style of wafers composed of gallium-nitride-on-silicon (GaN-on-Si) is being used to produce white LEDs using 200-mm silicon wafers. This avoids the typical costly sapphire substrate in relatively small 100- or 150-mm wafer sizes. The sapphire apparatus must be coupled with a mirror-like collector to reflect light that would otherwise be wasted. It was predicted that since 2020, 40% of all GaN LEDs are made with GaN-on-Si. Manufacturing large sapphire material is difficult, while large silicon material is cheaper and more abundant. LED companies shifting from using sapphire to silicon should be a minimal investment. Organic light-emitting diodes (OLEDs) In an organic light-emitting diode (OLED), the electroluminescent material composing the emissive layer of the diode is an organic compound. The organic material is electrically conductive due to the delocalization of pi electrons caused by conjugation over all or part of the molecule, and the material therefore functions as an organic semiconductor. The organic materials can be small organic molecules in a crystalline phase, or polymers. The potential advantages of OLEDs include thin, low-cost displays with a low driving voltage, wide viewing angle, and high contrast and color gamut. Polymer LEDs have the added benefit of printable and flexible displays. OLEDs have been used to make visual displays for portable electronic devices such as cellphones, digital cameras, lighting and televisions. Types LEDs are made in different packages for different applications. A single or a few LED junctions may be packed in one miniature device for use as an indicator or pilot lamp. An LED array may include controlling circuits within the same package, which may range from a simple resistor, blinking or color changing control, or an addressable controller for RGB devices. Higher-powered white-emitting devices will be mounted on heat sinks and will be used for illumination. Alphanumeric displays in dot matrix or bar formats are widely available. Special packages permit connection of LEDs to optical fibers for high-speed data communication links. Miniature These are mostly single-die LEDs used as indicators, and they come in various sizes from 2 mm to 8 mm, through-hole and surface mount packages. Typical current ratings range from around 1 mA to above 20 mA. Multiple LED dies attached to a flexible backing tape form an LED strip light. Common package shapes include round, with a domed or flat top, rectangular with a flat top (as used in bar-graph displays), and triangular or square with a flat top. The encapsulation may also be clear or tinted to improve contrast and viewing angle. Infrared devices may have a black tint to block visible light while passing infrared radiation. Ultra-high-output LEDs are designed for viewing in direct sunlight. 5 V and 12 V LEDs are ordinary miniature LEDs that have a series resistor for direct connection to a 5V or 12V supply. High-power High-power LEDs (HP-LEDs) or high-output LEDs (HO-LEDs) can be driven at currents from hundreds of mA to more than an ampere, compared with the tens of mA for other LEDs. Some can emit over a thousand lumens. LED power densities up to 300 W/cm2 have been achieved. Since overheating is destructive, the HP-LEDs must be mounted on a heat sink to allow for heat dissipation. If the heat from an HP-LED is not removed, the device fails in seconds. One HP-LED can often replace an incandescent bulb in a flashlight, or be set in an array to form a powerful LED lamp. Some well-known HP-LEDs in this category are the Nichia 19 series, Lumileds Rebel Led, Osram Opto Semiconductors Golden Dragon, and Cree X-lamp. As of September 2009, some HP-LEDs manufactured by Cree now exceed 105 lm/W. Examples for Haitz's law—which predicts an exponential rise in light output and efficacy of LEDs over time—are the CREE XP-G series LED, which achieved 105lm/W in 2009 and the Nichia 19 series with a typical efficacy of 140lm/W, released in 2010. AC-driven LEDs developed by Seoul Semiconductor can operate on AC power without a DC converter. For each half-cycle, part of the LED emits light and part is dark, and this is reversed during the next half-cycle. The efficiency of this type of HP-LED is typically 40lm/W. A large number of LED elements in series may be able to operate directly from line voltage. In 2009, Seoul Semiconductor released a high DC voltage LED, named 'Acrich MJT', capable of being driven from AC power with a simple controlling circuit. The low-power dissipation of these LEDs affords them more flexibility than the original AC LED design. Application-specific variations Flashing Flashing LEDs are used as attention seeking indicators without requiring external electronics. Flashing LEDs resemble standard LEDs but they contain an integrated voltage regulator and a multivibrator circuit that causes the LED to flash with a typical period of one second. In diffused lens LEDs, this circuit is visible as a small black dot. Most flashing LEDs emit light of one color, but more sophisticated devices can flash between multiple colors and even fade through a color sequence using RGB color mixing. Flashing SMD LEDs in the 0805 and other size formats have been available since early 2019. Bi-color Bi-color LEDs contain two different LED emitters in one case. There are two types of these. One type consists of two dies connected to the same two leads antiparallel to each other. Current flow in one direction emits one color, and current in the opposite direction emits the other color. The other type consists of two dies with separate leads for both dies and another lead for common anode or cathode so that they can be controlled independently. The most common bi-color combination is red/traditional green, however, other available combinations include amber/traditional green, red/pure green, red/blue, and blue/pure green. RGB tri-color Tri-color LEDs contain three different LED emitters in one case. Each emitter is connected to a separate lead so they can be controlled independently. A four-lead arrangement is typical with one common lead (anode or cathode) and an additional lead for each color. Others, however, have only two leads (positive and negative) and have a built-in electronic controller. RGB LEDs consist of one red, one green, and one blue LED. By independently adjusting each of the three, RGB LEDs are capable of producing a wide color gamut. Unlike dedicated-color LEDs, however, these do not produce pure wavelengths. Modules may not be optimized for smooth color mixing. Decorative-multicolor Decorative-multicolor LEDs incorporate several emitters of different colors supplied by only two lead-out wires. Colors are switched internally by varying the supply voltage. Alphanumeric Alphanumeric LEDs are available in seven-segment, starburst, and dot-matrix format. Seven-segment displays handle all numbers and a limited set of letters. Starburst displays can display all letters. Dot-matrix displays typically use 5×7 pixels per character. Seven-segment LED displays were in widespread use in the 1970s and 1980s, but rising use of liquid crystal displays, with their lower power needs and greater display flexibility, has reduced the popularity of numeric and alphanumeric LED displays. Digital RGB Digital RGB addressable LEDs contain their own "smart" control electronics. In addition to power and ground, these provide connections for data-in, data-out, clock and sometimes a strobe signal. These are connected in a daisy chain. Data sent to the first LED of the chain can control the brightness and color of each LED independently of the others. They are used where a combination of maximum control and minimum visible electronics are needed such as strings for Christmas and LED matrices. Some even have refresh rates in the kHz range, allowing for basic video applications. These devices are known by their part number (WS2812 being common) or a brand name such as NeoPixel. Filament An LED filament consists of multiple LED chips connected in series on a common longitudinal substrate that forms a thin rod reminiscent of a traditional incandescent filament. These are being used as a low-cost decorative alternative for traditional light bulbs that are being phased out in many countries. The filaments use a rather high voltage, allowing them to work efficiently with mains voltages. Often a simple rectifier and capacitive current limiting are employed to create a low-cost replacement for a traditional light bulb without the complexity of the low voltage, high current converter that single die LEDs need. Usually, they are packaged in bulb similar to the lamps they were designed to replace, and filled with inert gas at slightly lower than ambient pressure to remove heat efficiently and prevent corrosion. Chip-on-board arrays Surface-mounted LEDs are frequently produced in chip on board (COB) arrays, allowing better heat dissipation than with a single LED of comparable luminous output. The LEDs can be arranged around a cylinder, and are called "corn cob lights" because of the rows of yellow LEDs. Considerations for use Power sources The current in an LED or other diodes rises exponentially with the applied voltage (see Shockley diode equation), so a small change in voltage can cause a large change in current. Current through the LED must be regulated by an external circuit such as a constant current source to prevent damage. Since most common power supplies are (nearly) constant-voltage sources, LED fixtures must include a power converter, or at least a current-limiting resistor. In some applications, the internal resistance of small batteries is sufficient to keep current within the LED rating. Electrical polarity Unlike a traditional incandescent lamp, an LED will light only when voltage is applied in the forward direction of the diode. No current flows and no light is emitted if voltage is applied in the reverse direction. If the reverse voltage exceeds the breakdown voltage, a large current flows and the LED will be damaged. If the reverse current is sufficiently limited to avoid damage, the reverse-conducting LED is a useful noise diode. Safety and health Certain blue LEDs and cool-white LEDs can exceed safe limits of the so-called blue-light hazard as defined in eye safety specifications such as "ANSI/IESNA RP-27.1–05: Recommended Practice for Photobiological Safety for Lamp and Lamp Systems". One study showed no evidence of a risk in normal use at domestic illuminance, and that caution is only needed for particular occupational situations or for specific populations. In 2006, the International Electrotechnical Commission published IEC 62471 Photobiological safety of lamps and lamp systems, replacing the application of early laser-oriented standards for classification of LED sources. While LEDs have the advantage over fluorescent lamps, in that they do not contain mercury, they may contain other hazardous metals such as lead and arsenic. In 2016 the American Medical Association (AMA) issued a statement concerning the possible adverse influence of blueish street lighting on the sleep-wake cycle of city-dwellers. Industry critics claim exposure levels are not high enough to have a noticeable effect. Advantages Efficiency: LEDs emit more lumens per watt than incandescent light bulbs. The efficiency of LED lighting fixtures is not affected by shape and size, unlike fluorescent light bulbs or tubes. Color: LEDs can emit light of an intended color without using any color filters as traditional lighting methods need. This is more efficient and can lower initial costs. Size: LEDs can be very small (smaller than 2 mm2) and are easily attached to printed circuit boards. Warmup time: LEDs light up very quickly. A typical red indicator LED achieves full brightness in under a microsecond. LEDs used in communications devices can have even faster response times. Cycling: LEDs are ideal for uses subject to frequent on-off cycling, unlike incandescent and fluorescent lamps that fail faster when cycled often, or high-intensity discharge lamps (HID lamps) that require a long time before restarting. Dimming: LEDs can very easily be dimmed either by pulse-width modulation or lowering the forward current. This pulse-width modulation is why LED lights, particularly headlights on cars, when viewed on camera or by some people, seem to flash or flicker. This is a type of stroboscopic effect. Cool light: In contrast to most light sources, LEDs radiate very little heat in the form of IR that can cause damage to sensitive objects or fabrics. Wasted energy is dispersed as heat through the base of the LED. Slow failure: LEDs mainly fail by dimming over time, rather than the abrupt failure of incandescent bulbs. Lifetime: LEDs can have a relatively long useful life. One report estimates 35,000 to 50,000 hours of useful life, though time to complete failure may be shorter or longer. Fluorescent tubes typically are rated at about 10,000 to 25,000 hours, depending partly on the conditions of use, and incandescent light bulbs at 1,000 to 2,000 hours. Several DOE demonstrations have shown that reduced maintenance costs from this extended lifetime, rather than energy savings, is the primary factor in determining the payback period for an LED product. Shock resistance: LEDs, being solid-state components, are difficult to damage with external shock, unlike fluorescent and incandescent bulbs, which are fragile. Focus: The solid package of the LED can be designed to focus its light. Incandescent and fluorescent sources often require an external reflector to collect light and direct it in a usable manner. For larger LED packages total internal reflection (TIR) lenses are often used to the same effect. However, when large quantities of light are needed many light sources are usually deployed, which are difficult to focus or collimate towards the same target. Disadvantages Temperature dependence: LED performance largely depends on the ambient temperature of the operating environment – or thermal management properties. Overdriving an LED in high ambient temperatures may result in overheating the LED package, eventually leading to device failure. An adequate heat sink is needed to maintain long life. This is especially important in automotive, medical, and military uses where devices must operate over a wide range of temperatures, and require low failure rates. Voltage sensitivity: LEDs must be supplied with a voltage above their threshold voltage and a current below their rating. Current and lifetime change greatly with a small change in applied voltage. They thus require a current-regulated supply (usually just a series resistor for indicator LEDs). Color rendition: Most cool-white LEDs have spectra that differ significantly from a black body radiator like the sun or an incandescent light. The spike at 460 nm and dip at 500 nm can make the color of objects appear differently under cool-white LED illumination than sunlight or incandescent sources, due to metamerism, red surfaces being rendered particularly poorly by typical phosphor-based cool-white LEDs. The same is true with green surfaces. The quality of color rendition of an LED is measured by the Color Rendering Index (CRI). Area light source: Single LEDs do not approximate a point source of light giving a spherical light distribution, but rather a lambertian distribution. So, LEDs are difficult to apply to uses needing a spherical light field; however, different fields of light can be manipulated by the application of different optics or "lenses". LEDs cannot provide divergence below a few degrees. Light pollution: Because white LEDs emit more short wavelength light than sources such as high-pressure sodium vapor lamps, the increased blue and green sensitivity of scotopic vision means that white LEDs used in outdoor lighting cause substantially more sky glow. Efficiency droop: The efficiency of LEDs decreases as the electric current increases. Heating also increases with higher currents, which compromises LED lifetime. These effects put practical limits on the current through an LED in high power applications. Impact on wildlife: LEDs are much more attractive to insects than sodium-vapor lights, so much so that there has been speculative concern about the possibility of disruption to food webs. LED lighting near beaches, particularly intense blue and white colors, can disorient turtle hatchlings and make them wander inland instead. The use of "turtle-safe lighting" LEDs that emit only at narrow portions of the visible spectrum is encouraged by conservancy groups in order to reduce harm. Use in winter conditions: Since they do not give off much heat in comparison to incandescent lights, LED lights used for traffic control can have snow obscuring them, leading to accidents. Thermal runaway: Parallel strings of LEDs will not share current evenly due to the manufacturing tolerances in their forward voltage. Running two or more strings from a single current source may result in LED failure as the devices warm up. If forward voltage binning is not possible, a circuit is required to ensure even distribution of current between parallel strands. Applications LED uses fall into four major categories: Visual signals where light goes more or less directly from the source to the human eye, to convey a message or meaning Illumination where light is reflected from objects to give visual response of these objects Measuring and interacting with processes involving no human vision Narrow band light sensors where LEDs operate in a reverse-bias mode and respond to incident light, instead of emitting light Indicators and signs The low energy consumption, low maintenance and small size of LEDs has led to uses as status indicators and displays on a variety of equipment and installations. Large-area LED displays are used as stadium displays, dynamic decorative displays, and dynamic message signs on freeways. Thin, lightweight message displays are used at airports and railway stations, and as destination displays for trains, buses, trams, and ferries. One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights, and LED-based Christmas lights Because of their long life, fast switching times, and visibility in broad daylight due to their high output and focus, LEDs have been used in automotive brake lights and turn signals. The use in brakes improves safety, due to a great reduction in the time needed to light fully, or faster rise time, about 0.1 second faster than an incandescent bulb. This gives drivers behind more time to react. In a dual intensity circuit (rear markers and brakes) if the LEDs are not pulsed at a fast enough frequency, they can create a phantom array, where ghost images of the LED appear if the eyes quickly scan across the array. White LED headlamps are beginning to appear. Using LEDs has styling advantages because LEDs can form much thinner lights than incandescent lamps with parabolic reflectors. Due to the relative cheapness of low output LEDs, they are also used in many temporary uses such as glowsticks, throwies, and the photonic textile Lumalive. Artists have also used LEDs for LED art. Lighting With the development of high-efficiency and high-power LEDs, it has become possible to use LEDs in lighting and illumination. To encourage the shift to LED lamps and other high-efficiency lighting, in 2008 the US Department of Energy created the L Prize competition. The Philips Lighting North America LED bulb won the first competition on August 3, 2011, after successfully completing 18 months of intensive field, lab, and product testing. Efficient lighting is needed for sustainable architecture. As of 2011, some LED bulbs provide up to 150 lm/W and even inexpensive low-end models typically exceed 50 lm/W, so that a 6-watt LED could achieve the same results as a standard 40-watt incandescent bulb. The lower heat output of LEDs also reduces demand on air conditioning systems. Worldwide, LEDs are rapidly adopted to displace less effective sources such as incandescent lamps and CFLs and reduce electrical energy consumption and its associated emissions. Solar powered LEDs are used as street lights and in architectural lighting. The mechanical robustness and long lifetime are used in automotive lighting on cars, motorcycles, and bicycle lights. LED street lights are employed on poles and in parking garages. In 2007, the Italian village of Torraca was the first place to convert its street lighting to LEDs. Cabin lighting on recent Airbus and Boeing jetliners uses LED lighting. LEDs are also being used in airport and heliport lighting. LED airport fixtures currently include medium-intensity runway lights, runway centerline lights, taxiway centerline and edge lights, guidance signs, and obstruction lighting. LEDs are also used as a light source for DLP projectors, and to backlight LCD televisions (referred to as LED TVs) and laptop displays. RGB LEDs raise the color gamut by as much as 45%. Screens for TV and computer displays can be made thinner using LEDs for backlighting. LEDs are small, durable and need little power, so they are used in handheld devices such as flashlights. LED strobe lights or camera flashes operate at a safe, low voltage, instead of the 250+ volts commonly found in xenon flashlamp-based lighting. This is especially useful in cameras on mobile phones, where space is at a premium and bulky voltage-raising circuitry is undesirable. LEDs are used for infrared illumination in night vision uses including security cameras. A ring of LEDs around a video camera, aimed forward into a retroreflective background, allows chroma keying in video productions. LEDs are used in mining operations, as cap lamps to provide light for miners. Research has been done to improve LEDs for mining, to reduce glare and to increase illumination, reducing risk of injury to the miners. LEDs are increasingly finding uses in medical and educational applications, for example as mood enhancement. NASA has even sponsored research for the use of LEDs to promote health for astronauts. Data communication and other signalling Light can be used to transmit data and analog signals. For example, lighting white LEDs can be used in systems assisting people to navigate in closed spaces while searching necessary rooms or objects. Assistive listening devices in many theaters and similar spaces use arrays of infrared LEDs to send sound to listeners' receivers. Light-emitting diodes (as well as semiconductor lasers) are used to send data over many types of fiber optic cable, from digital audio over TOSLINK cables to the very high bandwidth fiber links that form the Internet backbone. For some time, computers were commonly equipped with IrDA interfaces, which allowed them to send and receive data to nearby machines via infrared. Because LEDs can cycle on and off millions of times per second, very high data bandwidth can be achieved. For that reason, Visible Light Communication (VLC) has been proposed as an alternative to the increasingly competitive radio bandwidth. By operating in the visible part of the electromagnetic spectrum, data can be transmitted without occupying the frequencies of radio communications. The main characteristic of VLC, lies on the incapacity of light to surpass physical opaque barriers. This characteristic can be considered a weak point of VLC, due to the susceptibility of interference from physical objects, but is also one of its many strengths: unlike radio waves, light waves are confined in the enclosed spaces they are transmitted, which enforces a physical safety barrier that requires a receptor of that signal to have physical access to the place where the transmission is occurring. A promising application of VLC lies on the Indoor Positioning System (IPS), an analogous to the GPS built to operate in enclosed spaces where the satellite transmissions that allow the GPS operation are hard to reach. For instance, commercial buildings, shopping malls, parking garages, as well as subways and tunnel systems are all possible applications for VLC-based indoor positioning systems. Additionally, once the VLC lamps are able to perform lighting at the same time as data transmission, it can simply occupy the installation of traditional single-function lamps. Other applications for VLC involve communication between appliances of a smart home or office. With increasing IoT-capable devices, connectivity through traditional radio waves might be subjected to interference. However, light bulbs with VLC capabilities would be able to transmit data and commands for such devices. Machine vision systems Machine vision systems often require bright and homogeneous illumination, so features of interest are easier to process. LEDs are often used. Barcode scanners are the most common example of machine vision applications, and many of those scanners use red LEDs instead of lasers. Optical computer mice use LEDs as a light source for the miniature camera within the mouse. LEDs are useful for machine vision because they provide a compact, reliable source of light. LED lamps can be turned on and off to suit the needs of the vision system, and the shape of the beam produced can be tailored to match the system's requirements. Biological detection The discovery of radiative recombination in Aluminum Gallium Nitride (AlGaN) alloys by U.S. Army Research Laboratory (ARL) led to the conceptualization of UV light emitting diodes (LEDs) to be incorporated in light induced fluorescence sensors used for biological agent detection. In 2004, the Edgewood Chemical Biological Center (ECBC) initiated the effort to create a biological detector named TAC-BIO. The program capitalized on Semiconductor UV Optical Sources (SUVOS) developed by the Defense Advanced Research Projects Agency (DARPA). UV induced fluorescence is one of the most robust techniques used for rapid real time detection of biological aerosols. The first UV sensors were lasers lacking in-field-use practicality. In order to address this, DARPA incorporated SUVOS technology to create a low cost, small, lightweight, low power device. The TAC-BIO detector's response time was one minute from when it sensed a biological agent. It was also demonstrated that the detector could be operated unattended indoors and outdoors for weeks at a time. Aerosolized biological particles will fluoresce and scatter light under a UV light beam. Observed fluorescence is dependent on the applied wavelength and the biochemical fluorophores within the biological agent. UV induced fluorescence offers a rapid, accurate, efficient and logistically practical way for biological agent detection. This is because the use of UV fluorescence is reagent less, or a process that does not require an added chemical to produce a reaction, with no consumables, or produces no chemical byproducts. Additionally, TAC-BIO can reliably discriminate between threat and non-threat aerosols. It was claimed to be sensitive enough to detect low concentrations, but not so sensitive that it would cause false positives. The particle counting algorithm used in the device converted raw data into information by counting the photon pulses per unit of time from the fluorescence and scattering detectors, and comparing the value to a set threshold. The original TAC-BIO was introduced in 2010, while the second generation TAC-BIO GEN II, was designed in 2015 to be more cost efficient as plastic parts were used. Its small, light-weight design allows it to be mounted to vehicles, robots, and unmanned aerial vehicles. The second generation device could also be utilized as an environmental detector to monitor air quality in hospitals, airplanes, or even in households to detect fungus and mold. Other applications The light from LEDs can be modulated very quickly so they are used extensively in optical fiber and free space optics communications. This includes remote controls, such as for television sets, where infrared LEDs are often used. Opto-isolators use an LED combined with a photodiode or phototransistor to provide a signal path with electrical isolation between two circuits. This is especially useful in medical equipment where the signals from a low-voltage sensor circuit (usually battery-powered) in contact with a living organism must be electrically isolated from any possible electrical failure in a recording or monitoring device operating at potentially dangerous voltages. An optoisolator also lets information be transferred between circuits that do not share a common ground potential. Many sensor systems rely on light as the signal source. LEDs are often ideal as a light source due to the requirements of the sensors. The Nintendo Wii's sensor bar uses infrared LEDs. Pulse oximeters use them for measuring oxygen saturation. Some flatbed scanners use arrays of RGB LEDs rather than the typical cold-cathode fluorescent lamp as the light source. Having independent control of three illuminated colors allows the scanner to calibrate itself for more accurate color balance, and there is no need for warm-up. Further, its sensors only need be monochromatic, since at any one time the page being scanned is only lit by one color of light. Since LEDs can also be used as photodiodes, they can be used for both photo emission and detection. This could be used, for example, in a touchscreen that registers reflected light from a finger or stylus. Many materials and biological systems are sensitive to, or dependent on, light. Grow lights use LEDs to increase photosynthesis in plants, and bacteria and viruses can be removed from water and other substances using UV LEDs for sterilization. Deep UV LEDs, with a spectra range 247 nm to 386 nm, have other applications, such as water/air purification, surface disinfection, epoxy curing, free-space nonline-of-sight communication, high performance liquid chromatography, UV curing and printing, phototherapy, medical/ analytical instrumentation, and DNA absorption. LEDs have also been used as a medium-quality voltage reference in electronic circuits. The forward voltage drop (about 1.7 V for a red LED or 1.2V for an infrared) can be used instead of a Zener diode in low-voltage regulators. Red LEDs have the flattest I/V curve above the knee. Nitride-based LEDs have a fairly steep I/V curve and are useless for this purpose. Although LED forward voltage is far more current-dependent than a Zener diode, Zener diodes with breakdown voltages below 3 V are not widely available. The progressive miniaturization of low-voltage lighting technology, such as LEDs and OLEDs, suitable to incorporate into low-thickness materials has fostered experimentation in combining light sources and wall covering surfaces for interior walls in the form of LED wallpaper. Research and development Key challenges LEDs require optimized efficiency to hinge on ongoing improvements such as phosphor materials and quantum dots. The process of down-conversion (the method by which materials convert more-energetic photons to different, less energetic colors) also needs improvement. For example, the red phosphors that are used today are thermally sensitive and need to be improved in that aspect so that they do not color shift and experience efficiency drop-off with temperature. Red phosphors could also benefit from a narrower spectral width to emit more lumens and becoming more efficient at converting photons. In addition, work remains to be done in the realms of current efficiency droop, color shift, system reliability, light distribution, dimming, thermal management, and power supply performance. Potential technology Perovskite LEDs (PLEDs) A new family of LEDs are based on the semiconductors called perovskites. In 2018, less than four years after their discovery, the ability of perovskite LEDs (PLEDs) to produce light from electrons already rivaled those of the best performing OLEDs. They have a potential for cost-effectiveness as they can be processed from solution, a low-cost and low-tech method, which might allow perovskite-based devices that have large areas to be made with extremely low cost. Their efficiency is superior by eliminating non-radiative losses, in other words, elimination of recombination pathways that do not produce photons; or by solving outcoupling problem (prevalent for thin-film LEDs) or balancing charge carrier injection to increase the EQE (external quantum efficiency). The most up-to-date PLED devices have broken the performance barrier by shooting the EQE above 20%. In 2018, Cao et al. and Lin et al. independently published two papers on developing perovskite LEDs with EQE greater than 20%, which made these two papers a mile-stone in PLED development. Their device have similar planar structure, i.e. the active layer (perovskite) is sandwiched between two electrodes. To achieve a high EQE, they not only reduced non-radiative recombination, but also utilized their own, subtly different methods to improve the EQE. In the work of Cao et al. , researchers targeted the outcoupling problem, which is that the optical physics of thin-film LEDs causes the majority of light generated by the semiconductor to be trapped in the device. To achieve this goal, they demonstrated that solution-processed perovskites can spontaneously form submicrometre-scale crystal platelets, which can efficiently extract light from the device. These perovskites are formed via the introduction of amino acid additives into the perovskite precursor solutions. In addition, their method is able to passivate perovskite surface defects and reduce nonradiative recombination. Therefore, by improving the light outcoupling and reducing nonradiative losses, Cao and his colleagues successfully achieved PLED with EQE up to 20.7%. In Lin and his colleague's work, however, they used a different approach to generate high EQE. Instead of modifying the microstructure of perovskite layer, they chose to adopt a new strategy for managing the compositional distribution in the device——an approach that simultaneously provides high luminescence and balanced charge injection. In other words, they still used flat emissive layer, but tried to optimize the balance of electrons and holes injected into the perovskite, so as to make the most efficient use of the charge carriers. Moreover, in the perovskite layer, the crystals are perfectly enclosed by MABr additive (where MA is CH3NH3). The MABr shell passivates the nonradiative defects that would otherwise be present perovskite crystals, resulting in reduction of the nonradiative recombination. Therefore, by balancing charge injection and decreasing nonradiative losses, Lin and his colleagues developed PLED with EQE up to 20.3%. See also History of display technology LED tattoo Light-emitting electrochemical cell List of LED failure modes List of light sources Photovoltaics SMD LED module Superluminescent diode MicroLED Solar lamp Solid-state lighting Thermal management of high-power LEDs UV curing References Further reading External links Building a do-it-yourself LED Color cycling LED in a single two pin package, LED lamps Optical diodes Display technology Signage 20th-century inventions Japanese inventions	[ 0.643578052520752, 0.21668684482574463, -0.12197260558605194, -0.07934271544218063, -0.2581304609775543, -0.31560638546943665, -0.23717272281646729, 0.027327174320816994, -0.03803014010190964, -0.31396055221557617, -0.2601335048675537, -0.013070669956505299, -0.8425561785697937, 0.41544210...
18291	https://en.wikipedia.org/wiki/Luxembourgish	Luxembourgish	Luxembourgish ( ; also Luxemburgish, Luxembourgian, Letzebu(e)rgesch; Luxembourgish: ) is a West Germanic language that is spoken mainly in Luxembourg. About 600,000 people speak Luxembourgish worldwide. As a standard form of the Moselle Franconian language, Luxembourgish has similarities with other varieties of High German and the wider group of West Germanic languages. The status of Luxembourgish as an official language in Luxembourg, and the existence there of a regulatory body, have removed Luxembourgish, at least in part, from the domain of Standard German, its traditional . History Language family Luxembourgish belongs to the West Central German group of High German languages and is the primary example of a Moselle Franconian language. Usage Luxembourgish is considered the national language of Luxembourg and also one of the three administrative languages, alongside German and French. In Luxembourg, 77% of citizens can speak Luxembourgish. Luxembourgish is also spoken in the Arelerland region of Belgium (part of the Province of Luxembourg) and in small parts of Lorraine in France. In the German Eifel and Hunsrück regions, similar local Moselle Franconian dialects of German are spoken. The language is also spoken by a few descendants of Luxembourg immigrants in the United States and Canada. Other Moselle Franconian dialects are spoken by ethnic Germans long settled in Transylvania, Romania (Siebenbürgen). Moselle Franconian dialects outside the Luxembourg state border tend to have far fewer French loan words, and these mostly remain from the French Revolution. The political party that places the greatest importance on promoting, using and preserving Luxembourgish is the Alternative Democratic Reform Party (ADR) and its electoral success in the 1999 election pushed the CSV-DP government to make knowledge of it a criterion for naturalisation. It is currently also the only political party in Luxembourg that wishes to implement written laws also in Luxembourgish and that wants Luxembourgish to be an officially recognized language of the European Union. In this context, in 2005, politician Jean Asselborn of LSAP rejected a demand made by ADR to make Luxembourgish an official language of the European Union citing financial reasons and also that German and French being already official languages would be sufficient for the needs of Luxembourg. Varieties There are several distinct dialect forms of Luxembourgish including Areler (from Arlon), Eechternoacher (Echternach), Kliärrwer (Clervaux), Miseler (Moselle), Stater (Luxembourg), Veiner (Vianden), Minetter (Southern Luxembourg) and Weelzer (Wiltz). Further small vocabulary differences may be seen even between small villages. Increasing mobility of the population and the dissemination of the language through mass media such as radio and television are leading to a gradual standardisation towards a "Standard Luxembourgish" through the process of koineization. Surrounding languages There is no distinct geographic boundary between the use of Luxembourgish and the use of other closely related High German dialects (for example, Lorraine Franconian); it instead forms a dialect continuum of gradual change. Spoken Luxembourgish is relatively hard to understand for speakers of German who are generally not familiar with Moselle Franconian dialects (or at least other West Central German dialects). However, they can usually read the language to some degree. For those Germans familiar with Moselle Franconian dialects, it is relatively easy to understand and speak Luxembourgish as far as the everyday vocabulary is concerned. However, the large number of French loanwords in Luxembourgish may hamper communication about certain topics, or with certain speakers (who use many French loanwords). Written Luxembourgish Standardisation A number of proposals for standardising the orthography of Luxembourgish can be documented, going back to the middle of the 19th century. There was no officially recognised system, however, until the adoption of the "OLO" () on 5 June 1946. This orthography provided a system for speakers of all varieties of Luxembourgish to transcribe words the way they pronounced them, rather than imposing a single, standard spelling for the words of the language. The rules explicitly rejected certain elements of German orthography (, the use of and , the capitalisation of nouns). Similarly, new principles were adopted for the spelling of French loanwords. , , , (cf. German , , , ) , , , (cf. French , , , ) This proposed orthography, so different from existing "foreign" standards that people were already familiar with, did not enjoy widespread approval. A more successful standard eventually emerged from the work of the committee of specialists charged with the task of creating the Luxemburger Wörterbuch, published in 5 volumes between 1950 and 1977. The orthographic conventions adopted in this decades-long project, set out in Bruch (1955), provided the basis of the standard orthography that became official on 10 October 1975. Modifications to this standard were proposed by the Permanent Council of the Luxembourguish language and adopted officially in the spelling reform of 30 July 1999. A detailed explanation of current practice for Luxembourgish can be found in Schanen & Lulling (2003). Alphabet The Luxembourgish alphabet consists of the 26 Latin letters plus three letters with diacritics: , , and . In loanwords from French and Standard German, other diacritics are usually preserved: French: , , , etc. German: , (from German ), etc. In German loanwords, the digraphs and indicate the diphthong , which does not appear in native words. Orthography of vowels {\| class="wikitable" \|+ Monophthongs ! Spelling ! IPA ! Example \|- \| rowspan="2" style="vertical-align: middle;" \| a \| \| \|- \| rowspan="2" style="vertical-align: middle;" \| \| \|- \| aa \| \|- \| ä \| rowspan="2" style="vertical-align: middle;" \| \| \|- \| rowspan="2" style="vertical-align: middle;" \| e \| \|- \| rowspan="2" style="vertical-align: middle;" \| \| \|- \| ë \| \|- \| é \| \| \|- \| ee \| \| \|- \| rowspan="2" style="vertical-align: middle;" \| i \| \| \|- \| rowspan="2" style="vertical-align: middle;" \| \| \|- \| ii \| \|- \| rowspan="2" style="vertical-align: middle;" \| o \| \| \|- \| rowspan="2" \| \| \|- \| oo \| \|- \| rowspan="2" style="vertical-align: middle;" \| u \| \| \|- \| rowspan="2" style="vertical-align: middle;" \| \| \|- \| uu \| \|} {\| class="wikitable" \|+ Diphthongs ! Spelling ! IPA ! Example \|- \| ai \| rowspan="2" style="vertical-align: middle;" \| \| \|- \| ei \| \|- \| äi \| \| \|- \| rowspan="2" style="vertical-align: middle;" \| au \| \| \|- \| \| \|- \| éi \| \| \|- \| \| rowspan="2" \| \| \|- \| ier \| \|- \| ou \| \| \|- \| ue \| rowspan="2" \| \| \|- \| uer \| \|} {\| class="wikitable" \|+ r-vocalization ! Spelling ! IPA ! Example \|- \| ar \| rowspan="2" \| \| \|- \| aar \| \|- \| är \| rowspan="2" \| \| \|- \| äer \| \|- \| er \| \| \|- \| ir \| rowspan="2" \| \| \|- \| ier \| \|- \| or \| rowspan="2" \| \| \|- \| oer \| \|- \| ur \| rowspan="2" \| \| \|- \| uer \| \|} Eifeler Regel Like many other varieties of Western High German, Luxembourgish has a rule of final n-deletion in certain contexts. The effects of this rule (known as the "Eifel Rule") are indicated in writing, and therefore must be taken into account when spelling words and morphemes ending in or . For example: "when I go", but "when we go" "thirty-five", but "forty-five". Phonology Consonants The consonant inventory of Luxembourgish is quite similar to that of Standard German. occurs only in loanwords from Standard German. Just as for many native speakers of Standard German, it tends to be simplified to word-initially. For example, Pflicht ('obligation') is realised as or, in careful speech, . is realised as when it occurs after , e.g. zwee ('two'). appears only in a few words, such as spadséieren ('to go for a walk'). occurs only in loanwords from English. have two types of allophones: alveolo-palatal and uvular . The latter occur before back vowels, and the former occur in all other positions. The allophone appears only in a few words, and speakers increasingly fail to distinguish between the alveolo-palatal allophones of and the postalveolar phonemes . Younger speakers tend to vocalize a word-final to . Vowels The front rounded vowels appear only in loanwords from French and Standard German. In loanwords from French, nasal also occur. has two allophones: Before velars: close-mid front unrounded , which, for some speakers, may be open-mid , especially before . The same variation in height applies to , which may be as open as . All other positions: mid central vowel, more often slightly rounded than unrounded . Phonetically, the long mid vowels are raised close-mid (near-close) and may even overlap with . before is realised as . is the long variant of , not , which does not have a long counterpart. appears only in loanwords from Standard German. The first elements of may be phonetically short in fast speech or in unstressed syllables. The and contrasts arose from the former lexical tone contrast; the shorter were used in words with Accent 1, and the lengthened were used in words with Accent 2. Grammar Nominal syntax Luxembourgish has three genders (masculine, feminine, and neuter), and three cases (nominative, accusative, and dative). These are marked morphologically on determiners and pronouns. As in German, there is no morphological gender distinction in the plural. The forms of the articles and of some selected determiners are given below: As seen above, Luxembourgish has plural forms of en ("a, an"), namely eng in the nominative/accusative and engen in the dative. They are not used as indefinite articles, which—as in German and English—do not exist in the plural, but they do occur in the compound pronouns wéi en ("what, which") and sou en ("such"). For example: wéi eng Saachen ("what things"); sou eng Saachen ("such things"). Moreover, they are used before numbers to express an estimation: eng 30.000 Spectateuren ("some 30,000 spectators"). Distinct nominative forms survive in a few nominal phrases such as der Däiwel ("the devil") and eiser Herrgott ("our Lord"). Rare examples of the genitive are also found: Enn des Mounts ("end of the month"), Ufanks der Woch ("at the beginning of the week"). The functions of the genitive are normally expressed using a combination of the dative and a possessive determiner: e.g. dem Mann säi Buch (lit. "to the man his book", i.e. "the man's book"). This is known as a periphrastic genitive, and is a phenomenon also commonly seen in dialectal and colloquial German, and in Dutch. The forms of the personal pronouns are given in the following table (unstressed forms appear in parentheses): The 2pl form is also used as a polite singular (like French vous, see T-V distinction); the forms are capitalised in writing: Wéi hues du de Concert fonnt? ("How did you [informal sg.] like the concert?") Wéi hutt dir de Concert fonnt? ("How did you [informal pl.] like the concert?") Wéi hutt Dir de Concert fonnt? ("How did you [formal sg. or pl.] like the concert?") Like most varieties of colloquial German, but even more invariably, Luxembourgish uses definite articles with personal names. They are obligatory and not to be translated: De Serge ass an der Kichen. ("Serge is in the kitchen.") A feature Luxembourgish shares with only some western dialects of German is that women and girls are most often referred to with forms of the neuter pronoun hatt: Dat ass d'Nathalie. Hatt ass midd, well et vill a sengem Gaart geschafft huet. ("That's Nathalie. She is tired because she has worked a lot in her garden.") Adjectives Luxembourgish morphology distinguishes two types of adjective: attributive and predicative. Predicative adjectives appear with verbs like sinn ("to be"), and receive no extra ending: De Mann ass grouss. (masculine, "The man is tall.") D'Fra ass grouss. (feminine, "The woman is tall.") D'Meedchen ass grouss. (neuter, "The girl is tall.") D'Kanner si grouss. (plural, "The children are tall.") Attributive adjectives are placed before the noun they describe, and change their ending according to the grammatical gender, number, and case: de grousse Mann (masculine) déi grouss Fra (feminine) dat grousst Meedchen (neuter) déi grouss Kanner (plural) Curiously, the definite article changes with the use of an attributive adjective: feminine d' goes to déi (or di), neuter d' goes to dat, and plural d' changes to déi. The comparative in Luxembourgish is formed analytically, i.e. the adjective itself is not altered (compare the use of -er in German and English; tall → taller, klein → kleiner). Instead it is formed using the adverb méi: e.g. schéin → méi schéin Lëtzebuerg ass méi schéi wéi Esch. ("Luxembourg is prettier than Esch.") The superlative involves a synthetic form consisting of the adjective and the suffix -st: e.g. schéin → schéinst (compare German schönst, English prettiest). Attributive modification requires the emphatic definite article and the inflected superlative adjective: dee schéinste Mann ("the most handsome man") déi schéinst Fra ("the prettiest woman") Predicative modification uses either the same adjectival structure or the adverbial structure am+ -sten: e.g. schéin → am schéinsten: Lëtzebuerg ass dee schéinsten / deen allerschéinsten / am schéinsten. ("Luxembourg is the most beautiful (of all).") Some common adjectives have exceptional comparative and superlative forms: gutt, besser, am beschten ("good, better, best") vill, méi, am meeschten ("much, more, most") wéineg, manner, am mannsten ("few, fewer, fewest") Several other adjectives also have comparative forms. However, these are not commonly used as normal comparatives, but in special senses: al ("old") → eeler Leit ("elderly people"), but: méi al Leit ("older people, people older than X") fréi ("early") → de fréiere President ("the former president"), but: e méi fréien Termin ("an earlier appointment") laang ("long") → viru längerer Zäit ("some time ago"), but: eng méi laang Zäit ("a longer period of time") Word order Luxembourgish exhibits "verb second" word order in clauses. More specifically, Luxembourgish is a V2-SOV language, like German and Dutch. In other words, we find the following finite clausal structures: the finite verb in second position in declarative clauses and wh-questions Ech kafen en Hutt. Muer kafen ech en Hutt. (lit. "I buy a hat. Tomorrow buy I a hat.) Wat kafen ech haut? (lit. "What buy I today?") the finite verb in first position in yes/no questions and finite imperatives Bass de midd? ("Are you tired?") Gëff mer deng Hand! ("Give me your hand!") the finite verb in final position in subordinate clauses Du weess, datt ech midd sinn. (lit. "You know, that I tired am.") Non-finite verbs (infinitives and participles) generally appear in final position: compound past tenses Ech hunn en Hutt kaf. (lit. "I have a hat bought.") infinitival complements Du solls net esou vill Kaffi drénken. (lit. "You should not so much coffee drink.") infinitival clauses (e.g., used as imperatives) Nëmme Lëtzebuergesch schwätzen! (lit. "Only Luxembourgish speak!") These rules interact so that in subordinate clauses, the finite verb and any non-finite verbs must all cluster at the end. Luxembourgish allows different word orders in these cases: Hie freet, ob ech komme kann. (cf. German Er fragt, ob ich kommen kann.) (lit. "He asks if I come can.") Hie freet, ob ech ka kommen. (cf. Dutch Hij vraagt of ik kan komen.) (lit. "He asks if I can come.") This is also the case when two non-finite verb forms occur together: Ech hunn net kënne kommen. (cf. Dutch Ik heb niet kunnen komen.) (lit, "I have not be-able to-come") Ech hunn net komme kënnen. (cf. German Ich habe nicht kommen können.) (lit, "I have not to-come be-able") Luxembourgish (like Dutch and German) allows prepositional phrases to appear after the verb cluster in subordinate clauses: alles, wat Der ëmmer wollt wëssen iwwer Lëtzebuerg (lit. "everything what you always wanted know about Luxembourg") Vocabulary Luxembourgish has borrowed many French words. For example, the word for a bus driver is Buschauffeur (as in Dutch and Swiss German), which would be Busfahrer in German and chauffeur de bus in French. Some words are different from Standard German, but have equivalents in German dialects. An example is Gromperen (potatoes – German: Kartoffeln). Other words are exclusive to Luxembourgish. Selected common phrases Note: Words spoken in sound clip do not reflect all words on this list. Neologisms Neologisms in Luxembourgish include both entirely new words, and the attachment of new meanings to old words in everyday speech. The most recent neologisms come from the English language in the fields of telecommunications, computer science, and the Internet. Recent neologisms in Luxembourgish include: direct loans from English: Browser, Spam, CD, Fitness, Come-back, Terminal, Hip, Cool, Tip-top also found in German: Sichmaschinn (search engine, German: Suchmaschine), schwaarzt Lach (black hole, German: Schwarzes Loch), Handy (mobile phone), Websäit (webpage, German: Webseite) native Luxembourgish déck as an emphatic like ganz and voll, e.g. Dëse Kuch ass déck gutt! ("This cake is really good!") recent expressions, used mainly by teenagers: oh mëllen! ("oh crazy"), en décke gelénkt ("you've been tricked") or cassé (French for "(you've been) owned") Academic projects Between 2000 and 2002, Luxembourgish linguist Jérôme Lulling compiled a lexical database of 125,000-word forms as the basis for the first Luxembourgish spellchecker (Projet C.ORT.IN.A). The LaF (Lëtzebuergesch als Friemsprooch – Luxembourgish as a Foreign Language) is a set of four language proficiency certifications for Luxembourgish and follows the ALTE framework of language examination standards. The tests are administered by the Institut National des Langues Luxembourg. The "Centre for Luxembourg Studies" at the University of Sheffield was founded in 1995 on the initiative of Professor Gerald Newton. It is supported by the government of Luxembourg which funds an endowed chair in Luxembourg Studies at the university. The first class of students to study the language outside of the country as undergraduate students began their studies at the 'Centre for Luxembourg Studies' at Sheffield in the academic year 2011–2012. Claims of endangered status UNESCO declared Luxembourgish to be an endangered language in 2019, adding it to its Atlas of the World's Languages in Danger. Additionally, some local media have argued that the Luxembourgish language is at risk of disappearing, and that it should be considered an endangered language. Even though the government claims that more people than ever are able to speak Luxembourgish, these are absolute numbers and often include the many naturalized citizens who have passed the Sproochentest, a language test that certifies the knowledge of merely A.2. in speaking and B.1. in understanding. Luxembourgish language expert and historian Alain Atten argues that not only the absolute number of Luxembourgish speakers should be considered when defining the status of a language, but also the proportion of speakers in a country. Noting that the proportion of native Luxembourgish speakers has decreased in recent decades, Atten believes that Luxembourgish will inevitably disappear, stating: "It is simple math, if there are about 70% foreigners and about 30% Luxembourgers (which is the case in Luxembourg City), then it can impossibly be said that luxembourgish is thriving. That would be very improbable." Alain Atten also points out that the situation is even more dramatic, since the cited percentages take only the residents of Luxembourg into account, excluding the 200,000 cross-border-workers present in the country on a daily basis. This group plays a major role in the daily use of languages in Luxembourg, thus further lowering the percentage of Luxembourgish speakers present in the country. The following numbers are based on statistics by STATEC (those since 2011) and show that the percentage of the population that is able to speak Luxembourgish has been constantly diminishing for years (Note that the 200,000 cross-border workers are not included in this statistic): It has also been argued that two very similar languages, Alsatian and Lorraine Franconian, which were very broadly spoken by the local populations at the beginning of the 20th century in Alsace and in Lorraine respectively, have been nearly completely supplanted by French, and that a similar fate could also be possible for Luxembourgish. Another example of the replacement of Luxembourgish by French occurred in Arelerland (historically a part of Luxembourg, today in Belgium), where the vast majority of the local population spoke Luxembourgish as a native language well into the 20th century. Today, Luxembourgish is nearly extinct in this region, having been replaced by French. According to some Luxembourgish news media and members of Actioun Lëtzebuergesch (an association for the preservation and promotion of the language), the biggest threat to the existence of Luxembourgish is indeed French, since French is the predominant language of most official documents and street signs in Luxembourg, thus considerably weakening the possibilitiy for Luxembourgish learners to practice the newly learned language. In most cases this passively forces expats to learn French instead of Luxembourgish. In 2021 it was announced that public announcements in Luxembourgish (and in German as well) at Luxembourg Airport would cease; it would only be using French and English for future public announcements. This will cause Luxembourgish disappear from use at Luxembourg Airport, after being used for many decades. Actioun Lëtzebuergesch declared itself to be hugely upset by this new governmental measure, citing that other airports in the world seem to have no problems making public announcements in multiple languages. According to a poll conducted by AL, 92.84% of the Luxembourgish population wished to have public announcements to be made in Luxembourgish at Luxembourg Airport. Additionally, all written signs at Luxembourg Airport are only in French and English. This non-use of Luxembourgish and German (two official languages of Luxembourg) have fueled claims of a language discrimination, some pointing out that other airports seem to have no difficulties using up to 4 different languages in written signs. (Palma de Mallorca Airport for example uses Mallorquí, Spanish, English, and German, the latter two not even being official languages of the country) Further fears of Luxembourgish disappearing or being replaced by French have been fueled in 2021 when ASTI (Association de Soutien aux Travailleurs Immigrés) stated that it would wish to see Luxembourgish be removed as the national language of Luxembourg (as written in the constitution), claiming that the national language of Luxembourg should by law be defined as the one that is most used in the local population, hinting that French would be the better choice. See also Erna Hennicot-Schoepges Literature of Luxembourg Luxembourgish Swadesh List Multilingualism in Luxembourg Notes and references Notes References Bibliography Bruch, Robert. (1955) Précis de grammaire luxembourgeoise. Bulletin Linguistique et Ethnologique de l'Institut Grand-Ducal, Luxembourg, Linden. (2nd edition of 1968) Schanen, François and Lulling, Jérôme. (2003) Introduction à l'orthographe luxembourgeoise. (text available in French and Luxembourgish) Further reading In English NEWTON, Gerald (ed.), Luxembourg and Lëtzebuergesch: Language and Communication at the Crossroads of Europe, Oxford, 1996, In French BRAUN, Josy, et al. (en coll. avec Projet Moien), Grammaire de la langue luxembourgeoise. Luxembourg, Ministère de l'Éducation nationale et de la Formation professionnelle 2005. SCHANEN, François, Parlons Luxembourgeois, Langue et culture linguistique d'un petit pays au coeur de l'Europe. Paris, L'Harmattan 2004, SCHANEN, François / ZIMMER, Jacqui, 1,2,3 Lëtzebuergesch Grammaire. Band 1: Le groupe verbal. Band 2: Le groupe nominal. Band 3:L'orthographe. Esch-sur-Alzette, éditions Schortgen, 2005 et 2006 SCHANEN, François / ZIMMER, Jacqui, Lëtzebuergesch Grammaire luxembourgeoise. En un volume. Esch-sur-Alzette, éditions Schortgen, 2012. In Luxembourgish SCHANEN, François, Lëtzebuergesch Sproocherubriken. Esch-sur-Alzette, éditions Schortgen, 2013. Meyer, Antoine, E' Schrek ob de' lezeburger Parnassus, Lezeburg (Luxembourg), Lamort, 1829 In German BRUCH, Robert, Grundlegung einer Geschichte des Luxemburgischen, Luxembourg, Publications scientifiques et littéraires du Ministère de l'Éducation nationale, 1953, vol. I; Das Luxemburgische im westfränkischen Kreis, Luxembourg, Publications scientifiques et littéraires du Ministère de l'Éducation nationale, 1954, vol. II MOULIN, Claudine and Nübling, Damaris (publisher): Perspektiven einer linguistischen Luxemburgistik. Studien zu Diachronie und Synchronie., Universitätsverlag Winter, Heidelberg, 2006. This book has been published with the support of the Fonds National de la Recherche BERG, Guy, Mir wëlle bleiwe wat mir sin: Soziolinguistische und sprachtypologische Betrachtungen zur luxemburgischen Mehrsprachigkeit., Tübingen, 1993 (Reihe Germanistische Linguistik 140). (phrasebook) REMUS, Joscha, Lëtzebuergesch Wort für Wort. Kauderwelsch Band 104. Bielefeld, Reise Know-How Verlag 1997. WELSCHBILLIG Myriam, SCHANEN François, Jérôme Lulling, Luxdico Deutsch: Luxemburgisch ↔ Deutsches Wörterbuch, Luxemburg (Éditions Schortgen) 2008, Luxdico Deutsch External links Conseil Permanent de la Langue Luxembourgeoise Spellcheckers and dictionaries Spellcheckers for Luxembourgish: Spellchecker.lu, Spellchecker.lu - Richteg Lëtzebuergesch schreiwen Luxdico online dictionary (24.000 words) Lëtzebuerger Online Dictionnaire (Luxembourgish Online Dictionary) with German, French and Portuguese translations created by the CPLL dico.lu – Dictionnaire Luxembourgeois//Français Luxembourgish Dictionary with pronunciation, translation to and from English, French, German, Portuguese, Spanish, Italian Luxogramm – Information system for the Luxembourgish grammar (University of Luxembourg, LU) Germanic languages Central German languages German dialects Languages of Belgium Languages of France Languages of Luxembourg National symbols of Luxembourg Verb-second languages Walloon culture Liège (province) Luxembourg (Belgium) Arlon St. Vith	[ 0.22671367228031158, 0.21013523638248444, 0.21496054530143738, -0.8697757720947266, -0.05737407132983208, 0.6273254752159119, 0.01001663412898779, 0.3449520170688629, -0.6394566893577576, -0.08390533924102783, -0.009796136058866978, 0.561741054058075, -0.19814471900463104, 0.06676133722066...
18292	https://en.wikipedia.org/wiki/Lev%20Kuleshov	Lev Kuleshov	Lev Vladimirovich Kuleshov (; – 29 March 1970) was a Russian and Soviet filmmaker and film theorist, one of the founders of the world's first film school, the Moscow Film School. He was given the title People's Artist of the RSFSR in 1969. He was intimately involved in development of the style of film making known as Soviet montage, especially its psychological underpinning, including the use of editing and the cut to emotionally influence the audience, a principle known as the Kuleshov effect. He also developed the theory of creative geography, which is the use of the action around a cut to connect otherwise disparate settings into a cohesive narrative. Life and career Lev Kuleshov was born in 1899 into an intellectual Russian family. His father Vladimir Sergeevich Kuleshov was of noble heritage; he studied art in the Moscow School of Painting, Sculpture and Architecture, despite his own father's disapproval. He then married a village schoolteacher Pelagia Alexandrovna Shubina who was raised in an orphanage, which only led to more confrontation. They gave birth to two sons: Boris and Lev. At the time Lev Kuleshov was born, the family became financially broke, lost their estate and moved to Tambov, living a modest life. In 1911 Vladimir Kuleshov died; three years later Lev and his mother moved to Moscow where his elder brother was studying and working as an engineer. Lev Kuleshov decided to follow the steps of his father and entered the Moscow School of Painting, although he didn't finish it. In 1916 he applied to work at the film company led by Aleksandr Khanzhonkov. He produced scenery for Yevgeni Bauer's pictures, such as The King of Paris, For Happiness and others. With time Kuleshov became more interested in film theory. He co-directed his first movie Twilight in 1917. His next film was released under the Soviet patronage. During 1918–1920 he covered the Russian Civil War with a documentary crew. In 1919 he headed the first Soviet film courses at the National Film School. Kuleshov may well be the very first film theorist as he was a leader in the Soviet montage theory – developing his theories of editing before those of Sergei Eisenstein (briefly a student of Kuleshov). He contributed the article "Kinematografichesky naturshchik" to the first issue of Zrelishcha in 1922. Among his other notable students were Vsevolod Pudovkin, Boris Barnet, Mikhail Romm, Sergey Komarov, Porfiri Podobed, Vladimir Fogel and Aleksandra Khokhlova who became his wife. For Kuleshov, the essence of the cinema was editing, the juxtaposition of one shot with another. To illustrate this principle, he created what has come to be known as the Kuleshov Effect. In this now-famous editing exercise, shots of an actor were intercut with various meaningful images (a casket, a bowl of soup, etc.) in order to show how editing changes viewers' interpretations of images. Another one of his famous inventions was creative geography, also known as artificial landscape. Those techniques were described in his book The Basics of Film Direction (1941) which was later translated into many languages. In addition to his theoretical and teaching work, Kuleshov directed a number of feature-length films. Among his most notable works are an action-comedy The Extraordinary Adventures of Mr. West in the Land of the Bolsheviks (1924), a psychological drama By the Law (1926) adapted from the short story by Jack London and a biographical drama The Great Consoler (1933) based on O. Henry's life and works. In 1934 and 1935 Kuleshov went to Tajikistan to direct there Dokhunda, a movie based on the novel by Tajik national poet Sadriddin Ayni, but the project was regarded with suspicion by the authorities as possibly exciting Tajik nationalism, and stopped. No footage survives. After directing his last film in 1943, Kuleshov served as an artistic director and an academic rector at VGIK where he worked for the next 25 years. He was a member of the jury at the 27th Venice International Film Festival, as well as a special guest during other international film festivals. Lev Kuleshov died in Moscow in 1970. He was buried at the Novodevichy Cemetery. He was survived by his wife Aleksandra Khokhlova (1897–1985) – an actress, film director and educator, granddaughter of Pavel Tretyakov and Sergey Botkin – and Aleksandra's son Sergei from her first marriage. Awards and honours People's Artist of the RSFSR, 1969. Order of Lenin Order of the Red Banner of Labour Filmography References Further reading Kuleshov, Lev. Kuleshov on Film, translated and edited, with an introduction by Ronald Levaco. Berkeley: University of California Press, 1974. Kuleshov, L.V. Kuleshov on Film: Writings. Berkeley, CA: University of California Press, 1974. Kuleshov, L. V., and E. S. Khokhlova. Fifty Years in Films: Selected Works. Moscow: Raduga Publishers, 1987. Drubek, Natascha. Russisches Licht. Von der Ikone zum frühen sowjetischen Kino, Wien – Köln – Weimar: Böhlau 2012. Izvolov, Nikolai and Natascha Drubek-Meyer. “Annotations for the Hyperkino Edition of Lev Kulershov’s Engineer Prite’s Project (1918), Academia Series, RUSCICO 2010.” Studies in Russian & Soviet Cinema. 4.1 (2010): 65-93. Kepley, Jr., Vance. “Mr. Kuleshov in the Land of the Modernists.” The Red Screen: Politics, Society, Art in Soviet Cinema. Ed. Anna Lawton. London; New York: Routledge, 1992. 132-47. Norris, Stephen. Lev Kuleshov (Dir.), “Proekt Inzhenera Praita” (“Engineer Prite’s Project”); “Velikii uteshitel’ (O. Genri v tiur’me)” (“The Great Consoler (O’Henry in Prison”) (DVD Review 2011). https://artmargins.com/lev-kuleshov-dir-qproekt-inzhenera-praitaq-qengineer-prites-projectq-qvelikii-uteshitel-o-genri-v-tiurmeq-qthe-great-consoler-ohenry-in-prisonq-dvd-review/ Olenina, Ana. “Lev Kuleshov’s Retrospective in Bologna, 2008: An Interview with Ekaterina Khokhlova.” Art Margins Online. (Oct 2008). Yampolsky, Mikhail. “Kuleshov’s Experiments and the New Anthropology of the Actor.” Inside the Film factory: New Approaches to Russian and Soviet Filmmaking. Eds. Richard Taylor and Ian Christie. London, UK: Routledge, 1994, 31-50. External links An interview with Lev Kuleshov's grand-daughter, the film scholar Ekaterina Khokhlova. By Ana Olenina. 1899 births 1970 deaths People from Tambov People from Tambov Governorate Communist Party of the Soviet Union members Soviet film directors Soviet screenwriters Male screenwriters Film theorists Russian inventors People's Artists of the RSFSR Recipients of the Order of Lenin Burials at Novodevichy Cemetery	[ 0.5796625018119812, 0.40392571687698364, -0.39451295137405396, -0.0009912612149491906, 0.24754682183265686, 0.5710870027542114, -0.1256100982427597, -0.6600371599197388, 0.12223765254020691, 0.2474728226661682, -0.8170344829559326, 0.24802584946155548, -0.17774276435375214, 0.7169041037559...
18295	https://en.wikipedia.org/wiki/Legacy%20system	Legacy system	In computing, a legacy system is an old method, technology, computer system, or application program, "of, relating to, or being a previous or outdated computer system," yet still in use. Often referencing a system as "legacy" means that it paved the way for the standards that would follow it. This can also imply that the system is out of date or in need of replacement. Legacy code is old computer source code. It could simply refer to an organization's existing code base which has been written over many years, or it could imply a codebase that is in some respect obsolete or supporting something obsolete. Long-lived code is susceptible to software rot, where changes to the runtime environment, or surrounding software or hardware may require maintenance or emulation of some kind to keep working. Legacy code may be present to support legacy hardware, a separate legacy system, or a legacy customer using an old feature or software version. While the term usually refers to source code, it can also apply to executable code that no longer runs on a later version of a system, or requires a compatibility layer to do so. An example would be a classic Macintosh application which will not run natively on macOS, but runs inside the Classic environment, or a Win16 application running on Windows XP using the Windows on Windows feature in XP. An example of legacy hardware are legacy ports like PS/2 and VGA ports, and CPUs with older, incompatible instruction sets (with e.g. newer operating systems). Examples in legacy software include legacy file formats like .swf for Adobe Shockwave or .123 for Lotus 1-2-3, and text files encoded with legacy character encodings like EBCDIC. Overview The first use of the term legacy to describe computer systems probably occurred in the 1960s. By the 1980s it was commonly used to refer to existing computer systems to distinguish them from the design and implementation of new systems. Legacy was often heard during a conversion process, for example, when moving data from the legacy system to a new database. While this term may indicate that some engineers may feel that a system is out of date, a legacy system can continue to be used for a variety of reasons. It may simply be that the system still provides for the users' needs. In addition, the decision to keep an old system may be influenced by economic reasons such as return on investment challenges or vendor lock-in, the inherent challenges of change management, or a variety of other reasons other than functionality. Backward compatibility (such as the ability of newer systems to handle legacy file formats and character encodings) is a goal that software developers often include in their work. Even if it is no longer used, a legacy system may continue to impact the organization due to its historical role. Historic data may not have been converted into the new system format and may exist within the new system with the use of a customized schema crosswalk, or may exist only in a data warehouse. In either case, the effect on business intelligence and operational reporting can be significant. A legacy system may include procedures or terminology which are no longer relevant in the current context, and may hinder or confuse understanding of the methods or technologies used. Organizations can have compelling reasons for keeping a legacy system, such as: The system works satisfactorily, and the owner sees no reason to change it. The costs of redesigning or replacing the system are prohibitive because it is large, monolithic, and/or complex. Retraining on a new system would be costly in lost time and money, compared to the anticipated appreciable benefits of replacing it (which may be zero). The system requires near-constant availability, so it cannot be taken out of service, and the cost of designing a new system with a similar availability level is high. Examples include systems to handle customers' accounts in banks, computer reservations systems, air traffic control, energy distribution (power grids), nuclear power plants, military defense installations, and systems such as the TOPS database. The way that the system works is not well understood. Such a situation can occur when the designers of the system have left the organization, and the system has either not been fully documented or documentation has been lost. The user expects that the system can easily be replaced when this becomes necessary. Newer systems perform undesirable (especially for individual or non-institutional users) secondary functions such as a) tracking and reporting of user activity and/or b) automatic updating that creates "back-door" security vulnerabilities and leaves end users dependent on the good faith and honesty of the vendor providing the updates. This problem is especially acute when these secondary functions of a newer system cannot be disabled. Problems posed by legacy computing Legacy systems are considered to be potentially problematic by some software engineers for several reasons. If legacy software runs on only antiquated hardware, the cost of maintaining the system may eventually outweigh the cost of replacing both the software and hardware unless some form of emulation or backward compatibility allows the software to run on new hardware. These systems can be hard to maintain, improve, and expand because there is a general lack of understanding of the system; the staff who were experts on it have retired or forgotten what they knew about it, and staff who entered the field after it became "legacy" never learned about it in the first place. This can be worsened by lack or loss of documentation. Comair airline company fired its CEO in 2004 due to the failure of an antiquated legacy crew scheduling system that ran into a limitation not known to anyone in the company. Legacy systems may have vulnerabilities in older operating systems or applications due to lack of security patches being available or applied. There can also be production configurations that cause security problems. These issues can put the legacy system at risk of being compromised by attackers or knowledgeable insiders. Integration with newer systems may also be difficult because new software may use completely different technologies. Integration across technology is quite common in computing, but integration between newer technologies and substantially older ones is not common. There may simply not be sufficient demand for integration technology to be developed. Some of this "glue" code is occasionally developed by vendors and enthusiasts of particular legacy technologies. Budgetary constraints often lead corporations to not address the need of replacement or migration of a legacy system. However, companies often don't consider the increasing supportability costs (people, software and hardware, all mentioned above) and do not take into consideration the enormous loss of capability or business continuity if the legacy system were to fail. Once these considerations are well understood, then based on the proven ROI of a new, more secure, updated technology stack platform is not as costly as the alternative—and the budget is found. Due to the fact that most legacy programmers are entering retirement age and the number of young engineers replacing them is very small, there is an alarming shortage of available workforce. This in turn results in difficulty in maintaining legacy systems, as well as an increase in costs of procuring experienced programmers. Improvements on legacy software systems Where it is impossible to replace legacy systems through the practice of application retirement, it is still possible to enhance (or "re-face") them. Most development often goes into adding new interfaces to a legacy system. The most prominent technique is to provide a Web-based interface to a terminal-based mainframe application. This may reduce staff productivity due to slower response times and slower mouse-based operator actions, yet it is often seen as an "upgrade", because the interface style is familiar to unskilled users and is easy for them to use. John McCormick discusses such strategies that involve middleware. Printing improvements are problematic because legacy software systems often add no formatting instructions, or they use protocols that are not usable in modern PC/Windows printers. A print server can be used to intercept the data and translate it to a more modern code. Rich Text Format (RTF) or PostScript documents may be created in the legacy application and then interpreted at a PC before being printed. Biometric security measures are difficult to implement on legacy systems. A workable solution is to use a Telnet or HTTP proxy server to sit between users and the mainframe to implement secure access to the legacy application. The change being undertaken in some organizations is to switch to automated business process (ABP) software which generates complete systems. These systems can then interface to the organizations' legacy systems and use them as data repositories. This approach can provide a number of significant benefits: the users are insulated from the inefficiencies of their legacy systems, and the changes can be incorporated quickly and easily in the ABP software. Model-driven reverse and forward engineering approaches can be also used for the improvement of legacy software. NASA example Andreas Hein, from the Technical University of Munich, researched the use of legacy systems in space exploration. According to Hein, legacy systems are attractive for reuse if an organization has the capabilities for verification, validation, testing, and operational history. These capabilities must be integrated into various software life cycle phases such as development, implementation, usage, or maintenance. For software systems, the capability to use and maintain the system are crucial. Otherwise the system will become less and less understandable and maintainable. According to Hein, verification, validation, testing, and operational history increases the confidence in a system's reliability and quality. However, accumulating this history is often expensive. NASA's now retired Space Shuttle program used a large amount of 1970s-era technology. Replacement was cost-prohibitive because of the expensive requirement for flight certification. The original hardware completed the expensive integration and certification requirement for flight, but any new equipment would have had to go through that entire process again. This long and detailed process required extensive tests of the new components in their new configurations before a single unit could be used in the Space Shuttle program. Thus any new system that started the certification process becomes a de facto legacy system by the time it is approved for flight. Additionally, the entire Space Shuttle system, including ground and launch vehicle assets, was designed to work together as a closed system. Since the specifications did not change, all of the certified systems and components performed well in the roles for which they were designed. Even before the Shuttle was scheduled to be retired in 2010, NASA found it advantageous to keep using many pieces of 1970s technology rather than to upgrade those systems and recertify the new components. Perspectives on legacy code Some in the software engineering prefer to describe "legacy code" without the connotation of being obsolete. Among the most prevalent neutral conceptions are source code inherited from someone else and source code inherited from an older version of the software. Eli Lopian, CEO of Typemock, has defined it as "code that developers are afraid to change". Michael Feathers introduced a definition of legacy code as code without tests, which reflects the perspective of legacy code being difficult to work with in part due to a lack of automated regression tests. He also defined characterization tests to start putting legacy code under test. Ginny Hendry characterized creation of code as a challenge to current coders to create code that is "like other legacies in our lives—like the antiques, heirlooms, and stories that are cherished and lovingly passed down from one generation to the next. What if legacy code was something we took pride in?". Additional uses of the term Legacy in computing The term legacy support is often used in conjunction with legacy systems. The term may refer to a feature of modern software. For example, Operating systems with "legacy support" can detect and use older hardware. The term may also be used to refer to a business function; e.g. a software or hardware vendor that is supporting, or providing software maintenance, for older products. A "legacy" product may be a product that is no longer sold, has lost substantial market share, or is a version of a product that is not current. A legacy product may have some advantage over a modern product making it appealing for customers to keep it around. A product is only truly "obsolete" if it has an advantage to nobody—if no person making a rational decision would choose to acquire it new. The term "legacy mode" often refers specifically to backward compatibility. A software product that is capable of performing as though it were a previous version of itself, is said to be "running in legacy mode." This kind of feature is common in operating systems and internet browsers, where many applications depend on these underlying components. The computer mainframe era saw many applications running in legacy mode. In the modern business computing environment, n-tier, or 3-tier architectures are more difficult to place into legacy mode as they include many components making up a single system. Virtualization technology is a recent innovation allowing legacy systems to continue to operate on modern hardware by running older operating systems and browsers on a software system that emulates legacy hardware. Brownfield architecture Programmers have borrowed the term brownfield from the construction industry, where previously developed land (often polluted and abandoned) is described as brownfield. Brownfield architecture is a type of software or network architecture that incorporates legacy systems. Brownfield deployment is an upgrade or addition to an existing software or network architecture that retains legacy components. Alternative view There is an alternate favorable opinion—growing since the end of the Dotcom bubble in 1999—that legacy systems are simply computer systems in working use: IT analysts estimate that the cost of replacing business logic is about five times that of reuse, even discounting the risk of system failures and security breaches. Ideally, businesses would never have to rewrite most core business logic: debits = credits is a perennial requirement. The IT industry is responding with "legacy modernization" and "legacy transformation": refurbishing existing business logic with new user interfaces, sometimes using screen scraping and service-enabled access through web services. These techniques allow organizations to understand their existing code assets (using discovery tools), provide new user and application interfaces to existing code, improve workflow, contain costs, minimize risk, and enjoy classic qualities of service (near 100% uptime, security, scalability, etc.). This trend also invites reflection on what makes legacy systems so durable. Technologists are relearning the importance of sound architecture from the start, to avoid costly and risky rewrites. The most common legacy systems tend to be those which embraced well-known IT architectural principles, with careful planning and strict methodology during implementation. Poorly designed systems often don't last, both because they wear out and because their inherent faults invite replacement. Thus, many organizations are rediscovering the value of both their legacy systems and the theoretical underpinnings of those systems. See also Application retirement Software rot Data migration Deprecation Digital dark age Legacy encoding Legacy-free PC Legacy port Software archaeology Software brittleness Software entropy Stovepipe system References Further reading A.M. Hein, How to Assess Heritage Systems in the Early Phases? SECESA 2014, 08-10 October 2014, University of Stuttgart Germany "Tips and Tricks for Legacy Hardware" by Danny Budzinski, Control Design Magazine, January 2011 "Comair's Christmas Disaster: Bound To Fail" by Stephanie Overby, CIO Magazine, May 1, 2005 "The Failure of the Digital Computer" by Adam N. Rosenberg "The Danger of Legacy Systems" by Steve R. Smith, May 3, 2011. External links System Technological change	[ 0.22678667306900024, 0.17378182709217072, -0.009419833309948444, 0.16923192143440247, 0.7399401664733887, 0.09102741628885269, -0.0080219442024827, 0.35389402508735657, -0.40448880195617676, -0.4449760615825653, -0.8052695989608765, 0.036366116255521774, 0.08088161051273346, 0.856025755405...

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