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[SOURCE: https://en.wikipedia.org/wiki/Eastern_Agricultural_Complex] | [TOKENS: 2519] |
Contents Eastern Agricultural Complex The Eastern Agricultural Complex in the woodlands of eastern North America was one of about 10 independent centers of plant domestication in the pre-historic world. Incipient agriculture dates back to about 5300 BCE. By about 1800 BCE the Native Americans of the woodlands were cultivating several species of food plants, thus beginning a transition from a hunter-gatherer economy to agriculture. After 200 BCE when maize (Zea mays, commonly called "corn") from Mexico was introduced to the Eastern Woodlands, the Native Americans of the eastern United States and adjacent Canada slowly changed from growing locally cultivated plant species to a maize-based agricultural economy. The cultivation of local indigenous plants other than squash and sunflower declined and was eventually abandoned. The formerly domesticated plants returned to their wild forms. The first four plants known to have been domesticated at the Riverton Site in Illinois in 1800 BCE were goosefoot (Chenopodium berlandieri), sunflower (Helianthus annuus var. macrocarpus), marsh elder (Iva annua var. macrocarpa), and squash (Cucurbita pepo ssp. ovifera). Several other species of plants were later domesticated. Origin of name and concept The term Eastern Agricultural Complex (EAC) was popularized by anthropologist Ralph Linton in the 1940s. Linton suggested that the Eastern Woodland tribes integrated maize cultivation from Mayans and Aztecs in Mexico into their own pre-existing agricultural subsistence practices. Ethnobotanists Volney H. Jones and Melvin R. Gilmore built upon Ralph Linton's understanding of Eastern Woodland agriculture with their work in cave and bluff dwellings in Kentucky and the Ozark Mountains in Arkansas. George Quimby also popularized the term "Eastern complex" in the 1940s. Authors Guy Gibbons and Kenneth Ames suggested that "indigenous seed crops" is a more appropriate term than "complex". Until the 1970s and 1980s most archaeologists believed that agriculture by Eastern Woodland peoples had been imported from what is now Mexico, along with the trio of subtropical crops: maize (corn), beans, and squash. What became accepted by the 21st century is that agriculture in the Eastern Woodlands preceded the import of crops from Mexico and that the Eastern Woodlands were one of about ten cultural regions in the world to become an "independent center of agricultural origin." In the 1970s and 1980s, new archaeological techniques demonstrated that by 1800 BCE the Native Americans of the eastern woodlands had learned to cultivate indigenous crops independently and that indigenous crops formed an important part of their diets. A major element in determining that plants were cultivated rather than being collected in the wild was the larger size of edible seeds and the thinner seed coat of the domesticated plant compared to its wild relative, an attribute of domesticated crops that came about through human selection and manipulation. When cultivation of most indigenous plants ceased in favor of maize agriculture about 900 CE, seed sizes and seed coats of plants reverted to their former uncultivated size and thickness. Cultivated species The earliest cultivated plant in North America is the bottle gourd, remains of which have been excavated at Little Salt Spring, Florida dating to 8000 BCE. Squash (Cucurbita pepo var. ozarkana) is considered to be one of the first domesticated plants in the Eastern Woodlands, having been found in the region about 5000 BCE, though possibly not domesticated in the region until about 1000 BCE. The squash that was originally part of the complex was raised for edible seeds and to produce small containers (gourds), not for the thick flesh that is associated with modern varieties of squash. Cucurbita argyrosperma has been found in the region dated to circa 1300-1500 BCE. C. pepo cultivars crookneck, acorn, and scallop squash appeared later. Other plants of the EAC include The plants are often divided into "oily" or "starchy" categories. Sunflower and sumpweed have edible seeds rich in oil. The seeds of erect knotweed and goosefoot are starches, as are maygrass and little barley, both of which are grasses that yield grains that may be ground to make flour. Development The archaeological record suggests that humans were collecting these plants from the wild by 6000 BCE. In the 1970s, archaeologists noticed differences between seeds found in the remains of pre-Columbus era Native American hearths and houses and those growing in the wild. In a domestic setting, the seeds of some plants were much larger than in the wild, and the seeds were easier to extract from the shells or husks. This was evidence that Indigenous gardeners were selectively breeding the plants to make them more productive and accessible. The region of this early agriculture is in the middle Mississippi valley, from Memphis north to St. Louis and extending about 300 miles east and west of the river, mostly in Missouri, Illinois, Kentucky, and Tennessee. The oldest archaeological site known in the United States in which Native Americans were growing, rather than gathering, food is Phillips Spring in Missouri. At Phillips Spring, dating from 3000 BCE, archaeologists found abundant walnuts, hickory nuts, acorns, grapes, elderberries, ragweed, bottle gourd, and the seeds of Cucurbita pepo, a gourd with edible seeds that is the ancestor of pumpkins and most squashes. The seeds found at Phillips Spring were larger than those of wild C. pepo. The cause of this distinction is inferred to be human cultivation. Humans were selecting, planting, and tending seeds from plants that produced larger and tastier seeds. Ultimately, they would manipulate C. pepo to produce edible flesh. By 1800 BCE, Native Americans were cultivating several different plants. The Riverton Site in the Wabash River valley of Illinois, near the present day village of Palestine, is one of the best known early sites of cultivation. Ten house sites have been discovered at Riverton, indicating a population of 50 to 100 people in the community. Among the hearths and storage pits associated with the houses, archaeologists found a large number of plant remains, including a large number of seeds of chenopods (goosefoot or lamb's quarters) which are likely cultivated plants. Some of the chenopod (Chenopodium berlandieri) seeds had husks only a third as thick as those of wild seeds. Riverton farmers had bred them selectively to produce a seed easier to access than wild varieties of the same plant. The wild food guru of the 1960s, Euell Gibbons, gathered and ate chenopods. "In rich soil," he said, "lamb's quarters will grow four or five feet high if not disturbed, becoming much branched. It bears a heavy crop of tiny seeds in panicles at the end of every branch. In early winter, when the panicles are dry, it is quite easy to gather these seeds in considerable quantity. Just hold a pail under the branches and strip them off. Rub the husks between the hands to separate the seed and chaff, then winnow out the trash. I have collected several quarts of seed in an hour, using this method. The seeds are quite fine, being smaller than mustard seeds, and a dull blackish-brown color....I find it pretty good food for humans." Another plant species at Riverton that can confidently be identified as domesticated was sunflower (Helianthus annuus). This is based on the larger size of the seed in the domesticated than in the wild varieties. Remains of plants that were used, but may or may not have been domesticated at Riverton, include bottle gourd (Lagenaria siceraria), squash (C. pepo), wild barley (Hordeum pusillum) and marsh elder (Iva annua). Domestication Some of the species cultivated by Native Americans for food are today considered undesirable weeds. Another name for marshelder is sumpweed; chenopods are derisively called pigweed, although one South American species with a more attractive name, quinoa, is a health food store favorite. Many plants considered weeds are the colonizers of disturbed soil, the first fast-growing weeds to spring up when a natural or man-made event, such as a fire, leaves a bare patch of soil. The process of domestication of wild plants cannot be described with any precision. However, Bruce D. Smith and other scholars have pointed out that three of the domesticates (chenopods, I. annua, and C. pepo) were plants that thrived in disturbed soils in river valleys. In the aftermath of a flood, in which most of the old vegetation is killed by the high waters and bare patches of new, often very fertile, soil were created, these pioneer plants sprang up like magic, often growing in almost pure stands, but usually disappearing after a single season, as other vegetation pushed them out until the next flood. Native Americans learned early that the seeds of these three species were edible and easily harvested in quantity because they grew in dense stands. C. pepo was important also because the gourd could be made into a lightweight container that was useful to a seminomadic band. Chenopods have edible leaves, related to spinach and chard, that may have also been gathered and eaten by Native Americans. Chenopod seeds are starchy; marsh elder has a highly nutritious oily seed similar to sunflower seeds. In gathering the seeds some were undoubtedly dropped in the sunny environment and disturbed soil of a settlement, and those seeds sprouted and thrived. Over time the seeds were sown and the ground was cleared of any competitive vegetation. The seeds which germinated quickest (i.e. thinner seed coats) and the plants which grew fastest were the most likely to be tended, harvested, and replanted. Through a process of unconscious selection and, later, conscious selection, the domesticated weeds became more productive. The seeds of some species became substantially larger and/or their seed coats were less thick compared to the wild plants. For example, the seed coats of domesticated chenopodium is less than 20 microns thick; the wild chenopodium of the same species is 40 to 60 microns thick. Conversely, when Native Americans quit growing these plants, as they did later, their seeds reverted within a few years to the thickness they had been in the wild. By about 500 BCE, seeds produced by six domesticated plants were an important part of the diet of Native Americans in the middle Mississippi River valley of the Eastern Woodlands region. Introduction of maize The local indigenous crops were replaced slowly by other more productive crops developed by the Mesoamericans in what is now called Mexico: maize, beans and additional varieties of squash. Maize, or corn, was a relative latecomer to the Eastern Woodlands Cultures. The oldest known evidence of maize in what is now known as Mexico dates to 6700 BCE. The oldest evidence of maize cultivation north of the Rio Grande in use is by about 2100 BCE at several locations in what later became Arizona and New Mexico. Maize was first grown by Eastern Woodlands Cultures by around 200 BCE, and highly productive localized varieties became widely used around 900 CE. The spread was so slow because the seeds and knowledge of techniques for tending them had to cross inhospitable deserts and mountains, and more productive varieties of maize had to be developed to compete with local indigenous crops and to suit the cooler climates and shorter growing seasons of the northern regions. Maize does not flower under the long day conditions of summer north of tropical Mexico, requiring genetic adaptation. Maize was first grown as a supplement to existing local indigenous agricultural plants, but gradually came to dominate as its yields increased. Ultimately, the EAC was thoroughly replaced by maize-based agriculture. Most EAC plants are no longer cultivated, and some of them (such as little barley) are regarded as pests by modern farmers. See also Notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Special:EditPage/Template:Comedy_footer] | [TOKENS: 1447] |
Editing Template:Comedy footer Copy and paste: – — ° ′ ″ ≈ ≠ ≤ ≥ ± − × ÷ ← → · § Sign your posts on talk pages: ~~~~ Cite your sources: <ref></ref> {{}} {{{}}} | [] [[]] [[Category:]] #REDIRECT [[]] <s></s> <sup></sup> <sub></sub> <code></code> <pre></pre> <blockquote></blockquote> <ref></ref> <ref name="" /> {{Reflist}} <references /> <includeonly></includeonly> <noinclude></noinclude> {{DEFAULTSORT:}} <nowiki></nowiki> <!-- --> <span class="plainlinks"></span> Symbols: ~ | ¡ ¿ † ‡ ↔ ↑ ↓ • ¶ # ∞ ‹› «» ¤ ₳ ฿ ₵ ¢ ₡ ₢ $ ₫ ₯ € ₠ ₣ ƒ ₴ ₭ ₤ ℳ ₥ ₦ ₧ ₰ £ ៛ ₨ ₪ ৳ ₮ ₩ ¥ ♠ ♣ ♥ ♦ 𝄫 ♭ ♮ ♯ 𝄪 © ¼ ½ ¾ Latin: A a Á á À à  â Ä ä Ǎ ǎ Ă ă Ā ā à ã Å å Ą ą Æ æ Ǣ ǣ B b C c Ć ć Ċ ċ Ĉ ĉ Č č Ç ç D d Ď ď Đ đ Ḍ ḍ Ð ð E e É é È è Ė ė Ê ê Ë ë Ě ě Ĕ ĕ Ē ē Ẽ ẽ Ę ę Ẹ ẹ Ɛ ɛ Ǝ ǝ Ə ə F f G g Ġ ġ Ĝ ĝ Ğ ğ Ģ ģ H h Ĥ ĥ Ħ ħ Ḥ ḥ I i İ ı Í í Ì ì Î î Ï ï Ǐ ǐ Ĭ ĭ Ī ī Ĩ ĩ Į į Ị ị J j Ĵ ĵ K k Ķ ķ L l Ĺ ĺ Ŀ ŀ Ľ ľ Ļ ļ Ł ł Ḷ ḷ Ḹ ḹ M m Ṃ ṃ N n Ń ń Ň ň Ñ ñ Ņ ņ Ṇ ṇ Ŋ ŋ O o Ó ó Ò ò Ô ô Ö ö Ǒ ǒ Ŏ ŏ Ō ō Õ õ Ǫ ǫ Ọ ọ Ő ő Ø ø Œ œ Ɔ ɔ P p Q q R r Ŕ ŕ Ř ř Ŗ ŗ Ṛ ṛ Ṝ ṝ S s Ś ś Ŝ ŝ Š š Ş ş Ș ș Ṣ ṣ ß T t Ť ť Ţ ţ Ț ț Ṭ ṭ Þ þ U u Ú ú Ù ù Û û Ü ü Ǔ ǔ Ŭ ŭ Ū ū Ũ ũ Ů ů Ų ų Ụ ụ Ű ű Ǘ ǘ Ǜ ǜ Ǚ ǚ Ǖ ǖ V v W w Ŵ ŵ X x Y y Ý ý Ŷ ŷ Ÿ ÿ Ỹ ỹ Ȳ ȳ Z z Ź ź Ż ż Ž ž ß Ð ð Þ þ Ŋ ŋ Ə ə Greek: Ά ά Έ έ Ή ή Ί ί Ό ό Ύ ύ Ώ ώ Α α Β β Γ γ Δ δ Ε ε Ζ ζ Η η Θ θ Ι ι Κ κ Λ λ Μ μ Ν ν Ξ ξ Ο ο Π π Ρ ρ Σ σ ς Τ τ Υ υ Φ φ Χ χ Ψ ψ Ω ω {{Polytonic|}} Cyrillic: А а Б б В в Г г Ґ ґ Ѓ ѓ Д д Ђ ђ Е е Ё ё Є є Ж ж З з Ѕ ѕ И и І і Ї ї Й й Ј ј К к Ќ ќ Л л Љ љ М м Н н Њ њ О о П п Р р С с Т т Ћ ћ У у Ў ў Ф ф Х х Ц ц Ч ч Џ џ Ш ш Щ щ Ъ ъ Ы ы Ь ь Э э Ю ю Я я ́ IPA: t̪ d̪ ʈ ɖ ɟ ɡ ɢ ʡ ʔ ɸ β θ ð ʃ ʒ ɕ ʑ ʂ ʐ ç ʝ ɣ χ ʁ ħ ʕ ʜ ʢ ɦ ɱ ɳ ɲ ŋ ɴ ʋ ɹ ɻ ɰ ʙ ⱱ ʀ ɾ ɽ ɫ ɬ ɮ ɺ ɭ ʎ ʟ ɥ ʍ ɧ ʼ ɓ ɗ ʄ ɠ ʛ ʘ ǀ ǃ ǂ ǁ ɨ ʉ ɯ ɪ ʏ ʊ ø ɘ ɵ ɤ ə ɚ ɛ œ ɜ ɝ ɞ ʌ ɔ æ ɐ ɶ ɑ ɒ ʰ ʱ ʷ ʲ ˠ ˤ ⁿ ˡ ˈ ˌ ː ˑ ̪ {{IPA|}} Wikidata entities used in this page Pages transcluded onto the current version of this page (help): |
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[SOURCE: https://en.wikipedia.org/wiki/Theory_of_computation] | [TOKENS: 1428] |
Contents Theory of computation In theoretical computer science and mathematics, the theory of computation is the branch that deals with what problems can be solved on a model of computation using an algorithm, how efficiently they can be solved and to what degree (e.g., approximate solutions versus precise ones). The field is divided into three major branches: automata theory and formal languages, computability theory, and computational complexity theory, which are linked by the question: "What are the fundamental capabilities and limitations of computers?". In order to perform a rigorous study of computation, computer scientists work with a mathematical abstraction of computers called a model of computation. There are several models in use, but the most commonly examined is the Turing machine. Computer scientists study the Turing machine because it is simple to formulate, can be analyzed and used to prove results, and because it represents what many consider the most powerful possible "reasonable" model of computation (see Church–Turing thesis). It might seem that the potentially infinite memory capacity is an unrealizable attribute, but any decidable problem solved by a Turing machine will always require only a finite amount of memory. So in principle, any problem that can be solved (decided) by a Turing machine can be solved by a computer that has a finite amount of memory. History The theory of computation can be considered the creation of models of all kinds in the field of computer science. Therefore, mathematics and logic are used. In the last century, it separated from mathematics and became an independent academic discipline with its own conferences such as FOCS in 1960 and STOC in 1969, and its own awards such as the IMU Abacus Medal (established in 1981 as the Rolf Nevanlinna Prize), the Gödel Prize, established in 1993, and the Knuth Prize, established in 1996. Some pioneers of the theory of computation were Ramon Llull, Alonzo Church, Kurt Gödel, Alan Turing, Stephen Kleene, Rózsa Péter, John von Neumann and Claude Shannon. Branches Automata theory is the study of abstract machines (or more appropriately, abstract 'mathematical' machines or systems) and the computational problems that can be solved using these machines. These abstract machines are called automata. Automata comes from the Greek word (Αυτόματα) which means that something is doing something by itself. Automata theory is also closely related to formal language theory, as the automata are often classified by the class of formal languages they are able to recognize. An automaton can be a finite representation of a formal language that may be an infinite set. Automata are used as theoretical models for computing machines, and are used for proofs about computability. Formal language theory is a branch of mathematics concerned with describing languages as a set of operations over an alphabet. It is closely linked with automata theory, as automata are used to generate and recognize formal languages. There are several classes of formal languages, each allowing more complex language specification than the one before it, i.e. Chomsky hierarchy, and each corresponding to a class of automata which recognizes it. Because automata are used as models for computation, formal languages are the preferred mode of specification for any problem that must be computed. Computability theory deals primarily with the question of the extent to which a problem is solvable on a computer. The statement that the halting problem cannot be solved by a Turing machine is one of the most important results in computability theory, as it is an example of a concrete problem that is both easy to formulate and impossible to solve using a Turing machine. Much of computability theory builds on the halting problem result. Another important step in computability theory was Rice's theorem, which states that for all non-trivial properties of partial functions, it is undecidable whether a Turing machine computes a partial function with that property. Computability theory is closely related to the branch of mathematical logic called recursion theory, which removes the restriction of studying only models of computation which are reducible to the Turing model. Many mathematicians and computational theorists who study recursion theory will refer to it as computability theory. Computational complexity theory considers not only whether a problem can be solved at all on a computer, but also how efficiently the problem can be solved. Two major aspects are considered: time complexity and space complexity, which are respectively how many steps it takes to perform a computation, and how much memory is required to perform that computation. In order to analyze how much time and space a given algorithm requires, computer scientists express the time or space required to solve the problem as a function of the size of the input problem. For example, finding a particular number in a long list of numbers becomes harder as the list of numbers grows larger. If we say there are n numbers in the list, then if the list is not sorted or indexed in any way we may have to look at every number in order to find the number we're seeking. We thus say that in order to solve this problem, the computer needs to perform a number of steps that grow linearly in the size of the problem. To simplify this problem, computer scientists have adopted big O notation, which allows functions to be compared in a way that ensures that particular aspects of a machine's construction do not need to be considered, but rather only the asymptotic behavior as problems become large. So in our previous example, we might say that the problem requires O ( n ) {\displaystyle O(n)} steps to solve. Perhaps the most important open problem in all of computer science is the question of whether a certain broad class of problems denoted NP can be solved efficiently. This is discussed further at Complexity classes P and NP, and P versus NP problem is one of the seven Millennium Prize Problems stated by the Clay Mathematics Institute in 2000. The Official Problem Description was given by Turing Award winner Stephen Cook. Models of computation Aside from a Turing machine, other equivalent (see Church–Turing thesis) models of computation are in use. In addition to the general computational models, some simpler computational models are useful for special, restricted applications. Regular expressions, for example, specify string patterns in many contexts, from office productivity software to programming languages. Another formalism mathematically equivalent to regular expressions, finite automata are used in circuit design and in some kinds of problem-solving. Context-free grammars specify programming language syntax. Non-deterministic pushdown automata are another formalism equivalent to context-free grammars. Primitive recursive functions are a defined subclass of the recursive functions. Different models of computation have the ability to do different tasks. One way to measure the power of a computational model is to study the class of formal languages that the model can generate; in such a way to the Chomsky hierarchy of languages is obtained. References "central areas of the theory of computation: automata, computability, and complexity." Further reading (There are many textbooks in this area; this list is by necessity incomplete.) External links |
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[SOURCE: https://en.wikipedia.org/wiki/Orion_(constellation)#cite_note-kelley11-48] | [TOKENS: 4993] |
Contents Orion (constellation) Orion is a prominent set of stars visible during winter in the northern celestial hemisphere. It is one of the 88 modern constellations; it was among the 48 constellations listed by the 2nd-century AD/CE astronomer Ptolemy. It is named after a hunter in Greek mythology. Orion is most prominent during winter evenings in the Northern Hemisphere, as are five other constellations that have stars in the Winter Hexagon asterism. Orion's two brightest stars, Rigel (β) and Betelgeuse (α), are both among the brightest stars in the night sky; both are supergiants and slightly variable. There are a further six stars brighter than magnitude 3.0, including three making the short straight line of the Orion's Belt asterism. Orion also hosts the radiant of the annual Orionids, the strongest meteor shower associated with Halley's Comet, and the Orion Nebula, one of the brightest nebulae in the sky. Characteristics Orion is bordered by Taurus to the northwest, Eridanus to the southwest, Lepus to the south, Monoceros to the east, and Gemini to the northeast. Covering 594 square degrees, Orion ranks 26th of the 88 constellations in size. The constellation boundaries, as set by Belgian astronomer Eugène Delporte in 1930, are defined by a polygon of 26 sides. In the equatorial coordinate system, the right ascension coordinates of these borders lie between 04h 43.3m and 06h 25.5m , while the declination coordinates are between 22.87° and −10.97°. The constellation's three-letter abbreviation, as adopted by the International Astronomical Union in 1922, is "Ori". Orion is most visible in the evening sky from January to April, winter in the Northern Hemisphere, and summer in the Southern Hemisphere. In the tropics (less than about 8° from the equator), the constellation transits at the zenith. From May to July (summer in the Northern Hemisphere, winter in the Southern Hemisphere), Orion is in the daytime sky and thus invisible at most latitudes. However, for much of Antarctica in the Southern Hemisphere's winter months, the Sun is below the horizon even at midday. Stars (and thus Orion, but only the brightest stars) are then visible at twilight for a few hours around local noon, just in the brightest section of the sky low in the North where the Sun is just below the horizon. At the same time of day at the South Pole itself (Amundsen–Scott South Pole Station), Rigel is only 8° above the horizon, and the Belt sweeps just along it. In the Southern Hemisphere's summer months, when Orion is normally visible in the night sky, the constellation is actually not visible in Antarctica because the Sun does not set at that time of year south of the Antarctic Circle. In countries close to the equator (e.g. Kenya, Indonesia, Colombia, Ecuador), Orion appears overhead in December around midnight and in the February evening sky. Navigational aid Orion is very useful as an aid to locating other stars. By extending the line of the Belt southeastward, Sirius (α CMa) can be found; northwestward, Aldebaran (α Tau). A line eastward across the two shoulders indicates the direction of Procyon (α CMi). A line from Rigel through Betelgeuse points to Castor and Pollux (α Gem and β Gem). Additionally, Rigel is part of the Winter Circle asterism. Sirius and Procyon, which may be located from Orion by following imaginary lines (see map), also are points in both the Winter Triangle and the Circle. Features Orion's seven brightest stars form a distinctive hourglass-shaped asterism, or pattern, in the night sky. Four stars—Rigel, Betelgeuse, Bellatrix, and Saiph—form a large roughly rectangular shape, at the center of which lie the three stars of Orion's Belt—Alnitak, Alnilam, and Mintaka. His head is marked by an additional eighth star called Meissa, which is fairly bright to the observer. Descending from the Belt is a smaller line of three stars, Orion's Sword (the middle of which is in fact not a star but the Orion Nebula), also known as the hunter's sword. Many of the stars are luminous hot blue supergiants, with the stars of the Belt and Sword forming the Orion OB1 association. Standing out by its red hue, Betelgeuse may nevertheless be a runaway member of the same group. Orion's Belt, or The Belt of Orion, is an asterism within the constellation. It consists of three bright stars: Alnitak (Zeta Orionis), Alnilam (Epsilon Orionis), and Mintaka (Delta Orionis). Alnitak is around 800 light-years away from Earth, 100,000 times more luminous than the Sun, and shines with a magnitude of 1.8; much of its radiation is in the ultraviolet range, which the human eye cannot see. Alnilam is approximately 2,000 light-years from Earth, shines with a magnitude of 1.70, and with an ultraviolet light that is 375,000 times more luminous than the Sun. Mintaka is 915 light-years away and shines with a magnitude of 2.21. It is 90,000 times more luminous than the Sun and is a double star: the two orbit each other every 5.73 days. In the Northern Hemisphere, Orion's Belt is best visible in the night sky during the month of January at around 9:00 pm, when it is approximately around the local meridian. Just southwest of Alnitak lies Sigma Orionis, a multiple star system composed of five stars that have a combined apparent magnitude of 3.7 and lying at a distance of 1150 light-years. Southwest of Mintaka lies the quadruple star Eta Orionis. Orion's Sword contains the Orion Nebula, the Messier 43 nebula, Sh 2-279 (also known as the Running Man Nebula), and the stars Theta Orionis, Iota Orionis, and 42 Orionis. Three stars comprise a small triangle that marks the head. The apex is marked by Meissa (Lambda Orionis), a hot blue giant of spectral type O8 III and apparent magnitude 3.54, which lies some 1100 light-years distant. Phi-1 and Phi-2 Orionis make up the base. Also nearby is the young star FU Orionis. Stretching north from Betelgeuse are the stars that make up Orion's club. Mu Orionis marks the elbow, Nu and Xi mark the handle of the club, and Chi1 and Chi2 mark the end of the club. Just east of Chi1 is the Mira-type variable red giant star U Orionis. West from Bellatrix lie six stars all designated Pi Orionis (π1 Ori, π2 Ori, π3 Ori, π4 Ori, π5 Ori, and π6 Ori) which make up Orion's shield. Around 20 October each year, the Orionid meteor shower (Orionids) reaches its peak. Coming from the border with the constellation Gemini, as many as 20 meteors per hour can be seen. The shower's parent body is Halley's Comet. Hanging from Orion's Belt is his sword, consisting of the multiple stars θ1 and θ2 Orionis, called the Trapezium and the Orion Nebula (M42). This is a spectacular object that can be clearly identified with the naked eye as something other than a star. Using binoculars, its clouds of nascent stars, luminous gas, and dust can be observed. The Trapezium cluster has many newborn stars, including several brown dwarfs, all of which are at an approximate distance of 1,500 light-years. Named for the four bright stars that form a trapezoid, it is largely illuminated by the brightest stars, which are only a few hundred thousand years old. Observations by the Chandra X-ray Observatory show both the extreme temperatures of the main stars—up to 60,000 kelvins—and the star forming regions still extant in the surrounding nebula. M78 (NGC 2068) is a nebula in Orion. With an overall magnitude of 8.0, it is significantly dimmer than the Great Orion Nebula that lies to its south; however, it is at approximately the same distance, at 1600 light-years from Earth. It can easily be mistaken for a comet in the eyepiece of a telescope. M78 is associated with the variable star V351 Orionis, whose magnitude changes are visible in very short periods of time. Another fairly bright nebula in Orion is NGC 1999, also close to the Great Orion Nebula. It has an integrated magnitude of 10.5 and is 1500 light-years from Earth. The variable star V380 Orionis is embedded in NGC 1999. Another famous nebula is IC 434, the Horsehead Nebula, near Alnitak (Zeta Orionis). It contains a dark dust cloud whose shape gives the nebula its name. NGC 2174 is an emission nebula located 6400 light-years from Earth. Besides these nebulae, surveying Orion with a small telescope will reveal a wealth of interesting deep-sky objects, including M43, M78, and multiple stars including Iota Orionis and Sigma Orionis. A larger telescope may reveal objects such as the Flame Nebula (NGC 2024), as well as fainter and tighter multiple stars and nebulae. Barnard's Loop can be seen on very dark nights or using long-exposure photography. All of these nebulae are part of the larger Orion molecular cloud complex, which is located approximately 1,500 light-years away and is hundreds of light-years across. Due to its proximity, it is one of the most intense regions of stellar formation visible from Earth. The Orion molecular cloud complex forms the eastern part of an even larger structure, the Orion–Eridanus Superbubble, which is visible in X-rays and in hydrogen emissions. History and mythology The distinctive pattern of Orion is recognized in numerous cultures around the world, and many myths are associated with it. Orion is used as a symbol in the modern world. In Siberia, the Chukchi people see Orion as a hunter; an arrow he has shot is represented by Aldebaran (Alpha Tauri), with the same figure as other Western depictions. In Greek mythology, Orion was a gigantic, supernaturally strong hunter, born to Euryale, a Gorgon, and Poseidon (Neptune), god of the sea. One myth recounts Gaia's rage at Orion, who dared to say that he would kill every animal on Earth. The angry goddess tried to dispatch Orion with a scorpion. This is given as the reason that the constellations of Scorpius and Orion are never in the sky at the same time. However, Ophiuchus, the Serpent Bearer, revived Orion with an antidote. This is said to be the reason that the constellation of Ophiuchus stands midway between the Scorpion and the Hunter in the sky. The constellation is mentioned in Horace's Odes (Ode 3.27.18), Homer's Odyssey (Book 5, line 283) and Iliad, and Virgil's Aeneid (Book 1, line 535). In old Hungarian tradition, Orion is known as "Archer" (Íjász), or "Reaper" (Kaszás). In recently rediscovered myths, he is called Nimrod (Hungarian: Nimród), the greatest hunter, father of the twins Hunor and Magor. The π and o stars (on upper right) form together the reflex bow or the lifted scythe. In other Hungarian traditions, Orion's Belt is known as "Judge's stick" (Bírópálca). In Ireland and Scotland, Orion was called An Bodach, a figure from Irish folklore whose name literally means "the one with a penis [bod]" and was the husband of the Cailleach (hag). In Scandinavian tradition, Orion's Belt was known as "Frigg's Distaff" (friggerock) or "Freyja's distaff". The Finns call Orion's Belt and the stars below it "Väinämöinen's scythe" (Väinämöisen viikate). Another name for the asterism of Alnilam, Alnitak, and Mintaka is "Väinämöinen's Belt" (Väinämöisen vyö) and the stars "hanging" from the Belt as "Kaleva's sword" (Kalevanmiekka). There are claims in popular media that the Adorant from the Geißenklösterle cave, an ivory carving estimated to be 35,000 to 40,000 years old, is the first known depiction of the constellation. Scholars dismiss such interpretations, saying that perceived details such as a belt and sword derive from preexisting features in the grain structure of the ivory. The Babylonian star catalogues of the Late Bronze Age name Orion MULSIPA.ZI.AN.NA,[note 1] "The Heavenly Shepherd" or "True Shepherd of Anu" – Anu being the chief god of the heavenly realms. The Babylonian constellation is sacred to Papshukal and Ninshubur, both minor gods fulfilling the role of "messenger to the gods". Papshukal is closely associated with the figure of a walking bird on Babylonian boundary stones, and on the star map the figure of the Rooster is located below and behind the figure of the True Shepherd—both constellations represent the herald of the gods, in his bird and human forms respectively. In ancient Egypt, the stars of Orion were regarded as a god, called Sah. Because Orion rises before Sirius, the star whose heliacal rising was the basis for the Solar Egyptian calendar, Sah was closely linked with Sopdet, the goddess who personified Sirius. The god Sopdu is said to be the son of Sah and Sopdet. Sah is syncretized with Osiris, while Sopdet is syncretized with Osiris' mythological wife, Isis. In the Pyramid Texts, from the 24th and 23rd centuries BC, Sah is one of many gods whose form the dead pharaoh is said to take in the afterlife. The Armenians identified their legendary patriarch and founder Hayk with Orion. Hayk is also the name of the Orion constellation in the Armenian translation of the Bible. The Bible mentions Orion three times, naming it "Kesil" (כסיל, literally – fool). Though, this name perhaps is etymologically connected with "Kislev", the name for the ninth month of the Hebrew calendar (i.e. November–December), which, in turn, may derive from the Hebrew root K-S-L as in the words "kesel, kisla" (כֵּסֶל, כִּסְלָה, hope, positiveness), i.e. hope for winter rains.: Job 9:9 ("He is the maker of the Bear and Orion"), Job 38:31 ("Can you loosen Orion's belt?"), and Amos 5:8 ("He who made the Pleiades and Orion"). In ancient Aram, the constellation was known as Nephîlā′, the Nephilim are said to be Orion's descendants. In medieval Muslim astronomy, Orion was known as al-jabbar, "the giant". Orion's sixth brightest star, Saiph, is named from the Arabic, saif al-jabbar, meaning "sword of the giant". In China, Orion was one of the 28 lunar mansions Sieu (Xiù) (宿). It is known as Shen (參), literally meaning "three", for the stars of Orion's Belt. The Chinese character 參 (pinyin shēn) originally meant the constellation Orion (Chinese: 參宿; pinyin: shēnxiù); its Shang dynasty version, over three millennia old, contains at the top a representation of the three stars of Orion's Belt atop a man's head (the bottom portion representing the sound of the word was added later). The Rigveda refers to the constellation as Mriga (the Deer). Nataraja, "the cosmic dancer", is often interpreted as the representation of Orion. Rudra, the Rigvedic form of Shiva, is the presiding deity of Ardra nakshatra (Betelgeuse) of Hindu astrology. The Jain Symbol carved in the Udayagiri and Khandagiri Caves, India in 1st century BCE has a striking resemblance with Orion. Bugis sailors identified the three stars in Orion's Belt as tanra tellué, meaning "sign of three". The Seri people of northwestern Mexico call the three stars in Orion's Belt Hapj (a name denoting a hunter) which consists of three stars: Hap (mule deer), Haamoja (pronghorn), and Mojet (bighorn sheep). Hap is in the middle and has been shot by the hunter; its blood has dripped onto Tiburón Island. The same three stars are known in Spain and most of Latin America as "Las tres Marías" (Spanish for "The Three Marys"). In Puerto Rico, the three stars are known as the "Los Tres Reyes Magos" (Spanish for The Three Wise Men). The Ojibwa/Chippewa Native Americans call this constellation Mesabi for Big Man. To the Lakota Native Americans, Tayamnicankhu (Orion's Belt) is the spine of a bison. The great rectangle of Orion is the bison's ribs; the Pleiades star cluster in nearby Taurus is the bison's head; and Sirius in Canis Major, known as Tayamnisinte, is its tail. Another Lakota myth mentions that the bottom half of Orion, the Constellation of the Hand, represented the arm of a chief that was ripped off by the Thunder People as a punishment from the gods for his selfishness. His daughter offered to marry the person who can retrieve his arm from the sky, so the young warrior Fallen Star (whose father was a star and whose mother was human) returned his arm and married his daughter, symbolizing harmony between the gods and humanity with the help of the younger generation. The index finger is represented by Rigel; the Orion Nebula is the thumb; the Belt of Orion is the wrist; and the star Beta Eridani is the pinky finger. The seven primary stars of Orion make up the Polynesian constellation Heiheionakeiki which represents a child's string figure similar to a cat's cradle. Several precolonial Filipinos referred to the belt region in particular as "balatik" (ballista) as it resembles a trap of the same name which fires arrows by itself and is usually used for catching pigs from the bush. Spanish colonization later led to some ethnic groups referring to Orion's Belt as "Tres Marias" or "Tatlong Maria." In Māori tradition, the star Rigel (known as Puanga or Puaka) is closely connected with the celebration of Matariki. The rising of Matariki (the Pleiades) and Rigel before sunrise in midwinter marks the start of the Māori year. In Javanese culture, the constellation is often called Lintang Waluku or Bintang Bajak, referring to the shape of a paddy field plow. The imagery of the Belt and Sword has found its way into popular Western culture, for example in the form of the shoulder insignia of the 27th Infantry Division of the United States Army during both World Wars, probably owing to a pun on the name of the division's first commander, Major General John F. O'Ryan. The film distribution company Orion Pictures used the constellation as its logo. In artistic renderings, the surrounding constellations are sometimes related to Orion: he is depicted standing next to the river Eridanus with his two hunting dogs Canis Major and Canis Minor, fighting Taurus. He is sometimes depicted hunting Lepus the hare. He sometimes is depicted to have a lion's hide in his hand. There are alternative ways to visualise Orion. From the Southern Hemisphere, Orion is oriented south-upward, and the Belt and Sword are sometimes called the saucepan or pot in Australia and New Zealand. Orion's Belt is called Drie Konings (Three Kings) or the Drie Susters (Three Sisters) by Afrikaans speakers in South Africa and are referred to as les Trois Rois (the Three Kings) in Daudet's Lettres de Mon Moulin (1866). The appellation Driekoningen (the Three Kings) is also often found in 17th and 18th-century Dutch star charts and seaman's guides. The same three stars are known in Spain, Latin America, and the Philippines as "Las Tres Marías" (The Three Marys), and as "Los Tres Reyes Magos" (The Three Wise Men) in Puerto Rico. Even traditional depictions of Orion have varied greatly. Cicero drew Orion in a similar fashion to the modern depiction. The Hunter held an unidentified animal skin aloft in his right hand; his hand was represented by Omicron2 Orionis and the skin was represented by the five stars designated Pi Orionis. Saiph and Rigel represented his left and right knees, while Eta Orionis and Lambda Leporis were his left and right feet, respectively. As in the modern depiction, Mintaka, Alnilam, and Alnitak represented his Belt. His left shoulder was represented by Betelgeuse, and Mu Orionis made up his left arm. Meissa was his head, and Bellatrix his right shoulder. The depiction of Hyginus was similar to that of Cicero, though the two differed in a few important areas. Cicero's animal skin became Hyginus's shield (Omicron and Pi Orionis), and instead of an arm marked out by Mu Orionis, he holds a club (Chi Orionis). His right leg is represented by Theta Orionis and his left leg is represented by Lambda, Mu, and Epsilon Leporis. Further Western European and Arabic depictions have followed these two models. Future Orion is located on the celestial equator, but it will not always be so located due to the effects of precession of the Earth's axis. Orion lies well south of the ecliptic, and it only happens to lie on the celestial equator because the point on the ecliptic that corresponds to the June solstice is close to the border of Gemini and Taurus, to the north of Orion. Precession will eventually carry Orion further south, and by AD 14000, Orion will be far enough south that it will no longer be visible from the latitude of Great Britain. Further in the future, Orion's stars will gradually move away from the constellation due to proper motion. However, Orion's brightest stars all lie at a large distance from Earth on an astronomical scale—much farther away than Sirius, for example. Orion will still be recognizable long after most of the other constellations—composed of relatively nearby stars—have distorted into new configurations, with the exception of a few of its stars eventually exploding as supernovae, for example Betelgeuse, which is predicted to explode sometime in the next million years. See also References External links |
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Contents Satya Nadella Satya Narayana Nadella[a] (born 19 August 1967) is an American business executive who is the chairman and chief executive officer (CEO) of Microsoft, succeeding Steve Ballmer in 2014 as CEO and John W. Thompson in 2021 as chairman.[b] Before becoming CEO, he was the executive vice president of Microsoft's cloud and enterprise group, responsible for building and running the company's computing platforms. Early life Nadella was born on 19 August 1967 in a Telugu Hindu family in Hyderabad. His father, Bukkapuram Nadella Yugandhar, was an Indian Administrative Service officer of the 1962 batch. His mother Prabhavati was a Sanskrit lecturer. Yugandhar hailed from Bukkapuram in Anantapur district of Andhra Pradesh; his own father had migrated to Bukkapuram from Nadella village in Guntur district (present-day Palnadu district) of Andhra Pradesh. Nadella attended the Hyderabad Public School, Begumpet before receiving a bachelor's degree in electrical engineering from the Manipal Institute of Technology in Karnataka in 1988. He then traveled to the United States to study for an MS in computer science at the University of Wisconsin–Milwaukee, receiving his degree in 1990. He received an MBA from the University of Chicago Booth School of Business in 1997. Career Nadella worked at Sun Microsystems as a member of its technology staff before joining Microsoft in 1992. At Microsoft, Nadella has led major projects that included the company's move to cloud computing and the development of one of the largest cloud infrastructures in the world. Nadella worked as the senior vice-president of research and development (R&D) for the Online Services Division and vice-president of the Microsoft Business Division. Later, he was made the president of Microsoft's $19 billion Server and Tools Business and led a transformation of the company's business and technology culture from client services to cloud infrastructure and services. He has been credited for helping bring Microsoft's database, Windows Server and developer tools to its Azure cloud. The revenue from Cloud Services grew to $20.3 billion in June 2013 from $16.6 billion when he took over in 2011. He received $84.5 million in 2016 pay. In 2013, Nadella's base salary was reportedly $669,167. Including stock bonuses, the total compensation stood at around $7.6 million. Previous positions held by Nadella include: On 4 February 2014, Nadella was announced as the new CEO of Microsoft, the third CEO in the company's history, following Bill Gates and Steve Ballmer. In October 2014, Nadella attended an event on Women in Computing and courted controversy after he made a statement that women should not ask for a raise and should trust the system. Nadella was criticised for the statement and he later apologized on Twitter. He then sent an email to Microsoft employees admitting he was "Completely wrong." Nadella's tenure at Microsoft has emphasized working with companies and technologies with which Microsoft also competes, including Apple Inc., Salesforce, IBM, and Dropbox. In contrast to previous Microsoft campaigns against the Linux operating system, Nadella proclaimed that "Microsoft ❤️ Linux", and Microsoft joined the Linux Foundation as a Platinum member in 2016. Under Nadella, Microsoft revised its mission statement to "empower every person and every organization on the planet to achieve more". He orchestrated a cultural shift at Microsoft by emphasizing empathy, collaboration, and 'growth mindset'. He has transformed Microsoft's corporate culture into one that emphasizes continual learning and growth. In 2014, Nadella's first acquisition with Microsoft was of Mojang, a Swedish game company best known for the computer game Minecraft, for $2.5 billion. He followed that by purchasing Xamarin for an undisclosed amount. He oversaw the purchase of professional network LinkedIn in 2016 for $26.2 billion. On 26 October 2018, Microsoft acquired GitHub for US$7.5 billion. As of November 2023, Microsoft stock had increased nearly tenfold since Nadella became CEO in 2014, with a 27% annual growth rate, ending a 14-year period of near zero growth. In 2024, Nadella's compensation from Microsoft totaled $79.1 million, an increase of 63% over his 2023 compensation of $48.5 million. In January 2026, Nadella demanded that people stop calling artificial intelligence "slop" and instead accept AI as the "new equilibrium" of human nature. The public reaction instead made people double down on the backlash, and the term "Microslop" became popular on social media, leading to it labeled a Streisand effect. Nadella, Soma Somasegar, Samir Bodas, Ashok Krishnamurthi, Sanjay Parthasarathy, and the GMR Group purchased the Seattle Orcas cricket team which is a part of 2023 Major League Cricket season. Awards and recognition In 2018 and 2024, Nadella was a Time 100 honoree. In 2019, he was named Financial Times Person of the Year and Fortune Magazine Businessperson of the Year. In 2014, Nadella was awarded the CNN-News18 Indian of the Year and in 2020, was recognized as Global Indian Business Icon at CNBC-TV18's India Business Leader Awards. In 2015, the Government of India awarded Nadella the Pravasi Bharatiya Samman (awarded to Overseas Indians) and in 2022 the Padma Bhushan, the third highest civilian award in India. Nadella was awarded an honorary PhD from the Georgia Institute of Technology in January 2024. Personal life In 1992, Nadella married Anupama Priyadarshini, the daughter of his father's Indian Administrative Service (IAS) batchmate. Both Nadella and Anupama are the only children from their parents. She was his junior at Manipal pursuing a B.Arch in the Faculty of Architecture. The couple have three children, a son (deceased) and two daughters, and live in Clyde Hill and Bellevue, Washington. His son Zain was a legally blind quadriplegic with cerebral palsy. Zain died in February 2022, at the age of 26. According to Nadella, being the father of a child with special needs was a turning point in his life. Nadella is an avid reader of American and Indian poetry and enjoys cricket, having played on his school team. He credits cricket for improving his leadership skills. Nadella and his wife Anupama are part of the ownership group of Seattle Sounders FC, a Major League Soccer club. In 2017, Nadella published a book titled Hit Refresh, exploring his life and career at Microsoft. He announced that the profits from the book would go to Microsoft Philanthropies and through that to nonprofit organizations. Publications Notes References External links |
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Contents Elon Musk Elon Reeve Musk (/ˈiːlɒn/ EE-lon; born June 28, 1971) is a businessman and entrepreneur known for his leadership of Tesla, SpaceX, Twitter, and xAI. Musk has been the wealthiest person in the world since 2025; as of February 2026,[update] Forbes estimates his net worth to be around US$852 billion. Born into a wealthy family in Pretoria, South Africa, Musk emigrated in 1989 to Canada; he has Canadian citizenship since his mother was born there. He received bachelor's degrees in 1997 from the University of Pennsylvania before moving to California to pursue business ventures. In 1995, Musk co-founded the software company Zip2. Following its sale in 1999, he co-founded X.com, an online payment company that later merged to form PayPal, which was acquired by eBay in 2002. Musk also became an American citizen in 2002. In 2002, Musk founded the space technology company SpaceX, becoming its CEO and chief engineer; the company has since led innovations in reusable rockets and commercial spaceflight. Musk joined the automaker Tesla as an early investor in 2004 and became its CEO and product architect in 2008; it has since become a leader in electric vehicles. In 2015, he co-founded OpenAI to advance artificial intelligence (AI) research, but later left; growing discontent with the organization's direction and their leadership in the AI boom in the 2020s led him to establish xAI, which became a subsidiary of SpaceX in 2026. In 2022, he acquired the social network Twitter, implementing significant changes, and rebranding it as X in 2023. His other businesses include the neurotechnology company Neuralink, which he co-founded in 2016, and the tunneling company the Boring Company, which he founded in 2017. In November 2025, a Tesla pay package worth $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Musk was the largest donor in the 2024 U.S. presidential election, where he supported Donald Trump. After Trump was inaugurated as president in early 2025, Musk served as Senior Advisor to the President and as the de facto head of the Department of Government Efficiency (DOGE). After a public feud with Trump, Musk left the Trump administration and returned to managing his companies. Musk is a supporter of global far-right figures, causes, and political parties. His political activities, views, and statements have made him a polarizing figure. Musk has been criticized for COVID-19 misinformation, promoting conspiracy theories, and affirming antisemitic, racist, and transphobic comments. His acquisition of Twitter was controversial due to a subsequent increase in hate speech and the spread of misinformation on the service, following his pledge to decrease censorship. His role in the second Trump administration attracted public backlash, particularly in response to DOGE. The emails he sent to Jeffrey Epstein are included in the Epstein files, which were published between 2025–26 and became a topic of worldwide debate. Early life Elon Reeve Musk was born on June 28, 1971, in Pretoria, South Africa's administrative capital. He is of British and Pennsylvania Dutch ancestry. His mother, Maye (née Haldeman), is a model and dietitian born in Saskatchewan, Canada, and raised in South Africa. Musk therefore holds both South African and Canadian citizenship from birth. His father, Errol Musk, is a South African electromechanical engineer, pilot, sailor, consultant, emerald dealer, and property developer, who partly owned a rental lodge at Timbavati Private Nature Reserve. His maternal grandfather, Joshua N. Haldeman, who died in a plane crash when Elon was a toddler, was an American-born Canadian chiropractor, aviator and political activist in the technocracy movement who moved to South Africa in 1950. Elon has a younger brother, Kimbal, a younger sister, Tosca, and four paternal half-siblings. Musk was baptized as a child in the Anglican Church of Southern Africa. Despite both Elon and Errol previously stating that Errol was a part owner of a Zambian emerald mine, in 2023, Errol recounted that the deal he made was to receive "a portion of the emeralds produced at three small mines". Errol was elected to the Pretoria City Council as a representative of the anti-apartheid Progressive Party and has said that his children shared their father's dislike of apartheid. After his parents divorced in 1979, Elon, aged around 9, chose to live with his father because Errol Musk had an Encyclopædia Britannica and a computer. Elon later regretted his decision and became estranged from his father. Elon has recounted trips to a wilderness school that he described as a "paramilitary Lord of the Flies" where "bullying was a virtue" and children were encouraged to fight over rations. In one incident, after an altercation with a fellow pupil, Elon was thrown down concrete steps and beaten severely, leading to him being hospitalized for his injuries. Elon described his father berating him after he was discharged from the hospital. Errol denied berating Elon and claimed, "The [other] boy had just lost his father to suicide, and Elon had called him stupid. Elon had a tendency to call people stupid. How could I possibly blame that child?" Elon was an enthusiastic reader of books, and had attributed his success in part to having read The Lord of the Rings, the Foundation series, and The Hitchhiker's Guide to the Galaxy. At age ten, he developed an interest in computing and video games, teaching himself how to program from the VIC-20 user manual. At age twelve, Elon sold his BASIC-based game Blastar to PC and Office Technology magazine for approximately $500 (equivalent to $1,600 in 2025). Musk attended Waterkloof House Preparatory School, Bryanston High School, and then Pretoria Boys High School, where he graduated. Musk was a decent but unexceptional student, earning a 61/100 in Afrikaans and a B on his senior math certification. Musk applied for a Canadian passport through his Canadian-born mother to avoid South Africa's mandatory military service, which would have forced him to participate in the apartheid regime, as well as to ease his path to immigration to the United States. While waiting for his application to be processed, he attended the University of Pretoria for five months. Musk arrived in Canada in June 1989, connected with a second cousin in Saskatchewan, and worked odd jobs, including at a farm and a lumber mill. In 1990, he entered Queen's University in Kingston, Ontario. Two years later, he transferred to the University of Pennsylvania, where he studied until 1995. Although Musk has said that he earned his degrees in 1995, the University of Pennsylvania did not award them until 1997 – a Bachelor of Arts in physics and a Bachelor of Science in economics from the university's Wharton School. He reportedly hosted large, ticketed house parties to help pay for tuition, and wrote a business plan for an electronic book-scanning service similar to Google Books. In 1994, Musk held two internships in Silicon Valley: one at energy storage startup Pinnacle Research Institute, which investigated electrolytic supercapacitors for energy storage, and another at Palo Alto–based startup Rocket Science Games. In 1995, he was accepted to a graduate program in materials science at Stanford University, but did not enroll. Musk decided to join the Internet boom of the 1990s, applying for a job at Netscape, to which he reportedly never received a response. The Washington Post reported that Musk lacked legal authorization to remain and work in the United States after failing to enroll at Stanford. In response, Musk said he was allowed to work at that time and that his student visa transitioned to an H1-B. According to numerous former business associates and shareholders, Musk said he was on a student visa at the time. Business career In 1995, Musk, his brother Kimbal, and Greg Kouri founded the web software company Zip2 with funding from a group of angel investors. They housed the venture at a small rented office in Palo Alto. Replying to Rolling Stone, Musk denounced the notion that they started their company with funds borrowed from Errol Musk, but in a tweet, he recognized that his father contributed 10% of a later funding round. The company developed and marketed an Internet city guide for the newspaper publishing industry, with maps, directions, and yellow pages. According to Musk, "The website was up during the day and I was coding it at night, seven days a week, all the time." To impress investors, Musk built a large plastic structure around a standard computer to create the impression that Zip2 was powered by a small supercomputer. The Musk brothers obtained contracts with The New York Times and the Chicago Tribune, and persuaded the board of directors to abandon plans for a merger with CitySearch. Musk's attempts to become CEO were thwarted by the board. Compaq acquired Zip2 for $307 million in cash in February 1999 (equivalent to $590,000,000 in 2025), and Musk received $22 million (equivalent to $43,000,000 in 2025) for his 7-percent share. In 1999, Musk co-founded X.com, an online financial services and e-mail payment company. The startup was one of the first federally insured online banks, and, in its initial months of operation, over 200,000 customers joined the service. The company's investors regarded Musk as inexperienced and replaced him with Intuit CEO Bill Harris by the end of the year. The following year, X.com merged with online bank Confinity to avoid competition. Founded by Max Levchin and Peter Thiel, Confinity had its own money-transfer service, PayPal, which was more popular than X.com's service. Within the merged company, Musk returned as CEO. Musk's preference for Microsoft software over Unix created a rift in the company and caused Thiel to resign. Due to resulting technological issues and lack of a cohesive business model, the board ousted Musk and replaced him with Thiel in 2000.[b] Under Thiel, the company focused on the PayPal service and was renamed PayPal in 2001. In 2002, PayPal was acquired by eBay for $1.5 billion (equivalent to $2,700,000,000 in 2025) in stock, of which Musk—the largest shareholder with 11.72% of shares—received $175.8 million (equivalent to $320,000,000 in 2025). In 2017, Musk purchased the domain X.com from PayPal for an undisclosed amount, stating that it had sentimental value. In 2001, Musk became involved with the nonprofit Mars Society and discussed funding plans to place a growth-chamber for plants on Mars. Seeking a way to launch the greenhouse payloads into space, Musk made two unsuccessful trips to Moscow to purchase intercontinental ballistic missiles (ICBMs) from Russian companies NPO Lavochkin and Kosmotras. Musk instead decided to start a company to build affordable rockets. With $100 million of his early fortune, (equivalent to $180,000,000 in 2025) Musk founded SpaceX in May 2002 and became the company's CEO and Chief Engineer. SpaceX attempted its first launch of the Falcon 1 rocket in 2006. Although the rocket failed to reach Earth orbit, it was awarded a Commercial Orbital Transportation Services program contract from NASA, then led by Mike Griffin. After two more failed attempts that nearly caused Musk to go bankrupt, SpaceX succeeded in launching the Falcon 1 into orbit in 2008. Later that year, SpaceX received a $1.6 billion NASA contract (equivalent to $2,400,000,000 in 2025) for Falcon 9-launched Dragon spacecraft flights to the International Space Station (ISS), replacing the Space Shuttle after its 2011 retirement. In 2012, the Dragon vehicle docked with the ISS, a first for a commercial spacecraft. Working towards its goal of reusable rockets, in 2015 SpaceX successfully landed the first stage of a Falcon 9 on a land platform. Later landings were achieved on autonomous spaceport drone ships, an ocean-based recovery platform. In 2018, SpaceX launched the Falcon Heavy; the inaugural mission carried Musk's personal Tesla Roadster as a dummy payload. Since 2019, SpaceX has been developing Starship, a reusable, super heavy-lift launch vehicle intended to replace the Falcon 9 and Falcon Heavy. In 2020, SpaceX launched its first crewed flight, the Demo-2, becoming the first private company to place astronauts into orbit and dock a crewed spacecraft with the ISS. In 2024, NASA awarded SpaceX an $843 million (equivalent to $865,000,000 in 2025) contract to build a spacecraft that NASA will use to deorbit the ISS at the end of its lifespan. In 2015, SpaceX began development of the Starlink constellation of low Earth orbit satellites to provide satellite Internet access. After the launch of prototype satellites in 2018, the first large constellation was deployed in May 2019. As of May 2025[update], over 7,600 Starlink satellites are operational, comprising 65% of all operational Earth satellites. The total cost of the decade-long project to design, build, and deploy the constellation was estimated by SpaceX in 2020 to be $10 billion (equivalent to $12,000,000,000 in 2025).[c] During the Russian invasion of Ukraine, Musk provided free Starlink service to Ukraine, permitting Internet access and communication at a yearly cost to SpaceX of $400 million (equivalent to $440,000,000 in 2025). However, Musk refused to block Russian state media on Starlink. In 2023, Musk denied Ukraine's request to activate Starlink over Crimea to aid an attack against the Russian navy, citing fears of a nuclear response. Tesla, Inc., originally Tesla Motors, was incorporated in July 2003 by Martin Eberhard and Marc Tarpenning. Both men played active roles in the company's early development prior to Musk's involvement. Musk led the Series A round of investment in February 2004; he invested $6.35 million (equivalent to $11,000,000 in 2025), became the majority shareholder, and joined Tesla's board of directors as chairman. Musk took an active role within the company and oversaw Roadster product design, but was not deeply involved in day-to-day business operations. Following a series of escalating conflicts in 2007 and the 2008 financial crisis, Eberhard was ousted from the firm.[page needed] Musk assumed leadership of the company as CEO and product architect in 2008. A 2009 lawsuit settlement with Eberhard designated Musk as a Tesla co-founder, along with Tarpenning and two others. Tesla began delivery of the Roadster, an electric sports car, in 2008. With sales of about 2,500 vehicles, it was the first mass production all-electric car to use lithium-ion battery cells. Under Musk, Tesla has since launched several well-selling electric vehicles, including the four-door sedan Model S (2012), the crossover Model X (2015), the mass-market sedan Model 3 (2017), the crossover Model Y (2020), and the pickup truck Cybertruck (2023). In May 2020, Musk resigned as chairman of the board as part of the settlement of a lawsuit from the SEC over him tweeting that funding had been "secured" for potentially taking Tesla private. The company has also constructed multiple lithium-ion battery and electric vehicle factories, called Gigafactories. Since its initial public offering in 2010, Tesla stock has risen significantly; it became the most valuable carmaker in summer 2020, and it entered the S&P 500 later that year. In October 2021, it reached a market capitalization of $1 trillion (equivalent to $1,200,000,000,000 in 2025), the sixth company in U.S. history to do so. Musk provided the initial concept and financial capital for SolarCity, which his cousins Lyndon and Peter Rive founded in 2006. By 2013, SolarCity was the second largest provider of solar power systems in the United States. In 2014, Musk promoted the idea of SolarCity building an advanced production facility in Buffalo, New York, triple the size of the largest solar plant in the United States. Construction of the factory started in 2014 and was completed in 2017. It operated as a joint venture with Panasonic until early 2020. Tesla acquired SolarCity for $2 billion in 2016 (equivalent to $2,700,000,000 in 2025) and merged it with its battery unit to create Tesla Energy. The deal's announcement resulted in a more than 10% drop in Tesla's stock price; at the time, SolarCity was facing liquidity issues. Multiple shareholder groups filed a lawsuit against Musk and Tesla's directors, stating that the purchase of SolarCity was done solely to benefit Musk and came at the expense of Tesla and its shareholders. Tesla directors settled the lawsuit in January 2020, leaving Musk the sole remaining defendant. Two years later, the court ruled in Musk's favor. In 2016, Musk co-founded Neuralink, a neurotechnology startup, with an investment of $100 million. Neuralink aims to integrate the human brain with artificial intelligence (AI) by creating devices that are embedded in the brain. Such technology could enhance memory or allow the devices to communicate with software. The company also hopes to develop devices to treat neurological conditions like spinal cord injuries. In 2022, Neuralink announced that clinical trials would begin by the end of the year. In September 2023, the Food and Drug Administration approved Neuralink to initiate six-year human trials. Neuralink has conducted animal testing on macaques at the University of California, Davis. In 2021, the company released a video in which a macaque played the video game Pong via a Neuralink implant. The company's animal trials—which have caused the deaths of some monkeys—have led to claims of animal cruelty. The Physicians Committee for Responsible Medicine has alleged that Neuralink violated the Animal Welfare Act. Employees have complained that pressure from Musk to accelerate development has led to botched experiments and unnecessary animal deaths. In 2022, a federal probe was launched into possible animal welfare violations by Neuralink.[needs update] In 2017, Musk founded the Boring Company to construct tunnels; he also revealed plans for specialized, underground, high-occupancy vehicles that could travel up to 150 miles per hour (240 km/h) and thus circumvent above-ground traffic in major cities. Early in 2017, the company began discussions with regulatory bodies and initiated construction of a 30-foot (9.1 m) wide, 50-foot (15 m) long, and 15-foot (4.6 m) deep "test trench" on the premises of SpaceX's offices, as that required no permits. The Los Angeles tunnel, less than two miles (3.2 km) in length, debuted to journalists in 2018. It used Tesla Model Xs and was reported to be a rough ride while traveling at suboptimal speeds. Two tunnel projects announced in 2018, in Chicago and West Los Angeles, have been canceled. A tunnel beneath the Las Vegas Convention Center was completed in early 2021. Local officials have approved further expansions of the tunnel system. April 14, 2022 In early 2017, Musk expressed interest in buying Twitter and had questioned the platform's commitment to freedom of speech. By 2022, Musk had reached 9.2% stake in the company, making him the largest shareholder.[d] Musk later agreed to a deal that would appoint him to Twitter's board of directors and prohibit him from acquiring more than 14.9% of the company. Days later, Musk made a $43 billion offer to buy Twitter. By the end of April Musk had successfully concluded his bid for approximately $44 billion. This included approximately $12.5 billion in loans and $21 billion in equity financing. Having backtracked on his initial decision, Musk bought the company on October 27, 2022. Immediately after the acquisition, Musk fired several top Twitter executives including CEO Parag Agrawal; Musk became the CEO instead. Under Elon Musk, Twitter instituted monthly subscriptions for a "blue check", and laid off a significant portion of the company's staff. Musk lessened content moderation and hate speech also increased on the platform after his takeover. In late 2022, Musk released internal documents relating to Twitter's moderation of Hunter Biden's laptop controversy in the lead-up to the 2020 presidential election. Musk also promised to step down as CEO after a Twitter poll, and five months later, Musk stepped down as CEO and transitioned his role to executive chairman and chief technology officer (CTO). Despite Musk stepping down as CEO, X continues to struggle with challenges such as viral misinformation, hate speech, and antisemitism controversies. Musk has been accused of trying to silence some of his critics such as Twitch streamer Asmongold, who criticized him during one of his streams. Musk has been accused of removing their accounts' blue checkmarks, which hinders visibility and is considered a form of shadow banning, or suspending their accounts without justification. Other activities In August 2013, Musk announced plans for a version of a vactrain, and assigned engineers from SpaceX and Tesla to design a transport system between Greater Los Angeles and the San Francisco Bay Area, at an estimated cost of $6 billion. Later that year, Musk unveiled the concept, dubbed the Hyperloop, intended to make travel cheaper than any other mode of transport for such long distances. In December 2015, Musk co-founded OpenAI, a not-for-profit artificial intelligence (AI) research company aiming to develop artificial general intelligence, intended to be safe and beneficial to humanity. Musk pledged $1 billion of funding to the company, and initially gave $50 million. In 2018, Musk left the OpenAI board. Since 2018, OpenAI has made significant advances in machine learning. In July 2023, Musk launched the artificial intelligence company xAI, which aims to develop a generative AI program that competes with existing offerings like OpenAI's ChatGPT. Musk obtained funding from investors in SpaceX and Tesla, and xAI hired engineers from Google and OpenAI. December 16, 2022 Musk uses a private jet owned by Falcon Landing LLC, a SpaceX-linked company, and acquired a second jet in August 2020. His heavy use of the jets and the consequent fossil fuel usage have received criticism. Musk's flight usage is tracked on social media through ElonJet. In December 2022, Musk banned the ElonJet account on Twitter, and made temporary bans on the accounts of journalists that posted stories regarding the incident, including Donie O'Sullivan, Keith Olbermann, and journalists from The New York Times, The Washington Post, CNN, and The Intercept. In October 2025, Musk's company xAI launched Grokipedia, an AI-generated online encyclopedia that he promoted as an alternative to Wikipedia. Articles on Grokipedia are generated and reviewed by xAI's Grok chatbot. Media coverage and academic analysis described Grokipedia as frequently reusing Wikipedia content but framing contested political and social topics in line with Musk's own views and right-wing narratives. A study by Cornell University researchers and NBC News stated that Grokipedia cites sources that are blacklisted or considered "generally unreliable" on Wikipedia, for example, the conspiracy site Infowars and the neo-Nazi forum Stormfront. Wired, The Guardian and Time criticized Grokipedia for factual errors and for presenting Musk himself in unusually positive terms while downplaying controversies. Politics Musk is an outlier among business leaders who typically avoid partisan political advocacy. Musk was a registered independent voter when he lived in California. Historically, he has donated to both Democrats and Republicans, many of whom serve in states in which he has a vested interest. Since 2022, his political contributions have mostly supported Republicans, with his first vote for a Republican going to Mayra Flores in the 2022 Texas's 34th congressional district special election. In 2024, he started supporting international far-right political parties, activists, and causes, and has shared misinformation and numerous conspiracy theories. Since 2024, his views have been generally described as right-wing. Musk supported Barack Obama in 2008 and 2012, Hillary Clinton in 2016, Joe Biden in 2020, and Donald Trump in 2024. In the 2020 Democratic Party presidential primaries, Musk endorsed candidate Andrew Yang and expressed support for Yang's proposed universal basic income, and endorsed Kanye West's 2020 presidential campaign. In 2021, Musk publicly expressed opposition to the Build Back Better Act, a $3.5 trillion legislative package endorsed by Joe Biden that ultimately failed to pass due to unanimous opposition from congressional Republicans and several Democrats. In 2022, gave over $50 million to Citizens for Sanity, a conservative political action committee. In 2023, he supported Republican Ron DeSantis for the 2024 U.S. presidential election, giving $10 million to his campaign, and hosted DeSantis's campaign announcement on a Twitter Spaces event. From June 2023 to January 2024, Musk hosted a bipartisan set of X Spaces with Republican and Democratic candidates, including Robert F. Kennedy Jr., Vivek Ramaswamy, and Dean Phillips. In October 2025, former vice-president Kamala Harris commented that it was a mistake from the Democratic side to not invite Musk to a White House electric vehicle event organized in August 2021 and featuring executives from General Motors, Ford and Stellantis, despite Tesla being "the major American manufacturer of extraordinary innovation in this space." Fortune remarked that this was a nod to United Auto Workers and organized labor. Harris said presidents should put aside political loyalties when it came to recognizing innovation, and guessed that the non-invitation impacted Musk's perspective. Fortune noted that, at the time, Musk said, "Yeah, seems odd that Tesla wasn't invited." A month later, he criticized Biden as "not the friendliest administration." Jacob Silverman, author of the book Gilded Rage: Elon Musk and the Radicalization of Silicon Valley, said that the tech industry represented by Musk, Thiel, Andreessen and other capitalists, actually flourished under Biden, but the tech leaders chose Trump for their common ground on cultural issues. By early 2024, Musk had become a vocal and financial supporter of Donald Trump. In July 2024, minutes after the attempted assassination of Donald Trump, Musk endorsed him for president saying; "I fully endorse President Trump and hope for his rapid recovery." During the presidential campaign, Musk joined Trump on stage at a campaign rally, and during the campaign promoted conspiracy theories and falsehoods about Democrats, election fraud and immigration, in support of Trump. Musk was the largest individual donor of the 2024 election. In 2025, Musk contributed $19 million to the Wisconsin Supreme Court race, hoping to influence the state's future redistricting efforts and its regulations governing car manufacturers and dealers. In 2023, Musk said he shunned the World Economic Forum because it was boring. The organization commented that they had not invited him since 2015. He has participated in Dialog, dubbed "Tech Bilderberg" and organized by Peter Thiel and Auren Hoffman, though. Musk's international political actions and comments have come under increasing scrutiny and criticism, especially from the governments and leaders of France, Germany, Norway, Spain and the United Kingdom, particularly due to his position in the U.S. government as well as ownership of X. An NBC News analysis found he had boosted far-right political movements to cut immigration and curtail regulation of business in at least 18 countries on six continents since 2023. During his speech after the second inauguration of Donald Trump, Musk twice made a gesture interpreted by many as a Nazi or a fascist Roman salute.[e] He thumped his right hand over his heart, fingers spread wide, and then extended his right arm out, emphatically, at an upward angle, palm down and fingers together. He then repeated the gesture to the crowd behind him. As he finished the gestures, he said to the crowd, "My heart goes out to you. It is thanks to you that the future of civilization is assured." It was widely condemned as an intentional Nazi salute in Germany, where making such gestures is illegal. The Anti-Defamation League said it was not a Nazi salute, but other Jewish organizations disagreed and condemned the salute. American public opinion was divided on partisan lines as to whether it was a fascist salute. Musk dismissed the accusations of Nazi sympathies, deriding them as "dirty tricks" and a "tired" attack. Neo-Nazi and white supremacist groups celebrated it as a Nazi salute. Multiple European political parties demanded that Musk be banned from entering their countries. The concept of DOGE emerged in a discussion between Musk and Donald Trump, and in August 2024, Trump committed to giving Musk an advisory role, with Musk accepting the offer. In November and December 2024, Musk suggested that the organization could help to cut the U.S. federal budget, consolidate the number of federal agencies, and eliminate the Consumer Financial Protection Bureau, and that its final stage would be "deleting itself". In January 2025, the organization was created by executive order, and Musk was designated a "special government employee". Musk led the organization and was a senior advisor to the president, although his official role is not clear. In sworn statement during a lawsuit, the director of the White House Office of Administration stated that Musk "is not an employee of the U.S. DOGE Service or U.S. DOGE Service Temporary Organization", "is not the U.S. DOGE Service administrator", and has "no actual or formal authority to make government decisions himself". Trump said two days later that he had put Musk in charge of DOGE. A federal judge has ruled that Musk acted as the de facto leader of DOGE. Musk's role in the second Trump administration, particularly in response to DOGE, has attracted public backlash. He was criticized for his treatment of federal government employees, including his influence over the mass layoffs of the federal workforce. He has prioritized secrecy within the organization and has accused others of violating privacy laws. A Senate report alleged that Musk could avoid up to $2 billion in legal liability as a result of DOGE's actions. In May 2025, Bill Gates accused Musk of "killing the world's poorest children" through his cuts to USAID, which modeling by Boston University estimated had resulted in 300,000 deaths by this time, most of them of children. By November 2025, the estimated death toll had increased to 400,000 children and 200,000 adults. Musk announced on May 28, 2025, that he would depart from the Trump administration as planned when the special government employee's 130 day deadline expired, with a White House official confirming that Musk's offboarding from the Trump administration was already underway. His departure was officially confirmed during a joint Oval Office press conference with Trump on May 30, 2025. @realDonaldTrump is in the Epstein files. That is the real reason they have not been made public. June 5, 2025 After leaving office, Musk criticized the Trump administration's Big Beautiful Bill, calling it a "disgusting abomination" due to its provisions increasing the deficit. A feud began between Musk and Trump, with its most notable event being Musk alleging Trump had ties to sex offender Jeffrey Epstein on X (formerly Twitter) on June 5, 2025. Trump responded on Truth Social stating that Musk went "CRAZY" after the "EV Mandate" was purportedly taken away and threatened to cut Musk's government contracts. Musk then called for a third Trump impeachment. The next day, Trump stated that he did not wish to reconcile with Musk, and added that Musk would face "very serious consequences" if he funds Democratic candidates. On June 11, Musk publicly apologized for the tweets against Trump, saying they "went too far". Views November 6, 2022 Rejecting the conservative label, Musk has described himself as a political moderate, even as his views have become more right-wing over time. His views have been characterized as libertarian and far-right, and after his involvement in European politics, they have received criticism from world leaders such as Emmanuel Macron and Olaf Scholz. Within the context of American politics, Musk supported Democratic candidates up until 2022, at which point he voted for a Republican for the first time. He has stated support for universal basic income, gun rights, freedom of speech, a tax on carbon emissions, and H-1B visas. Musk has expressed concern about issues such as artificial intelligence (AI) and climate change, and has been a critic of wealth tax, short-selling, and government subsidies. An immigrant himself, Musk has been accused of being anti-immigration, and regularly blames immigration policies for illegal immigration. He is also a pronatalist who believes population decline is the biggest threat to civilization, and identifies as a cultural Christian. Musk has long been an advocate for space colonization, especially the colonization of Mars. He has repeatedly pushed for humanity colonizing Mars, in order to become an interplanetary species and lower the risks of human extinction. Musk has promoted conspiracy theories and made controversial statements that have led to accusations of racism, sexism, antisemitism, transphobia, disseminating disinformation, and support of white pride. While describing himself as a "pro-Semite", his comments regarding George Soros and Jewish communities have been condemned by the Anti-Defamation League and the Biden White House. Musk was criticized during the COVID-19 pandemic for making unfounded epidemiological claims, defying COVID-19 lockdowns restrictions, and supporting the Canada convoy protest against vaccine mandates. He has amplified false claims of white genocide in South Africa. Musk has been critical of Israel's actions in the Gaza Strip during the Gaza war, praised China's economic and climate goals, suggested that Taiwan and China should resolve cross-strait relations, and was described as having a close relationship with the Chinese government. In Europe, Musk expressed support for Ukraine in 2022 during the Russian invasion, recommended referendums and peace deals on the annexed Russia-occupied territories, and supported the far-right Alternative for Germany political party in 2024. Regarding British politics, Musk blamed the 2024 UK riots on mass migration and open borders, criticized Prime Minister Keir Starmer for what he described as a "two-tier" policing system, and was subsequently attacked as being responsible for spreading misinformation and amplifying the far-right. He has also voiced his support for far-right activist Tommy Robinson and pledged electoral support for Reform UK. In February 2026, Musk described Spanish Prime Minister Pedro Sánchez as a "tyrant" following Sánchez's proposal to prohibit minors under the age of 16 from accessing social media platforms. Legal affairs In 2018, Musk was sued by the U.S. Securities and Exchange Commission (SEC) for a tweet stating that funding had been secured for potentially taking Tesla private.[f] The securities fraud lawsuit characterized the tweet as false, misleading, and damaging to investors, and sought to bar Musk from serving as CEO of publicly traded companies. Two days later, Musk settled with the SEC, without admitting or denying the SEC's allegations. As a result, Musk and Tesla were fined $20 million each, and Musk was forced to step down for three years as Tesla chairman but was able to remain as CEO. Shareholders filed a lawsuit over the tweet, and in February 2023, a jury found Musk and Tesla not liable. Musk has stated in interviews that he does not regret posting the tweet that triggered the SEC investigation. In 2019, Musk stated in a tweet that Tesla would build half a million cars that year. The SEC reacted by asking a court to hold him in contempt for violating the terms of the 2018 settlement agreement. A joint agreement between Musk and the SEC eventually clarified the previous agreement details, including a list of topics about which Musk needed preclearance. In 2020, a judge blocked a lawsuit that claimed a tweet by Musk regarding Tesla stock price ("too high imo") violated the agreement. Freedom of Information Act (FOIA)-released records showed that the SEC concluded Musk had subsequently violated the agreement twice by tweeting regarding "Tesla's solar roof production volumes and its stock price". In October 2023, the SEC sued Musk over his refusal to testify a third time in an investigation into whether he violated federal law by purchasing Twitter stock in 2022. In February 2024, Judge Laurel Beeler ruled that Musk must testify again. In January 2025, the SEC filed a lawsuit against Musk for securities violations related to his purchase of Twitter. In January 2024, Delaware judge Kathaleen McCormick ruled in a 2018 lawsuit that Musk's $55 billion pay package from Tesla be rescinded. McCormick called the compensation granted by the company's board "an unfathomable sum" that was unfair to shareholders. The Delaware Supreme Court overturned McCormick's decision in December 2025, restoring Musk's compensation package and awarding $1 in nominal damages. Personal life Musk became a U.S. citizen in 2002. From the early 2000s until late 2020, Musk resided in California, where both Tesla and SpaceX were founded. He then relocated to Cameron County, Texas, saying that California had become "complacent" about its economic success. While hosting Saturday Night Live in 2021, Musk stated that he has Asperger syndrome (an outdated term for autism spectrum disorder). When asked about his experience growing up with Asperger's syndrome in a TED2022 conference in Vancouver, Musk stated that "the social cues were not intuitive ... I would just tend to take things very literally ... but then that turned out to be wrong — [people were not] simply saying exactly what they mean, there's all sorts of other things that are meant, and [it] took me a while to figure that out." Musk suffers from back pain and has undergone several spine-related surgeries, including a disc replacement. In 2000, he contracted a severe case of malaria while on vacation in South Africa. Musk has stated he uses doctor-prescribed ketamine for occasional depression and that he doses "a small amount once every other week or something like that"; since January 2024, some media outlets have reported that he takes ketamine, marijuana, LSD, ecstasy, mushrooms, cocaine and other drugs. Musk at first refused to comment on his alleged drug use, before responding that he had not tested positive for drugs, and that if drugs somehow improved his productivity, "I would definitely take them!". The New York Times' investigations revealed Musk's overuse of ketamine and numerous other drugs, as well as strained family relationships and concerns from close associates who have become troubled by his public behavior as he became more involved in political activities and government work. According to The Washington Post, President Trump described Musk as "a big-time drug addict". Through his own label Emo G Records, Musk released a rap track, "RIP Harambe", on SoundCloud in March 2019. The following year, he released an EDM track, "Don't Doubt Ur Vibe", featuring his own lyrics and vocals. Musk plays video games, which he stated has a "'restoring effect' that helps his 'mental calibration'". Some games he plays include Quake, Diablo IV, Elden Ring, and Polytopia. Musk once claimed to be one of the world's top video game players but has since admitted to "account boosting", or cheating by hiring outside services to achieve top player rankings. Musk has justified the boosting by claiming that all top accounts do it so he has to as well to remain competitive. In 2024 and 2025, Musk criticized the video game Assassin's Creed Shadows and its creator Ubisoft for "woke" content. Musk posted to X that "DEI kills art" and specified the inclusion of the historical figure Yasuke in the Assassin's Creed game as offensive; he also called the game "terrible". Ubisoft responded by saying that Musk's comments were "just feeding hatred" and that they were focused on producing a game not pushing politics. Musk has fathered at least 14 children, one of whom died as an infant. The Wall Street Journal reported in 2025 that sources close to Musk suggest that the "true number of Musk's children is much higher than publicly known". He had six children with his first wife, Canadian author Justine Wilson, whom he met while attending Queen's University in Ontario, Canada; they married in 2000. In 2002, their first child Nevada Musk died of sudden infant death syndrome at the age of 10 weeks. After his death, the couple used in vitro fertilization (IVF) to continue their family; they had twins in 2004, followed by triplets in 2006. The couple divorced in 2008 and have shared custody of their children. The elder twin he had with Wilson came out as a trans woman and, in 2022, officially changed her name to Vivian Jenna Wilson, adopting her mother's surname because she no longer wished to be associated with Musk. Musk began dating English actress Talulah Riley in 2008. They married two years later at Dornoch Cathedral in Scotland. In 2012, the couple divorced, then remarried the following year. After briefly filing for divorce in 2014, Musk finalized a second divorce from Riley in 2016. Musk then dated the American actress Amber Heard for several months in 2017; he had reportedly been "pursuing" her since 2012. In 2018, Musk and Canadian musician Grimes confirmed they were dating. Grimes and Musk have three children, born in 2020, 2021, and 2022.[g] Musk and Grimes originally gave their eldest child the name "X Æ A-12", which would have violated California regulations as it contained characters that are not in the modern English alphabet; the names registered on the birth certificate are "X" as a first name, "Æ A-Xii" as a middle name, and "Musk" as a last name. They received criticism for choosing a name perceived to be impractical and difficult to pronounce; Musk has said the intended pronunciation is "X Ash A Twelve". Their second child was born via surrogacy. Despite the pregnancy, Musk confirmed reports that the couple were "semi-separated" in September 2021; in an interview with Time in December 2021, he said he was single. In October 2023, Grimes sued Musk over parental rights and custody of X Æ A-Xii. Elon Musk has taken X Æ A-Xii to multiple official events in Washington, D.C. during Trump's second term in office. Also in July 2022, The Wall Street Journal reported that Musk allegedly had an affair with Nicole Shanahan, the wife of Google co-founder Sergey Brin, in 2021, leading to their divorce the following year. Musk denied the report. Musk also had a relationship with Australian actress Natasha Bassett, who has been described as "an occasional girlfriend". In October 2024, The New York Times reported Musk bought a Texas compound for his children and their mothers, though Musk denied having done so. Musk also has four children with Shivon Zilis, director of operations and special projects at Neuralink: twins born via IVF in 2021, a child born in 2024 via surrogacy and a child born in 2025.[h] On February 14, 2025, Ashley St. Clair, an influencer and author, posted on X claiming to have given birth to Musk's son Romulus five months earlier, which media outlets reported as Musk's supposed thirteenth child.[i] On February 22, 2025, it was reported that St Clair had filed for sole custody of her five-month-old son and for Musk to be recognised as the child's father. On March 31, 2025, Musk wrote that, while he was unsure if he was the father of St. Clair's child, he had paid St. Clair $2.5 million and would continue paying her $500,000 per year.[j] Later reporting from the Wall Street Journal indicated that $1 million of these payments to St. Clair were structured as a loan. In 2014, Musk and Ghislaine Maxwell appeared together in a photograph taken at an Academy Awards after-party, which Musk later described as a "photobomb". The January 2026 Epstein files contain emails between Musk and Epstein from 2012 to 2013, after Epstein's first conviction. Emails released on January 30, 2026, indicated that Epstein invited Musk to visit his private island on multiple occasions. The correspondence showed that while Epstein repeatedly encouraged Musk to attend, Musk did not visit the island. In one instance, Musk discussed the possibility of attending a party with his then-wife Talulah Riley and asked which day would be the "wildest party"; according to the emails, the visit did not take place after Epstein later cancelled the plans.[k] On Christmas day in 2012, Musk emailed Epstein asking "Do you have any parties planned? I’ve been working to the edge of sanity this year and so, once my kids head home after Christmas, I really want to hit the party scene in St Barts or elsewhere and let loose. The invitation is much appreciated, but a peaceful island experience is the opposite of what I’m looking for". Epstein replied that the "ratio on my island" might make Musk's wife uncomfortable to which Musk responded, "Ratio is not a problem for Talulah". On September 11, 2013, Epstein sent an email asking Musk if he had any plans for coming to New York for the opening of the United Nations General Assembly where many "interesting people" would be coming to his house to which Musk responded that "Flying to NY to see UN diplomats do nothing would be an unwise use of time". Epstein responded by stating "Do you think i am retarded. Just kidding, there is no one over 25 and all very cute." Musk has denied any close relationship with Epstein and described him as a "creep" who attempted to ingratiate himself with influential people. When Musk was asked in 2019 if he introduced Epstein to Mark Zuckerberg, Musk responded: "I don’t recall introducing Epstein to anyone, as I don’t know the guy well enough to do so." The released emails nonetheless showed cordial exchanges on a range of topics, including Musk's inquiry about parties on the island. The correspondence also indicated that Musk suggested hosting Epstein at SpaceX, while Epstein separately discussed plans to tour SpaceX and bring "the girls", though there is no evidence that such a visit occurred. Musk has described the release of the files a "distraction", later accusing the second Trump administration of suppressing them to protect powerful individuals, including Trump himself.[l] Wealth Elon Musk is the wealthiest person in the world, with an estimated net worth of US$690 billion as of January 2026, according to the Bloomberg Billionaires Index, and $852 billion according to Forbes, primarily from his ownership stakes in SpaceX and Tesla. Having been first listed on the Forbes Billionaires List in 2012, around 75% of Musk's wealth was derived from Tesla stock in November 2020, although he describes himself as "cash poor". According to Forbes, he became the first person in the world to achieve a net worth of $300 billion in 2021; $400 billion in December 2024; $500 billion in October 2025; $600 billion in mid-December 2025; $700 billion later that month; and $800 billion in February 2026. In November 2025, a Tesla pay package worth potentially $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Public image Although his ventures have been highly influential within their separate industries starting in the 2000s, Musk only became a public figure in the early 2010s. He has been described as an eccentric who makes spontaneous and impactful decisions, while also often making controversial statements, contrary to other billionaires who prefer reclusiveness to protect their businesses. Musk's actions and his expressed views have made him a polarizing figure. Biographer Ashlee Vance described people's opinions of Musk as polarized due to his "part philosopher, part troll" persona on Twitter. He has drawn denouncement for using his platform to mock the self-selection of personal pronouns, while also receiving praise for bringing international attention to matters like British survivors of grooming gangs. Musk has been described as an American oligarch due to his extensive influence over public discourse, social media, industry, politics, and government policy. After Trump's re-election, Musk's influence and actions during the transition period and the second presidency of Donald Trump led some to call him "President Musk", the "actual president-elect", "shadow president" or "co-president". Awards for his contributions to the development of the Falcon rockets include the American Institute of Aeronautics and Astronautics George Low Transportation Award in 2008, the Fédération Aéronautique Internationale Gold Space Medal in 2010, and the Royal Aeronautical Society Gold Medal in 2012. In 2015, he received an honorary doctorate in engineering and technology from Yale University and an Institute of Electrical and Electronics Engineers Honorary Membership. Musk was elected a Fellow of the Royal Society (FRS) in 2018.[m] In 2022, Musk was elected to the National Academy of Engineering. Time has listed Musk as one of the most influential people in the world in 2010, 2013, 2018, and 2021. Musk was selected as Time's "Person of the Year" for 2021. Then Time editor-in-chief Edward Felsenthal wrote that, "Person of the Year is a marker of influence, and few individuals have had more influence than Musk on life on Earth, and potentially life off Earth too." Notes References Works cited Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Platyhelmintha] | [TOKENS: 6238] |
Contents Flatworm Traditional: Phylogenetic: Platyhelminthes (from Ancient Greek πλατύ platy 'flat' and ἕλμινς helmins 'parasitic worm') is a phylum of relatively simple bilaterian, unsegmented, soft-bodied invertebrates commonly called flatworms or flat worms. Being acoelomates (having no body cavity), and having no specialised circulatory and respiratory organs, they are restricted to having flattened shapes that allow oxygen and nutrients to pass through their bodies by diffusion. The digestive cavity has only one opening for both ingestion (intake of nutrients) and egestion (removal of undigested wastes); as a result, the food can not be processed continuously. In traditional medicinal texts, Platyhelminthes are divided into Turbellaria, which are mostly non-parasitic animals such as planarians, and three entirely parasitic groups: Cestoda, Trematoda and Monogenea; however, since the turbellarians have since been proven not to be monophyletic, this classification is now deprecated. Free-living flatworms are mostly predators, and live in water or in shaded, humid terrestrial environments, such as leaf litter. Cestodes (tapeworms) and trematodes (flukes) have complex life-cycles, with mature stages that live as parasites in the digestive systems of fish or land vertebrates, and intermediate stages that infest secondary hosts. The eggs of trematodes are excreted from their main hosts, whereas adult cestodes generate vast numbers of hermaphroditic, segment-like proglottids that detach when mature, are excreted, and then release eggs. Unlike the other parasitic groups, the monogeneans are external parasites infesting aquatic animals, and their larvae metamorphose into the adult form after attaching to a suitable host. Because they do not have internal body cavities, Platyhelminthes were regarded as a primitive stage in the evolution of bilaterians (animals with bilateral symmetry and hence with distinct front and rear ends). However, analyses since the mid-1980s have separated out one subgroup, the Acoelomorpha, as basal bilaterians – closer to the original bilaterians than to any other modern groups. The remaining Platyhelminthes form a monophyletic group, one that contains all and only descendants of a common ancestor that is itself a member of the group. The redefined Platyhelminthes is part of the Spiralia, one of the two main groups of Protostomia. These analyses had concluded the redefined Platyhelminthes, excluding Acoelomorpha, consists of two monophyletic subgroups, Catenulida and Rhabditophora, with Cestoda, Trematoda and Monogenea forming a monophyletic subgroup within one branch of the Rhabditophora. Hence, the traditional platyhelminth subgroup "Turbellaria" is now regarded as paraphyletic, since it excludes the wholly parasitic groups, although these are descended from one group of "turbellarians". A planarian species has been used in the Philippines and the Maldives in an attempt to control populations of the imported giant African snail (Achatina fulica), which was eating agricultural crops. Success was initially reported for the Maldives but this was only temporary and the role of flatworms has been questioned. These planarians have now spread very widely throughout the tropics and are themselves a serious threat to native snails, and should not be used for biological control. In Northwestern Europe, there are concerns about the spread of the New Zealand planarian Arthurdendyus triangulatus, which preys on earthworms. Description Platyhelminthes are bilaterally symmetrical animals: their left and right sides are mirror images of each other; this also implies they have distinct top and bottom surfaces and distinct head and tail ends. Like other bilaterians, they have three main cell layers (endoderm, mesoderm, and ectoderm), while the radially symmetrical cnidarians and ctenophores (comb jellies) have only two cell layers. Beyond that, they are "defined more by what they do not have than by any particular series of specializations." Unlike most other bilaterians, Platyhelminthes have no internal body cavity, so are described as acoelomates. Although the absence of a coelom also occurs in other bilaterians: gnathostomulids, gastrotrichs, xenacoelomorphs, cycliophorans, entoproctans and the parasitic mesozoans. They also lack specialized circulatory and respiratory organs, both of these facts are defining features when classifying a flatworm's anatomy. Their bodies are soft and unsegmented. The lack of circulatory and respiratory organs limits platyhelminths to sizes and shapes that enable oxygen to reach and carbon dioxide to leave all parts of their bodies by simple diffusion. Hence, many are microscopic, and the large species have flat ribbon-like or leaf-like shapes. Because there is no circulatory system which can transport nutrients around, the guts of large species have many branches, allowing the nutrients to diffuse to all parts of the body. Respiration through the whole surface of the body makes them vulnerable to fluid loss, and restricts them to environments where dehydration is unlikely: sea and freshwater, moist terrestrial environments such as leaf litter or between grains of soil, and as parasites within other animals. The space between the skin and gut is filled with mesenchyme, also known as parenchyma, a connective tissue made of cells and reinforced by collagen fibers that act as a type of skeleton, providing attachment points for muscles. The mesenchyme contains all the internal organs and allows the passage of oxygen, nutrients and waste products. It consists of two main types of cell: fixed cells, some of which have fluid-filled vacuoles; and stem cells, which can transform into any other type of cell, and are used in regenerating tissues after injury or asexual reproduction. Most platyhelminths have no anus and regurgitate undigested material through the mouth. The genus Paracatenula, whose members include tiny flatworms living in symbiosis with bacteria, is even missing a mouth and a gut. However, some long species have an anus and some with complex, branched guts have more than one anus, since excretion only through the mouth would be difficult for them. The gut is lined with a single layer of endodermal cells that absorb and digest food. Some species break up and soften food first by secreting enzymes in the gut or pharynx (throat). All animals need to keep the concentration of dissolved substances in their body fluids at a fairly constant level. Internal parasites and free-living marine animals live in environments with high concentrations of dissolved material, and generally let their tissues have the same level of concentration as the environment, while freshwater animals need to prevent their body fluids from becoming too dilute. Despite this difference in environments, most platyhelminths use the same system to control the concentration of their body fluids. Flame cells, so called because the beating of their flagella looks like a flickering candle flame, extract from the mesenchyme water that contains wastes and some reusable material, and drive it into networks of tube cells which are lined with flagella and microvilli. The tube cells' flagella drive the water towards exits called nephridiopores, while their microvilli reabsorb reusable materials and as much water as is needed to keep the body fluids at the right concentration. These combinations of flame cells and tube cells are called protonephridia. In all platyhelminths, the nervous system is concentrated at the head end. Other platyhelminths have rings of ganglia in the head and main nerve trunks running along their bodies. Major subgroups Early classification divided the flatworms in four groups: Turbellaria, Trematoda, Monogenea and Cestoda. This classification had long been recognized to be artificial, and in 1985, Ehlers proposed a phylogenetically more correct classification, where the massively polyphyletic "Turbellaria" was split into a dozen orders, and Trematoda, Monogenea and Cestoda were joined in the new order Neodermata. However, the classification presented here is the early, traditional, classification, as it still is the one used everywhere except in scientific articles. These have about 4,500 species, are mostly free-living, and range from 1 mm (0.04 in) to 600 mm (24 in) in length. Most are predators or scavengers, and terrestrial species are mostly nocturnal and live in shaded, humid locations, such as leaf litter or rotting wood. However, some are symbiotes of other animals, such as crustaceans, and some are parasites. Free-living turbellarians are mostly black, brown or gray, but some larger ones are brightly colored. The Acoela and Nemertodermatida were traditionally regarded as turbellarians, but are now regarded as members of a separate phylum, the Acoelomorpha, or as two separate phyla. Xenoturbella, a genus of very simple animals, has also been reclassified as a separate phylum. Some turbellarians have a simple pharynx lined with cilia and generally feed by using cilia to sweep food particles and small prey into their mouths, which are usually in the middle of their undersides. Most other turbellarians have a pharynx that is eversible (can be extended by being turned inside-out), and the mouths of different species can be anywhere along the underside. The freshwater species Microstomum caudatum can open its mouth almost as wide as its body is long, to swallow prey about as large as itself. Predatory species in suborder Kalyptorhynchia often have a muscular pharynx equipped with hooks or teeth used for seizing prey. Most turbellarians have pigment-cup ocelli ('little eyes'); one pair in most species, but two or even three pairs in others. A few large species have many eyes in clusters over the brain, mounted on tentacles, or spaced uniformly around the edge of the body. The ocelli can only distinguish the direction from which light is coming to enable the animals to avoid it. A few groups have statocysts – fluid-filled chambers containing a small, solid particle or, in a few groups, two. These statocysts are thought to function as balance and acceleration sensors, as they perform the same way in cnidarian medusae and in ctenophores. However, turbellarian statocysts have no sensory cilia, so the way they sense the movements and positions of solid particles is unknown. On the other hand, most have ciliated touch-sensor cells scattered over their bodies, especially on tentacles and around the edges. Specialized cells in pits or grooves on the head are most likely smell sensors. Planarians, a subgroup of seriates, are famous for their ability to regenerate if divided by cuts across their bodies. Experiments show that (in fragments that do not already have a head) a new head grows most quickly on those fragments which were originally located closest to the original head. This suggests the growth of a head is controlled by a chemical whose concentration diminishes throughout the organism, from head to tail. Many turbellarians clone themselves by transverse or longitudinal division, whilst others, reproduce by budding. The vast majority of turbellarians are hermaphrodites (they have both female and male reproductive cells) which fertilize eggs internally by copulation. Some of the larger aquatic species mate by penis fencing – a duel in which each tries to impregnate the other, and the loser adopts the female role of developing the eggs. In most species, "miniature adults" emerge when the eggs hatch, but a few large species produce plankton-like larvae. These parasites' name refers to the cavities in their holdfasts (Greek τρῆμα trêma 'hole'), which resemble suckers and anchor them within their hosts. The skin of all species is a syncitium, which is a layer of cells that shares a single external membrane. Trematodes are divided into two groups, Digenea and Aspidogastrea (also known as Aspodibothrea). These are often called flukes, as most have flat rhomboid shapes like that of a flounder (Old English flóc). There are about 11,000 species, more than all other platyhelminthes combined, and second only to roundworms among parasites on metazoans. Adults usually have two holdfasts: a ring around the mouth and a larger sucker midway along what would be the underside in a free-living flatworm. Although the name "Digeneans" means "two generations", most have very complex life cycles with up to seven stages, depending on what combinations of environments the early stages encounter – the most important factor being whether the eggs are deposited on land or in water. The intermediate stages transfer the parasites from one host to another. The definitive host in which adults develop is a land vertebrate; the earliest host of juvenile stages is usually a snail that may live on land or in water, whilst in many cases, a fish or arthropod is the second host. For example, the adjoining illustration shows the life cycle of the intestinal fluke metagonimus, which hatches in the intestine of a snail, then moves to a fish where it penetrates the body and encysts in the flesh, then migrating to the small intestine of a land animal that eats the fish raw, finally generating eggs that are excreted and ingested by snails, thereby completing the cycle. A similar life cycle occurs with Opisthorchis viverrini, which is found in South East Asia and can infect the liver of humans, causing Cholangiocarcinoma (bile duct cancer). Schistosomes, which cause the devastating tropical disease bilharzia, also belong to this group. Adults range between 0.2 mm (0.0079 in) and 6 mm (0.24 in) in length. Individual adult digeneans are of a single sex, and in some species slender females live in enclosed grooves that run along the bodies of the males, partially emerging to lay eggs. In all species the adults have complex reproductive systems, capable of producing between 10,000 and 100,000 times as many eggs as a free-living flatworm. In addition, the intermediate stages that live in snails reproduce asexually. Adults of different species infest different parts of the definitive host - for example the intestine, lungs, large blood vessels, and liver. The adults use a relatively large, muscular pharynx to ingest cells, cell fragments, mucus, body fluids or blood. In both the adult and snail-inhabiting stages, the external syncytium absorbs dissolved nutrients from the host. Adult digeneans can live without oxygen for long periods. Members of this small group have either a single divided sucker or a row of suckers that cover the underside. They infest the guts of bony or cartilaginous fish, turtles, or the body cavities of marine and freshwater bivalves and gastropods. Their eggs produce ciliated swimming larvae, and the life cycle has one or two hosts. Cercomeromorpha contains parasites attach themselves to their hosts by means of disks that bear crescent-shaped hooks. They are divided into the Monogenea and Cestoda groupings. Of about 1,100 species of monogeneans, most are external parasites that require particular host species - mainly fish, but in some cases amphibians or aquatic reptiles. However, a few are internal parasites. Adult monogeneans have large attachment organs at the rear, known as haptors (Greek ἅπτειν, haptein, means "catch"), which have suckers, clamps, and hooks. They often have flattened bodies. In some species, the pharynx secretes enzymes to digest the host's skin, allowing the parasite to feed on blood and cellular debris. Others graze externally on mucus and flakes of the hosts' skins. The name "Monogenea" is based on the fact that these parasites have only one nonlarval generation. These are often called tapeworms because of their flat, slender but very long bodies – the name "cestode" is derived from the Latin word cestus, which means 'tape'. The adults of all 3,400 cestode species are internal parasites. Cestodes have no mouths or guts, and the syncitial skin absorbs nutrients – mainly carbohydrates and amino acids – from the host, and also disguises it chemically to avoid attacks by the host's immune system. Shortage of carbohydrates in the host's diet stunts the growth of parasites and may even kill them. Their metabolisms generally use simple but inefficient chemical processes, compensating for this inefficiency by consuming large amounts of food relative to their physical size. In the majority of species, known as eucestodes ('true tapeworms'), the neck produces a chain of segments called proglottids via a process known as strobilation. As a result, the most mature proglottids are furthest from the scolex. Adults of Taenia saginata, which infests humans, can form proglottid chains over 20 metres (66 ft) long, although 4 metres (13 ft) is more typical. Each proglottid has both male and female reproductive organs. If the host's gut contains two or more adults of the same cestode species they generally fertilize each other, however, proglottids of the same worm can fertilize each other and even themselves. When the eggs are fully developed, the proglottids separate and are excreted by the host. The eucestode life cycle is less complex than that of digeneans, but varies depending on the species. For example: Members of the smaller group known as Cestodaria have no scolex, do not produce proglottids, and have body shapes similar to those of diageneans. Cestodarians parasitize fish and turtles. Classification and evolutionary relationships The relationships of Platyhelminthes to other Bilateria are shown in the phylogenetic tree: Acoelomorpha Deuterostomia Ecdysozoa Gnathifera Gastrotricha Platyhelminthes Mollusca Annelida The internal relationships of Platyhelminthes are shown below. The tree is not fully resolved. Catenulida Macrostomorpha Prorhynchida Polycladida Gnosonesimida Kalyptorhynchia Dalytyphloplanida Proseriata Prolecithophora Fecampiida Tricladida (planarians) Bothrioplanida (freshwater) Neodermata (flukes, tapeworms) The oldest confidently identified parasitic flatworm fossils are cestode eggs found in a Permian shark coprolite, but helminth hooks still attached to Devonian acanthodians and placoderms might also represent parasitic flatworms with simple life cycles. The oldest known free-living platyhelminth specimen is a fossil preserved in Eocene age Baltic amber and placed in the monotypic species Micropalaeosoma balticus, whilst the oldest subfossil specimens are schistosome eggs discovered in ancient Egyptian mummies. The Platyhelminthes have very few synapomorphies - distinguishing features that all Platyhelminthes (but no other animals) exhibit. This makes it difficult to work out their relationships with other groups of animals, as well as the relationships between different groups that are described as members of the Platyhelminthes. The "traditional" view before the 1990s was that Platyhelminthes formed the sister group to all the other bilaterians, which include, for instance, arthropods, molluscs, annelids and chordates. Since then, molecular phylogenetics, which aims to work out evolutionary "family trees" by comparing different organisms' biochemicals such as DNA, RNA and proteins, has radically changed scientists' view of evolutionary relationships between animals. Flatworms are now recognized as secondarily simplified bilaterians. Detailed morphological analyses of anatomical features in the mid-1980s, as well as molecular phylogenetics analyses since 2000 using different sections of DNA, agree that Acoelomorpha, consisting of Acoela (traditionally regarded as very simple "turbellarians") and Nemertodermatida (another small group previously classified as "turbellarians") are the sister group to all other bilaterians. However, a 2007 study concluded that Acoela and Nemertodermatida were two distinct groups of bilaterians. Xenoturbella, a bilaterian whose only well-defined organ is a statocyst, was originally classified as a "primitive turbellarian". Later studies suggested it may instead be a deuterostome, but more detailed molecular phylogenetics have led to its classification as sister-group to the Acoelomorpha. The Platyhelminthes excluding Acoelomorpha contain two main groups – Catenulida and Rhabditophora – both of which are generally agreed to be monophyletic (each contains all and only the descendants of an ancestor that is a member of the same group). Early molecular phylogenetics analyses of the Catenulida and Rhabditophora left uncertainties about whether these could be combined in a single monophyletic group; a study in 2008 concluded that they could, therefore Platyhelminthes could be redefined as Catenulida plus Rhabditophora, excluding the Acoelomorpha. Other molecular phylogenetics analyses agree the redefined Platyhelminthes are most closely related to Gastrotricha, and both are part of a grouping known as Platyzoa. Platyzoa are generally agreed to be at least closely related to the Lophotrochozoa, a superphylum that includes molluscs and annelid worms. The majority view is that Platyzoa are part of Lophotrochozoa, but a significant minority of researchers regard Platyzoa as a sister group of Lophotrochozoa. It has been agreed since 1985 that each of the wholly parasitic platyhelminth groups (Cestoda, Monogenea and Trematoda) is monophyletic, and that together these form a larger monophyletic grouping, the Neodermata, in which the adults of all members have syncytial skins. However, there is debate about whether the Cestoda and Monogenea can be combined as an intermediate monophyletic group, the Cercomeromorpha, within the Neodermata. It is generally agreed that the Neodermata are a sub-group a few levels down in the "family tree" of the Rhabditophora. Hence the traditional sub-phylum "Turbellaria" is paraphyletic, since it does not include the Neodermata although these are descendants of a sub-group of "turbellarians". Evolution An outline of the origins of the parasitic lifestyle has been proposed; epithelial feeding monopisthocotyleans on fish hosts are basal in the Neodermata and were the first shift to parasitism from free living ancestors. The next evolutionary step was a dietary change from epithelium to blood. The last common ancestor of Digenea + Cestoda was monogenean and most likely sanguinivorous. In several members of the order Rhabdocoela an endosymbiotic relationship with microalgae has evolved. Some species in the same order has also evolved kleptoplasty. The earliest known fossils confidently classified as tapeworms have been dated to 270 million years ago, after being found in coprolites (fossilised faeces) from an elasmobranch. Putative older fossils include a ribbon-shaped, bilaterally symmetrical organism named Rugosusivitta orthogonia from the Early Cambrian of China, brownish bodies on the bedding planes reported from the Late Ordovician (Katian) Vauréal Formation (Canada) by Knaust & Desrochers (2019), tentatively interpreted as turbellarians (though the authors cautioned that they might ultimately turn out to be fossils of acoelomorphs or nemerteans) and circlets of fossil hooks preserved with placoderm and acanthodian fossils from the Devonian of Latvia, at least some of which might represent parasitic monogeneans. Interaction with humans Cestodes (tapeworms) and digeneans (flukes) cause diseases in humans and their livestock, whilst monogeneans can cause serious losses of stocks in fish farms. Schistosomiasis, also known as bilharzia or snail fever, is the second-most devastating parasitic disease in tropical countries, behind malaria. The Carter Center estimated 200 million people in 74 countries are infected with the disease, and half the victims live in Africa. The condition has a low mortality rate, but usually presents as a chronic illness that can damage internal organs. It can impair the growth and cognitive development of children, increasing the risk of bladder cancer in adults. The disease is caused by several flukes of the genus Schistosoma, which can bore through human skin; those most at risk use infected bodies of water for recreation or laundry. In 2000, an estimated 45 million people were infected with the beef tapeworm Taenia saginata and 3 million with the pork tapeworm Taenia solium. Infection of the digestive system by adult tapeworms causes abdominal symptoms that, whilst unpleasant, are seldom disabling or life-threatening. However, neurocysticercosis resulting from penetration of T. solium larvae into the central nervous system is the major cause of acquired epilepsy worldwide. In 2000, about 39 million people were infected with trematodes (flukes) that naturally parasitize fish and crustaceans, but can pass to humans who eat raw or lightly cooked seafood. Infection of humans by the broad fish tapeworm Diphyllobothrium latum occasionally causes vitamin B12 deficiency and, in severe cases, megaloblastic anemia. The threat to humans in developed countries is rising as a result of social trends: the increase in organic farming, which uses manure and sewage sludge rather than artificial fertilizers, spreads parasites both directly and via the droppings of seagulls which feed on manure and sludge; the increasing popularity of raw or lightly cooked foods; imports of meat, seafood and salad vegetables from high-risk areas; and, as an underlying cause, reduced awareness of parasites compared with other public health issues such as pollution. In less-developed countries, inadequate sanitation and the use of human feces (night soil) as fertilizer or to enrich fish farm ponds continues to spread parasitic platyhelminths, whilst poorly designed water-supply and irrigation projects have provided additional channels for their spread. People in these countries usually cannot afford the cost of fuel required to cook food thoroughly enough to kill parasites. Controlling parasites that infect humans and livestock has become more difficult, as many species have become resistant to drugs that used to be effective, mainly for killing juveniles in meat. While poorer countries still struggle with unintentional infection, cases have been reported of intentional infection in the US by dieters who are desperate for rapid weight-loss. There is concern in northwest Europe (including the British Isles) regarding the possible proliferation of the New Zealand planarian Arthurdendyus triangulatus and the Australian flatworm Australoplana sanguinea, both of which prey on earthworms. A. triangulatus is thought to have reached Europe in containers of plants imported by botanical gardens. The planarian Platydemus manokwari has been deliberately released in an attempt at control of the giant African snail Achatina fulica which damages agricultural plants. It was first observed as an invasive species on Guam and was then released in the Philippines and Maldives. It has now spread to many islands in the Pacific and Caribbean and is now spreading across the Southern United States as well as southern and eastern Asia, including mainland China. It was initially claimed that P. manokwari severely reduced, and in places exterminated, A. fulica – achieving much greater success than most biological pest control programs, which generally aim for a low, stable population of the pest species. However, the decline of A. fulica is no longer thought to have been due to flatworm predation. These planarians are a serious threat to native snails and should never be used for biological control. A study in Argentina shows the potential for planarians such as Girardia anceps, Mesostoma ehrenbergii, and Bothromesostoma evelinae to reduce populations of the mosquito species Aedes aegypti and Culex pipiens. The experiment showed that G. anceps can prey on all instars of both mosquito species, yet maintain a steady predation rate over time. The ability of these flatworms to live in artificial containers demonstrated the potential of placing these species in popular mosquito breeding sites, which might reduce the amount of mosquito-borne disease. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Mars#cite_note-Bi2025-63] | [TOKENS: 11899] |
Contents Mars Mars is the fourth planet from the Sun. It is also known as the "Red Planet", for its orange-red appearance. Mars is a desert-like rocky planet with a tenuous atmosphere that is primarily carbon dioxide (CO2). At the average surface level the atmospheric pressure is a few thousandths of Earth's, atmospheric temperature ranges from −153 to 20 °C (−243 to 68 °F), and cosmic radiation is high. Mars retains some water, in the ground as well as thinly in the atmosphere, forming cirrus clouds, fog, frost, larger polar regions of permafrost and ice caps (with seasonal CO2 snow), but no bodies of liquid surface water. Its surface gravity is roughly a third of Earth's or double that of the Moon. Its diameter, 6,779 km (4,212 mi), is about half the Earth's, or twice the Moon's, and its surface area is the size of all the dry land of Earth. Fine dust is prevalent across the surface and the atmosphere, being picked up and spread at the low Martian gravity even by the weak wind of the tenuous atmosphere. The terrain of Mars roughly follows a north-south divide, the Martian dichotomy, with the northern hemisphere mainly consisting of relatively flat, low lying plains, and the southern hemisphere of cratered highlands. Geologically, the planet is fairly active with marsquakes trembling underneath the ground, but also hosts many enormous volcanoes that are extinct (the tallest is Olympus Mons, 21.9 km or 13.6 mi tall), as well as one of the largest canyons in the Solar System (Valles Marineris, 4,000 km or 2,500 mi long). Mars has two natural satellites that are small and irregular in shape: Phobos and Deimos. With a significant axial tilt of 25 degrees, Mars experiences seasons, like Earth (which has an axial tilt of 23.5 degrees). A Martian solar year is equal to 1.88 Earth years (687 Earth days), a Martian solar day (sol) is equal to 24.6 hours. Mars formed along with the other planets approximately 4.5 billion years ago. During the martian Noachian period (4.5 to 3.5 billion years ago), its surface was marked by meteor impacts, valley formation, erosion, the possible presence of water oceans and the loss of its magnetosphere. The Hesperian period (beginning 3.5 billion years ago and ending 3.3–2.9 billion years ago) was dominated by widespread volcanic activity and flooding that carved immense outflow channels. The Amazonian period, which continues to the present, is the currently dominating and remaining influence on geological processes. Because of Mars's geological history, the possibility of past or present life on Mars remains an area of active scientific investigation, with some possible traces needing further examination. Being visible with the naked eye in Earth's sky as a red wandering star, Mars has been observed throughout history, acquiring diverse associations in different cultures. In 1963 the first flight to Mars took place with Mars 1, but communication was lost en route. The first successful flyby exploration of Mars was conducted in 1965 with Mariner 4. In 1971 Mariner 9 entered orbit around Mars, being the first spacecraft to orbit any body other than the Moon, Sun or Earth; following in the same year were the first uncontrolled impact (Mars 2) and first successful landing (Mars 3) on Mars. Probes have been active on Mars continuously since 1997. At times, more than ten probes have simultaneously operated in orbit or on the surface, more than at any other planet beyond Earth. Mars is an often proposed target for future crewed exploration missions, though no such mission is currently planned. Natural history Scientists have theorized that during the Solar System's formation, Mars was created as the result of a random process of run-away accretion of material from the protoplanetary disk that orbited the Sun. Mars has many distinctive chemical features caused by its position in the Solar System. Elements with comparatively low boiling points, such as chlorine, phosphorus, and sulfur, are much more common on Mars than on Earth; these elements were probably pushed outward by the young Sun's energetic solar wind. After the formation of the planets, the inner Solar System may have been subjected to the so-called Late Heavy Bombardment. About 60% of the surface of Mars shows a record of impacts from that era, whereas much of the remaining surface is probably underlain by immense impact basins caused by those events. However, more recent modeling has disputed the existence of the Late Heavy Bombardment. There is evidence of an enormous impact basin in the Northern Hemisphere of Mars, spanning 10,600 by 8,500 kilometres (6,600 by 5,300 mi), or roughly four times the size of the Moon's South Pole–Aitken basin, which would be the largest impact basin yet discovered if confirmed. It has been hypothesized that the basin was formed when Mars was struck by a Pluto-sized body about four billion years ago. The event, thought to be the cause of the Martian hemispheric dichotomy, created the smooth Borealis basin that covers 40% of the planet. A 2023 study shows evidence, based on the orbital inclination of Deimos (a small moon of Mars), that Mars may once have had a ring system 3.5 billion years to 4 billion years ago. This ring system may have been formed from a moon, 20 times more massive than Phobos, orbiting Mars billions of years ago; and Phobos would be a remnant of that ring. Epochs: The geological history of Mars can be split into many periods, but the following are the three primary periods: Geological activity is still taking place on Mars. The Athabasca Valles is home to sheet-like lava flows created about 200 million years ago. Water flows in the grabens called the Cerberus Fossae occurred less than 20 million years ago, indicating equally recent volcanic intrusions. The Mars Reconnaissance Orbiter has captured images of avalanches. Physical characteristics Mars is approximately half the diameter of Earth or twice that of the Moon, with a surface area only slightly less than the total area of Earth's dry land. Mars is less dense than Earth, having about 15% of Earth's volume and 11% of Earth's mass, resulting in about 38% of Earth's surface gravity. Mars is the only presently known example of a desert planet, a rocky planet with a surface akin to that of Earth's deserts. The red-orange appearance of the Martian surface is caused by iron(III) oxide (nanophase Fe2O3) and the iron(III) oxide-hydroxide mineral goethite. It can look like butterscotch; other common surface colors include golden, brown, tan, and greenish, depending on the minerals present. Like Earth, Mars is differentiated into a dense metallic core overlaid by less dense rocky layers. The outermost layer is the crust, which is on average about 42–56 kilometres (26–35 mi) thick, with a minimum thickness of 6 kilometres (3.7 mi) in Isidis Planitia, and a maximum thickness of 117 kilometres (73 mi) in the southern Tharsis plateau. For comparison, Earth's crust averages 27.3 ± 4.8 km in thickness. The most abundant elements in the Martian crust are silicon, oxygen, iron, magnesium, aluminum, calcium, and potassium. Mars is confirmed to be seismically active; in 2019, it was reported that InSight had detected and recorded over 450 marsquakes and related events. Beneath the crust is a silicate mantle responsible for many of the tectonic and volcanic features on the planet's surface. The upper Martian mantle is a low-velocity zone, where the velocity of seismic waves is lower than surrounding depth intervals. The mantle appears to be rigid down to the depth of about 250 km, giving Mars a very thick lithosphere compared to Earth. Below this the mantle gradually becomes more ductile, and the seismic wave velocity starts to grow again. The Martian mantle does not appear to have a thermally insulating layer analogous to Earth's lower mantle; instead, below 1050 km in depth, it becomes mineralogically similar to Earth's transition zone. At the bottom of the mantle lies a basal liquid silicate layer approximately 150–180 km thick. The Martian mantle appears to be highly heterogenous, with dense fragments up to 4 km across, likely injected deep into the planet by colossal impacts ~4.5 billion years ago; high-frequency waves from eight marsquakes slowed as they passed these localized regions, and modeling indicates the heterogeneities are compositionally distinct debris preserved because Mars lacks plate tectonics and has a sluggishly convecting interior that prevents complete homogenization. Mars's iron and nickel core is at least partially molten, and may have a solid inner core. It is around half of Mars's radius, approximately 1650–1675 km, and is enriched in light elements such as sulfur, oxygen, carbon, and hydrogen. The temperature of the core is estimated to be 2000–2400 K, compared to 5400–6230 K for Earth's solid inner core. In 2025, based on data from the InSight lander, a group of researchers reported the detection of a solid inner core 613 kilometres (381 mi) ± 67 kilometres (42 mi) in radius. Mars is a terrestrial planet with a surface that consists of minerals containing silicon and oxygen, metals, and other elements that typically make up rock. The Martian surface is primarily composed of tholeiitic basalt, although parts are more silica-rich than typical basalt and may be similar to andesitic rocks on Earth, or silica glass. Regions of low albedo suggest concentrations of plagioclase feldspar, with northern low albedo regions displaying higher than normal concentrations of sheet silicates and high-silicon glass. Parts of the southern highlands include detectable amounts of high-calcium pyroxenes. Localized concentrations of hematite and olivine have been found. Much of the surface is deeply covered by finely grained iron(III) oxide dust. The Phoenix lander returned data showing Martian soil to be slightly alkaline and containing elements such as magnesium, sodium, potassium and chlorine. These nutrients are found in soils on Earth, and are necessary for plant growth. Experiments performed by the lander showed that the Martian soil has a basic pH of 7.7, and contains 0.6% perchlorate by weight, concentrations that are toxic to humans. Streaks are common across Mars and new ones appear frequently on steep slopes of craters, troughs, and valleys. The streaks are dark at first and get lighter with age. The streaks can start in a tiny area, then spread out for hundreds of metres. They have been seen to follow the edges of boulders and other obstacles in their path. The commonly accepted hypotheses include that they are dark underlying layers of soil revealed after avalanches of bright dust or dust devils. Several other explanations have been put forward, including those that involve water or even the growth of organisms. Environmental radiation levels on the surface are on average 0.64 millisieverts of radiation per day, and significantly less than the radiation of 1.84 millisieverts per day or 22 millirads per day during the flight to and from Mars. For comparison the radiation levels in low Earth orbit, where Earth's space stations orbit, are around 0.5 millisieverts of radiation per day. Hellas Planitia has the lowest surface radiation at about 0.342 millisieverts per day, featuring lava tubes southwest of Hadriacus Mons with potentially levels as low as 0.064 millisieverts per day, comparable to radiation levels during flights on Earth. Although Mars has no evidence of a structured global magnetic field, observations show that parts of the planet's crust have been magnetized, suggesting that alternating polarity reversals of its dipole field have occurred in the past. This paleomagnetism of magnetically susceptible minerals is similar to the alternating bands found on Earth's ocean floors. One hypothesis, published in 1999 and re-examined in October 2005 (with the help of the Mars Global Surveyor), is that these bands suggest plate tectonic activity on Mars four billion years ago, before the planetary dynamo ceased to function and the planet's magnetic field faded. Geography and features Although better remembered for mapping the Moon, Johann Heinrich von Mädler and Wilhelm Beer were the first areographers. They began by establishing that most of Mars's surface features were permanent and by more precisely determining the planet's rotation period. In 1840, Mädler combined ten years of observations and drew the first map of Mars. Features on Mars are named from a variety of sources. Albedo features are named for classical mythology. Craters larger than roughly 50 km are named for deceased scientists and writers and others who have contributed to the study of Mars. Smaller craters are named for towns and villages of the world with populations of less than 100,000. Large valleys are named for the word "Mars" or "star" in various languages; smaller valleys are named for rivers. Large albedo features retain many of the older names but are often updated to reflect new knowledge of the nature of the features. For example, Nix Olympica (the snows of Olympus) has become Olympus Mons (Mount Olympus). The surface of Mars as seen from Earth is divided into two kinds of areas, with differing albedo. The paler plains covered with dust and sand rich in reddish iron oxides were once thought of as Martian "continents" and given names like Arabia Terra (land of Arabia) or Amazonis Planitia (Amazonian plain). The dark features were thought to be seas, hence their names Mare Erythraeum, Mare Sirenum and Aurorae Sinus. The largest dark feature seen from Earth is Syrtis Major Planum. The permanent northern polar ice cap is named Planum Boreum. The southern cap is called Planum Australe. Mars's equator is defined by its rotation, but the location of its Prime Meridian was specified, as was Earth's (at Greenwich), by choice of an arbitrary point; Mädler and Beer selected a line for their first maps of Mars in 1830. After the spacecraft Mariner 9 provided extensive imagery of Mars in 1972, a small crater (later called Airy-0), located in the Sinus Meridiani ("Middle Bay" or "Meridian Bay"), was chosen by Merton E. Davies, Harold Masursky, and Gérard de Vaucouleurs for the definition of 0.0° longitude to coincide with the original selection. Because Mars has no oceans, and hence no "sea level", a zero-elevation surface had to be selected as a reference level; this is called the areoid of Mars, analogous to the terrestrial geoid. Zero altitude was defined by the height at which there is 610.5 Pa (6.105 mbar) of atmospheric pressure. This pressure corresponds to the triple point of water, and it is about 0.6% of the sea level surface pressure on Earth (0.006 atm). For mapping purposes, the United States Geological Survey divides the surface of Mars into thirty cartographic quadrangles, each named for a classical albedo feature it contains. In April 2023, The New York Times reported an updated global map of Mars based on images from the Hope spacecraft. A related, but much more detailed, global Mars map was released by NASA on 16 April 2023. The vast upland region Tharsis contains several massive volcanoes, which include the shield volcano Olympus Mons. The edifice is over 600 km (370 mi) wide. Because the mountain is so large, with complex structure at its edges, giving a definite height to it is difficult. Its local relief, from the foot of the cliffs which form its northwest margin to its peak, is over 21 km (13 mi), a little over twice the height of Mauna Kea as measured from its base on the ocean floor. The total elevation change from the plains of Amazonis Planitia, over 1,000 km (620 mi) to the northwest, to the summit approaches 26 km (16 mi), roughly three times the height of Mount Everest, which in comparison stands at just over 8.8 kilometres (5.5 mi). Consequently, Olympus Mons is either the tallest or second-tallest mountain in the Solar System; the only known mountain which might be taller is the Rheasilvia peak on the asteroid Vesta, at 20–25 km (12–16 mi). The dichotomy of Martian topography is striking: northern plains flattened by lava flows contrast with the southern highlands, pitted and cratered by ancient impacts. It is possible that, four billion years ago, the Northern Hemisphere of Mars was struck by an object one-tenth to two-thirds the size of Earth's Moon. If this is the case, the Northern Hemisphere of Mars would be the site of an impact crater 10,600 by 8,500 kilometres (6,600 by 5,300 mi) in size, or roughly the area of Europe, Asia, and Australia combined, surpassing Utopia Planitia and the Moon's South Pole–Aitken basin as the largest impact crater in the Solar System. Mars is scarred by 43,000 impact craters with a diameter of 5 kilometres (3.1 mi) or greater. The largest exposed crater is Hellas, which is 2,300 kilometres (1,400 mi) wide and 7,000 metres (23,000 ft) deep, and is a light albedo feature clearly visible from Earth. There are other notable impact features, such as Argyre, which is around 1,800 kilometres (1,100 mi) in diameter, and Isidis, which is around 1,500 kilometres (930 mi) in diameter. Due to the smaller mass and size of Mars, the probability of an object colliding with the planet is about half that of Earth. Mars is located closer to the asteroid belt, so it has an increased chance of being struck by materials from that source. Mars is more likely to be struck by short-period comets, i.e., those that lie within the orbit of Jupiter. Martian craters can[discuss] have a morphology that suggests the ground became wet after the meteor impact. The large canyon, Valles Marineris (Latin for 'Mariner Valleys, also known as Agathodaemon in the old canal maps), has a length of 4,000 kilometres (2,500 mi) and a depth of up to 7 kilometres (4.3 mi). The length of Valles Marineris is equivalent to the length of Europe and extends across one-fifth the circumference of Mars. By comparison, the Grand Canyon on Earth is only 446 kilometres (277 mi) long and nearly 2 kilometres (1.2 mi) deep. Valles Marineris was formed due to the swelling of the Tharsis area, which caused the crust in the area of Valles Marineris to collapse. In 2012, it was proposed that Valles Marineris is not just a graben, but a plate boundary where 150 kilometres (93 mi) of transverse motion has occurred, making Mars a planet with possibly a two-tectonic plate arrangement. Images from the Thermal Emission Imaging System (THEMIS) aboard NASA's Mars Odyssey orbiter have revealed seven possible cave entrances on the flanks of the volcano Arsia Mons. The caves, named after loved ones of their discoverers, are collectively known as the "seven sisters". Cave entrances measure from 100 to 252 metres (328 to 827 ft) wide and they are estimated to be at least 73 to 96 metres (240 to 315 ft) deep. Because light does not reach the floor of most of the caves, they may extend much deeper than these lower estimates and widen below the surface. "Dena" is the only exception; its floor is visible and was measured to be 130 metres (430 ft) deep. The interiors of these caverns may be protected from micrometeoroids, UV radiation, solar flares and high energy particles that bombard the planet's surface. Martian geysers (or CO2 jets) are putative sites of small gas and dust eruptions that occur in the south polar region of Mars during the spring thaw. "Dark dune spots" and "spiders" – or araneiforms – are the two most visible types of features ascribed to these eruptions. Similarly sized dust will settle from the thinner Martian atmosphere sooner than it would on Earth. For example, the dust suspended by the 2001 global dust storms on Mars only remained in the Martian atmosphere for 0.6 years, while the dust from Mount Pinatubo took about two years to settle. However, under current Martian conditions, the mass movements involved are generally much smaller than on Earth. Even the 2001 global dust storms on Mars moved only the equivalent of a very thin dust layer – about 3 μm thick if deposited with uniform thickness between 58° north and south of the equator. Dust deposition at the two rover sites has proceeded at a rate of about the thickness of a grain every 100 sols. Atmosphere Mars lost its magnetosphere 4 billion years ago, possibly because of numerous asteroid strikes, so the solar wind interacts directly with the Martian ionosphere, lowering the atmospheric density by stripping away atoms from the outer layer. Both Mars Global Surveyor and Mars Express have detected ionized atmospheric particles trailing off into space behind Mars, and this atmospheric loss is being studied by the MAVEN orbiter. Compared to Earth, the atmosphere of Mars is quite rarefied. Atmospheric pressure on the surface today ranges from a low of 30 Pa (0.0044 psi) on Olympus Mons to over 1,155 Pa (0.1675 psi) in Hellas Planitia, with a mean pressure at the surface level of 600 Pa (0.087 psi). The highest atmospheric density on Mars is equal to that found 35 kilometres (22 mi) above Earth's surface. The resulting mean surface pressure is only 0.6% of Earth's 101.3 kPa (14.69 psi). The scale height of the atmosphere is about 10.8 kilometres (6.7 mi), which is higher than Earth's 6 kilometres (3.7 mi), because the surface gravity of Mars is only about 38% of Earth's. The atmosphere of Mars consists of about 96% carbon dioxide, 1.93% argon and 1.89% nitrogen along with traces of oxygen and water. The atmosphere is quite dusty, containing particulates about 1.5 μm in diameter which give the Martian sky a tawny color when seen from the surface. It may take on a pink hue due to iron oxide particles suspended in it. Despite repeated detections of methane on Mars, there is no scientific consensus as to its origin. One suggestion is that methane exists on Mars and that its concentration fluctuates seasonally. The existence of methane could be produced by non-biological process such as serpentinization involving water, carbon dioxide, and the mineral olivine, which is known to be common on Mars, or by Martian life. Compared to Earth, its higher concentration of atmospheric CO2 and lower surface pressure may be why sound is attenuated more on Mars, where natural sources are rare apart from the wind. Using acoustic recordings collected by the Perseverance rover, researchers concluded that the speed of sound there is approximately 240 m/s for frequencies below 240 Hz, and 250 m/s for those above. Auroras have been detected on Mars. Because Mars lacks a global magnetic field, the types and distribution of auroras there differ from those on Earth; rather than being mostly restricted to polar regions as is the case on Earth, a Martian aurora can encompass the planet. In September 2017, NASA reported radiation levels on the surface of the planet Mars were temporarily doubled, and were associated with an aurora 25 times brighter than any observed earlier, due to a massive, and unexpected, solar storm in the middle of the month. Mars has seasons, alternating between its northern and southern hemispheres, similar to on Earth. Additionally the orbit of Mars has, compared to Earth's, a large eccentricity and approaches perihelion when it is summer in its southern hemisphere and winter in its northern, and aphelion when it is winter in its southern hemisphere and summer in its northern. As a result, the seasons in its southern hemisphere are more extreme and the seasons in its northern are milder than would otherwise be the case. The summer temperatures in the south can be warmer than the equivalent summer temperatures in the north by up to 30 °C (54 °F). Martian surface temperatures vary from lows of about −110 °C (−166 °F) to highs of up to 35 °C (95 °F) in equatorial summer. The wide range in temperatures is due to the thin atmosphere which cannot store much solar heat, the low atmospheric pressure (about 1% that of the atmosphere of Earth), and the low thermal inertia of Martian soil. The planet is 1.52 times as far from the Sun as Earth, resulting in just 43% of the amount of sunlight. Mars has the largest dust storms in the Solar System, reaching speeds of over 160 km/h (100 mph). These can vary from a storm over a small area, to gigantic storms that cover the entire planet. They tend to occur when Mars is closest to the Sun, and have been shown to increase global temperature. Seasons also produce dry ice covering polar ice caps. Hydrology While Mars contains water in larger amounts, most of it is dust covered water ice at the Martian polar ice caps. The volume of water ice in the south polar ice cap, if melted, would be enough to cover most of the surface of the planet with a depth of 11 metres (36 ft). Water in its liquid form cannot persist on the surface due to Mars's low atmospheric pressure, which is less than 1% that of Earth. Only at the lowest of elevations are the pressure and temperature high enough for liquid water to exist for short periods. Although little water is present in the atmosphere, there is enough to produce clouds of water ice and different cases of snow and frost, often mixed with snow of carbon dioxide dry ice. Landforms visible on Mars strongly suggest that liquid water has existed on the planet's surface. Huge linear swathes of scoured ground, known as outflow channels, cut across the surface in about 25 places. These are thought to be a record of erosion caused by the catastrophic release of water from subsurface aquifers, though some of these structures have been hypothesized to result from the action of glaciers or lava. One of the larger examples, Ma'adim Vallis, is 700 kilometres (430 mi) long, much greater than the Grand Canyon, with a width of 20 kilometres (12 mi) and a depth of 2 kilometres (1.2 mi) in places. It is thought to have been carved by flowing water early in Mars's history. The youngest of these channels is thought to have formed only a few million years ago. Elsewhere, particularly on the oldest areas of the Martian surface, finer-scale, dendritic networks of valleys are spread across significant proportions of the landscape. Features of these valleys and their distribution strongly imply that they were carved by runoff resulting from precipitation in early Mars history. Subsurface water flow and groundwater sapping may play important subsidiary roles in some networks, but precipitation was probably the root cause of the incision in almost all cases. Along craters and canyon walls, there are thousands of features that appear similar to terrestrial gullies. The gullies tend to be in the highlands of the Southern Hemisphere and face the Equator; all are poleward of 30° latitude. A number of authors have suggested that their formation process involves liquid water, probably from melting ice, although others have argued for formation mechanisms involving carbon dioxide frost or the movement of dry dust. No partially degraded gullies have formed by weathering and no superimposed impact craters have been observed, indicating that these are young features, possibly still active. Other geological features, such as deltas and alluvial fans preserved in craters, are further evidence for warmer, wetter conditions at an interval or intervals in earlier Mars history. Such conditions necessarily require the widespread presence of crater lakes across a large proportion of the surface, for which there is independent mineralogical, sedimentological and geomorphological evidence. Further evidence that liquid water once existed on the surface of Mars comes from the detection of specific minerals such as hematite and goethite, both of which sometimes form in the presence of water. The chemical signature of water vapor on Mars was first unequivocally demonstrated in 1963 by spectroscopy using an Earth-based telescope. In 2004, Opportunity detected the mineral jarosite. This forms only in the presence of acidic water, showing that water once existed on Mars. The Spirit rover found concentrated deposits of silica in 2007 that indicated wet conditions in the past, and in December 2011, the mineral gypsum, which also forms in the presence of water, was found on the surface by NASA's Mars rover Opportunity. It is estimated that the amount of water in the upper mantle of Mars, represented by hydroxyl ions contained within Martian minerals, is equal to or greater than that of Earth at 50–300 parts per million of water, which is enough to cover the entire planet to a depth of 200–1,000 metres (660–3,280 ft). On 18 March 2013, NASA reported evidence from instruments on the Curiosity rover of mineral hydration, likely hydrated calcium sulfate, in several rock samples including the broken fragments of "Tintina" rock and "Sutton Inlier" rock as well as in veins and nodules in other rocks like "Knorr" rock and "Wernicke" rock. Analysis using the rover's DAN instrument provided evidence of subsurface water, amounting to as much as 4% water content, down to a depth of 60 centimetres (24 in), during the rover's traverse from the Bradbury Landing site to the Yellowknife Bay area in the Glenelg terrain. In September 2015, NASA announced that they had found strong evidence of hydrated brine flows in recurring slope lineae, based on spectrometer readings of the darkened areas of slopes. These streaks flow downhill in Martian summer, when the temperature is above −23 °C, and freeze at lower temperatures. These observations supported earlier hypotheses, based on timing of formation and their rate of growth, that these dark streaks resulted from water flowing just below the surface. However, later work suggested that the lineae may be dry, granular flows instead, with at most a limited role for water in initiating the process. A definitive conclusion about the presence, extent, and role of liquid water on the Martian surface remains elusive. Researchers suspect much of the low northern plains of the planet were covered with an ocean hundreds of meters deep, though this theory remains controversial. In March 2015, scientists stated that such an ocean might have been the size of Earth's Arctic Ocean. This finding was derived from the ratio of protium to deuterium in the modern Martian atmosphere compared to that ratio on Earth. The amount of Martian deuterium (D/H = 9.3 ± 1.7 10−4) is five to seven times the amount on Earth (D/H = 1.56 10−4), suggesting that ancient Mars had significantly higher levels of water. Results from the Curiosity rover had previously found a high ratio of deuterium in Gale Crater, though not significantly high enough to suggest the former presence of an ocean. Other scientists caution that these results have not been confirmed, and point out that Martian climate models have not yet shown that the planet was warm enough in the past to support bodies of liquid water. Near the northern polar cap is the 81.4 kilometres (50.6 mi) wide Korolev Crater, which the Mars Express orbiter found to be filled with approximately 2,200 cubic kilometres (530 cu mi) of water ice. In November 2016, NASA reported finding a large amount of underground ice in the Utopia Planitia region. The volume of water detected has been estimated to be equivalent to the volume of water in Lake Superior (which is 12,100 cubic kilometers). During observations from 2018 through 2021, the ExoMars Trace Gas Orbiter spotted indications of water, probably subsurface ice, in the Valles Marineris canyon system. Orbital motion Mars's average distance from the Sun is roughly 230 million km (143 million mi), and its orbital period is 687 (Earth) days. The solar day (or sol) on Mars is only slightly longer than an Earth day: 24 hours, 39 minutes, and 35.244 seconds. A Martian year is equal to 1.8809 Earth years, or 1 year, 320 days, and 18.2 hours. The gravitational potential difference and thus the delta-v needed to transfer between Mars and Earth is the second lowest for Earth. The axial tilt of Mars is 25.19° relative to its orbital plane, which is similar to the axial tilt of Earth. As a result, Mars has seasons like Earth, though on Mars they are nearly twice as long because its orbital period is that much longer. In the present day, the orientation of the north pole of Mars is close to the star Deneb. Mars has a relatively pronounced orbital eccentricity of about 0.09; of the seven other planets in the Solar System, only Mercury has a larger orbital eccentricity. It is known that in the past, Mars has had a much more circular orbit. At one point, 1.35 million Earth years ago, Mars had an eccentricity of roughly 0.002, much less than that of Earth today. Mars's cycle of eccentricity is 96,000 Earth years compared to Earth's cycle of 100,000 years. Mars has its closest approach to Earth (opposition) in a synodic period of 779.94 days. It should not be confused with Mars conjunction, where the Earth and Mars are at opposite sides of the Solar System and form a straight line crossing the Sun. The average time between the successive oppositions of Mars, its synodic period, is 780 days; but the number of days between successive oppositions can range from 764 to 812. The distance at close approach varies between about 54 and 103 million km (34 and 64 million mi) due to the planets' elliptical orbits, which causes comparable variation in angular size. At their furthest Mars and Earth can be as far as 401 million km (249 million mi) apart. Mars comes into opposition from Earth every 2.1 years. The planets come into opposition near Mars's perihelion in 2003, 2018 and 2035, with the 2020 and 2033 events being particularly close to perihelic opposition. The mean apparent magnitude of Mars is +0.71 with a standard deviation of 1.05. Because the orbit of Mars is eccentric, the magnitude at opposition from the Sun can range from about −3.0 to −1.4. The minimum brightness is magnitude +1.86 when the planet is near aphelion and in conjunction with the Sun. At its brightest, Mars (along with Jupiter) is second only to Venus in apparent brightness. Mars usually appears distinctly yellow, orange, or red. When farthest away from Earth, it is more than seven times farther away than when it is closest. Mars is usually close enough for particularly good viewing once or twice at 15-year or 17-year intervals. Optical ground-based telescopes are typically limited to resolving features about 300 kilometres (190 mi) across when Earth and Mars are closest because of Earth's atmosphere. As Mars approaches opposition, it begins a period of retrograde motion, which means it will appear to move backwards in a looping curve with respect to the background stars. This retrograde motion lasts for about 72 days, and Mars reaches its peak apparent brightness in the middle of this interval. Moons Mars has two relatively small (compared to Earth's) natural moons, Phobos (about 22 km (14 mi) in diameter) and Deimos (about 12 km (7.5 mi) in diameter), which orbit at 9,376 km (5,826 mi) and 23,460 km (14,580 mi) around the planet. The origin of both moons is unclear, although a popular theory states that they were asteroids captured into Martian orbit. Both satellites were discovered in 1877 by Asaph Hall and were named after the characters Phobos (the deity of panic and fear) and Deimos (the deity of terror and dread), twins from Greek mythology who accompanied their father Ares, god of war, into battle. Mars was the Roman equivalent to Ares. In modern Greek, the planet retains its ancient name Ares (Aris: Άρης). From the surface of Mars, the motions of Phobos and Deimos appear different from that of the Earth's satellite, the Moon. Phobos rises in the west, sets in the east, and rises again in just 11 hours. Deimos, being only just outside synchronous orbit – where the orbital period would match the planet's period of rotation – rises as expected in the east, but slowly. Because the orbit of Phobos is below a synchronous altitude, tidal forces from Mars are gradually lowering its orbit. In about 50 million years, it could either crash into Mars's surface or break up into a ring structure around the planet. The origin of the two satellites is not well understood. Their low albedo and carbonaceous chondrite composition have been regarded as similar to asteroids, supporting a capture theory. The unstable orbit of Phobos would seem to point toward a relatively recent capture. But both have circular orbits near the equator, which is unusual for captured objects, and the required capture dynamics are complex. Accretion early in the history of Mars is plausible, but would not account for a composition resembling asteroids rather than Mars itself, if that is confirmed. Mars may have yet-undiscovered moons, smaller than 50 to 100 metres (160 to 330 ft) in diameter, and a dust ring is predicted to exist between Phobos and Deimos. A third possibility for their origin as satellites of Mars is the involvement of a third body or a type of impact disruption. More-recent lines of evidence for Phobos having a highly porous interior, and suggesting a composition containing mainly phyllosilicates and other minerals known from Mars, point toward an origin of Phobos from material ejected by an impact on Mars that reaccreted in Martian orbit, similar to the prevailing theory for the origin of Earth's satellite. Although the visible and near-infrared (VNIR) spectra of the moons of Mars resemble those of outer-belt asteroids, the thermal infrared spectra of Phobos are reported to be inconsistent with chondrites of any class. It is also possible that Phobos and Deimos were fragments of an older moon, formed by debris from a large impact on Mars, and then destroyed by a more recent impact upon the satellite. More recently, a study conducted by a team of researchers from multiple countries suggests that a lost moon, at least fifteen times the size of Phobos, may have existed in the past. By analyzing rocks which point to tidal processes on the planet, it is possible that these tides may have been regulated by a past moon. Human observations and exploration The history of observations of Mars is marked by oppositions of Mars when the planet is closest to Earth and hence is most easily visible, which occur every couple of years. Even more notable are the perihelic oppositions of Mars, which are distinguished because Mars is close to perihelion, making it even closer to Earth. The ancient Sumerians named Mars Nergal, the god of war and plague. During Sumerian times, Nergal was a minor deity of little significance, but, during later times, his main cult center was the city of Nineveh. In Mesopotamian texts, Mars is referred to as the "star of judgement of the fate of the dead". The existence of Mars as a wandering object in the night sky was also recorded by the ancient Egyptian astronomers and, by 1534 BCE, they were familiar with the retrograde motion of the planet. By the period of the Neo-Babylonian Empire, the Babylonian astronomers were making regular records of the positions of the planets and systematic observations of their behavior. For Mars, they knew that the planet made 37 synodic periods, or 42 circuits of the zodiac, every 79 years. They invented arithmetic methods for making minor corrections to the predicted positions of the planets. In Ancient Greece, the planet was known as Πυρόεις. Commonly, the Greek name for the planet now referred to as Mars, was Ares. It was the Romans who named the planet Mars, for their god of war, often represented by the sword and shield of the planet's namesake. In the fourth century BCE, Aristotle noted that Mars disappeared behind the Moon during an occultation, indicating that the planet was farther away. Ptolemy, a Greek living in Alexandria, attempted to address the problem of the orbital motion of Mars. Ptolemy's model and his collective work on astronomy was presented in the multi-volume collection later called the Almagest (from the Arabic for "greatest"), which became the authoritative treatise on Western astronomy for the next fourteen centuries. Literature from ancient China confirms that Mars was known by Chinese astronomers by no later than the fourth century BCE. In the East Asian cultures, Mars is traditionally referred to as the "fire star" (火星) based on the Wuxing system. In 1609 Johannes Kepler published a 10 year study of Martian orbit, using the diurnal parallax of Mars, measured by Tycho Brahe, to make a preliminary calculation of the relative distance to the planet. From Brahe's observations of Mars, Kepler deduced that the planet orbited the Sun not in a circle, but in an ellipse. Moreover, Kepler showed that Mars sped up as it approached the Sun and slowed down as it moved farther away, in a manner that later physicists would explain as a consequence of the conservation of angular momentum.: 433–437 In 1610 the first use of a telescope for astronomical observation, including Mars, was performed by Italian astronomer Galileo Galilei. With the telescope the diurnal parallax of Mars was again measured in an effort to determine the Sun-Earth distance. This was first performed by Giovanni Domenico Cassini in 1672. The early parallax measurements were hampered by the quality of the instruments. The only occultation of Mars by Venus observed was that of 13 October 1590, seen by Michael Maestlin at Heidelberg. By the 19th century, the resolution of telescopes reached a level sufficient for surface features to be identified. On 5 September 1877, a perihelic opposition to Mars occurred. The Italian astronomer Giovanni Schiaparelli used a 22-centimetre (8.7 in) telescope in Milan to help produce the first detailed map of Mars. These maps notably contained features he called canali, which, with the possible exception of the natural canyon Valles Marineris, were later shown to be an optical illusion. These canali were supposedly long, straight lines on the surface of Mars, to which he gave names of famous rivers on Earth. His term, which means "channels" or "grooves", was popularly mistranslated in English as "canals". Influenced by the observations, the orientalist Percival Lowell founded an observatory which had 30- and 45-centimetre (12- and 18-in) telescopes. The observatory was used for the exploration of Mars during the last good opportunity in 1894, and the following less favorable oppositions. He published several books on Mars and life on the planet, which had a great influence on the public. The canali were independently observed by other astronomers, like Henri Joseph Perrotin and Louis Thollon in Nice, using one of the largest telescopes of that time. The seasonal changes (consisting of the diminishing of the polar caps and the dark areas formed during Martian summers) in combination with the canals led to speculation about life on Mars, and it was a long-held belief that Mars contained vast seas and vegetation. As bigger telescopes were used, fewer long, straight canali were observed. During observations in 1909 by Antoniadi with an 84-centimetre (33 in) telescope, irregular patterns were observed, but no canali were seen. The first spacecraft from Earth to visit Mars was Mars 1 of the Soviet Union, which flew by in 1963, but contact was lost en route. NASA's Mariner 4 followed and became the first spacecraft to successfully transmit from Mars; launched on 28 November 1964, it made its closest approach to the planet on 15 July 1965. Mariner 4 detected the weak Martian radiation belt, measured at about 0.1% that of Earth, and captured the first images of another planet from deep space. Once spacecraft visited the planet during the 1960s and 1970s, many previous concepts of Mars were radically broken. After the results of the Viking life-detection experiments, the hypothesis of a dead planet was generally accepted. The data from Mariner 9 and Viking allowed better maps of Mars to be made. Until 1997 and after Viking 1 shut down in 1982, Mars was only visited by three unsuccessful probes, two flying past without contact (Phobos 1, 1988; Mars Observer, 1993), and one (Phobos 2 1989) malfunctioning in orbit before reaching its destination Phobos. In 1997 Mars Pathfinder became the first successful rover mission beyond the Moon and started together with Mars Global Surveyor (operated until late 2006) an uninterrupted active robotic presence at Mars that has lasted until today. It produced complete, extremely detailed maps of the Martian topography, magnetic field and surface minerals. Starting with these missions a range of new improved crewless spacecraft, including orbiters, landers, and rovers, have been sent to Mars, with successful missions by the NASA (United States), Jaxa (Japan), ESA, United Kingdom, ISRO (India), Roscosmos (Russia), the United Arab Emirates, and CNSA (China) to study the planet's surface, climate, and geology, uncovering the different elements of the history and dynamic of the hydrosphere of Mars and possible traces of ancient life. As of 2023[update], Mars is host to ten functioning spacecraft. Eight are in orbit: 2001 Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, MAVEN, ExoMars Trace Gas Orbiter, the Hope orbiter, and the Tianwen-1 orbiter. Another two are on the surface: the Mars Science Laboratory Curiosity rover and the Perseverance rover. Collected maps are available online at websites including Google Mars. NASA provides two online tools: Mars Trek, which provides visualizations of the planet using data from 50 years of exploration, and Experience Curiosity, which simulates traveling on Mars in 3-D with Curiosity. Planned missions to Mars include: As of February 2024[update], debris from these types of missions has reached over seven tons. Most of it consists of crashed and inactive spacecraft as well as discarded components. In April 2024, NASA selected several companies to begin studies on providing commercial services to further enable robotic science on Mars. Key areas include establishing telecommunications, payload delivery and surface imaging. Habitability and habitation During the late 19th century, it was widely accepted in the astronomical community that Mars had life-supporting qualities, including the presence of oxygen and water. However, in 1894 W. W. Campbell at Lick Observatory observed the planet and found that "if water vapor or oxygen occur in the atmosphere of Mars it is in quantities too small to be detected by spectroscopes then available". That observation contradicted many of the measurements of the time and was not widely accepted. Campbell and V. M. Slipher repeated the study in 1909 using better instruments, but with the same results. It was not until the findings were confirmed by W. S. Adams in 1925 that the myth of the Earth-like habitability of Mars was finally broken. However, even in the 1960s, articles were published on Martian biology, putting aside explanations other than life for the seasonal changes on Mars. The current understanding of planetary habitability – the ability of a world to develop environmental conditions favorable to the emergence of life – favors planets that have liquid water on their surface. Most often this requires the orbit of a planet to lie within the habitable zone, which for the Sun is estimated to extend from within the orbit of Earth to about that of Mars. During perihelion, Mars dips inside this region, but Mars's thin (low-pressure) atmosphere prevents liquid water from existing over large regions for extended periods. The past flow of liquid water demonstrates the planet's potential for habitability. Recent evidence has suggested that any water on the Martian surface may have been too salty and acidic to support regular terrestrial life. The environmental conditions on Mars are a challenge to sustaining organic life: the planet has little heat transfer across its surface, it has poor insulation against bombardment by the solar wind due to the absence of a magnetosphere and has insufficient atmospheric pressure to retain water in a liquid form (water instead sublimes to a gaseous state). Mars is nearly, or perhaps totally, geologically dead; the end of volcanic activity has apparently stopped the recycling of chemicals and minerals between the surface and interior of the planet. Evidence suggests that the planet was once significantly more habitable than it is today, but whether living organisms ever existed there remains unknown. The Viking probes of the mid-1970s carried experiments designed to detect microorganisms in Martian soil at their respective landing sites and had positive results, including a temporary increase in CO2 production on exposure to water and nutrients. This sign of life was later disputed by scientists, resulting in a continuing debate, with NASA scientist Gilbert Levin asserting that Viking may have found life. A 2014 analysis of Martian meteorite EETA79001 found chlorate, perchlorate, and nitrate ions in sufficiently high concentrations to suggest that they are widespread on Mars. UV and X-ray radiation would turn chlorate and perchlorate ions into other, highly reactive oxychlorines, indicating that any organic molecules would have to be buried under the surface to survive. Small quantities of methane and formaldehyde detected by Mars orbiters are both claimed to be possible evidence for life, as these chemical compounds would quickly break down in the Martian atmosphere. Alternatively, these compounds may instead be replenished by volcanic or other geological means, such as serpentinite. Impact glass, formed by the impact of meteors, which on Earth can preserve signs of life, has also been found on the surface of the impact craters on Mars. Likewise, the glass in impact craters on Mars could have preserved signs of life, if life existed at the site. The Cheyava Falls rock discovered on Mars in June 2024 has been designated by NASA as a "potential biosignature" and was core sampled by the Perseverance rover for possible return to Earth and further examination. Although highly intriguing, no definitive final determination on a biological or abiotic origin of this rock can be made with the data currently available. Several plans for a human mission to Mars have been proposed, but none have come to fruition. The NASA Authorization Act of 2017 directed NASA to study the feasibility of a crewed Mars mission in the early 2030s; the resulting report concluded that this would be unfeasible. In addition, in 2021, China was planning to send a crewed Mars mission in 2033. Privately held companies such as SpaceX have also proposed plans to send humans to Mars, with the eventual goal to settle on the planet. As of 2024, SpaceX has proceeded with the development of the Starship launch vehicle with the goal of Mars colonization. In plans shared with the company in April 2024, Elon Musk envisions the beginning of a Mars colony within the next twenty years. This would be enabled by the planned mass manufacturing of Starship and initially sustained by resupply from Earth, and in situ resource utilization on Mars, until the Mars colony reaches full self sustainability. Any future human mission to Mars will likely take place within the optimal Mars launch window, which occurs every 26 months. The moon Phobos has been proposed as an anchor point for a space elevator. Besides national space agencies and space companies, groups such as the Mars Society and The Planetary Society advocate for human missions to Mars. In culture Mars is named after the Roman god of war (Greek Ares), but was also associated with the demi-god Heracles (Roman Hercules) by ancient Greek astronomers, as detailed by Aristotle. This association between Mars and war dates back at least to Babylonian astronomy, in which the planet was named for the god Nergal, deity of war and destruction. It persisted into modern times, as exemplified by Gustav Holst's orchestral suite The Planets, whose famous first movement labels Mars "The Bringer of War". The planet's symbol, a circle with a spear pointing out to the upper right, is also used as a symbol for the male gender. The symbol dates from at least the 11th century, though a possible predecessor has been found in the Greek Oxyrhynchus Papyri. The idea that Mars was populated by intelligent Martians became widespread in the late 19th century. Schiaparelli's "canali" observations combined with Percival Lowell's books on the subject put forward the standard notion of a planet that was a drying, cooling, dying world with ancient civilizations constructing irrigation works. Many other observations and proclamations by notable personalities added to what has been termed "Mars Fever". In the present day, high-resolution mapping of the surface of Mars has revealed no artifacts of habitation, but pseudoscientific speculation about intelligent life on Mars still continues. Reminiscent of the canali observations, these speculations are based on small scale features perceived in the spacecraft images, such as "pyramids" and the "Face on Mars". In his book Cosmos, planetary astronomer Carl Sagan wrote: "Mars has become a kind of mythic arena onto which we have projected our Earthly hopes and fears." The depiction of Mars in fiction has been stimulated by its dramatic red color and by nineteenth-century scientific speculations that its surface conditions might support not just life but intelligent life. This gave way to many science fiction stories involving these concepts, such as H. G. Wells's The War of the Worlds, in which Martians seek to escape their dying planet by invading Earth; Ray Bradbury's The Martian Chronicles, in which human explorers accidentally destroy a Martian civilization; as well as Edgar Rice Burroughs's series Barsoom, C. S. Lewis's novel Out of the Silent Planet (1938), and a number of Robert A. Heinlein stories before the mid-sixties. Since then, depictions of Martians have also extended to animation. A comic figure of an intelligent Martian, Marvin the Martian, appeared in Haredevil Hare (1948) as a character in the Looney Tunes animated cartoons of Warner Brothers, and has continued as part of popular culture to the present. After the Mariner and Viking spacecraft had returned pictures of Mars as a lifeless and canal-less world, these ideas about Mars were abandoned; for many science-fiction authors, the new discoveries initially seemed like a constraint, but eventually the post-Viking knowledge of Mars became itself a source of inspiration for works like Kim Stanley Robinson's Mars trilogy. See also Notes References Further reading External links Solar System → Local Interstellar Cloud → Local Bubble → Gould Belt → Orion Arm → Milky Way → Milky Way subgroup → Local Group → Local Sheet → Local Volume → Virgo Supercluster → Laniakea Supercluster → Pisces–Cetus Supercluster Complex → Local Hole → Observable universe → UniverseEach arrow (→) may be read as "within" or "part of". |
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[SOURCE: https://en.wikipedia.org/wiki/Comedy] | [TOKENS: 3924] |
Contents Comedy Comedy is a genre of dramatic works intended to be humorous or amusing by inducing laughter, especially in theatre, film, stand-up comedy, television, radio, books, or any other entertainment medium. Origins Comedy originated in ancient Greece: in Athenian democracy, the public opinion of voters was influenced by political satire performed by comic poets in theaters. The theatrical genre of Greek comedy can be described as a dramatic performance pitting two groups, ages, genders, or societies against each other in an amusing agon or conflict. Northrop Frye depicted these two opposing sides as a "Society of Youth" and a "Society of the Old". A revised view characterizes the essential agon of comedy as a struggle between a relatively powerless youth and the societal conventions posing obstacles to his hopes. In this struggle, the youth then becomes constrained by his lack of social authority, and is left with little choice but to resort to ruses which engender dramatic irony, which provokes laughter. Varieties Satire and political satire use comedy to portray people or social institutions as ridiculous or corrupt, thus alienating their audience from the object of their humor. Parody subverts popular genres and forms, critiquing those forms without necessarily condemning them. Other forms of comedy include screwball comedy, which derives its humor largely from bizarre, surprising (and improbable) situations or characters, and black comedy, which is characterized by a form of humor that includes darker aspects of human behavior or human nature. Similarly scatological humor, sexual humor, and race humor create comedy by violating social conventions or taboos in comic ways, which can often be taken as offensive by the subjects of the joke. A comedy of manners typically takes as its subject a particular part of society (usually upper-class society) and uses humor to parody or satirize the behavior and mannerisms of its members. Romantic comedy is a popular genre that depicts burgeoning romance in humorous terms and focuses on the foibles of those who are falling in love. Etymology Dean Rubin says the word "comedy" is derived from the Classical Greek κωμῳδία kōmōidía, which is a compound of κῶμος kômos "revel" and ᾠδή ōidḗ "singing, ode". The adjective "comic" (Greek κωμικός kōmikós), which strictly means that which relates to comedy is, in modern usage, generally confined to the sense of "laughter-provoking". Of this, the word came into modern usage through the Latin comoedia and Italian commedia and has, over time, passed through various shades of meaning. The Greeks and Romans confined their use of the word "comedy" to descriptions of stage-plays with happy endings. Aristotle defined comedy as an imitation of men worse than the average (where tragedy was an imitation of men better than the average). However, the characters portrayed in comedies were not worse than average in every way, only insofar as they are Ridiculous, which is a species of the Ugly. The Ridiculous may be defined as a mistake or deformity not productive of pain or harm to others; the mask, for instance, that excites laughter is something ugly and distorted without causing pain. In the Middle Ages, the term expanded to include narrative poems with happy endings. It is in this sense that Dante used the term in the title of his poem, La Commedia. As time progressed, the word came more and more to be associated with any sort of performance intended to cause laughter. During the Middle Ages, the term "comedy" became synonymous with satire, and later with humour in general. Aristotle's Poetics was translated into Arabic in the medieval Islamic world, where it was elaborated upon by Arabic writers and Islamic philosophers, such as Abu Bishr, and his pupils Al-Farabi, Avicenna, and Averroes. They disassociated comedy from Greek dramatic representation and instead identified it with Arabic poetic themes and forms, such as hija (satirical poetry). They viewed comedy as simply the "art of reprehension", and made no reference to light and cheerful events, or to the troubling beginnings and happy endings associated with classical Greek comedy. After the Latin translations of the 12th century, the term "comedy" gained a more general meaning in medieval literature. In the late 20th century, many scholars preferred to use the term laughter to refer to the whole gamut of the comic, in order to avoid the use of ambiguous and problematically defined genres such as the grotesque, irony, and satire. History Starting from 425 BCE, Aristophanes, a comic play and satirical author of the Ancient Greek theater, wrote 40 comedies, 11 of which survive. Aristophanes developed his type of comedy from the earlier satyr plays, which were often highly obscene. The only surviving examples of the satyr plays are by Euripides, which are much later examples and not representative of the genre. In ancient Greece, comedy originated in bawdy and ribald songs or recitations apropos of phallic processions and fertility festivals or gatherings. Around 335 BCE, Aristotle, in his work Poetics, stated that comedy originated in phallic processions and the light treatment of the otherwise base and ugly. He also adds that the origins of comedy are obscure because it was not treated seriously from its inception. However, comedy had its own Muse: Thalia.[citation needed] Aristotle taught that comedy was generally positive for society, since it brings forth happiness, which for Aristotle was the ideal state, the final goal in any activity. For Aristotle, a comedy did not need to involve sexual humor. A comedy is about the fortunate rise of a sympathetic character. Aristotle divides comedy into three categories or subgenres: farce, romantic comedy, and satire. On the other hand, Plato taught that comedy is a destruction to the self. He believed that it produces an emotion that overrides rational self-control and learning. In The Republic, he says that the guardians of the state should avoid laughter, "for ordinarily when one abandons himself to violent laughter, his condition provokes a violent reaction." Plato says comedy should be tightly controlled if one wants to achieve the ideal state. Also in Poetics, Aristotle defined comedy as one of the original four genres of literature. The other three genres are tragedy, epic poetry, and lyric poetry. Literature, in general, is defined by Aristotle as a mimesis, or imitation of life. Comedy is the third form of literature, being the most divorced from a true mimesis. Tragedy is the truest mimesis, followed by epic poetry, comedy, and lyric poetry. The genre of comedy is defined by a certain pattern according to Aristotle's definition. Comedies begin with low or base characters seeking insignificant aims and end with some accomplishment of the aims which either lightens the initial baseness or reveals the insignificance of the aims. "Comedy", in its Elizabethan usage, had a very different meaning from modern comedy. A Shakespearean comedy is one that has a happy ending, usually involving marriages between the unmarried characters, and a tone and style that is more light-hearted than Shakespeare's other plays. The Punch and Judy show has roots in the 16th-century Italian commedia dell'arte. The figure of Punch derives from the Neapolitan stock character of Pulcinella. The figure who later became Mr. Punch made his first recorded appearance in England in 1662. Punch and Judy are performed in the spirit of outrageous comedy — often provoking shocked laughter — and are dominated by the anarchic clowning of Mr. Punch. Appearing at a significant period in British history, professor Glyn Edwards states: "[Pulcinella] went down particularly well with Restoration British audiences, fun-starved after years of Puritanism. We soon changed Punch's name, transformed him from a marionette to a hand puppet, and he became, really, a spirit of Britain — a subversive maverick who defies authority, a kind of puppet equivalent to our political cartoons." In early 19th century England, pantomime acquired its present form which includes slapstick comedy and featured the first mainstream clown Joseph Grimaldi, while comedy routines also featured heavily in British music hall theatre which became popular in the 1850s. British comedians who honed their skills in music hall sketches include Charlie Chaplin, Stan Laurel and Dan Leno. English music hall comedian and theatre impresario Fred Karno developed a form of sketch comedy without dialogue in the 1890s, and Chaplin and Laurel were among the comedians who worked for his company. Karno was a pioneer of slapstick, and in his biography, Laurel stated, "Fred Karno didn't teach Charlie [Chaplin] and me all we know about comedy. He just taught us most of it". Film producer Hal Roach stated: "Fred Karno is not only a genius, he is the man who originated slapstick comedy. We in Hollywood owe much to him." American vaudeville emerged in the 1880s and remained popular until the 1930s, and featured comedians such as W. C. Fields, Buster Keaton and the Marx Brothers. Surreal humour (also known as 'absurdist humour'), or 'surreal comedy', is a form of humour predicated on deliberate violations of causal reasoning, producing events and behaviours that are obviously illogical. Constructions of surreal humour tend to involve bizarre juxtapositions, incongruity, non-sequiturs, irrational or absurd situations and expressions of nonsense. The humour arises from a subversion of audience's expectations, so that amusement is founded on unpredictability, separate from a logical analysis of the situation. The humour derived gets its appeal from the ridiculousness and unlikeliness of the situation. The genre has roots in Surrealism in the arts. Surreal humour is the effect of illogic and absurdity being used for humorous effect. Under such premises, people can identify precursors and early examples of surreal humour at least since the 19th century, such as Lewis Carroll's Alice's Adventures in Wonderland and Through the Looking-Glass, which both use illogic and absurdity (hookah-smoking caterpillars, croquet matches using live flamingos as mallets, etc.) for humorous effect. Many of Edward Lear's children stories and poems contain nonsense and are basically surreal in approach. For example, The Story of the Four Little Children Who Went Round the World (1871) is filled with contradictory statements and odd images intended to provoke amusement, such as the following: After a time they saw some land at a distance; and when they came to it, they found it was an island made of water quite surrounded by earth. Besides that, it was bordered by evanescent isthmuses with a great Gulf-stream running about all over it, so that it was perfectly beautiful, and contained only a single tree, 503 feet high. In the early 20th century, several avant-garde movements, including the dadaists, surrealists, and futurists, began to argue for an art that was random, jarring and illogical. The goals of these movements were in some sense serious, and they were committed to undermining the solemnity and self-satisfaction of the contemporary artistic establishment. As a result, much of their art was intentionally amusing. A famous example is Marcel Duchamp's Fountain (1917), an inverted urinal signed "R. Mutt". This became one of the most famous and influential pieces of art in history, and one of the earliest examples of the found object movement. It is also a joke, relying on the inversion of the item's function as expressed by its title as well as its incongruous presence in an art exhibition. The advent of cinema in the late 19th century, and later radio and television in the 20th century broadened the access of comedians to the general public. Charlie Chaplin, through silent film, became one of the best-known faces on Earth. The silent tradition lived on well into the late 20th century through mime artists like Marcel Marceau, and the slapstick comedy of artists like Rowan Atkinson (as Mr. Bean). The tradition of the circus clown also continued, with such as Bozo the Clown in the United States and Oleg Popov in Russia. Radio provided new possibilities — with Britain producing the influential surreal humour of the Goon Show after the Second World War. The Goons' influence spread to the American radio and recording troupe the Firesign Theatre. American cinema has produced a great number of globally renowned comedy artists, from Laurel and Hardy, the Three Stooges, Abbott and Costello, Dean Martin and Jerry Lewis, Bob Hope and Phyllis Diller during the mid-20th century, to performers like George Carlin, Bill Cosby, Joan Rivers, Robin Williams, and Eddie Murphy toward the end of the century. Hollywood attracted many international talents like the British comics Peter Sellers, Dudley Moore and Sacha Baron Cohen, Canadian comics Dan Aykroyd, Jim Carrey, and Mike Myers, and the Australian comedian Paul Hogan, famous for Crocodile Dundee. Other centres of creative comic activity have been the cinema of Hong Kong, Bollywood, and French farce. American television has also been an influential force in world comedy: with American series like M*A*S*H, Seinfeld and The Simpsons achieving large followings around the world. British television comedy also remains influential, with quintessential works including Fawlty Towers, Monty Python, Dad's Army, Blackadder, and The Office. Australian satirist Barry Humphries, whose comic creations include the housewife and "gigastar" Dame Edna Everage, for his delivery of Dadaist and absurdist humour to millions, was described by biographer Anne Pender in 2010 as not only "the most significant theatrical figure of our time ... [but] the most significant comedian to emerge since Charlie Chaplin". Indian classical drama sometimes contained elements of satire and parody, with well-known comedic plays including Mṛcchakatika by Shudraka and Ratnavali. By 200 BC, Bharata Muni's Natya Shastra defined humour (hāsyam) as one of the nine nava rasas, or principle rasas (emotional responses), which can be inspired in the audience by bhavas, the imitations of emotions that the actors perform. In this case, the rasa of humour was associated with the bhava of laughter/mirth (hasya). Similarly to America, Indian cinema would exert a large influence on the humour of South Asia. There are many traditions of Chinese comedy. Xiangsheng, also known as crosstalk, is usually a rapid dialogue between two people which emphasizes word play and allusions. Japan has a long tradition of verbal comedy, most notably Rakugo, a form of comic storytelling in which a single seated performer narrates humorous tales using dialogue, vocal variation, and minimal props.It was developed from medieval setsuwa literature and Buddhist preaching and became a popular professional performance art during the Edo period. Studies on comic theory The phenomena connected with laughter and that which provokes it have been carefully investigated by psychologists. They agree the predominant characteristics are incongruity or contrast in the object and shock or emotional seizure on the part of the subject. It has also been held that the feeling of superiority is an essential factor: thus Thomas Hobbes speaks of laughter as a "sudden glory". Modern investigators have paid much attention to the origin both of laughter and of smiling, as well as the development of the "play instinct" and its emotional expression. George Meredith said that "One excellent test of the civilization of a country ... I take to be the flourishing of the Comic idea and Comedy, and the test of true Comedy is that it shall awaken thoughtful laughter." Laughter is said to be the cure for being sick. Studies show that people who laugh more often get sick less. American literary theorist Kenneth Burke writes that the "comic frame" in rhetoric is "neither wholly euphemistic, nor wholly debunking—hence it provides the charitable attitude towards people that is required for purposes of persuasion and co-operation, but at the same time maintains our shrewdness concerning the simplicities of 'cashing in.'" The purpose of the comic frame is to satirize a given circumstance and promote change by doing so. The comic frame makes fun of situations and people, while simultaneously provoking thought. The comic frame does not aim to vilify in its analysis, but rather, rebuke the stupidity and foolery of those involved in the circumstances. For example, on The Daily Show, Jon Stewart uses the "comic frame" to intervene in political arguments, often offering crude humor in sudden contrast to serious news. In a segment on President Obama's trip to China, Stewart remarks on America's debt to the Chinese government while also having a weak relationship with the country. After depicting this dismal situation, Stewart shifts to speak directly to President Obama, calling upon him to "shine that turd up." For Stewart and his audience, introducing coarse language into what is otherwise a serious commentary on the state of foreign relations serves to frame the segment comically, creating a serious tone underlying the comedic agenda presented by Stewart. Forms Comedy may be divided into multiple genres based on the source of humor, the method of delivery, and the context in which it is delivered. The different forms of comedy often overlap, and most comedy can fit into multiple genres. Some of the subgenres of comedy are farce, comedy of manners, burlesque, and satire. Some comedy apes certain cultural forms: for instance, parody and satire often imitate the conventions of the genre they are parodying or satirizing. For example, in the United States, parodies of newspapers and television news include The Onion, and The Colbert Report; in Australia, shows such as Kath & Kim, Utopia, and Shaun Micallef's Mad As Hell perform the same role. Self-deprecation is a technique of comedy used by many comedians who focus on their misfortunes and foibles in order to entertain. Performing arts Stand-up comedy is a mode of comic performance in which the performer addresses the audience directly, usually speaking in their own person rather than as a dramatic character. Events and awards Lists of comedians Mass media See also Notes The deliberate use by Menard of the term 'le rire' rather than 'l'humour' reflects accurately the current evidency to incorporate all instances of the comic in the analysis, while the classification in genres and fields such as grotesque, humour and even irony or satire always poses problems. The terms humour and laughter are therefore pragmatically used in recent historiography to cover the entire spectrum. That Comedy sprang up and took shape in connection with Dionysiac or Phallic ritual has never been doubted. References External links |
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[SOURCE: https://en.wikipedia.org/wiki/MMORPG] | [TOKENS: 5242] |
Contents Massively multiplayer online role-playing game A massively multiplayer online role-playing game (MMORPG) is a video game that combines aspects of a role-playing video game and a massively multiplayer online game. As in role-playing games (RPGs), the player assumes the role of a character (often in a fantasy world or science-fiction world) and takes control over many of that character's actions. MMORPGs are distinguished from single-player or small multi-player online RPGs by the number of players able to interact together, and by the game's persistent world (usually hosted by the game's publisher), which continues to exist and evolve while the player is offline and away from the game. MMORPGs are played throughout the world. Global revenues for MMORPGs exceeded half a billion dollars in 2005, and the western world's revenues exceeded a billion dollars in 2006. In 2008, the spending on subscription MMORPGs by consumers in North America and Europe grew to $1.4 billion. World of Warcraft, a popular MMORPG, had over 10 million subscribers as of November 2014. World of Warcraft's total revenue was $1.04 billion US dollars in 2014. Star Wars: The Old Republic, released in 2011, became the world's "fastest-growing subscription MMO in history" after gaining more than 1 million players within the first three days of its launch. Common features Although modern MMORPGs sometimes differ dramatically from their predecessors, many of them share the same basic characteristics. These include several common features: The majority of popular MMORPGs are based on traditional fantasy themes, often occurring in an in-game universe comparable to that of Dungeons & Dragons. Some employ hybrid themes that either merge or replace fantasy elements with those of science fiction, sword and sorcery, or crime fiction. Others draw thematic material from American comic books, the occult, and other genres. These elements are often developed using similar tasks and scenarios involving quests, monsters, and loot. In nearly all MMORPGs, the development of the player's character is the primary goal. Nearly all MMORPGs feature a character progression system, in which players earn experience points for their actions and use those points to reach character "levels", which makes them better at whatever they do. Traditionally, combat with monsters and completing quests for non-player characters, either alone or in groups, are the primary ways to earn experience points. The accumulation of wealth (including combat-useful items) is also a way to progress in many MMORPGs. This is traditionally best accomplished via combat. The cycle produced by these conditions, combat leading to new items allowing for more combat with no change in gameplay, is sometimes pejoratively referred to as the level treadmill, or "grinding". The role-playing game Progress Quest was created as a parody of this trend. Eve Online, a space-based MMORPG, uses an alternative method of progression where users train skills in real-time rather than using experience points as a measure of progression. In some MMORPGs, there is no limit to a player's level, allowing the grinding experience to continue indefinitely. MMORPGs that use this model often glorify top ranked players by displaying their avatars on the game's website or posting their stats on a high score screen. Another common practice is to enforce a maximum reachable level for all players, often referred to as a level cap. Once reached, the definition of a player's progression changes. Instead of being awarded primarily with experience for completing quests and dungeons, the player's motivation to continue playing will be replaced with collecting money and equipment. Often, the widened range of equipment available at the maximum level will have increased aesthetic value to distinguish high ranking players in game between lower ranked players. Colloquially known as endgame gear, this set of empowered weapons and armor adds a competitive edge to both scripted boss encounters as well as player vs player combat. Player motivation to outperform others is fueled by acquiring such items and is a significant determining factor in their success or failure in combat-related situations. MMORPGs almost always have tools to facilitate communication between players. Many MMORPGs offer support for in-game guilds or clans, though these will usually form whether the game supports them or not. In addition, most MMOGs require some degree of teamwork in parts of the game. These tasks usually require players to take on roles in the group, such as protecting other players from damage (called tanking), "healing" damage done to other players or damaging enemies. MMORPGs generally have Game Moderators or Game Masters (frequently referred to as GMs or "mods"), who may be paid employees or unpaid volunteers who attempt to supervise the world. Some GMs may have additional access to features and information related to the game that are not available to other players and roles. Relationships formed in MMORPGs can often be just as intense as relationships formed between friends or partners met outside the game, and often involve elements of collaboration and trust between players. Most MMORPGs provide different types of classes that players can choose. Among those classes, a small portion of players choose to roleplay their characters, and there are rules that provide functionality and content to those who do. Community resources such as forums and guides exist in support of this play style. For example, if a player wants to play a priest role in his MMORPG world, that player might buy a cope from a shop and learn priestly skills, proceeding to speak, act, and interact with others as their character would. This may or may not include pursuing other goals such as wealth or experience. Guilds or similar groups with a focus on roleplaying may develop extended in-depth narratives using the setting and resources similar to those in the game world. Over time, the MMORPG community has developed a sub-culture with its own slang and metaphors, as well as an unwritten list of social rules and taboos. Players will often complain about 'grind' (a slang term for any repetitive, time-consuming activity in an MMORPG), or talk about 'buffs' and 'nerfs' (respectively an upgrade or downgrade of a particular game mechanic). As with all such cultures, social rules exist for such things as invitations to join an adventuring party, the proper division of treasure, and how a player is expected to behave while grouped with other players. Infrastructure and Monetization Most MMORPGs are deployed using a client–server system architecture. The server software generates a persistent instance of the virtual world that runs continuously, and players connect to it via a client software. The client software may provide access to the entire playing world, or further 'expansions' may be required to be purchased to allow access to certain areas of the game. EverQuest and Guild Wars are two examples of games that use such a format. Players generally must purchase the client software for a one-time fee, although an increasing trend is for MMORPGs to work using pre-existing "thin" clients, such as a web browser.[citation needed] Depending on the number of players and the system architecture, an MMORPG might be run on multiple separate servers, each representing an independent world, where players from one server cannot interact with those from another; World of Warcraft is a prominent example, with each separate server housing several thousand players. In many MMORPGs the number of players in one world is often limited to around a few thousand, but a notable example of the opposite is EVE Online, which accommodates several hundred thousand players on the same server, with over 60,000 playing simultaneously (June 2010) at certain times. Some games allow characters to appear on any world, but not simultaneously (such as Seal Online: Evolution or Kolossium competition in Dofus); others limit each character to the world in which it was created. World of Warcraft has experimented with "cross-realm" (i.e. cross-server) interaction in player vs player "battlegrounds", using server clusters or "battlegroups" to co-ordinate players looking to participate in structured player vs player content such as the Warsong Gulch or Alterac Valley battlegrounds. Additionally, patch 3.3, released on December 8, 2009, introduced a cross-realm "looking for group" system to help players form groups for instanced content (though not for open-world questing) from a larger pool of characters than their home server can necessarily provide. MMORPGs today use a wide range of business models, from free of charge, free with microtransactions, advertise funded, to various kinds of payment plans. Some MMORPGs require payment or a monthly subscription to play. By definition, "massively multiplayer" games are always online, and most require some sort of continuous revenue (such as monthly subscriptions and advertisements) for maintenance and development purposes. Some games, such as Guild Wars, have disposed of the 'monthly fee' model entirely, and recover costs directly through sales of the software and associated expansion packs. Still others adopt a micropayment model where the core content is free, but players are given the option to purchase additional content, such as equipment, aesthetic items, or pets. Games that make use of this model often have originated in Korea, such as Flyff and MapleStory. This business model is alternately called "pay for perks" or "freemium", and games using it often describe themselves with the term "free-to-play". History MMORPG is a term coined by Richard Garriott to refer to massive multiplayer online role-playing games and their social communities. Previous to this and related coinages, these games were generally called graphical MUDs; the history of MMORPGs traces back directly through the MUD genre. Through this connection, MMORPGs can be seen to have roots in the earliest multi-user games such as Mazewar (1974) and MUD1 (1978). 1985 saw the release of a roguelike (pseudo-graphical) MUD called Island of Kesmai on CompuServe and Lucasfilm's graphical MUD Habitat. The first fully graphical multi-user RPG was Neverwinter Nights, which was delivered through America Online in 1991 and was personally championed by AOL President Steve Case. Other early proprietary graphical online RPGs include three on The Sierra Network: The Shadow of Yserbius in 1992, The Fates of Twinion in 1993, and The Ruins of Cawdor in 1995. Another milestone came in 1995 as NSFNET restrictions were lifted, opening the Internet up for game developers, which allowed for the first truly "massively"-scoped titles. Finally, MMORPGs as defined today began with Meridian 59 in 1996, innovative both in its scope and in offering first-person 3D graphics, with The Realm Online appearing nearly simultaneously. Ultima Online, released in 1997, is often credited with first popularizing the genre, though more mainstream attention was garnered by 1999's EverQuest and Asheron's Call in the West and 1996's Nexus: The Kingdom of the Winds in South Korea. The financial success of these early titles has ensured competition in the genre since that time. MMORPG titles now exist on consoles and in new settings. In 2008, the market for MMORPGs had Blizzard Entertainment's World of Warcraft dominating as the largest MMORPG, alongside other titles such as Final Fantasy XIV and Guild Wars 2, though an additional market exists for free-to-play MMORPGs, which are supported by advertising and purchases of in-game items. This free-to-play model is particularly common in South Korea such as MapleStory, Rohan: Blood Feud, Atlantica Online and Lost Ark. Also, there are some free-to-play games, such as RuneScape and Tibia, where the game is free, but one would have to pay monthly to play the game with more features. Guild Wars and its sequel avoid some degree of competition with other MMORPGs by only requiring the initial purchase of the game to play. Development The cost of developing a competitive commercial MMORPG title often exceeded $10 million in 2003. These projects require multiple disciplines within game design and development such as 3D modeling, 2D art, animation, user interfaces, client/server engineering, database architecture, and network infrastructure. The front-end (or client) component of a commercial, modern MMORPG features 3D graphics. As with other modern 3D games, the front-end requires expertise with implementing 3D engines, real-time shader techniques and physics simulation. The actual visual content (areas, creatures, characters, weapons, spaceships and so forth) is developed by artists who typically begin with two-dimensional concept art, and later convert these concepts into animated 3D scenes, models and texture maps. Developing an MMOG server requires expertise with client/server architecture, network protocols, security, and database design. MMORPGs include reliable systems for a number of vital tasks. The server must be able to handle and verify a large number of connections, prevent cheating, and apply changes (bug fixes or added content) to the game. A system for recording the games data at regular intervals, without stopping the game, is also important. Maintenance requires sufficient servers and bandwidth, and a dedicated support staff. Insufficient resources for maintenance lead to lag and frustration for the players, and can severely damage the reputation of a game, especially at launch. Care must also be taken to ensure that player population remains at an acceptable level by adding or removing servers. Peer-to-peer MMORPGs could theoretically work cheaply and efficiently in regulating server load, but practical issues such as asymmetrical network bandwidth, CPU-hungry rendering engines, unreliability of individual nodes, and inherent lack of security (opening fertile new grounds for cheating) can make them a difficult proposition. The hosted infrastructure for a commercial-grade MMORPG requires the deployment of hundreds (or even thousands) of servers. Developing an affordable infrastructure for an online game requires developers to scale large numbers of players with less hardware and network investment. In addition, the development team will need to have expertise with the fundamentals of game design: world-building, lore and game mechanics, as well as what makes games fun. Though the vast majority of MMORPGs are produced by companies, many small teams of programmers and artists have contributed to the genre. As shown above, the average MMORPG development project requires enormous investments of time and money, and running the game can be a long-term commitment. As a result, non-corporate (or independent, or "indie") development of MMORPGs is less common compared to other genres. Still, many independent MMORPGs do exist, representing a wide spectrum of genres, gameplay types, and revenue systems. Some independent MMORPG projects are completely open source, while others feature proprietary content made with an open-source game engine. The WorldForge project has been active since 1998 and formed a community of independent developers who are working on creating framework for a number of open-source MMORPGs. The Multiverse Foundation has also created a platform specifically for independent MMOG developers. Trends As there are a number of wildly different titles within the genre, and since the genre develops so rapidly, it is difficult to definitively state that the genre is heading in one direction or another. Still, there are a few obvious developments. One of these developments is the raid group quest, or "raid", which is an adventure designed for large groups of players (often twenty or more). Instance dungeons, sometimes shortened to "instances", are game areas that are "copied" for individual players or groups, which keeps those in the instance separated from the rest of the game world. This reduces competition, and also reducing the amount of data that needs to be sent to and from the server, reducing lag. The Realm Online was the first MMORPG to begin to use a rudimentary form of this technique and Anarchy Online would develop it further, using instances as a key element of gameplay. Since then, instancing has become increasingly common. The "raids", as mentioned above, often involve instance dungeons. Examples of games which feature instances are World of Warcraft, The Lord of the Rings Online, EverQuest, EverQuest II, Aion, Final Fantasy XIV, Guild Wars, Rift, RuneScape, Star Trek Online, Star Wars: The Old Republic, and DC Universe Online. Increased amounts of "player-created content" is another trend. The use of intellectual property licensing common in other video game genres has also appeared in MMORPGs. 2007 saw the release of The Lord of the Rings Online, based on J. R. R. Tolkien's Middle-earth. Other licensed MMORPGs include The Matrix Online, based on the Matrix trilogy of films, Warhammer Online: Age of Reckoning, based on Games Workshop's table top game, Star Wars Galaxies, Star Wars: The Old Republic, Champions Online and Age of Conan. Additionally, several licenses from television have been optioned for MMORPGs, for example Star Trek Online and Stargate Worlds (which was later canceled). The first console-based MMORPG was Phantasy Star Online for the Dreamcast. The first console-based open-world MMORPG was Final Fantasy XI for the PlayStation 2. EverQuest Online Adventures, also on the PlayStation 2, was the first console MMORPG in North America. Although console-based MMORPGs are considered more difficult to produce, the platform is gaining more attention. With the popularization of Facebook and microtransactions came a wave of Flash and HTML5 based MMORPGs that use the free to play model. They require no download outside of a browser and usually have heavily integrated social media sharing features. Smartphones with their GPS capabilities (amongst others) enable augmented reality in games such as Ingress and Pokémon Go. The games are enhanced by location and distance based tracking, bench marking goals or facilitating trade between players. In society and culture Since the interactions between MMORPG players are real, even if the environments are virtual, psychologists and sociologists are able to use MMORPGs as tools for academic research. Sherry Turkle has found that many people have expanded their emotional range by exploring the many different roles (including gender identities) that MMORPGs allow a person to explore. Nick Yee has surveyed more than 35,000 MMORPG players over the past several years, focusing on psychological and sociological aspects of these games. Recent findings included that 15% of players become a guild-leader at one time or another, but most generally find the job tough and thankless; and that players spend a considerable amount of time (often a third of their total time investment) doing things that are external to gameplay but part of the metagame. Many players report that the emotions they feel while playing an MMORPG are very strong, to the extent that 8.7% of male and 23.2% of female players in a statistical study have had an online wedding. Other researchers have found that the enjoyment of a game is directly related to the social organization of a game, ranging from brief encounters between players to highly organized play in structured groups. In a 2008 study by Zaheer Hussain and Mark D. Griffiths, it was found that just over one in five gamers (21%) said they preferred socializing online to offline. Significantly more male gamers than female gamers said that they found it easier to converse online than offline. It was also found that 57% of gamers had created a character of the opposite gender, and it is suggested that the online female persona has a number of positive social attributes. A German fMRT-study conducted by researchers of the Central Institute of Mental Health points towards impairments in social, emotional and physical aspects of the self-concept and a higher degree in avatar identification in addicted MMORPG players, compared to non-addicted and naive (nonexperienced) people. These findings generally support Davis' cognitive behavioral model of Internet addiction, which postulates that dysfunctional self-related cognitions represent central factors contributing towards the development and maintenance of MMORPG addiction. The high degree of avatar identification found by Leménager et al. in the addicted group of this study indicates that MMORPG playing may represent an attempt to compensate for impairments in self-concept. Psychotherapeutic interventions should therefore focus on the development of coping strategies for real-life situations in which addicted players tend to experience themselves as incompetent and inferior. Richard Bartle, author of Designing Virtual Worlds, classified multiplayer RPG-players into four primary psychological groups. His classifications were then expanded upon by Erwin Andreasen, who developed the concept into the thirty-question Bartle Test that helps players determine which category they are associated with. With over 650,000 test responses as of 2011, this is perhaps the largest ongoing survey of multiplayer game players. Based on Bartle and Yee's research, Jon Radoff has published an updated model of player motivation that focuses on immersion, competition, cooperation and achievement. These elements may be found not only in MMORPGs, but many other types of games and within the emerging field of gamification. There have been numerous discussions and evaluations by various scholarly institutions regarding the long-term effects of video game overuse. Many news agencies have criticized video games as promoting violent tendencies in its player base and encouraging anti-social behaviors. Ultimately this culminated in the World Health Organization classifying the overuse of video games as "Technological Addiction" in May 2019. In World of Warcraft, a temporary design glitch attracted the attention of psychologists and epidemiologists across North America, when the "Corrupted Blood" status effect began to spread unintentionally—and uncontrollably— outside of the high-level battle it was intended to be limited to and into the wider game world. The Centers for Disease Control intended to use the incident as a research model to chart both the progression of a disease, and the potential human response to large-scale epidemic infection. However, due to Blizzard Entertainment's failure to keep statistical records of the event, the 2005 Corrupted Blood Outbreak ultimately failed to produce any results. Nevertheless, the CDC has continued to express interest in the use of MMORPGs for disease research. It has been suggested by Springer University in Germany that MMORPGs encourage and provide opportunities to study and improve in economic theory by providing a controlled environment for the natural development of economic practices between players of including professions, trade, and services. Research has shown that for the positive learner, game-based interaction could reduce inhibition as well as enhance the enjoyment and motivation of second language learning, but appears to be more suitable for learners of intermediate and higher levels of proficiency than language beginners. The Division of Autism and developmental disabilities published a significant report detailing the value of MMORPGs for the treatment of individuals with autism spectrum disorder. The report suggests that individuals with autism spectrum disorder could benefit from MMORPGs by being provided a space to freely develop social skills and communication skills without the stress of face-to-face contact. This in turn opens new pathways for social therapy for individuals with developmental disabilities. Many MMORPGs feature living economies. Virtual items and currency have to be gained through play and have definite value for players. Such a virtual economy can be analyzed (using data logged by the game) and has value in economic research. More significantly, these "virtual" economies can affect the economies of the real world. One of the early researchers of MMORPGs was Edward Castronova, who demonstrated that a supply-and-demand market exists for virtual items and that it crosses over with the real world. This crossover has some requirements of the game: The idea of attaching real-world value to "virtual" items has had a profound effect on players and the game industry, and even the courts. The virtual currency selling pioneer IGE received a lawsuit from a World of Warcraft player for interfering in the economics and intended use of the game by selling WoW gold. Castronova's first study in 2002 found that a highly liquid (if illegal) currency market existed, with the value of Everquest's in-game currency exceeding that of the Japanese yen. Some people even make a living by working these virtual economies; these people are often referred to as gold farmers, and may be employed in game sweatshops. Game publishers usually prohibit the exchange of real-world money for virtual goods, but others actively promote the idea of linking (and directly profiting from) an exchange. In Second Life and Entropia Universe, the virtual economy and the real-world economy are directly linked. This means that real money can be deposited for game money and vice versa. Real-world items have also been sold for game money in Entropia, and some players of Second Life have generated revenues in excess of $100,000. Some of the issues confronting online economies include: Linking real-world and virtual economies was rare in MMORPGs as of 2008, as it is generally believed to be detrimental to gameplay. If real-world wealth can be used to obtain greater, more immediate rewards than skillful gameplay, the incentive for strategic roleplay and real game involvement is diminished. It could also easily lead to a skewed hierarchy where richer players gain better items, allowing them to take on stronger opponents and level up more quickly than less wealthy but more committed players. See also References Further reading |
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[SOURCE: https://en.wikipedia.org/wiki/Seri_people] | [TOKENS: 3848] |
Contents Seri people The Seri or Comcaac people are an indigenous group of the Mexican state of Sonora. The majority reside on the Seri communal property (Spanish: ejido), in the towns of Punta Chueca (Seri: Socaaix) and El Desemboque (Seri: Haxöl Iihom) on the mainland coast of the Gulf of California. Tiburón Island (Tahejöc) and San Esteban Island (Cofteecöl and sometimes Hast) were also part of their traditional territory. They maintain an intimate relationship with both the sea and the land. They are one of the ethnic groups of Mexico that has most strongly maintained their language and culture throughout the years after contact with Spanish and Mexican cultures. The Seri people are not related culturally or linguistically to other groups that have lived in the area, such as the Opata, Yaqui (sg.: Yequim, pl.: Yectz), O'odham (sg.: Hapaay), or Cochimí. The Seri language is distinct from all others in the region and is considered a language isolate. Beside the Apache (sg.: Hapats, pl.: Hapatsoj) and Yaqui, the Seri are best known as fierce warriors for their resistance against subjugation by the Spanish (sg.: Casopin) and later Mexicans (sg./pl.: Cocsar). The Seri had been living on the coast of Sonora with little outside interference for centuries, if not millennia. But with colonization, they were displaced from their land and forced to work for others and adopt Christianity. Reséndez writes about a slaving raid in 1660s: "A posse of Spaniards had cut a swath through the Seri lands, killing most of the adults of one band and distributing the children in the Spanish towns of Sonora." The name Seri is an exonym of uncertain origin. (Claims that it is from Opata or from Yaqui were nineteenth-century speculations based on similarity to words in those languages and lack clear evidence.) Their name for themselves is Comcaac (phonemically /kom'kɑːk/, phonetically [koŋˈkɑːk]); singular: Cmiique (phonemically /'kmiːkɛ/, phonetically [ˈkw̃ĩːkːɛ]). Seri territory The Seri territory in the state of Sonora spans an area of approximately 211,000 hectares (520,000 acres) of land and is located on both continental land as well as land from Tiburon island, which is located in the Gulf of California off the central coast of the state. The Seri primarily inhabit the towns of El Desemboque (Haxöl Iihom, 29°30'13"N, 112°23'43"W), the municipality of Pitiquito, Punta Chueca (Socaaix, 29°0'54"N, 112°9'42"W), and the municipality of Hermosillo located on the coast of Sonora. Following the fishing cycles, the location of some individuals and their relatives can vary between all fishing territories which are located along 100 km (62 mi) of coastline. Infrastructure Through a road to the south, the residents of Punta Chueca communicate with the village of Bahía de Kino. Towards the north, a road connects Desemboque with the city of Puerto Libertad. Each village has schools for students at preschool, secondary, and primary levels. History In the pre-Hispanic period, the territory of the Seri was located between the mountains, the Encinas desert, and the Gulf of California. The territory extended from the Altar desert in the north to the Yaqui river in the South and from Horcasitas in the east to the nearby islands of Tiburón, San Esteban, Patos, and Alcatraz in the west. As a nomadic people, the Seri travelled across an area that corresponds to fourteen current municipalities of Sonora. It was believed in this period that the Seri people were organized into six bands, divided into their own clans based on their paternal lineage. On a daily basis, there was no leader figure within the clan. Leaders were named only under extraordinary circumstances, such as during war or difficult hunting, and fishing seasons. Only the most capable person was appointed to fulfil this position as leader. The persecution of the Seri people by the Spanish and Mexican military began in the mid-18th century. Expeditions by the Mexican military were led against the Seri and continued to decimate their population and territory until the early 1900s. The Seri people were the antithesis of what the Spanish conquistadors sought. Their territory was not very useful, they did not have accumulated wealth, they did not produce enough to make the conquest profitable, and they were not suited as laborers to cultivate and serve as they were not familiar with that lifestyle. Because of this, the Seri people preserved their autonomy and culture for much longer than other Indigenous peoples. During the colonial period, the Jesuits, who tried to evangelize them and teach them agricultural practices, were the most sustained contact the Seri had with outsiders. Their letters provide the earliest and most comprehensive descriptions of the people. None of their efforts, however, were successful, and the Seri always returned to their desert lifestyles which is why they were always considered an unlawful group. The Spanish, then later the Mexicans, tried to effectively kill off all of the Seri which led to the nearly total annihilation of the group. However, the Seri people were never formally conquered or evangelized during that time. Little by little they were confined to a part of their territory and decimated in number. By the time of Mexican independence, the previous organization system had been dismantled, and the Seri were almost entirely settled on the mainland. However, throughout the first two-thirds of the 19th century, they were persecuted and nearly annihilated by both Mexican soldiers and ranchers. Some of the Seri people managed to seek refuge on Tiburón Island. The scarcity of water and of animals for hunting, along with various diseases, were the predominant factors as to why the Seri people abandoned their refuge on Tiburón Island and returned to the mainland. They were first temporarily hired as fish merchants and ranchers and later settled down. Among the external causes that allowed their successful return to the mainland was the crisis of 1929, which caused a large migration of poor people to cities and agricultural centers in northern and northeastern Mexico. This increased the consumption of fish and other marine products, which were cheaper than beef. From that moment, the Seri people began to occupy an essential role in the economy of commercial exchange and to use money in their market operations. This began a period in which rapid structural, organizational, and cultural changes occurred. Bands The Seri were formerly divided into six bands. They were: Three of the bands were further subdivided. Relations between bands were not always friendly, and internal conflict sometimes occurred. Some bands were also living on the Baja California Peninsula (Hant Ihiin), they were called Hant Ihiini comcaac. It has been said that these groups spoke three distinct but mutually intelligible dialects. It is thought that the first dialect was spoken by the Xiica hai iic coii, Xiica xnaai iic coii, Tahejöc comcaac and Heeno comcaac Bands and presently this variant is the only dialect spoken and is the ancestor of modern-day Seri. The second dialect was spoken by the Xnaamotat Band, but it is currently extinct and there was very little data collected regarding this dialect. The third dialect is also extinct and was spoken by the Xiica hast ano coii Band; it was described as sounding musical, as if speakers were singing instead of speaking (Moser 1963). Speakers sometimes make remarks regarding certain expressions being characteristic of particular Bands, especially of the Xiica hast ano coii Band. These communication differences were thought to have kept the groups from having much social interaction with each other. After the Seri population was greatly reduced by conflicts with the Mexican government and the O'odham, and epidemics of smallpox and measles, the remaining Seris grouped together and the band divisions were lost. Language The Seri language, cmiique iitom, is a language isolate because there is not sufficient evidence of a relationship between it and any other language. Currently the majority of the population is bilingual to a certain degree, although they prefer to speak their own language in their local activities. Speakers maintain an enormously rich oral tradition that preserves their history and culture. In the last few decades, a very small part of this tradition has presented itself in a written form. The Seri language has a plethora of terms in order to describe kinship relationships many of which describe both the sex of the subject and the sex of the speaker. For example, there are four terms to describe grandparents, each term specifies to which parent the grandmother or grandfather belongs to. Additionally there are many terms to describe siblings which account for the age and sex of the referent and speaker. Health The preservation of knowledge on traditional therapies and techniques may be lacking among the Seri. They possess knowledge about some plants that can be used to cure mild illnesses but the study of Seri ethnomedicine is still being investigated today. The biodiversity of their arid climate and inability to maintain standard agricultural practices and livestock means that the knowledge of their ethnomedicines is very valuable. Marine resources like molluscs and algae were used for medicinal purposes in addition to terrestrial plants. The nomadic lifestyle of the group caused changes in their diet and patterns of consumption which has generated varying health problems like diabetes. There is presently a lack of medicinal specialists amongst the Seri. For traditional medical treatment, potential Seri patients travel to nearby communities or the state capital in order to receive treatment. Women still maintain some knowledge of traditional medicines and prepare traditional medicinal items like soaps and creams to sell to outsiders. There is record of two previously known medicinal specialists in Seri history. Cola conáajj was a midwife who used resources from regional flora and fauna to assist with pregnancy and labor. Ziix haaco cama was a noted spiritual specialist who also utilized traditional Seri medicine. Seri knowledge of their physical environment has resulted in the publication of material about Seri ethnobotany which showcases how the Seri have preserved a lot of information about their centuries-long coexistence with the flora and fauna of their region. The severe ecological conditions of their environment and its changeability is a driving force behind their knowledge of flora and fauna of the area as the ability to remain nomadic due to these conditions was a necessity. Housing In Seri villages, houses are mainly made of concrete blocks with a concrete or asbestos roof, although it is possible to find some houses made of cardboard. In general, these houses consist of a kitchen, dining room, bathroom, and one or two bedrooms. This type of housing was promoted and supported by the federal and state government between 1974 and 1984. In fishing areas it is still possible to find traditional houses that are made of shelters made of grasses and other materials (traditionally loggerhead shells) on top of an ocotillo frame (Fouquieria splendens). These shelters only house a single family and are suitable for a nomadic lifestyle. This type of construction is used for traditional festivals as well. Territory and ecology The current territory of the Comcaac has a total area of 211,000 ha (520,000 acres), of which 91,000 ha (220,000 acres) were provided through ejido rights and 120,000 ha (300,000 acres) were provided through communal endowment. Due to the territorial extension with which they were endowed and their small population, the Seri, along with the Lacandones, can be considered the Indigenous people with the greatest land possession in Mexico. However, the difficult environmental conditions of their land makes it very hard for the Seri to utilize their territory for agricultural purposes. Due to this, the Seri have never practiced agriculture throughout their history. In general, the surface of Seri territory is flat, apart from some elevations like the Seri mountain range, the Kunkaak mountain range, and some parts of the coastline. The soil of the land is generally shallow and in some parts up to 80% stoney. In the valleys, the soil is loamy and sandy. Due to the permeable characteristics of the soil there are no rivers, lakes, or important currents except for the San Ignacio river that runs from the nearby mountains and ends near Desemboque, but this river is still temporary and has a weak flow. Tiburon Island is provided with five watering holes in total which are currently not enough to sustain the total population. The climate of the region is hot with rainfall of 75 to 200 mm (3.0 to 7.9 in) per year; the primary climate is extremely dry or desert conditions. The temperature of the region can reach minimums of −8.5 °C (16.7 °F) in the winter months of December to February and highs of 49.5 °C (121.1 °F) between the months of June and August. With such dramatic regional characteristics, the development of agriculture has been impossible up to now and maintaining livestock has been difficult due to water scarcity. Therefore, the main resource that is relied on is the 100 km (62 mi) of coastline that the Seri have for their own exclusive use. Despite the aridity of the desert, the Seri have knowledge of how to exploit the flora and fauna of the area. Fishing, particularly harvesting crabs and scallops, along with traditional ironwood carvings, elaborate basket making, and necklace work have been the main sources of income for the Seri. In general, Seri are not used to leaving their territory in search of work. Social organization The Seri came to establish systems of reciprocity and resource distribution through kinship relationships which ensure the total survival of the group. One of these systems is named quiimosim, which gives every member of the tribe the right to request part of the food that is consumed in the community without prior invitation. Another is canoaa an hant cooit, the right to ask for fish to eat from any panga that comes from the sea. Through an additionally complex system, assets are also shared between families. With the formal integration of the Comcaac into national life, they have been forced to name a series of authorities such as a supreme council, a communal commission, the comunal property council, and a fishing cooperative society. Cosmology and religion The Seri did not develop a complex system of religious governance. Their interpretation of the world, its rites, its festivals, and other cultural manifestations are closely related to nature and the biological and social aspects of the group. Their main traditional rites are linked to the onset of puberty and death. Their songs and stories revolve around the sea, animals, and ancient feats of heroes and warriors. Not having been formally evangelized in colonial times, they do not have the Catholic elements that many other Indigenous groups have. In the Seri area there are no Catholic churches or priests. There are two Protestant temples of the Apostolic Church of the Faith of Jesus Christ, a church that many people in the community belong to. Despite the cultural mix, they maintain their language and cultural practices. Music The Seri have preserved much of their Indigenous music, which distinguished them from almost all other ethnic groups in Mexico. Instrumental music and most traditional instruments are less commonly in use but songs are still an important part of Seri culture. Instruments like foot drums or rattling gourds may be used to accompany quick and repetitive Seri singing. The rhythms and percussion provided by dancers may also be used to accompany songs. Singing is a cultural tradition practiced by many Seri of all ages in order to describe the world around them. Some songs even feature knowledge of their ecological environment and the ethnobotanical aspects of their culture which has allowed them to survive under difficult environmental conditions. While there are virtually no written records kept by the Seri, their songs have served as libraries of knowledge about their history, beliefs, and culture. Songs are often repeated, with many songs being sung in quantities of four. There are various types of songs, but not all are well represented in modern day and others are more commonly heard in public performances. The most interesting ones are often sung in private situations. The Seri are reluctant to formally record many songs, including many songs of mourning, because they either believe they should not be performed out of context or they are too personal. The types of songs include: Ethnonym The ethnonym of the Seri people, Comcaac, was first recorded by United States Boundary Commissioner John Russell Bartlett, who was in the area for a short visit in early 1852. The word was included in the list of approximately 180 words that Bartlett archived in the Bureau of American Ethnology (now part of the National Anthropological Archive, housed at the Smithsonian). He recorded the word as "komkak", which reflected the pronunciation of the word at that time (although he missed the vowel length and did not indicate stress). Other word lists, obtained by other people during the last half of the nineteenth century, confirm that pronunciation. The phonetic rule by which the consonant /m/ is pronounced as a velar nasal in this context (after an unstressed vowel and preceding a velar consonant) may not have come about until sometime in the early twentieth century or researchers may have encountered slow-speech deliberate pronunciations for which the assimilation was held in abeyance. The singular form, Cmiique, was first recorded by French explorer and philologist Alphonse Pinart in 1879. He recorded the word as "kmike", which must have reflected the pronunciation of the word at that time (although he also missed the vowel length). The phonetic rule by which the consonant /m/ is pronounced as a nasalized velar approximant in this context (after a velar stop) may not have come about until sometime in the mid twentieth century. In media Diet The Seri are the only people known to have harvested the maritime Zostera marina seagrass species for its seeds, before their nutritional value was discovered in recent times. Notes Bibliography External links |
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[SOURCE: https://en.wikipedia.org/wiki/Complex_societies] | [TOKENS: 4126] |
Contents Complex society A complex society is characterized by the following modern features: The term is mostly used as shorthand to indicate a society with intricate political organization and using technology to expand economic production. Emergence of complex societies Before human beings developed complex societies, they lived in primitive societies. The historical consensus is that complex societies emerged from primitive societies around 4000-2000 BCE in Egypt, Mesopotamia, the Indus Valley and China. According to traditional theories of how states emerged, the initial spark for the development of complex societies was an agricultural surplus. This economic specialization leads to divisions of labor. The economic transition from an agricultural economy to a division of labor is the most basic explanation of how societies go from primitive to complex. Before the rise of complex societies, there was little need for a strong, centralized state government. The increase in populations in these societies meant that the society was too big to rely on interpersonal and informal connections to resolve disputes. This meant there was a need for a hierarchical authority to be acknowledged as the final arbiter in such scenarios. This judicial authority was also able to claim military, economic and religious authority. Often, a claim to one realm was enough to support political ambitions in other realms. This hierarchical decision-making structure became the state, which distinguishes primitive from complex societies. The evolution of complex societies can be attributed to several factors. The prevalent theory which explains the start of complex societies is the pressure exuded by warfare or a method to organize a population of approximately more than 150. Warfare contributes to establishing complex societies by creating pressure for comprehension between groups which strengthens the cooperation in groups, it improves the organization of the groups structure, and pushes the desire to grow the population of the group. The growth of population results in the loss of person to person interaction which creates a need for a system to keep track the interaction between the leads of the group. The groups would then create symbols of either language, clothing or ideology to identify who belongs to the group and their position in the society. The process of identifying who resides in the groups also expands to identifying the power structure of the group. The identification of the power structure within the group is commonly distributed as a hierarchical power structure meaning groups are organized with one head of the group overseeing the whole group. The group will eventually grow to a state in which labor is divided within specializations meaning that there are branches in the society that are in charge in military affairs, laws, or religion of said society, the elites of the society occupied the leading positions in the branches. Linear development of traditional complex civilizations These represent the four conventional stages of how civilizations are usually understood[by whom?] to form. Hunter-gatherer culture developed in the early prehistoric era. Evidence traces them as far back as 2 million years ago. As primarily nomadic groups, they valued the idea of kinship; moreover, these kinship-focused groups recognized status via age as they viewed their elders as the wise ones from the group. Consequently, they discovered the use of fire and developed intricate lithic tools for hunting. These early humans showcase the early beginnings of both social and biological evolution ideals. They were egalitarian by nature, hunting enough food and shelter, while the division of labor was predominantly gender-based with the advancement of hunting. Additionally, the domestication of animals and plants sparked the Neolithic Revolution. The transition was slow-forth as more developed societies began to develop more effective agricultural methods to meet their needs. This complexity fueled growth in the early civilization of Mesopotamia and other early civilizations. Sedentary societies, more commonly known as tribes, are rarely more than a few thousand individuals who are settlers. They've adapted agricultural innovation, by focusing on horticulture and the domestication of plants & animals. As they derived Neolithic roots of being kinship-focused and respecting their elders and the knowledge they have due to their age. As early Mesopotamia was developing, the Ubaid culture started off as one of the first sedentary villages. Before expanding into a fully developed empire, the Ubaid culture had the domestication of animals and plants such as: wheat, barley, lentils, sheep, goats, and cattle. Additionally, they developed an irrigation system to better serve their agricultural needs, which was further developed on a larger scale in civilizations and expanded beyond agricultural purposes. Chiefdoms are stratified societies that characteristically have a two-tier settlement pattern, with a central town for administrative and religious duties surrounded by satellite farming villages. They are distinguished from tribes by hereditary inequality between those born into the chiefly class and those born as commoners. The chief and his or her relatives are also often considered divine. Chiefdoms may arise out of necessity under external threat. Villages might join under a leader who is believed to deliver followers from harm, and in the process, the leader may become deified. Once a chiefdom is formed, adjacent communities have few choices except to join the chiefdom, leave the region, or form a rival chiefdom. States are stratified societies that are more complex than chiefdoms. States often have a three-tier settlement pattern consisting of cities, towns and farming villages. Cities are surrounded by towns that are headed by minor administrators who interact on behalf of the elites with the neighboring villages. Writing first developed in states as a way to organize tax collection, public work and military service. Factors So there are four core components that enabled the creation and development of an organized power structure. The concept of a complex society and modern state was born from a need for cohesive organization and for protection from external threats. The emergence of a civilized or complex society is derived from agricultural developments, necessary division of labor, a hierarchical political structure, and the development of institutions as tools for control. Collectively, they create the conditions for a society of complex nature where a new kind of relationship between people emerges. The relationship that emerges is a dependency between one group providing wealth and food and the other who governs and provides protection.[citation needed] The transition from agrarian, nomadic individuals to industrial and sedentary habits emerged from the improvements made in agricultural and central food planning. Early sedentary societies have been argued to emerge as early as 1600 BCE along southern Mexico, as there is a correlation between domesticated plant production, sedentism and pottery artifacts. The establishment of a nomadic society entails an emergence of social relations, affecting the patterns and roles each person is tasked with as means for survival. Farmers often found ways to expand agricultural posts by planting on hills and slopes, finding ways to work around environmental and land challenges. Similarly, developments in agriculture enabled societies to focus on central organization, planning and the development of urban centers. Agriculture in the absence of modern industry was a critical source of wealth, even though pre-industrial outputs were fairly low. The advent of tools such as mechanization, mass-produced fertilizer, scientific plant breeding and other farming techniques enabled the average farmer to increase his yield, therefore enabling him to feed more people. Aiding in not only population growth, but also the specialization and division of labor needed to form a complex industrial society. Therefore, the expansion and industrialization of agriculture allowed for the evolution of an agrarian society, where wealth came from agriculture, to a complex society, where manufacturing and industry become sources of wealth, and created a system that could support a division of labor, a political hierarchy and new institutions. A core tenet of complex society was a transition from agrarian and kinship societies to complex, industrial societies. The transition occurs as a result of specialization in the means of labor, with some people rising to power as rulers and administrators, while others remained as food producers. This was one of the first divisions of labor. In an agrarian or simple society, there is no division between the producers and the maintainers. The whole community was involved in both decision-making and food production. Small communities did not have the need for this division, as the whole community worked together. However, the splitting of agriculture and governance was arguably the most crucial division of labor, and created lasting consequences. Specifically, it resulted in the emergence of the state as a concentration of a society's power. This kind of relationship, one between the producers and the maintainers (or rulers), is a highly unequal and dependent one. Historically, internal differentiation has usually preceded the arrival of state structures, and while that alone has not necessarily been enough to push every society through the evolution from primitive to complex, it remains that specialization is a prerequisite for the emergence of a ruling class—rulers specialize in power. A division of labor encourages a society to differentiate, and heightens the material and intellectual culture of that society. While division of labor and specialization are similar, they are not the same. Specialization does not always end in a division of labor. One person can specialize in growing wheat while another can specialize in growing corn, but that does not end in the evolution of a state. The emergence of a political hierarchy, discussed next, was a direct result of a division of labor that ended in a concentration of power. Complex and industrialized societies consist of people divided into different sectors of the labor spectrum. Leaders and administrators are in charge of providing security, safety and coordination of the state activities. Control based on ranking from centralized power first presupposed modern states in the form of chiefdoms. Such rulers possess monopoly on resources, as well as the mechanisms to resolve conflict and deliver punishment. Political hierarchy entails a division between specialization, placing some members in charge of administration and institutions with the highest controls of enforcement. Political hierarchy and organization renders the vast majority of people away from centralized power roles and allocates decisions into a few hands enabling them to pursue policies which might benefit the state or the power holder. Politically hierarchy is not usually decided by the existence of social contracts, where some agree to grow food while others provide political services and protection, but rather through some[clarification needed] Part of this political hierarchy is the coercion of the producers by the ruling class played a big role in the development of civilizations[clarification needed]. For example, once a person or a group of people gain power, they will exercise their power by creating institutions and developments which the producers must then support, most commonly through force. The creation and sustainability of civilization and a state entails social, cultural and institutional complexity, otherwise called “ultra-sociality.” High position holders, through the arm of the state, hold the power to define, enforce and execute rules and violence. States hold unanimous power to resolve disagreement and possess the mechanisms to coerce people as means to achieve order. Institutions assist rulers in the coordination of behaviors and norms, enabling the control of behaviors among large groups of humans. In fact, institutions with flexibility to absorb different polities are crucial to the development and stability of an emerging state. The role of institutions is thus crucial in the implementation of standard practices to ensure cohesive order and rules for interactions. Without this type and scale of human organization, it would have been impossible for societies to emerge from their agrarian roots. Institutions allow for the state to coordinate the actions of its society so as to defend itself, settle disputes within its borders, improve production means, protect the welfare of its people, and thus create the material and cultural developments we appreciate today. Socioeconomics during pre-industrial era During the pre-industrial era, population size within cities were small with elites covering only 2% of the population. It was important for cities to be located close to watered areas and would depend on trade through ports and this would include rivers. With cities being located near water areas, they depended on farmers for agricultural produce. Agriculture was the main source of wealth and food. Farmers, cattle farmers, fishermen and hunters were the main producers of food. Farmers were not as fortunate to trade, for which they were limited to because of the cost of the transportation. This would mean that trade was limited to a four-mile radius. Because agriculture was the main source of wealth, farmers would have to sell their harvest right away, having them sell their produce for a low price. In other cases, farmers would feed on their cultivation instead of selling their produce. Many peasants would live on the lands of the elite and cultivate their produce within the lands and give it to the elites once it was harvested. During the beginning of the pre-industrial area this was how farmers would pay their rent and the landowners would sell the produce at a high price. Labour work was not only achieved by everyday workers but it was also accomplished with slaves. Many of these slaves were captured during wars, were enslaved from different countries, and lost children. In some occasions people had been sold by either their spouse or parents, or had debt and became a slave in order to pay their debt. With slavery dating as far back as early 300 BCE, from a census taken in Attica, had occupied around 400,000 slaves. During the pre-industrial era, labour was forced and was implemented by the government and landlords. This would also mean that many peasants were forced into labour. It was very important for employers to hire someone when they were recommended. It was important for the employer to trust the employee, many would form networks in helping each other by proving a recommendation in exchange of returning the favor. Many people who lived in the countryside or within the city, would find themselves moving around looking for an affordable place to live. Some countryside folks would find an occupation by working for an elite. Mesoamerica Southeastern Mesoamerica became the first to develop into a complex society. Maize was very important in the early pre-classic period. Even though farming was very important, there were also hunters, gatherers, and fisherman. Food produce besides corn, bean and squash, squirrel, deer, birds, snakes, crocodile, iguana were also consumed. Egypt Prior to 3000 BCE the Nile river valley and delta were, like the majority of the world, small agricultural societies loosely associated with little cohesion. The first unified kingdom was founded by King Menes in 3100 BCE which led to a series of successful dynasties which cultivated the development of Egyptian cultural identity. By the Third Dynasty of the Old Kingdom, Egypt was a fully integrated empire with a complex vertical hierarchical bureaucracy which enacted the will of its ruler and interacted with every citizen. The economic strength and military might of these dynasties spread their influence and presence through the Eastern Mediterranean as well as into North Africa and southward in Nubian controlled territories. France France is a good example of a complex society due to its history being well known and documented. Thus, historians can trace just how the rise of medieval France occurred. The evolution of ancient Gaul into early modern France provides an example to how complex societies have come into being. There existed a degree of continuity in the hierarchical organization of France from the Iron Age to the 18th century. When the Romans attempted to organize Gaul, they altered the tribal structures which were not simple, but were rather complex chiefdoms. The integration of a large territory in France happened repeatedly between the Iron Age and the early modern age. It did not happen all at once, however, occurring in small steps. The integration proceeded in a hierarchical manner. Disintegration also occurred in a multi-step process. France was disintegrated into units that were fragmented into counties and in some regions, even further into castellanies. By the end of the ninth century, at least twenty-nine independent politics were in France. Nearly a century later, the number had grown to at least fifty-five. The history of France traces the evolution of hierarchical complexity as complex large-scale societies came about through warfare. Early modern France was a five-level hierarchy where the largest level of organization was divided in provinces, gouvernements, which was then in turn subdivided into smaller units called bailliages. This theory makes sense as a society can engage in warfare to grow and increase in size, resources and diversity. Alternative theories In a 2009 paper Turchin and Gavrilets argue that the emergence of complex societies is a response to the existential threat of violent warfare. They build upon the work of Karl Jaspers' conception of the Axial Age, whereby in the era 800 - 200 BC human societies undergo a revolutionary shift. The central mechanism which pushes societies into a complex stage is the intensity of the warfare. When war takes place across a meta-ethnic frontier, such as between agricultural and nomadic peoples, is when warfare is sufficiently intense to shift the society into a different state. Within the Axial Age, an increase in warfare intensity between the steppe peoples and the Persian and Chinese peoples forged the Achaemenid Persian empire and the Han Chinese empire, both complex societies. This theory has also been extended to explain the rise of complex states in Africa and Asia. The colonization of these places by European powers functioned as a meta-ethnic frontier in which warfare met the necessary level of intensity to forge the complex society. Another theory deals with the social evolution of altruism versus selfishness in the context of conflicting forces. D.S. Wilson and E.O. Wilson state that selfishness beats altruism within a group but groups that are altruistic beat out groups that are selfish as there is a higher level of cooperation and coordination within an altruistic group. Whether or not a group will be altruistic and cohesive is dependent on both individual efforts as well as exterior forces. The success of a group in competition with other groups is dependent upon cooperation within. The Collapse of Complex Societies Joseph Tainter (the author of The Collapse of Complex Societies) argued that as complex societies try to deal with the problems that they face, they tend to become more and more complex. This complexity exists under the purview of mechanisms that coordinate numerous differentiated and specialized social and economic roles by which complex societies are recognized. To deal with the problems that it faces, a society resorts to creating bureaucratic layers, infrastructure, and changes of social class that are relevant in addressing the problems. Tainter gives the Western Roman Empire, the Maya civilization, and the Chaco culture as examples of collapsed complex societies. In the case of the Roman Empire, for example, reduced agricultural output was experienced coupled with growing population and dropping in the availability of per-capita energy, and to deal with these issues the Empire responded by capturing the neighboring empires where there were energy surpluses and other supplies like metal, grains, and human labor. This did not solve the problem in the long run because the Roman Empire expanded more and bigger challenges such as escalating costs related to communications, army, and civil governments and also crop failure became massive. Now, these challenges could no longer be dealt with by the same method of conquering more neighboring territories because that would make the problems even bigger. Efforts by Domitian and Constantine the Great to maintain cohesion within the empire through authoritarian means failed because it only strained the population more and eventually led to the breaking of the empire into two territories, east and west splits, and overtime, the west broke further into smaller units. The eastern split, though did not get fragmented immediately because it was able to capture some weak neighboring territories, would later and slowly crumble. The crumbling of the West Roman Empire was catastrophic and which Tainter argues that was the preference of the majority of everyone involved. The collapsing of West Roman Empire is a case where it is demonstrated that “complexity of the society” could no longer be sustained as would be established by Tainter's "Diminishing Return of Complexity". This gained the support of Ugo Bardi, Sara Falsini, and Ilaria Perissi's study "Toward a General Theory of Societal Collapse. A Biophysical Examination of Tainter’s Model of the Diminishing Returns of Complexity" which related Tainter's model of collapsing of complex societies to a model they called socioeconomic system model. Further support of Tainter's Model of the "Diminishing Returns of Complexity" could be ascribed Curtis (2012)’s "population-resources framework". In the framework, the collapsing of societies in the pre-industrial was related to societies' "failure to combat the destabilizing effects of demographic pressure on an (often) finite pool of resources, which put the future sustainability of settlements in danger" (pg. 18). See also References |
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[SOURCE: https://en.wikipedia.org/wiki/OpenAI#cite_note-103] | [TOKENS: 8773] |
Contents OpenAI OpenAI is an American artificial intelligence research organization comprising both a non-profit foundation and a controlled for-profit public benefit corporation (PBC), headquartered in San Francisco. It aims to develop "safe and beneficial" artificial general intelligence (AGI), which it defines as "highly autonomous systems that outperform humans at most economically valuable work". OpenAI is widely recognized for its development of the GPT family of large language models, the DALL-E series of text-to-image models, and the Sora series of text-to-video models, which have influenced industry research and commercial applications. Its release of ChatGPT in November 2022 has been credited with catalyzing widespread interest in generative AI. The organization was founded in 2015 in Delaware but evolved a complex corporate structure. As of October 2025, following restructuring approved by California and Delaware regulators, the non-profit OpenAI Foundation holds 26% of the for-profit OpenAI Group PBC, with Microsoft holding 27% and employees/other investors holding 47%. Under its governance arrangements, the OpenAI Foundation holds the authority to appoint the board of the for-profit OpenAI Group PBC, a mechanism designed to align the entity’s strategic direction with the Foundation’s charter. Microsoft previously invested over $13 billion into OpenAI, and provides Azure cloud computing resources. In October 2025, OpenAI conducted a $6.6 billion share sale that valued the company at $500 billion. In 2023 and 2024, OpenAI faced multiple lawsuits for alleged copyright infringement against authors and media companies whose work was used to train some of OpenAI's products. In November 2023, OpenAI's board removed Sam Altman as CEO, citing a lack of confidence in him, but reinstated him five days later following a reconstruction of the board. Throughout 2024, roughly half of then-employed AI safety researchers left OpenAI, citing the company's prominent role in an industry-wide problem. Founding In December 2015, OpenAI was founded as a not for profit organization by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, Trevor Blackwell, Vicki Cheung, Andrej Karpathy, Durk Kingma, John Schulman, Pamela Vagata, and Wojciech Zaremba, with Sam Altman and Elon Musk as the co-chairs. A total of $1 billion in capital was pledged by Sam Altman, Greg Brockman, Elon Musk, Reid Hoffman, Jessica Livingston, Peter Thiel, Amazon Web Services (AWS), and Infosys. However, the actual capital collected significantly lagged pledges. According to company disclosures, only $130 million had been received by 2019. In its founding charter, OpenAI stated an intention to collaborate openly with other institutions by making certain patents and research publicly available, but later restricted access to its most capable models, citing competitive and safety concerns. OpenAI was initially run from Brockman's living room. It was later headquartered at the Pioneer Building in the Mission District, San Francisco. According to OpenAI's charter, its founding mission is "to ensure that artificial general intelligence (AGI)—by which we mean highly autonomous systems that outperform humans at most economically valuable work—benefits all of humanity." Musk and Altman stated in 2015 that they were partly motivated by concerns about AI safety and existential risk from artificial general intelligence. OpenAI stated that "it's hard to fathom how much human-level AI could benefit society", and that it is equally difficult to comprehend "how much it could damage society if built or used incorrectly". The startup also wrote that AI "should be an extension of individual human wills and, in the spirit of liberty, as broadly and evenly distributed as possible", and that "because of AI's surprising history, it's hard to predict when human-level AI might come within reach. When it does, it'll be important to have a leading research institution which can prioritize a good outcome for all over its own self-interest." Co-chair Sam Altman expected a decades-long project that eventually surpasses human intelligence. Brockman met with Yoshua Bengio, one of the "founding fathers" of deep learning, and drew up a list of great AI researchers. Brockman was able to hire nine of them as the first employees in December 2015. OpenAI did not pay AI researchers salaries comparable to those of Facebook or Google. It also did not pay stock options which AI researchers typically get. Nevertheless, OpenAI spent $7 million on its first 52 employees in 2016. OpenAI's potential and mission drew these researchers to the firm; a Google employee said he was willing to leave Google for OpenAI "partly because of the very strong group of people and, to a very large extent, because of its mission." OpenAI co-founder Wojciech Zaremba stated that he turned down "borderline crazy" offers of two to three times his market value to join OpenAI instead. In April 2016, OpenAI released a public beta of "OpenAI Gym", its platform for reinforcement learning research. Nvidia gifted its first DGX-1 supercomputer to OpenAI in August 2016 to help it train larger and more complex AI models with the capability of reducing processing time from six days to two hours. In December 2016, OpenAI released "Universe", a software platform for measuring and training an AI's general intelligence across the world's supply of games, websites, and other applications. Corporate structure In 2019, OpenAI transitioned from non-profit to "capped" for-profit, with the profit being capped at 100 times any investment. According to OpenAI, the capped-profit model allows OpenAI Global, LLC to legally attract investment from venture funds and, in addition, to grant employees stakes in the company. Many top researchers work for Google Brain, DeepMind, or Facebook, which offer equity that a nonprofit would be unable to match. Before the transition, OpenAI was legally required to publicly disclose the compensation of its top employees. The company then distributed equity to its employees and partnered with Microsoft, announcing an investment package of $1 billion into the company. Since then, OpenAI systems have run on an Azure-based supercomputing platform from Microsoft. OpenAI Global, LLC then announced its intention to commercially license its technologies. It planned to spend $1 billion "within five years, and possibly much faster". Altman stated that even a billion dollars may turn out to be insufficient, and that the lab may ultimately need "more capital than any non-profit has ever raised" to achieve artificial general intelligence. The nonprofit, OpenAI, Inc., is the sole controlling shareholder of OpenAI Global, LLC, which, despite being a for-profit company, retains a formal fiduciary responsibility to OpenAI, Inc.'s nonprofit charter. A majority of OpenAI, Inc.'s board is barred from having financial stakes in OpenAI Global, LLC. In addition, minority members with a stake in OpenAI Global, LLC are barred from certain votes due to conflict of interest. Some researchers have argued that OpenAI Global, LLC's switch to for-profit status is inconsistent with OpenAI's claims to be "democratizing" AI. On February 29, 2024, Elon Musk filed a lawsuit against OpenAI and CEO Sam Altman, accusing them of shifting focus from public benefit to profit maximization—a case OpenAI dismissed as "incoherent" and "frivolous," though Musk later revived legal action against Altman and others in August. On April 9, 2024, OpenAI countersued Musk in federal court, alleging that he had engaged in "bad-faith tactics" to slow the company's progress and seize its innovations for his personal benefit. OpenAI also argued that Musk had previously supported the creation of a for-profit structure and had expressed interest in controlling OpenAI himself. The countersuit seeks damages and legal measures to prevent further alleged interference. On February 10, 2025, a consortium of investors led by Elon Musk submitted a $97.4 billion unsolicited bid to buy the nonprofit that controls OpenAI, declaring willingness to match or exceed any better offer. The offer was rejected on 14 February 2025, with OpenAI stating that it was not for sale, but the offer complicated Altman's restructuring plan by suggesting a lower bar for how much the nonprofit should be valued. OpenAI, Inc. was originally designed as a nonprofit in order to ensure that AGI "benefits all of humanity" rather than "the private gain of any person". In 2019, it created OpenAI Global, LLC, a capped-profit subsidiary controlled by the nonprofit. In December 2024, OpenAI proposed a restructuring plan to convert the capped-profit into a Delaware-based public benefit corporation (PBC), and to release it from the control of the nonprofit. The nonprofit would sell its control and other assets, getting equity in return, and would use it to fund and pursue separate charitable projects, including in science and education. OpenAI's leadership described the change as necessary to secure additional investments, and claimed that the nonprofit's founding mission to ensure AGI "benefits all of humanity" would be better fulfilled. The plan has been criticized by former employees. A legal letter named "Not For Private Gain" asked the attorneys general of California and Delaware to intervene, stating that the restructuring is illegal and would remove governance safeguards from the nonprofit and the attorneys general. The letter argues that OpenAI's complex structure was deliberately designed to remain accountable to its mission, without the conflicting pressure of maximizing profits. It contends that the nonprofit is best positioned to advance its mission of ensuring AGI benefits all of humanity by continuing to control OpenAI Global, LLC, whatever the amount of equity that it could get in exchange. PBCs can choose how they balance their mission with profit-making. Controlling shareholders have a large influence on how closely a PBC sticks to its mission. On October 28, 2025, OpenAI announced that it had adopted the new PBC corporate structure after receiving approval from the attorneys general of California and Delaware. Under the new structure, OpenAI's for-profit branch became a public benefit corporation known as OpenAI Group PBC, while the non-profit was renamed to the OpenAI Foundation. The OpenAI Foundation holds a 26% stake in the PBC, while Microsoft holds a 27% stake and the remaining 47% is owned by employees and other investors. All members of the OpenAI Group PBC board of directors will be appointed by the OpenAI Foundation, which can remove them at any time. Members of the Foundation's board will also serve on the for-profit board. The new structure allows the for-profit PBC to raise investor funds like most traditional tech companies, including through an initial public offering, which Altman claimed was the most likely path forward. In January 2023, OpenAI Global, LLC was in talks for funding that would value the company at $29 billion, double its 2021 value. On January 23, 2023, Microsoft announced a new US$10 billion investment in OpenAI Global, LLC over multiple years, partially needed to use Microsoft's cloud-computing service Azure. From September to December, 2023, Microsoft rebranded all variants of its Copilot to Microsoft Copilot, and they added MS-Copilot to many installations of Windows and released Microsoft Copilot mobile apps. Following OpenAI's 2025 restructuring, Microsoft owns a 27% stake in the for-profit OpenAI Group PBC, valued at $135 billion. In a deal announced the same day, OpenAI agreed to purchase $250 billion of Azure services, with Microsoft ceding their right of first refusal over OpenAI's future cloud computing purchases. As part of the deal, OpenAI will continue to share 20% of its revenue with Microsoft until it achieves AGI, which must now be verified by an independent panel of experts. The deal also loosened restrictions on both companies working with third parties, allowing Microsoft to pursue AGI independently and allowing OpenAI to develop products with other companies. In 2017, OpenAI spent $7.9 million, a quarter of its functional expenses, on cloud computing alone. In comparison, DeepMind's total expenses in 2017 were $442 million. In the summer of 2018, training OpenAI's Dota 2 bots required renting 128,000 CPUs and 256 GPUs from Google for multiple weeks. In October 2024, OpenAI completed a $6.6 billion capital raise with a $157 billion valuation including investments from Microsoft, Nvidia, and SoftBank. On January 21, 2025, Donald Trump announced The Stargate Project, a joint venture between OpenAI, Oracle, SoftBank and MGX to build an AI infrastructure system in conjunction with the US government. The project takes its name from OpenAI's existing "Stargate" supercomputer project and is estimated to cost $500 billion. The partners planned to fund the project over the next four years. In July, the United States Department of Defense announced that OpenAI had received a $200 million contract for AI in the military, along with Anthropic, Google, and xAI. In the same month, the company made a deal with the UK Government to use ChatGPT and other AI tools in public services. OpenAI subsequently began a $50 million fund to support nonprofit and community organizations. In April 2025, OpenAI raised $40 billion at a $300 billion post-money valuation, which was the highest-value private technology deal in history. The financing round was led by SoftBank, with other participants including Microsoft, Coatue, Altimeter and Thrive. In July 2025, the company reported annualized revenue of $12 billion. This was an increase from $3.7 billion in 2024, which was driven by ChatGPT subscriptions, which reached 20 million paid subscribers by April 2025, up from 15.5 million at the end of 2024, alongside a rapidly expanding enterprise customer base that grew to five million business users. The company’s cash burn remains high because of the intensive computational costs required to train and operate large language models. It projects an $8 billion operating loss in 2025. OpenAI reports revised long-term spending projections totaling approximately $115 billion through 2029, with annual expenditures projected to escalate significantly, reaching $17 billion in 2026, $35 billion in 2027, and $45 billion in 2028. These expenditures are primarily allocated toward expanding compute infrastructure, developing proprietary AI chips, constructing data centers, and funding intensive model training programs, with more than half of the spending through the end of the decade expected to support research-intensive compute for model training and development. The company's financial strategy prioritizes market expansion and technological advancement over near-term profitability, with OpenAI targeting cash-flow-positive operations by 2029 and projecting revenue of approximately $200 billion by 2030. This aggressive spending trajectory underscores both the enormous capital requirements of scaling cutting-edge AI technology and OpenAI's commitment to maintaining its position as a leader in the artificial intelligence industry. In October 2025, OpenAI completed an employee share sale of up to $10 billion to existing investors which valued the company at $500 billion. The deal values OpenAI as the most valuable privately owned company in the world—surpassing SpaceX as the world's most valuable private company. On November 17, 2023, Sam Altman was removed as CEO when its board of directors (composed of Helen Toner, Ilya Sutskever, Adam D'Angelo and Tasha McCauley) cited a lack of confidence in him. Chief Technology Officer Mira Murati took over as interim CEO. Greg Brockman, the president of OpenAI, was also removed as chairman of the board and resigned from the company's presidency shortly thereafter. Three senior OpenAI researchers subsequently resigned: director of research and GPT-4 lead Jakub Pachocki, head of AI risk Aleksander Mądry, and researcher Szymon Sidor. On November 18, 2023, there were reportedly talks of Altman returning as CEO amid pressure placed upon the board by investors such as Microsoft and Thrive Capital, who objected to Altman's departure. Although Altman himself spoke in favor of returning to OpenAI, he has since stated that he considered starting a new company and bringing former OpenAI employees with him if talks to reinstate him didn't work out. The board members agreed "in principle" to resign if Altman returned. On November 19, 2023, negotiations with Altman to return failed and Murati was replaced by Emmett Shear as interim CEO. The board initially contacted Anthropic CEO Dario Amodei (a former OpenAI executive) about replacing Altman, and proposed a merger of the two companies, but both offers were declined. On November 20, 2023, Microsoft CEO Satya Nadella announced Altman and Brockman would be joining Microsoft to lead a new advanced AI research team, but added that they were still committed to OpenAI despite recent events. Before the partnership with Microsoft was finalized, Altman gave the board another opportunity to negotiate with him. About 738 of OpenAI's 770 employees, including Murati and Sutskever, signed an open letter stating they would quit their jobs and join Microsoft if the board did not rehire Altman and then resign. This prompted OpenAI investors to consider legal action against the board as well. In response, OpenAI management sent an internal memo to employees stating that negotiations with Altman and the board had resumed and would take some time. On November 21, 2023, after continued negotiations, Altman and Brockman returned to the company in their prior roles along with a reconstructed board made up of new members Bret Taylor (as chairman) and Lawrence Summers, with D'Angelo remaining. According to subsequent reporting, shortly before Altman’s firing, some employees raised concerns to the board about how he had handled the safety implications of a recent internal AI capability discovery. On November 29, 2023, OpenAI announced that an anonymous Microsoft employee had joined the board as a non-voting member to observe the company's operations; Microsoft resigned from the board in July 2024. In February 2024, the Securities and Exchange Commission subpoenaed OpenAI's internal communication to determine if Altman's alleged lack of candor misled investors. In 2024, following the temporary removal of Sam Altman and his return, many employees gradually left OpenAI, including most of the original leadership team and a significant number of AI safety researchers. In August 2023, it was announced that OpenAI had acquired the New York-based start-up Global Illumination, a company that deploys AI to develop digital infrastructure and creative tools. In June 2024, OpenAI acquired Multi, a startup focused on remote collaboration. In March 2025, OpenAI reached a deal with CoreWeave to acquire $350 million worth of CoreWeave shares and access to AI infrastructure, in return for $11.9 billion paid over five years. Microsoft was already CoreWeave's biggest customer in 2024. Alongside their other business dealings, OpenAI and Microsoft were renegotiating the terms of their partnership to facilitate a potential future initial public offering by OpenAI, while ensuring Microsoft's continued access to advanced AI models. On May 21, OpenAI announced the $6.5 billion acquisition of io, an AI hardware start-up founded by former Apple designer Jony Ive in 2024. In September 2025, OpenAI agreed to acquire the product testing startup Statsig for $1.1 billion in an all-stock deal and appointed Statsig's founding CEO Vijaye Raji as OpenAI's chief technology officer of applications. The company also announced development of an AI-driven hiring service designed to rival LinkedIn. OpenAI acquired personal finance app Roi in October 2025. In October 2025, OpenAI acquired Software Applications Incorporated, the developer of Sky, a macOS-based natural language interface designed to operate across desktop applications. The Sky team joined OpenAI, and the company announced plans to integrate Sky’s capabilities into ChatGPT. In December 2025, it was announced OpenAI had agreed to acquire Neptune, an AI tooling startup that helps companies track and manage model training, for an undisclosed amount. In January 2026, it was announced OpenAI had acquired healthcare technology startup Torch for approximately $60 million. The acquisition followed the launch of OpenAI’s ChatGPT Health product and was intended to strengthen the company’s medical data and healthcare artificial intelligence capabilities. OpenAI has been criticized for outsourcing the annotation of data sets to Sama, a company based in San Francisco that employed workers in Kenya. These annotations were used to train an AI model to detect toxicity, which could then be used to moderate toxic content, notably from ChatGPT's training data and outputs. However, these pieces of text usually contained detailed descriptions of various types of violence, including sexual violence. The investigation uncovered that OpenAI began sending snippets of data to Sama as early as November 2021. The four Sama employees interviewed by Time described themselves as mentally scarred. OpenAI paid Sama $12.50 per hour of work, and Sama was redistributing the equivalent of between $1.32 and $2.00 per hour post-tax to its annotators. Sama's spokesperson said that the $12.50 was also covering other implicit costs, among which were infrastructure expenses, quality assurance and management. In 2024, OpenAI began collaborating with Broadcom to design a custom AI chip capable of both training and inference, targeted for mass production in 2026 and to be manufactured by TSMC on a 3 nm process node. This initiative intended to reduce OpenAI's dependence on Nvidia GPUs, which are costly and face high demand in the market. In January 2024, Arizona State University purchased ChatGPT Enterprise in OpenAI's first deal with a university. In June 2024, Apple Inc. signed a contract with OpenAI to integrate ChatGPT features into its products as part of its new Apple Intelligence initiative. In June 2025, OpenAI began renting Google Cloud's Tensor Processing Units (TPUs) to support ChatGPT and related services, marking its first meaningful use of non‑Nvidia AI chips. In September 2025, it was revealed that OpenAI signed a contract with Oracle to purchase $300 billion in computing power over the next five years. In September 2025, OpenAI and NVIDIA announced a memorandum of understanding that included a potential deployment of at least 10 gigawatts of NVIDIA systems and a $100 billion investment from NVIDIA in OpenAI. OpenAI expected the negotiations to be completed within weeks. As of January 2026, this has not been realized, and the two sides are rethinking the future of their partnership. In October 2025, OpenAI announced a multi-billion dollar deal with AMD. OpenAI committed to purchasing six gigawatts worth of AMD chips, starting with the MI450. OpenAI will have the option to buy up to 160 million shares of AMD, about 10% of the company, depending on development, performance and share price targets. In December 2025, Disney said it would make a $1 billion investment in OpenAI, and signed a three-year licensing deal that will let users generate videos using Sora—OpenAI's short-form AI video platform. More than 200 Disney, Marvel, Star Wars and Pixar characters will be available to OpenAI users. In early 2026, Amazon entered advanced discussions to invest up to $50 billion in OpenAI as part of a potential artificial intelligence partnership. Under the proposed agreement, OpenAI’s models could be integrated into Amazon’s digital assistant Alexa and other internal projects. OpenAI provides LLMs to the Artificial Intelligence Cyber Challenge and to the Advanced Research Projects Agency for Health. In October 2024, The Intercept revealed that OpenAI's tools are considered "essential" for AFRICOM's mission and included in an "Exception to Fair Opportunity" contractual agreement between the United States Department of Defense and Microsoft. In December 2024, OpenAI said it would partner with defense-tech company Anduril to build drone defense technologies for the United States and its allies. In 2025, OpenAI's Chief Product Officer, Kevin Weil, was commissioned lieutenant colonel in the U.S. Army to join Detachment 201 as senior advisor. In June 2025, the U.S. Department of Defense awarded OpenAI a $200 million one-year contract to develop AI tools for military and national security applications. OpenAI announced a new program, OpenAI for Government, to give federal, state, and local governments access to its models, including ChatGPT. Services In February 2019, GPT-2 was announced, which gained attention for its ability to generate human-like text. In 2020, OpenAI announced GPT-3, a language model trained on large internet datasets. GPT-3 is aimed at natural language answering questions, but it can also translate between languages and coherently generate improvised text. It also announced that an associated API, named the API, would form the heart of its first commercial product. Eleven employees left OpenAI, mostly between December 2020 and January 2021, in order to establish Anthropic. In 2021, OpenAI introduced DALL-E, a specialized deep learning model adept at generating complex digital images from textual descriptions, utilizing a variant of the GPT-3 architecture. In December 2022, OpenAI received widespread media coverage after launching a free preview of ChatGPT, its new AI chatbot based on GPT-3.5. According to OpenAI, the preview received over a million signups within the first five days. According to anonymous sources cited by Reuters in December 2022, OpenAI Global, LLC was projecting $200 million of revenue in 2023 and $1 billion in revenue in 2024. After ChatGPT was launched, Google announced a similar chatbot, Bard, amid internal concerns that ChatGPT could threaten Google’s position as a primary source of online information. On February 7, 2023, Microsoft announced that it was building AI technology based on the same foundation as ChatGPT into Microsoft Bing, Edge, Microsoft 365 and other products. On March 14, 2023, OpenAI released GPT-4, both as an API (with a waitlist) and as a feature of ChatGPT Plus. On November 6, 2023, OpenAI launched GPTs, allowing individuals to create customized versions of ChatGPT for specific purposes, further expanding the possibilities of AI applications across various industries. On November 14, 2023, OpenAI announced they temporarily suspended new sign-ups for ChatGPT Plus due to high demand. Access for newer subscribers re-opened a month later on December 13. In December 2024, the company launched the Sora model. It also launched OpenAI o1, an early reasoning model that was internally codenamed strawberry. Additionally, ChatGPT Pro—a $200/month subscription service offering unlimited o1 access and enhanced voice features—was introduced, and preliminary benchmark results for the upcoming OpenAI o3 models were shared. On January 23, 2025, OpenAI released Operator, an AI agent and web automation tool for accessing websites to execute goals defined by users. The feature was only available to Pro users in the United States. OpenAI released deep research agent, nine days later. It scored a 27% accuracy on the benchmark Humanity's Last Exam (HLE). Altman later stated GPT-4.5 would be the last model without full chain-of-thought reasoning. In July 2025, reports indicated that AI models by both OpenAI and Google DeepMind solved mathematics problems at the level of top-performing students in the International Mathematical Olympiad. OpenAI's large language model was able to achieve gold medal-level performance, reflecting significant progress in AI's reasoning abilities. On October 6, 2025, OpenAI unveiled its Agent Builder platform during the company's DevDay event. The platform includes a visual drag-and-drop interface that lets developers and businesses design, test, and deploy agentic workflows with limited coding. On October 21, 2025, OpenAI introduced ChatGPT Atlas, a browser integrating the ChatGPT assistant directly into web navigation, to compete with existing browsers such as Google Chrome and Apple Safari. On December 11, 2025, OpenAI announced GPT-5.2. This model will be better at creating spreadsheets, building presentations, perceiving images, writing code and understanding long context. On January 27, 2026, OpenAI introduced Prism, a LaTeX-native workspace meant to assist scientists to help with research and writing. The platform utilizes GPT-5.2 as a backend to automate the process of drafting for scientific papers, including features for managing citations, complex equation formatting, and real-time collaborative editing. In March 2023, the company was criticized for disclosing particularly few technical details about products like GPT-4, contradicting its initial commitment to openness and making it harder for independent researchers to replicate its work and develop safeguards. OpenAI cited competitiveness and safety concerns to justify this repudiation. OpenAI's former chief scientist Ilya Sutskever argued in 2023 that open-sourcing increasingly capable models was increasingly risky, and that the safety reasons for not open-sourcing the most potent AI models would become "obvious" in a few years. In September 2025, OpenAI published a study on how people use ChatGPT for everyday tasks. The study found that "non-work tasks" (according to an LLM-based classifier) account for more than 72 percent of all ChatGPT usage, with a minority of overall usage related to business productivity. In July 2023, OpenAI launched the superalignment project, aiming within four years to determine how to align future superintelligent systems. OpenAI promised to dedicate 20% of its computing resources to the project, although the team denied receiving anything close to 20%. OpenAI ended the project in May 2024 after its co-leaders Ilya Sutskever and Jan Leike left the company. In August 2025, OpenAI was criticized after thousands of private ChatGPT conversations were inadvertently exposed to public search engines like Google due to an experimental "share with search engines" feature. The opt-in toggle, intended to allow users to make specific chats discoverable, resulted in some discussions including personal details such as names, locations, and intimate topics appearing in search results when users accidentally enabled it while sharing links. OpenAI announced the feature's permanent removal on August 1, 2025, and the company began coordinating with search providers to remove the exposed content, emphasizing that it was not a security breach but a design flaw that heightened privacy risks. CEO Sam Altman acknowledged the issue in a podcast, noting users often treat ChatGPT as a confidant for deeply personal matters, which amplified concerns about AI handling sensitive data. Management In 2018, Musk resigned from his Board of Directors seat, citing "a potential future conflict [of interest]" with his role as CEO of Tesla due to Tesla's AI development for self-driving cars. OpenAI stated that Musk's financial contributions were below $45 million. On March 3, 2023, Reid Hoffman resigned from his board seat, citing a desire to avoid conflicts of interest with his investments in AI companies via Greylock Partners, and his co-founding of the AI startup Inflection AI. Hoffman remained on the board of Microsoft, a major investor in OpenAI. In May 2024, Chief Scientist Ilya Sutskever resigned and was succeeded by Jakub Pachocki. Co-leader Jan Leike also departed amid concerns over safety and trust. OpenAI then signed deals with Reddit, News Corp, Axios, and Vox Media. Paul Nakasone then joined the board of OpenAI. In August 2024, cofounder John Schulman left OpenAI to join Anthropic, and OpenAI's president Greg Brockman took extended leave until November. In September 2024, CTO Mira Murati left the company. In November 2025, Lawrence Summers resigned from the board of directors. Governance and legal issues In May 2023, Sam Altman, Greg Brockman and Ilya Sutskever posted recommendations for the governance of superintelligence. They stated that superintelligence could happen within the next 10 years, allowing a "dramatically more prosperous future" and that "given the possibility of existential risk, we can't just be reactive". They proposed creating an international watchdog organization similar to IAEA to oversee AI systems above a certain capability threshold, suggesting that relatively weak AI systems on the other side should not be overly regulated. They also called for more technical safety research for superintelligences, and asked for more coordination, for example through governments launching a joint project which "many current efforts become part of". In July 2023, the FTC issued a civil investigative demand to OpenAI to investigate whether the company's data security and privacy practices to develop ChatGPT were unfair or harmed consumers (including by reputational harm) in violation of Section 5 of the Federal Trade Commission Act of 1914. These are typically preliminary investigative matters and are nonpublic, but the FTC's document was leaked. In July 2023, the FTC launched an investigation into OpenAI over allegations that the company scraped public data and published false and defamatory information. They asked OpenAI for comprehensive information about its technology and privacy safeguards, as well as any steps taken to prevent the recurrence of situations in which its chatbot generated false and derogatory content about people. The agency also raised concerns about ‘circular’ spending arrangements—for example, Microsoft extending Azure credits to OpenAI while both companies shared engineering talent—and warned that such structures could negatively affect the public. In September 2024, OpenAI's global affairs chief endorsed the UK's "smart" AI regulation during testimony to a House of Lords committee. In February 2025, OpenAI CEO Sam Altman stated that the company is interested in collaborating with the People's Republic of China, despite regulatory restrictions imposed by the U.S. government. This shift comes in response to the growing influence of the Chinese artificial intelligence company DeepSeek, which has disrupted the AI market with open models, including DeepSeek V3 and DeepSeek R1. Following DeepSeek's market emergence, OpenAI enhanced security protocols to protect proprietary development techniques from industrial espionage. Some industry observers noted similarities between DeepSeek's model distillation approach and OpenAI's methodology, though no formal intellectual property claim was filed. According to Oliver Roberts, in March 2025, the United States had 781 state AI bills or laws. OpenAI advocated for preempting state AI laws with federal laws. According to Scott Kohler, OpenAI has opposed California's AI legislation and suggested that the state bill encroaches on a more competent federal government. Public Citizen opposed a federal preemption on AI and pointed to OpenAI's growth and valuation as evidence that existing state laws have not hampered innovation. Before May 2024, OpenAI required departing employees to sign a lifelong non-disparagement agreement forbidding them from criticizing OpenAI and acknowledging the existence of the agreement. Daniel Kokotajlo, a former employee, publicly stated that he forfeited his vested equity in OpenAI in order to leave without signing the agreement. Sam Altman stated that he was unaware of the equity cancellation provision, and that OpenAI never enforced it to cancel any employee's vested equity. However, leaked documents and emails refute this claim. On May 23, 2024, OpenAI sent a memo releasing former employees from the agreement. OpenAI was sued for copyright infringement by authors Sarah Silverman, Matthew Butterick, Paul Tremblay and Mona Awad in July 2023. In September 2023, 17 authors, including George R. R. Martin, John Grisham, Jodi Picoult and Jonathan Franzen, joined the Authors Guild in filing a class action lawsuit against OpenAI, alleging that the company's technology was illegally using their copyrighted work. The New York Times also sued the company in late December 2023. In May 2024 it was revealed that OpenAI had destroyed its Books1 and Books2 training datasets, which were used in the training of GPT-3, and which the Authors Guild believed to have contained over 100,000 copyrighted books. In 2021, OpenAI developed a speech recognition tool called Whisper. OpenAI used it to transcribe more than one million hours of YouTube videos into text for training GPT-4. The automated transcription of YouTube videos raised concerns within OpenAI employees regarding potential violations of YouTube's terms of service, which prohibit the use of videos for applications independent of the platform, as well as any type of automated access to its videos. Despite these concerns, the project proceeded with notable involvement from OpenAI's president, Greg Brockman. The resulting dataset proved instrumental in training GPT-4. In February 2024, The Intercept as well as Raw Story and Alternate Media Inc. filed lawsuit against OpenAI on copyright litigation ground. The lawsuit is said to have charted a new legal strategy for digital-only publishers to sue OpenAI. On April 30, 2024, eight newspapers filed a lawsuit in the Southern District of New York against OpenAI and Microsoft, claiming illegal harvesting of their copyrighted articles. The suing publications included The Mercury News, The Denver Post, The Orange County Register, St. Paul Pioneer Press, Chicago Tribune, Orlando Sentinel, Sun Sentinel, and New York Daily News. In June 2023, a lawsuit claimed that OpenAI scraped 300 billion words online without consent and without registering as a data broker. It was filed in San Francisco, California, by sixteen anonymous plaintiffs. They also claimed that OpenAI and its partner as well as customer Microsoft continued to unlawfully collect and use personal data from millions of consumers worldwide to train artificial intelligence models. On May 22, 2024, OpenAI entered into an agreement with News Corp to integrate news content from The Wall Street Journal, the New York Post, The Times, and The Sunday Times into its AI platform. Meanwhile, other publications like The New York Times chose to sue OpenAI and Microsoft for copyright infringement over the use of their content to train AI models. In November 2024, a coalition of Canadian news outlets, including the Toronto Star, Metroland Media, Postmedia, The Globe and Mail, The Canadian Press and CBC, sued OpenAI for using their news articles to train its software without permission. In October 2024 during a New York Times interview, Suchir Balaji accused OpenAI of violating copyright law in developing its commercial LLMs which he had helped engineer. He was a likely witness in a major copyright trial against the AI company, and was one of several of its current or former employees named in court filings as potentially having documents relevant to the case. On November 26, 2024, Balaji died by suicide. His death prompted the circulation of conspiracy theories alleging that he had been deliberately silenced. California Congressman Ro Khanna endorsed calls for an investigation. On April 24, 2025, Ziff Davis sued OpenAI in Delaware federal court for copyright infringement. Ziff Davis is known for publications such as ZDNet, PCMag, CNET, IGN and Lifehacker. In April 2023, the EU's European Data Protection Board (EDPB) formed a dedicated task force on ChatGPT "to foster cooperation and to exchange information on possible enforcement actions conducted by data protection authorities" based on the "enforcement action undertaken by the Italian data protection authority against OpenAI about the ChatGPT service". In late April 2024 NOYB filed a complaint with the Austrian Datenschutzbehörde against OpenAI for violating the European General Data Protection Regulation. A text created with ChatGPT gave a false date of birth for a living person without giving the individual the option to see the personal data used in the process. A request to correct the mistake was denied. Additionally, neither the recipients of ChatGPT's work nor the sources used, could be made available, OpenAI claimed. OpenAI was criticized for lifting its ban on using ChatGPT for "military and warfare". Up until January 10, 2024, its "usage policies" included a ban on "activity that has high risk of physical harm, including", specifically, "weapons development" and "military and warfare". Its new policies prohibit "[using] our service to harm yourself or others" and to "develop or use weapons". In August 2025, the parents of a 16-year-old boy who died by suicide filed a wrongful death lawsuit against OpenAI (and CEO Sam Altman), alleging that months of conversations with ChatGPT about mental health and methods of self-harm contributed to their son's death and that safeguards were inadequate for minors. OpenAI expressed condolences and said it was strengthening protections (including updated crisis response behavior and parental controls). Coverage described it as a first-of-its-kind wrongful death case targeting the company's chatbot. The complaint was filed in California state court in San Francisco. In November 2025, the Social Media Victims Law Center and Tech Justice Law Project filed seven lawsuits against OpenAI, of which four lawsuits alleged wrongful death. The suits were filed on behalf of Zane Shamblin, 23, of Texas; Amaurie Lacey, 17, of Georgia; Joshua Enneking, 26, of Florida; and Joe Ceccanti, 48, of Oregon, who each committed suicide after prolonged ChatGPT usage. In December 2025, Stein-Erik Soelberg, who was 56 years old at the time, allegedly murdered his mother Suzanne Adams. In the months prior the paranoid, delusional man often discussed his ideas with ChatGPT. Adam's estate then sued OpenAI claiming that the company shared responsibility due to the risk of chatbot psychosis despite the fact that chatbot psychosis is not a real medical diagnosis. OpenAI responded saying they will make ChatGPT safer for users disconnected from reality. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Myst_Online:_Uru_Live] | [TOKENS: 1866] |
Contents Myst Online: Uru Live Myst Online: Uru Live is an open source massively multiplayer online adventure game developed by Cyan Worlds. The game is the multiplayer component to the 2003 video game Uru: Ages Beyond Myst. Like Uru, Myst Online takes place in 2000s New Mexico, where an ancient civilization known as the D'ni once thrived. The D'ni had the ability to create portals to other worlds or Ages by writing descriptive books of the Age. Players uncover clues and solve puzzles together; plot developments were added via episodic content updates. Uru's multiplayer segment was delayed and only shipped with the single-player component initially; in February 2004 the multiplayer was scrapped entirely. Dedicated fans kept an unsupported version of the game alive through Cyan-maintained servers. Online game distributor GameTap resurrected the game as Myst Online in 2007, but this version was canceled due to a lack of subscribers despite generally positive reviews. Cyan received the rights to Myst Online from GameTap and announced its intention to bring the game back. In 2010, Cyan Worlds released the game free of charge, under the name MO:ULagain, and later released Myst Online's client and 3ds Max plugin under the GNU GPL v3 license. Gameplay Myst Online's gameplay is a massively multiplayer online game, where players interact with others to solve puzzles and advance the story. Players communicate with others using a "Ki", an artifact which provides a special interface. Each player has their own personal Age, called Relto; unlike in public areas, each player's Relto is different depending on the player's tastes. In public areas, any action a player takes is persistent and remains part of that world — kick a stone in one player's game, for instance, and the stone will be moved when any other player enters the area. Myst Online takes place in fictitious caverns below Earth's surface. Thousands of years ago, a race known as the D'ni practiced a craft known as The Art. By writing special books describing a location, the D'ni created a link to that world. The D'ni had their own number system and language distinct from the humans dwelling above them. According to the story, archeologists much later discovered the caverns and teamed with a development studio (Cyan Worlds) to produce educational video games based on their findings; thus, the story in the Myst games is canonically findings from the caverns. New content and additions to the story were revealed through "episodes". Development After completing Riven—the sequel to the bestselling Myst—in 1997, developer Rand Miller and his company, Cyan Worlds, began development of what would become Uru: Ages Beyond Myst. Initially, the game was to have been called Myst Online and have been a multiplayer-only title, but game publisher Ubisoft pushed for a single-player dimension. The online component, called Uru Live, did not ship with Ages Beyond Myst; in 2004, Uru Live was suspended entirely. In 2006, Cyan developed a stand-in for Uru Live, called Until Uru; this replacement was hosted by players in servers known as "shards", and did not have content updates or official support. On May 9, 2006, Cyan Worlds and GameTap announced at the Electronic Entertainment Expo that Myst Online: Uru Live would be returning in the holiday season of 2006. The GameTap version did not require any physical purchase: all the game content was downloaded through GameTap, which was subscribed to for a monthly fee. A major reason for the resurrection of the game was the fan support. According to GameTap's vice president of content Ricardo Sanchez, "One of the reasons [GameTap was] so attracted to Uru Live is that it had this persistent group that kept it alive during the dark days of it not being a product." Closed public beta testing of Myst Online: Uru Live began in August 2006. A period of semi-open beta testing lasted from December 12 to 18, 2006, with an open beta beginning on December 20. On January 18, 2007, it was announced that a Macintosh port of the game was being developed by TransGaming; a beta became available soon after. This coincided with the release of the first new Age, Eder Delin. GameTap brought Myst Online: Uru Live online in February 2007. On May 19, 2007, Myst Online made the move to episodic content releases, with each episode adding new Ages, puzzles, and a plot continuation. It was also released for Mac OS X, the first GameTap game for the platform. In February 2008, GameTap announced that Myst Online was canceled. Sanchez released a statement that "The decision was a very difficult one and was made for business reasons rather than due to any issues regarding the design and vision of the amazing world that Cyan Worlds and Rand Miller have brought to us. Despite the great Myst Online experience coming to a close, Cyan is still a very valued partner of GameTap, we are on excellent terms, and we look forward to continuing our relationship in the future." Various explanations for Uru Live's continuing troubles were given. Game designer Ernest Adams stated that "An important part of Myst's atmosphere came from being alone in a very strange place." Adams stated that the realities of online play distracted from the fantasy setting. When asked about the game's commercial failure, Miller responded: I'm always going to fall back on 'we were ahead of our time,' because it's easy. The biggest thing we did was an all or nothing proposal from an entertainment point of view. It's not like you can start up a new TV network and give one show a month and expect it to be successful ... We couldn't quite pull that off with the money we had." GameTap parent Turner Broadcasting's product development vice president Blake Lewin added that he did not believe any budget would have worked, due to the difficult content production pipeline. Lewin compared the game's production to the television series Lost, which had difficulties producing a full season. In an article discussing the current state of the adventure game genre, IGN writers Steve Butts and Charles Onyett considered the major issues with Myst Online that while a different kind of adventure game, Myst Online was not accessible to players other than the "hardcore faithful". The authors suggested that the franchise needed "to try something more dramatic than slapping an online architecture onto a game that already released, then periodically putting out small content updates." After several months of negotiations, Cyan regained the rights to Myst Online for no charge. Miller stated that Cyan was committed to resurrecting Myst Online once again, giving fans the chance to interact with and create content. The new version of Myst Online was dubbed the "Myst Online Restoration Experiment" or MORE, and Cyan planned to reopen the game on their own servers without new content; instead, tools would be released for fans to create new content. Cyan put forward a tentative outline, which started with Cyan running MORE servers, the restructuring of the MystOnline.com web site, the release of MORE tools to players, and the delegation of approving fan-made content given to groups known as "Guilds". The ultimate goal was a continuation of the storyline and new content, with or without fan aid. MORE was postponed after revenue to Cyan was disrupted and the company was forced to lay off all but seven employees in November 2008. The company announced that Myst Online's source code and tools would be given to the fans, making MORE an open-source project. On February 8, 2010, Cyan Worlds announced the return of Myst Online under the new title Myst Online: URU Live Again or MOULa. The game was made free to play, with donations contributing towards operating costs. The game was open-sourced, and Cyan released unfinished assets to the community, and starting in 2020 incorporated fan-made Ages as official content. Reception Myst Online was generally well received by critics. The game has average critic scores of 77% and 83% at aggregate sites Metacritic and GameRankings, respectively. The Ages' varied visuals and strong aesthetic design were praised, as were the ambient sounds and music. The world that persistently changes depending on player actions was also lauded as more sophisticated than other MMOs. Complaints from Uru: Ages Beyond Myst carried over to Myst Online; for example, Robert Washburne of JustAdventure found that the interface was still clunky. Charles Onyett of IGN said that those who had played through the previous Uru content would not find many changes: "As a result, Myst veterans uninterested in plugging through Uru's content again will be left with a dearth of things to actually do, shifting the onus of gameplay creation to the community." Onyett continued that the only reason to subscribe to the game was the dedicated fan community and the potential for the game to expand. Sarah Borger of GamesRadar noted that most puzzles could be completed without the help of other players, making the game "a pretty chat room". References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Python_(programming_language)#cite_note-The-Most-Controversial-Python-Walrus-Operator-72] | [TOKENS: 4314] |
Contents Python (programming language) Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically type-checked and garbage-collected. It supports multiple programming paradigms, including structured (particularly procedural), object-oriented and functional programming. Guido van Rossum began working on Python in the late 1980s as a successor to the ABC programming language. Python 3.0, released in 2008, was a major revision and not completely backward-compatible with earlier versions. Beginning with Python 3.5, capabilities and keywords for typing were added to the language, allowing optional static typing. As of 2026[update], the Python Software Foundation supports Python 3.10, 3.11, 3.12, 3.13, and 3.14, following the project's annual release cycle and five-year support policy. Python 3.15 is currently in the alpha development phase, and the stable release is expected to come out in October 2026. Earlier versions in the 3.x series have reached end-of-life and no longer receive security updates. Python has gained widespread use in the machine learning community. It is widely taught as an introductory programming language. Since 2003, Python has consistently ranked in the top ten of the most popular programming languages in the TIOBE Programming Community Index, which ranks based on searches in 24 platforms. History Python was conceived in the late 1980s by Guido van Rossum at Centrum Wiskunde & Informatica (CWI) in the Netherlands. It was designed as a successor to the ABC programming language, which was inspired by SETL, capable of exception handling and interfacing with the Amoeba operating system. Python implementation began in December 1989. Van Rossum first released it in 1991 as Python 0.9.0. Van Rossum assumed sole responsibility for the project, as the lead developer, until 12 July 2018, when he announced his "permanent vacation" from responsibilities as Python's "benevolent dictator for life" (BDFL); this title was bestowed on him by the Python community to reflect his long-term commitment as the project's chief decision-maker. (He has since come out of retirement and is self-titled "BDFL-emeritus".) In January 2019, active Python core developers elected a five-member Steering Council to lead the project. The name Python derives from the British comedy series Monty Python's Flying Circus. (See § Naming.) Python 2.0 was released on 16 October 2000, featuring many new features such as list comprehensions, cycle-detecting garbage collection, reference counting, and Unicode support. Python 2.7's end-of-life was initially set for 2015, and then postponed to 2020 out of concern that a large body of existing code could not easily be forward-ported to Python 3. It no longer receives security patches or updates. While Python 2.7 and older versions are officially unsupported, a different unofficial Python implementation, PyPy, continues to support Python 2, i.e., "2.7.18+" (plus 3.11), with the plus signifying (at least some) "backported security updates". Python 3.0 was released on 3 December 2008, and was a major revision and not completely backward-compatible with earlier versions, with some new semantics and changed syntax. Python 2.7.18, released in 2020, was the last release of Python 2. Several releases in the Python 3.x series have added new syntax to the language, and made a few (considered very minor) backward-incompatible changes. As of January 2026[update], Python 3.14.3 is the latest stable release. All older 3.x versions had a security update down to Python 3.9.24 then again with 3.9.25, the final version in 3.9 series. Python 3.10 is, since November 2025, the oldest supported branch. Python 3.15 has an alpha released, and Android has an official downloadable executable available for Python 3.14. Releases receive two years of full support followed by three years of security support. Design philosophy and features Python is a multi-paradigm programming language. Object-oriented programming and structured programming are fully supported, and many of their features support functional programming and aspect-oriented programming – including metaprogramming and metaobjects. Many other paradigms are supported via extensions, including design by contract and logic programming. Python is often referred to as a 'glue language' because it is purposely designed to be able to integrate components written in other languages. Python uses dynamic typing and a combination of reference counting and a cycle-detecting garbage collector for memory management. It uses dynamic name resolution (late binding), which binds method and variable names during program execution. Python's design offers some support for functional programming in the "Lisp tradition". It has filter, map, and reduce functions; list comprehensions, dictionaries, sets, and generator expressions. The standard library has two modules (itertools and functools) that implement functional tools borrowed from Haskell and Standard ML. Python's core philosophy is summarized in the Zen of Python (PEP 20) written by Tim Peters, which includes aphorisms such as these: However, Python has received criticism for violating these principles and adding unnecessary language bloat. Responses to these criticisms note that the Zen of Python is a guideline rather than a rule. The addition of some new features had been controversial: Guido van Rossum resigned as Benevolent Dictator for Life after conflict about adding the assignment expression operator in Python 3.8. Nevertheless, rather than building all functionality into its core, Python was designed to be highly extensible via modules. This compact modularity has made it particularly popular as a means of adding programmable interfaces to existing applications. Van Rossum's vision of a small core language with a large standard library and easily extensible interpreter stemmed from his frustrations with ABC, which represented the opposite approach. Python claims to strive for a simpler, less-cluttered syntax and grammar, while giving developers a choice in their coding methodology. Python lacks do .. while loops, which Rossum considered harmful. In contrast to Perl's motto "there is more than one way to do it", Python advocates an approach where "there should be one – and preferably only one – obvious way to do it". In practice, however, Python provides many ways to achieve a given goal. There are at least three ways to format a string literal, with no certainty as to which one a programmer should use. Alex Martelli is a Fellow at the Python Software Foundation and Python book author; he wrote that "To describe something as 'clever' is not considered a compliment in the Python culture." Python's developers typically prioritize readability over performance. For example, they reject patches to non-critical parts of the CPython reference implementation that would offer increases in speed that do not justify the cost of clarity and readability.[failed verification] Execution speed can be improved by moving speed-critical functions to extension modules written in languages such as C, or by using a just-in-time compiler like PyPy. Also, it is possible to transpile to other languages. However, this approach either fails to achieve the expected speed-up, since Python is a very dynamic language, or only a restricted subset of Python is compiled (with potential minor semantic changes). Python is meant to be a fun language to use. This goal is reflected in the name – a tribute to the British comedy group Monty Python – and in playful approaches to some tutorials and reference materials. For instance, some code examples use the terms "spam" and "eggs" (in reference to a Monty Python sketch), rather than the typical terms "foo" and "bar". A common neologism in the Python community is pythonic, which has a broad range of meanings related to program style: Pythonic code may use Python idioms well; be natural or show fluency in the language; or conform with Python's minimalist philosophy and emphasis on readability. Syntax and semantics Python is meant to be an easily readable language. Its formatting is visually uncluttered and often uses English keywords where other languages use punctuation. Unlike many other languages, it does not use curly brackets to delimit blocks, and semicolons after statements are allowed but rarely used. It has fewer syntactic exceptions and special cases than C or Pascal. Python uses whitespace indentation, rather than curly brackets or keywords, to delimit blocks. An increase in indentation comes after certain statements; a decrease in indentation signifies the end of the current block. Thus, the program's visual structure accurately represents its semantic structure. This feature is sometimes termed the off-side rule. Some other languages use indentation this way; but in most, indentation has no semantic meaning. The recommended indent size is four spaces. Python's statements include the following: The assignment statement (=) binds a name as a reference to a separate, dynamically allocated object. Variables may subsequently be rebound at any time to any object. In Python, a variable name is a generic reference holder without a fixed data type; however, it always refers to some object with a type. This is called dynamic typing—in contrast to statically-typed languages, where each variable may contain only a value of a certain type. Python does not support tail call optimization or first-class continuations; according to Van Rossum, the language never will. However, better support for coroutine-like functionality is provided by extending Python's generators. Before 2.5, generators were lazy iterators; data was passed unidirectionally out of the generator. From Python 2.5 on, it is possible to pass data back into a generator function; and from version 3.3, data can be passed through multiple stack levels. Python's expressions include the following: In Python, a distinction between expressions and statements is rigidly enforced, in contrast to languages such as Common Lisp, Scheme, or Ruby. This distinction leads to duplicating some functionality, for example: A statement cannot be part of an expression; because of this restriction, expressions such as list and dict comprehensions (and lambda expressions) cannot contain statements. As a particular case, an assignment statement such as a = 1 cannot be part of the conditional expression of a conditional statement. Python uses duck typing, and it has typed objects but untyped variable names. Type constraints are not checked at definition time; rather, operations on an object may fail at usage time, indicating that the object is not of an appropriate type. Despite being dynamically typed, Python is strongly typed, forbidding operations that are poorly defined (e.g., adding a number and a string) rather than quietly attempting to interpret them. Python allows programmers to define their own types using classes, most often for object-oriented programming. New instances of classes are constructed by calling the class, for example, SpamClass() or EggsClass()); the classes are instances of the metaclass type (which is an instance of itself), thereby allowing metaprogramming and reflection. Before version 3.0, Python had two kinds of classes, both using the same syntax: old-style and new-style. Current Python versions support the semantics of only the new style. Python supports optional type annotations. These annotations are not enforced by the language, but may be used by external tools such as mypy to catch errors. Python includes a module typing including several type names for type annotations. Also, mypy supports a Python compiler called mypyc, which leverages type annotations for optimization. 1.33333 frozenset() Python includes conventional symbols for arithmetic operators (+, -, *, /), the floor-division operator //, and the modulo operator %. (With the modulo operator, a remainder can be negative, e.g., 4 % -3 == -2.) Also, Python offers the ** symbol for exponentiation, e.g. 5**3 == 125 and 9**0.5 == 3.0. Also, it offers the matrix‑multiplication operator @ . These operators work as in traditional mathematics; with the same precedence rules, the infix operators + and - can also be unary, to represent positive and negative numbers respectively. Division between integers produces floating-point results. The behavior of division has changed significantly over time: In Python terms, the / operator represents true division (or simply division), while the // operator represents floor division. Before version 3.0, the / operator represents classic division. Rounding towards negative infinity, though a different method than in most languages, adds consistency to Python. For instance, this rounding implies that the equation (a + b)//b == a//b + 1 is always true. Also, the rounding implies that the equation b*(a//b) + a%b == a is valid for both positive and negative values of a. As expected, the result of a%b lies in the half-open interval [0, b), where b is a positive integer; however, maintaining the validity of the equation requires that the result must lie in the interval (b, 0] when b is negative. Python provides a round function for rounding a float to the nearest integer. For tie-breaking, Python 3 uses the round to even method: round(1.5) and round(2.5) both produce 2. Python versions before 3 used the round-away-from-zero method: round(0.5) is 1.0, and round(-0.5) is −1.0. Python allows Boolean expressions that contain multiple equality relations to be consistent with general usage in mathematics. For example, the expression a < b < c tests whether a is less than b and b is less than c. C-derived languages interpret this expression differently: in C, the expression would first evaluate a < b, resulting in 0 or 1, and that result would then be compared with c. Python uses arbitrary-precision arithmetic for all integer operations. The Decimal type/class in the decimal module provides decimal floating-point numbers to a pre-defined arbitrary precision with several rounding modes. The Fraction class in the fractions module provides arbitrary precision for rational numbers. Due to Python's extensive mathematics library and the third-party library NumPy, the language is frequently used for scientific scripting in tasks such as numerical data processing and manipulation. Functions are created in Python by using the def keyword. A function is defined similarly to how it is called, by first providing the function name and then the required parameters. Here is an example of a function that prints its inputs: To assign a default value to a function parameter in case no actual value is provided at run time, variable-definition syntax can be used inside the function header. Code examples "Hello, World!" program: Program to calculate the factorial of a non-negative integer: Libraries Python's large standard library is commonly cited as one of its greatest strengths. For Internet-facing applications, many standard formats and protocols such as MIME and HTTP are supported. The language includes modules for creating graphical user interfaces, connecting to relational databases, generating pseudorandom numbers, arithmetic with arbitrary-precision decimals, manipulating regular expressions, and unit testing. Some parts of the standard library are covered by specifications—for example, the Web Server Gateway Interface (WSGI) implementation wsgiref follows PEP 333—but most parts are specified by their code, internal documentation, and test suites. However, because most of the standard library is cross-platform Python code, only a few modules must be altered or rewritten for variant implementations. As of 13 March 2025,[update] the Python Package Index (PyPI), the official repository for third-party Python software, contains over 614,339 packages. Development environments Most[which?] Python implementations (including CPython) include a read–eval–print loop (REPL); this permits the environment to function as a command line interpreter, with which users enter statements sequentially and receive results immediately. Also, CPython is bundled with an integrated development environment (IDE) called IDLE, which is oriented toward beginners.[citation needed] Other shells, including IDLE and IPython, add additional capabilities such as improved auto-completion, session-state retention, and syntax highlighting. Standard desktop IDEs include PyCharm, Spyder, and Visual Studio Code; there are web browser-based IDEs, such as the following environments: Implementations CPython is the reference implementation of Python. This implementation is written in C, meeting the C11 standard since version 3.11. Older versions use the C89 standard with several select C99 features, but third-party extensions are not limited to older C versions—e.g., they can be implemented using C11 or C++. CPython compiles Python programs into an intermediate bytecode, which is then executed by a virtual machine. CPython is distributed with a large standard library written in a combination of C and native Python. CPython is available for many platforms, including Windows and most modern Unix-like systems, including macOS (and Apple M1 Macs, since Python 3.9.1, using an experimental installer). Starting with Python 3.9, the Python installer intentionally fails to install on Windows 7 and 8; Windows XP was supported until Python 3.5, with unofficial support for VMS. Platform portability was one of Python's earliest priorities. During development of Python 1 and 2, even OS/2 and Solaris were supported; since that time, support has been dropped for many platforms. All current Python versions (since 3.7) support only operating systems that feature multithreading, by now supporting not nearly as many operating systems (dropping many outdated) than in the past. All alternative implementations have at least slightly different semantics. For example, an alternative may include unordered dictionaries, in contrast to other current Python versions. As another example in the larger Python ecosystem, PyPy does not support the full C Python API. Creating an executable with Python often is done by bundling an entire Python interpreter into the executable, which causes binary sizes to be massive for small programs, yet there exist implementations that are capable of truly compiling Python. Alternative implementations include the following: Stackless Python is a significant fork of CPython that implements microthreads. This implementation uses the call stack differently, thus allowing massively concurrent programs. PyPy also offers a stackless version. Just-in-time Python compilers have been developed, but are now unsupported: There are several compilers/transpilers to high-level object languages; the source language is unrestricted Python, a subset of Python, or a language similar to Python: There are also specialized compilers: Some older projects existed, as well as compilers not designed for use with Python 3.x and related syntax: A performance comparison among various Python implementations, using a non-numerical (combinatorial) workload, was presented at EuroSciPy '13. In addition, Python's performance relative to other programming languages is benchmarked by The Computer Language Benchmarks Game. There are several approaches to optimizing Python performance, despite the inherent slowness of an interpreted language. These approaches include the following strategies or tools: Language Development Python's development is conducted mostly through the Python Enhancement Proposal (PEP) process; this process is the primary mechanism for proposing major new features, collecting community input on issues, and documenting Python design decisions. Python coding style is covered in PEP 8. Outstanding PEPs are reviewed and commented on by the Python community and the steering council. Enhancement of the language corresponds with development of the CPython reference implementation. The mailing list python-dev is the primary forum for the language's development. Specific issues were originally discussed in the Roundup bug tracker hosted by the foundation. In 2022, all issues and discussions were migrated to GitHub. Development originally took place on a self-hosted source-code repository running Mercurial, until Python moved to GitHub in January 2017. CPython's public releases have three types, distinguished by which part of the version number is incremented: Many alpha, beta, and release-candidates are also released as previews and for testing before final releases. Although there is a rough schedule for releases, they are often delayed if the code is not ready yet. Python's development team monitors the state of the code by running a large unit test suite during development. The major academic conference on Python is PyCon. Also, there are special Python mentoring programs, such as PyLadies. Naming Python's name is inspired by the British comedy group Monty Python, whom Python creator Guido van Rossum enjoyed while developing the language. Monty Python references appear frequently in Python code and culture; for example, the metasyntactic variables often used in Python literature are spam and eggs, rather than the traditional foo and bar. Also, the official Python documentation contains various references to Monty Python routines. Python users are sometimes referred to as "Pythonistas". Languages influenced by Python See also Notes References Further reading External links |
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Contents Elon Musk Elon Reeve Musk (/ˈiːlɒn/ EE-lon; born June 28, 1971) is a businessman and entrepreneur known for his leadership of Tesla, SpaceX, Twitter, and xAI. Musk has been the wealthiest person in the world since 2025; as of February 2026,[update] Forbes estimates his net worth to be around US$852 billion. Born into a wealthy family in Pretoria, South Africa, Musk emigrated in 1989 to Canada; he has Canadian citizenship since his mother was born there. He received bachelor's degrees in 1997 from the University of Pennsylvania before moving to California to pursue business ventures. In 1995, Musk co-founded the software company Zip2. Following its sale in 1999, he co-founded X.com, an online payment company that later merged to form PayPal, which was acquired by eBay in 2002. Musk also became an American citizen in 2002. In 2002, Musk founded the space technology company SpaceX, becoming its CEO and chief engineer; the company has since led innovations in reusable rockets and commercial spaceflight. Musk joined the automaker Tesla as an early investor in 2004 and became its CEO and product architect in 2008; it has since become a leader in electric vehicles. In 2015, he co-founded OpenAI to advance artificial intelligence (AI) research, but later left; growing discontent with the organization's direction and their leadership in the AI boom in the 2020s led him to establish xAI, which became a subsidiary of SpaceX in 2026. In 2022, he acquired the social network Twitter, implementing significant changes, and rebranding it as X in 2023. His other businesses include the neurotechnology company Neuralink, which he co-founded in 2016, and the tunneling company the Boring Company, which he founded in 2017. In November 2025, a Tesla pay package worth $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Musk was the largest donor in the 2024 U.S. presidential election, where he supported Donald Trump. After Trump was inaugurated as president in early 2025, Musk served as Senior Advisor to the President and as the de facto head of the Department of Government Efficiency (DOGE). After a public feud with Trump, Musk left the Trump administration and returned to managing his companies. Musk is a supporter of global far-right figures, causes, and political parties. His political activities, views, and statements have made him a polarizing figure. Musk has been criticized for COVID-19 misinformation, promoting conspiracy theories, and affirming antisemitic, racist, and transphobic comments. His acquisition of Twitter was controversial due to a subsequent increase in hate speech and the spread of misinformation on the service, following his pledge to decrease censorship. His role in the second Trump administration attracted public backlash, particularly in response to DOGE. The emails he sent to Jeffrey Epstein are included in the Epstein files, which were published between 2025–26 and became a topic of worldwide debate. Early life Elon Reeve Musk was born on June 28, 1971, in Pretoria, South Africa's administrative capital. He is of British and Pennsylvania Dutch ancestry. His mother, Maye (née Haldeman), is a model and dietitian born in Saskatchewan, Canada, and raised in South Africa. Musk therefore holds both South African and Canadian citizenship from birth. His father, Errol Musk, is a South African electromechanical engineer, pilot, sailor, consultant, emerald dealer, and property developer, who partly owned a rental lodge at Timbavati Private Nature Reserve. His maternal grandfather, Joshua N. Haldeman, who died in a plane crash when Elon was a toddler, was an American-born Canadian chiropractor, aviator and political activist in the technocracy movement who moved to South Africa in 1950. Elon has a younger brother, Kimbal, a younger sister, Tosca, and four paternal half-siblings. Musk was baptized as a child in the Anglican Church of Southern Africa. Despite both Elon and Errol previously stating that Errol was a part owner of a Zambian emerald mine, in 2023, Errol recounted that the deal he made was to receive "a portion of the emeralds produced at three small mines". Errol was elected to the Pretoria City Council as a representative of the anti-apartheid Progressive Party and has said that his children shared their father's dislike of apartheid. After his parents divorced in 1979, Elon, aged around 9, chose to live with his father because Errol Musk had an Encyclopædia Britannica and a computer. Elon later regretted his decision and became estranged from his father. Elon has recounted trips to a wilderness school that he described as a "paramilitary Lord of the Flies" where "bullying was a virtue" and children were encouraged to fight over rations. In one incident, after an altercation with a fellow pupil, Elon was thrown down concrete steps and beaten severely, leading to him being hospitalized for his injuries. Elon described his father berating him after he was discharged from the hospital. Errol denied berating Elon and claimed, "The [other] boy had just lost his father to suicide, and Elon had called him stupid. Elon had a tendency to call people stupid. How could I possibly blame that child?" Elon was an enthusiastic reader of books, and had attributed his success in part to having read The Lord of the Rings, the Foundation series, and The Hitchhiker's Guide to the Galaxy. At age ten, he developed an interest in computing and video games, teaching himself how to program from the VIC-20 user manual. At age twelve, Elon sold his BASIC-based game Blastar to PC and Office Technology magazine for approximately $500 (equivalent to $1,600 in 2025). Musk attended Waterkloof House Preparatory School, Bryanston High School, and then Pretoria Boys High School, where he graduated. Musk was a decent but unexceptional student, earning a 61/100 in Afrikaans and a B on his senior math certification. Musk applied for a Canadian passport through his Canadian-born mother to avoid South Africa's mandatory military service, which would have forced him to participate in the apartheid regime, as well as to ease his path to immigration to the United States. While waiting for his application to be processed, he attended the University of Pretoria for five months. Musk arrived in Canada in June 1989, connected with a second cousin in Saskatchewan, and worked odd jobs, including at a farm and a lumber mill. In 1990, he entered Queen's University in Kingston, Ontario. Two years later, he transferred to the University of Pennsylvania, where he studied until 1995. Although Musk has said that he earned his degrees in 1995, the University of Pennsylvania did not award them until 1997 – a Bachelor of Arts in physics and a Bachelor of Science in economics from the university's Wharton School. He reportedly hosted large, ticketed house parties to help pay for tuition, and wrote a business plan for an electronic book-scanning service similar to Google Books. In 1994, Musk held two internships in Silicon Valley: one at energy storage startup Pinnacle Research Institute, which investigated electrolytic supercapacitors for energy storage, and another at Palo Alto–based startup Rocket Science Games. In 1995, he was accepted to a graduate program in materials science at Stanford University, but did not enroll. Musk decided to join the Internet boom of the 1990s, applying for a job at Netscape, to which he reportedly never received a response. The Washington Post reported that Musk lacked legal authorization to remain and work in the United States after failing to enroll at Stanford. In response, Musk said he was allowed to work at that time and that his student visa transitioned to an H1-B. According to numerous former business associates and shareholders, Musk said he was on a student visa at the time. Business career In 1995, Musk, his brother Kimbal, and Greg Kouri founded the web software company Zip2 with funding from a group of angel investors. They housed the venture at a small rented office in Palo Alto. Replying to Rolling Stone, Musk denounced the notion that they started their company with funds borrowed from Errol Musk, but in a tweet, he recognized that his father contributed 10% of a later funding round. The company developed and marketed an Internet city guide for the newspaper publishing industry, with maps, directions, and yellow pages. According to Musk, "The website was up during the day and I was coding it at night, seven days a week, all the time." To impress investors, Musk built a large plastic structure around a standard computer to create the impression that Zip2 was powered by a small supercomputer. The Musk brothers obtained contracts with The New York Times and the Chicago Tribune, and persuaded the board of directors to abandon plans for a merger with CitySearch. Musk's attempts to become CEO were thwarted by the board. Compaq acquired Zip2 for $307 million in cash in February 1999 (equivalent to $590,000,000 in 2025), and Musk received $22 million (equivalent to $43,000,000 in 2025) for his 7-percent share. In 1999, Musk co-founded X.com, an online financial services and e-mail payment company. The startup was one of the first federally insured online banks, and, in its initial months of operation, over 200,000 customers joined the service. The company's investors regarded Musk as inexperienced and replaced him with Intuit CEO Bill Harris by the end of the year. The following year, X.com merged with online bank Confinity to avoid competition. Founded by Max Levchin and Peter Thiel, Confinity had its own money-transfer service, PayPal, which was more popular than X.com's service. Within the merged company, Musk returned as CEO. Musk's preference for Microsoft software over Unix created a rift in the company and caused Thiel to resign. Due to resulting technological issues and lack of a cohesive business model, the board ousted Musk and replaced him with Thiel in 2000.[b] Under Thiel, the company focused on the PayPal service and was renamed PayPal in 2001. In 2002, PayPal was acquired by eBay for $1.5 billion (equivalent to $2,700,000,000 in 2025) in stock, of which Musk—the largest shareholder with 11.72% of shares—received $175.8 million (equivalent to $320,000,000 in 2025). In 2017, Musk purchased the domain X.com from PayPal for an undisclosed amount, stating that it had sentimental value. In 2001, Musk became involved with the nonprofit Mars Society and discussed funding plans to place a growth-chamber for plants on Mars. Seeking a way to launch the greenhouse payloads into space, Musk made two unsuccessful trips to Moscow to purchase intercontinental ballistic missiles (ICBMs) from Russian companies NPO Lavochkin and Kosmotras. Musk instead decided to start a company to build affordable rockets. With $100 million of his early fortune, (equivalent to $180,000,000 in 2025) Musk founded SpaceX in May 2002 and became the company's CEO and Chief Engineer. SpaceX attempted its first launch of the Falcon 1 rocket in 2006. Although the rocket failed to reach Earth orbit, it was awarded a Commercial Orbital Transportation Services program contract from NASA, then led by Mike Griffin. After two more failed attempts that nearly caused Musk to go bankrupt, SpaceX succeeded in launching the Falcon 1 into orbit in 2008. Later that year, SpaceX received a $1.6 billion NASA contract (equivalent to $2,400,000,000 in 2025) for Falcon 9-launched Dragon spacecraft flights to the International Space Station (ISS), replacing the Space Shuttle after its 2011 retirement. In 2012, the Dragon vehicle docked with the ISS, a first for a commercial spacecraft. Working towards its goal of reusable rockets, in 2015 SpaceX successfully landed the first stage of a Falcon 9 on a land platform. Later landings were achieved on autonomous spaceport drone ships, an ocean-based recovery platform. In 2018, SpaceX launched the Falcon Heavy; the inaugural mission carried Musk's personal Tesla Roadster as a dummy payload. Since 2019, SpaceX has been developing Starship, a reusable, super heavy-lift launch vehicle intended to replace the Falcon 9 and Falcon Heavy. In 2020, SpaceX launched its first crewed flight, the Demo-2, becoming the first private company to place astronauts into orbit and dock a crewed spacecraft with the ISS. In 2024, NASA awarded SpaceX an $843 million (equivalent to $865,000,000 in 2025) contract to build a spacecraft that NASA will use to deorbit the ISS at the end of its lifespan. In 2015, SpaceX began development of the Starlink constellation of low Earth orbit satellites to provide satellite Internet access. After the launch of prototype satellites in 2018, the first large constellation was deployed in May 2019. As of May 2025[update], over 7,600 Starlink satellites are operational, comprising 65% of all operational Earth satellites. The total cost of the decade-long project to design, build, and deploy the constellation was estimated by SpaceX in 2020 to be $10 billion (equivalent to $12,000,000,000 in 2025).[c] During the Russian invasion of Ukraine, Musk provided free Starlink service to Ukraine, permitting Internet access and communication at a yearly cost to SpaceX of $400 million (equivalent to $440,000,000 in 2025). However, Musk refused to block Russian state media on Starlink. In 2023, Musk denied Ukraine's request to activate Starlink over Crimea to aid an attack against the Russian navy, citing fears of a nuclear response. Tesla, Inc., originally Tesla Motors, was incorporated in July 2003 by Martin Eberhard and Marc Tarpenning. Both men played active roles in the company's early development prior to Musk's involvement. Musk led the Series A round of investment in February 2004; he invested $6.35 million (equivalent to $11,000,000 in 2025), became the majority shareholder, and joined Tesla's board of directors as chairman. Musk took an active role within the company and oversaw Roadster product design, but was not deeply involved in day-to-day business operations. Following a series of escalating conflicts in 2007 and the 2008 financial crisis, Eberhard was ousted from the firm.[page needed] Musk assumed leadership of the company as CEO and product architect in 2008. A 2009 lawsuit settlement with Eberhard designated Musk as a Tesla co-founder, along with Tarpenning and two others. Tesla began delivery of the Roadster, an electric sports car, in 2008. With sales of about 2,500 vehicles, it was the first mass production all-electric car to use lithium-ion battery cells. Under Musk, Tesla has since launched several well-selling electric vehicles, including the four-door sedan Model S (2012), the crossover Model X (2015), the mass-market sedan Model 3 (2017), the crossover Model Y (2020), and the pickup truck Cybertruck (2023). In May 2020, Musk resigned as chairman of the board as part of the settlement of a lawsuit from the SEC over him tweeting that funding had been "secured" for potentially taking Tesla private. The company has also constructed multiple lithium-ion battery and electric vehicle factories, called Gigafactories. Since its initial public offering in 2010, Tesla stock has risen significantly; it became the most valuable carmaker in summer 2020, and it entered the S&P 500 later that year. In October 2021, it reached a market capitalization of $1 trillion (equivalent to $1,200,000,000,000 in 2025), the sixth company in U.S. history to do so. Musk provided the initial concept and financial capital for SolarCity, which his cousins Lyndon and Peter Rive founded in 2006. By 2013, SolarCity was the second largest provider of solar power systems in the United States. In 2014, Musk promoted the idea of SolarCity building an advanced production facility in Buffalo, New York, triple the size of the largest solar plant in the United States. Construction of the factory started in 2014 and was completed in 2017. It operated as a joint venture with Panasonic until early 2020. Tesla acquired SolarCity for $2 billion in 2016 (equivalent to $2,700,000,000 in 2025) and merged it with its battery unit to create Tesla Energy. The deal's announcement resulted in a more than 10% drop in Tesla's stock price; at the time, SolarCity was facing liquidity issues. Multiple shareholder groups filed a lawsuit against Musk and Tesla's directors, stating that the purchase of SolarCity was done solely to benefit Musk and came at the expense of Tesla and its shareholders. Tesla directors settled the lawsuit in January 2020, leaving Musk the sole remaining defendant. Two years later, the court ruled in Musk's favor. In 2016, Musk co-founded Neuralink, a neurotechnology startup, with an investment of $100 million. Neuralink aims to integrate the human brain with artificial intelligence (AI) by creating devices that are embedded in the brain. Such technology could enhance memory or allow the devices to communicate with software. The company also hopes to develop devices to treat neurological conditions like spinal cord injuries. In 2022, Neuralink announced that clinical trials would begin by the end of the year. In September 2023, the Food and Drug Administration approved Neuralink to initiate six-year human trials. Neuralink has conducted animal testing on macaques at the University of California, Davis. In 2021, the company released a video in which a macaque played the video game Pong via a Neuralink implant. The company's animal trials—which have caused the deaths of some monkeys—have led to claims of animal cruelty. The Physicians Committee for Responsible Medicine has alleged that Neuralink violated the Animal Welfare Act. Employees have complained that pressure from Musk to accelerate development has led to botched experiments and unnecessary animal deaths. In 2022, a federal probe was launched into possible animal welfare violations by Neuralink.[needs update] In 2017, Musk founded the Boring Company to construct tunnels; he also revealed plans for specialized, underground, high-occupancy vehicles that could travel up to 150 miles per hour (240 km/h) and thus circumvent above-ground traffic in major cities. Early in 2017, the company began discussions with regulatory bodies and initiated construction of a 30-foot (9.1 m) wide, 50-foot (15 m) long, and 15-foot (4.6 m) deep "test trench" on the premises of SpaceX's offices, as that required no permits. The Los Angeles tunnel, less than two miles (3.2 km) in length, debuted to journalists in 2018. It used Tesla Model Xs and was reported to be a rough ride while traveling at suboptimal speeds. Two tunnel projects announced in 2018, in Chicago and West Los Angeles, have been canceled. A tunnel beneath the Las Vegas Convention Center was completed in early 2021. Local officials have approved further expansions of the tunnel system. April 14, 2022 In early 2017, Musk expressed interest in buying Twitter and had questioned the platform's commitment to freedom of speech. By 2022, Musk had reached 9.2% stake in the company, making him the largest shareholder.[d] Musk later agreed to a deal that would appoint him to Twitter's board of directors and prohibit him from acquiring more than 14.9% of the company. Days later, Musk made a $43 billion offer to buy Twitter. By the end of April Musk had successfully concluded his bid for approximately $44 billion. This included approximately $12.5 billion in loans and $21 billion in equity financing. Having backtracked on his initial decision, Musk bought the company on October 27, 2022. Immediately after the acquisition, Musk fired several top Twitter executives including CEO Parag Agrawal; Musk became the CEO instead. Under Elon Musk, Twitter instituted monthly subscriptions for a "blue check", and laid off a significant portion of the company's staff. Musk lessened content moderation and hate speech also increased on the platform after his takeover. In late 2022, Musk released internal documents relating to Twitter's moderation of Hunter Biden's laptop controversy in the lead-up to the 2020 presidential election. Musk also promised to step down as CEO after a Twitter poll, and five months later, Musk stepped down as CEO and transitioned his role to executive chairman and chief technology officer (CTO). Despite Musk stepping down as CEO, X continues to struggle with challenges such as viral misinformation, hate speech, and antisemitism controversies. Musk has been accused of trying to silence some of his critics such as Twitch streamer Asmongold, who criticized him during one of his streams. Musk has been accused of removing their accounts' blue checkmarks, which hinders visibility and is considered a form of shadow banning, or suspending their accounts without justification. Other activities In August 2013, Musk announced plans for a version of a vactrain, and assigned engineers from SpaceX and Tesla to design a transport system between Greater Los Angeles and the San Francisco Bay Area, at an estimated cost of $6 billion. Later that year, Musk unveiled the concept, dubbed the Hyperloop, intended to make travel cheaper than any other mode of transport for such long distances. In December 2015, Musk co-founded OpenAI, a not-for-profit artificial intelligence (AI) research company aiming to develop artificial general intelligence, intended to be safe and beneficial to humanity. Musk pledged $1 billion of funding to the company, and initially gave $50 million. In 2018, Musk left the OpenAI board. Since 2018, OpenAI has made significant advances in machine learning. In July 2023, Musk launched the artificial intelligence company xAI, which aims to develop a generative AI program that competes with existing offerings like OpenAI's ChatGPT. Musk obtained funding from investors in SpaceX and Tesla, and xAI hired engineers from Google and OpenAI. December 16, 2022 Musk uses a private jet owned by Falcon Landing LLC, a SpaceX-linked company, and acquired a second jet in August 2020. His heavy use of the jets and the consequent fossil fuel usage have received criticism. Musk's flight usage is tracked on social media through ElonJet. In December 2022, Musk banned the ElonJet account on Twitter, and made temporary bans on the accounts of journalists that posted stories regarding the incident, including Donie O'Sullivan, Keith Olbermann, and journalists from The New York Times, The Washington Post, CNN, and The Intercept. In October 2025, Musk's company xAI launched Grokipedia, an AI-generated online encyclopedia that he promoted as an alternative to Wikipedia. Articles on Grokipedia are generated and reviewed by xAI's Grok chatbot. Media coverage and academic analysis described Grokipedia as frequently reusing Wikipedia content but framing contested political and social topics in line with Musk's own views and right-wing narratives. A study by Cornell University researchers and NBC News stated that Grokipedia cites sources that are blacklisted or considered "generally unreliable" on Wikipedia, for example, the conspiracy site Infowars and the neo-Nazi forum Stormfront. Wired, The Guardian and Time criticized Grokipedia for factual errors and for presenting Musk himself in unusually positive terms while downplaying controversies. Politics Musk is an outlier among business leaders who typically avoid partisan political advocacy. Musk was a registered independent voter when he lived in California. Historically, he has donated to both Democrats and Republicans, many of whom serve in states in which he has a vested interest. Since 2022, his political contributions have mostly supported Republicans, with his first vote for a Republican going to Mayra Flores in the 2022 Texas's 34th congressional district special election. In 2024, he started supporting international far-right political parties, activists, and causes, and has shared misinformation and numerous conspiracy theories. Since 2024, his views have been generally described as right-wing. Musk supported Barack Obama in 2008 and 2012, Hillary Clinton in 2016, Joe Biden in 2020, and Donald Trump in 2024. In the 2020 Democratic Party presidential primaries, Musk endorsed candidate Andrew Yang and expressed support for Yang's proposed universal basic income, and endorsed Kanye West's 2020 presidential campaign. In 2021, Musk publicly expressed opposition to the Build Back Better Act, a $3.5 trillion legislative package endorsed by Joe Biden that ultimately failed to pass due to unanimous opposition from congressional Republicans and several Democrats. In 2022, gave over $50 million to Citizens for Sanity, a conservative political action committee. In 2023, he supported Republican Ron DeSantis for the 2024 U.S. presidential election, giving $10 million to his campaign, and hosted DeSantis's campaign announcement on a Twitter Spaces event. From June 2023 to January 2024, Musk hosted a bipartisan set of X Spaces with Republican and Democratic candidates, including Robert F. Kennedy Jr., Vivek Ramaswamy, and Dean Phillips. In October 2025, former vice-president Kamala Harris commented that it was a mistake from the Democratic side to not invite Musk to a White House electric vehicle event organized in August 2021 and featuring executives from General Motors, Ford and Stellantis, despite Tesla being "the major American manufacturer of extraordinary innovation in this space." Fortune remarked that this was a nod to United Auto Workers and organized labor. Harris said presidents should put aside political loyalties when it came to recognizing innovation, and guessed that the non-invitation impacted Musk's perspective. Fortune noted that, at the time, Musk said, "Yeah, seems odd that Tesla wasn't invited." A month later, he criticized Biden as "not the friendliest administration." Jacob Silverman, author of the book Gilded Rage: Elon Musk and the Radicalization of Silicon Valley, said that the tech industry represented by Musk, Thiel, Andreessen and other capitalists, actually flourished under Biden, but the tech leaders chose Trump for their common ground on cultural issues. By early 2024, Musk had become a vocal and financial supporter of Donald Trump. In July 2024, minutes after the attempted assassination of Donald Trump, Musk endorsed him for president saying; "I fully endorse President Trump and hope for his rapid recovery." During the presidential campaign, Musk joined Trump on stage at a campaign rally, and during the campaign promoted conspiracy theories and falsehoods about Democrats, election fraud and immigration, in support of Trump. Musk was the largest individual donor of the 2024 election. In 2025, Musk contributed $19 million to the Wisconsin Supreme Court race, hoping to influence the state's future redistricting efforts and its regulations governing car manufacturers and dealers. In 2023, Musk said he shunned the World Economic Forum because it was boring. The organization commented that they had not invited him since 2015. He has participated in Dialog, dubbed "Tech Bilderberg" and organized by Peter Thiel and Auren Hoffman, though. Musk's international political actions and comments have come under increasing scrutiny and criticism, especially from the governments and leaders of France, Germany, Norway, Spain and the United Kingdom, particularly due to his position in the U.S. government as well as ownership of X. An NBC News analysis found he had boosted far-right political movements to cut immigration and curtail regulation of business in at least 18 countries on six continents since 2023. During his speech after the second inauguration of Donald Trump, Musk twice made a gesture interpreted by many as a Nazi or a fascist Roman salute.[e] He thumped his right hand over his heart, fingers spread wide, and then extended his right arm out, emphatically, at an upward angle, palm down and fingers together. He then repeated the gesture to the crowd behind him. As he finished the gestures, he said to the crowd, "My heart goes out to you. It is thanks to you that the future of civilization is assured." It was widely condemned as an intentional Nazi salute in Germany, where making such gestures is illegal. The Anti-Defamation League said it was not a Nazi salute, but other Jewish organizations disagreed and condemned the salute. American public opinion was divided on partisan lines as to whether it was a fascist salute. Musk dismissed the accusations of Nazi sympathies, deriding them as "dirty tricks" and a "tired" attack. Neo-Nazi and white supremacist groups celebrated it as a Nazi salute. Multiple European political parties demanded that Musk be banned from entering their countries. The concept of DOGE emerged in a discussion between Musk and Donald Trump, and in August 2024, Trump committed to giving Musk an advisory role, with Musk accepting the offer. In November and December 2024, Musk suggested that the organization could help to cut the U.S. federal budget, consolidate the number of federal agencies, and eliminate the Consumer Financial Protection Bureau, and that its final stage would be "deleting itself". In January 2025, the organization was created by executive order, and Musk was designated a "special government employee". Musk led the organization and was a senior advisor to the president, although his official role is not clear. In sworn statement during a lawsuit, the director of the White House Office of Administration stated that Musk "is not an employee of the U.S. DOGE Service or U.S. DOGE Service Temporary Organization", "is not the U.S. DOGE Service administrator", and has "no actual or formal authority to make government decisions himself". Trump said two days later that he had put Musk in charge of DOGE. A federal judge has ruled that Musk acted as the de facto leader of DOGE. Musk's role in the second Trump administration, particularly in response to DOGE, has attracted public backlash. He was criticized for his treatment of federal government employees, including his influence over the mass layoffs of the federal workforce. He has prioritized secrecy within the organization and has accused others of violating privacy laws. A Senate report alleged that Musk could avoid up to $2 billion in legal liability as a result of DOGE's actions. In May 2025, Bill Gates accused Musk of "killing the world's poorest children" through his cuts to USAID, which modeling by Boston University estimated had resulted in 300,000 deaths by this time, most of them of children. By November 2025, the estimated death toll had increased to 400,000 children and 200,000 adults. Musk announced on May 28, 2025, that he would depart from the Trump administration as planned when the special government employee's 130 day deadline expired, with a White House official confirming that Musk's offboarding from the Trump administration was already underway. His departure was officially confirmed during a joint Oval Office press conference with Trump on May 30, 2025. @realDonaldTrump is in the Epstein files. That is the real reason they have not been made public. June 5, 2025 After leaving office, Musk criticized the Trump administration's Big Beautiful Bill, calling it a "disgusting abomination" due to its provisions increasing the deficit. A feud began between Musk and Trump, with its most notable event being Musk alleging Trump had ties to sex offender Jeffrey Epstein on X (formerly Twitter) on June 5, 2025. Trump responded on Truth Social stating that Musk went "CRAZY" after the "EV Mandate" was purportedly taken away and threatened to cut Musk's government contracts. Musk then called for a third Trump impeachment. The next day, Trump stated that he did not wish to reconcile with Musk, and added that Musk would face "very serious consequences" if he funds Democratic candidates. On June 11, Musk publicly apologized for the tweets against Trump, saying they "went too far". Views November 6, 2022 Rejecting the conservative label, Musk has described himself as a political moderate, even as his views have become more right-wing over time. His views have been characterized as libertarian and far-right, and after his involvement in European politics, they have received criticism from world leaders such as Emmanuel Macron and Olaf Scholz. Within the context of American politics, Musk supported Democratic candidates up until 2022, at which point he voted for a Republican for the first time. He has stated support for universal basic income, gun rights, freedom of speech, a tax on carbon emissions, and H-1B visas. Musk has expressed concern about issues such as artificial intelligence (AI) and climate change, and has been a critic of wealth tax, short-selling, and government subsidies. An immigrant himself, Musk has been accused of being anti-immigration, and regularly blames immigration policies for illegal immigration. He is also a pronatalist who believes population decline is the biggest threat to civilization, and identifies as a cultural Christian. Musk has long been an advocate for space colonization, especially the colonization of Mars. He has repeatedly pushed for humanity colonizing Mars, in order to become an interplanetary species and lower the risks of human extinction. Musk has promoted conspiracy theories and made controversial statements that have led to accusations of racism, sexism, antisemitism, transphobia, disseminating disinformation, and support of white pride. While describing himself as a "pro-Semite", his comments regarding George Soros and Jewish communities have been condemned by the Anti-Defamation League and the Biden White House. Musk was criticized during the COVID-19 pandemic for making unfounded epidemiological claims, defying COVID-19 lockdowns restrictions, and supporting the Canada convoy protest against vaccine mandates. He has amplified false claims of white genocide in South Africa. Musk has been critical of Israel's actions in the Gaza Strip during the Gaza war, praised China's economic and climate goals, suggested that Taiwan and China should resolve cross-strait relations, and was described as having a close relationship with the Chinese government. In Europe, Musk expressed support for Ukraine in 2022 during the Russian invasion, recommended referendums and peace deals on the annexed Russia-occupied territories, and supported the far-right Alternative for Germany political party in 2024. Regarding British politics, Musk blamed the 2024 UK riots on mass migration and open borders, criticized Prime Minister Keir Starmer for what he described as a "two-tier" policing system, and was subsequently attacked as being responsible for spreading misinformation and amplifying the far-right. He has also voiced his support for far-right activist Tommy Robinson and pledged electoral support for Reform UK. In February 2026, Musk described Spanish Prime Minister Pedro Sánchez as a "tyrant" following Sánchez's proposal to prohibit minors under the age of 16 from accessing social media platforms. Legal affairs In 2018, Musk was sued by the U.S. Securities and Exchange Commission (SEC) for a tweet stating that funding had been secured for potentially taking Tesla private.[f] The securities fraud lawsuit characterized the tweet as false, misleading, and damaging to investors, and sought to bar Musk from serving as CEO of publicly traded companies. Two days later, Musk settled with the SEC, without admitting or denying the SEC's allegations. As a result, Musk and Tesla were fined $20 million each, and Musk was forced to step down for three years as Tesla chairman but was able to remain as CEO. Shareholders filed a lawsuit over the tweet, and in February 2023, a jury found Musk and Tesla not liable. Musk has stated in interviews that he does not regret posting the tweet that triggered the SEC investigation. In 2019, Musk stated in a tweet that Tesla would build half a million cars that year. The SEC reacted by asking a court to hold him in contempt for violating the terms of the 2018 settlement agreement. A joint agreement between Musk and the SEC eventually clarified the previous agreement details, including a list of topics about which Musk needed preclearance. In 2020, a judge blocked a lawsuit that claimed a tweet by Musk regarding Tesla stock price ("too high imo") violated the agreement. Freedom of Information Act (FOIA)-released records showed that the SEC concluded Musk had subsequently violated the agreement twice by tweeting regarding "Tesla's solar roof production volumes and its stock price". In October 2023, the SEC sued Musk over his refusal to testify a third time in an investigation into whether he violated federal law by purchasing Twitter stock in 2022. In February 2024, Judge Laurel Beeler ruled that Musk must testify again. In January 2025, the SEC filed a lawsuit against Musk for securities violations related to his purchase of Twitter. In January 2024, Delaware judge Kathaleen McCormick ruled in a 2018 lawsuit that Musk's $55 billion pay package from Tesla be rescinded. McCormick called the compensation granted by the company's board "an unfathomable sum" that was unfair to shareholders. The Delaware Supreme Court overturned McCormick's decision in December 2025, restoring Musk's compensation package and awarding $1 in nominal damages. Personal life Musk became a U.S. citizen in 2002. From the early 2000s until late 2020, Musk resided in California, where both Tesla and SpaceX were founded. He then relocated to Cameron County, Texas, saying that California had become "complacent" about its economic success. While hosting Saturday Night Live in 2021, Musk stated that he has Asperger syndrome (an outdated term for autism spectrum disorder). When asked about his experience growing up with Asperger's syndrome in a TED2022 conference in Vancouver, Musk stated that "the social cues were not intuitive ... I would just tend to take things very literally ... but then that turned out to be wrong — [people were not] simply saying exactly what they mean, there's all sorts of other things that are meant, and [it] took me a while to figure that out." Musk suffers from back pain and has undergone several spine-related surgeries, including a disc replacement. In 2000, he contracted a severe case of malaria while on vacation in South Africa. Musk has stated he uses doctor-prescribed ketamine for occasional depression and that he doses "a small amount once every other week or something like that"; since January 2024, some media outlets have reported that he takes ketamine, marijuana, LSD, ecstasy, mushrooms, cocaine and other drugs. Musk at first refused to comment on his alleged drug use, before responding that he had not tested positive for drugs, and that if drugs somehow improved his productivity, "I would definitely take them!". The New York Times' investigations revealed Musk's overuse of ketamine and numerous other drugs, as well as strained family relationships and concerns from close associates who have become troubled by his public behavior as he became more involved in political activities and government work. According to The Washington Post, President Trump described Musk as "a big-time drug addict". Through his own label Emo G Records, Musk released a rap track, "RIP Harambe", on SoundCloud in March 2019. The following year, he released an EDM track, "Don't Doubt Ur Vibe", featuring his own lyrics and vocals. Musk plays video games, which he stated has a "'restoring effect' that helps his 'mental calibration'". Some games he plays include Quake, Diablo IV, Elden Ring, and Polytopia. Musk once claimed to be one of the world's top video game players but has since admitted to "account boosting", or cheating by hiring outside services to achieve top player rankings. Musk has justified the boosting by claiming that all top accounts do it so he has to as well to remain competitive. In 2024 and 2025, Musk criticized the video game Assassin's Creed Shadows and its creator Ubisoft for "woke" content. Musk posted to X that "DEI kills art" and specified the inclusion of the historical figure Yasuke in the Assassin's Creed game as offensive; he also called the game "terrible". Ubisoft responded by saying that Musk's comments were "just feeding hatred" and that they were focused on producing a game not pushing politics. Musk has fathered at least 14 children, one of whom died as an infant. The Wall Street Journal reported in 2025 that sources close to Musk suggest that the "true number of Musk's children is much higher than publicly known". He had six children with his first wife, Canadian author Justine Wilson, whom he met while attending Queen's University in Ontario, Canada; they married in 2000. In 2002, their first child Nevada Musk died of sudden infant death syndrome at the age of 10 weeks. After his death, the couple used in vitro fertilization (IVF) to continue their family; they had twins in 2004, followed by triplets in 2006. The couple divorced in 2008 and have shared custody of their children. The elder twin he had with Wilson came out as a trans woman and, in 2022, officially changed her name to Vivian Jenna Wilson, adopting her mother's surname because she no longer wished to be associated with Musk. Musk began dating English actress Talulah Riley in 2008. They married two years later at Dornoch Cathedral in Scotland. In 2012, the couple divorced, then remarried the following year. After briefly filing for divorce in 2014, Musk finalized a second divorce from Riley in 2016. Musk then dated the American actress Amber Heard for several months in 2017; he had reportedly been "pursuing" her since 2012. In 2018, Musk and Canadian musician Grimes confirmed they were dating. Grimes and Musk have three children, born in 2020, 2021, and 2022.[g] Musk and Grimes originally gave their eldest child the name "X Æ A-12", which would have violated California regulations as it contained characters that are not in the modern English alphabet; the names registered on the birth certificate are "X" as a first name, "Æ A-Xii" as a middle name, and "Musk" as a last name. They received criticism for choosing a name perceived to be impractical and difficult to pronounce; Musk has said the intended pronunciation is "X Ash A Twelve". Their second child was born via surrogacy. Despite the pregnancy, Musk confirmed reports that the couple were "semi-separated" in September 2021; in an interview with Time in December 2021, he said he was single. In October 2023, Grimes sued Musk over parental rights and custody of X Æ A-Xii. Elon Musk has taken X Æ A-Xii to multiple official events in Washington, D.C. during Trump's second term in office. Also in July 2022, The Wall Street Journal reported that Musk allegedly had an affair with Nicole Shanahan, the wife of Google co-founder Sergey Brin, in 2021, leading to their divorce the following year. Musk denied the report. Musk also had a relationship with Australian actress Natasha Bassett, who has been described as "an occasional girlfriend". In October 2024, The New York Times reported Musk bought a Texas compound for his children and their mothers, though Musk denied having done so. Musk also has four children with Shivon Zilis, director of operations and special projects at Neuralink: twins born via IVF in 2021, a child born in 2024 via surrogacy and a child born in 2025.[h] On February 14, 2025, Ashley St. Clair, an influencer and author, posted on X claiming to have given birth to Musk's son Romulus five months earlier, which media outlets reported as Musk's supposed thirteenth child.[i] On February 22, 2025, it was reported that St Clair had filed for sole custody of her five-month-old son and for Musk to be recognised as the child's father. On March 31, 2025, Musk wrote that, while he was unsure if he was the father of St. Clair's child, he had paid St. Clair $2.5 million and would continue paying her $500,000 per year.[j] Later reporting from the Wall Street Journal indicated that $1 million of these payments to St. Clair were structured as a loan. In 2014, Musk and Ghislaine Maxwell appeared together in a photograph taken at an Academy Awards after-party, which Musk later described as a "photobomb". The January 2026 Epstein files contain emails between Musk and Epstein from 2012 to 2013, after Epstein's first conviction. Emails released on January 30, 2026, indicated that Epstein invited Musk to visit his private island on multiple occasions. The correspondence showed that while Epstein repeatedly encouraged Musk to attend, Musk did not visit the island. In one instance, Musk discussed the possibility of attending a party with his then-wife Talulah Riley and asked which day would be the "wildest party"; according to the emails, the visit did not take place after Epstein later cancelled the plans.[k] On Christmas day in 2012, Musk emailed Epstein asking "Do you have any parties planned? I’ve been working to the edge of sanity this year and so, once my kids head home after Christmas, I really want to hit the party scene in St Barts or elsewhere and let loose. The invitation is much appreciated, but a peaceful island experience is the opposite of what I’m looking for". Epstein replied that the "ratio on my island" might make Musk's wife uncomfortable to which Musk responded, "Ratio is not a problem for Talulah". On September 11, 2013, Epstein sent an email asking Musk if he had any plans for coming to New York for the opening of the United Nations General Assembly where many "interesting people" would be coming to his house to which Musk responded that "Flying to NY to see UN diplomats do nothing would be an unwise use of time". Epstein responded by stating "Do you think i am retarded. Just kidding, there is no one over 25 and all very cute." Musk has denied any close relationship with Epstein and described him as a "creep" who attempted to ingratiate himself with influential people. When Musk was asked in 2019 if he introduced Epstein to Mark Zuckerberg, Musk responded: "I don’t recall introducing Epstein to anyone, as I don’t know the guy well enough to do so." The released emails nonetheless showed cordial exchanges on a range of topics, including Musk's inquiry about parties on the island. The correspondence also indicated that Musk suggested hosting Epstein at SpaceX, while Epstein separately discussed plans to tour SpaceX and bring "the girls", though there is no evidence that such a visit occurred. Musk has described the release of the files a "distraction", later accusing the second Trump administration of suppressing them to protect powerful individuals, including Trump himself.[l] Wealth Elon Musk is the wealthiest person in the world, with an estimated net worth of US$690 billion as of January 2026, according to the Bloomberg Billionaires Index, and $852 billion according to Forbes, primarily from his ownership stakes in SpaceX and Tesla. Having been first listed on the Forbes Billionaires List in 2012, around 75% of Musk's wealth was derived from Tesla stock in November 2020, although he describes himself as "cash poor". According to Forbes, he became the first person in the world to achieve a net worth of $300 billion in 2021; $400 billion in December 2024; $500 billion in October 2025; $600 billion in mid-December 2025; $700 billion later that month; and $800 billion in February 2026. In November 2025, a Tesla pay package worth potentially $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Public image Although his ventures have been highly influential within their separate industries starting in the 2000s, Musk only became a public figure in the early 2010s. He has been described as an eccentric who makes spontaneous and impactful decisions, while also often making controversial statements, contrary to other billionaires who prefer reclusiveness to protect their businesses. Musk's actions and his expressed views have made him a polarizing figure. Biographer Ashlee Vance described people's opinions of Musk as polarized due to his "part philosopher, part troll" persona on Twitter. He has drawn denouncement for using his platform to mock the self-selection of personal pronouns, while also receiving praise for bringing international attention to matters like British survivors of grooming gangs. Musk has been described as an American oligarch due to his extensive influence over public discourse, social media, industry, politics, and government policy. After Trump's re-election, Musk's influence and actions during the transition period and the second presidency of Donald Trump led some to call him "President Musk", the "actual president-elect", "shadow president" or "co-president". Awards for his contributions to the development of the Falcon rockets include the American Institute of Aeronautics and Astronautics George Low Transportation Award in 2008, the Fédération Aéronautique Internationale Gold Space Medal in 2010, and the Royal Aeronautical Society Gold Medal in 2012. In 2015, he received an honorary doctorate in engineering and technology from Yale University and an Institute of Electrical and Electronics Engineers Honorary Membership. Musk was elected a Fellow of the Royal Society (FRS) in 2018.[m] In 2022, Musk was elected to the National Academy of Engineering. Time has listed Musk as one of the most influential people in the world in 2010, 2013, 2018, and 2021. Musk was selected as Time's "Person of the Year" for 2021. Then Time editor-in-chief Edward Felsenthal wrote that, "Person of the Year is a marker of influence, and few individuals have had more influence than Musk on life on Earth, and potentially life off Earth too." Notes References Works cited Further reading External links |
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Contents OpenAI OpenAI is an American artificial intelligence research organization comprising both a non-profit foundation and a controlled for-profit public benefit corporation (PBC), headquartered in San Francisco. It aims to develop "safe and beneficial" artificial general intelligence (AGI), which it defines as "highly autonomous systems that outperform humans at most economically valuable work". OpenAI is widely recognized for its development of the GPT family of large language models, the DALL-E series of text-to-image models, and the Sora series of text-to-video models, which have influenced industry research and commercial applications. Its release of ChatGPT in November 2022 has been credited with catalyzing widespread interest in generative AI. The organization was founded in 2015 in Delaware but evolved a complex corporate structure. As of October 2025, following restructuring approved by California and Delaware regulators, the non-profit OpenAI Foundation holds 26% of the for-profit OpenAI Group PBC, with Microsoft holding 27% and employees/other investors holding 47%. Under its governance arrangements, the OpenAI Foundation holds the authority to appoint the board of the for-profit OpenAI Group PBC, a mechanism designed to align the entity’s strategic direction with the Foundation’s charter. Microsoft previously invested over $13 billion into OpenAI, and provides Azure cloud computing resources. In October 2025, OpenAI conducted a $6.6 billion share sale that valued the company at $500 billion. In 2023 and 2024, OpenAI faced multiple lawsuits for alleged copyright infringement against authors and media companies whose work was used to train some of OpenAI's products. In November 2023, OpenAI's board removed Sam Altman as CEO, citing a lack of confidence in him, but reinstated him five days later following a reconstruction of the board. Throughout 2024, roughly half of then-employed AI safety researchers left OpenAI, citing the company's prominent role in an industry-wide problem. Founding In December 2015, OpenAI was founded as a not for profit organization by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, Trevor Blackwell, Vicki Cheung, Andrej Karpathy, Durk Kingma, John Schulman, Pamela Vagata, and Wojciech Zaremba, with Sam Altman and Elon Musk as the co-chairs. A total of $1 billion in capital was pledged by Sam Altman, Greg Brockman, Elon Musk, Reid Hoffman, Jessica Livingston, Peter Thiel, Amazon Web Services (AWS), and Infosys. However, the actual capital collected significantly lagged pledges. According to company disclosures, only $130 million had been received by 2019. In its founding charter, OpenAI stated an intention to collaborate openly with other institutions by making certain patents and research publicly available, but later restricted access to its most capable models, citing competitive and safety concerns. OpenAI was initially run from Brockman's living room. It was later headquartered at the Pioneer Building in the Mission District, San Francisco. According to OpenAI's charter, its founding mission is "to ensure that artificial general intelligence (AGI)—by which we mean highly autonomous systems that outperform humans at most economically valuable work—benefits all of humanity." Musk and Altman stated in 2015 that they were partly motivated by concerns about AI safety and existential risk from artificial general intelligence. OpenAI stated that "it's hard to fathom how much human-level AI could benefit society", and that it is equally difficult to comprehend "how much it could damage society if built or used incorrectly". The startup also wrote that AI "should be an extension of individual human wills and, in the spirit of liberty, as broadly and evenly distributed as possible", and that "because of AI's surprising history, it's hard to predict when human-level AI might come within reach. When it does, it'll be important to have a leading research institution which can prioritize a good outcome for all over its own self-interest." Co-chair Sam Altman expected a decades-long project that eventually surpasses human intelligence. Brockman met with Yoshua Bengio, one of the "founding fathers" of deep learning, and drew up a list of great AI researchers. Brockman was able to hire nine of them as the first employees in December 2015. OpenAI did not pay AI researchers salaries comparable to those of Facebook or Google. It also did not pay stock options which AI researchers typically get. Nevertheless, OpenAI spent $7 million on its first 52 employees in 2016. OpenAI's potential and mission drew these researchers to the firm; a Google employee said he was willing to leave Google for OpenAI "partly because of the very strong group of people and, to a very large extent, because of its mission." OpenAI co-founder Wojciech Zaremba stated that he turned down "borderline crazy" offers of two to three times his market value to join OpenAI instead. In April 2016, OpenAI released a public beta of "OpenAI Gym", its platform for reinforcement learning research. Nvidia gifted its first DGX-1 supercomputer to OpenAI in August 2016 to help it train larger and more complex AI models with the capability of reducing processing time from six days to two hours. In December 2016, OpenAI released "Universe", a software platform for measuring and training an AI's general intelligence across the world's supply of games, websites, and other applications. Corporate structure In 2019, OpenAI transitioned from non-profit to "capped" for-profit, with the profit being capped at 100 times any investment. According to OpenAI, the capped-profit model allows OpenAI Global, LLC to legally attract investment from venture funds and, in addition, to grant employees stakes in the company. Many top researchers work for Google Brain, DeepMind, or Facebook, which offer equity that a nonprofit would be unable to match. Before the transition, OpenAI was legally required to publicly disclose the compensation of its top employees. The company then distributed equity to its employees and partnered with Microsoft, announcing an investment package of $1 billion into the company. Since then, OpenAI systems have run on an Azure-based supercomputing platform from Microsoft. OpenAI Global, LLC then announced its intention to commercially license its technologies. It planned to spend $1 billion "within five years, and possibly much faster". Altman stated that even a billion dollars may turn out to be insufficient, and that the lab may ultimately need "more capital than any non-profit has ever raised" to achieve artificial general intelligence. The nonprofit, OpenAI, Inc., is the sole controlling shareholder of OpenAI Global, LLC, which, despite being a for-profit company, retains a formal fiduciary responsibility to OpenAI, Inc.'s nonprofit charter. A majority of OpenAI, Inc.'s board is barred from having financial stakes in OpenAI Global, LLC. In addition, minority members with a stake in OpenAI Global, LLC are barred from certain votes due to conflict of interest. Some researchers have argued that OpenAI Global, LLC's switch to for-profit status is inconsistent with OpenAI's claims to be "democratizing" AI. On February 29, 2024, Elon Musk filed a lawsuit against OpenAI and CEO Sam Altman, accusing them of shifting focus from public benefit to profit maximization—a case OpenAI dismissed as "incoherent" and "frivolous," though Musk later revived legal action against Altman and others in August. On April 9, 2024, OpenAI countersued Musk in federal court, alleging that he had engaged in "bad-faith tactics" to slow the company's progress and seize its innovations for his personal benefit. OpenAI also argued that Musk had previously supported the creation of a for-profit structure and had expressed interest in controlling OpenAI himself. The countersuit seeks damages and legal measures to prevent further alleged interference. On February 10, 2025, a consortium of investors led by Elon Musk submitted a $97.4 billion unsolicited bid to buy the nonprofit that controls OpenAI, declaring willingness to match or exceed any better offer. The offer was rejected on 14 February 2025, with OpenAI stating that it was not for sale, but the offer complicated Altman's restructuring plan by suggesting a lower bar for how much the nonprofit should be valued. OpenAI, Inc. was originally designed as a nonprofit in order to ensure that AGI "benefits all of humanity" rather than "the private gain of any person". In 2019, it created OpenAI Global, LLC, a capped-profit subsidiary controlled by the nonprofit. In December 2024, OpenAI proposed a restructuring plan to convert the capped-profit into a Delaware-based public benefit corporation (PBC), and to release it from the control of the nonprofit. The nonprofit would sell its control and other assets, getting equity in return, and would use it to fund and pursue separate charitable projects, including in science and education. OpenAI's leadership described the change as necessary to secure additional investments, and claimed that the nonprofit's founding mission to ensure AGI "benefits all of humanity" would be better fulfilled. The plan has been criticized by former employees. A legal letter named "Not For Private Gain" asked the attorneys general of California and Delaware to intervene, stating that the restructuring is illegal and would remove governance safeguards from the nonprofit and the attorneys general. The letter argues that OpenAI's complex structure was deliberately designed to remain accountable to its mission, without the conflicting pressure of maximizing profits. It contends that the nonprofit is best positioned to advance its mission of ensuring AGI benefits all of humanity by continuing to control OpenAI Global, LLC, whatever the amount of equity that it could get in exchange. PBCs can choose how they balance their mission with profit-making. Controlling shareholders have a large influence on how closely a PBC sticks to its mission. On October 28, 2025, OpenAI announced that it had adopted the new PBC corporate structure after receiving approval from the attorneys general of California and Delaware. Under the new structure, OpenAI's for-profit branch became a public benefit corporation known as OpenAI Group PBC, while the non-profit was renamed to the OpenAI Foundation. The OpenAI Foundation holds a 26% stake in the PBC, while Microsoft holds a 27% stake and the remaining 47% is owned by employees and other investors. All members of the OpenAI Group PBC board of directors will be appointed by the OpenAI Foundation, which can remove them at any time. Members of the Foundation's board will also serve on the for-profit board. The new structure allows the for-profit PBC to raise investor funds like most traditional tech companies, including through an initial public offering, which Altman claimed was the most likely path forward. In January 2023, OpenAI Global, LLC was in talks for funding that would value the company at $29 billion, double its 2021 value. On January 23, 2023, Microsoft announced a new US$10 billion investment in OpenAI Global, LLC over multiple years, partially needed to use Microsoft's cloud-computing service Azure. From September to December, 2023, Microsoft rebranded all variants of its Copilot to Microsoft Copilot, and they added MS-Copilot to many installations of Windows and released Microsoft Copilot mobile apps. Following OpenAI's 2025 restructuring, Microsoft owns a 27% stake in the for-profit OpenAI Group PBC, valued at $135 billion. In a deal announced the same day, OpenAI agreed to purchase $250 billion of Azure services, with Microsoft ceding their right of first refusal over OpenAI's future cloud computing purchases. As part of the deal, OpenAI will continue to share 20% of its revenue with Microsoft until it achieves AGI, which must now be verified by an independent panel of experts. The deal also loosened restrictions on both companies working with third parties, allowing Microsoft to pursue AGI independently and allowing OpenAI to develop products with other companies. In 2017, OpenAI spent $7.9 million, a quarter of its functional expenses, on cloud computing alone. In comparison, DeepMind's total expenses in 2017 were $442 million. In the summer of 2018, training OpenAI's Dota 2 bots required renting 128,000 CPUs and 256 GPUs from Google for multiple weeks. In October 2024, OpenAI completed a $6.6 billion capital raise with a $157 billion valuation including investments from Microsoft, Nvidia, and SoftBank. On January 21, 2025, Donald Trump announced The Stargate Project, a joint venture between OpenAI, Oracle, SoftBank and MGX to build an AI infrastructure system in conjunction with the US government. The project takes its name from OpenAI's existing "Stargate" supercomputer project and is estimated to cost $500 billion. The partners planned to fund the project over the next four years. In July, the United States Department of Defense announced that OpenAI had received a $200 million contract for AI in the military, along with Anthropic, Google, and xAI. In the same month, the company made a deal with the UK Government to use ChatGPT and other AI tools in public services. OpenAI subsequently began a $50 million fund to support nonprofit and community organizations. In April 2025, OpenAI raised $40 billion at a $300 billion post-money valuation, which was the highest-value private technology deal in history. The financing round was led by SoftBank, with other participants including Microsoft, Coatue, Altimeter and Thrive. In July 2025, the company reported annualized revenue of $12 billion. This was an increase from $3.7 billion in 2024, which was driven by ChatGPT subscriptions, which reached 20 million paid subscribers by April 2025, up from 15.5 million at the end of 2024, alongside a rapidly expanding enterprise customer base that grew to five million business users. The company’s cash burn remains high because of the intensive computational costs required to train and operate large language models. It projects an $8 billion operating loss in 2025. OpenAI reports revised long-term spending projections totaling approximately $115 billion through 2029, with annual expenditures projected to escalate significantly, reaching $17 billion in 2026, $35 billion in 2027, and $45 billion in 2028. These expenditures are primarily allocated toward expanding compute infrastructure, developing proprietary AI chips, constructing data centers, and funding intensive model training programs, with more than half of the spending through the end of the decade expected to support research-intensive compute for model training and development. The company's financial strategy prioritizes market expansion and technological advancement over near-term profitability, with OpenAI targeting cash-flow-positive operations by 2029 and projecting revenue of approximately $200 billion by 2030. This aggressive spending trajectory underscores both the enormous capital requirements of scaling cutting-edge AI technology and OpenAI's commitment to maintaining its position as a leader in the artificial intelligence industry. In October 2025, OpenAI completed an employee share sale of up to $10 billion to existing investors which valued the company at $500 billion. The deal values OpenAI as the most valuable privately owned company in the world—surpassing SpaceX as the world's most valuable private company. On November 17, 2023, Sam Altman was removed as CEO when its board of directors (composed of Helen Toner, Ilya Sutskever, Adam D'Angelo and Tasha McCauley) cited a lack of confidence in him. Chief Technology Officer Mira Murati took over as interim CEO. Greg Brockman, the president of OpenAI, was also removed as chairman of the board and resigned from the company's presidency shortly thereafter. Three senior OpenAI researchers subsequently resigned: director of research and GPT-4 lead Jakub Pachocki, head of AI risk Aleksander Mądry, and researcher Szymon Sidor. On November 18, 2023, there were reportedly talks of Altman returning as CEO amid pressure placed upon the board by investors such as Microsoft and Thrive Capital, who objected to Altman's departure. Although Altman himself spoke in favor of returning to OpenAI, he has since stated that he considered starting a new company and bringing former OpenAI employees with him if talks to reinstate him didn't work out. The board members agreed "in principle" to resign if Altman returned. On November 19, 2023, negotiations with Altman to return failed and Murati was replaced by Emmett Shear as interim CEO. The board initially contacted Anthropic CEO Dario Amodei (a former OpenAI executive) about replacing Altman, and proposed a merger of the two companies, but both offers were declined. On November 20, 2023, Microsoft CEO Satya Nadella announced Altman and Brockman would be joining Microsoft to lead a new advanced AI research team, but added that they were still committed to OpenAI despite recent events. Before the partnership with Microsoft was finalized, Altman gave the board another opportunity to negotiate with him. About 738 of OpenAI's 770 employees, including Murati and Sutskever, signed an open letter stating they would quit their jobs and join Microsoft if the board did not rehire Altman and then resign. This prompted OpenAI investors to consider legal action against the board as well. In response, OpenAI management sent an internal memo to employees stating that negotiations with Altman and the board had resumed and would take some time. On November 21, 2023, after continued negotiations, Altman and Brockman returned to the company in their prior roles along with a reconstructed board made up of new members Bret Taylor (as chairman) and Lawrence Summers, with D'Angelo remaining. According to subsequent reporting, shortly before Altman’s firing, some employees raised concerns to the board about how he had handled the safety implications of a recent internal AI capability discovery. On November 29, 2023, OpenAI announced that an anonymous Microsoft employee had joined the board as a non-voting member to observe the company's operations; Microsoft resigned from the board in July 2024. In February 2024, the Securities and Exchange Commission subpoenaed OpenAI's internal communication to determine if Altman's alleged lack of candor misled investors. In 2024, following the temporary removal of Sam Altman and his return, many employees gradually left OpenAI, including most of the original leadership team and a significant number of AI safety researchers. In August 2023, it was announced that OpenAI had acquired the New York-based start-up Global Illumination, a company that deploys AI to develop digital infrastructure and creative tools. In June 2024, OpenAI acquired Multi, a startup focused on remote collaboration. In March 2025, OpenAI reached a deal with CoreWeave to acquire $350 million worth of CoreWeave shares and access to AI infrastructure, in return for $11.9 billion paid over five years. Microsoft was already CoreWeave's biggest customer in 2024. Alongside their other business dealings, OpenAI and Microsoft were renegotiating the terms of their partnership to facilitate a potential future initial public offering by OpenAI, while ensuring Microsoft's continued access to advanced AI models. On May 21, OpenAI announced the $6.5 billion acquisition of io, an AI hardware start-up founded by former Apple designer Jony Ive in 2024. In September 2025, OpenAI agreed to acquire the product testing startup Statsig for $1.1 billion in an all-stock deal and appointed Statsig's founding CEO Vijaye Raji as OpenAI's chief technology officer of applications. The company also announced development of an AI-driven hiring service designed to rival LinkedIn. OpenAI acquired personal finance app Roi in October 2025. In October 2025, OpenAI acquired Software Applications Incorporated, the developer of Sky, a macOS-based natural language interface designed to operate across desktop applications. The Sky team joined OpenAI, and the company announced plans to integrate Sky’s capabilities into ChatGPT. In December 2025, it was announced OpenAI had agreed to acquire Neptune, an AI tooling startup that helps companies track and manage model training, for an undisclosed amount. In January 2026, it was announced OpenAI had acquired healthcare technology startup Torch for approximately $60 million. The acquisition followed the launch of OpenAI’s ChatGPT Health product and was intended to strengthen the company’s medical data and healthcare artificial intelligence capabilities. OpenAI has been criticized for outsourcing the annotation of data sets to Sama, a company based in San Francisco that employed workers in Kenya. These annotations were used to train an AI model to detect toxicity, which could then be used to moderate toxic content, notably from ChatGPT's training data and outputs. However, these pieces of text usually contained detailed descriptions of various types of violence, including sexual violence. The investigation uncovered that OpenAI began sending snippets of data to Sama as early as November 2021. The four Sama employees interviewed by Time described themselves as mentally scarred. OpenAI paid Sama $12.50 per hour of work, and Sama was redistributing the equivalent of between $1.32 and $2.00 per hour post-tax to its annotators. Sama's spokesperson said that the $12.50 was also covering other implicit costs, among which were infrastructure expenses, quality assurance and management. In 2024, OpenAI began collaborating with Broadcom to design a custom AI chip capable of both training and inference, targeted for mass production in 2026 and to be manufactured by TSMC on a 3 nm process node. This initiative intended to reduce OpenAI's dependence on Nvidia GPUs, which are costly and face high demand in the market. In January 2024, Arizona State University purchased ChatGPT Enterprise in OpenAI's first deal with a university. In June 2024, Apple Inc. signed a contract with OpenAI to integrate ChatGPT features into its products as part of its new Apple Intelligence initiative. In June 2025, OpenAI began renting Google Cloud's Tensor Processing Units (TPUs) to support ChatGPT and related services, marking its first meaningful use of non‑Nvidia AI chips. In September 2025, it was revealed that OpenAI signed a contract with Oracle to purchase $300 billion in computing power over the next five years. In September 2025, OpenAI and NVIDIA announced a memorandum of understanding that included a potential deployment of at least 10 gigawatts of NVIDIA systems and a $100 billion investment from NVIDIA in OpenAI. OpenAI expected the negotiations to be completed within weeks. As of January 2026, this has not been realized, and the two sides are rethinking the future of their partnership. In October 2025, OpenAI announced a multi-billion dollar deal with AMD. OpenAI committed to purchasing six gigawatts worth of AMD chips, starting with the MI450. OpenAI will have the option to buy up to 160 million shares of AMD, about 10% of the company, depending on development, performance and share price targets. In December 2025, Disney said it would make a $1 billion investment in OpenAI, and signed a three-year licensing deal that will let users generate videos using Sora—OpenAI's short-form AI video platform. More than 200 Disney, Marvel, Star Wars and Pixar characters will be available to OpenAI users. In early 2026, Amazon entered advanced discussions to invest up to $50 billion in OpenAI as part of a potential artificial intelligence partnership. Under the proposed agreement, OpenAI’s models could be integrated into Amazon’s digital assistant Alexa and other internal projects. OpenAI provides LLMs to the Artificial Intelligence Cyber Challenge and to the Advanced Research Projects Agency for Health. In October 2024, The Intercept revealed that OpenAI's tools are considered "essential" for AFRICOM's mission and included in an "Exception to Fair Opportunity" contractual agreement between the United States Department of Defense and Microsoft. In December 2024, OpenAI said it would partner with defense-tech company Anduril to build drone defense technologies for the United States and its allies. In 2025, OpenAI's Chief Product Officer, Kevin Weil, was commissioned lieutenant colonel in the U.S. Army to join Detachment 201 as senior advisor. In June 2025, the U.S. Department of Defense awarded OpenAI a $200 million one-year contract to develop AI tools for military and national security applications. OpenAI announced a new program, OpenAI for Government, to give federal, state, and local governments access to its models, including ChatGPT. Services In February 2019, GPT-2 was announced, which gained attention for its ability to generate human-like text. In 2020, OpenAI announced GPT-3, a language model trained on large internet datasets. GPT-3 is aimed at natural language answering questions, but it can also translate between languages and coherently generate improvised text. It also announced that an associated API, named the API, would form the heart of its first commercial product. Eleven employees left OpenAI, mostly between December 2020 and January 2021, in order to establish Anthropic. In 2021, OpenAI introduced DALL-E, a specialized deep learning model adept at generating complex digital images from textual descriptions, utilizing a variant of the GPT-3 architecture. In December 2022, OpenAI received widespread media coverage after launching a free preview of ChatGPT, its new AI chatbot based on GPT-3.5. According to OpenAI, the preview received over a million signups within the first five days. According to anonymous sources cited by Reuters in December 2022, OpenAI Global, LLC was projecting $200 million of revenue in 2023 and $1 billion in revenue in 2024. After ChatGPT was launched, Google announced a similar chatbot, Bard, amid internal concerns that ChatGPT could threaten Google’s position as a primary source of online information. On February 7, 2023, Microsoft announced that it was building AI technology based on the same foundation as ChatGPT into Microsoft Bing, Edge, Microsoft 365 and other products. On March 14, 2023, OpenAI released GPT-4, both as an API (with a waitlist) and as a feature of ChatGPT Plus. On November 6, 2023, OpenAI launched GPTs, allowing individuals to create customized versions of ChatGPT for specific purposes, further expanding the possibilities of AI applications across various industries. On November 14, 2023, OpenAI announced they temporarily suspended new sign-ups for ChatGPT Plus due to high demand. Access for newer subscribers re-opened a month later on December 13. In December 2024, the company launched the Sora model. It also launched OpenAI o1, an early reasoning model that was internally codenamed strawberry. Additionally, ChatGPT Pro—a $200/month subscription service offering unlimited o1 access and enhanced voice features—was introduced, and preliminary benchmark results for the upcoming OpenAI o3 models were shared. On January 23, 2025, OpenAI released Operator, an AI agent and web automation tool for accessing websites to execute goals defined by users. The feature was only available to Pro users in the United States. OpenAI released deep research agent, nine days later. It scored a 27% accuracy on the benchmark Humanity's Last Exam (HLE). Altman later stated GPT-4.5 would be the last model without full chain-of-thought reasoning. In July 2025, reports indicated that AI models by both OpenAI and Google DeepMind solved mathematics problems at the level of top-performing students in the International Mathematical Olympiad. OpenAI's large language model was able to achieve gold medal-level performance, reflecting significant progress in AI's reasoning abilities. On October 6, 2025, OpenAI unveiled its Agent Builder platform during the company's DevDay event. The platform includes a visual drag-and-drop interface that lets developers and businesses design, test, and deploy agentic workflows with limited coding. On October 21, 2025, OpenAI introduced ChatGPT Atlas, a browser integrating the ChatGPT assistant directly into web navigation, to compete with existing browsers such as Google Chrome and Apple Safari. On December 11, 2025, OpenAI announced GPT-5.2. This model will be better at creating spreadsheets, building presentations, perceiving images, writing code and understanding long context. On January 27, 2026, OpenAI introduced Prism, a LaTeX-native workspace meant to assist scientists to help with research and writing. The platform utilizes GPT-5.2 as a backend to automate the process of drafting for scientific papers, including features for managing citations, complex equation formatting, and real-time collaborative editing. In March 2023, the company was criticized for disclosing particularly few technical details about products like GPT-4, contradicting its initial commitment to openness and making it harder for independent researchers to replicate its work and develop safeguards. OpenAI cited competitiveness and safety concerns to justify this repudiation. OpenAI's former chief scientist Ilya Sutskever argued in 2023 that open-sourcing increasingly capable models was increasingly risky, and that the safety reasons for not open-sourcing the most potent AI models would become "obvious" in a few years. In September 2025, OpenAI published a study on how people use ChatGPT for everyday tasks. The study found that "non-work tasks" (according to an LLM-based classifier) account for more than 72 percent of all ChatGPT usage, with a minority of overall usage related to business productivity. In July 2023, OpenAI launched the superalignment project, aiming within four years to determine how to align future superintelligent systems. OpenAI promised to dedicate 20% of its computing resources to the project, although the team denied receiving anything close to 20%. OpenAI ended the project in May 2024 after its co-leaders Ilya Sutskever and Jan Leike left the company. In August 2025, OpenAI was criticized after thousands of private ChatGPT conversations were inadvertently exposed to public search engines like Google due to an experimental "share with search engines" feature. The opt-in toggle, intended to allow users to make specific chats discoverable, resulted in some discussions including personal details such as names, locations, and intimate topics appearing in search results when users accidentally enabled it while sharing links. OpenAI announced the feature's permanent removal on August 1, 2025, and the company began coordinating with search providers to remove the exposed content, emphasizing that it was not a security breach but a design flaw that heightened privacy risks. CEO Sam Altman acknowledged the issue in a podcast, noting users often treat ChatGPT as a confidant for deeply personal matters, which amplified concerns about AI handling sensitive data. Management In 2018, Musk resigned from his Board of Directors seat, citing "a potential future conflict [of interest]" with his role as CEO of Tesla due to Tesla's AI development for self-driving cars. OpenAI stated that Musk's financial contributions were below $45 million. On March 3, 2023, Reid Hoffman resigned from his board seat, citing a desire to avoid conflicts of interest with his investments in AI companies via Greylock Partners, and his co-founding of the AI startup Inflection AI. Hoffman remained on the board of Microsoft, a major investor in OpenAI. In May 2024, Chief Scientist Ilya Sutskever resigned and was succeeded by Jakub Pachocki. Co-leader Jan Leike also departed amid concerns over safety and trust. OpenAI then signed deals with Reddit, News Corp, Axios, and Vox Media. Paul Nakasone then joined the board of OpenAI. In August 2024, cofounder John Schulman left OpenAI to join Anthropic, and OpenAI's president Greg Brockman took extended leave until November. In September 2024, CTO Mira Murati left the company. In November 2025, Lawrence Summers resigned from the board of directors. Governance and legal issues In May 2023, Sam Altman, Greg Brockman and Ilya Sutskever posted recommendations for the governance of superintelligence. They stated that superintelligence could happen within the next 10 years, allowing a "dramatically more prosperous future" and that "given the possibility of existential risk, we can't just be reactive". They proposed creating an international watchdog organization similar to IAEA to oversee AI systems above a certain capability threshold, suggesting that relatively weak AI systems on the other side should not be overly regulated. They also called for more technical safety research for superintelligences, and asked for more coordination, for example through governments launching a joint project which "many current efforts become part of". In July 2023, the FTC issued a civil investigative demand to OpenAI to investigate whether the company's data security and privacy practices to develop ChatGPT were unfair or harmed consumers (including by reputational harm) in violation of Section 5 of the Federal Trade Commission Act of 1914. These are typically preliminary investigative matters and are nonpublic, but the FTC's document was leaked. In July 2023, the FTC launched an investigation into OpenAI over allegations that the company scraped public data and published false and defamatory information. They asked OpenAI for comprehensive information about its technology and privacy safeguards, as well as any steps taken to prevent the recurrence of situations in which its chatbot generated false and derogatory content about people. The agency also raised concerns about ‘circular’ spending arrangements—for example, Microsoft extending Azure credits to OpenAI while both companies shared engineering talent—and warned that such structures could negatively affect the public. In September 2024, OpenAI's global affairs chief endorsed the UK's "smart" AI regulation during testimony to a House of Lords committee. In February 2025, OpenAI CEO Sam Altman stated that the company is interested in collaborating with the People's Republic of China, despite regulatory restrictions imposed by the U.S. government. This shift comes in response to the growing influence of the Chinese artificial intelligence company DeepSeek, which has disrupted the AI market with open models, including DeepSeek V3 and DeepSeek R1. Following DeepSeek's market emergence, OpenAI enhanced security protocols to protect proprietary development techniques from industrial espionage. Some industry observers noted similarities between DeepSeek's model distillation approach and OpenAI's methodology, though no formal intellectual property claim was filed. According to Oliver Roberts, in March 2025, the United States had 781 state AI bills or laws. OpenAI advocated for preempting state AI laws with federal laws. According to Scott Kohler, OpenAI has opposed California's AI legislation and suggested that the state bill encroaches on a more competent federal government. Public Citizen opposed a federal preemption on AI and pointed to OpenAI's growth and valuation as evidence that existing state laws have not hampered innovation. Before May 2024, OpenAI required departing employees to sign a lifelong non-disparagement agreement forbidding them from criticizing OpenAI and acknowledging the existence of the agreement. Daniel Kokotajlo, a former employee, publicly stated that he forfeited his vested equity in OpenAI in order to leave without signing the agreement. Sam Altman stated that he was unaware of the equity cancellation provision, and that OpenAI never enforced it to cancel any employee's vested equity. However, leaked documents and emails refute this claim. On May 23, 2024, OpenAI sent a memo releasing former employees from the agreement. OpenAI was sued for copyright infringement by authors Sarah Silverman, Matthew Butterick, Paul Tremblay and Mona Awad in July 2023. In September 2023, 17 authors, including George R. R. Martin, John Grisham, Jodi Picoult and Jonathan Franzen, joined the Authors Guild in filing a class action lawsuit against OpenAI, alleging that the company's technology was illegally using their copyrighted work. The New York Times also sued the company in late December 2023. In May 2024 it was revealed that OpenAI had destroyed its Books1 and Books2 training datasets, which were used in the training of GPT-3, and which the Authors Guild believed to have contained over 100,000 copyrighted books. In 2021, OpenAI developed a speech recognition tool called Whisper. OpenAI used it to transcribe more than one million hours of YouTube videos into text for training GPT-4. The automated transcription of YouTube videos raised concerns within OpenAI employees regarding potential violations of YouTube's terms of service, which prohibit the use of videos for applications independent of the platform, as well as any type of automated access to its videos. Despite these concerns, the project proceeded with notable involvement from OpenAI's president, Greg Brockman. The resulting dataset proved instrumental in training GPT-4. In February 2024, The Intercept as well as Raw Story and Alternate Media Inc. filed lawsuit against OpenAI on copyright litigation ground. The lawsuit is said to have charted a new legal strategy for digital-only publishers to sue OpenAI. On April 30, 2024, eight newspapers filed a lawsuit in the Southern District of New York against OpenAI and Microsoft, claiming illegal harvesting of their copyrighted articles. The suing publications included The Mercury News, The Denver Post, The Orange County Register, St. Paul Pioneer Press, Chicago Tribune, Orlando Sentinel, Sun Sentinel, and New York Daily News. In June 2023, a lawsuit claimed that OpenAI scraped 300 billion words online without consent and without registering as a data broker. It was filed in San Francisco, California, by sixteen anonymous plaintiffs. They also claimed that OpenAI and its partner as well as customer Microsoft continued to unlawfully collect and use personal data from millions of consumers worldwide to train artificial intelligence models. On May 22, 2024, OpenAI entered into an agreement with News Corp to integrate news content from The Wall Street Journal, the New York Post, The Times, and The Sunday Times into its AI platform. Meanwhile, other publications like The New York Times chose to sue OpenAI and Microsoft for copyright infringement over the use of their content to train AI models. In November 2024, a coalition of Canadian news outlets, including the Toronto Star, Metroland Media, Postmedia, The Globe and Mail, The Canadian Press and CBC, sued OpenAI for using their news articles to train its software without permission. In October 2024 during a New York Times interview, Suchir Balaji accused OpenAI of violating copyright law in developing its commercial LLMs which he had helped engineer. He was a likely witness in a major copyright trial against the AI company, and was one of several of its current or former employees named in court filings as potentially having documents relevant to the case. On November 26, 2024, Balaji died by suicide. His death prompted the circulation of conspiracy theories alleging that he had been deliberately silenced. California Congressman Ro Khanna endorsed calls for an investigation. On April 24, 2025, Ziff Davis sued OpenAI in Delaware federal court for copyright infringement. Ziff Davis is known for publications such as ZDNet, PCMag, CNET, IGN and Lifehacker. In April 2023, the EU's European Data Protection Board (EDPB) formed a dedicated task force on ChatGPT "to foster cooperation and to exchange information on possible enforcement actions conducted by data protection authorities" based on the "enforcement action undertaken by the Italian data protection authority against OpenAI about the ChatGPT service". In late April 2024 NOYB filed a complaint with the Austrian Datenschutzbehörde against OpenAI for violating the European General Data Protection Regulation. A text created with ChatGPT gave a false date of birth for a living person without giving the individual the option to see the personal data used in the process. A request to correct the mistake was denied. Additionally, neither the recipients of ChatGPT's work nor the sources used, could be made available, OpenAI claimed. OpenAI was criticized for lifting its ban on using ChatGPT for "military and warfare". Up until January 10, 2024, its "usage policies" included a ban on "activity that has high risk of physical harm, including", specifically, "weapons development" and "military and warfare". Its new policies prohibit "[using] our service to harm yourself or others" and to "develop or use weapons". In August 2025, the parents of a 16-year-old boy who died by suicide filed a wrongful death lawsuit against OpenAI (and CEO Sam Altman), alleging that months of conversations with ChatGPT about mental health and methods of self-harm contributed to their son's death and that safeguards were inadequate for minors. OpenAI expressed condolences and said it was strengthening protections (including updated crisis response behavior and parental controls). Coverage described it as a first-of-its-kind wrongful death case targeting the company's chatbot. The complaint was filed in California state court in San Francisco. In November 2025, the Social Media Victims Law Center and Tech Justice Law Project filed seven lawsuits against OpenAI, of which four lawsuits alleged wrongful death. The suits were filed on behalf of Zane Shamblin, 23, of Texas; Amaurie Lacey, 17, of Georgia; Joshua Enneking, 26, of Florida; and Joe Ceccanti, 48, of Oregon, who each committed suicide after prolonged ChatGPT usage. In December 2025, Stein-Erik Soelberg, who was 56 years old at the time, allegedly murdered his mother Suzanne Adams. In the months prior the paranoid, delusional man often discussed his ideas with ChatGPT. Adam's estate then sued OpenAI claiming that the company shared responsibility due to the risk of chatbot psychosis despite the fact that chatbot psychosis is not a real medical diagnosis. OpenAI responded saying they will make ChatGPT safer for users disconnected from reality. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/History_of_the_Jews_in_Iraq] | [TOKENS: 17326] |
Contents History of the Jews in Iraq The history of the Jews in Iraq is documented from the time of Babylonian captivity (c. 586 BCE). Iraqi Jews (al-Yahūd al-ʿIrāqiyyūn), also known as Bavlim (Hebrew: יְהוּדִים בָּבְלִים, Yəhūḏīm Bāḇəlīm, lit. 'Babylonian Jews'), constitute one of the world's oldest and most historically significant Jewish communities. The Jewish community in Mesopotamia, known in Jewish sources as "Babylonia", traces its origins to the early sixth century BCE, when a large number of Judeans from the defeated Kingdom of Judah were exiled to Babylon in several waves by the Neo-Babylonian Empire. A few decades later, some had returned to Judah, following the edict of Cyrus. During this time, the Temple in Jerusalem was rebuilt, significant changes in Jewish religious tradition were made, and the Judeans were led by individuals who had returned from Babylonia, such as Zerubbabel, Ezra and Nehemiah. Though not much is known about the community in Babylonia during the Second Temple and Mishnaic periods, scholars believe the community was still thriving at that time. The Jewish community of Babylonia rose to prominence as the center of Jewish scholarship following the decline of the Jewish population in the Land of Israel in the 3rd century CE. Estimates often place the Babylonian Jewish population of the third to seventh centuries at around one million, making it the largest Jewish diaspora community of that period. The area became home to many important Talmudic yeshivas such as the Nehardea, Pumbedita and Sura Academies, and the Babylonian Talmud was compiled there. The Mongol invasion and Islamic discrimination under the caliphates in the Middle Ages eventually led to the decline of the region's Jewish community. Under the Ottoman Empire, the Jews of Ottoman Iraq fared better. The community established modern schools in the second half of the 19th century. Driven by persecution, which saw many of the leading Jewish families of Baghdad flee for India, and expanding trade with British colonies, the Jews of Iraq established a trading diaspora in Asia known as the Baghdadi Jews. The Iraqi Jewish community formed a homogeneous group, maintaining communal Jewish identity, culture and traditions. The Jews in Iraq distinguished themselves by the way they spoke in their old Arabic dialect, Judeo-Arabic; the way they dressed; observation of Jewish rituals, for example, the Sabbath and holidays; and kashrut. In the 20th century, Iraqi Jews played an important role in the early days of Iraq's independence. According to Avi Shlaim, they were deeply integrated into the wider Iraqi society, culturally and linguistically. Jews held many positions in the Ministry of Finance, Public Accounting, Public Works, Communications, Post and Telegraph, Basra Port, Railways, and Customs, and the departments of the Ministry of Interior, Education, Health, Police, and Defense were not without them. At the beginning of the 20th century Jews formed a notable presence in the country's main cities, including up to 40% in Baghdad and 25% in Basra. In 1941, the Farhud ("violent dispossession"), a major pogrom, occurred in Baghdad, in which 200 Jews or more were murdered. Following the 1948 Arab–Israeli War, persecution against Jews culminated in increased government oppression and cultural discrimination. The government, while maintaining a public policy of discrimination against Jews, simultaneously forbade Jews from emigrating to Israel out of concern for strengthening the nascent Israeli state. In 1950, the government reversed course and permitted Jews to emigrate in exchange for renouncing their citizenship. From 1950 to 1952, nearly the entire Iraqi Jewish population emptied out from Iraq to Israel through Operation Ezra and Nehemiah. Historians estimate that 120,000–130,000 Iraqi Jews (around 75% of the entire community) reached Israel. In the early years, the Ba'ath Party had a dual approach toward Jews. On one hand, Jews were detained, imprisoned, tortured, and even executed on charges of spying for Israel. On the other hand, some government officials displayed personal sympathy and leniency toward them. Many Jews managed to convince the authorities to release detainees. The era of Abdul-Karim Qasim was generally considered better for Jews compared to the rule of Ahmed Hassan al-Bakr. During this period, a significant number of Jews fled the country, causing a sharp decline in the Jewish population. Eventually, overt repression eased, and Jews were treated more fairly. When Saddam Hussein rose to power, he repealed many antisemitic laws and policies. Under his rule, the Jewish population continued to dwindle—not due to persecution but because travel restrictions were lifted. Many Jews took advantage of this freedom to travel between Iraq and foreign countries, a practice that became routine. Those who settled abroad during this time retained their Iraqi citizenship. Additionally, several Jews served in government roles during his regime. The remainder of the Jewish population continued to dwindle in the ensuing decades; as of 2014, the total number of Jews living in Iraq numbered around 500, mostly in Baghdad and Kurdistan region. The religious and cultural traditions of Iraqi Jews are kept alive today in strong communities established by Iraqi Jews in Israel, especially in Or Yehuda, Givatayim and Kiryat Gat. According to government data as of 2014, there were 227,900 Jews of Iraqi descent in Israel, with other estimates as high as 600,000 Israelis having some Iraqi ancestry. Smaller communities upholding Iraqi Jewish traditions in the Jewish diaspora exist in the United Kingdom, Ireland, Australia, Singapore, Canada, and the United States. The term "Babylonia" What Jewish sources called "Babylon" and "Babylonia" may refer to the ancient city of Babylon and the Neo-Babylonian Empire; or, very often, it means the specific area of Mesopotamia (the region between the Tigris and the Euphrates rivers) where a number of Jewish religious academies functioned during the Geonic period (6th–11th century CE). Early Biblical history Abraham, the patriarch of the Hebrews, originated from Mesopotamia. The Ten Israelite Tribes from the northern Kingdom of Israel were exiled to Assyria from 730 BCE. In the Bible, Babylon and the country of Babylonia are not always clearly distinguished; in most cases, the same word is used in reference to both places. In some passages, the land of Babylonia is called Shinar, while in the post-exilic literature, it is called Chaldea. In the Book of Genesis, Babylonia is described as the land in which Babel, Erech, Accad, and Calneh are located – cities that are declared to have formed the beginning of Nimrod's kingdom (Genesis 10:10). Here, the Tower of Babel was located (Gen. 11:1–9); and it was also the seat of Amraphel's dominion (Gen. 14:1, 9). In the historical books, Babylonia is frequently referred to (there are no fewer than thirty-one allusions in the Books of Kings), though the lack of a clear distinction between the city and the country is sometimes puzzling. Allusions to it are confined to the points of contact between the Israelites and the various Babylonian kings, especially Merodach-baladan (Berodach-baladan of 2 Kings 20:12; compare Isa. 34:1) and Nebuchadnezzar. In Books of Chronicles, Ezra, and Nehemiah the interest is transferred to Cyrus (see, for example, Ez. 5:13), though the retrospect still deals with the conquests of Nebuchadnezzar, and Artaxerxes is mentioned once (Neh. 13:6). In the poetical literature of Israel, Babylonia plays an insignificant part (see Ps. 87:4, and especially Psalm 137), but it fills a very large place in the Prophets. The Book of Isaiah resounds with the "burden of Babylon" (Isaiah 13:1), though at that time it still seemed a "far country" (Isaiah 39:3). In the number and importance of its references to Babylonian life and history, the Book of Jeremiah stands preeminent in the Hebrew literature. With numerous important allusions to events in the reign of Nebuchadnezzar, Jeremiah has become a valuable source in reconstructing Babylonian history within recent times. The inscriptions of Nebuchadnezzar are almost exclusively devoted to building operations; and but for the Book of Jeremiah, little would be known of his campaign against Jerusalem. Babylonian captivity and return to Zion During the 6th century BCE, the Jews of the ancient Kingdom of Judah were exiled to Babylon by Nebuchadnezzar in three waves. These three separate occasions are mentioned in the Book of Jeremiah (Jer. 52:28–30). The first was in the time of Jehoiachin in 597 BCE, when, in retaliation for a refusal to pay tribute, the First Temple in Jerusalem was partially despoiled and a number of the leading citizens removed (Book of Daniel, Daniel 5:1–5). After eleven years, in the reign of Zedekiah—who had been enthroned by Nebuchadnezzar—a fresh revolt of the Judaeans took place, perhaps encouraged by the close proximity of the Egyptian army. The city was razed to the ground, and a further deportation ensued. Five years later, Jeremiah records a third captivity. After the overthrow of Babylonia by the Persians, Cyrus gave the Jews permission to return to their native land (537 BCE), and more than forty thousand are said to have availed themselves of the privilege. (See Jehoiakim; Ezra; Nehemiah.) The earliest accounts of the Jews exiled to Babylonia are furnished only by scanty biblical details, although a number of archaeological discoveries (such as the Al-Yahudu Tablets) shed light into the social lives of the deportees; certain sources seek to supply this deficiency from the realms of legend and tradition. Thus, the so-called "Small Chronicle" (Seder Olam Zutta) endeavors to preserve historic continuity by providing a genealogy of the exilarchs ("Reshe Galuta") back to King Jeconiah. Jeconiah himself is made an exilarch. The "Small Chronicle" states that Zerubbabel returned to Judea in the Greek period. Certainly, the descendants of the Davidic line occupied an exalted position among their brethren in Babylonia, as they did at that period in Judea. During the Maccabean revolt, these Judean descendants of the royal house had immigrated to Babylonia. According to the biblical account, the Persian emperor Cyrus the Great was "God's anointed", having freed the Jews from Babylonian rule. After the conquest of Babylonia by the Persian Achaemenid Empire Cyrus granted all the Jews citizenship and by decree allowed the Jews to return to Israel (around 537 BCE). Subsequently, successive waves of Babylonian Jews emigrated to Israel. Ezra (fl. 480–440 BCE) returned from Babylonian exile and reintroduced the Torah in Jerusalem (Ezra 7–10 and Nehemiah 8). During the Second Temple period two large Jewish communities developed in Mesopotamia: one in northern Mesopotamia who attributed their ancestry to the Ten Lost Tribes, and one in central Mesopotamia associated with the Judean exiles. The continuity of Jewish culture in Babylonia across the centuries is indicated by certain names which appear among Babylonian Jews in Ezra-Nehemiah and centuries later among Babylonian amoraim, but never in Judean sources, such as Shereviah. Hellenistic period Information regarding the early period of Jewish history in Iraq is extremely limited. But with Alexander the Great's campaign, some accurate information concerning the Jews in the East reached the western world. Alexander's army contained numerous Jews who refused, from religious scruples, to take part in the reconstruction of the destroyed Belus temple in Babylon. The accession of Seleucus Nicator, 312 BCE, to whose extensive empire Babylonia belonged, was accepted by the Jews and Syrians for many centuries as the commencement of a new era for reckoning time, called the Seleucid era, or in Jewish sources "minyan sheṭarot" (era of contracts), which was also officially adopted by the Parthians. Nicator's foundation of a city, Seleucia, on the Tigris is mentioned by the Rabbis; both the "Large" and the "Small Chronicle" contain references to him. The important victory which the Jews are said to have gained over the Galatians in Babylonia (see II Maccabees – 2 Macc. 8:20) must have happened under Seleucus Callinicus or under Antiochus III. The last-named settled a large number of Babylonian Jews as colonists in his western dominions, with the view of checking certain revolutionary tendencies disturbing those lands. The persecutions of Antiochus IV (168 BCE) appear to have been limited to Judea, and likely were not imposed on Babylonian Jews. Parthian period Mithridates (174–136 BCE) subjugated, about the year 160, the province of Babylonia, and thus the Jews for four centuries came under Parthian domination. Jewish sources contain no mention of Parthian influence; the very name "Parthian" does not occur, unless "Parthian" is meant by "Persian", which occurs now and then. The Armenian prince Sanatroces, of the royal house of the Arsacides, is mentioned in the "Small Chronicle" as one of the successors (diadochoi) of Alexander. Among other Asiatic princes, the Roman rescript in favor of the Jews reached Arsaces as well (I Macc. 15:22); it is not, however, specified which Arsaces. Not long after this, the Partho-Babylonian country was trodden by the army of a Jewish prince. The Syrian king, Antiochus VII Sidetes, in company with Hyrcanus I, marched against the Parthians. When the allied armies defeated the Parthians (129 BCE) at the Great Zab (Lycus), the king ordered a halt of two days on account of the Jewish Sabbath and Feast of Weeks. In 40 BCE the Jewish puppet-king, Hyrcanus II, fell into the hands of the Parthians, who, according to their custom, cut off his ears to render him unfit for rulership. The Jews of Babylonia, it seems, had the intention of founding a high-priesthood for the exiled Hyrcanus, which they would have made quite independent of Judea. But the reverse was to come about: the Judeans received a Babylonian, Ananel by name, as their high priest which indicates the importance enjoyed by the Jews of Babylonia. Philo speaks of the large number of Jews resident in that country, a population which was no doubt considerably swelled by new immigrants after the First Jewish-Roman War (66–73 CE). How free a hand the Parthians permitted the Jews is perhaps best illustrated by the rise of the little Jewish robber-state in Nehardea (see Anilai and Asinai). Still more remarkable is the conversion of the king of Adiabene to Judaism. These instances show not only the tolerance, but the weakness of the Parthian kings. The Babylonian Jews wanted to fight in common cause with their Judean brethren against Vespasian; but it was not until Trajan's Parthian campaign that they made their hatred felt; so that it was in a great measure owing to the revolt of the Babylonian Jews that the Romans did not become masters of Babylonia too. At the height of the war, Jerusalem and the Second Temple were destroyed. These events caused a wide dispersion of Jews in which many probably ended up in Babylonia. The Jews of Babylon would for the first time write prayers in a language other than Hebrew, such as the Kaddish, written in Judeo-Aramaic – a harbinger of the many languages in which Jewish prayers in the diaspora would come to be written in, such as Greek, Arabic, and Turkish. Accustomed in Jerusalem from early times to look to the east for help, and aware, as the Roman procurator Petronius was, that the Jews of Babylon could render effectual assistance, Babylonia became with the fall of Jerusalem the very bulwark of Judaism. The collapse of the Bar Kochba revolt no doubt added to the number of Jewish refugees in Babylon. In the continuous Roman–Persian Wars, the Jews had every reason to hate the Romans, the destroyers of their sanctuary, and to side with the Parthians, their protectors. Possibly it was recognition of services thus rendered by the Jews of Babylonia, and by the Davidic house especially, that induced the Parthian kings to elevate the princes of the Exile, who until then had been little more than mere collectors of revenue, to the dignity of real princes, called Resh Galuta. Thus, then, the numerous Jewish subjects were provided with a central authority which assured an undisturbed development of their own internal affairs. In religious matters the Babylonians, like the whole diaspora, were in many regards dependent upon Judea. They went on pilgrimages to Jerusalem for the festivals, and were dependent on Judean authorities to fix the calendar. The early rabbis took for granted that their rulings would be followed in Babylonia as well as locally. That said, the influence was to some extent mutual: a number of early notable rabbis including Hillel the Elder, Nahum the Mede, and Nathan the Babylonian had ancestry in Babylonia or further east. In the 2nd century, Nisibis ("Netzivin") was such a center of rabbinic scholarship that figures like Eleazar ben Shammua could consider traveling there to study. The Jews of northern Babylonia appear to have suffered severely from the Roman-Parthian and Roman-Sasanian wars; this, and possibly the growing power of Christianity in the area, appear to have led to a weakening of the Jewish community in northern Mesopotamia while the center of Jewish culture shifted to the center and south. Sasanian period A new ruling family from an ancient dynasty of Iranian priests took control of the region around 223 CE and imposed a new system of government based on Zoroastrianism and local Iranian identity, which often suppressed dissident factions and heterodox views. It dominated the area until the Muslim conquest in the seventh century CE and became known as the Sasanian Empire. During the 3rd to 7th centuries, the Babylonian Jewish community is estimated to have reached about one million, potentially making it the largest Jewish diaspora population of the time and possibly surpassing the Jewish population in the Land of Israel during the same period. The Babylonian Talmud was written during this time and is a source of information for the political, religious, social, and linguistic facets of the empire. Under the Sasanians, Babylonia became the province of Asoristan, with its main city, Ctesiphon, becoming the capital of the Empire. Although there were some tensions between the Jewish community and Zoroastrian priests who sought to unify the entire empire under one religion and were less tolerant than their forebears during the early Sasanian era, the Jewish community's stature and their religious and communal autonomy were generally maintained. The Jewish communities in Mesopotamia flourished, particularly in the fourth century CE, as a result of Shapur's tolerant rule and the Christianization of the Roman Empire, which led to a large Jewish migration from Roman-controlled territory into the only Roman-independent region, the Sasanian Empire. While occasionally there were disputes between Jews and the authorities, the Talmudic texts mainly show respect for the Sasanian government, and the Amora Samuel of Nehardea's remark – "dina demalchuta dina" (The law of the kingdom, the governing empire, must be upheld) reflects this attitude. Shapur I (Shvor Malka, which is the Aramaic form of the name) was a friend to the Jews. His friendship with Shmuel gained many advantages for the Jewish community. Shapur II's mother was Jewish,[citation needed] and this gave the Jewish community a relative freedom of religion and many advantages. Shapur was also the friend of a Babylonian rabbi in the Talmud called Raba, and Raba's friendship with Shapur II enabled him to secure a relaxation of the oppressive laws enacted against the Jews in the Persian Empire. In addition, Raba sometimes referred to his top student Abaye with the term Shvur Malka meaning "Shapur [the] King" because of his bright and quick intellect. Christians, Manicheans, Buddhists and Jews at first seemed at a disadvantage, especially under Sasanian high-priest Kartir; but the Jews, dwelling in more compact masses in cities like Isfahan, were not exposed to such general discrimination as broke out against the more isolated Christians. The Sasanian period witnessed the flourishing of Jewish culture in Babylonia, and the beginning of a long period in which Babylonian Jewry took the lead in Jewish culture worldwide. A landmark in this process was the emigration of Rav from the Galilee, where he had studied with Judah HaNasi (author of the Mishnah), to Babylonia in 219 CE. The Jewish community of Babylonia was already learned, but Rav focused and organised their study. Leaving an existing Babylonian academy at Nehardea for his colleague Samuel, Rav founded a new academy at Sura, where he and his family already owned property, and which was known as a Jewish city. Rav's move created an environment in which Babylon had two contemporary leading academies that competed with one another, yet were so far removed from one another that they could never interfere with each other's operations. Since Rav and Samuel were acknowledged peers in position and learning, their academies likewise were considered of equal rank and influence. Their relationship can be compared to that between the Jerusalemite academies of the Houses of Hillel and Shammai, albeit Rav and Samuel agreed with each other far more often than did the houses of Hillel and Shammai. Thus, both Babylonian rabbinical schools opened a new era for diaspora Judaism, and the ensuing discussions in their classes furnished the earliest stratum and style of the scholarly material deposited in the Babylonian Talmud. The key work of these semi-competing academies was the compilation of the Babylonian Talmud (the discussions from these two cities), completed by Rav Ashi and Ravina, two successive leaders of the Babylonian Jewish community, around the year 520, though rougher copies had already been circulated to the Jews of the Byzantine Empire. Editorial work by the Savoraim or Rabbanan Savoraei (post-Talmudic rabbis), continued on this text's grammar for the next 250 years; much of the text did not reach its "perfected" form until around 600–700. The Mishnah, which had been completed in the early 3rd century CE, and the Babylonian Gemara (the discussions at and around these academies) together form the Talmud Bavli (the "Babylonian Talmud"). Jewish tradition to this day overwhelmingly relies on the Babylonian Talmud, composed by Babylonian scholars during this period, rather than the Jerusalem Talmud composed in the same period in the Galilee. The three centuries in the course of which the Babylonian Talmud was developed in the academies founded by Rav and Samuel were followed by five centuries during which it was intensely preserved, studied, expounded in the schools, and, through their influence, discipline and work, recognized by the whole diaspora. Sura, Nehardea, and Pumbedita were considered the seats of diaspora learning; and the heads of these authorities were referred to later on as Geonim and were considered the highest authorities on religious matters in the Jewish world. Their decisions were sought from all sides and were accepted wherever diaspora Jewish communal life existed. They even successfully competed against the learning coming from the Land of Israel itself. According to the rabbis, God created these two academies in order to ensure the fulfillment of the Biblical promise that the word of God would never depart from Israel's mouth (Isaiah 59:21). The periods of Jewish history immediately following the close of the Talmud are designated according to the titles of the teachers at Sura and Pumbedita; thus we have the time of the Geonim and that of the Saboraim. The Saboraim were the scholars whose diligent hands completed the Talmud and the first great Talmudic commentaries in the first third of the 6th century. The two academies among others, and the Jewish community they led, lasted until the middle of the 11th century. Pumbedita faded after its chief rabbi was murdered in 1038, and Sura faded soon after. Which ended the centuries-long great scholarly reputation given to Babylonian Jews, as the center of Jewish thought. Islamic Arab period The Arabs conquered Iraq from the Sassanids in the 630s. Ali made Kufa, in Iraq, his capital, and it was there that Jews expelled from the Arabian Peninsula went (about 641). The capture by Ali of Firuz Shabur, where 90,000 Jews are said to have dwelt, is mentioned by the Jewish chroniclers. Mar Isaac, chief of the academy of Sura, paid homage to the caliph, and received privileges from him. The first legal expression of Islam toward the dhimmis (Jews, Christians, and Zoroastrians) after the conquests were the institution of the poll-tax ("jizyah") and the tax upon real estate ("kharaj"). The kharaj land tax led to mass migration of Babylonian Jews from the countryside to cities like Baghdad. This in turn led to greater wealth and international influence, as well as a more cosmopolitan outlook from Jewish thinkers such as Saadiah Gaon, who now deeply engaged with Western philosophy for the first time. The Umayyad caliph, Umar ibn Abd al-Aziz (717–720), issued orders to his governors: "Tear down no church, synagogue, or fire-temple; but permit no new ones to be built". Isaac Iskawi II (about 800) received from Harun al-Rashid (786–809) confirmation of the right to carry a seal of office. At the court of the Harun an embassy from the emperor Charlemagne included which a Jew, Isaac, took part. In 850, al-Rashid's grandson al-Muttawakil issued a decree according to which all dhimmis (including the Jews) would need to wear in addition to the already established zunnar a honey-coloured outer garment and badge-like patches on their servant's clothing, by which he began the long tradition of differentiation by colour. Like the Arabs, the Jews were zealous promoters of knowledge, and by translating Greek and Latin The caliph al-Mu'tadid (892–902) ranked the Jews as "state servants". When the Abbasid Caliphate and the city of Baghdad declined in the 10th century, many Babylonian Jews migrated to the Mediterranean region, contributing to the spread of Babylonian Jewish customs throughout the Jewish world. Under the Seljuk Empire, new decrees enforcing discriminatory dress laws for non-Muslims were promulgated in 1091 by Abu Shuja al-Rudhrawari and in 1121 under sultan Mahmud II. As was often the case throughout Islamic history, the non-Muslims agreed to pay a substantial sum of money to the sultan so that decree be not enforced. Mongol period The Caliphate hastened to its end before the rising power of the Mongol Empire. As Bar Hebraeus remarks, these Mongol tribes knew no distinction between heathens, Jews, and Christians; and their Great Khan Kublai Khan showed himself just toward the Jews who served in his army, as reported by Marco Polo. Iraq's Jewish community reached an apex in the 12th century, with 40,000 Jews, 28 synagogues, and ten yeshivot, or Rabbinic academies. Jews participated in commerce, artisanal labor and medicine. Under Mongol rule (1258–1335) Jewish physician Sa'ad Al-Dawla served as musharrif, or assistant director of the financial administration of Baghdad, as well as Chief Vizier of the Mongol Empire. Hulagu (a Buddhist), the destroyer of the Caliphate (1258) and the conqueror of Palestine (1260), was tolerant toward Muslims, Jews and Christians; but there can be no doubt that in those days of terrible warfare the Jews must have suffered much with others. Under the Mongolian rulers, the priests of all religions were exempt from the poll-tax. Hulagu's second son, Aḥmed, embraced Islam, but his successor, Arghun (1284–1291), hated the Muslims and was friendly to Jews and Christians; his chief counselor was a Jew, Sa'ad al-Dawla, a physician of Baghdad. It proved a false dawn. The power of Sa’ad al-Dawla was so vexatious to the Muslim population the churchman Bar Hebraeus wrote so "were the Muslims reduced to having a Jew in the place of honor." This was exacerbated by Sa’d al-Dawla, who ordered no Muslim be employed by the official bureaucracy. He was also known as a fearsome tax collection and rumours swirled he was planning to create a new religion of which Arghun was supposed to be the prophet. Sa’d al-Dawla was murdered two days before the death of his Arghun, then stricken by illness, by his enemies in court. After the death of the great khan and the murder of his Jewish favorite, the Muslims fell upon the Jews, and Baghdad witnessed a regular battle between them. Gaykhatu also had a Jewish minister of finance, Reshid al-Dawla. The khan Ghazan also became a Muslim, and made the Jews second class citizens. The Egyptian sultan Naṣr, who also ruled over Iraq, reestablished the same law in 1330, and saddled it with new limitations. During this period attacks on Jews greatly increased. The situation grew dire for the Jewish community as Muslim chronicler Abbas al-’Azzawi recorded: "These events which befell the Jews after they had attained a high standing in the state caused them to lower their voices. [Since then] we have not heard from them anything worthy of recording because they were prevented from participation in its government and politics. They were neglected and their voice was only heard [again] after a long time." Baghdad, reduced in importance, ravaged by wars and invasions, was eclipsed as the commercial and political centre of the Arab world. The Jewish community, shuttered out of political life, were reduced too and the status of the Exilarch and the Rabbis of the city diminished. Great numbers of Jews began to depart, seeking tranquility elsewhere in the Middle East beyond a now troubled frontier. Mongolian fury once again devastated the localities inhabited by Jews, when, in 1393, Timur captured Baghdad, Wasit, Hilla, Basra, and Tikrit, after obstinate resistance. Many Jews who had fled to Baghdad were slaughtered. Others escaped the city to Kurdistan and Syria. Many were not so fortunate, with one report mentioning 10,000 Jews killed in Mosul, Basra, and Husun Kifa. The ruins of Baghdad after Timur's conquests was described in 1437 by the Muslim chronicler Al-Maqrizi: "Baghdad is in ruins. It has no mosque, no congregation of believers, no call to prayer and no markets. Most of the date palms have withered. Most of the irrigation canals are blocked. It cannot be called a city." After the death of Timur, the region fell into the hands of marauding Turkmen tribesmen who were unable to establish a government of any kind. Ravaged by conquest, Iraq fell into lawlessness and became close to uninhabitable. Roads became dangerous and irrigation systems collapsed, seeing precious farmland in the delta region sink below water. Rapacious Bedouin filled the vacuum, rendering the caravan trade all but impossible. Denied authority of any kind and severed from its historic trading ties with the Middle East and the Far East, the ancient city of Baghdad had become a minor town. The cumulative effect of the Mongol rampage and the social collapse that followed was that of the pre-existing Jewish community of Baghdad either died or fled. Jewish life entered a Dark Age. According to historian Zvi Yehuda, the fifteenth century sees no reports on Jews in Baghdad or in its surroundings, in Basra, Hilla, Kifil, ‘Ana, Kurdistan, even in Persia and the Persian Gulf. The organized Jewish community of Iraq appears to have disappeared in this period for more than four generations. This is behind the discontinuity between the present traditions of Iraqi Jewry and the Babylonian traditions of Talmudic or Geonic times. It remains the case that most Jewish Iraqis are of indigenous Middle Eastern ancestry rather than migrants from Spain, as in the case of parts of North Africa and the Levant. Ottoman rule: 1534–1917 During Ottoman rule (1534–1917) Jewish life prospered in Iraq. Jews were afforded religious liberties, enabling them to administer their own affairs in Jewish education. Tolerance towards Jews and Jewish customs, however, depended on local rulers. Ottoman ruler Sultan Murad IV appointed 10,000 Jewish officers in his government, as he valued the Baghdadi Jews. In contrast, Murad's governor Dauod Pasha was cruel and was responsible for the emigration of many Iraqi Jews. After Dauod's death in 1851, Jewish involvement in commerce and politics increased, with religious influence also transforming. The Iraqi Jewish community introduced the Hakham Bashi, or Chief Rabbinate, in 1849, with Hakham Ezra Dangoor leading the community. The chief rabbi was also president of the community and was assisted by a lay council, a religious court, and a schools committee. After various changes of fortune, Mesopotamia and Iraq came into the hands of the Ottoman Turks, when Sultan Suleiman the Magnificent in 1534 took Tabriz and Baghdad from the Persians, leading to an improvement in the life of the Jews. The Persian reconquest in 1623 during the Ottoman–Safavid War (1623–1639) led to a much worse situation, so that the re-conquest of Iraq by the Turks in 1638 included an army with a large population of Jews. Some sources say they made up 10% of the army. The day of the reconquest was even given a holiday, "Yom Nes" (day of miracle). This period of Mameluk rule in Iraq, under the aegis of the Ottoman Empire, united most of the future territory of Iraq into a single unit for the first time. As it ceased to be a warring frontier, opportunities for trade increased, especially due to the growing European presence on the ocean routes to India. Following this uptick in trade and security, Jewish communities began to be reestablished in Baghdad and Basra. This was not the revival of a community so much as the establishment of a new one. According to the historian Zvi Yehuda, an analysis of the tens of thousands of Iraqi Jewish family trees stored at the Babylonian Jewry Heritage Center have indicate that families of Baghdadi Jews do not possess family trees tracing their lineage prior to the end of the 17th century. They were migrants from smaller Mesopotamian communities and from across the Middle East. Yehuda calls the Jewish community that reestablished itself in Baghdad, Basra and other cities the "new Babylonian Diaspora". In 1743, there was a plague in which many of the Jews of Baghdad, including all the rabbis, died. The remaining Baghdad community asked the community of Aleppo to send them a new Chief Rabbi, leading to the appointment of Rabbi Sadka Bekhor Hussein. Culturally, it would prove a decisive moment when Chief Rabbi Shmuel Laniyado of Aleppo picked his protege for Baghdad. It is said he was accompanied by fifty Sephardic Jewish families from Aleppo. Many of them were Rabbis who were to sit on the Beth Din of Baghdad and Basra. This led to an assimilation of Iraqi Judaism to the general Sephardic mode of observance. Jewish culture revived, with communal leaders as Solomon Ma’tuk being renown for his work as an astronomer, library and piyyutim. This brought the leading Jewish families of Baghdad, and with it, their Jewish practice into the network of Sephardic scribes and later printing presses established in Aleppo, Livorno and Salonica. Surviving records of the contents of the library of Solomon Ma’tuk shows a great number of books purchased from Sephardic scribes and some even originally from Spain. Further driving this process was the high esteem in which Rabbi Sadka Bekhor Hussein was held as a halakhic authority. This saw him accepted as a halakhic authority by the Jews of Persia, Kurdistan and the fledgling Baghdadi trading outposts being established in India. Sephardic Rabbis and their rulings and practices were held in higher esteem. The historian Zvi Yehuda says the period saw the wheels turn in the relationship between the Babylonian Jewish communities and those of Iraq and Persia: "Before the 18th century, the Baghdadi Community needed the support of those communities; now the Baghdadi Community influenced them." The 18th century saw the Jewish community of Aleppo exert a significant influence over the Jewish communities of Baghdad and Basra not only culturally but economically. Syrian Jewish families establishing themselves in Iraq were often formerly Spanish Sephardic families from Aleppo. These were typically high-class families such as the Belilios family who were frustrated with the dimming prospects of Aleppo and attracted to Baghdad and Basra's booming trade with India. This process saw the leading Jewish families of Baghdad, Basra and Aleppo grow to be heavily interlinked through marriages, religious life, partnership and trade in the 18th century. As this process of cultural assimilation saw the Jews of Baghdad come to more closely resemble the Jews of Aleppo, economic decline in Syria, Kurdistan and Persia worsened. The 18th century saw a growing number of Jews leave from there to Baghdad, Basra or the Baghdadi-led outposts being established in the Far East. The still small and reemerging Jewish community of Baghdad became a migration destination with Jewish families settling in Baghdad from Istanbul, Aleppo, Damascus, Ana and Basra. A key driver of this was decline of the old caravan route running between these cities. There was also migration from the communities of Palestine, the villages of Kurdistan, and it is said that a handful of Jews settled in Baghdad from Germany. By the early 19th century, Baghdad had been reestablished as a leading Jewish center in the Middle East. There were over 6,000 Jews in city, two synagogues and strong community institutions. This was not a golden age, however. Over time, the centralized Ottoman control over the region deteriorated and the situation of the Jews worsened, but the population continued to grow very rapidly. An example of this deterioration is the persecution of Dawud Pasha, which began in 1814 and lasted until 1831. Many leaders of the Jewish community, such as Solomon Ma’tuk, were forced to flee. One of the foremost leaders of the community, David Sassoon, was forced to flee first to Busher and then to India.[citation needed] By the early 19th century, trade between Baghdad and India was said to be entirely in the hands of the Jewish community. Though Jewish traders from the Middle East had been crossing the Indian Ocean since antiquity, the deteriorating situation in the Ottoman Empire and the rise of commercial opportunities in British India saw many Jews from Iraq establish themselves permanently in India, at first in Surat, then especially in Calcutta and Bombay. This was the beginning of primarily Iraqi Jewish diaspora in Asia known as the Baghdadi Jews, to which David Sassoon and many of the other leading Jewish families in Baghdad fled the persecution of Dawud Pasha. These Judeo-Arabic speaking communities, following mostly Iraqi Jewish customs, would be formed along the so-called opium route between India and China, including in Singapore, Hong Kong and Shanghai. These were all led by leading Iraqi Jewish families such as the Sassoons, Ezras, Eliases, Gubbays and Judahs. These families were active sponsors of religious life and charity back in Iraq. Israel Joseph Benjamin, the Ashkenazi Jewish traveller and scholar from Moldova, who conducted extensive journeys to visit even the most furthest flung Sephardic and Mizrahi Jewish communities of Asia between 1845 and 1859, wrote of Baghdad that "in no other place in the east have I found my Israelitish brothers in such perfectly happy circumstances." One distinguishing feature of the communities of Baghdad and Basra remarked upon by Ashkenazi travelers was the extreme young age of marriage: between eight and twelve years old for girls to men usually eighteen to twenty. Another was the traditional face veils and long flowing garments wore by Jewish women who were not expected to show their face in public like their Muslim neighbors. During the 19th century, the influence of the Jewish families of Aleppo of the previous century faded as Baghdad emerged as a strong Jewish and economic center in its own right. The Jewish population has grown so rapidly that by 1884, there were 30,000 Jews in Baghdad and by 1900, 50,000, comprising over a quarter of the city's total population. Large-scale Jewish immigration from Kurdistan to Baghdad continued throughout this period. By the mid-19th century, the religious infrastructure of Baghdad grew to include a large yeshiva which trained up to sixty rabbis at time. Religious scholarship flourished in Baghdad, which produced great rabbis, such as Joseph Hayyim ben Eliahu Mazal-Tov, known as the Ben Ish Chai (1834–1909) or Rabbi Abdallah Somekh (1813–1889). Modern Iraq About 200,000 Jews lived in Iraq, in 1948 and 200,000 Jews in Kurdistan region of Northern Iraq. Early Labor Zionism mostly concentrated on the Jews of Europe, skipping Iraqi Jews because of their lack of interest in agriculture. The result was that "Until World War II, Zionism made little headway because few Iraqi Jews were interested in the socialist ideal of manual labor in Palestine." However, across the Baghdadi Jewish Diaspora many prominent families in Asia such as such as the Meyers of Singapore strongly supported Zionism. These families, such as branches of the Sassoons, retained strong religious and familial ties to Baghdad into the early 20th century. By the 1930s there were over 7,000 Baghdadi Jews across Asia, mostly in India. During the British Mandate, beginning in 1920, and in the early days after independence in 1932, well-educated Jews played an important role in civic life. They were important in developing the judicial and postal systems. Iraq's first minister of finance, Sassoon Eskell, was a Jew. Records from the Baghdad Chamber of Commerce show that 10 out of its 19 members in 1947 were Jews and the first musical band formed for Baghdad's nascent radio in the 1930s consisted mainly of Jews. Jews were represented in the Iraqi parliament, and held significant positions in the bureaucracy. and the government Between 1924 and 1928, some Jews fled persecution in Russia, arriving in Iraq as refugees. In Baghdad's markets, they were prominent jewelers, smiths, and cloth dealers. In Basra, many Jews worked at the important port authority. They introduced foreign brands to Iraq, such as Chevrolet and Ford Motor. The Jews established factories for the manufacture of soap, woolen textiles, cigarettes, gold and silver crafting, printing, and others. Organized Zionist activity began in Iraq in the 1920s. The Jewish population was generally sympathetic toward the movement, although not at that time as a solution for Iraqi Jews. The Zionist organization in Baghdad was initially granted a permit by the British, in March 1921, but in the following year, under the government of King Faisal I, was unable to renew it. Nevertheless, its activities were tolerated until 1929. In that year, after conflict and bloodshed in Palestine during anti-Zionist demonstrations and riots, Zionist activities were banned and teachers from Palestine, who had taught Hebrew and Jewish history, were forced to leave. In the 1930s, the situation of the Jews in Iraq deteriorated. Previously, the growing Iraqi Arab nationalist sentiment included Iraqi Jews as fellow Arabs, but these views changed with the ongoing conflict in the Palestinian Mandate and the introduction of Nazi propaganda. Despite protestations of their loyalty to Iraq, Iraqi Jews were increasingly subject to discrimination and anti-Jewish actions. In September 1934, following the appointment of Arshad al-Umari as the new minister of economics and communications, tens of Jews were dismissed from their posts in that ministry; and, subsequently, there were unofficial quotas of Jews that could be appointed in the civil service or admitted to secondary schools and colleges. Zionist activity had continued covertly even after 1929, but in 1935 the last two Palestinian Jewish teachers were deported, and the president of the Zionist organization was put on trial and ultimately required to leave the country. Following the collapse of Rashid Ali al-Gaylani's pro-Axis coup d'état in 1941, the Farhud ("violent dispossession") pogrom broke out in Baghdad on June 1, in which approximately 200 Iraqi Jews were murdered (some sources put the number higher), and up to 2,000 injured – damages to Jewish-owned property were estimated at $3 million (US$ 66 million in 2025). There were also instances of looting of Jewish properties in many other cities at around the same time, with the pogrom lasting for two days until June 2. Afterwards, Jewish emissaries from Palestine were sent to teach Iraqi Jews self-defense, which they were eager to learn. The newly restored pro-Allied monarchist regime quickly implemented measures to prevent the outbreak of similar anti-Jewish violence and established a committee of enquiry on June 7 "to examine the facts and find who was culpable." Before the United Nations Partition Plan for Palestine vote, Iraq's prime minister Nuri al-Said informed British diplomat Douglas Busk "that he had nothing against Iraqi Jews who were a long established and useful community. He felt bound to tell me, however, that the Arab League meeting might decide that if a satisfactory solution of the Palestine case was not reached severe measures should be taken against all Jews in Arab countries. He would be unable to resist such a proposal." In a speech at the United Nations General Assembly Hall at Flushing Meadow, New York, on Friday, November 28, 1947, Iraq's Foreign Minister, Muhammad Fadhel al-Jamali, included the following statement: Partition imposed against the will of the majority of the people will jeopardize peace and harmony in the Middle East. Not only the uprising of the Arabs of Palestine is to be expected, but the masses in the Arab world cannot be restrained. The Arab-Jewish relationship in the Arab world will greatly deteriorate. There are more Jews in the Arab world outside of Palestine than there are in Palestine. In Iraq alone, we have about one hundred and fifty thousand Jews who share with Muslims and Christians all the advantages of political and economic rights. Harmony prevails among Muslims, Christians and Jews. But any injustice imposed upon the Arabs of Palestine will disturb the harmony among Jews and non-Jews in Iraq; it will breed inter-religious prejudice and hatred. In the months leading up to the November 1947 Partition vote, violence against Iraqi Jews increased. In May 1947, a Jewish man in Baghdad was lynched by an angry mob after being accused of giving poisoned candy to Arab children. Rioters ransacked homes in the Jewish Quarter of Fallujah, and the Jewish population there fled to Baghdad. Large Jewish "donations" for the Palestinian Arab cause were regularly extorted, with the names of "donors" read out on the radio to encourage more. In spite of this, Iraqi Jews still mostly continued to view themselves as loyal Iraqis and believed that the hardship would pass. The Jewish Agency's emissary to Iraq reported that "No attention is paid [by the Jews] to the frightful manifestations of hostility around them, which place all Jews on the verge of a volcano about to erupt." In 1948, the year of Israel's independence, there were about 150,000 Jews in Iraq. Persecution of Jews greatly increased that year. In July 1948, the government passed a law making Zionism a capital offense, with a minimum sentence of seven years imprisonment. Any Jew could be convicted of Zionism-based only on the sworn testimony of two Muslim witnesses, with virtually no avenue of appeal available. On August 28, 1948, Jews were forbidden to engage in banking or foreign currency transactions. In September 1948, Jews were dismissed from the railways, the post office, the telegraph department, and the Finance Ministry on the ground that they were suspected of "sabotage and treason". On October 8, 1948, the issuance of export and import licenses to Jewish merchants was forbidden. On October 19, 1948, the discharge of all Jewish officials and workers from all governmental departments was ordered. In October, the Egyptian paper El-Ahram estimated that as a result of arrests, trials, and sequestration of property, the Iraqi treasury collected some 20 million dinars or the equivalent of 80 million U.S. dollars. On December 2, 1948, the Iraq government suggested to oil companies operating in Iraq that no Jewish employees be accepted. "With very few exceptions, only Jews wore watches. On spotting one that looked expensive, a policeman had approached the owner as if to ask the hour. Once assured the man was Jewish, he relieved him of the timepiece and took him into custody. The watch, he told the judge, contained tiny wireless; he'd caught the Jew, he claimed, sending military secrets to the Zionists in Palestine. Without examining the "evidence" or asking any questions, the judge pronounced his sentence. The "traitor" went to prison, the watch to the policeman as a reward."[clarification needed] Following the Israeli Declaration of Independence and Iraq's subsequent participation in the 1948 Arab–Israeli War, Iraq was placed under martial law. Courts martial were used to intimidate wealthy Jews, Jews were again dismissed from civil service, quotas were placed on university positions, and Jewish businesses were boycotted. In sweeps throughout urban areas, the Iraqi authorities searched thousands of Jewish homes for secret caches of money they were presumed to be sending to Israel. Walls were frequently demolished in these searches. Hundreds of Jews were arrested on suspicion of Zionist activity, tortured into confessing, and subjected to heavy fines and lengthy prison sentences. In one case, a Jewish man was sentenced to five years' hard labor for possessing a Biblical Hebrew inscription which was presumed to be a coded Zionist message. The greatest shock to the Jewish community came with the arrest and execution of businessman Shafiq Ades, a Jewish automobile importer who was the single wealthiest Jew in the country. Ades, who had displayed no interest in Zionism, was arrested on charges of sending military equipment to Israel and convicted by a military tribunal. He was fined $20 million and sentenced to death. His entire estate was liquidated and he was publicly hanged in Basra in September 1948. The Jewish community's general sentiment was that if an assimilated and non-Zionist Jew as powerful and well-connected as Ades could be eliminated, other Jews would not be protected any longer. Additionally, like most Arab League states, Iraq forbade any legal emigration of its Jews on the grounds that they might go to Israel and could strengthen that state. At the same time, increasing government oppression of the Jews fueled by anti-Israeli sentiment together with public expressions of antisemitism created an atmosphere of fear and uncertainty. The Iraqi Jewish community gradually became impoverished because of persecution. Jewish businesses were forced to close in the face of boycotts and arrests of Jewish businessmen. After Jews were prohibited from working in the civil service, skilled and formerly well-paid Jewish civil service employees were driven into poverty and forced to become street peddlers to avoid being arrested for vagrancy. Jewish home values dropped by 80%. On February 19, 1949, Nuri al-Said acknowledged the bad treatment that the Jews had been victims of in Iraq during the recent months. He warned that unless Israel behaved itself, events might take place concerning the Iraqi Jews. With Iraqi Jews enduring oppression and being driven into destitution, the Iraqi Zionist underground began smuggling Jews out of Iraq to Israel starting in November 1948. Jews were smuggled into Iran and from there proceeded to Israel. By 1949, the Iraqi Zionist underground had become well-established (despite many arrests), and they were smuggling Iraqi Jews out of the country illegally at a rate of 1,000 a month. The fleeing Jews took money and some possessions with them, and this capital flight harmed the Iraqi economy. Hoping to stem the flow of assets from the country, in March 1950 Iraq passed a law of one-year duration allowing Jews to emigrate on condition of relinquishing their Iraqi citizenship. They were motivated, according to Ian Black, by "economic considerations, chief of which was that almost all the property of departing Jews reverted to the state treasury" and also that "Jews were seen as a restive and potentially troublesome minority that the country was best rid of." Iraqi politicians candidly admitted that they wanted to expel their Jewish population for reasons of their own. Israel was initially reluctant to absorb so many immigrants, but mounted an airlift in March 1951 called "Operation Ezra and Nehemiah" to bring as many of the Iraqi Jews as possible to Israel, and sent agents to Iraq to urge the Jews to register for immigration as soon as possible. Iraqi Jews mainly left Iraq for Cyprus and Iran, from where they were airlifted to Israel, though for a time direct flights between Israel and Baghdad were allowed. From the start of the emigration law in March 1950 until the end of the year, 60,000 Jews registered to leave Iraq. In addition to continuing arrests and the dismissal of Jews from their jobs, this exodus was encouraged by a series of bombings starting in April 1950 that resulted in a number of injuries and a few deaths. Two months before the expiration of the law, by which time about 85,000 Jews had registered, another bomb at the Masuda Shemtov synagogue killed 3 or 5 Jews and injured many others. Iraqi Prime Minister Nuri al-Said was determined to drive the Jews out of his country as quickly as possible, and on August 21, 1950, he threatened to revoke the license of the company transporting the Jewish exodus if it did not fulfill its daily quota of 500 Jews. The available planes initially did not match the demand, and as a result many Jews had to wait for extended periods of time in Iraq while awaiting transport to Israel. These Jews, having already been denaturalized and renounced all property, were now stateless and destitute, and many were now homeless and sleeping on the streets. The Iraqi government announced that if the Jews were not removed more swiftly, they would be placed in concentration camps. As a result, more airlines were chartered to speed up the exodus. On September 18, 1950, Nuri al-Said summoned a representative of the Jewish community and claimed Israel was behind the emigration delay, threatening to "take them to the borders" and forcibly expel the Jews. The law expired in March 1951 but was later extended after the Iraqi government froze the assets of departing Jews, including those who had already left. During the next few months, all but a few thousand of the remaining Jews registered for emigration, spurred on by a sequence of further bombings that caused few casualties but had great psychological impact. Israel's fragile infrastructure, which already had to accommodate a mass influx of Jewish immigration from war-ravaged Europe and other Arab and Muslim countries, was heavily strained, and the Israeli government was not certain that it had enough permanent housing units and tents to accommodate the Iraqi Jews. When Israel attempted to negotiate a more gradual influx of Iraqi Jews, Said realized that the Jews could be turned into a demographic weapon against Israel. He hoped that a rapid influx of totally penniless Jews would collapse Israel's infrastructure. In March 1951, he engineered a law which would permanently freeze all assets of denaturalized Jews. Officially, the assets were merely frozen and not confiscated; under international law assets can theoretically remain frozen for perpetuity, making it impossible for them to ever be reclaimed. The law was prepared in secret, as it was being ratified, Baghdad's telephone network suspended operations to prevent Jews from learning of it and attempt to transfer or withdraw their money. Iraq's Banks were closed for three days to ensure that Jews could not access their funds. With Iraq's Jews effectively stripped of their assets permanently, Said demanded Israel accept 10,000 Iraqi Jewish refugees per month. He threatened to prohibit Jewish emigration from May 31, 1951, and to set up concentration camps for stateless Jews still in Iraq. Israel attempted to negotiate a compromise to enable the Iraqi Jews to leave gradually in a way that did not put as much pressure on Israel's absorptive capacity, but Said was adamant that the Jews had to leave as fast as possible. As a result, Israel increased the flights. In Baghdad, the daily spectacle of Jews carrying nothing but their clothes and a bag of their remaining possessions being loaded onto trucks for transport to the airport caused public jubilation. Jews were mocked every step of the way during their departure and crowds stoned the trucks taking Jews to the airport. Jews were allowed to bring out a maximum of five pounds weight in property, which was to consist of personal effects only, as well as a small amount of cash. At the airport, Iraqi officials body searched every emigrant for cash or jewelry, and they also beat and spat on the departing Jews. Overall, between 1948 and 1951, 121,633 Iraqi Jews were airlifted, bused, or smuggled out of the country, including 119,788 between January 1950 and December 1951. About 15,000 Jews remained in Iraq. In 1952, emigration to Israel was again banned, and the Iraqi government publicly hanged two Jews who had been falsely charged with throwing a bomb at the Baghdad office of the U.S. Information Agency. According to Palestinian politician Aref al-Aref, Said had attempted to justify allowing the exodus by explaining to him that: "The Jews have always been a source of evil and harm to Iraq. They are spies. They have sold their property in Iraq, they have no land among us that they can cultivate. How therefore can they live? What will they do if they stay in Iraq? No, no my friend, it is better for us to be rid of them as long as we are able to do so." Iraqi Jews left behind them extensive property, often located in the heart of Iraq's major cities. A relatively high number found themselves in refugee camps in Israel known as Ma'abarot before being given permanent housing. The agents behind the 1950-1951 Baghdad bombings are a subject of controversy. A secret Israeli inquiry in 1960 found no evidence that they were ordered by Israel or any motive that would have explained the attack, though it did find out that most of the witnesses believed that Jews had been responsible for the bombings. The issue remains unresolved: Iraqi activists still regularly charge that Israel used violence to engineer the exodus, while Israeli officials of the time vehemently deny it. Historian Moshe Gat reports that "the belief that the bombs had been thrown by Zionist agents was shared by those Iraqi Jews who had just reached Israel". Sociologist Phillip Mendes backs Gat's claims, and further attributes the allegations to have been influenced and distorted by feelings of discrimination. The affair has also been the subject of a libel lawsuit by Mordechai Ben Porat, which was settled in an out-of-court compromise with an apology of the journalist who described the charges as true. Iraqi authorities eventually charged three members of the Zionist underground with perpetrating some of the explosions. Two of those charged, Shalom Salah Shalom and Yosef Ibrahim Basri, were subsequently found guilty and executed, while the third was sentenced to a lengthy jail term. Salah Shalom claimed in his trial that he was tortured into confessing, and Yosef Basri maintained his innocence throughout. Gat reports that much of the previous literature "reflects the universal conviction that the bombings had a tremendous impact on the large-scale exodus of the Jews... To be more precise it is suggested that the Zionist emissaries committed these brutal acts in order to uproot the prosperous Iraqi Jewish community and bring it to Israel". However, Gat argues that both claims are contrary to the evidence. As summarized by Mendes: Historian Moshe Gat argues that there was little direct connection between the bombings and exodus. He demonstrates that the frantic and massive Jewish registration for denaturalization and departure was driven by knowledge that the denaturalisation law was due to expire in March 1951. He also notes the influence of further pressures including the property-freezing law, and continued anti-Jewish disturbances which raised the fear of large-scale pogroms. In addition, it is highly unlikely the Israelis would have taken such measures to accelerate the Jewish evacuation given that they were already struggling to cope with the existing level of Jewish immigration. Gat also raises serious doubts about the guilt of the alleged Jewish bombthrowers. Firstly, a Christian officer in the Iraqi army known for his anti-Jewish views, was arrested, but apparently not charged, with the offences. A number of explosive devices similar to those used in the attack on the Jewish synagogue were found in his home. In addition, there was a long history of anti-Jewish bomb-throwing incidents in Iraq. Secondly, the prosecution was not able to produce even one eyewitness who had seen the bombs thrown. Thirdly, the Jewish defendant Shalom Salah indicated in court that he had been severely tortured in order to procure a confession. It therefore remains an open question as to who was responsible for the bombings, although Gat argues that the most likely perpetrators were members of the anti-Jewish Istiqlal Party. Certainly memories and interpretations of the events have further been influenced and distorted by the unfortunate discrimination which many Iraqi Jews experienced on their arrival in Israel. Many years later, the widow of the Zionist emissary Yehuda Tager stated that while the main bombings were carried out by the Muslim Brotherhood, later smaller attacks were staged by Yosef Beit-Halahmi, on his own initiative, in an attempt to make it seem as if the activists on trial were not the perpetrators. In Three Worlds: Memoirs of an Arab-Jew, Avi Shlaim unveils what he argues is "undeniable proof of Zionist involvement in the terrorist attacks" which prompted a mass exodus of Jews from Iraq between 1950 and 1951. The historian based his conclusion that most of the bombings against Jews in Iraq were the work of Mossad on two pieces of evidence: one draws on the recollections given to Shlaim by an elderly former member of the Zionist undergroundi. The other is a contempèorary Baghdad police report on the incident, which contains Basri's confession. He believed these actions were intended to quicken the transfer of 110,000 Jews in Iraq to the then-newly created state of Israel. Republic of Iraq In the 14 July Revolution, the Hashemite monarchy were overthrown and numerous members of the royal family were killed brutally, creating a fear among the Iraqis. During the coup, Jews were subjected to violence. The Jews had their telephones cut off, Jewish government officials were fired and their homes were raided by the mobs. Most of the 15,000 Jews remained after Operation Ezra and Nehemiah. They stayed throughout the new Republic of Iraq. Conditions were improved and began to return normal during the era of Abdul-Karim Qasim, who took power in 1958. Qasim lifted restrictions on Jews. They were re-integrated into society. The Grand Rabbi pledged Qasim to protect the Jews, who fulfilled his promises. Nevertheless, antisemitism increased during the rule of the Arif brothers (Abdul Salam Arif and Abdul Rahman Arif).[citation needed] With the rise of the Ba'ath Party to power in 1963, restrictions were placed on the remaining Iraqi Jews. Sale of property was banned, and Jews had to carry yellow identity cards.[citation needed] After the 1967 Six-Day War, Jewish property was expropriated, bank accounts were frozen, Jews were dismissed from public posts, their businesses were closed, trading permits owned by Jews were cancelled, they were not allowed to use telephones, they were placed under house arrest for extended periods of time, and were under constant surveillance and restricted to the cities.[citation needed] Ba'athist Iraq In late 1968, scores of Jews were jailed on charges of spying for Israel, culminating in the 1969 public hanging of 14 men, 9 of them Jews, who were accused of spying for Israel. Other suspected spies for Israel died under torture. After Baghdad Radio invited Iraqi citizens to "come and enjoy the feast", half a million people paraded and danced past the scaffolds where the men were hanged, which resulted in international criticism. A Jew who later left wrote that the stress of persecution caused ulcers, heart attacks, and breakdowns to become increasingly prevalent in the Jewish community. A further 18 Jews were hanged in secret from 1970 to 1972, and in April 1973 five members of a single Jewish family were killed on the orders of the head of the Iraqi secret police in retaliation for an Israeli assassination of a Palestinian leader. Repressive policies were enforced again. Passports were taken away and travel was restricted. As a result, Jews escaped the country by traveling to Iraqi Kurdistan and then slipping into Iran with the help of Kurdish smugglers. From there many emigrated to Israel while some also moved to other countries such as the United Kingdom and Australia. In the early 1970s, bowing to international pressure and having concluded that its emigration ban was useless, the government allowed Jewish emigration and most of the remaining Jews left.[A 1] The majority of those who stayed behind were elderly, and the community was subsequently pressured by the government to turn over $200 million worth of Jewish community property without compensation.[A 2][A 3] After the kidnappings, executions, and arrests ceased, the government sought to improve its image in regard with Jews. Aside from few incidents, situation became normal. In 1969, a booklet titled "Iraqi Jews Speak for Themselves," was published featuring interviews with prominent Jews like Sasson Khedouri, Anwar Shaul, Mir Basri, Salman Darwish and others on the state-owned newspaper The Baghdad Observer. Many seen rejecting Zionism, emphasizing their ancestral ties to Mesopotamia, claiming a 2,500-year history and a connection to the birthplace of their patriarch, Abraham, in Ur. They identified as both Iraqi citizens and part of the Arab lineage, citing numerous shrines to Jewish prophets and saints in Iraq. The publication was seen as propaganda by many observers. According to testimonies given by the majority of Jewish people living in Iraq that time, this was less harsh than the treatment of Jews by previous regimes. According to Mahmoud Abbas the president of the Palestinian authority, in 1975 the government invited exiled Iraqi Jews to live in Iraq. However, it attracted only a few families. He claims the decree was criticized by Israel, and eventually failed. A few families who returned to Iraq were given government jobs and even appeared on interviews, criticising Israel. The whereabouts of the families remained unknown, and those who returned later went back to Israel for unknown reasons, where they were subsequently arrested by the Israeli authorities. In 1977, Iraq approved calls for repartation of Arab Jews to their countries of origin by Palestinian leader Mahmoud Abbas. Anwar Shaul, a Jewish professor and lawyer, was invited twice to appear in literary seminars on Iraqi television, and President Ahmed Hassan al-Bakr sent him a bouquet of flowers when he entered a hospital for treatment. Mir Basri, a prominent writer and poet, served as acting leader of the Jewish community. He attended the Arab Writers Conference in 1969 at Baghdad and represented Iraq. Basri's presentation was well received. Sasssoon Khadouri congratulated al-Bakr on his presidency. Upon the death of Khadouri in 1971, the Baghdad Observer declared him with the title "Iraqi Patriot". He received a state funeral, which was attended by numerous political figures, such as the president and minister. His clothes were displayed in the National Museum of Iraq, Baghdad by Saddam Hussein, as a sign of respect. The situation improved when Saddam Hussein came to power. At that time around 15,000 Jews remained. He provided protection, allowed religious practice, offered subsidies, and assigned guards to protect synagogues. Only a few synagogues continued to function in Iraq, "a crumbling buildings tucked away in an alleyway" in Bataween, once Baghdad's main upscale Jewish neighborhood. Saddam helped in restoration of Meir Taweig Synagogue and construction Al-Habibiyah Jewish Cemetery. The Jews were allowed to visit and practice their rituals at religious sites revered by Muslims and Christians, such as Ezekiel's Tomb, Ezra's Tomb, Prophet Nahum Shrine, Tomb of Rabbi Joshua and Tomb of Daniel, all of which were preserved. The Administrative Committee was attached to the Ministry of Religious Endowments (Awqaf). Under the orders of Saddam, a Jewish representative was appointed by the government, who was Naji Salman Salih. The Jews had their old businesses back, mainly in the Import and export trade and factories, and held respectable jobs and civil servants. Jewish merchants and traders were active in Shorja and Daniel Market and had their own cultural center in Baghdad. Some of the well-known doctors, officers and engineers in government, public universities and government hospitals were Jews, such as Shaul Sassoon, Eliyahu Basra, and Jack Abboud Shabi. Ibrahim Hesqel, a Jewish chemist was sent by the government on a trade mission to China in 1988. Few notable figures remained such as Salima Pasha and Sultana Yossef. Other popular Jewish figures included writer and poet Maliha Ishaq and singer and dancer Laila. A committee was formed in 1973 by the Revolutionary Command Council, to oversee the endowed properties of Ezra Menachem Daniel located in Baghdad. They were tasked with managing these properties and allocating the revenues according to the endower's directives, focusing on supporting the poor and establishing various charitable, health, cultural, and vocational institutions. Incomes from former synagogues and hospitals supported charitable causes. During the 1980s, the United States pressured Saddam to adopt further measures to protect Jews. A department within the Ministry of National Security was set up to ensure their safety. During the Iran–Iraq War, Iran targeted areas near Jews in Baghdad with rockets and prompted Jews from Basra to relocate to Baghdad. After the war, some returned, while others moved abroad, occasionally visiting Iraq for family or financial reasons. Immediately prior to the Gulf War, the United States Department of State noted that there was no recent evidence of overt persecution of Jews. That said, international travel, particularly to Israel, was restricted, as was contact with Jewish groups abroad. In 1997, the Jerusalem Post reported that in the previous five years, some 75 Jews had fled Iraq, of whom about 20 moved to Israel and the rest mostly went to the United Kingdom and Netherlands. During Rosh Hashanah, a UN official visiting Baghdad filmed the Rosh Hashanah service at the synagogue. The only Ordained Rabbi died in 1996, and last kosher slaughterer (Shochet), emigrated in 2002. At this point, 500 to 1,000 Jews remained. In 2003, Emad Levy emerged as the leader of the Jewish community of Iraq. He functioned as the country's sole rabbi, kosher slaughterer, and advisor regarding Jewish issues. According to the Jewish Virtual Library, the last Jewish wedding in Iraq took place in 1978; the last Brit Milah in 1984. In 1998, a Palestinian killed four people, including two Jews, at a community center, but the attacker was arrested and executed in 1999. This was the first time quick action was taken against crimes targeting Jews. Saddam ensured that the remaining Jews would not be harmed. He also said, "Anyone who hurts the Jews in Baghdad will pay a heavy price." In 2001, Saddam Hussein ordered security services to identify all Jews remaining in Iraq, along with those born Jewish who converted to Islam and Christianity. Their investigation identified 39 Jews, the majority of whom—36 individuals—resided in Baghdad. Possibly there are more Jews, but hidden or distanced from reports. The report also noted approximately 220 people who had been born Jewish but later converted to Islam, as well as three who had converted to Christianity. The government was particularly alarmed by around 140 of these converts living in Northern Iraq, an area that had functioned autonomously since the conclusion of the Gulf War in 1991. Concerns arose because some of these individuals were reportedly leaving Islam to return to Judaism, with some even traveling between Northern Iraq and Israel. According to Rabbi Emad Levy, "The lives of the Jews were good and the regime did not mess with us.". Jewish children had Muslim and Christian friends, relations with them were positive, and Jews lived alongside them as neighbors. Kosher food was available, with Jews having their own butchers. Ordinary life of Jews continued with a mix of caution, routine, and limited joy. They could go about their daily activities—work, socializing in private settings like swimming pools and reading books—without overt interference from the government. However, this "ordinary" life was far from carefree. Interactions with foreigners, particularly Israelis, were restricted. The government viewed foreigners with suspicion, and Levy avoided synagogues when foreigners visited, fearing they might be government agents. The years of sanctions, attacks and wars and conflict brought people of all religions and sects closer together. The Jews, like Christians and Muslims, became more religious. Post-Saddam period: 2003—present The last active synagogue closed a few weeks before the 2003 invasion of Iraq. The coalition forces bombed intelligence headquarters and founded Iraqi Jewish Archive. In the war's aftermath, the Jewish Agency attempted to locate all remaining Iraqi Jews and offer them the opportunity to emigrate to Israel. The agency identified 34 Jews in Baghdad, half of whom were over the age of 70. However, possibly there were more. While generally impoverished, some of the community members were middle class, such as two doctors. Ultimately, six Iraqi Jews chose to emigrate; among them was Ezra Levy, Emad Levy's father. After the Ba'ath Party fell, the process of establishing a new democratic government began. During deliberations over the Iraqi constitution, lawmakers debated whether Jews should be considered a minority group or left out of the constitution altogether. During the process, Israeli author Sami Michael was also invited to write the new constitution of Iraq. An official of Jewish Agency when visited Iraq in 2003, confirmed that Saddam made sure that the remaining Jews would not be harmed. In October 2006, Rabbi Emad Levy announced that he planned to move to Israel. He compared the Jewish experience in Iraq to "living in a prison," reporting that most Jews stayed in their homes "out of fear of kidnapping or execution" amid ongoing sectarian violence. Despite numerous death threats, Levy remained in Iraq for four more years. He moved to Israel in 2010, subsequently marrying and starting a family. Levy was the last Iraqi Jew to emigrate. Nonetheless, he stayed in contact with Iraq's remaining Jewish community. In a 2018 interview, he said that there were five Jews still in the country, with a woman serving as the community director. According to the Chaldaean News, around 100 Jews were living in Iraq between 2006 and 2007. Despite Jewish protests, the United States opted to transfer the Iraqi Jewish Archive to the Iraqi government instead of the Iraqi Jewish community. This archive was digitized and can be viewed online. In Al-Qosh, the Jewish prophet Nahum's tomb was being restored in 2020 thanks to a $1-million grant from the U.S. and local authorities, as well as private donations. In 2020, the synagogue beside Ezekiel's Tomb was converted into a mosque.[better source needed] On March 15, 2021, one of the last Jews in Iraq, Dr. Dhafer Fouad Eliyahu, died. As of 2021, 4 Jews are known to be living in Iraq. In November 2021, Israeli police recovered a Baghdad Torah scroll from an Arab village. In December 2021, Iraqi Jews received Hanukkah kits. On May 27, 2022, Iraq passed a law making contact with Israel a capital offense. There are numerous estimates for the number of Jews living in Iraq. Some sources reports that only handful of Jews remain in Iraq, [excessive citations] while other reports estimate that there are still 160 Jews left in Baghdad. Due to fear of persecution, they are reluctant to reveal the actual number of Jews. Around 300 Jews still live in Iraqi Kurdistan region. [citation needed] There are possibly more, but some Jewish families are afraid to publicly acknowledge their religion for fear of persecution and practice their faith in secret. Among the American forces stationed in Iraq, there were only three Jewish chaplains. In 2011, a leaked US embassy cable named eight Jews left in Baghdad, one of whom, Emhad Levy, emigrated to Israel. Andrew White, the Vicar of St. George's Church in Baghdad, urged the remaining Jews to flee.[better source needed] White also requested help saving the few Torah scrolls that remained in Iraq. After the end of the civil war, few Jews reportedly returned. According to local news reports, 400 Jews remained Iraq, out of them 160 live in Baghdad. As of 2025 the total of Jews living in Iraq number 3. The government of Iraq recognizes the following religious groups; Muslims (Shi'a and Sunni), Chaldeans (Assyrians, Assyrian Catholics, Syriac Orthodox, Syriac Catholics, Armenian Apostolic, Armenian Catholics, Roman Catholics, National Protestants, Anglicans, Evangelical Protestant Assyrians, Seventh-day Adventists, Coptic Orthodox), Yezidis, Sabean-Mandeans, and Jews. They are also recognized in Iraqi Kurdistan. On June 22, 2015, Abdul Azim Al-Ajman, the head of the Parliamentary Committee on Endowments and Religious Affairs, stated that Iraq is home to various religious and ethnic groups, including Jews. He emphasized that Jewish citizens in Iraq practice their rituals without external pressure. According to Alsumaria News, Al-Ajman confirmed that representatives of Iraqi Jews participated in meetings within the Iraqi Parliament during the drafting of the National Social Peace Document. These representatives contributed to the parliamentary discussions related to the document and expressed their views. Iraqi Jews continue to practice their religious rituals freely, and representatives from the community have attended parliamentary sessions in Iraq. — Abdul Azim Al-Ajman In 2004, the community elected three representatives. Positive changes in Iraq regarding Jews have been noticed. In 2013, Muqtada al-Sadr declared that he "welcomes any Jew who prefers Iraq to Israel" adding that, "there is no difference between Jews, Muslims or Christians when it comes to the sense of nationalism. Those who do not carry out their national duties are not Iraqis even if they are Shiite Muslims." After winning elections in 2018 Sadr made same declaration, welcoming Jews of Iraq, who were expelled. A poll by the popular Facebook page Al-Khuwwa al-Nathifa (‘The Clean Brotherhood,’ over 1.7 million followers) recently showed that 77% of 62,000 respondents were in favor of the return of Jewish Iraqis. A few suggested the return of Iraq's Jews in exchange for Palestinian refugees' right of return. A recent video was uploaded on the website of the Iraqi media outlet Yalla showing a Jewish man, dressed in black with sidelocks and a hat, walking through the streets of Basra holding a map and looking for the house his grandfather left in the 1950s. As he walks around, people help him in a friendly manner and even invite him into their homes. The message: “We have no problem with this Jew, as he is an Iraqi.” But the man is an actor, engaged to record the prevailing sentiment toward the Jews after al-Sadr's statement. On Facebook, within days, the video had been viewed over 220,000 times and shared 1,300 times with mostly positive reactions. However, currently there is no point of return, until Iraq recovers from the post-war effects. In June 2025 the descendents of Jews who owned land in Iraq upon which the Embassy of France building stands have sued France for not paying rent on the land since 1967 [the Ba’ath party came to power in Iraq and demanded that France pay rent directly to the Iraqi treasury. The building had been sequestered.] Iraqi Jews See also Notes References Bibliography Further reading Further viewing External links |
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[SOURCE: https://en.wikipedia.org/wiki/Wow!_signal] | [TOKENS: 3023] |
Contents Wow! signal The Wow! signal was a strong narrowband radio signal detected on August 15, 1977, by Ohio State University's Big Ear radio telescope in the United States, then used to support the search for extraterrestrial intelligence. The signal appeared to come from the direction of the constellation Sagittarius and bore expected hallmarks of extraterrestrial origin. Astronomer Jerry R. Ehman discovered the anomaly a few days later while reviewing the recorded data. On the computer printout, he circled the reading of the signal's intensity, "6EQUJ5", and wrote the comment "Wow!" beside it, leading to the event's widely used name. The entire signal sequence lasted for the full 72-second window during which Big Ear was able to observe it. Despite numerous follow-up searches and hypotheses (including brief consideration of reflections from space debris, interstellar scintillation, and comet hydrogen clouds), the signal has never recurred, and no explanation, terrestrial or otherwise, has been confirmed. While some researchers have suggested it could represent an extraterrestrial transmission, its single occurrence and lack of replication limit the strength of this interpretation. The Wow! signal has inspired targeted searches, scientific discussion about rare astrophysical phenomena, and references in popular culture. Background In a 1959 paper, Cornell University physicists Philip Morrison and Giuseppe Cocconi had speculated that any extraterrestrial civilization attempting to communicate via radio signals might do so using a frequency of 1420 megahertz (21-centimeter spectral line), which is naturally emitted by hydrogen, the most common element in the universe and therefore likely familiar to all technologically advanced civilizations. In 1973, after completing an extensive survey of extragalactic radio sources, Ohio State University assigned the now-defunct Ohio State University Radio Observatory (nicknamed "Big Ear") to the scientific search for extraterrestrial intelligence (SETI), in the longest-running program of this kind in history. The radio telescope was located near the Perkins Observatory on the campus of Ohio Wesleyan University in Delaware, Ohio. By 1977, Ehman was working at the SETI project as a volunteer; his job involved analyzing by hand large amounts of data processed by an IBM 1130 computer and recorded on line printer paper. While perusing data collected on August 15 at 22:16 EST (23:16 EDT local time, 03:16 UTC), he spotted a series of values of signal intensity and frequency that left him and his colleagues astonished. The event was later documented in technical detail by the observatory's director. Signal measurement The string 6EQUJ5, commonly misinterpreted as a message encoded in the radio signal, represents in fact the signal's intensity variation over time, expressed in the particular measuring system adopted for the experiment. The signal itself appeared to be an unmodulated continuous wave, although any modulation with a period of less than 10 seconds or longer than 72 seconds would not have been detectable. The signal intensity was measured as signal-to-noise ratio, with the noise (or baseline) averaged over the previous few minutes. The signal was sampled for 10 seconds and then processed by the computer, which took 2 seconds. The result for each frequency channel was output on the printout as a single alphanumeric character, representing the 10-second average intensity, minus the baseline, expressed as a dimensionless multiple of the signal's standard deviation. In this particular intensity scale, a space character denoted an intensity between 0 and 1, that is between baseline and one standard deviation above it. The numbers 1 to 9 denoted the correspondingly numbered intensities (from 1 to 9); intensities of 10 and above were indicated by a letter: "A" corresponded to intensities between 10 and 11, "B" to 11 to 12, and so on. The Wow! signal's highest measured value was "U" (an intensity between 30 and 31), which is thirty standard deviations above background noise. John Kraus, the director of the observatory, gave a value of 1420.3556 MHz in a 1994 summary written for Carl Sagan. However, Ehman in 1998 gave a value of 1420.4556±0.005 MHz. This is (50±5 kHz) above the hydrogen line value (with no red- or blue-shift) of 1420.4058 MHz. If due to blue-shift, it would correspond to the source moving about 10 km/s (6.2 mi/s) towards Earth. An explanation of the difference between Ehman's value and Kraus's can be found in Ehman's paper. The first local oscillator in the telescope's radio receiver was specified to a frequency value of 1450.4056 MHz. However, the university's purchasing department made a typographical error in the order form, instead obtaining an oscillator with frequency 1450.5056 MHz (i.e., 0.1 MHz higher than desired). The software used in the experiment was then written to adjust for this error. When Ehman computed the frequency of the Wow! signal, he took this error into account.[citation needed] The Wow! signal had a bandwidth of less than 10 kHz. It is considered narrowband emission in the sense that its fractional bandwidth was relatively small (~0.001%). However, the 10 kHz bandwidth is not small compared to the bandwidth of some astrophysical masers (~1 kHz) or to the frequency resolution of modern narrowband SETI searches (~1 Hz). The Big Ear telescope was equipped with a receiver capable of measuring fifty 10 kHz-wide channels. The output from each channel was represented in the computer printout as a column of alphanumeric intensity values. The Wow! signal is essentially confined to one column. At the time of the observation, the Big Ear radio telescope was only adjustable for altitude (or height above the horizon), and relied on the rotation of the Earth to scan across the sky. Given the speed of Earth's rotation and the spatial width of the telescope's observation window, the Big Ear could observe any given point for just 72 seconds. A continuous extraterrestrial signal, therefore, would be expected to register for exactly 72 seconds, and the recorded intensity of such signal would display a gradual increase for the first 36 seconds—peaking at the center of the observation window—and then a gradual decrease as the telescope moved away from it. All these characteristics are present in the Wow! signal. Celestial location The precise location in the sky where the signal apparently originated is uncertain due to the design of the Big Ear telescope, which featured two feed horns, each receiving a beam from slightly different directions, while following Earth's rotation. The Wow! signal was detected in one beam but not in the other, and the data was processed in such a way that it is impossible to determine which of the two horns received the signal. There are, therefore, two possible right ascension (RA) values for the location of the signal (expressed below in terms of the two main reference systems): In contrast, the declination was unambiguously determined to be as follows: The galactic coordinates for the positive horn are l=11.7°, b=−18.9°, and for the negative horn l=11.9°, b=−19.5°, both being therefore about 19° toward the southeast of the galactic plane, and about 24° or 25° east of the Galactic Center. The region of the sky in question lies northwest of the globular cluster M55, in the constellation Sagittarius, roughly 2.5 degrees south of the fifth-magnitude star group Chi Sagittarii, and about 3.5 degrees south of the plane of the ecliptic. The closest easily visible star is Tau Sagittarii. Initially, no nearby Sun-like stars were known to lie within the antenna coordinates, although in any direction the antenna pattern would encompass about six distant Sun-like stars as estimated in 2016. In 2022, a paper published in the International Journal of Astrobiology identified three likely Sun-like stars within the antenna-pointed coordinates. The better characterized star, 2MASS 19281982-2640123, is located 1,800 light years away, only 132 light years away from Maccone's estimation where an intelligent civilization is more likely to exist. The other two candidates, 2MASS 19252173-2713537 and 2MASS 19282229-2702492, were insufficiently characterized but still likely to be Sun-like stars. Also, 14 other catalogued stars at the antenna coordinates may still turn out to be similar to the Sun after more data becomes available. As a response to the discovery, Breakthrough Listen conducted the first targeted search for the Wow! Signal in its first collaboration between the Green Bank Telescope and the Allen Telescope Array of the SETI Institute. The observations were performed on May 21, 2022, lasting 1 hour from Greenbank, 35 minutes from ATA, and 9 minutes and 40 seconds simultaneously. No technosignature candidates were found. Hypotheses on the signal's origin Interstellar scintillation of a weaker continuous signal—similar in effect to atmospheric twinkling—could be an explanation, but that would not exclude the possibility of the signal being artificial in origin. The significantly more sensitive Very Large Array did not detect the signal, and the probability that a signal below the detection threshold of the Very Large Array could be detected by the Big Ear due to interstellar scintillation is low.[failed verification] Other hypotheses include a rotating lighthouse-like source, a signal sweeping in frequency, or a one-time burst. Ehman said in 1994: "We should have seen it again when we looked for it 50 times. Something suggests it was an Earth-sourced signal that simply got reflected off a piece of space debris." He later somewhat recanted his skepticism, after further research showed the unrealistic requirements that a space-borne reflector would need to have to produce the observed signal. The signal's frequency of 1420 MHz is also part of a protected spectrum: a frequency range reserved for astronomical research in which terrestrial transmissions are forbidden, although a 2010 study documented several instances of terrestrial sources either interfering from adjacent frequency bands or illegally transmitting within the spectrum. In a 1997 paper, Ehman resists "drawing vast conclusions from half-vast data"—acknowledging the possibility that the source may have been military or otherwise a product of Earth-bound sources. In a 2019 interview with John Michael Godier, Ehman stated: "I'm convinced that the Wow! signal certainly has the potential of being the first signal from extraterrestrial intelligence." METI president Douglas Vakoch told Die Welt that any putative SETI signal detections must be replicated for confirmation, and the lack of such replication for the Wow! signal means it has little credibility. In August 2024, the Planetary Habitability Laboratory published a preprint reporting observations made in 2020 at the Arecibo Observatory in Puerto Rico—where they conclude that the Wow! signal was likely caused by a rare astrophysical event, in which stellar emissions energizing a cold hydrogen cloud caused it to suddenly surge in brightness. In 2017, Antonio Paris, Assistant Professor of Astronomy and Astrophysics at St. Petersburg College, Florida, proposed that the hydrogen cloud surrounding two comets, 266P/Christensen and 335P/Gibbs, now known to have been in the same region of the sky, could have been the source of the Wow! signal. This hypothesis was dismissed by astronomers, including members of the original Big Ear research team, as the cited comets were not in the beam at the correct time. Furthermore, comets do not emit strongly at the frequencies involved, and there is no explanation for why a comet would be observed in one beam but not in the other. Searches for recurrence of the signal Several attempts were made by Ehman and other astronomers to recover and identify the signal. The signal was expected to occur three minutes apart in each of the telescope's feed horns, but that did not happen. Ehman unsuccessfully searched for recurrences using Big Ear in the months after the detection. In 1987 and 1989, Robert H. Gray searched for the event using the META array at Oak Ridge Observatory, but did not detect it.[page needed] In a July 1995 test of signal detection software to be used in its upcoming Project Argus, SETI League executive director H. Paul Shuch made several drift-scan observations of the Wow! signal's coordinates with a 12-meter radio telescope at the National Radio Astronomy Observatory in Green Bank, West Virginia, also achieving a null result. In 1995 and 1996, Gray again searched for the signal using the Very Large Array, which is significantly more sensitive than Big Ear.[page needed] Gray and Simon Ellingsen later searched for recurrences of the event in 1999 using the 26-meter radio telescope at the University of Tasmania's Mount Pleasant Radio Observatory. Six 14-hour observations were made at positions in the vicinity, but nothing like the Wow! signal was detected.[page needed] Response In 2012, on the 35th anniversary of the Wow! signal, the Arecibo Observatory was said to have beamed a digital stream towards Hipparcos 34511, 33277, and 43587. The transmission consisted of approximately 10,000 Twitter messages solicited for the purpose by the National Geographic Channel, bearing the hashtag "#ChasingUFOs" (a promotion for one of the channel's TV series). The sponsor also included a series of video vignettes featuring verbal messages from various celebrities. According to Robert Kerr, the former director of the Arecibo Observatory who oversaw the Wow! reply, the transmitter overheated shortly into the first transmission, and it was only sent in the direction of one of the targets. It is unknown how many tweets made it through. None of the targeted stars are within the possible region from which the Wow! signal came. To increase the probability that any extraterrestrial recipients would recognize the signal as an intentional communication from another intelligent life form, Arecibo scientists attached a repeating-sequence header to each individual message. In popular culture The signal was featured in the 2024 television series 3 Body Problem, in which the signal is also detected in Inner Mongolia. The signal was also referenced in the 1994 season 2 premier of The X-Files, "Little Green Men". See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Template:Elon_Musk] | [TOKENS: 276] |
Contents Template:Elon Musk This is a navigational template created using {{navbox}}. It can be transcluded on pages by placing {{Elon Musk}} below the standard article appendices and above categories. Initial visibility This template's initial visibility currently defaults to autocollapse, meaning that if there is another collapsible item on the page (a navbox, sidebar, or table with the collapsible attribute), it is hidden apart from its title bar; if not, it is fully visible. To change this template's initial visibility, the |state= parameter may be used: Templates using the classes class=navbox ({{navbox}}) or class=nomobile ({{sidebar}}) are not displayed in article space on the mobile web site of English Wikipedia. Mobile page views accounted for 60% to 70% of all page views from 2020 through 2025. Briefly, these templates are not included in articles because 1) they are not well designed for mobile, and 2) they significantly increase page sizes—bad for mobile downloads—in a way that is not useful for the mobile use case. You can review/watch phab:T124168 for further discussion. TemplateData A navigational box that can be placed at the bottom of articles. Template parameters[Edit template data] The initial visibility of the navbox Template transclusions |
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[SOURCE: https://en.wikipedia.org/wiki/Hydrogen] | [TOKENS: 8068] |
Contents Hydrogen Hydrogen is a chemical element; it has the symbol H and atomic number 1. It is the lightest and most abundant chemical element in the universe, constituting about 75% of all normal matter. Under standard conditions, hydrogen is a gas of diatomic molecules with the formula H2, called dihydrogen, or sometimes hydrogen gas, molecular hydrogen, or simply hydrogen. Dihydrogen is colorless, odorless, non-toxic, and highly combustible. Stars, including the Sun, mainly consist of hydrogen in a plasma state, while on Earth, hydrogen is found as the gas H2 (dihydrogen) and in molecules, such as in water and organic compounds. The most common isotope of hydrogen, 1H, consists of one proton, one electron, and no neutrons. Hydrogen gas was first produced artificially in the 17th century by the reaction of acids with metals. Henry Cavendish, in 1766–1781, identified hydrogen gas as a distinct substance and discovered its property of producing water when burned: this is the origin of hydrogen's name, which means 'water-former' (from Ancient Greek: ὕδωρ, romanized: húdōr, lit. 'water', and γεννάω, gennáō, 'I bring forth'). Understanding the colors of light absorbed and emitted by hydrogen was a crucial part of the development of quantum mechanics. Hydrogen, typically nonmetallic except under extreme pressure, readily forms covalent bonds with most nonmetals, contributing to the formation of compounds like water and various organic substances. Its role is crucial in acid–base reactions, which mainly involve proton exchange among soluble molecules. In ionic compounds, hydrogen can take the form of either a negatively-charged anion, where it is known as hydride, or as a positively-charged cation, H+, hydron. Although tightly bonded to water molecules, hydrons strongly affect the behavior of aqueous solutions, as reflected in the importance of pH. Hydride, on the other hand, is rarely observed because it tends to deprotonate solvents, yielding H2. In the early universe, neutral hydrogen atoms formed about 370,000 years after the Big Bang as the universe expanded and plasma had cooled enough for electrons to remain bound to protons. After stars began to form, most of the hydrogen in the intergalactic medium was re-ionized. Nearly all hydrogen production is done by transforming fossil fuels, particularly steam reforming of natural gas. It can also be produced from water or saline by electrolysis, but this process is more expensive. Its main industrial uses include fossil fuel processing and ammonia production for fertilizer. Emerging uses for hydrogen include the use of fuel cells to generate electricity. Properties The ground state energy level of the electron in a hydrogen atom is −13.6 electronvolts (eV), equivalent to an ultraviolet photon of roughly 91 nanometers wavelength. The energy levels of hydrogen are referred to by consecutive quantum numbers, with n = 1 {\displaystyle n=1} being the ground state. The hydrogen spectral series corresponds to emission of light due to transitions from higher to lower energy levels.: 105 Each energy level is further split by spin interactions between the electron and proton into four hyperfine levels. High-precision values for the hydrogen atom energy levels are required for definitions of physical constants. Quantum calculations have identified nine contributions to the energy levels. The eigenvalue from the Dirac equation is the largest contribution. Other terms include relativistic recoil, the self-energy, and the vacuum polarization terms. The standards organization for chemical names, IUPAC, gives general names when the context assumes natural isotope abundance or ignores the isotope. These general names are hydrogen for the neutral atom, hydron for the positive cation, H+, hydride for the negative cation, H-. The name proton is often used for the positive cation but this strictly correct only for the cation of the dominant isotope 1H. Hydrogen has three naturally-occurring isotopes, denoted 1H, 2H and 3H. Other, highly-unstable nuclides (4H to 7H) have been synthesized in laboratories but not observed in nature. 1H is the most common hydrogen isotope, with an abundance of >99.98%. Because the nucleus of this isotope consists of only a single proton, it is given the descriptive but rarely used formal name protium. It is the only stable isotope with no neutrons (see diproton for a discussion of why others do not exist). 2H, the other stable hydrogen isotope, is known as deuterium and contains one proton and one neutron in the nucleus. Nearly all deuterium nuclei in the universe are thought to have been produced in Big Bang nucleosynthesis, and have endured since then.: 24.2 Deuterium is not radioactive, and is not a significant toxicity hazard. Water enriched in molecules that include deuterium instead of normal hydrogen is called heavy water. Deuterium and its compounds are used as a non-radioactive label in chemical experiments and in solvents for 1H-NMR spectroscopy. Heavy water is used as a neutron moderator and coolant for nuclear reactors. Deuterium is also a potential fuel for commercial nuclear fusion. 3H is known as tritium and contains one proton and two neutrons in its nucleus. It is radioactive, decaying into helium-3 through beta decay with a half-life of 12.32 years. It is radioactive enough to be used in luminous paint to enhance the visibility of data displays, such as for painting the hands and dial-markers of watches. The watch glass prevents the small amount of radiation from escaping the case. Small amounts of tritium are produced naturally by cosmic rays striking atmospheric gases; tritium has also been released in nuclear weapons tests. It is used in nuclear fusion, as a tracer in isotope geochemistry, and in specialized self-powered lighting devices. Tritium has also been used in chemical and biological labeling experiments as a radiolabel. Unique among the elements, distinct names are assigned to hydrogen's isotopes in common use. During the early study of radioactivity, heavy radioisotopes were given their own names, but these are mostly no longer used. The symbols D and T (instead of 2H and 3H) are sometimes used for deuterium and tritium, but the symbol P was already used for phosphorus and thus was not available for protium. In its nomenclatural guidelines, the International Union of Pure and Applied Chemistry (IUPAC) allows any of D, T, 2H, and 3H to be used, though 2H and 3H are preferred. Antihydrogen (H) is the antimatter counterpart to hydrogen. It consists of an antiproton with a positron. The exotic atom muonium (symbol Mu), composed of an antimuon and an electron, is the antimatter analogue of hydrogen; IUPAC nomenclature incorporates such hypothetical compounds as muonium chloride (MuCl) and sodium muonide (NaMu), analogous to hydrogen chloride and sodium hydride respectively. Under standard conditions, hydrogen is a gas of diatomic molecules with the formula H2, officially called "dihydrogen",: 308 but also called "molecular hydrogen", or simply hydrogen. Dihydrogen is a colorless, odorless, flammable gas. Hydrogen gas is highly flammable, reacting with oxygen in air to produce liquid water: The amount of heat released per mole of hydrogen is −286 kilojoules (kJ), or 141.865 megajoules (MJ) for a one-kilogram (2.2 lb) mass. Hydrogen gas forms explosive mixtures with air in concentrations from 4%–74% and with chlorine at 5%–95%. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C (932 °F). In a high-pressure hydrogen leak, the shock wave from the leak itself can heat air to the autoignition temperature, leading to flaming and possibly explosion. Hydrogen flames emit faint blue and ultraviolet light. Flame detectors are used to detect hydrogen fires as they are nearly invisible to the naked eye in daylight. Molecular H2 exists as two nuclear isomers that differ in the spin states of their nuclei. In the orthohydrogen form, the spins of the two nuclei are parallel, forming a spin triplet state having a total molecular spin S = 1 {\displaystyle S=1} ; in the parahydrogen form the spins are antiparallel and form a spin singlet state having spin S = 0 {\displaystyle S=0} . The equilibrium ratio of ortho- to para-hydrogen depends on temperature. At room temperature or warmer, equilibrium hydrogen gas contains about 25% of the para form and 75% of the ortho form. The ortho form is an excited state, having higher energy than the para form by 1.455 kJ/mol, and it converts to the para form over the course of several minutes when cooled to low temperature. The thermal properties of these isomers differ because each has distinct rotational quantum states. The ortho-to-para ratio in H2 is an important consideration in the liquefaction and storage of liquid hydrogen: the conversion from ortho to para is exothermic, and produces sufficient heat to evaporate most of the liquid if the conversion to parahydrogen does not occur during the cooling process. Catalysts for the ortho-para interconversion, such as ferric oxide and activated carbon compounds, are therefore used during hydrogen cooling to avoid this loss of liquid. Liquid hydrogen can exist at temperatures below hydrogen's critical point of 33 kelvins (−240.2 °C; −400.3 °F). However, for it to be in a fully liquid state at atmospheric pressure, H2 needs to be cooled to 20.28 K (−252.87 °C; −423.17 °F). Hydrogen was liquefied by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. Liquid hydrogen becomes solid hydrogen at standard pressure below hydrogen's melting point of 14.01 K (−259.14 °C; −434.45 °F). Distinct solid phases exist, known as Phase I through Phase V, each exhibiting a characteristic molecular arrangement. Liquid and solid phases can exist in combination at the triple point; this mixture is known as slush hydrogen. Metallic hydrogen, a phase obtained at extremely high pressures (in excess of 400 million Pa (58,000 psi)), is an electrical conductor. It is believed to exist deep within giant planets like Jupiter. When ionized, hydrogen becomes a plasma. This is the form in which hydrogen exists within stars. History In 1671, Irish scientist Robert Boyle discovered and described the reaction between iron filings and dilute acids, which results in the production of hydrogen gas. Boyle did not note that the gas was flammable, but hydrogen would play a key role in overturning the phlogiston theory of combustion. In 1766, Henry Cavendish was the first to recognize hydrogen gas as a discrete substance, by naming the gas from a metal-acid reaction "inflammable air". He speculated that "inflammable air" was in fact identical to the hypothetical substance "phlogiston" and further finding in 1781 that the gas produces water when burned. He is usually given credit for the discovery of hydrogen as an element. In 1783, Antoine Lavoisier identified the element that came to be known as hydrogen when he and Laplace reproduced Cavendish's finding that water is produced when hydrogen is burned. Lavoisier produced hydrogen for his experiments on mass conservation by treating metallic iron with a stream of water through an incandescent iron tube heated in a fire. Anaerobic oxidation of iron by the protons of water at high temperature can be schematically represented by the set of following reactions: Many metals react similarly with water, leading to the production of hydrogen. In some situations, this H2-producing process is problematic, for instance in the case of zirconium cladding on nuclear fuel rods. By 1806 hydrogen was used to fill balloons. François Isaac de Rivaz built the first de Rivaz engine, an internal combustion engine powered by a mixture of hydrogen and oxygen, in 1806. Edward Daniel Clarke invented the hydrogen gas blowpipe in 1819. The Döbereiner's lamp and limelight were invented in 1823. Hydrogen was liquefied for the first time by James Dewar in 1898 by using regenerative cooling and his invention, the vacuum flask. He produced solid hydrogen the next year. One of the first quantum effects to be explicitly noticed, although not understood at the time, was James Clerk Maxwell's observation that the specific heat capacity of H2 unaccountably departs from that of a diatomic gas below room temperature, and begins to increasingly resemble that of a monatomic gas at cryogenic temperatures. According to quantum theory, this behavior arises from the spacing of the (quantized) rotational energy levels, which are particularly wide-spaced in H2 because of its low mass. These widely-spaced levels inhibit equal partition of heat energy into rotational motion in hydrogen at low temperatures. Diatomic gases composed of heavier atoms do not have such widely spaced levels and do not exhibit the same effect. The existence of the hydride anion was suggested by Gilbert N. Lewis in 1916 for group 1 and group 2 salt-like compounds. In 1920, Moers electrolyzed molten lithium hydride (LiH), producing a stoichiometric quantity of hydrogen at the anode. Because of its simple atomic structure, consisting only of a proton and an electron, the hydrogen atom, together with the spectrum of light produced from it or absorbed by it, has been central to the development of the theory of atomic structure. The energy levels of hydrogen can be calculated fairly accurately using the Bohr model of the atom, in which the electron "orbits" the proton, like how Earth orbits the Sun. However, the electron and proton are held together by electrostatic attraction, while planets and celestial objects are held by gravity. Due to the discretization of angular momentum postulated in early quantum mechanics by Bohr, the electron in the Bohr model can only occupy certain allowed distances from the proton, and therefore only certain allowed energies. Hydrogen's unique position as the only neutral atom for which the Schrödinger equation can be directly solved, has significantly contributed to the understanding of quantum mechanics through the exploration of its energetics. Furthermore, study of the corresponding simplicity of the hydrogen molecule and the corresponding cation, H+2, brought understanding of the nature of the chemical bond, which followed shortly after the quantum mechanical treatment of the hydrogen atom had been developed in the mid-1920s. Because H2 has only 7% the density of air, it was once widely used as a lifting gas in balloons and airships. The first hydrogen-filled balloon was invented by Jacques Charles in 1783. Hydrogen provided the lift for the first reliable form of air-travel following the 1852 invention of the first hydrogen-lifted airship by Henri Giffard. German count Ferdinand von Zeppelin promoted the idea of rigid airships lifted by hydrogen that later were called Zeppelins, the first of which had its maiden flight in 1900. Regularly-scheduled flights started in 1910 and by the outbreak of World War I in August 1914, they had carried 35,000 passengers without a serious incident. Hydrogen-lifted airships in the form of blimps were used as observation platforms and bombers during World War II, especially on the US Eastern seaboard. The first non-stop transatlantic crossing was made by the British airship R34 in 1919 and regular passenger service resumed in the 1920s. Hydrogen was used in the Hindenburg, which caught fire over New Jersey on 6 May 1937. The hydrogen that filled the airship was ignited, possibly by static electricity, and burst into flames. Following this disaster, commercial hydrogen airship travel ceased. Hydrogen is still used, in preference to non-flammable but more expensive helium, as a lifting gas for weather balloons. Deuterium was discovered in December 1931 by Harold Urey, and tritium was prepared in 1934 by Ernest Rutherford, Mark Oliphant, and Paul Harteck. Heavy water, which consists of deuterium in the place of regular hydrogen, was discovered by Urey's group in 1932. Chemistry H2 is relatively unreactive. The thermodynamic basis of this low reactivity is the very strong H–H bond, with a bond dissociation energy of 435.7 kJ/mol. It does form coordination complexes called dihydrogen complexes. These species provide insights into the early steps in the interactions of hydrogen with metal catalysts. According to neutron diffraction, the metal and two H atoms form a triangle in these complexes. The H-H bond remains intact but is elongated. They are acidic. Although exotic on Earth, the H+3 ion is common in the universe. It is a triangular species, like the aforementioned dihydrogen complexes. It is known as protonated molecular hydrogen or the trihydrogen cation. Hydrogen reacts with chlorine to produce HCl, and with bromine to produce HBr, via a chain reaction. The reaction requires initiation. For example, in the case of Br2, the dibromine molecule is split apart: Br2 + (UV light) → 2Br•. Propagating reactions consume hydrogen molecules and produce HBr, as well as Br and H atoms: Finally the terminating reaction: consumes the remaining atoms.: 289 The addition of H2 to unsaturated organic compounds, such as alkenes and alkynes, is called hydrogenation. Even if the reaction is energetically favorable, it does not occur spontaneously even at higher temperatures. In the presence of a catalyst like finely divided platinum or nickel, the reaction proceeds at room temperature.: 477 Hydrogen can exist in both +1 and −1 oxidation states, forming compounds through ionic and covalent bonding. The element is part of a wide range of substances, including water, hydrocarbons, and numerous other organic compounds. The H+ ion—commonly referred to as a proton due to its single proton and absence of electrons—is central to acid–base chemistry, although the proton does not move freely. In the Brønsted–Lowry framework, acids are defined by their ability to donate H+ ions to bases. Hydrogen forms a vast variety of compounds with carbon, known as hydrocarbons, and an even greater diversity with other elements (heteroatoms), giving rise to the broad class of organic compounds often associated with living organisms. Hydrogen compounds with hydrogen in the oxidation state −1 are known as hydrides, which are usually formed between hydrogen and metals. The hydrides can be ionic (aka saline), covalent, or metallic. With heating, H2 reacts efficiently with the alkali and alkaline earth metals to give the ionic hydrides of the formulas MH and MH2, respectively. These salt-like crystalline compounds have high melting points and all react with water to liberate hydrogen. Covalent hydrides include boranes and polymeric aluminium hydride. Transition metals form metal hydrides via continuous dissolution of hydrogen into the metal. A well-known hydride is lithium aluminium hydride: the [AlH4]− anion carries hydridic centers firmly attached to the Al(III). Perhaps the most extensive series of hydrides are the boranes, compounds consisting only of boron and hydrogen. Hydrides can bond to these electropositive elements not only as a terminal ligand but also as bridging ligands. In diborane (B2H6), four hydrogen atoms are terminal, while two bridge between the two boron atoms. When bonded to a more electronegative element, particularly fluorine, oxygen, or nitrogen, hydrogen can participate in a form of medium-strength noncovalent bonding with another electronegative element with a lone pair like oxygen or nitrogen. This phenomenon, called hydrogen bonding, is critical to the stability of many biological molecules.: 375 Hydrogen bonding alters molecule structures, viscosity, solubility, melting and boiling points, and even protein folding dynamics. In water, hydrogen bonding plays an important role in reaction thermodynamics. A hydrogen bond can shift over to proton transfer. Under the Brønsted–Lowry acid–base theory, acids are proton donors, while bases are proton acceptors.: 28 A bare proton (H+) essentially cannot exist in anything other than a vacuum. Otherwise it attaches to other atoms, ions, or molecules. Even chemical species as inert as methane can be protonated. The term "proton" is used loosely and metaphorically to refer to solvated hydrogen cations attached to other solvated chemical species; it is denoted "H+" without any implication that any single protons exist freely in solution as a species. To avoid the implication of the naked proton in solution, acidic aqueous solutions are sometimes considered to contain the "hydronium ion" ([H3O]+), or still more accurately, [H9O4]+. Other oxonium ions are found when water is in acidic solution with other solvents. The concentration of these solvated protons determines the pH of a solution, a logarithmic scale that reflects its acidity or basicity. Lower pH values indicate higher concentrations of hydronium ions, corresponding to more acidic conditions. Occurrence Hydrogen, as atomic H, is the most abundant chemical element in the universe, making up 75% of normal matter by mass. and >90% by number of atoms. In the early universe, protons formed in the first second after the Big Bang; neutral hydrogen atoms formed about 370,000 years later during the recombination epoch as the universe expanded and plasma had cooled enough for electrons to remain bound to protons. In astrophysics, neutral hydrogen in the interstellar medium is called H I and ionized hydrogen is called H II. Radiation from stars ionizes H I to H II, creating spheres of ionized H II around stars. In the chronology of the universe neutral hydrogen dominated until the birth of stars during the era of reionization, which then produced bubbles of ionized hydrogen that grew and merged over hundreds of millions of years. These are the source of the 21-centimeter hydrogen line, at 1420 MHz, that is detected in order to probe primordial hydrogen. The large amount of neutral hydrogen found in the damped Lyman-alpha systems is thought to dominate the cosmological baryonic density of the universe up to a redshift of z = 4. Hydrogen is found in great abundance in stars and gas giant planets. Molecular clouds of H2 are associated with star formation. Hydrogen plays a vital role in powering stars through the proton-proton reaction in lower-mass stars, and through the CNO cycle of nuclear fusion in stars more massive than the Sun. Protonated molecular hydrogen (H+3) is found in the interstellar medium, where it is generated by ionization of molecular hydrogen by cosmic rays. This ion has also been observed in the upper atmosphere of Jupiter. The ion is long-lived in outer space due to the low temperature and density. H+3 is one of the most abundant ions in the universe, and it plays a notable role in the chemistry of the interstellar medium. Neutral triatomic hydrogen H3 can exist only in an excited form and is unstable. Hydrogen is the third most abundant element on the Earth's surface, mostly existing within chemical compounds such as hydrocarbons and water. Elemental hydrogen is normally in the form of a gas, H2, at standard conditions. It is present in a very low concentration in Earth's atmosphere (around 0.53 parts per million on a molar basis) because of its light weight, which enables it to escape the atmosphere more rapidly than heavier gases. Despite its low concentration in the atmosphere, terrestrial hydrogen is sufficiently abundant to support the metabolism of several varieties of bacteria. Large underground deposits of hydrogen gas have been discovered in several countries including Mali, France and Australia. As of 2024, it is uncertain how much underground hydrogen can be extracted economically. Production and storage Nearly all of the world's current supply of hydrogen gas (H2) is produced from fossil fuels.: 1 Many methods exist for producing H2, but three dominate commercially: steam reforming often coupled to water-gas shift, partial oxidation of hydrocarbons, and water electrolysis. Hydrogen is mainly produced by steam methane reforming (SMR), the reaction of water and methane. Thus, at high temperature (1,000–1,400 K [730–1,130 °C; 1,340–2,060 °F]), steam (water vapor) reacts with methane to yield carbon monoxide and H2. Producing one tonne of hydrogen through this process emits 6.6–9.3 tonnes of carbon dioxide. The production of natural gas feedstock also produces emissions such as vented and fugitive methane, which further contributes to the overall carbon footprint of hydrogen. This reaction is favored at low pressures but is nonetheless conducted at high pressures (2.0 MPa [20 atm; 590 inHg]) because high-pressure H2 is the most marketable product, and pressure swing adsorption (PSA) purification systems work better at higher pressures. The product mixture is known as "synthesis gas" because it is often used directly for the production of methanol and many other compounds. Hydrocarbons other than methane can be used to produce synthesis gas with varying product ratios. One of the many complications to this highly-optimized technology is the formation of coke or carbon: Therefore, steam reforming typically employs an excess of H2O. Additional hydrogen can be recovered from the steam by using carbon monoxide through the water gas shift reaction (WGS). This process requires an iron oxide catalyst: Hydrogen is sometimes produced and consumed in the same industrial process, without being separated. In the Haber process for ammonia production, hydrogen is generated from natural gas. Other methods for CO and H2 production include partial oxidation of hydrocarbons: Although less important commercially, coal can serve as a prelude to the above shift reaction: Olefin production units may produce substantial quantities of byproduct hydrogen, particularly from cracking light feedstocks like ethane or propane. Electrolysis of water is a conceptually simple method of producing hydrogen. Commercial electrolyzers use nickel-based catalysts in strongly alkaline solution. Platinum is a better catalyst but is expensive. The hydrogen created through electrolysis using renewable energy is commonly referred to as "green hydrogen". Electrolysis of brine to yield chlorine also produces high-purity hydrogen as a co-product, which is used for a variety of transformations such as hydrogenations. The electrolysis process is more expensive than producing hydrogen from methane without carbon capture and storage. Innovation in hydrogen electrolyzers could make large-scale production of hydrogen from electricity more cost-competitive. Hydrogen can be produced by pyrolysis of natural gas (methane), producing hydrogen gas and solid carbon with the aid of a catalyst and 74 kJ/mol input heat: The carbon may be sold as a manufacturing feedstock or fuel, or landfilled. This route could have a lower carbon footprint than existing hydrogen production processes, but mechanisms for removing the carbon and preventing it from reacting with the catalyst remain obstacles for industrial-scale use.: 17 Water splitting is the process by which water is decomposed into its components. Relevant to the biological scenario is this equation: The reaction occurs in the light-dependent reactions in all photosynthetic organisms. A few organisms, including the alga Chlamydomonas reinhardtii and cyanobacteria, have evolved a second step in the dark reactions in which protons and electrons are reduced to form H2 gas by specialized hydrogenases in the chloroplast. Efforts have been undertaken to genetically modify cyanobacterial hydrogenases to more efficiently generate H2 gas even in the presence of oxygen. Efforts have also been undertaken with genetically‐modified alga in a bioreactor. Relevant to the thermal water-splitting scenario is this simple equation: Over 200 thermochemical cycles can be used for water splitting. Many of these cycles such as the iron oxide cycle, cerium(IV) oxide–cerium(III) oxide cycle, zinc–zinc oxide cycle, sulfur–iodine cycle, copper–chlorine cycle and hybrid sulfur cycle have been evaluated for their commercial potential to produce hydrogen and oxygen from water and heat without using electricity. A number of labs (including in France, Germany, Greece, Japan, and the United States) are developing thermochemical methods to produce hydrogen from solar energy and water. H2 is produced in organisms by enzymes called hydrogenases. This process allows the host organism to use fermentation as a source of energy. These same enzymes also can oxidize H2, such that the host organisms can subsist by reducing oxidized substrates using electrons extracted from H2. Hydrogenase enzymes feature iron or iron–nickel centers at their active sites. The natural cycle of hydrogen production and consumption by organisms is called the hydrogen cycle. Some bacteria such as Mycobacterium smegmatis can use the small amount of hydrogen in the atmosphere as a source of energy when other sources are lacking. Their hydrogenases feature small channels that exclude oxygen from the active site, permitting the reaction to occur even though the hydrogen concentration is very low and the oxygen concentration is as in normal air. Confirming the existence of hydrogenase‐employing microbes in the human gut, H2 occurs in human breath. The concentration in the breath of fasting people at rest is typically under 5 parts per million (ppm), but can reach 50 ppm when people with intestinal disorders consume molecules they cannot absorb during diagnostic hydrogen breath tests. Serpentinization is a geological mechanism which produces highly-reducing conditions. Under these conditions, water is capable of oxidizing ferrous (Fe2+) ions in fayalite, generating hydrogen gas: Closely related to this geological process is the Schikorr reaction: This process also is relevant to the corrosion of iron and steel in oxygen-free groundwater and in reducing soils below the water table. H2 is produced in laboratory settings, such as in the small-scale electrolysis of water using metal electrodes and water containing an electrolyte, which liberates hydrogen gas at the cathode: Hydrogen is also often a by-product of other reactions. Many metals react with water to produce H2, but the rate of hydrogen evolution depends on the metal, the pH, and the presence of alloying agents. Most often, hydrogen evolution is induced by acids. The alkali and alkaline earth metals as well as aluminium, zinc, manganese, and iron, react readily with aqueous acids. Many metals, such as aluminium, are slow to react with water because they form passivated oxide coatings. An alloy of aluminium and gallium, however, does react with water. In high-pH solutions, aluminium can react with H2: If H2 is to be used as an energy source, its storage is important. It dissolves only poorly in solvents. For example, at room temperature and 0.1 millipascals (9.9×10−10 atm), approx. 0.05 moles of hydrogen dissolve into one kilogram (2.2 lb) of diethyl ether. H2 can be stored in compressed form, although compressing costs energy. Liquefaction is impractical given hydrogen's low critical temperature. In contrast, ammonia and many hydrocarbons can be liquified at room temperature under pressure. For these reasons, hydrogen carriers—materials that reversibly bind H2—have attracted much attention. The key question is then the weight percent of H2-equivalents within the carrier material. For example, hydrogen can be reversibly absorbed into many rare earths and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladium disks, but the gas's high solubility is also a metallurgical problem, contributing to the embrittlement of many metals, complicating the design of pipelines and storage tanks. The most problematic aspect of metal hydrides for storage is their modest H2 content, often on the order of 1%. For this reason, there is interest in storage of H2 in compounds of low molecular weight. For example, ammonia borane (H3N−BH3) contains 19.8 weight percent of H2. The problem with this material is that after release of H2, the resulting boron nitride does not re-add H2: i.e., ammonia borane is an irreversible hydrogen carrier. More attractive are hydrocarbons such as tetrahydroquinoline, which reversibly release some H2 when heated in the presence of a catalyst: Applications Large quantities of H2 are used in the "upgrading" of fossil fuels. Key consumers of H2 include hydrodesulfurization and hydrocracking. Many of these reactions can be classified as hydrogenolysis, i.e., the cleavage of bonds by hydrogen. Illustrative is the separation of sulfur from liquid fossil fuels: Hydrogenation, the addition of H2 to various substrates, is done on a large scale. Hydrogenation of N2 produces ammonia by the Haber process: This process consumes a few percent of the energy budget in the entire industry and is the biggest consumer of hydrogen. The resulting ammonia is used extensively in fertilizer production; these fertilizers have become essential feedstocks in modern agriculture. Hydrogenation is also used to convert unsaturated fats and oils to saturated fats and oils. The major application is the production of margarine. Methanol is produced by hydrogenation of carbon dioxide; the mixture of hydrogen and carbon dioxide used for this process is known as syngas. It is similarly the source of hydrogen in the manufacture of hydrochloric acid. H2 is also used as a reducing agent for the conversion of some ores to the metals. The potential for using hydrogen (H2) as a fuel has been widely discussed. Hydrogen can be used in fuel cells to produce electricity, or burned to generate heat. When hydrogen is consumed in fuel cells, the only emission at the point of use is water vapor. When burned, hydrogen produces relatively little pollution at the point of combustion, but can lead to thermal formation of harmful nitrogen oxides. If hydrogen is produced with low or zero greenhouse gas emissions (green hydrogen), it can play a significant role in decarbonizing energy systems where there are challenges and limitations to replacing fossil fuels with direct use of electricity. Hydrogen fuel can produce the intense heat required for industrial production of steel, cement, glass, and chemicals, thus contributing to the decarbonization of industry alongside other technologies, such as electric arc furnaces for steelmaking. However, it is likely to play a larger role in providing industrial feedstock for cleaner production of ammonia and organic chemicals. For example, in steelmaking, hydrogen could function as a clean fuel and also as a low-carbon catalyst, replacing coal-derived coke (carbon): Hydrogen used to decarbonize transportation is likely to find its largest applications in shipping, aviation and, to a lesser extent, heavy goods vehicles, through the use of hydrogen-derived synthetic fuels such as ammonia and methanol and fuel cell technology. For light-duty vehicles including cars, hydrogen is far behind other alternative fuel vehicles, especially compared with the rate of adoption of battery electric vehicles, and may not play a significant role in future. Liquid hydrogen and liquid oxygen together serve as cryogenic propellants in liquid-propellant rockets, as in the Space Shuttle main engines. NASA has investigated the use of rocket propellant made from atomic hydrogen, boron or carbon that is frozen into solid molecular hydrogen particles suspended in liquid helium. Upon warming, the mixture vaporizes to allow the atomic species to recombine, heating the mixture to high temperature. Hydrogen produced when there is a surplus of variable renewable electricity could in principle be stored and later used to generate heat or to re-generate electricity. It can be further transformed into synthetic fuels such as ammonia and methanol. Disadvantages of hydrogen fuel include high costs of storage and distribution due to hydrogen's explosivity, its large volume compared to other fuels, and its tendency to embrittle materials. The very long-lived, rechargeable nickel–hydrogen battery developed for satellite power systems uses pressurized gaseous H2. The International Space Station, Mars Odyssey and the Mars Global Surveyor are equipped with nickel-hydrogen batteries. In the dark part of its orbit, the Hubble Space Telescope is also powered by nickel-hydrogen batteries, which were finally replaced in May 2009, more than 19 years after launch and 13 years beyond their design life. Hydrogen is employed in semiconductor manufacturing to saturate broken ("dangling") bonds of amorphous silicon and amorphous carbon, which helps in stabilizing the materials' properties. Hydrogen, introduced as an unintended side-effect of production, acts as a shallow electron donor leading to n-type conductivity in ZnO, with important uses in transducers and phosphors. Detailed analysis of ZnO and of MgO shows evidence of four and six-fold hydrogen multicentre bonds. The doping behavior of hydrogen varies with material. Beyond than the uses mentioned above, hydrogen is used in smaller scales in the following applications: Safety and precautions In hydrogen pipelines and steel storage vessels, hydrogen molecules are prone to reacting with metals, causing hydrogen embrittlement and leaks in the pipeline or storage vessel. Since it is lighter than air, hydrogen does not easily accumulate to form a combustible gas mixture. However, even without ignition sources, high-pressure hydrogen leakage may cause spontaneous combustion and detonation. Hydrogen is flammable when mixed even in small amounts with air. Ignition can occur at a volumetric ratio of hydrogen to air as low as 4%. In approximately 70% of hydrogen ignition accidents, the ignition source cannot be determined. Hydrogen fire, while being extremely hot, is almost invisible to the human eye, and thus can lead to accidental burns. Hydrogen is non-toxic, but like most gases it can cause asphyxiation in the absence of adequate ventilation. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Knowledge_Interchange_Format] | [TOKENS: 358] |
Contents Knowledge Interchange Format Knowledge Interchange Format (KIF) is a computer language designed to enable systems to share and re-use information from knowledge-based systems. KIF is similar to frame languages such as KL-One and LOOM but unlike such language its primary role is not intended as a framework for the expression or use of knowledge but rather for the interchange of knowledge between systems. The designers of KIF likened it to PostScript. PostScript was not designed primarily as a language to store and manipulate documents but rather as an interchange format for systems and devices to share documents. In the same way KIF is meant to facilitate sharing of knowledge across different systems that use different languages, formalisms, platforms, etc. KIF has a declarative semantics. It is meant to describe facts about the world rather than processes or procedures. Knowledge can be described as objects, functions, relations, and rules. It is a formal language, i.e., it can express arbitrary statements in first order logic and can support reasoners that can prove the consistency of a set of KIF statements. KIF also supports non-monotonic reasoning. KIF was created by Michael Genesereth, Richard Fikes and others participating in the DARPA knowledge sharing Effort. Although the original KIF group intended to submit to a formal standards body, that did not occur. A later version called Common Logic has since been developed for submission to ISO and has been approved and published. A variant called SUO-KIF is the language in which the Suggested Upper Merged Ontology is written. A practical application of the Knowledge interchange format is an agent communication language in a multi-agent system. See also References External links This computer science article is a stub. You can help Wikipedia by adding missing information. |
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[SOURCE: https://en.wikipedia.org/wiki/Comedy_troupe] | [TOKENS: 167] |
Contents Comedy troupe A comedy troupe is a group of comedians and associated personnel who work together to perform comedy as entertainment. The term is often used interchangeably with comedy group, and the troupe may specialize in a specific genre or style of comedy. Some examples of comedy troupes include: the Marx Brothers, the Three Stooges, Laurel and Hardy, Martin and Lewis, Abbott and Costello, Cheech & Chong, the Second City, Kalabhavan, the Firesign Theatre, Monty Python, Blue Collar Comedy Tour, the Kids in the Hall, the Mighty Boosh, the Trailer Park Boys, The Whitest Kids U' Know, the Tenderloins, the Hollow Men, Asperger's Are Us, Kummeli, Senario, and Them There. See also References |
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[SOURCE: https://en.wikipedia.org/wiki/Fast_radio_burst] | [TOKENS: 8949] |
Contents Fast radio burst In radio astronomy, a fast radio burst (FRB) is a transient radio wave of length ranging from a fraction of a millisecond, for an ultra-fast radio burst, to 3 seconds, caused by a high-energy astrophysical process that is not yet understood. Astronomers estimate the average FRB releases as much energy in a millisecond as the Sun puts out in three days. While extremely energetic at their source, the strength of the signal reaching Earth has been described as 1,000 times less than from a mobile phone on the Moon. The first FRB was discovered by Duncan Lorimer and his student David Narkevic in 2007 when they were looking through archival pulsar survey data, and it is therefore commonly referred to as the Lorimer burst. Many FRBs have since been recorded, including several that have been detected repeating in seemingly irregular ways. Only one FRB has been detected to repeat in a regular way: FRB 180916 seems to pulse every 16.35 days. Most FRBs are extragalactic, but the first Milky Way FRB was detected by the CHIME radio telescope in April 2020. In June 2021, astronomers reported over 500 FRBs from outer space detected in one year. When FRBs are polarized, it indicates that they are emitted from a source contained within an extremely powerful magnetic field. The exact origin and cause of FRBs is still the subject of investigation; proposals for their origin range from a rapidly rotating neutron star and a black hole, to extraterrestrial intelligence. In 2020, astronomers reported narrowing down a source of fast radio bursts, which may now plausibly include "compact-object mergers and magnetars arising from normal core collapse supernovae". A neutron star has been proposed as the origin of an unusual FRB with periodic peaks lasting over 3 seconds reported in 2022. The discovery in 2012 of the first repeating source, FRB 121102, and its localization and characterization in 2017, has improved the understanding of the source class. FRB 121102 is identified with a galaxy at a distance of approximately three billion light-years and is embedded in an extreme environment. The first host galaxy identified for a non-repeating burst, FRB 180924, was identified in 2019 and is a much larger and more ordinary galaxy, nearly the size of the Milky Way. In August 2019, astronomers reported the detection of eight more repeating FRB signals. In January 2020, astronomers reported the precise location of a second repeating burst, FRB 180916. One FRB seems to have been in the same location as a known gamma-ray burst. On 28 April 2020, a pair of millisecond-timescale bursts (FRB 200428) consistent with observed fast radio bursts, with a fluence of >1.5 million Jy ms, was detected from the same area of sky as the magnetar SGR 1935+2154. Although it was thousands of times less intrinsically bright than previously observed fast radio bursts, its comparative proximity (within our galaxy) rendered it the most powerful fast radio burst yet observed, reaching a peak flux of either a few thousand or several hundred thousand janskys, comparable to the brightness of the radio sources Cassiopeia A and Cygnus A at the same frequencies. This established magnetars as, at least, one ultimate source of fast radio bursts, although the exact cause remains unknown. Further studies support the notion that magnetars may be closely associated with FRBs. On 13 October 2021, astronomers reported the detection of hundreds of FRBs from a single system. In 2024, an international team led by astrophysicists of INAF, using detections from VLA, NOEMA interferometer, and Gran Telescopio Canarias has conducted a research campaign about FRB20201124A, one of the two known persistent FRB, located about 1.3 billion light-years away. Based on the outcomes of the study, authors deem to confirm the origin of FRBs in a binary system at high accretion rate, that would blow a plasma bubble, responsible for the persistent radio emission. The emission object, i.e. the "bubble", would be immersed in a star-forming region. Detection The first fast radio burst to be described, the Lorimer Burst FRB 010724, was found in 2007 in archived data recorded by the Parkes Observatory on 24 July 2001. Since then, many FRBs have been found in previously recorded data. On 19 January 2015, astronomers at Australia's national science agency (CSIRO) reported that a fast radio burst had been observed for the first time live, by the Parkes Observatory. Many FRBs have been detected in real time by the CHIME radio telescope since it became operational in 2018, including the first FRB detected from within the Milky Way in April 2020. In January 2025, astronomers discovered radio waves from a galaxy that is roughly 2-billion light years away from Earth and is believed to be more than 11 billion years old. These FRBs are associated with a galaxy that was believed to be dead. Features Fast radio bursts are bright, unresolved (pointsource-like), broadband (spanning a large range of radio frequencies), millisecond flashes found in parts of the sky. Unlike many radio sources, the signal from a burst is detected in a short period of time with enough strength to stand out from the noise floor. The burst usually appears as a single spike of energy without any change in its strength over time. The bursts last for several milliseconds (thousandths of a second). The bursts come from all over the sky, and are not concentrated on the plane of the Milky Way. Known FRB locations are biased by the parts of the sky that the observatories can image. Many have radio frequencies detected around 1400 MHz; a few have been detected at lower frequencies in the range of 400–800 MHz. The component frequencies of each burst are delayed by different amounts of time depending on the wavelength. This delay is described by a value referred to as a dispersion measure (DM). This results in a received signal that sweeps rapidly down in frequency, as longer wavelengths are delayed more. The interferometer UTMOST has put a lower limit of 10,000 kilometers for the distance to the FRBs it has detected, supporting the case for an astronomical, rather than terrestrial, origin (because signal sources on Earth are ruled out as being closer than this limit). This limit can be determined from the fact that closer sources would have a curved wave front that could be detected by the multiple antennas of the interferometer. Fast radio bursts have pulse dispersion measurements > 100 pc cm−3, much larger than expected for a source inside the Milky Way galaxy and consistent with propagation through an ionized plasma. Furthermore, their distribution is isotropic (not especially coming from the galactic plane);: fig 3 consequently they are conjectured to be of extragalactic origin. Origin hypotheses Because of the isolated nature of the observed phenomenon, the nature of the source remains speculative. As of 2022[update], there is no generally accepted single explanation, although a magnetar has been identified as a possible source. The sources are thought to be a few hundred kilometers or less in size, as the bursts last for only a few milliseconds. Causation is limited by the speed of light, about 300 km per millisecond, so if the sources were larger than about 1000 km, a complex synchronization mechanism would be required for the bursts to be so short. If the bursts come from cosmological distances, their sources must be very energetic. Extending the technique of measuring pulsar emission region sizes using a scattering screen in the Milky Way, a method to estimate the transverse FRB emission region size using a scattering screen in the host galaxy was formulated in 2024. Within the same year, a previously recorded burst, FRB 202210122A, was constrained to have an emission region size less than 30,000 km, using this technique. One possible explanation would be a collision between very dense objects like merging black holes or neutron stars. It has been suggested that there is a connection to gamma-ray bursts. Some have speculated that these signals might be artificial in origin, that they may be signs of extraterrestrial intelligence, demonstrating veritable technosignatures. Analogously, when the first pulsar was discovered, it was thought that the fast, regular pulses could possibly originate from a distant civilization, and the source nicknamed "LGM-1" (for "little green men"). In 2007, just after the publication of the e-print with the first discovery, it was proposed that fast radio bursts could be related to hyperflares of magnetars. In 2015 three studies supported the magnetar hypothesis. The identification of first FRB from the Milky Way, which originated from the magnetar SGR 1935+2154, indicates that magnetars may be one source of FRB. Especially energetic supernovae could be the source of these bursts. Blitzars were proposed in 2013 as an explanation. In 2014 it was suggested that following dark matter-induced collapse of pulsars, the resulting expulsion of the pulsar magnetospheres could be the source of fast radio bursts. In 2015 it was suggested that FRBs are caused by explosive decays of axion miniclusters. Another exotic possible source are cosmic strings that produced these bursts as they interacted with the plasma that permeated the early Universe. In 2016 the collapse of the magnetospheres of Kerr–Newman black holes were proposed to explain the origin of the FRBs' "afterglow" and the weak gamma-ray transient 0.4 s after GW 150914. It has also been proposed that if fast radio bursts originate in black hole explosions, FRBs would be the first detection of quantum gravity effects. In early 2017, it was proposed that the strong magnetic field near a supermassive black hole could destabilize the current sheets within a pulsar's magnetosphere, releasing trapped energy to power the FRBs. A variety of plasma-based mechanisms have been proposed to explain the coherent radio emission observed in FRBs. These processes typically involve relativistic magnetized plasmas, such as those found near magnetars or in shocks, where collective plasma effects and radiative processes can lead to the generation of bright, short-duration radio pulses. One promising mechanism is coherent electromagnetic emission from relativistic magnetized shocks, where the shock propagates in an electron–positron plasma with high magnetization (σ ≳ 1). These shocks generate X-mode polarized precursor waves through a synchrotron maser–like instability, with efficiencies and spectral features determined self-consistently via particle-in-cell simulations. The shocks can arise from magnetar flares driving relativistic outflows, and may convert a small fraction of their energy (~10-3 σ-1) into coherent radio emission, consistent with observed FRB energetics. Another proposed mechanism is the electron cyclotron maser instability (ECMI), which can be triggered when synchrotron cooling generates ring-shaped momentum distributions that are unstable to X-mode wave growth. This has been demonstrated in simulations of strongly magnetized plasmas where radiative losses sustain the coherent radio emission. Alternative models invoke coherent curvature radiation by bunched charges moving along curved magnetic field lines, often associated with magnetic reconnection near the surface or in the current sheet of neutron stars. In some versions, particle bunching is induced by plasma instabilities or perturbations in the magnetosphere. Other proposals include antenna-type mechanisms, where coherent structures in the plasma (such as charge-separated bunches or solitons) radiate collectively, and free electron laser (FEL)-like processes driven by reconnection-generated particle beams in magnetized turbulence. In these models, particles interact with Alfvénic or electromagnetic wigglers and emit coherently via nonlinear Thomson or Compton-like scattering. Collectively, these plasma-based mechanisms aim to explain the high brightness temperatures, narrow-band spectra, and polarization features of FRBs, and are often framed within the magnetar scenario, although they may operate in broader astrophysical settings. Repeated bursts of FRB 121102 have initiated multiple origin hypotheses. A coherent emission phenomenon known as superradiance, which involves large-scale entangled quantum mechanical states possibly arising in environments such as active galactic nuclei, has been proposed to explain these and other associated observations with FRBs (e.g. high event rate, repeatability, variable intensity profiles). In July 2019, astronomers reported that non-repeating Fast Radio Bursts may not be one-off events, but actually FRB repeaters with repeat events that have gone undetected and, further, that FRBs may be formed by events that have not yet been seen or considered. Additional possibilities include that FRBs may originate from nearby stellar flares. A FRB with multiple periodic component peaks lasting over 3 seconds was reported in 2022. A neutron star has been proposed as the origin of this FRB. Bursts observed Fast radio bursts are named by the date the signal was recorded, as "FRB YYMMDD", with a letter appended to distinguish multiple sources first recorded on the same date. The name is of the presumed source rather than the burst of radio waves, so repeated or subsequent bursts from the same apparent location (eg, FRB 121102) do not get new date names. The first FRB detected, the Lorimer Burst FRB 010724, was discovered in 2007 when Duncan Lorimer of West Virginia University assigned his student David Narkevic to look through archival data taken in 2001 by the Parkes radio dish in Australia. Analysis of the survey data found a 30-jansky dispersed burst which occurred on 24 July 2001, less than 5 milliseconds in duration, located 3° from the Small Magellanic Cloud. The reported burst properties argue against a physical association with the Milky Way galaxy or the Small Magellanic Cloud. The discoverers argue that current models for the free electron content in the Universe imply that the burst is less than 1 gigaparsec distant. The fact that no further bursts were seen in 90 hours of additional observations implies that it was a singular event such as a supernova or merger of relativistic objects. It is suggested that hundreds of similar events could occur every day and if detected could serve as cosmological probes. In 2010 there was a report of 16 similar pulses, clearly of terrestrial origin, detected by the Parkes radio telescope and given the name perytons. In 2015 perytons were shown to be generated when microwave oven doors were opened during a heating cycle, with detected emission being generated by the microwave oven's magnetron tube as it was being powered off. In 2015, FRB 110523 was discovered in archival data collected in 2011 from the Green Bank Telescope. It was the first FRB for which linear polarization was detected (allowing a measurement of Faraday rotation). Measurement of the signal's dispersion delay suggested that this burst was of extragalactic origin, possibly up to 6 billion light-years away. Victoria Kaspi of McGill University estimated that as many as 10,000 fast radio bursts may occur per day over the entire sky. An observation in 2012 of a fast radio burst (FRB 121102) in the direction of Auriga in the northern hemisphere using the Arecibo radio telescope confirmed the extragalactic origin of fast radio pulses by an effect known as plasma dispersion. In November 2015, astronomer Paul Scholz at McGill University in Canada, found ten non-periodically repeated fast radio pulses in archival data gathered in May and June 2015 by the Arecibo radio telescope. The ten bursts have dispersion measures and sky positions consistent with the original burst FRB 121102, detected in 2012. Like the 2012 burst, the 10 bursts have a plasma dispersion measure that is three times larger than possible for a source in the Milky Way Galaxy. The team thinks that this finding rules out self-destructive, cataclysmic events that could occur only once, such as the collision between two neutron stars. According to the scientists, the data support an origin in a young rotating neutron star (pulsar), or in a highly magnetized neutron star (magnetar), or from highly magnetized pulsars travelling through asteroid belts, or from an intermittent Roche lobe overflow in a neutron star-white dwarf binary. On 16 December 2016 six new FRBs were reported in the same direction (one having been received on 13 November 2015, four on 19 November 2015, and one on 8 December 2015).: Table 2 As of January 2019[update] this is one of only two instances in which these signals have been found twice in the same location in space. FRB 121102 is located at least 1150 AU from Earth, excluding the possibility of a human-made source, and is almost certainly extragalactic in nature. As of April 2018, FRB 121102 is thought to be co-located in a dwarf galaxy about three billion light-years from Earth with a low-luminosity active galactic nucleus, or a previously unknown type of extragalactic source, or a young neutron star energising a supernova remnant. On 26 August 2017, astronomers using data from the Green Bank Telescope detected 15 additional repeating FRBs coming from FRB 121102 at 5 to 8 GHz. The researchers also noted that FRB 121102 is presently in a "heightened activity state, and follow-on observations are encouraged, particularly at higher radio frequencies". The waves are highly polarized and undergo Faraday rotation, meaning "twisting" transverse waves, that could have formed only when passing through hot plasma with an extremely strong magnetic field. This rotation of polarized light is quantified by Rotation Measure (RM). FRB 121102's radio bursts have RM about 500 times higher than those from any other FRB to date. Since it is a repeating FRB source, it suggests that it does not come from some one-time cataclysmic event; so one hypothesis, first advanced in January 2018, proposes that these particular repeating bursts may come from a dense stellar core called a neutron star near an extremely powerful magnetic field, such as one near a massive black hole, or one embedded in a nebula. In April 2018, it was reported that FRB 121102 consisted of 21 bursts spanning one hour. In September 2018, an additional 72 bursts spanning five hours had been detected using a convolutional neural network. In September 2019, more repeating signals, 20 pulses on 3 September 2019, were reported to have been detected from FRB 121102 by the Five-hundred-meter Aperture Spherical Telescope (FAST). In June 2020, astronomers from Jodrell Bank Observatory reported that FRB 121102 exhibits the same radio-burst behavior ("radio bursts observed in a window lasting approximately 90 days followed by a silent period of 67 days") every 157 days, suggesting that the bursts may be associated with "the orbital motion of a massive star, a neutron star or a black hole". Subsequent studies by FAST of further activity, consisting of 12 bursts within two hours observed on 17 August 2020, supports an updated refined periodicity between active periods of 156.1 days. Related studies have been reported in October 2021. Further bursts, at least 300, were detected by FAST in August and September 2022. Further related studies were reported in April 2023. In July 2023 19 new burst were reported from existing observations of 121102A that were taken by the Green Bank Telescope, eight of which were extremely short, independent, bursts lasting between 5 and 15 microseconds, the shortest so far detected. In 2013, four bursts were identified that supported the likelihood of extragalactic sources. In 2014, FRB 140514 was caught 'live' and was found to be 21% (±7%) circularly polarised. On 18 April 2015, FRB 150418 was detected by the Parkes observatory and within hours, several telescopes including the Australia Telescope Compact Array caught an apparent radio "afterglow" of the flash, which took six days to fade. The Subaru Telescope was used to find what was thought to be the host galaxy and determine its redshift and the implied distance to the burst. However, the association of the burst with the afterglow was soon disputed, and by April 2016 it was established that the "afterglow" originated from an active galactic nucleus (AGN) that is powered by a supermassive black hole with dual jets blasting outward from the black hole. It was also noted that what was thought to be an afterglow did not fade away as would be expected, supporting the interpretation that it originated in the variable AGN and was not associated with the fast radio burst. The upgraded Molonglo Observatory Synthesis Telescope (UTMOST), near Canberra (Australia), reported finding three more FRBs. A 180-day three-part survey in 2015 and 2016 found three FRBs at 843 MHz. Each FRB located with a narrow elliptical 'beam'; the relatively narrow band 828–858 MHz gives a less precise dispersion measure (DM). A short survey using part of Australian Square Kilometre Array Pathfinder (ASKAP) found one FRB in 3.4 days. FRB170107 was bright with a fluence of 58±6 Jy ms. According to Anastasia Fialkov and Abraham Loeb, FRB's could be occurring as often as once per second. Earlier research could not identify the occurrence of FRB's to this degree. Three FRBs were reported in March 2018 by Parkes Observatory in Australia. One (FRB 180309) had the highest signal-to-noise ratio yet seen of 411. The unusual CHIME (Canadian Hydrogen Intensity Mapping Experiment) radio telescope, operational from September 2018, can be used to detect "hundreds" of fast radio bursts as a secondary objective to its cosmological observations. FRB 180725A was reported by CHIME as the first detection of a FRB under 700 MHz – as low as 580 MHz. In October 2018, astronomers reported 19 more new non-repeating FRB bursts detected by the Australian Square Kilometre Array Pathfinder (ASKAP). These included three with dispersion measure (DM) smaller than seen before : FRB 171020 (DM=114.1), FRB 171213 (DM=158.6), FRB 180212 (DM=167.5). On 9 January 2019, astronomers announced the discovery of a second repeating FRB source, named FRB 180814, by CHIME. Six bursts were detected between August and October 2018, "consistent with originating from a single position on the sky". The detection was made during CHIME's pre-commissioning phase, during which it operated intermittently, suggesting a "substantial population of repeating FRBs", and that the new telescope would make more detections. Some news media reporting of the discovery speculated that the repeating FRB could be evidence of extraterrestrial intelligence, a possibility explored in relation to previous FRBs by some scientists, but not raised by the discoverers of FRB 180814. FRB 180916, more formally FRB 180916.J0158+65, is a repeating FRB discovered by CHIME, that later studies found to have originated from a medium-sized spiral galaxy (SDSS J015800.28+654253.0) about 500 million light-years away – the closest FRB discovered to date. It is also the first FRB observed to have a regular periodicity. Bursts are clustered into a period of about four days, followed by a dormant period of about 12 days, for a total cycle length of 16.35±0.18 days. Additional followup studies of the repeating FRB by the Swift XRT and UVOT instruments were reported on 4 February 2020; by the Sardinia Radio Telescope (SRT) and Medicina Northern Cross Radio Telescope (MNC), on 17 February 2020; and, by the Galileo telescope in Asiago, also on 17 February 2020. Further observations were made by the Chandra X-ray Observatory on 3 and 18 December 2019, with no significant x-ray emissions detected at the FRB 180916 location, or from the host galaxy SDSS J015800.28+654253.0. On 6 April 2020, followup studies by the Global MASTER-Net were reported on The Astronomer's Telegram. On 25 August 2021, further observations were reported. FRB 181112 was mysteriously unaffected after believed to have passed through the halo of an intervening galaxy. FRB 180924 is the first non-repeating FRB to be traced to its source. The source is a galaxy 3.6 billion light-years away. The galaxy is nearly as large as the Milky Way and about 1000 times larger than the source galaxy of FRB 121102. While the latter is an active site of star formation and a likely place for magnetars, the source of FRB 180924 is an older and less active galaxy. Because the FRB was nonrepeating, the astronomers had to scan large areas with the 36 telescopes of ASKAP. Once a signal was found, they used the Very Large Telescope, the Gemini Observatory in Chile, and the W. M. Keck Observatory in Hawaii to identify its host galaxy and determine its distance. Knowledge of the distance and source galaxy properties enables a study of the composition of the intergalactic medium. On 28 June 2019, Russian astronomers reported the discovery of nine FRB events (FRB 121029, FRB 131030, FRB 140212, FRB 141216, FRB 151125.1, FRB 151125.2, FRB 160206, FRB 161202, FRB 180321), which include FRB 151125, the third repeating one ever detected, from the direction of the M 31 (Andromeda Galaxy) and M 33 (Triangulum Galaxy) galaxies during the analysis of archive data (July 2012 to December 2018) produced by the BSA/LPI large phased array radio telescope at the Pushchino Radio Astronomy Observatory. FRB 190520 was observed by the FAST telescope and was localized using the realfast system at the Karl G. Jansky Very Large Array (VLA). Optical observations using the Palomar 200-inch Hale Telescope revealed a host dwarf galaxy at redshift z=0.241. This is the second FRB observed to have an associated Persistent Radio Source (PRS). The dispersion measure(DM) and rotation measure measurements reveals a very dense, magnetized and turbulent environment local to the source. In June 2022, astronomers reported that FRB 20190520B was found to be another repeating FRB. On 12 May 2023, FRB 20190520B was reported to show multiple bursts indicating magnetic field reversal. On 2 July 2019, astronomers reported that FRB 190523, a non-repeating FRB, has been discovered and, notably, localized to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66, nearly 8 billion light-years away from Earth. In August 2019, the CHIME Fast Radio Burst Collaboration reported the detection of eight more repeating FRB signals. On 29 December 2019, Australian astronomers from the Molonglo Observatory Synthesis Telescope (MOST), using the UTMOST fast radio burst equipment, reported the detection of FRB 191223 in the Octans constellation (RA = 20:34:14.14, DEC = -75:08:54.19). On 31 December 2019, Australian astronomers, using the Australian Square Kilometre Array Pathfinder (ASKAP), reported the detection of FRB 191228 in the Piscis Austrinus constellation (RA = 22:57(2), DEC = -29:46(40)). In February & March 2022, astronomers reported that a globular cluster of M81, a grand design spiral galaxy about 12 million light-years away, may be the source of FRB 20200120E, a repeating fast radio burst. Astronomers reported the discovery of FRB 20200317A (RA 16h22m45s, DEC p+56d44m50s) with FAST (Five-hundred-meter Aperture Spherical radio Telescope) in archival data on 22 September 2023. The detected FRB is "one of the faintest FRB sources detected so far", according to the report. On 28 April 2020, astronomers at the Canadian Hydrogen Intensity Mapping Experiment (CHIME), reported the detection of a bright radio burst from the direction of the Galactic magnetar SGR 1935+2154 about 30,000 light years away in the Vulpecula constellation. The burst had a DM of 332.8 pc/cc. The STARE2 team independently detected the burst and reported that the burst had a fluence of >1.5 MJy ms, establishing the connection between this burst and FRBs at extragalactic distances. The burst was then referred to as FRB 200428. The detection is notable, as the STARE2 team claim it is the first ever FRB detected inside the Milky Way, and the first ever to be linked to a known source. That link strongly supports the idea that fast radio bursts emanate from magnetars. On 10 January 2024, astronomers reported that the source of FRB 20200610A was a "rare 'blob-like' group of galaxies". On 24 September 2020, astronomers reported the detection of two new FRBs, FRB200914 and FRB200919, by the Parkes Radio Telescope. Upper limits on low-frequency emission from FRB 200914 were later reported by the Square Kilometre Array radio telescope project. On 31 March 2021, the CHIME/FRB Collaboration reported the detection of FRB 20201124A and related multiple bursts within the week of 23 March 2021 — designated as 20210323A, 20210326A, 20210327A, 20210327B, 20210327C, and 20210328A — and later, likely 20210401A and 20210402A. Further related observations were reported by other astronomers on 6 April 2021, 7 April 2021, and many more as well, including an "extremely bright" pulse on 15 April 2021. Source localization improvements were reported on 3 May 2021. Even more observations were reported in May 2021, including "two bright bursts". On 3 June 2021, the SETI Institute announced detecting "a bright double-peaked radio burst" from FRB 201124A on 18 May 2021. Further observations were made by the Neil Gehrels Swift Observatory on 28 July 2021 and 7 August 7, 2021 without detecting a source on either date. On 23 September 2021, 9 new bursts from FRB 20201124A were reported to have been observed with the Effelsberg 100-m Radio Telescope, followed by one CHIME observation, all after four months of no detections. In January and February 2022, further observations of new bursts from FRB 20201124A with the Westerbork-RT1 25-m telescope were also reported. In mid-March 2022, further observations of FRB 20201124 were reported. In September 2022, astronomers suggested that the repeating FRB 20201124A may originate from a magnetar/Be star binary. On 2 and 3 April 2021, astronomers at the Australian Square Kilometre Array Pathfinder (ASKAP) reported the detection of FRB 20210401A and 20210402A which were understood likely to be repetitions of FRB 20201124A, a repeating FRB with recent very high burst activity, that was reported earlier by the CHIME/FRB collaboration. On 30 June 2021, astronomers at the Molonglo Observatory Synthesis Telescope (UTMOST) detected FRB 210630A at the "likely" position of "RA = 17:23:07.4, DEC =+07:51:42, J2000". On 15 December 2021, astronomers at the Neil Gehrels Swift Observatory reported further observations of the "bright CHIME FRB 20211122A (event #202020046 T0: 2021-12-11T16:58:05.183768)". On 14 April 2022, astronomers at Tianlai Cylinder Pathfinder Array (a radio interferometer located in Xinjiang, China, operated by the National Astronomical Observatory, Chinese Academy of Sciences (NAOC)) detected FRB 220414 (?) ("A bright burst was detected with a S/N~15 for ~2.2 ms duration at UT 17:26:40.368, April 14, 2022 (MJD 59684.06018945136)") located at "RA = 13h04m21s(\pm 2m12s), DEC = +48\deg18'05"(\pm 10'19")". On 19 October 2023, astronomers reported that FRB 20220610A traveled for 8 billion years to reach Earth equivalent at a redshift of z = 1 {\displaystyle z=1} making it the oldest FRB known and also calculated to be the most energetic one with a spectral energy density of ~6.4×1032erg/Hz and a maximum burst energy of ~2×1042erg higher than the previous predicted maximum energy for FRBs. In January 2024, further detailed observations and studies were reported. On 15 October 2022, astronomers at CHIME/FRB reported the detection of nine bursts in three days of FRB 20220912A. Since later bursts observed between 15 October 2022 and 29 October 2022 by the CHIME/FRB collaboration, astronomers, afterwards, at the Allen Telescope Array (ATA), on 1 November 2022, reported eight more bursts from FRB 20220912A. ATA coordinates were first set to the original settings (23h09m05.49s + 48d42m25.6s) and then later to the newly updated ones (23h09m04.9s +48d42m25.4s). On 13 November 2022, further burst activity of FRB 20220912A was reported by the Tianlai Dish Pathfinder Array in Xinjiang, China and, on 5 December 2022, from several other observatories. On 13 December 2022, over a hundred bursts from FRB 220912A were reported by the Upgraded Giant Metrewave Radio Telescope (uGMRT), operated by the National Centre for Radio Astrophysics of the Tata Institute of Fundamental Research in India. On 21 December 2022, several more bright bursts of FRB 220912A using the Westerbork-RT1 were reported. Four more bursts were reported on 13 July 2023 by the Medicina Radio Observatory (specifically by the Medicina Northern Cross (MNC) radio telescope) in Bologna, Italy. Based on four bursts, burst rate constraints of FRB 20220912A at various frequencies using the Green Bank 20-meter telescope were reported on 18 August 2023. Swift X-ray observations were reported on 1 September 2023. On 13 July 2022, the discovery of an unusual FRB 20191221A detected by CHIME was reported. It is a multicomponent pulse (nine or more components) with peaks separated by 216.8ms and lasting an unusually long duration of three seconds. This is the first time such a periodic pulse was detected. On 1 December 2022, astronomers reported the discovery of FRB 20221128A, using the UTMOST-NS radio telescope located in New South Wales, Australia. According to the astronomers, "The most likely position [of FRB 20221128A] is RA = 07:30(10), DEC = -41:32(1), J2000 which corresponds to Galactic coordinates: Gl = 177.1 deg, Gb = 24.45 deg". Later, on 19 January 2023, a corrected position [of FRB 20221128A] was reported as follows: "The revised FRB position is RA = 07:30(10), DEC = -42:30(1) in equatorial (J2000) coordinates, which corresponds to Galactic coordinates: Gl = 255.1 deg, Gb = -11.4 deg (we additionally note that the Galactic coordinates in ATel #15783 were in error)". On 6 December 2022, detection of a possible magnetar gamma-ray burst at or near the same time and location as a fast radio burst was reported. Discovery of FRB 20230814A by the Deep Synoptic Array DSA-110 was reported on 16 August 2023, and was determined to be localized (preliminarily) at 22h23m53.9s +73d01m33.3s (J2000). Observations of FRB 20230905 in the X-ray and UV range by the Neil Gehrels Swift Observatory was reported as bright and non-repeating on 7 September 2023. Discovery of a new repeating FRB 20240114A by the CHIME/FRB Collaboration (at position RA (J2000): 321.9162 +- 0.0087 deg, Dec (J2000): 4.3501 +- 0.0124 degrees) was reported on 26 January 2024. The three bursts from the FRB were detected at "2024-01-14 21:50:39, 2024-01-21 21:30:40, and 2024-01-24 21:20:11 UTC", and associated with a galaxy cluster at 425 Mpc. The dispersion measure DM of the brightest burst was 527.7 pc cm^-3. On 5 February 2024, observations of five repeated bursts of FRB 20240114A on 2 February 2024 were reported using the Parkes/Murriyang Ultra Wideband Low (UWL) receiver system. Also on 5 February 2024, a FRB detection was reported by the Westerbork RT1 25-m telescope. On 8 February 2024, related observations of FRB 20240114A were reported by FAST (38 bursts from 28 January to 4 February) and the Northern Cross Radio Telescope (1 burst on 1 February). Detection and localization studies of FRB 20240114A by MeerKAT in South Africa were reported on 14 February 2024. On 15 February 2024, 10 bursts were reported to have been detected on 1 February 2024 by the Giant Metrewave Radio Telescope (GMRT) in India. On 29 February 2024, 51 bursts (including micro-structure) on 25 February 2024 using uGMRT were reported. On 5 March 2024, a "burst storm" was reported from FRB 20240114A by the FAST radio telescope. On 20 March 2024, the European VLBI Network (EVN) reported several detailed studies, which included observations on 15 February 2024 (7 bursts) and 20 February 2024 (13 bursts), of FRB 20240114A was observed on 17 March 2024240114A. On 21 March 2024, the Northern Cross Radio Telescope in Italy reported a bright radio burst of FRB 20240114A, at updated coordinates of R.A.: 21:27:39.84, Dec: +04:19:46.34 (J2000), on 17 March 2024. On 2 April 2024, astronomers report over 100 detections of FRB 20240114A using five small European radio telescopes. On 18 April 2024, a coincident gamma-ray emission was observed possibly associated with FRB 20240114A. On 23 April 2024, five repeat bursts from FRB 20240114A were reported to have been detected by the Nancay Radio Telescope at 2.5 GHz ("highest frequency to date") on 18 April 2024. On 25 April 2024, eight repeat bursts from FRB 20240114A were reported to have been detected by the Allen Telescope Array (ATA) at frequencies above 2.0 GHz. On 26 April 2024, no counterpart candidates (ie, "no significance gamma-ray emission") from FRB 20240114A were reported to have been observed by Fermi-LAT. On 4 May 2024, astronomers reported a redshift (ie, "a common redshift of z=0.1300+/-0002") for the FRB host galaxy, possibly a dwarf star-forming galaxy. Astronomers, on 15 May 2024, reported multiple burst detections of FRB 20240114A up to 6 GHz using the Effelsberg 100-m Radio Telescope. A gamma-ray flare associated with FRB 20240114A was reported on 25 May 2024. Announcement of five bursts from FRB 20240216A, a new repeating fast radio burst source, detected by Australian SKA Pathfinder (ASKAP) at position (J2000) of RA: 10:12:19.9 DEC: +14:02:26, was reported on 22 February 2024. FAST, on February 24, 2024, reported no detection, with several explanations, of FRB 20240216A. List of notable bursts All FRBs are cataloged at TNS. Repeating bursts, very polarized. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Geography] | [TOKENS: 6458] |
Contents Geography Geography (from Ancient Greek γεωγραφία geōgraphía; combining gê 'Earth' and gráphō 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding of Earth and its human and natural complexities—not merely where objects are, but also how they have changed and come to be. While geography is specific to Earth, many concepts can be applied more broadly to other celestial bodies in the field of planetary science. Geography has been called "a bridge between natural science and social science disciplines." The history of geography as a discipline spans cultures and millennia, being independently developed by multiple groups, and cross-pollinated by trade between these groups. Geography as a discipline dates back to the earliest attempts to understand the world spatially, with the earliest example of an attempted world map dating to the 9th century BC in ancient Babylon. Origins of many of the concepts in geography can be traced to Greek Eratosthenes of Cyrene, who may have coined the term "geographia" (c. 276 BC – c. 195/194 BC). The first recorded use of the word γεωγραφία was as the title of a book by Greek scholar Claudius Ptolemy (100 – 170 AD). During the Middle Ages, geography was influenced by Islamic scholars, like Muhammad al-Idrisi, producing detailed maps of the world. The Age of Discovery was influential in the development of geography, as European explorers mapped the New World. Modern developments include the development of geomatics and geographic information science. The core concepts of geography consistent between all approaches are a focus on space, place, time, and scale. Today, geography is an extremely broad discipline with multiple approaches and modalities. The main branches of geography are physical geography, human geography, and technical geography. Physical geography focuses on the natural environment, human geography focuses on how humans interact with the Earth, and technical geography focuses on the development of tools for understanding geography. Techniques employed can generally be broken down into quantitative and qualitative approaches, with many studies taking mixed-methods approaches. Common techniques include cartography, remote sensing, interviews, and surveying. Fundamentals Geography is a systematic study of the Earth (other celestial bodies are specified, such as "geography of Mars", or given another name, such as areography in the case of Mars, or selenography in the case of the Moon, or planetography for the general case), its features, and phenomena that take place on it. For something to fall into the domain of geography, it generally needs some sort of spatial component that can be placed on a map, such as coordinates, place names, or addresses. This has led to geography being associated with cartography and place names. Although many geographers are trained in toponymy and cartology, this is not their main preoccupation. Geographers study the Earth's spatial and temporal distribution of phenomena, processes, and features as well as the interaction of humans and their environment. Because space and place affect a variety of topics, such as economics, health, climate, plants, and animals, geography is highly interdisciplinary. The interdisciplinary nature of the geographical approach depends on an attentiveness to the relationship between physical and human phenomena and their spatial patterns. While narrowing down geography to a few key concepts is extremely challenging, and subject to tremendous debate within the discipline, several sources have approached the topic. The 1st edition of the book "Key Concepts in Geography" broke down this into chapters focusing on "Space," "Place," "Time," "Scale," and "Landscape." The 2nd edition of the book expanded on these key concepts by adding "Environmental systems," "Social Systems," "Nature," "Globalization," "Development," and "Risk," demonstrating how challenging narrowing the field can be. Another approach used extensively in teaching geography are the Five themes of geography established by "Guidelines for Geographic Education: Elementary and Secondary Schools," published jointly by the National Council for Geographic Education and the Association of American Geographers in 1984. These themes are Location, place, relationships within places (often summarized as Human-Environment Interaction), movement, and regions. The five themes of geography have shaped how American education approaches the topic in the years since. Just as all phenomena exist in time and thus have a history, they also exist in space and have a geography. — United States National Research Council, 1997 For something to exist in the realm of geography, it must be able to be described spatially. Thus, space is the most fundamental concept at the foundation of geography. The concept is so basic, that geographers often have difficulty defining exactly what it is. Absolute space is the exact site, or spatial coordinates, of objects, persons, places, or phenomena under investigation. We exist in space. Absolute space leads to the view of the world as a photograph, with everything frozen in place when the coordinates were recorded. Today, geographers are trained to recognize the world as a dynamic space where all processes interact and take place, rather than a static image on a map. Place is one of the most complex and important terms in geography. In human geography, place is the synthesis of the coordinates on the Earth's surface, the activity and use that occurs, has occurred, and will occur at the coordinates, and the meaning ascribed to the space by human individuals and groups. This can be extraordinarily complex, as different spaces may have different uses at different times and mean different things to different people. In physical geography, a place includes all of the physical phenomena that occur in space, including the lithosphere, atmosphere, hydrosphere, and biosphere. Places do not exist in a vacuum and instead have complex spatial relationships with each other, and place is concerned how a location is situated in relation to all other locations. As a discipline then, the term place in geography includes all spatial phenomena occurring at a location, the diverse uses and meanings humans ascribe to that location, and how that location impacts and is impacted by all other locations on Earth. In one of Yi-Fu Tuan's papers, he explains that in his view, geography is the study of Earth as a home for humanity, and thus place and the complex meaning behind the term is central to the discipline of geography. Time is usually thought to be within the domain of history, however, it is of significant concern in the discipline of geography. In physics, space and time are not separated, and are combined into the concept of spacetime. Geography is subject to the laws of physics, and in studying things that occur in space, time must be considered. Time in geography is more than just the historical record of events that occurred at various discrete coordinates; but also includes modeling the dynamic movement of people, organisms, and things through space. Time facilitates movement through space, ultimately allowing things to flow through a system. The amount of time an individual, or group of people, spends in a place will often shape their attachment and perspective to that place. Time constrains the possible paths that can be taken through space, given a starting point, possible routes, and rate of travel. Visualizing time over space is challenging in terms of cartography, and includes Space-Prism, advanced 3D geovisualizations, and animated maps. Scale in the context of a map is the ratio between a distance measured on the map and the corresponding distance as measured on the ground. This concept is fundamental to the discipline of geography, not just cartography, in that phenomena being investigated appear different depending on the scale used. Scale is the frame that geographers use to measure space, and ultimately to understand a place. During the quantitative revolution, geography shifted to an empirical law-making (nomothetic) approach. Several laws of geography have been proposed since then, most notably by Waldo Tobler and can be viewed as a product of the quantitative revolution. In general, some dispute the entire concept of laws in geography and the social sciences. These criticisms have been addressed by Tobler and others, such as Michael Frank Goodchild. However, this is an ongoing source of debate in geography and is unlikely to be resolved anytime soon. Several laws have been proposed, and Tobler's first law of geography is the most generally accepted in geography. Some have argued that geographic laws do not need to be numbered. The existence of a first invites a second, and many have proposed themselves as that. It has also been proposed that Tobler's first law of geography should be moved to the second and replaced with another. A few of the proposed laws of geography are below: Additionally, several variations or amendments to these laws exist within the literature, although not as well supported. For example, one paper proposed an amended version of Tobler's first law of geography, referred to in the text as the Tobler–von Thünen law, which states: "Everything is related to everything else, but near things are more related than distant things, as a consequence of accessibility." Sub-disciplines Geography is a branch of inquiry that focuses on spatial information on Earth. It is an extremely broad topic and can be broken down multiple ways. There have been several approaches to doing this spanning at least several centuries, including "four traditions of geography" and into distinct branches. The Four traditions of geography are often used to divide the different historical approach theories geographers have taken to the discipline. In contrast, geography's branches describe contemporary applied geographical approaches. Geography is an extremely broad field. Because of this, many view the various definitions of geography proposed over the decades as inadequate. To address this, William D. Pattison proposed the concept of the "Four traditions of Geography" in 1964. These traditions are the Spatial or Locational Tradition, the Man-Land or Human-Environment Interaction Tradition (sometimes referred to as Integrated geography), the Area Studies or Regional Tradition, and the Earth Science Tradition. These concepts are broad sets of geography philosophies bound together within the discipline. They are one of many ways geographers organize the major sets of thoughts and philosophies within the discipline. In another approach to the abovementioned four traditions, geography is organized into applied branches. The UNESCO Encyclopedia of Life Support Systems organizes geography into the three categories of human geography, physical geography, and technical geography. Some publications limit the number of branches to physical and human, describing them as the principal branches. Human geography largely focuses on the built environment and how humans create, view, manage, and influence space. Physical geography examines the natural environment and how organisms, climate, soil, water, and landforms produce and interact, studying spatial patterns in the natural environment, atmosphere, hydrosphere, biosphere, and geosphere. The difference between these approaches led to the development of integrated geography, which combines physical and human geography and concerns the interactions between the environment and humans. Technical geography involves studying and developing the tools and techniques used by geographers, such as remote sensing, cartography, and geographic information system. It is the newest of the branches, and often other terms are used in the literature to describe the emerging category. While human and physical geographers use the techniques employed by technical geographers, technical geography is more concerned with the fundamental spatial concepts and technologies than the nature of the data. It is therefore closely associated with the spatial tradition of geography while being applied to the other two major branches. These branches use similar geographic philosophies, concepts, and tools and often overlap significantly, so geographers rarely focus on just one of these topics, often using one as their primary focus and then incorporating data and methods from the other branches. Often, geographers are asked to describe what they do by individuals outside the discipline and are likely to identify closely with a specific branch, or sub-branch when describing themselves to lay people. Physical geography (or physiography) focuses on geography as an Earth science. It aims to understand the physical problems and the issues of lithosphere, hydrosphere, atmosphere, pedosphere, and global flora and fauna patterns (biosphere). Physical geography is the study of earth's seasons, climate, atmosphere, soil, streams, landforms, and oceans. Physical geographers will often work in identifying and monitoring the use of natural resources. Human geography (or anthropogeography) is a branch of geography that focuses on studying patterns and processes that shape human society. It encompasses the human, political, cultural, social, and economic aspects. In industry, human geographers often work in city planning, public health, or business analysis. Various approaches to the study of human geography have also arisen through time and include behavioral geography, culture theory, feminist geography, and geosophy. Human geographers study people and their communities, cultures, economies, and environmental interactions by studying their relations with and across space and place. Technical geography concerns studying and developing tools, techniques, and statistical methods employed to collect, analyze, use, and understand spatial data. Technical geography is the most recently recognized, and controversial, of the branches. Its use dates back to 1749, when a book published by Edward Cave organized the discipline into a section containing content such as cartographic techniques and globes. There are several other terms, often used interchangeably with technical geography to subdivide the discipline, including "techniques of geographic analysis," "Geographic Information Technology," "Geography method's and techniques," "Geographic Information Science," "geoinformatics," "geomatics," and "information geography". There are subtle differences to each concept and term; however, technical geography is one of the broadest, is consistent with the naming convention of the other two branches, has been in use since the 1700s, and has been used by the UNESCO Encyclopedia of Life Support Systems to divide geography into themes. As academic fields increasingly specialize in their nature, technical geography has emerged as a branch of geography specializing in geographic methods and thought. The emergence of technical geography has brought new relevance to the broad discipline of geography by serving as a set of unique methods for managing the interdisciplinary nature of the phenomena under investigation. A technical geographer might work as a GIS analyst, a GIS developer working to make new software tools, or create general reference maps incorporating human and natural features. Methods All geographic research and analysis start with asking the question "where," followed by "why there." Geographers start with the fundamental assumption set forth in Tobler's first law of geography, that "everything is related to everything else, but near things are more related than distant things." As spatial interrelationships are key to this synoptic science, maps are a key tool. Classical cartography has been joined by a more modern approach to geographical analysis, computer-based geographic information systems (GIS). In their study, geographers use four interrelated approaches: Quantitative methods in geography became particularly influential in the discipline during the quantitative revolution of the 1950s and 60s. These methods revitalized the discipline in many ways, allowing scientific testing of hypotheses and proposing scientific geographic theories and laws. The quantitative revolution heavily influenced and revitalized technical geography, and lead to the development of the subfield of quantitative geography. Cartography is the art, science, and technology of making maps. Cartographers study the Earth's surface representation with abstract symbols (map making). Although other subdisciplines of geography rely on maps for presenting their analyses, the actual making of maps is abstract enough to be regarded separately. Cartography has grown from a collection of drafting techniques into an actual science. Cartographers must learn cognitive psychology and ergonomics to understand which symbols convey information about the Earth most effectively and behavioural psychology to induce the readers of their maps to act on the information. They must learn geodesy and fairly advanced mathematics to understand how the shape of the Earth affects the distortion of map symbols projected onto a flat surface for viewing. It can be said, without much controversy, that cartography is the seed from which the larger field of geography grew. Geographic information systems (GIS) deal with storing information about the Earth for automatic retrieval by a computer in an accurate manner appropriate to the information's purpose. In addition to all of the other subdisciplines of geography, GIS specialists must understand computer science and database systems. GIS has revolutionized the field of cartography: nearly all mapmaking is now done with the assistance of some form of GIS software. The science of using GIS software and GIS techniques to represent, analyse, and predict the spatial relationships is called geographic information science (GISc). Remote sensing is the art, science, and technology of obtaining information about Earth's features from measurements made at a distance. Remotely sensed data can be either passive, such as traditional photography, or active, such as LiDAR. A variety of platforms can be used for remote sensing, including satellite imagery, aerial photography (including consumer drones), and data obtained from hand-held sensors. Products from remote sensing include Digital elevation model and cartographic base maps. Geographers increasingly use remotely sensed data to obtain information about the Earth's land surface, ocean, and atmosphere, because it: (a) supplies objective information at a variety of spatial scales (local to global), (b) provides a synoptic view of the area of interest, (c) allows access to distant and inaccessible sites, (d) provides spectral information outside the visible portion of the electromagnetic spectrum, and (e) facilitates studies of how features/areas change over time. Remotely sensed data may be analyzed independently or in conjunction with other digital data layers (e.g., in a geographic information system). Remote sensing aids in land use, land cover (LULC) mapping, by helping to determine both what is naturally occurring on a piece of land and what human activities are taking place on it. Geostatistics deal with quantitative data analysis, specifically the application of a statistical methodology to the exploration of geographic phenomena. Geostatistics is used extensively in a variety of fields, including hydrology, geology, petroleum exploration, weather analysis, urban planning, logistics, and epidemiology. The mathematical basis for geostatistics derives from cluster analysis, linear discriminant analysis and non-parametric statistical tests, and a variety of other subjects. Applications of geostatistics rely heavily on geographic information systems, particularly for the interpolation (estimate) of unmeasured points. Geographers are making notable contributions to the method of quantitative techniques. Qualitative methods in geography are descriptive rather than numerical or statistical in nature. They add context to concepts, and explore human concepts like beliefs and perspective that are difficult or impossible to quantify. Human geography is much more likely to employ qualitative methods than physical geography. Increasingly, technical geographers are attempting to employ GIS methods to qualitative datasets. Qualitative cartography employs many of the same software and techniques as quantitative cartography. It may be employed to inform on map practices, or to visualize perspectives and ideas that are not strictly quantitative in nature. An example of a form of qualitative cartography is a Chorochromatic map of nominal data, such as land cover or dominant language group in an area. Another example is a deep map, or maps that combine geography and storytelling to produce a product with greater information than a two-dimensional image of places, names, and topography. This approach offers more inclusive strategies than more traditional cartographic approaches for connecting the complex layers that makeup places. Ethnographical research techniques are used by human geographers. In cultural geography, there is a tradition of employing qualitative research techniques, also used in anthropology and sociology. Participant observation and in-depth interviews provide human geographers with qualitative data. Geopoetics is an interdisciplinary approach that combines geography and poetry to explore the interconnectedness between humans, space, place, and the environment. Geopoetics is employed as a mixed methods tool to explain the implications of geographic research. It is often employed to address and communicate the implications of complex topics, such as the anthropocene. Geographers employ interviews to gather data and acquire valuable understandings from individuals or groups regarding their encounters, outlooks, and opinions concerning spatial phenomena. Interviews can be carried out through various mediums, including face-to-face interactions, phone conversations, online platforms, or written exchanges. Geographers typically adopt a structured or semi-structured approach during interviews involving specific questions or discussion points when utilized for research purposes. These questions are designed to extract focused information about the research topic while being flexible enough to allow participants to express their experiences and viewpoints, such as through open-ended questions. Origin and history The concept of geography is present in all cultures, and therefore the history of the discipline is a series of competing narratives, with concepts emerging at various points across space and time. The oldest known world maps date back to ancient Babylon from the 9th century BC. The best known Babylonian world map, however, is the Imago Mundi of 600 BC. The map as reconstructed by Eckhard Unger shows Babylon on the Euphrates, surrounded by a circular landmass showing Assyria, Urartu, and several cities, in turn surrounded by a "bitter river" (Oceanus), with seven islands arranged around it so as to form a seven-pointed star. The accompanying text mentions seven outer regions beyond the encircling ocean. The descriptions of five of them have survived. In contrast to the Imago Mundi, an earlier Babylonian world map dating back to the 9th century BC depicted Babylon as being further north from the center of the world, though it is not certain what that center was supposed to represent. The ideas of Anaximander (c. 610–545 BC): considered by later Greek writers to be the true founder of geography, come to us through fragments quoted by his successors. Anaximander is credited with the invention of the gnomon, the simple, yet efficient Greek instrument that allowed the early measurement of latitude. Thales is also credited with the prediction of eclipses. The foundations of geography can be traced to ancient cultures, such as the ancient, medieval, and early modern Chinese. The Greeks, who were the first to explore geography as both art and science, achieved this through Cartography, Philosophy, and Literature, or through Mathematics. There is some debate about who was the first person to assert that the Earth is spherical in shape, with the credit going either to Parmenides or Pythagoras. Anaxagoras was able to demonstrate that the profile of the Earth was circular by explaining eclipses. However, he still believed that the Earth was a flat disk, as did many of his contemporaries. One of the first estimates of the radius of the Earth was made by Eratosthenes. The first rigorous system of latitude and longitude lines is credited to Hipparchus. He employed a sexagesimal system that was derived from Babylonian mathematics. The meridians were subdivided into 360°, with each degree further subdivided into 60 (minutes). To measure the longitude at different locations on Earth, he suggested using eclipses to determine the relative difference in time. The extensive mapping by the Romans as they explored new lands would later provide a high level of information for Ptolemy to construct detailed atlases. He extended the work of Hipparchus, using a grid system on his maps and adopting a length of 56.5 miles for a degree. From the 3rd century onwards, Chinese methods of geographical study and writing of geographical literature became much more comprehensive than what was found in Europe at the time (until the 13th century). Chinese geographers such as Liu An, Pei Xiu, Jia Dan, Shen Kuo, Fan Chengda, Zhou Daguan, and Xu Xiake wrote important treatises, yet by the 17th century advanced ideas and methods of Western-style geography were adopted in China.[citation needed] During the Middle Ages, the fall of the Roman empire led to a shift in the evolution of geography from Europe to the Islamic world. Muslim geographers such as Muhammad al-Idrisi produced detailed world maps (such as Tabula Rogeriana), while other geographers such as Yaqut al-Hamawi, Abu Rayhan Biruni, Ibn Battuta, and Ibn Khaldun provided detailed accounts of their journeys and the geography of the regions they visited. Turkish geographer Mahmud al-Kashgari drew a world map on a linguistic basis, and later so did Piri Reis (Piri Reis map). Further, Islamic scholars translated and interpreted the earlier works of the Romans and the Greeks and established the House of Wisdom in Baghdad for this purpose. Abū Zayd al-Balkhī, originally from Balkh, founded the "Balkhī school" of terrestrial mapping in Baghdad. Suhrāb, a late tenth century Muslim geographer accompanied a book of geographical coordinates, with instructions for making a rectangular world map with equirectangular projection or cylindrical equidistant projection. Abu Rayhan Biruni (976–1048) first described a polar equi-azimuthal equidistant projection of the celestial sphere. He was regarded as the most skilled when it came to mapping cities and measuring the distances between them, which he did for many cities in the Middle East and the Indian subcontinent. He often combined astronomical readings and mathematical equations to develop methods of pin-pointing locations by recording degrees of latitude and longitude. He also developed similar techniques when it came to measuring the heights of mountains, depths of the valleys, and expanse of the horizon. He also discussed human geography and the planetary habitability of the Earth. He also calculated the latitude of Kath, Khwarezm, using the maximum altitude of the Sun, and solved a complex geodesic equation to accurately compute the Earth's circumference, which was close to modern values of the Earth's circumference. His estimate of 6,339.9 km for the Earth radius was only 16.8 km less than the modern value of 6,356.7 km. In contrast to his predecessors, who measured the Earth's circumference by sighting the Sun simultaneously from two different locations, al-Biruni developed a new method of using trigonometric calculations based on the angle between a plain and mountain top, which yielded more accurate measurements of the Earth's circumference, and made it possible for it to be measured by a single person from a single location. The European Age of Discovery during the 16th and the 17th centuries, where many new lands were discovered and accounts by European explorers such as Christopher Columbus, Marco Polo, and James Cook revived a desire for both accurate geographic detail and more solid theoretical foundations in Europe. In 1650, the first edition of the Geographia Generalis was published by Bernhardus Varenius, which was later edited and republished by others including Isaac Newton. This textbook sought to integrate new scientific discoveries and principles into classical geography and approach the discipline like the other sciences emerging, and is seen by some as the division between ancient and modern geography in the West. The Geographia Generalis contained both theoretical background and practical applications related to ship navigation. The remaining problem facing both explorers and geographers was finding the latitude and longitude of a geographic location. While the problem of latitude was solved long ago, but that of longitude remained; agreeing on what zero meridians should be was only part of the problem. It was left to John Harrison to solve it by inventing the chronometer H-4 in 1760, and later in 1884 for the International Meridian Conference to adopt by convention the Greenwich meridian as zero meridians. The 18th and 19th centuries were the times when geography became recognized as a discrete academic discipline, and became part of a typical university curriculum in Europe (especially Paris and Berlin). The development of many geographic societies also occurred during the 19th century, with the foundations of the Société de Géographie in 1821, the Royal Geographical Society in 1830, Russian Geographical Society in 1845, American Geographical Society in 1851, the Royal Danish Geographical Society in 1876 and the National Geographic Society in 1888. The influence of Immanuel Kant, Alexander von Humboldt, Carl Ritter, and Paul Vidal de la Blache can be seen as a major turning point in geography from philosophy to an academic subject. Geographers such as Richard Hartshorne and Joseph Kerski have regarded both Humboldt and Ritter as the founders of modern geography, as Humboldt and Ritter were the first to establish geography as an independent scientific discipline. Over the past two centuries, the advancements in technology with computers have led to the development of geomatics and new practices such as participant observation and geostatistics being incorporated into geography's portfolio of tools. In the West during the 20th century, the discipline of geography went through four major phases: environmental determinism, regional geography, the quantitative revolution, and critical geography. The strong interdisciplinary links between geography and the sciences of geology and botany, as well as economics, sociology, and demographics, have also grown greatly, especially as a result of earth system science that seeks to understand the world in a holistic view. New concepts and philosophies have emerged from the rapid advancement of computers, quantitative methods, and interdisciplinary approaches. The 1962 book Theoretical Geography by William Bunge, which argued for a nomothetic approach to geography and that from a purely spatial perspective there was no real difference between human and physical geography, has been described by Kevin R. Cox as "perhaps the seminal text of the spatial-quantitative revolution." In 1970, Waldo Tobler proposed the first law of geography, "everything is related to everything else, but near things are more related than distant things." This law summarizes the first assumption geographers make about the world. Related fields The discipline of geography, especially physical geography, and geology have significant overlap. In the past, the two have often shared academic departments at universities, a point that has led to conflict over resources. Both disciplines do seek to understand the rocks on the Earth's surface and the processes that change them over time. Geology employs many of the tools and techniques of technical geographers, such as GIS and remote sensing to aid in geological mapping. However, geology includes research that goes beyond the spatial component, such as the chemical analysis of rocks and biogeochemistry. The discipline of History has significant overlap with geography, especially human geography. Like geology, history and geography have shared university departments. Geography provides the spatial context within which historical events unfold. The physical geographic features of a region, such as its landforms, climate, and resources, shape human settlements, trade routes, and economic activities, which in turn influence the course of historical events. Thus, a historian must have a strong foundation in geography. Historians employ the techniques of technical geographers to create historical atlases and maps. While the discipline of geography is normally concerned with the Earth, the term can also be informally used to describe the study of other worlds, such as the planets of the Solar System and even beyond. The study of systems larger than the Earth itself usually forms part of Astronomy or Cosmology, while the study of other planets is usually called planetary science. Alternative terms such as areography (geography of Mars) have been employed to describe the study of other celestial objects. Ultimately, geography may be considered a subdiscipline within planetary science, and planetary science link geography with fields like astronomy and physics. See also References External links |
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