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Divinity
Divinity or the divine are things that are either related to, devoted to, or proceeding from a god or God. What is or is not divine may be loosely defined, as it is used by different belief systems.
The root of the word "divine" is literally "godly" (from the Latin "deus", cf. "Dyaus", closely related to Greek "zeus", "div" in Persian and "deva" in Sanskrit), but the use varies significantly depending on which deity is being discussed.
For specific related academic terms, see Divinity (academic discipline), or Divine (Anglican).
Divinity as a quality has two distinct usages:
Overlap occurs between these usages because deities or godly entities are often identical with or identified by the powers and forces that are credited to them — in many cases a deity is merely a power or force personified — and these powers and forces may then be extended or granted to mortal individuals. For instance, Jehovah is closely associated with storms and thunder throughout much of the Old Testament. He is said to speak in thunder, and thunder is seen as a token of his anger. This power was then extended to prophets like Moses and Samuel, who caused thunderous storms to rain down on their enemies. (See and 1 Samuel 12:18.)
Divinity always carries connotations of goodness, beauty, beneficence, justice, and other positive, pro-social attributes. In monotheistic faiths there is an equivalent cohort of malefic supernatural beings and powers, such as demons, devils, afreet, etc., which are not conventionally referred to as divine; "demonic" is often used instead. Pantheistic and polytheistic faiths make no such distinction; gods and other beings of transcendent power often have complex, ignoble, or even irrational motivations for their acts. Note that while the terms "demon" and "demonic" are used in monotheistic faiths as antonyms to "divine", they are in fact derived from the Greek word "daimón" (δαίμων), which itself translates as "divinity".
There are three distinct usages of "divinity" and "divine" in religious discourse:
In monotheistic faiths, the word "divinity" is often used to refer to the singular God central to that faith. Often the word takes the definite article and is capitalized — ""the Divinity"" — as though it were a proper name or definitive honorific.
"Divine" — capitalized — may be used as an adjective to refer to the manifestations of such a Divinity or its powers: e.g. "basking in the Divine presence..."
The terms "divinity" and "divine" — uncapitalized, and lacking the definite article — are sometimes used as to denote 'god(s) or certain other beings and entities which fall short of absolute Godhood but lie outside the human realm. These include (by no means an exhaustive list):
As previously noted, divinities are closely related to the transcendent force(s) or power(s) credited to them, so much so that in some cases the powers or forces may themselves be invoked independently. This leads to the second usage of the word "divine" (and a less common usage of "divinity"): to refer to the operation of transcendent power in the world.
In its most direct form, the operation of transcendent power implies some form of divine intervention. For pan- and polytheistic faiths this usually implies the direct action of one god or another on the course of human events. In Greek legend, for instance, it was Poseidon (god of the sea) who raised the storms that blew Odysseus's craft off course on his return journey, and Japanese tradition holds that a god-sent wind saved them from Mongol invasion. Prayers or propitiations are often offered to specific gods of pantheisms to garner favorable interventions in particular enterprises: e.g. safe journeys, success in war, or a season of bountiful crops. Many faiths around the world — from Japanese Shinto and Chinese traditional religion, to certain African practices and the faiths derived from those in the Caribbean, to Native American beliefs — hold that ancestral or household deities offer daily protection and blessings. In monotheistic religions, divine intervention may take very direct forms: miracles, visions, or intercessions by blessed figures.
Transcendent force or power may also operate through more subtle and indirect paths. Monotheistic faiths generally support some version of divine providence, which acknowledges that the divinity of the faith has a profound but unknowable plan always unfolding in the world. Unforeseeable, overwhelming, or seemingly unjust events are often thrown on 'the will of the Divine', in deferences like the Muslim "inshallah" ('as God wills it') and Christian 'God works in mysterious ways'. Often such faiths hold out the possibility of divine retribution as well, where the divinity will unexpectedly bring evil-doers to justice through the conventional workings of the world; from the subtle redressing of minor personal wrongs, to such large-scale havoc as the destruction of Sodom and Gomorrah or the biblical Great Flood. Other faiths are even more subtle: the doctrine of "karma" shared by Buddhism and Hinduism is a divine law similar to divine retribution but without the connotation of punishment: our acts, good or bad, intentional or unintentional, reflect back on us as part of the natural working of the universe. Philosophical Taoism also proposes a transcendent operant principle — transliterated in English as "tao" or "dao", meaning 'the way' — which is neither an entity or a being per se, but reflects the natural ongoing process of the world. Modern western mysticism and new age philosophy often use the term 'the Divine' as a noun in this latter sense: a non-specific principle or being that gives rise to the world, and acts as the source or wellspring of life. In these latter cases the faiths do not promote deference, as happens in monotheisms; rather each suggests a path of action that will bring the practitioner into conformance with the divine law: "ahimsa" — 'no harm' — for Buddhist and Hindu faiths; "de" or "te" — 'virtuous action' — in Taoism; and any of numerous practices of peace and love in new age thinking.
In the third usage, extensions of divinity and divine power are credited to living, mortal individuals. Political leaders are known to have claimed actual divinity in certain early societies — the ancient Egyptian Pharaohs being the premier case — taking a role as objects of worship and being credited with superhuman status and powers. More commonly, and more pertinent to recent history, leaders merely claim some form of divine mandate, suggesting that their rule is in accordance with the will of God. The doctrine of the divine right of kings was introduced as late as the 17th century, proposing that kings rule by divine decree; Japanese Emperors ruled by divine mandate until the inception of the Japanese constitution after World War II.
Less politically, most faiths have any number of people that are believed to have been touched by divine forces: saints, prophets, heroes, oracles, martyrs, and enlightened beings, among others. Saint Francis of Assisi, in Catholicism, is said to have received instruction directly from God and it is believed that he grants plenary indulgence to all who confess their sins and visit his chapel on the appropriate day. In Greek mythology, Achilles' mother bathed him in the river Styx to give him immortality, and Hercules — as the son of Zeus — inherited near-godly powers. In religious Taoism, Lao Tsu is venerated as a saint with his own powers. Various individuals in the Buddhist faith, beginning with Siddhartha, are considered to be enlightened, and in religious forms of Buddhism they are credited with divine powers. Christ in the Bible is said to be God's Son and is said to have performed divine miracles.
In general, mortals with divine qualities are carefully distinguished from the deity or deities in their religion's main pantheon. Even the Christian faith, which generally holds Christ to be identical to God, distinguishes between God the Father and Christ the begotten Son. There are, however, certain esoteric and mystical schools of thought, present in many faiths — Sufis in Islam, Gnostics in Christianity, Advaitan Hindus, Zen Buddhists, as well as several non-specific perspectives developed in new age philosophy — which hold that all humans are in essence divine, or unified with the Divine in a non-trivial way. Such divinity, in these faiths, would express itself naturally if it were not obscured by the social and physical worlds we live in; it needs to be brought to the fore through appropriate spiritual practices.
In traditional Christian theology, divinity is the state or quality of being divine, and can denote Godly nature or character. In Hebrew, the terms would usually be "el", "elohim", and in Greek usually "theos", or "theias". The divinity in the Bible is considered the Godhead itself, or God in general. Or it may have reference to a deity. Even angels in the Psalms are considered divine or "elohim", as spirit beings, in God's form.
In the New Testament the Greek word θεῖον ("theion") in the Douay Version, is translated as "divinity". Examples are below:
The word translated as either "deity", "Godhead", or "divinity" in the Greek New Testament is also the Greek word θεότητος ("theotētos"), and the one verse that contains it is this:
Colossians 2:9
The word "divine" in the New Testament is the Greek word θείας ("theias"), and is the adjective form of "divinity". Biblical examples from the King James Bible are below:
The most prominent conception of divine entities in The Church of Jesus Christ of Latter-day Saints (LDS Church) is the Godhead, a divine council of three distinct beings: Elohim (the Father), Jehovah (the Son, or Jesus), and the Holy Spirit. Joseph Smith described a nontrinitarian Godhead, with God the Father and Jesus Christ each having individual physical bodies, and the Holy Spirit as a distinct personage with a spirit body. Smith also introduced the existence of a Heavenly Mother in the King Follett Discourse, but very little is acknowledged or known beyond her existence.
Mormons hold a belief in the divine potential of humanity; Smith taught a form of divinization where mortal men and women can become like god through salvation and exaltation. Lorenzo Snow succinctly summarized this using a couplet, which is often repeated within the LDS Church: "As man now is, God once was: As God now is, man may be." | https://en.wikipedia.org/wiki?curid=8363 |
Depth of field
For many cameras, depth of field (DOF) is the distance between the nearest and the farthest objects that are in acceptably sharp focus in an image. The depth of field can be calculated based on focal length, distance to subject, the acceptable circle of confusion size, and aperture. A particular depth of field may be chosen for technical or artistic purposes. Limitations of depth of field can sometimes be overcome with various techniques/equipment.
For Cameras that can only focus on one object distance at a time, Depth of field is the distance between the nearest and the farthest objects that are in acceptably sharp focus. "Acceptably sharp focus" is defined using a property called the "circle of confusion".
The depth of field can be determined by focal length, distance to subject, the acceptable circle of confusion size, and aperture. The approximate depth of field can be given by:
for a given circle of confusion (c), focal length (f), f-number (N), and distance to subject (u).
As distance or the size of the acceptable circle of confusion increases, the depth of field increases; however, increasing the size of the aperture or increasing the focal length reduces the depth of field. Depth of Field changes linearly with F-number and circle of confusion, but changes in proportional to the square of the focal length and the distance to the subject. As a result, photos taken at extremely close range have a proportionally much smaller depth of field.
Sensor size affects DOF in counterintuitive ways. Because the circle of confusion is directly tied to the sensor size, decreasing the size of the sensor while holding focal length and aperture constant will "decrease" the depth of field (by the crop factor). The resulting image however will have a different field of view. If the focal length is altered to maintain the field of view, the change in focal length will counter the decrease of DOF from the smaller sensor and "increase" the depth of field (also by the crop factor).
For a given subject framing and camera position, the DOF is controlled by the lens aperture diameter, which is usually specified as the f-number (the ratio of lens focal length to aperture diameter). Reducing the aperture diameter (increasing the f-number) increases the DOF because only the light travelling at shallower angles passes through the aperture. Because the angles are shallow, the light rays are within the acceptable circle of confusion for a greater distance.
Motion pictures make only limited use of this control; to produce a consistent image quality from shot to shot, cinematographers usually choose a single aperture setting for interiors and another for exteriors, and adjust exposure through the use of camera filters or light levels. Aperture settings are adjusted more frequently in still photography, where variations in depth of field are used to produce a variety of special effects.
Precise focus is only possible at an exact distance from the lens; at that distance, a point object will produce a point image. Otherwise, a point object will produce a blur spot shaped like the aperture, typically and approximately a circle. When this circular spot is sufficiently small, it is visually indistinguishable from a point, and appears to be in focus. The diameter of the largest circle that is indistinguishable from a point is known as the acceptable circle of confusion, or informally, simply as the circle of confusion. Points that produce a blur spot smaller than this acceptable circle of confusion are considered acceptably sharp.
The acceptable circle of confusion depends on how the final image will be used. It is generally accepted to be 0.25 mm for an image viewed from 25 cm away.
For 35 mm motion pictures, the image area on the film is roughly 22 mm by 16 mm. The limit of tolerable error was traditionally set at 0.05 mm (0.002 in) diameter, while for 16 mm film, where the size is about half as large, the tolerance is stricter, 0.025 mm (0.001 in). More modern practice for 35 mm productions set the circle of confusion limit at 0.025 mm (0.001 in).
The term "camera movements" refers to swivel (swing and tilt, in modern terminology) and shift adjustments of the lens holder and the film holder. These features have been in use since the 1800s and are still in use today on view cameras, technical cameras, cameras with tilt/shift or perspective control lenses, etc. Swiveling the lens or sensor causes the plane of focus (POF) to swivel, and also causes the field of acceptable focus to swivel with the POF; and depending on the DOF criteria, to also change the shape of the field of acceptable focus. While calculations for DOF of cameras with swivel set to zero have been discussed, formulated, and documented since before the 1940s, documenting calculations for cameras with non-zero swivel seem to have begun in 1990.
More so than in the case of the zero swivel camera, there are various methods to form criteria and set up calculations for DOF when swivel is non-zero. There is a gradual reduction of clarity in objects as they move away from the POF, and at some virtual flat or curved surface the reduced clarity becomes unacceptable. Some photographers do calculations or use tables, some use markings on their equipment, some judge by previewing the image.
When the POF is rotated, the near and far limits of DOF may be thought of as wedge-shaped, with the apex of the wedge nearest the camera; or they may be thought of as parallel to the POF.
Traditional depth-of-field formulas can be hard to use in practice. As an alternative, the same effective calculation can be done without regard to the focal length and f-number. Moritz von Rohr and later Merklinger observe that the effective absolute aperture diameter can be used for similar formula in certain circumstances.
Moreover, traditional depth-of-field formulas assume equal acceptable circles of confusion for near and far objects. Merklinger suggested that distant objects often need to be much sharper to be clearly recognizable, whereas closer objects, being larger on the film, do not need to be so sharp. The loss of detail in distant objects may be particularly noticeable with extreme enlargements. Achieving this additional sharpness in distant objects usually requires focusing beyond the hyperfocal distance, sometimes almost at infinity. For example, if photographing a cityscape with a traffic bollard in the foreground, this approach, termed the "object field method" by Merklinger, would recommend focusing very close to infinity, and stopping down to make the bollard sharp enough. With this approach, foreground objects cannot always be made perfectly sharp, but the loss of sharpness in near objects may be acceptable if recognizability of distant objects is paramount.
Other authors such as Ansel Adams have taken the opposite position, maintaining that slight unsharpness in foreground objects is usually more disturbing than slight unsharpness in distant parts of a scene.
Some methods and equipment allow altering the apparent DOF, and some even allow the DOF to be determined after the image is made. For example, Focus stacking combines multiple images focused on different planes, resulting in an image with a greater (or less, if so desired) apparent depth of field than any of the individual source images. Similarly, in order to reconstruct the 3-dimensional shape of an object, a depth map can be generated from multiple photographs with different depths of field. Xiong and Shafer concluded, in part, "...the improvements on precisions of focus ranging and defocus ranging can lead to efficient shape recovery methods."
Another approach is focus sweep. The focal plane is swept across the entire relevant range during a single exposure. This creates a blurred image, but with a convolution kernel that is nearly independent of object depth, so that the blur is almost entirely removed after computational deconvolution. This has the added benefit of dramatically reducing motion blur.
Other technologies use a combination of lens design and post-processing: Wavefront coding is a method by which controlled aberrations are added to the optical system so that the focus and depth of field can be improved later in the process.
The lens design can be changed even more: in colour apodization the lens is modified such that each colour channel has a different lens aperture. For example, the red channel may be "f"/2.4, green may be "f"/2.4, whilst the blue channel may be "f"/5.6. Therefore, the blue channel will have a greater depth of field than the other colours. The image processing identifies blurred regions in the red and green channels and in these regions copies the sharper edge data from the blue channel. The result is an image that combines the best features from the different "f"-numbers.
At the extreme, a plenoptic camera captures 4D light field information about a scene, so the focus and depth of field can be altered after the photo is taken.
Diffraction causes images to lose sharpness at high F-numbers, and hence limits the potential depth of field. In general photography this is rarely an issue; because large f-numbers typically require long exposure times, motion blur may cause greater loss of sharpness than the loss from diffraction. However, diffraction is a greater issue in close-up photography, and the tradeoff between DOF and overall sharpness can become quite noticeable as photographers are trying to maximise depth of field with very small apertures.
Hansma and Peterson have discussed determining the combined effects of defocus and diffraction using a root-square combination of the individual blur spots. Hansma's approach determines the f-number that will give the maximum possible sharpness; Peterson's approach determines the minimum f-number that will give the desired sharpness in the final image, and yields a maximum depth of field for which the desired sharpness can be achieved. In combination, the two methods can be regarded as giving a maximum and minimum f-number for a given situation, with the photographer free to choose any value within the range, as conditions (e.g., potential motion blur) permit. Gibson gives a similar discussion, additionally considering blurring effects of camera lens aberrations, enlarging lens diffraction and aberrations, the negative emulsion, and the printing paper. Couzin gave a formula essentially the same as Hansma's for optimal "f"-number, but did not discuss its derivation.
Hopkins, Stokseth, and Williams and Becklund have discussed the combined effects using the modulation transfer function.
Many lenses include scales that indicate the DOF for a given focus distance and f-number; the 35 mm lens in the image is typical. That lens includes distance scales in feet and meters; when a marked distance is set opposite the large white index mark, the focus is set to that distance. The DOF scale below the distance scales includes markings on either side of the index that correspond to f-numbers. When the lens is set to a given f-number, the DOF extends between the distances that align with the f-number markings.
Photographers can use the lens scales to work backwards from the desired depth of field to find the necessary focus distance and aperture. For the 35 mm lens shown, if it were desired for the DOF to extend from 1 m to 2 m, focus would be set so that index mark was centered between the marks for those distances, and the aperture would be set to f/11.
On a view camera, the focus and f-number can be obtained by measuring the depth of field and performing simple calculations. Some view cameras include DOF calculators that indicate focus and f-number without the need for any calculations by the photographer.
The DOF beyond the subject is always greater than the DOF in front of the subject. When the subject is at the hyperfocal distance or beyond, the far DOF is infinite, so the ratio is 1:∞; as the subject distance decreases, near:far DOF ratio increases, approaching unity at high magnification. For large apertures at typical portrait distances, the ratio is still close to 1:1.
This section covers some additional formula for evaluating depth of field; however they are all subject to significant simplifying assumptions: for example, they assume paraxial (Gaussian). They are suitable for practical photography, lens designers would use significantly more complex ones.
For given near and far DOF limits formula_2 and formula_3, the required f-number is smallest when focus is set to
the harmonic mean of the near and far distances. In practice, this is equivalent to the arithmetic mean for shallow depths of field. Sometimes, view camera users refer to the difference formula_5 as the "focus spread".
If a subject is at distance formula_6 and the foreground or background is at distance formula_7, let the distance between the subject and the foreground or background be indicated by
The blur disk diameter formula_9 of a detail at distance formula_10 from the subject can be expressed as a function of the subject magnification formula_11, focal length formula_12, f-number formula_13, or alternatively the aperture formula_14, according to
The minus sign applies to a foreground object, and the plus sign applies to a background object.
The blur increases with the distance from the subject; when formula_9 is less than the circle of confusion, the detail is within the depth of field. | https://en.wikipedia.org/wiki?curid=8367 |
Dumnonii
The Dumnonii or Dumnones were a British tribe who inhabited Dumnonia, the area now known as Devon and Cornwall (and some areas of present-day Dorset and Somerset) in the further parts of the South West peninsula of Britain, from at least the Iron Age up to the early Saxon period. They were bordered to the east by the Durotriges tribe.
William Camden, in his 1607 edition of "Britannia", describes Cornwall and Devon as being two parts of the same 'country' which:
Camden had learnt some Welsh during the course of his studies and it would appear that he is the origin of the interpretation of Dumnonii as "deep valley dwellers" from his understanding of the Welsh of his time. John Rhys later theorized that the tribal name was derived from the name of a goddess, "Domnu", probably meaning "the goddess of the deep". The proto-Celtic root *dubno- or *dumno- meaning "the deep" or "the earth" (or alternatively meaning "dark" or "gloomy") appears in personal names such as Dumnorix and Dubnovellaunus. Another group with a similar name but with no known links were the Fir Domnann of Connacht.
The Roman name of the town of Exeter, "Isca Dumnoniorum" ("Isca of the Dumnonii"), contains the root "*iska-" "water" for "Water of the Dumnonii". The Latin name suggests that the city was already an "oppidum", or walled town, on the banks on the River Exe before the foundation of the Roman city, in about AD 50. The Dumnonii gave their name to the English county of Devon, and their name is represented in Britain's two extant Brythonic languages as "Dewnans" in Cornish and "Dyfnaint" in Welsh. Amédée Thierry ("Histoire des Gaulois", 1828), one of the inventors of the "historic race" of Gauls, could confidently equate them with the Cornish ("les Cornouailles").
Victorian historians often referred to the tribe as the Damnonii, which is also the name of another people from lowland Scotland, although there are no known links between the two populations.
The people of Dumnonia spoke a Southwestern Brythonic dialect similar to the forerunner of more recent Cornish and Breton. Irish immigrants, the Déisi, are evidenced by the Ogham-inscribed stones they have left behind, confirmed and supplemented by toponymical studies. The stones are sometimes inscribed in Latin, sometimes in both scripts. Tristram Risdon suggested the continuance of a Brythonic dialect in the South Hams, Devon, as late as the 14th century, in addition to its use in Cornwall.
Ptolemy's 2nd century "Geography" places the Dumnonii to the west of the Durotriges. The name "purocoronavium" that appears in the Ravenna Cosmography implies the existence of a sub-tribe called the Cornavii or Cornovii, perhaps the ancestors of the Cornish people.
Gaius Iulius Solinus, probably in the 3rd century, remarks: "This turbid strait also divides the island Silura from the shore which is held by the Dumnonii, a British tribe. The men of this island even now preserve an old custom: they do not use coins. They give and accept, obtaining the necessities of life by exchange rather than by money. They reverence gods, and the men and women equally declare knowledge of the future."
In the sub-Roman period a Brythonic kingdom called Dumnonia emerged, covering the entire peninsula, although it is believed by some to have effectively been a collection of sub-kingdoms.
A kingdom of Domnonée (and of Cornouaille alongside) was established in the province of Armorica directly across the English Channel, and has apparent links with the British population, suggesting an ancient connection of peoples along the western Atlantic seaboard.
The Latin name for Exeter is Isca Dumnoniorum ("Water of the Dumnonii"). This oppidum (a Latin term meaning an important town) on the banks of I River Exe certainly existed prior to the foundation of the Roman city in about AD 50. "Isca" is derived from the Brythonic word for flowing water, which was given to the River Exe. This is reflected in the Welsh name for Exeter: "Caerwysg" meaning "fortified settlement on the river Uisc".
Isca Dumnoniorum originated with a settlement that developed around the Roman fortress of the Legio II Augusta and is one of the four "poleis" (cities) attributed to the tribe by Ptolemy. It is also listed in two routes of the late 2nd century Antonine Itinerary.
A legionary bath-house was built inside the fortress sometime between 55 and 60 and underwent renovation shortly afterwards (c. 60-65) but by c. 68 (perhaps even 66) the legion had transferred to a newer fortress at Gloucester. This saw the dismantling of the Isca fortress, and the site was then abandoned. Around AD 75, work on the "civitas forum" and "basilica" had commenced on the site of the former "principia" and by the late 2nd century the "civitas" walls had been completed. They were 3 metres thick and 6 metres high and enclosed exactly the same area as the earlier fortress. However, by the late 4th century the "civitas" was in decline.
As well as Isca Dumnoniorum, Ptolemy's 2nd century "Geography" names three other towns:
The Ravenna Cosmography includes the last two names (in slightly different forms, as "Tamaris" and "Uxelis"), and adds several more names which may be settlements in the territory. These include:
Other Romano-British sites in Dumnonia include:
New settlements continued to be built throughout the Roman period, including sites at Chysauster and Trevelgue Head. The style is native in form with no Romanised features. Near Padstow, a site of some importance that was inhabited from the late Bronze/early Iron Age to the mid 6th century now lies buried under the sands on the opposite side of the Camel estuary near St. Enodoc's Church, and may have been a western coastal equivalent of a Saxon Shore Fort. Byzantine and African pottery has been discovered at the site. At Magor Farm in Illogan, near Camborne, an archaeological site has been identified as being a villa.
The Dumnonii are thought to have occupied relatively isolated territory in Cornwall, Devon, Somerset and possibly part of Dorset. Their cultural connections, as expressed in their ceramics, were with the peninsula of Armorica across the Channel, rather than with the southeast of Britain. They do not seem to have been politically centralised: coins are relatively rare, none of them locally minted, and the structure, distribution and construction of Bronze Age and Iron Age hill forts, "rounds" and defensible farmsteads in the south west point to a number of smaller tribal groups living alongside each other.
Dumnonia is noteworthy for its many settlements that have survived from the Romano-British period, but also for its lack of a villa system. Local archaeology has revealed instead the isolated enclosed farmsteads known locally as "rounds". These seem to have survived the Roman abandonment of Britain, but were subsequently replaced, in the 6th and 7th centuries, by the unenclosed farms taking the Brythonic toponymic "tre-".
As in most other Brythonic areas, Iron Age hill forts, such as Hembury Castle, were refortified for the use of chieftains or kings. Other high-status settlements such as Tintagel seem to have been reconstructed during this period. Post-Roman imported pottery has been excavated from many sites across the region, and the apparent surge in late 5th century Mediterranean and/or Byzantine imports is yet to be explained satisfactorily.
Apart from fishing and agriculture, the main economic resource of the Dumnonii was tin mining. The area of Dumnonia had been mined since ancient times, and the tin was exported from the ancient trading port of Ictis (St Michael's Mount). Tin extraction (mainly by streaming) had existed here from the early Bronze Age around the 22nd century BC. West Cornwall, around Mount's Bay, was traditionally thought to have been visited by metal traders from the eastern Mediterranean
During the first millennium BC trade became more organised, first with the Phoenicians, who settled Gades (Cadiz) around 1100 BC, and later with the Greeks, who had settled Massilia (Marseilles) and Narbo (Narbonne) around 600 BC. Smelted Cornish tin was collected at Ictis whence it was conveyed across the Bay of Biscay to the mouth of the Loire and then to Gades via the Loire and Rhone valleys. It went then through the Mediterranean Sea in ships to Gades.
During the period c. 500-450 BC, the tin deposits seem to have become more important, and fortified settlements appear such as at Chun Castle and Kenidjack Castle, to protect both the tin smelters and mines.
The earliest account of Cornish tin mining was written by Pytheas of Massilia late in the 4th century BC after his circumnavigation of the British Isles. Underground mining was described in this account, although it cannot be determined when it had started. Pytheas's account was noted later by other writers including Pliny the Elder and Diodorus Siculus.
It is likely that tin trade with the Mediterranean was later on under the control of the Veneti. Britain was one of the places proposed for the "Cassiterides", that is Tin Islands. Tin working continued throughout Roman occupation although it appears that output declined because of new supplies brought in from the deposits discovered in Iberia (Spain and Portugal). However, when these supplies diminished, production in Dumnonia increased and appears to have reached a peak during the 3rd century AD.
The Sub-Roman or Post-Roman history of Dumnonia comes from a variety of sources and is considered exceedingly difficult to interpret given that historical fact, legend and confused pseudo-history are compounded by a variety of sources in Middle Welsh and Latin. The main sources available for discussion of this period include Gildas's "De Excidio Britanniae" and Nennius's "Historia Brittonum", the "Annales Cambriae", "Anglo-Saxon Chronicle", William of Malmesbury's "Gesta Regum Anglorum" and "De Antiquitate Glastoniensis Ecclesiae", along with texts from the "Black Book of Carmarthen" and the "Red Book of Hergest", and Bede's "Historia ecclesiastica gentis Anglorum" as well as "The Descent of the Men of the North" ("Bonedd Gwŷr y Gogledd", in Peniarth MS 45 and elsewhere) and the "Book of Baglan". | https://en.wikipedia.org/wiki?curid=8368 |
Drag racing
Drag racing is a type of motor racing in which automobiles or motorcycles (usually specially prepared for the purpose) compete, usually two at a time, to be first to cross a set finish line. The race follows a short, straight course from a standing start over a measured distance, most commonly , with a shorter () distance becoming increasingly popular, as it has become the standard for Top Fuel dragsters and funny cars, where some major bracket races and other sanctioning bodies have adopted it as the standard. The is also popular in some circles. Electronic timing and speed sensing systems have been used to record race results since the 1960s.
The history of automobiles and motorcycles being used for drag racing is nearly as long as the history of motorized vehicles themselves, and has taken the form of both illegal street racing, and as an organized and regulated motorsport.
Push starts to get engines running were necessary until the National Hot Rod Association (NHRA) mandated self-starters in 1976. After burnouts, cars would be pushed back by crews; this persisted until NHRA required reversing systems in 1980. Don Garlits was the first to do burnouts across the starting line, which is now standard practise. Each driver then backs up to and stages at the starting line.
Before each race (commonly known as a pass), each driver is allowed to perform a burnout, which heats the driving tires and lays rubber down at the beginning of the track, improving traction. The cars run through a "water box" (formerly a "bleach box", before bleach was replaced by flammable traction compound, which produced spectacular, and dangerous, flame burnouts; the hazard led NHRA to mandate use of water in the 1970s).
Modern races are started electronically by a system known as a "Christmas tree", which consists of a column of lights for each driver/lane, and two light beam sensors per lane on the track at the starting line. Current NHRA trees, for example, feature one blue light (split into halves), then three amber, one green, and one red. When the first light beam is broken by a vehicle's front tire(s), the vehicle is "pre-staged" (approximately from the starting line), and the pre-stage indicator on the tree is lit. When the second light beam is broken, the vehicle is "staged", and the stage indicator on the tree is lit. Vehicles may then leave the pre-stage beam, but must remain in the stage beam until the race starts.
Once one competitor is staged, their opponent has a set amount of time to stage or they will be instantly disqualified, indicated by a red light on the tree. Otherwise, once both drivers are staged, the system chooses a short delay at random (to prevent a driver being able to anticipate the start), then starts the race. The light sequence at this point varies slightly. For example, in NHRA Professional classes, three amber lights on the tree flash simultaneously, followed 0.4 seconds later by a green light (this is also known as a "pro tree"). In NHRA Sportsman classes, the amber lights illuminate in sequence from top to bottom, 0.5 seconds apart, followed 0.5 seconds later by the green light (this is also known as a "sportsman tree" or "full tree"). If a vehicle leaves the starting line before the green light illuminates, the red light for that lane illuminates instead, and the driver is disqualified (also known as "red lighting"). In a handicap start, the green light automatically lights up for the first driver, and the red light is only lit in the proper lane after both cars have launched if one driver leaves early, or if both drivers left early, the driver whose reaction time is worse (if one lane has a -.015 and the other lane has a -.022, the lane of the driver who committed a 0.022 is given the red light after both cars have left), as a red light infraction is only assessed to the driver with the worse infraction, if both drivers leave early. Even if both drivers leave early, the green light is automatically lit for the driver that left last, and they still may win the pass (as in the 2014 NHRA Auto Club Pro Stock final, Erica Enders-Stevens and Jason Line both committed red light infractions; only Line was assessed with a red light, as he was -.011 versus Enders-Stevens' -.002).
Several measurements are taken for each race: reaction time, elapsed time, and speed. Reaction time is the period from the green light illuminating to the vehicle leaving the staging beams or breaking the guard beam. Elapsed time is the period from the vehicle leaving the starting line to crossing the finish line. Speed is measured through a speed trap covering the final to the finish line, indicating average speed of the vehicle in that distance.
Except where a breakout rule is in place, the winner is the first vehicle to cross the finish line, and therefore the driver with the lowest combined reaction time and elapsed time. Because these times are measured separately, a driver with a slower elapsed time can actually win if that driver's advantage in reaction time exceeds the elapsed time difference. In heads-up racing, this is known as a "holeshot win". In categories where a breakout rule is in effect (for example, NHRA Junior Dragster, Super Comp, Super Gas, Super Stock, and Stock classes, as well as some dial-in classes), if a competitor is faster than his or her predetermined time (a "breakout"), that competitor loses. If both competitors are faster than their predetermined times, the competitor who breaks out by less time wins. Regardless, a red light foul is worse than a breakout, except in Junior Dragster where exceeding the absolute limit is a cause for disqualification.
Most race events use a traditional bracket system, where the losing car and driver are eliminated from the event while the winner advances to the next round, until a champion is crowned. Events can range from 16 to over 100 car brackets. Drivers are typically seeded by elapsed times in qualifying. In bracket racing without a breakout (such as NHRA Competition Eliminator), pairings are based on times compared to their index (faster than index for class is better). In bracket racing with a breakout (Stock, Super Stock, but also the NHRA's Super classes), the closest to the index is favourable.
A popular alternative to the standard eliminations format is the Chicago Style format (also called the Three Round format in Australia), named for the US 30 Dragstrip in suburban Gary, Indiana where a midweek meet featured this format. All entered cars participate in one qualifying round, and then are paired for the elimination round. The two fastest times among winners from this round participate in the championship round. Depending on the organisation, the next two fastest times may play for third, then fifth, and so forth, in consolation rounds. Currently, an IHRA 400 Thunder championship race in Australia uses the format.
The standard distance of a drag race is 1,320 feet, 402 m, or 1/4 mile. However, due to safety concerns, certain sanctioning bodies (notably the NHRA for its Top Fuel and Funny Car classes) have shortened races to 1,000 feet. Some drag strips are even shorter and run 660 feet, 201 m, or 1/8 mile. The 1,000 foot distance is now also popular with bracket racing, especially in meets where there are 1/8 mile cars and 1/4 mile cars racing together, and is used by the revived American Drag Racing League for its primary classes (not Jr Dragster). Some organisations that deal with Pro Modified and "Mountain Motor" Pro Stock cars (Professional Drag Racers Association) use the 1/8 mile distance, even if the tracks are 1/4 mile tracks.
The National Hot Rod Association (NHRA) oversees the majority of drag racing events in North America. The next largest organization is the International Hot Rod Association (IHRA). Nearly all drag strips are associated with one sanctioning body or the other.
Besides NHRA and IHRA, there are niche organizations for muscle cars and nostalgia vehicles. The Nostalgia Drag Racing League (NDRL) based in Brownsburg, IN, runs a series of 1/4 mile (402m) drag races in the Midwest for 1979 and older nostalgic appearing cars, with four classes of competition running in an index system. Pro 7.0 and Pro 7.50 run heads up 200 mile per hour (320 kilometre per hour) passes, while Pro Comp and Pro Gas run 8.0 to 10.0 indices. NDRL competition vehicles typically include Front Engine Dragsters, Altereds, Funny Cars, early Pro Stock clones, Super Stocks and Gassers.
The National Electric Drag Racing Association (NEDRA) races electric vehicles against high performance gasoline-powered vehicles such as Dodge Vipers or classic muscle cars in 1/4 and 1/8 mile (402m & 201m) races. The current electric drag racing record is 6.940 seconds at 201.37 mph (324.0736 km/h) for a quarter mile (402m). Another niche organization is the VWDRC which run a VW-only championship with vehicles running under 7 seconds.
Prior to the founding of the NHRA and IHRA, smaller organizations sanctioned drag racing in the early years, which included the competing AHRA in the United States from 1955 to 2005.
The first Australian Nationals event was run in 1965 at Riverside raceway, near Melbourne. The Australian National Drag Racing Association (ANDRA) was established in 1973, and today they claim they are the "best in the world outside the United States". ANDRA sanctions races throughout Australia and throughout the year at all levels, from Junior Dragster to Top Fuel.
The ANDRA Drag Racing Series is for professional drivers and riders and includes Top Fuel, Top Alcohol, Top Doorslammer (similar to the USA Pro Modified class), Pro Stock (using 400 cubic inch engines (6.5 litres)), Top Bike and Pro Stock Motorcycle.
The Summit Sportsman Series is for ANDRA sportsman drivers and riders and includes Competition, Super Stock, Super Compact, Competition Bike, Supercharged Outlaws, Top Sportsman, Modified, Super Sedan, Modified Bike, Super Street and Junior Dragster.
In 2015, after a dispute with ANDRA, Sydney Dragway, Willowbank Raceway and the Perth Motorplex invited the International Hot Rod Association (IHRA) to sanction events at their tracks. Since then the Perth Motorplex has reverted to an ANDRA sanction and Springmount Raceway has embraced the IHRA umbrella. The 400 Thunder Series now attracts professional racers to its races at Sydney Dragway and Willowbank Raceway and is the premiere series in Australia.
Communications provider OVO Mobile provides a live stream of all 400 Thunder Australian Professional Drag Racing Series events to fans globally. The 400 Thunder Series is aired on SBS Speedweek.
Drag racing was imported to Europe by American NATO troops during the Cold War. Races were held in West Germany beginning in the 1960s at the airbases at Ramstein and Sembach and in the UK at various airstrips and racing circuits before the opening of Europe's first permanent drag strip at Santa Pod Raceway in 1966.
The FIA organises a Europe-wide four wheeled championship for the Top Fuel, Top Methanol Dragster, Top Methanol Funny Car, Pro Modified and Pro Stock classes. FIM Europe organises a similar championship for bike classes. In addition, championships are run for sportsman classes in many countries throughout Europe by the various national motorsport governing bodies.
Drag racing in New Zealand started in the 1960s. The New Zealand Hot Rod Association (NZHRA) sanctioned what is believed to have been the first drag meeting at an open cut coal mine at Kopuku, south of Auckland, sometime in 1966. In 1973, the first and only purpose built drag strip opened in Meremere by the Pukekohe Hot Rod Club. In April 1993 the governance of drag racing was separated from the NZHRA and the New Zealand Drag Racing Association (NZDRA) was formed. In 2014, New Zealand's second purpose built drag strip – Masterton Motorplex – opened.
The first New Zealand Drag Racing Nationals was held in the 1966/67 season at Kopuku, near Auckland.
There are now two governing bodies operating drag racing in New Zealand with the Florida-based International Hot Rod Association sanctioning both of New Zealands major tracks at Ruapuna (Pegasus Bay Drag Racing Association) in the South Island and Meremere Dragway Inc in the North Island which is now become the best drag strip in NZ. However, the official ASN of the sport, per FIA regulations, is the New Zealand Drag Racing Association.
Many countries in South America race 200 meters, unlike in the United States and Australia, where 400 meters or 1/4 mile is typical.
Organized drag racing in Colombia is the responsibility of Club G3, a private organization. The events take place at Autódromo de Tocancipá.
Curaçao
On the island of Curaçao, organization of drag racing events is handled by the Curaçao Autosport Foundation (FAC)
All racing events, including street legal competitions, happen at the Curaçao International Raceway.
On the island of Aruba, all racing events, including street legal competitions, happen at Palomarga International Raceway.
Barbados
On the island of Barbados, organization of drag racing events is done by the Barbados Association of Dragsters and Drifters. Currently the drag racing is done at Bushy Park racing circuit over 1/8 mile, while "acceleration tests" of 1/4 mile are done at the Paragon military base.
Saint Lucia
On the Island of Saint Lucia, organization of drag racing events is done by Time Line Events, currently races are held at the US Old military base also known as the "Ca Ca Beff", "The Base" near the Hewanorra International Airport in Vieux Fort.
Dominican Republic
On Santo Domingo, organization of drag racing events is done by Autodromo Sunix and they happen at the Autodromo Sunix, close to the Airport SDQ.
Organized drag racing is rapidly growing in India. The country's first drag race meet was organized by "Autocar India" in Mumbai in 2002. Since then there have been many drag racing events in India. The most popular event is Elite Octanes' Valley Run which is held at Ambey Valley air strip in Loanavla every year.
The biggest drag series event was organized by India Speed Week with three different locations around India. After the series two riders were chosen to represent the country 2017 initiative to bring 11 times world drag racing champion Rickey Gadson to India. The initiative was executed during the Valley Run 2017 event, which gave the participants a platform to perform at the highest level globally. Rickey Gadson, as an extension of the initiative invited two of the top performing drag racers to visit USA to train and get an opportunity to represent India at the World Finals of drag racing held on 16-18 November 2018 in Valdosta GA, USA.
As a result the two riders performed in their maiden event outside India. Also during the event, Amit Sharma, the fastest drag racer in Indian drag racing history, produced a time slip of 8.87 sec's – the fastest ever by any Indian.
Drag racing is also gaining popularity in Pakistan, with private organizations sponsoring such events. The Bahria Town housing project recently organized a drag racing event in Rawalpindi with the help of some of the country's best drivers.
Sri Lanka has seen an immense growth in drag racing due to legal meets held by the Ceylon Motor Sports Club, an FIA sanctioned body. In recent years, exotic cars and Japanese power houses have been taking part in these popular events.
Drag racing is an established sport in South Africa, with a number of strips around the country including Tarlton International Raceway and ODI Raceway. Drag racing is controlled by Motorsport South Africa and all drivers are required to hold a valid Motorsport South Africa license. Drivers can compete in a number of categories including Top Eliminator, Senior Eliminator, Super Competition Eliminator, Competition Eliminator, Pro Street Bikes, Superbike Eliminator, Supersport Shootout (motorcycle), Street Modified, and Factory Stock.
There are hundreds of classes in drag racing, each with different requirements and restrictions on things such as weight, engine size, body style, modifications, and many others. NHRA and IHRA share some of these classes, but many are solely used by one sanctioning body or the other. The NHRA boasts over 200 classes, while the IHRA has fewer. Some IHRA classes have multiple sub-classes in them to differentiate by engine components and other features. There is even a class for aspiring youngsters, Junior Dragster, which typically uses an eighth-mile track, also favored by VW racers.
In 1997, the FIA (cars) and UEM (bikes) began sanctioning drag racing in Europe with a fully established European Drag Racing Championship, in cooperation (and rules compliance) with NHRA. The major European drag strips include Santa Pod Raceway in Podington, England; Alastaro Circuit, Finland; Mantorp Park, Sweden; Gardermoen Raceway, Norway and the Hockenheimring in Germany.
There is a somewhat arbitrary definition of what constitutes a "professional" class. The NHRA includes 5 pro classes; Top Fuel, Funny Car, Pro Stock, Pro Modified and Pro Stock Motorcycle. The FIA features a different set of 5 pro classes; Top Fuel, Top Methanol Dragster, Top Methanol Funny Car, Pro Modified and Pro Stock. Other sanctioning bodies have similarly different definitions. A partial list of classes includes:
A complete listing of all classes can be found on the respective NHRA and IHRA official websites.
The UEM also has a different structure of professional categories with Top Fuel Bike, Super Twin Top Fuel Bike, and Pro Stock Bike contested, leaving the entire European series with a total of 8 professional categories.
To allow different cars to compete against each other, some competitions are raced on a handicap basis, with faster cars delayed on the starting line enough to theoretically even things up with the slower car. This may be based on rule differences between the cars in stock, super stock, and modified classes, or on a competitor's chosen "dial-in" in bracket racing.
For a list of drag racing world records in each class, see Dragstrip#Quarter mile times.
A 'dial-in' is a time the driver estimates it will take his or her car to cross the finish line, and is generally displayed on one or more windows so the starter can adjust the starting lights on the tree accordingly. The slower car will then get a head start equal to the difference in the two dial-ins, so if both cars perform perfectly, they would cross the finish line dead even. If either car goes faster than its dial-in (called breaking out), it is disqualified regardless of who has the lower elapsed time; if both cars break out, the one who breaks out by the smallest amount wins. However, if a driver had jump-started (red light) or crossed a boundary line, both violations override any break out (except in some classes with an absolute break out rule such as Junior classes).
The effect of the bracket racing rules is to place a premium on consistency of performance of the driver and car rather than on raw speed, in that victory goes to the driver able to precisely predict elapsed time, whether it is fast or slow. This in turn makes victory much less dependent on budget, and more dependent on skill, making it popular with casual weekend racers.
The National Hot Rod Association (NHRA) was founded in 1951, to take illegal racing off the street.
The organization banned the use of nitromethane in 1957, calling it unsafe, in part through the efforts of C. J. Hart; the ban would be lifted in 1963. | https://en.wikipedia.org/wiki?curid=8373 |
Day
A day is approximately the period of time during which the Earth completes one rotation around its axis. A solar day is the length of time which elapses between the Sun reaching its highest point in the sky two consecutive times. Days on other planets are defined similarly and vary in length due to differing rotation periods, that of Mars being slightly longer and sometimes called a sol.
In 1960, the second was redefined in terms of the orbital motion of the Earth in the year 1900, and was designated the SI base unit of time. The unit of measurement "day", was redefined as 86,400 SI seconds and symbolized "d". In 1967, the second and so the day were redefined by atomic electron transition. A civil day is usually 24 hours, plus or minus a possible leap second in Coordinated Universal Time (UTC), and occasionally plus or minus an hour in those locations that change from or to daylight saving time.
Day can be defined as each of the twenty-four-hour periods, reckoned from one midnight to the next, into which a week, month, or year is divided, and corresponding to a rotation of the earth on its axis. However, its use depends on its context; for example, when people say 'day and night', 'day' will have a different meaning: the interval of light between two successive nights, the time between sunrise and sunset; the time of light between one night and the next. For clarity when meaning 'day' in that sense, the word "daytime" may be used instead, | https://en.wikipedia.org/wiki?curid=8376 |
Database
A database is an organized collection of data, generally stored and accessed electronically from a computer system. Where databases are more complex they are often developed using formal design and modeling techniques.
The database management system (DBMS) is the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS software additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a "database system". Often the term "database" is also used to loosely refer to any of the DBMS, the database system or an application associated with the database.
Computer scientists may classify database-management systems according to the database models that they support. Relational databases became dominant in the 1980s. These model data as rows and columns in a series of tables, and the vast majority use SQL for writing and querying data. In the 2000s, non-relational databases became popular, referred to as NoSQL because they use different query languages.
Formally, a "database" refers to a set of related data and the way it is organized. Access to this data is usually provided by a "database management system" (DBMS) consisting of an integrated set of computer software that allows users to interact with one or more databases and provides access to all of the data contained in the database (although restrictions may exist that limit access to particular data). The DBMS provides various functions that allow entry, storage and retrieval of large quantities of information and provides ways to manage how that information is organized.
Because of the close relationship between them, the term "database" is often used casually to refer to both a database and the DBMS used to manipulate it.
Outside the world of professional information technology, the term "database" is often used to refer to any collection of related data (such as a spreadsheet or a card index) as size and usage requirements typically necessitate use of a database management system.
Existing DBMSs provide various functions that allow management of a database and its data which can be classified into four main functional groups:
Both a database and its DBMS conform to the principles of a particular database model. "Database system" refers collectively to the database model, database management system, and database.
Physically, database servers are dedicated computers that hold the actual databases and run only the DBMS and related software. Database servers are usually multiprocessor computers, with generous memory and RAID disk arrays used for stable storage. Hardware database accelerators, connected to one or more servers via a high-speed channel, are also used in large volume transaction processing environments. DBMSs are found at the heart of most database applications. DBMSs may be built around a custom multitasking kernel with built-in networking support, but modern DBMSs typically rely on a standard operating system to provide these functions.
Since DBMSs comprise a significant market, computer and storage vendors often take into account DBMS requirements in their own development plans.
Databases and DBMSs can be categorized according to the database model(s) that they support (such as relational or XML), the type(s) of computer they run on (from a server cluster to a mobile phone), the query language(s) used to access the database (such as SQL or XQuery), and their internal engineering, which affects performance, scalability, resilience, and security.
The sizes, capabilities, and performance of databases and their respective DBMSs have grown in orders of magnitude. These performance increases were enabled by the technology progress in the areas of processors, computer memory, computer storage, and computer networks. The development of database technology can be divided into three eras based on data model or structure: navigational, SQL/relational, and post-relational.
The two main early navigational data models were the hierarchical model and the CODASYL model (network model)
The relational model, first proposed in 1970 by Edgar F. Codd, departed from this tradition by insisting that applications should search for data by content, rather than by following links. The relational model employs sets of ledger-style tables, each used for a different type of entity. Only in the mid-1980s did computing hardware become powerful enough to allow the wide deployment of relational systems (DBMSs plus applications). By the early 1990s, however, relational systems dominated in all large-scale data processing applications, and they remain dominant: IBM DB2, Oracle, MySQL, and Microsoft SQL Server are the most searched DBMS. The dominant database language, standardised SQL for the relational model, has influenced database languages for other data models.
Object databases were developed in the 1980s to overcome the inconvenience of object-relational impedance mismatch, which led to the coining of the term "post-relational" and also the development of hybrid object-relational databases.
The next generation of post-relational databases in the late 2000s became known as NoSQL databases, introducing fast key-value stores and document-oriented databases. A competing "next generation" known as NewSQL databases attempted new implementations that retained the relational/SQL model while aiming to match the high performance of NoSQL compared to commercially available relational DBMSs.
The introduction of the term "database" coincided with the availability of direct-access storage (disks and drums) from the mid-1960s onwards. The term represented a contrast with the tape-based systems of the past, allowing shared interactive use rather than daily batch processing. The Oxford English Dictionary cites a 1962 report by the System Development Corporation of California as the first to use the term "data-base" in a specific technical sense.
As computers grew in speed and capability, a number of general-purpose database systems emerged; by the mid-1960s a number of such systems had come into commercial use. Interest in a standard began to grow, and Charles Bachman, author of one such product, the Integrated Data Store (IDS), founded the "Database Task Group" within CODASYL, the group responsible for the creation and standardization of COBOL. In 1971, the Database Task Group delivered their standard, which generally became known as the "CODASYL approach", and soon a number of commercial products based on this approach entered the market.
The CODASYL approach relied on the "manual" navigation of a linked data set which was formed into a large network. Applications could find records by one of three methods:
Later systems added B-trees to provide alternate access paths. Many CODASYL databases also added a very straightforward query language. However, in the final tally, CODASYL was very complex and required significant training and effort to produce useful applications.
IBM also had their own DBMS in 1966, known as Information Management System (IMS). IMS was a development of software written for the Apollo program on the System/360. IMS was generally similar in concept to CODASYL, but used a strict hierarchy for its model of data navigation instead of CODASYL's network model. Both concepts later became known as navigational databases due to the way data was accessed, and Bachman's 1973 Turing Award presentation was "The Programmer as Navigator". IMS is classified by IBM as a hierarchical database. IDMS and Cincom Systems' TOTAL database are classified as network databases. IMS remains in use .
Edgar F. Codd worked at IBM in San Jose, California, in one of their offshoot offices that was primarily involved in the development of hard disk systems. He was unhappy with the navigational model of the CODASYL approach, notably the lack of a "search" facility. In 1970, he wrote a number of papers that outlined a new approach to database construction that eventually culminated in the groundbreaking "A Relational Model of Data for Large Shared Data Banks".
In this paper, he described a new system for storing and working with large databases. Instead of records being stored in some sort of linked list of free-form records as in CODASYL, Codd's idea was to use a "table" of fixed-length records, with each table used for a different type of entity. A linked-list system would be very inefficient when storing "sparse" databases where some of the data for any one record could be left empty. The relational model solved this by splitting the data into a series of normalized tables (or "relations"), with optional elements being moved out of the main table to where they would take up room only if needed. Data may be freely inserted, deleted and edited in these tables, with the DBMS doing whatever maintenance needed to present a table view to the application/user.
The relational model also allowed the content of the database to evolve without constant rewriting of links and pointers. The relational part comes from entities referencing other entities in what is known as one-to-many relationship, like a traditional hierarchical model, and many-to-many relationship, like a navigational (network) model. Thus, a relational model can express both hierarchical and navigational models, as well as its native tabular model, allowing for pure or combined modeling in terms of these three models, as the application requires.
For instance, a common use of a database system is to track information about users, their name, login information, various addresses and phone numbers. In the navigational approach, all of this data would be placed in a single record, and unused items would simply not be placed in the database. In the relational approach, the data would be "normalized" into a user table, an address table and a phone number table (for instance). Records would be created in these optional tables only if the address or phone numbers were actually provided.
Linking the information back together is the key to this system. In the relational model, some bit of information was used as a "key", uniquely defining a particular record. When information was being collected about a user, information stored in the optional tables would be found by searching for this key. For instance, if the login name of a user is unique, addresses and phone numbers for that user would be recorded with the login name as its key. This simple "re-linking" of related data back into a single collection is something that traditional computer languages are not designed for.
Just as the navigational approach would require programs to loop in order to collect records, the relational approach would require loops to collect information about any "one" record. Codd's suggestions was a set-oriented language, that would later spawn the ubiquitous SQL. Using a branch of mathematics known as tuple calculus, he demonstrated that such a system could support all the operations of normal databases (inserting, updating etc.) as well as providing a simple system for finding and returning "sets" of data in a single operation.
Codd's paper was picked up by two people at Berkeley, Eugene Wong and Michael Stonebraker. They started a project known as INGRES using funding that had already been allocated for a geographical database project and student programmers to produce code. Beginning in 1973, INGRES delivered its first test products which were generally ready for widespread use in 1979. INGRES was similar to System R in a number of ways, including the use of a "language" for data access, known as QUEL. Over time, INGRES moved to the emerging SQL standard.
IBM itself did one test implementation of the relational model, PRTV, and a production one, Business System 12, both now discontinued. Honeywell wrote MRDS for Multics, and now there are two new implementations: Alphora Dataphor and Rel. Most other DBMS implementations usually called "relational" are actually SQL DBMSs.
In 1970, the University of Michigan began development of the MICRO Information Management System based on D.L. Childs' Set-Theoretic Data model. MICRO was used to manage very large data sets by the US Department of Labor, the U.S. Environmental Protection Agency, and researchers from the University of Alberta, the University of Michigan, and Wayne State University. It ran on IBM mainframe computers using the Michigan Terminal System. The system remained in production until 1998.
In the 1970s and 1980s, attempts were made to build database systems with integrated hardware and software. The underlying philosophy was that such integration would provide higher performance at lower cost. Examples were IBM System/38, the early offering of Teradata, and the Britton Lee, Inc. database machine.
Another approach to hardware support for database management was ICL's CAFS accelerator, a hardware disk controller with programmable search capabilities. In the long term, these efforts were generally unsuccessful because specialized database machines could not keep pace with the rapid development and progress of general-purpose computers. Thus most database systems nowadays are software systems running on general-purpose hardware, using general-purpose computer data storage. However this idea is still pursued for certain applications by some companies like Netezza and Oracle (Exadata).
IBM started working on a prototype system loosely based on Codd's concepts as "System R" in the early 1970s. The first version was ready in 1974/5, and work then started on multi-table systems in which the data could be split so that all of the data for a record (some of which is optional) did not have to be stored in a single large "chunk". Subsequent multi-user versions were tested by customers in 1978 and 1979, by which time a standardized query language – SQL – had been added. Codd's ideas were establishing themselves as both workable and superior to CODASYL, pushing IBM to develop a true production version of System R, known as "SQL/DS", and, later, "Database 2" (DB2).
Larry Ellison's Oracle Database (or more simply, Oracle) started from a different chain, based on IBM's papers on System R. Though Oracle V1 implementations were completed in 1978, it wasn't until Oracle Version 2 when Ellison beat IBM to market in 1979.
Stonebraker went on to apply the lessons from INGRES to develop a new database, Postgres, which is now known as PostgreSQL. PostgreSQL is often used for global mission critical applications (the .org and .info domain name registries use it as their primary data store, as do many large companies and financial institutions).
In Sweden, Codd's paper was also read and Mimer SQL was developed from the mid-1970s at Uppsala University. In 1984, this project was consolidated into an independent enterprise.
Another data model, the entity–relationship model, emerged in 1976 and gained popularity for database design as it emphasized a more familiar description than the earlier relational model. Later on, entity–relationship constructs were retrofitted as a data modeling construct for the relational model, and the difference between the two have become irrelevant.
The 1980s ushered in the age of desktop computing. The new computers empowered their users with spreadsheets like Lotus 1-2-3 and database software like dBASE. The dBASE product was lightweight and easy for any computer user to understand out of the box. C. Wayne Ratliff, the creator of dBASE, stated: "dBASE was different from programs like BASIC, C, FORTRAN, and COBOL in that a lot of the dirty work had already been done. The data manipulation is done by dBASE instead of by the user, so the user can concentrate on what he is doing, rather than having to mess with the dirty details of opening, reading, and closing files, and managing space allocation." dBASE was one of the top selling software titles in the 1980s and early 1990s.
The 1990s, along with a rise in object-oriented programming, saw a growth in how data in various databases were handled. Programmers and designers began to treat the data in their databases as objects. That is to say that if a person's data were in a database, that person's attributes, such as their address, phone number, and age, were now considered to belong to that person instead of being extraneous data. This allows for relations between data to be relations to objects and their attributes and not to individual fields. The term "object-relational impedance mismatch" described the inconvenience of translating between programmed objects and database tables. Object databases and object-relational databases attempt to solve this problem by providing an object-oriented language (sometimes as extensions to SQL) that programmers can use as alternative to purely relational SQL. On the programming side, libraries known as object-relational mappings (ORMs) attempt to solve the same problem.
XML databases are a type of structured document-oriented database that allows querying based on XML document attributes. XML databases are mostly used in applications where the data is conveniently viewed as a collection of documents, with a structure that can vary from the very flexible to the highly rigid: examples include scientific articles, patents, tax filings, and personnel records.
NoSQL databases are often very fast, do not require fixed table schemas, avoid join operations by storing denormalized data, and are designed to scale horizontally.
In recent years, there has been a strong demand for massively distributed databases with high partition tolerance, but according to the CAP theorem it is impossible for a distributed system to simultaneously provide consistency, availability, and partition tolerance guarantees. A distributed system can satisfy any two of these guarantees at the same time, but not all three. For that reason, many NoSQL databases are using what is called eventual consistency to provide both availability and partition tolerance guarantees with a reduced level of data consistency.
NewSQL is a class of modern relational databases that aims to provide the same scalable performance of NoSQL systems for online transaction processing (read-write) workloads while still using SQL and maintaining the ACID guarantees of a traditional database system.
Databases are used to support internal operations of organizations and to underpin online interactions with customers and suppliers (see Enterprise software).
Databases are used to hold administrative information and more specialized data, such as engineering data or economic models. Examples include computerized library systems, flight reservation systems, computerized parts inventory systems, and many content management systems that store websites as collections of webpages in a database.
One way to classify databases involves the type of their contents, for example: bibliographic, document-text, statistical, or multimedia objects. Another way is by their application area, for example: accounting, music compositions, movies, banking, manufacturing, or insurance. A third way is by some technical aspect, such as the database structure or interface type. This section lists a few of the adjectives used to characterize different kinds of databases.
Connolly and Begg define database management system (DBMS) as a "software system that enables users to define, create, maintain and control access to the database". Examples of DBMS's include MySQL, PostgreSQL, MSSQL, Oracle Database, and Microsoft Access.
The DBMS acronym is sometimes extended to indicate the underlying database model, with RDBMS for the relational, OODBMS for the object (oriented) and ORDBMS for the object-relational model. Other extensions can indicate some other characteristic, such as DDBMS for a distributed database management systems.
The functionality provided by a DBMS can vary enormously. The core functionality is the storage, retrieval and update of data. Codd proposed the following functions and services a fully-fledged general purpose DBMS should provide:
It is also generally to be expected the DBMS will provide a set of utilities for such purposes as may be necessary to administer the database effectively, including import, export, monitoring, defragmentation and analysis utilities. The core part of the DBMS interacting between the database and the application interface sometimes referred to as the database engine.
Often DBMSs will have configuration parameters that can be statically and dynamically tuned, for example the maximum amount of main memory on a server the database can use. The trend is to minimise the amount of manual configuration, and for cases such as embedded databases the need to target zero-administration is paramount.
The large major enterprise DBMSs have tended to increase in size and functionality and can have involved thousands of human years of development effort through their lifetime.
Early multi-user DBMS typically only allowed for the application to reside on the same computer with access via terminals or terminal emulation software. The client–server architecture was a development where the application resided on a client desktop and the database on a server allowing the processing to be distributed. This evolved into a multitier architecture incorporating application servers and web servers with the end user interface via a web browser with the database only directly connected to the adjacent tier.
A general-purpose DBMS will provide public application programming interfaces (API) and optionally a processor for database languages such as SQL to allow applications to be written to interact with the database. A special purpose DBMS may use a private API and be specifically customised and linked to a single application. For example, an email system performing many of the functions of a general-purpose DBMS such as message insertion, message deletion, attachment handling, blocklist lookup, associating messages an email address and so forth however these functions are limited to what is required to handle email.
External interaction with the database will be via an application program that interfaces with the DBMS. This can range from a database tool that allows users to execute SQL queries textually or graphically, to a web site that happens to use a database to store and search information.
A programmer will code interactions to the database (sometimes referred to as a datasource) via an application program interface (API) or via a database language. The particular API or language chosen will need to be supported by DBMS, possible indirectly via a pre-processor or a bridging API. Some API's aim to be database independent, ODBC being a commonly known example. Other common API's include JDBC and ADO.NET.
Database languages are special-purpose languages, which allow one or more of the following tasks, sometimes distinguished as sublanguages:
Database languages are specific to a particular data model. Notable examples include:
A database language may also incorporate features like:
Database storage is the container of the physical materialization of a database. It comprises the "internal" (physical) "level" in the database architecture. It also contains all the information needed (e.g., metadata, "data about the data", and internal data structures) to reconstruct the "conceptual level" and "external level" from the internal level when needed. Putting data into permanent storage is generally the responsibility of the database engine a.k.a. "storage engine". Though typically accessed by a DBMS through the underlying operating system (and often using the operating systems' file systems as intermediates for storage layout), storage properties and configuration setting are extremely important for the efficient operation of the DBMS, and thus are closely maintained by database administrators. A DBMS, while in operation, always has its database residing in several types of storage (e.g., memory and external storage). The database data and the additional needed information, possibly in very large amounts, are coded into bits. Data typically reside in the storage in structures that look completely different from the way the data look in the conceptual and external levels, but in ways that attempt to optimize (the best possible) these levels' reconstruction when needed by users and programs, as well as for computing additional types of needed information from the data (e.g., when querying the database).
Some DBMSs support specifying which character encoding was used to store data, so multiple encodings can be used in the same database.
Various low-level database storage structures are used by the storage engine to serialize the data model so it can be written to the medium of choice. Techniques such as indexing may be used to improve performance. Conventional storage is row-oriented, but there are also column-oriented and correlation databases.
Often storage redundancy is employed to increase performance. A common example is storing "materialized views", which consist of frequently needed "external views" or query results. Storing such views saves the expensive computing of them each time they are needed. The downsides of materialized views are the overhead incurred when updating them to keep them synchronized with their original updated database data, and the cost of storage redundancy.
Occasionally a database employs storage redundancy by database objects replication (with one or more copies) to increase data availability (both to improve performance of simultaneous multiple end-user accesses to a same database object, and to provide resiliency in a case of partial failure of a distributed database). Updates of a replicated object need to be synchronized across the object copies. In many cases, the entire database is replicated.
Database security deals with all various aspects of protecting the database content, its owners, and its users. It ranges from protection from intentional unauthorized database uses to unintentional database accesses by unauthorized entities (e.g., a person or a computer program).
Database access control deals with controlling who (a person or a certain computer program) is allowed to access what information in the database. The information may comprise specific database objects (e.g., record types, specific records, data structures), certain computations over certain objects (e.g., query types, or specific queries), or using specific access paths to the former (e.g., using specific indexes or other data structures to access information). Database access controls are set by special authorized (by the database owner) personnel that uses dedicated protected security DBMS interfaces.
This may be managed directly on an individual basis, or by the assignment of individuals and privileges to groups, or (in the most elaborate models) through the assignment of individuals and groups to roles which are then granted entitlements. Data security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database or subsets of it called "subschemas". For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data. If the DBMS provides a way to interactively enter and update the database, as well as interrogate it, this capability allows for managing personal databases.
Data security in general deals with protecting specific chunks of data, both physically (i.e., from corruption, or destruction, or removal; e.g., see physical security), or the interpretation of them, or parts of them to meaningful information (e.g., by looking at the strings of bits that they comprise, concluding specific valid credit-card numbers; e.g., see data encryption).
Change and access logging records who accessed which attributes, what was changed, and when it was changed. Logging services allow for a forensic database audit later by keeping a record of access occurrences and changes. Sometimes application-level code is used to record changes rather than leaving this to the database. Monitoring can be set up to attempt to detect security breaches.
Database transactions can be used to introduce some level of fault tolerance and data integrity after recovery from a crash. A database transaction is a unit of work, typically encapsulating a number of operations over a database (e.g., reading a database object, writing, acquiring lock, etc.), an abstraction supported in database and also other systems. Each transaction has well defined boundaries in terms of which program/code executions are included in that transaction (determined by the transaction's programmer via special transaction commands).
The acronym ACID describes some ideal properties of a database transaction: atomicity, consistency, isolation, and durability.
A database built with one DBMS is not portable to another DBMS (i.e., the other DBMS cannot run it). However, in some situations, it is desirable to migrate a database from one DBMS to another. The reasons are primarily economical (different DBMSs may have different total costs of ownership or TCOs), functional, and operational (different DBMSs may have different capabilities). The migration involves the database's transformation from one DBMS type to another. The transformation should maintain (if possible) the database related application (i.e., all related application programs) intact. Thus, the database's conceptual and external architectural levels should be maintained in the transformation. It may be desired that also some aspects of the architecture internal level are maintained. A complex or large database migration may be a complicated and costly (one-time) project by itself, which should be factored into the decision to migrate. This in spite of the fact that tools may exist to help migration between specific DBMSs. Typically, a DBMS vendor provides tools to help importing databases from other popular DBMSs.
After designing a database for an application, the next stage is building the database. Typically, an appropriate general-purpose DBMS can be selected to be used for this purpose. A DBMS provides the needed user interfaces to be used by database administrators to define the needed application's data structures within the DBMS's respective data model. Other user interfaces are used to select needed DBMS parameters (like security related, storage allocation parameters, etc.).
When the database is ready (all its data structures and other needed components are defined), it is typically populated with initial application's data (database initialization, which is typically a distinct project; in many cases using specialized DBMS interfaces that support bulk insertion) before making it operational. In some cases, the database becomes operational while empty of application data, and data are accumulated during its operation.
After the database is created, initialised and populated it needs to be maintained. Various database parameters may need changing and the database may need to be tuned (tuning) for better performance; application's data structures may be changed or added, new related application programs may be written to add to the application's functionality, etc.
Sometimes it is desired to bring a database back to a previous state (for many reasons, e.g., cases when the database is found corrupted due to a software error, or if it has been updated with erroneous data). To achieve this, a backup operation is done occasionally or continuously, where each desired database state (i.e., the values of its data and their embedding in database's data structures) is kept within dedicated backup files (many techniques exist to do this effectively). When it is decided by a database administrator to bring the database back to this state (e.g., by specifying this state by a desired point in time when the database was in this state), these files are used to restore that state.
Static analysis techniques for software verification can be applied also in the scenario of query languages. In particular, the *Abstract interpretation framework has been extended to the field of query languages for relational databases as a way to support sound approximation techniques. The semantics of query languages can be tuned according to suitable abstractions of the concrete domain of data. The abstraction of relational database system has many interesting applications, in particular, for security purposes, such as fine grained access control, watermarking, etc.
Other DBMS features might include:
Increasingly, there are calls for a single system that incorporates all of these core functionalities into the same build, test, and deployment framework for database management and source control. Borrowing from other developments in the software industry, some market such offerings as "DevOps for database".
The first task of a database designer is to produce a conceptual data model that reflects the structure of the information to be held in the database. A common approach to this is to develop an entity-relationship model, often with the aid of drawing tools. Another popular approach is the Unified Modeling Language. A successful data model will accurately reflect the possible state of the external world being modeled: for example, if people can have more than one phone number, it will allow this information to be captured. Designing a good conceptual data model requires a good understanding of the application domain; it typically involves asking deep questions about the things of interest to an organization, like "can a customer also be a supplier?", or "if a product is sold with two different forms of packaging, are those the same product or different products?", or "if a plane flies from New York to Dubai via Frankfurt, is that one flight or two (or maybe even three)?". The answers to these questions establish definitions of the terminology used for entities (customers, products, flights, flight segments) and their relationships and attributes.
Producing the conceptual data model sometimes involves input from business processes, or the analysis of workflow in the organization. This can help to establish what information is needed in the database, and what can be left out. For example, it can help when deciding whether the database needs to hold historic data as well as current data.
Having produced a conceptual data model that users are happy with, the next stage is to translate this into a schema that implements the relevant data structures within the database. This process is often called logical database design, and the output is a logical data model expressed in the form of a schema. Whereas the conceptual data model is (in theory at least) independent of the choice of database technology, the logical data model will be expressed in terms of a particular database model supported by the chosen DBMS. (The terms "data model" and "database model" are often used interchangeably, but in this article we use "data model" for the design of a specific database, and "database model" for the modeling notation used to express that design).
The most popular database model for general-purpose databases is the relational model, or more precisely, the relational model as represented by the SQL language. The process of creating a logical database design using this model uses a methodical approach known as normalization. The goal of normalization is to ensure that each elementary "fact" is only recorded in one place, so that insertions, updates, and deletions automatically maintain consistency.
The final stage of database design is to make the decisions that affect performance, scalability, recovery, security, and the like, which depend on the particular DBMS. This is often called "physical database design", and the output is the physical data model. A key goal during this stage is data independence, meaning that the decisions made for performance optimization purposes should be invisible to end-users and applications. There are two types of data independence: Physical data independence and logical data independence. Physical design is driven mainly by performance requirements, and requires a good knowledge of the expected workload and access patterns, and a deep understanding of the features offered by the chosen DBMS.
Another aspect of physical database design is security. It involves both defining access control to database objects as well as defining security levels and methods for the data itself.
A database model is a type of data model that determines the logical structure of a database and fundamentally determines in which manner data can be stored, organized, and manipulated. The most popular example of a database model is the relational model (or the SQL approximation of relational), which uses a table-based format.
Common logical data models for databases include:
An object-relational database combines the two related structures.
Physical data models include:
Other models include:
Specialized models are optimized for particular types of data:
A database management system provides three views of the database data:
While there is typically only one conceptual (or logical) and physical (or internal) view of the data, there can be any number of different external views. This allows users to see database information in a more business-related way rather than from a technical, processing viewpoint. For example, a financial department of a company needs the payment details of all employees as part of the company's expenses, but does not need details about employees that are the interest of the human resources department. Thus different departments need different "views" of the company's database.
The three-level database architecture relates to the concept of "data independence" which was one of the major initial driving forces of the relational model. The idea is that changes made at a certain level do not affect the view at a higher level. For example, changes in the internal level do not affect application programs written using conceptual level interfaces, which reduces the impact of making physical changes to improve performance.
The conceptual view provides a level of indirection between internal and external. On one hand it provides a common view of the database, independent of different external view structures, and on the other hand it abstracts away details of how the data are stored or managed (internal level). In principle every level, and even every external view, can be presented by a different data model. In practice usually a given DBMS uses the same data model for both the external and the conceptual levels (e.g., relational model). The internal level, which is hidden inside the DBMS and depends on its implementation, requires a different level of detail and uses its own types of data structure types.
Separating the "external", "conceptual" and "internal" levels was a major feature of the relational database model implementations that dominate 21st century databases.
Database technology has been an active research topic since the 1960s, both in academia and in the research and development groups of companies (for example IBM Research). Research activity includes theory and development of prototypes. Notable research topics have included models, the atomic transaction concept, and related concurrency control techniques, query languages and query optimization methods, RAID, and more.
The database research area has several dedicated academic journals (for example, "ACM Transactions on Database Systems"-TODS, "Data and Knowledge Engineering"-DKE) and annual conferences (e.g., ACM SIGMOD, ACM PODS, VLDB, IEEE ICDE). | https://en.wikipedia.org/wiki?curid=8377 |
Dipole
In electromagnetism, there are two kinds of dipoles:
Whether electric or magnetic, dipoles can be characterized by their dipole moment, a vector quantity. For the simple electric dipole, the electric dipole moment points from the negative charge towards the positive charge, and has a magnitude equal to the strength of each charge times the separation between the charges. (To be precise: for the definition of the dipole moment, one should always consider the "dipole limit", where, for example, the distance of the generating charges should "converge" to 0 while simultaneously, the charge strength should "diverge" to infinity in such a way that the product remains a positive constant.)
For the magnetic (dipole) current loop, the magnetic dipole moment points through the loop (according to the right hand grip rule), with a magnitude equal to the current in the loop times the area of the loop.
Similar to magnetic current loops, the electron particle and some other fundamental particles have magnetic dipole moments, as an electron generates a magnetic field identical to that generated by a very small current loop. However, an electron's magnetic dipole moment is not due to a current loop, but to an intrinsic property of the electron. The electron may also have an "electric" dipole moment though such has yet to be observed (see electron electric dipole moment).
A permanent magnet, such as a bar magnet, owes its magnetism to the intrinsic magnetic dipole moment of the electron. The two ends of a bar magnet are referred to as poles—not to be confused with monopoles, see Classification below)—and may be labeled "north" and "south". In terms of the Earth's magnetic field, they are respectively "north-seeking" and "south-seeking" poles: if the magnet were freely suspended in the Earth's magnetic field, the north-seeking pole would point towards the north and the south-seeking pole would point towards the south. The dipole moment of the bar magnet points from its magnetic south to its magnetic north pole. In a magnetic compass, the north pole of a bar magnet points north. However, that means that Earth's geomagnetic north pole is the "south" pole (south-seeking pole) of its dipole moment and vice versa.
The only known mechanisms for the creation of magnetic dipoles are by current loops or quantum-mechanical spin since the existence of magnetic monopoles has never been experimentally demonstrated.
The term comes from the Greek ("dis"), "twice" and ("polos"), "axis".
A "physical dipole" consists of two equal and opposite point charges: in the literal sense, two poles. Its field at large distances (i.e., distances large in comparison to the separation of the poles) depends almost entirely on the dipole moment as defined above. A "point (electric) dipole" is the limit obtained by letting the separation tend to 0 while keeping the dipole moment fixed. The field of a point dipole has a particularly simple form, and the order-1 term in the multipole expansion is precisely the point dipole field.
Although there are no known magnetic monopoles in nature, there are magnetic dipoles in the form of the quantum-mechanical spin associated with particles such as electrons (although the accurate description of such effects falls outside of classical electromagnetism). A theoretical magnetic "point dipole" has a magnetic field of exactly the same form as the electric field of an electric point dipole. A very small current-carrying loop is approximately a magnetic point dipole; the magnetic dipole moment of such a loop is the product of the current flowing in the loop and the (vector) area of the loop.
Any configuration of charges or currents has a 'dipole moment', which describes the dipole whose field is the best approximation, at large distances, to that of the given configuration. This is simply one term in the multipole expansion when the total charge ("monopole moment") is 0—as it "always" is for the magnetic case, since there are no magnetic monopoles. The dipole term is the dominant one at large distances: Its field falls off in proportion to , as compared to for the next (quadrupole) term and higher powers of for higher terms, or for the monopole term.
Many molecules have such dipole moments due to non-uniform distributions of positive and negative charges on the various atoms. Such is the case with polar compounds like hydrogen fluoride (HF), where electron density is shared unequally between atoms. Therefore, a molecule's dipole is an electric dipole with an inherent electric field that should not be confused with a magnetic dipole which generates a magnetic field.
The physical chemist Peter J. W. Debye was the first scientist to study molecular dipoles extensively, and, as a consequence, dipole moments are measured in units named "debye" in his honor.
For molecules there are three types of dipoles:
More generally, an induced dipole of "any" polarizable charge distribution "ρ" (remember that a molecule has a charge distribution) is caused by an electric field external to "ρ". This field may, for instance, originate from an ion or polar molecule in the vicinity of "ρ" or may be macroscopic (e.g., a molecule between the plates of a charged capacitor). The size of the induced dipole moment is equal to the product of the strength of the external field and the dipole polarizability of "ρ".
Dipole moment values can be obtained from measurement of the dielectric constant. Some typical gas phase values in debye units are:
Potassium bromide (KBr) has one of the highest dipole moments because it is an ionic compound that exists as a molecule in the gas phase.
The overall dipole moment of a molecule may be approximated as a vector sum of bond dipole moments. As a vector sum it depends on the relative orientation of the bonds, so that from the dipole moment information can be deduced about the molecular geometry.
For example, the zero dipole of CO2 implies that the two C=O bond dipole moments cancel so that the molecule must be linear. For H2O the O−H bond moments do not cancel because the molecule is bent. For ozone (O3) which is also a bent molecule, the bond dipole moments are not zero even though the O−O bonds are between similar atoms. This agrees with the Lewis structures for the resonance forms of ozone which show a positive charge on the central oxygen atom.
An example in organic chemistry of the role of geometry in determining dipole moment is the "cis" and "trans" isomers of 1,2-dichloroethene. In the "cis" isomer the two polar C−Cl bonds are on the same side of the C=C double bond and the molecular dipole moment is 1.90 D. In the "trans" isomer, the dipole moment is zero because the two C−Cl bonds are on opposite sides of the C=C and cancel (and the two bond moments for the much less polar C−H bonds also cancel).
Another example of the role of molecular geometry is boron trifluoride, which has three polar bonds with a difference in electronegativity greater than the traditionally cited threshold of 1.7 for ionic bonding. However, due to the equilateral triangular distribution of the fluoride ions about the boron cation center, the molecule as a whole does not exhibit any identifiable pole: one cannot construct a plane that divides the molecule into a net negative part and a net positive part.
Consider a collection of "N" particles with charges "qi" and position vectors r"i". For instance, this collection may be a molecule consisting of electrons, all with charge −"e", and nuclei with charge "eZi", where "Zi" is the atomic number of the "i" th nucleus.
The dipole observable (physical quantity) has the quantum mechanical dipole operator:
Notice that this definition is valid only for neutral atoms or molecules, i.e. total charge equal to zero. In the ionized case, we have
where formula_3 is the center of mass of the molecule/group of particles.
A non-degenerate ("S"-state) atom can have only a zero permanent dipole. This fact follows quantum mechanically from the inversion symmetry of atoms. All 3 components of the dipole operator are antisymmetric under inversion with respect to the nucleus,
where formula_5 is the dipole operator and formula_6 is the inversion operator.
The permanent dipole moment of an atom in a non-degenerate state (see degenerate energy level) is given as the expectation (average) value of the dipole operator,
where formula_8 is an "S"-state, non-degenerate, wavefunction, which is symmetric or antisymmetric under inversion: formula_9. Since the product of the wavefunction (in the ket) and its complex conjugate (in the bra) is always symmetric under inversion and its inverse,
it follows that the expectation value changes sign under inversion. We used here the fact that formula_11, being a symmetry operator, is unitary: formula_12 and by definition the Hermitian adjoint formula_13 may be moved from bra to ket and then becomes formula_14. Since the only quantity that is equal to minus itself is the zero, the expectation value vanishes,
In the case of open-shell atoms with degenerate energy levels, one could define a dipole moment by the aid of the first-order Stark effect. This gives a non-vanishing dipole (by definition proportional to a non-vanishing first-order Stark shift) only if some of the wavefunctions belonging to the degenerate energies have opposite parity; i.e., have different behavior under inversion. This is a rare occurrence, but happens for the excited H-atom, where 2s and 2p states are "accidentally" degenerate (see article Laplace–Runge–Lenz vector for the origin of this degeneracy) and have opposite parity (2s is even and 2p is odd).
The far-field strength, "B", of a dipole magnetic field is given by
where
Conversion to cylindrical coordinates is achieved using and
where "ρ" is the perpendicular distance from the "z"-axis. Then,
The field itself is a vector quantity:
where
This is "exactly" the field of a point dipole, "exactly" the dipole term in the multipole expansion of an arbitrary field, and "approximately" the field of any dipole-like configuration at large distances.
The vector potential A of a magnetic dipole is
with the same definitions as above.
The electrostatic potential at position r due to an electric dipole at the origin is given by:
where p is the (vector) dipole moment, and "є"0 is the permittivity of free space.
This term appears as the second term in the multipole expansion of an arbitrary electrostatic potential Φ(r). If the source of Φ(r) is a dipole, as it is assumed here, this term is the only non-vanishing term in the multipole expansion of Φ(r). The electric field from a dipole can be found from the gradient of this potential:
This is formally identical to the expression for the magnetic field of a point magnetic dipole with only a few names changed. In a real dipole, however, where the charges are physically separate, the "internal" field lines are different, since the magnetic field lines are continuous, while those of the electric field diverge or converge from the point charges. For further discussions about the internal field of dipoles, see or Magnetic moment#Internal magnetic field of a dipole.
Since the direction of an electric field is defined as the direction of the force on a positive charge, electric field lines point away from a positive charge and toward a negative charge.
When placed in an homogeneous electric or magnetic field, equal but opposite forces arise on each side of the dipole creating a torque }:
for an electric dipole moment p (in coulomb-meters), or
for a magnetic dipole moment m (in ampere-square meters).
The resulting torque will tend to align the dipole with the applied field, which in the case of an electric dipole, yields a potential energy of
The energy of a magnetic dipole is similarly
In addition to dipoles in electrostatics, it is also common to consider an electric or magnetic dipole that is oscillating in time. It is an extension, or a more physical next-step, to spherical wave radiation.
In particular, consider a harmonically oscillating electric dipole, with angular frequency "ω" and a dipole moment "p"0 along the ẑ direction of the form
In vacuum, the exact field produced by this oscillating dipole can be derived using the retarded potential formulation as:
For ≫ 1, the far-field takes the simpler form of a radiating "spherical" wave, but with angular dependence embedded in the cross-product:
The time-averaged Poynting vector
is not distributed isotropically, but concentrated around the directions lying perpendicular to the dipole moment, as a result of the non-spherical electric and magnetic waves. In fact, the spherical harmonic function (sin "θ") responsible for such toroidal angular distribution is precisely the "l" = 1 "p" wave.
The total time-average power radiated by the field can then be derived from the Poynting vector as
Notice that the dependence of the power on the fourth power of the frequency of the radiation is in accordance with the Rayleigh scattering, and the underlying effects why the sky consists of mainly blue colour.
A circular polarized dipole is described as a superposition of two linear dipoles. | https://en.wikipedia.org/wiki?curid=8378 |
Draught beer
Draught beer, also spelt draft, is beer served from a cask or keg rather than from a bottle or can. Draught beer served from a pressurised keg is also known as
Until Joseph Bramah patented the beer engine in 1785, beer was served directly from the barrel and carried to the customer. The Old English "" ("carry; pull") developed into a series of related words including "drag", "draw", and "draught". By the time Bramah's beer pumps became popular, the use of the term "draught" to refer to the acts of serving or drinking beer was well established and transferred easily to beer served via the hand pumps. In time, the word came to be restricted to only such beer. The usual spelling is now "draught" in the United Kingdom, Ireland, Australia, and New Zealand and more commonly "draft" in North America, although it can be spelt either way. Regardless of spelling, the word is pronounced or depending on the region the speaker is from.
Canned draught is beer served from a pressurised container featuring a widget. Smooth flow (also known as cream flow, nitrokeg, or smooth) is the name brewers give to draught beers pressurised with a partial nitrogen gas blend.
In 1691, an article in the "London Gazette" mentioned John Lofting, who held a patent for a fire engine: "The said patentee has also projected a very useful engine for starting of beer, and other liquors which will draw from 20 to 30 barrels an hour, which are completely fixed with brass joints and screws at reasonable rates".
In the early 20th century, draught beer started to be served from pressurised containers. Artificial carbonation was introduced in the United Kingdom in 1936, with Watney’s experimental pasteurised beer Red Barrel. Though this method of serving beer did not take hold in the UK until the late 1950s, it did become the favored method in the rest of Europe, where it is known by such terms as "en pression". The carbonation method of serving beer subsequently spread to the rest of the world; by the early 1970s the term "draught beer" almost exclusively referred to beer served under pressure as opposed to the traditional cask or barrel beer.
In Britain, the Campaign for Real Ale (CAMRA) was founded in 1971 to protect traditional—unpressurised—beer and brewing methods. The group devised the term "real ale" to differentiate between beer served from the cask and beer served under pressure. The term "real ale" has since been expanded to include bottle-conditioned beer.
Keg beer is often filtered and/or pasteurised, both of which are processes that render the yeast inactive.
In brewing parlance, a keg is different from a cask. A cask has a tap hole near the edge of the top, and a spile hole on the side used for conditioning the unfiltered and unpasteurised beer. A keg has a single opening in the centre of the top to which a flow pipe is attached. Kegs are artificially pressurised after fermentation with carbon dioxide or a mixture of carbon dioxide and nitrogen gas or especially in Czech Republic solely compressed air.
"Keg" has become a term of contempt used by some, particularly in the UK, since the 1960s when pasteurised draught beers started replacing traditional cask beers.
Keg beer was replacing traditional cask ale in all parts of the UK, primarily because it requires less care to handle. Since 1971, CAMRA has conducted a consumer campaign on behalf of those who prefer traditional cask beer. CAMRA has lobbied the British Parliament to ensure support for cask ale and microbreweries have sprung up to serve those consumers who prefer traditional cask beer.
Pressurised CO2 in the keg's headspace maintains carbonation in the beer. The CO2 pressure varies depending on the amount of CO2 already in the beer and the keg storage temperature. Occasionally the CO2 gas is blended with nitrogen gas. CO2 / nitrogen blends are used to allow a higher operating pressure in complex dispensing systems.
Nitrogen is used under high pressure when dispensing dry stouts (such as Guinness) and other creamy beers because it displaces CO2 to (artificially) form a rich tight head and a less carbonated taste. This makes the beer feel smooth on the palate and gives a foamy appearance. Premixed bottled gas for creamy beers is usually 75% nitrogen and 25% CO2. This premixed gas which only works well with creamy beers is often referred to as Guinness Gas, Beer Gas, or Aligal (an Air Liquide brand name). Using "Beer Gas" with other beer styles can cause the last 5% to 10% of the beer in each keg to taste very flat and lifeless. In the UK, the term "keg beer" would imply the beer is pasteurised, in contrast to unpasteurised cask ale. Some of the newer microbreweries may offer a nitro keg stout which is filtered but not pasteurized.
Cask beer should be stored and served at a cellar temperature of . Once a cask is opened, it should be consumed within three days. Keg beer is given additional cooling just prior to being served either by flash coolers or a remote cooler in the cellar. This chills the beer to temperatures between .
The words "draft" and "draught" have been used as marketing terms to describe canned or bottled beers, implying that they taste and appear like beers from a cask or keg. Commercial brewers use this as a marketing tool although it is incorrect to call any beer not drawn from a cask or keg "draught". Two examples are Miller Genuine Draft, a pale lager which is produced using a cold filtering system, and Guinness stout in patented "Draught-flow" cans and bottles. Guinness is an example of beers that use a nitrogen widget to create a smooth beer with a dense head. Guinness has recently replaced the widget system from their bottled "draught" beer with a coating of cellulose fibres on the inside of the bottle. Statements indicate a new development in bottling technology that enables the mixture of nitrogen and carbon dioxide to be present in the beer without using a widget, making it according to Guinness "more drinkable" from the bottle.
In some countries, such as Japan, the term "draft" applied to canned or bottled beer indicates that the beer is not pasteurized (though it may be filtered), giving it a fresher taste but shorter shelf-life than conventional packaged beers. | https://en.wikipedia.org/wiki?curid=8387 |
Controlled Substances Act
The Controlled Substances Act (CSA) is the statute establishing federal U.S. drug policy under which the manufacture, importation, possession, use, and distribution of certain substances is regulated. It was passed by the 91st United States Congress as Title II of the Comprehensive Drug Abuse Prevention and Control Act of 1970 and signed into law by President Richard Nixon. The Act also served as the national implementing legislation for the Single Convention on Narcotic Drugs.
The legislation created five schedules (classifications), with varying qualifications for a substance to be included in each. Two federal agencies, the Drug Enforcement Administration (DEA) and the Food and Drug Administration (FDA), determine which substances are added to or removed from the various schedules, although the statute passed by Congress created the initial listing. Congress has sometimes scheduled other substances through legislation such as the Hillory J. Farias and Samantha Reid Date-Rape Prevention Act of 2000, which placed gamma hydroxybutyrate (GHB) in Schedule I and sodium oxybate (the isolated sodium salt in GHB) in Schedule III when used under an FDA NDA or IND. Classification decisions are required to be made on criteria including potential for abuse (an undefined term), currently accepted medical use in treatment in the United States, and international treaties.
The nation first outlawed addictive drugs in the early 1900s and the International Opium Convention helped lead international agreements regulating trade. The Food and Drugs Act of 1906 was the beginning of over 200 laws concerning public health and consumer protections. Others were the Federal Food, Drug, and Cosmetic Act (1938), and the Kefauver Harris Amendment of 1962.
In 1969, President Richard Nixon announced that the Attorney General, John N. Mitchell, was preparing a comprehensive new measure to more effectively meet the narcotic and dangerous drug problems at the federal level by combining all existing federal laws into a single new statute. With the help of White House Counsel head, John Dean; the Executive Director of the Shafer Commission, Michael Sonnenreich; and the Director of the BNDD, John Ingersoll creating and writing the legislation, Mitchell was able to present Nixon with the bill.
The CSA not only combined existing federal drug laws and expanded their scope, but it also changed the nature of federal drug law policies and expanded Federal law enforcement pertaining to controlled substances.
Title II, Part F of the Comprehensive Drug Abuse Prevention and Control Act of 1970 established the National Commission on Marijuana and Drug Abuse—known as the Shafer Commission after its chairman, Raymond P. Shafer—to study cannabis abuse in the United States. During his presentation of the commission's First Report to Congress, Sonnenreich and Shafer recommended the decriminalization of marijuana in small amounts, with Shafer stating,
Rufus King notes that this stratagem was similar to that used by Harry Anslinger when he consolidated the previous anti-drug treaties into the Single Convention and took the opportunity to add new provisions that otherwise might have been unpalatable to the international community. According to David T. Courtwright, "the Act was part of an omnibus reform package designed to rationalize, and in some respects to liberalize, American drug policy." (Courtwright noted that the Act became, not libertarian, but instead repressionistic to the point of tyrannical, in its intent.) It eliminated mandatory minimum sentences and provided support for drug treatment and research. King notes that the rehabilitation clauses were added as a compromise to Senator Jim Hughes, who favored a moderate approach. The bill, as introduced by Senator Everett Dirksen, ran to 91 pages. While it was being drafted, the Uniform Controlled Substances Act, to be passed by state legislatures, was also being drafted by the Department of Justice; its wording closely mirrored the Controlled Substances Act.
Since its enactment in 1970, the Act has been amended numerous times:
The Controlled Substances Act consists of two subchapters. Subchapter I defines Schedules I-V, lists chemicals used in the manufacture of controlled substances, and differentiates lawful and unlawful manufacturing, distribution, and possession of controlled substances, including possession of Schedule I drugs for personal use; this subchapter also specifies the dollar amounts of fines and durations of prison terms for violations. Subchapter II describes the laws for exportation and importation of controlled substances, again specifying fines and prison terms for violations.
The Drug Enforcement Administration was established in 1973, combining the Bureau of Narcotics and Dangerous Drugs (BNDD) and Customs' drug agents. Proceedings to add, delete, or change the schedule of a drug or other substance may be initiated by the DEA, the Department of Health and Human Services (HHS), or by petition from any interested party, including the manufacturer of a drug, a medical society or association, a pharmacy association, a public interest group concerned with drug abuse, a state or local government agency, or an individual citizen. When a petition is received by the DEA, the agency begins its own investigation of the drug.
The DEA also may begin an investigation of a drug at any time based upon information received from laboratories, state and local law enforcement and regulatory agencies, or other sources of information. Once the DEA has collected the necessary data, the Deputy Administrator of DEA, requests from HHS a scientific and medical evaluation and recommendation as to whether the drug or other substance should be controlled or removed from control. This request is sent to the Assistant Secretary of Health of HHS. Then, HHS solicits information from the Commissioner of the Food and Drug Administration and evaluations and recommendations from the National Institute on Drug Abuse and, on occasion, from the scientific and medical community at large. The Assistant Secretary, by authority of the Secretary, compiles the information and transmits back to the DEA a medical and scientific evaluation regarding the drug or other substance, a recommendation as to whether the drug should be controlled, and in what schedule it should be placed.
The HHS recommendation on scheduling is binding to the extent that if HHS recommends, based on its medical and scientific evaluation, that the substance not be controlled, then the DEA may not control the substance. Once the DEA has received the scientific and medical evaluation from HHS, the DEA Administrator evaluates all available data and makes a final decision whether to propose that a drug or other substance be controlled and into which schedule it should be placed. Under certain circumstances, the Government may temporarily schedule a drug without following the normal procedure. An example is when international treaties require control of a substance. In addition, allows the Attorney General to temporarily place a substance in Schedule I "to avoid an imminent hazard to the public safety". Thirty days' notice is required before the order can be issued, and the scheduling expires after a year; however, the period may be extended six months if rulemaking proceedings to permanently schedule the drug are in progress. In any case, once these proceedings are complete, the temporary order is automatically vacated. Unlike ordinary scheduling proceedings, such temporary orders are not subject to judicial review.
The CSA also creates a closed system of distribution for those authorized to handle controlled substances. The cornerstone of this system is the registration of all those authorized by the DEA to handle controlled substances. All individuals and firms that are registered are required to maintain complete and accurate inventories and records of all transactions involving controlled substances, as well as security for the storage of controlled substances.
The Congressional findings in 21 USC §§ , , and state that a major purpose of the CSA is to "enable the United States to meet all of its obligations" under international treaties. The CSA bears many resemblances to these Conventions. Both the CSA and the treaties set out a system for classifying controlled substances in several schedules in accordance with the binding scientific and medical findings of a public health authority. Under of the CSA, that authority is the Secretary of Health and Human Services (HHS). Under Article 3 of the Single Convention and Article 2 of the Convention on Psychotropic Substances, the World Health Organization is that authority.
The domestic and international legal nature of these treaty obligations must be considered in light of the supremacy of the United States Constitution over treaties or acts and the equality of treaties and Congressional acts. In "Reid v. Covert" the Supreme Court of the United States addressed both these issues directly and clearly holding:
According to the Cato Institute, these treaties only bind (legally obligate) the United States to comply with them as long as that nation agrees to remain a state party to these treaties. The U.S. Congress and the President of the United States have the absolute sovereign right to withdraw from or abrogate at any time these two instruments, in accordance with said nation's Constitution, at which point these treaties will cease to bind that nation in any way, shape, or form.
A provision for automatic compliance with treaty obligations is found at , which also establishes mechanisms for amending international drug control regulations to correspond with HHS findings on scientific and medical issues. If control of a substance is mandated by the Single Convention, the Attorney General is required to "issue an order controlling such drug under the schedule he deems most appropriate to carry out such obligations," without regard to the normal scheduling procedure or the findings of the HHS Secretary. However, the Secretary has great influence over any drug scheduling proposal under the Single Convention, because requires the Secretary the power to "evaluate the proposal and furnish a recommendation to the Secretary of State which shall be binding on the representative of the United States in discussions and negotiations relating to the proposal."
Similarly, if the United Nations Commission on Narcotic Drugs adds or transfers a substance to a schedule established by the Convention on Psychotropic Substances, so that current U.S. regulations on the drug do not meet the treaty's requirements, the Secretary is required to issue a recommendation on how the substance should be scheduled under the CSA. If the Secretary agrees with the Commission's scheduling decision, he can recommend that the Attorney General initiate proceedings to reschedule the drug accordingly. If the HHS Secretary disagrees with the UN controls, however, the Attorney General must temporarily place the drug in Schedule IV or V (whichever meets the minimum requirements of the treaty) and exclude the substance from any regulations not mandated by the treaty, while the Secretary is required to request that the Secretary of State take action, through the Commission or the UN Economic and Social Council, to remove the drug from international control or transfer it to a different schedule under the Convention. The temporary scheduling expires as soon as control is no longer needed to meet international treaty obligations.
This provision was invoked in 1984 to place Rohypnol (flunitrazepam) in Schedule IV. The drug did not then meet the Controlled Substances Act's criteria for scheduling; however, control was required by the Convention on Psychotropic Substances. In 1999, an FDA official explained to Congress:
The Cato Institute's "Handbook for Congress" calls for repealing the CSA, an action that would likely bring the United States into conflict with international law, were the United States not to exercise its sovereign right to withdraw from and/or abrogate the Single Convention on Narcotic Drugs and/or the 1971 Convention on Psychotropic Substances prior to repealing the Controlled Substances Act. The exception would be if the U.S. were to claim that the treaty obligations violate the United States Constitution. Many articles in these treaties—such as Article 35 and Article 36 of the Single Convention—are prefaced with phrases such as "Having due regard to their constitutional, legal and administrative systems, the Parties shall . . ." or "Subject to its constitutional limitations, each Party shall . . ." According to former United Nations Drug Control Programme Chief of Demand Reduction Cindy Fazey, "This has been used by the USA not to implement part of article 3 of the 1988 Convention, which prevents inciting others to use narcotic or psychotropic drugs, on the basis that this would be in contravention of their constitutional amendment guaranteeing freedom of speech".
There are five different schedules of controlled substances, numbered IV. The CSA describes the different schedules based on three factors:
The following table gives a summary of the different schedules.
Placing a drug or other substance in a certain schedule or removing it from a certain schedule is primarily based on 21 USC §§ , , , , , , and . Every schedule otherwise requires finding and specifying the "potential for abuse" before a substance can be placed in that schedule. The specific classification of any given drug or other substance is usually a source of controversy, as is the purpose and effectiveness of the entire regulatory scheme.
Some have argued that this is an important exemption, since alcohol and tobacco are two of the most widely used drugs in the United States. Also of significance, the exclusion of alcohol includes wine which is sacramentally used by many major religious denominations in the United States.
Schedule I substances are described as those that have the following findings:
No prescriptions may be written for Schedule I substances, and such substances are subject to production quotas which the DEA imposes.
Under the DEA's interpretation of the CSA, a drug does not necessarily have to have the same "high potential for abuse" as heroin, for example, to merit placement in Schedule I:
Drugs listed in this control schedule include:
Schedule II substances are those that have the following findings:
Except when dispensed directly to an ultimate user by a practitioner other than a pharmacist, no controlled substance in Schedule II, which is a prescription drug as determined under the Federal Food, Drug, and Cosmetic Act (21 USC 301 "et seq."), may be dispensed without the written or electronically transmitted (21 CFR 1306.08) prescription of a practitioner, except that in emergency situations, as prescribed by the Secretary by regulation after consultation with the Attorney General, such drug may be dispensed upon oral prescription in accordance with section 503(b) of that Act (21 USC 353 (b)). With exceptions, an original prescription is always required even though faxing in a prescription in advance to a pharmacy by a prescriber is allowed. Prescriptions shall be retained in conformity with the requirements of section 827 of this title. No prescription for a controlled substance in Schedule II may be refilled. Notably no emergency situation provisions exist outside the Controlled Substances Act's "closed system" although this closed system may be unavailable or nonfunctioning in the event of accidents in remote areas or disasters such as hurricanes and earthquakes. Acts which would widely be considered morally imperative remain offenses subject to heavy penalties.
These drugs vary in potency: for example fentanyl is about 80 times as potent as morphine (heroin is roughly two times as potent). More significantly, they vary in nature. Pharmacology and CSA scheduling have a weak relationship.
Because refills of prescriptions for Schedule II substances are not allowed, it can be burdensome to both the practitioner and the patient if the substances are to be used on a long-term basis. To provide relief, in 2007, was amended (at ) to allow practitioners to write up to three prescriptions at once, to provide up to a 90-day supply, specifying on each the earliest date on which it may be filled.
Drugs in this schedule include:
Schedule III substances are those that have the following findings:
Except when dispensed directly by a practitioner, other than a pharmacist, to an ultimate user, no controlled substance in Schedule III or IV, which is a prescription drug as determined under the Federal Food, Drug, and Cosmetic Act (21 USC 301 "et seq."), may be dispensed without a written, electronically transmitted, or oral prescription in conformity with section 503(b) of that Act (21 USC 353 (b)). Such prescriptions may not be filled or refilled more than six months after the date thereof or be refilled more than five times after the date of the prescription unless renewed by the practitioner. A prescription for controlled substances in Schedules III, IV, and V issued by a practitioner, may be communicated either orally, in writing, electronically transmitted or by facsimile to the pharmacist, and may be refilled if so authorized on the prescription or by call-in. Control of wholesale distribution is somewhat less stringent than Schedule II drugs. Provisions for emergency situations are less restrictive within the "closed system" of the Controlled Substances Act than for Schedule II though no schedule has provisions to address circumstances where the closed system is unavailable, nonfunctioning or otherwise inadequate.
Drugs in this schedule include:
Placement on schedules; findings required
Schedule IV substances are those that have the following findings:
Control measures are similar to Schedule III. Prescriptions for Schedule IV drugs may be refilled up to five times within a six-month period. A prescription for controlled substances in Schedules III, IV, and V issued by a practitioner, may be communicated either orally, in writing, electronically transmitted or by facsimile to the pharmacist, and may be refilled if so authorized on the prescription or by call-in.
Drugs in this schedule include:
Schedule V substances are those that have the following findings:
No controlled substance in Schedule V which is a drug may be distributed or dispensed other than for a medical purpose. A prescription for controlled substances in Schedules III, IV, and V issued by a practitioner, may be communicated either orally, in writing, electronically transmitted or by facsimile to the pharmacist, and may be refilled if so authorized on the prescription or by call-in.
Drugs in this schedule include:
The Controlled Substances Act also provides for federal regulation of precursors used to manufacture some of the controlled substances. The DEA list of chemicals is actually modified when the United States Attorney General determines that illegal manufacturing processes have changed.
In addition to the CSA, due to pseudoephedrine (PSE) and ephedrine being widely used in the manufacture of methamphetamine, the U.S. Congress passed the Methamphetamine Precursor Control Act which places restrictions on the sale of any medicine containing pseudoephedrine. That bill was then superseded by the Combat Methamphetamine Epidemic Act of 2005, which was passed as an amendment to the Patriot Act renewal and included wider and more comprehensive restrictions on the sale of PSE-containing products. This law requires customer signature of a "log-book" and presentation of valid photo ID in order to purchase PSE-containing products from all retailers.
Additionally, the law restricts an individual to the retail purchase of no more than three packages or 3.6 grams of such product per day per purchase – and no more than 9 grams in a single month. A violation of this statute constitutes a misdemeanor. Retailers now commonly require PSE-containing products to be sold behind the pharmacy or service counter. This affects many preparations which were previously available over-the-counter without restriction, such as Actifed and its generic equivalents.
There has been criticism against the schedule classifications of the listed drugs and substances in the CSA, citing undefined terms.
Some criticism has arisen due to research that has found several substances on the list of Schedule I substances to have actual accepted medical uses and low abuse potential, despite the requirement for a Schedule I listing mandating that any substance so scheduled have both a high potential for abuse and no accepted medical use. One such example is the legalization of cannabis in some capacity in currently 33 states in the United States.
Similar legislation outside of the United States: | https://en.wikipedia.org/wiki?curid=7727 |
Captain America
Captain America is a fictional superhero appearing in American comic books published by Marvel Comics. Created by cartoonists Joe Simon and Jack Kirby, the character first appeared in "Captain America Comics" #1 (cover dated March 1941) from Timely Comics, a predecessor of Marvel Comics. Captain America was designed as a patriotic supersoldier who often fought the Axis powers of World War II and was Timely Comics' most popular character during the wartime period. The popularity of superheroes waned following the war, and the "Captain America" comic book was discontinued in 1950, with a short-lived revival in 1953. Since Marvel Comics revived the character in 1964, Captain America has remained in publication.
The character wears a costume bearing an American flag motif, and he utilizes a nearly indestructible shield that he throws as a projectile. Captain America is the alter ego of Steve Rogers, a frail young man enhanced to the peak of human perfection by an experimental serum to aid the United States government's efforts in World War II. Near the end of the war, he was trapped in ice and survived in suspended animation until he was revived in modern times. Although Captain America often struggles to maintain his ideals as a man out of his time, he remains a highly respected figure in his community, which includes becoming the long-time leader of the Avengers.
Captain America was the first Marvel Comics character to appear in media outside comics with the release of the 1944 movie serial, "Captain America". Since then, the character has been featured in other films and television series. In the Marvel Cinematic Universe (MCU), the character is portrayed by Chris Evans.
Captain America was ranked sixth on IGN's "Top 100 Comic Book Heroes of All Time" in 2011, second in their list of "The Top 50 Avengers" in 2012, and second in their "Top 25 best Marvel superheroes" list in 2014.
In 1940, writer Joe Simon conceived the idea for Captain America and made a sketch of the character in costume. "I wrote the name 'Super American' at the bottom of the page," Simon said in his autobiography, and then decided:
Simon recalled in his autobiography that Timely Comics publisher Martin Goodman gave him the go-ahead and directed that a Captain America solo comic book series be published as soon as possible. Needing to fill a full comic with primarily one character's stories, Simon did not believe that his regular creative partner, artist Jack Kirby, could handle the workload alone:
Al Lieberman would ink that first issue, which was lettered by Simon and Kirby's regular letterer, Howard Ferguson.
Simon said Captain America was a consciously political creation; he and Kirby were morally repulsed by the actions of Nazi Germany in the years leading up to the United States' involvement in World War II and felt war was inevitable: "The opponents to the war were all quite well organized. We wanted to have our say too."
Captain America Comics #1 — cover-dated March 1941 and on sale December 20, 1940, a year before the attack on Pearl Harbor, but a full year into World War II — showed the protagonist punching Nazi leader Adolf Hitler; it sold nearly one million copies. While most readers responded favorably to the comic, some took objection. Simon noted, "When the first issue came out we got a lot of ... threatening letters and hate mail. Some people really opposed what Cap stood for." The threats, which included menacing groups of people loitering out on the street outside of the offices, proved so serious that police protection was posted with New York Mayor Fiorello La Guardia personally contacting Simon and Kirby to give his support.
Though preceded as a "patriotically themed superhero" by MLJ's The Shield, Captain America immediately became the most prominent and enduring of that wave of superheroes introduced in American comic books prior to and during World War II, as evidenced by the unusual move at the time of premiering the character in his own title instead of an anthology title first. This popularity drew the attention and a complaint from MLJ that the character's triangular shield too closely resembled the chest symbol of their Shield character. In response, Goodman had Simon and Kirby create a distinctive round shield for issue 2, which went on to become an iconic element of the character. With his sidekick Bucky, Captain America faced Nazis, Japanese, and other threats to wartime America and the Allies. Stanley Lieber, now better known as Stan Lee, contributed to the character in issue #3 in the filler text story "Captain America Foils the Traitor's Revenge", which introduced the character's use of his shield as a returning throwing weapon. Captain America soon became Timely's most popular character and even had a fan-club called the "Sentinels of Liberty".
Circulation figures remained close to a million copies per month after the debut issue, which outstripped even the circulation of news magazines such as "Time" during the period. The character was widely imitated by other comics publishers, with around 40 red-white-and-blue patriotic heroes debuting in 1941 alone. After the Simon and Kirby team moved to DC Comics in late 1941, having produced "Captain America Comics" through issue #10 (January 1942), Al Avison and Syd Shores became regular pencillers of the celebrated title, with one generally inking over the other. The character was featured in "All Winners Comics" #1–19 (Summer 1941 – Fall 1946), "Marvel Mystery Comics" #80–84 and #86–92, "USA Comics" #6–17 (Dec. 1942 – Fall 1945), and "All Select Comics" #1–10 (Fall 1943 – Summer 1946).
In the post-war era, with the popularity of superheroes fading, Captain America led Timely's first superhero team, the All-Winners Squad, in its two published adventures, in "All Winners Comics" #19 and #21 (Fall–Winter 1946; there was no issue #20). After Bucky was shot and wounded in a 1948 "Captain America" story, he was succeeded by Captain America's girlfriend, Betsy Ross, who became the superheroine Golden Girl. "Captain America Comics" ran until issue #73 (July 1949), at which time the series was retitled Captain America's Weird Tales for two issues, with the finale being a horror/suspense anthology issue with no superheroes.
Atlas Comics attempted to revive its superhero titles when it reintroduced Captain America, along with the original Human Torch and the Sub-Mariner, in "Young Men" #24 (Dec. 1953). Billed as "Captain America, Commie Smasher!" Captain America appeared during the next year in "Young Men" #24–28 and "Men's Adventures" #27–28, as well as in issues #76–78 of an eponymous title. Atlas' attempted superhero revival was a commercial failure, and the character's title was canceled with "Captain America" #78 (Sept. 1954).
In the Human Torch story titled "Captain America" in Marvel Comics' "Strange Tales" #114 (Nov. 1963), writer-editor Stan Lee and artist and co-plotter Jack Kirby depicted the brash young Fantastic Four member Johnny Storm, the Human Torch, in an exhibition performance with Captain America, described as a legendary World War II and 1950s superhero who has returned after many years of apparent retirement. The 18-page story ends with this Captain America revealed as an impostor: it was actually the villain the Acrobat, a former circus performer the Torch had defeated in "Strange Tales" #106, who broke two thieves out of jail, hoping to draw the police away while trying to rob the local bank. Afterward, Storm digs out an old comic book in which Captain America is shown to be Steve Rogers. A caption in the final panel says this story was a test to see if readers would like Captain America to return. According to Lee, fan response to the tryout was very enthusiastic.
Captain America was then formally reintroduced in "The Avengers" #4 (March 1964), which explained that in the final days of World War II, he had fallen from an experimental drone plane into the North Atlantic Ocean and spent decades frozen in a block of ice in a state of suspended animation. The hero found a new generation of readers as leader of that superhero team. Following the success of other Marvel characters introduced during the 1960s, Captain America was recast as a hero "haunted by past memories, and trying to adapt to 1960s society".
After then guest-starring in the feature "Iron Man" in "Tales of Suspense" #58 (Oct. 1964), Captain America gained his own solo feature in that "split book", beginning the following issue. Issue #63 (March 1965), which retold Captain America's origin, through issue #71 (Nov. 1965) was a period feature set during World War II and co-starred Captain America's Golden Age sidekick, Bucky. Kirby drew all but two of the stories in "Tales of Suspense," which became "Captain America" with #100 (April 1968); Gil Kane and John Romita Sr., each filled in once. Several stories were finished by penciller-inker George Tuska over Kirby layouts, with one finished by Romita Sr. and another by penciller Dick Ayers and inker John Tartaglione. Kirby's regular inkers on the series were Frank Giacoia (as "Frank Ray") and Joe Sinnott, though Don Heck and Golden Age Captain America artist Syd Shores inked one story each.
This series — considered "Captain America" volume one by comics researchers and historians, following the 1940s "Captain America Comics" and its 1950s numbering continuation of "Tales of Suspense" — ended with #454 (Aug. 1996).
This series was almost immediately followed by the 13-issue "Captain America" vol. 2 (Nov. 1996 – Nov. 1997, part of the "Heroes Reborn" crossover), the 50-issue "Captain America" vol. 3 (Jan. 1998 – Feb. 2002), the 32-issue "Captain America" vol. 4 (June 2002 – Dec. 2004), and "Captain America" vol. 5 (Jan. 2005 – Aug. 2011). Beginning with the 600th overall issue (Aug. 2009), "Captain America" resumed its original numbering, as if the series numbering had continued uninterrupted after #454.
As part of the aftermath of Marvel Comics' company-crossover storyline "Civil War", Steve Rogers was ostensibly killed in "Captain America" vol. 5, #25 (March 2007).
The storyline of Rogers' return began in issue #600. Rogers, who was not dead but caroming through time, returned to the present day in the six-issue miniseries "" (Sept. 2009 – March 2010).
After Rogers' return, Barnes, at Rogers' insistence, continued as Captain America, beginning in the one-shot comic "Captain America: Who Will Wield the Shield?" (Feb. 2010). While Bucky Barnes continued adventuring in the pages of "Captain America", Steve Rogers received his own miniseries ("Steve Rogers: Super-Soldier") as well as taking on the leadership position in a new "Secret Avengers" ongoing series.
Spinoff series included "Captain America Sentinel of Liberty" (Sept. 1998 – Aug. 1999) and "Captain America and the Falcon" (May 2004 – June 2005). The 1940s Captain America appeared alongside the 1940s Human Torch and Sub-Mariner in the 12-issue miniseries "Avengers/Invaders". The 2007 mini-series "Captain America: The Chosen", written by David Morrell and penciled by Mitchell Breitweiser, depicts a dying Steve Rogers' final minutes, at S.H.I.E.L.D. headquarters, as his spirit guides James Newman, a young American Marine fighting in Afghanistan. "The Chosen" is not part of the main Marvel Universe continuity.
During the "Two Americas" storyline that ran in issues #602-605, the series drew controversy for the similarity between protesters depicted in the comic and the Tea Party movement. Particularly drawing scorn was a panel of a protester holding sign that read "Tea Bag the Libs Before They Tea Bag You!" Also drawing controversy were remarks made by the Falcon implying that the crowd is racist. In his column on Comic Book Resources, Marvel Comics Editor-in-Chief Joe Quesada apologized for the sign, claiming that it was a mistake, added by the letterer at the last minute.
The character, first as agent Steve Rogers and later after resuming his identity as Captain America, appeared as a regular character throughout the 2010–2013 "Avengers" series, from issue #1 (July 2010) through its final issue #34 (January 2013). The character appeared as agent Steve Rogers as a regular character in the 2010–2013 "Secret Avengers" series, from issue #1 (July 2010) through issue #21 (March 2012); the character made guest appearances as Captain America in issues #21.1, #22–23, #35, and the final issue of the series #37 (March 2013).
Marvel stated in May 2011 that Rogers, following the public death of Bucky Barnes in the "Fear Itself" miniseries, would resume his Captain America identity in a sixth volume of "Captain America", by writer Ed Brubaker and artist Steve McNiven. The "Captain America" title continued from issue #620 featuring team up stories with Bucky (#620-#628), Hawkeye (#629-#632), Iron Man (#633–635), Namor (#635.1), and Black Widow (#636-#640), and the title ended its print run with issue #640.
Captain America is a regular character in "Uncanny Avengers" (2012), beginning with issue #1 as part of Marvel NOW!. "Captain America" vol. 7 was launched in November 2012 with a January 2013 cover date by writer Rick Remender and artist John Romita Jr..
On July 16, 2014 Marvel Comics announced that the mantle of Captain America would be passed on by Rogers (who in the most recent storyline has been turned into a 90-year-old man) to his long-time ally The Falcon, with the series being relaunched as "All-New Captain America".
Marvel announced that Rogers will become Captain America once again in the comic series "Captain America: Steve Rogers". This new series follows the events of "," in which Captain America is restored to his youthful state following an encounter with the sentient Cosmic Cube, Kobik, and his past is drastically rewritten under the instructions of the Red Skull. Afterward, Captain America plots to set himself and Hydra in a position where they can conquer America in Marvel's event "Secret Empire."
In 1966, Joe Simon sued the owners of Marvel Comics, asserting that he—not Marvel—was legally entitled to renew the copyright upon the expiration of the original 28-year term. The two parties settled out of court, with Simon agreeing to a statement that the character had been created under terms of employment by the publisher, and therefore it was work for hire owned by them.
In 1999, Simon filed to claim the copyright to Captain America under a provision of the Copyright Act of 1976, which allowed the original creators of works that had been sold to corporations to reclaim them after the original 56-year copyright term (but not the longer term enacted by the new legislation) had expired. Marvel Entertainment challenged the claim, arguing that the settlement of Simon's 1966 suit made the character ineligible for termination of the copyright transfer. Simon and Marvel settled out of court in 2003, in a deal that paid Simon royalties for merchandising and licensing use of the character.
Steven Grant Rogers was born in the Lower East Side of Manhattan, New York City, in 1920 to poor Irish immigrants, Sarah and Joseph Rogers. Joseph died when Steve was a child, and Sarah died of pneumonia while Steve was a teen. By early 1940, before America's entry into World War II, Rogers is a tall, scrawny fine arts student specializing in illustration and a comic book writer and artist.
Disturbed by the devastation of Europe by the Nazis, Rogers attempts to enlist but is rejected due to his frail body. His resolution attracts the notice of U.S. Army General Chester Phillips and "Project: Rebirth". Rogers is used as a test subject for the Super-Soldier project, receiving a special serum made by "Dr. Josef Reinstein", later retroactively changed to a code name for the scientist Abraham Erskine.
The serum is a success and transforms Steve Rogers into a nearly perfect human being with peak strength, agility, stamina, and intelligence. The success of the program leaves Erskine wondering about replicating the experiment on other human beings. The process itself has been inconsistently detailed: While in the original material Rogers is shown receiving injections of the Super-Serum, when the origin was retold in the 1960s, the Comic Code Authority had already put a veto over graphic description of drug intake and abuse, and thus the Super-Serum was retconned into an oral formula.
Erskine refused to write down every crucial element of the treatment, leaving behind a flawed, imperfect knowledge of the steps. Thus, when the Nazi spy Heinz Kruger killed him, Erskine's method of creating new Super-Soldiers died. Captain America, in his first act after his transformation, avenges Erskine. In the 1941 origin story and in "Tales of Suspense" #63, Kruger dies when running into machinery but is not killed by Rogers; in the "Captain America" #109 and #255 revisions, Rogers causes the spy's death by punching him into machinery.
Unable to create new Super-Soldiers and willing to hide the Project Rebirth fiasco, the American government casts Rogers as a patriotic superhero, able to counter the menace of the Red Skull as a counter-intelligence agent. He is supplied with a patriotic uniform of his own design, a bulletproof shield, a personal side arm, and the codename Captain America, while posing as a clumsy infantry private at Camp Lehigh in Virginia. He forms a friendship with the camp's teenage mascot, James Buchanan "Bucky" Barnes.
Barnes learns of Rogers' dual identity and offers to keep the secret if he can become Captain America's sidekick. During their adventures, Franklin D. Roosevelt presents Captain America with a new shield, forged from an alloy of steel and vibranium, fused by an unknown catalyst, so effective that it replaces his own firearm. Throughout World War II, Captain America and Bucky fight the Nazi menace both on their own and as members of the superhero team the Invaders as seen in the 1970s comic of the same name. Captain America fights in numerous battles in World War II, primarily as a member of 1st Battalion, 26th Infantry Regiment "Blue Spaders". Captain America battles a number of criminal menaces on American soil, including a wide variety of costumed villains: the Wax Man, the Hangman, the Fang, the Black Talon, and the White Death, among others.
In addition to Bucky, Captain America was occasionally assisted by the Sentinels of Liberty. Sentinels of Liberty was the title given to members of the "Captain America Comics" fan club who Captain America sometimes addressed as an aside, or as characters in the "Captain America Comics" stories.
In late April 1945, during the closing days of World War II, Captain America and Bucky try to stop the villainous Baron Zemo from destroying an experimental drone plane. Zemo launches the plane with an armed explosive on it with Rogers and Barnes in hot pursuit. The pair reaches the plane just before takeoff. When Bucky tries to defuse the bomb, it explodes in mid-air. Rogers is hurled into the freezing waters of the North Atlantic. Both are presumed dead, though it is later revealed that neither had died.
Captain America appeared in comics for the next few years, changing from World War II-era hero fighting the Nazis to confronting the United States' newest enemy, Communism. The revival of the character in the mid-1950s was short-lived, and events during that time period are later retconned to show that multiple people operated using the code name to explain the changes in the character. These post World War II successors are listed as William Naslund and Jeffrey Mace. They are assisted by Fred Davis continuing the role of Bucky.
The last of these other official Captains, William Burnside, was a history graduate enamored with the Captain America mythos, having his appearance surgically altered to resemble Rogers and legally changing his name to "Steve Rogers", becoming the new "1950s Captain America". He administered to himself and his pupil James "Jack" Monroe a flawed, incomplete copy of the Super-Serum, which made no mention about the necessary Vita-Ray portion of the treatment. As a result, while Burnside and Monroe became the new Captain America and Bucky, they became violently paranoid, often raving about innocent people being communist sympathizers during the height of the Red Scare of the 1950s. Their insanity forced the U.S. government to place them in indefinite cryogenic storage until they could be cured of their mental illness. Monroe would later be cured and assume the Nomad identity.
Years later, the superhero team the Avengers discovers Steve Rogers' body in the North Atlantic. After he revives, they piece together that Rogers has been preserved in a block of ice since 1945, surviving because of his enhancements from Project: Rebirth. The block began to melt after the Sub-Mariner, enraged that an Inuit tribe is worshipping the frozen figure, throws it into the ocean. Rogers accepts membership in the Avengers, and his experience in individual combat service and his time with the Invaders makes him a valuable asset. He quickly assumes leadership and has typically returned to that position throughout the team's history.
Captain America is plagued by guilt for having been unable to prevent Bucky's death. Although he takes the young Rick Jones (who closely resembles Bucky) under his tutelage, he refuses for some time to allow Jones to take up the Bucky identity, not wishing to be responsible for another youth's death. Insisting that his hero move on from that loss, Jones convinces Rogers to let him don the Bucky costume, but this partnership lasts only a short time; a disguised Red Skull, impersonating Rogers with the help of the Cosmic Cube, drives Jones away.
Rogers reunites with his old war comrade Nick Fury, who is similarly well-preserved due to the "Infinity Formula". As a result, Rogers regularly undertakes missions for the security agency S.H.I.E.L.D., for which Fury is public director. Through Fury, Rogers befriends Sharon Carter, a S.H.I.E.L.D. agent, with whom he eventually begins a romantic relationship.
Rogers later meets and trains Sam Wilson, who becomes the superhero the Falcon, the first African-American superhero in mainstream comic books. The characters established an enduring friendship and adventuring partnership, sharing the series title for some time as "Captain America and the Falcon". The two later encounter the revived but still insane 1950s Captain America. Although Rogers and the Falcon defeat the faux Rogers and Jack Monroe, Rogers becomes deeply disturbed that he could have suffered his counterpart's fate. During this period, Rogers temporarily gains super strength.
The series dealt with the Marvel Universe's version of the Watergate scandal, making Rogers so uncertain about his role that he abandons his Captain America identity in favor of one called Nomad, emphasizing the word's meaning as "man without a country". During this time, several men unsuccessfully assume the Captain America identity. Rogers eventually re-assumes it after coming to consider that the identity could be a symbol of American ideals and not its government; it's a personal conviction epitomized when he later confronted a corrupt Army officer attempting to manipulate him by appealing to his loyalty, "I'm loyal to nothing, General ... except the [American] Dream." Jack Monroe, cured of his mental instability, later takes up the Nomad alias. Sharon Carter is believed to have been killed while under the mind control of Dr. Faustus.
The 1980s included a run by writer Roger Stern and artist John Byrne. Stern had Rogers consider a run for President of the United States in "Captain America" #250 (June 1980), an idea originally developed by Roger McKenzie and Don Perlin. Stern, in his capacity as editor of the title, originally rejected the idea but later changed his mind about the concept. McKenzie and Perlin received credit for the idea on the letters page at Stern's insistence. Stern additionally introduced a new love interest, law student Bernie Rosenthal, in "Captain America" #248 (Aug. 1980).
Writer J. M. DeMatteis revealed the true face and full origin of the Red Skull in "Captain America" #298–300, and had Captain America take on Jack Monroe, Nomad, as a partner for a time. The heroes gathered by the Beyonder elect Rogers as leader during their stay on Battleworld. Homophobia is dealt with as Rogers runs into a childhood friend named Arnold Roth who is gay.
Mark Gruenwald became the writer of the series with issue #307 (July 1985) and wrote 137 issues for 10 consecutive years from until #443 (Sept. 1995), the most issues by any single author in the character's history. Gruenwald created several new foes, including Crossbones and the Serpent Society. Other Gruenwald characters included Diamondback, Super Patriot, and Demolition Man. Gruenwald explored numerous political and social themes as well, such as extreme idealism when Captain America fights the anti-nationalist terrorist Flag-Smasher; and vigilantism when he hunts the murderous Scourge of the Underworld.
Rogers receives a large back-pay reimbursement dating back to his disappearance at the end of World War II, and a government commission orders him to work directly for the U.S. government. Already troubled by the corruption he had encountered with the Nuke incident in New York City, Rogers chooses instead to resign his identity, and then takes the alias of "the Captain". A replacement Captain America, John Walker, struggles to emulate Rogers' ideals until pressure from hidden enemies helps to drive Walker insane. Rogers returns to the Captain America identity while a recovered Walker becomes the U.S. Agent.
Sometime afterward, Rogers avoids the explosion of a methamphetamine lab, but the drug triggers a chemical reaction in the Super Soldier Serum in his system. To combat the reaction, Rogers has the serum removed from his body and trains constantly to maintain his physical condition. A retcon later establishes that the serum was not a drug "per se", which would have metabolized out of his system, but in fact a virus-like organism that effected a biochemical and genetic change. This additionally explained how nemesis the Red Skull, who at the time inhabited a body cloned from Rogers' cells, has the formula in his body.
Because of his altered biochemistry, Rogers' body begins to deteriorate, and for a time he must wear a powered exoskeleton and is eventually placed again in suspended animation. During this time, he is given a transfusion of blood from the Red Skull, which cures his condition and stabilizes the Super-Soldier virus in his system. Captain America returns to crime fighting and the Avengers.
Following Gruenwald's departure from the series, Mark Waid took over and resurrected Sharon Carter as Cap's love interest. The title was then relaunched under Rob Liefeld as Cap became part of the Heroes Reborn universe for 13 issues before another relaunch restored Waid to the title in an arc that saw Cap lose his shield for a time using an energy based shield as a temporary replacement. Following Waid's run, Dan Jurgens took over and introduced new foe Protocide, a failed recipient of the Super Soldier Serum prior to the experiment that successfully created Rogers. Some time after this, Rogers' original shield was retrieved, but subtle damage sustained during the battle with the Beyonder resulted in it being shattered and a 'vibranium cancer' being triggered that would destroy all vibranium in the world, with Rogers nearly being forced to destroy the shield before a confrontation with the villain Klaw saw Klaw's attacks unwittingly repair the shield's fractured molecular bonds and negate cancer.
In the aftermath of the September 11 terrorist attacks, Rogers reveals his identity to the world and establishes a residence in the Red Hook neighborhood of Brooklyn, New York, as seen in "Captain America" vol. 4, #1–7 (June 2002 – Feb. 2003). Following the disbandment of the Avengers in the "Avengers Disassembled" story arc, Rogers, now employed by S.H.I.E.L.D., discovers Bucky is alive, having been saved and deployed by the Soviets as the Winter Soldier. Rogers resumes his on-again, off-again relationship with S.H.I.E.L.D. agent Sharon Carter. After a mass supervillain break-out of the Raft, Rogers and Tony Stark assemble a new team of Avengers to hunt the escapees.
In the 2006–2007 company-wide story arc "Civil War", Rogers opposes the new mandatory federal registration of super-powered beings, and leads the underground anti-registration movement. After significant rancor and danger to the public as the two sides clash, Captain America voluntarily surrenders and orders the Anti-Registration forces to stand down, feeling that the fight has reached a point where the principle originally cited by the anti-registration forces has been lost.
In the story arc "The Death of Captain America", Rogers is fatally shot by Sharon Carter, whose actions are manipulated by the villain Dr. Faustus. The miniseries "" #1–5 (June–Aug. 2007) examines the reaction of the stunned superhero community to Rogers' assassination, with each of the five issues focusing a different character's reaction. Bucky takes on the mantle of Captain America, per Rogers' antemortem request.
"" #1 (Aug. 2009) reveals that Rogers did not die, as the gun Sharon Carter had been hypnotized into firing at Rogers caused his consciousness to phase in and out of space and time, appearing at various points in his lifetime. Although Rogers manages to relay a message to the future by giving a time-delayed command to the Vision during the Kree-Skrull War, the Skull returns Rogers to the present, where he takes control of Rogers' mind and body. Rogers eventually regains control, and, with help from his allies, defeats the Skull. In the subsequent one-shot comic "Captain America: Who Will Wield the Shield?", Rogers formally grants Bucky his Captain America shield and asks him to continue as Captain America. The President of the United States grants Rogers a full pardon for his anti-registration actions.
Following the company-wide "Dark Reign" and "Siege" story arcs, the Steve Rogers character became part of the "Heroic Age" arc.
The President of the United States appoints Rogers, in his civilian identity, as ""America's top cop"" and head of the nation's security, replacing Norman Osborn as the tenth "Executive Director of S.H.I.E.L.D.". The Superhuman Registration Act is repealed and Rogers re-establishes the superhero team the Avengers, spearheaded by Iron Man, Thor, and Bucky as Captain America. In the miniseries "Steve Rogers: Super Soldier", he encounters Jacob Erskine, the grandson of Professor Abraham Erskine and the son of Tyler Paxton, one of Rogers' fellow volunteers in the Super-Soldier program. Shortly afterward, Rogers becomes leader of the Secret Avengers, a black-ops superhero team.
During the "Fear Itself" storyline, Steve Rogers is present when the threat of the Serpent is known. Following the apparent death of Bucky at the hands of Sin (in the form of Skadi), Steve Rogers ends up changing into his Captain America uniform. When the Avengers and the New Avengers are fighting Skadi, the Serpent ends up joining the battle and breaks Captain America's shield with his bare hands. Captain America and the Avengers teams end up forming a militia for a last stand against the forces of the Serpent. When it comes to the final battle, Captain America uses Thor's hammer to fight Skadi until Thor manages to kill the Serpent. In the aftermath of the battle, Iron Man presents him with his reforged shield, now stronger for its uru-infused enhancements despite the scar it bears. It is then revealed that Captain America, Nick Fury, and Black Widow are the only ones who know that Bucky actually survived the fight with Skadi as Bucky resumes his identity as Winter Soldier.
In the "Avengers vs. X-Men" story arc, Captain America attempts to apprehend Hope Summers of the X-Men. She is the targeted vessel for the Phoenix Force, a destructive cosmic entity. Captain America believes that this Phoenix Force is too dangerous to entrust in one person and seeks to prevent Hope from having it. Cyclops and the X-Men believe that the Phoenix Force will save their race, and oppose Captain America's wishes. The result is a series of battles that eventually take both teams to the blue area of the moon. The Phoenix Force eventually possesses the five X-Men present, leaving the Avengers at an extreme disadvantage. The "Phoenix Five", who become corrupted by the power of the Phoenix, are eventually defeated and scattered, with Cyclops imprisoned for turning the world into a police state and murdering Charles Xavier after being pushed too far, only for him to note that, in the end, he was proven right about the Phoenix's intentions. From there, Captain America proceeds to assemble the Avengers Unity Squad, a new team of Avengers composed of both classic Avengers and X-Men.
After Cyclops was incarcerated, and Steve accepted the Avengers should have done more to help mutants, and allowed the world to hate them, he started planning a new sub-team of Avengers in the hopes of unifying mutant and humankind alike. He chose Havok to lead his team and become the new face to represent mutants as Professor X and Cyclops once were.
Their first threat was the return of the Red Skull- more specifically, a clone of the Skull created in 1942 and kept in stasis in the event of the original's death- who usurped Professor X's body to provide himself with telepathic powers, which he would use to provoke citizens of New York into a mass assault against mutants, or anyone who could be one, and force the Scarlet Witch and Rogue to allow themselves to be attacked. With the help of the S-Man Honest John, he managed to even manipulate Thor.
The Red Skull's skills were still erratic, and could not completely control Captain America, an attack against him was enough of a distraction to lose control of Rogue and the Scarlet Witch. After being overpowered by the rest of the Uncanny Avengers, the Red Skull escapes, but promises to return. In the aftermath, both Rogue and the Scarlet Witch joined the team.
During a battle with an enemy called the Iron Nail, the Super Soldier Serum within Rogers's body was neutralized, causing him to age rapidly to match his chronological age of over 90 years. No longer able to take part in field missions but retaining his sharp mind, Rogers decided to take on a role as mission coordinator, organizing the Avengers' plans of attack from the mansion, while appointing Sam Wilson as his official "replacement" as Captain America. When various Avengers and X-Men were inverted into villains and several villains inverted into heroism due to a miscast spell by the Scarlet Witch and Doctor Doom, Rogers not only coordinated the efforts of Spider-Man and the inverted villains, now called the "Astonishing Avengers", but also donned his old armor to battle the inverted Falcon, until the heroes and villains could be returned to normal with the aid of the White Skull (the inverted Red Skull).
During the "Time Runs Out" storyline, Steve Rogers wears armor when he confronts Iron Man. The ensuing fight between the two old friends led Steve Rogers to force Iron Man to admit that he had lied to him and all of their allies, when he had known about the incursions between alternate Earths all along, but Iron Man also confessed that he wouldn't change a thing. The final incursion started and Earth-1610 started approaching Earth-616 while Iron Man and Steve Rogers kept fighting. Earth-1610's S.H.I.E.L.D. launched a full invasion to destroy Earth-616, where Tony Stark and Steve Rogers were crushed by a Helicarrier.
As part of the "All-New, All-Different Marvel", Steve Rogers became the new Chief of Civilian Oversight for S.H.I.E.L.D. He returned to the Uncanny Avengers where the team is now using the Schaefer Theater as their headquarters.
Steve Rogers later has an encounter with an alternate Logan from Earth-807128. After defeating Logan and bringing him to Alberta, Canada, Rogers tried to "reassure" Logan that this was not "his" past by showing him the adamantium-frozen body of Earth-616's Logan. This sight reminds Logan of the need to enjoy being alive rather than brooding over the ghosts of his past. Although he told Steve Rogers what he had experienced in his timeline, Logan declined Steve's offer of help.
During the 2016 "" storyline, Steve Rogers learns from Rick Jones that S.H.I.E.L.D. has established Pleasant Hill, a gated community where they use Kobik to transform villains into ordinary citizens. When Rogers is brought to Pleasant Hill, he confronts Maria Hill about the Kobik project. Their argument is interrupted when Baron Helmut Zemo and Fixer restore the inmates to normal. After Hill is injured, Rogers convinces Zemo to let Hill get medical attention. Rogers is then escorted to Dr. Erik Selvig's clinic by Father Patrick. Selvig tells Rogers that Kobik is at the Pleasant Hill Bowling Alley. During an attempt to reason with Kobik, Rogers is attacked by Crossbones. Before Rogers can be killed, Kobik uses her abilities to restore him back to his prime. Declaring that "It's good to be back," Steve defeats Crossbones as Captain America and the Winter Soldier catch up with him. They resume their search for Kobik, and discover that Baron Zemo had Fixer invent a device that would make Kobik subservient to them. Rogers rallies the heroes so that they can take the fight to Zemo. In the aftermath of the incident, Steve and Sam plan to keep what happened at Pleasant Hill under wraps for the time being.
In "Captain America: Steve Rogers" #1 (July 2016), the final panel apparently revealed that Rogers has been a Hydra double-agent since his early youth. This is subsequently revealed to be the result of Kobik's restoration of Rogers' youth, as she had been taught by the Red Skull that Hydra was good for the world, and having the mind of a four-year-old child, Kobik changed reality so that Rogers would be the greatest man he could be: believing Hydra to be good, Kobik permanently altered his memories so that Rogers believed that he had always been a member of Hydra. Some of Rogers' original heroic attributes remain intact, such as covering the death of another Hydra member within S.H.I.E.L.D., Erik Selvig, as well as knowing of Jack Flag's tragic life and his immortality, which is why Steve pushes him from Zemo's airplane (resulting in coma, not death). Additionally, it is revealed that Rogers' abusive father, Joseph, was actually killed by Hydra, and that Hydra deceived him into thinking Joseph died of a heart attack. It is also revealed that Rogers witnessed his mother, Sarah, being killed by Sinclair's Hydra goons and kidnapped him, which is the reason why Steve held a grudge towards Hydra's evilness and plans to kill the Red Skull's clone and restore Hydra's lost honor. As part of his long-term plans, Steve further compromised Sam Wilson's current image as 'the' Captain America by using his greater familiarity with the shield to deliberately put Wilson in a position where he would be unable to use the shield to save a senator from Flag-Smasher, with the final goal of demoralizing Sam to the point where he will return the shield to Rogers of his own free will, not wanting to kill Wilson and risk creating a martyr.
During the 2016 "Civil War II" storyline, with the discovery of new Inhuman Ulysses – who has the ability to "predict" the future by calculating complex patterns – Rogers has set out to prevent Ulysses from learning of his true plans and allegiance. Rogers does this by "forcing" certain predictions on him, such as anonymously providing Bruce Banner with new gamma research to provoke a vision that would drive the Avengers to kill Banner, although this plan has apparently backfired with a recent vision showing the new Spider-Man standing over the dead Steve Rogers. Despite this revelation, Rogers presents himself as the voice of reason by allowing Spider-Man to flee with Thor. This inspires doubt in Tony Stark for his current stance by suggesting that he is just acting against Danvers because he does not like being top dog. He then goes to Washington, D.C., the location seen in Ulysses' vision, to talk to Spider-Man, who was trying to understand the vision like he was. When Captain Marvel attempts to arrest Spider-Man, Tony, wearing the War Machine armor, confronts her and the two begin to fight.
Later, Rogers goes to Sokovia and joins forces with Black Widow to liberate freedom fighters from a prison so they can reclaim their country. After that, he goes to his base where Doctor Selvig expresses concern of his plan to kill the Red Skull. He then reveals that he has Baron Zemo in a cell, planning to recruit him. He eventually kills the Skull after the villain is captured by the Unity Squad and the Xavier brain fragment extracted by the Beast, Rogers throwing the Skull out of a window over a cliff after Sin and Crossbones affirm their new allegiance to Rogers.
In the 2017 "Secret Empire" storyline, Rogers, as the head of S.H.I.E.L.D, uses a subsequent alien invasion and a mass supervillain assault in order to seize control of the United States. He neutralizes the superheroes that might oppose him, and seeks the Cosmic Cube to bring about a reality in which Hydra won World War II. When Rick smuggles information about the Cube's rewriting of Rogers' reality to the remaining free Avengers, a disheveled, bearded man in a torn World War II army uniform appears who introduces himself as Steve Rogers. As the Avengers and Hydra search for fragments of the shattered Cube, it is revealed that this amnesic Steve Rogers is actually a manifestation of Rogers existing within the Cube itself, created by Kobik's memories of Rogers before he was converted to Hydra, as she comes to recognize that her decision to 'rewrite' Rogers as an agent of Hydra was wrong. Although Hydra Rogers is able to mostly reassemble the Cosmic Cube, Sam Wilson and Bucky are able to use a fragment of the cube to restore the 'memory' of pre-Hydra Rogers in the Cube to corporeal existence, allowing him to defeat his Hydra self, subsequently using the Cube to undo most of the damage caused by Hydra manipulating reality even if the physical damage remains. 'Hydra Cap' continues to exist as a separate entity and is kept trapped in a prison where he is the only inmate, mocking the restored Rogers about the challenge he will face rebuilding his reputation. For himself, Rogers muses that this troubling affair has a sliver lining, that this experience will teach everyone not to place such blind trust in another.
Rogers' battle experience and training make him an expert tactician and an excellent field commander, with his teammates frequently deferring to his orders in battle. The Avengers, X-Men, Fantastic Four, and other heroes choose Rogers as their leader during the Secret Wars; Thor says that Rogers is one of the very few mortals he will take orders from, and follow "through the gates of Hades".
Rogers' reflexes and senses are extraordinarily keen. He has blended Aikido, Boxing, Judo, Karate, Jujutsu, Kickboxing, and gymnastics into his own unique fighting style and is a master of multiple martial arts. Years of practice with his near-indestructible shield make him able to aim and throw it with almost unerring accuracy. His skill with his shield is such that he can attack multiple targets in succession with a single throw or even cause a boomerang-like return from a throw to attack an enemy from behind. In canon, he is regarded by other skilled fighters as one of the best hand-to-hand combatants in the Marvel Universe, limited only by his human physique. Although the Super Soldier Serum is an important part of his strength, Rogers has shown himself still sufficiently capable against stronger opponents, even when the serum has been deactivated reverting him to his pre-Captain America physique.
Stan Lee claimed that he'd "always been fascinated by the fact that, although Captain America has the least spectacular super-power of all, the mantle of leadership falls naturally upon him, as though he was born to command... Cap is one of the hardest hero characters to write, because the writer cannot use some exotic super-power to make his episodes seem colorful... All he has to serve him are his extraordinary combat skills, his shield, and his unquenchable love for freedom and justice."
Rogers has vast U.S. military knowledge and is often shown to be familiar with ongoing, classified Defense Department operations. He is an expert in combat strategy, survival, acrobatics, parkour, military strategy, piloting, and demolitions. Despite his high profile as one of the world's most popular and recognizable superheroes, Rogers has a broad understanding of the espionage community, largely through his ongoing relationship with S.H.I.E.L.D.
Steve Rodgers is often considered to be the pinnacle of human potential and operates at peak physical performance due to his enhancement via the Super Soldier Serum. The Super Soldier Serum enhances all of his metabolic functions and prevents the build-up of fatigue poisons in his muscles, giving him endurance far in excess of an ordinary human being. This accounts for many of his extraordinary feats, including bench pressing as a warm-up and running a mile (1.6 km) in less than a minute (60 mph/97 km/h, nearly twice the maximum speed achieved by the best human sprinters). Furthermore, his enhancements are the reason why he was able to survive being frozen in suspended animation for decades. He is highly resistant to hypnosis or gases that could limit his focus. The secrets of creating a super-soldier were lost with the death of its creator, Dr. Abraham Erskine. In the ensuing decades there have been numerous attempts to recreate Erskine's treatment, only to have them end in failure. Even worse, the attempts have instead often created psychopathic supervillains of which Captain America's 1950s imitator and Nuke are the most notorious examples.
Captain America has used multiple shields throughout his history, the most prevalent of which is a nigh-indestructible disc-shaped shield made from a unique combination of Vibranium, Steel alloy, and an unknown third component that has never been duplicated called Proto-Adamantium. The shield was cast by American metallurgist Dr. Myron MacLain, who was contracted by the U.S. government, from orders of President Franklin D. Roosevelt, to create an impenetrable substance to use for tanks during World War II. This alloy was created by accident and never duplicated, although efforts to reverse-engineer it resulted in the discovery of adamantium.
Captain America often uses his shield as an offensive throwing weapon. The first instance of Captain America's trademark ricocheting shield-toss occurs in Stan Lee's first comics writing, the two-page text story "Captain America Foils the Traitor's Revenge" in "Captain America Comics" #3 (May 1941). The legacy of the shield among other comics characters includes the time-traveling mutant superhero Cable telling Captain America that his shield still exists in one of the possible futures; Cable carries it into battle and brandishes it as a symbol.
When without his trademark shield, Captain America sometimes uses other shields made from less durable metals such as steel, or even a photonic energy shield designed to mimic a vibranium matrix. Rogers, having relinquished his regular shield to Barnes, carried a variant of the energy shield which can be used with either arm, and used to either block attacks or as an improvised offensive weapon able to cut through metal with relative ease. Much like his Vibranium shield, the energy shield can be thrown, including ricocheting off multiple surfaces and returning to his hand.
Captain America's uniform is made of a fire-retardant material, and he wears a lightweight, bulletproof duralumin scale armor beneath his uniform for added protection. Originally, Rogers' mask was a separate piece of material, but an early engagement had it dislodged, thus almost exposing his identity. To prevent a recurrence of the situation, Rogers modified the mask with connecting material to his uniform, an added benefit of which was extending his armor to cover his previously exposed neck. As a member of the Avengers, Rogers has an Avengers priority card, which serves as a communications device.
Captain America has used a custom specialized motorcycle, modified by the S.H.I.E.L.D. weapons laboratory, as well as a custom-built battle van, constructed by the Wakanda Design Group with the ability to change its color for disguise purposes (red, white and blue), and fitted to store and conceal the custom motorcycle in its rear section with a frame that allows Rogers to launch from the vehicle riding it.
Captain America has faced numerous foes in over 70 years of published adventures. Many of his recurring foes embody ideologies contrary to the American values that Captain America is shown to strive for and believes in. Some examples of these opposing values are Nazism (Red Skull, Baron Zemo), neo-Nazism (Crossbones, Doctor Faustus), technocratic fascism (AIM, Arnim Zola), Communism (Aleksander Lukin), amoral capitalism (Roxxon Energy Corporation), anti-patriotism (Flag Smasher) and international and domestic terrorism (Hydra). | https://en.wikipedia.org/wiki?curid=7729 |
Christian countercult movement
The Christian countercult movement or the Christian anti-cult movement is a social movement among certain Protestant evangelical and fundamentalist and other Christian ministries ("discernment ministries") and individual activists who oppose religious sects which they consider cults.
Christian countercult-activism mainly stems from evangelicalism or fundamentalism. The countercult movement asserts that particular Christian sects are erroneous because their beliefs are not in accordance with the teachings of the Bible. It also states that a religious sect can be considered a cult if its beliefs involve a denial of any of the essential Christian teachings (such as salvation, the Trinity, Jesus himself as a person, the ministry and miracles of Jesus, his crucifixion, his resurrection, the Second Coming and the Rapture).
Countercult ministries often concern themselves with religious sects which consider themselves Christian but hold beliefs which are thought to contradict the teachings of the Bible. Such sects may include: The Church of Jesus Christ of Latter-day Saints, the Unification Church, Christian Science, and the Jehovah's Witnesses. Some Protestants classify the Catholic Church as a cult. Some also denounce non-Christian religions such as Islam, Wicca, Paganism, New Age groups, Buddhism, Hinduism and other religions.
Countercult literature usually expresses specific doctrinal or theological concerns and it also has a missionary or apologetic purpose. It presents a rebuttal by emphasizing the teachings of the Bible against the beliefs of non-fundamental Christian sects. Christian countercult activist writers also emphasize the need for Christians to evangelize to followers of cults. Some Christians also share concerns similar to those of the secular anti-cult movement.
The movement publishes its views through a variety of media, including books, magazines, and newsletters, radio broadcasting; audio and video cassette production, direct-mail appeals, proactive evangelistic encounters, professional and avocational websites, as well as lecture series, training workshops and counter-cult conferences.
Christians have applied theological criteria to assess the teachings of non-orthodox movements throughout church history. The Apostles themselves were involved in challenging the doctrines and claims of various teachers. The Apostle Paul wrote an entire epistle, Galatians, antagonistic to the teachings of a Jewish sect that claimed adherence to the teachings of both Jesus and Moses (cf. Acts 15: & Gal. 1:6-10). The First Epistle of John is devoted to countering early proto-gnostic cults that had arisen in the first century, all claiming to be "Christian" (1 Jn. 2:19).
The early Church in the post-apostolic period was much more involved in "defending its frontiers against alternative soteriologies — either by defining its own position with greater and greater exactness, or by attacking other religions, and particularly the Hellenistic mysteries." In fact, a good deal of the early Christian literature is devoted to the exposure and refutation of unorthodox theology, mystery religions and Gnostic groups. Irenaeus, Tertullian and Hippolytus of Rome were among the greatest early Christian apologetes who engaged in critical analyses of unorthodox theology, Greco-Roman pagan religions, and Gnostic groups.
In the Protestant tradition, some of the earliest writings opposing unorthodox groups (such as the Swedenborgians) can be traced back to John Wesley, Alexander Campbell and Princeton Theological Seminary theologians like Charles Hodge and B. B. Warfield. The first known usage of the term "cult" by a Protestant apologist to denote a group is heretical or unorthodox is in "Anti-Christian Cults" by A. H. Barrington, published in 1898.
Quite a few of the pioneering apologists were Baptist pastors, like I. M. Haldeman, or participants in the Plymouth Brethren, like William C. Irvine and Sydney Watson. Watson wrote a series of didactic novels like "Escaped from the Snare: Christian Science", "Bewitched by Spiritualism", and "The Gilded Lie (Millennial Dawnism)", as warnings of the dangers posed by cultic groups. Watson's use of fiction to counter the cults has been repeated by later novelists like Frank E. Peretti.
The early twentieth century apologists generally applied the words "heresy" and "sects" to groups like the Christadelphians, Mormons, Jehovah's Witnesses, Spiritualists, and Theosophists. This was reflected in several chapters contributed to the multi-volume work released in 1915 "The Fundamentals", where apologists criticised the teachings of Charles Taze Russell, Mary Baker Eddy, the Mormons and Spiritualists.
Since the 1940s, the approach of traditional Christians was to apply the meaning of "cult" such that it included those religious groups who use other scriptures beside the Bible or have teachings and practices deviating from traditional Christian teachings and practices. Some examples of sources (with published dates where known) that documented this approach are:
One of the first prominent counter-cult apologists was Jan Karel van Baalen (1890–1968), an ordained minister in the Christian Reformed Church in North America. His book, "The Chaos of Cults", which was first published in 1938, became a classic in the field as it was repeatedly revised and updated until 1962.
Historically, one of the most important protagonists of the movement was Walter Martin (1928–89), whose numerous books include the 1955 "The Rise of the Cults: An Introductory Guide to the Non-Christian Cults" and the 1965 "The Kingdom of the Cults: An Analysis of Major Cult Systems in the Present Christian Era", which continues to be influential. He became well known in conservative Christian circles through a radio program, "The Bible Answer Man", currently hosted by Hank Hanegraaff.
In "The Rise of the Cults" Martin gave the following definition of a cult:
By cultism we mean the adherence to doctrines which are pointedly contradictory to orthodox Christianity and which yet claim the distinction of either tracing their origin to orthodox sources or of being in essential harmony with those sources. Cultism, in short, is any major deviation from orthodox Christianity relative to the cardinal doctrines of the Christian faith.
As Martin's definition suggests, the countercult ministries concentrate on non-traditional groups that claim to be Christian, so chief targets have been The Church of Jesus Christ of Latter-day Saints (i.e., "Mormons"), Jehovah's Witnesses, Armstrongism, Christian Science and the Unification Church, but also smaller groups like the Swedenborgian Church
Various other conservative Christian leaders—among them John Ankerberg and Norman Geisler—have emphasized themes similar to Martin's. Perhaps more importantly, numerous other well-known conservative Christian leaders as well as many conservative pastors have accepted Martin's definition of a cult as well as his understanding of the groups to which he gave that label. Dave Breese summed up this kind of definition in these words:
A cult is a religious perversion. It is a belief and practice in the world of religion which calls for devotion to a religious view or leader centered in false doctrine. It is an organized heresy. A cult may take many forms but it is basically a religious movement which distorts or warps orthodox faith to the point where truth becomes perverted into a lie. A cult is impossible to define except against the absolute standard of the teaching of Holy Scripture.
Kenne "Ken" Silva is said by other discernment bloggers to have pioneered online discernment ministry. Ken was a Baptist pastor who ran the discernment blog Apprising. Silva wrote many blog articles about the Emerging Church, the Word of Faith Movement, Mormonism, the Jehovah's Witness, the Gay Christian Movement, and many other groups. He started his blog in 2005 and wrote there until his death in 2014.
Silva's work paved the way for other internet discernment ministries such as Pirate Christian Radio, a group of blogs and podcasts founded by Lutheran Pastor Chris Rosebrough in 2008, and Pulpit & Pen, a discernment blog founded by Baptist Pastor and polemicist J.D. Hall.
Since the 1980s the term "new religions" or "new religious movements" has slowly entered into Evangelical usage alongside the word "cult". Some book titles use both terms.
The acceptance of these alternatives to the word "cult" in Evangelicalism reflects, in part, the wider usage of such language in the sociology of religion.
The term "countercult apologetics" first appeared in Protestant Evangelical literature as a self-designation in the late 1970s and early 1980s in articles by Ronald Enroth and David Fetcho, and by Walter Martin in "Martin Speaks Out on the Cults". A mid-1980s debate about apologetic methodology between Ronald Enroth and J. Gordon Melton, led the latter to place more emphasis in his publications on differentiating the Christian countercult from the secular anti-cult. Eric Pement urged Melton to adopt the label "Christian countercult", and since the early 1990s the terms has entered into popular usage and is recognised by sociologists such as Douglas Cowan.
The only existing umbrella organization within the countercult movement in the USA is the EMNR (Evangelical Ministries to New Religions) founded in 1982 which has the evangelical Lausanne Covenant as governing document and which stresses mission, scholarship, accountability and networking.
While the greatest number of countercult ministries are found in the US, ministries exist in Australia, Brazil, Canada, Denmark, England, Ethiopia, Germany, Hungary, Italy, Mexico, New Zealand, Philippines, Romania, Russia, Sweden, and Ukraine. A comparison between the methods employed in the US and other nations discloses some similarities in emphasis, but also other nuances in emphasis. The similarities are that globally these ministries share a common concern about the evangelization of people in cults and new religions. There is also often a common thread of comparing orthodox doctrines and biblical passages with the teachings of the groups under examination. However, in some of the European and southern hemisphere contexts, confrontational methods of engagement are not always relied on, and dialogical approaches are sometimes advocated.
A group of organizations which originated within the context of established religion is working in more general fields of cult-awareness, especially in Europe. Their leaders are theologians, and they are often social ministries affiliated to big churches.
The phenomena of "cults" has also entered into the discourses of Christian missions and theology of religions. An initial step in this direction occurred in 1980 when the Lausanne Committee for World Evangelization convened a mini-consultation in Thailand. From that consultation a position paper was produced. The issue was revisited at the Lausanne Forum in 2004 with another paper. The latter paper adopts a different methodology to that advocated in 1980.
In the 1990s discussions in academic missions and theological journals indicate that another trajectory is emerging which reflects the influence of contextual missions theory. Advocates of this approach maintain that apologetics as a tool needs to be retained, but do not favour a confrontational style of engagement.
Countercult apologetics has several variations and methods employed in analysing and responding to cults. The different nuances in countercult apologetics have been discussed by John A. Saliba and Philip Johnson.
The dominant method is the emphasis on detecting unorthodox or heretical doctrines and contrasting those with orthodox interpretations of the Bible and early creedal documents. Some apologists, such as Francis J. Beckwith, have emphasised a philosophical approach, pointing out logical, epistemological and metaphysical problems within the teachings of a particular group. Another approach involves former members of cultic groups recounting their spiritual autobiographies, which highlight experiences of disenchantment with the group, unanswered questions and doubts about commitment to the group, culminating in the person's conversion to Evangelical Christianity.
Apologists like Dave Hunt in "Peace, Prosperity and the Coming Holocaust" and Hal Lindsey in "The Terminal Generation" have tended to interpret the phenomena of cults as part of the burgeoning evidence of signs that Christ's Second Advent is close at hand. Both Hunt, and Constance Cumbey, have applied a conspiracy model to interpreting the emergence of New Age spirituality and linking that to speculations about fulfilled prophecies heralding Christ's reappearance. | https://en.wikipedia.org/wiki?curid=7731 |
Professor X
Professor Charles Francis Xavier (colloquial: Professor X) is a fictional character appearing in American comic books published by Marvel Comics. The character is depicted as the founder and sometimes leader of the X-Men. Created by writer Stan Lee and artist Jack Kirby, the character first appeared in "The X-Men" #1 (September 1963).
Xavier is a member of a subspecies of humans known as mutants, who are born with superhuman abilities. He is an exceptionally powerful telepath, who can read and control the minds of others. To both shelter and train mutants from around the world, he runs a private school in the X-Mansion in Salem Center, located in Westchester County, New York. Xavier also strives to serve a greater good by promoting peaceful coexistence and equality between humans and mutants in a world where zealous anti-mutant bigotry is widespread.
Throughout much of the character's history in comics, Xavier is a paraplegic variously using either a wheelchair or a modified version of one. One of the world's most powerful mutant telepaths, Xavier is a scientific genius and a leading authority in genetics. Furthermore, he has shown noteworthy talents in devising equipment to greatly enhance psionic powers. Xavier is perhaps best known in this regard for the creation of a device called Cerebro, a technology that serves to detect and track those individuals possessing the mutant gene, at the same time greatly expanding the gifts of those with existing psionic abilities.
From a social policy and philosophical perspective, Xavier deeply resents the violent methods of those like his former close friend and occasional enemy, the supervillain Magneto. Instead, he has presented his platform of uncompromising pacifism to see his dream to fruition – one that seeks to live harmoniously alongside humanity, just the same as it desires full-fledged civil rights and equality for all mutants. Xavier's actions and goals in life have therefore often been compared to those of Martin Luther King Jr. for his involvement with the American civil rights struggle, whereas Magneto is often compared with the more militant civil rights activist Malcolm X.
The character's creation and development occurred simultaneously with the civil rights struggle, taking place in the 1960s, while Xavier's first appearance dates to 1963. The fictionalized plight in the comics of mutantkind faced with exceptional intolerance and prejudice was done in large part to better illustrate to audiences of the day what was transpiring across the United States, just the same as it also served to further promote ideals of tolerance and equality for all.
Patrick Stewart portrayed the character in the first four films in the "X-Men" film series and in various video games, while James McAvoy portrayed a younger version of the character in the 2011 prequel "". Both actors reprised the role in the film "". McAvoy reprised the role in "", and Stewart in "Logan". McAvoy made a cameo in "Deadpool 2" and reprised his role in "Dark Phoenix". Harry Lloyd portrayed the character in the third season of the television series "Legion".
Created by writer Stan Lee and artist/co-writer Jack Kirby, Professor X first appeared in "X-Men" #1 (September 1963).
Stan Lee has stated that the physical inspiration of Professor Xavier was from Academy Award–winning actor Yul Brynner. Professor Xavier's character development has been inspired by Martin Luther King, Jr.
Writer Scott Lobdell established Xavier's middle name to be Francis in "Uncanny X-Men" #328 (January 1996).
Xavier's goals are to promote the peaceful affirmation of mutant rights, to mediate the co-existence of mutants and humans, to protect mutants from violent humans, and to protect society from antagonistic mutants, including his old friend, Magneto. To achieve these aims, he founded Xavier's School for Gifted Youngsters (later named the Xavier Institute) to teach mutants to explore and control their powers. Its first group of students was the original X-Men (Cyclops, Iceman, Marvel Girl, Angel, and Beast). Xavier's students consider him a visionary and often refer to their mission as "Xavier's dream". He is highly regarded by others in the Marvel Universe, respected by various governments, and trusted by several other superhero teams, including the Avengers and the Fantastic Four. However, he also has a manipulative streak which has resulted in several significant fallings-out with allies and students.
He often acts as a public advocate for mutant rights and is the authority most of the Marvel superhero community turns to for advice on mutants. Despite this, his status as a mutant himself and originator of the X-Men only became public during the 2001 story "E Is for Extinction". He also appears in almost all of the X-Men animated series and in many video games, although usually as a non-playable character because of his disability. Patrick Stewart plays him in the 2000s film series, as well as providing his voice in some of the X-Men video games (including some not connected to the film series).
According to "BusinessWeek", Charles Xavier is listed as one of the top ten most intelligent fictional characters in American comics.
In a number of comics, Xavier is shown to have a dark side, a part of himself that he struggles to suppress. Perhaps the most notable appearance of this character element is in the Onslaught storyline, in which the crossover event's antagonist is a physical manifestation of that dark side. Also, Onslaught is created in the most violent act Xavier claims to have done: erasing the mind of Magneto. In "X-Men" #106 (August 1977), the new X-Men fight images of the original team, which have been created by what Xavier says is his "evil self ... who would use his powers for personal gain and conquest", which he says he is normally able to keep in check. In the 1984 four-part series titled "The X-Men and the Micronauts", Xavier's dark desires manifest themselves as the Entity and threaten to destroy the Micronauts' universe.
In other instances, Xavier is shown to be secretive and manipulative. During the Onslaught storyline, the X-Men find Xavier's files, the "Xavier Protocols", which detail how to kill many of the characters, including Xavier himself, should the need ever arise, such as if they went rogue. "Astonishing X-Men" vol. 3, #12 (August 2005) reveals that when Xavier realizes that the Danger Room has become sentient, he keeps it trapped and experiments on it for years, an act that Cyclops calls "the oppression of a new life" and equates to humanity's treatment of mutants (however, "X-Men Legacy" #220 - 224 reveals that Xavier did not intend for the Danger Room to become sentient: it was an accident, and Xavier sought a way to free Danger, but was unable to find a way to accomplish this without deleting her sentience as well).
Charles Francis Xavier was born in New York City to the wealthy Dr. Brian Xavier, a well-respected nuclear scientist, and Sharon Xavier. The family lives in a very grand mansion estate in Westchester County because of the riches his father's nuclear research has brought them. He later grows up to attend the University of Oxford, where he earns a Professorship in Genetics and other science fields, and goes on to live in first Oxford and then London for a number of years. Crucially, as he enters late adolescence, Xavier inherits the mansion-house he was raised in, enabling him not only to continue to live in it, but also to turn it in to Xavier's School for Gifted Youngsters, which he begins together with the first of the X-Men.
Brian, his father, dies in an accident when Xavier is still very young, and Brian's science partner Kurt Marko comforts and then marries the grieving Sharon. When Xavier's telepathic mutant powers emerge, he discovers Marko cares only about his mother's money.
After the wedding, Kurt moves in with the Xaviers, bringing with him his son Cain. Kurt quickly grows neglectful of Sharon, driving her to alcoholism, and abuses both Charles and Cain. Cain takes out his frustrations and insecurities on his stepbrother. Charles uses his telepathic powers to read Cain's mind and explore the extent of his psychological damage, which only leads to Cain becoming more aggressive toward him and the young Xavier feeling Cain's pain firsthand.
Sharon dies soon after, and a fight erupts between Cain and Charles that causes some of Kurt's lab equipment to explode. Mortally wounded, Kurt drags the two children out before dying, and admits he was partly responsible for Brian's death.
With help from his superhuman powers and natural genius, Xavier becomes an excellent student and athlete, though he gives up the latter, believing his powers give him an unfair advantage. Due to his powers, by the time he graduates from high school, Charles loses all of his hair. He graduates with honors at the age of 16 from Bard College. In graduate studies, he receives Ph.D.s in Genetics, Biophysics, Psychology, and Anthropology with a two-year residence at Pembroke College, University of Oxford. He also receives an M.D. in Psychiatry while spending several years in London. He is later appointed Adjunct Professor at Columbia University. "Origins of Marvel Comics: X-Men" #1 (2010) presents a different version of events, suggesting a scholarship to the University of Oxford rescued him from his abusive home, after which he "never looked back", suggesting he began his academic career as a very young man at Oxford. His stepbrother is resentful of him.
At graduate school, he meets a Scottish girl named Moira Kinross, a fellow genetics student with whom he falls in love. The two agree to get married, but soon, Xavier is drafted into the Korean War. He carves himself a niche as a soldier in search and rescue missions alongside Shadowcat's father, Carmen Pryde, and witnesses Cain's transformation into Juggernaut when he touches a ruby with an inscription on it in an underground temple. During the war, he receives a letter from Moira telling him that she is breaking up with him. He later discovers that Moira married her old boyfriend Joseph MacTaggert, who abuses her.
Deeply depressed when Moira broke off their engagement without explanation, Xavier began traveling around the world as an adventurer after leaving the army. In Cairo, he meets a young girl named Ororo Munroe (later known as Storm), who is a pickpocket, and the Shadow King, a powerful mutant who is posing as Egyptian crime lord Amahl Farouk. Xavier defeats the Shadow King, barely escaping with his life. This encounter leads to Xavier's decision to devote his life to protecting humanity from evil mutants and safeguarding innocent mutants from human oppression.
Xavier visits his friend Daniel Shomron, who runs a clinic for traumatized Holocaust victims in Haifa, Israel. There, he meets a man going by the name of Magnus (who would later become Magneto), a Holocaust survivor who works as a volunteer in the clinic, and Gabrielle Haller, a woman driven into a catatonic coma by the trauma she experienced. Xavier uses his mental powers to break her out of her catatonia and the two fall in love. Xavier and Magneto become good friends, although neither immediately reveals to the other that he is a mutant. The two hold lengthy debates hypothesizing what will happen if humanity is faced with a new super-powered race of humans. While Xavier is optimistic, Magneto's experiences in the Holocaust lead him to believe that humanity will ultimately oppress the new race of humans as they have done with other minorities. The two friends reveal their powers to each other when they fight Nazi Baron Wolfgang von Strucker and his Hydra agents, who kidnap Gabrielle because she knows the location of their secret cache of gold. Magneto attempts to kill Strucker but Xavier stops him. Realizing that his and Xavier's views on mutant-human relations are incompatible, Magneto leaves with the gold. Charles stays in Israel for some time, but he and Gabrielle separate on good terms, neither knowing that she is pregnant with his son, who grows up to become the mutant Legion.
In a strange town near the Himalayas, Xavier encounters an alien calling himself Lucifer, the advance scout for an invasion by his race, and foils his plans. In retaliation, Lucifer drops a huge stone block on Xavier, crippling his legs. After Lucifer leaves, a young woman named Sage hears Xavier's telepathic cries for help and rescues him, bringing him to safety, beginning a long alliance between the two.
In a hospital in India, he is brought to an American nurse, Amelia Voght, who looks after him and, as she sees to his recovery, they fall in love. When he is released from the hospital, the two moved into an apartment in Bombay together. Amelia is troubled to find Charles studying mutation, as she is a mutant and unsettled by it, though she calms when he reveals himself to be a mutant as well. They eventually move to the United States, living on Xavier's family estate. But the night Scott Summers moves into Xavier's mansion, Amelia leaves him, believing Charles would have changed his view and that mutants should lie low. Yet he is recruiting them to what she believes is a lost cause. Charles tries to force her to stay with his mental powers, but immediately ashamed by this, lets her go. She later becomes a disciple of Magneto.
Over the years, Charles makes a name for himself as geneticist and psychologist, apparently renowned enough that the Greys were referred to him when no other expert could help their catatonic daughter, Jean. Xavier trains her in the use of her telekinesis, while inhibiting her telepathic abilities until she matures. Around this time, he also starts working with fellow mutation expert, Karl Lykos, as well as Moira MacTaggert again, who built a mutant research station on Muir Island. Apparently, Charles had gotten over Moira in his travels to the Greek island of Kirinos. Xavier discusses his candidates for recruitment to his personal strike force, the X-Men, with Moira, including those he passes over, which are Kurt Wagner, Piotr Rasputin, Pietro and Wanda Maximoff, and Ororo Munroe. Xavier also trains Tessa in order to spy on Sebastian Shaw.
Xavier founded Xavier's School for Gifted Youngsters, which provides a safe haven for mutants and teaches them to master their abilities. In addition, he seeks to foster mutant-human relations by providing his superhero team, the X-Men, as an example of mutants acting in good faith, as he told FBI agent Fred Duncan. With his inherited fortune, he uses his ancestral mansion at 1407 Graymalkin Lane in Salem Center, Westchester County, New York as a base of operations with technologically advanced facilities, including the Danger Room - later, Fantomex mentions that Xavier is a billionaire with a net worth of $3.5 billion. Presenting the image of a stern teacher, Xavier makes his students endure a rigorous training regime.
Xavier's first five students are Marvel Girl, Cyclops, Beast, Iceman, and Angel, who become the original X-Men. After he completes recruiting the original team of X-Men, he sends them into battle with Magneto.
Throughout most of his time with the team, Xavier uses his telepathic powers to keep in constant contact with his students and provides instructions and advice when needed. In addition, he uses a special machine called Cerebro, which enhances his ability to detect mutants and to allow the team to find new students in need of the school.
Among the obstacles Xavier faces is his old friend, Magneto, who has grown into an advocate of mutant superiority since their last encounter and who believes the only solution to mutant persecution is domination over humanity.
When anthropologist Bolivar Trask resurfaces the "mutant problem", Xavier counters him in a televised debate, however, he appears arrogant and Trask sends his mutant-hunting robot Sentinels to terrorize mutants. The X-Men dispatch them, but Trask sees the error in his ways too late as he is killed by his creations.
At one point, Xavier seemingly dies during the X-Men's battle with the sub-human Grotesk, but it is later revealed that Xavier arranged for a reformed former villain named Changeling to impersonate him while he went into hiding to plan a defense against an invasion by the extraterrestrial Z'Nox, imparting a portion of his telepathic abilities to the Changeling to complete the disguise.
When the X-Men are captured by the sentient island Krakoa, Xavier assembles a new team to rescue them, including Cyclops' and Havok's long-lost brother, Vulcan, along with Darwin, Petra, and Sway. This new team, composed of students of Dr. Moira MacTaggert, was sent to rescue the original X-Men from Krakoa. However, after rescuing Cyclops, McTaggert's former students were seemingly killed. Upon Cyclops' return, Xavier removed Cyclops' memories of the death of Vulcan and his teammates; and began assembling yet another team of X-Men.
Xavier's subsequent rescue team consists of Banshee, Colossus, Sunfire, Nightcrawler, Storm, Wolverine, and Thunderbird. After the mission, the older team of X-Men, except for Cyclops, leave the school, believing they no longer belong there, and Xavier mentors the new X-Men.
Xavier forms a psychic bond across galaxies with Princess Lilandra from the Shi'ar Empire. When they finally meet, it is love at first sight. She implores the professor to stop her mad brother, Shi'ar Emperor D'Ken, and he instantly aids her by deploying his X-Men. When Jean Grey returns from the Savage Land to tell him that all the X-Men are dead, he shuts down the school and travels with Lilandra to her kingdom, where she is crowned Empress and he is treated like a child or a trophy husband.
Xavier senses the changes taking place in Jean Grey, and returns to Earth to help and resume leadership of the X-Men. Shortly thereafter he battles his pupil after she becomes Dark Phoenix and destroys a populated planet in the Shi'ar Empire. It hurts Xavier to be on the opposite side of Lilandra, but he has no other choice but to challenge the Shi'ar Imperial Guard to a duel over the fate of the Phoenix. Xavier would have lost against the greater power of the Dark Phoenix, but thanks to the help Jean Grey gives him (fighting her Phoenix persona), Xavier emerges victorious; she later commits suicide in order to prevent herself from endangering more innocent lives.
When the X-Men fight members of the extraterrestrial race known as the Brood, Xavier is captured by them, and implanted with a Brood egg, which places Xavier under the Brood's control. During this time, Xavier assembles a team of younger mutants called the New Mutants, secretly intended to be prime hosts for reproduction of the aliens. The X-Men discover this and return to free Xavier, but they are too late to prevent his body from being destroyed with a Brood Queen in its place; however, his soul remains intact. The X-Men and Starjammers subdue this monstrous creature containing Xavier's essence, but the only way to restore him is to clone a new body using tissue samples he donated to the Starjammers and transfer his consciousness into the clone body. This new body possesses functional legs, though the psychosomatic pain Xavier experienced after living so long as a paraplegic takes some time to subside. Subsequently, he even joins the X-Men in the field, but later decides not to continue this practice after realizing that his place is at the school, as the teacher of the New Mutants.
After taking a teaching position at Columbia University in "Uncanny X-Men" #192, Xavier is severely injured and left for dead as the victim of a hate crime. Callisto and her Morlocks, a group of underground-dwelling mutants, get him to safety. One of the Morlocks partially restores Xavier's health, but Callisto warns Xavier that he is not fully healed and that he must spend more time recuperating and restrain himself from exerting his full strength or powers, or his health might fail again. Xavier hides his injuries from the others and resumes his life.
Charles meets with former lover Gabrielle Haller on Muir Isle and discovers that they had a child. The boy, David, is autistic and suffers from multiple personality disorder and has vast psionic powers like his father. After helping him and his team to escape from David's mind, Xavier promises he will always be there for him.
A reformed Magneto is arrested and put on trial. Xavier attends the trial to defend his friend. Andrea and Andreas Strucker, the children of presumed dead Baron von Strucker, crash the courtroom to attack Magneto and Xavier. Xavier is seriously injured. Dying, he asks a shocked Magneto to look after the X-Men for him. Lilandra, who has a psychic bond with Xavier, feels that he is in great danger and heads to Earth. There, she and Corsair take Xavier with them so Shi'ar advanced technology can heal him.
Xavier leaves Magneto in charge of the school, but some of the X-Men are unwilling to forgive their former enemy. Cyclops loses a duel for the leadership of the X-Men against Storm, then leaves them and joins the other four original X-Men to form a new team called X-Factor.
In the meantime, Charles becomes stranded in space with the Starjammers, but he is reunited with his lover Lilandra and relishes his carefree lifestyle. He serves as a member of the Starjammers aboard the starship "Starjammer", mobile in the Shi'ar Galaxy. He becomes consort to the Princess-Majestrix Lilandra while in exile, and when she later resumes her throne he takes up residence with her in the Imperial palace on the Shi'ar homeworld. Xavier joins Lilandra in her cause to overthrow her sister Deathbird, taking on the powers of Phoenix temporarily wherein he is named Bald Phoenix by Corsair, but sees that he must return to help the X-Men.
Xavier eventually becomes imprisoned by the Skrulls during their attempted invasion of the Shi'ar Empire. Xavier breaks free from imprisonment by Warskrull Prime, and is reunited with the X-Men. A healthy Xavier returns from the Shi'ar Empire and is reunited with both the current and original X-Men teams, and resumes his leadership responsibilities of the united teams. In a battle with his old foe, the Shadow King, in the "Muir Island Saga", Xavier's spine is shattered, returning him to his former paraplegic state, while his son David is seemingly killed. In the following months, Xavier rebuilds the mansion, which previously was rebuilt with Shi'ar technology, and restructures the X-Men into two teams.
While holding a mutant rights speech, Xavier is nearly assassinated by Stryfe in the guise of Cable, being infected with a fatal techno-organic virus. For reasons of his own, the villain Apocalypse saves him. As a temporary side-effect, he gains full use of his legs and devotes his precious time to the youngest recruit on his team, Jubilee.
With all his students now highly trained adults, Professor Xavier renames his school the Xavier Institute For Higher Learning. Also, he assumes control of a private institution, the Massachusetts Academy, making it a new School for Gifted Youngsters. Another group of young mutants is trained here, Generation X, with Banshee and Emma Frost as headmaster and headmistress, respectively.
Professor X is for a time the unknowing host of the evil psionic entity Onslaught, the result of a previous battle with Magneto. In that battle, Magneto uses his powers to rip out the adamantium bonded to Wolverine's skeleton, and a furious Xavier wipes Magneto's mind, leaving him in a coma. From the psychic trauma of Xavier using his powers so violently and the mixing of Magneto's and Xavier's repressed anger, Onslaught is born. Onslaught wreaks havoc, destroying much of Manhattan, until many of Marvel's superheroes—including the Avengers, the Fantastic Four and the Hulk—destroy him. Xavier is left without his telepathy and, overcome with guilt, leaves the X-Men and is incarcerated for his actions. He later returns to the X-Men after "", in which he is shocked by the cruel act of being turned over to the mutant-hating Bastion, following a clash with the sentient Cerebro and a team of impostor X-Men.
Xavier questions his dream again and Magneto shortly thereafter is confronted by the X-Men. After the battle, the UN concedes Genosha to Magnus, and Wolverine is angered by Xavier stopping him from getting his revenge on Magneto. Charles and Logan are later trapped in a dimension with different laws of physics, wherein they have to coordinate their moves together and, in the process, gain a better understanding of the other's views.
Apocalypse kidnaps the fabled "Twelve" special mutants (Xavier included) whose combined energies would grant him omnipotence. After Apocalypse's defeat with the help of Skrull mutants, Xavier goes with the young Skrulls known as Cadre K to train them and free them from their oppressors, and eventually returns to aid in Legacy Virus research.
Mystique and her Brotherhood start a deadly assault on Muir Isle by releasing an altered form of the Legacy Virus, all in retaliation against the election campaign of Robert Kelly, a seeming mutant-hater. Mystique blows up Moira MacTaggert's laboratory complex, fatally wounding her. Charles goes to the astral plane to meet with her and retrieve information on the cure to the Legacy Virus, but after gathering the information does not want to leave her alone. If not for Jean and Cable talking him down and pulling him back, the professor would have died with his first love, who states she has no regrets.
As Beast cures the Legacy Virus, many infected Genoshan mutants recover overnight, providing Magneto, the current ruler of Genosha, with an army to start the third World War. He demands Earth's governments accept him as their leader, and abducts and crucifies Xavier in Magda Square for all to see. A loyal member of Magneto's Acolytes, Amelia Voght, can't stand to see her former lover punished in such a manner and sets him free. Jean Grey and rather untrained newcomers, as most of the team are elsewhere, distract Magneto and Wolverine guts him. Xavier is too late to intervene.
Xavier's evil twin Cassandra Nova, whom Xavier attempted to kill while they were both in their mother's womb, orders a group of rogue Sentinels to destroy the independent mutant nation of Genosha. Magneto, who is Genosha's leader, appears to die along with the vast majority of the nation's inhabitants. Nova then takes over Xavier's body. Posing as Xavier, she reveals his mutation to the world, something he needed to do but did not want to sully his reputation over, before going into space and crippling the Shi'ar Empire. The X-Men restore Xavier, but Lilandra, believing that too much disaster has come from the Shi'ar's involvement with the X-Men, annuls her marriage to Xavier. Lilandra previously had gone insane and tried to assassinate Charles on a trip to Mumbai. During this period, a mutant named Xorn joins the X-Men. Xorn uses his healing power to restore Xavier's use of his legs.
When the X-Men receive a distress call from a Scottish island, they are surprised to find Juggernaut with nowhere to go, as the island was destroyed by his further-mutated partner in crime, Black Tom Cassidy, who died. Xavier reaches out to his stepbrother and offers him a place in his mansion, with Cain reluctantly accepting. The Juggernaut redeems himself over the next few weeks and joins the X-Men. Xavier finds out that Cain's father preferred him to his own flesh and blood and that they both thought they deserved the abuse they incurred by Kurt; Cain believed this because his father loved someone else's child more than him, and Charles felt guilty about getting in the way. That it is why neither of them stopped Kurt Marko with their powers.
Now outed as a mutant, Xavier makes speeches to the public about mutant tolerance. He also founds the X-Corporation, or X-Corp (not to be confused with the X-Corps), with offices all over the world. The purpose of the X-Corp is to watch over mutant rights and help mutants in need. As a result of being out, the school no longer hides the fact that it is a school for mutants and it opens its doors for more mutant (and even human) students to come in. A student named Quentin Quire and members of his gang start a riot at the Xavier Institute during an open house at the school. As a result, Quire and two other students are killed. Uncertain about his dream's validity, Xavier announces that he will step down as headmaster and be succeeded by Jean Grey. Afterwards, Xorn reveals himself to be Magneto, having apparently not died in the Sentinel raid on Genosha. Magneto undoes the restoration of Xavier's ability to walk, kidnaps him, and destroys the X-Mansion (killing several of the students). Then Xorn/Magneto assaults New York, where Cyclops, Fantomex and a few students confront him. After the rest of the X-Men arrive, Xorn/Magneto kills Jean Grey with an electromagnetically induced stroke, and Wolverine decapitates him. With Jean dead, Xavier leaves the school to Cyclops and Emma Frost, to bury Xorn/Magneto in Genosha. In a retcon of Grant Morrison's storyline, there Xavier meets the "real" Magneto, who mysteriously survived Cassandra Nova's assault. The two resolve their differences and attempt to restore their friendship, leading a team of mutants, the Genoshan Excalibur, to rebuild and restore order to the destroyed island nation.
At the mansion, the Danger Room (the X-Men’s simulated reality training chamber) gains sentience, christens itself "Danger", assumes a humanoid form, and attacks the X-Men before leaving to kill Xavier. With Magneto's help, Xavier holds off Danger until the X-Men arrive. Danger flees, but not before revealing to Colossus that Xavier has known it to be sentient ever since he upgraded it. Colossus is especially offended by this because he had been held captive and experimented upon by Danger's ally, Ord of the Breakworld. Ashamed, Xavier tries to explain to them that by the time he realized what was happening, he could see no other course. The disgusted X-Men leave.
In a prelude to "House of M", Magneto's daughter Scarlet Witch suffers a mental breakdown and causes the death of several Avengers. Magneto brings her to Xavier and asks him to use his mental powers to help her. Although aided by Doctor Strange and the appearance of Cassandra Nova, Xavier is unsuccessful. Xavier orders a meeting of the X-Men and Avengers to decide Wanda's fate. Her brother Quicksilver, believing the heroes plan to kill her, speeds off to Genosha and convinces Wanda that she could right the wrongs she inflicted by using her powers to alter reality.
Quicksilver somehow forces a tearful Wanda to reveal to him her heart's desires of Magneto, the assembled New Avengers, and the X-Men, and then uses her powers to make them all real. Thanks to Magneto, though, this re-imagined world is a place where a much more numerous mutant-kind are the dominant species, humans a disenfranchised and oppressed 'silent majority', and Magneto himself rules supreme. In this reality, the only proof that Charles Xavier ever existed is a secret monument in Magneto's palace garden, with the engraved message "He died so Genosha could live".
After mutant Layla Miller restores the memories of some of the X-Men and Avengers, they head to Genosha where they discover that Magneto has erected a memorial garden for Xavier commemorating his death. Emma is horrified until Cloak fades into the grave and discovers there is no body inside. After a battle, Scarlet Witch again uses her powers to restore reality and, as a slight against her father, causes a large majority mutants to lose their powers, leaving the mutant race on the brink of extinction and causing the lost powers to become an energy mass, the Collective. With reality restored, Xavier is still missing and the X-Men are unable to detect him with Cerebro".
Xavier returns when Cyclops' and Havok's long-lost brother, Vulcan, is revived by the Collective energy released as a result of the "House of M" incident. Vulcan then attacks the X-Men. Xavier, now depowered but able to walk in the wake of "House of M", reveals that he had gathered and trained another team of X-Men (this one composed of students of Dr. Moira MacTaggert) sometime between the original team and the new X-Men team introduced in "Giant Size X-Men" #1. This team included Vulcan as a member. Like the "Giant Size" X-Men team, McTaggert's former students were sent to rescue the original X-Men from Krakoa, the living island. However, after rescuing Cyclops, McTaggert's former students were seemingly killed. Upon Cyclops' return, Xavier removed Cyclops' memories of the death of Vulcan and his teammates and began assembling the "Giant Size" X-Men. Vulcan skirmishes with the X-Men and eventually flees into space.
In spite of Cyclops' feelings, Xavier forms a new team including Havok and Darwin, the lone other survivors of Moira's students. Xavier seeks to confront Vulcan before he can enact his vengeance against the Shi'ar empire, which killed Vulcan's mother. While en route to the Shi'ar homeworld, Xavier is abducted and is later thrown into the M'Kraan Crystal by Vulcan. Darwin follows Xavier into the crystal and pulls Xavier out. This somehow restores Xavier's lost telepathy. With help from his longtime lover, Lilandra, Xavier escapes back to Earth with several of his X-Men.
Upon Xavier's return to Earth, as seen in the "World War Hulk" storyline, he begins to search for lost mutants such as Magneto. Charles' search for more mutants is interrupted by the Hulk, who was sent into extraterrestrial exile by the Illuminati, a group of powerful superbeings to which Xavier belongs. Xavier had no part in (and did not know of) the Hulk exile decision, but Xavier admits to Hulk that he would have concurred to a temporary exile so Bruce Banner could be cured of transforming into the Hulk. However, he also tells the Hulk he would not have agreed to permanent exile. Xavier attempts to surrender to the Hulk, but after viewing the X-Mansion's large graveyard dedicated to post-M-Day mutant deaths, The Hulk concludes the mutants have suffered enough and leaves the Mansion grounds on his own accord. While the X-Men tend to the wounded, Cyclops finally forgives Professor X.
While using Cerebra and talking to Beast during the "" storyline, Charles detects a new mutant so powerful it fries Cerebra's system. He asks Cyclops to send out a team to find out about the mutant. Once the team has come back empty handed, he argues with Scott for not telling him about the team he deployed to find former Acolytes. Scott tells him outright that he doesn't need him to run the X-Men anymore. This upsets Charles and annoys him later on when he overhears Cyclops briefing X-Factor on the situation. He also approaches the New X-Men in an attempt to help them figure out a non-violent way to help against the Purifiers, but is quickly rebuked by Surge, who questions where he was when they were getting attacked the first time, and that they didn't need to learn from him. Charles questions Cyclops' decision to send X-Force to hunt down his own son, Cable, in front of the students. Cyclops then tells Xavier that he is a distraction that will keep getting in the way and that he must leave the mansion. Xavier is contacted by Cable, who lost the mutant newborn to the traitorous actions of Bishop, who in turn lost the child to the Marauders, and tells him that he is the only one who can help Cable save the future. In the final fight, Xavier is accidentally shot in the head by Bishop. Immediately afterward Xavier's body disappears and Cyclops declares that there are no more X-Men.
Professor Xavier survives Bishop's gunshot but falls into a coma. Xavier is kidnapped by Exodus, Tempo, and Karima Shapandar. Exodus tries to heal Xavier, Xavier mentally fights Exodus. Exodus finally approaches Magneto, who is apparently still depowered, for help. Magneto and Karima Shapandar are able to stir Xavier's memories and coax him out of his coma, though Xavier remains slightly confused and partly amnesiac. Later, Exodus confronts Magneto about Joanna Cargill's injury (Magneto was forced to shoot a laser through her eyeball in order to prevent her attempted an assassination of Xavier). Exodus nearly kills Magneto, and Xavier drags Exodus onto the Astral Plane, putting Xavier's own newly restored mind at stake. Xavier defeats Exodus after a harrowing psionic battle, and Exodus reveals the reason he abducted Xavier and to restore his mind: Exodus wants Xavier to lead the Acolytes and find the mutant messiah child (now under the guardianship of Cable) in order to indoctrinate the child into their cause. Xavier refuses. Emma Frost's telepathy picks up on the psychic fight, and Emma informs Cyclops that Xavier is alive. Xavier parts company with Magneto and Karima to try to regain his lost memories by visiting people from his past.
The first person Charles visits is Carter Ryking, who had gone insane after losing his powers. Charles reads Carter's memories and discovers that when the two were children they were used as test subjects by Nathan Milbury of the Black Womb Project, with the approval of Charles' father, Doctor Brian Xavier. Xavier makes the connection Milbury and X-Men villain, Mister Sinister, who has apparently long been manipulating Charles' life in addition to other X-Men. Afterwards, he discovers he has been targeted by assassins.
Charles eventually discovers Mister Sinister had set up Charles, Sebastian Shaw, Juggernaut, and Ryking (Hazard) as potential new hosts for Sinister's mind. Bleeding slowly to death, he apparently gives in to Sinister becoming the new Mister Sinister. But in reality, Xavier is still battling Sinister for control of his body. As Sebastian Shaw and Gambit destroy Sinister's Cronus Machine, the device that he used to transfer his consciousness into new hosts, Xavier drives Sinister out of his body permanently. Xavier thanks Shaw and Gambit for their help and declares he must go and see Cyclops immediately. Professor X returns to the X-Mansion to find it destroyed after recent events. Afterwards, Xavier leaves the ruins of the X-Mansion to secretly meet up Cyclops by psychically coercing his former student for the visit. Xavier explains to Cyclops about the recent events with Mr. Sinister and tries to explain to Cyclops how Sinister has been manipulating Scott's and Jean's lives since when they were children. Xavier attempts to have Scott give him permission to scan Scott's mind for traces of Sinister's influences, but instead, Scott turns the tables on Xavier by revealing that he has secretly invited Emma Frost into their entire meeting and also into Xavier's mind.
While in his mind, Emma forces Xavier to relive each of his morally ambiguous decisions under altruistic pretenses. As the issue continues, Charles realizes his human arrogance and that while some of his decisions were morally wrong, he must move forward with his life and deal with the consequences. Emma ends her incursion into Xavier's mind by reminding him of Moira MacTaggert's last words. As he reflects on Moira's words, Xavier gives Cyclops his blessing to lead the X-Men and leaves to find his own path. Following his encounter with Wolverine (in the "Original Sin" Arc) Professor Xavier seeks out his step-brother, the unstoppable Juggernaut in an attempt to reform him. After a conversation about the meaning of the word "Juggernaut" and a review of Juggernaut and Xavier's shared history Xavier offers Cain an empty box as a gift. Confused by Xavier's gift Cain attempts to kill the Professor bringing an entire sports bar down over their heads in the process. Later Cain battles the X-Men in his full Juggernaut armor and conquers the planet. Just as everything appears to be under the Juggernaut's control Xavier reappears and informs him that everything that has just taken place except for Juggernaut destroying the bar took place in Cain's mind. A baffled Cain demands to know how Xavier managed to overcome his psychically shielded helmet to which the Professor replies that he decided to visit Cain in his sleep. Professor Xavier then informs him that he now understands Cain as a person and that he will not attempt to get in his way or reform him again. But Xavier also warns Cain that if he gets in the way of the Professor's path to redemption Xavier will stop him permanently. Following his encounter with Cain it has been revealed that Xavier is now searching for Rogue.
After his bruising encounter with Cyclops and Emma Frost, Professor X is forced to revisit the biggest challenge and the biggest failure of his career, Wolverine, when the feral mutant asks for Charles' help in freeing his son from the clutches of the Hellfire Club. As the two search for Daken, Wolverine reveals that when he first joined the X-Men he attempted to assassinate Xavier due to some unknown programming. In response, the Professor broke Logan's mind and rebuilt it so that any and all programming he received was forgotten. Logan also revealed that the real reason Xavier asked him to join the X-Men was that Charles "needed a weapon". Eventually Professor Xavier and Wolverine locate Sebastian Shaw's mansion and attack his minions, just as they are about to enter a bomb explodes from within catching them both off guard. From the wreckage emerges an angry Sebastian who immobilizes Wolverine. Meanwhile, Miss Sinister knocks Daken unconscious and has him taken to the med lab in the mansion's basement. As Shaw prepares to deliver a killing blow to Xavier, Wolverine recovers and stops him telling Xavier to rescue his son. Professor Xavier locates the med lab and after a quick psychic battle with Miss Sinister enters Daken's fractured mind. While in Daken's mind Xavier discovers Romulus's psychic tampering and comments that Daken's mind is even more broken than Wolverine's was. Before Xavier can heal Daken a psychic bomb explodes causing Xavier to become comatose and Daken to wake up. Miss Sinister arrives and attempts to manipulate Daken who reveals that the psychic bomb in his head restored his memories and stabs Miss Sinister in the chest. Meanwhile, Wolverine defeats Shaw and enters the mansion to find Daken standing over an unconscious Xavier preparing to kill him. Wolverine tells Daken that he won't let him hurt Xavier and the two fight. Overcome with guilt over what happened to Daken and Itsu, Wolverine allows himself to be beaten. Just as Daken appears to have won Xavier pulls both of them onto the astral plane revealing that the psychic bomb had little effect on him because his psyche was already shattered. Xavier then explains to Wolverine and Daken that Romulus is solely responsible for Itsu's death and that he lied to Daken about everything because he wanted Wolverine to become his weapon. As the three converse, Daken returns to the physical plane and prevents Shaw from killing Xavier. With the truth revealed Wolverine and Daken decide to kill Romulus. As the two depart Wolverine tells Xavier that he forgives him for all of the dark moments in their history. Wolverine acknowledges that Professor Xavier allowed him to become a hero. Wolverine then tells the Professor that he hopes he will one day be able to forgive him for choosing to kill Romulus.
Professor Xavier recruits Gambit to go with him to Australia to find and help Rogue who is currently staying at the X-Men's old base in the Outback; unaware Danger is using Rogue as a conduit for her revenge against him.
In a prelude to the "Secret Invasion" storyline, Professor X was at the meeting of the Illuminati when it came to the discussion about the Skrulls planning an invasion by taking out Earth's heroes and posing as them. He claims he was unable to distinguish that Black Bolt had been replaced by a Skrull, and his powers were tested quickly by the Black Bolt Skrull. Professor X leaves after learning even he can no longer trust the others, yet appears to have severely restricted the number of people he informs of the forthcoming alien invasion, as the X-Men were not prepared for the Skrulls, at least at first. Xavier has not seen again during the events of "Secret Invasion", though his X-Men in San Francisco are successful at repelling the invaders there through the use of the modified Legacy Virus.
During the "Dark Reign" storyline, Professor X convinces Exodus to disband the Acolytes. A H.A.M.M.E.R. helicopter arrives and from inside appears Norman Osborn, who wants to talk to him. During the Dark Avengers' arrival in San Francisco to enforce martial law and squelch the anti-mutant riots occurring in the city, Xavier appears (back in his wheelchair) in the company of Norman Osborn and publicly denounces Cyclops' actions and urges him to turn himself in. However, this Xavier was revealed to be Mystique who Osborn recruited to impersonate Xavier in public. The real Xavier is shown in prison on Alcatraz and slowly being stripped of his telepathic powers while in psionic contact with Beast, who was arrested earlier for his part in the anti-mutant riots. It was also revealed by Emma Frost that she and Professor X are both Omega Class Telepaths when she manages to detect the real Professor X. Professor X helps Emma Frost enter Sentry's mind. However, as Emma frees him of the Void's influence, a minute sliver of the entity itself remains in her mind. Xavier quickly tells her to remain in her diamond armor state to prevent the Void from gaining access to her psi-powers. Professor X is later seen with Emma Frost where Beast is recuperating.
After the events of "Utopia", Xavier has come to live on the risen Asteroid M, rechristened Utopia, along with the rest of the X-Men, X-Club, and mutant refugees and is also allowed to join the Utopia lead council (Cyclops, Storm, Namor, Iceman, Beast, Wolverine and Emma Frost). While he no longer continues to openly question every move that Cyclops makes, he is still concerned about some of his leadership decisions. Xavier had wanted to return to the mainland in order to clear his name, but in the aftermath of Osborn declaring Utopia as a mutant detention area, Cyclops refused to let him leave, stating that it would be a tactical advantage to have him as an ace in the hole in case the need arose. To that end, he has kept Xavier out of the field and instead relied on Emma Frost, Psylocke and the Stepford Cuckoos respectively for their own psionic talents. While attending the funeral of Yuriko Takiguchi, Magneto arrives at Utopia, apparently under peaceful motives. Xavier does not believe it, and attacks Magneto telepathically, causing Cyclops to force him to stand down. He later apologizes to Magneto for acting out of his old passions from their complicated relationship, which Magneto accepts.
During the "" storyline, Professor Xavier is seen on Utopia delivering a eulogy at Nightcrawler's funeral. Like the other X-Men, he is deeply saddened by Kurt's death and anxious about the arrival of Cable and Hope. Xavier is seen using his powers to help his son Legion control his many personalities and battle the Nimrods. At the conclusion of Second Coming Professor X is seen surveying the aftermath of the battle from a helicopter. As Hope descends to the ground and cradles Cable's lifeless arm, Xavier reflects on everything that has transpired and states that, while he feels that Hope has indeed come to save mutant kind and revive his dream, she is still only a young woman and will have a long and difficult journey before she can truly achieve her potential.
During the "Avengers vs. X-Men" storyline, the Phoenix Force is split into five pieces and bonded with Cyclops, Emma Frost, Namor, Colossus and Magik (who become known as the Phoenix Five). Eventually, Cyclops and Frost come to possess the full Phoenix Force, and Professor X is instrumental in confronting them both, and dies in the ensuing battle with Cyclops. The Phoenix Force is subsequently forced to abandon Cyclops as a host by the efforts of both Hope Summers and the Scarlet Witch.
Xavier's body is later stolen by the Red Skull's S-Men while the group also captures Rogue and Scarlet Witch. Xavier's brain is removed and fused to the brain of the Red Skull. After Rogue and Scarlet Witch snapped out of the fight they were in, they find the lobotomized body of Professor X. Red Skull uses the new powers conferred upon him by Professor X's brain to provoke anti-mutant riots. His plans are foiled by the Avengers and the X-Men, and the Skull escapes.
Professor X's spirit is later seen in the Heaven dimension along with Nightcrawler's spirit at the time when Azazel invades Heaven.
During the "AXIS" storyline, a fragment of Professor X's psyche (which had escaped the scrubbing of his memories) still existed in Red Skull's mind preventing him from unleashing the full potential of Professor X's powers. During a fight with the Stark Sentinels, Doctor Strange and Scarlet Witch attempt to cast a spell to invert the axis of Red Skull's brain and bring out the fragment of Professor X to defeat Onslaught. Doctor Strange was targeted and captured by the Sentinels before they could cast the spell. When Magneto arrived with his supervillain allies, Doctor Doom and Scarlet Witch attempted to cast the inversion spell again and Red Onslaught was knocked unconscious and reverted to his Red Skull form. Although they did not know whether Professor X was now in control, the Avengers decided to be cautious and take Red Skull to Stark Tower. It was later revealed that the spell had actually caused all the heroes and villains present to undergo a "moral inversion" rather than simply bringing out Professor X in the Skull, with the result that the Skull and other villains became heroic while the Avengers and X-Men present became villainous. Eventually, the inversion was undone.
After the Skull mounts a telepathic assault that nearly allows him to take control of the Avengers, he is defeated when Deadpool places Magneto's old helmet on Rogue, allowing her to knock out the Skull and take him to Beast. Beast is subsequently able to perform brain surgery on the Skull, extracting the part of Xavier's brain that was grafted onto the villain's own brain without causing any apparent damage to the Skull. Rogers attempts to claim the fragment for himself, but Rogue flies up and incinerates the fragment with the aid of the Human Torch, the two expressing hope that Xavier will rest in peace.
The astral form of Professor Xavier has since been revealed to be imprisoned in the Astral Plane after Shadow King somehow acquired it upon Professor X's death. After what appeared to be years in the Astral Plane, Professor X is able to trick Shadow King into playing him in a 'game' that lures Rogue, Mystique and Fantomex onto the Astral Plane, while turning others into carriers for the Shadow King's 'contagious' psychic essence. With the Shadow King certain of his victory, he fails to realize that Xavier's apparent 'surrender' to his game was really just him biding his time until the Shadow King's influence was distracted long enough for him to drop his already-subtly-weakened guard long enough for Xavier to break his bonds, luring in the three aforementioned X-Men as their identities were already fundamentally malleable. With the Shadow King defeated, Xavier is apparently returned to the real world in the body of Fantomex, Fantomex reasoning that nobody really knows who he is as an individual beyond his status as one of the X-Men whereas this act of sacrifice will ensure that he is remembered for a great deed.
Proteus has spent years trapped in a psionic hellscape of the Astral Plane, where The Shadow King reigned supreme, only to escape last issue. Part of the reason that he could was the escape of Charles Xavier (who now chooses to go by X, since he is now in a younger body after escaping), and now X leads the X-Men directly into an ambush, as Proteus has warped an entire village with his powers, leading to a mind-to-mind battle that leaves X on the receiving end of a psychic beatdown.
Proteus has started his garden and his seeds are planted all over the world. Psylocke is in command and has a plan which mainly consists of Archangel using metal and Mystique morphing into his mother. Once they drain him, Rogue and Bishop convert his energy and release him back to the universe. Whilst this all went down Psylocke and X combined forces to burn out the seeds across the planet. As they are working on it they discover they are not enough to accomplish the task. X mentions the network of psychics the Shadow King was using and that Betsy who is in control should tap into it. She agrees and does so yet unbeknownst to her X was possessed by the Shadow King who violently erupts from X's head.
Following X’s apparent death after the Shadow King exploded from his skull, the psychic villain tears the X-Men apart until X literally pulls himself back together (a feat he later refuses to explain), and he and Psylocke team up to harness the power of all of Earth’s psychics to destroy the Shadow King. As Psylocke says she feels no psychic trace of him anywhere, X implants comforting post-hypnotic psychic suggestions in his allies and then erases their memories (including allowing Warren Worthington to switch between his identities at will). Only Psylocke’s memory is left intact, with X telling her she’ll be the one to “keep him honest” while he embarks on a new mission.
X has since made his presence known to his former students and reveals his new plan for all mutantkind. Now clad in a Cerebro-like helmet, Xavier has apparently abandoned his dream for peaceful coexistence, and had turned Krakoa into a sovereign nation state for mutants as well as use it to apparently heal the X-Men from their ordeals during the showdown against the forces of O.N.E. He then leads the X-Men into planting in seeds in strategic locations around the world and Mars, which, overnight, grow into massive plantlike "Habitats". As it turns out, these "Habitats" – and the plants that grew them – are extensions of Krakoa. Through the advancement of mutant technology combined with Krakoa's unique abilities as a living mutant island, Professor X and the X-Men have embassies around the world. Also through this combination of technology and mutant power, Xavier have developed three drugs that could change human life – a pill that extends human life by five years, an adaptable universal antibiotic, and a pill that cures "diseases of the mind, in humans".” In exchange for recognizing the sovereignty of Krakoa, Professor X will give these drugs to mankind, with mutants living in peace on the island.
Xavier and Magneto later meet with Raven Darkholm inside his sanctum. The two mutant leaders both greatly pleased with the success of her mission as she presents what they'ed petitioned her to steal. A mysterious USB tab containing sensitive information stolen from Damage Control, Mystique would inquire for her payment as she'd met their demands. However, Xavier mentions that he still had more demands that needed to met as they were building their protected future of Homo Sapiens Superior, seeming to psychokinetically beckon the contents of her theft into his hands while Mystique questions how much more needed to be done for his ultimate pet project.
Xavier and Magneto reveal the contents of the USB drive to Cyclops, which are shown to be information on Orchis, an organization dedicated to responding to a large-scale mutant threat and the plans of a Mother Mold. They believe that the creation of the Mother Mold will herald a new generation of Sentinels and along with it, Nimrod. They task Cyclops with assembling a team to destroy the Mother Mold station. Although the team (composed of Cyclops, Marvel Girl, Wolverine, Nightcrawler, Husk, Mystique, Archangel, and Monet) is successfully, they are all killed in the process. X mourns them, vowing "No more."
Xavier is revealed to have upgraded Cerebro with the help of Forge, which is now able to copy and store the minds of mutants in a database. After the Five (Hope Summers, Goldballs, Elixir, Proteus, and Tempus) are able to grow the bodies of deceased mutants, Xavier is able to copy the minds back in these empty shells. Thus, he is able to resurrect Cyclops's team, thanking them for what they did. At the U.N., Xavier, Beast, and Emma celebrate with other ambassadors for the recognition of Krakoa as a sovereign nation. Xavier telepathically converses with Emma, revealing that he knows that she manipulated the Russian ambassador to abstain from the vote, before thanking her for her service. Two days after the U.N. vote, Xavier, Magneto, and Wolverine are in Krakoa waiting besides several portals. While Wolverine expresses his misgivings about the upcoming event, Xavier and Magneto assure him all will be alright. Soon after, several villainous mutants, including Mister Sinister, Sebastian Shaw, Exodus, Selene (comics) and Apocalypse arrive through the portals. Apocalypse in particular expresses satisfaction at arriving and Krakoa responds in the same way. Magneto and Xavier reveal that they have invited all mutants, even those who have fought against them in the past, to Krakoa, to form a society. The assembled villainous mutants agree to their terms, and Xavier shakes Apocalypse's hand, welcoming him and the others to their home."
While peace reigns on Krakoa, a mysterious team of assassins HALO drops into the island and assasinates Xavier.
Professor X is a mutant who possesses vast telepathic powers, and is among the strongest and most powerful telepaths in the Marvel Universe. He is able to perceive the thoughts of others or project his own thoughts within a radius of approximately . Xavier's telepathy once covered the entire world; although following this, Magneto altered the Earth's electromagnetic field to restrict Xavier's telepathic range. While not on Earth, Xavier's natural telepathic abilities have reached across space to make universal mental contact with multiple alien races. With extreme effort, he can also greatly extend the range of his telepathy. He can learn foreign languages by reading the language centers of the brain of someone adept, and alternately "teach" languages to others in the same manner. Xavier once trained a new group of mutants mentally, subjectively making them experience months of training together, while only hours passed in the real world.
Xavier's vast psionic powers enable him to manipulate the minds of others, warp perceptions to make himself seem invisible, project mental illusions, cause loss of particular memories or total amnesia, and induce pain or temporary mental and/or physical paralysis in others. Within close range, he can manipulate almost any number of minds for such simple feats. However, he can only take full possession of one other mind at a time, and must strictly be within that person's physical presence. He is one of the few telepaths skilled enough to communicate with animals and even share their perceptions. He can also telepathically take away or control people's natural bodily functions and senses, such as sight, hearing, smell, taste, or even mutant powers. A side effect of his telepathy is that he has an eidetic memory and his brain can assimilate and process impossibly huge amounts of raw data in an astonishingly short amount of time. He has displayed telepathic prowess sufficient to confront Ego the Living Planet (while aided by Cadre K) as well as narrowly defeat Exodus. However, he cannot permanently "reprogram" human minds to believe what he might want them to believe even if he wanted to do so, explaining that the mind is an organism that would always recall the steps necessary for it to reach the present and thus 'rewrite' itself to its original setting if he tried to change it. However, his initial reprogramming of Wolverine lasted several years, despite Wolverine overcoming the reprogramming much faster than an ordinary human because of his healing factor.
He is able to project from his mind 'bolts' composed of psychic energy, enabling him to stun the mind of another person into unconsciousness, inflict mental trauma, or even cause death. These 'bolts' inflict damage only upon other minds, having a negligible effect on non-mental beings, if any. The manner in which Xavier's powers function indicates that his telepathy is physical in some way, as it can be enhanced by physical means (for example, Cerebro), but can also be disrupted by physical means (for example, Magneto's alteration of the Earth's magnetic field).
Xavier can perceive the distinct mental presence/brain waves of other superhuman mutants within a small radius of himself. To detect mutants to a wider area beyond this radius, he must amplify his powers through Cerebro and subsequently Cerebra, computer devices of his own design which are sensitive to the psychic/physical energies produced by the mind.
Professor X can project his astral form into a psychic dimension known as the astral plane. There, he can use his powers to create objects, control his surroundings, and even control and destroy the astral forms of others. He cannot project this form over long distances.
"Uncanny X-Men" writer Ed Brubaker has claimed that, after being de-powered by the Scarlet Witch, and then re-powered by the M'Kraan Crystal, Charles' telepathy is more powerful than was previously known. However, the extent of this enhancement is unknown. Years prior to initial publishing, Charles Xavier had an ill defined level of Telekinesis. This aspect of his powers were potent enough to cause catastrophic system disruption in computerized appliances. Such an attribute would eventually fade over time, contrary to their dissipation however. His evil counterpart Cassandra Nova Xavier would come into such abilities in her own right, indicating he still possessed the potential for said abilities. An indication later proven true after his death and resurgence within the younger, stronger body of Charlie Cluster 7. Where the Professor, now going by the moniker of X, took to fashioning a Cerebro like helmet for himself which acts as a focusing device for his psionic powers. Having used it to galvanize latent aspects of his X-Gene in order to stimulate some dormant properties, seemingly using telekinesis to will a flash drive on Mystique's person into his hand.
Charles Xavier is a genius with multiple doctorates. He is a world-renowned geneticist, a leading expert in mutation, possesses considerable knowledge of various life sciences, and is the inventor of Cerebro. He possesses Ph.D.s in Genetics, Biophysics, Psychology, and Anthropology, and an M.D. in Psychiatry. He is highly talented in devising equipment for utilizing and enhancing psionic powers. He is also a great tactician and strategist, effectively evaluating situations and devising swift responses.
During his travels in Asia, Xavier learned martial arts, acquiring "refined combat skills" according to Magneto. When these skills are coordinated in tandem with his telepathic abilities, Xavier is a dangerous unarmed combatant, capable of sensing the intentions of others and countering them with superhuman efficiency. He also has extensive knowledge of pressure points.
Charles Xavier was also given possession of the Mind Infinity Gem. It allows the user to boost mental power and access the thoughts and dreams of other beings. Backed by the Power Gem, it is possible to access all minds in existence simultaneously. Like all other former Illuminati members, Xavier has sworn to never use the gem and to keep its location hidden.
The Xavier Protocols are a set of doomsday plans created by Professor X. The protocols detail the best way to kill many powerful mutant characters, including the X-Men and Xavier himself, should they become too large of a danger. The Xavier Protocols are first mentioned during the "Onslaught" crossover and first seen in "Excalibur" #100 in Moira MacTaggert's lab. Charles Xavier compiled a list of the Earth's most powerful mutants and plans on how to defeat them if they become a threat to the world. They are first used after Onslaught grows too powerful. Only parts of the actual protocols are ever shown. In the "" crossover Bastion obtains an encrypted copy of the protocols, intending to use them against the X-Men. However, Cable infiltrates the X-Mansion and secures all encrypted files before Bastion has a chance to decrypt them. Due to the tampering of Bastion and his Sentinels, the X-Mansion computer system Cerebro gains autonomy and seeks to destroy the X-Men by employing its knowledge of the Xavier Protocols. In a virtual environment created by Professor X, Cerebro executes the Xavier Protocols against the X-Men.
Each protocol is activated by the presence of a different combination of X-Men and were written by Xavier himself:
Other X-Men who have faced their Xavier Protocols are Colossus, Rogue, Shadowcat, Nightcrawler, Storm, and Gambit.
Professor X has appeared on a number of animated television shows including the "X-Men" animated series voiced by Cedric Smith, "" voiced by David Kaye, and in "Wolverine and the X-Men" voiced by Jim Ward.
He has appeared in eleven live-action "X-Men" feature films to date. He is played by Patrick Stewart in "X-Men", "X2", "", "", "The Wolverine", and "Logan" and by James McAvoy in "", "", "Deadpool 2" and "Dark Phoenix". Both actors play him at different time-periods in "".
Harry Lloyd portrays a young Charles Xavier in the television series "Legion".
He has also appeared in a number of books and video games. | https://en.wikipedia.org/wiki?curid=7732 |
Central Pacific Railroad
The Central Pacific Railroad (CPRR) was a rail company chartered by U.S. Congress in 1862 to build a railroad eastwards from Sacramento, California, to complete the western part of the "First Transcontinental Railroad" in North America. Incorporated in 1861, CPRR ceased operation in 1885 when it was acquired by Southern Pacific Railroad as a leased line.
Following the completion of the Pacific Railroad Surveys in 1855, several national proposals to build a transcontinental railroad failed because of the energy consumed by political disputes over slavery. With the secession of the South in 1861, the modernizers in the Republican Party controlled the US Congress. They passed legislation in 1862 authorizing the central rail route with financing in the form of land grants and government railroad bond, which were all eventually repaid with interest. The government and the railroads both shared in the increased value of the land grants, which the railroads developed. The construction of the railroad also secured for the government the economical "safe and speedy transportation of the mails, troops, munitions of war, and public stores."
Planned by Theodore Judah, the Central Pacific Railroad was authorized by Congress in 1862. It was incorporated in 1861 by Judah and "The Big Four" (who called themselves "The Associates"): Sacramento, California businessmen Leland Stanford, Collis Huntington, Charles Crocker, and Mark Hopkins. Stanford was elected president (at the same time he was elected governor), Huntington vice-president in charge of fund raising and purchasing, and Hopkins treasurer. Crocker was in charge of construction, which began officially in 1863 when the first rails were laid in Sacramento. Construction proceeded in earnest in 1865 when James Harvey Strobridge, the head of the construction work force, hired the first Cantonese emigrant workers at Crocker's suggestion. The construction crew grew to include 12,000 Chinese laborers by 1868, when they constituted eighty percent of the entire work force. The "Golden spike", connecting the western railroad to the Union Pacific Railroad at Promontory, Utah, was hammered on May 10, 1869. Coast-to-coast train travel in eight days became possible, replacing months-long sea voyages and lengthy, hazardous travel by wagon trains.
In 1885 the Central Pacific Railroad was acquired by the Southern Pacific Company as a leased line. Technically the CPRR remained a corporate entity until 1959, when it was formally merged into Southern Pacific. (It was reorganized in 1899 as the Central Pacific "Railway".) The original right-of-way is now controlled by the Union Pacific, which bought Southern Pacific in 1996.
The Union Pacific-Central Pacific (Southern Pacific) main line followed the historic Overland Route from Omaha, Nebraska to San Francisco Bay.
Chinese labor was the most vital source for constructing the railroad. Fifty Cantonese emigrant workers were hired by the Central Pacific Railroad in February 1865 on a trial basis, and soon more and more Cantonese emigrants were hired. Working conditions were harsh, and Chinese were compensated less than their white counterparts. Chinese laborers were paid thirty-one dollars each month, and while white workers were paid the same, they were also given room and board.
Construction of the road was financed primarily by 30-year, 6% U.S. government bonds authorized by Sec. 5 of the Pacific Railroad Act of 1862. They were issued at the rate of $16,000 ($265,000 in 2017 dollars) per mile of tracked grade completed west of the designated base of the Sierra Nevada range near Roseville, CA where California state geologist Josiah Whitney had determined were the geologic start of the Sierras' foothills. Sec. 11 of the Act also provided that the issuance of bonds "shall be treble the number per mile" (to $48,000) for tracked grade completed over and within the two mountain ranges (but limited to a total of at this rate), and "doubled" (to $32,000) per mile of completed grade laid between the two mountain ranges. The U.S. Government Bonds, which constituted a lien upon the railroads and all their fixtures, were repaid in full (and with interest) by the company as and when they became due.
Sec. 10 of the 1864 amending Pacific Railroad Act (13 Statutes at Large, 356) additionally authorized the company to issue its own "First Mortgage Bonds" in total amounts up to (but not exceeding) that of the bonds issued by the United States. Such company-issued securities had priority over the original Government Bonds. (Local and state governments also aided the financing, although the City and County of San Francisco did not do so willingly. This materially slowed early construction efforts.) Sec. 3 of the 1862 Act granted the railroads of public land for every mile laid, except where railroads ran through cities and crossed rivers. This grant was apportioned in 5 sections on alternating sides of the railroad, with each section measuring by . These grants were later doubled to per mile of grade by the 1864 Act.
Although the Pacific Railroad eventually benefited the Bay Area, the City and County of San Francisco obstructed financing it during the early years of 1863–1865. When Stanford was Governor of California, the Legislature passed on April 22, 1863, "An Act to Authorize the Board of Supervisors of the City and County of San Francisco to take and subscribe One Million Dollars to the Capital Stock of the Western Pacific Rail Road Company and the Central Pacific Rail Road Company of California and to provide for the payment of the same and other matters relating thereto" (which was later amended by Section Five of the "Compromise Act" of April 4, 1864). On May 19, 1863, the electors of the City and County of San Francisco passed this bond by a vote of 6,329 to 3,116, in a highly controversial Special Election.
The City and County's financing of the investment through the issuance and delivery of Bonds was delayed for two years, when Mayor Henry P. Coon, and the County Clerk, Wilhelm Loewy, each refused to countersign the Bonds. It took legal actions to force them to do so: in 1864 the Supreme Court of the State of California ordered them under Writs of Mandamus ("The People of the State of California "ex rel" the Central Pacific Railroad Company vs. Henry P. Coon, Mayor; Henry M. Hale, Auditor; and Joseph S. Paxson, Treasurer, of the City and County of San Francisco." 25 Cal. 635) and in 1865, a legal judgment against Loewy ("The People "ex rel" The Central Pacific Railroad Company of California vs. The Board of Supervisors of the City and County of San Francisco, and Wilhelm Lowey, Clerk" 27 Cal. 655) directing that the Bonds be countersigned and delivered.
In 1863 the State legislature's forcing of City and County action became known as the "Dutch Flat Swindle". Critics claimed the CPRR's Big Four intended to build a railroad only as far as Dutch Flat, California, to connect to the Dutch Flat-Donner Pass Wagon Road to monopolize the lucrative mining traffic, and not push the track east of Dutch Flat into the more challenging and expensive High Sierra effort. CPRR's chief engineer, Theodore Judah, also argued against such a road and hence against the Big Four, fearing that its construction would siphon money from CPRR's paramount trans-Sierra railroad effort. Despite Judah's strong objection, the Big Four incorporated in August 1863 the Dutch Flat-Donner Lake Wagon Road Company. Frustrated, Judah headed off for New York via Panama to raise funds to buy out the Big Four from CPRR and build his trans-Sierra railroad. Unfortunately, Judah contracted yellow fever in Panama and died in New York in November 1863.
A replica of the Sacramento, California Central Pacific Railroad passenger station is part of the California State Railroad Museum, located in the Old Sacramento State Historic Park.
Nearly all the company's early correspondence is preserved at Syracuse University, as part of the Collis Huntington Papers collection. It has been released on microfilm (133 reels). The following libraries have the microfilm: University of Arizona at Tucson; and Virginia Commonwealth University at Richmond. Additional collections of manuscript letters are held at Stanford University and the Mariners' Museum at Newport News, Virginia. Alfred A. Hart was the official photographer of the CPRR construction.
The Central Pacific's first three locomotives were of the then common 4-4-0 type, although with the American Civil War raging in the east, they had difficulty acquiring engines from eastern builders, who at times only had smaller 4-2-4 or 4-2-2 types available. Until the completion of the Transcontinental rail link and the railroad's opening of its own shops, all locomotives had to be purchased by builders in the northeastern U.S. The engines had to be dismantled, loaded on a ship, which would embark on a four-month journey that went around South America's Cape Horn until arriving in Sacramento where the locomotives would be unloaded, re-assembled, and placed in service.
Locomotives at the time came from many manufacturers, such as Cooke, Schenectady, Mason, Rogers, Danforth, Norris, Booth, and McKay & Aldus, among others. The railroad had been on rather unfriendly terms with the Baldwin Locomotive Works, one of the more well-known firms. It is not clear as to the cause of this dispute, though some attribute it to the builder insisting on cash payment (though this has yet to be verified). Consequently, the railroad refused to buy engines from Baldwin, and three former Western Pacific Railroad (which the CP had absorbed in 1870) engines were the only Baldwin engines owned by the Central Pacific. The Central Pacific's dispute with Baldwin remained unresolved until well after the road had been acquired by the Southern Pacific.
In the 1870s, the road opened up its own locomotive construction facilities in Sacramento. Central Pacific's 173 was rebuilt by these shops and served as the basis for CP's engine construction. The locomotives built before the 1870s were given names as well as numbers. By the 1870s, it was decided to eliminate the names and as each engine was sent to the shops for service, their names would be removed. However, one engine that was built in the 1880s did receive a name: the El Gobernador.
Construction of the rails was often dangerous work. Towards the end of construction, almost all workers were Chinese immigrants. The ethnicity of workers depended largely on the "gang" of workers/specific area on the rails they were working.
The following CP engines have been preserved:
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1876
1877
1883
1885
1888
1899
1959 | https://en.wikipedia.org/wiki?curid=7734 |
Chiropractic
Chiropractic is a pseudoscientific gastrointestinal disorders, kinetic imbalance due to suboccipital strain (KISS) in infants, menstrual cramps, insomnia, postmenopausal symptoms, or pelvic and back pain during pregnancy. As there is no evidence of effectiveness or safety for cervical manipulation for baby colic, it is not endorsed.
The World Health Organization found chiropractic care in general is safe when employed skillfully and appropriately. There is not sufficient data to establish the safety of chiropractic manipulations. Manipulation is regarded as relatively safe but complications can arise, and it has known adverse effects, risks and contraindications. Absolute contraindications to spinal manipulative therapy are conditions that should not be manipulated; these contraindications include rheumatoid arthritis and conditions known to result in unstable joints. Relative contraindications are conditions where increased risk is acceptable in some situations and where low-force and soft-tissue techniques are treatments of choice; these contraindications include osteoporosis. Although most contraindications apply only to manipulation of the affected region, some neurological signs indicate referral to emergency medical services; these include sudden and severe headache or neck pain unlike that previously experienced. Indirect risks of chiropractic involve delayed or missed diagnoses through consulting a chiropractor.
Spinal manipulation is associated with frequent, mild and temporary adverse effects, including new or worsening pain or stiffness in the affected region. They have been estimated to occur in 33% to 61% of patients, and frequently occur within an hour of treatment and disappear within 24 to 48 hours; adverse reactions appear to be more common following manipulation than mobilization. The most frequently stated adverse effects are mild headache, soreness, and briefly elevated pain fatigue. Chiropractic is correlated with a very high incidence of minor adverse effects. Chiropractic are more commonly associated with serious related adverse effects than other professionals following manipulation. Rarely, spinal manipulation, particularly on the upper spine, can also result in complications that can lead to permanent disability or death; these can occur in adults and children. There is a case of a three-month-old dying following manipulation of the neck area. Estimates vary widely for the incidence of these complications, and the actual incidence is unknown, due to high levels of underreporting and to the difficulty of linking manipulation to adverse effects such as stroke, which is a particular concern. Adverse effects are poorly reported in recent studies investigating chiropractic manipulations. A 2016 systematic review concludes that the level of reporting is unsuitable and unacceptable. Reports of serious adverse events have occurred, resulting from spinal manipulation therapy of the lumbopelvic region. Estimates for serious adverse events vary from 5 strokes per 100,000 manipulations to 1.46 serious adverse events per 10 million manipulations and 2.68 deaths per 10 million manipulations, though it was determined that there was inadequate data to be conclusive. Several case reports show temporal associations between interventions and potentially serious complications. The published medical literature contains reports of 26 deaths since 1934 following chiropractic manipulations and many more seem to remain unpublished.
Vertebrobasilar artery stroke (VAS) is statistically associated with chiropractic services in persons under 45 years of age, but it is similarly associated with general practitioner services, suggesting that these associations are likely explained by preexisting conditions. Weak to moderately strong evidence supports causation (as opposed to statistical association) between cervical manipulative therapy (CMT) and VAS. There is insufficient evidence to support a strong association or no association between cervical manipulation and stroke. While the biomechanical evidence is not sufficient to support the statement that CMT causes cervical artery dissection (CD), clinical reports suggest that mechanical forces have a part in a substantial number of CDs and the majority of population controlled studies found an association between CMT and VAS in young people. It is strongly recommended that practitioners consider the plausibility of CD as a symptom, and people can be informed of the association between CD and CMT before administrating manipulation of the cervical spine. There is controversy regarding the degree of risk of stroke from cervical manipulation. Many chiropractors state that, the association between chiropractic therapy and vertebral arterial dissection is not proven. However, it has been suggested that the causality between chiropractic cervical manipulation beyond the normal range of motion and vascular accidents is probable or definite. There is very low evidence supporting a small association between internal carotid artery dissection and chiropractic neck manipulation. The incidence of internal carotid artery dissection following cervical spine manipulation is unknown. The literature infrequently reports helpful data to better understand the association between cervical manipulative therapy, cervical artery dissection and stroke. The limited evidence is inconclusive that chiropractic spinal manipulation therapy is not a cause of intracranial hypotension. Cervical intradural disc herniation is very rare following spinal manipulation therapy.
Chiropractors, like other primary care providers, sometimes employ diagnostic imaging techniques such as X-rays and CT scans that rely on ionizing radiation. Although there is no clear evidence for the practice, some chiropractors may still X-ray a patient several times a year. Practice guidelines aim to reduce unnecessary radiation exposure, which increases cancer risk in proportion to the amount of radiation received. Research suggests that radiology instruction given at chiropractic schools worldwide seem to be evidence-based. Although, there seems to be a disparity between some schools and available evidence regarding the aspect of radiography for patients with acute low back pain without an indication of a serious disease, which may contribute to chiropractic overuse of radiography for low back pain.
A 2012 systematic review concluded that no accurate assessment of risk-benefit exists for cervical manipulation. A 2010 systematic review stated that there is no good evidence to assume that neck manipulation is an effective treatment for any medical condition and suggested a precautionary principle in healthcare for chiropractic intervention even if a causality with vertebral artery dissection after neck manipulation were merely a remote possibility. The same review concluded that the risk of death from manipulations to the neck outweighs the benefits. Chiropractors have criticized this conclusion, claiming that the author did not evaluate the potential benefits of spinal manipulation. Edzard Ernst stated "This detail was not the subject of my review. I do, however, refer to such evaluations and should add that a report recently commissioned by the General Chiropractic Council did not support many of the outlandish claims made by many chiropractors across the world."
A 2009 review evaluating maintenance chiropractic care found that spinal manipulation is associated with considerable harm and no compelling evidence exists to indicate that it adequately prevents symptoms or diseases, thus the risk-benefit is not evidently favorable.
A 2012 systematic review suggested that the use of spine manipulation in clinical practice is a cost-effective treatment when used alone or in combination with other treatment approaches. A 2011 systematic review found evidence supporting the cost-effectiveness of using spinal manipulation for the treatment of sub-acute or chronic low back pain; the results for acute low back pain were insufficient.
A 2006 systematic cost-effectiveness review found that the reported cost-effectiveness of spinal manipulation in the United Kingdom compared favorably with other treatments for back pain, but that reports were based on data from clinical trials without sham controls and that the specific cost-effectiveness of the treatment (as opposed to non-specific effects) remains uncertain. A 2005 American systematic review of economic evaluations of conservative treatments for low back pain found that significant quality problems in available studies meant that definite conclusions could not be drawn about the most cost-effective intervention. The cost-effectiveness of maintenance chiropractic care is unknown.
Analysis of a clinical and cost utilization data from the years 2003 to 2005 by an integrative medicine independent physician association (IPA) which looked the chiropractic services utilization found that the clinical and cost utilization of chiropractic services based on 70,274 member-months over a 7-year period decreased patient costs associate with the following use of services by 60% for in-hospital admissions, 59% for hospital days, 62% for outpatient surgeries and procedures, and 85% for pharmaceutical costs when compared with conventional medicine (visit to a medical doctor primary care provider) IPA performance for the same health maintenance organization product in the same geography and time frame.
Requirements vary between countries. In the U.S. chiropractors obtain a non-medical accredited diploma in the field of chiropractic. Chiropractic education in the U.S. has been criticized for failing to meet generally accepted standards of evidence-based medicine. The curriculum content of North American chiropractic and medical colleges with regard to basic and clinical sciences has little similarity, both in the kinds of subjects offered and in the time assigned to each subject. Accredited chiropractic programs in the U.S. require that applicants have 90 semester hours of undergraduate education with a grade point average of at least 3.0 on a 4.0 scale. Many programs require at least three years of undergraduate education, and more are requiring a bachelor's degree. Canada requires a minimum three years of undergraduate education for applicants, and at least 4200 instructional hours (or the equivalent) of full‐time chiropractic education for matriculation through an accredited chiropractic program. Graduates of the Canadian Memorial Chiropractic College (CMCC) are formally recognized to have at least 7–8 years of university level education. The World Health Organization (WHO) guidelines suggest three major full-time educational paths culminating in either a DC, DCM, BSc, or MSc degree. Besides the full-time paths, they also suggest a conversion program for people with other health care education and limited training programs for regions where no legislation governs chiropractic.
Upon graduation, there may be a requirement to pass national, state, or provincial board examinations before being licensed to practice in a particular jurisdiction. Depending on the location, continuing education may be required to renew these licenses. Specialty training is available through part-time postgraduate education programs such as chiropractic orthopedics and sports chiropractic, and through full-time residency programs such as radiology or orthopedics.
In the U.S., chiropractic schools are accredited through the Council on Chiropractic Education (CCE) while the General Chiropractic Council (GCC) is the statutory governmental body responsible for the regulation of chiropractic in the UK. The U.S. CCE requires a mixing curriculum, which means a straight-educated chiropractor may not be eligible for licensing in states requiring CCE accreditation. CCEs in the U.S., Canada, Australia and Europe have joined to form CCE-International (CCE-I) as a model of accreditation standards with the goal of having credentials portable internationally. Today, there are 18 accredited Doctor of Chiropractic programs in the U.S., 2 in Canada, 6 in Australasia, and 5 in Europe. All but one of the chiropractic colleges in the U.S. are privately funded, but in several other countries they are in government-sponsored universities and colleges. Of the two chiropractic colleges in Canada, one is publicly funded (UQTR) and one is privately funded (CMCC). In 2005, CMCC was granted the privilege of offering a professional health care degree under the Post-secondary Education Choice and Excellence Act, which sets the program within the hierarchy of education in Canada as comparable to that of other primary contact health care professions such as medicine, dentistry and optometry.
Regulatory colleges and chiropractic boards in the U.S., Canada, Mexico, and Australia are responsible for protecting the public, standards of practice, disciplinary issues, quality assurance and maintenance of competency. There are an estimated 49,000 chiropractors in the U.S. (2008), 6,500 in Canada (2010), 2,500 in Australia (2000), and 1,500 in the UK (2000).
Chiropractors often argue that this education is as good as or better than medical physicians', but most chiropractic training is confined to classrooms with much time spent learning theory, adjustment, and marketing. The fourth year of chiropractic education persistently showed the highest stress levels. Every student, irrespective of year, experienced different ranges of stress when studying. The chiropractic leaders and colleges have had internal struggles. Rather than cooperation, there has been infighting between different factions. A number of actions were posturing due to the confidential nature of the chiropractic colleges in an attempt to enroll students.
The chiropractic oath is a modern variation of the classical Hippocratic Oath historically taken by physicians and other healthcare professionals swearing to practice their professions ethically. The American Chiropractic Association (ACA) has an ethical code "based upon the acknowledgement that the social contract dictates the profession's responsibilities to the patient, the public, and the profession; and upholds the fundamental principle that the paramount purpose of the chiropractic doctor's professional services shall be to benefit the patient." The International Chiropractor's Association (ICA) also has a set of professional canons.
A 2008 commentary proposed that the chiropractic profession actively regulate itself to combat abuse, fraud, and quackery, which are more prevalent in chiropractic than in other health care professions, violating the social contract between patients and physicians. According to a 2015 Gallup poll of U.S. adults, the perception of chiropractors is generally favorable; two-thirds of American adults agree that chiropractors have their patient's best interest in mind and more than half also agree that most chiropractors are trustworthy. Less than 10% of US adults disagreed with the statement that chiropractors were trustworthy.
Chiropractors, especially in America, have a reputation for unnecessarily treating patients. In many circumstances the focus seems to be put on economics instead of health care. Sustained chiropractic care is promoted as a preventive tool, but unnecessary manipulation could possibly present a risk to patients. Some chiropractors are concerned by the routine unjustified claims chiropractors have made. A 2010 analysis of chiropractic websites found the majority of chiropractors and their associations made claims of effectiveness not supported by scientific evidence, while 28% of chiropractor websites advocate lower back pain care, which has some sound evidence.
The US Office of the Inspector General (OIG) estimates that for calendar year 2013, 82% of payments to chiropractors under Medicare part B, a total of $359 million, did not comply with Medicare requirements. There have been at least 15 OIG reports about chiropractic billing irregularities since 1986.
In 2009, a backlash to the libel suit filed by the British Chiropractic Association (BCA) against Simon Singh inspired the filing of formal complaints of false advertising against more than 500 individual chiropractors within one 24-hour period, prompting the McTimoney Chiropractic Association to write to its members advising them to remove leaflets that make claims about whiplash and colic from their practice, to be wary of new patients and telephone inquiries, and telling their members: "If you have a website, take it down NOW" and "Finally, we strongly suggest you do NOT discuss this with others, especially patients." An editorial in "Nature" suggested that the BCA may have been trying to suppress debate and that this use of English libel law was a burden on the right to freedom of expression, which is protected by the European Convention on Human Rights. The libel case ended with the BCA withdrawing its suit in 2010.
Chiropractic is established in the U.S., Canada, and Australia, and is present to a lesser extent in many other countries. It is viewed as a marginal and non-clinically–proven attempt at complementary and alternative medicine, which has not integrated into mainstream medicine. Billions are spent annually for chiropractic services.
In Australia, there are approximately 2488 chiropractors, or one chiropractor for every 7980 people. Most private health insurance funds in Australia cover chiropractic care, and the federal government funds chiropractic care when the patient is referred by a medical practitioner. In 2014, the chiropractic profession had a registered workforce of 4,684 practitioners in Australia represented by two major organizations — the Chiropractors’ Association of Australia (CAA) and the Chiropractic and Osteopathic College of Australasia (COCA). Annual expenditure on chiropractic care (alone or combined with osteopathy) in Australia is estimated to be between AUD$750–988 million with musculoskeletal complaints such as back and neck pain making up the bulk of consultations; and proportional expenditure is similar to that found in other countries. While Medicare (the Australian publicly funded universal health care scheme) coverage of chiropractic services is limited to only those directed by a medical referral to assist chronic disease management, most private health insurers in Australia do provide partial reimbursement for a wider range of chiropractic services in addition to limited third party payments for workers compensation and motor vehicle accidents.
Of the 2,005 chiropractors who participated in a 2015 survey, 62.4% were male and the average age was 42.1 (SD = 12.1) years. Nearly all chiropractors (97.1%) had a bachelor's degree or higher, with the majority of chiropractor's highest professional qualification being a bachelor or double bachelor's degree (34.6%), followed by a master's degree (32.7%), Doctor of Chiropractic (28.9%) or PhD (0.9%). Only a small number of chiropractor's highest professional qualification was a diploma (2.1%) or advanced diploma (0.8%).
In the United Kingdom, there are over 2,000 chiropractors, representing one chiropractor per 29,206 people. Chiropractic is available on the National Health Service in some areas, such as Cornwall, where the treatment is only available for neck or back pain.
A 2010 study by questionnaire presented to UK chiropractors indicated only 45% of chiropractors disclosed with patients the serious risk associated with manipulation of the cervical spine and that 46% believed there was possibility patients would refuse treatment if the risks were correctly explained. However 80% acknowledged the ethical/moral responsibility to disclose risk to patients.
The percentage of the population that utilizes chiropractic care at any given time generally falls into a range from 6% to 12% in the U.S. and Canada, with a global high of 20% in Alberta in 2006. In 2008, chiropractors were reported to be the most common CAM providers for children and adolescents, these patients representing up to 14% of all visits to chiropractors.
There were around 50,330 chiropractors practicing in North America in 2000. In 2008, this has increased by almost 20% to around 60,000 chiropractors. In 2002–03, the majority of those who sought chiropractic did so for relief from back and neck pain and other neuromusculoskeletal complaints; most do so specifically for low back pain. The majority of U.S. chiropractors participate in some form of managed care. Although the majority of U.S. chiropractors view themselves as specialists in neuromusculoskeletal conditions, many also consider chiropractic as a type of primary care. In the majority of cases, the care that chiropractors and physicians provide divides the market, however for some, their care is complementary.
In the U.S., chiropractors perform over 90% of all manipulative treatments. Satisfaction rates are typically higher for chiropractic care compared to medical care, with a 1998 U.S. survey reporting 83% of respondents satisfied or very satisfied with their care; quality of communication seems to be a consistent predictor of patient satisfaction with chiropractors.
Utilization of chiropractic care is sensitive to the costs incurred by the co-payment by the patient. The use of chiropractic declined from 9.9% of U.S. adults in 1997 to 7.4% in 2002; this was the largest relative decrease among CAM professions, which overall had a stable use rate. As of 2007 7% of the U.S. population is being reached by chiropractic. They were the third largest medical profession in the US in 2002, following physicians and dentists. Employment of U.S. chiropractors was expected to increase 14% between 2006 and 2016, faster than the average for all occupations.
In the U.S., most states require insurers to cover chiropractic care, and most HMOs cover these services.
Chiropractic was founded in 1895 by Daniel David (D.D.) Palmer in Davenport, Iowa. Palmer, a magnetic healer, hypothesized that manual manipulation of the spine could cure disease. The first chiropractic patient of D.D. Palmer was Harvey Lillard, a worker in the building where Palmer's office was located. He claimed that he had severely reduced hearing for 17 years, which started soon following a "pop" in his spine. A few days following his adjustment, Lillard claimed his hearing was almost completely restored. Chiropractic competed with its predecessor osteopathy, another medical system based on magnetic healing and bonesetting; both systems were founded by charismatic midwesterners in opposition to the conventional medicine of the day, and both postulated that manipulation improved health. Although initially keeping chiropractic a family secret, in 1898 Palmer began teaching it to a few students at his new Palmer School of Chiropractic. One student, his son Bartlett Joshua (B.J.) Palmer, became committed to promoting chiropractic, took over the Palmer School in 1906, and rapidly expanded its enrollment.
Early chiropractors believed that all disease was caused by interruptions in the flow of innate intelligence, a vitalistic nervous energy or life force that represented God's presence in man; chiropractic leaders often invoked religious imagery and moral traditions. D.D. Palmer said he "received chiropractic from the other world". D.D. and B.J. both seriously considered declaring chiropractic a religion, which might have provided legal protection under the U.S. constitution, but decided against it partly to avoid confusion with Christian Science. Early chiropractors also tapped into the Populist movement, emphasizing craft, hard work, competition, and advertisement, aligning themselves with the common man against intellectuals and trusts, among which they included the American Medical Association (AMA).
Chiropractic has seen considerable controversy and criticism. Although D.D. and B.J. were "straight" and disdained the use of instruments, some early chiropractors, whom B.J. scornfully called "mixers", advocated the use of instruments. In 1910, B.J. changed course and endorsed X-rays as necessary for diagnosis; this resulted in a significant exodus from the Palmer School of the more conservative faculty and students. The mixer camp grew until by 1924 B.J. estimated that only 3,000 of the U.S.'s 25,000 chiropractors remained straight. That year, B.J.'s invention and promotion of the neurocalometer, a temperature-sensing device, was highly controversial among B.J.'s fellow straights. By the 1930s, chiropractic was the largest alternative healing profession in the U.S.
Chiropractors faced heavy opposition from organized medicine. DD Palmer was jailed in 1907 for practicing medicine without a license. Thousands of chiropractors were prosecuted for practicing medicine without a license, and D.D. and many other chiropractors were jailed. To defend against medical statutes, B.J. argued that chiropractic was separate and distinct from medicine, asserting that chiropractors "analyzed" rather than "diagnosed", and "adjusted" subluxations rather than "treated" disease. B.J. cofounded the Universal Chiropractors' Association (UCA) to provide legal services to arrested chiropractors. Although the UCA won their first test case in Wisconsin in 1907, prosecutions instigated by state medical boards became increasingly common and in many cases were successful. In response, chiropractors conducted political campaigns to secure separate licensing statutes, eventually succeeding in all fifty states, from Kansas in 1913 through Louisiana in 1974. The longstanding feud between chiropractors and medical doctors continued for decades. The AMA labeled chiropractic an "unscientific cult" in 1966, and until 1980 advised its members that it was unethical for medical doctors to associate with "unscientific practitioners". This culminated in a landmark 1987 decision, "Wilk v. AMA", in which the court found that the AMA had engaged in unreasonable restraint of trade and conspiracy, and which ended the AMA's de facto boycott of chiropractic.
Serious research to test chiropractic theories did not begin until the 1970s, and is continuing to be hampered by antiscientific and pseudoscientific ideas that sustained the profession in its long battle with organized medicine. By the mid 1990s there was a growing scholarly interest in chiropractic, which helped efforts to improve service quality and establish clinical guidelines that recommended manual therapies for acute low back pain. In recent decades chiropractic gained legitimacy and greater acceptance by medical physicians and health plans, and enjoyed a strong political base and sustained demand for services. However, its future seemed uncertain: as the number of practitioners grew, evidence-based medicine insisted on treatments with demonstrated value, managed care restricted payment, and competition grew from massage therapists and other health professions. The profession responded by marketing natural products and devices more aggressively, and by reaching deeper into alternative medicine and primary care.
The word "chiropractic" comes from Greek χειρο- "chiro-" (itself from χείρ "cheir" "hand"), "hand" and πρακτικός "praktikos", "practical". Chiropractic is classified as a field of pseudomedicine on account of its esoteric origins.
Some chiropractors oppose vaccination and water fluoridation, which are common public health practices. Within the chiropractic community there are significant disagreements about vaccination, one of the most cost-effective public health interventions available. Most chiropractic writings on vaccination focus on its negative aspects, claiming that it is hazardous, ineffective, and unnecessary. Some chiropractors have embraced vaccination, but a significant portion of the profession rejects it, as original chiropractic philosophy traces diseases to causes in the spine and states that vaccines interfere with healing. The extent to which anti-vaccination views perpetuate the current chiropractic profession is uncertain. The American Chiropractic Association and the International Chiropractors Association support individual exemptions to compulsory vaccination laws, and a 1995 survey of U.S. chiropractors found that about a third believed there was no scientific proof that immunization prevents disease. The Canadian Chiropractic Association supports vaccination; a survey in Alberta in 2002 found that 25% of chiropractors advised patients for, and 27% against, vaccinating themselves or their children.
Early opposition to water fluoridation included chiropractors, some of whom continue to oppose it as being incompatible with chiropractic philosophy and an infringement of personal freedom. Other chiropractors have actively promoted fluoridation, and several chiropractic organizations have endorsed scientific principles of public health. In addition to traditional chiropractic opposition to water fluoridation and vaccination, chiropractors' attempts to establish a positive reputation for their public health role are also compromised by their reputation for recommending repetitive lifelong chiropractic treatment.
Throughout its history chiropractic has been the subject of internal and external controversy and criticism. According to Daniel D. Palmer, the founder of chiropractic, subluxation is the sole cause of disease and manipulation is the cure for all diseases of the human race. A 2003 profession-wide survey found "most chiropractors (whether 'straights' or 'mixers') still hold views of innate intelligence and of the cause and cure of disease (not just back pain) consistent with those of the Palmers." A critical evaluation stated "Chiropractic is rooted in mystical concepts. This led to an internal conflict within the chiropractic profession, which continues today." Chiropractors, including D.D. Palmer, were jailed for practicing medicine without a license. For most of its existence, chiropractic has battled with mainstream medicine, sustained by antiscientific and pseudoscientific ideas such as subluxation. Collectively, systematic reviews have not demonstrated that spinal manipulation, the main treatment method employed by chiropractors, is effective for any medical condition, with the possible exception of treatment for back pain. Chiropractic remains controversial, though to a lesser extent than in past years. | https://en.wikipedia.org/wiki?curid=7738 |
Carbide
In chemistry, a carbide usually describes a compound composed of carbon and a metal. In metallurgy, carbiding or carburizing is the process for producing carbide coatings on a metal piece.
The carbides of the group 4, 5 and 6 transition metals (with the exception of chromium) are often described as interstitial compounds. These carbides have metallic properties and are refractory. Some exhibit a range of stoichiometries, being a non-stoichiometric mixture of various carbides arising due to crystal defects. Some of them e.g. titanium carbide, TiC and tungsten carbide are important industrially and are used to coat metals in cutting tools.
The long-held view is that the carbon atoms fit into octahedral interstices in a close-packed metal lattice when the metal atom radius is greater than approximately 135 pm:
The following table shows actual structures of the metals and their carbides. (N.B. the body centered cubic structure adopted by vanadium, niobium, tantalum, chromium, molybdenum and tungsten is not a close-packed lattice.) The notation "h/2" refers to the M2C type structure described above, which is only an approximate description of the actual structures. The simple view that the lattice of the pure metal "absorbs" carbon atoms can be seen to be untrue as the packing of the metal atom lattice in the carbides is different from the packing in the pure metal, although it is technically correct that the carbon atoms fit into the octahedral interstices of a close-packed metal lattice.
For a long time the non-stoichiometric phases were believed to be disordered with a random filling of the interstices, however short and longer range ordering has been detected.
Iron forms a number of carbides, Fe3C, Fe7C3 and Fe2C. The best known is cementite, Fe3C, which is present in steels. These carbides are more reactive than the interstitial carbides; for example, the carbides of Cr, Mn, Fe, Co and Ni are all hydrolysed by dilute acids and sometimes by water, to give a mixture of hydrogen and hydrocarbons. These compounds share features with both the inert interstitials and the more reactive salt-like carbides.
Some metals, such as lead and tin, are believed not to form carbides under any circumstances. There exists however a mixed titanium-tin carbide, which is a two-dimensional conductor.
Carbides can be generally classified by the chemical bonds type as follows: (i) salt-like (ionic), (ii) covalent compounds, (iii) interstitial compounds, and (iv) "intermediate" transition metal carbides. Examples include calcium carbide (CaC2), silicon carbide (SiC), tungsten carbide (WC; often called, simply, "carbide" when referring to machine tooling), and cementite (Fe3C), each used in key industrial applications. The naming of ionic carbides is not systematic.
Salt-like carbides are composed of highly electropositive elements such as the alkali metals, alkaline earth metals, and group 3 metals, including scandium, yttrium, and lanthanum. Aluminium from group 13 forms carbides, but gallium, indium, and thallium do not. These materials feature isolated carbon centers, often described as "C4−", in the methanides or methides; two-atom units, "", in the acetylides; and three-atom units, "", in the allylides. The graphite intercalation compound KC8, prepared from vapour of potassium and graphite, and the alkali metal derivatives of C60 are not usually classified as carbides.
Methanides are a subset of carbides distinguished by their tendency to decompose in water producing methane. Three examples are aluminium carbide , magnesium carbide and beryllium carbide .
Transition metal carbides are not saline carbides but their reaction with water is very slow and is usually neglected. For example, depending on surface porosity, 5–30 atomic layers of titanium carbide are hydrolyzed, forming methane within 5 minutes at ambient conditions, following by saturation of the reaction.
Note that methanide in this context is a trivial historical name. According to the IUPAC systematic naming conventions, a compound such as NaCH3 would be termed a "methanide", although this compound is often called methylsodium.
Several carbides are assumed to be salts of the acetylide anion C22– (also called percarbide), which has a triple bond between the two carbon atoms. Alkali metals, alkaline earth metals, and lanthanoid metals form acetylides, e.g., sodium carbide Na2C2, calcium carbide CaC2, and LaC2. Lanthanides also form carbides (sesquicarbides, see below) with formula M2C3. Metals from group 11 also tend to form acetylides, such as copper(I) acetylide and silver acetylide. Carbides of the actinide elements, which have stoichiometry MC2 and M2C3, are also described as salt-like derivatives of .
The C-C triple bond length ranges from 119.2 pm in CaC2 (similar to ethyne), to 130.3 pm in LaC2 and 134 pm in UC2. The bonding in LaC2 has been described in terms of LaIII with the extra electron delocalised into the antibonding orbital on , explaining the metallic conduction.
The polyatomic ion , sometimes called allylide, is found in Li4C3 and Mg2C3. The ion is linear and is isoelectronic with CO2. The C-C distance in Mg2C3 is 133.2 pm. Mg2C3 yields methylacetylene, CH3CCH, and propadiene, CH2CCH2, on hydrolysis, which was the first indication that it contains .
The carbides of silicon and boron are described as "covalent carbides", although virtually all compounds of carbon exhibit some covalent character. Silicon carbide has two similar crystalline forms, which are both related to the diamond structure. Boron carbide, B4C, on the other hand, has an unusual structure which includes icosahedral boron units linked by carbon atoms. In this respect boron carbide is similar to the boron rich borides. Both silicon carbide (also known as "carborundum") and boron carbide are very hard materials and refractory. Both materials are important industrially. Boron also forms other covalent carbides, e.g. B25C.
Metal complexes containing C are known as metal carbido complexes. Most common are carbon-centered octahedral clusters, such as [Au6C(PPh3)6]2+ and [Fe6C(CO)6]2−. Similar species are known for the metal carbonyls and the early metal halides. A few terminal carbides have been isolated, e.g., [CRuCl2{P(C6H11)3}2].
Metallocarbohedrynes (or "met-cars") are stable clusters with the general formula where M is a transition metal (Ti, Zr, V, etc.).
In addition to the carbides, other groups of related carbon compounds exist: | https://en.wikipedia.org/wiki?curid=7739 |
Charles C. Krulak
Charles Chandler Krulak (born March 4, 1942) is a retired United States Marine Corps officer who served as the 31st Commandant of the Marine Corps from July 1, 1995 to June 30, 1999. He is the son of Lieutenant General Victor H. "Brute" Krulak, who served in World War II, Korea, and Vietnam. He was the 13th President of Birmingham-Southern College after his stint as a non-executive director of English association football club Aston Villa.
Krulak was born in Quantico, Virginia, on March 4, 1942, the son of Amy ( Chandler) and Victor H. Krulak. He graduated from Phillips Exeter Academy in Exeter, New Hampshire, in 1960, where he was classmates with novelist John Irving. Krulak then attended the United States Naval Academy, graduating in 1964 with a bachelor's degree. Krulak also holds a master's degree in labor relations from George Washington University (1973). He is a graduate of the Amphibious Warfare School (1968); the Army Command and General Staff College (1976); and the National War College (1982).
After his commissioning and graduation from The Basic School at Marine Corps Base Quantico, Krulak held a variety of command and staff positions. His command positions included: commanding officer of a platoon and two rifle companies during two tours of duty in Vietnam; commanding officer of Special Training Branch and Recruit Series at Marine Corps Recruit Depot San Diego, California (1966–1968); commanding officer of Counter-Guerilla Warfare School, Northern Training Area on Okinawa (1970), Company officer at the United States Naval Academy (1970–1973); commanding officer of the Marine Barracks at Naval Air Station North Island, California (1973–1976), and commanding officer, 3rd Battalion, 3rd Marines (1983–1985).
Krulak's staff assignments included: operations officer, 2nd Battalion, 9th Marines (1977–1978); chief of the Combat Arms Monitor Section at Headquarters Marine Corps, Washington, D.C. (1978–1979); executive assistant to the Director of Personnel Management, Headquarters Marine Corps (1979–1981); Plans Office, Fleet Marine Forces Pacific, Camp H.M. Smith, Hawaii (1982–1983); executive officer, 3rd Marine Regiment, 1st Marine Expeditionary Brigade; assistant chief of staff, maritime pre-positioning ships, 1st MEB; assistant chief of staff for operations, 1st Marine Expeditionary Brigade; and the military assistant to the assistant secretary of defense for command, control, communications and intelligence, Office of the Secretary of Defense.
Krulak was assigned duty as the deputy director of the White House Military Office in September 1987. While serving in this capacity, he was selected for promotion to brigadier general in November 1988. He was advanced to that grade on June 5, 1989, and assigned duties as the commanding general, 10th MEB/Assistant division commander, 2nd Marine Division, Fleet Marine Force Atlantic, at Marine Corps Base Camp Lejeune, North Carolina on July 10, 1989. On June 1, 1990, he assumed duties as the commanding general, 2nd Force Service Support Group Group/Commanding general, 6th Marine Expeditionary Brigade, Fleet Marine Force Atlantic and commanded the 2d FSSG during the Gulf War. He served in this capacity until July 12, 1991, and was assigned duty as assistant deputy chief of staff for manpower and reserve affairs (personnel Management/Personnel Procurement), Headquarters Marine Corps on August 5, 1991. He was advanced to major general on March 20, 1992. Krulak was assigned as commanding general, Marine Corps Combat Development Command, Quantico, on August 24, 1992, and was promoted to lieutenant general on September 1, 1992. On July 22, 1994, he was assigned as commander of Marine Forces Pacific/commanding general, Fleet Marine Force Pacific, and in March 1995 he was nominated to serve as the Commandant of the Marine Corps. On June, 29, he was promoted to general and assumed duties as the 31st commandant on June 30, 1995. He was relieved on June 30, 1999, by General James L. Jones.
In 1997, Krulak became a Life Member of the Sons of the Revolution in the State of California.
Krulak attracted some attention during his tenure as Commandant by his custom of delivering Christmas cookies to each Marine duty post in the Washington area.
Krulak joined MBNA America in September 1999 as chief administrative officer, responsible for personnel, benefits, compensation, education, and other administrative services. Krulak has served as the Senior Vice Chairman and Chief Executive Officer of MBNA Europe (2001–2005) and was based at the Chester campus in the UK. He was the executive vice chairman and chief administration officer of MBNA Corporation (2004–2005). He retired from MBNA in 2005.
Following the takeover of English football club Aston Villa by MBNA Chairman Randy Lerner in August 2006 and as of September 19, 2006, Krulak joined the board of Aston Villa as non-executive director where he posted on several fans forums. Krulak was generally referred to as "The General" by fans on these boards.
Krulak also serves on the boards of ConocoPhillips, Freeport-McMoran (formerly known as Phelps Dodge Corporation) and Union Pacific Corporation. In addition, he serves on the advisory council of Hope For The Warriors, a national non-profit dedicated to provide a full cycle of non-medical care to combat wounded service members, their families, and families of the fallen from each military branch.
Krulak was elected as the 13th President of Birmingham–Southern College in Birmingham, Alabama on March 21, 2011, and retired June 1, 2015. He received an honorary doctorate of Humane Letters from Birmingham-Southern College. The Krulak Institute Institute for Leadership, Experiential Learning, and Civic Engagement at Birmingham-Southern College is named for him.
Krulak is the Vice Chair of the Sweet Briar College Board of Directors. He joined the Board in the Summer of 2015.
General Krulak's decorations and medals include:
Krulak famously referred to the "Strategic Corporal" and the Three Block War as two of the key lessons identified from the deployments in Somalia, Haiti and Bosnia. These concepts are still considered vital in understanding the increasing complexity of modern battlefields.
Krulak explained some of his warfighting philosophy in an interview with Tom Clancy in Clancy's nonfiction book "Marine". Clancy referred to Krulak as "Warrior Prince of the Corps." Krulak also rewrote the Marine Corps' basic combat study text, "", incorporating his theories on operations in the modern battlefield.
Krulak is married to Zandi Meyers from Annapolis. They have two sons: CAPT. David C. Krulak, the current Commanding Officer for Naval Hospital Okinawa, Japan and Dr. Todd C. Krulak, PhD., a retired freelance rave DJ who is now a professor at Samford University; and five grandchildren: 2ndLT Brian Krulak, Katie, Mary, Matthew, and Charles.
He is the son of Lieutenant General Victor H. Krulak, Sr., and the younger brother of Commander Victor H. Krulak Jr, Navy Chaplain Corps and Colonel William Krulak, United States Marine Corps Reserve. Krulak's godfather was USMC general Holland McTyeire "Howlin' Mad" Smith. | https://en.wikipedia.org/wiki?curid=7740 |
Compaq
Compaq (a portmanteau of Compatibility And Quality, occasionally referred to as CQ prior to its final logo) was a company founded in 1982 that developed, sold, and supported computers and related products and services. Compaq produced some of the first IBM PC compatible computers, being the first company to legally reverse engineer the IBM Personal Computer. It rose to become the largest supplier of PC systems during the 1990s before being overtaken by HP in 2001. Struggling to keep up in the price wars against Dell, as well as with a risky acquisition of DEC, Compaq was acquired for US$25 billion by HP in 2002. The Compaq brand remained in use by HP for lower-end systems until 2013 when it was discontinued.
The company was formed by Rod Canion, Jim Harris and Bill Murto former Texas Instruments senior managers. Murto (SVP of sales) departed Compaq in 1987, while Canion (president and CEO) and Harris (SVP of engineering) left under a shakeup in 1991, which saw Eckhard Pfeiffer appointed president and CEO. Pfeiffer served through the 1990s. Ben Rosen provided the venture capital financing for the fledgling company and served as chairman of the board for 17 years from 1983 until September 28, 2000, when he retired and was succeeded by Michael Capellas, who served as the last chairman and CEO until its merger with HP.
Prior to its takeover the company was headquartered in northwest unincorporated Harris County, Texas, that now continues as HP's largest United States facility.
Compaq was founded in February 1982 by Rod Canion, Jim Harris and Bill Murto, three senior managers from semiconductor manufacturer Texas Instruments. The three of them had left due to lack of faith and loss of confidence in TI's management, and initially considered but ultimately decided against starting a chain of Mexican restaurants. Each invested $1,000 to form the company, which was founded with the temporary name Gateway Technology. The name "COMPAQ" was said to be derived from "Compatibility and Quality" but this explanation was an afterthought. The name was chosen from many suggested by Ogilvy & Mather, it being the name least rejected. The first Compaq PC was sketched out on a placemat by Ted Papajohn while dining with the founders in a Houston pie shop.
Their first venture capital came from Benjamin M. Rosen and Sevin Rosen Funds who helped the fledgling company secure $1.5 million to produce their initial computer. Overall, the founders managed to raise $25 million from venture capitalists, as this gave stability to the new company as well as providing assurances to the dealers or middlemen.
Unlike many startups, Compaq differentiated its offerings from the many other IBM clones by not focusing mainly on price, but instead concentrating on new features, such as portability and better graphics displays as well as performance—and all at prices comparable to those of IBM's PCs. In contrast to Dell Computer and Gateway 2000, Compaq hired veteran engineers with an average of 15 years experience, which lent credibility to Compaq's reputation of reliability among customers. Due to its partnership with Intel, Compaq was able to maintain a technological lead in the market place as it was the first one to come out with computers containing the next generation of each Intel processor.
Under Canion's direction, Compaq sold computers only through dealers to avoid potential competition that a direct sales channel would foster, which helped foster loyalty among resellers. By giving dealers considerable leeway in pricing Compaq's offerings, either a significant markup for more profits or discount for more sales, dealers had a major incentive to advertise Compaq.
During its first year of sales (second year of operation), the company sold 53,000 PCs for sales of $111 million, the first start-up to hit the $100 million mark that fast. Compaq went public in 1983 on the NYSE and raised $67 million. In 1986, it enjoyed record sales of $329 million from 150,000 PCs, and became the youngest-ever firm to make the Fortune 500. In 1987, Compaq hit the $1 billion revenue mark, taking the least amount of time to reach that milestone. By 1991, Compaq held the fifth place spot in the PC market with $3 billion in sales that year.
Two key marketing executives in Compaq's early years, Jim D'Arezzo and Sparky Sparks, had come from IBM's PC Group. Other key executives responsible for the company's meteoric growth in the late 80s and early 90s were Ross A. Cooley, another former IBM associate, who served for many years as SVP of GM North America; Michael Swavely, who was the company's chief marketing officer in the early years, and eventually ran the North America organization, later passing along that responsibility to Cooley when Swavely retired. In the United States, Brendan A. "Mac" McLoughlin (another long time IBM executive) led the company's field sales organization after starting up the Western U.S. Area of Operations. These executives, along with other key contributors, including Kevin Ellington, Douglas Johns, Steven Flannigan, and Gary Stimac, helped the company compete against the IBM Corporation in all personal computer sales categories, after many predicted that none could compete with the behemoth.
The soft-spoken Canion was popular with employees and the culture that he built helped Compaq to attract the best talent. Instead of headquartering the company in a downtown Houston skyscraper, Canion chose a West Coast-style campus surrounded by forests, where every employee had similar offices and no-one (not even the CEO) had a reserved parking spot. At semi-annual meetings, turnout was high as any employee could ask questions to senior managers.
In 1987, company co-founder Bill Murto resigned to study at a religious education program at the University of St. Thomas. Murto had helped to organize the company's marketing and authorized-dealer distribution strategy, and held the post of senior vice president of sales since June 1985. Murto was succeeded by Ross A. Cooley, director of corporate sales. Cooley would report to Michael S. Swavely, vice president for marketing, who has been given increased responsibility and the title of vice president for sales and marketing.
In November 1982, Compaq announced their first product, the Compaq Portable, a portable IBM PC compatible personal computer. It was released in March 1983 at $2995, considerably more affordable than the Canadian Hyperion. The Compaq Portable was one of the progenitors of today's laptop; some called it a "suitcase computer" for its size and the look of its case. It was the second IBM PC compatible, being capable of running all software that would run on an IBM PC. It was a commercial success, selling 53,000 units in its first year and generating $111 million in sales revenue. The Compaq Portable was the first in the range of the Compaq Portable series. Compaq was able to market a legal IBM clone because IBM mostly used "off the shelf" parts for their PC. Furthermore, Microsoft had kept the right to license the operating system to other computer manufacturers. The only part which had to be duplicated was the BIOS, which Compaq did legally by using clean room design at a cost of $1 million.
Unlike other companies, Compaq did not bundle application software with its computers. Vice President of Sales and Service H. L. Sparks said in early 1984:
Compaq instead emphasized PC compatibility, of which Future Computing in May 1983 ranked Compaq as among the "Best" examples. "Many industry observers think [Compaq] is poised for meteoric growth", "The New York Times" reported in March of that year. By October, when the company announced the Compaq Plus with a 10 MB hard drive, "PC Magazine" wrote of "the reputation for compatibility it built with its highly regarded floppy disk portable". Compaq computers remained the most compatible PC clones into 1984, and maintained its reputation for compatibility for years, even as clone BIOSes became available from Phoenix Technologies and other companies that also reverse engineered IBM's design, then sold their version to clone manufacturers.
On June 28, 1984, Compaq released the Compaq Deskpro, a 16-bit desktop computer using an Intel 8086 microprocessor running at 7.14 MHz. It was considerably faster than an IBM PC and was, like the original Compaq Portable, also capable of running IBM software. It was Compaq's first non-portable computer and began the Deskpro line of computers.
Compaq introduced the first PC based on Intel's new 80386 microprocessor, the Compaq Deskpro 386, in 1986. Bill Gates of Microsoft later said
An IBM-made 386 machine reached the market almost a year later. The Compaq 386 computer marked the first CPU change to the PC platform that was not initiated by IBM, but by that time Compaq was the 386 supplier of choice and IBM had lost its image of technical leadership.
For the first three months after announcement, the Deskpro 386 shipped with Windows/386. This was a version of Windows 2.1 adapted for the 80386 processor. Support for the virtual 8086 mode was added by Compaq engineers.
Compaq's technical leadership and the rivalry with IBM was emphasized when the SystemPro server was launched in late 1989 – this was a true server product with standard support for a second CPU and RAID, but also the first product to feature the EISA bus, designed in reaction to IBM's MCA (MicroChannel Architecture) which was incompatible with the original AT bus.
Although Compaq had become successful by being 100 percent IBM-compatible, it decided to continue with the original AT bus—which it renamed ISA—instead of licensing IBM's MCA. Prior to developing EISA Compaq had invested significant resources into reverse engineering MCA, but its executives correctly calculated that the $80 billion already spent by corporations on IBM-compatible technology would make it difficult for even IBM to force manufacturers to adopt the new MCA design. Instead of cloning MCA, Compaq formed an alliance with Hewlett Packard and seven other major manufacturers, known collectively as the "Gang of Nine", to develop EISA.
By 1989, the "Times" wrote that being the first to release a 80386-based personal computer made Compaq the leader of the industry and "hurt no company more - in prestige as well as dollars - than" IBM. The company was so influential that observers and its executives spoke of "Compaq compatible". "InfoWorld" reported that "In the [ISA market] Compaq is already IBM's equal in being seen as a safe bet", quoting a sell-side analyst describing it as "now "the" safe choice in personal computers". Even rival Tandy Corporation acknowledged Compaq's leadership, stating that within the Gang of Nine "when you have 10 people sit down before a table to write a letter to the president, someone has to write the letter. Compaq is sitting down at the typewriter".
Michael S. Swavely, president of Compaq's North American division since May 1989, took a six-month sabbatical in January 1991 (which would eventually become retirement effective on July 12, 1991). Eckhard Pfeiffer, then president of Compaq International, was named to succeed him. Pfeiffer also received the title of chief operating officer, with responsibility for the company's operations on a worldwide basis, so that Canion could devote more time to strategy. Swavely's abrupt departure in January led to rumors of turmoil in Compaq's executive suite, including friction between Canion and Swavely, likely as Swavely's rival Pfeiffer had received the number two leadership position. Swavely's U.S. marketing organization was losing ground with only 4% growth for Compaq versus 7% in the market, likely due to short supplies of the LTE 386s from component shortages, rivals that undercut Compaq's prices by as much as 35%, and large customers who did not like Compaq's dealer-only policy. Pfeiffer became president and CEO of Compaq later that year, as a result of a boardroom coup led by board chairman Ben Rosen that forced co-founder Rod Canion to resign as president and CEO.
Pfeiffer had joined Compaq from Texas Instruments, and established operations from scratch in both Europe and Asia. Pfeiffer was given US$20,000 to start up Compaq Europe He started up Compaq's first overseas office in Munich in 1984. By 1990, Compaq Europe was a $2 billion business and number two behind IBM in that region, and foreign sales contributed 54 percent of Compaq's revenues. Pfeiffer, while transplanting Compaq's U.S. strategy of dealer-only distribution to Europe, was more selective in signing up dealers than Compaq had been in the U. S. such that European dealers were more qualified to handle its increasingly complex products.
During the 1980s, under Canion's direction Compaq had focused on engineering, research, and quality control, producing high-end, high-performance machines with high profit margins that allowed Compaq to continue investing in engineering and next-generation technology. This strategy was successful as Compaq was considered a trusted brand, while many other IBM clones were untrusted due to being plagued by poor reliability. However, by the end of the eighties many manufacturers had improved their quality and were able to produce inexpensive PCs with off-the-shelf components, incurring none of the R&D costs which allowed them to undercut Compaq's expensive computers. Faced with lower-cost rivals such as Dell Computer, AST Research, and Gateway 2000, Compaq suffered a $71 million loss for that quarter, their first loss as a company, while the stock had dropped by over two-thirds. An analyst stated that "Compaq has made a lot of tactical errors in the last year and a half. They were trend-setters, now they are lagging". Canion initially believed that the 1990s recession was responsible for Compaq's declining sales but insisted that they would recover once the economy improved, however Pfeiffer's observation of the European market noted that it was competition as rivals could match Compaq at a fraction of the cost. Under pressure from Compaq's board to control costs as staff was ballooning at their Houston headquarters despite falling U.S. sales, while the number of non-U.S. employees had stayed constant, Compaq made its first-ever layoffs (1400 employees which was 12% of its workforce) while Pfeiffer was promoted to EVP and COO.
Rosen and Canion had disagreed about how to counter the cheaper Asian PC imports, as Canion wanted Compaq to build lower cost PCs with components developed in-house in order to preserve Compaq's reputation for engineering and quality, while Rosen believed that Compaq needed to buy standard components from suppliers and reach the market faster. While Canion developed an 18-month plan to create a line of low-priced computers, Rosen sent his own Compaq engineering team to Comdex without Canion's knowledge and discovered that a low-priced PC could be made in half the time and at lower cost than Canion's initiative. It was also believed that Canion's consensus-style management slowed the company's ability to react in the market, whereas Pfeiffer's autocratic style would be suited to price and product competition.
Rosen initiated a 14-hour board meeting, and the directors also interviewed Pfeiffer for several hours without informing Canion. At the conclusion, the board was unanimous in picking Pfeiffer over Canion. As Canion was popular with company workers, 150 employees staged an impromptu protest with signs stating "We love you, Rod." and taking out a newspaper ad saying "Rod, you are the wind beneath our wings. We love you." Canion declined an offer to remain on Compaq's board and was bitter about his ouster as he didn't speak to Rosen for years, although their relationship became cordial again. In 1999, Canion admitted that his ouster was justified, saying "I was burned out. I needed to leave. He [Rosen] felt I didn't have a strong sense of urgency". Two weeks after Canion's ouster, five other senior executives resigned, including remaining company founder James Harris as SVP of Engineering. These departures were motivated by an enhanced severance or early retirement, as well as an imminent demotion as their functions were to be shifted to vice presidents.
Under Pfeiffer's tenure as chief executive, Compaq entered the retail computer market with the Compaq Presario as one of the first manufacturers in the mid-1990s to market a sub-$1000 PC. In order to maintain the prices it wanted, Compaq became the first first-tier computer manufacturer to utilize CPUs from AMD and Cyrix. The two price wars resulting from Compaq's actions ultimately drove numerous competitors from the market, such as Packard Bell and AST Research. From third place in 1993, Compaq had overtaken Apple Computer and even surpassed IBM as the top PC manufacturer in 1994, as both IBM and Apple were struggling considerably during that time. Compaq's inventory and gross margins were better than that of its rivals which enabled it to wage the price wars.
Compaq had decided to make a foray into printers in 1989, and the first models were released to positive reviews in 1992. However, Pfeiffer saw that the prospects of taking on market leader Hewlett Packard (who had 60% market share) was tough, as that would force Compaq to devote more funds and people to that project than originally budgeted. Compaq ended up selling the printer business to Xerox and took a charge of $50 million.
On June 26, 1995, Compaq reached an agreement with Cisco Systems Inc. in order to get into networking, including digital modems, routers, and switches favored by small businesses and corporate departments, which was now a $4 billion business and the fastest-growing part of the computer hardware market. Compaq also built up a network engineering and marketing staff.
In 1996, despite record sales and profits at Compaq, Pfeiffer initiated a major management shakeup in the senior ranks. John T. Rose, who previously ran Compaq's desktop PC division, took over the corporate server business from SVP Gary Stimac who had resigned. Rose had joined Compaq in 1993 from Digital Equipment Corporation where he oversaw the personal computer division and worldwide engineering, while Stimac had been with Compaq since 1982 and was one of the longest-serving executives. Senior Vice-President for North America Ross Cooley announced his resignation effective at the end of 1996. CFO Daryl J. White, who joined the company in January, 1983 resigned in May, 1996 after 8 years as CFO. Michael Winkler, who joined Compaq in 1995 to run its portable computer division, was promoted to general manager of the new PC products group. Earl Mason, hired from Inland Steel effective in May 1996, immediately made an impact as the new CFO. Under Mason's guidance, Compaq utilized its assets more efficiently instead of focusing just on income and profits, which increased Compaq's cash from $700 million to nearly $5 billion in one year. Also Compaq's return on invested capital (after-tax operating profit divided by operating assets) has doubled to 50 percent from 25 percent in that period.
Compaq had been producing the PC chassis at its plant in Shenzhen, China to cut costs. In 1996, instead of expanding its own plant, Compaq asked a Taiwanese supplier to set up a new factory nearby to produce the mechanicals, with the Taiwanese supplier owning the inventory until it reached Compaq in Houston. Pfeiffer also introduced a new distribution strategy, to build PCs made-to-order which would eliminate the stockpile of computers in warehouses and cut the components inventory down to two weeks, with the supply chain from supplier to dealer linked by complex software.
Vice-President for Corporate Development Kenneth E. Kurtzman assembled five teams to examine Compaq's businesses and assess each unit's strategy and that of key rivals. Kurtzman's teams recommended to Pfeiffer that each business unit had to be first or second in its market within three years—or else Compaq should exit that line. Also, the company should no longer use profits from high-margin businesses to carry marginally profitable ones, as instead each unit must show a return on investment. Pfeiffer's vision was to make Compaq a full-fledged computer company, moving beyond its main business of manufacturing retail PCs and into the more lucrative business services and solutions that IBM did well at, such as computer servers which would also require more "customer handholding" from either the dealers or Compaq staff themselves.
Unlike IBM and HP, Compaq was not going to build up field technicians and programmers in-house as these could be costly assets, instead Compaq would leverage its partnerships (including these with Andersen Consulting and software maker SAP) to install and maintain corporate systems. This allowed Compaq to compete in the "big-iron market" without incurring the costs of running its own services or software businesses.
In January 1998, Compaq was at its height. CEO Pfeiffer boldly predicted that the Microsoft/Intel "Wintel" duopoly would be replaced by "Wintelpaq".
Pfeiffer also made several major (and some minor) acquisitions. In 1997, Compaq bought Tandem Computers, known for their NonStop server line. This acquisition instantly gave Compaq a presence in the higher end business computing market. Minor acquisitions centered around building a networking arm and included NetWorth (1998) based in Irving, Texas and Thomas-Conrad (1998) based in Austin, Texas. In 1997 Microcom was also acquired, based in Norwood, MA, which brought a line of modems, Remote Access Servers (RAS) and the popular Carbon Copy software.
In 1998, Compaq acquired Digital Equipment Corporation for a then-industry record of US$9 billion. The merger made Compaq, at the time, the world's second largest computer maker in the world in terms of revenue behind IBM. Digital Equipment, which had nearly twice as many employees as Compaq while generating half the revenue, had been a leading computer company during the 1970s and early 1980s. However, Digital had struggled during the 1990s, with high operating costs. For nine years the company had lost money or barely broke even, and had recently refocused itself as a "network solutions company". In 1995, Compaq had considered a bid for Digital but only became seriously interested in 1997 after Digital's major divestments and refocusing on the Internet. At the time of the acquisition, services accounted for 45 percent of Digital's revenues (about $6 billion) and their gross margins on services averaged 34 percent, considerably higher than Compaq's 25% margins on PC sales and also satisfying customers who had demanded more services from Compaq for years. Compaq had originally wanted to purchase only Digital's services business but that was turned down. When the announcement was made, it was initially viewed as a master stroke as it immediately gave Compaq a 22,000 person global service operation to help corporations handle major technological purchases (by 2001 services made up over 20% of Compaq's revenues, largely due to the Digital employees inherited from the merger), in order to compete with IBM. However it was also risky merger, as the combined company would have to lay off 2,000 employees from Compaq and 15,000 from Digital which would potentially hurt morale. Furthermore, Compaq fell behind schedule in integrating Digital's operations, which also distracted the company from its strength in low-end PCs where it used to lead the market in rolling out next-generation systems which let rival Dell grab market share. Reportedly Compaq had three consulting firms working to integrate Digital alone.
However, Pfeiffer had little vision for what the combined companies should do, or indeed how the three dramatically different cultures could work as a single entity, and Compaq struggled from strategy indecisiveness and lost focus, as a result being caught in between the low end and high end of the market. Mark Anderson, president of Strategic News Service, a research firm based in Friday Harbor, Wash. was quoted as saying, "The kind of goals he had sounded good to shareholders – like being a $50 billion company by the year 2000, or to beat I.B.M. – but they didn't have anything to do with customers. The new C.E.O. should look at everything Eckhard acquired and ask: did the customer benefit from that. If the answer isn't yes, they should get rid of it." On one hand, Compaq had previously dominated the PC market with its price war but was now struggling against Dell, which sold directly to buyers, avoiding the dealer channel and its markup, and built each machine to order to keep inventories and costs at a minimum. At the same time, Compaq, through its acquisitions of the Digital Equipment Corporation last year and Tandem Computer in 1997, had tried to become a major systems company, like IBM and Hewlett-Packard. While IBM and HP were able generate repeat business from corporate customers to drive sales of their different divisions, Compaq had not yet managed to make its newly acquired sales and services organizations work as seamlessly.
In early 1998, Compaq had the problem of bloated PC inventories. By summer 1998, Compaq was suffering from product-quality problems. Robert W. Stearns, SVP of Business Development, said "In [Pfeiffer's] quest for bigness, he lost an understanding of the customer and built what I call empty market share--large but not profitable", while Jim Moore, a technology strategy consultant with GeoPartners Research in Cambridge, Mass., says Pfeiffer "raced to scale without having economies of scale." The "colossus" that Pfeiffer built up was not nimble enough to adapt to the fast-changing computer industry. That year Compaq forecast demand poorly and overshipped too many PCs, causing resellers to dump them at fire sale prices, and since Compaq protected resellers from heavy losses it cost them two quarters of operating profits.
Pfeiffer also refused to develop a potential successor, rebuffing Rosen's suggestion to recruit a few executives to create the separate position of Compaq president. The board complained that Pfeiffer was too removed from management and the rank-and-file, as he surrounded himself with a "clique" of Chief Financial Officer Earl Mason, Senior Vice-President John T. Rose, and Senior Vice-President of Human Resources Hans Gutsch. Current and former Compaq employees complained that Gutsch was part of a group of senior executives, dubbed the "A team", who controlled access to Pfeiffer. Gutsch was said to be a "master of corporate politics, pitting senior vice presidents against each other and inserting himself into parts of the company that normally would not be under his purview". Gutsch, who oversaw security, had an extensive security system and guard station installed on the eight floor of CCA-11, where the company's senior vice presidents worked. There were accusations that Gutsch and others sought to divide top management, although this was regarded by others as sour grapes on the part of executives who were shut out of planning that involved the acquisitions of Tandem and Digital Equipment Corp. Pfeiffer reduced the size of the group working on the deal due to news leaks, saying "We cut the team down to the minimum number of people - those who would have to be directly involved, and not one person more". Robert W. Stearns, Compaq's senior vice president for business development, with responsibility for mergers and acquisitions, had opposed the acquisition of Digital as the cultural differences between both companies were too great, and complained that he was placed on the "B team" as a result.
Compaq entered 1999 with strong expectations. Fourth-quarter 1998 earnings reported in January 1999 beat expectations by six cents a share with record 48 percent growth. The company launched "Compaq.com" as the key for its new direct sales strategy, and planned an IPO for AltaVista toward the end of 1999 in order to capitalize on the dotcom bubble. However, by February 1999, analysts were sceptical of Compaq's plan to sell both direct and to resellers. Compaq was hit with two class-action lawsuits, as a result of CFO Earl Mason, SVP John Rose, and other executives selling US$50 million of stock before a conference call with analysts, where they noted that demand for PCs was slowing down.
On April 17, 1999, just nine days after Compaq reported first-quarter profit being at half of what analysts had expected, the latest in a string of earnings disappointments, Pfeiffer was forced to resign as CEO in a coup led by board chairman Ben Rosen. Reportedly, at the special board meeting held on April 15, 1999, the directors were unanimous in dismissing Pfeiffer. The company's stock had fallen 50 percent since its all-time high in January 1999. Compaq shares, which traded as high as $51.25 early in 1999, dropped 23 percent on April 12, 1999, the first day of trading after the first-quarter announcement and closed the following Friday at $23.62. During three out of the last six quarters of Pfeiffer's tenure, the company's revenues or earnings had missed expectations. While rival Dell Computer had 55% growth in U.S. PC sales in the first quarter of 1999, Compaq could only manage 10%. Rosen suggested that the accelerating change brought about by the Internet had overtaken Compaq's management team, saying "As a company engaged in transforming its industry for the Internet era, we must have the organizational flexibility necessary to move at Internet speed." In a statement, Pfeiffer said "Compaq has come a long way since I joined the company in 1983" and "under Ben's guidance, I know this company will realize its potential." Rosen's priority was to have Compaq catchup as an E-commerce competitor, and he also moved to streamline operations and reduce the indecision that plagued the company.
Roger Kay, an analyst at International Data Corporation, observed that Compaq's behavior at times seemed like a personal vendetta, noting that "Eckhard has been so obsessed with staying ahead of Dell that they focused too hard on market share and stopped paying attention to profitability and liquidity. They got whacked in a price war that they started." Subsequent earnings releases from Compaq's rivals, Dell, Gateway, IBM, and Hewlett-Packard suggested that the problems were not affecting the whole PC industry as Pfeiffer had suggested. Dell and Gateway sold direct, which helped them to avoid Compaq's inventory problems and compete on price without dealer markups, plus Gateway sold web access and a broad range of software tailored to small businesses. Hewlett-Packard's PC business had similar challenges like Compaq but this was offset by HP's extremely lucrative printer business, while IBM sold PCs at a loss but used them to lock in multi-year services contracts with customers.
After Pfeiffer's resignation, the board established an office of the CEO with a triumvirate of directors; Rosen as interim CEO and vice chairmen Frank P. Doyle and Robert Ted Enloe III. They began "cleaning house", as shortly afterward many of Pfeiffer's top executives resigned or were pushed out, including John J. Rando, Earl L. Mason, and John T. Rose. Rando, senior vice president and general manager of Compaq Services, was a key player during the merger discussions and the most senior executive from Digital to remain with Compaq after the acquisition closed and had been touted by some as the heir-apparent to Pfeiffer. Rando's division had performed strongly as it had sales of $1.6 billion for the first quarter compared to $113 million in 1998, which met expectations and was anticipated to post accelerated and profitable growth going forward. At the time of Rando's departure, Compaq Services ranked third behind those of IBM and EDS, while slightly ahead of Hewlett-Packard's and Andersen Consulting, however customers switched from Digital and Tandem technology-based workstations to those of HP, IBM, and Sun Microsystems. Mason, senior vice president and chief financial officer, had previously been offered the job of chief executive of Alliant Foodservice, Inc., a foodservice distributor based in Chicago, and he informed Compaq's board that he accepted the offer. Rose, senior vice president and general manager of Compaq's Enterprise Computing group, resigned effective as of June 3 and was succeeded by Tandem veteran Enrico Pesatori. Rose was reportedly upset that he was not considered for the CEO vacancy, which became apparent once Michael Capellas was named COO. While Enterprise Computing, responsible for engineering and marketing of network servers, workstations and data-storage products, reportedly accounted for one third of Compaq's revenues and likely the largest part of its profits, it was responsible for the earnings shortfall in Q1 of 1999. In addition, Rose was part of the "old guard" close to former CEO Pfeiffer, and he and other Compaq executives had been criticized at the company's annual meeting for selling stock before reporting the sales slowdown. Rose was succeeded by SVP Enrico Pesatori, who had previously worked as a senior executive at Olivetti, Zenith Data Systems, Digital Equipment Corp. and Tandem Computers. Capellas was appointed COO after pressure mounted on Rosen to find a permanent CEO, however it was reported that potential candidates did not want to work under Rosen as chairman. Around the same time Pesatori was placed in charge of the newly created Enterprise Solutions and Services Group, making him Compaq's second most powerful executive in operational responsibility after Capellas.
Pfeiffer's permanent replacement was Michael Capellas, who had been serving as Compaq's SVP and CIO for under a year. A couple months after Pfeiffer's ouster, Capellas was elevated to interim chief operating officer on June 2, 2000, and was soon appointed president and CEO. Capellas also assumed the title of chairman on September 28, 2000 when Rosen stepped down from the board of directors. At his retirement, Rosen proclaimed "These are great achievements—to create 65,000 jobs, $40 billion in sales and $40 billion in market value, all starting with a sketch and a dream".
Capellas was able to restore some of the luster lost in the latter part of the Pfeiffer era and he repaired the relationship with Microsoft which had deteriorated under his predecessor's tenure.
However Compaq still struggled against lower-cost competitors with direct sales channels such as Dell who took over the top spot of PC manufacturer from Compaq in 2001. Compaq relied significantly on reseller channels, so their criticism caused Compaq to retreat from its proposed direct sales plan, although Capellas maintained that he would use the middlemen to provide value-added services. Despite falling to No. 2 among PC manufacturers, Capellas proclaimed "We are No. 2 in the traditional PC market, but we're focused on industry leadership in the next generation of Internet access devices and wireless mobility. That's where the growth and the profitability will be." The company's longer-term strategy involves extending its services to servers and storage products, as well as handheld computers such as the iPAQ PocketPC which accounted for 11 percent of total unit volume.
During November 1999, Compaq began to work with Microsoft to create the first in a line of small-scale, web-based computer systems called MSN Companions.
In 1998, Compaq also signed new sales and equipment alliance with NaviSite. Under the pact, Compaq agreed to promote and sell NaviSite Web hosting services. In return, NaviSite took Compaq as a preferred provider for its storage and Intel-based servers.
Compaq struggled as a result of the collapse of the Dot-com bubble bust, which hurt sales of their high-end systems in 2001 and 2002, and they managed only a small profit in a few quarters during these years. They also accumulated $1.7 billion in short-term debt around this time. The stock price of Compaq, which was around $25 when Capellas became CEO, was trading at half that by 2002.
In 2002, Compaq signed a merger agreement with Hewlett-Packard for $24.2 billion, including $14.45 billion for goodwill, where each Compaq share would be exchanged for 0.6325 of a Hewlett-Packard share. There would be a termination fee of US$675 million that either company would have to pay the other to break the merger. Compaq shareholders would own 36% of the combined company while HP's would have 64%. Hewlett-Packard had reported yearly revenues of $47 billion, while Compaq's was $40 billion, and the combined company would have been close to IBM's $90 billion revenues. It was projected to have $2.5 billion in annual cost savings by mid-2004. The expected layoffs at Compaq and HP, 8500 and 9000 jobs, respectively, would leave the combined company with a workforce of 145,000. The companies would dole out a combined $634.5 million in bonuses to prevent key employees from leaving if shareholders approve the proposed merger, with $370.1 million for HP employees and $264.4 million for Compaq employees.
Both companies had to seek approval from their shareholders through separate special meetings. While Compaq shareholders unanimously approved the deal, there was a public proxy battle within HP as the deal was strongly opposed by numerous large HP shareholders, including the sons of the company founders, Walter Hewlett and David W. Packard, as well as the California Public Employees’ Retirement System (CalPERS) and the Ontario Teachers Pension Plan. Walter Hewlett only reluctantly approved the merger, in his duty as a member of the board of directors, since the merger agreement "called for unanimous board approval in order to ensure the best possible shareholder reception". While supporters of the merger argued that there would be economies of scale and that the sales of PCs would drive sales of printers and cameras, Walter Hewlett was convinced that PCs were a low-margin but risky business that would not contribute and would likely dilute the old HP's traditionally profitable Imaging and Printing division. David W. Packard in his opposition to the deal "[cited] massive layoffs as an example of this departure from HP’s core values...[arguing] that although the founders never guaranteed job security, 'Bill and Dave never developed a premeditated business strategy that treated HP employees as expendable.'" Packard further stated that "[Carly] Fiorina’s high-handed management and her efforts to reinvent the company ran counter to the company’s core values as established by the founders". The founders' families who controlled a significant amount of HP shares were further irked because Fiorina had made no attempt to reach out to them and consult about the merger, instead they received the same standard roadshow presentation as other investors.
Analysts on Wall Street were generally critical of the merger, as both companies had been struggling before the announcement, and the stock prices of both companies dropped in the months after the merger agreement was made public. Particularly rival Dell made gains from defecting HP and Compaq customers who were wary of the merger. Carly Fiorina, initially seen as HP's savior when she was hired as CEO back in 1999, had seen the company's stock price drop to less than half since she assumed the position, and her job was said to be on shaky ground before the merger announcement. HP's offer was regarded by analysts to be overvaluing Compaq, due to Compaq's shaky financial performance in the past recent years (there were rumors that it could run out of money in 12 months and be forced to cease business operations had it stayed independent), as well as Compaq's own more conservative valuation of its assets. Detractors of the deal noted that buying Compaq was a "distraction" that would not directly help HP take on IBM's breadth or Dell Computer's direct sales model. Plus there were significant cultural differences between HP and Compaq; which made decisions by consensus and rapid autocratic styles, respectively. One of Compaq's few bright spots was its services business, which was outperforming HP's own services division.
The merger was approved by HP shareholders only after the narrowest of margins, and allegations of vote buying (primarily involving an alleged last-second back-room deal with Deutsche Bank) haunted the new company. It was subsequently disclosed that HP had retained Deutsche Bank's investment banking division in January 2002 to assist in the merger. HP had agreed to pay Deutsche Bank $1 million guaranteed, and another $1 million contingent upon approval of the merger. On August 19, 2003, the U.S. SEC charged Deutsche Bank with failing to disclose a material conflict of interest in its voting of client proxies for the merger and imposed a civil penalty of $750,000. Deutsche Bank consented without admitting or denying the findings.
Compaq's pre-merger ticker symbol was CPQ. This was combined with Hewlett-Packard's ticker symbol (HWP) to create the current ticker symbol (HPQ).
Capellas, Compaq's last chairman and CEO, became president of the post-merger Hewlett-Packard, under chairman and CEO Carly Fiorina, to ease the integration of the two companies. However, Capellas was reported not to be happy with his role, being said not to be utilized and being unlikely to become CEO as the board supported Fiorina. Capellas stepped down as HP president on November 12, 2002, after just six months on the job, to become CEO of MCI Worldcom where he would lead its acquisition by Verizon. Capellas' former role of president was not filled as the executives who reported to him then reported directly to the CEO.
Fiorina helmed the post-merger HP for nearly three years after Capellas left. HP laid off thousands of former Compaq, DEC, HP, and Tandem employees, its stock price generally declined and profits did not perk up. Several senior executives from the Compaq side including Jeff Clarke and Peter Blackmore would resign or be ousted from the post-merger HP. Though the combination of both companies' PC manufacturing capacity initially made the post-merger HP number one, it soon lost the lead and further market share to Dell which squeezed HP on low end PCs. HP was also unable to compete effectively with IBM in the high-end server market. In addition, the merging of the stagnant Compaq computer assembly business with HP's lucrative printing and imaging division was criticized for obstructing the profitability of the printing/imaging segment. Overall, it has been suggested that the purchase of Compaq was not a good move for HP, due to the narrow profit margins in the commoditized PC business, especially in light of IBM's 2004 announcement to sell its PC division to Lenovo. "The Inquirer" noted that the continued low return on investment and small margins of HP's personal computer manufacturing business, now named the Personal Systems Group, "continues to be what it was in the individual companies, not much more than a job creation scheme for its employees". One of the few positives was Compaq's sales approach and enterprise focus that influenced the newly combined company's strategy and philosophy.
In February 2005, the board of directors ousted Fiorina, with CFO Robert Wayman being named interim CEO. Former Compaq CEO Capellas was mentioned by some as a potential successor, but several months afterwards, Mark Hurd was hired as president and CEO of HP. Hurd separated the PC division from the imaging and printing division and renamed it the Personal Systems Group, placing it under the leadership of EVP Todd R. Bradley. Hewlett Packard's PC business has since been reinvigorated by Hurd's restructuring and now generates more revenue than the traditionally more profitable printers. By late 2006, HP had retaken the #1 sales position of PCs from Dell, which struggled with missed estimates and poor quality, and held that rank until supplanted in the mid-2010s by Lenovo.
Most Compaq products have been re-branded with the HP nameplate, such as the company's market leading ProLiant server line (now owned by Hewlett Packard Enterprise, which spun off from HP in 2015), while the Compaq brand was repurposed for some of HP's consumer-oriented and budget products, notably Compaq Presario PCs. HP's business computers line was discontinued in favour of the Compaq Evo line, which was rebranded HP Compaq. HP's Jornada PDAs were replaced by Compaq iPAQ PDAs, which were renamed HP iPAQ. Following the merger, all Compaq computers were shipped with HP software.
In May 2007, HP announced in a press release a new logo for their Compaq Division to be placed on the new model Compaq Presarios.
In 2008, HP reshuffled its business line notebooks. The "Compaq" name from its "HP Compaq" series was originally used for all of HP's business and budget notebooks. However, the HP EliteBook line became the top of the business notebook lineup while the HP Compaq B series became its middle business line. As of early 2009, the "HP ProBook" filled out HP's low end business lineup.
In 2009, HP sold part of Compaq's former headquarters to the Lone Star College System.
On August 18, 2011, then-CEO of HP Leo Apotheker announced plans for a partial or full spinoff of the Personal Systems Group. The PC unit had the lowest profit margin although it accounted for nearly a third of HP's overall revenues in 2010. HP was still selling more PCs than any other vendor, shipping 14.9 million PCs in the second quarter of 2011 (17.5% of the market according to Gartner), while Dell and Lenovo were tied for second place, each with more than a 12% share of the market and shipments of over 10 million units. However, the announcement of the PC spinoff (concurrent with the discontinuation of WebOS, and the purchase of Autonomy Corp. for $10 billion) was poorly received by the market, and after Apotheker's ouster, plans for a divestiture were cancelled. In March 2012, the printing and imaging division was merged into the PC unit. In October 2012, according to Gartner, Lenovo took the lead as the number one PC manufacturer from HP, while IDC ranked Lenovo just right behind HP. In Q2 2013, Forbes reported that Lenovo ranked ahead of HP as the world's number-one PC supplier.
HP discontinued the Compaq brand name in the United States in 2013. In 2015, the Argentine company Grupo Newsan acquired the brand's license, alongside with a $3 million investment, and developed two new lines of Presario notebooks for the local market over the course of the year. By March 2019, Compaq's Argentine web site went offline, with the last archived copy dated October 2018, featuring the same models introduced in 2016.
Compaq World Headquarters (now HP United States) campus consisted of of land which contained 15 office buildings, 7 manufacturing buildings, a product conference center, an employee cafeteria, mechanical laboratories, warehouses, and chemical handling facilities.
Instead of headquartering the company in a downtown Houston skyscraper, then-CEO Rod Canion chose a West Coast-style campus surrounded by forests, where every employee had similar offices and no-one (not even the CEO) had a reserved parking spot. As it grew, Compaq became so important to Houston that it negotiated the expansion of Highway 249 in the late 1980s, and many other technology companies appeared in what became known as the "249 Corridor".
After Canion's ouster, senior vice-president of human resources, Hans W. Gutsch, oversaw the company's facilities and security. Gutsch had an extensive security system and guard station installed on the eight floor of CCA-1, where the company's senior vice presidents had their offices. Eckhard Pfeiffer, president and CEO, introduced a whole series of executive perks to a company that had always had an egalitarian culture; for instance, he oversaw the construction of an executive parking garage, previously parking places had never been reserved.
On August 31, 1998, the Compaq Commons was opened in the headquarters campus, which featured a conference center, an employee convenience store, a wellness center, and an employee cafeteria.
In 2009, HP sold part of Compaq's former headquarters to the Lone Star College System. Hewlett Packard Buildings #7 & #8, two eight-story reinforced concrete buildings totaling 450,000 square feet, plus a 1,200-car parking garage and a central chiller plant, were all deemed by the college to be too robust and costly to maintain so they were demolished by implosion on September 18, 2011.
Compaq originally competed directly against IBM, manufacturing computer systems equivalent with the IBM PC, as well as Apple Computer. In the 1990s, as IBM's own PC division declined, Compaq faced other IBM PC Compatible manufacturers like Dell Computer, Packard Bell, AST Research, and Gateway 2000.
By the mid-1990s, Compaq's price war had enabled it to overtake IBM and Apple, while other IBM PC Compatible manufacturers such as Packard Bell and AST were driven from the market.
Dell became the number-one supplier of PCs in 2001.
At the time of their 2002 merger, Compaq and HP were the second and third largest PC manufacturers, so their combination made them number one. However, the combined HP-Compaq struggled and fell to second place behind Dell from 2003 to 2006. Due to Dell's struggles in late 2006, HP has led all PC vendors from 2007 to 2012.
During its existence as a division of HP, Compaq primarily competed against other budget-oriented personal computer series from manufacturers including Acer, Lenovo, and Toshiba. Most of Compaq's competitors except Dell were later acquired by bigger rivals like Acer (Gateway 2000 and Packard Bell) and Lenovo absorbing IBM's PC division.
Lenovo has been the PC world leader from 2013 onwards.
Before its merger with HP, Compaq sponsored the Williams Formula One team when it was still powered by BMW engines. HP inherited and continued the sponsorship deal for a few years. | https://en.wikipedia.org/wiki?curid=7742 |
Chet Atkins
Chester Burton Atkins (June 20, 1924 – June 30, 2001), known as "Mr. Guitar" and "The Country Gentleman", was an American musician, occasional vocalist, songwriter, and record producer who, along with Owen Bradley, Bob Ferguson and others, created the country music style that came to be known as the Nashville sound, which expanded country music's appeal to adult pop music fans. He was primarily known as a guitarist. He also played the mandolin, fiddle, banjo, and ukulele.
Atkins's signature picking style was inspired by Merle Travis. Other major guitar influences were Django Reinhardt, George Barnes, Les Paul, and, later, Jerry Reed. His distinctive picking style and musicianship brought him admirers inside and outside the country scene, both in the United States and abroad. Atkins spent most of his career at RCA Victor and produced records for the Browns, Hank Snow, Porter Wagoner, Norma Jean, Dolly Parton, Dottie West, Perry Como, Floyd Cramer, Elvis Presley, the Everly Brothers, Eddy Arnold, Don Gibson, Jim Reeves, Jerry Reed, Skeeter Davis, Waylon Jennings, Roger Whittaker, and many others.
"Rolling Stone" credited Atkins with inventing the "popwise 'Nashville sound' that rescued country music from a commercial slump," and ranked him number 21 on their list of "The 100 Greatest Guitarists Of All Time." Among many other honors, Atkins received 14 Grammy Awards and the Grammy Lifetime Achievement Award. He also received nine Country Music Association awards for Instrumentalist of the Year. He was inducted into the Rock & Roll Hall of Fame, the Country Music Hall of Fame and Museum, and the Musicians Hall of Fame and Museum. George Harrison was also inspired by Chet Atkins; early Beatles songs such as "All My Loving" show the influence.
Atkins was born on June 20, 1924, in Luttrell, Tennessee, near Clinch Mountain. His parents divorced when he was six years old, after which he was raised by his mother. He was the youngest of three boys and a girl. He started out on the ukulele, later moving on to the fiddle, but made a swap with his brother, Lowell, when he was nine: an old pistol and some chores for a guitar. He stated in his 1974 autobiography, "We were so poor and everybody around us was so poor that it was the forties before anyone even knew there had been a depression." Forced to relocate to Fortson, Georgia, outside of Columbus, to live with his father because of a critical asthma condition, Atkins was a sensitive youth who made music his obsession. Because of his illness, he was forced to sleep in a straight-back chair to breathe comfortably. On those nights, he played his guitar until he fell asleep holding it, a habit that lasted his whole life. While living in Fortson, he attended the historic Mountain Hill School. He returned in the 1990s to play a series of charity concerts to save the school from demolition.
Stories have been told about the very young Chet, who, when a friend or relative would come to visit and play guitar, would crowd in and put his ear so close to the instrument that it became difficult for the visitor to play.
Atkins became an accomplished guitarist while he was in high school. He used the restroom in the school to practice, because it had good acoustics. His first guitar had a nail for a nut and was so bowed that only the first few frets could be used. He later purchased a semi-acoustic electric guitar and amp, but he had to travel many miles to find an electrical outlet, since his home didn't have electricity.
Later in life, he lightheartedly gave himself (along with John Knowles, Marcel Dadi, Tommy Emmanuel, Steve Wariner, and Jerry Reed) the honorary degree CGP ("Certified Guitar Player").
In 2011, his daughter Merle Atkins Russell bestowed the CGP degree on his longtime sideman Paul Yandell. She then declared no more CGPs would be allowed by the Atkins estate.
His half-brother, Jim, was a successful guitarist who worked with the Les Paul Trio in New York.
Atkins did not have a strong style of his own until 1939, when (while still living in Georgia) he heard Merle Travis picking over WLW radio. This early influence dramatically shaped his unique playing style. Whereas Travis's right hand used his index finger for the melody and thumb for bass notes, Atkins expanded his right-hand style to include picking with his first three fingers, with the thumb on bass.
Chet Atkins was an amateur radio general class licensee. Formerly using the call sign WA4CZD, he obtained the vanity call sign W4CGP in 1998 to include the CGP designation, which supposedly stood for "Certified Guitar Picker". He was a member of the American Radio Relay League.
After dropping out of high school in 1942, Atkins landed a job at WNOX-AM radio in Knoxville, where he played fiddle and guitar with the singer Bill Carlisle and the comic Archie Campbell and became a member of the station's Dixieland Swingsters, a small swing instrumental combo. After three years, he moved to WLW-AM in Cincinnati, Ohio, where Merle Travis had formerly worked.
After six months, he moved to Raleigh and worked with Johnnie and Jack before heading for Richmond, Virginia, where he performed with Sunshine Sue Workman. Atkins's shy personality worked against him, as did the fact that his sophisticated style led many to doubt he was truly "country." He was fired often, but was soon able to land another job at another radio station on account of his unique playing ability.
Atkins and Jethro Burns (of Homer and Jethro) married twin sisters, Leona and Lois Johnson, who sang as Laverne and Fern Johnson, the Johnson Sisters. Leona Atkins outlived her husband by eight years, dying in 2009 at the age of 85.
Travelling to Chicago, Atkins auditioned for Red Foley, who was leaving his star position on WLS-AM's "National Barn Dance" to join the Grand Ole Opry. Atkins made his first appearance at the Opry in 1946 as a member of Foley's band. He also recorded a single for Nashville-based Bullet Records that year. That single, "Guitar Blues", was fairly progressive, including a clarinet solo by the Nashville dance band musician Dutch McMillan, with Owen Bradley on piano. He had a solo spot on the Opry, but when that was cut, Atkins moved on to KWTO in Springfield, Missouri. Despite the support of executive Si Siman, however, he soon was fired for not sounding "country enough".
While working with a Western band in Denver, Colorado, Atkins came to the attention of RCA Victor. Siman had been encouraging Steve Sholes to sign Atkins, as his style (with the success of Merle Travis as a hit recording artist) was suddenly in vogue. Sholes, A&R director of country music at RCA, tracked Atkins down in Denver.
He made his first RCA Victor recordings in Chicago in 1947, but they did not sell. He did some studio work for RCA that year, but had relocated to Knoxville again where he worked with Homer and Jethro on WNOX's new Saturday night radio show "The Tennessee Barn Dance" and the popular "Midday Merry Go Round".
In 1949, he left WNOX to join June Carter with Mother Maybelle and the Carter Sisters on KWTO. This incarnation of the old Carter Family featured Maybelle Carter and daughters June, Helen, and Anita. Their work soon attracted attention from the Grand Ole Opry. The group relocated to Nashville in the mid-1950s. Atkins began working on recording sessions and performing on WSM-AM and the Opry. Atkins became a member of the Opry in the 1950s.
While he had not yet had a hit record for RCA Victor, his stature was growing. He began assisting Sholes as a session leader when the New York–based producer needed help organizing Nashville sessions for RCA Victor artists. Atkins's first hit single was "Mr. Sandman", followed by "Silver Bell", which he recorded as a duet with Hank Snow. His albums also became more popular. He was featured on ABC-TV's "The Eddy Arnold Show" in the summer of 1956 and on "Country Music Jubilee" in 1957 and 1958 (by then renamed "Jubilee USA").
In addition to recording, Atkins was a design consultant for Gretsch, which manufactured a popular Chet Atkins line of electric guitars from 1955–1980. He became manager of RCA Victor's Nashville studios, eventually inspiring and seeing the completion of the legendary RCA Studio B, the first studio built specifically for the purpose of recording on the now-famous Music Row. Also later on, Chet and Owen Bradley would become instrumental in the creation of studio B’s adjacent building RCA Studio A as well.
When Sholes took over pop production in 1957—a result of his success with Elvis Presley—he put Atkins in charge of RCA Victor's Nashville division. With country music record sales declining as rock and roll became more popular, Atkins and Bob Ferguson took their cue from Owen Bradley and eliminated fiddles and steel guitar as a means of making country singers appeal to pop fans. This became known as the Nashville sound, which Atkins said was a label created by the media for a style of recording during that period intended to keep country (and their jobs) viable.
Atkins used the Jordanaires and a rhythm section on hits such as Jim Reeves's "Four Walls" and "He'll Have to Go" and Don Gibson's "Oh Lonesome Me" and "Blue Blue Day". The once-rare phenomenon of having a country hit cross over to pop success became more common. He and Bradley had essentially put the producer in the driver's seat, guiding an artist's choice of material and the musical background.
Atkins made his own records, which usually visited pop standards and jazz, in a sophisticated home studio, often recording the rhythm tracks at RCA and adding his solo parts at home, refining the tracks until the results satisfied him. Guitarists of all styles came to admire various Atkins albums for their unique musical ideas and in some cases experimental electronic ideas. In this period, he became known internationally as "Mister Guitar", inspiring an album, "Mister Guitar", engineered by both Bob Ferris and Bill Porter, Ferris's replacement.
At the end of March 1959, Porter took over as chief engineer at RCA's Nashville studio, in the space eventually known as Studio B after the facility expanded with a second studio in 1960. (At the time, RCA's sole Nashville studio had no letter designation.) Porter soon helped Atkins get a better reverberation sound from the studio's German effects device, an EMT plate reverb. With his golden ear, Porter found the studio's acoustics to be problematic, and he devised a set of acoustic baffles to hang from the ceiling, then selected positions for microphones based on resonant room modes. The sound of the recordings improved significantly, and the studio achieved a string of successes. The Nashville sound became more dynamic. In later years, when Bradley asked how he achieved his sound, Atkins told him "it was Porter." Porter described Atkins as respectful of musicians when recording—if someone was out of tune, he would not single that person out by name. Instead, he would say something like, "we got a little tuning problem ... Everybody check and see what's going on." If that did not work, Atkins would instruct Porter to turn the offending player down in the mix. When Porter left RCA in late-1964, Atkins said, "the sound was never the same, never as great."
Atkins's trademark "Atkins style" of playing uses the thumb and first two or sometimes three fingers of the right hand. He developed this style from listening to Merle Travis, occasionally on a primitive radio. He was sure no one could play that articulately with just the thumb and index finger (which was exactly how Travis played), and he assumed it required the thumb and two fingers—and that was the style he pioneered and mastered.
He enjoyed jamming with fellow studio musicians, and they were asked to perform at the Newport Jazz Festival in 1960. That performance was cancelled because of rioting, but a live recording of the group ("After the Riot at Newport") was released. Atkins performed by invitation at the White House for every U.S. President from John F. Kennedy through to George H. W. Bush. Atkins was a member of the Million Dollar Band during the 1980s. He is also well known for his song "Yankee Doodle Dixie", in which he played "Yankee Doodle" and "Dixie" simultaneously, on the same guitar.
Before his mentor Sholes died in 1968, Atkins had become vice president of RCA's country division. In 1987, he told "Nine-O-One Network" magazine that he was "ashamed" of his promotion: "I wanted to be known as a guitarist and I know, too, that they give you titles like that in lieu of money. So beware when they want to make you vice president." He had brought Waylon Jennings, Willie Nelson, Connie Smith, Bobby Bare, Dolly Parton, Jerry Reed, and John Hartford to the label in the 1960s and inspired and helped countless others. He took a considerable risk during the mid-1960s, when the civil rights movement sparked violence throughout the South, by signing country music's first African-American singer, Charley Pride, who sang rawer country than the smoother music Atkins had pioneered.
Atkins's biggest hit single came in 1965, with "Yakety Axe", an adaptation of "Yakety Sax", by his friend, the saxophonist Boots Randolph. He rarely performed in those days and eventually hired other RCA producers, such as Bob Ferguson and Felton Jarvis, to lessen his workload.
In the 1970s, Atkins became increasingly stressed by his executive duties. He produced fewer records, but could still turn out hits such as Perry Como's 1973 pop hit "And I Love You So". He recorded extensively with close friend and fellow picker Jerry Reed, who had become a hit artist in his own right. A 1973 diagnosis of colon cancer, however, led Atkins to redefine his role at RCA, to allow others to handle administration while he went back to his first love, the guitar, often recording with Reed or even Jethro Burns from Homer and Jethro (his brother-in-law) after Homer died in 1971. Atkins would turn over his administrative duties to Jerry Bradley, son of Owen, in 1973 at RCA.
Atkins did little production work at RCA after stepping down and in fact, had hired producers at the label in the 1960s, among them Bob Ferguson and Felton Jarvis. As a recording artist, Atkins grew disillusioned with RCA in the late 1970s. He felt stifled because the record company would not let him branch into jazz. He had also produced late 60's jazz recordings by Canadian guitarist Lenny Breau, a friend and protege. His mid-1970s collaborations with one of his influences, Les Paul, "Chester & Lester" and "Guitar Monsters", had already reflected that interest; "Chester & Lester" was one of the best-selling recordings of Atkins's career. At the same time, he grew dissatisfied with the direction Gretsch (no longer family-owned) was going and withdrew his authorization for them to use his name and began designing guitars with Gibson. Atkins ended his 35-year association with RCA in 1982 and signed with Columbia Records, for whom he produced a debut album in 1983.
Jazz had always been a strong love of his, and often in his career he was criticized by "pure" country musicians for his jazz influences. He also said on many occasions that he did not like being called a "country guitarist," insisting that he was "a guitarist, period." Although he played by ear and was a masterful improviser, he was able to read music and even performed some classical guitar pieces. When Roger C. Field, a friend, suggested to him in 1991 that he record and perform with a female singer, he did so with Suzy Bogguss.
He returned to his country roots for albums he recorded with Mark Knopfler and Jerry Reed. Knopfler had long mentioned Atkins as one of his earliest influences. Atkins also collaborated with Australian guitar legend Tommy Emmanuel. On being asked to name the ten most influential guitarists of the twentieth century, he named Django Reinhardt to the first position, and also placed himself on the list.
In later years, he even went back to radio, appearing on Garrison Keillor's "Prairie Home Companion" radio program, on American Public Media radio, even picking up a fiddle from time to time, and performing songs such as Bob Wills's "Corrina, Corrina" and Willie Nelson's "Seven Spanish Angels" with Nelson on a 1985 broadcast of the show at the Bridges Auditorium on the campus of Pomona College.
Atkins received numerous awards, including 14 Grammy awards and nine Country Music Association awards for Instrumentalist of the Year. In 1993, he was honored with the Grammy Lifetime Achievement Award. "Billboard" magazine awarded him its Century Award, its "highest honor for distinguished creative achievement," in December 1997.
Atkins is notable for his broad influence. His love for numerous styles of music can be traced from his early recording of the stride pianist James P. Johnson's "Johnson Rag", all the way to the rock stylings of Eric Johnson, an invited guest on Atkins's recording sessions, who, when Atkins attempted to copy his influential rocker "Cliffs of Dover", led to Atkins's creation of a unique arrangement of "Londonderry Air (Danny Boy)".
The classical guitar selections included on almost all his albums were, for many American artists working in the field today, the first classical guitar they ever heard. He recorded smooth jazz guitar still played on American airwaves today.
Atkins continued performing in the 1990s, but his health declined after he was diagnosed again with colon cancer in 1996. He died on June 30, 2001, at his home in Nashville, Tennessee, at the age of 77. His memorial service was held at Ryman Auditorium in Nashville. He was buried at Harpeth Hills Memory Gardens in Nashville.
A stretch of Interstate 185 in southwest Georgia (between LaGrange and Columbus) is named "Chet Atkins Parkway". This stretch of interstate runs through Fortson, where Atkins spent much of his childhood.
In 2002, Atkins was posthumously inducted into the Rock and Roll Hall of Fame. His award was presented by Marty Stuart and Brian Setzer and accepted by Atkins's grandson, Jonathan Russell. The following year, Atkins ranked number 28 in Country Music Television's "40 Greatest Men of Country Music".
At the age of 13, the future jazz guitarist Earl Klugh was captivated watching Atkins's guitar playing on "The Perry Como Show." Similarly, he was a big influence on Doyle Dykes. Atkins also inspired Drexl Jonez and Tommy Emmanuel.
Clint Black's album "Nothin' but the Taillights" includes the song "Ode to Chet", which includes the lyrics "'Cause I can win her over like Romeo did Juliet, if I can only show her I can almost pick that legato lick like Chet" and "It'll take more than Mel Bay 1, 2, & 3 if I'm ever gonna play like CGP." Atkins played guitar on the track. At the end of the song, Black and Atkins had a brief conversation.
Chet's song "Jam Man" is currently used in commercials for Esurance.
The opening guitar licks to the Miranda Lambert song "Only Prettier" sound very similar to Atkins's guitar-picking style.
In 1967, a tribute song, "Chet's Tune", was produced for his birthday, with contributions by a long list of RCA Victor artists, including Eddy Arnold, Connie Smith, Jerry Reed, Willie Nelson, Hank Snow, and others. The song was written by the Nashville songwriter Cy Coben, a friend of Atkins's. The single reached number 38 on the country charts.
In 2009, Steve Wariner released an album titled "My Tribute to Chet Atkins". One song from that record, "Producer's Medley", featured Wariner's recreation of several famous songs that Atkins both produced and performed. "Producer's Medley" won the Grammy for Best Country Instrumental Performance in 2010.
In November 2011, "Rolling Stone" ranked Atkins number 21 on their list of the "100 Greatest Guitarists of All Time".
Country Music Association
Country Music Hall of Fame and Museum
Grammy Awards
Rock and Roll Hall of Fame | https://en.wikipedia.org/wiki?curid=7756 |
Circuit Zandvoort
Circuit Zandvoort (; known as Circuit Park Zandvoort until 2017) is a motorsport race track located in the dunes north of Zandvoort, Netherlands, near the North Sea coast line. It will return to the Formula One calendar in 2021 as the location of the revived Dutch Grand Prix.
There were plans for races at Zandvoort before World War II: the first street race was held on 3 June 1939. However, a permanent race track was not constructed until after the war, using communications roads built by the occupying German army. Contrary to popular belief John Hugenholtz cannot be credited with the design of the Zandvoort track, although he was involved as the chairman of the Nederlandse Automobiel Ren Club (Dutch Auto Racing Club) before becoming the first track director in 1949. Instead, it was 1927 Le Mans winner, S. C. H. "Sammy" Davis who was brought in as a track design advisor in July 1946 although the layout was partly dictated by the existing roads.
The first race on the circuit, the "Prijs van Zandvoort", took place on 7 August 1948. The race was renamed the "Grote Prijs van Zandvoort" (Zandvoort Grand Prix) in 1949, then the "Grote Prijs van Nederland" (Dutch Grand Prix) in 1950. The 1952 race was the first to be run as a round of the World Drivers' Championship, albeit to Formula Two regulations rather than Formula One regulations like all the European rounds of the Championship that year; a similar situation also applied to the 1953. There was no Dutch Grand Prix in 1954, 1956 or 1957, but 1955 saw the first true Formula One race as part of the Drivers' Championship. The Dutch Grand Prix returned in 1958 and remained a permanent fixture on the F1 calendar (with the exception of 1972) until , when it was held for the last time.
To solve a number of problems that had made it impossible to develop and upgrade the track, the most important one being noise pollution for the inhabitants of the part of Zandvoort closest to the track, the track management adopted and developed a plan to move the most southern part of the track away from the housing estate and rebuild a more compact track in the remaining former 'infield'. In January 1987 this plan got the necessary 'green light' when it was formally approved by the Noord-Holland Provincial Council. However, only a couple of months later a new problem arose: the company that commercially ran the circuit (CENAV), called in the receiver and went out of business, marking the end of "Circuit van Zandvoort".
Again the track, owned by the municipality of Zandvoort, was in danger of being permanently lost for motorsports. However, a new operating company, the Stichting Exploitatie Circuit Park, was formed and started work at the realization of the track's reconstruction plans. Circuit Park Zandvoort was born and in the summer of 1989 the track was remodeled to an interim Club Circuit of , while the disposed southern part of the track was used to build a Vendorado Bungalow Park and new premises for the local football and hockey clubs.
In 1995, CPZ ("Circuit Park Zandvoort") got the "A Status" of the Government of the Netherlands and began building an international Grand Prix Circuit. This project was finished in 2001 when, after the track was redesigned to a long circuit and a new pits building was realized (by HPG, the development company of John Hugenholtz jr, son of the former director), a new grandstand was situated along the long straight. One of the major events that is held at the circuit, along with DTM and A1GP, is the RTL Masters of Formula 3, where Formula Three cars of several national racing series compete with each other (originally called Marlboro Masters, before tobacco advertising ban). A noise restriction order was responsible for this event moving to the Belgian Circuit Zolder for 2007 and 2008. However, the race returned to its historical home in 2009.
Circuit Park Zandvoort played host to the first race in the 2006/07 season of A1 Grand Prix from 29 September–1 October 2006. On 21 August 2008, the official A1GP site reported that the 2008/09 season's first race has moved from the Mugello Circuit, Italy to Zandvoort on the 4–5 October 2008 due to the delay in the building the new chassis for the new race cars. The Dutch round moved to TT Circuit Assen in 2010. A1GP bankrupted before its fifth season and the Dutch round was replaced with Superleague Formula.
In November 2018 media brought the news that the Formula One racing organisation has invited the owners of the Zandvoort race track to make a concrete proposal to stage a Grand Prix race in 2020. In March 2019, it was confirmed that a letter of intent had been signed between Zandvoort and Formula One Management to stage the Dutch Grand Prix, but that it was dependent on private funding being secured to cover hosting the race. A deadline of March 31, 2019 was set for a final decision to be made. On 14 May 2019 it was confirmed that Zandvoort would host the Dutch Grand Prix for 2020 and beyond for a duration of at least three years, with the option to host another two in the future. The Municipality of Zandvoort will pay four million Euros which will be used so the circuit itself can undergo various changes, such as slight alterations to the track, to bring it up to date with F1 standards, this is set to include banking the final corner and Hugenholtzbocht. The infrastructure around the circuit is set to be improved as well, most of the money will be used to improve the accessibility to the track. On 29 August 2019, the 2020 Dutch Grand Prix at Zandvoort was placed 5th race on the draft schedule, listed on 3 May 2020, between China and Spain. On 17 September 2019, it was announced that Zandvoort would host the FIA Formula 2 Championship and FIA Formula 3 Championship, replacing the series' support races at Circuit Paul Ricard.
The circuit gained popularity because of its fast, sweeping corners such as Scheivlak as well as the "Tarzanbocht" (Tarzan corner) hairpin at the end of the start/finish straight. Tarzanbocht is the most famous corner in the circuit. Since there is a camber in the corner, it provides excellent overtaking opportunities. It is possible to pass around the outside as well as the easier inside lane. This corner is reportedly named after a local character who had earned the nickname of Tarzan and only wanted to give up his vegetable garden in the dunes if the track's designers named a nearby corner after him. On the other hand, many different stories about Tarzan Corner are known.
The circuit design has been modified and altered several times:
The corners are named as follows (the numbers correspond to the map in this section, starting at the start/finish line):
The elevation difference is .
In the history of the circuit, several fatal accidents have occurred.
In August 1959 the UCI Road World Championships men's race was held at Zandvoort. André Darrigade of France won the race, Tom Simpson (Britain) was 4th..
In 1994 a large interregional amateur race cycling race was organised by HSV De Kampioen in Haarlem. Since 2008, the course has been used as the venue for the Runner's World Zandvoort Circuit Run, a 5-kilometre road running competition. The 2010 edition of the race attracted Lornah Kiplagat, a multiple world champion, who won the ladies 5 km race.
The Cycling Zandvoort 24h race was first held on 25–26 May 2013. It is open for public for soloists and teams up to 8 riders. A 6-hours was added to the event in 2016. On 13./14. June 2015 (12:00) the Cycling Zandvoort – 24 hour race over 4307-m-laps took place. | https://en.wikipedia.org/wiki?curid=7767 |
Christmas tree
A Christmas tree is a decorated tree, usually an evergreen conifer, such as a spruce, pine or fir, or an artificial tree of similar appearance, associated with the celebration of Christmas, originating in Northern Europe. The custom was developed in medieval Livonia (present-day Estonia and Latvia), and in early modern Germany where Protestant Germans brought decorated trees into their homes. It acquired popularity beyond the Lutheran areas of Germany and the Baltic countries during the second half of the 19th century, at first among the upper classes. The Catholic Church had long resisted this Protestant custom and the Christmas Tree stood for the first time in Vatican in 1982.
The tree was traditionally decorated with "roses made of colored paper, apples, wafers, tinsel, [and] sweetmeats". In the 18th century, it began to be illuminated by candles, which were ultimately replaced by Christmas lights after the advent of electrification. Today, there is a wide variety of traditional and modern ornaments, such as garlands, baubles, tinsel, and candy canes. An angel or star might be placed at the top of the tree to represent the Angel Gabriel or the Star of Bethlehem, respectively, from the Nativity. Edible items such as gingerbread, chocolate and other sweets are also popular and are tied to or hung from the tree's branches with ribbons.
In the Western Christian tradition, Christmas trees are variously erected on days such as the first day of Advent or even as late as Christmas Eve depending on the country; customs of the same faith hold that the two traditional days when Christmas decorations, such as the Christmas tree, are removed are Twelfth Night and, if they are not taken down on that day, Candlemas, the latter of which ends the Christmas-Epiphany season in some denominations.
The Christmas tree is sometimes compared with the "Yule-tree", especially in discussions of its folkloric origins.
Modern Christmas trees originated during the Renaissance in early modern Germany. Its 16th-century origins are sometimes associated with Protestant Christian reformer Martin Luther, who is said to have first added lighted candles to an evergreen tree.
The earliest known firmly dated representation of a Christmas tree is on the keystone sculpture of a private home in Turckheim, Alsace (then part of Germany, today France), with the date 1576.
Modern Christmas trees have been related to the "tree of paradise" of medieval mystery plays that were given on 24 December, the commemoration and name day of Adam and Eve in various countries. In such plays, a tree decorated with apples (to represent the forbidden fruit) and wafers (to represent the Eucharist and redemption) was used as a setting for the play. Like the Christmas crib, the Paradise tree was later placed in homes. The apples were replaced by round objects such as shiny red balls.
At the end of the Middle Ages, an early predecessor appears referred in the Regiment of the Order of Cister in the 15th century, in Alcobaça, Portugal. The Regiment of the local "high-Sacristans" of the Cistercian Order refers to what may be considered the oldest references to the Christmas tree: "Note on how to put the Christmas branch, "scilicet": On the Christmas eve, you will look for a large Branch of green laurel, and you shall reap many red oranges, and place them on the branches that come of the laurel, specifically as you have seen, and in every orange you shall put a candle, and hang the Branch by a rope in the pole, which shall be by the candle of the "altar-mor"."
The relevance of ancient pre-Christian customs to the 16th-century German initiation of the Christmas tree custom is disputed. Resistance to the custom was often because of its supposed Lutheran origins.
Other sources have offered a connection between the symbolism of the first documented Christmas trees in Alsace around 1600 and the trees of pre-Christian traditions. For example, according to the "Encyclopædia Britannica", "The use of evergreen trees, wreaths, and garlands to symbolize eternal life was a custom of the ancient Egyptians, Chinese, and Hebrews. Tree worship was common among the pagan Europeans and survived their conversion to Christianity in the Scandinavian customs of decorating the house and barn with evergreens at the New Year to scare away the devil and of setting up a tree for the birds during Christmas time."
During the Roman mid-winter festival of Saturnalia, houses were decorated with wreaths of evergreen plants, along with other antecedent customs now associated with Christmas.
The Vikings and Saxons worshiped trees. The story of Saint Boniface cutting down Donar's Oak illustrates the pagan practices in 8th century among the Germans. A later folk version of the story adds the detail that an evergreen tree grew in place of the felled oak, telling them about how its triangular shape reminds humanity of the Trinity and how it points to heaven.
Georgians have their own traditional Christmas tree called Chichilaki, made from dried up hazelnut or walnut branches that are shaped to form a small coniferous tree. These pale-colored ornaments differ in height from to . Chichilakis are most common in the Guria and Samegrelo regions of Georgia near the Black Sea, but they can also be found in some stores around the capital of Tbilisi.
Georgians believe that Chichilaki resembles the famous beard of St. Basil the Great, because Eastern Orthodox Church commemorates St. Basil on 1January.
In Poland, there is a folk tradition dating back to an old Slavic pagan custom of suspending a branch of fir, spruce or pine from the ceiling, called "", during the time of the Koliada winter festival. The branches were decorated with apples, nuts, acorns and stars made of straw. In more recent times, the decorations also included colored paper cutouts ("wycinanki"), wafers, cookies and Christmas baubles. According to old pagan beliefs, the branch's powers were linked to good harvest and prosperity.
The custom lasted among some of the rural peasants into the early 20th century, particularly in the regions of Lesser Poland and Upper Silesia. Most often the branches were hung above the "wigilia" dinner table on Christmas Eve from the rafters. Beginning in the mid-19th century, the tradition over time was almost completely replaced by the German practice of decorating a Christmas tree. The custom was partly revived in the 1970s and continues to the present.
Customs of erecting decorated trees in wintertime can be traced to Christmas celebrations in Renaissance-era guilds in Northern Germany and Livonia. The first evidence of decorated trees associated with Christmas Day are trees in guildhalls decorated with sweets to be enjoyed by the apprentices and children. In Livonia (present-day Estonia and Latvia), in 1441, 1442, 1510 and 1514, the Brotherhood of Blackheads erected a tree for the holidays in their guild houses in Reval (now Tallinn) and Riga. On the last night of the celebrations leading up to the holidays, the tree was taken to the Town Hall Square, where the members of the brotherhood danced around it.
A Bremen guild chronicle of 1570 reports that a small tree decorated with "apples, nuts, dates, pretzels and paper flowers" was erected in the guild-house for the benefit of the guild members' children, who collected the dainties on Christmas Day. In 1584, the pastor and chronicler Balthasar Russow in his (1584) wrote of an established tradition of setting up a decorated spruce at the market square, where the young men "went with a flock of maidens and women, first sang and danced there and then set the tree aflame".
After the Protestant Reformation, such trees are seen in the houses of upper-class Protestant families as a counterpart to the Catholic Christmas cribs. This transition from the guild hall to the bourgeois family homes in the Protestant parts of Germany ultimately gives rise to the modern tradition as it developed in the 18th and 19th centuries.
By the early 18th century, the custom had become common in towns of the upper Rhineland, but it had not yet spread to rural areas. Wax candles, expensive items at the time, are found in attestations from the late 18th century.
Along the lower Rhine, an area of Roman Catholic majority, the Christmas tree was largely regarded as a Protestant custom. As a result, it remained confined to the upper Rhineland for a relatively long period of time. The custom did eventually gain wider acceptance beginning around 1815 by way of Prussian officials who emigrated there following the Congress of Vienna.
In the 19th century, the Christmas tree was taken to be an expression of German culture and of , especially among emigrants overseas.
A decisive factor in winning general popularity was the German army's decision to place Christmas trees in its barracks and military hospitals during the Franco-Prussian War. Only at the start of the 20th century did Christmas trees appear inside churches, this time in a new brightly lit form.
In the early 19th century, the custom became popular among the nobility and spread to royal courts as far as Russia. Princess Henrietta of Nassau-Weilburg introduced the Christmas tree to Vienna in 1816, and the custom spread across Austria in the following years. In France, the first Christmas tree was introduced in 1840 by the duchesse d'Orléans. In Denmark a Danish newspaper claims that the first attested Christmas tree was lit in 1808 by countess Wilhemine of Holsteinborg. It was the aging countess who told the story of the first Danish Christmas tree to the Danish writer Hans Christian Andersen in 1865. He had published a fairy tale called "The Fir-Tree" in 1844, recounting the fate of a fir tree being used as a Christmas tree.
Although the tradition of decorating churches and homes with evergreens at Christmas was long established, the custom of decorating an entire small tree was unknown in Britain until some two centuries ago. At the time of the personal union with Hanover, George III's German-born wife, Charlotte of Mecklenburg-Strelitz, introduced a Christmas tree at a party she gave for children in 1800. The custom did not at first spread much beyond the royal family. Queen Victoria as a child was familiar with it and a tree was placed in her room every Christmas. In her journal for Christmas Eve 1832, the delighted 13-year-old princess wrote:
After dinner... we then went into the drawing room near the dining room... There were two large round tables on which were placed two trees hung with lights and sugar ornaments. All the presents being placed round the trees...
After Victoria's marriage to her German cousin Prince Albert, by 1841 the custom became even more widespread as wealthier middle-class families followed the fashion. In 1842 a newspaper advert for Christmas trees makes clear their smart cachet, German origins and association with children and gift-giving. An illustrated book, "The Christmas Tree", describing their use and origins in detail, was on sale in December 1844. On 2January 1846 Elizabeth Fielding (née Fox Strangways) wrote from Laycock Abbey to William Henry Fox-Talbot: ""Constance is extremely busy preparing the Bohemian Xmas Tree. It is made from Caroline's description of those she saw in Germany"". In 1847 Prince Albert wrote: "I must now seek in the children an echo of what Ernest [his brother] and I were in the old time, of what we felt and thought; and their delight in the Christmas trees is not less than ours used to be". A boost to the trend was given in 1848 when "The Illustrated London News", in a report picked up by other papers, described the trees in Windsor Castle in detail and showed the main tree, surrounded by the royal family, on its cover. In fewer than ten years their use in better-off homes was widespread. By 1856 a northern provincial newspaper contained an advert alluding casually to them, as well as reporting the accidental death of a woman whose dress caught fire as she lit the tapers on a Christmas tree. They had not yet spread down the social scale though, as a report from Berlin in 1858 contrasts the situation there where "Every family has its own" with that of Britain, where Christmas trees were still the preserve of the wealthy or the "romantic".
Their use at public entertainments, charity bazaars and in hospitals made them increasingly familiar however, and in 1906 a charity was set up specifically to ensure even poor children in London slums "who had never seen a Christmas tree" would enjoy one that year. Anti-German sentiment after World WarI briefly reduced their popularity but the effect was short-lived, and by the mid-1920s the use of Christmas trees had spread to all classes. In 1933 a restriction on the importation of foreign trees led to the "rapid growth of a new industry" as the growing of Christmas trees within Britain became commercially viable due to the size of demand. By 2013 the number of trees grown in Britain for the Christmas market was approximately eight million and their display in homes, shops and public spaces a normal part of the Christmas season.
The tradition was introduced to North America in the winter of 1781 by Hessian soldiers stationed in the Province of Québec (1763–1791) to garrison the colony against American attack. General Friedrich Adolf Riedesel and his wife, the Baroness von Riedesel, held a Christmas party for the officers at Sorel, Quebec, delighting their guests with a fir tree decorated with candles and fruits.
The Christmas tree became very common in the United States in the early nineteenth century. The first image of a Christmas tree was published in 1836 as the frontispiece to "The Stranger's Gift" by Hermann Bokum. The first mention of the Christmas tree in American literature was in a story in the 1836 edition of "The Token and Atlantic Souvenir", titled "New Year's Day", by Catherine Maria Sedgwick, where she tells the story of a German maid decorating her mistress's tree. Also, a woodcut of the British Royal family with their Christmas tree at Windsor Castle, initially published in "The Illustrated London News" December 1848, was copied in the United States at Christmas 1850, in "Godey's Lady's Book". "Godey's" copied it exactly, except for the removal of the Queen's tiara and Prince Albert's moustache, to remake the engraving into an American scene. The republished "Godey's" image became the first widely circulated picture of a decorated evergreen Christmas tree in America. Art historian Karal Ann Marling called Prince Albert and Queen Victoria, shorn of their royal trappings, "the first influential American Christmas tree". Folk-culture historian Alfred Lewis Shoemaker states, "In all of America there was no more important medium in spreading the Christmas tree in the decade 1850–60 than "Godey's Lady's Book"". The image was reprinted in 1860, and by the 1870s, putting up a Christmas tree had become even more common in America.
Several cities in the United States with German connections lay claim to that country's first Christmas tree: Windsor Locks, Connecticut, claims that a Hessian soldier put up a Christmas tree in 1777 while imprisoned at the Noden-Reed House, while the "First Christmas Tree in America" is also claimed by Easton, Pennsylvania, where German settlers purportedly erected a Christmas tree in 1816. In his diary, Matthew Zahm of Lancaster, Pennsylvania, recorded the use of a Christmas tree in 1821, leading Lancaster to also lay claim to the first Christmas tree in America. Other accounts credit Charles Follen, a German immigrant to Boston, for being the first to introduce to America the custom of decorating a Christmas tree. August Imgard, a German immigrant living in Wooster, Ohio, is said to be the first to popularize the practice of decorating a tree with candy canes. In 1847, Imgard cut a blue spruce tree from a woods outside town, had the Wooster village tinsmith construct a star, and placed the tree in his house, decorating it with paper ornaments, gilded nuts and Kuchen. German immigrant Charles Minnigerode accepted a position as a professor of humanities at the College of William & Mary in Williamsburg, Virginia, in 1842, where he taught Latin and Greek. Entering into the social life of the Virginia Tidewater, Minnigerode introduced the German custom of decorating an evergreen tree at Christmas at the home of law professor St. George Tucker, thereby becoming another of many influences that prompted Americans to adopt the practice at about that time. An 1853 article on Christmas customs in Pennsylvania defines them as mostly "German in origin", including the Christmas tree, which is "planted in a flower pot filled with earth, and its branches are covered with presents, chiefly of confectionary, for the younger members of the family." The article distinguishes between customs in different states however, claiming that in New England generally "Christmas is not much celebrated", whereas in Pennsylvania and New York it is.
When Edward H. Johnson was vice president of the Edison Electric Light Company, a predecessor of Con Edison, he created the first known electrically illuminated Christmas tree at his home in New York City in 1882. Johnson became the "Father of Electric Christmas Tree Lights".
The lyrics sung in the United States to the German tune begin "OChristmas tree...", giving rise to the mistaken idea that the German word (fir tree) means "Christmas tree", the German word for which is instead .
In Russia, the Christmas tree was banned after the October Revolution but then reinstated as a "New-year spruce" (, ) in 1935. It became a fully secular icon of the New Year holiday, for example, the crowning star was regarded not as a symbol of Bethlehem Star, but as the Red star. Decorations, such as figurines of airplanes, bicycles, space rockets, cosmonauts, and characters of Russian fairy tales, were produced. This tradition persists after the fall of the USSR, with the New Year holiday outweighing the Christmas (7 January) for a wide majority of Russian people.
The TV special "A Charlie Brown Christmas" (1965) was influential on the pop culture surrounding the Christmas tree. Aluminum Christmas trees were popular during the early 1960s in the US. They were satirized in the Charlie Brown show and came to be seen as symbolizing the commercialization of Christmas. The term "Charlie Brown Christmas tree", describing any poor-looking or malformed little tree, also derives from the 1965 TV special, based on the appearance of Charlie Brown's Christmas tree.
Since the early 20th century, it has become common in many cities, towns, and department stores to put up public Christmas trees outdoors, such as the Macy's Great Tree in Atlanta (since 1948), the Rockefeller Center Christmas Tree in New York City, and the large Christmas tree at Victoria Square in Adelaide.
The use of fire retardant allows many indoor public areas to place real trees and be compliant with code. Licensed applicants of fire retardant solution spray the tree, tag the tree, and provide a certificate for inspection. Real trees are popular with high end visual merchandising displays around the world. Leading global retailers such as Apple often place real trees in their window displays. In 2009, Apple placed two Fraser fir trees in every one of its retail establishments.
The United States' National Christmas Tree has been lit each year since 1923 on the South Lawn of the White House, becoming part of what evolved into a major holiday event at the White House. President Jimmy Carter lit only the crowning star atop the tree in 1979 in honor of the Americans being held hostage in Iran. The same was true in 1980, except the tree was fully lit for 417 seconds, one second for each day the hostages had been in captivity.
During most of the 1970s and 1980s, the largest decorated Christmas tree in the world was put up every year on the property of the "National Enquirer" in Lantana, Florida. This tradition grew into one of the most spectacular and celebrated events in the history of southern Florida, but was discontinued on the death of the paper's founder in the late 1980s.
In some cities, a charity event called the Festival of Trees is organized, in which multiple trees are decorated and displayed.
The giving of Christmas trees has also often been associated with the end of hostilities. After the signing of the Armistice in 1918 the city of Manchester sent a tree, and £500 to buy chocolate and cakes, for the children of the much-bombarded town of Lille in northern France. In some cases the trees represent special commemorative gifts, such as in Trafalgar Square in London, where the City of Oslo, Norway presents a tree to the people of London as a token of appreciation for the British support of Norwegian resistance during the Second World War; in Boston, where the tree is a gift from the province of Nova Scotia, in thanks for rapid deployment of supplies and rescuers to the 1917 ammunition ship explosion that leveled the city of Halifax; and in Newcastle upon Tyne, where the main civic Christmas tree is an annual gift from the city of Bergen, in thanks for the part played by soldiers from Newcastle in liberating Bergen from Nazi occupation. Norway also annually gifts a Christmas tree to Washington, D.C. as a symbol of friendship between Norway and the US and as an expression of gratitude from Norway for the help received from the US during World War II.
A "Chrismon tree" is a Christmas tree decorated with explicitly Christian symbols in white and gold.
First introduced by North American Lutherans in 1957, the practice has rapidly spread to other Christian denominations, including Anglicans,
Catholics, Methodists, and the Reformed.
"Chrismon" (plural "Chrismons") was adopted for the type of Christmas decoration and explained as a portmanteau of "Christ-monogram" (a Christogram).
Both setting up and taking down a Christmas tree are associated with specific dates. Traditionally, Christmas trees were not brought in and decorated until Christmas Eve (24 December) or, in the traditions celebrating Christmas Eve rather than the first day of Christmas, 23 December, and then removed the day after Twelfth Night (5 January); to have a tree up before or after these dates was even considered bad luck, and that to avoid bad luck from affecting the house's residents, the tree must be left up until after the following Twelfth Night passes.
In many areas, it has become customary to set up one's Christmas tree at the beginning of the Advent season. Americans will put up a Christmas tree after Thanksgiving (the fourth Thursday of November), and Christmas decorations can show up even earlier in retail stores, often the day after Halloween (31 October). In Canada many stores wait until after Remembrance Day, as to show respect to fallen soldiers. Some households do not put up the tree until the second week of December, and leave it up until 6January (Epiphany). In Germany, traditionally the tree is put up on 24 December and taken down on 7January, though many start one or two weeks earlier, and in Roman Catholic homes the tree may be kept until 2February (Candlemas).
In Italy, Ireland and Argentina, along with many countries in Latin America, the Christmas tree is put up on 8December (Immaculate Conception day) and left up until 6January. In Australia, the Christmas tree is usually put up on 1December, which occurs about two weeks before the school summer holidays (except for South Australia, where most people put up their tree in November following the completion of the Adelaide Christmas Pageant, a time frame that has started to filter into other states as the official time Christmas decorations and in store Santa Claus start to appear) and is left up until it is taken down. Some traditions suggest that Christmas trees may be kept up until no later than 2February, the feast of the Presentation of Jesus at the Temple (Candlemas), when the Christmas season effectively closes. Superstitions say that it is a bad sign if Christmas greenery is not removed by Candlemas Eve.
Christmas ornaments are decorations (usually made of glass, metal, wood, or ceramics) that are used to decorate a Christmas tree. The first decorated trees were adorned with apples, white candy canes and pastries in the shapes of stars, hearts and flowers. Glass baubles were first made in Lauscha, Germany, and also garlands of glass beads and tin figures that could be hung on trees. The popularity of these decorations grew into the production of glass figures made by highly skilled artisans with clay molds.
Tinsel and several types of garland or ribbon are commonly used to decorate a Christmas tree. Silvered saran-based tinsel was introduced later. Delicate mold-blown and painted colored glass Christmas ornaments were a specialty of the glass factories in the Thuringian Forest, especially in Lauscha in the late 19th century, and have since become a large industry, complete with famous-name designers. Baubles are another common decoration, consisting of small hollow glass or plastic spheres coated with a thin metallic layer to make them reflective, with a further coating of a thin pigmented polymer in order to provide coloration.
Lighting with electric lights (Christmas lights or, in the United Kingdom, fairy lights) is commonly done. A tree-topper, sometimes an angel but more frequently a star, completes the decoration.
In the late 1800s, home-made white Christmas trees were made by wrapping strips of cotton batting around leafless branches creating the appearance of a snow-laden tree.
In the 1940s and 1950s, popularized by Hollywood films in the late 1930s, flocking was very popular on the West Coast of the United States. There were home flocking kits that could be used with vacuum cleaners. In the 1980s some trees were sprayed with fluffy white flocking to simulate snow.
Each year, 33 to 36 million Christmas trees are produced in America, and 50 to 60 million are produced in Europe. In 1998, there were about 15,000 growers in America (a third of them "choose and cut" farms). In that same year, it was estimated that Americans spent $1.5billion on Christmas trees. By 2016 that had climbed to $2.04billion for natural trees and a further $1.86billion for artificial trees. In Europe, 75 million trees worth €2.4billion ($3.2 billion) are harvested annually.
The average cost of a live cut tree in the United States was $64 in 2015 and this rose to $73 in 2017. The price is expected to hold steady for the next year.
The most commonly used species are fir ("Abies"), which have the benefit of not shedding their needles when they dry out, as well as retaining good foliage color and scent; but species in other genera are also used.
In northern Europe most commonly used are:
In North America, Central America, South America and Australia most commonly used are:
Several other species are used to a lesser extent. Less-traditional conifers are sometimes used, such as giant sequoia, Leyland cypress, Monterey cypress and eastern juniper. Various types of spruce tree are also used for Christmas trees (including the blue spruce and, less commonly, the white spruce); but spruces begin to lose their needles rapidly upon being cut, and spruce needles are often sharp, making decorating uncomfortable. Virginia pine is still available on some tree farms in the southeastern United States; however, its winter color is faded. The long-needled eastern white pine is also used there, though it is an unpopular Christmas tree in most parts of the country, owing also to its faded winter coloration and limp branches, making decorating difficult with all but the lightest ornaments. Norfolk Island pine is sometimes used, particularly in Oceania, and in Australia, some species of the genera "Casuarina" and "Allocasuarina" are also occasionally used as Christmas trees. But, by far, the most common tree is the Pinus radiata Monterey pine. "Adenanthos sericeus" or Albany woolly bush is commonly sold in southern Australia as a potted living Christmas tree. Hemlock species are generally considered unsuitable as Christmas trees due to their poor needle retention and inability to support the weight of lights and ornaments.
Some trees, frequently referred to as "living Christmas trees", are sold live with roots and soil, often from a plant nursery, to be stored at nurseries in planters or planted later outdoors and enjoyed (and often decorated) for years or decades. Others are produced in a container and sometimes as topiary for a porch or patio. However, when done improperly, the combination of root loss caused by digging, and the indoor environment of high temperature and low humidity is very detrimental to the tree's health; additionally, the warmth of an indoor climate will bring the tree out of its natural winter dormancy, leaving it little protection when put back outside into a cold outdoor climate. Often Christmas trees are a large attraction for living animals, including mice and spiders. Thus, the survival rate of these trees is low. However, when done properly, replanting provides higher survival rates.
European tradition prefers the open aspect of naturally grown, unsheared trees, while in North America (outside western areas where trees are often wild-harvested on public lands) there is a preference for close-sheared trees with denser foliage, but less space to hang decorations.
In the past, Christmas trees were often harvested from wild forests, but now almost all are commercially grown on tree farms. Almost all Christmas trees in the United States are grown on Christmas tree farms where they are cut after about ten years of growth and new trees planted. According to the United States Department of Agriculture's agriculture census for 2007, 21,537 farms were producing conifers for the cut Christmas tree market in America, were planted in Christmas trees.
The life cycle of a Christmas tree from the seed to a tree takes, depending on species and treatment in cultivation, between eight and twelve years. First, the seed is extracted from cones harvested from older trees. These seeds are then usually grown in nurseries and then sold to Christmas tree farms at an age of three to four years. The remaining development of the tree greatly depends on the climate, soil quality, as well as the cultivation and how the trees are tended by the Christmas tree farmer.
The first artificial Christmas trees were developed in Germany during the 19th century, though earlier examples exist. These "trees" were made using goose feathers that were dyed green, as one response by Germans to continued deforestation. Feather Christmas trees ranged widely in size, from a small tree to a large tree sold in department stores during the 1920s. Often, the tree branches were tipped with artificial red berries which acted as candle holders.
Over the years, other styles of artificial Christmas trees have evolved and become popular. In 1930, the U.S.-based Addis Brush Company created the first artificial Christmas tree made from brush bristles. Another type of artificial tree is the aluminum Christmas tree, first manufactured in Chicago in 1958, and later in Manitowoc, Wisconsin, where the majority of the trees were produced. Most modern artificial Christmas trees are made from plastic recycled from used packaging materials, such as polyvinyl chloride (PVC). Approximately 10% of artificial Christmas trees are using virgin suspension PVC resin; despite being plastic most artificial trees are not recyclable or biodegradable.
Other trends have developed in the early 2000s as well. Optical fiber Christmas trees come in two major varieties; one resembles a traditional Christmas tree. One Dallas-based company offers "holographic mylar" trees in many hues. Tree-shaped objects made from such materials as cardboard, glass, ceramic or other materials can be found in use as tabletop decorations. Upside-down artificial Christmas trees became popular for a short time and were originally introduced as a marketing gimmick; they allowed consumers to get closer to ornaments for sale in retail stores and opened up floor space for more products.
Artificial trees became increasingly popular during the late 20th century. Users of artificial Christmas trees assert that they are more convenient, and, because they are reusable, much cheaper than their natural alternative. They are also considered much safer as natural trees can be a significant fire hazard. Between 2001 and 2007 artificial Christmas tree sales in the U.S. jumped from 7.3 million to 17.4 million. Currently it is estimated that around 58% of Christmas trees used in the United States are artificial while numbers in the United Kingdom are indicated to be around 66%.
The debate about the environmental impact of artificial trees is ongoing. Generally, natural tree growers contend that artificial trees are more environmentally harmful than their natural counterparts. However, trade groups such as the American Christmas Tree Association, continue to refute that artificial trees are more harmful to the environment, and maintain that the PVC used in Christmas trees has excellent recyclable properties.
Live trees are typically grown as a crop and replanted in rotation after cutting, often providing suitable habitat for wildlife. Alternately, live trees can be donated to livestock farmers who find that such trees uncontaminated by chemical additives are excellent fodder. In some cases management of Christmas tree crops can result in poor habitat since it sometimes involves heavy input of pesticides.
Concerns have been raised about people cutting down old and rare conifers, such as the "Keteleeria evelyniana" and "Abies fraseri", for Christmas trees.
Real or cut trees are used only for a short time, but can be recycled and used as mulch, wildlife habitat, or used to prevent erosion. Real trees are carbon-neutral, they emit no more carbon dioxide by being cut down and disposed of than they absorb while growing. However, emissions can occur from farming activities and transportation. An independent life-cycle assessment study, conducted by a firm of experts in sustainable development, states that a natural tree will generate of greenhouse gases every year (based on purchasing from home) whereas the artificial tree will produce over its lifetime. Some people use living Christmas or potted trees for several seasons, providing a longer life cycle for each tree. Living Christmas trees can be purchased or rented from local market growers. Rentals are picked up after the holidays, while purchased trees can be planted by the owner after use or donated to local tree adoption or urban reforestation services. Smaller and younger trees may be replanted after each season, with the following year running up to the next Christmas allowing the tree to carry out further growth.
Most artificial trees are made of recycled PVC rigid sheets using tin stabilizer in the recent years. In the past, lead was often used as a stabilizer in PVC, but is now banned by Chinese laws.
The use of lead stabilizer in Chinese imported trees has been an issue of concern among politicians and scientists over recent years. A 2004 study found that while in general artificial trees pose little health risk from lead contamination, there do exist "worst-case scenarios" where major health risks to young children exist. A 2008 United States Environmental Protection Agency report found that as the PVC in artificial Christmas trees aged it began to degrade. The report determined that of the fifty million artificial trees in the United States approximately twenty million were nine or more years old, the point where dangerous lead contamination levels are reached. A professional study on the life-cycle assessment of both real and artificial Christmas trees revealed that one must use an artificial Christmas tree at least twenty years to leave an environmental footprint as small as the natural Christmas tree.
The earliest legend of the origin of the Christmas tree dates back to 723, involving Saint Boniface as he was evangelizing Germany. According to a story not mentioned in his biographies ("vitae"), he stumbled upon a pagan gathering where a group of people dancing under a decorated oak tree were about to sacrifice a baby in the name of Thor. Boniface took an axe and called on the name of Jesus. In one swipe, he managed to take down the entire tree, to the crowd's astonishment. Behind the fallen tree was a baby fir. Boniface said, "let this tree be the symbol of the true God, its leaves are ever green and will not die." The tree's needles pointed to heaven. Tradition holds that trees were used in formerly pagan homes from that moment forth, but decorated in the name of Jesus.
The Christmas tree was first recorded to be used by German Lutherans in the 16th century, with records indicating that a Christmas tree was placed in the Cathedral of Strasbourg in 1539, under the leadership of the Protestant Reformer, Martin Bucer. In the United States, these "German Lutherans brought the decorated Christmas tree with them; the Moravians put lighted candles on those trees." When decorating the Christmas tree, many individuals place a star at the top of the tree symbolizing the Star of Bethlehem, a fact recorded by "The School Journal" in 1897. Professor David Albert Jones of the University of Oxford writes that in the 19th century, it became popular for people to also use an angel to top the Christmas tree in order to symbolize the angels mentioned in the accounts of the Nativity of Jesus.
Under the Marxist-Leninist doctrine of state atheism in the Soviet Union, after its foundation in 1917, Christmas celebrations—along with other religious holidays—were prohibited as a result of the Soviet anti-religious campaign. The League of Militant Atheists encouraged school pupils to campaign against Christmas traditions, among them being the Christmas tree, as well as other Christian holidays, including Easter; the League established an anti-religious holiday to be the 31st of each month as a replacement. With the Christmas tree being prohibited in accordance with Soviet anti-religious legislation, people supplanted the former Christmas custom with New Year's trees. In 1935 the tree was brought back as New Year tree and became a secular, not a religious holiday.
Pope John Paul II introduced the Christmas tree custom to the Vatican in 1982. Although at first disapproved of by some as out of place at the centre of the Roman Catholic Church, the Vatican Christmas Tree has become an integral part of the Vatican Christmas celebrations, and in 2005 Pope Benedict XVI spoke of it as part of the normal Christmas decorations in Catholic homes. In 2004, Pope John Paul called the Christmas tree a symbol of Christ. This very ancient custom, he said, exalts the value of life, as in winter what is evergreen becomes a sign of undying life, and it reminds Christians of the "tree of life" of , an image of Christ, the supreme gift of God to humanity. In the previous year he said: "Beside the crib, the Christmas tree, with its twinkling lights, reminds us that with the birth of Jesus the tree of life has blossomed anew in the desert of humanity. The crib and the tree: precious symbols, which hand down in time the true meaning of Christmas." The Catholic Church's official "Book of Blessings" has a service for the blessing of the Christmas tree in a home. The Episcopal Church in "The Anglican Family Prayer Book", which has the imprimatur of The Rt. Rev. Catherine S. Roskam of the Anglican Communion, has long had a ritual titled "Blessing of a Christmas Tree", as well as "Blessing of a Crèche", for use in the church and the home.
"Chrismon trees" are a variety developed in 1957 by a Lutheran laywoman in Virginia, as a specifically religious version appropriate for a church's Christmas celebrations, although most Christian churches continue to display the traditional Christmas tree in their sanctuaries during Christmastide.
In 2005, the city of Boston renamed the spruce tree used to decorate the Boston Common a "Holiday Tree" rather than a "Christmas Tree". The name change was reversed after the city was threatened with several lawsuits. | https://en.wikipedia.org/wiki?curid=7770 |
Carrier battle group
A carrier battle group (CVBG) is a naval fleet consisting of an aircraft carrier (designated CV) capital ship and its large number of escorts, together defining the group.
The first naval task forces built around carriers appeared just prior to and during Second World War. The Imperial Japanese Navy (IJN) was the first to assemble many carriers into a single task force, known as "Kido Butai". This task force was used with devastating effect in the Japanese attack on Pearl Harbor. Kido Butai operated as the IJN's main carrier battle group until four of its carriers were sunk at the Battle of Midway. In contrast, the United States Navy deployed its large carriers in separate formations, with each carrier assigned its own cruiser and destroyer escorts. These single-carrier formations would often be paired or grouped together for certain assignments, most notably the Battle of the Coral Sea and Midway. By 1943, however, large numbers of fleet and light carriers became available, which required larger formations of three or four carriers. These groups eventually formed the Fast Carrier Task Force, which became the primary battle unit of the U.S. Third and Fifth Fleets.
With the construction of the large "supercarriers" of the Cold War era, the practice of operating each carrier in a single formation was revived. During the Cold War, the main role of the CVBG in case of conflict with the Soviet Union would have been to protect Atlantic supply routes between the United States and its allies in NATO Europe, while the role of the Soviet Navy would have been to interrupt these sea lanes, a fundamentally easier task. Because the Soviet Union had no large carriers of its own, a situation of dueling aircraft carriers would have been unlikely. However, a primary mission of the Soviet Navy's attack submarines was to track every allied battle group and, on the outbreak of hostilities, sink the carriers. Understanding this threat, the CVBG expended enormous resources in its own anti-submarine warfare mission.
In the late 20th and early centuries, most uses of carrier battle groups by the United States as well as that of other Western nations have been in situations where their use has been uncontested by other comparable forces. During the Cold War, an important battle scenario was an attack against a CVBG using numerous antiship missiles.
British and French carrier battle groups were involved in the 1956 Suez Crisis.
During the Indo-Pakistani war of 1971, India used its carrier strike group centered on to impose a naval blockade upon East Pakistan. Air strikes were carried out initially on shipping in the Chittagong and Cox's Bazar harbors, sinking or incapacitating most ships there. Further strikes were carried out on Cox's Bazar from 60 nautical miles (110 km) offshore. On the evening of 4 December, the air group struck Chittagong Harbour. Later strikes targeted Khulna and the Port of Mongla. Air strikes continued until 10 December 1971.
The first attempted use of anti-ship missiles against a carrier battle group was part of Argentina's efforts against British Armed Forces during the Falklands War. This was the last conflict so far in which opposing belligerents employed aircraft carriers, although Argentina made little use of its sole carrier, originally built in the United Kingdom as HMS Venerable and later served with the Netherlands (1948-1968).
The United States Sixth Fleet assembled a force of three carrier battle groups and a battleship during the Lebanese Civil War in 1983. Daily reconnaissance flights were flown over the Bekaa Valley and a strike was flown against targets in the area resulting in loss of an A-6 Intruder and an A-7 Corsair.
Carrier battle groups routinely operated in the Gulf of Sidra inside the "Line of Death" proclaimed by Libya resulting in aerial engagements in 1981, 1986 and 1989 between U.S. Navy Tomcats and Libyan Su-22 aircraft, SA-5 surface-to-air missiles and MiG-23 fighters. During the 1986 clashes, three carrier battle groups deployed to the Gulf of Sidra and ultimately two of them conducted strikes against Libya in Operation El Dorado Canyon.
During the international military intervention in the 2011 Libyan civil war, the French Navy deployed its aircraft carrier, , off Libya. The "Charles de Gaulle" was accompanied by several frigates as , , , the replenishment tanker "Meuse" and two nuclear attack submarines.
In modern United States Navy carrier air operations, the moniker of carrier strike group (CSG) has replaced the traditional term of carrier battle group (CVBG or CARBATGRU). The US Navy maintains 11 carrier strike groups, 9 of which are based in the United States and one that is forward deployed in Yokosuka, Japan. CSG or CVBG normally consist of 1 aircraft carrier, 1 guided missile cruiser (for air defense), 2 LAMPS-capable warships (focusing on anti-submarine and surface warfare), and 1–2 anti-submarine destroyers or frigates. The large number of CSGs used by the United States reflects, in part, a division of roles and missions allotted during the Cold War, in which the United States assumed primary responsibility for blue-water operations and for safeguarding supply lines between the United States and Europe, while the NATO allies assumed responsibility for brown- and green-water operations.
An Expeditionary Strike Group is composed of an amphibious assault ship (LHA/LHD), a dock landing ship (LSD), an amphibious transport dock (LPD), a Marine expeditionary unit, AV-8B Harrier II or, more recently Lockheed Martin F-35B Lightning II aircraft, CH-53E Super Stallion and CH-46E Sea Knight helicopters or, more recently, MV-22B tiltrotors. Cruisers, destroyers and attack submarines are deployed with either an Expeditionary Strike Group or a Carrier Strike Group.
During the period when the American navy recommissioned all four of its s, it sometimes used a similar formation centered on a battleship, referred to as a battleship battle group (BBBG). It was alternately referred to as a Surface Action Group (SAG).
The battleship battle group typically consisted of one modernized battleship, one , one or , one , three s and one auxillary ship such as a replenishment oiler.
A Surface Action Group (SAG) is "a temporary or standing organization of combatant ships, other than carriers, tailored for a specific tactical mission".
China plans to set up several carrier battle groups in the future. At present China's only two aircraft carriers, the modified "Kuznetsov"-class "Liaoning" and "Shandong", use Type 052C or Type 052D destroyers for air defense, Type 054A frigates for anti-submarine and anti-ship warfare, 1–2 Type 093 nuclear attack submarines, and 1 Type 901 supply ship. China is currently building a third carrier, expected to be launched in 2020 and enter active service in 2023, as well as a nuclear-powered fourth carrier planned for construction and expected to be completed by the late 2020s. China is also building a new larger class of air defense destroyers, the Type 055.
The only serving French carrier is the , which also serves as the flagship of the Marine Nationale. The Carrier Battle Group (Groupe Aéronaval, GAN, in French) of the Force d'Action Navale is usually composed, in addition to the aircraft carrier, of:
This group is commanded by a rear admiral (contre-amiral, in French) on board the aircraft carrier. The commanding officer of the air group (usually a —equivalent to commander) is subordinate to the commanding officer of the aircraft carrier, a senior captain. The escort destroyers (called frigates in the French denomination) are commanded by more junior captains.
France also operates three s. While incapable of operating fixed-winged aircraft, they function as helicopter carriers and form the backbone of France's amphibious force. These ships are typically escorted by the same escorts the "Charles De Gaulle" uses.
The Indian Navy has been operating carrier battle groups since 1961, with its first carrier battle group formed around the now decommissioned . As of 2017, the Indian Navy operates one carrier battle group centered on . INS "Viraat" was an updated "Centaur"-class light carrier originally built for the Royal Navy as , which was laid down in 1944 and commissioned in 1959. It was purchased by India in May 1987, and was decommissioned in March 2017. India commissioned in 2013 and will follow this with a second carrier, the new INS "Vikrant" in 2020. INS "Vikramaditya" is the modified , INS "Vikrant" will be the first indigenous Indian aircraft carrier. India plans to have three carrier battle groups by 2025, each centered on "Vikrant", "Vikramaditya" and "Vishal", the second, larger and is expected to be nuclear-powered Vikrant-class carrier.
The Indian Navy's carrier battle group centered on "Viraat" consisted of two destroyers, usually of the (previously s were used), two or more frigates, usually of the , Godavari or Nilgiri classes, and one support ship.
The navy's new carrier battle group centered on "Vikramaditya" consists of the modern "Kolkata" class destroyers, "Shivalik" and "Talwar"-class frigates, "Kamorta"-class anti-submarine warfare corvettes and new tankers. INS "Chakra" is expected to fill the sub-surface component.
The CVS–ASW (Aircraft Carrier with Anti-Submarine Warfare) is Italy's first carrier. The battle group based in Taranto called COMFORAL is formed by the carrier "Giuseppe Garibaldi", two s, two support ships "Etna" and "Elettra", and three amphibious/support ships ("San Giusto", "San Marco" and "San Giorgio").
After 2010, the Italian battle group will be formed by the new carrier , 5–6 new warships (including destroyers "Horizon" and frigates FREMM), one new support ship, some minehunters and new submarines (the COMFORAL will be a reserve group).
"Admiral Kuznetsov" has been observed sailing together with a (CBGN), (CG), (ASuW), (ASW) and "Krivak" I/II FFG (ASW). These escorts, especially the heavily armed "Kirov"-class battlecruiser, use advanced sensors and carry a variety of weaponry. During "Admiral Kuznetsov"s deployment to Syria in November 2016 on her first combat tour, the carrier was escorted by a pair of Udaloy-class destroyers and a Kirov-class battlecruiser en route, while additional Russian Navy warships met her off Syria.
"Admiral Kuznetsov" is designed specifically to sail alone and carries greater firepower than her U.S. counterparts. This includes 12x SS-N-19 'Shipwreck' (long range, high speed, sea-skimming) SSMs, 24x VLS units loaded with 192 SA-N-9 'Gauntlet' SAMs, and 8x Kashtan CIWS with dual 30 mm guns, and 8x AK-630 CIWS. Compared to the 4x Phalanx CIWS and 4x Sea Sparrow launchers, each with 6 missiles carried by the "Nimitz"-class, "Admiral Kuznetsov" is well armed for both air-defence and offensive operations against hostile shipping.
As one of the pioneers of aircraft carriers, the Royal Navy has maintained a carrier strike capability since the commissioning of in 1918. However, the capability was temporarily lost between 2010 and 2018, following the retirement of the and Harrier GR7s. During this period, the Royal Navy worked to regenerate its carrier strike capability based on the Carrier-Enabled Power Projection (CEPP) concept by ordering two "Queen Elizabeth"-class aircraft carriers and the F-35B Lightning to operate from them. To maintain its skills and experience, the Royal Navy embedded personnel and ships with partner navies, in particular the United States Navy.
In 2017, the first "Queen Elizabeth"-class aircraft carrier entered service followed by her sister ship in 2019. The first carrier strike group took to sea in September 2019 as part of an exercise known as "Westlant 19". HMS "Queen Elizabeth" and her air group of F-35B Lightning jets operated alongside two surface escorts and a fleet tanker off the east coast of the United States. The deployment was in preparation for the first operational deployment in 2021, which is expected to involve HMS "Queen Elizabeth" alongside four Royal Navy escorts, two support ships and a submarine.
Under current plans, a Royal Navy carrier strike group will typically comprise a "Queen Elizabeth"-class aircraft carrier, two surface escorts, a submarine and a fleet tanker, however the composition varies depending on the operational tasking. Command of the UK carrier strike group is the responsibility of Commander United Kingdom Carrier Strike Group.
Since its origins, the viability of the carrier battle group has been dependent on its ability to remain at sea for extended periods. Specialized ships were developed to provide underway replenishment of fuel (for the carrier and its aircraft), ordnance, and other supplies necessary to sustain operations. Carrier battle groups devote a great deal of planning to efficiently conduct underway replenishment to minimize the time spent conducting replenishment. The carrier can also provide replenishment on a limited basis to its escorts, but typically a replenishment ship such as a fast combat support ship (AOE) or replenishment oiler (AOR) pulls alongside a carrier and conducts simultaneous operations with the carrier on its port side and one of the escorts on its starboard side. The advent of the helicopter provides the ability to speed replenishment by lifting supplies at the same time that fueling hoses and lines are delivering other goods.
There is debate in naval warfare circles as to the viability of carrier battle groups in 21st century naval warfare. Proponents of the CVBG argue that it provides unmatched firepower and force projection capabilities. Opponents argue that CVBGs are increasingly vulnerable to arsenal ships and cruise missiles, especially those with supersonic or even hypersonic flight and the ability to perform radical trajectory changes to avoid anti-missile systems. It is also noted that CVBGs were designed for Cold War scenarios, and are less useful in establishing control of areas close to shore. It is argued however that such missiles and arsenal ships pose no serious threat as they would be eliminated due to increasing improvement in ship defenses such as Cooperative Engagement Capability (CEC), DEW technology and missile technology.
However, carriers have been called upon to be first responders even when conventional land based aircraft were employed. During Desert Shield, the U.S. Navy sortied additional carriers to augment the on station assets eventually maintaining six carriers for Desert Storm. Although the U.S. Air Force sent fighters such as the F-16 to theater in Desert Shield, they had to carry bombs with them as no stores were in place for sustained operations, whereas the carriers arrived on scene with full magazines and had support ships to allow them to conduct strikes indefinitely.
The Global War on Terror has shown the flexibility and responsiveness of the carrier on multiple occasions when land based air was not feasible or able to respond in a timely fashion. After the September 11 terrorist attacks on the U.S., carriers immediately headed to the Arabian Sea to support Operation Enduring Freedom and took up station, building to a force of three carriers. Their steaming location was closer to the targets in Afghanistan than any land based assets and thereby more responsive. The was adapted to be a support base for special operations helicopters. Carriers were used again in Operation Iraqi Freedom and even provided aircraft to be based ashore on occasion and have done so periodically when special capabilities are needed. This precedent was established during World War II in the Battle of Guadalcanal.
Regardless of the debate over viability, the United States has made a major investment in the development of a new carrier class—the s (formerly designated CVN-X, or the X Carrier)—to replace the existing s. The new "Ford"-class carriers are designed to be modular and are easily adaptable as technology and equipment needed on board changes. | https://en.wikipedia.org/wiki?curid=7772 |
Boeing Vertol CH-46 Sea Knight
The Boeing Vertol CH-46 Sea Knight is a medium-lift tandem-rotor transport helicopter powered by twin turboshaft engines. It was designed by Vertol and manufactured by Boeing Vertol following Vertol's acquisition by Boeing.
Development of the Sea Knight, which was originally designated by the firm as the Vertol Model 107, commenced during 1956. It was envisioned as a successor to the first generation of rotorcraft, such as the H-21 "Flying Banana", that had been powered by piston engines; in its place, the V-107 made use of the emergent turboshaft engine. On 22 April 1958, the V-107 prototype performed its maiden flight. During June 1958, the US Army awarded a contract for the construction of ten production-standard aircraft, designated as the YHC-1A, based on the V-107; this initial order was later cut down to three YHC-1As though. During 1961, the US Marine Corps (USMC), who had been studying its requirements for a medium-lift, twin-turbine cargo/troop assault helicopter, selected Boeing Vertol's Model 107M as the basis from which to manufacture a suitable rotorcraft to meet their needs. Known colloquially as the "Phrog" and formally as the "Sea Knight", it was operated across all US Marine Corps' operational environments between its introduction during the Vietnam War and its frontline retirement during 2014.
The Sea Knight was operated by the USMC to provide all-weather, day-or-night assault transport of combat troops, supplies and equipment until it was replaced by the MV-22 Osprey during the 2010s. The USMC also used the helicopter for combat support, search and rescue (SAR), casualty evacuation and Tactical Recovery of Aircraft and Personnel (TRAP). The Sea Knight also functioned as the US Navy's standard medium-lift utility helicopter prior to the type being phased out of service in favor of the MH-60S Knighthawk during the early 2000s. Several overseas operators acquired the rotorcraft as well. Canada operated the Sea Knight, designated as CH-113; the type was used predominantly in the search and rescue (SAR) role until 2004. Other export customers for the type included Japan, Sweden, and Saudi Arabia. The commercial version of the rotorcraft is the BV 107-II, commonly referred to simply as the "Vertol".
During the 1940s and 1950s, American rotorcraft manufacturer Piasecki Helicopter emerged as a pioneering developer of tandem-rotor helicopters; perhaps the most famous of these being the piston-powered H-21 "Flying Banana", an early utility and transport helicopter. During 1955, Piasecki was officially renamed as Vertol Corporation (standing for vertical take-off and landing); it was around this time that work commenced on the development of a new generation of tandem rotor helicopter. During 1956, the new design received the internal company designation of "Vertol Model 107", or simply "V-107"; this rotorcraft differed from its predecessors by harnessing the newly developed turboshaft engine instead of piston-based counterparts. During that year, construction of a prototype, powered by a pair of Lycoming T53 turboshaft engines, each one being capable of producing 877 shp (640 kW), commenced.
On 22 April 1958, the V-107 prototype performed its maiden flight. In order to garner publicity for the newly developed rotorcraft, it was decided to use the prototype to conduct a series of publicised flight demonstrations during a tour across the United States and several overseas nations. During June 1958, it was announced that the U.S. Army had awarded a contract to Vertol for the construction of ten production-standard aircraft based on the V-107, which were designated "YHC-1A". However, this order was later decreased to three helicopters; according to aviation author Jay P. Spenser, the cutback had been enacted in order that the U.S. Army would be able to divert funds for the development of the rival "V-114" helicopter, which was also a turbine-powered tandem rotor design but substantially larger than the V-107. All of the U.S. Army's three YHC-1As were powered by pairs of GE-T-58 engines. During August 1959, the first YHC-1A-model rotorcraft conducted its first flight; independently, it was shortly followed by the maiden flight of an improved model intended for the commercial and export markets, designated "107-II".
During 1960, the U.S. Marine Corps evolved a requirement for a medium-lift, twin-turbine troop/cargo assault helicopter to replace the various piston-engined types that were then in widespread use with the service. That same year, American aviation company Boeing acquired Vertol, after which the group was consequently renamed Boeing Vertol. Following a competition between several competing designs, during early 1961, it was announced that Boeing Vertol had been selected to manufacture its model 107M for the U.S. Marine Corps, where it was designated "HRB-1". During 1962, the U.S. Air Force placed its own order for 12 "XCH-46B Sea Knight" helicopters, which used the "XH-49A" designation; however, the service later decided to cancel the order due to delays in its delivery; instead, the U.S. Air Force opted to procure the rival Sikorsky S-61R in its place.
Following the Sea Knight's first flight in August 1962, the military designation was changed to "CH-46A". During November 1964, the introduction of the Marines' CH-46A and the Navy's UH-46As commenced. The UH-46A variant was a modified version of the rotorcraft to perform the vertical replenishment mission. The CH-46A was equipped with a pair of T58-GE8-8B turboshaft engines, each being rated at 1,250 shp (930 kW); these allowed the Sea Knight to carry up to 17 passengers or a maximum of 4,000 pounds (1,815 kg) of cargo.
During 1966, production of the improved "CH-46D" commenced with deliveries following shortly thereafter. This model featured various improvements, including modified rotor blades and the adoption of more powerful T58-GE-10 turboshaft engines, rated at each. The increased power of these new engines allowed the CH-46D to carry an increased payload, such as up to 25 troops or a maximum of of cargo. During late 1967, the improved model was introduced to the Vietnam theater, where it supplemented the U.S. Marine Corps' existing CH-46A fleet, which had proven to be relatively unreliable and problematic in service. Along with the USMC's CH-46Ds, the U.S. Navy also acquired a small number of UH-46Ds for ship resupply purposes. In addition, approximately 33 CH-46As were progressively re-manufactured to the CH-46D standard.
Between 1968 and 1971, the U.S. Marine Corps received a number of CH-46F standard rotorcraft. This model retained the T58-GE-10 engines used on the CH-46D while featuring revised avionics and featured a number of other modifications. The CH-46F was the final production model of the type. During its service life, the Sea Knight received a variety of upgrades and modifications. Over time, the majority of the U.S. Marine Corps' Sea Knights were upgraded to the improved CH-46E standard. This model featured fiberglass rotor blades, reinforcement measures throughout the airframe, along with the refitting of further uprated T58-GE-16 engines, capable of producing each; in addition, several CH-46Es were modified to double their maximum fuel capacity. Starting in the mid-1990s, the Dynamic Component Upgrade (DCU) programmes was enacted, focusing on the implementation of strengthened drive systems and modified rotor controls.
The commercial variant, the "BV 107-II", was first ordered by New York Airways during 1960. During July 1962, they took delivery of their first three aircraft, which was configured to seat up to 25 passengers. During 1965, Boeing Vertol sold the manufacturing rights of the 107 to Japanese conglomerate Kawasaki Heavy Industries. Under this arrangement, all Model 107 civilian and military aircraft built in Japan were referred to by the "KV 107" designation. On 15 December 2006, Columbia Helicopters, Inc acquired the type certificate for the BV 107-II; at the time, the company was reportedly in the process of acquiring a Production Certificate from the Federal Aviation Administration (FAA). Plans for actual production of the aircraft were not announced.
The "Boeing Vertol CH-46 Sea Knight" is a medium-lift tandem-rotor transport helicopter, furnished with a set of counter-rotating main rotors in a tandem-rotor configuration. It was typically powered by a pair of General Electric T58 turboshaft engines, which were mounted on each side of the rear rotor pedestal; power to the forward rotor was transferred from the rear-mounted engines via a drive shaft. For redundancy, both engines are coupled so that either one would be capable of powering both of the main rotors in the event of a single engine failure or a similar emergency situation. Each of the rotors feature three blades, which can be folded to better facilitate storage and naval operations. The CH-46 features a fixed tricycle landing gear, complete with twin wheels on all three legs of the landing gear; this configuration results in a nose-up stance, helping to facilitate cargo loading and unloading. Two of the main landing gear were installed within protruding rear sponsons; the free interior space of the sponsons are also used to house fuel tanks, possessing a total capacity of 350 US gallons (1,438 L).
The interior of the CH-46 was largely taken up by its cargo bay, complete with a rear loading ramp that could be removed or left open in flight for the carriage of extended cargoes or for parachute drops. Various furnishings were normally provided to aid in its use as a utility rotorcraft, such as an internal winch mounted within the forward cabin, which can be used to assisting loading by pulling external cargo on pallets into the aircraft via the ramp and rollers, and an optionally-attached belly-mounted cargo hook, which would be usually rated at for carrying cargoes externally underneath the Sea Knight; despite the hook having been rated at , this was safety restricted to less payload as they got older. When operated in a typical configuration, the CH-46 would usually be operated by a crew of three; a larger crew could be accommodated when required, which would be dependent upon mission specifics. For example, a search and rescue (SAR) variant would usually carry a crew of five (Pilot, Co-Pilot, Crew Chief, Swimmer, and Medic) to facilitate all aspects of such operations. For self-defense, a pintle-mounted 0.50 in (12.7 mm) Browning machine gun could be mounted on each side of the helicopter. Service in southeast Asia resulted in the addition of armor along with the machine guns.
Known colloquially as the "Phrog", the Sea Knight was used in all U.S. Marine operational environments between its introduction during the Vietnam War and its frontline retirement in 2014. The type's longevity and reputation for reliability led to mantras such as "phrogs phorever" and "never trust a helicopter under 30". CH-46s transported personnel, evacuated wounded, supplied forward arming and refueling points (FARP), performed vertical replenishment, search and rescue, recovered downed aircraft and crews and other tasks.
During the Vietnam War, the CH-46 was one of the prime US Marine troop transport helicopters in the theater, slotting between the smaller Bell UH-1 Iroquois and larger Sikorsky CH-53 Sea Stallion. CH-46 operations were plagued by major technical problems; the engines, being prone to foreign object damage (FOD) from debris being ingested when hovering close to the ground and subsequently suffering a compressor stall, had a lifespan as low as 85 flight hours; on 21 July 1966, all CH-46s were grounded until more efficient filters had been fitted.
On 3 May 1967, a CH-46D at Marine Corps Air Facility Santa Ana crashed, killing all four members of the crew. Within three days the accident investigators had determined that the mounting brackets of the main transmission had failed, allowing the front and rear overlapping rotors to intermesh. All CH–46s were temporarily grounded for inspection. On 13 May, a CH–46A crashed off the coast of Vietnam when the tail pylon containing the engines, main transmission and aft rotors broke off in flight. All four crew members were killed. On 20 June, another CH–46A crashed, though two of the four-man crew survived. Once again, even though the aircraft was not recovered from the water, failure of some sort in the rear pylon was suspected. On 30 June a CH-46D at Santa Ana crashed when a rotor blade separated from the aircraft, all three of the crew survived. As a result of this latest accident, all CH-46Ds were immediately grounded, but the CH-46As continued flying. On 3 July another CH-46A crashed in Vietnam, killing all four Marines of its crew. The cause of the crash again was traced to failure of the main transmission.
On 31 August 1967, a CH-46A on a medical evacuation mission to disintegrated in midair killing all its occupants. The following day another CH-46A experienced a similar incident at Marble Mountain Air Facility leading to the type being grounded for all except emergency situations and cutting Marine airlift capacity in half. An investigation conducted by a joint Naval Air Systems Command/Boeing Vertol accident investigation team revealed that structural failures were occurring in the area of the rear pylon resulting in the rear rotor tearing off in flight and may have been the cause of several earlier losses. The team recommended structural and systems modifications to reinforce the rear rotor mount as well as installation of an indicator to detect excessive strain on critical parts of the aircraft. 80 CH-46As were shipped to Marine Corps Air Station Futenma, Okinawa where they received the necessary modifications by a combined force of Marine and Boeing Vertol personnel. The modified CH-46As began returning to service in December 1967 and all had been returned to service by February 1968.
During the 1972 Easter Offensive, Sea Knights saw heavy use to convey US and South Vietnamese ground forces to and around the front lines. By the end of US military operations in Vietnam, over a hundred Sea Knights had been lost to enemy fire.
In February 1968 the Marine Corps Development and Education Command obtained several CH-46s to perform herbicide dissemination tests using HIDAL (Helicopter, Insecticide Dispersal Apparatus, Liquid) systems; testing indicated the need for redesign and further study. Tandem-rotor helicopters were often used to transport nuclear warheads; the CH-46A was evaluated to deploy Naval Special Forces with the Special Atomic Demolition Munition (SADM). Nuclear Weapon Accident Exercise 1983 (NUWAX-83), simulating the crash of a Navy CH-46E carrying 3 nuclear warheads, was conducted at the Nevada Test Site on behalf of several federal agencies; the exercise, which used real radiological agents, was depicted in a Defense Nuclear Agency-produced documentary.
U.S. Marine CH-46s were used to deploy the 8th Marine Regiment into Grenada during Operation Urgent Fury, evacuated the surviving crewmember of a downed AH-1 Cobra, and then carried infantry from the 75th Ranger Regiment to secure and evacuate U.S. students at the Grand Anse campus of St. George's University, though one crashed after colliding with a palm tree.
CH-46E Sea Knights were also used by the U.S. Marine Corps during the 2003 invasion of Iraq. In one incident on 1 April 2003, Marine CH-46Es and CH-53Es carried U.S. Army Rangers and Special Operations troops on an extraction mission for captured Army Private Jessica Lynch from an Iraqi hospital. During the subsequent occupation of Iraq and counter-insurgency operations, the CH-46E was heavily used in the CASEVAC role, being required to maintain 24/7 availability regardless of conditions. According to authors Williamson Murray and Robert H Scales, the Sea Knight displayed serious reliability and maintenance problems during its deployment to Iraq, as well as "limited lift capabilities". Following the loss of numerous US helicopters in the Iraqi theatre, the Marines opted to equip their CH-46s with more advanced anti-missile countermeasures.
The U.S. Navy retired the type on 24 September 2004, replacing it with the MH-60S Seahawk; the Marine Corps maintained its fleet as the MV-22 Osprey was fielded. In March 2006 Marine Medium Helicopter Squadron 263 (HMM-263) was deactivated and redesignated VMM-263 to serve as the first MV-22 squadron. The replacement process continued through the other medium helicopter squadrons into 2014. On 5 October 2014, the Sea Knight performed its final service flight with the U.S. Marine Corps at Marine Corps Air Station Miramar. HMM-364 was the last squadron to use it outside the United States, landing it aboard on her maiden transit. On 9 April 2015, the CH-46 was retired by the Marine Medium Helicopter Training Squadron 164, the last Marine Corps squadron to transition to the MV-22. The USMC retired the CH-46 on 1 August 2015 in a ceremony at the Udvar-Hazy Center near Washington DC. The HH-46E variant continued to operate in a Search and Rescue capacity at Marine Corps Air Station Cherry Point. The last flight of a Marine Corps H-46 took place on 25 September 2015 at MCAS Cherry Point and ended the 57-year Cherry Point Search and Rescue program.
The Royal Canadian Air Force procured six CH-113 Labrador helicopters for the SAR role and the Canadian Army acquired 12 of the similar "CH-113A Voyageur" for the medium-lift transport role. The RCAF Labradors were delivered first with the first one entering service on 11 October 1963. When the larger CH-147 Chinook was procured by the Canadian Forces in the mid-1970s, the Voyageur fleet was converted to Labrador specifications to undertake SAR missions. The refurbished Voyageurs were re-designated as CH-113A Labradors, thus a total of 15 Labradors were ultimately in service.
The Labrador was fitted with a watertight hull for marine landings, a 5,000 kilogram cargo hook and an external rescue hoist mounted over the right front door. It featured a 1,110 kilometer flying range, emergency medical equipment and an 18-person passenger capacity. By the 1990s, heavy use and hostile weather conditions had taken their toll on the Labrador fleet, resulting in increasing maintenance costs and the need for prompt replacement. In 1981, a mid-life upgrade of the fleet was carried out by Boeing Canada in Arnprior, Ontario. Known as the SAR-CUP (Search and Rescue Capability Upgrade Program), the refit scheme included new instrumentation, a nose-mounted weather radar, a tail-mounted auxiliary power unit, a new high-speed rescue hoist mounted over the side door and front-mounted searchlights. A total of six CH-113s and five CH-113As were upgraded with the last delivered in 1984.
In 1992, it was announced that the Labradors were to be replaced by 15 new helicopters, a variant of the AgustaWestland EH101, designated "CH-149 Chimo". The order was subsequently cancelled by the Jean Chrétien Liberal government in 1993, resulting in cancellation penalties, as well as extending the service life of the Labrador fleet. However, in 1998, a CH-113 from CFB Greenwood crashed on Quebec's Gaspé Peninsula while returning from a SAR mission, resulting in the deaths of all crewmembers on board. The crash placed pressure upon the government to procure a replacement, thus an order was placed with the manufacturers of the EH101 for 15 aircraft to perform the search-and-rescue mission, designated "CH-149 Cormorant". CH-149 deliveries began in 2003, allowing the last CH-113 to be retired in 2004. In October 2005 Columbia Helicopters of Aurora, Oregon purchased eight of the retired CH-113 Labradors to add to their fleet of 15 Vertol 107-II helicopters.
In 1963, Sweden procured ten UH-46Bs from the US as a transport and anti-submarine helicopter for the Swedish armed forces, designated Hkp 4A. In 1973, a further eight Kawasaki-built KV-107s, which were accordingly designated Hkp 4B, were acquired to replace the older Piasecki H-21. During the Cold War, the fleet's primary missions were anti-submarine warfare and troop transportation, they were also frequently employed in the search and rescue role. In the 1980s, the Hkp 4A was phased out, having been replaced by the Eurocopter AS332 Super Puma; the later Kawasaki-built Sea Knights continued in operational service until 2011, they were replaced by the UH-60 Black Hawk & NH90.
The civilian version, designated as the BV 107-II "Vertol", was developed prior to the military CH-46. It was operated commercially by New York Airways, Pan American World Airways and later on by Columbia Helicopters. Among the diversity of tasks was pulling a hover barge, and constructing transmission towers for overhead power lines.
In December 2006, Columbia Helicopters purchased the type certificate of the Model 107 from Boeing, with the aim of eventually producing new-build aircraft themselves.
Source: | https://en.wikipedia.org/wiki?curid=7773 |
Chief of Naval Operations
The Chief of Naval Operations (CNO) is the head of the United States Navy. The position is a statutory office () held by a four-star admiral who is a military adviser and deputy to the Secretary of the Navy. In a separate capacity as a member of the Joint Chiefs of Staff () the CNO is a military adviser to the National Security Council, the Homeland Security Council, the Secretary of Defense, and the President. The current Chief of Naval Operations is Admiral Michael M. Gilday.
Despite the title, the CNO does not have operational command authority over Naval forces. The CNO is an administrative position based in the Pentagon, and exercises supervision of Navy organizations as the designee of the Secretary of the Navy. Operational command of naval forces falls within the purview of the Combatant Commanders who report to the Secretary of Defense.
The Chief of Naval Operations (CNO) is typically the highest-ranking officer on active duty in the U.S. Navy unless the Chairman and/or the Vice Chairman of the Joint Chiefs of Staff are naval officers.
As per , whenever there is a vacancy for the Chief of Naval Operations or during the absence or disability of the Chief of Naval Operations, and unless the President directs otherwise, the Vice Chief of Naval Operations performs the duties of the Chief of Naval Operations until a successor is appointed or the absence or disability ceases.
The CNO also performs all other functions prescribed under , such as presiding over the Office of the Chief of Naval Operations (OPNAV), exercising supervision of Navy organizations, and other duties assigned by the Secretary or higher lawful authority, or the CNO delegates those duties and responsibilities to other officers in OPNAV or in organizations below.
Acting for the Secretary of the Navy, the CNO also designates naval personnel and naval forces available to the commanders of Unified Combatant Commands, subject to the approval of the Secretary of Defense.
The CNO is a member of the Joint Chiefs of Staff as prescribed by and . Like the other members of the Joint Chiefs of Staff, the CNO is an administrative position, with no operational command authority over the United States Navy forces.
Members of the Joint Chiefs of Staff, individually or collectively, in their capacity as military advisers, shall provide advice to the President, the National Security Council (NSC), or the Secretary of Defense (SECDEF) on a particular matter when the President, the NSC, or SECDEF requests such advice. Members of the Joint Chiefs of Staff (other than the Chairman of the Joint Chiefs of Staff) may submit to the Chairman advice or an opinion in disagreement with, or advice or an opinion in addition to, the advice presented by the Chairman to the President, NSC, or SECDEF.
When performing his JCS duties, the CNO is responsible directly to the SECDEF, but keeps SECNAV fully informed of significant military operations affecting the duties and responsibilities of the SECNAV, unless SECDEF orders otherwise.
The Chief of Naval Operations is nominated by the President for appointment and must be confirmed by the Senate. A requirement for being Chief of Naval Operations is having significant experience in joint duty assignments, which includes at least one full tour of duty in a joint duty assignment as a flag officer. However, the president may waive those requirements if he determines that appointing the officer is necessary for the national interest. By statute, the CNO is appointed as a four-star admiral.
Number One Observatory Circle, located on the northeast grounds of the United States Naval Observatory in Washington, DC, was built in 1893 for its superintendent. The Chief of Naval Operations liked the house so much that in 1923 he took over the house as his own official residence. It remained the residence of the CNO until 1974, when Congress authorized its transformation to an official residence for the Vice President. The Chief of Naval Operations currently resides in Quarters A in the Washington Naval Yard.
The Chief of Naval Operations presides over the Navy Staff, formally known as the Office of the Chief of Naval Operations (OPNAV).
The Office of the Chief of Naval Operations is a statutory organization within the executive part of the Department of the Navy, and its purpose is to furnish professional assistance to the Secretary of the Navy (SECNAV) and the CNO in carrying out their responsibilities.
The OPNAV organization consists of:
Policy documents emanating from the CNO are issued in the form of OPNAV Instructions.
OPNAV is one of the three headquarters staffs in Department of the Navy mainly based at The Pentagon, with the others being the Office of the Secretary of the Navy and Headquarters, Marine Corps.
The position of CNO replaced the position of Aide for Naval Operations, which was a position established by regulation rather than statutory law. († - "died in office") | https://en.wikipedia.org/wiki?curid=7774 |
Coriolis force
In physics, the Coriolis force is an inertial or fictitious force that acts on objects that are in motion within a frame of reference that rotates with respect to an inertial frame. In a reference frame with clockwise rotation, the force acts to the left of the motion of the object. In one with anticlockwise (or counterclockwise) rotation, the force acts to the right. Deflection of an object due to the Coriolis force is called the Coriolis effect. Though recognized previously by others, the mathematical expression for the Coriolis force appeared in an 1835 paper by French scientist Gaspard-Gustave de Coriolis, in connection with the theory of water wheels. Early in the 20th century, the term "Coriolis force" began to be used in connection with meteorology.
Newton's laws of motion describe the motion of an object in an inertial (non-accelerating) frame of reference. When Newton's laws are transformed to a rotating frame of reference, the Coriolis and centrifugal accelerations appear. When applied to massive objects, the respective forces are proportional to the masses of them. The Coriolis force is proportional to the rotation rate and the centrifugal force is proportional to the square of the rotation rate. The Coriolis force acts in a direction perpendicular to the rotation axis and to the velocity of the body in the rotating frame and is proportional to the object's speed in the rotating frame (more precisely, to the component of its velocity that is perpendicular to the axis of rotation). The centrifugal force acts outwards in the radial direction and is proportional to the distance of the body from the axis of the rotating frame. These additional forces are termed inertial forces, fictitious forces or "pseudo forces". They "allow" the application of Newton's laws to a rotating system. They are correction factors that do not exist in a non-accelerating or inertial reference frame.
In popular (non-technical) usage of the term "Coriolis effect", the rotating reference frame implied is almost always the Earth. Because the Earth spins, Earth-bound observers need to account for the Coriolis force to correctly analyze the motion of objects. The Earth completes one rotation per day, so for motions of everyday objects the Coriolis force is usually quite small compared with other forces; its effects generally become noticeable only for motions occurring over large distances and long periods of time, such as large-scale movement of air in the atmosphere or water in the ocean. Such motions are constrained by the surface of the Earth, so only the horizontal component of the Coriolis force is generally important. This force causes moving objects on the surface of the Earth to be deflected to the right (with respect to the direction of travel) in the Northern Hemisphere and to the left in the Southern Hemisphere. The horizontal deflection effect is greater near the poles, since the effective rotation rate about a local vertical axis is largest there, and decreases to zero at the equator. Rather than flowing directly from areas of high pressure to low pressure, as they would in a non-rotating system, winds and currents tend to flow to the right of this direction north of the equator (anticlockwise) and to the left of this direction south of it (clockwise). This effect is responsible for the rotation of large cyclones (see Coriolis effects in meteorology).
For an intuitive explanation of the origin of the Coriolis force, consider an object, constrained to follow the Earth's surface and moving northward in the northern hemisphere. Viewed from outer space, the object does not appear to go due north, but has an eastward motion (it rotates around toward the right along with the surface of the Earth). The further north it travels, the smaller the "diameter of its parallel" (the minimum distance from the surface point to the axis of rotation, which is in a plane orthogonal to the axis), and so the slower the eastward motion of its surface. As the object moves north, to higher latitudes, it has a tendency to maintain the eastward speed it started with (rather than slowing down to match the reduced eastward speed of local objects on the Earth's surface), so it veers east (i.e. to the right of its initial motion).
Though not obvious from this example, which considers northward motion, the horizontal deflection occurs equally for objects moving eastward or westward (or in any other direction).However, the theory that the effect influences draining water to rotate anti-clockwise in the northern hemisphere and clockwise in the southern hemisphere has been repeatedly disproven by modern-day scientists.
Italian scientist Giovanni Battista Riccioli and his assistant Francesco Maria Grimaldi described the effect in connection with artillery in the 1651 "Almagestum Novum", writing that rotation of the Earth should cause a cannonball fired to the north to deflect to the east. In 1674 Claude François Milliet Dechales described in his "Cursus seu Mundus Mathematicus" how the rotation of the Earth should cause a deflection in the trajectories of both falling bodies and projectiles aimed toward one of the planet's poles. Riccioli, Grimaldi, and Dechales all described the effect as part of an argument against the heliocentric system of Copernicus. In other words, they argued that the Earth's rotation should create the effect, and so failure to detect the effect was evidence for an immobile Earth. The Coriolis acceleration equation was derived by Euler in 1749, and the effect was described in the tidal equations of Pierre-Simon Laplace in 1778.
Gaspard-Gustave Coriolis published a paper in 1835 on the energy yield of machines with rotating parts, such as waterwheels. That paper considered the supplementary forces that are detected in a rotating frame of reference. Coriolis divided these supplementary forces into two categories. The second category contained a force that arises from the cross product of the angular velocity of a coordinate system and the projection of a particle's velocity into a plane perpendicular to the system's axis of rotation. Coriolis referred to this force as the "compound centrifugal force" due to its analogies with the centrifugal force already considered in category one. The effect was known in the early 20th century as the "acceleration of Coriolis", and by 1920 as "Coriolis force".
In 1856, William Ferrel proposed the existence of a circulation cell in the mid-latitudes with air being deflected by the Coriolis force to create the prevailing westerly winds.
The understanding of the kinematics of how exactly the rotation of the Earth affects airflow was partial at first. Late in the 19th century, the full extent of the large scale interaction of pressure-gradient force and deflecting force that in the end causes air masses to move along isobars was understood.
In Newtonian mechanics, the equation of motion for an object in an inertial reference frame is
where formula_5 is the vector sum of the physical forces acting on the object, formula_6 is the mass of the object, and formula_7 is the acceleration of the object relative to the inertial reference frame.
Transforming this equation to a reference frame rotating about a fixed axis through the origin with rotation vector formula_8 having variable rotation rate, the equation takes the form
where
The fictitious forces as they are perceived in the rotating frame act as additional forces that contribute to the apparent acceleration just like the real external forces. The fictitious force terms of the equation are, reading from left to right:
Notice the Euler and centrifugal forces depend on the position vector formula_20 of the object, while the Coriolis force depends on the object's velocity formula_21 as measured in the rotating reference frame. As expected, for a non-rotating inertial frame of reference formula_22 the Coriolis force and all other fictitious forces disappear. The forces also disappear for zero mass formula_23.
As the Coriolis force is proportional to a cross product of two vectors, it is perpendicular to both vectors, in this case the object's velocity and the frame's rotation vector. It therefore follows that:
The Coriolis force exists only when one uses a rotating reference frame. In the rotating frame it behaves exactly like a real force (that is to say, it causes acceleration and has real effects). However, the Coriolis force is a consequence of inertia, and is not attributable to an identifiable originating body, as is the case for electromagnetic or nuclear forces, for example. From an analytical viewpoint, to use Newton's second law in a rotating system, the Coriolis force is mathematically necessary, but it disappears in a non-accelerating, inertial frame of reference. For example, consider two children on opposite sides of a spinning roundabout (Merry-go-round), who are throwing a ball to each other. From the children's point of view, this ball's path is curved sideways by the Coriolis force. Suppose the roundabout spins anticlockwise when viewed from above. From the thrower's perspective, the deflection is to the right. From the non-thrower's perspective, deflection is to the left (for a mathematical formulation see Mathematical derivation of fictitious forces). In meteorology, a rotating frame (the Earth) with its Coriolis force provides a more natural framework for explanation of air movements than a non-rotating inertial frame without Coriolis forces. In long-range gunnery, sight corrections for the Earth's rotation are based on the Coriolis force. These examples are described in more detail below.
The acceleration entering the Coriolis force arises from two sources of change in velocity that result from rotation: the first is the change of the velocity of an object in time. The same velocity (in an inertial frame of reference where the normal laws of physics apply) is seen as different velocities at different times in a rotating frame of reference. The apparent acceleration is proportional to the angular velocity of the reference frame (the rate at which the coordinate axes change direction), and to the component of velocity of the object in a plane perpendicular to the axis of rotation. This gives a term formula_24. The minus sign arises from the traditional definition of the cross product (right-hand rule), and from the sign convention for angular velocity vectors.
The second is the change of velocity in space. Different positions in a rotating frame of reference, with a constant angular velocity, have different linear velocities (as seen from an inertial frame of reference, velocity is higher the further away the position is from the center of rotation). For an object to move in a straight line, it must accelerate so that its velocity changes from point to point by the same amount as the velocities of the frame of reference. The force is proportional to the angular velocity (which determines the relative speed of two different points in the rotating frame of reference), and to the component of the velocity of the object in a plane perpendicular to the axis of rotation (which determines how quickly it moves between those points). This also gives a term formula_24.
The time, space and velocity scales are important in determining the importance of the Coriolis force. Whether rotation is important in a system can be determined by its Rossby number, which is the ratio of the velocity, "U", of a system to the product of the Coriolis parameter,formula_26, and the length scale, "L", of the motion:
The Rossby number is the ratio of inertial to Coriolis forces. A small Rossby number indicates a system is strongly affected by Coriolis forces, and a large Rossby number indicates a system in which inertial forces dominate. For example, in tornadoes, the Rossby number is large, in low-pressure systems it is low, and in oceanic systems it is around 1. As a result, in tornadoes the Coriolis force is negligible, and balance is between pressure and centrifugal forces. In low-pressure systems, centrifugal force is negligible and balance is between Coriolis and pressure forces. In the oceans all three forces are comparable.
An atmospheric system moving at "U" = occupying a spatial distance of "L" = , has a Rossby number of approximately 0.1.
A baseball pitcher may throw the ball at U = for a distance of L = . The Rossby number in this case would be 32,000.
Baseball players don't care about which hemisphere they're playing in. However, an unguided missile obeys exactly the same physics as a baseball, but can travel far enough and be in the air long enough to experience the effect of Coriolis force. Long-range shells in the Northern Hemisphere landed close to, but to the right of, where they were aimed until this was noted. (Those fired in the Southern Hemisphere landed to the left.) In fact, it was this effect that first got the attention of Coriolis himself.
The animation at the top of this article is a classic illustration of Coriolis force. Another visualization of the Coriolis and centrifugal forces is this animation clip.
Given the radius "R" of the turntable in that animation, the rate of angular rotation ω, and the speed of the cannonball (assumed constant) "v", the correct angle θ to aim so as to hit the target at the edge of the turntable can be calculated.
The inertial frame of reference provides one way to handle the question: calculate the time to interception, which is "tf" = "R" / "v" . Then, the turntable revolves an angle ω "tf" in this time. If the cannon is pointed an angle θ = ω "tf" = ω "R" / "v", then the cannonball arrives at the periphery at position number 3 at the same time as the target.
No discussion of Coriolis force can arrive at this solution as simply, so the reason to treat this problem is to demonstrate Coriolis formalism in an easily visualized situation.
The trajectory in the inertial frame (denoted "A") is a straight line radial path at angle θ. The position of the cannonball in ("x", "y") coordinates at time "t" is:
In the turntable frame (denoted "B"), the "x"- "y" axes rotate at angular rate ω, so the trajectory becomes:
and three examples of this result are plotted in the figure.
To determine the components of acceleration, a general expression is used from the article fictitious force:
in which the term in -2 Ω × vB is the Coriolis acceleration and the term in -Ω × (Ω × rB) is the centrifugal acceleration. The results are (let α = θ − ω"t"):
Producing a centrifugal acceleration:
Also:
producing a Coriolis acceleration:
These accelerations are shown in the diagrams for a particular example.
It is seen that the Coriolis acceleration not only cancels the centrifugal acceleration, but together they provide a net "centripetal", radially inward component of acceleration (that is, directed toward the center of rotation):
and an additional component of acceleration perpendicular to rB("t"):
The "centripetal" component of acceleration resembles that for circular motion at radius "r"B, while the perpendicular component is dependent on the constant radial velocity "v" and is directed to the right of the velocity. The situation could be described as a circular motion combined with an "apparent Coriolis acceleration" of 2ω"v". However, this is a rough labelling: a careful designation of the true centripetal force refers to a local reference frame that employs the directions normal and tangential to the path, not coordinates referred to the axis of rotation.
These results also can be obtained directly by two time differentiations of rB("t"). Agreement of the two approaches demonstrates that one could start from the general expression for fictitious acceleration above and derive the trajectories shown here. However, working from the acceleration to the trajectory is more complicated than the reverse procedure used here, which is made possible in this example by knowing the answer in advance.
As a result of this analysis an important point appears: "all" the fictitious accelerations must be included to obtain the correct trajectory. In particular, besides the Coriolis acceleration, the centrifugal force plays an essential role. It is easy to get the impression from verbal discussions of the cannonball problem, which focus on displaying the Coriolis effect particularly, that the Coriolis force is the only factor that must be considered, but that is not so. A turntable for which the Coriolis force "is" the only factor is the parabolic turntable. A somewhat more complex situation is the idealized example of flight routes over long distances, where the centrifugal force of the path and aeronautical lift are countered by gravitational attraction.
The figure illustrates a ball tossed from 12:00 o'clock toward the center of a counter-clockwise rotating carousel. On the left, the ball is seen by a stationary observer above the carousel, and the ball travels in a straight line to the center, while the ball-thrower rotates counter-clockwise with the carousel. On the right the ball is seen by an observer rotating with the carousel, so the ball-thrower appears to stay at 12:00 o'clock. The figure shows how the trajectory of the ball as seen by the rotating observer can be constructed.
On the left, two arrows locate the ball relative to the ball-thrower. One of these arrows is from the thrower to the center of the carousel (providing the ball-thrower's line of sight), and the other points from the center of the carousel to the ball. (This arrow gets shorter as the ball approaches the center.) A shifted version of the two arrows is shown dotted.
On the right is shown this same dotted pair of arrows, but now the pair are rigidly rotated so the arrow corresponding to the line of sight of the ball-thrower toward the center of the carousel is aligned with 12:00 o'clock. The other arrow of the pair locates the ball relative to the center of the carousel, providing the position of the ball as seen by the rotating observer. By following this procedure for several positions, the trajectory in the rotating frame of reference is established as shown by the curved path in the right-hand panel.
The ball travels in the air, and there is no net force upon it. To the stationary observer, the ball follows a straight-line path, so there is no problem squaring this trajectory with zero net force. However, the rotating observer sees a "curved" path. Kinematics insists that a force (pushing to the "right" of the instantaneous direction of travel for a "counter-clockwise" rotation) must be present to cause this curvature, so the rotating observer is forced to invoke a combination of centrifugal and Coriolis forces to provide the net force required to cause the curved trajectory.
The figure describes a more complex situation where the tossed ball on a turntable bounces off the edge of the carousel and then returns to the tosser, who catches the ball. The effect of Coriolis force on its trajectory is shown again as seen by two observers: an observer (referred to as the "camera") that rotates with the carousel, and an inertial observer. The figure shows a bird's-eye view based upon the same ball speed on forward and return paths. Within each circle, plotted dots show the same time points. In the left panel, from the camera's viewpoint at the center of rotation, the tosser (smiley face) and the rail both are at fixed locations, and the ball makes a very considerable arc on its travel toward the rail, and takes a more direct route on the way back. From the ball tosser's viewpoint, the ball seems to return more quickly than it went (because the tosser is rotating toward the ball on the return flight).
On the carousel, instead of tossing the ball straight at a rail to bounce back, the tosser must throw the ball toward the right of the target and the ball then seems to the camera to bear continuously to the left of its direction of travel to hit the rail ("left" because the carousel is turning "clockwise"). The ball appears to bear to the left from direction of travel on both inward and return trajectories. The curved path demands this observer to recognize a leftward net force on the ball. (This force is "fictitious" because it disappears for a stationary observer, as is discussed shortly.) For some angles of launch, a path has portions where the trajectory is approximately radial, and Coriolis force is primarily responsible for the apparent deflection of the ball (centrifugal force is radial from the center of rotation, and causes little deflection on these segments). When a path curves away from radial, however, centrifugal force contributes significantly to deflection.
The ball's path through the air is straight when viewed by observers standing on the ground (right panel). In the right panel (stationary observer), the ball tosser (smiley face) is at 12 o'clock and the rail the ball bounces from is at position one (1). From the inertial viewer's standpoint, positions one (1), two (2), three (3) are occupied in sequence. At position 2 the ball strikes the rail, and at position 3 the ball returns to the tosser. Straight-line paths are followed because the ball is in free flight, so this observer requires that no net force is applied.
The concept "Coriolis force" is specially suitable for the description of motion of atmosphere (i.e. winds) over the surface of the Earth. The Earth (like all rotating celestial bodies) has taken the shape of an oblate spheroid, such that the gravitational force is slightly off-set towards the Earth axis as illustrated in the figure. For a mass point at rest on the Earth surface the horizontal component of the gravitation counteracts the "centrifugal force" preventing it to slide away towards the equator. This means that the vector term of the "equation of motion" above
is directed straight down, orthogonal to the surface of the Earth. The force affecting the motion of air "sliding" over the Earth surface is therefore (only) the horizontal component of the Coriolis term
This component is orthogonal to the velocity over the Earth surface and is given by the expression
where
In the northern hemisphere where the sign is positive this force/acceleration, as viewed from above, is to the right of the direction of motion, in the southern hemisphere where the sign is negative this force/acceleration is to the left of the direction of motion
As the Earth rotates about its axis, everything attached to it, including the atmosphere, turns with it (imperceptibly to our senses). An object that is moving without being dragged along with the surface rotation or atmosphere such as an object in ballistic flight or an independent air mass within the atmosphere, travels in a straight motion over the turning Earth. From our rotating perspective on the planet, the direction of motion of an object in ballistic flight changes as it moves, bending in the opposite direction to our actual motion.
When viewed from a stationary point in space directly above the north pole, any land feature in the Northern Hemisphere turns anticlockwise—and, fixing our gaze on that location, any other location in that hemisphere rotates around it the same way. The traced ground path of a freely moving body in ballistic flight traveling from one point to another therefore bends the opposite way, clockwise, which is conventionally labeled as "right," where it will be if the direction of motion is considered "ahead," and "down" is defined naturally.
Consider a location with latitude "φ" on a sphere that is rotating around the north-south axis. A local coordinate system is set up with the "x" axis horizontally due east, the "y" axis horizontally due north and the "z" axis vertically upwards. The rotation vector, velocity of movement and Coriolis acceleration expressed in this local coordinate system (listing components in the order east ("e"), north ("n") and upward ("u")) are:
When considering atmospheric or oceanic dynamics, the vertical velocity is small, and the vertical component of the Coriolis acceleration is small compared with the acceleration due to gravity. For such cases, only the horizontal (east and north) components matter. The restriction of the above to the horizontal plane is (setting "vu" = 0):
where formula_26 is called the Coriolis parameter.
By setting "vn" = 0, it can be seen immediately that (for positive φ and ω) a movement due east results in an acceleration due south. Similarly, setting "ve" = 0, it is seen that a movement due north results in an acceleration due east. In general, observed horizontally, looking along the direction of the movement causing the acceleration, the acceleration always is turned 90° to the right and of the same size regardless of the horizontal orientation.
As a different case, consider equatorial motion setting φ = 0°. In this case, Ω is parallel to the north or "n"-axis, and:
Accordingly, an eastward motion (that is, in the same direction as the rotation of the sphere) provides an upward acceleration known as the Eötvös effect, and an upward motion produces an acceleration due west.
Perhaps the most important impact of the Coriolis effect is in the large-scale dynamics of the oceans and the atmosphere. In meteorology and oceanography, it is convenient to postulate a rotating frame of reference wherein the Earth is stationary. In accommodation of that provisional postulation, the centrifugal and Coriolis forces are introduced. Their relative importance is determined by the applicable Rossby numbers. Tornadoes have high Rossby numbers, so, while tornado-associated centrifugal forces are quite substantial, Coriolis forces associated with tornadoes are for practical purposes negligible.
Because surface ocean currents are driven by the movement of wind over the water's surface, the Coriolis force also affects the movement of ocean currents and cyclones as well. Many of the ocean's largest currents circulate around warm, high-pressure areas called gyres. Though the circulation is not as significant as that in the air, the deflection caused by the Coriolis effect is what creates the spiralling pattern in these gyres. The spiralling wind pattern helps the hurricane form. The stronger the force from the Coriolis effect, the faster the wind spins and picks up additional energy, increasing the strength of the hurricane.
Air within high-pressure systems rotates in a direction such that the Coriolis force is directed radially inwards, and nearly balanced by the outwardly radial pressure gradient. As a result, air travels clockwise around high pressure in the Northern Hemisphere and anticlockwise in the Southern Hemisphere. Air around low-pressure rotates in the opposite direction, so that the Coriolis force is directed radially outward and nearly balances an inwardly radial pressure gradient.
If a low-pressure area forms in the atmosphere, air tends to flow in towards it, but is deflected perpendicular to its velocity by the Coriolis force. A system of equilibrium can then establish itself creating circular movement, or a cyclonic flow. Because the Rossby number is low, the force balance is largely between the pressure-gradient force acting towards the low-pressure area and the Coriolis force acting away from the center of the low pressure.
Instead of flowing down the gradient, large scale motions in the atmosphere and ocean tend to occur perpendicular to the pressure gradient. This is known as geostrophic flow. On a non-rotating planet, fluid would flow along the straightest possible line, quickly eliminating pressure gradients. The geostrophic balance is thus very different from the case of "inertial motions" (see below), which explains why mid-latitude cyclones are larger by an order of magnitude than inertial circle flow would be.
This pattern of deflection, and the direction of movement, is called Buys-Ballot's law. In the atmosphere, the pattern of flow is called a cyclone. In the Northern Hemisphere the direction of movement around a low-pressure area is anticlockwise. In the Southern Hemisphere, the direction of movement is clockwise because the rotational dynamics is a mirror image there. At high altitudes, outward-spreading air rotates in the opposite direction. Cyclones rarely form along the equator due to the weak Coriolis effect present in this region.
An air or water mass moving with speed formula_51 subject only to the Coriolis force travels in a circular trajectory called an 'inertial circle'. Since the force is directed at right angles to the motion of the particle, it moves with a constant speed around a circle whose radius formula_52 is given by:
where formula_54 is the Coriolis parameter formula_55, introduced above (where formula_56 is the latitude). The time taken for the mass to complete a full circle is therefore formula_57. The Coriolis parameter typically has a mid-latitude value of about 10−4 s−1; hence for a typical atmospheric speed of the radius is , with a period of about 17 hours. For an ocean current with a typical speed of , the radius of an inertial circle is . These inertial circles are clockwise in the Northern Hemisphere (where trajectories are bent to the right) and anticlockwise in the Southern Hemisphere.
If the rotating system is a parabolic turntable, then formula_54 is constant and the trajectories are exact circles. On a rotating planet, formula_54 varies with latitude and the paths of particles do not form exact circles. Since the parameter formula_54 varies as the sine of the latitude, the radius of the oscillations associated with a given speed are smallest at the poles (latitude = ±90°), and increase toward the equator.
The Coriolis effect strongly affects the large-scale oceanic and atmospheric circulation, leading to the formation of robust features like jet streams and western boundary currents. Such features are in geostrophic balance, meaning that the Coriolis and "pressure gradient" forces balance each other. Coriolis acceleration is also responsible for the propagation of many types of waves in the ocean and atmosphere, including Rossby waves and Kelvin waves. It is also instrumental in the so-called Ekman dynamics in the ocean, and in the establishment of the large-scale ocean flow pattern called the Sverdrup balance.
The practical impact of the "Coriolis effect" is mostly caused by the horizontal acceleration component produced by horizontal motion.
There are other components of the Coriolis effect. Westward-travelling objects are deflected downwards (feel heavier), while Eastward-travelling objects are deflected upwards (feel lighter). This is known as the Eötvös effect. This aspect of the Coriolis effect is greatest near the equator. The force produced by the Eötvös effect is similar to the horizontal component, but the much larger vertical forces due to gravity and pressure suggest that it is unimportant in the hydrostatic equilibrium. However, in the atmosphere, winds are associated with small deviations of pressure from the hydrostatic equilibrium. In the tropical atmosphere, the order of magnitude of the pressure deviations is so small that the contribution of the Eötvös effect to the pressure deviations is considerable.
In addition, objects travelling upwards ("i.e.", out) or downwards ("i.e.", in) are deflected to the west or east respectively. This effect is also the greatest near the equator. Since vertical movement is usually of limited extent and duration, the size of the effect is smaller and requires precise instruments to detect. For example, idealized numerical modeling studies suggest that this effect can directly affect tropical large-scale wind field by roughly 10% given long-duration (2 weeks or more) heating or cooling in the atmosphere. Moreover, in the case of large changes of momentum, such as a spacecraft being launched into orbit, the effect becomes significant. The fastest and most fuel-efficient path to orbit is a launch from the equator that curves to a directly eastward heading.
Imagine a train that travels through a frictionless railway line along the equator. Assume that, when in motion, it moves at the necessary speed to complete a trip around the world in one day (465 m/s). The Coriolis effect can be considered in three cases: when the train travels west, when it is at rest, and when it travels east. In each case, the Coriolis effect can be calculated from the rotating frame of reference on Earth first, and then checked against a fixed inertial frame. The image below illustrates the three cases as viewed by an observer at rest in a (near) inertial frame from a fixed point above the North Pole along the Earth's axis of rotation; the train is denoted by a few red pixels, fixed at the left side in the leftmost picture, moving in the others formula_61
This also explains why high speed projectiles that travel west are deflected down, and those that travel east are deflected up. This vertical component of the Coriolis effect is called the Eötvös effect.
The above example can be used to explain why the Eötvös effect starts diminishing when an object is travelling westward as its tangential speed increases above Earth's rotation (465 m/s). If the westward train in the above example increases speed, part of the force of gravity that pushes against the track accounts for the centripetal force needed to keep it in circular motion on the inertial frame. Once the train doubles its westward speed at 930 m/s that centripetal force becomes equal to the force the train experiences when it stops. From the inertial frame, in both cases it rotates at the same speed but in the opposite directions. Thus, the force is the same cancelling completely the Eötvös effect. Any object that moves westward at a speed above 930 m/s experiences an upward force instead. In the figure, the Eötvös effect is illustrated for a 10 kilogram object on the train at different speeds. The parabolic shape is because the centripetal force is proportional to the square of the tangential speed. On the inertial frame, the bottom of the parabola is centered at the origin. The offset is because this argument uses the Earth's rotating frame of reference. The graph shows that the Eötvös effect is not symmetrical, and that the resulting downward force experienced by an object that travels west at high velocity is less than the resulting upward force when it travels east at the same speed.
Contrary to popular misconception, bathtubs, toilets, and other water receptacles do not drain in opposite directions in the Northern and Southern Hemispheres. This is because the magnitude of the Coriolis force is negligible at this scale. Forces determined by the initial conditions of the water (e.g. the geometry of the drain, the geometry of the receptacle, pre-existing momentum of the water, etc.) are likely to be orders of magnitude greater than the Coriolis force and hence will determine the direction of water rotation, if any. For example, identical toilets flushed in both hemispheres drain in the same direction, and this direction is determined mostly by the shape of the toilet bowl.
In 1962, Prof. Ascher Shapiro performed an experiment at MIT to test the Coriolis force on a large basin of water, 2 metres across, with a small wooden cross above the plug hole to display the direction of rotation, covering it and waiting for at least 24 hours for the water to settle. Under these precise laboratory conditions, he demonstrated the effect and consistent counterclockwise rotation. Consistent clockwise rotation in the southern hemisphere was confirmed in 1965 by Dr Lloyd Trefethen at the University of Sydney. See the article "Bath-Tub Vortex" by Shapiro in the journal Nature (15 December 1962, vol. 196, p. 1080–1081) and the follow-up article "The Bath-Tub Vortex in the Southern Hemisphere" by Dr Trefethen in the same journal (4 September 1965, vol.207, p.1084-1085).
Shapiro: "Both schools of thought are in some sense correct. For the everyday observations of the kitchen sink and bath-tub variety, the direction of the vortex seems to vary in an unpredictable manner with the date, the time of day, and the particular household of the experimenter. But under well-controlled conditions of experimentation, the observer looking downward at a drain in the northern hemisphere will always see a counter-clockwise vortex, while one in the southern hemisphere will always see a clockwise vortex. In a properly designed experiment, the vortex is produced by Coriolis forces, which are counter-clockwise in the northern hemisphere."
Trefethen: "Clockwise rotation was observed in all five of the later tests that had settling times of 18 h or more."
Although there are many YouTube videos showing the common situation where the effect is not visible, versions of the delicate original experiment which verify the effect are rare.
The Coriolis force still affects the direction of the flow of water, but only minutely. Only if the water is so still that the effective rotation rate of the Earth is faster than that of the water relative to its container, and if externally applied torques (such as might be caused by flow over an uneven bottom surface) are small enough, the Coriolis effect may indeed determine the direction of the vortex. Without such careful preparation, the Coriolis effect is likely to be much smaller than various other influences on drain direction such as any residual rotation of the water and the geometry of the container. Despite this, the idea that toilets and bathtubs drain differently in the Northern and Southern Hemispheres has been popularized by several television programs and films, including "Escape Plan", "Wedding Crashers", "The Simpsons" episode "Bart vs. Australia", "Pole to Pole", and "The X-Files" episode "Die Hand Die Verletzt". Several science broadcasts and publications, including at least one college-level physics textbook, have also stated this.
The formation of a spiral vortex over the plug hole may be explained by the conservation of angular momentum: The radius of rotation decreases as water approaches the plug hole, so the rate of rotation increases, for the same reason that an ice skater's rate of spin increases as they pull their arms in. Any rotation around the plug hole that is initially present accelerates as water moves inward.
A letter to the editor by Richard Hake in the American Journal of Physics explained how simpler versions of the experiments of Shapiro and Trefethen can be carried out on a merry-go-round.
The Coriolis force is important in external ballistics for calculating the trajectories of very long-range artillery shells. The most famous historical example was the Paris gun, used by the Germans during World War I to bombard Paris from a range of about . The Coriolis force minutely changes the trajectory of a bullet, affecting accuracy at extremely long distances. It is adjusted for by accurate long-distance shooters, such as snipers. At the latitude of Sacramento a 1000-yard shot would be deflected 2.8 inches to the right. There is also a vertical component, explained in the Eötvös effect section above, which causes westward shots to hit low, and eastward shots to hit high.
The effects of the Coriolis force on ballistic trajectories should not be confused with the curvature of the paths of missiles, satellites, and similar objects when the paths are plotted on two-dimensional (flat) maps, such as the Mercator projection. The projections of the three-dimensional curved surface of the Earth to a two-dimensional surface (the map) necessarily results in distorted features. The apparent curvature of the path is a consequence of the sphericity of the Earth and would occur even in a non-rotating frame.
To demonstrate the Coriolis effect, a parabolic turntable can be used.
On a flat turntable, the inertia of a co-rotating object forces it off the edge. However, if the turntable surface has the correct paraboloid (parabolic bowl) shape (see the figure) and rotates at the corresponding rate, the force components shown in the figure make the component of gravity tangential to the bowl surface exactly equal to the centripetal force necessary to keep the object rotating at its velocity and radius of curvature (assuming no friction). (See .) This carefully contoured surface allows the Coriolis force to be displayed in isolation.
Discs cut from cylinders of dry ice can be used as pucks, moving around almost frictionlessly over the surface of the parabolic turntable, allowing effects of Coriolis on dynamic phenomena to show themselves. To get a view of the motions as seen from the reference frame rotating with the turntable, a video camera is attached to the turntable so as to co-rotate with the turntable, with results as shown in the figure. In the left panel of the figure, which is the viewpoint of a stationary observer, the gravitational force in the inertial frame pulling the object toward the center (bottom ) of the dish is proportional to the distance of the object from the center. A centripetal force of this form causes the elliptical motion. In the right panel, which shows the viewpoint of the rotating frame, the inward gravitational force in the rotating frame (the same force as in the inertial frame) is balanced by the outward centrifugal force (present only in the rotating frame). With these two forces balanced, in the rotating frame the only unbalanced force is Coriolis (also present only in the rotating frame), and the motion is an "inertial circle". Analysis and observation of circular motion in the rotating frame is a simplification compared with analysis and observation of elliptical motion in the inertial frame.
Because this reference frame rotates several times a minute rather than only once a day like the Earth, the Coriolis acceleration produced is many times larger and so easier to observe on small time and spatial scales than is the Coriolis acceleration caused by the rotation of the Earth.
In a manner of speaking, the Earth is analogous to such a turntable. The rotation has caused the planet to settle on a spheroid shape, such that the normal force, the gravitational force and the centrifugal force exactly balance each other on a "horizontal" surface. (See equatorial bulge.)
The Coriolis effect caused by the rotation of the Earth can be seen indirectly through the motion of a Foucault pendulum.
A practical application of the Coriolis effect is the mass flow meter, an instrument that measures the mass flow rate and density of a fluid flowing through a tube. The operating principle involves inducing a vibration of the tube through which the fluid passes. The vibration, though not completely circular, provides the rotating reference frame that gives rise to the Coriolis effect. While specific methods vary according to the design of the flow meter, sensors monitor and analyze changes in frequency, phase shift, and amplitude of the vibrating flow tubes. The changes observed represent the mass flow rate and density of the fluid.
In polyatomic molecules, the molecule motion can be described by a rigid body rotation and internal vibration of atoms about their equilibrium position. As a result of the vibrations of the atoms, the atoms are in motion relative to the rotating coordinate system of the molecule. Coriolis effects are therefore present, and make the atoms move in a direction perpendicular to the original oscillations. This leads to a mixing in molecular spectra between the rotational and vibrational levels, from which Coriolis coupling constants can be determined.
When an external torque is applied to a spinning gyroscope along an axis that is at right angles to the spin axis, the rim velocity that is associated with the spin becomes radially directed in relation to the external torque axis. This causes a Torque Induced force to act on the rim in such a way as to tilt the gyroscope at right angles to the direction that the external torque would have tilted it. This tendency has the effect of keeping spinning bodies in their rotational frame.
Flies (Diptera) and some moths (Lepidoptera) exploit the Coriolis effect in flight with specialized appendages and organs that relay information about the angular velocity of their bodies.
Coriolis forces resulting from linear motion of these appendages are detected within the rotating frame of reference of the insects' bodies. In the case of flies, their specialized appendages are dumbbell shaped organs located just behind their wings called "halteres".
The fly's halteres oscillate in a plane at the same beat frequency as the main wings so that any body rotation results in lateral deviation of the halteres from their plane of motion.
In moths, their antennae are known to be responsible for the "sensing" of Coriolis forces in the similar manner as with the halteres in flies. In both flies and moths, a collection of mechanosensors at the base of the appendage are sensitive to deviations at the beat frequency, correlating to rotation in the pitch and roll planes, and at twice the beat frequency, correlating to rotation in the yaw plane.
In astronomy, Lagrangian points are five positions in the orbital plane of two large orbiting bodies where a small object affected only by gravity can maintain a stable position relative to the two large bodies. The first three Lagrangian points (L1, L2, L3) lie along the line connecting the two large bodies, while the last two points (L4 and L5) each form an equilateral triangle with the two large bodies. The L4 and L5 points, although they correspond to maxima of the effective potential in the coordinate frame that rotates with the two large bodies, are stable due to the Coriolis effect. The stability can result in orbits around just L4 or L5, known as tadpole orbits, where trojans can be found. It can also result in orbits that encircle L3, L4, and L5, known as horseshoe orbits. | https://en.wikipedia.org/wiki?curid=7783 |
Challenger Deep
The Challenger Deep is the deepest known point in the Earth's seabed hydrosphere (the oceans), with a depth of by direct measurement from deep-diving submersibles, remotely operated vehicles and benthic landers and (sometimes) slightly more by sonar bathymetry.
The Challenger Deep is located in the Western Pacific Ocean, at the southern end of the Mariana Trench near the Mariana Islands group. According to the August 2011 version of the GEBCO Gazetteer of Undersea Feature Names, the Challenger Deep is ± deep at .
This location is in the ocean territory of the Federated States of Micronesia.
The depression is named after the British Royal Navy survey ship , whose expedition of 1872–1876 made the first recordings of its depth. The high water pressure at this depth makes designing and operating exploratory craft difficult. The first descent by any vehicle was by the manned bathyscaphe "Trieste" in January 1960; unmanned visits followed in 1996, 1998 and 2009. In March 2012 a manned solo descent was made by film director James Cameron in the deep-submergence vehicle "Deepsea Challenger". Between 28 April and 4 May 2019, the "DSV Limiting Factor" completed four manned dives to the bottom of Challenger Deep.
The Challenger Deep is a relatively small slot-shaped depression in the bottom of a considerably larger crescent-shaped oceanic trench, which itself is an unusually deep feature in the ocean floor. The Challenger Deep consists of three basins, each long, wide, and over in depth, oriented in echelon from west to east, separated by mounds between the basins higher. The three basins feature extends about west to east if measured at the isobath. Both the western and eastern basins have recorded depths (by sonar bathymetry) in excess of , while the center basin is slightly shallower. The closest land to the Challenger Deep is Fais Island (one of the outer islands of Yap), southwest, and Guam, to the northeast.
Over many years, the search for, and investigation of, the location of the maximum depth of the world's oceans has involved many different vessels, and continues into the twenty-first century.
The accuracy of determining geographical location, and the beamwidth of (multibeam) echosounder systems, limits the horizontal and vertical bathymetric sensor resolution hydrographers can obtain from onsite data. This is especially important when sounding in deep water, as the resulting footprint of an acoustic pulse gets large once it reaches a distant sea floor. Further, sonar operation is affected by variations in sound speed, particularly in the vertical plane. The speed is determined by the water's bulk modulus, mass, and density. The bulk modulus is affected by temperature, pressure, and dissolved impurities (usually salinity).
1875 – HMS "Challenger" –– In 1875, during her transit from the Admiralty Islands to Yokohama, the three-masted sailing corvette HMS ""Challenger" "attempted to make landfall at Guam, but was set to the west by “baffling winds” preventing them from “visiting either the Carolines or the Ladrones.” "These winds pushed her track to the west, across the 35-mile-long depression which, 85-years later, would achieve prominence as the Challenger Deep. Even more amazing, one of her thirteen sampling stations on that 2,300 nm track to Japan was within fifteen miles of the deepest depression in the world’s oceans."
On 23 March 1875, at sample station number #225, HMS "Challenger" recorded the bottom at deep, (the deepest sounding of her three-plus-year eastward circumnavigation of the Earth) at —and confirmed it with a second sounding at the same location. Depth soundings were by Baillie-weighted marked rope, and geographical locations were determined by celestial navigation (to an estimated accuracy of two nautical miles).
The serendipitous discovery of Earth’s deepest depression by history’s first major scientific expedition devoted entirely to the emerging science of oceanography, was incredibly good fortune, and especially notable when compared to the Earth’s third deepest site (the Sirena Deep only 150 nautical miles east of the Challenger Deep), which would remain undiscovered for another 122 years.
1951 – SV HMS "Challenger II" –– Seventy-five years later, the 1,140-ton British survey vessel HMS "Challenger II", on her three-year westward circumnavigation of Earth, investigated the extreme depths southwest of Guam reported in 1875 by her predecessor, HMS "Challenger". On her southbound track from Japan to New Zealand (May–July 1951), "Challenger II" conducted a survey of “the Marianas Trench between Guam and Ulithi ,” using seismic-sized bomb-soundings and recorded a maximum depth of . The depth was beyond "Challenger II" echo sounder capability to verify, so they resorted to using a taut wire with “140-lbs of scrap iron”, and documented a depth of .
In New Zealand, the "Challenger II" team gained the assistance of the Royal New Zealand Dockyard, “who managed to boost the echo sounder to record at the greatest depths.” They returned to the “Marianas Deep” (sic) in October 1951. Using their newly improved echo sounder, they ran survey lines at right angles to the axis of the trench and discovered “a considerable area of a depth greater than ” -- later identified as the Challenger Deep’s "western" basin. The greatest depth recorded was , at . Navigational accuracy of several hundred meters was attained by celestial navigation and LORAN-A. Note that the term “Challenger Deep” came into use after this 1951-52 "Challenger" circumnavigation, and commemorates both British ships of that name involved with the discovery of the deepest basin of the world’s oceans.
1957–1958 – RV "Vityaz" –– In August 1957, the 3,248-ton Vernadsky Institute of Geochemistry research vessel "Vityaz" recorded a maximum depth of ± at in the western basin of the Challenger Deep during a brief transit of the area on Cruise #25. She returned in 1958, Cruise #27, to conduct a detailed single beam bathymetry survey involving over a dozen transects of the Deep, with extensive examination of the western basin and a quick peek into the eastern basin. Fisher records a total of three "Vityaz" sounding locations on Fig.2 "Trenches" (1963), one within yards of the 142°11.5' E location, and a third at , all with ± depth. The depths were considered statistical outliers, and a depth greater than 11,000 m has never been proven. Taira reports that if "Vityaz" depth was corrected with the same methodology used by the Japanese RV "Hakuho Maru" expedition of December 1992, it would be presented as ±, as opposed to modern depths from multibeam echosounder systems greater than with the NOAA accepted maximum of ± in the western basin.
1959 – RV "Stranger" –– The first definitive verification of both depth and location of the Challenger Deep (western basin) was determined by Dr. R. L. Fisher from the Scripps Institution of Oceanography, aboard the 325-ton research vessel "Stranger". Using explosive soundings, they recorded ± at/near in July 1959. "Stranger" used celestial and LORAN-C for navigation. LORAN-C navigation provided geographical accuracy of or better.
According to another source RV "Stranger" using bomb-sounding surveyed a maximum depth of ± at .
Discrepancies between the geographical location (lat/long) of "Stranger" deepest depths and those from earlier expeditions ("Challenger II" 1951; "Vityaz" 1957 & 1958) “are probably due to uncertainties in fixing the ships’ positions.”
"Stranger" north-south zig-zag survey passed well to the east of the eastern basin southbound, and well to the west of the eastern basin northbound, thus failed to discover the eastern basin of the Challenger Deep. The maximum depth measured near longitude 142°30’E was ±, about 10 kms west of the eastern basin’s deepest point. This was an important gap in information, as the eastern basin was later reported as deeper than the other two basins.
"Stranger" crossed the center basin twice, measuring a maximum depth of ± in the vicinity of 142°22’E. At the western end of the central basin (approximately 142°18’E), they recorded a depth of ±.
The western basin received four transects by "Stranger", recording depths of ± toward the central basin, near where "Trieste" dove in 1960 (vicinity , and where "Challenger II", in 1950, recorded ±. At the far western end of the "western" basin (about 142°11’E), the "Stranger" recorded ±, some 6 km south of the location where "Vityaz" recorded ± in 1957-1958. Fisher stated: “…differences in the "Vitiaz" (sic) and "Stranger"-"Challenger II" depths can be attributed to the [sound] velocity correction function used…”
After investigating the Challenger Deep, "Stranger" proceeded to the Philippine Trench and transected the trench over twenty times in August 1959, finding a maximum depth of ±, and thus established that the Challenger Deep was about deeper than the Philippine Trench. The 1959 "Stranger" surveys of the Challenger Deep and of the Philippine Trench informed the U.S. Navy as to the appropriate site for "Trieste" record dive in 1960.
1962 – RV "Spenser F. Baird" –– The "Proa Expedition, Leg 2", returned Fisher to the Challenger Deep on 12–13 April 1962 aboard the Scripps research vessel "Spencer F. Baird" (formerly the steel-hulled US Army large tug "LT-581") and employed a Precision Depth Recorder (PDR) to verify the extreme depths previously reported. They recorded a maximum depth of (location not available). Additionally, at location “H-4” in the Challenger Deep, the expedition cast three taut-wire soundings: on 12 April, the first cast was to 5078 fathoms (corrected for wire angle) at in the central basin. (Up until 1965, US research vessels recorded soundings in fathoms.) The second cast, also on 12 April, was to 5000+ fathoms at in the central basin. On 13 April, the final cast recorded 5297 fathoms (corrected for wire angle) at (the western basin). They were chased off by a hurricane after only two days on-site. Once again, Fisher entirely missed the eastern basin of the Challenger Deep, which later proved to contain the deepest depths.
1975–1980 – RV "Thomas Washington" –– The Scripps Institution of Oceanography deployed the 1,490-ton Navy-owned, civilian-crewed research vessel "Thomas Washington" (AGOR-10) to the Mariana Trench on several expeditions from 1975 to 1986. The first of these was the "Eurydice Expedition, Leg 8" which brought Fisher back to the Challenger Deep’s western basin from 28–31 March 1975. "Thomas Washington" established geodetic positioning by (SATNAV) with Autolog Gyro and EM Log. Bathymetrics were by a 12 kHz Precision Depth Recorder (PDR) with a single 60° beam. They mapped one, “possibly two,” axial basins with a depth of ±. Five dredges were hauled 27–31 March, all into or slightly north of the deepest depths of the western basin. Fisher noted that this survey of the Challenger Deep (western basin) had "...provided nothing to support and much to refute recent claims of depths there greater than ±." While Fisher missed the eastern basin of the Challenger Deep (for the third time), he did report a deep depression about 150 nautical miles east of the western basin. The 25 March dredge haul at encountered , which pre-shadowed by 22 years the discovery of HMRG Deep/Sirena Deep in 1997. The deepest waters of the HMRG Deep/Serina Deep at ± are centered at/near , approximately 2.65 km from Fisher's 25 March 1975 dredge haul.
On Scripps Institution of Oceanography's "INDOPAC Expedition Leg 3", the chief scientist, Dr. Joseph L. Reid, and oceanographer Arnold W. Mantyla made a hydrocast of a free vehicle (a special-purpose benthic lander (or "baited camera") for measurements of water temperature and salinity) on 27 May 1976 into the western basin of the Challenger Deep, "Station 21," at at about depth. On "INDOPAC Expedition Leg 9", under chief scientist A. Aristides Yayanos, "Thomas Washington" spent nine days from 13–21 January 1977 conducting an extensive and detailed investigation of the Challenger Deep, mainly with biological objectives. “Echo soundings were carried out primarily with a 3.5 kHz single-beam system, with a 12 kHz echosounder operated in addition some of the time,” (the 12 kHz system was activated for testing on 16 January). A benthic lander was put into the western basin (, on 13 January, bottoming at and recovered 50 hours later in damaged condition. Quickly repaired, it was again put down on the 15th to depth at . It was recovered on the 17th with excellent photography of amphipods (shrimp) from the Challenger Deep’s western basin. The benthic lander was put down for the third and last time on the 17th, at , in the central basin at a depth of . The benthic lander was not recovered and may remain on the bottom in the vicinity of . Free traps and pressure-retaining traps were put down at eight location from 13 to 19 January into the western basin, at depths ranging from to . Both the free traps and the pressure-retaining traps brought up good sample amphipods for study. While the ship briefly visited the area of the eastern basin, the expedition did not recognize it as potentially the deepest of the three Challenger Deep basins.
"Thomas Washington" returned briefly to the Challenger Deep on 17–19 October 1978 during "Mariana Expedition Leg 5" under chief scientist James W. Hawkins. The ship tracked to the south and west of the eastern basin, and recorded depths between to . Another miss. On "Mariana Expedition Leg 8", under chief scientist Yayanos, "Thomas Washington" was again involved, from 12–21 December 1978, with an intensive biological study of the western and central basins of the Challenger Deep. Fourteen traps and pressure-retaining traps were put down to depths ranging from to meters, the greatest depth was at . All of the 10,900-plus m recordings were in the western basin. The depth was furthest east at 142°26.4’ E (in the central basin), about 17 km west of the eastern basin. Again, focused efforts on the known areas of extreme depths (the western and central basins) was so tight that the eastern basin again was missed by this expedition.
From 20 to 30 November 1980, "Thomas Washington" was on site at the western basin of the Challenger Deep, as part of "Rama Expedition Leg 7", again with chief-scientist Dr. A.A. Yayanos. Yayanos directed "Thomas Washington" in arguably the most extensive and wide-ranging of all single-beam bathymetric examinations of the Challenger Deep ever undertaken, with dozens of transits of the western basin, and ranging far into the backarc of the Challenger Deep (northward), with significant excursions into the Pacific Plate (southward) and along the trench axis to the east. They hauled eight dredges in the western basin to depths ranging from to ; and between hauls, cast thirteen free vertical traps. The dredging and traps were for biological investigation of the bottom. In the first successful retrieval of a live animal from the Challenger Deep, on 21 November 1980 in the western basin at , Yayanos recovered a live amphipod from about 10,900 meters depth with a pressurized trap. Once again, other than a brief look into the eastern basin, all bathymetric and biological investigations were into the western basin.
1976–1977 – RV "Kana Keoki" –– On Leg 3 of the Hawaii Institute of Geophysics' (HIG) expedition 76010303, the 156-foot research vessel "Kana Keoki" departed Guam primarily for a seismic investigation of the Challenger Deep area, under chief scientist Donald M. Hussong. The ship was equipped with air guns (for seismic reflection soundings deep into the Earth's mantle), magnetometer, gravimeter, 3.5-kHz and 12-kHz sonar transducers, and precision depth recorders. They ran the Deep from east to west, collecting single beam bathymetry, magnetic and gravity measurements, and employed the air guns along the trench axis, and well into the backarc and forearc, from 13–15 March 1976. Thence they proceeded south to the Ontong Java Plateau. All three deep basins of the Challenger Deep were covered, but "Kana Keoki" recorded a maximum depth of . Seismic information developed from this survey was instrumental in gaining an understanding of the subduction of the Pacific Plate under the Philippine Sea Plate. In 1977, "Kana Keoki" returned to the Challenger Deep area for wider coverage of the forearc and backarc.
1984 – SV "Takuyo" –– The Hydrographic Department, Maritime Safety Agency, Japan (JHOD) deployed the newly commissioned 2,600-ton survey vessel "Takuyo" (HL 02) to the Challenger Deep 17–19 February 1984. "Takuyo" was the first Japanese ship to be equipped with the new narrowbeam SeaBeam multi-beam sonar echosounder, and was the first survey ship with multi-beam capability to survey the Challenger Deep. The system was so new that JHOD had to develop their own software for drawing bathymetric charts based on the SeaBeam digital data. In just three days, they tracked 500 miles of sounding lines, and covered about 140 km² of the Challenger Deep with multibeam ensonification. Under chief scientist Hideo Nishida, they used CTD temperature and salinity data from the top of the water column to correct depth measurements, and later conferred with Scripps Institution of Oceanography (including Fisher), and other GEBCO experts to confirm their depth correction methodology. They employed a combination of NAVSAT, LORAN-C and OMEGA systems for geodetic positioning with accuracy better than . The deepest location recorded was ± at ; for the first time documenting the eastern basin as the deepest of the three en echelon pools. In 1993, GEBCO recognized the ± report as the deepest depth of the world’s oceans. Technological advances such as improved multi-beam sonar would be the driving force in uncovering the mysteries of the Challenger Deep into the future.
1986 – RV "Thomas Washington" –– The Scripps research vessel "Thomas Washington" returned to the Challenger Deep in 1986 during the "Papatua Expedition, Leg 8", mounting one of the first commercial multi-beam echosounders capable of reaching into the deepest trenches, i.e. the 16-beam Seabeam “Classic”. This allowed chief scientist Yayanos an opportunity to transit the Challenger Deep with the most modern depth-sounding equipment available. During the pre-midnight hours of 21 April 1986, the multibeam echosounder produced a map of the Challenger Deep bottom with a swath of about 5–7 miles wide. The maximum depth recorded was (location of depth is not available). Yayanos noted: “The lasting impression from this cruise comes from the thoughts of the revolutionary things that Seabeam data can do for deep biology.”
1988 – RV "Moana Wave" –– On 22 August 1988, the U.S. Navy-owned 1,000-ton research vessel "Moana Wave" (AGOR-22), operated by the Hawaii Institute of Geophysics (HIG), University of Hawaii, under the direction of chief scientist Robert C. Thunell from the University of South Carolina, transited northwesterly across the central basin of the Challenger Deep, conducting a single-beam bathymetry track by their 3.5 kHz narrow (30-degs) beam echosounder with a Precision Depth Recorder. In addition to sonar bathymetry, they took 44 gravity cores and 21 box cores of bottom sediments. The deepest echosoundings recorded were 10,656 metres (34,961 ft) to 10,916 metres (35,814 ft), with the greatest depth at 11°22′N 142°25′E in the central basin. This was the first indication that all three basins contained depths in excess of 10,900 metres (35,800 ft).
1992 – RV "Hakuhō Maru" –– The 3,987-ton Japanese research vessel "Hakuhō Maru", an Ocean Research Institute - University of Tokyo sponsored ship, on cruise KH-92-5 cast three Sea-Bird SBE-9 ultra-deep CTD (conductivity-temperature-depth) profilers in a transverse line across the Challenger Deep on 1 December 1992. The center CTD was located at , in the eastern basin, at by the SeaBeam depth recorder and by the CTD. The other two CTDs were cast 19.9 km to the north and 16.1 km to the south. "Hakuhō Maru" was equipped with a narrow beam SeaBeam 500 multi-beam echosounder for depth determination, and had an Auto-Nav system with inputs from NAVSAT/NNSS, GPS, Doppler Log, EM log and track display, with a geodetic positioning accuracy approaching . When conducting CTD operations in the Challenger deep, they used the SeaBeam as a single beam depth recorder. At the corrected depth was , and at the depth was ; both in the "eastern" basin. This may demonstrate that the basins might not be flat sedimentary pools but rather undulate with a difference of or more. Taira revealed, “We considered that a trough deeper that "Vitiaz" record by was detected. There is a possibly that a depth exceeding with a horizontal scale less that the beam width of measurements exists in the Challenger Deep. Since each SeaBeam 2.7 degree beam width sonar ping expands to cover a circular area about in diameter at depth, dips in the bottom that are less than that size would be difficult to detect from a sonar-emitting platform seven miles above.
1996 – RV "Yokosuka" –– For most of 1995 and into 1996, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) employed the 4,439-ton Research Vessel vessel "Yokosuka" to conduct the testing and workup of the 11,000 meter remotely-operated vehicle (ROV) "Kaikō", and the 6,500 meter ROV "Shinkai." It was not until February 1996, during "Yokosuka" cruise Y96-06, that "Kaikō" was ready for its first full depth dives. On this cruise, JAMSTEC established an area of the Challenger Deep (11°10’N to 11°30’ N, by 141°50’ E to 143°00’ Ewhich later was recognized as containing three separate pools/basins en echelon, each with depths in excess of ) toward which JAMSTEC expeditions would concentrate their investigations for the next two decades. The Yokosuka employed a 151-beam SeaBeam 2112 12-kHz multibeam echosounder, allowing search swaths 12–15 km in width at depth. The depth accuracy of "Yokosuka" Seabeam was about 0.1% of water depth (i.e. ± for depth). The ship’s dual GPS systems attained geodetic positioning within double digit meter ( or better) accuracy.
1998, 1999 and 2002 – RV "Kairei" –– Cruise KR98-01 sent JAMSTEC's two-year-old the 4,517-ton Deep Sea Research Vessel RV "Kairei" south for a quick but thorough depth survey of the Challenger Deep, 11–13 January 1998, under chief scientist Kantaro Fujioka. Tracking largely along the trench axis of 070°-250° they made five 80-km bathymetric survey tracks, spaced about 15-km apart, overlapping their SeaBeam 2112-004 (which now allowed sub-bottom profiling penetrating as much as 75 m below the bottom) while gaining gravity and magnetic data covering the entire Challenger Deep: western, central, and eastern basins.
"Kairei" returned in May 1998, cruise KR98-05, with ROV "Kaikō", under the direction of chief scientist Jun Hashimoto with both geophysical and biological goals. Their bathymetric survey from 14–26 May was the most intensive and thorough depth and seismic survey of the Challenger Deep performed to date. Each evening, "Kaikō" deployed for about four hours of bottom time for biological-related sampling, plus about seven hours of vertical transit time. When "Kaikō" was onboard for servicing, "Kairei" conducted bathymetric surveys and observations. "Kairei" gridded a survey area about 130 km N-S by 110 km E-W. "Kaikō" made six dives (#71 - #75) all to the same location, (11°20.8' N, 142°12.35' E), near the bottom contour line in the western basin.
The regional bathymetric map made from the data obtained in 1998 shows that the greatest depths in the eastern, central, and western depressions are ±, ±, and ±, respectively, making the eastern depression the deepest of the three.
In 1999, "Kairei" revisited the Challenger Deep during cruise KR99-06. The results of the 1998-1999 surveys include the first recognition that the Challenger Deep consists of three “right-stepping en echelon individual basins bounded by the depth contour line. The size of [each of] the deeps are almost identical, 14-20 km long, 4 km wide.” They concluded with the proposal “that these three individual elongated deeps constitute the ‘Challenger Deep’, and [we] identify them as the East, Central and West Deep. The deepest depth we obtained during the swath mapping is in the West Deep (11°20.34’ N, 142°13.20 E).” The depth was “obtained during swath mapping... confirmed in both N-S and E-W swaths.” Speed of sound corrections were from XBT to , and CTD below .
The cross track survey of the 1999 "Kairei" cruise shows that the greatest depths in the eastern, central, and western depressions are ±, ±, and ±, respectively, which supports the results of the previous survey.
In 2002 "Kairei" revisited the Challenger Deep 16–25 October 2002, as cruise KR02-13 (a cooperative Japan-US-South Korea research program) with chief scientist Jun Hashimoto in charge; again with Kazuyoshi Hirata managing the ROV "Kaikō" team. On this survey, the size of each of the three basins was refined to 6–10 km long by about 2 km wide and in excess of deep. In marked contrast to the "Kairei" surveys of 1998 and 1999, the detailed survey in 2002 determined that the deepest point in the Challenger Deep is located in the eastern basin around , with a depth of ±, located about southeast of the deepest site determined by the survey vessel "Takuyo" in 1984. The 2002 surveys of both the western and eastern basins were tight, with especially meticulous cross-gridding of the eastern basin with ten parallel tracks N-S and E-W less than 250 meters apart. On the morning of 17 October, ROV "Kaikō" dive #272 began and recovered over 33 hours later, with the ROV working at the bottom of the western basin for 26 hours (vicinity of 11°20.148' N, 142°11.774 E at ). Five "Kaikō" dives followed on a daily basis into the same area to service benthic landers and other scientific equipment, with dive #277 recovered on 25 October. Traps brought up large numbers of amphipods (sea fleas), and cameras recorded holothurians (sea cucumbers), White polychaetes (bristle worms), tube worms, and other biological species. During its 1998, 1999 surveys, "Kairei" was equipped with a GPS satellite-based radionavigation system. The United States government lifted the GPS selective availability in 2000, so during its 2002 survey, "Kairei" had access to non-degraded GPS positional services and achieved single digit meter accuracy in geodetic positioning.
2001 – RV "Melville" –– The 2.516-ton research vessel "Melville" at the time operated by the Scripps Institution of Oceanography took the Cook Expedition, Leg 6 with chief scientist Patricia Fryer of the University of Hawaii from Guam on 10 February 2001 to the Challenger Deep for a survey titled “Subduction Factory Studies in the Southern Mariana,” including HMR-1 sonar mapping, magnetics, gravity measurements, and dredging in the Mariana arc region. They covered all three basins, then tracked -long lines of bathymetry East-West, stepping northward from the Challenger Deep in sidesteps, covering more than north into the backarc with overlapping swaths from their SeaBeam 2000 12-kHz multi-beam echosounder and MR1 towed system. They also gathered magnetic and gravity information, but no seismic data. Their primary survey instrument was the MR1 towed sonar, a shallow-towed 11/12-kHz bathymetric sidescan sonar developed and operated by the Hawaii Mapping Research Group (HMRG), a research and operational group within University of Hawaii’s School of Ocean and Earth Science and Technology (SOEST) and the Hawaii Institute of Geophysics and Planetology (HIGP). The MR1 is full-ocean-depth capable, and provides both bathymetry and sidescan data.
Leg 7 of the Cook Expedition continued the MR-1 survey of the Mariana Trench backarc from 4 March to 12 April 2001 under chief scientist Sherman Bloomer of Oregon State University.
2009 – RV "Kilo Moana" –– In May/June 2009 the US Navy-owned 3,064-ton twin-hulled research vessel "Kilo Moana" (T-AGOR 26) was sent to the Challenger Deep area to conduct research. "Kilo Moana" is civilian-manned and operated by SOEST. It is equipped with two multibeam echosounders with sub-bottom profiler add-ons (the 191-beam 12 kHz Kongsberg Simrad EM120 with SBP-1200, capable of accuracies of 0.2%-0.5% of water depth across the entire swath), gravimeter, and magnetometer. The EM-120 uses 1 by 1 degree sonar-emissions at the sea surface. Each 1 degree beam width sonar ping expands to cover a circular area about in diameter at depth. Whilst mapping the Challenger Deep the sonar equipment indicated a maximum depth of at an undisclosed position. Navigation equipment includes the Applanix POS MV320 V4, rated at accuracies of ½-to-2 meters. RV "Kilo Moana" was also used as the support ship of the hybrid remotely operated underwater vehicle (HROV) "Nereus" that dove three times to the Challenger Deep bottom during the May/June 2009 cruise and did not confirm the sonar established maximum depth by its support ship.
2009 – RV "Yokosuka" – Cruise YK09-08 brought the JAMSTEC 4,429-ton research vessel "Yokosuka" back to the Mariana Trough and to the Challenger Deep June-July 2009. Their mission was a two-part program: surveying three hydrothermal vent sites in the southern Mariana Trough backarc basin near 12°57’N, 143°37’E about 130 nmi northeast of the central basin of the Challenger Deep, using the autonomous underwater vehicle "Urashima". AUV "Urashima" dives #90-94, were to a maximum depth of 3500 meters, and were successful in surveying all three sites with a Reson SEABAT7125AUV multibeam echosounder for bathymetry, and multiple water testers to detect and map trace elements spewed into the water from hydrothermal vents, white smokers, and hot spots. Kyoko OKINO from the Ocean Research Institute, University of Tokyo, was principal investigator for this aspect of the cruise.
The second goal of the cruise was to deploy a new “10K free fall camera system” called "Ashura", to sample sediments and biologics at the bottom of the Challenger Deep. The principal investigator at the Challenger Deep was Taishi Tsubouchi of JAMSTEC. The lander "Ashura" made two descents: on the first, 6 July 2009, "Ashura" bottomed at at . The second descent (on 10 July 2009) was to at . The 270 kg "Ashura" was equipped with multiple baited traps, a HTDV video camera, and devices to recover sediment, water, and biological samples (mostly amphipods at the bait, and bacteria and fungus from the sediment and water samples).
2010 – USNS "Sumner" – On 7 October 2010, further sonar mapping of the Challenger Deep area was conducted by the US Center for Coastal & Ocean Mapping/Joint Hydrographic Center (CCOM/JHC) aboard the 4.762-ton "Sumner". The results were reported in December 2011 at the annual American Geophysical Union fall meeting. Using a Kongsberg Maritime EM 122 multi-beam echosounder system coupled to positioning equipment that can determine latitude and longitude up to accuracy, from thousands of individual soundings around the deepest part the CCOM/JHC team preliminary determined that the Challenger Deep has a maximum depth of at , with an estimated vertical uncertainty of ± at two standard deviations (i.e. ≈ 95.4%) confidence level. A secondary deep with a depth of was located at approximately to the east at in the eastern basin of the Challenger Deep.
2010 – RV "Yokosuka" -- JAMSTEC returned "Yokosuka" to the Challenger Deep with cruise YK10-16, 21–28 November 2010. The chief scientist of this joint Japanese-Danish expedition was Hiroshi Kitazato of the Institute of Biogeosciences, JAMSTEC. The cruise was titled "Biogeosciences at the Challenger Deep: relict organisms and their relations to biogeochemical cycles." The Japanese teams made five deployments of their 11,000-meter camera system (three to 6,000 meters – two into the central basin of the Challenger Deep) which returned with 15 sediment cores, video records and 140 scavenging amphipod specimens. The Danish Ultra Deep Lander System was employed by Ronnie Glud et al on four casts, two into the central basin of the Challenger Deep and two to 6,000 m some 34 nmi west of the central basin. The deepest depth recorded was on 28 November 2010 – camera cast CS5 – }, at a corrected depth of (the central basin).
2013 – RV "Yokosuka" -- With JAMSTEC Cruises YK13-09 & YK13-12, "Yokosuka" hosted chief scientist Hidetaka Nomaki for a trip to New Zealand waters (YK13-09), with the return cruise identified as YK13-12. The project name was QUELLE2013; and the cruise title was: “In situ experimental & sampling study to understand abyssal biodiversity and biogeochemical cycles.” They spent one day on the return trip at the Challenger Deep to obtain DNA/RNA on the large amphipods inhabiting the Deep ("Hirondellea gigas"). Hideki Kobayashi (Biogeos, JAMSTEC) and team deployed a benthic lander on 23 November 2013 with eleven baited traps (three bald, five covered by insulating materials, and three automatically sealed after nine hours) into the central basin of the Challenger Deep at , depth . After an eight-hour, 46-minute stay at the bottom, they recovered some 90 individual "Hirondellea gigas".
2014 – RV "Kairei" –– JAMSTEC deployed "Kairei" to the Challenger Deep again 11-17 January 2014, under the leadership of chief scientist Takuro Nunora. The cruise identifier was KR14-01, titled: “Trench biosphere expedition for the Challenger Deep, Mariana Trench”. The expedition sampled at six stations transecting the central basin, with only two deployments of the “11-K camera system” lander for sediment cores and water samples to “Station C” at the deepest depth, i.e. , at . The other stations were investigated with the “Multi-core” lander, both to the backarc northward, and to the Pacific Plate southward. The 11,000-meter capable crawler-driven ROV "ABIMSO" was sent to 7,646 m depth about 20 nmi due north of the central basin (ABISMO dive #21) specifically to identify possible hydrothermal activity on the north slope of the Challenger Deep, as suggested by findings from "Kairei" cruise KR08-05 in 2008. "AMISMO" dives #20 and #22 were to 7,900 meters about 15 nmi north of the deepest waters of the central basin. Italian researchers under the leadership of Laura Carugati from the Polytechnic University of Marche, Italy (UNIVPM) were investigating the dynamics in virus/prokaryotes interactions in the Mariana Trench.
2014 – RV "Falkor" –– From 16-19 December 2014, the Schmidt Ocean Institute's 2,024-ton research vessel "Falkor", under chief scientist Douglas Bartlett from the Scripps Institution of Oceanography, deployed four different untethered instruments into the Challenger Deep for seven total releases. Four landers were deployed on 16 December into the central basin: the baited video-equipped lander "Leggo" for biologics; the lander "ARI" to for water chemistry; and the probes "Deep Sound 3" and "Deep Sound 2". Both Deep Sound probes recorded acoustics floating at depth, until "Deep Sound 3" imploded at the depth of (about above the bottom) at . The "Deep Sound 2" recorded the implosion of "Deep Sound 3", providing a unique recording of an implosion within the Challenger Deep depression. In addition to the loss of the "Deep Sound 3" by implosion, the lander "ARI" failed to respond upon receiving its instruction to drop weights, and was never recovered. On 16/17 December, "Leggo" was returned to the central basin baited for amphipods. On the 17th, RV "Falkor" relocated 17 nms eastward to the eastern basin, where they again deployed both the "Leggo" (baited and with its full camera load), and the "Deep Sound 2". "Deep Sound 2" was programmed to drop to and remain at that depth during its recording of sounds within the trench. On 19 December "Leggo" landed at at a uncorrected depth of according to its pressure sensor readings. This reading was corrected to depth. "Leggo" returned with good photography of amphipods feeding on the lander’s mackerel bait and with sample amphipods. "Falknor" departed the Challenger Deep on 19 December en route the Marianas Trench Marine National Monument to the Sirena Deep. RV "Falkor" had both a Kongsberg EM302 and EM710 multibeam echosounder for bathymetry, and an Oceaneering C-Nav 3050 global navigation satellite system receiver, capable of calculating geodetic positioning with an accuracy better than horizontally and vertically.
2015 – USCGC "Sequoia" –– From 10-13 July 2015, the Guam-based 1,930-ton US Coast Guard Cutter "Sequoia" (WLB 215) hosted a team of researchers, under chief scientist Robert P. Dziak, from the NOAA Pacific Marine Environmental Laboratory (PMEL), the University of Washington, and Oregon State University, in deploying PMEL's "Full-Ocean Depth Mooring," a 45-meter-long moored deep-ocean hydrophone and pressure sensor array into the western basin of the Challenger Deep. A 6-hour descent into the western basin anchored the array at ± of water depth, at , about 1 km northeast of "Sumner" deepest depth, recorded in 2010. After 16 weeks, the moored array was recovered 2-4 Nov 2015. "Observed sound sources included earthquake signals (T phases), baleen and odontocete cetacean vocalizations, ship propeller sounds, airguns, active sonar and the passing of a Category 4 typhoon." The science team described their results as "...the first multiday, broadband record of ambient sound at Challenger Deep, as well as only the fifth direct depth measurement."
2016 – RV "Xiangyanghong 09" –– The 3,536-ton research vessel "Xiangyanghong 09" deployed on Leg II of the 37th China Cruise Dayang {DY37II) sponsored by the National Deep Sea Center, Qingdao and the Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences (Sanya, Hainan), to the Challenger Deep western basin area (11°22′ N, 142°25′ E) 4 June-12 July 2016. As the mother ship for China’s manned deep submersible "Jiaolong", the expedition carried out an exploration of the Challenger Deep to investigate the geological, biological, and chemical characteristics of the hadal zone. The diving area for this leg was on the southern slope of the Challenger Deep, at depths from about . The submersible completed nine manned dives on the northern backarc and south area (Pacific plate) of the Challenger Deep to depths from . During the cruise, "Jiaolong" regularly deployed gas-tight samplers to collect water near the sea bottom. In a test of navigational proficiency, "Jiaolong" used an Ultra-Short Base Line (USBL) positioning system at a depth more than to retrieve sampling bottles.
2016 – RV "Tansuo 01" –– From 22 June -12 August 2016 (cruises 2016S1 & 2016S2), the Chinese Academy of Sciences’ 6,250-ton submersible support ship "Tansuo 1" (meaning: to explore) on her maiden voyage deployed to the Challenger Deep from her home port of Sanya, Hainan Island. On 12 July 2016, the ROV "Haidou-1" dove to a depth of in the Challenger Deep area. They also cast a free-drop lander, rated free-drop ocean-floor seismic instruments (deployed to ), obtained sediment core samples, and collected over 2000 biological samples from depth ranging from . The "Tansuo 01" operated along the 142°30.00' longitude line, about 30 nmi east of the earlier DY37II cruise survey (see "Xiangyanghong 09" above).
2016 – RV "Sonne" –– In November 2016 sonar mapping of the Challenger Deep area was conducted by the Royal Netherlands Institute for Sea Research (NIOZ)/GEOMAR Helmholtz Centre for Ocean Research Kiel aboard the 8,554-ton Deep Ocean Research Vessel "Sonne". The results were reported in 2017. Using a Kongsberg Maritime EM 122 multi-beam echosounder system coupled to positioning equipment that can determine latitude and longitude the team determined that the Challenger Deep has a maximum depth of at (), with an estimated vertical uncertainty of ± at one standard deviation (≈ 68.3%) confidence level. The analysis of the sonar survey offered a by grid resolution at bottom depth, so small dips in the bottom that are less than that size would be difficult to detect from the 0.5 by 1 degree sonar-emissions at the sea surface. Each 0.5 degree beam width sonar ping expands to cover a circular area about in diameter at depth. The horizontal position of the grid point has an uncertainty of ±, depending on along-track or across-track direction. This depth () and position (about to the northeast) measurements differ significantly from the deepest point determined by the Gardner et al. (2014) study. The observed depth discrepancy with the 2010 sonar mapping and Gardner et al 2014 study are related to the application of differing sound velocity profiles, which are essential for accurate depth determination. "Sonne" used CTD casts about 1.6 km west of the deepest sounding to near the bottom of the Challenger Deep that were used for sound velocity profile calibration and optimization. Likewise the impact of using different projections, datum and ellipsoids during data acquisition can cause positional discrepancies between surveys.
2016 – RV "Shyian 3" –– In December 2016, the CAS 3,300-ton research vessel "Shiyan 3" deployed 33 broadband seismometers onto both the backarc northwest of the Challenger Deep, and onto the near southern Pacific Plate to the southeast, at depths of up to . This cruise was part of a $12 million Chinese-U.S. initiative, led by co-leader Jian Lin of the Woods Hole Oceanographic Institution; a 5-year effort (2017-2021) to image in fine detail the rock layers in and around the Challenger Deep.
2016 – RV "Zhang Jian" –– The newly launched 4,800-ton research vessel (and mothership for the "Rainbow Fish" series of deep submersibles), the "Zhang Jian" departed Shanghai on 3 December. Their cruise was to test three new deep-sea landers, one unmanned search submersible and the new "Rainbow Fish" 11,000-meter manned deep submersible, all capable of diving to 10,000 meters. From 25 to 27 December, three deep-sea landing devices descended into the trench. The first Rainbow Fish lander took photographs, the second took sediment samples, and the third took biological samples. All three landers reached over 10,000 meters, and the third device brought back 103 amphipods. Cui Weicheng, director of Hadal Life Science Research Center at Shanghai Ocean University, led the team of scientists to carry out research at the Challenger Deep in the Mariana Trench. The ship is part of China’s national marine research fleet but is owned by a Shanghai marine technology company.
2017 – RV "Tansuo-1" –– CAS' Institute of Deep-sea Science and Engineering sponsored "Tansuo-1" return to the Challenger Deep 20 January - 5 February 2017 (cruise TS03) with baited traps for capture of fish and other macrobiology near the Challenger and Sirena Deeps. On 29 January they recovered photography and samples of a new species of snailfish from the Northern slope of the Challenger Deep at , newly designated "Pseudoliparis swirei". They also placed four or more CTD casts into the "central" and "eastern" basins of the Challenger Deep, as part of the World Ocean Circulation Experiment (WOCE).
2017 – RV "Shinyo Maru" –– Tokyo University of Marine Science and Technology dispatched the research vessel "Shinyo Maru" to the Mariana Trench 20 January - 5 February 2017 with baited traps for capture of fish and other macrobiology near the Challenger and Sirena Deeps. On 29 January they recovered photography and samples of a new species of snailfish from the Northern slope of the Challenger Deep at , which has been newly designated "Pseudoliparis swirei".
2017 – RV "Kexue 3" –– Water samples were collected at the Challenger Deep from 11 layers of the Mariana Trench in March 2017. Seawater samples from 4 to 4,000 m were collected by Niskin Bottles mounted to a Seabird SBE25 CTDs; whereas water samples at depths from 6,050 m to 8,320 m were collected by a self-designed acoustic-controlled full ocean depth water samplers. In this study, scientists studied the RNA of pico- and nano-plankton from the surface to the hadal zone.
2017 – RV "Kairei" –– JAMSTEC deployed "Kairei" to the Challenger Deep in May 2017 for the express purpose of testing the new full-ocean depth ROV "UROV11K" (Underwater ROV 11,000-meter-capable), as cruise KR 17-08C, under chief scientist Takashi Murashima. The cruise title was: “Sea trial of a full depth ROV "UROV11K" system in the Mariana Trench”. "UROV11K" carried a new 4K High Definition video camera system, and new sensors to monitor the hydrogen-sulfide, methane, oxygen, and hydrogen content of the water. Unfortunately, on "UROV11K" ascent from (at about 11°22.30’N 142°35.8 E, in the "eastern" basin) on 14 May 2017, the ROV’s buoyancy failed at depth, and all efforts to retrieve the ROV were unsuccessful. The rate of descent and drift is not available, but the ROV bottomed to the east of the deepest waters of the eastern basin as revealed by the ship's maneuvering on 14 May. Murashima then directed the Kairei to a location about 35 nmi east of the eastern basin of the Challenger Deep to test a new “Compact Hadal Lander” which made three descents to depths from 7,498 to 8,178 m for testing the Sony 4K camera and for photography of fish and other macro-biologics.
2018 – RV "Shen Kuo" –– On its maiden voyage, the 2,150-ton twin-hulled scientific research vessel "Shen Kuo" (also "Shengkuo", "Shen Ko", or "Shen Quo"), departed Shanghai on 25 November 2018 and returned 8 January 2019. They operated in the Mariana Trench area, and on 13 December tested a system of underwater navigation at a depth exceeding 10,000 metres, during a field trial of the "Tsaihungyuy" (ultra-short baseline) system. Project leader Tsui Veichen stated that, with the tsaihungyuy equipment at depth, it was possible to obtain a signal and determine exact geolocations. The research team from Shanghai Ocean University and Westlake University was led by Cui Weicheng, director of Shanghai Ocean University’s Hadal Science and Technology Research Center (HSRC).
The equipment to be tested included a manned submersible (NOT full ocean depth -- depth achieved not available) and two deep-sea landers, all capable of diving to depths of 10,000 meters, as well as a ROV that can go to 4,500 meters. They took photographs and obtained samples from the trench, including water, sediment, macro-organisms and micro-organisms. “If we can take photos of fish more than 8,145 meters under water,” said Cui, “we will break the current world record. We will test our new equipment including the landing devices. They are second generation. The first generation could only take samples in one spot per dive, but this new second generation can take samples at different depths in one dive. We also tested the ultra short baseline acoustic positioning system on the manned submersible, the future of underwater navigation.”
2019 – RV "Sally Ride" –– In November 2019, as cruise SR1916, a NIOZ team led by chief scientist Hans van Haren, with Scripps technicians, deployed to the Challenger Deep aboard the 2,641-ton research vessel "Sally Ride", to recover a mooring line from the western basin of the Challenger Deep. The long mooring line in the Challenger Deep consisted of top-floatation positioned around depth, two sections of Dyneema neutrally buoyant line, two Benthos acoustic releases and two sections of self-contained instrumentation to measure and store current, salinity and temperature. Around the depth position two current meters were mounted below a long array of 100 high-resolution temperature sensors. In the lower position starting above the sea floor 295 specially designed high-resolution temperature sensors were mounted, the lowest of which was above the trench floor. The mooring line was deployed and left by the NIOZ team during the November 2016 RV "Sonne" expedition with the intention to be recovered in late 2018 by "Sonne". The acoustic commanded release mechanism near the bottom of the Challenger Deep failed at the 2018 attempt. RV "Sally Ride" was made available exclusively for a final attempt to retrieve the mooring line before the release mechanism batteries expired. "Sally Ride" arrived at the Challenger Deep on 2 November. This time a ‘deep release unit’ lowered by one of "Sally Ride" winch-cables to around 1,000 m depth pinged release commands and managed to contact the near-bottom releases. After being nearly three years submerged, mechanical problems had occurred in 15 of the 395 temperature sensors. The first results indicate the occurrence of internal waves in the Challenger Deep.
In 2014, a study was conducted regarding the determination of the depth and location of the Challenger Deep based on data collected previous to and during the 2010 sonar mapping of the Mariana Trench with a Kongsberg Maritime EM 122 multibeam echosounder system aboard USNS "Sumner". This study by James. V. Gardner et al. of the Center for Coastal & Ocean Mapping-Joint Hydrographic Center (CCOM/JHC), Chase Ocean Engineering Laboratory of the University of New Hampshire splits the measurement attempt history into three main groups: early single-beam echo sounders (1950s-1970s), early multibeam echo sounders (1980s - 21st century), and modern (i.e., post-GPS, high-resolution) multibeam echo sounders. Taking uncertainties in depth measurements and position estimation into account the raw data of the 2010 bathymetry of the Challenger Deep vicinity consisting of 2,051,371 soundings from eight survey lines was analyzed. The study concludes that with the best of 2010 multibeam echosounder technologies after the analysis a depth uncertainty of ± (95% confidence level) on 9 degrees of freedom and a positional uncertainty of ± (2drms) remain and the location of the deepest depth recorded in the 2010 mapping is at . The depth measurement uncertainty is a composite of measured uncertainties in the spatial variations in sound-speed through the water volume, the ray-tracing and bottom-detection algorithms of the multibeam system, the accuracies and calibration of the motion sensor and navigation systems, estimates of spherical spreading, attenuation throughout the water volume, and so forth.
The 2010 maximal sonar mapping depths reported by Gardner et.al. in 2014 have not been confirmed by subsequent direct descent (pressure gauge/manometer) measurements at full-ocean depth. These expeditions have reported maximal depths in a narrow range from the 1960 depth of () to the 2019 depth of reported by the RV in the "western" basin. In the "eastern" basin: deepest depths were reported as (ROV ), (ROV "Nereus"), (), benthic lander "Leggo", and ± by ("DSV Limiting Factor") in May 2019. Both the RV "Sonne" expedition in 2016, and the RV "Sally Ride" expedition in 2019 expressed strong reservations concerning the depth corrections applied by the Gardner et al. study of 2014, and serious doubt concerning the accuracy of the deepest depth calculated by Gardner (in the "western" basin), of . Dr. Hans van Haren, chief scientist on the RV "Sally Ride" cruise SR1916, indicated that Gardner's calculations were 69 m too deep due to the "sound velocity profiling by Gardner et al. (2014)."
No one has claimed that a measurement of any maximal depth of the Challenger Deep (either by water pressure or by ensonification) defines either the absolute deepest depth or the geophysical location of the deepest point in the Challenger Deep. Such a claim will require a survey of all three basins by both echosounders and pressure gauges, such that all depths are measured by one set of equipment and use the same correction calculations. Even then, there will remain uncertainty (error bars) of one or two standard deviations in both location and depth. Technology will improve, but uncertainty will continue to drive efforts to fully describe the Challenger Deep.
On 23 January 1960, the Swiss-designed "Trieste", originally built in Italy and acquired by the U.S. Navy, supported by the USS "Wandank" (ATF 204) and escorted by the USS "Lewis" (DE 535), descended to the ocean floor in the trench manned by Jacques Piccard (who co-designed the submersible along with his father, Auguste Piccard) and USN Lieutenant Don Walsh. Their crew compartment was inside a spherical pressure vessel - measuring 2.16 metres in diameter suspended beneath a buoyancy tank 18.4 metres in length - which was a heavy-duty replacement (of the Italian original) built by Krupp Steel Works of Essen, Germany. The steel walls were 12.7 cm thick and designed to withstand pressure of up to .
Their descent took almost five hours and the two men spent barely twenty minutes on the ocean floor before undertaking the three-hour-and-fifteen-minute ascent. Their early departure from the ocean floor was due to their concern over a crack in the outer window caused by the temperature differences during their descent.
"Trieste" dove at/near , bottoming at ± into the Challenger Deep's "western" basin, as measured by an onboard manometer. Another source states the measured depth at the bottom was measured with a manometer at ±.
Navigation of the support ships was by celestial and LORAN-C with an accuracy of or less. Fisher noted that the "Trieste"’s reported depth “agrees well with the sonic sounding.”
On 26 March 2012 (local time), Canadian film director James Cameron made a solo manned descent in the DSV "Deepsea Challenger" to the bottom of the Challenger Deep.
At approximately 05:15 ChST on 26 March (19:15 UTC on 25 March), the descent began.
At 07:52 ChST (21:52 UTC), "Deepsea Challenger" arrived at the bottom. The descent lasted 2 hours and 36 minutes and the recorded depth was when "Deepsea Challenger" touched down.
Cameron had planned to spend about six hours near the ocean floor exploring but decided to start the ascent to the surface after only 2 hours and 34 minutes. The time on the bottom was shortened because a hydraulic fluid leak in the lines controlling the manipulator arm obscured the visibility out the only viewing port. It also caused the loss of the submersible's starboard thrusters. At around 12:00 ChST (02:00 UTC on 26 March), the Deepsea Challenger website says the sub resurfaced after a 90-minute ascent, although Paul Allen's tweets indicate the ascent took only about 67 minutes.
During a post-dive press conference Cameron said: "I landed on a very soft, almost gelatinous flat plain. Once I got my bearings, I drove across it for quite a distance ... and finally worked my way up the slope." The whole time, Cameron said, he didn't see any fish, or any living creatures more than an inch (2.54 cm) long: "The only free swimmers I saw were small amphipods"—shrimplike bottom-feeders.
The Five Deeps Expedition objective was to thoroughly map and visit the deepest points of all five of the world's oceans by the end of September 2019. On 28 April 2019, explorer Victor Vescovo descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle "DSV Limiting Factor" (a Triton 36000/2 model submersible). Between 28 April and 4 May 2019, the "Limiting Factor" completed four dives to the bottom of Challenger Deep. The fourth dive descended to the slightly less deep "Central Pool" of the Challenger Deep (crew: Patrick Lahey, Pilot; John Ramsay, Sub Designer). The Five Deeps Expedition estimated maximum depths of ± and ± at () by direct CTD pressure measurements and a survey of the operating area by the support ship, the Deep Submersible Support Vessel "DSSV Pressure Drop", with a Kongsberg SIMRAD EM124 multibeam echosounder system. The CTD measured pressure at of seawater depth was . Due to a technical problem the (unmanned) ultra-deep-sea lander "Skaff" used by the Five Deeps Expedition stayed on the bottom for two and half days before it was salvaged by the "Limiting Factor" (crew: Patrick Lahey, Pilot; Jonathan Struwe, DNV GL Specialist) from an estimated depth of . The gathered data was published with the caveat that it was subject to further analysis and could possibly be revised in the future. The data will be donated to the GEBCO Seabed 2030 initiative. Later in 2019, following a review of bathymetric data, and multiple sensor recordings taken by the "DSV Limiting Factor" and the ultra-deep-sea landers "Closp", "Flere" and "Skaff", the Five Deeps Expedition revised the maximum depth to ±.
Caladan Oceanic's "Ring of Fire" expedition in the Pacific is planned to include as many as eight crewed descends into all three basins of the Challenger Deep all piloted by Victor Vescovo and further topographical and marine life survey of the entire Challenger Deep. The expedition craft used are the Deep Submersible Support Vessel "DSSV Pressure Drop", Deep-Submergence Vehicle "DSV Limiting Factor" and the ultra-deep-sea landers "Closp", "Flere" and "Skaff".
During the first crewed dive on 7 June 2020 Victor Vescovo and former US astronaut (and former NOAA Administrator) Kathryn D. Sullivan descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle "Limiting Factor".
On 12 June 2020 Victor Vescovo and mountaineer and explorer Vanessa O'Brien descended to the "Eastern Pool" of the Challenger Deep spending three hours mapping the bottom. O’Brien said her dive scanned about a mile of desolate bottom terrain, finding that the surface is not flat, as once was thought, but sloping, and by about , subject to verification, of course.
On 14 June 2020 Victor Vescovo and John Rost descended to the "Eastern Pool" of the Challenger Deep in the Deep-Submergence Vehicle "Limiting Factor" spending four hours at depth and transiting the bottom for nearly 2 miles.
On 20 June 2020 Victor Vescovo and Kelly Walsh descended to the "Western Pool" of the Challenger Deep in the Deep-Submergence Vehicle "Limiting Factor" spending four hours at the bottom. Kelly Walsh is the son of the "Trieste’s" captain Don Walsh who descended there in 1960 with Jacques Piccard.
On 21 June 2020 Victor Vescovo and Woods Hole Oceanographic Institution researcher Ying-Tsong Lin descended to the "Central Pool" of the Challenger Deep in the Deep-Submergence Vehicle "Limiting Factor".
In January 2020, Caladan Oceanic commenced its second year of deep diving with the "DSV Limiting Factor", piloted by Victor Vescovo. The first dives of the 2020 season commenced with dives to the French submarine "Minerve" in the Mediterranean Sea on 1–2 February, and are to include several dives in the Red Sea and Indian Ocean before returning to the Challenger Deep in June/July 2020.
As of 2020, several other manned expeditions are planned. These include:
Virgin Oceanic, sponsored by Richard Branson's Virgin Group, was developing a submersible designed by Graham Hawkes, DeepFlight Challenger, but the project was quietly shelved in 2014.
The remotely operated vehicle (ROV) "Kaikō" made many unmanned descents to the Mariana Trench from its support ship RV "Yokosuka" during two expeditions in 1996 and 1998.
From 29 February to 4 March the ROV "Kaiko" three dives into the "central" basin, "Kaiko" #21 – "Kaiko" #23, . Depths ranged from at , to at ; dives #22 & #23 to the north, and dive #21 northeast of the deepest waters of the "central" basin. During the 1996 measurements the temperature (water temperature increases at great depth due to adiabatic compression), salinity and water pressure at the sampling station was , 34.7‰ and , respectively at depth. The Japanese robotic deep-sea probe "Kaikō" broke the depth record for unmanned probes when it reached close to the surveyed bottom of the Challenger Deep. Created by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), it was one of the few unmanned deep-sea probes in operation that could dive deeper than . The manometer measured depth of ± at for the Challenger Deep is believed to be the most accurate measurement taken up to then.
Another source states the greatest depth measured by "Kaikō" in 1996 was at and in 1998 at .
The ROV "Kaiko" was the first vehicle to visit to the bottom of the Challenger Deep since the bathyscaph "Trieste"’s dive in 1960, and the first success in sampling the trench bottom sediment/mud, from which "Kaiko" obtained over 360 samples. Approximately 3000 different microbes were identified in the samples.
"Kaikō" was lost at sea off Shikoku Island during Typhoon Chan-Hom on 29 May 2003.
From 2 May to 5 June 2009, the RV "Kilo Moana" hosted the Woods Hole Oceanographic Institution (WHOI) hybrid remotely operated vehicle (HROV) "Nereus" team for the first operational test of the "" in its 3-ton teathered ROV mode. The "Nereus" team was headed by Dr. Louis Whitcomb of Johns Hopkins University, and Dr. Dana Yoerger and Andy Bowen of WHOI. The University of Hawaii sent two chief scientists: biologist Tim Shank, and geologist Patricia Fryer, to head the science team exploiting the ship’s bathymetry and organizing the science experiments deployed by the "Nereus". From "Nereus" dive #007ROV to just south of Guam, to dive #010ROV into the Nero Deep at , the testing gradually increased depths and complexities of activities at the bottom.
Dive #011ROV, on 31 May 2009, saw the "Nereus" piloted on a 27.8-hour underwater mission, with about ten hours transversing the "eastern" basin of the Challenger Deep -- from the south wall, northwest to the north wall -- streaming live video and data back to its mothership. A maximum depth of was registered at . The "" then relocated to the "western" basin, where a 19.3-hour underwater dive found a maximum depth of on dive #012ROV, and on dive #014ROV in the same area (11°19.59 N, 142°12.99 E) encountered a maximum depth of . The "Nereus" was successful in recovering both sediment and rock samples from the "eastern" and the "western" basins with its manipulator arm for further scientific analysis. The HROV’s final dive was about to the north of the Challenger Deep, in the backarc, where they dove at the TOTO Caldera (12°42.00 N, 143°31.5 E). Nereus thus became the first vehicle to reach the Mariana Trench since 1998 and the deepest-diving vehicle then in operation. Project manager and developer Andy Bowen heralded the achievement as "the start of a new era in ocean exploration". "Nereus", unlike "Kaikō", did not need to be powered or controlled by a cable connected to a ship on the ocean surface.
The HROV "Nereus" was lost on 10 May 2014 while conducting a dive at in depth in the Kermadec Trench.
In June 2008, the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) deployed the research vessel "Kairei" to the area of Guam for cruise KR08-05 Leg 1 and Leg 2.
On 1-3 June 2008, during Leg 1, the Japanese robotic deep-sea probe "ABISMO" (Automatic Bottom Inspection and Sampling Mobile) on dives 11-13 almost reached the bottom about east of the Challenger Deep: "Unfortunately, we were unable to dive to the sea floor because the legacy primary cable of the Kaiko system was a little bit short. The 2-m long gravity core sampler was dropped in free fall, and sediment samples of 1.6m length were obtained. Twelve bottles of water samples were also obtained at various depths..." ABISMO's dive #14 was into the TOTO caldera (12°42.7777 N, 143°32.4055 E), about 60 nmi northeast of the deepest waters of the "central" basin of the Challenger Deep, where they obtained videos of the hydrothermal plume. Upon successful testing to , JAMSTEC’ ROV "ABISMO" became, briefly, the only full-ocean-depth rated ROV in existence. On 31 May 2009, the ABISMO was joined by the Woods Hole Oceanographic Institution's HROV "Nereus" as the only two operational full ocean depth capable remotely operated vehicles in existence. During the ROV "ABISMO's" deepest sea trails dive its manometer measured a depth of ± in “Area 1” (vicinity of 12°43’ N, 143°33’ E).
Leg 2, under chief scientist Takashi Murashima, operated at the Challenger Deep 8–9 June 2008, testing JAMSTEC’s new full ocean depth “Free Fall Mooring System,” i.e. a lander. The lander was successfully tested twice to depth, taking video images and sediment samplings at , in the "central" basin of the Challenger Deep.
On 23 May 2016, the Chinese submersible "Haidou-1" dove to a depth of at an undisclosed position in the Mariana Trench, making China the third country after Japan (ROV "Kaikō"), and the US (HROV "Nereus"), to deploy a full-ocean-depth ROV. This autonomous and remotely operated vehicle has a design depth of .
On 8 May 2020, the Russian submersible "Vityaz-D" dove to a depth of at an undisclosed position in the Mariana Trench.
The summary report of the expedition lists radiolaria from the two dredged samples taken when the Challenger Deep was first discovered. These (Nassellaria and Spumellaria) were reported in the Report on Radiolaria (1887) written by Ernst Haeckel.
On their 1960 descent, the crew of the "Trieste" noted that the floor consisted of diatomaceous ooze and reported observing "some type of flatfish" lying on the seabed.
Many marine biologists are now skeptical of this supposed sighting, and it is suggested that the creature may instead have been a sea cucumber. The video camera on board the "Kaiko" probe spotted a sea cucumber, a scale worm and a shrimp at the bottom. At the bottom of the Challenger deep, the "Nereus" probe spotted one polychaete worm (a multi-legged predator) about an inch long.
An analysis of the sediment samples collected by "Kaiko" found large numbers of simple organisms at . While similar lifeforms have been known to exist in shallower ocean trenches (> 7,000 m) and on the abyssal plain, the lifeforms discovered in the Challenger Deep possibly represent taxa distinct from those in shallower ecosystems.
Most of the organisms collected were simple, soft-shelled foraminifera (432 species according to National Geographic), with four of the others representing species of the complex, multi-chambered genera "Leptohalysis" and "Reophax". Eighty-five percent of the specimens were organic, soft-shelled allogromiids, which is unusual compared to samples of sediment-dwelling organisms from other deep-sea environments, where the percentage of organic-walled foraminifera ranges from 5% to 20%. As small organisms with hard, calcareous shells have trouble growing at extreme depths because of the high solubility of calcium carbonate in the pressurized water, scientists theorize that the preponderance of soft-shelled organisms in the Challenger Deep may have resulted from the typical biosphere present when the Challenger Deep was shallower than it is now. Over the course of six to nine million years, as the Challenger Deep grew to its present depth, many of the species present in the sediment died out or were unable to adapt to the increasing water pressure and changing environment. The species that survived the change in depth were the ancestors of the Challenger Deep's current denizens.
On 17 March 2013, researchers reported data that suggested microbial life forms thrive in the Challenger Deep. Other researchers reported related studies that microbes thrive inside rocks up to below the sea floor under of ocean off the coast of the northwestern United States. According to one of the researchers, "You can find microbes everywherethey're extremely adaptable to conditions, and survive wherever they are." | https://en.wikipedia.org/wiki?curid=7786 |
Claude Louis Berthollet
Claude Louis Berthollet (9 December 1748 in Talloires, France – 6 November 1822 in Arcueil, France) was a Savoyard-French chemist who became vice president of the French Senate in 1804. He is known for his scientific contributions to theory of chemical equilibria via the mechanism of reverse chemical reactions, and for his contribution to modern chemical nomenclature. On a practical basis, Berthollet was the first to demonstrate the bleaching action of chlorine gas, and was first to develop a solution of sodium hypochlorite as a modern bleaching agent.
Claude Louis Berthollet was born in Talloires, near Annecy, then part of the Duchy of Savoy, in 1749.
He started his studies at Chambéry and then in Turin where he graduated in medicine. Berthollet's great new developments in works regarding chemistry made him, in a short period of time, an active participant of the Academy of Science in 1780.
Berthollet, along with Antoine Lavoisier and others, devised a chemical nomenclature, or a system of names, which serves as the basis of the modern system of naming chemical compounds.
He also carried out research into dyes and bleaches, being first to introduce the use of chlorine gas as a commercial bleach in 1785. He first produced a modern bleaching liquid in 1789 in his laboratory on the quay Javel in Paris, France, by passing chlorine gas through a solution of sodium carbonate. The resulting liquid, known as ""Eau de Javel"" ("Javel water"), was a weak solution of sodium hypochlorite. Another strong chlorine oxidant and bleach which he investigated and was the first to produce, potassium chlorate (KClO3), is known as "Berthollet's Salt".
Berthollet first determined the elemental composition of the gas ammonia, in 1785.
Berthollet was one of the first chemists to recognize the characteristics of a reverse reaction, and hence, chemical equilibrium.
Berthollet was engaged in a long-term battle with another French chemist, Joseph Proust, on the validity of the law of definite proportions. While Proust believed that chemical compounds are composed of a fixed ratio of their constituent elements irrespective of the methods of production, Berthollet believed that this ratio can change according to the ratio of the reactants initially taken. Although Proust proved his theory by accurate measurements, his theory was not immediately accepted partially due to Berthollet's authority. His law was finally accepted when Berzelius confirmed it in 1811, but it was found later that Berthollet was not completely wrong because there exists a class of compounds that do not obey the law of definite proportions. These non-stoichiometric compounds are also named "berthollides" in his honor.
Berthollet was one of several scientists who went with Napoleon to Egypt and was a member of the physics and natural history section of the Institut d'Égypte.
In April, 1789 Berthollet was elected a Fellow of the Royal Society of London. In 1801, he was elected a foreign member of the Royal Swedish Academy of Sciences. In 1809, Berthollet was elected an associate member first class of the Royal Institute of the Netherlands, predecessor of the Royal Netherlands Academy of Arts and Sciences. He was elected an Honorary Fellow of the Royal Society of Edinburgh in 1820 and a Foreign Honorary Member of the American Academy of Arts and Sciences in 1822.
Claude-Louis Berthollet's 1788 publication entitled "Méthode de Nomenclature Chimique", published with colleagues Antoine Lavoisier, Louis Bernard Guyton de Morveau, and Antoine François, comte de Fourcroy, was honored by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society, presented at the Académie des Sciences (Paris) in 2015.
A French High School located in Annecy is named after him (Lycée Claude Louis Berthollet).
Berthollet married Marguerite Baur in 1788.
Berthollet was accused of being an atheist.
He died in Arcueil, France in 1822. | https://en.wikipedia.org/wiki?curid=7787 |
Crystallography
Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids (see crystal structure). The word "crystallography" is derived from the Greek words "crystallon" "cold drop, frozen drop", with its meaning extending to all solids with some degree of transparency, and "graphein" "to write". In July 2012, the United Nations recognised the importance of the science of crystallography by proclaiming that 2014 would be the International Year of Crystallography.
Before the development of X-ray diffraction crystallography (see below), the study of crystals was based on physical measurements of their geometry using a goniometer. This involved measuring the angles of crystal faces relative to each other and to theoretical reference axes (crystallographic axes), and establishing the symmetry of the crystal in question. The position in 3D space of each crystal face is plotted on a stereographic net such as a Wulff net or Lambert net. The pole to each face is plotted on the net. Each point is labelled with its Miller index. The final plot allows the symmetry of the crystal to be established.
Crystallographic methods now depend on analysis of the diffraction patterns of a sample targeted by a beam of some type. X-rays are most commonly used; other beams used include electrons or neutrons. Crystallographers often explicitly state the type of beam used, as in the terms "X-ray crystallography, neutron diffraction" and "electron diffraction". These three types of radiation interact with the specimen in different ways.
Because of these different forms of interaction, the three types of radiation are suitable for different crystallographic studies.
With conventional imaging technique such as optical microscopy, obtaining an image of a small object requires collecting light with a magnifying lens. However, the resolution of any optical system is limited by the diffraction-limit of light, which depends on its wavelength. For example, visible light has a wavelength of about 4000 to 7000 ångström, which is three orders of magnitude longer than the length of typical atomic bonds and atoms themselves (about 1 to 2 Å). Therefore, a conventional optical microscope cannot resolve the spatial arrangement of atoms in a crystal. To do so, we would need radiation with much shorter wavelengths, such as X-ray or neutron beams.
Unfortunately, focusing X-rays with conventional optical lens can be a challenge. Scientists have had some success focusing X-rays with microscopic Fresnel zone plates made from gold, and by critical-angle reflection inside long tapered capillaries. Diffracted X-ray or neutron beams cannot be focused to produce images, so the sample structure must be reconstructed from the diffraction pattern.
Diffraction patterns arise from the constructive interference of incident radiation (x-rays, electrons, neutrons), scattered by the periodic, repeating features of the sample. Because of their highly ordered and repetitive atomic structure (Bravais lattice), crystals diffract x-rays in a coherent manner, also referred to as Bragg's reflection.
Some materials that have been analyzed crystallographically, such as proteins, do not occur naturally as crystals. Typically, such molecules are placed in solution and allowed to slowly crystallize through vapor diffusion. A drop of solution containing the molecule, buffer, and precipitants is sealed in a container with a reservoir containing a hygroscopic solution. Water in the drop diffuses to the reservoir, slowly increasing the concentration and allowing a crystal to form. If the concentration were to rise more quickly, the molecule would simply precipitate out of solution, resulting in disorderly granules rather than an orderly and hence usable crystal.
Once a crystal is obtained, data can be collected using a beam of radiation. Although many universities that engage in crystallographic research have their own X-ray producing equipment, synchrotrons are often used as X-ray sources, because of the purer and more complete patterns such sources can generate. Synchrotron sources also have a much higher intensity of X-ray beams, so data collection takes a fraction of the time normally necessary at weaker sources. Complementary neutron crystallography techniques are used to identify the positions of hydrogen atoms, since X-rays only interact very weakly with light elements such as hydrogen.
Producing an image from a diffraction pattern requires sophisticated mathematics and often an iterative process of modelling and refinement. In this process, the mathematically predicted diffraction patterns of an hypothesized or "model" structure are compared to the actual pattern generated by the crystalline sample. Ideally, researchers make several initial guesses, which through refinement all converge on the same answer. Models are refined until their predicted patterns match to as great a degree as can be achieved without radical revision of the model. This is a painstaking process, made much easier today by computers.
The mathematical methods for the analysis of diffraction data only apply to "patterns," which in turn result only when waves diffract from orderly arrays. Hence crystallography applies for the most part only to crystals, or to molecules which can be coaxed to crystallize for the sake of measurement. In spite of this, a certain amount of molecular information can be deduced from patterns that are generated by fibers and powders, which while not as perfect as a solid crystal, may exhibit a degree of order. This level of order can be sufficient to deduce the structure of simple molecules, or to determine the coarse features of more complicated molecules. For example, the double-helical structure of DNA was deduced from an X-ray diffraction pattern that had been generated by a fibrous sample.
Crystallography is used by materials scientists to characterize different materials. In single crystals, the effects of the crystalline arrangement of atoms is often easy to see macroscopically, because the natural shapes of crystals reflect the atomic structure. In addition, physical properties are often controlled by crystalline defects. The understanding of crystal structures is an important prerequisite for understanding crystallographic defects. Mostly, materials do not occur as a single crystal, but in poly-crystalline form (i.e., as an aggregate of small crystals with different orientations). Because of this, the powder diffraction method, which takes diffraction patterns of polycrystalline samples with a large number of crystals, plays an important role in structural determination.
Other physical properties are also linked to crystallography. For example, the minerals in clay form small, flat, platelike structures. Clay can be easily deformed because the platelike particles can slip along each other in the plane of the plates, yet remain strongly connected in the direction perpendicular to the plates. Such mechanisms can be studied by crystallographic texture measurements.
In another example, iron transforms from a body-centered cubic (bcc) structure to a face-centered cubic (fcc) structure called austenite when it is heated. The fcc structure is a close-packed structure unlike the bcc structure; thus the volume of the iron decreases when this transformation occurs.
Crystallography is useful in phase identification. When manufacturing or using a material, it is generally desirable to know what compounds and what phases are present in the material, as their composition, structure and proportions will influence the material's properties. Each phase has a characteristic arrangement of atoms. X-ray or neutron diffraction can be used to identify which patterns are present in the material, and thus which compounds are present. Crystallography covers the enumeration of the symmetry patterns which can be formed by atoms in a crystal and for this reason is related to group theory and geometry.
X-ray crystallography is the primary method for determining the molecular conformations of biological macromolecules, particularly protein and nucleic acids such as DNA and RNA. In fact, the double-helical structure of DNA was deduced from crystallographic data. The first crystal structure of a macromolecule was solved in 1958, a three-dimensional model of the myoglobin molecule obtained by X-ray analysis. The Protein Data Bank (PDB) is a freely accessible repository for the structures of proteins and other biological macromolecules. Computer programs such as RasMol, Pymol or VMD can be used to visualize biological molecular structures.
Neutron crystallography is often used to help refine structures obtained by X-ray methods or to solve a specific bond; the methods are often viewed as complementary, as X-rays are sensitive to electron positions and scatter most strongly off heavy atoms, while neutrons are sensitive to nucleus positions and scatter strongly even off many light isotopes, including hydrogen and deuterium.
Electron crystallography has been used to determine some protein structures, most notably membrane proteins and viral capsids.
The "International Tables for Crystallography" is an eight-book series that outlines the standard notations for formatting, describing and testing crystals. The series contains books that covers analysis methods and the mathematical procedures for determining organic structure though x-ray crystallography, electron diffraction, and neutron diffraction. The International tables are focused on procedures, techniques and descriptions and do not list the physical properties of individual crystals themselves. Each book is about 1000 pages and the titles of the books are: | https://en.wikipedia.org/wiki?curid=7794 |
Claude Auchinleck
Field Marshal Sir Claude John Eyre Auchinleck, (21 June 1884 – 23 March 1981) was a British Army commander during the Second World War. He was a career soldier who spent much of his military career in India, where he rose to become Commander-in-Chief of the Indian Army by early 1941. In July 1941 he was appointed Commander-in-Chief of the Middle East Theatre, but after initial successes, the war in North Africa turned against the British, and he was relieved of the post in 1942 during the crucial Alamein campaign.
In June 1943, he was once again appointed Commander-in-Chief, India, where his support through the organisation of supply, maintenance and training for William Slim's Fourteenth Army played an important role in its success. He served as Commander-in-Chief, India until the Partition in 1947, when he assumed the role of Supreme Commander of all British forces in India and Pakistan until late 1948.
Born at 89 Victoria Road in Aldershot, the son of Colonel John Claud Alexander Auchinleck and Mary Eleanor (Eyre) Auchinleck, Auchinleck attended Eagle House School at Crowthorne and then Wellington College on scholarships. After attending the Royal Military College, Sandhurst, Auchinleck was commissioned as an unattached second lieutenant in the Indian Army on 21 January 1903 and joined to the 62nd Punjabis in April 1904. He soon learnt several Indian languages and, able to speak fluently with his soldiers, he absorbed a knowledge of local dialects and customs: this familiarity engendered a lasting mutual respect, enhanced by his own personality.
He was promoted to lieutenant on 21 April 1905 and then spent the next two years in Tibet and Sikkim before moving to Benares in 1907 where he caught diphtheria. After briefly serving with the Royal Inniskilling Fusiliers at Aldershot he returned to Benares in 1909 and became adjutant of the 62nd Punjabis with promotion to captain on 21 January 1912. Auchinleck was an active freemason.
Auchinleck saw active service in the First World War and was deployed with his regiment to defend the Suez Canal: in February 1915 he was in action against the Turks at Ismaïlia. His regiment moved into Aden to counter the Turkish threat there in July 1915. The 6th Indian Division, of which the 62nd Punjabis were a part, was landed at Basra on 31 December 1915 for the Mesopotamian campaign. In July 1916 Auchinleck was promoted acting major and made second in command of his battalion. He took part in a series of fruitless attacks on the Turks at the Battle of Hanna in January 1916 and was one of the few British officers in his regiment to survive these actions.
He became acting commanding officer of his battalion in February 1917 and led his regiment at the Second Battle of Kut in February 1917 and the Fall of Baghdad in March 1917. Having been mentioned in despatches and having received the Distinguished Service Order in 1917 for his service in Mesopotamia, he was promoted to the substantive rank of major on 21 January 1918, to temporary lieutenant-colonel on 23 May 1919 and to brevet lieutenant-colonel on 15 November 1919 for his "distinguished service in Southern and Central Kurdistan" on the recommendation of the Commander-in-Chief of the Mesopotamia Expeditionary Force.
Auchinleck attended the Staff College, Quetta between 1920 and 1921. He married Jessie Stewart in 1921. Jessie had been born in 1900 in Tacoma, Washington, to Alexander Stewart, head of the Blue Funnel Line that plied the west coast of the United States. When he died about 1919, their mother took her, her twin brother Alan and her younger brother Hepburne back to Bun Rannoch, the family estate at Innerhadden in Perthshire. Holidaying at Grasse on the French Riviera, Auchinleck, who was on leave from India at the time, met Jessie on the tennis courts. She was a high-spirited, blue-eyed beauty. Things moved quickly, and they were married within five months. Sixteen years younger than Auchinleck, Jessie became known as 'the little American girl' in India, but adapted readily to life there. They had no children.
Auchinleck became temporary Deputy Assistant Quartermaster-General at Army Headquarters in February 1923 and then second-in-command of his regiment, which in the 1923 reorganisation of the Indian Army had become the 1st battalion, 1st Punjab Regiment, in September 1925. He attended the Imperial Defence College in 1927 and, having been promoted to lieutenant-colonel on 21 January 1929 he was appointed to command his regiment. Promoted to full colonel on 1 February 1930 with seniority from 15 November 1923, he became an instructor at the Staff College, Quetta in February 1930 where he remained until April 1933.
He was promoted to temporary brigadier on 1 July 1933 and given command of the Peshawar Brigade, which was active in the pacification of the adjacent tribal areas during the Mohmand and Bajaur Operations between July and October 1933: during his period of command he was mentioned in despatches. He led a second punitive expedition during the Second Mohmand Campaign in August 1935 for which he was again mentioned in despatches, promoted to major-general on 30 November 1935 and appointed a Companion of the Order of the Star of India on 8 May 1936.
On leaving his brigade command in April 1936, Auchinleck was on the unemployed list (on half pay) until September 1936 when he was appointed Deputy Chief of the General Staff and Director of Staff Duties in Delhi. He was then appointed to command the Meerut District in India in July 1938. In 1938 Auchinleck was appointed to chair a committee to consider the modernisation, composition and re-equipment of the British Indian Army: the committee's recommendations formed the basis of the 1939 Chatfield Report which outlined the transformation of the Indian Army – it grew from 183,000 in 1939 to over 2,250,000 men by the end of the war.
On the outbreak of war Auchinleck was appointed to command the Indian 3rd Infantry Division but in January 1940 was summoned to the United Kingdom to command IV Corps, the only time in the war that a wholly British corps was commanded by an Indian Army officer. He received promotion to acting Lieutenant-General on 1 February 1940 and to the substantive rank of Lieutenant-General on 16 March 1940. In May 1940 Auchinleck took over command of the Anglo-French ground forces in Norway, a military operation that was doomed to fail.
After the fall of Norway, in June 1940 he briefly commanded V Corps before becoming General Officer Commanding-in-Chief, Southern Command in July 1940, where he had an uneasy relationship with his subordinate Bernard Montgomery, the new V Corps commander. Montgomery later wrote: "In the 5th Corps I first served under Auchinleck... I cannot recall that we ever agreed on anything."
Promoted to full general on 26 December 1940, Auchinleck was recalled to India in January 1941 to become Commander-in-Chief, India in which position he also was appointed to the Executive Council of the Governor-General of India and appointed ADC General to the King which ceremonial position he held until after the end of the War.
In April 1941, RAF Habbaniya was threatened by the new pro-Axis regime of Rashid Ali. This large Royal Air Force station was west of Baghdad in Iraq and General Archibald Wavell, Commander-in-Chief Middle East Command, was reluctant to intervene, despite the urgings of Winston Churchill, because of his pressing commitments in the Western Desert and Greece. Auchinleck, however, acted decisively, sending a battalion of the King's Own Royal Regiment by air to Habbaniya and shipping the Indian 10th Infantry Division by sea to Basra. Wavell was prevailed upon by London to send "Habforce", a relief column, from the British Mandate of Palestine but by the time it arrived in Habbaniya on 18 May the Anglo-Iraqi War was virtually over.
Following the see-saw of Allied and Axis successes and reverses in North Africa, Auchinleck was appointed to succeed General Sir Archibald Wavell as Commander-in-Chief Middle East Command in July 1941; Wavell took up Auchinleck's post as Commander-in-Chief of the Indian Army, swapping jobs with him.
As Commander-in-Chief Middle East Auchinleck, based in Cairo, held responsibility not just for North Africa but also for Persia and the Middle East. He launched an offensive in the Western Desert, Operation Crusader, in November 1941: despite some tactical reverses during the fighting which resulted in Auchinleck replacing the Eighth Army commander Alan Cunningham with Neil Ritchie, by the end of December the besieged garrison of Tobruk had been relieved and Rommel obliged to withdraw to El Agheila. Auchinleck appears to have believed that enemy had been defeated, writing on 12 January 1942 that the Axis forces were "beginning to feel the strain" and were "hard pressed".
In fact the Axis forces had managed to withdraw in good order and a few days after Auchinleck's optimistic appreciation, having reorganised and been reinforced, struck at the dispersed and weakened British forces, driving them back to the Gazala positions near Tobruk. The British Chief of the Imperial General Staff (CIGS), General Sir Alan Brooke, wrote in his diary that it was "nothing less than bad generalship on the part of Auchinleck. He has been overconfident and has believed everything his overoptimistic [DMI] Shearer has told him". Brooke commented that Auchinleck "could have been one of the finest of commanders" but lacked the ability to select the men to serve him. Brooke sent him one of his best armoured division commanders Richard McCreery, whose advice was ignored in favour of Dorman-Smith's.
Rommel's attack at the Battle of Gazala of 26 May 1942 resulted in a significant defeat for the British. Auchinleck's appreciation of the situation written to Ritchie on 20 May had suggested that the armoured reserves be concentrated in a position suitable to meet both a flanking attack around the south of the front or a direct attack through the centre (which was the likelihood more favoured by Auchinleck). In the event, Ritchie chose a more dispersed and rearward positioning of his two armoured divisions and when the attack in the centre came, it proved to be a diversion and the main attack, by Rommel's armoured formations, came round the southern flank. Poor initial positioning and subsequent handling and coordination of Allied formations by Ritchie and his corps commanders resulted in their heavy defeat and the Eighth Army retreating into Egypt; Tobruk fell to the Axis on 21 June 1942.
On 24 June Auchinleck stepped in to take direct command of the Eighth Army, having lost confidence in Neil Ritchie's ability to control and direct his forces. Auchinleck discarded Ritchie's plan to stand at Mersa Matruh, deciding to fight only a delaying action there, while withdrawing to the more easily defendable position at El Alamein. Here Auchinleck tailored a defence that took advantage of the terrain and the fresh troops at his disposal, stopping the exhausted German/Italian advance in the First Battle of El Alamein. Enjoying a considerable superiority of material and men over the weak German/Italian forces, Auchinleck organised a series of counter-attacks. Poorly conceived and badly coordinated, these attacks achieved little.
"The Auk", as he was known, appointed a number of senior commanders who proved to be unsuitable for their positions, and command arrangements were often characterised by bitter personality clashes. Auchinleck was an Indian Army officer and was criticised for apparently having little direct experience or understanding of British and Dominion troops. His controversial chief of operations, Major-General Dorman-Smith, was regarded with considerable distrust by many of the senior commanders in Eighth Army. By July 1942 Auchinleck had lost the confidence of Dominion commanders and relations with his British commanders had become strained.
Like his foe Rommel (and his predecessor Wavell and successor Montgomery), Auchinleck was subjected to constant political interference, having to weather a barrage of hectoring telegrams and instructions from Prime Minister Churchill throughout late 1941 and the spring and summer of 1942. Churchill constantly sought an offensive from Auchinleck, and was downcast at the military reverses in Egypt and Cyrenaica. Churchill was desperate for some sort of British victory before the planned Allied landings in North Africa, Operation Torch, scheduled for November 1942. He badgered Auchinleck immediately after the Eighth Army had all but exhausted itself after the first battle of El Alamein. Churchill and the Chief of the Imperial General Staff, Alan Brooke, flew to Cairo in early August 1942, to meet Auchinleck, where it emerged he had lost the confidence of both men. He was replaced as Commander-in-Chief Middle East Command by General Sir Harold Alexander (later Field Marshal Earl Alexander of Tunis).
Joseph M. Horodyski and Maurice Remy both praise Auchinleck as an underrated military leader who contributed the most to the successful defence of El Alamein and consequently the final defeat of Rommel in Africa. The two historians also criticize Churchill for the unreasonable decision to put the blame on Auchinleck and to relieve him.
Churchill offered Auchinleck command of the newly created Persia and Iraq Command (this having been separated from Alexander's command), but Auchinleck declined this post, as he believed that separating the area from the Middle East Command was not good policy and the new arrangements would not be workable. He set his reasons out in his letter to the Chief of the Imperial General Staff dated 14 August 1942. Instead he returned to India, where he spent almost a year "unemployed" before in June 1943 being again appointed Commander-in-Chief of the Indian Army,
General Wavell meanwhile having been appointed Viceroy, on this appointment it was announced that responsibility for the prosecution of the war with Japan would move from the Commander-in-Chief India to a newly created South East Asia Command. However, the appointment of the new command's Supreme Commander, Admiral Louis Mountbatten, was not announced until August 1943 and until Mountbatten could set up his headquarters and assume control (in November) Auchinleck retained responsibility for operations in India and Burma while conducting a review and revision of Allied plans based on the decisions taken by the Allied Combined Chiefs of Staff at the Quadrant Conference which ended in August.
Following Mountbatten's arrival, Auchinleck's India Command (which had equal status with South East Asia Command in the military hierarchy) was responsible for the internal security of India, the defence of the North West Frontier and the buildup of India as a base, including most importantly the reorganisation of the Indian Army, the training of forces destined for SEAC and the lines of communication carrying men and material to the forward areas and to China. Auchinleck made the supply of Fourteenth Army, with probably the worst lines of communication of the war, his immediate priority; as William Slim, commander of the Fourteenth Army was later to write:
Auchinleck suffered a personal disappointment when his wife Jessie left him for his friend Air Chief Marshal Sir Richard Peirse. Peirse and Auchinleck had been students together at the Imperial Defence College, but that was long before. Peirse was now Allied Air Commander-in-Chief, South-East Asia, and also based in India. The affair became known to Mountbatten in early 1944, and he passed the information to the Chief of the RAF, Sir Charles Portal, hoping that Peirse would be recalled. The affair was common knowledge by September 1944, and Peirse was neglecting his duties. Mountbatten sent Peirse and Lady Auchinleck back to England on 28 November 1944, where they lived together at a Brighton hotel. Peirse had his marriage dissolved, and Auchinleck obtained a divorce in 1946. Auchinleck was reportedly very badly affected. According to his sister, he was never the same after the break-up. He always carried a photograph of Jessie in his wallet even after the divorce.
There is scholarly dispute whether Auchinleck was homosexual. His biographer, Philip Warner, addressed the rumours but dismissed them; however historian Ronald Hyam has alleged that "sexually based moral-revulsion" was the reason for Montgomery's inability to get on with Auchinleck, and further, that Auchinleck was "let off with a high-level warning" over his relationships with Indian boys.
Auchinleck continued as Commander-in-Chief of the Indian Army after the end of the war helping, though much against his own convictions, to prepare the future Indian and Pakistani armies for the Partition of India: in November 1945 he was forced to commute the more serious judicial sentences awarded against officers of the Indian National Army in face of growing unease and unrest both within the Indian population, and the British Indian Army. On 1 June 1946 he was promoted to field marshal, but he refused to accept a peerage, lest he be thought associated with a policy (i.e. Partition) that he thought fundamentally dishonourable.
Sending a report to British Government on 28 September 1947 Auchinleck wrote: "I have no hesitation, whatever, in affirming that the present Indian Cabinet are implacably determined to do all in their power to prevent the establishment of the Dominion of Pakistan on firm basis." He stated in the second, political part of his assessment, "Since 15th August, the situation has steadily deteriorated and the Indian leaders, cabinet ministers, civil officials and others have persistently tried to obstruct the work of partition of the armed forces."
When partition was effected in August 1947, Auchinleck was appointed Supreme Commander of all British forces remaining in India and Pakistan and remained in this role until the winding up and closure of the Supreme H.Q. at the end of November 1948. This marked his effective retirement from the army (although technically field marshals in the British Army never retire, remaining on the active list on half pay). He left India on 1 December.
After a brief period in Italy in connection with an unsuccessful business project, Auchinleck retired to London, where he occupied himself with a number of charitable and business interests and became a respectably skilled watercolour painter. In 1960 he settled in Beccles in the county of Suffolk, remaining there for seven years until, at the age of eighty-four, he decided to emigrate and set up home in Marrakesh, where he died on 23 March 1981.
Auchinleck was buried in Ben M'Sik European Cemetery, Casablanca, in the Commonwealth War Graves Commission plot in the cemetery, next to the grave of Raymond Steed who was the second youngest non-civilian Commonwealth casualty of the Second World War.
A memorial plaque was erected in the crypt of St Paul's Cathedral. A bronze statue of Auchinleck can be seen on Broad Street adjacent to Auchinleck House, Five Ways, Birmingham. | https://en.wikipedia.org/wiki?curid=7796 |
Critical psychology
Critical psychology is a perspective on psychology that draws extensively on critical theory. Critical psychology challenges mainstream psychology and attempts to apply psychological understandings in more progressive ways, often looking towards social change as a means of preventing and treating psychopathology.
Critical psychologists believe conventional psychology fails to consider how power differences between social classes and groups can impact an individual’s or a group's mental and physical well-being. Conventional psychology does this, in part, by explaining behavior at the individual level.
Criticisms of mainstream psychology consistent with current critical psychology usage have existed since psychology's modern development in the late 19th century. Use of the term "critical psychology" started in the 1970s in Berlin at Freie Universität Berlin. The German branch of critical psychology predates and has developed largely separately from the rest of the field. As of May 2007, only a few works have been translated into English. The German Critical Psychology movement is rooted in the post-war babyboomers' student revolt of the late '60s; see German student movement. Marx's "Critique of Political Economy" played an important role in the German branch of the student revolt, which was centered in Berlin. Then Berlin was a capitalist city surrounded by communist-ruled East Germany, represented a "hot spot" of political and ideological controversy for the revolutionary German students. The sociological foundations of critical psychology are decidedly Marxist.
One of the most important and sophisticated books in the field is the "Grundlegung der Psychologie" ("Foundations of Psychology") by Klaus Holzkamp, who might be considered the theoretical founder of critical psychology. Holzkamp wrote two books on theory of science and one on sensory perception before publishing the "Grundlegung der Psychologie" in 1983. Holzkamp believed his work provided a solid paradigm for psychological research because viewed psychology as a pre-paradigmatic scientific discipline (T.S. Kuhn had used the term "pre-paradigmatic" for social science).
Holzkamp mostly based his sophisticated attempt to provide a comprehensive and integrated set of categories defining the field of psychological research on Aleksey Leontyev's approach to cultural–historical psychology and activity theory. Leontyev had seen human action as a result of biological as well as cultural evolution and, drawing on Marx's materialist conception of culture, stressed that individual cognition is always part of social action which in turn is mediated by man-made tools (cultural artifacts), language and other man-made systems of symbols, which he viewed as a major distinguishing feature of human culture and, thus, human cognition. Another important source was Lucien Séve's theory of personality, which provided the concept of "social activity matrices" as mediating structure between individual and social reproduction. At the same time, the "Grundlegung" systematically integrated previous specialized work done at Free University of Berlin in the '70s by critical psychologists who also had been influenced by Marx, Leontyev and Seve. This included books on animal behavior/ethology, sensory perception, motivation and cognition. He also incorporated ideas from Freud's psychoanalysis and Merleau-Ponty's phenomenology into his approach.
One core result of Holzkamp's historical and comparative analysis of human reproductive action, perception and cognition is a very specific concept of meaning that identifies symbolic meaning as historically and culturally constructed, purposeful conceptual structures that humans create in close relationship to material culture and within the context of historically specific formations of social reproduction.
Coming from this phenomenological perspective on culturally mediated and socially situated action, Holzkamp launched a devastating and original methodological attack on behaviorism (which he termed S–R (stimulus–response) psychology) based on linguistic analysis, showing in minute detail the rhetorical patterns by which this approach to psychology creates the illusion of "scientific objectivity" while at the same time losing relevance for understanding culturally situated, intentional human actions. Against this approach, he developed his own approach to generalization and objectivity, drawing on ideas from Kurt Lewin in Chapter 9 of "Grundlegung der Psychologie".
His last major publication before his death in 1995 was about learning. It appeared in 1993 and contained a phenomenological theory of learning from the standpoint of the subject. One important concept Holzkamp developed was "reinterpretation" of theories developed by conventional psychology. This meant to look at these concepts from the standpoint of the paradigm of critical psychology, thereby integrating their useful insights into critical psychology while at the same time identifying and criticizing their limiting implications, which in the case of S–R psychology were the rhetorical elimination of the subject and intentional action, and in the case of cognitive psychology which did take into account subjective motives and intentional actions, methodological individualism.
The first part of the book thus contains an extensive look at the history of psychological theories of learning and a minute re-interpretation of those concepts from the perspective of the paradigm of critical psychology, which focuses on intentional action situated in specific socio-historical/cultural contexts. The conceptions of learning he found most useful in his own detailed analysis of "classroom learning" came from cognitive anthropologists Jean Lave (situated learning) and Edwin Hutchins (distributed cognition).
The book's second part contained an extensive analysis on the modern state's institutionalized forms of "classroom learning" as the cultural–historical context that shapes much of modern learning and socialization. In this analysis, he heavily drew upon Michel Foucault's Discipline and Punish. Holzkamp felt that classroom learning as the historically specific form of learning does not make full use of student's potentials, but rather limits her or his learning potentials by a number of "teaching strategies." Part of his motivation for the book was to look for alternative forms of learning that made use of the enormous potential of the human psyche in more fruitful ways. Consequently, in the last section of the book, Holzkamp discusses forms of "expansive learning" that seem to avoid the limitations of classroom learning, such as apprenticeship and learning in contexts other than classrooms.
This search culminated in plans to write a major work on life leadership in the specific historical context of modern (capitalist) society. Due to his death in 1995, this work never got past the stage of early (and premature) conceptualizations, some of which were published in the journals "Forum Kritische Psychologie" and "Argument".
In the 1960s and 1970s the term "radical psychology" was used by psychologists to denote a branch of the field which rejected conventional psychology's focus on the individual as the basic unit of analysis and sole source of psychopathology. Instead, radical psychologists examined the role of society in causing and treating problems and looked towards social change as an alternative to therapy to treat mental illness and as a means of preventing psychopathology. Within psychiatry the term "anti-psychiatry" was often used and now British activists prefer the term "critical psychiatry". "Critical psychology" is currently the preferred term for the discipline of psychology keen to find alternatives to the way the discipline of psychology reduces human experience to the level of the individual and thereby strips away possibilities for radical social change.
Starting in the 1990s a new wave of books started to appear on critical psychology, the most influential being the edited book "Critical Psychology" by Dennis Fox and Isaac Prilleltensky. Various introductory texts to critical psychology written in the United Kingdom have tended to focus on discourse, but this has been seen by some proponents of critical psychology as a reduction of human experience to language which is as politically dangerous as the way mainstream psychology reduces experience to the individual mind. Attention to language and ideological processes, others would argue, is essential to effective critical psychology - it is not simply a matter of applying mainstream psychological concepts to issues of social change.
In 1999 Ian Parker published an influential manifesto in both the online journal "Radical Psychology" and the Annual Review of Critical Psychology. This manifesto argues that critical psychology should include the following four components:
There are a few international journals devoted to critical psychology, including the no longer published "International Journal of Critical Psychology" (continued in the journal Subjectivity) and the "Annual Review of Critical Psychology". The journals still tend to be directed to an academic audience, though the "Annual Review of Critical Psychology" runs as an open-access online journal. There are close links between critical psychologists and critical psychiatrists in Britain through the Asylum Collective. David Smail was one of the founders of The Midlands Psychology Group, a critical psychology collective who produced a manifesto for a social materialist psychology of distress. Critical psychology courses and research concentrations are available at Manchester Metropolitan University, York St Johns University, the University of East London, the University of Edinburgh, the University of KwaZulu Natal, the Graduate Center of the City University of New York, and the University of West Georgia. Undergraduate concentrations can also be found at the California Institute of Integral Studies and Prescott College.
Like many critical applications, critical psychology has expanded beyond Marxist and feminist roots to benefit from other critical approaches. Consider ecopsychology and transpersonal psychology. Critical psychology and related work has also sometimes been labelled radical psychology and liberation psychology. In the field of developmental psychology, the work of Erica Burman has been influential.
Various sub-disciplines within psychology have begun to establish their own critical orientations. Perhaps the most extensive are critical health psychology and community psychology.
An early international overview of critical psychology perspectives can be found in Critical Psychology: Voices for Change, edited by Tod Sloan (Macmillan, 2000). In 2015, Ian Parker edited the Handbook of Critical Psychology.
At FU-Berlin, critical psychology was not really seen as a division of psychology and followed its own methodology, trying to reformulate traditional psychology on an unorthodox Marxist base and drawing from Soviet ideas of cultural–historical psychology, particularly Aleksey Leontyev. Some years ago the department of critical psychology at FU-Berlin was merged into the traditional psychology department.
An April 2009 issue of the Sage journal "Theory & Psychology" (edited by Desmond Painter, Athanasios Marvakis, and Leendert Mos) is devoted to an examination of German critical psychology.
The University of KwaZulu-Natal in Durban, South Africa, is one of few worldwide to offer a Master's course in critical psychology. For an overview of critical psychology in South Africa, see Desmond Painter and Martin Terre Blanche's article on "Critical Psychology in South Africa: Looking back and looking forwards". They have also now started a critical psychology blog.
Critical psychology in the United States and Canada has, for the most part, focused on critiques of mainstream psychology's support for an unjust "status quo". No departments of critical psychology exist, with the exception of the Bachelor's Completion Program with a minor in Critical Psychology, offered at the California Institute of Integral Studies in San Francisco, though critical perspectives are sometimes encountered in traditional universities, perhaps especially within community psychology programs. The University of West Georgia offers a Ph.D. in Consciousness and Society with critical psychology being one of the main three theoretical orientations. North American efforts include the 1993 founding of RadPsyNet, the 1997 publication of "Critical Psychology: An Introduction" (edited by Dennis Fox and Isaac Prilleltensky; expanded 2009 edition edited by Dennis Fox, Isaac Prilleltensky, and Stephanie Austin), the 2001 Monterey Conference on Critical Psychology, and in underlying themes of many contributions to the "Journal of Social Action in Counseling and Psychology". | https://en.wikipedia.org/wiki?curid=7801 |
Crossfire
A crossfire (also known as interlocking fire) is a military term for the siting of weapons (often automatic weapons such as assault rifles or sub-machine guns) so that their arcs of fire overlap. This tactic came to prominence in World War I.
Siting weapons this way is an example of the application of the defensive principle of "mutual support". The advantage of siting weapons that mutually support one another is that it is difficult for an attacker to find a covered approach to any one defensive position.
Use of armour, air support, indirect fire support, and stealth are tactics that may be used to assault a defensive position. However, when combined with land mines, snipers, barbed wire, and air cover, crossfire became a difficult tactic to counter in the early 20th century.
The tactic of using overlapping arcs of fire came to prominence during World War I where it was a feature of trench warfare. Machine guns were placed in groups, called machine-gun nests, and they protected the front of the trenches. Many lives were lost in futile attempts to charge across the no man's land where these crossfires were set up. After these attacks many bodies could be found in the no man's land.
To be "caught in the crossfire" is an expression that often refers to unintended casualties (bystanders, etc.) who were killed or wounded by being exposed to the gunfire of a battle or gun fight, such as in a position to be hit by bullets of either side. The phrase has come to mean any injury, damage or harm (physical or otherwise) caused to a third party due to the action of belligerents (collateral damage). | https://en.wikipedia.org/wiki?curid=7803 |
Cruising (maritime)
Cruising by boat is a lifestyle that involves living for extended time on a vessel while traveling from place to place for pleasure. Cruising generally refers to trips of a few days or more, and can extend to round-the-world voyages.
Boats were almost exclusively used for working purposes prior to the nineteenth century. In 1857, the philosopher Henry David Thoreau, with his book "Canoeing in Wilderness" chronicling his canoe voyaging in the wilderness of Maine, was the first to convey the enjoyment of spiritual and lifestyle aspects of cruising.
The modern conception of cruising for pleasure was first popularised by the Scottish explorer and sportsman John MacGregor. He was introduced to the canoes and kayaks of the Native Americans on a camping trip in 1858, and on his return to the United Kingdom constructed his own 'double-ended' canoe in Lambeth. The boat, nicknamed 'Rob Roy' after a famous relative of his, was built of lapstrake oak planking, decked in cedar covered with rubberized canvas with an open cockpit in the center. He cruised around the waterways of Britain, Europe and the Middle East and wrote a popular book about his experiences, "A Thousand Miles in the Rob Roy Canoe".
In 1866, Macgregor was a moving force behind the establishment of the Royal Canoe Club, the first club in the world to promote pleasure cruising. The first recorded regatta was held on April 27, 1867, and it received Royal patronage in 1873. The latter part of the century saw cruising for leisure being enthusiastically taken up by the middle class. The author Robert Louis Stevenson wrote "An Inland Voyage" in 1877 as a travelogue on his canoeing trip through France and Belgium. Stevenson and his companion, Sir Walter Grindlay Simpson travelled in two 'Rob Roys' along the Oise River and witnessed the Romantic beauty of rural Europe.
The Canadian-American Joshua Slocum was one of the first people to carry out a long-distance sailing voyage for pleasure, circumnavigating the world between 1895 and 1898. Despite opinion that such a voyage was impossible, Slocum rebuilt a derelict sloop "Spray" and sailed her single-handed around the world. His book "Sailing Alone Around the World" was a classic adventure, and inspired many others to take to the seas.
Other cruising authors have provided both inspiration and instruction to prospective cruisers. Key among these during the post World War II period are Electa and Irving Johnson, Miles and Beryl Smeeton, Bernard Moitessier, Peter Pye, and Eric and Susan Hiscock. During the 1970s - 1990s Robin Lee Graham, Lin and Larry Pardey, Annie Hill, Herb Payson, Linda and Steve Dashew, Margaret and Hal Roth, and Beth Leonard & Evans Starzinger have provided inspiration for people to set off voyaging.
The development of ocean crossing rallies, most notably the ARC (Atlantic Rally for Cruisers), have encouraged less experienced sailors to undertake ocean crossings. These rallies provide a group of sailors crossing the same ocean at the same time with safety inspections, weather information and social functions.
Cruising is done on both sail and power boats, monohulls and multihulls although sail predominates over longer distances, as ocean-going power boats are considerably more expensive to purchase and operate. The size of the typical cruising boat has increased over the years and is currently in the range of 10 to 15 metres (33 to 50 feet) although smaller boats have been used in around-the-world trips, but are generally not recommended given the dangers involved. Many cruisers are "long term" and travel for many years, the most adventurous among them circle the globe over a period of three to ten years. Many others take a year or two off from work and school for shorter trips and the chance to experience the cruising lifestyle.
Blue-water cruising is more involved and inherently more dangerous than coastal cruising.
Before embarking on an open-ocean voyage, planning and preparation will include studying charts, weather reports/warnings, almanacs and navigation books of the route to be followed. In addition, supplies need to be stocked (including fresh water and fuel), navigation instruments checked and the ship itself needs to be inspected and the crew needs to be given exact instruction on the jobs are expected to perform (e.g. the watch, which is generally 4 hours on and 4 hours off, navigation, steering, rigging sails, ...). In addition, the crew needs to be well trained at working together and with the ship in question. Finally, the sailor must be mentally prepared for dealing with harsh situations. There have been many well-documented cases where sailors had to be rescued simply because they were not sufficiently prepared (the sailors as well as the ship) or lacked experience for their venture and ran into serious trouble.
Sailing near the coast (coastal cruising) gives a certain amount of safety. A ship is always granted 'innocent passage' through the country (most countries usually claim up to off the coast). When this method is practiced however, if the ship needs to stop (e.g. for repairs), a trip to a customs checkpoint to have passports checked would be required.
Cruisers use a variety of equipment and techniques to make their voyages possible, or simply more comfortable.
The use of wind vane self steering was common on long distance cruising yachts but is increasingly being supplemented or replaced by electrical auto-pilots.
Though in the past many cruisers had no means of generating electricity on board and depended on kerosene and dry-cell batteries, today electrical demands are much higher and nearly all cruisers have electrical devices such as lights, communications equipment and refrigeration. Although most boats can generate power from their inboard engines, an increasing number carry auxiliary generators. Carrying sufficient fuel to power engine and generator over a long voyage can be a problem, so many cruising boats are equipped with other ancillary generating devices such as solar panels, wind turbines and towed turbines. Cruisers choosing to spend extended time in very remote locations with minimal access to marinas can opt to equip their vessels with watermakers (reverse-osmosis seawater desalination units) used to convert sea water to potable fresh water.
Satellite communications are becoming more common on cruising boats. Many boats are now equipped with satellite telephone systems; however, these systems can be expensive to use, and may operate only in certain areas. Many cruisers still use short wave maritime SSB and amateur radio, which has no running costs. These radios provide two-way voice communications, can receive weather fax graphics or GRIB files via a laptop computer, and with a compatible modem (e.g. PACTOR) can send and receive email at very slow speed. Such emails are usually limited to basic communication using plain text, without HTML formatting or attachments.
Awareness of impending weather conditions is particularly important to cruising sailors who are often far from safe harbours and need to steer clear of dangerous weather conditions. Most cruising boats are equipped with a barometer or a weather station that records barometric pressure as well as temperature and provides rudimentary forecasting. For more sophisticated weather forecasting, cruisers rely on their ability to receive forecasts by radio, phone or satellite.
In order to avoid collisions with other vessels, cruisers rely on a maintaining a regular watch schedule. At night, color-coded running lights help determine the position and orientation of vessels. Radar and AIS systems are often employed to detect vessels positions and movement in all conditions (day, night, rain and fog).
Cruisers navigate using paper charts and radar. Modern yachts are often also equipped with a chartplotter which enables the use of electronic charts and is linked to GPS satellites that provide position reports. Some chartplotters have the ability to interface charts and radar images. Those that still wish to work with traditional charts as well as with GPS may do so using a Yeoman Plotter. Certain advanced sailing vessels have a completely automated sailing system which includes a plotter, as well as course correcting through a link with the ship's steering organs (e.g. sails, propeller). One such device can be found at the Maltese Falcon.
Purchasing and maintaining a yacht can be costly. Most cruising sailors do not own a house and consider their boat their home during the duration of their cruise. Many cruisers find they spend, on average, 4% of their boat's purchase price annually on boat maintenance.
Like living a conventional life on land, the cost of cruising is variable. How much a person ends up spending depends largely on their spending habits (for example, eating out a lot and frequenting marinas vs. preparing local foods aboard and anchoring out) and the type of boat (fancy modern production boats are very expensive to purchase and maintain, while low-key cruising boats often involve much lower expenses). Most long-term cruisers prefer to live a simple life, usually with far lower expenses than people who live ashore.
An alternative solution is to sail on someone else's yacht. Those who know how to sail can sometimes find boats looking for an extra crewmember for a long trip, while some non-sailors are also able to find boats willing to carry a hitch-hiker. Crew-finding websites exist to help match-up people looking for a crossing with yachts with a berth available or looking for a temporary crewmember, Find a Crew for example. Another common tactic for finding a yacht is to visit local yacht clubs and marinas and get to know the sailors there, in the hope that one of them will be able to provide a berth.
Travel by water brings hazards: collision, weather, and equipment failure can lead to dangerous situations such as a sinking or severely disabled and dangerous vessel. For this reason many long distance cruising yachts carry with them emergency equipment such as SARTs, EPIRBs and liferafts or proactive lifeboats. Medical emergencies are also of concern, as a medical emergency can occur on a long passage when the closest port is over a week away. For this reason before going cruising many people go through first aid training and carry medical kits. In some parts of the world (e.g., near the Horn of Africa) piracy can be a problem. | https://en.wikipedia.org/wiki?curid=7806 |
Cavitation
Cavitation is a phenomenon in which rapid changes of pressure in a liquid lead to the formation of small vapor-filled cavities in places where the pressure is relatively low.
When subjected to higher pressure, these cavities, called "bubbles" or "voids", collapse and can generate a shock wave that is strong very close to the bubble, but rapidly weakens as it propagates away from the bubble.
Cavitation is a significant cause of wear in some engineering contexts. Collapsing voids that implode near to a metal surface cause cyclic stress through repeated implosion. This results in surface fatigue of the metal causing a type of wear also called "cavitation". The most common examples of this kind of wear are to pump impellers, and bends where a sudden change in the direction of liquid occurs. Cavitation is usually divided into two classes of behavior: inertial (or transient) cavitation and non-inertial cavitation.
The process in which a void or bubble in a liquid rapidly collapses, producing a shock wave, is called inertial cavitation. Inertial cavitation occurs in nature in the strikes of mantis shrimps and pistol shrimps, as well as in the vascular tissues of plants. In man-made objects, it can occur in control valves, pumps, propellers and impellers.
Non-inertial cavitation is the process in which a bubble in a fluid is forced to oscillate in size or shape due to some form of energy input, such as an acoustic field. Such cavitation is often employed in ultrasonic cleaning baths and can also be observed in pumps, propellers, etc.
Since the shock waves formed by collapse of the voids are strong enough to cause significant damage to parts, cavitation is typically an undesirable phenomenon in machinery (although desirable if intentionally used, for example, to sterilize contaminated surgical instruments, break down pollutants in water purification systems, emulsify tissue for cataract surgery or kidney stone lithotripsy, or homogenize fluids). It is very often specifically avoided in the design of machines such as turbines or propellers, and eliminating cavitation is a major field in the study of fluid dynamics. However, it is sometimes useful and does not cause damage when the bubbles collapse away from machinery, such as in supercavitation.
Inertial cavitation was first observed in the late 19th century, considering the collapse of a spherical void within a liquid. When a volume of liquid is subjected to a sufficiently low pressure, it may rupture and form a cavity. This phenomenon is coined "cavitation inception" and may occur behind the blade of a rapidly rotating propeller or on any surface vibrating in the liquid with sufficient amplitude and acceleration. A fast-flowing river can cause cavitation on rock surfaces, particularly when there is a drop-off, such as on a waterfall.
Other ways of generating cavitation voids involve the local deposition of energy, such as an intense focused laser pulse (optic cavitation) or with an electrical discharge through a spark. Vapor gases evaporate into the cavity from the surrounding medium; thus, the cavity is not a perfect vacuum, but has a relatively low gas pressure. Such a low-pressure bubble in a liquid begins to collapse due to the higher pressure of the surrounding medium. As the bubble collapses, the pressure and temperature of the vapor within increases. The bubble eventually collapses to a minute fraction of its original size, at which point the gas within dissipates into the surrounding liquid via a rather violent mechanism which releases a significant amount of energy in the form of an acoustic shock wave and as visible light. At the point of total collapse, the temperature of the vapor within the bubble may be several thousand kelvin, and the pressure several hundred atmospheres.
Inertial cavitation can also occur in the presence of an acoustic field. Microscopic gas bubbles that are generally present in a liquid will be forced to oscillate due to an applied acoustic field. If the acoustic intensity is sufficiently high, the bubbles will first grow in size and then rapidly collapse. Hence, inertial cavitation can occur even if the rarefaction in the liquid is insufficient for a Rayleigh-like void to occur. High-power ultrasonics usually utilize the inertial cavitation of microscopic vacuum bubbles for treatment of surfaces, liquids, and slurries.
The physical process of cavitation inception is similar to boiling. The major difference between the two is the thermodynamic paths that precede the formation of the vapor. Boiling occurs when the local temperature of the liquid reaches the saturation temperature, and further heat is supplied to allow the liquid to sufficiently phase change into a gas. Cavitation inception occurs when the local pressure falls sufficiently far below the saturated vapor pressure, a value given by the tensile strength of the liquid at a certain temperature.
In order for cavitation inception to occur, the cavitation "bubbles" generally need a surface on which they can nucleate. This surface can be provided by the sides of a container, by impurities in the liquid, or by small undissolved microbubbles within the liquid. It is generally accepted that hydrophobic surfaces stabilize small bubbles. These pre-existing bubbles start to grow unbounded when they are exposed to a pressure below the threshold pressure, termed Blake's threshold.
The vapor pressure here differs from the meteorological definition of vapor pressure, which describes the partial pressure of water in the atmosphere at some value less than 100% saturation. Vapor pressure as relating to cavitation refers to the vapor pressure in equilibrium conditions and can therefore be more accurately defined as the equilibrium (or saturated) vapor pressure.
Non-inertial cavitation is the process in which small bubbles in a liquid are forced to oscillate in the presence of an acoustic field, when the intensity of the acoustic field is insufficient to cause total bubble collapse. This form of cavitation causes significantly less erosion than inertial cavitation, and is often used for the cleaning of delicate materials, such as silicon wafers.
Hydrodynamic cavitation describes the process of vaporisation, bubble generation and bubble implosion which occurs in a flowing liquid as a result of a decrease and subsequent increase in local pressure. Cavitation will only occur if the local pressure declines to some point below the saturated vapor pressure of the liquid and subsequent recovery above the vapor pressure. If the recovery pressure is not above the vapor pressure then flashing is said to have occurred. In pipe systems, cavitation typically occurs either as the result of an increase in the kinetic energy (through an area constriction) or an increase in the pipe elevation.
Hydrodynamic cavitation can be produced by passing a liquid through a constricted channel at a specific flow velocity or by mechanical rotation of an object through a liquid. In the case of the constricted channel and based on the specific (or unique) geometry of the system, the combination of pressure and kinetic energy can create the hydrodynamic cavitation cavern downstream of the local constriction generating high energy cavitation bubbles.
The process of bubble generation, and the subsequent growth and collapse of the cavitation bubbles, results in very high energy densities and in very high local temperatures and local pressures at the surface of the bubbles for a very short time. The overall liquid medium environment, therefore, remains at ambient conditions. When uncontrolled, cavitation is damaging; by controlling the flow of the cavitation, however, the power can be harnessed and non-destructive. Controlled cavitation can be used to enhance chemical reactions or propagate certain unexpected reactions because free radicals are generated in the process due to disassociation of vapors trapped in the cavitating bubbles.
Orifices and venturi are reported to be widely used for generating cavitation. A venturi has an inherent advantage over an orifice because of its smooth converging and diverging sections, such that it can generate a higher flow velocity at the throat for a given pressure drop across it. On the other hand, an orifice has an advantage that it can accommodate a greater number of holes (larger perimeter of holes) in a given cross sectional area of the pipe.
The cavitation phenomenon can be controlled to enhance the performance of high-speed marine vessels and projectiles, as well as in material processing technologies, in medicine, etc. Controlling the cavitating flows in liquids can be achieved only by advancing the mathematical foundation of the cavitation processes. These processes are manifested in different ways, the most common ones and promising for control being bubble cavitation and supercavitation. The first exact classical solution should perhaps be credited to the well-known solution by Hermann von Helmholtz in 1868. The earliest distinguished studies of academic type on the theory of a cavitating flow with free boundaries and supercavitation were published in the book "Jets, wakes and cavities" followed by "Theory of jets of ideal fluid". Widely used in these books was the well-developed theory of conformal mappings of functions of a complex variable, allowing one to derive a large number of exact solutions of plane problems. Another venue combining the existing exact solutions with approximated and heuristic models was explored in the work "Hydrodynamics of Flows with Free Boundaries" that refined the applied calculation techniques based on the principle of cavity expansion independence, theory of pulsations and stability of elongated axisymmetric cavities, etc. and in "Dimensionality and similarity methods in the problems of the hydromechanics of vessels".
A natural continuation of these studies was recently presented in "The Hydrodynamics of Cavitating Flows" – an encyclopedic work encompassing all the best advances in this domain for the last three decades, and blending the classical methods of mathematical research with the modern capabilities of computer technologies. These include elaboration of nonlinear numerical methods of solving 3D cavitation problems, refinement of the known plane linear theories, development of asymptotic theories of axisymmetric and nearly axisymmetric flows, etc. As compared to the classical approaches, the new trend is characterized by expansion of the theory into the 3D flows. It also reflects a certain correlation with current works of an applied character on the hydrodynamics of supercavitating bodies.
Hydrodynamic cavitation can also improve some industrial processes. For instance, cavitated corn slurry shows higher yields in ethanol production compared to uncavitated corn slurry in dry milling facilities.
This is also used in the mineralization of bio-refractory compounds which otherwise would need extremely high temperature and pressure conditions since free radicals are generated in the process due to the dissociation of vapors trapped in the cavitating bubbles, which results in either the intensification of the chemical reaction or may even result in the propagation of certain reactions not possible under otherwise ambient conditions.
In industry, cavitation is often used to homogenize, or mix and break down, suspended particles in a colloidal liquid compound such as paint mixtures or milk. Many industrial mixing machines are based upon this design principle. It is usually achieved through impeller design or by forcing the mixture through an annular opening that has a narrow entrance orifice with a much larger exit orifice. In the latter case, the drastic decrease in pressure as the liquid accelerates into a larger volume induces cavitation. This method can be controlled with hydraulic devices that control inlet orifice size, allowing for dynamic adjustment during the process, or modification for different substances. The surface of this type of mixing valve, against which surface the cavitation bubbles are driven causing their implosion, undergoes tremendous mechanical and thermal localized stress; they are therefore often constructed of super-hard or tough materials such as stainless steel, Stellite, or even polycrystalline diamond (PCD).
Cavitating water purification devices have also been designed, in which the extreme conditions of cavitation can break down pollutants and organic molecules. Spectral analysis of light emitted in sonochemical reactions reveal chemical and plasma-based mechanisms of energy transfer. The light emitted from cavitation bubbles is termed sonoluminescence.
Use of this technology has been tried successfully in alkali refining of vegetable oils.
Hydrophobic chemicals are attracted underwater by cavitation as the pressure difference between the bubbles and the liquid water forces them to join together. This effect may assist in protein folding.
Cavitation plays an important role for the destruction of kidney stones in shock wave lithotripsy. Currently, tests are being conducted as to whether cavitation can be used to transfer large molecules into biological cells (sonoporation). Nitrogen cavitation is a method used in research to lyse cell membranes while leaving organelles intact.
Cavitation plays a key role in non-thermal, non-invasive fractionation of tissue for treatment of a variety of diseases and can be used to open the blood-brain barrier to increase uptake of neurological drugs in the brain.
Cavitation also plays a role in HIFU, a thermal non-invasive treatment methodology for cancer.
Ultrasound sometimes is used to increase bone formation, for instance in post-surgical applications.
It has been suggested that the sound of "cracking" knuckles derives from the collapse of cavitation in the synovial fluid within the joint. Movements that cause cracking expand the joint space, thus reducing pressure to the point of cavitation. It remains controversial whether this is associated with clinically significant joint injury such as osteoarthritis.
In industrial cleaning applications, cavitation has sufficient power to overcome the particle-to-substrate adhesion forces, loosening contaminants. The threshold pressure required to initiate cavitation is a strong function of the pulse width and the power input. This method works by generating acoustic cavitation in the cleaning fluid, picking up and carrying contaminant particles away in the hope that they do not reattach to the material being cleaned (which is a possibility when the object is immersed, for example in an ultrasonic cleaning bath). The same physical forces that remove contaminants also have the potential to damage the target being cleaned.
Cavitation has been applied to egg pasteurization. A hole-filled rotor produces cavitation bubbles, heating the liquid from within. Equipment surfaces stay cooler than the passing liquid, so eggs don't harden as they did on the hot surfaces of older equipment. The intensity of cavitation can be adjusted, making it possible to tune the process for minimum protein damage.
Cavitation is, in many cases, an undesirable occurrence. In devices such as propellers and pumps, cavitation causes a great deal of noise, damage to components, vibrations, and a loss of efficiency. Cavitation has also become a concern in the renewable energy sector as it may occur on the blade surface of tidal stream turbines.
When the cavitation bubbles collapse, they force energetic liquid into very small volumes, thereby creating spots of high temperature and emitting shock waves, the latter of which are a source of noise. The noise created by cavitation is a particular problem for military submarines, as it increases the chances of being detected by passive sonar.
Although the collapse of a small cavity is a relatively low-energy event, highly localized collapses can erode metals, such as steel, over time. The pitting caused by the collapse of cavities produces great wear on components and can dramatically shorten a propeller's or pump's lifetime.
After a surface is initially affected by cavitation, it tends to erode at an accelerating pace. The cavitation pits increase the turbulence of the fluid flow and create crevices that act as nucleation sites for additional cavitation bubbles. The pits also increase the components' surface area and leave behind residual stresses. This makes the surface more prone to stress corrosion.
Major places where cavitation occurs are in pumps, on propellers, or at restrictions in a flowing liquid.
As an impeller's (in a pump) or propeller's (as in the case of a ship or submarine) blades move through a fluid, low-pressure areas are formed as the fluid accelerates around and moves past the blades. The faster the blade moves, the lower the pressure can become around it. As it reaches vapor pressure, the fluid vaporizes and forms small bubbles of gas. This is cavitation. When the bubbles collapse later, they typically cause very strong local shock waves in the fluid, which may be audible and may even damage the blades.
Cavitation in pumps may occur in two different forms:
Suction cavitation occurs when the pump suction is under a low-pressure/high-vacuum condition where the liquid turns into a vapor at the eye of the pump impeller. This vapor is carried over to the discharge side of the pump, where it no longer sees vacuum and is compressed back into a liquid by the discharge pressure. This imploding action occurs violently and attacks the face of the impeller. An impeller that has been operating under a suction cavitation condition can have large chunks of material removed from its face or very small bits of material removed, causing the impeller to look spongelike. Both cases will cause premature failure of the pump, often due to bearing failure. Suction cavitation is often identified by a sound like gravel or marbles in the pump casing.
Common causes of suction cavitation can include clogged filters, pipe blockage on the suction side, poor piping design, pump running too far right on the pump curve, or conditions not meeting NPSH (net positive suction head) requirements.
In automotive applications, a clogged filter in a hydraulic system (power steering, power brakes) can cause suction cavitation making a noise that rises and falls in synch with engine RPM. It is fairly often a high pitched whine, like set of nylon gears not quite meshing correctly.
Discharge cavitation occurs when the pump discharge pressure is extremely high, normally occurring in a pump that is running at less than 10% of its best efficiency point. The high discharge pressure causes the majority of the fluid to circulate inside the pump instead of being allowed to flow out the discharge. As the liquid flows around the impeller, it must pass through the small clearance between the impeller and the pump housing at extremely high flow velocity. This flow velocity causes a vacuum to develop at the housing wall (similar to what occurs in a venturi), which turns the liquid into a vapor. A pump that has been operating under these conditions shows premature wear of the impeller vane tips and the pump housing. In addition, due to the high pressure conditions, premature failure of the pump's mechanical seal and bearings can be expected. Under extreme conditions, this can break the impeller shaft.
Discharge cavitation in joint fluid is thought to cause the popping sound produced by bone joint cracking, for example by deliberately cracking one's knuckles.
Since all pumps require well-developed inlet flow to meet their potential, a pump may not perform or be as reliable as expected due to a faulty suction piping layout such as a close-coupled elbow on the inlet flange. When poorly developed flow enters the pump impeller, it strikes the vanes and is unable to follow the impeller passage. The liquid then separates from the vanes causing mechanical problems due to cavitation, vibration and performance problems due to turbulence and poor filling of the impeller. This results in premature seal, bearing and impeller failure, high maintenance costs, high power consumption, and less-than-specified head and/or flow.
To have a well-developed flow pattern, pump manufacturer's manuals recommend about (10 diameters?) of straight pipe run upstream of the pump inlet flange. Unfortunately, piping designers and plant personnel must contend with space and equipment layout constraints and usually cannot comply with this recommendation. Instead, it is common to use an elbow close-coupled to the pump suction which creates a poorly developed flow pattern at the pump suction.
With a double-suction pump tied to a close-coupled elbow, flow distribution to the impeller is poor and causes reliability and performance shortfalls. The elbow divides the flow unevenly with more channeled to the outside of the elbow. Consequently, one side of the double-suction impeller receives more flow at a higher flow velocity and pressure while the starved side receives a highly turbulent and potentially damaging flow. This degrades overall pump performance (delivered head, flow and power consumption) and causes axial imbalance which shortens seal, bearing and impeller life.
To overcome cavitation:
Increase suction pressure if possible.
Decrease liquid temperature if possible.
Throttle back on the discharge valve to decrease flow-rate.
Vent gases off the pump casing.
Cavitation can occur in control valves. If the actual pressure drop across the valve as defined by the upstream and downstream pressures in the system is greater than the sizing calculations allow, pressure drop flashing or cavitation may occur. The change from a liquid state to a vapor state results from the increase in flow velocity at or just downstream of the greatest flow restriction which is normally the valve port. To maintain a steady flow of liquid through a valve the flow velocity must be greatest at the vena contracta or the point where the cross sectional area is the smallest. This increase in flow velocity is accompanied by a substantial decrease in the fluid pressure which is partially recovered downstream as the area increases and flow velocity decreases. This pressure recovery is never completely to the level of the upstream pressure. If the pressure at the vena contracta drops below the vapor pressure of the fluid bubbles will form in the flow stream. If the pressure recovers after the valve to a pressure that is once again above the vapor pressure, then the vapor bubbles will collapse and cavitation will occur.
When water flows over a dam spillway, the irregularities on the spillway surface will cause small areas of flow separation in a high-speed flow, and, in these regions, the pressure will be lowered. If the flow velocities are high enough the pressure may fall to below the local vapor pressure of the water and vapor bubbles will form. When these are carried downstream into a high pressure region the bubbles collapse giving rise to high pressures and possible cavitation damage.
Experimental investigations show that the damage on concrete chute and tunnel spillways can start at clear water flow velocities of between , and, up to flow velocities of , it may be possible to protect the surface by streamlining the boundaries, improving the surface finishes or using resistant materials.
When some air is present in the water the resulting mixture is compressible and this damps the high pressure caused
by the bubble collapses. If the flow velocities near the spillway invert are sufficiently high, aerators (or aeration devices) must be introduced to prevent cavitation. Although these have been installed for some years, the mechanisms of air entrainment at the aerators and the slow movement of the air away from the spillway surface are still challenging.
The spillway aeration device design is based upon a small deflection of the spillway bed (or sidewall) such as a ramp and offset to deflect the high flow velocity flow away from the spillway surface. In the cavity formed below the nappe, a local subpressure beneath the nappe is produced by which air is sucked into the flow. The complete design includes the deflection device (ramp, offset) and the air supply system.
Some larger diesel engines suffer from cavitation due to high compression and undersized cylinder walls. Vibrations of the cylinder wall induce alternating low and high pressure in the coolant against the cylinder wall. The result is pitting of the cylinder wall, which will eventually let cooling fluid leak into the cylinder and combustion gases to leak into the coolant.
It is possible to prevent this from happening with the use of chemical additives in the cooling fluid that form a protective layer on the cylinder wall. This layer will be exposed to the same cavitation, but rebuilds itself. Additionally a regulated overpressure in the cooling system (regulated and maintained by the coolant filler cap spring pressure) prevents the forming of cavitation.
From about the 1980s, new designs of smaller gasoline engines also displayed cavitation phenomena. One answer to the need for smaller and lighter engines was a smaller coolant volume and a correspondingly higher coolant flow velocity. This gave rise to rapid changes in flow velocity and therefore rapid changes of static pressure in areas of high heat transfer. Where resulting vapor bubbles collapsed against a surface, they had the effect of first disrupting protective oxide layers (of cast aluminium materials) and then repeatedly damaging the newly formed surface, preventing the action of some types of corrosion inhibitor (such as silicate based inhibitors). A final problem was the effect that increased material temperature had on the relative electrochemical reactivity of the base metal and its alloying constituents. The result was deep pits that could form and penetrate the engine head in a matter of hours when the engine was running at high load and high speed. These effects could largely be avoided by the use of organic corrosion inhibitors or (preferably) by designing the engine head in such a way as to avoid certain cavitation inducing conditions.
Some hypotheses relating to diamond formation posit a possible role for cavitation—namely cavitation in the kimberlite pipes providing the extreme pressure needed to change pure carbon into the rare allotrope that is diamond.
The loudest three sounds ever recorded, during the 1883 eruption of Krakatoa, are now understood as the bursts of three huge cavitation bubbles, each larger than the last, formed in the volcano's throat. Rising magma, filled with dissolved gasses and under immense pressure, encountered a different magma that compressed easily, allowing bubbles to grow and combine.
There exist macroscopic white lamellae inside quartz and other minerals in the Bohemian Massif resembling wavefronts generated by a meteorite impact according to the Rajlich's Hypothesis. The hypothetical wavefronts are composed of many microcavities. Their origin is seen in a physical phenomenon of ultrasonic cavitation.
Cavitation occurs in the xylem of vascular plants when the tension of water within the xylem exceeds atmospheric pressure. The sap vaporizes locally so that either the vessel elements or tracheids are filled with water vapor. Plants are able to repair cavitated xylem in a number of ways. For plants less than 50 cm tall, root pressure can be sufficient to redissolve the vapor. Larger plants direct solutes into the xylem via "ray cells", or in tracheids, via osmosis through bordered pits. Solutes attract water, the pressure rises and vapor can redissolve. In some trees, the sound of the cavitation is audible, particularly in summer, when the rate of evapotranspiration is highest. Some deciduous trees have to shed leaves in the autumn partly because cavitation increases as temperatures decrease.
Cavitation plays a fundamental role in spore dispersal mechanism of particular types of plants. Fern provides a clear example. Namely, the fern sporangium acts as a catapult. The opening phase is driven by water vaporization and by the resulting pressure decrease inside annulus cells (that is the charging phase of the catapult). When the negative pressure approximately reaches the value of 9 MPa, cavitation occurs. This rapid event triggers the spore dispersal due to the elastic energy released by the annulus structure (that is the discharging phase of the catapult). The initial spores acceleration is significantly high (up to formula_1 times the gravitational acceleration).
Just as cavitation bubbles form on a fast-spinning boat propeller, they may also form on the tails and fins of aquatic animals. This primarily occurs near the surface of the ocean, where the ambient water pressure is low.
Cavitation may limit the maximum swimming speed of powerful swimming animals like dolphins and tuna. Dolphins may have to restrict their speed because collapsing cavitation bubbles on their tail are painful. Tuna have bony fins without nerve endings and do not feel pain from cavitation. They are slowed down when cavitation bubbles create a vapor film around their fins. Lesions have been found on tuna that are consistent with cavitation damage.
Some sea animals have found ways to use cavitation to their advantage when hunting prey. The pistol shrimp snaps a specialized claw to create cavitation, which can kill small fish. The mantis shrimp (of the "smasher" variety) uses cavitation as well in order to stun, smash open, or kill the shellfish that it feasts upon.
Thresher sharks use 'tail slaps' to debilitate their small fish prey and cavitation bubbles have been seen rising from the apex of the tail arc.
In the last half-decade, coastal erosion in the form of inertial cavitation has been generally accepted. Bubbles in an incoming wave are forced into cracks in the cliff being eroded. Varying pressure decompresses some vapor pockets which subsequently implode. The resulting pressure peaks can blast apart fractions of the rock.
As early as 1754, the Swiss mathematician Leonhard Euler (1707–1783) speculated about the possibility of cavitation. In 1859, the English mathematician William Henry Besant (1828–1917) published a solution to the problem of the dynamics of the collapse of a spherical cavity in a fluid, which had been presented by the Anglo-Irish mathematician George Stokes (1819–1903) as one the Cambridge [University] Senate-house problems and riders for the year 1847. In 1894, Irish fluid dynamicist Osborne Reynolds (1842–1912) studied the formation and collapse of vapor bubbles in boiling liquids and in constricted tubes. | https://en.wikipedia.org/wiki?curid=7807 |
Church of the Holy Sepulchre
The Church of the Holy Sepulchre (, , , ) is a church in the Christian Quarter of the Old City of Jerusalem. The church contains, according to traditions dating back to at least the fourth century, the two holiest sites in Christianity: the site where Jesus was crucified, at a place known as Calvary or Golgotha, and Jesus's empty tomb, where he was buried and resurrected. The tomb is enclosed by a 19th-century shrine called the Aedicula. The Status Quo, an understanding between religious communities dating to 1757, applies to the site.
Within the church proper are the last four (or, by some definitions, five) stations of the Via Dolorosa, representing the final episodes of the Passion of Jesus. The church has been a major Christian pilgrimage destination since its creation in the fourth century, as the traditional site of the resurrection of Christ, thus its original Greek name, Church of the Anastasis ('Resurrection').
Today, the wider complex around the Church of the Holy Sepulchre also serves as the headquarters of the Greek Orthodox Patriarch of Jerusalem, while control of the church itself is shared among several Christian denominations and secular entities in complicated arrangements essentially unchanged for over 160 years, and some for much longer. The main denominations sharing property over parts of the church are the Greek Orthodox, Roman Catholic and Armenian Apostolic, and to a lesser degree the Coptic Orthodox, Syriac Orthodox and Ethiopian Orthodox.
The Church of the Holy Sepulchre(); is also called the "Church of the Resurrection" or "Church of the Anastasis" by Eastern Christians ( "Kanīsatu al-Qiyāmah"; "Naos tes Anastaseos"; "Surb Harut'yan tač̣ar").
Following the siege of AD 70 during the First Jewish–Roman War, Jerusalem had been reduced to ruins. In AD 130, the Roman emperor Hadrian began the building of a Roman colony, the new city of "Aelia Capitolina", on the site. Circa AD 135, he ordered that a cave containing a rock-cut tomb be filled in to create a flat foundation for a temple dedicated to Jupiter or Venus. The temple remained until the early 4th century.
After seeing a vision of a cross in the sky in 312, Constantine the Great converted to Christianity, signed the Edict of Milan legalising the religion, and sent his mother Helena to Jerusalem to look for Christ's tomb. With the help of Bishop of Caesarea Eusebius and Bishop of Jerusalem Macarius, three crosses were found near a tomb, leading the Romans to believe that they had found Calvary. Constantine ordered in about 326 that the temple to Jupiter/Venus be replaced by a church. After the temple was torn down and its ruins removed, the soil was removed from the cave, revealing a rock-cut tomb that Helena and Macarius identified as the burial site of Jesus, around which a shrine was constructed. In 327, Constantine and Helena separately commissioned the Church of the Nativity in Bethlehem to commemorate the birth of Jesus.
The Church of the Holy Sepulchre was built as separate constructs over the two holy sites: the great basilica (the "Martyrium" visited by Egeria in the 380s), an enclosed colonnaded atrium (the "Triportico") with the traditional site of Calvary in one corner, and across a courtyard, a rotunda called the "Anastasis" ("Resurrection"), where Helena and Macarius believed Jesus to have been buried.
The church was consecrated on 13 September 335. Every year, the Eastern Orthodox Church celebrates the anniversary of the .
This building was destroyed by a fire in May of AD 614, when the Sassanid Empire, under Khosrau II, invaded Jerusalem and captured the True Cross. In 630, the Emperor Heraclius rebuilt the church after recapturing the city. After Jerusalem came under Arab rule, it remained a Christian church, with the early Muslim rulers protecting the city's Christian sites, prohibiting their destruction or use as living quarters. A story reports that the Caliph Umar ibn al-Khattab visited the church and stopped to pray on the balcony, but at the time of prayer, turned away from the church and prayed outside. He feared that future generations would misinterpret this gesture, taking it as a pretext to turn the church into a mosque. Eutychius added that Umar wrote a decree prohibiting Muslims from praying at this location. The building suffered severe damage from an earthquake in 746.
Early in the ninth century, another earthquake damaged the dome of the Anastasis. The damage was repaired in 810 by Patriarch Thomas. In 841, the church suffered a fire. In 935, the Orthodox Christians prevented the construction of a Muslim mosque adjacent to the Church. In 938, a new fire damaged the inside of the basilica and came close to the rotunda. In 966, due to a defeat of Muslim armies in the region of Syria, a riot broke out, which was followed by reprisals. The basilica was burned again. The doors and roof were burnt, and the Patriarch John VII was murdered.
On 18 October 1009, Fatimid caliph Al-Hakim bi-Amr Allah ordered the complete destruction of the church as part of a more general campaign against Christian places of worship in Palestine and Egypt. The damage was extensive, with few parts of the early church remaining, and the roof of the rock-cut tomb damaged; the original shrine was destroyed. Some partial repairs followed. Christian Europe reacted with shock and expulsions of Jews, serving as an impetus to later Crusades.
In wide-ranging negotiations between the Fatimids and the Byzantine Empire in 1027–28, an agreement was reached whereby the new Caliph Ali az-Zahir (Al-Hakim's son) agreed to allow the rebuilding and redecoration of the church. The rebuilding was finally completed at a huge expense by Emperor Constantine IX Monomachos and Patriarch Nicephorus of Constantinople in 1048. As a concession, the mosque in Constantinople was reopened and the khutba sermons were to be pronounced in az-Zahir's name. Muslim sources say a by-product of the agreement was the renunciation of Islam by many Christians who had been forced to convert under Al-Hakim's persecutions. In addition, the Byzantines, while releasing 5,000 Muslim prisoners, made demands for the restoration of other churches destroyed by Al-Hakim and the reestablishment of a patriarch in Jerusalem. Contemporary sources credit the emperor with spending vast sums in an effort to restore the Church of the Holy Sepulchre after this agreement was made. Still, "a total replacement was far beyond available resources. The new construction was concentrated on the rotunda and its surrounding buildings: the great basilica remained in ruins."
The rebuilt church site consisted of "a court open to the sky, with five small chapels attached to it." The chapels were east of the court of resurrection, where the western wall of the great basilica had been. They commemorated scenes from the passion, such as the location of the prison of Christ and his flagellation, and presumably were so placed because of the difficulties of free movement among shrines in the city streets. The dedication of these chapels indicates the importance of the pilgrims' devotion to the suffering of Christ. They have been described as 'a sort of Via Dolorosa in miniature'... since little or no rebuilding took place on the site of the great basilica. Western pilgrims to Jerusalem during the eleventh century found much of the sacred site in ruins." Control of Jerusalem, and thereby the Church of the Holy Sepulchre, continued to change hands several times between the Fatimids and the Seljuk Turks (loyal to the Abbasid caliph in Baghdad) until the Crusaders' arrival in 1099.
Many historians maintain that the main concern of Pope Urban II, when calling for the First Crusade, was the threat to Constantinople from the Turkish invasion of Asia Minor in response to the appeal of Byzantine Emperor Alexios I Komnenos. Historians agree that the fate of Jerusalem and thereby the Church of the Holy Sepulchre was of concern to if not the immediate goal of papal policy in 1095. The idea of taking Jerusalem gained more focus as the Crusade was underway. The rebuilt church site was taken from the Fatimids (who had recently taken it from the Abassids) by the knights of the First Crusade on 15 July 1099.
The First Crusade was envisioned as an armed pilgrimage, and no crusader could consider his journey complete unless he had prayed as a pilgrim at the Holy Sepulchre. The classical theory is that Crusader prince Godfrey of Bouillon, who became the first Crusader monarch of Jerusalem, decided not to use the title "king" during his lifetime, and declared himself "Advocatus Sancti Sepulchri" ("Protector [or Defender] of the Holy Sepulchre"). By the Crusader period, a cistern under the former basilica was rumoured to have been where Helena had found the True Cross, and began to be venerated as such; the cistern later became the "Chapel of the Invention of the Cross", but there is no evidence of the site's identification before the 11th century, and modern archaeological investigation has now dated the cistern to 11th-century repairs by Monomachos.
According to the German clergyman and Orient pilgrim Ludolf von Sudheim, the keys of the Chapel of the Holy Sepulchre were in hands of the "ancient Georgians" and the food, alms, candles and oil for lamps were given to them by the pilgrims at the south door of the church.
William of Tyre, chronicler of the Crusader Kingdom of Jerusalem, reports on the renovation of the Church in the mid-12th century. The Crusaders investigated the eastern ruins on the site, occasionally excavating through the rubble, and while attempting to reach the cistern, they discovered part of the original ground level of Hadrian's temple enclosure; they transformed this space into a chapel dedicated to Helena, widening their original excavation tunnel into a proper staircase. The Crusaders began to refurnish the church in Romanesque style and added a bell tower. These renovations unified the small chapels on the site and were completed during the reign of Queen Melisende in 1149, placing all the holy places under one roof for the first time. The church became the seat of the first Latin Patriarchs and the site of the kingdom's scriptorium. It was lost to Saladin, along with the rest of the city, in 1187, although the treaty established after the Third Crusade allowed Christian pilgrims to visit the site. Emperor Frederick II (r. 1220–50) regained the city and the church by treaty in the 13th century while under a ban of excommunication, with the curious consequence that the holiest church in Christianity was laid under interdict. The church seems to have been largely in the hands of Greek Orthodox Patriarch Athanasius II of Jerusalem, c. 1231–47, during the Latin control of Jerusalem. Both city and church were captured by the Khwarezmians in 1244.
In 1545, the upper level of the church's bell tower collapsed.
The Franciscan friars renovated the church in 1555, as it had been neglected despite increased numbers of pilgrims. The Franciscans rebuilt the "Aedicule" ('small building'), extending the structure to create an antechamber. A marble shrine commissioned by Friar Boniface of Ragusa was placed to envelop the remains of Christ's tomb, probably to prevent pilgrims from touching the original rock or taking small pieces as souvenirs. A marble slab was placed over the limestone burial bed where Jesus's body is believed to have lain.
After the renovation of 1555, control of the church oscillated between the Franciscans and the Orthodox, depending on which community could obtain a favorable "firman" from the "Sublime Porte" at a particular time, often through outright bribery. Violent clashes were not uncommon. There was no agreement about this question, although it was discussed at the negotiations to the Treaty of Karlowitz in 1699. In 1767, weary of the squabbling, the "Porte" issued a firman that divided the church among the claimants.
A fire severely damaged the structure again in 1808, causing the dome of the Rotunda to collapse and smashing the Aedicule's exterior decoration. The Rotunda and the Aedicule's exterior were by architect Nikolaos Ch. Komnenos of Mytilene in the contemporary Ottoman Baroque style; the was also replaced. The interior of the antechamber, now known as the Chapel of the Angel, was partly rebuilt to a square ground plan in place of the previously semicircular western end.
Another decree in 1853 from the sultan solidified the existing territorial division among the communities and solidified the Status Quo for arrangements to "remain in their present state," causing differences of opinion about even minor changes. This is exemplified in the 'immovable ladder' under one of the windows; it has remained in the same position since at least 1757, aside from two occasions of temporary removal.
The dome was restored by Catholics, Greeks and Turks in 1868, being made of iron ever since.
By the time of the British Mandate, the cladding of red marble applied to the Aedicule by Komnenos had deteriorated badly and was detaching from the underlying structure; from 1947 until restoration work in 2017-17, it has been held in place with an exterior scaffolding of iron girders installed by the British authorities.
The dome was restored again in 1994–97 as part of extensive modern renovations that have been ongoing since 1959. During the 1970–78 restoration works and excavations inside the building, and under the nearby Muristan bazaar, it was found that the area was originally a quarry, from which white "meleke" limestone was struck.
East of the Chapel of Saint Helena, the excavators discovered a void containing a 2nd-century drawing of a Roman ship, two low walls supporting the platform of Hadrian's 2nd-century temple, and a higher 4th-century wall built to support Constantine's basilica. After the excavations of the early 1970s, the Armenian authorities converted this archaeological space into the Chapel of Saint Vartan, and created an artificial walkway over the quarry on the north of the chapel, so that the new chapel could be accessed (by permission) from the Chapel of Saint Helena.
After seven decades of being held together by steel girders, a careful restoration of the Aedicule was finally agreed upon and executed in 2016-17, funded by $4 million from King Abdullah II of Jordan and a $1.3 million from Mica Ertegun. For the first time since at least 1555, marble cladding that protected the supposed burial bed of Jesus from vandalism and souvenir takers was removed. When the cladding was first removed on 26 October, the National Technical University of Athens team found only a layer of fill material underneath. By the night of 28 October, the original limestone burial bed was revealed intact. This suggested that the tomb location has not changed through time and confirmed the existence of the original limestone cave walls within the Aedicule. The tomb was resealed shortly thereafter.
On March 25, 2020, Israeli health officials ordered the site closed to the public due to the COVID-19 pandemic. According to the keeper of the keys, it was the first such closure since 1349, during the Black Plague. Clerics continued regular prayers inside the building, and it reopened to visitors two months later on May 24.
The courtyard facing the entrance to the church is known as the parvis. Located around the parvis are a few smaller structures.
South of the parvis, opposite the church:
On the eastern side of the parvis, south to north:
North of the parvis, in front of the church façade or against it:
A group of three chapels borders the parvis on its west side. They originally formed the baptistery complex of the Constantinian church. The southernmost chapel was the vestibule, the middle chapel the baptistery, and the north chapel the chamber in which the patriarch chrismated the newly baptized before leading them into the rotunda north of this complex. Now they are dedicated as (from south to north)
The 12th-century Crusader bell tower is just south of the Rotunda, to the left of the entrance. Its upper level was lost in a 1545 collapse. In 1719, another two storeys were lost.
The wooden doors that compose the main entrance are the original, highly carved arched doors. Today, only the left-hand entrance is currently accessible, as the right doorway has long since been bricked up. The entrance to the church is in the south transept, through the crusader façade, in the parvis of a larger courtyard. This is found past a group of streets winding through the outer Via Dolorosa by way of a local souq in the Muristan. This narrow way of access to such a large structure has proven to be hazardous at times. For example, when a fire broke out in 1840, dozens of pilgrims were trampled to death.
Since the 7th century, the Muslim Nuseibeh family has been responsible for opening the door as an impartial party to the church's denominations. In 1187, Saladin took the church from the Crusaders and entrusted the Joudeh Al-Goudia family with its key, which is made of iron and long; the Nuseibehs remain its doorkeepers.
The 'immovable ladder' stands beneath a window on the façade.
Just inside the church entrance is a stairway leading up to Calvary (Golgotha), traditionally regarded as the site of Jesus' crucifixion and the most lavishly decorated part of the church. The exit is via another stairway opposite the first, leading down to the ambulatory. Golgotha and its chapels are just south of the main altar of the Catholicon.
Calvary is split into two chapels, one Greek Orthodox and one Catholic, each with its own altar. On the left (north) side, the Greek Orthodox chapel's altar is placed over the rock of Calvary (the 12th Station of the Cross), which can be touched through a hole in the floor beneath the altar. The rock can be seen under protective glass on both sides of the altar. The softer surrounding stone was removed when the church was built. The Roman Catholic (Franciscan) Chapel of the Nailing of the Cross (11th Station of the Cross) stretches to the south. Between the Catholic and the Orthodox altar, a statue of Mary with an 18th-century bust marks the 13th Station of the Cross.
On the ground floor, just underneath the Golgotha chapel, is the Chapel of Adam. According to tradition, Jesus was crucified over the place where Adam's skull was buried. According to some, the blood of Christ ran down the cross and through the rocks to fill Adam's skull. Through a window at the back of the 11th-century apse, the rock of Calvary can be seen with a crack traditionally held to be caused by the earthquake that followed Jesus' death; some scholars claim it is the result of quarrying against a natural flaw in the rock.
Behind the Chapel of Adam is the Museum of the Greek Orthodox Patriarchate, which holds many relics, including a 12th-century crystal mitre alleged to have once held a fragment of the Holy Cross.
Just inside the entrance to the church is the Stone of Anointing (also Stone of the Anointing or Stone of Unction), which tradition believes to be where Jesus' body was prepared for burial by Joseph of Arimathea, though this tradition is only attested since the crusader era (notably by the Italian Dominican pilgrim Riccoldo da Monte di Croce in 1288), and the present stone was only added in the 1810 reconstruction.
The wall behind the stone is defined by its striking blue balconies and tau cross-bearing red banners (depicting the insignia of the Brotherhood of the Holy Sepulchre), and is decorated with lamps. The modern three-part mosaic along the wall depicts the anointing of Jesus' body, preceded on the right by the Descent from the Cross, and succeeded on the left by the Burial of Jesus.
The wall was a temporary addition to support the arch above it, which had been weakened after the damage in the 1808 fire; it blocks the view of the rotunda, separates the entrance from the Catholicon, sits on top of the now empty and desecrated graves of four 12th-century crusader kings—including Godfrey of Bouillon and Baldwin I of Jerusalem—and is no longer structurally necessary. Opinions differ as to whether it is to be seen as the 13th Station of the Cross, which others identify as the lowering of Jesus from the cross and located between the 11th and 12th stations on Calvary.
The lamps that hang over the Stone of Unction, adorned with cross-bearing chain links, are contributed by Armenians, Copts, Greeks and Latins.
Immediately to the left of the entrance is a bench that has traditionally been used by the church's Muslim doorkeepers, along with some Christian clergy, as well as electrical wiring. To the right of the entrance is a wall along the ambulatory containing the staircase leading to Golgotha. Further along the same wall is the entrance to the Chapel of Adam.
The rotunda is the building of the larger dome located on the far west side. In the centre of the rotunda is a small chapel called the "Kouvouklion" in Greek or the "Aedicula" in Latin, which encloses the Holy Sepulchre. The Aedicule has two rooms, the first holding the Angel's Stone, which is believed to be a fragment of the large stone that sealed the tomb; the second is the tomb of Jesus. Possibly due to the fact that pilgrims laid their hands on the tomb or to prevent eager pilgrims from removing bits of the original rock as souvenirs, a marble plaque was placed in the fourteenth century on the tomb to prevent further damage to the tomb.
Under the Status Quo, the Eastern Orthodox, Roman Catholic, and Armenian Apostolic Churches all have rights to the interior of the tomb, and all three communities celebrate the Divine Liturgy or Holy Mass there daily. It is also used for other ceremonies on special occasions, such as the Holy Saturday ceremony of the Holy Fire led by the Greek Orthodox Patriarch (with the participation of the Coptic and Armenian patriarchs). To its rear, in a chapel constructed of iron latticework, lies the altar used by the Coptic Orthodox. Historically, the Georgians also retained the key to the Aedicule.
From May 2016 to March 2017, the Aedicule underwent restoration and repairs after the Israel Antiquities Authority declared the structure unsafe. Much of the $4 million project was funded by the World Monuments Fund. King Abdullah II of Jordan also contributed a substantial sum to make the restoration possible.
West of the Aedicule, to the rear of the Rotunda, is the Syriac Chapel with Tomb of Joseph of Arimathea, located in a Constantinian apse and containing an opening to an ancient Jewish rock-cut tomb. This chapel is where the Syriac Orthodox celebrate their Liturgy on Sundays.
To the right of the sepulchre on the northwestern edge of the Rotunda is the Chapel of the Apparition, which is reserved for Roman Catholic use.
In the central nave of the Crusader-era church, just east of the larger rotunda, is the Crusader structure housing the main altar of the Church, today the Greek Orthodox "catholicon". Its dome is in diameter, and sits directly over the centre of the transept crossing of the choir where the "compas" is situated, an omphalos ("navel") stone once thought to be the center of the world and still venerated as such by Orthodox Christians (associated with the site of the Crucifixion and the Resurrection).
Since 1996 this dome is topped by the monumental Golgotha Crucifix which the Greek Patriarch Diodoros I of Jerusalem consecrated. It was at the initiative of Israeli professor, Gustav Kühnel, to erect a new crucifix at the Church of the Holy Sepulchre in Jerusalem that would not only be worthy of the singularity of the site, but that would also become a symbol of the efforts of unity in the community of Christian faith.
East of this is a large iconostasis demarcating the Orthodox sanctuary before which is set the throne of the Greek Orthodox Patriarch of Jerusalem on the south side facing the throne of the Greek Orthodox Patriarch of Antioch on the north side.
South of the Aedicule is the "Place of the Three Marys", marked by a stone canopy and a large modern wall mosaic. From here one can enter the Armenian monastery which stretches over the ground and first upper floor of the church's southeastern part.
The Syriac Orthodox Chapel of Saint Joseph of Arimathea and Saint Nicodemus. On Sundays and feast days it is furnished for the celebration of Mass. It is accessed from the Rotunda, by a door west of the Aedicule.
On the far side of the chapel is the low entrance to an almost complete 1st-century Jewish tomb, initially holding six "kokh"-type funeral shafts radiating from a central chamber, two of which are still exposed. Although this space was discovered relatively recently and contains no identifying marks, some believe that Joseph of Arimathea and Nicodemus were buried here. Since Jews always buried their dead outside the city, the presence of this tomb proves that the Holy Sepulchre site was outside the city walls at the time of the crucifixion.
In the northeast side of the complex there is the Prison of Christ, alleged to be where Jesus was held. The Greek Orthodox are showing pilgrims yet another place where Jesus was allegedly held, the similarly named Prison of Christ in their Monastery of the Praetorium, located near the Church of Ecce Homo between the Second and Third Stations of the Via Dolorosa. The Armenians regard a recess in the Monastery of the Flagellation at the Second Station of the Via Dolorosa as the Prison of Christ. A cistern among the ruins beneath the Church of St. Peter in Gallicantu on Mount Zion is also alleged to have been the Prison of Christ. To reconcile the traditions, some allege that Jesus was held in the Mount Zion cell in connection with his trial by the Jewish High Priest, at the Praetorium in connection with his trial by the Roman governor Pilate, and near the Golgotha before crucifixion.
The chapels in the ambulatory are, from north to south: the Greek Chapel of Saint Longinus, the Armenian Chapel of Division of Robes, the entrance to the Chapel of Saint Helena, and the Greek Chapel of the Derision.
An Ottoman "status quo" decided upon in 1757 upholds the state of affairs for certain Holy Land sites, including the Church of the Holy Sepulchre.
The "status quo" was upheld in Sultan Abdülmecid I's "firman" (decree) of 1852/3, which pinned down the now-permanent statutes of property and the regulations concerning the roles of the different denominations and other custodians.
The primary custodians are the Greek Orthodox, Armenian Apostolic, and Roman Catholic Churches, with the Greek Orthodox Church having the lion's share. In the 19th century, the Coptic Orthodox, the Ethiopian Orthodox and the Syriac Orthodox acquired lesser responsibilities, which include shrines and other structures in and around the building. Greek Orthodox act through the Greek Orthodox Patriarchate as well as through the Brotherhood of the Holy Sepulchre. Roman Catholics act through the Franciscan Custody of the Holy Land.
None of these controls the main entrance. In 1192, Saladin assigned door-keeping responsibilities to the Muslim Nuseibeh family. The wooden doors that compose the main entrance are the original, highly carved doors. The Joudeh Al-Goudia family were entrusted as custodian to the keys of the Holy Sepulchre by Saladin in 1187. Despite occasional disagreements, religious services take place in the Church with regularity and coexistence is generally peaceful. An example of concord between the Church custodians is the full restoration of the Aedicule from 2016 to 2017.
The establishment of the modern Status Quo in 1853 did not halt controversy and occasional violence. On a hot summer day in 2002, a Coptic monk moved his chair from its agreed spot into the shade. This was interpreted as a hostile move by the Ethiopians and eleven were hospitalized after the resulting fracas. In another incident in 2004, during Orthodox celebrations of the Exaltation of the Holy Cross, a door to the Franciscan chapel was left open. This was taken as a sign of disrespect by the Orthodox and a fistfight broke out. Some people were arrested, but no one was seriously injured.
On Palm Sunday, in April 2008, a brawl broke out when a Greek monk was ejected from the building by a rival faction. Police were called to the scene but were also attacked by the enraged brawlers. On Sunday, 9 November 2008, a clash erupted between Armenian and Greek monks during celebrations for the Feast of the Cross.
In February 2018, the church was closed following a tax dispute over 152 million euros of uncollected taxes on church properties. The city hall stressed that the Church of the Holy Sepulchre and all other churches are exempt from the taxes, with the changes only affecting establishments like "hotels, halls and businesses" owned by the churches. NPR had reported that the Greek Orthodox Church calls itself the second-largest landowner in Israel, after the Israeli government.
There was a lock-in protest against an Israeli legislative proposal which would expropriate church lands that had been sold to private companies since 2010, a measure which church leaders assert constitutes a serious violation of their property rights and the Status Quo. In a joint official statement the church authorities protested what they considered to be the peak of a systematic campaign in:
a discriminatory and racist bill that targets solely the properties of the Christian community in the Holy Land ... This reminds us all of laws of a similar nature which were enacted against the Jews during dark periods in Europe.
The 2018 Taxation affair does not cover any church buildings or religious related facilities (because they are exempt by law), but commercial facilities such as the Notre Dame Hotel which was not paying the arnona tax, and any land which is owned and used as a commercial land. The church hold the rights to land where private homes have been constructed, and some of the disagreement had been raised after the Knesset had proposed a bill that will make it harder for a private company not to extend a lease for land used by homeowners. The church leaders have said that such a bill will make it harder for them to sell church-owned lands. According to "The Jerusalem Post":
The stated aim of the bill is to protect homeowners against the possibility that private companies will not extend their leases of land on which their houses or apartments stand.
In June 2019, a number of Christian denominations in Jerusalem raised their voice against the Supreme Court's decision to uphold the sale of three properties by the Greek Orthodox Patriarchate to Ateret Cohanim – an organization that seeks to increase Jews in Jerusalem. The church leaders warned that if the organization gets the access to control the sites, Christians will lose access to the Church of the Holy Sepulchre.
The site of the church had been a temple to Jupiter or Venus built by Hadrian before Constantine's edifice was built. Hadrian's temple had been located there because it was the junction of the main north-south road with one of the two main east-west roads and directly adjacent to the forum (now the location of the Muristan, which is smaller than the former forum). The forum itself had been placed, as is traditional in Roman towns, at the junction of the main north-south road with the other main east-west road (which is now El-Bazar/David Street). The temple and forum together took up the entire space between the two main east-west roads (a few above-ground remains of the east end of the temple precinct still survive in the Alexander Nevsky Church complex of the "Russian Mission in Exile").
From the archaeological excavations in the 1970s, it is clear that construction took over most of the site of the earlier temple enclosure and that the "Triportico" and "Rotunda" roughly overlapped with the temple building itself; the excavations indicate that the temple extended at least as far back as the Aedicule, and the temple enclosure would have reached back slightly further. Virgilio Canio Corbo, a Franciscan priest and archaeologist, who was present at the excavations, estimated from the archaeological evidence that the western retaining wall of the temple itself would have passed extremely close to the east side of the supposed tomb; if the wall had been any further west any tomb would have been crushed under the weight of the wall (which would be immediately above it) if it had not already been destroyed when foundations for the wall were made.
Other archaeologists have criticized Corbo's reconstructions. Dan Bahat, the former city archaeologist of Jerusalem, regards them as unsatisfactory, as there is no known temple of Aphrodite (Venus) matching Corbo's design, and no archaeological evidence for Corbo's suggestion that the temple building was on a platform raised high enough to avoid including anything sited where the Aedicule is now; indeed Bahat notes that many temples to Aphrodite have a rotunda-like design, and argues that there is no archaeological reason to assume that the present rotunda was not based on a rotunda in the temple previously on the site.
The New Testament describes Jesus's tomb as being outside the city wall, as was normal for burials across the ancient world, which were regarded as unclean. Today, the site of the Church is within the current walls of the old city of Jerusalem. It has been well documented by archaeologists that in the time of Jesus, the walled city was smaller and the wall then was to the east of the current site of the Church. In other words, the city had been much narrower in Jesus' time, with the site then having been outside the walls; since Herod Agrippa (41–44) is recorded by history as extending the city to the north (beyond the present northern walls), the required repositioning of the western wall is traditionally attributed to him as well.
The area immediately to the south and east of the sepulchre was a quarry and outside the city during the early first century as excavations under the Lutheran Church of the Redeemer across the street demonstrated.
The church is a part of the UNESCO World Heritage Site Old City of Jerusalem.
The Christian Quarter and the (also Christian) Armenian Quarter of the Old City of Jerusalem are both located in the northwestern and western part of the Old City, due to the fact that the Holy Sepulchre is located close to the northwestern corner of the walled city. The adjacent neighbourhood within the Christian Quarter is called the Muristan, a term derived from the Persian word for hospital—Christian pilgrim hospices have been maintained in this area near the Holy Sepulchre since at least the time of Charlemagne.
From the ninth century onward, the construction of churches inspired by the Anastasis was extended across Europe. One example is Santo Stefano in Bologna, Italy, an agglomeration of seven churches recreating shrines of Jerusalem.
Several churches and monasteries in Europe, for instance, in Germany and Russia, and at least one church in the United States have been modeled on the Church of the Resurrection, some even reproducing other holy places for the benefit of pilgrims who could not travel to the Holy Land. They include the ("Holy Tomb") of Görlitz, constructed between 1481 and 1504, the New Jerusalem Monastery in Moscow Oblast, constructed by Patriarch Nikon between 1656 and 1666, and Mount St. Sepulchre Franciscan Monastery built by the Franciscans in Washington, DC in 1898.
Footnotes
Citations
Custodians
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Cernunnos
Cernunnos is the conventional name given in Celtic studies to depictions of the "horned god" of Celtic polytheism. Over 50 examples of his imagery have been found from the Gallo-Roman period, mostly in north-eastern Gaul as well as among the Celtiberians. Cernunnos is depicted with antlers, seated cross-legged, and is associated with stags, horned serpents, dogs, bulls, and rats. He is usually holding or wearing a torc.
Due to the lack of surviving literature, details about his name, his followers, or his significance in Celtic religion are unknown. Interpretations of his role vary from seeing him as a god of animals, nature and fertility to a god of travel, commerce and bi-directionality.
The name "[C]ernunnos" only appears on the Pillar of the Boatmen ("Pilier des nautes"), a Gallo-Roman monument dating to the early 1st century CE. The Proto-Celtic form of the theonym is reconstructed as either *"Cerno-on-os" or *"Carno-on-os". The augmentative "-on-" is characteristic of theonyms, as in Maponos, Epona, Matronae, and Sirona.
Maier (2010) states that the etymology of "Cernunnos" is unclear, but seems to be rooted in the Celtic word for "horn" or "antler" (as in "Carnonos").
The Gaulish word "karnon" "horn" is cognate with Latin "cornu" and Germanic "*hurnaz", English "horn", ultimately from Proto-Indo-European "".
The etymon "karn-" "horn" appears in both Gaulish and Galatian branches of Continental Celtic. Hesychius of Alexandria glosses the Galatian word "karnon" (κάρνον) as "Gallic trumpet", that is, the Celtic military horn listed as the carnyx (κάρνυξ) by Eustathius of Thessalonica, who notes the instrument's animal-shaped bell. The root also appears in the names of Celtic polities, most prominent among them the Carnutes, meaning something like "the Horned Ones," and in several personal names found in inscriptions.
The name has also been compared to a divine epithet "Carnonos" in a Celtic inscription written in Greek characters at Montagnac, Hérault (as καρνονου, "karnonou", in the dative case).
A Gallo-Latin adjective "carnuātus", "horned," is also found.
The Pillar of the Boatmen ("Pilier des nautes") monument was probably constructed by Gaulish sailors in 14 CE. It was discovered in 1710 within the foundations of the cathedral of Notre-Dame de Paris, site of ancient Lutetia, the "civitas" capital of the Celtic Parisii. It is now displayed in the Musée National du Moyen Age in Paris.
The distinctive stone pillar is an important monument of Gallo-Roman religion. Its low reliefs depict and label by name several Roman deities such as Jupiter, Vulcan, and Castor and Pollux, along with Gallic deities such as Esus, Smertrios, and Tarvos Trigaranus. The name "Cernunnos" can be read clearly on 18th century drawings of the inscriptions, but the initial letter has been obscured since, so that today only a reading "[_]ernunnos" can be verified.
Additional evidence is given by one inscription on a metal plaque from Steinsel-Rëlent in Luxembourg, in the territory of the Celtic Treveri. This inscription read "Deo Ceruninco", "to the God Cerunincos", assumed to be the same deity. The Gaulish inscription from Montagnac reads αλλετ[ει]νος καρνονου αλ[ι]σο[ντ]εας ("Alletinos [dedicated this] to Carnonos of Alisontea"), with the last word possibly a place name based on "Alisia", "service-tree" or "rock" (compare Alesia, Gaulish "Alisiia").
The god labelled "[C]ernunnos" on the Pillar of the Boatmen is depicted with stag's antlers, both having torcs hanging from them. The lower part of the relief is lost, but the dimensions suggest that the god was sitting cross-legged, providing a direct parallel to the antlered figure on the Gundestrup cauldron.
In spite of the name "Cernunnos" being attested nowhere else, it is commonly used in Celtological literature as describing all comparable depictions of horned/antlered deities.
This "Cernunnos" type in Celtic iconography is often portrayed with a stag and the ram-horned serpent. Less frequently, there are bulls (at Rheims), dogs and rats. Because of the image of him on the Gundestrup Cauldron, some scholars describe Cernunnos as the "Lord of the Animals" or the "Lord of Wild Things", and Miranda Green describes him as a "peaceful god of nature and fruitfulness" who seems to be seated in a manner that suggests traditional shamans who were often depicted surrounded by animals. Other academics such as Ceisiwr Serith describes Cernunnos as a god of bi-directionality and mediator between opposites, seeing the animal symbolism in the artwork reflecting this idea.
The "Pilier des nautes" links him with sailors and with commerce, suggesting that he was also associated with material wealth as does the coin pouch from the Cernunnos of Rheims (Marne, Champagne, France)—in antiquity, Durocortorum, the "civitas" capital of the Remi tribe—and the stag vomiting coins from Niedercorn-Turbelslach (Luxembourg) in the lands of the Treveri. The god may have symbolized the fecundity of the stag-inhabited forest.
Other examples of "Cernunnos" images include a petroglyph in Val Camonica in Cisalpine Gaul. The antlered human figure has been dated as early as the 7th century BCE or as late as the 4th. An antlered child appears on a relief from Vendeuvres, flanked by serpents and holding a purse and a torc. The best known image appears on the Gundestrup cauldron found on Jutland, dating to the 1st century BCE, thought to depict Celtic subject matter though usually regarded as of Thracian workmanship.
Among the Celtiberians, horned or antlered figures of the Cernunnos type include a "Janus-like" god from Candelario (Salamanca) with two faces and two small horns; a horned god from the hills of Ríotinto (Huelva); and a possible representation of the deity Vestius Aloniecus near his altars in Lourizán (Pontevedra). The horns are taken to represent "aggressive power, genetic vigor and fecundity."
Divine representations of the Cernunnos type are exceptions to the often-expressed view that the Celts only began to picture their gods in human form after the Roman conquest of Gaul.
The Celtic "horned god", while well attested in iconography, cannot be identified in description of Celtic religion in Roman ethnography and does not appear to have been given any "interpretatio romana", perhaps due to being too distinctive to be translatable into the Roman pantheon.
While Cernunnos was never assimilated, scholars have sometimes compared him functionally to Greek and Roman divine figures such as Mercury, Actaeon, specialized forms of Jupiter, and Dis Pater, the latter of whom Julius Caesar said was considered the ancestor of the Gauls.
There have been attempts to find the "cern" root in the name of Conall Cernach, the foster brother of the Irish hero Cuchulainn in the Ulster Cycle. In this line of interpretation, "Cernach" is taken as an epithet with a wide semantic field—"angular; victorious; bearing a prominent growth"—and Conall is seen as "the same figure" as the ancient Cernunnos.
There is even greater evidence available to connect Conall Cernach to Cernunnos than the similarity in the names. A brief passage involving Conall in an eighth-century story entitled "Táin Bó Fraích" ("The Cattle Raid on Fraech") has been questioned before for its anti-climactic conclusion to an epic Celtic tale. In this passage Conall Cernach is portrayed as a hero and mighty warrior who assists the protagonist Fraech in rescuing his wife and son, and in reclaiming for Fraech his cattle. The fort that Conall must penetrate is guarded by a mighty serpent. The supposed anti-climax of this tale is when the fearsome serpent, instead of attacking Conall, darts to Conall's waist and girdles him as a belt. Rather than killing the serpent, Conall allows it to live, and then proceeds to attack and rob the fort of its great treasures the serpent previously protected.
Cernunnos, as the conjectured Gaulish manifestation of the Roman Dis Pater, is considered to share the latter's attributes of ruling over the hidden treasures of the underworld. Subterranean treasures were commonly linked in Medieval Bestiaries to the serpent, the occupant of the underground, or otherworld, and the keeper of its treasures and mysteries. This aspect of Cernunnos is depicted on a stone statue from a well in Sommerécourt, Haute-Marne, France, and on a bronze figurine from Autun. Both statue and figurine portray Cernunnos with the two ram-headed serpents encircling his waist. This is more than just a small similarity to the instance of the serpent that guarded the treasure of the fort in "Táin Bó Fraích" surrendering to Conall Cernach and becoming his belt. Cernunnos' connections to the deity Mars serve to underline Conall's role as hero-warrior in the tale.
The anti-climactic nature of the eighth-century Irish tale then gains significant clarity in the light of the relationship between a horned or antler-bearing deity, warrior, or progenitor, and the chthonic dwelling, treasure-guarding serpent that encircled the waist of the one it chose to protect. This universal Celtic concept comes down to us as a mere echo of its ancient self through centuries of the Christianization of Ireland. The Gaelic Cernunnos may now possibly only be found in the slight similarity of a name and the peculiarity of a single passage from a Middle Ages Irish epic.
Some see the qualities of Cernunnos subsumed into the "life" of Saint Ciarán of Saighir, one of the Twelve Apostles of Ireland. When he was building his first tiny cell, as his hagiograph goes, his first disciple and monk was a boar that had been rendered gentle by God. This was followed by a fox, a badger, a wolf and a stag.
In Wicca and other forms of Neopaganism a Horned God is revered; this divinity syncretises a number of horned or antlered gods from various cultures, including Cernunnos. The Horned God reflects the seasons of the year in an annual cycle of life, death and rebirth.
In the tradition of Gardnerian Wicca, the Horned God is sometimes specifically referred to as Cernunnos, or sometimes also as Kernunno. | https://en.wikipedia.org/wiki?curid=7811 |
Click consonant
Click consonants, or clicks, are speech sounds that occur as consonants in many languages of Southern Africa and in three languages of East Africa. Examples familiar to English-speakers are the "Tut-tut" (British spelling) or "Tsk! Tsk!" (American spelling) used to express disapproval or pity, the "tchick!" used to spur on a horse, and the "clip-clop!" sound children make with their tongue to imitate a horse trotting.
Technically, clicks are obstruents articulated with two closures (points of contact) in the mouth, one forward and one at the back. The enclosed pocket of air is rarefied by a sucking action of the tongue (in technical terminology, clicks have a lingual ingressive airstream mechanism). The forward closure is then released, producing what may be the loudest consonants in the language, but in some languages such as Hadza and Sandawe, clicks can be more subtle and may even be mistaken for ejectives.
Click consonants occur at six principal places of articulation. The International Phonetic Alphabet (IPA) may represent a click by placing the assigned symbol for five of the places of articulation (there is as yet no dedicated symbol for the sixth) adjacent to a symbol for a non-click sound at the rear place of articulation, or the click symbol may be combined with diacritics for voicing, nasalization, etc. The IPA symbols are used in writing most Khoisan languages, but Bantu languages such as Zulu typically use Latin , and for dental, lateral and alveolar clicks respectively.
The above clicks sound like affricates, in that they involve a lot of friction. The other two families are more abrupt sounds that do not have this friction.
Clicks occur in all three Khoisan language families of southern Africa, where they may be the most numerous consonants. To a lesser extent they occur in three neighbouring groups of Bantu languages—which borrowed them, directly or indirectly, from Khoisan. In the southeast, in eastern South Africa, Swaziland, Lesotho, Zimbabwe and southern Mozambique, they were adopted from a Tuu language or languages by the languages of the Nguni cluster (especially Zulu, Xhosa and Phuthi, but also to a lesser extent Swazi and Ndebele), and spread from them in a reduced fashion to the Zulu-based pidgin Fanagalo, Sesotho, Tsonga, Ronga, the Mzimba dialect of Tumbuka and more recently to Ndau and urban varieties of Pedi, where the spread of clicks continues. The second point of transfer was near the Caprivi Strip and the Okavango River where, apparently, the Yeyi language borrowed the clicks from a West Kalahari Khoe language; a separate development led to a smaller click inventory in the neighbouring Mbukushu, Kwangali, Gciriku, Kuhane and Fwe languages in Angola, Namibia, Botswana and Zambia. These sounds occur not only in borrowed vocabulary, but have spread to native Bantu words as well, in the case of Nguni at least partially due to a type of word taboo called hlonipha. Some creolised varieties of Afrikaans, such as Oorlams, retain clicks in Khoekhoe words.
Three languages in East Africa use clicks: Sandawe and Hadza of Tanzania, and Dahalo, an endangered South Cushitic language of Kenya that has clicks in only a few dozen words. It is thought the latter may remain from an episode of language shift.
The only non-African language known to have clicks as regular speech sounds is Damin, a ritual code once used by speakers of Lardil in Australia. One of the clicks in Damin is actually an egressive click, using the tongue to compress the air in the mouth for an outward (egressive) "spurt".
Once clicks are borrowed into a language as regular speech sounds, they may spread to native words, as has happened due to "hlonipa" word-taboo in the Nguni languages. In Gciriku, for example, the European loanword "tomate" (tomato) appears as "cumáte" with a click "c", though it begins with a "t" in all neighbouring languages.
Scattered clicks are found in ideophones and mimesis in other languages, such as Kongo , Mijikenda and Hadza (Hadza does not otherwise have labial clicks). Ideophones often use phonemic distinctions not found in normal vocabulary.
English and many other languages may use bare clicks in interjections, without the accompaniment of vowels, such as the dental "tsk-tsk" sound used to express disapproval, or the lateral "tchick" used with horses. In Armenian, Bulgarian, Greek, Levantine Arabic, Maltese, Persian, Romanian, Turkish, occasionally in French, as well as southern Italian languages such as Sicilian, in which a bare dental click accompanied by tipping the head upwards signifies "no". Libyan Arabic apparently has three such sounds.
Clicks occasionally turn up elsewhere, as in the special registers twins sometimes develop with each other. In West Africa, clicks have been reported allophonically, and similarly in French and German, faint clicks have been recorded in rapid speech where consonants such as and overlap between words. In Rwanda, the sequence may be pronounced either with an epenthetic vowel, , or with a light bilabial click, —often by the same speaker.
Speakers of Gan Chinese from Ningdu county, as well as speakers of Mandarin from Beijing and Jilin and presumably people from other parts of the country, produce flapped nasal clicks in nursery rhymes with varying degrees of competence, in the words for 'goose' and 'duck', both of which begin with in Gan and until recently began with in Mandarin as well. In Gan, the nursery rhyme is,
where the onsets are all pronounced .
Occasionally other languages are claimed to have click sounds in general vocabulary. This is usually a misnomer for ejective consonants, which are found across much of the world.
For the most part, the Southern African Khoisan languages only use root-initial clicks. Hadza, Sandawe and several Bantu languages also allow syllable-initial clicks within roots. In no language does a click close a syllable or end a word, but then the languages that happen to have clicks have mostly CV syllables and allow at most only a limited set of consonants (such as a nasal or a glottal stop) to close a syllable or end a word, most consonants share the distribution of clicks in these languages.
The Khoesan families (Tuu, Kxʼa and Khoe) all have at least four click types, } or variants thereof. A few have five, with bilabial } or retroflex }. Hadza and Sandawe have three, }. Yeyi is the only Bantu language with four, }, while Xhosa and Zulu have three, }, and most Bantu languages with clicks have fewer than that.
Like other consonants, clicks can be described using four parameters: place of articulation, manner of articulation, phonation (including glottalisation) and airstream mechanism. As noted above, clicks necessarily involve at least two closures, which in some cases operate partially independently: an anterior articulation traditionally represented by the special click symbol in the IPA—and a posterior articulation traditionally described as oral or nasal, voiced or voiceless, etc. The literature also describes a contrast between velar and uvular rear articulations for some languages.
However, recent work shows that in languages that make this distinction, all clicks have a uvular, or even pharyngeal, rear closure—and the clicks explicitly described as uvular are in fact clusters/contours of a click plus a pulmonic or ejective component, in which the cluster/contour has two release bursts, the forward (click) and then the rearward (uvular) component. "Velar" clicks in these languages have only a single release burst, that of the forward click release, and the release of the rear articulation isn't separately audible (Miller 2011).
Nonetheless, in most of the literature the stated place of the click is the anterior articulation (called the "release" or "influx)," whereas the manner is ascribed to the posterior articulation (called the "accompaniment" or "efflux)." The anterior articulation defines the "click type" and is written with the IPA letter for the click (dental , alveolar , etc.), whereas the traditional term 'accompaniment' conflates the categories of manner (nasal, affricated), phonation (voiced, aspirated, breathy voiced, glottalised), as well as any change in the airstream with the release of the posterior articulation (pulmonic, ejective), all of which are transcribed with additional letters or diacritics, as in the "nasal alveolar click", or or—to take an extreme example—the "voiced (uvular) ejective alveolar click", .
The size of click inventories ranges from as few as three (in Sesotho) or four (in Dahalo), to dozens in the Kxʼa and Tuu (Northern and Southern Khoisan) languages. Taa, the last vibrant language in the latter family, has 45 to 115 click phonemes, depending on analysis (clusters vs. contours), and over 70% of words in the dictionary of this language begin with a click.
Clicks appear more stop-like (sharp/abrupt) or affricate-like (noisy) depending on their place of articulation: In southern Africa, clicks involving an apical alveolar or laminal postalveolar closure are acoustically abrupt and sharp, like stops, whereas labial, dental and lateral clicks typically have longer and acoustically noisier click types that are superficially more like affricates. In East Africa, however, the alveolar clicks tend to be flapped, whereas the lateral clicks tend to be more sharp.
The five click places of articulation with dedicated symbols in the International Phonetic Alphabet (IPA) are labial , dental , palatal ("palato-alveolar") , (post)alveolar ("retroflex") and lateral . In most languages, the alveolar and palatal types are abrupt; that is, they are sharp popping sounds with little frication (turbulent airflow). The labial, dental and lateral types, on the other hand, are typically noisy: they are longer, lip- or tooth-sucking sounds with turbulent airflow, and are sometimes called affricates. (This applies to the forward articulation; both may also have either an affricate or non-affricate rear articulation as well.) The apical places, and , are sometimes called "grave", because their pitch is dominated by low frequencies; whereas the laminal places, and , are sometimes called "acute", because they are dominated by high frequencies. (At least in the Nǁng language and Juǀʼhoan, this is associated with a difference in the placement of the rear articulation: "grave" clicks are uvular, whereas "acute" clicks are pharyngeal.) Thus the alveolar click sounds something like a cork pulled from a bottle (a low-pitch pop), at least in Xhosa; whereas the dental click is like English "tsk! tsk!," a high-pitched sucking on the incisors. The lateral clicks are pronounced by sucking on the molars of one or both sides. The labial click is different from what many people associate with a kiss: the lips are pressed more-or-less flat together, as they are for a or an , not rounded as they are for a .
The most populous languages with clicks, Zulu and Xhosa, use the letters "c, q, x," by themselves and in digraphs, to write click consonants. Most Khoisan languages, on the other hand (with the notable exceptions of Naro and Sandawe), use a more iconic system based on the pipe . (The exclamation point for the "retroflex" click was originally a pipe with a subscript dot, along the lines of "ṭ, ḍ, ṇ" used to transcribe the retroflex consonants of India.) There are also two main conventions for the second letter of the digraph as well: voicing may be written with "g" and uvular affrication with "x", or voicing with "d" and affrication with "g" (a convention of Afrikaans). In two orthographies of Juǀʼhoan, for example, voiced is written "g!" or "dq", and "!x" or "qg". In languages without , such as Zulu, may be written "gq".
There are a few less-well-attested articulations. A reported subapical retroflex articulation in Grootfontein !Kung turns out to be alveolar with lateral release, ; Ekoka !Kung has a fricated alveolar click with an s-like release, provisionally transcribed ; and Sandawe has a "slapped" alveolar click, provisionally transcribed (in turn, the lateral clicks in Sandawe are more abrupt and less noisy than in southern Africa). However, the Khoisan languages are poorly attested, and it is quite possible that, as they become better described, more click articulations will be found.
Formerly when a click consonant was transcribed, two symbols were used, one for each articulation, and connected with a tie bar. This is because a click such as was analysed as a nasal velar rear articulation pronounced simultaneously with the forward ingressive release . The symbols may be written in either order, depending on the analysis: or . However, a tie bar was not often used in practice, and when the manner is tenuis (a simple ), it was often omitted as well. That is, = = = = . Regardless, elements that do not overlap with the forward release are usually written according to their temporal order: Prenasalisation is always written first ( = = ), and the non-lingual part of a contour is always written second ( = = ).
However, it has become standard to analyse clicks as simplex segments, despite the fact that the front and rear articulations are independent, and to use diacritics to indicate the rear articulation and the accompaniment. At first this tended to be for , based on the belief that the rear articulation was velar; but as it has become clear that the rear articulation is often uvular or even pharyngeal even when there is no velar–uvular contrast, voicing and nasalisation diacritics more in keeping with the IPA have started to appear: for .
In practical orthography, the voicing or nasalisation is sometimes given the anterior place of articulation: "dc" for and "mʘ" for , for example.
In the literature on Damin, the clicks are transcribed as .
Places of articulation are often called click "types, releases," or "influxes," though 'release' is also used for the accompaniment/efflux. There are seven or eight known places of articulation, not counting slapped or egressive clicks. These are "(bi)labial affricated" , or "bilabial"; "laminal denti-alveolar affricated" , or "dental"; "apical (post)alveolar plosive" , or "alveolar"; "laminal palatal plosive" , or "palatal"; "laminal palatal affricated" (known only from Ekoka !Kung); "subapical postalveolar" , or "retroflex" (only known from Central !Kung and possibly Damin); and "apical (post)alveolar lateral" , or "lateral".
Languages illustrating each of these articulations are listed below. Given the poor state of documentation of Khoisan languages, it is quite possible that additional places of articulation will turn up. No language is known to contrast more than five.
Extra-linguistically, Coatlán Zapotec of Mexico uses a linguolabial click, , as mimesis for a pig drinking water, and several languages, such as Wolof, use a velar click , long judged to be physically impossible, for backchanneling and to express approval. A sublingual click ("sucking-teeth") is found across West Africa, the Caribbean and into the United States.
The exact place of the alveolar clicks varies between languages. The lateral, for example, is alveolar in Khoekhoe but postalveolar or even palatal in Sandawe; the central is alveolar in Nǀuu but postalveolar in Juǀʼhoan.
The terms for the click types were originally developed by Bleek in 1862. Since then there has been some conflicting variation. However, apart from "cerebral" (retroflex), which was found to be an inaccurate label when true retroflex clicks were discovered, Bleek's terms are still considered normative today. Here are the terms used in some of the main references.
The dental, lateral and bilabial clicks are rarely confused. However, the palatal and alveolar clicks frequently had conflicting names in older literature, and still do in Unicode. However, since Ladefoged & Traill (1984) clarified the places of articulation, the terms listed under Vosser (2013) have become standard, apart from details such as whether and are alveolar and postalveolar, or is bilabial or labiodental, in a particular language, or whether the rear articulation is velar, uvular or pharyngeal, which again varies between languages (or may even be contrastive within a language).
In several languages, including Nama and Juǀʼhoan, the alveolar click types and only occur, or preferentially occur, before back vowels, whereas the dental and palatal clicks occur before any vowel. The effect is most noticeable with the high front vowel . In Nama, for example, the diphthong is common but is rare after alveolar clicks, whereas the opposite is true after dental and palatal clicks. This is a common effect of uvular or uvularised consonants on vowels in both click and non-click languages. In Taa, for example, the back-vowel constraint is triggered by both alveolar clicks and uvular stops, but not by palatal clicks or velar stops: sequences such as and are rare to non-existent, whereas sequences such as and are common. It is also triggered by labial clicks, though not by labial stops. Clicks subject to this constraint involve a sharp retraction of the tongue during release.
Miller and colleagues (2003) used ultrasound imaging to show that the rear articulation of the alveolar clicks () in Nama is substantially different from that of palatal and dental clicks. Specifically, the shape of the body of the tongue in palatal clicks is very similar to that of the vowel , and involves the same tongue muscles, so that sequences such as involved a simple and quick transition. The rear articulation of the alveolar clicks, however, is several centimetres further back, and involves a different set of muscles in the uvular region. The part of the tongue required to approach the palate for the vowel is deeply retracted in , as it lies at the bottom of the air pocket used to create the vacuum required for click airstream. This makes the transition required for much more complex and the timing more difficult than the shallower and more forward tongue position of the palatal clicks. Consequently, takes 50 ms longer to pronounce than , the same amount of time required to pronounce .
Languages do not all behave alike. In Nǀuu, the simple clicks trigger the and allophones of and , whereas do not. All of the affricated contour clicks, such as , do as well, as do the uvular stops . However, the occlusive contour clicks pattern like the simple clicks, and does not trigger the back-vowel constraint. This is because they involve tongue-root raising rather than tongue-root retraction in the uvular-pharyngeal region. However, in Gǀwi, which is otherwise largely similar, both and trigger the back-vowel constraint (Miller 2009).
Click manners are often called click "accompaniments" or "effluxes", but both terms have met with objections on theoretical grounds.
There is a great variety of click manners, both simplex and complex, the latter variously analysed as consonant clusters or contours. With so few click languages, and so little study of them, it is also unclear to what extent clicks in different languages are equivalent. For example, the of Khoekhoe, of Sandawe and of Hadza may be essentially the same phone; no language distinguishes them, and the differences in transcription may have more to do with the approach of the linguist than with actual differences in the sounds. Such suspected allophones/allographs are listed on a common row in the table below.
Some Khoisan languages are typologically unusual in allowing mixed voicing in non-click consonant clusters/contours, such as , so it is not surprising that they would allow mixed voicing in clicks as well. This may be an effect of epiglottalised voiced consonants, because voicing is incompatible with epiglottalisation.
As do other consonants, clicks vary in phonation. Oral clicks are attested with four phonations: tenuis, aspirated, voiced and breathy voiced (murmured). Nasal clicks may also vary, with plain voiced, breathy voiced / murmured nasal, aspirated and unaspirated voiceless clicks attested (the last only in Taa). The aspirated nasal clicks are often said to have 'delayed aspiration'; there is nasal airflow throughout the click, which may become voiced between vowels, though the aspiration itself is voiceless. A few languages also have pre-glottalised nasal clicks, which have very brief prenasalisation but have not been phonetically analysed to the extent that other types of clicks have.
All languages have nasal clicks, and all but Dahalo and Damin also have oral clicks. All languages but Damin have at least one phonation contrast as well.
Clicks may be pronounced with a third place of articulation, glottal. A glottal stop is made during the hold of the click; the (necessarily voiceless) click is released, and then the glottal hold is released into the vowel. Glottalised clicks are very common, and they are generally nasalised as well. The nasalisation cannot be heard during the click release, as there is no pulmonic airflow, and generally not at all when the click occurs at the beginning of an utterance, but it has the effect of nasalising preceding vowels, to the extent that the glottalised clicks of Sandawe and Hadza are often described as prenasalised when in medial position. Two languages, Gǀwi and Yeyi, contrast plain and nasal glottalised clicks, but in languages without such a contrast, the glottalised click is nasal. Miller (2011) analyses the glottalisation as phonation, and so considers these to be simple clicks.
Various languages also have prenasalised clicks, which may be analysed as consonant sequences. Sotho, for example, allows a syllabic nasal before its three clicks, as in "nnqane" 'the other side' (prenasalised nasal) and "seqhenqha" 'hunk'.
There is ongoing discussion as to how the distinction between what were historically described as 'velar' and 'uvular' clicks is best described. The 'uvular' clicks are only found in some languages, and have an extended pronunciation that suggests that they are more complex than the simple ('velar') clicks, which are found in all. Nakagawa (1996) describes the extended clicks in Gǀwi as consonant clusters, sequences equivalent to English "st" or "pl", whereas Miller (2011) analyses similar sounds in several languages as click–non-click contours, where a click transitions into a pulmonic or ejective articulation within a single segment, analogous to how English "ch" and "j" transition from occlusive to fricative but still behave as unitary sounds. With ejective clicks, for example, Miller finds that although the ejective release follows the click release, it is the rear closure of the click that is ejective, not an independently articulated consonant. That is, in a simple click, the release of the rear articulation is not audible, whereas in a contour click, the rear (uvular) articulation is audibly released after the front (click) articulation, resulting in a double release.
These contour clicks may be "linguo-pulmonic", that is, they may transition from a click (lingual) articulation to a normal pulmonic consonant like (e.g. ); or "linguo-glottalic" and transition from lingual to an ejective consonant like (e.g. ): that is, a sequence of ingressive (lingual) release + egressive (pulmonic or glottalic) release. In some cases there is a shift in place of articulation as well, and instead of a uvular release, the uvular click transitions to a velar or epigottal release (depending on the description, or ). Although homorganic does not contrast with heterorganic in any known language, they are phonetically quite distinct (Miller 2011).
Apart from Dahalo, Damin and many of the Bantu languages (Yeyi and Xhosa being exceptions), 'click' languages have glottalised clicks. Contour clicks are restricted to southern Africa, but are very common there: they are found in all members of the Tuu, Kxʼa and Khoe families, as well as in the Bantu language Yeyi.
In a comparative study of clicks across various languages, using her own field work as well as phonetic descriptions and data by other field researchers, Miller (2011) posits 21 types of clicks that contrast in manner or airstream. The homorganic and heterorganic affricated ejective clicks do not contrast in any known language, but are judged dissimilar enough to keep separate. Miller's conclusions differ from those of the primary researcher of a language; see the individual languages for details.
(all spoken primarily in South Africa, Namibia and Botswana; Khoekhoe is like Korana except it has lost ejective )
(Zulu is like Xhosa apart from not having )
Each language below is illustrated with Ʞ as a placeholder for the different click types. Under each language are the orthography (in italics, with old forms in parentheses), the researchers' transcription (in ), or allophonic variation (in [brackets]). Some languages also have labialised or prenasalised clicks as well as those listed below.
Yeyi also has prenasalised . The original researchers believe that and are allophones.
A DoBeS (2008) study of the Western ǃXoo dialect of Taa found several new manners: creaky voiced (the voiced equivalent of glottalised oral), breathy-voiced nasal, prenasalised glottalised (the voiced equivalent of glottalised) and a (pre)voiced ejective. These extra voiced clicks reflect Western ǃXoo morphology, where many nouns form their plural by voicing their initial consonant. DoBeS analyses most Taa clicks as clusters, leaving nine basic manners (marked with asterisks in the table). This comes close to Miller's distinction between simple and contour clicks, shaded light and medium grey in the table.
Languages of the southern African Khoisan families only permit clicks at the beginning of a word root. However, they also restrict other classes of consonant, such as ejectives and affricates, to root-initial position. The Bantu languages, Hadza and Sandawe allow clicks within roots.
In some languages, all click consonants within known roots are the same phoneme, as in Hadza "cikiringcingca" 'pinkie finger', which has three tenuis dental clicks. Other languages are known to have the occasional root with different clicks, as in Xhosa "ugqwanxa" 'black ironwood', which has a slack-voiced alveolar click and a nasal lateral click.
Like other articulatorily complex consonants, clicks tend to be found in lexical words rather than in grammatical words, but this is only a tendency. In Nǁng, for example, there are two sets of personal pronouns, a full one without clicks and a partial set with clicks ("ńg" 'I', "á" 'thou', "í" 'we all', "ú" 'you', vs. "nǀǹg" 'I', "gǀà" 'thou', "gǀì" 'we all', "gǀù" 'you'), as well as other grammatical words with clicks such as "ǁu" 'not' and "nǀa" 'with, and'.
One genetic study concluded that clicks, which occur in the languages of the genetically divergent populations Hadza and !Kung, may be an ancient element of human language. However, this conclusion relies on several dubious assumptions (see Hadza language), and most linguists assume that clicks, being quite complex consonants, arose relatively late in human history. How they arose is not known, but it is generally assumed that they developed from sequences of non-click consonants, as they are found allophonically for doubly articulated consonants in West Africa, where sequences overlap at word boundaries in German, and for the sequence in Ndau and Tonga. Such developments have also been posited in historical reconstruction. For example, the Sandawe word for 'horn', , with a lateral affricate, may be a cognate with the root found throughout the Khoe family, which has a lateral click. This and other words suggests that at least some Khoe clicks may have formed from consonant clusters when the first vowel of a word was lost; in this instance * > * > .
On the other side of the equation, several non-endangered languages in vigorous use demonstrate click loss. For example, the East Kalahari languages have lost clicks from a large percentage of their vocabulary, presumably due to Bantu influence. As a rule, a click is replaced by a consonant with close to the manner of articulation of the click and the place of articulation of the forward release: alveolar click releases (the family) tend to mutate into a velar stop or affricate, such as ; palatal clicks ( "etc.") tend to mutate into a palatal stop such as , or a post-alveolar affricate ; and dental clicks ( "etc.") tend to mutate into an alveolar affricate .
Clicks are often presented as difficult sounds to articulate within words. However, children acquire them readily; a two-year-old, for example, may be able to pronounce a word with a lateral click with no problem, but still be unable to pronounce . Lucy Lloyd reported that after long contact with the Khoi and San, it was difficult for her to refrain from using clicks when speaking English. | https://en.wikipedia.org/wiki?curid=7816 |
Consumer
A consumer is a person or a group who intends to order, orders, or uses purchased goods, products, or services primarily for personal, social, family, household and similar needs, not directly related to entrepreneurial or business activities.
“Consumers, by definition, include us all," President John F. Kennedy offered his definition to the United States Congress on March 15, 1962. This speech became the basis for the creation of World Consumer Rights Day, now celebrated on March 15. In his speech, JFK outlined the integral responsibility to consumers from their respective governments to help exercise consumers' rights, including:
A consumer is one that buys good for consumption and not for resale or commercial purpose. The consumer is an individual who pays some amount of money for the thing required to consume goods and services. As such, consumers play a vital role in the economic system of a capitalist economy. Without consumer demand, producers would lack one of the key motivations to produce: to sell to consumers. The consumer also forms part of the chain of distribution.
Recently in marketing instead of marketers generating broad demographic profiles and Fisio-graphic profiles of market segments, marketers have started to engage in personalized marketing, permission marketing, and mass customization.
Largely due to the rise of the Internet, consumers are shifting more and more towards becoming prosumer, consumers who are also producers (often of information and media on the social web), influence the products created (e.g. by customization, crowdfunding or publishing their preferences), actively participate in the production process, or use interactive products.
The law primarily uses a notion of the consumer in relation to consumer protection laws, and the definition of consumer is often restricted to living persons (i.e. not corporations or businesses) and excludes commercial users. A typical legal rationale for protecting the consumer is based on the notion of policing market failures and inefficiencies, such as inequalities of bargaining power between a consumer and a business. As all potential voters are also consumers, consumer protection has a clear political significance.
Concern over the interests of consumers has spawned consumer activism, where organized activists do research, education and advocacy to improve the offer of products and services. Consumer education has been incorporated into some school curricula. There are also various non-profit publications, such as "Which?", "Consumer Reports" and "Choice magazine", dedicated to assist in consumer education and decision making.
In India, the Consumer Protection Act 1986 differentiates the consummation of a commodity or service for personal use or to earn a livelihood. Only consumers are protected per this act and any person, entity or organization purchasing a commodity for commercial reasons are exempted from any benefits of this act. | https://en.wikipedia.org/wiki?curid=7818 |
Cactus
A cactus (plural cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word "cactus" derives, through Latin, from the Ancient Greek , a name originally used by Theophrastus for a spiny plant whose identity is now not certain. Cacti occur in a wide range of shapes and sizes. Most cacti live in habitats subject to at least some drought. Many live in extremely dry environments, even being found in the Atacama Desert, one of the driest places on earth. Cacti show many adaptations to conserve water. Almost all cacti are succulents, meaning they have thickened, fleshy parts adapted to store water. Unlike many other succulents, the stem is the only part of most cacti where this vital process takes place. Most species of cacti have lost true leaves, retaining only spines, which are highly modified leaves. As well as defending against herbivores, spines help prevent water loss by reducing air flow close to the cactus and providing some shade. In the absence of leaves, enlarged stems carry out photosynthesis. Cacti are native to the Americas, ranging from Patagonia in the south to parts of western Canada in the north—except for "Rhipsalis baccifera", which also grows in Africa and Sri Lanka.
Cactus spines are produced from specialized structures called areoles, a kind of highly reduced branch. Areoles are an identifying feature of cacti. As well as spines, areoles give rise to flowers, which are usually tubular and multipetaled. Many cacti have short growing seasons and long dormancies, and are able to react quickly to any rainfall, helped by an extensive but relatively shallow root system that quickly absorbs any water reaching the ground surface. Cactus stems are often ribbed or fluted, which allows them to expand and contract easily for quick water absorption after rain, followed by long drought periods. Like other succulent plants, most cacti employ a special mechanism called "crassulacean acid metabolism" (CAM) as part of photosynthesis. Transpiration, during which carbon dioxide enters the plant and water escapes, does not take place during the day at the same time as photosynthesis, but instead occurs at night. The plant stores the carbon dioxide it takes in as malic acid, retaining it until daylight returns, and only then using it in photosynthesis. Because transpiration takes place during the cooler, more humid night hours, water loss is significantly reduced.
Many smaller cacti have globe-shaped stems, combining the highest possible volume for water storage, with the lowest possible surface area for water loss from transpiration. The tallest free-standing cactus is "Pachycereus pringlei", with a maximum recorded height of , and the smallest is "Blossfeldia liliputiana", only about in diameter at maturity. A fully grown saguaro ("Carnegiea gigantea") is said to be able to absorb as much as of water during a rainstorm. A few species differ significantly in appearance from most of the family. At least superficially, plants of the genus "Pereskia" resemble other trees and shrubs growing around them. They have persistent leaves, and when older, bark-covered stems. Their areoles identify them as cacti, and in spite of their appearance, they, too, have many adaptations for water conservation. "Pereskia" is considered close to the ancestral species from which all cacti evolved. In tropical regions, other cacti grow as forest climbers and epiphytes (plants that grow on trees). Their stems are typically flattened, almost leaf-like in appearance, with fewer or even no spines, such as the well-known Christmas cactus or Thanksgiving cactus (in the genus "Schlumbergera").
Cacti have a variety of uses: many species are used as ornamental plants, others are grown for fodder or forage, and others for food (particularly their fruit). Cochineal is the product of an insect that lives on some cacti.
Many succulent plants in both the Old and New World – such as some Euphorbiaceae (euphorbias) – bear a striking resemblance to cacti, and may incorrectly be called "cactus" in common usage.
The 1,500 to 1,800 species of cacti mostly fall into one of two groups of "core cacti": opuntias (subfamily Opuntioideae) and "cactoids" (subfamily Cactoideae). Most members of these two groups are easily recognizable as cacti. They have fleshy succulent stems that are major organs of photosynthesis. They have absent, small, or transient leaves. They have flowers with ovaries that lie below the sepals and petals, often deeply sunken into a fleshy receptacle (the part of the stem from which the flower parts grow). All cacti have areoles—highly specialized short shoots with extremely short internodes that produce spines, normal shoots, and flowers.
The remaining cacti fall into only two genera, "Pereskia" and "Maihuenia", and are rather different, which means any description of cacti as a whole must frequently make exceptions for them. "Pereskia" species superficially resemble other tropical forest trees. When mature, they have woody stems that may be covered with bark and long-lasting leaves that provide the main means of photosynthesis. Their flowers may have superior ovaries (i.e., above the points of attachment of the sepals and petals), and areoles that produce further leaves. The two species of "Maihuenia" have small, globe-shaped bodies with prominent leaves at the top.
Cacti show a wide variety of growth habits, which are difficult to divide into clear, simple categories.
They can be tree-like (arborescent), meaning they typically have a single more-or-less woody trunk topped by several to many branches. In the genus "Pereskia", the branches are covered with leaves, so the species of this genus may not be recognized as cacti. In most other cacti, the branches are more typically cactus-like, bare of leaves and bark, and covered with spines, as in "Pachycereus pringlei" or the larger opuntias. Some cacti may become tree-sized but without branches, such as larger specimens of "Echinocactus platyacanthus". Cacti may also be described as shrubby, with several stems coming from the ground or from branches very low down, such as in "Stenocereus thurberi".
Smaller cacti may be described as columnar. They consist of erect, cylinder-shaped stems, which may or may not branch, without a very clear division into trunk and branches. The boundary between columnar forms and tree-like or shrubby forms is difficult to define. Smaller and younger specimens of "Cephalocereus senilis", for example, are columnar, whereas older and larger specimens may become tree-like. In some cases, the "columns" may be horizontal rather than vertical. Thus, "Stenocereus eruca" has stems growing along the ground, rooting at intervals.
Cacti whose stems are even smaller may be described as globular (or globose). They consist of shorter, more ball-shaped stems than columnar cacti. Globular cacti may be solitary, such as "Ferocactus latispinus", or their stems may form clusters that can create large mounds. All or some stems in a cluster may share a common root.
Other cacti have a quite different appearance. In tropical regions, some grow as forest climbers and epiphytes. Their stems are typically flattened, almost leaf-like in appearance, with fewer or even no spines. Climbing cacti can be very large; a specimen of "Hylocereus" was reported as long from root to the most distant stem. Epiphytic cacti, such as species of "Rhipsalis" or "Schlumbergera", often hang downwards, forming dense clumps where they grow in trees high above the ground.
The leafless, spiny stem is the characteristic feature of the majority of cacti (and all of those belonging to the largest subfamily, the Cactoideae). The stem is typically succulent, meaning it is adapted to store water. The surface of the stem may be smooth (as in some species of "Opuntia") or covered with protuberances of various kinds, which are usually called tubercles. These vary from small "bumps" to prominent, nipple-like shapes in the genus "Mammillaria" and outgrowths almost like leaves in "Ariocarpus" species. The stem may also be ribbed or fluted in shape. The prominence of these ribs depends on how much water the stem is storing: when full (up to 90% of the mass of a cactus may be water), the ribs may be almost invisible on the swollen stem, whereas when the cactus is short of water and the stems shrink, the ribs may be very visible.
The stems of most cacti are some shade of green, often bluish or brownish green. Such stems contain chlorophyll and are able to carry out photosynthesis; they also have stomata (small structures that can open and close to allow passage of gases). Cactus stems are often visibly waxy.
Areoles are structures unique to cacti. Although variable, they typically appear as woolly or hairy areas on the stems from which spines emerge. Flowers are also produced from areoles. In the genus "Pereskia", believed similar to the ancestor of all cacti, the areoles occur in the axils of leaves (i.e. in the angle between the leaf stalk and the stem). In leafless cacti, areoles are often borne on raised areas on the stem where leaf bases would have been.
Areoles are highly specialized and very condensed shoots or branches. In a normal shoot, nodes bearing leaves or flowers would be separated by lengths of stem (internodes). In an areole, the nodes are so close together, they form a single structure. The areole may be circular, elongated into an oval shape, or even separated into two parts; the two parts may be visibly connected in some way (e.g. by a groove in the stem) or appear entirely separate (a dimorphic areole). The part nearer the top of the stem then produces flowers, the other part spines. Areoles often have multicellular hairs (trichomes) that give the areole a hairy or woolly appearance, sometimes of a distinct color such as yellow or brown.
In most cacti, the areoles produce new spines or flowers only for a few years, and then become inactive. This results in a relatively fixed number of spines, with flowers being produced only from the ends of stems, which are still growing and forming new areoles. In "Pereskia", a genus close to the ancestor of cacti, areoles remain active for much longer; this is also the case in "Opuntia" and "Neoraimondia".
The great majority of cacti have no visible leaves; photosynthesis takes place in the stems (which may be flattened and leaflike in some species). Exceptions occur in three groups of cacti. All the species of "Pereskia" are superficially like normal trees or shrubs and have numerous leaves. Many cacti in the opuntia group (subfamily Opuntioideae, opuntioids) also have visible leaves, which may be long-lasting (as in "Pereskiopsis" species) or be produced only during the growing season and then be lost (as in many species of "Opuntia"). The small genus "Maihuenia" also relies on leaves for photosynthesis. The structure of the leaves varies somewhat between these groups. "Pereskia" species have "normal" leaves, with a midrib and a flattened blade (lamina) on either side. Opuntioids and "Maihuenia" have leaves that appear to consist only of a midrib.
Even those cacti without visible photosynthetic leaves do usually have very small leaves, less than long in about half of the species studied and almost always less than long. The function of such leaves cannot be photosynthesis; a role in the production of plant hormones, such as auxin, and in defining axillary buds has been suggested.
Botanically, "spines" are distinguished from "thorns": spines are modified leaves, and thorns are modified branches. Cacti produce spines, always from areoles as noted above. Spines are present even in those cacti with leaves, such as "Pereskia", "Pereskiopsis" and "Maihuenia", so they clearly evolved before complete leaflessness. Some cacti only have spines when young, possibly only when seedlings. This is particularly true of tree-living cacti, such as "Rhipsalis" and "Schlumbergera", but also of some ground-living cacti, such as "Ariocarpus".
The spines of cacti are often useful in identification, since they vary greatly between species in number, color, size, shape and hardness, as well as in whether all the spines produced by an areole are similar or whether they are of distinct kinds. Most spines are straight or at most slightly curved, and are described as hair-like, bristle-like, needle-like or awl-like, depending on their length and thickness. Some cacti have flattened spines (e.g. "Sclerocactus papyracanthus"). Other cacti have hooked spines. Sometimes, one or more central spines are hooked, while outer spines are straight (e.g., "Mammillaria rekoi").
In addition to normal-length spines, members of the subfamily Opuntioideae have relatively short spines, called glochids, that are barbed along their length and easily shed. These enter the skin and are difficult to remove due to being very fine and easily broken, causing long-lasting irritation.
Most ground-living cacti have only fine roots, which spread out around the base of the plant for varying distances, close to the surface. Some cacti have taproots; in genera such as "Copiapoa", these are considerably larger and of a greater volume than the body. Taproots may aid in stabilizing the larger columnar cacti. Climbing, creeping and epiphytic cacti may have only adventitious roots, produced along the stems where these come into contact with a rooting medium.
Like their spines, cactus flowers are variable. Typically, the ovary is surrounded by material derived from stem or receptacle tissue, forming a structure called a pericarpel. Tissue derived from the petals and sepals continues the pericarpel, forming a composite tube—the whole may be called a floral tube, although strictly speaking only the part furthest from the base is floral in origin. The outside of the tubular structure often has areoles that produce wool and spines. Typically, the tube also has small scale-like bracts, which gradually change into sepal-like and then petal-like structures, so the sepals and petals cannot be clearly differentiated (and hence are often called "tepals"). Some cacti produce floral tubes without wool or spines (e.g. "Gymnocalycium") or completely devoid of any external structures (e.g. "Mammillaria"). Unlike the flowers of other cacti, "Pereskia" flowers may be borne in clusters.
Cactus flowers usually have many stamens, but only a single style, which may branch at the end into more than one stigma. The stamens usually arise from all over the inner surface of the upper part of the floral tube, although in some cacti, the stamens are produced in one or more distinct "series" in more specific areas of the inside of the floral tube.
The flower as a whole is usually radially symmetrical (actinomorphic), but may be bilaterally symmetrical (zygomorphic) in some species. Flower colors range from white through yellow and red to magenta.
All cacti have some adaptations to promote efficient water use. Most cacti—opuntias and cactoids—specialize in surviving in hot and dry environments (i.e. they are xerophytes), but the first ancestors of modern cacti were already adapted to periods of intermittent drought. A small number of cactus species in the tribes Hylocereeae and Rhipsalideae have become adapted to life as climbers or epiphytes, often in tropical forests, where water conservation is less important.
The absence of visible leaves is one of the most striking features of most cacti. "Pereskia" (which is close to the ancestral species from which all cacti evolved) does have long-lasting leaves, which are, however, thickened and succulent in many species. Other species of cactus with long-lasting leaves, such as the opuntioid "Pereskiopsis", also have succulent leaves. A key issue in retaining water is the ratio of surface area to volume. Water loss is proportional to surface area, whereas the amount of water present is proportional to volume. Structures with a high surface area-to-volume ratio, such as thin leaves, necessarily lose water at a higher rate than structures with a low area-to-volume ratio, such as thickened stems.
Spines, which are modified leaves, are present on even those cacti with true leaves, showing the evolution of spines preceded the loss of leaves. Although spines have a high surface area-to-volume ratio, at maturity they contain little or no water, being composed of fibers made up of dead cells. Spines provide protection from herbivores and camouflage in some species, and assist in water conservation in several ways. They trap air near the surface of the cactus, creating a moister layer that reduces evaporation and transpiration. They can provide some shade, which lowers the temperature of the surface of the cactus, also reducing water loss. When sufficiently moist air is present, such as during fog or early morning mist, spines can condense moisture, which then drips onto the ground and is absorbed by the roots.
The majority of cacti are stem succulents, i.e., plants in which the stem is the main organ used to store water. Water may form up to 90% of the total mass of a cactus. Stem shapes vary considerably among cacti. The cylindrical shape of columnar cacti and the spherical shape of globular cacti produce a low surface area-to-volume ratio, thus reducing water loss, as well as minimizing the heating effects of sunlight. The ribbed or fluted stems of many cacti allow the stem to shrink during periods of drought and then swell as it fills with water during periods of availability. A mature saguaro ("Carnegiea gigantea") is said to be able to absorb as much as of water during a rainstorm. The outer layer of the stem usually has a tough cuticle, reinforced with waxy layers, which reduce water loss. These layers are responsible for the grayish or bluish tinge to the stem color of many cacti.
The stems of most cacti have adaptations to allow them to conduct photosynthesis in the absence of leaves. This is discussed further below under Metabolism.
Many cacti have roots that spread out widely, but only penetrate a short distance into the soil. In one case, a young saguaro only tall had a root system with a diameter of , but no more than deep. Cacti can also form new roots quickly when rain falls after a drought. The concentration of salts in the root cells of cacti is relatively high. All these adaptations enable cacti to absorb water rapidly during periods of brief or light rainfall. Thus, "Ferocactus cylindraceus" reportedly can take up a significant amount of water within 12 hours of as little as of rainfall, becoming fully hydrated in a few days.
Although in most cacti, the stem acts as the main organ for storing water, some cacti have in addition large taproots. These may be several times the length of the above-ground body in the case of species such as "Copiapoa atacamensis", which grows in one of the driest places in the world, the Atacama Desert in northern Chile.
Photosynthesis requires plants to take in carbon dioxide gas (). As they do so, they lose water through transpiration. Like other types of succulents, cacti reduce this water loss by the way in which they carry out photosynthesis. "Normal" leafy plants use the C3 mechanism: during daylight hours, is continually drawn out of the air present in spaces inside leaves and converted first into a compound containing three carbon atoms (3-phosphoglycerate) and then into products such as carbohydrates. The access of air to internal spaces within a plant is controlled by stomata, which are able to open and close. The need for a continuous supply of during photosynthesis means the stomata must be open, so water vapor is continuously being lost. Plants using the C3 mechanism lose as much as 97% of the water taken up through their roots in this way. A further problem is that as temperatures rise, the enzyme that captures starts to capture more and more oxygen instead, reducing the efficiency of photosynthesis by up to 25%.
Crassulacean acid metabolism (CAM) is a mechanism adopted by cacti and other succulents to avoid the problems of the C3 mechanism. In full CAM, the stomata open only at night, when temperatures and water loss are lowest. enters the plant and is captured in the form of organic acids stored inside cells (in vacuoles). The stomata remain closed throughout the day, and photosynthesis uses only this stored . CAM uses water much more efficiently at the price of limiting the amount of carbon fixed from the atmosphere and thus available for growth. CAM-cycling is a less efficient system whereby stomata open in the day, just as in plants using the C3 mechanism. At night, or when the plant is short of water, the stomata close and the CAM mechanism is used to store produced by respiration for use later in photosynthesis. CAM-cycling is present in "Pereskia" species.
By studying the ratio of 14C to 13C incorporated into a plant—its isotopic signature—it is possible to deduce how much is taken up at night and how much in the daytime. Using this approach, most of the "Pereskia" species investigated exhibit some degree of CAM-cycling, suggesting this ability was present in the ancestor of all cacti. "Pereskia" leaves are claimed to only have the C3 mechanism with CAM restricted to stems. More recent studies show that "it is highly unlikely that significant carbon assimilation occurs in the stem"; "Pereskia" species are described as having "C3 with inducible CAM." Leafless cacti carry out all their photosynthesis in the stem, using full CAM. , it is not clear whether stem-based CAM evolved once only in the core cacti, or separately in the opuntias and cactoids; CAM is known to have evolved convergently many times.
To carry out photosynthesis, cactus stems have undergone many adaptations. Early in their evolutionary history, the ancestors of modern cacti (other than one group of "Pereskia" species) developed stomata on their stems and began to delay developing bark. However, this alone was not sufficient; cacti with only these adaptations appear to do very little photosynthesis in their stems. Stems needed to develop structures similar to those normally found only in leaves. Immediately below the outer epidermis, a hypodermal layer developed made up of cells with thickened walls, offering mechanical support. Air spaces were needed between the cells to allow carbon dioxide to diffuse inwards. The center of the stem, the cortex, developed "chlorenchyma" – a plant tissue made up of relatively unspecialized cells containing chloroplasts, arranged into a "spongy layer" and a "palisade layer" where most of the photosynthesis occurs.
Naming and classifying cacti has been both difficult and controversial since the first cacti were discovered for science. The difficulties began with Carl Linnaeus. In 1737, he placed the cacti he knew into two genera, "Cactus" and "Pereskia". However, when he published "Species Plantarum" in 1753—the starting point for modern botanical nomenclature—he relegated them all to one genus, "Cactus". The word "cactus" is derived through Latin from the Ancient Greek ("kaktos"), a name used by Theophrastus for a spiny plant, which may have been the cardoon ("Cynara cardunculus").
Later botanists, such as Philip Miller in 1754, divided cacti into several genera, which, in 1789, Antoine Laurent de Jussieu placed in his newly created family Cactaceae. By the early 20th century, botanists came to feel Linnaeus's name "Cactus" had become so confused as to its meaning (was it the genus or the family?) that it should not be used as a genus name. The 1905 Vienna botanical congress rejected the name "Cactus" and instead declared "Mammillaria" was the type genus of the family Cactaceae. It did, however, conserve the name Cactaceae, leading to the unusual situation in which the family Cactaceae no longer contains the genus after which it was named.
The difficulties continued, partly because giving plants scientific names relies on "type specimens". Ultimately, if botanists want to know whether a particular plant is an example of, say, "Mammillaria mammillaris", they should be able to compare it with the type specimen to which this name is permanently attached. Type specimens are normally prepared by compression and drying, after which they are stored in herbaria to act as definitive references. However, cacti are very difficult to preserve in this way; they have evolved to resist drying and their bodies do not easily compress. A further difficulty is that many cacti were given names by growers and horticulturalists rather than botanists; as a result, the provisions of the "International Code of Nomenclature for algae, fungi, and plants" (which governs the names of cacti, as well as other plants) were often ignored. Curt Backeberg, in particular, is said to have named or renamed 1,200 species without one of his names ever being attached to a specimen, which, according to David Hunt, ensured he "left a trail of nomenclatural chaos that will probably vex cactus taxonomists for centuries."
In 1984, it was decided that the Cactaceae Section of the International Organization for Succulent Plant Study should set up a working party, now called the International Cactaceae Systematics Group (ICSG), to produce consensus classifications down to the level of genera. Their system has been used as the basis of subsequent classifications. Detailed treatments published in the 21st century have divided the family into around 125–130 genera and 1,400–1,500 species, which are then arranged into a number of tribes and subfamilies. The ICSG classification of the cactus family recognizes four subfamilies, the largest of which is divided into nine tribes. The subfamilies are:
Molecular phylogenetic studies have supported the monophyly of three of these subfamilies (not Pereskioideae), but have not supported all of the tribes or even genera below this level; indeed, a 2011 study found only 39% of the genera in the subfamily Cactoideae sampled in the research were monophyletic. Classification of the cacti currently remains uncertain and is likely to change.
A 2005 study suggested the genus "Pereskia" was basal within the Cactaceae, but confirmed earlier suggestions it was not monophyletic, i.e., did not include all the descendants of a common ancestor. The Bayesian consensus cladogram from this study is shown below.
A more recent 2011 study using fewer genes but more species also found that "Pereskia" was divided into these two clades, but was unable to resolve the members of the "core cacti" clade. It was accepted that the relationships shown above are "the most robust to date."
The two clades of "Pereskia" differ in their geographical distribution; with one exception, clade A is found around the Gulf of Mexico and the Caribbean Sea, whereas clade B occurs south of the Amazon Basin. Species of "Pereskia" within clade A always lack two key features of the stem present in most of the remaining "caulocacti": like most non-cacti, their stems begin to form bark early in the plants' life and also lack stomata—structures that control admission of air into a plant and hence control photosynthesis. By contrast, caulocacti, including species of "Pereskia" clade B, typically delay forming bark and have stomata on their stems, thus giving the stem the potential to become a major organ for photosynthesis. (The two highly specialized species of "Maihuenia" are something of an exception.)
The first cacti are thought to have been only slightly succulent shrubs or small trees whose leaves carried out photosynthesis. They lived in tropical areas that experienced periodic drought. If "Pereskia" clade A is a good model of these early cacti, then, although they would have appeared superficially similar to other trees growing nearby, they had already evolved strategies to conserve water (some of which are present in members of other families in the order Caryophyllales). These strategies included being able to respond rapidly to periods of rain, and keeping transpiration low by using water very efficiently during photosynthesis. The latter was achieved by tightly controlling the opening of stomata. Like "Pereskia" species today, early ancestors may have been able to switch from the normal C3 mechanism, where carbon dioxide is used continuously in photosynthesis, to CAM cycling, in which when the stomata are closed, carbon dioxide produced by respiration is stored for later use in photosynthesis.
"Pereskia" clade B marks the beginnings of an evolutionary switch to using stems as photosynthetic organs. Stems have stomata and the formation of bark takes place later than in normal trees. The "core cacti" show a steady increase in both stem succulence and photosynthesis accompanied by multiple losses of leaves, more-or-less complete in the Cactoideae. One evolutionary question at present unanswered is whether the switch to full CAM photosynthesis in stems occurred only once in the core cacti, in which case it has been lost in "Maihuenia", or separately in Opuntioideae and Cactoideae, in which case it never evolved in "Maihuenia".
Understanding evolution within the core cacti clade is difficult , since phylogenetic relationships are still uncertain and not well related to current classifications. Thus, a 2011 study found "an extraordinarily high proportion of genera" were not monophyletic, so were not all descendants of a single common ancestor. For example, of the 36 genera in the subfamily Cactoideae sampled in the research, 22 (61%) were found not monophyletic. Nine tribes are recognized within Cactoideae in the International Cactaceae Systematics Group (ICSG) classification; one, Calymmantheae, comprises a single genus, "Calymmanthium". Only two of the remaining eight – Cacteae and Rhipsalideae – were shown to be monophyletic in a 2011 study by Hernández-Hernández et al. For a more detailed discussion of the phylogeny of the cacti, see Classification of the Cactaceae.
No known fossils of cacti exist to throw light on their evolutionary history. However, the geographical distribution of cacti offers some evidence. Except for a relatively recent spread of "Rhipsalis baccifera" to parts of the Old World, cacti are plants of South America and mainly southern regions of North America. This suggests the family must have evolved after the ancient continent of Gondwana split into South America and Africa, which occurred during the Early Cretaceous, around . Precisely when after this split cacti evolved is less clear. Older sources suggest an early origin around 90 – 66 million years ago, during the Late Cretaceous. More recent molecular studies suggest a much younger origin, perhaps in very Late Eocene to early Oligocene periods, around 35–30 million years ago. Based on the phylogeny of the cacti, the earliest diverging group ("Pereskia" clade A) may have originated in Central America and northern South America, whereas the caulocacti, those with more-or-less succulent stems, evolved later in the southern part of South America, and then moved northwards. Core cacti, those with strongly succulent stems, are estimated to have evolved around 25 million years ago. A possible stimulus to their evolution may have been uplifting in the central Andes, some 25–20 million years ago, which was associated with increasing and varying aridity. However, the current species diversity of cacti is thought to have arisen only in the last 10–5 million years (from the late Miocene into the Pliocene). Other succulent plants, such as the Aizoaceae in South Africa, the Didiereaceae in Madagascar and the genus "Agave" in the Americas, appear to have diversified at the same time, which coincided with a global expansion of arid environments.
Cacti inhabit diverse regions, from coastal plains to high mountain areas. With one exception, they are native to the Americas, where their range extends from Patagonia to British Columbia and Alberta in western Canada. A number of centers of diversity exist. For cacti adapted to drought, the three main centers are Mexico and the southwestern United States; the southwestern Andes, where they are found in Peru, Bolivia, Chile and Argentina; and eastern Brazil, away from the Amazon Basin. Tree-living epiphytic and climbing cacti necessarily have different centers of diversity, as they require moister environments. They are mainly found in the coastal mountains and Atlantic forests of southeastern Brazil; in Bolivia, which is the center of diversity for the subfamily Rhipsalideae; and in forested regions of Central America, where the climbing Hylocereeae are most diverse.
"Rhipsalis baccifera" is the exception; it is native to both the Americas and the Old World, where it is found in tropical Africa, Madagascar, and Sri Lanka. One theory is it was spread by being carried as seeds in the digestive tracts of migratory birds; the seeds of "Rhipsalis" are adapted for bird distribution. Old World populations are polyploid, and regarded as distinct subspecies, supporting the idea that the spread was not recent. The alternative theory is the species initially crossed the Atlantic on European ships trading between South America and Africa, after which birds may have spread it more widely.
Many other species have become naturalized outside the Americas after having been introduced by people, especially in Australia, Hawaii, and the Mediterranean region. In Australia, species of "Opuntia", particularly "Opuntia stricta", were introduced in the 19th century for use as natural agricultural fences and in an attempt to establish a cochineal industry. They rapidly became a major weed problem, but are now controlled by biological agents, particularly the moth "Cactoblastis cactorum". The weed potential of Opuntia species in Australia continues however, leading to all opuntioid cacti except "O. ficus-indica" being declared Weeds of National Significance by the Australian Weeds Committee in April 2012.
Cactus flowers are pollinated by insects, birds and bats. None are known to be wind-pollinated and self-pollination occurs in only a very few species; for example the flowers of some species of "Frailea" do not open (cleistogamy). The need to attract pollinators has led to the evolution of pollination syndromes, which are defined as groups of "floral traits, including rewards, associated with the attraction and utilization of a specific group of animals as pollinators."
Bees are the most common pollinators of cacti; bee-pollination is considered to have been the first to evolve. Day-flying butterflies and nocturnal moths are associated with different pollination syndromes. Butterfly-pollinated flowers are usually brightly colored, opening during the day, whereas moth-pollinated flowers are often white or pale in color, opening only in the evening and at night. As an example, "Pachycereus schottii" is pollinated by a particular species of moth, "Upiga virescens", which also lays its eggs among the developing seeds its caterpillars later consume. The flowers of this cactus are funnel-shaped, white to deep pink, up to long, and open at night.
Hummingbirds are significant pollinators of cacti. Species showing the typical hummingbird-pollination syndrome have flowers with colors towards the red end of the spectrum, anthers and stamens that protrude from the flower, and a shape that is not radially symmetrical, with a lower lip that bends downwards; they produce large amounts of nectar with a relatively low sugar content. "Schlumbergera" species, such as "S. truncata", have flowers that correspond closely to this syndrome. Other hummingbird-pollinated genera include "Cleistocactus" and "Disocactus".
Bat-pollination is relatively uncommon in flowering plants, but about a quarter of the genera of cacti are known to be pollinated by bats—an unusually high proportion, exceeded among eudicots by only two other families, both with very few genera. Columnar cacti growing in semidesert areas are among those most likely to be bat-pollinated; this may be because bats are able to travel considerable distances, so are effective pollinators of plants growing widely separated from one another. The pollination syndrome associated with bats includes a tendency for flowers to open in the evening and at night, when bats are active. Other features include a relatively dull color, often white or green; a radially symmetrical shape, often tubular; a smell described as "musty"; and the production of a large amount of sugar-rich nectar. "Carnegiea gigantea" is an example of a bat-pollinated cactus, as are many species of "Pachycereus" and "Pilosocereus".
The fruits produced by cacti after the flowers have been fertilized vary considerably; many are fleshy, although some are dry. All contain a large number of seeds. Fleshy, colorful and sweet-tasting fruits are associated with seed dispersal by birds. The seeds pass through their digestive systems and are deposited in their droppings. Fruit that falls to the ground may be eaten by other animals; giant tortoises are reported to distribute "Opuntia" seeds in the Galápagos Islands. Ants appear to disperse the seeds of a few genera, such as "Blossfeldia". Drier spiny fruits may cling to the fur of mammals or be moved around by the wind.
, there is still controversy as to the precise dates when humans first entered those areas of the New World where cacti are commonly found, and hence when they might first have used them. An archaeological site in Chile has been dated to around 15,000 years ago, suggesting cacti would have been encountered before then. Early evidence of the use of cacti includes cave paintings in the Serra da Capivara in Brazil, and seeds found in ancient middens (waste dumps) in Mexico and Peru, with dates estimated at 12,000–9,000 years ago. Hunter-gatherers likely collected cactus fruits in the wild and brought them back to their camps.
It is not known when cacti were first cultivated. Opuntias (prickly pears) were used for a variety of purposes by the Aztecs, whose empire, lasting from the 14th to the 16th century, had a complex system of horticulture. Their capital from the 15th century was Tenochtitlan (now Mexico City); one explanation for the origin of the name is that it includes the Nahuatl word "nōchtli", referring to the fruit of an opuntia. The coat of arms of Mexico shows an eagle perched on a cactus while holding a snake, an image at the center of the myth of the founding of Tenochtitlan. The Aztecs symbolically linked the ripe red fruits of an opuntia to human hearts; just as the fruit quenches thirst, so offering human hearts to the sun god ensured the sun would keep moving.
Europeans first encountered cacti when they arrived in the New World late in the 15th century. Their first landfalls were in the West Indies, where relatively few cactus genera are found; one of the most common is the genus "Melocactus". Thus, melocacti were possibly among the first cacti seen by Europeans. "Melocactus" species were present in English collections of cacti before the end of the 16th century (by 1570 according to one source,) where they were called "Echinomelocactus", later shortened to "Melocactus" by Joseph Pitton de Tourneville in the early 18th century. Cacti, both purely ornamental species and those with edible fruit, continued to arrive in Europe, so Carl Linnaeus was able to name 22 species by 1753. One of these, his "Cactus opuntia" (now part of "Opuntia ficus-indica"), was described as "" (with larger fruit ... now in Spain and Portugal), indicative of its early use in Europe.
The plant now known as "Opuntia ficus-indica", or the Indian fig cactus, has long been an important source of food. The original species is thought to have come from central Mexico, although this is now obscure because the indigenous people of southern North America developed and distributed a range of horticultural varieties (cultivars), including forms of the species and hybrids with other opuntias. Both the fruit and pads are eaten, the former often under the Spanish name "tuna", the latter under the name "nopal". Cultivated forms are often significantly less spiny or even spineless. The nopal industry in Mexico was said to be worth US$150 million in 2007. The Indian fig cactus was probably already present in the Caribbean when the Spanish arrived, and was soon after brought to Europe. It spread rapidly in the Mediterranean area, both naturally and by being introduced—so much so, early botanists assumed it was native to the area. Outside the Americas, the Indian fig cactus is an important commercial crop in Sicily, Algeria and other North African countries. Fruits of other opuntias are also eaten, generally under the same name, "tuna". Flower buds, particularly of "Cylindropuntia" species, are also consumed.
Almost any fleshy cactus fruit is edible. The word "pitaya" or "pitahaya" (usually considered to have been taken into Spanish from Haitian creole) can be applied to a range of "scaly fruit", particularly those of columnar cacti. The fruit of the saguaro ("Carnegiea gigantea") has long been important to the indigenous peoples of northwestern Mexico and the southwestern United States, including the Sonoran Desert. It can be preserved by boiling to produce syrup and by drying. The syrup can also be fermented to produce an alcoholic drink. Fruits of "Stenocereus" species have also been important food sources in similar parts of North America; "Stenocereus queretaroensis" is cultivated for its fruit. In more tropical southern areas, the climber "Hylocereus undatus" provides "pitahaya orejona", now widely grown in Asia under the name dragon fruit. Other cacti providing edible fruit include species of "Echinocereus", "Ferocactus", "Mammillaria", "Myrtillocactus", "Pachycereus", "Peniocereus" and "Selenicereus". The bodies of cacti other than opuntias are less often eaten, although Anderson reported that "Neowerdermannia vorwerkii" is prepared and eaten like potatoes in upland Bolivia.
A number of species of cacti have been shown to contain psychoactive agents, chemical compounds that can cause changes in mood, perception and cognition through their effects on the brain. Two species have a long history of use by the indigenous peoples of the Americas: peyote, "Lophophora williamsii", in North America, and the San Pedro cactus, "Echinopsis pachanoi", in South America. Both contain mescaline.
"L. williamsii" is native to northern Mexico and southern Texas. Individual stems are about high with a diameter of , and may be found in clumps up to wide. A large part of the stem is usually below ground. Mescaline is concentrated in the photosynthetic portion of the stem above ground. The center of the stem, which contains the growing point (the apical meristem), is sunken. Experienced collectors of peyote remove a thin slice from the top of the plant, leaving the growing point intact, thus allowing the plant to regenerate. Evidence indicates peyote was in use more than 5,500 years ago; dried peyote buttons presumed to be from a site on the Rio Grande, Texas, were radiocarbon dated to around 3780–3660 BC. Peyote is perceived as a means of accessing the spirit world. Attempts by the Roman Catholic church to suppress its use after the Spanish conquest were largely unsuccessful, and by the middle of the 20th century, peyote was more widely used than ever by indigenous peoples as far north as Canada. It is now used formally by the Native American Church.
"Echinopsis pachanoi" is native to Ecuador and Peru. It is very different in appearance from "L. williamsii". It has tall stems, up to high, with a diameter of , which branch from the base, giving the whole plant a shrubby or tree-like appearance. Archaeological evidence of the use of this cactus appears to date back to 2,000–2,300 years ago, with carvings and ceramic objects showing columnar cacti. Although church authorities under the Spanish attempted to suppress its use, this failed, as shown by the Christian element in the common name "San Pedro cactus"—Saint Peter cactus. Anderson attributes the name to the belief that just as St Peter holds the keys to heaven, the effects of the cactus allow users "to reach heaven while still on earth." It continues to be used for its psychoactive effects, both for spiritual and for healing purposes, often combined with other psychoactive agents, such as "Datura ferox" and tobacco. Several other species of "Echinopsis", including "E. peruviana", also contain mescaline.
Cacti were cultivated as ornamental plants from the time they were first brought from the New World. By the early 1800s, enthusiasts in Europe had large collections (often including other succulents alongside cacti). Rare plants were sold for very high prices. Suppliers of cacti and other succulents employed collectors to obtain plants from the wild, in addition to growing their own. In the late 1800s, collectors turned to orchids, and cacti became less popular, although never disappearing from cultivation.
Cacti are often grown in greenhouses, particularly in regions unsuited to the cultivation of cacti outdoors, such the northern parts of Europe and North America. Here, they may be kept in pots or grown in the ground. Cacti are also grown as houseplants, many being tolerant of the often dry atmosphere. Cacti in pots may be placed outside in the summer to ornament gardens or patios, and then kept under cover during the winter. Less drought-resistant epiphytes, such as epiphyllum hybrids, "Schlumbergera" (the Thanksgiving or Christmas cactus) and "Hatiora" (the Easter cactus), are widely cultivated as houseplants.
Cacti may also be planted outdoors in regions with suitable climates. Concern for water conservation in arid regions has led to the promotion of gardens requiring less watering (xeriscaping). For example, in California, the East Bay Municipal Utility District sponsored the publication of a book on plants and landscapes for summer-dry climates. Cacti are one group of drought-resistant plants recommended for dry landscape gardening.
Cacti have many other uses. They are used for human food and as fodder for animals, usually after burning off their spines. In addition to their use as psychoactive agents, some cacti are employed in herbal medicine. The practice of using various species of "Opuntia" in this way has spread from the Americas, where they naturally occur, to other regions where they grow, such as India.
Cochineal is a red dye produced by a scale insect that lives on species of "Opuntia". Long used by the peoples of Central and North America, demand fell rapidly when European manufacturers began to produce synthetic dyes in the middle of the 19th century. Commercial production has now increased following a rise in demand for natural dyes.
Cacti are used as construction materials. Living cactus fences are employed as barricades around buildings to prevent people breaking in. They also used to corral animals. The woody parts of cacti, such as "Cereus repandus" and "Echinopsis atacamensis", are used in buildings and in furniture. The frames of wattle and daub houses built by the Seri people of Mexico may use parts of "Carnegiea gigantea". The very fine spines and hairs (trichomes) of some cacti were used as a source of fiber for filling pillows and in weaving.
All cacti are included in Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which "lists species that are not necessarily now threatened with extinction but that may become so unless trade is closely controlled." Control is exercised by making international trade in most specimens of cacti illegal unless permits have been issued, at least for exports. Some exceptions are allowed, e.g., for "naturalized or artificially propagated plants". Some cacti, such as all "Ariocarpus" and "Discocactus" species, are included in the more restrictive Appendix I, used for the "most endangered" species. These may only be moved between countries for scientific purposes, and only then when accompanied by both export and import permits.
The three main threats to cacti in the wild are development, grazing and over-collection. Development takes many forms. The construction of a dam near Zimapan, Mexico, caused the destruction of a large part of the natural habitat of "Echinocactus grusonii". Urban development and highways have destroyed cactus habitats in parts of Mexico, New Mexico and Arizona, including the Sonoran Desert. The conversion of land to agriculture has affected populations of "Ariocarpus kotschoubeyanus" in Mexico, where dry plains were plowed for maize cultivation, and of "Copiapoa" and "Eulychnia" in Chile, where valley slopes were planted with vines. Grazing, in many areas by introduced animals, such as goats, has caused serious damage to populations of cacti (as well as other plants); two examples cited by Anderson are the Galápagos Islands generally and the effect on "Browningia candelaris" in Peru. Over-collection of cacti for sale has greatly affected some species. For example, the type locality of "Pelecyphora strobiliformis" near Miquihuana, Mexico, was virtually denuded of plants, which were dug up for sale in Europe. Illegal collecting of cacti from the wild continues to pose a threat.
Conservation of cacti can be "in situ" or "ex situ". "In situ" conservation involves preserving habits through enforcement of legal protection and the creation of specially protected areas such as national parks and reserves. Examples of such protected areas in the United States include Big Bend National Park, Texas; Joshua Tree National Park, California; and Saguaro National Park, Arizona. Latin American examples include Parque Nacional del Pinacate, Sonora, Mexico and Pan de Azúcar National Park, Chile. "Ex situ" conservation aims to preserve plants and seeds outside their natural habitats, often with the intention of later reintroduction. Botanical gardens play an important role in "ex situ" conservation; for example, seeds of cacti and other succulents are kept in long-term storage at the Desert Botanical Garden, Arizona.
The popularity of cacti means many books are devoted to their cultivation. Cacti naturally occur in a wide range of habitats and are then grown in many countries with different climates, so precisely replicating the conditions in which a species normally grows is usually not practical. A broad distinction can be made between semidesert cacti and epiphytic cacti, which need different conditions and are best grown separately. This section is primarily concerned with the cultivation of semidesert cacti in containers and under protection, such as in a greenhouse or in the home, rather than cultivation outside in the ground in those climates that permit it. For the cultivation of epiphytic cacti, see Cultivation of "Schlumbergera" (Christmas or Thanksgiving cacti), and Cultivation of epiphyllum hybrids.
The purpose of the growing medium is to provide support and to store water, oxygen and dissolved minerals to feed the plant. In the case of cacti, there is general agreement that an open medium with a high air content is important. When cacti are grown in containers, recommendations as to how this should be achieved vary greatly; Miles Anderson says that if asked to describe a perfect growing medium, "ten growers would give 20 different answers". Roger Brown suggests a mixture of two parts commercial soilless growing medium, one part hydroponic clay and one part coarse pumice or perlite, with the addition of soil from earthworm castings. The general recommendation of 25–75% organic-based material, the rest being inorganic such as pumice, perlite or grit, is supported by other sources. However, the use of organic material is rejected altogether by others; Hecht says that cacti (other than epiphytes) "want soil that is low in or free of humus", and recommends coarse sand as the basis of a growing medium.
Semi-desert cacti need careful watering. General advice is hard to give, since the frequency of watering required depends on where the cacti are being grown, the nature of the growing medium, and the original habitat of the cacti. Brown says that more cacti are lost through the "untimely application of water than for any other reason" and that even during the dormant winter season, cacti need some water. Other sources say that water can be withheld during winter (November to March in the Northern Hemisphere). Another issue is the hardness of the water; where it is necessary to use hard water, regular re-potting is recommended to avoid the build up of salts. The general advice given is that during the growing season, cacti should be allowed to dry out between thorough waterings. A water meter can help in determining when the soil is dry.
Although semi-desert cacti may be exposed to high light levels in the wild, they may still need some shading when subjected to the higher light levels and temperatures of a greenhouse in summer. Allowing the temperature to rise above is not recommended. The minimum winter temperature required depends very much on the species of cactus involved. For a mixed collection, a minimum temperature of between and is often suggested, except for cold-sensitive genera such as "Melocactus" and "Discocactus". Some cacti, particularly those from the high Andes, are fully frost-hardy when kept dry (e.g. "Rebutia minuscula" survives temperatures down to in cultivation) and may flower better when exposed to a period of cold.
Cacti can be propagated by seed, cuttings or grafting. Seed sown early in the year produces seedlings that benefit from a longer growing period. Seed is sown in a moist growing medium and then kept in a covered environment, until 7–10 days after germination, to avoid drying out. A very wet growing medium can cause both seeds and seedlings to rot. A temperature range of is suggested for germination; soil temperatures of around promote the best root growth. Low light levels are sufficient during germination, but afterwards semi-desert cacti need higher light levels to produce strong growth, although acclimatization is needed to conditions in a greenhouse, such as higher temperatures and strong sunlight.
Reproduction by cuttings makes use of parts of a plant that can grow roots. Some cacti produce "pads" or "joints" that can be detached or cleanly cut off. Other cacti produce offsets that can be removed. Otherwise, stem cuttings can be made, ideally from relatively new growth. It is recommended that any cut surfaces be allowed to dry for a period of several days to several weeks until a callus forms over the cut surface. Rooting can then take place in an appropriate growing medium at a temperature of around .
Grafting is used for species difficult to grow well in cultivation or that cannot grow independently, such as some chlorophyll-free forms with white, yellow or red bodies, or some forms that show abnormal growth (e.g., cristate or forms). For the host plant (the stock), growers choose one that grows strongly in cultivation and is compatible with the plant to be propagated: the scion. The grower makes cuts on both stock and scion and joins the two, binding them together while they unite. Various kinds of graft are used—flat grafts, where both scion and stock are of similar diameters, and cleft grafts, where a smaller scion is inserted into a cleft made in the stock.
Commercially, huge numbers of cacti are produced annually. For example, in 2002 in Korea alone, 49 million plants were propagated, with a value of almost US$9 million. Most of them (31 million plants) were propagated by grafting.
A range of pests attack cacti in cultivation. Those that feed on sap include mealybugs, living on both stems and roots; scale insects, generally only found on stems; whiteflies, which are said to be an "infrequent" pest of cacti; red spider mites, which are very small but can occur in large numbers, constructing a fine web around themselves and badly marking the cactus via their sap sucking, even if they do not kill it; and thrips, which particularly attack flowers. Some of these pests are resistant to many insecticides, although there are biological controls available. Roots of cacti can be eaten by the larvae of sciarid flies and fungus gnats. Slugs and snails also eat cacti.
Fungi, bacteria and viruses attack cacti, the first two particularly when plants are over-watered. Fusarium rot can gain entry through a wound and cause rotting accompanied by red-violet mold. ""Helminosporium" rot" is caused by "Bipolaris cactivora" ( "Helminosporium cactivorum"); "Phytophthora" species also cause similar rotting in cacti. Fungicides may be of limited value in combating these diseases. Several viruses have been found in cacti, including cactus virus X. These appear to cause only limited visible symptoms, such as chlorotic (pale green) spots and mosaic effects (streaks and patches of paler color). However, in an "Agave" species, cactus virus X has been shown to reduce growth, particularly when the roots are dry. There are no treatments for virus diseases. | https://en.wikipedia.org/wiki?curid=7819 |
Civilian Conservation Corps
The Civilian Conservation Corps (CCC) was a voluntary public work relief program that operated from 1933 to 1942 in the United States for unemployed, unmarried men. Originally for young men ages 18–25, it was eventually expanded to ages 17–28. Robert Fechner was the first director of this agency, succeeded by James McEntee following Fechner's death. The CCC was a major part of President Franklin D. Roosevelt's New Deal that provided manual labor jobs related to the conservation and development of natural resources in rural lands owned by federal, state, and local governments. The CCC was designed to provide jobs for young men and to relieve families who had difficulty finding jobs during the Great Depression in the United States. Maximum enrollment at any one time was 300,000. Through the course of its nine years in operation, 3 million young men participated in the CCC, which provided them with shelter, clothing, and food, together with a wage of $30 () per month ($25 of which had to be sent home to their families).
The American public made the CCC the most popular of all the New Deal programs. Sources written at the time claimed an individual's enrollment in the CCC led to improved physical condition, heightened morale, and increased employability. The CCC also led to a greater public awareness and appreciation of the outdoors and the nation's natural resources, and the continued need for a carefully planned, comprehensive national program for the protection and development of natural resources.
The CCC operated separate programs for veterans and Native Americans. Approximately 15,000 Native Americans participated in the program, helping them weather the Great Depression.
By 1942, with World War II and the draft in operation, the need for work relief declined, and Congress voted to close the program.
As governor of New York, Franklin Delano Roosevelt had run a similar program on a much smaller scale, known as the Temporary Emergency Relief Administration (TERA). It was started in early 1932 to "use men from the lists of the unemployed to improve our existing reforestation areas". Within its first year alone, more than 25,000 unemployed New Yorkers would be active in its paid conservation work. Long interested in conservation, as president, he proposed to Congress a full-scale national program on March 21, 1933:
He promised this law would provide 250,000 young men with meals, housing, workwear, and medical care for working in the national forests and other government properties. The Emergency Conservation Work (ECW) Act was introduced to Congress the same day and enacted by voice vote on March 31. Roosevelt issued Executive Order 6101 on April 5, 1933, which established the CCC organization and appointed a director, Robert Fechner, a former labor union official who served until 1939. The organization and administration of the CCC was a new experiment in operations for a federal government agency. The order indicated that the program was to be supervised jointly by four government departments: Labor, which recruited the young men, War, which operated the camps, and Agriculture and Interior, which organized and supervised the work projects. A CCC Advisory Council was composed of a representative from each of the supervising departments. In addition, the Office of Education and Veterans Administration participated in the program. To end the opposition from labor unions (which wanted no training programs started when so many of their men were unemployed) Roosevelt chose Robert Fechner, vice president of the International Association of Machinists and Aerospace Workers, as director of the corps. William Green, head of the American Federation of Labor, was taken to the first camp to demonstrate that there would be no job training involved beyond simple manual labor.
Reserve officers from the U.S. Army were in charge of the camps, but there was no military training. General Douglas MacArthur was placed in charge of the program but said that the number of Army officers and soldiers assigned to the camps was affecting the readiness of the Regular Army. However, the Army also found numerous benefits in the program. When the draft began in 1940, the policy was to make CCC alumni corporals and sergeants. The CCC also provided command experience to Organized Reserve Corps officers. George Marshall had "embraced" the CCC, unlike many of his brother officers.
Through the CCC, the Regular Army could assess the leadership performance of both Regular and Reserve officers. The CCC provided lessons which the Army used in developing its wartime and mobilization plans for training camps.
An implicit goal of the CCC was to restore morale in an era of 25% unemployment for all men and much higher rates for poorly educated teenagers. Jeffrey Suzik argues in "'Building Better Men':
The CCC Boy and the Changing Social Ideal of Manliness" that the CCC provided work, pay, and an ideology of robust outdoor manhood to counter the Depression's effeminacy, as well as cash to help the family budget. Through a regime of heavy manual labor, civic and political education, and an all-male living and working environment, the CCC tried to build "better men" who would be economically independent and not effete. By 1939 there was a shift from the athletic manual worker to the highly trained citizen soldier ready for the war.
The legislation and mobilization of the program occurred quite rapidly. Roosevelt made his request to Congress on March 21, 1933; the legislation was submitted to Congress the same day; Congress passed it by voice vote on March 31; Roosevelt signed it the same day, then issued an executive order on April 5 creating the agency, appointing its director (Fechner), and assigning War Department corps area commanders to begin enrollment. The first CCC enrollee was selected April 8, and subsequent lists of unemployed men were supplied by state and local welfare and relief agencies for immediate enrollment. On April 17, the first camp, NF-1, Camp Roosevelt, was established at George Washington National Forest near Luray, Virginia. On June 18, the first of 161 soil erosion control camps was opened, in Clayton, Alabama. By July 1, 1933 there were 1,463 working camps with 250,000 junior enrollees (18–25 years of age); 28,000 veterans; 14,000 American Indians; and 25,000 adults in the Locally Men (LEM) program.
The typical CCC enrollee was a U.S. citizen, unmarried, unemployed male, 18–25 years of age. Normally his family was on local relief. Each enrollee volunteered and, upon passing a physical exam and/or a period of conditioning, was required to serve a minimum six-month period, with the option to serve as many as four periods, or up to two years, if employment outside the Corps was not possible. Enrollees worked 40 hours per week over five days, sometimes including Saturdays if poor weather dictated. In return they received $30 per month () with a compulsory allotment of $22–25 (about ) sent to a family dependent, as well as housing, food, clothing, and medical care.
Following the second Bonus Army march on Washington D.C., President Roosevelt amended the CCC program on May 11, 1933, to include work opportunities for veterans. Veteran qualifications differed from the junior enrollee; one needed to be certified by the Veterans Administration by an application. They could be any age, and married or single as long as they were in need of work. Veterans were generally assigned to entire veteran camps. Enrollees were eligible for the following "rated" positions to help with camp administration: senior leader, mess steward, storekeeper and two cooks; assistant leader, company clerk, assistant educational advisor and three second cooks. These men received additional pay ranging from $36 to $45 per month depending on their rating.
Each CCC camp was located in the area of particular conservation work to be performed and organized around a complement of up to 200 civilian enrollees in a designated numbered "company" unit. The CCC camp was a temporary community in itself, structured to have barracks (initially Army tents) for 50 enrollees each, officer/technical staff quarters, medical dispensary, mess hall, recreation hall, educational building, lavatory and showers, technical/administrative offices, tool room/blacksmith shop and motor pool garages.
The company organization of each camp had a dual-authority supervisory staff: firstly, Department of War personnel or Reserve officers (until July 1, 1939), a "company commander" and junior officer, who were responsible for overall camp operation, logistics, education and training; and secondly, ten to fourteen technical service civilians, including a camp "superintendent" and "foreman", employed by either the Departments of Interior or Agriculture, responsible for the particular fieldwork. Also included in camp operation were several non-technical supervisor LEMs, who provided knowledge of the work at hand, "lay of the land," and paternal guidance for inexperienced enrollees. Enrollees were organized into work detail units called "sections" of 25 men each, according to the barracks they resided in. Each section had an enrollee "senior leader" and "assistant leader" who were accountable for the men at work and in the barracks.
The CCC performed 300 types of work projects within ten approved general classifications:
The responses to this seven-month experimental conservation program were enthusiastic. On October 1, 1933, Director Fechner was directed to arrange for the second period of enrollment. By January 1934, 300,000 men were enrolled. In July 1934, this cap was increased by 50,000 to include men from Midwest states that had been affected by drought. The temporary tent camps had also developed to include wooden barracks. An education program had been established, emphasizing job training and literacy.
Approximately 55% of enrollees were from rural communities, a majority of which were non-farm; 45% came from urban areas. Level of education for the enrollee averaged 3% illiterate; 38% had less than eight years of school; 48% did not complete high school; and 11% were high school graduates. At the time of entry, 70% of enrollees were malnourished and poorly clothed. Few had work experience beyond occasional odd jobs. Peace was maintained by the threat of "dishonorable discharge". "This is a training station; we're going to leave morally and physically fit to lick 'Old Man Depression,'" boasted the newsletter, "Happy Days," of a North Carolina camp.
Because of the power of the Solid South white Democrats in Congress, who insisted on racial segregation, the New Deal programs were racially segregated; blacks and whites rarely worked alongside each other. At this time, all the states of the South had passed legislation imposing racial segregation and, since the turn of the century, laws and constitutional provisions that disenfranchised most blacks; they were excluded from formal politics. Because of discrimination by white officials at the local and state levels, blacks in the South did not receive as many benefits as whites from New Deal programs.
In the first few weeks of operation, CCC camps in the North were integrated. By July 1935, however, all the camps in the United States were segregated. Enrollment peaked at the end of 1935, when there were 500,000 men located in 2,600 camps in operation in all states and received equal pay and housing. Black leaders lobbied to secure leadership roles. Adult white men held the major leadership roles in all the camps. Director Fechner refused to appoint black adults to any supervisory positions except that of education director in the all-black camps.
The CCC operated a separate division for members of federally recognized tribes: the "Indian Emergency Conservation Work" (IECW or CCC-ID). Native men from reservations worked on roads, bridges, clinics, shelters, and other public works near their reservations. Although they were organized as groups classified as camps, no permanent camps were established for Native Americans. Instead, organized groups moved with their families from project to project and were provided with an additional rental allowance in their pay. The CCC often provided the only paid work, as many reservations were in remote rural areas. Enrollees had to be between the ages of 17 and 35.
During 1933, about half the male heads of households on the Sioux reservations in South Dakota were employed by the CCC-ID. With grants from the Public Works Administration (PWA), the Indian Division built schools and conducted an extensive road-building program in and around many reservations to improve infrastructure. The mission was to reduce erosion and improve the value of Indian lands. Crews built dams of many types on creeks, then sowed grass on the eroded areas from which the damming materials had been taken. They built roads and planted shelter-belts on federal lands. The steady income helped participants regain self-respect, and many used the funds to improve their lives. John Collier, the federal Commissioner of Indian Affairs and Daniel Murphy, the director of the CCC-ID, both based the program on Indian self-rule and the restoration of tribal lands, governments, and cultures. The next year, Congress passed the Indian Reorganization Act of 1934, which ended allotments and helped preserve tribal lands, and encouraged tribes to re-establish self-government.
Collier said of the CCC-Indian Division, "no previous undertaking in Indian Service has so largely been the Indians' own undertaking". Education programs also trained participants in gardening, stock raising, safety, native arts, and some academic subjects. IECW differed from other CCC activities in that it explicitly trained men in skills to be carpenters, truck drivers, radio operators, mechanics, surveyors, and technicians. With the passage of the National Defense Vocational Training Act of 1941, enrollees began participating in defense-oriented training. The government paid for the classes and after individuals completed courses and passed a competency test, guaranteed automatic employment in the defense work. A total of 85,000 Native Americans were enrolled in this training. This proved valuable social capital for the 24,000 alumni who later served in the military and the 40,000 who left the reservations for city jobs supporting the war effort.
Responding to favorable public opinion to alleviate unemployment, Congress approved the Emergency Relief Appropriation Act of 1935, on April 8, 1935, which included continued funding for the CCC program through March 31, 1937. The age limit was expanded to 18–28 to include more men. From April 1, 1935 to March 31, 1936 was the period of greatest activity and work accomplished by the CCC program. Enrollment had peaked at 505,782 in about 2,900 camps by August 31, 1935, followed by a reduction to 350,000 enrollees in 2,019 camps by June 30, 1936. During this period the public response to the CCC program was overwhelmingly popular. A Gallup poll of April 18, 1936, asked: "Are you in favor of the CCC camps?"; 82% of respondents said yes, including 92% of Democrats and 67% of Republicans.
On June 28, 1937, the Civilian Conservation Corps was legally established and transferred from its original designation as the Emergency Conservation Work program. Funding was extended for three more years by Public Law No. 163, 75th Congress, effective July 1, 1937. Congress changed the age limits to 17–23 years old and changed the requirement that enrollees be on relief to "not regularly in attendance at school, or possessing full-time employment." The 1937 law mandated the inclusion of vocational and academic training for a minimum of 10 hours per week. Students in school were allowed to enroll during summer vacation. During this period, the CCC forces contributed to disaster relief following 1937 floods in New York, Vermont, and the Ohio and Mississippi river valleys, and response and clean-up after the 1938 hurricane in New England.
In 1939 Congress ended the independent status of the CCC, transferring it to the control of the Federal Security Agency. The National Youth Administration, U.S. Employment Service, the Office of Education, and the Works Progress Administration also had some responsibilities. About 5,000 Reserve officers for the camps were affected, as they were transferred to federal Civil Service, and military ranks and titles were eliminated. Despite the loss of overt military leadership in the camps by July 1940, with war underway in Europe and Asia, the government directed an increasing number of CCC projects on resources for national defense. It developed infrastructure for military training facilities and forest protection. By 1940 the CCC was no longer wholly a relief agency, was rapidly losing its non-military character, and it was becoming a system for work-training, as its ranks had become increasingly younger, with little experience.
Although the CCC was probably the most popular New Deal program, it never was authorized as a permanent agency. The program was reduced in scale as the Depression waned and employment opportunities improved. After conscription began in 1940, fewer eligible young men were available. Following the attack on Pearl Harbor in December 1941, the Roosevelt administration directed all federal programs to emphasize the war effort. Most CCC work, except for wildland firefighting, was shifted onto U.S. military bases to help with construction.
The CCC disbanded one year earlier than planned, as the 77th United States Congress ceased funding it. Operations were formally concluded at the end of the federal fiscal year on June 30, 1942. The end of the CCC program and closing of the camps involved arrangements to leave the incomplete work projects in the best possible state, the separation of about 1,800 appointed employees, the transfer of CCC property to the War and Navy Departments and other agencies, and the preparation of final accountability records. Liquidation of the CCC was ordered by Congress by the Labor-Federal Security Appropriation Act (56 Stat. 569) on July 2, 1942; and virtually completed on June 30, 1943. Liquidation appropriations for the CCC continued through April 20, 1948.
Some former CCC sites in good condition were reactivated from 1941 to 1947 as Civilian Public Service camps where conscientious objectors performed "work of national importance" as an alternative to military service. Other camps were used to hold Japanese, German and Italian Americans interned under the Western Defense Command's Enemy Alien Control Program, as well as Axis prisoners of war. Most of the Japanese American internment camps were built by the people held there. After the CCC disbanded, the federal agencies responsible for public lands organized their own seasonal fire crews, modeled after the CCC. These have performed a firefighting function formerly done by the CCC and provided the same sort of outdoor work experience for young people. Approximately 47 young men have died while in this line of duty.
In several cities where CCC workers worked, statues were erected to commemorate them.
The CCC program was never officially terminated. Congress provided funding for closing the remaining camps in 1942 with the equipment being reallocated. It became a model for conservation programs that were implemented in the period after World War II. Present-day corps are national, state, and local programs that engage primarily youth and young adults (ages 16–25) in community service, training, and educational activities. The nation's approximately 113 corps programs operate in 41 states and the District of Columbia. During 2004, they enrolled more than 23,000 young people. The Corps Network, known originally as the National Association of Service and Conservation Corps (NASCC), works to expand and enhance corps-type programs throughout the country. The Corps Network began in 1985 when the nation's first 24 Corps directors banded together to secure an advocate at the federal level and a repository of information on how best to start and manage a corps. Early financial assistance from the Ford, Hewlett and Mott Foundations was critical to establishing the association.
Another similar program is the National Civilian Community Corps, part of the AmeriCorps program, a team-based national service program in which young adults ages 18–24 spend 10 months working for non-profit and government organizations.
The CCC program became a model for the creation of team-based national service youth conservation programs such as the Student Conservation Association (SCA). The SCA, founded in 1959, is a nonprofit organization that offers conservation internships and summer trail crew opportunities to more than 4,000 people each year. The SCA mission is to build a new generation of conservation managers by inspiring lifelong stewardship of the environment and communities by engaging high school and college-age volunteers in hands-on service to the land. SCA program is active nationwide in the US, including national and state parks, forests, wildlife refuges, seashores and historic sites. SCA National Headquarters is located in Charlestown, New Hampshire, with regional offices across the country.
In 1976, Governor of California Jerry Brown established the California Conservation Corps. This program had many similar characteristics - residential centers, high expectations for participation, and emphasis on hard work on public lands. Young adults from different backgrounds were recruited for a term of one year. Corps members attended a training session called the Corpsmember Orientation Motivation Education and Training (COMET) program before being assigned to one of the various centers. Project work is also similar to the original CCC of the 1930s - work on public forests, state and federal parks.
Established in 1995, Environmental Corps, now Texas Conservation Corps (TxCC), is an American YouthWorks program which allows youth, ages 17 to 28, to contribute to the restoration and preservation of parks and public lands in Texas. The only conservation corps in Texas, TxcC is a nonprofit corporation based in Austin, Texas, which serves the entire state. Their work ranges from disaster relief to trail building to habitat restoration. TxCC has done projects in national, state, and city parks.
The Montana Conservation Corps (MCC) is a non-profit organization with a mission to equip young people with the skills and values to be vigorous citizens who improve their communities and environment. Collectively, MCC crews contribute more than 90,000 work hours each year. The MCC was established in 1991 by Montana's Human Resource Development Councils in Billings, Bozeman and Kalispell. Originally, it was a summer program for disadvantaged youth, although it has grown into an AmeriCorps-sponsored non-profit organization with six regional offices that serve Montana, Idaho, Wyoming, North Dakota, and South Dakota. All regions also offer Montana YES (Youth Engaged in Service) summer programs for teenagers who are 14 to 17 years old.
The Washington Conservation Corps (WCC) is a sub-agency of the Washington State Department of Ecology. It employs men and women 18 to 25 years old in a program to protect and enhance Washington's natural resources. WCC is a part of the AmeriCorps program.
Conservation Corps Minnesota & Iowa provides environmental stewardship and service-learning opportunities to youth and young adults while accomplishing conservation, natural resource management projects and emergency response work through its Young Adult Program and the Summer Youth Program. These programs emphasize the development of job and life skills by conservation and community service work.
The Vermont Youth Conservation Corps (VYCC) is a non-profit, youth service and education organization that hires Corps Members, aged 16–24, to work on high-priority conservation projects in Vermont. Through these work projects, Corps Members develop a strong work ethic, strengthen their leadership skills, and learn how to take personal responsibility for their actions. VYCC Crews work at VT State Parks, U.S. Forest Service Campgrounds, in local communities, and throughout the state's backcountry. The VYCC has also given aid to a similar program in North Carolina, which is currently in its infancy.
The Youth Conservation Corps is a youth conservation program present in federal lands around the country. The program gives youth aged 13-17 the opportunity to participate in conservation projects in a team setting. YCC programs are available in land managed by the National Park Service, the Forest Service, and the Fish and Wildlife Service. Projects can last up to 10 weeks and typically run over the summer. Some YCC programs are residential, meaning the participants are given housing on the land they work on. Projects may necessitate youth to camp in backcountry settings in order to work on trails or campsites. Most require youth to commute daily or house youth for only a few days a week. Youth are typically paid for their work. YCC programs contribute to the maintenance of public lands and instill a value for hard work and the outdoors in those who participate.
Conservation Legacy is a non-profit employment, job training, and education organization with locations across the United States including Arizona Conservation Corps in Tucson and Flagstaff, Arizona; Southwest Conservation Corps in Durango and Salida, Colorado; and Southeast Conservation Corps in Chattanooga, Tennessee. Conservation Legacy also operates an AmeriCorps VISTA team serving to improve the environment and economies of historic mining communities in the American West and Appalachia. Conservation Legacy also hosts the Environmental Stewards Program - providing internships with federal, state, municipal and NGO land management agencies nationwide. Conservation Legacy formed as a merger of the Southwest Youth Corps, San Luis Valley Youth Corps, The Youth Corps of Southern Arizona, and Coconino Rural Environmental Corps.
Conservation Legacy engages young adults ages 14 to 26 and U.S. military veterans of all ages in personal and professional development experiences involving conservation projects on public lands. Corp members live, work, and learn in teams of six to eight for terms of service ranging from 3 months to 1 year.
The Sea Ranger Service is a social enterprise, based in Netherlands, that has taken its inspiration from the Civilian Conservation Corps in running a permanent youth training program, supported by veterans, to manage ocean areas and carry out underwater landscape restoration. Unemployed youths are trained up as Sea Rangers during a bootcamp and subsequently offered full-time employment to manage and regenerate Marine Protected Areas and aid ocean conservation. The Sea Ranger Service works in close cooperation with the Dutch government and national maritime authorities. | https://en.wikipedia.org/wiki?curid=7821 |
Caribbean Sea
The Caribbean Sea (; ; ; ; ; ) is an American Mediterranean Sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico and Central America to the west and south west, to the north by the Greater Antilles starting with Cuba, to the east by the Lesser Antilles, and to the south by the north coast of South America.
The entire area of the Caribbean Sea, the numerous islands of the West Indies, and adjacent coasts, are collectively known as the Caribbean. The Caribbean Sea is one of the largest seas and has an area of about . The sea's deepest point is the Cayman Trough, between the Cayman Islands and Jamaica, at below sea level. The Caribbean coastline has many gulfs and bays: the Gulf of Gonâve, Gulf of Venezuela, Gulf of Darién, Golfo de los Mosquitos, Gulf of Paria and Gulf of Honduras.
The Caribbean Sea has the world's second largest barrier reef, the Mesoamerican Barrier Reef. It runs along the coasts of Mexico, Belize, Guatemala, and Honduras.
The name "Caribbean" derives from the Caribs, one of the region's dominant Native American groups at the time of European contact during the late 15th century. After Christopher Columbus landed in the Bahamas in 1492, the Spanish term "Antillas" applied to the lands; stemming from this, "Sea of the Antilles" became a common alternative name for "Caribbean Sea" in various European languages. During the first century of development, Spanish dominance in the region remained undisputed.
From the 16th century, Europeans visiting the Caribbean region identified the "South Sea" (the Pacific Ocean, to the south of the isthmus of Panama) as opposed to the "North Sea" (the Caribbean Sea, to the north of the same isthmus).
The Caribbean Sea had been unknown to the populations of Eurasia until 1492, when Christopher Columbus sailed into Caribbean waters on a quest to find a sea route to Asia. At that time the Western Hemisphere in general was unknown to most Europeans, although it had been discovered between the years 800 and 1000 by the vikings. Following the discovery of the islands by Columbus, the area was quickly colonized by several Western cultures (initially Spain, then later England, the Dutch Republic, France, Courland and Denmark). Following the colonization of the Caribbean islands, the Caribbean Sea became a busy area for European-based marine trading and transports, and this commerce eventually attracted pirates such as Samuel Bellamy and Blackbeard.
The International Hydrographic Organization defines the limits of the Caribbean Sea as follows:
Note that, although Barbados is an island on the same continental shelf, it is considered to be in the Atlantic Ocean rather than the Caribbean Sea.
The Caribbean Sea is an oceanic sea largely situated on the Caribbean Plate. The Caribbean Sea is separated from the ocean by several island arcs of various ages. The youngest stretches from the Lesser Antilles to the Virgin Islands to the north east of Trinidad and Tobago off the coast of Venezuela. This arc was formed by the collision of the South American Plate with the Caribbean Plate and includes active and extinct volcanoes such as Mount Pelee, the Quill (volcano) on Sint Eustatius in the Caribbean Netherlands and Morne Trois Pitons on Dominica. The larger islands in the northern part of the sea Cuba, Hispaniola, Jamaica and Puerto Rico lie on an older island arc.
The geological age of the Caribbean Sea is estimated to be between 160 and 180 million years and was formed by a horizontal fracture that split the supercontinent called Pangea in the Mesozoic Era. It is assumed the proto-caribbean basin existed in the Devonian period. In the early Carboniferous movement of Gondwana to the north and its convergence with the Euramerica basin decreased in size. The next stage of the Caribbean Sea's formation began in the Triassic. Powerful rifting led to the formation of narrow troughs, stretching from modern Newfoundland to the west coast of the Gulf of Mexico which formed siliciclastic sedimentary rocks. In the early Jurassic due to powerful marine transgression, water broke into the present area of the Gulf of Mexico creating a vast shallow pool. The emergence of deep basins in the Caribbean occurred during the Middle Jurassic rifting. The emergence of these basins marked the beginning of the Atlantic Ocean and contributed to the destruction of Pangaea at the end of the late Jurassic. During the Cretaceous the Caribbean acquired the shape close to that seen today. In the early Paleogene due to Marine regression the Caribbean became separated from the Gulf of Mexico and the Atlantic Ocean by the land of Cuba and Haiti. The Caribbean remained like this for most of the Cenozoic until the Holocene when rising water levels of the oceans restored communication with the Atlantic Ocean.
The Caribbean's floor is composed of sub-oceanic sediments of deep red clay in the deep basins and troughs. On continental slopes and ridges calcareous silts are found. Clay minerals likely having been deposited by the mainland river Orinoco and the Magdalena River. Deposits on the bottom of the Caribbean Sea and Gulf of Mexico have a thickness of about . Upper sedimentary layers relate to the period from the Mesozoic to the Cenozoic (250 million years ago to present) and the lower layers from the Paleozoic to the Mesozoic.
The Caribbean sea floor is divided into five basins separated from each other by underwater ridges and mountain ranges. Atlantic Ocean water enters the Caribbean through the "Anegada Passage" lying between the Lesser Antilles and Virgin Islands and the "Windward Passage" located between Cuba and Haiti. The Yucatán Channel between Mexico and Cuba links the Gulf of Mexico with the Caribbean. The deepest points of the sea lie in Cayman Trough with depths reaching approximately . Despite this, the Caribbean Sea is considered a relatively shallow sea in comparison to other bodies of water.
The pressure of the South American Plate to the east of the Caribbean causes the region of the Lesser Antilles to have high volcanic activity. There was a very serious eruption of Mount Pelée in 1902 which caused many casualties.
The Caribbean sea floor is also home to two oceanic trenches: the Cayman Trench and Puerto Rico Trench, which put the area at a high risk of earthquakes. Underwater earthquakes pose a threat of generating tsunamis which could have a devastating effect on the Caribbean islands. Scientific data reveals that over the last 500 years the area has seen a dozen earthquakes above 7.5 magnitude. Most recently, a 7.1 earthquake struck Haiti on January 12, 2010.
The hydrology of the sea has a high level of homogeneity. Annual variations in monthly average water temperatures at the surface do not exceed . Over the past fifty years the Caribbean has gone through three stages: cooling until 1974; a cold phase with peaks during 1974–1976 and 1984–1986 then; a warming phase with an increase in temperature of per year. Virtually all temperature extremes were associated with the phenomena of El Niño and La Niña. The salinity of seawater is about 3.6% and its density is . The surface water colour is blue-green to green.
The Caribbean's depth in its wider basins and deep water temperatures are similar to those of the Atlantic. Atlantic deep water is thought to spill into the Caribbean and contribute to the general deep water of its sea. The surface water (30 m; 100 feet) acts as an extension of the northern Atlantic as the Guiana Current and part of the North Equatorial Current enter the sea on the east. On the western side of the sea the trade winds influence a northerly current which causes an upwelling and a rich fishery near Yucatán.
The Caribbean is home to about 9% of the world's coral reefs covering about , most of which are located off the Caribbean Islands and the Central American coast. Among them stands out the Belize Barrier Reef with an area of which was declared a World Heritage Site in 1996. It forms part of the Great Mayan Reef also known as the MBRS and being over in length is the world's second longest. It runs along the Caribbean coasts of Mexico, Belize, Guatemala and Honduras.
During the past ten years, unusually warm Caribbean waters have been increasingly threatening Caribbean coral reefs. Coral reefs support some of the most diverse marine habitats in the world, but they are fragile ecosystems. When tropical waters become unusually warm for extended periods of time, microscopic plants called zooxanthellae, which are symbiotic partners living within the coral polyp tissues, die off. These plants provide food for the corals, and give them their color. The result of the death and dispersal of these tiny plants is called coral bleaching, and can lead to the devastation of large areas of reef. Over 42% of corals are completely bleached and 95% are experiencing some type of whitening. Historically the Caribbean is thought to contain 14% of the world's coral reefs.
The habitats supported by the reefs are critical to such tourist activities as fishing and diving, and provide an annual economic value to Caribbean nations of US$3.1–4.6 billion. Continued destruction of the reefs could severely damage the region's economy. A "Protocol of the Convention for the Protection and Development of the Marine Environment of the Wider Caribbean Region" came in effect in 1986 to protect the various endangered marine life of the Caribbean through forbidding human activities that would advance the continued destruction of such marine life in various areas. Currently this protocol has been ratified by 15 countries. Also, several charitable organisations have been formed to preserve the Caribbean marine life, such as "Caribbean Conservation Corporation" which seeks to study and protect sea turtles while educating others about them.
In connection with the foregoing, the Institute of Marine Sciences and Limnology of the National Autonomous University of Mexico, conducted a regional study, funded by the Department of Technical Cooperation of the International Atomic Energy Agency, in which specialists from 11 Latin American countries (Colombia, Costa Rica, Cuba, Guatemala, Haiti, Honduras, Mexico, Nicaragua, Panama, Dominican Republic, Venezuela plus Jamaica) participated. The findings indicate that heavy metals such as mercury, arsenic, and lead, have been identified in the coastal zone of the Caribbean Sea. Analysis of toxic metals and hydrocarbons is based on the investigation of coastal sediments that have accumulated less than 50 meters deep during the last hundred and fifty years. The project results were presented in Vienna in the forum "Water Matters", and the 2011 General Conference of said multilateral organization.
The climate of the Caribbean is driven by the low latitude and tropical ocean currents that run through it. The principal ocean current is the North Equatorial Current, which enters the region from the tropical Atlantic. The climate of the area is tropical, varying from tropical rainforest in some areas to tropical savanna in others. There are also some locations that are arid climates with considerable drought in some years.
Rainfall varies with elevation, size and water currents (cool upwelling keep the ABC islands arid). Warm, moist trade winds blow consistently from the east, creating both rain forest and semi arid climates across the region. The tropical rainforest climates include lowland areas near the Caribbean Sea from Costa Rica north to Belize, as well as the Dominican Republic and Puerto Rico, while the more seasonal dry tropical savanna climates are found in Cuba, northern Venezuela, and southern Yucatán, Mexico. Arid climates are found along the extreme southern coast of Venezuela out to the islands including Aruba and Curaçao, as well as the northern tip of Yucatán
Tropical cyclones are a threat to the nations that rim the Caribbean Sea. While landfalls are infrequent, the resulting loss of life and property damage makes them significant hazard to life in the Caribbean. Tropical cyclones that impact the Caribbean often develop off the West coast of Africa and make their way west across the Atlantic Ocean toward the Caribbean, while other storms develop in the Caribbean itself. The Caribbean hurricane season as a whole lasts from June through November, with the majority of hurricanes occurring during August and September. On average around 9 tropical storms form each year, with 5 reaching hurricane strength. According to the National Hurricane Center 385 hurricanes occurred in the Caribbean between 1494 and 1900.
The region has a high level of biodiversity and many species are endemic to the Caribbean.
The vegetation of the region is mostly tropical but differences in topography, soil and climatic conditions increase species diversity. Where there are porous limestone terraced islands these are generally poor in nutrients. It is estimated that 13,000 species of plants grow in the Caribbean of which 6,500 are endemic. For example, guaiac wood ("Guaiacum officinale"), the flower of which is the national flower of Jamaica and the Bayahibe rose ("Pereskia quisqueyana") which is the national flower of the Dominican Republic and the ceiba which is the national tree of both Puerto Rico and Guatemala. The mahogany is the national tree of the Dominican Republic and Belize. The caimito ("Chrysophyllum cainito") grows throughout the Caribbean. In coastal zones there are coconut palms and in lagoons and estuaries are found thick areas of black mangrove and red mangrove ("Rhizophora mangle").
In shallow water flora and fauna is concentrated around coral reefs where there is little variation in water temperature, purity and salinity. Leeward side of lagoons provide areas of growth for sea grasses. Turtle grass ("Thalassia testudinum") is common in the Caribbean as is manatee grass ("Syringodium filiforme") which can grow together as well as in fields of single species at depths up to . Another type shoal grass ("Halodule wrightii") grows on sand and mud surfaces at depths of up to . In brackish water of harbours and estuaries at depths less than widgeongrass ("Ruppia maritima") grows. Representatives of three species belonging to the genus "Halophila", ("Halophila baillonii", "Halophila engelmannii" and "Halophila decipiens") are found at depths of up to except for "Halophila engelmani" which does not grow below and is confined to the Bahamas, Florida, the Greater Antilles and the western part of the Caribbean. "Halophila baillonii" has been found only in the Lesser Antilles.
Marine biota in the region have representatives of both the Indian and Pacific oceans which were caught in the Caribbean before the emergence of the Isthmus of Panama four million years ago. In the Caribbean Sea there are around 1,000 documented species of fish, including sharks (bull shark, tiger shark, silky shark and Caribbean reef shark), flying fish, giant oceanic manta ray, angel fish, spotfin butterflyfish, parrotfish, Atlantic Goliath grouper, tarpon and moray eels. Throughout the Caribbean there is industrial catching of lobster and sardines (off the coast of Yucatán Peninsula).
There are 90 species of mammals in the Caribbean including sperm whales, humpback whales and dolphins. The island of Jamaica is home to seals and manatees. The Caribbean monk seal which lived in the Caribbean is considered extinct. The solenodon is endangered.
There are 500 species of reptiles (94% of which are endemic). Islands are inhabited by some endemic species such as rock iguanas and American crocodile. The blue iguana, endemic to the island of Grand Cayman, is endangered. The green iguana is invasive to Grand Cayman. The Mona ground iguana which inhabits the island of Mona, Puerto Rico, is endangered. The rhinoceros iguana from the island of Hispaniola which is shared between Haiti and the Dominican Republic is also endangered. The region has several types of sea turtle (loggerhead, green turtle, hawksbill, leatherback turtle, Atlantic ridley and olive ridley). Some species are threatened with extinction. Their populations have been greatly reduced since the 17th century – the number of green turtles has declined from 91 million to 300,000 and hawksbill turtles from 11 million to less than 30,000 by 2006.
All 170 species of amphibians that live in the region are endemic. The habitats of almost all members of the toad family, poison dart frogs, tree frogs and leptodactylidae (a type of frog) are limited to only one island. The Golden coqui is in serious threat of extinction.
In the Caribbean 600 species of birds have been recorded of which 163 are endemic such as the tody, Fernandina's flicker and palmchat. The American yellow warbler is found in many areas as is the green heron. Of the endemic species 48 are threatened with extinction including the Puerto Rican amazon, yellow-breasted crake and the Zapata wren. According to Birdlife International in 2006 in Cuba 29 species of bird are in danger of extinction and two species officially extinct. The black-fronted piping guan is endangered as is the plain pigeon. The Antilles along with Central America lie in the flight path of migrating birds from North America so the size of populations is subject to seasonal fluctuations. In the forests are found parrots, bananaquit and toucans. Over the open sea can be seen frigatebirds and tropicbirds.
The Caribbean region has seen a significant increase in human activity since the colonization period. The sea is one of the largest oil production areas in the world, producing approximately 170 million per year. The area also generates a large fishing industry for the surrounding countries, accounting for of fish a year.
Human activity in the area also accounts for a significant amount of pollution, The Pan American Health Organization estimated in 1993 that only about 10% of the sewage from the Central American and Caribbean Island countries is properly treated before being released into the sea.
The Caribbean region supports a large tourism industry. The Caribbean Tourism Organization calculates that about 12 million people a year visit the area, including (in 1991–1992) about 8 million cruise ship tourists. Tourism based upon scuba diving and snorkeling on coral reefs of many Caribbean islands makes a major contribution to their economies. | https://en.wikipedia.org/wiki?curid=7822 |
Colin Maclaurin
Colin Maclaurin (; ; February 1698 – 14 June 1746) was a Scottish mathematician who made important contributions to geometry and algebra. He is also known for being a child prodigy and holding the record for being the youngest professor. The Maclaurin series, a special case of the Taylor series, is named after him.
Owing to changes in orthography since that time (his name was originally rendered as “M‘Laurine”), his surname is alternatively written MacLaurin.
Maclaurin was born in Kilmodan, Argyll. His father, Reverend and Minister of Glendaruel John Maclaurin, died when Maclaurin was in infancy, and his mother died before he reached nine years of age. He was then educated under the care of his uncle, the Reverend Daniel Maclaurin, minister of Kilfinan. A child prodigy, he entered university at age 11.
At eleven, Maclaurin, a child prodigy at the time entered the University of Glasgow. He graduated MA three years later by defending a thesis on "the Power of Gravity," and remained at Glasgow to study divinity until he was 19, when he was elected professor of mathematics in a ten-day competition at the Marischal College in the University of Aberdeen. This record as the world's youngest professor endured until March 2008, when the record was officially given to Alia Sabur.
In the vacations of 1719 and 1721, Maclaurin went to London, where he became acquainted with Sir Isaac Newton, Dr Benjamin Hoadly, Samuel Clarke, Martin Folkes, and other philosophers. He was admitted a member of the Royal Society.
In 1722, having provided a locum for his class at Aberdeen, he travelled on the Continent as tutor to George Hume, the son of Alexander Hume, 2nd Earl of Marchmont. During their time in Lorraine, he wrote his essay on the percussion of bodies ("Demonstration des loix du choc des corps"), which gained the prize of the Royal Academy of Sciences in 1724. Upon the death of his pupil at Montpellier, Maclaurin returned to Aberdeen.
In 1725, Maclaurin was appointed deputy to the mathematical professor at Edinburgh, James Gregory (brother of David Gregory and nephew of the esteemed James Gregory), upon the recommendation of Isaac Newton. On 3 November of that year Maclaurin succeeded Gregory, and went on to raise the character of that university as a school of science. Newton was so impressed with Maclaurin that he had offered to pay his salary himself.
Maclaurin used Taylor series to characterize maxima, minima, and points of inflection for infinitely differentiable functions in his "Treatise of Fluxions". Maclaurin attributed the series to Brook Taylor, though the series was known before to Newton and Gregory, and in special cases to Madhava of Sangamagrama in fourteenth century India.
Nevertheless, Maclaurin received credit for his use of the series, and the Taylor series expanded around 0 is sometimes known as the "Maclaurin series".
Maclaurin also made significant contributions to the gravitation attraction of ellipsoids, a subject that furthermore attracted the attention of d'Alembert, A.-C. Clairaut, Euler, Laplace, Legendre, Poisson and Gauss. Maclaurin showed that an oblate spheroid was a possible equilibrium in Newton's theory of gravity. The subject continues to be of scientific interest, and Nobel Laureate Subramanyan Chandrasekhar dedicated a chapter of his book "Ellipsoidal Figures of Equilibrium" to Maclaurin spheroids.
Independently from Euler and using the same methods, Maclaurin discovered the Euler–Maclaurin formula. He used it to sum powers of arithmetic progressions, derive Stirling's formula, and to derive the Newton-Cotes numerical integration formulas which includes Simpson's rule as a special case.
Maclaurin contributed to the study of elliptic integrals, reducing many intractable integrals to problems of finding arcs for hyperbolas. His work was continued by d'Alembert and Euler, who gave a more concise approach.
In his "Treatise of Algebra" (Ch. XII, Sect 86), published in 1748 two years after his death, Maclaurin proved a rule for solving square linear systems in the cases of 2 and 3 unknowns, and discussed the case of 4 unknowns. This publication preceded by two years Cramer's publication of a generalization of the rule to "n" unknowns, now commonly known as Cramer's rule.
In 1733, Maclaurin married Anne Stewart, the daughter of Walter Stewart, the Solicitor General for Scotland, by whom he had seven children. His eldest son John Maclaurin studied Law, was a Senator of the College of Justice, and became Lord Dreghorn; he was also joint founder of the Royal Society of Edinburgh.
Maclaurin actively opposed the Jacobite rising of 1745 and superintended the operations necessary for the defence of Edinburgh against the Highland army. Maclaurin compiled a diary of his exertions against the Jacobites, both within and without the city. When the Highland army entered the city, however, he fled to York, where he was invited to stay by the Archbishop of York.
On his journey south, Maclaurin fell from his horse, and the fatigue, anxiety, and cold to which he was exposed on that occasion laid the foundations of dropsy. He returned to Edinburgh after the Jacobite army marched south, but died soon after his return.
He is buried at Greyfriars Kirkyard, Edinburgh. The simple table stone is inscribed simply "C. M. Nat MDCXCVIII Ob MDCCXLVI" and stands close to the south-west corner of the church but is supplemented by a more wordy memorial on the outer wall of the church.
Mathematician and former MIT President Richard Cockburn Maclaurin was from the same family.
The Maclaurin Society (MacSoc), the Mathematics and Statistics Society at Glasgow University, is named in his honour.
Colin MacLaurin Road within Edinburgh University's King's Buildings complex is named in his honour.
Some of his important works are:
Colin Maclaurin was the name used for the new Mathematics and Actuarial Mathematics and Statistics Building at Heriot-Watt University, Edinburgh. | https://en.wikipedia.org/wiki?curid=7824 |
Covenant-breaker
Covenant-breaker is a term used by Baháʼís to refer to a person who has been excommunicated from the Baháʼí community for the act of covenant-breaking, roughly defined as active opposition to the Baháʼí Faith from a current member. According to Baháʼí law, only the head of the religion, currently the Universal House of Justice, has the authority to declare a person a covenant-breaker.
A person may be declared a covenant-breaker for actions which are seen as challenging the unity of the Baháʼí community, not for personal matters such as failure to obey Baháʼí law or conversion to another religion. When a person is a declared a covenant-breaker, all Baháʼís are expected to avoid unnecessary association with that person.
Covenant-breaking does not refer to attacks from non-Baháʼís or former Baha'is. Rather, it is in reference to internal campaigns of opposition where the Covenant-breaker is seen as challenging the unity of the Baháʼí Faith, causing internal division, or by claiming or supporting an alternate succession of authority or administrative structure. The central purpose of the covenant is to prevent schism and dissension.
In a letter to an individual dated 23 March 1975, the Universal House of Justice wrote:
The term 'Covenant-breaker' or, in Arabic 'naqid al-mithaq' [pl. Naqidu 'l-mithaq], was first used by ʻAbdu'l-Bahá to describe the partisans of his brother Mírzá Muhammad ʻAlí, who challenged his leadership. In ʻAbdu'l-Bahá's Will and Testament, He appointed Shoghi Effendi as the "Guardian" of the religion and called for the eventual election of the Universal House of Justice, and defined in the same manner opposition to these two institutions as Covenant-Breaking. ʻAbdu'l-Bahá advised all Baháʼís to shun anyone opposing the Covenant: "...one of the greatest and most fundamental principles of the Cause of God is to shun and avoid entirely the Covenant-breakers, for they will utterly destroy the Cause of God, exterminate His Law and render of no account all efforts exerted in the past."
Most Covenant-breakers are involved in schismatic groups, but not always. For example, a Baháʼí who refuses to follow guidance on treatment of Covenant-breakers is at risk of being named one. One article originally written for the Baháʼí Encyclopedia, characterized Covenant-breakers that have emerged in the course of Baháʼí history as belonging to one of four categories:
Shoghi Effendi wrote to the National Spiritual Assembly of Canada in 1957:
Beyond this, many other relationships to the Baháʼí Faith exist, both positive and negative. Covenant-breaking does not apply to most of them. The following is a partial list of those who could not rightly be termed Covenant-breakers:
Bábís are generally regarded as another religion altogether. Since Covenant-breaking presumes that one has submitted oneself to a covenant and then broken it, and Bábís never recognized or swore allegiance to Baháʼu'lláh, they are not Covenant-breakers.
Followers of Subh-i-Azal, Baháʼu'lláh's half-brother who tried to poison him, engaged in active opposition to Baháʼís, and Shoghi Effendi did inform Baháʼís that they should avoid contact with his descendants, writing that "No intelligent and loyal Baha'i would associate with a descendant of Azal, if he traced the slightest breath of criticism of our Faith, in any aspect, from that person. In fact these people should be strenuously avoided as having an inherited spiritual disease -- the disease of Covenant-breaking!".
Through the influence of Bahiyyih Khanum, the eldest daughter of Baháʼu'lláh, everyone in the household initially rallied around Shoghi Effendi after the death of ʻAbdu'l-Bahá. For several years his brother Husayn and several cousins served him as secretaries. The only ones publicly opposing him were Mírzá Muhammad ʻAlí and his followers, who were declared Covenant-breakers by ʻAbdu'l-Bahá. Contrary to ʻAbdu'l-Bahá's specific instruction, certain family members established illicit links with those whom ʻAbdu'l-Bahá had declared Covenant-breakers. After Bahiyyih Khanum died in 1932, Shoghi Effendi's eldest sister – Ruhangiz – married Nayyer Effendi Afnan, a son of Siyyid Ali Afnan, the son of the Báb's brother in law. Nayyers' brother Hussein Effendi Afnan had been expelled for failing to resign from the government of Iraq in protest for the seizure of the house of Baháʼu'lláh. Through Ruhangiz's efforts, Shoghi Effendi's other sister and his cousin Thurayya also married sons of Siyyid Ali Afnan. Presumably being faced with a choice between shunning their disobedient family members and being themselves disobedient to ʻAbdu'l-Bahá and Shoghi Effendi, his cousins, aunts and uncles chose the latter.
After years of silence on these developments, cables sent by Shoghi Effendi on 2 November 1941 provide background to developments among family members. Ruhi Afnan, Shoghi Effendi's cousin through ʻAbdu'l-Bahá's daughter Tuba:
Faydi was the son of Furughiyyih Khanum, a daughter of Baháʼu'lláh by his third wife Gawhar. Furughiyyih and her children all supported Mírzá Muhammad ʻAlí. Faydi had two elder brothers. Hussein Effendi Afnan was aide-de-camp to Faisal II of Iraq and Nayyer Effendi Afnan was Commissioner of Parks in Cairo, Egypt. The entire Baháʼí Family was stigmatized by Shoghi Effendi as Covenant-breakers as he was displeased with their marriages.
Then in a 1950 cable:
And in 1953:
Later, Ruhi was presented with a copy of Sohrab's book about his excommunication:
Concerning Munib Shahid, Shoghi Effendi's cousin through ʻAbdu'l-Bahá's daughter Ruha, Shoghi Effendi sent the following cable to the Baháʼí world in November 1944:
Husayn Ali was Shoghi Effendi's brother. In April 1945, Shoghi Effendi sent the following cable to the Baháʼí world: "My faithless brother Husayn, after long period of dishonourable conduct, has abandoned the Master's home to consort with his sister and other Covenant-breakers" ("Baháʼí News", No. 174, p. 2). In March 1950, Shoghi Effendi would send a further cable: "Faithless brother Hussein, already abased through dishonorable conduct over period (of) years followed by association with Covenant-breakers (in) Holy Land and efforts (to) undermine Guardian's position, recently further demeaned himself through marriage under obscure circumstances with lowborn Christian girl (in) Europe" ("Baháʼí News", No. 229, p. 1). Shoghi Effendi would later clarify the use of the term "lowborn Christian girl" as follows: "Regarding his cable concerning Hussein: he has been very surprised to note that the terms “low-born Christian girl” and “disgraceful alliance” should arouse any question: it seems to him that the friends should realize it is not befitting for the Guardian's own brother, the grandchild of the Master, an Afnán and Aghsán mentioned in the Will and Testament of the Master, and of whom so much was expected because of his relation to the family of the Prophet, to marry an unknown girl, according to goodness knows what rite, who is not a believer at all. Surely, every Bahá’í must realise that the terms low-born and Christian are definitions of a situation and in no way imply any condemnation of a person’s birth or the religion they belong to as such. We have no snobbery and no religious prejudice in our Faith. But the members of the Master’s family have contracted marriages which cannot be considered in any other light than disgraceful, in view of what ‘Abdu’l-Bahá wished for them.” ("Baháʼí News", No. 236, p. 4)("Unfolding Destiny", p. 248).
Concerning his own brother Riaz, the following cable was sent in December 1951:
He dispatched a cable concerning his younger sister in December 1941:
The reason for her being declared a Covenant-breaker was that she followed the example of Ruhi's sister by marrying to one of his cousins without the Guardian's consent. Mehrangiz married to Hassan Afnan, the son of Furughiyyih Khanum, a daughter of Baháʼu'lláh by his third wife Gawhar.
Most of the groups regarded by the larger group of Baháʼís as Covenant-breakers originated in the claims of Charles Mason Remey to the Guardianship in 1960. The Will and Testament of ʻAbdu'l-Bahá states that Guardians should be lineal descendants of Baháʼu'lláh, that each Guardian must select his successor during his lifetime, and that the nine Hands of the Cause of God permanently stationed in the holy land must approve the appointment by majority vote. Baháʼís interpret lineal descendency to mean physical familial relation to Baháʼu'lláh, of which Mason Remey was not.
Almost all of Baháʼís accepted the determination of the Hands of the Cause that upon the death of Shoghi Effendi, he died "without having appointed his successor". There was an absence of a valid descendant of Baháʼu'lláh who could qualify under the terms of ʻAbdu'l-Bahá's will. Later the Universal House of Justice, initially elected in 1963, made a ruling on the subject that it was not possible for another Guardian to be appointed.
In 1960 Remey, a Hand of the Cause himself, retracted his earlier position, and claimed to have been coerced. He claimed to be the successor to Shoghi Effendi. He and the small number of people who followed him were expelled from the Faith by the Hands of the Cause. Those close to Remey claimed that he went senile in old age, and by the time of his death he was largely abandoned, with his most prominent followers fighting amongst themselves for leadership.
The largest group of the remaining followers of Remey, members of the so called "Orthodox Baháʼí Faith", believe that legitimate authority passed from Shoghi Effendi to Mason Remey to Joel Marangella. They, therefore, regard the Universal House of Justice in Haifa, Israel to be illegitimate, and its members and followers to be Covenant-breakers.
The present descendants of expelled members of Baháʼu'lláh's family have not specifically been declared Covenant-breakers, though they mostly do not associate themselves with the Baháʼí religion.
A small group of Baháʼís in Northern New Mexico believe that these descendants are eligible for appointment to the Guardianship and are waiting for such a direct descendant of Baháʼu'lláh to arise as the rightful Guardian.
There is also a small group in Montana, originally inspired by Leland Jensen, who claimed a status higher than that of the Guardian. His failed apocalyptic predictions and unsuccessful efforts to reestablish the Guardianship and the administration were apparent by his death in 1996. A dispute among Jensen's followers over the identity of the Guardian resulted in another division in 2001. | https://en.wikipedia.org/wiki?curid=7827 |
Chaos Computer Club
The Chaos Computer Club (CCC) is Europe's largest association of hackers with registered members. It is incorporated as an "eingetragener Verein" in Germany, with local chapters (called ") in various cities in Germany and other German-speaking countries.
Since 1985, some chapters in Switzerland have organized an independent sister association called the (CCC-CH) instead.
The CCC describes itself as "a galactic community of life forms, independent of age, sex, race or societal orientation, which strives across borders for freedom of information…". In general, the CCC advocates more transparency in government, freedom of information, and the human right to communication. Supporting the principles of the hacker ethic, the club also fights for free universal access to computers and technological infrastructure as well as the use of open-source software. The CCC spreads an entrepreneurial vision refusing capitalist control. It has been characterised as "…one of the most influential digital organisations anywhere, the centre of German digital culture, hacker culture, hacktivism, and the intersection of any discussion of democratic and digital rights".
Members of the CCC have demonstrated and publicized a number of important information security problems.
The CCC frequently criticizes new legislation and products with weak information security which endanger citizen rights or the privacy of users.
Notable members of the CCC regularly function as expert witnesses for the German constitutional court, organize lawsuits and campaigns, or otherwise influence the political process.
The CCC hosts the annual Chaos Communication Congress, Europe's biggest hacker gathering.
When the event was held in the Hamburg congress center in 2013, it drew guests.
For the 2016 installment, guests were expected, with additional viewers following the event via live streaming.
Every four years, the Chaos Communication Camp is the outdoor alternative for hackers worldwide.
The CCC also held, from 2009 to 2013, a yearly conference called SIGINT in Cologne which focused on the impact of digitisation on society. The SIGINT conference was discontinued in 2014.
The four-day conference "" in Karlsruhe is with more than 1500 participants the second largest annual event.
Another yearly CCC event taking place on the Easter weekend is the Easterhegg, which is more workshop oriented than the other events.
The CCC often uses the c-base station located in Berlin as an event location or as function rooms.
The CCC publishes the irregular magazine "Datenschleuder" ("data slingshot") since 1984.
The Berlin chapter produces a monthly radio show called which picks up various technical and political topics in a two-hour talk radio show. The program is aired on a local radio station called and on the internet.
Other programs have emerged in the context of Chaosradio, including radio programs offered by some regional Chaos Groups and the podcast spin-off "CRE" by Tim Pritlove.
Many of the chapters of CCC participate in the volunteer project "Chaos macht Schule" which supports teaching in local schools. Its aims are to improve technology and media literacy of pupils, parents, and teachers.
CCC members are present in big tech companies and in administrative instances. One of the spokespersons of the CCC, as of 1986, Andy Müller-Maguhn, was a member of the executive committee of the ICANN (Internet Corporation for Assigned Names and Numbers) between 2000 and 2002.
The CCC sensitises and introduces people to the questions of data privacy. Some of its local chapters support or organize so called CryptoParties to introduce people to the basics of practical cryptography and internet anonymity.
The CCC was founded in Berlin on 12 September 1981 at a table which had previously belonged to the Kommune 1 in the rooms of the newspaper Die Tageszeitung by Wau Holland and others in anticipation of the prominent role that information technology would play in the way people live and communicate.
The CCC became world-famous in 1984 when they drew public attention to the security flaws of the German Bildschirmtext computer network by causing it to debit DM in a Hamburg bank in favor of the club. The money was returned the next day in front of the press. Prior to the incident, the system provider had failed to react to proof of the security flaw provided by the CCC, claiming to the public that their system was safe. Bildschirmtext was the biggest commercially available online system targeted at the general public in its region at that time, run and heavily advertised by the German telecommunications agency Deutsche Bundespost which also strove to keep up-to-date alternatives out of the market.
In 1987, the CCC was peripherally involved in the first cyberespionage case to make international headlines. A group of German hackers led by Karl Koch, who was loosely affiliated with the CCC, was arrested for breaking into US government and corporate computers, and then selling operating-system source code to the Soviet KGB.
This incident was portrayed in the movie "23".
In April 1998, the CCC successfully demonstrated the cloning of a GSM customer card, breaking the COMP128 encryption algorithm used at that time by many GSM SIMs.
In 2001, the CCC celebrated its twentieth birthday with an interactive light installation dubbed "Project Blinkenlights" that turned the building Haus des Lehrers in Berlin into a giant computer screen. A follow up installation, "Arcade", at the Bibliothèque nationale de France was the world's biggest light installation.
Later in October 2008, CCC's Project Blinkenlights went to Toronto, Ontario, Canada with project Stereoscope.
In March 2008, the CCC acquired and published the fingerprints of German Minister of the Interior Wolfgang Schäuble. The magazine also included the fingerprint on a film that readers could use to fool fingerprint readers. This was done to protest the use of biometric data in German identity devices such as e-passports.
The Staatstrojaner ("Federal Trojan horse") is a computer surveillance program installed secretly on a suspect's computer, which the German police uses to wiretap Internet telephony. This "source wiretapping" is the only feasible way to wiretap in this case, since Internet telephony programs will usually encrypt the data when it leaves the computer. The Federal Constitutional Court of Germany has ruled that the police may only use such programs for telephony wiretapping, and for no other purpose, and that this restriction should be enforced through technical and legal means.
On 8 October 2011, the CCC published an analysis of the Staatstrojaner software. The software was found to have the ability to remote control the target computer, to capture screenshots, and to fetch and run arbitrary extra code. The CCC says that having this functionality built in is in direct contradiction to the ruling of the constitutional court.
In addition, there were a number of security problems with the implementation. The software was controllable over the Internet, but the commands were sent completely unencrypted, with no checks for authentication or integrity. This leaves any computer under surveillance using this software vulnerable to attack. The captured screenshots and audio files were encrypted, but so incompetently that the encryption was ineffective. All captured data was sent over a proxy server in the United States, which is problematic since the data is then temporarily outside the German jurisdiction.
The CCC's findings were widely reported in the German press. This trojan has also been nicknamed R2-D2 because the string "C3PO-r2d2-POE" was found in its code; another alias for it is 0zapftis ("It's tapped!" in Bavarian, a sardonic reference to Oktoberfest). According to a Sophos analysis, the trojan's behavior matches that described in a confidential memo between the German Landeskriminalamt and a software firm called ""; the memo was leaked on WikiLeaks in 2008. Among other correlations is the dropper's file name scuinst.exe, short for Skype Capture Unit Installer. The 64-bit Windows version installs a digitally signed driver, but signed by the non-existing certificate authority "Goose Cert". DigiTask later admitted selling spy software to governments.
The Federal Ministry of the Interior released a statement in which they denied that R2-D2 has been used by the Federal Criminal Police Office (BKA); this statement however does not eliminate the possibility that it has been used by state-level German police forces. The BKA had previously announced however (in 2007) that they had somewhat similar trojan software that can inspect a computer's hard drive.
Former WikiLeaks spokesman Daniel Domscheit-Berg was expelled from the national CCC (but not the Berlin chapter) in August 2011. This decision was revoked on February 2012.
As a result of his role in the expulsion, board member Andy Müller-Maguhn was not reelected for another term.
The CCC has repeatedly warned phone users of the weakness of biometric identification in the wake of the 2008 Schäuble fingerprints affair. In their "hacker ethics" the CCC includes "protect people data", but also "Computers can change your life for the better". The club regards privacy as an individual right: the CCC does not discourage people from sharing or storing personal information on their phones, but advocates better privacy protection, and the use of specific browsing and sharing techniques by users.
From a photograph of the user's fingerprint on a glass surface, using "easy everyday means", the biometrics hacking team of the CCC, was able to unlock an iPhone 5S.
The Samsung Galaxy S8's iris recognition system claims to be "one of the safest ways to keep your phone locked and the contents private" as "patterns in your irises are unique to you and are virtually impossible to replicate", as quoted in official Samsung content. However, in some cases, using a high resolution photograph of the phone owner's iris and a lens, the CCC claimed to be able to trick the authentification system.
The Chaos Computer Club France (CCCF) was a fake hacker organisation created in 1989 in Lyon (France) by Jean-Bernard Condat, under the command of Jean-Luc Delacour, an agent of the Direction de la surveillance du territoire governmental agency. The primary goal of the CCCF was to watch and to gather information about the French hacker community, identifying the hackers who could harm the country. Journalist said that this organization also worked with the French National Gendarmerie.
The CCCF had an electronic magazine called "Chaos Digest (ChaosD)". Between 4 January 1993 and 5 August 1993, seventy-three issues were published (). | https://en.wikipedia.org/wiki?curid=7829 |
Complete metric space
In mathematical analysis, a metric space "M" is called complete (or a Cauchy space) if every Cauchy sequence of points in "M" has a limit that is also in "M" or, alternatively, if every Cauchy sequence in "M" converges in "M".
Intuitively, a space is complete if there are no "points missing" from it (inside or at the boundary). For instance, the set of rational numbers is not complete, because e.g. formula_1 is "missing" from it, even though one can construct a Cauchy sequence of rational numbers that converges to it (see further examples below). It is always possible to "fill all the holes", leading to the "completion" of a given space, as explained below.
The space Q of rational numbers, with the standard metric given by the absolute value of the difference, is not complete. Consider for instance the sequence defined by formula_2 and formula_3 This is a Cauchy sequence of rational numbers, but it does not converge towards any rational limit: If the sequence did have a limit "x", then by solving formula_4 necessarily "x"2 = 2, yet no rational number has this property. However, considered as a sequence of real numbers, it does converge to the irrational number formula_1.
The open interval , again with the absolute value metric, is not complete either. The sequence defined by "x""n" = is Cauchy, but does not have a limit in the given space. However the closed interval is complete; for example the given sequence does have a limit in this interval and the limit is zero.
The space R of real numbers and the space C of complex numbers (with the metric given by the absolute value) are complete, and so is Euclidean space R"n", with the usual distance metric. In contrast, infinite-dimensional normed vector spaces may or may not be complete; those that are complete are Banach spaces. The space C of continuous real-valued functions on a closed and bounded interval is a Banach space, and so a complete metric space, with respect to the supremum norm. However, the supremum norm does not give a norm on the space C of continuous functions on , for it may contain unbounded functions. Instead, with the topology of compact convergence, C can be given the structure of a Fréchet space: a locally convex topological vector space whose topology can be induced by a complete translation-invariant metric.
The space Q"p" of "p"-adic numbers is complete for any prime number "p". This space completes Q with the "p"-adic metric in the same way that R completes Q with the usual metric.
If "S" is an arbitrary set, then the set "S"N of all sequences in "S" becomes a complete metric space if we define the distance between the sequences ("x""n") and ("y""n") to be , where "N" is the smallest index for which "x""N" is distinct from "y""N", or 0 if there is no such index. This space is homeomorphic to the product of a countable number of copies of the discrete space "S".
A metric space "X" is complete if and only if every decreasing sequence of non-empty closed subsets of "X", with diameters tending to 0, has a non-empty intersection: if "F""n" is closed and non-empty, for every "n", and , then there is a point common to all sets "F""n".
Every compact metric space is complete, though complete spaces need not be compact. In fact, a metric space is compact if and only if it is complete and totally bounded. This is a generalization of the Heine–Borel theorem, which states that any closed and bounded subspace "S" of R"n" is compact and therefore complete.
Let be a complete metric space. If is a closed set, then "A" is also complete. Let be a metric space. If is a complete subspace, then "A" is also closed.
If "X" is a set and "M" is a complete metric space, then the set of all bounded functions "f" from "X" to "M" is a complete metric space. Here we define the distance in in terms of the distance in "M" with the supremum norm
If "X" is a topological space and "M" is a complete metric space, then the set "C"b("X", "M") consisting of all continuous bounded functions "f" from "X" to "M" is a closed subspace of and hence also complete.
The Baire category theorem says that every complete metric space is a Baire space. That is, the union of countably many nowhere dense subsets of the space has empty interior.
The Banach fixed point theorem states that a contraction mapping on a complete metric space admits a fixed point. The fixed point theorem is often used to prove the inverse function theorem on complete metric spaces such as Banach spaces.
The expansion constant of a metric space is the infimum of all constants formula_7 such that whenever the family formula_8 intersects pairwise, the intersection
is nonempty. A metric space is complete if and only if its expansion constant is ≤ 2.
For any metric space "M", one can construct a complete metric space "M′" (which is also denoted as ), which contains "M" as a dense subspace. It has the following universal property: if "N" is any complete metric space and "f" is any uniformly continuous function from "M" to "N", then there exists a unique uniformly continuous function "f′" from "M′" to "N" that extends "f". The space "M"' is determined up to isometry by this property (among all complete metric spaces isometrically containing "M"), and is called the "completion" of "M".
The completion of "M" can be constructed as a set of equivalence classes of Cauchy sequences in "M". For any two Cauchy sequences "x" = ("x""n") and "y" = ("y""n") in "M", we may define their distance as
(This limit exists because the real numbers are complete.) This is only a pseudometric, not yet a metric, since two different Cauchy sequences may have the distance 0. But "having distance 0" is an equivalence relation on the set of all Cauchy sequences, and the set of equivalence classes is a metric space, the completion of "M". The original space is embedded in this space via the identification of an element "x" of "M"' with the equivalence class of sequences in "M" converging to "x" (i.e., the equivalence class containing the sequence with constant value "x"). This defines an isometry onto a dense subspace, as required. Notice, however, that this construction makes explicit use of the completeness of the real numbers, so completion of the rational numbers needs a slightly different treatment.
Cantor's construction of the real numbers is similar to the above construction; the real numbers are the completion of the rational numbers using the ordinary absolute value to measure distances. The additional subtlety to contend with is that it is not logically permissible to use the completeness of the real numbers in their own construction. Nevertheless, equivalence classes of Cauchy sequences are defined as above, and the set of equivalence classes is easily shown to be a field that has the rational numbers as a subfield. This field is complete, admits a natural total ordering, and is the unique totally ordered complete field (up to isomorphism). It is "defined" as the field of real numbers (see also Construction of the real numbers for more details). One way to visualize this identification with the real numbers as usually viewed is that the equivalence class consisting of those Cauchy sequences of rational numbers that "ought" to have a given real limit is identified with that real number. The truncations of the decimal expansion give just one choice of Cauchy sequence in the relevant equivalence class.
For a prime "p", the "p"-adic numbers arise by completing the rational numbers with respect to a different metric.
If the earlier completion procedure is applied to a normed vector space, the result is a Banach space containing the original space as a dense subspace, and if it is applied to an inner product space, the result is a Hilbert space containing the original space as a dense subspace.
Note that completeness is a property of the "metric" and not of the "topology", meaning that a complete metric space can be homeomorphic to a non-complete one. An example is given by the real numbers, which are complete but homeomorphic to the open interval , which is not complete.
In topology one considers "completely metrizable spaces", spaces for which there exists at least one complete metric inducing the given topology. Completely metrizable spaces can be characterized as those spaces that can be written as an intersection of countably many open subsets of some complete metric space. Since the conclusion of the Baire category theorem is purely topological, it applies to these spaces as well.
Completely metrizable spaces are often called "topologically complete". However, the latter term is somewhat arbitrary since metric is not the most general structure on a topological space for which one can talk about completeness (see the section Alternatives and generalizations). Indeed, some authors use the term "topologically complete" for a wider class of topological spaces, the completely uniformizable spaces.
A topological space homeomorphic to a separable complete metric space is called a Polish space.
Since Cauchy sequences can also be defined in general topological groups, an alternative to relying on a metric structure for defining completeness and constructing the completion of a space is to use a group structure. This is most often seen in the context of topological vector spaces, but requires only the existence of a continuous "subtraction" operation. In this setting, the distance between two points "x" and "y" is gauged not by a real number "ε" via the metric "d" in the comparison "d"("x", "y")
The Amazing Criswell
Jeron Criswell King (born Jeron Criswell Konig, August 7, 1907 – October 4, 1982), known by his stage-name The Amazing Criswell , was an American psychic known for wildly inaccurate predictions. In person, he went by Charles Criswell King, and was sometimes credited as Jeron King Criswell.
Criswell was flamboyant, with spit curled hair, a stentorian style of speaking, and a sequined tuxedo. He owned a coffin in which he claimed to sleep. He grew up in a troubled family in Indiana with relatives who owned a funeral home, and said that he became comfortable with sleeping in caskets in the storeroom. He appeared in two of Ed Wood's films.
Criswell said he had once worked as a radio announcer and news broadcaster. He began buying time on a local Los Angeles television station in the early 1950s to run infomercials for his Criswell Family Vitamins. To fill the time, he began his "Criswell Predicts" part of the show. This made him a minor off-beat celebrity in Los Angeles and around Hollywood, and his friendship with old show-business people such as Mae West and rising fringe celebrities such as Korla Pandit made Criswell an entertaining presence at parties. His fame brought him appearances on "The Jack Paar Show" (1957–1962) which allowed him to publish his predictions in three publications of Spaceway Magazine (February 1955, April 1955, and June 1955), as well as run a weekly syndicated newspaper article starting on September 6, 1951. He later published three books of predictions; "From Now to the Year 2000", "Your Next Ten Years", and "Forbidden Predictions". He also recorded a long playing record, "Your Incredible Future" (which was later released on CD), featuring 84 minutes of his predictions in his own voice. Criswell appeared in the movies of writer and director Ed Wood. After Criswell's death, his longtime friend Paul Marco released Criswell's song "Someone Walked Over My Grave" on a 7" record which was recorded by Criswell as a memorial song that he wanted released posthumously.
Criswell's predictions were nationally syndicated and he appeared on the television show "Criswell Predicts" on KLAC Channel 13 (now KCOP-13) in Los Angeles as well as being recorded for syndication. His announcer was Bob Shields, who later played the judge on "Divorce Court". Criswell wore heavy makeup in public after his live program was broadcast in Los Angeles. Only selected people were allowed in the KCOP studio during his broadcast.
Criswell wrote several books of predictions, including 1968's "Criswell Predicts: From Now to the Year 2000." In it, he claimed that Denver, Colorado would be struck by a ray from space that would cause all metal to adopt the qualities of rubber, leading to horrific accidents at amusement parks. He predicted mass cannibalism and the end of planet Earth, which he set as happening on August 18, 1999.
Criswell was a student of history. He believed history repeated itself, that the United States were the "modern Romans". Each day, he read the "St. Louis Post-Dispatch" looking for clues for his predictions.
Some sources claim Criswell's most famous prediction was on "The Jack Paar Program" (1962–65) in March 1963, when he predicted that US President John F. Kennedy would not run for reelection in 1964 because something was going to happen to him in November 1963.
Sources say that Criswell never claimed to be a real psychic; however, those who knew him, including actress and fellow "Plan 9" alumna Maila Nurmi ("Vampira"), believed he was. According to writer Charles A. Coulombe, whose family rented an apartment from him, Criswell told Coulombe's father "[I] had the gift, but ... lost it when I started taking money for it."
Criswell married a former speakeasy dancer named Halo Meadows, who once appeared on "You Bet Your Life", and whom Coulombe describes as "quite mad": "Mrs Criswell had a huge standard poodle (named "Buttercup") which she was convinced was the reincarnation of her cousin Thomas. She spent a great deal of time sunbathing ... which, given her size, was not too pleasing a sight."
Mae West used Criswell as her personal psychic; he once predicted her rise to President of the United States, whereupon she, Criswell and George Liberace, the brother of showman Liberace, would take a rocket to the Moon. Criswell and West were great friends and she would lavish him with home-cooked food which she had delivered to the studio that he shared with Maila Nurmi ("Vampira"). It is said that West sold Criswell her old luxury cars for five dollars.
He died in 1982 aged 75.
Chain reaction
A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events.
Chain reactions are one way that systems which are not in thermodynamic equilibrium can release energy or increase entropy in order to reach a state of higher entropy. For example, a system may not be able to reach a lower energy state by releasing energy into the environment, because it is hindered or prevented in some way from taking the path that will result in the energy release. If a reaction results in a small energy release making way for more energy releases in an expanding chain, then the system will typically collapse explosively until much or all of the stored energy has been released.
A macroscopic metaphor for chain reactions is thus a snowball causing a larger snowball until finally an avalanche results ("snowball effect"). This is a result of stored gravitational potential energy seeking a path of release over friction. Chemically, the equivalent to a snow avalanche is a spark causing a forest fire. In nuclear physics, a single stray neutron can result in a prompt critical event, which may finally be energetic enough for a nuclear reactor meltdown or (in a bomb) a nuclear explosion.
Numerous chain reactions can be represented by a mathematical model based on Markov chains.
In 1913, the German chemist Max Bodenstein first put forth the idea of chemical chain reactions. If two molecules react, not only molecules of the final reaction products are formed, but also some unstable molecules which can further react with the parent molecules with a far larger probability than the initial reactants. (In the new reaction, further unstable molecules are formed besides the stable products, and so on.)
In 1918, Walther Nernst proposed that the photochemical reaction between hydrogen and chlorine is a chain reaction in order to explain what's known as the "quantum yield" phenomena. This means that one photon of light is responsible for the formation of as many as 106 molecules of the product HCl. Nernst suggested that the photon dissociates a Cl2 molecule into two Cl atoms which each initiate a long chain of reaction steps forming HCl.
In 1923, Danish and Dutch scientists Christian Christiansen and Hendrik Anthony Kramers, in an analysis of the formation of polymers, pointed out that such a chain reaction need not start with a molecule excited by light, but could also start with two molecules colliding violently due to thermal energy as previously proposed for initiation of chemical reactions by van' t Hoff.
Christiansen and Kramers also noted that if, in one link of the reaction chain, two or more unstable molecules are produced, the reaction chain would branch and grow. The result is in fact an exponential growth, thus giving rise to explosive increases in reaction rates, and indeed to chemical explosions themselves. This was the first proposal for the mechanism of chemical explosions.
A quantitative chain chemical reaction theory was created later on by Soviet physicist Nikolay Semyonov in 1934. Semyonov shared the Nobel Prize in 1956 with Sir Cyril Norman Hinshelwood, who independently developed many of the same quantitative concepts.
The main types of steps in chain reaction are of the following types.
The "chain length" is defined as the average number of times the propagation cycle is repeated, and equals the overall reaction rate divided by the initiation rate.
Some chain reactions have complex rate equations with fractional order or mixed order kinetics.
The reaction H2 + Br2 → 2 HBr proceeds by the following mechanism:
As can be explained using the steady-state approximation, the thermal reaction has an initial rate of fractional order (3/2), and a complete rate equation with a two-term denominator (mixed-order kinetics).
A "nuclear" chain reaction was proposed by Leo Szilard in 1933, shortly after the neutron was discovered, yet more than five years before nuclear fission was first discovered. Szilárd knew of "chemical" chain reactions, and he had been reading about an energy-producing nuclear reaction involving high-energy protons bombarding lithium, demonstrated by John Cockcroft and Ernest Walton, in 1932. Now, Szilárd proposed to use neutrons theoretically produced from certain nuclear reactions in lighter isotopes, to induce further reactions in light isotopes that produced more neutrons. This would in theory produce a chain reaction at the level of the nucleus. He did not envision fission as one of these neutron-producing reactions, since this reaction was not known at the time. Experiments he proposed using beryllium and indium failed.
Later, after fission was discovered in 1938, Szilárd immediately realized the possibility of using neutron-induced fission as the particular nuclear reaction necessary to create a chain-reaction, so long as fission also produced neutrons. In 1939, with Enrico Fermi, Szilárd proved this neutron-multiplying reaction in uranium. In this reaction, a neutron plus a fissionable atom causes a fission resulting in a larger number of neutrons than the single one that was consumed in the initial reaction. Thus was born the practical nuclear chain reaction by the mechanism of neutron-induced nuclear fission.
Specifically, if one or more of the produced neutrons themselves interact with other fissionable nuclei, and these also undergo fission, then there is a possibility that the macroscopic overall fission reaction will not stop, but continue throughout the reaction material. This is then a self-propagating and thus self-sustaining chain reaction. This is the principle for nuclear reactors and atomic bombs.
Demonstration of a self-sustaining nuclear chain reaction was accomplished by Enrico Fermi and others, in the successful operation of Chicago Pile-1, the first artificial nuclear reactor, in late 1942.
An electron avalanche happens between two unconnected electrodes in a gas when an electric field exceeds a certain threshold. Random thermal collisions of gas atoms may result in a few free electrons and positively charged gas ions, in a process called impact ionization. Acceleration of these free electrons in a strong electric field causes them to gain energy, and when they impact other atoms, the energy causes release of new free electrons and ions (ionization), which fuels the same process. If this process happens faster than it is naturally quenched by ions recombining, the new ions multiply in successive cycles until the gas breaks down into a plasma and current flows freely in a discharge.
Electron avalanches are essential to the dielectric breakdown process within gases. The process can culminate in corona discharges, streamers, leaders, or in a spark or continuous electric arc that completely bridges the gap. The process may extend huge sparks — streamers in lightning discharges propagate by formation of electron avalanches created in the high potential gradient ahead of the streamers' advancing tips. Once begun, avalanches are often intensified by the creation of photoelectrons as a result of ultraviolet radiation emitted by the excited medium's atoms in the aft-tip region. The extremely high temperature of the resulting plasma cracks the surrounding gas molecules and the free ions recombine to create new chemical compounds.
The process can also be used to detect radiation that initiates the process, as the passage of a single particles can be amplified to large discharges. This is the mechanism of a Geiger counter and also the visualization possible with a spark chamber and other wire chambers.
An avalanche breakdown process can happen in semiconductors, which in some ways conduct electricity analogously to a mildly ionized gas. Semiconductors rely on free electrons knocked out of the crystal by thermal vibration for conduction. Thus, unlike metals, semiconductors become better conductors the higher the temperature. This sets up conditions for the same type of positive feedback—heat from current flow causes temperature to rise, which increases charge carriers, lowering resistance, and causing more current to flow. This can continue to the point of complete breakdown of normal resistance at a semiconductor junction, and failure of the device (this may be temporary or permanent depending on whether there is physical damage to the crystal). Certain devices, such as avalanche diodes, deliberately make use of the effect.
Caddie
In golf, a caddie (or caddy) is the person who carries a player's bag and clubs, and gives insightful advice and moral support, almost like a teacher.
A good caddie is aware of the challenges and obstacles of the golf course being played, along with the best strategy in playing it. This includes knowing overall yardage, pin placements and club selection. A caddie is not usually an employee of a private club or resort. They are classified as an "independent contractor", meaning that they are basically self-employed and do not receive any benefits or perks from their association with the club. Some clubs and resorts do have caddie programs, although benefits are rarely offered. Particularly in Europe, the vast majority of clubs do not offer caddies, and amateur players will commonly carry or pull their own bags.
The first caddies appeared in 1817 in Edinburgh. It is believed that the first use of a caddie was by The Duke of Albany of Scotland in 1681 while playing the first international golf contest at Leith Links, which resulted in the construction of Golfers Land in Edinburgh.
The Scots word "caddie" or "cawdy" was derived in the 17th century from the French word "cadet" and originally meant a student military officer. It later came to refer to someone who did odd jobs. By the 19th century, it had come to mean someone who carried clubs for a golfer, or in its shortened form, cad, a man of disreputable behaviour.
Traditional caddying involves both the golfer and the caddie walking the course. The caddie is in charge of carrying the player's bag, keeping the clubs clean, and washing the ball when on the green, and walks ahead of the golfer to locate their ball and calculate the yardage to the pin and/or hazards. Sometimes, a caddy is asked for opinions such as what/where to hit or where to aim a putt. This is the most common method used in golf clubs and is the only method allowed in the PGA (Professional Golf Association) and LPGA (Ladies Professional Golf Association). The three usual "ups" of caddying are: show up, shut up, and keep up.
Fore-Caddying entails the caddie walking while the players ride in carts. The fore-caddie will give a hole description and then walk ahead to spot the players' tee shots. The caddie then gets the player's yardage (either with a GPS watch, laser, course knowledge, or sprinkler heads) while the players drive their carts from the tee to their shots. The caddie walks ahead again to spot the golfer's next shots. This process is continued until the players reach the green. Once on the green the caddie will read greens (if asked per proper golf etiquette), clean golf balls (if asked), fix ball marks, and attend the flag. The usual rule is that the first golfer on the green's caddy tends the flag. The caddie is also responsible for raking traps on the course. Caddies may be asked to help with club selection, reading greens, weather variables, and marking balls on the green. More than anything else, the caddie is there to make the player's round enjoyable by taking care of menial tasks, speeding up play, and providing mental support if asked.
Many clubs use a ranking system. Caddies will start as a trainee, and be promoted through the ranks of Intermediate, Captain, Honor, and finally Championship. Many courses start their caddies off at the B level, and after a year move them to A, and on their fourth year (if they have earned it), they will receive the title of Honor caddie. The intermediate and captain ranks can usually be obtained within the first year of caddying, and the honor rank is usually obtained in the second or third year of caddying. Championship takes at least 6 years and often as many as 10 years to obtain. An alternative ranking system often used in the American Mid-West proceeds as B level, A level, AA level, Honor level, and Evans Scholar. Caddies often obtain a promotion in rank once a year, while often Honor takes two years to achieve and Evans Scholars are only produced by winning the venerable Evans Scholarship for university. However, in many American clubs, caddies are divided simply between "B" caddies (usually younger, less experienced caddies who often carry only one bag), and "A" caddies (usually older, more experienced caddies).
Caddies report early each morning at the "Caddy Shack" where they wait until the caddie master assigns them to a golfer. At that time, they retrieve the golfers bag (typically from the bag room) and wait to meet the golfer out in an open area.
When done with the morning round of golf(a loop), the caddie can either wait to work an afternoon "loop" or go home. Sometimes caddies show up late in the morning to only work afternoons where some days of the week it can be pretty slow in the morning.
Caddies typically work at clubs all week except Mondays with most traffic on weekends, being the busiest days. Additionally, caddies are often allowed to play the course at which they caddie for free, usually on a Monday (the day that most private clubs choose to close their course for maintenance). On pro golf tours, professional caddies accompany their player to all events, which usually take place from Thursday through Sunday. Additionally, the player may hire their caddie to carry their bag for them during training sessions and practice rounds.
At most clubs, caddies are paid at the end of the round by cash, or receive a payment ticket for which they can redeem their wages in the clubhouse. Generally, the player will tip the caddie based on their performance during the round, with extra money given for exemplary work or for working special event such as a tournament. Most American club caddies earn between $80 and $120 per bag, though newer caddies will often earn less than more experienced caddies. Caddies working during a tournament, high-stakes match, or 4-Day member-guest will often earn significantly more, upwards of $150 per round, per bag, at times. It is common for experienced caddies to carry two bags(a "Double") at a time. It is considered acceptable to ask a professional at the course what the average pay for a caddie is, as courses differ.
In a professional golf tour setting, a player often pays their caddie a percentage of their winnings, which can be as high as 10 percent. A common pay scale is 5 percent for making the cut, 7 percent for a top 10, and 10 percent for a win. The caddie also usually receives a salary, as the player is not guaranteed to win money at every tournament.
Beginning in the 2020 season, caddies on the European Tour will be eligible to earn bonuses through sponsors' logos on hats, bags, towels, and other caddie tools.
Caddies have been depicted in TV, films, and books, including:
Compound turbine
A compound turbine is a steam turbine in which there are two casings, a high-pressure casing and a low-pressure casing, operating in concert to extract work from a single source of steam. The steam is partially expanded in the high-pressure casing, then exhausted to the low-pressure casing.
The rotor arrangement can be either tandem-compound in which the two axles are joined end to end, or cross-compound in which the two turbines have separate axles. In the cross-compound case two separate generators are usually supplied, although a gearbox can reduce this to one.
The principal advantages of compound turbines are the reduction in size of any one casing, the confinement of the highest pressure to the smaller casing (which may be made of stronger and more expensive materials) and the possibility of divided flow in the low-pressure casing for the purpose of equalizing end thrusts. | https://en.wikipedia.org/wiki?curid=7832 |
Chain reaction
A chain reaction is a sequence of reactions where a reactive product or by-product causes additional reactions to take place. In a chain reaction, positive feedback leads to a self-amplifying chain of events.
Chain reactions are one way that systems which are not in thermodynamic equilibrium can release energy or increase entropy in order to reach a state of higher entropy. For example, a system may not be able to reach a lower energy state by releasing energy into the environment, because it is hindered or prevented in some way from taking the path that will result in the energy release. If a reaction results in a small energy release making way for more energy releases in an expanding chain, then the system will typically collapse explosively until much or all of the stored energy has been released.
A macroscopic metaphor for chain reactions is thus a snowball causing a larger snowball until finally an avalanche results ("snowball effect"). This is a result of stored gravitational potential energy seeking a path of release over friction. Chemically, the equivalent to a snow avalanche is a spark causing a forest fire. In nuclear physics, a single stray neutron can result in a prompt critical event, which may finally be energetic enough for a nuclear reactor meltdown or (in a bomb) a nuclear explosion.
Numerous chain reactions can be represented by a mathematical model based on Markov chains.
In 1913, the German chemist Max Bodenstein first put forth the idea of chemical chain reactions. If two molecules react, not only molecules of the final reaction products are formed, but also some unstable molecules which can further react with the parent molecules with a far larger probability than the initial reactants. (In the new reaction, further unstable molecules are formed besides the stable products, and so on.)
In 1918, Walther Nernst proposed that the photochemical reaction between hydrogen and chlorine is a chain reaction in order to explain what's known as the "quantum yield" phenomena. This means that one photon of light is responsible for the formation of as many as 106 molecules of the product HCl. Nernst suggested that the photon dissociates a Cl2 molecule into two Cl atoms which each initiate a long chain of reaction steps forming HCl.
In 1923, Danish and Dutch scientists Christian Christiansen and Hendrik Anthony Kramers, in an analysis of the formation of polymers, pointed out that such a chain reaction need not start with a molecule excited by light, but could also start with two molecules colliding violently due to thermal energy as previously proposed for initiation of chemical reactions by van' t Hoff.
Christiansen and Kramers also noted that if, in one link of the reaction chain, two or more unstable molecules are produced, the reaction chain would branch and grow. The result is in fact an exponential growth, thus giving rise to explosive increases in reaction rates, and indeed to chemical explosions themselves. This was the first proposal for the mechanism of chemical explosions.
A quantitative chain chemical reaction theory was created later on by Soviet physicist Nikolay Semyonov in 1934. Semyonov shared the Nobel Prize in 1956 with Sir Cyril Norman Hinshelwood, who independently developed many of the same quantitative concepts.
The main types of steps in chain reaction are of the following types.
The "chain length" is defined as the average number of times the propagation cycle is repeated, and equals the overall reaction rate divided by the initiation rate.
Some chain reactions have complex rate equations with fractional order or mixed order kinetics.
The reaction H2 + Br2 → 2 HBr proceeds by the following mechanism:
As can be explained using the steady-state approximation, the thermal reaction has an initial rate of fractional order (3/2), and a complete rate equation with a two-term denominator (mixed-order kinetics).
A "nuclear" chain reaction was proposed by Leo Szilard in 1933, shortly after the neutron was discovered, yet more than five years before nuclear fission was first discovered. Szilárd knew of "chemical" chain reactions, and he had been reading about an energy-producing nuclear reaction involving high-energy protons bombarding lithium, demonstrated by John Cockcroft and Ernest Walton, in 1932. Now, Szilárd proposed to use neutrons theoretically produced from certain nuclear reactions in lighter isotopes, to induce further reactions in light isotopes that produced more neutrons. This would in theory produce a chain reaction at the level of the nucleus. He did not envision fission as one of these neutron-producing reactions, since this reaction was not known at the time. Experiments he proposed using beryllium and indium failed.
Later, after fission was discovered in 1938, Szilárd immediately realized the possibility of using neutron-induced fission as the particular nuclear reaction necessary to create a chain-reaction, so long as fission also produced neutrons. In 1939, with Enrico Fermi, Szilárd proved this neutron-multiplying reaction in uranium. In this reaction, a neutron plus a fissionable atom causes a fission resulting in a larger number of neutrons than the single one that was consumed in the initial reaction. Thus was born the practical nuclear chain reaction by the mechanism of neutron-induced nuclear fission.
Specifically, if one or more of the produced neutrons themselves interact with other fissionable nuclei, and these also undergo fission, then there is a possibility that the macroscopic overall fission reaction will not stop, but continue throughout the reaction material. This is then a self-propagating and thus self-sustaining chain reaction. This is the principle for nuclear reactors and atomic bombs.
Demonstration of a self-sustaining nuclear chain reaction was accomplished by Enrico Fermi and others, in the successful operation of Chicago Pile-1, the first artificial nuclear reactor, in late 1942.
An electron avalanche happens between two unconnected electrodes in a gas when an electric field exceeds a certain threshold. Random thermal collisions of gas atoms may result in a few free electrons and positively charged gas ions, in a process called impact ionization. Acceleration of these free electrons in a strong electric field causes them to gain energy, and when they impact other atoms, the energy causes release of new free electrons and ions (ionization), which fuels the same process. If this process happens faster than it is naturally quenched by ions recombining, the new ions multiply in successive cycles until the gas breaks down into a plasma and current flows freely in a discharge.
Electron avalanches are essential to the dielectric breakdown process within gases. The process can culminate in corona discharges, streamers, leaders, or in a spark or continuous electric arc that completely bridges the gap. The process may extend huge sparks — streamers in lightning discharges propagate by formation of electron avalanches created in the high potential gradient ahead of the streamers' advancing tips. Once begun, avalanches are often intensified by the creation of photoelectrons as a result of ultraviolet radiation emitted by the excited medium's atoms in the aft-tip region. The extremely high temperature of the resulting plasma cracks the surrounding gas molecules and the free ions recombine to create new chemical compounds.
The process can also be used to detect radiation that initiates the process, as the passage of a single particles can be amplified to large discharges. This is the mechanism of a Geiger counter and also the visualization possible with a spark chamber and other wire chambers.
An avalanche breakdown process can happen in semiconductors, which in some ways conduct electricity analogously to a mildly ionized gas. Semiconductors rely on free electrons knocked out of the crystal by thermal vibration for conduction. Thus, unlike metals, semiconductors become better conductors the higher the temperature. This sets up conditions for the same type of positive feedback—heat from current flow causes temperature to rise, which increases charge carriers, lowering resistance, and causing more current to flow. This can continue to the point of complete breakdown of normal resistance at a semiconductor junction, and failure of the device (this may be temporary or permanent depending on whether there is physical damage to the crystal). Certain devices, such as avalanche diodes, deliberately make use of the effect. | https://en.wikipedia.org/wiki?curid=7834 |
Caddie
In golf, a caddie (or caddy) is the person who carries a player's bag and clubs, and gives insightful advice and moral support, almost like a teacher.
A good caddie is aware of the challenges and obstacles of the golf course being played, along with the best strategy in playing it. This includes knowing overall yardage, pin placements and club selection. A caddie is not usually an employee of a private club or resort. They are classified as an "independent contractor", meaning that they are basically self-employed and do not receive any benefits or perks from their association with the club. Some clubs and resorts do have caddie programs, although benefits are rarely offered. Particularly in Europe, the vast majority of clubs do not offer caddies, and amateur players will commonly carry or pull their own bags.
The first caddies appeared in 1817 in Edinburgh. It is believed that the first use of a caddie was by The Duke of Albany of Scotland in 1681 while playing the first international golf contest at Leith Links, which resulted in the construction of Golfers Land in Edinburgh.
The Scots word "caddie" or "cawdy" was derived in the 17th century from the French word "cadet" and originally meant a student military officer. It later came to refer to someone who did odd jobs. By the 19th century, it had come to mean someone who carried clubs for a golfer, or in its shortened form, cad, a man of disreputable behaviour.
Traditional caddying involves both the golfer and the caddie walking the course. The caddie is in charge of carrying the player's bag, keeping the clubs clean, and washing the ball when on the green, and walks ahead of the golfer to locate their ball and calculate the yardage to the pin and/or hazards. Sometimes, a caddy is asked for opinions such as what/where to hit or where to aim a putt. This is the most common method used in golf clubs and is the only method allowed in the PGA (Professional Golf Association) and LPGA (Ladies Professional Golf Association). The three usual "ups" of caddying are: show up, shut up, and keep up.
Fore-Caddying entails the caddie walking while the players ride in carts. The fore-caddie will give a hole description and then walk ahead to spot the players' tee shots. The caddie then gets the player's yardage (either with a GPS watch, laser, course knowledge, or sprinkler heads) while the players drive their carts from the tee to their shots. The caddie walks ahead again to spot the golfer's next shots. This process is continued until the players reach the green. Once on the green the caddie will read greens (if asked per proper golf etiquette), clean golf balls (if asked), fix ball marks, and attend the flag. The usual rule is that the first golfer on the green's caddy tends the flag. The caddie is also responsible for raking traps on the course. Caddies may be asked to help with club selection, reading greens, weather variables, and marking balls on the green. More than anything else, the caddie is there to make the player's round enjoyable by taking care of menial tasks, speeding up play, and providing mental support if asked.
Many clubs use a ranking system. Caddies will start as a trainee, and be promoted through the ranks of Intermediate, Captain, Honor, and finally Championship. Many courses start their caddies off at the B level, and after a year move them to A, and on their fourth year (if they have earned it), they will receive the title of Honor caddie. The intermediate and captain ranks can usually be obtained within the first year of caddying, and the honor rank is usually obtained in the second or third year of caddying. Championship takes at least 6 years and often as many as 10 years to obtain. An alternative ranking system often used in the American Mid-West proceeds as B level, A level, AA level, Honor level, and Evans Scholar. Caddies often obtain a promotion in rank once a year, while often Honor takes two years to achieve and Evans Scholars are only produced by winning the venerable Evans Scholarship for university. However, in many American clubs, caddies are divided simply between "B" caddies (usually younger, less experienced caddies who often carry only one bag), and "A" caddies (usually older, more experienced caddies).
Caddies report early each morning at the "Caddy Shack" where they wait until the caddie master assigns them to a golfer. At that time, they retrieve the golfers bag (typically from the bag room) and wait to meet the golfer out in an open area.
When done with the morning round of golf(a loop), the caddie can either wait to work an afternoon "loop" or go home. Sometimes caddies show up late in the morning to only work afternoons where some days of the week it can be pretty slow in the morning.
Caddies typically work at clubs all week except Mondays with most traffic on weekends, being the busiest days. Additionally, caddies are often allowed to play the course at which they caddie for free, usually on a Monday (the day that most private clubs choose to close their course for maintenance). On pro golf tours, professional caddies accompany their player to all events, which usually take place from Thursday through Sunday. Additionally, the player may hire their caddie to carry their bag for them during training sessions and practice rounds.
At most clubs, caddies are paid at the end of the round by cash, or receive a payment ticket for which they can redeem their wages in the clubhouse. Generally, the player will tip the caddie based on their performance during the round, with extra money given for exemplary work or for working special event such as a tournament. Most American club caddies earn between $80 and $120 per bag, though newer caddies will often earn less than more experienced caddies. Caddies working during a tournament, high-stakes match, or 4-Day member-guest will often earn significantly more, upwards of $150 per round, per bag, at times. It is common for experienced caddies to carry two bags(a "Double") at a time. It is considered acceptable to ask a professional at the course what the average pay for a caddie is, as courses differ.
In a professional golf tour setting, a player often pays their caddie a percentage of their winnings, which can be as high as 10 percent. A common pay scale is 5 percent for making the cut, 7 percent for a top 10, and 10 percent for a win. The caddie also usually receives a salary, as the player is not guaranteed to win money at every tournament.
Beginning in the 2020 season, caddies on the European Tour will be eligible to earn bonuses through sponsors' logos on hats, bags, towels, and other caddie tools.
Caddies have been depicted in TV, films, and books, including: | https://en.wikipedia.org/wiki?curid=7837 |
Compound turbine
A compound turbine is a steam turbine in which there are two casings, a high-pressure casing and a low-pressure casing, operating in concert to extract work from a single source of steam. The steam is partially expanded in the high-pressure casing, then exhausted to the low-pressure casing.
The rotor arrangement can be either tandem-compound in which the two axles are joined end to end, or cross-compound in which the two turbines have separate axles. In the cross-compound case two separate generators are usually supplied, although a gearbox can reduce this to one.
The principal advantages of compound turbines are the reduction in size of any one casing, the confinement of the highest pressure to the smaller casing (which may be made of stronger and more expensive materials) and the possibility of divided flow in the low-pressure casing for the purpose of equalizing end thrusts. | https://en.wikipedia.org/wiki?curid=7838 |
Autumn
Autumn, also known as fall in North American English, is one of the four temperate seasons. Autumn marks the transition from summer to winter, in September (Northern Hemisphere) or March (Southern Hemisphere), when the duration of daylight becomes noticeably shorter and the temperature cools considerably. One of its main features in temperate climates is the shedding of leaves from deciduous trees.
Some cultures regard the autumnal equinox as "mid-autumn", while others with a longer temperature lag treat it as the start of autumn. Meteorologists (and most of the temperate countries in the southern hemisphere) use a definition based on Gregorian calendar months, with autumn being September, October, and November in the northern hemisphere, and March, April, and May in the southern hemisphere. Persians celebrate the beginning of the autumn as Mehregan to honor Mithra (Mehr).
In North America, autumn traditionally starts with the September equinox (21 to 24 September) and ends with the winter solstice (21 or 22 December). Popular culture in the United States associates Labor Day, the first Monday in September, as the end of summer and the start of autumn; certain summer traditions, such as wearing white, are discouraged after that date. As daytime and nighttime temperatures decrease, trees change color and then shed their leaves. In traditional East Asian solar term, autumn starts on or around 8 August and ends on or about 7 November. In Ireland, the autumn months according to the national meteorological service, Met Éireann, are September, October and November. However, according to the Irish Calendar, which is based on ancient Gaelic traditions, autumn lasts throughout the months of August, September and October, or possibly a few days later, depending on tradition. In the Irish language, September is known as "Meán Fómhair" ("middle of autumn") and October as "Deireadh Fómhair" ("end of autumn").
In southern hemisphere countries such as Australia and New Zealand, which tend to base their seasonal calendars meteorologically rather than astronomically, autumn officially begins on 1 March and ends on 31 May.
The word "autumn" is derived from Latin "autumnus", archaic "auctumnus", possibly from the ancient Etruscan root "autu-" and has within it connotations of the passing of the year. Alternative etymologies include Proto-Indo-European *"h₃ewǵ"- (“cold”) or *"h₂sows"- (“dry”).
After the Roman era, the word continued to be used as the Old French word ' (' in modern French) or "" in Middle English, and was later normalised to the original Latin. In the Medieval period, there are rare examples of its use as early as the 12th century, but by the 16th century, it was in common use.
Before the 16th century, "harvest" was the term usually used to refer to the season, as it is common in other West Germanic languages to this day (cf. Dutch ', German ' and Scots ""). However, as more people gradually moved from working the land to living in towns, the word "harvest" lost its reference to the time of year and came to refer only to the actual activity of reaping, and "autumn", as well as "fall", began to replace it as a reference to the season.
The alternative word "fall" for the season traces its origins to old Germanic languages. The exact derivation is unclear, with the Old English ' or ' and the Old Norse "" all being possible candidates. However, these words all have the meaning "to fall from a height" and are clearly derived either from a common root or from each other. The term came to denote the season in 16th-century England, a contraction of Middle English expressions like "fall of the leaf" and "fall of the year". Compare the origin of "spring" from "spring of the leaf" and "spring of the year".
During the 17th century, English emigration to the British colonies in North America was at its peak, and the new settlers took the English language with them. While the term "fall" gradually became nearly obsolete in Britain, it became the more common term in North America.
The name "backend", a once common name for the season in Northern England, has today been largely replaced by the name "autumn".
Association with the transition from warm to cold weather, and its related status as the season of the primary harvest, has dominated its themes and popular images. In Western cultures, personifications of autumn are usually pretty, well-fed females adorned with fruits, vegetables and grains that ripen at this time. Many cultures feature autumnal harvest festivals, often the most important on their calendars. Still extant echoes of these celebrations are found in the autumn Thanksgiving holiday of the United States and Canada, and the Jewish Sukkot holiday with its roots as a full-moon harvest festival of "tabernacles" (living in outdoor huts around the time of harvest). There are also the many North American Indian festivals tied to harvest of ripe foods gathered in the wild, the Chinese Mid-Autumn or Moon festival, and many others. The predominant mood of these autumnal celebrations is a gladness for the fruits of the earth mixed with a certain melancholy linked to the imminent arrival of harsh weather.
This view is presented in English poet John Keats' poem "To Autumn", where he describes the season as a time of bounteous fecundity, a time of 'mellow fruitfulness'.
In North America, while most foods are harvested during the autumn, foods particularly associated with the season include pumpkins (which are integral parts of both Thanksgiving and Halloween) and apples, which are used to make the seasonal beverage apple cider.
Autumn, especially in poetry, has often been associated with melancholia. The possibilities and opportunities of summer are gone, and the chill of winter is on the horizon. Skies turn grey, the amount of usable daylight drops rapidly, and many people turn inward, both physically and mentally. It has been referred to as an unhealthy season.
Similar examples may be found in Irish poet William Butler Yeats' poem "The Wild Swans at Coole" where the maturing season that the poet observes symbolically represents his own ageing self. Like the natural world that he observes, he too has reached his prime and now must look forward to the inevitability of old age and death. French poet Paul Verlaine's ""Chanson d'automne"" ("Autumn Song") is likewise characterised by strong, painful feelings of sorrow. Keats' "To Autumn", written in September 1819, echoes this sense of melancholic reflection, but also emphasises the lush abundance of the season. The song "Autumn Leaves", based on the French song "Les Feuilles mortes", uses the melancholic atmosphere of the season and the end of summer as a metaphor for the mood of being separated from a loved one.
Autumn is associated with Halloween (influenced by Samhain, a Celtic autumn festival), and with it a widespread marketing campaign that promotes it. Halloween, October 31, is in autumn in the northern hemisphere. The television, film, book, costume, home decoration, and confectionery industries use this time of year to promote products closely associated with such a holiday, with promotions going from late August or early September to 31 October, since their themes rapidly lose strength once the holiday ends, and advertising starts concentrating on Christmas.
In some parts of the northern hemisphere, autumn has a strong association with the end of summer holiday and the start of a new school year, particularly for children in primary and secondary education. "Back to School" advertising and preparations usually occurs in the weeks leading to the beginning of autumn.
Easter falls in autumn in the southern hemisphere.
Thanksgiving Day is a national holiday celebrated in Canada, in the United States, in some of the Caribbean islands and in Liberia. Thanksgiving is celebrated on the second Monday of October in Canada and on the fourth Thursday of November in the United States, and around the same part of the year in other places. Similarly named festival holidays occur in Germany and Japan.
Television stations and networks, particularly in North America, traditionally begin their regular seasons in their autumn, with new series and new episodes of existing series debuting mostly during late September or early October (series that debut outside the fall season are usually known as mid-season replacements). A sweeps period takes place in November to measure Nielsen Ratings.
American football is played almost exclusively in the autumn months; at the high school level, seasons run from late August through early November, with some playoff games and holiday rivalry contests being played as late as Thanksgiving. In many American states, the championship games take place in early December. College football's regular season runs from September through November, while the main professional circuit, the National Football League, plays from September through to early January. Summer sports, such as stock car racing, Canadian football, Major League Soccer, and Major League Baseball, wrap up their seasons in early to late autumn; MLB's championship World Series is known popularly as the "Fall Classic". (Amateur baseball is usually finished by August.) Likewise, professional winter sports, such as ice hockey, basketball, and most leagues of association football in Europe, are in the early stages of their seasons during autumn; American college basketball and college ice hockey play teams outside their athletic conferences during the late autumn before their in-conference schedules begin in winter.
The Christian religious holidays of All Saints' Day and All Souls' Day are observed in autumn in the Northern hemisphere.
Since 1997, Autumn has been one of the top 100 names for girls in the United States.
In Indian mythology, autumn is considered to be the preferred season for the goddess of learning Saraswati, who is also known by the name of "goddess of autumn" (Sharada).
In Asian mysticism, Autumn is associated with the element of metal, and subsequently with the colour white, the White Tiger of the West, and death and mourning.
Although colour change in leaves occurs wherever deciduous trees are found, coloured autumn foliage is noted in various regions of the world: most of North America, Eastern Asia (including China, Korea, and Japan), Europe, the forest of Patagonia, eastern Australia and New Zealand's South Island.
Eastern Canada and New England are famous for their autumnal foliage, and this attracts major tourism (worth billions of US dollars) for the regions. | https://en.wikipedia.org/wiki?curid=3049 |
Alameda, California
Alameda ( ; Spanish: ) is a city in Alameda County, California, United States. It is located on Alameda Island and Bay Farm Island. It is adjacent to and south of Oakland and east of San Francisco across the San Francisco Bay. Bay Farm Island, a portion of which is also known as "Harbor Bay Isle", is part of the mainland adjacent to Oakland International Airport. The city's estimated 2019 population was 77,624. Alameda is a charter city, rather than a general law city, which allows it to provide for any form of government. Alameda became a charter city and adopted a council–manager government in 1916.
Alameda occupies what was originally a peninsula connected to Oakland. Much of it was low-lying and marshy. The higher ground nearby and adjacent parts of what is now downtown Oakland were the site of one of the largest coastal oak forests in the world. Spanish colonists called the area "Encinal", meaning "forest of evergreen oak". "Alameda" is Spanish for "grove of poplar trees," or "tree-lined avenue." It was chosen as the name of the city in 1853 by popular vote.
The inhabitants at the time of the arrival of the Spanish in the late 18th century were a local band of the Ohlone tribe. The peninsula was included in the vast Rancho San Antonio granted in 1820 to Luis Peralta by the Spanish king who claimed California. The grant was later confirmed by the Republic of Mexico upon its independence in 1821 from Spain.
Over time, the place became known as Bolsa de Encinal or Encinal de San Antonio.
The city was founded on June 6, 1853, after the United States acquired California following the Mexican-American War of 1848. The town originally contained three small settlements. "Alameda" referred to the village at Encinal and High streets, Hibbardsville was located at the North Shore ferry and shipping terminal, and Woodstock was on the west near the ferry piers of the South Pacific Coast Railroad and the Central Pacific. Eventually, the Central Pacific's ferry pier became the Alameda Mole, featuring transit connections among the San Francisco ferries, local trollies, and Southern Pacific (formerly Central Pacific) commuter lines.
The first post office opened in 1854. The first school, Schermerhorn School, was opened in 1855 (and eventually was renamed as Lincoln School); Encinal School was opened in 1860 (and closed in 1980). The San Francisco and Alameda Railroad opened the Encinal station in 1864. The Encinal area was also known as Fasskings Station in honor of Frederick Louis Fassking. Encinal's own post office opened in 1876, was renamed West End in 1877, and closed in 1891. The West End area was originally called Bowman's Point in honor of Charles G. Bowman, an early United States settler.
On September 6, 1869, the Alameda Terminal made history; it was the site of the arrival of the first train via the First Transcontinental Railroad to reach the shores of San Francisco Bay, thus achieving the first coast to coast transcontinental railroad in North America. The transcontinental terminus was switched to the Oakland Pier two months later, on November 8, 1869.
The borders of Alameda were made coextensive with the island in 1872, incorporating Woodstock into Alameda. In his autobiography, writer Mark Twain described Alameda as "The Garden of California."
In 1917, a private entertainment park called Neptune Beach was built in the area now known as Crab Cove. Often compared to Coney Island in Brooklyn, New York, the park was a major recreation destination in the 1920s and 1930s. The original owners, the Strehlow family, partnered with a local confectioner to create treats unique to Neptune Beach. Both the American snow cone and the popsicle were first sold at Neptune Beach. The Kewpie doll, hand-painted and dressed in unique hand-sewn dresses, became the original prize for winning games of chance at the beach – another Neptune Beach innovation. The Strehlows owned and operated the beach on their own. They filled in a section of the bay to add an additional Olympic-size swimming pool and a roller coaster, which must have given riders a tremendous view of the bay. The "Cottage Baths" were available for rent.
Neptune Beach's two large outdoor pools hosted swimming races and exhibitions by such notable swimmers such as Olympian Johnny Weissmuller and Jack LaLanne. Weissmuller later starred in films as the original Tarzan character. LaLanne started a longlasting chain of health clubs and appeared on television. The park closed down in 1939 because the Great Depression left many people without much money, the completion of the San Francisco–Oakland Bay Bridge changed traffic patterns, people avoided paying the admission price, and the rise of car culture gave people many more choices for recreation destinations.
Once the Bay Bridge was complete, the rail lines, which ran past the entrance to Neptune Beach on the way to the Alameda Mole and the Ferry, lost passengers in great number as people shifted to automobiles. People began using their cars to escape the city and the close suburbs like Alameda and traveled further afield in California. More distant locations appealed to cash-rich San Francisco tourists in the postwar years. Youngsters in town became aware of ways to avoid paying the dime for admission to the park. Strong swimmers or waders could sneak in on the bayside just by swimming around the fence.
Some resort homes and buildings from the Neptune Beach era still exist in present-day Alameda. The Croll Building, on the corner of Webster Street and Central Avenue, was the site of Croll's Gardens and Hotel, used as training quarters for some of the greatest fighters in boxing history from 1883 to 1914. James J. Corbett, Bob Fitzsimmons, Jim Jeffries, Jack Johnson, and several other champions all stayed and trained here. Today, this preserved building has been adapted for retail and restaurants. Neptune Court, a block away on the corner of Central and McKay avenues, is also a surviving building from the resort era.
The vast majority of the Neptune Beach structures – the hand-carved carousel from the world-famed Dentzel Company, the Ferris wheel, the roller coaster, and other rides – were auctioned off in 1940, yielding pennies on the dollar of their original cost. the city did not construct any swimming facilities or develop a local beach to replace that of Neptune Beach.
When the railroad came to town in 1860s, Park Street developed as the major thoroughfare of the city. After the main Alameda train station was located here, residents of Old Alameda pulled up stakes and moved across town to the new downtown. The street's location was chosen by two landowners who wished to attract tenants and development to their land. They designated their mutual property line as Park Street.
The need for expanded shipping facilities and increased flow of current through the estuary led to the dredging of a tidal canal through the marshland between Oakland and Alameda. Construction started in 1874, but it was not completed until 1902, resulting in Alameda becoming an island.
Most of the soil from the canal dredging was used to fill in the nearby marshland. The area of Alameda called Bay Farm Island is no longer an island but is attached by fill to Oakland. In his youth, author Jack London was known to take part in oyster pirating in the highly productive oyster beds near Bay Farm Island, today long gone.
The Alameda Works Shipyard was one of the largest and best-equipped shipyards in the country. Together with other industrial facilities, it became part of the defense industry buildup before and during World War II, which attracted many African-American and European-American migrants from other parts of the United States for the high-paying jobs. In the 1950s, Alameda's industrial and shipbuilding industries thrived along the Alameda Estuary. This was the site of operation of the world's first-ever, land-based, containerized shipping crane.
In the early 21st century, the Port of Oakland, across the estuary, has become one of the largest ports on the West Coast. Its operators use shipping technologies originally experimented within Alameda. As of March 21, 2006, Alameda is a "Coast Guard City", one of seven then designated in the country. As of 2018, it is one of twenty-one within the country.
In addition to the regular trains running to the Alameda Mole, Alameda was also served by local steam commuter lines of the Southern Pacific (initially, the Central Pacific). Alameda was the site of the Southern Pacific's West Alameda Shops, where all the electric trains were maintained and repaired. These were later adapted as the East Bay Electric Lines. Southern Pacific's electrified trains were not streetcars, but full-sized railroad cars that connected to the mainland via bridges at Webster Street and Fruitvale (only the latter bridge survives today). The trains ran to both the Oakland Mole and the Alameda Mole. A line that ran between the two moles was dubbed the "Horseshoe Line" for the shape of the route on a map. Soon after completion of the Bay Bridge, Alameda trains connected directly to San Francisco by the lower deck of the bridge. The ferries became unnecessary.
In the 1930s Pan American Airways established a seaplane port along with the fill that led to the Alameda Mole. This was the original home base for the China Clipper flying boat.
In 1929, the University of California established the San Francisco Airdrome located near the current Webster Street tube as a public airport. The Bay Airdrome had its gala christening party in 1930. The airfield was a busy place, as an early home base for Coastal Air Freight, Varney Air Lines, West Coast Air Transport, Western Air Express, the Transbay Air Ferries, and Boeing's Pacific Air Transport. The Airdrome was closed in 1941 when its air traffic interfered with the newly built Naval Air Station Alameda (NAS Alameda). With the advent of World War II, a vast stretch of the marshy area southwest of the Alameda Mole was filled and the NAS Alameda established. This major Naval facility included a large airfield, as well as docks for several aircraft carriers. It closed in 1997.
Starting in the 1940s and continuing into the 1970s, multiple proposals were considered to build a highway bridge from Alameda to the San Francisco Peninsula, known as the Southern Crossing.
The Bay Area Rapid Transit is currently studying the creation of a second Transbay Tube; some potential alignments would bring BART service to Alameda Island.
In the late 1950s, the Utah Construction Company began a landfill beyond the "Old Sea Wall" and created "South Shore".
On February 7, 1973, a USN Vought A-7E Corsair II fighter jet on a routine training mission from Lemoore Naval Air Station, suddenly caught fire, 28,000 feet over the San Francisco Bay and crashed into the Tahoe Apartments in Alameda. Eleven people, including pilot Lieutenant Robert Lee Ward, died in the crash and fire.
According to the United States Census Bureau, the city has a total area of , of which is land and (53.79%) is water.
Although Alameda's nickname is "The Island City" (or simply "the island"), the current city occupies two islands as well as a small section of the mainland. Today, the city consists of the main original section, with the former Naval Air Station Alameda (NAS Alameda) at the west end of Alameda Island, Southshore along the southern side of Alameda Island, and Bay Farm Island, which is part of the mainland proper. The area of the former NAS is now known as "Alameda Point." The Southshore area is separated from the main part of Alameda Island by a lagoon; the north shore of the lagoon is located approximately where the original south shore of the island was. Alameda Point and Southshore are built on bay fill.
Not all of Alameda Island is part of the City of Alameda. Although nearly all of the island is in Alameda city limits, a small portion of a dump site west of the former runways at Alameda Point extends far enough into San Francisco Bay that it is over the county line and part of the City and County of San Francisco.
Coast Guard Island, a small island between Alameda Island and Oakland, is also part of Alameda and is the home of Integrated Support Command Alameda
This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F. According to the Köppen climate classification system, Alameda has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps. Annual precipitation is about 20 inches, all rain (snow is extremely rare at sea level in the San Francisco Bay area).
The 2010 United States Census reported that Alameda had a population of 73,812. (2015 census estimates place the population at 78,630)
The population density was 3,214.9 people per square mile (1,241.3/km²). The racial makeup of Alameda was 37,460 (50.8%) White, 23,058 (31.2%) Asian, 4,759 (6.4%) African American, 426 (0.6%) Native American, 381 (0.5%) Pacific Islander, 2,463 (3.3%) from other races, and 5,265 (7.1%) from two or more races. Hispanic or Latino of any race were 8,092 persons (11.0%).
The Census reported that 72,316 people (98.0% of the population) lived in households, 857 (1.2%) lived in non-institutionalized group quarters, and 639 (0.9%) were institutionalized.
There were 30,123 households, out of which 9,144 (30.4%) had children under the age of 18 living in them, 13,440 (44.6%) were opposite-sex married couples living together, 3,623 (12.0%) had a female householder with no husband present, 1,228 (4.1%) had a male householder with no wife present. There were 1,681 (5.6%) unmarried opposite-sex partnerships, and 459 (1.5%) same-sex married couples or same-sex partnerships. 9,347 households (31.0%) were made up of individuals and 2,874 (9.5%) had someone living alone who was 65 years of age or older. The average household size was 2.40. There were 18,291 families (60.7% of all households); the average family size was 3.06.
The age distribution of the population shows 15,304 people (20.7%) under the age of 18, 5,489 people (7.4%) aged 18 to 24, 21,000 people (28.5%) aged 25 to 44, 22,044 people (29.9%) aged 45 to 64, and 9,975 people (13.5%) who were 65 years of age or older. The median age was 40.7 years. For every 100 females, there were 91.7 males. For every 100 females age 18 and over, there were 88.5 males.
Per capita money income in past 12 months (2013 dollars), 2009 – 2013 was $41,340.00 per US Census. Median household income, 2009 – 2013 was $74,606.00 per US Census.
There were 32,351 housing units at an average density of 1,409.0 per square mile (544.0/km²), of which 30,123 were occupied, of which 14,488 (48.1%) were owner-occupied, and 15,635 (51.9%) were occupied by renters. The homeowner vacancy rate was 1.1%; the rental vacancy rate was 5.7%. 37,042 people (50.2% of the population) lived in owner-occupied housing units and 35,274 people (47.8%) lived in rental housing units.
As of the census of 2000, there were 72,259 people, 30,226 households, and 17,863 families residing in the city. The population density was 2,583.3/km² (6,693.4/mi²). There were 31,644 housing units at an average density of 1,131.3/km² (2,931.2/mi²). The racial makeup of the city was 56.95% White, 6.21% Black or African American, 0.67% Native American, 26.15% Asian, 0.60% Pacific Islander, 3.29% from other races, and 6.13% from two or more races. 9.31% of the population were Hispanic or Latino of any race.
There were 30,226 households out of which 27.7% had children under the age of 18 living with them, 43.7% were married couples living together, 11.4% had a female householder with no husband present, and 40.9% were non-families. 32.2% of all households were made up of individuals and 9.4% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 3.04.
In the city, the age distribution of the population shows 21.5% under the age of 18, 7.0% from 18 to 24, 33.6% from 25 to 44, 24.6% from 45 to 64, and 13.3% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 92.3 males. For every 100 females age 18 and over, there were 89.5 males.
The median income for a household in the city was $56,285, and the median income for a family was $68,625. Males had a median income of $49,174 versus $40,165 for females. The per capita income for the city was $30,982. About 6.0% of families and 8.2% of the population were below the poverty line, including 11.4% of those under age 18 and 6.1% of those age 65 or over.
There is a large Filipino community; and also a major Portuguese community, from which Tom Hanks' mother came and where Lyndsy Fonseca was raised for some time. Alameda also has a historic Japanese American community and had a small Japanese business district on a portion of Park Street before World War II, when the city's Japanese population was interned. A Japanese Buddhist church is one of the few remaining buildings left of Alameda's pre-war Japanese American community.
According to the California Secretary of State, as of February 10, 2019, Alameda has 48,609 registered voters. Of those, 27,323 (56.2%) are registered Democrats, 5,240 (10.8%) are registered Republicans, and 13,950 (28.7%) have declined to state a political party.
Vehicle access to Alameda Island is via three bridges from Oakland (Park Street, Fruitvale Avenue, and High Street Bridges), as well as the two one-way Posey and Webster Street Tubes leading into Oakland's Chinatown. Connections from Alameda to Bay Farm Island are provided via the Bay Farm Island Bridge for vehicular traffic as well as the Bay Farm Island Bicycle Bridge (the only pedestrian/bicycle-only drawbridge in the United States). California State Route 61 runs down city streets from the Posey and Webster Street Tubes, across the Bay Farm Island Bridge, and south to the Oakland Airport. The island is just minutes off Interstate 880 in Oakland. The speed limit for the city is 25 mph (40 km/h) on almost every road.
Public transportation options include:
Victorian houses comprise 9% of all single-family houses (1500) in Alameda and many more have been divided into two to four-unit dwellings.
Due to its proximity to the Bay, wind surfers and kite surfers can often be seen at Robert W. Crown Memorial State Beach. From the beach, there are also views of the San Francisco skyline and the San Francisco–Oakland Bay Bridge.
The aircraft carrier "USS Hornet", a museum ship, has been moored at the former Naval Air Station as the USS "Hornet" Museum since 1998. This ship was originally named the "USS Kearsarge", but was renamed in honor of the previous "Hornet" (CV-8) (famous for the Doolittle raid), which was lost in October 1942.
Alameda was home to the official offices and training facility of the Oakland Raiders American football team from 1995 until 2020 when the team moved to Las Vegas and the offices and training facility moved to Henderson, Nevada.
At the turn of the 19th century, the city of Alameda took a large chunk of Charles Froling's land away to build a street. Froling had planned to build his dream house on the plot of land he received through inheritance. To spite the city and an unsympathetic neighbor, Froling built a house wide, long and high on the tiny strip of land left to him. The Froling spite house is still standing and occupied.
The Fourth of July parade is advertised as the second oldest and second-longest Fourth of July parade in the United States. It features homemade floats, classic cars, motorized living room furniture, fire-breathing dragons, and marching bands.
The Historic Park Street Business District has many buildings that date back to the 1800s and is a designated Historic Commercial District on the National Register. This main thoroughfare of downtown Alameda Is filled with local shops, restaurants, drinking establishments, and services. The renovated 1932 Alameda Theatre & Cineplex is the cultural centerpiece of the commercial district.
Naval Air Station Alameda (NAS) which was decommissioned in 1997, has been turned over to the City of Alameda for civilian development.
The 33rd America's Cup Race was won by Golden Gate Yacht Club racing team BMW Oracle, founded by Larry Ellison. Possible use of the air station that was considered was to partner with San Francisco for 34th America's Cup.
Within 2 weeks of the Golden Gate Yacht Club winning the America's Cup, Alameda city council with local support sent a unanimous letter of support to hold AC 34 in San Francisco Bay Area. In early 2011, the City Council created an ad hoc America's Cup Citizens Advisory Committee to look for ways that Alameda could draw interest from teams and potential spectators. Through these efforts, the Swedish Artemis Racing team created their team based in one of the former air station hangars on Alameda Point, with a dock at Seaplane Lagoon.
A cluster of artisan distilleries, wineries, breweries and tasting rooms along Monarch Street at Alameda Point is now referred to by the City of Alameda as "Spirits Alley". These business include Rock Wall Winery, Building 43 Winery, Hangar 1, St. George Spirits and Faction Brewing. In 2017, Admiral Maltings opened at Alameda Point. Designed to supply craft brewers and whisky producers, it is the first craft malting house in California.
The modern era of winemaking in Alameda begins in 1978 when Alameda veterinarian Kent Rosenblum and his wife Kathy founded Rosenblum Cellars. In 2008, the company was purchased by Diageo Estates for $105 million. In 2014, the Rosenblum tasting room at Alameda Point closed and moved to Jack London Square in Oakland. Shauna Rosenblum, daughter of Kent and Kathy, is the winemaker for Rock Wall Winery. In December 2007, St. George Absinthe Verte, produced by St. George Spirits became the first brand of American-made absinthe to be legally produced in the United States since a ban was enacted in 1912.
Alameda Island Brewing is located on Park Street.
According to the City's 2016 Comprehensive Annual Financial Report, the top employers in the city are:
Alameda's first newspaper, the "Encinal", appeared in the early 1850s and the paper's editor was instrumental in the movement to incorporate the city. Following the "Encinal", several other papers appeared along geographic lines, and the "Daily Argus" eventually rose to prominence. A young Alameda native, Joseph R. Knowland, wrote political and historical articles for the Alameda papers. Later, Knowland owned the powerful "Oakland Tribune". Around 1900, the "Daily Argus" began to fade in importance and east and west papers "The Times" and "The Star" combined to take the leading role as the "Alameda Times-Star" in the 1930s. The "Times-Star" was sold to the Alameda Newspaper Group in the 1970s.
In 1997, the Hills Newspaper chain was bought by Knight Ridder, at the time, the second-largest newspaper chain in the U.S. Following the buyout, former Hills Newspapers employees recognized the lack of a local community voice in Alameda, and again formed a new locally-based newspaper, the "Alameda Sun", in 2001. In 2006, Knight Ridder announced its impending sale to McClatchy Corp., a Sacramento-based publishing firm. McClatchy Corp. has put the "Contra Costa Times", which under the Knight-Ridder reorganization included all five of the original Hills Newspapers, up for sale. The current owners of the "Alameda Times-Star", Digital First Media, based in Colorado, have announced a strong interest in buying both the "Contra Costa Times" chain and the "San Jose Mercury News", consolidating the daily newspaper market of the East Bay, effectively under one owner. MediaNews closed the "Times-Star" in 2011.
The Alameda community is currently served by two weekly newspapers, the Alameda Journal, owned by the Digital First Media, and the Alameda Sun.
After two previous failures, voters in the city passed a ballot measure in 2000 authorizing a bond measure for construction of a new main library to replace the city's Carnegie Library, damaged during the 1989 Loma Prieta earthquake. The city also received state funds for the new main library and opened the doors to the new facility in November 2006.
There are three library locations: the Main Library in downtown Alameda and two library branches; the Bay Farm Island Library serving the Bay Farm and Harbor Bay communities and the West End Library serving the West End of Alameda.
Founded in 1894, Alameda Hospital is located at Clinton Avenue and Willow Street.
Unlike surrounding communities, Alameda has a municipal power service, Alameda Municipal Power (AMP), that delivers services directly to consumers. AMP sold the majority of its telecommunications business to Comcast in 2008 but continues to provide telecommunication service at Alameda Point.
During the California electricity crisis of 2000 and 2001, Alameda Municipal Power did not raise electricity rates, while residents in most of the state endured significant price increases.
The Alameda Arts Council (AAC) serves as the local Alameda City arts council. The Alameda Civic Ballet is the ballet troupe of the city. The Alameda Museum features displays on the history of Alameda. The Alameda Art Association has about 80 members as of January 2011, and has a gallery space at South Shore Center mall. The Association began in 1944. An annual benefit, Circus for Arts in the Schools, was started by clown artist Jeff Raz in 2004. Photo-realist Robert Bechtle has painted numerous Alameda subjects, including "Alameda Gran Torino", which was acquired by SFMOMA in 1974 and remains one of Bechtle's most famous works.
Alameda has been home to many movie sets. Some of the movies filmed on the island have included "Bicentennial Man", "The Net", "The Matrix Reloaded", "The Matrix Revolutions", "Bee Season", the original 1968 "Your, Mine and Ours" and the movie musical "Rent". Parts of Alameda High School were animated for the "Animatrix" episode "Kid's Story". A massive hangar at the former Naval Air Station Alameda was used to film special scenes requiring computer-generated imagery for movies such as "Bicentennial Man", "Flubber", "What Dreams May Come", "" and many scenes from the "Matrix" trilogy, including the signature bullet time scene. The open space of the decommissioned naval base often hosts "MythBusters"' more dangerous experiments. The movie "Spirit Of '76" was filmed all throughout Alameda.
The documentary, "Shallow Waters: The Public Death of Raymond Zack" was filmed at Alameda locations, and chronicled the 2011 Death of Raymond Zack on Crown Beach in Alameda. The film was screened in 2016 at the Michaan Auction House Theater in Alameda.
The USS "Hornet" Museum, permanently moored at Alameda Point, has been the site for scenes used in major theatrical releases: "", "Rescue Dawn", and "The Master". In addition, the aircraft carrier has been used for television shows such as "JAG", "Carrier", "Looking", "The Great Escape", and the special military episode of "Fear Factor"; plus a number of television commercials.
The city restored the historic Art Deco city landmark Alameda Theatre, expanding it to include a theater multiplex. The public opening was May 21, 2008.
The Altarena Playhouse, which performs comedies, dramas, and musicals, was founded in 1938 and is the longest continuously operating community theater in the San Francisco Bay Area.
Rhythmix Cultural Works (RCW) brings people of all ages together to experience and explore music, dance, visual art, and educational opportunities. RCW's programs are housed in a restored industrial waterfront building that speaks to Alameda's history while creating an inclusive venue that reflects the Bay Area's rich diversity. The organization offers an array of arts programming to the community including Island Arts, Island City Waterways, Round the World Festival and its Performance Art and Learning program (PAL) that serves more than 2000 youth with free cultural arts assemblies each year.
Webster Street in Alameda has long been the host of many arts, crafts and holiday festivals. During some of these festivals, the Chamber of Commerce along with the West Alameda Business Association (WABA) will block off a portion of Webster St. for the entertainment of festival-goers. Festivals such as The Island JAM formerly known as the Peanut Butter Jam Festival bring a lot of local and outside visitors. Other events on the "West End" include Trick-or-Treat on Webster Street where merchants supply goodies for local children and culminate with a parade and costume contest; in December "Santa Claus Meet-n-Greet on Webster Street" happens with elves, and a photo with Santa Claus.
There are three major events when the street in Alameda's historic downtown district is closed to vehicular traffic. The "Park Street Spring Festival" takes place every May during the weekend of Mother's Day and attracts over 50,000 visitors. The "Park Street Art & Wine Faire" takes place the last weekend of every July and attracts over 100,000 visitors. Both street fairs feature over 150 arts & crafts vendors, food vendors, beer and wine pouring, a children's area, and two stages with regional entertainment. The "Park Street Classic Car Show" is held on the second Saturday every October and displays over 400 vintage vehicles.
The annual Sand Castle and Sculpture Contest takes place in June at the Robert Crown Memorial State Beach. The first contest was held in 1967. Participants compete in three different categories: Ages 12 and Under, Ages 13 and Over and Family.
Public primary and secondary education in Alameda is the responsibility of the Alameda Unified School District, which is legally separate from the City of Alameda government (as is common throughout California). The College of Alameda, a two-year community college in the West End is part of the Peralta Community College District. The city has numerous private primary schools, and one private high school, St. Joseph Notre Dame High School, a Catholic school.
Alameda's relationships with Wuxi and Jiangyin were initiated in 2005, in part, by Stewart Chen, who then served on the City of Alameda Social Service and Human Relations board, and who went on to be elected to Alameda City Council in November, 2012.
Wuxi, China, is a so-called friendship city, because the diplomacy organization Sister Cities International does not recognize the relationship.
In September 2013, a Tibetan rights group initiated a social media and e-mail campaign targeting the Mayor of Alameda, complaining that City of Alameda's participation in, and association with, a flag-raising ceremony to recognize National Day of the People's Republic of China on October 1 was tantamount to endorsing the communist regime in China, its human rights abuses, and the occupation of Tibet. The City of Alameda responded that the ceremony was a function of the Alameda Sister City Association and the Alameda Wuxi Friendship Committee, not a function of the City of Alameda. The Tibetan rights group responded that on September 26, the City of Alameda Social Service and Human Relations board appointed a member, Michael Robles-Wong, as a representative to the Sister City Association.
On October 1, 2013, the Tibetan rights groupsTibetTruth and Bay Area Friends of Tibet sent roughly 75 protesters to Alameda City Hall to protest the ceremony, which organizers ultimately canceled before it began. Former City of Alameda Councilmember Frank Matarrese announced the cancellation. Then-city councilmember Stewart Chen subsequently defended the ceremony, as a diplomatic, not political, exercise. | https://en.wikipedia.org/wiki?curid=3052 |
Alpha helix
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located three or four residues earlier along the protein sequence.
The alpha helix is also called a classic Pauling–Corey–Branson α-helix. The name 3.613-helix is also used for this type of helix, denoting the average number of residues per helical turn, with 13 atoms being involved in the ring formed by the hydrogen bond.
Among types of local structure in proteins, the α-helix is the most extreme and the most predictable from sequence, as well as the most prevalent.
In the early 1930s, William Astbury showed that there were drastic changes in the X-ray fiber diffraction of moist wool or hair fibers upon significant stretching. The data suggested that the unstretched fibers had a coiled molecular structure with a characteristic repeat of ≈.
Astbury initially proposed a kinked-chain structure for the fibers. He later joined other researchers (notably the American chemist Maurice Huggins) in proposing that:
Although incorrect in their details, Astbury's models of these forms were correct in essence and correspond to modern elements of secondary structure, the α-helix and the β-strand (Astbury's nomenclature was kept), which were developed by Linus Pauling, Robert Corey and Herman Branson in 1951 (see below); that paper showed both right- and left-handed helices, although in 1960 the crystal structure of myoglobin showed that the right-handed form is the common one. Hans Neurath was the first to show that Astbury's models could not be correct in detail, because they involved clashes of atoms. Neurath's paper and Astbury's data inspired H. S. Taylor, Maurice Huggins and Bragg and collaborators to propose models of keratin that somewhat resemble the modern α-helix.
Two key developments in the modeling of the modern α-helix were: the correct bond geometry, thanks to the crystal structure determinations of amino acids and peptides and Pauling's prediction of "planar" peptide bonds; and his relinquishing of the assumption of an integral number of residues per turn of the helix. The pivotal moment came in the early spring of 1948, when Pauling caught a cold and went to bed. Being bored, he drew a polypeptide chain of roughly correct dimensions on a strip of paper and folded it into a helix, being careful to maintain the planar peptide bonds. After a few attempts, he produced a model with physically plausible hydrogen bonds. Pauling then worked with Corey and Branson to confirm his model before publication. In 1954, Pauling was awarded his first Nobel Prize "for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances" (such as proteins), prominently including the structure of the α-helix.
The amino acids in an α-helix are arranged in a right-handed helical structure where each amino acid residue corresponds to a 100° turn in the helix (i.e., the helix has 3.6 residues per turn), and a translation of along the helical axis. Dunitz describes how Pauling's first article on the theme in fact shows a left-handed helix, the enantiomer of the true structure. Short pieces of left-handed helix sometimes occur with a large content of achiral glycine amino acids, but are unfavorable for the other normal, biological -amino acids. The pitch of the alpha-helix (the vertical distance between consecutive turns of the helix) is , which is the product of 1.5 and 3.6. What is most important is that the N-H group of an amino acid forms a hydrogen bond with the C=O group of the amino acid "four" residues earlier; this repeated "i" + 4 → "i" hydrogen bonding is the most prominent characteristic of an α-helix. Official international nomenclature specifies two ways of defining α-helices, rule 6.2 in terms of repeating "φ", "ψ" torsion angles (see below) and rule 6.3 in terms of the combined pattern of pitch and hydrogen bonding. The α-helices can be identified in protein structure using several computational methods, one of which is DSSP (Define Secondary Structure of Protein).
Similar structures include the 310 helix ("i" + 3 → "i" hydrogen bonding) and the π-helix ("i" + 5 → "i" hydrogen bonding). The α-helix can be described as a 3.613 helix, since the "i" + 4 spacing adds three more atoms to the H-bonded loop compared to the tighter 310 helix, and on average, 3.6 amino acids are involved in one ring of α-helix. The subscripts refer to the number of atoms (including the hydrogen) in the closed loop formed by the hydrogen bond.
Residues in α-helices typically adopt backbone ("φ", "ψ") dihedral angles around (−60°, −45°), as shown in the image at right. In more general terms, they adopt dihedral angles such that the "ψ" dihedral angle of one residue and the "φ" dihedral angle of the "next" residue sum to roughly −105°. As a consequence, α-helical dihedral angles, in general, fall on a diagonal stripe on the Ramachandran diagram (of slope −1), ranging from (−90°, −15°) to (−35°, −70°). For comparison, the sum of the dihedral angles for a 310 helix is roughly −75°, whereas that for the π-helix is roughly −130°. The general formula for the rotation angle "Ω" per residue of any polypeptide helix with "trans" isomers is given by the equation
The α-helix is tightly packed; there is almost no free space within the helix. The amino-acid side-chains are on the outside of the helix, and point roughly "downward" (i.e., toward the N-terminus), like the branches of an evergreen tree (Christmas tree effect). This directionality is sometimes used in preliminary, low-resolution electron-density maps to determine the direction of the protein backbone.
Helices observed in proteins can range from four to over forty residues long, but a typical helix contains about ten amino acids (about three turns). In general, short polypeptides do not exhibit much α-helical structure in solution, since the entropic cost associated with the folding of the polypeptide chain is not compensated for by a sufficient amount of stabilizing interactions. In general, the backbone hydrogen bonds of α-helices are considered slightly weaker than those found in β-sheets, and are readily attacked by the ambient water molecules. However, in more hydrophobic environments such as the plasma membrane, or in the presence of co-solvents such as trifluoroethanol (TFE), or isolated from solvent in the gas phase, oligopeptides readily adopt stable α-helical structure. Furthermore, crosslinks can be incorporated into peptides to conformationally stabilize helical folds. Crosslinks stabilize the helical state by entropically destabilizing the unfolded state and by removing enthalpically stabilized "decoy" folds that compete with the fully helical state. It has been shown that α-helices are more stable, robust to mutations and designable than β-strands in natural proteins, and also in artificial designed proteins.
Since the α-helix is defined by its hydrogen bonds and backbone conformation, the most detailed experimental evidence for α-helical structure comes from atomic-resolution X-ray crystallography such as the example shown at right. It is clear that all the backbone carbonyl oxygens point downward (toward the C-terminus) but splay out slightly, and the H-bonds are approximately parallel to the helix axis. Protein structures from NMR spectroscopy also show helices well, with characteristic observations of nuclear Overhauser effect (NOE) couplings between atoms on adjacent helical turns. In some cases, the individual hydrogen bonds can be observed directly as a small scalar coupling in NMR.
There are several lower-resolution methods for assigning general helical structure. The NMR chemical shifts (in particular of the Cα, Cβ and C′) and residual dipolar couplings are often characteristic of helices. The far-UV (170–250 nm) circular dichroism spectrum of helices is also idiosyncratic, exhibiting a pronounced double minimum at around 208 and 222 nm. Infrared spectroscopy is rarely used, since the α-helical spectrum resembles that of a random coil (although these might be discerned by, e.g., hydrogen-deuterium exchange). Finally, cryo electron microscopy is now capable of discerning individual α-helices within a protein, although their assignment to residues is still an active area of research.
Long homopolymers of amino acids often form helices if soluble. Such long, isolated helices can also be detected by other methods, such as dielectric relaxation, flow birefringence, and measurements of the diffusion constant. In stricter terms, these methods detect only the characteristic prolate (long cigar-like) hydrodynamic shape of a helix, or its large dipole moment.
Different amino-acid sequences have different propensities for forming α-helical structure. Methionine, alanine, leucine, glutamate, and lysine uncharged ("MALEK" in the amino-acid 1-letter codes) all have especially high helix-forming propensities, whereas proline and glycine have poor helix-forming propensities. Proline either breaks or kinks a helix, both because it cannot donate an amide hydrogen bond (having no amide hydrogen), and also because its sidechain interferes sterically with the backbone of the preceding turn inside a helix, this forces a bend of about 30° in the helix's axis. However, proline is often seen as the "first" residue of a helix, it is presumed due to its structural rigidity. At the other extreme, glycine also tends to disrupt helices because its high conformational flexibility makes it entropically expensive to adopt the relatively constrained α-helical structure.
Estimated differences in free energy, Δ(Δ"G"), estimated in kcal/mol per residue in an α-helical configuration, relative to alanine arbitrarily set as zero. Higher numbers (more positive free energies) are less favoured. Significant deviations from these average numbers are possible, depending on the identities of the neighbouring residues.
A helix has an overall dipole moment due to the aggregate effect of the individual microdipoles from the carbonyl groups of the peptide bond pointing along the helix axis. The effects of this macrodipole are a matter of some controversy. α-helices often occur with the N-terminal end bound by a negatively charged group, sometimes an amino acid side chain such as glutamate or aspartate, or sometimes a phosphate ion. Some regard the helix macrodipole as interacting electrostatically with such groups. Others feel that this is misleading and it is more realistic to say that the hydrogen bond potential of the free NH groups at the N-terminus of an α-helix can be satisfied by hydrogen bonding; this can also be regarded as set of interactions between local microdipoles such as .
Coiled-coil α helices are highly stable forms in which two or more helices wrap around each other in a "supercoil" structure. Coiled coils contain a highly characteristic sequence motif known as a heptad repeat, in which the motif repeats itself every seven residues along the sequence ("amino acid" residues, not DNA base-pairs). The first and especially the fourth residues (known as the "a" and "d" positions) are almost always hydrophobic; the fourth residue is typically leucine this gives rise to the name of the structural motif called a "leucine zipper", which is a type of coiled-coil. These hydrophobic residues pack together in the interior of the helix bundle. In general, the fifth and seventh residues (the "e" and "g" positions) have opposing charges and form a salt bridge stabilized by electrostatic interactions. Fibrous proteins such as keratin or the "stalks" of myosin or kinesin often adopt coiled-coil structures, as do several dimerizing proteins. A pair of coiled-coils a four-helix bundle is a very common structural motif in proteins. For example, it occurs in human growth hormone and several varieties of cytochrome. The Rop protein, which promotes plasmid replication in bacteria, is an interesting case in which a single polypeptide forms a coiled-coil and two monomers assemble to form a four-helix bundle.
The amino acids that make up a particular helix can be plotted on a helical wheel, a representation that illustrates the orientations of the constituent amino acids (see the article for leucine zipper for such a diagram). Often in globular proteins, as well as in specialized structures such as coiled-coils and leucine zippers, an α-helix will exhibit two "faces" one containing predominantly hydrophobic amino acids oriented toward the interior of the protein, in the hydrophobic core, and one containing predominantly polar amino acids oriented toward the solvent-exposed surface of the protein.
Changes in binding orientation also occur for facially-organized oligopeptides. This pattern is especially common in antimicrobial peptides, and many models have been devised to describe how this relates to their function. Common to many of them is that the hydrophobic face of the antimicrobial peptide forms pores in the plasma membrane after associating with the fatty chains at the membrane core.
Myoglobin and hemoglobin, the first two proteins whose structures were solved by X-ray crystallography, have very similar folds made up of about 70% α-helix, with the rest being non-repetitive regions, or "loops" that connect the helices. In classifying proteins by their dominant fold, the Structural Classification of Proteins database maintains a large category specifically for all-α proteins.
Hemoglobin then has an even larger-scale quaternary structure, in which the functional oxygen-binding molecule is made up of four subunits.
α-Helices have particular significance in DNA binding motifs, including helix-turn-helix motifs, leucine zipper motifs and zinc finger motifs. This is because of the convenient structural fact that the diameter of an α-helix is about including an average set of sidechains, about the same as the width of the major groove in B-form DNA, and also because coiled-coil (or leucine zipper) dimers of helices can readily position a pair of interaction surfaces to contact the sort of symmetrical repeat common in double-helical DNA. An example of both aspects is the transcription factor Max (see image at left), which uses a helical coiled coil to dimerize, positioning another pair of helices for interaction in two successive turns of the DNA major groove.
α-Helices are also the most common protein structure element that crosses biological membranes (transmembrane protein), it is presumed because the helical structure can satisfy all backbone hydrogen-bonds internally, leaving no polar groups exposed to the membrane if the sidechains are hydrophobic. Proteins are sometimes anchored by a single membrane-spanning helix, sometimes by a pair, and sometimes by a helix bundle, most classically consisting of seven helices arranged up-and-down in a ring such as for rhodopsins (see image at right) or for G protein–coupled receptors (GPCRs).
α-Helices under axial tensile deformation, a characteristic loading condition that appears in many alpha-helix-rich filaments and tissues, results in a characteristic three-phase behavior of stiff-soft-stiff tangent modulus. Phase I corresponds to the small-deformation regime during which the helix is stretched homogeneously, followed by phase II, in which alpha-helical turns break mediated by the rupture of groups of H-bonds. Phase III is typically associated with large-deformation covalent bond stretching.
Alpha-helices in proteins may have low-frequency accordion-like motion as observed by the Raman spectroscopy and analyzed via the quasi-continuum model. Helices not stabilized by tertiary interactions show dynamic behavior, which can be mainly attributed to helix fraying from the ends.
Homopolymers of amino acids (such as polylysine) can adopt α-helical structure at low temperature that is "melted out" at high temperatures. This helix–coil transition was once thought to be analogous to protein denaturation. The statistical mechanics of this transition can be modeled using an elegant transfer matrix method, characterized by two parameters: the propensity to initiate a helix and the propensity to extend a helix.
At least five artists have made explicit reference to the α-helix in their work: Julie Newdoll in painting and Julian Voss-Andreae, Bathsheba Grossman, Byron Rubin, and Mike Tyka in sculpture.
San Francisco area artist Julie Newdoll, who holds a degree in Microbiology with a minor in art, has specialized in paintings inspired by microscopic images and molecules since 1990. Her painting "Rise of the Alpha Helix" (2003) features human figures arranged in an α helical arrangement. According to the artist, "the flowers reflect the various types of sidechains that each amino acid holds out to the world". This same metaphor is also echoed from the scientist's side: "β sheets do not show a stiff repetitious regularity but flow in graceful, twisting curves, and even the α-helix is regular more in the manner of a flower stem, whose branching nodes show the influence of environment, developmental history, and the evolution of each part to match its own idiosyncratic function."
Julian Voss-Andreae is a German-born sculptor with degrees in experimental physics and sculpture. Since 2001 Voss-Andreae creates "protein sculptures" based on protein structure with the α-helix being one of his preferred objects. Voss-Andreae has made α-helix sculptures from diverse materials including bamboo and whole trees. A monument Voss-Andreae created in 2004 to celebrate the memory of Linus Pauling, the discoverer of the α-helix, is fashioned from a large steel beam rearranged in the structure of the α-helix. The , bright-red sculpture stands in front of Pauling's childhood home in Portland, Oregon.
Ribbon diagrams of α-helices are a prominent element in the laser-etched crystal sculptures of protein structures created by artist Bathsheba Grossman, such as those of insulin, hemoglobin, and DNA polymerase. Byron Rubin is a former protein crystallographer now professional sculptor in metal of proteins, nucleic acids, and drug molecules many of which featuring α-helices, such as subtilisin, human growth hormone, and phospholipase A2.
Mike Tyka is a computational biochemist at the University of Washington working with David Baker. Tyka has been making sculptures of protein molecules since 2010 from copper and steel, including ubiquitin and a potassium channel tetramer. | https://en.wikipedia.org/wiki?curid=3054 |
Accrington
Accrington is a town in the Hyndburn borough of Lancashire, England. It lies about east of Blackburn, west of Burnley, east of Preston, north of Manchester city centre and is situated on the mostly culverted River Hyndburn. Commonly abbreviated by locals to "Accy", the town has a population of 35,456 according to the 2011 census.
Accrington is a former centre of the cotton and textile machinery industries. The town is famed for manufacturing the hardest and densest building bricks in the world, "The Accrington NORI" (iron), which were used in the construction of the Empire State Building and for the foundations of Blackpool Tower; famous for Accrington Stanley F.C. and the Haworth Art Gallery which holds Europe's largest collection of Tiffany glass.
The name Accrington appears to be Anglo-Saxon in origin. In the records it variously appears as "Akarinton" in 1194; "Akerunton", "Akerinton" and "Akerynton" in 1258; "Acrinton" in 1292; "Ackryngton" in 1311 and "Acryngton" in 1324.
The name may mean "acorn farmstead" from Anglo-Saxon "æcern" meaning "acorn" and "tun" meaning "farmstead" or "village". The southern part of Accrington, the township of New Accrington, was formerly in the Forest of Blackburnshire and the presence of oak trees may be inferred from local place names like Broad Oak and Oak Hill. The products of oak trees were once an important food for swine and a farmstead may have been named for such produce. Anglo-Saxon "Æcerntun" might become Middle English "Akerenton", "Akerinton" and the like. Also worth considering is that in the Lancashire dialect "acorn" was "akran".
There is no known Old English personal name from which the first element can be derived. But if the Frisian names "Akkrum", "Akkeringa" and Dutch name "Akkerghem", are derived from the personal name "Akker" there may be a corresponding Old English name from which "Accrington" may be derived.
Accrington covers two townships which were established in 1507 following disafforestation; those of Old Accrington and New Accrington which were merged in 1878 with the incorporation of the borough council. There have been settlements there since the medieval period, likely in the Grange Lane and Black Abbey area, and the King's Highway which passes above the town was at one time used by the kings and queens of England when they used the area for hunting when the Forest of Accrington was one of the four forests of the hundred of Blackburnshire.
Robert de Lacy gave the manor of Accrington to the monks of Kirkstall in the 12th century. The monks built a grange there; removing the inhabitants to make room for it. The locals got their revenge by setting fire to the new building, destroying its contents and in the process killing the three lay brothers who occupied it. An area of the town is named 'Black Abbey', a possible reference to the murders. Regardless of whatever happened, Accrington did not remain under monastic control for long before reverting to the de Lacys.
It is thought the monks of Kirkstall may have built a small chapel there during their tenure for the convenience of those in charge residing there and their tenants, but the records are uncertain. What is known is that there was a chapel in Accrington prior to 1553 where the vicar of Whalley was responsible for the maintenance of divine worship. However it did not have its own minister and it was served, when at all, by the curate of one of the adjacent chapels. In 1717 Accrington was served by the curate of Church, who preached there only once a month. St. James's Church was built in 1763, replacing the old chapel however it did not achieve parochial status until as late as 1870.
Until around 1830 visitors considered Accrington to be just a "considerable village". The Industrial Revolution, however, resulted in large changes and Accrington's location on the confluence of a number of streams made it attractive to industry and a number of mills were built in the town in the mid-18th century. Further industrialisation then followed in the late-18th century and local landowners began building mansions in the area on the outskirts of the settlement where their mills were located while their employees lived in overcrowded unsanitary conditions in the centre.
Industrialisation resulted in rapid population growth during the 19th century, as people moved from over North West England to Accrington, with the population increasing from 3,266 in 1811 to 10,376 in 1851 to 43,211 in 1901 to its peak in 1911 at 45,029.
This fast population growth and slow response from the established church allowed non-conformism to flourish in the town. By the mid-19th century there were Wesleyan, Primitive Methodist, United Free Methodist, Congregationalist, Baptist, Swedenborgian, Unitarian, Roman Catholic and Catholic Apostolic churches in the town. The Swedenborgian church was so grand that it was considered to be the ‘Cathedral' of that denomination.
For many decades the textiles industry, the engineering industry and coal mining were the central activities of the town. Cotton mills and dye works provided work for the inhabitants, but often in very difficult conditions. There was regular conflict with employers over wages and working conditions. On 24 April 1826 over 1,000 men and women, many armed, gathered at Whinney Hill in Clayton-le-Moors to listen to a speaker from where they marched on Sykes's Mill at Higher Grange Lane, near the site of the modern police station and magistrates' courts, and smashed over 60 looms. These riots spread from Accrington through Oswaldtwistle, Blackburn, Darwen, Rossendale, Bury and Chorley. In the end after three days of riots 1,139 looms were destroyed, 4 rioters and 2 bystanders shot dead by the authorities in Rossendale and 41 rioters sentenced to death (all of whose sentences were commuted).
In the 1842 'plug riots' a general strike spread from town to town due to conditions in the town. In a population of 9,000 people as few as 100 were fully employed. From 15 August 1842 the situation boiled over and bands of men entered the mills which were running and stopped the machinery by knocking out the boiler plugs. This allowed the water and steam to escape shutting down the mill machinery. Thousands of strikers walked over the hills from one town to another to persuade people to join the strike in civil disturbances that lasted about a week. The strike was associated with the Chartist movement but eventually proved unsuccessful in its aims.
In the early 1860s the Lancashire cotton famine badly affected Accrington, although less so than the wider area due to its more diverse economy, with as many as half of the town's mill employees out of work at one time.
Conditions were such that a Local Board of Health was constituted in 1853 and the town itself incorporated in 1878 allowing the enforcement of local laws to improve the town.
One well-known association the town has is with the 'Accrington Pals', the nickname given to the smallest home town battalion of volunteers formed to fight in the First World War. The Pals battalions were a peculiarity of the 1914-18 war: Lord Kitchener, the Secretary of State for War, believed that it would help recruitment if friends and work-mates from the same town were able to join up and fight together. Strictly speaking, the 'Accrington Pals' battalion is properly known as the '11th East Lancashire Regiment': the nickname is a little misleading, since of the four 250-strong companies that made up the original battalion only one was composed of men from Accrington. The rest volunteered from other east Lancashire towns such as Burnley, Blackburn and Chorley.
The Pals' first day of action, 1 July 1916, took place in Serre, near Montauban in the north of France. It was part of the 'Big Push' (later known as the Battle of the Somme) that was intended to force the German Army into a retreat from the Western Front, a line they had held since late 1914. The German defences in Serre were supposed to have been obliterated by sustained, heavy, British shelling during the preceding week; however, as the battalion advanced it met with fierce resistance. 235 men were killed and a further 350 wounded — more than half of the battalion — within half an hour. Similarly desperate losses were suffered elsewhere on the front, in a disastrous day for the British Army (approximately 19,000 British soldiers were killed in a single day).
Later in the year, the East Lancashire Regiment was rebuilt with new volunteers — in all, 865 Accrington men were killed during World War I. All of these names are recorded on a war memorial, an imposing white stone cenotaph, which stands in Oak Hill Park in the south of the town. The cenotaph also lists the names of 173 local fatalities from World War II. The trenches from which the Accrington Pals advanced on 1 July 1916 are still visible in John Copse west of the village of Serre, and there is a memorial there made of Accrington brick.
After the war and until 1986, Accrington Corporation buses were painted in the regimental colours of red and blue with gold lining. The mudguards were painted black as a sign of mourning. The current Mayor of Accrington is Lance Sergeant Gary Archer of the Scots Guards.
The 2001 census gave the population of Accrington town as 35,200. The figure for the urban area was 71,220, increased from 70,442 in 1991. This total includes Accrington, Church, Clayton-le-Moors, Great Harwood and Oswaldtwistle. For comparison purposes that is approximately the same size as Aylesbury, Carlisle, Guildford or Scunthorpe urban areas.
The 2011 census gave a population of 35,456 for the Accrington built-up area (which includes Huncoat, Baxenden and Rising Bridge in Rossendale). The area in 2001 was listed as , whereas in 2011 it was .
The borough of Hyndburn as a whole has a population of 80,734. This includes Accrington Urban Area and other outlying towns and villages such as; Altham, Rishton, part of Belthorn, and Knuzden and Whitebirk (considered suburbs of Blackburn).
Formerly cotton and textile machinery were important industries in the town. NORIs, a type of iron hard engineering brick, were produced nearby in Huncoat which was closed in 2013, but later reopened in 2015. Mills and factories are Accrington's past but there a few factories and garages which now occupy the old buildings.
The council has a regeneration plan in place, which will, according to the council, boost the local economy. The plan is to upgrade many old shops, and build a bus station. A memorial for the Accrington Pals may be built outside the town hall.
The Hyndburn Borough Council plans to spend £10 million to refurbish the town centre, which includes:
Half of Blackburn Road is being refurbished and is now being made into a more attractive shopping street, upgrading shops, adding more trees, and repaving the pavements.
Two new phases are being built, the first one called the Acorn Park, where new houses are being built with balconies and greener spaces, and Phoenix Place, which will also include new housing and the building of a new mosque.
Accrington is a hill town located at the western edge of the Pennines within a bowl and largely encircled by surrounding hills to heights of 300-400m. The Hyndburn or Accrington Brook flows through the centre of the town. Hill settlements origins were as the economic foci of the district engaging in the spinning and weaving of woolen cloth. Wool, lead and coal were other local industries.
Geographical coordinates: 53° 46' 0" North, 2° 21' 0" West. Height above sea level: there is a spot height outside the Market Hall which is 133.5m; the bench mark on the side of the neighbouring Town Hall is 441.10 feet. The highest height in the town is 320m which is in Baxenden and the lowest is the town hall which is at 132.5m. most of the town is around 200m.
The town has strong local travel links as Accrington railway station lies on the East Lancashire Line serving trains running locally and trains running from Blackpool to York. However, recent changes to the train timetables have been a disservice to Accrington, increasing the journey time to Preston (a vital link to London or Scotland) by up to 1.5 hours. However, there are still buses to Manchester every thirty minutes as well as more frequent services to other towns in east Lancashire. The main road running through the town centre is the A680 running from Rochdale to Whalley. The town is served by junction seven of the M65 and is linked from the A680 and the A56 dual carriageway which briefly merge; linking to the M66 motorway heading towards Manchester. The closest airports are Manchester Airport at , Blackpool Airport at and Leeds Bradford Airport at .
There was once a rail link south to Manchester via Haslingden and Bury, but this was closed in the 1960s as part of cuts following the Beeching Report. The trackbed from Accrington to Baxenden is now a linear treelined cycleway/footpath. A train service to Manchester via the Todmorden Curve opened in 2015. A new bus station is being built in Accrington too.
Bus operators Pilkington Bus and M&M Coaches are based in Accrington, and Holmeswood Coaches, Rosso and Transdev Blazefield subsidiaries Blackburn Bus Company and Burnley Bus Company also provide bus services in the town; routes serve places such as Blackburn, Oswaldtwistle, Rishton, Burnley and Clitheroe. However M&M Coaches ceased business suddenly on 21 September 2016
Accrington Library, on St James Street, is a Carnegie library that opened in 1908. It is noted for its stained glass window designed by Gustav Hiller and as a place of inspiration for the young Jeanette Winterson.
Near the Tesco supermarket, there is Accrington Skate Park which is popular during the school holidays. On Broadway, Accrington Police Station serves the Borough of Hyndburn. In April 2003, Hyndburn Community Fire Station opened, also serving the Borough of Hyndburn.
The town is served by the Lancashire Constabulary Police station on Broadway after moving into town from its previous location on Manchester Road as an effort to save money due to rising expenses and decreasing funding by the government. Crime is very low in Accrington compared to nearby towns.
Policing of the Railway station and railway-owned properties is served by the British Transport Police, nearest post in Preston.
Accrington is represented in parliament as a part of the constituency of Hyndburn. The constituency boundaries do not align exactly with those of the district of the same name.
Accrington was first represented nationally after the Redistribution of Seats Act 1885 after the 1885 general election by Accrington (UK Parliament constituency). This seat was abolished in the 1983 general election and replaced with the present constituency of Hyndburn (UK Parliament constituency).
Accrington became incorporated as a municipal borough in 1878. Under the Local Government Act 1972, since 1974, the town has formed part of the larger Borough of Hyndburn including the former Urban Districts of Oswaldtwistle, Church, Clayton-le-Moors, Great Harwood and Rishton.
Hyndburn consists of 16 wards, electing a total of 35 councillors. Due to its size Accrington is represented by a number of wards in the Borough of Hyndburn. The town largely consists of the Milnshaw, Peel, Central, Barnfield and Spring Hill wards, although some parts of those wards are in other towns in the borough.
The local hospital is Accrington Victoria Hospital however, as it only deals with minor issues, Accident and Emergency is provided by the Royal Blackburn Hospital. Other services are provided at the Accrington Pals Primary Health Care Centre and the Accrington Acorn Primary Health Care Centre.
The chief publications in the area are the weekly "Accrington Observer", part of MEN media, and the "Lancashire Telegraph". Accrington Observer is currently stationed within the Market Hall.
A Ron Hill 10K marathon happens every year at the end of March or start of April and is named for the local Olympic runner for Britain Ron Hill. The marathon goes around town and through the local countrysides, and is organised by the council and local businesses. There is also an annual 1K family run which began in 2014. In 2015 more than five hundred runners ran in the race. Their also a race held by the local rotary around August time.
Accrington Stanley F.C., entered the Football League in 1921 with the formation of the old Third Division (North); after haunting the lower reaches of English football for forty years, they eventually resigned from the League in 1962, due to financial problems, and folded in 1965. The club was reformed three years later and then worked its way through the non-league divisions to reach the Nationwide Conference in 2003. In the 2005–06 season, Stanley, after winning against Woking with three matches to spare, secured a place back in the Football League and the town celebrated with a small parade and honours placed on senior executives of the team. One of the teams relegated—and thus being replaced by Stanley—were Oxford United, who were voted into the Football League to replace the previous Accrington Stanley. The football stadium is called the Crown Ground. Until the 2012–13 season, when Fleetwood Town entered the league, Accrington was the smallest town in England and Wales with a Football League club.
Accrington Stanley Football Club has had its own pub in the town, the Crown, since July 2007.
An earlier club, Accrington F.C., were one of the twelve founder members of the Football League in 1888. However, their time in league football was even less successful and considerably briefer than that of Accrington Stanley: they dropped out of the league in 1893 and folded shortly afterwards due to financial problems. The town of Accrington thus has the unique "distinction" of having lost two separate clubs from league football. They are currently placed in EFL League One after winning the EFL League Two title in the 2017/18 season.
Accrington Cricket Club plays at Thorneyholme Road in the Lancashire League. Cricket is also played in parks. Schools nearby have shown major interest in cricket and have held cricket training and tournaments.
Accrington has a golf course.
There are many gyms in the town and the council has held fitness classes for the women and old people. There are two sports centres, the main on being the Hyndburn Sports Centre, Which recently renovated their swimming pool area. near Lidl.
Accrington has the following primary schools:
The secondary schools serving Accrington are:
All the secondary schools compete each other to achieve better results which resulted in the Hollins Technology College winning an award from SSAT for fantastic progress. The Hollins is also within the top 3% In the country and well known for its development.
The college in the town centre is Accrington and Rossendale College; nearby universities include University Centre at Blackburn College, and the University of Central Lancashire in Preston. There is also a library near the town centre where books and internet are available.
The Haworth Art Gallery was previously a mansion named as Hollins Hill Mansion. The museum houses a collection of Tiffany glassware presented to the town by Joseph Briggs, an Accrington man who had joined Tiffany's in the late 19th century and eventually became art director and assistant manager.It is situated in Haworth Park on Manchester Road.
The Viaduct is a bridge which has a railway line on it, it goes through the town and has many storage units and shop on sale by National Rail. The Viaduct ends at the Accrington Eco Station.
The Accrington Town Hall was built in the 19th century and is also listed. It has a reception rooms where pantomimes and fitness clubs are held. Weddings could also be held there. The town hall is on Blackburn Road near The Arcade.
The Arcade is a Victorian shopping Centre with about 10-15 outlets and has many restaurants there. It is on Church street near the town hall. The arcade has hardware shops and shops like Argos. There are some restaurants in there too. Sadly most outlets are closing since the year 2013. In 2016, there was a revamp of the Arcade which saw specialist shops such as Darts, Vinyl and Knitted Wear added into the Arcade.
Oakhill Park is a large and old park with a sceneric view of Accrington. It has won many awards such as the best park in Lancashire It has also been awarded an Eco Award. The Haworth Art Gallery is in the park. It is on Manchester Road.
Peel Park is a park in Accrington which was opened by William Peel on 29 September 1909. The Coppice is a hill within the park, and provides a 2.2 mile scenic walk around the park. There was a centenary celebration marking 100 years from the Coppice being handed over to the people of Accrington on 26 September 2009. There was also a refurbishment of the paths and monument at the top of the Coppice at this time. Since then there has been several revamps to the Playground area of the park. | https://en.wikipedia.org/wiki?curid=3055 |
Armageddon
According to the Book of Revelation in the New Testament of the Christian Bible, Armageddon (, from "Harmagedōn", Late Latin: , from Hebrew: Har Megiddo) is the prophesied location of a gathering of armies for a battle during the end times, variously interpreted as either a literal or a symbolic location. The term is also used in a generic sense to refer to any end of the world scenario. In Islamic theology, the Armageddon is also mentioned in Hadith as the Greatest Armageddon or Al-Malhama Al-Kubra (the great battle).
The "mount" of Megiddo in northern Israel is not actually a mountain, but a tell (a mound or hill created by many generations of people living and rebuilding on the same spot) on which ancient forts were built to guard the Via Maris, an ancient trade route linking Egypt with the northern empires of Syria, Anatolia and Mesopotamia. Megiddo was the location of various ancient battles, including one in the 15th century BC and one in 609 BC. The nearby modern Megiddo is a kibbutz in the Kishon River area.
The word "Armageddon" appears only once in the Greek New Testament, in . The word is transliterated to Greek from Hebrew "har məgiddô" (), "har" (Strong H2022) meaning "a mountain or range of hills (sometimes used figuratively): - hill (country), mount (-ain), X promotion." This is a shortened form of "harar" (Strong H2042) "to loom up; a mountain; -hill, mount". "Megiddo" (Strong מְגִדּוֹן H4023) /meg-id-do'/ "Megiddon or Megiddo, a place of crowds.") The name refers to a fortification made by King Ahab (869–850 BC) that dominated the Plain of Jezreel.
Megiddo is mentioned twelve times in the Old Testament, ten times in reference to the ancient city of Megiddo, and twice with reference to "the plain of Megiddo", most probably simply meaning "the plain next to the city". None of these Old Testament passages describes the city of Megiddo as being associated with any particular prophetic beliefs. The one New Testament reference to the city of Armageddon found in also makes no specific mention of any armies being predicted to one day gather in this city, but instead seems to predict only that "they (will gather) the kings together to ... Armageddon". The text does however seem to imply, based on the text from the earlier passage of Revelation 16:14, that the purpose of this gathering of kings in the "place called Armageddon" is "for the war of the great day of God, the Almighty." Because of the seemingly highly symbolic and even cryptic language of this one New Testament passage, some Christian scholars conclude that Mount Armageddon must be an idealized location. R. J. Rushdoony says, "There are no mountains of Megiddo, only the Plains of Megiddo. This is a deliberate destruction of the vision of any literal reference to the place." Other scholars, including C. C. Torrey, Kline and Jordan argue that the word is derived from the Hebrew "moed" (), meaning "assembly". Thus, "Armageddon" would mean "Mountain of Assembly," which Jordan says is "a reference to the assembly at Mount Sinai, and to its replacement, Mount Zion."
Most traditions interpret this Bible prophecy to be symbolic of the progression of the world toward the "great day of God, the Almighty" in which God pours out their just and holy wrath against unrepentant sinners, led by Satan, in a literal end-of-the-world final confrontation. Armageddon is the symbolic name given to this event based on scripture references regarding divine obliteration of God's enemies. The hermeneutical method supports this position by referencing Judges 4 and 5 where God miraculously destroys the enemy of their elect, Israel, at Megiddo.
The location of the eschatological battle on a mountain is significant, “for the mountain is spatially the boundary between heaven and earth and thus a fitting location for the climactic battle between good and evil, God and Satan, Christ and counterfeit Christ.” It is a symbolic place “for the last resistance of anti-god forces prior to the kingdom of Christ”--a battle that is not described in Revelation 16, for it was already won on the cross.
Christian scholar William Hendriksen writes:
In his discussion of Armageddon, J. Dwight Pentecost has devoted a chapter to the subject, "The Campaign of Armageddon", in which he discusses it as a campaign and not a specific battle, which will be fought in the Middle East. Pentecost writes:
Pentecost then discusses the location of this campaign, and mentions the "hill of Megiddo" and other geographic locations such as "the valley of Jehoshaphat" and "the valley of the passengers", "Lord coming from Edom or Idumea, south of Jerusalem, when he returns from the judgment"; and Jerusalem itself.
Pentecost further describes the area involved:
Pentecost then outlines the biblical time period for this campaign to occur and with further arguments concludes that it must take place with the 70th week of Daniel. The invasion of Israel by the Northern Confederacy "will bring the Beast and his armies to the defense of Israel as her protector". He then uses Daniel to further clarify his thinking: (Dan. 11:40b-45).
Again, events are listed by Pentecost in his book:
After the destruction of the Beast at the Second Coming of Jesus, the promised Kingdom is set up, in which Jesus and the saints will rule for a thousand years. Satan is then loosed "for a season" and goes out to deceive the nations, specifically, Gog and Magog. The army mentioned attacks the saints in the New Jerusalem, they are defeated by a judgment of fire coming down from heaven, and then comes the Great White Throne judgment, which includes all of those through the ages and these are cast into the Lake of Fire, which event is also known as the "second death" and Gehenna, not to be confused with Hell, which is Satan's domain. Pentecost describes this as follows:
Jehovah's Witnesses believe that Armageddon is the means by which God will fulfill his purpose for the Earth to be populated with happy healthy humans who will be free from sin and death. They teach that the armies of heaven will eradicate all who oppose the Kingdom of God, wiping out all wicked humans on Earth, only leaving righteous mankind.
They believe that the gathering of all of the nations of the earth refers to the uniting of the world's political powers, as a gradual process which began in 1914 and was later seen in manifestations such as the League of Nations and the United Nations following the First and Second World Wars. These political powers are said to be influenced by Satan and his demons in opposition to God's kingdom. Babylon the Great is interpreted as being the world empire of false religions, and it will be destroyed by the beast just prior to Armageddon. Witnesses believe that after all other religions have been destroyed, the governments of the world will begin persecuting Witnesses, and God will then intervene, precipitating Armageddon.
Jehovah's Witnesses teach that the armies of heaven, led by Jesus, will then destroy all forms of human government and then Jesus, along with a selected 144,000 humans, will rule Earth for 1,000 years. They believe that Satan and his demons will be bound for that period, unable to influence mankind. After the 1,000 years are ended, and the second resurrection has taken place, Satan is released and allowed to tempt the perfect human race one last time. Those who follow Satan will be destroyed, along with him, leaving the earth, and humankind at peace with God forever, free from sin and death.
The religion's current teaching on Armageddon originated in 1925 with former Watch Tower Society president J. F. Rutherford, who based his interpretations on passages that are found in the books of Exodus, Jeremiah, Ezekiel and Psalms as well as additional passages that are found in the books of Samuel, Kings and Chronicles. The doctrine marked a further break from the teachings of the Watch Tower Society's founder Charles Taze Russell, who for decades had taught that the final war would be an anarchistic struggle for domination on earth. Tony Wills, the author of a historical study of Jehovah's Witnesses, wrote that Rutherford seemed to relish his descriptions of how completely the wicked would be destroyed at Armageddon, dwelling at great length on prophecies of destruction. He stated that towards the close of his ministry, Rutherford allocated about half the space that was available in "The Watchtower" magazines to discussions about Armageddon.
The teachings of the Seventh-day Adventist Church state that the terms "Armageddon", "Day of the Lord" and "The Second Coming of Christ" all describe the same event. Seventh-day Adventists further teach that the current religious movements taking place in the world are setting the stage for Armageddon, and they are concerned by an anticipated unity between spiritualism, American Protestantism and Roman Catholicism. A further significant difference in Seventh-day Adventist theology is the teaching that the events of Armageddon will leave the earth desolate for the duration of the millennium. They teach that the righteous will be taken to heaven while the rest of humanity will be destroyed, leaving Satan with no one to tempt and effectively "bound." The final re-creation of a "new heaven and a new earth." then follows the millennium.
For Christadelphians, Armageddon marks the "great climax of history when the nations would be gathered together 'into a place called in the Hebrew tongue Armageddon', and the judgment on them would herald the setting up of the Kingdom of God."
From Bahá'í literature a number of interpretations of the expectations surrounding the Battle of Armageddon may be inferred, three of them being associated with events surrounding the World Wars.
The first interpretation deals with a series of tablets written by Bahá'u'lláh, founder of the Bahá'í Faith, to be sent to various kings and rulers. The second, and best-known one, relates to events near the end of World War I involving General Allenby and the Battle of Megiddo (1918) wherein World Powers are said to have drawn soldiers from many parts of the world to engage in battle at Megiddo. In winning this battle Allenby also prevented the Ottomans from killing 'Abdu'l-Baha, then head of the Baha'i Faith, whom they had intended to crucify. A third interpretation reviews the overall progress of the World Wars, and the situation in the world before and after. | https://en.wikipedia.org/wiki?curid=3058 |
Athlon
Athlon is the brand name applied to a series of x86-compatible microprocessors designed and manufactured by Advanced Micro Devices (AMD). The original Athlon (now called Athlon Classic) was the first seventh-generation x86 processor and was the first desktop processor to reach speeds of one gigahertz (GHz). It made its debut on June 23, 1999. Over the years AMD has used the Athlon name with the 64-bit Athlon 64 architecture, the Athlon II, and Accelerated Processing Unit (APU) chips targeting the Socket AM1 desktop SoC architecture, and Socket AM4 Zen microarchitecture. The modern Zen-based Athlon with a Radeon Graphics processor was introduced in 2019 as AMD’s highest-performance entry-level processor.
Athlon comes from the Ancient Greek ("athlon") meaning "(sport) contest", or "prize of a contest", or "place of a contest; arena". With the Athlon name originally used for AMD's mid-range processors, AMD currently uses Athlon for budget APUs.
AMD founder (and then-CEO) Jerry Sanders aggressively pursued strategic partnerships and engineering talent in the late 1990s, to build on earlier successes in the PC market with the AMD K6 line of processors. One major partnership announced in 1998 paired AMD with semiconductor giant Motorola to co-develop copper-based semiconductor technology, and resulted with the K7 project being the first commercial processor to utilize copper fabrication technology. In the announcement, Sanders referred to the partnership as creating a "virtual gorilla" that would enable AMD to compete with Intel on fabrication capacity while limiting AMD's financial outlay for new facilities.
The K7 design team was led by Dirk Meyer, who had worked as a lead engineer at DEC on multiple Alpha microprocessors during his employment at DEC. When DEC was sold to Compaq in 1998, the company discontinued Alpha processor development. Sanders approached many of the Alpha engineering staff as Compaq/DEC wound down their semiconductor business, and was able to bring in nearly all of the Alpha design team. The K7 engineering design team thus now consisted of both the previously acquired NexGen K6 team (already including engineers such as Vinod Dham) and the nearly complete Alpha design team.
In August 1999, AMD released the Athlon (K7) processor.
By working with Motorola, AMD was able to refine copper interconnect manufacturing to the production stage about one year before Intel. The revised process permitted 180-nanometer processor production. The accompanying die-shrink resulted in lower power consumption, permitting AMD to increase Athlon clock speeds to the 1 GHz range. Yields on the new process exceeded expectations, permitting AMD to deliver high speed chips in volume in March 2000.
The Athlon architecture also used the EV6 bus licensed from DEC as its main system bus. Intel required licensing to use the GTL+ bus used by its Slot 1 Pentium II and later processors. By licensing the EV6 bus used by the Alpha line of processors from DEC, AMD was able to develop its own chipsets and motherboards, and avoid being dependent on licensing from its direct competitor.
While the Athlon name was eventually repurposed for combined CPU/GPU processors with the GPU disabled, after the 2007 launch of the Phenom processors, the name was also used for mid-range processors, positioned above Sempron.
A USD$55 low-power Athlon 200GE with a Radeon graphics processor was introduced in September 2018, sitting under the Ryzen 3 2200G. With the release, AMD began using the Athlon brand name to refer to "low cost, high volume products," in a situation similar to both Intel's Celeron and Pentium Gold. The modern Athlon 3000G was introduced in 2019, and was positioned as AMD’s highest-performance entry-level processor.
Like the AMD K5 and K6, the Athlon dynamically buffers internal micro-instructions at runtime resulting from parallel x86 instruction decoding. The CPU is an out-of-order design, again like previous post-5x86 AMD CPUs. The Athlon utilizes the Alpha 21264's EV6 bus architecture with double data rate (DDR) technology. This means that at 100 MHz, the Athlon front side bus actually transfers at a rate similar to a 200 MHz single data rate bus (referred to as 200 MT/s), which was superior to the method used on Intel's Pentium III (with SDR bus speeds of 100 MHz and 133 MHz).
AMD designed the CPU with more robust x86 instruction decoding capabilities than that of K6, to enhance its ability to keep more data in-flight at once. The Athlon's three decoders could potentially decode three x86 instructions to six microinstructions per clock, although this was somewhat unlikely in real-world use. The critical branch predictor unit, essential to keeping the pipeline busy, was enhanced compared to what was on board the K6. Deeper pipelining with more stages allowed higher clock speeds to be attained. Whereas the AMD K6-III+ topped out at 570 MHz due to its short pipeline, even when built on the 180 nm process, the Athlon was capable of clocking much higher.
AMD ended its long-time handicap with floating point x87 performance by designing a super-pipelined, out-of-order, triple-issue floating point unit. Each of its three units was tailored to be able to calculate an optimal type of instructions with some redundancy. By having separate units, it was possible to operate on more than one floating point instruction at once. This FPU was a huge step forward for AMD. While the K6 FPU had looked anemic compared to the Intel P6 FPU, with Athlon this was no longer the case.
The 3DNow! floating point SIMD technology, again present, received some revisions and a name change to "Enhanced 3DNow!". Additions included DSP instructions and an implementation of the extended MMX subset of Intel SSE.
The Athlon's CPU cache consisted of the typical two levels. Athlon was the first x86 processor with a 128 KB split level 1 cache; a 2-way associative cache separated into 2×64 KB for data and instructions (a concept from Harvard architecture). This cache was double the size of K6's already large 2×32 KB cache, and quadruple the size of Pentium II and III's 2×16 KB L1 cache. The initial Athlon (Slot A, later called Athlon Classic) used 512 KB of level 2 cache separate from the CPU, on the processor cartridge board, running at 50% to 33% of core speed. This was done because the 250 nm manufacturing process was too large to allow for on-die cache while maintaining cost-effective die size. Later Athlon CPUs, afforded greater transistor budgets by smaller 180 nm and 130 nm process nodes, moved to on-die L2 cache at full CPU clock speed.
The AMD Athlon processor launched on June 23, 1999, with general availability by August '99. It launched at 500 MHz and was, on average, 10% faster than the Pentium III at the same clock for Business applications, and even faster (~20%) for gaming workloads.
The Athlon Classic is a cartridge-based processor, named Slot A and similar to Intel's cartridge Slot 1 used for Pentium II and Pentium III. It used the same, commonly available, physical 242 pin connector used by Intel Slot 1 processors but rotated by 180 degrees to connect the processor to the motherboard. The reversal served to make the slot keyed to prevent installation of the wrong CPU, as the Athlon and Intel processors used fundamentally different (and incompatible) signaling standards for their front-side bus. The cartridge assembly allowed the use of higher speed cache memory modules than could be put on (or reasonably bundled with) motherboards at the time. Similar to the Pentium II and the Katmai-based Pentium III, the Athlon Classic contained 512 KB of L2 cache. This high-speed SRAM cache was run at a divisor of the processor clock and was accessed via its own 64-bit bus, known as a "back-side bus" allowing the processor to both service system front side bus requests (the rest of the system) and cache accesses simultaneously versus the traditional approach of pushing "everything" through the front-side bus.
One limitation (also afflicting the Intel Pentium III) is that SRAM cache designs at the time were incapable of keeping up with the Athlon's clock scalability, due both to manufacturing limitations of the cache chips and the difficulty of routing electrical connections to the cache chips themselves. It became increasingly difficult to reliably run an external processor cache to match the processor speeds being released—and in fact it became impossible. Thus initially the Level 2 cache ran at half of the CPU clock speed up to 700 MHz (350 MHz cache). Faster Slot-A processors had to compromise further and run at 2/5 (up to 850 MHz, 340 MHz cache) or 1/3 (up to 1 GHz, 333 MHz cache). This later race to 1 GHz (1000 MHz) by AMD and Intel further exacerbated this bottleneck as ever higher speed processors demonstrated decreasing gains in overall performance—stagnant SRAM cache memory speeds choked further improvements in overall speed. This directly lead to the development of integrating L2 cache onto the processor itself and remove the dependence on external cache chips. AMD's integration of the cache onto the Athlon processor itself would later result in the Athlon Thunderbird.
The Slot-A Athlons were the first multiplier-locked CPUs from AMD. This was partly done to hinder CPU remarking being done by questionable resellers around the globe. AMD's older CPUs could simply be set to run at whatever clock speed the user chose on the motherboard, making it trivial to relabel a CPU and sell it as a faster grade than it was originally intended. These relabeled CPUs were not always stable, being overclocked and not tested properly, and this was damaging to AMD's reputation. Although the Athlon was multiplier locked, crafty enthusiasts eventually discovered that a connector on the PCB of the cartridge could control the multiplier. Eventually a product called the "Goldfingers device" was created that could unlock the CPU, named after the gold connector pads on the processor board that it attached to.
In commercial terms, the Athlon "Classic" was an enormous success—not just because of its own merits, but also because Intel endured a series of major production, design, and quality control issues at this time. In particular, Intel's transition to the 180 nm production process, starting in late 1999 and running through to mid-2000, suffered delays. There was a shortage of Pentium III parts. In contrast, AMD enjoyed a remarkably smooth process transition and had ample supplies available, causing Athlon sales to become quite strong.
The Argon-based Athlon contained 22 million transistors and measured 184 mm2. It was fabricated by AMD in a slightly modified version of their CS44E process, a 0.25 μm complementary metal–oxide–semiconductor (CMOS) process with six levels of aluminium interconnect. "Pluto" and "Orion" Athlons were fabricated in a 0.18 μm process.
The second generation Athlon, the "Thunderbird", debuted on June 5, 2000. This version of the Athlon shipped in a more traditional pin-grid array (PGA) format that plugged into a socket ("Socket A") on the motherboard (it also shipped in the slot A package). It was sold at speeds ranging from 600 MHz to 1.4 GHz (Athlon Classics using the Slot A package could clock up to 1 GHz). The major difference, however, was cache design. Just as Intel had done when they replaced the old Katmai-based Pentium III with the much faster Coppermine-based Pentium III, AMD replaced the 512 KB external reduced-speed cache of the Athlon Classic with 256 KB of on-chip, full-speed exclusive cache. As a general rule, more cache improves performance, but faster cache improves it further still.
AMD changed cache design significantly with the Thunderbird core. With the older Athlon CPUs, the CPU caching was of an inclusive design where data from the L1 is duplicated in the L2 cache. Thunderbird moved to an exclusive design where the L1 cache's contents are not duplicated in the L2. This increases total cache size of the processor and effectively makes caching behave as if there is a very large L1 cache with a slower region (the L2) and a very fast region (the L1). Because of Athlon's very large L1 cache and the exclusive design, which turns the L2 cache into basically a "victim cache", the need for high L2 performance and size was lessened. AMD kept the 64-bit L2 cache data bus from the older Athlons, as a result, and allowed it to have a relatively high latency. A simpler L2 cache reduced the possibility of the L2 cache causing clock scaling and yield issues. Still, instead of the 2-way associative scheme used in older Athlons, Thunderbird did move to a more efficient 16-way associative layout.
The Thunderbird was AMD's most successful product since the Am386DX-40 ten years earlier. Mainboard designs had improved considerably by this time, and the initial trickle of Athlon mainboard makers had swollen to include every major manufacturer. AMD's new fab in Dresden came online, allowing further production increases, and the process technology was improved by a switch to copper interconnects. In October 2000, the Athlon "C" was introduced, raising the mainboard front-side bus speed from 100 MHz to 133 MHz (266 MT/s) and providing roughly 10% extra performance per clock over the "B" model Thunderbird.
AMD released the third-generation Athlon, code-named "Palomino", on October 9, 2001 as the "Athlon XP". The "XP" suffix is interpreted to mean "extended performance" and also as an unofficial reference to Microsoft Windows XP. The "Athlon XP" was marketed using a PR system, which compared its relative performance to an Athlon utilizing the earlier "Thunderbird" core. "Athlon XP" launched at speeds between 1.33 GHz (PR1500+) and 1.53 GHz (PR1800+), giving AMD the x86 performance lead with the 1800+ model. Less than a month later, it enhanced that lead with the release of the 1600 MHz 1900+, and subsequent 1.67 GHz Athlon XP 2000+ in January 2002.
Palomino was the first K7 core to include the full SSE instruction set from the Intel Pentium III, as well as AMD's 3DNow! Professional. It is roughly 10% faster than Thunderbird at the same clock speed, thanks in part to the new SIMD functionality and to several additional improvements. The core has enhancements to the K7's TLB architecture and added a hardware data prefetch mechanism to take better advantage of available memory bandwidth. Palomino was also the first socketed Athlon officially supporting dual processing, with chips certified for that purpose branded as the Athlon MP. According to articles posted on HardwareZone, it was possible to mod the Athlon XP to function as an MP by connecting some fuses on the OPGA, although results varied with the motherboard used.
Changes in core layout also resulted in Palomino being more frugal with its electrical demands, consuming approximately 20% less power than its predecessor, and thus reducing heat output comparatively as well. While the preceding Athlon "Thunderbird" was capable of clock speeds exceeding 1400 MHz, the power and thermal considerations required to reach those speeds would have made it increasingly impractical as a marketable product. Thus, Palomino's goals of lowered power consumption (and resultant heat produced) allowed AMD to increase performance within a reasonable power envelope. Palomino's design also allowed AMD to continue using the same 180 nm manufacturing process node and core voltages as Thunderbird.
The Palomino core debuted earlier in the mobile market—branded as Mobile Athlon 4 with the codename "Corvette". It distinctively used a ceramic interposer much like the Thunderbird instead of the organic pin grid array package used on all later Palomino processors.
The fourth-generation of Athlon was introduced with the "Thoroughbred" core, and was released on June 10, 2002 at 1.8 GHz (Athlon XP PR2200+). The "Thoroughbred" core marked AMD's first production 130 nm silicon, and gave a significant reduction in die size compared to its 180 nm predecessor.
There came to be two steppings (revisions) of this core commonly referred to as Tbred-A (cpuid:6 8 0) and Tbred-B (cpuid:6 8 1). The initial version (later distinguished as A) was mostly a direct die shrink of the preceding Palomino core with minimal design changes, and demonstrated that AMD had successfully transitioned to a 130 nm process with production ready yields. However, while successful in reducing the production cost per processor, the unmodified Palomino design did not demonstrate the expected reduction in heat and clock scalability usually seen when a processor design is moved to a smaller process. As a result, AMD was not able to increase Thoroughbred-A clock speeds much above those of the Palomino it was meant to replace. Tbred-A was only sold in versions from 1333 MHz to 1800 MHz, and mostly only to displace existing speeds of the more production-costly Palomino from AMD's lineup.
AMD thus reworked the Thoroughbred's design to better match the process node on which it was produced, creating a revised core that then became known as Thoroughbred-B. A significant aspect of this redesign was the addition of a ninth "metal layer" to the already quite complex eight-layered Thoroughbred-A. For comparison, the competing Pentium 4 Northwood only utilized six, and its successor Prescott seven layers. While the addition of more layers itself does not improve performance, it gives more flexibility for chip designers routing electrical pathways within a chip, and importantly for the Thoroughbred core, more flexibility in working around logic and power bottlenecks preventing the processor from attaining higher clock speeds. The resulting Tbred-B offered a startling improvement in headroom over the Tbred-A, which made it very popular for overclocking. The Tbred-A often struggled to reach clock speeds above 1.9 GHz, while the Tbred-B often could easily reach 2.3 GHz and above.
The Thoroughbred line received an increased front side bus clock during its lifetime, from 133 MHz (266 MT/s) to 166 MHz (333 MT/s) improving the processor's ability to access memory and I/O efficiency, and resulted in improved per-clock performance. AMD shifted their PR rating scheme accordingly, making lower clock speeds equate to higher PR ratings.
The Thoroughbred-B was the "direct" basis for its successor—the Tbred-B with an "additional" 256 KB of L2 cache (for 512 KB total) became the Barton core.
Fifth-generation Athlon "Barton"-core processors released in early 2003 with PR of 2500+, 2600+, 2800+, 3000+, and 3200+. While not operating at higher clock rates than "Thoroughbred"-core processors, they were marked with higher PR by featuring an increased 512 KB L2 cache; later models additionally supported an increased 200 MHz (400 MT/s) front side bus. The "Thorton" core was a later variant of the "Barton" with half of the L2 cache disabled, and thus was functionally identical to the "Thoroughbred-B" core. The name "Thorton" is a portmanteau of "Thoroughbred" and "Barton".
By the time of Barton's release, the "Northwood"-based Pentium 4 had become more than competitive with AMD's processors. Unfortunately for AMD, a simple increase in size of the L2 cache to 512 KB did not have nearly the same impact as it did for Intel's Pentium 4 line, as the Athlon architecture was not nearly as cache-constrained as the Pentium 4. The Athlon's exclusive-cache architecture and shorter pipeline made it less sensitive to L2 cache size, and the Barton only saw an increase of several percent gained in per-clock performance over the Thoroughbred-B it was derived from. While the increased performance was welcome, it was not sufficient to overtake the Pentium 4 line in overall performance. The PR also became somewhat inaccurate because some Barton models with lower clock rates were being given higher PR than higher-clocked Thoroughbred processors. Instances where a computational task did not benefit more from the additional cache to make up for the loss in raw clock speed created situations where a lower rated (but faster clocked) Thoroughbred would outperform a higher-rated (but lower clocked) Barton.
The Barton was also used to officially introduce a higher 400 MT/s bus clock for the Socket A platform, which was used to gain some Barton models more efficiency (and increased PR). However, it was clear by this time that Intel's quad-pumped bus was scaling well above AMD's double-pumped EV6 bus. The 800 MT/s bus used by many later Pentium 4 processors was well out of the Athlon XP's reach. In order to reach the same bandwidth levels, the Athlon XP's bus would have to be clocked at levels simply unreachable.
By this point, the four-year-old Athlon EV6 bus architecture had scaled to its limit. To maintain or exceed the performance of Intel's newer processors would require a significant redesign. The K7 derived Athlons were replaced in September 2003 by the Athlon 64 family, which featured an on-chip memory controller and a completely new HyperTransport bus to replace EV6.
"Barton (130 nm)"
"Thorton (130 nm)"
A Mobile Athlon XPs ("Athlon XP-M") using a given core is physically identical to the equivalent desktop Athlon XPs counterpart, only differing by the configuration used to achieve a given performance level. Processors are usually binned and selected to become a mobile processor by their ability run a given processor speed while supplied with a lower (than desktop) voltage. This results in lower power consumption, longer battery life, and reduced heat over using a normal desktop part. Additionally Mobile XPs feature not being multiplier-locked and generally higher-rated maximum operating temperatures, requirements intended for better operation within the tight thermal constraints within a notebook PC—but also making them attractive for overclocking.
The Athlon XP-M replaced the older Mobile Athlon 4 based on the "Palomino" core, with the Athlon XP-M using the newer "Thoroughbred" and "Barton" cores. The Athlon XP-M was also offered in a compact microPGA socket 563 version for space constrained applications as an alternative to the larger Socket A.
Like their mobile K6-2+/III+ predecessors, the CPUs were capable of dynamic clock adjustment for power optimization, and also was the reason for the unlocked multiplier. When the system is idle, the CPU clocks itself down via lower bus multiplier and selects a lower voltage. When a program demands more computational resources, the CPU quickly (there is some latency) returns to an intermediate or maximum speed with appropriate voltage to meet the demand. This technology was marketed as "PowerNow!" and was similar to Intel's SpeedStep power saving technique. The feature was controlled by the CPU, motherboard BIOS, and operating system. AMD later renamed the technology to Cool'n'Quiet on their K8-based CPUs (Athlon 64, etc.), and introduced it for use on desktop PCs as well.
Athlon XP-Ms were popular with desktop overclockers, as well as underclockers. The lower voltage requirement and higher heat rating selected CPUs that were essentially "cherry picked" from the manufacturing line. Being some of the best cores "off the line", these CPUs typically overclocked more reliably than their desktop-headed counterparts. Also, the fact that they were not locked to a single multiplier was a significant simplification in the overclocking process. Some "Barton" core Athlon XP-Ms have been successfully overclocked as high as 3.1 GHz.
The chips were also liked for their undervolting ability. Undervolting is a process of determining the lowest voltage at which a CPU can remain stable at a given clock speed. As Athlon XP-M CPUs were already rated running lower voltages than their desktop siblings, it was a better starting point for lowering voltage even further. A popular application was use in home theater PC systems due to high performance and low heat output resultant from low Vcore settings.
Besides not being multiplier locked, XP-Ms curiously were not disabled from multi processor operation. Thus they could be used in place of the more expensive Athlon MP in dual Socket A motherboards. Since those boards generally lacked multiplier and voltage adjustment, and normally only supported 133 MHz FSB, adjustments would still be needed for full speed operation. One method of modification known as wire-modding involves connecting the appropriate CPU pins on the CPU socket with small lengths of wire to select the appropriate multiplier. A typical overclock of a mobile 2500+ CPU to 2.26 GHz with 17x multiplier would result in being faster than highest official 2800+ MP CPU running at 2.13 GHz.
The Zen-based Athlon with Radeon graphics processors was launched in September 2018 with the Athlon 200GE.
On November 19, 2019, AMD released the Athlon 3000G, with a higher 3.5 GHz core clock and 1100MHz graphics clock compared to the Athlon 200GE also with two cores. The main functional difference between the 200GE was the Athlon 3000G’s unlocked multiplier.
Specifications "(see Zen desktop APUs for more details"
"Raven Ridge" (14 nm), "Picasso" (12nm)
The fastest supercomputers based on Athlon MP: | https://en.wikipedia.org/wiki?curid=3060 |
Amu Darya
The Amu Darya (also called the Amu, Amo River, or Amudaryo, and historically known by its Latin name or Greek ) is a major river in Central Asia and Afghanistan. Rising in the Pamir Mountains, north of the Hindu Kush, the Amu Darya is formed by the junction of the Vakhsh and Panj rivers, in the Tigrovaya Balka Nature Reserve on the border between Afghanistan and Tajikistan, and flows from there north-westwards into the southern remnants of the Aral Sea. In its upper course, the river forms part of Afghanistan's northern border with Tajikistan, Uzbekistan, and Turkmenistan. In ancient history, the river was regarded as the boundary of Greater Iran with "Turan", which roughly corresponded to present-day Central Asia.
In classical antiquity, the river was known as the in Latin and () in Greek — a clear derivative of Vakhsh, the name of the largest tributary of the river. In Vedic Sanskrit, the river is also referred to as (). The Brahmanda Purana refers to the river as . The Avestan texts too refer to the River as Yakhsha/Vakhsha (and Yakhsha Arta ("upper Yakhsha") referring to the Jaxartes/Syr Darya twin river to Amu Darya). In Middle Persian sources of the Sassanid period the river is known as (lit. 'good river').
The name "Amu" is said to have come from the medieval city of "Āmul", (later, Chahar Joy/Charjunow, and now known as Türkmenabat), in modern Turkmenistan, with "Darya" being the Persian word for "river". Medieval Arabic and Islamic sources call the river "Jayhoun" (; also "Jaihun", "Jayhoon", or "Dzhaykhun") which is derived from "Gihon", the biblical name for one of the four rivers of the Garden of Eden.
Western travelers in the 19th century mentioned that one of the names by which the river was known in Afghanistan was "Gozan", and that this name was used by Greek, Mongol, Chinese, Persian, Jewish, and Afghan historians. However, this name is no longer used.
The river's total length is and its drainage basin totals in area, providing a mean discharge of around of water per year. The river is navigable for over . All of the water comes from the high mountains in the south where annual precipitation can be over . Even before large-scale irrigation began, high summer evaporation meant that not all of this discharge reached the Aral Sea – though there is some evidence the large Pamir glaciers provided enough melt water for the Aral to overflow during the 13th and 14th centuries.
Since the end of the 19th century there have been four different claimants as the true source of the Oxus:
A glacier turns into the Wakhan River and joins the Pamir River about downstream. Bill Colegrave's expedition to Wakhan in 2007 found that both claimants 2 and 3 had the same source, the Chelab stream, which bifurcates on the watershed of the Little Pamir, half flowing into Lake Chamaktin and half into the parent stream of the Little Pamir/Sarhad River. Therefore, the Chelab stream may be properly considered the true source or parent stream of the Oxus. The Panj River forms the border of Afghanistan and Tajikistan. It flows west to Ishkashim where it turns north and then north-west through the Pamirs passing the Tajikistan–Afghanistan Friendship Bridge. It subsequently forms the border of Afghanistan and Uzbekistan for about , passing Termez and the Afghanistan–Uzbekistan Friendship Bridge. It delineates the border of Afghanistan and Turkmenistan for another before it flows into Turkmenistan at Atamurat. It flows across Turkmenistan south to north, passing Türkmenabat, and forms the border of Turkmenistan and Uzbekistan from Halkabat. It is then split by the Tuyamuyun Hydro Complex into many waterways that used to form the river delta joining the Aral Sea, passing Urgench, Daşoguz, and other cities, but it does not reach what is left of the sea any more and is lost in the desert. Use of water from the Amu Darya for irrigation has been a major contributing factor to the shrinking of the Aral Sea since the late 1950s. Historical records state that in different periods, the river flowed into the Aral Sea (from the south), into the Caspian Sea (from the east), or both, similar to the Syr Darya (Jaxartes, in Ancient Greek).
The of the Amu Darya drainage basin include most of Tajikistan, the southwest corner of Kyrgyzstan, the northeast corner of Afghanistan, a narrow portion of eastern Turkmenistan and the western half of Uzbekistan. Part of the Amu Darya basin divide in Tajikistan forms that country's border with China (in the east) and Pakistan (to the south). About 61% of the drainage lies within Tajikistan, Uzbekistan and Turkmenistan, while 39% is in Afghanistan.
The abundant water flowing in the Amu Darya comes almost entirely from glaciers in the Pamir Mountains and Tian Shan,
which, standing above the surrounding arid plain, collect atmospheric moisture which otherwise would probably escape somewhere else. Without its mountain water sources, the Amu Darya would not exist—because it rarely rains in the lowlands through which most of the river flows. Of the total drainage area only about actively contribute water to the river.
This is because many of the river's major tributaries (especially the Zeravshan River) have been diverted, and much of the river's drainage is arid. Throughout most of the steppe, the annual rainfall is about .
The ancient Greeks called the Amu Darya the "Oxus". In ancient times, the river was regarded as the boundary between Greater Iran and Ṫūrān (). The river's drainage lies in the area between the former empires of Genghis Khan and Alexander the Great, although they occurred at very different times. When the Mongols came to the area, they used the water of the Amu Darya to flood Konye-Urgench. One southern route of the Silk Road ran along part of the Amu Darya northwestward from Termez before going westwards to the Caspian Sea.
It is believed that the Amu Darya's course across the Kara-Kum Desert has gone through several major shifts in the past few thousand years. Much of the time – most recently from the 13th century to the late 16th century – the Amu Darya emptied into both the Aral and the Caspian Seas, reaching the latter via a large distributary called the Uzboy River. The Uzboy splits off from the main channel just south of the river's delta. Sometimes the flow through the two branches was more or less equal, but often most of the Amu Darya's flow split to the west and flowed into the Caspian.
People began to settle along the lower Amu Darya and the Uzboy in the 5th century, establishing a thriving chain of agricultural lands, towns, and cities. In about AD 985, the massive Gurganj Dam at the bifurcation of the forks started to divert water to the Aral. Genghis Khan's troops destroyed the dam in 1221, and the Amu Darya shifted to distributing its flow more or less equally between the main stem and the Uzboy. But in the 18th century, the river again turned north, flowing into the Aral Sea, a path it has taken since. Less and less water flowed down the Uzboy. When Russian explorer Bekovich-Cherkasski surveyed the region in 1720, the Amu Darya did not flow into the Caspian Sea anymore.
By the 1800s, the ethnographic makeup of the region was described by Peter Kropotkin as the communities of "the vassal Khanates of Maimene, Khulm, Kunduz, and even the Badakshan and Wahkran." An Englishman, William Moorcroft, visited the Oxus around 1824 during the Great Game period. Another Englishman, a naval officer called John Wood, came with an expedition to find the source of the river in 1839. He found modern-day Lake Zorkul, called it Lake Victoria, and proclaimed he had found the source. Then, the French explorer and geographer Thibaut Viné collected a lot of information about this area during five expeditions between 1856 and 1862.
The question of finding a route between the Oxus valley and India has been of concern historically. A direct route crosses extremely high mountain passes in the Hindu Kush and isolated areas like Kafiristan. Some in Britain feared that the Empire of Russia, which at the time wielded great influence over the Oxus area, would overcome these obstacles and find a suitable route through which to invade British India – but this never came to pass. The area was taken over by Russia during the Russian conquest of Turkestan.
The Soviet Union became the ruling power in the early 1920s and expelled Mohammed Alim Khan. It later put down the Basmachi movement and killed Ibrahim Bek. A large refugee population of Central Asians, including Turkmen, Tajiks and Uzbeks, fled to northern Afghanistan. In the 1960s and 1970s the Soviets started using the Amu Darya and the Syr Darya to irrigate extensive cotton fields in the Central Asian plain. Before this time, water from the rivers was already being used for agriculture, but not on this massive scale. The Qaraqum Canal, Karshi Canal, and Bukhara Canal were among the larger of the irrigation diversions built. However, the Main Turkmen Canal, which would have diverted water along the dry Uzboy River bed into central Turkmenistan, was never built. The 1970s, in the course of the Soviet–Afghan War, Soviet forces used the valley to invade Afghanistan through Termez. The Soviet Union fell in the 1990s and Central Asia split up into the many smaller countries that lie within or partially within the Amu Darya basin.
During the Soviet era, a resource-sharing system was instated in which Kyrgyzstan and Tajikistan shared water originating from the Amu and Syr Daryas with Kazakhstan, Turkmenistan, and Uzbekistan in summer. In return, Kyrgyzstan and Tajikistan received Kazakh, Turkmen, and Uzbek coal, gas, and electricity in winter. After the fall of the Soviet Union this system disintegrated and the Central Asian nations have failed to reinstate it. Inadequate infrastructure, poor water-management, and outdated irrigation methods all exacerbate the issue.
The Caspian tiger used to occur along the river's banks. After its extirpation, the Darya's delta was suggested as a potential site for the introduction of its closest surviving relative, the Siberian tiger. A feasibility study was initiated to investigate if the area is suitable and if such an initiative would receive support from relevant decision makers. A viable tiger population of about 100 animals would require at least of large tracts of contiguous habitat with rich prey populations. Such habitat is not available at this stage and cannot be provided in the short term. The proposed region is therefore unsuitable for the reintroduction, at least at this stage.
The Oxus river, and Arnold's poem, fire the imaginations of the children who adventure with ponies over the moors of the West Country in the 1930s children's book "The Far-Distant Oxus". There were two sequels, "Escape to Persia" and "Oxus in Summer".
Robert Byron's 1937 travelogue, "The Road to Oxiana", describes its author's journey from the Levant through Persia to Afghanistan, with the Oxus as his stated goal.
George MacDonald Fraser's "Flashman at the Charge", (1973), places Flashman on the Amu Darya and the Arral Sea during the (fictitious) Russian advance on India during The Great Game period. | https://en.wikipedia.org/wiki?curid=3067 |
Muslim conquests of Afghanistan
The Muslim conquests of Afghanistan began during the Muslim conquest of Persia as the Arab Muslims migrated eastwards to Khorasan, Sistan and Transoxiana. 15 years after the Battle of Nahāvand, they controlled all Sasanian domains except parts of Afghanistan and Makran. Fuller Islamization wasn't achieved until the period between 10th and 12th centuries under Ghaznavid and Ghurid dynasty's rule who patronized Muslim religious institutions.
Khorasan and Sistan, where Zoroastrianism was well-established, were conquered, but Qandahar remained unconquered. The Arabs had begun to move towards the lands east of Persia and in 652 they captured the city of Herat, establishing an Arab governor there. The Muslim frontier in modern Afghanistan had become stabilized after the first century of Hijri calendar as the relative importance of the Afghan areas diminished. From historical evidence, it appears Tokharistan was the only area heavily colonized by Arabs where Buddhism flourished. Balkh's final conquest was undertaken by Qutayba ibn Muslim in 705. Hui'Chao, who visited around 726, mentions that the Arabs ruled it and all the inhabitants were Buddhists.
The eastern regions of Afghanistan were considered politically as parts of India. Buddhism and Hinduism held sway over the region until the Muslim conquest. Kabul and Zabulistan which housed Buddhism and other Indian religions, offered stiff resistance to the Muslim advance for two centuries, with the Kabul Shahi and Zunbils remaining unconquered until the Saffarid and Ghaznavid conquests. The significance of the realm of Zun and its rulers Zunbils had laid in them blocking the path of Arabs in invading the Indus Valley.
The Caliph Al-Ma'mun (r. 813–833 A.D.) was paid double the tribute by the Rutbil. His were the last Arab expeditions on Kabul and Zabul. The king of Kabul was captured by him and converted to Islam. The last Zunbil was killed by Ya'qub bin al-Layth along with his former overlord Salih b. al-Nadr in 865. Meanwhile, the Hindu Shahi of Kabul were defeated under Mahmud of Ghazni. Indian soldiers were a part of the Ghaznavid army, Baihaki mentioned Hindu officers employed by Ma'sud. The 14th-century scholar Muslim scholar Ibn Battuta described the Hindu Kush as meaning "slayer of Indians", because large numbers of slaves brought from India died from its treacherous weather.
The geographer Ya'qubi states that the rulers of Bamiyan, called the "Sher", converted in the late 8th century. Ya'qub is recorded as having plundered its pagan idols in 870 while a much later historian Shabankara'i claims that Alp-Tegin obtained conversion of its ruler in 962. No permanent Arab control was established in Ghur and it became Islamised after Ghaznavid raids. By the time of Bahram-Shah, Ghur was converted and politically united.
In the late 15th century, Babur, the founder of the Mughal Empire, arrived from Fergana and captured Kabul from the Arghun dynasty. Between the 16th and 18th centuries, Emperor Shah Jahan and Aurangzeb ruled parts of the eastern territory.
The Afghan habitat during their conquest by Mahmud was located in the Sulaiman Mountains in the South of Afghanistan. They were enlisted by both Sabuktigin and Mahmud according to "Tarikh-i-Yamini". Prior to Pashtun migration to the Kabul River valley, Tajiks formed the dominant population of Kabul, Nangarhar, Logar valley and Laghman in east Afghanistan. The Pashtuns later began migrating westward from Sulaiman mountains in the South, and displaced or subjugated the indigenous populations such as Tajiks, Hazaras, the Farsiwanis, before or during 16th and 17th centuries. The successive wave of Pashtun immigration displaced the original "Kafir" and Pashayi people from Kunar Valley and Laghman valley, the two eastern provinces near Jalalabad, to the less fertile mountains.
Before their conversion, the "Kafir" people of Kafiristan practiced a form of ancient Hinduism infused with locally developed accretions. The region from Nuristan to Kashmir (styled "Peristan" by A. M. Cacopardo) was host to a vast number of "Kafir" cultures. They were called Kafirs due to their enduring paganism, remaining politically independent until being conquered and forcibly converted by Afghan Amir Abdul Rahman Khan in 1895–1896 while others also converted to avoid paying "jizya".
During the Muslim conquest of Persia, the Arabs were drawn eastwards from the Iraqi plains to central and eastern Persia, then to Media, into Khorasan, Sistan and Transoxania. 15 years after the Battle of Nahāvand, the Arabs controlled all Sasanian domain except the parts of Afghanistan and Makran. Nancy Dupree states that advancing Arabs carrying the religion of Islam easily took over Herat and Sistan, but the other areas often revolted and converted back to their old faiths whenever the Arab armies withdrew. The harshness of the Arab rule caused the native dynasties to revolt after the Arab power weakened like the Saffarids founded by the zealous Yaqub who conquered many cities of the region.
Mediaeval Islamic scholars divided modern-day Afghanistan into two regions - the provinces of Khorasan and Sistan. Khorasan was the eastern satrapy of Sasanian Empire, containing Balkh and Herat. Sistan included a number of Afghan cities and regions including Ghazna, Zarang, Bost, Qandahar (also called al-Rukhkhaj or Zamindawar), Kabul, Kabulistan and Zabulistan.
Before Muslim rule, the regions of Balkh (Bactria or "Tokharistan"), Herat and Sistan were under Sasanian rule. Further south in Balkh region, in Bamiyan, indication of Sasanian authority diminishes, with a local dynasty seeming ruling from the late antiquity, probably Hepthalites subject to the Yabgu of Western Turks. While Herat was controlled by Sasanians, its hinterlands were controlled by northern Hepthalites who continued to rule the Ghurid mountains and river valleys well into the Islamic era. Sistan was under Arabs but Qandahar remained out of Arab rule. Kabul and Zabulistan, housed Indic religions with the Zunbils and Kabul Shahis offering stiff resistance to Muslim rule for two centuries until Saffarid and Ghaznavid conquests.
In Afghanistan, the frontier of the Islamic conquest had become more or less stationary by the end of the first century of Hijri calendar. One reason was the relative importance of Sistan and Baluchistan had begun to diminish by the time of Mu'awiyah I, when the conquests of Bactria and Transoxania were undertaken. In addition, the conquest in the eastern direction were extended to Makran and Sind, with Muslim colonies becoming established there in 711–12.
The earlier Arabs called Sistan as "Sijistan", from the Persian "Sagestan". It is a lowland region, lying round and eastwards from the Zarah lake, which includes deltas of Helmand and other rivers which drain into it. Muslim conquest of Sistan began in 23 A.H. (643-644 A.D.) when Asim bin Amr and Abdallah ibn Amir invaded the region and besieged Zaranj. The Sistanis concluded a treaty with Muslims, mandating them to pay the kharaj.
The cash-strapped Sasanian king Yazdegerd III who had a large retinue, had fled to Kerman in 650. He had to flee from Kerman to Sistan after his arrogance angered the marzban of the place, eluding an Arab force from Basra which defeated and killed the marzban. Yazdegerd lost the support of governor of Sistan after demanding taxes from him and had to leave for Merv. It is not known whether this governor was a Sasanian prince or a local ruler at that time. The Arabs had campaigned in Sistan a few years earlier and Abdallah b. Amir had now gone in pursuit of Yazdegerd. He arrived in Kirman in 651 and sent a force under Rabi ibn Ziyad al-Harithi to Sistan.
Rabi crossed the desert between Kirman and Sistan, reaching the fortress of Zilaq which was within five farsangs of the Sistan frontier. The fort was surrendered by its dihqan. The fortress of Karkuya, whose fire temple is mentioned in the anonymously authored "Tarikh-e-Sistan", along with Haysun and Nashrudh, surrendered to Rabi. Rabi then encamped in Zaliq and projected the seizure of Zarang, which though had earlier submitted to Arabs, needed to be subdued again. Although its marzaban Aparviz put up a strong resistance, he was forced to surrender.
The Zaranj forces had received heavy casualties during the battle with Arab forces and were driven back to the city. According to sources, when Aparviz appeared before Rabi to discuss the terms, he found the Arab general was sitting on a chair made out of two dead soldiers and his entourage had been instructed to make seats and bolsters in the same fashion. Aparviz was terrified into submission and wished to spare his people of this fate. A peace treaty was concluded with payments of heavy dues. The treaty mandated one million dirhams as annual tribute, in addition to a 1,000 slave boys bearing 1,000 gold vessels. The city was garrisoned by Rabi.
Rabi thus succeeded in gaining Zarang with considerable difficulty and remained at the place for several years. Two years later, the people of Zarang rebelled and expelled Rabi's lieutenant and garrison. Abdallah b. Amir sent 'Abd ar-Rahman b. Samura to take back the city, who also added Bust and Zabul to Arab gains. 'Abd ar-Rahman besieged Zaranj and after the marzban surrendered, the tribute was doubled. The tribute imposed on Zarang was 2 million dirhams and 2,000 slaves.
During the period of the first civil war in the Arab caliphate (656-661), rebels in Zarang imprisoned their governor while Arab bandits started raiding remote towns in Sistan to enslave people. They gave in to the new governor Rib'i, who took control of the city and restored law and order. 'Abdallah b. Amir was made the governor of Basra and its eastern dependencies again from 661 to 664. Samura was sent back to Sistan in 661. An expedition to Khorasan was sent under Samura, a Qurayshite, that included reputed leaders like 'Umar b. 'Ubaydillah b. Ma'mar, 'Abdullah b. Khazim, Qatariyy b. al-Fuja'a and Al-Muhallab ibn Abi Sufra. He reconquered Zarang, attacked Zabulistan's ruler Zunbil and entered Kabul after a brief siege.
Ziyad ibn Abihi was appointed governor of Basra in 664 and was also made governor of Kufa and its dependencies in 670, making him the viceroy of the entire eastern half of the Islamic empire. He sent his kinsman Ubaydallah b. Abi Bakra to destroy the Zoroastrian fire temples in Fars and Sistan, confiscate their property and kill their priests. While the fire temple of Kariyan was destroyed, the one at Karkuya survived along with its herbad. Ziyad's son Abbad was appointed governor of Sijistan by Mu'awiya I in 673 and served until 681. During the course of his governorship, the province apparently remained stable and Abbad led an eastward expedition which brought Kandahar to the caliphate. Caliph Yazid I replaced Abbad with his brother Salm, who was already governor of Khurasan.
There is general agreement among Arabic sources that Khorasan's conquest began in the reign of Uthman under Abdallah b. Amir who had been appointed the governor of Basra (r. 649-655). Sayf's tradition however disagrees with this, dating it to 639 under the reign of Umar with Ahnaf ibn Qais leading the expedition. Al-Tabari meanwhile relates that Ahnaf's conquests occurred in 643. This could be because of confusion of Ahnaf's later activities under Ibn Amir and an attempt to magnify his role in Khorasan's conquest.
The conquest of southern Persia was completed by 23 A.H. with Khorasan remaining the only region remaining unconquered. Since the Muslims didn't want any Persian land to remain under Persian rule, Umar ordered Ahnaf b. Qais to march upon it. After capturing towns of Tabas and Tun, he attacked the region's easternmost city Herat. The Persians put up stiff resistance but were defeated and surrendered. A garrison was deployed in the city, while a column was detached which subjugated Nishapur and Tus. Umar had despatched Ahnaf with 12,000 men from Kufa and Basra after Yazdegerd who had fled to Merv. After the Arabs arrived there, Yazdegerd fled to Marw al-Rudh from where he sent ambassadors to the Khakan of the Turks, the ruler of Soghd and the Chinese emperor, asking for their assistance. Yazdegerd later fled to Balkh, where he was defeated by the Arabs and fled across Oxus River.
Umar forbade Ahnaf from crossing the river as the land beyond it was unknown to Arabs and was very far for them. Yazdegerd proceeded to Soghd whose ruler supplied him a large army. The Khaqan of Turks after assembling the troops from Ferghana, crossed the Oxus along with Yazdegerd and marched to Balkh. Ribi' b. Amir meanwhile retired with Kufan troops to Marw al-Rudh where he joined al-Ahnaf. The Sasanian king and the Khakan leading an army of 50,000 cavalry composed of men from Soghd, Turkestan, Balkh and Tokharistan, arrived at Marw al-Rudh. Ahnaf had an army of 20,000 men. The two sides fought each other from morning till evening for two months at a place called Deir al-Ahnaf.
The fighting at Deir al-Ahnaf went on until Ahnaf, after being informed of a Turkic chief inspecting the outposts, went there during a particular night and successively killed three Turkic chiefs during their inspection. After learning of their deaths, the Khakan became afflicted by it and withdrew to Balkh, then he withdrew across the river to Turkestan. Yazdegerd meanwhile left from Marw al-Rudh to Merv, from where he took his empire's wealth and proceeded to Balkh to join the Khakan. He told his officials he wanted to hand himself to the protection of the Turks, but they advised him against it and asked him to seek protection from the Arabs which he refused. He left for Turkestan while his officials took away his treasures and gave them to Ahnaf, submitting to the Arabs and were allowed to go back to their respective homes.
Abdullah b. Amir went to Khorasan from Kerman in 650 and sent out along with a vanguard of Tamimi Arabs and 1,000 asawira via Quhistan. The people of Tabasayn had broken their peace treaty and had allied with the Hepthalites of Herat. al-Ahnaf reconquered Quhistan and defeated Herat's Hepthalites at Nishapur. The kanarang or marzaban of Tus asked the Arabs for assistance against the raiding Hepthalites of Herat and Badghis. He agreed to a peace agreement for 600,000 dinars.
The Hepthalite action prompted the Muslims undertaking military operation to secure their positions in Khorasan. After fall of Tus, Ibn Amir sent out an army against Herat. The ruler (marzaban or "azim") of the place agreed to a peace treaty for Herat, Badghis and Pushang for a tribute of 1 million dirhams. The ruler who was known as "azim" or the "mighty one" in Futuh al-Buldan, may have been a Hepthalite chief. The "Rightly Guided Caliphs" followed the earlier rule of Muhammad of imposing "jizya" on several bodies jointly and in some cases also imposed the condition they host Muslims. This rule was followed in most Iranian towns, with the jizya not specified on per capita basis, but was left to the local rulers though some Muslim commanders stressed the amount on the ability of the ruler to pay. The same wording can be seen in Ibn Amir's treaty.
In 652, Ibn Amir sent al-Ahnaf to invade Tokharistan with 4,000 Arabs and 1,000 Iranian Muslims (evidently the Tamimis and asawira), probably because of assistance of its ruler to Yazdegerd's son Peroz. While Marw al-Rudh's garrison agreed to a peace term for the entire district under 300,000 dirhams, the town itself remained besieged. The last major stronghold of Sasanians, Marw al-Rudh, fell to him after a fierce battle. After bloody fighting, its marzaban agreed to a peace treaty for 60,000 or 600,000 dirhams as well as a mutual defence pact. He was also allowed to keep his ancestral lands, for the office of marzaban to be hereditary in his family and to be exempt from taxes along with his whole family. Baladhuri quotes Abu Ubayda as stating that the Turks were supporting the inhabitants of the town. These Turks were Hepthalites, probably from Guzgan which may explain the reason behind Arabs next attacking Guzgan, Faryab and Talqan.
Al-Mada'ini specifically states that Ahnaf while leading the next expedition, didn't want to ask for assistance from the non-Muslims of Marw al-Rudh, probably as he didn't trust them. The Arabs camped at Qasr al-Ahnaf, a day's march to north of Marw al-Rudh. The 30,000-strong army comprising troops of Guzgan, Faryab and Talqan, supported by the Chaghanian troops, advanced to meet them. The battle was inconclusive, but the opposing side dispersed with some remaining at Guzgan while Arabs withdrew to Marw al-Rudh. Ahnaf sent an expedition, led by al-Aqra' b. Habis and apparently consisting exclusively of Tamims, to Guzgan. The Arabs defeated Guzgan and entered it by force. Ahnaf meanwhile advanced towards Balkh, making peace treaties with Faryab and Taloqan along the way.
The permanent pacification of Khorasan was a protracted affair with the local potentates often rebelling and appealing to outside powers like the Hepthalites, Western Turks or Turgesh, Sogdians and the imperial Chinese who claimed a degree of suzerainty over Central Asia, for help. Within a year after Yazdegerd's death, a local Iranian notable named Qarin started a revolt against the Arabs in Quhistan. He gathered his supporters from Tabasayn, Herat and Badghis, assembling a reported army of 40,000 insurgents against Arabs in Khorasan. The Arabs made a surprise attack however, killing him and many of his people while many others were taken captive. It was expected that the recently subjugated people would revolt. However, in Khorasan, no all-out effort seems to have been undertaken to the expel the Arabs after Qarin's rebellion. Chinese sources state that there was an attempt to restore Peroz by Tokharistan's army, however this episode is not confirmed by Arab sources.
Peroz had settled among the Turks, took a local wife and had received troops from king of Tokharistan. In 661, he established himself as king of Po-szu (Persia) with Chinese help in a place the Chinese called Ja-ling (Chi-ling), which is assumed to be Zarang. His campaigns are reflected in Muslim sources, which mention revolts in Zarang, Balkh, Badghis, Herat, Bushanj and also in Khorasan during the First Fitna period in reigns of Ali and Muawiyah. Though they don't mention Peroz, they do state that Ali's newly appointed governor of Khorasan had heard in Nishapur that governors of the Sasanian king had come back from Kabul and Khorasan had rebelled. However, the region was reconquered under Muawiyah. Piroz went back to Tang Empire's capital and was given a grandiose title as well as permission to build a fire temple in 677.
Yazid ibn al-Muhallab succeeded his father as governor of Khorasan in 702 and campaigned in Central Asia, but achieved little success apart from Nezak Tarkhan's submission at Badghis.
Tokharistan, roughly ancient Bactria, is today divided between Afghanistan, Tajikistan and Uzbekistan. According to the most general usage of the name, Tokharistan is the wide valley around the upper Oxus river surrounded by mountains on three sides before the river moves into open plains. The major city was Balkh, one of the greatest urban centers of northeastern Iran. It was located upon crossroads and conduits of trade in many directions, enabling control of these routes if it was conquered. During the governorship of Abu 'l Abbas 'Abdallah b. Tahir (r. 828–845), a list of districts ("kuwar") of the region exists, including as far as Saghaniyan in the north and Kabul in the south. Other places listed are Tirmidh, Juzjan, Bamiyan, Rūb and Samanjan. Some Arab geographers used the name only for southern part of Oxus valley.
Balkh was also a part of Khorasan along with other areas through varying extensions of time. Per al-Tabari, Yazdegerd fled from Marw-al Rudh to Balkh during Ahnaf's conquest of Khorasan in 643. He fortified himself but was defeated by the Arabs and fled across the Oxus River. Yazdegerd proceeded to Soghd whose ruler supplied him a large army. The Khaqan of Turks after assembling the troops from Ferghana, crossed the Oxus along with Yazdegerd and marched to Balkh.
In 652, Ibn Amir sent al-Ahnaf to invade Tokharistan with 4,000 Arabs and 1,000 Iranian Muslims (evidently the Tamimis and asawira), probably because of assistance of its ruler to Yazdegerd's son Peroz. He approached Balkh after conquering Marw al-Rudh and fighting an inconclusive battle with a 30,000-strong force from Guzgan, Faryab and Talqan. After arriving at Balkh, he besieged the city, with its inhabitants offering a tribute of 400,000 or 700,000 dirhams. He deputed his cousin to collect the tribute and advanced to Khwarezm but returned to Balkh as winter approached. It was in Balkh in fall of 652 when the local people introduced his cousin Asid to gifting gold and silver to their governor during Mihrijan.
Ziyad b. Abi Sufyan reorganised Basra and Kufa, excluding many from the "diwan" and inspiring him to settle 50,000 families in Khorasan. Both Baladhuri and Mad'aini agree upon the number, though the latter states each half were from Basra and Kufa. Al-'Ali disagrees, stating the Kufans were 10,000. Ghalib had been unsuccessful in his expedition, and Rabi b. Ziyad al-Harithi who was appointed governor of Khorasan in 671 led the settlement expedition. He advanced to Balkh and made a peace treaty with the locals who had revolted after al-Ahnaf's earlier treaty.
Qutayba ibn Muslim led the final conquest of Balkh. He was tasked with subduing the revolt in Lower Tokharistan. His army was assembled in spring of 705 and marched through Marw al-Rudh and Talqan to Balkh. Per one version in Tarikh al-Tabari, the city was surrendered peacefully. Another version, probably to promote a Bahilite claim on the Barmakids, speaks of a revolt among the residents. The latter may be the correct version as Tabari describes the city as ruined four years later. The wife of Barmak, a physician of Balkh, was taken captive during the war and given to 'Abdullah, Qutayba's brother. She was later restored to her lawful husband after spending a period in 'Abdullah's harem. Khalid was thus born in 706 and Abdallah accepted the implications of paternity without disturbing Barmak's conventional responsibilities or affecting Khalid's upbringing.
In 708–709, the Ispahbadh who was a local ruler, received a letter from the Hepthalite rebel Nizak Tarkhan who was trying to unite the aristocracy of Tokharistan against Qutayba. The Arabs built a new military encampment called "Baruqan" two farsangs away from the city. In 725, the governor Asad ibn Abdallah al-Qasri had the city restored after a feud among Arab troops with Barmak being employed as his agent for the task.
Early Arabs tended to treat Iran as a single cultural unit, however it was a land of many countries with distinct populations and cultures. From historical evidence, it appears Tokharistan was the only area heavily colonized by Arabs where Buddhism flourished and the only area incorporated into the Arab empire where Sanskrit studies were pursued up to the conquest. The grandson of Barmak was the "vizier" of the empire and took personal interest in Sanskrit works and Indian religions. The eighth-century Korean traveller Hui'Chao records Hinayanists in Balkh under Arab rule. He visited the area around 726, mentioning that the true king of Balkh was still alive and in exile. He also describes all the inhabitants of the regions as Buddhists under Arab rule. Other sources indicate however that the Bactrians practiced many different religions.
Among Balkh's Buddhist monasteries, the largest was "Nava Vihara", later Persianized to "Naw Bahara" after the Islamic conquest of Balkh. It is not known how long it continued to serve as a place of worship after the conquest. Accounts of early Arabs offer contradictory narratives. Per al-Baladhuri, its stupa-vihara complex was destroyed under Muawiyah in 650s. Tabari while reporting about the expedition in 650s, does not mention any tension around the temple, stating Balkh was conquered by Rabi peacefully. He also states that Nizak went to pray at the site during his revolt against Qutayba in 709, implying it may not have been destroyed. Also the tenth-century geographical treatise "Hudud al-'Alam" describes remaining royal buildings and Naw Bahara's decorations including painted image and wonderful works, probably secco or fresco murals and carvings on the temple's walls that survived into the author's time.
Sanskrit, Greek, Latin and Chinese sources from the 2nd century BCE to the 7th century CE, identify a people called "Tukharas", in the country later called Tukharistan. Badakhshan was earlier the seat of the Tukharas. There is no precise date for the Arab conquest of Badakhshan nor any record of how Islam was introduced there. Al-Tabari too mentions this region only once. In 736, Asad ibn Abdallah al-Qasri sent an expedition into Upper Tokharistan and Badakhshan against the rebel Al-Harith ibn Surayj who had occupied the fortress of Tabushkhan. Juday' b. 'Ali al-Kirmani who was sent on the expedition against al-Harith, captured Tabushkhan. Juday also had its captive defenders killed while its women and children were enslaved and sold in Balkh despite being of Arab origin. al-Harith later allied with the Turgesh and continued his rebellion until being pardoned by Caliph Yazid b. Walid in 744.
Taking advantage of the factional fighting among the Arabs, Transoxania started rebelling and Asad b. 'Abdallah in response attacked Khuttal in 737. Armed forces of Soghd, Chach and many Turks, led by the Turkish Khagan Sulu, arrived to assist them. Asad fled leaving behind the baggage of plunder from Khuttal. When Asad returned with the main body of his troops, the Turks retired to Tokharistan and he returned to Balkh. In December 737, the Turgesh attacked Khulm but were repelled by Arabs. Bypassing Balkh, they captured Guzgan's capital and sent out raiding parties. Asad mounted a surprise attack on the Turks at Kharistan who only had 4,000 troops. The Turgesh suffered a devastating defeat and lost almost whole of their army. Sulu and al-Harith fled to the territory of Tokharistan's Yabghu, with Sulu returning to his territory in winter of 737–738.
The Zunbils in the pre-Saffarid period ruled in Zabulistan and Zamindawar, stretching between Ghazna and Bost, and had acted as a barrier against Muslim expansion for a long time. Zamindawar is known to have a shrine dedicated to the god Zun. It has been linked with the Hindu god Aditya at Multan, pre-Buddhist religious and kingship practices of Tibet as well as Shaivism. The followers of the Zunbils were called Turks by the Arabic sources, however they applied the name to all their enemies in eastern fringes of Iran. They are described as having Turkish troops in their service by sources like Tabari and "Tarikh-e-Sistan".
The kingdom of Zabulistan (ar-Rukhkhaj) with its capital at Ghazna, where the king Zunbil or Rutbil resided, is mentioned by Chinese sources under the suzerainty of Jabghu of Turkestan. The significance for Arabs of the realm of Zun and its rulers was them preventing their campaigns from invading the Indus Valley through eastern and southern Afghanistan. It was only under the early Saffarids that mass-Islamization and conquests of the region took place unlike the plunder-raids or tribute levies of Arabs. The expeditions under Caliph al-Ma'mun against Kabul and Zabul were the last ones and the long conflict ended with the dissolution of the Arab empire following soon thereafter.
Sakawand in Zabulistan was a major centre of Hindu pilgrimage.
After appearing at Zarang, 'Abd ar-Rahman b. Samura and his force of 6,000 Arabs penetrated to the shrine of Zun in 653–654. He broke off a hand from the idol of Zun and plucked out the rubies used as its eyes to demonstrate to the marzban of Sistan that the idol could neither hurt nor benefit anyone. He also took Zabul by treaty by 656. Per Baldhuri, after being reappointed to Sistan under Muawiyah, Samura defeated Zabulistan whose people had broken the earlier agreement.
Samura was replaced by Rabi b. Ziyad and died in 50 A.H. (670 A.D.), after which the king of Zabul rebelled and conquered Zabulistan and Rukhkhaj. Ar-Rabi, the Arab governor, attacked him at Bust and made him flee. He then pursued him to Rukhkhaj where he attacked him and then subdued the city of ad-Dawar. Ziyad b. Abi Sufyan was appointed governor of Basra in 665, with Khorasan and Sistan coming under his mandate as well. He had first appointed Rabi to Sistan but replaced him later with 'Ubaydallah b. Abi Bakra. During this period, Zunbil's fierce resistance continued until he finally agreed to pay one million dirhams per Baladhuri and "Tarikh-e-Sistan".
Al-Baladhuri records that under Muawiyah, Sistan's governor 'Abbad b. Ziyad b. Abihi raided and captured the city of Qandahar after bitter fighting. He also mentions the characteristic high caps of the people of the city. Though his text is somewhat ambiguous, it seems that 'Abbad had renamed the town as "'Abbadiya" after himself. The Muslim rule was probably toppled and the name is never heard after his governorship ended in 680–1, by 698 there was no Muslim-controlled region east of Bost. The city was ruled by Arab Muslims and Zunbils, and then later Saffarids and Ghaznavids. It is infrequently mentioned in the early Islamic sources.
In 681, Salm b Ziyad was appointed the governor of Khorasan and Sistan by Yazid I. He appointed his brother Yazid b. Ziyad, apparently to lead a military expedition against the Zunbil of Zabulistan. The expedition however was disastrous, with Yazid being killed, his brother Abu-'Ubayda captured, while Arabs received heavy casualties. Salm sent an expedition by Talha b. 'Abdillah al-Khuzai to rescue his brother and pacify the region. The Arab captives were ransomed for half million dirhams and the region was pacified more through diplomacy than force.
After Talha's death in 683–684, a virtual anarchy was unleashed amongst Sistan's Arabs. His army refused allegiance to Yazid or Muawiyah II and his son 'Abadallah had to abandon Zarang, which was left without any incharge. Many Arabs took over various quarters of Zarang and areas of Sistan. This prompted Zunbil and his allies who had already inflicted a humiliating defeat on the Arabs earlier, to intervene in the Arab affairs at Sistan and Bust. Baladhuri says of this period:
During the Second Fitna period, the Zunbil attacked Sistan in 685 but was defeated and killed by the Arabs.
Abdalmalik appointed Umayya b. 'Abdillah b. Khalid b. Asid as governor of Khorasan in 74 A.H. (693-4 A.D.), with Sistan included under his governorship. Umayya sent his son Abdullah as head of the expedition in Sistan. Though initially successful, the new Zunbil was able to defeat them. Per some accounts, Abdullah himself was killed. Umayya was dismissed and Sistan added to governorship of al-Hajjaj ibn Yusuf.
Al-Hajjaj, who had become governor of Iraq and the East in 78 A.H. (697–98), had appointed Ubaidallah, who was a "mawla" of mixed Abyssinian and Iraqi-Persian origins, as his deputy in Sistan. The Zunbils who had been left unchecked had completely stopped paying the tribute. This provided a pretext to terminate the peace between the both sides. Ubaidallah was appointed for an expedition against them in 698 and was ordered by Al-Hajjaj to "attack until he laid waste to Zunbil's territories, destroyed his strongholds, killed all his fighting men and enslaved his progeny". The ensuing campaign was called the "Army of Destruction" ("Jaish al-Fana"'). However, it ended disastrously for the Arabs.
Al-Baladhuri's account on the authority of Al-Mada'ini in "Futuh al-Buldan" and "Ansab al-Ashraf", is the fullest documentation of the campaign. Tabari's account runs parallel but is based on Abu Mikhnaf and does not include the poem of A'sha Hamdan included in "Ansab al-Ashraf". Ibn Qutaybah's "Kitab al-Ma'arif" only makes a bare mention. "Ta'rikh al-khulafa'" has a more detailed account and epitomises accounts of Tabari and Baladhuri. "Tarikh-e-Sistan" confuses the campaign with another one against the Khwarij of Zarang. The army consisted of Iraqis from Basra and Kufa, though Baladhuri mentions presence of some Syrians. Ubaidallah himself led the Basrans while the Tabi Shuraih b. Hani' al-Harithi ad-Dabbi led the Kufans.
They marched to Zamindawar or al-Rukhkhaj (the classical Arachosia) but found it was barren and foodless. Their advance probably happened in summer of 698 as A'sha Hamdan's poem refers to the scorching heat they had to endure. In Zabulistan's regions of Ghazna and Gardiz, they plundered a significant amount of cattle and other animals in addition to destroying various strongholds. The Zunbils who were devastating the countryside whilst retreating, were luring the Arabs into a trap to an inhospitable and foodless terrain. "Futuh al-Buldan" states that the Muslims almost penetrated Kabul. Tabari meanwhile says that they came within 18 farsakhs of the summer capital of Zunbils in the Qandahar region.
The plan of the Zunbils worked and they trapped the Arabs into a valley. Ubaidallah realizing the gravity of the situation, offered 500,000 or 700,000 dirhams as well as his three sons along with some Arab leaders as hostages while promising not to raid again during his tenure as Sistan's governor. Shuraih, who had earlier advised retreat, felt a withdrawal would be dishonorable. He was joined by a group of people into the battle, and all but a handful of them were killed. The remnant of the Arab army withdrew back to Bust and Sistan, suffering from starvation and thirst. Many died in the "Desert of Bust", presumably the Registan Desert, with only 5,000 making it back to Bust. Many of those who survived died by gorging themselves on the food sent to them according to Tabari. Ubaidallah had arranged food for them after seeing their suffering and himself died, either from grief or an ear affliction.
Al-Hajjaj prepared another expedition in 699, reportedly of 40,000 troops from Kufa and Basra under Abdurrahman b. Muhammad b. al-Ash'ath. Though disguised as a military expedition, it was actually a forced migration of the elements from the two Iraqi cities troublesome to Hajjaj. It was equipped to the best standards and was called the "Army of Peacocks" because of the men included in its ranks. It included proudest and most distinguished leaders of Iraq led by Ibn al-Ash'ath, grandson of Al-Ash'ath ibn Qays. It also included distinguished elders who served in the first armies of conquest as well as those who fought at Battle of Siffin. This Arab army arrived in Sistan in the spring of 699.
The Arabs advanced east into Zabulistan and won several victories. However the troops didn't want to fight in this inhospitable region and started becoming restive. Al-Hajjaj instructed them to continue the advance into Zabulistan's heart no matter what it took, making it clear to them he wanted them to return to their homes. Ibn al-Ash'ath also made an agreement with the Zunbils, that no tribute would be demanded if he won and in case he lost, he would be sheltered to protect him from Al-Hajjaj. The troops mutinied against Hajjaj's enforced emigration and returned to Iraq but were crushed by the Syrian troops. They fled back to the east while Ibn al-Ash'ath fled to Sistan where he died in 704 A.D.
When Ibn al-Ash'ath returned to Sistan in 702-703 A.D., he wasn't allowed into Zarang and fled to Bust where he was abducted by Iyad b. Himyan al-Bakri as-Sadusi, who he had appointed as the deputy over Bust, so Iyad could resecure favor of al-Hajjaj. Zunbil however attacked the town and threatened to slaughter or enslave everyone there unless Ibn al-Ash'ath was handed over to him. Iyad set him free and he went to Zunbil's territory along with his army. Zunbil was persuaded by Al-Hajjaj's representative to surrender him. His fate is however unclear. Per some accounts, he committed suicide while according to others he was killed by the Zunbil who sent his head to the Umayyads in Sistan. Following this, a truce was declared between Al-Hajjaj and Zunbil in return for the latter paying tribute in kind and in return, Al-Hajjaj promised not to attack him.
Qutayba b. Muslim, the conqueror of Transoxiana, preferred not to fight the Zunbils and accepted an offer of a rather minimal tribute from them, calling Sijistan an "ill-omened front". Until the reign of Hisham ibn Abd al-Malik, the Sijistan front had ceased to be volatile as the Arabs had given up on conquering the area and no fighting occurred for a long period. This in turn holding led to Zunbils not even paying a token tribute. The policy began to change under Hisham. Khalid al-Qasri in Iraq appointed Yazid b. al Ghurayf al-Hamdani as Sistan's governor, a Syrian from Jund al-Urdunn, in 725. Yazid resumed the campaign by sending an army under the command of Balal b. Abi Kabsha. They however did not obtain anything from the Zunbils.
The new governor of Sistan, al-Asfah b. 'Abd Allah al-Kalbi, a Syrian, embarked on ambitious policy of campaigning against the Zunbils. The first one was carried out in 726. During the second one in late 727–728, he was warned by the Sijistanis who were with him to not campaign in winter especially in mountain defiles. Per Ya'qubi, his army was completely annihilated by the Zunbils. Per "Tarikh al-Sistani", al-Asfah managed to get back to Sistan where he died. The next two governors didn't undertake any campaigns. Zunbil was unable to take advantage of the annihilation of al-Asfah's army but the defeat was a heavy one. It would become one in a series of blows for the caliphate.
The Sistan front remained quiet in latter part of Abd al-Malik's reign except perhaps the Kharjite activity, with long tenures and blank records of 'Abd Allah b. Abi Baruda and Ibrahim b. 'Asim al-'Uqayli suggesting that the instability in the region had been controlled to extent. It appears this was only possible because no more campaigns were undertaken against the Zunbils.
Al-Mansur sent Ma'n b. Zaida ash-Shabani sent to Sistan in response to disturbances in Sistan. Ma'n along with his nephew Yazid b. Ziyad undertook an expedition against the Zunbil for making him obedient and restoring the tribute not paid since the time of al-Hajjaj. It is especially well-documented by al-Baladhuri. He ordered the Zunbil to pay the tribute and was offered camels, Turkish tents and slaves, but this did not placate him. Per al-Baldahuri, under the reign of al-Mansur, Hisham b. 'Amr al-Taghlibi after conquering Kandahar, destroyed its idol-temple and built a mosque in its place.
Ma'n and Yazid advanced into Zamindawar but the Zunbil had fled to Zabulistan. They nonetheless pursued and defeated him, taking 30,000 as captives including Faraj al-Rukhkhaji, who would later become a secretary of the department of private estates of the Caliph under al-Ma'mun. Zunbil's deputy Mawand (Zunbil's son-in-law Mawld in "Tarikh-e-Sistan") offered submission which was requested and he was sent with 5,000 of their soldiers to Baghdad where he was treated kindly and given pensions along with his chieftains per Baladhuri.
The tribute was paid by the Zunbils to "amils" of caliphs al-Mahdi and ar-Rashid, though rather irregularly. When the Caliph Al-Ma'mun (r. 813–833 A.D.) visited Khorasan, he was paid double the tribute by Rutbil, but was evidently left unmolested and the Arabs later subdued Kabul.
The area had been under the rule of the Turk Shahi who took over the rule of Kabul in the seventh century and later were attacked by the Arabs. The Turk Shahi dynasty was Buddhist and were followed by a Hindu dynasty shortly before the Saffarid conquest in 870 A.D. Al-Ma'mun's expeditions were the last Arab conflict against Kabul and Zabul and the long-drawn conflict ended with the dissolution of the empire. Muslim missionaries converted many people to Islam; however, the entire population did not convert, with repetitive revolts from the mountain tribes in the Afghan area taking place. The Hindu Shahi were defeated by Mahmud of Ghazna (r. 998-1030) who expelled them from Gandhara and also encouraged mass-conversions in Afghanistan and India.
When Ar-Rabi b. Ziyad reached Helmand, the Zunbils held power as far as Zarang. The "Kabulshah" was a subordinate of the Zunbil. Subsequent to the first Arab clashes with the Zunbils and Kabulshahs, we find the Zunbil negotiating with the representatives of the Caliph "for his own country and the land of Kabul." The Zunbils were linked to the Turki Shahi dynasty of Kabul, which was at the time a cultural and religious outpost of the Indian world.
During the caliphate of Uthman, new popular uprisings had broken out in Persia and continued for five years from 644–649. The revolts were suppressed and Abdullah b. Amir, who was appointed governor of Basra, had captured many cities including Balkh, Herat and Kabul. After Muawiyah became the Caliph, he prepared an expedition under 'Abd ar-Rahman b. Samura to Khorasan. Per Baladhuri, after recapturing Zarang as well as conquering other cities, they besieged Kabul for a few months and finally entered it. Per the historian Firishta, while capturing Kabul in 664 A.D., Samura had made converts of some 12,000 people. Kabul's ruler was obliged to pay a tribute. This didn't last long as he soon drove out the Arabs from his lands after Samura's death. A treaty was renegotiated but about the time of death of Yazid I, "the people of Kabul treacherously broke the compact". The Arab army sent to reimpose it was routed.
In about 680–683, the Shah fled from his brother Rutbil and approached Salm b. Ziyad at Amul in Khorasan where he accepted his suzerainty. The reason for the Shah's refuge is not known. After his successes in Zabulistan, the Rutbil may have assumed a threatening position to him, causing him to seek help of Arabs. A treaty was agreed with the Shah though its terms are not known. He was allowed to settle down in Amul (or at least under Amul's jurisdiction somewhere north of Hindu Kush). Per Tabari, Salm was elated at this and wrote to Mu'awiyah who disapproved of it. When asked the reason, he responded that "there is a lot of ill-will and bad feeling in Zaranj and Amul. The people living in the lands between these two places are disloyal and treacherous. They are likely to take advantage of the moment of our weakness and, then, it would be easier for them to capture the territory up to Amul". And it precisely happened after Muawiyah's death per Tabari.
The Shah captured Amul and became powerful enough to threaten Rutbil who went into hiding. Zunbil's brother, "'al-Shah" also besieged Zaranj, but the Turks retreated after reinforcements arrived from Basra. Abdur Rehman who studied the descriptions of Tabari however stated that these events should be seen as having happened in Yazid's time since Salm was governor under his reign. In 152 A.H. (769 A.D.), Humayd ibn Qahtaba, the governor of Khorasan, raided Kabul. According to Ibn al-Athir, al-'Abbas b. Ja'far led an expedition against Kabul sent by his father Ja'far b. Muhamamad in 787–78, which Bosworth claims is the one attributed to Ibrahim b. Jibril by Al-Ya'qubi.
The only record of an event in early Abbasid period obviously related to the area south of the Hindu Kush, is the expedition against Kabul in 792-793 ordered by Al-Fadl ibn Yahya and led by Ibrahim b. Jibril. It is mentioned by al-Tabari's chronicle, the tenth century "Kitāb al-Wuzarā'wa al-Kuttāb" of al-Jahshiyari and by al-Ya'qubi. Per al-Jahshiyari, he conquered Kabul and acquired a lot of wealth. Al-Ya'qubi states that rulers and landlords of Tukharistan, including Bamiyan's king, joined this army, implying it crossed Hindu Kush from the north. It also mentions subjugation of "Ghurwand" (present-day Ghorband). He also mentions the "Pass of Ghurwand" which judging by the itinerary of the expedition from Tukharistan to Bamiyan to Ghorband valley, is identical to Shibar Pass. They then marched to Shah Bahar where an idol venerated by the locals was destroyed. The inhabitants of various towns then concluded peace treaties with Fadl, one of which was identified by Josef Markwart as Kapisa.
Al-Ma'mun (r. 813–833 A.D.) while visiting Khorasan, launched an attack on Kabul, whose ruler submitted to taxation. The king of Kabul was captured and he then converted to Islam. Per sources, when the Shah submitted to al-Ma'mun, he sent his crown and bejeweled throne, later seen by the Meccan historian al-Azraqi to the Caliph who praised Fadl for "curbing polytheists, breaking idols, killing the refractory" and refers to his successes against Kabul's king and "ispahabad". Other near-contemporary sources however refer to the artifacts as a golden jewel-encrusted idol sitting on a silver throne by the Hindu Shahi ruler or by an unnamed ruler of "Tibet" as a sign of his conversion to Islam.
Qutayba b. Muslim was appointed the governor of Khorasan in 705 by al-Hajjaj b. Yusuf, the governor of Iraq and the East. He began his rule with the reconquest of western Tokharistan in the same year. Qutayba who was tasked with subduing the revolt in Lower Tokharistan, led the final conquest of Balkh. His army was assembled in spring of 705 and marched to Balkh. Per one version of al-Tabari, the city was surrendered peacefully. Another version, speaks of a revolt among the residents. In 706, he received the submission of Nizak, the leader of Badghis. In 707, he marched on Bukhara oasis along with Nizak in his army but the campaign didn't achieve any major objective.
According to Baldhuri, when Qutayba ibn Muslim became the governor of Khorasan and Sistan, he appointed his brother 'Amr to Sistan. 'Amr asked the Zunbil to pay tribute in cash but he refused, prompting Qutayba to march against him. The campaign was also partially encouraged by his desire to eliminate the support of the southern Hepthalites, the Zabulites, for their northern brethren to revolt. Zunbil who was surprised by this unexpected move and scared of his reputation, quickly capitulated. Qutayba, realizing the real strength of the Zunbils, accepted it and returned to Merv, leaving only an Arab representative in Sistan.
Per Al-Mada'ini, Qutayba returned to Merv after conquering Bukhara in 709. The rebellion of the Hepthalite principalities from region of Guzgan including Taloqan and Faryab, led Qutayba to dispatch 12,000 men from Merv to Balkh in winter of 709. The rebellion was led and organized by Nizak Tarkhan and was supported by Balkh and Marw al-Rudh's dihqan Bādām. Nizak had realised that independence wouldn't be possible if Arab rule was strengthened in Khorasan, and perhaps was also encouraged by Qutayba's attempts to achieve his objectives through diplomacy. The success of Zunbils may also have encouraged him.
Nizak wrote to the Zunblis asking for help. In addition, he also forced the weak Jābghū of Tokharistan to join his cause to persuade all princes of the Principalities of Tukharistan to do the same. His plan to stage the revolt in spring of 710 was however spoilt by Qutayba. Badham fled when Qutayba advanced on Marw al-Rudh but his two sons were caught and crucified by Qutayba who next marched to Taloqan. Taloqan was the only place in his campaign where the inhabitants weren't given a complete amnesty, concerning which H.A.R. Gibb states the "traditions are hopelessly confused". Per one account, he executed and crucified a band of bandits there, though it is possible it was selected for this severity as it was the only place where there was an open revolt.
Faryab and Guzgan both submitted and their inhabitants were not harmed. From there he went on to receive the submission of people of Balkh. Almost all of Nizak's princely allies had reconciled themselves with him and there were Arab governors in all towns of Tokharistan, spoiling his plans. He fled south to the Hindu Kush, hoping to reach Kabul and entrenched himself in an inaccessible mountain pass guarded by a fortress. The Arabs succeeded in gaining the fort with help of Ru'b Khan, ruler of Ru'b and Siminjan. Nizak fled along the modern road that leads from the Oxus valley to Salang Pass and holed up in an unidentified mountain refuge in a site of Baghlan Province. Qutayba caught up with him and besieged him for two months.
Sulaym al-Nasih (the counsellor), a "mawla" of Khorasan, helped in obtaining his surrender to Qutayba who promised a pardon. Nonetheless, he was executed along with 700 of his followers after orders from al-Hajjaj. The Jabghu of Tokharistan was sent as a valuable hostage to Damascus. He then went in pursuit of Juzjan's king, who requested amnesty and called for exchange of hostages as precautionary measure. This was agreed upon and Habib b. 'Abd Allah, a Bahilite, was sent as prisoner by Qutayba while the king sent some of his family members in return. The peace treaty was agreed but the king died in Taloqan on his return journey. His subjects accused the Muslims of poisoning him and killed Habib, with Qutayba retaliating by executing Juzjan's hostages.
Tabari records that in 667 A.D., Ziyad b. Abihi had sent Hakam b. 'Amr al-Ghafri to Khorasan as Amir. Hakam raided Ghur and Farawanda, bringing them to submission through force of arms and conquered them. He obtained captives and a large amount of plunder from them. A larger expedition was undertaken under Asad ibn Abdallah al-Qasri, the governor of Khorasan, who raided Gharchistan in 725, receiving its submission as well as the conversion of its king to Islam. He next attacked Ghur whose residents hid their valuables in an inaccessible cave, but he was able to plunder the wealth by lowering men in crates.
Asad's success prompted him to undertake a second expedition in 108-109 A.H. against Ghur. The poet Thabit Qutna's eulogical poem of Asad recorded by Tabari called it a campaign against the Turks saying, "Groups of the Turks who live between Kabul and Ghurin came to you, since there was no place in which they might find refuge from you." Bosworth states that this campaign may have actually taken place in Guzgan or Bamiyan rather than the purely-Iranian Ghur. He also states that no doubt further sporadic raids continued throughout the Umayyad rule, though not noted by historians. It is known that Nasr ibn Sayyar's commander Sulaiman b. Sul had raided Gharchistan and Ghur some time before 739 A.D.
The early history of Ghor is unclear. Minhaj-i-Siraj in Tabaqat-i-Nasiri states that Shansab, who established the Ghurid dynasty, was converted by the Arab Caliph Ali which Mohammad Habib and K. A. Nizami dismissed as unlikely. He further adds that the Ghurid Amir Faulad assisted Abu Muslim in overthrowing the Umayyads during the Abbasid Revolution. He also recounts a legend about a dispute between two prominent families of the area. They sought the intercession of the Abbasids and the ancestor of the Shansabi family, Amir Banji, was subsequently confirmed as the ruler by Harun al-Rashid.
No permanent control was ever established on Ghur. According to Bosworth, its value was only for its slaves which could best be obtained in occasional temporary raids. Arab and Persian geographers never considered it important. In all sources it is cited as supplying slaves to slave markets in Khorasan, indicating it had a mostly "infidel" population. Istakhari called it a land of infidels ("dar al-kufr") annexed to Islamic domain because of its Muslim minority. However "Hudud al-'Alam" stated it had a mostly-Muslim population.
The pre-Ghaznavid royal dynasty of Ghazna were the Lawiks. Afghan historian 'Abd al-Hayy Habibi Qandahari who in 1957 examined a manuscript containing tales about miracles ("karamat") of "Shaikh" Sakhi Surur of Multan who lived in the 12th century, concluded it dated to 1500. He recorded one of its anecdotes which records history of Ghazna by the Indian traditionalist and lexicographer Radi ad-Din Hasan b. Muhammad al-Saghani [died 1252] from Abu Hamid az-Zawuli. According to it, a great mosque at Ghazna was earlier a great idol-temple built in honor of the Rutbils and Kabul-Shahs by Wujwir Lawik. His son Khanan converted to Islam and was sent a poem by the Kabul-Shah saying, "Alas! The idol of Lawik has been interred beneath the earth of Ghazna, and the Lawiyan family have given away [the embodiment of] their kingly power. I am going to send my own army; do not yourself follow the same way of the Arabs [ie., Islam]."
Habibi continues stating that Khanan later reconverted to the faith of the Hindu-Shahis. His grandson Aflah however upon assuming power demolished the idol-temple and built a mosque in its place. When the saint Surur arrived at the mosque, he is said to have found the idol of Lawik and destroyed it. The "Siyasatnama" of Nizam al-Mulk, the "Tabaqat-i Nasiri" of Juzjani and the "Majma' al-ansāb fī't-tawārīkh" of Muhammad Shabankara'i (14th century) mention Lawik. Juzjani gives the Lawik who was defeated by Alp-tegin the Islamic "kunya" of "Abu Bakr" though Shabankara'i claims he was a pagan. A variant of his name appears as Anuk in "Tabaqat-i Nasiri".
Ya'qubi states that lord of Bamyan called the "Shēr", was converted to Islam under Caliph Al-Mansur (d.775) by Muzahim b. Bistam who married his son Abu Harb Muhammad to his daughter. However, in his history he changes it to the rule of Al-Mahdi (r. 775–785). Ya'qubi also states that Al-Fadl ibn Yahya made Hasn, Abu Harb Muhammad's son, as the new "Shēr" after his successful campaign in Ghorband. Ya'qubi states that the ruler of Bamiyan had accompanied an expedition dispatched by Al-Fadl ibn Yahya in 792–793 against Kabul Shahi.
Later Shers remained Muslim and were influential at the Abbasid court. However, Muslim sources describe the Saffarid ruler Ya'qub ibn al-Layth al-Saffar looting Bamiyan's pagan idols. A much later historian Shabankara'i claims that Alp-Tegin obtained conversion of Sher to Islam in 962. It seems there were lapses to Buddhism among some of the rulers as the Muslim influence grew weak. However, there is no evidence about the role of Buddhism during these periods or whether Buddhist monasteries remained the center of religious life and teaching.
Khurasan was the base for early recruitment of Abbasid armies, especially the Abbasid takeover received support from Arab settlers aiming to undermine the important sections of non-Muslim aristocracy. The Abbasids succeeded in integrating Khorasan and the East into the central Islamic lands. The state was gradually Persianized through political influence and financial support of the "dihqans". Al-Ma'mun emerged as the victor in Fourth Fitna with the help of Khorasani forces. But this also ended up turning the province into a virtually independent state under the Tahirids, founded by a Persian "mawla" who rose to favour under Al-Ma'mun.
According to Ibn Khordadbeh, the Shah of Kabul had to send 2,000 Oghuz slaves worth 600,000 dirhams as annual tribute to the governor of Khorasan Abdallah ibn Tahir (828-845). In addition to the Oghuz slaves, he also had to pay an annual tribute of 1.5 million dirhams. Mid-9th century, one of their tributaries Abu Da'udid or Banijurid Amir Da'ud b. Abu Da'ud Abbas, undertook an obscure campaign into eastern Afghanistan and Zabulistan that was profitable. It is recorded that in 864 Muhammad ibn Tahir sent two elephants captured at Kabul, idols and aromatic substances to the caliph.
The Tahirid rule was overthrown by Ya'qub ibn al-Layth al-Saffar of Sistan, the first independent Iranian ruler in the post-Islamic era and fought the Abbasid Caliphate. He joined the 'ayyar band of Salih b. al-Nadr/Nasr, who was recognised as Bust's amir in 852. al-Nasr aimed at taking over whole of Sistan and drove out the Tahirid governor in 854, with Sistan ceasing to be under direct control of the Caliphate. al-Nasr himself was overthrown by Dirham b. Nasr who was overthrown by Ya'qub in 861. Ya'qub and his brother Amr advanced as far as Baghdad and to Kabul itself in eastern Afghanistan with their dynamism, advancing along the historic route taken by the modern Lashkargah-Qandahar-Ghazni-Kabul road. Their eastern campaigns are documented by Arabic sources of Al-Masudi's "Murūj adh-dhahab", Ibn al-Athir's "al-Kāmil fi't-tā'rīkh" and "Tarikh-e-Sistan". The Persian historian Gardizi's "Zain al-akhbār" also mentions the Saffarid campaigns.
Salih fled to ar-Rukhkhaj or Arachosia, where he received the help of the Zunbil. Both Salih and the Zunbil were killed by Ya'qub in 865. Abu Sa'id Gardezi mentions that Ya'qub advanced from Sistan to Bust and occupied the city. From here he advanced to Panjway and Tiginabad (two of the chief towns of Arachosia), defeating and killing the Zunbil, though the date isn't given. This account matches with that of "Tarikh-e-Sistan". Satish Chandra states that, "We are told that it was only in 870 AD that Zabulistan was finally conquered by one Yakub who was the virtual ruler of the neighbouring Iranian province of Siestan. The king was killed and his subjects were made Muslims."
Muhammad Aufi's "Jawami ul-Hikayat" meanwhile states that during his invasion of Zabul, he employed a ruse to surrender after being allowed to pay homage to the ruler along with his troops lest they disperse and become dangerous to both sides. Yaqub's troops "carried their lances concealed behind their horses and were wearing coats of mail under their garments. The Almighty made the army of Rusal (probably Rutbil), blind, so that they did not see the lances. When Yaqub drew near Rusal, he bowed his head as if to do homage, but raised a lance and thrust it in the back of Rusal so that he died on the spot. His people also fell like lightning upon the enemy, cutting them down with their swords and staining the earth with the blood of the enemies of the religion. The infidels when they saw the head of Rusal upon the point of a spear took to flight and great bloodshed ensued. This victory, which he achieved, was the result of treachery and deception, such as no one had ever committed."
Ashirbadi Lal Srivastava states that after this victory by Yaqub over Zabul, the position of Lallya alias Kallar, the Brahmin minister who had overthrown the last Kshatriya king of Kabul Lagaturman, seems to have become untenable. He shifted his capital to Udhaband in 870 A.D. Lallya, credited as an able and strong ruler by Kalhana in "Rajatarangini", was driven out by Ya'qub from Kabul within a year of his usurpation according to Srivastava.
Gardezi states that after defeating Zunbil, he then advanced into Zabulistan and then Ghazna, whose citadel he destroyed and forced Abu Mansur Aflah b. Muhammad b. Khaqan, local ruler of nearby Gardez, to tributary status. "Tarikh-e-Sistan" however in contrast states that he returned to Zarang after killing Salih. This campaign may be related to Gardizi's account of later expedition in 870 where he advanced as far as Bamiyan and Kabul. Salih b. al-Hujr, described as a cousin of the Zunbil, was appointed as the Saffarid governor of ar-Rukhkhaj, but rebelled two years after Zunbil's death and committed suicide to avoid capture.
Ya'qub had captured several relatives of the Zunbil's family after defeating Salih b. al-Nasr. Zunbil's son escaped from captivity in 869 and quickly raised an army in al-Rukhkhaj, later seeking refuge with the Kabul-Shah. Per Gardizi, Ya'qub undertook another expedition in 870 which advanced as far as Kabul and Bamiyan. According to "Tarikh-e-Sistan", Bamiyan was captured in 871. He wrested Bamiyan from its ruler, the "Sher", and plundered its idol-temple. He defeated Kabul in 870 and again had to march to there in 872 when Zunbil's son took possession of Zabulistan. Ya'qub captured the Zunbil's son from the fortress of Nay-Laman where he had fled. In 871, Ya'qub sent 50 gold and silver idols he gained by campaigning from Kabul to Caliph Al-Mu'tamid, who sent them to Mecca.
According to Tabaqat-i-Nasiri, Ghor which was ruled by Amir Suri in the 9th century entered into a war against him, but escaped conquest due to its difficult and mountainous terrain.
After Ya'qub's death in 879, Al-Mu'tamid recognised his brother and successor 'Amr b. al-Layth (r. 879–902), as governor of Khorasan, Isfahan, Fars, Sistan and Sindh. The caliph however announced divesting him of all his governorships in 885 and reappointed Muhammad b. Tahir as the governor of Khorasan. He was reappointed governor of Khorasan in 892 by Al-Mu'tadid.
Amr led an expedition as far as Sakawand in the Logar valley, between Ghazna and Kabul, described as a Hindu pilgrimage-centre. In 896, he sent idols captured from Zamindawar and the Indian frontier, including a female copper idol with four arms and two girdles of silver set with jewels pulled on a trolley by camels, to Baghdad. Al-Baihaki mentions Sakawand as a pass from Kabul to India. It was situated at or near Jalalabad. The idol taken from somewhere in eastern Afghanistan by Amr was displayed for three days in Basra and then for three days in Baghdad. Jamal J. Elias states that it may have been of Lakshmi or Sukhavati at Sakawand. Al-Masudi emphasises the attention it received as a spectacle, with crowds gathering to gawk at it.
Aufi states that Amr had sent Fardaghan as the prefect over Ghazna and he launched the raid on Sakawand, which was a part of the territory of Kabul Shahi and had a temple frequented by Hindus. The Shah of Kabul at this time was Kamaluka, called "Kamalu" in Persian literature. Fardaghan entered it and succeeded in surprising Sakawand. Sakawand was plundered, and its temple destroyed.
Kamalu counter-attacked Fardaghan who realising his forces were no match for his, resorted to spreading a false rumour that he knew his intentions and had organised a formidable army against him with 'Amr on the way to join him. The rumour had the desired effect and the opposing army slowed its advance knowing that they could be ambushed and slaughtered if they advanced impetuously into the narrow defiles. Meanwhile, Fardaghan received reinforcements from Khorasan according to Aufi. According to Aufi he cleverly averted the danger.
"Tarikh-e-Sistan" doesn't mention any attack by Fardaghan on Sakawand however, instead beginning with the attack by Kamalu. Per it, when Amr was in Gurgan, he heard that "Nasad Hindi" and "Alaman Hindi" had allied and invaded Ghazna. The Saffarid governor 'Fard 'Ali was defeated and fled.
The Samanids came to rule over areas including Khorasan, Sistan, Tokharistan and Kabulistan after Ismail (r. 892907) in 900 A.D. had defeated the Saffarids, who had taken over Zabulistan and the Kabul region. The Turks were highly noted for their martial prowess by the Muslim sources and were in high demand as slave-soldiers ("ghulam", "mamluk") by the Caliphate in Baghdad and the provincial emirs. The slaves were acquired either in military campaigns or through trade. The Samanids were heavily involved in this trade of Turkish slaves from lands to the north and east of their state. As the enslavement was limited to non-Muslims and with the Turks increasingly adopting Islam beyond Samanid borders, they also entered Transoxiana as free men due to various causes.
The Ghaznavids arose indirectly from the atmosphere of disintegration, palace revolutions and succession putschs of the Samanid Empire. Abu-Mansur Sabuktigin was one of the Samanid slave guards who rose from the ranks to come under the patronage of the Chief "Hajib" Alp-Tegin. After the death of the Samanid Amir 'Abd al-Malik b. Nuh, the commander of forces in Khorasan Alp-Tegin along with the "vizier" Muhammad Bal'ami attempted to place a ruler of their choice on the throne. The attempt failed however and Alp-Tegin decided to withdraw to the eastern fringes of the empire. Per the sources, he wanted to flee to India to avoid his enemies and earn divine merit by raiding the Hindus. He didn't intend to capture Ghazna, but was forced to take it when denied transit by its ruler.
Alp-Tegin proceeded with his small force of "ghulams" and "ghazis" (200 ghulams and 800 ghazis according to "Siyasatnama", while "Majma al-ansab" of Muhammad b. Ali al-Shabankara'i (d. 1358) states 700 ghulams and 2,500 Tajiks). En route, he subdued the Iranian "Sher" of Bamiyan and the Hindu-Shahi king of Kabul. He then came to Ghazna whose citadel he besieged for four months and wrested the town from its ruler, Abu 'Ali or Abu Bakr Lawik or Anuk. The origin of this chief was Turkic, though it is not known if he was a Samanid vassal or an independent ruler. Josef Markwart suggests he was a late representative of the Zunbils. The Lawik dynasty of Ghazna was linked to the Hindu-Shahi dynasty through marriage. Alp-Tegin was accompanied by Sabuktigin during the conquest of Ghazna.
Minhaj al-Siraj Juzjani states that Alp-Tegin had his position regularised by Amir Mansur b. Nuh through an investiture, however "Siyasatnama" mentions an expedition against Alp-Tegin from Bukhara which was defeated outside Ghazna. His ambiguous, semi-rebel status seems to be reflected in his coins, with two of his coins minted at Parwan mentioning his authority from the Samanids to mint coins only in an indirect way. He was succeeded by his son Abu Ishaq Ibrahim, who lost Ghazna to Abu Ali Lawik, the son of its expelled ruler. He recovered it however with Samanid help in 964–65.
Alp-Tegin's ghulams were reconciled with the Samanids in 965 but maintained their autonomy. After Ibrahim's death in 966, Bilge-Tigin was made the successor and he acknowledged the Samanids as his overlords. He died in 976 and was succeeded by Böritigin or Piri. Piri's misrule led to resentment among the people who invited Abu Ali to take back the throne. The Kabul Shahis allied with him and the king, most likely Jayapala, sent his son to assist Lawik in the invasion. When the allied forces reached near Charkh on Logar River, they were attacked by Sabuktigin who killed and captured many of them while also capturing ten elephants. Piri was expelled and Sabuktigin became governor in 977 A.D. The accession was endorsed by the Samanid ruler Nuh II.
The Hudud al-‘Alam states Ghor was under the overlordship of Farighunids. Both Gardezi and Baihaqi state in 379 A.H. (979–980 A.D.), the Samanid Amir Nuh b. Mansur despatched an expedition under Abu Ja'far Zubaidi to conquer Ghur but he had to return after capturing several forts. As the Samanid governor of Zabulistan and Ghazni, Sabuktigin attacked it several times. He was able to conquer eastern Ghur after initial set-backs and was acknowledged as a sovereign by Muhammad ibn Suri.
The Ghaznavid campaigns from the time of Sabuktigin are recorded as "jihad" against the people of "al-Hind" to destroy idolatry and replace it by expanding Islam. The Kabul Shahis only retained Lamghan in the Kabul-Gandhara area by the time of Alp-tegin. According to Firishta, Sabuktigin had already begun raiding Lamghan under Alp-tegin. This precipitated an alliance between the Shahi ruler Jayapala and the Muslim Amirs of Multan. He crossed the Khyber Pass many times and raided the territory of Jaipala.
Sabuktigin plundered the forts in the outlying provinces of the Kabul Shahi and captured many cities, acquiring huge booty. He also established Islam at many places. Jaipal in retaliation marched with a large force into the valley of Lamghan (Jalalabad) where he clashed with Sabuktigin and his son. The battle stretched on several days until a snow storm affected Jaipala's strategies, forcing him to plead for peace. He was inclined to grant peace to Jayapala but his son Mahmud wanted total victory.
Jaypala upon hearing Mahmud's plans warned, "You have seen the impetuosity of the Hindus and their indifference to death... If therefore, you refuse to grant peace in the hope of obtaining plunder, tribute, elephants and prisoners, then there is no alternative for us but to mount the horse of stern determination, destroy our property, take out the eyes of our elephants, cast our children into fire, and rush out on each other with sword and spear, so that all that will be left to you to conquer and seize is stones and dirt, dead bodies, and scattered bones." Knowing he could carry it out, Sabuktigin granted him peace on promise of paying tribute and ceding some of his territory.
After making peace with Sabuktigin, Jayapala returned to Waihind but broke the treaty and mistreated the amirs sent to collect the tribute. Sabuktigin launched another invasion in retaliation. While the mamluks remained the core of his army, he also hired the "Afghans", especially the Ghilji tribe, in his dominion. According to al-Utbi, Sabuktigin attacked Lamghan, conquering it and burning the residences of the "infidels" while also demolishing its idol-temples and establishing Islam. He proceeded to butcher the idolaters, destroyed their temples and plundered their shrines. It is said his forces even risked frostbite on their hands while counting the large booty.
To avenge the savage attack of Sabuktigin, Jayapala, who had earlier taken his envoys as hostage, decided to go to war again in revenge. According to al-Utbi, he assembled an army of 100,000 against Sabuktigin. The much later account of Ferishta states that it included troops from Kanauj, Ajmer, Delhi and Kalinjar. The two sides fought an open battlefield in Laghman. Sabuktigin divided his army into packs of 500 who attacked the Indians in succession. After sensing that they were weakened, his forces mounted a concerted attack. The forces of Kabul Shahi were routed and those still alive were killed in the forest or drowned in the river.
The second battle that took place between Sabuktigin and Jayapala in 988 A.D., resulted in the former capturing territory between Lamghan and Peshawar. Al-Utbi also states that the Afghans and Khaljis, living there as nomads, took the oath of allegiance to him and were recruited into his army. He helped Nuh II in expelling the rebel and heretic Abu Ali Simjur from Khorasan, resulting in its governorship being given to Sabuktigin who appointed Mahmud as his deputy there. He appointed Ismail as successor to his kingdom and died in 997. A succession war erupted between Ismail and Mahmud, with the latter gaining the throne in 998.
The Samanid amir Mansur II appointed Bektuzun as Khorasan's governor after Sabuktigin's death. Mahmud however wished to reacquire the governorship after defeating his brother Ismail and his allies. Bektuzun and Fa'iq, the "de facto" power behind the Samanid throne, toppled Mansur II as they did not trust him and replaced him with Abu'l Fawaris 'Abd al-Malik. Their forces were however defeated in 999 by Mahmud, who acquired all the lands south of Oxus with even those to the north of the river submitting to him. The Samanid dynasty was later ended by the Karakhanids. In 1002, Mahmud also defeated the Saffarid Amir Khalaf ibn Ahmad and annexed Sistan.
Mahmud systemized plunder raids into India as a long-term policy of the Ghaznavids. The first raid was undertaken in September 1000, but was meant for reconnaissance and identifying the possible terrain and roads that could be used for future raids. He reached Peshawar by September 1001 and was attacked by Jayapala. The two sides clashed on 27–28 November 1001 with Jayapala captured. Anandapala who was at Waihand had to pay a heavy ransom to have his father and others released. Jaypala self-immolated out of shame and Anandpala succeeded him. Mahmud attacked Anandpala later over his refusal to allow him passage during the attack on Multan controlled by Fateh Daud. The two sides clashed in 1009 in the eastern side of Indus at Chhachh, with Mahmud defeating Anandapala and capturing the fort of Bhimnagar. He was allowed to rule as a feudatory in Punjab for some time.
An alliance between Anandpala's son, Trilochanpala, and Kashmiri troops was defeated. During the warfare from 990–91 to 1015, Afghanistan, and later Punjab and Multan were lost to the Ghaznavids. Trilochanpala's rule was limited to eastern Punjab and he gained respite from the Muslim invasions with retreat to Sirhind. He allied with the Chandellas
and in 1020-21 was defeated at a river called Rahib by Al-Utbi, while Firishta and Nizamuddin Ahmad identify it as Yamuna. He was killed in 1021 A.D. by his mutinous troops and succeeded by Bhimapala. Bhimapala who was the last ruler, was killed fighting the Ghaznavids in 1026 A.D. The remnants of the royal family sought refuge with the Lohara dynasty of Kashmir and Punjab passed under the control of Muslim conquerors.
Mahmud used his plundered wealth to finance his armies which included mercenaries. The Indian soldiers, presumably Hindus, who were one of the components of the army with their commander called "sipahsalar-i-Hinduwan" lived in their quarter of Ghazna practicing their own religion. Indian soldiers under their commander Suvendhray remained loyal to Mahmud. They were also used against a Turkic rebel, with the command given to a Hindu named Tilak according to Baihaki.
The renowned 14th-century Moroccan Muslim scholar Ibn Battuta remarked that the Hindu Kush meant the "slayer of Indians", because slaves brought from India who had to pass through there died in large numbers due to the extreme cold and quantity of snow. He states:
The conversion of Ghur occurred over a long period and it was mostly pagan until the 10th century, which Mohammad Habib and Khaliq Ahmad Nizami say was probably a result of the missionary activities by the Karramiyya movement established in the region in 10th-11th centuries. Its imperfect conversion is visible by the fact that while the people of Ghur had Muslim names, they led the life of pagans. Muhammad b. Suri who had acknowledged Sabuktigin as his sovereign, withheld tribute after his death, started plundering caravans and harassed the subjects of Sultan Mahmud. Rawżat aṣ-ṣafāʾ called him a pagan, al-Utbi stated he was a Hindu.
In 1011, Mahmud despatched an expedition to conquer Ghur under Altuntash, governor of Herat, and Arslan Hajib, governor of Tus. Muhammad b. Suri, the king, placed himself in inaccessible hills and ravines. The Ghurids were however defeated and Suri was captured along with his son Shith. Abu Ali, who had remained on good terms with the Sultan, was made the ruler of Ghur by him. Eastern Ghur was brought under Ghaznavid control. In 1015, Mahmud attacked Ghur's southwestern district of Khwabin and captured some forts.
In 1020, Mahmud's son Ma'sud was despatched to take Ghur's northwestern part called Tab. He was helped by Abul Hasan Khalaf and Shirwan, chieftains of the south-western and north-eastern regions respectively. He captured many forts, bringing entire Ghur except maybe the inaccessible interior under Ghaznavid control. He also captured the stronghold of the chieftain Warmesh-Pat of Jurwas, levying a tribute of arms. Minhaj al-Siraj Juzjani praises Abu Ali for firmly establishing Islamic institutions in Ghur. The progress of Islam in this divided region after his death is however unknown.
Ghur remained a pagan enclave until the 11th century. Mahmud who raided it, left Muslim precepts to teach Islam to the local population. The region became Muslim by 12th century though the historian Satish Chandra states that Mahayana Buddhism is believed to have existed until the end of the century. Neither Mahmud nor Ma'sud conquered the interior. Habib and Nizami say Ghurids were gradually converted by propagandists of new mystic movements. The Shansabani succeeded in establishing their seniority, if not its unification. By the time of Sultan Bahram, Ghur was converted and politically unified. According to Minhaj, both Ghiyasuddin and Mu'izzuddin were Karamis who later converted to Shafi‘i and Hanafi Islam respectively. The Tarikh-i guzida however says the Ghorids were only converted to Islam by Mahmud.
The name "Afghanistan" was first used in a political sense by Saifi Herawi in the 14th century. It was even used during the height of the Durrani Empire. Only after the Durand line was fixed, did its modern usage for the land between it and the Oxus river became usual. The people who were mostly responsible for establishing the Afghan kingdom are referred to as "Pashtun". The name "Pashtun" (or "Pakthun") is the original and oldest name.
The tenth-century Persian geography "Hudud al-'Alam" is the earliest known mention of the Afghans. In "Discourse on the Country of Hindistan and Its Towns", he states that, "Saul, a pleasant village on a mountain. In it live Afghans." Ibn Battuta described Saul being situated between Gardez and Husaynan along a common trade route, the exact location of Husaynan is unknown. Akhund Darweza states their original homeland was Qandahar from where they migrated in 11th century upon Mahmud of Ghazni's request to assist him in his conquests. Afghan tradition considers "Kase Ghar" in Sulayman range as the homeland. "Hudud al-'Alam" also mentions that the king of Ninhar (Nangarhar) had many wives including "Moslem, Afghan and Hindu".
The Pashtun traditions speak of Islamization during Muhammad's time through Khalid ibn Walid. Qais Abdur Rashid, the presumed ancestor of the Afghans, is said to have led a delegation to Mecca from Ghor after being summoned by Khalid b. Walid and converted to Islam while also distinguishing himself in the service of the prophet. Adopting the name Abdul Rashid, three sons - Saraban, Ghurghust, Karlani, and a foundling Karlanri linked to Saban, are the progenitors of the major Afghan divisions.
Ni'matullah's "Makhzan-i-Afghani" traces their history to an Israelite called Afghana who constructed the al-Aqsa mosque. Per it under the time of King Suleiman, a figure named Bokhtnasser was responsible for "carrying away the Israelites, whom he settled in the mountainous districts of Ghor, Ghazneen, Kabul, Candahar, Koh Firozeh, and the parts lying within the fifth and sixth climates; where they, especially those descended of Asif and Afghana, fixed their habitations, continually increasing in number, and incessantly making war on the infidels around them." Qais traveled to Medina to receive Mohammed's blessings and fought against the Meccans. Muhammad himself conferred the title of "Pashtun" upon Qais and his people. They returned to Ghor to spread Islam and pledged loyalty to Mahmud. Per Ni'matullah, the Ghurid ruler Mu'izz al-Din had initiated their eastward migration into present-day north-west Pakistan, in course of his military campaigns.
The Arabs, at war with the Kabul Shah, had directed their campaigns in direction of Gandhara. By the time of Muawiya, Sistan's governorship was separated from Khorasan with the governor looking after the region and keeping a check on Kabul Shah. Ahmed Hassan Dani considers that the Arab activities may have led to conversion of Aghans as well, and it may have been wholesale because of their tribal nature ie., all the Afghan tribes adopted Islam at once.
Quoting "Matla-al-Anwar", Ferishta states a man named Khalid, son of Abdullah, stated by some to be a descendant of Khalid bin Walid or Abu Jahl, was for some time governor of Herat, Ghor, Gharjistan and Kabul. After being relieved of the charge, he settled in Koh Sulaiman, with the Lodis and Suris being the descendant of his daughter who married a converted Afghan. Only he continues with Afghan history after this. He states that the Hindu Shahi king gave them a few villages in Laghman in return for guarding against the Arabs. He adds that after being unable to withstand Sabuktigin's raids, Jaipala appointed the Afghan Shiekh Hamid Lodhi to an "Amirate" but Lodhi was removed after Sabuktigin became supreme in Ghazni. Ferishta speaks of the Afghans here as Muslims.
Al-Utbi in "Tarikh-i-Yamini" states that the Afghans were enlisted by Sabuktigin and also Mahmud. During this period, the Afghan habitat was in the Sulaiman Mountains. After defeating Jayapala in 988 A.D., Sabuktigin had acquired the territory between Laghman and Peshawar. Al-Utbi states that the Afghans and Khaljis, living there as nomads, took the oath of allegiance to him and were recruited into his army. Iqtidar Husain Siddiqui citing a 13th century Persian translation, claims he mentions the "Afghans" were pagans given to rapine and rapacity, they were defeated and converted to Islam.
Writing in the 11th century AD, Al-Biruni in his "Tarikh al Hind", stated that the Afghan tribes lived in mountains west of India. He notes, "In the western frontier mountains of India there live various tribes of the Afghans and extend up to the neighbourhood of the Sindu valley."
Mahmud had gone to war against pagan Afghan while campaigning in the Sulayman mountains. Firishta states that Afghans fought on both sides during the war between Mu'izz al-Din and Pithorai in 1192 AD, which Encyclopaedia of Islam says probably indicating they weren't completely converted.
In 1519, Babur mounted an attack on the fort of Bajaur and sent a Dilazak Afghan as an ambassador to the Gibri Sultan of Bajaur, Mir Haidar 'Ali, to surrender and enter his services. Gibri, a Dardic language of Bajaur, was also spoken by the royal family and nobility of the Swat Valley. The Gibris decided to resist and Babur's forces stormed it in two days. He ordered a general massacre of its inhabitants on the pretext that they had rebelled against Kabul's regime and were infidels who had forsaken Islam.
The westward migration of Pashtuns from Sulaiman mountains to Qandahar and Herat is thought to have begun in the 15th century. In the 16th century, the area around Qandahar formed a bone of contention between Ghilzai and Abdalis. The latter gave in and migrated to Herat during the reign of Safavid Shah Abbas I. Their migration displaced or subjugated the indigenous populations especially the Tajiks who were also the dominant population in Kabul, Nangarhar and Laghman in east Afghanistan. Before advent of Ghilzais of the Ahmadzai division in the late 16th century, Logar River was also a Tajik stronghold. The Pashtuns also displaced the original Kafirs and Pashayi people in Kunar Valley and Laghman valley, located south of Kabul in east Afghanistan, to the infertile mountains. Regions to south and east of Ghazni were stronghold of Hazaras before the 16th century. They also lost Wardak to the tribe of the same name when the latter invaded in the 17th century. In Qandahar, the Farsiwanis, Hazaras, Kakars and Baloch people were subjugated.
Kafiristan is a mountainous region of the Hindu Kush that was isolated and politically independent until the Afghan conquest of 1896. Before their conversion to Islam, the Nuristanis or Kafir people practiced a form of ancient Hinduism infused with locally developed accretions.
Kafiristan proper from west to east comprises basins of Alishang, Alingar, Pech or Prasun, Waigal and Bashgal. The region became a refuge of an old group of Indo-European people probably mixed with an older substratum, as well as a refuge of a distinct Kafiri group of Indo-Iranian languages, forming part of the wider Dardic languages. The inhabitants were known as "kafirs" due to their enduring paganism while other regions around them became Muslim. However, the influence from district names in Kafiristan of Katwar or Kator and the ethnic name Kati has also been suggested. The Kafirs were divided into Siyah-Posh, comprising five sub-tribes who spoke Kamkata-vari language while the others were called Safed-Posh comprising Prasungeli, Waigeli, Wamai and Ashkun.
The Kafirs called themselves "Balor", a term that appeared in Chinese sources as early as the fifth century A.D. Both Chinese sources and Muslim sources like the 16th-century work of Kashmir's conqueror Mirza Muhammad Haidar Dughlat, the terms "Bolor" and "Boloristan" denote the area from the Kabul valley to Kashmir, Yarkand and Kashgar. The country is the most inaccessible part of Hindu Kush. The Muslim conquerors could not achieve a lasting success here.
The vast area extending from modern Nuristan to Kashmir (styled "Peristan" by A. M. Cacopardo) containing host of "Kafir" cultures and Indo-European languages that became Islamized over a long period. Earlier, it was surrounded by Buddhist areas. The Islamization of the nearby Badakhshan began in the 8th century and Peristan was completely surrounded by Muslim states in the 16th century with Islamization of Baltistan. The Buddhist states temporarily brought literacy and state rule into the region. The decline of Buddhism resulted in it becoming heavily isolated.
There have been varying theories about the origins of the Kafirs. Oral traditions of some Nuristanis place themselves to be at confluence of Kabul and Kunar River a millennium ago, being driven off from Kandahar to Kabul to Kapisa to Kama with the Muslim invasion. They identify themselves as late arrivals here, being driven by Mahmud of Ghazni who after establishing his empire forced the unsubmissive population to flee. George Scott Robertson considered them to be part of the old Indian population of Eastern Afghanistan and stated they fled to the mountains while refusing to convert to Islam after the Muslim invasion in the 10th century. The name Kator was used by Lagaturman, last king of the Turk Shahi. The title "Shah Kator" was assumed by Chitral's ruler Mohtaram Shah who assumed it upon being impressed by the majesty of the erstwhile pagan rulers of Chitral. The theory of Kators being related to Turki Shahis is based on the information of "Jami- ut-Tawarikh" and "Tarikh-i-Binakiti". The region was also named after its ruling elite. The royal usage may be the origin behind the name of Kator.
In 1020–21, Sultan Mahmud of Ghazna led a campaign against Kafiristan and the people of the "pleasant valleys of Nur and Qirat" according to Gardizi. The Persian chronicles speak of Qirat and Nur (or Nardin) which H. M. Elliot on authority of Al-Biruni identifies with Nur and Kira tributaries of Kabul river. Ferishta wrongly calls these two valleys as "Nardin" and Qirat and confuses this conquest with the one against "Nardin" or Nandana. He also wrongly mentions it took place after 412 A.H. Alexander Cunningham identifies the places conquered as "Bairath" and "Narayanpura".
These people worshipped the lion. While Clifford Edmund Bosworth considers that Mahmud attacked "pagan Afghans", Joseph Theodore Arlinghaus of Duke University doesn't consider it correct because his source Gardezi simply calls them "pagan (kafiran)" and not "pagan Afghans", as they weren't known to be pagan or live on borders of Nuristan in the 11th century. Mohammad Habib however considers they might have been worshipping Buddha in form of a lion ("Sakya Sinha"). Ramesh Chandra Majumdar states they had a Hindu temple which was destroyed by Mahmud's general. Ram Sharan Sharma states that they may have been Buddhist. Cunningham claims based on the reporting of Ferishta that the place was plundered by 'Amir Ali after being taken.
According to Gardezi, while returning from invasion of India, he had heard about them and the chief of Qirat surrendered without any struggle and accepted to convert, with the inhabitants converting as well. Nur however refused to surrender and his general 'Amir Ali led an attack on it and forcing its people to convert. According to Firshta, the rulers of both of them submitted and accepted Islam in 1022. He adds, "On breaking a great temple situated there, the ornamented figure of a lion came out of it, which according to the belief of the Hindus was four thousand years old."
However, no permanent conquest was attempted. "Iqbal namah-i-Jahangiri" stated that Kafirs still lived in Darrah-i-Nur Sultan Mahmud of Ghazni claimed to have converted. Mughal Emperor Jahangir had received a delegation of these pure Kafirs in Jalalabad and had honored them with gifts.
The campaigns of Timur are recorded by Zafarnama written by Sharaf ad-Din Ali Yazdi, based on another work.
On his way to India, Timur attacked the Siyah-Posh in 1398 A.D. after receiving complaints from the trading city of Andarab by raids from Kafirs. He penetrated it from Khawak pass and restored an old fortress there. He personally proceeded against the Kator region which extended from Kabul to Kashmir.
Timur sent a detachment of 10,000 soldiers against Siyah-Poshas under Burhan Aglan and had the fort of Kator deserted by Kafirs destroyed while the houses of the city were burnt. The infidels took refuge on top of a hill and many were killed in the ensuing clash. Some held out for three days but agreed to convert after Timur offered them the choice between death and Islam. They however soon apostatised and ambushed Muslim soldiers in the night. They were however repelled and a number of the Kafirs were killed, with 150 taken prisoner and later executed. Timur ordered his men "to kill all the men, to make prisoners of women and children, and to plunder and lay waste all their property." His soldiers carried out the order and he directed them to build a tower of skulls of the dead Kafirs.
Timur had his expedition engraved on a neighboring hill in the month of Ramazan. His detachment sent against Siyah-Poshas however met with disaster with Aglan routed and fleeing. A small detachment of 400 men under Muhammad Azad was sent and defeated the Kafirs, retrieving the horses and armour Aglan lost. Timur later captured a few more places, though nothing more is stated, presumably he left the Siyah-poshas alone. He proceeded to exterminate the rebellious Afghan tribes and crossed the Sindhu River in September 1398.
The Timurid Sultan Mahmud Mirza is said to have raided Kafiristan twice by "Baburnama", which earned him the title of "ghazi".
Mirza Muhammad Haidar Dughlat invaded Balor under orders of Sultan Said Khan in 1527-1528 A.D. and was accompanied by Khan's eldest son Rashid Khan. The expedition was an Islamic frontier raid or "ghaza". Dughlat undertook highly devastating plundering raids on Bolor.
Rashid Khan (r. 1533–1569) undertook further expeditions against Bolor (Kafiristan) which are recorded by "Tarikh-i-Kashgar" and "Bahr al-asar" of Mahmud b. Amir Wali. The Kashgari author mentions it briefly though Wali goes into detail. The first campaign failed with a number of Kashgari captured and enslaved by the people of Bolor. A second invasion was successful and forced them to submit. "Tarikh-i-Kashgar" states that Bolor was governed by Shah Babur after Abdullah Khan's successful campaign in 1640.
Babur writing in his memoirs notes that when he captured Chigha Sarai in 1514, the "Kafirs of Pech came to their assistance." He mentions some Muslim "nīmčas" or half-breeds, probably converted Kafirs, who married with the Kafirs and lived at Chigha Sarai, located at confluence of Kunar River and Pech River.
Babur himself came to the region in the winter of 1507–1508 and had an inscription carved commemorating his transit. While fleeing to India to take refuge in Afghan-Indian borderlands after Shibani Khan attacked Qandahar, which Babur had recently conquered, he marched from Kabul to Lamghan in September 1507. He eventually reached Adinapur fort in Nangarhar district. He comments that his men had to forage for food and raided the rice fields of the Kafirs in the Alishang district. In 1520, he mentions sending Haidar Alamdar to the Kafirs who returned and met him under Bandpakht along with some Kafir chiefs who gifted Babur some skins of wine.
The relationship of the Siahposh and residents of Panjshir and Andarab remained the same even more than a century after Timur's expedition. Babur records about Panjshir that, "It lies upon the road, and is in the immediate vicinity of Kafiristan. The inroads of the robbers of Kafiristan are made through Panjshir. In consequence of their vicinity of the Kafirs - the inhabitants of this district are happy to pay them a fixed contribution. Since I last invaded Hindustan, and subdued it (in 1527), the Kafirs have descended into Panjshir, and returned after slaying a great number of people and committing extensive damages."
Per "Tabakat-i-Akbari", Mughal Emperor Akbar had dispatched his younger brother Mirza Muhammad Hakim, who was a staunch adherent of the missionary-minded Naqshbandi Sufi order, against the infidels of Katwar in 1582. Hakim was a semi-independent governor of Kabul. The "Sifat-nama-yi Darviš Muhammad Hān-i Ğāzī" of Kadi Muhammad Salim who accompanied the expedition mentions its details. The "Sifat-nama" gives Muhammad Hakim the epithet of "Darviš Khan Gazi".
Muhammad Darvish's religious crusade fought its way from Lamghan to Alishang, and is stated to have conquered and converted 66 valleys to Islam. After conquering Tajau and Nijrau valleys in Panjshir area, the crusaders established a fort at Islamabad at confluence of Alishang and Alingar rivers. They continued the raid up to Alishang and made their last effort against the non-Muslims of Alingar, fighting up to Mangu, the modern border between Pashai and Ashkun-speaking areas.
The conquest doesn't seem to have had a lasting effect as Henry George Raverty mentions that Kafirs still lived in upper part of Alishang and Tagau. "Khulasat al-ansab" of Hafiz Rahmat Khan stated that the Afghans and Kafirs of Lamghan were still fighting each other during the time of Jahangir.
Under Amir Sher Ali Khan, Afghanistan was divided into provinces ("wilayats") of Kabul, Kandahar, Herat and Afghan Turkestan. Uruzgan and Kafiristan were later incorporated into Kabul. Some parts of Kafiristan were already following Islam before its conquest. Amir Abdul Rahman Khan tried to persuade them to convert to Islam by deputing Kafir elders. The Kafirs were poorly armed as compared to Afghans and numbered only 60,000. By 1895, demarcation of nearby Chitral under indirect British rule and conquest of Pamirs by Russia worried him about the endangerment of integration of Afghanistan through the independent Kafiristan. Afghan tribes meanwhile undertook slave raids in places like Kafiristan, Hazarajat, Badakhshan and Chitral.
The territory between Afghanistan and British India was demarcated between 1894 and 1896. Part of the frontier lying between Nawa Kotal in outskirts of Mohmand country and Bashgal Valley on outskirts of Kafiristan were demarcated by 1895 with an agreement reached on 9 April 1895. Abdur Rahman wanted to force every community and tribal confederation with his single interpretation of Islam due to it being the only uniting factor. After the subjugation of Hazaras, Kafiristan was the last remaining autonomous part. Field marshal Ghulam Hayder Khan sent a message to Kafirs of Barikut which stated, "It is not the duty of the government to compel, force or impose on them to accept, or take the path of the religion of Islam. The obligation that does exist is this: they render obedience and pay their taxes. As long as they do not disobey their command, they will not incinerate themselves with the fire of "padishah's" [king's] wrath. In addition, they are not to block the building of the road [that was planned through their territory]."
Emir Abdur Rahman Khan's forces invaded Kafiristan in the winter of 1895–1896 and captured it in 40 days according to his autobiography. Columns invaded it from the west through Panjshir to Kullum, the strongest fort of the region. The columns from the north came through Badakhshan and from the east through Asmar. A small column also came from south-west through Laghman. The Kafirs were forcibly converted to Islam and resettled in Laghman while the region was settled by veteran soldiers and other Afghans. Kafiristan was renamed as Nuristan. Other residents also converted to avoid the "jizya".
His victory was celebrated with the publishing of a poem in 1896 or 1897 and Faiz Mohammad Katib Hazara gave him the title "Idol-Smasher". About 60,000 of the Kafirs became converts. Mullahs were deployed after the conquest to teach them about fundamentals of Islam. The large-scale conversion proved difficult however and the complete Islamization took some time. Kafir elders are known to have offered sacrifices in their shrines on rumors of Rahman's death in 1901. Three main roads connecting Badakhshan with Kunar and Lamghan (Chigha Sirai-Munjan, Asmar-Badakhshan and Munjan-Laghman) were built after the conquest. | https://en.wikipedia.org/wiki?curid=3068 |
Durrani Empire
The Durrani Empire (), also called the Sadozai Kingdom () and Afghan Empire (), was founded and built by Ahmad Shah Durrani in parts of Central Asia, Middle east and South Asia. At its maximum extent, the empire ruled over what are now the modern-day countries of Afghanistan and Pakistan, as well as parts of northeastern and southeastern Iran, eastern Turkmenistan, and northwestern India.
After the death of Nader Shah Afshar in June 1747, the region of Kandahar was claimed by Ahmad Shah Durrani. From there, he conquered Ghazni, Kabul, and Peshawar in the same year. In 1749 the Mughal ruler had ceded sovereignty over much of northwest India to the Afghans. Ahmad Shah then set out westward to take possession of Mashhad, which was ruled by Shahrokh Shah. He next sent an army to subdue the areas north of the Hindu Kush and in short order all the different tribes began joining his cause. Ahmad Shah and his forces invaded India four times, taking control of Kashmir and the Punjab region. Early in 1757, he sacked Delhi, but permitted the Mughal dynasty to remain in nominal control as long as the ruler acknowledged Ahmad Shah's suzerainty over the Punjab, Sindh, and Kashmir.
After the death of Ahmad Shah in about 1772, his son Timur Shah became the next ruler of the Durrani dynasty who decided to make Kabul the new capital of the empire, and used Peshawar as the winter capital. The Durrani Empire is considered the foundation of the modern state of Afghanistan, with Ahmad Shah Durrani being credited as "Father of the Nation".
In 1709 Mir Wais Hotak, chief of the Ghilji tribe of Kandahar Province, gained independence from the Safavid Persians. From 1722 to 1725, his son Mahmud Hotak briefly ruled large parts of Iran and declared himself as "Shah of Persia". However, the Hotak dynasty came to a complete end in 1738 after being toppled and banished by the Afsharids who were led by Nader Shah Afshar of Persia.
The year 1747 marks the definitive appearance of an Afghan political entity independent of both the Persian and Mughal empires. In July 1747 a "loya jirga" (grand council) concluded near the city of Kandahar with Ahmad Shah Durrani being selected as the new leader of the Afghans, thus the Durrani dynasty was founded. Despite being younger than the other contenders, Ahmad Shah had several overriding factors in his favor. He belonged to a respectable family of political background, especially since his father served as Governor of Herat who died in a battle defending the Afghans.
One of Ahmad Shah's first military actions was to capture Qalati Ghilji and Ghazni from the Ghilji, and wrest Kabul and Peshawar from Mughal-appointed governor Nasir Khan. In 1749, the Mughal Emperor Ahmad Shah Bahadur was induced to cede Sindh, the Punjab region and the important trans Indus River to Ahmad Shah Durrani in order to save his capital from Afghan attack. Having thus gained substantial territories to the east without a fight, Ahmad Shah turned westward to take possession of Mashhad, which was ruled by Nader Shah Afshar's grandson, Shahrukh Afshar. Ahmad Shah next sent an army to subdue the areas north of the Hindu Kush mountains. In short order, the powerful army brought under its control the Tajik, Hazara, Uzbek, Turkmen, and other tribes of northern Afghanistan. Ahmad Shah invaded the remnants of the Mughal Empire a third time, and then a fourth, consolidating control over the Kashmir and Punjab regions, with Lahore being governed by Afghans. He sacked Delhi in 1757 but permitted the Mughal dynasty to remain in nominal control of the city as long as the ruler acknowledged Ahmad Shah's suzerainty over Punjab, Sindh, and Kashmir. Leaving his second son Timur Shah to safeguard his interests, Ahmad Shah left India to return to Afghanistan.
Alarmed by the expansion of China's Qing Dynasty up to the eastern border of Kazakhstan, Ahmad Shah attempted to rally neighboring Muslim khanates and the Kazakhs to unite and attack China, ostensibly to liberate its western Muslim subjects. Ahmad Shah halted trade with Qing China and dispatched troops to Kokand. However, with his campaigns in India exhausting the state treasury, and with his troops stretched thin throughout Central Asia, Ahmad Shah lacked sufficient resources to do anything except to send envoys to Beijing for unsuccessful talks.
The Mughal power in northern India had been declining after the death of Emperor Aurangzeb, who died in 1707. In 1751–52, "Ahamdiya" treaty was signed between the Marathas and Mughals, when Balaji Bajirao was the Peshwa. Through this treaty, the Marathas controlled virtually the whole of India from their capital at Pune and the Mughal rule was restricted only to Delhi (the Mughals remained the nominal heads of Delhi). Marathas were now straining to expand their area of control towards the Northwest of India. Ahmad Shah sacked the Mughal capital and withdrew with the booty he coveted. To counter the Afghans, Peshwa Balaji Bajirao sent Raghunathrao. He defeated the Rohillas and Afghan garrisons in Punjab and succeeded in ousting Timur Shah and his court from India and brought Lahore, Multan, Kashmir and other subahs on the Indian side of Attock under Maratha rule. Thus, upon his return to Kandahar in 1757, Ahmad was forced to return to India and face the formidable attacks of the Maratha Confederacy.
Ahmad Shah declared a jihad (or Islamic holy war) against the Marathas, and warriors from various Afghan tribes joined his army, including the Baloch people under the command of Khan of Kalat Mir Nasir I of Kalat. Suba Khan Tanoli (Zabardast Khan) was selected as army chief of all military forces. Early skirmishes were followed by victory for the Afghans against the much larger Maratha garrisons in Northwest India and by 1759 Ahmad Shah and his army had reached Lahore and were poised to confront the Marathas. Ahmad Shah Durrani was famous for winning wars much larger than his army. By 1760, the Maratha groups had coalesced into a big enough army under the command of Sadashivrao Bhau. Once again, Panipat was the scene of a confrontation between two warring contenders for control of northern India. The Third Battle of Panipat (14 January 1761), fought between largely Muslim and largely Hindu armies was waged along a twelve-kilometer front. Despite decisively defeating the Marathas, what might have been Ahmad Shah's peaceful control of his domains was disrupted by many challenges. As far as losses are concerned, Afghans too suffered heavily in the Third Battle of Panipat. This weakened his grasp over Punjab which fell to the rising Sikh misls. There were rebellions in the north in the region of Bukhara. The Durranis decisively defeated the Marathas in the Third Battle of Panipat on 14 January 1761. The defeat at Panipat resulted in heavy losses for the Marathas, and was a huge setback for Peshwa Balaji Rao. He received the news of the defeat of Panipat on 24 January 1761 at Bhilsa, while leading a reinforcement force. Besides several important generals, he had lost his own son Vishwasrao in the Battle of Panipat. He died on 23 June 1761, and was succeeded by his younger son Madhav Rao I.
The victory at Panipat was the high point of Ahmad Shah's—and Afghan—power. However, even prior to his death, the empire began to unravel. In 1762, Ahmad Shah crossed the passes from Afghanistan for the sixth time to subdue the Sikhs. From this time and on, the domination and control of the Empire began to loosen, and by the time of Durrani's death he had completely lost Punjab to the Sikhs, as well as earlier losses of northern territories to the Uzbeks, necessitating a compromise with them.
He assaulted Lahore and, after taking their holy city of Amritsar, massacred thousands of Sikh inhabitants, destroying their revered Golden Temple. Within two years, the Sikhs rebelled again and rebuilt their holy city of Amritsar. Ahmad Shah tried several more times to subjugate the Sikhs permanently, but failed. Durrani's forces instigated the Vaḍḍā Ghallūghārā when they killed thousands of Sikhs in the Punjab in 1762. Ahmad Shah also faced other
rebellions in the north, and eventually he and the Uzbek Emir of Bukhara agreed that the Amu Darya would mark the division of their lands.. Ahmad Shah retired to his home in the mountains east of Kandahar, where he died on April 14, 1773. He had succeeded to a remarkable degree in balancing tribal alliances and hostilities, and in directing tribal energies away from rebellion. He earned recognition as Ahmad Shah Baba, or "Father" of Afghanistan.
The Durrani Empire lost its control over Kashmir to the Sikh Empire in the Battle of Shopian in 1819.
Ahmad Shah's successors governed so ineptly during a period of profound unrest that within fifty years of his death, the Durrani empire "per se" was at an end, and Afghanistan was embroiled in civil war. Much of the territory conquered by Ahmad Shah fell to others in this half century. By 1818, the Sadozai rulers who succeeded Ahmad Shah controlled little more than Kabul and the surrounding territory within a 160-kilometer radius. They not only lost the outlying territories but also alienated other tribes and lineages among the Durrani Pashtuns.
Ahmad Shah was succeeded by his son, Timur Shah, who had been deputed to administer his father's conquests in Northern India, but had been driven out by the Marathas. Upon Ahmad Shah's death, the Durrani chieftains only reluctantly accepted Timur's accession. Most of his reign was spent fighting a civil war and resisting rebellion; Timur was even forced to move his capital from Kandahar to Kabul due to the insurgency. Timur Shah proved an ineffectual ruler, during whose reign the Durrani empire began to crumble. He is notable for having had 24 sons, several of whom became rulers of the Durrani territories. Timur died in 1793 and was then succeeded by his fifth son Zaman Shah
After the death of Timur Shah, three of his sons, the governors of Kandahar, Herat and Kabul, contended for the succession. Zaman Shah, governor of Kabul, held the field by virtue of being in control of the capital, and became shah at the age of twenty-three. Many of his half-brothers were imprisoned on their arrival in the capital for the purpose, ironically, of electing a new shah. The quarrels among Timur's descendants that threw Afghanistan into turmoil also provided the pretext for the interventions of outside forces.
The efforts of the Sadozai heirs of Timur to impose a true monarchy on the truculent Pashtun tribes, and their efforts to rule absolutely and without the advice of the other major Pashtun tribal leaders, were ultimately unsuccessful. The Sikhs started to rise under the command of Sikh chief, Ranjit Singh, who succeeded in wresting power from Zaman's forces. Later when Zaman was blinded by his brother, Ranjit Singh who gave him asylum in Punjab.
Zaman's downfall was triggered by his attempts to consolidate power. Although it had been through the support of the Barakzai chief, Painda Khan Barakzai, that he had come to the throne, Zaman soon began to remove prominent Barakzai leaders from positions of power and replace them with men of his own lineage, the Sadozai. This upset the delicate balance of Durrani tribal politics that Ahmad Shah had established and may have prompted Painda Khan and other Durrani chiefs to plot against the shah. Painda Khan and the chiefs of the Nurzai and the Alizai Durrani clans were executed, as was the chief of the Qizilbash clan. Painda Khan's son fled to Iran and pledged the substantial support of his Barakzai followers to a rival claimant to the throne, Zaman's younger brother, Mahmud Shah. The clans of the chiefs Zaman had executed joined forces with the rebels, and they took Kandahar without bloodshed.
Zeman Shah's overthrow in 1801 was not the end of civil strife in Afghanistan, but the beginning of even greater violence. Mahmud Shah's first reign lasted for only two years before he was replaced by Shuja Shah.
Yet another of Timur Shah's sons, Shuja Shah (or Shah Shuja), ruled for only six years. On June 7, 1809, Shuja Shah signed a treaty with the British, which included a clause stating that he would oppose the passage of foreign troops through his territories. This agreement, the first Afghan pact with a European power, stipulated joint action in case of Franco-Persian aggression against Afghan or British dominions. Only a few weeks after signing the agreement, Shuja was deposed by his predecessor, Mahmud. Much later, he was reinstated by the British, ruling during 1839–1842. Two of his sons also ruled for a brief period in 1842.
Mahmud's second reign lasted nine years. Mahmud alienated the Barakzai, especially Fateh Khan, the son of Painda Khan, who was eventually seized and blinded. Revenge would later be sought and obtained by Fateh Khan's youngest brother, Dost Mohammad Khan.
Ali Shah was another son of Timur Shah. He seized power for a brief period in 1818–1819.
Ayub Shah was another son of Timur Shah, who deposed Sultan Ali Shah. The Durrani Empire lost its control over Kashmir to the Sikh Empire in the Battle of Shopian in 1819. Ayub Shah was himself later deposed, and presumably killed in 1823. | https://en.wikipedia.org/wiki?curid=3070 |
Aimaq people
The Aimaq (), also transliterated as Aimak and Aymaq, are a collection of Sunni and mostly Dari Persian-speaking nomadic and semi-nomadic tribes. They live mostly found in the central and western highlands of Afghanistan, especially in Ghor, Badghis, and Herat Provinces, and to a lesser extent in the Khorasan Province of Iran. Aimaqs were originally known as "chahar" ("four") Aymaqs: the "Taymani" (the main element in the population of Ghor), the "Firozkohi" (mostly in Badghis), the "Jamshidi" and the "Timuri". Other sources state that the Aimaq Hazara are one of the "Chahar", with the Timuri instead being of the "lesser Aimaqs" or "Aimaq-e digar" ("other Aimaqs").
The Aimaq speak a number of subdialects of the Aimaq dialect of Dari Persian, but some southern groups of Taymani, Firozkohi, and northeastern Timuri Aimaqs have adopted the Pashto language.
The Aimaqs claim to be descended from the troops of Genghis Khan.
Aimaqs is a Turkic-Mongolic word that means "tribe" or "grazing territory". Aimaq Hazara and Timuri are the most Mongoloid of the Aimaqs as they live in yurts, whereas other Aimaqs live in traditional Afghan black tents. The Aimaq are largely nomadic to semi-nomadic goat and sheep herders. They also trade with villages and farmers during migrations for pastures for their livestock. The material culture and foodstuffs of the Aimaq include skins, carpets, milk, dairy products and more. They tend to trade these products to settled peoples in return for vegetables, grains, fruits, nuts, and other types of foods and goods.
Aimaq tribes
Estimates of the Aimaq population vary between 250,000 and 500,000. They are largely Sunni Muslims--except for the Jamshidi who are mainly Ismaili Shia in the main--and in contrast to the Hazara, who are mostly Shia Muslims. | https://en.wikipedia.org/wiki?curid=3071 |
Arcturus
Arcturus, designation α Boötis (Latinized to Alpha Boötis, abbreviated Alpha Boo, α Boo), is the brightest star in the constellation of Boötes, the fourth-brightest in the night sky, and the brightest in the northern celestial hemisphere. Together with Spica and Denebola (or Regulus, depending on the source), Arcturus is part of the Spring Triangle asterism and, by extension, also of the Great Diamond along with the star Cor Caroli. When viewed from Earth, it appears to be positioned almost at the north galactic pole of the Milky Way.
Relatively close at 36.7 light-years from the Sun, Arcturus is a red giant of spectral type K0III—an aging star around 7.1 billion years old that has used up its core hydrogen and moved off the main sequence. It is times as massive as the Sun, but has expanded to times its size and is around 170 times as luminous.
"α Boötis" (Latinised to "Alpha Boötis") is the star's Bayer designation.
The traditional name "Arcturus" derives from Ancient Greek Ἀρκτοῦρος ("Arktouros") and means "Guardian of the Bear", ultimately from ἄρκτος ("arktos"), "bear" and οὖρος ("ouros"), "watcher, guardian". It has been known by this name since at least the time of Hesiod.
One astronomical tradition associates Arcturus with the mythology around Arcas, who was about to shoot and kill his own mother Callisto who had been transformed into a bear. Zeus averted their imminent tragic fate by transforming the boy into the constellation Boötes, called Arctophylax "bear guardian" by the Greeks, and his mother into Ursa Major (Greek: Arctos "the bear"). The account is given in Hyginus's "Astronomy".
Aratus in his "Phaenomena" said that the star Arcturus lay below the belt of Arctophylax, although according to Ptolemy in the "Almagest" it lay between his thighs.
An alternative lore associates the name with the legend around Icarius, who gave the gift of wine to other men, but was murdered by them, because they had had no experience with intoxication and mistook the wine for poison. It is stated this Icarius, became Arcturus, while his dog, Maira, became Canicula (Procyon), although "Arcturus" here may be used in the sense of the constellation rather than the star.
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Arcturus" for this star. It is now so entered in the IAU Catalog of Star Names.
With an apparent visual magnitude of −0.05, Arcturus is the brightest star in the northern celestial hemisphere and the fourth-brightest star in the night sky, after Sirius (−1.46 apparent magnitude), Canopus (−0.72) and α Centauri (combined magnitude of −0.27). However, α Centauri AB is a binary star, whose components are both fainter than Arcturus. This makes Arcturus the third-brightest individual star, just ahead of α Centauri A (officially named "Rigil Kentaurus"), whose apparent magnitude . The French mathematician and astronomer Jean-Baptiste Morin observed Arcturus in the daytime with a telescope in 1635, a first for any star other than the Sun and supernovae. Arcturus has been seen at or just before sunset with the naked eye.
Arcturus is visible from both of Earth's hemispheres as it is located 19° north of the celestial equator. The star culminates at midnight on 27 April, and at 9 p.m. on June 10 being visible during the late northern spring or the southern autumn. From the northern hemisphere, an easy way to find Arcturus is to follow the arc of the handle of the Big Dipper (or Plough). By continuing in this path, one can find Spica, "Arc to Arcturus, then spike (or speed on) to Spica".
Ptolemy described Arcturus as "subrufa" ("slightly red"): it has a B-V color index of +1.23, roughly midway between Pollux (B-V +1.00) and Aldebaran (B-V +1.54).
η Boötis, or Muphrid, is only 3.3 light-years distant from Arcturus, and would have a visual magnitude −2.5, about as bright as Mercury from Earth, whereas an observer on the former system would find Arcturus as bright as Venus as seen from Earth.
In 1984, the 90 cm (36-inch) reflecting Yapp telescope at Herstmonceux was tested with an echelle spectrograph from Queen's University Belfast and a CCD camera. Observations of the stars Arcturus and Deneb (Alpha Cygni) were conducted in the summer of 1984.
Based upon an annual parallax shift of 88.83 milliarcseconds as measured by the Hipparcos satellite, Arcturus is from the Sun. The parallax margin of error is 0.54 milliarcseconds, translating to a distance margin of error of ±. Because of its proximity, Arcturus has a high proper motion, two arcseconds a year, greater than any first magnitude star other than α Centauri.
Arcturus is moving rapidly () relative to the Sun, and is now almost at its closest point to the Sun. Closest approach will happen in about 4,000 years, when the star will be a few hundredths of a light-year closer to Earth than it is today. (In antiquity, Arcturus was closer to the centre of the constellation.) Arcturus is thought to be an old-disk star, and appears to be moving with a group of 52 other such stars, known as the Arcturus stream.
With an absolute magnitude of −0.30, Arcturus is, together with Vega and Sirius, one of the most luminous stars in the Sun's neighborhood. It is about 110 times brighter than the Sun in visible light wavelengths, but this underestimates its strength as much of the light it gives off is in the infrared; total (bolometric) power output is about 180 times that of the Sun. With a near-infrared J band magnitude of −2.2, only Betelgeuse (−2.9) and R Doradus (−2.6) are brighter. The lower output in visible light is due to a lower efficacy as the star has a lower surface temperature than the Sun.
Arcturus is an evolved red giant star with a stellar classification of K0 III. As the brightest K-type giant in the sky, it was the subject of an atlas of its visible spectrum, made from photographic spectra taken with the coudé spectrograph of the Mt. Wilson 2.5m telescope published in 1968, a key reference work for stellar spectroscopy. Subsequent spectral atlases with greater wavelength coverage and superior signal-to-noise ratio made with digital detectors have supplanted the older work, but the Arcturus spectrum remains an important standard for stellar spectroscopy.
As a single star, the mass of Arcturus cannot be measured directly, but models suggest it is slightly larger than that of the Sun. Evolutionary matching to the observed physical parameters gives a mass of , while the oxygen isotope ratio for a first dredge-up star gives a mass of . The star displays magnetic activity that is heating the coronal structures, and it undergoes a solar-type magnetic cycle with a duration that is probably less than 14 years. A weak magnetic field has been detected in the photosphere with a strength of around half a gauss. The magnetic activity appears to lie along four latitudes and is rotationally-modulated.
Arcturus is estimated to be around 6 billion to 8.5 billion years old, but there is some uncertainty about its evolutionary status. Based upon the color characteristics of Arcturus, it is currently ascending the red-giant branch and will continue to do so until it accumulates a large enough degenerate helium core to ignite the helium flash. It has likely exhausted the hydrogen from its core and is now in its active hydrogen shell burning phase. However, Charbonnel et al. (1998) placed it slightly above the horizontal branch, and suggested it has already completed the helium flash stage.
As one of the brightest stars in the sky, Arcturus has been the subject of a number of studies in the emerging field of asteroseismology. Belmonte and colleagues carried out a radial velocity (Doppler shift of spectral lines) study of the star in April and May 1988, which showed variability with a frequency of the order of a few microhertz (μHz), the highest peak corresponding to 4.3 μHz (2.7 days) with an amplitude of 60 ms−1, with a frequency separation of c. 5 μHz. They suggested that the most plausible explanation for the variability of Arcturus is stellar oscillations.
Asteroseismological measurements allow direct calculation of the mass and radius, giving values of and . This form of modelling is still relatively inaccurate, but a useful check on other models.
Astronomers term "metals" those elements with higher atomic numbers than helium. Arcturus has an enrichment of alpha elements relative to iron but only about a third of solar metallicity. Arcturus is possibly a Population II star.
Hipparcos satellite astrometry also suggested that Arcturus is a binary star, with the companion about twenty times dimmer than the primary and orbiting close enough to be at the very limits of humans' current ability to make it out. Recent results remain inconclusive, but do support the marginal "Hipparcos" detection of a binary companion.
In 1993, radial velocity measurements of Aldebaran, Arcturus and Pollux showed that Arcturus exhibited a long-period radial velocity oscillation, which could be interpreted as a "substellar companion". This substellar object would be nearly 12 times the mass of Jupiter and be located roughly at the same orbital distance from Arcturus as the Earth is from the Sun, at 1.1 astronomical units. However, all three stars surveyed showed similar oscillations yielding similar companion masses, and the authors concluded that the variation was likely to be intrinsic to the star rather than due to the gravitational effect of a companion. So far no substellar companion has been confirmed.
In Arabic, Arcturus is one of two stars called "al-simāk" "the uplifted ones" (the other is Spica). Arcturus is specified as السماك الرامح "as-simāk ar-rāmiħ" "the uplifted one of the lancer". The term "Al Simak Al Ramih" has appeared in Al Achsasi Al Mouakket catalogue (translated into Latin as "Al Simak Lanceator").
This has been variously romanized in the past, leading to obsolete variants such as "Aramec" and "Azimech". For example, the name "Alramih" is used in Geoffrey Chaucer's "A Treatise on the Astrolabe" (1391). Another Arabic name is "Haris-el-sema", from "حارس السماء" "ħāris al-samā’" "the keeper of heaven". or "حارس الشمال" "ħāris al-shamāl’" "the keeper of north".
Arcturus was once again called by its classical name from the Renaissance onwards.
In Chinese astronomy, Arcturus is called "Da Jiao" (), because it is the brightest star in the Chinese constellation called "Jiao Xiu" (). Later it became a part of another constellation "Kang Xiu" ().
In Indian Astrology or Vedic Astrology or Sidereal Astrology, Arcturus is called "Swati" which is a word meaning "very beneficent" derived from the language Sanskrit. It is the eponymous star of one of the nakshatras (lunar mansions) of Hindu astrology.
The Wotjobaluk Koori people of southeastern Australia knew Arcturus as "Marpean-kurrk", mother of "Djuit" (Antares) and another star in Boötes, "Weet-kurrk" (Muphrid). Its appearance in the north signified the arrival of the larvae of the wood ant (a food item) in spring. The beginning of summer was marked by the star's setting with the Sun in the west and the disappearance of the larvae. The people of Milingimbi Island in Arnhem Land saw Arcturus and Muphrid as man and woman, and took the appearance of Arcturus at sunrise as a sign to go and harvest "rakia" or spikerush. The Wailwun of northern New South Wales knew Arcturus as "Guembila" "red".
In Inuit astronomy, Arcturus is called the Old Man ("Uttuqalualuk" in Inuit languages) and The First Ones ("Sivulliik" in Inuit languages).
The Mi'kmaq of eastern Canada saw Arcturus as "Kookoogwéss", the owl.
Arcturus had several names that described its significance to indigenous Polynesians. In the Society Islands, Arcturus, called "Ana-tahua-taata-metua-te-tupu-mavae" ("a pillar to stand by"), was one of the ten "pillars of the sky", bright stars that represented the ten heavens of the Tahitian afterlife. In Hawaii, the pattern of Boötes was called "Hoku-iwa", meaning "stars of the frigatebird". This constellation marked the path for Hawaiiloa on his return to Hawaii from the South Pacific Ocean. The Hawaiians called Arcturus "Hoku-leʻa". It was equated to the Tuamotuan constellation "Te Kiva", meaning "frigatebird", which could either represent the figure of Boötes or just Arcturus. However, Arcturus may instead be the Tuamotuan star called "Turu". The Hawaiian name for Arcturus as a single star was likely "Hoku-leʻa", which means "star of gladness", or "clear star". In the Marquesas Islands, Arcturus was probably called "Tau-tou" and was the star that ruled the month approximating January. The Māori and Moriori called it "Tautoru", a variant of the Marquesan name and a name shared with Orion's Belt.
As one of the brightest stars in the sky, Arcturus has been significant to observers since antiquity.
Prehistoric Polynesian navigators knew Arcturus as "Hōkūleʻa", the "Star of Joy". Arcturus is the zenith star of the Hawaiian Islands. Using Hōkūleʻa and other stars, the Polynesians launched their double-hulled canoes from Tahiti and the Marquesas Islands. Traveling east and north they eventually crossed the equator and reached the latitude at which Arcturus would appear directly overhead in the summer night sky. Knowing they had arrived at the exact latitude of the island chain, they sailed due west on the trade winds to landfall. If Hōkūleʻa could be kept directly overhead, they landed on the southeastern shores of the Big Island of Hawaiʻi. For a return trip to Tahiti the navigators could use Sirius, the zenith star of that island. Since 1976, the Polynesian Voyaging Society's "Hōkūleʻa" has crossed the Pacific Ocean many times under navigators who have incorporated this wayfinding technique in their non-instrument navigation.
In ancient Mesopotamia, it was linked to the god Enlil, and also known as Shudun, "yoke", or SHU-PA of unknown derivation in the "Three Stars Each" Babylonian star catalogues and later MUL.APIN around 1100 BC.
In Ancient Rome, the star's celestial activity was supposed to portend tempestuous weather, and a personification of the star acts as narrator of the prologue to Plautus' comedy "Rudens" (circa 211 BC).
In the Hebrew scriptures Arcturus is referred to in Job 38:32.
In the Middle Ages, Arcturus was considered a Behenian fixed star and attributed to the stone Jasper and the plantain herb. Cornelius Agrippa listed its kabbalistic sign under the alternate name "Alchameth".
The Karandavyuha sutra, compiled at the end of the 4th century or beginning of the 5th century, names one of Avalokiteshvara's meditative absorptions as "The face of Arcturus".
One of the possible etymologies offered for the name "Arthur" assumes that it is derived from "Arcturus" and that the early Medieval character on whom the myth of King Arthur is based was originally named for the star.
Arcturus achieved fame when its light was rumored to be the mechanism used to open the 1933 Chicago World's Fair. The star was chosen as it was thought that light from Arcturus had started its journey at about the time of the previous Chicago World's Fair in 1893 (at 36.7 light-years away, the light actually started in 1896).
The star is mentioned in the 1977 documentary film "Powers of Ten", in which it is seen when a camera zooms from Earth to the whole of the known universe. | https://en.wikipedia.org/wiki?curid=3072 |
Albert Brooks
Albert Brooks (born Albert Lawrence Einstein; July 22, 1947) is an American actor, comedian, writer, and director. He received an Academy Award nomination for Best Supporting Actor for 1987's "Broadcast News" and was widely praised for his performance as a ruthless Jewish mobster in the 2011 film "Drive". His voice acting credits include Marlin in "Finding Nemo" (2003) and "Finding Dory" (2016), Tiberius in "The Secret Life of Pets" (2016) and recurring guest voices for "The Simpsons", including Russ Cargill in "The Simpsons Movie" (2007) and Hank Scorpio. He has written, directed, and starred in several comedy films, such as "Modern Romance" (1981), "Lost in America" (1985), and "Defending Your Life" (1991). He is also the author of "2030: The Real Story of What Happens to America" (2011).
Brooks was born Albert Lawrence Einstein into a Jewish show business family in Beverly Hills, California, to Thelma Leeds (née Goodman), a singer and actress, and Harry Einstein, a radio comedian who performed on Eddie Cantor's radio program and was known as "Parkyakarkus". His brothers are the late comedic actor Bob Einstein, better known as a character he created named "Super Dave Osborne", and for a recurring role in "Curb Your Enthusiasm"; and Cliff Einstein, a partner and longtime chief creative officer at Los Angeles advertising agency Dailey & Associates. His half-brother was Charles Einstein, a writer for such television programs as "Playhouse 90" and "Lou Grant". His grandparents emigrated from Austria and Russia. He grew up among show business families in southern California, attending Beverly Hills High School with Richard Dreyfuss and Rob Reiner.
Brooks attended Carnegie Mellon University in Pittsburgh, but dropped out after one year to focus on his comedy career. By the age of 19, he had changed his professional name to Albert Brooks, joking that "the real Albert Einstein changed his name to sound more intelligent". He began a comedy career and quickly became a regular on variety and talk shows during the late 1960s and early 1970s. Brooks led a new generation of self-reflective baby-boomer comics appearing on NBC's "The Tonight Show Starring Johnny Carson". His onstage persona, that of an egotistical, narcissistic, nervous comic, an ironic showbiz insider who punctured himself before an audience by disassembling his mastery of comedic stagecraft, influenced other '70s post-modern comedians, including Steve Martin, Martin Mull, and Andy Kaufman.
After two successful comedy albums, "Comedy Minus One" (1973) and the Grammy Award–nominated "A Star Is Bought" (1975), Brooks left the stand-up circuit to try his hand as a filmmaker. He had already made his first short film, "The Famous Comedians School", a satiric short and an early example of the mockumentary subgenre that was aired in 1972 on the PBS show "The Great American Dream Machine".
In 1975, Brooks directed six short films for the first season of NBC's "Saturday Night Live":
In 1976, he appeared in his first mainstream film role, in Martin Scorsese's landmark "Taxi Driver"; Scorsese allowed Brooks to improvise much of his dialogue. Brooks had landed the role after moving to Los Angeles to enter the film business. In an interview, Brooks mentioned a conversation he had had with "Taxi Driver" screenwriter Paul Schrader, in which Schrader said that Brooks's character was the only one in the movie that he could not "understand" – a remark that Brooks found amusing, as the movie's antihero was a psychotic loner.
Brooks directed his first feature film, "Real Life", in 1979. The film, in which Brooks (playing a version of himself) films a typical suburban family in an effort to win both an Oscar and a Nobel Prize, was a sendup of PBS's "An American Family" documentary. It has also been viewed as foretelling the future emergence of reality television. Brooks also made a cameo appearance in the film "Private Benjamin" (1980), starring Goldie Hawn. (He got starring credits in the film, although his character dies within roughly the first half-hour of the film.)
Through the 1980s and 1990s, Brooks co-wrote (with longtime collaborator Monica Johnson), directed and starred in a series of well-received comedies, playing variants on his standard neurotic and self-obsessed character. These include 1981's "Modern Romance", where Brooks played a film editor desperate to win back his ex-girlfriend (Kathryn Harrold). The film received a limited release and ultimately grossed under $3 million domestically. It was well received by critics, with one reviewer commenting that the film was "not Brooks at his best, but still amusing". His best-received film, "Lost in America" (1985), featured Brooks and Julie Hagerty as a couple who leave their yuppie lifestyle and drop out of society to live in a motor home as they have always dreamed of doing, meeting disappointment.
Brooks's "Defending Your Life" (1991) placed his lead character in the afterlife, put on trial to justify his human fears and determine his cosmic fate. Critics responded to the offbeat premise and the chemistry between Brooks and Meryl Streep, as his post-death love interest. His later efforts did not find large audiences, but still retained Brooks's touch as a filmmaker. He garnered positive reviews for "Mother" (1996), which starred Brooks as a middle-aged writer moving back home to resolve tensions between himself and his mother (Debbie Reynolds). 1999's "The Muse" featured Brooks as a Hollywood screenwriter who has "lost his edge", using the services of an authentic muse (Sharon Stone) for inspiration. In an interview with Brooks with regards to "The Muse", Gavin Smith wrote, "Brooks's distinctive film making style is remarkably discreet and unemphatic; he has a light, deft touch, with a classical precision and economy, shooting and cutting his scenes in smooth, seamless successions of medium shots, with clean, high-key lighting."
Brooks has appeared as a guest voice on "The Simpsons" seven times during its run (always under the name "A. Brooks"). He is described as the best guest star in the show's history by IGN, particularly for his role as supervillain Hank Scorpio in the episode "You Only Move Twice".
Brooks also acted in other writers' and directors' films during the 1980s and 1990s. He had a cameo in the opening scene of "", playing a driver whose passenger (Dan Aykroyd) has a shocking secret. In James L. Brooks's hit "Broadcast News" (1987), Albert Brooks was nominated for an Academy Award for Best Supporting Actor for playing an insecure, supremely ethical network TV reporter, who offers the rhetorical question, "Wouldn't this be a great world if insecurity and desperation made us more attractive?" He also won positive notices for his role in 1998's "Out of Sight", playing an untrustworthy banker and ex-convict.
Brooks received positive reviews for his portrayal of a dying retail store owner who befriends disillusioned teen Leelee Sobieski in "My First Mister" (2001). Brooks continued his voiceover work in Pixar's "Finding Nemo" (2003), as the voice of Marlin, one of the film's protagonists.
In 2005, his film "Looking for Comedy in the Muslim World" was dropped by Sony Pictures due to their desire to change the title. Warner Independent Pictures purchased the film and gave it a limited release in January 2006; the film received mixed reviews and a low box office gross. As with "Real Life", Brooks plays a fictionalized "Albert Brooks", a filmmaker ostensibly commissioned by the U.S. government to see what makes the Muslim people laugh, and sending him on a tour of India and Pakistan.
In 2006 he appeared in the documentary film "Wanderlust" as David Howard from "Lost in America". The documentary included many other well-known people. In 2007, he continued his long-term collaboration with "The Simpsons" by voicing Russ Cargill, the central antagonist of "The Simpsons Movie".
He has played Lenny Botwin, Nancy Botwin's estranged father-in-law, on Showtime's television series "Weeds". St. Martin's Press published his first novel, "2030: The Real Story of What Happens to America", on May 10, 2011.
In 2011, Brooks co-starred as the vicious gangster Bernie Rose, the main antagonist in the film "Drive", alongside Ryan Gosling and Carey Mulligan. His performance received much critical praise and positive reviews, with several critics proclaiming Brooks' performance as one of the film's best aspects. After receiving awards and nominations from several film festivals and critic groups, but not an Academy Award nomination, Brooks responded humorously on Twitter, "And to the Academy: ‘You don't like me. You really don't like me’."
In 2016, Brooks voiced Tiberius, a curmudgeonly red-tailed hawk in "The Secret Life of Pets", and reprised the role of Marlin from "Finding Nemo" in the 2016 sequel "Finding Dory". "Dory" is Brooks's largest grossing film to date.
In 1997, Brooks married artist Kimberly Shlain, daughter of surgeon and writer Leonard Shlain. They have two children, Jacob and Claire. | https://en.wikipedia.org/wiki?curid=3075 |
Antares
Antares , designated α Scorpii (Latinised to Alpha Scorpii, abbreviated Alpha Sco, α Sco), is on average the fifteenth-brightest star in the night sky, and the brightest object in the constellation of Scorpius. Distinctly reddish when viewed with the naked eye, Antares is a slow irregular variable star that ranges in brightness from apparent magnitude +0.6 to +1.6. Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ Scorpii near the center of the constellation.
Classified as spectral type M1.5Iab-Ib, Antares is a red supergiant, a large evolved massive star and one of the largest stars visible to the naked eye. Its exact size remains uncertain, but if placed at the center of the Solar System, it would reach to somewhere between the orbits of Mars and Jupiter. Its mass is calculated to be around 12 times that of the Sun.
Antares is the brightest, most massive, and most evolved stellar member of the nearest OB association, the Scorpius–Centaurus Association. Antares is a member of the Upper Scorpius subgroup of the association, which contains thousands of stars with a mean age of 11 million years, about from Earth.
Antares appears as a single star when viewed with the naked eye, but it is actually a binary star, with its two components called α Scorpii A and α Scorpii B. The brighter of the pair is the red supergiant, while the fainter is a hot main sequence star of magnitude 5.5.
"α Scorpii" (Latinised to "Alpha Scorpii") is the star's Bayer designation. Antares has the Flamsteed designation 21 Scorpii, as well as catalogue designations such as HR 6134 in the Bright Star Catalogue and HD 148478 in the Henry Draper Catalogue. As a prominent infrared source, it appears in the Two Micron All-Sky Survey catalogue as 2MASS J16292443-2625549 and the Infrared Astronomical Satellite (IRAS) Sky Survey Atlas catalogue as IRAS 16262–2619. It is also catalogued as a double star WDS J16294-2626 and CCDM J16294-2626. Antares is a variable star and is listed in the General Catalogue of Variable Stars but as a Bayer-designated star it does not have a separate variable star designation.
Its traditional name "Antares" derives from the Ancient Greek , meaning "rival to-Ares" ("opponent to-Mars"), due to the similarity of its reddish hue to the appearance of the planet Mars. The comparison of Antares with Mars may have originated with early Mesopotamian astronomers. Some scholars have speculated that the star may have been named after Antar, or Antarah ibn Shaddad, the Arab warrior-hero celebrated in the pre-Islamic poems Mu'allaqat. In 2016, the International Astronomical Union organised a Working Group on Star Names (WGSN) to catalog and standardise proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN, which included "Antares" for the star α Scorpii A. It is now so entered in the IAU Catalog of Star Names.
Antares is visible all night around May 31 of each year, when the star is at opposition to the Sun. Antares then rises at dusk and sets at dawn as seen at the equator. For two to three weeks on either side of November 30 Antares is not visible in the night sky, because it is near conjunction with the Sun. In higher northern latitudes, Antares is only visible low in the south in summertime. Higher than 64° northern latitude, the star does not rise at all. On the other side in the whole of Antarctica, the star is circumpolar as the whole continent is above 64° S latitude.
Radial velocity variations were observed in the spectrum of Antares in the early 20th century and attempts were made to derive spectroscopic orbits. It became apparent that the small variations could not be due to orbital motion, and were actually caused by pulsation of the star's atmosphere. Even in 1928, it was calculated that the size of the star must vary by about 20%.
Antares was first reported to have a companion star by Johann Tobias Bürg during an occultation on April 13, 1819, although this was not widely accepted and dismissed as a possible atmospheric effect. It was then observed by Scottish astronomer James William Grant FRSE while in India on 23 July 1844. It was rediscovered by Ormsby M. Mitchel in 1846, and measured by William Rutter Dawes in April 1847.
In 1952, Antares was reported to vary in brightness. A photographic magnitude range from 3.00 to 3.16 was described. The brightness has been monitored by the American Association of Variable Star Observers since 1945, and it has been classified as an "LC" slow irregular variable star, whose apparent magnitude slowly varies between extremes of +0.6 and +1.6, although usually near magnitude +1.0. There is no obvious periodicity, but statistical analyses have suggested periods of 1,733 days or days. No separate long secondary period has been detected, although it has been suggested that primary periods longer than a thousand days are analogous to long secondary periods.
Research published in 2018 demonstrated that Ngarrindjeri Aboriginal people from South Australia observed the variability of Antares and incorporated it into their oral traditions as Waiyungari (meaning 'red man').
Antares is 4.57 degrees south of the ecliptic, one of four first magnitude stars within 6° of the ecliptic (the others are Spica, Regulus and Aldebaran), so it can be occulted by the Moon. On 31 July 2009, Antares was occulted by the Moon. The event was visible in much of southern Asia and the Middle East. Every year around December 2 the Sun passes 5° north of Antares. Lunar occultations of Antares are fairly common, depending on the 18.6-year cycle of the lunar nodes. The last cycle ended in 2010 and the next begins in 2023. Shown at right is a video of a reappearance event, clearly showing events for both components.
Antares can also be occulted by the planets, e.g. Venus, but these events are rare. The last occultation of Antares by Venus took place on September 17, 525 BC; the next one will be November 17, 2400. Other planets have been calculated not to have occulted Antares over the last millennium, nor will they in the next millennium, as most planets stay near the ecliptic and pass north of Antares. Venus will be extremely near Antares on October 19, 2117 and every eight years thereafter through to October 29, 2157 it will pass "south" of the star.
Antares illuminates in the foreground parts of the Rho Ophiuchi cloud complex. The illuminated cloud is sometimes called Antares Nebula or otherwise identified as VdB 107, Ced 132, DG 141, LBN 1107 and Magakian 668.
α Scorpii is a double star that are thought to form a binary system. The best calculated orbit for the stars is considered to be unreliable. It describes an almost circular orbit seen nearly edge-on, with a period of 1,218 years and a semi-major axis of about . Other recent estimates of the period have ranged from 880 years for a calculated orbit, to 2,562 years for a simple Kepler's Law estimate.
Early measurements of the pair found them to be about apart in 1847–49, or apart in 1848. More modern observations consistently give separations around . The variations in the separation are often interpreted as evidence of orbital motion, but are more likely to be simply observational inaccuracies with very little true relative motion between the two components.
The pair have a projected separation of about 529 astronomical units (AU) (≈ 80 billion km) at the estimated distance of Antares, giving a minimum value for the distance between them. Spectroscopic examination of the energy states in the outflow of matter from the companion star suggests that it is over beyond the primary (more than 110 billion km).
Antares is a red supergiant star with a stellar classification of M1.5Iab-Ib, and is indicated to be a spectral standard for that class. Due to the nature of the star, the derived parallax measurements have large errors, so that the true distance of Antares is approximately from the Sun.
The brightness of Antares at visual wavelengths is about 10,000 times that of the Sun, but because the star radiates a considerable part of its energy in the infrared part of the spectrum, the true bolometric luminosity is around 100,000 times that of the Sun. There is a large margin of error assigned to values for the bolometric luminosity, typically 30% or more. There is also considerable variation between values published by different authors, for example and published in 2012 and 2013.
The mass of the star has been calculated to be about , or . Comparison of the effective temperature and luminosity of Antares to theoretical evolutionary tracks for massive stars suggest a progenitor mass of and an age of 12 million years (MYr), or an initial mass of and an age of 11 to 15 MYr. Massive stars like Antares are expected to explode as supernovae.
Like most cool supergiants, Antares's size has much uncertainty due to the tenuous and translucent nature of the extended outer regions of the star. Defining an effective temperature is difficult due to spectral lines being generated at different depths in the atmosphere, and linear measurements produce different results depending on the wavelength observed. In addition, Antares appears to pulsate, varying its radius by 19%. It also varies in temperature by 150 K, lagging 70 days behind radial velocity changes which are likely to be caused by the pulsations.
The diameter of Antares can be measured most accurately using interferometry or observing lunar occultations events. An apparent diameter from occultations 41.3 ± 0.1 milliarcseconds has been published. Interferometry allows synthesis of a view of the stellar disc, which is then represented as a limb-darkened disk surrounded by an extended atmosphere. The diameter of the limb-darkened disk was measured as in 2009 and in 2010. The linear radius of the star can be calculated from its angular diameter and distance. However, the distance to Antares is not known with the same accuracy as modern measurements of its diameter.
The Hipparcos satellite's trigonometric parallax of leads to a radius of about . Older radii estimates exceeding were derived from older measurements of the diameter, but those measurements are likely to have been affected by asymmetry of the atmosphere and the narrow range of infrared wavelengths observed; Antares has an extended shell which radiates strongly at those particular wavelengths. Despite its large size compared to the Sun, Antares is dwarfed by even larger red supergiants, such as VY Canis Majoris or VV Cephei A and Mu Cephei.
Antares, like the similarly-sized red supergiant Betelgeuse in the constellation Orion, will almost certainly explode as a supernova, possibly in the next ten thousand years. For a few months, the Antares supernova could be as bright as the full moon and be visible in daytime.
Antares B is a magnitude 5.5 blue-white main-sequence star of spectral type B2.5V; it also has numerous unusual spectral lines suggesting it has been polluted by matter ejected by Antares. It is assumed to be a relatively normal early-B main sequence star with a mass around , a temperature around , and a radius of about .
Antares B is normally difficult to see in small telescopes due to glare from Antares, but can sometimes be seen in apertures over . It is often described as green, but this is probably either a contrast effect, or the result of the mixing of light from the two stars when they are seen together through a telescope and are too close to be completely resolved. Antares B can sometimes be observed with a small telescope for a few seconds during lunar occultations while Antares is hidden by the Moon. Antares B appears a profound blue or bluish-green color, in contrast to the orange-red Antares.
In the Babylonian star catalogues dating from at least 1100 BCE, Antares was called GABA GIR.TAB, "the Breast of the Scorpion". In MUL.APIN, which dates between 1100 and 700 BC, it is one of the stars of Ea in the southern sky and marks breast of the Scorpion goddess Ishhara. Later names that translate as "the Heart of Scorpion" include ' from the Arabic '. This had been directly translated from the Ancient Greek '. ' translated above Greek name into Latin.
In ancient Mesopotamia, Antares may have been known by the following names: Urbat, Bilu-sha-ziri ("the Lord of the Seed"), Kak-shisa ("the Creator of Prosperity"), Dar Lugal ("The King"), Masu Sar ("the Hero and the King"), and Kakkab Bir ("the Vermilion Star"). In ancient Egypt, Antares represented the scorpion goddess Serket (and was the symbol of Isis in the pyramidal ceremonies). It was called "tms n hntt" "the red one of the prow".
In Persia Antares was known as "Satevis", one of the four "royal stars". In India, it with σ Scorpii and τ Scorpii were Jyeshthā (the eldest or biggest, probably attributing its huge size), one of the "nakshatra" (Hindu lunar mansions).
The ancient Chinese called Antares 心宿二 ("Xīnxiù'èr", "second star of mansion Heart"), because it was the second star of the mansion "Xin" (心). It was the national star of the Shang Dynasty, and it was sometimes referred to as () because of its reddish appearance.
The Māori people of New Zealand call Antares "Rēhua", and regard it as the chief of all the stars. Rēhua is father of "Puanga/Puaka" (Rigel), an important star in the calculation of the Māori calendar. The Wotjobaluk Koori people of Victoria, Australia, knew Antares as "Djuit", son of "Marpean-kurrk" (Arcturus); the stars on each side represented his wives. The Kulin Kooris saw Antares ("Balayang") as the brother of "Bunjil" (Altair).
Antares appears in the flag of Brazil, which displays 27 stars, each representing a federated unit of Brazil. Antares represents the state of Piauí. | https://en.wikipedia.org/wiki?curid=3076 |
Aldebaran
Aldebaran , designated α Tauri (Latinized to Alpha Tauri, abbreviated Alpha Tau, α Tau), is an orange giant star about 65 light-years from the Sun in the zodiac constellation Taurus. It is the brightest star in Taurus and generally the fourteenth-brightest star in the night sky, though it varies slowly in brightness between magnitude 0.75 and 0.95. Aldebaran hosts a planet several times the mass of Jupiter, named .
Aldebaran is a red giant, cooler than the sun with a surface temperature of , but its radius is about 44 times the sun's, so it is over 400 times as luminous. It spins slowly and takes 520 days to complete a rotation.
The planetary exploration probe Pioneer 10 is heading in the general direction of the star and should make its closest approach in about two million years.
The traditional name Aldebaran derives from the Arabic "al Dabarān", meaning "the follower", because it seems to follow the Pleiades. In 2016, the International Astronomical Union Working Group on Star Names (WGSN) approved the proper name "Aldebaran" for this star.
Aldebaran is the brightest star in the constellation Taurus and so has the Bayer designation α Tauri, Latinised as Alpha Tauri. It has the Flamsteed designation 87 Tauri as the 87th star in the constellation of approximately 7th magnitude or brighter, ordered by right ascension. It also has the Bright Star Catalogue number 1457, the HD number 29139, and the Hipparcos catalogue number 21421, mostly seen in scientific publications.
It is a variable star listed in the General Catalogue of Variable Stars, but it is listed using its Bayer designation and does not have a separate variable star designation.
Aldebaran and several nearby stars are included in double star catalogues such as the Washington Double Star Catalog as WDS 04359+1631 and the Aitken Double Star Catalogue as ADS 3321. It was included with an 11th magnitude companion as a double star as H IV 66 in the Herschel Catalogue of Double Stars and Σ II 2 in the Struve Double Star Catalog, and together with a 14th magnitude star as β 550 in the Burnham Double Star Catalogue.
Aldebaran is one of the easiest stars to find in the night sky, partly due to its brightness and partly due to being near one of the more noticeable asterisms in the sky. Following the three stars of Orion's belt in the opposite direction to Sirius, the first bright star encountered is Aldebaran.
The star is, by chance, in the line of sight between the Earth and the Hyades, so it has the appearance of being the brightest member of the open cluster, but the cluster that forms the bull's-head-shaped asterism is more than twice as far away, at about 150 light years.
Aldebaran is 5.47 degrees south of the ecliptic and so can be occulted by the Moon. Such occultations occur when the Moon's ascending node is near the autumnal equinox. A series of 49 occultations occurred starting on 29 January 2015 and ending at 3 September 2018. Each event was visible from points in the northern hemisphere or close to the equator; people in e.g. Australia or South Africa can never observe an Aldebaran occultation since it is too far south of the ecliptic. A reasonably accurate estimate for the diameter of Aldebaran was obtained during the occultation of 22 September 1978. Aldebaran is in conjunction with the Sun around June 1 of each year.
With a near-infrared J band magnitude of −2.1, only Betelgeuse (−2.9), R Doradus (−2.6), and Arcturus (−2.2) are brighter at that wavelength.
On 11 March AD 509, a lunar occultation of Aldebaran was observed in Athens, Greece. English astronomer Edmund Halley studied the timing of this event, and in 1718 concluded that Aldebaran must have changed position since that time, moving several minutes of arc further to the north. This, as well as observations of the changing positions of stars Sirius and Arcturus, led to the discovery of proper motion. Based on present day observations, the position of Aldebaran has shifted 7′ in the last 2000 years; roughly a quarter the diameter of the full moon. Due to precession of the equinoxes, 5,000 years ago the equinox (Northern Hemisphere)|vernal equinox was close to Aldebaran.
English astronomer William Herschel discovered a faint companion to Aldebaran in 1782; an 11th magnitude star at an angular separation of 117″. This star was shown to be itself a close double star by S. W. Burnham in 1888, and he discovered an additional 14th magnitude companion at an angular separation of 31″. Follow on measurements of proper motion showed that Herschel's companion was diverging from Aldebaran, and hence they were not physically connected. However, the companion discovered by Burnham had almost exactly the same proper motion as Aldebaran, suggesting that the two formed a wide binary star system.
Working at his private observatory in Tulse Hill, England, in 1864 William Huggins performed the first studies of the spectrum of Aldebaran, where he was able to identify the lines of nine elements, including iron, sodium, calcium, and magnesium. In 1886, Edward C. Pickering at the Harvard College Observatory used a photographic plate to capture fifty absorption lines in the spectrum of Aldebaran. This became part of the Draper Catalogue, published in 1890. By 1887, the photographic technique had improved to the point that it was possible to measure a star's radial velocity from the amount of Doppler shift in the spectrum. By this means, the recession velocity of Aldebaran was estimated as (48 km/s), using measurements performed at Potsdam Observatory by Hermann C. Vogel and his assistant Julius Scheiner.
Aldebaran was observed using an interferometer attached to the Hooker Telescope at the Mount Wilson Observatory in 1921 in order to measure its angular diameter, but it was not resolved in these observations.
The extensive history of observations of Aldebaran led to it being included in the list of 33 stars chosen as benchmarks for the Gaia mission to calibrate derived stellar parameters. It had previously been used to calibrate instruments on board the Hubble Space Telescope.
Aldebaran is listed as the spectral standard for type K5+ III stars. Its spectrum shows that it is a giant star that has evolved off the main sequence band of the Hertzsprung–Russell diagram after exhausting the hydrogen at its core. The collapse of the centre of the star into a degenerate helium core has ignited a shell of hydrogen outside the core and Aldebaran is now on the red giant branch (RGB).
The effective temperature of Aldebaran's photosphere is . It has a surface gravity of , typical for a giant star, but around 25 times lower than the Earth's and 700 times lower than the sun's. Its metallicity is about 30% lower than the sun's.
Measurements by the Hipparcos satellite and other sources put Aldebaran around away. Asteroseismology has determined that it is about 16% more massive than the Sun, yet it shines with 518 times the Sun's luminosity due to the expanded radius. The angular diameter of Aldebaran has been measured many times. The value adopted as part of the Gaia benchmark calibration is . It is 44 times the diameter of the Sun, approximately 61 million kilometres.
Aldebaran is a slightly variable star, assigned to the slow irregular type "LB". The General Catalogue of Variable Stars indicates variation between apparent magnitude 0.75 and 0.95 from historical reports. Modern studies show a smaller amplitude, with some showing almost no variation. Hipparcos photometry shows an amplitude of only about 0.02 magnitudes and a possible period around 18 days. Intensive ground-based photometry showed variations of up to 0.03 magnitudes and a possible period around 91 days. Analysis of observations over a much longer period still find a total amplitude likely to be less than 0.1 magnitudes, and the variation is considered to be irregular.
The photosphere shows abundances of carbon, oxygen, and nitrogen that suggest the giant has gone through its first dredge-up stage—a normal step in the evolution of a star into a red giant during which material from deep within the star is brought up to the surface by convection. With its slow rotation, Aldebaran lacks a dynamo needed to generate a corona and hence is not a source of hard X-ray emission. However, small scale magnetic fields may still be present in the lower atmosphere, resulting from convection turbulence near the surface. The measured strength of the magnetic field on Aldebaran is 0.22 Gauss. Any resulting soft X-ray emissions from this region may be attenuated by the chromosphere, although ultraviolet emission has been detected in the spectrum. The star is currently losing mass at a rate of (about one Earth mass in 300,000 years) with a velocity of . This stellar wind may be generated by the weak magnetic fields in the lower atmosphere.
Beyond the chromosphere of Aldebaran is an extended molecular outer atmosphere (MOLsphere) where the temperature is cool enough for molecules of gas to form. This region lies at about 2.5 times the radius of the star and has a temperature of about . The spectrum reveals lines of carbon monoxide, water, and titanium oxide. Outside the MOLSphere, the stellar wind continues to expand until it reaches the termination shock boundary with the hot, ionized interstellar medium that dominates the Local Bubble, forming a roughly spherical astrosphere with a radius of around 1,000 AU, centered on Aldebaran.
Five faint stars appear close to Aldebaran in the sky. These double star components were given upper-case Latin letter designations more or less in the order of their discovery, with the letter A reserved for the primary star. Some characteristics of these components, including their position relative to Aldebaran, are shown in the table.
Some surveys, for example Gaia Data Release 2, have indicated that Alpha Tauri B may have about the same proper motion and parallax as Aldebaran and thus may be a physical binary system. These measurements are difficult, since the dim B component appears so close to the bright primary star, and the margin of error is too large to establish (or exclude) a physical relationship between the two. So far neither the B component, nor anything else, has been unambiguously shown to be physically associated with Aldebaran. A spectral type of M2.5 has been published for Alpha Tauri B.
Alpha Tauri CD is a binary system with the C and D component stars gravitationally bound to and co-orbiting each other. These co-orbiting stars have been shown to be located far beyond Aldebaran and are members of the Hyades star cluster. As with the rest of the stars in the cluster they do not physically interact with Aldebaran in any way.
In 1993 radial velocity measurements of Aldebaran, Arcturus and Pollux showed that Aldebaran exhibited a long-period radial velocity oscillation, which could be interpreted as a substellar companion. The measurements for Aldebaran implied a companion with a minimum mass 11.4 times that of Jupiter in a 643-day orbit at a separation of in a mildly eccentric orbit. However, all three stars surveyed showed similar oscillations yielding similar companion masses, and the authors concluded that the variation was likely to be intrinsic to the star rather than due to the gravitational effect of a companion.
In 2015 a study showed stable long-term evidence for both a planetary companion and stellar activity. An asteroseismic analysis of the residuals to the planet fit has determined that Aldebaran b has a minimum mass of Jupiter masses, and that when the star was on the main sequence it would have given this planet Earth-like levels of illumination and therefore, potentially, temperature. This would place it and any of its moons in the habitable zone.
Aldebaran was originally نير الضبران ("Nā᾽ir al Dabarān" in Arabic), meaning "the bright one of the follower". "al Dabarān" (الدبران) then applied to the whole of the lunar mansion containing the Hyades. It is assumed that what it was following is the Pleiades. A variety of transliterated spellings have been used, with the current "Aldebaran" becoming standard relatively recently.
This easily seen and striking star in its suggestive asterism is a popular subject for ancient and modern myths.
The name Aldebaran or Alpha Tauri has been adopted many times, including
The star also appears in works of fiction such as "Far From the Madding Crowd" and "Down and Out in Paris and London". It is frequently seen in science fiction, including the "Lensman series" and "Fallen Dragon". As the brightest star in a Zodiac constellation, it is also given great significance within astrology.
Aldebaran regularly features in conspiracy theories as one of the origins of extraterrestrial aliens, often linked to Nazi UFOs. A well-known example is the German conspiracy theorist Axel Stoll, who considered the star the home of the Aryan race and the target of expeditions by the Wehrmacht.
The planetary exploration probe Pioneer 10 is no longer powered or in contact with Earth, but its trajectory is taking it in the general direction of Aldebaran. It is expected to make its closest approach in about two million years. | https://en.wikipedia.org/wiki?curid=3077 |
Altair
Altair , designation α Aquilae (Latinised to Alpha Aquilae, abbreviated Alpha Aql, α Aql), is the brightest star in the constellation of Aquila and the twelfth brightest star in the night sky. It is currently in the G-cloud—a nearby interstellar cloud, an accumulation of gas and dust. Altair is an A-type main sequence star with an apparent visual magnitude of 0.77 and is one of the vertices of the Summer Triangle asterism (the other two vertices are marked by Deneb and Vega). It is 16.7 light-years (5.13 parsecs) from the Sun and is one of the closest stars visible to the naked eye.
Altair rotates rapidly, with a velocity at the equator of approximately 286 km/s. This is a significant fraction of the star's estimated breakup speed of 400 km/s. A study with the Palomar Testbed Interferometer revealed that Altair is not spherical, but is flattened at the poles due to its high rate of rotation. Other interferometric studies with multiple telescopes, operating in the infrared, have imaged and confirmed this phenomenon.
"α Aquilae" (Latinised to "Alpha Aquilae") is the star's Bayer designation. The traditional name "Altair" has been used since medieval times. It is an abbreviation of the Arabic phrase "(An-nisr) Al-ta'ir" "".
In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN, which included "Altair" for this star. It is now so entered in the IAU Catalog of Star Names.
Along with β Aquilae and γ Aquilae, Altair forms the well-known line of stars sometimes referred to as the "Family of Aquila" or "Shaft of Aquila".
Altair is a type-A main sequence star with about 1.8 times the mass of the Sun and 11 times its luminosity. Altair rotates rapidly, with a rotational period of about 9 hours; for comparison, the equator of the Sun makes a complete rotation in a little more than 25 days. Its rapid rotation forces Altair to be oblate; its equatorial diameter is over 20 percent greater than its polar diameter.
Satellite measurements made in 1999 with the Wide Field Infrared Explorer showed that the brightness of Altair fluctuates slightly, varying by just a few thousandths of a magnitude with several different periods less than 2 hours. As a result, it was identified in 2005 as a Delta Scuti variable star. Its light curve can be approximated by adding together a number of sine waves, with periods that range between 0.8 and 1.5 hours. It is a weak source of coronal X-ray emission, with the most active sources of emission being located near the star's equator. This activity may be due to convection cells forming at the cooler equator.
The angular diameter of Altair was measured interferometrically by R. Hanbury Brown and his co-workers at Narrabri Observatory in the 1960s. They found a diameter of 3milliarcseconds. Although Hanbury Brown et al. realized that Altair would be rotationally flattened, they had insufficient data to experimentally observe its oblateness. Altair was later observed to be flattened by infrared interferometric measurements made by the Palomar Testbed Interferometer in 1999 and 2000. This work was published by G. T. van Belle, David R. Ciardi and their co-authors in 2001.
Theory predicts that, owing to Altair's rapid rotation, its surface gravity and effective temperature should be lower at the equator, making the equator less luminous than the poles. This phenomenon, known as gravity darkening or the von Zeipel effect, was confirmed for Altair by measurements made by the Navy Prototype Optical Interferometer in 2001, and analyzed by Ohishi et al. (2004) and Peterson et al. (2006). Also, A. Domiciano de Souza et al. (2005) verified gravity darkening using the measurements made by the Palomar and Navy interferometers, together with new measurements made by the VINCI instrument at the VLTI.
Altair is one of the few stars for which a direct image has been obtained. In 2006 and 2007, J. D. Monnier and his coworkers produced an image of Altair's surface from 2006 infrared observations made with the MIRC instrument on the CHARA array interferometer; this was the first time the surface of any main-sequence star, apart from the Sun, had been imaged. The false-color image was published in 2007. The equatorial radius of the star was estimated to be 2.03 solar radii, and the polar radius 1.63 solar radii—a 25% increase of the stellar radius from pole to equator. The polar axis is inclined by about 60° to the line of sight from the Earth.
The term "Al Nesr Al Tair" appeared in Al Achsasi al Mouakket's catalogue, which was translated into Latin as "Vultur Volans". This name was applied by the Arabs to the asterism of Altair, β Aquilae, and γ Aquilae and probably goes back to the ancient Babylonians and Sumerians, who called Altair "the eagle star". The spelling "Atair" has also been used. Medieval astrolabes of England and Western Europe depicted Altair and Vega as birds.
The Koori people of Victoria also knew Altair as "Bunjil", the wedge-tailed eagle, and β and γ Aquilae are his two wives the black swans. The people of the Murray River knew the star as "Totyerguil". The Murray River was formed when "Totyerguil" the hunter speared "Otjout", a giant Murray cod, who, when wounded, churned a channel across southern Australia before entering the sky as the constellation Delphinus.
In Chinese, the asterism consisting of Altair, β Aquilae, and γ Aquilae is known as "Hé Gǔ" (; lit. "river drum"). The Chinese name for Altair is thus "Hé Gǔ èr" (; lit. "river drum two", meaning the "second star of the drum at the river"). However, Altair is better known by its other names: "Qiān Niú Xīng" () or "Niú Láng Xīng" (), translated as the "cowherd star". These names are an allusion to a love story, "The Cowherd and the Weaver Girl", in which Niulang (represented by Altair) and his two children (represented by β Aquilae and γ Aquilae) are separated from respectively their wife and mother Zhinu (represented by Vega) by the Milky Way. They are only permitted to meet once a year, when magpies form a bridge to allow them to cross the Milky Way.
The people of Micronesia called Altair "Mai-lapa", meaning "big/old breadfruit", while the Māori people called this star "Poutu-te-rangi", meaning "pillar of heaven".
In Western astrology, the star Altair was ill-omened, portending danger from reptiles.
This star is one of the asterisms used by Bugis sailors for navigation, called "bintoéng timoro", meaning "eastern star"
Japan Airlines's Starjet 777-200 JA8983 was named Altair.
Altair Airlines was a regional airline that operated out of Philadelphia from 1966 to 1982.
NASA announced "Altair" as the name of the Lunar Surface Access Module (LSAM) on December 13, 2007. The Russian-made Beriev Be-200 Altair seaplane is also named after the star.
The Altair 8800 was one of the first microcomputers intended for home use.
Altair is the name of three United States navy ships: , and USNS Altair (T-AKR-291).
The Chevron 136,000-DWT Suezmax oil tanker originally named "Condoleezza Rice" (1993) was renamed "Altair Voyager (2001)".
One of the tankers attacked and damaged in the June 2019 Gulf of Oman incident was named "Front Altair".
"Altair" is the name of a 1919 poem by Karle Wilson Baker.
The bright primary star has the multiple star designation WDS 19508+0852A and has three faint visual companion stars, WDS 19508+0852B, C, and D. Component B is not physically close to A but merely appears close to it in the sky. | https://en.wikipedia.org/wiki?curid=3078 |
Australian Broadcasting Corporation
The Australian Broadcasting Corporation (ABC) is Australia's national broadcaster, founded in 1929. It is principally funded by the direct grants from the Australian government but is expressly independent of government and partisan politics. The ABC plays a leading role in journalistic independence and is fundamental in the history of broadcasting in Australia.
Modelled on the BBC in the United Kingdom, which is owned and controlled by the UK government, the ABC was originally financed by consumer licence fees on broadcast receivers. Licence fees were abolished in 1973 and replaced principally by direct government grants, as well as revenue from commercial activities related to its core broadcasting mission.
The ABC now provides radio, television, online and mobile services throughout metropolitan and regional Australia and overseas through ABC Australia and Radio Australia. The ABC's headquarters is in Ultimo, an inner-city suburb of Sydney, New South Wales.
Founded in 1929 as the Australian Broadcasting Company, the ABC was a government-licensed consortium of private entertainment and content providers, authorised under supervision to broadcast on the airwaves using a two-tiered system. The "A" system derived its funds primarily from the licence fees levied on the purchasers of the radio receivers, with an emphasis on building the radio wave infrastructure into regional and remote areas, whilst the "B" system relied on privateers and their capacity to establish viable enterprises using the new technology. Following the general downward economic trends of the era, as entrepreneurial ventures in National infrastructure struggled with viability, the "Company" was subsequently acquired to become a fully state-owned corporation on 1 July 1932 and renamed as Australian Broadcasting Commission, realigning more closely to the British, BBC model.
The "Australian Broadcasting Corporation Act 1983" changed the name of the organisation to the Australian Broadcasting Corporation, effective 1 July 1983. Although funded and owned by the government, the ABC remains editorially independent as ensured through the "Australian Broadcasting Corporation Act 1983".
The ABC is sometimes informally referred to as "Aunty", originally in imitation of the British Broadcasting Corporation's nickname.
The first public radio station in Australia opened in Sydney on 23 November 1923 under the call sign 2SB with other stations in Melbourne, Brisbane, Adelaide, Perth and Hobart following. A licensing scheme, administered by the Postmaster-General's Department, was soon established allowing certain stations government funding, albeit with restrictions placed on their advertising content.
Following a 1927 royal commission inquiry into radio licensing issues, the government established the National Broadcasting Service which subsequently took over a number of the larger funded stations. It also nationalised the Australian Broadcasting Company which had been created by entertainment interests to supply programs to various radio stations. On 1 July 1932, the Australian Broadcasting Commission was established, taking over the operations of the National Broadcasting Service and eventually establishing offices in each of Australia's capital cities.
Over the next four years the stations were reformed into a cohesive broadcasting organisation through regular program relays, coordinated by a centralised bureaucracy. The Australian broadcast radio spectrum was constituted of the ABC and the commercial sector.
News broadcasts were initially restricted, due to pressure from Sir Keith Murdoch, who controlled many Australian newspapers. However, journalists such as Frank Dixon and John Hinde began to subvert the agreements in the late 1930s. in 1939, Warren Denning was appointed to Canberra as the first ABC political correspondent, after Murdoch had refused to allow his newspapers to cover a speech by Joseph Lyons.
In 1942 "The Australian Broadcasting Act" was passed, giving the ABC the power to decide when, and in what circumstances, political speeches should be broadcast. Directions from the Minister about whether or not to broadcast any matter now had to be made in writing, and any exercise of the power had to be mentioned in the Commission's Annual Report. It was used only once, in 1963. In the same year, "Kindergarten of the Air" began on ABC Radio in Perth, and was later broadcast nationally. In 1944 18-year-old Patricia Delaney, of Sydney, was the Australian Broadcasting Corporation's only girl cadet announcer, and the youngest member of announcing staff.
The ABC commenced television broadcasting in 1956, and followed the earlier radio practice of naming the station after the first letter of the base state. ABN-2 (New South Wales) Sydney was inaugurated by Prime Minister Robert Menzies on 5 November 1956, with the first broadcast presented by Michael Charlton, and James Dibble reading the first television news bulletin. ABV-2 (Melbourne, Victoria) followed two weeks later, on 18 November 1956. Stations in other capital cities followed: ABQ-2 (Brisbane, Queensland) (1959), ABS-2 (Adelaide, South Australia) (1960), ABW-2 (Perth, Western Australia) (1960), and ABT-2 (Hobart, Tasmania) (1960). ABC-3 Canberra opened in 1961, and ABD-6 (Darwin, Northern Territory) started broadcasting in 1971, both named after the base city.
Although radio programs could be distributed nationally by landline, television relay facilities were not in place until the early 1960s. This meant that news bulletins had to be sent to each capital city by teleprinter, to be prepared and presented separately in each city, with filmed materials copied manually and sent to each state. Other television programs at the time included the popular "Six O'Clock Rock" hosted by Johnny O'Keefe, "Mr. Squiggle", as well as operas and plays.
In 1973 New South Wales Rugby League boss Kevin Humphreys negotiated rugby league's first television deal with the ABC.
In 1975, colour television was permanently introduced into Australia after experimental colour broadcasts since 1967, and within a decade the ABC had moved into satellite broadcasting, greatly enhancing its ability to distribute content nationally. In the same year, the ABC introduced a 24-hour-a-day AM rock station in Sydney, 2JJ (Double Jay), which was eventually expanded into the national Triple J FM network. A year later, a national classical music network was established on the FM band, broadcasting from Adelaide. It was initially known as ABC-FM (now called ABC Classic FM) – referring both to its 'fine music' programming and radio frequency.
ABC budget cuts began in 1976 and continued until 1985. In 1978 the ABC NSW Staff Association organised a strike against budget cuts and political interference. Sydney ABC was off air for four days. A packed free concert in support was held at the Regent Theatre and compered by Bob Hudson. It featured Fred Dagg and Robyn Archer. In 1991, Tom Molomby wrote:
The "Australian Broadcasting Corporation Act 1983" changed the name of the organisation from the "Australian Broadcasting Commission" to the "Australian Broadcasting Corporation", effective 1 July 1983. At the same time, the newly formed Corporation underwent significant restructuring. The ABC was split into separate television and radio divisions, with an overhaul of management, finance, property and engineering. Geoffrey Whitehead was the initial managing director; however, following his resignation in 1986, David Hill (at the time chair of the ABC Board) took over his position.
Program production in indigenous affairs, comedy, social history and current affairs was significantly expanded, while the Corporation's output of drama was boosted. Local production trebled from 1986–91 with the assistance of co-production, co-financing, and pre-sales arrangements.
A new Concert Music Department was formed in 1985 to co-ordinate the corporation's six symphony orchestras, which in turn received a greater level of autonomy to better respond to local needs. Open-air free concerts and tours, educational activities, and joint ventures with other music groups were undertaken at the time to expand the orchestras' audience reach.
ABC Radio was restructured significantly again in 1985 – Radio One became the Metropolitan network, while Radio 2 became known as Radio National (callsigns, however, were not standardised until 1990). New programs such as "The World Today", "Australia All Over", and "The Coodabeen Champions" were introduced, while ABC-FM established an Australian Music Unit in 1989. Radio Australia began to focus on the Asia-Pacific region, with coverage targeted at the south west and central Pacific, south-east Asia, and north Asia. Radio Australia also carried more news coverage, with special broadcasts during the 1987 Fijian coup, Tiananmen Square massacre, and the First Gulf War.
In 1991, the Corporation's Sydney radio and orchestral operations moved to a new building in the inner-city suburb of Ultimo. In Melbourne, the ABC Southbank Centre was completed in 1994, and now houses the radio division in Victoria as well as the Melbourne Symphony Orchestra.
The ABC Multimedia Unit was established in July 1995, to manage the new ABC website (launched in August). Funding was allocated later that year specifically for online content, as opposed to reliance on funding for television and radio content. The first online election coverage was put together in 1996, and included news, electorate maps, candidate information and live results.
By the early 1990s, all major ABC broadcasting outlets moved to 24-hour-a-day operation, while regional radio coverage in Australia was extended with 80 new transmitters. Live television broadcasts of selected parliamentary sessions started in 1990. ABC NewsRadio, a continuous news network broadcast on the Parliamentary and News Network when parliament is not sitting, was launched on 5 October 1994.
International television service Australia Television International was established in 1993, while at the same time Radio Australia increased its international reach. Reduced funding in 1997 for Radio Australia resulted in staff and programming cuts.
"Australia Television" was sold to the Seven Network in 1998, however the service continued to show ABC news and current affairs programming up until its closure in 2001. The ABC's television operation joined its radio and online divisions at the corporation's Ultimo headquarters in 2000.
In 2001, digital television commenced after four years of preparation. In readiness, the ABC had fully digitised its production, post-production and transmission facilities – heralded at the time as "the greatest advance in television technology since the introduction of colour". The first programmes to be produced in widescreen were drama series "Something in the Air", "Grass Roots" and "In the Mind of the Architect".
At the same time, the ABC's Multimedia division was renamed "ABC New Media", becoming an output division of the ABC alongside Television and Radio. Legislation allowed the ABC to provide 'multichannels' – additional, digital-only, television services managed by the New Media Division. Soon after the introduction of digital television in 2001, Fly TV and the ABC Kids channel launched, showing a mix of programming aimed at teenagers and children.
In 2002, the ABC launched ABC Asia Pacific – the replacement for the defunct Australia Television International operated previously by the Seven Network. Much like its predecessor, and companion radio network Radio Australia, the service provided a mix of programming targeted at audiences throughout the Asia-Pacific region. Funding cuts in 2003 led to the closure of Fly TV and the ABC Kids channel.
The ABC launched a digital radio service, ABC DiG, in November 2002, available though the internet and digital television, but not available through any other terrestrial broadcast until DAB+ became available in 2009.
ABC2, a second attempt at a digital-only television channel, launched on 7 March 2005. Unlike its predecessors the new service was not dependent on government funding, instead running on a budget of A$3 million per year. Minister for Communications Helen Coonan inaugurated the channel at Parliament House three days later. Genre restrictions limiting the types of programming the channel could carry were lifted in October 2006 – ABC2 was henceforth able to carry programming classified as comedy, drama, national news, sport and entertainment.
A high incidence of breast cancer in female staff working at the ABC's offices in Brisbane led to the closure of the site, based in Toowong, on 21 December 2006. Sixteen women were diagnosed with the disease in a period spanning 1994 to 2007. A progress report released in March 2007 by an independent panel formed to investigate the occurrences found that the rate of occurrence for breast cancer rate at the offices was eleven times higher than elsewhere – after the closure of the site, the ABC's Brisbane-based television and radio operations were moved to alternate locations around the city, including Ten Brisbane's studios at Mt Coot-tha. The ABC's managing director, Mark Scott, announced in August 2007 that new studios would be built on the site, following the final release of the Review and Scientific Investigation Panel's report. In January 2012 the ABC in Brisbane moved into purpose-built accommodation in South Bank.
On 8 February 2008, ABC TV was rebranded as ABC1, complementing the existing ABC2 digital-only channel which was launched on 7 March 2005. Branding was also added for a new kids' channel that had been announced throughout the Howard Government based on their winning the 2007 election but left to the 2009 Rudd Government Budget where ABC3 was funded and announced in June. A new online video-on-demand service launched in July of the same year, titled ABC iview, and the ABC launched digital radio broadcasts in the same month.
In 2006, the definitive history of the ABC by Ken Inglis was issued by Black Inc., re-issuing the 1983 edition of "This is the ABC - 1932-1983" and issuing his "Whose ABC - 1983-2006". These tomes combined to give a comprehensive overview of the ABC's history to that year.
ABC News launched on 22 July 2010, and brought with it both new programming content as well as a collaboration of existing news and current affair productions and resources. The ABC launched the 24-hour news channel to both complement its existing 24-hour ABC News Radio service and compete with commercial offerings on cable TV. It became the ABC's fifth domestic TV channel and the fourth launched within the past 10 years.
On 20 July 2014, ABC1 reverted to its original name of ABC TV.
In 2014 the ABC ran its first "Mental As" week focusing on improving awareness of mental health issues, as part of Mental Health Week.
In December 2015 it was announced that former BSkyB, Star TV and Google executive Michelle Guthrie would take over from managing director Mark Scott, who was to retire in April 2016.
In June 2018, the Liberal Party's annual federal council voted to privatise the ABC. The decision is not binding on the federal government, so is seen as unlikely to impact government policy.
In September 2018 it was announced that Michelle Guthrie had left the position of Managing Director, after ""directors resolved that it was not in the best interests of the ABC for Ms Guthrie to continue to lead the organisation"".
It was reported in February 2019 that Australian prime minister, Scott Morrison, has been given a shortlist of potential candidates for the role of ABC Chairman after the company has gone without a chairman or managing director for over four months. The recruitment process has been started by the global recruitment firm, Korn Ferry. The final choice for chairman has yet to be sent to the cabinet for approval. The ABC board has started the search for a new managing director even though the chairman has yet to be appointed. Ita Buttrose has been named the new chairwoman of the ABC, pending formal approval from the Governor-General.
Below is a diagram of the ABC's divisional structure.
The operations of the ABC are governed by a board of directors, consisting of a managing director, five to seven directors, and until 2006, a staff-elected director. The managing director is appointed by the board for a period of up to five years, but is eligible for renewal. The authority and guidelines for the appointment of directors is provided for in the "Australian Broadcasting Corporation Act 1983".
Appointments to the ABC Board made by successive governments have often resulted in criticism of the appointees' political affiliation, background, and relative merit. Past appointments have associated directly with political parties – five of fourteen appointed chairmen have been accused of political affiliation or friendship, include Richard Downing and Ken Myer (both of whom publicly endorsed the Australian Labor Party at the 1972 election), as well as Sir Henry Bland. David Hill was close to Neville Wran, while Donald McDonald was considered to be a close friend of John Howard.
From 2003 the Howard Government made several controversial appointments to the ABC Board, including prominent ABC critic Janet Albrechtsen, Ron Brunton, and Keith Windschuttle.
During their 2007 federal election campaign, Labor announced plans to introduce a new system, similar to that of the BBC, for appointing members to the board. Under the new system, candidates for the ABC Board would be considered by an independent panel established "at arm's length" from the Communications Minister. If the minister chose someone not on the panel's shortlist, they would be required to justify this to parliament. The ABC chairman would be nominated by the prime minister and endorsed by the leader of the opposition.
The new merit-based appointment system was announced on 16 October, in advance of the new triennial funding period starting in 2009.
Current board members are:
The ABC is funded mainly by the Australian government, in addition to some revenue received from its retail outlets. Government funding to the ABC was $1,036.1 million in 2016–17; $1,043.7 million in 2017–18; and is estimated at $1,045.9 million in 2018–19.
Until 1948, the ABC was funded directly by radio licence fees; amendments were also made to the "Australian Broadcasting Act" that meant the ABC would receive its funding directly from the federal government. Licence fees remained until 1973 when they were abolished by the Whitlam Labor government, on the basis that the near-universality of television and radio services meant that public funding was a fairer method of providing revenue for government-owned radio and television broadcasters.
The term "where your 8 cents a day goes", coined in the late 1980s during funding negotiations, is often used in reference to the services provided by the ABC. It is estimated that the cost of the ABC per head of population per day was 7.1 cents a day, based on the Corporation's 2007–08 'base funding' of $543 million. Based on funding of $1043.7m in 2017/18 and an Australian population of 24.8m. A more current calculation gives a cost of about 4 cents a day.
Under the "Australian Broadcasting Corporation Act 1983", the ABC Board is bound to "maintain the independence and integrity of the Corporation" and to ensure that "the gathering and presentation by the Corporation of news and information is accurate and impartial according to the recognized standards of objective journalism."
In relation to impartiality and diversity of perspectives, the current ABC editorial policy requires of the broadcaster that:
As a publicly funded broadcaster, the ABC is expected not to take editorial stances on political issues, and is required to present a range of views with impartiality. Over the decades, accusations of "bias" at the ABC have arisen at different times, and various inquiries undertaken.
Reviews of the ABC are regularly commissioned and sometimes not released.
The ABC's requirement of impartiality has led to persistent debates. External critics have complained in particular of left-wing political bias at the broadcaster, citing a prominence of Labor Party-connected journalists hosting masthead political programs or a tendency to favour "progressive" over "conservative" political views on issues such as immigration, refugees, the republic, multiculturalism, reconciliation, feminism, environmentalism, anti-Americanism, gay marriage, budgeting and the like.
There have been internal and external research on the question of bias at the ABC. A 2013 University of the Sunshine Coast study of the voting intentions of journalists found that 73.6 per cent of ABC journalists supported Labor or The Greens - with 41% supporting the Greens (whereas only around 10% of people in the general population voted Green). A 2004 Roy Morgan media credibility survey found that journalists regarded ABC Radio as the most accurate news source in the country and the ABC as the second "most politically biased media organisation in Australia". Former Prime Minister of Australia Malcolm Turnbull commented on 3AW radio in 2018 that "some" journalists and programs "contain a left-wing bias."
Commentators such as Andrew Bolt, Tim Blair and Gerard Henderson accuse the ABC of a left-wing bias. In rejecting criticisms of bias, ABC journalist Annabel Crabb said in 2015 that the organisation gives "voices to Australians who otherwise wouldn't be heard, on topics that are too uncommercial or too remote or too hard to be covered by anyone else, broadcasting into areas from which others have long withdrawn resources". ABC journalist turned NSW Liberal MLA Pru Goward said of the organisation: " I have no doubt there was left-wing bias, I certainly thought it when I was there", while ABC journalist turned Federal Labor politician Maxine McKew said there was no left wing bias, though "what I detected years ago in the ABC, much more of a collectivist philosophy". However former ABC Chairman Maurice Newman says, "the ABC bias is absolutely palpable" and "the ABC is now ‘shameless’ and there is no attempt to bring balance to its programs".
At the 2016 federal election, a study commissioned by the ABC and conducted by iSentia compiled share-of-voice data and found that the ABC devoted 42.6% of election coverage to the Coalition government (this compares to the 42.04% vote received by the Coalition in the House of Representatives (HOR)), 35.9% to the Labor opposition (34.73% HOR), 8% to the Greens (10.23% HOR), 3.1% to independents (1.85% HOR), 2.2% to Nick Xenophon's Team (1.85% HOR) and 8.1% to the rest. However, the ABC itself notes the "significant limitations around the value of share of voice data" as "duration says nothing about tone or context".
Labor Prime Minister Bob Hawke considered the ABC's coverage of the 1991 Gulf War to be biased. In 1996, conservative Opposition Leader John Howard refused to have Kerry O'Brien of the ABC moderate the television debates with Labor Prime Minister Paul Keating because Howard saw O'Brien as biased against the Coalition.
During the subsequent Howard Government years, ABC TV's masthead political programs were anchored by journalists with Labor affiliations: the "7.30 Report" was hosted by former Whitlam staffer Kerry O'Brien; the "Insiders" program by former Hawke staffer Barrie Cassidy and the "Lateline" program by Maxine McKew who went on to defeat Liberal Prime Minister John Howard as the Labor candidate for the seat of Bennelong in 2007, at the same time as ABC Sydney News weatherman Mike Bailey ran for Labor against Liberal minister Joe Hockey.
In the subsequent Rudd-Gillard period, Cassidy retained his position at "Insiders", while O'Brien shifted to host "Four Corners" in 2011.
Chris Uhlmann, husband of Labor MP Gai Brodtmann, was appointed as co-host of the "7.30" current affairs program, and Sydney ABC News anchor Juanita Phillips began a relationship with Labor's Minister for Climate Change, Greg Combet.
Liberal Prime Minister Tony Abbott perceived the ABC to be left wing and hostile to his government, while his successor Malcolm Turnbull enjoyed better relations with the National Broadcaster. When the ABC co-published stolen documents purportedly revealing Australian spy agency activities overseas, Abbott told 2GB radio: "people feel at the moment that the ABC instinctively takes everyone's side but Australia's". He reportedly called the "Q&A" program a "Lefty Lynch Mob". Abbott denounced the program for inviting Zaky Mallah, a man convicted of threatening Commonwealth officials, to participate in questioning one of his ministers, asking: "whose side are you on?". Abbott initiated a brief ministerial boycott of the "Q&A" program following the affair.
The broadcaster was critical of Abbott when he broke an election-eve promise not to make cuts to the ABC as part of his "Budget repair" program. In early 2015, an internal ABC review of its coverage of Joe Hockey's first Budget criticised the post-budget interviews by "7:30" and "Lateline", finding that the interviewers had given the impression of bias.
When Abbott lost the leadership to the less conservative Turnbull in the September 2015 Liberal leadership spill, the hosts of the ABC's political programs spoke in favour of Abbott's demise. Kerry O'Brien and Barrie Cassidy, hosts respectively of the ABC's flagship weekly current affairs programs "Four Corners" and "Insiders", welcomed the replacement of Abbott by Turnbull, as did ABC radio commentators Fran Kelly Paul Bongiorno and Amanda Vanstone. Fairfax and News Limited reported that Leigh Sales, the host of "7.30" gave Turnbull an unusually warm first interview following his toppling of Abbott.
When Turnbull lost the leadership after a conservative challenge in August 2018, the hosts of the ABC's political programs denounced the change. The 7pm News political correspondent Andrew Probyn, who had been censured by ACMA earlier in the year for biased reporting against Abbott, said the removal of Turnbull was about "vengeance pure and simple". Earlier in the year. "Insiders"' Barrie Cassidy called it "insanity and madness". "7:30" Chief Political Correspondent Laura Tingle was selected by Turnbull first among a handful of journalists to ask questions at his final press conference. She said "one of frustrations that voters have had with your prime ministership is the sense that you have conceded too regularly to the conservatives" Vanstone called the challenge "disgraceful".
In a March 2016 interview with ABC Managing Director Mark Scott, "Media Watch" host Paul Barry examined the question of perceptions of left wing bias at the ABC. Scott noted that while perhaps the ABC was more concerned about gay marriage than about electricity prices, he did not accept the criticism of bias because "a lot of that criticism comes from right wing commentators and they wonder where are the strong right wing commentators on the ABC. We don't do that kind of journalism. We don't ask questions about our journalists' voting pattern and where their ideology are. We look at the journalism that they put to air and we have strong editorial standards..." Following the interview, conservative ABC critic Andrew Bolt wrote "How can the man heading our biggest media organisation be so blind to the ABC's unlawful and dangerous Leftist bias?" while former "Media Watch" host Jonathan Holmes wrote for "The Age" that this interview indicated that ABC management had failed to recognise a clear problem of left wing bias among some capital city radio presenters.
Over the period, ABC TV and radio hosts advocated strongly in support of same-sex marriage, upon which the wider Australian community and political parties were divided. When the Turnbull Government announced plans for a postal plebiscite on the issue, advocacy for change continued, prompting a call for restraint from the ABC's editorial policy manager Mark Maley.
An interview by ABC presenter Joe O'Brien with Lyle Shelton was the subject of a complaint by the Australian Christian Lobby. Bringing up Ian Thorpe's swimming achievements, O'Brien asked Shelton "what right do you have to participate in that joy, and take national pride in those achievements, if you now deny him the right to feel like an equal and experience the joy of marriage?" In rejecting any perceived bias, the ABC said "It was a 'devil's advocate' question and not inconsistent with standards".
The ABC is criticised for allegedly giving undue support to opposition to Australia Day being held on 26 January. In 2017, the ABC's youth radio network announced that, after extensive consultation and opinion polling, it would no longer play its Hottest 100 Australian music list on Australia Day, choosing instead to broadcast the playlist on the fourth weekend in January. The Federal Communications Minister Mitch Fifield said in response "I am bewildered by the ABC's decision to move the Hottest 100 from Australia Day. The ABC shouldn't be buying into this debate. Australia Day is our national day. The ABC should honour it and not mess with the Hottest 100." In 2018, an opinion piece appeared on ABC's website suggesting the date should be moved to 1 January, citing symbolism. Justin Milne, the chair of the ABC Board, held a meeting trying to convince the board to overrule Triple J's decision.
The ABC's coverage of the Catholic Church has been controversial. The Archbishop of Brisbane, Mark Coleridge, condemned the ABC in 2017 for an "antagonistic, one-sided narrative" of the Catholic Church. Gerard Henderson of the Sydney Institute has written that "The ABC's focus on historic child sexual abuse in the Catholic Church stands in contrast to its failure to cover the public broadcaster’s own history in this area." In the aftermath of the wrongful conviction of Adelaide archbishop Phillip Wilson in 2018, and the wrongful conviction of Cardinal George Pell by a jury in 2019, journalist Paul Kelly wrote that "calculated media assaults on Pell" had been "spearheaded by the ABC", contributing to an intense and unjustified public hatred of the Catholic leader and prejudicial environment in which to conduct a trial.
The ABC's coverage of the issue has also won praise including the awarding of the 'Melbourne Press Club 2016 Quill for Coverage of an Issue or Event for the report 'George Pell and Sexual Abuse in the Catholic Church' and the 2016 Golden Quill award to Louise Milligan & Andy Burns for their extensive coverage of Cardinal George Pell's evidence given at the Royal Commission into Institutional Responses to Child Sexual Abuse. In awarding the prize judges noted ""Their interviews with victims were compelling, moving and handled with great humanity. The work delivered a series of scoops, including detailed allegations about the conduct of Cardinal George Pell. This is journalism at its best: giving voice to those who have long suffered in silence.""
Initial reports into the accusations against Cardinal Pell were broken by the Herald Sun in February 2016 with the ABC first covering the story in July that year on the program 7.30 which featured two alleged victims. Cardinal Pell was invited to participate however declined and instead issued a statement . The ABC News and Current Affairs programs provided coverage of the investigation and trial of Pell, in particular Four Corners in March 2019 and the series Revelation in 2020. In its statement the ABC maintained “In every case, Cardinal Pell was made aware of all the allegations against him well before the programs were broadcast and given every opportunity to address and respond to them.”. In a review of the programming the ABC noted “Obtaining interviews with Cardinal Pell’s supporters was not always easy; reporters and producers covering the case for ABC News, local radio and daily current affairs often had interview requests declined. Nonetheless, many of the Cardinal’s most prominent supporters have regularly appeared on major ABC programs, and the ABC’s coverage has consistently included a wide diversity of voices, accurate news and authoritative analysis of the many complex legal issues raised by the case”
In the aftermath of the unanimous acquittal of Cardinal George Pell by the High Court of Australia in 2020, Cardinal Pell and a variety of commentators accused the ABC of sustained bias against him and of "abuse of power". Asked on Sky News if the ABC's "persecution" concerned him, the Cardinal replied: "Yes it does, because, I mean, it's partly financed by Catholic taxes... in a national broadcaster to have an overwhelming presentation of one view, and only one view, I think that's a betrayal of the national interest." Australian Catholic University vice-chancellor Greg Craven accused the ABC of being "virulent" in creating "an atmosphere conducive to a conviction."
In response the ABC conducted an editorial and legal review of its coverage where it rejected the accusation of bias, and defended its reporting of Pell as having been "without fear or favour". A number of ABC presenters and reporters expressed disappointment about the acquittal on personal social media accounts and in the press. ABC Media Watch's Paul Barry reported: "and to prove that point perhaps, two ex-ABC [sic] titans Barrie Cassidy and Quentin Dempster took to Twitter to declare that just because the high court unanimously acquitted Cardinal Pell that did not mean he was innocent. Technically that may be right but the principle of our legal system is you’re innocent until proven guilty" ABC reporter Louise Milligan, author of "Cardinal: The Rise and Fall of George Pell", asked her Twitter followers to "Hug your children" after the High Court published its judgment. Greg Sheridan wrote for "The Australian": "Milligan, an ABC journalist, wrote a book damning Pell. It too was based in part on allegations now dismissed in court. Yet she was used on the ABC as though she were an impartial reporter... Milligan’s book was never searchingly critiqued on the ABC. Given the massive power of the ABC, this is an abuse of power".
Paul Kelly wrote: "The job of the ABC was to inform and educate on one of the most contentious trials in the past half-century. Instead, it campaigned against Pell, essentially offering a one-sided condemnatory view in a coverage that was extensive, powerful and influential with the public." Tony Thomas wrote for "Quadrant": "The producers’ tricks include hard editing of material favourable to Pell and long lingering on adverse material." Gerard Henderson wrote: "The ABC led the campaign in programs such as 7.30, Four Corners, Lateline (as it then was), Q&A, News Breakfast and Radio National Breakfast."
Summarising his case against the ABC's coverage of Pell, Conservative Commentator Greg Sheridan wrote on 16 April:
A number of former journalists and presenters have moved from positions at the ABC to politics.
State Labor premiers and chief ministers Bob Carr,
Alan Carpenter,
and Clare Martin are all former ABC journalists. Other ABC journalists who stood as Labor candidates include Mary Delahunty, Maxine McKew, Mike Bailey, Ian Baker, Leon Bignell, John Bowler, Bob Debus, Malarndirri McCarthy, Frank McGuire, Neville Oliver and Diana Warnock. Senior ABC political reporter Kerry O'Brien was press secretary to Labor prime minister Gough Whitlam and Labor deputy leader Lionel Bowen and Barrie Cassidy was press secretary to Labor prime minister Bob Hawke. Susan Templeman's husband, Ron Fuller, is the former Chief of Staff for ABC TV News. Radio National's Phillip Adams is a former member of the Communist Party of Australia and the Labor Party, and Melbourne ABC radio's Jon Faine is a former member of the Labor Party.
On the Coalition side of politics, Pru Goward has served as a Minister in the NSW state Liberal Government, Rob Messenger, Peter Collins, Eoin Cameron, Scott Emerson and Sarah Henderson all held, or hold, positions at the ABC. Radio National's "Counterpoint" program is hosted by former Liberal minister Amanda Vanstone, who describes herself as "liberal" rather than "conservative".
Research undertaken by the broadcaster in 2007 indicated that out of a total of 19 former employees moving into party political positions, 10 have joined the Labor Party and nine the Liberal Party.
"Planet Slayer" was a controversial environmentalist website for children owned by ABC. The site featured a "Greenhouse Calculator" which says the age a person needs to die if they are not to "overuse their share of the earth". The site has also been criticized for attacking those who eat meat, blue collared workers such as loggers, and nuclear energy. ABC managing director Mark Scott said the site was not designed to offend anyone, but instead have children think about environmental issues.
On 5 June 2019, police raided the headquarters of the ABC looking for articles written in 2017 about alleged misconduct by Australian forces in Afghanistan. Search warrants naming two journalists and news director Gaven Morris were issued.
The raid was countered by lawyers for the ABC challenging the examination of over 9,200 documents, including internal emails.
The ABC operates 54 local radio stations, in addition to four national networks and international service Radio Australia. In addition, DiG Radio launched on digital platforms in 2002, currently offering three separate stations.
ABC Local Radio is the Corporation's flagship radio station in each broadcast area. There are 54 individual stations, each with a similar format consisting of locally presented light entertainment, news, talk back, music, sport and interviews, in addition to some national programming such as "AM", "PM", "The World Today", sporting events and "Nightlife".
The ABC operates four national radio networks, available on AM and FM as well as on digital platforms and the internet.
ABC Radio broadcasts regular news bulletins across most of its radio stations. Many of these bulletins are heralded by the "Majestic Fanfare", written by British composer Charles Williams in 1935.
In addition to these, there is also Radio Australia, the international radio station of the ABC.
The ABC also operates several stations only available online and on digital platforms, as listed below.
The ABC operates 5 national television channels.
Although the ABC's headquarters in Sydney serve as a base for program distribution nationally, ABC Television network is composed of eight state- and territory-based stations, each based in their respective state capital and augmented by repeaters:
The eight ABC stations carry opt outs for local programming. In addition to the nightly 7pm news, the stations also broadcast weekly state editions of "7.30" on Friday evenings (until 5 December 2014), state election coverage and in most areas, live sport on Saturday afternoons.
The ABC operates ABC Studios. ABC, the corporation's original television service, receives the bulk of funding for television and shows first-run news, and ABC Kids.
An experimental Multimedia Unit was established in 1995, charged with developing policy for the ABC's work in web publishing. This unit continued until 2000, when the New Media division was formed, bringing together the ABC's online output as a division similar to Television or Radio. The division had over a million pages of material published by late 2003.
In 2001 the New Media division became New Media and Digital Services, reflecting the broader remit to develop content for digital platforms such as digital television. In addition to ABC Online, the division also had responsibility over the ABC's two digital television services, Fly TV and the ABC Kids channel, until their closure in 2003. In March 2005 the division oversaw the launch of ABC2, a free-to-air digital television channel, in effect a replacement for ABC Kids and Fly.
In conjunction with the ABC's radio division, New Media and Digital Services implemented the ABC's first podcasts in December 2004. By mid-2006 the ABC had become an international leader in podcasting with over fifty podcast programmes delivering hundreds of thousands of downloads per week, including trial video podcasts of The Chaser's War on Everything and jtv.
In February 2007, the New Media & Digital Services division was dissolved and divided up amongst other areas of the ABC. It was replaced by a new Innovation division, to manage ABC Online and investigate new technologies for the ABC.
In 2015 the Innovation division was replaced with the Digital Network division.
ABC Australia is an international satellite television service operated by the Australian Broadcasting Corporation, funded by advertising and grants from the Department of Foreign Affairs and Trade. Aimed at the Asia-Pacific region, the service broadcasts a mixture of English language programming, including general entertainment, sport, and current affairs.
ABC Radio Australia is an international satellite and internet radio service with transmissions aimed at East Asia and the Pacific Islands, although its signals are also audible in many other parts of the world. It features programmes in various languages spoken in these regions, including Mandarin, Indonesian, Vietnamese, Khmer and Tok Pisin. Before 31 January 2017 Radio Australia broadcast shortwave radio signals which were terminated in favour of online and satellite radio.
Radio Australia bulletins are also carried on WRN Broadcast, available via satellite in Europe and North America.
ABC Commercial is the division of the ABC responsible for pursuing new sources of revenue for the Corporation. It comprises ABC Retail, ABC Content Sales and Distribution, ABC Publishing and Licensing, ABC Music and Events, and ABC Studio and Media Productions. ABC retail outlets were established in 1974, and closed in 2015. All profits from the sale of consumer product and production services return to the Corporation to reinvest in programme making.
Up until the installation of disc recording equipment in 1935, all content broadcast on the ABC was produced live, including music. For this purpose, the ABC established broadcasting orchestras in each state, and in some centres also employed choruses and dance bands. This became known as the ABC Concert Music Division, which was controlled by the Federal Director of Music – the first of whom was W. G. James.
There are currently six state symphony orchestras:
The orchestras were corporatised in the 1990s, and were divested into independent companies on 1 January 2007.
The ABC logo is one of the most recognisable logos in Australia. In the early years of television, the ABC had been using Lissajous curves as fillers between programmes. In July 1963, the ABC conducted a staff competition to create a new logo for use on television, stationery, publications, microphone badges and ABC vehicles. In 1965, ABC graphics designer Bill Kennard submitted a design representing a Lissajous display, as generated when a sine wave signal is applied to the "X" input of an oscilloscope and another at three times the frequency at the "Y" input. The letters "ABC" were added to the design and it was adopted as the ABC's official logo. Kennard was presented with £25 for his design.
On 19 October 1974, the Lissajous curve design experienced its first facelift with the line thickened to allow for colour to be used. It would also be treated to the ‘over and under’ effect, showing the crossover of the line in the design. This logo would be served as the longest-running design with a lifespan of 44 years and 28 on its first on-air run. To celebrate its 70th anniversary on 1 July 2002, the ABC adopted a new logo, which was created by (Annette) Harcus Design in 2001. This logo utilized a silver 3D texture but the crossover design was left intact. This logo would then be used across the ABC's media outlets. However, some brands may continue to use this logo. The 2002 silver logo is no longer in use by the corporation, with the exception of some of the ABC's radio station logos. After the on-air revival of the 1974 logo since 2014, the ABC gradually reinstated the classic symbol while using a new logotype in 2018. The change comes with a press release that the ABC released on 12 February announcing a new brand positioning under its tagline, "Yours". | https://en.wikipedia.org/wiki?curid=3079 |
Alexandria
Alexandria ( or ; ; ; Coptic: Rakodī; "Alexandria") is the second-largest city in Egypt and a major economic center. With a population of 5,200,000, Alexandria is the largest city on the Mediterranean, the sixth-largest city in the Arab world and the ninth-largest in Africa. The city extends about at the northern coast of Egypt along the Mediterranean Sea. Alexandria is a popular tourist destination, and also an important industrial center because of its natural gas and oil pipelines from Suez.
Alexandria was founded in by Alexander the Great, king of Macedon and leader of the Greek League of Corinth, during his conquest of the Achaemenid Empire. An Egyptian village named Rhacotis existed at the location and grew into the Egyptian quarter of Alexandria. Alexandria grew rapidly to become an important center of Hellenistic civilization and remained the capital of Ptolemaic Egypt and Roman and Byzantine Egypt for almost 1,000 years, until the Muslim conquest of Egypt in AD 641, when a new capital was founded at Fustat (later absorbed into Cairo). Hellenistic Alexandria was best known for the Lighthouse of Alexandria ("Pharos"), one of the Seven Wonders of the Ancient World; its Great Library (the largest in the ancient world); and the Necropolis, one of the Seven Wonders of the Middle Ages. Alexandria was the intellectual and cultural center of the ancient Mediterranean world for much of the Hellenistic age and late antiquity. It was at one time the largest city in the ancient world before being eventually overtaken by Rome.
The city was a major center of early Christianity and was the center of the Patriarchate of Alexandria, which was one of the major centers of Christianity in the Eastern Roman Empire. In the modern world, the Coptic Orthodox Church and the Greek Orthodox Church of Alexandria both lay claim to this ancient heritage.
Following the Arab conquest of Egypt in AD 641, the city was plundered and lost its significance before re-emerging in the modern era. From the late 18th century, Alexandria became a major center of the international shipping industry and one of the most important trading centers in the world, both because it profited from the easy overland connection between the Mediterranean Sea and the Red Sea, and the lucrative trade in Egyptian cotton.
Recent radiocarbon dating of seashell fragments and lead contamination show human activity at the location during the period of the Old Kingdom (27th-21st centuries BC) and again in the period 1000-800 BC, followed by the absence of activity thereafter. From ancient sources it is known there existed a trading post at this location during the time of Rameses the Great for trade with Crete, but it had long been lost by the time of Alexander's arrival. A small Egyptian fishing village named Rhakotis (Egyptian:*Raˁ-Ḳāṭit, written "rˁ-ḳṭy.t", 'That which is built up') existed since the 13th century BC in the vicinity and eventually grew into the Egyptian quarter of the city. Just east of Alexandria (where Abu Qir Bay is now), there was in ancient times marshland and several islands. As early as the 7th century BC, there existed important port cities of Canopus and Heracleion. The latter was recently rediscovered under water.
Alexandria was founded by Alexander the Great in April 331 BC as ("Alexandreia"). Passing through Egypt, Alexander wanted to build a large Greek city on Egypt's coast that would bear his name. He chose the site of Alexandria, envisioning the building of a causeway to the nearby island of Pharos that would generate two great natural harbors. Alexandria was intended to supersede Naucratis as a Hellenistic center in Egypt, and to be the link between Greece and the rich Nile valley. A few months after the foundation, Alexander left Egypt and never returned to the city during his life.
After Alexander's departure, his viceroy Cleomenes continued the expansion. The architect Dinocrates of Rhodes designed the city, using a Hippodamian grid plan. Following Alexander's death in 323 BC, his general Ptolemy Lagides took possession of Egypt and brought Alexander's body to Egypt with him. Ptolemy at first ruled from the old Egyptian capital of Memphis. In 322/321 BC he had Cleomenes executed. Finally, in 305 BC, Ptolemy declared himself Pharaoh as Ptolemy I Soter ("Savior") and moved his capital to Alexandria.
Although Cleomenes was mainly in charge of overseeing Alexandria's early development, the "Heptastadion" and the mainland quarters seem to have been primarily Ptolemaic work. Inheriting the trade of ruined Tyre and becoming the center of the new commerce between Europe and the Arabian and Indian East, the city grew in less than a generation to be larger than Carthage. In a century, Alexandria had become the largest city in the world and, for some centuries more, was second only to Rome. It became Egypt's main Greek city, with Greek people from diverse backgrounds.
Alexandria was not only a center of Hellenism, but was also home to the largest urban Jewish community in the world. The Septuagint, a Greek version of the Tanakh, was produced there. The early Ptolemies kept it in order and fostered the development of its museum into the leading Hellenistic center of learning (Library of Alexandria), but were careful to maintain the distinction of its population's three largest ethnicities: Greek, Jewish, and Egyptian. By the time of Augustus, the city walls encompassed an area of 5.34 km, and the total population in Roman times was around 500–600,000.
According to Philo of Alexandria, in the year 38 of the Common era, disturbances erupted between Jews and Greek citizens of Alexandria during a visit paid by the Jewish king Agrippa I to Alexandria, principally over the respect paid by the Jewish nation to the Roman emperor, and which quickly escalated to open affronts and violence between the two ethnic groups and the desecration of Alexandrian synagogues. The violence was quelled after Caligula intervened and had the Roman governor, Flaccus, removed from the city.
In AD 115, large parts of Alexandria were destroyed during the Kitos War, which gave Hadrian and his architect, Decriannus, an opportunity to rebuild it. In 215, the emperor Caracalla visited the city and, because of some insulting satires that the inhabitants had directed at him, abruptly commanded his troops to put to death all youths capable of bearing arms. On 21 July 365, Alexandria was devastated by a tsunami (365 Crete earthquake), an event annually commemorated years later as a "day of horror".
In 619, Alexandria fell to the Sassanid Persians. Although the Byzantine Emperor Heraclius recovered it in 629, in 641 the Arabs under the general 'Amr ibn al-'As invaded it during the Muslim conquest of Egypt, after a siege that lasted 14 months. The first Arab governor of Egypt recorded to have visited Alexandria was Utba ibn Abi Sufyan, who strengthened the Arab presence and built a governor's palace in the city in 664–665.
After the Battle of Ridaniya in 1517, the city was conquered by the Ottoman Turks and remained under Ottoman rule until 1798. Alexandria lost much of its former importance to the Egyptian port city of Rosetta during the 9th to 18th centuries, and only regained its former prominence with the construction of the Mahmoudiyah Canal in 1807.
Alexandria figured prominently in the military operations of Napoleon's expedition to Egypt in 1798. French troops stormed the city on 2 July 1798, and it remained in their hands until the arrival of a British expedition in 1801. The British won a considerable victory over the French at the Battle of Alexandria on 21 March 1801, following which they besieged the city, which fell to them on 2 September 1801. Muhammad Ali, the Ottoman governor of Egypt, began rebuilding and redevelopment around 1810, and by 1850, Alexandria had returned to something akin to its former glory. Egypt turned to Europe in their effort to modernize the country. Greeks, followed by other Europeans and others, began moving to the city. In the early 20th century, the city became a home for novelists and poets.
In July 1882, the city came under bombardment from British naval forces and was occupied.
In July 1954, the city was a target of an Israeli bombing campaign that later became known as the Lavon Affair. On 26 October 1954, Alexandria's Mansheya Square was the site of a failed assassination attempt on Gamal Abdel Nasser.
Europeans began leaving Alexandria following the 1956 Suez Crisis that led to an outburst of Arab nationalism. The nationalization of property by Nasser, which reached its highest point in 1961, drove out nearly all the rest.
In reference to Alexandria, Egypt, Ibn Battuta speaks of great saints that resided here. One of them being Imam Borhan Oddin El Aaraj. He was said to have the power of working miracles. He told Ibn Battuta that he should go find his three brothers, Farid Oddin, who lived in India, Rokn Oddin Ibn Zakarya, who lived in Sindia, and Borhan Oddin, who lived in China. Battuta then made it his purpose to find these people and give them his compliments. Sheikh Yakut was another great man. He was the disciple of Sheikh Abu Abbas El Mursi, who was the disciple of Abu El Hasan El Shadali, who is known to be a servant of God. Abu Abbas was the author of the Hizb El Bahr and was famous for piety and miracles. Abu Abd Allah El Murshidi was a great interpreting saint that lived secluded in the Minyat of Ibn Murshed. He lived alone but was visited daily by emirs, viziers, and crowds that wished to eat with him. The Sultan of Egypt (El Malik El Nasir) visited him, as well. Ibn Battuta left Alexandria with the intent of visiting him.
Ibn Battuta also visited the Pharos lighthouse on 2 occasions; in 1326 he found it to be partly in ruins and in 1349 it had deteriorated further, making entrance to the edifice impossible.
The most important battles and sieges of Alexandria include:
Greek Alexandria was divided into three regions:
Two main streets, lined with colonnades and said to have been each about wide, intersected in the center of the city, close to the point where the Sema (or Soma) of Alexander (his Mausoleum) rose. This point is very near the present mosque of Nebi Daniel; and the line of the great East–West "Canopic" street, only slightly diverged from that of the modern Boulevard de Rosette (now Sharia Fouad). Traces of its pavement and canal have been found near the Rosetta Gate, but remnants of streets and canals were exposed in 1899 by German excavators outside the east fortifications, which lie well within the area of the ancient city.
Alexandria consisted originally of little more than the island of Pharos, which was joined to the mainland by a mole and called the "Heptastadion" ("seven stadia"—a "stadium" was a Greek unit of length measuring approximately ). The end of this abutted on the land at the head of the present Grand Square, where the "Moon Gate" rose. All that now lies between that point and the modern "Ras al-Tin" quarter is built on the silt which gradually widened and obliterated this mole. The Ras al-Tin quarter represents all that is left of the island of Pharos, the site of the actual lighthouse having been weathered away by the sea. On the east of the mole was the Great Harbor, now an open bay; on the west lay the port of Eunostos, with its inner basin Kibotos, now vastly enlarged to form the modern harbor.
In Strabo's time, (latter half of the 1st century BC) the principal buildings were as follows, enumerated as they were to be seen from a ship entering the Great Harbor.
The names of a few other public buildings on the mainland are known, but there is little information as to their actual position. None, however, are as famous as the building that stood on the eastern point of Pharos island. There, The Great Lighthouse, one of the Seven Wonders of the World, reputed to be high, was situated. The first Ptolemy began the project, and the second Ptolemy (Ptolemy II Philadelphus) completed it, at a total cost of 800 talents. It took 12 years to complete and served as a prototype for all later lighthouses in the world. The light was produced by a furnace at the top and the tower was built mostly with solid blocks of limestone. The Pharos lighthouse was destroyed by an earthquake in the 14th century, making it the second longest surviving ancient wonder, after the Great Pyramid of Giza. A temple of Hephaestus also stood on Pharos at the head of the mole.
In the 1st century, the population of Alexandria contained over 180,000 adult male citizens, according to a census dated from 32 CE, in addition to a large number of freedmen, women, children and slaves. Estimates of the total population range from 216,000 to 500,000 making it one of the largest cities ever built before the Industrial Revolution and the largest pre-industrial city that was not an imperial capital.
Alexandria is located in the country of Egypt, on the southern coast of the Mediterranean.
Alexandria has a borderline hot desert climate (Köppen climate classification: BWh), approaching a hot semi-arid climate (BSh). As the rest of Egypt's northern coast, the prevailing north wind, blowing across the Mediterranean, gives the city a less severe climate from the desert hinterland. Rafah and Alexandria are the wettest places in Egypt; the other wettest places are Rosetta, Baltim, Kafr el-Dawwar, and Mersa Matruh. The city's climate is influenced by the Mediterranean Sea, moderating its temperatures, causing variable rainy winters and moderately hot summers that, at times, can be very humid; January and February are the coolest months, with daily maximum temperatures typically ranging from and minimum temperatures that could reach . temperature sometimes gets lower than 5 and it sometimes rains snow.
Alexandria experiences violent storms, rain and sometimes sleet and hail during the cooler months; these events, combined with a poor drainage system, have been responsible for occasional flooding in the city in the past but don't happen anymore. July and August are the hottest and driest months of the year, with an average daily maximum temperature of .
The average annual rainfall is around but has been as high as
Port Said, Kosseir, Baltim, Damietta and Alexandria have the least temperature variation in Egypt.
The highest recorded temperature was on 30 May 1961, and the coldest recorded temperature was on 31 January 1994.
Due to the constant presence of war in Alexandria in ancient times, very little of the ancient city has survived into the present day. Much of the royal and civic quarters sank beneath the harbour and the rest has been built over in modern times.
"Pompey's Pillar", a Roman triumphal column, is one of the best-known ancient monuments still standing in Alexandria today. It is located on Alexandria's ancient acropolis—a modest hill located adjacent to the city's Arab cemetery—and was originally part of a temple colonnade. Including its pedestal, it is 30 m (99 ft) high; the shaft is of polished red granite, in diameter at the base, tapering to at the top. The shaft is high, and made out of a single piece of granite. Its volume is and weight approximately 396 tons. Pompey's Pillar may have been erected using the same methods that were used to erect the ancient obelisks. The Romans had cranes but they were not strong enough to lift something this heavy. Roger Hopkins and Mark Lehrner conducted several obelisk erecting experiments including a successful attempt to erect a 25-ton obelisk in 1999. This followed two experiments to erect smaller obelisks and two failed attempts to erect a 25-ton obelisk. The structure was plundered and demolished in the 4th century when a bishop decreed that Paganism must be eradicated. "Pompey's Pillar" is a misnomer, as it has nothing to do with Pompey, having been erected in 293 for Diocletian, possibly in memory of the rebellion of Domitius Domitianus. Beneath the acropolis itself are the subterranean remains of the Serapeum, where the mysteries of the god Serapis were enacted, and whose carved wall niches are believed to have provided overflow storage space for the ancient Library. In more recent years, many ancient artifacts have been discovered from the surrounding sea, mostly pieces of old pottery.
Alexandria's catacombs, known as "Kom El Shoqafa", are a short distance southwest of the pillar, consist of a multi-level labyrinth, reached via a large spiral staircase, and featuring dozens of chambers adorned with sculpted pillars, statues, and other syncretic Romano-Egyptian religious symbols, burial niches, and sarcophagi, as well as a large Roman-style banquet room, where memorial meals were conducted by relatives of the deceased. The catacombs were long forgotten by the citizens until they were discovered by accident in 1900.
The most extensive ancient excavation currently being conducted in Alexandria is known as Kom El Deka. It has revealed the ancient city's well-preserved theater, and the remains of its Roman-era baths.
Persistent efforts have been made to explore the antiquities of Alexandria. Encouragement and help have been given by the local Archaeological Society, and by many individuals, notably Greeks proud of a city which is one of the glories of their national history. Excavations were performed in the city by Greeks seeking the tomb of Alexander the Great without success.
The past and present directors of the museum have been enabled from time to time to carry out systematic excavations whenever opportunity is offered; D. G. Hogarth made tentative researches on behalf of the Egypt Exploration Fund and the Society for the Promotion of Hellenic Studies in 1895; and a German expedition worked for two years (1898–1899). But two difficulties face the would-be excavator in Alexandria: lack of space for excavation and the underwater location of some areas of interest.
Since the great and growing modern city stands immediately over the ancient one, it is almost impossible to find any considerable space in which to dig, except at enormous cost. Cleopatra VII's royal quarters were inundated by earthquakes and tsunami, leading to gradual subsidence in the 4th century AD. This underwater section, containing many of the most interesting sections of the Hellenistic city, including the palace quarter, was explored in 1992 and is still being extensively investigated by the French underwater archaeologist Franck Goddio and his team. It raised a noted head of Caesarion. These are being opened up to tourists, to some controversy. The spaces that are most open are the low grounds to northeast and southwest, where it is practically impossible to get below the Roman strata.
The most important results were those achieved by Dr. G. Botti, late director of the museum, in the neighborhood of "Pompey's Pillar", where there is a good deal of open ground. Here, substructures of a large building or group of buildings have been exposed, which are perhaps part of the Serapeum. Nearby, immense catacombs and "columbaria" have been opened which may have been appendages of the temple. These contain one very remarkable vault with curious painted reliefs, now artificially lit and open to visitors.
The objects found in these researches are in the museum, the most notable being a great basalt bull, probably once an object of cult in the Serapeum. Other catacombs and tombs have been opened in Kom El Shoqafa (Roman) and Ras El Tin (painted).
The German excavation team found remains of a Ptolemaic colonnade and streets in the north-east of the city, but little else. Hogarth explored part of an immense brick structure under the mound of Kom El Deka, which may have been part of the Paneum, the Mausolea, or a Roman fortress.
The making of the new foreshore led to the dredging up of remains of the Patriarchal Church; and the foundations of modern buildings are seldom laid without some objects of antiquity being discovered. The wealth underground is doubtlessly immense; but despite all efforts, there is not much for antiquarians to see in Alexandria outside the museum and the neighborhood of "Pompey's Pillar".
The temple was built in the Ptolemy era and dedicated to Osiris, which finished the construction of Alexandria. It is located in Abusir, the western suburb of Alexandria in Borg el Arab city. Only the outer wall and the pylons remain from the temple. There is evidence to prove that sacred animals were worshiped there. Archaeologists found an animal necropolis near the temple. Remains of a Christian church show that the temple was used as a church in later centuries. Also found in the same area are remains of public baths built by the emperor Justinian, a seawall, quays and a bridge. Near the beach side of the area, there are the remains of a tower built by Ptolemy II Philadelphus. The tower was an exact scale replica of the destroyed Alexandrine Pharos Lighthouse.
Among the places of worship, there are Muslim mosques. Coptic Christian churches are most common churches .There are also other Christian churches as: Greek , Latin and Armenian . Orthodox Christian churches are most common but Catholic , Anglican and Evangelical churches are present. Also there is a Jewish synagogue
The most famous mosque in Alexandria is Abu al-Abbas al-Mursi Mosque in Bahary. Other notable mosques in the city include Ali ibn Abi Talib mosque in Somouha, Bilal mosque, al-Gamaa al-Bahari in Mandara, Hatem mosque in Somouha, Hoda el-Islam mosque in Sidi Bishr, al-Mowasah mosque in Hadara, Sharq al-Madina mosque in Miami, al-Shohadaa mosque in Mostafa Kamel, Al Qa'ed Ibrahim Mosque, Yehia mosque in Zizinia, Sidi Gaber mosque in Sidi Gaber, Sidi B esher mosque, Rokay el-Islam mosque in Elessway, Elsadaka Mosque in Sidibesher Qebly, Elshatbi mosque and Sultan mosque.
Alexandria is the base of the Salafi movements in Egypt. Al-Nour Party, which is based in the city and overwhelmingly won most of the Salafi votes in the 2011–12 parliamentary election, supports the president Abdel Fattah el-Sisi.
After Rome and Constantinople, Alexandria was considered the third-most important seat of Christianity in the world. The Pope of Alexandria was second only to the bishop of Rome, the capital of the Roman Empire until 430. The Church of Alexandria had jurisdiction over most of the continent of Africa. After the Council of Chalcedon in AD 451, the Church of Alexandria was split between the Miaphysites and the Melkites. The Miaphysites went on to constitute what is known today as the Coptic Orthodox Church of Alexandria. The Melkites went on to constitute what is known today as the Greek Orthodox Church of Alexandria. In the 19th century, Catholic and Protestant missionaries converted some of the adherents of the Orthodox churches to their respective faiths.
Today, the Patriarchal seat of the Pope of the Coptic Orthodox Church is Saint Mark Cathedral . The most important Coptic Orthodox churches in Alexandria include Pope Cyril I Church in Cleopatra, Saint Georges Church in Sporting, Saint Mark & Pope Peter I Church in Sidi Bishr, Saint Mary Church in Assafra, Saint Mary Church in Gianaclis, Saint Mina Church in Fleming, Saint Mina Church in Mandara and Saint Takla Haymanot's Church in Ibrahimeya.
The most important Eastern Orthodox churches in Alexandria are Agioi Anárgyroi Church, Church of the Annunciation, Saint Anthony Church, Archangels Gabriel & Michael Church, Taxiarchon Church, Saint Catherine Church, Cathedral of the Dormition in Mansheya, Church of the Dormition, Prophet Elijah Church, Saint George Church, Saint Joseph Church in Fleming, Saint Joseph of Arimathea Church, Saint Mark & Saint Nektarios Chapel in Ramleh, Saint Nicholas Church, Saint Paraskevi Church, Saint Sava Cathedral in Ramleh, Saint Theodore Chapel and the Russian church of Saint Alexander Nevsky in Alexandria, which serves the Russian speaking community in the city.
The Apostolic Vicariate of Alexandria in Egypt-Heliopolis-Port Said has jurisdiction over all Latin Church Catholics in Egypt. Member churches include Saint Catherine Church in Mansheya and Church of the Jesuits in Cleopatra. The city is also the nominal see of the Melkite Greek Catholic titular Patriarchate of Alexandria (generally vested in its leading Patriarch of Antioch) and the actual cathedral see of its Patriarchal territory of Egypt, Sudan and South Sudan, which uses the Byzantine Rite, and the nominal see of the Armenian Catholic Eparchy of Alexandria (for all Egypt and Sudan, whose actual cathedral is in Cairo), a suffragan of the Armenian Catholic Patriarch of Cilicia, using the Armenian Rite.
The Saint Mark Church in Shatby, founded as part of Collège Saint Marc, is multi-denominational and holds liturgies according to Latin Catholic, Coptic Catholic and Coptic Orthodox rites.
In antiquity, Alexandria was a major center of the cosmopolitan religious movement called Gnosticism (today mainly remembered as a Christian heresy).
Alexandria's once-flourishing Jewish community declined rapidly following the 1948 Arab–Israeli War, after which negative reactions towards Zionism among Egyptians led to Jewish residents in the city, and elsewhere in Egypt, being perceived as Zionist collaborators. Most Jewish residents of Egypt fled to the newly established Israel, France, Brazil and other countries in the 1950s and 1960s. The community once numbered 50,000 but is now estimated at below 50. The most important synagogue in Alexandria is the Eliyahu Hanavi Synagogue.
Alexandria has a number of higher education institutions. Alexandria University is a public university that follows the Egyptian system of higher education. Many of its faculties are internationally renowned, most notably its Faculty of Medicine & Faculty of Engineering. In addition, the Egypt-Japan University of Science and Technology in New Borg El Arab city is a research university set up in collaboration between the Japanese and Egyptian governments in 2010. The Arab Academy for Science, Technology & Maritime Transport is a semi-private educational institution that offers courses for high school, undergraduate level, and postgraduate students. It is considered the most reputable university in Egypt after the AUC American University in Cairo because of its worldwide recognition from board of engineers at UK & ABET in US. Université Senghor is a private French university that focuses on the teaching of humanities, politics and international relations, which mainly recruits students from the African continent. Other institutions of higher education in Alexandria include Alexandria Institute of Technology (AIT) and Pharos University in Alexandria.
Alexandria has a long history of foreign educational institutions. The first foreign schools date to the early 19th century, when French missionaries began establishing French charitable schools to educate the Egyptians. Today, the most important French schools in Alexandria run by Catholic missionaries include Collège de la Mère de Dieu, Collège Notre Dame de Sion, Collège Saint Marc, Ecoles des Soeurs Franciscaines (four different schools), École Girard, École Saint Gabriel, École Saint-Vincent de Paul, École Saint Joseph, École Sainte Catherine, and Institution Sainte Jeanne-Antide. As a reaction to the establishment of French religious institutions, a secular (laic) mission established Lycée el-Horreya, which initially followed a French system of education, but is currently a public school run by the Egyptian government. The only school in Alexandria that completely follows the French educational system is Lycée Français d'Alexandrie (École Champollion). It is usually frequented by the children of French expatriates and diplomats in Alexandria. The Italian school is the Istituto "Don Bosco".
English schools in Alexandria are becoming the most popular. English-language schools in the city include: Riada American School, Riada Language School, Alexandria Language School, Future Language School, Future International Schools (Future IGCSE, Future American School and Future German school), Alexandria American School, British School of Alexandria, Egyptian American School, Pioneers Language School, Princesses Girls' School, Sidi Gaber Language School, Taymour English School, Sacred Heart Girls' School, Schutz American School, Victoria College, El Manar Language School for Girls (previously called Scottish School for Girls), Kawmeya Language School, El Nasr Boys' School (previously called British Boys' School), and El Nasr Girls' College.
There are only two German schools in Alexandria which are Deutsche Schule der Borromärinnen (DSB of Saint Charles Borromé) and Neue Deutsche Schule Alexandria, which is run by Frau Sally Hammam.
The Montessori educational system was first introduced in Alexandria in 2009 at Alexandria Montessori.
The most notable public schools in Alexandria include El Abbassia High School and Gamal Abdel Nasser High School.
Circa the 1890s, twice the percentage of women in Alexandria knew how to read compared to the same percentage in Cairo. As a result, specialist women's publications like "al-Fatāh" by Hind Nawal, the country's first women's' journal, appeared.
The city's principal airport is currently Borg El Arab Airport, which is located about away from the city center.
From late 2011, El Nouzha Airport (Alexandria International Airport) was to be closed to commercial operations for two years as it underwent expansion, with all airlines operating out of Borg El Arab Airport from then onwards, where a brand new terminal was completed there in February 2010. In 2017, the government announced that Alexandria International Airport will shut down permanently for operational reasons.
Alexandria has four ports; namely the Western Port also known as(Alexandria Port), which is the main port of the country that handles about 60% of the country's exports and imports, Dekhela Port west of the Western Port, the Eastern Port which is a yachting harbor, and Abu Qir Port at the northern east of the governorate. It is a commercial port for general cargo and phosphates.
Alexandria's intracity commuter rail system extends from Misr Station (Alexandria's primary intercity railway station) to Abu Qir, parallel to the tram line. The commuter line's locomotives operate on diesel, as opposed to the overhead-electric tram.
Alexandria plays host to two intercity railway stations: the aforementioned Misr Station (in the older Manshia district in the western part of the city) and Sidi Gaber railway station (in the district of Sidi Gaber in the center of the eastern expansion in which most Alexandrines reside), both of which also serve the commuter rail line. Intercity passenger service is operated by Egyptian National Railways.
An extensive tramway network was built in 1860 and is the oldest in Africa. The network begins at the El Raml district in the west and ends in the Victoria district in the east. Most of the vehicles are blue in color. Some smaller yellow-colored vehicles have further routes beyond the two main endpoints. The tram routes have one of four numbers: 1, 2, 5, and 6. All four start at El Raml, but only two (1 and 2) reach Victoria. There are two converging and diverging points. The first starts at Bolkly (Isis) and ends at San Stefano. The other begins at Sporting and ends at Mostafa Kamel. Route 5 starts at San Stefano and takes the inner route to Bolkly. Route 6 starts at Sidi Gaber El Sheikh in the outer route between Sporting and Mustafa Kamel. Route 1 takes the inner route between San Stefano and Bolkly and the outer route between Sporting and Mustafa Kamel. Route 2 takes the route opposite to Route 1 in both these areas. The tram fares are 50 piastres (0.50 pounds), and 100 piastres (1.00 pounds) for the middle car. Some trams (that date back the 30s) charge a pound. The tram is considered the cheapest method of public transport. A café operates in the second floor of the first car of tram 1 (a women-only car) which costs 5 L.E per person, also offering a WiFi service. A luxury light blue tram car operates from San Stefano to Ras El Tin, with free WiFi and movies and songs played inside for 5 L.E per ticket.
Stations:
Route 2 serves:
Construction of the Alexandria Metro is due to begin in 2020 at a cost of $1.05 billion.
Taxis in Alexandria sport a yellow-and-black livery and are widely available. While Egyptian law requires all cabs to carry meters, these generally do not work and fares must be negotiated with the driver on either departure or arrival.
The minibus share taxi system, or "mashrū'" operates along well-known traffic arteries. The routes can be identified by both their endpoints and the route between them:
The route is generally written in Arabic on the side of the vehicle, although some drivers change their route without changing the paint. Some drivers also drive only a segment of a route rather than the whole path; such drivers generally stop at a point known as a major hub of the transportation system (for example, Victoria) to allow riders to transfer to another car or to another mode of transport.
Fare is generally L.E. 3.00 to travel the whole route. Shorter trips may have a lower fare, depending on the driver and the length of the trip.
The Royal Library of Alexandria, in Alexandria, Egypt, was once the largest library in the world. It is generally thought to have been founded at the beginning of the 3rd century BC, during the reign of Ptolemy II of Egypt. It was likely created after his father had built what would become the first part of the library complex, the temple of the Muses—the Museion, Greek "Μουσείον" (from which the Modern English word "museum" is derived).
It has been reasonably established that the library, or parts of the collection, were destroyed by fire on a number of occasions (library fires were common and replacement of handwritten manuscripts was very difficult, expensive, and time-consuming). To this day the details of the destruction (or destructions) remain a lively source of controversy.
The Bibliotheca Alexandrina was inaugurated in 2002, near the site of the old Library.
Throughout Alexandria, there is art that resembles some of the oldest architectural styles of the Hellenic city, and its ancient decorations, especially in the Bibliotheca Alexandrina, is based on reviving the ancient Library of Alexandria. The Kom el shoqafa Catacombs are considered one of the Seven Wonders of the Middle Ages and date back to the 2nd century. The remnants of Pompey's Pillar still remain today. This single pillar represents the elaborate temple which once stood in Alexandria. It remains at the site of the Serapeum, Alexandria's acropolis. The Serapeum, which stood for ancient tradition, conflicted with the rise of Christianity. It is a large tourist destination, today. the Roman Amphitheatre of Alexandria is another popular destination. Here, there remains a stage with around seven hundred to eight hundred seats. They also have numerous galleries of statues and details leftover form this time. Alexandria's tourism office announced plans to reserve some beaches for tourists in July 2018.
The main sport that interests Alexandrians is football, as is the case in the rest of Egypt and Africa. Alexandria Stadium is a multi-purpose stadium in Alexandria, Egypt. It is currently used mostly for football matches, and was used for the 2006 African Cup of Nations. The stadium is the oldest stadium in Egypt, being built in 1929. The stadium holds 20,000 people. Alexandria was one of three cities that participated in hosting the African Cup of Nations in January 2006, which Egypt won. Sea sports such as surfing, jet-skiing and water polo are practiced on a lower scale. The Skateboarding culture in Egypt started in this city. The city is also home to the Alexandria Sporting Club, which is especially known for its basketball team, which traditionally provides the country's national team with key players. The city hosted the AfroBasket, the continent's most prestigious basketball tournament, on four occasions (1970, 1975, 1983, 2003).
Alexandria has four stadiums:
Other less popular sports like tennis and squash are usually played in private social and sports clubs, like:
Started in 2011, Cross Egypt Challenge is an international cross-country motorcycle and scooter rally conducted throughout the most difficult tracks and roads of Egypt. Alexandria is known as the yearly starting point of Cross Egypt Challenge and a huge celebration is conducted the night before the rally starts after all the international participants arrive to the city.
Alexandria is twinned with: | https://en.wikipedia.org/wiki?curid=3080 |
Alexandria, Louisiana
Alexandria is the ninth-largest city in the state of Louisiana and is the parish seat of Rapides Parish, Louisiana, United States. It lies on the south bank of the Red River in almost the exact geographic center of the state. It is the principal city of the Alexandria metropolitan area (population 153,922) which encompasses all of Rapides and Grant parishes. Its neighboring city is Pineville. In 2010, the population was 47,723, an increase of 3 percent from the 2000 census.
Located along the Red River, the city of Alexandria was originally home to a community which supported activities of the adjacent French trader outpost of "Post du Rapides". The area developed as an assemblage of traders, Caddo people, and merchants in the agricultural lands bordering the mostly unsettled areas to the north and providing a link from the south to the El Camino Real and then larger settlement of Natchitoches, the oldest permanent settlement in the Louisiana Purchase.
Alexander Fulton, a businessman from Washington County, near Pittsburgh, Pennsylvania, received a land grant from Spain in 1762, and the first organized settlement was made at some point in the 1780s. In 1805, Fulton and business partner Thomas Harris Maddox laid out the town plan and named the town in Fulton's honor. The earliest deed that survives for an Alexandria resident is from June 24, 1801, when a William Cochren, who identifies himself as "Slave master of the Southern Americas", sold a tract of land across the Red River to a William Murrey.
That same year, Fulton was appointed coroner in Rapides Parish by territorial Governor William C.C. Claiborne. Alexandria was incorporated as a town in 1819 and received a city charter in 1832.
In the spring of 1863, Alexandria was occupied by Union forces under the command of Admiral David Dixon Porter and General Nathaniel P. Banks. Porter arrived with his gunboats on May 7. Later in the day Banks reached Alexandria with his cavalry, whose members had marched twenty-five miles that day to reach the city. According to the historian John D. Winters of Louisiana Tech University, Porter disliked Banks but nevertheless turned over Alexandria to him and then departed to rejoin General U.S. Grant at the ongoing siege of Vicksburg, Mississippi. Banks posted guards and declared martial law. Porter left behind the gunboat in Alexandria and posted the USS "Pittsburg" on the Black River to the northeast.
In 1864, Admiral Porter returned to the area and quarreled with General Banks over possession of cotton supplies. Porter seized three hundred bales of Confederate cotton from various warehouses in Alexandria and stamped it "U.S.N. prize", referring to the United States Navy. Porter sent his sailors into the country to search for unginned cotton. After the crop was located, it was brought to Alexandria to be ginned and baled. The sailors also seized molasses and wool. Winters writes that Porter "took all cotton wherever he found it, cotton belonging to the Confederate government, cotton belonging to the 'rebels,' and cotton belonging to 'loyal' citizens."
Winters continues: "Banks was furious with Porter when he learned that the admiral was scouring the interior for cotton. Since he had no authority to stop Porter's speculative activities, Banks could only try to beat him to the remaining cotton. Army wagons were sent out in large numbers to collect the cotton. Thousands of bales were brought in by the troops and stored for future shipment. Jealous of the abundant transportation facilities of the army, unprincipled navy men stole army wagons and teams at night, repainted the wagons, and branded the mules with navy initials, and dove deep in the country in search of cotton."
The federal army made itself as comfortable as possible during its long stay in Alexandria. Winters writes that "lumber and tools were foraged, and the men busied themselves by building wooden tent floors, benches, and furniture. ... Alexandria [was enclosed] with a zigzag line of fortifications." While Banks remained in Alexandria in the spring of 1864, Porter was temporarily trapped north of the city because of the low level of the Red River, four feet instead of the needed seven feet to accommodate gunboats.
Confederate citizens as a whole were most fearful of the Union. According to Winters, "most [Confederates] had never before seen a Yankee soldier [and] expected the worse from the invader. ... 'Some cried, some cursed, some whined; and some overcome with fear, hid themselves in the woods, leaving everything to the tender mercies of the army.' Negroes were responsible for much of the plunder and pillage. Negro camp followers and officers' servants roamed the plantations and small farms without hindrance, bringing in their booty to camps each afternoon."
On May 13, 1864, when the Union decided to abandon Alexandria, the city was set afire despite General Banks' order to the contrary. Winters reports that "burning and plundering" by two Union corps, who set fire to a store on Front Street. Then "a strong wind spread the flames rapidly from one building to the next." Banks later claimed that the fire "broke out in the attic of one of the buildings on the levee inhabited by either soldiers or refugees." Winters reports that "pandemonium reigned; frightened cows bellowed and charged through the flaming streets; squawking chickens with scorched wings tried to fly out of danger. Hundreds of women, children, and old people ran through the streets, trying to carry a few of their belongings to safety. When the heat became unbearable, they dropped their loads and fled to the levee. Thieves ran from house to house and even along the levee taking whatever they wanted from the shocked people. By noon the most congested parts of town were destroyed. An attempt to blow up a church in the path of the fire only succeeded in helping to spread the flames."
Alexandria faced the overwhelming task of rebuilding with a year of the war remaining. Prices became exorbitant; butter cost $10 a pound, bacon $5 a pound, flour $3 a pound, and a bushel of meal $10. Many of the helpless lived in the forest without food, shelter, or clothing, subsisting on blackberries. All clothing was homespun, and shoes were mostly made of cloth. While Admiral Porter expressed sympathy for the suffering Alexandria residents, he declared the "burning of Alexandria a fit termination of the unfortunate Red River expedition."
Alexandria is located at and has an elevation of .
According to the United States Census Bureau, the city has a total area of , of which 26.4 square miles (68.4 km2) is land and 0.6 square mile (1.5 km2) (2.15%) is water.
Alexandria is on a level plain in the center of the Louisiana Longleaf Pine forests, in which pine is interspersed with various hardwoods. A number of small bayous, such as Bayou Rapides, Bayou Robert, and Hynson Bayou, meander throughout the city. In the immediate vicinity of the city, cotton, sugar, alfalfa, and garden vegetables are cultivated.
The climate is humid subtropical with some continental influence in the winter. Summers are consistently hot and humid, whereas winters are mild, with occasional cold snaps. On average, the first freeze occurs in early to mid November and the last freeze occurs in early to mid March. The area receives plentiful rainfall year-round, with thunderstorms possible throughout the year. Some storms can be severe, especially during the spring months. According to 'Cities Ranked and Rated' (Bert Sperling and Peter Sander), Alexandria reports an average of 69 days per year with thunder reported, which is nearly double the national average. Snowfall is rare, with measurable snow having occurred 27 times since 1895. The heaviest snowfall event took place February 12–13, 1960 when 9.1" of snow fell.
Tropical storms and hurricanes affect Alexandria from time to time, but rarely cause severe damage, unlike areas closer to the coast. In September 2005 Hurricane Rita moved inland and affected Alexandria and surrounding areas, causing widespread power outages and damaging the roofs of some structures. The most recent hurricane, Gustav in 2008, caused widespread flooding, knocked over trees and power lines leading to power outages, and damaged structures. Some low-lying Alexandria neighborhoods had substantial flooding from Gustav, leaving several feet of water in houses.
As of the census of 2010, there were 47,723 people, 17,816 households, and 11,722 families residing in the city. The population density was 1,754.6/sq mi (677.5/km2). There were 19,806 housing units at an average density of 749.9 per square mile (289.6/km2). The racial makeup of the city was 38.32% White, 57.25% Black, 1.25% Native American, 1.85% Asian, 0.14% Pacific Islander, 1.03% from other races, and 1.09% from two or more races. 6.98% of the population were Hispanic or Latino of any race.
There were 17,816 households, out of which 31.9% had children under the age of 18 living with them, 38.5% were married couples living together, 23.2% had a female householder with no husband present, and 34.2% were non-families. 30.4% of all households were made up of individuals, and 12.1% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.13.
In the city, the population was spread out, with 28.1% under the age of 18, 9.2% from 18 to 24, 26.2% from 25 to 44, 21.4% from 45 to 64, and 15.1% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 83.5 males. For every 100 females age 18 and over, there were 77.7 males.
The median income for a household in the city was $26,097, and the median income for a family was $31,978. Males had a median income of $29,456 versus $20,154 for females. The per capita income for the city was $16,242. About 23.2% of families and 27.4% of the population were below the poverty line, including 37.7% of those under age 18 and 18.5% of those age 65 or over.
Like many other southern cities, the largest single church denomination in the Alexandria area is Southern Baptist. Large congregations include Emmanuel Baptist Church downtown on Jackson Street and Calvary Baptist off Jackson Street Extension. Alexandria is also headquarters of the Louisiana Baptist Convention. A significant Roman Catholic population is also present, a result of the large Catholic Acadian French population which resides in and around Alexandria, many from neighboring Avoyelles Parish. Alexandria is the headquarters for the Diocese of Alexandria, Louisiana, which is headed by Bishop David Talley.
Alexandria also has a significant number of Methodists, Presbyterians, and Episcopalians. There is a large number of Pentecostals too. Alexandria has a small, though active Jewish community which dates back to the mid-19th century. Jews have consistently been leaders in government, civic organizations, education, and medicine. The long-time Alexandria City Council member, Harry B. Silver, is Jewish. From 1973 to 1977, another Jew, Arnold Jack Rosenthal, was the last commissioner of finance and utilities under the previous commission form of municipal government. At one time, many large businesses in the downtown were Jewish-owned, with prominent stores including: Wellan's, Caplan's, Bialy's, Weiss & Goldring and Schwartzberg's. The Jewish community in Alexandria maintains two synagogues, which are approximately two blocks apart: Congregation Gemiluth Chassodim (Reform) and B'nai Israel Traditional Synagogue (Conservative).
As Alexandria is at the cusp of Cajun culture's extension to the north, the city recognizes Mardi Gras as an official holiday. The annual Mardi Gras Krewes Parade – occurring on the Sunday before Mardi Gras – on Texas Avenue is a major cultural festivity in the area. It is featured as a family-oriented event, and parade goers can enjoy over 20 New Orleans style floats, high school and college marching bands, as well as appearances by local celebrities. In addition to the main Sunday parade, the College Cheerleaders & Classic Cars Parade, which was established in 2008, takes place downtown on the Friday before Mardi Gras, the Children's Parade takes place downtown on the Saturday before Mardi Gras, and the Krewe of Provine Parade is held on Fat Tuesday, processing along Coliseum Boulevard. All the events are organized by the Alexandria Mardi Gras Association (AMGA). The Krewe Parade can attract from 120,000 to 150,000; the Children's parade, up to 40,000 to 50,000, and the College Cheerleaders & Classic Cars, about 5,000 to 15,000 people.
An annual three-day festival is held in downtown Alexandria around late April and early May. The festival, established in 2013, was created around a former successful stand-alone event, the Louisiana Dragon Boat Races. It features the race and other former stand-alone events such as Dinner on the Bricks and the ArtWalk (now Art Fête) along with various booth venues, food, and live music, as well as the Kids Fête and Classic Car Fête.
An annual three day festival held in downtown Alexandria around early December. Launched in 2015, the festival first year drew about double the anticipated crowd of 15,000. The festival, like the Alex River Fête, feature booth venues, food, and live music but also features an ice rink. In January 2017, the Alex Winter Fête was voted Festival of the Year by the Louisiana Travel Promotion Association.
Begun in the late 1980s, Cenlabration
was one of the largest festivals in Central Louisiana (Cenla). The name comes from Central Louisiana ("LA") Celebration, and reflects local culture and heritage, as well as serving as a means of celebrating Labor Day as the end of summer.
As many as three stages support a particular type of music, including Cajun and zydeco, blues and jazz, and Country music. In addition there are arts and crafts booths for local artists to sell their wares. In the Children's Village, children can participate in arts and crafts, listen to storytellers, play games with clowns, or watch a play. The festival has plenty of carnival rides available as well. Cenlabration ends with a large fireworks display.
The festival ran for 20 years until cancellation due to finances. The city ended its annual support of $40,000 because of budget constraints.
In 2002, representatives of local government, businesses, organizations, and community formed the nonprofit organization River Cities Cultural Alliance, Inc. to promote tourism and the arts through a celebration of Central Louisiana's diverse cultural heritage. The nonprofit served to organize and put on RiverFest: Heritage and Arts on the Red. More than ten thousand festival-goers attending the event.
RiverFest was held in downtown Alexandria and on the Alexandria and Pineville levees. The festival features the work of visual artists from across the South, food booths exemplifying southern cuisine, a variety of children's activities, three outdoor stages with a wide range of music, dance, and theatrical performances, and a literary component with readings and panel discussions by Louisiana authors and scholars.
RiverFest was canceled in 2007.
An annual barbecue festival launched in 2006, the festival was held on the levee near downtown Alexandria and was well known for its big-name entertainment. The event was cancelled in 2012 due to its high cost and the city deciding against continued support of $100,000 annually.
The Alexandria Museum of Art was founded in 1977 and occupies an historic Rapides Bank Building on the banks of the Red River. The building was built c. 1898 and is listed on the National Register of Historic Places. The museum opened to the public in March 1998. In 1998, the Alexandria Museum of Art expanded and constructed its grand foyer and offices as an annex to the Rapides Bank Building. In 1999, the Alexandria Museum of Art was honored as an Outstanding Arts Organization in the Louisiana Governor's Arts Awards. In 2007, the Alexandria Museum of Art entered into a collaborative endeavor agreement with Louisiana State University of Alexandria (LSUA). The Alexandria Museum of Art now also serves as a downtown campus for LSUA classes, and is host to multidisciplinary community events, including concerts and recitals, lectures, yoga classes, Second Saturday Markets, and Museum Afterhours.
The Louisiana History Museum is located downtown on the bottom floor of the former library. A small facility, it showcases the history of all Louisiana, with emphasis on the central portion of the state, Rapides Parish, and Alexandria. Major exhibit areas concern Native Americans, Louisiana geography, politics, health care, farming, and the impact of war.
The T.R.E.E. House Children's Museum and Arna Bontemps African American Museum are located within the Cultural Arts District.
The Kent Plantation House in Alexandria, completed by 1800, was located on a Spanish land grant. It is the oldest standing structure in Central Louisiana, one of only two buildings in the city to survive the burning of 1864 by Union troops fleeing after having been defeated at the Battle of Mansfield in DeSoto Parish. The house has been moved from its original location but is still located on part of the first land grant. It is open for tours daily except Sundays at 9, 10, and 11 a.m. and 1, 2, and 3 p.m. The tour is led by costumed docents and includes the house furnished in period pieces, some belonging to the original family, and all nine outbuildings, including an 1840-50s sugar mill, blacksmith shop, barn, two slave cabins, open-hearth kitchen, and milk house.
The performing arts are centered in the Alexandria Cultural Arts District in the downtown. Located within a few blocks of each other are three performance venues: Coughlin-Saunders Performing Arts Center, the Hearn Stage, and the Riverfront Amphitheater.
The Coughlin-Saunders Performing Arts Center is the home of the Rapides Symphony Orchestra, which has performed in Alexandria since 1968. The center hosts the Performing Arts Series of the Arts Council of Central Louisiana, the Red River Chorale (an auditioned community chorus), and presentations of numerous local theater groups. The land for the center was donated by "The Alexandria Town Talk" newspaper, owned by the Gannett Company of McLean, Virginia.
Businesswoman Jacqueline Seagall Caplan (1935–2016) was the president of the Arts Council of Central Louisiana and the chairman of the group's executive committee when the Coughlin-Saunders Performing Arts Center opened in 2004. She predicted that Coughlin-Saunders would in time "provide a place people can point to and say it's theirs. ... [Until now], we've never had a performing arts center where every type of performing art can come."
The Hearn Stage is a black box theater for smaller productions. The Arts Council provides day-to-day management of both the Coughlin-Saunders Center and the Hearn Stage.
The Riverfront Amphitheater hosts each April a "Jazz on the River" music festival, sponsored by the Arna Bontemps African American Museum. The Rapides Symphony holds an annual fall Pops concert in the amphitheater. In recent years, the amphitheater has welcomed musical guests in conjunction with the springtime Dragonboat Races sponsored by the Alexandria Museum of Art.
The spring and fall seasons also feature Downtown Rocks, a free outdoor concert series in nearby Fulton Park.
Alexandria was home to the Alexandria Aces, a summer college league team. The Aces were champions in various leagues in 1997, 1998, 2006, and 2007. They played their home games at Bringhurst Field. The remaining games of the 2013 season were cancelled in mid-July because of low attendance, which averaged fewer than two hundred per game. In 1974, a Little League team from Alexandria won the Louisiana state championship.
Alexandria had a minor league ice hockey team, the Alexandria Warthogs. They played their home games at the Rapides Parish Coliseum.
A professional indoor football team, the Louisiana Rangers, played their home games at the Rapides Parish Coliseum. They played in the Central District of the Southern American Football League, and the Southern Conference of the National Indoor Football League (NIFL). The team was owned by a Lafayette business group before moving in 2003 to Beaumont, Texas.
Alexandria is also home to the U-14 Crossroads Pride soccer team. They won the 2012 Louisiana Soccer Association State Cup. The Pool Boys FC soccer team, a member of the Gulf Coast Premier League, plays at Johnny Downs Sports Complex.
Nearby is Bringhurst Golf Course, popularly known as "the nation's oldest par three course." A full-scale renovation was completed in mid-2010. In addition to Bringhurst, named for the late industrialist R.W. Bringhurst, Alexandria is home to four other golf courses: Oak Wing, The Links on the Bayou, at LSUA, and Alexandria Golf and Country Club.
Alexandria was also home to the Cenla Derby Dames, a roller derby team that operates under the Women's Flat Track Derby Association. The Dames played their home games at the Rapides Parish Coliseum.
Established March 17, 1883, The Alexandria Town Talk is a daily newspaper for Alexandria-Pineville and the thirteen parishes which comprise central Louisiana. The newspaper was owned by the family of the late Jane Wilson Smith and Joe D. Smith, Jr., until March 1996, when it was sold to Central Newspapers. In August 2000, the Gannett Company acquired the Central Newspapers properties, including "The Town Talk". The name of the paper on its inaugural issue was the "Alexandria Daily Town Talk". Although it has since been shorted to the current "The Town Talk", it is still frequently referred to by long-time residents as the "Daily Town Talk".
Alexandria is served by local television stations KALB-TV (NBC / CBS), WNTZ (Fox), KLAX-TV (ABC), KLPA (PBS/LPB), and KBCA (The CW). KALB is the oldest television station in central Louisiana.
Alexandria is the location of the pawn shop in the show Cajun Pawn Stars on the History Channel.
Local radio stations
The Alexandria Zoological Park is a zoo first opened to the public in 1926. Owned by the City of Alexandria and operated by the Division of Public Works, it is home to about 500 animals and includes an award-winning Louisiana Habitat exhibit. Much of the credit for the quality of the zoo has been given to Robert Leslie Whitt (1951–2008), who served as director for 34 years prior to his death. Whitt was hired in 1974 by then Streets and Parks Commissioner Malcolm Hebert. The zoo is accredited by the Association of Zoos and Aquariums (AZA) and takes part in about 20 Species Survival Plans (SSP) as part of its conservation efforts.
Cotile Lake is a man-made impoundment located in the uplands approximately west-northwest of Alexandria, Louisiana. The lake is approximately in size and was completed in October 1965. The Louisiana Wild Life and Fisheries Commission stocked this impoundment with the proper species and number of game fish in 1965–66 shortly after its completion date. The recreational facilities include a large area cleared and zoned for swimming with complete bath house facilities nearby. There is a water skiing area that is cleared and snagged for safety of the skiers. The picnic and camping areas are modern and complete. There is also space available for campers.
Encompasses a lake, of developed recreation facilities and a primitive camping area all within the Alexander State Forest. The lake, located in central Louisiana, was constructed as a joint venture of the Louisiana Forestry Commission, the Rapides Parish Police Jury, and the Lower West Red River Soil and Water Conservation District as a reservoir for agricultural irrigation in times of need and for recreation purposes.
The recreation area camping area contains 109 campsites with conventional full utility hookups, 3 beaches for swimming, bath houses, a boat launch, and 75 picnic sites. A covered pavilion within the developed area provides for groups up to 100 people. The recreation area is open year-round and operates on user fees.
Alexandria sits in the middle of the Kisatchie National Forest. Ranger districts are north, northwest, west and southwest of the city. An abundance of large timberlands and forest nurseries, as well as lake and recreation areas, are within a short driving distance.
Alexandria is home to both Headquarters and Company B of the 199th Brigade Support Battalion (BSB). The 199th BSB is the logistical component of the 256th Infantry Brigade that served in Operation Iraqi Freedom from October 2004 until September 2005. The 199th BSB provides supply and transportation (Company A), medical (Company C) and maintenance (Company B) support and services that keep the 256th Brigade operational. The battalion also has units located in Jonesboro, Winnfield, Colfax, and St. Martinville, Louisiana.
Alexandria served as the home of England Air Force Base from its origins as an emergency airstrip for Esler Regional Airport until its closure. England AFB was officially closed on December 15, 1992, pursuant to the Defense Base Closure and Realignment Act (Public Law 101-510) and recommendations of the Defense Secretary's Commission on Base Realignment and Closure. The base now serves as Alexandria International Airport (see below).
According to Census ACS 1-year survey for 2016, the per capita income of Alexandria was $23,962. This is $1,702 lower than the Louisiana average for per capita income in the same period. That figure is at $31,128 nationally. The Alexandria workforce consists of about 55,000 residents. Union Tank Car Company has recently located a plant northwest of Alexandria near the airport creating hundreds of jobs. Expansions at the Procter & Gamble plant and the construction of a PlastiPak plant in nearby Pineville have also created a number of new jobs for the area. Sundrop Fuels Inc., a Colorado-based biofuels start-up, plans to construct an over 1,200 acre plant just southwest of Alexandria in Rapides Station area. The facility will serve as the headquarters for the company because aside from the plant itself, Sundrop has also bought Cowboy Town, an abandon entertainment venue that sits inside the surrounding land that was purchased, to house their offices and their maintenance and fabrication operations.
In 2007, Inc. Magazine rated Alexandria as the 77th best place in which to conduct business out of the 393 U.S. cities ranked, a significant increase from its ranking as No. 276 in 2006. Among other Louisiana cities, Alexandria ranked second, following only Baton Rouge, which ranked 59th nationally.
Alexandria is home to two major hospitals: Rapides Regional Medical Center, a former Baptist hospital is located downtown. Christus St. Frances Cabrini Hospital was opened in 1950 and is located at the corner of Masonic Drive and Texas Avenue. Both hospitals have undergone expansion.
Additionally, located just across the Red River in Pineville, the Veteran's Affairs Medical Center at Alexandria serves central Louisiana and surrounding areas.
Meanwhile, in 2013, the state allocated $15 million to move the medical services long provided at no or minimal charge at the Huey P. Long Medical Center in Pineville to the former hospital at England Park at the site of the closed England Air Force Base.
In the early 19th century, the Port of Alexandria brought goods to the area and shipped cotton and other local products to the rest of the country. A ferry connected the cities of Alexandria and Pineville until a bridge was built across the Red in 1900.
Today, Port facilities include: a 40-ton crane for off-loading, a warehouse, 13,600-ton bulk fertilizer warehouse, a 3,400-ton bulk fertilizer dome structure and a 5,000-ton dome which was added in January 2005.
The petroleum off-loading facility includes two tanks, one tank capable of handling two barges and five truck off-loading simultaneously. There is also a general cargo dock with access to rail and a hopper barge unloading dock with conveyor system.
Today's modern facilities and the Port's central location with its connection to the Mississippi River provide excellent opportunities for importers and exporters.
Alexandria International Airport (AEX) is a regional airport, providing flights to Atlanta, Dallas/Ft. Worth, and Houston. In 2006 a new-state-of-the-art passenger terminal was dedicated. Alexandria is served by American, United, and Delta.
Formerly known as England AFB until 1992, Alexandria International Airport additionally has numerous international charter airlines use the airport in the transport of military personnel attached to the United States Army base at Fort Polk. A new military personnel terminal opened in 2007.
Downtown Alexandria, including the Alexandria Cultural Arts District, is currently in the process of revitalization. It is home to five museums, three performance venues, and several galleries. In recent years, several bars, cafes, and restaurants have opened.
Across the street from the venues is the Hotel Bentley. The Bentley was built in 1908 by lumberman and local eccentric Joseph A. Bentley. The Bentley's heyday was during the 1940s and 1950s, when senior military officials, including General Dwight D. Eisenhower, stayed for extended periods. The Bentley, which was closed on December 12, 2004, was once one of only two four-star hotels in Louisiana. The hotel was set to reopen in August 2007, in time for the 100th anniversary of its construction, but was prevented by funding issues. The current owner, Michael Jenkins, purchased the Bentley for $3.4 million. His plan is to keep the older portion of the building to remain a hotel and turn the 7-story tower portion into luxury condominiums, and also to reopen Bentley's restaurant and Mirror Room lounge. The hotel and all of its components were to have been opened by the summer of 2013, but the hotel remained unfinished as of November 2014.
Central Alexandria is bounded by MacArthur Drive, Masonic Drive, Mason Street, the Alexandria-Pineville Expressway, and the Red River.
Northwestern Alexandria comprises the area north of Louisiana Highway 28 West and MacArthur Drive and south of the Red River.
Western Alexandria is the area south of Highway 28 West, west of MacArthur Drive, and north of Versailles Boulevard and Metro Drive
Alexandria real estate broker Robert Andrew Wolf, Jr. (1930–2016), designed The Centre and other local and regional developments, including the Walmart SuperCenter on Louisiana Highway 28 West, the Melrose Plantation in Natchitoches Parish with partner John Wasson, at which once lived the author Francois Mignon and the painter Clementine Hunter, and the site of what became the Union Tank Car Company near England Airpark, formerly part of England Air Force Base. In 1967, he and Wasson designed the Wedgewood subdivision in Alexandria; in 1970, they sold Melrose. Wolf was a past president of the Alexandria-Pineville Board of Realtors and in 1984 was named "Realtor of the Year".
Southwestern Alexandria comprises the area west of Masonic Drive and south of Versailles Boulevard and Metro Drive.
Southern Alexandria is located east of Masonic Drive and south of MacArthur Drive
Southeastern Alexandria contains the area northeast of MacArthur Drive, south of Masonic Drive, Mason Street, and Alexandria-Pineville Expressway, and bordered by the Red River.
Rapides Parish
Grant Parish
Following the Civil War, all public records in Alexandria had been destroyed. On September 29, 1868, the city was granted a new charter with a government consisting of a Mayor, Treasurer, and Justice of the Peace. Nine aldermen represented the four wards of the city – two from each ward and one elected at-large.
In 1912, the Lawrason Act established Alexandria municipal government in a strong mayor format, where the mayor was also the Commissioner of Public Health and Safety (Police, Fire, Sanitation). There were separate Commissioners of Streets and Parks and Finance and Utilities, elected citywide. The last to hold those positions, which ended in 1977, were Mayor John K. Snyder (1922–1993), Malcolm P. Hebert, Sr. (1926–2006), and Arnold Jack Rosenthal (1923–2010), respectively.
Alexandria has a mayoral-council system of government. The Mayor serves as the executive branch of the local government. The current Mayor – Jacques Roy – was elected to office in November 2006, succeeding long-time mayor Edward Gordon "Ned" Randolph, Jr. Randolph had succeeded John K. Snyder.
The City Council serves as the legislative branch. The five districts of the city are represented on the Council; in addition there are two council members elected to serve as at-large representatives of the city.
The Alexandria Court has a limited jurisdiction, consisting of the citizens of Wards 1, 2 and 8 in Rapides Parish. Within those boundaries the court has the power to hear and decide both criminal and civil cases, rule in civil cases and hand down judgment for punishment in criminal cases.
Overall, the people of the Alexandria area tend to be conservative. Even though the majority typically elects Republicans in national elections, they vote for Democrats in local elections, many of which are not contested by the GOP.
From 1913 to 1993, Alexandria served as the seat of Louisiana's Eighth Congressional district. A Democratic seat, it was held by the Long family for nearly half of its existence, from 1953 to 1987, broken only by the two terms of Harold B. McSween and three terms of Republican Clyde Holloway of Forest Hill. The seat was removed after the 1990 census indicated Louisiana no longer had the population to support it. The district was split among the Fourth, Fifth and Sixth Congressional districts. Alexandria is now in the Fifth district and was represented from 2003 to 2013 by Rodney Alexander, a Democrat-turned-Republican. From November 2013 to January 2015 the representative is Vance McAllister of Ouachita Parish.
Situated south of the city, Louisiana State University at Alexandria (or LSUA) is a regional campus of the state's flagship university system, Louisiana State University. From its establishment in 1959, the campus offered only two-year degrees; students seeking baccalaureate degrees had to commute or move to the main campus in Baton Rouge in order to gain a four-year degree. After 1976, students could either commute or telecommute in order to attend upper-level courses, including graduate classes. In 2002, following approval by the Louisiana State University Board of Supervisors and the Louisiana Board of Regents the Louisiana Legislature passed legislation allowing LSUA to offer baccalaureate degrees.
A four-year degree is also attainable through Southern Baptist-affiliated Louisiana College in Pineville, founded in 1906.
Alexandria also has one of the Region 6 Louisiana Technical College campuses.
Rapides Parish School Board operates public schools.
Alexandria has three public high schools: Bolton High School, Alexandria Senior High School, and Peabody Magnet High School. In addition, there are two private high schools: the Roman Catholic Holy Savior Menard Central High School, and Grace Christian.
The Renaissance Home for Youth west of Alexandria is a haven for youthful offenders who live in a group-home setting as an alternative to reform school or adult jail. Since the facility opened in 1973, nearly 12 thousand young people have lived at the home in search of rehabilitation.
Alfred Booker Junior Academy proudly follows faith- centered education for all students Pre-Kindergarten through eighth grade.
Alexandria serves as the crossroads of Louisiana. To reach either Shreveport or Monroe from the southern portion of the state, the easiest method of travel takes the driver through Alexandria. Likewise, if a visitor is to head from the northern portion of the state to the Cajun portions of the state (Lake Charles and Lafayette), or the greater metropolitan areas of either Baton Rouge or New Orleans, the easiest method of travel involves driving down Interstate 49 through Alexandria.
In addition to I-49, travelers can follow Louisiana 1 up to Alexandria from Baton Rouge and points south. Also, Highway 167 could be taken from Opelousas north to Ruston, crossing through Alexandria at one of the few bridges over the Red River in central Louisiana. Highways 165 and 71 also link Alexandria and points south with the northern and southern portions of the state via the Curtis-Coleman bridge.
There are possible plans for a 50-mile, 4 lane beltway to encircle Alexandria and Pineville. As of now, it is only in the planning stages of development.
Three road bridges cross the Red River in the Alexandria area. They are:
Former bridges include:
There are two railroad bridges over the Red River in Alexandria. One is located near the Buhlow area north of the OK Allen bridge. The other is south of the Purple Heart Memorial Bridge.
Regional mass transit is handled by ATRANS (Alexandria Transportation Authority).
For those leaving or arriving at the city by bus, Greyhound Lines has a terminal downtown.
Alexandria is served by the Alexandria International Airport and the Esler Regional Airport in Pineville.
Alexandria does not have Amtrak service, nor a commuter rail system. The Kansas City Southern ("Southern Belle") and the Missouri Pacific (since absorbed by Union Pacific) ("Louisiana Eagle" and "Louisiana Daylight") operated train stations in the area in the early part of the 20th century but passenger services ended in the 1960s and the stations have closed. | https://en.wikipedia.org/wiki?curid=3083 |
Alexandria Troas
Alexandria Troas ("Alexandria of the Troad"; ; ) is the site of an ancient Greek city situated on the Aegean Sea near the northern tip of Turkey's western coast, a little south of Tenedos (modern Bozcaada). It is located southeast of modern Dalyan, a village in the Ezine district of Çanakkale Province. The site sprawls over an estimated ; among the few structures remaining today are a ruined bath, an odeon, a theatre, gymnasium complex and a recently uncovered stadion. The circuit of the old walls can still be traced.
According to Strabo, this site was first called Sigeia (Σιγία); around 306 BC Antigonus refounded the city as the much-expanded Antigonia Troas by settling the people of five other towns in Sigeia, including the once influential city of Neandreia. It did not receive its name until its name was changed by Lysimachus to Alexandria Troas, in 301 BC, in memory of Alexander III of Macedon (Pliny merely states, in his view, that the name changed from Antigonia to Alexandria). However, Pliny's view is not correct, because the city continued being called Alexandria Troas, and so is also stated in the 4th-5th c. AD Tabula Peutingeriana. As the chief port of north-west Asia Minor, the place prospered greatly in Roman times, becoming a "free and autonomous city" as early as 188 BC, and the existing remains sufficiently attest its former importance. In its heyday the city may have had a population of about 100,000. Strabo mentions that a Roman colony was created at the location in the reign of Augustus, named Colonia Alexandria Augusta Troas (called simply Troas during this period). Augustus, Hadrian and the rich grammarian Herodes Atticus contributed greatly to its embellishment; the aqueduct still preserved is due to the latter. Constantine considered making Troas the capital of the Roman Empire.
In Roman times, it was a significant port for travelling between Anatolia and Europe. According to the account in the Acts of the Apostles, Paul of Tarsus sailed for Europe for the first time from Alexandria Troas and returned there from Europe (it was there that the episode of the raising of Eutychus is said to have occurred). Ignatius of Antioch also paused at this city before continuing to his martyrdom at Rome.
Several of its later bishops are known: Marinus in 325; Niconius in 344; Sylvanus at the beginning of the 5th century; Pionius in 451; Leo in 787; Peter, friend of the Patriarch Ignatius, and adversary to Michael, in the ninth century. In the 10th century Troas is given as a suffragan of Cyzicus and distinct from the famous Troy (Heinrich Gelzer, "Ungedruckte ... Texte der Notitiae episcopatuum", 552; "Georgii Cyprii descriptio orbis romani", 64); it is not known when the city was destroyed and the diocese disappeared. The bishopric remains a titular see of the Catholic Church under the name Troas, vacant since 1971.
Troas is also a titular see of the Orthodox Church under the Ecumenical Patriarchate. Bishop Savas (Zembillas) of Troas served as hierarch from 2002 to 2011, and then became Metropolitan Savas (Zembillas) of Pittsburgh in the Greek Orthodox Archdiocese of America.
Karasid Turkomans settled in the area of the Troad in the 14th century. Their "beylik" was conquered by the Ottomans in 1336. The ruins of Alexandria Troas came to be known among the Turks as "Eski Stambul", the "Old City". The site's stones were much plundered for building material (for example Mehmed IV took columns to adorn his Yeni Valide Mosque in Istanbul). As of the mid-18th century the site served as "a lurking place for bandetti".
By 1911, the site had been overgrown with Vallonea oaks and much plundered, but the circuit of the old walls could still be traced, and in several places they were fairly well preserved.
They had a circumference of about ten kilometres, and were fortified with towers at regular intervals.
Remains of an ancient bath and gymnasium complex can be found within this area; this building is locally known as "Bal Saray" (Honey Palace) and was originally endowed by Herodes Atticus in the year 135. Trajan built an aqueduct which can still be traced.
The harbour had two large basins, now almost choked with sand.
It is the subject of an early twenty-first century study by German archaeologists digging and surveying at the site.
Their excavation uncovered the remains of a large stadium dating to about 100 BC. | https://en.wikipedia.org/wiki?curid=3085 |
Alexandria, West Dunbartonshire
Alexandria (, ) is a town in West Dunbartonshire, Scotland. The town is on the River Leven, north of Dumbarton and north-west of Glasgow.
In 2001, the population of the town was 13,444. It is the largest town in the Vale of Leven, the others being Balloch, Bonhill, Jamestown and Renton; their combined population is over 20,000.
The town's traditional industries, most importantly cotton manufacturing, bleaching and printing, have been phased out. In the 1970s Alexandria was redeveloped, with a new town centre layout and traffic system. Local landmarks include Christie Park and the Category B listed Smollett Fountain in the town centre. Lomond Galleries on North Main Street is a former car factory with an impressive dome and an even more impressive marble entrance hall and staircase. It was originally built in 1906 as the Argyll Motor Works, for Argyll Motors Ltd. A carving above the entrance shows one of the company's cars. After the car production ceased in 1914, it was used by the Admiralty for the manufacture of torpedoes, which were test-fired in Loch Long, and in the early 1970s was the scene of the Plessey sit-in. The building now hosts a shopping mall but has retained many of its striking architectural features.
Major employers in the area were Westclox and Polaroid, both based in the Leven Industrial Estate; Aggreko based a major purpose-built factory in the estate from 2000–2010. The Ballantine's whisky distillery continues to operate in the estate.
Alexandria sits on the former A82 main road between Glasgow and Loch Lomond. There are regular bus services on the route, and the town has a railway station on the rail line between Balloch and Glasgow Queen Street.
Alexandria is reputed to be the only town in the UK with a railway station, carnival (periodically Codonnaz travelling fayre sets up in the car park) and a pub in the middle of a roundabout. A. J. Cronin's uncle owned a pub in Bridge Street. Alexandria Library is located on Gilmour Street.
The town is home to Vale of Leven football club, who play at Millburn Park. The club was a dominant force in early Scottish football history, winning the Scottish Cup in 1877, 1878 and 1879, and were founder members of the Scottish Football League.
Gordon Reid, born in Alexandria, has won the Wimbledon Tennis Men's Wheelchair Doubles, with his partner Alfie Hewett, three times. | https://en.wikipedia.org/wiki?curid=3087 |
Angela Vincent
Angela Vincent (born 1942) is emeritus professor at the University of Oxford and a Fellow of Somerville College, Oxford.
Angela was Head of the Department of Clinical Neurology (2005-2008) at the University of Oxford, President of the International Society of Neuroimmunology, and an Associate Editor of Brain (2004-2013). Her research group was located in the Weatherall Institute of Molecular Medicine at the John Radcliffe Hospital, working on a wide range of biological disciplines encompassing molecular biology, biochemistry, cellular immunology and intracellular neurophysiology. The group's research focused on autoimmune and genetic disorders of the neuromuscular junction, peripheral nerves and more recently the exciting field of central nervous system diseases. The principal autoimmune diseases studied were myasthenia gravis, the Lambert-Eaton myasthenic syndrome, limbic encephalitis, other types of autoimmune encephalitis and acquired neuromyotonia. Since 2016 she has been Emeritus Professor at Oxford University and she continues to advise and support young researchers. Her group's work is continued under Associate Professor Sarosh Irani and Dr Patrick Waters.
Her contributions have been mainly on the roles of antibodies directed against ion channels, proteins complexed to ion channels, such as LGI1, CASPR2 and Contactin-2, within neurons, glia and the nerve-muscle junction in the pathogenesis of above-mentioned diseases.
She has demonstrated that transfer of these antibodies across the placenta from the pregnant woman to the fetus in utero can cause developmental abnormalities.
In 2009 she presented the Leslie Oliver Oration at Queen's Hospital. In 2009 she received the medal of the Association of British Neurologists and in 2017 the World Federation of Neurology Scientific Contributions to Neurology award. She was awarded the Klaus Joachim Zülch Prize with J Posner and J Dalmau in 2018. In 2003, she was elected a Fellow of the Academy of Medical Sciences (FMedSci) and in 2011 Fellow of the Royal Society (FRS). | https://en.wikipedia.org/wiki?curid=3089 |
Arithmetic–geometric mean
In mathematics, the arithmetic–geometric mean (AGM) of two positive real numbers and is defined as follows:
Call and and :
Then define the two interdependent sequences and as
These two sequences converge to the same number, the arithmetic–geometric mean of and ; it is denoted by , or sometimes by .
The arithmetic-geometric mean is used in fast algorithms for exponential and trigonometric functions, as well as some mathematical constants, in particular, computing formula_3.
To find the arithmetic–geometric mean of and , iterate as follows:
The first five iterations give the following values:
The number of digits in which and agree (underlined) approximately doubles with each iteration. The arithmetic–geometric mean of 24 and 6 is the common limit of these two sequences, which is approximately .
The first algorithm based on this sequence pair appeared in the works of Lagrange. Its properties were further analyzed by Gauss.
The geometric mean of two positive numbers is never bigger than the arithmetic mean (see inequality of arithmetic and geometric means). As a consequence, for , is an increasing sequence, is a decreasing sequence, and . These are strict inequalities if .
If , then .
There is an integral-form expression for :
where is the complete elliptic integral of the first kind:
Indeed, since the arithmetic–geometric process converges so quickly, it provides an efficient way to compute elliptic integrals via this formula. In engineering, it is used for instance in elliptic filter design.
The reciprocal of the arithmetic–geometric mean of 1 and the square root of 2 is called Gauss's constant, after Carl Friedrich Gauss.
The geometric–harmonic mean can be calculated by an analogous method, using sequences of geometric and harmonic means. The arithmetic–harmonic mean can be similarly defined, but takes the same value as the geometric mean.
The arithmetic–geometric mean can be used to compute – among others – logarithms, complete and incomplete elliptic integrals of the first and second kind, and Jacobi elliptic functions.
From the inequality of arithmetic and geometric means we can conclude that:
and thus
that is, the sequence is nondecreasing.
Furthermore, it is easy to see that it is also bounded above by the larger of and (which follows from the fact that both the arithmetic and geometric means of two numbers lie between them). Thus, by the monotone convergence theorem, the sequence is convergent, so there exists a such that:
However, we can also see that:
and so:
Q.E.D.
This proof is given by Gauss.
Let
Changing the variable of integration to formula_14, where
gives
Thus, we have
The last equality comes from observing that formula_18.
Finally, we obtain the desired result
Gauss noticed that the sequences
as
have the same limit:
the arithmetic–geometric mean, "agm".
It is possible to use this fact to construct fast algorithms for calculating elementary transcendental functions and some classical constants, in particular, the constant .
For example, according to the Gauss–Salamin formula:
where
which can be computed without loss of precision using
Taking formula_26 , yields the "agm",
where is a complete elliptic integral of the first kind,
That is to say that this quarter period may be efficiently computed through the "agm",
Using this property of the AGM along with the ascending transformations of Landen, Richard Brent suggested the first AGM algorithms for the fast evaluation of elementary transcendental functions ("e""x", cos "x", sin "x"). Subsequently, many authors went on to study the use of the AGM algorithms. | https://en.wikipedia.org/wiki?curid=3090 |
Akira Toriyama
He earned the 1981 Shogakukan Manga Award for best "shōnen" or "shōjo" manga with "Dr. Slump", and it went on to sell over 35 million copies in Japan. It was adapted into a successful anime series, with a second anime created in 1997, 13 years after the manga ended. His next series, "Dragon Ball", would become one of the most popular and successful manga in the world. Having sold 250–300 million copies worldwide, it is the second best-selling manga of all time and is considered to be one of the main reasons for the period when manga circulation was at its highest in the mid-1980s and mid-1990s. Overseas, "Dragon Ball"s anime adaptations have been more successful than the manga and are credited with boosting anime's popularity in the Western world. In 2019, Toriyama was decorated a "Chevalier" of the French Ordre des Arts et des Lettres for his contributions to the arts.
Akira Toriyama was born in Nagoya, Aichi, Japan. He has recalled that when he was in elementary school all of his classmates drew, imitating anime and manga, as a result of not having many forms of entertainment. He believes that he began to advance above everyone else when he started drawing pictures of his friends, and after winning a prize at the local art studio for a picture of "One Hundred and One Dalmatians", began to think "art was fun".
Before becoming a manga artist, he worked at an advertising agency in Nagoya designing posters for three years. After quitting his previous job, Toriyama entered the manga industry by submitting a work to an amateur contest in a "Jump" magazine in order to win the prize money. While it did not win, Kazuhiko Torishima, who would later become his editor, contacted him and gave him encouragement. His debut came later in 1978 with the story "Wonder Island", which was published in "Weekly Shōnen Jump". However, he did not rise to popularity until the comedy series "Dr. Slump", which was serialized in "Weekly Shōnen Jump" from 1980 to 1984. It follows the adventures of a perverted professor and his small but super-strong robot Arale. He began the series at age 25 while living at home with his parents, but when the series ended in 1984 he was a "manga superstar". In 1981, "Dr. Slump" earned him the Shogakukan Manga Award for best "shōnen" or "shōjo" manga series of the year. A very successful anime adaptation aired on TV from 1981 to 1986, with a remake series airing from 1997 to 1999. By 2008, the manga had sold over 35 million copies in Japan.
Toriyama's official fan club was established in 1982. Its newsletters were called "Bird Land Press" and were sent to members until the club closed in 1987.
In 1984, "Weekly Shōnen Jump" began serializing Toriyama's "Dragon Ball", which became an instant hit. As of 2014, it had sold 159.5million "tankōbon" copies in Japan alone, making it Shueisha's second best-selling manga of all time. It began as an adventure/gag manga but later turned into a martial arts fighting series, considered by many to be the "most influential "shōnen" manga." "Dragon Ball" was one of the main reasons for the magazine's circulation hitting a record high of 6.53 million copies (1995). The series' success encouraged Toriyama to continue working on it from 1984 to 1995. At the series' end, Toriyama said that he asked everyone involved to let him end the manga, so he could "take some new steps in life." During that 11-year period, he produced 519 chapters that were collected into 42 volumes. Moreover, the success of the manga led to five anime adaptations, several animated movies, numerous video games, and mega-merchandising. The third anime adaptation, "Dragon Ball GT", was not based on his manga; however, Toriyama was still involved in coming up with the name and designing the main cast. Aside from its popularity in Japan, "Dragon Ball" was successful internationally as well, including Asia, Europe, and the Americas, with 250–300million copies of the manga sold worldwide.
While Toriyama was serializing "Dragon Ball" weekly, Torishima recruited him to work as character designer for the 1986 role-playing video game "Dragon Quest". The artist admitted he was pulled into it without even knowing what an RPG was and that it made his already busy schedule even more hectic, but he was happy to have been a part after enjoying the finished game. Toriyama has continued to work on every installment in the "Dragon Quest" series. He has also served as the character designer for the Super Famicom RPG "Chrono Trigger" and for the fighting games "Tobal No. 1" and "Tobal 2" for the PlayStation.
Toriyama's own studio is called Bird Studio, which is a play on his name; meaning "bird". Toriyama does nearly all of the work at Bird Studio himself, and even when he employed an assistant (until 1995, and only one at a time, which is itself rare for manga artists), the assistant did mostly backgrounds. The studio founded in 1983 has produced occasional one-shots, or stand-alone manga that are not serialized, and some other design work. All of Toriyama's manga after "Dragon Ball" tend to be short (100–200-page) stories, including "Cowa!", "Kajika", and "Sand Land".
On December 6, 2002, Toriyama made his only promotional appearance in the United States at the launch of "Weekly Shōnen Jump"'s North American counterpart, "Shonen Jump", in New York City. Toriyama's "Dragon Ball" and "Sand Land" were published in the magazine in the first issue, which also included an in-depth interview with him.
On March 27, 2005, CQ Motors began selling an electric car designed by Toriyama. The one-person QVOLT is part of the company's Choro-Q series of small electric cars, with only 9 being produced. It costs 1,990,000 yen (about $19,000 US), has a top speed of and is available in 5 colors. Designed to look like an American street rod, the QVOLT has a top and a door that are both opened by pulling a cord. Toriyama stated that the car took over a year to design, "but due to my genius mini-model construction skills, I finally arrived at the end of what was a very emotional journey."
He worked on a 2006 one-shot called "Cross Epoch", in cooperation with "One Piece" creator Eiichiro Oda. The story is a short crossover that presents characters from both "Dragon Ball" and "One Piece". Toriyama was the character designer and artist for the 2006 Mistwalker Xbox 360 exclusive RPG "Blue Dragon", working with Hironobu Sakaguchi and Nobuo Uematsu, both of whom he had previously worked with on "Chrono Trigger". He announced that his help with the making of the "Blue Dragon" anime might very well be his final work in anime. In his own words, he said:
In 2008, he collaborated with Masakazu Katsura, his good friend and creator of "I"s" and "Zetman", for the "Jump SQ" one-shot "Sachie-chan Good!!". It was later published in North America in the free SJ Alpha Yearbook 2013, which was mailed out to annual subscribers of the digital manga magazine "Shonen Jump Alpha" in December 2012. The two worked together again in 2009, for the three-chapter one-shot "Jiya" in "Weekly Young Jump".
Avex Trax commissioned Toriyama to draw a portrait of pop singer Ayumi Hamasaki; it was printed on the CD of her 2009 single "Rule/Sparkle", which was used as the theme song to the American live-action "Dragonball Evolution" film. Also in 2009, Toriyama drew a manga titled "Delicious Island's Mr. U" for Anjō's Rural Society Project, a nonprofit environmental organization that teaches the importance of agriculture and nature to young children. They originally asked him to do the illustrations for a pamphlet, but Toriyama liked the project and decided to expand it into a story. It is included in a booklet about environmental awareness that is distributed by the Anjō city government.
As part of "Weekly Shōnen Jump"s "Top of the Super Legend" project, a series of six one-shots by famed "Jump" artists, Toriyama created "Kintoki" for its November 15, 2010 issue. It was later released in North America's online manga anthology "Weekly Shonen Jump" on January 28, 2013.
He collaborated with "Weekly Shōnen Jump" to create a video to raise awareness and support for those affected by the 2011 Tōhoku earthquake and tsunami on March 11, 2011.
"", the series' first theatrical film in 17 years, opened on March 30, 2013 and marks the first time Toriyama has been deeply involved in an animation for the franchise, in this case as early as the screenwriting stages. A special "dual ticket" that can be used to see both "Battle of Gods" and "" was created with new art by both Toriyama and Eiichiro Oda.
On March 27, the "Akira Toriyama: The World of "Dragon Ball"" exhibit opened at the Takashimaya department store in Nihonbashi, garnering 72,000 visitors in its first nineteen days. The exhibit is separated into seven areas. The first provides a look at the series' history, the second shows the 400-plus characters from the series, the third displays Toriyama's manga manuscripts from memorable scenes, the fourth shows special color illustrations, the fifth displays rare "Dragon Ball"-related materials, the sixth includes design sketches and animation cels from the anime, and the seventh screens "Dragon Ball"-related videos. It was there until April 15, when it moved to Osaka from April 17 to 23, and ended in Toriyama's native Nagoya from July 27 to September 1.
To celebrate the 45th anniversary of "Weekly Shōnen Jump", Toriyama launched a new series in its July 13, 2013 issue titled "Jaco the Galactic Patrolman". Viz Media began serializing it in English in their digital "Weekly Shonen Jump" magazine, beginning just two days later. The final chapter reveals that the story is set before the events of "Dragon Ball" and features some of its characters.
The follow-up film to "Battle of Gods", "", released on April 18, 2015, features even more contributions from Toriyama, who personally wrote its original script. Toriyama provides the basic story outline and some character designs for "Dragon Ball Super", which began serialization in "V Jump" in June 2015 with an anime counterpart following in July. Although the anime ended in 2018, he continues to provide story ideas for the manga while Toyotarou illustrates it. "", released in theaters on December 14, 2018, continued Toriyama's deep involvement with the films.
Toriyama married his wife on May 2, 1982. She is a former manga artist from Nagoya under the pen name , and occasionally helped Toriyama and his assistant on "Dr. Slump" when they were short on time. They have two children: a son named born on March 23, 1987, and a daughter born in October 1990. Toriyama lives in his home studio in Kiyosu. He is a well-known recluse, who avoids appearing in public or media.
Toriyama has a love of cars and motorcycles, something he inherited from his father who used to race motorbikes and operated an auto repair business for a brief time, although he does not understand the mechanics himself. The author is an animal lover, having kept many different species of birds, dogs, cats, fish, lizards and bugs as pets since childhood. Some were used as models for characters he created such as Karin and Beerus. Toriyama has had a lifelong passion for plastic models, and has designed several for the Fine Molds brand. He also collected autographs of famous manga artists, having over 30 including Yudetamago and Hisashi Eguchi, a hobby he gave to Peasuke Soramame.
Toriyama admires Osamu Tezuka's "Astro Boy" and was impressed by Walt Disney's "One Hundred and One Dalmatians", which he remembers for its high-quality animation. Jackie Chan's early movies also had a noticeable influence on his stories, particularly Chan's martial arts comedy film "Drunken Master". Toriyama stated he was influenced by animator Toyoo Ashida and the anime television series adaptation of his own "Dragon Ball"; from which he learned that separating colors instead of blending them makes the art cleaner and coloring illustrations easier. It was Toriyama's sound effects in "Mysterious Rain Jack" that caught the eye of Kazuhiko Torishima, who explained that usually they are written in "katakana", but Toriyama used the Roman alphabet which he found refreshing. In his opinion, Torishima stated that Toriyama excels in black and white, utilizing black areas, as a result of not having had the money to buy screentone when he started drawing manga. He also described Toriyama as a master of convenience and "sloppy, but in a good way." For instance, in "Dragon Ball", destroying scenery in the environment and giving Super Saiyans blond hair were done in order to have less work in drawing and inking. Torishima claimed that Toriyama draws what he finds interesting and is not mindful of what his readers think.
"Dr. Slump" is mainly a comedy series, filled with puns, toilet humor and sexual innuendos. But it also contained many science fiction elements; aliens, anthropomorphic characters, time travel, and parodies of works such as Godzilla, "Star Wars" and "Star Trek". Toriyama also included many real-life people in the series, such as his assistants, wife and colleagues (such as Masakazu Katsura), but most notably his editor Kazuhiko Torishima as the series' main antagonist, Dr. Mashirito. A running gag in "Dr. Slump" that utilizes feces has been reported as an inspiration for the Pile of Poo emoji.
When "Dragon Ball" began, it was loosely based on the classic Chinese novel "Journey to the West", with Goku being Sun Wukong and Bulma as Tang Sanzang. It was also inspired by Hong Kong martial arts films, particularly those of Jackie Chan, and was set in a fictional world based on Asia, taking inspiration from several Asian cultures including Japanese, Chinese, South Asian, Central Asian, Arabic and Indonesian cultures. Toriyama continued to use his characteristic comedic style in the beginning, but over the course of time this slowly changed, with him turning the series into a "nearly-pure fighting manga" later on. He did not plan out in advance what would happen in the series, instead choosing to draw as he went. This, coupled with him simply forgetting things he had already drawn, caused him to find himself in situations that he had to write himself out of.
Toriyama was commissioned to illustrate the characters and monsters for the first "Dragon Quest" video game (1986) in order to separate it from other role-playing games of the time. He has since worked on every title in the series. For each game Yuji Horii first sends rough sketches of the characters with their background information to Toriyama, who then re-draws them. Lastly, Horii approves the finished work. Toriyama explained in 1995 that for video games, because the sprites are so small, as long as they have a distinguishing feature so people can tell which character it is, he can make complex designs without concern of having to reproduce it like he usually would in manga. Besides the character and monster designs, Toriyama also does the games' packaging art and, for "Dragon Quest VIII", the boats and ships. In 2016, Toriyama revealed that because of the series' established time period and setting, his artistic options are limited, which makes every iteration harder to design for than the last. The series' Slime character, which has become a sort of mascot for the franchise, is considered to be one of the most recognizable figures in gaming.
Manga critic Jason Thompson declared Toriyama's art influential, saying that his "extremely personal and recognizable style" was a reason for "Dragon Ball"'s popularity. He points out that the popular "shōnen" manga of the late 1980s and early 1990s had "manly" heroes, such as "City Hunter" and "Fist of the North Star", whereas "Dragon Ball" starred the cartoonish and small Goku, thus starting a trend that Thompson says continues to this day. Toriyama himself said he went against the normal convention that the strongest characters should be the largest in terms of physical size, designing many of the series' most powerful characters with small statures. Thompson concluded his analysis by saying that only Akira Toriyama drew like this at the time and that "Dragon Ball" is "an action manga drawn by a gag manga artist." However, James S. Yadao, author of "The Rough Guide to Manga", points out that an art shift does occur in the series, as the characters gradually "lose the rounded, innocent look that [Toriyama] established in "Dr. Slump" and gain sharper angles that leap off the page with their energy and intensity."
Thompson stated in 2011 that ""Dragon Ball" is by far the most influential shonen manga of the last 30 years, and today, almost every "Shōnen Jump" artist lists it as one of their favorites and lifts from it in various ways." David Brothers for ComicsAlliance wrote that: "Like Osamu Tezuka and Jack Kirby before him, Toriyama created a story with his own two hands that seeped deep into the hearts of his readers, creating a love for both the cast and the medium at the same time." In a rare 2013 interview, commenting on "Dragon Ball"'s global success, Toriyama admitted, "Frankly, I don't quite understand why it happened. While the manga was being serialized, the only thing I wanted as I kept drawing was to make Japanese boys happy." Many artists have named Toriyama and "Dragon Ball" as influences, including "One Piece" author Eiichiro Oda, "Naruto" creator Masashi Kishimoto, "Fairy Tail" and "Rave" author Hiro Mashima, "" illustrator Mikio Ikemoto, "Venus Versus Virus" author Atsushi Suzumi, "Bleach" creator Tite Kubo, "Black Cat" author Kentaro Yabuki, and "Mr. Fullswing" author Shinya Suzuki. German comic book artist Hans Steinbach was strongly influenced by Toriyama, and Thai cartoonist Wisut Ponnimit cited Toriyama as one of his favorite cartoonists. Ian Jones-Quartey, a producer of the American animated series "Steven Universe", is a fan of both "Dragon Ball" and "Dr. Slump", and uses Toriyama's vehicle designs as reference for his own. He also stated that "We're all big Toriyama fans on ["Steven Universe"], which kind of shows a bit."
In 2008, Oricon conducted a poll of people's favorite manga artists, with Toriyama coming in second, behind only "Nana" author Ai Yazawa. However, he was number one among male respondents and among those over 30 years of age. They held a poll on the Mangaka that Changed the History of Manga in 2010, "mangaka" being the Japanese word for a manga artist. Toriyama came in second, after only Osamu Tezuka, due to his works being highly influential and popular worldwide. Toriyama won the Special 40th Anniversary Festival Award at the 2013 Angoulême International Comics Festival, honoring his years in cartooning. He actually received the most votes for the festival's Grand Prix de la ville d'Angoulême award that year; however, the selection committee chose Willem as the recipient. Toriyama was decorated a "Chevalier" or "Knight" of the Ordre des Arts et des Lettres by the French government on May 30, 2019 for his contributions to the arts. He was also a 2019 nominee for entry into the Will Eisner Hall of Fame. Due to his video game design work, IGN named Toriyama number 74 on their list of the Top 100 Game Creators of All Time. | https://en.wikipedia.org/wiki?curid=3092 |
Epsilon Ursae Majoris
Epsilon Ursae Majoris (Latinised from ε Ursae Majoris, abbreviated Epsilon UMa, ε UMa), officially named Alioth , is, despite being designated "ε" (epsilon), the brightest star in the constellation of Ursa Major, and at magnitude 1.77 is the thirty-second brightest star in the sky.
It is the star in the tail of the bear closest to its body, and thus the star in the handle of the Big Dipper (or Plough) closest to the bowl. It is also a member of the large and diffuse Ursa Major moving group. Historically, the star was frequently used in celestial navigation in the maritime trade, because it is listed as one of the 57 navigational stars.
According to "Hipparcos", Epsilon Ursae Majoris is from the Sun. Its spectral type is A1p; the "p" stands for "peculiar", as its spectrum is characteristic of an α2 Canum Venaticorum variable. Epsilon Ursae Majoris, as a representative of this type, may harbor two interacting processes. First, the star's strong magnetic field separating different elements in the star's hydrogen 'fuel'. In addition, a rotation axis at an angle to the magnetic axis may be spinning different bands of magnetically sorted elements into the line of sight between Epsilon Ursae Majoris and the Earth. The intervening elements react differently at different frequencies of light as they whip in and out of view, causing Epsilon Ursae Majoris to have very strange spectral lines that fluctuate over a period of 5.1 days. The "kB9" suffix to the spectral type indicates that the calcium K line is present and representative of a B9 spectral type even though the rest of the spectrum indicates A1.
Epsilon Ursae Majoris's rotational and magnetic poles are at almost 90 degrees to one another. Darker (denser) regions of chromium form a band at right angles to the equator.
It has long been suspected that Epsilon Ursae Majoris is a spectroscopic binary, possibly with more than one companion. A more recent study suggests Epsilon Ursae Majoris's 5.1-day variation may be due to a substellar object of about 14.7 Jupiter masses in an eccentric orbit (e=0.5) with an average separation of 0.055 astronomical units. It is now thought that the 5.1-day period is the rotation period of the star, and no companions have been detected using the most modern equipment.
Epsilon Ursae Majoris has a relatively weak magnetic field, 15 times weaker than α Canum Venaticorum, but it is still 100 times stronger than that of the Earth.
"ε Ursae Majoris" (Latinised to "Epsilon Ursae Majoris") is the star's Bayer designation.
The traditional name "Alioth" comes from the Arabic "alyat al-hamal" ("the sheep's fat tail"). In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016 included a table of the first two batches of names approved by the WGSN; which included "Alioth" for this star.
This star was known to the Hindus as "Añgiras", one of the Seven Rishis.
In Chinese, (), meaning "Northern Dipper", refers to an asterism equivalent to the Big Dipper. Consequently, the Chinese name for Epsilon Ursae Majoris itself is (, ) and (, ).
USS Allioth (AK-109) was a United States Navy Crater class cargo ship named after the star. | https://en.wikipedia.org/wiki?curid=3093 |
Amiga 500
The Amiga 500, also known as the A500, is the first low-end Commodore Amiga 16/32-bit multimedia home/personal computer. It was announced at the winter Consumer Electronics Show in January 1987at the same time as the high-end Amiga 2000and competed directly against the Atari 520ST. Before it shipped Commodore suggested a list price of without a monitor. At delivery in October 1987 Commodore announced that the machine would carry a list price.
In Europe the Amiga 500 was released in May 1987. In the Netherlands it was available from April 1987 for a list price of 1499 HFL (US$730 in 1987).
The Amiga 500 represents a return to Commodore's roots by being sold in the same mass retail outlets as the Commodore 64to which it was a spiritual successoras opposed to the computer-store-only Amiga 1000, as well as being another computer whose keyboard is included in the same case.
The original Amiga 500 proved to be Commodore's best-selling Amiga model, enjoying particular success in Europe. Although popular with hobbyists, arguably its most widespread use was as a gaming machine, where its advanced graphics and sound were of significant benefit. It has been claimed that over 6 million A500s were sold worldwide, however, according to Commodore UK, the entire sales of all Amigas in both Europe and the USA were 4-5 million.
In October 1989, the Amiga 500 dropped its price from £499 to £399 and was bundled with the "Batman Pack" in the United Kingdom (from October 1989 to September 1990) which included the games "Batman", "F/A-18 Interceptor", "The New Zealand Story" and the bitmap graphics editor, Deluxe Paint 2. Also included was the Commodore A520 RF Modulator, an adaptor which allowed the A500 to be used with a conventional CRT television set, via its RF antenna socket.
In late 1991, an enhanced model known as the Amiga 500 Plus replaced the original 500 in some markets; it was bundled with the "Cartoon Classics" pack in the United Kingdom at £399, although many stores still advertised it as an 'A500'.
The Amiga 500 series was discontinued in June 1992 and replaced by the similarly specified and priced Amiga 600, although this new machine had originally been intended as a much cheaper model, which would have been the A300. In late 1992, Commodore released the "next-generation" Amiga 1200, a machine closer in concept to the original Amiga 500, but featuring significant technical improvements. Despite this, neither the A1200 nor the A600 replicated the commercial success of its predecessor, as by this time, the popular market was definitively shifting from the home computer platforms of the past to commodity Wintel PCs and the new "low-cost" Macintosh Classic, LC and IIsi models.
Outwardly resembling the Commodore 128 and codenamed "Rock Lobster" during development, the Amiga 500 houses the keyboard and CPU in one shell, unlike the Amiga 1000. It utilizes a Motorola 68000 microprocessor running at (NTSC) or (PAL). The CPU implements a 32-bit model, has 32-bit registers and 32-bit internal data bus, but it has a 16-bit main ALU, uses a 16-bit external data bus and 24-bit address bus, providing a maximum of 16 MB of address space.
The earliest Amiga 500 models use nearly the same Original Amiga chipset as the Amiga 1000. So graphics can be displayed in multiple resolutions and color depths, even on the same screen. Resolutions vary from 320×200 (up to 32 colors) to 640×400 (up to 16 colors) for NTSC (704×484 overscan) and 320×256 to 640×512 for PAL (704×576 overscan.) The system uses planar graphics, with up to five bitplanes (four in high resolution) allowing 2-, 4-, 8-, 16-, and 32-color screens, from a palette of 4096 colors. Two special graphics modes are also available: Extra HalfBrite, which uses a 6th bitplane as a mask to cut the brightness of any pixel in half (resulting in 32 arbitrary colors plus 32 more colors set at half the value of the first 32), and which allows all 4096 colors to be used on screen simultaneously. Later revisions of the chipset are PAL/NTSC switchable in software.
The sound chip produces four hardware-mixed channels, two to the left and two to the right, of 8-bit PCM at a sampling frequency of up to . Each hardware channel has its own independent volume level and sampling rate, and can be designated to another channel where it can modulate both volume and frequency using its own output. With DMA disabled it's possible to output with a sampling frequency up to . There's a common trick to output sound with 14-bit precision that can be combined to output 14-bit sound.
The stock system comes with AmigaOS version 1.2 or 1.3 and of chip RAM (150 ns access time), one built-in double-density standard floppy disk drive that is completely programmable and can read IBM PC disks, standard Amiga disks, and up to using custom-formatting drivers.
Despite the lack of Amiga 2000-compatible internal expansion slots, there are many ports and expansion options. There are two DE9M Atari joystick ports for joysticks or mice, stereo audio (RCA connectors 1 V p-p). There is a floppy drive port for daisy-chaining up to three extra floppy disk drives via an DB23F connector. The then-standard RS-232 serial port (DB25M) and Centronics parallel port (DB25F) are also included. The power supply is (, ).
The system displays video in analog RGB PAL or NTSC through a proprietary DB23M connector and in NTSC mode the line frequency is HSync for standard video modes, which is compatible with NTSC television and CVBS/RGB video, but out of range for most VGA-compatible monitors, while a multisync monitor is required for some of the higher resolutions. This connection can also be genlocked to an external video signal. The system was bundled with an RF adapter to provide output on televisions with a coaxial RF input, while monochrome composite video is available via an RCA connector (also coaxial). There is also a Zorro bus expansion on the left side (behind a plastic cover). Peripherals such as a hard disk drive can be added via the expansion slot and are configured automatically by the Amiga's AutoConfig standard, so that multiple devices do not conflict with each other. Up to of so-called "fast RAM" (memory that can be accessed by the CPU only) can be added using the side expansion slot. This connector is electronically identical with the Amiga 1000's, but swapped on the other side.
The Amiga 500 has a "trap-door" slot on the underside for a RAM upgrade (typically of ). This extra RAM is classified as "fast" RAM, but is sometimes referred to as "slow" RAM: due to the design of the expansion bus, it is actually on the chipset bus. Such upgrades usually include a battery-backed real-time clock. All versions of the A500 can have the additional RAM configured as chip RAM by a simple hardware modification, which involves fitting a later model (8372A) Agnus chip. Likewise, all versions of the A500 can be upgraded to chip RAM by fitting the chip and adding additional memory.
The Amiga 500 also sports an unusual feature for a budget machine, socketed chips, which allow easy replacement of defective chips. The CPU can be directly upgraded on the motherboard to a 68010; or to a 68020, 68030, or 68040 via the side expansion slot; or by removing the CPU and plugging a CPU expansion card into the CPU socket (though this will require opening the computer and voiding any remaining warranty). In fact, all the custom chips can be upgraded to the Amiga Enhanced Chip Set (ECS) versions.
The case is made from ABS plastics which may become brown with time. This may be reversed by using the public-domain chemical mix "Retr0bright", though without a clearcoat to block oxygen, the brown colouring will return.
Whenever the computer is powered on a self-diagnostic test is run that will show any failure with a specific colour where medium green means no chip RAM found or is damaged, red means bad kickstart-ROM, yellow means the CPU has crashed (no trap routine or trying to run bad code) or a bad Zorro expansion card.
Stopping on means that the CIA might be defective. mean there is a ROM or CIA problem, while
The keyboard LED uses blink codes: one blink means the keyboard ROM has a checksum error, two blinks means RAM failure, three blinks means watchdog timer failure. Using Caps Lock key and getting a response means CIA and the CPU works. There is no guarantee that every blinking state or color is accurate. Remember when the diagnostic codes are triggered it means the computer has some kind of fault and it can easily mis-interpret the fault and give false readings. For example, if the screen flashes green it can mean the Agnus is bad, the Agnus socket is bad, the logic connected to the Agnus is bad, the logic connected to the CPU is bad, the logic connected to the RAM is bad, a connection between CPU and/or logic and/or Agnus and/or Chip RAM is bad and/or some/all of the chip RAM is faulty etc. etc. Many of the issues with Amigas are caused by damage from corrosion or poor repair skills, especially the A500+ which has a Ni-Cad battery fitted and is always corroded if the battery has not been removed. Likewise a corroded battery on an A501 can cause faults on the A500 motherboard if the corrosion is very bad and has spread to the motherboard. The self-test chip RAM check is very brief and simplistic and all the other tests are minimalistic to minimize the start-up time (as documented in the Amiga Hardware Manual and many other official Commodore technical documents) so there is no guarantee that any of the diagnostic colours are 100% accurate.
Max 6 bpp. The Amiga can show multiple resolution modes at the same time, splitting the screen vertically. An additional mode called Hold-And-Modify (HAM) makes it possible to utilize over a wide span. This works by letting each pixel position use the previous RGB value and modify one of the red, green or blue values to a new 4-bit value. This will cause some negligible colour artifacts however.
A popular expansion for the Amiga 500 was the Amiga 501 circuit board that can be installed underneath the computer behind a plastic cover. The expansion contains RAM configured by default as "Slow RAM" or "trap-door RAM" and a battery-backed real-time clock (RTC). The 512 KB trap-door RAM and 512 KB of original chip RAM will result in 1 MB of total memory. By default, the expansion memory is handled and reported by the system as fast memory. However, the RAM is physically connected to Agnus like chip RAM and it is impacted by chip-bus bandwidth contention. Being only accessible by the CPU but as slow as chip RAM, it is commonly being referred to as "Slow RAM". The motherboard can be modified to relocate the trap-door RAM to the chip memory pool, provided a compatible Agnus chip is fitted on the motherboard.
Amiga 500 Buyers Guide Amiga 500 buyers guide | https://en.wikipedia.org/wiki?curid=3095 |
Amiga 1000
The Commodore Amiga 1000, also known as the A1000 and originally marketed as the Amiga, is the first personal computer released by Commodore International in the Amiga line. It combines the 16/32-bit Motorola 68000 CPU which was powerful by 1985 standards with one of the most advanced graphics and sound systems in its class, and runs a preemptive multitasking operating system that fits into of read-only memory and shipped with 256 KB of RAM. The primary memory can be expanded internally with a manufacturer-supplied 256 KB module for a total of 512 KB of RAM. Using the external slot the primary memory can be expanded up to
The A1000 has a number of characteristics that distinguish it from later Amiga models: It is the only model to feature the short-lived Amiga check-mark logo on its case, the majority of the case is elevated slightly to give a storage area for the keyboard when not in use (a "keyboard garage"), and the inside of the case is engraved with the signatures of the Amiga designers (similar to the Macintosh); including Jay Miner and the paw print of his dog Mitchy. The A1000's case was designed by Howard Stolz. As Senior Industrial Designer at Commodore, Stolz was the mechanical lead and primary interface with Sanyo in Japan, the contract manufacturer for the A1000 casing.
The Amiga 1000 was manufactured in two variations: One uses the NTSC television standard and the other uses the PAL television standard. The NTSC variant was the initial model manufactured and sold in North America. The later PAL model was manufactured in Germany and sold in countries using the PAL television standard. The first NTSC systems lack the EHB video mode which is present in all later Amiga models.
Because AmigaOS was rather buggy at the time of the A1000's release, the OS was not placed in ROM then. Instead, the A1000 includes a daughterboard with 256 KB of RAM, dubbed the "writable control store" (WCS), into which the core of the operating system is loaded from floppy disk (this portion of the operating system is known as the "Kickstart"). The WCS is write-protected after loading, and system resets do not require a reload of the WCS. In Europe, the WCS was often referred to as WOM (Write Once Memory), a play on the more conventional term "ROM" (read-only memory).
The preproduction Amiga (which was codenamed "Velvet") released to developers in early 1985 contained of RAM with an option to expand it to Commodore later increased the system memory to due to objections by the Amiga development team. The names of the custom chips were different; Denise and Paula were called Daphne and Portia respectively. The casing of the preproduction Amiga was almost identical to the production version: the main difference being an embossed Commodore logo in the top left corner. It did not have the developer signatures.
The Amiga 1000 has a Motorola 68000 CPU running at 7.15909 MHz (on NTSC systems) or 7.09379 MHz (PAL systems), precisely double the video color carrier frequency for NTSC or 1.6 times the color carrier frequency for PAL. The system clock timings are derived from the video frequency, which simplifies glue logic and allows the Amiga 1000 to make do with a single crystal. In keeping with its video game heritage, the chipset was designed to synchronize CPU memory access and chipset DMA so the hardware runs in real time without wait-state delays.
Though most units were sold with an analog RGB monitor, the A1000 also has a built-in composite video output which allows the computer to be connected directly to some monitors other than their standard RGB monitor. The A1000 also has a "TV MOD" output, into which an RF Modulator can be plugged, allowing connection to a TV that was old enough not to even have a composite video input.
The original 68000 CPU can be directly replaced with a Motorola 68010, which can execute instructions slightly faster than the 68000 but also introduces a small degree of software incompatibility. Third-party CPU upgrades, which mostly fit in the CPU socket, use faster successors 68020/68881 or 68030/68882 microprocessors and integrated memory. Such upgrades often have the option to revert to 68000 mode for full compatibility. Some boards have a socket to seat the original 68000, whereas the 68030 cards typically come with an on-board 68000.
The original Amiga 1000 is the only model to have 256 KB of Amiga Chip RAM, which can be expanded to 512 KB with the addition of a daughterboard under a cover in the center front of the machine. RAM may also be upgraded via official and third-party upgrades, with a practical upper limit of about 9 MB of "fast RAM" due to the 68000's 24-bit address bus. This memory is accessible only by the CPU permitting faster code execution as DMA cycles are not shared with the chipset.
The Amiga 1000 features an 86-pin expansion port (electrically identical to the later Amiga 500 expansion port, though the A500's connector is inverted). This port is used by third-party expansions such as memory upgrades and SCSI adapters. These resources are handled by the Amiga Autoconfig standard. Other expansion options are available including a bus expander which provides two Zorro-II slots.
Introduced on July 23, 1985, during a star-studded gala featuring Andy Warhol and Debbie Harry held at the Vivian Beaumont Theater at Lincoln Center in New York City, machines began shipping in September with a base configuration of 256 KB of RAM at the retail price of . A analog RGB monitor was available for around , bringing the price of a complete Amiga system to US$1,595 (). Before the release of the Amiga 500 and Amiga 2000 models in 1987, the A1000 was marketed as simply the "Amiga", although the model number was there from the beginning, as the original box indicates.
In the US, the A1000 was marketed as "The Amiga from Commodore", with the Commodore logo omitted from the case. The Commodore branding was retained for the international versions.
Additionally, the Amiga 1000 was sold exclusively in computer stores in the US rather than the various non computer-dedicated department and toy stores through which the VIC-20 and Commodore 64 were retailed. These measures were an effort to avoid Commodore's "toy-store" computer image created during the Tramiel era.
Along with the operating system, the machine came bundled with a version of AmigaBASIC developed by Microsoft and a speech synthesis library developed by Softvoice, Inc.
Many A1000 owners remained attached to their machines long after newer models rendered the units technically obsolete, and it attracted numerous aftermarket upgrades. Many CPU upgrades that plugged into the Motorola 68000 socket functioned in the A1000. Additionally, a line of products called the "Rejuvenator" series allowed the use of newer chipsets in the A1000, and an Australian-designed replacement A1000 motherboard called "The Phoenix" utilized the same chipset as the A3000 and added an A2000-compatible video slot and on-board SCSI controller.
In 1994, as Commodore filed for bankruptcy, "Byte" magazine called the Amiga 1000 "the first multimedia computer... so far ahead of its time that almost nobody—including Commodore's marketing department—could fully articulate what it was all about".
In 2006, "PC World" rated the Amiga 1000 as the 7th greatest PC of all time. In 2007, it was rated by the same magazine as the 37th best tech product of all time.
"Joe Pillow" was the name given on the ticket for the extra airline seat purchased to hold the first Amiga prototype while on the way to the January 1984 Consumer Electronics Show. The airlines required a name for the airline ticket and Joe Pillow was born. The engineers (RJ Mical and Dale Luck) who flew with the Amiga prototype (codenamed "Lorraine") drew a happy face on the front of the pillowcase and even added a tie.
Joe Pillow extended his fifteen minutes of fame when the Amiga went to production. All fifty-three Amiga team members who worked on the project signed the Amiga case. This included Joe Pillow and Jay Miner's dog Michy who each got to "sign" the case in their own unique way. | https://en.wikipedia.org/wiki?curid=3104 |
Asymptote
In analytic geometry, an asymptote () of a curve is a line such that the distance between the curve and the line approaches zero as one or both of the "x" or "y" coordinates tends to infinity. In projective geometry and related contexts, an asymptote of a curve is a line which is tangent to the curve at a point at infinity.
The word asymptote is derived from the Greek ἀσύμπτωτος ("asumptōtos") which means "not falling together", from ἀ priv. + σύν "together" + πτωτ-ός "fallen". The term was introduced by Apollonius of Perga in his work on conic sections, but in contrast to its modern meaning, he used it to mean any line that does not intersect the given curve.
There are three kinds of asymptotes: "horizontal", "vertical" and "oblique". For curves given by the graph of a function , horizontal asymptotes are horizontal lines that the graph of the function approaches as "x" tends to Vertical asymptotes are vertical lines near which the function grows without bound. An oblique asymptote has a slope that is non-zero but finite, such that the graph of the function approaches it as "x" tends to
More generally, one curve is a "curvilinear asymptote" of another (as opposed to a "linear asymptote") if the distance between the two curves tends to zero as they tend to infinity, although the term "asymptote" by itself is usually reserved for linear asymptotes.
Asymptotes convey information about the behavior of curves "in the large", and determining the asymptotes of a function is an important step in sketching its graph. The study of asymptotes of functions, construed in a broad sense, forms a part of the subject of asymptotic analysis.
The idea that a curve may come arbitrarily close to a line without actually becoming the same may seem to counter everyday experience. The representations of a line and a curve as marks on a piece of paper or as pixels on a computer screen have a positive width. So if they were to be extended far enough they would seem to merge, at least as far as the eye could discern. But these are physical representations of the corresponding mathematical entities; the line and the curve are idealized concepts whose width is 0 (see Line). Therefore, the understanding of the idea of an asymptote requires an effort of reason rather than experience.
Consider the graph of the function formula_1 shown to the right. The coordinates of the points on the curve are of the form formula_2 where x is a number other than 0. For example, the graph contains the points (1, 1), (2, 0.5), (5, 0.2), (10, 0.1), ... As the values of formula_3 become larger and larger, say 100, 1,000, 10,000 ..., putting them far to the right of the illustration, the corresponding values of formula_4, .01, .001, .0001, ..., become infinitesimal relative to the scale shown. But no matter how large formula_3 becomes, its reciprocal formula_6 is never 0, so the curve never actually touches the "x"-axis. Similarly, as the values of formula_3 become smaller and smaller, say .01, .001, .0001, ..., making them infinitesimal relative to the scale shown, the corresponding values of formula_4, 100, 1,000, 10,000 ..., become larger and larger. So the curve extends farther and farther upward as it comes closer and closer to the "y"-axis. Thus, both the "x" and "y"-axis are asymptotes of the curve. These ideas are part of the basis of concept of a limit in mathematics, and this connection is explained more fully below.
The asymptotes most commonly encountered in the study of calculus are of curves of the form . These can be computed using limits and classified into "horizontal", "vertical" and "oblique" asymptotes depending on their orientation. Horizontal asymptotes are horizontal lines that the graph of the function approaches as "x" tends to +∞ or −∞. As the name indicates they are parallel to the "x"-axis. Vertical asymptotes are vertical lines (perpendicular to the "x"-axis) near which the function grows without bound. Oblique asymptotes are diagonal lines such that the difference between the curve and the line approaches 0 as "x" tends to +∞ or −∞.
The line "x" = "a" is a "vertical asymptote" of the graph of the function if at least one of the following statements is true:
where formula_11 is the limit as "x" approaches the value "a" from the left (from lesser values), and formula_12 is the limit as "x" approaches "a" from the right.
For example, if ƒ("x") = "x"/("x"–1), the numerator approaches 1 and the denominator approaches 0 as "x" approaches 1. So
and the curve has a vertical asymptote "x"=1.
The function "ƒ"("x") may or may not be defined at "a", and its precise value at the point "x" = "a" does not affect the asymptote. For example, for the function
has a limit of +∞ as , "ƒ"("x") has the vertical asymptote , even though "ƒ"(0) = 5. The graph of this function does intersect the vertical asymptote once, at (0,5). It is impossible for the graph of a function to intersect a vertical asymptote (or a vertical line in general) in more than one point. Moreover, if a function is continuous at each point where it is defined, it is impossible that its graph does intersect any vertical asymptote.
A common example of a vertical asymptote is the case of a rational function at a point x such that the denominator is zero and the numerator is non-zero.
If a function has a vertical asymptote, then it isn't necessarily true that the derivative of the function has a vertical asymptote at the same place. An example is
This function has a vertical asymptote at formula_18 because
and
The derivative of formula_21 is the function
For the sequence of points
that approaches formula_25 both from the left and from the right, the values formula_26 are constantly formula_27. Therefore, both one-sided limits of formula_28 at formula_27 can be neither formula_30 nor formula_31. Hence formula_32 doesn't have a vertical asymptote at formula_25.
"Horizontal asymptotes" are horizontal lines that the graph of the function approaches as . The horizontal line "y" = "c" is a horizontal asymptote of the function "y" = "ƒ"("x") if
In the first case, "ƒ"("x") has "y" = "c" as asymptote when "x" tends to −∞, and in the second "ƒ"("x") has "y" = "c" as an asymptote as "x" tends to +∞
For example, the arctangent function satisfies
So the line is a horizontal asymptote for the arctangent when "x" tends to −∞, and is a horizontal asymptote for the arctangent when "x" tends to +∞.
Functions may lack horizontal asymptotes on either or both sides, or may have one horizontal asymptote that is the same in both directions. For example, the function has a horizontal asymptote at "y" = 0 when "x" tends both to −∞ and +∞ because, respectively,
When a linear asymptote is not parallel to the "x"- or "y"-axis, it is called an "oblique asymptote" or "slant asymptote". A function "f"("x") is asymptotic to the straight line ("m" ≠ 0) if
In the first case the line is an oblique asymptote of "ƒ"("x") when "x" tends to +∞, and in the second case the line is an oblique asymptote of "ƒ(x)" when "x" tends to −∞.
An example is ƒ("x") = "x" + 1/"x", which has the oblique asymptote "y" = "x" (that is "m" = 1, "n" = 0) as seen in the limits
The asymptotes of many elementary functions can be found without the explicit use of limits (although the derivations of such methods typically use limits).
The oblique asymptote, for the function "f"("x"), will be given by the equation "y"="mx"+"n". The value for "m" is computed first and is given by
where "a" is either formula_31 or formula_30 depending on the case being studied. It is good practice to treat the two cases separately. If this limit doesn't exist then there is no oblique asymptote in that direction.
Having "m" then the value for "n" can be computed by
where "a" should be the same value used before. If this limit fails to exist then there is no oblique asymptote in that direction, even should the limit defining "m" exist. Otherwise is the oblique asymptote of "ƒ"("x") as "x" tends to "a".
For example, the function has
so that is the asymptote of "ƒ"("x") when "x" tends to +∞.
The function has
So does not have an asymptote when "x" tends to +∞.
A rational function has at most one horizontal asymptote or oblique (slant) asymptote, and possibly many vertical asymptotes.
The degree of the numerator and degree of the denominator determine whether or not there are any horizontal or oblique asymptotes. The cases are tabulated below, where deg(numerator) is the degree of the numerator, and deg(denominator) is the degree of the denominator.
The vertical asymptotes occur only when the denominator is zero (If both the numerator and denominator are zero, the multiplicities of the zero are compared). For example, the following function has vertical asymptotes at "x" = 0, and "x" = 1, but not at "x" = 2.
When the numerator of a rational function has degree exactly one greater than the denominator, the function has an oblique (slant) asymptote. The asymptote is the polynomial term after dividing the numerator and denominator. This phenomenon occurs because when dividing the fraction, there will be a linear term, and a remainder. For example, consider the function
shown to the right. As the value of "x" increases, "f" approaches the asymptote "y" = "x". This is because the other term, 1/("x"+1), approaches 0.
If the degree of the numerator is more than 1 larger than the degree of the denominator, and the denominator does not divide the numerator, there will be a nonzero remainder that goes to zero as "x" increases, but the quotient will not be linear, and the function does not have an oblique asymptote.
If a known function has an asymptote (such as "y"=0 for "f"(x)="e""x"), then the translations of it also have an asymptote.
If a known function has an asymptote, then the scaling of the function also have an asymptote.
For example, "f"("x")="e""x"-1+2 has horizontal asymptote "y"=0+2=2, and no vertical or oblique asymptotes.
Let be a parametric plane curve, in coordinates "A"("t") = ("x"("t"),"y"("t")). Suppose that the curve tends to infinity, that is:
A line ℓ is an asymptote of "A" if the distance from the point "A"("t") to ℓ tends to zero as "t" → "b". From the definition, only open curves that have some infinite branch can have an asymptote. No closed curve can have an asymptote.
For example, the upper right branch of the curve "y" = 1/"x" can be defined parametrically as "x" = "t", "y" = 1/"t" (where "t" > 0). First, "x" → ∞ as "t" → ∞ and the distance from the curve to the "x"-axis is 1/"t" which approaches 0 as "t" → ∞. Therefore, the "x"-axis is an asymptote of the curve. Also, "y" → ∞ as "t" → 0 from the right, and the distance between the curve and the "y"-axis is "t" which approaches 0 as "t" → 0. So the "y"-axis is also an asymptote. A similar argument shows that the lower left branch of the curve also has the same two lines as asymptotes.
Although the definition here uses a parameterization of the curve, the notion of asymptote does not depend on the parameterization. In fact, if the equation of the line is formula_54 then the distance from the point "A"("t") = ("x"("t"),"y"("t")) to the line is given by
if γ("t") is a change of parameterization then the distance becomes
which tends to zero simultaneously as the previous expression.
An important case is when the curve is the graph of a real function (a function of one real variable and returning real values). The graph of the function "y" = "ƒ"("x") is the set of points of the plane with coordinates ("x","ƒ"("x")). For this, a parameterization is
This parameterization is to be considered over the open intervals ("a","b"), where "a" can be −∞ and "b" can be +∞.
An asymptote can be either vertical or non-vertical (oblique or horizontal). In the first case its equation is "x" = "c", for some real number "c". The non-vertical case has equation , where "m" and formula_58 are real numbers. All three types of asymptotes can be present at the same time in specific examples. Unlike asymptotes for curves that are graphs of functions, a general curve may have more than two non-vertical asymptotes, and may cross its vertical asymptotes more than once.
Let be a parametric plane curve, in coordinates "A"("t") = ("x"("t"),"y"("t")), and "B" be another (unparameterized) curve. Suppose, as before, that the curve "A" tends to infinity. The curve "B" is a curvilinear asymptote of "A" if the shortest distance from the point "A"("t") to a point on "B" tends to zero as "t" → "b". Sometimes "B" is simply referred to as an asymptote of "A", when there is no risk of confusion with linear asymptotes.
For example, the function
has a curvilinear asymptote , which is known as a "parabolic asymptote" because it is a parabola rather than a straight line.
Asymptotes are used in procedures of curve sketching. An asymptote serves as a guide line to show the behavior of the curve towards infinity. In order to get better approximations of the curve, curvilinear asymptotes have also been used although the term asymptotic curve seems to be preferred.
The asymptotes of an algebraic curve in the affine plane are the lines that are tangent to the projectivized curve through a point at infinity. For example, one may identify the asymptotes to the unit hyperbola in this manner. Asymptotes are often considered only for real curves, although they also make sense when defined in this way for curves over an arbitrary field.
A plane curve of degree "n" intersects its asymptote at most at "n"−2 other points, by Bézout's theorem, as the intersection at infinity is of multiplicity at least two. For a conic, there are a pair of lines that do not intersect the conic at any complex point: these are the two asymptotes of the conic.
A plane algebraic curve is defined by an equation of the form "P"("x","y") = 0 where "P" is a polynomial of degree "n"
where "P""k" is homogeneous of degree "k". Vanishing of the linear factors of the highest degree term "P""n" defines the asymptotes of the curve: setting , if , then the line
is an asymptote if formula_62 and formula_63 are not both zero. If formula_64 and formula_65, there is no asymptote, but the curve has a branch that looks like a branch of parabola. Such a branch is called a , even when it does not have any parabola that is a curvilinear asymptote. If formula_66 the curve has a singular point at infinity which may have several asymptotes or parabolic branches.
Over the complex numbers, "P""n" splits into linear factors, each of which defines an asymptote (or several for multiple factors). 0ver the reals, "P""n" splits in factors that are linear or quadratic factors. Only the linear factors correspond to infinite (real) branches of the curve, but if a linear factor has multiplicity greater than one, the curve may have several asymptotes or parabolic branches. It may also occur that such a multiple linear factor corresponds to two complex conjugate branches, and does not corresponds to any infinite branch of the real curve. For example, the curve has no real points outside the square formula_67, but its highest order term gives the linear factor "x" with multiplicity 4, leading to the unique asymptote "x"=0.
The hyperbola
has the two asymptotes
The equation for the union of these two lines is
Similarly, the hyperboloid
is said to have the asymptotic cone
The distance between the hyperboloid and cone approaches 0 as the distance from the origin approaches infinity.
More generally, consider a surface that has an implicit equation
formula_73
where the formula_74 are homogeneous polynomials of degree formula_75 and formula_76. Then the equation formula_77 defines a cone which is centered at the origin. It is called an asymptotic cone, because the distance to the cone of a point of the surface tends to zero when the point on the surface tends to infinity. | https://en.wikipedia.org/wiki?curid=3107 |
Andrew S. Tanenbaum
Andrew Stuart Tanenbaum (born March 16, 1944), sometimes referred to by the handle ast, is a Dutch-American computer scientist and professor emeritus of computer science at the Vrije Universiteit Amsterdam in the Netherlands.
He is best known as the author of MINIX, a free Unix-like operating system for teaching purposes, and for his computer science textbooks, regarded as standard texts in the field. He regards his teaching job as his most important work. Since 2004 he has operated Electoral-vote.com, a website dedicated to analysis of polling data in federal elections in the United States.
Tanenbaum was born in New York City and grew up in suburban White Plains, New York. He is Jewish. His paternal grandfather was born in Khorostkiv in the Austro-Hungarian empire.
He received his bachelor of Science degree in Physics from MIT in 1965 and his Ph.D. degree in astrophysics from the University of California, Berkeley in 1971. Tanenbaum also served as a lobbyist for the Sierra Club.
He moved to the Netherlands to live with his wife, who is Dutch, but he retains his United States citizenship. He teaches courses about Computer Organization and Operating Systems and supervises the work of Ph.D. candidates at the VU University Amsterdam. On , he announced his retirement.
Tanenbaum is well recognized for his textbooks on computer science. They include:
His book, "Operating Systems: Design and Implementation" and MINIX were Linus Torvalds' inspiration for the Linux kernel. In his autobiography "Just for Fun", Torvalds describes it as "the book that launched me to new heights".
His books have been translated into many languages including Arabic, Basque, Bulgarian, Chinese, Dutch, French, German, Greek, Hebrew, Hungarian, Italian, Japanese, Korean, Macedonian, Mexican Spanish, Persian, Polish, Portuguese, Romanian, Russian, Serbian, and Spanish. They have appeared in over 175 editions and are used at universities around the world.
Tanenbaum has had a number of Ph.D. students who themselves have gone on to become widely known computer science researchers.
These include:
In the early 1990s, the Dutch government began setting up a number of thematically oriented research schools that spanned multiple universities. These schools were intended to bring professors and Ph.D. students from different Dutch (and later, foreign) universities together to help them cooperate and enhance their research.
Tanenbaum was one of the cofounders and first Dean of the Advanced School for Computing and Imaging (ASCI). This school initially consisted of nearly 200 faculty members and Ph.D. students from the Vrije Universiteit, University of Amsterdam, Delft University of Technology, and Leiden University. They were especially working on problems in advanced computer systems such as parallel computing and image analysis and processing.
Tanenbaum remained dean for 12 years, until 2005, when he was awarded an Academy Professorship by the Royal Netherlands Academy of Arts and Sciences, at which time he became a full-time research professor. ASCI has since grown to include researchers from nearly a dozen universities in The Netherlands, Belgium, and France. ASCI offers Ph.D. level courses, has an annual conference, and runs various workshops every year.
The Amsterdam Compiler Kit is a toolkit for producing portable compilers. It was started sometime before 1981 and Andrew Tanenbaum was the architect from the start until version 5.5.
In 1987, Tanenbaum wrote a clone of UNIX, called MINIX (MINi-unIX), for the IBM PC. It was targeted at students and others who wanted to learn how an operating system worked. Consequently, he wrote a book that listed the source code in an appendix and described it in detail in the text. The source code itself was available on a set of floppy disks. Within three months, a Usenet newsgroup, comp.os.minix, had sprung up with over 40,000 subscribers discussing and improving the system. One of these subscribers was a Finnish student named Linus Torvalds, who began adding new features to MINIX and tailoring it to his own needs. On October 5, 1991, Torvalds announced his own (POSIX-like) kernel, called Linux, which originally used the MINIX file system but is not based on MINIX code.
Although MINIX and Linux have diverged, MINIX continues to be developed, now as a production system as well as an educational one. The focus is on building a highly modular, reliable, and secure operating system. The system is based on a microkernel, with only 5000 lines of code running in kernel mode. The rest of the operating system runs as a number of independent processes in user mode, including processes for the file system, process manager, and each device driver. The system continuously monitors each of these processes, and when a failure is detected is often capable of automatically replacing the failed process without a reboot, without disturbing running programs, and without the user even noticing. MINIX 3, as the current version is called, is available under the BSD license for free.
Tanenbaum has also been involved in numerous other research projects in the areas of operating systems, distributed systems, and ubiquitous computing, often as supervisor of Ph.D. students or a postdoctoral researcher. These projects include:
In 2004, Tanenbaum created Electoral-vote.com, a web site analyzing opinion polls for the 2004 U.S. Presidential Election, using them to project the outcome in the Electoral College. He stated that he created the site as an American who "knows first hand what the world thinks of America and it is not a pretty picture at the moment. I want people to think of America as the land of freedom and democracy, not the land of arrogance and blind revenge. I want to be proud of America again." The site provided a color-coded map, updated each day with projections for each state's electoral votes. Through most of the campaign period Tanenbaum kept his identity secret, referring to himself as "the Votemaster" and acknowledging only that he personally preferred John Kerry. Mentioning that he supported the Democrats, he revealed his identity on November 1, 2004, the day before the election, and also stating his reasons and qualifications for running the website.
Through the site he also covered the 2006 midterm elections, correctly predicting the winner of all 33 Senate races that year.
For the 2008 elections, he got every state right except for Indiana, which he said McCain would win by 2% (Obama won by 1%) and Missouri, which he said was too close to call (McCain won by 0.1%). He correctly predicted all the winners in the Senate except for Minnesota, where he predicted a 1% win by Norm Coleman over Al Franken. After 7 months of legal battling and recounts, Franken won by 312 votes (0.01%).
In 2010, he correctly projected 35 out of 37 Senate races in the Midterm elections on the website. The exceptions were Colorado and Nevada.
Electoral-vote.com incorrectly predicted Hillary Clinton would win the 2016 United States presidential election. The website incorrectly predicted Clinton would win Wisconsin, Michigan, Pennsylvania, North Carolina, and Florida. Electoral-vote.com did not predict a winner for Nevada, which Clinton would win. The website predicted the winners of the remaining 44 states and the District of Columbia correctly.
The Tanenbaum–Torvalds debate was a famous debate between Tanenbaum and Linus Torvalds regarding kernel design on Usenet in 1992.
Tanenbaum has been keynote speaker at numerous conferences, most recently | https://en.wikipedia.org/wiki?curid=3110 |
Ariane 5
Ariane 5 is a heavy-lift space launch vehicle developed and operated by Arianespace for the European Space Agency (ESA). It is launched from the Guiana Space Centre in French Guiana. It has been used to deliver payloads into geostationary transfer orbit (GTO) or low Earth orbit (LEO). A direct successor system, Ariane 6, is in development .
The system was originally designed as an expendable launch system by the "Centre national d'études spatiales" (CNES), the French government's space agency, in close cooperation with Germany and other European partners. Despite not being a direct derivative of its predecessor rocket program, it is classified as part of the Ariane rocket family. Airbus Defence and Space is the prime contractor for the vehicles, leading a multi-country consortium of other European contractors. ESA originally designed Ariane 5 to launch the "Hermes" spaceplane, and thus it is rated for human space launches.
Since its first launch, Ariane 5 has been refined in successive versions: "G", "G+", "GS", "ECA", and most recently, "ES". The system has a commonly used dual-launch capability, where up to two large geostationary belt communication satellites can be mounted using a SYLDA ("Système de Lancement Double Ariane", "Ariane Double-Launch System") carrier system. Up to three, somewhat smaller, main satellites are possible depending on size using SPELTRA ("Structure Porteuse Externe Lancement Triple Ariane", "Ariane Triple-Launch External Carrier Structure"). Up to eight secondary payloads, usually small experiment packages or minisatellites, can be carried with an ASAP (Ariane Structure for Auxiliary Payloads) platform.
As of 2020, Arianespace had signed contracts for Ariane 5 ECA launches up through 2023, approximately two to three years following the planned introduction of Ariane 6 in late 2020 or early 2021.
Ariane 5's cryogenic H173 main stage (H158 for Ariane 5 G, G+, and GS) is called the EPC ("Étage Principal Cryotechnique" — Cryotechnic Main Stage). It consists of a large tank 30.5 metres high with two compartments, one for liquid oxygen and one for liquid hydrogen, and a Vulcain 2 engine at the base with a vacuum thrust of . The H173 EPC weighs about 189 tonnes, including 175 tonnes of propellant. After the main cryogenic stage runs out of fuel, it re-enters the atmosphere for an ocean splashdown.
Attached to the sides are two P241 (P238 for Ariane 5 G and G+) solid rocket boosters (SRBs or EAPs from the French "Étages d'Accélération à Poudre"), each weighing about 277 tonnes full and delivering a thrust of about . They are fueled by a mix of ammonium perchlorate (68%) and aluminum fuel (18%) and HTPB (14%). They each burn for 130 seconds before being dropped into the ocean. The SRBs are usually allowed to sink to the bottom of the ocean, but, like the Space Shuttle Solid Rocket Boosters, they can be recovered with parachutes, and this has occasionally been done for post-flight analysis. (Unlike Space Shuttle SRBs, Ariane 5 boosters are not reused). The most recent attempt was for the first Ariane 5 ECA mission. One of the two boosters was successfully recovered and returned to the Guiana Space Center for analysis. Prior to that mission, the last such recovery and testing was done in 2003.
The French M51 SLBM shares a substantial amount of technology with these boosters.
In February 2000, the suspected nose cone of an Ariane 5 booster washed ashore on the South Texas coast, and was recovered by beachcombers before the government could get to it.
The second stage is on top of the main stage and below the payload. The original Ariane—Ariane 5 G—used the EPS ("Étage à Propergols Stockables" — Storable Propellant Stage), which was fueled by monomethylhydrazine (MMH) and nitrogen tetroxide, containing of storable propellant. The EPS was subsequently improved for use on the Ariane 5 G+, GS, and ES. Ariane 5 ECA uses the ESC ("Étage Supérieur Cryotechnique" — Cryogenic Upper Stage), which is fueled by liquid hydrogen and liquid oxygen.
The EPS upper stage is capable of multiple ignitions, first demonstrated during flight V26 which was launched on 5 October 2007. This was purely to test the engine, and occurred after the payloads had been deployed. The first operational use of restart capability as part of a mission came on 9 March 2008, when two burns were made to deploy the first Automated Transfer Vehicle into a circular parking orbit, followed by a third burn after ATV deployment to de-orbit the stage. This procedure was repeated for all subsequent ATV flights.
The payload and all upper stages are covered at launch by a fairing for aerodynamic stability and protection from heating during supersonic flight and acoustic loads. It is jettisoned once sufficient altitude has been reached (typically above 100 km). It is made by Ruag Space and since flight VA-238 it is composed of 4 panels.
Launch system status:
, the Ariane 5 commercial launch price for launching a "midsize satellite in the lower position" was approximately , competing for commercial launches in an increasingly competitive market.
The heavier satellite is launched in the upper position on a typical dual-satellite Ariane 5 launch is priced higher than the lower satellite, on the order of .
Total launch price of an Ariane 5 — which can transport up to two satellites to space, one in the "upper" and one in the "lower" positions — is around 150 million Euro as of January 2015.
The Ariane 5 ME (Mid-life Evolution) was in development into early 2015, and was seen as a stopgap between / and the new Ariane 6. With first flight planned for 2018, it would have become ESA's principal launcher until the arrival of the new Ariane 6 version. ESA halted funding for the development of Ariane 5 ME in late 2014 to prioritize development of Ariane 6
The Ariane 5 ME was to use a new upper stage, with increased propellant volume, powered by the new Vinci engine. Unlike the HM-7B engine, it was to be able restart several times, allowing for complex orbital maneuvers such as insertion of two satellites into different orbits, direct insertion into geosynchronous orbit, planetary exploration missions, and guaranteed upper stage deorbiting or insertion into graveyard orbit. The launcher was also to include a lengthened fairing up to 20 m and a new dual launch system to accommodate larger satellites. Compared to an Ariane 5 ECA model, the payload to GTO was to increase by 15% to 11.5 tonnes and the cost-per-kilogram of each launch is projected to decline by 20%.
Originally known as the Ariane 5 ECB, was to have its first flight in 2006. However, the failure of the first ECA flight in 2002, combined with a deteriorating satellite industry, caused ESA to cancel development in 2003. Development of the Vinci engine continued, though at a lower pace. The ESA Council of Ministers agreed to fund development of the new upper stage in November 2008.
In 2009, EADS Astrium was awarded a €200 million contract, and on April 10, 2012 received another €112 million contract to continue development of the Ariane 5 ME with total development effort expected to cost €1 billion.
On 21 November 2012, ESA agreed to continue with the Ariane 5 ME to meet the challenge of lower priced competitors. It was agreed the Vinci upper stage would also be used as the second stage of a new Ariane 6, and further commonality would be sought. Ariane 5 ME qualification flight was scheduled for mid-2018, followed by gradual introduction into service.
On 2 December 2014, ESA decided to stop funding the development of Ariane 5 ME and instead focus on Ariane 6, which was expected to have a lower cost per launch and allow more flexibility in the payloads (using two or four P120C solid boosters depending on total payload mass).
Work on the Ariane 5 EAP motors has been continued in the Vega programme. The Vega 1st stage engine — the P80 engine — is a shorter derivation of the EAP. The P80 booster casing is made of filament wound graphite epoxy, much lighter than the current stainless steel casing. A new composite steerable nozzle has been developed while new thermal insulation material and a narrower throat improve the expansion ratio and subsequently the overall performance. Additionally, the nozzle now has electromechanical actuators which have replaced the heavier hydraulic ones used for thrust vector control.
These developments will probably later make their way back into the Ariane programme. The incorporation of the ESC-B with the improvements to the solid motor casing and an uprated Vulcain engine would deliver to LEO. This would be developed for any lunar missions but the performance of such a design may not be possible if the higher Max-Q for the launch of this rocket poses a constraint on the mass delivered to orbit.
The design brief of the next generation rocket called for a lower-cost and smaller rocket capable of launching a single satellite of up to 6.5 tonnes to GTO. However, after several permutations the finalized design was nearly identical in performance to the Ariane 5, focusing instead on lowering fabrication costs and launch prices.
Development is projected to cost €4 billion. In 2018, its first test launch was set to not earlier than July 2020. , Ariane 6 was projected to be launched for about €70 million per flight or about half of the Ariane 5 current price.
Ariane 5's first test flight (Ariane 5 Flight 501) on 4 June 1996 failed, with the rocket self-destructing 37 seconds after launch because of a malfunction in the control software. A data conversion from 64-bit floating point value to 16-bit signed integer value to be stored in a variable representing horizontal bias caused a processor trap (operand error) because the floating point value was too large to be represented by a 16-bit signed integer. The software was originally written for the Ariane 4 where efficiency considerations (the computer running the software had an 80% maximum workload requirement) led to four variables being protected with a handler while three others, including the horizontal bias variable, were left unprotected because it was thought that they were "physically limited or that there was a large margin of safety". The software, written in Ada, was included in the Ariane 5 through the reuse of an entire Ariane 4 subsystem despite the fact that the particular software containing the bug, which was just a part of the subsystem, was not required by the Ariane 5 because it has a different preparation sequence than the Ariane 4.
The second test flight (L502, on 30 October 1997) was a partial failure. The Vulcain nozzle caused a roll problem, leading to premature shutdown of the core stage. The upper stage operated successfully, but it could not reach the intended orbit. A subsequent test flight (L503, on 21 October 1998) proved successful and the first commercial launch (L504) occurred on 10 December 1999 with the launch of the XMM-Newton X-ray observatory satellite.
Another partial failure occurred on 12 July 2001, with the delivery of two satellites into an incorrect orbit, at only half the height of the intended GTO. The ESA Artemis telecommunications satellite was able to reach its intended orbit on 31 January 2003, through the use of its experimental ion propulsion system.
The next launch did not occur until 1 March 2002, when the Envisat environmental satellite successfully reached an orbit above the Earth in the 11th launch. At , it was the heaviest single payload until the launch of the first ATV on 9 March 2008 (19,360 kg).
The first launch of the ECA variant on 11 December 2002 ended in failure when a main booster problem caused the rocket to veer off-course, forcing its self-destruction three minutes into the flight. Its payload of two communications satellites (Stentor and Hot Bird 7), valued at about EUR 630 million, was lost in the Atlantic ocean. The fault was determined to have been caused by a leak in coolant pipes allowing the nozzle to overheat. After this failure, Arianespace SA delayed the expected January 2003 launch for the Rosetta mission to 26 February 2004, but this was again delayed to early March 2004 due to a minor fault in the foam that protects the cryogenic tanks on the Ariane 5. As of June 2017, the failure of the first ECA launch was the last failure of an Ariane 5; since then, 82 consecutive launches have been successful, from April 2003 with the launch of INSAT-3A and Galaxy 12 satellites, to flight 240 in December 2017.
On 27 September 2003, the last Ariane 5 G boosted three satellites (including the first European lunar probe, SMART-1), in Flight 162. On 18 July 2004, an Ariane 5 G+ boosted what was at the time the heaviest telecommunication satellite ever, Anik F2, weighing almost .
The first successful launch of the Ariane 5 ECA took place on 12 February 2005. The payload consisted of the XTAR-EUR military communications satellite, a 'SLOSHSAT' small scientific satellite and a MaqSat B2 payload simulator. The launch had been originally scheduled for October 2004, but additional testing and the military requiring a launch at that time (of a Helios 2A observation satellite) delayed the attempt.
On 11 August 2005, the first Ariane 5 GS (featuring the Ariane 5 ECA's improved solid motors) boosted Thaïcom-4/iPStar-1, the heaviest telecommunications satellite to date at , into orbit.
On 16 November 2005, the third Ariane 5 ECA launch (the second successful ECA launch) took place. It carried a dual payload consisting of Spaceway-F2 for DirecTV and Telkom-2 for PT Telekomunikasi of Indonesia. This was the rocket's heaviest dual payload to date, at more than .
On 27 May 2006, an Ariane 5 ECA rocket set a new commercial payload lifting record of 8.2 tonnes. The dual-payload consisted of the Thaicom 5 and Satmex 6 satellites.
On 4 May 2007, the Ariane 5 ECA set another new commercial record, lifting into transfer orbit the Astra 1L and Galaxy 17 communication satellites with a combined weight of 8.6 tonnes, and a total payload weight of 9.4 tonnes. This record was again broken by another Ariane 5 ECA, launching the Skynet 5B and Star One C1 satellites, on 11 November 2007. The total payload weight for this launch was .
On 9 March 2008, the first Ariane 5 ES-ATV was launched to deliver the first ATV called "Jules Verne" to the International Space Station. The ATV was the heaviest payload ever launched by a European rocket, providing supplies to the space station with necessary propellant, water, air and dry cargo. This was the first operational Ariane mission which involved an engine restart in the upper stage. (The ES-ATV Aestus EPS upper stage was restartable while the ECA HM7-B engine was not).
On 1 July 2009, an Ariane 5 ECA launched TerreStar-1 (now EchoStar T1), which was then, at , the largest and most massive commercial telecommunication satellite ever built at that time until being overtaken by Telstar 19 Vantage, at , launched aboard Falcon 9 (although the satellite was launched into a lower-energy orbit than a usual GTO, with its initial apogee at roughly 17,900 km).
On 28 October 2010, an Ariane 5 ECA launched Eutelsat's W3B (part of its W Series of satellites) and Broadcasting Satellite System Corporation (B-SAT)'s BSAT-3b satellites into orbit. But the W3B satellite failed to operate shortly after the successful launch and was written off as a total loss due to an oxidizer leak in the satellite's main propulsion system. The BSAT-3b satellite, however, is operating normally.
On 22 April 2011, the Ariane 5 ECA flight VA-201 broke a commercial record, lifting Yahsat 1A and Intelsat New Dawn with a total payload weight of 10,064 kg to transfer orbit. This record was later broken again during the launch of Ariane 5 ECA flight VA-208 on 2 August 2012, lifting a total of 10,182 kg into the planned geosynchronous transfer orbit, which was broken again 6 months later on flight VA-212 with 10,317 kg sent towards geosynchronous transfer orbit. In June 2016 the GTO record was raised to 10,730 kg, on the first rocket in history that carried a satellite dedicated to financial institutions. The payload record was pushed a further 5 kg to on 24 August with the launch of Intelsat 33e and Intelsat 36. On 1 June 2017, the payload record was broken again to carrying ViaSat 2 and Eutelsat 172B.
On 25 January 2018, an Ariane 5 ECA launched SES-14 and Al Yah 3 satellites. About 9 minutes and 28 seconds after launch, a telemetry loss occurred between the rocket and the ground controllers. It was later confirmed, about 1 hour and 20 minutes after launch, that both satellites were successfully separated from the upper stage and were in contact with their respective ground controllers, but that their orbital inclinations were incorrect as the guidance systems might have been compromised. Therefore, both satellites conducted orbital procedures, extending commissioning time. SES-14 needed about 4 weeks longer than planned commissioning time, meaning that entry into service was reported early September instead of July. Nevertheless, SES-14 is still expected to be able to meet the designed lifetime. This satellite was originally to be launched with more propellant reserve on a Falcon 9 rocket since the Falcon 9, in this specific case, was intended to deploy this satellite into a high inclination orbit that would require more work from the satellite to reach its final geostationary orbit. The Al Yah 3 was also confirmed healthy after more than 12 hours without further statement, and like SES-14, Al Yah 3's maneuvering plan was also revised to still fulfill the original mission. As of 16 February 2018, Al Yah 3 was approaching the intended geostationary orbit, after series of recovery maneuvers had been performed. The investigation showed that invalid inertial units' azimuth value had sent the vehicle 17° off course but to the intended altitude, they had been programmed for the standard geostationary transfer orbit of 90° when the payloads were intended to be 70° for this supersynchronous transfer orbit mission, 20° off norm. This mission anomaly marked the end of 82nd consecutive success streak since 2003.
Ariane 5 rockets have accumulated 107 launches since 1996, 102 of which were successful, yielding a success rate. Between April 2003 and December 2017, Ariane 5 flew 82 consecutive missions without failure, but the rocket suffered a partial failure in January 2018.
All launches are from Centre Spatial Guyanais, Kourou, ELA-3. | https://en.wikipedia.org/wiki?curid=3111 |
Arianespace
Arianespace SA is a multinational company founded in 1980 as the world's first commercial launch service provider. It undertakes the operation and marketing of the Ariane programme. The company offers a number of different launch vehicles: the heavy-lift Ariane 5 for dual launches to geostationary transfer orbit, the Soyuz-2 as a medium-lift alternative, and the solid-fueled Vega for lighter payloads.
, Arianespace had launched more than 550 satellites in 254 launches over years (236 Ariane missions minus the first 8 flights handled by CNES, 17 Soyuz-2 missions and 9 Vega missions). The first commercial flight managed by the new entity was Spacenet F1 launched on 23 May 1984. Arianespace uses the Guiana Space Center in French Guiana as its main launch site. Through shareholding in Starsem, it can also offer commercial Soyuz launches from the Baikonur spaceport in Kazakhstan. It has its headquarters in Évry-Courcouronnes, Essonne, France.
The formation of Arianespace SA is closely associated with the desire of several European nations to pursue joint collaboration in the field of space exploration and the formation of a pan-national organisation, the European Space Agency (ESA), to oversee such undertaking during 1973. Prior to the ESA's formation, France had been lobbying for the development of a new European expendable launch system to serve as a replacement for the Europa rocket. Accordingly, one of the first programmes launched by the ESA was the Ariane heavy launcher. The express purpose of this launcher was to facilitate the delivery of commercial satellites into geosynchronous orbit.
France was the largest stakeholder in the Ariane development programme. French aerospace manufacturer Aérospatiale served as the prime contractor and held responsibility for performing the integration of all sections of the vehicle, while French engine manufacturer Société Européenne de Propulsion (SEP) provided both the first and second stage engines (the third stage engines were produced by Air Liquide and German aerospace manufacturer MBB). Other major companies involved included the French electronics firm Matra, Swedish manufacturer Volvo, and German aircraft producer Dornier Flugzeugwerke. Development of the third stage was a major focus point for the project - prior to Ariane, only the United States had ever flown a launcher that utilised hydrogen-powered upper stages.
Immediately following the successful first test launch of an Ariane 1 on 24 December 1979, the French space agency Centre national d'études spatiales (CNES) and the ESA created a new company, "Arianespace", for the purpose of promoting, marketing, and managing Ariane operations. According to Arianespace, at the time of its establishment, it was the world's first launch services company. Following a further three test launches, the first commercial launch took place on 10 September 1982, which ended in failure as a result of a turbopump having failed in the third stage. The six remaining flights of the Ariane 1 were successful, with the final flight occurring during February 1986. As a result of these repeated successes, orders for the Ariane launcher quickly mounted up; by early 1984, a total of 27 satellites had been booked to use Ariane, which was estimated to be half of the world's market at that time. As a result of the commercial success, after the tenth Ariane mission was flown, the ESA formally transferred responsibility for Ariane over to Arianespace.
By early 1986, the Ariane 1, along with its Ariane 2 and Ariane 3 derivates, were the dominant launcher on the world market. The Ariane 2 and Ariane 3 were short-lived platforms while the more extensive Ariane 4 was being developed; it was a considerably larger and more flexible launcher that the earlier members of its family, having been intended from the onset to compete with the upper end of launchers worldwide. In comparison, while the Ariane 1 had a typical weight of 207 tonnes and could launch payloads of up to 1.7 tonnes into orbit; the larger Ariane 4 had a typical weight of 470 tonnes and could orbit payloads of up to 4.2 tonnes. Despite this, the Ariane 4 was actually 15 per cent smaller than the Ariane 3.
On 15 June 1988, the first successful launch of the Ariane 4 was conducted. This maiden flight was considered a success, having placed multiple satellites into orbit. For the V50 launch onwards, an improved third stage, known as the "H10+", was adopted for the Ariane 4, which raised the rocket's overall payload capacity by 110 kg and increased its burn time by 20 seconds. In January 1985, the Ariane 5 was officially adopted as an ESA programme, and began an eleven-year development and test program to the first launch in 1996. It lacked the high levels of commonality that the Ariane 4 had with its predecessors, and had been designed not only for launching heavier payloads of up to 5.2 tonnes and at a 20 per cent cost reduction over the Ariane 4, but for a higher margin of safety due to the fact that the Ariane 5 was designed to conduct crewed space launches as well, being intended to transport astronauts using the proposed Hermes space vehicle. Development of the Ariane 5 was not without controversy as some ESA members considered the mature Ariane 4 platform to be more suited for meeting established needs for such launchers; it was reportedly for this reason that Britain chose not to participate in the Ariane 5 programme. For several years, Ariane 4 and Ariane 5 launchers were operated interchangeably; however, it was eventually decided to terminate all Ariane 4 operations in favour of concentrating on the newer Ariane 5.
During the mid-1990s, French firms Aérospatiale and SEP, along with Italian firm Bombrini-Parodi-Delfino (BPD), held discussions on the development of a proposed Ariane Complementary Launcher (ACL). Simultaneously, Italy championed the concept of a new solid-propellant satellite launcher, referred to as Vega. During March 2003, contracts for Vega's development were signed by the ESA and CNES; Italy provided 65 per cent of funding while six additional nations contributed the remainder. In May 2004, it was reported that a contract was signed between commercial operator Arianespace and prime contractor ELV to perform vehicle integration at Kourou, French Guiana. On 13 February 2012, the first launch of the Vega took place; it was reported as being an "apparently perfect flight". Since entering commercial service, Arianespace markets Vega as a launch system tailored for missions to polar and sun-synchronous orbits.
During 2002, the ESA announced the Arianespace Soyuz programme in cooperation with Russia; a launch site for Soyuz was constructed as the Guiana Space Centre, while the Soyuz launch vehicle was modified for use at the site. On 4 February 2005, both funding and final approval for the initiative were granted. Arianespace had offered launch services on the modified Soyuz ST-B to its clients. On 21 October 2011, Arianespace launched the first Soyuz rocket ever from outside former Soviet territory. The payload consisted of two Galileo navigation satellites. Since 2011, Arianespace has ordered a total of 23 Soyuz rockets, enough to cover its needs until 2019 at a pace of three to four launches per year.
On 21 January 2019, ArianeGroup and Arianespace announced that it had signed a one-year contract with the ESA to study and prepare for a mission to the Moon to mine regolith.
In 2020, Arianespace suspended operations for nearly two months due to the Covid-19 pandemic. Operations were suspended on 18 March and are, as of 29 April, expected to resume on 11 May. The return to operations will observe a number of new health and safety guidelines including social distancing in the workplace.
Arianespace "is the marketing and sales organization for the European space industry and various component suppliers."
The primary shareholders of Arianespace are its suppliers, in various European nations.
Arianespace had 24 shareholders in 2008, 21 in 2014,
and just 17 .
In 2015, Arianespace shareholding was restructured due to the creation of Airbus Safran Launchers (later renamed ArianeGroup), which is tasked with developing and manufacturing the Ariane 6 carrier rocket. Industrial groups Airbus and Safran pooled their shares along with the French government's CNES stake to form a partnership company holding just under 74% of Arianespace shares, while the remaining 26% is spread across suppliers in nine countries including further Airbus subsidiaries.
, the Arianespace management team was:
By 2004, Arianespace reportedly held more than 50% of the world market for boosting satellites to geostationary transfer orbit (GTO).
During the 2010s, the disruptive force represented by the new sector entrant SpaceX forced Arianespace to cut back on its workforce and focus on cost-cutting to decrease costs to remain competitive against the new low-cost entrant in the launch sector. In the midst of pricing pressure from such companies, during November 2013, Arianespace announced that it was enacting pricing flexibility for the "lighter satellites" that it carries to Geostationary orbits aboard its Ariane 5. According to Arianespace's managing director: "It's quite clear there's a very significant challenge coming from SpaceX (...) therefore things have to change (...) and the whole European industry is being restructured, consolidated, rationalised and streamlined."
During early 2014, Arianespace was considering requesting additional subsidies from European governments to face competition from SpaceX and unfavorable changes in the Euro-Dollar exchange rate. The company had halved subsidy support by €100m per year since 2002 but the fall in the value of the US Dollar meant Arianespace was losing €60m per year due to currency fluctuations on launch contracts. SpaceX had reportedly begun to take market share from Arianespace, Eutelsat CEO Michel de Rosen, a major customer of Arianespace, stated that: "Each year that passes will see SpaceX advance, gain market share and further reduce its costs through economies of scale."
By September 2014, Arianespace had reportedly to sign four additional contracts for lower slots on an Ariane 5 SYLDA dispenser for satellites that otherwise could be flown on a SpaceX launch vehicle; this was claimed to have been allowed via cost reductions; it had signed a total of 11 contracts by that point, while two additional ones that were under advanced negotiations. At the time, Arianespace has a backlog of launches worth billion with 38 satellites to be launched on Ariane 5, 7 on Soyuz and 9 on Vega, claiming 60% of the global satellite launch market.
Currently Arianespace operates 3 launch vehicles, including two versions of Ariane 5:
Additionally Arianespace offers optional back-up launch service on H-IIA through Launch Services Alliance.
Since the first launch in 1979, there have been several versions of the Ariane launch vehicle:
The new Ariane 6 vehicle is in development. It would have a similar payload capacity to the Ariane 5 but have considerably lower costs. Tentatively, its first flight is planned for 2020. | https://en.wikipedia.org/wiki?curid=3112 |
Amiga 500 Plus
The Commodore Amiga 500 Plus (often A500 Plus or simply A500+) is an enhanced version of the original Amiga 500 computer. It was notable for introducing new versions of Kickstart and Workbench, and for some minor improvements in the custom chips, known as the Enhanced Chip Set (or ECS).
The A500+ was released in several markets (including many European countries), but was never sold officially in the U.S.
Although officially introduced in 1992, some Amiga 500 Plus units had already been sold (masquerading as Amiga 500 models, and with no prior announcement) during late 1991. It has been speculated that Commodore had already sold out the remaining stocks of Amiga 500s, before the run-up to the profitable Christmas sales period. In order to make enough A500s before Christmas, Commodore used stocks of the new 8A revision motherboards destined for the A500+. Many users were unaware that they were purchasing anything other than a standard Amiga 500. Although the Amiga 500+ was an improvement to the Amiga 500, it was minor. It was discontinued and replaced by the Amiga 600 in summer 1992, making it the shortest-lived Amiga model.
Commodore created the A500+ for a couple of reasons. The first was cost reduction; minor changes were made to the motherboard to make it cheaper to produce. It was also so that Commodore could introduce the new version of the Amiga Operating system, 2.04.
Due to the new Kickstart, quite a few popular games (such as Treasure Island Dizzy, SWIV, and Lotus Esprit Turbo Challenge) failed to work on the Amiga 500+, and some people took them back to dealers demanding an original Kickstart 1.3 Amiga 500. This problem was solved by third parties who produced Kickstart ROM switching boards, that could allow the Amiga 500+ to be downgraded to Kickstart 1.2 or 1.3. It also encouraged game developers to use better programming habits, which was important since Commodore already had plans for the introduction of the next-generation Amiga 1200 computer. A program, Relokick, was also released (and included with an issue of CU Amiga) which loaded a Kickstart 1.3 ROM image into memory and booted the machine into Kickstart 1.3, allowing incompatible software to run. In some cases, updated compatible versions of games were later released, such as budget versions of Lotus 1 and SWIV. | https://en.wikipedia.org/wiki?curid=3114 |
Accumulator (computing)
In a computer's central processing unit (CPU), the accumulator is a register in which intermediate arithmetic and logic results are stored.
Without a register like an accumulator, it would be necessary to write the result of each calculation (addition, multiplication, shift, etc.) to main memory, perhaps only to be read right back again for use in the next operation. Access to main memory is slower than access to a register like the accumulator because the technology used for the large main memory is slower (but cheaper) than that used for a register. Early electronic computer systems were often split into two groups, those with accumulators and those without.
Modern computer systems often have multiple general purpose registers that operate as accumulators, and the term is no longer as common as it once was. However, a number of special-purpose processors still use a single accumulator for their work to simplify their design.
Mathematical operations often take place in a stepwise fashion, using the results from one operation as the input to the next. For instance, a manual calculation of a worker's weekly payroll might look something like:
A computer program carrying out the same task would follow the same basic sequence of operations, although the values being looked up would all be stored in computer memory. In early computers, the number of hours would likely be held on a punch card and the pay rate in some other form of memory, perhaps a magnetic drum. Once the multiplication is complete, the result needs to be placed somewhere. On a "drum machine" this would likely be back to the drum, an operation that takes considerable time. And then the very next operation has to read that value back in, which introduces another considerable delay.
Accumulators dramatically improve performance in systems like these by providing a scratchpad area where the results of one operation can be fed to the next one for little or no performance penalty. In the example above, the basic weekly pay would be calculated and placed in the accumulator, which could then immediately be used by the income tax calculation. This removes one save and one read operation from the sequence, operations that generally took tens to hundreds of times as long as the multiplication itself.
An accumulator machine, also called a 1-operand machine, or a CPU with "accumulator-based architecture", is a kind of CPU where, although it may have several registers, the CPU mostly stores the results of calculations in one special register, typically called "the accumulator". Almost all early computers were accumulator machines with only the high-performance "supercomputers" having multiple registers. Then as mainframe systems gave way to microcomputers, accumulator architectures were again popular with the MOS 6502 being a notable example. Many 8-bit microcontrollers that are still popular as of 2014, such as the PICmicro and 8051, are accumulator-based machines.
Modern CPUs are typically 2-operand or 3-operand machines. The additional operands specify which one of many general purpose registers (also called "general purpose accumulators") are used as the source and destination for calculations. These CPUs are not considered "accumulator machines".
The characteristic which distinguishes one register as being the accumulator of a computer architecture is that the accumulator (if the architecture were to have one) would be used as an "implicit" operand for arithmetic instructions. For instance, a CPU might have an instruction like: codice_1 that adds the value read from memory location "memaddress" to the value in the accumulator, placing the result back in the accumulator. The accumulator is not identified in the instruction by a register number; it is implicit in the instruction and no other register can be specified in the instruction. Some architectures use a particular register as an accumulator in some instructions, but other instructions use register numbers for explicit operand specification.
Any system that uses a single "memory" to store the result of multiple operations can be considered an accumulator. J. Presper Eckert refers to even the earliest adding machines of Gottfried Leibniz and Blaise Pascal as accumulator-based systems. Percy Ludgate was the first to conceive a multiplier-accumulator (MAC) in his Analytical Machine of 1909.
Historical convention dedicates a register to "the accumulator", an "arithmetic organ" that literally accumulates its number during a sequence of arithmetic operations:
Just a few of the instructions are, for example (with some modern interpretation):
No convention exists regarding the names for operations from registers to accumulator and from accumulator to registers. Tradition (e.g. Donald Knuth's (1973) hypothetical MIX computer), for example, uses two instructions called "load accumulator" from register/memory (e.g. "LDA r") and "store accumulator" to register/memory (e.g. "STA r"). Knuth's model has many other instructions as well.
The 1945 configuration of ENIAC had 20 accumulators, which could operate in parallel. Each one could store an eight decimal digit number and add to it (or subtract from it) a number it received. Most of IBM's early binary "scientific" computers, beginning with the vacuum tube IBM 701 in 1952, used a single 36-bit accumulator, along with a separate multiplier/quotient register to handle operations with longer results. The IBM 650, a decimal machine, had one 10 digit distributor and two ten-digit accumulators; the IBM 7070, a later, transistorized decimal machine had three accumulators. The IBM System/360, and Digital Equipment Corporation's PDP-6, had 16 general purpose registers, although the PDP-6 and its successor, the PDP-10, call them accumulators.
The 12-bit PDP-8 was one of the first minicomputers to use accumulators, and inspired many later machines. | https://en.wikipedia.org/wiki?curid=3116 |
Abu Zubaydah
Abu Zubaydah ( ; , "Abū Zubaydah"; born March 12, 1971, as Zayn al-Abidin Muhammad Husayn) is a Saudi Arabian citizen currently held by the U.S. in the Guantanamo Bay detention camp in Cuba. He is held under the authority of Authorization for Use of Military Force Against Terrorists (AUMF).
Zubaydah was captured in Pakistan in March 2002 and has been in United States custody ever since, including four-and-a-half years in the secret prison network of the Central Intelligence Agency (CIA). He was transferred among prisons in various countries including a year in Poland, as part of a United States' extraordinary rendition program. During his time in CIA custody, Zubaydah was extensively interrogated; he was water-boarded 83 times and subjected to numerous other torture techniques including forced nudity, sleep deprivation, confinement in small dark boxes, deprivation of solid food, stress positions, and physical assaults. Videotapes of some of Zubaydah's interrogations are amongst those destroyed by the CIA in 2005.
Zubaydah and ten other "high-value detainees" were transferred to Guantanamo in September 2006. He and other former CIA detainees are held in Camp 7, where conditions are the most isolating. At his Combatant Status Review Tribunal in 2007, Zubaydah said he was told that the CIA realized he was not significant.
On July 24, 2014, the European Court of Human Rights (ECHR) ordered the Polish government to pay Zubaydah €100,000 in damages. It also awarded him €30,000 to cover his costs. Poland cooperated with the US, allowing the CIA to hold and torture Zubaydah on its territory in 2002–2003. Zubaydah said through his US lawyer that he would be donating the full €100,000 in damages to victims of torture. Joseph Margulies was a lawyer for Zubaydah.
According to his younger brother Hesham, they had eight siblings. Hesham remembers his older brother "as a happy-go-lucky guy, and something of a womanizer." Born in Saudi Arabia, Zubaydah moved to the West Bank as a teenager, where he joined in Palestinian demonstrations against the Israelis. Zubaydah is reported to have studied computer science in Mysore, India prior to his travel to Afghanistan/Pakistan at the age of 20 in 1991. He joined the mujahideen in the Afghan civil war, perhaps serving under Mohamad Kamal Elzahabi. In 1992, Zubaydah was injured in a mortar shell blast, which left shrapnel in his head and caused severe memory loss, as well as the loss of the ability to speak for over one year.
Zubaydah eventually became involved in the jihad training site known as the Khalden training camp, where he oversaw the flow of recruits and obtained passports and paperwork for men transferring out of Khalden. He may also have worked as an instructor there. Although originally described as an al-Qaeda training camp, this alleged connection, which has been used as justification for holding Zubaydah and others as enemy combatants, has come under scrutiny from multiple sources, and the camp may have shut its doors in 2001 in response to an ideological division with al-Qaeda.
By 1999, the United States government was attempting to surveil Zubaydah. By March 2000, United States officials were reporting that Zubaydah was a "senior bin Laden official", the "former head of Egypt-based Islamic Jihad", a "trusted aide" to bin Laden with "growing power", who had "played a key role in the East Africa embassy attacks". Zubaydah was convicted "in absentia" in Jordan and sentenced to death by a Jordanian court for his role in plots to bomb U.S. and Israeli targets there. A senior Middle East security official said Zubaydah had directed the Jordanian cell and was part of "bin Laden's inner circle".
In August 2001, the classified FBI report, "Bin Ladin Determined To Strike in US", said that the foiled millennium bomber, Ahmed Ressam, had confessed that Zubaydah had encouraged him to blow up the Los Angeles airport and facilitated his mission. The report said that Zubaydah was also planning his own attack on the U.S. However, when Ressam was tried in December 2001, federal prosecutors did not try to connect him to Zubaydah or refer to any of this supposed evidence in its case. After the trial, Ressam recanted his confession, saying he had been coerced into giving it.
According to a psychological evaluation conducted upon his capture, Zubaydah allegedly served as Osama bin Laden's senior lieutenant and counter-intelligence officer (i.e. third or fourth highest-ranking member of al Qaeda), managed a network of training camps, was involved in every major terrorist operation carried out by al Qaeda (including the planning of 9/11), and was engaged in planning future terrorist attacks against U.S. interests. These statements were widely echoed by members of the Bush administration and other US officials. Zubaydah's perceived "value" as a detainee would later be used by President George W. Bush to justify the use of "enhanced interrogation techniques" and Zubaydah's detention in secret CIA prisons around the world. However, Zubaydah's connection to al Qaeda is now often said to have been—according to Rebecca Gordon writing about "The al Qaeda Leader Who Wasn't"—a fictitious charge. Others have said instead that it is merely overstated, and in response to his habeas corpus petition, the U.S. Government stated in 2009 that it did not contend Zubaydah had any involvement with the 9/11 attacks, or that he had even been a member of al Qaeda, simply because they did not have to: "In simple terms, the issue in this habeas corpus action is Petitioner's conduct", rather than membership or inclination: "Petitioner's personal philosophy is not relevant except to the extent that it is reflected in his actions".
On March 28, 2002, CIA and FBI agents, in conjunction with Pakistani intelligence agency, raided several safe houses in Pakistan searching for Zubaydah. Zubaydah was apprehended from one of the targeted safe houses in Faisalabad, Pakistan. The Pakistani intelligence service had paid a small amount for a tip on his whereabouts. The United States paid far more to Pakistan for its assistance; a CIA source later said: "We paid $10 million for Zubaydah."
During the raid, Zubaydah was shot in the thigh, the testicle, and the stomach with rounds from an AK-47 assault rifle. Not recognized at first, he was piled into a pickup truck along with other prisoners by the Pakistani forces, until a senior CIA officer identified him. He was taken by the Pakistanis to a Pakistani hospital nearby and treated for his wounds. The attending doctor told the CIA lead officer of the group which apprehended Zubaydah, that he had never before seen a patient survive such severe wounds. The CIA flew in a doctor from Johns Hopkins University to ensure Zubaydah would survive during transit out of Pakistan.
His pocket litter supposedly contained two bank cards which showed that he had access to Saudi and Kuwaiti bank accounts; most al-Qaeda members used the preferred, untraceable hawala banking. According to James Risen: "It is not clear whether an investigation of the cards simply fell through the cracks, or whether they were ignored because no one wanted to know the answers about connections between al Qaeda and important figures in the Middle East – particularly in Saudi Arabia." One of Risen's sources chalks up the failure to investigate the cards to incompetence rather than foul play: "The cards were sent back to Washington and were never fully exploited. I think nobody ever looked at them because of incompetence."
When Americans investigated the cards, Risen wrote that they worked with "a Muslim financier with a questionable past, and with connections to the Afghan Taliban, al Qaeda, and Saudi intelligence. ... Saudi intelligence officials had seized all of the records related to the card from the Saudi financial institution in question; the records then disappeared. There was no longer any way to trace the money that had gone into the account."
A search of the safehouse turned up Zubaydah's personal 10,000-page diaries, in which he recorded his thoughts as a young boy, old man, and at his current age. What appears to be split personalities is how Zubaydah was piecing his memories together after his 1992 shrapnel head wound. As part of his therapy to regain his memories, he began recording the diary that detailed his life, emotions, and what people were telling him. He split information into categories, such as what he knew about himself and what people told him, and listed them under different names to distinguish one set from the other. This was later incorrectly interpreted by some analysts reviewing the diary as symptoms of split personality disorder.
Zubaydah was handed to the CIA. Reports later alleged that he was transferred to secret CIA-operated prisons, known as black sites, in Pakistan, Thailand, Afghanistan, Poland, Northern Africa, and Diego Garcia. Historically, renditions of prisoners to countries which commit torture have been illegal. A memo written by John Yoo and signed by Jay Bybee of the Office of the Legal Counsel, DOJ, days before Zubaydah's capture, provided a legal opinion providing for CIA renditions of detainees to places such as Thailand. In March 2009, the U.S. Senate Intelligence Committee launched a year-long study on how the CIA operated the secret prisons, or black sites, around the world.
In the spring of 2002, immediately following the capture of Zubaydah, top Bush administration officials, Vice President Dick Cheney, Secretary of State Colin Powell, CIA Director George Tenet, National Security Adviser Condoleezza Rice, Secretary of Defense Donald Rumsfeld, and US Attorney General John Ashcroft discussed at length whether or not the CIA could legally use harsh techniques against him. Condoleezza Rice specifically mentioned the SERE program during the meeting, saying, "I recall being told that U.S. military personnel were subjected to training to certain physical and psychological interrogation techniques..."
In addition, in 2002 and 2003, the administration briefed several Democratic Congressional leaders on the proposed "enhanced interrogation techniques." These congressional leaders included Nancy Pelosi, the future Speaker of the House, and Representative Jane Harman. Congressional officials have stated that the attitude in the briefings ranged from "quiet acquiescence, if not downright support." The documents show that top U.S. Officials were intimately involved in the discussion and approval of the harsher interrogation techniques used on Zubaydah. Condoleezza Rice ultimately told the CIA the harsher interrogation tactics were acceptable, and Dick Cheney stated, "I signed off on it; so did others." During the discussions, US Attorney General John Ashcroft is reported as saying, "Why are we talking about this in the White House? History will not judge this kindly."
In December 2019, the New York Times published an article in partnership with the Pulitzer Center on Crisis Reporting which was based upon drawings made by Zubaydah, showing how he was tortured in "vivid and disturbing ways." The article includes some of the drawings as well as a link to a 61 page report titled "How America Tortures," and asserts that Zubaydah was never a member of Al Qaeda. In the article Zubaydah gives gruesome details of numerous types of torture including being locked up inside a small box called “the dog box” for “countless hours,” which caused muscle contractions. “The very strong pain,” he said, “made me scream unconsciously.”
Zubaydah was interrogated by two separate interrogation teams: the first from the FBI and one from the CIA. Ali Soufan, one of the FBI interrogators, later testified in 2009 on these issues to the Senate Committee that was investigating detainee treatment. Soufan, who witnessed part of the CIA interrogation of Zubaydah, described his treatment under the CIA as torture. The International Committee of the Red Cross and others later reached the same conclusion. While in CIA custody, Zubaydah lost his left eye.
Because of the urgency felt about the interrogation of Zubaydah, the CIA had consulted with the president about how to proceed. The General Counsel of the CIA asked for a legal opinion from the Office of Legal Counsel, Department of Justice about what was permissible during interrogation.
In early July 2002, the Associate General Council CTC/Legal Group started drafting a memo to the Attorney General requesting the approval of "aggressive" interrogation methods, which otherwise would be prohibited under the provisions of Section 2340-2340B, Title 18, United States Code, on Abu Zubaydah. This memo, drafted by Office of Legal Counsel, Jay Bybee and his assistant John Yoo, is also referred to as the first Torture Memo. Addressed to CIA acting General Counsel John A. Rizzo at his request, the purpose of the memo was to describe and authorize specific enhanced interrogation techniques to be used on Zubaydah. On July 26, 2002, Deputy Assistant Attorney General John Yoo informed the CIA that Attorney General John Ashcroft had approved waterboarding of Abu Zubaydah.
Journalists including Jane Mayer, Joby Warrick and Peter Finn, and Alex Koppelman have reported the CIA was already using these harsh tactics before the memo authorizing their use was written, and that it was used to provide after-the-fact legal support for harsh interrogation techniques. A Department of Justice 2009 report regarding prisoner abuses reportedly stated the memos were prepared one month after Zubaydah had already been subjected to the specific techniques authorized in August 1, 2002, memo. John Kiriakou stated in July 2009 that Zubaydah was waterboarded in the early summer of 2002, months before August 1, 2002, memo was written.
The memo described ten techniques which the interrogators wanted to use: "(1) attention grasp, (2) walling, (3) facial hold, (4) facial slap (insult slap), (5) cramped confinement, (6) wall standing, (7) stress positions, (8) sleep deprivation, (9) insects placed in a confinement box, and (10) the waterboard." Many of the techniques were, until then, generally considered illegal. Many other techniques developed by the CIA were held to constitute inhumane and degrading treatment and torture under the United Nations Convention against Torture and Article 3 of the European Convention on Human Rights.
As reported later, many of these interrogation techniques were previously considered illegal under U.S. and international law and treaties at the time of Zubaydah's capture. For instance, the United States had prosecuted Japanese military officials after World War II and American soldiers after the Vietnam War for waterboarding. Since 1930, the United States had defined sleep deprivation as an illegal form of torture. Many other techniques developed by the CIA constitute inhuman and degrading treatment and torture under the United Nations Convention against Torture, and Article 3 of the European Convention on Human Rights.
At a CIA black site in Thailand, Zubaydah was subjected to various forms of increasingly harsh interrogation techniques, including temperature extremes, music played at debilitating volumes, and sexual humiliation. Zubaydah was also subjected to beatings, isolation, waterboarding, long-time standing, continuous cramped confinement, and sleep deprivation.
Former CIA analyst and case officer John Kiriakou asserted that while Zubaydah was in CIA custody, a box of cockroaches were poured on him inside of a coffin he was confined to for two weeks, because of an irrational fear Zubaydah has of cockroaches.
During Zubaydah's interrogation, President Bush learned he was on painkillers for his wounds and was proving resistant. He said to the CIA director George Tenet, "Who authorized putting him on pain medication?" It was later reported that Zubaydah was denied painkillers during his interrogation.
Zubaydah was one of three or more high-value detainees to be waterboarded. The Bush administration in 2007 said that Zubaydah had been waterboarded once. John Kiriakou, a CIA officer who had seen the cables regarding Zubaydah's interrogation, publicly said in 2009 that Zubaydah was waterboarded once for 35 seconds before he started talking.
Intelligence sources claimed as early as 2008 that Zubaydah had been waterboarded no less than ten times in the span of one week. Zubaydah was waterboarded 83 times within the month of August 2002, the month the CIA was authorized to use this enhanced interrogation techniques for him. In January 2010, Kiriakou, in a memoir, said, "Now we know that Zubaydah was waterboarded eighty-three times in a single month, raising questions about how much useful information he actually supplied."
In August 2010, the Associated Press reported that the CIA, having concluded its agents had gotten most of the information from Zubaydah, in September 2003 transferred him and three other high-value detainees to Guantanamo. They were held at what was informally known as "Strawberry Fields," a secret camp within the complex built especially for former CIA detainees. Concerned that a pending Supreme Court decision, "Rasul v. Bush" (2004), might go against the Bush administration and require providing the prisoners with counsel and having to reveal data about them, on March 27, 2004, the CIA took the four men back into custody and transported them out of Guantanamo to one of their secret sites. At the time, the moves were all kept secret.
In February 2007, the International Committee of the Red Cross concluded a report on the treatment of "14 high-value detainees," who had been held by the CIA and, after September 2006, by the military at Guantanamo. The ICRC described the twelve enhanced interrogation techniques covered in the OLC memos to the CIA: suffocation by water (which is described as "torture" by numerous US officials), prolonged stress standing position, beatings by use of a collar, beating and kicking, confinement in a box, prolonged nudity, sleep deprivation, exposure to cold temperature, prolonged shackling, threats of ill-treatment, forced shaving, and deprivation/restricted provision of solid food. Zubaydah was the only detainee of the 14 interviewed who had been subjected to all 12 of these interrogation techniques. He was also the only one of the 14 detainees to be put into close confinement.
The final memo mentioned Zubaydah several times. It claimed that due to the enhanced interrogation techniques, Zubaydah "provided significant information on two operatives, [including] José Padilla[,] who planned to build and detonate a 'dirty bomb' in the Washington DC area." This claim is strongly disputed by Ali Soufan, the FBI interrogator who first interrogated Zubaydah following his capture, by traditional means. He said the most valuable information was gained before torture was used. Other intelligence officers have also disputed that claim. Soufan, when asked in 2009 by Senator Sheldon Whitehouse during a Congressional hearing if the memo was incorrect, testified that it was. The memo noted that not all of the waterboarding sessions were necessary for Zubaydah, since the on-scene interrogation team determined he had stopped producing actionable intelligence. The memo reads:
This is not to say that the interrogation program has worked perfectly. According to the IG Report, the CIA, at least initially, could not always distinguish detainees who had information but were successfully resisting interrogation from those who did not actually have the information. See IG Report at 83–85. On at least one occasion, this may have resulted in what might be deemed in retrospect to have been the unnecessary use of enhanced techniques. On that occasion, although the on-scene interrogation team judged Zubaydah to be compliant, elements within CIA Headquarters still believed he was withholding information. See id at 84. At the direction of CIA Headquarters, interrogators therefore used the waterboard one more time on Zubaydah.
John McLaughlin, former acting CIA director, stated in 2006, "I totally disagree with the view that the capture of Zubaydah was unimportant. Zubaydah was woven through all of the intelligence prior to 9/11 that signaled a major attack was coming, and his capture yielded a great deal of important information."
In his 2007 memoir, former CIA Director George Tenet writes:
A published report in 2006 contended that Zubaydah was mentally unstable and that the administration had overstated his importance. Baloney. Zubaydah had been at the crossroads of many al-Qa'ida operations and was in position to – and did – share critical information with his interrogators. Apparently, the source of the rumor that Zubaydah was unbalanced was his personal diary, in which he adopted various personas. From that shaky perch, some junior Freudians leapt to the conclusion that Zubaydah had multiple personalities. In fact, Agency psychiatrists eventually determined that in his diary he was using a sophisticated literary device to express himself. And, boy, did he express himself.
Zubaydah's capture was touted as the biggest of the War on Terror until that of Khalid Sheikh Mohammed. The director of the FBI stated Zubaydah's capture would help deter future attacks.
In a speech in 2006, President Bush claimed that Zubaydah revealed useful intelligence when enhanced interrogation was used, including identification of two important suspects and information that allegedly helped foil a terrorist attack on American soil. These claims directly conflict with the reports of the FBI agents who first interrogated Zubaydah. He gave them the names before torture was used, and the third piece of information came from other sources who had been receiving crucial pieces of information from him without the use of harsher techniques, as well as other government officials.
The Bush administration relied on some of Zubaydah's claims in justifying the invasion of Iraq. U.S. officials stated that the allegations that Iraq and al-Qaeda were linked in the training of people on chemical weapons came from Zubaydah. The officials noted there was no independent verification of his claims.
The U.S. government included statements made by Zubaydah in regards to al Qaeda's ability to obtain a dirty bomb to show a link between Iraq and al Qaeda. According to a Senate Intelligence Committee report of 2004, Zubaydah said that "he had heard that an important al Qaeda associate, Abu Musab al Zarqawi, and others had good relationships with Iraqi intelligence." However, the year before, in June 2003, Zubaydah and Khalid Sheikh Mohammed were reported as saying there was no link between Saddam Hussein and al Qaeda.
In the Senate Armed Services Committee 2008 report on the abuses of detainees, the Bush administration was described as having applied pressure to interrogators to find a link between Iraq and al Qaeda prior to the Iraq War. Major Paul Burney, a psychiatrist with the United States Army, said to the committee, "while we were [at Guantanamo] a large part of the time we were focused on trying to establish a link between al Qaeda and Iraq and we were not being successful." He said that higher-ups were "frustrated" and applied "more and more pressure to resort to measures that might produce more immediate results."
Colonel Lawrence B. Wilkerson, the former chief of staff for former Secretary of State Colin Powell said:
Likewise, what I have learned is that as the administration authorized harsh interrogation in April and May 2002—well before the Justice Department had rendered any legal opinion—its principal priority for intelligence was not aimed at pre-empting another terrorist attack on the U.S. but discovering a smoking gun linking Iraq and al-Qa'ida.
So furious was this effort that on one particular detainee, even when the interrogation team had reported to Cheney's office that their detainee "was compliant" (meaning the team recommended no more torture), the VP's office ordered them to continue the enhanced methods. The detainee had not revealed any al-Qa'ida-Baghdad contacts yet. This ceased only after Ibn al-Shaykh al-Libi, under waterboarding in Egypt, "revealed" such contacts. Of course, later we learned that al-Libi revealed these contacts only to get the torture to stop.
In 2004, media coverage of Abu Zubaydah began listing him as a "disappeared" prisoner, claiming he had no access to the International Red Cross. In February 2005, the CIA was reported as uncomfortable keeping Zubaydah in indefinite custody. Less than 18 months later, Zubaydah and the thirteen other high-value detainees who had been in secret CIA custody were transferred to the Guantanamo Bay detention camp.
After his transfer, the CIA denied access to Zubaydah. In 2008, the Office of the Inspector General, Department of Justice, complained that it had been prevented from seeing him, although it was conducting a study of the US treatment of its detainees.
Some people are concerned about Zubaydah's mental stability and how that has affected information he has given to interrogators. Ron Suskind noted in his book, "The One Percent Doctrine: Deep Inside America's Pursuit of Its Enemies Since 9/11" (2006), that Zubaydah was mentally ill or disabled due to a severe head injury. He described Zubaydah as keeping a diary "in the voice of three people: Hani 1, Hani 2, and Hani 3"—a boy, a young man and a middle-aged alter ego. Zubaydah's diaries spanned ten years and recorded in numbing detail "what he ate, or wore, or trifling things [people] said." Dan Coleman, then the FBI's top al-Qaeda analyst, told a senior bureau official, "This guy is insane, certifiable, split personality." According to Suskind, this judgment was "echoed at the top of CIA and was briefed to the President and Vice President." Coleman stated Zubaydah was a "safehouse keeper" with mental problems, who "claimed to know more about al-Qaeda and its inner workings than he really did."
Joseph Margulies, Zubaydah's co-counsel, wrote in an op-ed in the "Los Angeles Times":
Partly as a result of injuries he suffered while he was fighting the communists in Afghanistan, partly as a result of how those injuries were exacerbated by the CIA and partly as a result of his extended isolation, Zubaydah's mental grasp is slipping away. Today, he suffers blinding headaches and has permanent brain damage. He has an excruciating sensitivity to sounds, hearing what others do not. The slightest noise drives him nearly insane. In the last two years alone, he has experienced about 200 seizures. Already, he cannot picture his mother's face or recall his father's name. Gradually, his past, like his future, eludes him.
President Bush referred to Zubaydah in a speech to Congress September 2006 requesting a bill to authorize military commissions, following the U.S. Supreme Court ruling in "Hamdan v. Rumsfeld" (2006) that held the tribunals as formulated by the executive branch were unconstitutional. Congress rapidly passed legislation that was signed by the president.
Less than one month after Zubaydah's capture, Justice Department officials said Zubaydah was "a near-ideal candidate for a tribunal trial." Several months later in 2002, US officials said there was "no rush" to try Zubaydah via military commission.
At his Combatant Status Review Tribunal in 2007, Zubaydah said he was told that the CIA realized he was not significant.
"They told me, 'Sorry, we discover that you are not Number 3, not a partner, not even a fighter,' " said Zubaydah, speaking in broken English, according to the new transcript of a Combatant Status Review Tribunal held at the U.S. military prison in Guantanamo Bay, Cuba.
Abu Zubaydah's lawyers, including Joseph Margulies and George Brent Mickum IV, filed a lawsuit in July 2008 challenging his detention at Guantanamo Bay detention camps after the "Boumediene v. Bush" ruling. As of 2015, the judge overseeing the case, Richard W. Roberts, has failed to rule on any motions related to the case, even the preliminary ones. This has led Zubaydah's lawyers to file motion asking Judge Roberts to recuse himself for nonfeasance in January 2015. On March 16, 2016, Roberts retired early from the federal bench, citing unspecified health issues.
The U.S. Government has not officially charged Zubaydah with any crimes. The Senate Intelligence Committee report on CIA torture reported that Zubaydah's CIA interrogators wanted him to "remain in isolation and incommunicado for the remainder of his life."
When he assumed office in January 2009, President Barack Obama made a number of promises about the future of Guantanamo.
He promised the use of torture would cease at the camp. He promised to institute a new review system. That new review system was composed of officials from six departments, where the OARDEC reviews were conducted entirely by the Department of Defense. When it reported back, a year later, the Joint Review Task Force classified some individuals as too dangerous to be transferred from Guantanamo, even though there was no evidence to justify laying charges against them. On April 9, 2013, that document was made public after a Freedom of Information Act request.
Zayn al-lbidin Muhammed Husayn was one of the 71 individuals deemed too innocent to charge but too dangerous to release. Although Obama promised that those deemed too innocent to charge but too dangerous to release would start to receive reviews from a Periodic Review Board, less than a quarter of men have received a review.
On 24 July 2014, the European Court of Human Rights (ECHR) ruled that Poland had violated the European Convention on Human Rights when it cooperated with US allowing the CIA to hold and torture Zubaydah and Abd al-Rahim al-Nashiri on its territory in 2002–2003. The court ordered the Polish government to pay each of the men €100,000 in damages. It also awarded Zubaydah €30,000 to cover his costs.
On 31 May 2018, the ECHR ruled that Romania and Lithuania also violated the rights of Abu Zubaydah and Abd al-Rahim al-Nashiri in 2003–2005 and in 2005–2006 respectively, and Lithuania and Romania were ordered to pay 100,000 euros in damages each to Abu Zubaydah and Abd al-Nashiri. | https://en.wikipedia.org/wiki?curid=3117 |
Arithmetic
Arithmetic (from the Greek ἀριθμός "arithmos", 'number' and τική [τέχνη], "tiké [téchne]", 'art') is a branch of mathematics that consists of the study of numbers, especially the properties of the traditional operations on them—addition, subtraction, multiplication and division. Arithmetic is an elementary part of number theory, and number theory is considered to be one of the top-level divisions of modern mathematics, along with algebra, geometry, and analysis. The terms "arithmetic" and "higher arithmetic" were used until the beginning of the 20th century as synonyms for "number theory" and are sometimes still used to refer to a wider part of number theory.
The prehistory of arithmetic is limited to a small number of artifacts which may indicate the conception of addition and subtraction, the best-known being the Ishango bone from central Africa, dating from somewhere between 20,000 and 18,000 BC, although its interpretation is disputed.
The earliest written records indicate the Egyptians and Babylonians used all the elementary arithmetic operations as early as 2000 BC. These artifacts do not always reveal the specific process used for solving problems, but the characteristics of the particular numeral system strongly influence the complexity of the methods. The hieroglyphic system for Egyptian numerals, like the later Roman numerals, descended from tally marks used for counting. In both cases, this origin resulted in values that used a decimal base but did not include positional notation. Complex calculations with Roman numerals required the assistance of a counting board or the Roman abacus to obtain the results.
Early number systems that included positional notation were not decimal, including the sexagesimal (base 60) system for Babylonian numerals and the vigesimal (base 20) system that defined Maya numerals. Because of this place-value concept, the ability to reuse the same digits for different values contributed to simpler and more efficient methods of calculation.
The continuous historical development of modern arithmetic starts with the Hellenistic civilization of ancient Greece, although it originated much later than the Babylonian and Egyptian examples. Prior to the works of Euclid around 300 BC, Greek studies in mathematics overlapped with philosophical and mystical beliefs. For example, Nicomachus summarized the viewpoint of the earlier Pythagorean approach to numbers, and their relationships to each other, in his "Introduction to Arithmetic".
Greek numerals were used by Archimedes, Diophantus and others in a positional notation not very different from ours. The ancient Greeks lacked a symbol for zero until the Hellenistic period, and they used three separate sets of symbols as digits: one set for the units place, one for the tens place, and one for the hundreds. For the thousands place they would reuse the symbols for the units place, and so on. Their addition algorithm was identical to ours, and their multiplication algorithm was only very slightly different. Their long division algorithm was the same, and the digit-by-digit square root algorithm, popularly used as recently as the 20th century, was known to Archimedes, who may have invented it. He preferred it to Hero's method of successive approximation because, once computed, a digit doesn't change, and the square roots of perfect squares, such as 7485696, terminate immediately as 2736. For numbers with a fractional part, such as 546.934, they used negative powers of 60 instead of negative powers of 10 for the fractional part 0.934.
The ancient Chinese had advanced arithmetic studies dating from the Shang Dynasty and continuing through the Tang Dynasty, from basic numbers to advanced algebra. The ancient Chinese used a positional notation similar to that of the Greeks. Since they also lacked a symbol for zero, they had one set of symbols for the units place, and a second set for the tens place. For the hundreds place they then reused the symbols for the units place, and so on. Their symbols were based on the ancient counting rods. It is a complicated question to determine exactly when the Chinese started calculating with positional representation, but it was definitely before 400 BC. The ancient Chinese were the first to meaningfully discover, understand, and apply negative numbers as explained in the "Nine Chapters on the Mathematical Art" ("Jiuzhang Suanshu"), which was written by Liu Hui.
The gradual development of the Hindu–Arabic numeral system independently devised the place-value concept and positional notation, which combined the simpler methods for computations with a decimal base and the use of a digit representing 0. This allowed the system to consistently represent both large and small integers. This approach eventually replaced all other systems. In the early the Indian mathematician Aryabhata incorporated an existing version of this system in his work, and experimented with different notations. In the 7th century, Brahmagupta established the use of 0 as a separate number and determined the results for multiplication, division, addition and subtraction of zero and all other numbers, except for the result of division by zero. His contemporary, the Syriac bishop Severus Sebokht (650 AD) said, "Indians possess a method of calculation that no word can praise enough. Their rational system of mathematics, or of their method of calculation. I mean the system using nine symbols." The Arabs also learned this new method and called it "hesab".
Although the Codex Vigilanus described an early form of Arabic numerals (omitting 0) by 976 AD, Leonardo of Pisa (Fibonacci) was primarily responsible for spreading their use throughout Europe after the publication of his book "Liber Abaci" in 1202. He wrote, "The method of the Indians (Latin "Modus Indoram") surpasses any known method to compute. It's a marvelous method. They do their computations using nine figures and symbol zero".
In the Middle Ages, arithmetic was one of the seven liberal arts taught in universities.
The flourishing of algebra in the medieval Islamic world and in Renaissance Europe was an outgrowth of the enormous simplification of computation through decimal notation.
Various types of tools have been invented and widely used to assist in numeric calculations. Before Renaissance, they were various types of abaci. More recent examples include slide rules, nomograms and mechanical calculators, such as Pascal's calculator. At present, they have been supplanted by electronic calculators and computers.
The basic arithmetic operations are addition, subtraction, multiplication and division, although this subject also includes more advanced operations, such as manipulations of percentages, square roots, exponentiation, logarithmic functions, and even trigonometric functions, in the same vein as logarithms (prosthaphaeresis). Arithmetic expressions must be evaluated according to the intended sequence of operations. There are several methods to specify this, either—most common, together with infix notation—explicitly using parentheses, and relying on precedence rules, or using a prefix or postfix notation, which uniquely fix the order of execution by themselves. Any set of objects upon which all four arithmetic operations (except division by zero) can be performed, and where these four operations obey the usual laws (including distributivity), is called a field.
Addition is the most basic operation of arithmetic. In its simple form, addition combines two numbers, the "addends" or "terms", into a single number, the "sum" of the numbers (such as or ).
Adding finitely many numbers can be viewed as repeated simple addition; this procedure is known as summation, a term also used to denote the definition for "adding infinitely many numbers" in an infinite series. Repeated addition of the number 1 is the most basic form of counting; the result of adding is usually called the successor of the original number.
Addition is commutative and associative, so the order in which finitely many terms are added does not matter. The identity element for a binary operation is the number that, when combined with any number, yields the same number as the result. According to the rules of addition, adding to any number yields that same number, so is the additive identity. The "inverse of a number" with respect to a binary operation is the number that, when combined with any number, yields the identity with respect to this operation. So the inverse of a number with respect to addition (its additive inverse, or the opposite number) is the number that yields the additive identity, , when added to the original number; it is immediately obvious that this is the negative of the original number. For example, the additive inverse of is , since .
Addition can be interpreted geometrically as in the following example:
Subtraction is the inverse operation to addition. Subtraction finds the "difference" between two numbers, the "minuend" minus the "subtrahend": Resorting to the previously established addition, this is to say that the difference is the number that, when added to the subtrahend, results in the minuend:
For positive arguments and holds:
In any case, if minuend and subtrahend are equal, the difference
Subtraction is neither commutative nor associative. For that reason, in modern algebra the construction of this inverse operation is often discarded in favor of introducing the concept of inverse elements, as sketched under Addition, and to look at subtraction as adding the additive inverse of the subtrahend to the minuend, that is . The immediate price of discarding the binary operation of subtraction is the introduction of the (trivial) unary operation, delivering the additive inverse for any given number, and losing the immediate access to the notion of difference, which is potentially misleading when negative arguments are involved.
For any representation of numbers there are methods for calculating results, some of which are particularly advantageous in exploiting procedures, existing for one operation, by small alterations also for others. For example, digital computers can reuse existing adding-circuitry and save additional circuits for implementing a subtraction by employing the method of two's complement for representing the additive inverses, which is extremely easy to implement in hardware (negation). The trade-off is the halving of the number range for a fixed word length.
A formerly wide spread method to achieve a correct change amount, knowing the due and given amounts, is the "counting up method", which does not explicitly generate the value of the difference. Suppose an amount "P" is given in order to pay the required amount "Q", with "P" greater than "Q". Rather than explicitly performing the subtraction "P" − "Q" = "C" and counting out that amount "C" in change, money is counted out starting with the successor of "Q", and continuing in the steps of the currency, until "P" is reached. Although the amount counted out must equal the result of the subtraction "P" − "Q", the subtraction was never really done and the value of "P" − "Q" is not supplied by this method.
Multiplication is the second basic operation of arithmetic. Multiplication also combines two numbers into a single number, the "product". The two original numbers are called the "multiplier" and the "multiplicand", mostly both are simply called "factors".
Multiplication may be viewed as a scaling operation. If the numbers are imagined as lying in a line, multiplication by a number, say "x", greater than 1 is the same as stretching everything away from 0 uniformly, in such a way that the number 1 itself is stretched to where "x" was. Similarly, multiplying by a number less than 1 can be imagined as squeezing towards 0. (Again, in such a way that 1 goes to the multiplicand.)
Another view on multiplication of integer numbers, extendable to rationals, but not very accessible for real numbers, is by considering it as repeated addition. So corresponds to either adding times a , or times a , giving the same result. There are different opinions on the advantageousness of these paradigmata in math education.
Multiplication is commutative and associative; further, it is distributive over addition and subtraction. The multiplicative identity is 1, since multiplying any number by 1 yields that same number. The multiplicative inverse for any number except is the reciprocal of this number, because multiplying the reciprocal of any number by the number itself yields the multiplicative identity . is the only number without a multiplicative inverse, and the result of multiplying any number and is again One says that is not contained in the multiplicative group of the numbers.
The product of "a" and "b" is written as or . When "a" or "b" are expressions not written simply with digits, it is also written by simple juxtaposition: "ab". In computer programming languages and software packages in which one can only use characters normally found on a keyboard, it is often written with an asterisk:
Algorithms implementing the operation of multiplication for various representations of numbers are by far more costly and laborious than those for addition. Those accessible for manual computation either rely on breaking down the factors to single place values and apply repeated addition, or employ tables or slide rules, thereby mapping the multiplication to addition and back. These methods are outdated and replaced by mobile devices. Computers utilize diverse sophisticated and highly optimized algorithms to implement multiplication and division for the various number formats supported in their system.
Division is essentially the inverse operation to multiplication. Division finds the "quotient" of two numbers, the "dividend" divided by the "divisor". Any dividend divided by zero is undefined. For distinct positive numbers, if the dividend is larger than the divisor, the quotient is greater than 1, otherwise it is less than 1 (a similar rule applies for negative numbers). The quotient multiplied by the divisor always yields the dividend.
Division is neither commutative nor associative. So as explained for subtraction, in modern algebra the construction of the division is discarded in favor of constructing the inverse elements with respect to multiplication, as introduced there. That is, division is a multiplication with the dividend and the reciprocal of the divisor as factors, that is
Within natural numbers there is also a different, but related notion, the Euclidean division, giving two results of "dividing" a natural (numerator) by a natural (denominator), first, a natural (quotient) and second, a natural (remainder), such that and
The fundamental theorem of arithmetic states that any integer greater than 1 has a unique prime factorization (a representation of a number as the product of prime factors), excluding the order of the factors. For example, 252 only has one prime factorization:
Euclid's Elements first introduced this theorem, and gave a partial proof (which is called Euclid's lemma). The fundamental theorem of arithmetic was first proven by Carl Friedrich Gauss.
The fundamental theorem of arithmetic is one of the reasons why 1 is not considered a prime number. Other reasons include the sieve of Eratosthenes, and the definition of a prime number itself (a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers.).
Decimal representation refers exclusively, in common use, to the written numeral system employing arabic numerals as the digits for a radix 10 ("decimal") positional notation; however, any numeral system based on powers of 10, e.g., Greek, Cyrillic, Roman, or Chinese numerals may conceptually be described as "decimal notation" or "decimal representation".
Modern methods for four fundamental operations (addition, subtraction, multiplication and division) were first devised by Brahmagupta of India. This was known during medieval Europe as "Modus Indoram" or Method of the Indians. Positional notation (also known as "place-value notation") refers to the representation or encoding of numbers using the same symbol for the different orders of magnitude (e.g., the "ones place", "tens place", "hundreds place") and, with a radix point, using those same symbols to represent fractions (e.g., the "tenths place", "hundredths place"). For example, 507.36 denotes 5 hundreds (102), plus 0 tens (101), plus 7 units (100), plus 3 tenths (10−1) plus 6 hundredths (10−2).
The concept of 0 as a number comparable to the other basic digits is essential to this notation, as is the concept of 0's use as a placeholder, and as is the definition of multiplication and addition with 0. The use of 0 as a placeholder and, therefore, the use of a positional notation is first attested to in the Jain text from India entitled the "Lokavibhâga", dated 458 AD and it was only in the early 13th century that these concepts, transmitted via the scholarship of the Arabic world, were introduced into Europe by Fibonacci using the Hindu–Arabic numeral system.
Algorism comprises all of the rules for performing arithmetic computations using this type of written numeral. For example, addition produces the sum of two arbitrary numbers. The result is calculated by the repeated addition of single digits from each number that occupies the same position, proceeding from right to left. An addition table with ten rows and ten columns displays all possible values for each sum. If an individual sum exceeds the value 9, the result is represented with two digits. The rightmost digit is the value for the current position, and the result for the subsequent addition of the digits to the left increases by the value of the second (leftmost) digit, which is always one (if not zero). This adjustment is termed a "carry" of the value 1.
The process for multiplying two arbitrary numbers is similar to the process for addition. A multiplication table with ten rows and ten columns lists the results for each pair of digits. If an individual product of a pair of digits exceeds 9, the "carry" adjustment increases the result of any subsequent multiplication from digits to the left by a value equal to the second (leftmost) digit, which is any value from (). Additional steps define the final result.
Similar techniques exist for subtraction and division.
The creation of a correct process for multiplication relies on the relationship between values of adjacent digits. The value for any single digit in a numeral depends on its position. Also, each position to the left represents a value ten times larger than the position to the right. In mathematical terms, the exponent for the radix (base) of 10 increases by 1 (to the left) or decreases by 1 (to the right). Therefore, the value for any arbitrary digit is multiplied by a value of the form 10"n" with integer "n". The list of values corresponding to all possible positions for a single digit is written
Repeated multiplication of any value in this list by 10 produces another value in the list. In mathematical terminology, this characteristic is defined as closure, and the previous list is described as closed under multiplication. It is the basis for correctly finding the results of multiplication using the previous technique. This outcome is one example of the uses of number theory.
Compound unit arithmetic is the application of arithmetic operations to mixed radix quantities such as feet and inches; gallons and pints; pounds, shillings and pence; and so on. Before decimal-based systems of money and units of measure, compound unit arithmetic was widely used in commerce and industry.
The techniques used in compound unit arithmetic were developed over many centuries and are well documented in many textbooks in many different languages. In addition to the basic arithmetic functions encountered in decimal arithmetic, compound unit arithmetic employs three more functions:
Knowledge of the relationship between the various units of measure, their multiples and their submultiples forms an essential part of compound unit arithmetic.
There are two basic approaches to compound unit arithmetic:
The addition operation is carried out from right to left; in this case, pence are processed first, then shillings followed by pounds. The numbers below the "answer line" are intermediate results.
The total in the pence column is 25. Since there are 12 pennies in a shilling, 25 is divided by 12 to give 2 with a remainder of 1. The value "1" is then written to the answer row and the value "2" carried forward to the shillings column. This operation is repeated using the values in the shillings column, with the additional step of adding the value that was carried forward from the pennies column. The intermediate total is divided by 20 as there are 20 shillings in a pound. The pound column is then processed, but as pounds are the largest unit that is being considered, no values are carried forward from the pounds column.
For the sake of simplicity, the example chosen did not have farthings.
During the 19th and 20th centuries various aids were developed to aid the manipulation of compound units, particularly in commercial applications. The most common aids were mechanical tills which were adapted in countries such as the United Kingdom to accommodate pounds, shillings, pennies and farthings and "Ready Reckoners"—books aimed at traders that catalogued the results of various routine calculations such as the percentages or multiples of various sums of money. One typical booklet that ran to 150 pages tabulated multiples "from one to ten thousand at the various prices from one farthing to one pound".
The cumbersome nature of compound unit arithmetic has been recognized for many years—in 1586, the Flemish mathematician Simon Stevin published a small pamphlet called "De Thiende" ("the tenth") in which he declared the universal introduction of decimal coinage, measures, and weights to be merely a question of time. In the modern era, many conversion programs, such as that included in the Microsoft Windows 7 operating system calculator, display compound units in a reduced decimal format rather than using an expanded format (e.g. "2.5 ft" is displayed rather than ).
Until the 19th century, "number theory" was a synonym of "arithmetic". The addressed problems were directly related to the basic operations and concerned primality, divisibility, and the solution of equations in integers, such as Fermat's last theorem. It appeared that most of these problems, although very elementary to state, are very difficult and may not be solved without very deep mathematics involving concepts and methods from many other branches of mathematics. This led to new branches of number theory such as analytic number theory, algebraic number theory, Diophantine geometry and arithmetic algebraic geometry. Wiles' proof of Fermat's Last Theorem is a typical example of the necessity of sophisticated methods, which go far beyond the classical methods of arithmetic, for solving problems that can be stated in elementary arithmetic.
Primary education in mathematics often places a strong focus on algorithms for the arithmetic of natural numbers, integers, fractions, and decimals (using the decimal place-value system). This study is sometimes known as algorism.
The difficulty and unmotivated appearance of these algorithms has long led educators to question this curriculum, advocating the early teaching of more central and intuitive mathematical ideas. One notable movement in this direction was the New Math of the 1960s and 1970s, which attempted to teach arithmetic in the spirit of axiomatic development from set theory, an echo of the prevailing trend in higher mathematics.
Also, arithmetic was used by Islamic Scholars in order to teach application of the rulings related to Zakat and Irth. This was done in a book entitled "The Best of Arithmetic" by Abd-al-Fattah-al-Dumyati.
The book begins with the foundations of mathematics and proceeds to its application in the later chapters. | https://en.wikipedia.org/wiki?curid=3118 |
Andersonville, Georgia
Andersonville is a city in Sumter County, Georgia, United States. As of the 2010 census, the city had a population of 255. It is located in the southwest part of the state, approximately southwest of Macon on the Central of Georgia railroad. During the American Civil War, it was the site of a prisoner-of-war camp, which is now Andersonville National Historic Site.
Andersonville is part of the Americus Micropolitan Statistical Area.
The hamlet of Anderson was named for John Anderson, a director of the South Western Railroad in 1853 when it was extended from Oglethorpe to Americus. It was known as Anderson Station until the US post office was established in November 1855. The government changed the name of the station from “Anderson” to “Andersonville” in order to avoid confusion with the post office in Anderson, South Carolina.
During the Civil War, the Confederate army established Camp Sumter at Andersonville to house incoming Union prisoners of war. The overcrowded Andersonville Prison was notorious for its bad conditions, and nearly 13,000 prisoners died there. After the war, Henry Wirz was convicted for war crimes related to the command of the camp. His trial was later regarded as unfair by several groups, and a monument in his honor has been erected in Andersonville by the United Daughters of the Confederacy.
The town also served as a supply depot during the war period. It included a post office, a depot, a blacksmith shop and stable, a couple of general stores, two saloons, a school, a Methodist church, and about a dozen houses. (Ben Dykes, who owned the land on which the prison was built, was both depot agent and postmaster.)
Until the establishment of the prison, the area was entirely dependent on agriculture, supported by dark reddish brown sandy loams later mapped as Greenville and Red Bay soil series. After the close of the prison and end of the war, the town continued economically dependent on agriculture, primarily the cultivation of cotton as a commodity crop.
It was not until 1968, when the large-scale mining of kaolin, bauxitic kaolin, and bauxite was begun by Mulcoa, Mullite Company of America, that the town was dramatically altered. This operation exploited of scrub oak wilderness into a massive mining and refining operation. The company now ships more than 2000 tons of refined ore from Andersonville each week.
In 1974, long-time mayor Lewis Easterlin and a group of concerned citizens decided to promote tourism in the town, redeveloping Main Street to look much as it did during the American Civil War. The city of Andersonville and the Andersonville National Historic Site, location of the prison camp, are now tourist attractions.
As of the census of 2000, there were 331 people, 124 households, and 86 families residing in the city. The population density was 254.1 people per square mile (98.3/km2). There were 142 housing units at an average density of 109.0 per square mile (42.2/km2). The racial makeup of the city was 65.26% White and 34.74% African American. Hispanic or Latino of any race were 1.21% of the population.
There were 124 households, out of which 34.7% had children under the age of 18 living with them, 46.0% were married couples living together, 17.7% had a female householder with no husband present, and 30.6% were non-families. 26.6% of all households were made up of individuals, and 10.5% had someone living alone who was 65 years of age or older. The average household size was 2.67 and the average family size was 3.21.
In the city, the population was spread out, with 27.8% under the age of 18, 9.4% from 18 to 24, 31.4% from 25 to 44, 19.3% from 45 to 64, and 12.1% who were 65 years of age or older. The median age was 36 years. For every 100 females, there were 105.6 males. For every 100 females age 18 and over, there were 97.5 males.
The median income for a household in the city was $29,107, and the median income for a family was $30,972. Males had a median income of $26,591 versus $20,000 for females. The per capita income for the city was $15,168. About 19.8% of families and 23.0% of the population were below the poverty line, including 29.3% of those under age 18 and 13.5% of those age 65 or over. | https://en.wikipedia.org/wiki?curid=3120 |
Agra Canal
The Agra Canal is an important Indian irrigation work which starts from Okhla in Delhi. The Agra canal originates from Okhla barrage, downstream of Nizamuddin bridge.
The Canal receives its water from the Yamuna River at Okhla, about 10 km to the south of New Delhi. The weir across the Yamuna was constructed of locally quarried stone. It was about 800-yard long, and rises seven-feet above the summer level of the river.
From Okhla the canal follows a route south then southeast for in the high land between the Khari-Nadi and the Yamuna and finally joins the Utanga River about below Agra. Navigable branches connect the canal with Mathura and Agra.
The canal irrigates about 1.5 lakh hectares in Agra, and Mathura in Uttar Pradesh, Faridabad in Haryana, Bharatpur in Rajasthan and also some parts of Delhi
The canal opened in 1874. In the beginning, it was available for navigation, in Delhi, erstwhile Gurgaon, Mathura and Agra Districts, and Bharatpur State. Later, navigation was stopped in 1904 and the canal has since then, been exclusively used for irrigation purposes only. At present the canal does not flow in district Gurgaon, but only in Faridabad, which was earlier a part of Gurgaon.
In recent times, Agra canal is an important landmark which separates Greater Faridabad from Faridabad.
The Agra Canal also has many places to visit along its coast. | https://en.wikipedia.org/wiki?curid=3122 |
Amakusa
, which means "Heaven's Grass," is a series of islands off the west coast of Kyushu, the southernmost of the four main islands of Japan.
The largest island of the Amakusa group is Shimoshima, which is 26.5 miles long and 13.5 miles at its widest (). It is situated at 32°20'N, 130°E, separated from the rest of Kumamoto Prefecture by the Yatsushiro Sea.
While lacking high mountains with only four peaks surpassing , the island terrain is ruggedly hilly. To cope with the lack of flat arable land, farming is carried out on a terrace system of cultivation.
Amakusa, along with the neighboring Shimabara Peninsula, became the site of the Shimabara rebellion in the 17th century, led by Christians. Following the rebellion, Kakure Kirishitan, the Christians who had survived, continued to practice their faith in secret, despite severe persecution.
Amakusa produces a little coal and pottery stone, both being used by the potters of Hirado ware and Satsuma ware. Many kilns remain on the islands today, and pottery and pottery stone are still exported.
Amakusa pottery has been recognised by the government. The retail company Muji brought out its own line of "Hakuji" home ware, which is produced out of ground translucent Amakusa stones kneaded into clay, using traditional techniques.
Hidenoshin Koyama, who built Thomas Blake Glover's House in Glover Garden, came from this island.
At present, the islands are organized as Amakusa District, Amakusa City, and Kami-amakusa City, all of which are under the administration of Kumamoto Prefecture.
The islands are served by Amakusa Airfield, located on the north end of Shimoshima. The islands are connected to the mainland by the Five Bridges of Amakusa and by ferry from Hondo and Matsushima.
There are also ferries between the islands and the neighboring prefectures of Kagoshima Prefecture and Nagasaki Prefecture. The ferry from Oniike on the north Shimoshima to Kuchinotsu, at the southern tip of the Shimabara Peninsula, is run by the Shimabara Railway and operates hourly each day. The ferry boat from Tomioka Port in Reihoku, sailing north to Mogi in Nagasaki Prefecture, is operated by Yasuda Sangyo Kisen Co. Ltd. | https://en.wikipedia.org/wiki?curid=3123 |
Afterglow
An afterglow is a broad arch of whitish or pinkish sunlight in the sky that is scattered by fine particulates, like dust, suspended in the atmosphere. An afterglow may appear above the highest clouds in the hour of fading twilight or be reflected off high snowfields in mountain regions long after sunset. The particles produce a scattering effect upon the component parts of white light. The opposite of an afterglow is a foreglow, which occurs before sunrise.
True alpenglow, which occurs long after sunset or long before sunrise, is caused by the backscattering of red sunlight by aerosols and fine dust particles low in the atmosphere. After sunset, alpenglow is an afterglow caused by the illumination of atmospheric particles by sunlight as it gets refracted and scattered through the Earth's atmosphere.
The high-energy and high-frequency light is scattered out the most, while the remaining low-energy and -frequency light reaches the observer on the horizon at twilight. The backscattering of this light further turns it pinkish to reddish. This period of time is referred to as blue hour and is widely treasured by photographers and painters.
The afterglow persists until the Earth's shadow (terminator line) overtakes the sky above the observer as night falls and the stars appear, with Venus (the second-brightest celestial object after the Moon in the night sky) visible above the horizon opposite of the Belt of Venus around the antisolar point.
After the 1883 eruption of the volcano Krakatoa, a remarkable series of red sunsets appeared worldwide. An enormous amount of exceedingly fine dust were blown to a great height by the volcano's explosion, and then globally diffused by the high atmospheric winds. Edvard Munch's painting "The Scream" possibly depicts an afterglow during this period. | https://en.wikipedia.org/wiki?curid=3124 |
Algebraic closure
In mathematics, particularly abstract algebra, an algebraic closure of a field "K" is an algebraic extension of "K" that is algebraically closed. It is one of many closures in mathematics.
Using Zorn's lemma or the weaker ultrafilter lemma, it can be shown that every field has an algebraic closure, and that the algebraic closure of a field "K" is unique up to an isomorphism that fixes every member of "K". Because of this essential uniqueness, we often speak of "the" algebraic closure of "K", rather than "an" algebraic closure of "K".
The algebraic closure of a field "K" can be thought of as the largest algebraic extension of "K".
To see this, note that if "L" is any algebraic extension of "K", then the algebraic closure of "L" is also an algebraic closure of "K", and so "L" is contained within the algebraic closure of "K".
The algebraic closure of "K" is also the smallest algebraically closed field containing "K",
because if "M" is any algebraically closed field containing "K", then the elements of "M" that are algebraic over "K" form an algebraic closure of "K".
The algebraic closure of a field "K" has the same cardinality as "K" if "K" is infinite, and is countably infinite if "K" is finite.
Let formula_1 be the set of all monic irreducible polynomials in "K"["x"].
For each formula_2, introduce new variables formula_3 where formula_4.
Let "R" be the polynomial ring over "K" generated by formula_5 for all formula_6 and all formula_7. Write
with formula_9.
Let "I" be the ideal in "R" generated by the formula_10. Since "I" is strictly smaller than "R",
Zorn's lemma implies that there exists a maximal ideal "M" in "R" that contains "I".
The field "K"1="R"/"M" has the property that every polynomial formula_11 with coefficients in "K" splits as the product of formula_12 and hence has all roots in "K"1. In the same way, an extension "K"2 of "K"1 can be constructed, etc. The union of all these extensions is the algebraic closure of "K", because any polynomial with coefficients in this new field has its coefficients in some "K"n with sufficiently large "n", and then its roots are in "K"n+1, and hence in the union itself.
It can be shown along the same lines that for any subset "S" of "K"["x"], there exists a splitting field of "S" over "K".
An algebraic closure "Kalg" of "K" contains a unique separable extension "Ksep" of "K" containing all (algebraic) separable extensions of "K" within "Kalg". This subextension is called a separable closure of "K". Since a separable extension of a separable extension is again separable, there are no finite separable extensions of "Ksep", of degree > 1. Saying this another way, "K" is contained in a "separably-closed" algebraic extension field. It is unique (up to isomorphism).
The separable closure is the full algebraic closure if and only if "K" is a perfect field. For example, if "K" is a field of characteristic "p" and if "X" is transcendental over "K", formula_13 is a non-separable algebraic field extension.
In general, the absolute Galois group of "K" is the Galois group of "Ksep" over "K". For example, if formula_14, then its separable closure isformula_15 | https://en.wikipedia.org/wiki?curid=3129 |
Advanced Power Management
Advanced power management (APM) is an API developed by Intel and Microsoft and released in 1992 which enables an operating system running an IBM-compatible personal computer to work with the BIOS (part of the computer's firmware) to achieve power management.
Revision 1.2 was the last version of the APM specification, released in 1996. ACPI is intended as the successor to APM. Microsoft dropped support for APM in Windows Vista. The Linux kernel still mostly supports APM, though support for APM CPU idle was dropped in version 3.0.
APM uses a layered approach to manage devices. APM-aware applications (which include device drivers) talk to an OS-specific APM driver. This driver communicates to the APM-aware BIOS, which controls the hardware. There is the ability to opt out of APM control on a device-by-device basis, which can be used if a driver wants to communicate directly with a hardware device.
Communication occurs both ways; power management events are sent from the BIOS to the APM driver, and the APM driver sends information and requests to the BIOS via function calls. In this way the APM driver is an intermediary between the BIOS and the operating system.
Power management happens in two ways; through the above-mentioned function calls from the APM driver to the BIOS requesting power state changes, and automatically based on device activity.
There are 12 power events (such as standby, suspend and resume requests, and low battery notifications), plus OEM-defined events, that can be sent from the APM BIOS to the operating system. The APM driver regularly polls for event change notifications.
Power Management Events:
Power management functions:
There are 21 APM function calls defined that the APM driver can use to query power management statuses, or request power state transitions. Example function calls include letting the BIOS know about current CPU usage (the BIOS may respond to such a call by placing the CPU in a low-power state, or returning it to its full-power state), retrieving the current power state of a device, or requesting a power state change.
The APM specification defines system power states and device power states.
APM defines five power states for the computer system:
APM also defines power states that APM-aware hardware can implement. There is no requirement that an APM-aware device implement all states.
The four states are:
The CPU core (defined in APM as the CPU clock, cache, system bus and system timers) is treated specially in APM, as it is the last device to be powered down, and the first device to be powered back up. The CPU core is always controlled through the APM BIOS (there is no option to control it through a driver). Drivers can use APM function calls to notify the BIOS about CPU usage, but it is up to the BIOS to act on this information; a driver cannot directly tell the CPU to go into a power saving state.
The ATA specification defines APM provisions for hard drives via the subcommand , which specifies a trade-off between spin-down frequency and always-on performance. Unlike the BIOS-side APM, the ATA APM has never been deprecated. | https://en.wikipedia.org/wiki?curid=3130 |
Adolphe Sax
Antoine-Joseph "Adolphe" Sax (; 6 November 1814 – 7 February 1894) was a Belgian inventor and musician who created the saxophone in the early 1840s, patenting it in 1846. He also invented the saxotromba, saxhorn and saxtuba. He played the flute and clarinet.
Antoine-Joseph Sax was born on 6 November 1814, in Dinant, in what is now Belgium, to Charles-Joseph Sax and his wife Marie-Joseph (Masson). While his given name was Antoine-Joseph, he was referred to as Adolphe from childhood. His father and mother were instrument designers themselves, who made several changes to the design of the French horn. Adolphe began to make his own instruments at an early age, entering two of his flutes and a clarinet into a competition at the age of 15. He subsequently studied performance on those two instruments as well as voice at the Royal Conservatory of Brussels.
Sax faced many brushes with death. Over the course of his childhood, he:
His mother once said that "he's a child condemned to misfortune; he won't live." His neighbors called him "little Sax, the ghost".
After leaving the Royal Conservatory of Brussels, Sax began to experiment with new instrument designs, while his parents continued to make conventional instruments to bring in money. Adolphe's first important invention was an improvement of the bass clarinet design, which he patented at the age of 24. Sax relocated permanently to Paris in 1842 and began working on a new set of instruments. Hector Berlioz was so enamoured of them that he arranged in February 1844 for one of his pieces to be played entirely on Sax's new instruments. These were valved bugles, and although he had not invented the instrument itself, his examples were much more successful than those of his rivals and became known as saxhorns. They came in seven different sizes, and paved the way for the creation of the flugelhorn. Today, saxhorns are sometimes used in concert bands, marching bands and orchestras. The saxhorn also laid the groundwork for the modern euphonium.
Sax also developed the "saxotromba" family, valved brass instruments with narrower bore than the saxhorns, in 1845, though they survived only briefly.
The use of saxhorns spread rapidly. The saxhorn valves were accepted as state-of-the-art in their time and remain largely unchanged today. The advances made by Adolphe Sax were soon followed by the British brass band movement which exclusively adopted the saxhorn family of instruments. The Jedforest Instrumental Band formed in 1854 and The Hawick Saxhorn Band formed in 1855, within the Scottish Borders, a decade after saxhorn models became available.
The period around 1840 saw Sax inventing the "clarinette-bourdon", an early unsuccessful design of contrabass clarinet. Around this time he also developed the instrument for which he is best known: the saxophone, which he patented on 28 June 1846. The saxophone was invented for use in both orchestras and military bands. By 1846 Sax had designed (on paper at least) a full range of saxophones (from sopranino to subcontrabass). Composer Hector Berlioz wrote approvingly of the new instrument in 1842, but despite his support, saxophones never became standard orchestral instruments. However, their ability to play technical passages easily like woodwinds and also project loudly like brass instruments led them to be included in military bands in France and elsewhere. The saxophone was Sax's signature accomplishment and created his reputation more than any other. This helped secure him a job teaching at the Paris Conservatory in 1857.
Sax continued to make instruments later in life and presided over the new saxophone program at the Paris Conservatory. Rival instrument makers both attacked the legitimacy of his patents and were sued by Sax for patent infringement. The legal back-and-forth continued for over 20 years. He was driven into bankruptcy three times: in 1852, 1873, and 1877.
Sax suffered from lip cancer between 1853 and 1858 but made a full recovery. In 1894, Sax died in complete poverty in Paris and was interred in section 5 (Avenue de Montebello) at the Cimetière de Montmartre in Paris.
In his birthplace Dinant in Belgium the Mr Sax's House is dedicated to his life and saxophones. | https://en.wikipedia.org/wiki?curid=3132 |
Aspirated consonant
In phonetics, aspiration is the strong burst of breath that accompanies either the release or, in the case of preaspiration, the closure of some obstruents. In English, aspirated consonants are allophones in complementary distribution with their unaspirated counterparts, but in some other languages, notably most Indian and East Asian languages, the difference is contrastive.
To feel or see the difference between aspirated and unaspirated sounds, one can put a hand or a lit candle in front of one's mouth, and say "spin" and then "pin" . One should either feel a puff of air or see a flicker of the candle flame with "pin" that one does not get with "spin".
In the International Phonetic Alphabet (IPA), aspirated consonants are written using the symbols for voiceless consonants followed by the aspiration modifier letter , a superscript form of the symbol for the voiceless glottal fricative . For instance, represents the voiceless bilabial stop, and represents the aspirated bilabial stop.
Voiced consonants are seldom actually aspirated. Symbols for voiced consonants followed by , such as , typically represent consonants with murmured voiced release (see below). In the grammatical tradition of Sanskrit, aspirated consonants are called voiceless aspirated, and breathy-voiced consonants are called voiced aspirated.
There are no dedicated IPA symbols for degrees of aspiration and typically only two degrees are marked: unaspirated and aspirated . An old symbol for light aspiration was , but this is now obsolete. The aspiration modifier letter may be doubled to indicate especially strong or long aspiration. Hence, the two degrees of aspiration in Korean stops are sometimes transcribed or and , but they are usually transcribed and , with the details of voice onset time given numerically.
Preaspirated consonants are marked by placing the aspiration modifier letter before the consonant symbol: represents the preaspirated bilabial stop.
Unaspirated or tenuis consonants are occasionally marked with the modifier letter for unaspiration , a superscript equals sign: . Usually, however, unaspirated consonants are left unmarked: .
Voiceless consonants are produced with the vocal folds open (spread) and not vibrating, and voiced consonants are produced when the vocal folds are fractionally closed and vibrating (modal voice). Voiceless aspiration occurs when the vocal folds remain open after a consonant is released. An easy way to measure this is by noting the consonant's voice onset time, as the voicing of a following vowel cannot begin until the vocal folds close.
In some languages, such as Navajo, aspiration of stops tends to be phonetically realised as voiceless velar airflow; aspiration of affricates is realised as an extended length of the frication.
Aspirated consonants are not always followed by vowels or other voiced sounds. For example, in Eastern Armenian, aspiration is contrastive even word-finally, and aspirated consonants occur in consonant clusters. In Wahgi, consonants are aspirated only when they are in final position.
The degree of aspiration varies: the voice onset time of aspirated stops is longer or shorter depending on the language or the place of articulation.
Armenian and Cantonese have aspiration that lasts about as long as English aspirated stops, in addition to unaspirated stops. Korean has lightly-aspirated stops that fall between the Armenian and Cantonese unaspirated and aspirated stops as well as strongly-aspirated stops whose aspiration lasts longer than that of Armenian or Cantonese. (See voice onset time.)
Aspiration varies with place of articulation. The Spanish voiceless stops have voice onset times (VOTs) of about 5, 10, and 30 milliseconds, and English aspirated have VOTs of about 60, 70, and 80 ms. Voice onset time in Korean has been measured at 20, 25, and 50 ms for and 90, 95, and 125 for .
When aspirated consonants are doubled or geminated, the stop is held longer and then has an aspirated release. An aspirated affricate consists of a stop, fricative, and aspirated release. A doubled aspirated affricate has a longer hold in the stop portion and then has a release consisting of the fricative and aspiration.
Icelandic and Faroese have consonants with preaspiration , and some scholars interpret them as consonant clusters as well. In Icelandic, preaspirated stops contrast with double stops and single stops:
Preaspiration is also a feature of Scottish Gaelic:
Preaspirated stops also occur in most Sami languages. For example, in Northern Sami, the unvoiced stop and affricate phonemes , , , , are pronounced preaspirated (, , , ) in medial or final position.
Although most aspirated obstruents in the world's languages are stops and affricates, aspirated fricatives such as , or have been documented in Korean, though these are allophones of other phonemes. Similarly, aspirated fricatives and even aspirated nasals, approximants, and trills occur in a few Tibeto-Burman languages, in some Oto-Manguean languages, in the Hmongic language Hmu, and in the Siouan language Ofo. Some languages, such as Choni Tibetan, have as many as four contrastive aspirated fricatives , and .
True aspirated voiced consonants, as opposed to murmured (breathy-voice) consonants such as the that are common among the languages of India, are extremely rare. They have been documented in Kelabit.
Aspiration has varying significance in different languages. It is either allophonic or phonemic, and may be analyzed as an underlying consonant cluster.
In some languages, such as English, aspiration is allophonic. Stops are distinguished primarily by voicing, and voiceless stops are sometimes aspirated, while voiced stops are usually unaspirated.
English voiceless stops are aspirated for most native speakers when they are word-initial or begin a stressed syllable.
For instance, "distend" has unaspirated since it is not analyzed as two morphemes, but "distaste" has an aspirated middle because it is analyzed as "dis-" + "taste" and the word "taste" has an aspirated initial "t".
Word-final voiceless stops are sometimes aspirated.
Voiceless stops in Pashto are slightly aspirated prevocalically in a stressed syllable.
In many languages, such as Armenian, Korean, Lakota, Thai, Indo-Aryan languages, Dravidian languages, Icelandic, Faroese, Ancient Greek, and the varieties of Chinese, tenuis and aspirated consonants are phonemic. Unaspirated consonants like and aspirated consonants like are separate phonemes, and words are distinguished by whether they have one or the other.
Alemannic German dialects have unaspirated as well as aspirated ; the latter series are usually viewed as consonant clusters.
In Danish and most southern varieties of German, the lenis consonants transcribed for historical reasons as are distinguished from their fortis counterparts , mainly in their lack of aspiration.
French, Standard Dutch, Afrikaans, Tamil, Finnish, Portuguese, Italian, Spanish, Russian, Polish, Latvian and Modern Greek are languages that do not have phonemic aspirated consonants.
Standard Chinese (Mandarin) has stops and affricates distinguished by aspiration: for instance, , . In pinyin, tenuis stops are written with letters that represent voiced consonants in English, and aspirated stops with letters that represent voiceless consonants. Thus "d" represents , and "t" represents .
Wu Chinese and Southern Min has a three-way distinction in stops and affricates: . In addition to aspirated and unaspirated consonants, there is a series of "muddy consonants", like . These are pronounced with slack or breathy voice: that is, they are weakly voiced. Muddy consonants as initial cause a syllable to be pronounced with low pitch or "light" (陽 "yáng") tone.
Many Indo-Aryan languages have aspirated stops. Sanskrit, Hindustani, Bengali, Marathi, and Gujarati have a four-way distinction in stops: voiceless, aspirated, voiced, and breathy-voiced or voiced aspirated, such as . Punjabi has lost breathy-voiced consonants, which resulted in a tone system, and therefore has a distinction between voiceless, aspirated, and voiced: .
Some of the Dravidian languages, such as Telugu, Malayalam, and Kannada, have a distinction between voiced and voiceless, aspirated and unaspirated only in loanwords from Indo-Aryan languages. In native Dravidian words, there is no distinction between these categories and stops are underspecified for voicing and aspiration.
Most dialects of Armenian have aspirated stops, and some have breathy-voiced stops.
Classical and Eastern Armenian have a three-way distinction between voiceless, aspirated, and voiced, such as .
Western Armenian has a two-way distinction between aspirated and voiced: . Western Armenian aspirated corresponds to Eastern Armenian aspirated and voiced , and Western voiced corresponds to Eastern voiceless .
Some forms of Greek before the Koine Greek period are reconstructed as having aspirated stops. The Classical Attic dialect of Ancient Greek had a three-way distinction in stops like Eastern Armenian: . These series were called , , ("psilá, daséa, mésa") "smooth, rough, intermediate", respectively, by Koine Greek grammarians.
There were aspirated stops at three places of articulation: labial, coronal, and velar . Earlier Greek, represented by Mycenaean Greek, likely had a labialized velar aspirated stop , which later became labial, coronal, or velar depending on dialect and phonetic environment.
The other Ancient Greek dialects, Ionic, Doric, Aeolic, and Arcadocypriot, likely had the same three-way distinction at one point, but Doric seems to have had a fricative in place of in the Classical period, and the Ionic and Aeolic dialects sometimes lost aspiration (psilosis).
Later, during the Koine Greek period, the aspirated and voiced stops of Attic Greek lenited to voiceless and voiced fricatives, yielding in Medieval and Modern Greek. Cypriot Greek is notable for aspirating its inherited (and developed across word-boundaries) voiceless geminate stops, yielding the series /pʰː tʰː cʰː kʰː/.
The term "aspiration" sometimes refers to the sound change of debuccalization, in which a consonant is lenited (weakened) to become a glottal stop or fricative .
So-called voiced aspirated consonants are nearly always pronounced instead with breathy voice, a type of phonation or vibration of the vocal folds. The modifier letter after a voiced consonant actually represents a breathy-voiced or murmured dental stop, as with the "voiced aspirated" bilabial stop in the Indo-Aryan languages. This consonant is therefore more accurately transcribed as , with the diacritic for breathy voice, or with the modifier letter , a superscript form of the symbol for the voiced glottal fricative .
Some linguists restrict the double-dot subscript to murmured sonorants, such as vowels and nasals, which are murmured throughout their duration, and use the superscript hook-aitch for the breathy-voiced release of obstruents. | https://en.wikipedia.org/wiki?curid=3134 |
Arteriovenous malformation
Arteriovenous malformation is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system (usually cerebral AVM), but can appear in any location. Although many AVMs are asymptomatic, they can cause intense pain or bleeding or lead to other serious medical problems.
AVMs are usually congenital and belong to the RASopathies.
The genetic transmission patterns of AVMs are incomplete, but there are known genetic mutations (for instance in the epithelial line, tumor suppressor PTEN gene) which can lead to an increased occurrence throughout the body.
Symptoms of AVM vary according to the location of the malformation. Roughly 88% of people with an AVM are asymptomatic; often the malformation is discovered as part of an autopsy or during treatment of an unrelated disorder (called in medicine an "incidental finding"); in rare cases, its expansion or a micro-bleed from an AVM in the brain can cause epilepsy, neurological deficit, or pain.
The most general symptoms of a cerebral AVM include headaches and epileptic seizures, with more specific symptoms occurring that normally depend on the location of the malformation and the individual. Such possible symptoms include:
Cerebral AVMs may present themselves in a number of different ways:
Pulmonary arteriovenous malformations are abnormal communications between the veins and arteries of the pulmonary circulation, leading to a right-to-left blood shunt.
They have no symptoms in up to 29% of all cases, however they can give rise to serious complications including hemorrhage, and infection. They are most commonly associated with hereditary hemorrhagic telangiectasia.
Can occur due to autosomal dominant diseases, such as hereditary hemorrhagic telangiectasia.
Arteries and veins are part of the vascular system. Arteries carry blood away from the heart to the lungs or the rest of the body, where the blood passes through capillaries, and veins return the blood to the heart. An AVM interferes with this process by forming a direct connection of the arteries and veins. AVMs can cause intense pain and lead to serious medical problems. Although AVMs are often associated with the brain and spinal cord, they can develop in any part of the body.
Normally, the arteries in the vascular system carry oxygen-rich blood, except in the case of the pulmonary artery. Structurally, arteries divide and sub-divide repeatedly, eventually forming a sponge-like capillary bed. Blood moves through the capillaries, giving up oxygen and taking up waste products, including , from the surrounding cells. Capillaries in turn successively join together to form veins that carry blood away. The heart acts to pump blood through arteries and uptake the venous blood.
As an AVM lacks the dampening effect of capillaries on the blood flow, the AVM can get progressively larger over time as the amount of blood flowing through it increases, forcing the heart to work harder to keep up with the extra blood flow. It also causes the surrounding area to be deprived of the functions of the capillaries—removal of and delivery of nutrients to the cells. The resulting tangle of blood vessels, often called a "nidus" (Latin for "nest"), has no capillaries. It can be extremely fragile and prone to bleeding because of the abnormally direct connections between high-pressure arteries and low-pressure veins. The resultant sign, audible via stethoscope, is a rhythmic, whooshing sound caused by excessively rapid blood flow through the arteries and veins. It has been given the term "bruit", French for noise. On some occasions, a patient with a brain AVM may become aware of the noise, which can compromise hearing and interfere with sleep in addition to causing psychological distress.
AVMs are diagnosed primarily by the following imaging methods:
AVMs can occur in various parts of the body:
AVMs may occur in isolation or as a part of another disease (for example, Von Hippel-Lindau disease or hereditary hemorrhagic telangiectasia).
AVMs have been shown to be associated with aortic stenosis.
Bleeding from an AVM can be relatively mild or devastating. It can cause severe and less often fatal strokes. If a cerebral AVM is detected before a stroke occurs, usually the arteries feeding blood into the nidus can be closed off to avert the danger. However, interventional therapy may also be relatively risky.
Treatment for brain AVMs can be symptomatic, and patients should be followed by a neurologist for any seizures, headaches, or focal neurologic deficits. AVM-specific treatment may also involve endovascular embolization, neurosurgery or radiosurgery.
Embolization, that is, cutting off the blood supply to the AVM with coils, particles, acrylates, or polymers introduced by a radiographically guided catheter, may be used in addition to neurosurgery or radiosurgery, but is rarely successful in isolation except in smaller AVMs. Gamma knife may also be used.
Treatment of lung AVMs is typically performed with endovascular embolization alone, which is considered the standard of care.
The estimated detection rate of AVM in the US general population is 1.4/100,000 per year. This is approximately one fifth to one seventh the incidence of intracranial aneurysms. An estimated 300,000 Americans have AVMs, of whom 12% (approximately 36,000) will exhibit symptoms of greatly varying severity.
Emmanuel, Luschka, and Virchow first described arteriovenous malformations in the mid-1800s. Olivecrona performed the first surgical excision of an intracranial AVM in 1932.
Despite many years of research, the central question of whether to treat AVMs has not been answered. All treatments, whether involving surgery, radiation, or drugs, have risks and side-effects. Therefore, it might be better in some cases to avoid treatment altogether and simply accept a small risk of coming to harm from the AVM itself. This question is currently being addressed in clinical trials. | https://en.wikipedia.org/wiki?curid=3135 |
Atlanta
Atlanta () is the capital and most populous city of the U.S. state of Georgia. With an estimated 2019 population of 506,811, it is also the 37th most populous city in the United States. The city serves as the cultural and economic center of the Atlanta metropolitan area, home to more than 6 million people and the ninth-largest metropolitan area in the nation. Atlanta is the seat of Fulton County, the most populous county in Georgia. Portions of the city extend eastward into neighboring DeKalb County. The city is situated among the foothills of the Appalachian Mountains and has one of the highest elevations among major cities east of the Mississippi River.
Atlanta was originally founded as the terminus of a major state-sponsored railroad. With rapid expansion, however, it soon became the convergence point among multiple railroads, spurring its rapid growth. The city's name derives from that of the Western and Atlantic Railroad's local depot, signifying the town's growing reputation as a transportation hub. During the American Civil War, the city was almost entirely burned to the ground in General William T. Sherman's famous March to the Sea. However, the city rose from its ashes and quickly became a national center of commerce and the unofficial capital of the "New South". During the 1950s and 1960s, Atlanta became a major organizing center of the civil rights movement, with Dr. Martin Luther King Jr., Ralph David Abernathy, and many other locals playing major roles in the movement's leadership. During the modern era, Atlanta has attained international prominence as a major air transportation hub, with Hartsfield–Jackson Atlanta International Airport being the world's busiest airport by passenger traffic since 1998.
It ranks in the top twenty among world cities and 10th in the nation with a gross domestic product (GDP) of $385 billion. Atlanta's economy is considered diverse, with dominant sectors that include aerospace, transportation, logistics, professional and business services, media operations, medical services, and information technology. Atlanta has topographic features that include rolling hills and dense tree coverage, earning it the nickname of "the city in a forest". Revitalization of Atlanta's neighborhoods, initially spurred by the 1996 Summer Olympics, has intensified in the 21st century, altering the city's demographics, politics, aesthetics, and culture.
For thousands of years prior to the arrival of European settlers in north Georgia, the indigenous Creek people and their ancestors inhabited the area. Standing Peachtree, a Creek village where Peachtree Creek flows into the Chattahoochee River, was the closest Native American settlement to what is now Atlanta. Through the early nineteenth century, European Americans systematically encroached on the Creek of northern Georgia, forcing them out of the area from 1802 to 1825. The Creek were forced to leave the area in 1821, under Indian Removal by the federal government, and European American settlers arrived the following year.
In 1836, the Georgia General Assembly voted to build the Western and Atlantic Railroad in order to provide a link between the port of Savannah and the Midwest. The initial route was to run southward from Chattanooga to a terminus east of the Chattahoochee River, which would be linked to Savannah. After engineers surveyed various possible locations for the terminus, the "zero milepost" was driven into the ground in what is now Five Points. A year later, the area around the milepost had developed into a settlement, first known as "Terminus", and later "Thrasherville", after a local merchant who built homes and a general store in the area. By 1842, the town had six buildings and 30 residents and was renamed "Marthasville" to honor Governor Wilson Lumpkin's daughter Martha. Later, J. Edgar Thomson, Chief Engineer of the Georgia Railroad, suggested the town be renamed "Atlanta". The residents approved, and the town was incorporated as Atlanta on December 29, 1847.
By 1860, Atlanta's population had grown to 9,554. During the American Civil War, the nexus of multiple railroads in Atlanta made the city a strategic hub for the distribution of military supplies.
In 1864, the Union Army moved southward following the capture of Chattanooga and began its invasion of north Georgia. The region surrounding Atlanta was the location of several major army battles, culminating with the Battle of Atlanta and a four-month-long siege of the city by the Union Army under the command of General William Tecumseh Sherman. On September 1, 1864, Confederate General John Bell Hood made the decision to retreat from Atlanta, and he ordered the destruction of all public buildings and possible assets that could be of use to the Union Army. On the next day, Mayor James Calhoun surrendered Atlanta to the Union Army, and on September 7, Sherman ordered the city's civilian population to evacuate. On November 11, 1864, Sherman prepared for the Union Army's March to the Sea by ordering the destruction of Atlanta's remaining military assets.
After the Civil War ended in 1865, Atlanta was gradually rebuilt. The work attracted many new residents. Due to the city's superior rail transportation network, the state capital was moved from Milledgeville to Atlanta in 1868. In the 1880 Census, Atlanta had surpassed Savannah as Georgia's largest city.
Beginning in the 1880s, Henry W. Grady, the editor of the "Atlanta Constitution" newspaper, promoted Atlanta to potential investors as a city of the "New South" that would be based upon a modern economy and less reliant on agriculture. By 1885, the founding of the Georgia School of Technology (now Georgia Tech) and the Atlanta University Center, a historically black college made up of units for men and women, had established Atlanta as a center for higher education. In 1895, Atlanta hosted the Cotton States and International Exposition, which attracted nearly 800,000 attendees and successfully promoted the New South's development to the world.
During the first decades of the 20th century, Atlanta enjoyed a period of unprecedented growth. In three decades' time, Atlanta's population tripled as the city limits expanded to include nearby streetcar suburbs. The city's skyline grew taller with the construction of the Equitable, Flatiron, Empire, and Candler buildings. Sweet Auburn emerged as a center of black commerce. The period was also marked by strife and tragedy. Increased racial tensions led to the Atlanta Race Riot of 1906, when whites attacked blacks, leaving at least 27 people dead and over 70 injured, with extensive damage in black neighborhoods. In 1913, Leo Frank, a Jewish-American factory superintendent, was convicted of the murder of a 13-year-old girl in a highly publicized trial. He was sentenced to death but the governor commuted his sentence to life. An enraged and organized lynch mob took him from jail in 1915 and hanged him in Marietta. The Jewish community in Atlanta and across the country were horrified. On May 21, 1917, the Great Atlanta Fire destroyed 1,938 buildings in what is now the Old Fourth Ward, resulting in one fatality and the displacement of 10,000 people.
On December 15, 1939, Atlanta hosted the premiere of "Gone with the Wind", the epic film based on the best-selling novel by Atlanta's Margaret Mitchell. The gala event at Loew's Grand Theatre was attended by the film's legendary producer, David O. Selznick, and the film's stars Clark Gable, Vivien Leigh, and Olivia de Havilland, but Oscar winner Hattie McDaniel, an African-American actress, was barred from the event due to racial segregation laws.
Atlanta played a vital role in the Allied effort during World War II due to the city's war-related manufacturing companies, railroad network and military bases. The defense industries attracted thousands of new residents and generated revenues, resulting in rapid population and economic growth. In the 1950s, the city's newly constructed highway system, supported by federal subsidies, allowed middle class Atlantans the ability to relocate to the suburbs. As a result, the city began to make up an ever-smaller proportion of the metropolitan area's population.
African-American veterans returned from World War II seeking full rights in their country and began heightened activism. In exchange for support by that portion of the black community that could vote, in 1948 the mayor ordered the hiring of the first eight African-American police officers in the city. In the 1960s, Atlanta became a major organizing center of the civil rights movement, with Dr. Martin Luther King, Jr., Ralph David Abernathy, and students from Atlanta's historically black colleges and universities playing major roles in the movement's leadership. While Atlanta in the postwar years had relatively minimal racial strife compared to other cities, blacks were limited by discrimination, segregation, and continued disenfranchisement of most voters. In 1961, the city attempted to thwart blockbusting by realtors by erecting road barriers in Cascade Heights, countering the efforts of civic and business leaders to foster Atlanta as the "city too busy to hate".
Desegregation of the public sphere came in stages, with public transportation desegregated by 1959, the restaurant at Rich's department store by 1961, movie theaters by 1963, and public schools by 1973 (nearly 20 years after the US Supreme Court ruled that segregated public schools were unconstitutional). In the private sphere, The Westminster Schools desegregated in 1967.
In 1960, whites comprised 61.7% of the city's population. During the 1950s–70s, suburbanization and white flight from urban areas led to a significant demographic shift. By 1970, African Americans were the majority of the city's population and exercised their recently enforced voting rights and political influence by electing Atlanta's first black mayor, Maynard Jackson, in 1973. Under Mayor Jackson's tenure, Atlanta's airport was modernized, strengthening the city's role as a transportation center. The opening of the Georgia World Congress Center in 1976 heralded Atlanta's rise as a convention city. Construction of the city's subway system began in 1975, with rail service commencing in 1979. Despite these improvements, Atlanta lost more than 100,000 residents between 1970 and 1990, over 20% of its population. At the same time, it developed new office space after attracting numerous corporations, with an increasing portion of workers from northern areas.
Atlanta was selected as the site for the 1996 Summer Olympic Games. Following the announcement, the city government undertook several major construction projects to improve Atlanta's parks, sporting venues, and transportation infrastructure; however, for the first time, none of the $1.7 billion cost of the games was governmentally funded. While the games experienced transportation and accommodation problems and, despite extra security precautions, there was the Centennial Olympic Park bombing, the spectacle was a watershed event in Atlanta's history. For the first time in Olympic history, every one of the record 197 national Olympic committees invited to compete sent athletes, sending more than 10,000 contestants participating in a record 271 events. The related projects such as Atlanta's Olympic Legacy Program and civic effort initiated a fundamental transformation of the city in the following decade.
During the 2000s, Atlanta underwent a profound physical, cultural, and demographic transformation. As some of the black middle and upper classes also began to move to the suburbs, a booming economy drew numerous new migrants from other areas of the country, who contributed to changes in the city's demographics. African Americans made up a decreasing portion of the population, from a high of 67% in 1990 to 54% in 2010. From 2000 to 2010, Atlanta gained 22,763 white residents, 5,142 Asian residents, and 3,095 Hispanic residents, while the city's black population decreased by 31,678. Much of the city's demographic change during the decade was driven by young, college-educated professionals: from 2000 to 2009, the three-mile radius surrounding Downtown Atlanta gained 9,722 residents aged 25 to 34 and holding at least a four-year degree, an increase of 61%. This was similar to the tendency in other cities for young, college educated, single or married couples to live in downtown areas.
Between the mid-1990s and 2010, stimulated by funding from the HOPE VI program and under leadership of CEO Renee Lewis Glover (1994–2013), the Atlanta Housing Authority demolished nearly all of its public housing, a total of 17,000 units and about 10% of all housing units in the city. After reserving 2,000 units mostly for elderly, the AHA allowed redevelopment of the sites for mixed-use and mixed-income, higher density developments, with 40% of the units to be reserved for affordable housing. Two-fifths of previous public housing residents attained new housing in such units; the remainder received vouchers to be used at other units, including in suburbs. At the same time, in an effort to change the culture of those receiving subsidized housing, the AHA imposed a requirement for such residents to work (or be enrolled in a genuine, limited-time training program). It is virtually the only housing authority to have created this requirement. To prevent problems, the AHA also gave authority to management of the mixed-income or voucher units to evict tenants who did not comply with the work requirement or who caused behavior problems.
In 2005, the city approved the $2.8 billion BeltLine project. It was intended to convert a disused 22-mile freight railroad loop that surrounds the central city into an art-filled multi-use trail and light rail transit line, which would increase the city's park space by 40%. The project stimulated retail and residential development along the loop.
Atlanta's cultural offerings expanded during the 2000s: the High Museum of Art doubled in size; the Alliance Theatre won a Tony Award; and art galleries were established on the once-industrial Westside. The city of Atlanta was the subject of a massive cyberattack which began in March 2018.
Atlanta encompasses , of which is land and is water. The city is situated among the foothills of the Appalachian Mountains. At above mean sea level, Atlanta has one of the highest elevations among major cities east of the Mississippi River. Atlanta straddles the Eastern Continental Divide. Rainwater that falls on the south and east side of the divide flows into the Atlantic Ocean, while rainwater on the north and west side of the divide flows into the Gulf of Mexico. Atlanta developed on a ridge south of the Chattahoochee River, which is part of the ACF River Basin. The river borders the far northwestern edge of the city, and much of its natural habitat has been preserved, in part by the Chattahoochee River National Recreation Area.
Most of Atlanta was burned during the Civil War, depleting the city of a large stock of its historic architecture. Yet architecturally, the city had never been traditionally "southern" because Atlanta originated as a railroad town, rather than a southern seaport dominated by the planter class, such as Savannah or Charleston. Because of its later development, many of the city's landmarks share architectural characteristics with buildings in the Northeast or Midwest, as they were designed at a time of shared national architectural styles.
During the late twentieth century, Atlanta embraced the global trend of modern architecture, especially for commercial and institutional structures. Examples include the State of Georgia Building built in 1966, and the Georgia-Pacific Tower in 1982. Many of the most notable examples from this period we designed by world renowned Atlanta architect John Portman. Most of the buildings that define the downtown skyline were designed by Portman during this period, including the Westin Peachtree Plaza and the Atlanta Marriott Marquis. In the latter half of the 1980s, Atlanta became one of the early homes of postmodern buildings that reintroduced classical elements to their designs. Many of Atlanta's tallest skyscrapers were built in this period and style, displaying tapering spires or otherwise ornamented crowns, such as One Atlantic Center (1987), 191 Peachtree Tower (1991), and the Four Seasons Hotel Atlanta (1992). Also completed during the era is the Portman-designed Bank of America Plaza built in 1992. At , it is the tallest building in the city and the 14th-tallest in the United States.
The city's embrace of modern architecture has often translated into an ambivalent approach toward historic preservation, leading to the destruction of many notable architectural landmarks. These include the Equitable Building (1892–1971), Terminal Station (1905–1972), and the Carnegie Library (1902–1977). In the mid-1970s, the Fox Theatre, now a cultural icon of the city, would have met the same fate if not for a grassroots effort to save it. More recently, preservationists may have made some inroads. For example, in 2016 activists convinced the Atlanta City Council not to demolish the Atlanta-Fulton Central Library, the last building designed by noted architect Marcel Breuer.
Atlanta is divided into 242 officially defined neighborhoods. The city contains three major high-rise districts, which form a north–south axis along Peachtree: Downtown, Midtown, and Buckhead. Surrounding these high-density districts are leafy, low-density neighborhoods, most of which are dominated by single-family homes.
Downtown Atlanta contains the most office space in the metro area, much of it occupied by government entities. Downtown is home to the city's sporting venues and many of its tourist attractions. Midtown Atlanta is the city's second-largest business district, containing the offices of many of the region's law firms. Midtown is known for its art institutions, cultural attractions, institutions of higher education, and dense form. Buckhead, the city's uptown district, is north of Downtown and the city's third-largest business district. The district is marked by an urbanized core along Peachtree Road, surrounded by suburban single-family neighborhoods situated among woods and rolling hills.
Surrounding Atlanta's three high-rise districts are the city's low- and medium-density neighborhoods, where the craftsman bungalow single-family home is dominant. The eastside is marked by historic streetcar suburbs, built from the 1890s–1930s as havens for the upper middle class. These neighborhoods, many of which contain their own villages encircled by shaded, architecturally distinct residential streets, include the Victorian Inman Park, Bohemian East Atlanta, and eclectic Old Fourth Ward. On the westside and along the BeltLine on the eastside, former warehouses and factories have been converted into housing, retail space, and art galleries, transforming the once-industrial areas such as West Midtown into model neighborhoods for smart growth, historic rehabilitation, and infill construction.
In southwest Atlanta, neighborhoods closer to downtown originated as streetcar suburbs, including the historic West End, while those farther from downtown retain a postwar suburban layout. These include Collier Heights and Cascade Heights, home to much of the city's affluent African-American population. Northwest Atlanta contains the areas of the city to west of Marietta Boulevard and to the north of Martin Luther King, Jr. Drive, including those neighborhoods remote to downtown, such as Riverside, Bolton and Whittier Mill. The latter is one of Atlanta's designated Landmark Historical Neighborhoods. Vine City, though technically Northwest, adjoins the city's Downtown area and has recently been the target of community outreach programs and economic development initiatives.
Gentrification of the city's neighborhoods is one of the more controversial and transformative forces shaping contemporary Atlanta. The gentrification of Atlanta has its origins in the 1970s, after many of Atlanta's neighborhoods had declined and suffered the urban decay that affected other major American cities in the mid-20th century. When neighborhood opposition successfully prevented two freeways from being built through the city's east side in 1975, the area became the starting point for Atlanta's gentrification. After Atlanta was awarded the Olympic games in 1990, gentrification expanded into other parts of the city, stimulated by infrastructure improvements undertaken in preparation for the games. New development post-2000 has been aided by the Atlanta Housing Authority's eradication of the city's public housing. As noted above, it allowed development of these sites for mixed-income housing, requiring developers to reserve a considerable portion for affordable housing units. It has also provided for other former residents to be given vouchers to gain housing in other areas. Construction of the Beltline has stimulated new and related development along its path.
Atlanta has a humid subtropical climate ("Cfa") according to the Köppen classification, with the seasons more or less defined. The winter has a shorter duration, with hot and humid summers and mild winters (in some cases the outbreaks are cold), but susceptible to snowstorms even if in small quantities on several occasions, unlike the rest of the southeastern United States. Winters are mild but variable, with an average of 48 freezing days per year, though temperatures very rarely drop even close to . Warm air from the Gulf of Mexico can bring spring-like highs while strong Arctic air masses can push lows into the teens °F (−7 to −12 °C).
July averages , with high temperatures reaching on an average 44 days per year, though readings are not seen most years. January averages , with temperatures in the suburbs slightly cooler due largely to the urban heat island effect. Lows at or below freezing can be expected 40 nights annually, but extended stretches with daily high temperatures below are very rare, with a recent exception in January 2014. Extremes range from on February 13, 1899 to on June 30, 2012. Average dewpoints in the summer range from in June to in July. According to the USDA, Atlanta is situated in Hardiness Zone 8a, with northern and western suburbs transitioning to 7b.
Typical of the southeastern U.S., Atlanta receives abundant rainfall that is evenly distributed throughout the year, though late spring and early fall are somewhat drier. The average annual rainfall is , while snowfall is typically light at around 2.9 to 5 inches per year. The heaviest single snowfall occurred on January 23, 1940, with around of snow. However, ice storms usually cause more problems than snowfall does, the most severe occurring on January 7, 1973. Tornadoes are rare in the city, but the March 14, 2008 EF2 tornado damaged prominent structures in downtown Atlanta.
The 2010 United States Census reported that Atlanta had a population of 420,003. The population density was 3,154 per square mile (1232/km2). The racial makeup and population of Atlanta was 54.0% Black or African American, 38.4% White, 3.1% Asian and 0.2% Native American. Those from some other race made up 2.2% of the city's population, while those from two or more races made up 2.0%. Hispanics of any race made up 5.2% of the city's population. The median income for a household in the city was $45,171. The per capita income for the city was $35,453. 22.6% percent of the population was living below the poverty line.
Atlanta has one of the highest LGBT populations per capita, according to a survey by the Williams Institute, ranking third among major American cities, behind San Francisco and slightly behind Seattle, with 12.8% of the city's total population identifying as lesbian, gay, bisexual, or transgender.
In the 1920s, the black population began to grow in Southern cities like Atlanta, Birmingham, Houston, and Memphis. In the 2010 Census, Atlanta was recorded as the nation's fourth-largest majority-black city. The New Great Migration has brought an insurgence of African Americans from California and the North to the Atlanta area. It has long been known as a center of African-American political power, education, economic prosperity, and culture, often called a black mecca. Some middle and upper class African-American residents of Atlanta followed an influx of whites to newer housing and public schools in the suburbs in the early 21st century. From 2000 to 2010, the city's black population decreased by 31,678 people, shrinking from 61.4% of the city's population in 2000 to 54.0% in 2010, as the overall population expanded and migrants increased from other areas.
At the same time, the white population of Atlanta has increased. Between 2000 and 2010, the proportion of whites in the city's population grew faster than in any other U.S. city. In that decade, Atlanta's white population grew from 31% to 38% of the city's population, an absolute increase of 22,753 people, more than triple the increase that occurred between 1990 and 2000.
Of the total population five years and older, 83.3% spoke only English at home, while 8.8% spoke Spanish, 3.9% another Indo-European language, and 2.8% an Asian language. 7.3% of Atlantans were born abroad (86th in the US). Atlanta's dialect has traditionally been a variation of Southern American English. The Chattahoochee River long formed a border between the Coastal Southern and Southern Appalachian dialects. Because of the development of corporate headquarters in the region, attracting migrants from other areas of the country, by 2003, "Atlanta" magazine concluded that Atlanta had become significantly "de-Southernized". A Southern accent was considered a handicap in some circumstances. In general, Southern accents are less prevalent among residents of the city and inner suburbs and among younger people; they are more common in the outer suburbs and among older people. At the same time, some residents of the city speak in Southern variations of African-American English.
Religion in Atlanta, while historically centered on Protestant Christianity, now encompasses many faiths, as a result of the city and metro area's increasingly international population. Some 63% of residents identify as some type of Protestant, but in recent decades the Catholic Church has increased in numbers and influence because of new migrants to the region. Metro Atlanta also has numerous ethnic or national Christian congregations, including Korean and Indian churches. The larger non-Christian faiths are Judaism, Islam, and Hinduism. Overall, there are over 1,000 places of worship within Atlanta.
Early immigrants in Atlanta were Jews and Greeks. Since 1970, the Latino immigrant population, especially Mexicans, has experienced the most rapid growth, mainly in Gwinnett, Cobb, and DeKalb counties. Since 2010, the Atlanta area has seen very notable growth with immigrants from India, China, South Korea, and Jamaica. Other notable countries immigrants come from are Vietnam, Eritrea, Nigeria, the Arabian gulf, Ukraine and Poland. Within a few decades, and in keeping with national trends, immigrants from England, Ireland, and German-speaking central Europe were no longer the majority of Atlanta's foreign-born population. The city's Italians included immigrants from northern Italy, many of whom had been in Atlanta since the 1890s; more recent arrivals from southern Italy; and Sephardic Jews from the Isle of Rhodes, which Italy had seized from Turkey in 1912.
With a GDP of $385 billion, the Atlanta metropolitan area's economy is the tenth-largest in the country and among the top 20-largest in the world. Corporate operations play a major role in Atlanta's economy, as the city claims the nation's third-largest concentration of Fortune 500 companies. It also hosts the global headquarters of corporations like The Coca-Cola Company, The Home Depot, Delta Air Lines, AT&T Mobility, Chick-fil-A, and UPS. Over 75% of Fortune 1000 companies conduct business operations in the city's metro area, and the region hosts offices of over 1,250 multinational corporations. Many corporations are drawn to the city by its educated workforce; , 45% of adults aged 25 or older residing in the city have at least 4-year college degrees, compared to the national average of 28%.
Atlanta started as a railroad town, and logistics has been a major component of the city's economy to this day. Atlanta serves as an important rail junction and contains major classification yards for Norfolk Southern and CSX. Since its construction in the 1950s, Hartsfield–Jackson Atlanta International Airport has served as a key engine of the city's economic growth. Delta Air Lines, the city's largest employer and the metro area's third-largest, operates the world's largest airline hub at Hartsfield-Jackson, and it has helped make it the world's busiest airport, in terms of both passenger traffic and aircraft operations. Partly due to the airport, Atlanta has been also a hub for diplomatic missions; , the city contains 26 consulates general, the seventh-highest concentration of diplomatic missions in the US.
Broadcasting is also an important aspect of Atlanta's economy. In the 1980s, media mogul Ted Turner founded the Cable News Network (CNN) and the Turner Broadcasting System (TBS) in the city. Around the same time, Cox Enterprises, now the nation's third-largest cable television service and the publisher of over a dozen American newspapers, moved its headquarters to the city. The Weather Channel is also based just outside of the city in suburban Cobb County.
Information technology (IT) has become an increasingly important part of Atlanta's economic output, earning the city the nickname the "Silicon peach". , Atlanta contains the fourth-largest concentration of IT jobs in the US, numbering 85,000+. The city is also ranked as the sixth fastest-growing for IT jobs, with an employment growth of 4.8% in 2012 and a three-year growth near 9%, or 16,000 jobs. Companies are drawn to Atlanta's lower costs and educated workforce.
Recently, Atlanta has been a center for film and television production, largely because of the Georgia Entertainment Industry Investment Act, which awards qualified productions a transferable income tax credit of 20% of all in-state costs for film and television investments of $500,000 or more. Film and television production facilities based in Atlanta include Turner Studios, Pinewood Studios (Pinewood Atlanta), Tyler Perry Studios, Williams Street Productions, and the EUE/Screen Gems soundstages. Film and television production injected $9.5 billion into Georgia's economy in 2017, with Atlanta garnering most of the projects. As a result, by the following year, Atlanta emerged as one of the all-time most popular destinations for film production globally.
Compared to other American cities, Atlanta's economy in the past had been disproportionately affected by the 2008 financial crisis and the subsequent recession, with the city's economy earning a ranking of 68 among 100 American cities in a September 2014 report due to an elevated unemployment rate, declining real income levels, and a depressed housing market. From 2010 to 2011, Atlanta saw a 0.9% contraction in employment and plateauing income growth at 0.4%. Although unemployment had decreased to 7% by late 2014, this was still higher than the national unemployment rate of 5.8% Atlanta's housing market has also struggled, with home prices dropping by 2.1% in January 2012, reaching levels not seen since 1996. Compared with a year earlier, the average home price in Atlanta plummeted to 17.3% in February 2012, thus becoming the largest annual drop in the history of the index for any American or global city. The decline in home prices prompted some economists to deem Atlanta the worst housing market in the nation at the height of the depression. Nevertheless, the city's real estate market has resurged since 2012, so much median home value and rent growth significantly outpaced the national average by 2018, thanks to a rapidly-growing regional economy.
Atlanta is noted for its Southern culture. This is due to a large population of migrants from other parts of the U.S., in addition to many recent immigrants to the U.S. who have made the metropolitan area their home, establishing Atlanta as the cultural and economic hub of an increasingly multi-cultural metropolitan area. Thus, although traditional Southern culture is part of Atlanta's cultural fabric, it is mostly the backdrop to one of the nation's most cosmopolitan cities. This unique cultural combination reveals itself in the arts district of Midtown, the quirky neighborhoods on the city's eastside, and the multi-ethnic enclaves found along Buford Highway.
Atlanta is one of few United States cities with permanent, professional, and resident companies in all major performing arts disciplines: opera (Atlanta Opera), ballet (Atlanta Ballet), orchestral music (Atlanta Symphony Orchestra), and theater (the Alliance Theatre). Atlanta attracts many touring Broadway acts, concerts, shows, and exhibitions catering to a variety of interests. Atlanta's performing arts district is concentrated in Midtown Atlanta at the Woodruff Arts Center, which is home to the Atlanta Symphony Orchestra and the Alliance Theatre. The city frequently hosts touring Broadway acts, especially at The Fox Theatre, a historic landmark among the highest-grossing theaters of its size.
As a national center for the arts, Atlanta is home to significant art museums and institutions. The renowned High Museum of Art is arguably the South's leading art museum and among the most-visited art museums in the world. The Museum of Design Atlanta (MODA) and the SCAD FASH Museum of Fashion + Film are the only such museums in the Southeast. Contemporary art museums include the Atlanta Contemporary Art Center and the Museum of Contemporary Art of Georgia. Institutions of higher education contribute to Atlanta's art scene, with the Savannah College of Art and Design's Atlanta campus providing the city's arts community with a steady stream of curators, and Emory University's Michael C. Carlos Museum containing the largest collection of ancient art in the Southeast.
Atlanta has become one of the USA's best cities for street art in recent years. It is home to Living Walls, an annual street art conference and the Outerspace Project, an annual event series that merges public art, live music, design, action sports, and culture. Examples of street art in Atlanta can be found on the Atlanta Street Art Map.
Atlanta has played a major or contributing role in the development of various genres of American music at different points in the city's history. Beginning as early as the 1920s, Atlanta emerged as a center for country music, which was brought to the city by migrants from Appalachia. During the countercultural 1960s, Atlanta hosted the Atlanta International Pop Festival, with the 1969 festival taking place more than a month before Woodstock and featuring many of the same bands. The city was also a center for Southern rock during its 1970s heyday: the Allman Brothers Band's hit instrumental "Hot 'Lanta" is an ode to the city, while Lynyrd Skynyrd's famous live rendition of "Free Bird" was recorded at the Fox Theatre in 1976, with lead singer Ronnie Van Zant directing the band to "play it pretty for Atlanta". During the 1980s, Atlanta had an active punk rock scene centered on two of the city's music venues, 688 Club and the Metroplex, and Atlanta famously played host to the Sex Pistols' first U.S. show, which was performed at the Great Southeastern Music Hall. The 1990s saw the city produce major mainstream acts across many different musical genres. Country music artist Travis Tritt, and R&B sensations TLC, Usher and Toni Braxton, were just some of the musicians proud to call Atlanta home. The city also gave birth to Atlanta hip hop, a subgenre that gained relevance and success with the introduction of the home-grown ATLiens known as Outkast, along with other Dungeon Family artists such as Organized Noize and Goodie Mob; however, it was not until the 2000s that Atlanta moved "from the margins to becoming hip-hop's center of gravity with another sub-genre called Crunk, part of a larger shift in hip-hop innovation to the South and East". Also in the 2000s, Atlanta was recognized by the Brooklyn-based "Vice" magazine for its indie rock scene, which revolves around the various live music venues found on the city's alternative eastside. To facilitate further local development, the state government provides qualified businesses and productions a 15% transferable income tax credit for in-state costs of music investments. Trap music became popular in Atlanta due to the success of T.I., 21 Savage, Gucci Mane, Future, Migos, Lil Yachty, 2 Chainz and Young Thug.
As a national center for cinema and television production, Atlanta plays a significant role in the entertainment industry. Atlanta is considered a hub for filmmakers of color and houses Tyler Perry's studios. Atlanta doubles for other parts of the world and fictional settlements in blockbuster productions, among them the newer titles from "The Fast and the Furious" franchise and Marvel features such as "Ant-Man" (2015), "" (2016), "Black Panther" and "" (both 2018). On the other hand, "Gone With the Wind" (1939), "Smokey and the Bandit" (1977), "Sharkey's Machine" (1981), "The Slugger's Wife" (1985), "Driving Miss Daisy" (1989), "ATL" (2006), and "Baby Driver" (2017) are among several notable examples of films actually set in Atlanta. The city also provides the backdrop for shows such as "The Walking Dead", "Stranger Things", "The Vampire Diaries" and "Atlanta", in addition to a myriad of animated and reality television programming.
Atlanta has more festivals than any city in the southeastern United States.
Some notable festivals in Atlanta include Shaky Knees Music Festival, Dragon Con, the Peachtree Road Race, Music Midtown, the Atlanta Film Festival, National Black Arts Festival, Festival Peachtree Latino, Atlanta Pride, the neighborhood festivals in Inman Park, Atkins Park, Virginia-Highland (Summerfest), and the Little Five Points Halloween festival.
, Atlanta is the seventh-most visited city in the United States, with over 35 million visitors per year. Although the most popular attraction among visitors to Atlanta is the Georgia Aquarium, the world's largest indoor aquarium, Atlanta's tourism industry is mostly driven by the city's history museums and outdoor attractions. Atlanta contains a notable number of historical museums and sites, including the Martin Luther King Jr. National Historic Site, which includes the preserved childhood home of Dr. Martin Luther King Jr., as well as his final resting place; the Atlanta Cyclorama & Civil War Museum, which houses a massive painting and diorama in-the-round, with a rotating central audience platform, depicting the Battle of Atlanta in the Civil War; the World of Coca-Cola, featuring the history of the world-famous soft drink brand and its well-known advertising; the College Football Hall of Fame, which honors college football and its athletes; the National Center for Civil and Human Rights, which explores the civil rights movement and its connection to contemporary human rights movements throughout the world; the Carter Center and Presidential Library, housing U.S. President Jimmy Carter's papers and other material relating to the Carter administration and the Carter family's life; and the Margaret Mitchell House and Museum, where Mitchell wrote the best-selling novel "Gone with the Wind".
Atlanta contains several outdoor attractions. The Atlanta Botanical Garden, adjacent to Piedmont Park, is home to the Kendeda Canopy Walk, a skywalk that allows visitors to tour one of the city's last remaining urban forests from above the ground. The Canopy Walk is considered the only canopy-level pathway of its kind in the United States. Zoo Atlanta, in Grant Park, accommodates over 1,300 animals representing more than 220 species. Home to the nation's largest collections of gorillas and orangutans, the zoo is one of only four zoos in the U.S. to house giant pandas. Festivals showcasing arts and crafts, film, and music, including the Atlanta Dogwood Festival, the Atlanta Film Festival, and Music Midtown, respectively, are also popular with tourists.
Tourists are drawn to the city's culinary scene, which comprises a mix of urban establishments garnering national attention, ethnic restaurants serving cuisine from every corner of the world, and traditional eateries specializing in Southern dining. Since the turn of the 21st century, Atlanta has emerged as a sophisticated restaurant town. Many restaurants opened in the city's gentrifying neighborhoods have received praise at the national level, including Bocado, Bacchanalia, and Miller Union in West Midtown, Empire State South in Midtown, and Two Urban Licks and Rathbun's on the east side. In 2011, "The New York Times" characterized Empire State South and Miller Union as reflecting "a new kind of sophisticated Southern sensibility centered on the farm but experienced in the city". Visitors seeking to sample international Atlanta are directed to Buford Highway, the city's international corridor, and suburban Gwinnett County. There, the nearly-million immigrants that make Atlanta home have established various authentic ethnic restaurants representing virtually every nationality on the globe. For traditional Southern fare, one of the city's most famous establishments is The Varsity, a long-lived fast food chain and the world's largest drive-in restaurant. Mary Mac's Tea Room and Paschal's are more formal destinations for Southern food.
Sports are an important part of the culture of Atlanta. The city is home to professional franchises for four major team sports: the Atlanta Braves of Major League Baseball, the Atlanta Hawks of the National Basketball Association, the Atlanta Falcons of the National Football League, and Atlanta United FC of Major League Soccer. In addition, many of the city's universities participate in collegiate sports. The city also regularly hosts international, professional, and collegiate sporting events.
The Braves moved to Atlanta in 1966. Originally established as the Boston Red Stockings in 1871, they are the oldest continually operating professional sports franchise in the United States. The Braves won the World Series in 1995, during an unprecedented run of 14 straight divisional championships from 1991 to 2005. The team plays at Truist Park, having moved from Turner Field for the 2017 season. The new stadium is outside the city limits, located northwest of downtown in the Cumberland/Galleria area of Cobb county.
The Atlanta Falcons have played in Atlanta since their inception in 1966. The team play their home games at Mercedes Benz Stadium, having moved from the Georgia Dome in 2017. The Falcons have won the division title six times (1980, 1998, 2004, 2010, 2012, 2016) and the NFC championship twice in 1998 and 2016. However, they have been unsuccessful in both of their Super Bowl trips, losing to the Denver Broncos in Super Bowl XXXIII in 1999 and to the New England Patriots in Super Bowl LI in 2017. In 2019, Atlanta also briefly hosted an Alliance of American Football team, the Atlanta Legends, but the league was suspended during its first season and the team folded.
The Atlanta Hawks were founded in 1946 as the Tri-Cities Blackhawks, playing in Moline, Illinois. they moved to Atlanta in 1968 and play their games in State Farm Arena. The city is also home to a Women's National Basketball Association franchise, the Atlanta Dream, who share the stadium with the Hawks.
Professional soccer has been played in some form in Atlanta since 1967. Atlanta's first professional soccer team was the Atlanta Chiefs of the original North American Soccer League which won the 1968 NASL Championship and defeated English first division club Manchester City F.C. twice in international friendlies. In 1998 the Atlanta Silverbacks were formed, playing the new North American Soccer League. They now play as an amateur club in the National Premier Soccer League. In 2017, Atlanta United FC began play as Atlanta's first premier-division professional soccer club since the Chiefs. They won MLS Cup 2018, defeating the Portland Timbers 2–0. Fan reception has been very positive; the team has broken several single-game and season attendance records for both MLS and the U.S. Open Cup. The club is estimated by Forbes to be the most valuable club in Major League Soccer.
In ice hockey, Atlanta has had two National Hockey League franchises, both of which relocated after playing in Atlanta for fewer than 15 years. The Atlanta Flames began play in 1972 before moving to Calgary in 1980, and the Atlanta Thrashers began play in 1999 before moving to Winnipeg in 2011. The Atlanta Gladiators of the ECHL Play in Duluth, a suburb northeast of the city.
Several other, less popular sports also have professional franchises in Atlanta. The Georgia Swarm compete in the National Lacrosse League. On September 21, 2018, Major League Rugby announced that Atlanta was one of the expansion teams joining the league for the 2020 season named Rugby ATL. On August 2, 2018, it was announced that Atlanta would have its own Overwatch League team, Atlanta Reign.
Atlanta regularly hosts a variety of sporting events. Most famous was the Centennial 1996 Summer Olympics. The city has hosted the super bowl three times: Super Bowl XXVIII in 1994, Super Bowl XXXIV in 2000, and Super Bowl LIII in 2019. In professional golf, The Tour Championship, the final PGA Tour event of the season, is played annually at East Lake Golf Club. In 2001 and 2011, Atlanta hosted the PGA Championship, one of the four major championships in men's professional golf, at the Atlanta Athletic Club. In 2011, Atlanta hosted professional wrestling's annual WrestleMania. In soccer, Atlanta has hosted numerous international friendlies and CONCACAF Gold Cup matches. The city has hosted the NCAA Final Four Men's Basketball Championship four times, most recently in 2013. In college football, Atlanta hosted the 2018 College Football Playoff National Championship, and annually hosts the Chick-fil-A Kickoff Game, the SEC Championship Game, the Celebration Bowl, the MEAC/SWAC Challenge, and the Chick-fil-A Peach Bowl.
Running is a popular local sport, and the city declares itself to be "Running City USA". The city hosts the Peachtree Road Race, the world's largest race, annually on Independence Day. Atlanta also hosts the nation's largest Thanksgiving day half marathon, which starts and ends at Georgia State Stadium. The Atlanta Marathon, which starts and ends at Centennial Olympic Park, routes through many of the city's historic landmarks, and its 2020 running will coincide with the U.S. Olympic marathon trials for the 2020 Summer Olympics.
Atlanta's 343 parks, nature preserves, and gardens cover , which amounts to only 5.6% of the city's total acreage, compared to the national average of just over 10%. However, 64% of Atlantans live within a 10-minute walk of a park, a percentage equal to the national average. In its 2013 ParkScore ranking, The Trust for Public Land reported that among the park systems of the 50 most populous U.S. cities, Atlanta's park system received a ranking of 31. Piedmont Park, in Midtown, is Atlanta's most iconic green space. The park, which underwent a major renovation and expansion in recent years, attracts visitors from across the region and hosts cultural events throughout the year. Other notable city parks include Centennial Olympic Park, a legacy of the 1996 Summer Olympics that forms the centerpiece of the city's tourist district; Woodruff Park, which anchors the campus of Georgia State University; Grant Park, home to Zoo Atlanta; Chastain Park, which houses an amphitheater used for live music concerts; and the under construction Westside Park at Bellwood Quarry, the 280-acre green space and reservoir project slated to become the city's largest park when fully complete in the 2020s. The Chattahoochee River National Recreation Area, in the northwestern corner of the city, preserves a stretch of the river for public recreation opportunities.
The Atlanta Botanical Garden, adjacent to Piedmont Park, contains formal gardens, including a Japanese garden and a rose garden, woodland areas, and a conservatory that includes indoor exhibits of plants from tropical rainforests and deserts. The BeltLine, a former rail corridor that forms a loop around Atlanta's core, has been transformed into a series of parks, connected by a multi-use trail, increasing Atlanta's park space by 40%.
Atlanta offers resources and opportunities for amateur and participatory sports and recreation. Golf and tennis are popular in Atlanta, and the city contains six public golf courses and 182 tennis courts. Facilities along the Chattahoochee River cater to watersports enthusiasts, providing the opportunity for kayaking, canoeing, fishing, boating, or tubing. The city's only skate park, a facility that offers bowls, curbs, and smooth-rolling concrete mounds, is at Historic Fourth Ward Park.
Atlanta is governed by a mayor and the Atlanta City Council. The city council consists of 15 representatives—one from each of the city's 12 districts and three at-large positions. The mayor may veto a bill passed by the council, but the council can override the veto with a two-thirds majority. The mayor of Atlanta is Keisha Lance Bottoms, a Democrat elected on a nonpartisan ballot whose first term in office began on January 2, 2018. Every mayor elected since 1973 has been black. In 2001, Shirley Franklin became the first woman to be elected mayor of Atlanta, and the first African-American woman to serve as mayor of a major Southern city. Atlanta city politics suffered from a notorious reputation for corruption during the 1990s administration of Mayor Bill Campbell, who was convicted by a federal jury in 2006 on three counts of tax evasion in connection with gambling winnings during trips he took with city contractors.
As the state capital, Atlanta is the site of most of Georgia's state government. The Georgia State Capitol building, located downtown, houses the offices of the governor, lieutenant governor and secretary of state, as well as the General Assembly. The Governor's Mansion is in a residential section of Buckhead. Atlanta serves as the regional hub for many arms of the federal bureaucracy, including the Federal Reserve Bank of Atlanta and the Centers for Disease Control and Prevention (CDC). The City of Atlanta annexed the CDC into its territory effective January 1, 2018. Atlanta also plays an important role in the federal judiciary system, containing the United States Court of Appeals for the Eleventh Circuit and the United States District Court for the Northern District of Georgia.
Historically, Atlanta has been a stronghold for the Democratic Party. Although municipal elections are officially nonpartisan, nearly all of the city's elected officials are registered Democrats. The city is split among 14 state house districts and four state senate districts, all held by Democrats. At the federal level, Atlanta is split between two congressional districts. Most of the city is in the 5th district, represented by Democrat John Lewis. A small portion in the north is in the 11th district, represented by Republican Barry Loudermilk.
The city is served by the Atlanta Police Department, which numbers 2,000 officers and oversaw a 40% decrease in the city's crime rate between 2001 and 2009. Specifically, homicide decreased by 57%, rape by 72%, and violent crime overall by 55%. Crime is down across the country, but Atlanta's improvement has occurred at more than twice the national rate. Nevertheless, Forbes ranked Atlanta as the sixth most dangerous city in the United States in 2012. Aggravated assaults, burglaries and robberies were down from 2014. Mexican drug cartels thrive in Atlanta. 145 gangs operate in Atlanta.
The Atlanta Fire Rescue Department provides fire protection and first responder emergency medical services to the city from its 35 fire stations. In 2017, AFRD responded to over 100,000 calls for service over a coverage area of . The department also protects Hartsfield–Jackson with 5 fire stations on the property; serving over 1 million passengers from over 100 different countries. The department protects over 3000 highrise buildings, of the rapid rail system, and of interstate highway.
Emergency ambulance services are provided to city residents by hospital based Grady EMS (Fulton County), and American Medical Response (DeKalb County).
Atlanta in January 2017 declared the city was a "welcoming city" and "will remain open and welcoming to all". Nonetheless, Atlanta does not consider itself to be a "sanctuary city". Atlanta Mayor Keisha Lance Bottoms said: "Our city does not support ICE. We don't have a relationship with the U.S. Marshal[s] Service. We closed our detention center to ICE detainees, and we would not pick up people on an immigration violation."
Due to more than 15 colleges and universities in Atlanta, it is considered one of the nation's largest hubs for higher education.
The Georgia Institute of Technology is a prominent public research university in Midtown. It offers highly ranked degree programs in engineering, design, industrial management, the sciences, and architecture.
The University of Georgia, chartered in 1785, is one of the top public research universities in the nation with "Highest Research Activity" and based about an hour away in Athens, Georgia; however, the Atlanta Center of its Terry College of Business is in the Buckhead area of Atlanta and the university has a metropolitan Atlanta Gwinnett Campus that occupies 60,000 square feet of the Intellicenter.
Georgia State University is a major public research university in Downtown Atlanta; it is the largest of the 29 public colleges and universities in the University System of Georgia and is a significant contributor to the revitalization of the city's central business district.
Atlanta is home to nationally renowned private colleges and universities, most notably Emory University, a leading liberal arts and research institution that consistently ranks among the top 25 universities in the United States and operates Emory Healthcare, the largest health care system in Georgia. The City of Atlanta annexed Emory into its territory effective January 1, 2018.
The Atlanta University Center is also in the city; it is the largest contiguous consortium of historically black colleges in the nation, comprising Spelman College, Clark Atlanta University, Morehouse College, and Morehouse School of Medicine. Atlanta contains a campus of the Savannah College of Art and Design, a private art and design university that has proven to be a major factor in the recent growth of Atlanta's visual art community. Atlanta and nearby Athens also boast American Bar Association accredited law schools: Atlanta's John Marshall Law School, Emory University School of Law, Georgia State University College of Law and University of Georgia School of Law.
The Atlanta Regional Council of Higher Education (ARCHE) is dedicated to strengthening synergy among 19 public and private colleges and universities in the Atlanta region. Participating Atlanta region colleges and universities partner on joint-degree programs, cross-registration, library services, and cultural events.
Fifty-five thousand students are enrolled in 106 schools in Atlanta Public Schools (APS), some of which are operated as charter schools. Atlanta is served by many private schools including, without limitation, Atlanta Jewish Academy, Atlanta International School, The Westminster Schools, Pace Academy, The Lovett School, The Paideia School, Holy Innocents' Episcopal School and Roman Catholic parochial schools operated by the Archdiocese of Atlanta.
In 2018 the City of Atlanta annexed a portion of DeKalb County containing the Centers for Disease Control and Emory University; this portion will be zoned to the DeKalb County School District until 2024, when it will transition into APS.
The primary network-affiliated television stations in Atlanta are WXIA-TV 11 (NBC), WGCL-TV 46 (CBS), WSB-TV 2 (ABC), and WAGA-TV 5 (Fox). Other major commercial stations include WPXA-TV 14 (Ion), WPCH-TV 17 (Ind.), WUVG-TV 34 (Univision), WUPA 69 (CW), and WATL 36 (MyNetworkTV). WPXA-TV, WUVG-TV, WAGA-TV and WUPA are network O&O's. The Atlanta metropolitan area is served by two public television stations (both PBS member stations), and two public radio stations. WGTV 8 is the flagship station of the statewide Georgia Public Television network, while WPBA is owned by Atlanta Public Schools. Georgia Public Radio is listener-funded and comprises one NPR member station, WABE, a classical music station operated by Atlanta Public Schools. The second public radio, listerner-funded NPR member station is WCLK, a jazz music station owned and operated by Clark Atlanta University.
Atlanta is served by the "Atlanta Journal-Constitution", its only major daily newspaper with wide distribution. The "Atlanta Journal-Constitution" is the result of a 1950 merger between "The Atlanta Journal" and "The Atlanta Constitution", with staff consolidation occurring in 1982 and separate publication of the morning "Constitution" and afternoon "Journal" ceasing in 2001. Alternative weekly newspapers include "Creative Loafing", which has a weekly print circulation of 80,000. "Atlanta" magazine is an award-winning, monthly general-interest magazine based in and covering Atlanta.
Atlanta's transportation infrastructure comprises a complex network that includes a heavy rail rapid transit system, a light rail streetcar loop, a multi-county bus system, Amtrak service via the Crescent, multiple freight train lines, an Interstate Highway System, several airports, including the world's busiest, and over of bike paths.
Atlanta has a network of freeways that radiate out from the city, and automobiles are the dominant means of transportation in the region. Three major interstate highways converge in Atlanta: I-20 (east-west), I-75 (northwest-southeast), and I-85 (northeast-southwest). The latter two combine in the middle of the city to form the Downtown Connector (I-75/85), which carries more than 340,000 vehicles per day and is one of the most congested segments of interstate highway in the United States. Atlanta is mostly encircled by Interstate 285, a beltway locally known as "the Perimeter" that has come to mark the boundary between "Inside the Perimeter" (ITP), the city and close-in suburbs, and "Outside the Perimeter" (OTP), the outer suburbs and exurbs. The heavy reliance on automobiles for transportation in Atlanta has resulted in traffic, commute, and air pollution rates that rank among the worst in the country. The City of Atlanta has a higher than average percentage of households without a car. In 2015, 15.2 percent of Atlanta households lacked a car, and increased slightly to 16.4 percent in 2016. The national average is 8.7 percent in 2016. Atlanta averaged 1.31 cars per household in 2016, compared to a national average of 1.8.
The Metropolitan Atlanta Rapid Transit Authority (MARTA) provides public transportation in the form of buses, heavy rail, and a downtown light rail loop. Notwithstanding heavy automotive usage in Atlanta, the city's subway system is the eighth busiest in the country. MARTA rail lines connect key destinations, such as the airport, Downtown, Midtown, Buckhead, and Perimeter Center. However, significant destinations, such as Emory University and Cumberland, remain unserved. As a result, a 2011 Brookings Institution study placed Atlanta 91st of 100 metro areas for transit accessibility. Emory University operates its Cliff shuttle buses with 200,000 boardings per month, while private minibuses supply Buford Highway. Amtrak, the national rail passenger system, provides service to Atlanta via the "Crescent train" (New York–New Orleans), which stops at Peachtree Station. In 2014, the Atlanta Streetcar opened to the public. The streetcar's line, which is also known as the Downtown Loop, runs around the downtown tourist areas of Peachtree Center, Centennial Olympic Park, the Martin Luther King, Jr. National Historic Site, and Sweet Auburn. The Atlanta Streetcar line is also being expanded on in the coming years to include a wider range of Atlanta's neighborhoods and important places of interest, with a total of over of track in the plan.
Hartsfield–Jackson Atlanta International Airport is the world's busiest airport as measured by passenger traffic and aircraft traffic. The facility offers air service to over 150 U.S. destinations and more than 75 international destinations in 50 countries, with over 2,500 arrivals and departures daily. Delta Air Lines maintains its largest hub at the airport. Situated () south of downtown, the airport covers most of the land inside a wedge formed by Interstate 75, Interstate 85, and Interstate 285.
Cycling is a growing mode of transportation in Atlanta, more than doubling since 2009, when it comprised 1.1% of all commutes (up from 0.3% in 2000). Although Atlanta's lack of bike lanes and hilly topography may deter many residents from cycling, the city's transportation plan calls for the construction of of bike lanes by 2020, with the BeltLine helping to achieve this goal. In 2012, Atlanta's first "bike track" was constructed on 10th Street in Midtown. The two lane bike track runs from Monroe Drive west to Charles Allen Drive, with connections to the Beltline and Piedmont Park. Starting in June 2016, Atlanta received a bike sharing program, known as Relay Bike Share, with 100 bikes in Downtown and Midtown, which expanded to 500 bikes at 65 stations as of April 2017.
According to the 2016 American Community Survey (five-year average), 68.6% of working city of Atlanta residents commuted by driving alone, 7% carpooled, 10% used public transportation, and 4.6% walked. About 2.1% used all other forms of transportation, including taxi, bicycle, and motorcycle. About 7.6% worked at home.
The city has also become one of a handful of "scooter capitals", where companies like Lime and Bird have gained a major foothold by placing electric scooters on street corners and byways.
Atlanta has a reputation as a "city in a forest" due to an abundance of trees that is rare among major cities. The city's main street is named after a tree, and beyond the Downtown, Midtown, and Buckhead business districts, the skyline gives way to a dense canopy of woods that spreads into the suburbs. The city is home to the Atlanta Dogwood Festival, an annual arts and crafts festival held one weekend during early April, when the native dogwoods are in bloom. The nickname is factually accurate, as vegetation covers 47.9% of the city as of 2017, the highest among all major American cities, and well above the national average of 27%. Atlanta's tree coverage does not go unnoticed—it was the main reason cited by "National Geographic" in naming Atlanta a "Place of a Lifetime".
The city's lush tree canopy, which filters out pollutants and cools sidewalks and buildings, has increasingly been under assault from man and nature due to heavy rains, drought, aged forests, new pests, and urban construction. A 2001 study found Atlanta's heavy tree cover declined from 48% in 1974 to 38% in 1996. Community organizations and the city government are addressing the problem. Trees Atlanta, a non-profit organization founded in 1985, has planted and distributed over 113,000 shade trees in the city, and Atlanta's government has awarded $130,000 in grants to neighborhood groups to plant trees. Fees are additionally imposed on developers that remove trees on their property per a citywide ordinance, active since 1993.
Atlanta has 17 sister cities, as designated by Sister Cities International, Inc. (SCI): | https://en.wikipedia.org/wiki?curid=3138 |
Axiology
Axiology (from Greek , "axia", "value, worth"; and , "-logia") is the philosophical study of value. It is either the collective term for ethics and aesthetics, philosophical fields that depend crucially on notions of worth, or the foundation for these fields, and thus similar to value theory and meta-ethics. The term was first used by Paul Lapie, in 1902, and Eduard von Hartmann, in 1908.
Axiology studies mainly two kinds of values: ethics and aesthetics. Ethics investigates the concepts of "right" and "good" in individual and social conduct. Aesthetics studies the concepts of "beauty" and "harmony." Formal axiology, the attempt to lay out principles regarding value with mathematical rigor, is exemplified by Robert S. Hartman's science of value.
Between the 5th and 6th centuries BC, it was important in Greece to be knowledgeable if you were to be successful. Philosophers began to recognize that differences existed between the laws and morality of society. Socrates believed that knowledge had a vital connection to virtue, making morality and democracy closely intertwined. Socrates' student, Plato furthered the belief by establishing virtues which should be followed by all. With the fall of the government, values became individual, causing skeptic schools of thought to flourish, ultimately shaping a pagan philosophy that is thought to have influenced and shaped Christianity. During the medieval period, Thomas Aquinas made the distinction between natural and supernatural (theological) virtues. This concept led philosophers to distinguish between judgments based on fact and judgments based on values, creating division between science and philosophy. | https://en.wikipedia.org/wiki?curid=3143 |
A Doll's House
A Doll's House (Danish and ; also translated as "A Doll House") is a three-act play written by Henrik Ibsen. It premiered at the Royal Theatre in Copenhagen, Denmark, on 21 December 1879, having been published earlier that month. The play is set in a Norwegian town circa 1879.
The play is significant for the way it deals with the fate of a married woman, who at the time in Norway lacked reasonable opportunities for self-fulfillment in a male-dominated world, despite the fact that Ibsen denies it was his intent to write a feminist play. It aroused a great sensation at the time, and caused a "storm of outraged controversy" that went beyond the theatre to the world newspapers and society.
In 2006, the centennial of Ibsen's death, "A Doll's House" held the distinction of being the world's most performed play that year. UNESCO has inscribed Ibsen's autographed manuscripts of "A Doll's House" on the Memory of the World Register in 2001, in recognition of their historical value.
The title of the play is most commonly translated as "A Doll's House", though some scholars use "A Doll House". John Simon says that "A Doll's House" is "the British term for what [Americans] call a 'dollhouse'". Egil Törnqvist says of the alternative title: "Rather than being superior to the traditional rendering, it simply sounds more idiomatic to Americans."
The play opens at Christmas time as Nora Helmer enters her home carrying many packages. Nora's husband Torvald is working in his study when she arrives. He playfully rebukes her for spending so much money on Christmas gifts, calling her his "little squirrel." He teases her about how the previous year she had spent weeks making gifts and ornaments by hand because money was scarce. This year Torvald is due a promotion at the bank where he works, so Nora feels that they can let themselves go a little. The maid announces two visitors: Mrs. Kristine Linde, an old friend of Nora's, who has come seeking employment; and Dr. Rank, a close friend of the family, who is let into the study. Kristine has had a difficult few years, ever since her husband died leaving her with no money or children. Nora says that things have not been easy for them either: Torvald became sick, and they had to travel to Italy so he could recover. Kristine explains that when her mother was ill she had to take care of her brothers, but now that they are grown she feels her life is "unspeakably empty." Nora promises to talk to Torvald about finding her a job. Kristine gently tells Nora that she is like a child. Nora is offended, so she teases the idea that she got money from "some admirer," so they could travel to Italy to improve Torvald's health. She told Torvald that her father gave her the money, but in fact she managed to illegally borrow it without his knowledge because women couldn't do anything economical like signing checks without their husband. Over the years, she has been secretly working and saving up to pay it off.
Krogstad, a lower-level employee at Torvald's bank, arrives and goes into the study. Nora is clearly uneasy when she sees him. Dr. Rank leaves the study and mentions that he feels wretched, though like everyone he wants to go on living. In contrast to his physical illness, he says that the man in the study, Krogstad, is "morally diseased."
After the meeting with Krogstad, Torvald comes out of the study. Nora asks him if he can give Kristine a position at the bank and Torvald is very positive, saying that this is a fortunate moment, as a position has just become available. Torvald, Kristine, and Dr. Rank leave the house, leaving Nora alone. The nanny returns with the children and Nora plays with them for a while until Krogstad creeps through the ajar door, into the living room, and surprises her. Krogstad tells Nora that Torvald intends to fire him at the bank and asks her to intercede with Torvald to allow him to keep his job. She refuses, and Krogstad threatens to blackmail her about the loan she took out for the trip to Italy; he knows that she obtained this loan by forging her father's signature after his death. Krogstad leaves and when Torvald returns, Nora tries to convince him not to fire Krogstad. Torvald refuses to hear her pleas, explaining that Krogstad is a liar and a hypocrite and that years before he had committed a crime: he forged other people’s signatures. Torvald feels physically ill in the presence of a man "poisoning his own children with lies and dissimulation."
Kristine arrives to help Nora repair a dress for a costume function that she and Torvald plan to attend the next day. Torvald returns from the bank, and Nora pleads with him to reinstate Krogstad, claiming she is worried Krogstad will publish libelous articles about Torvald and ruin his career. Torvald dismisses her fears and explains that, although Krogstad is a good worker and seems to have turned his life around, he must be fired because he is too familial around Torvald in front of other bank personnel. Torvald then retires to his study to work.
Dr. Rank, the family friend, arrives. Nora asks him for a favor, but Rank responds by revealing that he has entered the terminal stage of his disease and that he has always been secretly in love with her. Nora tries to deny the first revelation and make light of it but is more disturbed by his declaration of love. She then clumsily attempts to tell him that she is not in love with him, but loves him dearly as a friend.
Having been fired by Torvald, Krogstad arrives at the house. Nora convinces Dr. Rank to go into Torvald's study so he will not see Krogstad. When Krogstad confronts Nora, he declares that he no longer cares about the remaining balance of Nora's loan, but that he will instead preserve the associated bond to blackmail Torvald into not only keeping him employed but also promoting him. Nora explains that she has done her best to persuade her husband, but he refuses to change his mind. Krogstad informs Nora that he has written a letter detailing her crime (forging her father's signature of surety on the bond) and put it in Torvald's mailbox, which is locked.
Nora tells Kristine of her difficult situation. She gives her Krogstad's card with his address, and asks her to try to convince him to relent.
Torvald enters and tries to retrieve his mail, but Nora distracts him by begging him to help her with the dance she has been rehearsing for the costume party, feigning anxiety about performing. She dances so badly and acts so childishly that Torvald agrees to spend the whole evening coaching her. When the others go to dinner, Nora stays behind for a few minutes and contemplates killing herself.
Kristine tells Krogstad that she only married her husband because she had no other means to support her sick mother and young siblings and that she has returned to offer him her love again. She believes that he would not have stooped to unethical behavior if he had not been devastated by her abandonment and been in dire financial straits. Krogstad changes his mind and offers to take back his letter from Torvald. However, Kristine decides that Torvald should know the truth for the sake of his and Nora's marriage.
After Torvald literally dragging Nora home from the party, Dr. Rank follows them. They chat for a while, with Dr. Rank conveying obliquely to Nora that this is a final goodbye, as he has determined that his death is near. Dr. Rank leaves, and Torvald retrieves his letters. As he reads them, Nora prepares to run away for good, but Torvald confronts her with Krogstad's letter. Enraged, he declares that he is now completely in Krogstad's power; he must yield to Krogstad's demands and keep quiet about the whole affair. He berates Nora, calling her a dishonest and immoral woman and telling her that she is unfit to raise their children. He says that from now on their marriage will be only a matter of appearances.
A maid enters, delivering a letter to Nora. The letter is from Krogstad, yet Torvald demands to read the letter and takes it from Nora. Torvald exults that he is saved, as Krogstad has returned the incriminating bond, which Torvald immediately burns along with Krogstad's letters. He takes back his harsh words to his wife and tells her that he forgives her. Nora realizes that her husband is not the strong and gallant man she thought he was, and that he truly loves himself more than he does Nora.
Torvald explains that when a man has forgiven his wife, it makes him love her all the more since it reminds him that she is totally dependent on him, like a child. He preserves his peace of mind by thinking of the incident as a mere mistake that she made owing to her foolishness, one of her most endearing feminine traits.
Nora tells Torvald that she is leaving him, and in a confrontational scene expresses her sense of betrayal and disillusionment. She says he has never loved her, they have become strangers to each other. She feels betrayed by his response to the scandal involving Krogstad, and she says she must get away to understand herself. She says that she has been treated like a doll to play with for her whole life, first by her father and then by him. Torvald insists that she fulfill her duty as a wife and mother, but Nora says that she has duties to herself that are just as important, and that she cannot be a good mother or wife without learning to be more than a plaything. She reveals that she had expected that he would want to sacrifice his reputation for hers and that she had planned to kill herself to prevent him from doing so. She now realizes that Torvald is not at all the kind of person she had believed him to be and that their marriage has been based on mutual fantasies and misunderstandings.
Nora leaves her keys and wedding ring; Torvald breaks down and begins to cry, baffled by what has happened. After Nora leaves the room, Torvald, for one second, still has a sense of hope, and exclaims to himself "The most wonderful thing of all--?", just before the door downstairs is heard closing.
Ibsen's German agent felt that the original ending would not play well in German theatres. In addition, copyright laws of the time would not preserve Ibsen's original work. Therefore, for it to be considered acceptable, and prevent the translator from altering his work, Ibsen was forced to write an alternative ending for the German premiere. In this ending, Nora is led to her children after having argued with Torvald. Seeing them, she collapses, and as the curtain is brought down, it is implied that she stays. Ibsen later called the ending a disgrace to the original play and referred to it as a "barbaric outrage". Virtually all productions today use the original ending, as do nearly all of the film versions of the play.
"A Doll's House" was based on the life of Laura Kieler (maiden name Laura Smith Petersen), a good friend of Ibsen. Much that happened between Nora and Torvald happened to Laura and her husband, Victor. Similar to the events in the play, Laura signed an illegal loan to save her husband. She wanted the money to find a cure for her husband's tuberculosis. She wrote to Ibsen, asking for his recommendation of her work to his publisher, thinking that the sales of her book would repay her debt. At his refusal, she forged a check for the money. At this point she was found out. In real life, when Victor discovered about Laura's secret loan, he divorced her and had her committed to an asylum. Two years later, she returned to her husband and children at his urging, and she went on to become a well-known Danish author, living to the age of 83.
Ibsen wrote "A Doll's House" at the point when Laura Kieler had been committed to the asylum, and the fate of this friend of the family shook him deeply, perhaps also because Laura had asked him to intervene at a crucial point in the scandal, which he did not feel able or willing to do. Instead, he turned this life situation into an aesthetically shaped, successful drama. In the play, Nora leaves Torvald with head held high, though facing an uncertain future given the limitations single women faced in the society of the time.
Kieler eventually rebounded from the shame of the scandal and had her own successful writing career while remaining discontented with sole recognition as "Ibsen's Nora" years afterwards.
Ibsen started thinking about the play around May 1878, although he did not begin its first draft until a year later, having reflected on the themes and characters in the intervening period (he visualised its protagonist, Nora, for instance, as having approached him one day wearing "a blue woolen dress"). He outlined his conception of the play as a "modern tragedy" in a note written in Rome on 19 October 1878. "A woman cannot be herself in modern society," he argues, since it is "an exclusively male society, with laws made by men and with prosecutors and judges who assess feminine conduct from a masculine standpoint!"
Ibsen sent a fair copy of the completed play to his publisher on 15 September 1879. It was first published in Copenhagen on 4 December 1879, in an edition of 8,000 copies that sold out within a month; a second edition of 3,000 copies followed on 4 January 1880, and a third edition of 2,500 was issued on 8 March.
"A Doll's House" received its world premiere on 21 December 1879 at the Royal Theatre in Copenhagen, with Betty Hennings as Nora, Emil Poulsen as Torvald, and Peter Jerndorff as Dr. Rank. Writing for the Norwegian newspaper "Folkets Avis", the critic Erik Bøgh admired Ibsen's originality and technical mastery: "Not a single declamatory phrase, no high dramatics, no drop of blood, not even a tear." Every performance of its run was sold out. Another production opened at the Royal Theatre in Stockholm, on 8 January 1880, while productions in Christiania (with Johanne Juell as Nora and Arnoldus Reimers as Torvald) and Bergen followed shortly after.
In Germany, the actress Hedwig Niemann-Raabe refused to perform the play as written, declaring, ""I" would never leave "my" children!" Since the playwright's wishes were not protected by copyright, Ibsen decided to avoid the danger of being rewritten by a lesser dramatist by committing what he called a "barbaric outrage" on his play himself and giving it an alternative ending in which Nora did not leave. A production of this version opened in Flensburg in February 1880. This version was also played in Hamburg, Dresden, Hanover, and Berlin, although, in the wake of protests and a lack of success, Niemann-Raabe eventually restored the original ending. Another production of the original version, some rehearsals of which Ibsen attended, opened on 3 March 1880 at the Residenz Theatre in Munich.
In Great Britain, the only way in which the play was initially allowed to be given in London was in an adaptation by Henry Arthur Jones and Henry Herman called "Breaking a Butterfly". This adaptation was produced at the Princess Theatre, 3 March 1884. Writing in 1896 in his book "The Foundations of a National Drama", Jones says: "A rough translation from the German version of A Doll's House was put into my hands, and I was told that if it could be turned into a sympathetic play, a ready opening would be found for it on the London boards. I knew nothing of Ibsen, but I knew a great deal of Robertson and H. J. Byron. From these circumstances came the adaptation called "Breaking a Butterfly"." H. L. Mencken writes that it was "A Doll's House" "denaturized and dephlogisticated. … Toward the middle of the action Ibsen was thrown to the fishes, and Nora was saved from suicide, rebellion, flight and immortality by making a faithful old clerk steal her fateful promissory note from Krogstad's desk. … The curtain fell upon a happy home."
Before 1899 there were two private productions of the play in London (in its original form as Ibsen wrote it) — one featured George Bernard Shaw in the role of Krogstad. The first public British production of the play in its regular form opened on 7 June 1889 at the Novelty Theatre, starring Janet Achurch as Nora and Charles Charrington as Torvald. Achurch played Nora again for a 7-day run in 1897. Soon after its London premiere, Achurch brought the play to Australia in 1889.
The play was first seen in America in 1883 in Louisville, Kentucky; Helena Modjeska acted Nora. The play made its Broadway premiere at the Palmer's Theatre on 21 December 1889, starring Beatrice Cameron as Nora Helmer. It was first performed in France in 1894.
Other productions in the United States include one in 1902 starring Minnie Maddern Fiske, a 1937 adaptation with acting script by Thornton Wilder and starring Ruth Gordon, and a 1971 production starring Claire Bloom.
A new translation by Zinnie Harris at the Donmar Warehouse, starring Gillian Anderson, Toby Stephens, Anton Lesser, Tara FitzGerald and Christopher Eccleston opened in May 2009.
The play was performed by in March 2011, one of their early performances following their December 2010 lower Manhattan launch.
In August 2013, Young Vic, London, Great Britain, produced a new adaptation of "A Doll's House" directed by Carrie Cracknell based on the English language version by Simon Stephens.
In September 2014, in partnership with Brisbane Festival, La Boite located in Brisbane, Australia, hosted an adaptation of "A Doll's House" written by Lally Katz and directed by Stephen Mitchell Wright.
In June 2015, Space Arts Centre in London staged an adaptation of "A Doll's House" featuring the discarded alternate ending.
'Manaveli' Toronto staged a Tamil version of "A Doll's House" (ஒரு பொம்மையின் வீடு)on 30 June 2018,Translated and Directed by Mr P Wikneswaran. The drama was very well received by the Tamil Community in Toronto and was staged again in few months later. The same stage play was filmed at the beginning of 2019 and screened in Toronto on 4 May 2019. The film was received with very good reviews and the artists were hailed for their performance. Now, arrangements are being made to screen the film, ஒரு பொம்மையின் வீடு, in London, at Safari Cinema Harrow, on 7 July 2019;
From September 2019 to October 2019 the Lyric Hammersmith in London hosted a new adaptation of the play by Tanika Gupta who moved the setting of the play to colonial India. Though the plot largely remained unchanged, the protagonists were renamed Tom and Niru Helmer and a conversation was added regarding the British oppression of the Indian public. One significant shift was the lack of a slamming door at the end of the play. They also published a pack of teaching materials which includes extracts from the adapted play script.
A production of "A Doll's House" by The Jamie Lloyd Company starring Jessica Chastain was initially scheduled to play at the Playhouse Theatre in London in the summer of 2020. Due to the coronavirus pandemic, the play is now postponed with no set date.
"A Doll's House" questions the traditional roles of men and women in 19th-century marriage. To many 19th-century Europeans, this was scandalous. The covenant of marriage was considered holy, and to portray it as Ibsen did was controversial. However, the Irish playwright George Bernard Shaw found Ibsen's willingness to examine society without prejudice exhilarating.
The Swedish playwright August Strindberg criticised the play in his volume of essays and short stories "Getting Married" (1884). Strindberg questioned Nora's walking out and leaving her children behind with a man that she herself disapproved of so much that she would not remain with him. Strindberg also considers that Nora's involvement with an illegal financial fraud that involved Nora forging a signature, all done behind her husband's back, and then Nora's lying to her husband regarding Krogstad's blackmail, are serious crimes that should raise questions at the end of the play, when Nora is moralistically judging her husband. And Strindberg points out that Nora's complaint that she and Torvald "have never exchanged one serious word about serious things," is contradicted by the discussions that occur in act one and two.
The reasons Nora leaves her husband are complex, and various details are hinted at throughout the play. In the last scene, she tells her husband she has been "greatly wronged" by his disparaging and condescending treatment of her, and his attitude towards her in their marriage – as though she were his "doll wife" — and the children in turn have become her "dolls," leading her to doubt her own qualifications to raise her children. She is troubled by her husband's behavior in regard to the scandal of the loaned money. She does not love her husband, she feels they are strangers, she feels completely confused, and suggests that her issues are shared by many women. George Bernard Shaw suggests that she left to begin "a journey in search of self-respect and apprenticeship to life," and that her revolt is "the end of a chapter of human history."
Ibsen was inspired by the belief that "a woman cannot be herself in modern society," since it is "an exclusively male society, with laws made by men and with prosecutors and judges who assess feminine conduct from a masculine standpoint." Its ideas can also be seen as having a wider application: Michael Meyer argued that the play's theme is not women's rights, but rather "the need of every individual to find out the kind of person he or she really is and to strive to become that person." In a speech given to the Norwegian Association for Women's Rights in 1898, Ibsen insisted that he "must disclaim the honor of having consciously worked for the women's rights movement," since he wrote "without any conscious thought of making propaganda," his task having been "the "description of humanity"."
Because of the departure from traditional behavior and theatrical convention involved in Nora's leaving home, her act of slamming the door as she leaves has come to represent the play itself. In "Iconoclasts" (1905), James Huneker noted "That slammed door reverberated across the roof of the world."
"A Doll's House" has been adapted for the cinema on many occasions, including: | https://en.wikipedia.org/wiki?curid=3144 |
AIM-7 Sparrow
The AIM-7 Sparrow is an American, medium-range semi-active radar homing air-to-air missile operated by the United States Air Force, United States Navy, and United States Marine Corps, as well as other various air forces and navies. Sparrow and its derivatives were the West's principal beyond visual range (BVR) air-to-air missile from the late 1950s until the 1990s. It remains in service, although it is being phased out in aviation applications in favor of the more advanced AIM-120 AMRAAM.
The early Sparrow was intended primarily for use against larger targets and especially bombers, and had numerous operational limitations in other uses. Against smaller targets, the need to receive a strong reflected radar signal made achieving lock-on at the missile's effective range difficult. As the launching aircraft's own radar needed to be pointed at the target throughout the engagement, this meant that in fighter-vs-fighter combat the enemy fighter would often approach within the range of shorter-range infrared homing missiles while the launching aircraft had to continue flying towards its target. Additionally, early models were only effective against targets at roughly the same or higher altitudes, below which reflections from the ground became a problem.
A number of upgraded Sparrow designs were developed to address these issues. In the early 1970s, the RAF developed a version with an inverse monopulse seeker and improved motor known as Skyflash, while the Italian Air Force introduced the similar Aspide. Both had the ability to be fired at targets below the launching fighter ("look-down, shoot down"), were more resistant to countermeasures, and much more accurate in the terminal phases. This basic concept was then made part of the US Sparrows in the M model (for monopulse) and some of these were later updated as the P model, the last to be produced in the US. Aspides sold to China resulted in the locally produced PL10. The Japan Self-Defense Forces also employ the Sparrow missile, though it is being phased out and replaced by the Mitsubishi AAM-4.
The Sparrow was also used as the basis for a surface-to-air missile, the RIM-7 Sea Sparrow, which is used by a number of navies for air defense of their ships. Fired at low altitude and flying directly at its target through the lower atmosphere, the range of the missile in this role is greatly reduced. With the retirement of the Sparrow in the air-to-air role, a new version of the Sea Sparrow was produced to address this concern, producing the much larger and more capable RIM-162 ESSM.
NATO pilots use the brevity code "Fox One" in radio communication to signal launch of a Semi-Active Radar Homing Missile such as the Sparrow.
Sparrow emerged from a late-1940s United States Navy program to develop a guided rocket weapon for air-to-air use. In 1947 the Navy contracted Sperry to build a beam riding version of a standard HVAR, the standard unguided aerial rocket, under Project Hotshot. The weapon was initially dubbed KAS-1, then AAM-2, and, from 1948 on, AAM-N-2. The airframe was developed by Douglas Aircraft Company. The diameter of the HVAR proved to be inadequate for the electronics, leading Douglas to expand the missile's airframe to diameter. The prototype weapon began unpowered flight-tests in 1947, and made its first aerial interception in 1952.
After a protracted development cycle the initial AAM-N-2 Sparrow entered limited operational service in 1954 with specially modified Douglas F3D Skyknight all-weather carrier night fighters. In 1956, they were joined by the McDonnell F3H-2M Demon and Vought F7U Cutlass fighter aircraft. Compared to the modern versions, the Sparrow I was more streamlined and featured a bullet-shaped airframe with a long pointed nose.
Sparrow I was a limited and rather primitive weapon. The limitations of beam-riding guidance (which was slaved to an optical sight on single seater fighters and a radar with night fighters) restricted the missile to attacks against targets flying a straight course and made it essentially useless against a maneuvering target. Only about 2,000 rounds were produced to this standard.
As early as 1950 Douglas examined equipping the Sparrow with an active radar seeker, initially known as XAAM-N-2a "Sparrow II, the original retroactively becoming Sparrow I". In 1952 it was given the new code AAM-N-3. The active radar made the Sparrow II a "fire and forget" weapon, allowing several to be fired at separate targets at the same time.
By 1955 Douglas proposed going ahead with development, intending it to be the primary weapon for the F5D Skylancer interceptor. It was later selected, with some controversy, to be the primary weapon for the Canadian Avro Arrow supersonic interceptor, along with the new Astra fire-control system. For Canadian use and as a second source for US missiles, Canadair was selected to build the missiles in Quebec.
The small size of the missile forebody and the K-band AN/APQ-64-radar limited performance, and it was never able to work in testing. After considerable development and test firings in the U.S. and Canada, Douglas abandoned development in 1956. Canadair continued development until the Arrow was cancelled in 1959.
A subvariant of the Sparrow I armed with the same nuclear warhead as the MB-1 Genie was proposed in 1958, but was cancelled shortly thereafter.
Concurrently with the development of the Sparrow I, in 1951, Raytheon began work on the semi-active radar homing version of Sparrow family of missiles, the AAM-N-6 "Sparrow III". The first of these weapons entered United States Navy service in 1958.
The AAM-N-6a was similar to the -6, but used a new Thiokol liquid-fuel rocket engine for improved performance. It also included changes to the guidance electronics to make it effective at higher closing speeds. The -6a was also selected to arm the Air Force's "F-110A Spectre" (F-4 Phantom) fighters in 1962, known to them as the AIM-101. It entered production in 1959, with 7500 being built.
Another upgrade reverted to a Rocketdyne solid-fuel motor for the AAM-N-6b, which started production in 1963. The new motor significantly increased maximum range to for head-on attacks.
During this year the Air Force and Navy agreed on standardized naming conventions for their missiles. The Sparrows became the AIM-7 series. The original Sparrow I and aborted Sparrow II became the AIM-7A and AIM-7B, despite both being out of service. The -6, -6a, and -6B became the AIM-7C, AIM-7D, and AIM-7E respectively.
25,000 AIM-7Es were produced, and saw extensive use during the Vietnam War, where its performance was generally considered disappointing. The mixed results were a combination of reliability problems (exacerbated by the tropical climate), limited pilot training in fighter-to-fighter combat, and restrictive rules of engagement that generally prohibited BVR (beyond visual range) engagements. The Pk (kill probability) of the AIM-7E was less than 10%; US fighter pilots shot down 59 aircraft out of the 612 Sparrows fired. Of the 612 AIM-7D/E/E-2 missiles fired, 97 (or 15.8%) hit their targets, resulting in 56 (or 9.2%) kills. Two kills were obtained beyond visual range.
In 1969 an improved version, the E-2, was introduced with clipped wings and various changes to the fuzing. Considered a "dogfight Sparrow", the AIM-7E-2 was intended to be used at shorter ranges where the missile was still travelling at high speeds, and in the head-on aspect, making it much more useful in the visual limitations imposed on the engagements. Even so, its kill rate was only 13% in combat, leading to a practice of ripple-firing all four at once in hopes of increasing kill probability. Its worst tendency was that of detonating prematurely, approximately a thousand feet in front of the launching aircraft, but it also had many motor failures, erratic flights, and fuzing problems. An E-3 version included additional changes to the fuzing, and an E-4 featured a modified seeker for use with the F-14 Tomcat.
Improved versions of the AIM-7 were developed in the 1970s in an attempt to address the weapon's limitations. The AIM-7F, which entered service in 1976, had a dual-stage rocket motor for longer range, solid-state electronics for greatly improved reliability, and a larger warhead. Even this version had room for improvement, leading British Aerospace and the Italian firm Alenia to develop advanced versions of Sparrow with better performance and improved electronics as the BAe Skyflash and Alenia Aspide, respectively.
The most common version of the Sparrow today, the AIM-7M, entered service in 1982 and featured a new inverse monopulse seeker (matching the capabilities of Skyflash), active radar proximity fuse, digital controls, improved ECM resistance, and better low-altitude performance. It was used to good advantage in the 1991 Gulf War, where it scored many USAF air-to-air kills. Of 44 missiles fired, 30 (68.2%) hit their intended targets resulting in 24/26 (54.5%/59.1%) kills. 19 kills were obtained beyond visual range.
The AIM-7P is similar in most ways to the M versions, and was primarily an upgrade program for existing M-series missiles. The main changes were to the software, improving low-level performance. A follow-on Block II upgrade added a new rear receiver allowing the missile to receive mid-course correction from the launching aircraft. Plans initially called for all M versions to be upgraded, but currently P's are being issued as required to replace M's lost or removed from the inventory.
The final version of the missile was to have been the AIM-7R, which added an infrared homing seeker to an otherwise unchanged AIM-7P Block II. A general wind-down of the budget led to it being cancelled in 1997.
Sparrow is now being phased out with the availability of the active-radar AIM-120 AMRAAM, but is likely to remain in service for several years.
As part of the Avro Canada CF-105 Arrow program, Canadair (now Bombardier) partnered with Douglas Aircraft Company in the development of the Sparrow II (AAM-N-3/AIM-7B). After Douglas dropped out of this program, Canadair continued on with it until the termination of the Arrow project.
The AAM-N-3 Sparrow II was unique in that it had a fully active radar guidance system. This combined both a radar transmitter and receiver in the missile, making it unnecessary for the pilot to keep the aircraft aimed at the target after firing the missile, unlike Semi-active radar homing (SARH) missiles which require continuous radar-assisted guidance throughout flight. This allowed the aircraft that fired the AAM-N-3 to turn away, prosecute other targets, and/or escape from potential retaliatory missiles fired by the enemy aircraft during the time it takes for the Sparrow to reach its target. Despite the significant advantages of this design over SARH guidance, all subsequent models of the Sparrow use semi-active radar homing.
To accommodate the active radar guidance system, the AAM-N-3 Sparrow II had a much greater volume than its predecessor. Its size would subsequently set the precedent for all future Sparrow variants.
In 1959, Canadair had completed five missiles based on airframes from Douglas, and built two models from scratch, when the program was cancelled with the cancellation of the Arrow.
Skyguard I is an anti-aircraft system, utilizing ground-based AIM-7 Sparrow launchers.
The Italian company Finmeccanica (now Leonardo S.p.A.), Alenia Difesa licensed the AIM-7E Sparrow technology from the US, and produced its own improved version called Aspide.
The LY-60/FD-60/PL-10 is a family of PRC missiles developed by the Shanghai Academy of Science and Technology, largely based on the Italian Aspide missile – a version of the Sparrow. There are four versions of the basic design, three of which are surface-to-air and one air-to-air.
The Soviet Union acquired an AIM-7 in 1968 and a Vympel team started copying it as the K-25. The missile did not enter production as the R-23 was thought to have better versatility, range, signal processing logic, and immunity from interference. K-25 work ended in 1971, but analysis of the Sparrow was later used to inform the design of the Vympel R-27, particularly the servomechanisms and movable wings.
British Aerospace (BAe) licensed the AIM-7E2 technology in the 1970s, producing the Skyflash missile. Skyflash used a Marconi XJ521 monopulse Semi-Active seeker together with improvements to the electronics. It was powered by the Aerojet Mk52 mod 2 rocket engine (later by the Rocketdyne Mk38 mod 4). Skyflash entered service with the Royal Air Force (RAF) on their Phantom FG.1/FGR.2 in 1978, and later on the Tornado F3. Skyflash was also exported to Sweden for use on their Viggen fighters.
An upgraded version with active radar seeker, called Active Sky Flash was proposed by BAe and Thomson-CSF, but did not receive funding because the RAF opted for other missiles.
The Sparrow has four major sections: guidance section, warhead, control, and rocket motor (currently the Hercules MK-58 solid-propellant rocket motor). It has a cylindrical body with four wings at mid-body and four tail fins. Although the external dimensions of the Sparrow remained relatively unchanged from model to model, the internal components of newer missiles represent major improvements, with vastly increased capabilities. The warhead is of the continuous-rod type.
As with other semi-active radar guided missiles, the missile does not generate radar signals, but instead homes in on reflected continuous-wave signals from the launch platform's radar. The receiver also senses the guidance radar to enable comparisons that enhance the missile's resistance to passive jamming.
The launching aircraft will illuminate the target with its radar. In radars of the 1950s these were single target tracking devices using a nutating horn as part of the antenna. This caused the beam to be swept in a small cone. Signal processing would be applied to determine the direction of maximum illumination and so develop a signal to steer the antenna toward the target. The missile detects the reflected signal from the target with a high gain antenna in a similar fashion and steers the entire missile toward closure with the target. The missile guidance also samples a portion of the illuminating signal via rearward pointing waveguides. The comparison of these two signals enabled logic circuits to determine the true target reflection signal, even if the target were to eject radar-reflecting chaff. | https://en.wikipedia.org/wiki?curid=3146 |
AIM-120 AMRAAM
The AIM-120 Advanced Medium-Range Air-to-Air Missile, or AMRAAM (pronounced ), is an American beyond-visual-range air-to-air missile (BVRAAM) capable of all-weather day-and-night operations. Designed with a 7-inch (180mm) diameter form-and-fit factor, and employing active transmit-receive radar guidance instead of semi-active receive-only radar guidance, it has the advantage of being a fire-and-forget weapon when compared to the previous generation Sparrow missiles. When an AMRAAM missile is launched, NATO pilots use the brevity code Fox Three.
The AMRAAM is the world's most popular beyond-visual-range missile, and more than 14,000 have been produced for the United States Air Force, the United States Navy, and 33 international customers. The AMRAAM has been used in several engagements and is credited with ten air-to-air kills. Now over 30 years old in design, the AMRAAM is due to be replaced by the new AIM-260 JATM, which will offer better long-range performance and ability to defeat electronic warfare jamming.
The AIM-7 Sparrow medium range missile (MRM) was purchased by the US Navy from original developer Hughes Aircraft in the 1950s as its first operational air-to-air missile with "beyond visual range" (BVR) capability. With an effective range of about , it was introduced as a radar beam-riding missile and then it was improved to a semi-active radar guided missile which would home in on reflections from a target illuminated by the radar of the launching aircraft. It was effective at visual to beyond visual range. The early beam riding versions of the Sparrow missiles were integrated onto the F3H Demon and F7U Cutlass, but the definitive AIM-7 Sparrow was the primary weapon for the all-weather F-4 Phantom II fighter/interceptor, which lacked an internal gun in its U.S. Navy, U.S. Marine Corps, and early U.S. Air Force versions. The F-4 carried up to four AIM-7s in built-in recesses under its belly.
Although designed for use against non-maneuvering targets such as bombers, because of poor performance against fighters over North Vietnam, these missiles were progressively improved until they proved highly effective in dogfights. Together with the short-range, infrared-guided AIM-9 Sidewinder, they replaced the AIM-4 Falcon IR and radar guided series for use in air combat by the USAF as well. A disadvantage to semi-active homing was that only one target could be illuminated by the launching fighter plane at a time. Also, the launching aircraft had to remain pointed in the direction of the target (within the azimuth and elevation of its own radar set) which could be difficult or dangerous in air-to-air combat.
An active-radar variant called the Sparrow II was developed to address these drawbacks, but the U.S. Navy pulled out of the project in 1956. The Royal Canadian Air Force, which took over development in the hopes of using the missile to arm their prospective CF-105 Arrow interceptor, soon followed in 1958. The electronics of the time simply could not be miniaturized enough to make Sparrow II a viable working weapon. It would take decades, and a new generation of digital electronics, to produce an effective active-radar air-to-air missile as compact as the Sparrow.
The US Navy later developed the AIM-54 Phoenix long-range missile (LRM) for the fleet air defense mission. It was a large , Mach 5 missile designed to counter cruise missiles and the bombers that launched them. Originally intended for the straight-wing Douglas F6D Missileer and then the navalized version of the F-111B, it finally saw service with the Grumman F-14 Tomcat, the only fighter capable of carrying such a heavy missile. Phoenix was the first US fire-and-forget, multiple-launch, radar-guided missile: one which used its own active guidance system to guide itself without help from the launch aircraft when it closed on its target. This, in theory, gave a Tomcat with a six-Phoenix load the unprecedented capability of tracking and destroying up to six targets beyond visual range, as far as away—the only US fighter with such capability.
A full load of six Phoenix missiles and its dedicated launcher exceeded a typical Vietnam-era bomb load. Its service in the US Navy was primarily as a deterrent, as its use was hampered by restrictive rules of engagement in conflicts such as Operations Desert Storm, Southern Watch, and Iraqi Freedom. The US Navy retired the Phoenix in 2004 in light of availability of the AIM-120 AMRAAM on the F/A-18 Hornet and the pending retirement of the F-14 Tomcat from active service in late 2006.
The Department of Defense conducted an extensive evaluation of air combat tactics and missile technology from 1974 to 1978 at Nellis AFB using the F-14 Tomcat and F-15 Eagle equipped with Sparrow and Sidewinder missiles as the blue force and aggressor F-5E aircraft equipped with AIM-9L all-aspect Sidewinders as the red force. This joint test and evaluation (JT&E) was designated Air Combat Evaluation/Air Intercept Missile Evaluation (ACEVAL/AIMVAL). A principal finding was that the necessity to produce illumination for the Sparrow until impact resulted in the red force's being able to launch their all-aspect Sidewinders before impact, resulting in mutual kills. What was needed was Phoenix-type multiple-launch and terminal active capability in a Sparrow-size airframe. This led to a memorandum of agreement (MOA) with European allies (principally the UK and Germany for development) for the US to develop an advanced, medium-range, air-to-air missile with the USAF as lead service. The MOA also assigned responsibility for development of an advanced, short-range, air-to-air missile to the European team; this would become the British ASRAAM.
By the 1990s, the reliability of the Sparrow had improved so much from the dismal days of Vietnam that it accounted for the largest number of aerial targets destroyed in Desert Storm. But while the USAF had passed on the Phoenix and their own similar AIM-47/YF-12 to optimize dogfight performance, they still needed a multiple-launch fire-and-forget capability for the F-15 and F-16. AMRAAM would need to be fitted on fighters as small as the F-16, and fit in the same spaces that were designed to fit the Sparrow on the F-4 Phantom. The European partners needed AMRAAM to be integrated on aircraft as small as the Sea Harrier. The US Navy needed AMRAAM to be carried on the F/A-18 Hornet and wanted capability for two to be carried on a launcher that normally carried one Sparrow to allow for more air-to-ground weapons.
The AMRAAM became one of the primary air-to-air weapons of the new F-22 Raptor fighter, which needed to place all of its weapons into internal weapons bays in order to help achieve an extremely low radar cross-section.
AMRAAM was developed as the result of an agreement (the Family of Weapons MOA, no longer in effect by 1990), among the United States and several other NATO nations to develop air-to-air missiles and to share production technology. Under this agreement the U.S. was to develop the next generation medium range missile (AMRAAM) and Europe would develop the next generation short range missile (ASRAAM). Although Europe initially adopted the AMRAAM, an effort to develop the Meteor, a competitor to AMRAAM, was begun in Great Britain. Eventually the ASRAAM was developed solely by the British, but using another source for its infrared seeker. After protracted development, the deployment of AMRAAM (AIM-120A) began in September 1991 in US Air Force F-15 Eagle fighter squadrons. The US Navy soon followed (in 1993) in its F/A-18 Hornet squadrons.
The Russian Air Force counterpart of AMRAAM is the somewhat similar R-77 (NATO codename AA-12 Adder), sometimes referred to in the West as the "AMRAAMski" Likewise, France began its own air-to-air missile development with the MICA concept that used a common airframe for separate radar-guided and infrared-guided versions.
AMRAAM has an all-weather, beyond-visual-range (BVR) capability. It improves the aerial combat capabilities of US and allied aircraft to meet the threat of enemy air-to-air weapons as they existed in 1991. AMRAAM serves as a follow-on to the AIM-7 Sparrow missile series. The new missile is faster, smaller, and lighter, and has improved capabilities against low-altitude targets. It also incorporates a datalink to guide the missile to a point where its active radar turns on and makes terminal intercept of the target. An inertial reference unit and micro-computer system makes the missile less dependent upon the fire-control system of the aircraft.
Once the missile closes in on the target, its active radar guides it to intercept. This feature, known as "fire-and-forget", frees the aircrew from the need to further provide guidance, enabling the aircrew to aim and fire several missiles simultaneously at multiple targets and break a radar lock after the missile seeker goes active and guide themselves to the targets.
The missile also features the ability to "Home on Jamming," giving it the ability to switch over from active radar homing to passive homing – homing on jamming signals from the target aircraft. Software on board the missile allows it to detect if it is being jammed, and guide on its target using the proper guidance system.
AMRAAM uses two-stage guidance when fired at long range. The aircraft passes data to the missile just before launch, giving it information about the location of the target aircraft from the launch point and its direction and speed. The missile uses this information to fly on an interception course to the target using its built-in inertial navigation system (INS). This information is generally obtained using the launching aircraft's radar, although it could come from an infra-red search and track system, from a data link from another fighter aircraft, or from an AWACS aircraft.
After launch, if the firing aircraft or surrogate continues to track the target, periodic updates—such as changes in the target's direction and speed—are sent from the launch aircraft to the missile, allowing the missile to adjust its course, via actuation of the rear fins, so that it is able to close to a self-homing distance where it will be close enough to "catch" the target aircraft in the "basket" (the missile's radar field of view in which it will be able to lock onto the target aircraft, unassisted by the launch aircraft).
Not all armed services using the AMRAAM have elected to purchase the mid-course update option, which limits AMRAAM's effectiveness in some scenarios. The RAF initially opted not to use mid-course update for its Tornado F3 force, only to discover that without it, testing proved the AMRAAM was less effective in beyond visual range (BVR) engagements than the older semi-active radar homing BAE Skyflash weapon—the AIM-120's own radar is necessarily of limited range and power compared to that of the launch aircraft.
Once the missile closes to self-homing distance, it turns on its active radar seeker and searches for the target aircraft. If the target is in or near the expected location, the missile will find it and guide itself to the target from this point. If the missile is fired at short range, within visual range (WVR) or the near BVR, it can use its active seeker just after launch to guide it to intercept.
Apart from the radar-slaved mode, there is a free guidance mode, called "Visual". This mode is radar guidance-free—the missile just fires and locks onto the first thing it sees. This mode can be used for defensive shots, i.e. when the enemy has numerical superiority.
The kill probability (Pk) is determined by several factors, including aspect (head-on interception, side-on or tail-chase), altitude, the speed of the missile and the target, and how hard the target can turn. Typically, if the missile has sufficient energy during the terminal phase, which comes from being launched at close range to the target from an aircraft with an altitude and speed advantage, it will have a good chance of success. This chance drops as the missile is fired at longer ranges as it runs out of overtake speed at long ranges, and if the target can force the missile to turn it might bleed off enough speed that it can no longer chase the target. Operationally, the missile, which was designed for beyond visual range combat, has a Pk of 63.15% (19 missiles for 12 kills, including the Syrian Su-22 downed by a US Navy F/A-18E). The targets included six MiG-29s, a MiG-25, a MiG-23, two Su-22s, a Galeb and a US Army Blackhawk that was targeted by mistake.
There are currently four main variants of AMRAAM, all in service with the United States Air Force, United States Navy, and the United States Marine Corps. The AIM-120A is no longer in production and shares the enlarged wings and fins with the successor AIM-120B. The AIM-120C has smaller "clipped" aerosurfaces to enable internal carriage on the USAF F-22 Raptor. AIM-120B deliveries began in 1994.
The AIM-120C deliveries began in 1996. The C-variant has been steadily upgraded since it was introduced. The AIM-120C-6 contained an improved fuse (Target Detection Device) compared to its predecessor. The AIM-120C-7 development began in 1998 and included improvements in homing and greater range (actual amount of improvement unspecified). It was successfully tested in 2003 and is currently being produced for both domestic and foreign customers. It helped the U.S. Navy replace the F-14 Tomcats with F/A-18E/F Super Hornets – the loss of the F-14's long-range AIM-54 Phoenix missiles (already retired) is offset with a longer-range AMRAAM-D. The lighter weight of the advanced AMRAAM enables an F/A-18E/F pilot greater bring-back weight upon carrier landings.
The AIM-120D is an upgraded version of the AMRAAM with improvements in almost all areas, including 50% greater range (than the already-extended range AIM-120C-7) and better guidance over its entire flight envelope yielding an improved kill probability (Pk). Raytheon began testing the D model on August 5, 2008, the company reported that an AIM-120D launched from an F/A-18F Super Hornet passed within lethal distance of a QF-4 target drone at the White Sands Missile Range. The range of the AIM-120D is classified, but is thought to extend to about .
The AIM-120D (P3I Phase 4, formerly known as AIM-120C-8) is a development of the AIM-120C with a two-way data link, more accurate navigation using a GPS-enhanced IMU, an expanded no-escape envelope, and improved HOBS (high off-boresight) capability. The AIM-120D max speed is Mach 4 and AIM-120D is a joint USAF/USN project, and is currently in the testing phase. The USN was scheduled to field it from 2014, and AIM-120D will be carried by all Pacific carrier groups by 2020, although the 2013 sequestration cuts could push back this later date to 2022. The Royal Australian Air Force requested 450 AIM-120D missiles, which would make it the first foreign operator of the missile. The procurement, approved by the US Government in April 2016, will cost $1.1 billion and will be integrated for use on the F/A-18F Super Hornet, EA-18G Growler and the F-35 Lightning II aircraft.
There were also plans for Raytheon to develop a ramjet-powered derivative of the AMRAAM, the Future Medium Range Air-Air Missile (FMRAAM). The FMRAAM was not produced since the target market, the British Ministry of Defence, chose the Meteor missile over the FMRAAM for a BVR missile for the Eurofighter Typhoon aircraft.
Raytheon is also working with the Missile Defense Agency to develop the Network Centric Airborne Defense Element (NCADE), an anti-ballistic missile derived from the AIM-120. This weapon will be equipped with a ramjet engine and an infrared homing seeker derived from the Sidewinder missile. In place of a proximity-fused warhead, the NCADE will use a kinetic energy hit-to-kill vehicle based on the one used in the Navy's RIM-161 Standard Missile 3.
The -120A and -120B models are currently nearing the end of their service life while the -120D variant has just entered full production. AMRAAM was due to be replaced by the USAF, the U.S. Navy, and the U.S. Marine Corps after 2020 by the Joint Dual Role Air Dominance Missile (Next Generation Missile), but it was terminated in the 2013 budget plan. Exploratory work was started in 2017 on a replacement called Long-Range Engagement Weapon.
In 2017, work on the AIM-260 Joint Advanced Tactical Missile (JATM) began to create a longer-ranged replacement for the AMRAAM to contend with foreign weapons like the PL-15. Flight tests are planned to begin in 2021 and initial operational capability is slated for 2022, facilitating the end of AMRAAM production by 2026.
Raytheon successfully tested launching AMRAAM missiles from a five-missile carrier on a M1097 Humvee. This system will be known as the SLAMRAAM (Surface Launched (SL) and AMRAAM). They receive their initial guidance information from a radar not mounted on the vehicle. Since the missile is launched without the benefit of an aircraft's speed or high altitude, its range is considerably shorter. Raytheon is currently marketing an SL-AMRAAM EX, purported to be an extended range AMRAAM and bearing a resemblance to the RIM-162 ESSM.
The Norwegian Advanced Surface-to-Air Missile System (NASAMS), developed by Kongsberg Defence & Aerospace, consists of a number of vehicle-pulled launch batteries (containing six AMRAAMs each) along with separate radar trucks and control station vehicles. A more recent version of the program is the "High Mobility Launcher", made in cooperation with Raytheon (Kongsberg Defence & Aerospace was already a subcontractor on the SLAMRAAM system), where the launch-vehicle is a Humvee (M1152A1 HMMWV), containing four AMRAAMs each.
While still under evaluation for replacement of current US Army assets, the SL-AMRAAM has been deployed in several nations' military forces. The United Arab Emirates (UAE) has requested the purchasing of SL-AMRAAM as part of a larger $7 billion foreign military sales package. The sale would include 288 AMRAAM C-7 missiles.
The US Army has test fired the SL-AMRAAM from a HIMARS artillery rocket launcher as a common launcher, as part of a move to switch to a larger and more survivable launch platform.
On January 6, 2011, Secretary of Defense Robert Gates announced that the U.S. Army has decided to terminate acquisition of the SLAMRAAM as part of a budget-cutting effort.
The National Guard Association of the United States has sent a letter asking for the U.S. Senate to stop the Army's plan to drop the SLAMRAAM program because without it there would be no path to modernize the Guard's AN/TWQ-1 Avenger Battalions.
On 22 February 2015, Raytheon announced an Extended Range upgrade to NASAMS-launched AMRAAM, calling it AMRAAM-ER. This combines the AMRAAM seeker with the ESSM rocket motor.
The AMRAAM was used for the first time on December 27, 1992, when a USAF F-16D shot down an Iraqi MiG-25 that violated the southern no-fly-zone. This missile had been returned from the flight line as defective a day earlier. AMRAAM gained a second victory in January 1993 when an Iraqi MiG-23 was shot down by a USAF F-16C.
The third combat use of the AMRAAM was in 1994, when a Republika Srpska Air Force J-21 Jastreb aircraft was shot down by a USAF F-16C that was patrolling the UN-imposed no-fly zone over Bosnia. In that engagement, at least three other Serbian aircraft were shot down by USAF F-16C fighters using AIM-9 missiles (see Banja Luka incident for more details). At that point, three launches in combat had resulted in three kills, resulting in the AMRAAM's being informally named "slammer" in the second half of the 1990s.
In 1998 and 1999 AMRAAMs were again fired by USAF F-15 fighters at Iraqi aircraft violating the No-Fly-Zone, but this time they failed to hit their targets. During spring 1999, AMRAAMs saw their main combat action during Operation Allied Force, the Kosovo bombing campaign. Six Serbian MiG-29 were shot down by NATO (four USAF F-15Cs, one USAF F-16C, and one Dutch F-16A MLU), all of them using AIM-120 missiles (the supposed kill by the F-16C may have actually been friendly fire, an SA-7 MANPADS fired by Serbian infantry).
On 18 June 2017, a US F/A-18E Super Hornet engaged and shot down a Sukhoi Su-22 of the Syrian Air Force over northern Syria, using an AIM-120. The Su-22 had previously avoided an AIM-9X Sidewinder; it was initially thought this was done by using flares, although first-hand account by the F/A-18E pilot, Lt. Cmdr. Michael Tremel, was that the AIM-9X malfunctioned and failed to acquire the target, with no use of flares by the Su-22.
As of 2017, the AIM-120 AMRAAM has shot down eleven aircraft (six MiG-29s, one MiG-25, one MiG-23, one Su-22, one Soko J-21 Jastreb, and one UH-60 Black Hawk). The latter was a friendly fire incident in 1994 when two USAF F-15 fighters patrolling Iraq's Northern No-Fly Zone inadvertently shot down a pair of U.S. Army Black Hawk helicopters, one by an AIM-9 Sidewinder.
On 7 August 2018, a Spanish Air Force Eurofighter Typhoon accidentally launched a missile in Estonia. There were no human casualties, but a ten-day search operation for missile remains was unsuccessful.
On 27 February 2019, Pakistan Air Force downed an Indian Air Force MiG-21 Bison with its F-16s; Indian officials displayed fragments of the alleged AIM-120C-5 missile. Pakistan denies the use of F-16 in this aerial engagement.
On 1 March 2020, during Operation Spring Shield, the Turkish Air Force downed two SU-24s belonging to the Syrian Assad regime using two AIM-120C7s that launched by an F-16.
Canadair, now Bombardier, had largely helped with the development of the AIM-7 Sparrow and Sparrow II, and assisted to a lesser extent in the AIM-120 development. Canada had placed an order for 256 AIM-120's, but cancelled half of them after engine ignition problems due to cold weather conditions. The AIM-9X & AIM-7 were ordered as replacements.
In early 1995 South Korea ordered 88 AIM-120A missiles for its KF-16 fleet. In 1997 South Korea ordered 737 additional AIM-120B missiles.
In 2006 Poland received AIM-120C-5 missiles to arm its new F-16C/D Block 52+ fighters.
In early 2006, the Pakistan Air Force (PAF) ordered 500 AIM-120C-5 AMRAAM missiles as part of a $650 million F-16 ammunition deal to equip its F-16C/D Block 50/52+ and F-16A/B Block 15 MLU fighters. The PAF got the first three F-16C/D Block 50/52+ aircraft on July 3, 2010 and first batch of AMRAAMs on July 26, 2010.
In 2007, the United States government agreed to sell 218 AIM-120C-7 missiles to Taiwan as part of a large arms sales package that also included 235 AGM-65G-2 Maverick missiles. Total value of the package, including launchers, maintenance, spare parts, support and training rounds, was estimated at around US$421 million. This supplemented an earlier Taiwanese purchase of 120 AIM-120C-5 missiles a few years ago.
2008 has brought announcements of new or additional sales to Singapore, Finland, Morocco and South Korea; in December 2010 the Swiss government requested 150 AIM-120C-7 missiles. Sales to Finland have stalled, because the manufacturer has not been able to fix a mysterious bug that causes the rocket motors of the missile to fail in cold tests. In May 5, 2015, the State Department has made a determination approving a possible Foreign Military Sale to Royal Malaysian Air Force for AIM-120C7 AMRAAM missiles and associated equipment, parts and logistical support for an estimated cost of $21 million.
In March 2016, the US government approved the sales of AIM-120C-7 missiles to the Indonesian Air Force to equip their fleet of F-16 C/D Block 52ID. The AIM-120C-7 is also equipped for the upgraded F-16 A/B Block 15 OCU through Falcon Star-eMLU upgrade project.
In March 2019, the US Department of State and Defense Security Cooperation Agency have formally signed-off on a US$240.5 million foreign military sale to support Australia’s introduction of the NASAMS and LAND 19 Phase 7B program. As part of the deal, the Australian government requested up to 108 Raytheon AIM-120C-7 AMRAAM, six AIM-120C-7 AMRAAM Air Vehicles Instrumented; and six spare AIM-120C-7 AMRAAM guidance sections. | https://en.wikipedia.org/wiki?curid=3147 |
AGM-88 HARM
The AGM-88 HARM (High-speed Anti-Radiation Missile) is a tactical, air-to-surface anti-radiation missile designed to home in on electronic transmissions coming from surface-to-air radar systems. It was originally developed by Texas Instruments as a replacement for the AGM-45 Shrike and AGM-78 Standard ARM system. Production was later taken over by Raytheon Corporation when it purchased the defense production business of Texas Instruments.
The AGM-88 can detect, attack and destroy a radar antenna or transmitter with minimal aircrew input. The proportional guidance system that homes in on enemy radar emissions has a fixed antenna and seeker head in the missile's nose. A smokeless, solid-propellant, booster-sustainer rocket motor propels the missile at speeds over Mach 2.0. The HARM missile was a program led by the U.S. Navy, and it was first carried by the A-6E, A-7, and F/A-18A/B aircraft, and then it equipped the EA-6B aircraft. RDT&E for use on the F-14 aircraft was begun, but not completed. The U.S. Air Force (USAF) put the HARM onto the F-4G Wild Weasel aircraft, and later on specialized F-16s equipped with the HARM Targeting System (HTS). The HTS pod, used by the USAF only, allows F-16s to detect and automatically target radar systems with HARMs instead of relying on the missile's sensors alone.
The HARM missile was approved for full production in March 1983, obtained initial operating capability (IOC) on the A-7E Corsair II in late 1983 and then deployed in late 1985 with VA-46 aboard the aircraft carrier USS "America". In 1986, the first successful firing of the HARM from an EA-6B was performed by VAQ-131. It was soon used in combat—in March 1986 against a Libyan SA-5 site in the Gulf of Sidra, and then during Operation Eldorado Canyon in April. HARM was used extensively by the Navy, Marine Corps, and the Air Force in Operation Desert Storm during the Persian Gulf War of 1991.
During the Gulf War, the HARM was involved in a friendly fire incident when the pilot of an F-4G Wild Weasel escorting a B-52 bomber mistook the latter's tail gun radar for an Iraqi AAA site. (This was after the tail gunner of the B-52 had targeted the F-4G, mistaking it for an Iraqi MiG.) The F-4 pilot launched the missile and then saw that the target was the B-52, which was hit. It survived with shrapnel damage to the tail and no casualties. The B-52 was subsequently renamed "In HARM's Way".
"Magnum" is spoken over the radio to announce the launch of an AGM-88. During the Gulf War, if an aircraft was illuminated by enemy radar a bogus "Magnum" call on the radio was often enough to convince the operators to power down.
This technique would also be employed in Serbia during air operations in 1999.
In 2013 President Obama offered the AGM-88 to Israel for the first time.
A newer upgrade, the "AGM-88E Advanced Antiradiation Guided Missile (AARGM)," features the latest software, enhanced capabilities intended to counter enemy radar shutdown, and passive radar using an additional active millimeter-wave seeker. It was released in November 2010, and it is a joint venture by the US Department of Defense and the Italian Ministry of Defense, produced by Orbital ATK.
In November 2005, the Italian Ministry of Defense and the U.S. Department of Defense signed a Memorandum of Agreement on the joint development of the AGM-88E AARGM missile. Italy was providing $20 million of developmental funding as well as several million dollars worth of material, equipment, and related services. The Italian Air Force was expected to buy up to 250 missiles for its Tornado ECR aircraft. A flight test program was set to integrate the AARGM onto Tornado ECR's weapon system.
The U.S. Navy demonstrated the AARGM's capability during Initial Operational Test and Evaluation (IOT&E) in spring 2012 with live firing of 12 missiles. Aircrew and maintenance training with live missiles was completed in June.
The Navy authorized Full-Rate Production (FRP) of the AARGM in August 2012, with 72 missiles for the Navy and nine for the Italian Air Force to be delivered in 2013. A U.S. Marine Corps F/A-18 Hornet squadron will be the first forward-deployed unit with the AGM-88E.
In September 2013, ATK delivered the 100th AARGM to the U.S. Navy. The AGM-88E program is on schedule and on budget, with Full Operational Capability (FOC) planned for September 2014. The AGM-88E was designed to improve the effectiveness of legacy HARM variants against fixed and relocatable radar and communications sites, particularly those that would shut down to throw off anti-radiation missiles, by attaching a new seeker to the existing Mach 2-capable rocket motor and warhead section, adding a passive anti-radiation homing receiver, satellite and inertial navigation system, a millimeter-wave radar for terminal guidance, and the ability to beam up images of the target via a satellite link just seconds before impact.
This model of the HARM will be integrated onto the F/A-18C/D, F/A-18E/F, EA-18G, and Tornado ECR aircraft, and later on the F-35 (externally).
In September 2015, the AGM-88E successfully hit a mobile ship target in a live-fire test, demonstrating the missile's ability to use antiradiation homing and millimeter-wave radar to detect, identify, locate, and engage moving targets.
In December 2019, the German Air Force ordered the AARGM.
Although the US Navy/Marine Corps chose the Orbital ATK-produced AGM-88E AARGM, Raytheon developed its own update of the HARM called the AGM-88F HCSM (HARM Control Section Modification), tested in conjunction with and ultimately for the US Air Force. It incorporates similar upgrade features as the AARGM, and although it is not yet listed for export, existing HARM users have shown interest.
The Navy's FY 2016 budget included funding for an extended range AARGM-ER that uses the existing guidance system and warhead of the AGM-88E with a solid integrated rocket-ramjet for double the range. Development funding will last to 2020. In September 2016, Orbital ATK unveiled its extended-range AARGM-ER, which incorporates a redesigned control section and -diameter rocket motor for twice the range and internal carriage on the Lockheed Martin F-35A and F-35C Lightning II. Internal carriage on the F-35B isn't possible due to internal space limitations. The U.S. Navy awarded Orbital ATK a contract for AARGM-ER development in January 2018. The USAF has formally joined the AARGM-ER program, and is involved in internal F-35A/F-35C integration work.
The AARGM-ER would serve as the basis for the USAF's land-attack Stand in Attack Weapon (SiAW).
In June 2020, the US Navy conducted first captive carry flight test of the AARGM-ER on a Super Hornet at NAS Patuxent River, Maryland to evaluate integration and structural characteristics of the destruction/suppression of enemy air-defences (DEAD/SEAD) air-to-surface missile. | https://en.wikipedia.org/wiki?curid=3149 |
AGM-65 Maverick
The AGM-65 Maverick is an air-to-ground missile (AGM) designed for close air support. It is the most widely produced precision-guided missile in the Western world, and is effective against a wide range of tactical targets, including armor, air defenses, ships, ground transportation and fuel storage facilities.
Development began in 1966 at Hughes as the first missile to use an electronic contrast seeker. It entered service with the United States Air Force in August 1972. Since then, it has been exported to more than 30 countries and is certified on 25 aircraft. The Maverick served during the Vietnam, Yom Kippur, Iran–Iraq, and Persian Gulf Wars, along with other smaller conflicts, destroying enemy forces and installations with varying degrees of success.
Since its introduction into service, numerous Maverick versions had been designed and produced using electro-optical, laser, and imaging infrared guidance systems. The AGM-65 has two types of warhead: one has a contact fuze in the nose, the other has a heavyweight warhead fitted with a delayed-action fuze, which penetrates the target with its kinetic energy before detonating. The missile is currently produced by Raytheon Missile Systems.
The Maverick shares the same configuration as Hughes's AIM-4 Falcon and AIM-54 Phoenix, and measures more than in length and in diameter.
The Maverick's development history began in 1965, when the United States Air Force (USAF) began a program to develop a replacement to the AGM-12 Bullpup. With a range of , the radio-guided Bullpup was introduced in 1959 and was considered a "silver bullet" by operators. However, the launch aircraft was required to fly straight towards the target during the missile's flight instead of performing evasive maneuvers, thus risking the crew. Even when it hit, the small warhead was only useful against small targets like bunkers, when used against larger targets like the Thanh Hóa Bridge it did little other than char the structure. The USAF began a series of projects to replace Bullpup, both larger versions of Bullpup, models C and D, as well as a series of Bullpup adaptations offering fire-and-forget guidance. Among the latter were the AGM-83 Bulldog, AGM-79 Blue Eye and AGM-80 Viper.
From 1966 to 1968, Hughes Missile Systems Division and Rockwell competed for the contract to build an entirely new fire-and-forget missile with far greater range performance than any of the Bullpup versions. Each were allocated $3 million for preliminary design and engineering work of the Maverick in 1966. In 1968, Hughes emerged with the $95 million contract for further development and testing of the missile; at the same time, contract options called for 17,000 missiles to be procured. Hughes conducted a smooth development of the AGM-65 Maverick, with the first unguided test launch from a F-4 on 18 September 1969, with the first guided test on 18 December successfully performing a direct hit on a M41 tank target at the Air Force Missile Development Center at Holloman Air Force Base, New Mexico.
In July 1971, the USAF and Hughes signed a $69.9 million contract for 2,000 missiles, the first of which was delivered in 1972. Although early operational results were favorable, military planners predicted that the Maverick would fare less successfully in the hazy conditions of Central Europe, where it would have been used against Warsaw Pact forces. As such, development of the AGM-65B "Scene Magnified" version began in 1975 before it was delivered during the late 1970s. When production of the AGM-65A/B was ended in 1978, more than 35,000 missiles had been built.
More versions of the Maverick appeared, among which was the laser-guided AGM-65C/E. Development of the AGM-65C started in 1978 by Rockwell, who built a number of development missiles for the USAF. Due to high cost, the version was not procured by the USAF, and instead entered service with the United States Marine Corps (USMC) as the AGM-65E.
Another major development was the AGM-65D, which employed an imaging infrared (IIR) seeker. By imaging on radiated heat, the IIR is all-weather operable as well as showing improved performance in acquiring and tracking the hot engines, such as in tanks and trucks, that were to be one of its major missions. The seekerhead mechanically scanned the scene over a nitrogen-cooled 4-by-4 pixel array using a series of mirrored facets machined into the inner surface of the ring-shaped main gyroscope. The five-year development period of the AGM-65D started in 1977 and ended with the first delivery to the USAF in October 1983. The version received initial operating capability in February 1986.
The AGM-65F is a hybrid Maverick combining the AGM-65D's IIR seeker and warhead and propulsion components of the AGM-65E. Deployed by the United States Navy (USN), the AGM-65F is optimized for maritime strike roles. The first AGM-65F launch from the P-3C took place in 1989, and in 1994, the USN awarded Unisys a contract to integrate the version with the P-3C. Meanwhile, Hughes produced the AGM-65G, which essentially has the same guidance system as the D, with some software modifications that track larger targets.
In the mid-1990s to early 2000s, there were several ideas of enhancing the Maverick's potential. Among them was the stillborn plan to incorporate the Maverick millimeter wave active radar homing, which can determine the exact shape of a target. Another study called "Longhorn Project" was conducted by Hughes, and later Raytheon following the absorption of Hughes into Raytheon, looked a Maverick version equipped with turbojet engines instead of rocket motors. The "Maverick ER", as it was dubbed, would have a "significant increase in range" compared to the Maverick's current range of . The proposal was abandoned, but if the Maverick ER had entered production, it would have replaced the AGM-119B Penguin carried on the MH-60R.
The most modern versions of the Maverick are the AGM-65H/K, which were in production . The AGM-65H was developed by coupling the AGM-65B with a charge-coupled device (CCD) seeker optimized for desert operations and which has three times the range of the original TV-sensor; a parallel USN program aimed at rebuilding AGM-65Fs with newer CCD seekers resulted in the AGM-65J. The AGM-65K, meanwhile, was developed by replacing the AGM-65G's IR guidance system with an electro-optical television guidance system.
The Maverick has a modular design, allowing for different combinations of the guidance package and warhead to be attached to the rocket motor to produce a different weapon. It has long-chord delta wings and a cylindrical body, reminiscent of the AIM-4 Falcon and the AIM-54 Phoenix.
Different models of the AGM-65 have used electro-optical, laser, and imaging infrared guidance systems. The AGM-65 has two types of warhead: one has a contact fuze in the nose, the other has a heavyweight warhead fitted with a delayed-action fuze, which penetrates the target with its kinetic energy before detonating. The latter is most effective against large, hard targets. The propulsion system for both types is a solid-fuel rocket motor behind the warhead.
The Maverick missile is unable to lock onto targets on its own; it has to be given input by the pilot or weapon systems officer (WSO) after which it follows the path to the target autonomously. In an A-10 Thunderbolt II, for example, the video feed from the seeker head is relayed to a screen in the cockpit, where the pilot can check the locked target of the missile before launch. A crosshair on the heads-up display is shifted by the pilot to set the approximate target, where the missile will then automatically recognize and lock on to the target. Once the missile is launched, it requires no further assistance from the launch vehicle and tracks its target automatically. This fire-and-forget property is not shared by the E version that uses semi-active laser homing.
The Maverick was declared operational on 30 August 1972 with the F-4D/Es and A-7s initially cleared for the type; the missile made its combat debut four months later with the USAF in the Vietnam War. During the Yom Kippur War in October 1973, the Israelis used Mavericks to destroy and disable enemy vehicles. Deployment of early versions of the Mavericks in these two wars were successful due to the favorable atmospheric conditions that suited the electro-optical TV seeker. Ninety-nine missiles were fired during the two wars, eighty-four of which were successful.. The Maverick was also used with the first strike drone, the Teledyne Ryan BGM-34. First successful strike mission in 1972.
In June 1975, during a border confrontation, a formation of Iranian F4E Phantoms destroyed a group of Iraqi tanks by firing 12 Mavericks at them. Five years later, during Operation Morvarid as part of the Iran–Iraq War, Iranian F-4s used Mavericks to sink three Osa II missile boats and four P-6 combat ships.
Due to weapons embargoes, Iran had to equip its AH-1J SeaCobra helicopters with AGM-65 Maverick missiles and used them with some success in various operations such as Operation Fatholmobin wherein Iranian AH-1Js fired 11 Mavericks.
In August 1990, Iraq invaded Kuwait. In early 1991, the US-led Coalition executed Operation Desert Storm during which Mavericks played a crucial role in the ousting of Iraqi forces from Kuwait. Employed by F-15E Strike Eagles, F/A-18 Hornets, AV-8B Harriers, F-16 Fighting Falcons and A-10 Thunderbolt IIs, but used mainly by the last two, more than 5,000 Mavericks were used to attack armored targets. The most-used variant by the USAF was the IIR-guided AGM-65D. The reported hit rate by USAF Mavericks was 80–90%, while for the USMC it was 60%. The Maverick was used again in Iraq during the 2003 Iraq War, during which 918 were fired.
The first time the Maverick were fired from a Lockheed P-3 Orion at a hostile vessel was when the USN and coalition units came to the aid of Libyan rebels to engage the Libyan Coast Guard vessel "Vittoria" in the port of Misrata, Libya, during the late evening of 28 March 2011. "Vittoria" was engaged and fired upon by a USN P-3C Maritime Patrol aircraft with AGM-65 Maverick missiles..Mavericks and UAV's: In the late 1960s, the Navy studied the possibility to convert the BQM-34A "Firebee" target drone to a remote-controlled anti-ship missile. In several test flights, BQM-34As equipped with a TV system in the nose, were successfully flown by remote "pilots" watching the TV image. Precision low-level flight above the sea was made possible by the Ryan-developed RALACS (Radar Altimeter Low Altitude Control System). In September 1971, successful tests of Model 248 missiles (called "BQM/SSM") against ship targets showed the validity of the basic concept, but the project was terminated due to lack of funding.
In the same year, the USAF showed interest in a development of the "Firebee I" to be used for enemy air-defense suppression, because of the high loss rate in these missions. In March 1971, Teledyne Ryan received a contract to convert four Model 147S drones to BGM-34A (Model 234) configuration. Like the Navy's BQM/SSM, the BGM-34A was piloted by an operator watching a TV image transmitted from the drone's nose. In tests during 1971/72, the BGM-34As successfully launched AGM-65 "Maverick" air-to-surface missiles and electro-optically guided glide bombs against simulated SAM sites. Interestingly, almost 30 years later a firing of an AGM-114 "Hellfire" missile by an MQ-1L "Predator" UAV was much hyped as a breakthrough in armed UAV technology.
LAU-117 Maverick launchers have been used on US Army, USN, USAF, and USMC aircraft:
The Maverick has been exported to at least 35 countries:
According to the article on Kh-23 Grom the guidance system of the Serbian Grom-B is based on the Maverick system. | https://en.wikipedia.org/wiki?curid=3151 |
AIM-54 Phoenix
The AIM-54 Phoenix is a radar-guided, long-range air-to-air missile (AAM), carried in clusters of up to six missiles on the Grumman F-14 Tomcat, its only operational launch platform. The Phoenix was the United States' only long-range air-to-air missile. The combination of Phoenix missile and the AN/AWG-9 guidance radar was the first aerial weapons system that could simultaneously engage multiple targets. Due to its active radar tracking, the brevity code "Fox Three" was used when firing the AIM-54.
Both the missile and the aircraft were used by Iran and the United States Navy. In US service both are now retired, the AIM-54 Phoenix in 2004 and the F-14 in 2006. They were replaced by the shorter-range AIM-120 AMRAAM, employed on the F/A-18 Hornet and F/A-18E/F Super Hornet—in its AIM-120D version, the latest version of the AMRAAM just matches the Phoenix's maximum range.
The AIM-54 is credited with 62 air-to-air kills, all scored by Iran during the long Iran–Iraq War. Following the retirement of the F-14 by the U.S. Navy, the weapon's only current operator is the Islamic Republic of Iran Air Force.
Since 1951, the Navy faced the initial threat from the Tupolev Tu-4K 'Bull' carrying anti-ship missiles or nuclear bombs.
Eventually, during the height of the Cold War, the threat would have expanded into regimental-size raids of Tu-16 Badger and Tu-22M Backfire bombers equipped with low-flying, long-range, high-speed, nuclear-armed cruise missiles and considerable electronic countermeasures (ECM) of various types. This combination was considered capable of saturating fleet defenses and threatening carrier groups.
The Navy would require a long-range, long-endurance interceptor aircraft to defend carrier battle groups against this threat. The proposed F6D Missileer was intended to fulfill this mission and oppose the attack as far as possible from the fleet it was defending. The weapon needed for interceptor aircraft, the Bendix AAM-N-10 Eagle, was to be an air-to-air missile of unprecedented range when compared to contemporary AIM-7 Sparrow missiles. It would work together with Westinghouse AN/APQ-81 radar. The Missileer project was cancelled in December 1960.
In the early 1960s, the U.S. Navy made the next interceptor attempt with the F-111B, and they needed a new missile design. At the same time, the USAF canceled the projects for their land-based high-speed interceptor aircraft, the North American XF-108 Rapier and the Lockheed YF-12, and left the capable AIM-47 Falcon missile at a quite advanced stage of development, but with no effective launch platform.
The AIM-54 Phoenix, developed for the F-111B fleet air defense fighter, had an airframe with four cruciform fins that was a scaled-up version of the AIM-47. One characteristic of the Missileer ancestry was that the radar sent it mid-course corrections, which allowed the fire control system to "loft" the missile up over the target into thinner air where it had better range.
The F-111B was canceled in 1968. Its weapons system, the AIM-54 working with the AWG-9 radar, migrated to the new U.S. Navy fighter project, the VFX, which would later become the F-14 Tomcat.
In 1977, development of a significantly improved Phoenix version, the AIM-54C, was developed to better counter projected threats from tactical anti-naval aircraft and cruise missiles, and its final upgrade included a re-programmable memory capability to keep pace with emerging ECM.
The AIM-54/AWG-9 combination had multiple track capability (up to 24 targets) and launch (up to six Phoenixes can be launched nearly simultaneously); the large missile is equipped with a conventional warhead.
On the F-14, four missiles can be carried under the fuselage tunnel attached to special aerodynamic pallets, plus two under glove stations. A full load of six Phoenix missiles and the unique launch rails weighs in at over , about twice the weight of Sparrows, putting it above the allowable bringback load (which also would include enough fuel for go-around attempts). As such, carrying six Phoenix missiles would necessitate the jettison of at least some of the Phoenix missiles if they were not used. The most common air superiority payload is a mix of two Phoenix, four Sparrow, and two Sidewinder missiles.
Most other US aircraft relied on the smaller, semi-active medium-range AIM-7 Sparrow. Semi-active guidance meant the aircraft no longer had a search capability while supporting the launched Sparrow, reducing situational awareness.
The Tomcat's radar could track up to 24 targets in track-while-scan mode, with the AWG-9 selecting up to six potential targets for the missiles. The pilot or radar intercept officer (RIO) could then launch the Phoenix missiles once parameters were met. The large tactical information display (TID) in the RIO's cockpit gave information to the aircrew (the pilot had the ability to monitor the RIO's display) and the radar could continually search and track multiple targets after Phoenix missiles were launched, thereby maintaining situational awareness of the battlespace.
The Link 4 datalink allowed US Navy Tomcats to share information with the E-2C Hawkeye AEW aircraft. During Desert Shield in 1990, the Link 4A was introduced; this allowed the Tomcats to have a fighter-to-fighter datalink capability, further enhancing overall situational awareness. The F-14D entered service with the JTIDS that brought the even better Link 16 datalink "picture" to the cockpit.
The Phoenix has several guidance modes and achieves its longest range by using mid-course updates from the F-14A/B AWG-9 radar (APG-71 radar in the F-14D) as it climbs to cruise between and at close to Mach 5. The Phoenix uses this high altitude to maximize its range by reducing atmospheric drag. At around from the target, the missile activates its own radar to provide terminal guidance. Minimum engagement range for the Phoenix is around ; at this range active homing would initiate upon launch.
The AIM-54 Phoenix was retired from USN service on September 30, 2004. F-14 Tomcats were retired on September 22, 2006. They were replaced by shorter-range AIM-120 AMRAAMs, employed on the F/A-18E/F Super Hornet.
Despite the much-vaunted capabilities, the Phoenix was rarely used in combat, with only two confirmed launches and no confirmed targets destroyed in US Navy service. The USAF F-15 Eagle had responsibility for overland combat air patrol duties in Operation Desert Storm in 1991, primarily because of the onboard F-15 IFF capabilities. The Tomcat did not have the requisite IFF capability mandated by the JFACC to satisfy the rules of engagement to utilize the Phoenix capability at beyond visual range. The AIM-54 was not adopted by any foreign nation besides Iran, or any other US armed service, and was not used on any aircraft other than the F-14.
On January 7, 1974 as part of Project "Persian King", the Imperial Iranian Air Force placed an order for 424 AIM-54As, later increasing it by 290 missiles that June. Of the initial order, 274 missiles and 10 training rounds were delivered for US$150 million, until the 1979 Revolution ended deliveries and left the remaining 150 missiles embargoed and the additional order of 290 cancelled.
According to Tom Cooper and Farzad Bishop, during the Iran-Iraq War AIM-54s fired by IRIAF Tomcats achieved 78 victories against Iraqi MiG-21/23/25s, Tu-22s, Su-20/22s, Mirage F 1s, Super Étendards, and even two AM-39 Exocets and a C-601. This includes two occasions where one AIM-54 was responsible for the downing of two Iraqi aircraft, as well as an incident on January 7, 1981 where a Phoenix fired at a four-ship of MiG-23s downed three and damaged the fourth.
The US refused to supply spare parts and maintenance after the 1979 Revolution, except for a brief period during the Iran-Contra Affair. According to Cooper, the Islamic Republic of Iran Air Force kept its F-14 fighters and AIM-54 missiles in regular use during the entire Iran–Iraq War, though periodic lack of spares grounded large parts of the fleet at times. During late 1987, the stock of AIM-54 missiles was at its lowest, with fewer than 50 operational missiles available. The missiles needed fresh thermal batteries that could only be purchased from the US. Iran found a clandestine buyer that supplied it with batteries, which cost up to US$10,000 each. Iran received spares and parts for both the F-14s and AIM-54s from various sources during the Iran–Iraq War, and has received more spares after the conflict. Iran started a program to build spares for the planes and missiles, and although there are claims that it no longer relies on outside sources to keep its F-14s and AIM-54s operational, there is evidence that Iran continues to procure parts clandestinely.
Both the F-14 Tomcat and AIM-54 Phoenix missile continue in the service of the Islamic Republic of Iran Air Force. Iran claimed to be working on building an equivalent missile and in 2013 unveiled the Fakour-90, an upgraded and reverse-engineered version of the Phoenix.
There were also test, evaluation, ground training, and captive air training versions of the missile; designated ATM-54, AEM-54, DATM-54A, and CATM-54. The flight versions had A and C versions. The DATM-54 was not made in a C version as there was no change in the ground handling characteristics.
The following is a list of AIM-54 Phoenix specifications: | https://en.wikipedia.org/wiki?curid=3152 |
Lockheed AC-130
The Lockheed AC-130 gunship is a heavily armed, long-endurance, ground-attack variant of the C-130 Hercules transport, fixed-wing aircraft. It carries a wide array of ground attack weapons that are integrated with sophisticated sensors, navigation, and fire-control systems. Unlike other modern military fixed-wing aircraft, the AC-130 relies on visual targeting. Because its large profile and low operating altitudes of approximately 7,000 feet (2,100 m) make it an easy target, its close air support missions are usually flown at night.
The airframe is manufactured by Lockheed Martin, while Boeing is responsible for the conversion into a gunship and for aircraft support. Developed during the Vietnam War as "Project Gunship II", the AC-130 replaced the Douglas AC-47 Spooky, or "Gunship I". The sole operator is the United States Air Force, which uses the AC-130U Spooky and AC-130W Stinger II variants for close air support, air interdiction, and force protection, with the upgraded AC-130J Ghostrider entering service. Close-air-support roles include supporting ground troops, escorting convoys, and urban operations. Air-interdiction missions are conducted against planned targets and targets of opportunity. Force-protection missions include defending air bases and other facilities. AC-130Us are based at Hurlburt Field, Florida, while AC-130Ws are based at Cannon AFB, New Mexico; gunships can be deployed worldwide. The squadrons are part of the Air Force Special Operations Command (AFSOC), a component of the United States Special Operations Command (SOCOM).
The AC-130 has an unpressurized cabin, with the weaponry mounted to fire from the port side of the fuselage. During an attack, the gunship performs a pylon turn, flying in a large circle around the target, therefore being able to fire at it for far longer than in a conventional strafing attack. The AC-130H Spectre was armed with two M61 Vulcan cannons, one L60 Bofors 40 mm cannon, and one M102 howitzer; after 1994, the cannons were removed. The upgraded AC-130U Spooky has a single GAU-12 Equalizer cannon in place of the Spectre's two cannons, an improved fire-control system, and increased ammunition capacity. The new AC-130J was based on the MC-130J Commando II special-operations tanker. The AC-130W Stinger II is a modified C-130H with upgrades including a precision strike package.
During the Vietnam War, the C-130 Hercules was selected to replace the Douglas AC-47 Spooky gunship (Project Gunship I) to improve mission endurance and increase capacity to carry munitions. Capable of flying faster than helicopters and at high altitudes with excellent loiter time, the use of the pylon turn allowed the AC-47 to deliver continuous, accurate fire to a single point on the ground.
In 1967, JC-130A 54-1626 was selected for conversion into the prototype AC-130A gunship (Project Gunship II). The modifications were done at Wright-Patterson Air Force Base by the Aeronautical Systems Division. A direct-view night-vision telescope was installed in the forward door, an early forward-looking infrared device was placed in the forward part of the left wheel well, with miniguns and rotary cannons fixed facing down and aft along the left side. The analog fire-control computer prototype was handcrafted by RAF Wing Commander Tom Pinkerton at the USAF Avionics Laboratory at Wright-Patterson AFB. Flight testing of the prototype was performed primarily at Eglin Air Force Base, followed by further testing and modifications. By September 1967, the aircraft was certified ready for combat testing and was flown to Nha Trang Air Base, South Vietnam for a 90-day test program. The AC-130 was later supplemented by the AC-119 Shadow (Project Gunship III), which later proved to be underpowered.
Seven more warplanes were converted to the "Plain Jane" configuration like the AC-130 prototype in 1968, and one aircraft received the "Surprise Package" refit in 1969. The Surprise Package upgrade included the latest 20 mm rotary autocannons and 40 mm Bofors cannon, but no 7.62 mm close-support armament. The Surprise Package configuration served as a test bed for the avionic systems and armament for the AC-130E. In 1970, 10 more AC-130As were acquired under the "Pave Pronto" project. In the summer of 1971, Surprise Package AC-130s were converted to the Pave Pronto configuration and assumed the new nickname of "Thor". Conversion of C-130Es into AC-130Es for the "PAVE Spectre" project followed. Regardless of their project names, the aircraft were more commonly referred to by the squadron's call sign, Spectre.
In 2007, AFSOC initiated a program to upgrade the armament of AC-130s. The test program planned for the 25 mm GAU-12/U and 40 mm Bofors cannon on the AC-130U gunships to be replaced with two 30 mm Mk 44 Bushmaster II cannons. In 2007, the Air Force modified four AC-130U gunships as test platforms for the Bushmasters. These were referred to as AC-130U Plus 4 or AC-130U+4. AFSOC, however, canceled its plans to install the new cannons on its fleet of AC-130Us. It has since removed the guns and reinstalled the original 40 mm and 25 mm cannons and returned the planes to combat duty. Brigadier General Bradley A. Heithold, AFSOC's director of plans, programs, requirements, and assessments, said on 11 August 2008 that the effort was canceled because of problems with the Bushmaster's accuracy in tests "at the altitude we were employing it". Also, schedule considerations drove the decision, he said.
Plans were made to possibly replace the 105 mm cannon with a breech-loading 120 mm M120 mortar, and to give the AC-130 a standoff capability using either the AGM-114 Hellfire missile, the Advanced Precision Kill Weapon System (based on the Hydra 70 rocket), or the Viper Strike glide bomb.
In 2010, the Air Force awarded L-3 Communications a $61 million contract to add precision strike packages to eight MC-130W Combat Spear special-mission aircraft to give them a gunship-like attack capability; such-equipped MC-130Ws are known as Dragon Spears. AFSOC is arming these aircraft to relieve the high operational demands on AC-130 gunships until new AC-130Js enter service. The MC-130W Dragon Spear was renamed AC-130W Stinger II in 2011. The precision strike packages consist of a 30 mm gun and several precision guided munitions. Rails are mounted on the outboard pylon of the wing for four Hellfire missiles, SDBs, or SDB IIs under each. Ten Common Launch Tubes (CLTs) are mounted on the rear ramp to fire Griffin A missiles; additional missiles are stored in the aircraft that can be reloaded in flight. CLTs are able to fire other small munitions able to fit inside the -diameter, -long tubes.
The Air Force launched an initiative in 2011 to acquire 16 new gunships based on newly built MC-130J Combat Shadow II special-operations tankers outfitted with a "precision strike package" to give them an attack capability, requesting $1.6 billion from fiscal years 2011 through 2015. This would increase the size of the gunship fleet to 33 aircraft, a net increase of eight after the planned retirement of eight aging AC-130Hs. The first aircraft would be bought in fiscal 2012, followed by two in fiscal 2013, five in fiscal 2014, and the final eight in fiscal 2015. The decision to retain the C-130 came after funding for 16 C-27Js was removed from the fiscal 2010 budget.
The AC-130J will follow the path of the Dragon Spear program. On 9 January 2013, the Air Force began converting the first MC-130J Combat Shadow II into an AC-130J Ghostrider. The first AC-130J Ghostrider was delivered to AFSOC on 29 July 2015. The first AC-130J gunships achieved initial operational capability (IOC) on 30 September 2017. The AC-130J has two planned increments: the Block 10 configuration includes an internal 30 mm gun, small diameter bombs, and laser-guided missiles launched from the rear cargo door; and Block 20 configuration adds a 105 mm cannon, large aircraft infrared countermeasures, wing-mounted Hellfire missiles, and radio-frequency countermeasures.
The Air Force decided to add a 105 mm cannon to the AC-130J in addition to the 30 mm cannon and smart bombs, the shells being more accurate and cheaper than dropping SDBs. AFSOC is actively pursuing a directed-energy weapon onboard the AC-130J in place of the 30mm gun by 2022, similar to the previous Advanced Tactical Laser program. It is to produce a beam of up to 120 kW, or potentially even 180–200 kW, weigh about , defensively destroy antiaircraft missiles, and offensively engage communications towers, boats, cars, and aircraft. However, laser armament may only be installed on a few aircraft rather than the entire AC-130J fleet; the laser will be mounted on the side in place of the 30 mm cannon. Other potential additions include an active denial system to perform airborne crowd control, and small unmanned aerial vehicles from the common launch tubes to provide remote video feed and coordinates to weapons operators through cloud cover. Called the Tactical Off-board Sensor (TOBS), the drones would be expendable and fly along a programmed orbit to verify targets the aircraft cannot see itself because of bad weather or standing off from air defenses. AFSOC will initially use the Raytheon Coyote small UAV for the TOBS mission, as it is an off-the-shelf design with a one-hour endurance, but plans to fulfill the role with a new drone capable of a four-hour endurance by 2019.
The Air Force was also interested in acquiring a glide bomb that can be launched from the common launch tubes capable of hitting ground vehicles traveling as fast as 120 km/h (70 mph) while above . In June 2016, Dynetics was awarded a contract by SOCOM to integrate its tactical munition onto the AC-130. Designated the GBU-69/B Small Glide Munition, the weapon weighs and is armed with a blast-fragmentation warhead that can detonate by direct impact or at a selected height; despite being smaller, being unpowered allows for its warhead to be heavier than those on the Hellfire and Griffin A missiles, and , respectively. Guidance is provided by a GPS receiver with antispoofing software and four Distributed Aperture Semiactive Laser Seeker apertures adapted from the WGU-59/B APKWS for terminal guidance. Approval for fielding occurred in early 2017. Dynetics was awarded a contract to deliver an initial batch of 70 SGMs in June 2017, with plans to buy up to 1,000. The SGM can travel .
, AC-130 gunships have been providing close air support for special operators for 50 years. Although the aircraft have been kept relevant through constant upgrades to their weaponry, sensor packages, and countermeasures, they are not expected to be survivable in future nonpermissive environments due to their high signatures and low airspeeds. Military analysts, such as the Center for Strategic and Budgetary Assessments, have suggested that AFSOC invest in more advanced technologies to fill the role to operate in future contested combat zones, including a mix of low-cost disposable unmanned and stealthy strike aircraft.
The AC-130 is a heavily armed, long-endurance aircraft carrying an array of antiground-oriented weapons that are integrated with sophisticated sensors, navigation, and fire-control systems. It is capable of delivering precision firepower or area-saturation fire over a target area over a long period of time, at night, or in adverse weather. The sensor suite consists of a television sensor, infrared sensor, and radar. These sensors allow the gunship to visually or electronically identify friendly ground forces and targets in most weather conditions.
The AC-130U is equipped with the AN/APQ-180, a synthetic aperture radar, for long-range target detection and identification. The gunship's navigational devices include inertial navigation systems and a global positioning system. The AC-130U employs technologies developed in the 1990s, which allow it to attack two targets simultaneously. It has twice the munitions capacity of the AC-130H. Although the AC-130U conducts some operations in daylight, most of its combat missions are conducted at night. The AC-130H's unit cost is US$132.4 million, and the AC-130U's cost is $190 million (fiscal 2001 dollars).
During the Vietnam War era, the various AC-130 versions following the Pave Pronto modifications were equipped with a magnetic anomaly detector system called Black Crow (designated AN/ASD-5), a highly sensitive passive device with a phased-array antenna located in the left-front nose radome that could pick up localized deviations in the Earth's magnetic field normally used to detect submerged submarines. The Black Crow system was slaved into the targeting computers of the AC-130A/E/H, enabling the detection of the unshielded ignition coils of North Vietnamese trucks hidden under dense jungle foliage along the Ho Chi Minh Trail. It could also detect hand-held transmitter signals of air controllers on the ground to identify and locate targets.
The PGM-38/U enhanced 25 mm high-explosive incendiary round was created to expand the AC-130U gunships' mission in standoff range and survivability for its 25 mm GAU-12/U gun. This round is a combination of the existing PGU-25 HEI and a M758 fuze designated as FMU-151/B to meet the MIL-STD-1316. The FMU-151 has an improved arming delay with multisensitive range.
The AC-130 gunship first arrived in South Vietnam on 21 September 1967 under the Gunship II program and began combat operations over Laos and South Vietnam that year. In June 1968, AC-130s were deployed to Tan Son Nhut AB near Saigon for support against the Tet Offensive. By 30 October 1968, enough AC-130 Gunship IIs arrived to form a squadron, the 16th Special Operations Squadron of the 8th Tactical Fighter Wing, at Ubon Royal Thai Air Force Base, Thailand. At this time, the C-130A gunship was designated the AC-130A.
On 18 August 1968, an AC-130 gunship flying an armed reconnaissance mission in Vietnam's III Corps was diverted to support the Katum Special Forces Camp. The ground commander quickly assessed the accurate fire and capabilities of this weapons system and called for fire on his own perimeter when the Viet Cong attempted to bridge the wire on the west side of his position.
By December 1968, most AC-130s flew under F-4 Phantom II escort (to protect the gunship against heavy and concentrated antiaircraft fire) from the 497th Tactical Fighter Squadron, normally three Phantoms per gunship. On 24 May 1969, the first Spectre gunship was lost to enemy fire.
In late 1969, under code name "Surprise Package", 56-0490 arrived with solid-state, laser-illuminated, low light-level TV with a companion YAG laser designator, an improved forward-looking infrared (FLIR) sensor, video recording for TV and FLIR, an inertial navigation system, and a prototype digital fire-control computer. The remaining AC-130s were refitted with upgraded similar equipment in the summer of 1970, and then redeployed to Ubon RTAFB. On 25 October 1971, the first "Cadillac" gunship, the AC-130E, arrived in Vietnam. On 17 February 1972, the first 105 mm cannon arrived for service with Spectre and was installed on Gunship 570. It was used from mid-February until the aircraft received battle damage to its right flap. The cannon was switched to Gunship 571 and was used until 30 March when the aircraft was shot down.
On 28 January 1973, the Vietnam peace accord went into effect, marking the end of Spectre operations in Vietnam. Spectre was still needed and active in the region, supporting operations in Laos and Cambodia. On 22 February 1973, American offensive operations in Laos ended and the gunships became totally committed to operations in the Cambodian conflict.
On 12 April 1975, the Khmer Rouge was threatening the capital of Phnom Penh and AC-130s were called on to help in Operation Eagle Pull, the final evacuation of American and allied officials from Phnom Penh before it was conquered by the communists. The AC-130 was also over Saigon on 30 April 1975 to protect the final evacuation in Operation Frequent Wind. Spectres were also called in when the USS "Mayaguez" was seized, on the open sea, by Khmer Rouge soldiers and sailors on 15 May 1975.
Six AC-130s and 52 air crew members were lost during the war. AC-130s destroyed more than 10,000 trucks and participated in many crucial close-air-support missions in Vietnam.
With the conclusion of hostilities in Southeast Asia in the mid-1970s, the AC-130H became the sole gunship in the regular Air Force, home based at Hurlburt Field, Florida, while the AC-130A fleet was transferred to the Air Force Reserve's 919th Tactical Airlift Group (919 TAG) at Eglin AFB Auxiliary Field #3/Duke Field, Florida. With the transition to the AC-130A, the 919 TAG was then redesignated as the 919th Special Operations Group.
In the late 1970s, when the AC-130H fleet was first being modified for in-flight refueling capability, a demonstration mission was planned and flown from Hurlburt Field, Florida, nonstop, to conduct a 2-hour live-fire mission over Empire Firing Range in the Republic of Panama, then return home. This 13-hour mission with two in-flight refuelings from KC-135 tankers proved the validity of flying long-range missions outside the contiguous United States to attack targets then return to home base without intermediate stops.
AC-130s from both the 4th and 16th Special Operations Squadrons have been deployed in nearly every conflict in which the United States has been involved, officially and unofficially, since the end of the Vietnam War.
In July 1979, AC-130H crews deployed to Howard Air Force Base, Panama, as a precaution against possible hostile actions against American personnel during the Nicaraguan Revolution. New time aloft and nonstop distance records were subsequently set by a 16th SOS two-ship AC-130H formation flight that departed Hurlburt Field on 13 November 1979 and landed on 15 November at Andersen Air Force Base, Guam, a distance of and 29 hours 43 minutes nonstop, refueling four times in-flight. Refueling support for the Guam deployment was provided by KC-135 crews from the 305th Air Refueling Wing from Grissom AFB, Indiana.
In November 1979, four AC-130H gunships flew nonstop from Hurlburt Field to Anderson AFB, Guam, because of the hostage situation at the US Embassy in Iran. At Guam, AC-130H crews developed communications-out/lights-out refueling procedures for later employment by trial-and-error. This deployment with the 1 SOW/CC as task force commander was directed from the office of the CJCS for fear that Iranian militants could begin executing American Embassy personnel who had been taken hostage on 4 November. One early option considered AC-130H retaliatory punitive strikes deep within Iran. Later gunship flights exceeded the 1979 Hurlburt-to-Guam flight. Upon return in March 1980, the four planes soon found themselves in Egypt to support the ill-fated hostage rescue attempt.
During Operation Urgent Fury in Grenada in 1983, AC-130s suppressed enemy air-defense systems and attacked ground forces enabling the assault of the Point Salines Airfield via airdrop and air-land of friendly forces. The AC-130 aircrew earned the Lieutenant General William H. Tunner Award for the mission.
The AC-130Hs of the 16th Special Operations Squadron unit maintained an ongoing rotation to Howard AB, Panama, monitoring activities in El Salvador and other Central American points of interest, with rules of engagement eventually permitting attacks on FMLN targets. This commitment of maintainers and crews started in 1983 and lasted until 1990. The AC-130 is considered to have hastened the end of the Salvadoran Civil War in the 1980s. Crews flew undercover missions from Honduras and attacked guerrilla camps and concentrations.
AC-130s also had a primary role during the United States invasion of Panama (named Operation Just Cause) in 1989, when they destroyed Panama Defense Force headquarters and numerous command-and-control facilities, and provided close air support for US ground troops. Aircrews earned the Mackay Trophy for the most meritorious flight of the year, and the Tunner Award.
During the Gulf War of 1990–91 (Operations Desert Shield and Desert Storm), Regular Air Force and Air Force Reserve AC-130s provided close air support and force protection (air base defense) for ground forces, and battlefield interdiction. The primary interdiction targets were early-warning/ground-control intercept sites along the southern border of Iraq. At its standard altitude of 12,000 feet, the aircraft had a proven ability to engage moving ground targets. The first gunship to enter the Battle of Khafji helped stop a southbound Iraqi armored column on 29 January 1991. One day later, three more gunships provided further aid to Marines participating in the operation. The gunships attacked Iraqi positions and columns moving south to reinforce their positions north of the city.
Despite the threat of SAMs and increasing visibility during the early morning hours of 31 January 1991, one AC-130H, AF Serial No. 69-6567, call-sign Spirit 03, opted to stay to continue to protect the Marines. A lone Iraqi with a Strela-2 MANPADS shot Spirit 03 down, and all 14 crew members were killed.
The military has used AC-130 gunships during the humanitarian operations in Somalia (Operation Restore Hope and Operation United Shield) in 1992–93 and Operation Uphold Democracy in Haiti in 1994. AC-130s took part in Operation Assured Response in Liberia in 1996 and in Operation Silver Wake in 1997, the evacuation of American non-combatants from Albania.
AC-130s took part in the NATO missions in Bosnia and Herzegovina and Kosovo during the 1990s.
The AC-130U gunship set a new record for the longest sustained flight by any C-130 on 22 and 23 October 1997, when two AC-130U gunships flew 36 hours nonstop from Hurlburt Field to Taegu Air Base (Daegu), South Korea, being refueled seven times in the air by KC-135 tankers. The two gunships took on 410,000 lb (186,000 kg) of fuel. Gunships also were part of the buildup of US forces in 1998 to compel Iraq to allow UNSCOM weapons inspections.
The US has used gunships with deployments to the war in Afghanistan (Operation Enduring Freedom – Afghanistan) (2001–2014), and Iraq War (Operation Iraqi Freedom) (2003–11). AC-130 strikes were directed by special forces on known Taliban locations during the early days of the war in Afghanistan. US Special Operations Forces are using the AC-130 to support its operations. The day after arriving in Afghanistan, the AC-130s attacked Taliban and Al-Qaeda forces near the city of Konduz and were directly responsible for the city's surrender the next day. On 26 November 2001, Spectres were called in to put down a rebellion at the prison fort of Qala-I-Janghi. The 16 SOS flew missions over Mazar-i-Sharif, Kunduz, Kandahar, Shkin, Asadabad, Bagram, Baghran, Tora Bora, and virtually every other part of Afghanistan. The Spectre participated in countless operations within Afghanistan, performing on-call close air support and armed reconnaissance. In March 2002, three AC-130 Spectres provided 39 crucial combat missions in support of Operation Anaconda in Afghanistan. During the intense fighting, the planes fired more than 1,300 40 mm and 1,200 105 mm rounds.
Close air support was the main mission of the AC-130 in Iraq. Night after night, at least one AC-130 was in the air to fulfill one or more air-support requests (ASRs). A typical mission had the AC–130 supporting a single brigade's ASRs followed by aerial refueling and another two hours with another brigade or SOF team. The use of AC-130s in places like Fallujah, urban settings where insurgents were among crowded populations of non-combatants, was criticized by human rights groups. AC-130s were also used for intelligence gathering with their sophisticated long-range video, infrared and radar sensors. In 2007, US Special Operations forces also used the AC-130 in attacks on suspected Al-Qaeda militants in Somalia.
Eight AC-130H and 17 AC-130U aircraft were in active-duty service as of July 2010. In March 2011, the Air Force deployed two AC-130U gunships to take part in Operation Odyssey Dawn, the US military intervention in Libya, which eventually came under NATO as Operation Unified Protector.
By September 2013, 14 MC-130W Dragon Spear aircraft have been converted to AC-130W Stinger II gunships. The Stinger gunships have been deployed to Afghanistan to replace the aging AC-130H aircraft and provide an example for the new AC-130J Ghostrider. Modifications began by cutting holes in the plane to make room for weapons and adding kits and bomb bases for laser-guided munitions. Crews added a 105 mm cannon, 20-inch infrared and electro-optical sensors, and the ability to carry 250-lb bombs on the wings.
The final AC-130H Spectre gunship, tail number 69-6569 "Excalibur" was retired on 26 May 2015 at Cannon Air Force Base, New Mexico.
On 15 November 2015, two days after the attacks in Paris by ISIL, AC-130s and A-10 Thunderbolt II attack aircraft destroyed a convoy of over 100 ISIL-operated oil tanker trucks in Syria. The attacks were part of an intensification of the US-led Military intervention against ISIL called Operation Tidal Wave II (named after the original Operation Tidal Wave during World War II, a failed attempt to raid German oil fields that resulted in heavy aircraft and aircrew loss) in an attempt to cut off oil smuggling as a source of funding for the group.
On 3 October 2015, an AC-130 mistakenly attacked the Doctors Without Borders hospital in Kunduz, Afghanistan. In five separate runs, the gunship struck the hospital that was erroneously identified as the source of attacks on coalition members. Subsequent inquiries led to punishment of 16 military personnel and cited "human error" as the root cause.
On 30 September 2017, the Air Force declared the AC-130J Ghostrider had achieved initial operational capability, with six gunships having been delivered; the aircraft is planned to reach full operational capability by 2023 with 37 gunships delivered. The J-variant is lighter and more fuel efficient than previous versions, able to fly at with a range of and service ceiling of . The AC-130U returned from its final combat deployment on 8 July 2019; the final AC-130U was retired in August 2019. AFSOC started taking delivery of the AC-130J in spring 2019, and the aircraft began deploying to Afghanistan by the summer.
AC-130W Stinger II (formerly MC-130W Dragon Spear)
AC-130J Ghostrider
AC-130A Spectre (Project Gunship II, Surprise Package, Pave Pronto)
AC-130E Spectre (Pave Spectre, Pave Aegis)
AC-130H Spectre
AC-130U Spooky
One of the first seven AC-130A aircraft deployed to Vietnam was AF serial no. 53–3129, named "First Lady" in November 1970. This aircraft was a conversion of the first production C-130. On 25 March 1971, it took an anti-aircraft artillery hit in the belly just aft of the nose gear wheel well over the Ho Chi Minh trail in Laos. The 37 mm shell destroyed everything below the crew deck and barely missed striking two crew members. The pilot was able to crash land the aircraft safely. In 1975, after the conclusion of US involvement in the Vietnam war, it was transferred to the Air Force Reserve, where it served with the 711th Special Operations Squadron of the 919th Special Operations Wing. In 1980, the aircraft was upgraded from the original three-bladed propellers to the quieter four-bladed propellers and was eventually retired in late 1995. The retirement also marked an end to the Air Force Reserve Command flying the AC-130A. The aircraft now sits on display in the final Air Force Reserve Command configuration with grey paint, black markings, and the four-bladed Hamilton Sunstrand 54H60-91 props at the Air Force Armament Museum at Eglin Air Force Base, Florida, USA.
A second aircraft, AF serial no. 56–0509, named the "Ultimate End", was originally accepted as a C-130A by the Air Force on 28 February 1957, and modified to the AC-130A configuration on 27 July 1970. The aircraft participated in the Vietnam War and the rescue of the SS Mayaguez. "Ultimate End" demonstrated the durability of the C-130 after surviving hits in five places by 37 mm anti-aircraft artillery on 12 December 1970, extensive left wing leading edge damage on 12 April 1971 and a 57 mm round damaging the belly and injuring one crewman on 4 March 1972. "Ultimate End" was reassigned to the Air Force Reserve's 919th Special Operations Wing at Eglin AFB Auxiliary Field No.3 / Duke Field on 17 June 1975, where it continued in service until retired in the fall 1994 and transferred to Air Force Special Operations Command's "Heritage Air Park" at Hurlburt Field, Florida. While assigned to the 711th Special Operations Squadron, "Ultimate End" served in Operations JUST CAUSE in Panama, DESERT STORM in Kuwait and Iraq, and UPHOLD DEMOCRACY in Haiti. After 36 years and seven months of service, 24 years as a gunship, "Ultimate End" retired from active service on 1 October 1994. It made its last flight from Duke Field to Hurlburt Field on 20 October 1994. The Spectre Association dedicated "Ultimate End" (which served with the 16 SOS in Vietnam) on 4 May 1995. Lt Col Michael Byers, then 16 SOS commander, represented the active-duty gunship force and Clyde Gowdy of the Spectre Association represented all Spectre personnel past and present for the unveiling of a monument at the aircraft and the dedication as a whole.
A third AC-130A, AF serial no. 54–1630, is on display in the Cold War Gallery at the National Museum of the United States Air Force at Wright-Patterson AFB, Ohio. Named "Azrael" for the angel of death in Islam who severs the soul from the body, this aircraft figured prominently in the closing hours of Operation Desert Storm. On 26 February 1991, Coalition ground forces were driving the Iraqi Army out of Kuwait. With an Air Force Reserve crew called to active duty, Azrael was sent to the Al Jahra highway (Highway 80) between Kuwait City and Basra, Iraq, to intercept the convoys of tanks, trucks, buses, and cars fleeing the battle. Facing SA-6 and SA-8 surface-to-air missiles and 37 mm and 57 mm radar-guided anti-aircraft artillery the crew attacked and destroyed or disabled most of the convoys. "Azrael" was also assigned to the 919th Special Operations Wing and retired to the museum in October 1995.
Another AC-130A, AF serial no. 54–1626, the original prototype AC-130 named "Gunship II" is on display at the outdoor Air Park at the National Museum of the United States Air Force at Wright-Patterson AFB, Ohio. This aircraft served in Southeast Asia from 1967 to 1972, then served in JC-130A test configuration. It was transferred to the National Museum of the United States Air Force in 1976, and converted back to AC-130A configuration in the late 1990s.
AC-130A serial no. 54–1623, c/n 3010, named "Ghost Rider" served in Southeast Asia and later conflicts until being retired in 1997 to Dobbins AFB, Georgia. Ghost Rider eventually was transferred and displayed at the Aviation Wing Museum at Marietta, Georgia. | https://en.wikipedia.org/wiki?curid=3155 |
Alternative algebra
In abstract algebra, an alternative algebra is an algebra in which multiplication need not be associative, only alternative. That is, one must have
for all "x" and "y" in the algebra.
Every associative algebra is obviously alternative, but so too are some strictly non-associative algebras such as the octonions.
Alternative algebras are so named because they are the algebras for which the associator is alternating. The associator is a trilinear map given by
By definition, a multilinear map is alternating if it vanishes whenever two of its arguments are equal. The left and right alternative identities for an algebra are equivalent to
Both of these identities together imply that the associator is totally skew-symmetric. That is,
for any permutation "σ". It follows that
for all "x" and "y". This is equivalent to the "flexible identity"
The associator of an alternative algebra is therefore alternating. Conversely, any algebra whose associator is alternating is clearly alternative. By symmetry, any algebra which satisfies any two of:
is alternative and therefore satisfies all three identities.
An alternating associator is always totally skew-symmetric. The converse holds so long as the characteristic of the base field is not 2.
Artin's theorem states that in an alternative algebra the subalgebra generated by any two elements is associative. Conversely, any algebra for which this is true is clearly alternative. It follows that expressions involving only two variables can be written unambiguously without parentheses in an alternative algebra. A generalization of Artin's theorem states that whenever three elements formula_12 in an alternative algebra associate (i.e., formula_13), the subalgebra generated by those elements is associative.
A corollary of Artin's theorem is that alternative algebras are power-associative, that is, the subalgebra generated by a single element is associative. The converse need not hold: the sedenions are power-associative but not alternative.
The Moufang identities
hold in any alternative algebra.
In a unital alternative algebra, multiplicative inverses are unique whenever they exist. Moreover, for any invertible element formula_17 and all formula_18 one has
This is equivalent to saying the associator formula_20 vanishes for all such formula_17 and formula_18. If formula_17 and formula_18 are invertible then formula_25 is also invertible with inverse formula_26. The set of all invertible elements is therefore closed under multiplication and forms a Moufang loop. This "loop of units" in an alternative ring or algebra is analogous to the group of units in an associative ring or algebra.
Kleinfeld's theorem states that any simple non-associative alternative ring is a generalized octonion algebra over its center.
The structure theory of alternative rings is presented in .
The projective plane over any alternative division ring is a Moufang plane.
The close relationship of alternative algebras and composition algebras was given by Guy Roos in 2008: He shows (page 162) the relation for an algebra "A" with unit element "e" and an involutive anti-automorphism formula_27 such that "a" + "a"* and "aa"* are on the line spanned by "e" for all "a" in "A". Use the notation "n"("a") = "aa"*. Then if "n" is a non-singular mapping into the field of "A", and "A" is alternative, then ("A,n") is a composition algebra. | https://en.wikipedia.org/wiki?curid=3160 |
Arbitrage
In economics and finance, arbitrage (, ) is the practice of taking advantage of a price difference between two or more markets: striking a combination of matching deals that capitalize upon the imbalance, the profit being the difference between the market prices at which the unit is traded. When used by academics, an arbitrage is a transaction that involves no negative cash flow at any probabilistic or temporal state and a positive cash flow in at least one state; in simple terms, it is the possibility of a risk-free profit after transaction costs. For example, an arbitrage opportunity is present when there is the possibility to instantaneously buy something for a low price and sell it for a higher price.
In principle and in academic use, an arbitrage is risk-free; in common use, as in statistical arbitrage, it may refer to "expected" profit, though losses may occur, and in practice, there are always risks in arbitrage, some minor (such as fluctuation of prices decreasing profit margins), some major (such as devaluation of a currency or derivative). In academic use, an arbitrage involves taking advantage of differences in price of a "single" asset or "identical" cash-flows; in common use, it is also used to refer to differences between "similar" assets (relative value or convergence trades), as in merger arbitrage.
The term is mainly applied to trading in financial instruments, such as bonds, stocks, derivatives, commodities, and currencies. People who engage in arbitrage are called arbitrageurs .
Arbitrage has the effect of causing prices of the same or very similar assets in different markets to converge.
"Arbitrage" is a French word and denotes a decision by an arbitrator or arbitration tribunal (in modern French, "" usually means referee or umpire). In the sense used here, it was first defined in 1704 by Mathieu de la Porte in his treatise "" as a consideration of different exchange rates to recognise the most profitable places of issuance and settlement for a bill of exchange (" [, in modern spelling] ".)
If the market prices do not allow for profitable arbitrage, the prices are said to constitute an arbitrage equilibrium, or an arbitrage-free market. An arbitrage equilibrium is a precondition for a general economic equilibrium. The "no arbitrage" assumption is used in quantitative finance to calculate a unique risk neutral price for derivatives.
This refers to the method of valuing a coupon-bearing financial instrument by discounting its future cash flows by multiple discount rates. By doing so, a more accurate price can be obtained than if the price is calculated with a present-value pricing approach. Arbitrage-free pricing is used for bond valuation and to detect arbitrage opportunities for investors.
For the purpose of valuing the price of a bond, its cash flows can each be thought of as packets of incremental cash flows with a large packet upon maturity, being the principal. Since the cash flows are dispersed throughout future periods, they must be discounted back to the present. In the present-value approach, the cash flows are discounted with one discount rate to find the price of the bond. In arbitrage-free pricing, multiple discount rates are used.
The present-value approach assumes that the yield of the bond will stay the same until maturity. This is a simplified model because interest rates may fluctuate in the future, which in turn affects the yield on the bond. For this reason, the discount rate may be different for each of the cash flows. Each cash flow can be considered a zero-coupon instrument that pays one payment upon maturity. The discount rates used should be the rates of multiple zero-coupon bonds with maturity dates the same as each cash flow and similar risk as the instrument being valued. By using multiple discount rates, the arbitrage-free price is the sum of the discounted cash flows. Arbitrage-free price refers to the price at which no price arbitrage is possible.
The ideas of using multiple discount rates obtained from zero-coupon bonds and discounting a similar bond's cash flow to find its price is derived from the yield curve, which is a curve of the yields of the same bond with different maturities. This curve can be used to view trends in market expectations of how interest rates will move in the future. In arbitrage-free pricing of a bond, a yield curve of similar zero-coupon bonds with different maturities is created. If the curve were to be created with Treasury securities of different maturities, they would be stripped of their coupon payments through bootstrapping. This is to transform the bonds into zero-coupon bonds. The yield of these zero-coupon bonds would then be plotted on a diagram with time on the "x"-axis and yield on the "y"-axis.
Since the yield curve displays market expectations on how yields and interest rates may move, the arbitrage-free pricing approach is more realistic than using only one discount rate. Investors can use this approach to value bonds and find mismatches in prices, resulting in an arbitrage opportunity. If a bond valued with the arbitrage-free pricing approach turns out to be priced higher in the market, an investor could have such an opportunity:
If the outcome from the valuation were the reverse case, the opposite positions would be taken in the bonds. This arbitrage opportunity comes from the assumption that the prices of bonds with the same properties will converge upon maturity. This can be explained through market efficiency, which states that arbitrage opportunities will eventually be discovered and corrected. The prices of the bonds in t1 move closer together to finally become the same at tT.
Arbitrage is possible when one of three conditions is met:
Arbitrage is not simply the act of buying a product in one market and selling it in another for a higher price at some later time. The transactions must occur "simultaneously" to avoid exposure to market risk, or the risk that prices may change on one market before both transactions are complete. In practical terms, this is generally possible only with securities and financial products that can be traded electronically, and even then, when each leg of the trade is executed, the prices in the market may have moved. Missing one of the legs of the trade (and subsequently having to trade it soon after at a worse price) is called 'execution risk' or more specifically 'leg risk'.
In the simplest example, any good sold in one market should sell for the same price in another. Traders may, for example, find that the price of wheat is lower in agricultural regions than in cities, purchase the good, and transport it to another region to sell at a higher price. This type of price arbitrage is the most common, but this simple example ignores the cost of transport, storage, risk, and other factors. "True" arbitrage requires that there is no market risk involved. Where securities are traded on more than one exchange, arbitrage occurs by simultaneously buying in one and selling on the other.
See rational pricing, particularly § arbitrage mechanics, for further discussion.
Mathematically it is defined as follows:
where formula_2 and formula_3 denotes the portfolio value at time "t".
Arbitrage has the effect of causing prices in different markets to converge. As a result of arbitrage, the currency exchange rates, the price of commodities, and the price of securities in different markets tend to converge. The speed at which they do so is a measure of market efficiency. Arbitrage tends to reduce price discrimination by encouraging people to buy an item where the price is low and resell it where the price is high (as long as the buyers are not prohibited from reselling and the transaction costs of buying, holding, and reselling are small, relative to the difference in prices in the different markets).
Arbitrage moves different currencies toward purchasing power parity. Assume that a car purchased in the United States is cheaper than the same car in Canada. Canadians would buy their cars across the border to exploit the arbitrage condition. At the same time, Americans would buy US cars, transport them across the border, then sell them in Canada. Canadians would have to buy American dollars to buy the cars and Americans would have to sell the Canadian dollars they received in exchange. Both actions would increase demand for US dollars and supply of Canadian dollars. As a result, there would be an appreciation of the US currency. This would make US cars more expensive and Canadian cars less so until their prices were similar. On a larger scale, international arbitrage opportunities in commodities, goods, securities, and currencies tend to change exchange rates until the purchasing power is equal.
In reality, most assets exhibit some difference between countries. These, transaction costs, taxes, and other costs provide an impediment to this kind of arbitrage. Similarly, arbitrage affects the difference in interest rates paid on government bonds issued by the various countries, given the expected depreciation in the currencies relative to each other (see interest rate parity).
Arbitrage transactions in modern securities markets involve fairly low day-to-day risks, but can face extremely high risk in rare situations, particularly financial crises, and can lead to bankruptcy. Formally, arbitrage transactions have negative skew – prices can get a small amount closer (but often no closer than 0), while they can get very far apart. The day-to-day risks are generally small because the transactions involve small differences in price, so an execution failure will generally cause a small loss (unless the trade is very big or the price moves rapidly). The rare case risks are extremely high because these small price differences are converted to large profits via leverage (borrowed money), and in the rare event of a large price move, this may yield a large loss.
The main day-to-day risk is that part of the transaction fails; this is called execution risk. The main, rare risks are counterparty risk, and liquidity risk: that a counterparty to a large transaction or many transactions fails to pay, or that one is required to post margin and does not have the money to do so.
In the academic literature, the idea that seemingly very low risk arbitrage trades might not be fully exploited because of these risk factors and other considerations is often referred to as limits to arbitrage.
Generally it is impossible to close two or three transactions at the same instant; therefore, there is the possibility that when one part of the deal is closed, a quick shift in prices makes it impossible to close the other at a profitable price. However, this is not necessarily the case. Many exchanges and inter-dealer brokers allow multi legged trades (e.g. basis block trades on LIFFE).
Competition in the marketplace can also create risks during arbitrage transactions. As an example, if one was trying to profit from a price discrepancy between IBM on the NYSE and IBM on the London Stock Exchange, they may purchase a large number of shares on the NYSE and find that they cannot simultaneously sell on the LSE. This leaves the arbitrageur in an unhedged risk position.
In the 1980s, risk arbitrage was common. In this form of speculation, one trades a security that is clearly undervalued or overvalued, when it is seen that the wrong valuation is about to be corrected. The standard example is the stock of a company, undervalued in the stock market, which is about to be the object of a takeover bid; the price of the takeover will more truly reflect the value of the company, giving a large profit to those who bought at the current price, if the merger goes through as predicted. Traditionally, arbitrage transactions in the securities markets involve high speed, high volume, and low risk. At some moment a price difference exists, and the problem is to execute two or three balancing transactions while the difference persists (that is, before the other arbitrageurs act). When the transaction involves a delay of weeks or months, as above, it may entail considerable risk if borrowed money is used to magnify the reward through leverage. One way of reducing this risk is through the illegal use of inside information, and risk arbitrage in leveraged buyouts was associated with some of the famous financial scandals of the 1980s, such as those involving Michael Milken and Ivan Boesky.
Another risk occurs if the items being bought and sold are not identical and the arbitrage is conducted under the assumption that the prices of the items are correlated or predictable; this is more narrowly referred to as a convergence trade. In the extreme case this is merger arbitrage, described below. In comparison to the classical quick arbitrage transaction, such an operation can produce disastrous losses.
As arbitrages generally involve "future" movements of cash, they are subject to counterparty risk: the risk that a counterparty fails to fulfill their side of a transaction. This is a serious problem if one has either a single trade or many related trades with a single counterparty, whose failure thus poses a threat, or in the event of a financial crisis when many counterparties fail. This hazard is serious because of the large quantities one must trade in order to make a profit on small price differences.
For example, if one purchases many risky bonds, then hedges them with CDSes, profiting from the difference between the bond spread and the CDS premium, in a financial crisis, the bonds may default "and" the CDS writer/seller may fail, due to the stress of the crisis, causing the arbitrageur to face steep losses.
Arbitrage trades are necessarily synthetic, "leveraged" trades, as they involve a short position. If the assets used are not identical (so a price divergence makes the trade temporarily lose money), or the margin treatment is not identical, and the trader is accordingly required to post margin (faces a margin call), the trader may run out of capital (if they run out of cash and cannot borrow more) and be forced to sell these assets at a loss even though the trades may be expected to ultimately make money. In effect, arbitrage traders synthesize a put option on their ability to finance themselves.
Prices may diverge during a financial crisis, often termed a "flight to quality"; these are precisely the times when it is hardest for leveraged investors to raise capital (due to overall capital constraints), and thus they will lack capital precisely when they need it most.
Also known as geographical arbitrage, this is the simplest form of arbitrage. In spatial arbitrage, an arbitrageur looks for price differences between geographically separate markets. For example, there may be a bond dealer in Virginia offering a bond at 100-12/23 and a dealer in Washington bidding 100-15/23 for the same bond. For whatever reason, the two dealers have not spotted the difference in the prices, but the arbitrageur does. The arbitrageur immediately buys the bond from the Virginia dealer and sells it to the Washington dealer.
Also called risk arbitrage, merger arbitrage generally consists of buying/holding the stock of a company that is the target of a takeover while shorting the stock of the acquiring company.
Usually the market price of the target company is less than the price offered by the acquiring company.
The spread between these two prices depends mainly on the probability and the timing of the takeover being completed as well as the prevailing level of interest rates.
The bet in a merger arbitrage is that such a spread will eventually be zero, if and when the takeover is completed. The risk is that the deal "breaks" and the spread massively widens.
Also called "municipal bond relative value arbitrage", "municipal arbitrage", or just "muni arb", this hedge fund strategy involves one of two approaches. The term "arbitrage" is also used in the context of the Income Tax Regulations governing the investment of proceeds of municipal bonds; these regulations, aimed at the issuers or beneficiaries of tax-exempt municipal bonds, are different and, instead, attempt to remove the issuer's ability to arbitrage between the low tax-exempt rate and a taxable investment rate.
Generally, managers seek relative value opportunities by being both long and short municipal bonds with a duration-neutral book. The relative value trades may be between different issuers, different bonds issued by the same entity, or capital structure trades referencing the same asset (in the case of revenue bonds). Managers aim to capture the inefficiencies arising from the heavy participation of non-economic investors (i.e., high income "buy and hold" investors seeking tax-exempt income) as well as the "crossover buying" arising from corporations' or individuals' changing income tax situations (i.e., insurers switching their munis for corporates after a large loss as they can capture a higher after-tax yield by offsetting the taxable corporate income with underwriting losses). There are additional inefficiencies arising from the highly fragmented nature of the municipal bond market which has two million outstanding issues and 50,000 issuers, in contrast to the Treasury market which has 400 issues and a single issuer.
Second, managers construct leveraged portfolios of AAA- or AA-rated tax-exempt municipal bonds with the duration risk hedged by shorting the appropriate ratio of taxable corporate bonds. These corporate equivalents are typically interest rate swaps referencing Libor or SIFMA. The arbitrage manifests itself in the form of a relatively cheap longer maturity municipal bond, which is a municipal bond that yields significantly more than 65% of a corresponding taxable corporate bond. The steeper slope of the municipal yield curve allows participants to collect more after-tax income from the municipal bond portfolio than is spent on the interest rate swap; the carry is greater than the hedge expense. Positive, tax-free carry from muni arb can reach into the double digits. The bet in this municipal bond arbitrage is that, over a longer period of time, two similar instruments—municipal bonds and interest rate swaps—will correlate with each other; they are both very high quality credits, have the same maturity and are denominated in the same currency. Credit risk and duration risk are largely eliminated in this strategy. However, basis risk arises from use of an imperfect hedge, which results in significant, but range-bound principal volatility. The end goal is to limit this principal volatility, eliminating its relevance over time as the high, consistent, tax-free cash flow accumulates. Since the inefficiency is related to government tax policy, and hence is structural in nature, it has not been arbitraged away.
However, many municipal bonds are callable, and this adds substantial risks to the strategy.
A convertible bond is a bond that an investor can return to the issuing company in exchange for a predetermined number of shares in the company.
A convertible bond can be thought of as a corporate bond with a stock call option attached to it.
The price of a convertible bond is sensitive to three major factors:
Given the complexity of the calculations involved and the convoluted structure that a convertible bond can have, an arbitrageur often relies on sophisticated quantitative models in order to identify bonds that are trading cheap versus their theoretical value.
Convertible arbitrage consists of buying a convertible bond and hedging two of the three factors in order to gain exposure to the third factor at a very attractive price.
For instance an arbitrageur would first buy a convertible bond, then sell fixed income securities or interest rate futures (to hedge the interest rate exposure) and buy some credit protection (to hedge the risk of credit deterioration).
Eventually what he'd be left with is something similar to a call option on the underlying stock, acquired at a very low price.
He could then make money either selling some of the more expensive options that are openly traded in the market or delta hedging his exposure to the underlying shares.
A depositary receipt is a security that is offered as a "tracking stock" on another foreign market. For instance, a Chinese company wishing to raise more money may issue a depository receipt on the New York Stock Exchange, as the amount of capital on the local exchanges is limited. These securities, known as ADRs (American depositary receipt) or GDRs (global depository receipt) depending on where they are issued, are typically considered "foreign" and therefore trade at a lower value when first released. Many ADR's are exchangeable into the original security (known as fungibility) and actually have the same value. In this case there is a spread between the perceived value and real value, which can be extracted. Other ADR's that are not exchangeable often have much larger spreads. Since the ADR is trading at a value lower than what it is worth, one can purchase the ADR and expect to make money as its value converges on the original. However, there is a chance that the original stock will fall in value too, so by shorting it one can hedge that risk.
Cross-border arbitrage exploits different prices of the same stock in different countries:
Example: Apple is trading on NASDAQ at US$108.84. The stock is also traded on the German electronic exchange, XETRA. If 1 euro costs US$1.11, a cross-border trader could enter a buy order on the XETRA at €98.03 per Apple share and a sell order at €98.07 per share.
Some brokers in Germany do not offer access to the U.S. exchanges. Hence if a German retail investor wants to buy Apple stock, he needs to buy it on the XETRA. The cross-border trader would sell the Apple shares on XETRA to the investor and buy the shares in the same second on NASDAQ. Afterwards, the cross-border trader would need to transfer the shares bought on NASDAQ to the German XETRA exchange, where he is obliged to deliver the stock.
In most cases, the quotation on the local exchanges is done electronically by high-frequency traders, taking into consideration the home price of the stock and the exchange rate. This kind of high-frequency trading benefits the public as it reduces the cost to the German investor and enables him to buy U.S. shares.
A dual-listed company (DLC) structure involves two companies incorporated in different countries contractually agreeing to operate their businesses as if they were a single enterprise, while retaining their separate legal identity and existing stock exchange listings. In integrated and efficient financial markets, stock prices of the twin pair should move in lockstep. In practice, DLC share prices exhibit large deviations from theoretical parity. Arbitrage positions in DLCs can be set up by obtaining a long position in the relatively underpriced part of the DLC and a short position in the relatively overpriced part. Such arbitrage strategies start paying off as soon as the relative prices of the two DLC stocks converge toward theoretical parity. However, since there is no identifiable date at which DLC prices will converge, arbitrage positions sometimes have to be kept open for considerable periods of time. In the meantime, the price gap might widen. In these situations, arbitrageurs may receive margin calls, after which they would most likely be forced to liquidate part of the position at a highly unfavorable moment and suffer a loss. Arbitrage in DLCs may be profitable, but is also very risky.
A good illustration of the risk of DLC arbitrage is the position in Royal Dutch Shell—which had a DLC structure until 2005—by the hedge fund Long-Term Capital Management (LTCM, see also the discussion below). Lowenstein (2000) describes that LTCM established an arbitrage position in Royal Dutch Shell in the summer of 1997, when Royal Dutch traded at an 8 to 10 percent premium. In total, $2.3 billion was invested, half of which was long in Shell and the other half was short in Royal Dutch (Lowenstein, p. 99). In the autumn of 1998, large defaults on Russian debt created significant losses for the hedge fund and LTCM had to unwind several positions. Lowenstein reports that the premium of Royal Dutch had increased to about 22 percent and LTCM had to close the position and incur a loss. According to Lowenstein (p. 234), LTCM lost $286 million in equity pairs trading and more than half of this loss is accounted for by the Royal Dutch Shell trade. (See further under Limits to arbitrage.)
The market prices for privately held companies are typically viewed from a return on investment perspective (such as 25%), whilst publicly held and or exchange listed companies trade on a Price to earnings ratio (P/E) (such as a P/E of 10, which equates to a 10% ROI). Thus, if a publicly traded company specialises in the acquisition of privately held companies, from a per-share perspective there is a gain with every acquisition that falls within these guidelines. E.g., Berkshire Hathaway and Halydean Corporation. Private to public equities arbitrage is a term which can arguably be applied to investment banking in general. Private markets to public markets differences may also help explain the overnight windfall gains enjoyed by principals of companies that just did an initial public offering (IPO).
Regulatory arbitrage "is an avoidance strategy of regulation that is exercised as a result of a regulatory inconsistency". In other words, where a regulated institution takes advantage of the difference between its real (or economic) risk and the regulatory position. For example, if a bank, operating under the Basel I accord, has to hold 8% capital against default risk, but the real risk of default is lower, it is profitable to securitise the loan, removing the low risk loan from its portfolio. On the other hand, if the real risk is higher than the regulatory risk then it is profitable to make that loan and hold on to it, provided it is priced appropriately. Regulatory arbitrage can result in parts of entire businesses being unregulated as a result of the arbitrage.
This process can increase the overall riskiness of institutions under a risk insensitive regulatory regime, as described by Alan Greenspan in his October 1998 speech on The Role of Capital in Optimal Banking Supervision and Regulation.
The term "Regulatory Arbitrage" was used for the first time in 2005 when it was applied by Scott V. Simpson, a partner at law firm Skadden, Arps, to refer to a new defence tactic in hostile mergers and acquisitions where differing takeover regimes in deals involving multi-jurisdictions are exploited to the advantage of a target company under threat.
In economics, regulatory arbitrage (sometimes, tax arbitrage) may refer to situations when a company can choose a nominal place of business with a regulatory, legal or tax regime with lower costs. This can occur particularly where the business transaction has no obvious physical location. In the case of many financial products, it may be unclear "where" the transaction occurs.
Regulatory arbitrage can include restructuring a bank by outsourcing services such as IT. The outsourcing company takes over the installations, buying out the bank's assets and charges a periodic service fee back to the bank. This frees up cashflow usable for new lending by the bank. The bank will have higher IT costs, but counts on the multiplier effect of money creation and the interest rate spread to make it a profitable exercise.
Example:
Suppose the bank sells its IT installations for US$40 million. With a reserve ratio of 10%, the bank can create US$400 million in additional loans (there is a time lag, and the bank has to expect to recover the loaned money back into its books). The bank can often lend (and securitize the loan) to the IT services company to cover the acquisition cost of the IT installations. This can be at preferential rates, as the sole client using the IT installation is the bank. If the bank can generate 5% interest margin on the 400 million of new loans, the bank will increase interest revenues by 20 million. The IT services company is free to leverage their balance sheet as aggressively as they and their banker agree to. This is the reason behind the trend towards outsourcing in the financial sector. Without this money creation benefit, it is actually more expensive to outsource the IT operations as the outsourcing adds a layer of management and increases overhead.
According to PBS Frontline's 2012 four-part documentary, "Money, Power, and Wall Street," regulatory arbitrage, along with asymmetric bank lobbying in Washington and abroad, allowed investment banks in the pre- and post-2008 period to continue to skirt laws and engage in the risky proprietary trading of opaque derivatives, swaps, and other credit-based instruments invented to circumvent legal restrictions at the expense of clients, government, and publics.
Due to the Affordable Care Act's expansion of Medicaid coverage, one form of Regulatory Arbitrage can now be found when businesses engage in “Medicaid Migration”, a maneuver by which qualifying employees who would typically be enrolled in company health plans elect to enroll in Medicaid instead. These programs that have similar characteristics as insurance products to the employee, but have radically different cost structures, resulting in significant expense reductions for employers.
Telecom arbitrage companies allow phone users to make international calls for free through certain access numbers. Such services are offered in the United Kingdom; the telecommunication arbitrage companies get paid an interconnect charge by the UK mobile networks and then buy international routes at a lower cost. The calls are seen as free by the UK contract mobile phone customers since they are using up their allocated monthly minutes rather than paying for additional calls.
Such services were previously offered in the United States by companies such as FuturePhone.com. These services would operate in rural telephone exchanges, primarily in small towns in the state of Iowa. In these areas, the local telephone carriers are allowed to charge a high "termination fee" to the caller's carrier in order to fund the cost of providing service to the small and sparsely populated areas that they serve. However, FuturePhone (as well as other similar services) ceased operations upon legal challenges from AT&T and other service providers.
Statistical arbitrage is an imbalance in expected nominal values. A casino has a statistical arbitrage in every game of chance that it offers, referred to as the house advantage, house edge, vigorish, or house vigorish.
Long-Term Capital Management (LTCM) lost 4.6 billion U.S. dollars in fixed income arbitrage in September 1998. LTCM had attempted to make money on the price difference between different bonds. For example, it would sell U.S. Treasury securities and buy Italian bond futures. The concept was that because Italian bond futures had a less liquid market, in the short term Italian bond futures would have a higher return than U.S. bonds, but in the long term, the prices would converge. Because the difference was small, a large amount of money had to be borrowed to make the buying and selling profitable.
The downfall in this system began on August 17, 1998, when Russia defaulted on its ruble debt and domestic dollar debt. Because the markets were already nervous due to the 1997 Asian financial crisis, investors began selling non-U.S. treasury debt and buying U.S. treasuries, which were considered a safe investment. As a result, the price on US treasuries began to increase and the return began decreasing because there were many buyers, and the return (yield) on other bonds began to increase because there were many sellers (i.e. the price of those bonds fell). This caused the difference between the prices of U.S. treasuries and other bonds to increase, rather than to decrease as LTCM was expecting. Eventually this caused LTCM to fold, and their creditors had to arrange a bail-out. More controversially, officials of the Federal Reserve assisted in the negotiations that led to this bail-out, on the grounds that so many companies and deals were intertwined with LTCM that if LTCM actually failed, they would as well, causing a collapse in confidence in the economic system. Thus LTCM failed as a fixed income arbitrage fund, although it is unclear what sort of profit was realized by the banks that bailed LTCM out. | https://en.wikipedia.org/wiki?curid=3162 |
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