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Contents Black hole A black hole is an astronomical body so compact that its gravity prevents anything, including light, from escaping. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. The boundary of no escape is called the event horizon. In general relativity, a black hole's event horizon seals an object's fate but produces no locally detectable change when crossed. General relativity also predicts that every black hole should have a central singularity, where the curvature of spacetime is infinite. In many ways, a black hole acts like an ideal black body, as it reflects no light. Quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. In 1916, Karl Schwarzschild found the first modern solution of general relativity that would characterise a black hole. Due to his influential research, the Schwarzschild metric is named after him. David Finkelstein, in 1958, first interpreted Schwarzschild's model as a region of space from which nothing can escape. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The first black hole known was Cygnus X-1, identified by several researchers independently in 1971. Black holes typically form when massive stars collapse at the end of their life cycle. After a black hole has formed, it can grow by absorbing mass from its surroundings. Supermassive black holes of millions of solar masses may form by absorbing other stars and merging with other black holes, or via direct collapse of gas clouds. There is consensus that supermassive black holes exist in the centres of most galaxies. The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter falling toward a black hole can form an accretion disk of infalling plasma, heated by friction and emitting light. In extreme cases, this creates a quasar, some of the brightest objects in the universe. Merging black holes can also be detected by observation of the gravitational waves they emit. If other stars are orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses. History The idea of a body so massive that even light could not escape was first proposed in the late 18th century by English astronomer and clergyman John Michell and independently by French scientist Pierre-Simon Laplace. Both scholars proposed very large stars in contrast to the modern concept of an extremely dense object. Michell's idea, in a short part of a letter published in 1784, calculated that a star with the same density but 500 times the radius of the sun would not let any emitted light escape; the surface escape velocity would exceed the speed of light.: 122 Michell correctly hypothesized that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies. In 1796, Laplace mentioned that a star could be invisible if it were sufficiently large while speculating on the origin of the Solar System in his book Exposition du Système du Monde. Franz Xaver von Zach asked Laplace for a mathematical analysis, which Laplace provided and published in a journal edited by von Zach. In 1905, Albert Einstein showed that the laws of electromagnetism would be invariant under a Lorentz transformation: they would be identical for observers travelling at different velocities relative to each other. This discovery became known as the principle of special relativity. Although the laws of mechanics had already been shown to be invariant, gravity remained yet to be included.: 19 In 1907, Einstein published a paper proposing his equivalence principle, the hypothesis that inertial mass and gravitational mass have a common cause. Using the principle, Einstein predicted the redshift and half of the lensing effect of gravity on light; the full prediction of gravitational lensing required development of general relativity.: 19 By 1915, Einstein refined these ideas into his general theory of relativity, which explained how matter affects spacetime, which in turn affects the motion of other matter. This formed the basis for black hole physics. Only a few months after Einstein published the field equations describing general relativity, astrophysicist Karl Schwarzschild set out to apply the idea to stars. He assumed spherical symmetry with no spin and found a solution to Einstein's equations.: 124 A few months after Schwarzschild, Johannes Droste, a student of Hendrik Lorentz, independently gave the same solution. At a certain radius from the center of the mass, the Schwarzschild solution became singular, meaning that some of the terms in the Einstein equations became infinite. The nature of this radius, which later became known as the Schwarzschild radius, was not understood at the time. Many physicists of the early 20th century were skeptical of the existence of black holes. In a 1926 popular science book, Arthur Eddington critiqued the idea of a star with mass compressed to its Schwarzschild radius as a flaw in the then-poorly-understood theory of general relativity.: 134 In 1939, Einstein himself used his theory of general relativity in an attempt to prove that black holes were impossible. His work relied on increasing pressure or increasing centrifugal force balancing the force of gravity so that the object would not collapse beyond its Schwarzschild radius. He missed the possibility that implosion would drive the system below this critical value.: 135 By the 1920s, astronomers had classified a number of white dwarf stars as too cool and dense to be explained by the gradual cooling of ordinary stars. In 1926, Ralph Fowler showed that quantum-mechanical degeneracy pressure was larger than thermal pressure at these densities.: 145 In 1931, Subrahmanyan Chandrasekhar calculated that a non-rotating body of electron-degenerate matter below a certain limiting mass is stable, and by 1934 he showed that this explained the catalog of white dwarf stars.: 151 When Chandrasekhar announced his results, Eddington pointed out that stars above this limit would radiate until they were sufficiently dense to prevent light from exiting, a conclusion he considered absurd. Eddington and, later, Lev Landau argued that some yet unknown mechanism would stop the collapse. In the 1930s, Fritz Zwicky and Walter Baade studied stellar novae, focusing on exceptionally bright ones they called supernovae. Zwicky promoted the idea that supernovae produced stars with the density of atomic nuclei—neutron stars—but this idea was largely ignored.: 171 In 1939, based on Chandrasekhar's reasoning, J. Robert Oppenheimer and George Volkoff predicted that neutron stars below a certain mass limit, later called the Tolman–Oppenheimer–Volkoff limit, would be stable due to neutron degeneracy pressure. Above that limit, they reasoned that either their model would not apply or that gravitational contraction would not stop.: 380 John Archibald Wheeler and two of his students resolved questions about the model behind the Tolman–Oppenheimer–Volkoff (TOV) limit. Harrison and Wheeler developed the equations of state relating density to pressure for cold matter all the way through electron degeneracy and neutron degeneracy. Masami Wakano and Wheeler then used the equations to compute the equilibrium curve for stars, relating mass to circumference. They found no additional features that would invalidate the TOV limit. This meant that the only thing that could prevent black holes from forming was a dynamic process ejecting sufficient mass from a star as it cooled.: 205 The modern concept of black holes was formulated by Robert Oppenheimer and his student Hartland Snyder in 1939.: 80 In the paper, Oppenheimer and Snyder solved Einstein's equations of general relativity for an idealized imploding star, in a model later called the Oppenheimer–Snyder model, then described the results from far outside the star. The implosion starts as one might expect: the star material rapidly collapses inward. However, as the density of the star increases, gravitational time dilation increases and the collapse, viewed from afar, seems to slow down further and further until the star reaches its Schwarzschild radius, where it appears frozen in time.: 217 In 1958, David Finkelstein identified the Schwarzschild surface as an event horizon, calling it "a perfect unidirectional membrane: causal influences can cross it in only one direction". In this sense, events that occur inside of the black hole cannot affect events that occur outside of the black hole. Finkelstein created a new reference frame to include the point of view of infalling observers.: 103 Finkelstein's new frame of reference allowed events at the surface of an imploding star to be related to events far away. By 1962 the two points of view were reconciled, convincing many skeptics that implosion into a black hole made physical sense.: 226 The era from the mid-1960s to the mid-1970s was the "golden age of black hole research", when general relativity and black holes became mainstream subjects of research.: 258 In this period, more general black hole solutions were found. In 1963, Roy Kerr found the exact solution for a rotating black hole. Two years later, Ezra Newman found the cylindrically symmetric solution for a black hole that is both rotating and electrically charged. In 1967, Werner Israel found that the Schwarzschild solution was the only possible solution for a nonspinning, uncharged black hole, meaning that a Schwarzschild black hole would be defined by its mass alone. Similar identities were later found for Reissner-Nordstrom and Kerr black holes, defined only by their mass and their charge or spin respectively. Together, these findings became known as the no-hair theorem, which states that a stationary black hole is completely described by the three parameters of the Kerr–Newman metric: mass, angular momentum, and electric charge. At first, it was suspected that the strange mathematical singularities found in each of the black hole solutions only appeared due to the assumption that a black hole would be perfectly spherically symmetric, and therefore the singularities would not appear in generic situations where black holes would not necessarily be symmetric. This view was held in particular by Vladimir Belinski, Isaak Khalatnikov, and Evgeny Lifshitz, who tried to prove that no singularities appear in generic solutions, although they would later reverse their positions. However, in 1965, Roger Penrose proved that general relativity without quantum mechanics requires that singularities appear in all black holes. Astronomical observations also made great strides during this era. In 1967, Antony Hewish and Jocelyn Bell Burnell discovered pulsars and by 1969, these were shown to be rapidly rotating neutron stars. Until that time, neutron stars, like black holes, were regarded as just theoretical curiosities, but the discovery of pulsars showed their physical relevance and spurred a further interest in all types of compact objects that might be formed by gravitational collapse. Based on observations in Greenwich and Toronto in the early 1970s, Cygnus X-1, a galactic X-ray source discovered in 1964, became the first astronomical object commonly accepted to be a black hole. Work by James Bardeen, Jacob Bekenstein, Carter, and Hawking in the early 1970s led to the formulation of black hole thermodynamics. These laws describe the behaviour of a black hole in close analogy to the laws of thermodynamics by relating mass to energy, area to entropy, and surface gravity to temperature. The analogy was completed: 442 when Hawking, in 1974, showed that quantum field theory implies that black holes should radiate like a black body with a temperature proportional to the surface gravity of the black hole, predicting the effect now known as Hawking radiation. While Cygnus X-1, a stellar-mass black hole, was generally accepted by the scientific community as a black hole by the end of 1973, it would be decades before a supermassive black hole would gain the same broad recognition. Although, as early as the 1960s, physicists such as Donald Lynden-Bell and Martin Rees had suggested that powerful quasars in the center of galaxies were powered by accreting supermassive black holes, little observational proof existed at the time. However, the Hubble Space Telescope, launched decades later, found that supermassive black holes were not only present in these active galactic nuclei, but that supermassive black holes in the center of galaxies were ubiquitous: Almost every galaxy had a supermassive black hole at its center, many of which were quiescent. In 1999, David Merritt proposed the M–sigma relation, which related the dispersion of the velocity of matter in the center bulge of a galaxy to the mass of the supermassive black hole at its core. Subsequent studies confirmed this correlation. Around the same time, based on telescope observations of the velocities of stars at the center of the Milky Way galaxy, independent work groups led by Andrea Ghez and Reinhard Genzel concluded that the compact radio source in the center of the galaxy, Sagittarius A*, was likely a supermassive black hole. On 11 February 2016, the LIGO Scientific Collaboration and Virgo Collaboration announced the first direct detection of gravitational waves, named GW150914, representing the first observation of a black hole merger. At the time of the merger, the black holes were approximately 1.4 billion light-years away from Earth and had masses of 30 and 35 solar masses.: 6 In 2017, Rainer Weiss, Kip Thorne, and Barry Barish, who had spearheaded the project, were awarded the Nobel Prize in Physics for their work. Since the initial discovery in 2015, hundreds more gravitational waves have been observed by LIGO and another interferometer, Virgo. On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope (EHT) in 2017 of the supermassive black hole in Messier 87's galactic centre. In 2022, the Event Horizon Telescope collaboration released an image of the black hole in the center of the Milky Way galaxy, Sagittarius A*; The data had been collected in 2017. In 2020, the Nobel Prize in Physics was awarded for work on black holes. Andrea Ghez and Reinhard Genzel shared one-half for their discovery that Sagittarius A* is a supermassive black hole. Penrose received the other half for his work showing that the mathematics of general relativity requires the formation of black holes. Cosmologists lamented that Hawking's extensive theoretical work on black holes would not be honored since he died in 2018. In December 1967, a student reportedly suggested the phrase black hole at a lecture by John Wheeler; Wheeler adopted the term for its brevity and "advertising value", and Wheeler's stature in the field ensured it quickly caught on, leading some to credit Wheeler with coining the phrase. However, the term was used by others around that time. Science writer Marcia Bartusiak traces the term black hole to physicist Robert H. Dicke, who in the early 1960s reportedly compared the phenomenon to the Black Hole of Calcutta, notorious as a prison where people entered but never left alive. The term was used in print by Life and Science News magazines in 1963, and by science journalist Ann Ewing in her article "'Black Holes' in Space", dated 18 January 1964, which was a report on a meeting of the American Association for the Advancement of Science held in Cleveland, Ohio. Definition A black hole is generally defined as a region of spacetime from which no information-carrying signals or objects can escape. However, verifying an object as a black hole by this definition would require waiting for an infinite time and at an infinite distance from the black hole to verify that indeed, nothing has escaped, and thus cannot be used to identify a physical black hole. Broadly, physicists do not have a precisely-agreed-upon definition of a black hole. Among astrophysicists, a black hole is a compact object with a mass larger than four solar masses. A black hole may also be defined as a reservoir of information: 142 or a region where space is falling inwards faster than the speed of light. Properties The no-hair theorem postulates that, once it achieves a stable condition after formation, a black hole has only three independent physical properties: mass, electric charge, and angular momentum; the black hole is otherwise featureless. If the conjecture is true, any two black holes that share the same values for these properties, or parameters, are indistinguishable from one another. The degree to which the conjecture is true for real black holes is currently an unsolved problem. The simplest static black holes have mass but neither electric charge nor angular momentum. According to Birkhoff's theorem, these Schwarzschild black holes are the only vacuum solution that is spherically symmetric. Solutions describing more general black holes also exist. Non-rotating charged black holes are described by the Reissner–Nordström metric, while the Kerr metric describes a non-charged rotating black hole. The most general stationary black hole solution known is the Kerr–Newman metric, which describes a black hole with both charge and angular momentum. The simplest static black holes have mass but neither electric charge nor angular momentum. Contrary to the popular notion of a black hole "sucking in everything" in its surroundings, from far away, the external gravitational field of a black hole is identical to that of any other body of the same mass. While a black hole can theoretically have any positive mass, the charge and angular momentum are constrained by the mass. The total electric charge Q and the total angular momentum J are expected to satisfy the inequality Q 2 4 π ϵ 0 + c 2 J 2 G M 2 ≤ G M 2 {\displaystyle {\frac {Q^{2}}{4\pi \epsilon _{0}}}+{\frac {c^{2}J^{2}}{GM^{2}}}\leq GM^{2}} for a black hole of mass M. Black holes with the maximum possible charge or spin satisfying this inequality are called extremal black holes. Solutions of Einstein's equations that violate this inequality exist, but they do not possess an event horizon. These are so-called naked singularities that can be observed from the outside. Because these singularities make the universe inherently unpredictable, many physicists believe they could not exist. The weak cosmic censorship hypothesis, proposed by Sir Roger Penrose, rules out the formation of such singularities, when they are created through the gravitational collapse of realistic matter. However, this theory has not yet been proven, and some physicists believe that naked singularities could exist. It is also unknown whether black holes could even become extremal, forming naked singularities, since natural processes counteract increasing spin and charge when a black hole becomes near-extremal. The total mass of a black hole can be estimated by analyzing the motion of objects near the black hole, such as stars or gas. All black holes spin, often fast—One supermassive black hole, GRS 1915+105 has been estimated to spin at over 1,000 revolutions per second. The Milky Way's central black hole Sagittarius A* rotates at about 90% of the maximum rate. The spin rate can be inferred from measurements of atomic spectral lines in the X-ray range. As gas near the black hole plunges inward, high energy X-ray emission from electron-positron pairs illuminates the gas further out, appearing red-shifted due to relativistic effects. Depending on the spin of the black hole, this plunge happens at different radii from the hole, with different degrees of redshift. Astronomers can use the gap between the x-ray emission of the outer disk and the redshifted emission from plunging material to determine the spin of the black hole. A newer way to estimate spin is based on the temperature of gasses accreting onto the black hole. The method requires an independent measurement of the black hole mass and inclination angle of the accretion disk followed by computer modeling. Gravitational waves from coalescing binary black holes can also provide the spin of both progenitor black holes and the merged hole, but such events are rare. A spinning black hole has angular momentum. The supermassive black hole in the center of the Messier 87 (M87) galaxy appears to have an angular momentum very close to the maximum theoretical value. That uncharged limit is J ≤ G M 2 c , {\displaystyle J\leq {\frac {GM^{2}}{c}},} allowing definition of a dimensionless spin magnitude such that 0 ≤ c J G M 2 ≤ 1. {\displaystyle 0\leq {\frac {cJ}{GM^{2}}}\leq 1.} Most black holes are believed to have an approximately neutral charge. For example, Michal Zajaček, Arman Tursunov, Andreas Eckart, and Silke Britzen found the electric charge of Sagittarius A* to be at least ten orders of magnitude below the theoretical maximum. A charged black hole repels other like charges just like any other charged object. If a black hole were to become charged, particles with an opposite sign of charge would be pulled in by the extra electromagnetic force, while particles with the same sign of charge would be repelled, neutralizing the black hole. This effect may not be as strong if the black hole is also spinning. The presence of charge can reduce the diameter of the black hole by up to 38%. The charge Q for a nonspinning black hole is bounded by Q ≤ G M , {\displaystyle Q\leq {\sqrt {G}}M,} where G is the gravitational constant and M is the black hole's mass. Classification Black holes can have a wide range of masses. The minimum mass of a black hole formed by stellar gravitational collapse is governed by the maximum mass of a neutron star and is believed to be approximately two-to-four solar masses. However, theoretical primordial black holes, believed to have formed soon after the Big Bang, could be far smaller, with masses as little as 10−5 grams at formation. These very small black holes are sometimes called micro black holes. Black holes formed by stellar collapse are called stellar black holes. Estimates of their maximum mass at formation vary, but generally range from 10 to 100 solar masses, with higher estimates for black holes progenated by low-metallicity stars. The mass of a black hole formed via a supernova has a lower bound: If the progenitor star is too small, the collapse may be stopped by the degeneracy pressure of the star's constituents, allowing the condensation of matter into an exotic denser state. Degeneracy pressure occurs from the Pauli exclusion principle—Particles will resist being in the same place as each other. Smaller progenitor stars, with masses less than about 8 M☉, will be held together by the degeneracy pressure of electrons and will become a white dwarf. For more massive progenitor stars, electron degeneracy pressure is no longer strong enough to resist the force of gravity and the star will be held together by neutron degeneracy pressure, which can occur at much higher densities, forming a neutron star. If the star is still too massive, even neutron degeneracy pressure will not be able to resist the force of gravity and the star will collapse into a black hole.: 5.8 Stellar black holes can also gain mass via accretion of nearby matter, often from a companion object such as a star. Black holes that are larger than stellar black holes but smaller than supermassive black holes are called intermediate-mass black holes, with masses of approximately 102 to 105 solar masses. These black holes seem to be rarer than their stellar and supermassive counterparts, with relatively few candidates having been observed. Physicists have speculated that such black holes may form from collisions in globular and star clusters or at the center of low-mass galaxies. They may also form as the result of mergers of smaller black holes, with several LIGO observations finding merged black holes within the 110-350 solar mass range. The black holes with the largest masses are called supermassive black holes, with masses more than 106 times that of the Sun. These black holes are believed to exist at the centers of almost every large galaxy, including the Milky Way. Some scientists have proposed a subcategory of even larger black holes, called ultramassive black holes, with masses greater than 109-1010 solar masses. Theoretical models predict that the accretion disc that feeds black holes will be unstable once a black hole reaches 50-100 billion times the mass of the Sun, setting a rough upper limit to black hole mass. Structure While black holes are conceptually invisible sinks of all matter and light, in astronomical settings, their enormous gravity alters the motion of surrounding objects and pulls nearby gas inwards at near-light speed, making the area around black holes the brightest objects in the universe. Some black holes have relativistic jets—thin streams of plasma travelling away from the black hole at more than one-tenth of the speed of light. A small faction of the matter falling towards the black hole gets accelerated away along the hole rotation axis. These jets can extend as far as millions of parsecs from the black hole itself. Black holes of any mass can have jets. However, they are typically observed around spinning black holes with strongly-magnetized accretion disks. Relativistic jets were more common in the early universe, when galaxies and their corresponding supermassive black holes were rapidly gaining mass. All black holes with jets also have an accretion disk, but the jets are usually brighter than the disk. Quasars, typically found in other galaxies, are believed to be supermassive black holes with jets; microquasars are believed to be stellar-mass objects with jets, typically observed in the Milky Way. The mechanism of formation of jets is not yet known, but several options have been proposed. One method proposed to fuel these jets is the Blandford-Znajek process, which suggests that the dragging of magnetic field lines by a black hole's rotation could launch jets of matter into space. The Penrose process, which involves extraction of a black hole's rotational energy, has also been proposed as a potential mechanism of jet propulsion. Due to conservation of angular momentum, gas falling into the gravitational well created by a massive object will typically form a disk-like structure around the object.: 242 As the disk's angular momentum is transferred outward due to internal processes, its matter falls farther inward, converting its gravitational energy into heat and releasing a large flux of x-rays. The temperature of these disks can range from thousands to millions of Kelvin, and temperatures can differ throughout a single accretion disk. Accretion disks can also emit in other parts of the electromagnetic spectrum, depending on the disk's turbulence and magnetization and the black hole's mass and angular momentum. Accretion disks can be defined as geometrically thin or geometrically thick. Geometrically thin disks are mostly confined to the black hole's equatorial plane and have a well-defined edge at the innermost stable circular orbit (ISCO), while geometrically thick disks are supported by internal pressure and temperature and can extend inside the ISCO. Disks with high rates of electron scattering and absorption, appearing bright and opaque, are called optically thick; optically thin disks are more translucent and produce fainter images when viewed from afar. Accretion disks of black holes accreting beyond the Eddington limit are often referred to as polish donuts due to their thick, toroidal shape that resembles that of a donut. Quasar accretion disks are expected to usually appear blue in color. The disk for a stellar black hole, on the other hand, would likely look orange, yellow, or red, with its inner regions being the brightest. Theoretical research suggests that the hotter a disk is, the bluer it should be, although this is not always supported by observations of real astronomical objects. Accretion disk colors may also be altered by the Doppler effect, with the part of the disk travelling towards an observer appearing bluer and brighter and the part of the disk travelling away from the observer appearing redder and dimmer. In Newtonian gravity, test particles can stably orbit at arbitrary distances from a central object. In general relativity, however, there exists a smallest possible radius for which a massive particle can orbit stably. Any infinitesimal inward perturbations to this orbit will lead to the particle spiraling into the black hole, and any outward perturbations will, depending on the energy, cause the particle to spiral in, move to a stable orbit further from the black hole, or escape to infinity. This orbit is called the innermost stable circular orbit, or ISCO. The location of the ISCO depends on the spin of the black hole and the spin of the particle itself. In the case of a Schwarzschild black hole (spin zero) and a particle without spin, the location of the ISCO is: r I S C O = 3 r s = 6 G M c 2 , {\displaystyle r_{\rm {ISCO}}=3\,r_{\text{s}}={\frac {6\,GM}{c^{2}}},} where r I S C O {\displaystyle r_{\rm {_{ISCO}}}} is the radius of the ISCO, r s {\displaystyle r_{\text{s}}} is the Schwarzschild radius of the black hole, G {\displaystyle G} is the gravitational constant, and c {\displaystyle c} is the speed of light. The radius of this orbit changes slightly based on particle spin. For charged black holes, the ISCO moves inwards. For spinning black holes, the ISCO is moved inwards for particles orbiting in the same direction that the black hole is spinning (prograde) and outwards for particles orbiting in the opposite direction (retrograde). For example, the ISCO for a particle orbiting retrograde can be as far out as about 9 r s {\displaystyle 9r_{\text{s}}} , while the ISCO for a particle orbiting prograde can be as close as at the event horizon itself. The photon sphere is a spherical boundary for which photons moving on tangents to that sphere are bent completely around the black hole, possibly orbiting multiple times. Light rays with impact parameters less than the radius of the photon sphere enter the black hole. For Schwarzschild black holes, the photon sphere has a radius 1.5 times the Schwarzschild radius; the radius for non-Schwarzschild black holes is at least 1.5 times the radius of the event horizon. When viewed from a great distance, the photon sphere creates an observable black hole shadow. Since no light emerges from within the black hole, this shadow is the limit for possible observations.: 152 The shadow of colliding black holes should have characteristic warped shapes, allowing scientists to detect black holes that are about to merge. While light can still escape from the photon sphere, any light that crosses the photon sphere on an inbound trajectory will be captured by the black hole. Therefore, any light that reaches an outside observer from the photon sphere must have been emitted by objects between the photon sphere and the event horizon. Light emitted towards the photon sphere may also curve around the black hole and return to the emitter. For a rotating, uncharged black hole, the radius of the photon sphere depends on the spin parameter and whether the photon is orbiting prograde or retrograde. For a photon orbiting prograde, the photon sphere will be 1-3 Schwarzschild radii from the center of the black hole, while for a photon orbiting retrograde, the photon sphere will be between 3-5 Schwarzschild radii from the center of the black hole. The exact location of the photon sphere depends on the magnitude of the black hole's rotation. For a charged, nonrotating black hole, there will only be one photon sphere, and the radius of the photon sphere will decrease for increasing black hole charge. For non-extremal, charged, rotating black holes, there will always be two photon spheres, with the exact radii depending on the parameters of the black hole. Near a rotating black hole, spacetime rotates similar to a vortex. The rotating spacetime will drag any matter and light into rotation around the spinning black hole. This effect of general relativity, called frame dragging, gets stronger closer to the spinning mass. The region of spacetime in which it is impossible to stay still is called the ergosphere. The ergosphere of a black hole is a volume bounded by the black hole's event horizon and the ergosurface, which coincides with the event horizon at the poles but bulges out from it around the equator. Matter and radiation can escape from the ergosphere. Through the Penrose process, objects can emerge from the ergosphere with more energy than they entered with. The extra energy is taken from the rotational energy of the black hole, slowing down the rotation of the black hole.: 268 A variation of the Penrose process in the presence of strong magnetic fields, the Blandford–Znajek process, is considered a likely mechanism for the enormous luminosity and relativistic jets of quasars and other active galactic nuclei. The observable region of spacetime around a black hole closest to its event horizon is called the plunging region. In this area it is no longer possible for free falling matter to follow circular orbits or stop a final descent into the black hole. Instead, it will rapidly plunge toward the black hole at close to the speed of light, growing increasingly hot and producing a characteristic, detectable thermal emission. However, light and radiation emitted from this region can still escape from the black hole's gravitational pull. For a nonspinning, uncharged black hole, the radius of the event horizon, or Schwarzschild radius, is proportional to the mass, M, through r s = 2 G M c 2 ≈ 2.95 M M ⊙ k m , {\displaystyle r_{\mathrm {s} }={\frac {2GM}{c^{2}}}\approx 2.95\,{\frac {M}{M_{\odot }}}~\mathrm {km,} } where rs is the Schwarzschild radius and M☉ is the mass of the Sun.: 124 For a black hole with nonzero spin or electric charge, the radius is smaller,[Note 1] until an extremal black hole could have an event horizon close to r + = G M c 2 , {\displaystyle r_{\mathrm {+} }={\frac {GM}{c^{2}}},} half the radius of a nonspinning, uncharged black hole of the same mass. Since the volume within the Schwarzschild radius increase with the cube of the radius, average density of a black hole inside its Schwarzschild radius is inversely proportional to the square of its mass: supermassive black holes are much less dense than stellar black holes. The average density of a 108 M☉ black hole is comparable to that of water. The defining feature of a black hole is the existence of an event horizon, a boundary in spacetime through which matter and light can pass only inward towards the center of the black hole. Nothing, not even light, can escape from inside the event horizon. The event horizon is referred to as such because if an event occurs within the boundary, information from that event cannot reach or affect an outside observer, making it impossible to determine whether such an event occurred.: 179 For non-rotating black holes, the geometry of the event horizon is precisely spherical, while for rotating black holes, the event horizon is oblate. To a distant observer, a clock near a black hole would appear to tick more slowly than one further from the black hole.: 217 This effect, known as gravitational time dilation, would also cause an object falling into a black hole to appear to slow as it approached the event horizon, never quite reaching the horizon from the perspective of an outside observer.: 218 All processes on this object would appear to slow down, and any light emitted by the object to appear redder and dimmer, an effect known as gravitational redshift. An object falling from half of a Schwarzschild radius above the event horizon would fade away until it could no longer be seen, disappearing from view within one hundredth of a second. It would also appear to flatten onto the black hole, joining all other material that had ever fallen into the hole. On the other hand, an observer falling into a black hole would not notice any of these effects as they cross the event horizon. Their own clocks appear to them to tick normally, and they cross the event horizon after a finite time without noting any singular behaviour. In general relativity, it is impossible to determine the location of the event horizon from local observations, due to Einstein's equivalence principle.: 222 Black holes that are rotating and/or charged have an inner horizon, often called the Cauchy horizon, inside of the black hole. The inner horizon is divided up into two segments: an ingoing section and an outgoing section. At the ingoing section of the Cauchy horizon, radiation and matter that fall into the black hole would build up at the horizon, causing the curvature of spacetime to go to infinity. This would cause an observer falling in to experience tidal forces. This phenomenon is often called mass inflation, since it is associated with a parameter dictating the black hole's internal mass growing exponentially, and the buildup of tidal forces is called the mass-inflation singularity or Cauchy horizon singularity. Some physicists have argued that in realistic black holes, accretion and Hawking radiation would stop mass inflation from occurring. At the outgoing section of the inner horizon, infalling radiation would backscatter off of the black hole's spacetime curvature and travel outward, building up at the outgoing Cauchy horizon. This would cause an infalling observer to experience a gravitational shock wave and tidal forces as the spacetime curvature at the horizon grew to infinity. This buildup of tidal forces is called the shock singularity. Both of these singularities are weak, meaning that an object crossing them would only be deformed a finite amount by tidal forces, even though the spacetime curvature would still be infinite at the singularity. This is as opposed to a strong singularity, where an object hitting the singularity would be stretched and squeezed by an infinite amount. They are also null singularities, meaning that a photon could travel parallel to the them without ever being intercepted. Ignoring quantum effects, every black hole has a singularity inside, points where the curvature of spacetime becomes infinite, and geodesics terminate within a finite proper time.: 205 For a non-rotating black hole, this region takes the shape of a single point; for a rotating black hole it is smeared out to form a ring singularity that lies in the plane of rotation.: 264 In both cases, the singular region has zero volume. All of the mass of the black hole ends up in the singularity.: 252 Since the singularity has nonzero mass in an infinitely small space, it can be thought of as having infinite density. Observers falling into a Schwarzschild black hole (i.e., non-rotating and not charged) cannot avoid being carried into the singularity once they cross the event horizon. As they fall further into the black hole, they will be torn apart by the growing tidal forces in a process sometimes referred to as spaghettification or the noodle effect. Eventually, they will reach the singularity and be crushed into an infinitely small point.: 182 However any perturbations, such as those caused by matter or radiation falling in, would cause space to oscillate chaotically near the singularity. Any matter falling in would experience intense tidal forces rapidly changing in direction, all while being compressed into an increasingly small volume. Alternative forms of general relativity, including addition of some quatum effects, can lead to regular, or nonsingular, black holes without singularities. For example, the fuzzball model, based on string theory, states that black holes are actually made up of quantum microstates and need not have a singularity or an event horizon. The theory of loop quantum gravity proposes that the curvature and density at the center of a black hole is large, but not infinite. Formation Black holes are formed by gravitational collapse of massive stars, either by direct collapse or during a supernova explosion in a process called fallback. Black holes can result from the merger of two neutron stars or a neutron star and a black hole. Other more speculative mechanisms include primordial black holes created from density fluctuations in the early universe, the collapse of dark stars, a hypothetical object powered by annihilation of dark matter, or from hypothetical self-interacting dark matter. Gravitational collapse occurs when an object's internal pressure is insufficient to resist the object's own gravity. At the end of a star's life, it will run out of hydrogen to fuse, and will start fusing more and more massive elements, until it gets to iron. Since the fusion of elements heavier than iron would require more energy than it would release, nuclear fusion ceases. If the iron core of the star is too massive, the star will no longer be able to support itself and will undergo gravitational collapse. While most of the energy released during gravitational collapse is emitted very quickly, an outside observer does not actually see the end of this process. Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the delay growing to infinity as the emitting material reaches the event horizon. Thus the external observer never sees the formation of the event horizon; instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away. Observations of quasars at redshift z ∼ 7 {\displaystyle z\sim 7} , less than a billion years after the Big Bang, has led to investigations of other ways to form black holes. The accretion process to build supermassive black holes has a limiting rate of mass accumulation and a billion years is not enough time to reach quasar status. One suggestion is direct collapse of nearly pure hydrogen gas (low metalicity) clouds characteristic of the young universe, forming a supermassive star which collapses into a black hole. It has been suggested that seed black holes with typical masses of ~105 M☉ could have formed in this way which then could grow to ~109 M☉. However, the very large amount of gas required for direct collapse is not typically stable to fragmentation to form multiple stars. Thus another approach suggests massive star formation followed by collisions that seed massive black holes which ultimately merge to create a quasar.: 85 A neutron star in a common envelope with a regular star can accrete sufficient material to collapse to a black hole or two neutron stars can merge. These avenues for the formation of black holes are considered relatively rare. In the current epoch of the universe, conditions needed to form black holes are rare and are mostly only found in stars. However, in the early universe, conditions may have allowed for black hole formations via other means. Fluctuations of spacetime soon after the Big Bang may have formed areas that were denser then their surroundings. Initially, these regions would not have been compact enough to form a black hole, but eventually, the curvature of spacetime in the regions become large enough to cause them to collapse into a black hole. Different models for the early universe vary widely in their predictions of the scale of these fluctuations. Various models predict the creation of primordial black holes ranging from a Planck mass (~2.2×10−8 kg) to hundreds of thousands of solar masses. Primordial black holes with masses less than 1015 g would have evaporated by now due to Hawking radiation. Despite the early universe being extremely dense, it did not re-collapse into a black hole during the Big Bang, since the universe was expanding rapidly and did not have the gravitational differential necessary for black hole formation. Models for the gravitational collapse of objects of relatively constant size, such as stars, do not necessarily apply in the same way to rapidly expanding space such as the Big Bang. In principle, black holes could be formed in high-energy particle collisions that achieve sufficient density, although no such events have been detected. These hypothetical micro black holes, which could form from the collision of cosmic rays and Earth's atmosphere or in particle accelerators like the Large Hadron Collider, would not be able to aggregate additional mass. Instead, they would evaporate in about 10−25 seconds, posing no threat to the Earth. Evolution Black holes can also merge with other objects such as stars or even other black holes. This is thought to have been important, especially in the early growth of supermassive black holes, which could have formed from the aggregation of many smaller objects. The process has also been proposed as the origin of some intermediate-mass black holes. Mergers of supermassive black holes may take a long time: As a binary of supermassive black holes approach each other, most nearby stars are ejected, leaving little for the remaining black holes to gravitationally interact with that would allow them to get closer to each other. This phenomenon has been called the final parsec problem, as the distance at which this happens is usually around one parsec. When a black hole accretes matter, the gas in the inner accretion disk orbits at very high speeds because of its proximity to the black hole. The resulting friction heats the inner disk to temperatures at which it emits vast amounts of electromagnetic radiation (mainly X-rays) detectable by telescopes. By the time the matter of the disk reaches the ISCO, between 5.7% and 42% of its mass will have been converted to energy, depending on the black hole's spin. About 90% of this energy is released within about 20 black hole radii. In many cases, accretion disks are accompanied by relativistic jets that are emitted along the black hole's poles, which carry away much of the energy. The mechanism for the creation of these jets is currently not well understood, in part due to insufficient data. Many of the universe's most energetic phenomena have been attributed to the accretion of matter on black holes. Active galactic nuclei and quasars are believed to be the accretion disks of supermassive black holes. X-ray binaries are generally accepted to be binary systems in which one of the two objects is a compact object accreting matter from its companion. Ultraluminous X-ray sources may be the accretion disks of intermediate-mass black holes. At a certain rate of accretion, the outward radiation pressure will become as strong as the inward gravitational force, and the black hole should unable to accrete any faster. This limit is called the Eddington limit. However, many black holes accrete beyond this rate due to their non-spherical geometry or instabilities in the accretion disk. Accretion beyond the limit is called Super-Eddington accretion and may have been commonplace in the early universe. Stars have been observed to get torn apart by tidal forces in the immediate vicinity of supermassive black holes in galaxy nuclei, in what is known as a tidal disruption event (TDE). Some of the material from the disrupted star forms an accretion disk around the black hole, which emits observable electromagnetic radiation. The correlation between the masses of supermassive black holes in the centres of galaxies with the velocity dispersion and mass of stars in their host bulges suggests that the formation of galaxies and the formation of their central black holes are related. Black hole winds from rapid accretion, particularly when the galaxy itself is still accreting matter, can compress gas nearby, accelerating star formation. However, if the winds become too strong, the black hole may blow nearly all of the gas out of the galaxy, quenching star formation. Black hole jets may also energize nearby cavities of plasma and eject low-entropy gas from out of the galactic core, causing gas in galactic centers to be hotter than expected. If Hawking's theory of black hole radiation is correct, then black holes are expected to shrink and evaporate over time as they lose mass by the emission of photons and other particles. The temperature of this thermal spectrum (Hawking temperature) is proportional to the surface gravity of the black hole, which is inversely proportional to the mass. Hence, large black holes emit less radiation than small black holes.: Ch. 9.6 A stellar black hole of 1 M☉ has a Hawking temperature of 62 nanokelvins. This is far less than the 2.7 K temperature of the cosmic microwave background radiation. Stellar-mass or larger black holes receive more mass from the cosmic microwave background than they emit through Hawking radiation and thus will grow instead of shrinking. To have a Hawking temperature larger than 2.7 K (and be able to evaporate), a black hole would need a mass less than the Moon. Such a black hole would have a diameter of less than a tenth of a millimetre. The Hawking radiation for an astrophysical black hole is predicted to be very weak and would thus be exceedingly difficult to detect from Earth. A possible exception is the burst of gamma rays emitted in the last stage of the evaporation of primordial black holes. Searches for such flashes have proven unsuccessful and provide stringent limits on the possibility of existence of low mass primordial black holes, with modern research predicting that primordial black holes must make up less than a fraction of 10−7 of the universe's total mass. NASA's Fermi Gamma-ray Space Telescope, launched in 2008, has searched for these flashes, but has not yet found any. The properties of a black hole are constrained and interrelated by the theories that predict these properties. When based on general relativity, these relationships are called the laws of black hole mechanics. For a black hole that is not still forming or accreting matter, the zeroth law of black hole mechanics states the black hole's surface gravity is constant across the event horizon. The first law relates changes in the black hole's surface area, angular momentum, and charge to changes in its energy. The second law says the surface area of a black hole never decreases on its own. Finally, the third law says that the surface gravity of a black hole is never zero. These laws are mathematical analogs of the laws of thermodynamics. They are not equivalent, however, because, according to general relativity without quantum mechanics, a black hole can never emit radiation, and thus its temperature must always be zero.: 11 Quantum mechanics predicts that a black hole will continuously emit thermal Hawking radiation, and therefore must always have a nonzero temperature. It also predicts that all black holes have entropy which scales with their surface area. When quantum mechanics is accounted for, the laws of black hole mechanics become equivalent to the classical laws of thermodynamics. However, these conclusions are derived without a complete theory of quantum gravity, although many potential theories do predict black holes having entropy and temperature. Thus, the true quantum nature of black hole thermodynamics continues to be debated.: 29 Observational evidence Millions of black holes with around 30 solar masses derived from stellar collapse are expected to exist in the Milky Way. Even a dwarf galaxy like Draco should have hundreds. Only a few of these have been detected. By nature, black holes do not themselves emit any electromagnetic radiation other than the hypothetical Hawking radiation, so astrophysicists searching for black holes must generally rely on indirect observations. The defining characteristic of a black hole is its event horizon. The horizon itself cannot be imaged, so all other possible explanations for these indirect observations must be considered and eliminated before concluding that a black hole has been observed.: 11 The Event Horizon Telescope (EHT) is a global system of radio telescopes capable of directly observing a black hole shadow. The angular resolution of a telescope is based on its aperture and the wavelengths it is observing. Because the angular diameters of Sagittarius A* and Messier 87* in the sky are very small, a single telescope would need to be about the size of the Earth to clearly distinguish their horizons using radio wavelengths. By combining data from several different radio telescopes around the world, the Event Horizon Telescope creates an effective aperture the diameter size of the Earth. The EHT team used imaging algorithms to compute the most probable image from the data in its observations of Sagittarius A* and M87*. Gravitational-wave interferometry can be used to detect merging black holes and other compact objects. In this method, a laser beam is split down two long arms of a tunnel. The laser beams reflect off of mirrors in the tunnels and converge at the intersection of the arms, cancelling each other out. However, when a gravitational wave passes, it warps spacetime, changing the lengths of the arms themselves. Since each laser beam is now travelling a slightly different distance, they do not cancel out and produce a recognizable signal. Analysis of the signal can give scientists information about what caused the gravitational waves. Since gravitational waves are very weak, gravitational-wave observatories such as LIGO must have arms several kilometers long and carefully control for noise from Earth to be able to detect these gravitational waves. Since the first measurements in 2016, multiple gravitational waves from black holes have been detected and analyzed. The proper motions of stars near the centre of the Milky Way provide strong observational evidence that these stars are orbiting a supermassive black hole. Since 1995, astronomers have tracked the motions of 90 stars orbiting an invisible object coincident with the radio source Sagittarius A*. In 1998, by fitting the motions of the stars to Keplerian orbits, the astronomers were able to infer that Sagittarius A* must be a 2.6×106 M☉ object must be contained within a radius of 0.02 light-years. Since then, one of the stars—called S2—has completed a full orbit. From the orbital data, astronomers were able to refine the calculations of the mass of Sagittarius A* to 4.3×106 M☉, with a radius of less than 0.002 light-years. This upper limit radius is larger than the Schwarzschild radius for the estimated mass, so the combination does not prove Sagittarius A* is a black hole. Nevertheless, these observations strongly suggest that the central object is a supermassive black hole as there are no other plausible scenarios for confining so much invisible mass into such a small volume. Additionally, there is some observational evidence that this object might possess an event horizon, a feature unique to black holes. The Event Horizon Telescope image of Sagittarius A*, released in 2022, provided further confirmation that it is indeed a black hole. X-ray binaries are binary systems that emit a majority of their radiation in the X-ray part of the electromagnetic spectrum. These X-ray emissions result when a compact object accretes matter from an ordinary star. The presence of an ordinary star in such a system provides an opportunity for studying the central object and to determine if it might be a black hole. By measuring the orbital period of the binary, the distance to the binary from Earth, and the mass of the companion star, scientists can estimate the mass of the compact object. The Tolman-Oppenheimer-Volkoff limit (TOV limit) dictates the largest mass a nonrotating neutron star can be, and is estimated to be about two solar masses. While a rotating neutron star can be slightly more massive, if the compact object is much more massive than the TOV limit, it cannot be a neutron star and is generally expected to be a black hole. The first strong candidate for a black hole, Cygnus X-1, was discovered in this way by Charles Thomas Bolton, Louise Webster, and Paul Murdin in 1972. Observations of rotation broadening of the optical star reported in 1986 lead to a compact object mass estimate of 16 solar masses, with 7 solar masses as the lower bound. In 2011, this estimate was updated to 14.1±1.0 M☉ for the black hole and 19.2±1.9 M☉ for the optical stellar companion. X-ray binaries can be categorized as either low-mass or high-mass; This classification is based on the mass of the companion star, not the compact object itself. In a class of X-ray binaries called soft X-ray transients, the companion star is of relatively low mass, allowing for more accurate estimates of the black hole mass. These systems actively emit X-rays for only several months once every 10–50 years. During the period of low X-ray emission, called quiescence, the accretion disk is extremely faint, allowing detailed observation of the companion star. Numerous black hole candidates have been measured by this method. Black holes are also sometimes found in binaries with other compact objects, such as white dwarfs, neutron stars, and other black holes. The centre of nearly every galaxy contains a supermassive black hole. The close observational correlation between the mass of this hole and the velocity dispersion of the host galaxy's bulge, known as the M–sigma relation, strongly suggests a connection between the formation of the black hole and that of the galaxy itself. Astronomers use the term active galaxy to describe galaxies with unusual characteristics, such as unusual spectral line emission and very strong radio emission. Theoretical and observational studies have shown that the high levels of activity in the centers of these galaxies, regions called active galactic nuclei (AGN), may be explained by accretion onto supermassive black holes. These AGN consist of a central black hole that may be millions or billions of times more massive than the Sun, a disk of interstellar gas and dust called an accretion disk, and two jets perpendicular to the accretion disk. Although supermassive black holes are expected to be found in most AGN, only some galaxies' nuclei have been more carefully studied in attempts to both identify and measure the actual masses of the central supermassive black hole candidates. Some of the most notable galaxies with supermassive black hole candidates include the Andromeda Galaxy, Messier 32, Messier 87, the Sombrero Galaxy, and the Milky Way itself. Another way black holes can be detected is through observation of effects caused by their strong gravitational field. One such effect is gravitational lensing: The deformation of spacetime around a massive object causes light rays to be deflected, making objects behind them appear distorted. When the lensing object is a black hole, this effect can be strong enough to create multiple images of a star or other luminous source. However, the distance between the lensed images may be too small for contemporary telescopes to resolve—this phenomenon is called microlensing. Instead of seeing two images of a lensed star, astronomers see the star brighten slightly as the black hole moves towards the line of sight between the star and Earth and then return to its normal luminosity as the black hole moves away. The turn of the millennium saw the first 3 candidate detections of black holes in this way, and in January 2022, astronomers reported the first confirmed detection of a microlensing event from an isolated black hole. This was also the first determination of an isolated black hole mass, 7.1±1.3 M☉. Alternatives While there is a strong case for supermassive black holes, the model for stellar-mass black holes assumes of an upper limit for the mass of a neutron star: objects observed to have more mass are assumed to be black holes. However, the properties of extremely dense matter are poorly understood. New exotic phases of matter could allow other kinds of massive objects. Quark stars would be made up of quark matter and supported by quark degeneracy pressure, a form of degeneracy pressure even stronger than neutron degeneracy pressure. This would halt gravitational collapse at a higher mass than for a neutron star. Even stronger stars called electroweak stars would convert quarks in their cores into leptons, providing additional pressure to stop the star from collapsing. If, as some extensions of the Standard Model posit, quarks and leptons are made up of the even-smaller fundamental particles called preons, a very compact star could be supported by preon degeneracy pressure. While none of these hypothetical models can explain all of the observations of stellar black hole candidates, a Q star is the only alternative which could significantly exceed the mass limit for neutron stars and thus provide an alternative for supermassive black holes.: 12 A few theoretical objects have been conjectured to match observations of astronomical black hole candidates identically or near-identically, but which function via a different mechanism. A dark energy star would convert infalling matter into vacuum energy; This vacuum energy would be much larger than the vacuum energy of outside space, exerting outwards pressure and preventing a singularity from forming. A black star would be gravitationally collapsing slowly enough that quantum effects would keep it just on the cusp of fully collapsing into a black hole. A gravastar would consist of a very thin shell and a dark-energy interior providing outward pressure to stop the collapse into a black hole or formation of a singularity; It could even have another gravastar inside, called a 'nestar'. Open questions According to the no-hair theorem, a black hole is defined by only three parameters: its mass, charge, and angular momentum. This seems to mean that all other information about the matter that went into forming the black hole is lost, as there is no way to determine anything about the black hole from outside other than those three parameters. When black holes were thought to persist forever, this information loss was not problematic, as the information can be thought of as existing inside the black hole. However, black holes slowly evaporate by emitting Hawking radiation. This radiation does not appear to carry any additional information about the matter that formed the black hole, meaning that this information is seemingly gone forever. This is called the black hole information paradox. Theoretical studies analyzing the paradox have led to both further paradoxes and new ideas about the intersection of quantum mechanics and general relativity. While there is no consensus on the resolution of the paradox, work on the problem is expected to be important for a theory of quantum gravity.: 126 Observations of faraway galaxies have found that ultraluminous quasars, powered by supermassive black holes, existed in the early universe as far as redshift z ≥ 7 {\displaystyle z\geq 7} . These black holes have been assumed to be the products of the gravitational collapse of large population III stars. However, these stellar remnants were not massive enough to produce the quasars observed at early times without accreting beyond the Eddington limit, the theoretical maximum rate of black hole accretion. Physicists have suggested a variety of different mechanisms by which these supermassive black holes may have formed. It has been proposed that smaller black holes may have also undergone mergers to produce the observed supermassive black holes. It is also possible that they were seeded by direct-collapse black holes, in which a large cloud of hot gas avoids fragmentation that would lead to multiple stars, due to low angular momentum or heating from a nearby galaxy. Given the right circumstances, a single supermassive star forms and collapses directly into a black hole without undergoing typical stellar evolution. Additionally, these supermassive black holes in the early universe may be high-mass primordial black holes, which could have accreted further matter in the centers of galaxies. Finally, certain mechanisms allow black holes to grow faster than the theoretical Eddington limit, such as dense gas in the accretion disk limiting outward radiation pressure that prevents the black hole from accreting. However, the formation of bipolar jets prevent super-Eddington rates. In fiction Black holes have been portrayed in science fiction in a variety of ways. Even before the advent of the term itself, objects with characteristics of black holes appeared in stories such as the 1928 novel The Skylark of Space with its "black Sun" and the "hole in space" in the 1935 short story Starship Invincible. As black holes grew to public recognition in the 1960s and 1970s, they began to be featured in films as well as novels, such as Disney's The Black Hole. Black holes have also been used in works of the 21st century, such as Christopher Nolan's science fiction epic Interstellar. Authors and screenwriters have exploited the relativistic effects of black holes, particularly gravitational time dilation. For example, Interstellar features a black hole planet with a time dilation factor of over 60,000:1, while the 1977 novel Gateway depicts a spaceship approaching but never crossing the event horizon of a black hole from the perspective of an outside observer due to time dilation effects. Black holes have also been appropriated as wormholes or other methods of faster-than-light travel, such as in the 1974 novel The Forever War, where a network of black holes is used for interstellar travel. Additionally, black holes can feature as hazards to spacefarers and planets: A black hole threatens a deep-space outpost in 1978 short story The Black Hole Passes, and a binary black hole dangerously alters the orbit of a planet in the 2018 Netflix reboot of Lost in Space. Notes References Further reading External links |
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Contents Jews Jews (Hebrew: יְהוּדִים, ISO 259-2: Yehudim, Israeli pronunciation: [jehuˈdim]), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of ancient Israel and Judah. They traditionally adhere to Judaism. Jewish ethnicity, religion, and community are highly interrelated, as Judaism is an ethnic religion, though many ethnic Jews do not practice it. Religious Jews regard converts to Judaism as members of the Jewish nation, pursuant to the long-standing conversion process. The Israelites emerged from the pre-existing Canaanite peoples to establish Israel and Judah in the Southern Levant during the Iron Age. Originally, Jews referred to the inhabitants of the kingdom of Judah and were distinguished from the gentiles and the Samaritans. According to the Hebrew Bible, these inhabitants predominately originate from the tribe of Judah, who were descendants of Judah, the fourth son of Jacob. The tribe of Benjamin were another significant demographic in Judah and were considered Jews too. By the late 6th century BCE, Judaism had evolved from the Israelite religion, dubbed Yahwism (for Yahweh) by modern scholars, having a theology that religious Jews believe to be the expression of the Mosaic covenant between God and the Jewish people. After the Babylonian exile, Jews referred to followers of Judaism, descendants of the Israelites, citizens of Judea, or allies of the Judean state. Jewish migration within the Mediterranean region during the Hellenistic period, followed by population transfers, caused by events like the Jewish–Roman wars, gave rise to the Jewish diaspora, consisting of diverse Jewish communities that maintained their sense of Jewish history, identity, and culture. In the following millennia, Jewish diaspora communities coalesced into three major ethnic subdivisions according to where their ancestors settled: the Ashkenazim (Central and Eastern Europe), the Sephardim (Iberian Peninsula), and the Mizrahim (Middle East and North Africa). While these three major divisions account for most of the world's Jews, there are other smaller Jewish groups outside of the three. Prior to World War II, the global Jewish population reached a peak of 16.7 million, representing around 0.7% of the world's population at that time. During World War II, approximately six million Jews throughout Europe were systematically murdered by Nazi Germany in a genocide known as the Holocaust. Since then, the population has slowly risen again, and as of 2021[update], was estimated to be at 15.2 million by the demographer Sergio Della Pergola or less than 0.2% of the total world population in 2012.[b] Today, over 85% of Jews live in Israel or the United States. Israel, whose population is 73.9% Jewish, is the only country where Jews comprise more than 2.5% of the population. Jews have significantly influenced and contributed to the development and growth of human progress in many fields, both historically and in modern times, including in science and technology, philosophy, ethics, literature, governance, business, art, music, comedy, theatre, cinema, architecture, food, medicine, and religion. Jews founded Christianity and had an indirect but profound influence on Islam. In these ways and others, Jews have played a significant role in the development of Western culture. Name and etymology The term "Jew" is derived from the Hebrew word יְהוּדִי Yehudi, with the plural יְהוּדִים Yehudim. Endonyms in other Jewish languages include the Ladino ג׳ודיו Djudio (plural ג׳ודיוס, Djudios) and the Yiddish ייִד Yid (plural ייִדן Yidn). Though Genesis 29:35 and 49:8 connect "Judah" with the verb yada, meaning "praise", scholars generally agree that "Judah" most likely derives from the name of a Levantine geographic region dominated by gorges and ravines. The gradual ethnonymic shift from "Israelites" to "Jews", regardless of their descent from Judah, although not contained in the Torah, is made explicit in the Book of Esther (4th century BCE) of the Tanakh. Some modern scholars disagree with the conflation, based on the works of Josephus, Philo and Apostle Paul. The English word "Jew" is a derivation of Middle English Gyw, Iewe. The latter was loaned from the Old French giu, which itself evolved from the earlier juieu, which in turn derived from judieu/iudieu which through elision had dropped the letter "d" from the Medieval Latin Iudaeus, which, like the New Testament Greek term Ioudaios, meant both "Jew" and "Judean" / "of Judea". The Greek term was a loan from Aramaic *yahūdāy, corresponding to Hebrew יְהוּדִי Yehudi. Some scholars prefer translating Ioudaios as "Judean" in the Bible since it is more precise, denotes the community's origins and prevents readers from engaging in antisemitic eisegesis. Others disagree, believing that it erases the Jewish identity of Biblical characters such as Jesus. Daniel R. Schwartz distinguishes "Judean" and "Jew". Here, "Judean" refers to the inhabitants of Judea, which encompassed southern Palestine. Meanwhile, "Jew" refers to the descendants of Israelites that adhere to Judaism. Converts are included in the definition. But Shaye J.D. Cohen argues that "Judean" is inclusive of believers of the Judean God and allies of the Judean state. Another scholar, Jodi Magness, wrote the term Ioudaioi refers to a "people of Judahite/Judean ancestry who worshipped the God of Israel as their national deity and (at least nominally) lived according to his laws." The etymological equivalent is in use in other languages, e.g., يَهُودِيّ yahūdī (sg.), al-yahūd (pl.), in Arabic, "Jude" in German, "judeu" in Portuguese, "Juif" (m.)/"Juive" (f.) in French, "jøde" in Danish and Norwegian, "judío/a" in Spanish, "jood" in Dutch, "żyd" in Polish etc., but derivations of the word "Hebrew" are also in use to describe a Jew, e.g., in Italian (Ebreo), in Persian ("Ebri/Ebrani" (Persian: عبری/عبرانی)) and Russian (Еврей, Yevrey). The German word "Jude" is pronounced [ˈjuːdə], the corresponding adjective "jüdisch" [ˈjyːdɪʃ] (Jewish) is the origin of the word "Yiddish". According to The American Heritage Dictionary of the English Language, fourth edition (2000), It is widely recognized that the attributive use of the noun Jew, in phrases such as Jew lawyer or Jew ethics, is both vulgar and highly offensive. In such contexts Jewish is the only acceptable possibility. Some people, however, have become so wary of this construction that they have extended the stigma to any use of Jew as a noun, a practice that carries risks of its own. In a sentence such as There are now several Jews on the council, which is unobjectionable, the substitution of a circumlocution like Jewish people or persons of Jewish background may in itself cause offense for seeming to imply that Jew has a negative connotation when used as a noun. Identity Judaism shares some of the characteristics of a nation, an ethnicity, a religion, and a culture, making the definition of who is a Jew vary slightly depending on whether a religious or national approach to identity is used.[better source needed] Generally, in modern secular usage, Jews include three groups: people who were born to a Jewish family regardless of whether or not they follow the religion, those who have some Jewish ancestral background or lineage (sometimes including those who do not have strictly matrilineal descent), and people without any Jewish ancestral background or lineage who have formally converted to Judaism and therefore are followers of the religion. In the context of biblical and classical literature, Jews could refer to inhabitants of the Kingdom of Judah, or the broader Judean region, allies of the Judean state, or anyone that followed Judaism. Historical definitions of Jewish identity have traditionally been based on halakhic definitions of matrilineal descent, and halakhic conversions. These definitions of who is a Jew date back to the codification of the Oral Torah into the Babylonian Talmud, around 200 CE. Interpretations by Jewish sages of sections of the Tanakh – such as Deuteronomy 7:1–5, which forbade intermarriage between their Israelite ancestors and seven non-Israelite nations: "for that [i.e. giving your daughters to their sons or taking their daughters for your sons,] would turn away your children from following me, to serve other gods"[failed verification] – are used as a warning against intermarriage between Jews and gentiles. Leviticus 24:10 says that the son in a marriage between a Hebrew woman and an Egyptian man is "of the community of Israel." This is complemented by Ezra 10:2–3, where Israelites returning from Babylon vow to put aside their gentile wives and their children. A popular theory is that the rape of Jewish women in captivity brought about the law of Jewish identity being inherited through the maternal line, although scholars challenge this theory citing the Talmudic establishment of the law from the pre-exile period. Another argument is that the rabbis changed the law of patrilineal descent to matrilineal descent due to the widespread rape of Jewish women by Roman soldiers. Since the anti-religious Haskalah movement of the late 18th and 19th centuries, halakhic interpretations of Jewish identity have been challenged. According to historian Shaye J. D. Cohen, the status of the offspring of mixed marriages was determined patrilineally in the Bible. He brings two likely explanations for the change in Mishnaic times: first, the Mishnah may have been applying the same logic to mixed marriages as it had applied to other mixtures (Kil'ayim). Thus, a mixed marriage is forbidden as is the union of a horse and a donkey, and in both unions the offspring are judged matrilineally. Second, the Tannaim may have been influenced by Roman law, which dictated that when a parent could not contract a legal marriage, offspring would follow the mother. Rabbi Rivon Krygier follows a similar reasoning, arguing that Jewish descent had formerly passed through the patrilineal descent and the law of matrilineal descent had its roots in the Roman legal system. Origins The prehistory and ethnogenesis of the Jews are closely intertwined with archaeology, biology, historical textual records, mythology, and religious literature. The ethnic origin of the Jews lie in the Israelites, a confederation of Iron Age Semitic-speaking tribes that inhabited a part of Canaan during the tribal and monarchic periods. Modern Jews are named after and also descended from the southern Israelite Kingdom of Judah. Gary A. Rendsburg links the early Canaanite nomadic pastoralists confederation to the Shasu known to the Egyptians around the 15th century BCE. According to the Hebrew Bible narrative, Jewish history begins with the Biblical patriarchs such as Abraham, his son Isaac, Isaac's son Jacob, and the Biblical matriarchs Sarah, Rebecca, Leah, and Rachel, who lived in Canaan. The twelve sons of Jacob subsequently gave birth to the Twelve Tribes. Jacob and his family migrated to Ancient Egypt after being invited to live with Jacob's son Joseph by the Pharaoh himself. Jacob's descendants were later enslaved until the Exodus, led by Moses. Afterwards, the Israelites conquered Canaan under Moses' successor Joshua, and went through the period of the Biblical judges after the death of Joshua. Through the mediation of Samuel, the Israelites were subject to a king, Saul, who was succeeded by David and then Solomon, after whom the United Monarchy ended and was split into a separate Kingdom of Israel and a Kingdom of Judah. The Kingdom of Judah is described as comprising the tribes of Judah, Benjamin and partially, Levi. They later assimilated remnants of other tribes who migrated there from the northern Kingdom of Israel. In the extra-biblical record, the Israelites become visible as a people between 1200 and 1000 BCE. There is well accepted archeological evidence referring to "Israel" in the Merneptah Stele, which dates to about 1200 BCE, and in the Mesha stele from 840 BCE. It is debated whether a period like that of the Biblical judges occurred and if there ever was a United Monarchy. There is further disagreement about the earliest existence of the Kingdoms of Israel and Judah and their extent and power. Historians agree that a Kingdom of Israel existed by c. 900 BCE,: 169–95 there is a consensus that a Kingdom of Judah existed by c. 700 BCE at least, and recent excavations in Khirbet Qeiyafa have provided strong evidence for dating the Kingdom of Judah to the 10th century BCE. In 587 BCE, Nebuchadnezzar II, King of the Neo-Babylonian Empire, besieged Jerusalem, destroyed the First Temple and deported parts of the Judahite population. Scholars disagree regarding the extent to which the Bible should be accepted as a historical source for early Israelite history. Rendsburg states that there are two approximately equal groups of scholars who debate the historicity of the biblical narrative, the minimalists who largely reject it, and the maximalists who largely accept it, with the minimalists being the more vocal of the two. Some of the leading minimalists reframe the biblical account as constituting the Israelites' inspiring national myth narrative, suggesting that according to the modern archaeological and historical account, the Israelites and their culture did not overtake the region by force, but instead branched out of the Canaanite peoples and culture through the development of a distinct monolatristic—and later monotheistic—religion of Yahwism centered on Yahweh, one of the gods of the Canaanite pantheon. The growth of Yahweh-centric belief, along with a number of cultic practices, gradually gave rise to a distinct Israelite ethnic group, setting them apart from other Canaanites. According to Dever, modern archaeologists have largely discarded the search for evidence of the biblical narrative surrounding the patriarchs and the exodus. According to the maximalist position, the modern archaeological record independently points to a narrative which largely agrees with the biblical account. This narrative provides a testimony of the Israelites as a nomadic people known to the Egyptians as belonging to the Shasu. Over time these nomads left the desert and settled on the central mountain range of the land of Canaan, in simple semi-nomadic settlements in which pig bones are notably absent. This population gradually shifted from a tribal lifestyle to a monarchy. While the archaeological record of the ninth century BCE provides evidence for two monarchies, one in the south under a dynasty founded by a figure named David with its capital in Jerusalem, and one in the north under a dynasty founded by a figure named Omri with its capital in Samaria. It also points to an early monarchic period in which these regions shared material culture and religion, suggesting a common origin. Archaeological finds also provide evidence for the later cooperation of these two kingdoms in their coalition against Aram, and for their destructions by the Assyrians and later by the Babylonians. Genetic studies on Jews show that most Jews worldwide bear a common genetic heritage which originates in the Middle East, and that they share certain genetic traits with other Gentile peoples of the Fertile Crescent. The genetic composition of different Jewish groups shows that Jews share a common gene pool dating back four millennia, as a marker of their common ancestral origin. Despite their long-term separation, Jewish communities maintained their unique commonalities, propensities, and sensibilities in culture, tradition, and language. History The earliest recorded evidence of a people by the name of Israel appears in the Merneptah Stele, which dates to around 1200 BCE. The majority of scholars agree that this text refers to the Israelites, a group that inhabited the central highlands of Canaan, where archaeological evidence shows that hundreds of small settlements were constructed between the 12th and 10th centuries BCE. The Israelites differentiated themselves from neighboring peoples through various distinct characteristics including religious practices, prohibition on intermarriage, and an emphasis on genealogy and family history. In the 10th century BCE, two neighboring Israelite kingdoms—the northern Kingdom of Israel and the southern Kingdom of Judah—emerged. Since their inception, they shared ethnic, cultural, linguistic and religious characteristics despite a complicated relationship. Israel, with its capital mostly in Samaria, was larger and wealthier, and soon developed into a regional power. In contrast, Judah, with its capital in Jerusalem, was less prosperous and covered a smaller, mostly mountainous territory. However, while in Israel the royal succession was often decided by a military coup d'état, resulting in several dynasty changes, political stability in Judah was much greater, as it was ruled by the House of David for the whole four centuries of its existence. Scholars also describe Biblical Jews as a 'proto-nation', in the modern nationalist sense, comparable to classical Greeks, the Gauls and the British Celts. Around 720 BCE, Kingdom of Israel was destroyed when it was conquered by the Neo-Assyrian Empire, which came to dominate the ancient Near East. Under the Assyrian resettlement policy, a significant portion of the northern Israelite population was exiled to Mesopotamia and replaced by immigrants from the same region. During the same period, and throughout the 7th century BCE, the Kingdom of Judah, now under Assyrian vassalage, experienced a period of prosperity and witnessed a significant population growth. This prosperity continued until the Neo-Assyrian king Sennacherib devastated the region of Judah in response to a rebellion in the area, ultimately halting at Jerusalem. Later in the same century, the Assyrians were defeated by the rising Neo-Babylonian Empire, and Judah became its vassal. In 587 BCE, following a revolt in Judah, the Babylonian king Nebuchadnezzar II besieged and destroyed Jerusalem and the First Temple, putting an end to the kingdom. The majority of Jerusalem's residents, including the kingdom's elite, were exiled to Babylon. According to the Book of Ezra, the Persian Cyrus the Great ended the Babylonian exile in 538 BCE, the year after he captured Babylon. The exile ended with the return under Zerubbabel the Prince (so called because he was a descendant of the royal line of David) and Joshua the Priest (a descendant of the line of the former High Priests of the Temple) and their construction of the Second Temple circa 521–516 BCE. As part of the Persian Empire, the former Kingdom of Judah became the province of Judah (Yehud Medinata), with a smaller territory and a reduced population. Judea was under control of the Achaemenids until the fall of their empire in c. 333 BCE to Alexander the Great. After several centuries under foreign imperial rule, the Maccabean Revolt against the Seleucid Empire resulted in an independent Hasmonean kingdom, under which the Jews once again enjoyed political independence for a period spanning from 110 to 63 BCE. Under Hasmonean rule the boundaries of their kingdom were expanded to include not only the land of the historical kingdom of Judah, but also the Galilee and Transjordan. In the beginning of this process the Idumeans, who had infiltrated southern Judea after the destruction of the First Temple, were converted en masse. In 63 BCE, Judea was conquered by the Romans. From 37 BCE to 6 CE, the Romans allowed the Jews to maintain some degree of independence by installing the Herodian dynasty as vassal kings. However, Judea eventually came directly under Roman control and was incorporated into the Roman Empire as the province of Judaea. The Jewish–Roman wars, a series of failed uprisings against Roman rule during the first and second centuries CE, had profound and devastating consequences for the Jewish population of Judaea. The First Jewish–Roman War (66–73/74 CE) culminated in the destruction of Jerusalem and the Second Temple, after which the significantly diminished Jewish population was stripped of political autonomy. A few generations later, the Bar Kokhba revolt (132–136 CE) erupted in response to Roman plans to rebuild Jerusalem as a Roman colony, and, possibly, to restrictions on circumcision. Its violent suppression by the Romans led to the near-total depopulation of Judea, and the demographic and cultural center of Jewish life shifted to Galilee. Jews were subsequently banned from residing in Jerusalem and the surrounding area, and the province of Judaea was renamed Syria Palaestina. These developments effectively ended Jewish efforts to restore political sovereignty in the region for nearly two millennia. Similar upheavals impacted the Jewish communities in the empire's eastern provinces during the Diaspora Revolt (115–117 CE), leading to the near-total destruction of Jewish diaspora communities in Libya, Cyprus and Egypt, including the highly influential community in Alexandria. The destruction of the Second Temple in 70 CE brought profound changes to Judaism. With the Temple's central place in Jewish worship gone, religious practices shifted towards prayer, Torah study (including Oral Torah), and communal gatherings in synagogues. Judaism also lost much of its sectarian nature.: 69 Two of the three main sects that flourished during the late Second Temple period, namely the Sadducees and Essenes, eventually disappeared, while Pharisaic beliefs became the foundational, liturgical, and ritualistic basis of Rabbinic Judaism, which emerged as the prevailing form of Judaism since late antiquity. The Jewish diaspora existed well before the destruction of the Second Temple in 70 CE and had been ongoing for centuries, with the dispersal driven by both forced expulsions and voluntary migrations. In Mesopotamia, a testimony to the beginnings of the Jewish community can be found in Joachin's ration tablets, listing provisions allotted to the exiled Judean king and his family by Nebuchadnezzar II, and further evidence are the Al-Yahudu tablets, dated to the 6th–5th centuries BCE and related to the exiles from Judea arriving after the destruction of the First Temple, though there is ample evidence for the presence of Jews in Babylonia even from 626 BCE. In Egypt, the documents from Elephantine reveal the trials of a community founded by a Persian Jewish garrison at two fortresses on the frontier during the 5th–4th centuries BCE, and according to Josephus the Jewish community in Alexandria existed since the founding of the city in the 4th century BCE by Alexander the Great. By 200 BCE, there were well established Jewish communities both in Egypt and Mesopotamia ("Babylonia" in Jewish sources) and in the two centuries that followed, Jewish populations were also present in Asia Minor, Greece, Macedonia, Cyrene, and, beginning in the middle of the first century BCE, in the city of Rome. Later, in the first centuries CE, as a result of the Jewish-Roman Wars, a large number of Jews were taken as captives, sold into slavery, or compelled to flee from the regions affected by the wars, contributing to the formation and expansion of Jewish communities across the Roman Empire as well as in Arabia and Mesopotamia. After the Bar Kokhba revolt, the Jewish population in Judaea—now significantly reduced— made efforts to recover from the revolt's devastating effects, but never fully regained its former strength. Between the second and fourth centuries CE, the region of Galilee emerged as the primary center of Jewish life in Syria Palaestina, experiencing both demographic growth and cultural development. It was during this period that two central rabbinic texts, the Mishnah and the Jerusalem Talmud, were composed. The Romans recognized the patriarchs—rabbinic sages such as Judah ha-Nasi—as representatives of the Jewish people, granting them a certain degree of autonomy. However, as the Roman Empire gave way to the Christianized Byzantine Empire under Constantine, Jews began to face persecution by both the Church and imperial authorities, Jews came to be persecuted by the church and the authorities, and many immigrated to communities in the diaspora. By the fourth century CE, Jews are believed to have lost their demographic majority in Syria Palaestina. The long-established Jewish community of Mesopotamia, which had been living under Parthian and later Sasanian rule, beyond the confines of the Roman Empire, became an important center of Jewish study as Judea's Jewish population declined. Estimates often place the Babylonian Jewish community of the 3rd to 7th centuries at around one million, making it the largest Jewish diaspora community of that period. Under the political leadership of the exilarch, who was regarded as a royal heir of the House of David, this community had an autonomous status and served as a place of refuge for the Jews of Syria Palaestina. A number of significant Talmudic academies, such as the Nehardea, Pumbedita, and Sura academies, were established in Mesopotamia, and many important Amoraim were active there. The Babylonian Talmud, a centerpiece of Jewish religious law, was compiled in Babylonia in the 3rd to 6th centuries. Jewish diaspora communities are generally described to have coalesced into three major ethnic subdivisions according to where their ancestors settled: the Ashkenazim (initially in the Rhineland and France), the Sephardim (initially in the Iberian Peninsula), and the Mizrahim (Middle East and North Africa). Romaniote Jews, Tunisian Jews, Yemenite Jews, Egyptian Jews, Ethiopian Jews, Bukharan Jews, Mountain Jews, and other groups also predated the arrival of the Sephardic diaspora. During the same period, Jewish communities in the Middle East thrived under Islamic rule, especially in cities like Baghdad, Cairo, and Damascus. In Babylonia, from the 7th to 11th centuries the Pumbedita and Sura academies led the Arab and to an extent the entire Jewish world. The deans and students of said academies defined the Geonic period in Jewish history. Following this period were the Rishonim who lived from the 11th to 15th centuries. Like their European counterparts, Jews in the Middle East and North Africa also faced periods of persecution and discriminatory policies, with the Almohad Caliphate in North Africa and Iberia issuing forced conversion decrees, causing Jews such as Maimonides to seek safety in other regions. Despite experiencing repeated waves of persecution, Ashkenazi Jews in Western Europe worked in a variety of fields, making an impact on their communities' economy and societies. In Francia, for example, figures like Isaac Judaeus and Armentarius occupied prominent social and economic positions. Francia also witnessed the development of a sophisticated tradition of biblical commentary, as exemplified by Rashi and the tosafists. In 1144, the first documented blood libel occurred in Norwich, England, marking an escalation in the pattern of discrimination and violence that Jews had already been subjected to throughout medieval Europe. During the 12th and 13th centuries, Jews faced frequent antisemitic legislation - including laws prescribing distinctive dress - alongside segregation, repeated blood libels, pogroms, and massacres such as the Rhineland Massacres (1066). The Jews of the Holy Roman Empire were designated Servi camerae regis (“servants of the imperial chamber”) by Frederick II, a status that afforded limited protection while simultaneously entangling them in the political struggles between the emperor and the German principalities and cities. Persecution intensified during the Black Death in the mid-14th century, when Jews were accused of poisoning wells and many communities were destroyed. These pressures, combined with major expulsions such as that from England in 1290, gradually pushed Ashkenazi Jewish populations eastward into Poland, Lithuania, and Russia. One of the largest Jewish communities of the Middle Ages was in the Iberian Peninsula, which for a time contained the largest Jewish population in Europe. Iberian Jewry endured discrimination under the Visigoths but saw its fortunes improve under Umayyad rule and later the Taifa kingdoms. During this period, the Jews of Muslim Spain entered a "Golden Age" marked by achievements in Hebrew poetry and literature, religious scholarship, grammar, medicine and science, with leading figures including Hasdai ibn Shaprut, Judah Halevi, Moses ibn Ezra and Solomon ibn Gabirol. Jews also rose to high office, most notably Samuel ibn Naghrillah, a scholar and poet who served as grand vizier and military commander of Granada. The Golden Age ended with the rise of the radical Almoravid and Almohad dynasties, whose persecutions drove many Jews from Iberia (including Maimonides), together with the advancing Reconquista. In 1391, widespread pogroms swept across Spain, leaving thousands dead and forcing mass conversions. The Spanish Inquisition was later established to pursue, torture and execute conversos who continued to practice Judaism in secret, while public disputations were staged to discredit Judaism. In 1492, after the Reconquista, Isabella I of Castile and Ferdinand II of Aragon decreed the expulsion of all Jews who refused conversion, sending an estimated 200,000 into exile in Portugal, Italy, North Africa, and the Ottoman Empire. In 1497, Portugal's Jews, about 30,000, were formally ordered expelled but instead were forcibly converted to retain their economic role. In 1498, some 3,500 Jews were expelled from Navarre. Many converts outwardly adopted Christianity while secretly preserving Jewish practices, becoming crypto-Jews (also known as marranos or anusim), who remained targets of the various Inquisitions for centuries. Following the expulsions from Spain and Portugal in the 1490s, Jewish exiles dispersed across the Mediterranean, Europe, and North Africa. Many settled in the Ottoman Empire—which, replacing the Iberian Peninsula, became home to the world's largest Jewish population—where new communities developed in Anatolia, the Balkans, and the Land of Israel. Cities such as Istanbul and Thessaloniki grew into major Jewish centers, while in 16th-century Safed a flourishing spiritual life took shape. There, Solomon Alkabetz, Moses Cordovero, and Isaac Luria developed influential new schools of Kabbalah, giving powerful impetus to Jewish mysticism, and Joseph Karo composed the Shulchan Aruch, which became a cornerstone of Jewish law. In the 17th century, Portuguese conversos who returned to Judaism and engaged in trade and banking helped establish Amsterdam as a prosperous Jewish center, while also forming communities in cities such as Antwerp and London. This period also witnessed waves of messianic fervor, most notably the rise of the Sabbatean movement in the 1660s, led by Sabbatai Zvi of İzmir, which reverberated throughout the Jewish world. In Eastern Europe, Poland–Lithuania became the principal center of Ashkenazi Jewry, eventually becoming home to the largest Jewish population in the world. Jewish life flourished there from in the early modern era, supported by relative stability, economic opportunity, and strong communal institutions. The mid-17th century brought devastation with the Cossack uprisings in Ukraine, which reversed migration flows and sent refugees westward, yet Poland–Lithuania remained the demographic and cultural heartland of Ashkenazic Jewry. Following the partitions of Poland, most of its Jews came under Russian rule and were confined to the "Pale of Settlement." The 18th century also witnessed new religious and intellectual currents. Hasidism, founded by Baal Shem Tov, emphasized mysticism and piety, while its opponents, the Misnagdim ("opponents") led by the Vilna Gaon, defended rabbinic scholarship and tradition. In Western Europe, during the 1760s and 1770s, the Haskalah (Jewish Enlightenment) emerged in German-speaking lands, where figures such as Moses Mendelssohn promoted secular learning, vernacular literacy, and integration into European society. Elsewhere, Jews began to be re-admitted to Western Europe, including England, where Menasseh ben Israel petitioned Oliver Cromwell for their return. In the Americas, Jews of Sephardic descent first arrived as conversos in Spanish and Portuguese colonies, where many faced trial by Inquisition tribunals for "judaizing." A more durable presence began in Dutch Brazil, where Jews openly practiced their religion and established the first synagogues in the New World, before the Portuguese reconquest forced their dispersal to Amsterdam, the Caribbean, and North America. Sephardic communities took root in Curaçao, Suriname, Jamaica, and Barbados, later joined by Ashkenazi migrants. In North America, Jews were present from the mid-17th century, with New Amsterdam hosting the first organized congregation in 1654. By the time of the American Revolution, small communities in New York, Newport, Philadelphia, Savannah, and Charleston played an active role in the struggle for independence. In the late 19th century, Jews in Western Europe gradually achieved legal emancipation, though social acceptance remained limited by persistent antisemitism and rising nationalism. In Eastern Europe, particularly within the Russian Empire's Pale of Settlement, Jews faced mounting legal restrictions and recurring pogroms. From this environment emerged Zionism, a national revival movement originating in Central and Eastern Europe that sought to re-establish a Jewish polity in the Land of Israel as a means of returning the Jewish people to their ancestral homeland and ending centuries of exile and persecution. This led to waves of Jewish migration to Ottoman-controlled Palestine. Theodor Herzl, who is considered the father of political Zionism, offered his vision of a future Jewish state in his 1896 book Der Judenstaat (The Jewish State); a year later, he presided over the First Zionist Congress. The antisemitism that inflicted Jewish communities in Europe also triggered a mass exodus of 2.8 million Jews to the United States between 1881 and 1924. Despite this, some Jews of Europe and the United States were able to make great achievements in various fields of science and culture. Among the most influential from this period are Albert Einstein in physics, Sigmund Freud in psychology, Franz Kafka in literature, and Irving Berlin in music. Many Nobel Prize winners at this time were Jewish, as is still the case. When Adolf Hitler and the Nazi Party came to power in Germany in 1933, the situation for Jews deteriorated rapidly as a direct result of Nazi policies. Many Jews fled from Europe to Mandatory Palestine, the United States, and the Soviet Union as a result of racial anti-Semitic laws, economic difficulties, and the fear of an impending war. World War II started in 1939, and by 1941, Hitler occupied almost all of Europe. Following the German invasion of the Soviet Union in 1941, the Final Solution—an extensive, organized effort with an unprecedented scope intended to annihilate the Jewish people—began, and resulted in the persecution and murder of Jews in Europe and North Africa. In Poland, three million were murdered in gas chambers in all concentration camps combined, with one million at the Auschwitz camp complex alone. The Holocaust is the name given to this genocide, in which six million Jews in total were systematically murdered. Before and during the Holocaust, enormous numbers of Jews immigrated to Mandatory Palestine. In 1944, the Jewish insurgency in Mandatory Palestine began with the aim of gaining full independence from the United Kingdom. On 14 May 1948, upon the termination of the mandate, David Ben-Gurion declared the creation of the State of Israel, a Jewish and democratic state. Immediately afterwards, all neighboring Arab states invaded, and were resisted by the newly formed Israel Defense Forces. In 1949, the war ended and Israel started building its state and absorbing waves of Aliyah, granting citizenship to Jews all over the world via the Law of Return passed in 1950. However, both the Israeli–Palestinian conflict and wider Arab–Israeli conflict continue to this day. Culture The Jewish people and the religion of Judaism are strongly interrelated. Converts to Judaism have a status within the Jewish people equal to those born into it. However, converts who go on to practice no Judaism are likely to be viewed with skepticism. Mainstream Judaism does not proselytize, and conversion is considered a difficult task. A significant portion of conversions are undertaken by children of mixed marriages, or would-be or current spouses of Jews. The Hebrew Bible, a religious interpretation of the traditions and early history of the Jews, established the first of the Abrahamic religions, which are now practiced by 54 percent of the world. Judaism guides its adherents in both practice and belief, and has been called not only a religion, but also a "way of life," which has made drawing a clear distinction between Judaism, Jewish culture, and Jewish identity rather difficult. Throughout history, in eras and places as diverse as the ancient Hellenic world, in Europe before and after The Age of Enlightenment (see Haskalah), in Islamic Spain and Portugal, in North Africa and the Middle East, India, China, or the contemporary United States and Israel, cultural phenomena have developed that are in some sense characteristically Jewish without being at all specifically religious. Some factors in this come from within Judaism, others from the interaction of Jews or specific communities of Jews with their surroundings, and still others from the inner social and cultural dynamics of the community, as opposed to from the religion itself. This phenomenon has led to considerably different Jewish cultures unique to their own communities. Hebrew is the liturgical language of Judaism (termed lashon ha-kodesh, "the holy tongue"), the language in which most of the Hebrew scriptures (Tanakh) were composed, and the daily speech of the Jewish people for centuries. By the 5th century BCE, Aramaic, a closely related tongue, joined Hebrew as the spoken language in Judea. By the 3rd century BCE, some Jews of the diaspora were speaking Greek. Others, such as in the Jewish communities of Asoristan, known to Jews as Babylonia, were speaking Hebrew and Aramaic, the languages of the Babylonian Talmud. Dialects of these same languages were also used by the Jews of Syria Palaestina at that time.[citation needed] For centuries, Jews worldwide have spoken the local or dominant languages of the regions they migrated to, often developing distinctive dialectal forms or branches that became independent languages. Yiddish is the Judaeo-German language developed by Ashkenazi Jews who migrated to Central Europe. Ladino is the Judaeo-Spanish language developed by Sephardic Jews who migrated to the Iberian Peninsula. Due to many factors, including the impact of the Holocaust on European Jewry, the Jewish exodus from Arab and Muslim countries, and widespread emigration from other Jewish communities around the world, ancient and distinct Jewish languages of several communities, including Judaeo-Georgian, Judaeo-Arabic, Judaeo-Berber, Krymchak, Judaeo-Malayalam and many others, have largely fallen out of use. For over sixteen centuries Hebrew was used almost exclusively as a liturgical language, and as the language in which most books had been written on Judaism, with a few speaking only Hebrew on the Sabbath. Hebrew was revived as a spoken language by Eliezer ben Yehuda, who arrived in Palestine in 1881. It had not been used as a mother tongue since Tannaic times. Modern Hebrew is designated as the "State language" of Israel. Despite efforts to revive Hebrew as the national language of the Jewish people, knowledge of the language is not commonly possessed by Jews worldwide and English has emerged as the lingua franca of the Jewish diaspora. Although many Jews once had sufficient knowledge of Hebrew to study the classic literature, and Jewish languages like Yiddish and Ladino were commonly used as recently as the early 20th century, most Jews lack such knowledge today and English has by and large superseded most Jewish vernaculars. The three most commonly spoken languages among Jews today are Hebrew, English, and Russian. Some Romance languages, particularly French and Spanish, are also widely used. Yiddish has been spoken by more Jews in history than any other language, but it is far less used today following the Holocaust and the adoption of Modern Hebrew by the Zionist movement and the State of Israel. In some places, the mother language of the Jewish community differs from that of the general population or the dominant group. For example, in Quebec, the Ashkenazic majority has adopted English, while the Sephardic minority uses French as its primary language. Similarly, South African Jews adopted English rather than Afrikaans. Due to both Czarist and Soviet policies, Russian has superseded Yiddish as the language of Russian Jews, but these policies have also affected neighboring communities. Today, Russian is the first language for many Jewish communities in a number of Post-Soviet states, such as Ukraine and Uzbekistan,[better source needed] as well as for Ashkenazic Jews in Azerbaijan, Georgia, and Tajikistan. Although communities in North Africa today are small and dwindling, Jews there had shifted from a multilingual group to a monolingual one (or nearly so), speaking French in Algeria, Morocco, and the city of Tunis, while most North Africans continue to use Arabic or Berber as their mother tongue.[citation needed] There is no single governing body for the Jewish community, nor a single authority with responsibility for religious doctrine. Instead, a variety of secular and religious institutions at the local, national, and international levels lead various parts of the Jewish community on a variety of issues. Today, many countries have a Chief Rabbi who serves as a representative of that country's Jewry. Although many Hasidic Jews follow a certain hereditary Hasidic dynasty, there is no one commonly accepted leader of all Hasidic Jews. Many Jews believe that the Messiah will act a unifying leader for Jews and the entire world. A number of modern scholars of nationalism support the existence of Jewish national identity in antiquity. One of them is David Goodblatt, who generally believes in the existence of nationalism before the modern period. In his view, the Bible, the parabiblical literature and the Jewish national history provide the base for a Jewish collective identity. Although many of the ancient Jews were illiterate (as were their neighbors), their national narrative was reinforced through public readings. The Hebrew language also constructed and preserved national identity. Although it was not widely spoken after the 5th century BCE, Goodblatt states: the mere presence of the language in spoken or written form could invoke the concept of a Jewish national identity. Even if one knew no Hebrew or was illiterate, one could recognize that a group of signs was in Hebrew script. ... It was the language of the Israelite ancestors, the national literature, and the national religion. As such it was inseparable from the national identity. Indeed its mere presence in visual or aural medium could invoke that identity. Anthony D. Smith, an historical sociologist considered one of the founders of the field of nationalism studies, wrote that the Jews of the late Second Temple period provide "a closer approximation to the ideal type of the nation [...] than perhaps anywhere else in the ancient world." He adds that this observation "must make us wary of pronouncing too readily against the possibility of the nation, and even a form of religious nationalism, before the onset of modernity." Agreeing with Smith, Goodblatt suggests omitting the qualifier "religious" from Smith's definition of ancient Jewish nationalism, noting that, according to Smith, a religious component in national memories and culture is common even in the modern era. This view is echoed by political scientist Tom Garvin, who writes that "something strangely like modern nationalism is documented for many peoples in medieval times and in classical times as well," citing the ancient Jews as one of several "obvious examples", alongside the classical Greeks and the Gaulish and British Celts. Fergus Millar suggests that the sources of Jewish national identity and their early nationalist movements in the first and second centuries CE included several key elements: the Bible as both a national history and legal source, the Hebrew language as a national language, a system of law, and social institutions such as schools, synagogues, and Sabbath worship. Adrian Hastings argued that Jews are the "true proto-nation", that through the model of ancient Israel found in the Hebrew Bible, provided the world with the original concept of nationhood which later influenced Christian nations. However, following Jerusalem's destruction in the first century CE, Jews ceased to be a political entity and did not resemble a traditional nation-state for almost two millennia. Despite this, they maintained their national identity through collective memory, religion and sacred texts, even without land or political power, and remained a nation rather than just an ethnic group, eventually leading to the rise of Zionism and the establishment of Israel. Steven Weitzman suggests that Jewish nationalist sentiment in antiquity was encouraged because under foreign rule (Persians, Greeks, Romans) Jews were able to claim that they were an ancient nation. This claim was based on the preservation and reverence of their scriptures, the Hebrew language, the Temple and priesthood, and other traditions of their ancestors. Doron Mendels further observes that the Hasmonean kingdom, one of the few examples of indigenous statehood at its time, significantly reinforced Jewish national consciousness. The memory of this period of independence contributed to the persistent efforts to revive Jewish sovereignty in Judea, leading to the major revolts against Roman rule in the 1st and 2nd centuries CE. Demographics Within the world's Jewish population there are distinct ethnic divisions, most of which are primarily the result of geographic branching from an originating Israelite population, and subsequent independent evolutions. An array of Jewish communities was established by Jewish settlers in various places around the Old World, often at great distances from one another, resulting in effective and often long-term isolation. During the millennia of the Jewish diaspora the communities would develop under the influence of their local environments: political, cultural, natural, and populational. Today, manifestations of these differences among the Jews can be observed in Jewish cultural expressions of each community, including Jewish linguistic diversity, culinary preferences, liturgical practices, religious interpretations, as well as degrees and sources of genetic admixture. Jews are often identified as belonging to one of two major groups: the Ashkenazim and the Sephardim. Ashkenazim are so named in reference to their geographical origins (their ancestors' culture coalesced in the Rhineland, an area historically referred to by Jews as Ashkenaz). Similarly, Sephardim (Sefarad meaning "Spain" in Hebrew) are named in reference their origins in Iberia. The diverse groups of Jews of the Middle East and North Africa are often collectively referred to as Sephardim together with Sephardim proper for liturgical reasons having to do with their prayer rites. A common term for many of these non-Spanish Jews who are sometimes still broadly grouped as Sephardim is Mizrahim (lit. 'easterners' in Hebrew). Nevertheless, Mizrahis and Sepharadim are usually ethnically distinct. Smaller groups include, but are not restricted to, Indian Jews such as the Bene Israel, Bnei Menashe, Cochin Jews, and Bene Ephraim; the Romaniotes of Greece; the Italian Jews ("Italkim" or "Bené Roma"); the Teimanim from Yemen; various African Jews, including most numerously the Beta Israel of Ethiopia; and Chinese Jews, most notably the Kaifeng Jews, as well as various other distinct but now almost extinct communities. The divisions between all these groups are approximate and their boundaries are not always clear. The Mizrahim for example, are a heterogeneous collection of North African, Central Asian, Caucasian, and Middle Eastern Jewish communities that are no closer related to each other than they are to any of the earlier mentioned Jewish groups. In modern usage, however, the Mizrahim are sometimes termed Sephardi due to similar styles of liturgy, despite independent development from Sephardim proper. Thus, among Mizrahim there are Egyptian Jews, Iraqi Jews, Lebanese Jews, Kurdish Jews, Moroccan Jews, Libyan Jews, Syrian Jews, Bukharian Jews, Mountain Jews, Georgian Jews, Iranian Jews, Afghan Jews, and various others. The Teimanim from Yemen are sometimes included, although their style of liturgy is unique and they differ in respect to the admixture found among them to that found in Mizrahim. In addition, there is a differentiation made between Sephardi migrants who established themselves in the Middle East and North Africa after the expulsion of the Jews from Spain and Portugal in the 1490s and the pre-existing Jewish communities in those regions. Ashkenazi Jews represent the bulk of modern Jewry, with at least 70 percent of Jews worldwide (and up to 90 percent prior to World War II and the Holocaust). As a result of their emigration from Europe, Ashkenazim also represent the overwhelming majority of Jews in the New World continents, in countries such as the United States, Canada, Argentina, Australia, and Brazil. In France, the immigration of Jews from Algeria (Sephardim) has led them to outnumber the Ashkenazim. Only in Israel is the Jewish population representative of all groups, a melting pot independent of each group's proportion within the overall world Jewish population. Y DNA studies tend to imply a small number of founders in an old population whose members parted and followed different migration paths. In most Jewish populations, these male line ancestors appear to have been mainly Middle Eastern. For example, Ashkenazi Jews share more common paternal lineages with other Jewish and Middle Eastern groups than with non-Jewish populations in areas where Jews lived in Eastern Europe, Germany, and the French Rhine Valley. This is consistent with Jewish traditions in placing most Jewish paternal origins in the region of the Middle East. Conversely, the maternal lineages of Jewish populations, studied by looking at mitochondrial DNA, are generally more heterogeneous. Scholars such as Harry Ostrer and Raphael Falk believe this indicates that many Jewish males found new mates from European and other communities in the places where they migrated in the diaspora after fleeing ancient Israel. In contrast, Behar has found evidence that about 40 percent of Ashkenazi Jews originate maternally from just four female founders, who were of Middle Eastern origin. The populations of Sephardi and Mizrahi Jewish communities "showed no evidence for a narrow founder effect." Subsequent studies carried out by Feder et al. confirmed the large portion of non-local maternal origin among Ashkenazi Jews. Reflecting on their findings related to the maternal origin of Ashkenazi Jews, the authors conclude "Clearly, the differences between Jews and non-Jews are far larger than those observed among the Jewish communities. Hence, differences between the Jewish communities can be overlooked when non-Jews are included in the comparisons." However, a 2025 genetic study on the Ashkenazi Jewish founder population supports the presence of a substantial Near Eastern component in the maternal lineages. Analyses of mitochondrial DNA (mtDNA) indicate that the core founder lineages, estimated at around 54, likely originated from the Near East, with these founder signatures appearing in multiple copies across the population. While later admixture introduced additional mtDNA lineages, these absorbed lineages are distinguishable from the original founders. The findings are consistent with genome-wide Identity-by-Descent and Lineage Extinction analyses, reinforcing the Near Eastern origin of the Ashkenazi maternal founders. A study showed that 7% of Ashkenazi Jews have the haplogroup G2c, which is mainly found in Pashtuns and on lower scales all major Jewish groups, Palestinians, Syrians, and Lebanese. Studies of autosomal DNA, which look at the entire DNA mixture, have become increasingly important as the technology develops. They show that Jewish populations have tended to form relatively closely related groups in independent communities, with most in a community sharing significant ancestry in common. For Jewish populations of the diaspora, the genetic composition of Ashkenazi, Sephardic, and Mizrahi Jewish populations show a predominant amount of shared Middle Eastern ancestry. According to Behar, the most parsimonious explanation for this shared Middle Eastern ancestry is that it is "consistent with the historical formulation of the Jewish people as descending from ancient Hebrew and Israelite residents of the Levant" and "the dispersion of the people of ancient Israel throughout the Old World". North African, Italian and others of Iberian origin show variable frequencies of admixture with non-Jewish historical host populations among the maternal lines. In the case of Ashkenazi and Sephardi Jews (in particular Moroccan Jews), who are closely related, the source of non-Jewish admixture is mainly Southern European, while Mizrahi Jews show evidence of admixture with other Middle Eastern populations. Behar et al. have remarked on a close relationship between Ashkenazi Jews and modern Italians. A 2001 study found that Jews were more closely related to groups of the Fertile Crescent (Kurds, Turks, and Armenians) than to their Arab neighbors, whose genetic signature was found in geographic patterns reflective of Islamic conquests. The studies also show that Sephardic Bnei Anusim (descendants of the "anusim" who were forced to convert to Catholicism), which comprise up to 19.8 percent of the population of today's Iberia (Spain and Portugal) and at least 10 percent of the population of Ibero-America (Hispanic America and Brazil), have Sephardic Jewish ancestry within the last few centuries. The Bene Israel and Cochin Jews of India, Beta Israel of Ethiopia, and a portion of the Lemba people of Southern Africa, despite more closely resembling the local populations of their native countries, have also been thought to have some more remote ancient Jewish ancestry. Views on the Lemba have changed and genetic Y-DNA analyses in the 2000s have established a partially Middle-Eastern origin for a portion of the male Lemba population but have been unable to narrow this down further. Although historically, Jews have been found all over the world, in the decades since World War II and the establishment of Israel, they have increasingly concentrated in a small number of countries. In 2021, Israel and the United States together accounted for over 85 percent of the global Jewish population, with approximately 45.3% and 39.6% of the world's Jews, respectively. More than half (51.2%) of world Jewry resides in just ten metropolitan areas. As of 2021, these ten areas were Tel Aviv, New York, Jerusalem, Haifa, Los Angeles, Miami, Philadelphia, Paris, Washington, and Chicago. The Tel Aviv metro area has the highest percent of Jews among the total population (94.8%), followed by Jerusalem (72.3%), Haifa (73.1%), and Beersheba (60.4%), the balance mostly being Israeli Arabs. Outside Israel, the highest percent of Jews in a metropolitan area was in New York (10.8%), followed by Miami (8.7%), Philadelphia (6.8%), San Francisco (5.1%), Washington (4.7%), Los Angeles (4.7%), Toronto (4.5%), and Baltimore (4.1%). As of 2010, there were nearly 14 million Jews around the world, roughly 0.2% of the world's population at the time. According to the 2007 estimates of The Jewish People Policy Planning Institute, the world's Jewish population is 13.2 million. This statistic incorporates both practicing Jews affiliated with synagogues and the Jewish community, and approximately 4.5 million unaffiliated and secular Jews.[citation needed] According to Sergio Della Pergola, a demographer of the Jewish population, in 2021 there were about 6.8 million Jews in Israel, 6 million in the United States, and 2.3 million in the rest of the world. Israel, the Jewish nation-state, is the only country in which Jews make up a majority of the citizens. Israel was established as an independent democratic and Jewish state on 14 May 1948. Of the 120 members in its parliament, the Knesset, as of 2016[update], 14 members of the Knesset are Arab citizens of Israel (not including the Druze), most representing Arab political parties. One of Israel's Supreme Court judges is also an Arab citizen of Israel. Between 1948 and 1958, the Jewish population rose from 800,000 to two million. Currently, Jews account for 75.4 percent of the Israeli population, or 6 million people. The early years of the State of Israel were marked by the mass immigration of Holocaust survivors in the aftermath of the Holocaust and Jews fleeing Arab lands. Israel also has a large population of Ethiopian Jews, many of whom were airlifted to Israel in the late 1980s and early 1990s. Between 1974 and 1979 nearly 227,258 immigrants arrived in Israel, about half being from the Soviet Union. This period also saw an increase in immigration to Israel from Western Europe, Latin America, and North America. A trickle of immigrants from other communities has also arrived, including Indian Jews and others, as well as some descendants of Ashkenazi Holocaust survivors who had settled in countries such as the United States, Argentina, Australia, Chile, and South Africa. Some Jews have emigrated from Israel elsewhere, because of economic problems or disillusionment with political conditions and the continuing Arab–Israeli conflict. Jewish Israeli emigrants are known as yordim. The waves of immigration to the United States and elsewhere at the turn of the 19th century, the founding of Zionism and later events, including pogroms in Imperial Russia (mostly within the Pale of Settlement in present-day Ukraine, Moldova, Belarus and eastern Poland), the massacre of European Jewry during the Holocaust, and the founding of the state of Israel, with the subsequent Jewish exodus from Arab lands, all resulted in substantial shifts in the population centers of world Jewry by the end of the 20th century. More than half of the Jews live in the Diaspora (see Population table). Currently, the largest Jewish community outside Israel, and either the largest or second-largest Jewish community in the world, is located in the United States, with 6 million to 7.5 million Jews by various estimates. Elsewhere in the Americas, there are also large Jewish populations in Canada (315,000), Argentina (180,000–300,000), and Brazil (196,000–600,000), and smaller populations in Mexico, Uruguay, Venezuela, Chile, Colombia and several other countries (see History of the Jews in Latin America). According to a 2010 Pew Research Center study, about 470,000 people of Jewish heritage live in Latin America and the Caribbean. Demographers disagree on whether the United States has a larger Jewish population than Israel, with many maintaining that Israel surpassed the United States in Jewish population during the 2000s, while others maintain that the United States still has the largest Jewish population in the world. Currently, a major national Jewish population survey is planned to ascertain whether or not Israel has overtaken the United States in Jewish population. Western Europe's largest Jewish community, and the third-largest Jewish community in the world, can be found in France, home to between 483,000 and 500,000 Jews, the majority of whom are immigrants or refugees from North African countries such as Algeria, Morocco, and Tunisia (or their descendants). The United Kingdom has a Jewish community of 292,000. In Eastern Europe, the exact figures are difficult to establish. The number of Jews in Russia varies widely according to whether a source uses census data (which requires a person to choose a single nationality among choices that include "Russian" and "Jewish") or eligibility for immigration to Israel (which requires that a person have one or more Jewish grandparents). According to the latter criteria, the heads of the Russian Jewish community assert that up to 1.5 million Russians are eligible for aliyah. In Germany, the 102,000 Jews registered with the Jewish community are a slowly declining population, despite the immigration of tens of thousands of Jews from the former Soviet Union since the fall of the Berlin Wall. Thousands of Israelis also live in Germany, either permanently or temporarily, for economic reasons. Prior to 1948, approximately 800,000 Jews were living in lands which now make up the Arab world (excluding Israel). Of these, just under two-thirds lived in the French-controlled Maghreb region, 15 to 20 percent in the Kingdom of Iraq, approximately 10 percent in the Kingdom of Egypt and approximately 7 percent in the Kingdom of Yemen. A further 200,000 lived in Pahlavi Iran and the Republic of Turkey. Today, around 26,000 Jews live in Muslim-majority countries, mainly in Turkey (14,200) and Iran (9,100), while Morocco (2,000), Tunisia (1,000), and the United Arab Emirates (500) host the largest communities in the Arab world. A small-scale exodus had begun in many countries in the early decades of the 20th century, although the only substantial aliyah came from Yemen and Syria. The exodus from Arab and Muslim countries took place primarily from 1948. The first large-scale exoduses took place in the late 1940s and early 1950s, primarily in Iraq, Yemen and Libya, with up to 90 percent of these communities leaving within a few years. The peak of the exodus from Egypt occurred in 1956. The exodus in the Maghreb countries peaked in the 1960s. Lebanon was the only Arab country to see a temporary increase in its Jewish population during this period, due to an influx of refugees from other Arab countries, although by the mid-1970s the Jewish community of Lebanon had also dwindled. In the aftermath of the exodus wave from Arab states, an additional migration of Iranian Jews peaked in the 1980s when around 80 percent of Iranian Jews left the country.[citation needed] Outside Europe, the Americas, the Middle East, and the rest of Asia, there are significant Jewish populations in Australia (112,500) and South Africa (70,000). There is also a 6,800-strong community in New Zealand. Since at least the time of the Ancient Greeks, a proportion of Jews have assimilated into the wider non-Jewish society around them, by either choice or force, ceasing to practice Judaism and losing their Jewish identity. Assimilation took place in all areas, and during all time periods, with some Jewish communities, for example the Kaifeng Jews of China, disappearing entirely. The advent of the Jewish Enlightenment of the 18th century (see Haskalah) and the subsequent emancipation of the Jewish populations of Europe and America in the 19th century, accelerated the situation, encouraging Jews to increasingly participate in, and become part of, secular society. The result has been a growing trend of assimilation, as Jews marry non-Jewish spouses and stop participating in the Jewish community. Rates of interreligious marriage vary widely: In the United States, it is just under 50 percent; in the United Kingdom, around 53 percent; in France, around 30 percent; and in Australia and Mexico, as low as 10 percent. In the United States, only about a third of children from intermarriages affiliate with Jewish religious practice. The result is that most countries in the Diaspora have steady or slightly declining religiously Jewish populations as Jews continue to assimilate into the countries in which they live.[citation needed] The Jewish people and Judaism have experienced various persecutions throughout their history. During Late Antiquity and the Early Middle Ages, the Roman Empire (in its later phases known as the Byzantine Empire) repeatedly repressed the Jewish population, first by ejecting them from their homelands during the pagan Roman era and later by officially establishing them as second-class citizens during the Christian Roman era. According to James Carroll, "Jews accounted for 10% of the total population of the Roman Empire. By that ratio, if other factors had not intervened, there would be 200 million Jews in the world today, instead of something like 13 million." Later in medieval Western Europe, further persecutions of Jews by Christians occurred, notably during the Crusades—when Jews all over Germany were massacred—and in a series of expulsions from the Kingdom of England, Germany, and France. Then there occurred the largest expulsion of all, when Spain and Portugal, after the Reconquista (the Catholic Reconquest of the Iberian Peninsula), expelled both unbaptized Sephardic Jews and the ruling Muslim Moors. In the Papal States, which existed until 1870, Jews were required to live only in specified neighborhoods called ghettos. Islam and Judaism have a complex relationship. Traditionally Jews and Christians living in Muslim lands, known as dhimmis, were allowed to practice their religions and administer their internal affairs, but they were subject to certain conditions. They had to pay the jizya (a per capita tax imposed on free adult non-Muslim males) to the Islamic state. Dhimmis had an inferior status under Islamic rule. They had several social and legal disabilities such as prohibitions against bearing arms or giving testimony in courts in cases involving Muslims. Many of the disabilities were highly symbolic. The one described by Bernard Lewis as "most degrading" was the requirement of distinctive clothing, not found in the Quran or hadith but invented in early medieval Baghdad; its enforcement was highly erratic. On the other hand, Jews rarely faced martyrdom or exile, or forced compulsion to change their religion, and they were mostly free in their choice of residence and profession. Notable exceptions include the massacre of Jews and forcible conversion of some Jews by the rulers of the Almohad dynasty in Al-Andalus in the 12th century, as well as in Islamic Persia, and the forced confinement of Moroccan Jews to walled quarters known as mellahs beginning from the 15th century and especially in the early 19th century. In modern times, it has become commonplace for standard antisemitic themes to be conflated with anti-Zionist publications and pronouncements of Islamic movements such as Hezbollah and Hamas, in the pronouncements of various agencies of the Islamic Republic of Iran, and even in the newspapers and other publications of Turkish Refah Partisi."[better source needed] Throughout history, many rulers, empires and nations have oppressed their Jewish populations or sought to eliminate them entirely. Methods employed ranged from expulsion to outright genocide; within nations, often the threat of these extreme methods was sufficient to silence dissent. The history of antisemitism includes the First Crusade which resulted in the massacre of Jews; the Spanish Inquisition (led by Tomás de Torquemada) and the Portuguese Inquisition, with their persecution and autos-da-fé against the New Christians and Marrano Jews; the Bohdan Chmielnicki Cossack massacres in Ukraine; the Pogroms backed by the Russian Tsars; as well as expulsions from Spain, Portugal, England, France, Germany, and other countries in which the Jews had settled. According to a 2008 study published in the American Journal of Human Genetics, 19.8 percent of the modern Iberian population has Sephardic Jewish ancestry, indicating that the number of conversos may have been much higher than originally thought. The persecution reached a peak in Nazi Germany's Final Solution, which led to the Holocaust and the slaughter of approximately 6 million Jews. Of the world's 16 million Jews in 1939, almost 40% were murdered in the Holocaust. The Holocaust—the state-led systematic persecution and genocide of European Jews (and certain communities of North African Jews in European controlled North Africa) and other minority groups of Europe during World War II by Germany and its collaborators—remains the most notable modern-day persecution of Jews. The persecution and genocide were accomplished in stages. Legislation to remove the Jews from civil society was enacted years before the outbreak of World War II. Concentration camps were established in which inmates were used as slave labour until they died of exhaustion or disease. Where the Third Reich conquered new territory in Eastern Europe, specialized units called Einsatzgruppen murdered Jews and political opponents in mass shootings. Jews and Roma were crammed into ghettos before being transported hundreds of kilometres by freight train to extermination camps where, if they survived the journey, the majority of them were murdered in gas chambers. Virtually every arm of Germany's bureaucracy was involved in the logistics of the mass murder, turning the country into what one Holocaust scholar has called "a genocidal nation." Throughout Jewish history, Jews have repeatedly been directly or indirectly expelled from both their original homeland, the Land of Israel, and many of the areas in which they have settled. This experience as refugees has shaped Jewish identity and religious practice in many ways, and is thus a major element of Jewish history. In summary, the pogroms in Eastern Europe, the rise of modern antisemitism, the Holocaust, as well as the rise of Arab nationalism, all served to fuel the movements and migrations of huge segments of Jewry from land to land and continent to continent until they arrived back in large numbers at their original historical homeland in Israel. In the Bible, the patriarch Abraham is described as a migrant to the land of Canaan from Ur of the Chaldees. His descendants, the Children of Israel, undertook the Exodus (meaning "departure" or "exit" in Greek) from ancient Egypt, as described in the Book of Exodus. The first movement documented in the historical record occurred with the resettlement policy of the Neo-Assyrian Empire, which mandated the deportation of conquered peoples, and it is estimated some 4,500,000 among its captive populations suffered this dislocation over three centuries of Assyrian rule. With regard to Israel, Tiglath-Pileser III claims he deported 80% of the population of Lower Galilee, some 13,520 people. Some 27,000 Israelites, 20 to 25% of the population of the Kingdom of Israel, were described as being deported by Sargon II, and were replaced by other deported populations and sent into permanent exile by Assyria, initially to the Upper Mesopotamian provinces of the Assyrian Empire. Between 10,000 and 80,000 people from the Kingdom of Judah were similarly exiled by Babylonia, but these people were then returned to Judea by Cyrus the Great of the Persian Achaemenid Empire. Many Jews were exiled again by the Roman Empire. The 2,000 year dispersion of the Jewish diaspora beginning under the Roman Empire, as Jews were spread throughout the Roman world and, driven from land to land, settled wherever they could live freely enough to practice their religion. Over the course of the diaspora the center of Jewish life moved from Babylonia to the Iberian Peninsula to Poland to the United States and, as a result of Zionism, back to Israel. There were also many expulsions of Jews during the Middle Ages and Enlightenment in Europe, including: 1290, 16,000 Jews were expelled from England, (see the Statute of Jewry); in 1396, 100,000 from France; in 1421, thousands were expelled from Austria. Many of these Jews settled in East-Central Europe, especially Poland. Following the Spanish Inquisition in 1492, the Spanish population of around 200,000 Sephardic Jews were expelled by the Spanish crown and Catholic church, followed by expulsions in 1493 in Sicily (37,000 Jews) and Portugal in 1496. The expelled Jews fled mainly to the Ottoman Empire, the Netherlands, and North Africa, others migrating to Southern Europe and the Middle East. During the 19th century, France's policies of equal citizenship regardless of religion led to the immigration of Jews (especially from Eastern and Central Europe). This contributed to the arrival of millions of Jews in the New World. Over two million Eastern European Jews arrived in the United States from 1880 to 1925. In the latest phase of migrations, the Islamic Revolution of Iran caused many Iranian Jews to flee Iran. Most found refuge in the US (particularly Los Angeles, California, and Long Island, New York) and Israel. Smaller communities of Persian Jews exist in Canada and Western Europe. Similarly, when the Soviet Union collapsed, many of the Jews in the affected territory (who had been refuseniks) were suddenly allowed to leave. This produced a wave of migration to Israel in the early 1990s. Israel is the only country with a Jewish population that is consistently growing through natural population growth, although the Jewish populations of other countries, in Europe and North America, have recently increased through immigration. In the Diaspora, in almost every country the Jewish population in general is either declining or steady, but Orthodox and Haredi Jewish communities, whose members often shun birth control for religious reasons, have experienced rapid population growth. Orthodox and Conservative Judaism discourage proselytism to non-Jews, but many Jewish groups have tried to reach out to the assimilated Jewish communities of the Diaspora in order for them to reconnect to their Jewish roots. Additionally, while in principle Reform Judaism favours seeking new members for the faith, this position has not translated into active proselytism, instead taking the form of an effort to reach out to non-Jewish spouses of intermarried couples. There is also a trend of Orthodox movements reaching out to secular Jews in order to give them a stronger Jewish identity so there is less chance of intermarriage. As a result of the efforts by these and other Jewish groups over the past 25 years, there has been a trend (known as the Baal teshuva movement) for secular Jews to become more religiously observant, though the demographic implications of the trend are unknown. Additionally, there is also a growing rate of conversion to Jews by Choice of gentiles who make the decision to head in the direction of becoming Jews. Contributions Jewish individuals have played a significant role in the development and growth of Western culture, advancing many fields of thought, science and technology, both historically and in modern times, including through discrete trends in Jewish philosophy, Jewish ethics and Jewish literature, as well as specific trends in Jewish culture, including in Jewish art, Jewish music, Jewish humor, Jewish theatre, Jewish cuisine and Jewish medicine. Jews have established various Jewish political movements, religious movements, and, through the authorship of the Hebrew Bible and parts of the New Testament, provided the foundation for Christianity and Islam. More than 20 percent of the awarded Nobel Prize have gone to individuals of Jewish descent. Philanthropic giving is a widespread core function among Jewish organizations. Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Data_transfer] | [TOKENS: 1897] |
Contents Data communication Data communication is the transfer of data over a point-to-point or point-to-multipoint communication channel. Data communication comprises data transmission and data reception and can be classified as analog transmission and digital communications. Analog data communication conveys voice, data, image, signal or video information using a continuous signal, which varies in amplitude, phase, or some other property. In baseband analog transmission, messages are represented by a sequence of pulses by means of a line code; in passband analog transmission, they are communicated by a limited set of continuously varying waveforms, using a digital modulation method. Passband modulation and demodulation is carried out by modem equipment. Digital transmission and digital reception are the transfer of either a digitized analog signal or a born-digital bitstream. Baseband digital transmission is regarded as comprising part of a digital signal, whereas passband transmission of digital data may also or alternatively be considered a form of digital-to-analog conversion. Data communication channels include copper wires, optical fibers, wireless communication using radio spectrum, storage media and computer buses. The data are represented as an electromagnetic signal, such as an electrical voltage, radiowave, microwave, or infrared signal. Distinction between related subjects Digital transmission or data transmission traditionally belongs to telecommunications and electrical engineering. Basic principles of data transmission may also be covered within the computer science or computer engineering topic of data communications, which also includes computer networking applications and communication protocols, for example, routing, switching and inter-process communication. Although the Transmission Control Protocol (TCP) involves transmission, TCP and other transport layer protocols are covered in computer networking but not discussed in a textbook or course about data transmission. In most textbooks, the term analog transmission only refers to the transmission of an analog message signal (without digitization) by means of an analog signal, either as a non-modulated baseband signal or as a passband signal using an analog modulation method such as AM or FM. It may also include analog-over-analog pulse modulated baseband signals such as pulse-width modulation. In a few books within the computer networking tradition, analog transmission also refers to passband transmission of bit-streams using digital modulation methods such as FSK, PSK and ASK. The theoretical aspects of data transmission are covered by information theory and coding theory. Protocol layers and sub-topics Courses and textbooks in the field of data transmission typically deal with the following OSI model protocol layers and topics: It is also common to deal with the cross-layer design of those three layers. Applications and history Data (mainly but not exclusively informational) has been sent via non-electronic (e.g. optical, acoustic, mechanical) means since the advent of communication. Analog signal data has been sent electronically since the advent of the telephone. However, the first data electromagnetic transmission applications in modern time were electrical telegraphy (1809) and teletypewriters (1906), which are both digital signals. The fundamental theoretical work in data transmission and information theory by Harry Nyquist, Ralph Hartley, Claude Shannon and others during the early 20th century, was done with these applications in mind. In the early 1960s, Paul Baran invented distributed adaptive message block switching for digital communication of voice messages using switches that were low-cost electronics. Donald Davies invented and implemented modern data communication during 1965–7, including packet switching, high-speed routers, communication protocols, hierarchical computer networks and the essence of the end-to-end principle. Baran's work did not include routers with software switches and communication protocols, nor the idea that users, rather than the network itself, would provide the reliability. Both were seminal contributions that influenced the development of computer networks. Data transmission is utilized in computers in computer buses and for communication with peripheral equipment via parallel ports and serial ports such as RS-232 (1969), FireWire (1995) and USB (1996). The principles of data transmission are also utilized in storage media for error detection and correction since 1951. The first practical method to overcome the problem of receiving data accurately by the receiver using digital code was the Barker code invented by Ronald Hugh Barker in 1952 and published in 1953. Data transmission is utilized in computer networking equipment such as modems (1940), local area network (LAN) adapters (1964), repeaters, repeater hubs, microwave links, wireless network access points (1997), etc. In telephone networks, digital communication is utilized for transferring many phone calls over the same copper cable or fiber cable by means of pulse-code modulation (PCM) in combination with time-division multiplexing (TDM) (1962). Telephone exchanges have become digital and software controlled, facilitating many value-added services. For example, the first AXE telephone exchange was presented in 1976. Digital communication to the end user using Integrated Services Digital Network (ISDN) services became available in the late 1980s. Since the end of the 1990s, broadband access techniques such as ADSL, Cable modems, fiber-to-the-building (FTTB) and fiber-to-the-home (FTTH) have become widespread to small offices and homes. The current tendency is to replace traditional telecommunication services with packet mode communication such as IP telephony and IPTV. Transmitting analog signals digitally allows for greater signal processing capability. The ability to process a communications signal means that errors caused by random processes can be detected and corrected. Digital signals can also be sampled instead of continuously monitored. The multiplexing of multiple digital signals is much simpler compared to the multiplexing of analog signals. Because of all these advantages, because of the vast demand to transmit computer data and the ability of digital communications to do so and because recent advances in wideband communication channels and solid-state electronics have allowed engineers to realize these advantages fully, digital communications have grown quickly. The digital revolution has also resulted in many digital telecommunication applications where the principles of data transmission are applied. Examples include second-generation (1991) and later cellular telephony, video conferencing, digital TV (1998), digital radio (1999), and telemetry. Data transmission, digital transmission or digital communications is the transfer of data over a point-to-point or point-to-multipoint communication channel. Examples of such channels include copper wires, optical fibers, wireless communication channels, storage media and computer buses. The data are represented as an electromagnetic signal, such as an electrical voltage, radio wave, microwave, or infrared light. While analog transmission is the transfer of a continuously varying analog signal over an analog channel, digital communication is the transfer of discrete messages over a digital or an analog channel. The messages are either represented by a sequence of pulses by means of a line code (baseband transmission) or by a limited set of continuously varying waveforms (passband transmission), using a digital modulation method. The passband modulation and corresponding demodulation (also known as detection) are carried out by modem equipment. According to the most common definition of a digital signal, both baseband and passband signals representing bit-streams are considered as digital transmission, while an alternative definition only considers the baseband signal as digital, and passband transmission of digital data as a form of digital-to-analog conversion.[citation needed] Data transmitted may be digital messages originating from a data source, for example, a computer or a keyboard. It may also be an analog signal, such as a phone call or a video signal, digitized into a bit-stream, for example,e using pulse-code modulation (PCM) or more advanced source coding (analog-to-digital conversion and data compression) schemes. This source coding and decoding is carried out by codec equipment. Serial and parallel transmission In telecommunications, serial transmission is the sequential transmission of signal elements of a group representing a character or other entity of data. Digital serial transmissions are bits sent over a single wire, frequency or optical path sequentially. Because it requires less signal processing and fewer chances for error than parallel transmission, the transfer rate of each individual path may be faster. This can be used over longer distances, and a check digit or parity bit can be sent along with the data easily. Parallel transmission is the simultaneous transmission of related signal elements over two or more separate paths. Multiple electrical wires are used that can transmit multiple bits simultaneously, which allows for higher data transfer rates than can be achieved with serial transmission. This method is typically used internally within the computer, for example, the internal buses, and sometimes externally for such things as printers. Timing skew can be a significant issue in these systems because the wires in parallel data transmission unavoidably have slightly different properties, so some bits may arrive before others, which may corrupt the message. This issue tends to worsen with distance, making parallel data transmission less reliable for long distances. Communication channels Some communication channel types include: Asynchronous and synchronous data transmission Asynchronous serial communication uses start and stop bits to signify the beginning and end of transmission. This method of transmission is used when data is sent intermittently as opposed to in a solid stream. Synchronous transmission synchronizes transmission speeds at both the receiving and sending end of the transmission using clock signals. The clock may be a separate signal or embedded in the data. A continual stream of data is then sent between the two nodes. Due to there being no start and stop bits, the data transfer rate may be more efficient. See also References |
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[SOURCE: https://en.wikipedia.org/wiki/Middle_East#cite_ref-74] | [TOKENS: 6152] |
Contents Middle East The Middle East[b] is a geopolitical region encompassing the Arabian Peninsula, Egypt, Iran, Iraq, the Levant, and Turkey. The term came into widespread usage by Western European nations in the early 20th century as a replacement of the term Near East (both were in contrast to the Far East). The term "Middle East" has led to some confusion over its changing definitions. Since the late 20th century, it has been criticized as being too Eurocentric. The region includes the vast majority of the territories included in the closely associated definition of West Asia, but without the South Caucasus. It also includes all of Egypt (not just the Sinai region) and all of Turkey (including East Thrace). Most Middle Eastern countries (13 out of 18) are part of the Arab world. The three most populous countries in the region are Egypt, Iran, and Turkey, while Saudi Arabia is the largest Middle Eastern country by area. The history of the Middle East dates back to ancient times, and it was long considered the "cradle of civilization". The geopolitical importance of the region has been recognized and competed for during millennia. The Abrahamic religions (Judaism, Christianity, and Islam) have their origins in the Middle East. Arabs constitute the main ethnic group in the region, followed by Turks, Persians, Kurds, Jews, and Assyrians. The Middle East generally has a hot, arid climate, especially in the Arabian and Egyptian regions. Several major rivers provide irrigation to support agriculture in limited areas here, such as the Nile Delta in Egypt, the Tigris and Euphrates watersheds of Mesopotamia, and the basin of the Jordan River that spans most of the Levant. These regions are collectively known as the Fertile Crescent, and comprise the core of what historians had long referred to as the cradle of civilization; multiple regions of the world have since been classified as also having developed independent, original civilizations. Conversely, the Levantine coast and most of Turkey have relatively temperate climates typical of the Mediterranean, with dry summers and cool, wet winters. Most of the countries that border the Persian Gulf have vast reserves of petroleum. Monarchs of the Arabian Peninsula in particular have benefitted economically from petroleum exports. Because of the arid climate and dependence on the fossil fuel industry, the Middle East is both a major contributor to climate change and a region that is expected to be severely adversely affected by it. Other concepts of the region exist, including the broader Middle East and North Africa (MENA), which includes states of the Maghreb and the Sudan. The term the "Greater Middle East" also includes Afghanistan, Mauritania, Pakistan, as well as parts of East Africa, and sometimes Central Asia and the South Caucasus. Terminology The term "Middle East" may have originated in the 1850s in the British India Office. However, it became more widely known when United States naval strategist Alfred Thayer Mahan used the term in 1902 to "designate the area between Arabia and India". During this time the British and Russian empires were vying for influence in Central Asia, a rivalry that would become known as the Great Game. Mahan realized not only the strategic importance of the region, but also of its center, the Persian Gulf. He labeled the area surrounding the Persian Gulf as the Middle East. He said that, beyond Egypt's Suez Canal, the Gulf was the most important passage for Britain to control in order to keep the Russians from advancing towards British India. Mahan first used the term in his article "The Persian Gulf and International Relations", published in September 1902 in the National Review, a British journal. The Middle East, if I may adopt a term which I have not seen, will some day need its Malta, as well as its Gibraltar; it does not follow that either will be in the Persian Gulf. Naval force has the quality of mobility which carries with it the privilege of temporary absences; but it needs to find on every scene of operation established bases of refit, of supply, and in case of disaster, of security. The British Navy should have the facility to concentrate in force if occasion arise, about Aden, India, and the Persian Gulf. Mahan's article was reprinted in The Times and followed in October by a 20-article series entitled "The Middle Eastern Question", written by Sir Ignatius Valentine Chirol. During this series, Sir Ignatius expanded the definition of Middle East to include "those regions of Asia which extend to the borders of India or command the approaches to India." After the series ended in 1903, The Times removed quotation marks from subsequent uses of the term. Until World War II, it was customary to refer to areas centered on Turkey and the eastern shore of the Mediterranean as the "Near East", while the "Far East" centered on China, India and Japan. The Middle East was then defined as the area from Mesopotamia to Burma; namely, the area between the Near East and the Far East. This area broadly corresponds to South Asia. In the late 1930s, the British established the Middle East Command, which was based in Cairo, for its military forces in the region. After that time, the term "Middle East" gained broader usage in Europe and the United States. Following World War II, for example, the Middle East Institute was founded in Washington, D.C. in 1946. The corresponding adjective is Middle Eastern and the derived noun is Middle Easterner. While non-Eurocentric terms such as "Southwest Asia" or "Swasia" have been sparsely used, the classification of the African country, Egypt, among those counted in the Middle East challenges the usefulness of using such terms. The description Middle has also led to some confusion over changing definitions. Before the First World War, "Near East" was used in English to refer to the Balkans and the Ottoman Empire, while "Middle East" referred to the Caucasus, Persia, and Arabian lands, and sometimes Afghanistan, India and others. In contrast, "Far East" referred to the countries of East Asia (e.g. China, Japan, and Korea). With the collapse of the Ottoman Empire in 1918, "Near East" largely fell out of common use in English, while "Middle East" came to be applied to the emerging independent countries of the Islamic world. However, the usage "Near East" was retained by a variety of academic disciplines, including archaeology and ancient history. In their usage, the term describes an area identical to the term Middle East, which is not used by these disciplines (see ancient Near East).[citation needed] The first official use of the term "Middle East" by the United States government was in the 1957 Eisenhower Doctrine, which pertained to the Suez Crisis. Secretary of State John Foster Dulles defined the Middle East as "the area lying between and including Libya on the west and Pakistan on the east, Syria and Iraq on the North and the Arabian peninsula to the south, plus the Sudan and Ethiopia." In 1958, the State Department explained that the terms "Near East" and "Middle East" were interchangeable, and defined the region as including only Egypt, Syria, Israel, Lebanon, Jordan, Iraq, Saudi Arabia, Kuwait, Bahrain, and Qatar. Since the late 20th century, scholars and journalists from the region, such as journalist Louay Khraish and historian Hassan Hanafi have criticized the use of "Middle East" as a Eurocentric and colonialist term. The Associated Press Stylebook of 2004 says that Near East formerly referred to the farther west countries while Middle East referred to the eastern ones, but that now they are synonymous. It instructs: Use Middle East unless Near East is used by a source in a story. Mideast is also acceptable, but Middle East is preferred. European languages have adopted terms similar to Near East and Middle East. Since these are based on a relative description, the meanings depend on the country and are generally different from the English terms. In German the term Naher Osten (Near East) is still in common use (nowadays the term Mittlerer Osten is more and more common in press texts translated from English sources, albeit having a distinct meaning). In the four Slavic languages, Russian Ближний Восток or Blizhniy Vostok, Bulgarian Близкия Изток, Polish Bliski Wschód or Croatian Bliski istok (terms meaning Near East are the only appropriate ones for the region). However, some European languages do have "Middle East" equivalents, such as French Moyen-Orient, Swedish Mellanöstern, Spanish Oriente Medio or Medio Oriente, Greek is Μέση Ανατολή (Mesi Anatoli), and Italian Medio Oriente.[c] Perhaps because of the political influence of the United States and Europe, and the prominence of Western press, the Arabic equivalent of Middle East (Arabic: الشرق الأوسط ash-Sharq al-Awsaṭ) has become standard usage in the mainstream Arabic press. It comprises the same meaning as the term "Middle East" in North American and Western European usage. The designation, Mashriq, also from the Arabic root for East, also denotes a variously defined region around the Levant, the eastern part of the Arabic-speaking world (as opposed to the Maghreb, the western part). Even though the term originated in the West, countries of the Middle East that use languages other than Arabic also use that term in translation. For instance, the Persian equivalent for Middle East is خاورمیانه (Khāvar-e miyāneh), the Hebrew is המזרח התיכון (hamizrach hatikhon), and the Turkish is Orta Doğu. Countries and territory Traditionally included within the Middle East are Arabia, Asia Minor, East Thrace, Egypt, Iran, the Levant, Mesopotamia, and the Socotra Archipelago. The region includes 17 UN-recognized countries and one British Overseas Territory. Various concepts are often paralleled to the Middle East, most notably the Near East, Fertile Crescent, and Levant. These are geographical concepts, which refer to large sections of the modern-day Middle East, with the Near East being the closest to the Middle East in its geographical meaning. Due to it primarily being Arabic speaking, the Maghreb region of North Africa is sometimes included. "Greater Middle East" is a political term coined by the second Bush administration in the first decade of the 21st century to denote various countries, pertaining to the Muslim world, specifically Afghanistan, Iran, Pakistan, and Turkey. Various Central Asian countries are sometimes also included. History The Middle East lies at the juncture of Africa and Eurasia and of the Indian Ocean and the Mediterranean Sea (see also: Indo-Mediterranean). It is the birthplace and spiritual center of religions such as Christianity, Islam, Judaism, Manichaeism, Yezidi, Druze, Yarsan, and Mandeanism, and in Iran, Mithraism, Zoroastrianism, Manicheanism, and the Baháʼí Faith. Throughout its history the Middle East has been a major center of world affairs; a strategically, economically, politically, culturally, and religiously sensitive area. The region is one of the regions where agriculture was independently discovered, and from the Middle East it was spread, during the Neolithic, to different regions of the world such as Europe, the Indus Valley and Eastern Africa. Prior to the formation of civilizations, advanced cultures formed all over the Middle East during the Stone Age. The search for agricultural lands by agriculturalists, and pastoral lands by herdsmen meant different migrations took place within the region and shaped its ethnic and demographic makeup. The Middle East is widely and most famously known as the cradle of civilization. The world's earliest civilizations, Mesopotamia (Sumer, Akkad, Assyria and Babylonia), ancient Egypt and Kish in the Levant, all originated in the Fertile Crescent and Nile Valley regions of the ancient Near East. These were followed by the Hittite, Greek, Hurrian and Urartian civilisations of Asia Minor; Elam, Persia and Median civilizations in Iran, as well as the civilizations of the Levant (such as Ebla, Mari, Nagar, Ugarit, Canaan, Aramea, Mitanni, Phoenicia and Israel) and the Arabian Peninsula (Magan, Sheba, Ubar). The Near East was first largely unified under the Neo Assyrian Empire, then the Achaemenid Empire followed later by the Macedonian Empire and after this to some degree by the Iranian empires (namely the Parthian and Sassanid Empires), the Roman Empire and Byzantine Empire. The region served as the intellectual and economic center of the Roman Empire and played an exceptionally important role due to its periphery on the Sassanid Empire. Thus, the Romans stationed up to five or six of their legions in the region for the sole purpose of defending it from Sassanid and Bedouin raids and invasions. From the 4th century CE onwards, the Middle East became the center of the two main powers at the time, the Byzantine Empire and the Sassanid Empire. However, it would be the later Islamic Caliphates of the Middle Ages, or Islamic Golden Age which began with the Islamic conquest of the region in the 7th century AD, that would first unify the entire Middle East as a distinct region and create the dominant Islamic Arab ethnic identity that largely (but not exclusively) persists today. The 4 caliphates that dominated the Middle East for more than 600 years were the Rashidun Caliphate, the Umayyad caliphate, the Abbasid caliphate and the Fatimid caliphate. Additionally, the Mongols would come to dominate the region, the Kingdom of Armenia would incorporate parts of the region to their domain, the Seljuks would rule the region and spread Turko-Persian culture, and the Franks would found the Crusader states that would stand for roughly two centuries. Josiah Russell estimates the population of what he calls "Islamic territory" as roughly 12.5 million in 1000 – Anatolia 8 million, Syria 2 million, and Egypt 1.5 million. From the 16th century onward, the Middle East came to be dominated, once again, by two main powers: the Ottoman Empire and the Safavid dynasty. The modern Middle East began after World War I, when the Ottoman Empire, which was allied with the Central Powers, was defeated by the Allies and partitioned into a number of separate nations, initially under British and French Mandates. Other defining events in this transformation included the establishment of Israel in 1948 and the eventual departure of European powers, notably Britain and France by the end of the 1960s. They were supplanted in some part by the rising influence of the United States from the 1970s onwards. In the 20th century, the region's significant stocks of crude oil gave it new strategic and economic importance. Mass production of oil began around 1945, with Saudi Arabia, Iran, Kuwait, Iraq, and the United Arab Emirates having large quantities of oil. Estimated oil reserves, especially in Saudi Arabia and Iran, are some of the highest in the world, and the international oil cartel OPEC is dominated by Middle Eastern countries. During the Cold War, the Middle East was a theater of ideological struggle between the two superpowers and their allies: NATO and the United States on one side, and the Soviet Union and Warsaw Pact on the other, as they competed to influence regional allies. Besides the political reasons there was also the "ideological conflict" between the two systems. Moreover, as Louise Fawcett argues, among many important areas of contention, or perhaps more accurately of anxiety, were, first, the desires of the superpowers to gain strategic advantage in the region, second, the fact that the region contained some two-thirds of the world's oil reserves in a context where oil was becoming increasingly vital to the economy of the Western world [...] Within this contextual framework, the United States sought to divert the Arab world from Soviet influence. Throughout the 20th and 21st centuries, the region has experienced both periods of relative peace and tolerance and periods of conflict particularly between Sunnis and Shiites. Geography In 2018, the MENA region emitted 3.2 billion tonnes of carbon dioxide and produced 8.7% of global greenhouse gas emissions (GHG) despite making up only 6% of the global population. These emissions are mostly from the energy sector, an integral component of many Middle Eastern and North African economies due to the extensive oil and natural gas reserves that are found within the region. The Middle East region is one of the most vulnerable to climate change. The impacts include increase in drought conditions, aridity, heatwaves and sea level rise. Sharp global temperature and sea level changes, shifting precipitation patterns and increased frequency of extreme weather events are some of the main impacts of climate change as identified by the Intergovernmental Panel on Climate Change (IPCC). The MENA region is especially vulnerable to such impacts due to its arid and semi-arid environment, facing climatic challenges such as low rainfall, high temperatures and dry soil. The climatic conditions that foster such challenges for MENA are projected by the IPCC to worsen throughout the 21st century. If greenhouse gas emissions are not significantly reduced, part of the MENA region risks becoming uninhabitable before the year 2100. Climate change is expected to put significant strain on already scarce water and agricultural resources within the MENA region, threatening the national security and political stability of all included countries. Over 60 percent of the region's population lives in high and very high water-stressed areas compared to the global average of 35 percent. This has prompted some MENA countries to engage with the issue of climate change on an international level through environmental accords such as the Paris Agreement. Law and policy are also being established on a national level amongst MENA countries, with a focus on the development of renewable energies. Economy Middle Eastern economies range from being very poor (such as Gaza and Yemen) to extremely wealthy nations (such as Qatar and UAE). According to the International Monetary Fund, the three largest Middle Eastern economies in nominal GDP in 2023 were Saudi Arabia ($1.06 trillion), Turkey ($1.03 trillion), and Israel ($0.54 trillion). For nominal GDP per person, the highest ranking countries are Qatar ($83,891), Israel ($55,535), the United Arab Emirates ($49,451) and Cyprus ($33,807). Turkey ($3.6 trillion), Saudi Arabia ($2.3 trillion), and Iran ($1.7 trillion) had the largest economies in terms of GDP PPP. For GDP PPP per person, the highest-ranking countries are Qatar ($124,834), the United Arab Emirates ($88,221), Saudi Arabia ($64,836), Bahrain ($60,596) and Israel ($54,997). The lowest-ranking country in the Middle East, in terms of GDP nominal per capita, is Yemen ($573). The economic structure of Middle Eastern nations are different because while some are heavily dependent on export of only oil and oil-related products (Saudi Arabia, the UAE and Kuwait), others have a highly diverse economic base (such as Cyprus, Israel, Turkey and Egypt). Industries of the Middle Eastern region include oil and oil-related products, agriculture, cotton, cattle, dairy, textiles, leather products, surgical instruments, defence equipment (guns, ammunition, tanks, submarines, fighter jets, UAVs, and missiles). Banking is an important sector, especially for UAE and Bahrain. With the exception of Cyprus, Turkey, Egypt, Lebanon and Israel, tourism has been a relatively undeveloped area of the economy, in part because of the socially conservative nature of the region as well as political turmoil in certain regions. Since the end of the COVID pandemic however, countries such as the UAE, Bahrain, and Jordan have begun attracting greater numbers of tourists because of improving tourist facilities and the relaxing of tourism-related restrictive policies. Unemployment is high in the Middle East and North Africa region, particularly among people aged 15–29, a demographic representing 30% of the region's population. The total regional unemployment rate in 2025 is 10.8%, and among youth is as high as 28%. Demographics Arabs constitute the largest ethnic group in the Middle East, followed by various Iranian peoples and then by Turkic peoples (Turkish, Azeris, Syrian Turkmen, and Iraqi Turkmen). Native ethnic groups of the region include, in addition to Arabs, Arameans, Assyrians, Baloch, Berbers, Copts, Druze, Greek Cypriots, Jews, Kurds, Lurs, Mandaeans, Persians, Samaritans, Shabaks, Tats, and Zazas. European ethnic groups that form a diaspora in the region include Albanians, Bosniaks, Circassians (including Kabardians), Crimean Tatars, Greeks, Franco-Levantines, Italo-Levantines, and Iraqi Turkmens. Among other migrant populations are Chinese, Filipinos, Indians, Indonesians, Pakistanis, Pashtuns, Romani, and Afro-Arabs. "Migration has always provided an important vent for labor market pressures in the Middle East. For the period between the 1970s and 1990s, the Arab states of the Persian Gulf in particular provided a rich source of employment for workers from Egypt, Yemen and the countries of the Levant, while Europe had attracted young workers from North African countries due both to proximity and the legacy of colonial ties between France and the majority of North African states." According to the International Organization for Migration, there are 13 million first-generation migrants from Arab nations in the world, of which 5.8 reside in other Arab countries. Expatriates from Arab countries contribute to the circulation of financial and human capital in the region and thus significantly promote regional development. In 2009 Arab countries received a total of US$35.1 billion in remittance in-flows and remittances sent to Jordan, Egypt and Lebanon from other Arab countries are 40 to 190 per cent higher than trade revenues between these and other Arab countries. In Somalia, the Somali Civil War has greatly increased the size of the Somali diaspora, as many of the best educated Somalis left for Middle Eastern countries as well as Europe and North America. Non-Arab Middle Eastern countries such as Turkey, Israel and Iran are also subject to important migration dynamics. A fair proportion of those migrating from Arab nations are from ethnic and religious minorities facing persecution and are not necessarily ethnic Arabs, Iranians or Turks.[citation needed] Large numbers of Kurds, Jews, Assyrians, Greeks and Armenians as well as many Mandeans have left nations such as Iraq, Iran, Syria and Turkey for these reasons during the last century. In Iran, many religious minorities such as Christians, Baháʼís, Jews and Zoroastrians have left since the Islamic Revolution of 1979. The Middle East is very diverse when it comes to religions, many of which originated there. Islam is the largest religion in the Middle East, but other faiths that originated there, such as Judaism and Christianity, are also well represented. Christian communities have played a vital role in the Middle East, and they represent 78% of Cyprus population, and 40.5% of Lebanon, where the Lebanese president, half of the cabinet, and half of the parliament follow one of the various Lebanese Christian rites. There are also important minority religions like the Baháʼí Faith, Yarsanism, Yazidism, Zoroastrianism, Mandaeism, Druze, and Shabakism, and in ancient times the region was home to Mesopotamian religions, Canaanite religions, Manichaeism, Mithraism and various monotheist gnostic sects. The six top languages, in terms of numbers of speakers, are Arabic, Persian, Turkish, Kurdish, Modern Hebrew and Greek. About 20 minority languages are also spoken in the Middle East. Arabic, with all its dialects, is the most widely spoken language in the Middle East, with Literary Arabic being official in all North African and in most West Asian countries. Arabic dialects are also spoken in some adjacent areas in neighbouring Middle Eastern non-Arab countries. It is a member of the Semitic branch of the Afro-Asiatic languages. Several Modern South Arabian languages such as Mehri and Soqotri are also spoken in Yemen and Oman. Another Semitic language is Aramaic and its dialects are spoken mainly by Assyrians and Mandaeans, with Western Aramaic still spoken in two villages near Damascus, Syria. There is also an Oasis Berber-speaking community in Egypt where the language is also known as Siwa. It is a non-Semitic Afro-Asiatic sister language. Persian is the second most spoken language. While it is primarily spoken in Iran and some border areas in neighbouring countries, the country is one of the region's largest and most populous. It belongs to the Indo-Iranian branch of the family of Indo-European languages. Other Western Iranic languages spoken in the region include Achomi, Daylami, Kurdish dialects, Semmani, Lurish, amongst many others. The close third-most widely spoken language, Turkish, is largely confined to Turkey, which is also one of the region's largest and most populous countries, but it is present in areas in neighboring countries. It is a member of the Turkic languages, which have their origins in East Asia. Another Turkic language, Azerbaijani, is spoken by Azerbaijanis in Iran. The fourth-most widely spoken language, Kurdish, is spoken in the countries of Iran, Iraq, Syria and Turkey, Sorani Kurdish is the second official language in Iraq (instated after the 2005 constitution) after Arabic. Hebrew is the official language of Israel, with Arabic given a special status after the 2018 Basic law lowered its status from an official language prior to 2018. Hebrew is spoken and used by over 80% of Israel's population, the other 20% using Arabic. Modern Hebrew only began being spoken in the 20th century after being revived in the late 19th century by Elizer Ben-Yehuda (Elizer Perlman) and European Jewish settlers, with the first native Hebrew speaker being born in 1882. Greek is one of the two official languages of Cyprus, and the country's main language. Small communities of Greek speakers exist all around the Middle East; until the 20th century it was also widely spoken in Asia Minor (being the second most spoken language there, after Turkish) and Egypt. During the antiquity, Ancient Greek was the lingua franca for many areas of the western Middle East and until the Muslim expansion it was widely spoken there as well. Until the late 11th century, it was also the main spoken language in Asia Minor; after that it was gradually replaced by the Turkish language as the Anatolian Turks expanded and the local Greeks were assimilated, especially in the interior. English is one of the official languages of Akrotiri and Dhekelia. It is also commonly taught and used as a foreign second language, in countries such as Egypt, Jordan, Iran, Iraq, Qatar, Bahrain, United Arab Emirates and Kuwait. It is also a main language in some Emirates of the United Arab Emirates. It is also spoken as native language by Jewish immigrants from Anglophone countries (UK, US, Australia) in Israel and understood widely as second language there. French is taught and used in many government facilities and media in Lebanon, and is taught in some primary and secondary schools of Egypt and Syria. Maltese, a Semitic language mainly spoken in Europe, is used by the Franco-Maltese diaspora in Egypt. Due to widespread immigration of French Jews to Israel, it is the native language of approximately 200,000 Jews in Israel. Armenian speakers are to be found in the region. Georgian is spoken by the Georgian diaspora. Russian is spoken by a large portion of the Israeli population, because of emigration in the late 1990s. Russian today is a popular unofficial language in use in Israel; news, radio and sign boards can be found in Russian around the country after Hebrew and Arabic. Circassian is also spoken by the diaspora in the region and by almost all Circassians in Israel who speak Hebrew and English as well. The largest Romanian-speaking community in the Middle East is found in Israel, where as of 1995[update] Romanian is spoken by 5% of the population.[d] Bengali, Hindi and Urdu are widely spoken by migrant communities in many Middle Eastern countries, such as Saudi Arabia (where 20–25% of the population is South Asian), the United Arab Emirates (where 50–55% of the population is South Asian), and Qatar, which have large numbers of Pakistani, Bangladeshi and Indian immigrants. Culture The Middle East has recently become more prominent in hosting global sport events due to its wealth and desire to diversify its economy. The South Asian diaspora is a major backer of cricket in the region. See also Notes References Further reading External links 29°N 41°E / 29°N 41°E / 29; 41 |
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Contents PlayStation (console) The PlayStation[a] (codenamed PSX, abbreviated as PS, and retroactively PS1 or PS one) is a home video game console developed and marketed by Sony Computer Entertainment. It was released in Japan on 3 December 1994, followed by North America on 9 September 1995, Europe on 29 September 1995, and other regions following thereafter. As a fifth-generation console, the PlayStation primarily competed with the Nintendo 64 and the Sega Saturn. Sony began developing the PlayStation after a failed venture with Nintendo to create a CD-ROM peripheral for the Super Nintendo Entertainment System in the early 1990s. The console was primarily designed by Ken Kutaragi and Sony Computer Entertainment in Japan, while additional development was outsourced in the United Kingdom. An emphasis on 3D polygon graphics was placed at the forefront of the console's design. PlayStation game production was designed to be streamlined and inclusive, enticing the support of many third party developers. The console proved popular for its extensive game library, popular franchises, low retail price, and aggressive youth marketing which advertised it as the preferable console for adolescents and adults. Critically acclaimed games that defined the console include Gran Turismo, Crash Bandicoot, Spyro the Dragon, Tomb Raider, Resident Evil, Metal Gear Solid, Tekken 3, and Final Fantasy VII. Sony ceased production of the PlayStation on 23 March 2006—over eleven years after it had been released, and in the same year the PlayStation 3 debuted. More than 4,000 PlayStation games were released, with cumulative sales of 962 million units. The PlayStation signaled Sony's rise to power in the video game industry. It received acclaim and sold strongly; in less than a decade, it became the first computer entertainment platform to ship over 100 million units. Its use of compact discs heralded the game industry's transition from cartridges. The PlayStation's success led to a line of successors, beginning with the PlayStation 2 in 2000. In the same year, Sony released a smaller and cheaper model, the PS one. History The PlayStation was conceived by Ken Kutaragi, a Sony executive who managed a hardware engineering division and was later dubbed "the Father of the PlayStation". Kutaragi's interest in working with video games stemmed from seeing his daughter play games on Nintendo's Famicom. Kutaragi convinced Nintendo to use his SPC-700 sound processor in the Super Nintendo Entertainment System (SNES) through a demonstration of the processor's capabilities. His willingness to work with Nintendo was derived from both his admiration of the Famicom and conviction in video game consoles becoming the main home-use entertainment systems. Although Kutaragi was nearly fired because he worked with Nintendo without Sony's knowledge, president Norio Ohga recognised the potential in Kutaragi's chip and decided to keep him as a protégé. The inception of the PlayStation dates back to a 1988 joint venture between Nintendo and Sony. Nintendo had produced floppy disk technology to complement cartridges in the form of the Family Computer Disk System, and wanted to continue this complementary storage strategy for the SNES. Since Sony was already contracted to produce the SPC-700 sound processor for the SNES, Nintendo contracted Sony to develop a CD-ROM add-on, tentatively titled the "Play Station" or "SNES-CD". The PlayStation name had already been trademarked by Yamaha, but Nobuyuki Idei liked it so much that he agreed to acquire it for an undisclosed sum rather than search for an alternative. Sony was keen to obtain a foothold in the rapidly expanding video game market. Having been the primary manufacturer of the MSX home computer format, Sony had wanted to use their experience in consumer electronics to produce their own video game hardware. Although the initial agreement between Nintendo and Sony was about producing a CD-ROM drive add-on, Sony had also planned to develop a SNES-compatible Sony-branded console. This iteration was intended to be more of a home entertainment system, playing both SNES cartridges and a new CD format named the "Super Disc", which Sony would design. Under the agreement, Sony would retain sole international rights to every Super Disc game, giving them a large degree of control despite Nintendo's leading position in the video game market. Furthermore, Sony would also be the sole benefactor of licensing related to music and film software that it had been aggressively pursuing as a secondary application. The Play Station was to be announced at the 1991 Consumer Electronics Show (CES) in Las Vegas. However, Nintendo president Hiroshi Yamauchi was wary of Sony's increasing leverage at this point and deemed the original 1988 contract unacceptable upon realising it essentially handed Sony control over all games written on the SNES CD-ROM format. Although Nintendo was dominant in the video game market, Sony possessed a superior research and development department. Wanting to protect Nintendo's existing licensing structure, Yamauchi cancelled all plans for the joint Nintendo–Sony SNES CD attachment without telling Sony. He sent Nintendo of America president Minoru Arakawa (his son-in-law) and chairman Howard Lincoln to Amsterdam to form a more favourable contract with Dutch conglomerate Philips, Sony's rival. This contract would give Nintendo total control over their licences on all Philips-produced machines. Kutaragi and Nobuyuki Idei, Sony's director of public relations at the time, learned of Nintendo's actions two days before the CES was due to begin. Kutaragi telephoned numerous contacts, including Philips, to no avail. On the first day of the CES, Sony announced their partnership with Nintendo and their new console, the Play Station. At 9 am on the next day, in what has been called "the greatest ever betrayal" in the industry, Howard Lincoln stepped onto the stage and revealed that Nintendo was now allied with Philips and would abandon their work with Sony. Incensed by Nintendo's renouncement, Ohga and Kutaragi decided that Sony would develop their own console. Nintendo's contract-breaking was met with consternation in the Japanese business community, as they had broken an "unwritten law" of native companies not turning against each other in favour of foreign ones. Sony's American branch considered allying with Sega to produce a CD-ROM-based machine called the Sega Multimedia Entertainment System, but the Sega board of directors in Tokyo vetoed the idea when Sega of America CEO Tom Kalinske presented them the proposal. Kalinske recalled them saying: "That's a stupid idea, Sony doesn't know how to make hardware. They don't know how to make software either. Why would we want to do this?" Sony halted their research, but decided to develop what it had developed with Nintendo and Sega into a console based on the SNES. Despite the tumultuous events at the 1991 CES, negotiations between Nintendo and Sony were still ongoing. A deal was proposed: the Play Station would still have a port for SNES games, on the condition that it would still use Kutaragi's audio chip and that Nintendo would own the rights and receive the bulk of the profits. Roughly two hundred prototype machines were created, and some software entered development. Many within Sony were still opposed to their involvement in the video game industry, with some resenting Kutaragi for jeopardising the company. Kutaragi remained adamant that Sony not retreat from the growing industry and that a deal with Nintendo would never work. Knowing that they had to take decisive action, Sony severed all ties with Nintendo on 4 May 1992. To determine the fate of the PlayStation project, Ohga chaired a meeting in June 1992, consisting of Kutaragi and several senior Sony board members. Kutaragi unveiled a proprietary CD-ROM-based system he had been secretly working on which played games with immersive 3D graphics. Kutaragi was confident that his LSI chip could accommodate one million logic gates, which exceeded the capabilities of Sony's semiconductor division at the time. Despite gaining Ohga's enthusiasm, there remained opposition from a majority present at the meeting. Older Sony executives also opposed it, who saw Nintendo and Sega as "toy" manufacturers. The opposers felt the game industry was too culturally offbeat and asserted that Sony should remain a central player in the audiovisual industry, where companies were familiar with one another and could conduct "civili[s]ed" business negotiations. After Kutaragi reminded him of the humiliation he suffered from Nintendo, Ohga retained the project and became one of Kutaragi's most staunch supporters. Ohga shifted Kutaragi and nine of his team from Sony's main headquarters to Sony Music Entertainment Japan (SMEJ), a subsidiary of the main Sony group, so as to retain the project and maintain relationships with Philips for the MMCD development project. The involvement of SMEJ proved crucial to the PlayStation's early development as the process of manufacturing games on CD-ROM format was similar to that used for audio CDs, with which Sony's music division had considerable experience. While at SMEJ, Kutaragi worked with Epic/Sony Records founder Shigeo Maruyama and Akira Sato; both later became vice-presidents of the division that ran the PlayStation business. Sony Computer Entertainment (SCE) was jointly established by Sony and SMEJ to handle the company's ventures into the video game industry. On 27 October 1993, Sony publicly announced that it was entering the game console market with the PlayStation. According to Maruyama, there was uncertainty over whether the console should primarily focus on 2D, sprite-based graphics or 3D polygon graphics. After Sony witnessed the success of Sega's Virtua Fighter (1993) in Japanese arcades, the direction of the PlayStation became "instantly clear" and 3D polygon graphics became the console's primary focus. SCE president Teruhisa Tokunaka expressed gratitude for Sega's timely release of Virtua Fighter as it proved "just at the right time" that making games with 3D imagery was possible. Maruyama claimed that Sony further wanted to emphasise the new console's ability to utilise redbook audio from the CD-ROM format in its games alongside high quality visuals and gameplay. Wishing to distance the project from the failed enterprise with Nintendo, Sony initially branded the PlayStation the "PlayStation X" (PSX). Sony formed their European division and North American division, known as Sony Computer Entertainment Europe (SCEE) and Sony Computer Entertainment America (SCEA), in January and May 1995. The divisions planned to market the new console under the alternative branding "PSX" following the negative feedback regarding "PlayStation" in focus group studies. Early advertising prior to the console's launch in North America referenced PSX, but the term was scrapped before launch. The console was not marketed with Sony's name in contrast to Nintendo's consoles. According to Phil Harrison, much of Sony's upper management feared that the Sony brand would be tarnished if associated with the console, which they considered a "toy". Since Sony had no experience in game development, it had to rely on the support of third-party game developers. This was in contrast to Sega and Nintendo, which had versatile and well-equipped in-house software divisions for their arcade games and could easily port successful games to their home consoles. Recent consoles like the Atari Jaguar and 3DO suffered low sales due to a lack of developer support, prompting Sony to redouble their efforts in gaining the endorsement of arcade-savvy developers. A team from Epic Sony visited more than a hundred companies throughout Japan in May 1993 in hopes of attracting game creators with the PlayStation's technological appeal. Sony found that many disliked Nintendo's practices, such as favouring their own games over others. Through a series of negotiations, Sony acquired initial support from Namco, Konami, and Williams Entertainment, as well as 250 other development teams in Japan alone. Namco in particular was interested in developing for PlayStation since Namco rivalled Sega in the arcade market. Attaining these companies secured influential games such as Ridge Racer (1993) and Mortal Kombat 3 (1995), Ridge Racer being one of the most popular arcade games at the time, and it was already confirmed behind closed doors that it would be the PlayStation's first game by December 1993, despite Namco being a longstanding Nintendo developer. Namco's research managing director Shegeichi Nakamura met with Kutaragi in 1993 to discuss the preliminary PlayStation specifications, with Namco subsequently basing the Namco System 11 arcade board on PlayStation hardware and developing Tekken to compete with Virtua Fighter. The System 11 launched in arcades several months before the PlayStation's release, with the arcade release of Tekken in September 1994. Despite securing the support of various Japanese studios, Sony had no developers of their own by the time the PlayStation was in development. This changed in 1993 when Sony acquired the Liverpudlian company Psygnosis (later renamed SCE Liverpool) for US$48 million, securing their first in-house development team. The acquisition meant that Sony could have more launch games ready for the PlayStation's release in Europe and North America. Ian Hetherington, Psygnosis' co-founder, was disappointed after receiving early builds of the PlayStation and recalled that the console "was not fit for purpose" until his team got involved with it. Hetherington frequently clashed with Sony executives over broader ideas; at one point it was suggested that a television with a built-in PlayStation be produced. In the months leading up to the PlayStation's launch, Psygnosis had around 500 full-time staff working on games and assisting with software development. The purchase of Psygnosis marked another turning point for the PlayStation as it played a vital role in creating the console's development kits. While Sony had provided MIPS R4000-based Sony NEWS workstations for PlayStation development, Psygnosis employees disliked the thought of developing on these expensive workstations and asked Bristol-based SN Systems to create an alternative PC-based development system. Andy Beveridge and Martin Day, owners of SN Systems, had previously supplied development hardware for other consoles such as the Mega Drive, Atari ST, and the SNES. When Psygnosis arranged an audience for SN Systems with Sony's Japanese executives at the January 1994 CES in Las Vegas, Beveridge and Day presented their prototype of the condensed development kit, which could run on an ordinary personal computer with two extension boards. Impressed, Sony decided to abandon their plans for a workstation-based development system in favour of SN Systems's, thus securing a cheaper and more efficient method for designing software. An order of over 600 systems followed, and SN Systems supplied Sony with additional software such as an assembler, linker, and a debugger. SN Systems produced development kits for future PlayStation systems, including the PlayStation 2 and was bought out by Sony in 2005. Sony strived to make game production as streamlined and inclusive as possible, in contrast to the relatively isolated approach of Sega and Nintendo. Phil Harrison, representative director of SCEE, believed that Sony's emphasis on developer assistance reduced most time-consuming aspects of development. As well as providing programming libraries, SCE headquarters in London, California, and Tokyo housed technical support teams that could work closely with third-party developers if needed. Sony did not favour their own over non-Sony products, unlike Nintendo; Peter Molyneux of Bullfrog Productions admired Sony's open-handed approach to software developers and lauded their decision to use PCs as a development platform, remarking that "[it was] like being released from jail in terms of the freedom you have". Another strategy that helped attract software developers was the PlayStation's use of the CD-ROM format instead of traditional cartridges. Nintendo cartridges were expensive to manufacture, and the company controlled all production, prioritising their own games, while inexpensive compact disc manufacturing occurred at dozens of locations around the world. The PlayStation's architecture and interconnectability with PCs was beneficial to many software developers. The use of the programming language C proved useful, as it safeguarded future compatibility of the machine should developers decide to make further hardware revisions. Despite the inherent flexibility, some developers found themselves restricted due to the console's lack of RAM. While working on beta builds of the PlayStation, Molyneux observed that its MIPS processor was not "quite as bullish" compared to that of a fast PC and said that it took his team two weeks to port their PC code to the PlayStation development kits and another fortnight to achieve a four-fold speed increase. An engineer from Ocean Software, one of Europe's largest game developers at the time, thought that allocating RAM was a challenging aspect given the 3.5 megabyte restriction. Kutaragi said that while it would have been easy to double the amount of RAM for the PlayStation, the development team refrained from doing so to keep the retail cost down. Kutaragi saw the biggest challenge in developing the system to be balancing the conflicting goals of high performance, low cost, and being easy to program for, and felt he and his team were successful in this regard. Its technical specifications were finalised in 1993 and its design during 1994. The PlayStation name and its final design were confirmed during a press conference on May 10, 1994, although the price and release dates had not been disclosed yet. Sony released the PlayStation in Japan on 3 December 1994, a week after the release of the Sega Saturn, at a price of ¥39,800. Sales in Japan began with a "stunning" success with long queues in shops. Ohga later recalled that he realised how important PlayStation had become for Sony when friends and relatives begged for consoles for their children. PlayStation sold 100,000 units on the first day and two million units within six months, although the Saturn outsold the PlayStation in the first few weeks due to the success of Virtua Fighter. By the end of 1994, 300,000 PlayStation units were sold in Japan compared to 500,000 Saturn units. A grey market emerged for PlayStations shipped from Japan to North America and Europe, with buyers of such consoles paying up to £700. "When September 1995 arrived and Sony's Playstation roared out of the gate, things immediately felt different than [sic] they did with the Saturn launch earlier that year. Sega dropped the Saturn $100 to match the Playstation's $299 debut price, but sales weren't even close—Playstations flew out the door as fast as we could get them in stock. Before the release in North America, Sega and Sony presented their consoles at the first Electronic Entertainment Expo (E3) in Los Angeles on 11 May 1995. At their keynote presentation, Sega of America CEO Tom Kalinske revealed that their Saturn console would be released immediately to select retailers at a price of $399. Next came Sony's turn: Olaf Olafsson, the head of SCEA, summoned Steve Race, the head of development, to the conference stage, who said "$299" and left the audience with a round of applause. The attention to the Sony conference was further bolstered by the surprise appearance of Michael Jackson and the showcase of highly anticipated games, including Wipeout (1995), Ridge Racer and Tekken (1994). In addition, Sony announced that no games would be bundled with the console. Although the Saturn had released early in the United States to gain an advantage over the PlayStation, the surprise launch upset many retailers who were not informed in time, harming sales. Some retailers such as KB Toys responded by dropping the Saturn entirely. The PlayStation went on sale in North America on 9 September 1995. It sold more units within two days than the Saturn had in five months, with almost all of the initial shipment of 100,000 units sold in advance and shops across the country running out of consoles and accessories. The well-received Ridge Racer contributed to the PlayStation's early success, — with some critics considering it superior to Sega's arcade counterpart Daytona USA (1994) — as did Battle Arena Toshinden (1995). There were over 100,000 pre-orders placed and 17 games available on the market by the time of the PlayStation's American launch, in comparison to the Saturn's six launch games. The PlayStation released in Europe on 29 September 1995 and in Australia on 15 November 1995. By November it had already outsold the Saturn by three to one in the United Kingdom, where Sony had allocated a £20 million marketing budget during the Christmas season compared to Sega's £4 million. Sony found early success in the United Kingdom by securing listings with independent shop owners as well as prominent High Street chains such as Comet and Argos. Within its first year, the PlayStation secured over 20% of the entire American video game market. From September to the end of 1995, sales in the United States amounted to 800,000 units, giving the PlayStation a commanding lead over the other fifth-generation consoles,[b] though the SNES and Mega Drive from the fourth generation still outsold it. Sony reported that the attach rate of sold games and consoles was four to one. To meet increasing demand, Sony chartered jumbo jets and ramped up production in Europe and North America. By early 1996, the PlayStation had grossed $2 billion (equivalent to $4.106 billion 2025) from worldwide hardware and software sales. By late 1996, sales in Europe totalled 2.2 million units, including 700,000 in the UK. Approximately 400 PlayStation games were in development, compared to around 200 games being developed for the Saturn and 60 for the Nintendo 64. In India, the PlayStation was launched in test market during 1999–2000 across Sony showrooms, selling 100 units. Sony finally launched the console (PS One model) countrywide on 24 January 2002 with the price of Rs 7,990 and 26 games available from start. PlayStation was also doing well in markets where it was never officially released. For example, in Brazil, due to the registration of the trademark by a third company, the console could not be released, which was why the market was taken over by the officially distributed Sega Saturn during the first period, but as the Sega console withdraws, PlayStation imports and large piracy increased. In another market, China, the most popular 32-bit console was Sega Saturn, but after leaving the market, PlayStation grown with a base of 300,000 users until January 2000, although Sony China did not have plans to release it. The PlayStation was backed by a successful marketing campaign, allowing Sony to gain an early foothold in Europe and North America. Initially, PlayStation demographics were skewed towards adults, but the audience broadened after the first price drop. While the Saturn was positioned towards 18- to 34-year-olds, the PlayStation was initially marketed exclusively towards teenagers. Executives from both Sony and Sega reasoned that because younger players typically looked up to older, more experienced players, advertising targeted at teens and adults would draw them in too. Additionally, Sony found that adults reacted best to advertising aimed at teenagers; Lee Clow surmised that people who started to grow into adulthood regressed and became "17 again" when they played video games. The console was marketed with advertising slogans stylised as "LIVE IN YUR WRLD. PLY IN URS" (Live in Your World. Play in Ours.) and "U R NOT E" (red E). The four geometric shapes were derived from the symbols for the four buttons on the controller. Clow thought that by invoking such provocative statements, gamers would respond to the contrary and say "'Bullshit. Let me show you how ready I am.'" As the console's appeal enlarged, Sony's marketing efforts broadened from their earlier focus on mature players to specifically target younger children as well. Shortly after the PlayStation's release in Europe, Sony tasked marketing manager Geoff Glendenning with assessing the desires of a new target audience. Sceptical over Nintendo and Sega's reliance on television campaigns, Glendenning theorised that young adults transitioning from fourth-generation consoles would feel neglected by marketing directed at children and teenagers. Recognising the influence early 1990s underground clubbing and rave culture had on young people, especially in the United Kingdom, Glendenning felt that the culture had become mainstream enough to help cultivate PlayStation's emerging identity. Sony partnered with prominent nightclub owners such as Ministry of Sound and festival promoters to organise dedicated PlayStation areas where demonstrations of select games could be tested. Sheffield-based graphic design studio The Designers Republic was contracted by Sony to produce promotional materials aimed at a fashionable, club-going audience. Psygnosis' Wipeout in particular became associated with nightclub culture as it was widely featured in venues. By 1997, there were 52 nightclubs in the United Kingdom with dedicated PlayStation rooms. Glendenning recalled that he had discreetly used at least £100,000 a year in slush fund money to invest in impromptu marketing. In 1996, Sony expanded their CD production facilities in the United States due to the high demand for PlayStation games, increasing their monthly output from 4 million discs to 6.5 million discs. This was necessary because PlayStation sales were running at twice the rate of Saturn sales, and its lead dramatically increased when both consoles dropped in price to $199 that year. The PlayStation also outsold the Saturn at a similar ratio in Europe during 1996, with 2.2 million consoles sold in the region by the end of the year. Sales figures for PlayStation hardware and software only increased following the launch of the Nintendo 64. Tokunaka speculated that the Nintendo 64 launch had actually helped PlayStation sales by raising public awareness of the gaming market through Nintendo's added marketing efforts. Despite this, the PlayStation took longer to achieve dominance in Japan. Tokunaka said that, even after the PlayStation and Saturn had been on the market for nearly two years, the competition between them was still "very close", and neither console had led in sales for any meaningful length of time. By 1998, Sega, encouraged by their declining market share and significant financial losses, launched the Dreamcast as a last-ditch attempt to stay in the industry. Although its launch was successful, the technically superior 128-bit console was unable to subdue Sony's dominance in the industry. Sony still held 60% of the overall video game market share in North America at the end of 1999. Sega's initial confidence in their new console was undermined when Japanese sales were lower than expected, with disgruntled Japanese consumers reportedly returning their Dreamcasts in exchange for PlayStation software. On 2 March 1999, Sony officially revealed details of the PlayStation 2, which Kutaragi announced would feature a graphics processor designed to push more raw polygons than any console in history, effectively rivalling most supercomputers. The PlayStation continued to sell strongly at the turn of the new millennium: in June 2000, Sony released the PSOne, a smaller, redesigned variant which went on to outsell all other consoles in that year, including the PlayStation 2. In 2005, PlayStation became the first console to ship 100 million units with the PlayStation 2 later achieving this faster than its predecessor. The combined successes of both PlayStation consoles led to Sega retiring the Dreamcast in 2001, and abandoning the console business entirely. The PlayStation was eventually discontinued on 23 March 2006—over eleven years after its release, and less than a year before the debut of the PlayStation 3. Hardware The main microprocessor is a R3000 CPU made by LSI Logic operating at a clock rate of 33.8688 MHz and 30 MIPS. This 32-bit CPU relies heavily on the "cop2" 3D and matrix math coprocessor on the same die to provide the necessary speed to render complex 3D graphics. The role of the separate GPU chip is to draw 2D polygons and apply shading and textures to them: the rasterisation stage of the graphics pipeline. Sony's custom 16-bit sound chip supports ADPCM sources with up to 24 sound channels and offers a sampling rate of up to 44.1 kHz and music sequencing. It features 2 MB of main RAM, with an additional 1 MB of video RAM. The PlayStation has a maximum colour depth of 16.7 million true colours with 32 levels of transparency and unlimited colour look-up tables. The PlayStation can output composite, S-Video or RGB video signals through its AV Multi connector (with older models also having RCA connectors for composite), displaying resolutions from 256×224 to 640×480 pixels. Different games can use different resolutions. Earlier models also had proprietary parallel and serial ports that could be used to connect accessories or multiple consoles together; these were later removed due to a lack of usage. The PlayStation uses a proprietary video compression unit, MDEC, which is integrated into the CPU and allows for the presentation of full motion video at a higher quality than other consoles of its generation. Unusual for the time, the PlayStation lacks a dedicated 2D graphics processor; 2D elements are instead calculated as polygons by the Geometry Transfer Engine (GTE) so that they can be processed and displayed on screen by the GPU. While running, the GPU can also generate a total of 4,000 sprites and 180,000 polygons per second, in addition to 360,000 per second flat-shaded. The PlayStation went through a number of variants during its production run. Externally, the most notable change was the gradual reduction in the number of external connectors from the rear of the unit. This started with the original Japanese launch units; the SCPH-1000, released on 3 December 1994, was the only model that had an S-Video port, as it was removed from the next model. Subsequent models saw a reduction in number of parallel ports, with the final version only retaining one serial port. Sony marketed a development kit for amateur developers known as the Net Yaroze (meaning "Let's do it together" in Japanese). It was launched in June 1996 in Japan, and following public interest, was released the next year in other countries. The Net Yaroze allowed hobbyists to create their own games and upload them via an online forum run by Sony. The console was only available to buy through an ordering service and with the necessary documentation and software to program PlayStation games and applications through C programming compilers. On 7 July 2000, Sony released the PS One (stylised as "PS one" or "PSone"), a smaller, redesigned version of the original PlayStation. It was the highest-selling console through the end of the year, outselling all other consoles—including the PlayStation 2. In 2002, Sony released a 5-inch (130 mm) LCD screen add-on for the PS One, referred to as the "Combo pack". It also included a car cigarette lighter adaptor adding an extra layer of portability. Production of the LCD "Combo Pack" ceased in 2004, when the popularity of the PlayStation began to wane in markets outside Japan. A total of 28.15 million PS One units had been sold by the time it was discontinued in March 2006. Three iterations of the PlayStation's controller were released over the console's lifespan. The first controller, the PlayStation controller, was released alongside the PlayStation in December 1994. It features four individual directional buttons (as opposed to a conventional D-pad), a pair of shoulder buttons on both sides, Start and Select buttons in the centre, and four face buttons consisting of simple geometric shapes: a green triangle, red circle, blue cross, and a pink square (, , , ). Rather than depicting traditionally used letters or numbers onto its buttons, the PlayStation controller established a trademark which would be incorporated heavily into the PlayStation brand. Teiyu Goto, the designer of the original PlayStation controller, said that the circle and cross represent "yes" and "no", respectively (though this layout is reversed in Western versions); the triangle symbolises a point of view and the square is equated to a sheet of paper to be used to access menus. The European and North American models of the original PlayStation controllers are roughly 10% larger than its Japanese variant, to account for the fact the average person in those regions has larger hands than the average Japanese person. Sony's first analogue gamepad, the PlayStation Analog Joystick (often erroneously referred to as the "Sony Flightstick"), was first released in Japan in April 1996. Featuring two parallel joysticks, it uses potentiometer technology previously used on consoles such as the Vectrex; instead of relying on binary eight-way switches, the controller detects minute angular changes through the entire range of motion. The stick also features a thumb-operated digital hat switch on the right joystick, corresponding to the traditional D-pad, and used for instances when simple digital movements were necessary. The Analog Joystick sold poorly in Japan due to its high cost and cumbersome size. The increasing popularity of 3D games prompted Sony to add analogue sticks to its controller design to give users more freedom over their movements in virtual 3D environments. The first official analogue controller, the Dual Analog Controller, was revealed to the public in a small glass booth at the 1996 PlayStation Expo in Japan, and released in April 1997 to coincide with the Japanese releases of analogue-capable games Tobal 2 and Bushido Blade. In addition to the two analogue sticks (which also introduced two new buttons mapped to clicking in the analogue sticks), the Dual Analog controller features an "Analog" button and LED beneath the "Start" and "Select" buttons which toggles analogue functionality on or off. The controller also features rumble support, though Sony decided that haptic feedback would be removed from all overseas iterations before the United States release. A Sony spokesman stated that the feature was removed for "manufacturing reasons", although rumours circulated that Nintendo had attempted to legally block the release of the controller outside Japan due to similarities with the Nintendo 64 controller's Rumble Pak. However, a Nintendo spokesman denied that Nintendo took legal action. Next Generation's Chris Charla theorised that Sony dropped vibration feedback to keep the price of the controller down. In November 1997, Sony introduced the DualShock controller. Its name derives from its use of two (dual) vibration motors (shock). Unlike its predecessor, its analogue sticks feature textured rubber grips, longer handles, slightly different shoulder buttons and has rumble feedback included as standard on all versions. The DualShock later replaced its predecessors as the default controller. Sony released a series of peripherals to add extra layers of functionality to the PlayStation. Such peripherals include memory cards, the PlayStation Mouse, the PlayStation Link Cable, the Multiplayer Adapter (a four-player multitap), the Memory Drive (a disk drive for 3.5-inch floppy disks), the GunCon (a light gun), and the Glasstron (a monoscopic head-mounted display). Released exclusively in Japan, the PocketStation is a memory card peripheral which acts as a miniature personal digital assistant. The device features a monochrome liquid crystal display (LCD), infrared communication capability, a real-time clock, built-in flash memory, and sound capability. Sharing similarities with the Dreamcast's VMU peripheral, the PocketStation was typically distributed with certain PlayStation games, enhancing them with added features. The PocketStation proved popular in Japan, selling over five million units. Sony planned to release the peripheral outside Japan but the release was cancelled, despite receiving promotion in Europe and North America. In addition to playing games, most PlayStation models are equipped to play CD-Audio. The Asian model SCPH-5903 can also play Video CDs. Like most CD players, the PlayStation can play songs in a programmed order, shuffle the playback order of the disc and repeat one song or the entire disc. Later PlayStation models use a music visualisation function called SoundScope. This function, as well as a memory card manager, is accessed by starting the console without either inserting a game or closing the CD tray, thereby accessing a graphical user interface (GUI) for the PlayStation BIOS. The GUI for the PS One and PlayStation differ depending on the firmware version: the original PlayStation GUI had a dark blue background with rainbow graffiti used as buttons, while the early PAL PlayStation and PS One GUI had a grey blocked background with two icons in the middle. PlayStation emulation is versatile and can be run on numerous modern devices. Bleem! was a commercial emulator which was released for IBM-compatible PCs and the Dreamcast in 1999. It was notable for being aggressively marketed during the PlayStation's lifetime, and was the centre of multiple controversial lawsuits filed by Sony. Bleem! was programmed in assembly language, which allowed it to emulate PlayStation games with improved visual fidelity, enhanced resolutions, and filtered textures that was not possible on original hardware. Sony sued Bleem! two days after its release, citing copyright infringement and accusing the company of engaging in unfair competition and patent infringement by allowing use of PlayStation BIOSs on a Sega console. Bleem! were subsequently forced to shut down in November 2001. Sony was aware that using CDs for game distribution could have left games vulnerable to piracy, due to the growing popularity of CD-R and optical disc drives with burning capability. To preclude illegal copying, a proprietary process for PlayStation disc manufacturing was developed that, in conjunction with an augmented optical drive in Tiger H/E assembly, prevented burned copies of games from booting on an unmodified console. Specifically, all genuine PlayStation discs were printed with a small section of deliberate irregular data, which the PlayStation's optical pick-up was capable of detecting and decoding. Consoles would not boot game discs without a specific wobble frequency contained in the data of the disc pregap sector (the same system was also used to encode discs' regional lockouts). This signal was within Red Book CD tolerances, so PlayStation discs' actual content could still be read by a conventional disc drive; however, the disc drive could not detect the wobble frequency (therefore duplicating the discs omitting it), since the laser pick-up system of any optical disc drive would interpret this wobble as an oscillation of the disc surface and compensate for it in the reading process. Early PlayStations, particularly early 1000 models, experience skipping full-motion video or physical "ticking" noises from the unit. The problems stem from poorly placed vents leading to overheating in some environments, causing the plastic mouldings inside the console to warp slightly and create knock-on effects with the laser assembly. The solution is to sit the console on a surface which dissipates heat efficiently in a well vented area or raise the unit up slightly from its resting surface. Sony representatives also recommended unplugging the PlayStation when it is not in use, as the system draws in a small amount of power (and therefore heat) even when turned off. The first batch of PlayStations use a KSM-440AAM laser unit, whose case and movable parts are all built out of plastic. Over time, the plastic lens sled rail wears out—usually unevenly—due to friction. The placement of the laser unit close to the power supply accelerates wear, due to the additional heat, which makes the plastic more vulnerable to friction. Eventually, one side of the lens sled will become so worn that the laser can tilt, no longer pointing directly at the CD; after this, games will no longer load due to data read errors. Sony fixed the problem by making the sled out of die-cast metal and placing the laser unit further away from the power supply on later PlayStation models. Due to an engineering oversight, the PlayStation does not produce a proper signal on several older models of televisions, causing the display to flicker or bounce around the screen. Sony decided not to change the console design, since only a small percentage of PlayStation owners used such televisions, and instead gave consumers the option of sending their PlayStation unit to a Sony service centre to have an official modchip installed, allowing play on older televisions. Game library The PlayStation featured a diverse game library which grew to appeal to all types of players. Critically acclaimed PlayStation games included Final Fantasy VII (1997), Crash Bandicoot (1996), Spyro the Dragon (1998), Metal Gear Solid (1998), all of which became established franchises. Final Fantasy VII is credited with allowing role-playing games to gain mass-market appeal outside Japan, and is considered one of the most influential and greatest video games ever made. The PlayStation's bestselling game is Gran Turismo (1997), which sold 10.85 million units. After the PlayStation's discontinuation in 2006, the cumulative software shipment was 962 million units. Following its 1994 launch in Japan, early games included Ridge Racer, Crime Crackers, King's Field, Motor Toon Grand Prix, Toh Shin Den (i.e. Battle Arena Toshinden), and Kileak: The Blood. The first two games available at its later North American launch were Jumping Flash! (1995) and Ridge Racer, with Jumping Flash! heralded as an ancestor for 3D graphics in console gaming. Wipeout, Air Combat, Twisted Metal, Warhawk and Destruction Derby were among the popular first-year games, and the first to be reissued as part of Sony's Greatest Hits or Platinum range. At the time of the PlayStation's first Christmas season, Psygnosis had produced around 70% of its launch catalogue; their breakthrough racing game Wipeout was acclaimed for its techno soundtrack and helped raise awareness of Britain's underground music community. Eidos Interactive's action-adventure game Tomb Raider contributed substantially to the success of the console in 1996, with its main protagonist Lara Croft becoming an early gaming icon and garnering unprecedented media promotion. Licensed tie-in video games of popular films were also prevalent; Argonaut Games' 2001 adaptation of Harry Potter and the Philosopher's Stone went on to sell over eight million copies late in the console's lifespan. Third-party developers committed largely to the console's wide-ranging game catalogue even after the launch of the PlayStation 2; some of the notable exclusives in this era include Harry Potter and the Philosopher's Stone, Fear Effect 2: Retro Helix, Syphon Filter 3, C-12: Final Resistance, Dance Dance Revolution Konamix and Digimon World 3.[c] Sony assisted with game reprints as late as 2008 with Metal Gear Solid: The Essential Collection, this being the last PlayStation game officially released and licensed by Sony. Initially, in the United States, PlayStation games were packaged in long cardboard boxes, similar to non-Japanese 3DO and Saturn games. Sony later switched to the jewel case format typically used for audio CDs and Japanese video games, as this format took up less retailer shelf space (which was at a premium due to the large number of PlayStation games being released), and focus testing showed that most consumers preferred this format. Reception The PlayStation was mostly well received upon release. Critics in the west generally welcomed the new console; the staff of Next Generation reviewed the PlayStation a few weeks after its North American launch, where they commented that, while the CPU is "fairly average", the supplementary custom hardware, such as the GPU and sound processor, is stunningly powerful. They praised the PlayStation's focus on 3D, and complemented the comfort of its controller and the convenience of its memory cards. Giving the system 41⁄2 out of 5 stars, they concluded, "To succeed in this extremely cut-throat market, you need a combination of great hardware, great games, and great marketing. Whether by skill, luck, or just deep pockets, Sony has scored three out of three in the first salvo of this war." Albert Kim from Entertainment Weekly praised the PlayStation as a technological marvel, rivalling that of Sega and Nintendo. Famicom Tsūshin scored the console a 19 out of 40, lower than the Saturn's 24 out of 40, in May 1995. In a 1997 year-end review, a team of five Electronic Gaming Monthly editors gave the PlayStation scores of 9.5, 8.5, 9.0, 9.0, and 9.5—for all five editors, the highest score they gave to any of the five consoles reviewed in the issue. They lauded the breadth and quality of the games library, saying it had vastly improved over previous years due to developers mastering the system's capabilities in addition to Sony revising their stance on 2D and role playing games. They also complimented the low price point of the games compared to the Nintendo 64's, and noted that it was the only console on the market that could be relied upon to deliver a solid stream of games for the coming year, primarily due to third party developers almost unanimously favouring it over its competitors. Legacy SCE was an upstart in the video game industry in late 1994, as the video game market in the early 1990s was dominated by Nintendo and Sega. Nintendo had been the clear leader in the industry since the introduction of the Nintendo Entertainment System in 1985 and the Nintendo 64 was initially expected to maintain this position. The PlayStation's target audience included the generation which was the first to grow up with mainstream video games, along with 18- to 29-year-olds who were not the primary focus of Nintendo. By the late 1990s, Sony became a highly regarded console brand due to the PlayStation, with a significant lead over second-place Nintendo, while Sega was relegated to a distant third. The PlayStation became the first "computer entertainment platform" to ship over 100 million units worldwide, with many critics attributing the console's success to third-party developers. It remains the sixth best-selling console of all time as of 2025[update], with a total of 102.49 million units sold. Around 7,900 individual games were published for the console during its 11-year life span, the second-most games ever produced for a console. Its success resulted in a significant financial boon for Sony as profits from their video game division contributed to 23%. Sony's next-generation PlayStation 2, which is backward compatible with the PlayStation's DualShock controller and games, was announced in 1999 and launched in 2000. The PlayStation's lead in installed base and developer support paved the way for the success of its successor, which overcame the earlier launch of the Sega's Dreamcast and then fended off competition from Microsoft's newcomer Xbox and Nintendo's GameCube. The PlayStation 2's immense success and failure of the Dreamcast were among the main factors which led to Sega abandoning the console market. To date, five PlayStation home consoles have been released, which have continued the same numbering scheme, as well as two portable systems. The PlayStation 3 also maintained backward compatibility with original PlayStation discs. Hundreds of PlayStation games have been digitally re-released on the PlayStation Portable, PlayStation 3, PlayStation Vita, PlayStation 4, and PlayStation 5. The PlayStation has often ranked among the best video game consoles. In 2018, Retro Gamer named it the third best console, crediting its sophisticated 3D capabilities as one of its key factors in gaining mass success, and lauding it as a "game-changer in every sense possible". In 2009, IGN ranked the PlayStation the seventh best console in their list, noting its appeal towards older audiences to be a crucial factor in propelling the video game industry, as well as its assistance in transitioning game industry to use the CD-ROM format. Keith Stuart from The Guardian likewise named it as the seventh best console in 2020, declaring that its success was so profound it "ruled the 1990s". In January 2025, Lorentio Brodesco announced the nsOne project, attempting to reverse engineer PlayStation's motherboard. Brodesco stated that "detailed documentation on the original motherboard was either incomplete or entirely unavailable". The project was successfully crowdfunded via Kickstarter. In June, Brodesco manufactured the first working motherboard, promising to bring a fully rooted version with multilayer routing as well as documentation and design files in the near future. The success of the PlayStation contributed to the demise of cartridge-based home consoles. While not the first system to use an optical disc format, it was the first highly successful one, and ended up going head-to-head with the proprietary cartridge-relying Nintendo 64,[d] which the industry had expected to use CDs like PlayStation. After the demise of the Sega Saturn, Nintendo was left as Sony's main competitor in Western markets. Nintendo chose not to use CDs for the Nintendo 64; they were likely concerned with the proprietary cartridge format's ability to help enforce copy protection, given their substantial reliance on licensing and exclusive games for their revenue. Besides their larger capacity, CD-ROMs could be produced in bulk quantities at a much faster rate than ROM cartridges, a week compared to two to three months. Further, the cost of production per unit was far cheaper, allowing Sony to offer games about 40% lower cost to the user compared to ROM cartridges while still making the same amount of net revenue. In Japan, Sony published fewer copies of a wide variety of games for the PlayStation as a risk-limiting step, a model that had been used by Sony Music for CD audio discs. The production flexibility of CD-ROMs meant that Sony could produce larger volumes of popular games to get onto the market quickly, something that could not be done with cartridges due to their manufacturing lead time. The lower production costs of CD-ROMs also allowed publishers an additional source of profit: budget-priced reissues of games which had already recouped their development costs. Tokunaka remarked in 1996: Choosing CD-ROM is one of the most important decisions that we made. As I'm sure you understand, PlayStation could just as easily have worked with masked ROM [cartridges]. The 3D engine and everything—the whole PlayStation format—is independent of the media. But for various reasons (including the economies for the consumer, the ease of the manufacturing, inventory control for the trade, and also the software publishers) we deduced that CD-ROM would be the best media for PlayStation. The increasing complexity of developing games pushed cartridges to their storage limits and gradually discouraged some third-party developers. Part of the CD format's appeal to publishers was that they could be produced at a significantly lower cost and offered more production flexibility to meet demand. As a result, some third-party developers switched to the PlayStation, including Square and Enix, whose Final Fantasy VII and Dragon Quest VII respectively had been planned for the Nintendo 64 (both companies later merged to form Square Enix). Other developers released fewer games for the Nintendo 64 (Konami, releasing only thirteen N64 games but over fifty on the PlayStation). Nintendo 64 game releases were less frequent than the PlayStation's, with many being developed by either Nintendo themselves or second-parties such as Rare. The PlayStation Classic is a dedicated video game console made by Sony Interactive Entertainment that emulates PlayStation games. It was announced in September 2018 at the Tokyo Game Show, and released on 3 December 2018, the 24th anniversary of the release of the original console. As a dedicated console, the PlayStation Classic features 20 pre-installed games; the games run off the open source emulator PCSX. The console is bundled with two replica wired PlayStation controllers (those without analogue sticks), an HDMI cable, and a USB-Type A cable. Internally, the console uses a MediaTek MT8167a Quad A35 system on a chip with four central processing cores clocked at @ 1.5 GHz and a Power VR GE8300 graphics processing unit. It includes 16 GB of eMMC flash storage and 1 Gigabyte of DDR3 SDRAM. The PlayStation Classic is 45% smaller than the original console. The PlayStation Classic received negative reviews from critics and was compared unfavorably to Nintendo's rival Nintendo Entertainment System Classic Edition and Super Nintendo Entertainment System Classic Edition. Criticism was directed at its meagre game library, user interface, emulation quality, use of PAL versions for certain games, use of the original controller, and high retail price, though the console's design received praise. The console sold poorly. See also Notes References |
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[SOURCE: https://en.wikipedia.org/wiki/Astronomy_on_Mars] | [TOKENS: 3929] |
Contents Astronomy on Mars Many astronomical phenomena viewed from the planet Mars are the same as or similar to those seen from Earth; but some (e.g. the view of Earth as an evening/morning star) are quite different. For example, because the atmosphere of Mars does not contain an ozone layer, it is also possible to make UV observations from the surface of Mars. Seasons Mars has an axial tilt of 25.19°, quite close to the value of 23.44° for Earth, and thus Mars has seasons of spring, summer, autumn, winter as Earth does. As on Earth, the southern and northern hemispheres have summer and winter at opposing times. However, the orbit of Mars has significantly greater eccentricity than that of Earth. Therefore, the seasons are of unequal length, much more so than on Earth: In practical terms, this means that summers and winters have different lengths and intensities in the northern and southern hemispheres. Winters in the north are warm and short (because Mars is moving fast near its perihelion), while winters in the south are long and cold (Mars is moving slowly near aphelion). Similarly, summers in the north are long and cool, while summers in the south are short and hot. Therefore, extremes of temperature are considerably wider in the southern hemisphere than in the north. The seasonal lag on Mars is no more than a couple of days, due to its lack of large bodies of water and similar factors that would provide a buffering effect. Thus, for temperatures on Mars, "spring" is approximately the mirror image of "summer" and "autumn" is approximately the mirror image of "winter" (if the solstices and equinoxes are defined to be the beginnings of their respective seasons), and if Mars had a circular orbit the maximum and minimum temperatures would occur a couple of days after the summer and winter solstices, rather than about one month after, as on Earth. The only difference between spring temperatures and summer temperatures is due to the relatively high eccentricity of Mars's orbit: in northern spring Mars is farther from the Sun than during northern summer, and therefore by coincidence spring is slightly cooler than summer and autumn is slightly warmer than winter. However, in the southern hemisphere the opposite is true. The temperature variations between spring and summer are much less than the very sharp variations that occur within a single Martian sol (solar day). On a daily basis, temperatures peak at local solar noon and reach a minimum at local midnight. This is similar to the effect in Earth's deserts, only much more pronounced. The axial tilt and eccentricity of Earth (and Mars) are by no means fixed, but rather vary due to gravitational perturbations from other planets in the Solar System on a timescale of tens of thousands or hundreds of thousands of years. Thus, for example Earth's eccentricity, currently about 1% regularly fluctuates and can increase up to 6%. Aside from the eccentricity, the Earth's axial tilt can also vary from 21.5° to 24.5°, and the length of this "obliquity cycle" is 41,000 years. These and other similar cyclical changes are thought to be responsible for ice ages (see Milankovitch cycles). By contrast, the obliquity cycle for Mars is much more extreme: from 15° to 35° over a 124,000-year cycle. Some recent studies even suggest that over tens of millions of years, the swing may be as much as 0° to 60°. Earth's large Moon apparently plays an important role in keeping Earth's axial tilt within reasonable bounds; Mars has no such stabilizing influence, and its axial tilt can vary more chaotically. The color of the sky The normal hue of the sky during the daytime can vary from a pinkish-red to a yellow-brown “butterscotch” color; however, in the vicinity of the setting or rising sun it is blue. This is the exact opposite of the situation on Earth. On Mars, Rayleigh scattering is usually a very small effect. It is believed that the color of the sky is caused by the presence of 1% by volume of magnetite in the dust particles. Twilight lasts a long time after the Sun has set and before it rises, because of all the dust in Mars's atmosphere. At times, the Martian sky takes on a violet color, due to scattering of light by very small water ice particles in clouds. Generating accurate true-color images of Mars's surface is surprisingly complicated. There is much variation in the color of the sky as reproduced in published images; many of those images, however, are using filters to maximize the scientific value and are not trying to show true color.[citation needed] Nevertheless, for many years, the sky on Mars was thought to be more pinkish than it now is believed to be.[citation needed] Astronomical phenomena As seen from Mars, the Earth is an inner planet like Venus (a "morning star" or "evening star"). The Earth and Moon appear starlike to the naked eye, but observers with telescopes would see them as crescents, with some detail visible. An observer on Mars would be able to see the Moon orbiting around the Earth, and this would easily be visible to the naked eye. By contrast, observers on Earth cannot see any other planet's satellites with the naked eye, and it was not until soon after the invention of the telescope that the first such satellites were discovered (Jupiter's Galilean moons). At maximum angular separation, the Earth and Moon would be easily distinguished as a double planet, but about one week later they would merge into a single point of light (to the naked eye), and then about a week after that, the Moon would reach maximum angular separation on the opposite side. The maximum angular separation of the Earth and Moon varies considerably according to the relative distance between the Earth and Mars: it is about 25′ (arcminutes) when Earth is closest to Mars (near inferior conjunction) but only about 3.5′ when the Earth is farthest from Mars (near superior conjunction). For comparison, the apparent diameter of the Moon from Earth is 31′. The minimum angular separation would be less than 1′, and occasionally the Moon would be seen to transit in front of or pass behind (be occulted by) the Earth. The former case would correspond to a lunar occultation of Mars as seen from Earth, and because the Moon's albedo is considerably less than that of the Earth, a dip in overall brightness would occur, although this would be too small to be noticeable by casual naked eye observers because the size of the Moon is much smaller than that of the Earth and it would cover only a small fraction of the Earth's disk. Mars Global Surveyor imaged the Earth and Moon on May 8, 2003, 13:00 UTC, very close to maximum angular elongation from the Sun and at a distance of 0.930 AU from Mars. The apparent magnitudes were given as −2.5 and +0.9. At different times the actual magnitudes will vary considerably depending on distance and the phases of the Earth and Moon. From one day to the next, the view of the Moon would change considerably for an observer on Mars than for an observer on Earth. The phase of the Moon as seen from Mars would not change much from day to day; it would match the phase of the Earth, and would only gradually change as both Earth and Moon move in their orbits around the Sun. On the other hand, an observer on Mars would see the Moon rotate, with the same period as its orbital period, and would see far side features that can never be seen from Earth. Since Earth is an inferior planet, observers on Mars can occasionally view transits of Earth across the Sun. The next one will take place in 2084. They can also view transits of Mercury and transits of Venus. The moon Phobos appears about one third the angular diameter that the full Moon appears from Earth; on the other hand, Deimos appears more or less starlike with a disk barely discernible if at all. Phobos orbits so fast (with a period of just under one third of a sol) that it rises in the west and sets in the east, and does so twice per sol; Deimos on the other hand rises in the east and sets in the west, but orbits only a few hours slower than a Martian sol, so it spends about two and a half sols above the horizon at a time. The maximum brightness of Phobos at "full moon" is about magnitude −9 or −10, while for Deimos it is about −5. By comparison, the full Moon as seen from Earth is considerably brighter at magnitude −12.7. Phobos is still bright enough to cast shadows; Deimos is only slightly brighter than Venus is from Earth. Just like Earth's Moon, both Phobos and Deimos are considerably fainter at non-full phases. Unlike Earth's Moon, Phobos's phases and angular diameter visibly change from hour to hour; Deimos is too small for its phases to be visible with the naked eye. Both Phobos and Deimos have low-inclination equatorial orbits and orbit fairly close to Mars. As a result, Phobos is not visible from latitudes north of 70.4°N or south of 70.4°S; Deimos is not visible from latitudes north of 82.7°N or south of 82.7°S. Observers at high latitudes (less than 70.4°) would see a noticeably smaller angular diameter for Phobos because they are farther away from it. Similarly, equatorial observers of Phobos would see a noticeably smaller angular diameter for Phobos when it is rising and setting, compared to when it is overhead. Observers on Mars can view transits of Phobos and transits of Deimos across the Sun. The transits of Phobos could also be called partial eclipses of the Sun by Phobos, since the angular diameter of Phobos is up to half the angular diameter of the Sun. However, in the case of Deimos the term "transit" is appropriate, since it appears as a small dot on the Sun's disk. Since Phobos orbits in a low-inclination equatorial orbit, there is a seasonal variation in the latitude of the position of Phobos's shadow projected onto the Martian surface, cycling from far north to far south and back again. At any given fixed geographical location on Mars, there are two intervals per Martian year when the shadow is passing through its latitude and about half a dozen transits of Phobos can be observed at that geographical location over a couple of weeks during each such interval. The situation is similar for Deimos, except only zero or one transits occur during such an interval. It is easy to see that the shadow always falls on the "winter hemisphere", except when it crosses the equator during the vernal and the autumnal equinoxes. Thus transits of Phobos and Deimos happen during Martian autumn and winter in the northern hemisphere and the southern hemisphere. Close to the equator they tend to happen around the autumnal equinox and the vernal equinox; farther from the equator they tend to happen closer to the winter solstice. In either case, the two intervals when transits can take place occur more or less symmetrically before and after the winter solstice (however, the large eccentricity of Mars's orbit prevents true symmetry). Observers on Mars can also view lunar eclipses of Phobos and Deimos. Phobos spends about an hour in Mars's shadow; for Deimos it is about two hours. Surprisingly, despite its orbit being nearly in the plane of Mars's equator and despite its very close distance to Mars, there are some occasions when Phobos escapes being eclipsed. Phobos and Deimos both have synchronous rotation, which means that they have a "far side" that observers on the surface of Mars can't see. The phenomenon of libration occurs for Phobos as it does for Earth's Moon, despite the low inclination and eccentricity of Phobos's orbit. Due to the effect of librations and the parallax due to the close distance of Phobos, by observing at high and low latitudes and observing as Phobos is rising and setting, the overall total coverage of Phobos's surface that is visible at one time or another from one location or another on Mars's surface is considerably higher than 50%. The large Stickney crater is visible along one edge of the face of Phobos. It would be easily visible with the naked eye from the surface of Mars.[citation needed] Since Mars has an atmosphere that is relatively transparent at optical wavelengths (just like Earth, albeit much thinner), meteors will occasionally be seen. Meteor showers on Earth occur when the Earth intersects the orbit of a comet, and likewise, Mars also has meteor showers, although these are different from the ones on Earth. The first meteor photographed on Mars (on March 7, 2004, by the Spirit rover) is now believed to have been part of a meteor shower whose parent body was comet 114P/Wiseman-Skiff. Because the radiant was in the constellation Cepheus, this meteor shower could be dubbed the Martian Cepheids. As on Earth, when a meteor is large enough to actually impact with the surface (without burning up completely in the atmosphere), it becomes a meteorite. The first known meteorite discovered on Mars (and the third known meteorite found someplace other than Earth) was Heat Shield Rock. The first and the second ones were found on the Moon by the Apollo missions. On October 19, 2014, Comet Siding Spring passed extremely close to Mars, so close that the coma may have enveloped the planet. Auroras occur on Mars, but they do not occur at the poles as on Earth, because Mars has no planetwide magnetic field. Rather, they occur near magnetic anomalies in Mars's crust, which are remnants from earlier days when Mars did have a magnetic field. Martian auroras are a distinct kind not seen elsewhere in the Solar System. They would probably also be invisible to the human eye, being largely ultraviolet phenomena. The orientation of Mars's axis is such that its north celestial pole is in Cygnus at R.A. 21h 10m 42s Decl. +52° 53.0′ (or more precisely, 317.67669 +52.88378), near the 6th-magnitude star BD +52 2880 (also known as HR 8106, HD 201834, or SAO 33185), which in turn is at R.A. 21h 10m 15.6s Decl. +53° 33′ 48″. The top two stars in the Northern Cross, Sadr and Deneb, point to the north celestial pole of Mars. The pole is about halfway between Deneb and Alpha Cephei, less than 10° from the former, a bit more than the apparent distance between Sadr and Deneb. Because of its proximity to the pole, Deneb never sets in nearly all of Mars's northern hemisphere. Except in areas close to the equator, Deneb permanently circles the North pole. The orientation of Deneb and Sadr would make a useful clock hand for telling sidereal time. Mars's north celestial pole is also only a few degrees away from the galactic plane. Thus the Milky Way, especially rich in the area of Cygnus, is always visible from the northern hemisphere. The South celestial pole is correspondingly found at 9h 10m 42s and −52° 53.0′, which is a couple of degrees from the 2.5-magnitude star Kappa Velorum (which is at 9h 22m 06.85s −55° 00.6′), which could therefore be considered the southern polar star. The star Canopus, second-brightest in the sky, is a circumpolar star for most southern latitudes. The zodiac constellations of Mars's ecliptic are almost the same as those of Earth — after all, the two ecliptic planes only have a mutual inclination of 1.85° — but on Mars, the Sun spends 6 days in the constellation Cetus, leaving and re-entering Pisces as it does so, making a total of 14 zodiacal constellations. The equinoxes and solstices are different as well: for the northern hemisphere, vernal equinox is in Ophiuchus (compared to Pisces on Earth), summer solstice is at the border of Aquarius and Pisces, autumnal equinox is in Taurus, and winter solstice is in Virgo. As on Earth, precession will cause the solstices and equinoxes to cycle through the zodiac constellations over thousands and tens of thousands of years. As on Earth, the effect of precession causes the north and south celestial poles to move in a very large circle, but on Mars the cycle is 95,500 Martian years (179,600 Earth years) rather than 26,000 years as on Earth. As on Earth, there is a second form of precession: the point of perihelion in Mars's orbit changes slowly, causing the anomalistic year to differ from the sidereal year. However, on Mars, this cycle is 43,000 Martian years (81,000 Earth years) rather than 112,000 years as on Earth. On both Earth and Mars, these two precessions are in opposite directions, and therefore add, to make the precession cycle between the tropical and anomalistic years 21,000 years on Earth and 29,700 Martian years (55,900 Earth years) on Mars. As on Earth, the period of rotation of Mars (the length of its day) is slowing down. However, this effect is three orders of magnitude smaller than on Earth because the gravitational effect of Phobos is negligible and the effect is mainly due to the Sun. On Earth, the gravitational influence of the Moon has a much greater effect. Eventually, in the far future, the length of a day on Earth will equal and then exceed the length of a day on Mars. As on Earth, Mars experiences Milankovitch cycles that cause its axial tilt (obliquity) and orbital eccentricity to vary over long periods of time, which has long-term effects on its climate. The variation of Mars's axial tilt is much larger than for Earth because it lacks the stabilizing influence of a large moon like Earth's Moon. Mars has a 124,000-year obliquity cycle compared to 41,000 years for Earth. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Portal:Outer_space] | [TOKENS: 986] |
Portal:Outer space Introduction Outer space, or simply space, is the expanse that exists beyond Earth's atmosphere and between celestial bodies. It contains ultra-low levels of particle densities, constituting a near-perfect vacuum of predominantly hydrogen and helium plasma, permeated by electromagnetic radiation, cosmic rays, neutrinos, magnetic fields and dust. The baseline temperature of outer space, as set by the background radiation from the Big Bang, is 2.7 kelvins (−270 °C; −455 °F). The plasma between galaxies is thought to account for about half of the baryonic (ordinary) matter in the universe, having a number density of less than one hydrogen atom per cubic metre and a kinetic temperature of millions of kelvins. Local concentrations of matter have condensed into stars and galaxies. Intergalactic space takes up most of the volume of the universe, but even galaxies and star systems consist almost entirely of empty space. Most of the remaining mass-energy in the observable universe is made up of an unknown form, dubbed dark matter and dark energy. Outer space does not begin at a definite altitude above Earth's surface. The Kármán line, an altitude of 100 km (62 mi) above sea level, is conventionally used as the start of outer space in space treaties and for aerospace records keeping. Certain portions of the upper stratosphere and the mesosphere are sometimes referred to as "near space". The framework for international space law was established by the Outer Space Treaty, which entered into force on 10 October 1967. This treaty precludes any claims of national sovereignty and permits all states to freely explore outer space. Despite the drafting of UN resolutions for the peaceful uses of outer space, anti-satellite weapons have been tested in Earth orbit. The concept that the space between the Earth and the Moon must be a vacuum was first proposed in the 17th century after scientists discovered that air pressure decreased with altitude. The immense scale of outer space was grasped in the 20th century when the distance to the Andromeda Galaxy was first measured. Humans began the physical exploration of space later in the same century with the advent of high-altitude balloon flights. This was followed by crewed rocket flights and, then, crewed Earth orbit, first achieved by Yuri Gagarin of the Soviet Union in 1961. The economic cost of putting objects, including humans, into space is very high, limiting human spaceflight to low Earth orbit and the Moon. On the other hand, uncrewed spacecraft have reached all of the known planets in the Solar System. Outer space represents a challenging environment for human exploration because of the hazards of vacuum and radiation. Microgravity has a negative effect on human physiology that causes both muscle atrophy and bone loss. (Full article...) Selected article Io is the innermost of the four Galilean moons of the planet Jupiter and, with a diameter of 3,642 kilometres (2,263 mi), the fourth-largest moon in the Solar System. It was named after the mythological character of Io, a priestess of Hera who became one of the lovers of Zeus. With over 400 active volcanoes, Io is the most geologically active object in the Solar System. This extreme geologic activity is the result of tidal heating from friction generated within Io's interior as it is pulled between Jupiter and the other Galilean satellites—Europa, Ganymede and Callisto. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as 500 km (300 mi) above the surface. Io's surface is also dotted with more than 100 mountains that have been uplifted by extensive compression at the base of the moon's silicate crust. Some of these peaks are taller than Earth's Mount Everest. Unlike most satellites in the outer Solar System, which are mostly composed of water-ice, Io is primarily composed of silicate rock surrounding a molten iron or iron sulfide core. Most of Io's surface is characterized by extensive plains coated with sulfur and sulfur dioxide frost. Io's volcanism is responsible for many of the satellite's unique features. Its volcanic plumes and lava flows produce large surface changes and paint the surface in various shades of yellow, red, white, black, and green, largely due to allotropes and compounds of sulfur. Numerous extensive lava flows, several more than 500 km (300 mi) in length, also mark the surface. The materials produced by this volcanism provide material for Io's thin, patchy atmosphere and Jupiter's extensive magnetosphere. Io's volcanic ejecta also produce a large plasma torus around Jupiter. Read more Selected picture Space-related portals General images Did you know (auto-generated) Space news Upcoming spaceflight launches Astronomical events Topics Categories Wikimedia The following Wikimedia Foundation sister projects provide more on this subject: |
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[SOURCE: https://en.wikipedia.org/wiki/OpenAI#cite_ref-242] | [TOKENS: 8773] |
Contents OpenAI OpenAI is an American artificial intelligence research organization comprising both a non-profit foundation and a controlled for-profit public benefit corporation (PBC), headquartered in San Francisco. It aims to develop "safe and beneficial" artificial general intelligence (AGI), which it defines as "highly autonomous systems that outperform humans at most economically valuable work". OpenAI is widely recognized for its development of the GPT family of large language models, the DALL-E series of text-to-image models, and the Sora series of text-to-video models, which have influenced industry research and commercial applications. Its release of ChatGPT in November 2022 has been credited with catalyzing widespread interest in generative AI. The organization was founded in 2015 in Delaware but evolved a complex corporate structure. As of October 2025, following restructuring approved by California and Delaware regulators, the non-profit OpenAI Foundation holds 26% of the for-profit OpenAI Group PBC, with Microsoft holding 27% and employees/other investors holding 47%. Under its governance arrangements, the OpenAI Foundation holds the authority to appoint the board of the for-profit OpenAI Group PBC, a mechanism designed to align the entity’s strategic direction with the Foundation’s charter. Microsoft previously invested over $13 billion into OpenAI, and provides Azure cloud computing resources. In October 2025, OpenAI conducted a $6.6 billion share sale that valued the company at $500 billion. In 2023 and 2024, OpenAI faced multiple lawsuits for alleged copyright infringement against authors and media companies whose work was used to train some of OpenAI's products. In November 2023, OpenAI's board removed Sam Altman as CEO, citing a lack of confidence in him, but reinstated him five days later following a reconstruction of the board. Throughout 2024, roughly half of then-employed AI safety researchers left OpenAI, citing the company's prominent role in an industry-wide problem. Founding In December 2015, OpenAI was founded as a not for profit organization by Sam Altman, Elon Musk, Ilya Sutskever, Greg Brockman, Trevor Blackwell, Vicki Cheung, Andrej Karpathy, Durk Kingma, John Schulman, Pamela Vagata, and Wojciech Zaremba, with Sam Altman and Elon Musk as the co-chairs. A total of $1 billion in capital was pledged by Sam Altman, Greg Brockman, Elon Musk, Reid Hoffman, Jessica Livingston, Peter Thiel, Amazon Web Services (AWS), and Infosys. However, the actual capital collected significantly lagged pledges. According to company disclosures, only $130 million had been received by 2019. In its founding charter, OpenAI stated an intention to collaborate openly with other institutions by making certain patents and research publicly available, but later restricted access to its most capable models, citing competitive and safety concerns. OpenAI was initially run from Brockman's living room. It was later headquartered at the Pioneer Building in the Mission District, San Francisco. According to OpenAI's charter, its founding mission is "to ensure that artificial general intelligence (AGI)—by which we mean highly autonomous systems that outperform humans at most economically valuable work—benefits all of humanity." Musk and Altman stated in 2015 that they were partly motivated by concerns about AI safety and existential risk from artificial general intelligence. OpenAI stated that "it's hard to fathom how much human-level AI could benefit society", and that it is equally difficult to comprehend "how much it could damage society if built or used incorrectly". The startup also wrote that AI "should be an extension of individual human wills and, in the spirit of liberty, as broadly and evenly distributed as possible", and that "because of AI's surprising history, it's hard to predict when human-level AI might come within reach. When it does, it'll be important to have a leading research institution which can prioritize a good outcome for all over its own self-interest." Co-chair Sam Altman expected a decades-long project that eventually surpasses human intelligence. Brockman met with Yoshua Bengio, one of the "founding fathers" of deep learning, and drew up a list of great AI researchers. Brockman was able to hire nine of them as the first employees in December 2015. OpenAI did not pay AI researchers salaries comparable to those of Facebook or Google. It also did not pay stock options which AI researchers typically get. Nevertheless, OpenAI spent $7 million on its first 52 employees in 2016. OpenAI's potential and mission drew these researchers to the firm; a Google employee said he was willing to leave Google for OpenAI "partly because of the very strong group of people and, to a very large extent, because of its mission." OpenAI co-founder Wojciech Zaremba stated that he turned down "borderline crazy" offers of two to three times his market value to join OpenAI instead. In April 2016, OpenAI released a public beta of "OpenAI Gym", its platform for reinforcement learning research. Nvidia gifted its first DGX-1 supercomputer to OpenAI in August 2016 to help it train larger and more complex AI models with the capability of reducing processing time from six days to two hours. In December 2016, OpenAI released "Universe", a software platform for measuring and training an AI's general intelligence across the world's supply of games, websites, and other applications. Corporate structure In 2019, OpenAI transitioned from non-profit to "capped" for-profit, with the profit being capped at 100 times any investment. According to OpenAI, the capped-profit model allows OpenAI Global, LLC to legally attract investment from venture funds and, in addition, to grant employees stakes in the company. Many top researchers work for Google Brain, DeepMind, or Facebook, which offer equity that a nonprofit would be unable to match. Before the transition, OpenAI was legally required to publicly disclose the compensation of its top employees. The company then distributed equity to its employees and partnered with Microsoft, announcing an investment package of $1 billion into the company. Since then, OpenAI systems have run on an Azure-based supercomputing platform from Microsoft. OpenAI Global, LLC then announced its intention to commercially license its technologies. It planned to spend $1 billion "within five years, and possibly much faster". Altman stated that even a billion dollars may turn out to be insufficient, and that the lab may ultimately need "more capital than any non-profit has ever raised" to achieve artificial general intelligence. The nonprofit, OpenAI, Inc., is the sole controlling shareholder of OpenAI Global, LLC, which, despite being a for-profit company, retains a formal fiduciary responsibility to OpenAI, Inc.'s nonprofit charter. A majority of OpenAI, Inc.'s board is barred from having financial stakes in OpenAI Global, LLC. In addition, minority members with a stake in OpenAI Global, LLC are barred from certain votes due to conflict of interest. Some researchers have argued that OpenAI Global, LLC's switch to for-profit status is inconsistent with OpenAI's claims to be "democratizing" AI. On February 29, 2024, Elon Musk filed a lawsuit against OpenAI and CEO Sam Altman, accusing them of shifting focus from public benefit to profit maximization—a case OpenAI dismissed as "incoherent" and "frivolous," though Musk later revived legal action against Altman and others in August. On April 9, 2024, OpenAI countersued Musk in federal court, alleging that he had engaged in "bad-faith tactics" to slow the company's progress and seize its innovations for his personal benefit. OpenAI also argued that Musk had previously supported the creation of a for-profit structure and had expressed interest in controlling OpenAI himself. The countersuit seeks damages and legal measures to prevent further alleged interference. On February 10, 2025, a consortium of investors led by Elon Musk submitted a $97.4 billion unsolicited bid to buy the nonprofit that controls OpenAI, declaring willingness to match or exceed any better offer. The offer was rejected on 14 February 2025, with OpenAI stating that it was not for sale, but the offer complicated Altman's restructuring plan by suggesting a lower bar for how much the nonprofit should be valued. OpenAI, Inc. was originally designed as a nonprofit in order to ensure that AGI "benefits all of humanity" rather than "the private gain of any person". In 2019, it created OpenAI Global, LLC, a capped-profit subsidiary controlled by the nonprofit. In December 2024, OpenAI proposed a restructuring plan to convert the capped-profit into a Delaware-based public benefit corporation (PBC), and to release it from the control of the nonprofit. The nonprofit would sell its control and other assets, getting equity in return, and would use it to fund and pursue separate charitable projects, including in science and education. OpenAI's leadership described the change as necessary to secure additional investments, and claimed that the nonprofit's founding mission to ensure AGI "benefits all of humanity" would be better fulfilled. The plan has been criticized by former employees. A legal letter named "Not For Private Gain" asked the attorneys general of California and Delaware to intervene, stating that the restructuring is illegal and would remove governance safeguards from the nonprofit and the attorneys general. The letter argues that OpenAI's complex structure was deliberately designed to remain accountable to its mission, without the conflicting pressure of maximizing profits. It contends that the nonprofit is best positioned to advance its mission of ensuring AGI benefits all of humanity by continuing to control OpenAI Global, LLC, whatever the amount of equity that it could get in exchange. PBCs can choose how they balance their mission with profit-making. Controlling shareholders have a large influence on how closely a PBC sticks to its mission. On October 28, 2025, OpenAI announced that it had adopted the new PBC corporate structure after receiving approval from the attorneys general of California and Delaware. Under the new structure, OpenAI's for-profit branch became a public benefit corporation known as OpenAI Group PBC, while the non-profit was renamed to the OpenAI Foundation. The OpenAI Foundation holds a 26% stake in the PBC, while Microsoft holds a 27% stake and the remaining 47% is owned by employees and other investors. All members of the OpenAI Group PBC board of directors will be appointed by the OpenAI Foundation, which can remove them at any time. Members of the Foundation's board will also serve on the for-profit board. The new structure allows the for-profit PBC to raise investor funds like most traditional tech companies, including through an initial public offering, which Altman claimed was the most likely path forward. In January 2023, OpenAI Global, LLC was in talks for funding that would value the company at $29 billion, double its 2021 value. On January 23, 2023, Microsoft announced a new US$10 billion investment in OpenAI Global, LLC over multiple years, partially needed to use Microsoft's cloud-computing service Azure. From September to December, 2023, Microsoft rebranded all variants of its Copilot to Microsoft Copilot, and they added MS-Copilot to many installations of Windows and released Microsoft Copilot mobile apps. Following OpenAI's 2025 restructuring, Microsoft owns a 27% stake in the for-profit OpenAI Group PBC, valued at $135 billion. In a deal announced the same day, OpenAI agreed to purchase $250 billion of Azure services, with Microsoft ceding their right of first refusal over OpenAI's future cloud computing purchases. As part of the deal, OpenAI will continue to share 20% of its revenue with Microsoft until it achieves AGI, which must now be verified by an independent panel of experts. The deal also loosened restrictions on both companies working with third parties, allowing Microsoft to pursue AGI independently and allowing OpenAI to develop products with other companies. In 2017, OpenAI spent $7.9 million, a quarter of its functional expenses, on cloud computing alone. In comparison, DeepMind's total expenses in 2017 were $442 million. In the summer of 2018, training OpenAI's Dota 2 bots required renting 128,000 CPUs and 256 GPUs from Google for multiple weeks. In October 2024, OpenAI completed a $6.6 billion capital raise with a $157 billion valuation including investments from Microsoft, Nvidia, and SoftBank. On January 21, 2025, Donald Trump announced The Stargate Project, a joint venture between OpenAI, Oracle, SoftBank and MGX to build an AI infrastructure system in conjunction with the US government. The project takes its name from OpenAI's existing "Stargate" supercomputer project and is estimated to cost $500 billion. The partners planned to fund the project over the next four years. In July, the United States Department of Defense announced that OpenAI had received a $200 million contract for AI in the military, along with Anthropic, Google, and xAI. In the same month, the company made a deal with the UK Government to use ChatGPT and other AI tools in public services. OpenAI subsequently began a $50 million fund to support nonprofit and community organizations. In April 2025, OpenAI raised $40 billion at a $300 billion post-money valuation, which was the highest-value private technology deal in history. The financing round was led by SoftBank, with other participants including Microsoft, Coatue, Altimeter and Thrive. In July 2025, the company reported annualized revenue of $12 billion. This was an increase from $3.7 billion in 2024, which was driven by ChatGPT subscriptions, which reached 20 million paid subscribers by April 2025, up from 15.5 million at the end of 2024, alongside a rapidly expanding enterprise customer base that grew to five million business users. The company’s cash burn remains high because of the intensive computational costs required to train and operate large language models. It projects an $8 billion operating loss in 2025. OpenAI reports revised long-term spending projections totaling approximately $115 billion through 2029, with annual expenditures projected to escalate significantly, reaching $17 billion in 2026, $35 billion in 2027, and $45 billion in 2028. These expenditures are primarily allocated toward expanding compute infrastructure, developing proprietary AI chips, constructing data centers, and funding intensive model training programs, with more than half of the spending through the end of the decade expected to support research-intensive compute for model training and development. The company's financial strategy prioritizes market expansion and technological advancement over near-term profitability, with OpenAI targeting cash-flow-positive operations by 2029 and projecting revenue of approximately $200 billion by 2030. This aggressive spending trajectory underscores both the enormous capital requirements of scaling cutting-edge AI technology and OpenAI's commitment to maintaining its position as a leader in the artificial intelligence industry. In October 2025, OpenAI completed an employee share sale of up to $10 billion to existing investors which valued the company at $500 billion. The deal values OpenAI as the most valuable privately owned company in the world—surpassing SpaceX as the world's most valuable private company. On November 17, 2023, Sam Altman was removed as CEO when its board of directors (composed of Helen Toner, Ilya Sutskever, Adam D'Angelo and Tasha McCauley) cited a lack of confidence in him. Chief Technology Officer Mira Murati took over as interim CEO. Greg Brockman, the president of OpenAI, was also removed as chairman of the board and resigned from the company's presidency shortly thereafter. Three senior OpenAI researchers subsequently resigned: director of research and GPT-4 lead Jakub Pachocki, head of AI risk Aleksander Mądry, and researcher Szymon Sidor. On November 18, 2023, there were reportedly talks of Altman returning as CEO amid pressure placed upon the board by investors such as Microsoft and Thrive Capital, who objected to Altman's departure. Although Altman himself spoke in favor of returning to OpenAI, he has since stated that he considered starting a new company and bringing former OpenAI employees with him if talks to reinstate him didn't work out. The board members agreed "in principle" to resign if Altman returned. On November 19, 2023, negotiations with Altman to return failed and Murati was replaced by Emmett Shear as interim CEO. The board initially contacted Anthropic CEO Dario Amodei (a former OpenAI executive) about replacing Altman, and proposed a merger of the two companies, but both offers were declined. On November 20, 2023, Microsoft CEO Satya Nadella announced Altman and Brockman would be joining Microsoft to lead a new advanced AI research team, but added that they were still committed to OpenAI despite recent events. Before the partnership with Microsoft was finalized, Altman gave the board another opportunity to negotiate with him. About 738 of OpenAI's 770 employees, including Murati and Sutskever, signed an open letter stating they would quit their jobs and join Microsoft if the board did not rehire Altman and then resign. This prompted OpenAI investors to consider legal action against the board as well. In response, OpenAI management sent an internal memo to employees stating that negotiations with Altman and the board had resumed and would take some time. On November 21, 2023, after continued negotiations, Altman and Brockman returned to the company in their prior roles along with a reconstructed board made up of new members Bret Taylor (as chairman) and Lawrence Summers, with D'Angelo remaining. According to subsequent reporting, shortly before Altman’s firing, some employees raised concerns to the board about how he had handled the safety implications of a recent internal AI capability discovery. On November 29, 2023, OpenAI announced that an anonymous Microsoft employee had joined the board as a non-voting member to observe the company's operations; Microsoft resigned from the board in July 2024. In February 2024, the Securities and Exchange Commission subpoenaed OpenAI's internal communication to determine if Altman's alleged lack of candor misled investors. In 2024, following the temporary removal of Sam Altman and his return, many employees gradually left OpenAI, including most of the original leadership team and a significant number of AI safety researchers. In August 2023, it was announced that OpenAI had acquired the New York-based start-up Global Illumination, a company that deploys AI to develop digital infrastructure and creative tools. In June 2024, OpenAI acquired Multi, a startup focused on remote collaboration. In March 2025, OpenAI reached a deal with CoreWeave to acquire $350 million worth of CoreWeave shares and access to AI infrastructure, in return for $11.9 billion paid over five years. Microsoft was already CoreWeave's biggest customer in 2024. Alongside their other business dealings, OpenAI and Microsoft were renegotiating the terms of their partnership to facilitate a potential future initial public offering by OpenAI, while ensuring Microsoft's continued access to advanced AI models. On May 21, OpenAI announced the $6.5 billion acquisition of io, an AI hardware start-up founded by former Apple designer Jony Ive in 2024. In September 2025, OpenAI agreed to acquire the product testing startup Statsig for $1.1 billion in an all-stock deal and appointed Statsig's founding CEO Vijaye Raji as OpenAI's chief technology officer of applications. The company also announced development of an AI-driven hiring service designed to rival LinkedIn. OpenAI acquired personal finance app Roi in October 2025. In October 2025, OpenAI acquired Software Applications Incorporated, the developer of Sky, a macOS-based natural language interface designed to operate across desktop applications. The Sky team joined OpenAI, and the company announced plans to integrate Sky’s capabilities into ChatGPT. In December 2025, it was announced OpenAI had agreed to acquire Neptune, an AI tooling startup that helps companies track and manage model training, for an undisclosed amount. In January 2026, it was announced OpenAI had acquired healthcare technology startup Torch for approximately $60 million. The acquisition followed the launch of OpenAI’s ChatGPT Health product and was intended to strengthen the company’s medical data and healthcare artificial intelligence capabilities. OpenAI has been criticized for outsourcing the annotation of data sets to Sama, a company based in San Francisco that employed workers in Kenya. These annotations were used to train an AI model to detect toxicity, which could then be used to moderate toxic content, notably from ChatGPT's training data and outputs. However, these pieces of text usually contained detailed descriptions of various types of violence, including sexual violence. The investigation uncovered that OpenAI began sending snippets of data to Sama as early as November 2021. The four Sama employees interviewed by Time described themselves as mentally scarred. OpenAI paid Sama $12.50 per hour of work, and Sama was redistributing the equivalent of between $1.32 and $2.00 per hour post-tax to its annotators. Sama's spokesperson said that the $12.50 was also covering other implicit costs, among which were infrastructure expenses, quality assurance and management. In 2024, OpenAI began collaborating with Broadcom to design a custom AI chip capable of both training and inference, targeted for mass production in 2026 and to be manufactured by TSMC on a 3 nm process node. This initiative intended to reduce OpenAI's dependence on Nvidia GPUs, which are costly and face high demand in the market. In January 2024, Arizona State University purchased ChatGPT Enterprise in OpenAI's first deal with a university. In June 2024, Apple Inc. signed a contract with OpenAI to integrate ChatGPT features into its products as part of its new Apple Intelligence initiative. In June 2025, OpenAI began renting Google Cloud's Tensor Processing Units (TPUs) to support ChatGPT and related services, marking its first meaningful use of non‑Nvidia AI chips. In September 2025, it was revealed that OpenAI signed a contract with Oracle to purchase $300 billion in computing power over the next five years. In September 2025, OpenAI and NVIDIA announced a memorandum of understanding that included a potential deployment of at least 10 gigawatts of NVIDIA systems and a $100 billion investment from NVIDIA in OpenAI. OpenAI expected the negotiations to be completed within weeks. As of January 2026, this has not been realized, and the two sides are rethinking the future of their partnership. In October 2025, OpenAI announced a multi-billion dollar deal with AMD. OpenAI committed to purchasing six gigawatts worth of AMD chips, starting with the MI450. OpenAI will have the option to buy up to 160 million shares of AMD, about 10% of the company, depending on development, performance and share price targets. In December 2025, Disney said it would make a $1 billion investment in OpenAI, and signed a three-year licensing deal that will let users generate videos using Sora—OpenAI's short-form AI video platform. More than 200 Disney, Marvel, Star Wars and Pixar characters will be available to OpenAI users. In early 2026, Amazon entered advanced discussions to invest up to $50 billion in OpenAI as part of a potential artificial intelligence partnership. Under the proposed agreement, OpenAI’s models could be integrated into Amazon’s digital assistant Alexa and other internal projects. OpenAI provides LLMs to the Artificial Intelligence Cyber Challenge and to the Advanced Research Projects Agency for Health. In October 2024, The Intercept revealed that OpenAI's tools are considered "essential" for AFRICOM's mission and included in an "Exception to Fair Opportunity" contractual agreement between the United States Department of Defense and Microsoft. In December 2024, OpenAI said it would partner with defense-tech company Anduril to build drone defense technologies for the United States and its allies. In 2025, OpenAI's Chief Product Officer, Kevin Weil, was commissioned lieutenant colonel in the U.S. Army to join Detachment 201 as senior advisor. In June 2025, the U.S. Department of Defense awarded OpenAI a $200 million one-year contract to develop AI tools for military and national security applications. OpenAI announced a new program, OpenAI for Government, to give federal, state, and local governments access to its models, including ChatGPT. Services In February 2019, GPT-2 was announced, which gained attention for its ability to generate human-like text. In 2020, OpenAI announced GPT-3, a language model trained on large internet datasets. GPT-3 is aimed at natural language answering questions, but it can also translate between languages and coherently generate improvised text. It also announced that an associated API, named the API, would form the heart of its first commercial product. Eleven employees left OpenAI, mostly between December 2020 and January 2021, in order to establish Anthropic. In 2021, OpenAI introduced DALL-E, a specialized deep learning model adept at generating complex digital images from textual descriptions, utilizing a variant of the GPT-3 architecture. In December 2022, OpenAI received widespread media coverage after launching a free preview of ChatGPT, its new AI chatbot based on GPT-3.5. According to OpenAI, the preview received over a million signups within the first five days. According to anonymous sources cited by Reuters in December 2022, OpenAI Global, LLC was projecting $200 million of revenue in 2023 and $1 billion in revenue in 2024. After ChatGPT was launched, Google announced a similar chatbot, Bard, amid internal concerns that ChatGPT could threaten Google’s position as a primary source of online information. On February 7, 2023, Microsoft announced that it was building AI technology based on the same foundation as ChatGPT into Microsoft Bing, Edge, Microsoft 365 and other products. On March 14, 2023, OpenAI released GPT-4, both as an API (with a waitlist) and as a feature of ChatGPT Plus. On November 6, 2023, OpenAI launched GPTs, allowing individuals to create customized versions of ChatGPT for specific purposes, further expanding the possibilities of AI applications across various industries. On November 14, 2023, OpenAI announced they temporarily suspended new sign-ups for ChatGPT Plus due to high demand. Access for newer subscribers re-opened a month later on December 13. In December 2024, the company launched the Sora model. It also launched OpenAI o1, an early reasoning model that was internally codenamed strawberry. Additionally, ChatGPT Pro—a $200/month subscription service offering unlimited o1 access and enhanced voice features—was introduced, and preliminary benchmark results for the upcoming OpenAI o3 models were shared. On January 23, 2025, OpenAI released Operator, an AI agent and web automation tool for accessing websites to execute goals defined by users. The feature was only available to Pro users in the United States. OpenAI released deep research agent, nine days later. It scored a 27% accuracy on the benchmark Humanity's Last Exam (HLE). Altman later stated GPT-4.5 would be the last model without full chain-of-thought reasoning. In July 2025, reports indicated that AI models by both OpenAI and Google DeepMind solved mathematics problems at the level of top-performing students in the International Mathematical Olympiad. OpenAI's large language model was able to achieve gold medal-level performance, reflecting significant progress in AI's reasoning abilities. On October 6, 2025, OpenAI unveiled its Agent Builder platform during the company's DevDay event. The platform includes a visual drag-and-drop interface that lets developers and businesses design, test, and deploy agentic workflows with limited coding. On October 21, 2025, OpenAI introduced ChatGPT Atlas, a browser integrating the ChatGPT assistant directly into web navigation, to compete with existing browsers such as Google Chrome and Apple Safari. On December 11, 2025, OpenAI announced GPT-5.2. This model will be better at creating spreadsheets, building presentations, perceiving images, writing code and understanding long context. On January 27, 2026, OpenAI introduced Prism, a LaTeX-native workspace meant to assist scientists to help with research and writing. The platform utilizes GPT-5.2 as a backend to automate the process of drafting for scientific papers, including features for managing citations, complex equation formatting, and real-time collaborative editing. In March 2023, the company was criticized for disclosing particularly few technical details about products like GPT-4, contradicting its initial commitment to openness and making it harder for independent researchers to replicate its work and develop safeguards. OpenAI cited competitiveness and safety concerns to justify this repudiation. OpenAI's former chief scientist Ilya Sutskever argued in 2023 that open-sourcing increasingly capable models was increasingly risky, and that the safety reasons for not open-sourcing the most potent AI models would become "obvious" in a few years. In September 2025, OpenAI published a study on how people use ChatGPT for everyday tasks. The study found that "non-work tasks" (according to an LLM-based classifier) account for more than 72 percent of all ChatGPT usage, with a minority of overall usage related to business productivity. In July 2023, OpenAI launched the superalignment project, aiming within four years to determine how to align future superintelligent systems. OpenAI promised to dedicate 20% of its computing resources to the project, although the team denied receiving anything close to 20%. OpenAI ended the project in May 2024 after its co-leaders Ilya Sutskever and Jan Leike left the company. In August 2025, OpenAI was criticized after thousands of private ChatGPT conversations were inadvertently exposed to public search engines like Google due to an experimental "share with search engines" feature. The opt-in toggle, intended to allow users to make specific chats discoverable, resulted in some discussions including personal details such as names, locations, and intimate topics appearing in search results when users accidentally enabled it while sharing links. OpenAI announced the feature's permanent removal on August 1, 2025, and the company began coordinating with search providers to remove the exposed content, emphasizing that it was not a security breach but a design flaw that heightened privacy risks. CEO Sam Altman acknowledged the issue in a podcast, noting users often treat ChatGPT as a confidant for deeply personal matters, which amplified concerns about AI handling sensitive data. Management In 2018, Musk resigned from his Board of Directors seat, citing "a potential future conflict [of interest]" with his role as CEO of Tesla due to Tesla's AI development for self-driving cars. OpenAI stated that Musk's financial contributions were below $45 million. On March 3, 2023, Reid Hoffman resigned from his board seat, citing a desire to avoid conflicts of interest with his investments in AI companies via Greylock Partners, and his co-founding of the AI startup Inflection AI. Hoffman remained on the board of Microsoft, a major investor in OpenAI. In May 2024, Chief Scientist Ilya Sutskever resigned and was succeeded by Jakub Pachocki. Co-leader Jan Leike also departed amid concerns over safety and trust. OpenAI then signed deals with Reddit, News Corp, Axios, and Vox Media. Paul Nakasone then joined the board of OpenAI. In August 2024, cofounder John Schulman left OpenAI to join Anthropic, and OpenAI's president Greg Brockman took extended leave until November. In September 2024, CTO Mira Murati left the company. In November 2025, Lawrence Summers resigned from the board of directors. Governance and legal issues In May 2023, Sam Altman, Greg Brockman and Ilya Sutskever posted recommendations for the governance of superintelligence. They stated that superintelligence could happen within the next 10 years, allowing a "dramatically more prosperous future" and that "given the possibility of existential risk, we can't just be reactive". They proposed creating an international watchdog organization similar to IAEA to oversee AI systems above a certain capability threshold, suggesting that relatively weak AI systems on the other side should not be overly regulated. They also called for more technical safety research for superintelligences, and asked for more coordination, for example through governments launching a joint project which "many current efforts become part of". In July 2023, the FTC issued a civil investigative demand to OpenAI to investigate whether the company's data security and privacy practices to develop ChatGPT were unfair or harmed consumers (including by reputational harm) in violation of Section 5 of the Federal Trade Commission Act of 1914. These are typically preliminary investigative matters and are nonpublic, but the FTC's document was leaked. In July 2023, the FTC launched an investigation into OpenAI over allegations that the company scraped public data and published false and defamatory information. They asked OpenAI for comprehensive information about its technology and privacy safeguards, as well as any steps taken to prevent the recurrence of situations in which its chatbot generated false and derogatory content about people. The agency also raised concerns about ‘circular’ spending arrangements—for example, Microsoft extending Azure credits to OpenAI while both companies shared engineering talent—and warned that such structures could negatively affect the public. In September 2024, OpenAI's global affairs chief endorsed the UK's "smart" AI regulation during testimony to a House of Lords committee. In February 2025, OpenAI CEO Sam Altman stated that the company is interested in collaborating with the People's Republic of China, despite regulatory restrictions imposed by the U.S. government. This shift comes in response to the growing influence of the Chinese artificial intelligence company DeepSeek, which has disrupted the AI market with open models, including DeepSeek V3 and DeepSeek R1. Following DeepSeek's market emergence, OpenAI enhanced security protocols to protect proprietary development techniques from industrial espionage. Some industry observers noted similarities between DeepSeek's model distillation approach and OpenAI's methodology, though no formal intellectual property claim was filed. According to Oliver Roberts, in March 2025, the United States had 781 state AI bills or laws. OpenAI advocated for preempting state AI laws with federal laws. According to Scott Kohler, OpenAI has opposed California's AI legislation and suggested that the state bill encroaches on a more competent federal government. Public Citizen opposed a federal preemption on AI and pointed to OpenAI's growth and valuation as evidence that existing state laws have not hampered innovation. Before May 2024, OpenAI required departing employees to sign a lifelong non-disparagement agreement forbidding them from criticizing OpenAI and acknowledging the existence of the agreement. Daniel Kokotajlo, a former employee, publicly stated that he forfeited his vested equity in OpenAI in order to leave without signing the agreement. Sam Altman stated that he was unaware of the equity cancellation provision, and that OpenAI never enforced it to cancel any employee's vested equity. However, leaked documents and emails refute this claim. On May 23, 2024, OpenAI sent a memo releasing former employees from the agreement. OpenAI was sued for copyright infringement by authors Sarah Silverman, Matthew Butterick, Paul Tremblay and Mona Awad in July 2023. In September 2023, 17 authors, including George R. R. Martin, John Grisham, Jodi Picoult and Jonathan Franzen, joined the Authors Guild in filing a class action lawsuit against OpenAI, alleging that the company's technology was illegally using their copyrighted work. The New York Times also sued the company in late December 2023. In May 2024 it was revealed that OpenAI had destroyed its Books1 and Books2 training datasets, which were used in the training of GPT-3, and which the Authors Guild believed to have contained over 100,000 copyrighted books. In 2021, OpenAI developed a speech recognition tool called Whisper. OpenAI used it to transcribe more than one million hours of YouTube videos into text for training GPT-4. The automated transcription of YouTube videos raised concerns within OpenAI employees regarding potential violations of YouTube's terms of service, which prohibit the use of videos for applications independent of the platform, as well as any type of automated access to its videos. Despite these concerns, the project proceeded with notable involvement from OpenAI's president, Greg Brockman. The resulting dataset proved instrumental in training GPT-4. In February 2024, The Intercept as well as Raw Story and Alternate Media Inc. filed lawsuit against OpenAI on copyright litigation ground. The lawsuit is said to have charted a new legal strategy for digital-only publishers to sue OpenAI. On April 30, 2024, eight newspapers filed a lawsuit in the Southern District of New York against OpenAI and Microsoft, claiming illegal harvesting of their copyrighted articles. The suing publications included The Mercury News, The Denver Post, The Orange County Register, St. Paul Pioneer Press, Chicago Tribune, Orlando Sentinel, Sun Sentinel, and New York Daily News. In June 2023, a lawsuit claimed that OpenAI scraped 300 billion words online without consent and without registering as a data broker. It was filed in San Francisco, California, by sixteen anonymous plaintiffs. They also claimed that OpenAI and its partner as well as customer Microsoft continued to unlawfully collect and use personal data from millions of consumers worldwide to train artificial intelligence models. On May 22, 2024, OpenAI entered into an agreement with News Corp to integrate news content from The Wall Street Journal, the New York Post, The Times, and The Sunday Times into its AI platform. Meanwhile, other publications like The New York Times chose to sue OpenAI and Microsoft for copyright infringement over the use of their content to train AI models. In November 2024, a coalition of Canadian news outlets, including the Toronto Star, Metroland Media, Postmedia, The Globe and Mail, The Canadian Press and CBC, sued OpenAI for using their news articles to train its software without permission. In October 2024 during a New York Times interview, Suchir Balaji accused OpenAI of violating copyright law in developing its commercial LLMs which he had helped engineer. He was a likely witness in a major copyright trial against the AI company, and was one of several of its current or former employees named in court filings as potentially having documents relevant to the case. On November 26, 2024, Balaji died by suicide. His death prompted the circulation of conspiracy theories alleging that he had been deliberately silenced. California Congressman Ro Khanna endorsed calls for an investigation. On April 24, 2025, Ziff Davis sued OpenAI in Delaware federal court for copyright infringement. Ziff Davis is known for publications such as ZDNet, PCMag, CNET, IGN and Lifehacker. In April 2023, the EU's European Data Protection Board (EDPB) formed a dedicated task force on ChatGPT "to foster cooperation and to exchange information on possible enforcement actions conducted by data protection authorities" based on the "enforcement action undertaken by the Italian data protection authority against OpenAI about the ChatGPT service". In late April 2024 NOYB filed a complaint with the Austrian Datenschutzbehörde against OpenAI for violating the European General Data Protection Regulation. A text created with ChatGPT gave a false date of birth for a living person without giving the individual the option to see the personal data used in the process. A request to correct the mistake was denied. Additionally, neither the recipients of ChatGPT's work nor the sources used, could be made available, OpenAI claimed. OpenAI was criticized for lifting its ban on using ChatGPT for "military and warfare". Up until January 10, 2024, its "usage policies" included a ban on "activity that has high risk of physical harm, including", specifically, "weapons development" and "military and warfare". Its new policies prohibit "[using] our service to harm yourself or others" and to "develop or use weapons". In August 2025, the parents of a 16-year-old boy who died by suicide filed a wrongful death lawsuit against OpenAI (and CEO Sam Altman), alleging that months of conversations with ChatGPT about mental health and methods of self-harm contributed to their son's death and that safeguards were inadequate for minors. OpenAI expressed condolences and said it was strengthening protections (including updated crisis response behavior and parental controls). Coverage described it as a first-of-its-kind wrongful death case targeting the company's chatbot. The complaint was filed in California state court in San Francisco. In November 2025, the Social Media Victims Law Center and Tech Justice Law Project filed seven lawsuits against OpenAI, of which four lawsuits alleged wrongful death. The suits were filed on behalf of Zane Shamblin, 23, of Texas; Amaurie Lacey, 17, of Georgia; Joshua Enneking, 26, of Florida; and Joe Ceccanti, 48, of Oregon, who each committed suicide after prolonged ChatGPT usage. In December 2025, Stein-Erik Soelberg, who was 56 years old at the time, allegedly murdered his mother Suzanne Adams. In the months prior the paranoid, delusional man often discussed his ideas with ChatGPT. Adam's estate then sued OpenAI claiming that the company shared responsibility due to the risk of chatbot psychosis despite the fact that chatbot psychosis is not a real medical diagnosis. OpenAI responded saying they will make ChatGPT safer for users disconnected from reality. See also References Further reading External links |
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Contents Elon Musk Elon Reeve Musk (/ˈiːlɒn/ EE-lon; born June 28, 1971) is a businessman and entrepreneur known for his leadership of Tesla, SpaceX, Twitter, and xAI. Musk has been the wealthiest person in the world since 2025; as of February 2026,[update] Forbes estimates his net worth to be around US$852 billion. Born into a wealthy family in Pretoria, South Africa, Musk emigrated in 1989 to Canada; he has Canadian citizenship since his mother was born there. He received bachelor's degrees in 1997 from the University of Pennsylvania before moving to California to pursue business ventures. In 1995, Musk co-founded the software company Zip2. Following its sale in 1999, he co-founded X.com, an online payment company that later merged to form PayPal, which was acquired by eBay in 2002. Musk also became an American citizen in 2002. In 2002, Musk founded the space technology company SpaceX, becoming its CEO and chief engineer; the company has since led innovations in reusable rockets and commercial spaceflight. Musk joined the automaker Tesla as an early investor in 2004 and became its CEO and product architect in 2008; it has since become a leader in electric vehicles. In 2015, he co-founded OpenAI to advance artificial intelligence (AI) research, but later left; growing discontent with the organization's direction and their leadership in the AI boom in the 2020s led him to establish xAI, which became a subsidiary of SpaceX in 2026. In 2022, he acquired the social network Twitter, implementing significant changes, and rebranding it as X in 2023. His other businesses include the neurotechnology company Neuralink, which he co-founded in 2016, and the tunneling company the Boring Company, which he founded in 2017. In November 2025, a Tesla pay package worth $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Musk was the largest donor in the 2024 U.S. presidential election, where he supported Donald Trump. After Trump was inaugurated as president in early 2025, Musk served as Senior Advisor to the President and as the de facto head of the Department of Government Efficiency (DOGE). After a public feud with Trump, Musk left the Trump administration and returned to managing his companies. Musk is a supporter of global far-right figures, causes, and political parties. His political activities, views, and statements have made him a polarizing figure. Musk has been criticized for COVID-19 misinformation, promoting conspiracy theories, and affirming antisemitic, racist, and transphobic comments. His acquisition of Twitter was controversial due to a subsequent increase in hate speech and the spread of misinformation on the service, following his pledge to decrease censorship. His role in the second Trump administration attracted public backlash, particularly in response to DOGE. The emails he sent to Jeffrey Epstein are included in the Epstein files, which were published between 2025–26 and became a topic of worldwide debate. Early life Elon Reeve Musk was born on June 28, 1971, in Pretoria, South Africa's administrative capital. He is of British and Pennsylvania Dutch ancestry. His mother, Maye (née Haldeman), is a model and dietitian born in Saskatchewan, Canada, and raised in South Africa. Musk therefore holds both South African and Canadian citizenship from birth. His father, Errol Musk, is a South African electromechanical engineer, pilot, sailor, consultant, emerald dealer, and property developer, who partly owned a rental lodge at Timbavati Private Nature Reserve. His maternal grandfather, Joshua N. Haldeman, who died in a plane crash when Elon was a toddler, was an American-born Canadian chiropractor, aviator and political activist in the technocracy movement who moved to South Africa in 1950. Elon has a younger brother, Kimbal, a younger sister, Tosca, and four paternal half-siblings. Musk was baptized as a child in the Anglican Church of Southern Africa. Despite both Elon and Errol previously stating that Errol was a part owner of a Zambian emerald mine, in 2023, Errol recounted that the deal he made was to receive "a portion of the emeralds produced at three small mines". Errol was elected to the Pretoria City Council as a representative of the anti-apartheid Progressive Party and has said that his children shared their father's dislike of apartheid. After his parents divorced in 1979, Elon, aged around 9, chose to live with his father because Errol Musk had an Encyclopædia Britannica and a computer. Elon later regretted his decision and became estranged from his father. Elon has recounted trips to a wilderness school that he described as a "paramilitary Lord of the Flies" where "bullying was a virtue" and children were encouraged to fight over rations. In one incident, after an altercation with a fellow pupil, Elon was thrown down concrete steps and beaten severely, leading to him being hospitalized for his injuries. Elon described his father berating him after he was discharged from the hospital. Errol denied berating Elon and claimed, "The [other] boy had just lost his father to suicide, and Elon had called him stupid. Elon had a tendency to call people stupid. How could I possibly blame that child?" Elon was an enthusiastic reader of books, and had attributed his success in part to having read The Lord of the Rings, the Foundation series, and The Hitchhiker's Guide to the Galaxy. At age ten, he developed an interest in computing and video games, teaching himself how to program from the VIC-20 user manual. At age twelve, Elon sold his BASIC-based game Blastar to PC and Office Technology magazine for approximately $500 (equivalent to $1,600 in 2025). Musk attended Waterkloof House Preparatory School, Bryanston High School, and then Pretoria Boys High School, where he graduated. Musk was a decent but unexceptional student, earning a 61/100 in Afrikaans and a B on his senior math certification. Musk applied for a Canadian passport through his Canadian-born mother to avoid South Africa's mandatory military service, which would have forced him to participate in the apartheid regime, as well as to ease his path to immigration to the United States. While waiting for his application to be processed, he attended the University of Pretoria for five months. Musk arrived in Canada in June 1989, connected with a second cousin in Saskatchewan, and worked odd jobs, including at a farm and a lumber mill. In 1990, he entered Queen's University in Kingston, Ontario. Two years later, he transferred to the University of Pennsylvania, where he studied until 1995. Although Musk has said that he earned his degrees in 1995, the University of Pennsylvania did not award them until 1997 – a Bachelor of Arts in physics and a Bachelor of Science in economics from the university's Wharton School. He reportedly hosted large, ticketed house parties to help pay for tuition, and wrote a business plan for an electronic book-scanning service similar to Google Books. In 1994, Musk held two internships in Silicon Valley: one at energy storage startup Pinnacle Research Institute, which investigated electrolytic supercapacitors for energy storage, and another at Palo Alto–based startup Rocket Science Games. In 1995, he was accepted to a graduate program in materials science at Stanford University, but did not enroll. Musk decided to join the Internet boom of the 1990s, applying for a job at Netscape, to which he reportedly never received a response. The Washington Post reported that Musk lacked legal authorization to remain and work in the United States after failing to enroll at Stanford. In response, Musk said he was allowed to work at that time and that his student visa transitioned to an H1-B. According to numerous former business associates and shareholders, Musk said he was on a student visa at the time. Business career In 1995, Musk, his brother Kimbal, and Greg Kouri founded the web software company Zip2 with funding from a group of angel investors. They housed the venture at a small rented office in Palo Alto. Replying to Rolling Stone, Musk denounced the notion that they started their company with funds borrowed from Errol Musk, but in a tweet, he recognized that his father contributed 10% of a later funding round. The company developed and marketed an Internet city guide for the newspaper publishing industry, with maps, directions, and yellow pages. According to Musk, "The website was up during the day and I was coding it at night, seven days a week, all the time." To impress investors, Musk built a large plastic structure around a standard computer to create the impression that Zip2 was powered by a small supercomputer. The Musk brothers obtained contracts with The New York Times and the Chicago Tribune, and persuaded the board of directors to abandon plans for a merger with CitySearch. Musk's attempts to become CEO were thwarted by the board. Compaq acquired Zip2 for $307 million in cash in February 1999 (equivalent to $590,000,000 in 2025), and Musk received $22 million (equivalent to $43,000,000 in 2025) for his 7-percent share. In 1999, Musk co-founded X.com, an online financial services and e-mail payment company. The startup was one of the first federally insured online banks, and, in its initial months of operation, over 200,000 customers joined the service. The company's investors regarded Musk as inexperienced and replaced him with Intuit CEO Bill Harris by the end of the year. The following year, X.com merged with online bank Confinity to avoid competition. Founded by Max Levchin and Peter Thiel, Confinity had its own money-transfer service, PayPal, which was more popular than X.com's service. Within the merged company, Musk returned as CEO. Musk's preference for Microsoft software over Unix created a rift in the company and caused Thiel to resign. Due to resulting technological issues and lack of a cohesive business model, the board ousted Musk and replaced him with Thiel in 2000.[b] Under Thiel, the company focused on the PayPal service and was renamed PayPal in 2001. In 2002, PayPal was acquired by eBay for $1.5 billion (equivalent to $2,700,000,000 in 2025) in stock, of which Musk—the largest shareholder with 11.72% of shares—received $175.8 million (equivalent to $320,000,000 in 2025). In 2017, Musk purchased the domain X.com from PayPal for an undisclosed amount, stating that it had sentimental value. In 2001, Musk became involved with the nonprofit Mars Society and discussed funding plans to place a growth-chamber for plants on Mars. Seeking a way to launch the greenhouse payloads into space, Musk made two unsuccessful trips to Moscow to purchase intercontinental ballistic missiles (ICBMs) from Russian companies NPO Lavochkin and Kosmotras. Musk instead decided to start a company to build affordable rockets. With $100 million of his early fortune, (equivalent to $180,000,000 in 2025) Musk founded SpaceX in May 2002 and became the company's CEO and Chief Engineer. SpaceX attempted its first launch of the Falcon 1 rocket in 2006. Although the rocket failed to reach Earth orbit, it was awarded a Commercial Orbital Transportation Services program contract from NASA, then led by Mike Griffin. After two more failed attempts that nearly caused Musk to go bankrupt, SpaceX succeeded in launching the Falcon 1 into orbit in 2008. Later that year, SpaceX received a $1.6 billion NASA contract (equivalent to $2,400,000,000 in 2025) for Falcon 9-launched Dragon spacecraft flights to the International Space Station (ISS), replacing the Space Shuttle after its 2011 retirement. In 2012, the Dragon vehicle docked with the ISS, a first for a commercial spacecraft. Working towards its goal of reusable rockets, in 2015 SpaceX successfully landed the first stage of a Falcon 9 on a land platform. Later landings were achieved on autonomous spaceport drone ships, an ocean-based recovery platform. In 2018, SpaceX launched the Falcon Heavy; the inaugural mission carried Musk's personal Tesla Roadster as a dummy payload. Since 2019, SpaceX has been developing Starship, a reusable, super heavy-lift launch vehicle intended to replace the Falcon 9 and Falcon Heavy. In 2020, SpaceX launched its first crewed flight, the Demo-2, becoming the first private company to place astronauts into orbit and dock a crewed spacecraft with the ISS. In 2024, NASA awarded SpaceX an $843 million (equivalent to $865,000,000 in 2025) contract to build a spacecraft that NASA will use to deorbit the ISS at the end of its lifespan. In 2015, SpaceX began development of the Starlink constellation of low Earth orbit satellites to provide satellite Internet access. After the launch of prototype satellites in 2018, the first large constellation was deployed in May 2019. As of May 2025[update], over 7,600 Starlink satellites are operational, comprising 65% of all operational Earth satellites. The total cost of the decade-long project to design, build, and deploy the constellation was estimated by SpaceX in 2020 to be $10 billion (equivalent to $12,000,000,000 in 2025).[c] During the Russian invasion of Ukraine, Musk provided free Starlink service to Ukraine, permitting Internet access and communication at a yearly cost to SpaceX of $400 million (equivalent to $440,000,000 in 2025). However, Musk refused to block Russian state media on Starlink. In 2023, Musk denied Ukraine's request to activate Starlink over Crimea to aid an attack against the Russian navy, citing fears of a nuclear response. Tesla, Inc., originally Tesla Motors, was incorporated in July 2003 by Martin Eberhard and Marc Tarpenning. Both men played active roles in the company's early development prior to Musk's involvement. Musk led the Series A round of investment in February 2004; he invested $6.35 million (equivalent to $11,000,000 in 2025), became the majority shareholder, and joined Tesla's board of directors as chairman. Musk took an active role within the company and oversaw Roadster product design, but was not deeply involved in day-to-day business operations. Following a series of escalating conflicts in 2007 and the 2008 financial crisis, Eberhard was ousted from the firm.[page needed] Musk assumed leadership of the company as CEO and product architect in 2008. A 2009 lawsuit settlement with Eberhard designated Musk as a Tesla co-founder, along with Tarpenning and two others. Tesla began delivery of the Roadster, an electric sports car, in 2008. With sales of about 2,500 vehicles, it was the first mass production all-electric car to use lithium-ion battery cells. Under Musk, Tesla has since launched several well-selling electric vehicles, including the four-door sedan Model S (2012), the crossover Model X (2015), the mass-market sedan Model 3 (2017), the crossover Model Y (2020), and the pickup truck Cybertruck (2023). In May 2020, Musk resigned as chairman of the board as part of the settlement of a lawsuit from the SEC over him tweeting that funding had been "secured" for potentially taking Tesla private. The company has also constructed multiple lithium-ion battery and electric vehicle factories, called Gigafactories. Since its initial public offering in 2010, Tesla stock has risen significantly; it became the most valuable carmaker in summer 2020, and it entered the S&P 500 later that year. In October 2021, it reached a market capitalization of $1 trillion (equivalent to $1,200,000,000,000 in 2025), the sixth company in U.S. history to do so. Musk provided the initial concept and financial capital for SolarCity, which his cousins Lyndon and Peter Rive founded in 2006. By 2013, SolarCity was the second largest provider of solar power systems in the United States. In 2014, Musk promoted the idea of SolarCity building an advanced production facility in Buffalo, New York, triple the size of the largest solar plant in the United States. Construction of the factory started in 2014 and was completed in 2017. It operated as a joint venture with Panasonic until early 2020. Tesla acquired SolarCity for $2 billion in 2016 (equivalent to $2,700,000,000 in 2025) and merged it with its battery unit to create Tesla Energy. The deal's announcement resulted in a more than 10% drop in Tesla's stock price; at the time, SolarCity was facing liquidity issues. Multiple shareholder groups filed a lawsuit against Musk and Tesla's directors, stating that the purchase of SolarCity was done solely to benefit Musk and came at the expense of Tesla and its shareholders. Tesla directors settled the lawsuit in January 2020, leaving Musk the sole remaining defendant. Two years later, the court ruled in Musk's favor. In 2016, Musk co-founded Neuralink, a neurotechnology startup, with an investment of $100 million. Neuralink aims to integrate the human brain with artificial intelligence (AI) by creating devices that are embedded in the brain. Such technology could enhance memory or allow the devices to communicate with software. The company also hopes to develop devices to treat neurological conditions like spinal cord injuries. In 2022, Neuralink announced that clinical trials would begin by the end of the year. In September 2023, the Food and Drug Administration approved Neuralink to initiate six-year human trials. Neuralink has conducted animal testing on macaques at the University of California, Davis. In 2021, the company released a video in which a macaque played the video game Pong via a Neuralink implant. The company's animal trials—which have caused the deaths of some monkeys—have led to claims of animal cruelty. The Physicians Committee for Responsible Medicine has alleged that Neuralink violated the Animal Welfare Act. Employees have complained that pressure from Musk to accelerate development has led to botched experiments and unnecessary animal deaths. In 2022, a federal probe was launched into possible animal welfare violations by Neuralink.[needs update] In 2017, Musk founded the Boring Company to construct tunnels; he also revealed plans for specialized, underground, high-occupancy vehicles that could travel up to 150 miles per hour (240 km/h) and thus circumvent above-ground traffic in major cities. Early in 2017, the company began discussions with regulatory bodies and initiated construction of a 30-foot (9.1 m) wide, 50-foot (15 m) long, and 15-foot (4.6 m) deep "test trench" on the premises of SpaceX's offices, as that required no permits. The Los Angeles tunnel, less than two miles (3.2 km) in length, debuted to journalists in 2018. It used Tesla Model Xs and was reported to be a rough ride while traveling at suboptimal speeds. Two tunnel projects announced in 2018, in Chicago and West Los Angeles, have been canceled. A tunnel beneath the Las Vegas Convention Center was completed in early 2021. Local officials have approved further expansions of the tunnel system. April 14, 2022 In early 2017, Musk expressed interest in buying Twitter and had questioned the platform's commitment to freedom of speech. By 2022, Musk had reached 9.2% stake in the company, making him the largest shareholder.[d] Musk later agreed to a deal that would appoint him to Twitter's board of directors and prohibit him from acquiring more than 14.9% of the company. Days later, Musk made a $43 billion offer to buy Twitter. By the end of April Musk had successfully concluded his bid for approximately $44 billion. This included approximately $12.5 billion in loans and $21 billion in equity financing. Having backtracked on his initial decision, Musk bought the company on October 27, 2022. Immediately after the acquisition, Musk fired several top Twitter executives including CEO Parag Agrawal; Musk became the CEO instead. Under Elon Musk, Twitter instituted monthly subscriptions for a "blue check", and laid off a significant portion of the company's staff. Musk lessened content moderation and hate speech also increased on the platform after his takeover. In late 2022, Musk released internal documents relating to Twitter's moderation of Hunter Biden's laptop controversy in the lead-up to the 2020 presidential election. Musk also promised to step down as CEO after a Twitter poll, and five months later, Musk stepped down as CEO and transitioned his role to executive chairman and chief technology officer (CTO). Despite Musk stepping down as CEO, X continues to struggle with challenges such as viral misinformation, hate speech, and antisemitism controversies. Musk has been accused of trying to silence some of his critics such as Twitch streamer Asmongold, who criticized him during one of his streams. Musk has been accused of removing their accounts' blue checkmarks, which hinders visibility and is considered a form of shadow banning, or suspending their accounts without justification. Other activities In August 2013, Musk announced plans for a version of a vactrain, and assigned engineers from SpaceX and Tesla to design a transport system between Greater Los Angeles and the San Francisco Bay Area, at an estimated cost of $6 billion. Later that year, Musk unveiled the concept, dubbed the Hyperloop, intended to make travel cheaper than any other mode of transport for such long distances. In December 2015, Musk co-founded OpenAI, a not-for-profit artificial intelligence (AI) research company aiming to develop artificial general intelligence, intended to be safe and beneficial to humanity. Musk pledged $1 billion of funding to the company, and initially gave $50 million. In 2018, Musk left the OpenAI board. Since 2018, OpenAI has made significant advances in machine learning. In July 2023, Musk launched the artificial intelligence company xAI, which aims to develop a generative AI program that competes with existing offerings like OpenAI's ChatGPT. Musk obtained funding from investors in SpaceX and Tesla, and xAI hired engineers from Google and OpenAI. December 16, 2022 Musk uses a private jet owned by Falcon Landing LLC, a SpaceX-linked company, and acquired a second jet in August 2020. His heavy use of the jets and the consequent fossil fuel usage have received criticism. Musk's flight usage is tracked on social media through ElonJet. In December 2022, Musk banned the ElonJet account on Twitter, and made temporary bans on the accounts of journalists that posted stories regarding the incident, including Donie O'Sullivan, Keith Olbermann, and journalists from The New York Times, The Washington Post, CNN, and The Intercept. In October 2025, Musk's company xAI launched Grokipedia, an AI-generated online encyclopedia that he promoted as an alternative to Wikipedia. Articles on Grokipedia are generated and reviewed by xAI's Grok chatbot. Media coverage and academic analysis described Grokipedia as frequently reusing Wikipedia content but framing contested political and social topics in line with Musk's own views and right-wing narratives. A study by Cornell University researchers and NBC News stated that Grokipedia cites sources that are blacklisted or considered "generally unreliable" on Wikipedia, for example, the conspiracy site Infowars and the neo-Nazi forum Stormfront. Wired, The Guardian and Time criticized Grokipedia for factual errors and for presenting Musk himself in unusually positive terms while downplaying controversies. Politics Musk is an outlier among business leaders who typically avoid partisan political advocacy. Musk was a registered independent voter when he lived in California. Historically, he has donated to both Democrats and Republicans, many of whom serve in states in which he has a vested interest. Since 2022, his political contributions have mostly supported Republicans, with his first vote for a Republican going to Mayra Flores in the 2022 Texas's 34th congressional district special election. In 2024, he started supporting international far-right political parties, activists, and causes, and has shared misinformation and numerous conspiracy theories. Since 2024, his views have been generally described as right-wing. Musk supported Barack Obama in 2008 and 2012, Hillary Clinton in 2016, Joe Biden in 2020, and Donald Trump in 2024. In the 2020 Democratic Party presidential primaries, Musk endorsed candidate Andrew Yang and expressed support for Yang's proposed universal basic income, and endorsed Kanye West's 2020 presidential campaign. In 2021, Musk publicly expressed opposition to the Build Back Better Act, a $3.5 trillion legislative package endorsed by Joe Biden that ultimately failed to pass due to unanimous opposition from congressional Republicans and several Democrats. In 2022, gave over $50 million to Citizens for Sanity, a conservative political action committee. In 2023, he supported Republican Ron DeSantis for the 2024 U.S. presidential election, giving $10 million to his campaign, and hosted DeSantis's campaign announcement on a Twitter Spaces event. From June 2023 to January 2024, Musk hosted a bipartisan set of X Spaces with Republican and Democratic candidates, including Robert F. Kennedy Jr., Vivek Ramaswamy, and Dean Phillips. In October 2025, former vice-president Kamala Harris commented that it was a mistake from the Democratic side to not invite Musk to a White House electric vehicle event organized in August 2021 and featuring executives from General Motors, Ford and Stellantis, despite Tesla being "the major American manufacturer of extraordinary innovation in this space." Fortune remarked that this was a nod to United Auto Workers and organized labor. Harris said presidents should put aside political loyalties when it came to recognizing innovation, and guessed that the non-invitation impacted Musk's perspective. Fortune noted that, at the time, Musk said, "Yeah, seems odd that Tesla wasn't invited." A month later, he criticized Biden as "not the friendliest administration." Jacob Silverman, author of the book Gilded Rage: Elon Musk and the Radicalization of Silicon Valley, said that the tech industry represented by Musk, Thiel, Andreessen and other capitalists, actually flourished under Biden, but the tech leaders chose Trump for their common ground on cultural issues. By early 2024, Musk had become a vocal and financial supporter of Donald Trump. In July 2024, minutes after the attempted assassination of Donald Trump, Musk endorsed him for president saying; "I fully endorse President Trump and hope for his rapid recovery." During the presidential campaign, Musk joined Trump on stage at a campaign rally, and during the campaign promoted conspiracy theories and falsehoods about Democrats, election fraud and immigration, in support of Trump. Musk was the largest individual donor of the 2024 election. In 2025, Musk contributed $19 million to the Wisconsin Supreme Court race, hoping to influence the state's future redistricting efforts and its regulations governing car manufacturers and dealers. In 2023, Musk said he shunned the World Economic Forum because it was boring. The organization commented that they had not invited him since 2015. He has participated in Dialog, dubbed "Tech Bilderberg" and organized by Peter Thiel and Auren Hoffman, though. Musk's international political actions and comments have come under increasing scrutiny and criticism, especially from the governments and leaders of France, Germany, Norway, Spain and the United Kingdom, particularly due to his position in the U.S. government as well as ownership of X. An NBC News analysis found he had boosted far-right political movements to cut immigration and curtail regulation of business in at least 18 countries on six continents since 2023. During his speech after the second inauguration of Donald Trump, Musk twice made a gesture interpreted by many as a Nazi or a fascist Roman salute.[e] He thumped his right hand over his heart, fingers spread wide, and then extended his right arm out, emphatically, at an upward angle, palm down and fingers together. He then repeated the gesture to the crowd behind him. As he finished the gestures, he said to the crowd, "My heart goes out to you. It is thanks to you that the future of civilization is assured." It was widely condemned as an intentional Nazi salute in Germany, where making such gestures is illegal. The Anti-Defamation League said it was not a Nazi salute, but other Jewish organizations disagreed and condemned the salute. American public opinion was divided on partisan lines as to whether it was a fascist salute. Musk dismissed the accusations of Nazi sympathies, deriding them as "dirty tricks" and a "tired" attack. Neo-Nazi and white supremacist groups celebrated it as a Nazi salute. Multiple European political parties demanded that Musk be banned from entering their countries. The concept of DOGE emerged in a discussion between Musk and Donald Trump, and in August 2024, Trump committed to giving Musk an advisory role, with Musk accepting the offer. In November and December 2024, Musk suggested that the organization could help to cut the U.S. federal budget, consolidate the number of federal agencies, and eliminate the Consumer Financial Protection Bureau, and that its final stage would be "deleting itself". In January 2025, the organization was created by executive order, and Musk was designated a "special government employee". Musk led the organization and was a senior advisor to the president, although his official role is not clear. In sworn statement during a lawsuit, the director of the White House Office of Administration stated that Musk "is not an employee of the U.S. DOGE Service or U.S. DOGE Service Temporary Organization", "is not the U.S. DOGE Service administrator", and has "no actual or formal authority to make government decisions himself". Trump said two days later that he had put Musk in charge of DOGE. A federal judge has ruled that Musk acted as the de facto leader of DOGE. Musk's role in the second Trump administration, particularly in response to DOGE, has attracted public backlash. He was criticized for his treatment of federal government employees, including his influence over the mass layoffs of the federal workforce. He has prioritized secrecy within the organization and has accused others of violating privacy laws. A Senate report alleged that Musk could avoid up to $2 billion in legal liability as a result of DOGE's actions. In May 2025, Bill Gates accused Musk of "killing the world's poorest children" through his cuts to USAID, which modeling by Boston University estimated had resulted in 300,000 deaths by this time, most of them of children. By November 2025, the estimated death toll had increased to 400,000 children and 200,000 adults. Musk announced on May 28, 2025, that he would depart from the Trump administration as planned when the special government employee's 130 day deadline expired, with a White House official confirming that Musk's offboarding from the Trump administration was already underway. His departure was officially confirmed during a joint Oval Office press conference with Trump on May 30, 2025. @realDonaldTrump is in the Epstein files. That is the real reason they have not been made public. June 5, 2025 After leaving office, Musk criticized the Trump administration's Big Beautiful Bill, calling it a "disgusting abomination" due to its provisions increasing the deficit. A feud began between Musk and Trump, with its most notable event being Musk alleging Trump had ties to sex offender Jeffrey Epstein on X (formerly Twitter) on June 5, 2025. Trump responded on Truth Social stating that Musk went "CRAZY" after the "EV Mandate" was purportedly taken away and threatened to cut Musk's government contracts. Musk then called for a third Trump impeachment. The next day, Trump stated that he did not wish to reconcile with Musk, and added that Musk would face "very serious consequences" if he funds Democratic candidates. On June 11, Musk publicly apologized for the tweets against Trump, saying they "went too far". Views November 6, 2022 Rejecting the conservative label, Musk has described himself as a political moderate, even as his views have become more right-wing over time. His views have been characterized as libertarian and far-right, and after his involvement in European politics, they have received criticism from world leaders such as Emmanuel Macron and Olaf Scholz. Within the context of American politics, Musk supported Democratic candidates up until 2022, at which point he voted for a Republican for the first time. He has stated support for universal basic income, gun rights, freedom of speech, a tax on carbon emissions, and H-1B visas. Musk has expressed concern about issues such as artificial intelligence (AI) and climate change, and has been a critic of wealth tax, short-selling, and government subsidies. An immigrant himself, Musk has been accused of being anti-immigration, and regularly blames immigration policies for illegal immigration. He is also a pronatalist who believes population decline is the biggest threat to civilization, and identifies as a cultural Christian. Musk has long been an advocate for space colonization, especially the colonization of Mars. He has repeatedly pushed for humanity colonizing Mars, in order to become an interplanetary species and lower the risks of human extinction. Musk has promoted conspiracy theories and made controversial statements that have led to accusations of racism, sexism, antisemitism, transphobia, disseminating disinformation, and support of white pride. While describing himself as a "pro-Semite", his comments regarding George Soros and Jewish communities have been condemned by the Anti-Defamation League and the Biden White House. Musk was criticized during the COVID-19 pandemic for making unfounded epidemiological claims, defying COVID-19 lockdowns restrictions, and supporting the Canada convoy protest against vaccine mandates. He has amplified false claims of white genocide in South Africa. Musk has been critical of Israel's actions in the Gaza Strip during the Gaza war, praised China's economic and climate goals, suggested that Taiwan and China should resolve cross-strait relations, and was described as having a close relationship with the Chinese government. In Europe, Musk expressed support for Ukraine in 2022 during the Russian invasion, recommended referendums and peace deals on the annexed Russia-occupied territories, and supported the far-right Alternative for Germany political party in 2024. Regarding British politics, Musk blamed the 2024 UK riots on mass migration and open borders, criticized Prime Minister Keir Starmer for what he described as a "two-tier" policing system, and was subsequently attacked as being responsible for spreading misinformation and amplifying the far-right. He has also voiced his support for far-right activist Tommy Robinson and pledged electoral support for Reform UK. In February 2026, Musk described Spanish Prime Minister Pedro Sánchez as a "tyrant" following Sánchez's proposal to prohibit minors under the age of 16 from accessing social media platforms. Legal affairs In 2018, Musk was sued by the U.S. Securities and Exchange Commission (SEC) for a tweet stating that funding had been secured for potentially taking Tesla private.[f] The securities fraud lawsuit characterized the tweet as false, misleading, and damaging to investors, and sought to bar Musk from serving as CEO of publicly traded companies. Two days later, Musk settled with the SEC, without admitting or denying the SEC's allegations. As a result, Musk and Tesla were fined $20 million each, and Musk was forced to step down for three years as Tesla chairman but was able to remain as CEO. Shareholders filed a lawsuit over the tweet, and in February 2023, a jury found Musk and Tesla not liable. Musk has stated in interviews that he does not regret posting the tweet that triggered the SEC investigation. In 2019, Musk stated in a tweet that Tesla would build half a million cars that year. The SEC reacted by asking a court to hold him in contempt for violating the terms of the 2018 settlement agreement. A joint agreement between Musk and the SEC eventually clarified the previous agreement details, including a list of topics about which Musk needed preclearance. In 2020, a judge blocked a lawsuit that claimed a tweet by Musk regarding Tesla stock price ("too high imo") violated the agreement. Freedom of Information Act (FOIA)-released records showed that the SEC concluded Musk had subsequently violated the agreement twice by tweeting regarding "Tesla's solar roof production volumes and its stock price". In October 2023, the SEC sued Musk over his refusal to testify a third time in an investigation into whether he violated federal law by purchasing Twitter stock in 2022. In February 2024, Judge Laurel Beeler ruled that Musk must testify again. In January 2025, the SEC filed a lawsuit against Musk for securities violations related to his purchase of Twitter. In January 2024, Delaware judge Kathaleen McCormick ruled in a 2018 lawsuit that Musk's $55 billion pay package from Tesla be rescinded. McCormick called the compensation granted by the company's board "an unfathomable sum" that was unfair to shareholders. The Delaware Supreme Court overturned McCormick's decision in December 2025, restoring Musk's compensation package and awarding $1 in nominal damages. Personal life Musk became a U.S. citizen in 2002. From the early 2000s until late 2020, Musk resided in California, where both Tesla and SpaceX were founded. He then relocated to Cameron County, Texas, saying that California had become "complacent" about its economic success. While hosting Saturday Night Live in 2021, Musk stated that he has Asperger syndrome (an outdated term for autism spectrum disorder). When asked about his experience growing up with Asperger's syndrome in a TED2022 conference in Vancouver, Musk stated that "the social cues were not intuitive ... I would just tend to take things very literally ... but then that turned out to be wrong — [people were not] simply saying exactly what they mean, there's all sorts of other things that are meant, and [it] took me a while to figure that out." Musk suffers from back pain and has undergone several spine-related surgeries, including a disc replacement. In 2000, he contracted a severe case of malaria while on vacation in South Africa. Musk has stated he uses doctor-prescribed ketamine for occasional depression and that he doses "a small amount once every other week or something like that"; since January 2024, some media outlets have reported that he takes ketamine, marijuana, LSD, ecstasy, mushrooms, cocaine and other drugs. Musk at first refused to comment on his alleged drug use, before responding that he had not tested positive for drugs, and that if drugs somehow improved his productivity, "I would definitely take them!". The New York Times' investigations revealed Musk's overuse of ketamine and numerous other drugs, as well as strained family relationships and concerns from close associates who have become troubled by his public behavior as he became more involved in political activities and government work. According to The Washington Post, President Trump described Musk as "a big-time drug addict". Through his own label Emo G Records, Musk released a rap track, "RIP Harambe", on SoundCloud in March 2019. The following year, he released an EDM track, "Don't Doubt Ur Vibe", featuring his own lyrics and vocals. Musk plays video games, which he stated has a "'restoring effect' that helps his 'mental calibration'". Some games he plays include Quake, Diablo IV, Elden Ring, and Polytopia. Musk once claimed to be one of the world's top video game players but has since admitted to "account boosting", or cheating by hiring outside services to achieve top player rankings. Musk has justified the boosting by claiming that all top accounts do it so he has to as well to remain competitive. In 2024 and 2025, Musk criticized the video game Assassin's Creed Shadows and its creator Ubisoft for "woke" content. Musk posted to X that "DEI kills art" and specified the inclusion of the historical figure Yasuke in the Assassin's Creed game as offensive; he also called the game "terrible". Ubisoft responded by saying that Musk's comments were "just feeding hatred" and that they were focused on producing a game not pushing politics. Musk has fathered at least 14 children, one of whom died as an infant. The Wall Street Journal reported in 2025 that sources close to Musk suggest that the "true number of Musk's children is much higher than publicly known". He had six children with his first wife, Canadian author Justine Wilson, whom he met while attending Queen's University in Ontario, Canada; they married in 2000. In 2002, their first child Nevada Musk died of sudden infant death syndrome at the age of 10 weeks. After his death, the couple used in vitro fertilization (IVF) to continue their family; they had twins in 2004, followed by triplets in 2006. The couple divorced in 2008 and have shared custody of their children. The elder twin he had with Wilson came out as a trans woman and, in 2022, officially changed her name to Vivian Jenna Wilson, adopting her mother's surname because she no longer wished to be associated with Musk. Musk began dating English actress Talulah Riley in 2008. They married two years later at Dornoch Cathedral in Scotland. In 2012, the couple divorced, then remarried the following year. After briefly filing for divorce in 2014, Musk finalized a second divorce from Riley in 2016. Musk then dated the American actress Amber Heard for several months in 2017; he had reportedly been "pursuing" her since 2012. In 2018, Musk and Canadian musician Grimes confirmed they were dating. Grimes and Musk have three children, born in 2020, 2021, and 2022.[g] Musk and Grimes originally gave their eldest child the name "X Æ A-12", which would have violated California regulations as it contained characters that are not in the modern English alphabet; the names registered on the birth certificate are "X" as a first name, "Æ A-Xii" as a middle name, and "Musk" as a last name. They received criticism for choosing a name perceived to be impractical and difficult to pronounce; Musk has said the intended pronunciation is "X Ash A Twelve". Their second child was born via surrogacy. Despite the pregnancy, Musk confirmed reports that the couple were "semi-separated" in September 2021; in an interview with Time in December 2021, he said he was single. In October 2023, Grimes sued Musk over parental rights and custody of X Æ A-Xii. Elon Musk has taken X Æ A-Xii to multiple official events in Washington, D.C. during Trump's second term in office. Also in July 2022, The Wall Street Journal reported that Musk allegedly had an affair with Nicole Shanahan, the wife of Google co-founder Sergey Brin, in 2021, leading to their divorce the following year. Musk denied the report. Musk also had a relationship with Australian actress Natasha Bassett, who has been described as "an occasional girlfriend". In October 2024, The New York Times reported Musk bought a Texas compound for his children and their mothers, though Musk denied having done so. Musk also has four children with Shivon Zilis, director of operations and special projects at Neuralink: twins born via IVF in 2021, a child born in 2024 via surrogacy and a child born in 2025.[h] On February 14, 2025, Ashley St. Clair, an influencer and author, posted on X claiming to have given birth to Musk's son Romulus five months earlier, which media outlets reported as Musk's supposed thirteenth child.[i] On February 22, 2025, it was reported that St Clair had filed for sole custody of her five-month-old son and for Musk to be recognised as the child's father. On March 31, 2025, Musk wrote that, while he was unsure if he was the father of St. Clair's child, he had paid St. Clair $2.5 million and would continue paying her $500,000 per year.[j] Later reporting from the Wall Street Journal indicated that $1 million of these payments to St. Clair were structured as a loan. In 2014, Musk and Ghislaine Maxwell appeared together in a photograph taken at an Academy Awards after-party, which Musk later described as a "photobomb". The January 2026 Epstein files contain emails between Musk and Epstein from 2012 to 2013, after Epstein's first conviction. Emails released on January 30, 2026, indicated that Epstein invited Musk to visit his private island on multiple occasions. The correspondence showed that while Epstein repeatedly encouraged Musk to attend, Musk did not visit the island. In one instance, Musk discussed the possibility of attending a party with his then-wife Talulah Riley and asked which day would be the "wildest party"; according to the emails, the visit did not take place after Epstein later cancelled the plans.[k] On Christmas day in 2012, Musk emailed Epstein asking "Do you have any parties planned? I’ve been working to the edge of sanity this year and so, once my kids head home after Christmas, I really want to hit the party scene in St Barts or elsewhere and let loose. The invitation is much appreciated, but a peaceful island experience is the opposite of what I’m looking for". Epstein replied that the "ratio on my island" might make Musk's wife uncomfortable to which Musk responded, "Ratio is not a problem for Talulah". On September 11, 2013, Epstein sent an email asking Musk if he had any plans for coming to New York for the opening of the United Nations General Assembly where many "interesting people" would be coming to his house to which Musk responded that "Flying to NY to see UN diplomats do nothing would be an unwise use of time". Epstein responded by stating "Do you think i am retarded. Just kidding, there is no one over 25 and all very cute." Musk has denied any close relationship with Epstein and described him as a "creep" who attempted to ingratiate himself with influential people. When Musk was asked in 2019 if he introduced Epstein to Mark Zuckerberg, Musk responded: "I don’t recall introducing Epstein to anyone, as I don’t know the guy well enough to do so." The released emails nonetheless showed cordial exchanges on a range of topics, including Musk's inquiry about parties on the island. The correspondence also indicated that Musk suggested hosting Epstein at SpaceX, while Epstein separately discussed plans to tour SpaceX and bring "the girls", though there is no evidence that such a visit occurred. Musk has described the release of the files a "distraction", later accusing the second Trump administration of suppressing them to protect powerful individuals, including Trump himself.[l] Wealth Elon Musk is the wealthiest person in the world, with an estimated net worth of US$690 billion as of January 2026, according to the Bloomberg Billionaires Index, and $852 billion according to Forbes, primarily from his ownership stakes in SpaceX and Tesla. Having been first listed on the Forbes Billionaires List in 2012, around 75% of Musk's wealth was derived from Tesla stock in November 2020, although he describes himself as "cash poor". According to Forbes, he became the first person in the world to achieve a net worth of $300 billion in 2021; $400 billion in December 2024; $500 billion in October 2025; $600 billion in mid-December 2025; $700 billion later that month; and $800 billion in February 2026. In November 2025, a Tesla pay package worth potentially $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Public image Although his ventures have been highly influential within their separate industries starting in the 2000s, Musk only became a public figure in the early 2010s. He has been described as an eccentric who makes spontaneous and impactful decisions, while also often making controversial statements, contrary to other billionaires who prefer reclusiveness to protect their businesses. Musk's actions and his expressed views have made him a polarizing figure. Biographer Ashlee Vance described people's opinions of Musk as polarized due to his "part philosopher, part troll" persona on Twitter. He has drawn denouncement for using his platform to mock the self-selection of personal pronouns, while also receiving praise for bringing international attention to matters like British survivors of grooming gangs. Musk has been described as an American oligarch due to his extensive influence over public discourse, social media, industry, politics, and government policy. After Trump's re-election, Musk's influence and actions during the transition period and the second presidency of Donald Trump led some to call him "President Musk", the "actual president-elect", "shadow president" or "co-president". Awards for his contributions to the development of the Falcon rockets include the American Institute of Aeronautics and Astronautics George Low Transportation Award in 2008, the Fédération Aéronautique Internationale Gold Space Medal in 2010, and the Royal Aeronautical Society Gold Medal in 2012. In 2015, he received an honorary doctorate in engineering and technology from Yale University and an Institute of Electrical and Electronics Engineers Honorary Membership. Musk was elected a Fellow of the Royal Society (FRS) in 2018.[m] In 2022, Musk was elected to the National Academy of Engineering. Time has listed Musk as one of the most influential people in the world in 2010, 2013, 2018, and 2021. Musk was selected as Time's "Person of the Year" for 2021. Then Time editor-in-chief Edward Felsenthal wrote that, "Person of the Year is a marker of influence, and few individuals have had more influence than Musk on life on Earth, and potentially life off Earth too." Notes References Works cited Further reading External links |
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Contents Middle East The Middle East[b] is a geopolitical region encompassing the Arabian Peninsula, Egypt, Iran, Iraq, the Levant, and Turkey. The term came into widespread usage by Western European nations in the early 20th century as a replacement of the term Near East (both were in contrast to the Far East). The term "Middle East" has led to some confusion over its changing definitions. Since the late 20th century, it has been criticized as being too Eurocentric. The region includes the vast majority of the territories included in the closely associated definition of West Asia, but without the South Caucasus. It also includes all of Egypt (not just the Sinai region) and all of Turkey (including East Thrace). Most Middle Eastern countries (13 out of 18) are part of the Arab world. The three most populous countries in the region are Egypt, Iran, and Turkey, while Saudi Arabia is the largest Middle Eastern country by area. The history of the Middle East dates back to ancient times, and it was long considered the "cradle of civilization". The geopolitical importance of the region has been recognized and competed for during millennia. The Abrahamic religions (Judaism, Christianity, and Islam) have their origins in the Middle East. Arabs constitute the main ethnic group in the region, followed by Turks, Persians, Kurds, Jews, and Assyrians. The Middle East generally has a hot, arid climate, especially in the Arabian and Egyptian regions. Several major rivers provide irrigation to support agriculture in limited areas here, such as the Nile Delta in Egypt, the Tigris and Euphrates watersheds of Mesopotamia, and the basin of the Jordan River that spans most of the Levant. These regions are collectively known as the Fertile Crescent, and comprise the core of what historians had long referred to as the cradle of civilization; multiple regions of the world have since been classified as also having developed independent, original civilizations. Conversely, the Levantine coast and most of Turkey have relatively temperate climates typical of the Mediterranean, with dry summers and cool, wet winters. Most of the countries that border the Persian Gulf have vast reserves of petroleum. Monarchs of the Arabian Peninsula in particular have benefitted economically from petroleum exports. Because of the arid climate and dependence on the fossil fuel industry, the Middle East is both a major contributor to climate change and a region that is expected to be severely adversely affected by it. Other concepts of the region exist, including the broader Middle East and North Africa (MENA), which includes states of the Maghreb and the Sudan. The term the "Greater Middle East" also includes Afghanistan, Mauritania, Pakistan, as well as parts of East Africa, and sometimes Central Asia and the South Caucasus. Terminology The term "Middle East" may have originated in the 1850s in the British India Office. However, it became more widely known when United States naval strategist Alfred Thayer Mahan used the term in 1902 to "designate the area between Arabia and India". During this time the British and Russian empires were vying for influence in Central Asia, a rivalry that would become known as the Great Game. Mahan realized not only the strategic importance of the region, but also of its center, the Persian Gulf. He labeled the area surrounding the Persian Gulf as the Middle East. He said that, beyond Egypt's Suez Canal, the Gulf was the most important passage for Britain to control in order to keep the Russians from advancing towards British India. Mahan first used the term in his article "The Persian Gulf and International Relations", published in September 1902 in the National Review, a British journal. The Middle East, if I may adopt a term which I have not seen, will some day need its Malta, as well as its Gibraltar; it does not follow that either will be in the Persian Gulf. Naval force has the quality of mobility which carries with it the privilege of temporary absences; but it needs to find on every scene of operation established bases of refit, of supply, and in case of disaster, of security. The British Navy should have the facility to concentrate in force if occasion arise, about Aden, India, and the Persian Gulf. Mahan's article was reprinted in The Times and followed in October by a 20-article series entitled "The Middle Eastern Question", written by Sir Ignatius Valentine Chirol. During this series, Sir Ignatius expanded the definition of Middle East to include "those regions of Asia which extend to the borders of India or command the approaches to India." After the series ended in 1903, The Times removed quotation marks from subsequent uses of the term. Until World War II, it was customary to refer to areas centered on Turkey and the eastern shore of the Mediterranean as the "Near East", while the "Far East" centered on China, India and Japan. The Middle East was then defined as the area from Mesopotamia to Burma; namely, the area between the Near East and the Far East. This area broadly corresponds to South Asia. In the late 1930s, the British established the Middle East Command, which was based in Cairo, for its military forces in the region. After that time, the term "Middle East" gained broader usage in Europe and the United States. Following World War II, for example, the Middle East Institute was founded in Washington, D.C. in 1946. The corresponding adjective is Middle Eastern and the derived noun is Middle Easterner. While non-Eurocentric terms such as "Southwest Asia" or "Swasia" have been sparsely used, the classification of the African country, Egypt, among those counted in the Middle East challenges the usefulness of using such terms. The description Middle has also led to some confusion over changing definitions. Before the First World War, "Near East" was used in English to refer to the Balkans and the Ottoman Empire, while "Middle East" referred to the Caucasus, Persia, and Arabian lands, and sometimes Afghanistan, India and others. In contrast, "Far East" referred to the countries of East Asia (e.g. China, Japan, and Korea). With the collapse of the Ottoman Empire in 1918, "Near East" largely fell out of common use in English, while "Middle East" came to be applied to the emerging independent countries of the Islamic world. However, the usage "Near East" was retained by a variety of academic disciplines, including archaeology and ancient history. In their usage, the term describes an area identical to the term Middle East, which is not used by these disciplines (see ancient Near East).[citation needed] The first official use of the term "Middle East" by the United States government was in the 1957 Eisenhower Doctrine, which pertained to the Suez Crisis. Secretary of State John Foster Dulles defined the Middle East as "the area lying between and including Libya on the west and Pakistan on the east, Syria and Iraq on the North and the Arabian peninsula to the south, plus the Sudan and Ethiopia." In 1958, the State Department explained that the terms "Near East" and "Middle East" were interchangeable, and defined the region as including only Egypt, Syria, Israel, Lebanon, Jordan, Iraq, Saudi Arabia, Kuwait, Bahrain, and Qatar. Since the late 20th century, scholars and journalists from the region, such as journalist Louay Khraish and historian Hassan Hanafi have criticized the use of "Middle East" as a Eurocentric and colonialist term. The Associated Press Stylebook of 2004 says that Near East formerly referred to the farther west countries while Middle East referred to the eastern ones, but that now they are synonymous. It instructs: Use Middle East unless Near East is used by a source in a story. Mideast is also acceptable, but Middle East is preferred. European languages have adopted terms similar to Near East and Middle East. Since these are based on a relative description, the meanings depend on the country and are generally different from the English terms. In German the term Naher Osten (Near East) is still in common use (nowadays the term Mittlerer Osten is more and more common in press texts translated from English sources, albeit having a distinct meaning). In the four Slavic languages, Russian Ближний Восток or Blizhniy Vostok, Bulgarian Близкия Изток, Polish Bliski Wschód or Croatian Bliski istok (terms meaning Near East are the only appropriate ones for the region). However, some European languages do have "Middle East" equivalents, such as French Moyen-Orient, Swedish Mellanöstern, Spanish Oriente Medio or Medio Oriente, Greek is Μέση Ανατολή (Mesi Anatoli), and Italian Medio Oriente.[c] Perhaps because of the political influence of the United States and Europe, and the prominence of Western press, the Arabic equivalent of Middle East (Arabic: الشرق الأوسط ash-Sharq al-Awsaṭ) has become standard usage in the mainstream Arabic press. It comprises the same meaning as the term "Middle East" in North American and Western European usage. The designation, Mashriq, also from the Arabic root for East, also denotes a variously defined region around the Levant, the eastern part of the Arabic-speaking world (as opposed to the Maghreb, the western part). Even though the term originated in the West, countries of the Middle East that use languages other than Arabic also use that term in translation. For instance, the Persian equivalent for Middle East is خاورمیانه (Khāvar-e miyāneh), the Hebrew is המזרח התיכון (hamizrach hatikhon), and the Turkish is Orta Doğu. Countries and territory Traditionally included within the Middle East are Arabia, Asia Minor, East Thrace, Egypt, Iran, the Levant, Mesopotamia, and the Socotra Archipelago. The region includes 17 UN-recognized countries and one British Overseas Territory. Various concepts are often paralleled to the Middle East, most notably the Near East, Fertile Crescent, and Levant. These are geographical concepts, which refer to large sections of the modern-day Middle East, with the Near East being the closest to the Middle East in its geographical meaning. Due to it primarily being Arabic speaking, the Maghreb region of North Africa is sometimes included. "Greater Middle East" is a political term coined by the second Bush administration in the first decade of the 21st century to denote various countries, pertaining to the Muslim world, specifically Afghanistan, Iran, Pakistan, and Turkey. Various Central Asian countries are sometimes also included. History The Middle East lies at the juncture of Africa and Eurasia and of the Indian Ocean and the Mediterranean Sea (see also: Indo-Mediterranean). It is the birthplace and spiritual center of religions such as Christianity, Islam, Judaism, Manichaeism, Yezidi, Druze, Yarsan, and Mandeanism, and in Iran, Mithraism, Zoroastrianism, Manicheanism, and the Baháʼí Faith. Throughout its history the Middle East has been a major center of world affairs; a strategically, economically, politically, culturally, and religiously sensitive area. The region is one of the regions where agriculture was independently discovered, and from the Middle East it was spread, during the Neolithic, to different regions of the world such as Europe, the Indus Valley and Eastern Africa. Prior to the formation of civilizations, advanced cultures formed all over the Middle East during the Stone Age. The search for agricultural lands by agriculturalists, and pastoral lands by herdsmen meant different migrations took place within the region and shaped its ethnic and demographic makeup. The Middle East is widely and most famously known as the cradle of civilization. The world's earliest civilizations, Mesopotamia (Sumer, Akkad, Assyria and Babylonia), ancient Egypt and Kish in the Levant, all originated in the Fertile Crescent and Nile Valley regions of the ancient Near East. These were followed by the Hittite, Greek, Hurrian and Urartian civilisations of Asia Minor; Elam, Persia and Median civilizations in Iran, as well as the civilizations of the Levant (such as Ebla, Mari, Nagar, Ugarit, Canaan, Aramea, Mitanni, Phoenicia and Israel) and the Arabian Peninsula (Magan, Sheba, Ubar). The Near East was first largely unified under the Neo Assyrian Empire, then the Achaemenid Empire followed later by the Macedonian Empire and after this to some degree by the Iranian empires (namely the Parthian and Sassanid Empires), the Roman Empire and Byzantine Empire. The region served as the intellectual and economic center of the Roman Empire and played an exceptionally important role due to its periphery on the Sassanid Empire. Thus, the Romans stationed up to five or six of their legions in the region for the sole purpose of defending it from Sassanid and Bedouin raids and invasions. From the 4th century CE onwards, the Middle East became the center of the two main powers at the time, the Byzantine Empire and the Sassanid Empire. However, it would be the later Islamic Caliphates of the Middle Ages, or Islamic Golden Age which began with the Islamic conquest of the region in the 7th century AD, that would first unify the entire Middle East as a distinct region and create the dominant Islamic Arab ethnic identity that largely (but not exclusively) persists today. The 4 caliphates that dominated the Middle East for more than 600 years were the Rashidun Caliphate, the Umayyad caliphate, the Abbasid caliphate and the Fatimid caliphate. Additionally, the Mongols would come to dominate the region, the Kingdom of Armenia would incorporate parts of the region to their domain, the Seljuks would rule the region and spread Turko-Persian culture, and the Franks would found the Crusader states that would stand for roughly two centuries. Josiah Russell estimates the population of what he calls "Islamic territory" as roughly 12.5 million in 1000 – Anatolia 8 million, Syria 2 million, and Egypt 1.5 million. From the 16th century onward, the Middle East came to be dominated, once again, by two main powers: the Ottoman Empire and the Safavid dynasty. The modern Middle East began after World War I, when the Ottoman Empire, which was allied with the Central Powers, was defeated by the Allies and partitioned into a number of separate nations, initially under British and French Mandates. Other defining events in this transformation included the establishment of Israel in 1948 and the eventual departure of European powers, notably Britain and France by the end of the 1960s. They were supplanted in some part by the rising influence of the United States from the 1970s onwards. In the 20th century, the region's significant stocks of crude oil gave it new strategic and economic importance. Mass production of oil began around 1945, with Saudi Arabia, Iran, Kuwait, Iraq, and the United Arab Emirates having large quantities of oil. Estimated oil reserves, especially in Saudi Arabia and Iran, are some of the highest in the world, and the international oil cartel OPEC is dominated by Middle Eastern countries. During the Cold War, the Middle East was a theater of ideological struggle between the two superpowers and their allies: NATO and the United States on one side, and the Soviet Union and Warsaw Pact on the other, as they competed to influence regional allies. Besides the political reasons there was also the "ideological conflict" between the two systems. Moreover, as Louise Fawcett argues, among many important areas of contention, or perhaps more accurately of anxiety, were, first, the desires of the superpowers to gain strategic advantage in the region, second, the fact that the region contained some two-thirds of the world's oil reserves in a context where oil was becoming increasingly vital to the economy of the Western world [...] Within this contextual framework, the United States sought to divert the Arab world from Soviet influence. Throughout the 20th and 21st centuries, the region has experienced both periods of relative peace and tolerance and periods of conflict particularly between Sunnis and Shiites. Geography In 2018, the MENA region emitted 3.2 billion tonnes of carbon dioxide and produced 8.7% of global greenhouse gas emissions (GHG) despite making up only 6% of the global population. These emissions are mostly from the energy sector, an integral component of many Middle Eastern and North African economies due to the extensive oil and natural gas reserves that are found within the region. The Middle East region is one of the most vulnerable to climate change. The impacts include increase in drought conditions, aridity, heatwaves and sea level rise. Sharp global temperature and sea level changes, shifting precipitation patterns and increased frequency of extreme weather events are some of the main impacts of climate change as identified by the Intergovernmental Panel on Climate Change (IPCC). The MENA region is especially vulnerable to such impacts due to its arid and semi-arid environment, facing climatic challenges such as low rainfall, high temperatures and dry soil. The climatic conditions that foster such challenges for MENA are projected by the IPCC to worsen throughout the 21st century. If greenhouse gas emissions are not significantly reduced, part of the MENA region risks becoming uninhabitable before the year 2100. Climate change is expected to put significant strain on already scarce water and agricultural resources within the MENA region, threatening the national security and political stability of all included countries. Over 60 percent of the region's population lives in high and very high water-stressed areas compared to the global average of 35 percent. This has prompted some MENA countries to engage with the issue of climate change on an international level through environmental accords such as the Paris Agreement. Law and policy are also being established on a national level amongst MENA countries, with a focus on the development of renewable energies. Economy Middle Eastern economies range from being very poor (such as Gaza and Yemen) to extremely wealthy nations (such as Qatar and UAE). According to the International Monetary Fund, the three largest Middle Eastern economies in nominal GDP in 2023 were Saudi Arabia ($1.06 trillion), Turkey ($1.03 trillion), and Israel ($0.54 trillion). For nominal GDP per person, the highest ranking countries are Qatar ($83,891), Israel ($55,535), the United Arab Emirates ($49,451) and Cyprus ($33,807). Turkey ($3.6 trillion), Saudi Arabia ($2.3 trillion), and Iran ($1.7 trillion) had the largest economies in terms of GDP PPP. For GDP PPP per person, the highest-ranking countries are Qatar ($124,834), the United Arab Emirates ($88,221), Saudi Arabia ($64,836), Bahrain ($60,596) and Israel ($54,997). The lowest-ranking country in the Middle East, in terms of GDP nominal per capita, is Yemen ($573). The economic structure of Middle Eastern nations are different because while some are heavily dependent on export of only oil and oil-related products (Saudi Arabia, the UAE and Kuwait), others have a highly diverse economic base (such as Cyprus, Israel, Turkey and Egypt). Industries of the Middle Eastern region include oil and oil-related products, agriculture, cotton, cattle, dairy, textiles, leather products, surgical instruments, defence equipment (guns, ammunition, tanks, submarines, fighter jets, UAVs, and missiles). Banking is an important sector, especially for UAE and Bahrain. With the exception of Cyprus, Turkey, Egypt, Lebanon and Israel, tourism has been a relatively undeveloped area of the economy, in part because of the socially conservative nature of the region as well as political turmoil in certain regions. Since the end of the COVID pandemic however, countries such as the UAE, Bahrain, and Jordan have begun attracting greater numbers of tourists because of improving tourist facilities and the relaxing of tourism-related restrictive policies. Unemployment is high in the Middle East and North Africa region, particularly among people aged 15–29, a demographic representing 30% of the region's population. The total regional unemployment rate in 2025 is 10.8%, and among youth is as high as 28%. Demographics Arabs constitute the largest ethnic group in the Middle East, followed by various Iranian peoples and then by Turkic peoples (Turkish, Azeris, Syrian Turkmen, and Iraqi Turkmen). Native ethnic groups of the region include, in addition to Arabs, Arameans, Assyrians, Baloch, Berbers, Copts, Druze, Greek Cypriots, Jews, Kurds, Lurs, Mandaeans, Persians, Samaritans, Shabaks, Tats, and Zazas. European ethnic groups that form a diaspora in the region include Albanians, Bosniaks, Circassians (including Kabardians), Crimean Tatars, Greeks, Franco-Levantines, Italo-Levantines, and Iraqi Turkmens. Among other migrant populations are Chinese, Filipinos, Indians, Indonesians, Pakistanis, Pashtuns, Romani, and Afro-Arabs. "Migration has always provided an important vent for labor market pressures in the Middle East. For the period between the 1970s and 1990s, the Arab states of the Persian Gulf in particular provided a rich source of employment for workers from Egypt, Yemen and the countries of the Levant, while Europe had attracted young workers from North African countries due both to proximity and the legacy of colonial ties between France and the majority of North African states." According to the International Organization for Migration, there are 13 million first-generation migrants from Arab nations in the world, of which 5.8 reside in other Arab countries. Expatriates from Arab countries contribute to the circulation of financial and human capital in the region and thus significantly promote regional development. In 2009 Arab countries received a total of US$35.1 billion in remittance in-flows and remittances sent to Jordan, Egypt and Lebanon from other Arab countries are 40 to 190 per cent higher than trade revenues between these and other Arab countries. In Somalia, the Somali Civil War has greatly increased the size of the Somali diaspora, as many of the best educated Somalis left for Middle Eastern countries as well as Europe and North America. Non-Arab Middle Eastern countries such as Turkey, Israel and Iran are also subject to important migration dynamics. A fair proportion of those migrating from Arab nations are from ethnic and religious minorities facing persecution and are not necessarily ethnic Arabs, Iranians or Turks.[citation needed] Large numbers of Kurds, Jews, Assyrians, Greeks and Armenians as well as many Mandeans have left nations such as Iraq, Iran, Syria and Turkey for these reasons during the last century. In Iran, many religious minorities such as Christians, Baháʼís, Jews and Zoroastrians have left since the Islamic Revolution of 1979. The Middle East is very diverse when it comes to religions, many of which originated there. Islam is the largest religion in the Middle East, but other faiths that originated there, such as Judaism and Christianity, are also well represented. Christian communities have played a vital role in the Middle East, and they represent 78% of Cyprus population, and 40.5% of Lebanon, where the Lebanese president, half of the cabinet, and half of the parliament follow one of the various Lebanese Christian rites. There are also important minority religions like the Baháʼí Faith, Yarsanism, Yazidism, Zoroastrianism, Mandaeism, Druze, and Shabakism, and in ancient times the region was home to Mesopotamian religions, Canaanite religions, Manichaeism, Mithraism and various monotheist gnostic sects. The six top languages, in terms of numbers of speakers, are Arabic, Persian, Turkish, Kurdish, Modern Hebrew and Greek. About 20 minority languages are also spoken in the Middle East. Arabic, with all its dialects, is the most widely spoken language in the Middle East, with Literary Arabic being official in all North African and in most West Asian countries. Arabic dialects are also spoken in some adjacent areas in neighbouring Middle Eastern non-Arab countries. It is a member of the Semitic branch of the Afro-Asiatic languages. Several Modern South Arabian languages such as Mehri and Soqotri are also spoken in Yemen and Oman. Another Semitic language is Aramaic and its dialects are spoken mainly by Assyrians and Mandaeans, with Western Aramaic still spoken in two villages near Damascus, Syria. There is also an Oasis Berber-speaking community in Egypt where the language is also known as Siwa. It is a non-Semitic Afro-Asiatic sister language. Persian is the second most spoken language. While it is primarily spoken in Iran and some border areas in neighbouring countries, the country is one of the region's largest and most populous. It belongs to the Indo-Iranian branch of the family of Indo-European languages. Other Western Iranic languages spoken in the region include Achomi, Daylami, Kurdish dialects, Semmani, Lurish, amongst many others. The close third-most widely spoken language, Turkish, is largely confined to Turkey, which is also one of the region's largest and most populous countries, but it is present in areas in neighboring countries. It is a member of the Turkic languages, which have their origins in East Asia. Another Turkic language, Azerbaijani, is spoken by Azerbaijanis in Iran. The fourth-most widely spoken language, Kurdish, is spoken in the countries of Iran, Iraq, Syria and Turkey, Sorani Kurdish is the second official language in Iraq (instated after the 2005 constitution) after Arabic. Hebrew is the official language of Israel, with Arabic given a special status after the 2018 Basic law lowered its status from an official language prior to 2018. Hebrew is spoken and used by over 80% of Israel's population, the other 20% using Arabic. Modern Hebrew only began being spoken in the 20th century after being revived in the late 19th century by Elizer Ben-Yehuda (Elizer Perlman) and European Jewish settlers, with the first native Hebrew speaker being born in 1882. Greek is one of the two official languages of Cyprus, and the country's main language. Small communities of Greek speakers exist all around the Middle East; until the 20th century it was also widely spoken in Asia Minor (being the second most spoken language there, after Turkish) and Egypt. During the antiquity, Ancient Greek was the lingua franca for many areas of the western Middle East and until the Muslim expansion it was widely spoken there as well. Until the late 11th century, it was also the main spoken language in Asia Minor; after that it was gradually replaced by the Turkish language as the Anatolian Turks expanded and the local Greeks were assimilated, especially in the interior. English is one of the official languages of Akrotiri and Dhekelia. It is also commonly taught and used as a foreign second language, in countries such as Egypt, Jordan, Iran, Iraq, Qatar, Bahrain, United Arab Emirates and Kuwait. It is also a main language in some Emirates of the United Arab Emirates. It is also spoken as native language by Jewish immigrants from Anglophone countries (UK, US, Australia) in Israel and understood widely as second language there. French is taught and used in many government facilities and media in Lebanon, and is taught in some primary and secondary schools of Egypt and Syria. Maltese, a Semitic language mainly spoken in Europe, is used by the Franco-Maltese diaspora in Egypt. Due to widespread immigration of French Jews to Israel, it is the native language of approximately 200,000 Jews in Israel. Armenian speakers are to be found in the region. Georgian is spoken by the Georgian diaspora. Russian is spoken by a large portion of the Israeli population, because of emigration in the late 1990s. Russian today is a popular unofficial language in use in Israel; news, radio and sign boards can be found in Russian around the country after Hebrew and Arabic. Circassian is also spoken by the diaspora in the region and by almost all Circassians in Israel who speak Hebrew and English as well. The largest Romanian-speaking community in the Middle East is found in Israel, where as of 1995[update] Romanian is spoken by 5% of the population.[d] Bengali, Hindi and Urdu are widely spoken by migrant communities in many Middle Eastern countries, such as Saudi Arabia (where 20–25% of the population is South Asian), the United Arab Emirates (where 50–55% of the population is South Asian), and Qatar, which have large numbers of Pakistani, Bangladeshi and Indian immigrants. Culture The Middle East has recently become more prominent in hosting global sport events due to its wealth and desire to diversify its economy. The South Asian diaspora is a major backer of cricket in the region. See also Notes References Further reading External links 29°N 41°E / 29°N 41°E / 29; 41 |
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Contents Internet The Internet (or internet)[a] is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP)[b] to communicate between networks and devices. It is a network of networks that comprises private, public, academic, business, and government networks of local to global scope, linked by electronic, wireless, and optical networking technologies. The Internet carries a vast range of information services and resources, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail, discussion groups, internet telephony, streaming media and file sharing. Most traditional communication media, including telephone, radio, television, paper mail, newspapers, and print publishing, have been transformed by the Internet, giving rise to new media such as email, online music, digital newspapers, news aggregators, and audio and video streaming websites. The Internet has enabled and accelerated new forms of personal interaction through instant messaging, Internet forums, and social networking services. Online shopping has also grown to occupy a significant market across industries, enabling firms to extend brick and mortar presences to serve larger markets. Business-to-business and financial services on the Internet affect supply chains across entire industries. The origins of the Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching, and the design of computer networks for data communication. The set of communication protocols to enable internetworking on the Internet arose from research and development commissioned in the 1970s by the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense in collaboration with universities and researchers across the United States and in the United Kingdom and France. The Internet has no single centralized governance in either technological implementation or policies for access and usage. Each constituent network sets its own policies. The overarching definitions of the two principal name spaces on the Internet, the Internet Protocol address (IP address) space and the Domain Name System (DNS), are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols is an activity of the non-profit Internet Engineering Task Force (IETF). Terminology The word internetted was used as early as 1849, meaning interconnected or interwoven. The word Internet was used in 1945 by the United States War Department in a radio operator's manual, and in 1974 as the shorthand form of Internetwork. Today, the term Internet most commonly refers to the global system of interconnected computer networks, though it may also refer to any group of smaller networks. The word Internet may be capitalized as a proper noun, although this is becoming less common. This reflects the tendency in English to capitalize new terms and move them to lowercase as they become familiar. The word is sometimes still capitalized to distinguish the global internet from smaller networks, though many publications, including the AP Stylebook since 2016, recommend the lowercase form in every case. In 2016, the Oxford English Dictionary found that, based on a study of around 2.5 billion printed and online sources, "Internet" was capitalized in 54% of cases. The terms Internet and World Wide Web are often used interchangeably; it is common to speak of "going on the Internet" when using a web browser to view web pages. However, the World Wide Web, or the Web, is only one of a large number of Internet services. It is the global collection of web pages, documents and other web resources linked by hyperlinks and URLs. History In the 1960s, computer scientists began developing systems for time-sharing of computer resources. J. C. R. Licklider proposed the idea of a universal network while working at Bolt Beranek & Newman and, later, leading the Information Processing Techniques Office at the Advanced Research Projects Agency (ARPA) of the United States Department of Defense. Research into packet switching,[c] one of the fundamental Internet technologies, started in the work of Paul Baran at RAND in the early 1960s and, independently, Donald Davies at the United Kingdom's National Physical Laboratory in 1965. After the Symposium on Operating Systems Principles in 1967, packet switching from the proposed NPL network was incorporated into the design of the ARPANET, an experimental resource sharing network proposed by ARPA. ARPANET development began with two network nodes which were interconnected between the University of California, Los Angeles and the Stanford Research Institute on 29 October 1969. The third site was at the University of California, Santa Barbara, followed by the University of Utah. By the end of 1971, 15 sites were connected to the young ARPANET. Thereafter, the ARPANET gradually developed into a decentralized communications network, connecting remote centers and military bases in the United States. Other user networks and research networks, such as the Merit Network and CYCLADES, were developed in the late 1960s and early 1970s. Early international collaborations for the ARPANET were rare. Connections were made in 1973 to Norway (NORSAR and, later, NDRE) and to Peter Kirstein's research group at University College London, which provided a gateway to British academic networks, the first internetwork for resource sharing. ARPA projects, the International Network Working Group and commercial initiatives led to the development of various protocols and standards by which multiple separate networks could become a single network, or a network of networks. In 1974, Vint Cerf at Stanford University and Bob Kahn at DARPA published a proposal for "A Protocol for Packet Network Intercommunication". Cerf and his graduate students used the term internet as a shorthand for internetwork in RFC 675. The Internet Experiment Notes and later RFCs repeated this use. The work of Louis Pouzin and Robert Metcalfe had important influences on the resulting TCP/IP design. National PTTs and commercial providers developed the X.25 standard and deployed it on public data networks. The ARPANET initially served as a backbone for the interconnection of regional academic and military networks in the United States to enable resource sharing. Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) funded the Computer Science Network (CSNET). In 1982, the Internet Protocol Suite (TCP/IP) was standardized, which facilitated worldwide proliferation of interconnected networks. TCP/IP network access expanded again in 1986 when the National Science Foundation Network (NSFNet) provided access to supercomputer sites in the United States for researchers, first at speeds of 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s. The NSFNet expanded into academic and research organizations in Europe, Australia, New Zealand and Japan in 1988–89. Although other network protocols such as UUCP and PTT public data networks had global reach well before this time, this marked the beginning of the Internet as an intercontinental network. Commercial Internet service providers emerged in 1989 in the United States and Australia. The ARPANET was decommissioned in 1990. The linking of commercial networks and enterprises by the early 1990s, as well as the advent of the World Wide Web, marked the beginning of the transition to the modern Internet. Steady advances in semiconductor technology and optical networking created new economic opportunities for commercial involvement in the expansion of the network in its core and for delivering services to the public. In mid-1989, MCI Mail and Compuserve established connections to the Internet, delivering email and public access products to the half million users of the Internet. Just months later, on 1 January 1990, PSInet launched an alternate Internet backbone for commercial use; one of the networks that added to the core of the commercial Internet of later years. In March 1990, the first high-speed T1 (1.5 Mbit/s) link between the NSFNET and Europe was installed between Cornell University and CERN, allowing much more robust communications than were capable with satellites. Later in 1990, Tim Berners-Lee began writing WorldWideWeb, the first web browser, after two years of lobbying CERN management. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9, the HyperText Markup Language (HTML), the first Web browser (which was also an HTML editor and could access Usenet newsgroups and FTP files), the first HTTP server software (later known as CERN httpd), the first web server, and the first Web pages that described the project itself. In 1991 the Commercial Internet eXchange was founded, allowing PSInet to communicate with the other commercial networks CERFnet and Alternet. Stanford Federal Credit Union was the first financial institution to offer online Internet banking services to all of its members in October 1994. In 1996, OP Financial Group, also a cooperative bank, became the second online bank in the world and the first in Europe. By 1995, the Internet was fully commercialized in the U.S. when the NSFNet was decommissioned, removing the last restrictions on use of the Internet to carry commercial traffic. As technology advanced and commercial opportunities fueled reciprocal growth, the volume of Internet traffic started experiencing similar characteristics as that of the scaling of MOS transistors, exemplified by Moore's law, doubling every 18 months. This growth, formalized as Edholm's law, was catalyzed by advances in MOS technology, laser light wave systems, and noise performance. Since 1995, the Internet has tremendously impacted culture and commerce, including the rise of near-instant communication by email, instant messaging, telephony (Voice over Internet Protocol or VoIP), two-way interactive video calls, and the World Wide Web. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1 Gbit/s, 10 Gbit/s, or more. The Internet continues to grow, driven by ever-greater amounts of online information and knowledge, commerce, entertainment and social networking services. During the late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%. This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network. In November 2006, the Internet was included on USA Today's list of the New Seven Wonders. As of 31 March 2011[update], the estimated total number of Internet users was 2.095 billion (30% of world population). It is estimated that in 1993 the Internet carried only 1% of the information flowing through two-way telecommunication. By 2000 this figure had grown to 51%, and by 2007 more than 97% of all telecommunicated information was carried over the Internet. Modern smartphones can access the Internet through cellular carrier networks, and internet usage by mobile and tablet devices exceeded desktop worldwide for the first time in October 2016. As of 2018[update], 80% of the world's population were covered by a 4G network. The International Telecommunication Union (ITU) estimated that, by the end of 2017, 48% of individual users regularly connect to the Internet, up from 34% in 2012. Mobile Internet connectivity has played an important role in expanding access in recent years, especially in Asia and the Pacific and in Africa. The number of unique mobile cellular subscriptions increased from 3.9 billion in 2012 to 4.8 billion in 2016, two-thirds of the world's population, with more than half of subscriptions located in Asia and the Pacific. The limits that users face on accessing information via mobile applications coincide with a broader process of fragmentation of the Internet. Fragmentation restricts access to media content and tends to affect the poorest users the most. One solution, zero-rating, is the practice of Internet service providers allowing users free connectivity to access specific content or applications without cost. Social impact The Internet has enabled new forms of social interaction, activities, and social associations, giving rise to the scholarly study of the sociology of the Internet. Between 2000 and 2009, the number of Internet users globally rose from 390 million to 1.9 billion. By 2010, 22% of the world's population had access to computers with 1 billion Google searches every day, 300 million Internet users reading blogs, and 2 billion videos viewed daily on YouTube. In 2014 the world's Internet users surpassed 3 billion or 44 percent of world population, but two-thirds came from the richest countries, with 78 percent of Europeans using the Internet, followed by 57 percent of the Americas. However, by 2018, Asia alone accounted for 51% of all Internet users, with 2.2 billion out of the 4.3 billion Internet users in the world. China's Internet users surpassed a major milestone in 2018, when the country's Internet regulatory authority, China Internet Network Information Centre, announced that China had 802 million users. China was followed by India, with some 700 million users, with the United States third with 275 million users. However, in terms of penetration, in 2022, China had a 70% penetration rate compared to India's 60% and the United States's 90%. In 2022, 54% of the world's Internet users were based in Asia, 14% in Europe, 7% in North America, 10% in Latin America and the Caribbean, 11% in Africa, 4% in the Middle East and 1% in Oceania. In 2019, Kuwait, Qatar, the Falkland Islands, Bermuda and Iceland had the highest Internet penetration by the number of users, with 93% or more of the population with access. As of 2022, it was estimated that 5.4 billion people use the Internet, more than two-thirds of the world's population. Early computer systems were limited to the characters in the American Standard Code for Information Interchange (ASCII), a subset of the Latin alphabet. After English (27%), the most requested languages on the World Wide Web are Chinese (25%), Spanish (8%), Japanese (5%), Portuguese and German (4% each), Arabic, French and Russian (3% each), and Korean (2%). Modern character encoding standards, such as Unicode, allow for development and communication in the world's widely used languages. However, some glitches such as mojibake (incorrect display of some languages' characters) still remain. Several neologisms exist that refer to Internet users: Netizen (as in "citizen of the net") refers to those actively involved in improving online communities, the Internet in general or surrounding political affairs and rights such as free speech, Internaut refers to operators or technically highly capable users of the Internet, digital citizen refers to a person using the Internet in order to engage in society, politics, and government participation. The Internet allows greater flexibility in working hours and location, especially with the spread of unmetered high-speed connections. The Internet can be accessed almost anywhere by numerous means, including through mobile Internet devices. Mobile phones, datacards, handheld game consoles and cellular routers allow users to connect to the Internet wirelessly.[citation needed] Educational material at all levels from pre-school (e.g. CBeebies) to post-doctoral (e.g. scholarly literature through Google Scholar) is available on websites. The internet has facilitated the development of virtual universities and distance education, enabling both formal and informal education. The Internet allows researchers to conduct research remotely via virtual laboratories, with profound changes in reach and generalizability of findings as well as in communication between scientists and in the publication of results. By the late 2010s the Internet had been described as "the main source of scientific information "for the majority of the global North population".: 111 Wikis have also been used in the academic community for sharing and dissemination of information across institutional and international boundaries. In those settings, they have been found useful for collaboration on grant writing, strategic planning, departmental documentation, and committee work. The United States Patent and Trademark Office uses a wiki to allow the public to collaborate on finding prior art relevant to examination of pending patent applications. Queens, New York has used a wiki to allow citizens to collaborate on the design and planning of a local park. The English Wikipedia has the largest user base among wikis on the World Wide Web and ranks in the top 10 among all sites in terms of traffic. The Internet has been a major outlet for leisure activity since its inception, with entertaining social experiments such as MUDs and MOOs being conducted on university servers, and humor-related Usenet groups receiving much traffic. Many Internet forums have sections devoted to games and funny videos. Another area of leisure activity on the Internet is multiplayer gaming. This form of recreation creates communities, where people of all ages and origins enjoy the fast-paced world of multiplayer games. These range from MMORPG to first-person shooters, from role-playing video games to online gambling. While online gaming has been around since the 1970s, modern modes of online gaming began with subscription services such as GameSpy and MPlayer. Streaming media is the real-time delivery of digital media for immediate consumption or enjoyment by end users. Streaming companies (such as Netflix, Disney+, Amazon's Prime Video, Mubi, Hulu, and Apple TV+) now dominate the entertainment industry, eclipsing traditional broadcasters. Audio streamers such as Spotify and Apple Music also have significant market share in the audio entertainment market. Video sharing websites are also a major factor in the entertainment ecosystem. YouTube was founded on 15 February 2005 and is now the leading website for free streaming video with more than two billion users. It uses a web player to stream and show video files. YouTube users watch hundreds of millions, and upload hundreds of thousands, of videos daily. Other video sharing websites include Vimeo, Instagram and TikTok.[citation needed] Although many governments have attempted to restrict both Internet pornography and online gambling, this has generally failed to stop their widespread popularity. A number of advertising-funded ostensible video sharing websites known as "tube sites" have been created to host shared pornographic video content. Due to laws requiring the documentation of the origin of pornography, these websites now largely operate in conjunction with pornographic movie studios and their own independent creator networks, acting as de-facto video streaming services. Major players in this field include the market leader Aylo, the operator of PornHub and numerous other branded sites, as well as other independent operators such as xHamster and Xvideos. As of 2023[update], Internet traffic to pornographic video sites rivalled that of mainstream video streaming and sharing services. Remote work is facilitated by tools such as groupware, virtual private networks, conference calling, videotelephony, and VoIP so that work may be performed from any location, such as the worker's home.[citation needed] The spread of low-cost Internet access in developing countries has opened up new possibilities for peer-to-peer charities, which allow individuals to contribute small amounts to charitable projects for other individuals. Websites, such as DonorsChoose and GlobalGiving, allow small-scale donors to direct funds to individual projects of their choice. A popular twist on Internet-based philanthropy is the use of peer-to-peer lending for charitable purposes. Kiva pioneered this concept in 2005, offering the first web-based service to publish individual loan profiles for funding. The low cost and nearly instantaneous sharing of ideas, knowledge, and skills have made collaborative work dramatically easier, with the help of collaborative software, which allow groups to easily form, cheaply communicate, and share ideas. An example of collaborative software is the free software movement, which has produced, among other things, Linux, Mozilla Firefox, and OpenOffice.org (later forked into LibreOffice).[citation needed] Content management systems allow collaborating teams to work on shared sets of documents simultaneously without accidentally destroying each other's work.[citation needed] The internet also allows for cloud computing, virtual private networks, remote desktops, and remote work.[citation needed] The online disinhibition effect describes the tendency of many individuals to behave more stridently or offensively online than they would in person. A significant number of feminist women have been the target of various forms of harassment, including insults and hate speech, to, in extreme cases, rape and death threats, in response to posts they have made on social media. Social media companies have been criticized in the past for not doing enough to aid victims of online abuse. Children also face dangers online such as cyberbullying and approaches by sexual predators, who sometimes pose as children themselves. Due to naivety, they may also post personal information about themselves online, which could put them or their families at risk unless warned not to do so. Many parents choose to enable Internet filtering or supervise their children's online activities in an attempt to protect their children from pornography or violent content on the Internet. The most popular social networking services commonly forbid users under the age of 13. However, these policies can be circumvented by registering an account with a false birth date, and a significant number of children aged under 13 join such sites.[citation needed] Social networking services for younger children, which claim to provide better levels of protection for children, also exist. Internet usage has been correlated to users' loneliness. Lonely people tend to use the Internet as an outlet for their feelings and to share their stories with others, such as in the "I am lonely will anyone speak to me" thread.[citation needed] Cyberslacking can become a drain on corporate resources; employees spend a significant amount of time surfing the Web while at work. Internet addiction disorder is excessive computer use that interferes with daily life. Nicholas G. Carr believes that Internet use has other effects on individuals, for instance improving skills of scan-reading and interfering with the deep thinking that leads to true creativity. Electronic business encompasses business processes spanning the entire value chain: purchasing, supply chain management, marketing, sales, customer service, and business relationship. E-commerce seeks to add revenue streams using the Internet to build and enhance relationships with clients and partners. According to International Data Corporation, the size of worldwide e-commerce, when global business-to-business and -consumer transactions are combined, equate to $16 trillion in 2013. A report by Oxford Economics added those two together to estimate the total size of the digital economy at $20.4 trillion, equivalent to roughly 13.8% of global sales. While much has been written of the economic advantages of Internet-enabled commerce, there is also evidence that some aspects of the Internet such as maps and location-aware services may serve to reinforce economic inequality and the digital divide. Electronic commerce may be responsible for consolidation and the decline of mom-and-pop, brick and mortar businesses resulting in increases in income inequality. A 2013 Institute for Local Self-Reliance report states that brick-and-mortar retailers employ 47 people for every $10 million in sales, while Amazon employs only 14. Similarly, the 700-employee room rental start-up Airbnb was valued at $10 billion in 2014, about half as much as Hilton Worldwide, which employs 152,000 people. At that time, Uber employed 1,000 full-time employees and was valued at $18.2 billion, about the same valuation as Avis Rent a Car and The Hertz Corporation combined, which together employed almost 60,000 people. Advertising on popular web pages can be lucrative, and e-commerce. Online advertising is a form of marketing and advertising which uses the Internet to deliver promotional marketing messages to consumers. It includes email marketing, search engine marketing (SEM), social media marketing, many types of display advertising (including web banner advertising), and mobile advertising. In 2011, Internet advertising revenues in the United States surpassed those of cable television and nearly exceeded those of broadcast television.: 19 Many common online advertising practices are controversial and increasingly subject to regulation. The Internet has achieved new relevance as a political tool. The presidential campaign of Howard Dean in 2004 in the United States was notable for its success in soliciting donation via the Internet. Many political groups use the Internet to achieve a new method of organizing for carrying out their mission, having given rise to Internet activism. Social media websites, such as Facebook and Twitter, helped people organize the Arab Spring, by helping activists organize protests, communicate grievances, and disseminate information. Many have understood the Internet as an extension of the Habermasian notion of the public sphere, observing how network communication technologies provide something like a global civic forum. However, incidents of politically motivated Internet censorship have now been recorded in many countries, including western democracies. E-government is the use of technological communications devices, such as the Internet, to provide public services to citizens and other persons in a country or region. E-government offers opportunities for more direct and convenient citizen access to government and for government provision of services directly to citizens. Cybersectarianism is a new organizational form that involves: highly dispersed small groups of practitioners that may remain largely anonymous within the larger social context and operate in relative secrecy, while still linked remotely to a larger network of believers who share a set of practices and texts, and often a common devotion to a particular leader. Overseas supporters provide funding and support; domestic practitioners distribute tracts, participate in acts of resistance, and share information on the internal situation with outsiders. Collectively, members and practitioners of such sects construct viable virtual communities of faith, exchanging personal testimonies and engaging in the collective study via email, online chat rooms, and web-based message boards. In particular, the British government has raised concerns about the prospect of young British Muslims being indoctrinated into Islamic extremism by material on the Internet, being persuaded to join terrorist groups such as the so-called "Islamic State", and then potentially committing acts of terrorism on returning to Britain after fighting in Syria or Iraq.[citation needed] Applications and services The Internet carries many applications and services, most prominently the World Wide Web, including social media, electronic mail, mobile applications, multiplayer online games, Internet telephony, file sharing, and streaming media services. The World Wide Web is a global collection of documents, images, multimedia, applications, and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs), which provide a global system of named references. URIs symbolically identify services, web servers, databases, and the documents and resources that they can provide. HyperText Transfer Protocol (HTTP) is the main access protocol of the World Wide Web. Web services also use HTTP for communication between software systems for information transfer, sharing and exchanging business data and logistics and is one of many languages or protocols that can be used for communication on the Internet. World Wide Web browser software, such as Microsoft Edge, Mozilla Firefox, Opera, Apple's Safari, and Google Chrome, enable users to navigate from one web page to another via the hyperlinks embedded in the documents. These documents may also contain computer data, including graphics, sounds, text, video, multimedia and interactive content. Client-side scripts can include animations, games, office applications and scientific demonstrations. Email is an important communications service available via the Internet. The concept of sending electronic text messages between parties, analogous to mailing letters or memos, predates the creation of the Internet. Internet telephony is a common communications service realized with the Internet. The name of the principal internetworking protocol, the Internet Protocol, lends its name to voice over Internet Protocol (VoIP).[citation needed] VoIP systems now dominate many markets, being as easy and convenient as a traditional telephone, while having substantial cost savings, especially over long distances. File sharing is the practice of transferring large amounts of data in the form of computer files across the Internet, for example via file servers. The load of bulk downloads to many users can be eased by the use of "mirror" servers or peer-to-peer networks. Access to the file may be controlled by user authentication, the transit of the file over the Internet may be obscured by encryption, and money may change hands for access to the file. The price can be paid by the remote charging of funds from, for example, a credit card whose details are also passed—usually fully encrypted—across the Internet. The origin and authenticity of the file received may be checked by a digital signature. Governance The Internet is a global network that comprises many voluntarily interconnected autonomous networks. It operates without a central governing body. The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. While the hardware components in the Internet infrastructure can often be used to support other software systems, it is the design and the standardization process of the software that characterizes the Internet and provides the foundation for its scalability and success. The responsibility for the architectural design of the Internet software systems has been assumed by the IETF. The IETF conducts standard-setting work groups, open to any individual, about the various aspects of Internet architecture. The resulting contributions and standards are published as Request for Comments (RFC) documents on the IETF web site. The principal methods of networking that enable the Internet are contained in specially designated RFCs that constitute the Internet Standards. Other less rigorous documents are simply informative, experimental, or historical, or document the best current practices when implementing Internet technologies. To maintain interoperability, the principal name spaces of the Internet are administered by the Internet Corporation for Assigned Names and Numbers (ICANN). ICANN is governed by an international board of directors drawn from across the Internet technical, business, academic, and other non-commercial communities. The organization coordinates the assignment of unique identifiers for use on the Internet, including domain names, IP addresses, application port numbers in the transport protocols, and many other parameters. Globally unified name spaces are essential for maintaining the global reach of the Internet. This role of ICANN distinguishes it as perhaps the only central coordinating body for the global Internet. The National Telecommunications and Information Administration, an agency of the United States Department of Commerce, had final approval over changes to the DNS root zone until the IANA stewardship transition on 1 October 2016. Regional Internet registries (RIRs) were established for five regions of the world to assign IP address blocks and other Internet parameters to local registries, such as Internet service providers, from a designated pool of addresses set aside for each region:[citation needed] The Internet Society (ISOC) was founded in 1992 with a mission to "assure the open development, evolution and use of the Internet for the benefit of all people throughout the world". Its members include individuals as well as corporations, organizations, governments, and universities. Among other activities ISOC provides an administrative home for a number of less formally organized groups that are involved in developing and managing the Internet, including: the Internet Engineering Task Force (IETF), Internet Architecture Board (IAB), Internet Engineering Steering Group (IESG), Internet Research Task Force (IRTF), and Internet Research Steering Group (IRSG). On 16 November 2005, the United Nations-sponsored World Summit on the Information Society in Tunis established the Internet Governance Forum (IGF) to discuss Internet-related issues.[citation needed] Infrastructure The communications infrastructure of the Internet consists of its hardware components and a system of software layers that control various aspects of the architecture. As with any computer network, the Internet physically consists of routers, media (such as cabling and radio links), repeaters, and modems. However, as an example of internetworking, many of the network nodes are not necessarily Internet equipment per se. Internet packets are carried by other full-fledged networking protocols, with the Internet acting as a homogeneous networking standard, running across heterogeneous hardware, with the packets guided to their destinations by IP routers.[citation needed] Internet service providers (ISPs) establish worldwide connectivity between individual networks at various levels of scope. At the top of the routing hierarchy are the tier 1 networks, large telecommunication companies that exchange traffic directly with each other via very high speed fiber-optic cables and governed by peering agreements. Tier 2 and lower-level networks buy Internet transit from other providers to reach at least some parties on the global Internet, though they may also engage in peering. End-users who only access the Internet when needed to perform a function or obtain information, represent the bottom of the routing hierarchy.[citation needed] An ISP may use a single upstream provider for connectivity, or implement multihoming to achieve redundancy and load balancing. Internet exchange points are major traffic exchanges with physical connections to multiple ISPs. Large organizations, such as academic institutions, large enterprises, and governments, may perform the same function as ISPs, engaging in peering and purchasing transit on behalf of their internal networks. Research networks tend to interconnect with large subnetworks such as GEANT, GLORIAD, Internet2, and the UK's national research and education network, JANET.[citation needed] Common methods of Internet access by users include broadband over coaxial cable, fiber optics or copper wires, Wi-Fi, satellite, and cellular telephone technology.[citation needed] Grassroots efforts have led to wireless community networks. Commercial Wi-Fi services that cover large areas are available in many cities, such as New York, London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and Pittsburgh. Most servers that provide internet services are today hosted in data centers, and content is often accessed through high-performance content delivery networks. Colocation centers often host private peering connections between their customers, internet transit providers, cloud providers, meet-me rooms for connecting customers together, Internet exchange points, and landing points and terminal equipment for fiber optic submarine communication cables, connecting the internet. Internet Protocol Suite The Internet standards describe a framework known as the Internet protocol suite (also called TCP/IP, based on the first two components.) This is a suite of protocols that are ordered into a set of four conceptional layers by the scope of their operation, originally documented in RFC 1122 and RFC 1123:[citation needed] The most prominent component of the Internet model is the Internet Protocol. IP enables internetworking, essentially establishing the Internet itself. Two versions of the Internet Protocol exist, IPv4 and IPv6.[citation needed] Aside from the complex array of physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts (e.g., peering agreements), and by technical specifications or protocols that describe the exchange of data over the network.[citation needed] For locating individual computers on the network, the Internet provides IP addresses. IP addresses are used by the Internet infrastructure to direct internet packets to their destinations. They consist of fixed-length numbers, which are found within the packet. IP addresses are generally assigned to equipment either automatically via Dynamic Host Configuration Protocol, or are configured.[citation needed] Domain Name Systems convert user-inputted domain names (e.g. "en.wikipedia.org") into IP addresses.[citation needed] Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. IPv4 is the initial version used on the first generation of the Internet and is still in dominant use. It was designed in 1981 to address up to ≈4.3 billion (109) hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion, which entered its final stage in 2011, when the global IPv4 address allocation pool was exhausted. Because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP IPv6, was developed in the mid-1990s, which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 uses 128 bits for the IP address and was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s and is currently in growing deployment around the world, since Internet address registries began to urge all resource managers to plan rapid adoption and conversion. By design, IPv6 is not directly interoperable with IPv4. Instead, it establishes a parallel version of the Internet not directly accessible with IPv4 software. Thus, translation facilities exist for internetworking, and some nodes have duplicate networking software for both networks. Essentially all modern computer operating systems support both versions of the Internet Protocol.[citation needed] Network infrastructure, however, has been lagging in this development.[citation needed] A subnet or subnetwork is a logical subdivision of an IP network.: 1, 16 Computers that belong to a subnet are addressed with an identical most-significant bit-group in their IP addresses. This results in the logical division of an IP address into two fields, the network number or routing prefix and the rest field or host identifier. The rest field is an identifier for a specific host or network interface.[citation needed] The routing prefix may be expressed in Classless Inter-Domain Routing (CIDR) notation written as the first address of a network, followed by a slash character (/), and ending with the bit-length of the prefix. For example, 198.51.100.0/24 is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range 198.51.100.0 to 198.51.100.255 belong to this network. The IPv6 address specification 2001:db8::/32 is a large address block with 296 addresses, having a 32-bit routing prefix.[citation needed] For IPv4, a network may also be characterized by its subnet mask or netmask, which is the bitmask that when applied by a bitwise AND operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in dot-decimal notation like an address. For example, 255.255.255.0 is the subnet mask for the prefix 198.51.100.0/24.[citation needed] Computers and routers use routing tables in their operating system to forward IP packets to reach a node on a different subnetwork. Routing tables are maintained by manual configuration or automatically by routing protocols. End-nodes typically use a default route that points toward an ISP providing transit, while ISP routers use the Border Gateway Protocol to establish the most efficient routing across the complex connections of the global Internet.[citation needed] The default gateway is the node that serves as the forwarding host (router) to other networks when no other route specification matches the destination IP address of a packet. Security Internet resources, hardware, and software components are the target of criminal or malicious attempts to gain unauthorized control to cause interruptions, commit fraud, engage in blackmail or access private information. Malware is malicious software used and distributed via the Internet. It includes computer viruses which are copied with the help of humans, computer worms which copy themselves automatically, software for denial of service attacks, ransomware, botnets, and spyware that reports on the activity and typing of users.[citation needed] Usually, these activities constitute cybercrime. Defense theorists have also speculated about the possibilities of hackers using cyber warfare using similar methods on a large scale. Malware poses serious problems to individuals and businesses on the Internet. According to Symantec's 2018 Internet Security Threat Report (ISTR), malware variants number has increased to 669,947,865 in 2017, which is twice as many malware variants as in 2016. Cybercrime, which includes malware attacks as well as other crimes committed by computer, was predicted to cost the world economy US$6 trillion in 2021, and is increasing at a rate of 15% per year. Since 2021, malware has been designed to target computer systems that run critical infrastructure such as the electricity distribution network. Malware can be designed to evade antivirus software detection algorithms. The vast majority of computer surveillance involves the monitoring of data and traffic on the Internet. In the United States for example, under the Communications Assistance For Law Enforcement Act, all phone calls and broadband Internet traffic (emails, web traffic, instant messaging, etc.) are required to be available for unimpeded real-time monitoring by Federal law enforcement agencies. Under the Act, all U.S. telecommunications providers are required to install packet sniffing technology to allow Federal law enforcement and intelligence agencies to intercept all of their customers' broadband Internet and VoIP traffic.[d] The large amount of data gathered from packet capture requires surveillance software that filters and reports relevant information, such as the use of certain words or phrases, the access to certain types of web sites, or communicating via email or chat with certain parties. Agencies, such as the Information Awareness Office, NSA, GCHQ and the FBI, spend billions of dollars per year to develop, purchase, implement, and operate systems for interception and analysis of data. Similar systems are operated by Iranian secret police to identify and suppress dissidents. The required hardware and software were allegedly installed by German Siemens AG and Finnish Nokia. Some governments, such as those of Myanmar, Iran, North Korea, Mainland China, Saudi Arabia and the United Arab Emirates, restrict access to content on the Internet within their territories, especially to political and religious content, with domain name and keyword filters. In Norway, Denmark, Finland, and Sweden, major Internet service providers have voluntarily agreed to restrict access to sites listed by authorities. While this list of forbidden resources is supposed to contain only known child pornography sites, the content of the list is secret. Many countries, including the United States, have enacted laws against the possession or distribution of certain material, such as child pornography, via the Internet but do not mandate filter software. Many free or commercially available software programs, called content-control software are available to users to block offensive specific on individual computers or networks in order to limit access by children to pornographic material or depiction of violence.[citation needed] Performance As the Internet is a heterogeneous network, its physical characteristics, including, for example the data transfer rates of connections, vary widely. It exhibits emergent phenomena that depend on its large-scale organization. PB per monthYear020,00040,00060,00080,000100,000120,000140,000199019952000200520102015Petabytes per monthGlobal Internet Traffic Volume The volume of Internet traffic is difficult to measure because no single point of measurement exists in the multi-tiered, non-hierarchical topology. Traffic data may be estimated from the aggregate volume through the peering points of the Tier 1 network providers, but traffic that stays local in large provider networks may not be accounted for.[citation needed] An Internet blackout or outage can be caused by local signaling interruptions. Disruptions of submarine communications cables may cause blackouts or slowdowns to large areas, such as in the 2008 submarine cable disruption. Less-developed countries are more vulnerable due to the small number of high-capacity links. Land cables are also vulnerable, as in 2011 when a woman digging for scrap metal severed most connectivity for the nation of Armenia. Internet blackouts affecting almost entire countries can be achieved by governments as a form of Internet censorship, as in the blockage of the Internet in Egypt, whereby approximately 93% of networks were without access in 2011 in an attempt to stop mobilization for anti-government protests. Estimates of the Internet's electricity usage have been the subject of controversy, according to a 2014 peer-reviewed research paper that found claims differing by a factor of 20,000 published in the literature during the preceding decade, ranging from 0.0064 kilowatt hours per gigabyte transferred (kWh/GB) to 136 kWh/GB. The researchers attributed these discrepancies mainly to the year of reference (i.e. whether efficiency gains over time had been taken into account) and to whether "end devices such as personal computers and servers are included" in the analysis. In 2011, academic researchers estimated the overall energy used by the Internet to be between 170 and 307 GW, less than two percent of the energy used by humanity. This estimate included the energy needed to build, operate, and periodically replace the estimated 750 million laptops, a billion smart phones and 100 million servers worldwide as well as the energy that routers, cell towers, optical switches, Wi-Fi transmitters and cloud storage devices use when transmitting Internet traffic. According to a non-peer-reviewed study published in 2018 by The Shift Project (a French think tank funded by corporate sponsors), nearly 4% of global CO2 emissions could be attributed to global data transfer and the necessary infrastructure. The study also said that online video streaming alone accounted for 60% of this data transfer and therefore contributed to over 300 million tons of CO2 emission per year, and argued for new "digital sobriety" regulations restricting the use and size of video files. See also Notes References Sources Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Gamefan] | [TOKENS: 1773] |
Contents GameFan GameFan (originally known as Diehard GameFan) was a publication started by Tim Lindquist, Greg Off, George Weising, and Dave Halverson in September 1992 that provided coverage of domestic and imported video games. It was notable for its extensive use of game screenshots in its page design, contrasting other U.S. publications at the time. The original magazine ceased publishing in December 2000. In April 2010, Halverson relaunched GameFan as a video games and film magazine. However, this relaunch was short-lived and suffered from internal conflicts and low advertising revenue. History The idea for the name GameFan came from the Japanese Sega magazine called Megafan. Although it began as an advertising supplement to sell imported video games, primarily from Japan, the small text reviews and descriptions drew attention for a lack of refinement and a sense of passion. Editor profiles featured caricatures drawn by Terry Wolfinger. The anonymized approach allowed certain editors like Dave Halverson to write multiple reviews of the same game under different pseudonyms. GameFan was well known for its extensive coverage of important games and its expansive coverage of emerging interest in anime. Another major feature that separated it from other gaming magazines was the high-quality paper used to print it. GameFan's game screenshots were more colorful and accurate to in-game graphics. By 2000, the magazine had a monthly print circulation of more than 100,000. Controversy In the September 1995 issue of GameFan, an article was printed that contained several derogatory comments about Japanese people (calling them "little Jap bastards") as well as a self-degrading racial comment ("Us poor white trash from So CA"). The text took the place of one of the paragraphs of one of the sports games reviews. The article discussed a Namco combat flight simulator, Ace Combat, rather than College Football '96 (which was the topic of the article) and was poorly written. GameFan's official explanation was that a rogue employee had sabotaged the magazine in order to alienate its Japanese audience and fan base. However, later reports indicated that it was actually filler text that someone had neglected to remove, and the entire incident was an internal joke that accidentally got printed. An apology (dated August 24, 1995) was published in DieHard GameFan's October 1995 issue in both English and Japanese. The Adventures of Monitaur The magazine included a comic strip, The Adventures of Monitaur, an anime-derived series. Although the title character Monitaur was only drawn for the strip, the rest of the magazine's staff personae appeared as characters. Monitaur's main storylines were his struggles against The Blowmeister, who represented the leadership of rival magazines such as Electronic Gaming Monthly. In 1994, GameFan and two new startups, known as Dark Moon Productions and Dark Moon Comics, entered into an agreement to launch a Monitor comic book series, and at that time discussions were underway to make a full-length animated movie to be produced by Dark Moon Productions Inc and DMP Multi-media, a sister company founded by Andrew Spencer and Gary Tucker. Golden Megawards The winners of GameFan's annual Golden Megawards were chosen by editors. Related publications GameFan's original editor-in-chief, Dave Halverson, went on to publish Gamers' Republic, and then Play Magazine (an American video-gaming magazine, not to be confused with the English publication of the same name), consisting mostly of former GameFan and Gamers' Republic staff members. Gamers' Republic had a run of 35 issues and ceased publication in July 2001 when the dot-com bubble burst. The Play had a more successful run of 97 issues until the publishing company filed for bankruptcy. Tim Lindquist, along with several other members of the original GameFan team, launched a new magazine, Hardcore Gamer. They also began developing strategy guides as a part of their publishing company, DoubleJump Books (later renamed OnionBat Books). The magazine had a run of 36 issues before it began focusing exclusively on its website. The DieHard GameFan name was resurrected by Alex Lucard as a website, Diehard GameFAN, with Halverson's blessing. While the site covers major game releases, the site also reviews indie games, much like the original magazine. 2010 relaunch After the bankruptcy of Fusion Publishing and the closure of Play, Dave Halverson began work on a relaunch of GameFan. The magazine returned to newsstands in April 2010, headed by Halverson and a few key staffers from Play with Rob Duenas serving as the new art director. It was available in both print and digital formats, the latter of which was sold directly through GameFan's online shop. The first two issues of the relaunched GameFan featured a section titled MovieFan, which covered movies, anime, and comics. The first two-thirds of the magazine was devoted to GameFan, and then readers would have to turn the magazine upside down in order to read the MovieFan magazine. As of issue 3, the MovieFan portion of the magazine was discontinued, but later issues still featured anime and comic reviews similar to Play. In its second and final issue, MovieFan conducted one of the last known interviews with the late filmmaker Satoshi Kon. The first five issues of the magazine were released on a consistent bi-monthly schedule. However, problems occurred with the magazine's development due to issues with advertising revenue, causing the sixth issue to be released in August 2011, eight months after issue 5, and with an entirely new editing team, headed by newcomer James Bacon. Issue 7 was assembled by only three people - editor-in-chief Dave Halverson, art director and graphic designer Rob Duenas, and managing editor James Bacon - and was released in December 2011. Soon thereafter Duenas resigned. The reason for his departure was due to an overwhelming workload; Duenas stated that he worked "20 hours a day for two weeks straight and [he was] still short cover art". Despite the stressful working conditions, Duenas harbored no ill will towards Halverson or the magazine, stating that he would have still been willing to contribute with cover illustrations or provide assistance with layouts. Soon after Duenas' departure, Bacon left for reasons unstated. A press release was issued on April 18, 2012, highlighting the supposed future of Paper Planet brands: GameFan and Girls of Gaming. The company planned on increasing its online presence through app development for mobile devices as well as a new GameFan TV online channel. None of these plans would come to fruition except the creation of a YouTube channel. Former Destructoid editor Wesley Ruscher was named the magazine's new editor-in-chief but resigned shortly after the release of issue 8, stating that it "lacked the necessities to keep food in [his] belly and a roof over [his] head." As of June 2013, GameFan's web presence had been in a mostly inactive state for about a year. Issue 9 was finally made available in February 2013 after missing the holiday 2012 release. This issue was only worked on by two people, Dave Halverson and Greg Orlando. Issues 8 and 9 were only available in a digital format. GameFan would later go on a two-year hiatus, returning in 2015 with a redesigned magazine and website. In February 2015, GameFan simultaneously released issue 10 digitally and on newsstands. The digital version was freely released on Magzter with the use of a promotional code. The magazine went through a complete overhaul, simplifying its layouts and design, most likely in order to have the magazines completed on schedule. The size of the print magazine is significantly smaller compared to previous issues. In addition, the GameFan mascot, Monitaur, and logo were redesigned. On May 6, 2015, GameFan announced a partnership with Destructoid to help promote the GameFan brand with collaborations and free subscription offers. The initial plan was to bring back the dual-cover format from the first two issues, but instead of a MovieFan portion, it would be exclusive content created by Destructoid for the magazine. According to GameFan's official Facebook page, the deal with Destructoid would have allowed for the magazine to be released on a monthly schedule. However, the deal with Destructoid resulted in only one issue of the GameFan/Destructoid magazine ever being released.[citation needed] As of January 2019, there have been no new updates regarding GameFan's overall status. References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Ijlil_al-Shamaliyya] | [TOKENS: 950] |
Contents Ijlil al-Shamaliyya Ijlil al-Shamaliyya (Arabic: إجليل الشمالية Ijlīl aš-Šamāliyya) was a Palestinian Arab village in the Jaffa Subdistrict. Established in the 19th century, it was founded by Bani Sa'b tribesmen from the Qalqiliya area and migrants from Egypt. It was depopulated during the 1947–1948 Civil War in Mandatory Palestine on April 3, 1948. Location Ijlil al-Shamaliyya, (meaning "Northern Ijlil"), was located on a hilltop, 15 km (9 mi) northeast of Jaffa, and about 100 meters north of its sister village, Ijlil al-Qibliyya ("Southern Jilil"). History Ijlil was one of four villages founded in the 18th century, near the coast north of the Yarkon River (along with the villages of Al-Shaykh Muwannis, Al-Haram, and Umm Khalid). According to historian Roy Marom, the establishment of Ijlil "demonstrates that the expansion of settlement in the southern Sharon was the result of the internal expansion of the core settlement by residents of the mountainous highlands of Samaria, and not by Egyptian ‘penetrators’ as previously claimed." In June 1870, the French explorer Victor Guérin visited both villages. He described them as one unit called Edjlil, situated on a hill and divided into two districts. Together, they had 380 inhabitants. The houses were built of rammed earth or with different small aggregates mixed in with kneaded and dried silt. In 1870/1871 (1288 AH), an Ottoman census listed Ijlil in the nahiya (sub-district) of Bani Sa'b. In 1882, the PEF's Survey of Western Palestine described the two villages, named El Jelil, as "a mud village, with a well to the south and a second to the north. [..] A small olive-grove exists to the south-east." In the 1922 census of Palestine conducted by the British Mandate authorities, the twin villages of Ijlil (spelled Jelil) had a population of 154, all Muslims, increasing by the 1931 census to 305, still all Muslim. In 1943 Glil Yam was founded on what was traditionally village land, to the east of the village site. In the 1945 statistics the population of Ijlil al-Shamaliyya consisted of 190 Muslims and the land area was 2,450 dunams of land, according to an official land and population survey. Of this land, 183 dunams were designated for citrus and bananas, 13 for plantations and irrigable land, 1,574 for cereals, while seven dunams were built-up areas. Also in 1945, a school was founded in the village and shared with Ijlil al-Qibliyya. It had 64 students in its first year. The village also had a mosque and several small shops. In December 1947 and January 1948 the leaders of al-Shaykh Muwannis, al-Mas'udiyya, al-Jammasin al-Sharqi, al-Jammasin al-Gharbi, and the mukhtars of 'Arab Abu Kishk and the two Ijlil-villages met with Haganah representatives in Petah Tikva. These villages wanted peace, and promised not to harbor any Arab Liberation Army soldiers or local Arab militia. They further promised that, in the case they were not able to keep them out alone, they were to call on Haganah for help. By mid-March 1948, the Alexandroni Brigade had imposed isolation, dubbed "quarantine", of al-Shaykh Muwannis, 'Arab Abu Kishk and the two Ijlil-villages. However, on 12 March, the LHI kidnapped five village notables from al-Shaykh Muwannis. This undermined the villagers' trust in former agreements, and many left. The people of the two Ijlil-villages also left, after asking Jewish neighbours to look after their property. In 1992, the historian Walid Khalidi found that the place was difficult to identify with precision as it was part of a large garbage dump. References Bibliography External links |
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[SOURCE: https://en.wikipedia.org/wiki/Internet_video] | [TOKENS: 1642] |
Contents Internet video Internet video (also known as online video) is digital video that is distributed over the internet. Internet video exists in several formats, the most notable being MPEG-4i AVC, AVCHD, FLV, and MP4. Watching videos has long fascinated audiences, and this interest has driven the development and advancement of video technology. From traditional television sets to personal computers, tablets and smartphones, video has evolved overtime. Internet connectivity has further increased accessibility and convenience, giving rise to a wide range of online video platforms that provide streaming or downloadable content. Some of these platforms include YouTube, TED, Netflix, Hulu and Apple TV. There are several online video hosting services, including YouTube. In recent years, the platform of internet video has been used to stream live events. As a result of the popularity of online video, notable events like the 2012 U.S. presidential debates have been streamed live on the internet. Additionally, internet video has played an important role in the music industry as a medium to watch music videos and increase exposure of songs. Video file formats Practical online video streaming was only made possible with advances in data compression, due to the impractically high bandwidth requirements of uncompressed video. Raw digital video requires a bandwidth of 168 Mbit/s for SD video, and over 1 Gbit/s for FHD video. H.264/MPEG-4 AVC is the most widely used video coding format on the Internet. It was developed in 2003 by a number of organizations. AVCHD, or Advanced Video Coding High Definition, uses one of the more efficient video coding formats. It was announced in May 2006 and since then has grown into a high-quality video format that can compete with other professional forms of media. The AVCHD is geared towards consumer shooters; this is largely because the AVCHD format capitalizes on the H.264/MPEG-4 video that is able to compress video to smaller sizes in order to allow more video to be stored in the same storage capacity. Flash Video (FLV) is video encoded by Adobe Flash software in order to play within the Adobe Flash Player. Popular in the past, and used by several video sites, including YouTube, the Adobe Flash Player has been replaced by HTML5 and this format has been abandoned. MPEG-4 is known as a sharing format for the internet. In recent years an increasing number of camcorder and cameras began employ it. Moreover, YouTube recommends using the MP4 Format (Although it accepts multiple formats, YouTube either converts them to .flv or .mp4 files). Apple is another company that has backed MP4 by using it in its QuickTime player. YouTube YouTube was founded in 2005 by Chad Hurley, Steve Chen, and Jawed Karim. The first video on the platform was "Me at the zoo" uploaded by Karim on the first YouTube channel, jawed, in April 2005. In October 2005, Nike became the first major company to embrace YouTube as a promotional platform. They were the first company to do this and since then YouTube has provided a means of displaying internet video in order to help companies promote their products. Google purchased YouTube for $1.65 billion in October 2006 and since then it has developed it even further. Since then, it has become the most popular website for watching internet video. For example, the hours of video watched per month on YouTube totaled 6 billion. As of 2014, there were one billion unique users to YouTube each month. According to Nielsen, YouTube reaches more U.S. adults aged 18–34 years old than any cable network. Other video platforms Aside from YouTube, there are several other internet video platforms, which despite being less popular, are still used by many. Live streaming Live streaming is another important aspect of internet video. This is when particular events are streamed using a live form of internet video. A key example of this is that in 2008 and 2012, during the presidential election, the debates between the two candidates were live-streamed on YouTube. Live streaming has also been used as a means of promoting exposure for a particular product or business. This is largely because platforms such as YouTube provide a cheap, and usually free, means to access millions of users. Whether that be potential customers on laptops, smartphones, tablets, and smart TVs. A study conducted by SocialMediaExaminer supports this hypothesis using YouTube as a particular example. A sign of the growth of importance of internet video live streaming refers to the change in business model of the World Wrestling Entertainment (WWE). Previously the WWE's business model involved receiving huge numbers of pay-per-view buys for special events hosted once per month and charging approx. $44.95 (Dependent on retailer) for each. However, in February 2014 they launched a 24/7 streaming network charging $9.99 per month in order to get access to every "special event". This shows that one of the largest entertainment companies was willing to adopt to a live streaming/internet video model in order to support their business. Many other companies such as BBC (with iPlayer), ITV (with ITV Player) and Channel 4 (with 4oD) have made use of internet video to allow users to livestream content, or watch on demand later. Controversy Both live streaming and internet videos have faced controversy in recent years, largely because it is extremely difficult to access all the live-streams which show particular events. This infringes on the issue of copyright. Rights-holders face the challenge of content, which includes audio, TV shows and sporting events, being streamed live to the public. As a result, streaming website Justin.TV partnered with content matching service Vobile in order to filter out infringing material. Another example of a copyright issue which occurred to online streaming was when uStream were sued by a boxing promoter in August 2009 for allowing 2,337 users to view a broadcast of the fight Roy Jones Jr. vs Omar Sheika. YouTube has also faced issues surrounding copyright. For example, in December 2013, many YouTubers who published footage of video games for either review or tutorial purposes were punished and crippled by copyright claims. In the past, YouTube has also faced issues with the music industry over users publishing videos without the permission of the music industry. The issues can be seen by the fact that since 2007, YouTube has paid out one billion dollars to copyright holders. Saying that, the formation of Vevo has aided YouTube in terms of issues with the music industry by allowing artists/labels to get a share of revenue. The importance of video in the music industry The growth of internet video has provided a platform to help elevate the music industry. This has most particularly been seen through the platform of YouTube. Chris Maxcy, YouTube's partner development director stated that “YouTube is the ideal place for labels to promote music and for fans to discover new artists and old favourites”. Moreover, Rio Caraeff, who heads up Universal's digital group described YouTube as a “revenue stream, a commercial business. It's growing tremendously. It's up almost 80 percent for us year-over-year in the U.S. in terms of our revenue from this category”. In addition, an article published in 2011, believes that YouTube has changed the music industry citing three ways; YouTube allows people to listen to the native music of India, for example, and other regions which would otherwise be difficult to discover. Brittany Wong also believes that YouTube allows people to get discovered. This is largely because it allows anybody to post an online video for the world to see. Finally, it mentions that the convenience of the platform allows many people to listen to music, which has increased potential audiences. Mike Masnik, the CEO and founder of Techdirt, recognized the importance of YouTube in the music industry. In this article he recognizes the potential ability of YouTube in order to allow musicians to increase exposure, and record labels to make money. However, they were naïve and did not fully embrace it. See also References |
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Contents Elon Musk Elon Reeve Musk (/ˈiːlɒn/ EE-lon; born June 28, 1971) is a businessman and entrepreneur known for his leadership of Tesla, SpaceX, Twitter, and xAI. Musk has been the wealthiest person in the world since 2025; as of February 2026,[update] Forbes estimates his net worth to be around US$852 billion. Born into a wealthy family in Pretoria, South Africa, Musk emigrated in 1989 to Canada; he has Canadian citizenship since his mother was born there. He received bachelor's degrees in 1997 from the University of Pennsylvania before moving to California to pursue business ventures. In 1995, Musk co-founded the software company Zip2. Following its sale in 1999, he co-founded X.com, an online payment company that later merged to form PayPal, which was acquired by eBay in 2002. Musk also became an American citizen in 2002. In 2002, Musk founded the space technology company SpaceX, becoming its CEO and chief engineer; the company has since led innovations in reusable rockets and commercial spaceflight. Musk joined the automaker Tesla as an early investor in 2004 and became its CEO and product architect in 2008; it has since become a leader in electric vehicles. In 2015, he co-founded OpenAI to advance artificial intelligence (AI) research, but later left; growing discontent with the organization's direction and their leadership in the AI boom in the 2020s led him to establish xAI, which became a subsidiary of SpaceX in 2026. In 2022, he acquired the social network Twitter, implementing significant changes, and rebranding it as X in 2023. His other businesses include the neurotechnology company Neuralink, which he co-founded in 2016, and the tunneling company the Boring Company, which he founded in 2017. In November 2025, a Tesla pay package worth $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Musk was the largest donor in the 2024 U.S. presidential election, where he supported Donald Trump. After Trump was inaugurated as president in early 2025, Musk served as Senior Advisor to the President and as the de facto head of the Department of Government Efficiency (DOGE). After a public feud with Trump, Musk left the Trump administration and returned to managing his companies. Musk is a supporter of global far-right figures, causes, and political parties. His political activities, views, and statements have made him a polarizing figure. Musk has been criticized for COVID-19 misinformation, promoting conspiracy theories, and affirming antisemitic, racist, and transphobic comments. His acquisition of Twitter was controversial due to a subsequent increase in hate speech and the spread of misinformation on the service, following his pledge to decrease censorship. His role in the second Trump administration attracted public backlash, particularly in response to DOGE. The emails he sent to Jeffrey Epstein are included in the Epstein files, which were published between 2025–26 and became a topic of worldwide debate. Early life Elon Reeve Musk was born on June 28, 1971, in Pretoria, South Africa's administrative capital. He is of British and Pennsylvania Dutch ancestry. His mother, Maye (née Haldeman), is a model and dietitian born in Saskatchewan, Canada, and raised in South Africa. Musk therefore holds both South African and Canadian citizenship from birth. His father, Errol Musk, is a South African electromechanical engineer, pilot, sailor, consultant, emerald dealer, and property developer, who partly owned a rental lodge at Timbavati Private Nature Reserve. His maternal grandfather, Joshua N. Haldeman, who died in a plane crash when Elon was a toddler, was an American-born Canadian chiropractor, aviator and political activist in the technocracy movement who moved to South Africa in 1950. Elon has a younger brother, Kimbal, a younger sister, Tosca, and four paternal half-siblings. Musk was baptized as a child in the Anglican Church of Southern Africa. Despite both Elon and Errol previously stating that Errol was a part owner of a Zambian emerald mine, in 2023, Errol recounted that the deal he made was to receive "a portion of the emeralds produced at three small mines". Errol was elected to the Pretoria City Council as a representative of the anti-apartheid Progressive Party and has said that his children shared their father's dislike of apartheid. After his parents divorced in 1979, Elon, aged around 9, chose to live with his father because Errol Musk had an Encyclopædia Britannica and a computer. Elon later regretted his decision and became estranged from his father. Elon has recounted trips to a wilderness school that he described as a "paramilitary Lord of the Flies" where "bullying was a virtue" and children were encouraged to fight over rations. In one incident, after an altercation with a fellow pupil, Elon was thrown down concrete steps and beaten severely, leading to him being hospitalized for his injuries. Elon described his father berating him after he was discharged from the hospital. Errol denied berating Elon and claimed, "The [other] boy had just lost his father to suicide, and Elon had called him stupid. Elon had a tendency to call people stupid. How could I possibly blame that child?" Elon was an enthusiastic reader of books, and had attributed his success in part to having read The Lord of the Rings, the Foundation series, and The Hitchhiker's Guide to the Galaxy. At age ten, he developed an interest in computing and video games, teaching himself how to program from the VIC-20 user manual. At age twelve, Elon sold his BASIC-based game Blastar to PC and Office Technology magazine for approximately $500 (equivalent to $1,600 in 2025). Musk attended Waterkloof House Preparatory School, Bryanston High School, and then Pretoria Boys High School, where he graduated. Musk was a decent but unexceptional student, earning a 61/100 in Afrikaans and a B on his senior math certification. Musk applied for a Canadian passport through his Canadian-born mother to avoid South Africa's mandatory military service, which would have forced him to participate in the apartheid regime, as well as to ease his path to immigration to the United States. While waiting for his application to be processed, he attended the University of Pretoria for five months. Musk arrived in Canada in June 1989, connected with a second cousin in Saskatchewan, and worked odd jobs, including at a farm and a lumber mill. In 1990, he entered Queen's University in Kingston, Ontario. Two years later, he transferred to the University of Pennsylvania, where he studied until 1995. Although Musk has said that he earned his degrees in 1995, the University of Pennsylvania did not award them until 1997 – a Bachelor of Arts in physics and a Bachelor of Science in economics from the university's Wharton School. He reportedly hosted large, ticketed house parties to help pay for tuition, and wrote a business plan for an electronic book-scanning service similar to Google Books. In 1994, Musk held two internships in Silicon Valley: one at energy storage startup Pinnacle Research Institute, which investigated electrolytic supercapacitors for energy storage, and another at Palo Alto–based startup Rocket Science Games. In 1995, he was accepted to a graduate program in materials science at Stanford University, but did not enroll. Musk decided to join the Internet boom of the 1990s, applying for a job at Netscape, to which he reportedly never received a response. The Washington Post reported that Musk lacked legal authorization to remain and work in the United States after failing to enroll at Stanford. In response, Musk said he was allowed to work at that time and that his student visa transitioned to an H1-B. According to numerous former business associates and shareholders, Musk said he was on a student visa at the time. Business career In 1995, Musk, his brother Kimbal, and Greg Kouri founded the web software company Zip2 with funding from a group of angel investors. They housed the venture at a small rented office in Palo Alto. Replying to Rolling Stone, Musk denounced the notion that they started their company with funds borrowed from Errol Musk, but in a tweet, he recognized that his father contributed 10% of a later funding round. The company developed and marketed an Internet city guide for the newspaper publishing industry, with maps, directions, and yellow pages. According to Musk, "The website was up during the day and I was coding it at night, seven days a week, all the time." To impress investors, Musk built a large plastic structure around a standard computer to create the impression that Zip2 was powered by a small supercomputer. The Musk brothers obtained contracts with The New York Times and the Chicago Tribune, and persuaded the board of directors to abandon plans for a merger with CitySearch. Musk's attempts to become CEO were thwarted by the board. Compaq acquired Zip2 for $307 million in cash in February 1999 (equivalent to $590,000,000 in 2025), and Musk received $22 million (equivalent to $43,000,000 in 2025) for his 7-percent share. In 1999, Musk co-founded X.com, an online financial services and e-mail payment company. The startup was one of the first federally insured online banks, and, in its initial months of operation, over 200,000 customers joined the service. The company's investors regarded Musk as inexperienced and replaced him with Intuit CEO Bill Harris by the end of the year. The following year, X.com merged with online bank Confinity to avoid competition. Founded by Max Levchin and Peter Thiel, Confinity had its own money-transfer service, PayPal, which was more popular than X.com's service. Within the merged company, Musk returned as CEO. Musk's preference for Microsoft software over Unix created a rift in the company and caused Thiel to resign. Due to resulting technological issues and lack of a cohesive business model, the board ousted Musk and replaced him with Thiel in 2000.[b] Under Thiel, the company focused on the PayPal service and was renamed PayPal in 2001. In 2002, PayPal was acquired by eBay for $1.5 billion (equivalent to $2,700,000,000 in 2025) in stock, of which Musk—the largest shareholder with 11.72% of shares—received $175.8 million (equivalent to $320,000,000 in 2025). In 2017, Musk purchased the domain X.com from PayPal for an undisclosed amount, stating that it had sentimental value. In 2001, Musk became involved with the nonprofit Mars Society and discussed funding plans to place a growth-chamber for plants on Mars. Seeking a way to launch the greenhouse payloads into space, Musk made two unsuccessful trips to Moscow to purchase intercontinental ballistic missiles (ICBMs) from Russian companies NPO Lavochkin and Kosmotras. Musk instead decided to start a company to build affordable rockets. With $100 million of his early fortune, (equivalent to $180,000,000 in 2025) Musk founded SpaceX in May 2002 and became the company's CEO and Chief Engineer. SpaceX attempted its first launch of the Falcon 1 rocket in 2006. Although the rocket failed to reach Earth orbit, it was awarded a Commercial Orbital Transportation Services program contract from NASA, then led by Mike Griffin. After two more failed attempts that nearly caused Musk to go bankrupt, SpaceX succeeded in launching the Falcon 1 into orbit in 2008. Later that year, SpaceX received a $1.6 billion NASA contract (equivalent to $2,400,000,000 in 2025) for Falcon 9-launched Dragon spacecraft flights to the International Space Station (ISS), replacing the Space Shuttle after its 2011 retirement. In 2012, the Dragon vehicle docked with the ISS, a first for a commercial spacecraft. Working towards its goal of reusable rockets, in 2015 SpaceX successfully landed the first stage of a Falcon 9 on a land platform. Later landings were achieved on autonomous spaceport drone ships, an ocean-based recovery platform. In 2018, SpaceX launched the Falcon Heavy; the inaugural mission carried Musk's personal Tesla Roadster as a dummy payload. Since 2019, SpaceX has been developing Starship, a reusable, super heavy-lift launch vehicle intended to replace the Falcon 9 and Falcon Heavy. In 2020, SpaceX launched its first crewed flight, the Demo-2, becoming the first private company to place astronauts into orbit and dock a crewed spacecraft with the ISS. In 2024, NASA awarded SpaceX an $843 million (equivalent to $865,000,000 in 2025) contract to build a spacecraft that NASA will use to deorbit the ISS at the end of its lifespan. In 2015, SpaceX began development of the Starlink constellation of low Earth orbit satellites to provide satellite Internet access. After the launch of prototype satellites in 2018, the first large constellation was deployed in May 2019. As of May 2025[update], over 7,600 Starlink satellites are operational, comprising 65% of all operational Earth satellites. The total cost of the decade-long project to design, build, and deploy the constellation was estimated by SpaceX in 2020 to be $10 billion (equivalent to $12,000,000,000 in 2025).[c] During the Russian invasion of Ukraine, Musk provided free Starlink service to Ukraine, permitting Internet access and communication at a yearly cost to SpaceX of $400 million (equivalent to $440,000,000 in 2025). However, Musk refused to block Russian state media on Starlink. In 2023, Musk denied Ukraine's request to activate Starlink over Crimea to aid an attack against the Russian navy, citing fears of a nuclear response. Tesla, Inc., originally Tesla Motors, was incorporated in July 2003 by Martin Eberhard and Marc Tarpenning. Both men played active roles in the company's early development prior to Musk's involvement. Musk led the Series A round of investment in February 2004; he invested $6.35 million (equivalent to $11,000,000 in 2025), became the majority shareholder, and joined Tesla's board of directors as chairman. Musk took an active role within the company and oversaw Roadster product design, but was not deeply involved in day-to-day business operations. Following a series of escalating conflicts in 2007 and the 2008 financial crisis, Eberhard was ousted from the firm.[page needed] Musk assumed leadership of the company as CEO and product architect in 2008. A 2009 lawsuit settlement with Eberhard designated Musk as a Tesla co-founder, along with Tarpenning and two others. Tesla began delivery of the Roadster, an electric sports car, in 2008. With sales of about 2,500 vehicles, it was the first mass production all-electric car to use lithium-ion battery cells. Under Musk, Tesla has since launched several well-selling electric vehicles, including the four-door sedan Model S (2012), the crossover Model X (2015), the mass-market sedan Model 3 (2017), the crossover Model Y (2020), and the pickup truck Cybertruck (2023). In May 2020, Musk resigned as chairman of the board as part of the settlement of a lawsuit from the SEC over him tweeting that funding had been "secured" for potentially taking Tesla private. The company has also constructed multiple lithium-ion battery and electric vehicle factories, called Gigafactories. Since its initial public offering in 2010, Tesla stock has risen significantly; it became the most valuable carmaker in summer 2020, and it entered the S&P 500 later that year. In October 2021, it reached a market capitalization of $1 trillion (equivalent to $1,200,000,000,000 in 2025), the sixth company in U.S. history to do so. Musk provided the initial concept and financial capital for SolarCity, which his cousins Lyndon and Peter Rive founded in 2006. By 2013, SolarCity was the second largest provider of solar power systems in the United States. In 2014, Musk promoted the idea of SolarCity building an advanced production facility in Buffalo, New York, triple the size of the largest solar plant in the United States. Construction of the factory started in 2014 and was completed in 2017. It operated as a joint venture with Panasonic until early 2020. Tesla acquired SolarCity for $2 billion in 2016 (equivalent to $2,700,000,000 in 2025) and merged it with its battery unit to create Tesla Energy. The deal's announcement resulted in a more than 10% drop in Tesla's stock price; at the time, SolarCity was facing liquidity issues. Multiple shareholder groups filed a lawsuit against Musk and Tesla's directors, stating that the purchase of SolarCity was done solely to benefit Musk and came at the expense of Tesla and its shareholders. Tesla directors settled the lawsuit in January 2020, leaving Musk the sole remaining defendant. Two years later, the court ruled in Musk's favor. In 2016, Musk co-founded Neuralink, a neurotechnology startup, with an investment of $100 million. Neuralink aims to integrate the human brain with artificial intelligence (AI) by creating devices that are embedded in the brain. Such technology could enhance memory or allow the devices to communicate with software. The company also hopes to develop devices to treat neurological conditions like spinal cord injuries. In 2022, Neuralink announced that clinical trials would begin by the end of the year. In September 2023, the Food and Drug Administration approved Neuralink to initiate six-year human trials. Neuralink has conducted animal testing on macaques at the University of California, Davis. In 2021, the company released a video in which a macaque played the video game Pong via a Neuralink implant. The company's animal trials—which have caused the deaths of some monkeys—have led to claims of animal cruelty. The Physicians Committee for Responsible Medicine has alleged that Neuralink violated the Animal Welfare Act. Employees have complained that pressure from Musk to accelerate development has led to botched experiments and unnecessary animal deaths. In 2022, a federal probe was launched into possible animal welfare violations by Neuralink.[needs update] In 2017, Musk founded the Boring Company to construct tunnels; he also revealed plans for specialized, underground, high-occupancy vehicles that could travel up to 150 miles per hour (240 km/h) and thus circumvent above-ground traffic in major cities. Early in 2017, the company began discussions with regulatory bodies and initiated construction of a 30-foot (9.1 m) wide, 50-foot (15 m) long, and 15-foot (4.6 m) deep "test trench" on the premises of SpaceX's offices, as that required no permits. The Los Angeles tunnel, less than two miles (3.2 km) in length, debuted to journalists in 2018. It used Tesla Model Xs and was reported to be a rough ride while traveling at suboptimal speeds. Two tunnel projects announced in 2018, in Chicago and West Los Angeles, have been canceled. A tunnel beneath the Las Vegas Convention Center was completed in early 2021. Local officials have approved further expansions of the tunnel system. April 14, 2022 In early 2017, Musk expressed interest in buying Twitter and had questioned the platform's commitment to freedom of speech. By 2022, Musk had reached 9.2% stake in the company, making him the largest shareholder.[d] Musk later agreed to a deal that would appoint him to Twitter's board of directors and prohibit him from acquiring more than 14.9% of the company. Days later, Musk made a $43 billion offer to buy Twitter. By the end of April Musk had successfully concluded his bid for approximately $44 billion. This included approximately $12.5 billion in loans and $21 billion in equity financing. Having backtracked on his initial decision, Musk bought the company on October 27, 2022. Immediately after the acquisition, Musk fired several top Twitter executives including CEO Parag Agrawal; Musk became the CEO instead. Under Elon Musk, Twitter instituted monthly subscriptions for a "blue check", and laid off a significant portion of the company's staff. Musk lessened content moderation and hate speech also increased on the platform after his takeover. In late 2022, Musk released internal documents relating to Twitter's moderation of Hunter Biden's laptop controversy in the lead-up to the 2020 presidential election. Musk also promised to step down as CEO after a Twitter poll, and five months later, Musk stepped down as CEO and transitioned his role to executive chairman and chief technology officer (CTO). Despite Musk stepping down as CEO, X continues to struggle with challenges such as viral misinformation, hate speech, and antisemitism controversies. Musk has been accused of trying to silence some of his critics such as Twitch streamer Asmongold, who criticized him during one of his streams. Musk has been accused of removing their accounts' blue checkmarks, which hinders visibility and is considered a form of shadow banning, or suspending their accounts without justification. Other activities In August 2013, Musk announced plans for a version of a vactrain, and assigned engineers from SpaceX and Tesla to design a transport system between Greater Los Angeles and the San Francisco Bay Area, at an estimated cost of $6 billion. Later that year, Musk unveiled the concept, dubbed the Hyperloop, intended to make travel cheaper than any other mode of transport for such long distances. In December 2015, Musk co-founded OpenAI, a not-for-profit artificial intelligence (AI) research company aiming to develop artificial general intelligence, intended to be safe and beneficial to humanity. Musk pledged $1 billion of funding to the company, and initially gave $50 million. In 2018, Musk left the OpenAI board. Since 2018, OpenAI has made significant advances in machine learning. In July 2023, Musk launched the artificial intelligence company xAI, which aims to develop a generative AI program that competes with existing offerings like OpenAI's ChatGPT. Musk obtained funding from investors in SpaceX and Tesla, and xAI hired engineers from Google and OpenAI. December 16, 2022 Musk uses a private jet owned by Falcon Landing LLC, a SpaceX-linked company, and acquired a second jet in August 2020. His heavy use of the jets and the consequent fossil fuel usage have received criticism. Musk's flight usage is tracked on social media through ElonJet. In December 2022, Musk banned the ElonJet account on Twitter, and made temporary bans on the accounts of journalists that posted stories regarding the incident, including Donie O'Sullivan, Keith Olbermann, and journalists from The New York Times, The Washington Post, CNN, and The Intercept. In October 2025, Musk's company xAI launched Grokipedia, an AI-generated online encyclopedia that he promoted as an alternative to Wikipedia. Articles on Grokipedia are generated and reviewed by xAI's Grok chatbot. Media coverage and academic analysis described Grokipedia as frequently reusing Wikipedia content but framing contested political and social topics in line with Musk's own views and right-wing narratives. A study by Cornell University researchers and NBC News stated that Grokipedia cites sources that are blacklisted or considered "generally unreliable" on Wikipedia, for example, the conspiracy site Infowars and the neo-Nazi forum Stormfront. Wired, The Guardian and Time criticized Grokipedia for factual errors and for presenting Musk himself in unusually positive terms while downplaying controversies. Politics Musk is an outlier among business leaders who typically avoid partisan political advocacy. Musk was a registered independent voter when he lived in California. Historically, he has donated to both Democrats and Republicans, many of whom serve in states in which he has a vested interest. Since 2022, his political contributions have mostly supported Republicans, with his first vote for a Republican going to Mayra Flores in the 2022 Texas's 34th congressional district special election. In 2024, he started supporting international far-right political parties, activists, and causes, and has shared misinformation and numerous conspiracy theories. Since 2024, his views have been generally described as right-wing. Musk supported Barack Obama in 2008 and 2012, Hillary Clinton in 2016, Joe Biden in 2020, and Donald Trump in 2024. In the 2020 Democratic Party presidential primaries, Musk endorsed candidate Andrew Yang and expressed support for Yang's proposed universal basic income, and endorsed Kanye West's 2020 presidential campaign. In 2021, Musk publicly expressed opposition to the Build Back Better Act, a $3.5 trillion legislative package endorsed by Joe Biden that ultimately failed to pass due to unanimous opposition from congressional Republicans and several Democrats. In 2022, gave over $50 million to Citizens for Sanity, a conservative political action committee. In 2023, he supported Republican Ron DeSantis for the 2024 U.S. presidential election, giving $10 million to his campaign, and hosted DeSantis's campaign announcement on a Twitter Spaces event. From June 2023 to January 2024, Musk hosted a bipartisan set of X Spaces with Republican and Democratic candidates, including Robert F. Kennedy Jr., Vivek Ramaswamy, and Dean Phillips. In October 2025, former vice-president Kamala Harris commented that it was a mistake from the Democratic side to not invite Musk to a White House electric vehicle event organized in August 2021 and featuring executives from General Motors, Ford and Stellantis, despite Tesla being "the major American manufacturer of extraordinary innovation in this space." Fortune remarked that this was a nod to United Auto Workers and organized labor. Harris said presidents should put aside political loyalties when it came to recognizing innovation, and guessed that the non-invitation impacted Musk's perspective. Fortune noted that, at the time, Musk said, "Yeah, seems odd that Tesla wasn't invited." A month later, he criticized Biden as "not the friendliest administration." Jacob Silverman, author of the book Gilded Rage: Elon Musk and the Radicalization of Silicon Valley, said that the tech industry represented by Musk, Thiel, Andreessen and other capitalists, actually flourished under Biden, but the tech leaders chose Trump for their common ground on cultural issues. By early 2024, Musk had become a vocal and financial supporter of Donald Trump. In July 2024, minutes after the attempted assassination of Donald Trump, Musk endorsed him for president saying; "I fully endorse President Trump and hope for his rapid recovery." During the presidential campaign, Musk joined Trump on stage at a campaign rally, and during the campaign promoted conspiracy theories and falsehoods about Democrats, election fraud and immigration, in support of Trump. Musk was the largest individual donor of the 2024 election. In 2025, Musk contributed $19 million to the Wisconsin Supreme Court race, hoping to influence the state's future redistricting efforts and its regulations governing car manufacturers and dealers. In 2023, Musk said he shunned the World Economic Forum because it was boring. The organization commented that they had not invited him since 2015. He has participated in Dialog, dubbed "Tech Bilderberg" and organized by Peter Thiel and Auren Hoffman, though. Musk's international political actions and comments have come under increasing scrutiny and criticism, especially from the governments and leaders of France, Germany, Norway, Spain and the United Kingdom, particularly due to his position in the U.S. government as well as ownership of X. An NBC News analysis found he had boosted far-right political movements to cut immigration and curtail regulation of business in at least 18 countries on six continents since 2023. During his speech after the second inauguration of Donald Trump, Musk twice made a gesture interpreted by many as a Nazi or a fascist Roman salute.[e] He thumped his right hand over his heart, fingers spread wide, and then extended his right arm out, emphatically, at an upward angle, palm down and fingers together. He then repeated the gesture to the crowd behind him. As he finished the gestures, he said to the crowd, "My heart goes out to you. It is thanks to you that the future of civilization is assured." It was widely condemned as an intentional Nazi salute in Germany, where making such gestures is illegal. The Anti-Defamation League said it was not a Nazi salute, but other Jewish organizations disagreed and condemned the salute. American public opinion was divided on partisan lines as to whether it was a fascist salute. Musk dismissed the accusations of Nazi sympathies, deriding them as "dirty tricks" and a "tired" attack. Neo-Nazi and white supremacist groups celebrated it as a Nazi salute. Multiple European political parties demanded that Musk be banned from entering their countries. The concept of DOGE emerged in a discussion between Musk and Donald Trump, and in August 2024, Trump committed to giving Musk an advisory role, with Musk accepting the offer. In November and December 2024, Musk suggested that the organization could help to cut the U.S. federal budget, consolidate the number of federal agencies, and eliminate the Consumer Financial Protection Bureau, and that its final stage would be "deleting itself". In January 2025, the organization was created by executive order, and Musk was designated a "special government employee". Musk led the organization and was a senior advisor to the president, although his official role is not clear. In sworn statement during a lawsuit, the director of the White House Office of Administration stated that Musk "is not an employee of the U.S. DOGE Service or U.S. DOGE Service Temporary Organization", "is not the U.S. DOGE Service administrator", and has "no actual or formal authority to make government decisions himself". Trump said two days later that he had put Musk in charge of DOGE. A federal judge has ruled that Musk acted as the de facto leader of DOGE. Musk's role in the second Trump administration, particularly in response to DOGE, has attracted public backlash. He was criticized for his treatment of federal government employees, including his influence over the mass layoffs of the federal workforce. He has prioritized secrecy within the organization and has accused others of violating privacy laws. A Senate report alleged that Musk could avoid up to $2 billion in legal liability as a result of DOGE's actions. In May 2025, Bill Gates accused Musk of "killing the world's poorest children" through his cuts to USAID, which modeling by Boston University estimated had resulted in 300,000 deaths by this time, most of them of children. By November 2025, the estimated death toll had increased to 400,000 children and 200,000 adults. Musk announced on May 28, 2025, that he would depart from the Trump administration as planned when the special government employee's 130 day deadline expired, with a White House official confirming that Musk's offboarding from the Trump administration was already underway. His departure was officially confirmed during a joint Oval Office press conference with Trump on May 30, 2025. @realDonaldTrump is in the Epstein files. That is the real reason they have not been made public. June 5, 2025 After leaving office, Musk criticized the Trump administration's Big Beautiful Bill, calling it a "disgusting abomination" due to its provisions increasing the deficit. A feud began between Musk and Trump, with its most notable event being Musk alleging Trump had ties to sex offender Jeffrey Epstein on X (formerly Twitter) on June 5, 2025. Trump responded on Truth Social stating that Musk went "CRAZY" after the "EV Mandate" was purportedly taken away and threatened to cut Musk's government contracts. Musk then called for a third Trump impeachment. The next day, Trump stated that he did not wish to reconcile with Musk, and added that Musk would face "very serious consequences" if he funds Democratic candidates. On June 11, Musk publicly apologized for the tweets against Trump, saying they "went too far". Views November 6, 2022 Rejecting the conservative label, Musk has described himself as a political moderate, even as his views have become more right-wing over time. His views have been characterized as libertarian and far-right, and after his involvement in European politics, they have received criticism from world leaders such as Emmanuel Macron and Olaf Scholz. Within the context of American politics, Musk supported Democratic candidates up until 2022, at which point he voted for a Republican for the first time. He has stated support for universal basic income, gun rights, freedom of speech, a tax on carbon emissions, and H-1B visas. Musk has expressed concern about issues such as artificial intelligence (AI) and climate change, and has been a critic of wealth tax, short-selling, and government subsidies. An immigrant himself, Musk has been accused of being anti-immigration, and regularly blames immigration policies for illegal immigration. He is also a pronatalist who believes population decline is the biggest threat to civilization, and identifies as a cultural Christian. Musk has long been an advocate for space colonization, especially the colonization of Mars. He has repeatedly pushed for humanity colonizing Mars, in order to become an interplanetary species and lower the risks of human extinction. Musk has promoted conspiracy theories and made controversial statements that have led to accusations of racism, sexism, antisemitism, transphobia, disseminating disinformation, and support of white pride. While describing himself as a "pro-Semite", his comments regarding George Soros and Jewish communities have been condemned by the Anti-Defamation League and the Biden White House. Musk was criticized during the COVID-19 pandemic for making unfounded epidemiological claims, defying COVID-19 lockdowns restrictions, and supporting the Canada convoy protest against vaccine mandates. He has amplified false claims of white genocide in South Africa. Musk has been critical of Israel's actions in the Gaza Strip during the Gaza war, praised China's economic and climate goals, suggested that Taiwan and China should resolve cross-strait relations, and was described as having a close relationship with the Chinese government. In Europe, Musk expressed support for Ukraine in 2022 during the Russian invasion, recommended referendums and peace deals on the annexed Russia-occupied territories, and supported the far-right Alternative for Germany political party in 2024. Regarding British politics, Musk blamed the 2024 UK riots on mass migration and open borders, criticized Prime Minister Keir Starmer for what he described as a "two-tier" policing system, and was subsequently attacked as being responsible for spreading misinformation and amplifying the far-right. He has also voiced his support for far-right activist Tommy Robinson and pledged electoral support for Reform UK. In February 2026, Musk described Spanish Prime Minister Pedro Sánchez as a "tyrant" following Sánchez's proposal to prohibit minors under the age of 16 from accessing social media platforms. Legal affairs In 2018, Musk was sued by the U.S. Securities and Exchange Commission (SEC) for a tweet stating that funding had been secured for potentially taking Tesla private.[f] The securities fraud lawsuit characterized the tweet as false, misleading, and damaging to investors, and sought to bar Musk from serving as CEO of publicly traded companies. Two days later, Musk settled with the SEC, without admitting or denying the SEC's allegations. As a result, Musk and Tesla were fined $20 million each, and Musk was forced to step down for three years as Tesla chairman but was able to remain as CEO. Shareholders filed a lawsuit over the tweet, and in February 2023, a jury found Musk and Tesla not liable. Musk has stated in interviews that he does not regret posting the tweet that triggered the SEC investigation. In 2019, Musk stated in a tweet that Tesla would build half a million cars that year. The SEC reacted by asking a court to hold him in contempt for violating the terms of the 2018 settlement agreement. A joint agreement between Musk and the SEC eventually clarified the previous agreement details, including a list of topics about which Musk needed preclearance. In 2020, a judge blocked a lawsuit that claimed a tweet by Musk regarding Tesla stock price ("too high imo") violated the agreement. Freedom of Information Act (FOIA)-released records showed that the SEC concluded Musk had subsequently violated the agreement twice by tweeting regarding "Tesla's solar roof production volumes and its stock price". In October 2023, the SEC sued Musk over his refusal to testify a third time in an investigation into whether he violated federal law by purchasing Twitter stock in 2022. In February 2024, Judge Laurel Beeler ruled that Musk must testify again. In January 2025, the SEC filed a lawsuit against Musk for securities violations related to his purchase of Twitter. In January 2024, Delaware judge Kathaleen McCormick ruled in a 2018 lawsuit that Musk's $55 billion pay package from Tesla be rescinded. McCormick called the compensation granted by the company's board "an unfathomable sum" that was unfair to shareholders. The Delaware Supreme Court overturned McCormick's decision in December 2025, restoring Musk's compensation package and awarding $1 in nominal damages. Personal life Musk became a U.S. citizen in 2002. From the early 2000s until late 2020, Musk resided in California, where both Tesla and SpaceX were founded. He then relocated to Cameron County, Texas, saying that California had become "complacent" about its economic success. While hosting Saturday Night Live in 2021, Musk stated that he has Asperger syndrome (an outdated term for autism spectrum disorder). When asked about his experience growing up with Asperger's syndrome in a TED2022 conference in Vancouver, Musk stated that "the social cues were not intuitive ... I would just tend to take things very literally ... but then that turned out to be wrong — [people were not] simply saying exactly what they mean, there's all sorts of other things that are meant, and [it] took me a while to figure that out." Musk suffers from back pain and has undergone several spine-related surgeries, including a disc replacement. In 2000, he contracted a severe case of malaria while on vacation in South Africa. Musk has stated he uses doctor-prescribed ketamine for occasional depression and that he doses "a small amount once every other week or something like that"; since January 2024, some media outlets have reported that he takes ketamine, marijuana, LSD, ecstasy, mushrooms, cocaine and other drugs. Musk at first refused to comment on his alleged drug use, before responding that he had not tested positive for drugs, and that if drugs somehow improved his productivity, "I would definitely take them!". The New York Times' investigations revealed Musk's overuse of ketamine and numerous other drugs, as well as strained family relationships and concerns from close associates who have become troubled by his public behavior as he became more involved in political activities and government work. According to The Washington Post, President Trump described Musk as "a big-time drug addict". Through his own label Emo G Records, Musk released a rap track, "RIP Harambe", on SoundCloud in March 2019. The following year, he released an EDM track, "Don't Doubt Ur Vibe", featuring his own lyrics and vocals. Musk plays video games, which he stated has a "'restoring effect' that helps his 'mental calibration'". Some games he plays include Quake, Diablo IV, Elden Ring, and Polytopia. Musk once claimed to be one of the world's top video game players but has since admitted to "account boosting", or cheating by hiring outside services to achieve top player rankings. Musk has justified the boosting by claiming that all top accounts do it so he has to as well to remain competitive. In 2024 and 2025, Musk criticized the video game Assassin's Creed Shadows and its creator Ubisoft for "woke" content. Musk posted to X that "DEI kills art" and specified the inclusion of the historical figure Yasuke in the Assassin's Creed game as offensive; he also called the game "terrible". Ubisoft responded by saying that Musk's comments were "just feeding hatred" and that they were focused on producing a game not pushing politics. Musk has fathered at least 14 children, one of whom died as an infant. The Wall Street Journal reported in 2025 that sources close to Musk suggest that the "true number of Musk's children is much higher than publicly known". He had six children with his first wife, Canadian author Justine Wilson, whom he met while attending Queen's University in Ontario, Canada; they married in 2000. In 2002, their first child Nevada Musk died of sudden infant death syndrome at the age of 10 weeks. After his death, the couple used in vitro fertilization (IVF) to continue their family; they had twins in 2004, followed by triplets in 2006. The couple divorced in 2008 and have shared custody of their children. The elder twin he had with Wilson came out as a trans woman and, in 2022, officially changed her name to Vivian Jenna Wilson, adopting her mother's surname because she no longer wished to be associated with Musk. Musk began dating English actress Talulah Riley in 2008. They married two years later at Dornoch Cathedral in Scotland. In 2012, the couple divorced, then remarried the following year. After briefly filing for divorce in 2014, Musk finalized a second divorce from Riley in 2016. Musk then dated the American actress Amber Heard for several months in 2017; he had reportedly been "pursuing" her since 2012. In 2018, Musk and Canadian musician Grimes confirmed they were dating. Grimes and Musk have three children, born in 2020, 2021, and 2022.[g] Musk and Grimes originally gave their eldest child the name "X Æ A-12", which would have violated California regulations as it contained characters that are not in the modern English alphabet; the names registered on the birth certificate are "X" as a first name, "Æ A-Xii" as a middle name, and "Musk" as a last name. They received criticism for choosing a name perceived to be impractical and difficult to pronounce; Musk has said the intended pronunciation is "X Ash A Twelve". Their second child was born via surrogacy. Despite the pregnancy, Musk confirmed reports that the couple were "semi-separated" in September 2021; in an interview with Time in December 2021, he said he was single. In October 2023, Grimes sued Musk over parental rights and custody of X Æ A-Xii. Elon Musk has taken X Æ A-Xii to multiple official events in Washington, D.C. during Trump's second term in office. Also in July 2022, The Wall Street Journal reported that Musk allegedly had an affair with Nicole Shanahan, the wife of Google co-founder Sergey Brin, in 2021, leading to their divorce the following year. Musk denied the report. Musk also had a relationship with Australian actress Natasha Bassett, who has been described as "an occasional girlfriend". In October 2024, The New York Times reported Musk bought a Texas compound for his children and their mothers, though Musk denied having done so. Musk also has four children with Shivon Zilis, director of operations and special projects at Neuralink: twins born via IVF in 2021, a child born in 2024 via surrogacy and a child born in 2025.[h] On February 14, 2025, Ashley St. Clair, an influencer and author, posted on X claiming to have given birth to Musk's son Romulus five months earlier, which media outlets reported as Musk's supposed thirteenth child.[i] On February 22, 2025, it was reported that St Clair had filed for sole custody of her five-month-old son and for Musk to be recognised as the child's father. On March 31, 2025, Musk wrote that, while he was unsure if he was the father of St. Clair's child, he had paid St. Clair $2.5 million and would continue paying her $500,000 per year.[j] Later reporting from the Wall Street Journal indicated that $1 million of these payments to St. Clair were structured as a loan. In 2014, Musk and Ghislaine Maxwell appeared together in a photograph taken at an Academy Awards after-party, which Musk later described as a "photobomb". The January 2026 Epstein files contain emails between Musk and Epstein from 2012 to 2013, after Epstein's first conviction. Emails released on January 30, 2026, indicated that Epstein invited Musk to visit his private island on multiple occasions. The correspondence showed that while Epstein repeatedly encouraged Musk to attend, Musk did not visit the island. In one instance, Musk discussed the possibility of attending a party with his then-wife Talulah Riley and asked which day would be the "wildest party"; according to the emails, the visit did not take place after Epstein later cancelled the plans.[k] On Christmas day in 2012, Musk emailed Epstein asking "Do you have any parties planned? I’ve been working to the edge of sanity this year and so, once my kids head home after Christmas, I really want to hit the party scene in St Barts or elsewhere and let loose. The invitation is much appreciated, but a peaceful island experience is the opposite of what I’m looking for". Epstein replied that the "ratio on my island" might make Musk's wife uncomfortable to which Musk responded, "Ratio is not a problem for Talulah". On September 11, 2013, Epstein sent an email asking Musk if he had any plans for coming to New York for the opening of the United Nations General Assembly where many "interesting people" would be coming to his house to which Musk responded that "Flying to NY to see UN diplomats do nothing would be an unwise use of time". Epstein responded by stating "Do you think i am retarded. Just kidding, there is no one over 25 and all very cute." Musk has denied any close relationship with Epstein and described him as a "creep" who attempted to ingratiate himself with influential people. When Musk was asked in 2019 if he introduced Epstein to Mark Zuckerberg, Musk responded: "I don’t recall introducing Epstein to anyone, as I don’t know the guy well enough to do so." The released emails nonetheless showed cordial exchanges on a range of topics, including Musk's inquiry about parties on the island. The correspondence also indicated that Musk suggested hosting Epstein at SpaceX, while Epstein separately discussed plans to tour SpaceX and bring "the girls", though there is no evidence that such a visit occurred. Musk has described the release of the files a "distraction", later accusing the second Trump administration of suppressing them to protect powerful individuals, including Trump himself.[l] Wealth Elon Musk is the wealthiest person in the world, with an estimated net worth of US$690 billion as of January 2026, according to the Bloomberg Billionaires Index, and $852 billion according to Forbes, primarily from his ownership stakes in SpaceX and Tesla. Having been first listed on the Forbes Billionaires List in 2012, around 75% of Musk's wealth was derived from Tesla stock in November 2020, although he describes himself as "cash poor". According to Forbes, he became the first person in the world to achieve a net worth of $300 billion in 2021; $400 billion in December 2024; $500 billion in October 2025; $600 billion in mid-December 2025; $700 billion later that month; and $800 billion in February 2026. In November 2025, a Tesla pay package worth potentially $1 trillion for Musk was approved, which he is to receive over 10 years if he meets specific goals. Public image Although his ventures have been highly influential within their separate industries starting in the 2000s, Musk only became a public figure in the early 2010s. He has been described as an eccentric who makes spontaneous and impactful decisions, while also often making controversial statements, contrary to other billionaires who prefer reclusiveness to protect their businesses. Musk's actions and his expressed views have made him a polarizing figure. Biographer Ashlee Vance described people's opinions of Musk as polarized due to his "part philosopher, part troll" persona on Twitter. He has drawn denouncement for using his platform to mock the self-selection of personal pronouns, while also receiving praise for bringing international attention to matters like British survivors of grooming gangs. Musk has been described as an American oligarch due to his extensive influence over public discourse, social media, industry, politics, and government policy. After Trump's re-election, Musk's influence and actions during the transition period and the second presidency of Donald Trump led some to call him "President Musk", the "actual president-elect", "shadow president" or "co-president". Awards for his contributions to the development of the Falcon rockets include the American Institute of Aeronautics and Astronautics George Low Transportation Award in 2008, the Fédération Aéronautique Internationale Gold Space Medal in 2010, and the Royal Aeronautical Society Gold Medal in 2012. In 2015, he received an honorary doctorate in engineering and technology from Yale University and an Institute of Electrical and Electronics Engineers Honorary Membership. Musk was elected a Fellow of the Royal Society (FRS) in 2018.[m] In 2022, Musk was elected to the National Academy of Engineering. Time has listed Musk as one of the most influential people in the world in 2010, 2013, 2018, and 2021. Musk was selected as Time's "Person of the Year" for 2021. Then Time editor-in-chief Edward Felsenthal wrote that, "Person of the Year is a marker of influence, and few individuals have had more influence than Musk on life on Earth, and potentially life off Earth too." Notes References Works cited Further reading External links |
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Contents Jews Jews (Hebrew: יְהוּדִים, ISO 259-2: Yehudim, Israeli pronunciation: [jehuˈdim]), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of ancient Israel and Judah. They traditionally adhere to Judaism. Jewish ethnicity, religion, and community are highly interrelated, as Judaism is an ethnic religion, though many ethnic Jews do not practice it. Religious Jews regard converts to Judaism as members of the Jewish nation, pursuant to the long-standing conversion process. The Israelites emerged from the pre-existing Canaanite peoples to establish Israel and Judah in the Southern Levant during the Iron Age. Originally, Jews referred to the inhabitants of the kingdom of Judah and were distinguished from the gentiles and the Samaritans. According to the Hebrew Bible, these inhabitants predominately originate from the tribe of Judah, who were descendants of Judah, the fourth son of Jacob. The tribe of Benjamin were another significant demographic in Judah and were considered Jews too. By the late 6th century BCE, Judaism had evolved from the Israelite religion, dubbed Yahwism (for Yahweh) by modern scholars, having a theology that religious Jews believe to be the expression of the Mosaic covenant between God and the Jewish people. After the Babylonian exile, Jews referred to followers of Judaism, descendants of the Israelites, citizens of Judea, or allies of the Judean state. Jewish migration within the Mediterranean region during the Hellenistic period, followed by population transfers, caused by events like the Jewish–Roman wars, gave rise to the Jewish diaspora, consisting of diverse Jewish communities that maintained their sense of Jewish history, identity, and culture. In the following millennia, Jewish diaspora communities coalesced into three major ethnic subdivisions according to where their ancestors settled: the Ashkenazim (Central and Eastern Europe), the Sephardim (Iberian Peninsula), and the Mizrahim (Middle East and North Africa). While these three major divisions account for most of the world's Jews, there are other smaller Jewish groups outside of the three. Prior to World War II, the global Jewish population reached a peak of 16.7 million, representing around 0.7% of the world's population at that time. During World War II, approximately six million Jews throughout Europe were systematically murdered by Nazi Germany in a genocide known as the Holocaust. Since then, the population has slowly risen again, and as of 2021[update], was estimated to be at 15.2 million by the demographer Sergio Della Pergola or less than 0.2% of the total world population in 2012.[b] Today, over 85% of Jews live in Israel or the United States. Israel, whose population is 73.9% Jewish, is the only country where Jews comprise more than 2.5% of the population. Jews have significantly influenced and contributed to the development and growth of human progress in many fields, both historically and in modern times, including in science and technology, philosophy, ethics, literature, governance, business, art, music, comedy, theatre, cinema, architecture, food, medicine, and religion. Jews founded Christianity and had an indirect but profound influence on Islam. In these ways and others, Jews have played a significant role in the development of Western culture. Name and etymology The term "Jew" is derived from the Hebrew word יְהוּדִי Yehudi, with the plural יְהוּדִים Yehudim. Endonyms in other Jewish languages include the Ladino ג׳ודיו Djudio (plural ג׳ודיוס, Djudios) and the Yiddish ייִד Yid (plural ייִדן Yidn). Though Genesis 29:35 and 49:8 connect "Judah" with the verb yada, meaning "praise", scholars generally agree that "Judah" most likely derives from the name of a Levantine geographic region dominated by gorges and ravines. The gradual ethnonymic shift from "Israelites" to "Jews", regardless of their descent from Judah, although not contained in the Torah, is made explicit in the Book of Esther (4th century BCE) of the Tanakh. Some modern scholars disagree with the conflation, based on the works of Josephus, Philo and Apostle Paul. The English word "Jew" is a derivation of Middle English Gyw, Iewe. The latter was loaned from the Old French giu, which itself evolved from the earlier juieu, which in turn derived from judieu/iudieu which through elision had dropped the letter "d" from the Medieval Latin Iudaeus, which, like the New Testament Greek term Ioudaios, meant both "Jew" and "Judean" / "of Judea". The Greek term was a loan from Aramaic *yahūdāy, corresponding to Hebrew יְהוּדִי Yehudi. Some scholars prefer translating Ioudaios as "Judean" in the Bible since it is more precise, denotes the community's origins and prevents readers from engaging in antisemitic eisegesis. Others disagree, believing that it erases the Jewish identity of Biblical characters such as Jesus. Daniel R. Schwartz distinguishes "Judean" and "Jew". Here, "Judean" refers to the inhabitants of Judea, which encompassed southern Palestine. Meanwhile, "Jew" refers to the descendants of Israelites that adhere to Judaism. Converts are included in the definition. But Shaye J.D. Cohen argues that "Judean" is inclusive of believers of the Judean God and allies of the Judean state. Another scholar, Jodi Magness, wrote the term Ioudaioi refers to a "people of Judahite/Judean ancestry who worshipped the God of Israel as their national deity and (at least nominally) lived according to his laws." The etymological equivalent is in use in other languages, e.g., يَهُودِيّ yahūdī (sg.), al-yahūd (pl.), in Arabic, "Jude" in German, "judeu" in Portuguese, "Juif" (m.)/"Juive" (f.) in French, "jøde" in Danish and Norwegian, "judío/a" in Spanish, "jood" in Dutch, "żyd" in Polish etc., but derivations of the word "Hebrew" are also in use to describe a Jew, e.g., in Italian (Ebreo), in Persian ("Ebri/Ebrani" (Persian: عبری/عبرانی)) and Russian (Еврей, Yevrey). The German word "Jude" is pronounced [ˈjuːdə], the corresponding adjective "jüdisch" [ˈjyːdɪʃ] (Jewish) is the origin of the word "Yiddish". According to The American Heritage Dictionary of the English Language, fourth edition (2000), It is widely recognized that the attributive use of the noun Jew, in phrases such as Jew lawyer or Jew ethics, is both vulgar and highly offensive. In such contexts Jewish is the only acceptable possibility. Some people, however, have become so wary of this construction that they have extended the stigma to any use of Jew as a noun, a practice that carries risks of its own. In a sentence such as There are now several Jews on the council, which is unobjectionable, the substitution of a circumlocution like Jewish people or persons of Jewish background may in itself cause offense for seeming to imply that Jew has a negative connotation when used as a noun. Identity Judaism shares some of the characteristics of a nation, an ethnicity, a religion, and a culture, making the definition of who is a Jew vary slightly depending on whether a religious or national approach to identity is used.[better source needed] Generally, in modern secular usage, Jews include three groups: people who were born to a Jewish family regardless of whether or not they follow the religion, those who have some Jewish ancestral background or lineage (sometimes including those who do not have strictly matrilineal descent), and people without any Jewish ancestral background or lineage who have formally converted to Judaism and therefore are followers of the religion. In the context of biblical and classical literature, Jews could refer to inhabitants of the Kingdom of Judah, or the broader Judean region, allies of the Judean state, or anyone that followed Judaism. Historical definitions of Jewish identity have traditionally been based on halakhic definitions of matrilineal descent, and halakhic conversions. These definitions of who is a Jew date back to the codification of the Oral Torah into the Babylonian Talmud, around 200 CE. Interpretations by Jewish sages of sections of the Tanakh – such as Deuteronomy 7:1–5, which forbade intermarriage between their Israelite ancestors and seven non-Israelite nations: "for that [i.e. giving your daughters to their sons or taking their daughters for your sons,] would turn away your children from following me, to serve other gods"[failed verification] – are used as a warning against intermarriage between Jews and gentiles. Leviticus 24:10 says that the son in a marriage between a Hebrew woman and an Egyptian man is "of the community of Israel." This is complemented by Ezra 10:2–3, where Israelites returning from Babylon vow to put aside their gentile wives and their children. A popular theory is that the rape of Jewish women in captivity brought about the law of Jewish identity being inherited through the maternal line, although scholars challenge this theory citing the Talmudic establishment of the law from the pre-exile period. Another argument is that the rabbis changed the law of patrilineal descent to matrilineal descent due to the widespread rape of Jewish women by Roman soldiers. Since the anti-religious Haskalah movement of the late 18th and 19th centuries, halakhic interpretations of Jewish identity have been challenged. According to historian Shaye J. D. Cohen, the status of the offspring of mixed marriages was determined patrilineally in the Bible. He brings two likely explanations for the change in Mishnaic times: first, the Mishnah may have been applying the same logic to mixed marriages as it had applied to other mixtures (Kil'ayim). Thus, a mixed marriage is forbidden as is the union of a horse and a donkey, and in both unions the offspring are judged matrilineally. Second, the Tannaim may have been influenced by Roman law, which dictated that when a parent could not contract a legal marriage, offspring would follow the mother. Rabbi Rivon Krygier follows a similar reasoning, arguing that Jewish descent had formerly passed through the patrilineal descent and the law of matrilineal descent had its roots in the Roman legal system. Origins The prehistory and ethnogenesis of the Jews are closely intertwined with archaeology, biology, historical textual records, mythology, and religious literature. The ethnic origin of the Jews lie in the Israelites, a confederation of Iron Age Semitic-speaking tribes that inhabited a part of Canaan during the tribal and monarchic periods. Modern Jews are named after and also descended from the southern Israelite Kingdom of Judah. Gary A. Rendsburg links the early Canaanite nomadic pastoralists confederation to the Shasu known to the Egyptians around the 15th century BCE. According to the Hebrew Bible narrative, Jewish history begins with the Biblical patriarchs such as Abraham, his son Isaac, Isaac's son Jacob, and the Biblical matriarchs Sarah, Rebecca, Leah, and Rachel, who lived in Canaan. The twelve sons of Jacob subsequently gave birth to the Twelve Tribes. Jacob and his family migrated to Ancient Egypt after being invited to live with Jacob's son Joseph by the Pharaoh himself. Jacob's descendants were later enslaved until the Exodus, led by Moses. Afterwards, the Israelites conquered Canaan under Moses' successor Joshua, and went through the period of the Biblical judges after the death of Joshua. Through the mediation of Samuel, the Israelites were subject to a king, Saul, who was succeeded by David and then Solomon, after whom the United Monarchy ended and was split into a separate Kingdom of Israel and a Kingdom of Judah. The Kingdom of Judah is described as comprising the tribes of Judah, Benjamin and partially, Levi. They later assimilated remnants of other tribes who migrated there from the northern Kingdom of Israel. In the extra-biblical record, the Israelites become visible as a people between 1200 and 1000 BCE. There is well accepted archeological evidence referring to "Israel" in the Merneptah Stele, which dates to about 1200 BCE, and in the Mesha stele from 840 BCE. It is debated whether a period like that of the Biblical judges occurred and if there ever was a United Monarchy. There is further disagreement about the earliest existence of the Kingdoms of Israel and Judah and their extent and power. Historians agree that a Kingdom of Israel existed by c. 900 BCE,: 169–95 there is a consensus that a Kingdom of Judah existed by c. 700 BCE at least, and recent excavations in Khirbet Qeiyafa have provided strong evidence for dating the Kingdom of Judah to the 10th century BCE. In 587 BCE, Nebuchadnezzar II, King of the Neo-Babylonian Empire, besieged Jerusalem, destroyed the First Temple and deported parts of the Judahite population. Scholars disagree regarding the extent to which the Bible should be accepted as a historical source for early Israelite history. Rendsburg states that there are two approximately equal groups of scholars who debate the historicity of the biblical narrative, the minimalists who largely reject it, and the maximalists who largely accept it, with the minimalists being the more vocal of the two. Some of the leading minimalists reframe the biblical account as constituting the Israelites' inspiring national myth narrative, suggesting that according to the modern archaeological and historical account, the Israelites and their culture did not overtake the region by force, but instead branched out of the Canaanite peoples and culture through the development of a distinct monolatristic—and later monotheistic—religion of Yahwism centered on Yahweh, one of the gods of the Canaanite pantheon. The growth of Yahweh-centric belief, along with a number of cultic practices, gradually gave rise to a distinct Israelite ethnic group, setting them apart from other Canaanites. According to Dever, modern archaeologists have largely discarded the search for evidence of the biblical narrative surrounding the patriarchs and the exodus. According to the maximalist position, the modern archaeological record independently points to a narrative which largely agrees with the biblical account. This narrative provides a testimony of the Israelites as a nomadic people known to the Egyptians as belonging to the Shasu. Over time these nomads left the desert and settled on the central mountain range of the land of Canaan, in simple semi-nomadic settlements in which pig bones are notably absent. This population gradually shifted from a tribal lifestyle to a monarchy. While the archaeological record of the ninth century BCE provides evidence for two monarchies, one in the south under a dynasty founded by a figure named David with its capital in Jerusalem, and one in the north under a dynasty founded by a figure named Omri with its capital in Samaria. It also points to an early monarchic period in which these regions shared material culture and religion, suggesting a common origin. Archaeological finds also provide evidence for the later cooperation of these two kingdoms in their coalition against Aram, and for their destructions by the Assyrians and later by the Babylonians. Genetic studies on Jews show that most Jews worldwide bear a common genetic heritage which originates in the Middle East, and that they share certain genetic traits with other Gentile peoples of the Fertile Crescent. The genetic composition of different Jewish groups shows that Jews share a common gene pool dating back four millennia, as a marker of their common ancestral origin. Despite their long-term separation, Jewish communities maintained their unique commonalities, propensities, and sensibilities in culture, tradition, and language. History The earliest recorded evidence of a people by the name of Israel appears in the Merneptah Stele, which dates to around 1200 BCE. The majority of scholars agree that this text refers to the Israelites, a group that inhabited the central highlands of Canaan, where archaeological evidence shows that hundreds of small settlements were constructed between the 12th and 10th centuries BCE. The Israelites differentiated themselves from neighboring peoples through various distinct characteristics including religious practices, prohibition on intermarriage, and an emphasis on genealogy and family history. In the 10th century BCE, two neighboring Israelite kingdoms—the northern Kingdom of Israel and the southern Kingdom of Judah—emerged. Since their inception, they shared ethnic, cultural, linguistic and religious characteristics despite a complicated relationship. Israel, with its capital mostly in Samaria, was larger and wealthier, and soon developed into a regional power. In contrast, Judah, with its capital in Jerusalem, was less prosperous and covered a smaller, mostly mountainous territory. However, while in Israel the royal succession was often decided by a military coup d'état, resulting in several dynasty changes, political stability in Judah was much greater, as it was ruled by the House of David for the whole four centuries of its existence. Scholars also describe Biblical Jews as a 'proto-nation', in the modern nationalist sense, comparable to classical Greeks, the Gauls and the British Celts. Around 720 BCE, Kingdom of Israel was destroyed when it was conquered by the Neo-Assyrian Empire, which came to dominate the ancient Near East. Under the Assyrian resettlement policy, a significant portion of the northern Israelite population was exiled to Mesopotamia and replaced by immigrants from the same region. During the same period, and throughout the 7th century BCE, the Kingdom of Judah, now under Assyrian vassalage, experienced a period of prosperity and witnessed a significant population growth. This prosperity continued until the Neo-Assyrian king Sennacherib devastated the region of Judah in response to a rebellion in the area, ultimately halting at Jerusalem. Later in the same century, the Assyrians were defeated by the rising Neo-Babylonian Empire, and Judah became its vassal. In 587 BCE, following a revolt in Judah, the Babylonian king Nebuchadnezzar II besieged and destroyed Jerusalem and the First Temple, putting an end to the kingdom. The majority of Jerusalem's residents, including the kingdom's elite, were exiled to Babylon. According to the Book of Ezra, the Persian Cyrus the Great ended the Babylonian exile in 538 BCE, the year after he captured Babylon. The exile ended with the return under Zerubbabel the Prince (so called because he was a descendant of the royal line of David) and Joshua the Priest (a descendant of the line of the former High Priests of the Temple) and their construction of the Second Temple circa 521–516 BCE. As part of the Persian Empire, the former Kingdom of Judah became the province of Judah (Yehud Medinata), with a smaller territory and a reduced population. Judea was under control of the Achaemenids until the fall of their empire in c. 333 BCE to Alexander the Great. After several centuries under foreign imperial rule, the Maccabean Revolt against the Seleucid Empire resulted in an independent Hasmonean kingdom, under which the Jews once again enjoyed political independence for a period spanning from 110 to 63 BCE. Under Hasmonean rule the boundaries of their kingdom were expanded to include not only the land of the historical kingdom of Judah, but also the Galilee and Transjordan. In the beginning of this process the Idumeans, who had infiltrated southern Judea after the destruction of the First Temple, were converted en masse. In 63 BCE, Judea was conquered by the Romans. From 37 BCE to 6 CE, the Romans allowed the Jews to maintain some degree of independence by installing the Herodian dynasty as vassal kings. However, Judea eventually came directly under Roman control and was incorporated into the Roman Empire as the province of Judaea. The Jewish–Roman wars, a series of failed uprisings against Roman rule during the first and second centuries CE, had profound and devastating consequences for the Jewish population of Judaea. The First Jewish–Roman War (66–73/74 CE) culminated in the destruction of Jerusalem and the Second Temple, after which the significantly diminished Jewish population was stripped of political autonomy. A few generations later, the Bar Kokhba revolt (132–136 CE) erupted in response to Roman plans to rebuild Jerusalem as a Roman colony, and, possibly, to restrictions on circumcision. Its violent suppression by the Romans led to the near-total depopulation of Judea, and the demographic and cultural center of Jewish life shifted to Galilee. Jews were subsequently banned from residing in Jerusalem and the surrounding area, and the province of Judaea was renamed Syria Palaestina. These developments effectively ended Jewish efforts to restore political sovereignty in the region for nearly two millennia. Similar upheavals impacted the Jewish communities in the empire's eastern provinces during the Diaspora Revolt (115–117 CE), leading to the near-total destruction of Jewish diaspora communities in Libya, Cyprus and Egypt, including the highly influential community in Alexandria. The destruction of the Second Temple in 70 CE brought profound changes to Judaism. With the Temple's central place in Jewish worship gone, religious practices shifted towards prayer, Torah study (including Oral Torah), and communal gatherings in synagogues. Judaism also lost much of its sectarian nature.: 69 Two of the three main sects that flourished during the late Second Temple period, namely the Sadducees and Essenes, eventually disappeared, while Pharisaic beliefs became the foundational, liturgical, and ritualistic basis of Rabbinic Judaism, which emerged as the prevailing form of Judaism since late antiquity. The Jewish diaspora existed well before the destruction of the Second Temple in 70 CE and had been ongoing for centuries, with the dispersal driven by both forced expulsions and voluntary migrations. In Mesopotamia, a testimony to the beginnings of the Jewish community can be found in Joachin's ration tablets, listing provisions allotted to the exiled Judean king and his family by Nebuchadnezzar II, and further evidence are the Al-Yahudu tablets, dated to the 6th–5th centuries BCE and related to the exiles from Judea arriving after the destruction of the First Temple, though there is ample evidence for the presence of Jews in Babylonia even from 626 BCE. In Egypt, the documents from Elephantine reveal the trials of a community founded by a Persian Jewish garrison at two fortresses on the frontier during the 5th–4th centuries BCE, and according to Josephus the Jewish community in Alexandria existed since the founding of the city in the 4th century BCE by Alexander the Great. By 200 BCE, there were well established Jewish communities both in Egypt and Mesopotamia ("Babylonia" in Jewish sources) and in the two centuries that followed, Jewish populations were also present in Asia Minor, Greece, Macedonia, Cyrene, and, beginning in the middle of the first century BCE, in the city of Rome. Later, in the first centuries CE, as a result of the Jewish-Roman Wars, a large number of Jews were taken as captives, sold into slavery, or compelled to flee from the regions affected by the wars, contributing to the formation and expansion of Jewish communities across the Roman Empire as well as in Arabia and Mesopotamia. After the Bar Kokhba revolt, the Jewish population in Judaea—now significantly reduced— made efforts to recover from the revolt's devastating effects, but never fully regained its former strength. Between the second and fourth centuries CE, the region of Galilee emerged as the primary center of Jewish life in Syria Palaestina, experiencing both demographic growth and cultural development. It was during this period that two central rabbinic texts, the Mishnah and the Jerusalem Talmud, were composed. The Romans recognized the patriarchs—rabbinic sages such as Judah ha-Nasi—as representatives of the Jewish people, granting them a certain degree of autonomy. However, as the Roman Empire gave way to the Christianized Byzantine Empire under Constantine, Jews began to face persecution by both the Church and imperial authorities, Jews came to be persecuted by the church and the authorities, and many immigrated to communities in the diaspora. By the fourth century CE, Jews are believed to have lost their demographic majority in Syria Palaestina. The long-established Jewish community of Mesopotamia, which had been living under Parthian and later Sasanian rule, beyond the confines of the Roman Empire, became an important center of Jewish study as Judea's Jewish population declined. Estimates often place the Babylonian Jewish community of the 3rd to 7th centuries at around one million, making it the largest Jewish diaspora community of that period. Under the political leadership of the exilarch, who was regarded as a royal heir of the House of David, this community had an autonomous status and served as a place of refuge for the Jews of Syria Palaestina. A number of significant Talmudic academies, such as the Nehardea, Pumbedita, and Sura academies, were established in Mesopotamia, and many important Amoraim were active there. The Babylonian Talmud, a centerpiece of Jewish religious law, was compiled in Babylonia in the 3rd to 6th centuries. Jewish diaspora communities are generally described to have coalesced into three major ethnic subdivisions according to where their ancestors settled: the Ashkenazim (initially in the Rhineland and France), the Sephardim (initially in the Iberian Peninsula), and the Mizrahim (Middle East and North Africa). Romaniote Jews, Tunisian Jews, Yemenite Jews, Egyptian Jews, Ethiopian Jews, Bukharan Jews, Mountain Jews, and other groups also predated the arrival of the Sephardic diaspora. During the same period, Jewish communities in the Middle East thrived under Islamic rule, especially in cities like Baghdad, Cairo, and Damascus. In Babylonia, from the 7th to 11th centuries the Pumbedita and Sura academies led the Arab and to an extent the entire Jewish world. The deans and students of said academies defined the Geonic period in Jewish history. Following this period were the Rishonim who lived from the 11th to 15th centuries. Like their European counterparts, Jews in the Middle East and North Africa also faced periods of persecution and discriminatory policies, with the Almohad Caliphate in North Africa and Iberia issuing forced conversion decrees, causing Jews such as Maimonides to seek safety in other regions. Despite experiencing repeated waves of persecution, Ashkenazi Jews in Western Europe worked in a variety of fields, making an impact on their communities' economy and societies. In Francia, for example, figures like Isaac Judaeus and Armentarius occupied prominent social and economic positions. Francia also witnessed the development of a sophisticated tradition of biblical commentary, as exemplified by Rashi and the tosafists. In 1144, the first documented blood libel occurred in Norwich, England, marking an escalation in the pattern of discrimination and violence that Jews had already been subjected to throughout medieval Europe. During the 12th and 13th centuries, Jews faced frequent antisemitic legislation - including laws prescribing distinctive dress - alongside segregation, repeated blood libels, pogroms, and massacres such as the Rhineland Massacres (1066). The Jews of the Holy Roman Empire were designated Servi camerae regis (“servants of the imperial chamber”) by Frederick II, a status that afforded limited protection while simultaneously entangling them in the political struggles between the emperor and the German principalities and cities. Persecution intensified during the Black Death in the mid-14th century, when Jews were accused of poisoning wells and many communities were destroyed. These pressures, combined with major expulsions such as that from England in 1290, gradually pushed Ashkenazi Jewish populations eastward into Poland, Lithuania, and Russia. One of the largest Jewish communities of the Middle Ages was in the Iberian Peninsula, which for a time contained the largest Jewish population in Europe. Iberian Jewry endured discrimination under the Visigoths but saw its fortunes improve under Umayyad rule and later the Taifa kingdoms. During this period, the Jews of Muslim Spain entered a "Golden Age" marked by achievements in Hebrew poetry and literature, religious scholarship, grammar, medicine and science, with leading figures including Hasdai ibn Shaprut, Judah Halevi, Moses ibn Ezra and Solomon ibn Gabirol. Jews also rose to high office, most notably Samuel ibn Naghrillah, a scholar and poet who served as grand vizier and military commander of Granada. The Golden Age ended with the rise of the radical Almoravid and Almohad dynasties, whose persecutions drove many Jews from Iberia (including Maimonides), together with the advancing Reconquista. In 1391, widespread pogroms swept across Spain, leaving thousands dead and forcing mass conversions. The Spanish Inquisition was later established to pursue, torture and execute conversos who continued to practice Judaism in secret, while public disputations were staged to discredit Judaism. In 1492, after the Reconquista, Isabella I of Castile and Ferdinand II of Aragon decreed the expulsion of all Jews who refused conversion, sending an estimated 200,000 into exile in Portugal, Italy, North Africa, and the Ottoman Empire. In 1497, Portugal's Jews, about 30,000, were formally ordered expelled but instead were forcibly converted to retain their economic role. In 1498, some 3,500 Jews were expelled from Navarre. Many converts outwardly adopted Christianity while secretly preserving Jewish practices, becoming crypto-Jews (also known as marranos or anusim), who remained targets of the various Inquisitions for centuries. Following the expulsions from Spain and Portugal in the 1490s, Jewish exiles dispersed across the Mediterranean, Europe, and North Africa. Many settled in the Ottoman Empire—which, replacing the Iberian Peninsula, became home to the world's largest Jewish population—where new communities developed in Anatolia, the Balkans, and the Land of Israel. Cities such as Istanbul and Thessaloniki grew into major Jewish centers, while in 16th-century Safed a flourishing spiritual life took shape. There, Solomon Alkabetz, Moses Cordovero, and Isaac Luria developed influential new schools of Kabbalah, giving powerful impetus to Jewish mysticism, and Joseph Karo composed the Shulchan Aruch, which became a cornerstone of Jewish law. In the 17th century, Portuguese conversos who returned to Judaism and engaged in trade and banking helped establish Amsterdam as a prosperous Jewish center, while also forming communities in cities such as Antwerp and London. This period also witnessed waves of messianic fervor, most notably the rise of the Sabbatean movement in the 1660s, led by Sabbatai Zvi of İzmir, which reverberated throughout the Jewish world. In Eastern Europe, Poland–Lithuania became the principal center of Ashkenazi Jewry, eventually becoming home to the largest Jewish population in the world. Jewish life flourished there from in the early modern era, supported by relative stability, economic opportunity, and strong communal institutions. The mid-17th century brought devastation with the Cossack uprisings in Ukraine, which reversed migration flows and sent refugees westward, yet Poland–Lithuania remained the demographic and cultural heartland of Ashkenazic Jewry. Following the partitions of Poland, most of its Jews came under Russian rule and were confined to the "Pale of Settlement." The 18th century also witnessed new religious and intellectual currents. Hasidism, founded by Baal Shem Tov, emphasized mysticism and piety, while its opponents, the Misnagdim ("opponents") led by the Vilna Gaon, defended rabbinic scholarship and tradition. In Western Europe, during the 1760s and 1770s, the Haskalah (Jewish Enlightenment) emerged in German-speaking lands, where figures such as Moses Mendelssohn promoted secular learning, vernacular literacy, and integration into European society. Elsewhere, Jews began to be re-admitted to Western Europe, including England, where Menasseh ben Israel petitioned Oliver Cromwell for their return. In the Americas, Jews of Sephardic descent first arrived as conversos in Spanish and Portuguese colonies, where many faced trial by Inquisition tribunals for "judaizing." A more durable presence began in Dutch Brazil, where Jews openly practiced their religion and established the first synagogues in the New World, before the Portuguese reconquest forced their dispersal to Amsterdam, the Caribbean, and North America. Sephardic communities took root in Curaçao, Suriname, Jamaica, and Barbados, later joined by Ashkenazi migrants. In North America, Jews were present from the mid-17th century, with New Amsterdam hosting the first organized congregation in 1654. By the time of the American Revolution, small communities in New York, Newport, Philadelphia, Savannah, and Charleston played an active role in the struggle for independence. In the late 19th century, Jews in Western Europe gradually achieved legal emancipation, though social acceptance remained limited by persistent antisemitism and rising nationalism. In Eastern Europe, particularly within the Russian Empire's Pale of Settlement, Jews faced mounting legal restrictions and recurring pogroms. From this environment emerged Zionism, a national revival movement originating in Central and Eastern Europe that sought to re-establish a Jewish polity in the Land of Israel as a means of returning the Jewish people to their ancestral homeland and ending centuries of exile and persecution. This led to waves of Jewish migration to Ottoman-controlled Palestine. Theodor Herzl, who is considered the father of political Zionism, offered his vision of a future Jewish state in his 1896 book Der Judenstaat (The Jewish State); a year later, he presided over the First Zionist Congress. The antisemitism that inflicted Jewish communities in Europe also triggered a mass exodus of 2.8 million Jews to the United States between 1881 and 1924. Despite this, some Jews of Europe and the United States were able to make great achievements in various fields of science and culture. Among the most influential from this period are Albert Einstein in physics, Sigmund Freud in psychology, Franz Kafka in literature, and Irving Berlin in music. Many Nobel Prize winners at this time were Jewish, as is still the case. When Adolf Hitler and the Nazi Party came to power in Germany in 1933, the situation for Jews deteriorated rapidly as a direct result of Nazi policies. Many Jews fled from Europe to Mandatory Palestine, the United States, and the Soviet Union as a result of racial anti-Semitic laws, economic difficulties, and the fear of an impending war. World War II started in 1939, and by 1941, Hitler occupied almost all of Europe. Following the German invasion of the Soviet Union in 1941, the Final Solution—an extensive, organized effort with an unprecedented scope intended to annihilate the Jewish people—began, and resulted in the persecution and murder of Jews in Europe and North Africa. In Poland, three million were murdered in gas chambers in all concentration camps combined, with one million at the Auschwitz camp complex alone. The Holocaust is the name given to this genocide, in which six million Jews in total were systematically murdered. Before and during the Holocaust, enormous numbers of Jews immigrated to Mandatory Palestine. In 1944, the Jewish insurgency in Mandatory Palestine began with the aim of gaining full independence from the United Kingdom. On 14 May 1948, upon the termination of the mandate, David Ben-Gurion declared the creation of the State of Israel, a Jewish and democratic state. Immediately afterwards, all neighboring Arab states invaded, and were resisted by the newly formed Israel Defense Forces. In 1949, the war ended and Israel started building its state and absorbing waves of Aliyah, granting citizenship to Jews all over the world via the Law of Return passed in 1950. However, both the Israeli–Palestinian conflict and wider Arab–Israeli conflict continue to this day. Culture The Jewish people and the religion of Judaism are strongly interrelated. Converts to Judaism have a status within the Jewish people equal to those born into it. However, converts who go on to practice no Judaism are likely to be viewed with skepticism. Mainstream Judaism does not proselytize, and conversion is considered a difficult task. A significant portion of conversions are undertaken by children of mixed marriages, or would-be or current spouses of Jews. The Hebrew Bible, a religious interpretation of the traditions and early history of the Jews, established the first of the Abrahamic religions, which are now practiced by 54 percent of the world. Judaism guides its adherents in both practice and belief, and has been called not only a religion, but also a "way of life," which has made drawing a clear distinction between Judaism, Jewish culture, and Jewish identity rather difficult. Throughout history, in eras and places as diverse as the ancient Hellenic world, in Europe before and after The Age of Enlightenment (see Haskalah), in Islamic Spain and Portugal, in North Africa and the Middle East, India, China, or the contemporary United States and Israel, cultural phenomena have developed that are in some sense characteristically Jewish without being at all specifically religious. Some factors in this come from within Judaism, others from the interaction of Jews or specific communities of Jews with their surroundings, and still others from the inner social and cultural dynamics of the community, as opposed to from the religion itself. This phenomenon has led to considerably different Jewish cultures unique to their own communities. Hebrew is the liturgical language of Judaism (termed lashon ha-kodesh, "the holy tongue"), the language in which most of the Hebrew scriptures (Tanakh) were composed, and the daily speech of the Jewish people for centuries. By the 5th century BCE, Aramaic, a closely related tongue, joined Hebrew as the spoken language in Judea. By the 3rd century BCE, some Jews of the diaspora were speaking Greek. Others, such as in the Jewish communities of Asoristan, known to Jews as Babylonia, were speaking Hebrew and Aramaic, the languages of the Babylonian Talmud. Dialects of these same languages were also used by the Jews of Syria Palaestina at that time.[citation needed] For centuries, Jews worldwide have spoken the local or dominant languages of the regions they migrated to, often developing distinctive dialectal forms or branches that became independent languages. Yiddish is the Judaeo-German language developed by Ashkenazi Jews who migrated to Central Europe. Ladino is the Judaeo-Spanish language developed by Sephardic Jews who migrated to the Iberian Peninsula. Due to many factors, including the impact of the Holocaust on European Jewry, the Jewish exodus from Arab and Muslim countries, and widespread emigration from other Jewish communities around the world, ancient and distinct Jewish languages of several communities, including Judaeo-Georgian, Judaeo-Arabic, Judaeo-Berber, Krymchak, Judaeo-Malayalam and many others, have largely fallen out of use. For over sixteen centuries Hebrew was used almost exclusively as a liturgical language, and as the language in which most books had been written on Judaism, with a few speaking only Hebrew on the Sabbath. Hebrew was revived as a spoken language by Eliezer ben Yehuda, who arrived in Palestine in 1881. It had not been used as a mother tongue since Tannaic times. Modern Hebrew is designated as the "State language" of Israel. Despite efforts to revive Hebrew as the national language of the Jewish people, knowledge of the language is not commonly possessed by Jews worldwide and English has emerged as the lingua franca of the Jewish diaspora. Although many Jews once had sufficient knowledge of Hebrew to study the classic literature, and Jewish languages like Yiddish and Ladino were commonly used as recently as the early 20th century, most Jews lack such knowledge today and English has by and large superseded most Jewish vernaculars. The three most commonly spoken languages among Jews today are Hebrew, English, and Russian. Some Romance languages, particularly French and Spanish, are also widely used. Yiddish has been spoken by more Jews in history than any other language, but it is far less used today following the Holocaust and the adoption of Modern Hebrew by the Zionist movement and the State of Israel. In some places, the mother language of the Jewish community differs from that of the general population or the dominant group. For example, in Quebec, the Ashkenazic majority has adopted English, while the Sephardic minority uses French as its primary language. Similarly, South African Jews adopted English rather than Afrikaans. Due to both Czarist and Soviet policies, Russian has superseded Yiddish as the language of Russian Jews, but these policies have also affected neighboring communities. Today, Russian is the first language for many Jewish communities in a number of Post-Soviet states, such as Ukraine and Uzbekistan,[better source needed] as well as for Ashkenazic Jews in Azerbaijan, Georgia, and Tajikistan. Although communities in North Africa today are small and dwindling, Jews there had shifted from a multilingual group to a monolingual one (or nearly so), speaking French in Algeria, Morocco, and the city of Tunis, while most North Africans continue to use Arabic or Berber as their mother tongue.[citation needed] There is no single governing body for the Jewish community, nor a single authority with responsibility for religious doctrine. Instead, a variety of secular and religious institutions at the local, national, and international levels lead various parts of the Jewish community on a variety of issues. Today, many countries have a Chief Rabbi who serves as a representative of that country's Jewry. Although many Hasidic Jews follow a certain hereditary Hasidic dynasty, there is no one commonly accepted leader of all Hasidic Jews. Many Jews believe that the Messiah will act a unifying leader for Jews and the entire world. A number of modern scholars of nationalism support the existence of Jewish national identity in antiquity. One of them is David Goodblatt, who generally believes in the existence of nationalism before the modern period. In his view, the Bible, the parabiblical literature and the Jewish national history provide the base for a Jewish collective identity. Although many of the ancient Jews were illiterate (as were their neighbors), their national narrative was reinforced through public readings. The Hebrew language also constructed and preserved national identity. Although it was not widely spoken after the 5th century BCE, Goodblatt states: the mere presence of the language in spoken or written form could invoke the concept of a Jewish national identity. Even if one knew no Hebrew or was illiterate, one could recognize that a group of signs was in Hebrew script. ... It was the language of the Israelite ancestors, the national literature, and the national religion. As such it was inseparable from the national identity. Indeed its mere presence in visual or aural medium could invoke that identity. Anthony D. Smith, an historical sociologist considered one of the founders of the field of nationalism studies, wrote that the Jews of the late Second Temple period provide "a closer approximation to the ideal type of the nation [...] than perhaps anywhere else in the ancient world." He adds that this observation "must make us wary of pronouncing too readily against the possibility of the nation, and even a form of religious nationalism, before the onset of modernity." Agreeing with Smith, Goodblatt suggests omitting the qualifier "religious" from Smith's definition of ancient Jewish nationalism, noting that, according to Smith, a religious component in national memories and culture is common even in the modern era. This view is echoed by political scientist Tom Garvin, who writes that "something strangely like modern nationalism is documented for many peoples in medieval times and in classical times as well," citing the ancient Jews as one of several "obvious examples", alongside the classical Greeks and the Gaulish and British Celts. Fergus Millar suggests that the sources of Jewish national identity and their early nationalist movements in the first and second centuries CE included several key elements: the Bible as both a national history and legal source, the Hebrew language as a national language, a system of law, and social institutions such as schools, synagogues, and Sabbath worship. Adrian Hastings argued that Jews are the "true proto-nation", that through the model of ancient Israel found in the Hebrew Bible, provided the world with the original concept of nationhood which later influenced Christian nations. However, following Jerusalem's destruction in the first century CE, Jews ceased to be a political entity and did not resemble a traditional nation-state for almost two millennia. Despite this, they maintained their national identity through collective memory, religion and sacred texts, even without land or political power, and remained a nation rather than just an ethnic group, eventually leading to the rise of Zionism and the establishment of Israel. Steven Weitzman suggests that Jewish nationalist sentiment in antiquity was encouraged because under foreign rule (Persians, Greeks, Romans) Jews were able to claim that they were an ancient nation. This claim was based on the preservation and reverence of their scriptures, the Hebrew language, the Temple and priesthood, and other traditions of their ancestors. Doron Mendels further observes that the Hasmonean kingdom, one of the few examples of indigenous statehood at its time, significantly reinforced Jewish national consciousness. The memory of this period of independence contributed to the persistent efforts to revive Jewish sovereignty in Judea, leading to the major revolts against Roman rule in the 1st and 2nd centuries CE. Demographics Within the world's Jewish population there are distinct ethnic divisions, most of which are primarily the result of geographic branching from an originating Israelite population, and subsequent independent evolutions. An array of Jewish communities was established by Jewish settlers in various places around the Old World, often at great distances from one another, resulting in effective and often long-term isolation. During the millennia of the Jewish diaspora the communities would develop under the influence of their local environments: political, cultural, natural, and populational. Today, manifestations of these differences among the Jews can be observed in Jewish cultural expressions of each community, including Jewish linguistic diversity, culinary preferences, liturgical practices, religious interpretations, as well as degrees and sources of genetic admixture. Jews are often identified as belonging to one of two major groups: the Ashkenazim and the Sephardim. Ashkenazim are so named in reference to their geographical origins (their ancestors' culture coalesced in the Rhineland, an area historically referred to by Jews as Ashkenaz). Similarly, Sephardim (Sefarad meaning "Spain" in Hebrew) are named in reference their origins in Iberia. The diverse groups of Jews of the Middle East and North Africa are often collectively referred to as Sephardim together with Sephardim proper for liturgical reasons having to do with their prayer rites. A common term for many of these non-Spanish Jews who are sometimes still broadly grouped as Sephardim is Mizrahim (lit. 'easterners' in Hebrew). Nevertheless, Mizrahis and Sepharadim are usually ethnically distinct. Smaller groups include, but are not restricted to, Indian Jews such as the Bene Israel, Bnei Menashe, Cochin Jews, and Bene Ephraim; the Romaniotes of Greece; the Italian Jews ("Italkim" or "Bené Roma"); the Teimanim from Yemen; various African Jews, including most numerously the Beta Israel of Ethiopia; and Chinese Jews, most notably the Kaifeng Jews, as well as various other distinct but now almost extinct communities. The divisions between all these groups are approximate and their boundaries are not always clear. The Mizrahim for example, are a heterogeneous collection of North African, Central Asian, Caucasian, and Middle Eastern Jewish communities that are no closer related to each other than they are to any of the earlier mentioned Jewish groups. In modern usage, however, the Mizrahim are sometimes termed Sephardi due to similar styles of liturgy, despite independent development from Sephardim proper. Thus, among Mizrahim there are Egyptian Jews, Iraqi Jews, Lebanese Jews, Kurdish Jews, Moroccan Jews, Libyan Jews, Syrian Jews, Bukharian Jews, Mountain Jews, Georgian Jews, Iranian Jews, Afghan Jews, and various others. The Teimanim from Yemen are sometimes included, although their style of liturgy is unique and they differ in respect to the admixture found among them to that found in Mizrahim. In addition, there is a differentiation made between Sephardi migrants who established themselves in the Middle East and North Africa after the expulsion of the Jews from Spain and Portugal in the 1490s and the pre-existing Jewish communities in those regions. Ashkenazi Jews represent the bulk of modern Jewry, with at least 70 percent of Jews worldwide (and up to 90 percent prior to World War II and the Holocaust). As a result of their emigration from Europe, Ashkenazim also represent the overwhelming majority of Jews in the New World continents, in countries such as the United States, Canada, Argentina, Australia, and Brazil. In France, the immigration of Jews from Algeria (Sephardim) has led them to outnumber the Ashkenazim. Only in Israel is the Jewish population representative of all groups, a melting pot independent of each group's proportion within the overall world Jewish population. Y DNA studies tend to imply a small number of founders in an old population whose members parted and followed different migration paths. In most Jewish populations, these male line ancestors appear to have been mainly Middle Eastern. For example, Ashkenazi Jews share more common paternal lineages with other Jewish and Middle Eastern groups than with non-Jewish populations in areas where Jews lived in Eastern Europe, Germany, and the French Rhine Valley. This is consistent with Jewish traditions in placing most Jewish paternal origins in the region of the Middle East. Conversely, the maternal lineages of Jewish populations, studied by looking at mitochondrial DNA, are generally more heterogeneous. Scholars such as Harry Ostrer and Raphael Falk believe this indicates that many Jewish males found new mates from European and other communities in the places where they migrated in the diaspora after fleeing ancient Israel. In contrast, Behar has found evidence that about 40 percent of Ashkenazi Jews originate maternally from just four female founders, who were of Middle Eastern origin. The populations of Sephardi and Mizrahi Jewish communities "showed no evidence for a narrow founder effect." Subsequent studies carried out by Feder et al. confirmed the large portion of non-local maternal origin among Ashkenazi Jews. Reflecting on their findings related to the maternal origin of Ashkenazi Jews, the authors conclude "Clearly, the differences between Jews and non-Jews are far larger than those observed among the Jewish communities. Hence, differences between the Jewish communities can be overlooked when non-Jews are included in the comparisons." However, a 2025 genetic study on the Ashkenazi Jewish founder population supports the presence of a substantial Near Eastern component in the maternal lineages. Analyses of mitochondrial DNA (mtDNA) indicate that the core founder lineages, estimated at around 54, likely originated from the Near East, with these founder signatures appearing in multiple copies across the population. While later admixture introduced additional mtDNA lineages, these absorbed lineages are distinguishable from the original founders. The findings are consistent with genome-wide Identity-by-Descent and Lineage Extinction analyses, reinforcing the Near Eastern origin of the Ashkenazi maternal founders. A study showed that 7% of Ashkenazi Jews have the haplogroup G2c, which is mainly found in Pashtuns and on lower scales all major Jewish groups, Palestinians, Syrians, and Lebanese. Studies of autosomal DNA, which look at the entire DNA mixture, have become increasingly important as the technology develops. They show that Jewish populations have tended to form relatively closely related groups in independent communities, with most in a community sharing significant ancestry in common. For Jewish populations of the diaspora, the genetic composition of Ashkenazi, Sephardic, and Mizrahi Jewish populations show a predominant amount of shared Middle Eastern ancestry. According to Behar, the most parsimonious explanation for this shared Middle Eastern ancestry is that it is "consistent with the historical formulation of the Jewish people as descending from ancient Hebrew and Israelite residents of the Levant" and "the dispersion of the people of ancient Israel throughout the Old World". North African, Italian and others of Iberian origin show variable frequencies of admixture with non-Jewish historical host populations among the maternal lines. In the case of Ashkenazi and Sephardi Jews (in particular Moroccan Jews), who are closely related, the source of non-Jewish admixture is mainly Southern European, while Mizrahi Jews show evidence of admixture with other Middle Eastern populations. Behar et al. have remarked on a close relationship between Ashkenazi Jews and modern Italians. A 2001 study found that Jews were more closely related to groups of the Fertile Crescent (Kurds, Turks, and Armenians) than to their Arab neighbors, whose genetic signature was found in geographic patterns reflective of Islamic conquests. The studies also show that Sephardic Bnei Anusim (descendants of the "anusim" who were forced to convert to Catholicism), which comprise up to 19.8 percent of the population of today's Iberia (Spain and Portugal) and at least 10 percent of the population of Ibero-America (Hispanic America and Brazil), have Sephardic Jewish ancestry within the last few centuries. The Bene Israel and Cochin Jews of India, Beta Israel of Ethiopia, and a portion of the Lemba people of Southern Africa, despite more closely resembling the local populations of their native countries, have also been thought to have some more remote ancient Jewish ancestry. Views on the Lemba have changed and genetic Y-DNA analyses in the 2000s have established a partially Middle-Eastern origin for a portion of the male Lemba population but have been unable to narrow this down further. Although historically, Jews have been found all over the world, in the decades since World War II and the establishment of Israel, they have increasingly concentrated in a small number of countries. In 2021, Israel and the United States together accounted for over 85 percent of the global Jewish population, with approximately 45.3% and 39.6% of the world's Jews, respectively. More than half (51.2%) of world Jewry resides in just ten metropolitan areas. As of 2021, these ten areas were Tel Aviv, New York, Jerusalem, Haifa, Los Angeles, Miami, Philadelphia, Paris, Washington, and Chicago. The Tel Aviv metro area has the highest percent of Jews among the total population (94.8%), followed by Jerusalem (72.3%), Haifa (73.1%), and Beersheba (60.4%), the balance mostly being Israeli Arabs. Outside Israel, the highest percent of Jews in a metropolitan area was in New York (10.8%), followed by Miami (8.7%), Philadelphia (6.8%), San Francisco (5.1%), Washington (4.7%), Los Angeles (4.7%), Toronto (4.5%), and Baltimore (4.1%). As of 2010, there were nearly 14 million Jews around the world, roughly 0.2% of the world's population at the time. According to the 2007 estimates of The Jewish People Policy Planning Institute, the world's Jewish population is 13.2 million. This statistic incorporates both practicing Jews affiliated with synagogues and the Jewish community, and approximately 4.5 million unaffiliated and secular Jews.[citation needed] According to Sergio Della Pergola, a demographer of the Jewish population, in 2021 there were about 6.8 million Jews in Israel, 6 million in the United States, and 2.3 million in the rest of the world. Israel, the Jewish nation-state, is the only country in which Jews make up a majority of the citizens. Israel was established as an independent democratic and Jewish state on 14 May 1948. Of the 120 members in its parliament, the Knesset, as of 2016[update], 14 members of the Knesset are Arab citizens of Israel (not including the Druze), most representing Arab political parties. One of Israel's Supreme Court judges is also an Arab citizen of Israel. Between 1948 and 1958, the Jewish population rose from 800,000 to two million. Currently, Jews account for 75.4 percent of the Israeli population, or 6 million people. The early years of the State of Israel were marked by the mass immigration of Holocaust survivors in the aftermath of the Holocaust and Jews fleeing Arab lands. Israel also has a large population of Ethiopian Jews, many of whom were airlifted to Israel in the late 1980s and early 1990s. Between 1974 and 1979 nearly 227,258 immigrants arrived in Israel, about half being from the Soviet Union. This period also saw an increase in immigration to Israel from Western Europe, Latin America, and North America. A trickle of immigrants from other communities has also arrived, including Indian Jews and others, as well as some descendants of Ashkenazi Holocaust survivors who had settled in countries such as the United States, Argentina, Australia, Chile, and South Africa. Some Jews have emigrated from Israel elsewhere, because of economic problems or disillusionment with political conditions and the continuing Arab–Israeli conflict. Jewish Israeli emigrants are known as yordim. The waves of immigration to the United States and elsewhere at the turn of the 19th century, the founding of Zionism and later events, including pogroms in Imperial Russia (mostly within the Pale of Settlement in present-day Ukraine, Moldova, Belarus and eastern Poland), the massacre of European Jewry during the Holocaust, and the founding of the state of Israel, with the subsequent Jewish exodus from Arab lands, all resulted in substantial shifts in the population centers of world Jewry by the end of the 20th century. More than half of the Jews live in the Diaspora (see Population table). Currently, the largest Jewish community outside Israel, and either the largest or second-largest Jewish community in the world, is located in the United States, with 6 million to 7.5 million Jews by various estimates. Elsewhere in the Americas, there are also large Jewish populations in Canada (315,000), Argentina (180,000–300,000), and Brazil (196,000–600,000), and smaller populations in Mexico, Uruguay, Venezuela, Chile, Colombia and several other countries (see History of the Jews in Latin America). According to a 2010 Pew Research Center study, about 470,000 people of Jewish heritage live in Latin America and the Caribbean. Demographers disagree on whether the United States has a larger Jewish population than Israel, with many maintaining that Israel surpassed the United States in Jewish population during the 2000s, while others maintain that the United States still has the largest Jewish population in the world. Currently, a major national Jewish population survey is planned to ascertain whether or not Israel has overtaken the United States in Jewish population. Western Europe's largest Jewish community, and the third-largest Jewish community in the world, can be found in France, home to between 483,000 and 500,000 Jews, the majority of whom are immigrants or refugees from North African countries such as Algeria, Morocco, and Tunisia (or their descendants). The United Kingdom has a Jewish community of 292,000. In Eastern Europe, the exact figures are difficult to establish. The number of Jews in Russia varies widely according to whether a source uses census data (which requires a person to choose a single nationality among choices that include "Russian" and "Jewish") or eligibility for immigration to Israel (which requires that a person have one or more Jewish grandparents). According to the latter criteria, the heads of the Russian Jewish community assert that up to 1.5 million Russians are eligible for aliyah. In Germany, the 102,000 Jews registered with the Jewish community are a slowly declining population, despite the immigration of tens of thousands of Jews from the former Soviet Union since the fall of the Berlin Wall. Thousands of Israelis also live in Germany, either permanently or temporarily, for economic reasons. Prior to 1948, approximately 800,000 Jews were living in lands which now make up the Arab world (excluding Israel). Of these, just under two-thirds lived in the French-controlled Maghreb region, 15 to 20 percent in the Kingdom of Iraq, approximately 10 percent in the Kingdom of Egypt and approximately 7 percent in the Kingdom of Yemen. A further 200,000 lived in Pahlavi Iran and the Republic of Turkey. Today, around 26,000 Jews live in Muslim-majority countries, mainly in Turkey (14,200) and Iran (9,100), while Morocco (2,000), Tunisia (1,000), and the United Arab Emirates (500) host the largest communities in the Arab world. A small-scale exodus had begun in many countries in the early decades of the 20th century, although the only substantial aliyah came from Yemen and Syria. The exodus from Arab and Muslim countries took place primarily from 1948. The first large-scale exoduses took place in the late 1940s and early 1950s, primarily in Iraq, Yemen and Libya, with up to 90 percent of these communities leaving within a few years. The peak of the exodus from Egypt occurred in 1956. The exodus in the Maghreb countries peaked in the 1960s. Lebanon was the only Arab country to see a temporary increase in its Jewish population during this period, due to an influx of refugees from other Arab countries, although by the mid-1970s the Jewish community of Lebanon had also dwindled. In the aftermath of the exodus wave from Arab states, an additional migration of Iranian Jews peaked in the 1980s when around 80 percent of Iranian Jews left the country.[citation needed] Outside Europe, the Americas, the Middle East, and the rest of Asia, there are significant Jewish populations in Australia (112,500) and South Africa (70,000). There is also a 6,800-strong community in New Zealand. Since at least the time of the Ancient Greeks, a proportion of Jews have assimilated into the wider non-Jewish society around them, by either choice or force, ceasing to practice Judaism and losing their Jewish identity. Assimilation took place in all areas, and during all time periods, with some Jewish communities, for example the Kaifeng Jews of China, disappearing entirely. The advent of the Jewish Enlightenment of the 18th century (see Haskalah) and the subsequent emancipation of the Jewish populations of Europe and America in the 19th century, accelerated the situation, encouraging Jews to increasingly participate in, and become part of, secular society. The result has been a growing trend of assimilation, as Jews marry non-Jewish spouses and stop participating in the Jewish community. Rates of interreligious marriage vary widely: In the United States, it is just under 50 percent; in the United Kingdom, around 53 percent; in France, around 30 percent; and in Australia and Mexico, as low as 10 percent. In the United States, only about a third of children from intermarriages affiliate with Jewish religious practice. The result is that most countries in the Diaspora have steady or slightly declining religiously Jewish populations as Jews continue to assimilate into the countries in which they live.[citation needed] The Jewish people and Judaism have experienced various persecutions throughout their history. During Late Antiquity and the Early Middle Ages, the Roman Empire (in its later phases known as the Byzantine Empire) repeatedly repressed the Jewish population, first by ejecting them from their homelands during the pagan Roman era and later by officially establishing them as second-class citizens during the Christian Roman era. According to James Carroll, "Jews accounted for 10% of the total population of the Roman Empire. By that ratio, if other factors had not intervened, there would be 200 million Jews in the world today, instead of something like 13 million." Later in medieval Western Europe, further persecutions of Jews by Christians occurred, notably during the Crusades—when Jews all over Germany were massacred—and in a series of expulsions from the Kingdom of England, Germany, and France. Then there occurred the largest expulsion of all, when Spain and Portugal, after the Reconquista (the Catholic Reconquest of the Iberian Peninsula), expelled both unbaptized Sephardic Jews and the ruling Muslim Moors. In the Papal States, which existed until 1870, Jews were required to live only in specified neighborhoods called ghettos. Islam and Judaism have a complex relationship. Traditionally Jews and Christians living in Muslim lands, known as dhimmis, were allowed to practice their religions and administer their internal affairs, but they were subject to certain conditions. They had to pay the jizya (a per capita tax imposed on free adult non-Muslim males) to the Islamic state. Dhimmis had an inferior status under Islamic rule. They had several social and legal disabilities such as prohibitions against bearing arms or giving testimony in courts in cases involving Muslims. Many of the disabilities were highly symbolic. The one described by Bernard Lewis as "most degrading" was the requirement of distinctive clothing, not found in the Quran or hadith but invented in early medieval Baghdad; its enforcement was highly erratic. On the other hand, Jews rarely faced martyrdom or exile, or forced compulsion to change their religion, and they were mostly free in their choice of residence and profession. Notable exceptions include the massacre of Jews and forcible conversion of some Jews by the rulers of the Almohad dynasty in Al-Andalus in the 12th century, as well as in Islamic Persia, and the forced confinement of Moroccan Jews to walled quarters known as mellahs beginning from the 15th century and especially in the early 19th century. In modern times, it has become commonplace for standard antisemitic themes to be conflated with anti-Zionist publications and pronouncements of Islamic movements such as Hezbollah and Hamas, in the pronouncements of various agencies of the Islamic Republic of Iran, and even in the newspapers and other publications of Turkish Refah Partisi."[better source needed] Throughout history, many rulers, empires and nations have oppressed their Jewish populations or sought to eliminate them entirely. Methods employed ranged from expulsion to outright genocide; within nations, often the threat of these extreme methods was sufficient to silence dissent. The history of antisemitism includes the First Crusade which resulted in the massacre of Jews; the Spanish Inquisition (led by Tomás de Torquemada) and the Portuguese Inquisition, with their persecution and autos-da-fé against the New Christians and Marrano Jews; the Bohdan Chmielnicki Cossack massacres in Ukraine; the Pogroms backed by the Russian Tsars; as well as expulsions from Spain, Portugal, England, France, Germany, and other countries in which the Jews had settled. According to a 2008 study published in the American Journal of Human Genetics, 19.8 percent of the modern Iberian population has Sephardic Jewish ancestry, indicating that the number of conversos may have been much higher than originally thought. The persecution reached a peak in Nazi Germany's Final Solution, which led to the Holocaust and the slaughter of approximately 6 million Jews. Of the world's 16 million Jews in 1939, almost 40% were murdered in the Holocaust. The Holocaust—the state-led systematic persecution and genocide of European Jews (and certain communities of North African Jews in European controlled North Africa) and other minority groups of Europe during World War II by Germany and its collaborators—remains the most notable modern-day persecution of Jews. The persecution and genocide were accomplished in stages. Legislation to remove the Jews from civil society was enacted years before the outbreak of World War II. Concentration camps were established in which inmates were used as slave labour until they died of exhaustion or disease. Where the Third Reich conquered new territory in Eastern Europe, specialized units called Einsatzgruppen murdered Jews and political opponents in mass shootings. Jews and Roma were crammed into ghettos before being transported hundreds of kilometres by freight train to extermination camps where, if they survived the journey, the majority of them were murdered in gas chambers. Virtually every arm of Germany's bureaucracy was involved in the logistics of the mass murder, turning the country into what one Holocaust scholar has called "a genocidal nation." Throughout Jewish history, Jews have repeatedly been directly or indirectly expelled from both their original homeland, the Land of Israel, and many of the areas in which they have settled. This experience as refugees has shaped Jewish identity and religious practice in many ways, and is thus a major element of Jewish history. In summary, the pogroms in Eastern Europe, the rise of modern antisemitism, the Holocaust, as well as the rise of Arab nationalism, all served to fuel the movements and migrations of huge segments of Jewry from land to land and continent to continent until they arrived back in large numbers at their original historical homeland in Israel. In the Bible, the patriarch Abraham is described as a migrant to the land of Canaan from Ur of the Chaldees. His descendants, the Children of Israel, undertook the Exodus (meaning "departure" or "exit" in Greek) from ancient Egypt, as described in the Book of Exodus. The first movement documented in the historical record occurred with the resettlement policy of the Neo-Assyrian Empire, which mandated the deportation of conquered peoples, and it is estimated some 4,500,000 among its captive populations suffered this dislocation over three centuries of Assyrian rule. With regard to Israel, Tiglath-Pileser III claims he deported 80% of the population of Lower Galilee, some 13,520 people. Some 27,000 Israelites, 20 to 25% of the population of the Kingdom of Israel, were described as being deported by Sargon II, and were replaced by other deported populations and sent into permanent exile by Assyria, initially to the Upper Mesopotamian provinces of the Assyrian Empire. Between 10,000 and 80,000 people from the Kingdom of Judah were similarly exiled by Babylonia, but these people were then returned to Judea by Cyrus the Great of the Persian Achaemenid Empire. Many Jews were exiled again by the Roman Empire. The 2,000 year dispersion of the Jewish diaspora beginning under the Roman Empire, as Jews were spread throughout the Roman world and, driven from land to land, settled wherever they could live freely enough to practice their religion. Over the course of the diaspora the center of Jewish life moved from Babylonia to the Iberian Peninsula to Poland to the United States and, as a result of Zionism, back to Israel. There were also many expulsions of Jews during the Middle Ages and Enlightenment in Europe, including: 1290, 16,000 Jews were expelled from England, (see the Statute of Jewry); in 1396, 100,000 from France; in 1421, thousands were expelled from Austria. Many of these Jews settled in East-Central Europe, especially Poland. Following the Spanish Inquisition in 1492, the Spanish population of around 200,000 Sephardic Jews were expelled by the Spanish crown and Catholic church, followed by expulsions in 1493 in Sicily (37,000 Jews) and Portugal in 1496. The expelled Jews fled mainly to the Ottoman Empire, the Netherlands, and North Africa, others migrating to Southern Europe and the Middle East. During the 19th century, France's policies of equal citizenship regardless of religion led to the immigration of Jews (especially from Eastern and Central Europe). This contributed to the arrival of millions of Jews in the New World. Over two million Eastern European Jews arrived in the United States from 1880 to 1925. In the latest phase of migrations, the Islamic Revolution of Iran caused many Iranian Jews to flee Iran. Most found refuge in the US (particularly Los Angeles, California, and Long Island, New York) and Israel. Smaller communities of Persian Jews exist in Canada and Western Europe. Similarly, when the Soviet Union collapsed, many of the Jews in the affected territory (who had been refuseniks) were suddenly allowed to leave. This produced a wave of migration to Israel in the early 1990s. Israel is the only country with a Jewish population that is consistently growing through natural population growth, although the Jewish populations of other countries, in Europe and North America, have recently increased through immigration. In the Diaspora, in almost every country the Jewish population in general is either declining or steady, but Orthodox and Haredi Jewish communities, whose members often shun birth control for religious reasons, have experienced rapid population growth. Orthodox and Conservative Judaism discourage proselytism to non-Jews, but many Jewish groups have tried to reach out to the assimilated Jewish communities of the Diaspora in order for them to reconnect to their Jewish roots. Additionally, while in principle Reform Judaism favours seeking new members for the faith, this position has not translated into active proselytism, instead taking the form of an effort to reach out to non-Jewish spouses of intermarried couples. There is also a trend of Orthodox movements reaching out to secular Jews in order to give them a stronger Jewish identity so there is less chance of intermarriage. As a result of the efforts by these and other Jewish groups over the past 25 years, there has been a trend (known as the Baal teshuva movement) for secular Jews to become more religiously observant, though the demographic implications of the trend are unknown. Additionally, there is also a growing rate of conversion to Jews by Choice of gentiles who make the decision to head in the direction of becoming Jews. Contributions Jewish individuals have played a significant role in the development and growth of Western culture, advancing many fields of thought, science and technology, both historically and in modern times, including through discrete trends in Jewish philosophy, Jewish ethics and Jewish literature, as well as specific trends in Jewish culture, including in Jewish art, Jewish music, Jewish humor, Jewish theatre, Jewish cuisine and Jewish medicine. Jews have established various Jewish political movements, religious movements, and, through the authorship of the Hebrew Bible and parts of the New Testament, provided the foundation for Christianity and Islam. More than 20 percent of the awarded Nobel Prize have gone to individuals of Jewish descent. Philanthropic giving is a widespread core function among Jewish organizations. Notes References External links |
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Contents Meta Platforms Meta Platforms, Inc. (doing business as Meta) is an American multinational technology company headquartered in Menlo Park, California. Meta owns and operates several prominent social media platforms and communication services, including Facebook, Instagram, WhatsApp, Messenger, Threads and Manus. The company also operates an advertising network for its own sites and third parties; as of 2023[update], advertising accounted for 97.8 percent of its total revenue. Meta has been described as a part of Big Tech, which refers to the largest six tech companies in the United States, Alphabet (Google), Amazon, Apple, Meta (Facebook), Microsoft, and Nvidia, which are also the largest companies in the world by market capitalization. The company was originally established in 2004 as TheFacebook, Inc., and was renamed Facebook, Inc. in 2005. In 2021, it rebranded as Meta Platforms, Inc. to reflect a strategic shift toward developing the metaverse—an interconnected digital ecosystem spanning virtual and augmented reality technologies. In 2023, Meta was ranked 31st on the Forbes Global 2000 list of the world's largest public companies. As of 2022, it was the world's third-largest spender on research and development, with R&D expenses totaling US$35.3 billion. History Facebook filed for an initial public offering (IPO) on January 1, 2012. The preliminary prospectus stated that the company sought to raise $5 billion, had 845 million monthly active users, and a website accruing 2.7 billion likes and comments daily. After the IPO, Zuckerberg would retain 22% of the total shares and 57% of the total voting power in Facebook. Underwriters valued the shares at $38 each, valuing the company at $104 billion, the largest valuation yet for a newly public company. On May 16, one day before the IPO, Facebook announced it would sell 25% more shares than originally planned due to high demand. The IPO raised $16 billion, making it the third-largest in US history (slightly ahead of AT&T Mobility and behind only General Motors and Visa). The stock price left the company with a higher market capitalization than all but a few U.S. corporations—surpassing heavyweights such as Amazon, McDonald's, Disney, and Kraft Foods—and made Zuckerberg's stock worth $19 billion. The New York Times stated that the offering overcame questions about Facebook's difficulties in attracting advertisers to transform the company into a "must-own stock". Jimmy Lee of JPMorgan Chase described it as "the next great blue-chip". Writers at TechCrunch, on the other hand, expressed skepticism, stating, "That's a big multiple to live up to, and Facebook will likely need to add bold new revenue streams to justify the mammoth valuation." Trading in the stock, which began on May 18, was delayed that day due to technical problems with the Nasdaq exchange. The stock struggled to stay above the IPO price for most of the day, forcing underwriters to buy back shares to support the price. At the closing bell, shares were valued at $38.23, only $0.23 above the IPO price and down $3.82 from the opening bell value. The opening was widely described by the financial press as a disappointment. The stock set a new record for trading volume of an IPO. On May 25, 2012, the stock ended its first full week of trading at $31.91, a 16.5% decline. On May 22, 2012, regulators from Wall Street's Financial Industry Regulatory Authority announced that they had begun to investigate whether banks underwriting Facebook had improperly shared information only with select clients rather than the general public. Massachusetts Secretary of State William F. Galvin subpoenaed Morgan Stanley over the same issue. The allegations sparked "fury" among some investors and led to the immediate filing of several lawsuits, one of them a class action suit claiming more than $2.5 billion in losses due to the IPO. Bloomberg estimated that retail investors may have lost approximately $630 million on Facebook stock since its debut. S&P Global Ratings added Facebook to its S&P 500 index on December 21, 2013. On May 2, 2014, Zuckerberg announced that the company would be changing its internal motto from "Move fast and break things" to "Move fast with stable infrastructure". The earlier motto had been described as Zuckerberg's "prime directive to his developers and team" in a 2009 interview in Business Insider, in which he also said, "Unless you are breaking stuff, you are not moving fast enough." In November 2016, Facebook announced the Microsoft Windows client of gaming service Facebook Gameroom, formerly Facebook Games Arcade, at the Unity Technologies developers conference. The client allows Facebook users to play "native" games in addition to its web games. The service was closed in June 2021. Lasso was a short-video sharing app from Facebook similar to TikTok that was launched on iOS and Android in 2018 and was aimed at teenagers. On July 2, 2020, Facebook announced that Lasso would be shutting down on July 10. In 2018, the Oculus lead Jason Rubin sent his 50-page vision document titled "The Metaverse" to Facebook's leadership. In the document, Rubin acknowledged that Facebook's virtual reality business had not caught on as expected, despite the hundreds of millions of dollars spent on content for early adopters. He also urged the company to execute fast and invest heavily in the vision, to shut out HTC, Apple, Google and other competitors in the VR space. Regarding other players' participation in the metaverse vision, he called for the company to build the "metaverse" to prevent their competitors from "being in the VR business in a meaningful way at all". In May 2019, Facebook founded Libra Networks, reportedly to develop their own stablecoin cryptocurrency. Later, it was reported that Libra was being supported by financial companies such as Visa, Mastercard, PayPal and Uber. The consortium of companies was expected to pool in $10 million each to fund the launch of the cryptocurrency coin named Libra. Depending on when it would receive approval from the Swiss Financial Market Supervisory authority to operate as a payments service, the Libra Association had planned to launch a limited format cryptocurrency in 2021. Libra was renamed Diem, before being shut down and sold in January 2022 after backlash from Swiss government regulators and the public. During the COVID-19 pandemic, the use of online services, including Facebook, grew globally. Zuckerberg predicted this would be a "permanent acceleration" that would continue after the pandemic. Facebook hired aggressively, growing from 48,268 employees in March 2020 to more than 87,000 by September 2022. Following a period of intense scrutiny and damaging whistleblower leaks, news started to emerge on October 21, 2021 about Facebook's plan to rebrand the company and change its name. In the Q3 2021 earnings call on October 25, Mark Zuckerberg discussed the ongoing criticism of the company's social services and the way it operates, and pointed to the pivoting efforts to building the metaverse – without mentioning the rebranding and the name change. The metaverse vision and the name change from Facebook, Inc. to Meta Platforms was introduced at Facebook Connect on October 28, 2021. Based on Facebook's PR campaign, the name change reflects the company's shifting long term focus of building the metaverse, a digital extension of the physical world by social media, virtual reality and augmented reality features. "Meta" had been registered as a trademark in the United States in 2018 (after an initial filing in 2015) for marketing, advertising, and computer services, by a Canadian company that provided big data analysis of scientific literature. This company was acquired in 2017 by the Chan Zuckerberg Initiative (CZI), a foundation established by Zuckerberg and his wife, Priscilla Chan, and became one of their projects. Following the rebranding announcement, CZI announced that it had already decided to deprioritize the earlier Meta project, thus it would be transferring its rights to the name to Meta Platforms, and the previous project would end in 2022. Soon after the rebranding, in early February 2022, Meta reported a greater-than-expected decline in profits in the fourth quarter of 2021. It reported no growth in monthly users, and indicated it expected revenue growth to stall. It also expected measures taken by Apple Inc. to protect user privacy to cost it some $10 billion in advertisement revenue, an amount equal to roughly 8% of its revenue for 2021. In meeting with Meta staff the day after earnings were reported, Zuckerberg blamed competition for user attention, particularly from video-based apps such as TikTok. The 27% reduction in the company's share price which occurred in reaction to the news eliminated some $230 billion of value from Meta's market capitalization. Bloomberg described the decline as "an epic rout that, in its sheer scale, is unlike anything Wall Street or Silicon Valley has ever seen". Zuckerberg's net worth fell by as much as $31 billion. Zuckerberg owns 13% of Meta, and the holding makes up the bulk of his wealth. According to published reports by Bloomberg on March 30, 2022, Meta turned over data such as phone numbers, physical addresses, and IP addresses to hackers posing as law enforcement officials using forged documents. The law enforcement requests sometimes included forged signatures of real or fictional officials. When asked about the allegations, a Meta representative said, "We review every data request for legal sufficiency and use advanced systems and processes to validate law enforcement requests and detect abuse." In June 2022, Sheryl Sandberg, the chief operating officer of 14 years, announced she would step down that year. Zuckerberg said that Javier Olivan would replace Sandberg, though in a “more traditional” role. In March 2022, Meta (except Meta-owned WhatsApp) and Instagram were banned in Russia and added to the Russian list of terrorist and extremist organizations for alleged Russophobia and hate speech (up to genocidal calls) amid the ongoing Russian invasion of Ukraine. Meta appealed against the ban, but it was upheld by a Moscow court in June of the same year. Also in March 2022, Meta and Italian eyewear giant Luxottica released Ray-Ban Stories, a series of smartglasses which could play music and take pictures. Meta and Luxottica parent company EssilorLuxottica declined to disclose sales on the line of products as of September 2022, though Meta has expressed satisfaction with its customer feedback. In July 2022, Meta saw its first year-on-year revenue decline when its total revenue slipped by 1% to $28.8bn. Analysts and journalists accredited the loss to its advertising business, which has been limited by Apple's app tracking transparency feature and the number of people who have opted not to be tracked by Meta apps. Zuckerberg also accredited the decline to increasing competition from TikTok. On October 27, 2022, Meta's market value dropped to $268 billion, a loss of around $700 billion compared to 2021, and its shares fell by 24%. It lost its spot among the top 20 US companies by market cap, despite reaching the top 5 in the previous year. In November 2022, Meta laid off 11,000 employees, 13% of its workforce. Zuckerberg said the decision to aggressively increase Meta's investments had been a mistake, as he had wrongly predicted that the surge in e-commerce would last beyond the COVID-19 pandemic. He also attributed the decline to increased competition, a global economic downturn and "ads signal loss". Plans to lay off a further 10,000 employees began in April 2023. The layoffs were part of a general downturn in the technology industry, alongside layoffs by companies including Google, Amazon, Tesla, Snap, Twitter and Lyft. Starting from 2022, Meta scrambled to catch up to other tech companies in adopting specialized artificial intelligence hardware and software. It had been using less expensive CPUs instead of GPUs for AI work, but that approach turned out to be less efficient. The company gifted the Inter-university Consortium for Political and Social Research $1.3 million to finance the Social Media Archive's aim to make their data available to social science research. In 2023, Ireland's Data Protection Commissioner imposed a record EUR 1.2 billion fine on Meta for transferring data from Europe to the United States without adequate protections for EU citizens.: 250 In March 2023, Meta announced a new round of layoffs that would cut 10,000 employees and close 5,000 open positions to make the company more efficient. Meta revenue surpassed analyst expectations for the first quarter of 2023 after announcing that it was increasing its focus on AI. On July 6, Meta launched a new app, Threads, a competitor to Twitter. Meta announced its artificial intelligence model Llama 2 in July 2023, available for commercial use via partnerships with major cloud providers like Microsoft. It was the first project to be unveiled out of Meta's generative AI group after it was set up in February. It would not charge access or usage but instead operate with an open-source model to allow Meta to ascertain what improvements need to be made. Prior to this announcement, Meta said it had no plans to release Llama 2 for commercial use. An earlier version of Llama was released to academics. In August 2023, Meta announced its permanent removal of news content from Facebook and Instagram in Canada due to the Online News Act, which requires Canadian news outlets to be compensated for content shared on its platform. The Online News Act was in effect by year-end, but Meta will not participate in the regulatory process. In October 2023, Zuckerberg said that AI would be Meta's biggest investment area in 2024. Meta finished 2023 as one of the best-performing technology stocks of the year, with its share price up 150 percent. Its stock reached an all-time high in January 2024, bringing Meta within 2% of achieving $1 trillion market capitalization. In November 2023 Meta Platforms launched an ad-free service in Europe, allowing subscribers to opt-out of personal data being collected for targeted advertising. A group of 28 European organizations, including Max Schrems' advocacy group NOYB, the Irish Council for Civil Liberties, Wikimedia Europe, and the Electronic Privacy Information Center, signed a 2024 letter to the European Data Protection Board (EDPB) expressing concern that this subscriber model would undermine privacy protections, specifically GDPR data protection standards. Meta removed the Facebook and Instagram accounts of Iran's Supreme Leader Ali Khamenei in February 2024, citing repeated violations of its Dangerous Organizations & Individuals policy. As of March, Meta was under investigation by the FDA for alleged use of their social media platforms to sell illegal drugs. On 16 May 2024, the European Commission began an investigation into Meta over concerns related to child safety. In May 2023, Iraqi social media influencer Esaa Ahmed-Adnan encountered a troubling issue when Instagram removed his posts, citing false copyright violations despite his content being original and free from copyrighted material. He discovered that extortionists were behind these takedowns, offering to restore his content for $3,000 or provide ongoing protection for $1,000 per month. This scam, exploiting Meta’s rights management tools, became widespread in the Middle East, revealing a gap in Meta’s enforcement in developing regions. An Iraqi nonprofit Tech4Peace’s founder, Aws al-Saadi helped Ahmed-Adnan and others, but the restoration process was slow, leading to significant financial losses for many victims, including prominent figures like Ammar al-Hakim. This situation highlighted Meta’s challenges in balancing global growth with effective content moderation and protection. On 16 September 2024, Meta announced it had banned Russian state media outlets from its platforms worldwide due to concerns about "foreign interference activity." This decision followed allegations that RT and its employees funneled $10 million through shell companies to secretly fund influence campaigns on various social media channels. Meta's actions were part of a broader effort to counter Russian covert influence operations, which had intensified since the invasion. At its 2024 Connect conference, Meta presented Orion, its first pair of augmented reality glasses. Though Orion was originally intended to be sold to consumers, the manufacturing process turned out to be too complex and expensive. Instead, the company pivoted to producing a small number of the glasses to be used internally. On 4 October 2024, Meta announced about its new AI model called Movie Gen, capable of generating realistic video and audio clips based on user prompts. Meta stated it would not release Movie Gen for open development, preferring to collaborate directly with content creators and integrate it into its products by the following year. The model was built using a combination of licensed and publicly available datasets. On October 31, 2024, ProPublica published an investigation into deceptive political advertisement scams that sometimes use hundreds of hijacked profiles and facebook pages run by organized networks of scammers. The authors cited spotty enforcement by Meta as a major reason for the extent of the issue. In November 2024, TechCrunch reported that Meta were considering building a $10bn global underwater cable spanning 25,000 miles. In the same month, Meta closed down 2 million accounts on Facebook and Instagram that were linked to scam centers in Myanmar, Laos, Cambodia, the Philippines, and the United Arab Emirates doing pig butchering scams. In December 2024, Meta announced that, beginning February 2025, they would require advertisers to run ads about financial services in Australia to verify information about who are the beneficiary and the payer in a bid to regulate scams. On December 4, 2024, Meta announced it will invest US$10 billion for its largest AI data center in northeast Louisiana, powered by natural gas facilities. On the 11th of that month, Meta experienced a global outage, impacting accounts on all of their social media and messaging applications. Outage reports from DownDetector reached 70,000+ and 100,000+ within minutes for Instagram and Facebook, respectively. In January 2025, Meta announced plans to roll back its diversity, equity, and inclusion (DEI) initiatives, citing shifts in the "legal and policy landscape" in the United States following the 2024 presidential election. The decision followed reports that CEO Mark Zuckerberg sought to align the company more closely with the incoming Trump administration, including changes to content moderation policies and executive leadership. The new content moderation policies continued to bar insults about a person's intellect or mental illness, but made an exception to allow calling LGBTQ people mentally ill because they are gay or transgender. Later that month, Meta agreed to pay $25 million to settle a 2021 lawsuit brought by Donald Trump for suspending his social media accounts after the January 6 riots. Changes to Meta's moderation policies were controversial among its oversight board, with a significant divide in opinion between the board's US conservatives and its global members. In June 2025, Meta Platforms Inc. has decided to make a multibillion-dollar investment into artificial intelligence startup Scale AI. The financing could exceed $10 billion in value which would make it one of the largest private company funding events of all time. In October 2025, it was announced that Meta would be laying off 600 employees in the artificial intelligence unit to perform better and simpler. They referred to their AI unit as "bloated" and are seeking to trim down the department. This mass layoff is going to impact Meta’s AI infrastructure units, Fundamental Artificial Intelligence Research unit (FAIR) and other product-related positions. Mergers and acquisitions Meta has acquired multiple companies (often identified as talent acquisitions). One of its first major acquisitions was in April 2012, when it acquired Instagram for approximately US$1 billion in cash and stock. In October 2013, Facebook, Inc. acquired Onavo, an Israeli mobile web analytics company. In February 2014, Facebook, Inc. announced it would buy mobile messaging company WhatsApp for US$19 billion in cash and stock. The acquisition was completed on October 6. Later that year, Facebook bought Oculus VR for $2.3 billion in cash and stock, which released its first consumer virtual reality headset in 2016. In late November 2019, Facebook, Inc. announced the acquisition of the game developer Beat Games, responsible for developing one of that year's most popular VR games, Beat Saber. In Late 2022, after Facebook Inc rebranded to Meta Platforms Inc, Oculus was rebranded to Meta Quest. In May 2020, Facebook, Inc. announced it had acquired Giphy for a reported cash price of $400 million. It will be integrated with the Instagram team. However, in August 2021, UK's Competition and Markets Authority (CMA) stated that Facebook, Inc. might have to sell Giphy, after an investigation found that the deal between the two companies would harm competition in display advertising market. Facebook, Inc. was fined $70 million by CMA for deliberately failing to report all information regarding the acquisition and the ongoing antitrust investigation. In October 2022, the CMA ruled for a second time that Meta be required to divest Giphy, stating that Meta already controls half of the advertising in the UK. Meta agreed to the sale, though it stated that it disagrees with the decision itself. In May 2023, Giphy was divested to Shutterstock for $53 million. In November 2020, Facebook, Inc. announced that it planned to purchase the customer-service platform and chatbot specialist startup Kustomer to promote companies to use their platform for business. It has been reported that Kustomer valued at slightly over $1 billion. The deal was closed in February 2022 after regulatory approval. In September 2022, Meta acquired Lofelt, a Berlin-based haptic tech startup. In December 2025, it was announced Meta had acquired the AI-wearables startup, Limitless. In the same month, they also acquired another AI startup, Manus AI, for $2 billion. Manus announced in December that its platform had achieved $100mm in recurring revenue just 8 months after its launch and Meta said it will scale the platform to many other businesses. In January 2026, it was announced Meta proposed acquisition of Manus was undergoing preliminary scrutiny by Chinese regulators. The examination concerns the cross-border transfer of artificial intelligence technology developed in China. Lobbying In 2020, Facebook, Inc. spent $19.7 million on lobbying, hiring 79 lobbyists. In 2019, it had spent $16.7 million on lobbying and had a team of 71 lobbyists, up from $12.6 million and 51 lobbyists in 2018. Facebook was the largest spender of lobbying money among the Big Tech companies in 2020. The lobbying team includes top congressional aide John Branscome, who was hired in September 2021, to help the company fend off threats from Democratic lawmakers and the Biden administration. In December 2024, Meta donated $1 million to the inauguration fund for then-President-elect Donald Trump. In 2025, Meta was listed among the donors funding the construction of the White House State Ballroom. Partnerships February 2026, Meta announced a long-term partnership with Nvidia. Censorship In August 2024, Mark Zuckerberg sent a letter to Jim Jordan indicating that during the COVID-19 pandemic the Biden administration repeatedly asked Meta to limit certain COVID-19 content, including humor and satire, on Facebook and Instagram. In 2016 Meta hired Jordana Cutler, formerly an employee at the Israeli Embassy to the United States, as its policy chief for Israel and the Jewish Diaspora. In this role, Cutler pushed for the censorship of accounts belonging to Students for Justice in Palestine chapters in the United States. Critics have said that Cutler's position gives the Israeli government an undue influence over Meta policy, and that few countries have such high levels of contact with Meta policymakers. Following the election of Donald Trump in 2025, various sources noted possible censorship related to the Democratic Party on Instagram and other Meta platforms. In February 2025, a Meta rep flagged journalist Gil Duran's article and other "critiques of tech industry figures" as spam or sensitive content, limiting their reach. In March 2025, Meta attempted to block former employee Sarah Wynn-Williams from promoting or further distributing her memoir, Careless People, that includes allegations of unaddressed sexual harassment in the workplace by senior executives. The New York Times reports that the arbitration is among Meta's most forcible attempts to repudiate a former employee's account of workplace dynamics. Publisher Macmillan reacted to the ruling by the Emergency International Arbitral Tribunal by stating that it will ignore its provisions. As of 15 March 2025[update], hardback and digital versions of Careless People were being offered for sale by major online retailers. From October 2025, Meta began removing and restricting access for accounts related to LGBTQ, reproductive health and abortion information pages on its platforms. Martha Dimitratou, executive director of Repro Uncensored, called Meta's shadow-banning of these issues "One of the biggest waves of censorship we are seeing". Disinformation concerns Since its inception, Meta has been accused of being a host for fake news and misinformation. In the wake of the 2016 United States presidential election, Zuckerberg began to take steps to eliminate the prevalence of fake news, as the platform had been criticized for its potential influence on the outcome of the election. The company initially partnered with ABC News, the Associated Press, FactCheck.org, Snopes and PolitiFact for its fact-checking initiative; as of 2018, it had over 40 fact-checking partners across the world, including The Weekly Standard. A May 2017 review by The Guardian found that the platform's fact-checking initiatives of partnering with third-party fact-checkers and publicly flagging fake news were regularly ineffective, and appeared to be having minimal impact in some cases. In 2018, journalists working as fact-checkers for the company criticized the partnership, stating that it had produced minimal results and that the company had ignored their concerns. In 2024 Meta's decision to continue to disseminate a falsified video of US president Joe Biden, even after it had been proven to be fake, attracted criticism and concern. In January 2025, Meta ended its use of third-party fact-checkers in favor of a user-run community notes system similar to the one used on X. While Zuckerberg supported these changes, saying that the amount of censorship on the platform was excessive, the decision received criticism by fact-checking institutions, stating that the changes would make it more difficult for users to identify misinformation. Meta also faced criticism for weakening its policies on hate speech that were designed to protect minorities and LGBTQ+ individuals from bullying and discrimination. While moving its content review teams from California to Texas, Meta changed their hateful conduct policy to eliminate restrictions on anti-LGBT and anti-immigrant hate speech, as well as explicitly allowing users to accuse LGBT people of being mentally ill or abnormal based on their sexual orientation or gender identity. In January 2025, Meta faced significant criticism for its role in removing LGBTQ+ content from its platforms, amid its broader efforts to address anti-LGBTQ+ hate speech. The removal of LGBTQ+ themes was noted as part of the wider crackdown on content deemed to violate its community guidelines. Meta's content moderation policies, which were designed to combat harmful speech and protect users from discrimination, inadvertently led to the removal or restriction of LGBTQ+ content, particularly posts highlighting LGBTQ+ identities, support, or political issues. According to reports, LGBTQ+ posts, including those that simply celebrated pride or advocated for LGBTQ+ rights, were flagged and removed for reasons that some critics argue were vague or inconsistently applied. Many LGBTQ+ activists and users on Meta's platforms expressed concern that such actions stifled visibility and expression, potentially isolating LGBTQ+ individuals and communities, especially in spaces that were historically important for outreach and support. Lawsuits Numerous lawsuits have been filed against the company, both when it was known as Facebook, Inc., and as Meta Platforms. In March 2020, the Office of the Australian Information Commissioner (OAIC) sued Facebook, for significant and persistent infringements of the rule on privacy involving the Cambridge Analytica fiasco. Every violation of the Privacy Act is subject to a theoretical cumulative liability of $1.7 million. The OAIC estimated that a total of 311,127 Australians had been exposed. On December 8, 2020, the U.S. Federal Trade Commission and 46 states (excluding Alabama, Georgia, South Carolina, and South Dakota), the District of Columbia and the territory of Guam, launched Federal Trade Commission v. Facebook as an antitrust lawsuit against Facebook. The lawsuit concerns Facebook's acquisition of two competitors—Instagram and WhatsApp—and the ensuing monopolistic situation. FTC alleges that Facebook holds monopolistic power in the U.S. social networking market and seeks to force the company to divest from Instagram and WhatsApp to break up the conglomerate. William Kovacic, a former chairman of the Federal Trade Commission, argued the case will be difficult to win as it would require the government to create a counterfactual argument of an internet where the Facebook-WhatsApp-Instagram entity did not exist, and prove that harmed competition or consumers. In November 2025, it was ruled that Meta did not violate antitrust laws and holds no monopoly in the market. On December 24, 2021, a court in Russia fined Meta for $27 million after the company declined to remove unspecified banned content. The fine was reportedly tied to the company's annual revenue in the country. In May 2022, a lawsuit was filed in Kenya against Meta and its local outsourcing company Sama. Allegedly, Meta has poor working conditions in Kenya for workers moderating Facebook posts. According to the lawsuit, 260 screeners were declared redundant with confusing reasoning. The lawsuit seeks financial compensation and an order that outsourced moderators be given the same health benefits and pay scale as Meta employees. In June 2022, 8 lawsuits were filed across the U.S. over the allege that excessive exposure to platforms including Facebook and Instagram has led to attempted or actual suicides, eating disorders and sleeplessness, among other issues. The litigation follows a former Facebook employee's testimony in Congress that the company refused to take responsibility. The company noted that tools have been developed for parents to keep track of their children's activity on Instagram and set time limits, in addition to Meta's "Take a break" reminders. In addition, the company is providing resources specific to eating disorders as well as developing AI to prevent children under the age of 13 signing up for Facebook or Instagram. In June 2022, Meta settled a lawsuit with the US Department of Justice. The lawsuit, which was filed in 2019, alleged that the company enabled housing discrimination through targeted advertising, as it allowed homeowners and landlords to run housing ads excluding people based on sex, race, religion, and other characteristics. The U.S. Department of Justice stated that this was in violation of the Fair Housing Act. Meta was handed a penalty of $115,054 and given until December 31, 2022, to shadow the algorithm tool. In January 2023, Meta was fined €390 million for violations of the European Union General Data Protection Regulation. In May 2023, the European Data Protection Board fined Meta a record €1.2 billion for breaching European Union data privacy laws by transferring personal data of Facebook users to servers in the U.S. In July 2024, Meta agreed to pay the state of Texas US$1.4 billion to settle a lawsuit brought by Texas Attorney General Ken Paxton accusing the company of collecting users' biometric data without consent, setting a record for the largest privacy-related settlement ever obtained by a state attorney general. In October 2024, Meta Platforms faced lawsuits in Japan from 30 plaintiffs who claimed they were defrauded by fake investment ads on Facebook and Instagram, featuring false celebrity endorsements. The plaintiffs are seeking approximately $2.8 million in damages. In April 2025, the Kenyan High Court ruled that a US$2.4 billion lawsuit in which three plaintiffs claim that Facebook inflamed civil violence in Ethiopia in 2021 could proceed. In April 2025, Meta was fined €200 million ($230 million) for breaking the Digital Markets Act, by imposing a “consent or pay” system that forces users to either allow their personal data to be used to target advertisements, or pay a subscription fee for advertising-free versions of Facebook and Instagram. In late April 2025, a case was filed against Meta in Ghana over the alleged psychological distress experienced by content moderators employed to take down disturbing social media content including depictions of murders, extreme violence and child sexual abuse. Meta moved the moderation service to the Ghanaian capital of Accra after legal issues in the previous location Kenya. The new moderation company is Teleperformance, a multinational corporation with a history of worker's rights violation. Reports suggests the conditions are worse here than in the previous Kenyan location, with many workers afraid of speaking out due to fear of returning to conflict zones. Workers reported developing mental illnesses, attempted suicides, and low pay. In 26 January 2026, a New Mexico state court case was filed, suggesting that Mark Zuckerberg approved allowing minors to access artificial intelligence chatbot companions that safety staffers warned were capable of sexual interactions. In 2020, the company UReputation, which had been involved in several cases concerning the management of digital armies[clarification needed], filed a lawsuit against Facebook, accusing it of unlawfully transmitting personal data to third parties. Legal actions were initiated in Tunisia, France, and the United States. In 2025, the United States District court for the Northern District of Georgia approved a discovery procedure, allowing UReputation to access documents and evidence held by Meta. Structure Meta's key management consists of: As of October 2022[update], Meta had 83,553 employees worldwide. As of June 2024[update], Meta's board consisted of the following directors; Meta Platforms is mainly owned by institutional investors, who hold around 80% of all shares. Insiders control the majority of voting shares. The three largest individual investors in 2024 were Mark Zuckerberg, Sheryl Sandberg and Christopher K. Cox. The largest shareholders in late 2024/early 2025 were: Roger McNamee, an early Facebook investor and Zuckerberg's former mentor, said Facebook had "the most centralized decision-making structure I have ever encountered in a large company". Facebook co-founder Chris Hughes has stated that chief executive officer Mark Zuckerberg has too much power, that the company is now a monopoly, and that, as a result, it should be split into multiple smaller companies. In an op-ed in The New York Times, Hughes said he was concerned that Zuckerberg had surrounded himself with a team that did not challenge him, and that it is the U.S. government's job to hold him accountable and curb his "unchecked power". He also said that "Mark's power is unprecedented and un-American." Several U.S. politicians agreed with Hughes. European Union Commissioner for Competition Margrethe Vestager stated that splitting Facebook should be done only as "a remedy of the very last resort", and that it would not solve Facebook's underlying problems. Revenue Facebook ranked No. 34 in the 2020 Fortune 500 list of the largest United States corporations by revenue, with almost $86 billion in revenue most of it coming from advertising. One analysis of 2017 data determined that the company earned US$20.21 per user from advertising. According to New York, since its rebranding, Meta has reportedly lost $500 billion as a result of new privacy measures put in place by companies such as Apple and Google which prevents Meta from gathering users' data. In February 2015, Facebook announced it had reached two million active advertisers, with most of the gain coming from small businesses. An active advertiser was defined as an entity that had advertised on the Facebook platform in the last 28 days. In March 2016, Facebook announced it had reached three million active advertisers with more than 70% from outside the United States. Prices for advertising follow a variable pricing model based on auctioning ad placements, and potential engagement levels of the advertisement itself. Similar to other online advertising platforms like Google and Twitter, targeting of advertisements is one of the chief merits of digital advertising compared to traditional media. Marketing on Meta is employed through two methods based on the viewing habits, likes and shares, and purchasing data of the audience, namely targeted audiences and "look alike" audiences. The U.S. IRS challenged the valuation Facebook used when it transferred IP from the U.S. to Facebook Ireland (now Meta Platforms Ireland) in 2010 (which Facebook Ireland then revalued higher before charging out), as it was building its double Irish tax structure. The case is ongoing and Meta faces a potential fine of $3–5bn. The U.S. Tax Cuts and Jobs Act of 2017 changed Facebook's global tax calculations. Meta Platforms Ireland is subject to the U.S. GILTI tax of 10.5% on global intangible profits (i.e. Irish profits). On the basis that Meta Platforms Ireland Limited is paying some tax, the effective minimum US tax for Facebook Ireland will be circa 11%. In contrast, Meta Platforms Inc. would incur a special IP tax rate of 13.125% (the FDII rate) if its Irish business relocated to the U.S. Tax relief in the U.S. (21% vs. Irish at the GILTI rate) and accelerated capital expensing, would make this effective U.S. rate around 12%. The insignificance of the U.S./Irish tax difference was demonstrated when Facebook moved 1.5bn non-EU accounts to the U.S. to limit exposure to GDPR. Facilities Users outside of the U.S. and Canada contract with Meta's Irish subsidiary, Meta Platforms Ireland Limited (formerly Facebook Ireland Limited), allowing Meta to avoid US taxes for all users in Europe, Asia, Australia, Africa and South America. Meta is making use of the Double Irish arrangement which allows it to pay 2–3% corporation tax on all international revenue. In 2010, Facebook opened its fourth office, in Hyderabad, India, which houses online advertising and developer support teams and provides support to users and advertisers. In India, Meta is registered as Facebook India Online Services Pvt Ltd. It also has offices or planned sites in Chittagong, Bangladesh; Dublin, Ireland; and Austin, Texas, among other cities. Facebook opened its London headquarters in 2017 in Fitzrovia in central London. Facebook opened an office in Cambridge, Massachusetts in 2018. The offices were initially home to the "Connectivity Lab", a group focused on bringing Internet access to those who do not have access to the Internet. In April 2019, Facebook opened its Taiwan headquarters in Taipei. In March 2022, Meta opened new regional headquarters in Dubai. In September 2023, it was reported that Meta had paid £149m to British Land to break the lease on Triton Square London office. Meta reportedly had another 18 years left on its lease on the site. As of 2023, Facebook operated 21 data centers. It committed to purchase 100% renewable energy and to reduce its greenhouse gas emissions 75% by 2020. Its data center technologies include Fabric Aggregator, a distributed network system that accommodates larger regions and varied traffic patterns. Reception US Representative Alexandria Ocasio-Cortez responded in a tweet to Zuckerberg's announcement about Meta, saying: "Meta as in 'we are a cancer to democracy metastasizing into a global surveillance and propaganda machine for boosting authoritarian regimes and destroying civil society ... for profit!'" Ex-Facebook employee Frances Haugen and whistleblower behind the Facebook Papers responded to the rebranding efforts by expressing doubts about the company's ability to improve while led by Mark Zuckerberg, and urged the chief executive officer to resign. In November 2021, a video published by Inspired by Iceland went viral, in which a Zuckerberg look-alike promoted the Icelandverse, a place of "enhanced actual reality without silly looking headsets". In a December 2021 interview, SpaceX and Tesla chief executive officer Elon Musk said he could not see a compelling use-case for the VR-driven metaverse, adding: "I don't see someone strapping a frigging screen to their face all day." In January 2022, Louise Eccles of The Sunday Times logged into the metaverse with the intention of making a video guide. She wrote: Initially, my experience with the Oculus went well. I attended work meetings as an avatar and tried an exercise class set in the streets of Paris. The headset enabled me to feel the thrill of carving down mountains on a snowboard and the adrenaline rush of climbing a mountain without ropes. Yet switching to the social apps, where you mingle with strangers also using VR headsets, it was at times predatory and vile. Eccles described being sexually harassed by another user, as well as "accents from all over the world, American, Indian, English, Australian, using racist, sexist, homophobic and transphobic language". She also encountered users as young as 7 years old on the platform, despite Oculus headsets being intended for users over 13. See also References External links 37°29′06″N 122°08′54″W / 37.48500°N 122.14833°W / 37.48500; -122.14833 |
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[SOURCE: https://en.wikipedia.org/wiki/Internet#cite_note-196] | [TOKENS: 9291] |
Contents Internet The Internet (or internet)[a] is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP)[b] to communicate between networks and devices. It is a network of networks that comprises private, public, academic, business, and government networks of local to global scope, linked by electronic, wireless, and optical networking technologies. The Internet carries a vast range of information services and resources, such as the interlinked hypertext documents and applications of the World Wide Web (WWW), electronic mail, discussion groups, internet telephony, streaming media and file sharing. Most traditional communication media, including telephone, radio, television, paper mail, newspapers, and print publishing, have been transformed by the Internet, giving rise to new media such as email, online music, digital newspapers, news aggregators, and audio and video streaming websites. The Internet has enabled and accelerated new forms of personal interaction through instant messaging, Internet forums, and social networking services. Online shopping has also grown to occupy a significant market across industries, enabling firms to extend brick and mortar presences to serve larger markets. Business-to-business and financial services on the Internet affect supply chains across entire industries. The origins of the Internet date back to research that enabled the time-sharing of computer resources, the development of packet switching, and the design of computer networks for data communication. The set of communication protocols to enable internetworking on the Internet arose from research and development commissioned in the 1970s by the Defense Advanced Research Projects Agency (DARPA) of the United States Department of Defense in collaboration with universities and researchers across the United States and in the United Kingdom and France. The Internet has no single centralized governance in either technological implementation or policies for access and usage. Each constituent network sets its own policies. The overarching definitions of the two principal name spaces on the Internet, the Internet Protocol address (IP address) space and the Domain Name System (DNS), are directed by a maintainer organization, the Internet Corporation for Assigned Names and Numbers (ICANN). The technical underpinning and standardization of the core protocols is an activity of the non-profit Internet Engineering Task Force (IETF). Terminology The word internetted was used as early as 1849, meaning interconnected or interwoven. The word Internet was used in 1945 by the United States War Department in a radio operator's manual, and in 1974 as the shorthand form of Internetwork. Today, the term Internet most commonly refers to the global system of interconnected computer networks, though it may also refer to any group of smaller networks. The word Internet may be capitalized as a proper noun, although this is becoming less common. This reflects the tendency in English to capitalize new terms and move them to lowercase as they become familiar. The word is sometimes still capitalized to distinguish the global internet from smaller networks, though many publications, including the AP Stylebook since 2016, recommend the lowercase form in every case. In 2016, the Oxford English Dictionary found that, based on a study of around 2.5 billion printed and online sources, "Internet" was capitalized in 54% of cases. The terms Internet and World Wide Web are often used interchangeably; it is common to speak of "going on the Internet" when using a web browser to view web pages. However, the World Wide Web, or the Web, is only one of a large number of Internet services. It is the global collection of web pages, documents and other web resources linked by hyperlinks and URLs. History In the 1960s, computer scientists began developing systems for time-sharing of computer resources. J. C. R. Licklider proposed the idea of a universal network while working at Bolt Beranek & Newman and, later, leading the Information Processing Techniques Office at the Advanced Research Projects Agency (ARPA) of the United States Department of Defense. Research into packet switching,[c] one of the fundamental Internet technologies, started in the work of Paul Baran at RAND in the early 1960s and, independently, Donald Davies at the United Kingdom's National Physical Laboratory in 1965. After the Symposium on Operating Systems Principles in 1967, packet switching from the proposed NPL network was incorporated into the design of the ARPANET, an experimental resource sharing network proposed by ARPA. ARPANET development began with two network nodes which were interconnected between the University of California, Los Angeles and the Stanford Research Institute on 29 October 1969. The third site was at the University of California, Santa Barbara, followed by the University of Utah. By the end of 1971, 15 sites were connected to the young ARPANET. Thereafter, the ARPANET gradually developed into a decentralized communications network, connecting remote centers and military bases in the United States. Other user networks and research networks, such as the Merit Network and CYCLADES, were developed in the late 1960s and early 1970s. Early international collaborations for the ARPANET were rare. Connections were made in 1973 to Norway (NORSAR and, later, NDRE) and to Peter Kirstein's research group at University College London, which provided a gateway to British academic networks, the first internetwork for resource sharing. ARPA projects, the International Network Working Group and commercial initiatives led to the development of various protocols and standards by which multiple separate networks could become a single network, or a network of networks. In 1974, Vint Cerf at Stanford University and Bob Kahn at DARPA published a proposal for "A Protocol for Packet Network Intercommunication". Cerf and his graduate students used the term internet as a shorthand for internetwork in RFC 675. The Internet Experiment Notes and later RFCs repeated this use. The work of Louis Pouzin and Robert Metcalfe had important influences on the resulting TCP/IP design. National PTTs and commercial providers developed the X.25 standard and deployed it on public data networks. The ARPANET initially served as a backbone for the interconnection of regional academic and military networks in the United States to enable resource sharing. Access to the ARPANET was expanded in 1981 when the National Science Foundation (NSF) funded the Computer Science Network (CSNET). In 1982, the Internet Protocol Suite (TCP/IP) was standardized, which facilitated worldwide proliferation of interconnected networks. TCP/IP network access expanded again in 1986 when the National Science Foundation Network (NSFNet) provided access to supercomputer sites in the United States for researchers, first at speeds of 56 kbit/s and later at 1.5 Mbit/s and 45 Mbit/s. The NSFNet expanded into academic and research organizations in Europe, Australia, New Zealand and Japan in 1988–89. Although other network protocols such as UUCP and PTT public data networks had global reach well before this time, this marked the beginning of the Internet as an intercontinental network. Commercial Internet service providers emerged in 1989 in the United States and Australia. The ARPANET was decommissioned in 1990. The linking of commercial networks and enterprises by the early 1990s, as well as the advent of the World Wide Web, marked the beginning of the transition to the modern Internet. Steady advances in semiconductor technology and optical networking created new economic opportunities for commercial involvement in the expansion of the network in its core and for delivering services to the public. In mid-1989, MCI Mail and Compuserve established connections to the Internet, delivering email and public access products to the half million users of the Internet. Just months later, on 1 January 1990, PSInet launched an alternate Internet backbone for commercial use; one of the networks that added to the core of the commercial Internet of later years. In March 1990, the first high-speed T1 (1.5 Mbit/s) link between the NSFNET and Europe was installed between Cornell University and CERN, allowing much more robust communications than were capable with satellites. Later in 1990, Tim Berners-Lee began writing WorldWideWeb, the first web browser, after two years of lobbying CERN management. By Christmas 1990, Berners-Lee had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP) 0.9, the HyperText Markup Language (HTML), the first Web browser (which was also an HTML editor and could access Usenet newsgroups and FTP files), the first HTTP server software (later known as CERN httpd), the first web server, and the first Web pages that described the project itself. In 1991 the Commercial Internet eXchange was founded, allowing PSInet to communicate with the other commercial networks CERFnet and Alternet. Stanford Federal Credit Union was the first financial institution to offer online Internet banking services to all of its members in October 1994. In 1996, OP Financial Group, also a cooperative bank, became the second online bank in the world and the first in Europe. By 1995, the Internet was fully commercialized in the U.S. when the NSFNet was decommissioned, removing the last restrictions on use of the Internet to carry commercial traffic. As technology advanced and commercial opportunities fueled reciprocal growth, the volume of Internet traffic started experiencing similar characteristics as that of the scaling of MOS transistors, exemplified by Moore's law, doubling every 18 months. This growth, formalized as Edholm's law, was catalyzed by advances in MOS technology, laser light wave systems, and noise performance. Since 1995, the Internet has tremendously impacted culture and commerce, including the rise of near-instant communication by email, instant messaging, telephony (Voice over Internet Protocol or VoIP), two-way interactive video calls, and the World Wide Web. Increasing amounts of data are transmitted at higher and higher speeds over fiber optic networks operating at 1 Gbit/s, 10 Gbit/s, or more. The Internet continues to grow, driven by ever-greater amounts of online information and knowledge, commerce, entertainment and social networking services. During the late 1990s, it was estimated that traffic on the public Internet grew by 100 percent per year, while the mean annual growth in the number of Internet users was thought to be between 20% and 50%. This growth is often attributed to the lack of central administration, which allows organic growth of the network, as well as the non-proprietary nature of the Internet protocols, which encourages vendor interoperability and prevents any one company from exerting too much control over the network. In November 2006, the Internet was included on USA Today's list of the New Seven Wonders. As of 31 March 2011[update], the estimated total number of Internet users was 2.095 billion (30% of world population). It is estimated that in 1993 the Internet carried only 1% of the information flowing through two-way telecommunication. By 2000 this figure had grown to 51%, and by 2007 more than 97% of all telecommunicated information was carried over the Internet. Modern smartphones can access the Internet through cellular carrier networks, and internet usage by mobile and tablet devices exceeded desktop worldwide for the first time in October 2016. As of 2018[update], 80% of the world's population were covered by a 4G network. The International Telecommunication Union (ITU) estimated that, by the end of 2017, 48% of individual users regularly connect to the Internet, up from 34% in 2012. Mobile Internet connectivity has played an important role in expanding access in recent years, especially in Asia and the Pacific and in Africa. The number of unique mobile cellular subscriptions increased from 3.9 billion in 2012 to 4.8 billion in 2016, two-thirds of the world's population, with more than half of subscriptions located in Asia and the Pacific. The limits that users face on accessing information via mobile applications coincide with a broader process of fragmentation of the Internet. Fragmentation restricts access to media content and tends to affect the poorest users the most. One solution, zero-rating, is the practice of Internet service providers allowing users free connectivity to access specific content or applications without cost. Social impact The Internet has enabled new forms of social interaction, activities, and social associations, giving rise to the scholarly study of the sociology of the Internet. Between 2000 and 2009, the number of Internet users globally rose from 390 million to 1.9 billion. By 2010, 22% of the world's population had access to computers with 1 billion Google searches every day, 300 million Internet users reading blogs, and 2 billion videos viewed daily on YouTube. In 2014 the world's Internet users surpassed 3 billion or 44 percent of world population, but two-thirds came from the richest countries, with 78 percent of Europeans using the Internet, followed by 57 percent of the Americas. However, by 2018, Asia alone accounted for 51% of all Internet users, with 2.2 billion out of the 4.3 billion Internet users in the world. China's Internet users surpassed a major milestone in 2018, when the country's Internet regulatory authority, China Internet Network Information Centre, announced that China had 802 million users. China was followed by India, with some 700 million users, with the United States third with 275 million users. However, in terms of penetration, in 2022, China had a 70% penetration rate compared to India's 60% and the United States's 90%. In 2022, 54% of the world's Internet users were based in Asia, 14% in Europe, 7% in North America, 10% in Latin America and the Caribbean, 11% in Africa, 4% in the Middle East and 1% in Oceania. In 2019, Kuwait, Qatar, the Falkland Islands, Bermuda and Iceland had the highest Internet penetration by the number of users, with 93% or more of the population with access. As of 2022, it was estimated that 5.4 billion people use the Internet, more than two-thirds of the world's population. Early computer systems were limited to the characters in the American Standard Code for Information Interchange (ASCII), a subset of the Latin alphabet. After English (27%), the most requested languages on the World Wide Web are Chinese (25%), Spanish (8%), Japanese (5%), Portuguese and German (4% each), Arabic, French and Russian (3% each), and Korean (2%). Modern character encoding standards, such as Unicode, allow for development and communication in the world's widely used languages. However, some glitches such as mojibake (incorrect display of some languages' characters) still remain. Several neologisms exist that refer to Internet users: Netizen (as in "citizen of the net") refers to those actively involved in improving online communities, the Internet in general or surrounding political affairs and rights such as free speech, Internaut refers to operators or technically highly capable users of the Internet, digital citizen refers to a person using the Internet in order to engage in society, politics, and government participation. The Internet allows greater flexibility in working hours and location, especially with the spread of unmetered high-speed connections. The Internet can be accessed almost anywhere by numerous means, including through mobile Internet devices. Mobile phones, datacards, handheld game consoles and cellular routers allow users to connect to the Internet wirelessly.[citation needed] Educational material at all levels from pre-school (e.g. CBeebies) to post-doctoral (e.g. scholarly literature through Google Scholar) is available on websites. The internet has facilitated the development of virtual universities and distance education, enabling both formal and informal education. The Internet allows researchers to conduct research remotely via virtual laboratories, with profound changes in reach and generalizability of findings as well as in communication between scientists and in the publication of results. By the late 2010s the Internet had been described as "the main source of scientific information "for the majority of the global North population".: 111 Wikis have also been used in the academic community for sharing and dissemination of information across institutional and international boundaries. In those settings, they have been found useful for collaboration on grant writing, strategic planning, departmental documentation, and committee work. The United States Patent and Trademark Office uses a wiki to allow the public to collaborate on finding prior art relevant to examination of pending patent applications. Queens, New York has used a wiki to allow citizens to collaborate on the design and planning of a local park. The English Wikipedia has the largest user base among wikis on the World Wide Web and ranks in the top 10 among all sites in terms of traffic. The Internet has been a major outlet for leisure activity since its inception, with entertaining social experiments such as MUDs and MOOs being conducted on university servers, and humor-related Usenet groups receiving much traffic. Many Internet forums have sections devoted to games and funny videos. Another area of leisure activity on the Internet is multiplayer gaming. This form of recreation creates communities, where people of all ages and origins enjoy the fast-paced world of multiplayer games. These range from MMORPG to first-person shooters, from role-playing video games to online gambling. While online gaming has been around since the 1970s, modern modes of online gaming began with subscription services such as GameSpy and MPlayer. Streaming media is the real-time delivery of digital media for immediate consumption or enjoyment by end users. Streaming companies (such as Netflix, Disney+, Amazon's Prime Video, Mubi, Hulu, and Apple TV+) now dominate the entertainment industry, eclipsing traditional broadcasters. Audio streamers such as Spotify and Apple Music also have significant market share in the audio entertainment market. Video sharing websites are also a major factor in the entertainment ecosystem. YouTube was founded on 15 February 2005 and is now the leading website for free streaming video with more than two billion users. It uses a web player to stream and show video files. YouTube users watch hundreds of millions, and upload hundreds of thousands, of videos daily. Other video sharing websites include Vimeo, Instagram and TikTok.[citation needed] Although many governments have attempted to restrict both Internet pornography and online gambling, this has generally failed to stop their widespread popularity. A number of advertising-funded ostensible video sharing websites known as "tube sites" have been created to host shared pornographic video content. Due to laws requiring the documentation of the origin of pornography, these websites now largely operate in conjunction with pornographic movie studios and their own independent creator networks, acting as de-facto video streaming services. Major players in this field include the market leader Aylo, the operator of PornHub and numerous other branded sites, as well as other independent operators such as xHamster and Xvideos. As of 2023[update], Internet traffic to pornographic video sites rivalled that of mainstream video streaming and sharing services. Remote work is facilitated by tools such as groupware, virtual private networks, conference calling, videotelephony, and VoIP so that work may be performed from any location, such as the worker's home.[citation needed] The spread of low-cost Internet access in developing countries has opened up new possibilities for peer-to-peer charities, which allow individuals to contribute small amounts to charitable projects for other individuals. Websites, such as DonorsChoose and GlobalGiving, allow small-scale donors to direct funds to individual projects of their choice. A popular twist on Internet-based philanthropy is the use of peer-to-peer lending for charitable purposes. Kiva pioneered this concept in 2005, offering the first web-based service to publish individual loan profiles for funding. The low cost and nearly instantaneous sharing of ideas, knowledge, and skills have made collaborative work dramatically easier, with the help of collaborative software, which allow groups to easily form, cheaply communicate, and share ideas. An example of collaborative software is the free software movement, which has produced, among other things, Linux, Mozilla Firefox, and OpenOffice.org (later forked into LibreOffice).[citation needed] Content management systems allow collaborating teams to work on shared sets of documents simultaneously without accidentally destroying each other's work.[citation needed] The internet also allows for cloud computing, virtual private networks, remote desktops, and remote work.[citation needed] The online disinhibition effect describes the tendency of many individuals to behave more stridently or offensively online than they would in person. A significant number of feminist women have been the target of various forms of harassment, including insults and hate speech, to, in extreme cases, rape and death threats, in response to posts they have made on social media. Social media companies have been criticized in the past for not doing enough to aid victims of online abuse. Children also face dangers online such as cyberbullying and approaches by sexual predators, who sometimes pose as children themselves. Due to naivety, they may also post personal information about themselves online, which could put them or their families at risk unless warned not to do so. Many parents choose to enable Internet filtering or supervise their children's online activities in an attempt to protect their children from pornography or violent content on the Internet. The most popular social networking services commonly forbid users under the age of 13. However, these policies can be circumvented by registering an account with a false birth date, and a significant number of children aged under 13 join such sites.[citation needed] Social networking services for younger children, which claim to provide better levels of protection for children, also exist. Internet usage has been correlated to users' loneliness. Lonely people tend to use the Internet as an outlet for their feelings and to share their stories with others, such as in the "I am lonely will anyone speak to me" thread.[citation needed] Cyberslacking can become a drain on corporate resources; employees spend a significant amount of time surfing the Web while at work. Internet addiction disorder is excessive computer use that interferes with daily life. Nicholas G. Carr believes that Internet use has other effects on individuals, for instance improving skills of scan-reading and interfering with the deep thinking that leads to true creativity. Electronic business encompasses business processes spanning the entire value chain: purchasing, supply chain management, marketing, sales, customer service, and business relationship. E-commerce seeks to add revenue streams using the Internet to build and enhance relationships with clients and partners. According to International Data Corporation, the size of worldwide e-commerce, when global business-to-business and -consumer transactions are combined, equate to $16 trillion in 2013. A report by Oxford Economics added those two together to estimate the total size of the digital economy at $20.4 trillion, equivalent to roughly 13.8% of global sales. While much has been written of the economic advantages of Internet-enabled commerce, there is also evidence that some aspects of the Internet such as maps and location-aware services may serve to reinforce economic inequality and the digital divide. Electronic commerce may be responsible for consolidation and the decline of mom-and-pop, brick and mortar businesses resulting in increases in income inequality. A 2013 Institute for Local Self-Reliance report states that brick-and-mortar retailers employ 47 people for every $10 million in sales, while Amazon employs only 14. Similarly, the 700-employee room rental start-up Airbnb was valued at $10 billion in 2014, about half as much as Hilton Worldwide, which employs 152,000 people. At that time, Uber employed 1,000 full-time employees and was valued at $18.2 billion, about the same valuation as Avis Rent a Car and The Hertz Corporation combined, which together employed almost 60,000 people. Advertising on popular web pages can be lucrative, and e-commerce. Online advertising is a form of marketing and advertising which uses the Internet to deliver promotional marketing messages to consumers. It includes email marketing, search engine marketing (SEM), social media marketing, many types of display advertising (including web banner advertising), and mobile advertising. In 2011, Internet advertising revenues in the United States surpassed those of cable television and nearly exceeded those of broadcast television.: 19 Many common online advertising practices are controversial and increasingly subject to regulation. The Internet has achieved new relevance as a political tool. The presidential campaign of Howard Dean in 2004 in the United States was notable for its success in soliciting donation via the Internet. Many political groups use the Internet to achieve a new method of organizing for carrying out their mission, having given rise to Internet activism. Social media websites, such as Facebook and Twitter, helped people organize the Arab Spring, by helping activists organize protests, communicate grievances, and disseminate information. Many have understood the Internet as an extension of the Habermasian notion of the public sphere, observing how network communication technologies provide something like a global civic forum. However, incidents of politically motivated Internet censorship have now been recorded in many countries, including western democracies. E-government is the use of technological communications devices, such as the Internet, to provide public services to citizens and other persons in a country or region. E-government offers opportunities for more direct and convenient citizen access to government and for government provision of services directly to citizens. Cybersectarianism is a new organizational form that involves: highly dispersed small groups of practitioners that may remain largely anonymous within the larger social context and operate in relative secrecy, while still linked remotely to a larger network of believers who share a set of practices and texts, and often a common devotion to a particular leader. Overseas supporters provide funding and support; domestic practitioners distribute tracts, participate in acts of resistance, and share information on the internal situation with outsiders. Collectively, members and practitioners of such sects construct viable virtual communities of faith, exchanging personal testimonies and engaging in the collective study via email, online chat rooms, and web-based message boards. In particular, the British government has raised concerns about the prospect of young British Muslims being indoctrinated into Islamic extremism by material on the Internet, being persuaded to join terrorist groups such as the so-called "Islamic State", and then potentially committing acts of terrorism on returning to Britain after fighting in Syria or Iraq.[citation needed] Applications and services The Internet carries many applications and services, most prominently the World Wide Web, including social media, electronic mail, mobile applications, multiplayer online games, Internet telephony, file sharing, and streaming media services. The World Wide Web is a global collection of documents, images, multimedia, applications, and other resources, logically interrelated by hyperlinks and referenced with Uniform Resource Identifiers (URIs), which provide a global system of named references. URIs symbolically identify services, web servers, databases, and the documents and resources that they can provide. HyperText Transfer Protocol (HTTP) is the main access protocol of the World Wide Web. Web services also use HTTP for communication between software systems for information transfer, sharing and exchanging business data and logistics and is one of many languages or protocols that can be used for communication on the Internet. World Wide Web browser software, such as Microsoft Edge, Mozilla Firefox, Opera, Apple's Safari, and Google Chrome, enable users to navigate from one web page to another via the hyperlinks embedded in the documents. These documents may also contain computer data, including graphics, sounds, text, video, multimedia and interactive content. Client-side scripts can include animations, games, office applications and scientific demonstrations. Email is an important communications service available via the Internet. The concept of sending electronic text messages between parties, analogous to mailing letters or memos, predates the creation of the Internet. Internet telephony is a common communications service realized with the Internet. The name of the principal internetworking protocol, the Internet Protocol, lends its name to voice over Internet Protocol (VoIP).[citation needed] VoIP systems now dominate many markets, being as easy and convenient as a traditional telephone, while having substantial cost savings, especially over long distances. File sharing is the practice of transferring large amounts of data in the form of computer files across the Internet, for example via file servers. The load of bulk downloads to many users can be eased by the use of "mirror" servers or peer-to-peer networks. Access to the file may be controlled by user authentication, the transit of the file over the Internet may be obscured by encryption, and money may change hands for access to the file. The price can be paid by the remote charging of funds from, for example, a credit card whose details are also passed—usually fully encrypted—across the Internet. The origin and authenticity of the file received may be checked by a digital signature. Governance The Internet is a global network that comprises many voluntarily interconnected autonomous networks. It operates without a central governing body. The technical underpinning and standardization of the core protocols (IPv4 and IPv6) is an activity of the Internet Engineering Task Force (IETF), a non-profit organization of loosely affiliated international participants that anyone may associate with by contributing technical expertise. While the hardware components in the Internet infrastructure can often be used to support other software systems, it is the design and the standardization process of the software that characterizes the Internet and provides the foundation for its scalability and success. The responsibility for the architectural design of the Internet software systems has been assumed by the IETF. The IETF conducts standard-setting work groups, open to any individual, about the various aspects of Internet architecture. The resulting contributions and standards are published as Request for Comments (RFC) documents on the IETF web site. The principal methods of networking that enable the Internet are contained in specially designated RFCs that constitute the Internet Standards. Other less rigorous documents are simply informative, experimental, or historical, or document the best current practices when implementing Internet technologies. To maintain interoperability, the principal name spaces of the Internet are administered by the Internet Corporation for Assigned Names and Numbers (ICANN). ICANN is governed by an international board of directors drawn from across the Internet technical, business, academic, and other non-commercial communities. The organization coordinates the assignment of unique identifiers for use on the Internet, including domain names, IP addresses, application port numbers in the transport protocols, and many other parameters. Globally unified name spaces are essential for maintaining the global reach of the Internet. This role of ICANN distinguishes it as perhaps the only central coordinating body for the global Internet. The National Telecommunications and Information Administration, an agency of the United States Department of Commerce, had final approval over changes to the DNS root zone until the IANA stewardship transition on 1 October 2016. Regional Internet registries (RIRs) were established for five regions of the world to assign IP address blocks and other Internet parameters to local registries, such as Internet service providers, from a designated pool of addresses set aside for each region:[citation needed] The Internet Society (ISOC) was founded in 1992 with a mission to "assure the open development, evolution and use of the Internet for the benefit of all people throughout the world". Its members include individuals as well as corporations, organizations, governments, and universities. Among other activities ISOC provides an administrative home for a number of less formally organized groups that are involved in developing and managing the Internet, including: the Internet Engineering Task Force (IETF), Internet Architecture Board (IAB), Internet Engineering Steering Group (IESG), Internet Research Task Force (IRTF), and Internet Research Steering Group (IRSG). On 16 November 2005, the United Nations-sponsored World Summit on the Information Society in Tunis established the Internet Governance Forum (IGF) to discuss Internet-related issues.[citation needed] Infrastructure The communications infrastructure of the Internet consists of its hardware components and a system of software layers that control various aspects of the architecture. As with any computer network, the Internet physically consists of routers, media (such as cabling and radio links), repeaters, and modems. However, as an example of internetworking, many of the network nodes are not necessarily Internet equipment per se. Internet packets are carried by other full-fledged networking protocols, with the Internet acting as a homogeneous networking standard, running across heterogeneous hardware, with the packets guided to their destinations by IP routers.[citation needed] Internet service providers (ISPs) establish worldwide connectivity between individual networks at various levels of scope. At the top of the routing hierarchy are the tier 1 networks, large telecommunication companies that exchange traffic directly with each other via very high speed fiber-optic cables and governed by peering agreements. Tier 2 and lower-level networks buy Internet transit from other providers to reach at least some parties on the global Internet, though they may also engage in peering. End-users who only access the Internet when needed to perform a function or obtain information, represent the bottom of the routing hierarchy.[citation needed] An ISP may use a single upstream provider for connectivity, or implement multihoming to achieve redundancy and load balancing. Internet exchange points are major traffic exchanges with physical connections to multiple ISPs. Large organizations, such as academic institutions, large enterprises, and governments, may perform the same function as ISPs, engaging in peering and purchasing transit on behalf of their internal networks. Research networks tend to interconnect with large subnetworks such as GEANT, GLORIAD, Internet2, and the UK's national research and education network, JANET.[citation needed] Common methods of Internet access by users include broadband over coaxial cable, fiber optics or copper wires, Wi-Fi, satellite, and cellular telephone technology.[citation needed] Grassroots efforts have led to wireless community networks. Commercial Wi-Fi services that cover large areas are available in many cities, such as New York, London, Vienna, Toronto, San Francisco, Philadelphia, Chicago and Pittsburgh. Most servers that provide internet services are today hosted in data centers, and content is often accessed through high-performance content delivery networks. Colocation centers often host private peering connections between their customers, internet transit providers, cloud providers, meet-me rooms for connecting customers together, Internet exchange points, and landing points and terminal equipment for fiber optic submarine communication cables, connecting the internet. Internet Protocol Suite The Internet standards describe a framework known as the Internet protocol suite (also called TCP/IP, based on the first two components.) This is a suite of protocols that are ordered into a set of four conceptional layers by the scope of their operation, originally documented in RFC 1122 and RFC 1123:[citation needed] The most prominent component of the Internet model is the Internet Protocol. IP enables internetworking, essentially establishing the Internet itself. Two versions of the Internet Protocol exist, IPv4 and IPv6.[citation needed] Aside from the complex array of physical connections that make up its infrastructure, the Internet is facilitated by bi- or multi-lateral commercial contracts (e.g., peering agreements), and by technical specifications or protocols that describe the exchange of data over the network.[citation needed] For locating individual computers on the network, the Internet provides IP addresses. IP addresses are used by the Internet infrastructure to direct internet packets to their destinations. They consist of fixed-length numbers, which are found within the packet. IP addresses are generally assigned to equipment either automatically via Dynamic Host Configuration Protocol, or are configured.[citation needed] Domain Name Systems convert user-inputted domain names (e.g. "en.wikipedia.org") into IP addresses.[citation needed] Internet Protocol version 4 (IPv4) defines an IP address as a 32-bit number. IPv4 is the initial version used on the first generation of the Internet and is still in dominant use. It was designed in 1981 to address up to ≈4.3 billion (109) hosts. However, the explosive growth of the Internet has led to IPv4 address exhaustion, which entered its final stage in 2011, when the global IPv4 address allocation pool was exhausted. Because of the growth of the Internet and the depletion of available IPv4 addresses, a new version of IP IPv6, was developed in the mid-1990s, which provides vastly larger addressing capabilities and more efficient routing of Internet traffic. IPv6 uses 128 bits for the IP address and was standardized in 1998. IPv6 deployment has been ongoing since the mid-2000s and is currently in growing deployment around the world, since Internet address registries began to urge all resource managers to plan rapid adoption and conversion. By design, IPv6 is not directly interoperable with IPv4. Instead, it establishes a parallel version of the Internet not directly accessible with IPv4 software. Thus, translation facilities exist for internetworking, and some nodes have duplicate networking software for both networks. Essentially all modern computer operating systems support both versions of the Internet Protocol.[citation needed] Network infrastructure, however, has been lagging in this development.[citation needed] A subnet or subnetwork is a logical subdivision of an IP network.: 1, 16 Computers that belong to a subnet are addressed with an identical most-significant bit-group in their IP addresses. This results in the logical division of an IP address into two fields, the network number or routing prefix and the rest field or host identifier. The rest field is an identifier for a specific host or network interface.[citation needed] The routing prefix may be expressed in Classless Inter-Domain Routing (CIDR) notation written as the first address of a network, followed by a slash character (/), and ending with the bit-length of the prefix. For example, 198.51.100.0/24 is the prefix of the Internet Protocol version 4 network starting at the given address, having 24 bits allocated for the network prefix, and the remaining 8 bits reserved for host addressing. Addresses in the range 198.51.100.0 to 198.51.100.255 belong to this network. The IPv6 address specification 2001:db8::/32 is a large address block with 296 addresses, having a 32-bit routing prefix.[citation needed] For IPv4, a network may also be characterized by its subnet mask or netmask, which is the bitmask that when applied by a bitwise AND operation to any IP address in the network, yields the routing prefix. Subnet masks are also expressed in dot-decimal notation like an address. For example, 255.255.255.0 is the subnet mask for the prefix 198.51.100.0/24.[citation needed] Computers and routers use routing tables in their operating system to forward IP packets to reach a node on a different subnetwork. Routing tables are maintained by manual configuration or automatically by routing protocols. End-nodes typically use a default route that points toward an ISP providing transit, while ISP routers use the Border Gateway Protocol to establish the most efficient routing across the complex connections of the global Internet.[citation needed] The default gateway is the node that serves as the forwarding host (router) to other networks when no other route specification matches the destination IP address of a packet. Security Internet resources, hardware, and software components are the target of criminal or malicious attempts to gain unauthorized control to cause interruptions, commit fraud, engage in blackmail or access private information. Malware is malicious software used and distributed via the Internet. It includes computer viruses which are copied with the help of humans, computer worms which copy themselves automatically, software for denial of service attacks, ransomware, botnets, and spyware that reports on the activity and typing of users.[citation needed] Usually, these activities constitute cybercrime. Defense theorists have also speculated about the possibilities of hackers using cyber warfare using similar methods on a large scale. Malware poses serious problems to individuals and businesses on the Internet. According to Symantec's 2018 Internet Security Threat Report (ISTR), malware variants number has increased to 669,947,865 in 2017, which is twice as many malware variants as in 2016. Cybercrime, which includes malware attacks as well as other crimes committed by computer, was predicted to cost the world economy US$6 trillion in 2021, and is increasing at a rate of 15% per year. Since 2021, malware has been designed to target computer systems that run critical infrastructure such as the electricity distribution network. Malware can be designed to evade antivirus software detection algorithms. The vast majority of computer surveillance involves the monitoring of data and traffic on the Internet. In the United States for example, under the Communications Assistance For Law Enforcement Act, all phone calls and broadband Internet traffic (emails, web traffic, instant messaging, etc.) are required to be available for unimpeded real-time monitoring by Federal law enforcement agencies. Under the Act, all U.S. telecommunications providers are required to install packet sniffing technology to allow Federal law enforcement and intelligence agencies to intercept all of their customers' broadband Internet and VoIP traffic.[d] The large amount of data gathered from packet capture requires surveillance software that filters and reports relevant information, such as the use of certain words or phrases, the access to certain types of web sites, or communicating via email or chat with certain parties. Agencies, such as the Information Awareness Office, NSA, GCHQ and the FBI, spend billions of dollars per year to develop, purchase, implement, and operate systems for interception and analysis of data. Similar systems are operated by Iranian secret police to identify and suppress dissidents. The required hardware and software were allegedly installed by German Siemens AG and Finnish Nokia. Some governments, such as those of Myanmar, Iran, North Korea, Mainland China, Saudi Arabia and the United Arab Emirates, restrict access to content on the Internet within their territories, especially to political and religious content, with domain name and keyword filters. In Norway, Denmark, Finland, and Sweden, major Internet service providers have voluntarily agreed to restrict access to sites listed by authorities. While this list of forbidden resources is supposed to contain only known child pornography sites, the content of the list is secret. Many countries, including the United States, have enacted laws against the possession or distribution of certain material, such as child pornography, via the Internet but do not mandate filter software. Many free or commercially available software programs, called content-control software are available to users to block offensive specific on individual computers or networks in order to limit access by children to pornographic material or depiction of violence.[citation needed] Performance As the Internet is a heterogeneous network, its physical characteristics, including, for example the data transfer rates of connections, vary widely. It exhibits emergent phenomena that depend on its large-scale organization. PB per monthYear020,00040,00060,00080,000100,000120,000140,000199019952000200520102015Petabytes per monthGlobal Internet Traffic Volume The volume of Internet traffic is difficult to measure because no single point of measurement exists in the multi-tiered, non-hierarchical topology. Traffic data may be estimated from the aggregate volume through the peering points of the Tier 1 network providers, but traffic that stays local in large provider networks may not be accounted for.[citation needed] An Internet blackout or outage can be caused by local signaling interruptions. Disruptions of submarine communications cables may cause blackouts or slowdowns to large areas, such as in the 2008 submarine cable disruption. Less-developed countries are more vulnerable due to the small number of high-capacity links. Land cables are also vulnerable, as in 2011 when a woman digging for scrap metal severed most connectivity for the nation of Armenia. Internet blackouts affecting almost entire countries can be achieved by governments as a form of Internet censorship, as in the blockage of the Internet in Egypt, whereby approximately 93% of networks were without access in 2011 in an attempt to stop mobilization for anti-government protests. Estimates of the Internet's electricity usage have been the subject of controversy, according to a 2014 peer-reviewed research paper that found claims differing by a factor of 20,000 published in the literature during the preceding decade, ranging from 0.0064 kilowatt hours per gigabyte transferred (kWh/GB) to 136 kWh/GB. The researchers attributed these discrepancies mainly to the year of reference (i.e. whether efficiency gains over time had been taken into account) and to whether "end devices such as personal computers and servers are included" in the analysis. In 2011, academic researchers estimated the overall energy used by the Internet to be between 170 and 307 GW, less than two percent of the energy used by humanity. This estimate included the energy needed to build, operate, and periodically replace the estimated 750 million laptops, a billion smart phones and 100 million servers worldwide as well as the energy that routers, cell towers, optical switches, Wi-Fi transmitters and cloud storage devices use when transmitting Internet traffic. According to a non-peer-reviewed study published in 2018 by The Shift Project (a French think tank funded by corporate sponsors), nearly 4% of global CO2 emissions could be attributed to global data transfer and the necessary infrastructure. The study also said that online video streaming alone accounted for 60% of this data transfer and therefore contributed to over 300 million tons of CO2 emission per year, and argued for new "digital sobriety" regulations restricting the use and size of video files. See also Notes References Sources Further reading External links |
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Contents Book sources This page allows users to search multiple sources for a book given a 10- or 13-digit International Standard Book Number. Spaces and dashes in the ISBN do not matter. This page links to catalogs of libraries, booksellers, and other book sources where you will be able to search for the book by its International Standard Book Number (ISBN). Online text Google Books and other retail sources below may be helpful if you want to verify citations in Wikipedia articles, because they often let you search an online version of the book for specific words or phrases, or you can browse through the book (although for copyright reasons the entire book is usually not available). At the Open Library (part of the Internet Archive) you can borrow and read entire books online. Online databases Subscription eBook databases Libraries Alabama Alaska California Colorado Connecticut Delaware Florida Georgia Illinois Indiana Iowa Kansas Kentucky Massachusetts Michigan Minnesota Missouri Nebraska New Jersey New Mexico New York North Carolina Ohio Oklahoma Oregon Pennsylvania Rhode Island South Carolina South Dakota Tennessee Texas Utah Washington state Wisconsin Bookselling and swapping Find your book on a site that compiles results from other online sites: These sites allow you to search the catalogs of many individual booksellers: Non-English book sources If the book you are looking for is in a language other than English, you might find it helpful to look at the equivalent pages on other Wikipedias, linked below – they are more likely to have sources appropriate for that language. Find other editions The WorldCat xISBN tool for finding other editions is no longer available. However, there is often a "view all editions" link on the results page from an ISBN search. Google books often lists other editions of a book and related books under the "about this book" link. You can convert between 10 and 13 digit ISBNs with these tools: Find on Wikipedia See also Get free access to research! Research tools and services Outreach Get involved |
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[SOURCE: https://en.wikipedia.org/wiki/Sergey_Brin] | [TOKENS: 2172] |
Contents Sergey Brin Page version status This is an accepted version of this page Sergey Mikhailovich Brin[a] (Russian: Сергей Михайлович Брин; born August 21, 1973) is an American computer scientist and businessman who co-founded Google with Larry Page. He was the president of Google's parent company, Alphabet Inc., until stepping down from the role on December 3, 2019. He and Page remain at Alphabet as co-founders, controlling shareholders, and board members. Brin is a centibillionaire and among the richest people in the world. Brin immigrated to the United States from the Soviet Union at the age of six. He earned his bachelor's degree at the University of Maryland, College Park, following in his father's and grandfather's footsteps by studying mathematics as well as computer science. After graduation, in September 1993, he enrolled in Stanford University to pursue a PhD in computer science. There he met Page, with whom he built a web search engine. The program became popular at Stanford, and he discontinued his PhD studies to start Google in Susan Wojcicki's garage in Menlo Park. In December 2023, he came out of retirement to contribute to AI research at Alphabet Inc.. Early life and education Sergey Mikhailovich Brin was born into a Jewish family on August 21, 1973, in Moscow, the capital of Russia, which was then a constituent republic of the Soviet Union. Both of Brin's parents, Mikhail and Eugenia Brin (1948–2024), had graduated from Moscow State University (MSU). His father is a retired mathematics professor at the University of Maryland, and his mother was a researcher at NASA's Goddard Space Flight Center. The Brin family lived in a three-room apartment in central Moscow, which they also shared with Sergey's paternal grandmother. In 1977, after returning from a mathematics conference in Warsaw, Poland, Mikhail announced that, because of antisemitism in the Soviet Union, it was time for the family to emigrate. They formally applied for their exit visa in September 1978, and as a result, his father was "promptly fired". For related reasons, his mother had to leave her job. For the next eight months, without any steady income, they were forced to take on temporary jobs as they waited, afraid their request would be denied as it was for many refuseniks. In May 1979, they were granted their official exit visas and were allowed to leave the country. The Brin family lived in Vienna and Paris while Mikhail Brin secured a teaching position at the University of Maryland with help from Anatole Katok. During this time, the Brin family received support and assistance from the Hebrew Immigrant Aid Society. They arrived in the United States on October 25, 1979. He attended Eleanor Roosevelt High School. In September 1990, Brin enrolled in the University of Maryland, where he received his Bachelor of Science from the Department of Computer Science in 1993 with honors in computer science and high honors in mathematics at the age of 19. In 1993, he interned at Wolfram Research, the developers of Mathematica. Brin began his graduate study in computer science at Stanford University on a graduate fellowship from the National Science Foundation, receiving a Master of Science degree in computer science in 1995. As of 2008[update], he was on leave from his Doctor of Philosophy studies at Stanford. Search engine development During an orientation for new students at Stanford, he met Larry Page. The two men seemed to disagree on most subjects, but after spending time together they "became intellectual soul-mates and close friends." Brin's focus was on developing data mining systems while Page's was on extending "the concept of inferring the importance of a research paper from its citations in other papers". Together, they authored a paper titled "The Anatomy of a Large-Scale Hypertextual Web Search Engine". To convert the backlink data gathered by Backrub's web crawler into a measure of importance for a given web page, Brin and Page developed the PageRank algorithm, and realized that it could be used to build a search engine far superior to those existing at the time. The new algorithm relied on a new kind of technology that analyzed the relevance of the backlinks that connected one Web page to another, and allowed the number of links and their rank, to determine the rank of the page. Combining their ideas, they began utilizing Page's dormitory room as a machine laboratory, and extracted spare parts from inexpensive computers to create a device that they used to connect the nascent search engine with Stanford's broadband campus network. After filling Page's room with equipment, they then converted Brin's dorm room into an office and programming center, where they tested their new search engine designs on the web. The rapid growth of their project caused Stanford's computing infrastructure to experience problems. Page and Brin used Page's basic HTML programming skills to set up a simple search page for users, as they did not have a web page developer to create anything visually elaborate. They also began using any computer part they could find to assemble the necessary computing power to handle searches by multiple users. As their search engine grew in popularity among Stanford users, it required additional servers to process the queries. In August 1996, the initial version of Google was made available on the Stanford Web site. By early 1997, the Backrub page described the state as follows: BackRub already exhibited the rudimentary functions and characteristics of a search engine: a query input was entered and it provided a list of backlinks ranked by importance. Page recalled: "We realized that we had a querying tool. It gave you a good overall ranking of pages and ordering of follow-up pages." Page said that in mid-1998 they finally realized the further potential of their project: "Pretty soon, we had 10,000 searches a day. And we figured, maybe this is really real." Some compared Page and Brin's vision to the impact of Johannes Gutenberg, the inventor of modern printing: In 1440, Johannes Gutenberg introduced Europe to the mechanical printing press, printing Bibles for mass consumption. The technology allowed for books and manuscripts—originally replicated by hand—to be printed at a much faster rate, thus spreading knowledge and helping to usher in the European Renaissance ... Google has done a similar job. The comparison was also noted by the authors of The Google Story: "Not since Gutenberg ... has any new invention empowered individuals, and transformed access to information, as profoundly as Google." Also, not long after the two "cooked up their new engine for web searches, they began thinking about information that was at the time beyond the web," such as digitizing books and expanding health information. Other interests In June 2008, Brin invested $4.5 million in Space Adventures, a Virginia-based space tourism company. Brin and Page jointly own a customized Boeing 767–200 and a Dassault/Dornier Alpha Jet, and pay $1.3 million a year to house them and two Gulfstream V jets owned by Google executives at Moffett Federal Airfield. The aircraft has scientific equipment installed by NASA to allow experimental data to be collected in flight. Brin is a backer of LTA Research & Exploration LLC, an airship maker company. In October 2023, LTA's 124-meter long flagship, Pathfinder 1, became the largest airship since the Hindenburg to receive clearance for flight testing, permitted over the boundaries of Moffett Field and neighboring Palo Alto Airport's airspaces, at a height of up to 460 meters. Personal life Brin was raised Jewish, but is not religious.[better source needed] In May 2007, Brin married biotech analyst and entrepreneur Anne Wojcicki in the Bahamas. They had a son in late 2008 and a daughter in late 2011. In August 2013, it was announced that Brin and his wife were living separately after Brin had an extramarital affair with a Google Glass colleague. In June 2015, Brin and Wojcicki finalized their divorce. On November 7, 2018, he married Nicole Shanahan, a legal tech founder. They have a daughter, born in late 2018. Brin and Shanahan separated on December 15, 2021, and Brin filed for divorce on January 4, 2022. In summer 2023, the divorce was finalized. The Wall Street Journal reported that a reason for the breakup was a "brief affair" in 2021 between Shanahan and Elon Musk. Brin's mother, Eugenia, has been diagnosed with Parkinson's disease. In 2008, he decided to make a donation to the University of Maryland School of Medicine, where his mother has received treatment. According to Forbes, Brin has donated over $1 billion to fund research on the disease. Brin and Wojcicki, although separated, jointly ran The Brin Wojcicki Foundation until 2014. Since then, Brin has used the Sergey Brin Family Foundation and a donor-advised fund for his philanthropic giving. They donated extensively to The Michael J. Fox Foundation and in 2009 gave $1 million to support the Hebrew Immigrant Aid Society. Brin is a donor to Democratic Party candidates and organizations, having donated $5,000 to Barack Obama's 2012 reelection campaign and $30,800 to the DNC. Brin attended the second inauguration of Donald Trump, sitting alongside Donald Trump supporters and other tech moguls. In December 2025, Brin and Page, worth a combined $520 billion, terminated or moved out of California 60 limited liability companies that hold their assets. Brin is the owner of the superyacht Dragonfly. Awards and accolades he was a featured speaker at the World Economic Forum and the Technology, Entertainment and Design Conference. ... PC Magazine has praised Google in the Top 100 Web Sites and Search Engines (1998) and awarded Google the Technical Excellence Award, for Innovation in Web Application Development in 1999. In 2000, Google earned a Webby Award, a People's Voice Award for technical achievement, and in 2001, was awarded Outstanding Search Service, Best Image Search Engine, Best Design, Most Webmaster Friendly Search Engine, and Best Search Feature at the Search Engine Watch Awards. Appearances in film Notes and references Notes References External links |
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Contents Account verification Account verification is the process of verifying that a new or existing account is owned and operated by a specified real individual or organization. A number of websites, for example social media websites, offer account verification services. Verified accounts are often visually distinguished by check mark icons or badges next to the names of individuals or organizations. Account verification can enhance the quality of online services, mitigating sockpuppetry, bots, trolling, spam, vandalism, fake news, disinformation and election interference. History Account verification was introduced by Twitter in June 2009, initially as a feature for public figures and accounts of interest, individuals in "music, acting, fashion, government, politics, religion, journalism, media, sports, business and other key interest areas". A similar verification system was adopted by Google+ in 2011, Facebook page in October 2015 (Available in United States, Canada, United Kingdom, Australia and New Zealand) Facebook profile and Facebook page in 2018 (Available in Worldwide) Instagram in 2014, and Pinterest in 2015. On YouTube, users are able to submit a request for a verification badge once they obtain 100,000 or more subscribers. It also has an "official artist" badge for musicians and bands. In July 2016, Twitter announced that, beyond public figures, any individual would be able to apply for account verification. This was temporarily suspended in February 2018, following a backlash over the verification of one of the organisers of the far-right Unite the Right rally due to a perception that verification conveys "credibility" or "importance". In March 2018, during a live-stream on Periscope, Jack Dorsey, co-founder and CEO of Twitter, discussed the idea of allowing any individual to get a verified account. Twitter reopened account verification applications in May 2021 after revamping their account verification criteria. This time offering notability criteria for the account categories of government, companies, brands, and organizations, news organizations and journalists, entertainment, sports and activists, organizers, and other influential individuals. Instagram began allowing users to request verification in August 2018. In April 2018, Mark Zuckerberg, co-founder and CEO of Facebook, announced that purchasers of political or issue-based advertisements would be required to verify their identities and locations. He also indicated that Facebook would require individuals who manage large pages to be verified. In May 2018, Kent Walker, senior vice president of Google, announced that, in the United States, purchasers of political-leaning advertisements would need to verify their identities. In November 2022, Elon Musk included a blue verification check mark with a paid Twitter Blue monthly membership. Prior to Musk's acquisition of Twitter, Twitter offered this check mark at no charge to confirmed high profile users. On December 19, 2022, Twitter introduced two new check mark colors: gold for accounts from official businesses and organizations, and grey for accounts from governments or multilateral organizations. The type of check mark can be confirmed by visiting the profile page, then clicking or tapping on the check mark. Techniques Identity verification services are third-party solutions which can be used to ensure that a person provides information which is associated with the identity of a real person. Such services may verify the authenticity of identity documents such as drivers licenses or passports, called documentary verification, or may verify identity information against authoritative sources such as credit bureaus or government data, called nondocumentary verification.[citation needed] The uploading of scanned or photographed identity documents is a practice in use, for example, at Facebook. According to Facebook, there are two reasons that a person would be asked to send a scan of or photograph of an ID to Facebook: to show account ownership and to confirm their name. In January 2018, Facebook purchased Confirm.io, a startup that was advancing technologies to verify the authenticity of identification documentation. Behavioral verification is the computer-aided and automated detection and analysis of behaviors and patterns of behavior to verify accounts. Behaviors to detect include those of sockpuppets, bots, cyborgs, trolls, spammers, vandals, and sources and spreaders of fake news, disinformation and election interference. Behavioral verification processes can flag accounts as suspicious, exclude accounts from suspicion, or offer corroborating evidence for processes of account verification. Identity verification is required to establish bank accounts and other financial accounts in many jurisdictions. Verifying identity in the financial sector is often required by regulation such as Know Your Customer or Customer Identification Program. Accordingly, bank accounts can be of use as corroborating evidence when performing account verification. Bank account information can be provided when creating or verifying an account or when making a purchase. Postal address information can be provided when creating or verifying an account or when making and subsequently shipping a purchase. A hyperlink or code can be sent to a user by mail, recipients entering it on a website verifying their postal address. A telephone number can be provided when creating or verifying an account or added to an account to obtain a set of features. During the process of verifying a telephone number, a confirmation code is sent to a phone number specified by a user, for example in an SMS message sent to a mobile phone. As the user receives the code sent, they can enter it on the website to confirm their receipt. An email account is often required to create an account. During this process, a confirmation hyperlink is sent in an email message to an email address specified by a person. The email recipient is instructed in the email message to navigate to the provided confirmation hyperlink if and only if they are the person creating an account. The act of navigating to the hyperlink confirms receipt of the email by the person. The added value of an email account for purposes of account verification depends upon the process of account verification performed by the specific email service provider. Multi-factor account verification is account verification which simultaneously utilizes a number of techniques. The processes of account verification utilized by multiple service providers can corroborate one another. OpenID Connect includes a user information protocol which can be used to link multiple accounts, corroborating user information. Account verification and good standing On some services, account verification is synonymous with good standing. Twitter reserves the right to remove account verification from users' accounts at any time without notice. Reasons for removal may reflect behaviors on and off Twitter and include: promoting hate and/or violence against, or directly attacking or threatening other people on the basis of race, ethnicity, national origin, sexual orientation, gender, gender identity, religious affiliation, age, disability, or disease; supporting organizations or individuals that promote the above; inciting or engaging in the harassment of others; violence and dangerous behavior; directly or indirectly threatening or encouraging any form of physical violence against an individual or any group of people, including threatening or promoting terrorism; violent, gruesome, shocking, or disturbing imagery; self-harm, suicide; and engaging in other activity on Twitter that violates the Twitter Rules. In April 2023, Blue ticks were removed from all Twitter accounts that had not subscribed to Twitter Blue. See also References |
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[SOURCE: https://en.wikipedia.org/wiki/Jews#cite_note-NollMerneptah-113] | [TOKENS: 15852] |
Contents Jews Jews (Hebrew: יְהוּדִים, ISO 259-2: Yehudim, Israeli pronunciation: [jehuˈdim]), or the Jewish people, are an ethnoreligious group and nation, originating from the Israelites of ancient Israel and Judah. They traditionally adhere to Judaism. Jewish ethnicity, religion, and community are highly interrelated, as Judaism is an ethnic religion, though many ethnic Jews do not practice it. Religious Jews regard converts to Judaism as members of the Jewish nation, pursuant to the long-standing conversion process. The Israelites emerged from the pre-existing Canaanite peoples to establish Israel and Judah in the Southern Levant during the Iron Age. Originally, Jews referred to the inhabitants of the kingdom of Judah and were distinguished from the gentiles and the Samaritans. According to the Hebrew Bible, these inhabitants predominately originate from the tribe of Judah, who were descendants of Judah, the fourth son of Jacob. The tribe of Benjamin were another significant demographic in Judah and were considered Jews too. By the late 6th century BCE, Judaism had evolved from the Israelite religion, dubbed Yahwism (for Yahweh) by modern scholars, having a theology that religious Jews believe to be the expression of the Mosaic covenant between God and the Jewish people. After the Babylonian exile, Jews referred to followers of Judaism, descendants of the Israelites, citizens of Judea, or allies of the Judean state. Jewish migration within the Mediterranean region during the Hellenistic period, followed by population transfers, caused by events like the Jewish–Roman wars, gave rise to the Jewish diaspora, consisting of diverse Jewish communities that maintained their sense of Jewish history, identity, and culture. In the following millennia, Jewish diaspora communities coalesced into three major ethnic subdivisions according to where their ancestors settled: the Ashkenazim (Central and Eastern Europe), the Sephardim (Iberian Peninsula), and the Mizrahim (Middle East and North Africa). While these three major divisions account for most of the world's Jews, there are other smaller Jewish groups outside of the three. Prior to World War II, the global Jewish population reached a peak of 16.7 million, representing around 0.7% of the world's population at that time. During World War II, approximately six million Jews throughout Europe were systematically murdered by Nazi Germany in a genocide known as the Holocaust. Since then, the population has slowly risen again, and as of 2021[update], was estimated to be at 15.2 million by the demographer Sergio Della Pergola or less than 0.2% of the total world population in 2012.[b] Today, over 85% of Jews live in Israel or the United States. Israel, whose population is 73.9% Jewish, is the only country where Jews comprise more than 2.5% of the population. Jews have significantly influenced and contributed to the development and growth of human progress in many fields, both historically and in modern times, including in science and technology, philosophy, ethics, literature, governance, business, art, music, comedy, theatre, cinema, architecture, food, medicine, and religion. Jews founded Christianity and had an indirect but profound influence on Islam. In these ways and others, Jews have played a significant role in the development of Western culture. Name and etymology The term "Jew" is derived from the Hebrew word יְהוּדִי Yehudi, with the plural יְהוּדִים Yehudim. Endonyms in other Jewish languages include the Ladino ג׳ודיו Djudio (plural ג׳ודיוס, Djudios) and the Yiddish ייִד Yid (plural ייִדן Yidn). Though Genesis 29:35 and 49:8 connect "Judah" with the verb yada, meaning "praise", scholars generally agree that "Judah" most likely derives from the name of a Levantine geographic region dominated by gorges and ravines. The gradual ethnonymic shift from "Israelites" to "Jews", regardless of their descent from Judah, although not contained in the Torah, is made explicit in the Book of Esther (4th century BCE) of the Tanakh. Some modern scholars disagree with the conflation, based on the works of Josephus, Philo and Apostle Paul. The English word "Jew" is a derivation of Middle English Gyw, Iewe. The latter was loaned from the Old French giu, which itself evolved from the earlier juieu, which in turn derived from judieu/iudieu which through elision had dropped the letter "d" from the Medieval Latin Iudaeus, which, like the New Testament Greek term Ioudaios, meant both "Jew" and "Judean" / "of Judea". The Greek term was a loan from Aramaic *yahūdāy, corresponding to Hebrew יְהוּדִי Yehudi. Some scholars prefer translating Ioudaios as "Judean" in the Bible since it is more precise, denotes the community's origins and prevents readers from engaging in antisemitic eisegesis. Others disagree, believing that it erases the Jewish identity of Biblical characters such as Jesus. Daniel R. Schwartz distinguishes "Judean" and "Jew". Here, "Judean" refers to the inhabitants of Judea, which encompassed southern Palestine. Meanwhile, "Jew" refers to the descendants of Israelites that adhere to Judaism. Converts are included in the definition. But Shaye J.D. Cohen argues that "Judean" is inclusive of believers of the Judean God and allies of the Judean state. Another scholar, Jodi Magness, wrote the term Ioudaioi refers to a "people of Judahite/Judean ancestry who worshipped the God of Israel as their national deity and (at least nominally) lived according to his laws." The etymological equivalent is in use in other languages, e.g., يَهُودِيّ yahūdī (sg.), al-yahūd (pl.), in Arabic, "Jude" in German, "judeu" in Portuguese, "Juif" (m.)/"Juive" (f.) in French, "jøde" in Danish and Norwegian, "judío/a" in Spanish, "jood" in Dutch, "żyd" in Polish etc., but derivations of the word "Hebrew" are also in use to describe a Jew, e.g., in Italian (Ebreo), in Persian ("Ebri/Ebrani" (Persian: عبری/عبرانی)) and Russian (Еврей, Yevrey). The German word "Jude" is pronounced [ˈjuːdə], the corresponding adjective "jüdisch" [ˈjyːdɪʃ] (Jewish) is the origin of the word "Yiddish". According to The American Heritage Dictionary of the English Language, fourth edition (2000), It is widely recognized that the attributive use of the noun Jew, in phrases such as Jew lawyer or Jew ethics, is both vulgar and highly offensive. In such contexts Jewish is the only acceptable possibility. Some people, however, have become so wary of this construction that they have extended the stigma to any use of Jew as a noun, a practice that carries risks of its own. In a sentence such as There are now several Jews on the council, which is unobjectionable, the substitution of a circumlocution like Jewish people or persons of Jewish background may in itself cause offense for seeming to imply that Jew has a negative connotation when used as a noun. Identity Judaism shares some of the characteristics of a nation, an ethnicity, a religion, and a culture, making the definition of who is a Jew vary slightly depending on whether a religious or national approach to identity is used.[better source needed] Generally, in modern secular usage, Jews include three groups: people who were born to a Jewish family regardless of whether or not they follow the religion, those who have some Jewish ancestral background or lineage (sometimes including those who do not have strictly matrilineal descent), and people without any Jewish ancestral background or lineage who have formally converted to Judaism and therefore are followers of the religion. In the context of biblical and classical literature, Jews could refer to inhabitants of the Kingdom of Judah, or the broader Judean region, allies of the Judean state, or anyone that followed Judaism. Historical definitions of Jewish identity have traditionally been based on halakhic definitions of matrilineal descent, and halakhic conversions. These definitions of who is a Jew date back to the codification of the Oral Torah into the Babylonian Talmud, around 200 CE. Interpretations by Jewish sages of sections of the Tanakh – such as Deuteronomy 7:1–5, which forbade intermarriage between their Israelite ancestors and seven non-Israelite nations: "for that [i.e. giving your daughters to their sons or taking their daughters for your sons,] would turn away your children from following me, to serve other gods"[failed verification] – are used as a warning against intermarriage between Jews and gentiles. Leviticus 24:10 says that the son in a marriage between a Hebrew woman and an Egyptian man is "of the community of Israel." This is complemented by Ezra 10:2–3, where Israelites returning from Babylon vow to put aside their gentile wives and their children. A popular theory is that the rape of Jewish women in captivity brought about the law of Jewish identity being inherited through the maternal line, although scholars challenge this theory citing the Talmudic establishment of the law from the pre-exile period. Another argument is that the rabbis changed the law of patrilineal descent to matrilineal descent due to the widespread rape of Jewish women by Roman soldiers. Since the anti-religious Haskalah movement of the late 18th and 19th centuries, halakhic interpretations of Jewish identity have been challenged. According to historian Shaye J. D. Cohen, the status of the offspring of mixed marriages was determined patrilineally in the Bible. He brings two likely explanations for the change in Mishnaic times: first, the Mishnah may have been applying the same logic to mixed marriages as it had applied to other mixtures (Kil'ayim). Thus, a mixed marriage is forbidden as is the union of a horse and a donkey, and in both unions the offspring are judged matrilineally. Second, the Tannaim may have been influenced by Roman law, which dictated that when a parent could not contract a legal marriage, offspring would follow the mother. Rabbi Rivon Krygier follows a similar reasoning, arguing that Jewish descent had formerly passed through the patrilineal descent and the law of matrilineal descent had its roots in the Roman legal system. Origins The prehistory and ethnogenesis of the Jews are closely intertwined with archaeology, biology, historical textual records, mythology, and religious literature. The ethnic origin of the Jews lie in the Israelites, a confederation of Iron Age Semitic-speaking tribes that inhabited a part of Canaan during the tribal and monarchic periods. Modern Jews are named after and also descended from the southern Israelite Kingdom of Judah. Gary A. Rendsburg links the early Canaanite nomadic pastoralists confederation to the Shasu known to the Egyptians around the 15th century BCE. According to the Hebrew Bible narrative, Jewish history begins with the Biblical patriarchs such as Abraham, his son Isaac, Isaac's son Jacob, and the Biblical matriarchs Sarah, Rebecca, Leah, and Rachel, who lived in Canaan. The twelve sons of Jacob subsequently gave birth to the Twelve Tribes. Jacob and his family migrated to Ancient Egypt after being invited to live with Jacob's son Joseph by the Pharaoh himself. Jacob's descendants were later enslaved until the Exodus, led by Moses. Afterwards, the Israelites conquered Canaan under Moses' successor Joshua, and went through the period of the Biblical judges after the death of Joshua. Through the mediation of Samuel, the Israelites were subject to a king, Saul, who was succeeded by David and then Solomon, after whom the United Monarchy ended and was split into a separate Kingdom of Israel and a Kingdom of Judah. The Kingdom of Judah is described as comprising the tribes of Judah, Benjamin and partially, Levi. They later assimilated remnants of other tribes who migrated there from the northern Kingdom of Israel. In the extra-biblical record, the Israelites become visible as a people between 1200 and 1000 BCE. There is well accepted archeological evidence referring to "Israel" in the Merneptah Stele, which dates to about 1200 BCE, and in the Mesha stele from 840 BCE. It is debated whether a period like that of the Biblical judges occurred and if there ever was a United Monarchy. There is further disagreement about the earliest existence of the Kingdoms of Israel and Judah and their extent and power. Historians agree that a Kingdom of Israel existed by c. 900 BCE,: 169–95 there is a consensus that a Kingdom of Judah existed by c. 700 BCE at least, and recent excavations in Khirbet Qeiyafa have provided strong evidence for dating the Kingdom of Judah to the 10th century BCE. In 587 BCE, Nebuchadnezzar II, King of the Neo-Babylonian Empire, besieged Jerusalem, destroyed the First Temple and deported parts of the Judahite population. Scholars disagree regarding the extent to which the Bible should be accepted as a historical source for early Israelite history. Rendsburg states that there are two approximately equal groups of scholars who debate the historicity of the biblical narrative, the minimalists who largely reject it, and the maximalists who largely accept it, with the minimalists being the more vocal of the two. Some of the leading minimalists reframe the biblical account as constituting the Israelites' inspiring national myth narrative, suggesting that according to the modern archaeological and historical account, the Israelites and their culture did not overtake the region by force, but instead branched out of the Canaanite peoples and culture through the development of a distinct monolatristic—and later monotheistic—religion of Yahwism centered on Yahweh, one of the gods of the Canaanite pantheon. The growth of Yahweh-centric belief, along with a number of cultic practices, gradually gave rise to a distinct Israelite ethnic group, setting them apart from other Canaanites. According to Dever, modern archaeologists have largely discarded the search for evidence of the biblical narrative surrounding the patriarchs and the exodus. According to the maximalist position, the modern archaeological record independently points to a narrative which largely agrees with the biblical account. This narrative provides a testimony of the Israelites as a nomadic people known to the Egyptians as belonging to the Shasu. Over time these nomads left the desert and settled on the central mountain range of the land of Canaan, in simple semi-nomadic settlements in which pig bones are notably absent. This population gradually shifted from a tribal lifestyle to a monarchy. While the archaeological record of the ninth century BCE provides evidence for two monarchies, one in the south under a dynasty founded by a figure named David with its capital in Jerusalem, and one in the north under a dynasty founded by a figure named Omri with its capital in Samaria. It also points to an early monarchic period in which these regions shared material culture and religion, suggesting a common origin. Archaeological finds also provide evidence for the later cooperation of these two kingdoms in their coalition against Aram, and for their destructions by the Assyrians and later by the Babylonians. Genetic studies on Jews show that most Jews worldwide bear a common genetic heritage which originates in the Middle East, and that they share certain genetic traits with other Gentile peoples of the Fertile Crescent. The genetic composition of different Jewish groups shows that Jews share a common gene pool dating back four millennia, as a marker of their common ancestral origin. Despite their long-term separation, Jewish communities maintained their unique commonalities, propensities, and sensibilities in culture, tradition, and language. History The earliest recorded evidence of a people by the name of Israel appears in the Merneptah Stele, which dates to around 1200 BCE. The majority of scholars agree that this text refers to the Israelites, a group that inhabited the central highlands of Canaan, where archaeological evidence shows that hundreds of small settlements were constructed between the 12th and 10th centuries BCE. The Israelites differentiated themselves from neighboring peoples through various distinct characteristics including religious practices, prohibition on intermarriage, and an emphasis on genealogy and family history. In the 10th century BCE, two neighboring Israelite kingdoms—the northern Kingdom of Israel and the southern Kingdom of Judah—emerged. Since their inception, they shared ethnic, cultural, linguistic and religious characteristics despite a complicated relationship. Israel, with its capital mostly in Samaria, was larger and wealthier, and soon developed into a regional power. In contrast, Judah, with its capital in Jerusalem, was less prosperous and covered a smaller, mostly mountainous territory. However, while in Israel the royal succession was often decided by a military coup d'état, resulting in several dynasty changes, political stability in Judah was much greater, as it was ruled by the House of David for the whole four centuries of its existence. Scholars also describe Biblical Jews as a 'proto-nation', in the modern nationalist sense, comparable to classical Greeks, the Gauls and the British Celts. Around 720 BCE, Kingdom of Israel was destroyed when it was conquered by the Neo-Assyrian Empire, which came to dominate the ancient Near East. Under the Assyrian resettlement policy, a significant portion of the northern Israelite population was exiled to Mesopotamia and replaced by immigrants from the same region. During the same period, and throughout the 7th century BCE, the Kingdom of Judah, now under Assyrian vassalage, experienced a period of prosperity and witnessed a significant population growth. This prosperity continued until the Neo-Assyrian king Sennacherib devastated the region of Judah in response to a rebellion in the area, ultimately halting at Jerusalem. Later in the same century, the Assyrians were defeated by the rising Neo-Babylonian Empire, and Judah became its vassal. In 587 BCE, following a revolt in Judah, the Babylonian king Nebuchadnezzar II besieged and destroyed Jerusalem and the First Temple, putting an end to the kingdom. The majority of Jerusalem's residents, including the kingdom's elite, were exiled to Babylon. According to the Book of Ezra, the Persian Cyrus the Great ended the Babylonian exile in 538 BCE, the year after he captured Babylon. The exile ended with the return under Zerubbabel the Prince (so called because he was a descendant of the royal line of David) and Joshua the Priest (a descendant of the line of the former High Priests of the Temple) and their construction of the Second Temple circa 521–516 BCE. As part of the Persian Empire, the former Kingdom of Judah became the province of Judah (Yehud Medinata), with a smaller territory and a reduced population. Judea was under control of the Achaemenids until the fall of their empire in c. 333 BCE to Alexander the Great. After several centuries under foreign imperial rule, the Maccabean Revolt against the Seleucid Empire resulted in an independent Hasmonean kingdom, under which the Jews once again enjoyed political independence for a period spanning from 110 to 63 BCE. Under Hasmonean rule the boundaries of their kingdom were expanded to include not only the land of the historical kingdom of Judah, but also the Galilee and Transjordan. In the beginning of this process the Idumeans, who had infiltrated southern Judea after the destruction of the First Temple, were converted en masse. In 63 BCE, Judea was conquered by the Romans. From 37 BCE to 6 CE, the Romans allowed the Jews to maintain some degree of independence by installing the Herodian dynasty as vassal kings. However, Judea eventually came directly under Roman control and was incorporated into the Roman Empire as the province of Judaea. The Jewish–Roman wars, a series of failed uprisings against Roman rule during the first and second centuries CE, had profound and devastating consequences for the Jewish population of Judaea. The First Jewish–Roman War (66–73/74 CE) culminated in the destruction of Jerusalem and the Second Temple, after which the significantly diminished Jewish population was stripped of political autonomy. A few generations later, the Bar Kokhba revolt (132–136 CE) erupted in response to Roman plans to rebuild Jerusalem as a Roman colony, and, possibly, to restrictions on circumcision. Its violent suppression by the Romans led to the near-total depopulation of Judea, and the demographic and cultural center of Jewish life shifted to Galilee. Jews were subsequently banned from residing in Jerusalem and the surrounding area, and the province of Judaea was renamed Syria Palaestina. These developments effectively ended Jewish efforts to restore political sovereignty in the region for nearly two millennia. Similar upheavals impacted the Jewish communities in the empire's eastern provinces during the Diaspora Revolt (115–117 CE), leading to the near-total destruction of Jewish diaspora communities in Libya, Cyprus and Egypt, including the highly influential community in Alexandria. The destruction of the Second Temple in 70 CE brought profound changes to Judaism. With the Temple's central place in Jewish worship gone, religious practices shifted towards prayer, Torah study (including Oral Torah), and communal gatherings in synagogues. Judaism also lost much of its sectarian nature.: 69 Two of the three main sects that flourished during the late Second Temple period, namely the Sadducees and Essenes, eventually disappeared, while Pharisaic beliefs became the foundational, liturgical, and ritualistic basis of Rabbinic Judaism, which emerged as the prevailing form of Judaism since late antiquity. The Jewish diaspora existed well before the destruction of the Second Temple in 70 CE and had been ongoing for centuries, with the dispersal driven by both forced expulsions and voluntary migrations. In Mesopotamia, a testimony to the beginnings of the Jewish community can be found in Joachin's ration tablets, listing provisions allotted to the exiled Judean king and his family by Nebuchadnezzar II, and further evidence are the Al-Yahudu tablets, dated to the 6th–5th centuries BCE and related to the exiles from Judea arriving after the destruction of the First Temple, though there is ample evidence for the presence of Jews in Babylonia even from 626 BCE. In Egypt, the documents from Elephantine reveal the trials of a community founded by a Persian Jewish garrison at two fortresses on the frontier during the 5th–4th centuries BCE, and according to Josephus the Jewish community in Alexandria existed since the founding of the city in the 4th century BCE by Alexander the Great. By 200 BCE, there were well established Jewish communities both in Egypt and Mesopotamia ("Babylonia" in Jewish sources) and in the two centuries that followed, Jewish populations were also present in Asia Minor, Greece, Macedonia, Cyrene, and, beginning in the middle of the first century BCE, in the city of Rome. Later, in the first centuries CE, as a result of the Jewish-Roman Wars, a large number of Jews were taken as captives, sold into slavery, or compelled to flee from the regions affected by the wars, contributing to the formation and expansion of Jewish communities across the Roman Empire as well as in Arabia and Mesopotamia. After the Bar Kokhba revolt, the Jewish population in Judaea—now significantly reduced— made efforts to recover from the revolt's devastating effects, but never fully regained its former strength. Between the second and fourth centuries CE, the region of Galilee emerged as the primary center of Jewish life in Syria Palaestina, experiencing both demographic growth and cultural development. It was during this period that two central rabbinic texts, the Mishnah and the Jerusalem Talmud, were composed. The Romans recognized the patriarchs—rabbinic sages such as Judah ha-Nasi—as representatives of the Jewish people, granting them a certain degree of autonomy. However, as the Roman Empire gave way to the Christianized Byzantine Empire under Constantine, Jews began to face persecution by both the Church and imperial authorities, Jews came to be persecuted by the church and the authorities, and many immigrated to communities in the diaspora. By the fourth century CE, Jews are believed to have lost their demographic majority in Syria Palaestina. The long-established Jewish community of Mesopotamia, which had been living under Parthian and later Sasanian rule, beyond the confines of the Roman Empire, became an important center of Jewish study as Judea's Jewish population declined. Estimates often place the Babylonian Jewish community of the 3rd to 7th centuries at around one million, making it the largest Jewish diaspora community of that period. Under the political leadership of the exilarch, who was regarded as a royal heir of the House of David, this community had an autonomous status and served as a place of refuge for the Jews of Syria Palaestina. A number of significant Talmudic academies, such as the Nehardea, Pumbedita, and Sura academies, were established in Mesopotamia, and many important Amoraim were active there. The Babylonian Talmud, a centerpiece of Jewish religious law, was compiled in Babylonia in the 3rd to 6th centuries. Jewish diaspora communities are generally described to have coalesced into three major ethnic subdivisions according to where their ancestors settled: the Ashkenazim (initially in the Rhineland and France), the Sephardim (initially in the Iberian Peninsula), and the Mizrahim (Middle East and North Africa). Romaniote Jews, Tunisian Jews, Yemenite Jews, Egyptian Jews, Ethiopian Jews, Bukharan Jews, Mountain Jews, and other groups also predated the arrival of the Sephardic diaspora. During the same period, Jewish communities in the Middle East thrived under Islamic rule, especially in cities like Baghdad, Cairo, and Damascus. In Babylonia, from the 7th to 11th centuries the Pumbedita and Sura academies led the Arab and to an extent the entire Jewish world. The deans and students of said academies defined the Geonic period in Jewish history. Following this period were the Rishonim who lived from the 11th to 15th centuries. Like their European counterparts, Jews in the Middle East and North Africa also faced periods of persecution and discriminatory policies, with the Almohad Caliphate in North Africa and Iberia issuing forced conversion decrees, causing Jews such as Maimonides to seek safety in other regions. Despite experiencing repeated waves of persecution, Ashkenazi Jews in Western Europe worked in a variety of fields, making an impact on their communities' economy and societies. In Francia, for example, figures like Isaac Judaeus and Armentarius occupied prominent social and economic positions. Francia also witnessed the development of a sophisticated tradition of biblical commentary, as exemplified by Rashi and the tosafists. In 1144, the first documented blood libel occurred in Norwich, England, marking an escalation in the pattern of discrimination and violence that Jews had already been subjected to throughout medieval Europe. During the 12th and 13th centuries, Jews faced frequent antisemitic legislation - including laws prescribing distinctive dress - alongside segregation, repeated blood libels, pogroms, and massacres such as the Rhineland Massacres (1066). The Jews of the Holy Roman Empire were designated Servi camerae regis (“servants of the imperial chamber”) by Frederick II, a status that afforded limited protection while simultaneously entangling them in the political struggles between the emperor and the German principalities and cities. Persecution intensified during the Black Death in the mid-14th century, when Jews were accused of poisoning wells and many communities were destroyed. These pressures, combined with major expulsions such as that from England in 1290, gradually pushed Ashkenazi Jewish populations eastward into Poland, Lithuania, and Russia. One of the largest Jewish communities of the Middle Ages was in the Iberian Peninsula, which for a time contained the largest Jewish population in Europe. Iberian Jewry endured discrimination under the Visigoths but saw its fortunes improve under Umayyad rule and later the Taifa kingdoms. During this period, the Jews of Muslim Spain entered a "Golden Age" marked by achievements in Hebrew poetry and literature, religious scholarship, grammar, medicine and science, with leading figures including Hasdai ibn Shaprut, Judah Halevi, Moses ibn Ezra and Solomon ibn Gabirol. Jews also rose to high office, most notably Samuel ibn Naghrillah, a scholar and poet who served as grand vizier and military commander of Granada. The Golden Age ended with the rise of the radical Almoravid and Almohad dynasties, whose persecutions drove many Jews from Iberia (including Maimonides), together with the advancing Reconquista. In 1391, widespread pogroms swept across Spain, leaving thousands dead and forcing mass conversions. The Spanish Inquisition was later established to pursue, torture and execute conversos who continued to practice Judaism in secret, while public disputations were staged to discredit Judaism. In 1492, after the Reconquista, Isabella I of Castile and Ferdinand II of Aragon decreed the expulsion of all Jews who refused conversion, sending an estimated 200,000 into exile in Portugal, Italy, North Africa, and the Ottoman Empire. In 1497, Portugal's Jews, about 30,000, were formally ordered expelled but instead were forcibly converted to retain their economic role. In 1498, some 3,500 Jews were expelled from Navarre. Many converts outwardly adopted Christianity while secretly preserving Jewish practices, becoming crypto-Jews (also known as marranos or anusim), who remained targets of the various Inquisitions for centuries. Following the expulsions from Spain and Portugal in the 1490s, Jewish exiles dispersed across the Mediterranean, Europe, and North Africa. Many settled in the Ottoman Empire—which, replacing the Iberian Peninsula, became home to the world's largest Jewish population—where new communities developed in Anatolia, the Balkans, and the Land of Israel. Cities such as Istanbul and Thessaloniki grew into major Jewish centers, while in 16th-century Safed a flourishing spiritual life took shape. There, Solomon Alkabetz, Moses Cordovero, and Isaac Luria developed influential new schools of Kabbalah, giving powerful impetus to Jewish mysticism, and Joseph Karo composed the Shulchan Aruch, which became a cornerstone of Jewish law. In the 17th century, Portuguese conversos who returned to Judaism and engaged in trade and banking helped establish Amsterdam as a prosperous Jewish center, while also forming communities in cities such as Antwerp and London. This period also witnessed waves of messianic fervor, most notably the rise of the Sabbatean movement in the 1660s, led by Sabbatai Zvi of İzmir, which reverberated throughout the Jewish world. In Eastern Europe, Poland–Lithuania became the principal center of Ashkenazi Jewry, eventually becoming home to the largest Jewish population in the world. Jewish life flourished there from in the early modern era, supported by relative stability, economic opportunity, and strong communal institutions. The mid-17th century brought devastation with the Cossack uprisings in Ukraine, which reversed migration flows and sent refugees westward, yet Poland–Lithuania remained the demographic and cultural heartland of Ashkenazic Jewry. Following the partitions of Poland, most of its Jews came under Russian rule and were confined to the "Pale of Settlement." The 18th century also witnessed new religious and intellectual currents. Hasidism, founded by Baal Shem Tov, emphasized mysticism and piety, while its opponents, the Misnagdim ("opponents") led by the Vilna Gaon, defended rabbinic scholarship and tradition. In Western Europe, during the 1760s and 1770s, the Haskalah (Jewish Enlightenment) emerged in German-speaking lands, where figures such as Moses Mendelssohn promoted secular learning, vernacular literacy, and integration into European society. Elsewhere, Jews began to be re-admitted to Western Europe, including England, where Menasseh ben Israel petitioned Oliver Cromwell for their return. In the Americas, Jews of Sephardic descent first arrived as conversos in Spanish and Portuguese colonies, where many faced trial by Inquisition tribunals for "judaizing." A more durable presence began in Dutch Brazil, where Jews openly practiced their religion and established the first synagogues in the New World, before the Portuguese reconquest forced their dispersal to Amsterdam, the Caribbean, and North America. Sephardic communities took root in Curaçao, Suriname, Jamaica, and Barbados, later joined by Ashkenazi migrants. In North America, Jews were present from the mid-17th century, with New Amsterdam hosting the first organized congregation in 1654. By the time of the American Revolution, small communities in New York, Newport, Philadelphia, Savannah, and Charleston played an active role in the struggle for independence. In the late 19th century, Jews in Western Europe gradually achieved legal emancipation, though social acceptance remained limited by persistent antisemitism and rising nationalism. In Eastern Europe, particularly within the Russian Empire's Pale of Settlement, Jews faced mounting legal restrictions and recurring pogroms. From this environment emerged Zionism, a national revival movement originating in Central and Eastern Europe that sought to re-establish a Jewish polity in the Land of Israel as a means of returning the Jewish people to their ancestral homeland and ending centuries of exile and persecution. This led to waves of Jewish migration to Ottoman-controlled Palestine. Theodor Herzl, who is considered the father of political Zionism, offered his vision of a future Jewish state in his 1896 book Der Judenstaat (The Jewish State); a year later, he presided over the First Zionist Congress. The antisemitism that inflicted Jewish communities in Europe also triggered a mass exodus of 2.8 million Jews to the United States between 1881 and 1924. Despite this, some Jews of Europe and the United States were able to make great achievements in various fields of science and culture. Among the most influential from this period are Albert Einstein in physics, Sigmund Freud in psychology, Franz Kafka in literature, and Irving Berlin in music. Many Nobel Prize winners at this time were Jewish, as is still the case. When Adolf Hitler and the Nazi Party came to power in Germany in 1933, the situation for Jews deteriorated rapidly as a direct result of Nazi policies. Many Jews fled from Europe to Mandatory Palestine, the United States, and the Soviet Union as a result of racial anti-Semitic laws, economic difficulties, and the fear of an impending war. World War II started in 1939, and by 1941, Hitler occupied almost all of Europe. Following the German invasion of the Soviet Union in 1941, the Final Solution—an extensive, organized effort with an unprecedented scope intended to annihilate the Jewish people—began, and resulted in the persecution and murder of Jews in Europe and North Africa. In Poland, three million were murdered in gas chambers in all concentration camps combined, with one million at the Auschwitz camp complex alone. The Holocaust is the name given to this genocide, in which six million Jews in total were systematically murdered. Before and during the Holocaust, enormous numbers of Jews immigrated to Mandatory Palestine. In 1944, the Jewish insurgency in Mandatory Palestine began with the aim of gaining full independence from the United Kingdom. On 14 May 1948, upon the termination of the mandate, David Ben-Gurion declared the creation of the State of Israel, a Jewish and democratic state. Immediately afterwards, all neighboring Arab states invaded, and were resisted by the newly formed Israel Defense Forces. In 1949, the war ended and Israel started building its state and absorbing waves of Aliyah, granting citizenship to Jews all over the world via the Law of Return passed in 1950. However, both the Israeli–Palestinian conflict and wider Arab–Israeli conflict continue to this day. Culture The Jewish people and the religion of Judaism are strongly interrelated. Converts to Judaism have a status within the Jewish people equal to those born into it. However, converts who go on to practice no Judaism are likely to be viewed with skepticism. Mainstream Judaism does not proselytize, and conversion is considered a difficult task. A significant portion of conversions are undertaken by children of mixed marriages, or would-be or current spouses of Jews. The Hebrew Bible, a religious interpretation of the traditions and early history of the Jews, established the first of the Abrahamic religions, which are now practiced by 54 percent of the world. Judaism guides its adherents in both practice and belief, and has been called not only a religion, but also a "way of life," which has made drawing a clear distinction between Judaism, Jewish culture, and Jewish identity rather difficult. Throughout history, in eras and places as diverse as the ancient Hellenic world, in Europe before and after The Age of Enlightenment (see Haskalah), in Islamic Spain and Portugal, in North Africa and the Middle East, India, China, or the contemporary United States and Israel, cultural phenomena have developed that are in some sense characteristically Jewish without being at all specifically religious. Some factors in this come from within Judaism, others from the interaction of Jews or specific communities of Jews with their surroundings, and still others from the inner social and cultural dynamics of the community, as opposed to from the religion itself. This phenomenon has led to considerably different Jewish cultures unique to their own communities. Hebrew is the liturgical language of Judaism (termed lashon ha-kodesh, "the holy tongue"), the language in which most of the Hebrew scriptures (Tanakh) were composed, and the daily speech of the Jewish people for centuries. By the 5th century BCE, Aramaic, a closely related tongue, joined Hebrew as the spoken language in Judea. By the 3rd century BCE, some Jews of the diaspora were speaking Greek. Others, such as in the Jewish communities of Asoristan, known to Jews as Babylonia, were speaking Hebrew and Aramaic, the languages of the Babylonian Talmud. Dialects of these same languages were also used by the Jews of Syria Palaestina at that time.[citation needed] For centuries, Jews worldwide have spoken the local or dominant languages of the regions they migrated to, often developing distinctive dialectal forms or branches that became independent languages. Yiddish is the Judaeo-German language developed by Ashkenazi Jews who migrated to Central Europe. Ladino is the Judaeo-Spanish language developed by Sephardic Jews who migrated to the Iberian Peninsula. Due to many factors, including the impact of the Holocaust on European Jewry, the Jewish exodus from Arab and Muslim countries, and widespread emigration from other Jewish communities around the world, ancient and distinct Jewish languages of several communities, including Judaeo-Georgian, Judaeo-Arabic, Judaeo-Berber, Krymchak, Judaeo-Malayalam and many others, have largely fallen out of use. For over sixteen centuries Hebrew was used almost exclusively as a liturgical language, and as the language in which most books had been written on Judaism, with a few speaking only Hebrew on the Sabbath. Hebrew was revived as a spoken language by Eliezer ben Yehuda, who arrived in Palestine in 1881. It had not been used as a mother tongue since Tannaic times. Modern Hebrew is designated as the "State language" of Israel. Despite efforts to revive Hebrew as the national language of the Jewish people, knowledge of the language is not commonly possessed by Jews worldwide and English has emerged as the lingua franca of the Jewish diaspora. Although many Jews once had sufficient knowledge of Hebrew to study the classic literature, and Jewish languages like Yiddish and Ladino were commonly used as recently as the early 20th century, most Jews lack such knowledge today and English has by and large superseded most Jewish vernaculars. The three most commonly spoken languages among Jews today are Hebrew, English, and Russian. Some Romance languages, particularly French and Spanish, are also widely used. Yiddish has been spoken by more Jews in history than any other language, but it is far less used today following the Holocaust and the adoption of Modern Hebrew by the Zionist movement and the State of Israel. In some places, the mother language of the Jewish community differs from that of the general population or the dominant group. For example, in Quebec, the Ashkenazic majority has adopted English, while the Sephardic minority uses French as its primary language. Similarly, South African Jews adopted English rather than Afrikaans. Due to both Czarist and Soviet policies, Russian has superseded Yiddish as the language of Russian Jews, but these policies have also affected neighboring communities. Today, Russian is the first language for many Jewish communities in a number of Post-Soviet states, such as Ukraine and Uzbekistan,[better source needed] as well as for Ashkenazic Jews in Azerbaijan, Georgia, and Tajikistan. Although communities in North Africa today are small and dwindling, Jews there had shifted from a multilingual group to a monolingual one (or nearly so), speaking French in Algeria, Morocco, and the city of Tunis, while most North Africans continue to use Arabic or Berber as their mother tongue.[citation needed] There is no single governing body for the Jewish community, nor a single authority with responsibility for religious doctrine. Instead, a variety of secular and religious institutions at the local, national, and international levels lead various parts of the Jewish community on a variety of issues. Today, many countries have a Chief Rabbi who serves as a representative of that country's Jewry. Although many Hasidic Jews follow a certain hereditary Hasidic dynasty, there is no one commonly accepted leader of all Hasidic Jews. Many Jews believe that the Messiah will act a unifying leader for Jews and the entire world. A number of modern scholars of nationalism support the existence of Jewish national identity in antiquity. One of them is David Goodblatt, who generally believes in the existence of nationalism before the modern period. In his view, the Bible, the parabiblical literature and the Jewish national history provide the base for a Jewish collective identity. Although many of the ancient Jews were illiterate (as were their neighbors), their national narrative was reinforced through public readings. The Hebrew language also constructed and preserved national identity. Although it was not widely spoken after the 5th century BCE, Goodblatt states: the mere presence of the language in spoken or written form could invoke the concept of a Jewish national identity. Even if one knew no Hebrew or was illiterate, one could recognize that a group of signs was in Hebrew script. ... It was the language of the Israelite ancestors, the national literature, and the national religion. As such it was inseparable from the national identity. Indeed its mere presence in visual or aural medium could invoke that identity. Anthony D. Smith, an historical sociologist considered one of the founders of the field of nationalism studies, wrote that the Jews of the late Second Temple period provide "a closer approximation to the ideal type of the nation [...] than perhaps anywhere else in the ancient world." He adds that this observation "must make us wary of pronouncing too readily against the possibility of the nation, and even a form of religious nationalism, before the onset of modernity." Agreeing with Smith, Goodblatt suggests omitting the qualifier "religious" from Smith's definition of ancient Jewish nationalism, noting that, according to Smith, a religious component in national memories and culture is common even in the modern era. This view is echoed by political scientist Tom Garvin, who writes that "something strangely like modern nationalism is documented for many peoples in medieval times and in classical times as well," citing the ancient Jews as one of several "obvious examples", alongside the classical Greeks and the Gaulish and British Celts. Fergus Millar suggests that the sources of Jewish national identity and their early nationalist movements in the first and second centuries CE included several key elements: the Bible as both a national history and legal source, the Hebrew language as a national language, a system of law, and social institutions such as schools, synagogues, and Sabbath worship. Adrian Hastings argued that Jews are the "true proto-nation", that through the model of ancient Israel found in the Hebrew Bible, provided the world with the original concept of nationhood which later influenced Christian nations. However, following Jerusalem's destruction in the first century CE, Jews ceased to be a political entity and did not resemble a traditional nation-state for almost two millennia. Despite this, they maintained their national identity through collective memory, religion and sacred texts, even without land or political power, and remained a nation rather than just an ethnic group, eventually leading to the rise of Zionism and the establishment of Israel. Steven Weitzman suggests that Jewish nationalist sentiment in antiquity was encouraged because under foreign rule (Persians, Greeks, Romans) Jews were able to claim that they were an ancient nation. This claim was based on the preservation and reverence of their scriptures, the Hebrew language, the Temple and priesthood, and other traditions of their ancestors. Doron Mendels further observes that the Hasmonean kingdom, one of the few examples of indigenous statehood at its time, significantly reinforced Jewish national consciousness. The memory of this period of independence contributed to the persistent efforts to revive Jewish sovereignty in Judea, leading to the major revolts against Roman rule in the 1st and 2nd centuries CE. Demographics Within the world's Jewish population there are distinct ethnic divisions, most of which are primarily the result of geographic branching from an originating Israelite population, and subsequent independent evolutions. An array of Jewish communities was established by Jewish settlers in various places around the Old World, often at great distances from one another, resulting in effective and often long-term isolation. During the millennia of the Jewish diaspora the communities would develop under the influence of their local environments: political, cultural, natural, and populational. Today, manifestations of these differences among the Jews can be observed in Jewish cultural expressions of each community, including Jewish linguistic diversity, culinary preferences, liturgical practices, religious interpretations, as well as degrees and sources of genetic admixture. Jews are often identified as belonging to one of two major groups: the Ashkenazim and the Sephardim. Ashkenazim are so named in reference to their geographical origins (their ancestors' culture coalesced in the Rhineland, an area historically referred to by Jews as Ashkenaz). Similarly, Sephardim (Sefarad meaning "Spain" in Hebrew) are named in reference their origins in Iberia. The diverse groups of Jews of the Middle East and North Africa are often collectively referred to as Sephardim together with Sephardim proper for liturgical reasons having to do with their prayer rites. A common term for many of these non-Spanish Jews who are sometimes still broadly grouped as Sephardim is Mizrahim (lit. 'easterners' in Hebrew). Nevertheless, Mizrahis and Sepharadim are usually ethnically distinct. Smaller groups include, but are not restricted to, Indian Jews such as the Bene Israel, Bnei Menashe, Cochin Jews, and Bene Ephraim; the Romaniotes of Greece; the Italian Jews ("Italkim" or "Bené Roma"); the Teimanim from Yemen; various African Jews, including most numerously the Beta Israel of Ethiopia; and Chinese Jews, most notably the Kaifeng Jews, as well as various other distinct but now almost extinct communities. The divisions between all these groups are approximate and their boundaries are not always clear. The Mizrahim for example, are a heterogeneous collection of North African, Central Asian, Caucasian, and Middle Eastern Jewish communities that are no closer related to each other than they are to any of the earlier mentioned Jewish groups. In modern usage, however, the Mizrahim are sometimes termed Sephardi due to similar styles of liturgy, despite independent development from Sephardim proper. Thus, among Mizrahim there are Egyptian Jews, Iraqi Jews, Lebanese Jews, Kurdish Jews, Moroccan Jews, Libyan Jews, Syrian Jews, Bukharian Jews, Mountain Jews, Georgian Jews, Iranian Jews, Afghan Jews, and various others. The Teimanim from Yemen are sometimes included, although their style of liturgy is unique and they differ in respect to the admixture found among them to that found in Mizrahim. In addition, there is a differentiation made between Sephardi migrants who established themselves in the Middle East and North Africa after the expulsion of the Jews from Spain and Portugal in the 1490s and the pre-existing Jewish communities in those regions. Ashkenazi Jews represent the bulk of modern Jewry, with at least 70 percent of Jews worldwide (and up to 90 percent prior to World War II and the Holocaust). As a result of their emigration from Europe, Ashkenazim also represent the overwhelming majority of Jews in the New World continents, in countries such as the United States, Canada, Argentina, Australia, and Brazil. In France, the immigration of Jews from Algeria (Sephardim) has led them to outnumber the Ashkenazim. Only in Israel is the Jewish population representative of all groups, a melting pot independent of each group's proportion within the overall world Jewish population. Y DNA studies tend to imply a small number of founders in an old population whose members parted and followed different migration paths. In most Jewish populations, these male line ancestors appear to have been mainly Middle Eastern. For example, Ashkenazi Jews share more common paternal lineages with other Jewish and Middle Eastern groups than with non-Jewish populations in areas where Jews lived in Eastern Europe, Germany, and the French Rhine Valley. This is consistent with Jewish traditions in placing most Jewish paternal origins in the region of the Middle East. Conversely, the maternal lineages of Jewish populations, studied by looking at mitochondrial DNA, are generally more heterogeneous. Scholars such as Harry Ostrer and Raphael Falk believe this indicates that many Jewish males found new mates from European and other communities in the places where they migrated in the diaspora after fleeing ancient Israel. In contrast, Behar has found evidence that about 40 percent of Ashkenazi Jews originate maternally from just four female founders, who were of Middle Eastern origin. The populations of Sephardi and Mizrahi Jewish communities "showed no evidence for a narrow founder effect." Subsequent studies carried out by Feder et al. confirmed the large portion of non-local maternal origin among Ashkenazi Jews. Reflecting on their findings related to the maternal origin of Ashkenazi Jews, the authors conclude "Clearly, the differences between Jews and non-Jews are far larger than those observed among the Jewish communities. Hence, differences between the Jewish communities can be overlooked when non-Jews are included in the comparisons." However, a 2025 genetic study on the Ashkenazi Jewish founder population supports the presence of a substantial Near Eastern component in the maternal lineages. Analyses of mitochondrial DNA (mtDNA) indicate that the core founder lineages, estimated at around 54, likely originated from the Near East, with these founder signatures appearing in multiple copies across the population. While later admixture introduced additional mtDNA lineages, these absorbed lineages are distinguishable from the original founders. The findings are consistent with genome-wide Identity-by-Descent and Lineage Extinction analyses, reinforcing the Near Eastern origin of the Ashkenazi maternal founders. A study showed that 7% of Ashkenazi Jews have the haplogroup G2c, which is mainly found in Pashtuns and on lower scales all major Jewish groups, Palestinians, Syrians, and Lebanese. Studies of autosomal DNA, which look at the entire DNA mixture, have become increasingly important as the technology develops. They show that Jewish populations have tended to form relatively closely related groups in independent communities, with most in a community sharing significant ancestry in common. For Jewish populations of the diaspora, the genetic composition of Ashkenazi, Sephardic, and Mizrahi Jewish populations show a predominant amount of shared Middle Eastern ancestry. According to Behar, the most parsimonious explanation for this shared Middle Eastern ancestry is that it is "consistent with the historical formulation of the Jewish people as descending from ancient Hebrew and Israelite residents of the Levant" and "the dispersion of the people of ancient Israel throughout the Old World". North African, Italian and others of Iberian origin show variable frequencies of admixture with non-Jewish historical host populations among the maternal lines. In the case of Ashkenazi and Sephardi Jews (in particular Moroccan Jews), who are closely related, the source of non-Jewish admixture is mainly Southern European, while Mizrahi Jews show evidence of admixture with other Middle Eastern populations. Behar et al. have remarked on a close relationship between Ashkenazi Jews and modern Italians. A 2001 study found that Jews were more closely related to groups of the Fertile Crescent (Kurds, Turks, and Armenians) than to their Arab neighbors, whose genetic signature was found in geographic patterns reflective of Islamic conquests. The studies also show that Sephardic Bnei Anusim (descendants of the "anusim" who were forced to convert to Catholicism), which comprise up to 19.8 percent of the population of today's Iberia (Spain and Portugal) and at least 10 percent of the population of Ibero-America (Hispanic America and Brazil), have Sephardic Jewish ancestry within the last few centuries. The Bene Israel and Cochin Jews of India, Beta Israel of Ethiopia, and a portion of the Lemba people of Southern Africa, despite more closely resembling the local populations of their native countries, have also been thought to have some more remote ancient Jewish ancestry. Views on the Lemba have changed and genetic Y-DNA analyses in the 2000s have established a partially Middle-Eastern origin for a portion of the male Lemba population but have been unable to narrow this down further. Although historically, Jews have been found all over the world, in the decades since World War II and the establishment of Israel, they have increasingly concentrated in a small number of countries. In 2021, Israel and the United States together accounted for over 85 percent of the global Jewish population, with approximately 45.3% and 39.6% of the world's Jews, respectively. More than half (51.2%) of world Jewry resides in just ten metropolitan areas. As of 2021, these ten areas were Tel Aviv, New York, Jerusalem, Haifa, Los Angeles, Miami, Philadelphia, Paris, Washington, and Chicago. The Tel Aviv metro area has the highest percent of Jews among the total population (94.8%), followed by Jerusalem (72.3%), Haifa (73.1%), and Beersheba (60.4%), the balance mostly being Israeli Arabs. Outside Israel, the highest percent of Jews in a metropolitan area was in New York (10.8%), followed by Miami (8.7%), Philadelphia (6.8%), San Francisco (5.1%), Washington (4.7%), Los Angeles (4.7%), Toronto (4.5%), and Baltimore (4.1%). As of 2010, there were nearly 14 million Jews around the world, roughly 0.2% of the world's population at the time. According to the 2007 estimates of The Jewish People Policy Planning Institute, the world's Jewish population is 13.2 million. This statistic incorporates both practicing Jews affiliated with synagogues and the Jewish community, and approximately 4.5 million unaffiliated and secular Jews.[citation needed] According to Sergio Della Pergola, a demographer of the Jewish population, in 2021 there were about 6.8 million Jews in Israel, 6 million in the United States, and 2.3 million in the rest of the world. Israel, the Jewish nation-state, is the only country in which Jews make up a majority of the citizens. Israel was established as an independent democratic and Jewish state on 14 May 1948. Of the 120 members in its parliament, the Knesset, as of 2016[update], 14 members of the Knesset are Arab citizens of Israel (not including the Druze), most representing Arab political parties. One of Israel's Supreme Court judges is also an Arab citizen of Israel. Between 1948 and 1958, the Jewish population rose from 800,000 to two million. Currently, Jews account for 75.4 percent of the Israeli population, or 6 million people. The early years of the State of Israel were marked by the mass immigration of Holocaust survivors in the aftermath of the Holocaust and Jews fleeing Arab lands. Israel also has a large population of Ethiopian Jews, many of whom were airlifted to Israel in the late 1980s and early 1990s. Between 1974 and 1979 nearly 227,258 immigrants arrived in Israel, about half being from the Soviet Union. This period also saw an increase in immigration to Israel from Western Europe, Latin America, and North America. A trickle of immigrants from other communities has also arrived, including Indian Jews and others, as well as some descendants of Ashkenazi Holocaust survivors who had settled in countries such as the United States, Argentina, Australia, Chile, and South Africa. Some Jews have emigrated from Israel elsewhere, because of economic problems or disillusionment with political conditions and the continuing Arab–Israeli conflict. Jewish Israeli emigrants are known as yordim. The waves of immigration to the United States and elsewhere at the turn of the 19th century, the founding of Zionism and later events, including pogroms in Imperial Russia (mostly within the Pale of Settlement in present-day Ukraine, Moldova, Belarus and eastern Poland), the massacre of European Jewry during the Holocaust, and the founding of the state of Israel, with the subsequent Jewish exodus from Arab lands, all resulted in substantial shifts in the population centers of world Jewry by the end of the 20th century. More than half of the Jews live in the Diaspora (see Population table). Currently, the largest Jewish community outside Israel, and either the largest or second-largest Jewish community in the world, is located in the United States, with 6 million to 7.5 million Jews by various estimates. Elsewhere in the Americas, there are also large Jewish populations in Canada (315,000), Argentina (180,000–300,000), and Brazil (196,000–600,000), and smaller populations in Mexico, Uruguay, Venezuela, Chile, Colombia and several other countries (see History of the Jews in Latin America). According to a 2010 Pew Research Center study, about 470,000 people of Jewish heritage live in Latin America and the Caribbean. Demographers disagree on whether the United States has a larger Jewish population than Israel, with many maintaining that Israel surpassed the United States in Jewish population during the 2000s, while others maintain that the United States still has the largest Jewish population in the world. Currently, a major national Jewish population survey is planned to ascertain whether or not Israel has overtaken the United States in Jewish population. Western Europe's largest Jewish community, and the third-largest Jewish community in the world, can be found in France, home to between 483,000 and 500,000 Jews, the majority of whom are immigrants or refugees from North African countries such as Algeria, Morocco, and Tunisia (or their descendants). The United Kingdom has a Jewish community of 292,000. In Eastern Europe, the exact figures are difficult to establish. The number of Jews in Russia varies widely according to whether a source uses census data (which requires a person to choose a single nationality among choices that include "Russian" and "Jewish") or eligibility for immigration to Israel (which requires that a person have one or more Jewish grandparents). According to the latter criteria, the heads of the Russian Jewish community assert that up to 1.5 million Russians are eligible for aliyah. In Germany, the 102,000 Jews registered with the Jewish community are a slowly declining population, despite the immigration of tens of thousands of Jews from the former Soviet Union since the fall of the Berlin Wall. Thousands of Israelis also live in Germany, either permanently or temporarily, for economic reasons. Prior to 1948, approximately 800,000 Jews were living in lands which now make up the Arab world (excluding Israel). Of these, just under two-thirds lived in the French-controlled Maghreb region, 15 to 20 percent in the Kingdom of Iraq, approximately 10 percent in the Kingdom of Egypt and approximately 7 percent in the Kingdom of Yemen. A further 200,000 lived in Pahlavi Iran and the Republic of Turkey. Today, around 26,000 Jews live in Muslim-majority countries, mainly in Turkey (14,200) and Iran (9,100), while Morocco (2,000), Tunisia (1,000), and the United Arab Emirates (500) host the largest communities in the Arab world. A small-scale exodus had begun in many countries in the early decades of the 20th century, although the only substantial aliyah came from Yemen and Syria. The exodus from Arab and Muslim countries took place primarily from 1948. The first large-scale exoduses took place in the late 1940s and early 1950s, primarily in Iraq, Yemen and Libya, with up to 90 percent of these communities leaving within a few years. The peak of the exodus from Egypt occurred in 1956. The exodus in the Maghreb countries peaked in the 1960s. Lebanon was the only Arab country to see a temporary increase in its Jewish population during this period, due to an influx of refugees from other Arab countries, although by the mid-1970s the Jewish community of Lebanon had also dwindled. In the aftermath of the exodus wave from Arab states, an additional migration of Iranian Jews peaked in the 1980s when around 80 percent of Iranian Jews left the country.[citation needed] Outside Europe, the Americas, the Middle East, and the rest of Asia, there are significant Jewish populations in Australia (112,500) and South Africa (70,000). There is also a 6,800-strong community in New Zealand. Since at least the time of the Ancient Greeks, a proportion of Jews have assimilated into the wider non-Jewish society around them, by either choice or force, ceasing to practice Judaism and losing their Jewish identity. Assimilation took place in all areas, and during all time periods, with some Jewish communities, for example the Kaifeng Jews of China, disappearing entirely. The advent of the Jewish Enlightenment of the 18th century (see Haskalah) and the subsequent emancipation of the Jewish populations of Europe and America in the 19th century, accelerated the situation, encouraging Jews to increasingly participate in, and become part of, secular society. The result has been a growing trend of assimilation, as Jews marry non-Jewish spouses and stop participating in the Jewish community. Rates of interreligious marriage vary widely: In the United States, it is just under 50 percent; in the United Kingdom, around 53 percent; in France, around 30 percent; and in Australia and Mexico, as low as 10 percent. In the United States, only about a third of children from intermarriages affiliate with Jewish religious practice. The result is that most countries in the Diaspora have steady or slightly declining religiously Jewish populations as Jews continue to assimilate into the countries in which they live.[citation needed] The Jewish people and Judaism have experienced various persecutions throughout their history. During Late Antiquity and the Early Middle Ages, the Roman Empire (in its later phases known as the Byzantine Empire) repeatedly repressed the Jewish population, first by ejecting them from their homelands during the pagan Roman era and later by officially establishing them as second-class citizens during the Christian Roman era. According to James Carroll, "Jews accounted for 10% of the total population of the Roman Empire. By that ratio, if other factors had not intervened, there would be 200 million Jews in the world today, instead of something like 13 million." Later in medieval Western Europe, further persecutions of Jews by Christians occurred, notably during the Crusades—when Jews all over Germany were massacred—and in a series of expulsions from the Kingdom of England, Germany, and France. Then there occurred the largest expulsion of all, when Spain and Portugal, after the Reconquista (the Catholic Reconquest of the Iberian Peninsula), expelled both unbaptized Sephardic Jews and the ruling Muslim Moors. In the Papal States, which existed until 1870, Jews were required to live only in specified neighborhoods called ghettos. Islam and Judaism have a complex relationship. Traditionally Jews and Christians living in Muslim lands, known as dhimmis, were allowed to practice their religions and administer their internal affairs, but they were subject to certain conditions. They had to pay the jizya (a per capita tax imposed on free adult non-Muslim males) to the Islamic state. Dhimmis had an inferior status under Islamic rule. They had several social and legal disabilities such as prohibitions against bearing arms or giving testimony in courts in cases involving Muslims. Many of the disabilities were highly symbolic. The one described by Bernard Lewis as "most degrading" was the requirement of distinctive clothing, not found in the Quran or hadith but invented in early medieval Baghdad; its enforcement was highly erratic. On the other hand, Jews rarely faced martyrdom or exile, or forced compulsion to change their religion, and they were mostly free in their choice of residence and profession. Notable exceptions include the massacre of Jews and forcible conversion of some Jews by the rulers of the Almohad dynasty in Al-Andalus in the 12th century, as well as in Islamic Persia, and the forced confinement of Moroccan Jews to walled quarters known as mellahs beginning from the 15th century and especially in the early 19th century. In modern times, it has become commonplace for standard antisemitic themes to be conflated with anti-Zionist publications and pronouncements of Islamic movements such as Hezbollah and Hamas, in the pronouncements of various agencies of the Islamic Republic of Iran, and even in the newspapers and other publications of Turkish Refah Partisi."[better source needed] Throughout history, many rulers, empires and nations have oppressed their Jewish populations or sought to eliminate them entirely. Methods employed ranged from expulsion to outright genocide; within nations, often the threat of these extreme methods was sufficient to silence dissent. The history of antisemitism includes the First Crusade which resulted in the massacre of Jews; the Spanish Inquisition (led by Tomás de Torquemada) and the Portuguese Inquisition, with their persecution and autos-da-fé against the New Christians and Marrano Jews; the Bohdan Chmielnicki Cossack massacres in Ukraine; the Pogroms backed by the Russian Tsars; as well as expulsions from Spain, Portugal, England, France, Germany, and other countries in which the Jews had settled. According to a 2008 study published in the American Journal of Human Genetics, 19.8 percent of the modern Iberian population has Sephardic Jewish ancestry, indicating that the number of conversos may have been much higher than originally thought. The persecution reached a peak in Nazi Germany's Final Solution, which led to the Holocaust and the slaughter of approximately 6 million Jews. Of the world's 16 million Jews in 1939, almost 40% were murdered in the Holocaust. The Holocaust—the state-led systematic persecution and genocide of European Jews (and certain communities of North African Jews in European controlled North Africa) and other minority groups of Europe during World War II by Germany and its collaborators—remains the most notable modern-day persecution of Jews. The persecution and genocide were accomplished in stages. Legislation to remove the Jews from civil society was enacted years before the outbreak of World War II. Concentration camps were established in which inmates were used as slave labour until they died of exhaustion or disease. Where the Third Reich conquered new territory in Eastern Europe, specialized units called Einsatzgruppen murdered Jews and political opponents in mass shootings. Jews and Roma were crammed into ghettos before being transported hundreds of kilometres by freight train to extermination camps where, if they survived the journey, the majority of them were murdered in gas chambers. Virtually every arm of Germany's bureaucracy was involved in the logistics of the mass murder, turning the country into what one Holocaust scholar has called "a genocidal nation." Throughout Jewish history, Jews have repeatedly been directly or indirectly expelled from both their original homeland, the Land of Israel, and many of the areas in which they have settled. This experience as refugees has shaped Jewish identity and religious practice in many ways, and is thus a major element of Jewish history. In summary, the pogroms in Eastern Europe, the rise of modern antisemitism, the Holocaust, as well as the rise of Arab nationalism, all served to fuel the movements and migrations of huge segments of Jewry from land to land and continent to continent until they arrived back in large numbers at their original historical homeland in Israel. In the Bible, the patriarch Abraham is described as a migrant to the land of Canaan from Ur of the Chaldees. His descendants, the Children of Israel, undertook the Exodus (meaning "departure" or "exit" in Greek) from ancient Egypt, as described in the Book of Exodus. The first movement documented in the historical record occurred with the resettlement policy of the Neo-Assyrian Empire, which mandated the deportation of conquered peoples, and it is estimated some 4,500,000 among its captive populations suffered this dislocation over three centuries of Assyrian rule. With regard to Israel, Tiglath-Pileser III claims he deported 80% of the population of Lower Galilee, some 13,520 people. Some 27,000 Israelites, 20 to 25% of the population of the Kingdom of Israel, were described as being deported by Sargon II, and were replaced by other deported populations and sent into permanent exile by Assyria, initially to the Upper Mesopotamian provinces of the Assyrian Empire. Between 10,000 and 80,000 people from the Kingdom of Judah were similarly exiled by Babylonia, but these people were then returned to Judea by Cyrus the Great of the Persian Achaemenid Empire. Many Jews were exiled again by the Roman Empire. The 2,000 year dispersion of the Jewish diaspora beginning under the Roman Empire, as Jews were spread throughout the Roman world and, driven from land to land, settled wherever they could live freely enough to practice their religion. Over the course of the diaspora the center of Jewish life moved from Babylonia to the Iberian Peninsula to Poland to the United States and, as a result of Zionism, back to Israel. There were also many expulsions of Jews during the Middle Ages and Enlightenment in Europe, including: 1290, 16,000 Jews were expelled from England, (see the Statute of Jewry); in 1396, 100,000 from France; in 1421, thousands were expelled from Austria. Many of these Jews settled in East-Central Europe, especially Poland. Following the Spanish Inquisition in 1492, the Spanish population of around 200,000 Sephardic Jews were expelled by the Spanish crown and Catholic church, followed by expulsions in 1493 in Sicily (37,000 Jews) and Portugal in 1496. The expelled Jews fled mainly to the Ottoman Empire, the Netherlands, and North Africa, others migrating to Southern Europe and the Middle East. During the 19th century, France's policies of equal citizenship regardless of religion led to the immigration of Jews (especially from Eastern and Central Europe). This contributed to the arrival of millions of Jews in the New World. Over two million Eastern European Jews arrived in the United States from 1880 to 1925. In the latest phase of migrations, the Islamic Revolution of Iran caused many Iranian Jews to flee Iran. Most found refuge in the US (particularly Los Angeles, California, and Long Island, New York) and Israel. Smaller communities of Persian Jews exist in Canada and Western Europe. Similarly, when the Soviet Union collapsed, many of the Jews in the affected territory (who had been refuseniks) were suddenly allowed to leave. This produced a wave of migration to Israel in the early 1990s. Israel is the only country with a Jewish population that is consistently growing through natural population growth, although the Jewish populations of other countries, in Europe and North America, have recently increased through immigration. In the Diaspora, in almost every country the Jewish population in general is either declining or steady, but Orthodox and Haredi Jewish communities, whose members often shun birth control for religious reasons, have experienced rapid population growth. Orthodox and Conservative Judaism discourage proselytism to non-Jews, but many Jewish groups have tried to reach out to the assimilated Jewish communities of the Diaspora in order for them to reconnect to their Jewish roots. Additionally, while in principle Reform Judaism favours seeking new members for the faith, this position has not translated into active proselytism, instead taking the form of an effort to reach out to non-Jewish spouses of intermarried couples. There is also a trend of Orthodox movements reaching out to secular Jews in order to give them a stronger Jewish identity so there is less chance of intermarriage. As a result of the efforts by these and other Jewish groups over the past 25 years, there has been a trend (known as the Baal teshuva movement) for secular Jews to become more religiously observant, though the demographic implications of the trend are unknown. Additionally, there is also a growing rate of conversion to Jews by Choice of gentiles who make the decision to head in the direction of becoming Jews. Contributions Jewish individuals have played a significant role in the development and growth of Western culture, advancing many fields of thought, science and technology, both historically and in modern times, including through discrete trends in Jewish philosophy, Jewish ethics and Jewish literature, as well as specific trends in Jewish culture, including in Jewish art, Jewish music, Jewish humor, Jewish theatre, Jewish cuisine and Jewish medicine. Jews have established various Jewish political movements, religious movements, and, through the authorship of the Hebrew Bible and parts of the New Testament, provided the foundation for Christianity and Islam. More than 20 percent of the awarded Nobel Prize have gone to individuals of Jewish descent. Philanthropic giving is a widespread core function among Jewish organizations. Notes References External links |
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Contents Black hole A black hole is an astronomical body so compact that its gravity prevents anything, including light, from escaping. Albert Einstein's theory of general relativity predicts that a sufficiently compact mass will form a black hole. The boundary of no escape is called the event horizon. In general relativity, a black hole's event horizon seals an object's fate but produces no locally detectable change when crossed. General relativity also predicts that every black hole should have a central singularity, where the curvature of spacetime is infinite. In many ways, a black hole acts like an ideal black body, as it reflects no light. Quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is of the order of billionths of a kelvin for stellar black holes, making it essentially impossible to observe directly. Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace. In 1916, Karl Schwarzschild found the first modern solution of general relativity that would characterise a black hole. Due to his influential research, the Schwarzschild metric is named after him. David Finkelstein, in 1958, first interpreted Schwarzschild's model as a region of space from which nothing can escape. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The first black hole known was Cygnus X-1, identified by several researchers independently in 1971. Black holes typically form when massive stars collapse at the end of their life cycle. After a black hole has formed, it can grow by absorbing mass from its surroundings. Supermassive black holes of millions of solar masses may form by absorbing other stars and merging with other black holes, or via direct collapse of gas clouds. There is consensus that supermassive black holes exist in the centres of most galaxies. The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter falling toward a black hole can form an accretion disk of infalling plasma, heated by friction and emitting light. In extreme cases, this creates a quasar, some of the brightest objects in the universe. Merging black holes can also be detected by observation of the gravitational waves they emit. If other stars are orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses. History The idea of a body so massive that even light could not escape was first proposed in the late 18th century by English astronomer and clergyman John Michell and independently by French scientist Pierre-Simon Laplace. Both scholars proposed very large stars in contrast to the modern concept of an extremely dense object. Michell's idea, in a short part of a letter published in 1784, calculated that a star with the same density but 500 times the radius of the sun would not let any emitted light escape; the surface escape velocity would exceed the speed of light.: 122 Michell correctly hypothesized that such supermassive but non-radiating bodies might be detectable through their gravitational effects on nearby visible bodies. In 1796, Laplace mentioned that a star could be invisible if it were sufficiently large while speculating on the origin of the Solar System in his book Exposition du Système du Monde. Franz Xaver von Zach asked Laplace for a mathematical analysis, which Laplace provided and published in a journal edited by von Zach. In 1905, Albert Einstein showed that the laws of electromagnetism would be invariant under a Lorentz transformation: they would be identical for observers travelling at different velocities relative to each other. This discovery became known as the principle of special relativity. Although the laws of mechanics had already been shown to be invariant, gravity remained yet to be included.: 19 In 1907, Einstein published a paper proposing his equivalence principle, the hypothesis that inertial mass and gravitational mass have a common cause. Using the principle, Einstein predicted the redshift and half of the lensing effect of gravity on light; the full prediction of gravitational lensing required development of general relativity.: 19 By 1915, Einstein refined these ideas into his general theory of relativity, which explained how matter affects spacetime, which in turn affects the motion of other matter. This formed the basis for black hole physics. Only a few months after Einstein published the field equations describing general relativity, astrophysicist Karl Schwarzschild set out to apply the idea to stars. He assumed spherical symmetry with no spin and found a solution to Einstein's equations.: 124 A few months after Schwarzschild, Johannes Droste, a student of Hendrik Lorentz, independently gave the same solution. At a certain radius from the center of the mass, the Schwarzschild solution became singular, meaning that some of the terms in the Einstein equations became infinite. The nature of this radius, which later became known as the Schwarzschild radius, was not understood at the time. Many physicists of the early 20th century were skeptical of the existence of black holes. In a 1926 popular science book, Arthur Eddington critiqued the idea of a star with mass compressed to its Schwarzschild radius as a flaw in the then-poorly-understood theory of general relativity.: 134 In 1939, Einstein himself used his theory of general relativity in an attempt to prove that black holes were impossible. His work relied on increasing pressure or increasing centrifugal force balancing the force of gravity so that the object would not collapse beyond its Schwarzschild radius. He missed the possibility that implosion would drive the system below this critical value.: 135 By the 1920s, astronomers had classified a number of white dwarf stars as too cool and dense to be explained by the gradual cooling of ordinary stars. In 1926, Ralph Fowler showed that quantum-mechanical degeneracy pressure was larger than thermal pressure at these densities.: 145 In 1931, Subrahmanyan Chandrasekhar calculated that a non-rotating body of electron-degenerate matter below a certain limiting mass is stable, and by 1934 he showed that this explained the catalog of white dwarf stars.: 151 When Chandrasekhar announced his results, Eddington pointed out that stars above this limit would radiate until they were sufficiently dense to prevent light from exiting, a conclusion he considered absurd. Eddington and, later, Lev Landau argued that some yet unknown mechanism would stop the collapse. In the 1930s, Fritz Zwicky and Walter Baade studied stellar novae, focusing on exceptionally bright ones they called supernovae. Zwicky promoted the idea that supernovae produced stars with the density of atomic nuclei—neutron stars—but this idea was largely ignored.: 171 In 1939, based on Chandrasekhar's reasoning, J. Robert Oppenheimer and George Volkoff predicted that neutron stars below a certain mass limit, later called the Tolman–Oppenheimer–Volkoff limit, would be stable due to neutron degeneracy pressure. Above that limit, they reasoned that either their model would not apply or that gravitational contraction would not stop.: 380 John Archibald Wheeler and two of his students resolved questions about the model behind the Tolman–Oppenheimer–Volkoff (TOV) limit. Harrison and Wheeler developed the equations of state relating density to pressure for cold matter all the way through electron degeneracy and neutron degeneracy. Masami Wakano and Wheeler then used the equations to compute the equilibrium curve for stars, relating mass to circumference. They found no additional features that would invalidate the TOV limit. This meant that the only thing that could prevent black holes from forming was a dynamic process ejecting sufficient mass from a star as it cooled.: 205 The modern concept of black holes was formulated by Robert Oppenheimer and his student Hartland Snyder in 1939.: 80 In the paper, Oppenheimer and Snyder solved Einstein's equations of general relativity for an idealized imploding star, in a model later called the Oppenheimer–Snyder model, then described the results from far outside the star. The implosion starts as one might expect: the star material rapidly collapses inward. However, as the density of the star increases, gravitational time dilation increases and the collapse, viewed from afar, seems to slow down further and further until the star reaches its Schwarzschild radius, where it appears frozen in time.: 217 In 1958, David Finkelstein identified the Schwarzschild surface as an event horizon, calling it "a perfect unidirectional membrane: causal influences can cross it in only one direction". In this sense, events that occur inside of the black hole cannot affect events that occur outside of the black hole. Finkelstein created a new reference frame to include the point of view of infalling observers.: 103 Finkelstein's new frame of reference allowed events at the surface of an imploding star to be related to events far away. By 1962 the two points of view were reconciled, convincing many skeptics that implosion into a black hole made physical sense.: 226 The era from the mid-1960s to the mid-1970s was the "golden age of black hole research", when general relativity and black holes became mainstream subjects of research.: 258 In this period, more general black hole solutions were found. In 1963, Roy Kerr found the exact solution for a rotating black hole. Two years later, Ezra Newman found the cylindrically symmetric solution for a black hole that is both rotating and electrically charged. In 1967, Werner Israel found that the Schwarzschild solution was the only possible solution for a nonspinning, uncharged black hole, meaning that a Schwarzschild black hole would be defined by its mass alone. Similar identities were later found for Reissner-Nordstrom and Kerr black holes, defined only by their mass and their charge or spin respectively. Together, these findings became known as the no-hair theorem, which states that a stationary black hole is completely described by the three parameters of the Kerr–Newman metric: mass, angular momentum, and electric charge. At first, it was suspected that the strange mathematical singularities found in each of the black hole solutions only appeared due to the assumption that a black hole would be perfectly spherically symmetric, and therefore the singularities would not appear in generic situations where black holes would not necessarily be symmetric. This view was held in particular by Vladimir Belinski, Isaak Khalatnikov, and Evgeny Lifshitz, who tried to prove that no singularities appear in generic solutions, although they would later reverse their positions. However, in 1965, Roger Penrose proved that general relativity without quantum mechanics requires that singularities appear in all black holes. Astronomical observations also made great strides during this era. In 1967, Antony Hewish and Jocelyn Bell Burnell discovered pulsars and by 1969, these were shown to be rapidly rotating neutron stars. Until that time, neutron stars, like black holes, were regarded as just theoretical curiosities, but the discovery of pulsars showed their physical relevance and spurred a further interest in all types of compact objects that might be formed by gravitational collapse. Based on observations in Greenwich and Toronto in the early 1970s, Cygnus X-1, a galactic X-ray source discovered in 1964, became the first astronomical object commonly accepted to be a black hole. Work by James Bardeen, Jacob Bekenstein, Carter, and Hawking in the early 1970s led to the formulation of black hole thermodynamics. These laws describe the behaviour of a black hole in close analogy to the laws of thermodynamics by relating mass to energy, area to entropy, and surface gravity to temperature. The analogy was completed: 442 when Hawking, in 1974, showed that quantum field theory implies that black holes should radiate like a black body with a temperature proportional to the surface gravity of the black hole, predicting the effect now known as Hawking radiation. While Cygnus X-1, a stellar-mass black hole, was generally accepted by the scientific community as a black hole by the end of 1973, it would be decades before a supermassive black hole would gain the same broad recognition. Although, as early as the 1960s, physicists such as Donald Lynden-Bell and Martin Rees had suggested that powerful quasars in the center of galaxies were powered by accreting supermassive black holes, little observational proof existed at the time. However, the Hubble Space Telescope, launched decades later, found that supermassive black holes were not only present in these active galactic nuclei, but that supermassive black holes in the center of galaxies were ubiquitous: Almost every galaxy had a supermassive black hole at its center, many of which were quiescent. In 1999, David Merritt proposed the M–sigma relation, which related the dispersion of the velocity of matter in the center bulge of a galaxy to the mass of the supermassive black hole at its core. Subsequent studies confirmed this correlation. Around the same time, based on telescope observations of the velocities of stars at the center of the Milky Way galaxy, independent work groups led by Andrea Ghez and Reinhard Genzel concluded that the compact radio source in the center of the galaxy, Sagittarius A*, was likely a supermassive black hole. On 11 February 2016, the LIGO Scientific Collaboration and Virgo Collaboration announced the first direct detection of gravitational waves, named GW150914, representing the first observation of a black hole merger. At the time of the merger, the black holes were approximately 1.4 billion light-years away from Earth and had masses of 30 and 35 solar masses.: 6 In 2017, Rainer Weiss, Kip Thorne, and Barry Barish, who had spearheaded the project, were awarded the Nobel Prize in Physics for their work. Since the initial discovery in 2015, hundreds more gravitational waves have been observed by LIGO and another interferometer, Virgo. On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope (EHT) in 2017 of the supermassive black hole in Messier 87's galactic centre. In 2022, the Event Horizon Telescope collaboration released an image of the black hole in the center of the Milky Way galaxy, Sagittarius A*; The data had been collected in 2017. In 2020, the Nobel Prize in Physics was awarded for work on black holes. Andrea Ghez and Reinhard Genzel shared one-half for their discovery that Sagittarius A* is a supermassive black hole. Penrose received the other half for his work showing that the mathematics of general relativity requires the formation of black holes. Cosmologists lamented that Hawking's extensive theoretical work on black holes would not be honored since he died in 2018. In December 1967, a student reportedly suggested the phrase black hole at a lecture by John Wheeler; Wheeler adopted the term for its brevity and "advertising value", and Wheeler's stature in the field ensured it quickly caught on, leading some to credit Wheeler with coining the phrase. However, the term was used by others around that time. Science writer Marcia Bartusiak traces the term black hole to physicist Robert H. Dicke, who in the early 1960s reportedly compared the phenomenon to the Black Hole of Calcutta, notorious as a prison where people entered but never left alive. The term was used in print by Life and Science News magazines in 1963, and by science journalist Ann Ewing in her article "'Black Holes' in Space", dated 18 January 1964, which was a report on a meeting of the American Association for the Advancement of Science held in Cleveland, Ohio. Definition A black hole is generally defined as a region of spacetime from which no information-carrying signals or objects can escape. However, verifying an object as a black hole by this definition would require waiting for an infinite time and at an infinite distance from the black hole to verify that indeed, nothing has escaped, and thus cannot be used to identify a physical black hole. Broadly, physicists do not have a precisely-agreed-upon definition of a black hole. Among astrophysicists, a black hole is a compact object with a mass larger than four solar masses. A black hole may also be defined as a reservoir of information: 142 or a region where space is falling inwards faster than the speed of light. Properties The no-hair theorem postulates that, once it achieves a stable condition after formation, a black hole has only three independent physical properties: mass, electric charge, and angular momentum; the black hole is otherwise featureless. If the conjecture is true, any two black holes that share the same values for these properties, or parameters, are indistinguishable from one another. The degree to which the conjecture is true for real black holes is currently an unsolved problem. The simplest static black holes have mass but neither electric charge nor angular momentum. According to Birkhoff's theorem, these Schwarzschild black holes are the only vacuum solution that is spherically symmetric. Solutions describing more general black holes also exist. Non-rotating charged black holes are described by the Reissner–Nordström metric, while the Kerr metric describes a non-charged rotating black hole. The most general stationary black hole solution known is the Kerr–Newman metric, which describes a black hole with both charge and angular momentum. The simplest static black holes have mass but neither electric charge nor angular momentum. Contrary to the popular notion of a black hole "sucking in everything" in its surroundings, from far away, the external gravitational field of a black hole is identical to that of any other body of the same mass. While a black hole can theoretically have any positive mass, the charge and angular momentum are constrained by the mass. The total electric charge Q and the total angular momentum J are expected to satisfy the inequality Q 2 4 π ϵ 0 + c 2 J 2 G M 2 ≤ G M 2 {\displaystyle {\frac {Q^{2}}{4\pi \epsilon _{0}}}+{\frac {c^{2}J^{2}}{GM^{2}}}\leq GM^{2}} for a black hole of mass M. Black holes with the maximum possible charge or spin satisfying this inequality are called extremal black holes. Solutions of Einstein's equations that violate this inequality exist, but they do not possess an event horizon. These are so-called naked singularities that can be observed from the outside. Because these singularities make the universe inherently unpredictable, many physicists believe they could not exist. The weak cosmic censorship hypothesis, proposed by Sir Roger Penrose, rules out the formation of such singularities, when they are created through the gravitational collapse of realistic matter. However, this theory has not yet been proven, and some physicists believe that naked singularities could exist. It is also unknown whether black holes could even become extremal, forming naked singularities, since natural processes counteract increasing spin and charge when a black hole becomes near-extremal. The total mass of a black hole can be estimated by analyzing the motion of objects near the black hole, such as stars or gas. All black holes spin, often fast—One supermassive black hole, GRS 1915+105 has been estimated to spin at over 1,000 revolutions per second. The Milky Way's central black hole Sagittarius A* rotates at about 90% of the maximum rate. The spin rate can be inferred from measurements of atomic spectral lines in the X-ray range. As gas near the black hole plunges inward, high energy X-ray emission from electron-positron pairs illuminates the gas further out, appearing red-shifted due to relativistic effects. Depending on the spin of the black hole, this plunge happens at different radii from the hole, with different degrees of redshift. Astronomers can use the gap between the x-ray emission of the outer disk and the redshifted emission from plunging material to determine the spin of the black hole. A newer way to estimate spin is based on the temperature of gasses accreting onto the black hole. The method requires an independent measurement of the black hole mass and inclination angle of the accretion disk followed by computer modeling. Gravitational waves from coalescing binary black holes can also provide the spin of both progenitor black holes and the merged hole, but such events are rare. A spinning black hole has angular momentum. The supermassive black hole in the center of the Messier 87 (M87) galaxy appears to have an angular momentum very close to the maximum theoretical value. That uncharged limit is J ≤ G M 2 c , {\displaystyle J\leq {\frac {GM^{2}}{c}},} allowing definition of a dimensionless spin magnitude such that 0 ≤ c J G M 2 ≤ 1. {\displaystyle 0\leq {\frac {cJ}{GM^{2}}}\leq 1.} Most black holes are believed to have an approximately neutral charge. For example, Michal Zajaček, Arman Tursunov, Andreas Eckart, and Silke Britzen found the electric charge of Sagittarius A* to be at least ten orders of magnitude below the theoretical maximum. A charged black hole repels other like charges just like any other charged object. If a black hole were to become charged, particles with an opposite sign of charge would be pulled in by the extra electromagnetic force, while particles with the same sign of charge would be repelled, neutralizing the black hole. This effect may not be as strong if the black hole is also spinning. The presence of charge can reduce the diameter of the black hole by up to 38%. The charge Q for a nonspinning black hole is bounded by Q ≤ G M , {\displaystyle Q\leq {\sqrt {G}}M,} where G is the gravitational constant and M is the black hole's mass. Classification Black holes can have a wide range of masses. The minimum mass of a black hole formed by stellar gravitational collapse is governed by the maximum mass of a neutron star and is believed to be approximately two-to-four solar masses. However, theoretical primordial black holes, believed to have formed soon after the Big Bang, could be far smaller, with masses as little as 10−5 grams at formation. These very small black holes are sometimes called micro black holes. Black holes formed by stellar collapse are called stellar black holes. Estimates of their maximum mass at formation vary, but generally range from 10 to 100 solar masses, with higher estimates for black holes progenated by low-metallicity stars. The mass of a black hole formed via a supernova has a lower bound: If the progenitor star is too small, the collapse may be stopped by the degeneracy pressure of the star's constituents, allowing the condensation of matter into an exotic denser state. Degeneracy pressure occurs from the Pauli exclusion principle—Particles will resist being in the same place as each other. Smaller progenitor stars, with masses less than about 8 M☉, will be held together by the degeneracy pressure of electrons and will become a white dwarf. For more massive progenitor stars, electron degeneracy pressure is no longer strong enough to resist the force of gravity and the star will be held together by neutron degeneracy pressure, which can occur at much higher densities, forming a neutron star. If the star is still too massive, even neutron degeneracy pressure will not be able to resist the force of gravity and the star will collapse into a black hole.: 5.8 Stellar black holes can also gain mass via accretion of nearby matter, often from a companion object such as a star. Black holes that are larger than stellar black holes but smaller than supermassive black holes are called intermediate-mass black holes, with masses of approximately 102 to 105 solar masses. These black holes seem to be rarer than their stellar and supermassive counterparts, with relatively few candidates having been observed. Physicists have speculated that such black holes may form from collisions in globular and star clusters or at the center of low-mass galaxies. They may also form as the result of mergers of smaller black holes, with several LIGO observations finding merged black holes within the 110-350 solar mass range. The black holes with the largest masses are called supermassive black holes, with masses more than 106 times that of the Sun. These black holes are believed to exist at the centers of almost every large galaxy, including the Milky Way. Some scientists have proposed a subcategory of even larger black holes, called ultramassive black holes, with masses greater than 109-1010 solar masses. Theoretical models predict that the accretion disc that feeds black holes will be unstable once a black hole reaches 50-100 billion times the mass of the Sun, setting a rough upper limit to black hole mass. Structure While black holes are conceptually invisible sinks of all matter and light, in astronomical settings, their enormous gravity alters the motion of surrounding objects and pulls nearby gas inwards at near-light speed, making the area around black holes the brightest objects in the universe. Some black holes have relativistic jets—thin streams of plasma travelling away from the black hole at more than one-tenth of the speed of light. A small faction of the matter falling towards the black hole gets accelerated away along the hole rotation axis. These jets can extend as far as millions of parsecs from the black hole itself. Black holes of any mass can have jets. However, they are typically observed around spinning black holes with strongly-magnetized accretion disks. Relativistic jets were more common in the early universe, when galaxies and their corresponding supermassive black holes were rapidly gaining mass. All black holes with jets also have an accretion disk, but the jets are usually brighter than the disk. Quasars, typically found in other galaxies, are believed to be supermassive black holes with jets; microquasars are believed to be stellar-mass objects with jets, typically observed in the Milky Way. The mechanism of formation of jets is not yet known, but several options have been proposed. One method proposed to fuel these jets is the Blandford-Znajek process, which suggests that the dragging of magnetic field lines by a black hole's rotation could launch jets of matter into space. The Penrose process, which involves extraction of a black hole's rotational energy, has also been proposed as a potential mechanism of jet propulsion. Due to conservation of angular momentum, gas falling into the gravitational well created by a massive object will typically form a disk-like structure around the object.: 242 As the disk's angular momentum is transferred outward due to internal processes, its matter falls farther inward, converting its gravitational energy into heat and releasing a large flux of x-rays. The temperature of these disks can range from thousands to millions of Kelvin, and temperatures can differ throughout a single accretion disk. Accretion disks can also emit in other parts of the electromagnetic spectrum, depending on the disk's turbulence and magnetization and the black hole's mass and angular momentum. Accretion disks can be defined as geometrically thin or geometrically thick. Geometrically thin disks are mostly confined to the black hole's equatorial plane and have a well-defined edge at the innermost stable circular orbit (ISCO), while geometrically thick disks are supported by internal pressure and temperature and can extend inside the ISCO. Disks with high rates of electron scattering and absorption, appearing bright and opaque, are called optically thick; optically thin disks are more translucent and produce fainter images when viewed from afar. Accretion disks of black holes accreting beyond the Eddington limit are often referred to as polish donuts due to their thick, toroidal shape that resembles that of a donut. Quasar accretion disks are expected to usually appear blue in color. The disk for a stellar black hole, on the other hand, would likely look orange, yellow, or red, with its inner regions being the brightest. Theoretical research suggests that the hotter a disk is, the bluer it should be, although this is not always supported by observations of real astronomical objects. Accretion disk colors may also be altered by the Doppler effect, with the part of the disk travelling towards an observer appearing bluer and brighter and the part of the disk travelling away from the observer appearing redder and dimmer. In Newtonian gravity, test particles can stably orbit at arbitrary distances from a central object. In general relativity, however, there exists a smallest possible radius for which a massive particle can orbit stably. Any infinitesimal inward perturbations to this orbit will lead to the particle spiraling into the black hole, and any outward perturbations will, depending on the energy, cause the particle to spiral in, move to a stable orbit further from the black hole, or escape to infinity. This orbit is called the innermost stable circular orbit, or ISCO. The location of the ISCO depends on the spin of the black hole and the spin of the particle itself. In the case of a Schwarzschild black hole (spin zero) and a particle without spin, the location of the ISCO is: r I S C O = 3 r s = 6 G M c 2 , {\displaystyle r_{\rm {ISCO}}=3\,r_{\text{s}}={\frac {6\,GM}{c^{2}}},} where r I S C O {\displaystyle r_{\rm {_{ISCO}}}} is the radius of the ISCO, r s {\displaystyle r_{\text{s}}} is the Schwarzschild radius of the black hole, G {\displaystyle G} is the gravitational constant, and c {\displaystyle c} is the speed of light. The radius of this orbit changes slightly based on particle spin. For charged black holes, the ISCO moves inwards. For spinning black holes, the ISCO is moved inwards for particles orbiting in the same direction that the black hole is spinning (prograde) and outwards for particles orbiting in the opposite direction (retrograde). For example, the ISCO for a particle orbiting retrograde can be as far out as about 9 r s {\displaystyle 9r_{\text{s}}} , while the ISCO for a particle orbiting prograde can be as close as at the event horizon itself. The photon sphere is a spherical boundary for which photons moving on tangents to that sphere are bent completely around the black hole, possibly orbiting multiple times. Light rays with impact parameters less than the radius of the photon sphere enter the black hole. For Schwarzschild black holes, the photon sphere has a radius 1.5 times the Schwarzschild radius; the radius for non-Schwarzschild black holes is at least 1.5 times the radius of the event horizon. When viewed from a great distance, the photon sphere creates an observable black hole shadow. Since no light emerges from within the black hole, this shadow is the limit for possible observations.: 152 The shadow of colliding black holes should have characteristic warped shapes, allowing scientists to detect black holes that are about to merge. While light can still escape from the photon sphere, any light that crosses the photon sphere on an inbound trajectory will be captured by the black hole. Therefore, any light that reaches an outside observer from the photon sphere must have been emitted by objects between the photon sphere and the event horizon. Light emitted towards the photon sphere may also curve around the black hole and return to the emitter. For a rotating, uncharged black hole, the radius of the photon sphere depends on the spin parameter and whether the photon is orbiting prograde or retrograde. For a photon orbiting prograde, the photon sphere will be 1-3 Schwarzschild radii from the center of the black hole, while for a photon orbiting retrograde, the photon sphere will be between 3-5 Schwarzschild radii from the center of the black hole. The exact location of the photon sphere depends on the magnitude of the black hole's rotation. For a charged, nonrotating black hole, there will only be one photon sphere, and the radius of the photon sphere will decrease for increasing black hole charge. For non-extremal, charged, rotating black holes, there will always be two photon spheres, with the exact radii depending on the parameters of the black hole. Near a rotating black hole, spacetime rotates similar to a vortex. The rotating spacetime will drag any matter and light into rotation around the spinning black hole. This effect of general relativity, called frame dragging, gets stronger closer to the spinning mass. The region of spacetime in which it is impossible to stay still is called the ergosphere. The ergosphere of a black hole is a volume bounded by the black hole's event horizon and the ergosurface, which coincides with the event horizon at the poles but bulges out from it around the equator. Matter and radiation can escape from the ergosphere. Through the Penrose process, objects can emerge from the ergosphere with more energy than they entered with. The extra energy is taken from the rotational energy of the black hole, slowing down the rotation of the black hole.: 268 A variation of the Penrose process in the presence of strong magnetic fields, the Blandford–Znajek process, is considered a likely mechanism for the enormous luminosity and relativistic jets of quasars and other active galactic nuclei. The observable region of spacetime around a black hole closest to its event horizon is called the plunging region. In this area it is no longer possible for free falling matter to follow circular orbits or stop a final descent into the black hole. Instead, it will rapidly plunge toward the black hole at close to the speed of light, growing increasingly hot and producing a characteristic, detectable thermal emission. However, light and radiation emitted from this region can still escape from the black hole's gravitational pull. For a nonspinning, uncharged black hole, the radius of the event horizon, or Schwarzschild radius, is proportional to the mass, M, through r s = 2 G M c 2 ≈ 2.95 M M ⊙ k m , {\displaystyle r_{\mathrm {s} }={\frac {2GM}{c^{2}}}\approx 2.95\,{\frac {M}{M_{\odot }}}~\mathrm {km,} } where rs is the Schwarzschild radius and M☉ is the mass of the Sun.: 124 For a black hole with nonzero spin or electric charge, the radius is smaller,[Note 1] until an extremal black hole could have an event horizon close to r + = G M c 2 , {\displaystyle r_{\mathrm {+} }={\frac {GM}{c^{2}}},} half the radius of a nonspinning, uncharged black hole of the same mass. Since the volume within the Schwarzschild radius increase with the cube of the radius, average density of a black hole inside its Schwarzschild radius is inversely proportional to the square of its mass: supermassive black holes are much less dense than stellar black holes. The average density of a 108 M☉ black hole is comparable to that of water. The defining feature of a black hole is the existence of an event horizon, a boundary in spacetime through which matter and light can pass only inward towards the center of the black hole. Nothing, not even light, can escape from inside the event horizon. The event horizon is referred to as such because if an event occurs within the boundary, information from that event cannot reach or affect an outside observer, making it impossible to determine whether such an event occurred.: 179 For non-rotating black holes, the geometry of the event horizon is precisely spherical, while for rotating black holes, the event horizon is oblate. To a distant observer, a clock near a black hole would appear to tick more slowly than one further from the black hole.: 217 This effect, known as gravitational time dilation, would also cause an object falling into a black hole to appear to slow as it approached the event horizon, never quite reaching the horizon from the perspective of an outside observer.: 218 All processes on this object would appear to slow down, and any light emitted by the object to appear redder and dimmer, an effect known as gravitational redshift. An object falling from half of a Schwarzschild radius above the event horizon would fade away until it could no longer be seen, disappearing from view within one hundredth of a second. It would also appear to flatten onto the black hole, joining all other material that had ever fallen into the hole. On the other hand, an observer falling into a black hole would not notice any of these effects as they cross the event horizon. Their own clocks appear to them to tick normally, and they cross the event horizon after a finite time without noting any singular behaviour. In general relativity, it is impossible to determine the location of the event horizon from local observations, due to Einstein's equivalence principle.: 222 Black holes that are rotating and/or charged have an inner horizon, often called the Cauchy horizon, inside of the black hole. The inner horizon is divided up into two segments: an ingoing section and an outgoing section. At the ingoing section of the Cauchy horizon, radiation and matter that fall into the black hole would build up at the horizon, causing the curvature of spacetime to go to infinity. This would cause an observer falling in to experience tidal forces. This phenomenon is often called mass inflation, since it is associated with a parameter dictating the black hole's internal mass growing exponentially, and the buildup of tidal forces is called the mass-inflation singularity or Cauchy horizon singularity. Some physicists have argued that in realistic black holes, accretion and Hawking radiation would stop mass inflation from occurring. At the outgoing section of the inner horizon, infalling radiation would backscatter off of the black hole's spacetime curvature and travel outward, building up at the outgoing Cauchy horizon. This would cause an infalling observer to experience a gravitational shock wave and tidal forces as the spacetime curvature at the horizon grew to infinity. This buildup of tidal forces is called the shock singularity. Both of these singularities are weak, meaning that an object crossing them would only be deformed a finite amount by tidal forces, even though the spacetime curvature would still be infinite at the singularity. This is as opposed to a strong singularity, where an object hitting the singularity would be stretched and squeezed by an infinite amount. They are also null singularities, meaning that a photon could travel parallel to the them without ever being intercepted. Ignoring quantum effects, every black hole has a singularity inside, points where the curvature of spacetime becomes infinite, and geodesics terminate within a finite proper time.: 205 For a non-rotating black hole, this region takes the shape of a single point; for a rotating black hole it is smeared out to form a ring singularity that lies in the plane of rotation.: 264 In both cases, the singular region has zero volume. All of the mass of the black hole ends up in the singularity.: 252 Since the singularity has nonzero mass in an infinitely small space, it can be thought of as having infinite density. Observers falling into a Schwarzschild black hole (i.e., non-rotating and not charged) cannot avoid being carried into the singularity once they cross the event horizon. As they fall further into the black hole, they will be torn apart by the growing tidal forces in a process sometimes referred to as spaghettification or the noodle effect. Eventually, they will reach the singularity and be crushed into an infinitely small point.: 182 However any perturbations, such as those caused by matter or radiation falling in, would cause space to oscillate chaotically near the singularity. Any matter falling in would experience intense tidal forces rapidly changing in direction, all while being compressed into an increasingly small volume. Alternative forms of general relativity, including addition of some quatum effects, can lead to regular, or nonsingular, black holes without singularities. For example, the fuzzball model, based on string theory, states that black holes are actually made up of quantum microstates and need not have a singularity or an event horizon. The theory of loop quantum gravity proposes that the curvature and density at the center of a black hole is large, but not infinite. Formation Black holes are formed by gravitational collapse of massive stars, either by direct collapse or during a supernova explosion in a process called fallback. Black holes can result from the merger of two neutron stars or a neutron star and a black hole. Other more speculative mechanisms include primordial black holes created from density fluctuations in the early universe, the collapse of dark stars, a hypothetical object powered by annihilation of dark matter, or from hypothetical self-interacting dark matter. Gravitational collapse occurs when an object's internal pressure is insufficient to resist the object's own gravity. At the end of a star's life, it will run out of hydrogen to fuse, and will start fusing more and more massive elements, until it gets to iron. Since the fusion of elements heavier than iron would require more energy than it would release, nuclear fusion ceases. If the iron core of the star is too massive, the star will no longer be able to support itself and will undergo gravitational collapse. While most of the energy released during gravitational collapse is emitted very quickly, an outside observer does not actually see the end of this process. Even though the collapse takes a finite amount of time from the reference frame of infalling matter, a distant observer would see the infalling material slow and halt just above the event horizon, due to gravitational time dilation. Light from the collapsing material takes longer and longer to reach the observer, with the delay growing to infinity as the emitting material reaches the event horizon. Thus the external observer never sees the formation of the event horizon; instead, the collapsing material seems to become dimmer and increasingly red-shifted, eventually fading away. Observations of quasars at redshift z ∼ 7 {\displaystyle z\sim 7} , less than a billion years after the Big Bang, has led to investigations of other ways to form black holes. The accretion process to build supermassive black holes has a limiting rate of mass accumulation and a billion years is not enough time to reach quasar status. One suggestion is direct collapse of nearly pure hydrogen gas (low metalicity) clouds characteristic of the young universe, forming a supermassive star which collapses into a black hole. It has been suggested that seed black holes with typical masses of ~105 M☉ could have formed in this way which then could grow to ~109 M☉. However, the very large amount of gas required for direct collapse is not typically stable to fragmentation to form multiple stars. Thus another approach suggests massive star formation followed by collisions that seed massive black holes which ultimately merge to create a quasar.: 85 A neutron star in a common envelope with a regular star can accrete sufficient material to collapse to a black hole or two neutron stars can merge. These avenues for the formation of black holes are considered relatively rare. In the current epoch of the universe, conditions needed to form black holes are rare and are mostly only found in stars. However, in the early universe, conditions may have allowed for black hole formations via other means. Fluctuations of spacetime soon after the Big Bang may have formed areas that were denser then their surroundings. Initially, these regions would not have been compact enough to form a black hole, but eventually, the curvature of spacetime in the regions become large enough to cause them to collapse into a black hole. Different models for the early universe vary widely in their predictions of the scale of these fluctuations. Various models predict the creation of primordial black holes ranging from a Planck mass (~2.2×10−8 kg) to hundreds of thousands of solar masses. Primordial black holes with masses less than 1015 g would have evaporated by now due to Hawking radiation. Despite the early universe being extremely dense, it did not re-collapse into a black hole during the Big Bang, since the universe was expanding rapidly and did not have the gravitational differential necessary for black hole formation. Models for the gravitational collapse of objects of relatively constant size, such as stars, do not necessarily apply in the same way to rapidly expanding space such as the Big Bang. In principle, black holes could be formed in high-energy particle collisions that achieve sufficient density, although no such events have been detected. These hypothetical micro black holes, which could form from the collision of cosmic rays and Earth's atmosphere or in particle accelerators like the Large Hadron Collider, would not be able to aggregate additional mass. Instead, they would evaporate in about 10−25 seconds, posing no threat to the Earth. Evolution Black holes can also merge with other objects such as stars or even other black holes. This is thought to have been important, especially in the early growth of supermassive black holes, which could have formed from the aggregation of many smaller objects. The process has also been proposed as the origin of some intermediate-mass black holes. Mergers of supermassive black holes may take a long time: As a binary of supermassive black holes approach each other, most nearby stars are ejected, leaving little for the remaining black holes to gravitationally interact with that would allow them to get closer to each other. This phenomenon has been called the final parsec problem, as the distance at which this happens is usually around one parsec. When a black hole accretes matter, the gas in the inner accretion disk orbits at very high speeds because of its proximity to the black hole. The resulting friction heats the inner disk to temperatures at which it emits vast amounts of electromagnetic radiation (mainly X-rays) detectable by telescopes. By the time the matter of the disk reaches the ISCO, between 5.7% and 42% of its mass will have been converted to energy, depending on the black hole's spin. About 90% of this energy is released within about 20 black hole radii. In many cases, accretion disks are accompanied by relativistic jets that are emitted along the black hole's poles, which carry away much of the energy. The mechanism for the creation of these jets is currently not well understood, in part due to insufficient data. Many of the universe's most energetic phenomena have been attributed to the accretion of matter on black holes. Active galactic nuclei and quasars are believed to be the accretion disks of supermassive black holes. X-ray binaries are generally accepted to be binary systems in which one of the two objects is a compact object accreting matter from its companion. Ultraluminous X-ray sources may be the accretion disks of intermediate-mass black holes. At a certain rate of accretion, the outward radiation pressure will become as strong as the inward gravitational force, and the black hole should unable to accrete any faster. This limit is called the Eddington limit. However, many black holes accrete beyond this rate due to their non-spherical geometry or instabilities in the accretion disk. Accretion beyond the limit is called Super-Eddington accretion and may have been commonplace in the early universe. Stars have been observed to get torn apart by tidal forces in the immediate vicinity of supermassive black holes in galaxy nuclei, in what is known as a tidal disruption event (TDE). Some of the material from the disrupted star forms an accretion disk around the black hole, which emits observable electromagnetic radiation. The correlation between the masses of supermassive black holes in the centres of galaxies with the velocity dispersion and mass of stars in their host bulges suggests that the formation of galaxies and the formation of their central black holes are related. Black hole winds from rapid accretion, particularly when the galaxy itself is still accreting matter, can compress gas nearby, accelerating star formation. However, if the winds become too strong, the black hole may blow nearly all of the gas out of the galaxy, quenching star formation. Black hole jets may also energize nearby cavities of plasma and eject low-entropy gas from out of the galactic core, causing gas in galactic centers to be hotter than expected. If Hawking's theory of black hole radiation is correct, then black holes are expected to shrink and evaporate over time as they lose mass by the emission of photons and other particles. The temperature of this thermal spectrum (Hawking temperature) is proportional to the surface gravity of the black hole, which is inversely proportional to the mass. Hence, large black holes emit less radiation than small black holes.: Ch. 9.6 A stellar black hole of 1 M☉ has a Hawking temperature of 62 nanokelvins. This is far less than the 2.7 K temperature of the cosmic microwave background radiation. Stellar-mass or larger black holes receive more mass from the cosmic microwave background than they emit through Hawking radiation and thus will grow instead of shrinking. To have a Hawking temperature larger than 2.7 K (and be able to evaporate), a black hole would need a mass less than the Moon. Such a black hole would have a diameter of less than a tenth of a millimetre. The Hawking radiation for an astrophysical black hole is predicted to be very weak and would thus be exceedingly difficult to detect from Earth. A possible exception is the burst of gamma rays emitted in the last stage of the evaporation of primordial black holes. Searches for such flashes have proven unsuccessful and provide stringent limits on the possibility of existence of low mass primordial black holes, with modern research predicting that primordial black holes must make up less than a fraction of 10−7 of the universe's total mass. NASA's Fermi Gamma-ray Space Telescope, launched in 2008, has searched for these flashes, but has not yet found any. The properties of a black hole are constrained and interrelated by the theories that predict these properties. When based on general relativity, these relationships are called the laws of black hole mechanics. For a black hole that is not still forming or accreting matter, the zeroth law of black hole mechanics states the black hole's surface gravity is constant across the event horizon. The first law relates changes in the black hole's surface area, angular momentum, and charge to changes in its energy. The second law says the surface area of a black hole never decreases on its own. Finally, the third law says that the surface gravity of a black hole is never zero. These laws are mathematical analogs of the laws of thermodynamics. They are not equivalent, however, because, according to general relativity without quantum mechanics, a black hole can never emit radiation, and thus its temperature must always be zero.: 11 Quantum mechanics predicts that a black hole will continuously emit thermal Hawking radiation, and therefore must always have a nonzero temperature. It also predicts that all black holes have entropy which scales with their surface area. When quantum mechanics is accounted for, the laws of black hole mechanics become equivalent to the classical laws of thermodynamics. However, these conclusions are derived without a complete theory of quantum gravity, although many potential theories do predict black holes having entropy and temperature. Thus, the true quantum nature of black hole thermodynamics continues to be debated.: 29 Observational evidence Millions of black holes with around 30 solar masses derived from stellar collapse are expected to exist in the Milky Way. Even a dwarf galaxy like Draco should have hundreds. Only a few of these have been detected. By nature, black holes do not themselves emit any electromagnetic radiation other than the hypothetical Hawking radiation, so astrophysicists searching for black holes must generally rely on indirect observations. The defining characteristic of a black hole is its event horizon. The horizon itself cannot be imaged, so all other possible explanations for these indirect observations must be considered and eliminated before concluding that a black hole has been observed.: 11 The Event Horizon Telescope (EHT) is a global system of radio telescopes capable of directly observing a black hole shadow. The angular resolution of a telescope is based on its aperture and the wavelengths it is observing. Because the angular diameters of Sagittarius A* and Messier 87* in the sky are very small, a single telescope would need to be about the size of the Earth to clearly distinguish their horizons using radio wavelengths. By combining data from several different radio telescopes around the world, the Event Horizon Telescope creates an effective aperture the diameter size of the Earth. The EHT team used imaging algorithms to compute the most probable image from the data in its observations of Sagittarius A* and M87*. Gravitational-wave interferometry can be used to detect merging black holes and other compact objects. In this method, a laser beam is split down two long arms of a tunnel. The laser beams reflect off of mirrors in the tunnels and converge at the intersection of the arms, cancelling each other out. However, when a gravitational wave passes, it warps spacetime, changing the lengths of the arms themselves. Since each laser beam is now travelling a slightly different distance, they do not cancel out and produce a recognizable signal. Analysis of the signal can give scientists information about what caused the gravitational waves. Since gravitational waves are very weak, gravitational-wave observatories such as LIGO must have arms several kilometers long and carefully control for noise from Earth to be able to detect these gravitational waves. Since the first measurements in 2016, multiple gravitational waves from black holes have been detected and analyzed. The proper motions of stars near the centre of the Milky Way provide strong observational evidence that these stars are orbiting a supermassive black hole. Since 1995, astronomers have tracked the motions of 90 stars orbiting an invisible object coincident with the radio source Sagittarius A*. In 1998, by fitting the motions of the stars to Keplerian orbits, the astronomers were able to infer that Sagittarius A* must be a 2.6×106 M☉ object must be contained within a radius of 0.02 light-years. Since then, one of the stars—called S2—has completed a full orbit. From the orbital data, astronomers were able to refine the calculations of the mass of Sagittarius A* to 4.3×106 M☉, with a radius of less than 0.002 light-years. This upper limit radius is larger than the Schwarzschild radius for the estimated mass, so the combination does not prove Sagittarius A* is a black hole. Nevertheless, these observations strongly suggest that the central object is a supermassive black hole as there are no other plausible scenarios for confining so much invisible mass into such a small volume. Additionally, there is some observational evidence that this object might possess an event horizon, a feature unique to black holes. The Event Horizon Telescope image of Sagittarius A*, released in 2022, provided further confirmation that it is indeed a black hole. X-ray binaries are binary systems that emit a majority of their radiation in the X-ray part of the electromagnetic spectrum. These X-ray emissions result when a compact object accretes matter from an ordinary star. The presence of an ordinary star in such a system provides an opportunity for studying the central object and to determine if it might be a black hole. By measuring the orbital period of the binary, the distance to the binary from Earth, and the mass of the companion star, scientists can estimate the mass of the compact object. The Tolman-Oppenheimer-Volkoff limit (TOV limit) dictates the largest mass a nonrotating neutron star can be, and is estimated to be about two solar masses. While a rotating neutron star can be slightly more massive, if the compact object is much more massive than the TOV limit, it cannot be a neutron star and is generally expected to be a black hole. The first strong candidate for a black hole, Cygnus X-1, was discovered in this way by Charles Thomas Bolton, Louise Webster, and Paul Murdin in 1972. Observations of rotation broadening of the optical star reported in 1986 lead to a compact object mass estimate of 16 solar masses, with 7 solar masses as the lower bound. In 2011, this estimate was updated to 14.1±1.0 M☉ for the black hole and 19.2±1.9 M☉ for the optical stellar companion. X-ray binaries can be categorized as either low-mass or high-mass; This classification is based on the mass of the companion star, not the compact object itself. In a class of X-ray binaries called soft X-ray transients, the companion star is of relatively low mass, allowing for more accurate estimates of the black hole mass. These systems actively emit X-rays for only several months once every 10–50 years. During the period of low X-ray emission, called quiescence, the accretion disk is extremely faint, allowing detailed observation of the companion star. Numerous black hole candidates have been measured by this method. Black holes are also sometimes found in binaries with other compact objects, such as white dwarfs, neutron stars, and other black holes. The centre of nearly every galaxy contains a supermassive black hole. The close observational correlation between the mass of this hole and the velocity dispersion of the host galaxy's bulge, known as the M–sigma relation, strongly suggests a connection between the formation of the black hole and that of the galaxy itself. Astronomers use the term active galaxy to describe galaxies with unusual characteristics, such as unusual spectral line emission and very strong radio emission. Theoretical and observational studies have shown that the high levels of activity in the centers of these galaxies, regions called active galactic nuclei (AGN), may be explained by accretion onto supermassive black holes. These AGN consist of a central black hole that may be millions or billions of times more massive than the Sun, a disk of interstellar gas and dust called an accretion disk, and two jets perpendicular to the accretion disk. Although supermassive black holes are expected to be found in most AGN, only some galaxies' nuclei have been more carefully studied in attempts to both identify and measure the actual masses of the central supermassive black hole candidates. Some of the most notable galaxies with supermassive black hole candidates include the Andromeda Galaxy, Messier 32, Messier 87, the Sombrero Galaxy, and the Milky Way itself. Another way black holes can be detected is through observation of effects caused by their strong gravitational field. One such effect is gravitational lensing: The deformation of spacetime around a massive object causes light rays to be deflected, making objects behind them appear distorted. When the lensing object is a black hole, this effect can be strong enough to create multiple images of a star or other luminous source. However, the distance between the lensed images may be too small for contemporary telescopes to resolve—this phenomenon is called microlensing. Instead of seeing two images of a lensed star, astronomers see the star brighten slightly as the black hole moves towards the line of sight between the star and Earth and then return to its normal luminosity as the black hole moves away. The turn of the millennium saw the first 3 candidate detections of black holes in this way, and in January 2022, astronomers reported the first confirmed detection of a microlensing event from an isolated black hole. This was also the first determination of an isolated black hole mass, 7.1±1.3 M☉. Alternatives While there is a strong case for supermassive black holes, the model for stellar-mass black holes assumes of an upper limit for the mass of a neutron star: objects observed to have more mass are assumed to be black holes. However, the properties of extremely dense matter are poorly understood. New exotic phases of matter could allow other kinds of massive objects. Quark stars would be made up of quark matter and supported by quark degeneracy pressure, a form of degeneracy pressure even stronger than neutron degeneracy pressure. This would halt gravitational collapse at a higher mass than for a neutron star. Even stronger stars called electroweak stars would convert quarks in their cores into leptons, providing additional pressure to stop the star from collapsing. If, as some extensions of the Standard Model posit, quarks and leptons are made up of the even-smaller fundamental particles called preons, a very compact star could be supported by preon degeneracy pressure. While none of these hypothetical models can explain all of the observations of stellar black hole candidates, a Q star is the only alternative which could significantly exceed the mass limit for neutron stars and thus provide an alternative for supermassive black holes.: 12 A few theoretical objects have been conjectured to match observations of astronomical black hole candidates identically or near-identically, but which function via a different mechanism. A dark energy star would convert infalling matter into vacuum energy; This vacuum energy would be much larger than the vacuum energy of outside space, exerting outwards pressure and preventing a singularity from forming. A black star would be gravitationally collapsing slowly enough that quantum effects would keep it just on the cusp of fully collapsing into a black hole. A gravastar would consist of a very thin shell and a dark-energy interior providing outward pressure to stop the collapse into a black hole or formation of a singularity; It could even have another gravastar inside, called a 'nestar'. Open questions According to the no-hair theorem, a black hole is defined by only three parameters: its mass, charge, and angular momentum. This seems to mean that all other information about the matter that went into forming the black hole is lost, as there is no way to determine anything about the black hole from outside other than those three parameters. When black holes were thought to persist forever, this information loss was not problematic, as the information can be thought of as existing inside the black hole. However, black holes slowly evaporate by emitting Hawking radiation. This radiation does not appear to carry any additional information about the matter that formed the black hole, meaning that this information is seemingly gone forever. This is called the black hole information paradox. Theoretical studies analyzing the paradox have led to both further paradoxes and new ideas about the intersection of quantum mechanics and general relativity. While there is no consensus on the resolution of the paradox, work on the problem is expected to be important for a theory of quantum gravity.: 126 Observations of faraway galaxies have found that ultraluminous quasars, powered by supermassive black holes, existed in the early universe as far as redshift z ≥ 7 {\displaystyle z\geq 7} . These black holes have been assumed to be the products of the gravitational collapse of large population III stars. However, these stellar remnants were not massive enough to produce the quasars observed at early times without accreting beyond the Eddington limit, the theoretical maximum rate of black hole accretion. Physicists have suggested a variety of different mechanisms by which these supermassive black holes may have formed. It has been proposed that smaller black holes may have also undergone mergers to produce the observed supermassive black holes. It is also possible that they were seeded by direct-collapse black holes, in which a large cloud of hot gas avoids fragmentation that would lead to multiple stars, due to low angular momentum or heating from a nearby galaxy. Given the right circumstances, a single supermassive star forms and collapses directly into a black hole without undergoing typical stellar evolution. Additionally, these supermassive black holes in the early universe may be high-mass primordial black holes, which could have accreted further matter in the centers of galaxies. Finally, certain mechanisms allow black holes to grow faster than the theoretical Eddington limit, such as dense gas in the accretion disk limiting outward radiation pressure that prevents the black hole from accreting. However, the formation of bipolar jets prevent super-Eddington rates. In fiction Black holes have been portrayed in science fiction in a variety of ways. Even before the advent of the term itself, objects with characteristics of black holes appeared in stories such as the 1928 novel The Skylark of Space with its "black Sun" and the "hole in space" in the 1935 short story Starship Invincible. As black holes grew to public recognition in the 1960s and 1970s, they began to be featured in films as well as novels, such as Disney's The Black Hole. Black holes have also been used in works of the 21st century, such as Christopher Nolan's science fiction epic Interstellar. Authors and screenwriters have exploited the relativistic effects of black holes, particularly gravitational time dilation. For example, Interstellar features a black hole planet with a time dilation factor of over 60,000:1, while the 1977 novel Gateway depicts a spaceship approaching but never crossing the event horizon of a black hole from the perspective of an outside observer due to time dilation effects. Black holes have also been appropriated as wormholes or other methods of faster-than-light travel, such as in the 1974 novel The Forever War, where a network of black holes is used for interstellar travel. Additionally, black holes can feature as hazards to spacefarers and planets: A black hole threatens a deep-space outpost in 1978 short story The Black Hole Passes, and a binary black hole dangerously alters the orbit of a planet in the 2018 Netflix reboot of Lost in Space. Notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Federally_recognized_tribe] | [TOKENS: 5482] |
Contents Federally recognized tribe A federally recognized tribe is a Native American tribe recognized by the United States Bureau of Indian Affairs as holding a government-to-government relationship with the US federal government. In the United States, the Native American tribe is a fundamental unit of sovereign tribal government. As the Department of the Interior explains, "federally recognized tribes are recognized as possessing certain inherent rights of self-government (i.e., tribal sovereignty)...." The constitution grants to the U.S. Congress the right to interact with tribes. In the 1831 Supreme Court of the United States case Cherokee Nation v. Georgia Chief Justice of the United States John Marshall wrote that a Native American government is a "domestic dependent nation'" whose relationship to the United States is like that of a "ward to its guardian". The case was a landmark decision which led to the United States recognizing over 574 federally recognized tribal governments and 326 Indian reservations which are legally classified as domestic dependent nations with tribal sovereignty rights. The Supreme Court held in United States v. Sandoval "that Congress may bring a community or body of people within range of this power by arbitrarily calling them an Indian tribe, but only that in respect of distinctly Indian communities the questions whether, to what extent, and for what time they shall be recognized and dealt with as dependent tribes" (at 46). Federal tribal recognition grants to tribes the right to certain benefits, and is largely administered by the Bureau of Indian Affairs (BIA). While trying to determine which groups were eligible for federal recognition in the 1970s, government officials became aware of the need for consistent procedures. To illustrate, several federally unrecognized tribes encountered obstacles in bringing land claims; United States v. Washington (1974) was a court case that affirmed the fishing treaty rights of Washington tribes; and other tribes demanded that the U.S. government recognize aboriginal titles. All the above culminated in the Indian Self-Determination and Education Assistance Act of 1975, which legitimized tribal entities by partially restoring Native American self-determination. Native American sovereignty and the Constitution The United States Constitution mentions Native American tribes three times: These constitutional provisions, and subsequent interpretations by the Supreme Court (see below), are today often summarized in three principles of U.S. Indian law: History From the beginning of the European colonization of the Americas, Europeans often removed Indigenous peoples from their homelands. The means varied, including treaties made under considerable duress, forceful ejection, violence, and in a few cases voluntary moves based on mutual agreement. The removal caused many problems such as tribes losing the means of livelihood by being restricted to a defined area, poor quality of land for agriculture, and hostility between tribes. Early English settlers in the Americas entered into treaties with Native American tribes as a method of legitimizing their conquests in the face of competing claims by the Spanish Empire and violent resistance from the tribes themselves. Applying the term "treaty" to such unequal relationships may seem paradoxical from a modern perspective because in modern English, the word "treaty" usually connotes an agreement between two states of theoretically equal sovereignty, not an agreement between conquered people and a conqueror. However, in premodern times, it was common for European princes to routinely enter into unequal treaties with lesser dependent powers. The first reservation was established by the Treaty of Easton on August 29, 1758, between the chiefs of thirteen Native American nations, representing tribes of the Iroquois, Lenape (Delaware), and Shawnee, and the colonial governments of New Jersey and Pennsylvania. Located in southern New Jersey, it was called Brotherton Indian Reservation and also Edgepillock or Edgepelick. The area was 3,284 acres (13.29 km2). Today it is called Indian Mills in Shamong Township. In 1764 the British government's Board of Trade proposed the "Plan for the Future Management of Indian Affairs". Although never adopted formally, the plan established the British government's expectation that land would only be bought by colonial governments, not individuals, and that land would only be purchased at public meetings. Additionally, this plan dictated that the Indians would be properly consulted when ascertaining and defining the boundaries of colonial settlement. The private contracts that once characterized the sale of Indian land to various individuals and groups—from farmers to towns—were replaced by treaties between sovereigns. This protocol was adopted by the United States Government after the American Revolution. On March 11, 1824, U.S. Vice President John C. Calhoun founded the Office of Indian Affairs (now the Bureau of Indian Affairs) as a division of the United States Department of War (now the United States Department of Defense), to solve the land problem with 38 treaties with American Indian tribes. The Marshall Trilogy is a set of three Supreme Court decisions in the early nineteenth century affirming the legal and political standing of Indian nations. Marshall's phrasing "laid the groundwork for future protection of tribal sovereignty by Marshall and his immediate successors, but the characterization also created an opportunity for much later courts to discover limits to tribal sovereignty inherent in domestic dependent status. Marshall's reference to tribes as 'wards' was to have an equally mixed history". Indian Treaties, and Laws and Regulations Relating to Indian Affairs (1825) was a document signed by President Andrew Jackson in which he states that "we have placed the land reserves in a better state for the benefit of society" with approval of Indigenous reservations before 1850. The letter is signed by Isaac Shelby and Jackson. It discusses several regulations regarding the Native Americans and the approval of Indigenous segregation and the reservation system. President Martin Van Buren negotiated a treaty with the Saginaw Chippewas in 1837 to build a lighthouse. The President of the United States of America was directly involved in the creation of new treaties regarding Indian Reservations before 1850. Van Buren stated that indigenous reservations are "all their reserves of land in the state of Michigan, on the principle of said reserves being sold at the public land offices for their benefit and the actual proceeds being paid to them." The agreement dictated that the indigenous tribe sell their land to build a lighthouse. A treaty signed by John Forsyth, the Secretary of State on behalf of Van Buren, also dictates where indigenous peoples must live in terms of the reservation system in America between the Oneida People in 1838. This treaty allows the indigenous peoples five years on a specific reserve "the west shores of Saganaw bay". The creation of reservations for indigenous people of America could be as little as a five-year approval before 1850. Article two of the treaty claims "the reserves on the river Angrais and at Rifle river, of which said Indians are to have the usufruct and occupancy for five years." Indigenous people had restraints pushed on them by the five-year allowance. Scholarly author Buck Woodard used executive papers from Governor William H. Cabell in his article, "Indian Land sales and allotment in Antebellum Virginia" to discuss Indigenous reservations in America before 1705, specifically in Virginia. He claims "the colonial government again recognized the Nottoway's land rights by treaty in 1713, at the conclusion of the Tuscaro War." The indigenous peoples of America had land treaty agreements as early as 1713. The American Indigenous Reservation system started with "the Royal Proclamation of 1763, where Great Britain set aside an enormous resource for Indians in the territory of the present United States." The United States put forward another act when "Congress passed the Indian Removal Act in 1830". A third act pushed through was "the federal government relocated "portions of [the] 'Five Civilized Tribes' from the southeastern states in the Non-Intercourse Act of 1834." All three of these laws set into motion the Indigenous Reservation system in the United States of America, resulting in the forceful removal of Indigenous peoples into specific land Reservations. Scholarly author James Oberly discusses "The Treaty of 1831 between the Menominee Nation and the United States" in his article, "Decision on Duck Creek: Two Green Bay Reservations and Their Boundaries, 1816–1996", showing yet another treaty regarding Indigenous Reservations before 1850. There is a conflict between the Menomee Nation and the State of Wisconsin and "the 1831 Menomee Treaty … ran the boundary between the lands of the Oneida, known in the Treaty as the "New York Indians". This Treaty from 1831 is the cause of conflicts and is disputed because the land was good hunting grounds. The Trade and Intercourse Act of 1834 says "In the 1834 Indian Trade and Intercourse Act, the United States defined the boundaries of Indian County." Also, "For Unrau, Indigenous Country is less on Indigenous homeland and more a place where the U.S. removed Indians from east of the Mississippi River and applied unique laws." The United States of America applied laws on Indigenous Reservations depending on where they were located like the Mississippi River. This act came too, because "the federal government began to compress Indigenous lands because it needed to send troops to Texas during the Mexican-American War and protect American immigration traveling to Oregon and California." The Federal Government of America had their own needs and desires for Indigenous Land Reservations. He says, "the reconnaissance of explorers and other American officials understood that Indigenous Country possessed good land, bountiful game, and potential mineral resources." The American Government claimed Indigenous land for their own benefits with these creations of Indigenous Land Reservations . States such as Texas had their own policy when it came to Indian Reservations in America before 1850. Scholarly author George D. Harmon discusses Texas' own reservation system which "Prior to 1845, Texas had inaugurated and pursued her own Indian Policy of the U.S." Texas was one of the States before 1850 that chose to create their own reservation system as seen in Harmon's article, "The United States Indian Policy in Texas, 1845–1860." The State of "Texas had given only a few hundred acres of land in 1840, for the purpose of colonization". However, "In March 1847, … [a] special agent [was sent] to Texas to manage the Indian affairs in the State until Congress should take some definite and final action." The United States of America allowed its states to make up their own treaties such as this one in Texas for the purpose of colonization. The passage of the Indian Removal Act of 1830 marked the systematization of a U.S. federal government policy of moving Native populations away from European-populated areas, whether forcibly or voluntarily. One example was the Five Civilized Tribes, who were removed from their historical homelands in the Southeastern United States and moved to Indian Territory, in a forced mass migration that came to be known as the Trail of Tears. Some of the lands these tribes were given to inhabit following the removals eventually became Indian reservations. In 1851, the United States Congress passed the Indian Appropriations Act which authorized the creation of Indian reservations in Indian Territory (which became Oklahoma). Relations between white settlers and Natives had grown increasingly worse as the settlers encroached on territory and natural resources in the West. In 1868, President Ulysses S. Grant pursued a "Peace Policy" as an attempt to avoid violence. The policy included a reorganization of the Indian Service, with the goal of relocating various tribes from their ancestral homes to parcels of lands established specifically for their inhabitation. The policy called for the replacement of government officials by religious men, nominated by churches, to oversee the Indian agencies on reservations in order to teach Christianity to the Native American tribes. The Quakers were especially active in this policy on reservations. The policy was controversial from the start. Reservations were generally established by executive order. In many cases, white settlers objected to the size of land parcels, which were subsequently reduced. A report submitted to Congress in 1868 found widespread corruption among the federal Native American agencies and generally poor conditions among the relocated tribes. The Indian Appropriations Act of 1871 had two significant sections. First, the Act ended United States recognition of additional Native American tribes or independent nations and prohibited additional treaties. Thus, it required the federal government no longer interact with the various tribes through treaties, but rather through statutes: That hereafter no Indian nation or tribe within the territory of the United States shall be acknowledged or recognized as an independent nation, tribe, or power with whom the United States may contract by treaty: Provided, further, that nothing herein contained shall be construed to invalidate or impair the obligation of any treaty heretofore lawfully made and ratified with any such Indian nation or tribe. — Indian Appropriations Act of 1871 The 1871 Act also made it a federal crime to commit murder, manslaughter, rape, assault with intent to kill, arson, burglary, and larceny within any Territory of the United States.[citation needed] Many tribes ignored the relocation orders at first and were forced onto their limited land parcels. Enforcement of the policy required the United States Army to restrict the movements of various tribes. The pursuit of tribes in order to force them back onto reservations led to a number of wars with Native Americans which included some massacres. The most well-known conflict was the Sioux War on the northern Great Plains, between 1876 and 1881, which included the Battle of Little Bighorn. Other famous wars in this regard included the Nez Perce War and the Modoc War, which marked the last conflict officially declared a war. By the late 1870s, the policy established by President Grant was regarded as a failure, primarily because it had resulted in some of the bloodiest wars between Native Americans and the United States. By 1877, President Rutherford B. Hayes began phasing out the policy, and by 1882 all religious organizations had relinquished their authority to the federal Indian agency. The 1871 Act was affirmed in 1886 by the U.S. Supreme Court, in United States v. Kagama, which affirmed that the Congress has plenary power over all Native American tribes within its borders by rationalization that "The power of the general government over these remnants of a race once powerful ... is necessary to their protection as well as to the safety of those among whom they dwell". The Supreme Court affirmed that the U.S. Government "has the right and authority, instead of controlling them by treaties, to govern them by acts of Congress, they being within the geographical limit of the United States. ... The Indians owe no allegiance to a State within which their reservation may be established, and the State gives them no protection." In 1887, Congress undertook a significant change in reservation policy by the passage of the Dawes Act, or General Allotment (Severalty) Act. The act ended the general policy of granting land parcels to tribes as-a-whole by granting small parcels of land to individual tribe members. In some cases, for example, the Umatilla Indian Reservation, after the individual parcels were granted out of reservation land, the reservation area was reduced by giving the "excess land" to white settlers. The individual allotment policy continued until 1934 when it was terminated by the Indian Reorganization Act. Passed by Congress in 1887, the "Dawes Act" was named for Senator Henry L. Dawes of Massachusetts, Chairman of the Senate's Indian Affairs Committee. It came as another crucial step in attacking the tribal aspect of the Indians of the time. In essence, the act broke up the land of most all tribes into modest parcels to be distributed to Indian families, and those remaining were auctioned off to white purchasers. Indians who accepted the farmland and became "civilized" were made American citizens. But the Act itself proved disastrous for Indians, as much tribal land was lost, and cultural traditions destroyed. Whites benefited the most; for example, when the government made 2 million acres (8,100 km2) of Indian lands available in Oklahoma, 50,000 white settlers poured in almost instantly to claim it all (in a period of one day, April 22, 1889). Evolution of relationships: The evolution of the relationship between tribal governments and federal governments has been glued together through partnerships and agreements. Also running into problems of course such as finances which also led to not being able to have a stable social and political structure at the helm of these tribes or states. The Indian Reorganization Act of 1934, also known as the Howard-Wheeler Act, was sometimes called the Indian New Deal and was initiated by John Collier. It laid out new rights for Native Americans, reversed some of the earlier privatization of their common holdings, and encouraged tribal sovereignty and land management by tribes. The act slowed the assignment of tribal lands to individual members and reduced the assignment of "extra" holdings to nonmembers. For the following 20 years, the U.S. government invested in infrastructure, health care, and education on the reservations. Likewise, over two million acres (8,000 km2) of land were returned to various tribes. Within a decade of Collier's retirement the government's position began to swing in the opposite direction. The new Indian Commissioners Myers and Emmons introduced the idea of the "withdrawal program" or "termination", which sought to end the government's responsibility and involvement with Indians and to force their assimilation. The Indians would lose their lands but were to be compensated, although many were not. Even though discontent and social rejection killed the idea before it was fully implemented, five tribes were terminated—the Coushatta, Ute, Paiute, Menominee and Klamath—and 114 groups in California lost their federal recognition as tribes. Many individuals were also relocated to cities, but one-third returned to their tribal reservations in the decades that followed. In 1934, the Indian Reorganization Act, codified as Title 25, Section 476 of the U.S. Code, allowed Indian nations to select from a catalogue of constitutional documents that enumerated powers for tribes and for tribal councils. Though the Act did not specifically recognize the Courts of Indian Offenses, 1934 is widely considered to be the year when tribal authority, rather than United States authority, gave the tribal courts legitimacy. John Collier and Nathan Margold wrote the solicitor's opinion, "Powers of Indian Tribes" which was issued October 25, 1934, and commented on the wording of the Indian Reorganization Act. This opinion stated that sovereign powers inhered in Indian tribes except for where they were restricted by Congress. The opinion stated that "Conquest has brought the Indian tribes under the control of Congress, but except as Congress has expressly restricted or limited the internal powers of sovereignty vested in the Indian tribes such powers are still vested in the respective tribes and may be exercised by their duly constituted organs of government." In 1953, Congress enacted Public Law 280, which gave some states extensive jurisdiction over the criminal and civil controversies involving Indians on Indian lands. Many, especially Indians, continue to believe the law unfair because it imposed a system of laws on the tribal nations without their approval. In 1965, the United States Court of Appeals for the Ninth Circuit concluded that no law had ever extended provisions of the U.S. Constitution, including the right of habeas corpus, to tribal members brought before tribal courts. Still, the court concluded, "it is pure fiction to say that the Indian courts functioning in the Fort Belknap Indian community are not in part, at least, arms of the federal government. Originally they were created by federal executive and imposed upon the Indian community, and to this day the federal government still maintains a partial control over them." In the end however, the Ninth Circuit limited its decision to the particular reservation in question and stated, "it does not follow from our decision that the tribal court must comply with every constitutional restriction that is applicable to federal or state courts." Richard Nixon took office as president in 1969. From 1969 to 1974, the Richard Nixon administration made important changes to United States policy towards Native Americans through legislation and executive action. President Richard Nixon advocated a reversal of the long-standing policy of "termination" that had characterized relations between the U.S. federal government and American Indians in favor of "self-determination." The Alaska Native Claims Settlement Act restructured indigenous governance in Alaska, creating a unique structure of Native Corporations. Some of the most notable instances of American Indian activism occurred under the Nixon Administration, including the Occupation of Alcatraz and the Occupation of Wounded Knee. It was under his administration that Washington state Senator Henry M. Jackson and Senate Subcommittee on Indian Affairs aide Forrest J. Gerard were most active in their reform efforts. The work of Jackson and Gerard mirrored the demands of Indians for "self-determination." Nixon called for an end to termination and provided a direct endorsement of "self-determination." In a 1970 address to Congress, Nixon articulated his vision of self-determination. He explained, "The time has come to break decisively with the past and to create the conditions for a new era in which the Indian future is determined by Indian acts and Indian decisions." Nixon continued, "This policy of forced termination is wrong, in my judgment, for a number of reasons. First, the premises on which it rests are wrong. Termination implies that the federal government has taken on a trusteeship responsibility for Indian communities as an act of generosity toward a disadvantaged people and that it can therefore discontinue this responsibility on a unilateral basis whenever it sees fit." Nixon's overt renunciation of the long-standing termination policy was the first of any President in the post-World War II era. While many modern courts in Indian nations today have established full faith and credit with state courts, the nations still have no direct access to U.S. courts. When an Indian nation files suit against a state in U.S. court, they do so with the approval of the Bureau of Indian Affairs. In the modern legal era, the courts and Congress have, however, further refined the often competing jurisdictions of tribal nations, states and the United States in regard to Indian law. Today the United States recognizes 574 Tribal nations, 229 of which are in Alaska. The National Congress of American Indians explains, "Native peoples and governments have inherent rights and a political relationship with the U.S. government that does not derive from race or ethnicity." In the 1978 case of Oliphant v. Suquamish Indian Tribe, the Supreme Court, in a 6–2 opinion authored by Justice William Rehnquist, concluded that tribal courts do not have jurisdiction over non-Indians (the Chief Justice of the Supreme Court at that time, Warren Burger, and Justice Thurgood Marshall filed a dissenting opinion). But the case left unanswered some questions, including whether tribal courts could use criminal contempt powers against non-Indians to maintain decorum in the courtroom, or whether tribal courts could subpoena non-Indians. A 1981 case, Montana v. United States, clarified that tribal nations possess inherent power over their internal affairs, and civil authority over non-members on fee-simple lands within its reservation when their "conduct threatens or has some direct effect on the political integrity, the economic security, or the health or welfare of the tribe." Other cases of those years precluded states from interfering with tribal nations' sovereignty. Tribal sovereignty is dependent on, and subordinate to, only the federal government, not states, under Washington v. Confederated Tribes of Colville Indian Reservation (1980). Tribes are sovereign over tribal members and tribal land, under United States v. Mazurie (1975). In Duro v. Reina, 495 U.S. 676 (1990), the Supreme Court held that a tribal court does not have criminal jurisdiction over a non-member Indian, but that tribes "also possess their traditional and undisputed power to exclude persons who they deem to be undesirable from tribal lands. ... Tribal law enforcement authorities have the power if necessary, to eject them. Where jurisdiction to try and punish an offender rests outside the tribe, tribal officers may exercise their power to detain and transport him to the proper authorities." In response to this decision, Congress passed the 'Duro Fix', which recognizes the power of tribes to exercise criminal jurisdiction within their reservations over all Indians, including non-members. The Duro Fix was upheld by the Supreme Court in United States v. Lara, 541 U.S. 193 (2004). Federal acknowledgment Following the decisions made by the Indian Claims Commission in the 1950s, the BIA in 1978 published final rules with procedures that groups had to meet to secure federal tribal acknowledgment. There are seven criteria. Four have proven troublesome for most groups to prove: long-standing historical community, outside identification as Indians, political authority, and descent from a historical tribe. Tribes seeking recognition must submit detailed petitions to the BIA's Office of Federal Acknowledgment. To be formally recognized as an Indian tribe, the US Congress can legislate recognition or a tribe can meet the seven criteria outlined by the Office of Federal Acknowledgment. These seven criteria are summarized as: The federal acknowledgment process can take years, even decades; delays of 12 to 14 years have occurred. The Shinnecock Indian Nation formally petitioned for recognition in 1978 and was recognized 32 years later in 2010. At a Senate Committee on Indian Affairs hearing, witnesses testified that the process was "broken, long, expensive, burdensome, intrusive, unfair, arbitrary and capricious, less than transparent, unpredictable, and subject to undue political influence and manipulation." The number of tribes increased to 567 in May 2016 with the inclusion of the Pamunkey tribe in Virginia who received their federal recognition in July 2015. The number of tribes increased to 573 with the addition of six tribes in Virginia under the Thomasina E. Jordan Indian Tribes of Virginia Federal Recognition Act of 2017, signed in January 2018 after the annual list had been published. In July 2018 the United States' Federal Register issued an official list of 573 tribes that are Indian Entities Recognized and Eligible To Receive Services From the United States Bureau of Indian Affairs. The Little Shell Tribe of Chippewa Indians of Montana became the 574th tribe to gain federal recognition on December 20, 2019. The website USA.gov, the federal government's official web portal, also maintains an updated list of tribal governments. Ancillary information present in former versions of this list but no longer contained in the current listing has been included here in italic print. Notes References Further reading See also External links |
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[SOURCE: https://en.wikipedia.org/wiki/Paleontologist] | [TOKENS: 13588] |
Contents Paleontology Paleontology or palaeontology is the scientific study of the life of the past, mainly but not exclusively through the study of fossils. Paleontologists use fossils as a means to classify organisms, measure geologic time, and assess the interactions between prehistoric organisms and their natural environment. While paleontological observations are known from at least the 6th century BC, the foundation of paleontology as a science dates back to the work of Georges Cuvier in 1796. Cuvier demonstrated evidence for the concept of extinction and how the life of the past was not necessarily the same as that of the present. The field developed rapidly over the course of the following decades, and the French word paléontologie was introduced for the study in 1822, which was derived from the Ancient Greek word for 'ancient' and words describing relatedness and a field of study. Further advances in the field accompanied the work of Charles Darwin who popularized the concept of evolution. Together, evolution and extinction can be understood as complementary processes that shaped the history of life. Paleontology overlaps the most with the fields of geology and biology. It draws on technology and analysis of a wide range of sciences to apply them to the study of life and environments of the past, particularly for the subdisciplines of paleobiology and paleoecology that are analogous to biology and ecology. Paleontology also contributes to other sciences, being utilized for biostratigraphy to reconstruct the geologic time scale of Earth, or in studies on extinction to establish both external and internal factors that can lead to the disappearance of a species. Much of the history of life is now better understood because of advances in paleontology and the increase in interdisciplinary studies. Several improvements in understanding have occurred from the introduction of theoretical analysis to paleontology in the 1950s and 1960s which led to the rise of more focused fields of paleontology that assess the changing geography and climate of Earth, the phylogenetic relationships between different species, and the analysis of how fossilization occurs and what biases can impact the quality of the fossil record. Paleontology is also one of the most high profile of the sciences, comparable to astrophysics and global health in the amount of attention in mass media. Public attention to paleontology can be traced back to the mythologies of indigenous peoples of many continents and the interpretation of discovered fossils as the bones of dragons or giants. Prehistoric life is used as the inspiration for toys, television and film, computer games, and tourism, with the budgets for these public projects often exceeding the funding within the field of paleontology itself. This has led to exploitation and imperialism of fossils collected for institutions in Europe and North America, and also appeals to the public for sponsorships to the benefit of some areas of paleontology at the detriment of others. Concept Paleontology (also spelled palaeontology) is the study of life of the past, characterized but not defined by the study and interpretation of fossils. It overlaps with the fields of geology and biology especially, but also with ecology, chemistry, physics and mathematics. Paleontology consists of both conceptual theorizing and focused scientific study. Traditionally, the sub-field of invertebrate paleontology has been closely tied to the study of geology, biostratigraphy, and historical geology, which have both commercial and academic drivers, whereas vertebrate paleontology has been more closely tied to biology with limited commercial applications. Both areas of study have broadened over time as a result of developing technology, but the "classical" requirements of fieldwork, laboratory preparation, and study of comparative anatomy remain core components of most sub-fields of paleontology. Paleontological study provides a direct source of information on the anatomy, physiology, ecology, and chronology of life on Earth, and the fossil record can be used to test hypotheses relevant to a range of scientific disciplines including other earth sciences and life sciences. The word paleontology or palaeontology is a compound word formed from the roots "paleo-", "onto-" and "-logy", equivalent to the French word paléontologie or the German word Paläontologie. The spelling paleontology is primarily used in North America, while the spelling palaeontology is preferred in the United Kingdom and was historic spelled as palæontology. Multiple different pronunciations can be found, including /ˌpeɪliɒnˈtɒlədʒi/ (pay-lee-uhn-TOL-uh-jee), /ˌpæliənˈtɒlədʒi/ (pal-ee-uhn-TOL-uh-jee), and /ˌpeɪliənˈtɑːlədʒi/ (pay-lee-uhn-TAH-luh-jee). The root word "paleo-" is from the classical Latin or scientific Latin palaeo- and its predecessor Ancient Greek παλαιο- meaning "ancient" or "old", the root noun "onto-" is from the Ancient Greek ὀντ- meaning a sense of relatedness, and the root word "-logy" is from the French ‑logie which derives from the classical Latin ‑logia and the Ancient Greek ‑λογία and in context means a field of study. Foundation Paleontology includes the study of extinct animals and plants, including both direct observations about their remains and inferences about their behavior and how they interacted with their environment. From the recognition that fossils represented the remains of extinct organisms, paleontology became the zoology, botany, and biology of extinct organisms and therefore an important source for comparative anatomy. It was not always understood that paleontology is an evolutionary science, but over time, instances of evolution were recognized in the fossil record, and the two concepts have been closely linked ever since. The long span of geological time preserved in the fossil record allows very slow evolutionary changes to be observed, and the discovery of extinct organisms has allowed scientists to fill in gaps in the tree of life that cannot be understood through the study of extant organisms. The incorporation of a wider range of life sciences has allowed sub-disciplines like paleobiology and others to emerge. Prior to the 19th century, the word "fossil" was used as a descriptive noun to characterize anything that had been dug out of the ground, including bones, stones, and gems. Early descriptions of what we now understand to be fossils described their appearances alongside and in the context of other minerals, crystals, and rocks. These early publications varied in contents of "fossils" across a wide spectrum of inorganic to organic appearances, including true fossils of differing preservation qualities, inorganic concretions, and structures with a resemblance to organisms. Over time the criteria for separating organic fossils from potentially organic or clearly inorganic materials brought about a change in the etymology of the word "fossil" itself, so accounts before the 19th century may not reflect the same use of the word fossil as modern paleontology. Both inorganic and organic fossils were illustrated in numerous books on the topic throughout the 16th century, with some attributing them to the work of God and other suggesting applications in construction or medicine. Fossils were not believed to have been organic, but instead to have exhibited the same kind of "growth" as crystals. Support for a possibly organic nature of fossils began in the 17th century, though it remained contentious as different quarries or strata yielded different fossils, which the scientists of the time did not have the context to explain. The fact that most fossils came from organisms that had never been observed alive anywhere in the world seemed to imply that these organisms were extinct, which was contrary to the belief of a perfect divine creation. Another compounding factor was that fossils of apparently marine animals were found in parts of the world that were well above sea-level. Some suggested that these fossils had accumulated in horizontal layers under the sea and that subsequent tectonic activity had displaced them from their original positions. As these observations were made over time, it was eventually understood that fossils could be used to make inferences about the history of life from their presence or absence in particular areas over time. The fossil record is the main tool used by scientists to study the history of life and assess the diversification of life over time. Very little is known about the origins of life and the oldest life forms, and this is likely a result of the poor quality of fossil preservation in older rocks. Older rocks preserve less information on average than those deposited closer to the present, and this effect is compounded across the billions of years that life is believed to have existed. Most fossils are made up of the hard parts of an organism that have been recrystallized by minerals, preserving bone, wood, or shells in a material than can be harder or denser than in life. While the hard parts are the most likely to fossilize, soft tissues can also leave impressions on sediment before they fully decompose, allowing non-mineralized parts of an organisms anatomy to be preserved. Even more rarely, a complete organism can be encased in sediment before decomposition, preserving it completely. While most fossils are body fossils (made of the actual body parts of a dead organism), some fossils can also consist of traces of the behaviour or life of organisms. This can include preserved burrows, footprints or coprolites, which are grouped together and called trace fossils. However, only a small minority of all dead organisms will ever become fossils. Some things can destroy organisms before or even after fossilization, including scavengers, decomposers, or natural disasters, and fossils can even be destroyed after they are formed by taphonomic processes. Even if a fossil survives burial, it can still be destroyed by weathering if it is exposed and not collected. The habitat of an organism can also impact its chances of fossilization. Seafloors are more likely to fossilize than land, and rivers or lakes are more likely to fossilize than mountains or deserts. Fossilized teeth are very common, but are not always collected when they are found, and more complete fossils may be more likely to be collected, but they are generally rarer in absolute terms. Even after collection, fossils may not be studied for a long time. They may remain in museum storage in crates, be on display, or be otherwise unaccessible to scientists. The earliest discussions in the field of geology centered around the possible origins of geological features and what implications these had on Christianity. The concept of a history of Earth had existed for a long time, and those who studies rocks of fossils had come to the idea of changes over time. However, in the beginning of the field of geology in the early 19th century, the most common explanation for causes of geological change were that they were the result of sedimentation during the Biblical Flood, rather than slow processes drawn out over millions of years. French naturalist Georges Cuvier and his contemporaries believed that the Earth was not recently created (as in Young Earth Creationism), nor had it been around forever. They instead believed that there was a vast "prehuman" or antediluvian history. Cuvier was not the first to believe in a lengthy but finite age of the Earth, but he was the first to combine this idea with his study of fossils to suggest prehistoric events could be understood through the study of geology and the fossil record. Studies on rocks and their stratigraphy continued, including the development of geological maps highlighting the relative ages of regional geologic formations, and it was still believed that the Biblical Flood was a primary explanation for the formation of these features. English geologist Charles Lyell was among the first to propose that a great flood had not occurred, and this was supported by the existence of overlapping terrestrial and marine sediment layers. He observed that the twisting, uplifting and carving of geological features supported the idea that the crust was moving continuously, and the sea level was also adjusting over time. This interpretation was not only supported by the differing levels of marine strata, but also by the shared commonality of fossils he found within them, even across large distances and at different levels above the sea. Combining these facts with his own previous work led Lyell to suggest some core principles of the history of the Earth. He suggested that here were progressive trends in the history of life, that geological history was continuously changing with periods of calm and chaos, and that the causes of these geological events were as much around in present day as in the deep past. Following the ongoing study of geology, geologic formations, and the establishment of geochronology, the geologic time scale was created to separate and categorize the vast history of Earth into a scale of named geochronologic units, defined and standardized by the International Commission on Stratigraphy. The age and duration of different units has changed over time following further restudy including absolute and relative dating of different sediments, with the current standard recognizing four eons, ten eras, 22 periods, 37 epochs and 96 ages. Present day is recognized as the Meghalayan age, of the Holocene epoch, of the Quaternary period, of the Cenozoic era, of the Phanerozoic eon. These geological time units are correlated globally through combinations of assigned times, index fossils, paleomagnetism, and other methods, with the correlation of taxa with time being termed biochronology. Through biochronology, paleontological events such as the evolution, extinction, or speciation of a taxon can be established at a point in time, and features such as mass extinctions can be identified. Fossils have been documented from at least as far back as Ancient Greece. However, the belief of philosophers including Plato and Aristotle was that anything that existed had existed forever and would exist forever, or was along a continuum of perfection without any gaps. As a result of this fundamental belief, evidence of extinction was ignored or explained away by naturalists for most of recorded history. It was not until the work of Cuvier with the publication of his Recherches sur les ossemens fossiles (or Investigations on fossil bones), that extinction was understood and considered the principal basis for paleontology as a science. By the early-mid 19th century, it was no longer controversial that fossil animals existed in a sequential order and as a result that fauna and flora were changing over time. Cuvier himself denied that there was any direct continuity from any of these fossils to organisms alive in the present day, and thus that all were extinct. However, he also did not believe the idea that any presently extant organisms had been alive in the past. Instead he believed that over time great "revolutions" occurred in which all living organisms went extinct, and new ones arose, which was consistent with belief in the Biblical Flood. It was not until English naturalist Charles Darwin suggested that extinction and evolution both occurred together, that a full explanation could be given for changes of life over time. The fossil record showed that there was not a predetermined length of time for which a particular organism (or group of organisms) existed, and it also gave evidence for periods where a large percentage of organisms went extinct at once, which could be the result of mass extinction events. Extinction can be seen as the final step of evolutionary change for any species. While modern biologists assess rates of extinction can be through the presence or absence of species in nature, paleontologists are limited in their understanding of this by the inherent rarity of fossils and the incompleteness of the fossil record. These difficulties make it more challenging to infer what extinction rates were in the past, and can make it difficult to differentiate between a true extinction and a "pseudoextinction", where one species evolves directly into another. Extinction of a species can occur from a variety of causes, and the intensity of extinction rates vary significantly over time. At least five mass extinction events are recognized to have occurred during the history of Earth, and it is also possible that the Earth is currently undergoing a sixth extinction as a result of human activity. However, mass extinction events only account for a small percentage of total species extinctions. Most extinctions occur as a result of other causes at differing times throughout Earth's history, which is sometimes called the background extinction rate. For most organisms in the fossil record, it is impossible to determine the cause of extinction in particular or even general cases. For most of human history, philosophers, theologians, and other intellectuals believed that the world was perfectly ordered by divine forces and could not have come about from natural processes. There are exceptions such as the Greek philosopher Empedocles who thought that fossils may have come from organic life that had undergone change, but this was the exception. Most religious doctrines, including Christianity and Judaism, taught that the world was created by God as it currently exists, so life could not have progressed and the natural world was instead the product of intelligent design. The evolutionary significance of the fossil record was not initially recognized because individual fossils only show snapshots of evolutionary history. However, recognition of the ability for traits to be passed to later generations was used by French naturalist Jean-Baptiste Lamarck in the 19th century to argue for evolution. Early proponents of evolution initially believed that God had set the world in motion but let it progress naturally, while critics such as Cuvier thought that intermediate forms required would have been unable to survive and so rejected the possibility of evolution outright. Influenced by the writings of Lyell, Charles Darwin studied similarities in organisms during his time aboard the HMS Beagle which would eventually became the book On the Origin of Species. In it, Darwin proposed the concept of natural selection which would become fundamental to the later theory of evolution. Darwin also suggested that gaps in the fossil record were the result of incomplete fossilization and that transitional fossils would eventually be found that would corroborate the theory of evolution. Paleontologists cannot use the species concepts of modern biology due to limitations of working on fossils rather than living organisms. However, differences in the morphology of organisms based on their fossil remains can be used to separate phenotypes. Once phenotypic differences in a population of organisms accumulate, they should become genetically isolated and thus separate species. Therefore, the phenotypes observed in fossils can be used as a proxy to infer differences between species throughout deep time. It is possible that these evolutionary and morphological changes occurred slowly and gradually as is hypothesized by phyletic gradualism, or that short bursts of rapid evolution occurred in punctuated equilibrium. Evidence for both methods of macroevolution are present in the fossil record, and the discovery of new fossils continuously helps to fill gaps in our understanding of the evolutionary history of life. History Cuvier is generally regarded as the first paleontologist, and the origins of paleontology as a science trace their origins directly to his demonstrations that fossils in stone were traces of organisms that were once alive but had gone extinct. Despite this, he was far from the first to write about fossils or make observations about things found in rock. Isolated comments from writers about fossils can be found going back to classical antiquity. The philosopher Xenophanes (6th century BCE) believed fossil shells represented life from the past, whereas Aristotle instead explained fossils as "vaporous exhalations". Aristotle's belief was later refined into the theory of a petrifying liquid by Arabic philosopher Avicenna and German philosopher Albert of Saxony in the middle ages. Chinese naturalist Shen Kuo also proposed a theory of climate change around this time based on the presence of petrified bamboo in regions that in his time were too dry for bamboo. In unpublished notebooks, the Italian polymath Leonardo da Vinci justified an organic origin for the fossil shells available to him. His notes show observations of living mollusks and their ecology, the processes of sedimentation, and the recognition that the fossil shells had similar features, showed similar growth stages, and had similar pathologies to living mollusks. Da Vinci's study of sedimentation meant he understood why fossils were usually embedded in rocks, and his notes demonstrate a very modern interpretation of the origin of fossils. He rejected the Aristotelian theory of vapors and also did not believe that the Biblical Flood was the primary cause of fossil formation. Da Vinci's notebooks may have inspired others of the time to accept a biologic origin of fossils, but this belief was not accepted by everyone. In addition to his study of body fossils, da Vinci is also credited as the founder of the field of ichnology, which is primarily concerned with trace fossils and how they can provide insights into the behavior of extinct organisms. In the 17th century, naturalists like the Danish scientist Nicolas Steno and the English polymath Robert Hooke provided further discussions on the origins of fossils. The general belief was that fossils were of organic origin, but that they had been fossilized by petrifying liquids and moved into elevation by the Biblical Flood or some other means. Conversely, the English physician Martin Lister completely rejected the possibility of organic fossil origins. The fossils available to Steno, da Vinci, and others mentioned above were primarily the easily-identifiable shells of marine animals, and their organic origin was a relatively straightforward inference. The fossils in England were from rocks dating to the Jurassic or Carboniferous and came from a variety of different organisms that bore no clear resemblance to modern organisms. Many explanations were suggested for the posible inorganic or organic origins of fossils, how they came to be lithified, and how they ended up far above the sea, but the ideas of extinction and deep time had not yet been developed, so an explanation eluded naturalists of the time. A significant moment in the history of paleontology was the publication of the 1796 paper On the species of living and fossil elephants by Georges Cuvier, which contained detailed evidence for extinction. Cuvier named the fossil taxon Megatherium, based on bones found in Paraguay. The large size of these bones made it unlikely that they were from an extant, but undiscovered, animal. Cuvier reached a similar conclusion regarding the fossils named the mastodon, with the uniqueness of these animals demonstrating that they belonged to species that were no longer alive and thus extinct. To further justify this conclusion, Cuvier extensively studied the fossils of elephants and proved the distinction of mammoths from Siberia and Europe from their living relatives. Presenting this work on the extinction of the megafauna, Cuvier termed the events that led to their disappearance "revolutions", contrasting with the idea of gradual change in the environment and the fauna within it. Of the three possibilities leading to the disappearance, Cuvier supported extinction over migration as well as over evolution as suggested by Lamarck, with his view that extinction and evolution were conflicting explanations. Cuvier also studied the comparative anatomy of both living and fossil organisms and developed a way to assess their morphological characters, which opened the door for developing an understanding of the animals of the past. Developments in the fields of stratigraphy and paleontology following the work of Cuvier became widespread throughout Europe, and the classification of extinct organisms into different groups that included their living relatives also proliferated. While most of Cuvier's early studies had been on mammals, there were some fossils with no close living analogues such as the bird-like fossil reptile he called the Ptero-dactyle or the fish-like marine reptiles that were eventually named ichthyosaurs. It was in 1822 that Henri Marie Ducrotay de Blainville, a former student of Cuvier, introduced the name paléontologie for the study of these ancient beings. He had earlier introduced the names paléozoologie and paléosomiologie for the studies of fossil animals and fossils in general, respectively, but the latter did not see widespread use and paleontology was the name generally adopted for the field by naturalists of the time. Some of the most significant discoveries of this early time in paleontology were made by Mary Anning and her family, who uncovered skeletons from a variety of marine reptiles and other animals in the Lyme Regis region including Ichthyosaurus and Plesiosaurus. These animals were geologically older than the mammals of Cuvier's earlier work, and this relative age became the study of stratigraphy which enabled scientists to date and order animals relative to one another in geologic time. The works of Cuvier and Lamarck on extinction and the history of life, and the works of Lyell and English geologist Adam Sedgwick on geology, were all synthesized by Charles Darwin in his seminal works on the theory of evolution. He suggested that the history of life was full of gradual changes, with the constant presence of extinction acting as the driver evolution through natural selection. This was validated by multiple discoveries soon after Darwin began publishing. The discovery of the theropods Compsognathus and Archaeopteryx demonstrated evidence for the progressive evolution of birds from other reptiles, which shifted paleontological study in the direction of studying the evolution of life. For a time paleontology was considered a sub-discipline of geology with relatively little study given to the biological aspects of the field, and paleontology was generally not treated as an important field of study of either science. Over the subsequent decades, geology and biology advanced to theory-based analysis while paleontology lagged behind as a field focused primarily on stratigraphy. This changed with the development of paleobiology in the second half of the 20th century. This shift was driven by conceptual changes in the study of evolution and phylogenetics and the emergence of new ways to study geology through biostratigraphy, paleobiogeography, taphonomy and paleoclimatology. Phylogenetics were developed as a way to quantitatively analyze and interpret the evolution and relationships of organisms, providing context and predictability for evolutionary processes and the impacts of mass extinctions and their recoveries. Paleoecology itself has seen the emergence of subdisciplines including the field of taphonomy to study the nature of the fossil record. Emphasis was also given to the analysis of diversity and the distribution of taxa, the study of trace fossils, the understanding of paleoenvironments, and conservation paleobiology. Advancements in technology and the analytical tools of other sciences have also been integrated into paleontology including geochemical analysis, molecular biology, and other computer-aided visualization or analysis techniques. The heyday of paleontology was arguably in the Victorian era, with little substantial change since beyond the notable discoveries of new taxa. These on their own have done little to change our overall understanding of the history of life. However, the history of life is not just the story of evolutionary changes, and paleontology has increasingly broadened to include a wider variety of scientific questions. The sizes of the largest dinosaurs, pterosaurs, or arthropods pose interesting questions to study in the fields of biomechanics, ontogeny, and physiology. Diversification and mass extinction can be predicted and better understood from the studies of phylogenetics, and as technologies and precision improve, the depth to which we understand life of the past will increase. Applications Paleontology both draws from and contributes to the fields of geology and biology, despite historically being dismissed as an undemanding science. Analysis and description of fossils allows the researchers to illustrate biological, geological, ecological and tectonic changes and phenomena which have implications for our understanding of science in the present. Many disciplines and areas of study interact with paleontology and overlap in some areas with the field. Through this overlap, paleontology has the ability to better our understanding of the origin, diversity and evolution of life, and can be used by other fields to investigate patterns in the fossil record. In the modern day, paleontology is viewed as important by researchers. Its study enables scientists to understand the history of life. It can explain different worlds of the past and the impact of a changing climate and biodiversity, and paleontology helps expand our understanding of both evolution and extinction. Subfields of paleontology also enable geologists to robustly establish the ages of various rock formations. Paleontological discoveries have discussed the origins and history of life for centuries, with very little knowledge of life before the Cambrian for a significant amount of time. Fossils from prior to the Cambrian were limited to 2.1 billion year old fossilized algae and possibly "plants" until the discoveries of fauna in the Bitter Springs Group and Apex chert of Australia, the Mistaken Point Formation of Canada, and the Doushantuo Formation of China, all of which have significantly expanded knowledge of the Ediacaran biota that includes a range of life from microscopic single-celled organisms to macroscopic multicellular life. Fossil discoveries have also improved knowledge about the Cambrian explosion with the discoveries of multiple new lagerstätte deposits. The Burgess Shale was one of the first such deposits and has been further explored, and around 40 other Burgess-type localities are now known globally. These localities are filled with soft-bodied taxa that show the decline of the Ediacaran biota and the emergence of other kinds of metazoan life. The refinement of Cambrian stratigraphy will also improve the understanding of these early faunas and how they changed over time. Through advances in paleontology many other evolutionary paths have become better understood even in more recent life. The evolution of birds is now understood to have occurred from gradual evolutionary changes in saurischian dinosaurs up to the point where it is difficult to draw a line between what dinosaurs are or are not birds. The origins of dinosaurs themselves are better understood from the discoveries of multiple near-dinosaur taxa. Discoveries within the Eocene of fossil mammals have allowed for the evolution of whales to be nearly completely understood, with the fully terrestrial mesonychids becoming gradually amphibious before becoming aquatic swimmers. Relatives of modern whales such as Basilosaurus were obligate swimmers, but even then had not developed the bauplan of modern cetaceans that occurred over further gradual evolution. The evolution of reptile groups such as ichthyosaurs and turtles, while still controversial, is much better understood with finds such as the early incompletely-shelled turtle Proganochelys. Human evolution is also much better understood from progress in paleontology, including both the evolution of hominids from basal primates as well as the speciation and origins of humans within the hominids. Fossils of Australopithecus and Ardipithecus show that humans never transitioned through an ape-like stage, instead being bipedal with adaptations for arboreal locomotion. Adripithecus is known from lowland forest environments, and not grasslands, suggesting the origins of humanity within a variable and unpredictable habitat. The evolution of humans within the genus Homo is similarly complex and does not follow a clean linear path as sometimes described. Some species of Homo may have overlapped in time and place with others, but all show that then evolution of the genus was likely in Africa. Advancements and new discoveries have also shown that the neanderthals were a complex society with the use of tools, clothes, and having their own mythology. DNA from neanderthals and humans show substantial differences, but also that there was interbreeding between populations. The idea of a mass extinction has been around since the beginning of paleontology and is generally accepted as true events that drive the evolution of life. However, the question of what makes an extinction event a "mass extinction" is still uncertain. On the scale of geologic time, mass extinction events happen rapidly, and such rapid events can be caused by both gradual environmental processes and large-scale catastrophes. A notable exception to this rule is the Cretaceous-Paleogene extinction event, which is believed to have been caused by an asteroid impact which caused global wildfires and a disruption of the nutrient cycle in the ocean. If this is the case, it would be an unprecedentedly rapid extinction event, occurring over the course of one or a few years. However, even this extinction's cause is debated. Some have suggested that it was caused by marine regression or volcanism that occurred near or at the same time as an impact. No other extinction events can be linked clearly with an extra-terrestrial cause. Glaciation and subsequent global warming has been suggested as a cause for the Late Ordovician mass extinction, and the volcanic activity of the Siberian Traps large igneous province has been suggested as the primary cause for the Permian-Triassic mass extinction. The causes of the Late Devonian mass extinction and the Triassic-Jurassic mass extinction remain mostly uncertain to this day. The period of ecological recovery following a mass extinction is also a significant time for biodiversity and adaptive radiation. The term "disaster species" has been applied to the organisms that follow an ecological disruption, and there are many known from the fossil record. Following the Cretaceous-Paleogene extinction, there is a large spike in the abundance of fossil ferns that is interpreted as an early post-extinction flora that would later be overtaken by different floral communities. There is a similarly rapid diversification of small, generalist mammals for the first 3 million years before more diverse faunal communities evolved. However, not all mass extinctions have similarly rapid diversification events. The recovery period following the Permian-Triassic extinction took up to 10 million years. The recovery of ecosystems from mass extinctions involves the evolution of novel ecological relationships between groups of animals that would not have been possible in the pre-extinction ecosystem. Fossils have been used for stratigraphic correlation since at least the 18th century. Observed changes in the fossils found through geologic time led to the principle of ecological succession, however this study was not elaborated on until the 1960s. The first and last appearance of a taxon in the fossil record can be used to compare the relative ages of different lithographic sections of sediment. This principle allows for relative ages of different sediments to be determined more precisely. These "index fossils" are combined with measurements of volcanic ash, paleomagnetic reversals, or pre-dated sediments to make precise measurements of geologic time. For example, the Jurassic Period was named and defined based on ten main subdivisions identified through the English and French assemblages of ammonites, some of which are still in use today. Biostratigraphy is also applied to the analysis of stratotype sections and boundaries of geologic time units. It can also use the first or last appearance date of a taxon to establish time periods that are independent of their constituent strata. The geologic time scale is based primarily on the biostratigraphy (correlating strata) and equivalent biochronology (correlating times) of the appearance and disappearance of various fossil taxa. Some factors can introduce uncertainty into this process including the quality or quantity of sampled fossils. Different graphical and numerical methods are used in the construction of the geologic time scale. Even the Ediacaran, which is poorly represented through fossils, can be assessed using biostratigraphy in combination with chemostratigraphy and absolute dating. The biostratigraphy of the Ordovician and Silurian is based primarily on fossils of graptolites and conodonts. Other common groups used in zonation include ammonites, foraminifera, and plant pollen, where it is preserved. The foundation of modern taxonomy is the scheme of hierarchy adopted by Carl Linnaeus where taxa were grouped in taxonomic categories. While Linnaean hierarchy was not the first system, it formed the basis for subsequent systems, with seven principle categories arising to classify life: Kingdom, Phylum, Class, Order, Family, Genus, and Species (Division instead of Phylum for botany). Intermediate categories were also developed, though they were not considered mandatory to specify. Following On the Origin of Species in 1859, the concept of taxonomic hierarchy shifted to describe common descent through evolution rather than similarity, rendering some previously-accepted groups non-monophyletic as they excluded descendants. The continued trend of emphasizing evolutionary descent has led to a reduced significance of Linnaean taxonomy because of these inconsistencies. An important development classification in modern paleontology was the adoption of phylogenetic systematics as a tool to study the evolutionary tree of life. The use of phylogenetics allows scientists to quantitatively describe the relatedness of organisms through reconstructions of evolutionary trees. Phylogenetic analysis was first applied to the fields of entomology and ichthyology, after extensive debates within those fields before being adopted by evolutionary biologists more broadly. By using systematics, scientists can test and retest hypotheses about evolutionary relationships, and the results are typically displayed as a cladogram. The widespread use of systematics coincided with the advent of molecular biology, which has allowed scientists to use genetic data in addition to morphological data to study evolutionary relationships. Classification systems in general have also shifted in favor of phylogenetics. The Linnean classification scheme with its well-defined taxonomic ranks has gradually fallen out of use, because it does not generally perform well as a reflection of true evolutionary relationships. Further applications of classification to paleontology include more focused issues such as delineating the distinction between microevolution and macroevolution. Microevolutionary paleontology is the study of how evolutionary pressure impacts the ability of single individuals to survive over others, while macroevolutionary paleontology focuses on the ability of whole species to survive over others. Some scientists have suggested that microevolution and macroevolution are separate processes, with morphological changes originating from speciation rather than gradual anagenesis of a population. Others have argued that both individuals and populations are affected by natural selection. Subdisciplines Paleontology overlaps and integrates with many other disciplines of science into fields that focus on more specific topics. The overlap of paleontology with biology, paleobiology, includes studies on macroevolution, extinction, speciation, diversification, morphology, biogeography, phylogeny, paleoecology, molecular paleontology, taphonomy, and evolutionary developmental biology. Many subdisciplines of paleontology are focused on specific groups of organisms: invertebrate paleontology is the study of fossil invertebrates; vertebrate paleontology is the study of fossil vertebrates; paleoalgology is the study of fossil algae; paleobotany is the study of fossil plants; paleoentomology is the study of fossil insects; paleoherpetology is the study of fossil reptiles and amphibians; paleoichthyology is the study of fossil fish; paleomalacology is the study of fossil mollusks; paleomammalogy is the study of fossil mammals; paleomycology is the study of fossil fungi; paleomyrmecology is the study of fossil ants; paleornithology is the study of fossil birds; paleoprimatology is the study of fossil primates; and paleozoology is the study of fossil animals. Paleontology in general also overlaps with studies on growth, paleoanthropology, many fields that focus on the Earths climatic and geographic past, histology, ichnology, pathology and forensics, and taphonomy, forming the subdisciplines described below. Paleoanthropology is a field of study that focuses on the evolutions of humans. The field can trace its origins to the works of German naturalist Johann Blumenbach in the late 18th century and then the discovery of a neanderthal in the mid 19th century though it only took its modern form as the study of human evolution following World War II with the acceptance of evolutionary biology. Paleoanthropology utilizes information on humans drawn from both fossils and archaeology to interpret the rise and spread of humans. Beliefs were that only a single species of hominid was present at any one time, forming a natural progression to modern humans, considering the diverse groups of species proposed as synonyms. Discoveries showed that this belief was not correct, with human evolution displaying a complex and uncertain arrangement of individuals, populations, and species with the advent of phylogenetic analyses. Ardipithecus is one of the oldest known of the human branch of hominids, having lived 4.4 million years ago and only found in 1994. Species of the genus Australopithecus from across Africa have been named since the 1970s are slightly younger, but already show the bipedal stance of modern humans. From Australopithecus likely evolved both Homo and the more robust hominid Paranthropus, which is unlike modern humans in build but lived alongside early humans for some time. It is known that early humans were capable of making and using tools from the discoveries of fossils of Homo habilis in places where stone tools had previously been found. The earliest known stone tools are from around 3.3 million years ago, and while they are often associated with Homo it is also possible that the coexisting species Australopithecus garhi was a toolmaker. There is reluctance to believe that a australopith was capable of making and using tools, but the origins of Homo are unclear and there is little that can be used to distinguish tool-making from non-tool-making hominids when fossils and tools are not found together. The first humans to show a more slender modern bauplan are those of Homo ergaster, which is sometimes considered part of African Homo erectus, from around 1.6 million years ago. Once the modern body form evolved, humans spread far beyond Africa, spreading across Eurasia from which evolved Homo heidelbergensis and Homo neanderthalensis. Though the diversity of neanderthals is uncertain, sites have been found that show they had a burial culture and a rich technological record. The similarities between Homo sapiens and these older or coexisting species makes it difficult to determine what made modern humans unique. Paleobiogeography is a very similar field to biogeography but focuses instead on fossils rather than modern organisms. Both fields work to explain the differences in flora and fauna between different locations, rather than the expectation that regions of similar climate and habitat would house the same organisms. Biogeography relies on exploration, both as an exploratory tool to understand the world, but also the physical act of travelling to different places to observe differences. Paleobiogeography is named with the prefix "paleo" to differentiate in its use of the fossil record to study biogeography, which means that paleobiogeography suffers from the same issues as other paleontological fields regarding the limitations of the fossil record. It was established as a geoscience from the recognition and acceptance of the theory of continental drift that was hinted at by the discoveries of similar fossils on now-distance continents during the 19th century. Paleobiogeography involves studying the history of life, but is relevant for the study of evolutionary, geological, and ecological changes as external factors such as biogeography are one of the two drivers of evolution. Ecological processes can be studied that cause speciation or regulate diversity, and these differences across location can be tied to geological processes like plate tectonics and climate change. Modern biogeography has the advantage of being able to study molecular markers and more thoroughly study small spatial and temporal regions creating a better picture of a specific environment. Paleobiogeography on the other hand is capable of studying very long timescales, able to track history beyond just the modern era. Flora and fauna may be affected by small-scale cycles as well as broader effects that cannot be seen on a limited timescale, so paleobiogeography can provide a more complete picture of patterns and processes. Through the fossil record, paleobiogeography can monitor the evolution and coevolution of life on Earth, associating patterns with geological events and over long timescales, working with the field of biogeography to understand biogeographical processes. Paleobiology is the study of the biology of extinct organisms. As a topic it has been around since the beginning of paleontology itself, as fossils are the remains of extinct organisms, but the areas of research covered by paleobiology have changed to capture much more theoretical thinking, studying the biological aspects of paleontology rather than geological topics like stratigraphy. This means there is a particular focus on evolution, adaptation, ecology, function, and behavior in paleobiology, especially of invertebrates which are far more common in the fossil record. Darwin's work on evolution was largely paleobiological in nature, drawing from paleontology, geology and biology, but also pushed paleontology into the background as the incompleteness of the fossil record became a hindrance to advancements in evolution. The first use of "paleobiology" as a word came in 1893, but it was the work of Othenio Abel in the 1910s that established "päleobiologie" as the study of biologically informed paleontology. Franz Nopcsa is also understood to have been a pioneer of paleobiology, and one of the first paleontologists to use histology and the interpret the paleophysiology of extinct animals. Biological questions did not change the field of paleontology greatly until the general transformation of the field in the 1950s and 1960s with new approaches to the fossil record and a differing view on the place of paleontology as a discipline. Paleontology was no longer seen as a subdivision of geology but instead as a field of biology or a field of its own, able to be grounded in theoretical thinking and assessed numerically. Paleontology was suggested to be educated as two separate areas: stratigraphy and paleobiology, with significant overlap and incerconnection. Throughout following decades paleobiology would expand to encompass many theoretical fields related to evolution or extinction, and become a feature of museums and universities supporting the connection between paleontology and biology. Many of the fields of paleontology can be seen as part of the study of paleobiology, and paleontologists themselves may be better referred to as paleobiologists. Evolution and paleoecology are large parts of the change towards paleobiology and major areas of study and advancements of the field. Theoretical thinking and analysis of evolution has advanced and improved applications of the fossil record. Studies of taphonomy, evolutionary paleoecology, diversity, behavior, trace fossils, and the paleoenvironment all fall under the breadth of paleoecology. Paleobiology is able to inform on questions about the life appearances of organisms, their ways of communicating or reproducing, their growth, and how they survived and died out. Effective paleobiology requires knowledge of biological fields (evolution, genetics, systematics, evolutionary developmental biology, biogeography, ecology, biochemistry), geological fields (sedimentology, stratigraphy, Earth history, isotopes, geochemistry, taphonomy), statistics and applied math, and often even computer science. Findings and studies in biology are relevant and applicable to paleontology, and as a result the findings of paleontology become relevant to biology. The available information to study between the two fields is different, forcing paleontological studies to be more integrated while biological studies are more focused, but this is an opportunity for collaborative work. Paleoclimatology is the study of the ancient climates, and is a "paleo-science" alongside paleoecology and paleoceanography. Studies on the climate before and during the Quaternary, where direct measurements become available, are beginning to converge in scope, but the term "paleoclimatology" remains often restricted to the former. Before the identification and acceptance of plate tectonics, paleoclimatology had been applied from the observation that fossils were sometimes found where the climate was currently not suitable to that organism. Little discussion was had about the changing of the climate beyond the Last Glacial Maximum, so paleoclimatology was restricted to the climate of the Quaternary. Inconsistencies between climate-significant rocks and current geography were not able to be reconciled until plate tectonics demonstrates that climate zones were constant but the landmasses beneath them would change. Indicators of the paleoclimate could be found in certain types of rocks, which coupled with reconstructions of the paleogeography showed that climate zones in the past were roughly the same as today, with exceptions. During the time of the supercontinent Pangaea, arid regions were believed to be generally lower in latitude that at other times in the past, which would be explained by the monsoonal nature of the continent in the 1970s and the understanding that atmospheric circulation of monsoons also affected the regionality of climates. Ocean drilling of core samples from the seabed were then used to identify isotopes that could examine the proportions of oxygen and carbon dioxide over time to illustrate the warmth and coldness of ocean waters. In some sense, global paleoclimatology would not be possible without these ocean drilling programs. Numerical modelling of the paleoclimate was employed to further the field, though it struggles with the polar regions and the climate of continental interiors. Further development of paleoclimatology will likely focus on the impact to humans of the alterations to the climate that are occurring, and use information from the past to make predictions about the future. Paleoecology is a diverse field of paleontology that relates to the reconstruction of lifestyles and ecosystems of ancient life. While we know much about the evolution of life, less is understood about the interactions and behavior of organisms. The large amount of speculation involved in paleoecological interpretations means it may be disregarded at times, but a developing use of numerical and statistical techniques allows for quantitative assessments of paleoecological hypotheses. Paleoecology also investigates the long-term changing of ecologies and the balancing of chemical, biological, and physical changes of the world. Fossil animals and plant do not normally preserve in completion or in their undisturbed habitats, with scavenging, erosion, or transportation complicating their interpretation. The study of these complications from fossilization is taphonomy, which is its own significant and developing field of paleontology. The combination of reconstructions of ancient environments with the evolution of these environments over time is termed evolutionary paleoecology. Global patterns of diversity can be investigated through paleoecology, suggesting large bursts of diversification and the temporal separation of major faunas forms. However, these interpretations of changing diversity may be due to biases towards the preservation and discovery of more recent environments over older ones, where the field of taphonomy can become significant. Paleoecology has been able to identify several large-scale patterns in evolution and different faunas. It has been interpreted that communities living nearshore exhibit earlier diversification before spreading to offshore environments, or that tropical latitudes exhibit greater diversification. A largely detritus-feeding Cambrian fauna appears to be replaced by a suspension-feeding Paleozoic fauna, before itself being replaced by a modern fauna of marine invertebrates, though these faunas and their distinctiveness have also been questioned. Some communities show very little modification over time in a form of statis with stable composition, which changes during brief periods of turnover before stabilizing again. Competition and coevolution driving evolution may be studied through the fossil record, as well as predation and other forms of species interactions. The study of trace fossils, ichnology, also related to paleoecology as the study of fossils arising from behavioral patterns in organisms. Paleobiogeography, paleoclimatology and conservation paleobiology are also related fields of paleoecology, with the latter in particular being relevant to policies that attempt to preserve biodiversity. Paleohistology is the study of the hard tissues of fossils, analogous to the field of histology that studies biological tissues. The field is comparatively restricted as fossils preserve only superficial tissue structure and not molecules that can be found in modern histology, but it still has a long history following the use of microscopes to study both living and extinct organisms. Fossilization changes the composition of bones and to a lesser extent teeth, though their histology can still be examined through thin sections. The first use of thin sections in studying tissues in fossils was that of Richard Owen in a set of volumes in the 1840s that included dinosaurs and pterosaurs, which was simultaneously the first large comparative study of hard tissue histology. The microscopic structure of the bones, dermal armor, and teeth of early vertebrates and fossil fish was studies soon after, though polished bone surfaces were used rather than thin sections. The hard tissue structure of these early vertebrates has been used to classify them and separate jawless vertebrates (ostracoderms) from those with jaws such as placoderms and acanthodians. Similarly, the paleohistology of tetrapods has been used as evidence of both their classifications and their function. The internal structure of bones of many tetrapods can be used to identify their age quantitatively through the count of growth arrest lines. Paleohistology combines structural knowledge with functional interpretations and evolutionary processes to help understand evolution. Paleopathology is the study of ancient disease, with the clarification that "disease" is not limited to pathogens but also any other impairments that can impact health. Though paleopathology is most often discussed in the context of archaeology and human history, it has also included the study of pathologies in any fossil organism since the word was first introduced by Robert Schufeldt in 1892. It is important to separate pathological conditions from alterations that have arisen due to taphonomy, and from that distinction modern diagnostic techniques can be used to interpret the causes and impacts of pathologies in fossil organisms. Biomolecular studies have been able to isolate genetic material in fossil animals and humans to identify specific pathogens, and questioning the strength of these identifications has led to re-evaluations of the history of disease in humans and a more nuanced approach towards the study of disease in humans. Multiple factors can cause skeletal lesions that preserve well in fossils and it can be difficult to distinguish these causes due to not being able to confidently identify causes of mortality and predispositions for vulnerability. Most of the focus of paleopathology remains on human disease, though the field of animal paleopathology emerged in 1999 and expanded to cover much of the same scope of studies as human paleopathology. Specific studies into the stress fractures in the bones of dinosaurs have used their presence and distribution to identify the activity levels of the impacted animals such as running, migrating, or restraining prey. Paleophysiology is the study of how ancient life coped with its chemical and physical surroundings. Much is known about physiological changes on a short time scale, but less so about long-term responses including genetic modification. Paleophysiological analysis can investigate how species evolved or went extinct from gradual or rapid environmental change and apply that to modern scenarios to predict responses in the future. Past geological records can be found that resemble those predicted for the future. Extinctions of ancient organisms tend to be selective to certain traits like metabolic rate, temperature tolerance, photosynthesis and homeostasis, but much is not yet understood about the physiology of ancient organisms. The most useful tool for assessing paleophysiology is through the studies of "living fossils" that has presumably changed very little physiologically over long periods of time and therefor can be used to indicate paleophysiological conditions. It remains largely unknown how calcifying organisms built robust skeletons at times when atmospheric carbon dioxide levels were high, but the understanding of this process can be applicable to current rising carbon dioxide levels. Similar work may explain how photosynthetic corals and reefs can exist in times of higher acidity and temperatures as in the past. Plants respond to changes in temperature, precipitation, soil quality, and atmospheric gas composition, which can be seen in their fossils. Fossils offer a large array of phenotypes and physiologies that are rare or absent in modern biotas making it possible to assess adaptations that are not found in living species. Paleoichnology is the study of trace fossils, which can display interactions between organisms or other aspects of behavior. Common trace fossils are the burrows of bivalves or worms in shallow water, feeding traces on the deep ocean floor, and the footprints of dinosaurs and other animals in mud and sand beside bodies of water. The description of dinosaur tracks goes back to the early 19th century, but larger discussions about paleoichnology and its uses came with the reidentification of supposed plant fossils as invertebrate trackways in the 1880s to 1920s, where modern analogues were introduced to interpret these trace fossils. Advancements by Adolf Seilacher in the 1960s identified the shortcomings of ichnology: trace fossils were limited in their ability to establish the paleoenvironment, and as they lacked a consistent naming scheme it was difficult to classify and compare trace fossils. Seilacher expanded upon ichnotaxonomy as a way to classify trace fossils according to the behavior that caused them allowing the identification of sedimentary or environmental contexts. From this, ichnotaxonomy differentiates between trace fossils created by tracks, burrows or borings, excrement, and other types of behaviours, rather than describing the organism that created them. One animal can make many different kinds of traces, and one trace can be made my many different kinds of animals. Footprints made by vertebrates can often be compared more with the organism that could have created them, but this identification is not definitive and can be reinterpreted over time. Different kinds of trace fossils can also be dependent on the type of sediment the organisms were interacting with, with feeding traces on the ocean floor fossilizing differently over different substrates, and trackways of vertebrates being able to be followed across distances. The understanding that trace fossils directly correlate to sediments means that they can be used as indicators of environment types, termed ichnofacies and paleosols. In rare cases trace fossils can also be preserved alongside body fossils, such as the dinosaur Oryctodromeus that is the first to show definitive evidence of burrowing behavior as its body fossils were found buried within a fossilized burrow. Trace fossils are able to be used as markers of biochronology and biogeography for correlation, and some such as coprolites can be used to understand the diets, diseases, parasites, or climates of the organisms that created them. Some trace fossils show evidence of gregariousness in animals travelling together in the same direction or congregating at a site, while others can show pathologies in the form of uneven gaits or pathologic foot impressions. Trackways of footprints can even be used to estimate the size and speed of their creators and their courtship and nesting behaviors. Taphonomy is the field of study of the process of fossilization and the processes that occur between burial and discovery. The term taphonomy was introduced in 1940 by Ivan Yefremov as a new branch of paleontology, though the consideration of how an organism becomes a fossil predates his work. Taphonomy did not gain prominence as a field until the 1960s when it became important to consider how fossilized deposits relate to their original ecosystems, and the incompleteness of the fossil record became important for evolutionary theories such as punctuated equilibrium. Taphonomic studies of this time involved experimentations to see how the properties of water can transport, sort, or bury bones. It is unlikely that an organism will become a fossil after death, as many factors can damage or destroy both soft and hard tissues before they are buried. The hardest parts of an organism, such as shells or skeletons, are the most likely to survive to be buried and fossilized, though in rare cases soft tissues can be preserved as well. If a dead organism is buried immediately, and particularly in an anaerobic environment where decay is slowed or stopped, a complete body fossil including both soft and hard tissues may be formed, but even then different chemical or geological processes can alter the fossil, through the mineralization of organic material, or the forming of concretions around them. When not buried immediately, many different taphonomic processes can be involved in the completeness and type of preservation. The transport of organisms from their original position can result in disarticulation or the incompleteness of material, and exposure to scavengers or the surrounding environment can result in decay, fragmentation, or abrasion. After burial the rock containing fossils may be flattened geologically or deformed by the distortion of metamorphic activity. Plants can commonly be fossilized as layers of carbon where all soluble elements of the plant have been removed, and large accumulations of these carbonaceous materials may be transformed into coal seams. Many filters influence the preservation and recovery of fossils, all of which impact the completeness of the fossil record. Common organisms in an environment, that lived around shallow bodies of water with little natural erosion is more likely to be preserved, and after preservation is more likely to be discovered if the rock does not undergo severe metamorphosis, is moved to the surface geologically, and is in a location where it can be exposed to humans. Nearly every paleobiological study incorporates a taphonomic assessment and recognizes biases in the fossil record that can impact their reconstructions. Cultural significance Paleontology is one of the most high profile of the sciences. Discoveries, especially concerning dinosaurs or human evolution, are commonly reported in the mass media, with only astrophysics and global health comparable in the level of press attention. Prehistoric life is inspiration for toys, television and films, computer games, and attractions in tourism. Environments and organisms from the deep past are some of the most familiar concepts drawn from modern science, such as the dinosaurs Tyrannosaurus, Triceratops and Brontosaurus, early humans like the Neanderthal and Homo floresiensis, extinct megafauna like mammoths and sabre-toothed cats, and invertebrates like trilobites and ammonites. Paleontology academically is not a particularly well-financed field of science; the operational budget of the American Museum of Natural History in 2021 was $178 million while the budget of the 2018 film Jurassic World: Fallen Kingdom was $516.1 million. The influence of paleontology in public consciousness may be due to a number of causes such as the mystery, the immense scale of time, the size of some organisms, or the similarities between myths of dragons and giants and their representation in extinct faunas. Paleontologists draw from public funding and use appeals to gain sponsorships, but the public aspect also overshadows some portions of the field to the benefit of others. There is an overwhelming focus in paleontology on the study of dinosaurs or specific geographical regions, with the most iconic taxa almost exclusively coming from the late 19th and early 20th century excavations in North America. The marketing to children of paleontological items can make the field be regarded as "childish" and undermine the utility of the science in popular consciousness. Public perception of paleontology goes back to mythological interpretations of fossils' discovery by numerous indigenous peoples of many continents. Traditional Chinese medicine made use of Pleistocene mammal fossils as "dragon bones" or "dragon teeth"; indigenous peoples of Australia and North America made reference to landforms and fossils; and fossils have been interpreted as Nephilim, mentioned in the Book of Genesis, by European and North American Christianity. Early reconstructions of deep time following the foundation of paleontology saw paleoartistic reconstructions of past ecosystems, including the creation of the Crystal Palace Dinosaurs sculptures and landscaping in the 1850s under the direction of Benjamin Waterhouse Hawkins. Hawkins would also create the first free-standing skeletal mount of a dinosaur in the 1860s: Hadrosaurus at the Academy of Natural Sciences in Philadelphia. The Bone Wars between American paleontologists Othniel Charles Marsh and Edward Drinker Cope in the late 19th century engaged with the media at the time, and has since been used as a common popular narrative of paleontology through novels, comics, popular books, and even a musical. Following Marsh and Cope, a second American dinosaur rush occurred at the start of the 20th century when new museums and institutions aimed to excavate and display the highest-quality dinosaur fossils, accompanied by paleoart, news media, and exchanges with overseas institutions. This exploitation for popular appeal also intertwined paleontology of the time with imperialism, as fossils from Africa, Asia, and South America were excavated and taken by North American and European institutions. Further public engagement of paleontology has taken the form of fictional novels and films focused on paleontology and dinosaurs, beginning with stone-age Europeans in stories of the 1890s, but notably with the publication of The Lost World by Arthur Conan Doyle in 1912. Paleontology would be characterized by many tropes in the 1920s to 1940s, including film adaptation of the book as well as King Kong and Fantasia. Popular representations of paleontology declined coinciding with the Cold War, but resurged in the 1970s with numerous popular works such as The Dinosaur Heresies by paleontologist Robert Bakker and papers by John Ostrom that reframed dinosaurs as active animals in a time termed the "dinosaur renaissance". The most significant establishment of paleontology in public was in the 1990s with the publications of the Jurassic Park novel by Michael Crichton and the subsequent Steven Spielberg film, where the story frames warmings about scientific development and genetic technology. The expansion of interest in paleontology has been met with the creation of new institutions globally to study and preserve fossils, but the focus since the Jurassic Park works has been on dinosaurs. New media have risen to paleontological blogging and podcasts and a greater online presence of those in the field. Conjectural forms of paleoart have arisen that engage with new science, and the boundaries between an artist, hobbyist, and professional have blurred. Paleontology has significant amounts of public outreach to drive its engagement and maintain its presence in the public sphere, and this public significance has in turn led to additional resources, recognition, and funding for the science. References Further reading External links |
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