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[SOURCE: https://en.wikipedia.org/wiki/Great_Filter] | [TOKENS: 1770] |
Contents Great Filter The Great Filter is an idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox. The main conclusion of the Great Filter is that there is an inverse correlation between the probability that other life could evolve to the present stage in which humanity is, and the chances of humanity to survive in the future. The concept originates in Robin Hanson's argument that the failure to find any extraterrestrial civilizations in the observable universe implies that something is wrong with one or more of the arguments (from various scientific disciplines) that the appearance of advanced intelligent life is probable; this observation is conceptualized in terms of a "Great Filter" which acts to reduce the great number of sites where intelligent life might arise to the tiny number of intelligent species with advanced civilizations actually observed (currently just one: human). This probability threshold, which could lie in the past or following human extinction, might work as a barrier to the evolution of intelligent life, or as a high probability of self-destruction. The main conclusion of this argument is that the more probable it is that other life could evolve to the present stage in which humanity is, the bleaker the future chances of humanity probably are. The idea was first proposed in an online essay titled "The Great Filter – Are We Almost Past It?". The first version was written in August 1996 and the article was last updated on September 15, 1998[update]. Hanson's formulation has received recognition in several published sources discussing the Fermi paradox and its implications. Main argument There is no reliable evidence that aliens have visited Earth; we have observed no intelligent extraterrestrial life with current technology, nor has SETI found any transmissions from other civilizations. The Universe, apart from the Earth, seems "dead"; Hanson states: Our planet and solar system, however, don't look substantially colonized by advanced competitive life from the stars, and neither does anything else we see. To the contrary, we have had great success at explaining the behavior of our planet and solar system, nearby stars, our galaxy, and even other galaxies, via simple "dead" physical processes, rather than the complex purposeful processes of advanced life. Life is expected to expand to fill all available niches. With technology such as self-replicating spacecraft, these niches would include neighboring star systems and even, on longer time scales which are still small compared to the age of the universe, other galaxies. Hanson notes, "If such advanced life had substantially colonized our planet, we would know it by now." With no evidence of intelligent life in places other than Earth, it appears that the process of starting with a star and ending with "advanced explosive lasting life" must be unlikely. This implies that at least one step in this process must be improbable. Hanson's list, while incomplete, describes the following nine steps in an "evolutionary path" that results in the colonization of the observable universe: According to the Great Filter hypothesis, at least one of these steps—if the list were complete—must be improbable. If it is not an early step (i.e., in the past), then the implication is that the improbable step lies in the future and humanity's prospects of reaching step 9 (interstellar colonization) are still bleak. If the past steps are likely, then many civilizations would have developed to the current level of the human species. However, none appear to have made it to step 9, or the Milky Way would be full of colonies. So perhaps step 9 is the unlikely one, and the only things that appear likely to keep humanity from step 9 are some sort of catastrophe, an underestimation of the impact of procrastination as technology increasingly unburdens existence, or resource exhaustion leading to the impossibility of making the step due to consumption of the available resources (for example highly constrained energy resources). So by this argument, finding multicellular life on Mars (provided it evolved independently) would be bad news, since it would imply steps 2–6 are easy, and hence only 1, 7, 8 or 9 (or some unknown step) could be the big problem. Although steps 1–8 have occurred on Earth, any one of these may be unlikely. If the first seven steps are necessary preconditions to calculating the likelihood (using the local environment) then an anthropically biased observer can infer nothing about the general probabilities from its (pre-determined) surroundings. In a 2020 paper, Jacob Haqq-Misra, Ravi Kumar Kopparapu, and Edward Schwieterman argued that current and future telescopes searching for biosignatures in the ultraviolet to near-infrared wavelengths could place upper bounds on the fraction of planets in the galaxy that host life. Meanwhile, the evolution of telescopes that can detect technosignatures at mid-infrared wavelengths could provide insights into the Great Filter. They say that if planets with technosignatures are abundant, then this can increase confidence that the Great Filter is in the past. On the other hand, if finding that life is commonplace while technosignatures are absent, then this would increase the likelihood that the Great Filter lies in the future. Recently, paleobiologist Olev Vinn has suggested that the great filter may exist between steps 8 and 9 due to inherited behavior patterns (IBP) that initially occur in all intelligent biological organisms. These IBPs are incompatible with conditions prevailing in technological civilizations and could inevitably lead to the self-destruction of civilization in multiple ways. In a specific formulation named the "Berserker hypothesis", a filter exists between steps 8 and 9 in which each civilization is destroyed by a lethal Von Neumann probe created by a more advanced civilization. Responses There are many alternative scenarios that might allow for the evolution of intelligent life to occur multiple times without either catastrophic self-destruction or glaringly visible evidence. These are possible resolutions to the Fermi paradox: "They do exist, but we see no evidence". Other ideas include: it is too expensive to spread physically throughout the galaxy; Earth is purposely isolated; it is dangerous to communicate and hence civilizations actively hide, among others. Astrobiologists Dirk Schulze-Makuch and William Bains, reviewing the history of life on Earth, including convergent evolution, concluded that transitions such as oxygenic photosynthesis, the eukaryotic cell, multicellularity, and tool-using intelligence are likely to occur on any Earth-like planet given enough time. They argue that the Great Filter may be abiogenesis, the rise of technological human-level intelligence, or an inability to settle other worlds because of self-destruction or a lack of resources. Astronomer Seth Shostak of the SETI Institute argues that one can postulate a galaxy filled with intelligent extraterrestrial civilizations that have failed to colonize Earth. Perhaps the aliens lacked the intent and purpose to colonize or depleted their resources, or maybe the galaxy is colonized but in a heterogeneous manner, or the Earth could be located in a "galactic backwater". Although absence of evidence generally is only weak evidence of absence, the absence of extraterrestrial megascale engineering projects, for example, could be attributed to the Great Filter. The lack of perceptible evidence for extraterrestrial civilizations is interpreted by some as suggesting that one of the steps leading to intelligent life is unlikely. According to Shostak: This is, of course, a variant on the Fermi paradox: We don't see clues to widespread, large-scale engineering, and consequently we must conclude that we're alone. But the possibly flawed assumption here is when we say that highly visible construction projects are an inevitable outcome of intelligence. It could be that it's the engineering of the small, rather than the large, that is inevitable. This follows from the laws of inertia (smaller machines are faster, and require less energy to function) as well as the speed of light (small computers have faster internal communication). It may be—and this is, of course, speculation—that advanced societies are building small technology and have little incentive or need to rearrange the stars in their neighborhoods, for instance. They may prefer to build nanobots instead. It should also be kept in mind that, as Arthur C. Clarke said, truly advanced engineering would look like magic to us—or be unrecognizable altogether. By the way, we've only just begun to search for things like Dyson spheres, so we can't really rule them out. See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Rare_Earth_hypothesis] | [TOKENS: 7619] |
Contents Rare Earth hypothesis In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity, such as sexually reproducing, multicellular organisms on Earth, and subsequently human intelligence, required an improbable combination of astrophysical and geological events and circumstances. According to the hypothesis, complex extraterrestrial life is an improbable phenomenon and likely to be rare throughout the universe as a whole. The term "Rare Earth" originates from Rare Earth: Why Complex Life Is Uncommon in the Universe (2000), a book by Peter Ward, a geologist and paleontologist, and Donald E. Brownlee, an astronomer and astrobiologist, both faculty members at the University of Washington. In the 1970s and 1980s, Carl Sagan and Frank Drake, among others, argued that Earth is a typical rocky planet in a typical planetary system, located in a non-exceptional region of a common galaxy, now known to be a barred spiral galaxy. From the principle of mediocrity (extended from the Copernican principle), they argued that the evolution of life on Earth, including human beings, was also typical, and therefore that the universe teems with complex life. In contrast, Ward and Brownlee argue that planets which have all the requirements for complex life are not typical at all but actually exceedingly rare. Fermi paradox There is no reliable or reproducible evidence that extraterrestrial organisms of any kind have visited Earth. No transmissions or evidence of intelligent life have been detected or observed anywhere other than Earth in the Universe. This runs counter to the knowledge that the Universe is filled with a very large number of planets, some of which likely hold the conditions hospitable for life. Life typically expands until it fills all available niches. These contradictory facts form the basis for the Fermi paradox, of which the Rare Earth hypothesis is one proposed solution. Requirements for complex life The Rare Earth hypothesis argues that the evolution of biological complexity anywhere in the universe requires the coincidence of a large number of fortuitous circumstances, including, among others, a galactic habitable zone; a central star and planetary system having the requisite character (i.e. a circumstellar habitable zone); a terrestrial planet of the right mass; the advantage of one or more gas giant guardians like Jupiter and possibly a large natural satellite to shield the planet from frequent impact events; conditions needed to ensure the planet has a magnetosphere and plate tectonics; a chemistry similar to that present in the Earth's lithosphere, atmosphere, and oceans; the influence of periodic "evolutionary pumps" such as massive glaciations and bolide impacts; and whatever factors may have led to the emergence of eukaryotic cells, sexual reproduction, and the Cambrian explosion of animal, plant, and fungi phyla. The evolution of human beings and of human intelligence may have required yet further specific events and circumstances, all of which are extremely unlikely to have happened were it not for the Cretaceous–Paleogene extinction event 66 million years ago removing dinosaurs as the dominant terrestrial vertebrates. In order for a small rocky planet to support complex life, Ward and Brownlee argue, the values of several variables must fall within narrow ranges. The universe is so vast that it might still contain many Earth-like planets, but if such planets exist, they are likely to be separated from each other by many thousands of light-years. Such distances may preclude communication among any intelligent species that may evolve on such planets, which would solve the Fermi paradox which wonders: if extraterrestrial aliens are common, why aren't they obvious? Rare Earth suggests that much of the known universe, including large parts of the Milky Way galaxy, are "dead zones" unable to support complex life. Those parts of a galaxy where complex life is possible make up the galactic habitable zone, which is primarily characterized by distance from the Galactic Center. Item #1 rules out the outermost reaches of a galaxy; #2 and #3 rule out galactic inner regions. Hence a galaxy's habitable zone may be a relatively narrow ring of adequate conditions sandwiched between its uninhabitable center and outer reaches. Also, a habitable planetary system must maintain its favorable location long enough for complex life to evolve. A star with an eccentric (elliptical or hyperbolic) galactic orbit will pass through some spiral arms, unfavorable regions of high star density; thus a life-bearing star must have a galactic orbit that is nearly circular, with a close synchronization between the orbital velocity of the star and of the spiral arms. This further restricts the galactic habitable zone within a fairly narrow range of distances from the Galactic Center. Lineweaver et al. calculate this zone to be a ring 7 to 9 kiloparsecs in radius, including no more than 10% of the stars in the Milky Way, about 20 to 40 billion stars. Gonzalez et al. would halve these numbers; they estimate that at most 5% of stars in the Milky Way fall within the galactic habitable zone. Approximately 77% of observed galaxies are spiral, two-thirds of all spiral galaxies are barred, and more than half, like the Milky Way, exhibit multiple arms. According to Rare Earth, our own galaxy is unusually quiet and dim (see below), representing just 7% of its kind. Even so, this would still represent more than 200 billion galaxies in the known universe. The Milky Way galaxy also appears unusually favorable in suffering fewer collisions with other galaxies over the last 10 billion years, which can cause more supernovae and other disturbances. Also, the Milky Way's central black hole seems to have neither too much nor too little activity. The orbit of the Sun around the center of the Milky Way is indeed almost perfectly circular, with a period of 226 Ma (million years), closely matching the rotational period of the galaxy. However, the majority of stars in barred spiral galaxies populate the spiral arms rather than the halo and tend to move in gravitationally aligned orbits, so there is little that is unusual about the Sun's orbit. While the Rare Earth hypothesis predicts that the Sun should rarely, if ever, have passed through a spiral arm since its formation, astronomer Karen Masters has calculated that the orbit of the Sun takes it through a major spiral arm approximately every 100 million years. Some researchers have suggested that several mass extinctions do indeed correspond with previous crossings of the spiral arms. The terrestrial example suggests that complex life requires liquid water, the maintenance of which requires an orbital distance neither too close nor too far from the central star, another scale of habitable zone or Goldilocks principle. The habitable zone varies with the star's type and age. For advanced life, the star must also be highly stable, which is typical of middle star life, about 4.6 billion years old. Proper metallicity and size are also important to stability. The Sun has a low (0.1%) luminosity variation. To date, no solar twin star, with an exact match of the Sun's luminosity variation, has been found, though some come close. The star must also have no stellar companions, as in binary systems, which would disrupt the orbits of any planets. Estimates suggest 50% or more of all star systems are binary. Stars gradually brighten over time and it takes hundreds of millions or billions of years for animal life to evolve. The requirement for a planet to remain in the habitable zone even as its boundaries move outwards over time restricts the size of what Ward and Brownlee call the "continuously habitable zone" for animals. They cite a calculation that it is very narrow, within 0.95 and 1.15 astronomical units (one AU is the distance between the Earth and the Sun), and argue that even this may be too large because it is based on the whole zone within which liquid water can exist, and water near boiling point may be much too hot for animal life. The liquid water and other gases available in the habitable zone bring the benefit of the greenhouse effect. Even though the Earth's atmosphere contains a water vapor concentration from 0% (in arid regions) to 4% (in rainforest and ocean regions) and – as of November 2022 – only 417.2 parts per million of CO2, these small amounts suffice to raise the average surface temperature by about 40 °C, with the dominant contribution being due to water vapor. All known life requires the complex chemistry of metallic elements. The absorption spectrum of a star reveals the presence of metals within, and studies of stellar spectra reveal that many, perhaps most, stars are poor in metals. Because heavy metals originate in supernova explosions, metallicity increases in the universe over time. Low metallicity characterizes the early universe: globular clusters and other stars that formed when the universe was young, stars in most galaxies other than large spirals, and stars in the outer regions of all galaxies. Metal-rich central stars capable of supporting complex life are therefore believed to be most common in the less dense regions of the larger spiral galaxies—where radiation also happens to be weak. Rare Earth proponents argue that a planetary system capable of sustaining complex life must be structured more or less like the Solar System, with small, rocky inner planets and massive outer gas giants. Without the protection of such "celestial vacuum cleaner" planets, such as Jupiter, with strong gravitational pulls, other planets would be subject to more frequent catastrophic asteroid collisions. An asteroid only twice the size of the one which caused the Cretaceous–Paleogene extinction might have wiped out all complex life. Observations of exoplanets have shown that arrangements of planets similar to the Solar System are rare. Most planetary systems have super-Earths, several times larger than Earth, close to their star, whereas the Solar System's inner region has only a few small rocky planets and none inside Mercury's orbit. Only 10% of stars have giant planets similar to Jupiter and Saturn, and those few rarely have stable, nearly circular orbits distant from their star. Konstantin Batygin and colleagues argue that these features can be explained if, early in the history of the Solar System, Jupiter and Saturn drifted towards the Sun, sending showers of planetesimals towards the super-Earths which sent them spiralling into the Sun, and ferrying icy building blocks into the terrestrial region of the Solar System which provided the building blocks for the rocky planets. The two giant planets then drifted out again to their present positions. In the view of Batygin and his colleagues: "The concatenation of chance events required for this delicate choreography suggest that small, Earth-like rocky planets – and perhaps life itself – could be rare throughout the cosmos." Rare Earth proponents argue that a gas giant also must not be too close to a body where life is developing. Close placement of one or more gas giants could disrupt the orbit of a potential life-bearing planet, either directly or by drifting into the habitable zone. Newtonian dynamics can produce chaotic planetary orbits, especially in a system having large planets at high orbital eccentricity. The need for stable orbits rules out stars with planetary systems that contain large planets with orbits close to the host star (called "hot Jupiters"). It is believed that hot Jupiters have migrated inwards to their current orbits. In the process, they would have catastrophically disrupted the orbits of any planets in the habitable zone. To exacerbate matters, hot Jupiters are much more common orbiting F and G class stars. The Rare Earth hypothesis argues that life requires terrestrial planets like Earth, and since gas giants lack such a surface, that complex life cannot arise there. A planet that is too small cannot maintain much atmosphere, rendering its surface temperature low and variable and oceans impossible. A small planet will also tend to have a rough surface, with large mountains and deep canyons. The core will cool faster, and plate tectonics will be brief or entirely absent. On Earth heat loss is balanced by heat production from radioactive decay, resulting in a thin crust and plate tectonics. On a significantly larger planet, heat production would exceed heat loss and Earth would probably not have developed an outer crust, making plate tectonics and life impossible. Rare Earth proponents argue that plate tectonics and a strong magnetic field are essential for biodiversity, global temperature regulation, and the carbon cycle. The lack of mountain chains elsewhere in the Solar System is evidence that Earth is the only body which now has plate tectonics, and thus the only one capable of supporting life. Plate tectonics depend on the right chemical composition and a long-lasting source of heat from radioactive decay. Continents must be made of less dense felsic rocks that "float" on underlying denser mafic rock. Taylor emphasizes that tectonic subduction zones require the lubrication of oceans of water. Plate tectonics also provide a means of biochemical cycling. Plate tectonics and, as a result, continental drift and the creation of separate landmasses would create diversified ecosystems and biodiversity, one of the strongest defenses against extinction. An example of species diversification and later competition on Earth's continents is the Great American Interchange. North and Middle America drifted into South America at around 3.5 to 3 Ma. The fauna of South America had already evolved separately for about 30 million years, since Antarctica separated, but, after the merger, many species were wiped out, mainly in South America, by competing North American animals. The Moon is unusual because the other rocky planets in the Solar System either have no satellites (Mercury and Venus), or only relatively tiny satellites which are probably captured asteroids (Mars). After Charon, the Moon is also the largest natural satellite in the Solar System relative to the size of its parent body, being 27% the size of Earth. The giant-impact theory hypothesizes that the Moon resulted from the impact of a roughly Mars-sized body, dubbed Theia, with the young Earth. This giant impact also gave the Earth its axial tilt (inclination) and velocity of rotation. Rapid rotation reduces the daily variation in temperature and makes photosynthesis viable. The Rare Earth hypothesis further argues that the axial tilt cannot be too large or too small (relative to the orbital plane). A planet with a large tilt will experience extreme seasonal variations in climate. A planet with little or no tilt will lack the stimulus to evolution that climate variation provides.[citation needed] In this view, the Earth's tilt is "just right". The gravity of a large satellite also stabilizes the planet's tilt; without this effect, the variation in tilt would be chaotic, probably making complex life forms on land impossible. If the Earth had no Moon, the ocean tides resulting solely from the Sun's gravity would be only half that of the lunar tides. A large satellite gives rise to tidal pools, which may be essential for the formation of complex life, though this is far from certain. A large satellite also increases the likelihood of plate tectonics through the effect of tidal forces on the planet's crust.[citation needed] The impact that formed the Moon may also have initiated plate tectonics, without which the continental crust would cover the entire planet, leaving no room for oceanic crust.[citation needed] It is possible that the large-scale mantle convection needed to drive plate tectonics could not have emerged if the crust had a uniform composition. A further theory indicates that such a large moon may also contribute to maintaining a planet's magnetic shield by continually acting upon a metallic planetary core as dynamo, thus protecting the surface of the planet from charged particles and cosmic rays, and helping to ensure the atmosphere is not stripped over time by solar winds.[citation needed] A terrestrial planet must be the right size, like Earth and Venus, in order to retain an atmosphere. On Earth, once the giant impact of Theia thinned Earth's atmosphere, other events were needed to make the atmosphere capable of sustaining life. The Late Heavy Bombardment reseeded Earth with water lost after the impact of Theia. The development of an ozone layer generated a protective shield against ultraviolet (UV) sunlight. Nitrogen and carbon dioxide are needed in a correct ratio for life to form. Lightning is needed for nitrogen fixation. The gaseous carbon dioxide needed for life comes from sources such as volcanoes and geysers. Carbon dioxide is preferably needed at relatively low levels (currently at approximately 400 ppm on Earth) because at high levels it is poisonous. Precipitation is needed to have a stable water cycle. A proper atmosphere must reduce diurnal temperature variation. Regardless of whether planets with similar physical attributes to the Earth are rare or not, some argue that life tends not to evolve into anything more complex than simple bacteria without being provoked by rare and specific circumstances. Biochemist Nick Lane argues that simple cells (prokaryotes) emerged soon after Earth's formation, but since almost half the planet's life had passed before they evolved into complex ones (eukaryotes), all of whom share a common ancestor, this event can only have happened once. According to some views, prokaryotes lack the cellular architecture to evolve into eukaryotes because a bacterium expanded up to eukaryotic proportions would have tens of thousands of times less energy available to power its metabolism. Two billion years ago, one simple cell incorporated itself into another, multiplied, and evolved into mitochondria that supplied the vast increase in available energy that enabled the evolution of complex eukaryotic life. If this incorporation occurred only once in four billion years or is otherwise unlikely, then life on most planets remains simple. An alternative view is that the evolution of mitochondria was environmentally triggered, and that mitochondria-containing organisms appeared soon after the first traces of atmospheric oxygen. The evolution and persistence of sexual reproduction is another mystery in biology. The purpose of sexual reproduction is unclear, as in many organisms it has a 50% cost (fitness disadvantage) in relation to asexual reproduction. Mating types (types of gametes, according to their compatibility) may have arisen as a result of anisogamy (gamete dimorphism), or the male and female sexes may have evolved before anisogamy. It is also unknown why most sexual organisms use a binary mating system, and why some organisms have gamete dimorphism. Charles Darwin was the first to suggest that sexual selection drives speciation; without it, complex life would probably not have evolved. While life on Earth is regarded to have spawned relatively early in the planet's history, the evolution from multicellular to intelligent organisms took around 800 million years. Civilizations on Earth have existed for about 12,000 years, and radio communication reaching space has existed for little more than 100 years. Relative to the age of the Solar System (~4.57 Ga) this is a short time, in which extreme climatic variations, super volcanoes, and large meteorite impacts were absent. These events would severely harm intelligent life, as well as life in general. For example, the Permian-Triassic mass extinction, caused by widespread and continuous volcanic eruptions in an area the size of Western Europe, led to the extinction of 95% of known species around 251.2 Ma ago. About 65 million years ago, the Chicxulub impact at the Cretaceous–Paleogene boundary (~65.5 Ma) on the Yucatán peninsula in Mexico led to a mass extinction. Rare Earth equation The following discussion is adapted from Cramer. The Rare Earth equation is Ward and Brownlee's riposte to the Drake equation. It calculates N {\displaystyle N} , the number of Earth-like planets in the Milky Way having complex life forms, as: where: We assume N ∗ ⋅ n e = 5 ⋅ 10 11 {\displaystyle N^{*}\cdot n_{e}=5\cdot 10^{11}} . The Rare Earth hypothesis can then be viewed as asserting that the product of the other nine Rare Earth equation factors listed below, which are all fractions, is no greater than 10−10 and could plausibly be as small as 10−12. In the latter case, N {\displaystyle N} could be as small as 0 or 1. Ward and Brownlee do not actually calculate the value of N {\displaystyle N} , because the numerical values of quite a few of the factors below can only be conjectured. They cannot be estimated simply because we have but one data point: the Earth, a rocky planet orbiting a G2 star in a quiet suburb of a large barred spiral galaxy, and the home of the only intelligent species we know; namely, ourselves. Lammer, Scherf et al. define Earth-like habitats (EHs) as rocky exoplanets within the habitable zone of complex life (HZCL) on which Earth-like N2-O2-dominated atmospheres with minor amounts of CO2 can exist. They estimate the maximum number of EHs in the Milky Way as 2.54 − 2.48 + 71.64 ⋅ 10 5 {\displaystyle {2.54}_{-2.48}^{+71.64}\cdot 10^{5}} , with the actual number of EHs being possibly much less than that. This would reduce the Rare Earth equation to: The Rare Earth equation, unlike the Drake equation, does not factor the probability that complex life evolves into intelligent life that discovers technology. Barrow and Tipler review the consensus among such biologists that the evolutionary path from primitive Cambrian chordates, e.g., Pikaia to Homo sapiens, was a highly improbable event. For example, the large brains of humans have marked adaptive disadvantages, requiring as they do an expensive metabolism, a long gestation period, and a childhood lasting more than 25% of the average total life span. Other improbable features of humans include: Advocates Writers who support the Rare Earth hypothesis: Criticism Cases against the Rare Earth hypothesis take various forms. The hypothesis concludes, more or less, that complex life is rare because it can evolve only on the surface of an Earth-like planet or on a suitable satellite of a planet. Some biologists, such as Jack Cohen, believe this assumption too restrictive and unimaginative; they see it as a form of circular reasoning.[page needed] According to David Darling, the Rare Earth hypothesis is neither hypothesis nor prediction, but merely a description of how life arose on Earth. In his view, Ward and Brownlee have done nothing more than select the factors that best suit their case. What matters is not whether there's anything unusual about the Earth; there's going to be something idiosyncratic about every planet in space. What matters is whether any of Earth's circumstances are not only unusual but also essential for complex life. So far we've seen nothing to suggest there is. Critics also argue that there is a link between the Rare Earth hypothesis and the unscientific idea of intelligent design. An increasing number of extrasolar planet discoveries are being made, with 6,128 planets in 4,584 planetary systems known as of 30 October 2025. Rare Earth proponents argue life cannot arise outside Sun-like systems, due to tidal locking and ionizing radiation outside the F7–K1 range. However, some exobiologists have suggested that stars outside this range may give rise to life under the right circumstances; this possibility is a central point of contention to the theory because these late-K and M category stars make up about 82% of all hydrogen-burning stars. Current technology limits the testing of important Rare Earth criteria: surface water, tectonic plates, a large moon and biosignatures are currently undetectable. Though planets the size of Earth are difficult to detect and classify, scientists now think that rocky planets are common around Sun-like stars. The Earth Similarity Index (ESI) of mass, radius and temperature provides a means of measurement, but falls short of the full Rare Earth criteria. Some argue that Rare Earth's estimates of rocky planets in habitable zones ( n e {\displaystyle n_{e}} in the Rare Earth equation) are too restrictive. James Kasting cites the Titius–Bode law to contend that it is a misnomer to describe habitable zones as narrow when there is a 50% chance of at least one planet orbiting within one. In 2013, astronomers using the Kepler space telescope's data estimated that about one-fifth of G-type and K-type stars (sun-like stars and orange dwarfs) are expected to have an Earth-sized or super-Earth-sized planet (1–2 Earths wide) close to an Earth-like orbit (0.25–4 F🜨), yielding about 8.8 billion of them for the entire Milky Way Galaxy. The requirement for a system to have a Jovian planet as protector (Rare Earth equation factor f j {\displaystyle f_{j}} ) has been challenged, affecting the number of proposed extinction events (Rare Earth equation factor f m e {\displaystyle f_{me}} ). Kasting's 2001 review of Rare Earth questions whether a Jupiter protector has any bearing on the incidence of complex life. Computer modelling including the 2005 Nice model and 2007 Nice 2 model yield inconclusive results in relation to Jupiter's gravitational influence and impacts on the inner planets. A study by Horner and Jones (2008) using computer simulation found that while the total effect on all orbital bodies within the Solar System is unclear, Jupiter has caused more impacts on Earth than it has prevented. Lexell's Comet, a 1770 near miss that passed closer to Earth than any other comet in recorded history, was known to be caused by the gravitational influence of Jupiter. Ward and Brownlee argue that for complex life to evolve (Rare Earth equation factor f c {\displaystyle f_{c}} ), tectonics must be present to generate biogeochemical cycles, and predicted that such geological features would not be found outside of Earth, pointing to a lack of observable mountain ranges and subduction. There is, however, no scientific consensus on the evolution of plate tectonics on Earth. Though it is believed that tectonic motion first began around three billion years ago, by this time photosynthesis and oxygenation had already begun. Furthermore, recent studies point to plate tectonics as an episodic planetary phenomenon, and that life may evolve during periods of "stagnant-lid" rather than plate tectonic states. Recent evidence also points to similar activity either having occurred or continuing to occur elsewhere. The geology of Pluto, for example, described by Ward and Brownlee as "without mountains or volcanoes ... devoid of volcanic activity", has since been found to be quite the contrary, with a geologically active surface possessing organic molecules and mountain ranges like Tenzing Montes and Hillary Montes comparable in relative size to those of Earth, and observations suggest the involvement of endogenic processes. Plate tectonics has been suggested as a hypothesis for the Martian dichotomy, and in 2012 geologist An Yin put forward evidence for active plate tectonics on Mars. Europa has long been suspected to have plate tectonics and in 2014 NASA announced evidence of active subduction. Like Europa, analysis of the surface of Jupiter's largest moon Ganymede strike-strip faulting and surface materials of possible endogenic origin suggests that plate tectonics has also taken place there. In 2017, scientists studying the geology of Charon confirmed that icy plate tectonics also operated on Pluto's largest moon. Since 2017 several studies of the geodynamics of Venus have also found that, contrary to the view that the lithosphere of Venus is static, it is actually being deformed via active processes similar to plate tectonics, though with less subduction, implying that geodynamics are not a rare occurrence in Earth sized bodies. Kasting suggests that there is nothing unusual about the occurrence of plate tectonics in large rocky planets and liquid water on the surface as most should generate internal heat even without the assistance of radioactive elements. Studies by Valencia and Cowan suggest that plate tectonics may be inevitable for terrestrial planets Earth-sized or larger, that is, Super-Earths, which are now known to be more common in planetary systems. The hypothesis that molecular oxygen, necessary for animal life, is rare and that a Great Oxygenation Event (Rare Earth equation factor f c {\displaystyle f_{c}} ) could only have been triggered and sustained by tectonics, appears to have been invalidated by more recent discoveries. Ward and Brownlee ask "whether oxygenation, and hence the rise of animals, would ever have occurred on a world where there were no continents to erode". Extraterrestrial free oxygen has recently been detected around other solid objects, including Mercury, Venus, Mars, Jupiter's four Galilean moons, Saturn's moons Enceladus, Dione and Rhea and even the atmosphere of a comet. This has led scientists to speculate whether processes other than photosynthesis could be capable of generating an environment rich in free oxygen. Wordsworth (2014) concludes that oxygen generated other than through photodissociation may be likely on Earth-like exoplanets, and could actually lead to false positive detections of life. Narita (2015) suggests photocatalysis by titanium dioxide as a geochemical mechanism for producing oxygen atmospheres. Since Ward & Brownlee's assertion that "there is irrefutable evidence that oxygen is a necessary ingredient for animal life", anaerobic metazoa have been found that indeed do metabolise without oxygen. Spinoloricus cinziae, for example, a species discovered in the hypersaline anoxic L'Atalante basin at the bottom of the Mediterranean Sea in 2010, appears to metabolise with hydrogen, lacking mitochondria and instead using hydrogenosomes. Studies since 2015 of the eukaryotic genus Monocercomonoides that lack mitochondrial organelles are also significant as there are no detectable signs that mitochondria are part of the organism. Since then further eukaryotes, particularly parasites, have been identified to be completely absent of mitochondrial genome, such as the 2020 discovery in Henneguya zschokkei. Further investigation into alternative metabolic pathways used by these organisms appear to present further problems for the premise. Stevenson (2015) has proposed other membrane alternatives for complex life in worlds without oxygen. In 2017, scientists from the NASA Astrobiology Institute discovered the necessary chemical preconditions for the formation of azotosomes on Saturn's moon Titan, a world that lacks atmospheric oxygen. Independent studies by Schirrmeister and by Mills concluded that Earth's multicellular life existed prior to the Great Oxygenation Event, not as a consequence of it. NASA scientists Hartman and McKay argue that plate tectonics may in fact slow the rise of oxygenation (and thus stymie complex life rather than promote it). Computer modelling by Tilman Spohn in 2014 found that plate tectonics on Earth may have arisen from the effects of complex life's emergence, rather than the other way around as the Rare Earth might suggest. The action of lichens on rock may have contributed to the formation of subduction zones in the presence of water. Kasting argues that if oxygenation caused the Cambrian explosion then any planet with oxygen producing photosynthesis should have complex life. The importance of Earth's magnetic field to the development of complex life has been disputed. The origin of Earth's magnetic field remains a mystery though the presence of a magnetosphere appears to be relatively common for larger planetary mass objects as all Solar System planets larger than Earth possess one. There is increasing evidence of present or past magnetic activity in terrestrial bodies such as the Moon, Ganymede, Mercury and Mars. Without sufficient measurement present studies rely heavily on modelling methods developed in 2006 by Olson & Christensen to predict field strength. Using a sample of 496 planets such models predict Kepler-186f to be one of few of Earth size that would support a magnetosphere (though such a field around this planet has not currently been confirmed). However current recent empirical evidence points to the occurrence of much larger and more powerful fields than those found in the Solar System, some of which cannot be explained by these models. Kasting argues that the atmosphere provides sufficient protection against cosmic rays even during times of magnetic pole reversal and atmosphere loss by sputtering. Kasting also dismisses the role of the magnetic field in the evolution of eukaryotes, citing the age of the oldest known magnetofossils. The requirement of a large moon (Rare Earth equation factor f m {\displaystyle f_{m}} ) has also been challenged. Even if it were required, such an occurrence may not be as unique as predicted by the Rare Earth Hypothesis. Work by Edward Belbruno and J. Richard Gott of Princeton University suggests that giant impactors such as those that may have formed the Moon can indeed form in planetary trojan points (L4 or L5 Lagrangian point) which means that similar circumstances may occur in other planetary systems. The assertion that the Moon's stabilization of Earth's obliquity and spin is a requirement for complex life has been questioned. Kasting argues that a moonless Earth would still possess habitats with climates suitable for complex life and questions whether the spin rate of a moonless Earth can be predicted. Although the giant impact theory posits that the impact forming the Moon increased Earth's rotational speed to make a day about 5 hours long, the Moon has slowly "stolen" much of this speed to reduce Earth's solar day since then to about 24 hours and continues to do so: in 100 million years Earth's solar day will be roughly 24 hours 38 minutes (the same as Mars's solar day); in 1 billion years, 30 hours 23 minutes. Larger secondary bodies would exert proportionally larger tidal forces that would in turn decelerate their primaries faster and potentially increase the solar day of a planet in all other respects like Earth to over 120 hours within a few billion years. This long solar day would make effective heat dissipation for organisms in the tropics and subtropics extremely difficult in a similar manner to tidal locking to a red dwarf star. Short days (high rotation speed) cause high wind speeds at ground level. Long days (slow rotation speed) cause the day and night temperatures to be too extreme. Many Rare Earth proponents argue that the Earth's plate tectonics would probably not exist if not for the tidal forces of the Moon or the impact of Theia (prolonging mantle effects). The hypothesis that the Moon's tidal influence initiated or sustained Earth's plate tectonics remains unproven, though at least one study implies a temporal correlation to the formation of the Moon. Evidence for the past existence of plate tectonics on planets like Mars which may never have had a large moon would counter this argument, although plate tectonics may fade anyway before a moon is relevant to life. Kasting argues that a large moon is not required to initiate plate tectonics. Rare Earth proponents argue that simple life may be common, though complex life requires specific environmental conditions to arise. Critics consider life could arise on a moon of a gas giant, though this is less likely if life requires volcanicity. The moon must have stresses to induce tidal heating, but not so dramatic as seen on Jupiter's Io. However, the moon is within the gas giant's intense radiation belts, sterilizing any biodiversity before it can get established. Dirk Schulze-Makuch disputes this, hypothesizing alternative biochemistries for alien life. While Rare Earth proponents argue that only microbial extremophiles could exist in subsurface habitats beyond Earth, some argue that complex life can also arise in these environments. Examples of extremophile animals such as the Hesiocaeca methanicola, an animal that inhabits ocean floor methane clathrates substances more commonly found in the outer Solar System, the tardigrades which can survive in the vacuum of space or Halicephalobus mephisto which exists in crushing pressure, scorching temperatures and extremely low oxygen levels 3.6 kilometres ( 2.2 miles) deep in the Earth's crust, are sometimes cited by critics as complex life capable of thriving in "alien" environments. Jill Tarter counters the classic counterargument that these species adapted to these environments rather than arose in them, by suggesting that we cannot assume conditions for life to emerge which are not actually known. There are suggestions that complex life could arise in sub-surface conditions which may be similar to those where life may have arisen on Earth, such as the tidally heated subsurfaces of Europa or Enceladus. Ancient circumvental ecosystems such as these support complex life on Earth such as Riftia pachyptila that exist completely independent of the surface biosphere. See also References Sources Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Autonomous_System_Number] | [TOKENS: 1227] |
Contents Autonomous system (Internet) Page version status This is an accepted version of this page An autonomous system (AS) is a collection of connected Internet Protocol (IP) routing prefixes under the control of one or more network operators on behalf of a single administrative entity or domain, that presents a common and clearly defined routing policy to the Internet.: §3 Each AS is assigned an autonomous system number (ASN), for use in Border Gateway Protocol (BGP) routing. ASNs are assigned to local Internet registries (LIRs) and end-user organizations by their respective regional Internet registries (RIRs), which in turn receive blocks of ASNs for reassignment from the Internet Assigned Numbers Authority (IANA). The IANA also maintains a registry of ASNs which are reserved for private use (and should therefore not be announced to the global Internet). Originally, the definition required control by a single entity, typically an Internet service provider (ISP) or a very large organization with independent connections to multiple networks, that adhered to a single and clearly defined routing policy. In March 1996, the newer definition came into use because multiple organizations can run BGP using private ASNs to an ISP that connects all those organizations to the Internet. Even though there may be multiple autonomous systems supported by the ISP, the Internet only sees the routing policy of the ISP. That ISP must have an officially registered ASN. Until 2007, ASNs were defined as 16-bit integers, which allowed for a maximum of 65,536 assignments. Since then, the IANA has begun to also assign 32-bit AS numbers to regional Internet registries. These numbers are written preferably as simple integers, in a notation referred to as "asplain", ranging from 0 to 4,294,967,295 (hexadecimal 0xFFFF FFFF). Or, alternatively, in the form called "asdot+" which looks like x.y, where x and y are 16-bit numbers. Numbers of the form 0.y are exactly the old 16-bit AS numbers. The special 16-bit ASN 23456 ("AS_TRANS") was assigned by IANA as a placeholder for 32-bit ASN values for the case when 32-bit-ASN capable routers ("new BGP speakers") send BGP messages to routers with older BGP software ("old BGP speakers") which do not understand the new 32-bit ASNs. The first and last ASNs of the original 16-bit integers (0 and 65,535) and the last ASN of the 32-bit numbers (4,294,967,295) are reserved and should not be used by operators; AS0 is used by all five RIRs to invalidate unallocated space. ASNs 64,496 to 64,511 of the original 16-bit range and 65,536 to 65,551 of the 32-bit range are reserved for use in documentation. ASNs 64,512 to 65,534 of the original 16-bit AS range, and 4,200,000,000 to 4,294,967,294 of the 32-bit range are reserved for Private Use. The number of unique autonomous networks in the routing system of the Internet exceeded 5,000 in 1999, 30,000 in late 2008, 35,000 in mid-2010, 42,000 in late 2012, 54,000 in mid-2016 and 60,000 in early 2018. By December 2020, the number of allocated ASNs exceeded 100,000. As of 2025,[update] there are roughly 120,000 allocated ASNs. Assignment ASNs are assigned in blocks by the Internet Assigned Numbers Authority (IANA) to regional Internet registries (RIRs). The appropriate RIR then assigns ASNs to entities within its designated area from the block assigned by IANA. Entities wishing to receive an ASN must complete the application process of their RIR, LIR or upstream service provider and be approved before being assigned an ASN. Current IANA ASN assignments to RIRs can be found on the IANA website. RIRs, as part of NRO, can revoke AS numbers as part of their Internet governance abilities. There are other sources for more specific data: ASN table A complete table of available 16-bit and 32-bit ASN: Types Autonomous systems (AS) can be grouped into four categories, depending on their connectivity and operating policy. AS-SET Autonomous systems can be included in one or more AS-SETs, for example AS-SET of RIPE NCC "AS-12655" has AS1, AS2 and AS3 as its members, but AS1 is also included in other sets in ARIN (AS-INCAPSULA) and APNIC (AS-IMCL). Other AS-SET sources can be RADB, LEVEL3 (tier 1 network now called Lumen Technologies) and also ARIN has the ARIN-NONAUTH source of AS-SETs. AS-SETs are created by network operators in an Internet Routing Registry (IRR), like other route objects, and can be included in other AS-SETs and even form cycles. AS-SET names usually start with "AS-", but can also have a hierarchical name. For example, the administrator of AS 64500 may create an AS-SET called "AS64500:AS-UPSTREAMS", to avoid conflict with other similarly named AS-SETs. AS-SETs are often used to simplify management of published routing policies. A routing policy is published in the IRR using "import" and "export" (or the newer "mp-import" and "mp-export") attributes, which each contain the source or destination ASN, and the ASN imported or exported. Instead of single ASNs, AS-SETs can be referenced in these attributes, which simplifies management of complex routing policies. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Oak_(programming_language)] | [TOKENS: 320] |
Contents Oak (programming language) Oak is a discontinued programming language created by James Gosling in 1989, initially for Sun Microsystems' set-top box project. The language later evolved to become Java. History In 1985, Sun Microsystems was attempting to develop a new technology for programming next generation smart appliances, which Sun expected to be a major new opportunity. The team originally considered using C++, but rejected the idea for several reasons (see Java history). Initially, Gosling attempted to modify and extend C++ but soon abandoned that in favor of creating a new platform called Green and an entirely new language, which he called Oak, after the oak tree that stood just outside his office. By the summer of 1992, they were able to demonstrate portions of the new platform including the Green OS, the Oak language, the libraries, and the hardware. Their first attempt, demonstrated on September 3, 1992, focused on building a PDA device named Star7 which had a graphical interface and a smart agent called "Duke" to assist the user. Oak was renamed Java in 1994 after a trademark search revealed that Oak was used by Oak Technology. Java 1.0 was finally shipped in 1996. Differences with Java Oak was the basis for what Java 1.0 became later, but there were also some differences: Several concepts were planned in the Oak specification but were not implemented in the original language because of time constraints: Other concepts were different from, or improved later, for Java: And finally some concepts were later scraped out: See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Category:All_articles_that_may_have_off-topic_sections] | [TOKENS: 103] |
Category:All articles that may have off-topic sections This is a category to help keep count of the total number of articles with the {{off topic}} or {{relevance inline}} templates. They should all be in one of the dated categories. See also Category:Wikipedia articles that may have off-topic sections. Pages in category "All articles that may have off-topic sections" The following 200 pages are in this category, out of approximately 1,435 total. This list may not reflect recent changes. |
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[SOURCE: https://en.wikipedia.org/wiki/File:Elon_Musk_and_the_Neuralink_Future.jpg] | [TOKENS: 537] |
File:Elon Musk and the Neuralink Future.jpg Summary It felt like a scene from a sci-fi movie when we entered.. surrounded by brain robots, and the sounds of neural-jacked pigs rustling behind the curtains... C|Net: "Elon Musk shows Neuralink brain implant working in a pig. A wireless link from the Neuralink computing device showed the pig's brain activity as it snuffled around a pen on stage Friday night. The demonstration shows the technology to be significantly closer to delivering on Musk's radical ambitions than during a 2019 product debut, when Neuralink only showed photos of a rat with a Neuralink connected via a USB-C port. The FDA granted approval for "breakthrough device" testing. "It's like a Fitbit in your skull with tiny wires," Musk said of the device. It communicates with brain cells with 1,024 thin electrodes that penetrate the outer layer of the brain. Then there's a Bluetooth link to an outside computing device, though the company is looking at other radio technology it can use to dramatically increase the number of data links. Neuralink has a medical focus to start, like helping people deal with brain and spinal cord injuries or congenital defects. The technology could, for example, help paraplegics who've lost the ability to move or sense because of spinal cord injury, and the first human uses will aim to improve conditions like paraplegia or tetraplegia. "If you can sense what people want to do with their limbs, you can do a second implant where the spinal injury occurred and create a neural shunt," Musk said. "I'm confident in the long term it'll be possible to restore somebody's full body motion." "The future is going to be weird," Musk said, discussing sci-fi uses of Neuralink. "In the future you will be able to save and replay memories," he said. "You could basically store your memories as a backup and restore the memories. You could potentially download them into a new body or into a robot body." Musk also discussed seeing in infrared, ultraviolet or X-ray using digital camera data. "Over time we could give somebody super vision," Musk said." Licensing 30 August 2020 File history Click on a date/time to view the file as it appeared at that time. File usage The following 8 pages use this file: Global file usage The following other wikis use this file: Metadata This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified file. |
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[SOURCE: https://en.wikipedia.org/wiki/Novelty_song] | [TOKENS: 3595] |
Contents Novelty song A novelty song is a type of song built upon some form of novel concept, such as a gimmick, a piece of humor, or a sample of popular culture. Novelty songs partially overlap with comedy songs, which are more explicitly based on humor, and with musical parody, especially when the novel gimmick is another popular song. Novelty songs achieved great popularity during the 1920s and 1930s. They had a resurgence of interest in the 1950s and 1960s. The term arose in Tin Pan Alley to describe one of the major divisions of popular music; the other two divisions were ballads and dance music. Humorous songs, or those containing humorous elements, are not necessarily novelty songs. Novelty songs are often a parody or humor song, and may apply to a current event such as a holiday or a fad such as a dance or TV program. Many use unusual lyrics, subjects, sounds, or instrumentation, and may not even be musical. For example, the 1966 novelty song "They're Coming to Take Me Away, Ha-Haaa!", by Napoleon XIV, has little music and is set to a rhythm tapped out on a snare drum, a tambourine, and the bare sides of the musicians' legs. A book on achieving an attention-grabbing novelty single is The Manual (How to Have a Number One the Easy Way), written by The KLF. It is based on their achievement of a UK number-one single with "Doctorin' the Tardis", a 1988 dance remix mashup of the Doctor Who theme music released under the name of 'The Timelords'. It argued that (at the time) achieving a number one single could be achieved less by musical talent than through market research, sampling and gimmicks matched to an underlying danceable groove. Novelty songs are, by their nature, among the most ephemeral songs in popular music and seldom achieve enduring popularity, being described in 2025 as "popular culture’s most disposable art form(.)" History Novelty songs were a major staple of Tin Pan Alley from its start in the late 19th century. They continued to proliferate in the early years of the 20th century, some rising to be among the biggest hits of the era. Varieties included songs with an unusual gimmick, such as the stuttering in "K-K-K-Katy" or the playful boop-boop-a-doops of "I Wanna Be Loved By You", which made a star out of Helen Kane and inspired the creation of Betty Boop; silly lyrics like "Yes! We Have No Bananas"; playful songs with a bit of double entendre, such as "Don't Put a Tax on All the Beautiful Girls"; and invocations of foreign lands with emphasis on general feel of exoticism rather than geographic or anthropological accuracy, such as "Oh By Jingo!", "The Sheik of Araby", and "The Yodeling Chinaman". These songs were perfect for the medium of Vaudeville, and performers such as Eddie Cantor and Sophie Tucker became well known for such songs. Zez Confrey's 1920s instrumental compositions, which involved gimmicky approaches (such as "Kitten on the Keys") or maniacally rapid tempos ("Dizzy Fingers"), were popular enough to start a fad of novelty piano pieces that lasted through the decade. The fad was brought about by the increasing availability of audio recordings by way of the player piano and the phonograph; whereas much of Tin Pan Alley's repertoire was sold in the form of sheet music and thus had to be simple enough for an amateur pianist to play, novelty piano brought virtuoso-level performance to the home and to those who would not normally attend classical concerts. At the outbreak of World War II in 1939, "Hitler Has Only Got One Ball" (set to the tune of British Army bandmaster F. J. Ricketts's popular World War I–era "Colonel Bogey March") was sung by British troops. A 1940s novelty song was Spike Jones' 1942 "Der Fuehrer's Face", which included raspberries in its chorus. Tex Williams's "Smoke! Smoke! Smoke! (That Cigarette)" topped the Billboard best-sellers chart for six weeks and the country music chart for 16 weeks in 1947 and 1948. Hank Williams Sr.'s "Move It On Over", his first hit song, has some humor and novelty elements (about a man having to share the doghouse when his lover kicks him out of the house), but contemporaries (among them Jerry Rivers) disputed this and noted that many men had been faced with eviction under similar circumstances. The 1953 #1 single "(How Much Is) That Doggie in the Window?" became notable both for its extensive airplay and the backlash from listeners who found it increasingly annoying.[citation needed] Satirists such as Stan Freberg, Allan Sherman, and Tom Lehrer used novelty songs to poke fun at contemporary pop culture in the 1950s and early 1960s. In 1951, Frank Sinatra was paired in a CBS television special with TV personality Dagmar. Mitch Miller at Columbia Records became intrigued with the pairing and compelled songwriter Dick Manning to compose a song for the two of them. The result was "Mama Will Bark", a novelty song performed by Sinatra with interspersed spoken statements by Dagmar, saying things like "mama will bark", "mama will spank", and "papa will spank". The recording even includes the sound of a dog yowling. It is regarded by both music scholars and Sinatra enthusiasts to be perhaps the worst song he ever recorded. Sinatra would record a few others before he left Columbia and joined Capitol Records in 1952. Dickie Goodman faced a lawsuit for his 1956 novelty song "The Flying Saucer", which sampled snippets of contemporary hits without permission and arranged them to resemble interviews with an alien landing on Earth. Goodman released more hit singles in the same vein for the next two decades including his gold record RIAA certified hit "Mr. Jaws" in 1975, which charted #1 in Cash Box and Record World and was based on the movie Jaws. Among the more far out songs of this genre were the two released in 1956 by Nervous Norvus, "Transfusion" and "Ape Call". The Coasters had novelty songs such as "Charlie Brown" and "Yakety Yak". "Yakety Yak" became a #1 single on July 21, 1958, and is the only novelty song (#346) included in the Songs of the Century. "Lucky Ladybug" by Billy and Lillie was popular in December 1958. Lonnie Donegan's 1959 cover of the 1924 novelty song "Does Your Chewing Gum Lose Its Flavour (On the Bedpost Overnight?)" was a transatlantic hit, reaching #5 on the Billboard charts two years after its release; it was one of the earliest top-5 hits to come from the United Kingdom in the rock era, preceding the British Invasion. Three songs using a sped-up recording technique became #1 hits in the United States in 1958–59, Sheb Wooley's "The Purple People Eater" and two by David Seville: "Witch Doctor" and "The Chipmunk Song (Christmas Don't Be Late)". Seville sped up his voice on his two number-one tracks to invent the title characters to each song, the latter of which would introduce the breakout characters that came to dominate Seville's career, Alvin and the Chipmunks. The technique (which Dickie Goodman had also used on "The Flying Saucer") would inspire a number of other knockoffs, including The Nutty Squirrels and Russ Regan's one-off group Dancer, Prancer and Nervous. In 1960, 16-year-old Brian Hyland had a novelty hit with the song "Itsy Bitsy Teenie Weenie Yellow Polka Dot Bikini", by Paul Vance and Lee Pockriss, which topped the Billboard single chart. The Trashmen reached the top 5 with "Surfin' Bird", a surf rock medley of two novelty songs originally recorded by The Rivingtons. In 1964, the Grammy for Best Country and Western Album was awarded to Roger Miller. Miller was known to sing novelty songs. The British actor Bernard Cribbins had multiple novelty hits, starting with a satirical song from the revue And Another Thing entitled "Folk Song", written by Ted Dicks and Myles Rudge. The show brought Cribbins to the attention of Parlophone head George Martin, who signed Cribbins to the label to record a single. Subsequently, Rudge and Dicks were asked to provide new material for Cribbins; their compositions "The Hole in the Ground", about an annoyed workman who eventually buries a harasser, and "Right Said Fred", about three workmen who struggle to move an unspecified heavy and awkward object into or out of a building (later also the name of a pop novelty band who named themselves after the song), were top ten hits on the UK Singles Chart in 1962. In 1965, "A Windmill in Old Amsterdam", a song written by Ted Dicks and Myles Rudge, became a UK hit for Ronnie Hilton. The song spent a total of 13 weeks on the UK Singles Chart peaking at No. 23 in the chart of 17 February 1965. The song's composers were granted an Ivor Novello Award in 1966 for the Year's Outstanding Novelty Composition. Chuck Berry's "My Ding-a-Ling" reached #1 on the Billboard Hot 100 in 1972, and Ray Stevens, known for such novelty hits as "Ahab the Arab", "Gitarzan", and "Mississippi Squirrel Revival", had a #1 hit with "The Streak" in 1974. Comedy act Cheech & Chong recorded a number of musical bits that can be classified as novelty songs, including "Basketball Jones"(1973) and "Earache My Eye" (1974). Warren Zevon's lone chart hit was the novelty number "Werewolves of London". Other novelty songs in the '70s are Jimmy Castor Bunch's "Troglodyte" (and its sequel "The Bertha Butt Boogie"), Rick Dees' "Disco Duck" (1976) and The Fools' "Psycho Chicken" (1978). "Weird Al" Yankovic would emerge as one of the most prolific parody acts of all time in the 1980s, with a career that would span four decades; he would join Cliff Richard in being one of the few acts to have at least one top-40 hit in the U.S. in four consecutive decades (1950s through the 1980s for Richard, 1980s to 2010s for Yankovic). In the United Kingdom, the novelty country genre Scrumpy and Western became a brief fad in the 1970s. Sheb Wooley's parody "D.I.V.O.R.C.E." (a spoof of the Tammy Wynette song of the same name that Wooley had recorded under his "Ben Colder" persona) reached number one in 1975 with Billy Connolly's cover of it; a year later, "The Combine Harvester" (a spoof of Melanie's "Brand New Key") became a number-one hit for Brendan Grace in Ireland and The Wurzels in the UK. Randy Brooks wrote a Christmas novelty song and it was originally recorded by the duo Elmo Shropshire and his then-wife Patsy in 1979, called "Grandma Got Run Over by a Reindeer". It tells the tragic-comic story of a family grandmother (loosely based on Brooks's uncle Foster Brooks) who meets her end on Christmas Eve. After having drunk too much eggnog and forgetting to take her medicine, she staggers out of her family's house late Christmas Eve, is run over by Santa Claus' entourage, and found trampled at the scene the next morning. It has become a staple of Christmas music playlists on American radio since its original release. An underground novelty music scene began to emerge in the 1960s, beginning with the homosexually themed songs of Camp Records and the racist humor of Johnny Rebel, then in the 1970s and 1980s with X-rated albums by David Allan Coe and Clarence "Blowfly" Reid. Novelty songs have been popular in the UK as well. In 1991, "The Stonk" novelty song raised over £100,000 for the Comic Relief charity. In 1993, "Mr Blobby" became the second novelty song to reach the coveted Christmas number one slot in the UK, following Benny Hill's 1971 chart-topper "Ernie (The Fastest Milkman in the West)". Many popular children's TV characters would try to claim the Christmas number one spot after this. In 1997, the Teletubbies who reached number one the previous week failed to gain it with their single "Say Eh-oh!".[citation needed] They came second in the charts to The Spice Girls second of three consecutive Christmas number ones, with "Too Much".[citation needed] Later on at the turn of the millennium, Bob the Builder was successful in achieving a Christmas number one in 2000, with "Can We Fix It?". However, Bob the Builder did have another number one single a year later with a cover of Lou Bega's "Mambo No.5", and also had another less successful single in 2008 with "Big Fish Little Fish". Some novelty music draws its appeal from its unintentional novelty; so-called "outsider musicians" with little or no formal musical training often will produce comical results (see for instance, Florence Foster Jenkins, Mrs. Miller, the Portsmouth Sinfonia, The Shaggs, and William Hung). After the fictitious composer P.D.Q. Bach repeatedly won the "Best Comedy Album" Grammy from 1990 to 1993, the category was changed to "Best Spoken Comedy Album".[citation needed] When "Best Comedy Album" was reinstated in 2004, "Weird Al" Yankovic won for Poodle Hat.[citation needed] Novelty songs were popular on U.S. radio throughout the 1970s and 1980s, to the point where it was not uncommon for novelty songs to break into the top 40. Freeform and album-oriented rock stations made use of novelty songs; some of the best-known work from progressive rocker Frank Zappa, for instance, is his extensive body of mostly adult-oriented novelty music. Zappa's "Bobby Brown (Goes Down)" was a smash hit in Europe despite its sexually explicit storyline, and "Valley Girl" was a Top 40 hit in the US, while his "Don't Eat the Yellow Snow" and "Dancin' Fool" also reached the top 100 in his native United States. Beginning in 1970, Dr. Demento's nationally syndicated radio show gave novelty songs an outlet for much of the country; this lasted through the mid-2000s, when the show (mirroring trends in the genre) faded in popularity until its terrestrial cancellation in June 2010. Dr. Demento continued to host a self-produced pay-to-listen Internet radio broadcast of the series for the next 15 years until his retirement in October 2025. In the 21st century, novelty songs found a new audience online; the hit song "The Fox (What Does the Fox Say?)" by Norwegian comedy duo Ylvis was featured on the kids compilation album So Fresh Pop Party 13 in 2014. Likewise, rapper Big Shaq's 2017 hit "Man's Not Hot", which depicts a man who refuses to take off his jacket, received widespread attention and inspired countless memes as a result of its success, with the man behind the song being British comedian Michael Dapaah. The children's novelty song "Baby Shark" received widespread attention when Korean education brand Pinkfong's cover version from an online viral video reached the top 40 in the U.S. and several other countries. In the United Kingdom, the novelty hit has mainly become a feature of the "Christmas chart battle" (apart from a few viral hits found earlier in a year), with novelty act LadBaby reaching Number One five times in a row, with all five songs being parodies of other popular songs reworked to incorporate a running gag that revolves around sausage rolls. More often than not, the UK Christmas novelty records were recorded for charity, with LadBaby's Christmas chart rivals in 2020 also including The Dancing Binmen (Jack Johnson, Henry Wright and Adrian Breakwell) with their song "Boogie Round The Bins At Christmas Time", and "Merry Christmas, Baked Potato" from comedian Matt Lucas, with fellow chart contender "Raise The Woof!" being promoted as the first ever Christmas record for dogs. Top 10 chartings in the U.S. See also Notes Sources References Bibliography |
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[SOURCE: https://en.wikipedia.org/wiki/Datacard] | [TOKENS: 542] |
Contents Data card A datacard is an electronic card for data operations (storage, transfer, transformation, input, output). Datacard types Datacards can be sorted by their purposes: Expansion cards The expansion card in the computer is equipped with contacts on one of its edges, and it can be inserted into the motherboard slot socket. There are various types of expansion cards: Memory cards Many modern devices demand non-volatile memory requiring low power. Flash memory is used for these purposes. It is widespread in digital portable devices such as photo and video cameras, dictaphones, MP3 players, handheld computers, mobile phones, and also in smart phones and communicators. It is used for storage of the built-in software in various devices (like routers, mini-phonestations, printers, scanners, modems and controllers). In recent years USB flash-drives have become more popular and have almost replaced diskettes and CDs.[citation needed] Flash memory is well known from its use in USB flash-drives. Flash cards also are based on flash memory, such as Secure Digital (SD), Compact Flash and Memory Stick. These are much used in portable devices (cameras, mobile phones). Flash memory constitutes the biggest part of the portable data device market. Identification cards Contact smart cards (with chip) have a contact zone consisting of a few small contact petals. When the card is inserted into the reader, the chip connects with the card reader which can then read and write information. The standard ISO/IEC 7816 also regulates data exchange protocols and some aspects of work with other smart card data. Such cards are used for holder authorization for reception of certain services, such as bank account access for payments realization, use of prepaid mobile services, etc. The most widespread contact smart cards are SIM cards, payphone cards and some banking cards. This is often a microcircuit, such as a SIM card segregated from the ISO/IEC 7816 card and mounted in a tiny case with reader and USB connector. It makes smart-card application for computer authentification much more convenient. For example, an electronic key or eToken which is a personal authentification tool and a protected data storage device, supporting work with digital certificates and with an electronic digital signature. These are smart cards that communicate with the reader through radio transmission. The card must be close enough to the reader to perform necessary operations. Contactless cards are often used in areas where operations must be performed quickly, for example in public transport. There are many examples of contactless smart cards, such as travel tickets in underground and ground transport, the electronic ("biometric") passports, as well as some kinds of cards in access monitoring systems. References |
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[SOURCE: https://en.wikipedia.org/w/index.php?title=Social_network&action=edit§ion=4] | [TOKENS: 1430] |
Editing Social network (section) Copy and paste: – — ° ′ ″ ≈ ≠ ≤ ≥ ± − × ÷ ← → · § Cite your sources: <ref></ref> {{}} {{{}}} | [] [[]] [[Category:]] #REDIRECT [[]] <s></s> <sup></sup> <sub></sub> <code></code> <pre></pre> <blockquote></blockquote> <ref></ref> <ref name="" /> {{Reflist}} <references /> <includeonly></includeonly> <noinclude></noinclude> {{DEFAULTSORT:}} <nowiki></nowiki> <!-- --> <span class="plainlinks"></span> Symbols: ~ | ¡ ¿ † ‡ ↔ ↑ ↓ • ¶ # ∞ ‹› «» ¤ ₳ ฿ ₵ ¢ ₡ ₢ $ ₫ ₯ € ₠ ₣ ƒ ₴ ₭ ₤ ℳ ₥ ₦ ₧ ₰ £ ៛ ₨ ₪ ৳ ₮ ₩ ¥ ♠ ♣ ♥ ♦ 𝄫 ♭ ♮ ♯ 𝄪 © ¼ ½ ¾ Latin: A a Á á À à  â Ä ä Ǎ ǎ Ă ă Ā ā à ã Å å Ą ą Æ æ Ǣ ǣ B b C c Ć ć Ċ ċ Ĉ ĉ Č č Ç ç D d Ď ď Đ đ Ḍ ḍ Ð ð E e É é È è Ė ė Ê ê Ë ë Ě ě Ĕ ĕ Ē ē Ẽ ẽ Ę ę Ẹ ẹ Ɛ ɛ Ǝ ǝ Ə ə F f G g Ġ ġ Ĝ ĝ Ğ ğ Ģ ģ H h Ĥ ĥ Ħ ħ Ḥ ḥ I i İ ı Í í Ì ì Î î Ï ï Ǐ ǐ Ĭ ĭ Ī ī Ĩ ĩ Į į Ị ị J j Ĵ ĵ K k Ķ ķ L l Ĺ ĺ Ŀ ŀ Ľ ľ Ļ ļ Ł ł Ḷ ḷ Ḹ ḹ M m Ṃ ṃ N n Ń ń Ň ň Ñ ñ Ņ ņ Ṇ ṇ Ŋ ŋ O o Ó ó Ò ò Ô ô Ö ö Ǒ ǒ Ŏ ŏ Ō ō Õ õ Ǫ ǫ Ọ ọ Ő ő Ø ø Œ œ Ɔ ɔ P p Q q R r Ŕ ŕ Ř ř Ŗ ŗ Ṛ ṛ Ṝ ṝ S s Ś ś Ŝ ŝ Š š Ş ş Ș ș Ṣ ṣ ß T t Ť ť Ţ ţ Ț ț Ṭ ṭ Þ þ U u Ú ú Ù ù Û û Ü ü Ǔ ǔ Ŭ ŭ Ū ū Ũ ũ Ů ů Ų ų Ụ ụ Ű ű Ǘ ǘ Ǜ ǜ Ǚ ǚ Ǖ ǖ V v W w Ŵ ŵ X x Y y Ý ý Ŷ ŷ Ÿ ÿ Ỹ ỹ Ȳ ȳ Z z Ź ź Ż ż Ž ž ß Ð ð Þ þ Ŋ ŋ Ə ə Greek: Ά ά Έ έ Ή ή Ί ί Ό ό Ύ ύ Ώ ώ Α α Β β Γ γ Δ δ Ε ε Ζ ζ Η η Θ θ Ι ι Κ κ Λ λ Μ μ Ν ν Ξ ξ Ο ο Π π Ρ ρ Σ σ ς Τ τ Υ υ Φ φ Χ χ Ψ ψ Ω ω {{Polytonic|}} Cyrillic: А а Б б В в Г г Ґ ґ Ѓ ѓ Д д Ђ ђ Е е Ё ё Є є Ж ж З з Ѕ ѕ И и І і Ї ї Й й Ј ј К к Ќ ќ Л л Љ љ М м Н н Њ њ О о П п Р р С с Т т Ћ ћ У у Ў ў Ф ф Х х Ц ц Ч ч Џ џ Ш ш Щ щ Ъ ъ Ы ы Ь ь Э э Ю ю Я я ́ IPA: t̪ d̪ ʈ ɖ ɟ ɡ ɢ ʡ ʔ ɸ β θ ð ʃ ʒ ɕ ʑ ʂ ʐ ç ʝ ɣ χ ʁ ħ ʕ ʜ ʢ ɦ ɱ ɳ ɲ ŋ ɴ ʋ ɹ ɻ ɰ ʙ ⱱ ʀ ɾ ɽ ɫ ɬ ɮ ɺ ɭ ʎ ʟ ɥ ʍ ɧ ʼ ɓ ɗ ʄ ɠ ʛ ʘ ǀ ǃ ǂ ǁ ɨ ʉ ɯ ɪ ʏ ʊ ø ɘ ɵ ɤ ə ɚ ɛ œ ɜ ɝ ɞ ʌ ɔ æ ɐ ɶ ɑ ɒ ʰ ʱ ʷ ʲ ˠ ˤ ⁿ ˡ ˈ ˌ ː ˑ ̪ {{IPA|}} This page is a member of 6 hidden categories (help): |
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[SOURCE: https://en.wikipedia.org/wiki/History_of_the_Jews_in_Haiti] | [TOKENS: 1370] |
Contents History of the Jews in Haiti The history of the Jews in Haiti (French: Juifs en Haïti; Haitian Creole: Jwif Ayisyen yo) stretches from the beginning of the European settlement until the modern day. As of 2013, the Jewish population was around 25, predominantly in the capital of Port-au-Prince. History In 1492, the first Jew in Haiti was Luis de Torres, an interpreter for Christopher Columbus. After Haiti was taken over and colonized by the French in 1633, many Dutch Jews (of whom many were Marrano) emigrated from Brazil in 1634 and became employees of the French sugar plantations and further developed the trade. In 1683, the Jews were expelled from Haiti and all other French colonies, due to the Code Noir (Black Code), which both restricted the activities of free Negroes and forbade the exercise of any religion other than Roman Catholicism. However, despite the Code Noir, a limited number of Jews remained in French trading companies as leading officials, including foreign citizens (Dutch Jews, Danish Jews, and English Jews) or holders of special residence permits (lettres patentes). These Jews tended to specialize in agricultural plantations, with Portuguese Jews from Bordeaux and Bayonne settling mainly in the southern part of Haiti (Jacmel, Jérémie, Léogâne, Les Cayes, Petit-Goâve, and Port-au-Prince) and Curaçaoan Jews settling in the northern part (Cap-Haitien and Saint Louis). In the mid-1700s, many Jews returned to Haiti. Due to a lack of Jewish community centers, many youth did not grow up with a Jewish education and had to hide their Judaism, as only Catholics were permitted to attend public school. Jews generally preferred to settle on the coastline in port cities, as many were involved in commerce and trade, establishing communities in major industry centers. Recently, archaeologists uncovered an ancient synagogue of Crypto-Jews in the city of Jérémie, the only one found on the island; Jérémie was inhabited by many mixed-race families of Jewish descent. Several Jewish tombstones have also been found in port cities such as Cap-Haïtien and Jacmel. By the end of the 19th century, approximately thirty mostly Sephardi Jewish families had arrived from Lebanon, Syria, and Egypt; many Jews from the Middle East felt secure emigrating to Haiti, as a law in France had been passed during this period that gave French citizenship to minorities in the Americas. Modern times In 1915, during the United States occupation of Haiti, roughly 200 Jews lived in Haiti at the time. During the 20 years period of occupation, many Jews left Haiti for the United States and South America. In 1937, Haiti was responsible for saving about 70 Jewish families (an estimated total of up to 300 lives) during the Holocaust (according to the American Jewish Joint Distribution Committee), by issuing passports and visas to Jews escaping Nazi persecution. Some were Austrian Jews, Polish Jews, German Jews, and a trickle of Romanian Jew and Czech Jewish descent. Haiti played a small, yet critical role in saving Jewish lives during the darkest chapter in the Jewish story Unfortunately, though, it seems that more Jews were unable to acquire visas to Haiti due to the cost. Professor David Bankier, of the Institute of Contemporary Jewry at the Hebrew University of Jerusalem, said that after 1938, "the cost [of a visa] was outrageous: If you wanted to go to Haiti, you had to pay $5,000." Haiti at the time was still paying reparations on an exorbitant debt with interest fees to France after the Haitian Revolution that could have hindered their efforts to continue issuing these visas for free. There were others apart from this bunch who never came to Haiti at all, but from Germany they were given Haitian passports by the Haitian government that allowed them to flee Germany and into other countries. Grateful to the Haitian government, many of these European Jews stayed in Haiti until the late 1950s in which many Haitian Jews left, so that their children could marry other Jews and not assimilate, while finding better economic opportunities. The 1957 Jewish population of Haiti was about 200. The mid-20th century was a time of a continued departure of Jews from Haiti for the United States and Panama because of the economic conditions and civil violence in the country. Today, the Jewish community is led by Rabbi Douglas Lapin, a local businessman. The Jewish community is known as the "Consistoire d'Haiti" and has been recognized as the representative of the Jewish community by the Haitian Ministry of Religion (Ministere des Cultes) <Rep. d'Haiti; Ministere des Cultes DG/909 6 fevrier 2017>. Rabbi Lapin has likewise been recognized as the Rabbi in Haiti by the Haitian government<Tribunal de Premiere Instance de Port-au-Prince; Recipisse No. 3710084007-7; 4 Octobre 2017>. The community is very small and mostly consists of UN, NGO, and diplomatic personnel, although there are a small number of Haitian Jewish families. The community does Kosher chicken slaughtering (shechita) and has occasional gatherings for Jewish festivals such as Sukkot and Purim. There is also an Etrog, Myrtle (Hadass) and Willow (Aravah) plantation to supply local needs for Sukkot. The community is working on developing a synagogue and community center. There is a complete library of Jewish liturgical books (Sifrei Kodesh), as well as a handwritten Sefer Torah and Book of Esther. The 1960s was a time of wealth and high hopes of large future development for Haiti. At the time met many family Jewish names such as: Alvarez, Cardozo, Cohen, Dreyfus, Goldman, Hakim, Hillel, Khan, Monsanto, Pereira, Salzmann, Silveira, and Weiner, which most had forgotten their ethno-religious backgrounds. Today, less than a hundred Jews remain in Haiti of its 9.5 million inhabitants; however, the Weiners (coffee exporters) and the Salzmanns (refugees from Austria) are still today relevant in trade. Notable Haitian Jews See also References Further reading Bernard, Joseph Jr, "Haiti's Jewish History": https://www.amazon.com/gp/aw/d/B08TQ965QX/ref=dbs_a_w_dp_b08tq965qx External links |
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[SOURCE: https://en.wikipedia.org/wiki/Turkish_lira] | [TOKENS: 2483] |
Contents Turkish lira The lira (Turkish: Türk lirası; sign: ₺; ISO 4217 code: TRY; abbreviation: TL) is the official currency of Turkey. It is also legal tender in the de facto state of the Turkish Republic of Northern Cyprus. One lira is divided into one hundred kuruş. The First Turkish lira could be further subdivided, where one kuruş was equal to 40 para. The current lira is the Second Turkish lira, having succeeded the first Turkish lira in 2005 which in turn succeeded the Ottoman lira in 1923. Since 2018 the Turkish lira has been in crisis, having plummeted in value following Turkish president Erdoğan's economic and political policies. History The lira, along with the related currencies of Europe and the Middle East, has its roots in the ancient Roman unit of weight known as the libra which referred to the Troy pound of silver. The Roman libra adoption of the currency spread it throughout Europe and the Near East, where it continued to be used into medieval times. The Turkish lira, the French livre (until 1794), the Italian lira (until 2002), Lebanese pound and the pound unit of account in sterling (a translation of the Latin libra; the word "pound" as a unit of weight is still abbreviated as "lb.") are the modern descendants of the ancient currency. The lira was introduced as the main unit of account in 1844, with the former currency, kuruş, remaining as a 1⁄100 subdivision. The Ottoman lira remained in circulation until the end of 1927. The banknotes of the first and second issue depict Mustafa Kemal Atatürk on the obverse side. This change was done according to the 12 January 1926 issue of the official gazette. After Atatürk's death, his portrait was replaced with one of İsmet İnönü for the third and fourth issues. Atatürk returned for the fifth issue and all subsequent issues. After periods of the lira pegged to sterling and the franc, a peg of TL 2.8 = US$1 was adopted in 1946 and maintained until 1960, when the currency was devalued to TL 9 = US$1. From 1970, a series of hard, then soft pegs to the dollar operated as the value of the Turkish lira began to fall. The following are based on yearly averages: The Guinness Book of Records ranked the Turkish lira as the world's least valuable currency in 1995 and 1996, and again from 1999 to 2004. The lira's value had fallen so far that one original gold lira coin could be sold for TL 154,400,000 before the 2005 revaluation. On 28 January 2004, the Grand National Assembly of Turkey passed a law that allowed for redenomination by the removal of six zeros from the Turkish lira, and the creation of a new currency. It was introduced on 1 January 2005, replacing the previous Turkish lira (which remained valid in circulation until the end of 2005) at a rate of YTL 1 (ISO 4217 code "TRY") = TL 1,000,000 in old lira (ISO 4217 code "TRL"). With the revaluation of the Turkish lira, the Romanian leu (also revalued in July 2005) briefly became the world's least valued currency unit. At the same time, the Government introduced two new banknotes with the denominations of ₺50 and ₺100. In the transition period between January 2005 and December 2008, the second Turkish lira was officially called Yeni Türk lirası ("New Turkish lira"). The letter "Y" in the currency code was taken from the Turkish word yeni, meaning new. It was officially abbreviated "YTL" and subdivided into 100 new kuruş (yeni kuruş). Starting in January 2009, the "new" marking was removed from the second Turkish lira, its official name becoming just "Turkish lira" again, abbreviated "TL". All obverse sides of current banknotes have portraits of Mustafa Kemal Atatürk. The reverse sides of all coins (except for ₺1 commemorative coins) have portraits of Mustafa Kemal Atatürk. Since 2012, 9 different ₺1 circulating commemorative coins were introduced. In 2018, the lira's exchange rate deteriorated rapidly, reaching ₺4.5 per US dollar by mid-May and ₺4.9 a week later. Economists generally attributed the accelerating loss of value to Recep Tayyip Erdoğan preventing the Central Bank of the Republic of Turkey from making necessary interest rate adjustments. Erdoğan, who claimed interest rates beyond his control to be "the mother and father of all evil", stated that "the central bank can't take this independence and set aside the signals given by the president." Despite Erdoğan's apparent opposition, Turkey's Central Bank raised interest rates sharply. As of 2020, the Turkish lira lowered in value, with the currency going through a process of depreciation, consistently reaching all-time lows. The Turkish lira depreciated by over 400% compared to the US dollar and the euro since 2008, largely due to Erdoğan's expansionist foreign policy. Erdoğan has tried to fix the financial crisis with unorthodox banking methods. The Turkish lira partially recovered in early 2021 with the government's increase in interest rates. However, the currency began to crash due to inflation and depreciation starting on 21 March 2021, after the sacking of Central Bank chief Naci Ağbal. The Turkish lira reached a then-all-time-low of ₺8.8 to the dollar on 4 June. The Turkish lira became one of the quickest collapsing currencies of 2021. The Turkish lira reached a new low of ₺8.9 to the dollar in September 2021. In late 2021, the Turkish lira began collapsing rapidly, with the exchange rate falling 9% against the US dollar, reaching an all-time low of ₺12.5 to the dollar. The Turkish lira continued to collapse in December, with the inflation rate reaching unseen levels, collapsing to ₺14.5 to the US Dollar, losing nearly all of its original value. On 17 December, the lira fell by 8.5%, raising the exchange rate to ₺16.5 to the US dollar. Despite the currency collapse, Erdoğan lowered interest rates down to 14% from 15%, causing the lira to lose half of its value since the start of 2021. The Turkish Lira continued to decline throughout 2022. The central bank governor Şahap Kavcıoğlu lowered interest rates by 150 basis points, from 12% to 10.5%, down from the 2021 low of 15%. The official inflation rate of the Lira through 2022 reached 83%, but independent reviews of the Turkish lira put the inflation rate even higher. In 2023, Erdoğan began to follow orthodox banking methods. Under the guidance of Mehmet Şimşek and Hafize Gaye Erkan, the central bank began to rapidly increase interest rates. By the end of the year, the interest rate stood at 42.5%, and the annual inflation rate decreased to 53.86%, down from 83% in 2022. The central bank increased the interest rate to 50% in March 2024 under Fatih Karahan, the new governor, and has kept it as such as for eight consecutive months. This has resulted in the lira gaining value since May, when inflation peaked at 75.45%, but has decreased to 47.09% in November. The Turkish Lira has regained some valuation. Following the arrest of the mayor of Istanbul, Ekrem Imamoglu, in March 2025, Marketwatch reported that the Turkish lira reached a record low. The Turkish Lira began depreciating rapidly in early 2026 compared to the Euro and USD. Coins From 1 January 2009, the prefix "new" was removed from the second Turkish lira, its official name in Turkey becoming "Turkish lira" again; new coins without the word "yeni" were introduced in denominations of 1kr., 5kr., 10kr., 25kr., 50kr. and ₺1. Also, the center and ring alloys of the 50kr. and ₺1 coins were reversed. Since 2012, the Turkish State Mint has introduced ten commemorative coins in circulation. Banknotes A new series of banknotes, the "E-9 Emission Group" entered circulation on 1 January 2009, with the E-8 group ceasing to be valid after 31 December 2009 (although still redeemable at branches of the Central Bank until 31 December 2019). The E-9 banknotes refer to the currency as "Turkish lira" rather than "new Turkish lira" and include a new ₺200 denomination. The new banknotes have different sizes to prevent forgery. The main specificity of this new series is that each denomination depicts a famous Turkish personality, rather than geographical sites and architectural features of Turkey. The dominant color of the 5-Turkish-lira banknote has been determined as "purple" on the second series of the current banknotes. Currency sign The lira was originally symbolised as TL, inverting the characters of the Ottoman lira's sign, LT, which stood for "Livre Turque" in French. Historically English language sources used "£T" or "T£" for the currency, but it is unknown whether this notation was ever used within Turkey. The current currency sign of Turkish lira was created by the Central Bank of the Republic of Turkey in 2012. The new sign was selected after a country-wide contest. The new symbol is composed of the letter L shaped like a half anchor, and embedded double-striped letter T angled at 20 degrees. The design, created by Tülay Lale, was endorsed after a country-wide competition. It was chosen as the winner from a shortlist of seven submissions to the board of the Central Bank, selected from a total of 8,362 entries. The symbol resembles the first letter of the Turkish monetary unit, L, in the form of a half anchor with double stroke. Prime Minister Recep Tayyip Erdoğan announced the new symbol on 1 March 2012. At its unveiling, Erdoğan explained the design as "the anchor shape hopes to convey that the currency is a 'safe harbour' while the upward-facing lines represent its rising prestige". Faik Öztrak, vice chairman of the main opposition party CHP, alleged that the new sign resembles the initials TE of then-prime minister Tayyip Erdoğan in a reference to the tughra of Ottoman sultans. The new Turkish lira sign was also criticized for allegedly showing a similarity with an upside-down Armenian dram sign. In May 2012, the Unicode Technical Committee accepted the encoding of a new character U+20BA ₺ TURKISH LIRA SIGN for the currency sign, which was included in Unicode 6.2 released in September 2012. On Microsoft Windows operating systems, when using Turkish-Q or Turkish-F keyboard layouts, it can be typed with the combination AltGr+T. Circulation Current exchange rates See also Notes References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Meta_Platforms#cite_note-3] | [TOKENS: 8626] |
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/Parody_music] | [TOKENS: 2150] |
Contents Parody music Parody music, or musical parody, involves changing or copying existing (usually well known) musical ideas, and/or lyrics, or copying the particular style of a composer or performer, or even a general style of music. In music, parody has been used for many different purposes and in various musical contexts: as a serious compositional technique, as an unsophisticated re-use of well-known melody to present new words, and as an intentionally humorous, even mocking, reworking of existing musical material, sometimes for satirical effect. Examples of musical parody with completely serious intent include parody masses in the 16th century, and, in the 20th century, the use of folk tunes in popular song, and neo-classical works written for the concert hall, drawing on earlier styles. "Parody" in this serious sense continues to be a term in musicological use, existing alongside the more common use of the term to refer to parody for humorous effect. Etymology The word "parody" derives from the post-classical Latin parodia, which came from the Greek παρῳδία (lit. 'burlesque poem/song'). History The earliest musical application of this Greek term was only in 1587, on the title-page of a parody mass by the German composer Jakob Paix, as the equivalent of the previously usual Latin expressions missa ad imitationem or missa super …, which were used to acknowledge the source of borrowed musical material. Such preferences for Greek terms were a product of Renaissance humanism, which was strong in Germany by that time though the word's use was infrequent and casual. It was only in modern times that the term "parody technique" came into general use as a historical musicological term, especially after the publication of Peter Wagner’s Geschichte der Messe in 1913. Although the practice of borrowing preexisting polyphonic textures dates back to the 14th century, these earlier manifestations are closer to the technique of contrafactum than to the parody of 16th-century music. In the latter part of the 15th century, composers began to include the other voices of a polyphonic model in basically cantus firmus structures, such as Jacob Obrecht's Missa Fortuna desperata and Missa Rosa playsante. In Grove's Dictionary of Music and Musicians, Michael Tilmouth and Richard Sherr write of the genre: The essential feature of parody technique is that not merely a single part is appropriated to form a cantus firmus in the derived work, but the whole substance of the source – its themes, rhythms, chords and chord progressions – is absorbed into the new piece and subjected to free variation in such a way that a fusion of old and new elements is achieved. Many of the most famous composers of the 16th century, including Victoria, Lassus and Palestrina, used a wide range of earlier music in their masses, drawing on existing secular as well as religious pieces.[a] After the beginning of the Baroque period, there continued to be parodies with serious intent. Examples include J. S. Bach's reuse of three cantatas in his Christmas Oratorio, and of many movements in the Mass in B Minor, which, to a large extent, he compiled from his own prior works. Bach frequently and systematically did this, parodying his own occasional works to preserve them for more frequent use. As musical fashions changed, however, there was little cause to re-use old modal tunes and compositional styles. After the middle of the 17th century, composers sought to create "a unique musical treatment appropriate to the text and the circumstances of performance". Thereafter the serious parody became rare until the 20th century. The parodic elements of Bach's "Cantate burlesque", Peasant Cantata are humorous in intent, making fun of the florid da capo arias then in fashion. Thereafter "parody" in music has generally been associated with humorous or satiric treatment of borrowed or imitative material. Later in the 18th century, Mozart parodied the lame melodies and routine forms of lesser composers of his day in his Musical Joke. A century later, Saint-Saëns composed The Carnival of the Animals as a musical joke for his friends; several of the movements contain musical parody, radically changing the tempo and instrumentation of well-known melodies.[b] Bartók's Concerto for Orchestra (1943) features the appearance (followed by a trombone raspberry) of a theme from Shostakovich's Leningrad Symphony.[c] In theatrical music, the 18th century ballad opera, which included satirical songs set to popular melodies of the time, involved some of the broadest musical parodies. In Così fan tutte Mozart parodied the elaborate solemnities of opera seria arias. His own The Magic Flute was the subject of Viennese parodies in the decades after his death. Parodies of Wagner range from Souvenirs de Bayreuth by Fauré and Messager (sending up music from the Ring cycle by turning the themes into dance rhythm) to Anna Russell's Introduction to the Ring, which parodies the words and music of the cycle by presenting their supposed absurdities in a mock-academic lecture format.[d] Offenbach, a frequent parodist (of among others Gluck, Donizetti and Meyerbeer), was himself parodied by later composers from Saint-Saëns to Sondheim. In the Savoy operas, Sullivan parodied the styles of Handel, Bellini, Mozart, Verdi and others. His own music has been parodied ever since. The parodic use of well-known tunes with new lyrics is a common feature of Victorian burlesque and pantomime, British theatrical styles popularised in the 19th century. Serious parody was revived, in modified form, in the 20th century, with such works as Prokoviev's Classical Symphony and Stravinsky's neo-classical works including The Fairy's Kiss and Pulcinella. However, Tilmouth and Sherr comment that although these works exhibit "the kind of interaction of composer and model that was characteristic of 16th-century parody", they nevertheless employ "a stylistic dichotomy far removed from it". The same authors comment that the use of old music in the scores of Peter Maxwell Davies similarly "engenders a conflict foreign to the total synthesis that was the aim of 16th-century parody". Parody in popular music Popular music has used parody in a variety of ways. These include parodies of earlier music, for comic or (sometimes) serious effect; parodies of musical and performing styles; and parodies of particular performers. Before the 20th century, popular song frequently borrowed hymn tunes and other church music and substituted secular words. "John Brown's Body", the marching song of the American Civil War, was based on the tune of an earlier camp-meeting and revival hymn, and was later fitted with the words "Mine eyes have seen the glory of the coming of the Lord", by Julia Ward Howe. This practice continued into the First World War, with many of the soldiers' songs being based on hymn tunes (for instance "When this lousy war is over", to the tune of "What a Friend We Have in Jesus" and "We are Fred Karno's Army", to the tune of "The Church's One Foundation"). Folk song has often been written to existing tunes, or slight modifications of them. This is another very old (and usually non-humorous) kind of musical parody that still continues. For instance, Bob Dylan took the tune of the old slave song "No more auction block for me" as the basis for "Blowin' in the Wind". In the 1940s Spike Jones and his City Slickers parodied popular music in their own way, not by changing lyrics, but adding wild sound effects and comedic stylings to formerly staid old songs. The 1957 Broadway musical Jamaica parodied the then very fashionable commercial variety of Calypso music. A musical using heavy parody was the 1959 show Little Mary Sunshine, which poked fun at old-fashioned operetta. Parodists of music from the concert hall or lyric theatre have included Allan Sherman, known for adding comic words to existing works by such composers as Ponchielli and Sullivan; and Tom Lehrer, who has parodied Sullivan, folk music, ragtime and Viennese operetta. The pianist Victor Borge is also noted for parodies of classical and operatic works. The musical satirist Peter Schickele created P. D. Q. Bach, a supposedly newly discovered member of the Bach family, whose creative output parodies musicological scholarship, the conventions of Baroque and classical music, as well as introducing elements of slapstick comedy. Stan Freberg created parodies of popular songs in the 1950s and 1960s, mocking the musical conventions of the day, such as his cover of Elvis Presley's "Heartbreak Hotel" where he complains of "too much echo". The bandleader and pianist Paul Weston and his wife, singer Jo Stafford, created the musical duo, "Jonathan and Darlene Edwards", as a parody of bad cabaret acts. The British group The Barron Knights became famous for their parodies of pop performers in the 1970s, whilst The Bar-Steward Sons of Val Doonican currently perform comedy parodies of popular songs from a wide of genres primarily on folk instruments. Parodists with differing techniques have included "Weird Al" Yankovic and Bob Rivers, who have generally put new lyrics to largely unchanged music, and Richard Cheese and Lounge Against the Machine or The Lounge Kittens keeps the lyrics intact but alters the musical style, performing rap, metal, and rock songs in a lounge style. Country Yossi, a pioneering composer and singer in the Jewish music genre, reworks the lyrics of country music and other mainstream hits to convey Orthodox Jewish themes. Another example of musical parody is Mac Sabbath, a Black Sabbath tribute band who utilize McDonald's-themed props and costumes with altered lyrics satirizing the fast food industry. Parody in the 21st century has included the 2005 musical Altar Boyz, which parodies both Christian rock and the "boy band" style of pop. See also Notes and references Notes References Sources Further reading |
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[SOURCE: https://en.wikipedia.org/wiki/Cellular_router] | [TOKENS: 1255] |
Contents Mobile broadband modem A mobile broadband modem, also known as wireless modem or cellular modem, is a type of modem that allows a personal computer or a router to receive wireless Internet access via a mobile broadband connection instead of using telephone or cable television lines. A mobile Internet user can connect using a wireless modem to a wireless Internet service provider (ISP) to get Internet access. History While some analogue mobile phones provided a standard RJ11 telephone socket into which a normal landline modem could be plugged, this only provided slow dial-up connections, usually 2.4 kilobits per second (kbit/s) or less. In 1984, Spectrum Information Technologies released the first mobile broadband modem, the Bridge, which connected to the analogue Advanced Mobile Phone System (AMPS) of the United States. It connected in between the telephone socket and a computer's serial port, providing its own proprietary error correction routines in order to reduce the incidence of dropped connections during handover, a major problem when plugging into cellular transceivers directly. Because of its proprietary protocols, it necessitated a corresponding device at the site of the called party or central office, which was branded the Span. The first personal computer with a built-in mobile broadband modem was the ITC 286 CAT, a laptop by Intelligence Technology Corporation. Released in 1988, it featured a Hayes-compatible AMPS modem capable of transmitting data at 1.2 kbit/s. The next generation of phones, known as 2G (for 'second generation'), were digital, and offered faster dial-up speeds of 9.6 kbit/s or 14.4 kbit/s without the need for a separate modem. A further evolution called HSCSD used multiple GSM channels (two or three in each direction) to support up to 43.2 kbit/s. All of these technologies still required their users to have a dial-up ISP to connect to and provide the Internet access - it was not provided by the mobile phone network itself. The release of 2.5G phones with support for packet data changed this. The 2.5G networks break both digital voice and data into small chunks, and mix both onto the network simultaneously in a process called packet switching. This allows the phone to have a voice connection and a data connection at the same time, rather than a single channel that has to be used for one or the other. The network can link the data connection into a company network, but for most users the connection is to the Internet. This allows web browsing on the phone, but a PC can also tap into this service if it connects to the phone. The PC needs to send a special telephone number to the phone to get access to the packet data connection. From the PC's viewpoint, the connection still looks like a normal PPP dial-up link, but it is all terminating on the phone, which then handles the exchange of data with the network. Speeds on 2.5G networks are usually in the 30–50 kbit/s range. 3G networks have taken this approach to a higher level, using different underlying technology but the same principles. They routinely provide speeds over 300 kbit/s. Due to the now-increased internet speed, internet connection sharing via WLAN has become a workable reality. Devices which allow internet connection sharing or other types of routing on cellular networks are also called cellular routers. A further evolution is the 3.5G technology HSDPA, which provides speeds of multiple megabits per second. Several of the mobile network operators that provide 3G or faster wireless internet access offer plans and wireless modems that enable computers to connect to and access the internet. These wireless modems are typically in the form of a small USB based device or a small, portable mobile hotspot that acts as a WiFi access point (hotspot) to enable multiple devices to connect to the internet. WiMAX based services that provide high speed wireless internet access are available in some countries and also rely on wireless modems that connect to the provider's wireless network. Wireless USB modems are nicknamed "dongles". Early 3G mobile broadband modems used the PCMCIA or ExpressCard ports, commonly found on legacy laptops. The expression "connect card" (instead of connection card) had been registered and used the first time by Vodafone as brand for its products but now it is a generic trademark used in colloquial or commercial speech for similar products too, made by different manufacturers. Major producers are Huawei, Option N.V. and Novatel Wireless. More recently, the expression "connect card" is also used to identify internet USB keys. Vodafone brands this type of device as a Vodem. Often a mobile network operator will supply a 'locked' modem or other wireless device that can only be used on their network. It is possible to use online unlocking services that will remove the 'lock' so the device accepts SIM cards from any network. Variants Standalone mobile broadband modems are designed to be connected directly to one computer. In the past the PCMCIA and ExpressCard standards were used to connect to the computer. As USB connectivity became almost universal, these various standards were largely superseded by USB modems in the early 21st century. Some models have GPS support, providing geographical location information. Many mobile broadband modems sold nowadays also have built-in routing capabilities. They provide traditional networking interfaces such as Ethernet, USB and Wi-Fi. Numerous smartphones support the Hayes command set and therefore can be used as a mobile broadband modem. Some mobile network operators charge a fee for this facility, if able to detect the tethering. Other networks have an allowance for full speed mobile broadband access, which—if exceeded—can result in overage charges or slower speeds. An Internet-accessing smartphone may have the same capabilities as a standalone modem, and, when connected via a USB cable to a computer, can serve as a modem for the computer. Smartphones with built-in Wi-Fi also typically provide routing and wireless access point facilities. This method of connecting is commonly referred to as "tethering." Service providers There are competing common carriers broadcasting signal in most countries. Technologies See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Array_index] | [TOKENS: 3574] |
Contents Array (data structure) In computer science, an array is a data structure consisting of a collection of elements (values or variables), of same memory size, each identified by at least one array index or key, a collection of which may be a tuple, known as an index tuple. In general, an array is a mutable and linear collection of elements with the same data type. An array is stored such that the position (memory address) of each element can be computed from its index tuple by a mathematical formula. The simplest type of data structure is a linear array, also called a one-dimensional array. For example, an array of ten 32-bit (4-byte) integer variables, with indices 0 through 9, may be stored as ten words at memory addresses 2000, 2004, 2008, ..., 2036, (in hexadecimal: 0x7D0, 0x7D4, 0x7D8, ..., 0x7F4) so that the element with index i has the address 2000 + (i × 4). The memory address of the first element of an array is called first address, foundation address, or base address. Because the mathematical concept of a matrix can be represented as a two-dimensional grid, two-dimensional arrays are also sometimes called "matrices". In some cases the term "vector" is used in computing to refer to an array, although tuples rather than vectors are the more mathematically correct equivalent. Tables are often implemented in the form of arrays, especially lookup tables; the word "table" is sometimes used as a synonym of array. Arrays are among the oldest and most important data structures, and are used by almost every program. They are also used to implement many other data structures, such as lists and strings. They effectively exploit the addressing logic of computers. In most modern computers and many external storage devices, the memory is a one-dimensional array of words, whose indices are their addresses. Processors, especially vector processors, are often optimized for array operations. Arrays are useful mostly because the element indices can be computed at run time. Among other things, this feature allows a single iterative statement to process arbitrarily many elements of an array. For that reason, the elements of an array data structure are required to have the same size and should use the same data representation. The set of valid index tuples and the addresses of the elements (and hence the element addressing formula) are usually, but not always, fixed while the array is in use. The term "array" may also refer to an array data type, a kind of data type provided by most high-level programming languages that consists of a collection of values or variables that can be selected by one or more indices computed at run-time. Array types are often implemented by array structures; however, in some languages they may be implemented by hash tables, linked lists, search trees, or other data structures. The term is also used, especially in the description of algorithms, to mean associative array or "abstract array", a theoretical computer science model (an abstract data type or ADT) intended to capture the essential properties of arrays. History The first digital computers used machine-language programming to set up and access array structures for data tables, vector and matrix computations, and for many other purposes. John von Neumann wrote the first array-sorting program (merge sort) in 1945, during the building of the first stored-program computer. Array indexing was originally done by self-modifying code, and later using index registers and indirect addressing. Some mainframes designed in the 1960s, such as the Burroughs B5000 and its successors, used memory segmentation to perform index-bounds checking in hardware. Assembly languages generally have no special support for arrays, other than what the machine itself provides. The earliest high-level programming languages, including FORTRAN (1957), Lisp (1958), COBOL (1960), and ALGOL 60 (1960), had support for multi-dimensional arrays, and so has C (1972). In C++ (1983), class templates exist for multi-dimensional arrays whose dimension is fixed at runtime as well as for runtime-flexible arrays. Applications Arrays are used to implement mathematical vectors and matrices, as well as other kinds of rectangular tables. Many databases, small and large, consist of (or include) one-dimensional arrays whose elements are records. Arrays are used to implement other data structures, such as lists, heaps, hash tables, deques, queues, stacks, strings, and VLists. Array-based implementations of other data structures are frequently simple and space-efficient (implicit data structures), requiring little space overhead, but may have poor space complexity, particularly when modified, compared to tree-based data structures (compare a sorted array to a search tree). One or more large arrays are sometimes used to emulate in-program dynamic memory allocation, particularly memory pool allocation. Historically, this has sometimes been the only way to allocate "dynamic memory" portably. Arrays can be used to determine partial or complete control flow in programs, as a compact alternative to (otherwise repetitive) multiple IF statements. In this context, they are known as control tables and are used in conjunction with a purpose-built interpreter whose control flow is altered according to values contained in the array. The array may contain subroutine pointers (or relative subroutine numbers that can be acted upon by SWITCH statements) that direct the path of the execution of the program. Element identifier and addressing formulas When data objects are stored in an array, individual objects are selected by an index that is usually a non-negative scalar integer. Indexes are also called subscripts. An index maps the array value to a stored object. There are three ways in which the elements of an array can be indexed: Using zero based indexing is the design choice of many influential programming languages, including C, Java and Lisp. This leads to simpler implementation where the subscript refers to an offset from the starting position of an array, so the first element has an offset of zero. Arrays can have multiple dimensions, thus it is not uncommon to access an array using multiple indices. For example, a two-dimensional array A with three rows and four columns might provide access to the element at the 2nd row and 4th column by the expression A in the case of a zero-based indexing system. Thus two indices are used for a two-dimensional array, three for a three-dimensional array, and n for an n-dimensional array. The number of indices needed to specify an element is called the dimension, dimensionality, or rank of the array. In standard arrays, each index is restricted to a certain range of consecutive integers (or consecutive values of some enumerated type), and the address of an element is computed by a "linear" formula on the indices. A one-dimensional array (or single dimension array) is a type of linear array. Accessing its elements involves a single subscript which can either represent a row or column index. As an example consider the C declaration int a; which declares a one-dimensional array named a of ten integers. Here, the array can store ten elements of type int . This array has indices starting from zero through nine. For example, the expressions a and a are the first and last elements respectively. For a vector with linear addressing, the element with index i is located at the address B + c · i, where B is a fixed base address and c a fixed constant, sometimes called the address increment or stride. If the valid element indices begin at 0, the constant B is simply the address of the first element of the array. For this reason, the C programming language specifies that array indices always begin at 0; and many programmers will call that element "zeroth" rather than "first". However, one can choose the index of the first element by an appropriate choice of the base address B. For example, if the array has five elements, indexed 1 through 5, and the base address B is replaced by B + 30c, then the indices of those same elements will be 31 to 35. If the numbering does not start at 0, the constant B may not be the address of any element. For a multidimensional array, the element with indices i,j would have address B + c · i + d · j, where the coefficients c and d are the row and column address increments, respectively. More generally, in a k-dimensional array, the address of an element with indices i1, i2, ..., ik is For example: int a; This means that array a has 2 rows and 3 columns, and the array is of integer type. Here we can store 6 elements they will be stored linearly but starting from first row linear then continuing with second row. The above array will be stored as a11, a12, a13, a21, a22, a23. This formula requires only k multiplications and k additions, for any array that can fit in memory. Moreover, if any coefficient is a fixed power of 2, the multiplication can be replaced by bit shifting. The coefficients ck must be chosen so that every valid index tuple maps to the address of a distinct element. If the minimum legal value for every index is 0, then B is the address of the element whose indices are all zero. As in the one-dimensional case, the element indices may be changed by changing the base address B. Thus, if a two-dimensional array has rows and columns indexed from 1 to 10 and 1 to 20, respectively, then replacing B by B + c1 − 3c2 will cause them to be renumbered from 0 through 9 and 4 through 23, respectively. Taking advantage of this feature, some languages (like FORTRAN 77) specify that array indices begin at 1, as in mathematical tradition while other languages (like Fortran 90, Pascal and Algol) let the user choose the minimum value for each index. The addressing formula is completely defined by the dimension d, the base address B, and the increments c1, c2, ..., ck. It is often useful to pack these parameters into a record called the array's descriptor, stride vector, or dope vector. The size of each element, and the minimum and maximum values allowed for each index may also be included in the dope vector. The dope vector is a complete handle for the array, and is a convenient way to pass arrays as arguments to procedures. Many useful array slicing operations (such as selecting a sub-array, swapping indices, or reversing the direction of the indices) can be performed very efficiently by manipulating the dope vector. Often the coefficients are chosen so that the elements occupy a contiguous area of memory. However, that is not necessary. Even if arrays are always created with contiguous elements, some array slicing operations may create non-contiguous sub-arrays from them. There are two systematic compact layouts for a two-dimensional array. For example, consider the matrix In the row-major order layout (adopted by C for statically declared arrays), the elements in each row are stored in consecutive positions and all of the elements of a row have a lower address than any of the elements of a consecutive row: In column-major order (traditionally used by Fortran), the elements in each column are consecutive in memory and all of the elements of a column have a lower address than any of the elements of a consecutive column: For arrays with three or more indices, "row major order" puts in consecutive positions any two elements whose index tuples differ only by one in the last index. "Column major order" is analogous with respect to the first index. In systems which use processor cache or virtual memory, scanning an array is much faster if successive elements are stored in consecutive positions in memory, rather than sparsely scattered. This is known as spatial locality, which is a type of locality of reference. Many algorithms that use multidimensional arrays will scan them in a predictable order. A programmer (or a sophisticated compiler) may use this information to choose between row- or column-major layout for each array. For example, when computing the product A·B of two matrices, it would be best to have A stored in row-major order, and B in column-major order. Static arrays have a size that is fixed when they are created and consequently do not allow elements to be inserted or removed. However, by allocating a new array and copying the contents of the old array to it, it is possible to effectively implement a dynamic version of an array; see dynamic array. If this operation is done infrequently, insertions at the end of the array require only amortized constant time. Some array data structures do not reallocate storage, but do store a count of the number of elements of the array in use, called the count or size. This effectively makes the array a dynamic array with a fixed maximum size or capacity; Pascal strings are examples of this. More complicated (non-linear) formulas are occasionally used. For a compact two-dimensional triangular array, for instance, the addressing formula is a polynomial of degree 2. Efficiency Both store and select take (deterministic worst case) constant time. Arrays take linear (O(n)) space in the number of elements n that they hold. In an array with element size k and on a machine with a cache line size of B bytes, iterating through an array of n elements requires the minimum of ceiling(nk/B) cache misses, because its elements occupy contiguous memory locations. This is roughly a factor of B/k better than the number of cache misses needed to access n elements at random memory locations. As a consequence, sequential iteration over an array is noticeably faster in practice than iteration over many other data structures, a property called locality of reference (this does not mean however, that using a perfect hash or trivial hash within the same (local) array, will not be even faster - and achievable in constant time). Libraries provide low-level optimized facilities for copying ranges of memory (such as memcpy) which can be used to move contiguous blocks of array elements significantly faster than can be achieved through individual element access. The speedup of such optimized routines varies by array element size, architecture, and implementation. Memory-wise, arrays are compact data structures with no per-element overhead. There may be a per-array overhead (e.g., to store index bounds) but this is language-dependent. It can also happen that elements stored in an array require less memory than the same elements stored in individual variables, because several array elements can be stored in a single word; such arrays are often called packed arrays. An extreme (but commonly used) case is the bit array, where every bit represents a single element. A single octet can thus hold up to 256 different combinations of up to 8 different conditions, in the most compact form. Array accesses with statically predictable access patterns are a major source of data parallelism. Dynamic arrays or growable arrays are similar to arrays but add the ability to insert and delete elements; adding and deleting at the end is particularly efficient. However, they reserve linear (Θ(n)) additional storage, whereas arrays do not reserve additional storage. Associative arrays provide a mechanism for array-like functionality without huge storage overheads when the index values are sparse. For example, an array that contains values only at indexes 1 and 2 billion may benefit from using such a structure. Specialized associative arrays with integer keys include Patricia tries, Judy arrays, and van Emde Boas trees. Balanced trees require O(log n) time for indexed access, but also permit inserting or deleting elements in O(log n) time, whereas growable arrays require linear (Θ(n)) time to insert or delete elements at an arbitrary position. Linked lists allow constant time removal and insertion in the middle but take linear time for indexed access. Their memory use is typically worse than arrays, but is still linear. An Iliffe vector is an alternative to a multidimensional array structure. It uses a one-dimensional array of references to arrays of one dimension less. For two dimensions, in particular, this alternative structure would be a vector of pointers to vectors, one for each row(pointer on c or c++). Thus an element in row i and column j of an array A would be accessed by double indexing (A[i][j] in typical notation). This alternative structure allows jagged arrays, where each row may have a different size—or, in general, where the valid range of each index depends on the values of all preceding indices. It also saves one multiplication (by the column address increment) replacing it by a bit shift (to index the vector of row pointers) and one extra memory access (fetching the row address), which may be worthwhile in some architectures. Dimension The dimension of an array is the number of indices needed to select an element. Thus, if the array is seen as a function on a set of possible index combinations, it is the dimension of the space of which its domain is a discrete subset. Thus a one-dimensional array is a list of data, a two-dimensional array is a rectangle of data, a three-dimensional array a block of data, etc. This should not be confused with the dimension of the set of all matrices with a given domain, that is, the number of elements in the array. For example, an array with 5 rows and 4 columns is two-dimensional, but such matrices form a 20-dimensional space. Similarly, a three-dimensional vector can be represented by a one-dimensional array of size three. See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Wireless] | [TOKENS: 2441] |
Contents Wireless Wireless communication (or just wireless, when the context allows) is the transfer of information (telecommunication) between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The most common wireless technologies use radio waves. With radio waves, intended distances can be short, such as a few meters for Bluetooth, or as far as millions of kilometers for deep-space radio communications. It encompasses various types of fixed, mobile, and portable applications, including two-way radios, cellular telephones, and wireless networking. Other examples of applications of radio wireless technology include GPS units, garage door openers, wireless computer mice, keyboards and headsets, headphones, radio receivers, satellite television, broadcast television and cordless telephones. Somewhat less common methods of achieving wireless communications involve other electromagnetic phenomena, such as light and magnetic or electric fields, or the use of sound. The term wireless has been used twice in communications history, with slightly different meanings. It was initially used from about 1890 for the first radio transmitting and receiving technology, as in wireless telegraphy, until the new word radio replaced it around 1920. Radio sets in the UK and the English-speaking world that were not portable continued to be referred to as wireless sets into the 1960s. The term wireless was revived in the 1980s and 1990s mainly to distinguish digital devices that communicate without wires, such as the examples listed in the previous paragraph, from those that require wires or cables. This became its primary usage in the 2000s, due to the advent of technologies such as mobile broadband, Wi-Fi, and Bluetooth. Wireless operations permit services, such as mobile and interplanetary communications, that are impossible or impractical to implement with the use of wires. The term is commonly used in the telecommunications industry to refer to telecommunications systems (e.g. radio transmitters and receivers, remote controls, etc.) that use some form of energy (e.g. radio waves and acoustic energy) to transfer information without the use of wires. Information is transferred in this manner over both short and long distances . History The first wireless telephone conversation occurred in 1880 when Alexander Graham Bell and Charles Sumner Tainter invented the photophone, a telephone that sent audio over a beam of light. The photophone required sunlight to operate, and a clear line of sight between the transmitter and receiver, which greatly decreased the viability of the photophone in any practical use. It would be several decades before the photophone's principles found their first practical applications in military communications and later in fiber-optic communications. A number of wireless electrical signaling schemes including sending electric currents through water and the ground using electrostatic and electromagnetic induction were investigated for telegraphy in the late 19th century before practical radio systems became available. These included a patented induction system by Thomas Edison allowing a telegraph on a running train to connect with telegraph wires running parallel to the tracks, a William Preece induction telegraph system for sending messages across bodies of water, and several operational and proposed telegraphy and voice earth conduction systems. The Edison system was used by stranded trains during the Great Blizzard of 1888 and earth conductive systems found limited use between trenches during World War I but these systems were never successful economically. In 1894, Guglielmo Marconi began developing a wireless telegraph system using radio waves, which had been known about since proof of their existence in 1888 by Heinrich Hertz, but discounted as a communication format since they seemed, at the time, to be a short-range phenomenon. Marconi soon developed a system that was transmitting signals way beyond distances anyone could have predicted (due in part to the signals bouncing off the then unknown ionosphere). Marconi and Karl Ferdinand Braun were awarded the 1909 Nobel Prize for Physics for their contribution to this form of wireless telegraphy. Millimetre wave communication was first investigated by Jagadish Chandra Bose during 1894–1896, when he reached an extremely high frequency of up to 60 GHz in his experiments. He also introduced the use of semiconductor junctions to detect radio waves, when he patented the radio crystal detector in 1901. The wireless revolution began in the 1990s, with the advent of digital wireless networks leading to a social revolution, and a paradigm shift from wired to wireless technology, including the proliferation of commercial wireless technologies such as cell phones, mobile telephony, pagers, wireless computer networks, cellular networks, the wireless Internet, and laptop and handheld computers with wireless connections. The wireless revolution has been driven by advances in radio frequency (RF), microelectronics, and microwave engineering, and the transition from analog to digital RF technology, which enabled a substantial increase in voice traffic along with the delivery of digital data such as text messaging, images and streaming media. Modes Wireless communications can be via: Radio and microwave communication carry information by modulating properties of electromagnetic waves transmitted through space. Specifically, the transmitter generates artificial electromagnetic waves by applying time-varying electric currents to its antenna. The waves travel away from the antenna until they eventually reach the antenna of a receiver, which induces an electric current in the receiving antenna. This current can be detected and demodulated to recreate the information sent by the transmitter. Optical wireless communications (OWC) is a form of optical communication in which unguided light is used "in the air" (or in outer space), without an optical fiber. Visible, infrared (IR), or ultraviolet (UV) light is used to carry a wireless signal. It is generally used in short-range communication; extensions exist for long-range and ultra-long range. OWC systems operating in the visible band (390–750 nm) are commonly referred to as visible light communication (VLC). VLC systems take advantage of light-emitting diodes (LEDs) which can be pulsed at very high speeds without a noticeable effect on the lighting output and human eye. VLC can be possibly used in a wide range of applications including wireless local area networks, wireless personal area networks and vehicular networks, among others. On the other hand, terrestrial point-to-point OWC systems, also known as the free space optical (FSO) systems, operate at the near IR frequencies (750–1600 nm). These systems typically use laser transmitters and offer a cost-effective protocol-transparent link with high data rates, i.e., 10 Gbit/s per wavelength, and provide a potential solution for the backhaul bottleneck. There has also been a growing interest in ultraviolet communication (UVC) as a result of recent progress in solid-state optical sources/detectors operating within solar-blind UV spectrum (200–280 nm). In this so-called deep UV band, solar radiation is negligible at the ground level and this makes possible the design of photon-counting detectors with wide field-of-view receivers that increase the received energy with little additional background noise. Such designs are particularly useful for outdoor non-line-of-sight configurations to support low-power short-range UVC such as in wireless sensors and ad-hoc networks. Free-space optical communication (FSO) is an optical communication technology that uses light propagating in free space to transmit wireless data for telecommunications or computer networking. "Free space" means the light beams travel through the open air or outer space. This contrasts with other communication technologies that use light beams traveling through transmission lines such as optical fiber or dielectric "light pipes". The technology is useful where physical connections are impractical due to high costs or other considerations. For example, free space optical links are used in cities between office buildings that are not wired for networking, where the cost of running cable through the building and under the street would be prohibitive. Another widely used example is consumer IR devices such as remote controls and IrDA (Infrared Data Association) networking, which is used as an alternative to WiFi networking to allow laptops, PDAs, printers, and digital cameras to exchange data. Sonic, especially ultrasonic short-range communication involves the transmission and reception of sound. Electromagnetic induction only allows short-range communication and power transmission. It has been used in biomedical situations such as pacemakers, as well as for short-range RFID tags. Services Common examples of wireless equipment include: Electromagnetic spectrum AM and FM radios and other electronic devices make use of the electromagnetic spectrum. The frequencies of the radio spectrum that are available for use for communication are treated as a public resource and are regulated by organizations such as the American Federal Communications Commission, Ofcom in the United Kingdom, the international ITU-R or the European ETSI. Their regulations determine which frequency ranges can be used for what purpose and by whom. In the absence of such control or alternative arrangements such as a privatized electromagnetic spectrum, chaos might result if, for example, airlines did not have specific frequencies to work under and an amateur radio operator was interfering with a pilot's ability to land an aircraft. Wireless communication spans the spectrum from 9 kHz to 300 GHz.[citation needed] Applications One of the best-known examples of wireless technology is the mobile phone, also known as a cellular phone, with more than 6.6 billion mobile cellular subscriptions worldwide as of the end of 2010. These wireless phones use radio waves from signal-transmission towers to enable their users to make phone calls from many locations worldwide. They can be used within the range of the mobile telephone site used to house the equipment required to transmit and receive the radio signals from these instruments. Wireless data communications allow wireless networking between desktop computers, laptops, tablet computers, cell phones, and other related devices. The various available technologies differ in local availability, coverage range, and performance, and in some circumstances, users employ multiple connection types and switch between them using connection manager software or a mobile VPN to handle the multiple connections as a secure, single virtual network. Supporting technologies include: Wireless data communications are used to span a distance beyond the capabilities of typical cabling in point-to-point communication and point-to-multipoint communication, to provide a backup communications link in case of normal network failure, to link portable or temporary workstations, to overcome situations where normal cabling is difficult or financially impractical, or to remotely connect mobile users or networks. Peripheral devices in computing can also be connected wirelessly, as part of a Wi-Fi network or directly via an optical or radio-frequency (RF) peripheral interface. Originally these units used bulky, highly local transceivers to mediate between a computer and a keyboard and mouse; however, more recent generations have used smaller, higher-performance devices. Radio-frequency interfaces, such as Bluetooth or Wireless USB, provide greater ranges of efficient use, usually up to 10 feet, but distance, physical obstacles, competing signals, and even human bodies can all degrade the signal quality. Concerns about the security of wireless keyboards arose at the end of 2007 when it was revealed that Microsoft's implementation of encryption in some of its 27 MHz models were highly insecure. Wireless energy transfer is a process whereby electrical energy is transmitted from a power source to an electrical load that does not have a built-in power source, without the use of interconnecting wires. There are two different fundamental methods for wireless energy transfer. Energy can be transferred using either far-field methods that involve beaming power/lasers, radio or microwave transmissions, or near-field using electromagnetic induction. Wireless energy transfer may be combined with wireless information transmission in what is known as Wireless Powered Communication. In 2015, researchers at the University of Washington demonstrated far-field energy transfer using Wi-Fi signals to power cameras. New wireless technologies, such as mobile body area networks (MBAN), have the capability to monitor blood pressure, heart rate, oxygen level, and body temperature. The MBAN works by sending low-powered wireless signals to receivers that feed into nursing stations or monitoring sites. This technology helps with the intentional and unintentional risk of infection or disconnection that arise from wired connections. Categories of implementations, devices, and standards See also References Further reading External links |
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[SOURCE: https://en.wikipedia.org/wiki/Category:Articles_containing_Chinese-language_text] | [TOKENS: 159] |
Category:Articles containing Chinese-language text This category contains articles with Chinese-language text. The primary purpose of these categories is to facilitate manual or automated checking of text in other languages. This category should only be added with the {{Lang}} family of templates, never explicitly. For example {{Lang|zh|楷書}}, which wraps the text with <span lang="zh">. Also available is {{Langx|zh|楷書}} which displays as Chinese: 楷書. See also Subcategories This category has the following 16 subcategories, out of 16 total. Pages in category "Articles containing Chinese-language text" The following 200 pages are in this category, out of approximately 67,095 total. This list may not reflect recent changes. |
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[SOURCE: https://en.wikipedia.org/wiki/Nicholas_of_Cusa] | [TOKENS: 3111] |
Contents Nicholas of Cusa Nicholas of Cusa (1401 – 11 August 1464), also referred to as Nicholas of Kues and Nicolaus Cusanus (/kjuːˈseɪnəs/), was a German Catholic bishop and polymath active as a philosopher, theologian, jurist, mathematician, and astronomer. One of the first German proponents of Renaissance humanism, he made spiritual and political contributions to European culture. A notable example of this is his mystical or spiritual writings on "learned ignorance", as well as his participation in power struggles between Rome and the German states of the Holy Roman Empire. As papal legate to Germany from 1446, he was appointed cardinal for his merits by Pope Nicholas V in 1448 and Prince-Bishop of Brixen two years later. In 1459, he became vicar general in the Papal States. Nicholas has remained an influential figure. In 2001, the sixth centennial of his birth was celebrated on four continents and commemorated by publications on his life and work. Life Nicholas was born in Kues (Latinized as "Cusa") in southwestern Germany. He was the second of four children of Johan Krebs (or Cryfftz) and Katherina Roemer. His father was "a prosperous boat owner and ferryman." Nicholas entered the Faculty of Arts of the Heidelberg University in 1416 as "a cleric of the Diocese of Trier," studying the liberal arts. He seemed to have left Heidelberg soon afterwards, as he received his doctorate in canon law from the University of Padua in 1423. In Padua, he met the later cardinals Julian Cesarini and Domenico Capranica and became friends with the mathematician Paolo dal Pozzo Toscanelli. Afterwards, he entered the University of Cologne in 1425 as "a doctor of canon law," which he appears to have both taught and practiced there. In Cologne, he made friends with the scholastic theologian Heymeric de Campo. Following a brief period in Cologne, Nicholas returned to his hometown and became secretary to Otto of Ziegenhain, the Prince-Archbishop of Trier. Otto appointed him canon and dean at the stift of Saint Florinus in Koblenz affiliated with numerous prebends. In 1427 he was sent to Rome as an episcopal delegate. The next year he travelled to Paris to study the writings of Ramon Llull. At the same time he rejected a calling by the newly established University of Leuven. He acquired great knowledge in the research of ancient and medieval manuscripts as well as in textual criticism and the examination of primary sources. In 1433 he identified the Donation of Constantine as a fake, confirmed by Lorenzo Valla a few years later, and revealed the forgery of the Pseudo-Isidorian Decretals. He made friends with the Austrian astronomer Georg von Peuerbach and advocated a reform of the Julian calendar and the Easter computus, which, however, was not realized until the introduction of the Gregorian calendar in 1582. After the Archbishop Otto of Trier had died in 1430, Pope Martin V appointed the Speyer bishop Raban of Helmstatt his successor. Nevertheless, the Electorate was contested by opposing parties, and in 1432 Nicholas attended the Council of Basel representing the Cologne dean Ulrich von Manderscheid, one of the claimants, who hoped to prevail against the new Pope Eugene IV. Nicholas stressed the determining influence of the cathedral chapter and its given right to participate in the succession policy, which even places the pope under an obligation to seek a consent. His efforts were to no avail in regard to Ulrich's ambitions; however, Nicholas's pleadings earned him a great reputation as an intermediary and diplomat. While present at the council, he wrote his first work, De concordantia catholica (The Catholic Concordance), a synthesis of ideas on church and empire balancing hierarchy with consent. This work remained useful to critics of the papacy long after Nicholas left Basel. Initially as conciliarist, Nicholas approached his university friend Cardinal Julian Cesarini, who had tried to reconcile pope and council, combining reform and hierarchic order. Nicholas supported transfer of the council to Italy to meet with the Greeks, who needed aid against the Ottoman Turks. He arbitrated in the conflict with the Hussites. Between the summer of 1437 and early 1438 he was a member of the delegation sent to Constantinople with the pope's approval to bring back the Byzantine emperor and his representatives to the papally summoned Council of Florence of 1439, which was attempting to bring the Eastern Orthodox Church into union with the Western Catholic Church. The reunion achieved at this conference turned out to be very brief. Nicholas would later claim (in the postfaced dedicatory letter of On Learned Ignorance, which Nicholas finished writing on 12 February 1440) that he had chosen to write on this metaphysical topic because of a shipboard experience of divine illumination while on the ship returning from this mission to Constantinople. After a successful career as a papal envoy, he was made a cardinal by Pope Nicholas V in 1448 or 1449. In 1450 he was both named Bishop of Brixen, in Tyrol, and commissioned as a papal legate to the German lands to spread the message of reform. In 1444, the White Tower of Brixen caught fire and in 1459 he commissioned its reconstruction in a Gothic style. This latter role, his 'Great Legation' of 1450–1452, involved travel of almost 3000 miles, preaching, teaching and reforming. He became known as the "Hercules of the Eugenian cause." His local councils enacted reforms, many of which were not successful. Pope Nicholas canceled some of Nicholas's decrees, and the effort to discourage pilgrimages to venerate the bleeding hosts of Wilsnack (the so-called Holy Blood of Wilsnack) was unsuccessful. His work as bishop between 1452 and 1458 – trying to impose reforms and reclaim lost diocesan revenues – was opposed by Duke Sigismund of Austria. The duke imprisoned Nicholas in 1460, for which Pope Pius II excommunicated Sigismund and laid an interdict on his lands. Nicholas returned to Rome, but was never able to return to his bishopric. He died at Todi in Umbria on 11 August 1464. Sigismund's capitulation came a few days after Nicholas's death. Upon his death, Nicholas's body was interred in the church of San Pietro in Vincoli in Rome, probably near the relic of Peter's chains; but it was later lost. His monument, with a sculpted image of the cardinal, remains. Two other tombstones, one medieval and one modern, also are found in the church. In accordance with his wishes, his heart rests within the chapel altar at the Cusanusstift in Kues. To this charitable institution that he had founded he bequeathed his entire inheritance; it still stands, and serves the purpose Nicholas intended for it, as a home for the aged. The Cusanusstift also houses many of his manuscripts. Philosophy Nicholas's De Docta Ignorantia ('Of Learned Ignorance') is an epistemological and metaphysical treatise. He maintains the finite human mind cannot fully know the divine, infinite mind ('the Maximum'). Nonetheless, he holds that the human intellect can become aware of its limitations in knowing God and thus attain "learned ignorance". His theory shows the influence of neoplatonism and negative theology, and he frequently cites Pseudo-Dionysius the Areopagite. Nicholas was noted for his deeply mystical writings about Christianity. He wrote of the enfolding of creation in God and their unfolding in creation. He was suspected by some of holding pantheistic beliefs, but his writings were never accused of being heretical. Nicholas also wrote in De coniecturis about using conjectures or surmises to rise to better understanding of the truth. The individual might rise above mere reason to the vision of the intellect, but the same person might fall back from such vision. Theologically, Nicholas anticipated the implications of Reformed teaching on the harrowing of Hell (Sermon on Psalm 30:11), followed by Pico della Mirandola, who similarly explained the descensus in terms of Christ's agony. Science and mathematics Most of Nicholas's mathematical ideas can be found in his essays, De Docta Ignorantia (Of Learned Ignorance), De Visione Dei (On the Vision of God) and De coniecturis (On Conjectures). He also wrote on squaring the circle in his mathematical treatises. Mathematics plays a key role for Cusanus in orienting the human mind towards God. Mathematical figures provide a means for the mind to consider how figures may be deformed and transformed, and thus prepares the mind to reach the "coincidence of opposites" in the "Absolutely maximal Being". From the Catholic Encyclopedia (1913 edition): The astronomical views of the cardinal are scattered through his philosophical treatises. They evince complete independence of traditional doctrines, though they are based on symbolism of numbers, on combinations of letters, and on abstract speculations rather than observation. The earth is a star like other stars, is not the centre of the universe, is not at rest, nor are its poles fixed. The celestial bodies are not strictly spherical, nor are their orbits circular. The difference between theory and appearance is explained by relative motion. Had Copernicus been aware of these assertions he would probably have been encouraged by them to publish his own monumental work. Like Nicole Oresme, Nicholas also wrote about the possibility of the plurality of worlds. Norman Moore tells us in The Fitz-Patrick Lectures of 1905: In medicine he introduced an improvement which in an altered form has continued in use to this day. This improvement was the counting of the pulse which up to his time had been felt and discussed in many ways but never counted. ...Nicholas of Cusa proposed to compare the rate of pulses by weighing the quantity of water run out of a water clock while the pulse beat one hundred times. ...The manufacture of watches with second-hands has since given us a simpler method of counting, but the merit of introducing this useful kind of observation into clinical medicine belongs to Nicholas of Cusa. Politics In 1433, Nicholas proposed reform of the Holy Roman Empire and a method to elect Holy Roman Emperors. Although it was not adopted by the Church, his method was essentially the same one known today as the Borda count, which is used in many academic institutions, competitions, and even some political jurisdictions, in original form and a number of variations. His proposal preceded Borda's work by over three centuries. Nicholas's opinions on the Empire, which he hoped to reform and strengthen, were cited against papal claims of temporal power in the sixteenth and seventeenth centuries. Protestant writers were happy to cite a cardinal against Rome's assertions. Protestants, however, found his writings against the Hussites wrong. Nicholas seemed to Protestants to give the church too much power to interpret Scripture, instead of treating it as self-interpreting and self-sufficient for salvation, the principle of sola scriptura. Nicholas's own thought on the church changed with his departure from Basel. He tried arguing that the Basel assembly lacked the consent of the church throughout the world, especially the princes. Then he tried arguing that the church was unfolded from Peter (explicatio Petri). This allowed him to support the pope without abandoning ideas of reform. Thus, he was able to propose to Pius II reform of the church, beginning with the pope himself. Then it was to spread through the Roman curia and outward throughout Christendom. Nicholas noted that government was founded on the consent of the governed: Other religions Shortly after the Fall of Constantinople in 1453, Nicholas wrote De pace fidei, On the Peace of Faith. This visionary work imagined a summit meeting in Heaven of representatives of all nations and religions. Islam and the Hussite movement in Bohemia are represented. The conference agrees that there can be una religio in varietate rituum, a single faith manifested in different rites, as manifested in the eastern and western rites of the Catholic Church. The dialogue presupposes the greater accuracy of Christianity but gives respect to other religions. Nicholas's position was for Europeans not to retake Constantinople but simply to trade with the Ottomans and allow them their conquests. Less irenic but not virulent, is his Cribratio Alchorani, Sifting the Koran, a detailed review of the Koran in Latin translation. While the arguments for the superiority of Christianity are still shown in this book, it also credits Judaism and Islam with sharing in the truth at least partially. Influence Nicholas was widely read, and his works were published in the sixteenth century in both Paris and Basel. Sixteenth-century French scholars, including Jacques Lefèvre d'Étaples and Charles de Bovelles, cited him. Lefèvre even edited the Paris 1514 Opera. Nonetheless, there was no Cusan school, and his works were largely unknown until the nineteenth century, though Giordano Bruno quoted him, while some thinkers, like Gottfried Leibniz, were thought to have been influenced by him. Neo-Kantian scholars began studying Nicholas in the nineteenth century, and new editions were begun by the Heidelberger Akademie der Wissenschaften in the 1930s and published by Felix Meiner Verlag. In the early twentieth century, he was hailed by Ernst Cassirer as the "first modern thinker," and much debate since then has centered around the question whether he should be seen as essentially a medieval or Renaissance figure. What is more, Cassirer presented Cusanus as the main focal point (einfachen Brennpunkt) of Italian Renaissance philosophy. Eminent scholars like Eugenio Garin and Paul Oskar Kristeller challenged Cassirer’s thesis, and went so far as to practically deny any considerable link between Nicholas of Cusa and Marsilio Ficino or Giovanni Pico. In the following decades, new hypotheses on the relationship between Cusanus and Italian humanists appeared, more balanced and focused on the sources. Societies and centers dedicated to Nicholas can be found in Argentina, Japan, Germany, Italy and the United States. His well-known quote about the infinity of the universe is found paraphrased in the Central Holy Book of the Thelemites, The Book of the Law, which was "received" from the Angel Aiwass by Aleister Crowley in Cairo in April 1904: "In the sphere I am everywhere the centre, as she, the circumference, is nowhere found." Works Nicholas wrote a large number of works, which include: See also References Further reading English language Other languages External links |
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[SOURCE: https://en.wikipedia.org/wiki/History_of_the_Jews_in_Jamaica] | [TOKENS: 1635] |
Contents History of the Jews in Jamaica The history of the Jews in Jamaica predominantly dates back to migrants from Spain and Portugal. Starting in 1509, many Jews began fleeing from Spain because of the persecution of the Holy Inquisition. When the English captured Jamaica from Spain in 1655, the Jews who were living as conversos began to practice Judaism openly. By 1611, the Island of Jamaica had reached an estimated population of 2,500 people. History The first Jews came to the island during the Spanish occupation of the Island, 1494–1655. With the influx of Jews to Jamaica in the 17th century, multiple synagogues were constructed across the island in such cities as Montego Bay, Spanish Town, Port Royal, and Kingston. A synagogue built in Spanish Town, the Sephardic Kahal Kadosh Neveh Shalom ("Habitation of Peace"), was consecrated in 1704. Jews came from Spain and Portugal, having fled the Spanish Inquisition. During the Spanish Inquisition, the Spanish government required the Jews to leave the country or convert to Catholicism. The punishment for disobedience was death. To conceal their identity they referred to themselves as "Portuguese" or "Spanish" and practiced their religion secretly. At the time of the English conquest of the island in 1655, General Robert Venables recorded the presence of many "Portuguese" in Jamaica. Details pertaining to how many times or any of these Portuguese were Jews or New Christians is unknown. Also, it is unclear how many of these possible New Christians converted to Judaism. The Portuguese on the island were often persecuted by the Spanish and so many helped the English with their invasion. The Jews were allowed to remain after the conquest and began to practice their religion openly. They were granted English citizenship by Oliver Cromwell, which was confirmed in 1660 by King Charles II of England. For many Jews, Jamaica became a safe place they could live in without fear of persecution. Jews from Amsterdam, Bordeaux, and Bayonne moved to Jamaica, mostly residing in Port Royal. Port Royal even had what was called a Jew Street. In 1672 thirty-one Port Royal merchants petitioned the governor complaining of large numbers of Jewish retail merchants active on the island. Abraham Blauvelt was a Dutch-Jewish pirate, privateer, and explorer of Central America and the western Caribbean, after whom the towns of Bluefields, Nicaragua, and Bluefields, Jamaica, were both named. In 1719, the synagogue Kahal Kadosh Neve Tsedek was built. It was originally planned to turn Jamaica into an agricultural powerhouse, but this plan failed. However, for local merchants, Port Royal became a successful center for trade. Port Royal became an attractive place to trade commodities such as gold, silver, porcelain, embroidery, and silk. The Jews participated as well, particularly in the trade of silver and gold, and in money-changing. This success, however, led to a backlash. English-Jamaican merchants accused Jamaican Jews of coin clipping, a method of shaving off precious metal from money and putting it back into circulation at face value. Such accusations occurred many times. This resentment led to the coalition of a Legislative Council that represented English-Jamaican merchants and planters in 1691. For example, the Council petitioned to the Crown that Jamaican Jews were evading taxes. Some have found these accusations to be false or exaggerated because the Jews did not play a large role in the economics of Port Royal. In 1815, a fire nearly destroyed all of Port Royal. Many Jews left Port Royal for another Jamaican town called Kingston, where a new economy was flourishing with commercial success. The Jews in Kingston provided four Mayors, many Justices of Peace, members of Parliament, and countless builders, dentists, doctors, teachers, lawyers, and actors. The community of Ashkenazi Jews in Kingston were called "The English and German Congregation." In 1787, they built a synagogue called Shangare Yosher. There had been an Ashkenazi synagogue in the nineteenth century called Rodphei Zadek, but it was later united with a Sephardic congregation in 1850. By 1720, 18 percent of the population of Kingston was Jewish. For the most part, Jews practiced Orthodox rituals and customs. Among the Jewish community's religious leaders during the early 1800s was the Rev. Dr. Isaac Lopez (1780-1854). Born in Curacao, he came to Kingston where he served the congregation there, assisted for a time by Abraham Pereira Mendes who was later called to be the minister of the Montego community. At the beginning of the twentieth century, the Jewish population began introducing Progressive Judaism into their rituals. Progressive Judaism had a combination of reform and conservative rituals. Since the Inquisition made its way to many parts of the New World, Jamaica offered a type of haven for the Jews. The Jews in Jamaica felt at peace with life even though they still faced certain restrictions such as not being able to vote or hold office. In 1826, however, free people of color were on track to gain equal rights to others in Jamaica, and the Jewish community noticed the possible threat of being the only group in Jamaica without voting rights. Thus, the Jews decided to fight for their right through petitions to the English government. They attained full political rights in 1831. The status of British citizenship enabled ownership of property by the Jews. This victory proved to be significant not just for the Jews of Jamaica but also elsewhere. In 1832, Jews in London used the victory in Jamaica as reasoning for their own rights to such freedoms. That same year in Canada, a similar story unfolded as Jews were granted same political rights as their Christian counterparts. Jamaica's Jewish population was never large. However, their contribution to the economic and commercial life of the nation has been significant.[citation needed] Only 506 people are religiously practicing Jews in Jamaica and most Jews have migrated out of Jamaica. While many are non-practicing, it is recorded that over 2,000 Jamaicans religiously identify as Jews.[citation needed] Common Jewish surnames in Jamaica with mostly Portuguese origin are Abrahams, Alexander, Andrade, Barrett, Babb, Benjamin, Bent, Carvalho, Codner, D'Aguilar, Israel ,DeCosta, De La Roche, Da Silva, De Souza, Pimentel, De Cohen, De Leon, Delisser, DeMercado, Eben, Fuertado, Henriques, Ibanez, Isaacs, Levy, Lindo, Lyon, Machado, Morais, Matalon, Mendes, Myers, Magnus, Nunes, Pimentel, Reuben, Rodriques, Sangster. Some of these surnames were then made to sound more English, in order to 'blend' with the British-Jamaican community. An example would be De La Roche being changed to Roach(e) and Eben /Ibanez changed to Ebanks.[citation needed] The Chabad-Lubavitch movement opened a branch in Jamaica in 2014 servicing locals as well as a welcome centre for international visitors. The Shaare Shalom Synagogue in Kingston, first built in 1885, was the only synagogue in the country until 2014 when Chabad opened the second synagogue in Montego Bay. The congregation has its own siddur, blending together Spanish-Portuguese tradition and British Liberal and American Reform liturgy. The Hillel Academy, a private school founded by the Jewish community, today is non-denominational but still serves as a meeting place for the children of the Jewish community. A Jamaican Jewish Heritage Center opened in 2006 in celebration of 350 years of Jews living in Jamaica. At least 21 Jewish cemeteries also exist in the country. Notable people with Jamaican Jewish ancestry See also References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Geoid] | [TOKENS: 3480] |
Contents Geoid The geoid (/ˈdʒiː.ɔɪd/ JEE-oyd) is the shape that the ocean surface would take under the influence of the gravity of Earth, including gravitational attraction and Earth's rotation, if other influences such as winds and tides were absent. This surface is extended through the continents (such as might be approximated with very narrow hypothetical canals). According to Carl Friedrich Gauss, who first described it, it is the "mathematical figure of the Earth", a smooth but irregular surface whose shape results from the uneven distribution of mass within and on the surface of Earth. It can be known only through extensive gravitational measurements and calculations. Despite being an important concept for almost 200 years in the history of geodesy and geophysics, it was not defined with any degree of precision until the advent of satellite geodesy in the mid-20th century. Mathematician Gladys West was the first worker to synthesize a high-fidelity geoid from this satellite data. The geoid is one of the essential components of satellite-based global positioning systems. The geoid is often expressed as a geoid undulation or geoidal height above a given reference ellipsoid, which is a slightly flattened sphere whose equatorial bulge is caused by the planet's rotation. Generally the geoidal height rises where the Earth's material is locally more dense and exerts greater gravitational force than the surrounding areas. The geoid in turn serves as a reference coordinate surface for various vertical coordinates, such as orthometric heights, geopotential heights, and dynamic heights (see Geodesy). All points on a geoid surface have the same geopotential (the sum of gravitational potential energy and centrifugal potential energy). At this surface, apart from temporary tidal fluctuations, the force of gravity acts everywhere perpendicular to the geoid, meaning that plumb lines point perpendicular and bubble levels are parallel to the geoid. Being an equigeopotential means the geoid corresponds to the free surface of water at rest (if only the Earth's gravity and rotational acceleration were at work); this is also a sufficient condition for a ball to remain at rest instead of rolling over the geoid. Earth's gravity acceleration (the vertical derivative of geopotential) is thus non-uniform over the geoid. Description The geoid surface is irregular, unlike the reference ellipsoid (which is a mathematical idealized representation of the physical Earth as an ellipsoid), but is considerably smoother than Earth's physical surface. Although the "ground" of the Earth has excursions on the order of +8,800 m (Mount Everest) and −11,000 m (Marianas Trench), the geoid's deviation from an ellipsoid ranges from +85 m (Iceland) to −106 m (southern India), less than 200 m total. If the ocean were of constant density and undisturbed by tides, currents or weather, its surface would resemble the geoid. The permanent deviation between the geoid and mean sea level is called ocean surface topography. If the continental land masses were crisscrossed by a series of tunnels or canals, the sea level in those canals would also very nearly coincide with the geoid. Geodesists are able to derive the heights of continental points above the geoid by spirit leveling. Being an equipotential surface, the geoid is, by definition, a surface upon which the force of gravity is perpendicular everywhere, apart from temporary tidal fluctuations. This means that when traveling by ship, one does not notice the undulation of the geoid; neglecting tides, the local vertical (plumb line) is always perpendicular to the geoid and the local horizon tangential to it. Likewise, spirit levels will always be parallel to the geoid. Earth's gravitational field is not uniform. An oblate spheroid is typically used as the idealized Earth, but even if the Earth were spherical and did not rotate, the strength of gravity would not be the same everywhere because density varies throughout the planet. This is due to magma distributions, the density and weight of different geological compositions in the Earth's crust, mountain ranges, deep sea trenches, crust compaction due to glaciers, and so on. If that sphere were then covered in water, the water would not be the same height everywhere. Instead, the water level would be higher or lower with respect to Earth's center, depending on the integral of the strength of gravity from the center of the Earth to that location. The geoid level coincides with where the water would be. Generally the geoid rises where the Earth's material is locally more dense, exerts greater gravitational force, and pulls more water from the surrounding area. Formulation The geoid undulation (also known as geoid height or geoid anomaly), N, is the height of the geoid relative to a given ellipsoid of reference. N = h − H {\displaystyle N=h-H} The undulation is not standardized, as different countries use different mean sea levels as reference, but most commonly refers to the EGM96 geoid. In maps and common use, the height over the mean sea level (such as orthometric height, H) is used to indicate the height of elevations while the ellipsoidal height, h, results from the GPS system and similar GNSS: H = h − N {\displaystyle H=h-N} (An analogous relationship exists between normal heights and the quasigeoid, which disregards local density variations.) In practice, many handheld GPS receivers interpolate N in a pre-computed geoid map (a lookup table). So a GPS receiver on a ship may, during the course of a long voyage, indicate height variations, even though the ship will always be at sea level (neglecting the effects of tides). That is because GPS satellites, orbiting about the center of gravity of the Earth, can measure heights only relative to a geocentric reference ellipsoid. To obtain one's orthometric height, a raw GPS reading must be corrected. Conversely, height determined by spirit leveling from a tide gauge, as in traditional land surveying, is closer to orthometric height. Modern GPS receivers have a grid implemented in their software by which they obtain, from the current position, the height of the geoid (e.g., the EGM96 geoid) over the World Geodetic System (WGS) ellipsoid. They are then able to correct the height above the WGS ellipsoid to the height above the EGM96 geoid. When height is not zero on a ship, the discrepancy is due to other factors such as ocean tides, atmospheric pressure (meteorological effects), local sea surface topography, and measurement uncertainties. Determination The undulation of the geoid N is closely related to the disturbing potential T according to Bruns' formula (named after Heinrich Bruns): where γ {\displaystyle \gamma } is the force of normal gravity, computed from the normal field potential U {\displaystyle U} . Another way of determining N is using values of gravity anomaly Δ g {\displaystyle \Delta g} , differences between true and normal reference gravity, as per Stokes formula (or Stokes' integral), published in 1849 by George Gabriel Stokes: The integral kernel S, called Stokes function, was derived by Stokes in closed analytical form. Note that determining N {\displaystyle N} anywhere on Earth by this formula requires Δ g {\displaystyle \Delta g} to be known everywhere on Earth, including oceans, polar areas, and deserts. For terrestrial gravimetric measurements this is a near-impossibility, in spite of close international co-operation within the International Association of Geodesy (IAG), e.g., through the International Gravity Bureau (BGI, Bureau Gravimétrique International). Another approach for geoid determination is to combine multiple information sources: not just terrestrial gravimetry, but also satellite geodetic data on the figure of the Earth, from analysis of satellite orbital perturbations, and lately from satellite gravity missions such as GOCE and GRACE. In such combination solutions, the low-resolution part of the geoid solution is provided by the satellite data, while a 'tuned' version of the above Stokes equation is used to calculate the high-resolution part, from terrestrial gravimetric data from a neighbourhood of the evaluation point only. Calculating the undulation is mathematically challenging. The precise geoid solution by Petr Vaníček and co-workers improved on the Stokesian approach to geoid computation. Their solution enables millimetre-to-centimetre accuracy in geoid computation, an order-of-magnitude improvement from previous classical solutions. Geoid undulations display uncertainties which can be estimated by using several methods, e.g., least-squares collocation (LSC), fuzzy logic, artificial neural networks, radial basis functions (RBF), and geostatistical techniques. Geostatistical approach has been defined as the most-improved technique in prediction of geoid undulation. Relationship to mass density Variations in the height of the geoidal surface are related to anomalous density distributions within the Earth. Geoid measures thus help understanding the internal structure of the planet. Synthetic calculations show that the geoidal signature of a thickened crust (for example, in orogenic belts produced by continental collision) is positive, opposite to what should be expected if the thickening affects the entire lithosphere. Mantle convection also changes the shape of the geoid over time. The surface of the geoid is higher than the reference ellipsoid wherever there is a positive gravity anomaly or negative disturbing potential (mass excess) and lower than the reference ellipsoid wherever there is a negative gravity anomaly or positive disturbing potential (mass deficit). This relationship can be understood by recalling that gravity potential is defined so that it has negative values and is inversely proportional to distance from the body. So, while a mass excess will strengthen the gravity acceleration, it will decrease the gravity potential. As a consequence, the geoid's defining equipotential surface will be found displaced away from the mass excess. Analogously, a mass deficit will weaken the gravity pull but will increase the geopotential at a given distance, causing the geoid to move towards the mass deficit. The presence of a localized inclusion in the background medium will rotate the gravity acceleration vectors slightly towards or away from a denser or lighter body, respectively, causing a bump or dimple in the equipotential surface. The largest absolute deviation can be found in the Indian Ocean Geoid Low, 106 meters below the average sea level. Another large feature is the North Atlantic Geoid High (or North Atlantic Geoid Swell), caused in part by the weight of ice cover over North America and northern Europe in the Late Cenozoic Ice Age. Temporal change Recent satellite missions, such as the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) and GRACE, have enabled the study of time-variable geoid signals. The first products based on GOCE satellite data became available online in June 2010, through the European Space Agency. ESA launched the satellite in March 2009 on a mission to map Earth's gravity with unprecedented accuracy and spatial resolution. On 31 March 2011, a new geoid model was unveiled at the Fourth International GOCE User Workshop hosted at the Technical University of Munich, Germany. Studies using the time-variable geoid computed from GRACE data have provided information on global hydrologic cycles, mass balances of ice sheets, and postglacial rebound. From postglacial rebound measurements, time-variable GRACE data can be used to deduce the viscosity of Earth's mantle. Spherical harmonics representation Spherical harmonics are often used to approximate the shape of the geoid. The current best such set of spherical harmonic coefficients is EGM2020 (Earth Gravitational Model 2020), determined in an international collaborative project led by the National Imagery and Mapping Agency (now the National Geospatial-Intelligence Agency, or NGA). The mathematical description of the non-rotating part of the potential function in this model is: V = G M r ( 1 + ∑ n = 2 n max ( a r ) n ∑ m = 0 n P ¯ n m ( sin ϕ ) [ C ¯ n m cos m λ + S ¯ n m sin m λ ] ) , {\displaystyle V={\frac {GM}{r}}\left(1+{\sum _{n=2}^{n_{\text{max}}}}\left({\frac {a}{r}}\right)^{n}{\sum _{m=0}^{n}}{\overline {P}}_{nm}(\sin \phi )\left[{\overline {C}}_{nm}\cos m\lambda +{\overline {S}}_{nm}\sin m\lambda \right]\right),} where ϕ {\displaystyle \phi \ } and λ {\displaystyle \lambda \ } are geocentric (spherical) latitude and longitude respectively, P ¯ n m {\displaystyle {\overline {P}}_{nm}} are the fully normalized associated Legendre polynomials of degree n {\displaystyle n\ } and order m {\displaystyle m\ } , and C ¯ n m {\displaystyle {\overline {C}}_{nm}} and S ¯ n m {\displaystyle {\overline {S}}_{nm}} are the numerical coefficients of the model based on measured data. The above equation describes the Earth's gravitational potential V {\displaystyle V} , not the geoid itself, at location ϕ , λ , r , {\displaystyle \phi ,\;\lambda ,\;r,\ } the co-ordinate r {\displaystyle r\ } being the geocentric radius, i.e., distance from the Earth's centre. The geoid is a particular equipotential surface, and is somewhat involved to compute. The gradient of this potential also provides a model of the gravitational acceleration. The most commonly used EGM96 contains a full set of coefficients to degree and order 360 (i.e., n max = 360 {\displaystyle n_{\text{max}}=360} ), describing details in the global geoid as small as 55 km (or 110 km, depending on the definition of resolution). The number of coefficients, C ¯ n m {\displaystyle {\overline {C}}_{nm}} and S ¯ n m {\displaystyle {\overline {S}}_{nm}} , can be determined by first observing in the equation for V {\displaystyle V} that for a specific value of n {\displaystyle n} there are two coefficients for every value of m {\displaystyle m} except for m = 0 {\displaystyle m=0} . There is only one coefficient when m = 0 {\displaystyle m=0} since sin ( 0 λ ) = 0 {\displaystyle \sin(0\lambda )=0} . There are thus ( 2 n + 1 ) {\displaystyle (2n+1)} coefficients for every value of n {\displaystyle n} . Using these facts and the formula, ∑ I = 1 L I = 1 2 L ( L + 1 ) {\textstyle \sum _{I=1}^{L}I={\frac {1}{2}}L(L+1)} , it follows that the total number of coefficients is given by ∑ n = 2 n max ( 2 n + 1 ) = n max ( n max + 1 ) + n max − 3 = 130317 {\displaystyle \sum _{n=2}^{n_{\text{max}}}(2n+1)=n_{\text{max}}(n_{\text{max}}+1)+n_{\text{max}}-3=130317} using the EGM96 value of n max = 360 {\displaystyle n_{\text{max}}=360} . For many applications, the complete series is unnecessarily complex and is truncated after a few (perhaps several dozen) terms. Still, even higher resolution models have been developed. Many of the authors of EGM96 have published EGM2008. It incorporates much of the new satellite gravity data (e.g., the Gravity Recovery and Climate Experiment), and supports up to degree and order 2160 (1/6 of a degree, requiring over 4 million coefficients), with additional coefficients extending to degree 2190 and order 2159. EGM2020 is the international follow-up that was originally scheduled for 2020 (still unreleased in 2025), containing the same number of harmonics generated with better data. See also References Further reading External links |
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Contents Objective-C Objective-C is a high-level general-purpose, object-oriented programming language that adds Smalltalk-style message passing (messaging) to the C programming language. Originally developed by Brad Cox and Tom Love in the early 1980s, it was selected by NeXT for its NeXTSTEP operating system. Due to Apple macOS’s direct lineage from NeXTSTEP, Objective-C was the standard language used, supported, and promoted by Apple for developing macOS and iOS applications (via their respective application programming interfaces (APIs), Cocoa and Cocoa Touch) from 1997, when Apple purchased NeXT, until the introduction of the Swift language in 2014. Objective-C programs developed for non-Apple operating systems or that are not dependent on Apple's APIs may also be compiled for any platform supported by GNU GNU Compiler Collection (GCC) or LLVM/Clang. Objective-C source code 'messaging/implementation' program files usually have .m filename extensions, while Objective-C 'header/interface' files have .h extensions, the same as C header files. Objective-C++ files are denoted with a .mm filename extension. History Objective-C was created mainly by Brad Cox and Tom Love in the early 1980s at their company Productivity Products International (PPI). Leading up to the creation of their company, both had been introduced to Smalltalk while at ITT Corporation's Programming Technology Center in 1981. The earliest work on Objective-C traces back to around then. Cox was intrigued by problems of true reusability in software design and programming. He realized that a language like Smalltalk would be invaluable in building development environments for system developers at ITT. However, he and Tom Love also recognized that backward compatibility with C was critically important in ITT's telecom engineering milieu. Cox began writing a pre-processor for C to add some of the abilities of Smalltalk. He soon had a working implementation of an object-oriented extension to the C language, which he named Object-Oriented Pre-Compiler (OOPC). Love was hired by Schlumberger Research in 1982 and had the opportunity to acquire the first commercial copy of Smalltalk-80, which further influenced the development of their brainchild. To demonstrate that real progress could be made, Cox showed that making interchangeable software components really needed only a few practical changes to existing tools. Specifically, they needed to support objects in a flexible manner, come supplied with a usable set of libraries, and allow for the code (and any resources needed by the code) to be bundled into one cross-platform format. Love and Cox eventually formed PPI to commercialize their product, which coupled an Objective-C compiler with class libraries. In 1986, Cox published the main description of Objective-C in its original form in the book Object-Oriented Programming, An Evolutionary Approach. Although he was careful to explain that there is more to the problem of reusability than just what Objective-C provides, the language was often compared feature for feature with other languages. In 1988, NeXT licensed Objective-C from StepStone (the new name of PPI, the owner of the Objective-C trademark) and extended the GCC compiler to support Objective-C. NeXT developed the Application Kit (AppKit) and Foundation Kit libraries on which the NeXTSTEP user interface and Interface Builder were based. While the NeXT workstations failed to make a great impact in the marketplace, the tools were widely lauded in the industry. NeXT dropped hardware production and focused on software tools, selling NeXTSTEP (and OPENSTEP) as a platform for custom programming. To circumvent the terms of the GPL, NeXT had originally intended to ship the Objective-C frontend separately, allowing the user to link it with GCC to produce the compiler executable. Though initially accepted by Richard M. Stallman, this plan was rejected after Stallman consulted with GNU's lawyers and NeXT agreed to make Objective-C part of GCC. The work to extend GNU Compiler Collection (GCC) was led by Steve Naroff, who joined NeXT from StepStone. The compiler changes were made available as per GNU General Public License (GPL) terms, but the runtime libraries were not, rendering the open source contribution unusable to the general public. This led to other parties developing such runtime libraries under open source licenses. Later, Steve Naroff was also principal contributor to work at Apple to build the Objective-C frontend to Clang. The GNU project started work on its free software implementation of Cocoa, named GNUstep, based on the OpenStep standard. Dennis Glatting wrote the first GNU Objective-C runtime in 1992. The current GNU Objective-C runtime, in use since 1993, is the one developed by Kresten Krab Thorup while he was a university student in Denmark.[citation needed] Thorup also worked at NeXT from 1993 to 1996. After acquiring NeXT in 1996, Apple Computer used OpenStep in its then-new operating system, Mac OS X. This included Objective-C, NeXT's Objective-C-based developer tool, Project Builder, and its interface design tool, Interface Builder. Both were later merged into one application, Xcode. Most of Apple's current Cocoa API is based on OpenStep interface objects and is the most significant Objective-C environment being used for active development. At WWDC 2014, Apple introduced a new language, Swift, which was characterized as "Objective-C without the C". Syntax Objective-C is a thin layer atop C and is a "strict superset" of C, meaning that it is possible to compile any C program with an Objective-C compiler and to freely include C language code within an Objective-C class. Objective-C derives its object syntax from Smalltalk. All of the syntax for non-object-oriented operations (including primitive variables, pre-processing, expressions, function declarations, and function calls) are identical to those of C, while the syntax for object-oriented features is an implementation of Smalltalk-style messaging. The Objective-C model of object-oriented programming is based on message passing to object instances. In Objective-C, one does not call a method; one sends a message. This is unlike the Simula-style programming model used by C++. The difference between these two concepts is in how the code referenced by the method or message name is executed. In a Simula-style language, the method name is—in most cases—bound to a section of code in the target class by the compiler. In Smalltalk and Objective-C, the target of a message is resolved at runtime, with the receiving object itself interpreting the message. A method is identified by a selector or SEL — a unique identifier for each message name, often just a NUL-terminated string representing its name—and resolved to a C method pointer implementing it: an IMP. A consequence of this is that the message-passing system has no type checking. The object to which the message is directed—the receiver—is not guaranteed to respond to a message, and if it does not, it raises an exception. Sending the message method to the object pointed to by the pointer obj would require the following code in C++: In Objective-C, this is written as follows: The "method" call is translated by the compiler to the objc_msgSend(id self, SEL op, ...) family of runtime functions. Different implementations handle modern additions like super. In GNU families, this function is named objc_msg_sendv, but it has been deprecated in favor of a modern lookup system under objc_msg_lookup. Both styles of programming have multiple strengths and weaknesses. Object-oriented programming in the Simula (C++) style allows multiple inheritance and faster execution by using compile-time binding whenever possible, but it does not support dynamic binding by default. It also forces all methods to have a corresponding implementation unless they are abstract. The Smalltalk-style programming as used in Objective-C allows messages to go unimplemented, with the method resolved to its implementation at runtime. For example, a message may be sent to a collection of objects, to which only some will be expected to respond, without fear of producing runtime errors. Message passing also does not require that an object be defined at compile time. An implementation is still required for the method to be called in the derived object. (See the dynamic typing section below for more advantages of dynamic (late) binding.) Objective-C requires that the interface and implementation of a class be in separately declared code blocks. By convention, developers place the interface in a header file and the implementation in a code file. The header files, normally suffixed .h, are similar to C header files while the implementation (method) files, normally suffixed .m, can be very similar to C code files. This is analogous to class declarations as used in other object-oriented languages, such as C++ or Python. The interface of a class is usually defined in a header file. A common convention is to name the header file after the name of the class, e.g. Ball.h would contain the interface for the class Ball. An interface declaration takes the form: In the above, plus signs denote class methods, or methods that can be called on the class itself (not on an instance), and minus signs denote instance methods, which can only be called on a particular instance of the class. Class methods also have no access to instance variables. The code above is roughly equivalent to the following C++ interface: Note that instanceMethod2With2Parameters:param2_callName: demonstrates the interleaving of selector segments with argument expressions, for which there is no direct equivalent in C/C++. Return types can be any standard C type, a pointer to a generic Objective-C object, a pointer to a specific type of object such as NSArray *, NSImage *, or NSString *, or a pointer to the class to which the method belongs (instancetype). The default return type is the generic Objective-C type id. Method arguments begin with a name labeling the argument that is part of the method name, followed by a colon followed by the expected argument type in parentheses and the argument name. The label can be omitted. A derivative of the interface definition is the category, which allows one to add methods to existing classes. The interface only declares the class interface and not the methods themselves: the actual code is written in the implementation file. Implementation (method) files normally have the file extension .m, which originally signified "messages". Methods are written using their interface declarations. Comparing Objective-C and C: The syntax allows pseudo-naming of arguments. Internal representations of a method vary between different implementations of Objective-C. If myColor is of the class Color, instance method -changeColorToRed:green:blue: might be internally labeled _i_Color_changeColorToRed_green_blue. The i is to refer to an instance method, with the class and then method names appended and colons changed to underscores. As the order of parameters is part of the method name, it cannot be changed to suit coding style or expression as with true named parameters. However, internal names of the function are rarely used directly. Generally, messages are converted to function calls defined in the Objective-C runtime library. It is not necessarily known at link time which method will be called because the class of the receiver (the object being sent the message) need not be known until runtime. Once an Objective-C class is written, it can be instantiated. This is done by first allocating an uninitialized instance of the class (an object) and then by initializing it. An object is not fully functional until both steps have been completed. These steps should be accomplished with one line of code so that there is never an allocated object that hasn't undergone initialization (and because it is unwise to keep the intermediate result since -init can return a different object than that on which it is called). Instantiation with the default, no-parameter initializer: Instantiation with a custom initializer: In the case where no custom initialization is being performed, the "new" method can often be used in place of the alloc-init messages: Also, some classes implement class method initializers. Like +new, they combine +alloc and -init, but unlike +new, they return an autoreleased instance. Some class method initializers take parameters: The alloc message allocates enough memory to hold all the instance variables for an object, sets all the instance variables to zero values, and turns the memory into an instance of the class; at no point during the initialization is the memory an instance of the superclass. The init message performs the set-up of the instance upon creation. The init method is often written as follows: In the above example, notice the id return type. This type stands for pointer to any object in Objective-C (See the Dynamic typing section). The initializer pattern is used to assure that the object is properly initialized by its superclass before the init method performs its initialization. It performs the following actions: A non-valid object pointer has the value nil; conditional statements like if treat nil like a null pointer, so the initialization code will not be executed if [super init] returned nil. If there is an error in initialization, the init method should perform any necessary cleanup, including sending a release message to self, and return nil to indicate that initialization failed. Any checking for such errors must only be performed after having called the superclass initialization to ensure that destroying the object will be done correctly. If a class has more than one initialization method, only one of them (the designated initializer) needs to follow this pattern; others should call the designated initializer instead of the superclass initializer. In other programming languages, these are called interfaces. Objective-C was extended at NeXT to introduce the concept of multiple inheritance of specification, but not implementation, through the introduction of protocols. This is a pattern achievable either as an abstract multiple inherited base class in C++, or as an interface (as in Java and C#). Objective-C makes use of ad hoc protocols called informal protocols and compiler-enforced protocols called formal protocols. An informal protocol is a list of methods that a class can opt to implement. It is specified in the documentation, since it has no presence in the language. Informal protocols are implemented as a category (see below) on NSObject and often include optional methods, which, if implemented, can change the behavior of a class. For example, a text field class might have a delegate that implements an informal protocol with an optional method for performing auto-completion of user-typed text. The text field discovers whether the delegate implements that method (via reflective programming (reflection)) and, if so, calls the delegate's method to support the auto-complete feature. A formal protocol is similar to an interface in Java, C#, and Ada 2005. It is a list of methods that any class can declare itself to implement. Objective-C versions before 2.0 required that a class must implement all methods in a protocol it declares itself as adopting; the compiler will emit an error if the class does not implement every method from its declared protocols. Objective-C 2.0 added support for marking certain methods in a protocol optional, and the compiler will not enforce implementation of optional methods. A class must be declared to implement that protocol to be said to conform to it. This is detectable at runtime. Formal protocols cannot provide any implementations; they simply assure callers that classes that conform to the protocol will provide implementations. In the NeXT/Apple library, protocols are frequently used by the Distributed Objects system to represent the abilities of an object executing on a remote system. The syntax denotes that there is the abstract idea of locking. By stating in the class definition that the protocol is implemented, instances of NSLock claim that they will provide an implementation for the two instance methods. Objective-C, like Smalltalk, can use dynamic typing: an object can be sent a message that is not specified in its interface. This can allow for increased flexibility, as it allows an object to "capture" a message and send the message to a different object that can respond to the message appropriately, or likewise send the message on to another object. This behavior is known as message forwarding or delegation (see below). Alternatively, an error handler can be used in case the message cannot be forwarded. If an object does not forward a message, respond to it, or handle an error, then the system will generate a runtime exception. If messages are sent to nil (the null object pointer), they will be silently ignored or raise a generic exception, depending on compiler options. Static typing information may also optionally be added to variables. This information is then checked at compile time. In the following four statements, increasingly specific type information is provided. The statements are equivalent at runtime, but the extra information allows the compiler to warn the programmer if the passed argument does not match the type specified. In the above statement, foo may be of any class. In the above statement, foo may be an instance of any class that conforms to the NSCopying protocol. In the above statement, foo must be an instance of the NSNumber class. In the above statement, foo must be an instance of the NSNumber class, and it must conform to the NSCopying protocol. In Objective-C, all objects are represented as pointers, and static initialization is not allowed. The simplest object is the type that id (objc_obj *) points to, which only has an isa pointer describing its class. Other types from C, like values and structs, are unchanged because they are not part of the object system. This decision differs from the C++ object model, where structs and classes are united. Objective-C permits the sending of a message to an object that may not respond. Rather than responding or simply dropping the message, an object can forward the message to an object that can respond. Forwarding can be used to simplify implementation of certain design patterns, such as the observer pattern or the proxy pattern. The Objective-C runtime specifies a pair of methods in Object An object wishing to implement forwarding needs only to override the forwarding method with a new method to define the forwarding behavior. The action method performv:: need not be overridden, as this method merely performs an action based on the selector and arguments. Notice the SEL type, which is the type of messages in Objective-C. Note: in OpenStep, Cocoa, and GNUstep, the commonly used frameworks of Objective-C, one does not use the Object class. The - (void)forwardInvocation:(NSInvocation *)anInvocation method of the NSObject class is used to do forwarding. Here is an example of a program that demonstrates the basics of forwarding. When compiled using gcc, the compiler reports: The compiler is reporting the point made earlier, that Forwarder does not respond to hello messages. In this circumstance, it is safe to ignore the warning since forwarding was implemented. Running the program produces this output: During the design of Objective-C, one of the main concerns was the maintainability of large code bases. Experience from the structured programming world had shown that one of the main ways to improve code was to break it down into smaller pieces. Objective-C borrowed and extended the concept of categories[how?] from Smalltalk implementations to help with this process. Furthermore, the methods within a category are added to a class at run-time. Thus, categories permit the programmer to add methods to an existing class – an open class – without the need to recompile that class or even have access to its source code. For example, if a system does not contain a spell checker in its String implementation, it could be added without modifying the String source code. Methods within categories become indistinguishable from the methods in a class when the program is run. A category has full access to all of the instance variables within the class, including private variables. If a category declares a method with the same method signature as an existing method in a class, the category's method is adopted. Thus categories can not only add methods to a class, but also replace existing methods. This feature can be used to fix bugs in other classes by rewriting their methods, or to cause a global change to a class's behavior within a program. If two categories have methods with the same name but different method signatures, it is undefined which category's method is adopted. Other languages have attempted to add this feature in a variety of ways. TOM took the Objective-C system a step further and allowed for the addition of variables also. Other languages have used prototype-based solutions instead, the most notable being Self. The C# and Visual Basic (.NET) languages implement superficially similar function in the form of extension methods, but these lack access to the private variables of the class. Ruby and several other dynamic programming languages refer to the technique as "monkey patching". Logtalk implements a concept of categories (as first-class entities) that subsumes Objective-C categories function (Logtalk categories can also be used as fine-grained units of composition when defining e.g. new classes or prototypes; in particular, a Logtalk category can be virtually imported by any number of classes and prototypes). This example builds up an Integer class, by defining first a basic class with only accessor methods implemented, and adding two categories, Arithmetic and Display, which extend the basic class. While categories can access the base class's private data members, it is often good practice to access these private data members through the accessor methods, which helps keep categories more independent from the base class. Implementing such accessors is one typical use of categories. Another is to use categories to add methods to the base class. However, it is not regarded as good practice to use categories for subclass overriding, also known as monkey patching. Informal protocols are implemented as a category on the base NSObject class. By convention, files containing categories that extend base classes will take the name BaseClass+ExtensionClass.h. Compilation is performed, for example, by: One can experiment by leaving out the #import "Integer+Arithmetic.h" (line 2) and [num1 add:num2] (line 21) and omitting Integer+Arithmetic.m in compilation. The program will still run. This means that it is possible to mix-and-match added categories if needed; if a category does not need to have some ability, it can simply not be compiled in. Objective-C permits a class to wholly replace another class within a program. The replacing class is said to "pose as" the target class. Class posing was declared deprecated with Mac OS X v10.5, and is unavailable in the 64-bit runtime. Similar function can be achieved by using method swizzling in categories, that swaps one method's implementation with another's that have the same signature. For the versions still supporting posing, all messages sent to the target class are instead received by the posing class. There are several restrictions: Posing, similarly with categories, allows global augmentation of existing classes. Posing permits two features absent from categories: For example, This intercepts every invocation of setMainMenu to NSApplication. In the C language, the #include pre-compile directive always causes a file's contents to be inserted into the source at that point. Objective-C has the #import directive, equivalent except that each file is included only once per compilation unit, obviating the need for include guards. The Objective-C directive should not be confused with the C++ keyword import, which is used to import C++ modules (since C++20), and is not a preprocessor directive. It should also not be confused with the #import preprocessor directive in Microsoft Visual C++ (MSVC), which is non-standard and used to import type libraries. Other features Objective-C's features often allow for flexible, and often easy, solutions to programming issues. Major revisions At the 2006 Worldwide Developers Conference, Apple announced the release of "Objective-C 2.0," a revision of the Objective-C language to include "modern garbage collection, syntax enhancements, runtime performance improvements, and 64-bit support". Mac OS X v10.5, released in October 2007, included an Objective-C 2.0 compiler. GCC 4.6 supports many new Objective-C features, such as declared and synthesized properties, dot syntax, fast enumeration, optional protocol methods, method/protocol/class attributes, class extensions, and a new GNU Objective-C runtime API. The naming Objective-C 2.0 represents a break in the versioning system of the language, as the last Objective-C version for NeXT was "objc4". This project name was kept in the last release of legacy Objective-C runtime source code in Mac OS X Leopard (10.5). Objective-C 2.0 provided an optional conservative, generational garbage collector. When run in backwards-compatible mode, the runtime turned reference counting operations such as "retain" and "release" into no-ops. All objects were subject to garbage collection when garbage collection was enabled. Regular C pointers could be qualified with "__strong" to also trigger the underlying write-barrier compiler intercepts and thus participate in garbage collection. A zero-ing weak subsystem was also provided such that pointers marked as "__weak" are set to zero when the object (or more simply, GC memory) is collected. The garbage collector does not exist on the iOS implementation of Objective-C 2.0. Garbage collection in Objective-C runs on a low-priority background thread, and can halt on user events, with the intention of keeping the user experience responsive. Garbage collection was deprecated in Mac OS X v10.8 in favor of Automatic Reference Counting (ARC). Objective-C on iOS 7 running on ARM64 uses 19 bits out of a 64-bit word to store the reference count, as a form of tagged pointers. Objective-C 2.0 introduces a new syntax to declare instance variables as properties, with optional attributes to configure the generation of accessor methods. Properties are, in a sense, public instance variables; that is, declaring an instance variable as a property provides external classes with access (possibly limited, e.g. read only) to that property. A property may be declared as "readonly", and may be provided with storage semantics such as assign, copy or retain. By default, properties are considered atomic, which results in a lock preventing multiple threads from accessing them at the same time. A property can be declared as nonatomic, which removes this lock. Properties are implemented by way of the @synthesize keyword, which generates getter (and setter, if not read-only) methods according to the property declaration. Alternatively, the getter and setter methods must be implemented explicitly, or the @dynamic keyword can be used to indicate that accessor methods will be provided by other means. When compiled using clang 3.1 or higher, all properties which are not explicitly declared with @dynamic, marked readonly or have complete user-implemented getter and setter will be automatically implicitly @synthesize'd. Properties can be accessed using the traditional message passing syntax, dot notation, or, in Key-Value Coding, by name via the "valueForKey:"/"setValue:forKey:" methods. To use dot notation to invoke property accessors within an instance method, the self keyword should be used: A class or protocol's properties may be dynamically introspected. Objective-C 2.0 provides non-fragile instance variables where supported by the runtime (i.e. when building code for 64-bit macOS, and all iOS). Under the modern runtime, an extra layer of indirection is added to instance variable access, allowing the dynamic linker to adjust instance layout at runtime. This feature allows for two important improvements to Objective-C code: Instead of using an NSEnumerator object or indices to iterate through a collection, Objective-C 2.0 offers the fast enumeration syntax. In Objective-C 2.0, the following loops are functionally equivalent, but have different performance traits. Fast enumeration generates more efficient code than standard enumeration because method calls to enumerate over objects are replaced by pointer arithmetic using the NSFastEnumeration protocol. NSFastEnumeration is not present on Mac OS X version 10.4 or earlier. Binaries compiled to use this feature will not run on these earlier versions of Mac OS X. A class extension has the same syntax as a category declaration with no category name, and the methods and properties declared in it are added directly to the main class. It is mostly used as an alternative to a category to add methods to a class without advertising them in the public headers, with the advantage that for class extensions the compiler checks that all the privately declared methods are actually implemented. Blocks is an extension for Objective-C (and C and C++) that uses special syntax to create closures. Blocks are only supported in Mac OS X 10.6 "Snow Leopard" or later, iOS 4 or later, and GNUstep with libobjc2 1.7 and compiling with clang 3.1 or later. Apple has added some additional features to Objective 2.0 over time. Apple describe these changes as applying to the "Apple LLVM compiler" (clang) only, but they are also found in open-source versions of clang. Confusingly, the versioning used by Apple differs from that of the LLVM upstream; refer to Xcode § Toolchain versions for a translation to open-source LLVM version numbers. Automatic Reference Counting (ARC) is a compile-time feature that eliminates the need for programmers to manually manage retain counts using retain and release. Unlike garbage collection, which occurs at run time, ARC eliminates the overhead of a separate process managing retain counts. ARC and manual memory management are not mutually exclusive; programmers can continue to use non-ARC code in ARC-enabled projects by disabling ARC for individual code files. Xcode can also attempt to automatically upgrade a project to ARC. ARC was introduced in LLVM 3.0. This translates to Xcode 4.2 (2011), or Apple LLVM compiler 3.0. NeXT and Apple Obj-C runtimes have long included a short-form way to create new strings, using the literal syntax @"a new string", or drop to CoreFoundation constants kCFBooleanTrue and kCFBooleanFalse for NSNumber with Boolean values. Using this format saves the programmer from having to use the longer initWithString: or similar methods when doing certain operations. When using Apple LLVM compiler 4.0 (Xcode 4.4) or later, arrays, dictionaries, and numbers (NSArray, NSDictionary, NSNumber classes) can also be created using literal syntax instead of methods. (Apple LLVM compiler 4.0 translates to open source LLVM and Clang 3.1.) Example without literals: Example with literals: In Xcode versions before 13, unlike string literals, array, dictionary, and number literals were compiled into code equivalent to the above method calls. In particular, under manually reference-counted memory management, these objects were autoreleased, which required added care when, for example, used with function-static variables or other kinds of globals. In Xcode 13 (clang version 13.0.0 ) and later, array, dictionary, and number literals can also be embedded into the binary at compile time, just like string literals. This feature is enabled by default on Apple platforms and can be controlled with the -fno-objc-constant-literals and related compiler flags. When using Apple LLVM compiler 4.0 or later, arrays and dictionaries (NSArray and NSDictionary classes) can be manipulated using subscripting. Subscripting can be used to retrieve values from indexes (array) or keys (dictionary), and with mutable objects, can also be used to set objects to indexes or keys. In code, subscripting is represented using brackets [ ]. Example without subscripting: Example with subscripting: Language variants Objective-C++ is a language variant accepted by the front-end to the GNU Compiler Collection and Clang, which can compile source files that use a combination of C++ and Objective-C syntax. The term "Objective-C++" was once featured in the Apple Documentation for their Objective-C compiler as well, but has since been removed. Objective-C++ adds to C++ the extensions that Objective-C adds to C. As nothing is done to unify the semantics behind the various language features, certain restrictions apply: After the purchase of NeXT by Apple, attempts were made to make the language more acceptable to programmers more familiar with Java than Smalltalk. One of these attempts was introducing what was termed "Modern Syntax" for Objective-C at the time (in contrast to the current, "classic" syntax). There was no change in behaviour, this was merely an alternative syntax. Instead of writing a method invocation like: It was instead written as Similarly, declarations went from the form to This "modern" syntax is no longer supported in current dialects of the Objective-C language. Implementations Objective-C was originally implemented by a proprietary compiler from PPI/StepStone (see History above). NeXT instead implemented Objective-C by modifying GCC, allowing newer C features to be used. Apple maintained the situation for a while after its purchase of NeXT, giving rise to Apple GCC and Apple LLVM-GCC, both of which stopped receiving updates at version 4.2.1 due to GCC changing its license to GPLv3, which contains a provision against Tivoization.: Which runtime Apple decided to instead build on top of LLVM's clang compiler since circa 2009, which has a much more relaxed license. Apple contributes Objective-C related changes back to LLVM, making it the most complete open source implementation as of 2026. The GNU project has, for a long time, been interested in a platform to port NeXT and Obj-C programs to. The ChangeLog for the libobjc directory in GCC suggests that it existed before 1998 (GCC 2.95), and its README further points at a rewrite in 1993 (GCC 2.4). The NeXT frontend source code was released since it was made as part of GCC, released GNU General Public License which forces ones making derivative works to do so.[when?] Apple continued this tradition in releasing its fork of GCC up to 4.2.1, after which they abandoned the compiler. GCC maintainers took in the changes, but did not invest much in supporting newer features such as the Objective-C 2.0 language.: Which compiler The GNUstep developers, interested in the new language, forked the GCC libobjc to a project independent of GCC called libobjc2 in 2009. They also arranged for the runtime to be used with Clang to take advantage of the new language syntax.: Which compiler GCC moved slowly at the same time, but at GCC 4.6.0 (2011) they have moved on to Objective-C 2.0 in their libobjc as well. GNUstep documentation suggest that the GCC implementation still lacks support for blocks, non-fragile variables, and the newer ARC.: Which runtime Microsoft forked ObjFW's runtime into a part of WinObjC, the iOS bridge for Universal Windows Platform, in 2015, though switched to a fork of libobjc2 in 2016. Combined with its own implementation of Cocoa Touch and underlying APIs, the project allows the reuse of iOS Application code inside of UWP apps. On Windows, Objective-C Development tools are provided for download on GNUStep's website. The GNUStep Development System consists of the following packages: GNUstep MSYS System, GNUstep Core, GNUstep Devel, GNUstep Cairo, ProjectCenter IDE (Like Xcode, but not as complex), Gorm (Interface Builder Like Xcode NIB builder). These binary installers have not been updated since 2016, so it could be a better idea to just install by building under Cygwin or MSYS2 instead. The Clang compiler suite, part of the LLVM project, implements Objective-C and other languages. After GCC 4.3 (2008) switched to GPLv3, Apple abandoned it in favor of clang, a compiler it has more legal power to modify. As a result, many of the modern Objective-C language features are supported only by Clang. Apple's versioning scheme for its clang-based "LLVM compiler" differs from the LLVM's open-source versioning. See Xcode § Toolchain versions for a translation. The mulle-objc is a performance-oriented implementation of Objective-C. It uses a runtime library written in pure C11, which ensures portability (among other platforms, it supports Linux, FreeBSD, and Windows). The runtime library can be statically linked with musl. It uses a fork of clang/LLVM as the compiler and a fork of gdb as the debugger. Mulle-objc has an intentionally reduced feature set, best described as "Objective-C 1.0 with some cherry-picked 2.0 features". The Protable Object Compiler was an alternative implementation of Objective-C. The set of extensions implemented by the Portable Object Compiler differs from the GCC/NeXT/Apple implementation; in particular, it includes Smalltalk-like blocks for Objective-C, while it lacks protocols and categories, two features used extensively in OpenStep and its derivatives and relatives. Overall, POC represents an older, pre-NeXT stage in the language's evolution, roughly conformant to Brad Cox's 1991 book. It also includes a runtime library called ObjectPak, which is based on Cox's original ICPak101 library (which in turn derives from the Smalltalk-80 class library), and is quite radically different from the OpenStep FoundationKit. Library use Objective-C today is often used in tandem with a fixed library of standard objects (often known as a "kit" or "framework"), such as Cocoa, GNUstep or ObjFW. These libraries often come with the operating system: the GNUstep libraries often come with Linux-based distributions and Cocoa comes with macOS. The programmer is not forced to inherit functions from the existing base class (NSObject – OFObject). Objective-C allows for the declaration of new root classes that do not inherit any existing function. Originally, Objective-C-based programming environments typically offered an Object class as the base class from which almost all other classes inherited. With the introduction of OpenStep, NeXT created a new base class named NSObject, which offered additional features over Object (an emphasis on using object references and reference counting instead of raw pointers, for example). Almost all classes in Cocoa inherit from NSObject. Not only did the renaming serve to differentiate the new default behavior of classes within the OpenStep API, but it allowed code that used Object—the original base class used on NeXTSTEP (and, more or less, other Objective-C class libraries)—to co-exist in the same runtime with code that used NSObject (with some limitations). The introduction of the two letter prefix also became a simplistic form of namespaces, which Objective-C lacks. Using a prefix to create an informal packaging identifier became an informal coding standard in the Objective-C community, and continues to this day. More recently, package managers have started appearing, such as CocoaPods, which aims to be both a package manager and a repository of packages. A lot of open-source Objective-C code that was written in the last few years can now be installed using CocoaPods. Analysis of the language Objective-C implementations use a thin runtime system written in C[citation needed], which adds little to the size of the application. In contrast, most object-oriented systems at the time that it was created used large virtual machine runtimes. Programs written in Objective-C tend to be not much larger than the size of their code and that of the libraries (which generally do not need to be included in the software distribution), in contrast to Smalltalk systems where a large amount of memory was used just to open a window. Objective-C applications tend to be larger than similar C or C++ applications because Objective-C dynamic typing does not allow methods to be stripped or inlined. Since the programmer has such freedom to delegate, forward calls, build selectors on the fly, and pass them to the runtime system, the Objective-C compiler cannot assume it is safe to remove unused methods or to inline calls. Likewise, the language can be implemented atop extant C compilers (in GCC, first as a preprocessor, then as a module) rather than as a new compiler. This allows Objective-C to leverage the huge existing collection of C code, libraries, tools, etc. Existing C libraries can be wrapped in Objective-C wrappers to provide an OO-style interface. In this aspect, it is similar to GObject library and Vala language, which are widely used in development of GTK applications. All of these practical changes lowered the barrier to entry, likely the biggest problem for the widespread acceptance of Smalltalk in the 1980s. A common criticism is that Objective-C does not have language support for namespaces. Instead, programmers are forced to add prefixes to their class names, which are traditionally shorter than namespace names and thus more prone to collisions. As of 2007, all macOS classes and functions in the Cocoa programming environment are prefixed with "NS" (e.g. NSObject, NSButton) to identify them as belonging to the macOS or iOS core; the "NS" derives from the names of the classes as defined during the development of NeXTSTEP. Since Objective-C is a strict superset of C, it does not treat C primitive types as first-class objects. Unlike C++, Objective-C does not support operator overloading. Also unlike C++, Objective-C allows an object to directly inherit from only one class (forbidding multiple inheritance). However, in most cases, categories and protocols may be used as alternative ways to achieve the same results. Because Objective-C uses dynamic runtime typing and because all method calls are function calls (or, in some cases, syscalls), many common performance optimizations cannot be applied to Objective-C methods (for example: inlining, constant propagation, interprocedural optimizations, and scalar replacement of aggregates). This limits the performance of Objective-C abstractions relative to similar abstractions in languages such as C++ where such optimizations are possible. The first versions of Objective-C did not support garbage collection. At the time this decision was a matter of some debate, and many people considered long "dead times" (when Smalltalk performed collection) to render the entire system unusable. Some 3rd party implementations have added this feature (most notably GNUstep using Boehm), and Apple has implemented it as of Mac OS X v10.5. However, in more recent versions of macOS and iOS, garbage collection has been deprecated in favor of Automatic Reference Counting (ARC), introduced in 2011. With ARC, the compiler inserts retain and release calls automatically into Objective-C code based on static code analysis. The automation relieves the programmer of having to write in memory management code. ARC also adds weak references to the Objective-C language. The design and implementation of C++ and Objective-C represent fundamentally different approaches to extending C. In addition to C's style of procedural programming, C++ directly supports certain forms of object-oriented programming, generic programming, and metaprogramming. C++ also comes with a large standard library that includes several container classes. Similarly, Objective-C adds object-oriented programming, dynamic typing, and reflection to C. Objective-C does not provide a standard library per se, but in most places where Objective-C is used, it is used with an OpenStep-like library such as OPENSTEP, Cocoa, or GNUstep, which provides functions similar to C++'s standard library. One notable difference is that Objective-C provides runtime support for reflective programming features, whereas C++ adds only a small amount of runtime support to C. In Objective-C, an object can be queried about its own properties, e.g., whether it will respond to a certain message. In C++, this is not possible without the use of external libraries. The use of reflection is part of the wider distinction between dynamic (run-time) features and static (compile-time) features of a language. Although Objective-C and C++ each employ a mix of both features, Objective-C favors run-time decisions while C++ favors compile-time decisions. The tension between dynamic and static programming involves many of the classic trade-offs in programming: dynamic features add flexibility, static features add speed and type checking. Generic programming and metaprogramming can be implemented in both languages using runtime polymorphism (dynamic dispatch). In C++, this takes the form of virtual functions and runtime type identification, while Objective-C offers dynamic typing and reflection. Both Objective-C and C++ support compile-time polymorphism (generic functions), with Objective-C adding this feature in 2015. Similarly-named languages The PC GEOS system used a programming language known as GEOS Objective-C or goc; despite the name similarity, the two languages are similar only in overall concept and the use of keywords prefixed with an @ sign. See also References Further reading 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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Contents Minecraft Minecraft is a sandbox game developed and published by Mojang Studios. Following its initial public alpha release in 2009, it was formally released in 2011 for personal computers. The game has since been ported to numerous platforms, including mobile devices and various video game consoles. In Minecraft, players explore a procedurally generated world with virtually infinite terrain made up of voxels (cubes). They can discover and extract raw materials, craft tools and items, build structures, fight hostile mobs, and cooperate with or compete against other players in multiplayer. The game's large community offers a wide variety of user-generated content, such as modifications, servers, player skins, texture packs, and custom maps, which add new game mechanics and possibilities. Originally created by Markus "Notch" Persson using the Java programming language, Jens "Jeb" Bergensten was handed control over the game's development following its full release. In 2014, Mojang and the Minecraft intellectual property were purchased by Microsoft for US$2.5 billion; Xbox Game Studios hold the publishing rights for the Bedrock Edition, the unified cross-platform version which evolved from the Pocket Edition codebase[i] and replaced the legacy console versions. Bedrock is updated concurrently with Mojang's original Java Edition, although with numerous, generally small, differences. Minecraft is the best-selling video game in history with over 350 million copies sold. It has received critical acclaim, winning several awards and being cited as one of the greatest video games of all time. Social media, parodies, adaptations, merchandise, and the annual Minecon conventions have played prominent roles in popularizing it. The wider Minecraft franchise includes several spin-off games, such as Minecraft: Story Mode, Minecraft Dungeons, and Minecraft Legends. A film adaptation, titled A Minecraft Movie, was released in 2025 and became the second highest-grossing video game film of all time. Gameplay Minecraft is a 3D sandbox video game that has no required goals to accomplish, giving players a large amount of freedom in choosing how to play the game. The game features an optional achievement system. Gameplay is in the first-person perspective by default, but players have the option of third-person perspectives. The game world is composed of rough 3D objects—mainly cubes, referred to as blocks—representing various materials, such as dirt, stone, ores, tree trunks, water, and lava. The core gameplay revolves around picking up and placing these objects. These blocks are arranged in a voxel grid, while players can move freely around the world. Players can break, or mine, blocks and then place them elsewhere, enabling them to build things. Very few blocks are affected by gravity, instead maintaining their voxel position in the air. Players can also craft a wide variety of items, such as armor, which mitigates damage from attacks; weapons (such as swords or bows and arrows), which allow monsters and animals to be killed more easily; and tools (such as pickaxes or shovels), which break certain types of blocks more quickly. Some items have multiple tiers depending on the material used to craft them, with higher-tier items being more effective and durable. They may also freely craft helpful blocks—such as furnaces which can cook food and smelt ores, and torches that produce light—or exchange items with villagers (NPC) through trading emeralds for different goods and vice versa. The game has an inventory system, allowing players to carry a limited number of items. The in-game time system follows a day and night cycle, with one full cycle lasting for 20 real-time minutes. The game also contains a material called redstone, which can be used to make primitive mechanical devices, electrical circuits, and logic gates, allowing for the construction of many complex systems. New players are given a randomly selected default character skin out of nine possibilities, including Steve or Alex, but are able to create and upload their own skins. Players encounter various mobs (short for mobile entities) including animals, villagers, and hostile creatures. Passive mobs, such as cows, pigs, and chickens, spawn during the daytime and can be hunted for food and crafting materials, while hostile mobs—including large spiders, witches, skeletons, and zombies—spawn during nighttime or in dark places such as caves. Some hostile mobs, such as zombies and skeletons, burn under the sun if they have no headgear and are not standing in water. Other creatures unique to Minecraft include the creeper (an exploding creature that sneaks up on the player) and the enderman (a creature with the ability to teleport as well as pick up and place blocks). There are also variants of mobs that spawn in different conditions; for example, zombies have husk and drowned variants that spawn in deserts and oceans, respectively. The Minecraft environment is procedurally generated as players explore it using a map seed that is randomly chosen at the time of world creation (or manually specified by the player). Divided into biomes representing different environments with unique resources and structures, worlds are designed to be effectively infinite in traditional gameplay, though technical limits on the player have existed throughout development, both intentionally and not. Implementation of horizontally infinite generation initially resulted in a glitch termed the "Far Lands" at over 12 million blocks away from the world center, where terrain generated as wall-like, fissured patterns. The Far Lands and associated glitches were considered the effective edge of the world until they were resolved, with the current horizontal limit instead being a special impassable barrier called the world border, located 30 million blocks away. Vertical space is comparatively limited, with an unbreakable bedrock layer at the bottom and a building limit several hundred blocks into the sky. Minecraft features three independent dimensions accessible through portals and providing alternate game environments. The Overworld is the starting dimension and represents the real world, with a terrestrial surface setting including plains, mountains, forests, oceans, caves, and small sources of lava. The Nether is a hell-like underworld dimension accessed via an obsidian portal and composed mainly of lava. Mobs that populate the Nether include shrieking, fireball-shooting ghasts, alongside anthropomorphic pigs called piglins and their zombified counterparts. Piglins in particular have a bartering system, where players can give them gold ingots and receive items in return. Structures known as Nether Fortresses generate in the Nether, containing mobs such as wither skeletons and blazes, which can drop blaze rods needed to access the End dimension. The player can also choose to build an optional boss mob known as the Wither, using skulls obtained from wither skeletons and soul sand. The End can be reached through an end portal, consisting of twelve end portal frames. End portals are found in underground structures in the Overworld known as strongholds. To find strongholds, players must craft eyes of ender using an ender pearl and blaze powder. Eyes of ender can then be thrown, traveling in the direction of the stronghold. Once the player reaches the stronghold, they can place eyes of ender into each portal frame to activate the end portal. The dimension consists of islands floating in a dark, bottomless void. A boss enemy called the Ender Dragon guards the largest, central island. Killing the dragon opens access to an exit portal, which, when entered, cues the game's ending credits and the End Poem, a roughly 1,500-word work written by Irish novelist Julian Gough, which takes about nine minutes to scroll past, is the game's only narrative text, and the only text of significant length directed at the player.: 10–12 At the conclusion of the credits, the player is teleported back to their respawn point and may continue the game indefinitely. In Survival mode, players have to gather natural resources such as wood and stone found in the environment in order to craft certain blocks and items. Depending on the difficulty, monsters spawn in darker areas outside a certain radius of the character, requiring players to build a shelter in order to survive at night. The mode also has a health bar which is depleted by attacks from mobs, falls, drowning, falling into lava, suffocation, starvation, and other events. Players also have a hunger bar, which must be periodically refilled by eating food in-game unless the player is playing on peaceful difficulty. If the hunger bar is empty, the player starves. Health replenishes when players have a full hunger bar or continuously on peaceful. Upon losing all health, players die. The items in the players' inventories are dropped unless the game is reconfigured not to do so. Players then re-spawn at their spawn point, which by default is where players first spawn in the game and can be changed by sleeping in a bed or using a respawn anchor. Dropped items can be recovered if players can reach them before they despawn after 5 minutes. Players may acquire experience points (commonly referred to as "xp" or "exp") by killing mobs and other players, mining, smelting ores, animal breeding, and cooking food. Experience can then be spent on enchanting tools, armor and weapons. Enchanted items are generally more powerful, last longer, or have other special effects. The game features two more game modes based on Survival, known as Hardcore mode and Adventure mode. Hardcore mode plays identically to Survival mode, but with the game's difficulty setting locked to "Hard" and with permadeath, forcing them to delete the world or explore it as a spectator after dying. Adventure mode was added to the game in a post-launch update, and prevents the player from directly modifying the game's world. It was designed primarily for use in custom maps, allowing map designers to let players experience it as intended. In Creative mode, players have access to an infinite number of all resources and items in the game through the inventory menu and can place or mine them instantly. Players can toggle the ability to fly freely around the game world at will, and their characters usually do not take any damage nor are affected by hunger. The game mode helps players focus on building and creating projects of any size without disturbance. Multiplayer in Minecraft enables multiple players to interact and communicate with each other on a single world. It is available through direct game-to-game multiplayer, local area network (LAN) play, local split screen (console-only), and servers (player-hosted and business-hosted). Players can run their own server by making a realm, using a host provider, hosting one themselves or connect directly to another player's game via Xbox Live, PlayStation Network or Nintendo Switch Online. Single-player worlds have LAN support, allowing players to join a world on locally interconnected computers without a server setup. Minecraft multiplayer servers are guided by server operators, who have access to server commands such as setting the time of day and teleporting players. Operators can also set up restrictions concerning which usernames or IP addresses are allowed or disallowed to enter the server. Multiplayer servers have a wide range of activities, with some servers having their own unique rules and customs. The largest and most popular server is Hypixel, which has been visited by over 14 million unique players. Player versus player combat (PvP) can be enabled to allow fighting between players. In 2013, Mojang announced Minecraft Realms, a server hosting service intended to enable players to run server multiplayer games easily and safely without having to set up their own. Unlike a standard server, only invited players can join Realms servers, and these servers do not use server addresses. Minecraft: Java Edition Realms server owners can invite up to twenty people to play on their server, with up to ten players online at a time. Minecraft Realms server owners can invite up to 3,000 people to play on their server, with up to ten players online at one time. The Minecraft: Java Edition Realms servers do not support user-made plugins, but players can play custom Minecraft maps. Minecraft Bedrock Realms servers support user-made add-ons, resource packs, behavior packs, and custom Minecraft maps. At Electronic Entertainment Expo 2016, support for cross-platform play between Windows 10, iOS, and Android platforms was added through Realms starting in June 2016, with Xbox One and Nintendo Switch support to come later in 2017, and support for virtual reality devices. On 31 July 2017, Mojang released the beta version of the update allowing cross-platform play. Nintendo Switch support for Realms was released in July 2018. The modding community consists of fans, users and third-party programmers. Using a variety of application program interfaces that have arisen over time, they have produced a wide variety of downloadable content for Minecraft, such as modifications, texture packs and custom maps. Modifications of the Minecraft code, called mods, add a variety of gameplay changes, ranging from new blocks, items, and mobs to entire arrays of mechanisms. The modding community is responsible for a substantial supply of mods from ones that enhance gameplay, such as mini-maps, waypoints, and durability counters, to ones that add to the game elements from other video games and media. While a variety of mod frameworks were independently developed by reverse engineering the code, Mojang has also enhanced vanilla Minecraft with official frameworks for modification, allowing the production of community-created resource packs, which alter certain game elements including textures and sounds. Players can also create their own "maps" (custom world save files) that often contain specific rules, challenges, puzzles and quests, and share them for others to play. Mojang added an adventure mode in August 2012 and "command blocks" in October 2012, which were created specially for custom maps in Java Edition. Data packs, introduced in version 1.13 of the Java Edition, allow further customization, including the ability to add new achievements, dimensions, functions, loot tables, predicates, recipes, structures, tags, and world generation. The Xbox 360 Edition supported downloadable content, which was available to purchase via the Xbox Games Store; these content packs usually contained additional character skins. It later received support for texture packs in its twelfth title update while introducing "mash-up packs", which combined texture packs with skin packs and changes to the game's sounds, music and user interface. The first mash-up pack (and by extension, the first texture pack) for the Xbox 360 Edition was released on 4 September 2013, and was themed after the Mass Effect franchise. Unlike Java Edition, however, the Xbox 360 Edition did not support player-made mods or custom maps. A cross-promotional resource pack based on the Super Mario franchise by Nintendo was released exclusively for the Wii U Edition worldwide on 17 May 2016, and later bundled free with the Nintendo Switch Edition at launch. Another based on Fallout was released on consoles that December, and for Windows and Mobile in April 2017. In April 2018, malware was discovered in several downloadable user-made Minecraft skins for use with the Java Edition of the game. Avast stated that nearly 50,000 accounts were infected, and when activated, the malware would attempt to reformat the user's hard drive. Mojang promptly patched the issue, and released a statement stating that "the code would not be run or read by the game itself", and would run only when the image containing the skin itself was opened. In June 2017, Mojang released the "1.1 Discovery Update" to the Pocket Edition of the game, which later became the Bedrock Edition. The update introduced the "Marketplace", a catalogue of purchasable user-generated content intended to give Minecraft creators "another way to make a living from the game". Various skins, maps, texture packs and add-ons from different creators can be bought with "Minecoins", a digital currency that is purchased with real money. Additionally, users can access specific content with a subscription service titled "Marketplace Pass". Alongside content from independent creators, the Marketplace also houses items published by Mojang and Microsoft themselves, as well as official collaborations between Minecraft and other intellectual properties. By 2022, the Marketplace had over 1.7 billion content downloads, generating over $500 million in revenue. Development Before creating Minecraft, Markus "Notch" Persson was a game developer at King, where he worked until March 2009. At King, he primarily developed browser games and learned several programming languages. During his free time, he prototyped his own games, often drawing inspiration from other titles, and was an active participant on the TIGSource forums for independent developers. One such project was "RubyDung", a base-building game inspired by Dwarf Fortress, but with an isometric, three-dimensional perspective similar to RollerCoaster Tycoon. Among the features in RubyDung that he explored was a first-person view similar to Dungeon Keeper, though he ultimately discarded this idea, feeling the graphics were too pixelated at the time. Around March 2009, Persson left King and joined jAlbum, while continuing to work on his prototypes. Infiniminer, a block-based open-ended mining game first released in April 2009, inspired Persson's vision for RubyDung's future direction. Infiniminer heavily influenced the visual style of gameplay, including bringing back the first-person mode, the "blocky" visual style and the block-building fundamentals. However, unlike Infiniminer, Persson wanted Minecraft to have RPG elements. The first public alpha build of Minecraft was released on 17 May 2009 on TIGSource. Over the years, Persson regularly released test builds that added new features, including tools, mobs, and entire new dimensions. In 2011, partly due to the game's rising popularity, Persson decided to release a full 1.0 version—a second part of the "Adventure Update"—on 18 November 2011. Shortly after, Persson stepped down from development, handing the project's lead to Jens "Jeb" Bergensten. On 15 September 2014, Microsoft, the developer behind the Microsoft Windows operating system and Xbox video game console, announced a $2.5 billion acquisition of Mojang, which included the Minecraft intellectual property. Persson had suggested the deal on Twitter, asking a corporation to buy his stake in the game after receiving criticism for enforcing terms in the game's end-user license agreement (EULA), which had been in place for the past three years. According to Persson, Mojang CEO Carl Manneh received a call from a Microsoft executive shortly after the tweet, asking if Persson was serious about a deal. Mojang was also approached by other companies including Activision Blizzard and Electronic Arts. The deal with Microsoft was arbitrated on 6 November 2014 and led to Persson becoming one of Forbes' "World's Billionaires". After 2014, Minecraft's primary versions received usually annual major updates—free to players who have purchased the game— each primarily centered around a specific theme. For instance, version 1.13, the Update Aquatic, focused on ocean-related features, while version 1.16, the Nether Update, introduced significant changes to the Nether dimension. However, in late 2024, Mojang announced a shift in their update strategy; rather than releasing large updates annually, they opted for a more frequent release schedule with smaller, incremental updates, stating, "We know that you want new Minecraft content more often." The Bedrock Edition has also received regular updates, now matching the themes of the Java Edition updates. Other versions of the game, such as various console editions and the Pocket Edition, were either merged into Bedrock or discontinued and have not received further updates. On 7 May 2019, coinciding with Minecraft's 10th anniversary, a JavaScript recreation of an old 2009 Java Edition build named Minecraft Classic was made available to play online for free. On 16 April 2020, a Bedrock Edition-exclusive beta version of Minecraft, called Minecraft RTX, was released by Nvidia. It introduced physically-based rendering, real-time path tracing, and DLSS for RTX-enabled GPUs. The public release was made available on 8 December 2020. Path tracing can only be enabled in supported worlds, which can be downloaded for free via the in-game Minecraft Marketplace, with a texture pack from Nvidia's website, or with compatible third-party texture packs. It cannot be enabled by default with any texture pack on any world. Initially, Minecraft RTX was affected by many bugs, display errors, and instability issues. On 22 March 2025, a new visual mode called Vibrant Visuals, an optional graphical overhaul similar to Minecraft RTX, was announced. It promises modern rendering features—such as dynamic shadows, screen space reflections, volumetric fog, and bloom—without the need of RTX-capable hardware. Vibrant Visuals was released as a part of the Chase the Skies update on 17 June 2025 for Bedrock Edition and is planned to release on Java Edition at a later date. Development began for the original edition of Minecraft—then known as Cave Game, and now known as the Java Edition—in May 2009,[k] and ended on 13 May, when Persson released a test video on YouTube of an early version of the game, dubbed the "Cave game tech test" or the "Cave game tech demo". The game was named Minecraft: Order of the Stone the next day, after a suggestion made by a player. "Order of the Stone" came from the webcomic The Order of the Stick, and "Minecraft" was chosen "because it's a good name". The title was later shortened to just Minecraft, omitting the subtitle. Persson completed the game's base programming over a weekend in May 2009, and private testing began on TigIRC on 16 May. The first public release followed on 17 May 2009 as a developmental version shared on the TIGSource forums. Based on feedback from forum users, Persson continued updating the game. This initial public build later became known as Classic. Further developmental phases—dubbed Survival Test, Indev, and Infdev—were released throughout 2009 and 2010. The first major update, known as Alpha, was released on 30 June 2010. At the time, Persson was still working a day job at jAlbum but later resigned to focus on Minecraft full-time as sales of the alpha version surged. Updates were distributed automatically, introducing new blocks, items, mobs, and changes to game mechanics such as water flow. With revenue generated from the game, Persson founded Mojang, a video game studio, alongside former colleagues Jakob Porser and Carl Manneh. On 11 December 2010, Persson announced that Minecraft would enter its beta phase on 20 December. He assured players that bug fixes and all pre-release updates would remain free. As development progressed, Mojang expanded, hiring additional employees to work on the project. The game officially exited beta and launched in full on 18 November 2011. On 1 December 2011, Jens "Jeb" Bergensten took full creative control over Minecraft, replacing Persson as lead designer. On 28 February 2012, Mojang announced the hiring of the developers behind Bukkit, a popular developer API for Minecraft servers, to improve Minecraft's support of server modifications. This move included Mojang taking apparent ownership of the CraftBukkit server mod, though this apparent acquisition later became controversial, and its legitimacy was questioned due to CraftBukkit's open-source nature and licensing under the GNU General Public License and Lesser General Public License. In August 2011, Minecraft: Pocket Edition was released as an early alpha for the Xperia Play via the Android Market, later expanding to other Android devices on 8 October 2011. The iOS version followed on 17 November 2011. A port was made available for Windows Phones shortly after Microsoft acquired Mojang. Unlike Java Edition, Pocket Edition initially focused on Minecraft's creative building and basic survival elements but lacked many features of the PC version. Bergensten confirmed on Twitter that the Pocket Edition was written in C++ rather than Java, as iOS does not support Java. On 10 December 2014, a port of Pocket Edition was released for Windows Phone 8.1. In July 2015, a port of the Pocket Edition to Windows 10 was released as the Windows 10 Edition, with full crossplay to other Pocket versions. In January 2017, Microsoft announced that it would no longer maintain the Windows Phone versions of Pocket Edition. On 20 September 2017, with the "Better Together Update", the Pocket Edition was ported to the Xbox One, and was renamed to the Bedrock Edition. The console versions of Minecraft debuted with the Xbox 360 edition, developed by 4J Studios and released on 9 May 2012. Announced as part of the Xbox Live Arcade NEXT promotion, this version introduced a redesigned crafting system, a new control interface, in-game tutorials, split-screen multiplayer, and online play via Xbox Live. Unlike the PC version, its worlds were finite, bordered by invisible walls. Initially, the Xbox 360 version resembled outdated PC versions but received updates to bring it closer to Java Edition before eventually being discontinued. The Xbox One version launched on 5 September 2014, featuring larger worlds and support for more players. Minecraft expanded to PlayStation platforms with PlayStation 3 and PlayStation 4 editions released on 17 December 2013 and 4 September 2014, respectively. Originally planned as a PS4 launch title, it was delayed before its eventual release. A PlayStation Vita version followed in October 2014. Like the Xbox versions, the PlayStation editions were developed by 4J Studios. Nintendo platforms received Minecraft: Wii U Edition on 17 December 2015, with a physical release in North America on 17 June 2016 and in Europe on 30 June. The Nintendo Switch version launched via the eShop on 11 May 2017. During a Nintendo Direct presentation on 13 September 2017, Nintendo announced that Minecraft: New Nintendo 3DS Edition, based on the Pocket Edition, would be available for download immediately after the livestream, and a physical copy available on a later date. The game is compatible only with the New Nintendo 3DS or New Nintendo 2DS XL systems and does not work with the original 3DS or 2DS systems. On 20 September 2017, the Better Together Update introduced Bedrock Edition across Xbox One, Windows 10, VR, and mobile platforms, enabling cross-play between these versions. Bedrock Edition later expanded to Nintendo Switch and PlayStation 4, with the latter receiving the update in December 2019, allowing cross-platform play for users with a free Xbox Live account. The Bedrock Edition released a native version for PlayStation 5 on 22 October 2024, while the Xbox Series X/S version launched on 17 June 2025. On 18 December 2018, the PlayStation 3, PlayStation Vita, Xbox 360, and Wii U versions of Minecraft received their final update and would later become known as "Legacy Console Editions". On 15 January 2019, the New Nintendo 3DS version of Minecraft received its final update, effectively becoming discontinued as well. An educational version of Minecraft, designed for use in schools, launched on 1 November 2016. It is available on Android, ChromeOS, iPadOS, iOS, MacOS, and Windows. On 20 August 2018, Mojang announced that it would bring Education Edition to iPadOS in Autumn 2018. It was released to the App Store on 6 September 2018. On 27 March 2019, it was announced that it would be operated by JD.com in China. On 26 June 2020, a public beta for the Education Edition was made available to Google Play Store compatible Chromebooks. The full game was released to the Google Play Store for Chromebooks on 7 August 2020. On 20 May 2016, China Edition (also known as My World) was announced as a localized edition for China, where it was released under a licensing agreement between NetEase and Mojang. The PC edition was released for public testing on 8 August 2017. The iOS version was released on 15 September 2017, and the Android version was released on 12 October 2017. The PC edition is based on the original Java Edition, while the iOS and Android mobile versions are based on the Bedrock Edition. The edition is free-to-play and had over 700 million registered accounts by September 2023. This version of Bedrock Edition is exclusive to Microsoft's Windows 10 and Windows 11 operating systems. The beta release for Windows 10 launched on the Windows Store on 29 July 2015. After nearly a year and a half in beta, Microsoft fully released the version on 19 December 2016. Called the "Ender Update", this release implemented new features to this version of Minecraft like world templates and add-on packs. On 7 June 2022, the Java and Bedrock Editions of Minecraft were merged into a single bundle for purchase on Windows; those who owned one version would automatically gain access to the other version. Both game versions would otherwise remain separate. Around 2011, prior to Minecraft's full release, Mojang collaborated with The Lego Group to create a Lego brick-based Minecraft game called Brickcraft. This would have modified the base Minecraft game to use Lego bricks, which meant adapting the basic 1×1 block to account for larger pieces typically used in Lego sets. Persson worked on an early version called "Project Rex Kwon Do", named after the character of the same name from the film Napoleon Dynamite. Although Lego approved the project and Mojang assigned two developers for six months, it was canceled due to the Lego Group's demands, according to Mojang's Daniel Kaplan. Lego considered buying Mojang to complete the game, but when Microsoft offered over $2 billion for the company, Lego stepped back, unsure of Minecraft's potential. On 26 June 2025, a build of Brickcraft dated 28 June 2012 was published on a community archive website Omniarchive. Initially, Markus Persson planned to support the Oculus Rift with a Minecraft port. However, after Facebook acquired Oculus in 2013, he abruptly canceled the plans, stating, "Facebook creeps me out." In 2016, a community-made mod, Minecraft VR, added VR support for Java Edition, followed by Vivecraft for HTC Vive. Later that year, Microsoft introduced official Oculus Rift support for Windows 10 Edition, leading to the discontinuation of the Minecraft VR mod due to trademark complaints. Vivecraft was endorsed by Minecraft VR contributors for its Rift support. Also available is a Gear VR version, titled Minecraft: Gear VR Edition. Windows Mixed Reality support was added in 2017. On 7 September 2020, Mojang Studios announced that the PlayStation 4 Bedrock version would receive PlayStation VR support later that month. In September 2024, the Minecraft team announced they would no longer support PlayStation VR, which received its final update in March 2025. Music and sound design Minecraft's music and sound effects were produced by German musician Daniel Rosenfeld, better known as C418. To create the sound effects for the game, Rosenfeld made extensive use of Foley techniques. On learning the processes for the game, he remarked, "Foley's an interesting thing, and I had to learn its subtleties. Early on, I wasn't that knowledgeable about it. It's a whole trial-and-error process. You just make a sound and eventually you go, 'Oh my God, that's it! Get the microphone!' There's no set way of doing anything at all." He reminisced on creating the in-game sound for grass blocks, stating "It turns out that to make grass sounds you don't actually walk on grass and record it, because grass sounds like nothing. What you want to do is get a VHS, break it apart, and just lightly touch the tape." According to Rosenfeld, his favorite sound to design for the game was the hisses of spiders. He elaborates, "I like the spiders. Recording that was a whole day of me researching what a spider sounds like. Turns out, there are spiders that make little screeching sounds, so I think I got this recording of a fire hose, put it in a sampler, and just pitched it around until it sounded like a weird spider was talking to you." Many of the sound design decisions by Rosenfeld were done accidentally or spontaneously. The creeper notably lacks any specific noises apart from a loud fuse-like sound when about to explode; Rosenfeld later recalled "That was just a complete accident by Markus and me [sic]. We just put in a placeholder sound of burning a matchstick. It seemed to work hilariously well, so we kept it." On other sounds, such as those of the zombie, Rosenfeld remarked, "I actually never wanted the zombies so scary. I intentionally made them sound comical. It's nice to hear that they work so well [...]." Rosenfeld remarked that the sound engine was "terrible" to work with, remembering "If you had two song files at once, it [the game engine] would actually crash. There were so many more weird glitches like that the guys never really fixed because they were too busy with the actual game and not the sound engine." The background music in Minecraft consists of instrumental ambient music. To compose the music of Minecraft, Rosenfeld used the package from Ableton Live, along with several additional plug-ins. Speaking on them, Rosenfeld said "They can be pretty much everything from an effect to an entire orchestra. Additionally, I've got some synthesizers that are attached to the computer. Like a Moog Voyager, Dave Smith Prophet 08 and a Virus TI." On 4 March 2011, Rosenfeld released a soundtrack titled Minecraft – Volume Alpha; it includes most of the tracks featured in Minecraft, as well as other music not featured in the game. Kirk Hamilton of Kotaku chose the music in Minecraft as one of the best video game soundtracks of 2011. On 9 November 2013, Rosenfeld released the second official soundtrack, titled Minecraft – Volume Beta, which included the music that was added in a 2013 "Music Update" for the game. A physical release of Volume Alpha, consisting of CDs, black vinyl, and limited-edition transparent green vinyl LPs, was issued by indie electronic label Ghostly International on 21 August 2015. On 14 August 2020, Ghostly released Volume Beta on CD and vinyl, with alternate color LPs and lenticular cover pressings released in limited quantities. The final update Rosenfeld worked on was 2018's 1.13 Update Aquatic. His music remained the only music in the game until 2020's "Nether Update", introducing pieces from Lena Raine. Since then, other composers have made contributions, including Kumi Tanioka, Samuel Åberg, Aaron Cherof, and Amos Roddy, with Raine remaining as the new primary composer. Ownership of all music besides Rosenfeld's independently released albums has been retained by Microsoft, with their label publishing all of the other artists' releases. Gareth Coker also composed some of the music for the game's mini games from the Legacy Console editions. Rosenfeld had stated his intent to create a third album of music for the game in a 2015 interview with Fact, and confirmed its existence in a 2017 tweet, stating that his work on the record as of then had tallied up to be longer than the previous two albums combined, which in total clocks in at over 3 hours and 18 minutes. However, due to licensing issues with Microsoft, the third volume has since not seen release. On 8 January 2021, Rosenfeld was asked in an interview with Anthony Fantano whether or not there was still a third volume of his music intended for release. Rosenfeld responded, saying, "I have something—I consider it finished—but things have become complicated, especially as Minecraft is now a big property, so I don't know." Reception Minecraft has received critical acclaim, with praise for the creative freedom it grants players in-game, as well as the ease of enabling emergent gameplay. Critics have expressed enjoyment in Minecraft's complex crafting system, commenting that it is an important aspect of the game's open-ended gameplay. Most publications were impressed by the game's "blocky" graphics, with IGN describing them as "instantly memorable". Reviewers also liked the game's adventure elements, noting that the game creates a good balance between exploring and building. The game's multiplayer feature has been generally received favorably, with IGN commenting that "adventuring is always better with friends". Jaz McDougall of PC Gamer said Minecraft is "intuitively interesting and contagiously fun, with an unparalleled scope for creativity and memorable experiences". It has been regarded as having introduced millions of children to the digital world, insofar as its basic game mechanics are logically analogous to computer commands. IGN was disappointed about the troublesome steps needed to set up multiplayer servers, calling it a "hassle". Critics also said that visual glitches occur periodically. Despite its release out of beta in 2011, GameSpot said the game had an "unfinished feel", adding that some game elements seem "incomplete or thrown together in haste". A review of the alpha version, by Scott Munro of the Daily Record, called it "already something special" and urged readers to buy it. Jim Rossignol of Rock Paper Shotgun also recommended the alpha of the game, calling it "a kind of generative 8-bit Lego Stalker". On 17 September 2010, gaming webcomic Penny Arcade began a series of comics and news posts about the addictiveness of the game. The Xbox 360 version was generally received positively by critics, but did not receive as much praise as the PC version. Although reviewers were disappointed by the lack of features such as mod support and content from the PC version, they acclaimed the port's addition of a tutorial and in-game tips and crafting recipes, saying that they make the game more user-friendly. The Xbox One Edition was one of the best received ports, being praised for its relatively large worlds. The PlayStation 3 Edition also received generally favorable reviews, being compared to the Xbox 360 Edition and praised for its well-adapted controls. The PlayStation 4 edition was the best received port to date, being praised for having 36 times larger worlds than the PlayStation 3 edition and described as nearly identical to the Xbox One edition. The PlayStation Vita Edition received generally positive reviews from critics but was noted for its technical limitations. The Wii U version received generally positive reviews from critics but was noted for a lack of GamePad integration. The 3DS version received mixed reviews, being criticized for its high price, technical issues, and lack of cross-platform play. The Nintendo Switch Edition received fairly positive reviews from critics, being praised, like other modern ports, for its relatively larger worlds. Minecraft: Pocket Edition initially received mixed reviews from critics. Although reviewers appreciated the game's intuitive controls, they were disappointed by the lack of content. The inability to collect resources and craft items, as well as the limited types of blocks and lack of hostile mobs, were especially criticized. After updates added more content, Pocket Edition started receiving more positive reviews. Reviewers complimented the controls and the graphics, but still noted a lack of content. Minecraft surpassed over a million purchases less than a month after entering its beta phase in early 2011. At the same time, the game had no publisher backing and has never been commercially advertised except through word of mouth, and various unpaid references in popular media such as the Penny Arcade webcomic. By April 2011, Persson estimated that Minecraft had made €23 million (US$33 million) in revenue, with 800,000 sales of the alpha version of the game, and over 1 million sales of the beta version. In November 2011, prior to the game's full release, Minecraft beta surpassed 16 million registered users and 4 million purchases. By March 2012, Minecraft had become the 6th best-selling PC game of all time. As of 10 October 2014[update], the game had sold 17 million copies on PC, becoming the best-selling PC game of all time. On 25 February 2014, the game reached 100 million registered users. By May 2019, 180 million copies had been sold across all platforms, making it the single best-selling video game of all time. The free-to-play Minecraft China version had over 700 million registered accounts by September 2023. By 2023, the game had sold over 300 million copies. As of April 2025, Minecraft has sold over 350 million copies. The Xbox 360 version of Minecraft became profitable within the first day of the game's release in 2012, when the game broke the Xbox Live sales records with 400,000 players online. Within a week of being on the Xbox Live Marketplace, Minecraft sold a million copies. GameSpot announced in December 2012 that Minecraft sold over 4.48 million copies since the game debuted on Xbox Live Arcade in May 2012. In 2012, Minecraft was the most purchased title on Xbox Live Arcade; it was also the fourth most played title on Xbox Live based on average unique users per day. As of 4 April 2014[update], the Xbox 360 version has sold 12 million copies. In addition, Minecraft: Pocket Edition has reached a figure of 21 million in sales. The PlayStation 3 Edition sold one million copies in five weeks. The release of the game's PlayStation Vita version boosted Minecraft sales by 79%, outselling both PS3 and PS4 debut releases and becoming the largest Minecraft launch on a PlayStation console. The PS Vita version sold 100,000 digital copies in Japan within the first two months of release, according to an announcement by SCE Japan Asia. By January 2015, 500,000 digital copies of Minecraft were sold in Japan across all PlayStation platforms, with a surge in primary school children purchasing the PS Vita version. As of 2022, the Vita version has sold over 1.65 million physical copies in Japan, making it the best-selling Vita game in the country. Minecraft helped improve Microsoft's total first-party revenue by $63 million for the 2015 second quarter. The game, including all of its versions, had over 112 million monthly active players by September 2019. On its 11th anniversary in May 2020, the company announced that Minecraft had reached over 200 million copies sold across platforms with over 126 million monthly active players. By April 2021, the number of active monthly users had climbed to 140 million. In July 2010, PC Gamer listed Minecraft as the fourth-best game to play at work. In December of that year, Good Game selected Minecraft as their choice for Best Downloadable Game of 2010, Gamasutra named it the eighth best game of the year as well as the eighth best indie game of the year, and Rock, Paper, Shotgun named it the "game of the year". Indie DB awarded the game the 2010 Indie of the Year award as chosen by voters, in addition to two out of five Editor's Choice awards for Most Innovative and Best Singleplayer Indie. It was also awarded Game of the Year by PC Gamer UK. The game was nominated for the Seumas McNally Grand Prize, Technical Excellence, and Excellence in Design awards at the March 2011 Independent Games Festival and won the Grand Prize and the community-voted Audience Award. At Game Developers Choice Awards 2011, Minecraft won awards in the categories for Best Debut Game, Best Downloadable Game and Innovation Award, winning every award for which it was nominated. It also won GameCity's video game arts award. On 5 May 2011, Minecraft was selected as one of the 80 games that would be displayed at the Smithsonian American Art Museum as part of The Art of Video Games exhibit that opened on 16 March 2012. At the 2011 Spike Video Game Awards, Minecraft won the award for Best Independent Game and was nominated in the Best PC Game category. In 2012, at the British Academy Video Games Awards, Minecraft was nominated in the GAME Award of 2011 category and Persson received The Special Award. In 2012, Minecraft XBLA was awarded a Golden Joystick Award in the Best Downloadable Game category, and a TIGA Games Industry Award in the Best Arcade Game category. In 2013, it was nominated as the family game of the year at the British Academy Video Games Awards. During the 16th Annual D.I.C.E. Awards, the Academy of Interactive Arts & Sciences nominated the Xbox 360 version of Minecraft for "Strategy/Simulation Game of the Year". Minecraft Console Edition won the award for TIGA Game Of The Year in 2014. In 2015, the game placed 6th on USgamer's The 15 Best Games Since 2000 list. In 2016, Minecraft placed 6th on Time's The 50 Best Video Games of All Time list. Minecraft was nominated for the 2013 Kids' Choice Awards for Favorite App, but lost to Temple Run. It was nominated for the 2014 Kids' Choice Awards for Favorite Video Game, but lost to Just Dance 2014. The game later won the award for the Most Addicting Game at the 2015 Kids' Choice Awards. In addition, the Java Edition was nominated for "Favorite Video Game" at the 2018 Kids' Choice Awards, while the game itself won the "Still Playing" award at the 2019 Golden Joystick Awards, as well as the "Favorite Video Game" award at the 2020 Kids' Choice Awards. Minecraft also won "Stream Game of the Year" at inaugural Streamer Awards in 2021. The game later garnered a Nickelodeon Kids' Choice Award nomination for Favorite Video Game in 2021, and won the same category in 2022 and 2023. At the Golden Joystick Awards 2025, it won the Still Playing Award - PC and Console. Minecraft has been subject to several notable controversies. In June 2014, Mojang announced that it would begin enforcing the portion of Minecraft's end-user license agreement (EULA) which prohibits servers from giving in-game advantages to players in exchange for donations or payments. Spokesperson Owen Hill stated that servers could still require players to pay a fee to access the server and could sell in-game cosmetic items. The change was supported by Persson, citing emails he received from parents of children who had spent hundreds of dollars on servers. The Minecraft community and server owners protested, arguing that the EULA's terms were more broad than Mojang was claiming, that the crackdown would force smaller servers to shut down for financial reasons, and that Mojang was suppressing competition for its own Minecraft Realms subscription service. The controversy contributed to Notch's decision to sell Mojang. In 2020, Mojang announced an eventual change to the Java Edition to require a login from a Microsoft account rather than a Mojang account, the latter of which would be sunsetted. This also required Java Edition players to create Xbox network Gamertags. Mojang defended the move to Microsoft accounts by saying that improved security could be offered, including two-factor authentication, blocking cyberbullies in chat, and improved parental controls. The community responded with intense backlash, citing various technical difficulties encountered in the process and how account migration would be mandatory, even for those who do not play on servers. As of 10 March 2022, Microsoft required that all players migrate in order to maintain access the Java Edition of Minecraft. Mojang announced a deadline of 19 September 2023 for account migration, after which all legacy Mojang accounts became inaccessible and unable to be migrated. In June 2022, Mojang added a player-reporting feature in Java Edition. Players could report other players on multiplayer servers for sending messages prohibited by the Xbox Live Code of Conduct; report categories included profane language,[l] substance abuse, hate speech, threats of violence, and nudity. If a player was found to be in violation of Xbox Community Standards, they would be banned from all servers for a specific period of time or permanently. The update containing the report feature (1.19.1) was released on 27 July 2022. Mojang received substantial backlash and protest from community members, one of the most common complaints being that banned players would be forbidden from joining any server, even private ones. Others took issue to what they saw as Microsoft increasing control over its player base and exercising censorship, leading some to start a hashtag #saveminecraft and dub the version "1.19.84", a reference to the dystopian novel Nineteen Eighty-Four. The "Mob Vote" was an online event organized by Mojang in which the Minecraft community voted between three original mob concepts; initially, the winning mob was to be implemented in a future update, while the losing mobs were scrapped, though after the first mob vote this was changed, and losing mobs would now have a chance to come to the game in the future. The first Mob Vote was held during Minecon Earth 2017 and became an annual event starting with Minecraft Live 2020. The Mob Vote was often criticized for forcing players to choose one mob instead of implementing all three, causing divisions and flaming within the community, and potentially allowing internet bots and Minecraft content creators with large fanbases to conduct vote brigading. The Mob Vote was also blamed for a perceived lack of new content added to Minecraft since Microsoft's acquisition of Mojang in 2014. The 2023 Mob Vote featured three passive mobs—the crab, the penguin, and the armadillo—with voting scheduled to start on 13 October. In response, a Change.org petition was created on 6 October, demanding that Mojang eliminate the Mob Vote and instead implement all three mobs going forward. The petition received approximately 445,000 signatures by 13 October and was joined by calls to boycott the Mob Vote, as well as a partially tongue-in-cheek "revolutionary" propaganda campaign in which sympathizers created anti-Mojang and pro-boycott posters in the vein of real 20th century propaganda posters. Mojang did not release an official response to the boycott, and the Mob Vote otherwise proceeded normally, with the armadillo winning the vote. In September 2024, as part of a blog post detailing their future plans for Minecraft's development, Mojang announced the Mob Vote would be retired. Cultural impact In September 2019, The Guardian classified Minecraft as the best video game of the 21st century to date, and in November 2019, Polygon called it the "most important game of the decade" in its 2010s "decade in review". In June 2020, Minecraft was inducted into the World Video Game Hall of Fame. Minecraft is recognized as one of the first successful games to use an early access model to draw in sales prior to its full release version to help fund development. As Minecraft helped to bolster indie game development in the early 2010s, it also helped to popularize the use of the early access model in indie game development. Social media sites such as YouTube, Facebook, and Reddit have played a significant role in popularizing Minecraft. Research conducted by the Annenberg School for Communication at the University of Pennsylvania showed that one-third of Minecraft players learned about the game via Internet videos. In 2010, Minecraft-related videos began to gain influence on YouTube, often made by commentators. The videos usually contain screen-capture footage of the game and voice-overs. Common coverage in the videos includes creations made by players, walkthroughs of various tasks, and parodies of works in popular culture. By May 2012, over four million Minecraft-related YouTube videos had been uploaded. The game would go on to be a prominent fixture within YouTube's gaming scene during the entire 2010s; in 2014, it was the second-most searched term on the entire platform. By 2018, it was still YouTube's biggest game globally. Some popular commentators have received employment at Machinima, a now-defunct gaming video company that owned a highly watched entertainment channel on YouTube. The Yogscast is a British company that regularly produces Minecraft videos; their YouTube channel has attained billions of views, and their panel at Minecon 2011 had the highest attendance. Another well-known YouTube personality is Jordan Maron, known online as CaptainSparklez, who has also created many Minecraft music parodies, including "Revenge", a parody of Usher's "DJ Got Us Fallin' in Love". Minecraft's popularity on YouTube was described by Polygon as quietly dominant, although in 2019, thanks in part to PewDiePie's playthroughs of the game, Minecraft experienced a visible uptick in popularity on the platform. Longer-running series include Far Lands or Bust, dedicated to reaching the obsolete "Far Lands" glitch by foot on an older version of the game. YouTube announced that on 14 December 2021 that the total amount of Minecraft-related views on the website had exceeded one trillion. Minecraft has been referenced by other video games, such as Torchlight II, Team Fortress 2, Borderlands 2, Choplifter HD, Super Meat Boy, The Elder Scrolls V: Skyrim, The Binding of Isaac, The Stanley Parable, and FTL: Faster Than Light. Minecraft is officially represented in downloadable content for the crossover fighter Super Smash Bros. Ultimate, with Steve as a playable character with a moveset including references to building, crafting, and redstone, alongside an Overworld-themed stage. It was also referenced by electronic music artist Deadmau5 in his performances. The game is also referenced heavily in "Informative Murder Porn", the second episode of the seventeenth season of the animated television series South Park. In 2025, A Minecraft Movie was released. It made $313 million in the box office in the first week, a record-breaking opening for a video game adaptation. Minecraft has been noted as a cultural touchstone for Generation Z, as many of the generation's members played the game at a young age. The possible applications of Minecraft have been discussed extensively, especially in the fields of computer-aided design (CAD) and education. In a panel at Minecon 2011, a Swedish developer discussed the possibility of using the game to redesign public buildings and parks, stating that rendering using Minecraft was much more user-friendly for the community, making it easier to envision the functionality of new buildings and parks. In 2012, a member of the Human Dynamics group at the MIT Media Lab, Cody Sumter, said: "Notch hasn't just built a game. He's tricked 40 million people into learning to use a CAD program." Various software has been developed to allow virtual designs to be printed using professional 3D printers or personal printers such as MakerBot and RepRap. In September 2012, Mojang began the Block by Block project in cooperation with UN Habitat to create real-world environments in Minecraft. The project allows young people who live in those environments to participate in designing the changes they would like to see. Using Minecraft, the community has helped reconstruct the areas of concern, and citizens are invited to enter the Minecraft servers and modify their own neighborhood. Carl Manneh, Mojang's managing director, called the game "the perfect tool to facilitate this process", adding "The three-year partnership will support UN-Habitat's Sustainable Urban Development Network to upgrade 300 public spaces by 2016." Mojang signed Minecraft building community, FyreUK, to help render the environments into Minecraft. The first pilot project began in Kibera, one of Nairobi's informal settlements and is in the planning phase. The Block by Block project is based on an earlier initiative started in October 2011, Mina Kvarter (My Block), which gave young people in Swedish communities a tool to visualize how they wanted to change their part of town. According to Manneh, the project was a helpful way to visualize urban planning ideas without necessarily having a training in architecture. The ideas presented by the citizens were a template for political decisions. In April 2014, the Danish Geodata Agency generated all of Denmark in fullscale in Minecraft based on their own geodata. This is possible because Denmark is one of the flattest countries with the highest point at 171 meters (ranking as the country with the 30th smallest elevation span), where the limit in default Minecraft was around 192 meters above in-game sea level when the project was completed. Taking advantage of the game's accessibility where other websites are censored, the non-governmental organization Reporters Without Borders has used an open Minecraft server to create the Uncensored Library, a repository within the game of journalism by authors from countries (including Egypt, Mexico, Russia, Saudi Arabia and Vietnam) who have been censored and arrested, such as Jamal Khashoggi. The neoclassical virtual building was created over about 250 hours by an international team of 24 people. Despite its unpredictable nature, Minecraft speedrunning, where players time themselves from spawning into a new world to reaching The End and defeating the Ender Dragon boss, is popular. Some speedrunners use a combination of mods, external programs, and debug menus, while other runners play the game in a more vanilla or more consistency-oriented way. Minecraft has been used in educational settings through initiatives such as MinecraftEdu, founded in 2011 to make the game affordable and accessible for schools in collaboration with Mojang. MinecraftEdu provided features allowing teachers to monitor student progress, including screenshot submissions as evidence of lesson completion, and by 2012 reported that approximately 250,000 students worldwide had access to the platform. Mojang also developed Minecraft: Education Edition with pre-built lesson plans for up to 30 students in a closed environment. Educators have used Minecraft to teach subjects such as history, language arts, and science through custom-built environments, including reconstructions of historical landmarks and large-scale models of biological structures such as animal cells. The introduction of redstone blocks enabled the construction of functional virtual machines such as a hard drive and an 8-bit computer. Mods have been created to use these mechanics for teaching programming. In 2014, the British Museum announced a project to reproduce its building and exhibits in Minecraft in collaboration with the public. Microsoft and Code.org have offered Minecraft-based tutorials and activities designed to teach programming, reporting by 2018 that more than 85 million children had used their resources. In 2025, the Musée de Minéralogie in Paris held a temporary exhibition titled "Minerals in Minecraft." Following the initial surge in popularity of Minecraft in 2010, other video games were criticised for having various similarities to Minecraft, and some were described as being "clones", often due to a direct inspiration from Minecraft, or a superficial similarity. Examples include Ace of Spades, CastleMiner, CraftWorld, FortressCraft, Terraria, BlockWorld 3D, Total Miner, and Luanti (formerly Minetest). David Frampton, designer of The Blockheads, reported that one failure of his 2D game was the "low resolution pixel art" that too closely resembled the art in Minecraft, which resulted in "some resistance" from fans. A homebrew adaptation of the alpha version of Minecraft for the Nintendo DS, titled DScraft, has been released; it has been noted for its similarity to the original game considering the technical limitations of the system. In response to Microsoft's acquisition of Mojang and their Minecraft IP, various developers announced further clone titles developed specifically for Nintendo's consoles, as they were the only major platforms not to officially receive Minecraft at the time. These clone titles include UCraft (Nexis Games), Cube Life: Island Survival (Cypronia), Discovery (Noowanda), Battleminer (Wobbly Tooth Games), Cube Creator 3D (Big John Games), and Stone Shire (Finger Gun Games). Despite this, the fears of fans were unfounded, with official Minecraft releases on Nintendo consoles eventually resuming. Markus Persson made another similar game, Minicraft, for a Ludum Dare competition in 2011. In 2025, Persson announced through a poll on his X account that he was considering developing a spiritual successor to Minecraft. He later clarified that he was "100% serious", and that he had "basically announced Minecraft 2". Within days, however, Persson cancelled the plans after speaking to his team. In November 2024, artificial intelligence companies Decart and Etched released Oasis, an artificially generated version of Minecraft, as a proof of concept. Every in-game element is completely AI-generated in real time and the model does not store world data, leading to "hallucinations" such as items and blocks appearing that were not there before. In January 2026, indie game developer Unomelon announced that their voxel sandbox game Allumeria would be playable in Steam Next Fest that year. On 10 February, Mojang issued a DMCA takedown of Allumeria on Steam through Valve, alleging the game was infringing on Minecraft's copyright. Some reports suggested that the takedown may have used an automatic AI copyright claiming service. The DMCA was later withdrawn. Minecon was an annual official fan convention dedicated to Minecraft. The first full Minecon was held in November 2011 at the Mandalay Bay Hotel and Casino in Las Vegas. The event included the official launch of Minecraft; keynote speeches, including one by Persson; building and costume contests; Minecraft-themed breakout classes; exhibits by leading gaming and Minecraft-related companies; commemorative merchandise; and autograph and picture times with Mojang employees and well-known contributors from the Minecraft community. In 2016, Minecon was held in-person for the last time, with the following years featuring annual "Minecon Earth" livestreams on minecraft.net and YouTube instead. These livestreams, later rebranded to "Minecraft Live", included the mob/biome votes, and announcements of new game updates. In 2025, "Minecraft Live" became a biannual event as part of Minecraft's changing update schedule.[citation needed] Notes References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Royal_Radar_Establishment] | [TOKENS: 1692] |
Contents Royal Radar Establishment The Royal Radar Establishment was a research centre in Malvern, Worcestershire in the United Kingdom. It was formed in 1953 as the Radar Research Establishment by the merger of the Air Ministry's Telecommunications Research Establishment (TRE) and the British Army's Radar Research and Development Establishment (RRDE). It was given its new name after a visit by Queen Elizabeth II in 1957. Both names were abbreviated to RRE. In 1976 the Signals Research and Development Establishment (SRDE), involved in communications research, joined the RRE to form the Royal Signals and Radar Establishment (RSRE). The two groups had been closely associated since before the opening of World War II, when the predecessor to RRDE was formed as a small group within the Air Ministry's research centre in Bawdsey Manor in Suffolk. Forced to leave Bawdsey due to its exposed location on the east coast of England, both groups moved several times before finally settling in separate locations in Malvern beginning in May 1942. The merger in 1953 that formed the RRE renamed these as the North Site (RRDE) and South Site (TRE). The earlier research and development work of TRE and RRDE on radar was expanded into solid state physics, electronics, and computer hardware and software. The RRE's overall scope was extended to include cryogenics and other topics. Infrared detection for guided missiles and heat sensing devices was a major defence application. The SRDE brought satellite communications and fibre optics knowledge. In 1991 they were partially privatized as part of the Defence Research Agency, which became the Defence Evaluation and Research Agency in 1996. The North Site was closed in 2003 and the work was consolidated at the South Site, while the former North Site was sold off for housing developments. Qinetiq now occupies a part of the former RSRE site. Administrative history The earliest concerted effort to develop radar in the UK dates to 1935, and Robert Watt replied to an Air Ministry question about radio-based death rays by stating they were impossible, but using radio as a detection means was possible. After a simple practical demonstration, a prototype system was built at Orfordness on the east coast of England. While on a Sunday drive in the area, Watt noticed the large and unused Bawdsey Manor, and this was leased by the Air Ministry to become first radar research centre in the country. Soon after taking over Bawdsey in 1936, the British Army heard of their efforts and formed a group to work with them to develop ground-based applications. The first project of this "Army Cell" was a ranging system for anti-aircraft artillery, but they soon added the Coast Defence radars and began work on the proximity fuse. At the outbreak of the war in 1939, the location of Bawdsey, right on the east coast, was considered far too exposed to attack. The Air Ministry team quickly moved to Dundee in Scotland, where the former Air Ministry Experimental Station became the Air Ministry Research Establishment (AMRE). The Army group moved to Christchurch, outside Bournemouth, becoming the Air Defence Experimental Establishment (ADEE). The facilities in Dundee proved far too small and isolated, and in May 1940 they moved again, this time to Worth Matravers on the south coast of England, also a short distance from Bournemouth. This was accompanied by yet another renaming, now becoming the Telecommunications Research Establishment (TRE). Ultimately they began to worry that this location was also too exposed, and when they heard a German paratroop unit had moved to France directly across the English Channel, they decided to move once again. The ADEE, by this time once again renamed to the Air Defence Research and Development (ADRDE), moved to underutilized Air Ministry buildings on the north side of Malvern in May 1942. This, of course, resulted in yet another name change to the RRDE. The TRE followed shortly thereafter, taking up residence in buildings across from Malvern College on the south side of town. TRE was part of the Ministry of Supply and, when it was formed, so was RRE. In 1959, control passed to the Ministry of Aviation. When this was abolished in 1967, control passed to the Ministry of Technology, then to the Ministry of Aviation Supply, in 1970, and to the Ministry of Defence in 1971. In 1976 RRE merged with the Signals Research and Development Establishment (SRDE) to form the Royal Signals and Radar Establishment (RSRE), which became part of the Defence Research Agency (DRA) in 1991. Later (1995), DRA was absorbed into DERA, the Defence Evaluation and Research Agency. DERA split on 2 June 2001 into two parts, a government body called Dstl (Defence Science and Technology Laboratory) and a company destined for privatisation, which became QinetiQ. The technical departments of RRE were grouped, initially, into six Divisions: airborne radar, ground radar, guided weapons, basic techniques, physics, and engineering. The organization and personnel are described further, in a collection of linked web sites. W. J. Richards, CBE, was Director of TRE at the time of the merger and continued as Director of RRE. William Henry (Bill) Penley, Head of Guided Missiles, took over for a year in 1961. Then George Macfarlane (after postings outside RRE) became Director in 1962. The Physics Division – some of the staff and their work At the time of the name change to Radar Research Establishment in 1953, the senior staff included: Other members of the Physics Division who made significant contributions to several fields of endeavour include: In 1956, R.A. Smith presented a comprehensive account of the contributions of RRE to physics to the Royal Society. Radar, Guided weapons and Engineering Divisions Although less conspicuous among academic scientists, these divisions were major players in the defence community, both in policy decision making and as an interface with industry. Development and production contracts brought staff of several companies on site, and extramural contracts strengthened ties with industry still further. "in radar alone: Plessey and Decca for aerials and waveguides, Plessey, Hilger & Watts, Clarke Chapman and Curran for millimetre-wave radar, and Mullard for precision bombing and radar reconnaissance". On returning to RRE as Director in 1962, George Macfarlane reorganized the technical departments into: Military and Civil Systems (comprising Ground Radar and Air Traffic Control, Guided Weapons and Airborne Radar groups), Physics and Electronics (comprising Physics and Electronic Groups) and Engineering. "Despite the policy shift away from fighters ... to guided weapons for UK air defence, ... RRE continued to argue for strike aircraft and kept up the necessary radar research programs." In December 1968, the report on the programming language ALGOL 68 was published. On 20–24 July 1970, a working conference was arranged by the International Federation for Information Processing (IFIP) to discuss the problems of implementing the language. A small team from RRE attended to present their compiler, written by I. F. Currie, Susan G. Bond, and J. D. Morrison. ALGOL 68 was complex: implementing it was estimated to need up to 100 man-years, using multi-pass compilers with up to seven passes. The RRE team described how they had already implemented a one-pass compiler, which was already in production for engineering and scientific uses. It was the first working version of ALGOL 68. Senior staff, of the divisions at various times included More than 50 books were written by members of the establishment under its successive names. Details are included in the list of references below, and in the TRE article. Many more were in series that members of the staff edited. In 1968, the Minister of Supply assured a member of parliament that the results of research at RRE on infra-red detectors would be made available to British industry. A former member of the RRE, Martin Woodhouse, later became better known as a novelist. Locations References External links |
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[SOURCE: https://en.wikipedia.org/wiki/Meta_Platforms#cite_note-zuck_ownership-8] | [TOKENS: 8626] |
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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