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Tony Fairall
Anthony Patrick (Tony) Fairall (September 15, 1943 – November 22, 2008) was a South African astronomer most noted for his work on exploring the large-scale structure of the Universe, such as filaments and voids. He was the director of what is now the Iziko planetarium in Cape Town and was a well-known popularizer of astronomy in South Africa. Fairall was born in London and moved with his family to Johannesburg, South Africa, in 1948 and then Harare, Zimbabwe in 1953. He studied at the University of Cape Town, completing his undergraduate degree in 1966. He studied for his doctorate under Gerard de Vaucouleurs and Fritz Zwicky at the University of Texas at Austin The University of Texas at Austin (UT Austin, UT, or Texas) is a public university, public research university in Austin, Texas, United States. Founded in 1883, it is the flagship institution of the University of Texas System. With 53,082 stud ..., receiving his degree in 1970. Fairall discovered and named Fai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South African People
According to the 2022 census, the population of South Africa is about 62 million people of diverse origins, cultures, Languages of South Africa, languages, and Religion in South Africa, religions, with a majority being Black Africans. The South African National Census of 2022 was the most recent census held; the next will be in 2032. In 2011, Statistics South Africa counted 2.1 million foreigners in total. Reports suggest that is an underestimation. The real figure may be as high as five million, including some three million Demographics of Zimbabwe, Zimbabweans. History The earliest creatures that can be identified as human ancestors in South Africa are Australopithecine, australopithecines. The first evidence of this was a Taung Child, child's skull found in the Taung quarry site. This was in the modern day North West (South African province), North-West province. More Fossil, fossils australopithecines were found in limestone caves Sterkfontein, Swartkrans, and Kromdraai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galaxies – in either observational astronomy, observational (by analyzing the data) or theoretical astronomy. Examples of topics or fields astronomers study include planetary science, Sun, solar astronomy, the Star formation, origin or stellar evolution, evolution of stars, or the galaxy formation and evolution, formation of galaxies. A related but distinct subject is physical cosmology, which studies the Universe as a whole. Types Astronomers typically fall under either of two main types: observational astronomy, observational and theoretical astronomy, theoretical. Observational astronomers make direct observations of Astronomical object, celestial objects and analyze the data. In contrast, theoretical astronomers create and investigate Con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large-scale Structure Of The Universe
The observable universe is a spherical region of the universe consisting of all matter that can be observed from Earth; the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. Assuming the universe is isotropic, the distance to the edge of the observable universe is the same in every direction. That is, the observable universe is a spherical region centered on the observer. Every location in the universe has its own observable universe, which may or may not overlap with the one centered on Earth. The word ''observable'' in this sense does not refer to the capability of modern technology to detect light or other information from an object, or whether there is anything to be detected. It refers to the physical limit created by the speed of light itself. No signal can travel faster than light, hence there is a maximum distance, called the particle horizon, beyond which nothing can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Filament
In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of galactic superclusters. These massive, thread-like formations can commonly reach 50 to 80 megaparsecs ()—with the largest found to date being the Hercules-Corona Borealis Great Wall at around in length—and form the boundaries between voids. Due to the accelerating expansion of the universe, the individual clusters of gravitationally bound galaxies that make up galaxy filaments are moving away from each other at an accelerated rate; in the far future they will dissolve. Galaxy filaments form the cosmic web and define the overall structure of the observable universe. Discovery Discovery of structures larger than superclusters began in the late 1980s. In 1987, astronomer R. Brent Tully of the University of Hawaii's Institute of Astronomy identified what he called the Pisces–Cetus Supercluster Complex. The CfA2 Great Wall was discovered in 1989, followed by the Sloa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Void (astronomy)
Cosmic voids (also known as dark space) are vast spaces between Galaxy filament, filaments (the largest-scale structures in the universe), which contain void galaxy, very few or no Galaxy, galaxies. In spite of their size, most galaxies are not located in voids. This is because most galaxies are gravitationally bound together, creating huge cosmic structures known as galaxy filaments. The cosmological evolution of the void regions differs drastically from the evolution of the universe as a whole: there is a long stage when Shape_of_the_universe#Curvature_of_the_universe, the curvature term dominates, which prevents the formation of galaxy clusters and massive galaxies. Hence, although even the emptiest regions of voids contain more than ~15% of the average matter density of the universe, the voids look almost empty to an observer. Voids typically have a diameter of 10 to 100 Parsec#Megaparsecs and gigaparsecs, megaparsecs (30 to 300 million light-years); particularly large void ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iziko South African Museum
The Iziko South African Museum, formerly the South African Museum (Afrikaans: Suid-Afrikaanse Museum), is a South African national museum located in Cape Town. The museum was founded in 1825, the first in the country. It has been on its present site in the Company's Garden since 1897. The museum houses important African zoology, palaeontology, and archaeology collections. In 2012, the South African Museum was renamed to its present name. It is governed by the national museums' governing body, Iziko Museums of South Africa. ''Iziko'' is a Xhosa language, Xhosa word meaning "hearth". History The South African Museum was founded in 1825 by Lord Charles Somerset (1767-1831), who was Governor of the Cape Colony from 1814 to 1826. The museum has been on its present site in the Company's Garden since 1897. It began as a general museum comprising natural history and material culture from local and other groups further afield. In time, it developed greater systematic organisation and cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cape Town
The University of Cape Town (UCT) (, ) is a public university, public research university in Cape Town, South Africa. Established in 1829 as the South African College, it was granted full university status in 1918, making it the oldest university in South Africa and the List of oldest universities in continuous operation, oldest university in Sub-Saharan Africa in continuous operation. UCT is organised in 57 departments across six faculties offering Bachelor's degree, bachelor's (Education in South Africa#Higher education and training system, NQF 7) to Doctorate, doctoral degrees (Education in South Africa#Higher education and training system, NQF 10) solely in the English language. Home to 30,000 students, it encompasses six campuses in the Capetonian suburbs of Rondebosch, Hiddingh, Observatory, Cape Town, Observatory, Mowbray, Cape Town, Mowbray, and the Waterfront. It is the only African member of the Global University Leaders Forum (GULF) within the World Economic Forum, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gerard De Vaucouleurs
Gerard is a masculine forename of Proto-Germanic origin, variations of which exist in many Germanic and Romance languages. Like many other early Germanic names, it is dithematic, consisting of two meaningful constituents put together. In this case, those constituents are ''gari'' > ''ger-'' (meaning 'spear') and -''hard'' (meaning 'hard/strong/brave'). Common forms of the name are Gerard (English, Scottish, Irish, Dutch, Polish and Catalan); Gerrard (English, Scottish, Irish); (Italian, and Spanish); ( Portuguese); (Italian); (Northern Italian, now only a surname); (variant forms and , now only surnames, French); ( Irish); Gerhardt and Gerhart/Gerhard/Gerhardus (German, Dutch, and Afrikaans); ( Hungarian); ( Lithuanian) and / ( Latvian); (Greece). A few abbreviated forms are Gerry and Jerry (English); (German) and (Afrikaans and Dutch); (Afrikaans and Dutch); (Afrikaans); (Dutch) and ( Bulgarian). The introduction of the name 'Gerard' into the English languag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fritz Zwicky
Fritz Zwicky (; ; February 14, 1898 – February 8, 1974) was a Swiss astronomer. He worked most of his life at the California Institute of Technology in the United States of America, where he made many important contributions in theoretical and observational astronomy. In 1933, Zwicky was the first to use the virial theorem to postulate the existence of unseen dark matter, describing it as "'". From p 125: ''"Um, wie beobachtet, einen mittleren Dopplereffekt von 1000 km/sek oder mehr zu erhalten, müsste also die mittlere Dichte im Comasystem mindestens 400 mal grösser sein als die auf Grund von Beobachtungen an leuchtender Materie abgeleitete. Falls sich dies bewahrheiten sollte, würde sich also das überraschende Resultat ergeben, dass dunkle Materie in sehr viel grösserer Dichte vorhanden ist als leuchtende Materie."'' (In order to obtain an average Doppler effect of 1000 km/s or more, as observed, the average density in the Coma system would thus have to be at least 40 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Texas At Austin
The University of Texas at Austin (UT Austin, UT, or Texas) is a public university, public research university in Austin, Texas, United States. Founded in 1883, it is the flagship institution of the University of Texas System. With 53,082 students as of fall 2023, it is also the largest institution in the system. The university is a major center for academic research, with research expenditures totaling $1.06 billion for the 2023 fiscal year. It joined the Association of American Universities in 1929. The university houses seven museums and seventeen libraries, including the Lyndon Baines Johnson Library and Museum, Lyndon B. Johnson Presidential Library and the Blanton Museum of Art, and operates various auxiliary research facilities, such as the J. J. Pickle Research Campus and McDonald Observatory. UT Austin's athletics constitute the Texas Longhorns. The Longhorns have won four NCAA Division I National Football Championships, six NCAA Division I National Baseball Champions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminosity
Luminosity is an absolute measure of radiated electromagnetic radiation, electromagnetic energy per unit time, and is synonymous with the radiant power emitted by a light-emitting object. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a star, galaxy, or other astronomical object, astronomical objects. In SI units, luminosity is measured in joules per second, or watts. In astronomy, values for luminosity are often given in the terms of the Solar luminosity, luminosity of the Sun, ''L''⊙. Luminosity can also be given in terms of the astronomical Magnitude (astronomy), magnitude system: the Absolute magnitude#Bolometric magnitude, absolute bolometric magnitude (''M''bol) of an object is a logarithmic measure of its total energy emission rate, while absolute magnitude is a logarithmic measure of the luminosity within some specific wavelength range or Passband, filter band. In contrast, the term ''brightness'' in astronomy is gene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seyfert Galaxy
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasar host galaxies. They have quasar-like nuclei (very luminous sources of electromagnetic radiation that are outside of our own galaxy) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable. Seyfert galaxies account for about 10% of all galaxies and are some of the most intensely studied objects in astronomy, as they are thought to be powered by the same phenomena that occur in quasars, although they are closer and less luminous than quasars. These galaxies have supermassive black holes at their centers which are surrounded by accretion discs of in-falling material. The accretion discs are believed to be the source of the observed ultraviolet radiation. Ultraviolet emission and absorption lines provide the best diagnostics for the composition of the surrounding material. Seen in visible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
