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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, receiving his degree in 1970. Fairall discovered and named Fairall 9, the most luminous Luminous may refer to: * Luminous flame, a flame emitting visible light Music * Luminous (group), a South Korean boy band * ''Luminous'' (EP), an EP by Cesium 137 * ''Luminous'' (John Hicks and Elise Wood album), 1985–88 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South African People
The population of South Africa is about 58.8 million people of diverse origins, cultures, Languages of South Africa, languages, and Religion in South Africa, religions. 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 Population Earlier Censuses, 1904 to 2011 1904 Census South African population figures for the 1904 Census.Smuts I: The Sanguine Years 1870–1919, W.K. Hancock, Cambridge University Press, 1962, pg 219 1960 Census Sources: ''Statesman's Yearbook, Statesman's Year-Book'' 1967–1968; ''Europa World Year Book, Europa Year Book'' 1969 1904-85 national census numbers Bantustan demographics were removed from South African census data during Apartheid and for this reas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They 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 usually 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 C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large-scale Structure Of The Universe
The observable universe is a ball-shaped region of the universe comprising all matter that can be observed from Earth or its space-based telescopes and exploratory probes at the present time, because the electromagnetic radiation from these objects has had time to reach the Solar System and Earth since the beginning of the cosmological expansion. There may be 2 trillion galaxies in the observable universe, although that number was reduced in 2021 to only several hundred billion based on data from ''New Horizons''. Assuming the universe is isotropic, the distance to the edge of the observable universe is roughly the same in every direction. That is, the observable universe is a spherical region centered on the observer and is unique for every unique observational position. 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 ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Galaxy Filament
In cosmology, galaxy filaments (subtypes: supercluster complexes, galaxy walls, and galaxy sheets) Boris V. Komberg, Andrey V. Kravtsov, Vladimir N. Lukash; "The search and investigation of the Large Groups of Quasars" ; ;R.G. Clowes; "Large Quasar Groups - A Short Review"; ''The New Era of Wide Field Astronomy'', ASP Conference Series, vol. 232.; 2001; Astronomical Society of the Pacific; ; are the largest known structures in the universe, consisting of walls of gravitationally bound galaxy superclusters. These massive, thread-like formations can reach 80 parsec#Megaparsecs and gigaparsecs, megaparsecs ''h''−1 (or of the order of 160 to 260 million light-years) and form the boundaries between large void (astronomy), voids. Formation In the Lambda-CDM model, standard model of the evolution of the universe, galactic filaments form along and follow web-like strings of dark matter—also referred to as the galactic web or cosmic web. It is thought that this dark matter dictates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Void (astronomy)
Cosmic voids (also known as dark space) are vast spaces between filaments (the largest-scale structures in the universe), which contain very few or no galaxies. The cosmological evolution of the void regions differs drastically from the evolution of the Universe as a whole: there is a long stage when 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 for an observer. Voids typically have a diameter of 10 to 100 megaparsecs (30 to 300 million light-years); particularly large voids, defined by the absence of rich superclusters, are sometimes called supervoids. They were first discovered in 1978 in a pioneering study by Stephen Gregory and Laird A. Thompson at the Kitt Peak National Observatory. Voids are believed to have been formed by baryon acoustic oscillations in the Big Bang, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iziko South African Museum
The Iziko South African 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. ''Iziko'' is a Xhosa word meaning "hearth". History The South African Museum was founded by Lord Charles Somerset in 1825 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 classification similar to the evolutionary models that were prominent in European and American museums in the late nineteenth and early twentieth centuries. The focus on natural history encouraged the notion that very little divided the animal world from the human subjects who were documented. This continued until the 1990s with the reservation of cultural history museums for the display of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Cape Town
The University of Cape Town (UCT) ( af, Universiteit van Kaapstad, xh, Yunibesithi ya yaseKapa) is a 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 oldest university in Sub-Saharan Africa in continuous operation. UCT is organised in 57 departments across six faculties offering bachelor's ( NQF 7) to doctoral degrees ( NQF 10) solely in the English language. Home to 30 000 students, it encompasses six campuses in the Capetonian suburbs of Rondebosch, Hiddingh, Observatory, Mowbray, and the Waterfront. Although UCT was founded by a private act of Parliament in 1918, the Statute of the University of Cape Town (issued in 2002 in terms of the Higher Education Act) sets out its structure and roles and places the Chancellor - currently, Dr Precious Moloi Motsepe - as the ceremonial figurehead and invests real leadership ... [...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); Gerardo (Italian, and Spanish); Geraldo (Portuguese); Gherardo (Italian); Gherardi (Northern Italian, now only a surname); Gérard (variant forms ''Girard'' and ''Guérard'', now only surnames, French); Gearóid (Irish); Gerhardt and Gerhart/Gerhard/Gerhardus (German, Dutch, and Afrikaans); Gellért ( Hungarian); Gerardas ( Lithuanian) and Gerards/Ģirts ( Latvian); Γεράρδης (Greece). A few abbreviated forms are Gerry and Jerry (English); Gerd (German) and Gert (Afrikaans and Dutch); Gerrit (A ... [...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 infer 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 400 time ... [...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 research university in Austin, Texas. It was founded in 1883 and is the oldest institution in the University of Texas System. With 40,916 undergraduate students, 11,075 graduate students and 3,133 teaching faculty as of Fall 2021, it is also the largest institution in the system. It is ranked among the top universities in the world by major college and university rankings, and admission to its programs is considered highly selective. UT Austin is considered one of the United States's Public Ivies. The university is a major center for academic research, with research expenditures totaling $679.8 million for fiscal year 2018. It joined the Association of American Universities in 1929. The university houses seven museums and seventeen libraries, including the LBJ Presidential Library and the Blanton Museum of Art, and operates various auxiliary research facilities, such as the J. J. Pickle Research Ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luminosity
Luminosity is an absolute measure of radiated electromagnetic power (light), the radiant power emitted by a light-emitting object over time. In astronomy, luminosity is the total amount of electromagnetic energy emitted per unit of time by a star, galaxy, or other astronomical object. 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 luminosity of the Sun, ''L''⊙. Luminosity can also be given in terms of the astronomical magnitude system: the 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 filter band. In contrast, the term ''brightness'' in astronomy is generally used to refer to an object's apparent brightness: that is, how bright an object appears to an observer. Apparent brightness depends on both the lumin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seyfert Galaxy
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) 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 light, most Seyfert galaxies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
