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De Sitter (other)
Willem de Sitter (1872–1934) was a Dutch mathematician, physicist and astronomer. De Sitter may also refer to: * ''De Sitter'' (crater), a lunar crater * 1686 De Sitter, an asteroid People with the surname * Ulbo de Sitter (1902–1980), Dutch geologist * Ulbo de Sitter (sociologist) (1930–2010), Dutch sociologist whose work has been further developed by Jan in 't Veld See also *De Sitter space and anti-de Sitter space, models of spacetime *De Sitter universe A de Sitter universe is a cosmological solution to the Einstein field equations of general relativity, named after Willem de Sitter. It models the universe as spatially flat and neglects ordinary matter, so the dynamics of the universe are dominat ..., a solution to general relativity * De Sitter effect (other) * Sitter (other) {{disambiguation, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Sitter (crater)
De Sitter is a lunar impact crater that is located near the northern limb of the Moon, to the north of the Baillaud–Euctemon crater pair. Due to its location, this crater appears very foreshortened when viewed from the Earth, limiting the detail that can be viewed. The crater also receives sunlight at a low angle, when it is on the sunlit side. This crater forms part of an unusual three-crater cluster, with De Sitter overlying the northeast rim of De Sitter L and the southern rim of De Sitter M. All three craters are of comparable dimension, with the largest being De Sitter M. Where De Sitter overlies the other two craters, its outer rim appears slumped. The rim is more sharply formed along the east-southeast side. Lying next to this part of the rim is De Sitter G, a small formation of two merged craters. The interior floor of De Sitter is somewhat irregular and hummocky, with a slender central ridge near the midpoint. There are several small and tiny craterlets across the inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1686 De Sitter
Events January–March * January 3 – In Madras (now Chennai) in India, local residents employed by the East India Company threaten to boycott their jobs after corporate administrator William Gyfford imposes a house tax on residences within the city walls. Gyfford places security forces at all entrances to the city and threatens to banish anyone who fails to pay their taxes, as well as to confiscate the goods of merchants who refuse to make sales. A compromise is reached the next day on the amount of the taxes. * January 17 – King Louis XIV of France reports the success of the Edict of Fontainebleau, issued on October 22 against the Protestant Huguenots, and reports that after less than three months, the vast majority of the Huguenot population had left the country. * January 29 – In Guatemala, Spanish Army Captain Melchor Rodríguez Mazariegos leads a campaign to conquer the indigenous Maya people in the rain forests of Lacandona, departing f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulbo De Sitter
Lamoraal Ulbo de Sitter (6 March 1902, Groningen – 12 May 1980, Nistelrode) was a Dutch geologist at Leiden University, where he was the founder of the school of structural geology. De Sitter was known for his research on the geology of the Alps and Pyrenees. His father was the astronomer Willem de Sitter (1872–1934), and one of his sons was the Dutch sociologist Ulbo de Sitter (1930–2010). Life and work De Sitter studied geology in Switzerland and later at Leiden, where he was a pupil of geologists Karl Martin (1851–1942) and Berend George Escher (1885–1967). He finished his dissertation in 1925 and then got a job at the Bataafsche Petroleum Maatschappij. After some years he returned to Leiden to become Escher's assistant. De Sitter's task was to supervise fieldwork and research in the Bergamo Alps (northern Italy). In addition to mapping geological structures, De Sitter also did experimental research on the development and origin of geologic structures like ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ulbo De Sitter (sociologist)
Lamoraal Ulbo de Sitter (April 2, 1930 – December 18, 2010Frans van Eijnatten.In memoriam Ulbo de Sitter" in: ''Cursor, informatie en opinieblad.'' Technische Universiteit Eindhoven, (2) 2011. Accessed 12.2014.) was a Dutch sociologist and Professor of business administration at the Radboud University Nijmegen, known for his seminal work in the field of sociotechnical system in the Netherlands. Biography Born in Jönköping, Sweden, Ulbo de Sitter was named after his father Ulbo de Sitter (1902–1980), a geologist working at the Leiden University. Ulbo, the sociologist, was the grandson of astronomer Willem de Sitter (1872-1934). He studied sociology at the University of Amsterdam, and obtained his PhD in 1970 at the University of Leiden with the thesis, entitled "Leiderschapsvorming en leiderschapsgedrag in een organisatie" (Leadership formation and leadership behavior in an organization). De Sitter had started working as engineer in the merchant navy for four years befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jan In 't Veld
Jan in 't Veld (16 December 1925 – 27 January 2005) was a Dutch aerospace engineer and professor of industrial organization at the Mechanical Engineering Department of the Technical University of Delft. In the Netherlands he was one of the pioneers of the application of systems theory in business administration and management. Biography Born in Rotterdam to Joris in 't Veld, former minister and one of the founders of the management sciences in the Netherlands, In 't Veld studied aeronautical engineering at the Technical University of Delft from 1945 to May 1951. He received his Engineering Degree with a thesis on strength calculations . In 1950 In 't Veld joined Fokker, where he worked as production manager at the Fokker F-27. From 1963 to 1968 he was production director, and directed the production of the Fokker F28. From 1968 to 1993 he was Professor of Industrial Organisation at the Faculty of Mechanical Engineering and the Faculty of Aerospace Engineering at the Delft Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Sitter Space
In mathematical physics, ''n''-dimensional de Sitter space (often abbreviated to dS''n'') is a maximally symmetric Lorentzian manifold with constant positive scalar curvature. It is the Lorentzian analogue of an ''n''-sphere (with its canonical Riemannian metric). The main application of de Sitter space is its use in general relativity, where it serves as one of the simplest mathematical models of the universe consistent with the observed accelerating expansion of the universe. More specifically, de Sitter space is the maximally symmetric vacuum solution of Einstein's field equations with a positive cosmological constant \Lambda (corresponding to a positive vacuum energy density and negative pressure). There is cosmological evidence that the universe itself is asymptotically de Sitter, i.e. it will evolve like the de Sitter universe in the far future when dark energy dominates. de Sitter space and anti-de Sitter space are named after Willem de&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-de Sitter Space
In mathematics and physics, ''n''-dimensional anti-de Sitter space (AdS''n'') is a maximally symmetric Lorentzian manifold with constant negative scalar curvature. Anti-de Sitter space and de Sitter space are named after Willem de Sitter (1872–1934), professor of astronomy at Leiden University and director of the Leiden Observatory. Willem de Sitter and Albert Einstein worked together closely in Leiden in the 1920s on the spacetime structure of the universe. Manifolds of constant curvature are most familiar in the case of two dimensions, where the elliptic plane or surface of a sphere is a surface of constant positive curvature, a flat (i.e., Euclidean) plane is a surface of constant zero curvature, and a hyperbolic plane is a surface of constant negative curvature. Einstein's general theory of relativity places space and time on equal footing, so that one considers the geometry of a unified spacetime instead of considering space and time separately. The cases of spacetime o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Sitter Universe
A de Sitter universe is a cosmological solution to the Einstein field equations of general relativity, named after Willem de Sitter. It models the universe as spatially flat and neglects ordinary matter, so the dynamics of the universe are dominated by the cosmological constant, thought to correspond to dark energy in our universe or the inflaton field in the early universe. According to the models of inflation and current observations of the accelerating universe, the concordance models of physical cosmology are converging on a consistent model where our universe was best described as a de Sitter universe at about a time t = 10^ seconds after the fiducial Big Bang singularity, and far into the future. Mathematical expression A de Sitter universe has no ordinary matter content but with a positive cosmological constant (\Lambda) that sets the expansion rate, H. A larger cosmological constant leads to a larger expansion rate: :H \propto \sqrt , where the constants of proportio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
De Sitter Effect (other)
In astrophysics, the term de Sitter effect (named after the Dutch physicist Willem de Sitter) has been applied to two unrelated phenomena: * De Sitter double star experiment * De Sitter precession The geodetic effect (also known as geodetic precession, de Sitter precession or de Sitter effect) represents the effect of the curvature of spacetime, predicted by general relativity, on a vector carried along with an orbiting body. For example, ... – also known as ''geodetic precession'' or the ''geodetic effect'' {{disambig Astrophysics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
