George F R Ellis | |
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Born | George Francis Rayner Ellis 11 August 1939 |
Nationality | South African |
Education | Michaelhouse |
Alma mater | |
Known for | Theoretical physical cosmology |
Awards | Templeton Prize 2004 Prix Georges Lemaître 2019 [1] |
Scientific career | |
Fields | Cosmology |
Institutions | |
Doctoral advisor | Dennis W. Sciama [2] |
Part of a series on |
Physical cosmology |
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George Francis Rayner Ellis, FRS, Hon. FRSSAf (born 11 August 1939), is the emeritus distinguished professor of complex systems in the Department of Mathematics and Applied Mathematics at the University of Cape Town in South Africa. He co-authored The Large Scale Structure of Space-Time with University of Cambridge physicist Stephen Hawking, published in 1973, and is considered one of the world's leading theorists in cosmology. [3] From 1989 to 1992 he served as president of the International Society on General Relativity and Gravitation. He is a past president of the International Society for Science and Religion. He is an A-rated researcher with the NRF.
Ellis, an active Quaker, [4] [5] [6] was a vocal opponent of apartheid during the National Party reign in the 1970s and 1980s, [7] and it is during this period that Ellis's research focused on the more philosophical aspects of cosmology, for which he won the Templeton Prize in 2004. [8] He was also awarded the Order of the Star of South Africa by Nelson Mandela, in 1999[ citation needed ] . On 18 May 2007, he was elected a fellow of the British Royal Society [ citation needed ] .
Born in 1939 to George Rayner Ellis, a newspaper editor, and Gwendoline Hilda MacRobert Ellis in Johannesburg, George Francis Rayner Ellis attended the University of Cape Town, where he graduated with honours in 1960 with a Bachelor of Science degree in physics with distinction[ citation needed ] . He represented the university in fencing, rowing and flying[ citation needed ] .
While a student at St John's College, Cambridge, where he received a PhD in applied maths and theoretical physics in 1964, he was on college rowing teams[ citation needed ] .
At Cambridge, Ellis served as a research fellow from 1965 to 1967, was assistant lecturer in the Department of Applied Mathematics and Theoretical Physics until 1970, and was then appointed university lecturer, serving until 1974[ citation needed ] .
Ellis became a visiting professor at the Enrico Fermi Institute at the University of Chicago in 1970, a lecturer at the Cargese Summer School in Corsica in 1971 and the Erice Summer School in Sicily in 1972, and a visiting H3 professor at the University of Hamburg, also in 1972.
The following year, Ellis co-wrote The Large Scale Structure of Space-Time with Stephen Hawking, debuting at a strategic moment in the development of General Relativity Theory.
In the following year, Ellis returned to South Africa to accept an appointment as professor of applied mathematics at the University of Cape Town, a position he held until his retirement in 2005.
In 2005 Ellis appeared as a guest speaker at the Nobel Conference in St. Peter, Minnesota.
George Ellis has worked for many decades on anisotropic cosmologies (Bianchi models) and inhomogeneous universes, and on the philosophy of cosmology. [9] He is currently writing on the emergence of complexity, and the way this is enabled by top-down causation in the hierarchy of complexity. [10] Recently Ellis has also collaborated with Teppo Felin, Denis Noble, and Jan Koenderink on a set of articles published in the journal Genome Biology. [11] [12] In terms of philosophy of science, Ellis is a Platonist. [13]
Ellis has over 500 published articles; including 17 in Nature. Notable papers include:
In 2019 Rhodes University in Grahamstown announced it would award Ellis an honorary doctorate in laws (LLD, hc) [15]
The Big Bang was the initiation of the continuing expansion of the universe from a state of high density and temperature. It was first proposed as a physical theory in 1931 by Roman Catholic priest and physicist Georges Lemaître when he suggested the universe emerged from a "primeval atom". Various cosmological models of the Big Bang explain the evolution of the observable universe from the earliest known periods through its subsequent large-scale form. These models offer a comprehensive explanation for a broad range of observed phenomena, including the abundance of light elements, the cosmic microwave background (CMB) radiation, and large-scale structure. The overall uniformity of the universe, known as the flatness problem, is explained through cosmic inflation: a sudden and very rapid expansion of space during the earliest moments. However, physics currently lacks a widely accepted theory of quantum gravity that can successfully model the earliest conditions of the Big Bang.
Physical cosmology is a branch of cosmology concerned with the study of cosmological models. A cosmological model, or simply cosmology, provides a description of the largest-scale structures and dynamics of the universe and allows study of fundamental questions about its origin, structure, evolution, and ultimate fate. Cosmology as a science originated with the Copernican principle, which implies that celestial bodies obey identical physical laws to those on Earth, and Newtonian mechanics, which first allowed those physical laws to be understood.
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the curvature of spacetime is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations.
In general relativity, a naked singularity is a hypothetical gravitational singularity without an event horizon.
The following is a timeline of gravitational physics and general relativity.
The Large Scale Structure of Space–Time is a 1973 treatise on the theoretical physics of spacetime by the physicist Stephen Hawking and the mathematician George Ellis. It is intended for specialists in general relativity rather than newcomers.
In theoretical physics, the Einstein–Cartan theory, also known as the Einstein–Cartan–Sciama–Kibble theory, is a classical theory of gravitation, one of several alternatives to general relativity. The theory was first proposed by Élie Cartan in 1922.
Werner Israel, was a theoretical physicist known for his contributions to gravitational theory, and especially to the understanding of black holes.
Dennis William Siahou Sciama, was an English physicist who, through his own work and that of his students, played a major role in developing British physics after the Second World War. He was the PhD supervisor to many famous physicists and astrophysicists, including John D. Barrow, David Deutsch, George F. R. Ellis, Stephen Hawking, Adrian Melott and Martin Rees, among others; he is considered one of the fathers of modern cosmology.
The Weyl curvature hypothesis, which arises in the application of Albert Einstein's general theory of relativity to physical cosmology, was introduced by the British mathematician and theoretical physicist Roger Penrose in an article in 1979 in an attempt to provide explanations for two of the most fundamental issues in physics. On the one hand, one would like to account for a universe which on its largest observational scales appears remarkably spatially homogeneous and isotropic in its physical properties ; on the other hand, there is the deep question on the origin of the second law of thermodynamics.
In physical cosmology, cosmological perturbation theory is the theory by which the evolution of structure is understood in the Big Bang model. Cosmological perturbation theory may be broken into two categories: Newtonian or general relativistic. Each case uses its governing equations to compute gravitational and pressure forces which cause small perturbations to grow and eventually seed the formation of stars, quasars, galaxies and clusters. Both cases apply only to situations where the universe is predominantly homogeneous, such as during cosmic inflation and large parts of the Big Bang. The universe is believed to still be homogeneous enough that the theory is a good approximation on the largest scales, but on smaller scales more involved techniques, such as N-body simulations, must be used. When deciding whether to use general relativity for perturbation theory, note that Newtonian physics is only applicable in some cases such as for scales smaller than the Hubble horizon, where spacetime is sufficiently flat, and for which speeds are non-relativistic.
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Robert Geroch is an American theoretical physicist and professor at the University of Chicago. He has worked prominently on general relativity and mathematical physics and has promoted the use of category theory in mathematics and physics. He was the Ph.D. supervisor for Abhay Ashtekar, Basilis Xanthopoulos and Gary Horowitz. He also proved an important theorem in spin geometry.
Mark Trodden is a theoretical cosmologist and particle physicist. He is the Fay R. and Eugene L. Langberg Professor of Physics and Co-Director of the Center for Particle Cosmology at the University of Pennsylvania.
The Bousso bound captures a fundamental relation between quantum information and the geometry of space and time. It appears to be an imprint of a unified theory that combines quantum mechanics with Einstein's general relativity. The study of black hole thermodynamics and the information paradox led to the idea of the holographic principle: the entropy of matter and radiation in a spatial region cannot exceed the Bekenstein–Hawking entropy of the boundary of the region, which is proportional to the boundary area. However, this "spacelike" entropy bound fails in cosmology; for example, it does not hold true in our universe.
C.V.Vishveshwara was an Indian scientist and black hole physicist. Specializing in Einstein's General Relativity, he worked extensively on the theory of black holes and made major contributions to this field of research since its very beginning. He is popularly known as the 'black hole man of India'.
Teppo Felin is the Douglas D. Anderson Professor of Strategy & Entrepreneurship at the Huntsman School of Business at Utah State University. He is also the Founding Director of the Institute for Interdisciplinary Study. From 2013 to 2021, Felin was Professor of Strategy at the Saïd Business School at the University of Oxford. His current research focuses on cognition, rationality, perception, organizational economics, markets and strategy.
Thomas Hertog is a Belgian cosmologist at KU Leuven university and was a key collaborator of Professor Stephen Hawking.
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