The many-worlds interpretation (MWI) is a philosophical position about how the mathematics used in quantum mechanics relates to physical reality. It asserts that the universal wavefunction is objectively real, and that there is no wave function collapse. This implies that all possible outcomes of quantum measurements are physically realized in some "world" or universe. In contrast to some other interpretations, the evolution of reality as a whole in MWI is rigidly deterministic and local. Many-worlds is also called the relative state formulation or the Everett interpretation, after physicist Hugh Everett, who first proposed it in 1957. Bryce DeWitt popularized the formulation and named it many-worlds in the 1970s.
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 generalises 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.
Paul Adrien Maurice Dirac was an English mathematical and theoretical physicist who is considered to be one of the founders of quantum mechanics and quantum electrodynamics. He is credited with laying the foundations of quantum field theory. He was the Lucasian Professor of Mathematics at the University of Cambridge, a professor of physics at Florida State University and the University of Miami, and a 1933 Nobel Prize in Physics recipient.
In the philosophy of space and time, eternalism is an approach to the ontological nature of time, which takes the view that all existence in time is equally real, as opposed to presentism or the growing block universe theory of time, in which at least the future is not the same as any other time. Some forms of eternalism give time a similar ontology to that of space, as a dimension, with different times being as real as different places, and future events are "already there" in the same sense other places are already there, and that there is no objective flow of time.
In philosophy, philosophy of physics deals with conceptual and interpretational issues in modern physics, many of which overlap with research done by certain kinds of theoretical physicists. Philosophy of physics can be broadly divided into three areas:
John Stewart Bell FRS was a physicist from Northern Ireland and the originator of Bell's theorem, an important theorem in quantum physics regarding hidden-variable theories.
Edward Arthur Milne FRS was a British astrophysicist and mathematician.
George Francis Rayner Ellis, FRS, Hon. FRSSAf, 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. 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.
Richard Chace Tolman was an American mathematical physicist and physical chemist who made many contributions to statistical mechanics. He also made important contributions to theoretical cosmology in the years soon after Einstein's discovery of general relativity. He was a professor of physical chemistry and mathematical physics at the California Institute of Technology (Caltech).
Artur Konrad Ekert is a British-Polish professor of quantum physics at the Mathematical Institute, University of Oxford, professorial fellow in quantum physics and cryptography at Merton College, Oxford, Lee Kong Chian Centennial Professor at the National University of Singapore and the founding director of the Centre for Quantum Technologies (CQT). His research interests extend over most aspects of information processing in quantum-mechanical systems, with a focus on quantum communication and quantum computation. He is best known as one of the pioneers of quantum cryptography.
In physics, aether theories propose the existence of a medium, a space-filling substance or field as a transmission medium for the propagation of electromagnetic or gravitational forces. "Since the development of special relativity, theories using a substantial aether fell out of use in modern physics, and are now replaced by more abstract models."
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.
Andrew Martin Steane is Professor of physics at the University of Oxford. He is also a fellow of Exeter College, Oxford.
Jeremy Nicholas Butterfield FBA is a philosopher at the University of Cambridge, noted particularly for his work on philosophical aspects of quantum theory, relativity theory and classical mechanics.
Robert Weingard was a philosopher of science and professor of philosophy at Rutgers University.
Mark Sheard Child FRS is a British chemist, and Emeritus Fellow of St Edmund Hall, Oxford.
Simon Wolfe Saunders is a British philosopher of physics. He is noted for his work on quantum mechanics, on identity and indiscernibility in physics, and on structural realism.
The relationship between mathematics and physics has been a subject of study of philosophers, mathematicians and physicists since antiquity, and more recently also by historians and educators. Generally considered a relationship of great intimacy, mathematics has been described as "an essential tool for physics" and physics has been described as "a rich source of inspiration and insight in mathematics".
Lowell S. Brown was an American theoretical physicist, a retired Staff Scientist and Laboratory Fellow at Los Alamos National Laboratory, and Professor Emeritus of physics at University of Washington. He was a student of Julian Schwinger at Harvard University and a recipient of the John Simon Guggenheim Memorial Foundation Fellowship. Brown authored a book on Quantum Field Theory that has received over 5,000 citations, and he has authored or co-authored over 150 articles that have accumulated over 11,000 citations.
Laurie Mark Brown is an American theoretical physicist and historian of quantum field theory and elementary particle physics.
