The following outline is provided as an overview of and topical guide to physics:
Quantum suicide is a thought experiment in quantum mechanics and the philosophy of physics. Purportedly, it can falsify any interpretation of quantum mechanics other than the Everett many-worlds interpretation by means of a variation of the Schrödinger's cat thought experiment, from the cat's point of view. Quantum immortality refers to the subjective experience of surviving quantum suicide. This concept is sometimes conjectured to be applicable to real-world causes of death as well.
The Niels Bohr Institute is a research institute of the University of Copenhagen. The research of the institute spans astronomy, geophysics, nanotechnology, particle physics, quantum mechanics, and biophysics.
A gravitational singularity, spacetime singularity or simply singularity is a condition in which gravity is predicted to be so intense that spacetime itself would break down catastrophically. As such, a singularity is by definition no longer part of the regular spacetime and cannot be determined by "where" or "when". Gravitational singularities exist at a junction between general relativity and quantum mechanics; therefore, the properties of the singularity cannot be described without an established theory of quantum gravity. Trying to find a complete and precise definition of singularities in the theory of general relativity, the current best theory of gravity, remains a difficult problem. A singularity in general relativity can be defined by the scalar invariant curvature becoming infinite or, better, by a geodesic being incomplete.
Lee Smolin is an American theoretical physicist, a faculty member at the Perimeter Institute for Theoretical Physics, an adjunct professor of physics at the University of Waterloo and a member of the graduate faculty of the philosophy department at the University of Toronto. Smolin's 2006 book The Trouble with Physics criticized string theory as a viable scientific theory. He has made contributions to quantum gravity theory, in particular the approach known as loop quantum gravity. He advocates that the two primary approaches to quantum gravity, loop quantum gravity and string theory, can be reconciled as different aspects of the same underlying theory. He also advocates an alternative view on space and time that he calls temporal naturalism. His research interests also include cosmology, elementary particle theory, the foundations of quantum mechanics, and theoretical biology.
Max Erik Tegmark is a Swedish-American physicist, Machine Learning researcher and author. He is best known for his book Life 3.0 about what the world might look like as Artificial intelligence continues to improve. Tegmark is a professor at the Massachusetts Institute of Technology and the president of the Future of Life Institute.
In general relativity, a white hole is a hypothetical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the reverse of a black hole, from which energy-matter, light and information cannot escape. White holes appear in the theory of eternal black holes. In addition to a black hole region in the future, such a solution of the Einstein field equations has a white hole region in its past. This region does not exist for black holes that have formed through gravitational collapse, however, nor are there any observed physical processes through which a white hole could be formed.
The Big Bounce hypothesis is a cosmological model for the origin of the known universe. It was originally suggested as a phase of the cyclic model or oscillatory universe interpretation of the Big Bang, where the first cosmological event was the result of the collapse of a previous universe. It receded from serious consideration in the early 1980s after inflation theory emerged as a solution to the horizon problem, which had arisen from advances in observations revealing the large-scale structure of the universe.
Carlo Rovelli is an Italian theoretical physicist and writer who has worked in Italy, the United States and, since 2000, in France. He is also currently a Distinguished Visiting Research Chair at the Perimeter Institute, and core member of the Rotman Institute of Philosophy of Western University. He works mainly in the field of quantum gravity and is a founder of loop quantum gravity theory. He has also worked in the history and philosophy of science. He collaborates with several Italian newspapers, including the cultural supplements of the Corriere della Sera, Il Sole 24 Ore and La Repubblica. His popular science book, Seven Brief Lessons on Physics, was originally published in Italian in 2014. It has been translated into 41 languages and has sold over a million copies worldwide. In 2019, he was included by Foreign Policy magazine in a list of 100 most influential global thinkers.
The chronology protection conjecture is a hypothesis first proposed by Stephen Hawking that laws of physics beyond those of standard general relativity prevent time travel on all but microscopic scales - even when the latter theory states that it should be possible. The permissibility of time travel is represented mathematically by the existence of closed timelike curves in some solutions to the field equations of general relativity. The chronology protection conjecture should be distinguished from chronological censorship under which every closed timelike curve passes through an event horizon, which might prevent an observer from detecting the causal violation.
The Fabric of the Cosmos: Space, Time, and the Texture of Reality (2004) is the second book on theoretical physics, cosmology, and string theory written by Brian Greene, professor and co-director of Columbia's Institute for Strings, Cosmology, and Astroparticle Physics (ISCAP).
Sean Michael Carroll is an American theoretical physicist and philosopher who specializes in quantum mechanics, cosmology, and philosophy of science. Formerly a research professor at the Walter Burke Institute for Theoretical Physics at the California Institute of Technology (Caltech) department of physics, he is currently an external professor at the Santa Fe Institute, and the Homewood Professor of Natural Philosophy at Johns Hopkins University. He has been a contributor to the physics blog Cosmic Variance, and has published in scientific journals such as Nature as well as other publications, including The New York Times, Sky & Telescope and New Scientist. He is known for his atheism, his vocal critique of theism and defense of naturalism. He is considered a prolific public speaker and science populariser. In 2007, Carroll was named NSF Distinguished Lecturer by the National Science Foundation.
Thanu Padmanabhan was an Indian theoretical physicist and cosmologist whose research spanned a wide variety of topics in gravitation, structure formation in the universe and quantum gravity. He published nearly 300 papers and reviews in international journals and ten books in these areas. He made several contributions related to the analysis and modelling of dark energy in the universe and the interpretation of gravity as an emergent phenomenon. He was a Distinguished Professor at the Inter-University Centre for Astronomy and Astrophysics (IUCAA) at Pune, India.
Charles W. Misner was an American physicist and one of the authors of Gravitation. His specialties included general relativity and cosmology. His work has also provided early foundations for studies of quantum gravity and numerical relativity.
The Boltzmann brain thought experiment suggests that it might be more likely for a single brain to spontaneously form in a void, complete with a memory of having existed in our universe, rather than for the entire universe to come about in the manner cosmologists think it actually did. Physicists use the Boltzmann brain thought experiment as a reductio ad absurdum argument for evaluating competing scientific theories.
In astrophysics, an event horizon is a boundary beyond which events cannot affect an observer. Wolfgang Rindler coined the term in the 1950s.
Steven Weinstein is a philosopher at the University of Waterloo, noted particularly for his work on quantum gravity, time, and the interpretation of quantum mechanics.
Francesca Vidotto is an Italian theoretical physicist.
Rana X. Adhikari is an American experimental physicist. He is a professor of physics at the California Institute of Technology (Caltech) and an associate faculty member of the International Centre for Theoretical Sciences of Tata Institute of Fundamental Research (ICTS-TIFR).
