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Invariant Set Postulate
The invariant set postulate concerns the possible relationship between fractal geometry and quantum mechanics and in particular the hypothesis that the former can assist in resolving some of the challenges posed by the latter. It is underpinned by nonlinear dynamical systems theory and black hole thermodynamics. Author The proposer of the postulate is climate scientist and physicist Tim Palmer. Palmer completed a PhD at the University of Oxford under Dennis Sciama, the same supervisor that Stephen Hawking had and then worked with Hawking himself at the University of Cambridge on supergravity theory. He later switched to meteorology and has established a reputation pioneering ensemble forecasting.See for example Buizza, R., & Palmer, T. N., (1998) "Impact of ensemble size on the skill and the potential skill of an ensemble prediction system." Mon. Wea. Rev., 126, 9, pp. 2503-2518. He now works at the European Centre for Medium-Range Weather Forecasts in Reading, England.Buchanan, M ...
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Bohr–Einstein Debates
The Bohr–Einstein debates were a series of public disputes about quantum mechanics between Albert Einstein and Niels Bohr. Their debates are remembered because of their importance to the philosophy of science, since the disagreements and the outcome of Bohr's version of quantum mechanics that became the prevalent view form the root of the modern understanding of physics. Most of Bohr's version of the events held in Solvay in 1927 and other places was first written by Bohr decades later in an article titled, "Discussions with Einstein on Epistemological Problems in Atomic Physics". From Albert Einstein: Philosopher-Scientist (1949), publ. Cambridge University Press, 1949. Niels Bohr's report of conversations with Einstein. Based on the article, the philosophical issue of the debate was whether Bohr's Copenhagen Interpretation of quantum mechanics, which centered on his belief of complementarity, was valid in explaining nature. Despite their differences of opinion and the succee ...
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Todd Brun
Todd A. Brun is an American engineer and physicist, currently a professor at University of Southern California. He is a Fellow of the American Physical Society for "contributions to quantum theory and quantum information science, including decoherence and continuous quantum measurement, quantum computation, and quantum error correction." He is a coinventor of the method of entanglement-assisted quantum error correction, which allows for the use of shared entanglement in quantum error correction and for producing a quantum error correction code from an arbitrary classical error correction In information theory and coding theory with applications in computer science and telecommunication, error detection and correction (EDAC) or error control are techniques that enable reliable delivery of digital data over unreliable communic ... code. References Year of birth missing (living people) Living people Fellows of the American Physical Society American electrical enginee ...
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Robert Spekkens
Robert W. Spekkens is a Canadian theoretical quantum physicist working in the fields of quantum foundations and quantum information. He is known for his work on epistemic view of quantum states (in particular the Spekkens toy model), quantum contextuality, quantum resource theories and quantum causality. He co-edited the book ''Quantum Theory: Informational Foundations and Foils''. Career Spekkens is a faculty member and the leader of the quantum causal inference initiative at Perimeter Institute for Theoretical Physics. He regularly teaches the course on quantum foundations in the Perimeter Scholars International master's program. He is an adjunct faculty in the Department of Physics of the University of Waterloo and an adjunct research fellow in the Centre for Quantum Dynamics of Griffith University Griffith University is a public research university in South East Queensland on the east coast of Australia. Formally founded in 1971, Griffith opened its doors in 19 ...
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Gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light. On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans (the corresponding antipodal tide is caused by the inertia of the Earth and Moon orbiting one another). Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing th ...
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Perimeter Institute For Theoretical Physics
Perimeter Institute for Theoretical Physics (PI, Perimeter, PITP) is an independent research centre in foundational theoretical physics located in Waterloo, Ontario, Canada. It was founded in 1999. The institute's founding and major benefactor is Canadian entrepreneur and philanthropist Mike Lazaridis. The original building, designed by Saucier + Perrotte, opened in 2004 and was awarded a Governor General's Medal for Architecture in 2006. The Stephen Hawking Centre, designed by Teeple Architects, was opened in 2011 and was LEED Silver certified in 2015. In addition to research, Perimeter also provides scientific training and educational outreach activities to the general public. This is done in part through Perimeter's Educational Outreach team. History Lazaridis' initial donation of $100 million was announced on October 23, 2000, believed to be the biggest private donation in Canadian history to that point. A subsequent personal donation of $50 million was made on June 4, ...
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Action At A Distance (physics)
In physics, action at a distance is the concept that an object can be affected without being physically touched (as in mechanical contact) by another object. That is, it is the non-local interaction of objects that are separated in space. Non-contact forces is action at a distance affecting specifically an object's motion. This term was used most often in the context of early theories of gravity and electromagnetism to describe how an object responds to the influence of distant objects. For example, Coulomb's law and Newton's law of universal gravitation are such early theories. More generally, "action at a distance" describes the failure of early atomistic and mechanistic theories which sought to reduce all physical interaction to collision. The exploration and resolution of this problematic phenomenon led to significant developments in physics, from the concept of a field, to descriptions of quantum entanglement and the mediator particles of the Standard Model. Electric ...
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Kochen–Specker Theorem
In quantum mechanics, the Kochen–Specker (KS) theorem, also known as the Bell–Kochen–Specker theorem, is a "no-go" theorem proved by John S. Bell in 1966 and by Simon B. Kochen and Ernst Specker in 1967. It places certain constraints on the permissible types of hidden-variable theories, which try to explain the predictions of quantum mechanics in a context-independent way. The version of the theorem proved by Kochen and Specker also gave an explicit example for this constraint in terms of a finite number of state vectors. The theorem is a complement to Bell's theorem (to be distinguished from the (Bell–)Kochen–Specker theorem of this article). While Bell's theorem established nonlocality to be a feature of any hidden variable theory that recovers the predictions of quantum mechanics, the KS theorem established contextuality to be an inevitable feature of such theories. The theorem proves that there is a contradiction between two basic assumptions of the hidden-var ...
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Invariant (mathematics)
In mathematics, an invariant is a property of a mathematical object (or a class of mathematical objects) which remains unchanged after operations or transformations of a certain type are applied to the objects. The particular class of objects and type of transformations are usually indicated by the context in which the term is used. For example, the area of a triangle is an invariant with respect to isometries of the Euclidean plane. The phrases "invariant under" and "invariant to" a transformation are both used. More generally, an invariant with respect to an equivalence relation is a property that is constant on each equivalence class. Invariants are used in diverse areas of mathematics such as geometry, topology, algebra and discrete mathematics. Some important classes of transformations are defined by an invariant they leave unchanged. For example, conformal maps are defined as transformations of the plane that preserve angles. The discovery of invariants is an importa ...
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Chaos Theory
Chaos theory is an interdisciplinary area of scientific study and branch of mathematics focused on underlying patterns and deterministic laws of dynamical systems that are highly sensitive to initial conditions, and were once thought to have completely random states of disorder and irregularities. Chaos theory states that within the apparent randomness of chaotic complex systems, there are underlying patterns, interconnection, constant feedback loops, repetition, self-similarity, fractals, and self-organization. The butterfly effect, an underlying principle of chaos, describes how a small change in one state of a deterministic nonlinear system can result in large differences in a later state (meaning that there is sensitive dependence on initial conditions). A metaphor for this behavior is that a butterfly flapping its wings in Brazil can cause a tornado in Texas. Small differences in initial conditions, such as those due to errors in measurements or due to rounding error ...
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State Space
A state space is the set of all possible configurations of a system. It is a useful abstraction for reasoning about the behavior of a given system and is widely used in the fields of artificial intelligence and game theory. For instance, the toy problem Vacuum World has a discrete finite state space in which there are a limited set of configurations that the vacuum and dirt can be in. A "counter" system, where states are the natural numbers starting at 1 and are incremented over time has an infinite discrete state space. The angular position of an undamped pendulum is a continuous (and therefore infinite) state space. Definition In the theory of dynamical systems, the state space of a discrete system defined by a function ''ƒ'' can be modeled as a directed graph where each possible state of the dynamical system is represented by a vertex with a directed edge from ''a'' to ''b'' if and only if ''ƒ''(''a'') = ''b''. This is known as a state diagram. For a co ...
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