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Gravitational Decoherence
Gravitational decoherence is a term for hypothetical mechanisms by which gravitation can act on quantum mechanical systems to produce decoherence. Advocates of gravitational decoherence include Frigyes Károlyházy, Roger Penrose and Lajos Diósi. A number of experiments have been proposed to test the gravitational decoherence hypothesis. Dmitriy Podolskiy and Robert Lanza have argued that gravitational decoherence may explain the existence of the arrow of time. See also * Penrose interpretation * Diósi–Penrose model * Objective-collapse theory * Quantum gravity Quantum gravity (QG) is a field of theoretical physics that seeks to describe gravity according to the principles of quantum mechanics; it deals with environments in which neither gravitational nor quantum effects can be ignored, such as in the vi ... References Quantum mechanics Quantum gravity {{quantum-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the circ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Mechanical
Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, quantum field theory, quantum technology, and quantum information science. Classical physics, the collection of theories that existed before the advent of quantum mechanics, describes many aspects of nature at an ordinary (macroscopic) scale, but is not sufficient for describing them at small (atomic and subatomic) scales. Most theories in classical physics can be derived from quantum mechanics as an approximation valid at large (macroscopic) scale. Quantum mechanics differs from classical physics in that energy, momentum, angular momentum, and other quantities of a bound system are restricted to discrete values ( quantization); objects have characteristics of both particles and waves (wave–particle duality); and there are limits to how ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Decoherence
Quantum decoherence is the loss of quantum coherence. In quantum mechanics, particles such as electrons are described by a wave function, a mathematical representation of the quantum state of a system; a probabilistic interpretation of the wave function is used to explain various quantum effects. As long as there exists a definite phase relation between different states, the system is said to be coherent. A definite phase relationship is necessary to perform quantum computing on quantum information encoded in quantum states. Coherence is preserved under the laws of quantum physics. If a quantum system were perfectly isolated, it would maintain coherence indefinitely, but it would be impossible to manipulate or investigate it. If it is not perfectly isolated, for example during a measurement, coherence is shared with the environment and appears to be lost with time; a process called quantum decoherence. As a result of this process, quantum behavior is apparently lost, just as ene ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frigyes Károlyházy
Frigyes Károlyházy (Hungarian: Károlyházy Frigyes) (Budapest, 28 December 1929 - Budapest, 2 July 2012) was a Hungarian theoretical physicist, textbook writer and university professor. He was an extremely talented teacher, trying to make complex physical problems understandable to the laity as well. Education Károlyházy graduated from the Piarista Gimnázium in Budapest in 1948, and then was admitted to the mathematics and physics teaching department of Eötvös Loránd University . He was admitted to the Eötvös Collegium at the same time as the university, and was expelled after a year due to the political situation in the country (he refused to support the conviction of László Rajk). There was no theoretical physics training in Hungary at that time, so he applied here, and then a few years later, when he had the opportunity, he re-enrolled in the research physics department. He graduated from the university in 1952 with a doctorate twenty years later, in 1972in. Vi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roger Penrose
Sir Roger Penrose (born 8 August 1931) is an English mathematician, mathematical physicist, philosopher of science and Nobel Laureate in Physics. He is Emeritus Rouse Ball Professor of Mathematics in the University of Oxford, an emeritus fellow of Wadham College, Oxford, and an honorary fellow of St John's College, Cambridge and University College London. Penrose has contributed to the mathematical physics of general relativity and cosmology. He has received several prizes and awards, including the 1988 Wolf Prize in Physics, which he shared with Stephen Hawking for the Penrose–Hawking singularity theorems, and one half of the 2020 Nobel Prize in Physics "for the discovery that black hole formation is a robust prediction of the general theory of relativity". He is regarded as one of the greatest living physicists, mathematicians and scientists, and is particularly noted for the breadth and depth of his work in both natural and formal sciences. Early life and education Bor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lajos Diósi
Lajos () is a Hungarian masculine given name, cognate to the English Louis. People named Lajos include: Hungarian monarchs: * Lajos I, 1326-1382 (ruled 1342-1382) * Lajos II, 1506-1526 (ruled 1516-1526) In Hungarian politics: * Lajos Aulich, second Minister of War of Hungary * Lajos Batthyány, first Prime Minister of Hungary * Count Lajos Batthyány de Németújvár, county head of Győr and Governor of Fiume * Lajos Dinnyés, Prime Minister of Hungary from 1947 to 1948 * Lajos Kossuth, Hungarian lawyer, politician and Regent of Hungary In football: * Lajos Baróti, coach of the Hungary national football team * Lajos Czeizler, Hungarian football coach * Lajos Détári, retired Hungarian football player * Lajos Sătmăreanu, former Romanian football player * Lajos Tichy, Hungarian footballer In art: * Lajos Csordák, Hungarian/Slovak painter * Lajos Markos, Hungarian American painter * Lajos Koltai, Hungarian cinematographer and film director In Hungarian literature: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dmitriy Podolskiy
Dmitri (russian: Дми́трий); Church Slavic form: Dimitry or Dimitri (); ancient Russian forms: D'mitriy or Dmitr ( or ) is a male given name common in Orthodox Christian culture, the Russian version of Greek Demetrios (Δημήτριος ''Dēmētrios'' ). The meaning of the name is "devoted to, dedicated to, or follower of Demeter" (Δημήτηρ, ''Dēmētēr''), "mother-earth", the Greek goddess of agriculture. Short forms of the name from the 13th–14th centuries are Mit, Mitya, Mityay, Mit'ka or Miten'ka (, or ); from the 20th century (originated from the Church Slavic form) are Dima, Dimka, Dimochka, Dimulya, Dimusha etc. (, etc.) St. Dimitri's Day The feast of the martyr Saint Demetrius of Thessalonica is celebrated on Saturday before November 8 ld Style October 26 The name day (именины): October 26 (November 8 on the Julian Calendar) See also: Eastern Orthodox liturgical calendar. The Saturday before October 26/November 8 is called Demetrius Saturd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Lanza
Robert Lanza (born 11 February 1956 in Boston, Massachusetts) is an American medical doctor and scientist, currently Head of Astellas Global Regenerative Medicine, and Chief Scientific Officer of the Astellas Institute for Regenerative Medicine. He is an Adjunct Professor at Wake Forest University School of Medicine. Early life and education Lanza was born in Boston, Massachusetts, and grew up south of there, in Stoughton, Massachusetts. Lanza "altered the genetics of chickens in his basement", and came to the attention of Harvard Medical School researchers when he appeared at the university with his results. Jonas Salk, B. F. Skinner, and Christiaan Barnard mentored Lanza over the next ten years. Lanza attended the University of Pennsylvania, receiving BA and MD degrees. There, he was a Benjamin Franklin Scholar and a University Scholar. Lanza was also a Fulbright Scholar. He currently resides in Clinton, Massachusetts. Career Stem cell research Lanza was part of the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arrow Of Time
The arrow of time, also called time's arrow, is the concept positing the "one-way direction" or " asymmetry" of time. It was developed in 1927 by the British astrophysicist Arthur Eddington, and is an unsolved general physics question. This direction, according to Eddington, could be determined by studying the organization of atoms, molecules, and bodies, and might be drawn upon a four-dimensional relativistic map of the world ("a solid block of paper"). Physical processes at the microscopic level are believed to be either entirely or mostly time-symmetric: if the direction of time were to reverse, the theoretical statements that describe them would remain true. Yet at the macroscopic level it often appears that this is not the case: there is an obvious direction (or ''flow'') of time. Overview The symmetry of time (T-symmetry) can be understood simply as the following: if time were perfectly symmetrical, a video of real events would seem realistic whether played forward ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diósi–Penrose Model
The Diósi–Penrose model was introduced as a possible solution to the measurement problem, where the wave function collapse is related to gravity. The model was first suggested by Lajos Diósi when studying how possible gravitational fluctuations may affect the dynamics of quantum systems. Later, following a different line of reasoning, Roger Penrose arrived at an estimation for the collapse time of a superposition due to gravitational effects, which is the same (within an unimportant numerical factor) as that found by Diósi, hence the name Diósi–Penrose model. However, it should be pointed out that while Diósi gave a precise dynamical equation for the collapse, Penrose took a more conservative approach, estimating only the collapse time of a superposition. The Diósi model In the Diósi model, the wave-function collapse is induced by the interaction of the system with a classical noise field, where the spatial correlation function of this noise is related to the Newtonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Objective-collapse Theory
Objective-collapse theories, also known as models of spontaneous wave function collapse or dynamical reduction models, are proposed solutions to the measurement problem, measurement problem in quantum mechanics. As with other theories called interpretations of quantum mechanics, they are possible explanations of why and how quantum measurements always give definite outcomes, not a superposition of them as predicted by the Schrödinger equation, and more generally how the classical world emerges from quantum theory. The fundamental idea is that the unitary evolution of the wave function describing the state of a quantum system is approximate. It works well for microscopic systems, but progressively loses its validity when the mass / complexity of the system increases. In collapse theories, the Schrödinger equation is supplemented with additional nonlinear and stochastic terms (spontaneous collapses) which localize the wave function in space. The resulting dynamics is such that for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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