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Consistent Histories
In quantum mechanics, the consistent histories or simply "consistent quantum theory" interpretation generalizes the complementarity aspect of the conventional Copenhagen interpretation. The approach is sometimes called decoherent histories and in other work decoherent histories are more specialized. First proposed by Robert Griffiths in 1984, this interpretation of quantum mechanics is based on a consistency criterion that then allows probabilities to be assigned to various alternative histories of a system such that the probabilities for each history obey the rules of classical probability while being consistent with the Schrödinger equation. In contrast to some interpretations of quantum mechanics, the framework does not include "wavefunction collapse" as a relevant description of any physical process, and emphasizes that measurement theory is not a fundamental ingredient of quantum mechanics. Consistent histories allows predictions related to the state of the universe ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interpretation Of Quantum Mechanics
An interpretation of quantum mechanics is an attempt to explain how the mathematical theory of quantum mechanics might correspond to experienced reality. Quantum mechanics has held up to rigorous and extremely precise tests in an extraordinarily broad range of experiments. However, there exist a number of contending schools of thought over their interpretation. These views on interpretation differ on such fundamental questions as whether quantum mechanics is deterministic or stochastic, local or non-local, which elements of quantum mechanics can be considered real, and what the nature of measurement is, among other matters. While some variation of the Copenhagen interpretation is commonly presented in textbooks, many other interpretations have been developed. Despite nearly a century of debate and experiment, no consensus has been reached among physicists and philosophers of physics concerning which interpretation best "represents" reality. History The definition of quantum t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christopher Isham
Christopher Isham (; born 28 April 1944), usually cited as Chris J. Isham, is a theoretical physicist at Imperial College London. Research Isham's main research interests are quantum gravity and foundational studies in quantum theory. He was the inventor of an approach to temporal quantum logic called the HPO formalism, and has worked on loop quantum gravity and quantum geometrodynamics. Together with other physicists, such as John C. Baez, Isham is known as a proponent of the utility of category theory in theoretical physics. In recent years, since at least 1997, he has been working on a new approach to quantum theory based on topos theory. He is the author of ''Modern differential geometry for physicists'', first published in 1989. Isham has appeared in several '' NOVA'' television programmes as well as a film about Stephen Hawking. Physicist Paul Davies has described Isham as "Britain's greatest quantum gravity expert". As a practising Christian, Isham has also writte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HPO Formalism
The history projection operator (HPO) formalism is an approach to temporal quantum logic developed by Chris Isham. It deals with the logical structure of quantum mechanical propositions asserted at different points in time. Introduction In standard quantum mechanics a physical system is associated with a Hilbert space \mathcal. States of the system at a fixed time are represented by normalised vectors in the space and physical observables are represented by Hermitian operators on \mathcal. A physical proposition \,P about the system at a fixed time can be represented by an orthogonal projection operator \hat on \mathcal (See quantum logic). This representation links together the lattice operations in the lattice of logical propositions and the lattice of projection operators on a Hilbert space (See quantum logic). The HPO formalism is a natural extension of these ideas to propositions about the system that are concerned with more than one time. History propositions Homo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EPR Paradox
EPR may refer to: Science and technology * EPR (nuclear reactor), European Pressurised-Water Reactor * EPR paradox (Einstein–Podolsky–Rosen paradox), in physics * Earth potential rise, in electrical engineering * East Pacific Rise, a mid-oceanic ridge * Electron paramagnetic resonance * Engine pressure ratio, of a jet engine * Ethylene propylene rubber * Yevpatoria RT-70 radio telescope (Evpatoria planetary radar) * Bernays–Schönfinkel class or effectively propositional, in mathematical logic * WS-Addressing#Endpoint references, Endpoint references in Web addressing * Ethnic Power Relations, dataset of ethnic groups * ePrivacy Regulation (ePR), proposal for the regulation of various privacy-related topics, mostly in relation to electronic communications within the European Union Medicine * Enhanced permeability and retention effect, a controversial concept in cancer research * Emergency Preservation and Resuscitation, a medical procedure * Electronic patient record Environ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Philosophy
''Quantum Philosophy'' is a 2002 book by the physicist Roland Omnès, in which he aims to show the non-specialist reader how modern developments in quantum mechanics allow the recovery of our common sense view of the world. Book contents * Section I – a review of mathematics, epistemology and science from the classical to the early modern period. * Section II – a review of the ineluctable rise of formalism in mathematics and in fundamental physical science, which, Omnès argues, was not a choice, but was forced on researchers by the nature of the subject matter. * Section III – the central section of the book, in which the recovery of common sense, as outlined below, is presented. * Section IV – a short section of reflections on possible future steps. Brief summary of Omnès' central argument Omnès' project is not quite as it at first sounds. He is not trying to show that quantum mechanics itself can be understood in a common sense framework, quite the opposite. He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Hartle
James Burkett Hartle (August 17, 1939 – May 17, 2023) was an American theoretical physicist. He joined the faculty of the University of California, Santa Barbara in 1966, and was a member of the external faculty of the Santa Fe Institute. Hartle is known for his work in general relativity, astrophysics, and interpretation of quantum mechanics. Early life Hartle was born on August 17, 1939, in Baltimore to Anna Elizabeth Burkett and Charles James Hartle. He began as an engineering major upon entering Princeton, but switched to physics due to the influence of John Wheeler. Hartle completed his AB at Princeton University in 1960 and his Ph.D. in particle physics under Murray Gell-Mann in 1964. Work In collaboration with Gell-Mann and others, Hartle developed an alternative to the standard Copenhagen interpretation, more general and appropriate to quantum cosmology, based on consistent histories. With Dieter Brill in 1964, he discovered the Brill–Hartle geon, an approxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murray Gell-Mann
Murray Gell-Mann (; September 15, 1929 – May 24, 2019) was an American theoretical physicist who played a preeminent role in the development of the theory of elementary particles. Gell-Mann introduced the concept of quarks as the fundamental building blocks of the strongly interacting particles, and the renormalization group as a foundational element of quantum field theory and statistical mechanics. He played key roles in developing the concept of chirality in the theory of the weak interactions and spontaneous chiral symmetry breaking in the strong interactions, which controls the physics of the light mesons. In the 1970s he was a co-inventor of quantum chromodynamics (QCD) which explains the confinement of quarks in mesons and baryons and forms a large part of the Standard Model of elementary particles and forces. Murray Gell-Mann received the 1969 Nobel Prize in Physics for his work on the theory of elementary particles. Life and education Gell-Mann was bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert B
The name Robert is an ancient Germanic given name, from Proto-Germanic "fame" and "bright" (''Hrōþiberhtaz''). Compare Old Dutch ''Robrecht'' and Old High German ''Hrodebert'' (a compound of ''Hrōþ, Hruod'' () "fame, glory, honour, praise, renown, godlike" and ''berht'' "bright, light, shining"). It is the second most frequently used given name of ancient Germanic origin.Reaney & Wilson, 1997. ''Dictionary of English Surnames''. Oxford University Press. It is also in use Robert (surname), as a surname. Another commonly used form of the name is Rupert (name), Rupert. After becoming widely used in Continental Europe, the name entered England in its Old French form ''Robert'', where an Old English cognate form (''Hrēodbēorht'', ''Hrodberht'', ''Hrēodbēorð'', ''Hrœdbœrð'', ''Hrœdberð'', ''Hrōðberχtŕ'') had existed before the Norman Conquest. The feminine version is Roberta (given name), Roberta. The Italian, Portuguese, and Spanish form is Roberto (given name), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamiltonian (quantum Theory)
In quantum mechanics, the Hamiltonian of a system is an operator corresponding to the total energy of that system, including both kinetic energy and potential energy. Its spectrum, the system's ''energy spectrum'' or its set of ''energy eigenvalues'', is the set of possible outcomes obtainable from a measurement of the system's total energy. Due to its close relation to the energy spectrum and time-evolution of a system, it is of fundamental importance in most formulations of quantum theory. The Hamiltonian is named after William Rowan Hamilton, who developed a revolutionary reformulation of Newtonian mechanics, known as Hamiltonian mechanics, which was historically important to the development of quantum physics. Similar to vector notation, it is typically denoted by \hat, where the hat indicates that it is an operator. It can also be written as H or \check. Introduction The Hamiltonian of a system represents the total energy of the system; that is, the sum of the kineti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roland Omnès
Roland Omnès (18 February 1931 – 2 August 2022) was a French physicist and author of several books that aimed to give non-scientists the information required to understand quantum mechanics. Biography Omnès was Professor Emeritus of Theoretical Physics in the Faculté des Sciences at Orsay, at the Université Paris-Sud XI. He was instrumental in developing consistent histories and quantum decoherence approaches in quantum mechanics. He received the Paul-Langevin Prize in 1959. Omnès died in Saint-Rémy-lès-Chevreuse on 2 August 2022, at the age of 91. Philosophical work In his philosophical work (especially in '' Quantum Philosophy''), Omnès argues that: # "Until modern times, intuitive, rational thought was sufficient to describe the world; mathematics remained an adjunct, simply helping to make our intuitive descriptions more precise." # "In the late 19th and early 20th centuries, we arrived at a Fracture between common sense and our best descriptions of reality ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Decoherence
Quantum decoherence is the loss of quantum coherence. It involves generally a loss of information of a system to its environment. Quantum decoherence has been studied to understand how quantum systems convert to systems that can be explained by classical mechanics. Beginning out of attempts to extend the understanding of quantum mechanics, the theory has developed in several directions and experimental studies have confirmed some of the key issues. Quantum computing relies on quantum coherence and is one of the primary practical applications of the concept. Concept In quantum mechanics, physical systems are described by a mathematical representation called a quantum state. Probabilities for the outcomes of experiments upon a system are calculated by applying the Born rule to the quantum state describing that system. Quantum states are either ''pure'' or ''mixed''; pure states are also known as ''wavefunctions''. Assigning a pure state to a quantum system implies certai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axioms Of Probability
The standard probability axioms are the foundations of probability theory introduced by Russian mathematician Andrey Kolmogorov in 1933. These axioms remain central and have direct contributions to mathematics, the physical sciences, and real-world probability cases. There are several other (equivalent) approaches to formalising probability. Bayesians will often motivate the Kolmogorov axioms by invoking Cox's theorem or the Dutch book arguments instead. Kolmogorov axioms The assumptions as to setting up the axioms can be summarised as follows: Let (\Omega, F, P) be a measure space such that P(E) is the probability of some event E, and P(\Omega) = 1. Then (\Omega, F, P) is a probability space, with sample space \Omega, event space F and probability measure P. First axiom The probability of an event is a non-negative real number: :P(E)\in\mathbb, P(E)\geq 0 \qquad \forall E \in F where F is the event space. It follows (when combined with the second axiom) that P(E) is alw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
