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Measurement Problem
In quantum mechanics, the measurement problem is the problem of how, or whether, wave function collapse occurs. The inability to observe such a collapse directly has given rise to different interpretations of quantum mechanics and poses a key set of questions that each interpretation must answer. The wave function in quantum mechanics evolves deterministically according to the Schrödinger equation as a linear superposition of different states. However, actual measurements always find the physical system in a definite state. Any future evolution of the wave function is based on the state the system was discovered to be in when the measurement was made, meaning that the measurement "did something" to the system that is not obviously a consequence of Schrödinger evolution. The measurement problem is describing what that "something" is, how a superposition of many possible values becomes a single measured value. To express matters differently (paraphrasing Steven Weinberg), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Mechanics
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 ''Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryce DeWitt
Bryce Seligman DeWitt (January 8, 1923 – September 23, 2004), was an American theoretical physicist noted for his work in gravitation and quantum field theory. Life He was born Carl Bryce Seligman, but he and his three brothers, including the noted ichthyologist Hugh Hamilton DeWitt, added "DeWitt" from their mother's side of the family, at the urging of their father, in 1950. In the early-1970s, this change of name so angered Felix Bloch that he blocked DeWitt's appointment to Stanford University and DeWitt and his wife Cecile DeWitt-Morette, a mathematical physicist, accepted faculty positions at the University of Texas at Austin. DeWitt served in World War II as a naval aviator. He died September 23, 2004 from pancreatic cancer at the age of 81. He is buried in France, and was survived by his wife and four daughters. Work He pioneered work in the quantization of general relativity and, in particular, developed canonical quantum gravity, manifestly covariant methods ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Many-worlds Interpretation
The many-worlds interpretation (MWI) is an interpretation of quantum mechanics that 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, such as the Copenhagen interpretation, 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.Hugh Everettbr>Theory of the Universal Wavefunction Thesis, Princeton University, (1956, 1973), pp 1–140 Bryce DeWitt popularized the formulation and named it ''many-worlds'' in the 1970s. See also Cecile M. DeWitt, John A. Wheeler eds, The Everett–Wheeler Interpretation of Quantum Mechanics, ''Battelle Rencontres: 1967 Lectures in Mathematics and Physics'' (1968)Bryce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Everett
Hugh Everett III (; November 11, 1930 – July 19, 1982) was an American physicist who first proposed the many-worlds interpretation (MWI) of quantum physics, which he termed his "relative state" formulation. In contrast to the then-dominant Copenhagen interpretation, the MWI posits that the wave function never collapses and that all possibilities of a quantum superposition are objectively real. Discouraged by the scorn of other physicists for MWI, Everett ended his physics career after completing his PhD. Afterwards, he developed the use of generalized Lagrange multipliers for operations research and applied this commercially as a defense analyst and a consultant. In poor health later in life, he died at the age of 51 in 1982. He is the father of musician Mark Oliver Everett. Although largely disregarded until near the end of Everett's lifetime, the MWI received more credibility with the discovery of quantum decoherence in the 1970s and has received increased attention in recen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review A
''Physical Review A'' (also known as PRA) is a monthly peer-reviewed scientific journal published by the American Physical Society covering atomic, molecular, and optical physics and quantum information. the editor was Jan M. Rost (Max Planck Institute for the Physics of Complex Systems). History In 1893, the ''Physical Review'' was established at Cornell University. It was taken over by the American Physical Society (formed in 1899) in 1913. In 1970, ''Physical Review'' was subdivided into ''Physical Review A'', ''B'', ''C'', and ''D''. At that time section ''A'' was subtitled ''Physical Review A: General Physics''. In 1990 a process was started to split this journal into two, resulting in the creation of ''Physical Review E'' in 1993. Hence, in 1993, ''Physical Review A'' changed its statement of scope to ''Atomic, Molecular and Optical Physics.'' In January 2007, the section of ''Physical Review E'' that published papers on classical optics was merged into ''Physical Review ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Stewart Bell
John Stewart Bell FRS (28 July 1928 – 1 October 1990) was a physicist from Northern Ireland and the originator of Bell's theorem, an important theorem in quantum physics regarding hidden-variable theories. In 2022, the Nobel Prize in Physics was awarded to Alain Aspect, John Clauser, and Anton Zeilinger for work on Bell inequalities and the experimental validation of Bell's theorem. Biography Early life and work Bell was born in Belfast, Northern Ireland. When he was 11 years old, he decided to be a scientist, and at 16 graduated from Belfast Technical High School. Bell then attended the Queen's University of Belfast, where, in 1948, he obtained a bachelor's degree in experimental physics and, a year later, a bachelor's degree in mathematical physics. He went on to complete a Ph.D. in physics at the University of Birmingham in 1956, specialising in nuclear physics and quantum field theory. In 1954, he married Mary Ross, also a physicist, whom he had met while working ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stanford Encyclopedia Of Philosophy
The ''Stanford Encyclopedia of Philosophy'' (''SEP'') combines an online encyclopedia of philosophy with peer-reviewed publication of original papers in philosophy, freely accessible to Internet users. It is maintained by Stanford University. Each entry is written and maintained by an expert in the field, including professors from many academic institutions worldwide. Authors contributing to the encyclopedia give Stanford University the permission to publish the articles, but retain the copyright to those articles. Approach and history As of August 5th, 2022, the ''SEP'' has 1,774 published entries. Apart from its online status, the encyclopedia uses the traditional academic approach of most encyclopedias and academic journals to achieve quality by means of specialist authors selected by an editor or an editorial committee that is competent (although not necessarily considered specialists) in the field covered by the encyclopedia and peer review. The encyclopedia was created in 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics World
''Physics World'' is the membership magazine of the Institute of Physics, one of the largest physical societies in the world. It is an international monthly magazine covering all areas of physics, pure and applied, and is aimed at physicists in research, industry, physics outreach, and education worldwide. Overview The magazine was launched in 1988 by IOP Publishing Ltd, under the founding editorship of Philip Campbell. The magazine is sent free to members of the Institute of Physics, who can access a digital edition of the magazine; selected articles can be read by anyone for free online. It was redesigned in September 2005 and has an audited circulation of just under 35000. The current editor is Matin Durrani. Others on the team are Michael Banks (news editor) and Tushna Commissariat and Sarah Teah (features editors). Hamish Johnston, Margaret Harris and Tami Freeman are online editors. Alongside the print and online magazine, Physics World produces films and two podcasts. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The European Physical Journal D
{{Infobox Journal , title = European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics , cover = Epjd webcover.jpg , editor = A. Beige, S. Ptasinska and A.V. Solov'yov , discipline = Atomic Physics , language = English , abbreviation = Eur. Phys. J. D , publisher = Springer Science+Business Media, EDP Sciences, Società Italiana di Fisica , frequency = Monthly , history = 1998–present , openaccess = , impact = 1.425 , impact-year = 2020 , website = https://epjd.epj.org/ , link1 = , link1-name = , link2 = , link2-name = , RSS = , atom = , JSTOR = , OCLC = , LCCN = , CODEN = , ISSN = 1434-6060 , eISSN = 1434-6079 The ''European Physical Journal D: Atomic, Molecular, Optical and Plasma Physics'' is an academic journal recognized by the European Physical Society, presenting new and original research results. S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philosophy Of Science (journal)
''Philosophy of Science'' is dedicated to the furthering of studies and free discussion from diverse standpoints in the philosophy of science. It is a peer-reviewed academic journal. Official affiliations In January 1934 ''Philosophy of Science'' announced itself as the chief external expression of the Philosophy of Science Association, which seems to have been the expectation of its founder, William Malisoff. The journal is currently the official journal of the Association, which Philipp Frank and C. West Churchman formally constituted in December 1947. Publication history Malisoff, who was independently wealthy, seems to have financed the launch of ''Philosophy of Science''. Correspondingly he became its first editor. In the first issue he sought papers ranging from studies on "the analysis of meaning, definition, symbolism," in scientific theories to those on "the nature and formulation of theoretical principles" and "in the function and significance of science within various ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Werner Heisenberg
Werner Karl Heisenberg () (5 December 1901 – 1 February 1976) was a German theoretical physicist and one of the main pioneers of the theory of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent series of papers with Max Born and Pascual Jordan, during the same year, his matrix formulation of quantum mechanics was substantially elaborated. He is known for the uncertainty principle, which he published in 1927. Heisenberg was awarded the 1932 Nobel Prize in Physics "for the creation of quantum mechanics". Heisenberg also made contributions to the theories of the hydrodynamics of turbulent flows, the atomic nucleus, ferromagnetism, cosmic rays, and subatomic particles. He was a principal scientist in the German nuclear weapons program during World War II. He was also instrumental in planning the first West German nuclear reactor at Karlsruhe, together with a research reactor in Munich, in 1957. Following World War II, he was appointed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
