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Reinventing Gravity
''Reinventing Gravity: A Scientist Goes Beyond Einstein'' is a science text by John W. Moffat, which explains his controversial theory of gravity. Moffat's theory Moffat's work culminates in his nonsymmetric gravitational theory and scalar–tensor–vector gravity (now called MOG). His theory explains galactic rotation curves without invoking dark matter. He proposes a variable speed of light approach to cosmological problems, which posits that '' G''/''c'' is constant through time, but ''G'' and ''c'' separately have not been. Moreover, the speed of light ''c'' may have been much higher (at least trillion trillion times faster than the normal speed of light) during early moments of the Big Bang. His recent work on inhomogeneous cosmological models purports to explain certain anomalous effects in the CMB data, and to account for the recently discovered acceleration of the expansion of the universe. The theory is based on an action principle and postulates the existence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Moffat (physicist)
John W. Moffat (born 24 May 1932) is a Danish-born Canadian physicist. He is currently professor emeritus of physics at the University of Toronto and is also an adjunct professor of physics at the University of Waterloo and a resident affiliate member of the Perimeter Institute for Theoretical Physics. Moffat is best known for his work on gravity and cosmology, culminating in his nonsymmetric gravitational theory and scalar–tensor–vector gravity (now called MOG), and summarized in his 2008 book for general readers, ''Reinventing Gravity''. His theory explains galactic rotation curves without invoking dark matter. He proposes a variable speed of light approach to cosmological problems. The speed of light ''c'' may have been more than 15 orders of magnitude higher during the early moments of the Big Bang. His recent work on inhomogeneous cosmological models purports to explain certain anomalous effects in the CMB data, and to account for the recently discovered accelerati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Action Principle
In physics, action is a scalar quantity that describes how the balance of kinetic versus potential energy of a physical system changes with trajectory. Action is significant because it is an input to the principle of stationary action, an approach to classical mechanics that is simpler for multiple objects. Action and the variational principle are used in Feynman's formulation of quantum mechanics and in general relativity. For systems with small values of action close to the Planck constant, quantum effects are significant. In the simple case of a single particle moving with a constant velocity (thereby undergoing uniform linear motion), the action is the momentum of the particle times the distance it moves, added up along its path; equivalently, action is the difference between the particle's kinetic energy and its potential energy, times the duration for which it has that amount of energy. More formally, action is a mathematical functional which takes the trajectory (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theories Of Gravity
A theory is a systematic and rational form of abstract thinking about a phenomenon, or the conclusions derived from such thinking. It involves contemplative and logical reasoning, often supported by processes such as observation, experimentation, and research. Theories can be scientific, falling within the realm of empirical and testable knowledge, or they may belong to non-scientific disciplines, such as philosophy, art, or sociology. In some cases, theories may exist independently of any formal discipline. In modern science, the term "theory" refers to scientific theories, a well-confirmed type of explanation of nature, made in a way consistent with the scientific method, and fulfilling the criteria required by modern science. Such theories are described in such a way that scientific tests should be able to provide empirical support for it, or empirical contradiction (" falsify") of it. Scientific theories are the most reliable, rigorous, and comprehensive form of scientific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Popular Physics Books
Popularity or social status is the quality of being well liked, admired or well known to a particular group. Popular may also refer to: In sociology * Popular culture * Popular fiction * Popular music Popular music is music with wide appeal that is typically distributed to large audiences through the music industry. These forms and styles can be enjoyed and performed by people with little or no musical training.Popular Music. (2015). ''Fun ... * Popular science * Populace, the total population of a certain place ** Populism, a political philosophy, based on the idea that the common people are being exploited. * Informal usage or custom, as in popular names, as opposed to formal or scientific nomenclature Companies * Popular, Inc., also known as ''Banco Popular'', a financial services company * Popular Holdings, a Singapore-based educational book company * The Popular (department store), a chain of department stores in El Paso, Texas, from 1902 to 1995 Med ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Einstein Wrote Back
''Einstein Wrote Back'' is a memoir by Canadian physicist John Moffat that documents his encounters with various other famous physicists, including Niels Bohr, Albert Einstein, Erwin Schrödinger, Fred Hoyle, Wolfgang Pauli, Paul Dirac, Abdus Salam, and J. Robert Oppenheimer, as well as his work at Imperial College London, Princeton University, CERN, and the University of Toronto. The book's title comes from a series of letters Moffat exchanged with Einstein early in his life, which inspired Moffat to continue studying physics. Reception Writing in ''Physics World'', Graham Farmelo described the book as a pleasant read, though some of the anecdotes appeared embellished and historical details were inconsistent. See also *''Reinventing Gravity ''Reinventing Gravity: A Scientist Goes Beyond Einstein'' is a science text by John W. Moffat, which explains his controversial theory of gravity. Moffat's theory Moffat's work culminates in his nonsymmetric gravitational theory an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Publishers Weekly
''Publishers Weekly'' (''PW'') is an American weekly trade news magazine targeted at publishers, librarians, booksellers, and literary agents. Published continuously since 1872, it has carried the tagline, "The International News Magazine of Book Publishing and Bookselling." With 51 issues a year, the emphasis today is on book reviews. History Nineteenth century The magazine was founded by bibliographer Frederick Leypoldt in the late 1860s and had various titles until Leypoldt settled on the name ''The Publishers' Weekly'' (with an apostrophe) in 1872. The publication was a compilation of information about newly published books, collected from publishers and from other sources by Leypoldt, for an audience of booksellers. By 1876, ''The Publishers' Weekly'' was being read by nine tenths of the booksellers in the country. In 1878, Leypoldt sold ''The Publishers' Weekly'' to his friend Richard Rogers Bowker, in order to free up time for his other bibliographic endeavors. Augu ... [...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 made available free of cost 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 film ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EE Times
''EE Times'' (''Electronic Engineering Times'') is an electronics industry magazine published in the United States since 1972. EE Times is currently owned by AspenCore, a division of Arrow Electronics since August 2016. Ownership and status ''EE Times'' was launched in 1972 by Gerard G. Leeds of CMP Publications Inc. In 1999, the Leeds family sold CMP to United Business Media for $900 million. After 2000, ''EE Times'' moved more into web publishing. The shift in advertising from print to online began to accelerate in 2007, and the periodical shed staff to adjust to the downturn in revenue. In July 2013, the digital edition migrated to UBM TechWeb's DeusM community platform. On June 3, 2016, UBM announced that ''EE Times'', along with the rest of its electronics media portfolio ( EDN, Embedded.com, TechOnline, and Datasheets.com), was being sold to AspenCore Media, a company owned by Arrow Electronics, for $23.5 million. The acquisition was completed on August 1, 2016. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fifth Force
In physics, a fifth force refers to a hypothetical fundamental interaction (also known as fundamental force) beyond the four known interactions in nature: gravitational, electromagnetic, strong nuclear, and weak nuclear forces. Some speculative theories have proposed a fifth force to explain various anomalous observations that do not fit existing theories. The specific characteristics of a putative fifth force depend on which hypothesis is being advanced. No evidence to support these models has been found. The term is also used as "the Fifth force" when referring to a specific theory advanced by Ephraim Fischbach in 1971 to explain experimental deviations in the theory of gravity. Later analysis failed to reproduce those deviations. History The term fifth force originates in a 1986 paper by Ephraim Fischbach et al. who reanalyzed the data from the Eötvös experiment of Loránd Eötvös from earlier in the century; the reanalysis found a distance dependence to gravity th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yukawa Potential
Yukawa (written: 湯川) is a Japanese surname, but is also applied to proper nouns. People * Diana Yukawa (born 1985), Anglo-Japanese solo violinist. She has had two solo albums with BMG Japan, one of which opened to #1 * Hideki Yukawa (1907–1981), Japanese theoretical physicist and the first Japanese Nobel laureate * Kazuyuki Yukawa (1949–2025), Japanese politician * Morio Yukawa (1908–1988), Japanese economist and diplomat * Tsutomu Yukawa (1911–1942), Japanese aikidoka * Yasutoshi Yukawa (1941–2014), Japanese linguist Fictional characters Places * Yukawa Institute for Theoretical Physics, a research institute in the field of theoretical physics, attached to Kyoto University in Japan * Yukawa Station, a train station in Nachikatsuura, Higashimuro District, Wakayama Prefecture, Japan Other * Yukawa interaction, named after Hideki Yukawa, is an interaction between a scalar field φ and a Dirac field Ψ of a particular type * Yukawa potential, a potential of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weak-field Approximation
In the theory of general relativity, linearized gravity is the application of perturbation theory to the metric tensor that describes the geometry of spacetime. As a consequence, linearized gravity is an effective method for modeling the effects of gravity when the gravitational field is weak. The usage of linearized gravity is integral to the study of gravitational waves and weak-field gravitational lensing. Weak-field approximation The Einstein field equation (EFE) describing the geometry of spacetime is given as : R_ - \fracRg_ = \kappa T_ where R_ is the Ricci tensor, R is the Ricci scalar, T_ is the energy–momentum tensor, \kappa = 8 \pi G / c^4 is the Einstein gravitational constant, and g_ is the spacetime metric tensor that represents the solutions of the equation. Although succinct when written out using Einstein notation, hidden within the Ricci tensor and Ricci scalar are exceptionally nonlinear dependencies on the metric tensor that render the prospect of finding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalar Fields
Scalar may refer to: *Scalar (mathematics), an element of a field, which is used to define a vector space, usually the field of real numbers *Scalar (physics), a physical quantity that can be described by a single element of a number field such as a real number **Lorentz scalar, a quantity in the theory of relativity which is invariant under a Lorentz transformation **Pseudoscalar, a quantity that behaves like a scalar, except that it changes sign under a parity inversion *Scalar (computing), any non-composite value *Scalar boson, in physics, a boson subatomic particle whose spin equals zero See also *dot product, also known as scalar product *dimensionless quantity, also known as scalar quantity *Inner product space *Scalar field *Scale (music) *Scaler (other) *''Pterophyllum scalare'' (Lichtenstein, 1823), a species of freshwater angelfish * Scala (other) Scala or SCALA may refer to: Automobiles * Renault Scala, multiple automobile models * Škoda Scala, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |