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Peter Woit
Peter Woit (; born September 11, 1957) is an American theoretical physicist. He is a senior lecturer in the Mathematics department at Columbia University. Woit, a critic of string theory, has published a book ''Not Even Wrong'' (2006) and writes a blog of the same name. Career Woit graduated in 1979 from Harvard University with bachelor's and master's degrees in physics. He obtained his PhD in particle physics from Princeton University in 1985, followed by postdoctoral work in theoretical physics at State University of New York at Stony Brook and mathematics at the Mathematical Sciences Research Institute (MSRI) in Berkeley. He spent four years as an assistant professor at Columbia. He now holds a permanent position in the mathematics department, as senior lecturer and as departmental computer administrator. Woit is a U.S. citizen and also has a Latvian passport. His father was born in Riga and became exiled with his own parents at the beginning of the Soviet occupation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theoretical Physics
Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain and predict natural phenomena. This is in contrast to experimental physics, which uses experimental tools to probe these phenomena. The advancement of science generally depends on the interplay between experimental studies and theory. In some cases, theoretical physics adheres to standards of mathematical rigour while giving little weight to experiments and observations.There is some debate as to whether or not theoretical physics uses mathematics to build intuition and illustrativeness to extract physical insight (especially when normal experience fails), rather than as a tool in formalizing theories. This links to the question of it using mathematics in a less formally rigorous, and more intuitive or heuristic way than, say, mathematical physics. For example, while developing special relativity, Albert Einstein was concerned with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupation Of Latvia
Latvia has been occupied by military forces from other nations from time to time. Military occupations of Latvia have included: * Livonian Crusade (13th century) * Soviet occupation of Latvia in 1940 * Occupation of Latvia by Nazi Germany (1941–1945) * Soviet re-occupation of Latvia in 1944 * Latvian Soviet Socialist Republic (21 July 1940 – 21 August 1991) See also * Baltic states under Soviet rule (1944–1991) * German occupation of the Baltic states during World War II * Museum of the Occupation of Latvia * Occupation of the Baltic states * Soviet occupation of the Baltic states (1940) * Soviet re-occupation of the Baltic states (1944) The Soviet Union (USSR) occupied most of the territory of the Baltic states in its 1944 Baltic Offensive during World War II. Dear (2001). p. 85. The Red Army regained control over the three Baltic capitals and encircled retreating Wehrmacht a ... {{years in Latvia Military occupations Military occupations Military history ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lee Smolin
Lee Smolin (; born June 6, 1955) is an American theoretical physicist, a faculty member at the Perimeter Institute for Theoretical Physics, an adjunct professor of physics at the University of Waterloo and a member of the graduate faculty of the philosophy department at the University of Toronto. Smolin's 2006 book '' The Trouble with Physics'' criticized string theory as a viable scientific theory. He has made contributions to quantum gravity theory, in particular the approach known as loop quantum gravity. He advocates that the two primary approaches to quantum gravity, loop quantum gravity and string theory, can be reconciled as different aspects of the same underlying theory. He also advocates an alternative view on space and time he calls temporal naturalism. His research interests also include cosmology, elementary particle theory, the foundations of quantum mechanics, and theoretical biology. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kavli Institute For Theoretical Physics
The Kavli Institute for Theoretical Physics (KITP) is a research institute of the University of California, Santa Barbara. KITP is one of the most renowned institutes for theoretical physics in the world, and brings theorists in physics and related fields together to work on topics at the forefront of theoretical science. The National Science Foundation has been the principal supporter of the institute since it was founded as the Institute for Theoretical Physics in 1979. In a 2007 article in the ''Proceedings of the National Academy of Sciences'', KITP was given the highest impact index in a comparison of nonbiomedical research organizations across the U.S. About In the early 2000s, the institute, formerly known as the Institute for Theoretical Physics, or ITP, was named for the Norwegian-American physicist and businessman Fred Kavli, in recognition of his donation of $7.5 million to the institute. Kohn Hall, which houses KITP, is located just beyond the Henley Gate at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of California, Santa Barbara
The University of California, Santa Barbara (UC Santa Barbara or UCSB) is a public land-grant research university in Santa Barbara, California with 23,196 undergraduates and 2,983 graduate students enrolled in 2021–2022. It is part of the University of California 10-university system. Tracing its roots back to 1891 as an independent teachers' college, UCSB joined the University of California system in 1944, and is the third-oldest undergraduate campus in the system, after UC Berkeley and UCLA. Located on a WWII-era Marine air station, UC Santa Barbara is organized into three undergraduate colleges ( College of Letters and Science, College of Engineering, College of Creative Studies) and two graduate schools ( Gevirtz Graduate School of Education and Bren School of Environmental Science & Management), offering more than 200 degrees and programs. The university has 10 national research centers, including the Kavli Institute for Theoretical Physics and the Center for Control, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perturbation Theory (quantum Mechanics)
In quantum mechanics, perturbation theory is a set of approximation schemes directly related to mathematical perturbation for describing a complicated quantum system in terms of a simpler one. The idea is to start with a simple system for which a mathematical solution is known, and add an additional "perturbing" Hamiltonian representing a weak disturbance to the system. If the disturbance is not too large, the various physical quantities associated with the perturbed system (e.g. its energy levels and eigenstates) can be expressed as "corrections" to those of the simple system. These corrections, being small compared to the size of the quantities themselves, can be calculated using approximate methods such as asymptotic series. The complicated system can therefore be studied based on knowledge of the simpler one. In effect, it is describing a complicated unsolved system using a simple, solvable system. Approximate Hamiltonians Perturbation theory is an important tool f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vacuum State
In quantum field theory, the quantum vacuum state (also called the quantum vacuum or vacuum state) is the quantum state with the lowest possible energy. Generally, it contains no physical particles. The word zero-point field is sometimes used as a synonym for the vacuum state of a quantized field which is completely individual. According to present-day understanding of what is called the vacuum state or the quantum vacuum, it is "by no means a simple empty space". According to quantum mechanics, the vacuum state is not truly empty but instead contains fleeting electromagnetic waves and particles that pop into and out of the quantum field. The QED vacuum of quantum electrodynamics (or QED) was the first vacuum of quantum field theory to be developed. QED originated in the 1930s, and in the late 1940s and early 1950s it was reformulated by Feynman, Tomonaga, and Schwinger, who jointly received the Nobel prize for this work in 1965. For a historical discussion, see for e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-theory
M-theory is a theory in physics that unifies all consistent versions of superstring theory. Edward Witten first conjectured the existence of such a theory at a string theory conference at the University of Southern California in 1995. Witten's announcement initiated a flurry of research activity known as the second superstring revolution. Prior to Witten's announcement, string theorists had identified five versions of superstring theory. Although these theories initially appeared to be very different, work by many physicists showed that the theories were related in intricate and nontrivial ways. Physicists found that apparently distinct theories could be unified by mathematical transformations called S-duality and T-duality. Witten's conjecture was based in part on the existence of these dualities and in part on the relationship of the string theories to a field theory called eleven-dimensional supergravity. Although a complete formulation of M-theory is not known, such a form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degrees Of Freedom (physics And Chemistry)
In physics and chemistry, a degree of freedom is an independent physical parameter in the formal description of the state of a physical system. The set of all states of a system is known as the system's phase space, and the degrees of freedom of the system are the dimensions of the phase space. The location of a particle in three-dimensional space requires three position coordinates. Similarly, the direction and speed at which a particle moves can be described in terms of three velocity components, each in reference to the three dimensions of space. If the time evolution of the system is deterministic (where the state at one instant uniquely determines its past and future position and velocity as a function of time) such a system has six degrees of freedom. If the motion of the particle is constrained to a lower number of dimensions – for example, the particle must move along a wire or on a fixed surface – then the system has fewer than six degrees of freedom. On the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supersymmetric
In a supersymmetric theory the equations for force and the equations for matter are identical. In theoretical and mathematical physics, any theory with this property has the principle of supersymmetry (SUSY). Dozens of supersymmetric theories exist. Supersymmetry is a spacetime symmetry between two basic classes of particles: bosons, which have an integer-valued spin and follow Bose–Einstein statistics, and fermions, which have a half-integer-valued spin and follow Fermi–Dirac statistics. In supersymmetry, each particle from one class would have an associated particle in the other, known as its superpartner, the spin of which differs by a half-integer. For example, if the electron exists in a supersymmetric theory, then there would be a particle called a ''"selectron"'' (superpartner electron), a bosonic partner of the electron. In the simplest supersymmetry theories, with perfectly " unbroken" supersymmetry, each pair of superpartners would share the same mass and inter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 vicinity of black holes or similar compact astrophysical objects, such as neutron stars. Three of the four fundamental forces of physics are described within the framework of quantum mechanics and quantum field theory. The current understanding of the fourth force, gravity, is based on Albert Einstein's general theory of relativity, which is formulated within the entirely different framework of classical physics. However, that description is incomplete: describing the gravitational field of a black hole in the general theory of relativity leads physical quantities, such as the spacetime curvature, to diverge at the center of the black hole. This signals the breakdown of the general theory of relativity and the need for a theory that goe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
