Brian Greene
Brian Randolph Greene (born February 9, 1963) is a American theoretical physicist, mathematician, and string theorist. Greene was a physics professor at Cornell University from 19901995, and has been a professor at Columbia University since 1996 and chairman of the World Science Festival since co-founding it in 2008. Greene has worked on Mirror symmetry (string theory), mirror symmetry, relating two different Calabi–Yau manifolds (concretely relating the conifold to one of its orbifolds). He also described the Flop-transition, flop transition, a mild form of topology change, showing that topology in string theory can change at the conifold point. Greene has become known to a wider audience through his books for the general public, ''The Elegant Universe'', ''Icarus at the Edge of Time'', ''The Fabric of the Cosmos'', ''The Hidden Reality'', and related Public Broadcasting Service, PBS television specials. He also appeared on ''The Big Bang Theory'' episode "The Big Bang Th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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New York City
New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the List of United States cities by population density, most densely populated major city in the United States, and is more than twice as populous as second-place Los Angeles. New York City lies at the southern tip of New York (state), New York State, and constitutes the geographical and demographic center of both the Northeast megalopolis and the New York metropolitan area, the largest metropolitan area in the world by urban area, urban landmass. With over 20.1 million people in its metropolitan statistical area and 23.5 million in its combined statistical area as of 2020, New York is one of the world's most populous Megacity, megacities, and over 58 million people live within of the city. New York City is a global city, global Culture of New ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Super-string Theory
Superstring theory is an attempt to explain all of the particles and fundamental forces of nature in one theory by modeling them as vibrations of tiny supersymmetric strings. 'Superstring theory' is a shorthand for supersymmetric string theory because unlike bosonic string theory, it is the version of string theory that accounts for both fermions and bosons and incorporates supersymmetry to model gravity. Since the second superstring revolution, the five superstring theories are regarded as different limits of a single theory tentatively called M-theory. Background The deepest problem in theoretical physics is harmonizing the theory of general relativity, which describes gravitation and applies to large-scale structures (stars, galaxies, super clusters), with quantum mechanics, which describes the other three fundamental forces acting on the atomic scale. The development of a quantum field theory of a force invariably results in infinite possibilities. Physicists developed t ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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The Big Bang Theory (season 4)
The fourth season of the American sitcom ''The Big Bang Theory'' began airing on CBS on September 23, 2010. Melissa Rauch and Mayim Bialik auditioned and were promoted to the main cast during this season as Dr. List of The Big Bang Theory characters#Bernadette Maryann Rostenkowski-Wolowitz, Bernadette Rostenkowski and Amy Farrah Fowler, Dr. Amy Farrah Fowler respectively. Johnny Galecki received a nomination for the Primetime Emmy Award for Outstanding Lead Actor in a Comedy Series at the 63rd Primetime Emmy Awards for the episode "The Big Bang Theory (season 4)#ep78, The Benefactor Factor". Jim Parsons won the same award for the episode "The Big Bang Theory (season 4)#ep84, The Agreement Dissection". Production During the season, Kaley Cuoco's character Penny was absent from episodes 5 and 6 after she fell off a horse and the horse broke her leg. When returning to the series, she was shown working as a bartender instead of waiter, waitressing at her usual workplace, The Cheesec ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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The Big Bang Theory
''The Big Bang Theory'' is an American television sitcom created by Chuck Lorre and Bill Prady, both of whom served as executive producers on the series, along with Steven Molaro, all of whom also served as head writers. It premiered on CBS on September 24, 2007, and concluded on May 16, 2019, having broadcast 279 episodes over 12 seasons. The show originally centered on five characters living in Pasadena, California: Leonard Hofstadter (Johnny Galecki) and Sheldon Cooper (Jim Parsons), both physicists at Caltech, who share an apartment; Penny (The Big Bang Theory), Penny (Kaley Cuoco), a waitress and aspiring actress who lives across the hall; and Leonard and Sheldon's similarly geeky and socially awkward friends and coworkers, aerospace engineer Howard Wolowitz (Simon Helberg) and astrophysicist Raj Koothrappali (Kunal Nayyar). Over time, supporting characters were promoted to starring roles, including neuroscientist Amy Farrah Fowler (Mayim Bialik), microbiologist Bernadet ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Public Broadcasting Service
The Public Broadcasting Service (PBS) is an American public broadcaster and non-commercial, free-to-air television network based in Arlington, Virginia. PBS is a publicly funded nonprofit organization and the most prominent provider of educational programming to public television stations in the United States, distributing shows such as ''Frontline'', '' Nova'', ''PBS NewsHour'', ''Sesame Street'', and ''This Old House''. PBS is funded by a combination of member station dues, the Corporation for Public Broadcasting, pledge drives, and donations from both private foundations and individual citizens. All proposed funding for programming is subject to a set of standards to ensure the program is free of influence from the funding source. PBS has over 350 member television stations, many owned by educational institutions, nonprofit groups both independent or affiliated with one particular local public school district or collegiate educational institution, or entities owned by or r ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Icarus At The Edge Of Time
''Icarus at the Edge of Time'' is a 2008 children's book written by the physicist Brian Greene and illustrated by Chip Kidd with images from the Hubble Space Telescope. Plot introduction The book is a science fiction retelling of Icarus' tale. It is about a young man who runs away from his traveling, deep-space home to explore a black hole. Reception ''Publishers Weekly'' review said, "Attractive on the shelf as both contemporary and science-focused, it is exactly what the author is trying to accomplish with his re-told fable, as well as a fine treatment of already beautiful imagery; not a lot of pushing and pulling is needed." A Trashotron review said, "fiction space opera as well as a new kind of children's book. It really does hold up with an appeal for anyone who is interested in science, storytelling or fathers and sons. That might add up to a sizable audience. They'll be well-rewarded, and it's good that the book can withstand multiple readings. It will get read and re-rea ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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String Theory
In physics, string theory is a theoretical framework in which the point-like particles of particle physics are replaced by one-dimensional objects called strings. String theory describes how these strings propagate through space and interact with each other. On distance scales larger than the string scale, a string looks just like an ordinary particle, with its mass, charge, and other properties determined by the vibrational state of the string. In string theory, one of the many vibrational states of the string corresponds to the graviton, a quantum mechanical particle that carries the gravitational force. Thus, string theory is a theory of quantum gravity. String theory is a broad and varied subject that attempts to address a number of deep questions of fundamental physics. String theory has contributed a number of advances to mathematical physics, which have been applied to a variety of problems in black hole physics, early universe cosmology, nuclear physics, and conde ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Topology
In mathematics, topology (from the Greek language, Greek words , and ) is concerned with the properties of a mathematical object, geometric object that are preserved under Continuous function, continuous Deformation theory, deformations, such as Stretch factor, stretching, Twist (mathematics), twisting, crumpling, and bending; that is, without closing holes, opening holes, tearing, gluing, or passing through itself. A topological space is a set (mathematics), set endowed with a structure, called a ''Topology (structure), topology'', which allows defining continuous deformation of subspaces, and, more generally, all kinds of continuity (mathematics), continuity. Euclidean spaces, and, more generally, metric spaces are examples of a topological space, as any distance or metric defines a topology. The deformations that are considered in topology are homeomorphisms and homotopy, homotopies. A property that is invariant under such deformations is a topological property. Basic exampl ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Flop-transition
In theoretical physics, particularly string theory and M-theory, the notion of a flop-transition is basically the shrinking of a sphere in a Calabi-Yau space to the point of tearing. Based on typical spacetime topology, this is not possible due to mathematical technicalities. On the other hand, mirror symmetry allows for the mathematical similarity between two distinct Calabi-Yau manifolds. If one undergoes a flop-transition, the mirror of it should result in identical mathematical properties, which it does. Definition If there is a given Calabi-Yau manifold (basically a space with 6 or more dimensions curled up in a special way) then a sphere in the center can shrink down to an infinitesimal point that resembles a singularity. After reaching the singularity-like point, the sphere tears and then a new sphere "blows up" to replace the torn one. The sphere in the mirror image (from Mirror symmetry) merely undergoes topologically smooth transition. The mathematical results from the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Orbifold
In the mathematical disciplines of topology and geometry, an orbifold (for "orbit-manifold") is a generalization of a manifold. Roughly speaking, an orbifold is a topological space which is locally a finite group quotient of a Euclidean space. Definitions of orbifold have been given several times: by Ichirô Satake in the context of automorphic forms in the 1950s under the name ''V-manifold''; by William Thurston in the context of the geometry of 3-manifolds in the 1970s when he coined the name ''orbifold'', after a vote by his students; and by André Haefliger in the 1980s in the context of Mikhail Gromov's programme on CAT(k) spaces under the name ''orbihedron''. Historically, orbifolds arose first as surfaces with singular points long before they were formally defined. One of the first classical examples arose in the theory of modular forms with the action of the modular group \mathrm(2,\Z) on the upper half-plane: a version of the Riemann–Roch theorem holds after the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Conifold
In mathematics and string theory, a conifold is a generalization of a manifold. Unlike manifolds, conifolds can contain conical singularities, i.e. points whose neighbourhoods look like cones over a certain base. In physics, in particular in flux compactifications of string theory, the base is usually a five-dimensional real manifold, since the typically considered conifolds are complex 3-dimensional (real 6-dimensional) spaces. Overview Conifolds are important objects in string theory: Brian Greene explains the physics of conifolds in Chapter 13 of his book ''The Elegant Universe''—including the fact that the space can tear near the cone, and its topology can change. This possibility was first noticed by and employed by to prove that conifolds provide a connection between all (then) known Calabi–Yau compactifications in string theory; this partially supports a conjecture by whereby conifolds connect all possible Calabi–Yau complex 3-dimensional spaces. A well-known ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Calabi–Yau Manifold
In algebraic geometry, a Calabi–Yau manifold, also known as a Calabi–Yau space, is a particular type of manifold which has properties, such as Ricci flatness, yielding applications in theoretical physics. Particularly in superstring theory, the extra dimensions of spacetime are sometimes conjectured to take the form of a 6-dimensional Calabi–Yau manifold, which led to the idea of mirror symmetry. Their name was coined by , after who first conjectured that such surfaces might exist, and who proved the Calabi conjecture. Calabi–Yau manifolds are complex manifolds that are generalizations of K3 surfaces in any number of complex dimensions (i.e. any even number of real dimensions). They were originally defined as compact Kähler manifolds with a vanishing first Chern class and a Ricci-flat metric, though many other similar but inequivalent definitions are sometimes used. Definitions The motivational definition given by Shing-Tung Yau is of a compact Kähl ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |