FACTOID # 21: 15% of Army recruits from South Dakota are Native American, which is roughly the same percentage for female Army recruits in the state.
 
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Encyclopedia > Bosonic string theory

Bosonic string theory is the original version of string theory, developed in the late 1960s. Although it has many attractive features, it also predicts a particle called the tachyon possessing some unsettling properties, and it has no fermions. All of its particles are bosons, that determines the name. The physicists have also calculated that bosonic string theory requires 26 spacetime dimensions: 25 spatial dimensions and one dimension of time. String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects (strings) rather than the zero-dimensional points (particles) that are the basis of the Standard Model of particle physics. ... A tachyon (from the Greek ταχύς {takhús}, meaning swift) is a hypothetical particle that travels at superluminal velocity. ... Fermions, named after Enrico Fermi, are particles which form totally-antisymmetric composite quantum states. ... Boson (game) Bosons, named after Satyendra Nath Bose, are particles which form totally-symmetric composite quantum states. ...


In the early 1970s, supersymmetry was discovered in the context of string theory, and a new version of string theory called superstring theory (supersymmetric string theory) became the real focus. Nevertheless, bosonic string theory remains a very useful "toy model" to understand many general features of perturbative string theory, and string theory textbooks usually start with the bosonic string. The first volume of Polchinski's String Theory and Zwiebach's A First Course in String Theory are good examples. In particle physics, supersymmetry is a hypothetical symmetry that relates bosons and fermions. ... 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. ... In quantum mechanics, perturbation theory is a set of approximation schemes for describing a complicated quantum system in terms of a simpler one. ... Categories: Stub ...


See also Polyakov action, Nambu-Goto action In physics, the Polyakov action is the two-dimensional action of a conformal field theory describing the worldsheet of a string in string theory. ... The Nambu-Goto action is the simplest invariant action in bosonic string theory. ...


  Results from FactBites:
 
Superstring theory - Wikipedia, the free encyclopedia (950 words)
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 incorporates fermions and supersymmetry.
The graviton (the proposed messenger particle of the gravitational force), for example, is predicted by the theory to be a string with wave amplitude zero.
String theory - Wikipedia, the free encyclopedia (2656 words)
String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects (strings) rather than the zero-dimensional points (particles) that are the basis of the Standard Model of particle physics.
Bosonic string theory is formulated in terms of the Nambu-Goto action, a mathematical quantity which can be used to predict how strings move through space and time.
Since string theory may not be tested in the foreseeable future, some scientists have asked if it even deserves to be called a scientific theory: it is not yet a falsifiable theory in the sense of Popper.
  More results at FactBites »

 
 

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