It is called string theory this may help in your quest
String theory
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String theory
Superstring theory [hide]Theory
String theory
Superstrings
Bosonic string theory
M-theory (simplified)
Type I string · Type II string
Heterotic string
String field theory
Holographic principle
[show]Concepts
Strings · Branes
Calabi–Yau manifold
Kac–Moody algebra
D-brane
E8 Lie group
[show]Related Topics
Supersymmetry
Supergravity
Quantum gravity
[show]Scientists
Witten · Green · Schwarz · Polchinski · Kaku · others
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Interaction in the subatomic world: world lines of point-like particles in the Standard Model or a world sheet swept up by closed strings in string theoryString theory is an incomplete mathematical approach to theoretical physics, whose building blocks are one-dimensional extended objects called strings, rather than the zero-dimensional point particles that form the basis for the standard model of particle physics. By replacing the point-like particles with strings, an apparently consistent quantum theory of gravity emerges, which has not been achievable under quantum field theory. Usually, the term string theory includes a group of related superstring theories and a few related frameworks such as M-theory, which seeks to unite them all.
String theorists have not yet completely described these theories, or determined if or how these theories relate to the physical universe.[1] The elegance and flexibility of the approach, however, and a number of qualitative similarities with more traditional physical models, have led many physicists to suspect that such a connection is possible. In particular, string theory may be a way to "unify" the known natural forces (gravitational, electromagnetic, weak nuclear and strong nuclear) by describing them with the same set of equations, as described in the theory of everything. On the other hand, the models have been criticized for their inability, thus far, to provide any experimentally testable predictions.
Work on string theory is made difficult by the very complex mathematics involved, and the large number of forms that the theories can take depending on the arrangement of space and energy. Thus far, string theory strongly suggests the existence of ten or eleven (in M-theory)[2] spacetime dimensions, as opposed to the usual four (three spatial and one temporal) used in relativity theory; however, the theory can describe universes with four effective (observable) spacetime dimensions by a variety of methods.[3] The theories also appear to describe higher-dimensional objects than strings, called branes. Certain types of string theory have also been shown to be equivalent to certain types of more traditional gauge theory, and it is hoped that research in this direction will lead to new insights on quantum chromodynamics, the fundamental theory of the strong nuclear force.[4][5][6][7]
Contents [hide]
1 Overview
2 Basic properties
2.1 Worldsheet
2.2 Dualities
2.3 Extra dimensions
2.3.1 Number of dimensions
2.3.2 Compact dimensions
2.3.3 Brane-world scenario
2.3.4 Effect of the hidden dimensions
2.4 D-branes
2.5 Gauge Bosons and D-branes
3 Gauge-gravity duality
3.1 Description of the duality
3.2 Examples and intuition
3.3 Contact with experiment
4 Problems and controversy
5 History
6 Popular culture
7 See also
8 References
9 Further reading
9.1 Popular books and articles
9.2 Textbooks
10 External links
[edit] Overview
For more details on why it is hard to unite gravity and quantum physics, and on alternatives to string theory, see quantum gravity.
Matter is composed of atoms, which in turn are made from quarks and electrons. According to String theory, all such particles are actually tiny loops of vibrating string [8]. The idea behind all string theories is that each elementary "particle" is actually a string of a very small scale (possibly of the order of the Planck length) which vibrates at resonant frequencies specific to that type of particle.[9] Thus, any elementary particle should be thought of as a tiny vibrating object, rather than as a point. This object can vibrate in different modes (just as a guitar string can produce different notes), with every mode appearing as a different particle (electron, photon, etc.). Strings can split and combine, which would appear as particles emitting and absorbing other particles, presumably giving rise to the known interactions between particles.
Levels of magnification: Macroscopic level, molecular level, atomic level, subatomic level, string level.In addition to strings, this theory also includes objects of higher dimensions, such as D-branes and NS-branes. Furthermore, all string theories predict the existence of degrees of freedom which are usually described as extra dimensions. String theory is thought to include some 10, 11, or 26 dimensions, depending on the specific theory and on the point of view.
Interest in string theory is driven largely by the hope that it will prove to be a consistent theory of quantum gravity or even a theory of everything. It can also naturally describe interactions similar to electromagnetism and the other forces of nature. Superstring theories include fermions, the building blocks of matter, and incorporate supersymmetry, a conjectured (but unobserved) symmetry of nature. It is not yet known whether string theory will be able to describe a universe with the precise collection of forces and particles that is observed, nor how much freedom the theory allows to choose those details.
String theory as a whole has not yet made falsifiable predictions that would allow it to be experimentally tested, though various planned observations and experiments could confirm some essential aspects of the theory, such as supersymmetry and extra dimensions. In addition, the full theory is not yet understood. For example, the theory does not yet have a satisfactory definition outside of perturbation theory; the quantum mechanics of branes (higher dimensional objects than strings) is not understood; the behavior of string theory in cosmological settings (time-dependent backgrounds) is still being worked out; finally, the principle by which string theory selects its vacuum state is a hotly contested topic (see string theory landscape).
String theory is thought to be a certain limit of another, more fundamental theory — M-theory — which is only partly defined and is not well understood.[10]
[edit] Basic properties
String theory is formulated in terms of an action principle, either the Nambu-Goto action or the Polyakov action, which describes how strings move through space and time. Like springs with no external force applied, the strings tend to shrink, thus minimizing their potential energy, but conservation of energy prevents them from disappearing, and instead they oscillate. By applying the ideas of quantum mechanics to strings it is possible to deduce the different vibrational modes of strings, and that each vibrational state appears to be a different particle. The mass of each particle, and the fashion with which it can interact, are determined by the way the string vibrates — the string can vibrate in many different modes, just like a guitar string can produce different notes. The different modes, each corresponding to a different kind of particle, make up the "spectrum" of the theory.
Strings can split and combine, which would appear as particles emitting and absorbing other particles, presumably giving rise to the known interactions between particles.
String theory includes both open strings, which have two distinct endpoints, and closed strings, where the endpoints are joined to make a complete loop. The two types of string behave in slightly different ways, yielding two different spectra. For example, in most string theories, one of the closed string modes is the graviton, and one of the open string modes is the photon. Because the two ends of an open string can always meet and connect, forming a closed string, there are no string theories without closed strings.
The earliest string model — the bosonic string, which incorporated only bosons, describes — in low enough energies — a quantum gravity theory, which also includes (if open strings are incorporated as well) gauge fields such as the photon (or, more generally, any gauge theory). However, this model has problems. Most importantly, the theory has a fundamental instability, believed to result in the decay (at least partially) of space-time itself. Additionally, as the name implies, the spectrum of particles contains only bosons, particles which, like the photon, obey particular rules of behavior. Roughly speaking, bosons are the constituents of radiation, but not of matter, which is made of fermions. Investigating how a string theory may include fermions in its spectrum led to the invention of supersymmetry, a mathematical relation between bosons and fermions. String theories which include fermionic vibrations are now known as superstring theories; several different kinds have been described, but all are now thought to be different limits of M-theory.
While understanding the details of string and superstring theories requires considerable mathematical sophistication, some qualitative properties of quantum strings can be understood in a fairly intuitive fashion. For example, quantum strings have tension, much like regular strings made of twine; this tension is considered a fundamental parameter of the theory. The tension of a quantum string is closely related to its size. Consider a closed loop of string, left to move through space without external forces. Its tension will tend to contract it into a smaller and smaller loop. Classical intuition suggests that it might