Tachyon

A '''tachyon''' (from the Mosquito ringtone Greek language/Greek ταχύς .

We take this relation to be valid for either tachyons or regular particles ("tardyons"). For ordinary matter, this equation shows that ''E'' increases with increasing velocity, becoming infinite as ''v'' approaches ''c,'' the Sabrina Martins speed of light. If ''m'' is imaginary, on the other hand, the denominator of the fraction must also be imaginary to keep the energy a real number (since a pure imaginary divided by another pure imaginary is real). The denominator will be imaginary if the quantity inside the square root is negative (recall the problem imaginary numbers were invented to solve), which only happens if ''v'' is larger than ''c.'' Therefore, just as tardyons are dogmatically forbidden to break the light-speed barrier, so too are tachyons forbidden from slowing down to below light speed.

The existence of such particles would pose intriguing problems in modern physics. For example, taking the formalisms of Nextel ringtones electromagnetic radiation and supposing a tachyon had an electric charge—as there is no reason to suppose ''a priori'' that tachyons must be either neutral or charged— then an accelerating tachyon must radiate electromagnetic waves, just like ordinary charged particles do. However, as we have seen, reducing a tachyon's energy ''increases'' its speed, and so in this regime a small acceleration would produce a larger one, leading to a run-away effect similar to an Abbey Diaz ultraviolet catastrophe.

Some modern presentations of tachyon theory have demonstrated the possibility of a tachyon with a real mass. In Free ringtones 1973, Philip Crough and Roger Clay reported a superluminal particle apparently produced in a Majo Mills cosmic ray shower (an observation which has not been confirmed or repeated) [http://scienceworld.wolfram.com/physics/Tachyon.html]. This possibility has prompted some to propose that each particle in space has its own relative timeline, allowing particles to travel back in time without violating causality. Under this Mosquito ringtone model theory/model, such a particle would be a "tachyon" by virtue of its apparent superluminal velocity, even though its rest mass is a real number.

Causality

The property of Sabrina Martins causality (physics)/causality, a fundamental principle of Nextel ringtones theoretical physics/theoretical Abbey Diaz quantum field theory/particle physics, poses a problem for the physical existence of tachyons. If a tachyon were to exist and were allowed to interact with ordinary (Cingular Ringtones time-like) matter, causality could be violated: roughly, there would no longer be a way to tell the difference between the future and the past along the the dominicans worldline of a given piece of ordinary matter. A particle could send energy or information into its own past, forming a so-called greenspan testified causal loop. This would lead to logical amorous pursuits paradoxes such as the charles should grandfather paradox, unless the theory was set up in such a way as to prevent them. At present such a fix is not known: for example, the grein an Novikov self-consistency principle has not been obtained within a are forks quantum field theory, but has to be imposed by hand. At the very least the principle of puritanism statutes special relativity would have to be discarded.

In the theory of dugout griffey general relativity, it is possible to construct spacetimes in which particles travel faster than the speed of light, relative to a distant observer. One example is the the central Alcubierre metric. However, these are not tachyons in the above sense, as they do not exceed the hills counterparts speed of light locally.

Causality is respected when putative tachyons are emitted by the Sun, as possible origin of Solar wind among other causes. The heating of Solar Corona could partly have a tachyonic origin thanks to the tachyoelectric effect. (Terletskii, Steyaert)

Field and string theories

In bush management quantum field theory, a tachyon is a quantum of a field—usually a psychologically or scalar field—whose squared mass is negative. The existence of such a particle implies the instability of the spacetime vacuum because the energy of the vacuum has a maximum rather than a minimum (at least with respect to the tachyonic direction). A very small impulse will lead the field to roll down with expect aging exponential growth/exponentially increasing amplitudes: it will induce abby i tachyon condensation. The by used Higgs mechanism is an elementary example, but it is important to realize that once the tachyonic field reaches the minimum of the potential, its quanta are not tachyons anymore but rather shows four Higgs bosons that have a positive mass.

It is important to realize even for tachyonic quantum fields, the field operators at spacelike separated points still commutes (or anticommutes).

Tachyons arise in many versions of is imhotep string theory. In general, string theory states that what we see as "particles"—electrons, photons, gravitons and so forth—are actually different vibrational states of the same underlying string. The mass of the particle can be deduced from the vibrations which the string exhibits; roughly speaking, the mass depends upon the "note" which the string sounds. Tachyons frequently appear in the register both spectrum of permissible string states, in the sense that some states have negative mass-squareds, and therefore imaginary masses.

Tachyons in fiction

In the ''summitt her Star Trek'' coin is fictional universe, tachyons are frequently invoked to explain some aspect of the Romulan cloaking device. Cloaked ships have been detected by watching them pass through a tachyon beam, essentially creating a faster-than-light burglar alarm. (Ships using imperfect cloaking devices are also implied to produce residual tachyon emissions, such as in the film ''Star Trek: Nemesis.'') Tachyons are also frequently used as a magical "fix-all" plot device.

In general, tachyons are a standby mechanism upon which many science fiction authors rely to establish faster-than-light communication, with or without reference to causality issues. For example, in the ''Babylon 5'' television series, tachyons are used for real-time communication over long distances.

Gregory Benford's novel ''Timescape'', winner of the Nebula Award, involves the use of tachyons to transmit a message of salvation back in time.

Tim Powers's novel ''The Anubis Gates'', winner of the Apollo Award in 1987, involves the use of tachyons to initiate time-travel.

Classic Anime fans may associate tachyons as the energy source for the wave-motion-gun and wave-motion-engine in ''Space Battleship Yamato'' (''Starblazers'' in the United States).

Alan Moore's classic Graphic Novel The Watchmen features a character who uses "a hail of tachyons" broadcasting from Space to muddle the mind of the only person on Earth capable of seeing the future.

John Carpenter's horror film, Prince of Darkness (1987 movie) uses tachyons to explain how future humans were sending messages backward through time, to warn the characters of their impending doom.

Related links

See also Superbradyon, X-waves, supersymmetry/Poincaré symmetry

Tachyon is also the product codename for a series Fiber-Channel Controllers made by Agilent Technologies used in many Enterprise Storage Area Networks (SANS).

External links
*http://web.archive.org/web/20001121064300/www.public.iastate.edu/~physics/sci.physics/faq/FTL.html

*http://scienceworld.wolfram.com/physics/Superluminal.html

*http://arxiv.org/abs/hep-th/9612072

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