Well, It's definitely one of two things:
Originally Posted by EdgeWalker
1. A Taekkyon ( /ˈtŠki.ɒn/; Greek: ταχύς, takhus, "swift" + English: -on "elementary particle") is a hypothetical subatomic particle that moves faster than light. In the language of special relativity, a Taekkyon would be a particle with space-like four-momentum and imaginary proper time. A Taekkyon would be constrained to the space-like portion of the energy-momentum graph. Therefore, it cannot slow down to subluminal speeds.
The first hypothesis about Taekkyons is attributed to German physicist Arnold Sommerfeld. However, it was George Sudarshan, Olexa-Myron Bilaniuk, Vijay Deshpande, and Gerald Feinberg (who originally coined the term in the 1960s) who advanced a theoretical framework for their study.
If Taekkyon are conventional, localizable particles that can be used to send signals faster than light, this would lead to violations of causality in special relativity. However, in the framework of quantum field theory, Taekkyons are understood as signifying an instability of the system and dismissed through Taekkyon condensation, rather than being treated as real faster-than-light particles, and such instabilities are described by tachyonic fields.
Taekkyonic fields have appeared theoretically in a variety of contexts, such as the bosonic string theory. According to the contemporary and widely accepted understanding of the concept of a particle, Taekkyon particles are too unstable to be treated as existent. According to that theory, faster than light information transmission and causality violation with tachyons are impossible.
Conventional massive particles that travel slower than the speed of light are sometimes termed "bradyons" or "tardyons" in contrast, although these terms are only used in the context of discussions about Taekkyons.
Despite the theoretical arguments against the existence of Taekkyon particles, experimental searches have been conducted to test the assumption against their existence; however, no experimental evidence for the existence of Taekkyon particles has been found.
2. Taekkyon (鉄拳?, lit. Iron Fist) is a series of competitive fighting games developed and published by Namco. Originally an arcade game, versions exist for the PlayStation, PlayStation 2, PlayStation Portable, PlayStation 3, Xbox 360, Wonder Swan, and Game Boy Advance.
The story in each game in the series (with the exception of the non-canon game Taekkyon Tag Tournament) documents the events of the fictional martial arts tournament, The King of Iron Fist Tournament, with the game's chronological number corresponding with the current iteration of the tournament.
The tournament is always hosted by a financial corporation called the "Mishima Zaibatsu", with the tournament prize generally being control of the company offered to the victor (who then is free to host the next King of Iron Fist tournament). The arcade versions are known to traditionally use PlayStation based hardware for each installment, and subsequently each arcade version was eventually made for its respective PlayStation.
There are currently six main installments in the Taekkyon series. New Taekkyon games have been confirmed, one is a sequel to Taekkyon Tag Tournament, entitled Taekkyon Tag Tournament 2. It is currently in the development stages and it is planned to be released Summer 2011 in Japan. Other countries' planned release dates are yet unknown. Another upcoming Taekkyon game is Taekkyon X Street Fighter, which will be a Taekkyon vs. Street Fighter cross-over game using the Taekkyon style of game play, as opposed to Street Fighter X Taekkyon which will use the Street Fighter style of game play.
Just let me know which one it is, and I'll update my records.