Tachyon
| Classification | Elementary particle |
|---|---|
| Status | Hypothetical |
| Theorized | 1967 |
A tachyon (/ˈtækiɒn/) or tachyonic particle is a hypothetical particle that always travels faster than light. Physicists posit that faster-than-light particles cannot exist because they are inconsistent with the known laws of physics.[1][2] If such particles did exist they perhaps could be used to send signals faster than light and into the past. According to the theory of relativity this would violate causality, leading to logical paradoxes such as the grandfather paradox.[1] Tachyons would exhibit the unusual property of increasing in speed as their energy decreases, and would require infinite energy to slow to the speed of light. No verifiable experimental evidence for the existence of such particles has been found.
The term "tachyon" derives from a 1967 paper by Gerald Feinberg about excitations of a quantum field with imaginary mass. Subsequent work has shown the excitations are not faster than light particles but particle physicists still discuss "tachyons", e.g. in tachyon condensation, when they are referring to tachyonic fields.
- ^ a b Cite error: The named reference
Tiplerwas invoked but never defined (see the help page). - ^ Randall, Lisa (2005). Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions. Harper Collins. p. 286. ISBN 9780060531089.
People initially thought of tachyons as particles traveling faster than the speed of light ... But we now know that a tachyon indicates an instability in a theory that contains it. Regrettably, for science fiction fans, tachyons are not real physical particles that appear in nature.