Did science ever prove the existence of a Tachyon?
In theory they can travel faster than the speed of light.
I don't believe they have been discovered. So far, the boundaries on the speed of light still stands.
never heard of it... thank you for teaching me a new term...
They have not been proved to exist but they probable do, nothing can go faster than the speed of light, it just warps space and time.
The property of causality, a fundamental principle of theoretical particle physics, does not pose a problem for the physical existence of tachyons. It is not generally realised that if a tachyon were to exist and were allowed to interact with ordinary (time-like) matter, causality would not be violated; this despite that there would no longer be a way (relative to the tachyon) to tell the difference between the future and the past along the worldline of a given piece of ordinary matter. A particle could seemingly send energy or information into its own past, forming a so-called causal loop. This would lead to logical paradoxes such as the grandfather paradox, if it were not for the Feinberg reinterpretation principle which states that a negative-energy tachyon sent back in time in an attempt to violate causality can be reinterpreted as a positive-energy tachyon travelling forward in time; for a tachyon there is no distinction between the processes of emission and absorption since a sub-light velocity reference frame shift can alter the temporal direction of its world-line, which is not true for tardons or photons. The attempt to detect a tachyon from the future actually creates the same tachyon and sends it forward in time. The effect of the reinterpretation principle on any tachyon "receiver" is that any incoming tachyonic message is lost against the tachyon background noise, which is an inevitable accompaniment of detection/emission; a tachyon detector will register tachyons in every possible detection mode. Tachyons (if they existed) could be used to transmit energy-momentum, but they can't be used for communication. Thus there is no need to fall back on the some quantum field theory form of the Novikov self-consistency principle to preserve causality.
Other avenues of speculation involve parallel universes. One can imagine a scenario in which sending energy or information back in time causes history to diverge into two distinct tracks, one in which events reflect the altered information and one in which they do not.
In the theory of 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 Alcubierre metric. However, these are not tachyons in the above sense, as they do not exceed the speed of light locally.
It's a hypothetical particle that have not been observerd physically. It may be a anomaly in some theory or it could be a byproduct of some gaps in known theories.