Does exceeding the speed of light lead to time travel into the past?
PURELY THEORETICAL would be the Theory of Relativity, which says that it cannot be done. There are no reference frames that travel faster than that of light relative to one another, and so there are no speeds up there to get to. It also implies that observers will disagree on whether a Hypothetical faster-than-c particle traveled from Point A to B or from B to A, as that would depend on reference frame. A tachyon detector would also be a tachyon emitter and one could never determine whether a given tachyon had been received at or emitted by the device. Such devices could be used for communication with past events by transmitting between devices in different reference frames. If you could tell who was talking and who was listening, which you can’t.
