== Time travel to the past in physics ==Time travel to the past is theoretically allowed using the following methods:* Traveling faster than the speed of light* The use of cosmic strings and black holes* Wormholes and Alcubierre drive=== Via faster-than-light (FTL) travel ===If one were able to move information or matter from one point to another faster than light, then according to the theory of relativity, there would be some inertial frame of reference in which the signal or object was moving backward in time.
=== Časovni turizem ===Hawking je predlagal, da je odsotnost turistov iz prihodnosti argument proti obstoju časovnega potovanja; to je različica Fermijevega paradoksa.