>>11242610Technically, the person talking into the radio is doing so several milliseconds before the person on the other end receives the signal, accounting for the delay. By that I mean, the guy going super-sonic is actually traveling "through" time faster than the guy sitting near the radio receiver. It might seem that the conversation is instantaneous but that's not actually the case. If you could time it, the delay would be infinitesimal, again accounting for the natural delay in a radio wave, but it would be there.
>>11242680It's not really that complicated. Movement across space-time is what we perceive as time. For instance, an object in space that had no gravity of any kind acting on it (which isn't possible, since by definition everything is effected by some degree by the gravity of all mass in the Universe, but for the sake of argument, just pretend), time wouldn't exist from that objects perspective. The Universe would be static because of the complete lack of movement along the actual shape of space time.
You perceive time linearly because the motion of the Earth orbiting the Sun, and the Sun orbiting the Galaxy, and the Galaxy moving through the Universe, all impart velocity on you and thus you are always moving in one direction across space-time.
Basically, what i'm trying to get at is that you are technically experiencing "time travel" right now, simply by the motion of your body across space-time. An FTL capable ship would likely be able to travel either "direction (meaning: forward or backwards)" because the normal velocity limits that prevent such travel wouldn't apply. Worm holes do this too, since a wormhole leads to another place/time in Space.
tl;dr, time is the perception of motion through space-time. FTL would allow movement anywhere and anywhen as a result.
