Problem is, people fail to differentiate between "FTL" and "Taking a short cut while not actually moving faster than light thus arriving to the destination sooner than light did, because it took the long way around".kingpocky said:I don't know if it's MORE possible, but if FTL is possible, that means that time travel is possible.
http://thebestforumever.com/community/threads/tachyon-pistol-duel-thought-experiment.47326/
The other important thing to consider is that particles can and do move faster than light in a medium sometimes, (look up Cherenkov radiation), the speed that's the absolute limit is the speed of light in empty space (vacuum).
Also, tachyons are purely hypothetical at this point (and are likely to stay that way).