Quote Originally Posted by =sw=warlord View Post
Two words.
Slip Space.
Slipspace or hyperspace or whatever hypothetical shortcut through space is still time travel. You are leaping outside of your light cone to a point in space with no causological relationship with the event of your "Jump". You are violating causality, which is the fabric of the universe.

Since simultaneity is relative, you could theoretically jump back to your point of origin before you left. Paradox!

I don't believe in paradoxes, which is why I don't believe FTL travel or time travel will ever be possible. Well, not without permanently losing the ability to interact with the known universe. But I forgive science fiction for treating relativistic distances as if they are still governed by classical mechanics. No FTL travel is a bummer, creatively.