Okay, assuming that we someday find a loophole in Einstein’s theory of relativity and are able to travel faster than light, what will be the effects of time dilation? Since time slows down the faster you go, will time stop for those on-board? Will it reverse? Any Generally Accepted Guesses out there?
SR and GR also tell us what the effects of high-speed travel WRT to time are (SR tells us what, GR tells us why). If we assume that we can go from sub-luminal to super-luminal travel (“real” travel) in a way that punches a hole in GR, there’s no telling what the effect would end up being.
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Well, that would depend on exactly what the loophole might be. Most sci-fi books tend to rely on some means of not actually traveling faster than light, but instead, somehow altering the distance between two points, whether it is warping the space-time continuum, shifting into another dimension where distances are shorter, or not really explained. Using a loophole like that would mean you are not actually traveling faster than light; therefor, you don’t have to deal with the time dilation equation spitting out imaginary numbers. That is what you would get if a speed simply exceeded c.
Yes, but relativity still indicates non-causal results, even under those conditions. So, you’d need to build up a whole new theory of physics, or toss macroscopic causality.
Well first of all general relativity does not rule out superluminal travel. It only demands that the restrictions of special relativity hold locally. Assuming you could get your hands on some exotic matter you could travel FTL through a wormhole, and, for that matter, during the inflationary period of the big bang the entire universe expanded FTL.
So if you could manipulate space-time ala the Alcubierre Warp drive you could globally travel at speeds greater than c without ever locally violating SR.