Say you had a wormhole, with both ends near you. Each end connects through a 'fold' or 'tube' in space-time to the other end. Modern physics says one would need negative energy or matter to hold it open; for the sake of argument let's say we have it and the wormhole works, without closing upon use.
If one end is accelerated relative to the other, in the manner of the twin 'paradox', and brought back to its previous position, a 'common sense' application of relativity tells us that the travelling end would have experienced less time than the stationary, and thus by going through one end to the other, one could travel backward or forward in time, depending on which end you entered.
Would this actually work? I don't know, I haven't seen the math. There are a lot of potential problems - might the connection between the ends snap, with the stress of relative movement? Would the time-dilation effect actually apply to something connecting two points in spacetime? And how would we get the negmatter?
If one end is accelerated relative to the other, in the manner of the twin 'paradox', and brought back to its previous position, a 'common sense' application of relativity tells us that the travelling end would have experienced less time than the stationary, and thus by going through one end to the other, one could travel backward or forward in time, depending on which end you entered.
Would this actually work? I don't know, I haven't seen the math. There are a lot of potential problems - might the connection between the ends snap, with the stress of relative movement? Would the time-dilation effect actually apply to something connecting two points in spacetime? And how would we get the negmatter?