Einstein theorized that if we could go at the speed of light or perhaps faster then time would be slowed enough to go back in time...(so slow it'll be going in reverse another words)
Yet i'm kinda skeptical, because since the past has already happened, it may not be possible to go back however it may be possible to go so fast that we just speed our passage through time, much like sticking ourselves in a cryochamber and doing it the slow way.
Just to completely confuse everyone: Don't you think that if there was such possibility of time travel, that everything would be already perfect, because someone would have put a few stops to a few things...i.e killed Hitler as he was born etc. So to me if time travel was possible, there would already be a future, and thus our futures are already predetermined by the greater power called Time.
So if anyone doesn't know the answer to the riddle called god (He is with you everywhere - any church priest) the answer is time.
See i side tracked myself. O.o .
So what am I saying over all:
A) If you believe that you create your own future, time travel does not, and will not ever exist, and Einsteins theory is completely incorrect.

If you believe that your future is created for you and that you follow the path that is before you then time travel does and will at some time in our time line, and that Einsteins theory is correct, and that there are multiple timelines all coexisting with each other returning to it's beginning to continue again.
If that's not logical....I don't know what is.