If you see a mock up of einsteins theory of relativity, it shows a clock at 12.00, then you move away at the speed of light, the image of the clock will still say 12.00 .for eternity as it ,and you ,are travelling at the same relative speed ,, if you go faster, the image will not be able to keep up with you, and as the next minute has not yet happened i.e. 12.01, then you will be going faster than light and now you are going backwards through time ,and if the image was on the same wavelength, then you would see the past, but not be able to interfere as you are seeing images, not reality.I would like to think that old h.g.'s story of time travel could be possible, but somehow I think watching old films will be the nearest we will ever get to being back in time. BUT, a man has recently put forward a theory that with his circle of laser beams, he will be able to create a point in time that he will be able to return to. AND, some scientists somewhere say that they have sent an electron around their big ,miles long tube, and it went faster than light, and they received a "ping" from it BEFORE it had left. so, who knows. but, the one thing that bugs me is: if someone invents a time machine in the future, why haven't they come back and told us about it?