yes thats actually true, forward time travel is actually possible at this time, its just the cost and time needed to create the technology is not yet feasable. basically, according to the theory of relativity, your experience or 'viewpoint' of time is slower compared to that of other people the closer to the speed of light you are travelling. Scientists have done experiments where particles are accelerated to very close to the speed of light and when they are examined have aged alot less that they would have going the same speed as evrything else on the earth. But because of the huge speed of light, someone travelling at 1mph and someone travelling at 30mph would experience such tiny difference in time that normal clocks couldnt detect, and atomic / caesium clocks etc would only just see a difference. Its a bit like cryogenics (freezing people like in Futurama) where your opinion of time seems exactly the same to you, but outside whatever it is (whether some sort of stasis machine or the machine that enables you to go round and round in a circle at the speed of light -.000000000000000000000000000000000001) time goes VERY fast, so that when you leave that particular area, maybe 100 years would have passed, but you would have experienced very little. In different areas of space, where the space around you is at different speeds, the same thing happens, so if you are in orbit time will go faster for you than people on the earth.