Time travel to the past does not exist because there is really no such thing as "time" to travel through. "Time" is only a creation of human intelligence that tracks the passage of growth and decay. The chemical proceeses can't be reversed...hence, no Time Travel.
At least that's how I see it...
According to Einstein, the universe is forever expanding and we (earth) are hurling through space with it. Time as most know it (revolutions of earth around the sun) cannot be reversed, however, true time is measured by how far we travel through space away from the center of the universe, and is measured by the speed of light. Now if you can wrap your head around this, if you could travel at the speed of light in the opposite direction of earths travel through space, time would stand still. If you could exceed the speed of light, then theoretically you would be traveling back in time. Only thing wrong with his thinking is, even if you could accomplish this, and it was true, if earth is already in the future from where you are then how are you going back in time?
Time only exists in the past. there is no future time to measure, nor is there a present because as soon as time is measured, it becomes the past. Light on the other hand can exist in the future if ole wild hair is right. If you could travel the speed of light, and traveled in the same direction that earth was going, you could indeed arrive at a point in time before earth, and when earth catches up, everything on earth would be older, but you would remain as you left.
Of coarse this is all theory and impossible for us to prove at this point, but someday I really think a human will be able to travel that fast without disintegrating and will prove once and for all if time travel is possible.
