Quote (bentherdonethat @ Dec 11 2011 06:49am)
AFAIK time travel into the past is theoretically impossible, but "time travel" into the future is possible via the time dilation effects of traveling at relativistic speeds. The only problem is that you couldn't come back home. It'd be a one-way trip, and if all civilization collapsed while you were gone, you'd be awfully lonely.
True: 1) the second law of thermodynamics (increase of entropy with increasing time) explicitly makes 'backward timetravel' impossible for macroscopic objects.
2) the key to time dilation is not travelling at relativistic speeds but accelerating to relativistic speeds, slow down, and accelerate backwards to relativistic speeds to go back. You can also use gravitational forces instead.