Light is not JUST waves. It has a dual nature, having properties that only a particle would exhibit and properties that only waves would exhibit. There are examples of these online, just google it.
I don't think time travel to the past is possible, because to do that, you would need an infinite amount of energy, and that's just not possible (physics professor at NYU explained this entire thing to me--I don't have the comprehension or patience to explain it). However, if one approaches the speed of light, one could move to the future in the sense that time travels slower when moving at high velocities. There's a formula that dictates that if one would travel for 20 years at 1.5 x 10^8 (one-half the speed of light), they would age only 10 x rad3 years, as compared to a stationary person who would age the entire 20 years. So, if one should travel at 99% the speed of light, perhaps they would age only a few seconds while the time around them passes for many years. The problem is that they're probably stuck in that time period forever.
This post was edited by sillybillyxp on Apr 16 2009 11:29pm