Time is relative. I think it could be possible to travel into the future, but to travel back into the past-I'm not sure. Although very much like reflecting light I guess it could be possible to view the past rather than physically being there. It would take so much energy to accomplish just a minut effect of time travel I don't see how it could be done-. I believe it was Thorton that said it would take more than a hundred years of gathering potential energy from all of Earth's sources to manipulate time. I guess through future technology it might happen.