I think time is just a matter of energy state changes and the only time state that is in existance is the (time) state that we are in at the moment. What I mean is the past doen't exist any more and the futher has yet to exist. This way of thinking doesn't make time travel impossible just very energy intensive. Most of the prominant physics theorists don't by this anymore even though any other way seems to violate some very basic physics.
