i have a theory that if someone were to manage to travel in time what he would see or experience would be an after-image of the energy that was there. i don't believe he would be able to alter any of it though. energy dissipates or transforms in the universe, it never disappears though...everything is composed or connected to some type of energy, time simply can't be stopped, even frozen space continues to move, but maybe traveling or rewinding the road in the state of energy is possible
humans have done some really amazing shit so far...& that's in only 2000 recorded year history
imagine a couple of thousand years more