Recently the was a PBS documentary called "Universe" The idea of time travel was discussed at length with a lot of interesting explanations. The one thing that was consistent from Einstein to all of the physicists and other scientist was that time travel is likely to be possible, but only in one direction, into the future. The bad news is you could not come back. Going back would not be possible, according to the physics is because and change, just the mere fact that a single person goes back to an event or time, it changes the mathmatics, which in turn would change everything. As I remember they said to look at it like the time traveler at a time in the past as the apex of a large "V" The amount ot time between now and how far back the time traveler goes effects the size of the "V" The mathmatical effect will become magnified and what mat seem like a small change at first is actually very large and gets larger as we go into the future at normal time. It has something to do with "string theory." Note any physicists on EP, which I am sure there are many, LOL, please forgive this laymans amatuer explaination. Stephen Hawking and Brian Greene did a much better job than I can a month after seeing the show. LOL!
Quantum psychics, time travel, parallel dimensions....fascinating stuff!
it goes nicely with our tin hats