I have to tell you: I don’t believe in time travel. I’ve read the articles about how a super-sonic jet traveling from New York to L.A. actually travels backwards in time something like 2 seconds. And I read the book “Elegant Universe” (by Brian Greene) and almost understood the part where the front end of a dragster is traveling at a different speed from the back end of the same dragster.
Still, those issues are to traveling backwards through time to your grandad’s day what me eating a single undercooked piece of battered fish is to the entire commercial fishing operation of the whole world. Sure there’s a correlation, but not what you’d call a noticable one.
The simple reason I don’t believe we (or anyone in the future) will ever be able to travel back in time is that if it were ever to become possible we’d know about it. Someone from the future would come back and monkey with our time, or tell us about the future. Or, as in my book “Saving Time”, time itself would become so unraveled as to be unlivable. (Though, I suppose if that happens, we either a] won’t be able to notice or 2] won’t notice for long!)