If you went back in time with a copy of, say, Lord Of The Rings, and submitted it for publication under your own name before JRR ever even thought of it, then he will obviously never write it (since it is already written).

You have just created a bestselling book that was never actually written.

The thing is, it was written, just in a different timeline. One theory suggests that even if time-travel were possible, a human would only be able to travel back a few times (unless they were short distances) before he would become confused and disorientated, and forget which timeline he was currently experiencing.

Travel forward would not pose this problem, since you would not move into a different timeline.

TotalRetard - time travel is most certainly possible, at least forwards. Backwards is another story.