Temporal Recursion

Have you ever played the game Ocarina of Time for the Nintendo 64? Well, let me explain a bit. This game involves a ocarina, which your main character Link, can learn songs for. Playing the songs causes various magical effects to occur.
You can also travel through time, from when Link is a child to when he is an adult, and back. In one of towns, there is a large windmill. If you go there as an adult, and talk to the proprietor, he will teach you The Song of Storms, which some kid with an ocarina played several years ago that summoned huge storms and destroyed the windmill.

If you now travel back in time, go to the same windmill, and play The Song of Storms, you will summon huge storms and destroy the windmill, and the proprietor will ask "Where you did learn that song?! Argh! I'll never forget it now!"

The burning question, though is where did the song come from? Apparently, the song just appeared out of nowhere. Tho proprietor taught it to Link who taught it to the proprietor who taught it to Link who taught it to the proprietor who taught it to Link who taught it to the proprietor who taught it to Link who taught it to the proprietor who taught it to Link...(see recursion)

A more homey example would be if you were creating a password to convince yourself you have traveled back in time. Let's say PSelf gets a call from FSelf, and despite PSelf not having had the good fortune to read said E2 node yet, FSelf is a very persuasive speaker and convinces PSelf not to press the button. PSelf decides this would be a good time to remember that password, just in case he ever needs it again. Whew.
Now, where did the password come from? It just appeared recursively out of the folds of time! FSelf taught it to PSelf who taught it to FSelf who taught it to PSelf who taught it to FSelf who taught it to PSelf who taught it to FSelf who taught it to PSelf who taught it to FSelf who taught it to PSelf who taught it to FSelf who...you get the idea.

So, next time you go time traveling, don't be afraid to leave one of these cool little easter eggs, they're fun fun fun!

If you went back in time to stop yourself doing something, then would that change the future? If so you would create a completely different future, one where you may not have the opportunity to go back and create it again by stopping yourself doing something. Of course you also wouldn't know why you ought to stop it because you would never experience the bad consequences of it because the you from the future who did experience them stopped your past self and thus created a new future and a new you.

If, however, you cannot alter the stream of time, and the future is the past to the future's future, then you going back to stop yourself doing something will always have happened and when you go back to do it you will remember being young and seeing your future self warning you, thus nothing will change; either your past self will do it regardless of your efforts or something else entirely will create the bad situation you wished to avoid in the first place.

Of course there is always the possibility that time travel is not possible, but that is no fun at all is it?

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.