I was thinking about this, imagine you go back in time and prevent something, like getting hit by a car, or anything that implies movement from both parts.
You go back in time and warn yourself not to go at that time, to wait around 1 minute before going;
Is it possible that after you made yourself(past) wait that minute you'd still get hit by a car?
Because after all, it all indicates to a certainty, you got hit by a car in the past, and if you went back to warn yourself in the first time, then you'd appear in every single case possible to warn yourself, thus getting hit by the car anyway.

Let me explain you this way:

You have infinite time-lines of which you can go back, you choose one, that brings you to the past, lets say 10 minutes before the accident. You warn yourself about that accident and you make yourself(past) wait around 1 minute.
After that minute he(you) would get hit anyway. Because that warn you gave him, changed the time-line, and you always leave your house at a precise point where you'll get hit by a car.

So my question is, if you can go back in time to use today's lottery numbers (which is something you can't change) in yesterdays lottery, thus becoming rich. Why couldn't you prevent a specific act to occur in a time where you are pre-destined to get hurt?

Another headache thread

Debating this is like debating all other fundamental world view questions. We don't know shit, so it all boils down to what your personally decide to believe. To me, it seems likely that whatever idea we have of how time works is wrong with an almost 100 % certainty. I don't really think time is something you can travel back in.

It's possible if you consider an alternate universe model where instead of traveling through time, you travel to a parallel but identical universe at the desired point in time.

So for every nano second in time there is a separate universe for that single point in time?

Quote from Vincent

So for every nano second in time there is a separate universe for that single point in time?

That is actually a real theory. I recently saw a History channel special on Parallel Universes; I suggest you try to view that. It explains all the theories.

i suggest everyone in this thread watches the movie "Primer" it can be found on google video and you all would enjoy it, ps, dont read about it first

You go back to warn yourself. You will not be around to warn yourself if you wait....

Yeah dude wait a little bit more what youll die ?

Oh, you know what? Just for the sake of completeness, I want to say something I think about this "going back to change something" idea. I think it's utterly impossible no matter what "theory" you're trying out. Why? Because in any case, you'd need a reason to go back in time. The classic paradox, to me at least, is if you go back in time and stop yourself from doing something, then, in the future, that something would not have ever happened and you never would have went back in time to change it.

This is why I like Daniel Faraday's theory (character on LOST) of whatever happened, happened.

I don't think that's the case.
By altering something in the past, you go to another timeline, where what you altered would happen anyway, because it's destined to happen.