[arkaznor]

Time is just change. Once something is changed, it can't go back on that. It would have to change to what is was before.

Time travel into the "future", is theoretically possible; it would just be skipping some of the change, no paradox.

But traveling back in time is different. If anything could travel back in time, it would cause a paradox. Anything that is involved in a paradox is eliminated from the beginning of change. Thus, with the whole idea that anything affects everything, it's very likely that the entire universe would be erased before it even existed.

Though, you could change everything back, and then it would change to how it was/ would be. Or you could travel to another dimension.

But then that gets into pocket dimensions, and alternate universes, and Bullet Magnet's tree idea (But a little differently), and the whirlpool theory.