Ok, this is getting a little strange. A friend of mine and me were thinking about things like this, and we came up with the exact same conclusions you have. How every single minescule difference that could happen (even down to the attomic level) starts a separate dimension, kind of like a branching tree, and that separate dimension branches infinately, and so on. So what one would have is and infinate number of dimensions upon an infinate number and it just keeps going and going. It's a number so much larger than infinity. But thinking in that way would mention that there really is no past, because looking at this growing tree of dimesions, one would never re-trace his steps backward, but would always be going forward, but to him, it would seem as if he is going backwards, yet, it's just another dimension that has started so in truth he is going forward. Have I lost you yet? Therefore, that kinda stops somone from going back in time and killing thier yonger self, sure you can do it, but nothing will change, you will still be there because you didn't actually re-trace your steps back down the tree.

• Ain't it neat how these things happen? - Astrophysicist - July 8, 1998 - 12:07 UTC