Time travelers aren't constantly changing the past.
Adam Rifkin stashed this in Time
If time travelers were changing the past, the past would be more awesome.
Harvard University Physics Professor Gary Feldman says: "If time travelers are constantly changing the past, they are not very good at it. Why did they not avoid two disastrous and pointless world wars in the past century?"
The past *is* more awesome. Until 20 minutes ago the 20th century never had penicillin. I just went back and forced Albert Fleming to look long and hard in that petri dish and you are already TAKING IT FOR GRANTED, ADAM.
Yesterday there was no internet. I went back and inspired that this morning. And as for the two World Wars, hey, nobody's perfect. I'll fix them tomorrow.
Or, maybe those two World Wars had a point, and it's not for us to understand why.
If you go back and change, what is for you, an historical event, it would essentially be the same thing as jumping a time track into a quantum parallel. It wouldn't change your history, or your world, but would orient you into an alternative universe where the changed event is now just as causally fixed as the original event is to your personal history. To everyone else in your home universe, you'd simply disappear and never return, while they continue on with their original causal track.
I've seen the Terminator, like, *seven* times so I know you're wrong.
Definitely one of my favorite posters.. :-)