Dunno. Try it and find out.
Nah, I'm just joshin'.
Well, if you went back and killed yourself as a baby, then the baby you would die, obviously. But if you died at that instant as well, wouldn't you both go to the afterlife (assuming there is one, obviously)? Or would only one of you get to the Pearly Gates?
And when you time travel, do you actually move through time, or do you simply get there in an instant. 'Cos if you actually moved through time, then your time machine would have been in that same position for all that time. Excpt back...okay, this is where I quit.