Grandfather Paradox

What is the Grandfather Paradox?

OK, so the idea is that if you went back in time and kill your grandfather, then how would you be born, thus creating the paradox. Actually, according to Steven Gibbs what happens is that the time line would split into two separate lines. On line A (the original line you are born and go back) on line B (the incident occurs and you are never born).

As time goes by, the two lines become more and more distinct. However, this means that there is never a paradox, because you never kill your real grandfather, only a man on another timeline that looks and acts very similar to him, therefore the Grandfather Paradox never happens.