Fringe Science.

The topic of this weeks episode of Fringe was time travel, and it really got me thinking; is there a point to traveling back in time?

I certainly understand the motivation behind time travel: fixing an unpleasant occurrence, taking a different road and all around changing the present. Is that how it really happens though? Is it that simple? Assuming time travel were possible for everyone, would you be able to actually change anything?

For this next point, I have a significant other named Betty and she was killed in a horrific car accident, and time travel exists. Anyway, because of my undying love for her, I would return to a time before the accident and tell her not to drive that day. In doing so, I save her life. But wouldn't the motivation for traveling back in time be eliminated? Would there be a reason to travel back? If there is not, then would my beautiful Betty still be dead?

If this is the case, then the only way to change the present would be to relive your life in the past in order to have a different future. In this case, there would be two of you running around the past and therefore the present and the future, and that could just be a mess. So what does time travel really accomplish? Is it really necessary? I don't see its purpose.