Back In Time

I watched a fascinating episode of Carte Blanche tonight which dealt with time-travel.
I'm no rocket-scientist but I was intrigued to learn that it is absolutely possible to go back in time! Theres something called Relative Physics and then theres Quantum Physics.
In a nutshell, while it may be possible to go back in time and change certain events, how those events would affect the present falls under the realm of "uncertainty".

The example the scientist gave was a person who goes back in time, far back enough to ensure that his grandparents never meet, hence his parents never meet, culminating in the person never being born.
Possible? Yes, absolutely. But it does not mean he will not continue to live in a parallel universe. Huh?

Ok so heres the thing. Yes you could prevent your grandparents meeting.
Yes you could prevent your parents meeting.
Yes if they don't meet it would mean you were never born.
However, since it is YOU that is doing all this prevention, it would mean that you have to be alive at that time. How else would you prevent all the other events from happening?
Since you have to be alive  at the time, and having come from the future, whilst preventing your grandparents and parents from meeting, it means that you would now exist in a parallel universe!

Cool huh.

Now heres another conundrum for everybody who ever thought they could go back in time to get the winning Lotto numbers, or the name of the horse that won the July Handicap.
Imagine having arrived in the past, and finding that valuable information you came looking for, and headed back to the future to make use of this information... Oh hang on, if you went back in the past to get those Lotto numbers and winning horses name, in order to make use of them you would have to go further back in the past to claim your prize, because if you went to the future you would have missed the events completely!

This has got to be the most confusing post i've ever written!

For anybody who understands any of the above, i'm offering a free trip back to the past.