Time Travel Paradox Explained....

This is a bit techy so be warned...

Basically.. it's string theory. When / if you travel back in time you create a new universe. IE the paradox "how can I go back in time and kill my grandfather, if I did that wouldn't I never exist in the first place?"... this is explained in string theory (IE the multiverse).. once you go back and kill your grandfather, the universe you were born into erases you from existence. However the universe you just created in which you killed your grandfather, you do now exist. You being born outside the universe allows you to continue to exist but live in your own paradox.....

This is how the TNG crew were able to go back to 2063 and involve themselves in the first warp flight. In the universe they were born in, it never happened. However in the new universe they created by going back in time, it did. In fact, in the show enterprise Archer talks about old stories Cochran would tell about "robots from the future trying to kill him, and people from the future saving his life and helping him fix his ship"... they dismissed it as a hoax until they discovered frozen borg on earth.

This is also how JJ Abrams re booted the story of Kirk, while still having old man Spock in the same universe. Comic books were waaay ahead of the curve on this and real world scientists now believe it is actually possible.


Hope that helps plot hole searchers out there.