The Grandfather Paradox

I’ve recently been flipping through the pages of Black Holes, Wormholes & Time Machines
by Jim Al-Khalili while I’m “working” at the library. One thing that I found interesting is the grandfather paradox. For those of you who do not understand what the grandfather paradox is, explains it—

Suppose you travelled back in time and killed your biological grandfather before he met your grandmother. As a result, one of your parents (and by extension, you) would never have been conceived, so you could not have traveled back in time after all. In that case, either your grandfather would still be alive and you would have been conceived, allowing you to travel back in time and kill your grandfather, and so on…

The thing that really intrigued me was Al-Khalili’s explanation of the grandfather paradox. He used the movie Terminator, which I’ve really wanted to see lately, even before I ever saw this book. Coincidence? The author recited the story while going into how the Terminator had to lose. See, if Arnold actually killed Sarah Connor, the mother of the savior of the humans, then there would have never been a need to send the cyborg back in time in the future because John Connor, the son, would have never risen. But, he would have never been born if the Terminator hadn’t been sent back, since his father was sent from the future to protect his mother. It can get a little confusing. The point is that the Terminator had to fail. Otherwise, we would have ended up with the grandfather paradox.

If Arnold had succeeded in killing Sarah, then he would have never been sent back in time and actually not killed her. Therefore, John would have still been born. And it becomes and endless loop. So, the Terminator cannot win. It is impossible. Unless, of course, an alternate universe was created if he did not fail; but I won’t get into that. That’s a whole other discussion.

Okay, so I know this wasn’t the greatest topic to write about, but I needed something to put in this blog tonight. Plus, it’s interesting if you didn’t know much about the grandfather paradox.