h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Although this idea has probably never entered the realm of television or movies, I find quite interesting. I came across it in a book I was reading. If I were to go back in time and meet myself, I would have effectively cloned myself. If I did this mulitple times, I would double the copies of me indefinitely, creating a virtually limitless army of myself. (I do remember Agent Smith in Matrix II fighting Neo hundreds at a time, but that was different, right?). One can only imagine the power I could unleash on the world...

This was done on a cartoon called "The Brak Show" which aired in the states during the "Adult Swim" nightly segment on Cartoon Network. Brak and Zorak (two characters spun off from hilarious cartoon talk show 'Space Ghost Coast to Coast' and previously on the old cheesy adventure cartoon 'Space Ghost') are playing a violent video game and Brak puts off doing his homework until the weekend end is over. Zorak suggests they use the neighbors' time machine to send themselves back to Friday afternoon to remind brak to do his homework... Of course these temporal clones also spend the entire weekend playing the video game and so on and before long there are dozens and dozens of Braks and Zoraks. If you're familiar with the Brak character, you'll understand the comic possibilities of this situation.

Another 'Adult Swim' cartoon did the same thing but with much more violence, and for some reason lots of dodge ball. This was 'Sea Lab 2021' but they were also caught in a temporal causality loop. Each set of clones were created when the sea lab explodes while two of the characters were trying to steal cable causing a time warp. Everytime they swim back to the lab to stop their previous selves from going out steal the cable, they get thrown in the brig... which eventually gets filled with temporal clones, some of which are mutated. I really don't know how to explain how dodge ball comes into it.

But surely these clones could only last a certain amount of time. Once you hit the time period that the clones were from then the original version of you would have to travel back into the past so that you become a clone. Eventually all the clones would do this so you'd run out.

Of course, you could get around this problem by getting more clones from further on in the future and simply repeating the process, but then it might just get confusing.

If that were true, then time travel would not be possible. The whole point is to dislocate yourself from the normal temporal stream. If we were to go back to a time before our birth, we would disappear, since we would not exist. But the notion of time travel prevents that. Same with going into the future. I think what would end up happening is we would get stuck in a temporal loop, a la Star Trekkie, explained before, and our army of clones would mulitiply exponentially and infinitely.

An excellent example of this is demonstrated in Robert Heinlein's short story "By His Own Bootstraps". In this story, the main character keeps going back in time (using a sort of charmed mirror) to try to stop himself from doing something. The reader follows the hero through the story on his personal timeline. Whenever a future version of himself shows up to tell himself something however, his current self never recognizes his future self. You follow this character through the mirror several times, each time recognizing that the current character was previously another character, and find that there are NO paradoxes.

It is basically a drawn out version of something DNA expressed very succintly in Life, the Universe and Everything... When Ford and Arthur are back on earth at Lords Cricket Ground, Ford senses an urge that Arthur has and tells him not to do it. Arthur asks, "Don't do what?"
"Don't phone yourself."... Arthur asks, "Why not?" and Ford demonstrates... Ford picks up an imaginary phone and says into it, "Hello? Is this Arthur Dent? Don't hang up!" He looks into the phone with a disappointed expression. Arthur asks, "What happened?"
"He hung up," says Ford.

Same basic principle, but without all that mucking about.