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Artemis Fowl
Paradox and Antithesis

What is a time paradox?


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October 15, 2010 3:38AM

A time paradox generally refers to a paradox of time travel.

The most well-known time paradox is the grandfather paradox. Follow the logic here: If you went back in time and killed your grandfather, then your own father would never have been born and thus you would never have been born. However, if you were never born, then you could never have have gone back in time and killed your grandfather. Therein lies the paradox. What would happen then? Well, since no one's ever traveled through time, it's impossible to know for sure. There are some theories:

  1. According to the Back to the Future films, the universe would explode.
  2. After killing your grandfather, you would return to the present only to find yourself in a world where you don't exist. Basically, you would be like James Stewart in It's A Wonderful Life.
  3. According to the Novikov self-consistency principle, if you went back in time and tried to kill your grandfather, you would find yourself unable to.

Another time paradox is the predestination paradox, also known as a "casual loop". This was demonstrated in an episode of The Twilight Zone where a man traveled back in time to determine the cause of a famous fire. While in the past, he accidentally knocked over a kerosene lantern and started the very fire he was trying to determine the cause of. Unlike the grandfather paradox, this does not create a contradiction. In fact, strictly speaking, this is perfectly consistent. However, it's a paradox because it seems to indict that free will doesn't exist or that it's an illusion.

An ontological paradox is kind of a version of the predestination paradox. Now, let's say that one day your future self shows up and gives you blueprints to build a time machine. You then build a time machine and travel back in time to give the blueprints to yourself, closing the loop. All this begs the question, where did the blueprints come from in the first place? Well, nowhere, apparently. Perhaps from an earlier timeline.

A quick expanation of a time paradox is imagine if you had a time machine, and you went back and killed your grandfather, as a consequence of this your father or mother would never have been conceived, and thus neither will you have been. The paradox comes into play as this, if you were not conceived because you had killed your grandfather, and your parent wasnt born, and you werent born, this means you didnt exist, and If you didnt exist, you werent around to kill your grandfather in the first place, so your parent will have been born, thusly you would have been too. Its all very confusing. Also, imagine someone you love dies,and you go back in time to save them, and you do, the reason you travelled back in time is to save that person, if that person is saved and alive and well, there was no reason to go back in time anyway, so the loop begins again.

Also in the new show into the universes with Stephen Hawking a crazy scientis builds a time machine, sets it to be a minute earlier then the present, assembles a gun, goes to the other side of the time machine sees himself assembling the gun and shoots himself through the machine.