Quantum Physics 123: Monday 14 November

[ten-and-chips.livejournal.com]

[The Doctor sits on top of his desk, swinging his legs, as the class enters. He's got coffee and tea for all. They'll need it.]

The American cartoonist Walt Kelly once said 'We have met the enemy, and he is us.' This is often used to explain the idea of a predestination paradox, the first of this week's return to the concept of paradox itself.

Simply speaking, a predestination paradox occurs when a person goes back in time to prevent an event, but ends up causing it. This is also known as a causality loop. For example, if someone were to go back in time in order to prevent an assassination, but a series of events led to his or her being the cause OF the assassination--that would be a causality loop. This happens far, far more often than one would think.

Some would say that this sort of paradox proves the existence of fate. Others say that it proves that time itself is more resilient than most believe. The Novikov self-consistency principle is one of the theories that supports this.

In my experience, it is the error of sentient beings themselves that causes this sort of loopage. However, your belief in this area should be the result of your own judgment, whether faith or scepticism.

Any questions?

I'd like a short essay from each of you by Wednesday speculating how you could cause a predestination paradox in your own life by merely trying to change one small event.

Comments

[whitedeathpod.livejournal.com]

John raises his hand slowly. "Sir, I've got sort of a complex question. On the topic of the casuality loops, let's just say I went back in time to stop something from happening and, in doing so, I end up becoming the cause. Would it be possible for another John Crichton existing in that same universe to mop up my mistake or would that cause more problems?"

[ten-and-chips.livejournal.com]

[He thinks about this for a moment.] Well, there would already probably be a temporal problem with two John Crichtons existing in one universe. I believe we talked about that before. But if the second John Crichton went back in time and stopped the first, that could possibly stop the causality loop. The problem would be the multiple instances of Crichtonage the two existing in a space meant for one. There can be only one...wait...wrong fandom...