Conway and Free Will, Continued


The indeterminacy of measuring spin reminds me of another case of supposed indeterminacy, which is really an illusion of what can be called "first-person indeterminacy".

The indeterminacy of measuring spin reminds me of another case of supposed indeterminacy, which is really an illusion of what can be called "first-person indeterminacy".

Imagine that you want to flip a coin to select a bit (1 or 0) at random. One way to do it is to throw a coin into the air in such a way that chaotic motion overwhelms the in-principle ability for any computer (including you) to predict which way it will land.

Another, more philosophically interesting way is to enter a coma, have a complete, atom-for-atom copy of yourself constructed and placed in a different room, and place a heads-up coin on the floor in your room and a tails-up coin on the floor in your copy's room. When both copies wake up, one will see heads and one will see tails.

Now, you may ask yourself, "Why did I get heads instead of tails?". In the first case it's because of the way the coin landed. In the second case, it's because of which room you woke up in. But something is interestingly different in the second case -- you may ask, "Why did I wake up in the heads-room, instead of the tails-room?", but the guy in the tails-room can ask the same thing, and no answer can satisfy you! The reason is because it involves that word that so often brings puzzlement to our lives: "I". From the third-person perspective, everything has happened for a reason and Leibniz's principle is satisfied. From your "first-person" (yes, these are scare-quotes) perspective, something has happened for no reason at all.

I am taking this analogy as the beginning of a line of questioning in which I intend to ask whether Conway and Kochen's paradox can be accomodated by a "Many-worlds" type of solution. In outline: the first measurement has a 50-50 chance of being a 0 or a 1. Which result you see is entirely dependent on which universe "you" are in. (If things are getting too crazy at this point, please check out the references at the bottom of the "Game of Life" post, as well as Nick Bostrom's site.) Before you see the result, your existence is entirely unaffected by which value you measure, so the differences between the "0" universe and the "1" universe do not really make a difference. Once you make the measurement, though, you have learned which universe you're in. That's why it seems completely arbitrary whether it was a 0 or a 1.

Posted: Thu - March 24, 2005 at 09:02 PM | | | |

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