Free will

From: Saj Malhi <sajm.domain.name.hidden>
Date: Wed, 20 Jan 1999 23:38:20 -0000

Two people make a bet based on the toss of a coin while a third unobserved person looks on discretely from the corner. The probability of heads or tails is fifty-fifty, 0.5. The coin lands heads, one of them loses, fair enough.

Having seen this, our voyeur steps out of the room, gets in his time machine, and returns to witness the same event. But what are the probabilities of heads and tails now? Are they still fifty-fifty, or are they now 1 and 0 respectively?

This little argument seems to pose 3 possible conclusions.
1. Time travel is impossible
2. Probability (and therefore our human concept of free will) is an illusion (assuming of course, that someone with a capital S is watching over the proceedings).
3. There is a fundamental flaw in this line of reasoning.

Does anyone have any comments?
Received on Wed Jan 20 1999 - 15:42:49 PST