----- Original Message ----- From: "Richard Baker" <[EMAIL PROTECTED]> To: "Brin-L" <[EMAIL PROTECTED]> Sent: Monday, February 25, 2002 6:17 PM Subject: Re: The Shooting Room Paradox
> I said: > > > Another fun one is Newcomb's paradox. You're invited to play a game. > > There are two boxes. Box one contains USD1,000. Box two contains > > either nothing or USD1,000,000. You may not in any way examine the > > contents of the boxes without opening them. You may open either box > > one or both boxes. You win whatever is in the box or boxes you open. > > Now, here's the tricky part: the content of the second box has been > > chosen some time before the game starts by a god with perfect > > prescience, and said deity has put USD1,000,000 in the box only if he > > foresees that you won't open it. Should you open box one or both > > boxes? > > Ack! I screwed it up! > > Here's a corrected version: > > You're invited to play a game. There are two boxes. Box one contains > USD1,000. Box two contains either nothing or USD1,000,000. You may not > in any way examine the contents of the boxes without opening them. You > may open either box two or both boxes. You win whatever is in the box > or boxes you open. Now, here's the tricky part: the content of the > second box has been chosen some time before the game starts by a god > with perfect prescience, and said deity has put USD1,000,000 in the box > if he foresees that you only open that box. What should you do? > As defined above, its clear that you should only open 1 box. If you do, you might get $1000 and you might get $1,000,000. If you open both, you get $1000. The way I remember the story is that the deity will put the 1 million in only if you open 1 box, but said deity will not automatically put it in if you only open 1 bag. The answer to that question depends on other qualities of said deity. In particular, if he forsees that you only open one box, how often does he put the money in that box; and how often does he put it in the other box. If he is equally likely to put it in either box, it is clear that only one box should be opened. Dan M.
