Re: predictions

From: Wei Dai <weidai.domain.name.hidden>
Date: Fri, 10 Apr 1998 11:37:54 -0700

On Thu, Apr 09, 1998 at 12:23:04AM +0000, Nick Bostrom wrote:
> I agree that this problem needs to be solved. I think the key to the
> solution is to note that even though every action is undertaken in
> some world, some actions are undertaken in more worlds than other
> actions. The same holds for choises. When we naively say that you
> choose A, this will have to be interpreted to mean: in most worlds,
> you choose A.

I agree that if a solution exists, this will be a key part. But I don't
think it's enough. In the outside view of AUH, there is a matter of fact
about how any decision is made in each universe. How do you define the
effects of making any particular choice? WIthout AUH you can define the
effects of a choice as the set of events that would not have occured had
you not made that choice. But with AUH this definition no longer makes
sense, because there is no possible meta-universe where you do not make
any particular choice or make that choice with a different frequency or
measure.

> I was assuming that by this time the copies have received some extra
> differentiating information, however slight. One copy might have
> heard the sound "alpha" and the other "beta". Then the one that has
> heard "alpha" could say to himself: "The probability that the copy
> who heard alpha (me) will see heads when he opens his eyes is p."
> However, I now realize that in principle, the copy could calculate
> whether it was the alpha-copy or the beta-copy that will see tail. So
> the probability would be 1 or 0 if the copy in question could compute
> this; but if there are practical limitations on his computational
> abilities then the above reasoning might still give the copy useful
> probabilistic information.

I'm not sure i understand your setup here. Can you be more explicit about
how the "alpha" and "beta" fit into the situation that we're talking
about?
Received on Fri Apr 10 1998 - 11:38:40 PDT