Re: another paradox and a solution

From: Wei Dai <weidai.domain.name.hidden>
Date: Sat, 28 Feb 1998 14:26:33 -0800

On Sat, Feb 28, 1998 at 01:57:12AM +0000, Nick Bostrom wrote:
> Only on the AUH, right?

I'm not sure what you mean by "on the AUH."

> Isn't it the case that on the AUH, *everything* remains the same no
> matter what I do?

No, because your actions affect your future perceptions. I think Tegmark's
distinction between the inside view and the outside view is very important
here. From the outside, everything is fixed and timeless. But from the
inside there is a flow of time and actions have consequences.

> In one sense, yes; in another sense, no. I think it's the same as
> with any other physical theory.
>
> The sense in which I *can* make a difference,on the AUH, is I think
> the following: If I choose to do action X, then that indicates that X
> is a rather probable thing to happen (it has a big measure, even
> though in some universes I will not do X in a similar situation). It
> might not matter whether we say that I "cause" X to have a big
> measure by wanting it, or we say that the ground why I want X is
> that the event of me bringing X about by wanting it has a relatively
> big measure.

Ok, but how do you apply decision theory when the probability of your goal
being reached is either 1 or 0, independent of your decisions?

> It looks to me now as if your definition of this probability agrees
> with the (second) one I suggested (and which you say that Tegmark
> also uses), except that I assumed a finite number of discrete
> universes, whereas you stated the definition in terms of measures.

First let's agree to use measures since that works even when the number of
universes is finite. Your definition is

A. The measure of my future continuations perceiving X, divided by the
measure of my future continuations.

My definition is:

B. The measure of my future continuations perceiving X, divided by the
measure my of present self.

Tegmark defines it a different way, but I think it is equivalent to
definition A. The point of introducing definition B is that definition A
is not self consistent.
Received on Sat Feb 28 1998 - 14:27:09 PST