Re: zombie wives

From: Russell Standish <>
Date: Mon, 16 Aug 1999 13:14:15 +1000 (EST)

> 4. Subjective probabilities can be computed on the basis of the
> Strong SSA, and we get
> P(H, t1) = 1/2
> P(H, t2) = P(H, t3) = 2/3
> If this is the case, then I think we have to throw Tegmark's
> scheme using Bayesian statistics out the window. This option
> has severe metaphysical problems, though, in my opinion. I
> think Hal was saying, in his post, either this option, or
> option 1 above, but I'm not sure.
> 5. Subjective probabilities can be computed, and we should expect
> the common-sense results
> P(H, t1) = 1/2
> P(H, t2) = P(H, t3) = 1/2
> It's a fair coin, after all, right?
> I think this gets Gilles' and Bruno's vote (and Russell's?)
> 6. Subjective probabilities can be computed, and we should expect
> the nonsensical results
> P(H, t1) = 2/3
> P(H, t2) = P(H, t3) = 2/3

If the probabilities can be computed, then compute them. I have
computed the probabilities as being 1/2,1/2. If you compute them as
1/3,2/3, then you need to advance a similar computation, and then for
good measure, show me where I erred. Probability calculations are
notorious for their subtleties, so I won't take offence at being shown
wrong. At present, the only argument I can see that gives the
probabilities as 1/3,2/3 is the one based on the strong SSA - (your
point 4) - an assumption that I reject.

A reverse causality type of argument would assume that you would never
enter branches that have no escape routes. I have toyed with this
idea, but reject it - principally because I have yet to see an example
of a branch with no escape route, so in essence it becomes
meaningless, but if there were such brances - my belief in foward
causality is so strong, I would prefer to question quantum
immortality, than to invoke reverse causality as a way of salvaging

> This is what I believe is probably true. I think that there
> must be a sort of "reverse causality" at work, which would
> increase the measure of the right branch of Jane at time t1
> (the branch that sees heads, but before the copy is made).
> This still has Jacques' problem of allowing pseudo-zombies.
> If we switch to Jacques' example and assume two copying events,
> then the Jane on the left branch, at time t1, would have less
> measure than the Jane on the right (note the contrast between
> this result and the previous, where the Janes that were the
> product of the second copying operation were accorded less
> measure).
> But I don't see this as a problem. What I'm suggesting is that
> each human alive today has a varying amount of "measure". It's
> incorrect to assume that each person, when they are born, is
> given a single "measure unit". By my scheme, a person with a
> terminal illness with only a few days to live would have a
> very small measure of existence, relative to others.
> I can't help wondering, often, why I find myself to be the
> particular human I am. Do you others wonder this? One thought
> I've had (please don't laugh at me too badly) is that the fact
> that I have a pretty poor memory might be significant. If I
> had a better memory, then my measure would be less, because
> fewer universes could have given rise to me. Of course, this
> reasoning probably won't work for you, but that doesn't make it
> any less valid from my perspective, which is the only one I
> have.
> I came to believe in this "reverse causality" while pondering
> the QS project I wrote about before. I started to expect that
> things would crop up in my way to prevent my being able to
> complete the project, before it came to fruition. It didn't
> (and it still doesn't) make sense to me that the measure of all
> my branches should be unaffected until the very instant that I
> carry out the experiment. Because if the assumption that I'll
> be alive after the experiment date is correct, then I can expect
> to have memories at that time of somehow having escaped. And
> I should, in general, expect to have a memory of "the most
> likely" escape route, or of one of the most likely ones, if there
> are several that are near-equally likely.
> But how can one reconcile that with the concept of continuity of
> consciousness from moment to moment? Only if there is a reverse
> causality at work.
> This theory has significant and testable implications. Viz: we
> should expect to find ourselves in a universe that will allow us
> to live forever. I.e. this leads directly to the requirement
> that the FAP is true. Just consider if time t1 and t2 are
> separated by a larger and larger time span. Consider also that
> those branches in which we cease to exist also tend to decrease
> the measure of all the observer-moments in previous subjective
> time.

True, although it is a very weak requirement. It certainly does not
imply the existence of an Omega point. That it doesn't contradict the
existence of such a point is also illustrated by the Tiplerian type

> Basically, the measure of our observer-moments at the next
> instant in subjective time are weighted as the number of continous
> paths from that observer-moment to the "Omega-point". This is
> my crackpot theory. Though it's certainly hard to justify on the
> basis of the SSA on a moment-by-moment basis (the Strong SSA), I
> haven't yet found anything that contradicts it. I know that's
> not good enough, but anyway I find it the most satisfying
> result of the above thought experiment. All the other possibilities
> are problematic.
> --
> Chris Maloney
> "Donuts are so sweet and tasty."
> -- Homer Simpson

Dr. Russell Standish Director
High Performance Computing Support Unit,
University of NSW Phone 9385 6967
Sydney 2052 Fax 9385 6965
Room 2075, Red Centre
Received on Sun Aug 15 1999 - 20:14:48 PDT

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