Q Wars Episode 10^9: the Phantom Measure

From: Jacques M Mallah <jqm1584.domain.name.hidden>
Date: Sat, 22 May 1999 17:40:20 -0400

On Thu, 20 May 1999, Gilles HENRI wrote:
[Jacques Mallah wrote]
> > And there's the proof of my above statement.
> > Wei Dai has previously argued that the 'quantum suicide' crowd
> >really just had a weird sense of morality regarding measure, rather than a
> >wrong view of the math. I think the above proves that not to be the case:
> >since Higgo now thinks that being old would be evidence of QTI, that
> >proves that he does believe that the predictions of QTI would not be the
> >standard predictions of QM as Wei and I understand it.
> > I find it incredible that Higgo can state that being old would be
> >statistical evidence for QTI, since one would not expect that without
> >QTI, but still not realize that being young is statistical evidence
> >against it.
> Jacques, I agree with James.
> 1) if you find yourself very old, this is no rigorous evidence for any
> theory. However you should choose the explanation following the maximum of
> likelihood criterium, i.e. the theory in which the probability of being
> very old in some world is maximum. This probability if 1 in MWI, and very
> tiny in conventional QM. So the fact of being very old should be considered
> as a very strong, although not absolute, evidence for MWI. In the same way,
> the thousands of experimental confirmations of QM are very strong pieces of
> evidence for QM, but not rigorous proofs (which do not exist).

        Would you define for me the meaning of your statement that the
probability of you being very old in the MWI is 1?
        It is surely true that in the MWI, old copies of you-like beings
will exist. It is also true that they will be of very small measure, and
that the effective probability of being one of those copies is very tiny.
        Being old is about as unlikely in the MWI as in any other

> 2) The fact of being young is not a statistical evidence against QTI,
> because the number (or the measure) of worlds where you are young is
> actually much larger than that where you are old. If you choose randomly a
> point between the x axis and the exponential curve y=exp(-x), most of your
> points will lie at x of the order of 1, although there exist an infinite
> number of points with x as large as you want.

        You do seem to have some kind of understanding of measure based on
the above paragraph. So why can't you go all the way and repudiate QTI?
No one is suggesting that QTI=false means that no worlds with you-like old
beings exist. Rather, the point is that you should not expect to
experience that in any meaningful sense; most you-like beings are not that
old. More dramatically, suicide is no wiser in the MWI than without it,
since it just reduces your measure and the measure fraction of old
you-like observers.
        Gilles, on other issues we have sometimes agreed. I hope you can
learn to take a more rational look at this issue, and if you are convinced
you might be able to teach the others in a way I couldn't.

From: Higgo James <james.higgo.domain.name.hidden>
Subject: RE: Any hope for Higgo?

>Ja[c]ques writes:
>> I find it incredible that Higgo can state that being old would be
>> statistical evidence for QTI, since one would not expect that without
>> QTI, but still not realize that being young is statistical evidence
>>against it.
>But Jacques does not say what 'old' is. In relation to immortality, 31 is
>neither old nor young; in the same way, in relation to infinity, 31 is
>neither a lot nor a little, any more than 457*10E900 is a lot or a little.

        False. 31 about is what one would expect if QTI were false, no
question about that, since it's within the normal human lifetime as
documented from watching the deaths of others.
        If QTI were true, you should expect to be very much older than
that, at least. The exact age would still seem surprisingly low compared
to infinity, if you had an infinite brain capacity. Luckily (?) you
don't, so you should expect with probability 1 that your age would be too
large for you to remember or even estimate.

>(I assume you are also OK with the notion that there is an infinite number
>of billion-year-old-Jacqueses). Well, then our only disagreement is whether
>you will become an old Jacques. I believe that you only experience those
>universes in which you exist, so you will eventually experience being one of
>those old Jacqueses.

        The above paragraph seems rather meaningless. From what I gather,
you believe that "I" (whatever that means) will experience all me-like
observations in some kind of consecutive order, and that the measure of
such observations will not decrease with time. Quite ridiculous.

>Would you care to offer a non-SSA argument against this (SSA is inapliccable
>to this situation, as I have pointed out, as you are the only immortal and
>therefore not a representative sample).

        "SSA" is merely applying the usual Bayesian proceedure to
incomplete information. It can not be false, even if QTI were true.

From: Higgo James <james.higgo.domain.name.hidden>
Subject: RE: Any hope for Higgo?

>Jacques Wrote:
>> I hope even you have realized by now that an argument against
>>immortality quoted above is that if immortality were true, identity would
>>have to figure in physics. So you are supporting my point above, not
>>opposing it.
>Nonsense. What I am arguing is that we can expect to experience a continuous
>flow of consciousness forever. That does not mean we have an objective
>identity. I am arguing about our experience, which is 100% subjective.

        Again, a meaningless paragraph. My experience consists of one
observation. The collective experiences of me-like beings consists of
many observations most of which are not of being old. Any link over time
between certain of those beings would require an identity criterion, and
if measure was conserved over time within the being that meets such a
criterion, it would require special laws of physics for that special

                         - - - - - - -
              Jacques Mallah (jqm1584.domain.name.hidden)
       Graduate Student / Many Worlder / Devil's Advocate
"I know what no one else knows" - 'Runaway Train', Soul Asylum
            My URL: http://pages.nyu.edu/~jqm1584/
Received on Sat May 22 1999 - 14:41:13 PDT

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