Q Wars Episode 10^9: the Phantom Measure (fwd)

From: Russell Standish <R.Standish.domain.name.hidden>
Date: Mon, 24 May 1999 11:49:49 +1000 (EST)

> 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
> interpretation.

I think we're talking about MWI with some additional reasonable
suppositions, the main one being that at each point of every history
containing a live you will have a future history also containing a
live you. Thus even if future histories containing xx old you's are a
vanishing proportion of the total future histories, there is still a
one to many correspondence between now and the future.

> > 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
> purpose.
> - - - - - - -
> 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/

Dr. Russell Standish Director
High Performance Computing Support Unit,
University of NSW Phone 9385 6967
Sydney 2052 Fax 9385 7123
Australia R.Standish.domain.name.hidden
Room 2075, Red Centre http://parallel.hpc.unsw.edu.au/rks
Received on Sun May 23 1999 - 18:49:06 PDT

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