Russell, here we disagree. A billion-year-old man has no more evidence of
MWI than do his young contemporaries.
James
> -----Original Message-----
> From: Russell Standish [SMTP:R.Standish.domain.name.hidden]
> Sent: Monday, May 17, 1999 2:36 AM
> To: everything-list.domain.name.hidden
> Subject: Re: SSA (fwd)
>
> >
> > On Thu, 13 May 1999, Russell Standish wrote:
> > > everything-list.domain.name.hidden
> >
> > What's that?
>
> A typo :)
>
> > >
> > > It is hardly nonsense. The predictions can easily depend of the
> > > 'picture' but must be consistent with each other. Let me give a simple
> > > example:
> > >
> > > In one picture, observer A decides to measure the spin of an electron
> > > in the x direction. In the other, observer B decides to measure the
> > > spin of the electron in the y direction. Observer A will see the spin
> > > of the electron aligned with x axis, and Observer B will see it
> > > aligned with the y axis. Both observations are correct in the first
> > > person picture of that observer. A "person" with the third person
> > > perspective, sees observers A and B as inhabiting separate `worlds' of
> > > a multiverse, each with appropriate measure that can be computed from
> > > Quantum Mechanics.
> >
> > On the contrary, this is a textbook example of the way I said it
> > works. The theory predicts some measure distribution of observers; an
> > individual observer sees an observation drawn from that distribution.
> > There are no different sets of predictions for different pictures, just
> > the measure distribution and the sample from it.
>
> It sounds to me like you don't think the prediction changes according
> to what the observer chooses to observe? An electron cannot have its
> spin aligned with the x axis and the y axis at the same time. Once the
> experimenter has chosen which direction to measure the spin, the
> history of that particular is observer is constrained by that fact,
> and the predictions of QM altered accordingly. This is true both in
> MWI and the Copenhagen interpretation, and is the "spooky" nature of QM.
>
> I used to think that QM gave predictions in terms of distributions,
> and that because one didn't see isolated particles, rather ensembles
> of such particles, I didn't see a problem. The properties of an
> ensemble are well defined.
>
> However, the ability of experimenters to isolate a single particle,
> such as a photon, or an atom, means we have to take this "spookiness"
> seriously.
>
> >
> > > > A theory predicts some measure distribution on the space of
> > > > conscious observations. From the point of view of an observer, you
> see
> > > > one observation drawn from that measure distribution.
> > > > If measure were conserved for a particular individual as a
> > > > function of time, you immediately have 2 problems:
> > > > - How to define a particular individual? You need to, or else
> the
> > > > measure of other people would count too, and would stay relatively
> > > > constant as opposed to the rapidly diminishing measure of "you".
> > >
> > > This is a furphy. I have no problem whatsoever in knowing that I am
> > > who I am. If you are unsure of your identity, then that's your
> problem.
> >
> > Nature must have a mathematical criterion for it, if it is going
> > to figure in a theory of physics.
> >
>
> Quite agreed. However, I don't believe this to be much of a
> problem. Most mathematical treatments of such take it to be some kind
> of projection operator.
>
>
> > > > - The expected value of your age would be infinite, contrary
> to
> > > > observations which indicate no unusual age on your part.
> > >
> > > Again this is based on an assumption that at each time period,
> > > conciousness must select randomly from the set of available conscious
> > > moments for that observer. (ie SSA of all concious moments, as opposed
> > > to SSA of birthdates). As I mentioned earlier, I reject this
> > > assumption as absurd, and prefer the view that conciousness must sweep
> > > out the concious moments in the time order they are arranged, ie I
> > > must pass through being 30 years old before I can experience being 100
> > > or 1000 years old. Therefore being young with respect to average
> > > lifetimes is not contradictory with expecting an infinite lifetime. I
> > > would be very surprised if conciousness jumped from 30 yo, to 100yo
> > > back to 10yo etc in some unordered random fashion, but of course have
> > > no way of exactly disproving it.
> >
> > The above paragraph is rather meaningless since you haven't
> > defined 'yourself'. If 'you' are some extended implementation of a
> > computation, you are not immortal: the number of implementations will
> > decrease over time. I take one time step as the most logical unit but
> > that is irrelevant to the conclusion.
> >
>
> This para still indicates that you are falling for this rather absurd
> sampling assumption mentioned above. Give me one good reason why you
> would expect conciousness to sample randomly from the set of all such
> "concious points", rather than in an ordered (and potentially
> unbounded) sequence of self-consistent points (ie a history).
>
> > From: Higgo James <james.higgo.domain.name.hidden>
> > Subject: RE: SSA
> >
> > >Jacques wrote:
> > >> Are you saying that the MWI does not predict immortality, or that
> > >>a single world theory does predict it? The former would make sense
> > >>since immortality is observationally false, but I didn't think you'd
> > >>come around so easily.
> >
> > > Good grief, Jacques - for the umpteenth time: of course it does not
> > >predict immortality any more than classical physics does. But you will
> > >end up as one of those exceedingly unlikely, one in
> 10E500000...Jacques's that
> > >happen to survive for an aeon. Even then you will have no better proof
> of
> > >MWI than you do now.
> >
> > Let me get this straight. It doesn't predict immortality, but it
> > does; I will find myself to be old due to the MWI, but since it's not
> > really a prediction of the MWI I won't have evidence for the MWI based
> on
> > that. Your doublethink continues to amaze me.
> >
> > > Immortality is no more 'observationally false' than the statement
> > >'you will become a petunia in six minutes'. After six minutes, you may
> > >challenge that statement (in those universes in which you are not a
> petunia
> > >and have not lost your power of communication in another way). And
> after
> > >infinity you may challenge my statement that you are immortal.
> >
> > Ever hear of statistics? All use of empirical evidence is based
> > on it.
> >
> > > If anything, the fact that you are alive lends support to the
> > >hypothesis that you will not die. You have never been observed to die
> in
> > >the past.
> >
> > That's the kind of Basic Stupidity (BS) that undeservedly gave
> > induction a bad name. I've had enough of your BS.
> >
>
> I think the above few arguments are floccinauccinihilpilication. Yes,
> living to ages much larger than human average would be empirical
> support of QTI, at least for the person so involved. However, you
> would probably have a hard time convincing all the other individuals
> (who would probably be aged 0-100 years, assuming no great advances in
> Medicine).
>
> Of course someone may come up with mathematical theorem limiting human
> lifetime - this is about the strength of what is required to disprove QTI.
>
> The "observationally false" statement that Jacques makes is based on his
> ergodic SSA on concsious sampling. As I stated earlier, I find this
> difficult to believe, and Jacques obviously finds it so obvious that
> he doesn't feel the need to defend it.
>
>
> Cheers
>
> --------------------------------------------------------------------------
> --
> 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 Mon May 17 1999 - 11:18:33 PDT