I attach Rainer's paper on a proof of MWI
<<plaga test many-worlds.pdf>>
Also a recap of e-mail conversation with Rainer:
Rainer Plaga: On your quantum immortality: you're right about traffic
accidents and the like. But I would guess that the fact that nobody ever
gets older than, say, 300 years is a deterministic law of nature, or in
other words that there is no single branch in which a 300 year old James
exists. Isn't that plausible?
James Higgo: Thanks, Rainer.
The fact that nobody over 300 exists in this universe is
unsurprising. But this is one of quite a few universes. And perhaps they're
hiding. Will you concede there is a one in a thousand billion chance that
you will live over 300 years?
Regards
James
Rainer Plaga: I don't know what the chance for a branch with a 300 year
old James is. But how do you know it is not equal 0?
Rainer
James Higgo: Anything that's possible exists, according to David Deutsch.
Sorry to appeal to his authority.
James
Rainer Plaga: Yeah, anything *that's possible* but I guess nobody knows
whether a 300 year old James *is possible* according to the laws of nature.
Rainer
James Higgo: But it's possible that all the molecules in my body just
rearranged themselves by chance into the form of a teapot, so it's certainly
possible that you don't die.
James
Rainer Plaga Hello James,
I see what you are saying now. Probably you are right. Unfortunately
even when we're 300 years old we will have a hard time to convince our
fellow ``branchians'' that the reason for our extreme longevity is MWI!
(Analogous to Max's experiment). Could there be something extremely
improbable that led to the survival of the human race? (Your idea's analogy
to my A-bomb experiment) An example would be: if we could prove that it is
extremely improbable that a time span of 70 million years goes by without a
nearby supernova that would wipe out the human race. This would be an
argument in favour of MWI. This was only an example, one can show that it
is quite probable that no nearby SN happens within 70 million years.
But perhaps we can find an example that works. Actually: this would
also explain the absence of extraterrestrial intelligence (Fermi's paradox).
All the best Rainer
James Higgo: Some fine ideas. So I take it you're a convert, O Immortal
one!
James
Rainer Plaga: I believe
Actually there is a corollary: It is impossible to commit suicide.
Each time you try you will find that some stupid accident or strange
improbable force kept you from doing it.
Rainer
James Higgo: Absolutely. And you will miraculously survive terminal
cancer.
Rainer Plaga I think Henri's point is correct. When we say
``immortality'' this is probably not age=infinity but age=large number.
However this is very speculative you come into questions like the heat death
of the universe etc.
For me these questions are not so pressing, as the pressing
question: Is MWI true? We have to find tests! Somebody who has a proof that
tests are impossible should publish it. (If the proof is convincing MWI will
become ``many words'' for me).
A last point: You only focus on the positive. Tomorrow I'll go on a
plane. If MWI is true some fraction of me will go through the agony of a
drawn out plane crash.
Rainer
James Higgo Yup. You will crash. Sorry. If you're coming to London give
me a call. On Henri's point, we have finite number of atoms, but I am not
certain that there is a finite number of configurations for those atoms in
relation to their environment. You must be a positivist if lack of proof
will cause you to discount MWI. As Goedel showed, many true hypotheses are
unprovable.
James
Rainer Plaga >On Henri's point, we have finite number of atoms, but I am
not certain that
>there is a finite number of configurations for those atoms.
Yes, that's a very difficult question. There is an article by
F.Dyson on RevMod Phys ca. 1979 whether life ever has to stop in an
expanding universe and he reaches the conclusion that it does not have to.
>As Goedel showed, many true hypotheses are unprovable.
OK, true in principle. I have only a very modest question: Can one
get experimental evidence for the existence of other branches? (In last
consequence this means communication). This is most important question in
physics, I feel. There are two answers possible in principle:
a. this is impossible in principle because...
There is no paper which evens aims to give such a proof. Max thinks
this is true but without giving a demonstration.
b. the simplest device possible for this feat is...
David Deutsch gives a very scifi device which is certainly
nonrealiszable in the immediate future.
I can't understand why people who favour MWI do not agree on the
importance of this question. Even I my proposal is wrong, and a correct
proposal would be much more difficult to realize: the exp. proof of parallel
branches is clearly more important than the exp. detection of a Higgs boson,
so about 5 billion $ would not be too high a price to realize such a
proposal. The fraction of myself that will die tomorrow says goodbye, it was
nice to have made your email acquaintance.
Rainer
James Higgo Perhaps we believe MWI so strongly that we're not so
determined to prove it. Eventually everyone will accept it anyway as it is
the most elegant, simplest and most consistent (with my world-view)
interpretation. Enjoy the trip.
> -----Original Message-----
> From: Gilles Henri [SMTP:Gilles.Henri.domain.name.hidden]
> Sent: 23 November 1998 12:42
> To: everything-list.domain.name.hidden
> Subject: How many mind states?
>
> >Yup. You will crash. Sorry. If you're coming to London give me a call on
> >0171 337 3760.
> >On Henri's point, we have finite number of atoms, but I am not certain
> that
> >there is a finite number of configurations for those atoms.
>
> In my opinion, brain states are highly degenerated in the sense that
> typical mind states are probably linked to macroscopic neural states,
> corresponding to many microscopic configurations. It is further probable
> that many neural states can correspond to the same apparent mind state,
> since we are continuously (in most worlds!) loosing a lot of neurons
> without suffering dramatical consequences. As we have around 10^10
> neurons,
> I would guess that the total number of mind states would be lower (and
> probably much lower) than 2^(10^10), many of them not corresponding to
> sensible thoughts. This would let some room for the memory of a very long
> life, but not for an infinite one...
>
>
>
> >> For me these questions are not so pressing,
> >> is the pressing question:
> >> Is MWI true?
> >> We have to find tests!
> >> Somebody who has a proof that
> >> tests are impossible should publish
> >> it. (If the proof ios convincing
> >> MWI will become ``many words'' for me).
>
> In my opinion again, the difficulty of "proving" MWI is that genuine
> quantum effects are only visible in interference terms, as the decoherence
> theory tells us. That's why Tegmark's suicide experiment, although correct
> in the MWI, can not be considered as a proof of it, even in the worlds
> where the experimentalist survives. As already mentioned, it could be
> merely considered as the realization of a very unlikely probability, which
> is also compatible with the wave function collapse interpretation. The
> only
> proof of MWI would be by a statistically significant deviation from the
> classical evolution after a measurement, due to interference with the
> "ghost" universes which are supposed to have disappeared in the WFCI. It
> should be reproducible in any world (some kind of macroscopic Aspect's
> experiment). Unfortunately, the decoherence theory tells us that these
> deviations are VERY VERY small, so I cannot figure out how to make them
> significant... The best argument for MWI is still that of logical
> self-consistency. Well, we are quite confident that gravitational waves do
> exist, although nobody has been able to detect them up to now!
>
> Gilles
>
>
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Received on Mon Nov 23 1998 - 07:18:49 PST