Re: Turing vs math

From: Jacques M. Mallah <>
Date: Thu, 4 Nov 1999 15:52:08 -0500 (EST)

On 4 xxx -1, Marchal wrote:
> Jacques M. Mallah wrote:
> >On 2 Mar -1, Marchal wrote:
> >> Take the self-duplication experiment as a simple illustration, where
> >> after having been read I am reconstitued at two different places.
> >> Nobody (not even God) can compute where I will find myself after the
> >> duplication.
> >
> > That has nothing to do with computability! The fact is, depending
> >on how 'you' is defined, you are either at BOTH places, or at NEITHER
> >place!
> That has nothing to do with computability, but that has a lot to do
> with the computationalist hypothesis: the hypothesis that there is a
> level of description such that I survive a (finitely describable)
> digital functional substitution at that level.
> Now you are partially right. But you should have said: ``The fact is,
> depending on how 'you' is defined, you are either at BOTH places, or
> at NEITHER place ... OR at one or the other place".

        If the definition alone does not determine which one; and if there
are no additional mind-like hidden variables; then it must be BOTH or
NEITHER. OR would not be possible.

> Precisely: if you survive classical teleportation, you survive classical
> duplication. OK ? (this need a minimal amount of folk-psychology).
> Now if you define ``you" by the 3-person description of your body at
> the correct level of description then indeed you will be at BOTH places.
> If you define ``you" by an owner of your personal historical-memories
> (such as those you would put in a diary), i.e. what I call the 1-person,
> then after the duplication one of such ``you" will write in (each)
> diary book either ``I am in Washington" (let us say), and the other
> ``you" will write ``I am in Moscow".
> No 1-person will write ``I am simultaneously" at Moscow and Washington.

        It's not a question of writing. Depending on the definition of
'you', there is no reason 'you' can't write both statements.
        What you are trying to get at is the fact that a conscious
observation will only be of one memory or the other. Depending on the
definition, 'you' have BOTH those observations, or NEITHER (in which case
two NEW 'yous' can each have one) .

> It is easy to show that before the duplication the result of the 1-self
> localisation experience after the duplication is totaly undetermined.
> That is what I call the comp-indeterminism.

        There's nothing random about it at all.
        It is, of course, true that for practical purposes you can treat
it as random, so it is effectively random.

> And that is a major step in my argument that IF we are digitalisable,
> then the physical sciences are reducible to the psychology of
> digital machines. In particular quantum indeterminism will be
> explained by the comp-indeterminism.

        I would say: the illusion of randomness in QM will be explained as
effective randomness, not randomness.

> With an ad hoc definition of ``you", you can be at NEITHER place. But
> with comp this amount to say that ``I" totaly disappear at each instant.
> It means that my expected life duration is O second.
> In that case I would prefer to abandon comp, for I take it for sure
> that I have been living for at least 2 seconds.

        That is the simplest definition of 'you' and to prevent all these
arguments and misunderstandings, I think it is best to always use that
definition. If that makes you abondon comp, all I have to say is that
only a fool would change his beliefs about the actual world just because
of the definition of a word used to discuss it.

                         - - - - - - -
              Jacques Mallah (
       Graduate Student / Many Worlder / Devil's Advocate
"I know what no one else knows" - 'Runaway Train', Soul Asylum
            My URL:
Received on Thu Nov 04 1999 - 12:56:28 PST

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