Re: A nerw idea to play with

From: Marchal <marchal.domain.name.hidden>
Date: Mon Sep 6 06:40:18 1999

> Gilles Henri wrote:
>For me digital systems are systems whose some characteristics (description
>and evolution of their "state") are EXACTLY equivalent to a TM. All our
>computers are obviously of this type. All systems that are not known to be
>digital must be considered as analogical (in fact they are all analogical
>at another level of description). The burden of proof is for the
>demonstration of "digital character", the default value being analogicalness.

Do you think that a distance of 10^-500 has a accepted meaning for any
physicist. Some physicist and mathematician believe that "analogical"
system are "idealisations". At least with the "digital" there is Church
Thesis which makes things clearer.

>I do not know any description of our brain that is obviously exactly
>equivalent to some TM. I would be very happy if someone in this group
>could give me one.

Any reasonable quantized version of Schroedinger equation. Nobody has ever
proved the necessity of non-computable real numbers there. Only Penrose
seems to search non-computability there, for rather obscur reasons.

>Independantly of the practical possibility, I see no reason why duplicated
>people would fail the Turing test.

I see no reason too. Comp is indeed the hypothesis that duplicated people
are equivalent from their first person point of view.
Well, of course comp ask for a digital truncation.

>I agree completely with you- comp2 is actually the hypothesis that the
>computation of the physical properties of an analogical machine (e.g. our
>brain) can emulate this machine from the first person point of view.

I don't understand. Comp need the digital "approximation".
The discussion here will be impossible if you don't tell me precisely what
is an analogical machine, without using the vague "continuum feeling"
which
is what I want to explain.

All what I say is that IF comp is correct THEN

   1) There is no need to postulate the existence of a substancial
universe,
   2) There is a simple explanation (WTP) why we 'see' many universe.
(WTP =
      the Weak Turing-tropic Principle)
   3) The idea that we can disappear (die) can only be whishfull thinking
   4) ALL physical predicate are computationnal modalities, and ALL
physical
      laws are deducible from computer science/number theory.

It is still possible that IF comp is correct THEN there are flying
rabbits
or just Noise, etc. (So that comp would be refuted).

I like COMP because it makes possible to work with a concrete plenitude
principle (George Levy term), and it implies (easily) apparent
indeterminism,
non-locality, and our belief in the continuum.

And if you take a substancial continuum for granted (like Penrose), then
OK,
comp must be false for you. I have no problem with that.

The problem exists only for people (the majority!, perhaps not in
this list), who believe (implicitly or explicitly) in comp AND who believe
at the same time in a "physical substancial material" Universe.

The problem (misunderstanding) between us is not philosophical but
methodological. I don't want to defend comp, just to put it toward its
logical
limits.
If we ever find a real contradiction in comp, we will be both winner here.
But we must not confuse the strange with the absurd, or the
counter-intuitive
with the contradictory.
And untill now, comp seems to be confirmed by the facts (cf QM, MWI, etc.)

Bruno.
Received on Mon Sep 06 1999 - 06:40:18 PDT