RE: valuable errors

From: Gilles HENRI <Gilles.Henri.domain.name.hidden>
Date: Tue, 20 Apr 1999 11:58:32 +0200

>Gilles,
>Whatever exists in reality can be simulated by a universal Turing machine.
>All you need is sufficient power to simulate exactly the environment
>required - including the entire weather system of the Eartyh if you believe
>that's necessary. I built an arificial neurone out of integrated circuits in
>1984; I have no doubt that if I had enough of them I could simulate myself
>to an arbitrary degree of accuracy. To deny this is to bring in sprit by
>another name.
>James

You are right in principle. What I am saying is that "sufficient power" is
in fact impossible to get in our real world, unless you use the exact
physical copy (may be this could be used as a definition of living
organisms?).The Universal Turing machine which is necessary to simulate the
entire environment should be bigger that the Universe itself, which in
practical impossible to realize. (as an order of magnitude, most powerful
computers can simulate around 10^6 CLASSICAL particles. The full quantum
calculation of THREE atoms has not been done yet. We are made of around
10^28 atoms. The Earth has around 10^48 atoms). So the simulation you
imagine should take place in a larger meta-Universe. Worse: what you
propose is NOT Bruno's thought experiment (duplication in our physical
Universe). Again you are an open system connected with an external
Universe, and again YOU (as a human person) are defined by this
interaction. I don't know if you are married, but if yes, I doubt that you
wife (or any relative) would have accepted to replace you with your
computer even very sophisticated? (of course you could try to simulate her
in your computer, but again it is NOT Bruno's experiment).

You should not underestimate the importance of practical feasibility of
experiments. Relativity and QM are both based on the practical
impossibility of some measurements (absolute motion or simultaneous
position and momentum measurements).
It is not assuming spirit that saying that some features can only be
realized by particular physical systems, and that these conditions can
become so stringent that these systems can happen to be unique. I am
confident that computer science will eventually built intelligent machines,
maybe with neural networks. What I think is that these machines will never
(and cannot) be YOU. They will be other, unique individuals. This is
because the existence of consciousness (which I think IS a physical
process) implies fundamentally the representation of yourself in the space
and the time, which makes you unique.


Gilles
Received on Tue Apr 20 1999 - 02:59:52 PDT