Re: Is the universe computable

From: Bruno Marchal <>
Date: Wed, 28 Jan 2004 15:27:21 +0100

At 11:57 27/01/04 -0500, Stephen Paul King wrote:

> Thank you for this post. It gives me a chance to reintroduce one
> problem that I have with your model. Like you, I am very interested in
> comments from others, as it could very well be that I am misunderstanding
> some subtle detail of your thesis.
> You wrote:
>"... remembering the comp 1-indeterminacy, that is that if you are duplicate
>into an exemplary at Sidney and another at Pekin, your actual
>expectation is indeterminate and can be captured by some measure,
>let us say P = 1/2, and this (capital point) independently of the time
>chosen for any of each reconstitution (at Pekin or Sidney), giving that the
>delays of reconstitution cannot be perceived (recorded by the first person))."
> Now my problem is that IF there is any aspect of perception and/or
> "observers" that involves a quantum mechanical state there will be the
> need to take the "no-cloning" theorem into account. For example, we find
> in the following paper a discussion of this theorem and its consequences
> for teleportation:

This is a question people ask me often. But not only the cloning theorem is
not a problem with the comp hyp, but actually it is highly plausible the
non-cloning theorem is a direct consequence of comp. Remember that, with
comp, physicalities emerges from an average of an infinity of
computationnal histories: it is a priori hard to imagine how we could clone
that. This is no more amazing than the fact the white rabbit. remember that
with comp, from inside things look a priori not computable. The apparant
computability of the laws of physics is what is in need to be explain with
comp. We should perhaps come back when you have accept all the steps in uda
step by step.

> As a possible way to exploit a potential loop hole in this, I point
> you to the following:
> My main question boils down to this: Does Comp 1-determinacy require
> this duplication to be exact? Is it sufficient that
>approximately similar copies could be generated and not exact duplicates?

It must be exact if the duplication is done exactly at the right level of
substitution (which exits by hypothesis), and can be approximate if some
lower level of duplication is chosen instead.

> How would this affect your ideas about measures, if at all?
> I understand that you are trying to derive QM from Comp and thus
> might not see the applicability of my question, but as a reply to this I
> will again point your to the various papers that have been written
> showing that it is impossible to embed or describe completely a QM system
> (and its logics) using only a classical system (and its logics), if that
> QM system has more that two Hilbert space dimensions associated. Start
> with the Kochen-Specker theorem...

I'm afraid you make a confusion of level here. What KS showed is that you
cannot put a boolean algebra of values to quantum observable pertaining to
some systems. But this is exactly what comp predict for matter and time
notion. That is why we get quantum logics for the first person verifiable
proposition. Nowhere I pretend to recover a classical logic in which
quantum measurement value can be embedded, quite the contrary with comp
classical logic is plainly false for all verifiable 1-notion right at the
beginning. BTW, even if KS was a threat, your argument does not follow
because KS is a theorem in quantum mechanics, and as you say, I just show
that the physics is derivable from comp; if KS is false in the physics
derived from comp then KS would indeed be a problem, but I insist it is
not. It is only the apparent computability of the universe which still
remains the miracle.

My feeling Stephen is just that you don't like comp, and I have no problem
with that. Some people takes my work to be a beginning of refutation of
comp, and perhaps they are right. I want just illustrate that this is not
obvious, and the tiny part of physics I have
extracted from comp is for me just very weird (and no more so I estimate we
are still far from a real reductio ad absurde of comp).
The weirdness is the many world like feature of any comp reality, the non
computability of the physical processes in any reality compatible with
comp, and a sort of quantum logic weaker than usual quantum logic. Is that
so weird? Certainly no more weird than quantum weirdness.

If you are really interested in my reasoning, I would dare to insist going
from step to step. If you prefer not studying the consequences of comp
because you don't have the taste for it, I will not insist at all. My point
is just that comp (that is
          1) there is level of description of me such that I cannot be
aware of functional digital substitution made at that level.
          2) Church thesis
          3) Arithmetical Realism)
   makes the physical science eventually secondary with respect to number
theory/computer science/machine psychology/theology
whatever we decide to call that fundamental field ...

Received on Wed Jan 28 2004 - 12:45:18 PST

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