Re: Is the universe computable?

From: Georges Quenot <>
Date: Fri, 09 Jan 2004 09:45:07 +0100

Bruno Marchal wrote:
> At 11:34 08/01/04 +0100, Georges Quenot wrote:
> >I am very willing (maybe too much, that's part of the
> >problem) to accept a "Platonic existence" for *the* integers.
> >I am far from sure however that this does not involve a
> >significant amount of faith.
> Indeed. It needs an infinite act of faith. But I have no problem
> with that ...

Unfortunately, it seems that some people do.

I am not sure how much I share that faith. As I mentionned,
I am willing to but since I could not find some ground to
support that willingness, I might be a bit agnostic too.

> >There are some objections to
> >it and I am not sure that none of them make sense. Also, as
> >someone said (if anybody has the original reference, in am
> >interested): the desire to believe is a reason to doubt.
> >I think that, even if it is true, arithmetic realism needs
> >to be postulated (or conjectured) since I can't figure how
> >it could be established.
> All right. That's why I explicitly put the AR in the definition of
> computationalism.
> About your question "is the universe computable?" the problem
> depends on what you mean by "universe". The definition you gave recently
> are based on some first person point of view, and even that answer does
> not makes things sufficiently less ambiguous to answer. Don't hesitate
> to try again.

I have no problem with definitions that inculde "some first
person point of view". I do not find them so "first person
point of view" since I believe that every person I can talk
with, using the same "first person point of view", would see
the same universe. We could at least say "the universe" in
a consistent way among us. I might try again but I would
like first to see what others have to say on the subject
(to get an idea of in what direction I would need to make
things clearer).

> You can also read my thesis which bears
> on that subject (in french).

Yes. I have found the reference too. One of my next readings
I think (though I have a pipe quite full...).

> You may be interested in learning that at least
> the *physical* universe cannot be computable once we postulate the comp
> hypothesis (that is mainly the thesis that "I" or "You" are computable; +
> Church thesis + AR). The reason is that with comp, as with Everett
> (and despite minor errors in Everett on that point), the traditional
> psycho-parallelism cannot be maintained. See my URL below for more.
> Why there is no FAQ? Because we are still discussing the meaning of
> a lot of terms ....

I saw some posts on tentative glossaries of acronyms. Maybe
before complex terms, we should focus on "basic" ones like
"universe". I would not be upset to encounter definitions
for several possible senses of that word.

> Welcome,


Received on Fri Jan 09 2004 - 03:46:15 PST

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