----- Original Message -----
From: "Lennart Nilsson" <leonard.nilsson.domain.name.hidden>
To: <avoid-l.domain.name.hidden>
Sent: Sunday, June 15, 2003 9:14 AM
Subject: Something for Platonists
> Here is something from David Deutsch for Platonists to contemplate...I
think
>
> LN
>
>
>
> "We see around us a computable universe; that is to say, of all
>
> possible mathematical objects and relationships, only an in.nitesimal
> proportion
>
> are ever instantiated in the relationships of physical objects and
physical
>
> processes. (These are essentially the computable functions.) Now it might
>
> seem that one approach to explaining that amazing fact, is to say "the
> reason
>
> why physical processes conform to this very small part of mathematics,
>
> 'computable mathematics,' is that physical processes really are
computations
>
> running on a computer external to what we think of as physical reality."
But
>
> that relies on the assumption that the set of computable functions - the
>
> Turing computable functions, or the set of quantum computable operations
>
> - is somehow inherently privileged within mathematics. So that even a
> computer
>
> implemented in unknown physics (the supposed computer that we're
>
> all simulations on) would be expected to conform to those same notions of
>
> computability, to use those same functions that mathematics designates as
>
> computable. But in fact, the only thing that privileges the set of all
> computational
>
> operations that we see in nature, is that they are instantiated by
>
> the laws of physics. It is only through our knowledge of the physical
world
>
> that we know of the di.erence between computable and not computable. So
>
> it's only through our laws of physics that the nature of computation can
be
>
> understood. It can never be vice versa."
>
>
Received on Mon Jun 16 2003 - 04:01:54 PDT