From newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.ecf!utgpu!cs.utexas.edu!uunet!trwacs!erwin Tue Apr  7 23:22:04 EDT 1992
Article 4697 of comp.ai.philosophy:
Path: newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.ecf!utgpu!cs.utexas.edu!uunet!trwacs!erwin
>From: erwin@trwacs.fp.trw.com (Harry Erwin)
Newsgroups: comp.ai.philosophy
Subject: Re: Infinite Minds?
Message-ID: <524@trwacs.fp.trw.com>
Date: 24 Mar 92 18:51:35 GMT
References: <1992Mar21.024804.10085@husc3.harvard.edu> <1992Mar23.171539.27586@cs.ucf.edu>
Organization: TRW Systems Division, Fairfax VA
Lines: 35

clarke@acme.ucf.edu (Thomas Clarke) writes:

>Consider the propositions:
>...
>C.   Physics can be reduced to an effective procedure.  That is an effective  
>method exists for computing the results of a given experiment to arbitrarily 
>small accuracy.  

Three comments come to mind:

1. Reducing physics to an effective procedure is equivalent to
constructivizing physics (in the sense of Broewer and Bishop). Although
they were successful in constructivizing a major subset of mathematics,
their program had serious difficulties reasoning with infinities (and
hence with real numbers in a general sense). Note that a constructive real
line has a countable number of points. 

2. Chaos and sensitive dependence on initial conditions are known in many
classical and semiclassical systems. Effective methods for computing the
results of a given experiment run into problems when quantum phenomena are
inflated to macroscopic dimensions. Chaos is known in the brain and is
suspected of being involved in efficient pattern matching processes. (Paul
Rapp, and more recently a paper by a number of folks at Stanford, Huberman
and Rumelhart coming to mind.)

3. Quantum phenomena force us to regard the underlying reality as
non-classical. Although this may have no effect at the scale of the brain,
I have seen quantum statistics applied to describing brain function by
analogy.
 
So your points are well-taken.
-- 
Harry Erwin
Internet: erwin@trwacs.fp.trw.com



