Robert, 

thanks for the additional quotations.  

However, you made a slip of the fingers when you keyed in one of the passages.  
To head off needless controversy, I key it in correctly below.  The capitalized 
word is where the slipup occured.  

"Mathematics as we practice it is much MORE formally complete and precise than 
other sciences, but it is much less formally complete and precise for its 
content than computer programs."
Easy slip to make because of the structure of the sentence. 

n


Nicholas S. Thompson
Emeritus Professor of Psychology and Ethology, 
Clark University ([email protected])
http://home.earthlink.net/~nickthompson/naturaldesigns/
http://www.cusf.org [City University of Santa Fe]




----- Original Message ----- 
From: Marcus G. Daniels 
To: [email protected]
Sent: 12/15/2009 1:09:23 PM 
Subject: Re: [FRIAM] A little Proof, Dr Thurston! It aint Elementary!


On 12/15/09 12:27 PM, Robert J. Cordingley wrote: 
I think this is him:
http://en.wikipedia.org/wiki/William_Thurston

The essay that Russ mentioned only mentions programming in passing..  He 
doesn't say anything about it relative to `intellectual challenge', but he does 
talk a lot about what is the deep value of his enterprise.   The message is in 
some sense that the rigor is not the end, it's the means.  Some quotes:

"When one considers how hard it is to write a computer program even approaching 
the intellectual scope of a good mathematical paper, and how much greater time 
and effort have been put into it to make it "almost" formally correct, it is 
preposterous to claim that mathematics as we practice it is anywhere near 
formally correct.

Mathematics as we practice it is much less formally complete and precise than 
other sciences, but it is much less formally complete and precise for its 
content than computer programs.  The difference has to do not just with the 
amount of effort:  the kind of effort is qualitatively different.  In large 
computer programs, a tremendous proportion of effort must be spent on myriad 
compatibility issues:  making sure that all of the definitions are consistent, 
developing "good" data structures that have useful but not cumbersome 
generality, deciding on the "right" generality for functions, etc.  The 
proportion of effort spent on the working part of a large program, as 
distinguished from the bookkeeping part, is surprisingly small.  Because of the 
compatibility issues that almost inevitably escalate out of hand because the 
"right" definitions changes as generality and functionality are added, computer 
programs usually need to be rewritten frequently, often from scratch."  

and

"The standard of correctness and completeness necessary to get a computer 
program to work at all is a couple orders of magnitude higher than the 
mathematical community's standard of valid proofs.  Nonetheless, large computer 
programs, even when they have been very carefully written and very carefully 
tested, always seem to have bugs."

..and then he goes on to talk about how mathematics lacks a holistic sort of 
factoring process like goes on with large [evolving] programs.  And many other 
interesting, reasonable remarks.
============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

Reply via email to