Re: [CL] The Decidability Fetish
Thus spake John F. Sowa at 6:51 pm -0700 on 25-08-04 re Re: [CL] The
Decidability Fetish:
> PH> Wrong on two counts. First, it is not true that every
> > segment of a tea party is a tea party. Second, it is not
> > obvious (and indeed I think it is false) that time is
> > in fact a mathematical continuum. It is certainly false
> > that what one might call conceptual time is a continuum.
>
> I agree with Pat about tea parties: the act of stuffing
> the dormouse into the tea pot may be part of a tea party,
> but it is not, in itself, a tea party.
And I strongly agree that time is *NOT* a mathematical continuum. Several
years ago I had written up a sketch of how it could be better modelized as a
*sheaf*.
More generally I believe we need to review many, many items modelized by
Physics: the "material point" (inexistent, only parts of space-time have
meaning), the use of the real line $R$ (not only for time but for everything
"measurable"), etc, etc.
As a matter of fact it would be worth the trouble to abandon Set Theory and
replace it with Topos Theory -- a start has already been made by Lawvere but
it's a major undertaking demanding a team not a mere individual.
> John
Cheers
P.S. why do I only get John's response and not the original mail to the list?
--
Michel Eytan eytan@umb.u-strasbg.fr
I say what I mean and mean what I say