[Serious Phil] computationalism

[Peter D]

--- In Phil-Sci-Mind at yahoogroups.com, "larry_tapper" <Philscimind at ...> wrote:
>
> Eray writes:
> 
> EO> ...Famously, the famous theorist Martin Davis had written a blowing critique of these con men...
> 
> Eray,
> 
> I want to mention that a Davis article criticizing Siegelmann as well as Copeland is available online: 
> 
> http://www1.maths.leeds.ac.uk/~pmt6sbc/docs/davis.myth.pdf
> 
> An extremely readable article given the technical content. Davis is one of my heroes. As of a few years ago, he was an active contributor to the Foundations of Mathematics discussion group. Have you corresponded with him there or elsewhere?
> 
> The point you're making here is in a way the opposite of the one SWM brought up. He thought there were computer scientists who were pessimistic about the prospects of computational AI on some sort of theoretical grounds. Here you are criticizing computer scientists who are overly *optimistic* about achieving incredible computing power through "hypercomputation". 
> 
> The underlying general issue, which you have brought up at various times in Analytic, is whether the non-computable reals have any place in physical theory. I think Davis makes a persuasive (though informal) case that they do not. This makes sense to me intuitively --- it is hard for me to see not only how radically infinite precision would be attainable, but also how it could make any difference in our understanding of physical systems. 
> 
> Larry

Caveat: I haven't read the Davis paper.
Comments:
If infinite precision is obtainable, it is obtainable. If you think of
the universe as a computer, then it is hard to see how it comes up
with inifinte precision. But then there is not the slightest apriori
reason to think the universe is a computer. And, there is still a puzzle about how it instantaneously comes up with *computable*
reals, since computers can only compute a prefix in finite time.

"    It always bothers me that, according to the laws as we understand them today, it takes a computing machine an infinite number of logical operations to figure out what goes on in no matter how tiny a region of space, and no matter how tiny a region of time. How can all that be going on in that tiny space? Why should it take an infinite amount of logic to figure out what one tiny piece of space/time is going to do? So I have often made the hypotheses that ultimately physics will not require a mathematical statement, that in the end the machinery will be revealed, and the laws will turn out to be simple, like the chequer board with all its apparent complexities"
--R Feynman.