On 05 Mar 2012, at 19:26, meekerdb wrote:

On 3/5/2012 10:03 AM, Evgenii Rudnyi wrote:On 05.03.2012 18:29 meekerdb said the following:On 3/5/2012 3:23 AM, Evgenii Rudnyi wrote:The experiment takes an operational approach to what Pi means. During the initial stage of the experiment mathematicians prove the existence of Pi.When mathematicians 'prove the existence' of something they are just showing that something which satisfies a certain definition can be inferred from a certain set of axioms. In your example themathematicians may define Pi as the ratio of the circumference tothediameter of a circle in Euclidean geometry. But what does that mean if geometry is not Euclidean; and we know it's not since these mathematicians are in the gravitational field of the Earth. Mathematics is about abstract propositions. Whether they apply to reality is a separate question. BrentI agree that this assumption might not be the best one. I willthink it over.However, I do not completely understand you. How the geometry ofphysical space in which mathematicians reside influences thedefinition of Pi? Mathematicians will consider just Euclideangeometry, that's it. In my view, whether the physical spaceEuclidean or not, does not influence the work of mathematicians.Exactly. Hence mathematics =/= reality.

Right. But this does not prove that reality is not mathematical.

In any case, the problem remains. What is mathematics under theassumption of physicalism? Do you have any idea?It's a language game.

`The word "game" is so fuzzy that this says nothing at all. Game theory`

`is a branch of mathematics.`

A physicist goes off to a conference. After a week his suit’s gottensoiled and crumpled, so he goes out to look for a dry cleaner.Walking down the main street of town, he comes upon a store with alot of signs out front. One of them says “Dry Cleaning.” So he goesin with his dirty suit and asks when he can come back to pick it up.The mathematician who owns the shop replies, “I’m terribly sorry,but we don’t do dry cleaning.” “What?” exclaims the puzzledphysicist. “The sign outside says ‘Dry Cleaning’!” “We do not doanything here,” replies the mathematician. “We only sell signs!”--- Alain Connes, in Changeux

`Connes is a mathematical realist. Are you sure the joke is not from`

`Changeux who is strongly physicalist?`

Bruno http://iridia.ulb.ac.be/~marchal/ -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.