srn347 comments on Math is Subjunctively Objective - Less Wrong

14 Post author: Eliezer_Yudkowsky 25 July 2008 11:06AM

You are viewing a comment permalink. View the original post to see all comments and the full post content.

Comments (116)

Sort By: Old

You are viewing a single comment's thread. Show more comments above.

Comment author: Qiaochu_Yuan 01 January 2013 04:28:27AM *  1 point [-]

How would the world look different on each of those hypotheses? (Can you please taboo "fundamental" and "exists," too?)

Pythagorean theorem clearly seems to be a property of the real world, as does pi, and geometry in general.

You're confusing the map and the territory here. The Pythagorean theorem and pi are both mathematical features that fall out of a particular model of the world, namely Euclidean geometry, which is an inaccurate model for at least two historically major reasons (the Earth not being flat and relativity).

Comment author: [deleted] 01 January 2013 04:41:22AM -2 points [-]

Actually, the pythagorean theorem and pi still apply regardless of what dimension of geometry the world obeys (3-dimensional newtonian physics, 4-dimensional relativistic spacetime, 11-dimensional string theory, etc).

Comment author: Qiaochu_Yuan 01 January 2013 04:49:13AM 0 points [-]

I don't know what you mean by that.

Comment author: [deleted] 01 January 2013 05:44:12PM 2 points [-]

The Pythagorean theorem doesn't apply to curved space, only to flat space (regardless of number of dimension). And pi is the number 3.14159..., which can be defined in ways that have nothing to do with geometry, so I'd put it as "in convex (concave) space, the ratio of a circumference to its diameter is less (greater) than pi", not as "in convex (concave) space, pi is less (greater) than 3.14159...)".