Yes, except for imaginary numbers.-) Didn't we discuss a popular book (movie?) about this a few years ago? Geometry (e.g. gosper.org/perigal.gif ) makes it real for me. --rwg On 2018-04-02 09:47, Tomas Rokicki wrote:

Mathematical truth is as real as the fact that we have one sun and seven continents, that a coin has two heads

Oops, a counterexample. This proves that mathematicians cheat. Except those with two heads. and that Pi is about

3.1415. That is, mathematical truth is as real as anything else.

It's certainly as true as molecular biology!

-tom

On Mon, Apr 2, 2018 at 9:42 AM, Dan Asimov <dasimov@earthlink.net> wrote:

...

If this common discussion subject among mathematicians has come up in math-fun previously, it must have been a while ago:

Is mathematical truth real? I was reminded of this question when I happened to sit next to an esteemed molecular biologist who has strong opinions on the matter: He thinks math is "all in the brain" of humans who think about it. I could not convince him that math has any kind of independent existence — though I certainly believe it myself.

What do other think about this? I would say that mathematical truth is *at least* as real of a thing as physical truth.

—Dan