Beauty May Be More Than Just in the Eyes of the Beholder

Scientific American reports on how Equations Are Art Inside a Mathematician’s Brain.

When mathematicians describe equations as beautiful, they are not lying. Brain scans show that their minds respond to beautiful equations in the same way other people respond to great paintings or masterful music.

And more than that, most mathematicians agree on which equations are ugly and which are beautiful. The most beautiful was Euler's identity:

Why is it the most beautiful?

"Here are these three fundamental numbers, e, pi and i," Adams says, "all defined independently and all critically important in their own way, and suddenly you have this relationship between them encompassed in this equation that has a grand total of seven symbols in it? It is dumbfounding."