The emotional experience of mathematical elegance. A new study by the perceptual neurobiologist Semir Zeki and the great mathematician (& Fields Medalist) Sir Michael Atiyah examines fMRI scans of mathematicians viewing formulae which they'd previously rated as beautiful or ugly, and reports that mathematical beauty elicits activity in the same brain regions as great art or music.
Mathematical proofs in sanus, with some visualization from Martin Wattenberg's The Shape of Song. "The music here...is a raw and unadorned representation of the mathematics itself, involving few human preconceptions beyond a basic mapping needed to accommodate the Western tonal scale."
Prime Time. A prime is a whole number divisible only by itself and 1. In Aesthetics of the prime sequence one can hear primes, view primes (here also) and test for primes. Quite interesting and not just for math geeks...