Beauty and ugliness

Via BoingBoing comes this gallery of mathematical art from Justin Mullins. Each piece of art is a mathematical concept or set of equations, with an evocative title. I enjoyed browsing the gallery, and even reading the liner notes below each picture.

The first two in the gallery are Beauty and Ugliness. Beauty is represented by the famous equation

e^iπ+1 = 0

and Ugliness is represented by the 633 graphs representing the difference cases to check in the proof of the 4-color theorem (this is the "simplified" proof by Robertson, Sanders, Seymour and Thomas).