Modular arithmetic is probably one of the coolest subjects we covered in high school, but we didn't spend enough time on it. I actually learned all about it fro

Modular arithmetic is probably one of the coolest subjects we covered in high school, but we didn't spend enough time on it. I actually learned all about it from reading Simon Singh's The Code Book in sixth grade--it's a great introduction to cryptography and covers the basics of modular arithmetic to introduce RSA. Towards the end of high school, I decided to play around with graphing equations as colors. I came up with a bunch of cool patterns including pretty much all of the ones in the article--the easiest way to make a function well-behaved across a color channel is to make it mod 255. Playing around with different functions this way is really fun; I suggest everybody try it. If you want to draw pictures like this but don't want to write your own program for this, you can use mine: http://inst.eecs.berkeley.edu/~tikhon/draw http://inst.eecs.berkeley.edu/~tikhon/draw.