Anti-parabola propoganda, plus musing on math class, cardioids, connect the dots, envelopes of lines, even a bit of origami.
Another way to get a cardioid is to add up circles like this: http://www.khanacademy.org/cs/sum-of-circles/1021299343
Extra points to a certain Andrea whose line-enveloped Hilbert curve inspired me to finish this video.
My personal website, which you might like: http://vihart.com
