While putting away the bowls, I noticed some nice limaçons and cardioids made from the refraction of light. Video of the changing shape – Limaçons   For more info: http://mathworld.wolfram.com/Cardioid.html http://en.wikipedia.org/wiki/Cardioid http://en.wikipedia.org/wiki/Caustic_(optics) http://mathworld.wolfram.com/Limacon.html http://en.wikipedia.org/wiki/Limacon