I took a video of a metal version of Bill Gosper's lissajoke rolling on the floor at Bob Hearn's house ( http://gosper.org/lissajoke.gif ). Completely coincidentally, Bob Hearn is narrating its ambiguous rolling behavior as I'm pushing it around on the floor. Anyway, here is the video https://www.youtube.com/watch?v=7YpYCgRt9Qc&list=UUbBGpH5hVMFF23WjuaFzjcw The ambiguous rolling effect is quite noticeable when I push it farther away. -- Thane Plambeck tplambeck@gmail.com http://counterwave.com/