Twelve pendulums: same mass, different lengths

Twelve balls are hung on strings of varied length. When the apparatus is given a swift tilt forward and backward, the balls swing back and forth in a sinusoidal fashion. After a minute, the motion becomes random. This demo was created by UC Berkeley students Andrew Halle and Genaro Hernandez.
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Everything to make this demo is stored in the back room of Pimentel. Come ready to do some repair work if you need to set it up. The pipe is just fitted by friction and it's been largely disassembled but likely some of the strings of the pendula have broken free.