Knowtex

On March 31, 1851, Léon Foucault demonstrated for the first time in public that the Earth turns on its axis. His famous pendulum, installed for the occasion inside the Pantheon, in Paris, offered elegant proof of this imperceptible movement.

When a magnitude 6.8 earthquake shook Olympia, Wash., in 2001, shopowner Jason Ward discovered that a sand-tracing pendulum had recorded the vibrations in the image above.

Fifteen uncoupled simple pendulums of monotonically increasing lengths dance together to produce visual traveling waves, standing waves, beating, and (seemingly) random motion.

My father and I made the high-performance double pendulum. We're interested in the chaotic behavior!