A row of pendulums with carefully chosen lengths creates mesmerising patterns — all start together, then ripple and weave before reuniting. The beauty emerges purely from arithmetic: each pendulum has a period that is a ratio of the others.
Pendulum n has length Lₙ chosen so it completes n+1 swings in the time pendulum 1 completes 2 swings. As periods diverge, phase relationships produce apparent waves, spirals and braids. After one full period all N pendulums re-synchronise simultaneously.
Press Launch to release all pendulums from the same angle. Watch for the transient patterns at ¼, ½, ¾ of the full period. Adjust N (number of pendulums) and Amplitude. Hit Reset to restart from perfect alignment.
A viral 2010 Harvard Natural Sciences Demonstration video of a physical pendulum wave has over 60 million views. The same principle — closely spaced resonant frequencies beating against each other — explains the overtone shimmer of a piano string.