Pendulum DancePosted: May 19, 2011
I first saw this on YouTube a few days ago, but didn’t realize until today that it was part of an NPR.org story by Robert Krulwich.
A team at Harvard built this device. It’s got 15 free-swinging pendulums, each a different length. […]
Once they’re set swinging, the balls form a line, then quickly fall out of sync and, as you watch, patterns emerge out of nowhere, snakes, squiggles, spirals. At the exact midpoint (57 seconds in on the video), half the pendulums are at one “amplitude maximum,” the other half at the other “amplitude maximum,” like ladies and gentlemen at a palace ball. You can almost see them curtsying and bowing.
But here’s the sly part.
There are secret choreographers in the house: Time and Motion. The Harvard design team has built the device so the pattern repeats every 60 seconds. Precisely. This dance, like Cinderella’s ball, has a fixed end point.