Daily Happy: Snakes, Squiggles, Spirals of the Pendulum Dance

The mesmerzing pendulum dance in motion

From NPR's Krulwich Wonders

What we have here is better, more cunning and a damn sight more beautiful than magic. It's a pendulum dance. A team at Harvard built this device. It's got 15 free-swinging pendulums, each a different length.

The longest one does 51 swings a minute. Its neighbor, a little shorter, does 52 swings...the next, 53, then 54 and so on...

The little guy down at the end does 65 swings a minute...

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. Read the full article