Physics or Wizardry? 32 Metronomes Tell the Tale
Like one hand clapping, a single metronome is always in sync with itself. But add another and you’d have to try pretty hard to get them to both click perfectly in sync. How about thirty-two of them?
Impossible. Right?
Actually it’s quite possible, as this video proves. Exactly 32 metronomes unite in synchronous play with no help from human hands. And there’s simple physics at the heart of it.
When the arm of any metronome hits the side, it exerts a force on the blue platform. Normally friction would make that unnoticeable. But this platform is special. It’s set up on rollers so that it can move from side to side.
When any two metronome arms hit, their forces on the platform either cancel out or add together, depending on how out of or in sync they are. Any arms that are out of sync will experience a force in the opposite direction that inches them closer to the pack.
Eventually all 32 arms find the same rhythm and sync up. This is the most I’ve ever seen at once. (That’s a challenge, by the way. Get on it.)
(video by IkeguchiLab)
Watch for the last one to get in line (the pink one second from the front in the row on the right). For a while it’s in sync, but moving exactly opposite from all the others. And then you can see it swing wildly as it finally gets in line. So cool.
This is actually similar to some work I do with lasers, just with mechanical oscillations instead of optical ones. It’s so cool!
You want to listen to this. The audio here is excellent in terms of demonstrating emergent behaviour.
