Has anyone seen this?
Basically it goes like this. A guy starts up five metronomes and they are not in sync.
He then places them on top of a board across two cans. Eventually they all sync up.
M M M M M
---------
O O
do the cans allow the platform to sway in such a way that they naturally sync up?
Am I being wooshed?
Didn’t he say the answer was obvious? Magic!
It looks like the supporting board begins to sway – if so, then it has to get energy from somewhere – the pendulums of the metronomes. Perhaps some lose more energy/momentum than others given the timing/position of their swing until things equalize. Just a thought for the science- or math- minded to shoot down or explain.
Yep, that’s exactly what’s happening. There is sufficient coupling through the platform to allow the metronomes to sync up. Pendulum clocks mounted to a wall will do the same thing. How tight the coupling is determines how quickly it happens.
It’s a well known effect. Goes back to at least Huygens.
Read Sync: How Order Emerges from Chaos in the Universe, Nature, and Daily Life by Steven H. Strogatz.
I remember reading (here I think) about an experiment with clocks fixed to a wall - apparently there is even enough energy transfer through such a seemingly rigid backing to permit them to sync.
You don’t say? 