What happens when you set off 32 metronomes at different speeds and at different times? If you've been pondering such a question, we've got the answer for you. It's pretty amazing too, they sync and line up to the same rhythm. It has to do with the laws of physics, gravity in particular. After about a minute the forces of the swinging metronomes transmit and align, causing synchronous swinging by all metronomes—regardless of when each was set off and at what tempo.
A similar thing happens when two people are swinging on a swing set: eventually the two swinging people will get in sync due to the force of the heavier person transmitting through the frame, causing the lighter swinger to align. Just in case you were wondering. And here's the 32 metronomes obeying the laws of gravity... as demonstrated in a Japanese lab: