Physics of synchonizing metronomes

Factual Questions
1

How would you explain this phenomenon:

Five metronomes on a plank are started at random speeds, then the plank with the metronomes is placed on top of two pop cans so it can wiggle back and forth. After about 30 seconds, the metronomes synchronize.

It has been awhile since I’ve taken a mechanics course, but it seems to me to be some kind of resonance effect. Can this system be modeled as a coupled or driven harmonic oscillator, or something of that ilk?

2

Done, less than a week ago: http://boards.straightdope.com/sdmb/showthread.php?t=465973&highlight=metronome

3

Oi. My bad. Mods feel free to close.

4

To the OP … they are NOT started at random speeds. They are all started at exactly the same speed, but at random phase relative to each other. BIG difference.

5

Closed at OP’s request.

Gfactor
General Questions Moderator