Wonder of ScienceJul 10, 2023

Metronomes started randomly synchronize after a short period of time as they influence each other through the side-to-side motion of their shared base.

Source: UCLA Physics & Astronomy
https://demoweb.physics.ucla.edu/content/160-spontaneous-synchronization

160. Spontaneous Synchronization | UCLA Physics & Astronomy

Show threadWaterluvianJul 10, 2023
@wonderofscience What happens if half the metronomes are one frequency and half are another?
Show threadAT-AT Assault 🏳️‍⚧️Jul 11, 2023

@waterluvian @wonderofscience

No metronome shares the same frequency of another to begin with. Because perfect manufacturing tolerances don't exist, even 2 made for "the same frequency" are out of alignment.

Putting *any* metronomes on a shared base like this will cause them to eventually sync up.

Show threadWaterluvianJul 11, 2023
@atatassault @wonderofscience The metronomes need to be set to the same frequency for that to happen. If they’re set to the same frequency then their phase will tend to align.
Show threadJorge Stolfi

@waterluvian @atatassault @wonderofscience

In order for the phases to sync, the metronomes must temporarily swing at slightly different frequencies, even if they are tuned to the same frequency.

Thus, even if they are tuned to slightly different frequencies, they will eventually get in sync, at a common mean frequency, by the same physics.

Jul 11, 2023 at 2:06pmWeb
Show threadWaterluvianJul 11, 2023
@JorgeStolfi @atatassault @wonderofscience Ohh I’m seeing that in my head now. That a metronome set at 30bpm will eventually be made to tick at just under 100bpm if on a rolling table with 100 other metronomes at 100bpm.
Show threadJorge StolfiJul 11, 2023

@waterluvian @atatassault @wonderofscience

The key word is "slightly".

In your experiment, the 30 bpm metronome either will keep beating at ~30 bpm, but with slightly irregular period (the irregularities themselves roughly repeating at ~10 bpm); or it will eventually swing at 100 bpm too, but with a VERY small amplitude.