How to synchronize metronomes

This video shows how you can synchronize a set of oscillators (e.g., metronomes, pendulum clocks, etc) by coupling them together. At the very end, you can see how this takes place, with one unsynchronized metronome changing its amplitude (its frequency is locked) to bring itself into sync with the others.

Video posted for use under Creative Commons Licence - by-nc-sa

Category:

Science & Technology

Tags:

• Physics
• UNSWTV

[watergleam]

What happens if each metronome were set to a different tempo?

[micolich]

@watergleam That's a good question, and the answer is that it depends on what you set them to. For example, suppose you set each so that it was one period longer than the next (i.e., one takes one second per tick, the next exactly two, the next three, the next four), then you could get some interesting quasi-periodic behaviour, where there's some longer repeating pattern. Set them at random, you probably get something very erratic.

Sounds like you've given me a suggestion for a sequel...

[thecaster]

Why do all of the demonstrations have five metronomes? Is this a special particular number?

[micolich]

@thecaster Good question. From a physics perspective, no. I think its that metronomes aren't cheap, and convincing your funds manager to buy 5 is easier than convincing them to buy 15 when 5 will do. 1 clearly isn't enough, 3 isn't impressive, 5 is enough for the job, so that's what everyone does. Would be cool to see a video with 500 of them. Anyone know someone who works in a metronome factory?

[eringobragh89]

@ micolich, I see that the oscillators in the center of the board seemed to come into synchronization quicker than the two on the border of the board. Is there a reason to that, or is that just the way it seemed to happen this time around?

[micolich]

@eringobragh89 Not sure. One could argue that the ones near the center are influenced from both sides (i.e., they have a metronome to both left and right) and the ones on the end aren't, but you'd need to do more experiments to confirm this.

[cryotwin]

I don't know why, but this make me smile. Just seeing things come together like that is always amazing, no mater how many times you see the experiment :)

[themarco84]

very cool.

[SuperTripps]

to me this is just another DEMO on how everything is vibration and resonant to such at its core

BRAVO

[TheMOSFET67]

@watergleam

Again, GREAT demonstration. What if there were 5 DIFFERENT metronomes set to 160 BPM? As metronomes are visual and audible representations of waves, although each metronome will still have the same frequency, the AMPLITUDE will differ from unit to unit, right? Will differing amplitudes preclude the metronomes syncing-up in this same experiment? My hunch is that both identical frequency AND AMPLITUDE are needed for the energy transfer necessary for syncing-up. Thanks!

[TheMOSFET67]

@eringobragh89

First, GREAT demonstration for illustrating MANY physics principles such as sympathetic vibration, sound wave dynamics, phasing principle, ect.

The explanation that the metronomes in the middle were influenced by others on both sides seemed reasonable. But upon further reflection, all things being equal, every metronome is sitting ON THE SAME piece of wood, and as the energy-sharing-medium is this wooden base, ALL metronomes would transfer and receive energy exactly equally.

[TheGreatSteve]

Dalek nuns with swords.

[juiceboxgasoline]

Really very awesome. :)

[DelphicExpanse]

just found your videos, they ar really interesting!