Spontaneous Synchronization in Metronomes (3A70.23)

Description:

Five small metronomes on a lightweight board are set to the same frequency and started oscillating out of phase. At first the board sits on the table and the metronomes will oscillate independently. The board is then placed on two empty aluminum cans (on their sides) to provide some light coupling between the metronomes. The metronomes will phase lock with each other within a minute or two and their 'tick-tocks' will all be in unison.

Procedure or Operation Notes:

Set the metronomes to the same frequency in the range of 160 to 180 bpm. Place the metronomes on the balsa wood plank and set that on two sturdy blocks.

Then carefully move the balsa wood plank to the two empty aluminum cans that sit on the glass plate. The metronomes will synchronize quickly due to the light coupling through the plank and the low rolling resistance of the cans on the glass plate.

References, Comments, or Footnotes:

1) James Pantaleone, "Synchronization of metronomes." American Journal of Physics 70:10, 992-1000.

2) Steven Strogatz and Ian Stewart, "Coupled Oscillators and Biological Synchronization." Scientific American 269(6), 102-109.

3) The metronomes are Wittner Taktell Super-Mini.