Coupled Metronomes
Purpose
Five metronomes set to the same tempo start out of phase on a movable platform. Within about a minute, weak mechanical coupling through the platform causes them to synchronize spontaneously. Holding the platform still breaks synchronization; releasing it allows the metronomes to re-synchronize.
Figure 1:
Five metronomes on a foam board platform balanced on two soda cans inside a plastic tank. The cans allow the board to roll freely, providing the coupling mechanism.
Figure 2:
Top view showing pendulums aligned perpendicular to the rolling direction for maximum coupling.
Figure 3:
Metronomes running with pendulums at different phases before synchronization.
Figure 4:
Holding the board still decouples the metronomes, allowing them to drift out of phase.