Nature · Study 026
Firefly Sync
170 fireflies start flashing at random and gradually fall into step, using only one rule: when a neighbour flashes, hurry up a little.
What you're looking at
Each firefly carries an internal clock that climbs steadily and fires a flash when it reaches the top. Seeing a nearby flash nudges its own clock forward by a small amount. That is the entire rule. Local clusters lock first, then clusters merge, and within a minute or so the meadow pulses as one.
The idea behind it
Certain fireflies in Southeast Asia and the Great Smoky Mountains really do this, in their thousands. The same pulse coupled mathematics, worked out by Mirollo and Strogatz in 1990, describes pacemaker cells in the heart settling on a shared beat.
Try this
Click or tap to scramble every clock and watch the swarm find its rhythm again.
