This article by Natalie Wolchover originally appeared in Wired
WHEN THE INCOHERENT claps of a crowd suddenly become a pulse, as everyone starts clapping in unison, who decided? Not you; not anyone. Crickets sing in synchrony; metronomes placed side by side sway into lockstep; some fireflies blink together in the dark. … Indeed, we live because of synchronization. Neurons in our brains fire in synchronous patterns to operate our bodies and minds, and pacemaker cells in our hearts sync up to generate the beat. Objects with rhythms naturally synchronize.