Sync is the story of a dazzling kind of order in the universe, the harmony that comes from cycles in sync. The tendency to synchronize is one of the most far-reaching drives in all of nature. It extends from people to planets and from animals to atoms. Steve Strogatz looks at human sleep rhythms, menstrual synchrony, insect swarms, superconductors, lasers, heart rhythms and codes, showing how self-organization produces our coherent world.