Stephen Strogatz is a mathematician who has studied synchrony in nature. Synchrony is the “spontaneous tendency of separate entities to act as a unit.” Strogatz finds synchrony “everywhere” in nature. He stresses that you don’t need to be smart to synchronize, nor do you need to have a brain or even be alive. I learned all of this by watching Strogatz giving a 20-minute talk on TED.  Strogatz plays some compelling bird and fish video during his talk.

Strogatz offers a several general principles regarding synchrony.  Sync is arguably the most pervasive drive in all of nature. Sync is the “deep tendency toward order in nature that opposes all we’ve been taught about entropy. Strogatz stresses that the law of entropy “is not wrong,” but there is a countervailing force in the universe: the tendency toward spontaneous order.

[Note: I previously wrote a somewhat detailed post regarding spontaneous order here, illustrated by the self-organized hexagonal pattern at Saturn’s north pole.]

The most impressive thing about synchrony in nature is that no choreographer is needed. Things “choreographer themselves.” He uses the examples of flocking birds and schooling fishes. No one is in charge in either case.  Flocking and schooling make it considerably less likely that you will end up being eaten by a predator. According to computer simulations that have been run in an attempt to understand this dramatic phenomenon, it looks like only four simple and local rules account for all of the emergent synchronous behavior of flocks and schools.

Strogatz offers some comments that run deep.  Although it looks as if each individual fish or bird is acting to cooperate, what’s really going on is a kind of selfish behavior. Each animal “is scattering away at random to save its scales or feathers. Out of the desire to save itself, each creature is following these rules and that leads to something that is safe for all of them, even though it looks like there thinking as a group. They’re not.”  Strogatz points out the impressive “waves” that one can see in a flock (or a school). One especially notable characteristic is the rapid transmission of waves through the flock (or school).

Strogatz gives examples (and video) regarding fireflies of Thailand and Borneo (although not the fireflies of North America, which do not synchronize their flashing). He points out that the pacemaker for the human heart is a “democracy of 10,000 cells” that work together, somehow. Even nonliving things synchronize. They “communicate” through mechanical means. One example is a laser. Strogatz also runs a simple demonstration with two metronomes (but here is a much more impressive demonstration).  Although this experiment was delightful to watch, it wasn’t surprising to me, as I’d previously read of the spontaneous synchronization of two independent clock pendulums when they hang from the same wall.

The prejudice of many people is that order can only occur with someone “in charge,” not spontaneously. Although Strogatz’ talk didn’t touch on this particular topic, it seems to be the common belief that order doesn’t come easily (and certainly not for free) that underlies the belief of many people that there must be Grand Orchestra Leader keeping things running in synchrony down here on earth.  Apparently not so.  The things down here on earth are quite proficient at “talking” with one another and syncing up.

If you want to know more, invest a measly 20-minutes in Strogatz’ fast-paced lecture on synchrony. If you decide to watch this lecture with other people, make sure you clap in synchrony at the end of the show.