Sunday, October 11, 2009

Steven Strogatz's Sync

Steven Strogatz's wonderful book Sync discusses how synchrony in biological networks is not only common, but neigh-inevitable. His opening discussion of fireflies is particularly vivid: along some riverbanks in Southeast Asia, populations of fireflies stretching for miles will all flash in synchrony, a phenomenon which baffled western explorers for decades. It turns out the effect is easy to replicate in a model-- say you have a collection of periodic oscillators which fire a burst of light at their peak and then reset, you can achieve synchrony if you make it so that each oscillator, when it fires, bumps its neighbors forward a bit in their cycles. Because firing induces a forced reset of the cycle, oscillators will be pushed forward in their cycles until they fall into sync, and then stay locked there; this effect takes off in small groups and quickly grows until the entire network is firing together.

The important points here being that a) neurons do this too (in fact it can be hard to get spiking neural networks to stop doing this) and it's really probably important to coding somehow, and b) you guys, fireflies are totally attempting to form some sort of massive insect-based consciousness here.

You can read more on the subject in the preview of the first chapter and a half, posted on Google Books.

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