Entrainment and the Rhythm of Life:

"Everything moves in rhythm. Atomic particles, waves of electrons, molecules in wood and rocks, grass and trees, amoebas, mammals and birds, fishes and reptiles, the earth, the moon, the sun and stars...and we ourselves. All are dominated by rhythm.

"In us, as in all animals, the heart is most noticeably rhythm; but the blood pumped by our heart, along with the organs, muscles, and sinews nourished by our blood, also move in rhythm, whether we're conscious of it or not. Our breath, the most obvious manifestation of our inner condition, quickens or slows according to our state of mind or level of physical excitement.

"The world is thus alive with a myriad of rhythms. 'Entrainment' is the process by which these rhythms fall into synchronization with each other.

"Rhythmic entrainment is one of the great organizing principles of the world, as inescapable as gravity. It explains how one rhythm works with another, and how separate entities, from molecules to stars, will fall into rhythm as automatically as a pulse beats or a butterfly flaps its wings.

"If you set two out-of-sync pendulum clocks side by side, by the next day they'll be keeping time together. In fact, it looks as if they want to be locked into sync with each other. When you adjust the knobs on your radio, your adjusting the set's oscillators: when they come reasonably close to matching the frequency of a station's signal, they suddenly lock and pulse together, and your program jumps into focus.