Marcel Ausloos

A barometer on the island of Tahiti and a barometer in the Australian city of Darwin show different pressures. Subtract one from the other, and you get a number that climatologists call the Southern Oscillation Index. It changes every day, but within these daily jumps hide steady rhythms, just as the beats of a metronome hide within the noise of an orchestra.

The Paglia River behaves like a pendulum that resists being pushed. If a sudden influx of water pours in, the river does not keep gaining strength but quickly swings back to its usual level. This behavior is called antipersistence, and it was found in a twenty-two-year record of half-hourly discharge measurements near the Italian town of Orvieto.