Ultima Thule

In ancient times the northernmost region of the habitable world - hence, any distant, unknown or mysterious land.

Monday, May 08, 2006

Surprising relationship between chaos, order

By Aussiegirl

Hmm -- as usual, the universe presents us with perplexing conundrums -- order out of chaos, chaos out of order. On the one hand we have everything in the universe open to chance, on the other hand, things work quite predictably towards some sort of increasing order, while at the same time entropy drags everything down. In the midst of this we have life, which seems to have miraculously emerged out of a seemingly dead soup of minerals, and which, contrary to the laws of entropy, evolved into more and more highly complex forms. Just stew on that before dinner for a bit -- then try to create a little order out of that chaos in the fridge and make some dinner.

Surprising relationship between chaos, order

One of nature’s most baffling, perhaps deepest puzzles may seem quite removed from the grand questions scientists love to ponder—the fate of the universe, the nature of the invisible “dark energy” filling it, and the like.

The mystery has to do with a class of common events that can occur in full view, and share one key feature. In them, chaos inexplicably leads to greater regularity, or synchrony.

In certain experiments, “When you introduce disorder… the chaos that was present before disappears and there is order,” said Sebastian F. Brandt, a physics graduate student at Washington University in St. Louis.

Brandt and colleagues conducted a study that explored the conundrum, and which appeared in the January issue of the physics journal Physical Review Letters. The researchers said they found a surprising mechanism at work.

The researchers worked on a computer simulation of a network of pendulums. They chose pendulums as representative of a wider class of objects known as oscillators.

An oscillator is anything that somehow swings back and forth rhythmically when disturbed. Under the right conditions almost any sorts of objects, including atoms, can be oscillators.

The “pendulums” in the simulation were loosely connected to each other, as oscillators also are in many natural situations. A textbook example of such “coupled” oscillators is pendulums with springs linking their ends together. Other common cases are violin strings, which are connected by their sounding boards, and electrical filters used in communications.

The scientists found that the pendulums, when pushed by forces according to a regular rhythm, behaved chaotically and swung out of sync. Yet when the researchers introduced disorder—applying forces at random intervals to each oscillator—they began to swing in synch. The “forces” were applied along the rods of the “pendulums” to make them swing.

Physicists are as bewildered by all this as anyone else, said Ralf Wessel, a Washington University physicist who supervised the study: “Every physicist who hears this is surprised.”

Scientists have long been intrigued by the relationship between order and disorder, sometimes pointing to the emergence of life as an example of how order itself can arise from chaos.

Sometimes chaos can seemingly create its opposite. An example that might come to mind is that old favorite way of fixing a broken TV set—hitting it. Occasionally this solves the problem, but not always, Brandt said, showing that the principle only goes so far.


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