Engines of Our Ingenuity

No. 657:
CHAOS AND ORDER

by John H. Lienhard

Click here for audio of Episode 657.

Today, a new look at a favorite cocktail party topic -- the Second Law of Thermodynamics. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

The world moves to greater and greater disorder. Everything deteriorates. Heat won't flow from cold bodies to hot ones. Sleds will never coast uphill. James Lovelock looked at the Second Law of Thermodynamics and said,
"... at first sight [it reads] like the notice at the gates of Dante's Hell."

But we shouldn't be too quick to abandon all hope. Our view of disorder is undergoing a stunning change. Until recently we saw only disorder rising out of probability. Things move from improbable order to inevitable disorder.

Enter now the computer. For years we could solve hardly anything but linear equations. That meant most of the problems we could take on were ones we could express as simple proportionalities. The computer let us solve much nastier problems.

Starting in the '60s, computer solutions began behaving the way linear solutions almost never had. A disarming number of these new non-linear solutions became chaotic when they marched forward in time.

Now here's the catch. There's no probability in the equations. They're deterministic. Yet, like the Second Law, they march us off toward chaos. Remember: These equations are analogs of nature. They do what nature itself does. March them forward in time and they lead to chaos as often as nature does.

Then the new computer solutions produced a second suprise. They didn't lead just to chaos. They also created a measure of order within chaos. Here's a pendulum slowed by friction. As we drive it, it swings in random lazy eights. It never repeats any swing exactly. Yet it's drawn back to the same general path in most of its swings.

The Second Law tells how systems behave only when they run down. But the Sun drives and replenishes our world. And these non-linear descriptions tell how nature behaves when it's driven.

The computer gives us a new way to look at nature. It tells us that chaos is far more a part of the natural order of things than we thought. But it also shows that nature finds large-scale order. The surface of Jupiter is rippled by the chaotic turbulent flow of gases. Yet the great red spot, a huge self-organizing vortex, sustains itself and feeds off that chaos.

In Moby Dick, Herman Melville observed, "There are some enterprises in which a careful disorderliness is the true method." It was canny remark indeed. For that careful disorder now proves to be the very method by which nature herself sustains grace, beauty -- and regeneration.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)


Gleick, J., CHAOS: Making a New Science. New York: Penguin Books, 1987.



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Copyright © 1988-1997 by John H. Lienhard. All Rights Reserved.
University Libraries, University of Houston, Houston, TX 77204-2091.


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