Complex Questions

The new science of sponstaneous order

William Tucker from the January 1996 issue

(Page 2 of 4)

Charles Bennett of IBM has defined this amount of thinking a computing machine has to do to generate a printout as "depth." Neither a perfectly ordered system ("Print 1 followed by a trillion zeros") or a perfectly disordered one ("Print 1823749567819074823719...") has much depth to it. Instead, depthwhich is essentially a measure of complexityoccurs in the middle range. This middle area has been defined as a "phase transition" between order and chaos.

Systems become "deeper" and more complex as elements of time and memory are added. A perfectly elastic ball bouncing on a table has no memory and can be described almost perfectly by the linear equations of physics. A hurricane gathering force, on the other hand, is nonlinear and virtually impossible to describe in mathematical terms. Rather than complex, it is "chaotic."

Although chaotic systems are inherently unpredictable, they can be described by certain laws, the most important being the "butterfly effect," which says that small changes in initial conditions can produce enormous changes in outcome. (The term comes from the piquant obser vation that, since weather patterns are chaotic, a butterfly flapping its wings in Mexico today can change the weather in Chicago next month.)

Chemical reactions are complex without necessarily being chaotic. Take a container filled with hydrogen and oxygen atoms in a 2-to-1 ratio and certain predictions can be made. Still, it will make an enormous difference whether the atoms are already bonded to form water mol ecules or whether they are ionized and volatile. The system has memory and therefore requires more information to describe it.

Biology is more complex again. Biological systems all obey the laws of physics and chem istry, yet still have qualities that cannot be derived from physics and chemistry. To understand Preston's curve, for example, you have to know something about the actions of biological organ isms within evolutionary time.

In his book The Quark and the Jaguar, physicist Murray Gell-Mann, who won the Nobel Prize for his quark theory, posits that complexity explains why all the action of the universe cannot simply be reduced to a few fundamental rules. Or, to put it differently, complexity theory says that, given a complete knowledge of the state of the universe at its inception and given a complete knowledge of the laws of physics and chemistry, it would still be impossible to predict the path of life on Earth.

"I know of no serious scientist who believes that there are special chemical forces that do not arise from underlying physical forces," writes Gell-Mann. "In that sense, we are all reduc tionists. But the very fact that chemistry is more special than elementary particle physics, apply ing only under the particular conditions that allow chemical phenomena to occur, means that information about those special conditions must be fed into the equations."

The differential applies even more strongly to biology. "To begin with, many features common to all life on Earth may be the result of accidents that occurred early in the history of life on the planet but could have turned out differently," writes Gell-Mann. In that case, terres trial life has taken on a good deal of effective complexity, since a great deal of new information would have to be plugged into the equations to describe its outcome.

Even if terrestrial biology is not unique, it still contains a good deal of depth. "The science of biology is very much more complex than fundamental physics because so many of the regu larities of terrestrial biology arise from chance events as well as fundamental laws," writes Gell-Mann. Economics, psychology, and human cultures have even greater depth and complexity than biology, simply because they are based on human beings' biological nature but also go beyond it.

Gell-Mann says he formulated this hierarchy partly in response to the reductionism he found among his colleagues at Caltech. Many specialists argued that the human mind had no unique qualities that could not be described by the workings of electrical impulses and organic chemistry. "Some refused to talk about the mind at all," he recalls. "One friend of mine called it 'the M-word.'"

Now the anti-reductionists are on the counterattack. Says Kauffman: "The past three centu ries of science have been predominantly reductionist, attempting to break complex systems into simple parts, and those parts, in turn, into simpler parts. This program has been spectacularly successful, but it has also left a vacuum. How do we use the information gleaned about the parts to build a theory of the whole? The complex whole, in a completely non-mystical way, can often exhibit collective properties'emergent' featuresthat are lawful and unique in their own right. These properties constitute the 'self-organization' or 'spontaneous order' of the system."

Kauffman posits that the spontaneous order being discovered in natural systems makes the genesis of life seem natural, even expected. Rather than the blind, one-shot miracle implied by Darwin's theory of natural selection, life on Earth may be the orderly and expected outcome of nature's inherent tendencies toward self-organization. "Natural selection is important, but it has not labored alone to create the fine architectures of the biosphere," says Kauffman. "I believe the order of the biological world's not merely tinkered, but arises naturally and spontaneously because of laws of complexity that we are just beginning to understand."

In the recently published At Home in the Universe , a popular account of his ideas, Kauffman is even more enthusiastic: "Profound order is being discovered in large, complex, and apparently random systems. I believe that this emergent order underlies not only the origin of life itself, but much of the order seen in organisms today....If all this is true, what a revision of the Darwinian worldview will lie before us! Not we the accidental, but we the expected!"

Nor does Kauffman shrink from the obvious implications of this discovery:

"Most important of all, if this is true, life is vastly more probable than we have supposed.