http://www.time.com/time/nation/arti...237033,00.html Sunday, May. 12, 2002
Cranks are an occupational hazard that every scientist eventually faces. Fortunately, these characters are usually easy to spot. If someone claims to have a grand theory that overturns centuries of scientific knowledge — especially when the theory spans unrelated fields like physics and biology and economics — the odds are good that he or she is a crank. If the author publishes not in a standard scientific journal but in a book for general readers, watch out. And if the book is issued by the author rather than a conventional publisher, the case is pretty much airtight.
Unless, that is, the author is Stephen Wolfram. Back in the 1980s, Wolfram was one of the hottest young scientists around. He got his Ph.D. in theoretical physics from Caltech in 1979 at the astonishing age of 20. A year later, he became the youngest person ever to receive a so-called genius grant from the MacArthur Foundation. He went on to write a scientific computing program called Mathematica that was so successful it made him a millionaire many times over. And then he dropped out of public view. What ever happened, people wondered, to Stephen Wolfram?
Now they know. This week Wolfram is publishing A New Kind of Science (Wolfram Media), a 1,200-page tome, some two decades in the making, that claims to redefine the foundations of virtually every branch of science, from physics and mathematics to biology and even psychology. "Stephen is not a modest man," says Terrence Sejnowski, director of the Computational Neurobiology Laboratory at the Salk Institute for Biological Studies in La Jolla, Calif., who is an avid Wolfram watcher. "But his ideas could turn out to be extremely important."
Those ideas had their genesis in the early 1980s, when Wolfram began to explore a type of computer program called a cellular automaton. It typically consists of a row of black and white pixels on a computer screen — the "cells"--and a simple rule for transforming that row into a new one. A rule might go like this: If a pixel in a given position is flanked by pixels of its opposite color, reverse its color when drawing the corresponding pixel in the next row; if not, keep it the same. By automatically applying the rule on each row as it moves down the screen (thus the term automaton), the computer builds up a pattern of remarkable complexity. Some of Wolfram's cellular automata made patterns that looked amazingly like those on seashells; others resembled snowflakes or leaves. "That got me wondering," he says. "Could it be that natural systems work in a similar way?"
He began exploring hundreds of different kinds of cellular automata and was astonished to find that the patterns emerging from his computer resembled all sorts of scientific phenomena — the subatomic trails emerging from a particle accelerator, the diagrams of curved space-time that arise from Einstein's equations, the spread of evolutionary changes in organisms through time, the graphic equivalent of different kinds of mathematical logic. "Under every conceptual rock I turned over," says Wolfram, "there's been this amazing wildlife I never expected to find."
Coupled with the fact that conventional equations can describe only the simplest natural phenomena (you can write an equation for the orbit of a single planet around the sun, for example, but not for an entire solar system, let alone a living cell), the success of his simple programs made Wolfram suspect that science has been heading in the wrong direction for the past 300 years or so. Instead of trying to write complicated equations for everything, he says, scientists should have been searching instead for the cellular automata that correspond to what they are observing.
It's a bold claim, even for someone as brilliant as Wolfram. And for now, nobody can really say whether it's right or wrong. The fact that some of Wolfram's patterns resemble things in nature suggests that the world may really work as his programs do. And the more precise the resemblance, the more seriously scientists take it.
But the final verdict on whether Wolfram's New Kind of Science is truly revolutionary — or whether cellular automata merely resemble rather than describe the world — will have to wait until scientists can digest it fully. And that could take a while. "Each idea in the book," says Sejnowski, "will take at least 10 years to explore and test." Provocative as Wolfram's theories are, he says, it's whether they agree with nature that will be the ultimate test.