« Tort v. Terror | Home | Wit & Wisdom »
June 20, 2002
The NEW secret of the universe
A brilliant computer scientist named Stephen Wolfram has just emerged from 10 years of reclusion to make the bold claim that he has discovered "A New Kind of Science" in a book by that name. I haven't read the book yet, but have read this review in The Economist. The crux of the argument seems to be that the world is best described by computational models, rather than the mathematical formulas that we grew up learning about in physics class. While there may be something in this, The Economist contends that Wolfram's weakness is his insistence that this new model explains and applies to absolutely everything. Wolfram's argument is appealing at a certain level because it would explain how the complexity of the universe can be explained through simple rules--and not unknowable intelligent design.
But I wonder why Wolfram's rule-based view of the universe is incompatible with the equation based view. Many equations (such as that for gravity) explain behavior, but not necessarily the mechanics of that behavior (we are not quote sure how gravity works, but we know how it behaves.) Is it possible both approaches are simply two ways of analyzing the same phenomena? I guess I'll have to read the book. If you've read it, please comment on it. Anyone want to champion this for the book club? if so, I'll do my best to get Wolfram out here to speak to us.
Excerpts from The Economist's review:
At its heart is the notion of modelling physical phenomena in terms of simple computer programs, rather than complicated mathematical equations. Mr Wolfram unashamedly compares the potential impact of his work to that of Sir Isaac Newton's “Principia Mathematica”, and suggests that his discoveries can answer long-standing puzzles in mathematics, physics, biology and philosophy, from the fundamental laws of nature to the question of free will....
Yet publication has been anticipated in some quarters for years, and that message—that the universe is best understood through computing, rather than traditional mathematics—has struck a chord with the Internet crowd. ...This was Mr Wolfram's Eureka moment: it suggested to him that complex systems in nature—be they weather systems, turbid fluid flow, a zebra's stripes or the human mind—might all be governed by small and simple sets of rules. ...
Mr Wolfram shows with countless examples how apparently simple systems can give rise to extraordinarily complex behaviour.
Having settled that beyond question, he then makes a vast speculative leap. Because complex behaviour is abundant in nature and because it can be produced by simple systems akin to cellular automata, that, he asserts, is how all complex behaviour must be produced. Et voilà, he has found the secret of the universe: simple computation rules can yield structures that resemble trees, shells and snowflakes; that, Mr Wolfram tells us, is therefore how nature generates everything.
Mere equations, he observes, cannot capture such complexity, whereas simple computational rules can. ...
That said, one of the most impressive parts of the book is Mr Wolfram's guess that the universe might, in fact, be a giant cellular automaton at the subatomic level. His elaborate model cleverly accounts for physical phenomena such as causality, relativity, and the finite speed of light. Similarly, his demonstration that a cellular automaton known as Rule 110 can operate as a universal computer—the simplest possible computer, but one that can be usedto simulate an arbitrarily complexmachine—is a tour de force.
Yet these triumphs are undermined by Mr Wolfram's insistence on trying to use his computational approach to explain absolutely everything. Scientists in many fields, from quantum physics to cosmology, like to think that the secret of the universe lies in their particular fief. Recent books have suggested that multiple universes or quantum gravity can explain consciousness or free will. This kind of speculation is usually kept for the final chapter. Mr Wolfram's entire book is shot through with it. He sees the history of science as a prelude to his years at the keyboard, and the computer as powerful an instrument of discovery as the telescope or microscope. He also seems to want to take credit for complexity theory itself.
There's no short cut
One last act of daring is Mr Wolfram's principle of computational equivalence, by which he lumps together all complex phenomena as equally complex manifestations of the same underlying rules for cellular automata. All unpredictable processes, he argues, from water going down a plughole to human consciousness, are computationally equivalent. He notes that great scientific breakthroughs in the past have undermined humanity's belief that it is special. But that does not mean that every such theory is correct. ...
Leave a comment