New kind of science, old kind of sceptics?

十月 18, 2002

Stephen Wolfram had such confidence in his 'new intellectual structure' that he decided to sidestep peer review and publish A New Kind of Science himself. But while the book has proved a hit with the public, some fellow scientists are not so impressed. Stephen Phillips reports

The first hint that I might be in the presence of the avatar of a scientific revolution is that Stephen Wolfram is a couple of minutes late for our breakfast meeting. For the past decade, the 43-year-old physics prodigy-turned-software mogul has called it a day around now.

Wolfram turned his body clock upside down to give himself uninterrupted time through the small hours to pursue his hunch that simple rules - akin to the lines of code in computer software - may hold the key to divining the inner workings of the cosmos.

Working nocturnally, sequestered from the demands and interactions of normal life and running his software firm, Wolfram Research, remotely, he toiled relentlessly towards his goal of hammering out a new intellectual paradigm. Intelligence that the former wunderkind was holed up at work on some grand unspecified project stoked feverish anticipation in geek circles.

Earlier this year, Wolfram emerged from self-imposed exile brandishing a 1,200-page opus, A New Kind of Science , billed as the harbinger of a "new intellectual structure" and purporting to stand scientific orthodoxy on its head.

Scientists have been barking up the wrong tree, it proclaims. Mathematics, the traditional tool of scientific inquiry, cannot cope with the chaos encountered in the many phenomena that elude our understanding. Instead, Wolfram declares, the algorithms underpinning a software program offer a better way to penetrate life's darkest mysteries.

This bold assertion stems from the strange behaviour he observed in simple computer-generated geometric patterns, dubbed cellular automata. Confounding expectations, the application of the same rule governing the arrangement of black and white cells in successive rows sent them spiralling into myriad complex and random permutations.

Wolfram deconstructs the patterns observed in snowflakes, animal pigmentation and the veins of a leaf, contending that these complex phenomena are also spun out from the repetition of simple, consistent rules.

The theory holds manifold implications for a broad swath of disciplines, he maintains, from evolutionary biology, where it disproves natural selection, to philosophy, where it upholds free will at the expense of determinism.

Wolfram beguilingly concludes that the universe could boil down to the endless unspooling of a line of code that we might one day crack.

Provocative stuff. But Wolfram ratcheted up the heresy factor further by bypassing peer review, even the mediation of an external editor, and publishing his treatise himself, framed in jargon-free parlance for the general public.

Moreover, the book eschews self-effacing academic convention, taking the form of a headstrong first-person narrative - in the interests of getting its points across, according to the author.

Wolfram's heavyweight academic credentials demand that he be given a hearing. He was born in London, to a mother who was an Oxford University philosophy don, and he published his first research paper as a 15-year-old Eton schoolboy. He blazed a trail via Oxford University - where he didn't bother finishing his undergraduate degree - to the California Institute of Technology, where he earned a PhD in theoretical physics and was appointed a faculty member at the age of 20. The following year, he became the youngest recipient of a MacArthur "genius" fellowship.

He proceeded to Princeton's Institute for Advanced Study, Albert Einstein's alma mater, then the University of Illinois, before dropping out of academia, aged 28, to commercialise a software program he had developed. This program alone will ensure Wolfram's scientific legacy. Mathematica has become a staple of science faculty computer labs, automating a host of advanced calculations that previously had to be laboriously worked out on paper. It also made its creator a fortune, allowing him to set up as an independent scientist and to follow his interests wherever they took him.

Published in May, A New Kind of Science has been a commercial hit. Undaunted by its £40 price tag and intimidating bulk, consumers have snapped it up in droves, catapulting it into the bestseller ranks.

But it has won a decidedly frosty reception from academics. Far from hailing it as the progenitor of a new paradigm, many scientists have panned it as overblown, unoriginal, speculative and full of unacknowledged borrowings. The THES wanted to question Wolfram about this criticism as well as his decision to spurn academic convention.

In Chicago on the mid-western leg of a promotional tour of US universities, he is clearly enjoying the attention after ten years in solitary. The city is also home turf. Wolfram lives just down the road in Urbana-Champaign, seat of the University of Illinois and Wolfram Research.

The day before we speak, he lectured to a capacity crowd at the University of Chicago's movie theatre, a last-minute change of venue to accommodate the legions who lined up in advance to get their copy of A New Kind of Science signed and to pose with the author for a photograph. Even so, the crowd spilled into the aisles and middle-aged faculty members were forced to perch on stairs.

In person, Wolfram is genial but, like the cocksure narrator of his book, evinces no hint of self-doubt.

Unfazed, he says criticism goes with the territory. He has fortified himself with the Thomas Kuhn classic The Structure of Scientific Revolutions . Accordingly, he discounts academic scepticism as the typical resistance accompanying any revelation that upsets customary ways of thinking. With characteristic chutzpah, he notes that "it took 20 years before (Einstein's theory of relativity) was widely accepted", putting a similar gestation span on his own tenets gaining academic currency.

However, bracketing himself in such company is delusional, according to underwhelmed science faculty critics. The consensus is that the book fails to take account of the latest complexity research, appears to take credit for others' ideas and breaks scant new ground.

Wolfram says he has not "learnt a damn thing" from such belated peer review. "One person says that is interesting, another says it is not," he says. He feels the criticism vindicates his decision not to show his work-in-progress to others ahead of publication. It would have distracted him from the task at hand, he says. Many critics simply "haven't read the book".

By his own account, Wolfram didn't stint on his homework. His intellectual odyssey spanned 5,000 books and 11,000 papers, he says. In the book, he picturesquely recounts that he logged "more than 100 (computer) mouse miles". He kept abreast of the latest research in academic journals and even ran his ideas by specialists, he adds. It is just that he never showed his hand to anyone.

In fact, when his former researcher Matthew Cook broke ranks and presented an ingenious proof, pivotal to the book, that he had calculated for Wolfram at a 1998 conference, his ex-boss threatened to sue the host, the Santa Fe Institute, if it reproduced it in a journal of proceedings.

For some within academia, the dispute highlights a culture clash between the principles of open discourse and a proprietary approach to research.

Wolfram, however, contends this was not what was at issue. "The free, open exchange of ideas is one thing, but taking half-finished work and publishing it is another. You won't find any serious research group that would let a junior researcher tell what the senior researcher is doing."

But the case of Cook, now a Caltech research student, is also central to another controversy surrounding the book. His credit for proving rule 110, that a one-dimensional cellular automaton corresponds to a universal computer - which some consider to be the book's sole significant contribution to complexity research - is buried in small print at the back.

For his part, Wolfram says Cook required heavy supervision. But a chorus of reviewers have highlighted an overall pattern of Wolfram presenting others' work as his own and inflating his own importance.

This may be the fault of the book's strident, cocky tone. Wolfram refers to a trade-off between clarity and modesty in its pages, conceding that he sacrificed the latter to attain the former.

But despite its length, footnotes are markedly absent and attribution is relegated to perfunctory references in a 350-page notes section, leaving noses out of joint.

"He insinuates that he is largely responsible for basic ideas that have been central dogma in complex systems theory for 20 years," remarks Doyne Farmer, McKinsey professor at the Santa Fe Institute.

In the same vein, Seth Lloyd, mechanical engineering professor at the Massachusetts Institute of Technology, tells The THES : "Wolfram repeatedly insists that he was the first to discover that simple computational systems can give rise to arbitrarily complex behaviour. But only a legalistically narrow definition of the word 'simple' can make this statement true. Time and again he takes credit for results that closely resemble the works of others."

Wolfram counters that no one has been able to itemise specific instances of this. But injured parties cited in reviews include former MIT professor Edward Fredkin, who decades ago posited that computer algorithms offered a framework for understanding physics, and Norman Packard, who pioneered snowflake analysis.

Wolfram maintains he took painstaking surveys of several scientific fields, and he stands by their accuracy. Moreover, the book "also makes use of one important feature of modernity - that given a name and Google (the internet search engine) or an online bibliographic database" people can track down the provenance of findings referred to in the text.

Still, reading the book or listening to Wolfram's Chicago lecture, one could be forgiven for concluding that he single-handedly pioneered complexity research, which supposedly lapsed into abeyance when he left academia before being put back on track with the publication of A New Kind of Science . Reminding his audience that he is the chief executive of a private company, he also uses the lecture to eulogise about the capabilities of Mathematica.

Such hubris is his undoing, according to Caltech theoretical physicist Chris Adami, a computer-modelling specialist. Wolfram has cut himself off from his peers and the outcome is a book that overlooks fundamental details and is often "dead wrong", he says.

"The first guideline in science is (to) learn everything other people have done (then) if you think you have a new idea, try your hardest to demolish it. If you can't, grudgingly accede that it is new."

Wolfram hasn't applied such critical scrutiny to his own work, Adami says. "He is so convinced that his underlying view of the world is correct, he is building an edifice without worrying about the foundations."

But Wolfram says he's not trying to do things "in a traditional academic way". He explains that he distilled his ideas into a narrative because they cut across diverse subjects and multiple academic papers would have bogged readers down in the nitty-gritty too much and obscured the bigger picture.

But the devil is in the detail, and many observers say Wolfram fails to nail down the case for cellular automata illuminating a pervasive truth. The book offers scientists nothing concrete to work with and is, for practical purposes, useless, says Adami. "It makes strong claims but when it is time to back them up we have the catchphrase, 'I strongly suspect that is the case', instead of, 'Here is the proof.'" It is such a leap of faith that takes Wolfram from the interesting but limited patterns (of cellular automata) to "those of insects or humans or Chopin preludes", opines artificial-intelligence expert Ray Kurzweill in an online review of the book. But Wolfram counters: "I could say only things that I know are true and could have written a smaller book, but I believe that it's useful to tell people what I suspect. Part of what I've achieved is to develop a certain level of intuition."

Digging in for the long haul, he is confident that people will eventually cotton on to his vision. "It's got all the signs of a paradigm shift in the making - it's a scary thing to be in the middle of (but) I've seen some of this before with Mathematica," he observes, noting that after initial "turbulence" it was adopted incrementally.

But there is a disconcertingly self-referential tone to such thinking, ringing alarm bells that instead of being in the eye of a storm Wolfram may be in his own bubble. The exhortation to critics to "read the book" hints at the same closed feedback loop.

Examples of revolutionary insights that contemporaries failed to recognise abound. However, for every seismic new theory such as relativity that eventually gains credence, there is a crackpot one such as cold fusion that was roundly debunked.

"No scientist is an island," cautions Adami. "You are connected to a network of others. You have to have humility - the moment you abandon this you abandon the capability to contribute."

The one thing that is bulletproof is Wolfram's conviction that he has offered up a profound new truth. For now, we'll have to take his word for it.

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