Keay Davidson, San Francisco Chronicle, July 1, 2002
Once dismissed as a relic of the Middle Ages, the spirit of metaphysical speculation is alive and well—in computer science.
Over candlelight in cathedrals and monkish cells, medieval metaphysicians quarreled over ultimate mysteries of reality, such as: What is the nature of God? Are there other universes besides ours? And could God create other universes, if He wished?
Nowadays, with a daring that might have dazzled St. Augustine and St. Thomas Aquinas, two titans of the computer world argue that everything in the universe is a kind of computer.
Their sensational idea originally enjoyed a brief flurry of celebrity in the late 1980s, when one of the two, Ed Fredkin, proposed a particularly grandiose version of the idea. Now the idea is enjoying renewed publicity thanks to the publicity campaign run by the other man, Stephen Wolfram, to promote his book on the topic.
Wolfram’s A New Kind of Science is a five-pound, 1,200-page tome that has become a freak summer best-seller, rivaling John Grisham and Danielle Steel in sales. Thanks to an intensive publicity campaign, Wolfram is now the Britney Spears of science, whose self-published work has drawn a mostly gushing response from media, while some scientists are agog—or aghast.
“Spectacular, iconoclastic,” says one scientist. “More or less completely crazy . . . just nuts,” says another.
The excitement has also brought tension to the long-standing friendship between Wolfram and Fredkin, who are now wrestling with one of the bigger bummers of any scientist’s life: a dispute over originality. At stake is the question: Who hit on certain ideas first?
In reviews and interviews, Fredkin and a number of scientists and critics accused Wolfram—a 43-year-old computer tycoon who popularized the software program Mathematica—of unfairly claiming or implying that he invented many of the ideas in his book. Fredkin, 67, is the former head of MIT’s Laboratory for Computer Science and currently a visiting scientist at MIT’s Media Lab.
Ironically, reviewers—even Wolfram himself—have trouble summarizing what the book is about. It’s safe to say, though, that it’s about the use of insights from computer science to explain Everything: intelligence, mathematics, free will, determinism, the nature of space and time, and other Big Topics that fascinated our medieval ancestors, and that still enthrall the more philosophically inclined.
As of Thursday, the $44.95 book—which is jammed with very tiny print and images that resemble quilts designed by a seamstress on LSD—ranked 18th on Amazon.com’s list of 100 best sellers. It has intermittently hit No. 1, and has sold more than 120,000 copies since its publication in mid-May, Wolfram said in an interview.
The underlying theme of A New Kind of Science is that reality is like the “cellular automata” which scientists began simulating on computers three decades ago. These are computer programs—some of them extremely simple—that, if allowed to run indefinitely, may generate extraordinarily complex images and processes.
Gazing at these kaleidoscopically rich images, scholars such as Wolfram and Fredkin began to wonder if they were witnessing more than just pretty pictures.
Were they witnessing, in effect, the evolution of mini-universes on a computer screen?
They weren’t alone in speculating about a link between the computer images and the real world. Some scientists, such as Oxford University evolutionary theorist Richard Dawkins, claimed cellular automata mimicked the evolution of life. They developed cellular automata resembling insects that “crawled” around the screen and mutated, reproduced and ate each other.
Which was all a lot of fun—a higher-brow version of video gaming. But Fredkin and Wolfram went a step further: They wondered if our universe is, literally, a computer process of some kind, in which the ultimate reality is, say, space-time versions of the “bits” of data (represented by 0s and 1s) controlled by computer programs.
And if so, doesn’t that mean our concept of “reality” is some kind of cosmic illusion, as illusory as the “insects” on the computers? Perhaps even—hold on to your hats—a computer simulation run by some alien entity in another dimension? If so, as writer Robert Wright joked in a 1988 Atlantic Monthly cover story on Fredkin, “the good news is that our lives have purpose; the bad news is that their purpose is to help some remote hacker estimate pi to nine jillion decimal places.”
Wolfram refuses to go that far. In an interview with The Chronicle, he emphasized that unlike Fredkin, he’s simply trying to explain all reality in terms of cellular automata, as if the universe were a monstrous three-dimensional computer screen on which our lives and other phenomena pass in parade.
That parade is controlled by natural principles, not by some alien intelligence. He claims the process is revealed in objects as beautiful, yet mundane, as mollusk shells covered with grid-like patterns akin to those visible in cellular automata simulations on computer screens. If the complexity of mollusk shells can be explained in terms of cellular automata, then maybe the whole universe can—or so he seems to be saying.
Fredkin said that he’s open to the possibility that our reality is an illusion on some alien creature’s computer, in an alternate universe unseen by us. In his view, we are like passive observers of a nonstop TV show pumped into our minds, like a “virtual reality” simulation from which we can’t escape.
Needless to say, the scientific community has reacted emotionally to such bizarre claims.
Laughing, Fredkin recalls how his students informed him that a distinguished MIT physicist had told them: “Ed Fredkin is a computer person, so naturally he thinks the world is made up out of computer bits. If he were a cheese merchant, he’d be telling you the world is made out of cheese.”
In a book review to be published in the forthcoming issue of Physics Today, the University of Chicago physicist Leo Kadanoff calls the book “a tour de force of clarity and simplicity.” But “I cannot support the view that any ‘new kind of science’ is displayed (in the book). I see neither new kinds of calculations, nor new analytic theory, nor comparison with experiment.”
But the critics’ sorest point concerns questions of originality. “The problem is not just the rosy spotlight that Wolfram shines upon himself at center stage; it’s also the utter darkness that enshrouds all the other actors in this drama,” says Brian Hayes, a senior writer for American Scientist, writing in the July issue.
Fredkin says that about 20 years ago, at a scientific conference in the Caribbean, he proposed to Wolfram that the physics of the universe works the same as cellular automata. Wolfram “wouldn’t buy into it,” Fredkin says. During a subsequent encounter, “he described my ideas as crazy.”
Wolfram repeatedly insisted that he had given fair credit to Fredkin and other researchers who have developed cellular automata theory. “I tried to tell the history as best I could. It’s a very complicated story with all sorts of people,” Wolfram said in a phone interview.
Last week, the two men had a long, heartfelt phone conversation with each other, in which they tried to resolve their strong disagreement over priority. The conversation was amicable, but they failed to reach agreement.
Wolfram is “incompetent at giving people credit,” Fredkin said. “Even now he thinks he did a wonderful job of crediting everyone, but I don’t think he succeeded all that well.”
In retrospect, would Wolfram have changed the title of his book, A New Kind of Science?
“Absolutely not,” he declared. “I think it’s a very accurate representation of what I’ve done.” Even many of his scientific critics have praised the clarity and intellectual fascination of the book, and “I’m getting a lot of extremely positive feedback from nonscientists.”
In the long run, the priority dispute is small potatoes, Fredkin agrees. What counts is his and Wolfram’s mutual vision, wild though it may seem to others.
“There is nothing as ‘concrete’ in the world as a (computer) bit—it’s more concrete than a photon or electron,” Fredkin states. “It’s not a ‘simulation’ of reality; it’s not something that ‘pretends’ to be reality. It is reality.”