More on science and technology from The Atlantic's archive.
More Flashbacks from The Atlantic's archive.
From Atlantic Unbound:
"Seeing Around Corners" (April 2002)
The new science of artificial societies can grow long-vanquished civilizations and modern-day genocides on computers—and perhaps help us to spot trouble ahead. By Jonathan Rauch
From Atlantic Unbound:
Interviews: "The World on a Screen" (March 29, 2002)
Jonathan Rauch, the author of "Seeing Around Corners," talks about what the study of artificial societies has to tell us about the real world.
Life, the Universe, and Everything
June 26, 2002
hroughout the ages, scientists and philosophers have searched for unifying theories of the universe. Ever since the publication of Isaac Newton's Principia in 1687, the standard approach has been to formulate laws of nature using mathematical equations and then to test these laws with experiments. But a new book by Stephen Wolfram—a respected physicist known for his contributions to complexity theory and technical computing—challenges that prevailing methodology. Indeed, A New Kind of Science, a work of epic proportions that grew out of Wolfram's computational experiments in the 1980s, is making headlines because of its call for a new language of scientific exploration based on computer programs.
In his book Wolfram argues that simple programming rules, when applied repeatedly, can provide a framework for the study of many disciplines—including physics, biology, mathematics, engineering, and economics. Wolfram's hypothesis is that the complexity of all physical systems, from cells to galaxies, can be explained by relatively simple rules, and that computers can be used to observe how those rules play out. To support this idea, he demonstrates how intricate patterns in nature, such as snowflakes, seashells, and fluid turbulence, can be generated by cellular automata—clusters of computerized nodes that evolve based on simple rules. The bigger picture, in Wolfram's view, is that these kinds of rules may unify our scientific knowledge. "I
have increasing evidence," he writes, "that thinking in terms of simple programs will make it possible to construct a single truly fundamental theory of physics, from which space, time, quantum mechanics and all the other known features of our universe will emerge."
Wolfram's ideas raise some interesting philosophical questions. Might the history of the universe be explained by a few lines of code rather than by conventional mathematics? What is the underlying structure of matter? And should scholars and scientists be directing more of their efforts toward uncovering general, cross-disciplinary theories, rather than narrow, specialized ones? These and related questions have been addressed by several Atlantic contributors over the past two decades.
The idea that computer algorithms can provide a framework for understanding physics is not new. In "Did the Universe Just Happen?" (April 1988), Robert Wright profiled Edward Fredkin, a self-taught computer scientist at MIT who went so far as to postulate that the universe actually is a computer. Drawing from his experience with information theory, Fredkin posited that computation is the basis of reality and that the structure of the universe is supported by a massive network of cellular automata. Wright explained the crux of Fredkin's argument as follows:
According to his theory of digital physics, information is more fundamental than matter and energy. He believes that atoms, electrons, and quarks consist ultimately of bits—binary units of information, like those that are the currency of computation in a personal computer or a pocket calculator. And he believes that the behavior of those bits, and thus of the entire universe, is governed by a single programming rule. This rule, Fredkin says, is something fairly simple, something vastly less arcane than the mathematical constructs that conventional physicists use to explain the dynamics of physical reality. Yet through ceaseless repetition
it has generated pervasive complexity.
Wright traced Fredkin's career through his years as a college dropout, a fighter pilot, a computer programmer, an inventor, and a professor, pointing out that Fredkin's unconventional training may have been what led to his ability to see things that other scientists could not. Fredkin was indeed a brilliant and intuitive thinker, one whose intellectual prowess was praised by world-renowned scientists like Richard Feynman and Marvin Minsky. But because there was no apparent way to test his theory empirically, Fredkin was forced to frame his ideas about the underlying structure of the universal digital rule, which he called "the prime mover of everything," in metaphysical terms. According to Fredkin, Wright explained,
[I]t doesn't matter what the information is made of, or what kind of computer produces it
. So long as the cellular automaton's rule is the same in each case, the patterns of information will be the same, and so will we, because the structure of our world depends on pattern, not on the pattern's substrate; a carbon atom, according to Fredkin, is a certain configuration of bits, not a certain kind of bits. Besides, we can never know what the information is made of or what kind of machine is processing it.
By contrast with the universe-as-computer theory that views the composition of matter as beside the point, unified theories in particle physics have sought to explain precisely what all matter is made of. In "The Gospel of String" (April 1986), Robert P. Crease and Charles C. Mann wrote about the evolution of string theory, which postulates that atoms are composed of tiny string-like particles. Crease and Mann began by placing the theory in the context of the history of physics. "Never before have so many physicists been persuaded that a Theory of Everything is nigh," they asserted.
Such a theory—a unification theory—would have to show that particles of mass (such as electrons) and particles of force (such as photons) somehow stem from the same thing. In the picture of matter provided by string theories, subatomic particles consist of minute rings as much smaller than an atom as an atom is smaller than the solar system. Each tiny loop can vibrate, undulate, and be besieged by little ripples that travel around its circumference.
The development of string theory, Crease and Mann wrote, was a collaborative effort that began in the late 1960s with the equations of the particle theorists Gabriele Veneziano, Yoichiro Nambu, and others. Their theory of the interactions among tiny strings withstood the challenge of alternative theories put forth by Sheldon Glashow, Howard Georgi, and others in the 1970s, and grew to become more integrative than previously was believed possible. Yet for all its elegance, string theory could not fully be tested experimentally. This condition largely persists in the field today, where scientists continue to advance the mathematics of the theory within the constraints imposed by relativity, quantum mechanics, and the limited amount of experimental data available.
The ideas of
string theorists are plagued by the difficulty that afflicts other unification theories as well: nobody yet has the faintest notion of how to test them. If strings exist, they can be seen only at energies so high and distances so small that experimental equipment may never be up to the task. Unable for the moment to count on direct verification of their ideas, string theorists are relying on the demands of mathematical consistency to guide their work. The calculational juggling act is so difficult
that many theorists think that only one theory can possibly do the trick. That survivor will be the Theory of Everything.
Difficult as it may be to attain a truly unified theory, there are those who believe strongly that the challenge must be met. In "Back From Chaos" (March 1998), the Harvard sociobiologist Edward O. Wilson championed the search for an underlying truth that he referred to as "consilience," a conceptual unification not only of scientific theory but of all forms of knowledge. "The greatest enterprise of the mind," he wrote, "always has been and always will be the attempt to link the sciences and the humanities." Wilson argued that the bridging of existing gaps—which he saw as "not reflections of the real world but artifacts of scholarship"—was inevitable based on the progress of science and art since the Enlightenment.
The belief in the possibility of consilience beyond science and across the great branches of learning is a metaphysical world view, and a minority one at that, shared by only a few scientists and philosophers. Consilience cannot be proven with logic from first principles or grounded in any definitive set of empirical tests, at least not any yet conceived. Its best support is no more than an extrapolation from the consistent past success of the natural sciences. Its surest test will be its effectiveness in the social sciences and the humanities. The strongest appeal of consilience is in the prospect of intellectual adventure and, if even only modest success is achieved, a better understanding of the human condition.
Despite what he perceived as a paucity of large-minded scholars today, Wilson was hopeful about the future of human understanding. For embedded in his review of the scientific and sociopolitical contributions of such intellectuals as the Marquis de Condorcet, René Descartes, Francis Bacon, and Isaac Newton was a deep faith in the righteousness of humanity's quest for a fundamental unity.
A balanced perspective cannot be acquired by studying disciplines in pieces; the consilience among them must be pursued. Such unification will be difficult to achieve. But I think it is inevitable.... To the extent that the gaps between the great branches of learning can be narrowed, diversity and depth of knowledge will increase. They will do so because of, not despite, the underlying cohesion achieved. The enterprise is important for yet another reason: It gives purpose to intellect. It promises that order, not chaos, lies beyond the horizon. Inevitably, I think, we will accept the adventure, go there, and find what we need to know.
Discuss this article in Post & Riposte.
More Flashbacks from The Atlantic's archive.
Greg Huang was recently a new media intern for The Atlantic.
All material copyright © 2002 by The Atlantic Monthly Group. All rights reserved.