Some famous scientists, when you meet them, seem smaller than their reputations, others larger. Phil Anderson was the latter kind. Anderson, who died on March 29 at the age of 96, was an acerbic giant of 20th-century physics, who defied the ultra-reductionism of particle physics and helped inspire the fields of chaos and complexity. I first interviewed Anderson by phone in 1986 after the discovery of high-temperature superconductors, and he became impatient with my ignorance. In a 1996 review of my book The End of Science, he accused me of contributing to “a wave of antiscientism.” In a 1999 column in Physics Today, he chided me for pessimism and coined the term “Horganism” to describe "the belief that the end of science (or at least of our science) is at hand." I feel privileged to have met Anderson and to have been the target of his criticism. “Horganism” is now my Twitter handle. Below is a profile of Anderson that I wrote for Scientific American after I spent a day with him at Princeton in 1994. I especially like the last line.– John Horgan
Philip W. Anderson speaks in a slow, deliberate growl, pausing between sentences to ponder his next move. His basal expression, too, is deadpan. But like some exotic ceramic in an unstable state, Anderson's mood can flip in an instant between different modes.
Discussing a conference he just attended, the Nobel laureate and professor of physics at Princeton University recalls a session on cancer with obvious delight. The talks left him marveling at the "layers upon layers upon layers" of error-correction mechanisms that enable genes to replicate with scarcely a mistake. Researchers, he exults, will have to discover profound new principles to account for this phenomenon.
On the other hand, a session on his own specialty, high-temperature superconductors, was "horrible." Anderson accuses researchers of "looking under the streetlight" instead of venturing away from known territory for solutions to their problems.
Anderson talks bitterly about his relationship to the rest of solid-state physics. "Sometimes I feel like a large, slow target," he says. "To say something a little cynical, sometimes I think the aspiring young man dreams of showing up the prestigious old character. It certainly would do his reputation no good simply to show that I was right."
An authority on superconductivity, superfluidity and other quantum antics of condensed matter, Anderson has been what one colleague calls a "commanding presence" in physics for more than 40 years. He began challenging the ultra-reductionism of particle physics before that became fashionable. His 1972 article "More Is Different" became a rallying cry for anti-reductionist fields like chaos and complexity studies.
Readers of Anderson's essays in Physics Today and elsewhere--many of which were published in his book A Career in Theoretical Physics--know he can be a gruff guru. One month he writes with lyric fervor on how the interplay of order and disorder found in condensed-matter systems can serve as a metaphor for life itself."
The next he complains that young scientists "don't seem to realize that the possession of a Ph.D. never guaranteed a career in basic research: it is and should be the privilege of a small elite."
Robert Schrieffer, a Nobel laureate in physics who has often butted heads with Anderson, admires his blunt style. Anderson "has played a uniquely provocative role to make sure that people get things right," Schrieffer says. But he adds that Anderson can be undiplomatic.
Anderson does not apologize for being blunt. "I just call 'em as I see 'em," he says. It bothers him, however, that some colleagues see him as "dogmatic and authoritarian." He considers himself "a rebel."
Anderson's contrarianism emerged when he was a student at Harvard after World War II. Graduate students in physics were flocking to the lectures of Julian Schwinger, who later won a Nobel prize for explaining how quantum mechanics could account for electromagnetism. "There was this tremendous excitement and gang of people around Schwinger, and I wanted to go in the other direction," Anderson says.
Anderson felt drawn to questions of more practical relevance. After he got his doctorate in 1949, Anderson went to Bell Laboratories, where he worked with John Bardeen and William Shockley, inventors of the transistor, and Charles Townes, who created the maser. "It was a highly competitive group," Anderson says.
At Bell Labs, Anderson sought to show how phenomena such as superconductivity emerged from intricate alliances and conflicts between electrons and other quantum entities. In the mid-1950's, he proposed a radical explanation for why impurities in semiconductors sometimes switched from being conductors to insulators. His work on this effect, called localization, earned him the Nobel prize in 1977 along with John H. Van Vleck and Neville Mott.
In the early 1960's, Anderson temporarily left Bell Labs to take a position at the University of Cambridge. Teaching condensed-matter physics represents a special challenge, he says, one that is generally not well met. Some practitioners have poor ideas about what constitutes an important problem or even what constitutes evidence. "Also, very few people have a unified view of the subject."
As a result, most courses on condensed-matter physics make it sound "almost as bad as chemistry: just phenomenon after phenomenon after phenomenon." Anderson has sought to explain the details of his field with a concept called broken symmetry. For example, a liquid crystal, which consists of molecules that act like minute magnets, is at its most symmetrical when the molecules are randomly aligned. That symmetry is "broken" and replaced by a new, more restrictive symmetry when a current is applied to the crystal, forcing the molecules to line up in the same direction.
Anderson’s pedagogical style must have worked. His lectures at Cambridge inspired a shy young student named Brian Josephson to discover a peculiar property of certain superconducting circuits. Josephson received the Nobel prize for his discovery, now known as the Josephson effect.
Anderson's work on symmetry-breaking in superconductivity also provoked Peter Higgs to suggest how a similar mechanism might have caused particles to acquire their masses when the universe was still young and hot. The Higgs boson, which supposedly precipitates the symmetry breaking, became the most sought-after prize of particle physics. The ill-fated Superconducting Supercollider was intended to find it.
Anderson's relationship with particle physicists was contentious. In the 1960's, he complains, they "were claiming on all sides that they were doing the fundamental science, and what the rest of us were doing was just engineering."
Anderson challenged this assertion in his 1972 "More Is Different" article, pointing out that reality has a hierarchical structure, with each level independent, to some degree, of the levels above and below. "At each stage, entirely new laws, concepts and generalizations are necessary, requiring inspiration and creativity to just as great a degree as in the previous one," Anderson argued. "Psychology is not applied biology, nor is biology applied chemistry."
Anderson also proposed that symmetry-breaking played a role in the emergence of life, consciousness and other complex phenomena. He began getting invited to unconventional meetings, including one in the late 1970's on emergent systems. Speakers included an authority on psychedelic drugs and a Marxist who espoused a physical theory of social evolution. "I won't call them weirdos, because I was one of them," Anderson says.
In the late 1980's, Anderson criticized the Superconducting Supercollider at Congressional hearings, contending that the machine would not address issues of uniquely theoretical significance or practical value.
"I confined myself to saying things that were manifestly true," he recalls. Asked if Congress's decision to kill the accelerator left him with any regrets, Anderson says he is only "sorry that Congress let them go on so long."
Anderson rejects the contention of some particle physicists that the SSC's death heralds a growing anti-science movement in the U.S. "There have been yahoos in every period in American history. I don't think there is an effective anti-science movement." He is frightened by the religious right, but for political reasons. "If they get into power, we'll have to defend a hell of a lot besides science."
Anderson has a tense relationship with particle physicist Murray Gell-Mann, who calls Anderson’s field "squalid-state physics." Gell-Mann has suggested that Anderson might have supported the SSC if the Higgs boson were called the Anderson-Higgs boson. Anderson retorts that Gell-Mann, in his book The Quark and the Jaguar, offers a "very unsatisfying" explanation of how simple laws of physics could generate so much complexity. Gell-Mann, Anderson suggests, "has been away from real nuts and bolts of physics too long."
Anderson and Gell-Mann have both lent their prestige to the decade-old Santa Fe Institute, a center of complexity studies. Anderson worries that some complexity researchers have too much faith in computer simulations. "Since I know a little bit about global economic models, I know that they don't work." He adds, "I always wonder whether global climate models and oceanic circulation models... are as full of phony statistics and measurements" as economic models.
Anderson, 70, is still teaching at Princeton, whose faculty he joined in 1975. He has created an interdisciplinary course on "origins and beginnings," which covers big questions in cosmology and biology. Anderson suspects that some questions may resist final answers. He is particularly skeptical of the claims of some scientists that science can achieve a "theory of everything."
Anderson has seen many wildly ambitious theories, like cybernetics and catastrophe theory, come and go. To be sure, certain scientific principles have broad applicability, such as evolution in biology and symmetry-breaking in physics. "But you mustn't give in to the temptation to believe that a principle that works at one level will work at all levels," Anderson declares. "You never understand everything. When one understands everything, one has gone crazy."
See also my free, online book Mind-Body Problems: Science, Subjectivity & Who We Really Are.