by Lee Smolin
To get a bearing on the meaning of time in general relativity, Barbour read deeply into the subject, working his way back through the history of physics and philosophy. He finally was able to invent a new kind of theory, in which space and time are nothing but a system of relationships. His papers on this subject slowly began to be noticed, and eventually he became an honored member of the quantum-gravity community. His reinterpretation of Einstein’s general theory of relativity as a relational theory is now the way we in the field understand it.
This is not nearly all that Barbour has done, but it’s enough to show how the career of a successful seer differs from that of a conventional academic scientist. Such a person does not follow fashion—in fact, probably does not even follow a field well enough to know what the fashion is. People like this are driven by nothing except a conviction, gained early, that everyone else is missing something crucial. Their approach is more scholarly, in that to think clearly they have to read through the whole history of the question that obsesses them. Their work is intensely focused, yet it takes them a long time to get somewhere. In furtherance of an academic career there is no output whatsoever. Julian Barbour, when he was ready, changed science more than most academic scientists have, but at an age when most academic physicists are up for tenure, he had absolutely nothing to show for his work.
Barbour’s career resembles that of other seers, like Charles Darwin, who also retreated to the English countryside to find the room to think through an idea that obsessed him. Einstein spent ten years thinking about the ideas that became special relativity, and then spent the next ten inventing general relativity. Time and the freedom to think, then, are all that a seer needs to find that unexamined assumption. The rest they do themselves.
Another such person is David Finkelstein, professor emeritus of the Georgia Institute of Technology, who has spent his whole life looking for the logic of nature. He does physics differently from anyone else. His life’s work has been a quest to understand, as he put it when we first met, “how God might have thought the world into existence.” He never did anything but this, and each time we meet he has a new insight about it. Along the way, there have been a few spin-offs. He was the first person to understand what the event horizon of a black hole is.12 He was the first to discover important features of solid-state physics called topological conservation laws, and he was also the first to study a variety of mathematical structures—quantum groups, for example. His life serves as a lesson for the range of contributions a seer can make while on his own road to truth. Whereas Finkelstein did have an academic career, could someone like him—someone who listens only to an inner voice and ignores almost everything else—get a professorship these days at a major university? Dream on.
Here is another story, this one more like Barbour’s. Antony Valentini started with an undergraduate degree from Cambridge, as did Barbour. Then he wandered Europe for a few years, eventually settling in Trieste to study with Dennis Sciama, who at Cambridge had been the teacher of Stephen Hawking, Roger Penrose, Martin Rees, George Ellis, and several other great relativists and cosmologists. Late in his career, Sciama had moved to Trieste and founded an astrophysics group at a new Italian institute called SISSA (for Scuola Internationale Superiore di Studi Avanzati). Valentini was one of the last of Sciama’s students, and he didn’t work on astrophysics; instead, he pursued work in quantum theory, based on a gut feeling that it made no sense. He studied an old idea, first developed by Louis de Broglie in the 1920s, called a hidden-variables theory, according to which there is a single reality hidden behind the equations of quantum theory. The idea of hidden variables was suppressed for decades—despite support by Einstein, Schrödinger, and others—partly because of a false proof published by John von Neumann in 1932 that such theories could not exist. The mistake was finally uncovered by the quantum theorist David Bohm in the early 1950s, who then revived de Broglie’s theory. Valentini made a new and very important modification of the hidden-variables theory, the first improvement in that theory in decades. Most of his papers on this were rejected by the physics journals, but their contents are now widely accepted among specialists who work on the foundations of quantum mechanics.
Sciama did what he could to encourage and help Valentini, but there were no academic positions available either in Italy or the English-speaking world for someone whose work focused on foundational problems. Sciama did suggest to Valentini that if he couldn’t publish his growing body of results in journals, he should write a book about them. Without a position, Valentini moved to Rome, where he eventually secured a postdoc at the University of Rome. When that ran out, he stayed in Rome for six more years, in love with the city and one of its inhabitants, supporting himself by tutoring and meanwhile developing his theory and putting the results into his book.13
While many leading physicists admit private misgivings about quantum mechanics, their public stance is that its problems were settled back in the 1920s. A scholarly account of the later work on its foundations does not exist, but I know that since at least the 1950s, the leading journals have only very selectively published papers on this subject, while several journals have excluded such papers by stated policy. The granting agencies and major government foundations have typically not supported this work,14 and university departments have tended not to hire people who are doing it.
This general recalcitrance is partly a result of the move from revolutionary science to normal science in the 1940s. As in a political revolution, the rebellion had to be suppressed if the revolution was to consolidate its gains. In the early years, there had been several competing views and ideologies about the interpretation of quantum theory. By the 1940s, one had triumphed. In deference to the leadership of Niels Bohr, it was called the Copenhagen interpretation. Bohr and his followers had a stake in cutting off debate, and I would not be surprised to learn that they used the levers of academic politics to do so; given their involvement in the invention of nuclear weapons, they were certainly well placed to succeed. But even those who didn’t care about ideology and wanted only to get on with doing normal science had a motive for stifling debate on the subject. Quantum theory was, on the experimental and practical side, a great success, and those forging ahead with it did not want to be bothered by the nagging doubts of those who continued to worry that there were deep problems with how the theory was formulated and interpreted. It was time to move on.
Those doubters who persevered had few choices. Some restyled themselves as philosophers and published long scholarly arguments in philosophy journals. They created a little subculture that at least kept the debate alive. A few who had mathematical talent got jobs in mathematics departments, where they published formal, rigorous work on alternatives to the consensus formulation of quantum mechanics. Others—some of the best people in the field—found professorships at small colleges, where you were not required to get research grants. A few others made physics careers based on work in other fields and from time to time worked on quantum mechanics as a kind of hobby.
One of these “hobbyists” was John Stewart Bell, who discovered a key theorem about hidden-variable theories in the early 1960s. He built his career on good work in particle physics, but now, some years after his death, it is clear that his most important contribution was his work on quantum theory. Bell is sometimes quoted as having said that one should do normal science and spend only 10 percent of one’s time worrying about the quantum theory. When this dictum comes up, my Perimeter colleague Lucien Hardy likes to speculate on how much more Bell might have contributed to science if he had spent more time in the area where he made the biggest impact—except then he would likely have had no job at all.
It is not surprising that through this period very little progress was made on the foundations of quantum mechanics. How could it have been otherwise? Of course, this was often reason enough not to hire, fund, or publish the few people who did make progress.
Now we know how wrong the skeptics were. About twenty
years ago, Richard Feynman and a few others realized that you might be able to make a new kind of computer using quantum phenomena in an essential way. The suggestion was largely unexplored until a more detailed proposal for a quantum computer was made in 1985 by David Deutsch, now at the Centre for Quantum Computation at Oxford.15 There is no more foundational thinker than Deutsch; he was motivated to invent quantum computers by his disquiet with foundational problems in both mathematics and quantum theory. Just how original and clear a thinker he is can be seen in his provocative book The Fabric of Reality,16 in which he elaborates on his many-worlds theories. I disagree with much of what he writes, but I loved it.
In 1994, Peter Shor of MIT, who was then a computer scientist at Bell Laboratories, found a remarkable result, which is that a large enough quantum computer would be able to break any code in existence.17 Since then, money has flooded into the field of quantum computation, as governments do not want to be the last to have their codes broken. This money has supported a new generation of young, very smart scientists—physicists, computer scientists, and mathematicians. They have created a new field, a blending of physics and computer science, a significant part of which involves a reexamination of the foundations of quantum mechanics. All of a sudden, quantum computing is hot, with lots of new ideas and results. Some of these results address the concerns about the foundations, and many could have been discovered anytime since the 1930s. Here is a clear example of how the suppression of a field by academic politics can hold up progress for decades.
In 1999, after seven years of isolation in Rome, Antony Valentini moved back to his parents’ house in London. His family had emigrated from a small village in Abbruzzo; they owned a little store, and they were willing to support him in his work for as long as it took. I met him there that year, when I was a visiting professor at Imperial College, and after discussions with Christopher Isham, head of the theory group there, we decided to offer him a postdoc and bring him back into science. We were able to do this because I had some unexpected and generous support from a donor who happened to care about the foundations of quantum mechanics. I felt that supporting one of the few people who had proved he could contribute new and important results to this field was putting that money to good use. Had I been supported only by funds from the National Science Foundation, I would not have been able to do this. As generous as the NSF has been to me for my work on quantum gravity, sharing the grant with a postdoc working on foundations of quantum theory could have hurt the chances for future funding.
Now Valentini has joined us at Perimeter. He is still working on his hidden-variables book, but in the meantime he has become a leading figure in the field of foundations of quantum theory, an invited speaker at many conferences on the subject. He now publishes regularly, and his most recent work concerns a bold new proposal to test quantum mechanics by observing X rays that originate near black holes.18 Like Julian Barbour, his years of isolation allowed him to engage in scholarly self-education, and there isn’t a more insightful or knowledgeable critic in the whole field of quantum theory.
Keep in mind why Barbour and Valentini could not have accomplished anything had they tried to have an ordinary academic career. During the stage when one is normally an assistant or associate professor, working hard to be published and renowned enough to win the invitations and research grants necessary to get tenure, they were publishing nothing. But they were accomplishing a great deal. They were thinking, and in a deeper, more focused way than an assistant professor can, about a single recalcitrant foundational issue. When they emerged, after roughly a decade, each had a considered, original, and mature viewpoint that led to their quickly becoming influential. The authority gained from having gone through these years of concentrated study and thought and come out of it with something new and important made them essential to people who cared about these issues.
For seers, the need to be alone for an extended period at the beginning of a career, and often in later periods, is essential. Alexander Grothendieck is said by some to be the most powerful and visionary mathematician now alive. He has had a most unconventional career. Some of his major contributions, which were seminal, were not published, but mailed—in the form of letters hundreds of pages long sent to friends and then passed hand to hand among small circles of people who could read them. His parents were refugees from political oppression and war; he grew up in refugee camps after the Second World War. He appeared in the mathematical world of Paris as if from nowhere. After a brief but extraordinarily influential career, he largely withdrew from scientific life in the 1970s, at least partly because he objected to military funding for mathematics. He disappeared altogether in 1991, and although rumor has it that he is living as a hermit in the Pyrenees, his whereabouts are still uncertain. Clearly, he is an extreme case. But you have to see the look of admiration, wonder, and perhaps even a little fear on the faces of some very good mathematicians whenever his name comes up. Here is how he describes some of his experiences:
In those critical years I learned how to be alone. [But even] this formulation doesn’t really capture my meaning. I didn’t, in any literal sense learn to be alone, for the simple reason that this knowledge had never been unlearned during my childhood. It is a basic capacity in all of us from the day of our birth. However these three years of work in isolation [1945–1948], when I was thrown onto my own resources, following guidelines which I myself had spontaneously invented, instilled in me a strong degree of confidence, unassuming yet enduring, in my ability to do mathematics, which owes nothing to any consensus or to the fashions which pass as law. . . . By this I mean to say: to reach out in my own way to the things I wished to learn, rather than relying on the notions of the consensus, overt or tacit, coming from a more or less extended clan of which I found myself a member, or which for any other reason laid claim to be taken as an authority. This silent consensus had informed me, both at the lycée and at the university, that one shouldn’t bother worrying about what was really meant when using a term like “volume,” which was “obviously self-evident,” “generally known,” “unproblematic,” etc. . . . It is in this gesture of “going beyond,” to be something in oneself rather than the pawn of a consensus, the refusal to stay within a rigid circle that others have drawn around one—it is in this solitary act that one finds true creativity. All others things follow as a matter of course.
Since then I’ve had the chance, in the world of mathematics that bid me welcome, to meet quite a number of people, both among my “elders” and among young people in my general age group, who were much more brilliant, much more “gifted” than I was. I admired the facility with which they picked up, as if at play, new ideas, juggling them as if familiar with them from the cradle—while for myself I felt clumsy, even oafish, wandering painfully up an arduous track, like a dumb ox faced with an amorphous mountain of things that I had to learn (so I was assured), things I felt incapable of understanding the essentials or following through to the end. Indeed, there was little about me that identified the kind of bright student who wins at prestigious competitions or assimilates, almost by sleight of hand, the most forbidding subjects.
In fact, most of these comrades who I gauged to be more brilliant than I have gone on to become distinguished mathematicians. Still, from the perspective of thirty or thirty-five years, I can state that their imprint upon the mathematics of our time has not been very profound. They’ve all done things, often beautiful things, in a context that was already set out before them, which they had no inclination to disturb. Without being aware of it, they’ve remained prisoners of those invisible and despotic circles which delimit the universe of a certain milieu in a given era. To have broken these bounds they would have had to rediscover in themselves that capability which was their birthright, as it was mine: the capacity to be alone.19
It is a cliché to ask whether a young Einstein would now be hired by a university. The answer is obviously no; he wasn’t even hired then. Now we are much more profession
alized, and hiring is based on stringent competition among people highly trained in narrow technical skills. But some of the others I’ve mentioned could not be hired either. If we have the contributions of these people, it is because of their generosity—or maybe their stubbornness—in continuing to work without the support the academic world normally gives to scientists.
At first this would seem easy to correct. There are not very many such people, and they are not hard to recognize. Few scientists think about foundational problems, and even fewer have ideas about them. My friend Stuart Kauffman, the director of the Institute for Biocomplexity and Informatics at the University of Calgary, once told me that it’s not hard to pick out the people with daring ideas—they have almost always had at least a few such ideas already. If they haven’t had any by the end of graduate school or a few years later, they probably never will. So how do you distinguish between the seers who have good ideas and others who try but just don’t? This is easy too. Just ask older seers. At Perimeter, we have no problem picking out the few young ones who are worth watching.
But once these people are identified, they must be treated differently from those doing normal science. Most of them are uninterested in who is cleverer, or who is quicker at solving problems presented by mainstream normal science. And if they tried to compete, given how strict the competition is, they would fail. If they are competing with anyone, it is with the last generation of revolutionaries, who speak to them from the old books and papers that no one else ever reads. There is little external that drives them; they are focused on inconsistencies and issues in science that most scientists are willing to ignore. If you wait five years or even ten, they are not going to look good according to the usual criteria. You can’t panic, but you do have to leave them alone. Eventually, like Barbour and Valentini, they will emerge with something that has been worth the wait.