IN THE SUMMER of 1962, I was invited to Hamilton, Ontario, to give a talk on my current work in particle physics at the annual meeting of the Canadian Association of Physics. I took a train from Baltimore to Hamilton, and spent a week there at the conference. Robert Marshak, who was then chair of the Physics Department at Rochester University, arrived at the meeting an hour before my talk to chair the session, and I was impressed that soon after the session, he took off in a taxi to return to Rochester. This contrasted with my week-long stay, which surely made it appear as if I had nothing more important to do with my time. I hadn’t learned how to create the image of being an important and busy physicist. I regret to say that after fifty years as a physicist and professor, I still haven’t learned how to play this game.
The next year, in 1963, a letter arrived from Harry Welsh, chairman of the Physics Department at the University of Toronto (U of T), inviting me to apply for a position there, and to visit the university and give a lecture. He had heard from U of T physicists who had attended the conference in Hamilton that I might be a good addition to the Physics Department. This time I flew from Baltimore to Toronto via New York. There was no particle physics group in the University of Toronto Physics Department at that time, and Professor Dick Steenberg, a nuclear theorist, wanted to establish one. In fact, he and Harry Welsh had in mind that I could start a particle physics group.
Soon after my return to Baltimore, I received a second letter from Harry Welsh, offering me a position as associate professor with tenure. This was quite unusual, for the usual academic route begins with the position of assistant professor without tenure, and then typically, after five years, one would be considered for promotion to associate professor with tenure, and then after several more years, one could entertain the possibility of being promoted to full professor. So I was able to short-circuit five years of waiting for tenure. Probably one of the reasons for this generous offer was that I was going through a very creative period in my physics, and had published more than a dozen particle physics papers in the Physical Review during 1961–63 on what was then cutting-edge research in particle scattering theory, S-matrix theory and Regge poles. After some serious deliberation and discussions with Bridget, and eager to have a more secure position to support my family, I accepted the Toronto offer.
In July 1964, we drove from Baltimore to Toronto in my old Jaguar. Bridget and I rented an apartment in a rather uninspiring suburb on the west side of the city, near the airport. I was faced with the prospect of having to give lectures starting in September. I had never taught a course to students or had any teaching duties until then. In fact, I had never even officially taken a course at university! At Cambridge, I had sat in on two courses, but never turned in assignments or took an exam. I was apprehensive about my new role as a teaching professor. That first year I had to teach a quantum mechanics course to engineers and a graduate course on particle physics and quantum field theory. In addition, I had to give two-hour tutorials on first-year physics in the basement of the old mining building attached to the Physics and Engineering departments starting at eight in the morning. Never at my best early in the day, this tutorial was what I dreaded the most about my new job. In addition to teaching, I needed to keep up my full-time research; I intended to continue producing a large crop of papers. My first year in Toronto was a stressful one, but I managed somehow to give a reasonable account of myself as a teacher and to publish several more particle physics papers.
Over the next few years, I built up a particle physics group at U of T, was promoted to full professor in 1967—the same year that our second child, Christina, was born—acquired talented graduate students and survived the turbulent 1960s on a large North American campus. In 1968, when I was thirty-six, Harry Welsh, still chair of the department, asked me to join a three-person committee to create a new physics curriculum. This turned out to be an arduous task, and put extra strain on me as I continued teaching my courses, doing my research and supervising graduate students. But the new curriculum was a success, and remained the model for the core undergraduate teaching in the Physics Department for decades. I considered it ironic that, despite my never having taken a physics course for credit in my life, I was able to help formulate this successful undergraduate teaching program at what was now one of the major physics departments in Canada.
In my research during those early years in Toronto, I continued working on S-matrix theory and other aspects of particle physics such as the then-popular Regge poles, alone and with my graduate students.
In 1972, I was eligible to take a sabbatical leave, and I chose to go back to Cambridge. I had been away from Cambridge for fourteen years, and having now achieved a respectable position in academia and some renown as a physicist, perhaps subconsciously I desired to relive my student days. The leave was to last a year. We lived in a rented flat, and our older daughter, Sandra, attended school in Cambridge.
During that sabbatical year, I was invited to a winter school on particle physics held at a ski resort in Schladming, Austria. I looked forward to this eagerly, as a chance to combine physics with my favourite sport. The physics part of the week consisted of a course of lectures on S-matrix, Regge poles and scattering theory. Since I was considered an expert on these topics, the organizers of the school had invited me to give talks about them.
At the first morning of my lectures, which began at one of my least favourite times of the day, eight-thirty in the morning, a stocky young German student, Bruno Renner, approached me as I was standing at the podium ready to begin. I had eaten some Wiener Schnitzel the evening before that had upset my stomach, and I was feeling a little off colour. Renner looked up at me and said in a German accent, “Professor Moffat, why are you giving these lectures on S-matrix and Regge poles? We students are no longer interested in this subject. We’re now doing quantum field theory and current algebra.” The latter subject was closely related to quantum field theory and group theory, and was being promoted by Murray Gell-Mann.
I looked down at Renner morosely and thought, “This is a great beginning to a week’s lectures.” As it turned out, the sentiments of the students at the physics-ski school correctly predicted the course of particle physics during the 1970s, when quantum field theory took over, and then the next dominant theme, string theory, dominated in the late 1970s and 1980s. Regge poles and S-matrix research had not fulfilled the promise that many of us felt they had in solving fundamental problems concerned with the nuclear forces.
Fortunately, my interests in quantum field theory while a student at Cambridge, and my publishing papers on the subject in the 1960s when I was at RIAS, made it possible for me to disentangle myself from the specialized subject of the analytic S-matrix and Regge poles, and to move into quantum field theory and new developments related to the weak interactions of particles. Many of my colleagues who had become specialists in S-matrix theory were not able to make the transition to the new fad, and the bells could be heard tolling for the end of their research careers.
This was another lesson to me about the brutality of physics: Modern physics develops through fads, often with many hundreds of physicists involved in the process. We can see this clearly in string theory today, where hundreds of string theorists at any given time are writing papers on string theory, and all citing one another’s papers, which makes it appear that strings is the most important place to be in physics today.
This is in stark contrast to the past, when, for example, the revolution of quantum mechanics in the 1920s was accomplished by only a handful of theoretical physicists such as Wolfgang Pauli, Werner Heisenberg, Niels Bohr, Albert Einstein, Max Born, Erwin Schrödinger and Pascual Jordan. Also in contrast to string theory (a mathematical construct so far without experimental verification) and other speculative branches of research today, the creators of quantum mechanics paid close attention to experiments while developing the theory.
Although my physics was proceeding well, my marriage with Bridget did not survive the 1972 sabbatical. Later that year, I met an American physics graduate student, Margaret Buckby, at a conference. After Bridget and I separated, Margaret and I got together, and she moved to Toronto and entered the graduate school at U of T to complete her Ph. D. in experimental nuclear physics.
In 1974, I invited Murray Gell-Mann to Toronto for a week. Gell-Mann had won the Nobel Prize in 1969 for his many contributions to particle physics. He became well known for his 1964 paper introducing the quark model, “A Schematic Model of Baryons and Mesons,” which revolutionized our understanding of the smallest constituents of matter. I had met Gell-Mann previously at conferences, but had not had the chance to spend much time with him. I went out to the Toronto airport to meet him. He entered the arrivals lounge toting a heavy suitcase, inordinately large for his physique. I offered to help him carry it, but he declined.
“What do you have in that bag, Murray?” I asked.
“This is my brain,” he said. “I carry all my physics papers with me, and I have to prepare my talks while I’m in Toronto.”
At the Four Seasons Hotel in downtown Toronto, I ushered him up to his suite, and then we proceeded down to the restaurant, choosing a corner table. Up until then, we had been discussing politics, the weather and Toronto traffic as I drove him to the hotel. We ordered something to eat, and suddenly the discussion switched to physics. Murray began to look tense, and the next thing I knew, he had planted his feet on my knees under the table! I was astonished; I felt as if I had suddenly slipped into a surreal parallel universe. Gell-Mann had unusually large feet for his stature, and his heavy brown leather shoes pressing on my knees was uncomfortable. What did this mean? And what was I to do? This famous physicist, father of the quark model, was my guest for a week at the university. There seemed to be two choices: I could tell him to take his feet off my knees, risking an embarrassing scene, or I could simply pretend that it wasn’t happening, and continue talking about physics. Fortunately, I chose the latter option. After a while of talking physics, Murray seemed to relax in my presence. Possibly he felt that he had succeeded in dominating me intellectually. In any case, he removed his feet from my knees. Neither of us made any comment about the incident.
During the week, Murray displayed admirable professional behaviour. Although our particle physics group at U of T was small compared to the one at Caltech, where Murray was a professor, and other major centres for particle physics in the States, he put great effort into preparing a series of four lectures for the Physics Department students and professors. The lectures revealed a remarkable depth and breadth of knowledge of the subject, and were brilliant in their exposition. Gell-Mann reviewed all the important aspects of particle physics up until that time. His performance during these lectures clearly demonstrated why he was such a dominant figure in particle physics.
In the middle of the week, during one of his lectures, a secretary slipped into the seminar room and told me she had an important message for Professor Gell-Mann. Murray excused himself and left the lecture room for about fifteen minutes. When he returned, he announced that he had just had a phone call from a colleague at Caltech saying that the J/psi particle—in effect, the “charm” quark— had just been discovered independently at both the Stanford and Brookhaven accelerators. He then gave a spontaneous and brilliant discourse on this fourth quark. The J/psi resonance actually consisted of a charm quark and an anti-charm quark bound together. The name “charm” had been coined for the fourth quark in a paper by James Bjorken and Sheldon Glashow in late 1964. Murray also explained why the discovery of the charm quark was significant, and the role it played in the quark model that he had invented in 1964.
I already had some familiarity with this new quark. During a visit to the University of Wisconsin in Madison in 1964, where I attended a summer school in particle physics, I had written a paper proposing a fourth quark, constructed a fractionally charged quark model and extended it to include quantum spin and Gell-Mann’s original three fractionally charged quarks. I didn’t think up a sexy name for the quark—to follow the first three “flavours” called “up,” “down” and “strange” —but I called it simply the fourth quark. The paper, opaquely titled “Higher Symmetries and the Neutron-Proton Magnetic-Moment Ratio,” was published in 1965 in Physical Review. (Glashow and Bjorken’s 1964 paper on the fourth, “charm” quark did not assign fractional charges to any of the quarks, and neither did other papers suggesting a fourth quark.)
One day during Gell-Mann’s visit, we walked to a Hungarian restaurant on Bloor Street in Toronto. Over lunch, I asked him whether it was easier for him to publish papers now that he had a Nobel Prize and was world-famous. Murray became visibly upset and said, “Absolutely not! It’s never easy! Every paper has its own problems.”
He then told me the story about how he submitted his famous paper on the quark model to the Physical Review Letters, and it was rejected. He said that he was very angry about this, and even though it was late at night in Geneva, he phoned Leon van Hove, the director of the theory group at CERN, who was also an editor of Physics Letters B in Europe. Van Hove was not pleased about being phoned so late, and irritably asked Murray what he wanted. Murray said that he wished to submit a paper to Physics Letters B. Leon asked what it was about. Murray explained that it was about his idea that protons and neutrons were each made up of three particles. “What are these particles called?” Leon asked.
“They’re called quarks,” Murray answered, “named after the statement ‘Three quarks for Muster Marks!’ in James Joyce’s Finnegan’s Wake.”
According to Murray, there was a silence at the other end of the phone line. Then Leon asked, “What properties do these particles have?”
Murray answered that they had fractional electric charge. Again there was silence. Fractional electrical charges for particles were unheard of at that time—particles had charges of either +1 like the proton, -1 like the electron or zero like the neutron—and van Hove must have thought the idea was absurd. Murray asked van Hove whether it would be a good idea to submit a letter explaining this model to Physics Letters B.Van Hove did not think it was a good idea, Murray told me. However, Murray did submit the letter, it was published, and it became an important part of the reason that he was awarded the Nobel Prize in 1969.
As it turned out later, a young post-doctoral fellow at CERN, George Zweig, had independently discovered the same idea around the same time. He named the three particles making up the proton and neutron “aces,” after the playing cards, and like Gell-Mann, he assigned them fractional charges. He also worked out important consequences of the quark/aces model for particle physics. Van Hove played an unfortunate role in this story, for when Zweig presented his paper to the CERN theory section for review, to get their permission to publish it in a journal, the permission was denied, and the paper remained unpublished for several years. One of the rules of the Stockholm Nobel Committee is that the Nobel Prize is only awarded on the basis of research papers published in peer-reviewed journals. However, the Nobel Prize was awarded to Gell-Mann not only for his celebrated paper on quarks, but for his contributions to the classification and interactions of elementary particles. Unfortunately, Zweig never received the Nobel Prize for his revolutionary contribution to the standard model of particle physics.
At a small party held to honour his presence at the University of Toronto, Gell-Mann and I were standing with a group of physics colleagues, and he suddenly said to me, “John, I understand you were born in Denmark.”
When I confirmed this, he said, “Speak some Danish.”
I made some benign comments in Danish, never thinking that Murray would understand what I was saying. But to my astonishment, he repeated what I’d said in Danish, and then corrected a word that I had used, saying that it didn’t sound right to him.
I laughed and exclaimed, “Murray, I’m bilingual in English and Danish. How can you correct me?”
Then he asked me, “Where were you born in Denmark?”
“In Valby, on the outskirts of Copenhagen.”
Gell-Mann exclaimed, “Aha! That explains it! I learned to speak Danish over a period of six weeks, living in Fredricksberg.”
Fredricksberg is a district next to Valby, and indeed Fredricks-berg Danish differs in subtle ways from the Danish spoken in Valby. I then realized that Gell-Mann was not only a genius in physics but also in linguistics. I had heard that he spoke several languages well and had the ability to pick up a language with unbelievable speed. In fact, after spending a week with him, I felt that Murray Gell-Mann was one of the most remarkable people I had ever met.
There were other famous visitors to the University of Toronto. In 1978, the committee organizing the annual Welsh Lectures, honouring our former chair, Harry Welsh, called for invitations for outstanding physicists to come and give public lectures. I proposed Sheldon Glashow and Abdus Salam. This was during the time of serious jockeying for the Nobel Prize honouring the development of the electroweak model, the theory that combined into one the electromagnetic force and the weak force. Both Glashow and Salam were becoming well-known for their work on this theory. They both accepted our invitation, and came as my guests together to Toronto for one week. They both gave review talks about particle physics and the recent developments in electroweak theory.
I had seen Salam in 1976, when early in that year I attended a high-energy physics conference at the University of Chicago. In a session on new developments in the electroweak model, I sat near the front of the auditorium next to my old supervisor, who wore his usual heavy overcoat and floppy fedora, even in the warm room.
I briefly told him about my new ideas on modifying Einstein gravity, based on Einstein’s nonsymmetric field structure. Recently I had resumed working on gravity theory and relativity, along with my particle physics research.
Salam thought for a few moments and then said, “Well, John, Einstein’s general relativity is so successful experimentally, it’s hard to see how you could succeed with such a theory. But good luck with it anyway.”
At that point we had to turn our attention to the speaker, Benjamin Lee, who was discussing recent results in developing an electroweak model of weak interactions. During the talk, he kept referring to the “Glashow-Weinberg model,” and I could feel the tension rising in Salam. Every time this happened, Salam would clear his throat with a loud “Harrumph!” of indignation at the speaker not mentioning his name as an author of the electroweak model.
A few months later, I stopped at Imperial College on my way through London to visit the Rutherford Laboratory near Oxford, where I was conducting summer research with collaborators on scattering theory. I was in an office preparing my talk on pion-pion scattering, when the door burst open and Salam stormed in. He thrust a letter at me with a trembling hand and exclaimed, “John, read this!” The letter was very short:“Dear Benjamin, If you continue to ignore my work publicly and do not give me credit for developing the electroweak model, I will personally ruin your career.” It was signed “Abdus Salam.”
Astonished, I said, “Abdus, you cannot send this letter. It is simply unacceptable.”
Salam tore the letter out of my hand, and said, “I’ll send it if I want to. I refuse to put up with this. I deserve credit for my work!” He stormed out of the office, slamming the door behind him. I never discovered whether Salam sent that letter to Benjamin Lee. Tragically, Lee, his wife and child died in a car accident driving home from a physics laboratory in the United States not long after my conversation with Salam.
During his visit to Toronto in 1978, Salam seemed unusually concerned about my old 1964 paper on the fourth quark with fractional charges. The fourth quark played an important role in the development of electroweak theory. Interviewing me about it heatedly in my office one afternoon, he accused me of attaching the “wrong” electric charge of -1/3 to the fourth quark, instead of +2/3. He was upset with me about this. I had no idea why Salam was so exercised about this paper—and he was right about the incorrect electric charge—but later I thought that the paper might have played a minor role in the Nobel Committee’s discussion about who was to get the prize, and who wasn’t, for the electroweak theory. I still don’t fully understand what the implications of this paper were.
Finally, in 1979, the Nobel Prizes began coming in for the elec-troweak theory. That year, the year after Glashow and Salam visited Toronto, the Nobel Committee awarded the prize for physics jointly to Glashow, Steven Weinberg and Salam for their development of the electroweak model and, in Glashow’s case, for other contributions to particle physics. The prize was given for the electroweak theoretical model even though the particles that were crucial to prove the model, the W and Z bosons and the Higgs particle, had not yet been detected experimentally. The W and Z bosons were not detected until 1983, and Carlo Rubbia and Simon van der Meer, who led the team of experimentalists at CERN who found them, were awarded the Nobel Prize the very next year. At this writing, the Higgs particle has still not been detected.
My personal life took another turn in 1982, when I met Patricia Ohlendorf, who interviewed me for a science story on my modified gravity theory for a Canadian newsmagazine. With my own children, Sandra and Tina, then twenty-two and fifteen, I soon became a stepfather to Patricia’s children, Derek and Tessa, who were then eight and six. Patricia and I were married in 1986.
In the years 1986 to 1993, I went through a burst of creative activity in my physics research. I ceased working on conventional calculations in particle physics, and developed riskier, more innovative ideas in cosmology, particle physics and gravity. I tended to adopt a contrarian position in physics, pushing against the current dominant paradigms and fads because I was curious about how robust they actually were.
Alan Guth, then of Stanford University, started one cosmology fad in 1981, called “inflation.” This idea solved certain theoretical problems that attended the birth of the universe by having the universe suddenly inflate exponentially. There was no hard evidence to suggest that this had actually happened 14 billion years ago, and I wondered whether there was a theoretical alternative to the increasingly popular idea of inflation. I was pondering the so-called “horizon problem” : various parts of the early universe were not causally connected because of the limit imposed by the constant speed of light, and this did not fit with the data from the cosmic microwave background (CMB), the evidence in the sky of the afterglow of the Big Bang, which appeared to be so uniform. This raised the following question: How could distant parts of the universe communicate with other parts, as they must have done for the CMB to be so uniform? Inflation did answer this question, by making the early universe prior to inflation much smaller than it was in the original Big Bang scenario, making it possible for light to traverse all parts of the universe.
It occurred to me in a flash that if the speed of light had been very much larger in the early universe, allowing distant parts to communicate with each other almost instantaneously, this would also immediately solve the horizon problem. This scenario meant, of course, that the speed of light would not be a constant, as everyone believed it was, and as postulated by Einstein in special relativity. Rather, the speed of light could vary over time.
Having a radical idea like this takes seconds, but to establish it as a theory requires a detailed mathematical development of the idea. I proceeded, over a period of several weeks, to develop this theory, which I called the Varying Speed of Light (VSL) cosmology, and I arrived at a new modification of Einstein’s special relativity theory and gravitational theory, which was needed to support the idea of a very fast speed of light in the early universe. In the process, I went against the conventions of physics once again: in technical terms, I violated the symmetry of special relativity, the Lorentz transformation, which played a crucial role in the development of special relativity. I published my VSL model in 1993 in the International Journal ofModern Physics D,with the title “Superluminary Universe: A Possible Solution to the Initial Value Problem in Cosmology.”
Another idea I worked on during those years, with my graduate student Darius Tatarski, was inventing a new model of cosmology that was based on an inhomogeneous solution of Einstein’s gravitational field equations, first discovered by Georges Lemaître and Richard Tolman in the 1930s, and developed further by Hermann Bondi at Cambridge a decade later. Astronomers had observed large cosmic voids in space, areas containing very little matter and surrounded by filaments of galaxies. I found these voids to be pro-foundly significant in cosmology, and wondered if I could construct a cosmology model in which we were located within one of these voids. Tatarski and I found from our calculations that when light from distant galaxies passes through a void, it becomes dimmed and makes it appear that the galaxies are farther away than one would estimate them to be using the standard cosmology.*This occurs because the spacetime inside the void is expanding faster than outside, where most of the matter is present. We published this research in the Physical Review in 1992 and the Astrophysical Journal in 1995.
My void model actually predicted the startling observation in 1998 by two groups of astronomers, in Australia and the United States, that distant supernovae undergoing cataclysmic explosions appeared to be farther away than they should be according to the standard cosmology. That is, the light from the supernovae was surprisingly dim. The astronomers concluded that the expansion of the universe in the wake of the Big Bang was actually accelerating— that’s why the supernovae appeared to be farther away than expected— and they suggested that the cause was what later came to be called “dark energy,” which acted as a repulsive force driving the acceleration.
In my void model, the expansion of the universe is not accelerating, and there is no dark energy. The supernovae only appear to be receding, an illusion created by the void we inhabit. My model also predicted that Einstein’s problematical cosmological constant is zero, and therefore has nothing to do with the apparent accelerating expansion of the universe. Most astronomers and physicists accepted the idea of dark energy quite readily in 1998, and the idea of a void cosmology was not popular. A major reason for this was because the void model violated the so-called Cosmological Copernican Principle, which holds that our solar system, our planet, and we as human beings do not occupy a special, central place in the universe. In my void model, it is necessary that we as observers are near the centre of the huge void, which does put us in a special place in the universe.
However, what is known as the standard model of cosmology— based on a homogeneous solution of Einstein’s equations, in which Einstein’s cosmological constant produced the accelerated expansion of the universe—also suffers from a violation of the Cosmological Copernican Principle, but in terms of time, not space: the accelerating expansion of the universe supposedly commenced about 5 billion years ago, when our solar system was being formed. Given that the universe is about 14 billion years old, this seems a rather absurd coincidence.
Attempts to verify or falsify the Cosmological Copernican Principle have so far failed, because to falsify the principle, we would have to make measurements in other parts of the universe, which for obvious reasons is difficult. The violation of the Copernican Principle raises one of the most serious questions in modern cosmology: Do we, in fact, inhabit a special place in space or in time, or both? This obviously has significant implications for philosophy, religion and our understanding of our place in the universe.
In the late 1980s and early 1990s, exploring another topic altogether, I developed a new kind of relativistic quantum field theory, which was based on non-local fields. This was a highly complex and technically demanding endeavour. In standard quantum field theory, the fields such as the electromagnetic field and the fields associated with the particles of the standard model satisfy what is called “microscopic locality.” That is, events associated with the particles and their fields that are relatively far away do not influence what happens locally. In contrast, my non-local fields at small scales could influence other physical processes not in the immediate vicinity.* This non-locality can be tested by experiments at the Large Hadron Collider at CERN. I published a paper on this new relativistic quantum field theory in Physical Review in 1990.
To satisfy my curiosity about how robust standard paradigms were in particle physics, I also constructed a model of electroweak interactions that did not include the elusive and undetected Higgs particle. Virtually all physicists believed that the Higgs field or particle was necessary to impart masses to all other elementary particles; they fully expected the Higgs particle to be detected eventually in high-energy accelerators. In my model, I only included particles that had been experimentally observed in high-energy accelerators at the time. I did, however, include the “top quark,” which had not yet been detected in 1990, but was a few years later. My first paper on this research was published in a European journal, Modern Physics Letters, in 1991.
Because particle physicists had almost universally accepted the existence of a Higgs particle, my attempts to produce a model without one, even though the Higgs particle had not been detected, was a radical proposal that was not popular with other physicists. In my alternative model, the masses of elementary particles were generated at the quantum level, not by a classical scalar field like the Higgs field. I consider my alternative electroweak theory to be one way that the standard electroweak model could have been envisioned in the first place, back in the 1960s and 1970s. But the original theorists—Glashow, Salam, Weinberg and others—went off in a different direction, and did not incorporate the ideas of quantum field theory as I did.*
In addition to all these outside-the-box projects, I continued to ponder the problem of modified gravity and published papers on my nonsymmetric gravitation theory, NGT, on my own and with many talented graduate students over the years. I had been working on this theory all my adult life, since I was nineteen, and had corresponded with Einstein about his attempts to construct a similar alternative gravity theory. NGT was not a unified theory, aiming to combine gravity with electromagnetism and the forces in particle physics, but was instead a purely gravitational theory. Since 1978–79, I had concentrated on modifying Einstein’s gravitational theory out of intellectual interest alone. Not until 1995 did it occur to me that my modified gravity theory could explain the anomalous behaviour of stars moving in approximately circular orbits in galaxies.
Astronomers had known since the 1930s that the outermost stars in galaxies were moving several times faster than was predicted by Newtonian and Einstein gravity. To explain these observations, without changing the theories, physicists had conjectured that there must be large “dark matter halos” attached to galaxies, which increased the strength of gravity and made the stars move faster. In contrast to this, my modified gravity theory, which contains no dark matter at all, explains the faster movement of stars because the theory has an intrinsically stronger gravity at certain distance scales. I published this work on NGT in collaboration with my post-doctoral fellow Igor Sokolov in Physics Letters B in 1995.
I continued to develop the theory over many years, and by 2006 it reached its final version in a paper published in the Journal of Cosmology and Astroparticle Physics called “Scalar-Tensor-Vector Gravity” (STVG). I gave this theory the popular name “modified gravity,” or “MOG.” By now I have published many papers on MOG with my graduate student Joel Brownstein and my collaborator Vik-tor Toth. The latest, simplest version of MOG is able to explain a large amount of data from the solar system to the outer edges of the universe without postulating the existence of exotic dark matter. The theory opens up the possibility of not having a singularity, or Big Bang, at the beginning of the universe, and it may also change the concept of black holes.
These five major research topics all challenged existing fads and paradigms. Yet the dominant fads, from inflation to dark matter and dark energy, to the standard electroweak model with a Higgs particle, were all based on a consensus in the physics community, not on hard experimental evidence. My alternatives to all these models were not greeted with enthusiasm by most other physicists, even though no obvious mistakes could be found in my calculations, and even though my alternative theories fitted the existing data just as well as the dominant paradigms, and sometimes even better.
Sailing against the current of modern consensus physics, I have often had difficulties getting my papers on these outside-the-box topics published in peer-reviewed, establishment journals. This was not the case with my earlier, thoroughly mainstream research on S-matrix, Regge poles, scattering theory and other topics in particle physics. Most often the referees who read and judged my new papers were themselves members of the mainstream research establishment, and had invested much time and funds in the standard models such as string theory, dark matter, the Higgs model and the homogeneous dark energy standard model of cosmology.
I learned a lot about the sociology of science during those creative but difficult years, as it became obvious to me that modern physics develops by consensus and less and less by observational data. Often, when reading referees’ rejections of mypapers, the message that came through loud and clear was: “I cannot find anything wrong with this paper, but I do not like it, and I don’t think that most physicists would be interested in these ideas.”
When I submitted my first paper on VSL,my alternative to inflation, to Physical Review in 1992, the referees chosen by the journal were scathing. They disliked the fact that I had modified the role of special relativity in Einstein’s gravity theory to accommodate such a large speed of light in the very early universe, and they scorned my heretical suggestion that the speed of light was not a constant. They rejected the paper. I submitted it to a lesser-known European journal, the International Journal ofModern Physics D,which accepted it without any revisions, and it was promptly ignored.
Six years later, two other physicists, João Magueijo and Andreas Albrecht at Imperial College London, came up independently with the same idea of a varying speed of light. They submitted their paper to Physical Review, fought with the referees and editors for months, until finally the paper was accepted. Since then, my original paper has come out of hiding, and the idea of VSL, though it has not yet replaced inflation as the dominant early-universe scenario, is at least an active area of research.* Sometimes, one can simply be too early with a promising, non-mainstream idea.
The fate of my MOG paper in 1979 has an even more unusual and positive twist. When I first submitted “A New Theory of Gravitation” to Physical Review, it was rejected four times by four different referees. They claimed that there was no experimental need for a modification of Einstein’s celebrated gravity theory— which is also what Abdus Salam had intimated to me that morning in Chicago. Also, the referees emphasized that Einstein’s theory was elegant, and any modification would mar the beauty of the theory.
I decided to submit the paper for a fifth time. However, this time I did not receive an outright rejection, but the editor mailed me a manuscript that was a rewritten version of the manuscript I had submitted. The anonymous referee had checked every equation carefully, and had made some changes to the mathematics. At first I was upset to think that the referee had had the temerity to rewrite my whole manuscript without my permission. However, I calmed down after some days, and realized, prudently, that I now was guaranteed publication of the article in Physical Review if I agreed to accept the new version.
I wrote to the editor requesting the name of the anonymous referee, but he refused to divulge his or her identity. When the paper was finally published, I had to admit that the ghost-written version was an improvement over my original one. Over the years, this article has become one of mymost cited ones, as today, thirty-five years later, modifying Einstein’s gravity theory has become an increasingly popular research topic. I still feel a debt of gratitude to that anonymous referee, who had the courage to go against the grain of consensus physics, and I still wonder who this person was.
It wasn’t only the peer-reviewed journals I often had difficulties with, but sometimes I was subjected to the scorn of colleagues and even my friends. For example, when my student Darius Tatar-ski defended his Ph. D. thesis at the University of Toronto on the cosmological void model, the examining committee, composed of my peers in physics and astronomy, ridiculed the whole idea. They claimed it was preposterous that we as observers should occupy such a special place in the universe, near the centre of a void. However, because the papers were published in respectable peer-reviewed journals, and in view of the quality of the research, the committee had no alternative but to award Tatarski his degree.
My new relativistic quantum field theory, too, provided good target practice. In early 1990, I invited Richard Woodard, a professor at the University of Florida at Gainesville, to give a series of lectures on string theory at the University of Toronto. Woodard had turned violently against the current fad, string theory, after studying the theory closely and publishing on it for several years, and I thought it would be interesting for our department to consider Richard’s radical ideas.
Richard and I had lunch one day during his visit at the graduate school cafeteria. Over soup and sandwiches, he asked me what research I was doing at the time. I proceeded to explain my ideas on non-local quantum field theory. I had managed to get a paper on it published in the Physical Review in 1989, and was busy writing a follow-up one. Woodard is a volatile person, subject to outbursts when he feels provoked by physics he disagrees with or feels is simply wrong. “John, this is absolute nonsense!” Richard shouted at me. The graduate students around us at their tables began staring at these two older professors creating a ruckus, for I countered Richard by loudly defending my ideas. I considered Richard to be a brilliant theoretical physicist with awesome technical skills in performing complicated physics calculations. So his immediate negative response to my work—even though it was quite far outside the mainstream box of physics—caused me concern.
Yet a few weeks later, I received an e-mail from Woodard, announcing that he had had an “epiphany.” He had seen the light, realized that my idea about non-local quantum field theory could lead to significant progress in particle physics and proposed that we collaborate. I was delighted, and readily agreed. In the meantime, my second, and seminal, paper on this subject, “Finite Nonlo-cal Gauge Field Theory,” had been accepted by Physical Review and published in 1990.Woodard and I, along with my post-doctoral fellow Dan Evens and Woodard’s graduate student Gary Kleppe, then produced a long and highly technical paper, which was published in Physical Review in 1991, applying my ideas on non-local quantum field theory to quantum electrodynamics.
It is clear from the history of science that real progress in understanding the secrets of nature is often only made through opposing the prevailing paradigms. From Copernicus and Galileo hundreds of years ago to more recent examples—Einstein’s development of general relativity, Gell-Mann and Zweig’s invention of the quark model, even the original ideas by Peter Higgs and others providing the basis of a standard electroweak model—we know that original ideas initially meet with skepticism. It is almost a given that new ways of seeing nature face severe opposition. This is not entirely a bad thing because a paradigm in science should not be changed until a new one has been thoroughly tested over time and survives. There’s a built-in conservative attitude in scientific research, which is as it should be.
Still, it is encouraging to me to see some of my areas of non-mainstream research move a little closer to acceptance, and to see lively areas of research where there was initially scorn. For example, there are now many physicists working on alternative theories of gravity because dark matter and dark energy have become two of the most important problems in modern astrophysics and cosmology. To an increasing number of physicists, the idea that 96 percent of the matter and energy in the universe is invisible is becoming quite troublesome.
Another example is my violation of the symmetries of Einstein’s special and general relativity, which was necessary in creating my VSL cosmology model. Today, violating these symmetries has become a major industry in physics. At a recent workshop at the Perimeter Institute, a physicist was lecturing on this very topic. I put up my hand and asked him, “Why are you violating the symmetries of special relativity?” He answered, “Isn’t everybody doing it?”
In 1998, I was required to retire from the Physics Department at the University of Toronto, as the university had a mandatory-retirement policy then. I wasn’t happy about being forced to retire, both for financial and psychological reasons. I could not imagine stopping my research. The word “retirement” was anathema to me, and still is. Physics for me is as essential as breathing, and life could not continue without my being fully involved in my research. However, I found that not having to teach courses and sit on committees freed up a lot of time for research. I still had my research grant from the Canadian government, and put it to good use travelling to conferences and supporting graduate students or post-docs.
Fortunately, in the same year that I retired, the Perimeter Institute for Theoretical Physics was getting started in Waterloo. It was aiming to become an institute that would conduct research on fundamental physics, much as the giant aerospace and defense company Martin Marietta had established my old fundamental-research institute RIAS in Baltimore decades earlier. I was invited by a colleague, George Leibbrandt, who was on the original board of directors of PI, to be either a member of the scientific advisory council or to participate in the research program. For me this was not a difficult decision. I was excited at the possibility of continuing my physics research in what looked like it could become a cutting-edge research environment.
For the first few years, I commuted to Waterloo from Toronto or from the island in the Kawartha Lakes region that Patricia and I had bought in 1995. But eventually it made more sense to move, which we did in 2003, buying a townhouse in north Waterloo across the road from Mennonite farm fields, a dramatic change from my nearly forty years in downtown, highly urbanized Toronto.
*The standard cosmology is based on the Friedmann-Lemaître-Robertson-Walker (FLRW) spacetime geometry, which describes a homogeneous and isotropic universe.
*An important consequence of my new field theory is that it rid relativistic quantum field theory of the ugly mathematical infinities that plagued it. It also made standard renormalization theory more comprehensible. However, my work also opened up the possibility of a finite quantum field theory in which the non-locality plays a fundamental role. This would remove the need for renormalization theory in particle physics.
*In collaboration with Viktor Toth, I took up this work on an alternative electroweak theory without a Higgs particle again in 2008, basing it on my non-local quantum field theory. However, I later decided that it would be possible to formulate an elec-troweak model without a Higgs particle using only physical local fields that do not violate causality. This could be accomplished by developing a novel, finite formulation of quantum field theory.
*In 1998 and later in 2000 and 2001, I published in collaboration with my student Michael Clayton an elegant reformulation of the VSL theory called bimetric gravity theory. In this theory, the massless photons and gravitons have separate geometrical descriptions in spacetime, connected by a field. This allows for a larger speed of light in the early universe without violating Einstein’s special relativity. Recently, Magueijo and collaborators have investigated this model and have found that it can agree with current observational cosmological data and produce predictions that can distinguish it from inflationary models.