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Reinventing Gravityby John W. Moffat
During my career over the past 50 years, I have seen a significant change in the environment in which fundamental physics research is conducted. At the Perimeter Institute for Theoretical Physics in Waterloo, Canada, where I do my research, there are currently 90 physicists sitting in their offices thinking about how nature is constructed, giving seminar talks, attending international conferences, and publishing scientific papers. In contrast, it is awesome to realize that one of the two monumental achievements in theoretical physics in the 20th century, quantum mechanics, was conceived and developed by less than 20 physicists, concentrated mainly in Europe. Yet today, at any given time of the day, in all the different time zones on the planet, at least 20,000 theoretical physicists are busy at their desks or in conference halls working on fundamental questions in physics. According to a recent count, more than 30,000 physics papers are submitted to the electronic archives administered by Cornell University each year.
What does all this activity mean for the progress of physics? Is it increasing the pace of the discovery of new ideas and deepening our understanding of nature? Or is it stifling creativity in physics and in effect censoring the information being disseminated through scientific journals? Unfortunately, in my opinion, it is the latter situation that prevails today.
It is becoming clear that one serious casualty of this multitude of working physicists is the time-honored peer-review system of academic journals. That is, when physicists write papers on their research and submit them to commercial journals for publication, the journals' editorial boards administrators and selected physicists cannot possibly read the thousands of papers submitted, and send them off to reviewers, or referees. These physicists, working for free and protected from the authors they are reviewing by the anonymity of the system, read the papers and form judgments as to whether or not they should be accepted for publication. This peer-review system, which has been operating for the past 60 to 70 years, has become simply unworkable today. As the numbers of papers and issues of journals have increased at almost exponential speed, it has become increasingly difficult for journal editors to find willing referees who will devote their valuable time for free to review papers. One unfortunate side-effect of this process is that creative research, which attempts to be original and by definition veers away from mainstream research, tends to be rejected, for it requires referees to devote a great deal more time and effort to fully understand the implications of the new research, and to determine fairly whether such research justifies publication.
It is interesting to note that the most famous physicist of the 20th century, Albert Einstein, only faced the anonymous peer-review system once, for a 1936 paper he wrote, with his collaborator Nathan Rosen, disputing the existence of gravity waves in general relativity, Einstein's famous theory of gravitation. This paper, considered controversial at the time, was submitted to the Physical Review, the premier American physics journal then and now, and was duly rejected by the anonymous referee. Einstein wrote an angry letter to the editor, complaining that he had not been warned that he would have to face an anonymous review system when he submitted the paper for publication, and declaring that he would never submit a paper to Physical Review again. He was good to his word, sending future papers only to journals in which the editor made the decision to accept or reject papers. Unfortunately, there are no such journals remaining today. An obvious question arises: Would Einstein have succeeded so phenomenally as a physicist with his typically iconoclastic approach to physics, in which he was usually outside the box of mainstream physics of the day, if he had been subjected to the peer-review system of publication as it exists today? In my opinion, the answer is no.
Because the commercial journal system is breaking down, a serious debate has arisen in the scientific community worldwide about the future of journal publications and how best to disseminate information about new research. There are those who claim that the present system of peer-reviewed journals should be abandoned, and everyone should simply publish online in a non-refereed forum, allowing readers to form their own judgments about the worth of the ideas. On the other hand, others fear that the loss of the peer-review system could lower the standards of published research. One thing is clear, however: the situation has become so untenable that a new way will have to be found over the next few years to report on and disseminate research results.
I have personally experienced a significant change over the past 40 years in how I publish my research. Today, rather than sending a paper directly to a journal, I first submit my papers to Cornell's electronic archives, and after receiving feedback from colleagues and sometimes making changes in the papers, I then submit them to a conventional peer-reviewed journal. Although the archive system does not use the standard anonymous referees, it is not completely uncontrolled: those who submit papers for the first time must be endorsed by an established physicist or astronomer who publishes on the system.
In the 1980s, when I was initially developing my new gravity theory, now called Modified Gravity (MOG), which is an alternative to Einstein's general relativity, my papers developing the basic theory were accepted by the referees and published in physics and astronomy journals. My motivation for modifying Einstein's gravity theory was to see whether it would be possible to construct a gravity theory without the need for so-called "dark matter." Dark matter is the hypothesized, invisible, and so far undetected matter in the universe that is needed to make Einstein's theory fit the extensive data from astronomical, astrophysical, and cosmological observations that show that there is more gravity "out there" than can be accounted for by the theory using visible matter alone. This dark matter, which theoretically increases the amount of gravity, has never been detected in laboratories directly, and its presence in astrophysical phenomena is merely inferred by gravitational observations. But in spite of this, the consensus among physicists and astronomers is that dark matter exists. To the majority of physicists, it seems less radical to accept the idea that as much as 96 percent of the matter and energy in the universe is invisible than to question Einstein's gravity theory! In those early days of developing MOG, my papers showed that the theory was consistent mathematically, and perhaps because this was viewed as simply a mathematical exercise, I did not experience much opposition from anonymous reviewers. Indeed, I can be considered an old hand at the publication business, having published more than 200 physics papers in peer-reviewed journals over the years, with about 3,000 citations of those papers by other physicists writing in similar peer-reviewed journals.
However, the story began to change around 2000, when my research turned from the development of the theory to its verification. My research began to show that the new theory, MOG, could fit the extensive data from astrophysics and cosmology without the need for dark matter. As the possibility of a significant paradigm shift in our understanding of gravitation began to dawn on the physics and astronomy community, then the opposition by the anonymous referees and editors within this community increased. It often came down to a struggle through emails between me and my collaborators and the anonymous referees as to personal opinions about the value of the research, rather than about the correctness of the calculations involved. In my book Reinventing Gravity, I write about this process of struggling to develop and introduce new ideas, and how difficult it has been historically, and even more so today, to influence the prevailing consensus and to shift the current paradigm.
My research on MOG goes against the grain in another respect: the theory is grounded in data, in reality. It contains definite predictions that can be checked out by laboratory experiments and astrophysical observations. Over the past several decades, there has been a strong tendency in theoretical physics to speculate freely about how nature works without confronting the new theories or ideas with experiments or observations. This goes against more than 300 years of the scientific method as begun by Galileo and Newton. At present there is a growing debate about whether theories such as string theory, quantum gravity (marrying quantum mechanics and gravity theory), and the attempt to unify all the forces of nature can ever be tested experimentally. The question naturally arises: is all the current research in these areas more metaphysics than physics? A consensus has built up in the physics community that these mathematical theories are indeed true, even though there is not a single experimental test of string theory, for example, that could indicate whether we are on the right track. The thousands of string theorists writing papers, refereeing colleagues' papers, and citing each other's papers skews the focus of the entire field, making it appear that string theory is "where it's at" in physics today.
In contrast, in my research on modifying Einstein's gravity theory to remove the need for undetected dark matter, I have attempted to confront my new theory of gravity with the extensive data that has been pouring in from astrophysics, cosmology, and astronomy during the last 30 years, and to make predictions of future discoveries. I describe this quest in Reinventing Gravity in plain language, for the interested general reader, without equations.
Yet today, the tide may be about to turn away from metaphysics and towards reality-based physics again. With the opening of the largest physics experiment ever performed, the Large Hadron Collider (LHC) at CERN, Switzerland, a new, fertile ground for fundamental physics research may be opening up. We may be able at last to ground our speculations about the nature of matter and the universe through experimental reality checks. Will the LHC find any new particles to fit into, and thus finally verify, the standard model of particle physics or not? Will the enormous collider finally find dark matter particles or not? Thus, we have two major changes to look forward to in the near future in theoretical physics: a better method of disseminating research, and a return to the time-honored scientific method of confronting theories with actual data.
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John W. Moffat is professor emeritus of physics at the University of Toronto and an adjunct professor of physics at the University of Waterloo, as well as a resident affiliate member of the Perimeter Institute for Theoretical Physics in Ontario, Canada. He earned a doctorate in physics at Trinity College at the University of Cambridge.