I spent the spring semester of 2005 as a member of the Institute for Advanced Study in Princeton, where Albert Einstein and Kurt Gödel, among others, had roamed the halls, usually after their most creative and productive scientific years. Earlier in my career, I had turned down an offer of a long-term appointment at the Institute, in part because it was too quiet and genteel. Perhaps that is why I gravitated to spending my time there with Freeman Dyson. Always a perfect gentleman, he nevertheless possessed a twinkle in his eye and a wry smile even as he invariably disagreed with whatever you had to say. Freeman died on February 28, 2020, at the age of ninety-six.
I met Freeman most days for lunch, where we sat at a table for two, separate from the two large tables at which most of the other physicists at the Institute sat. At one table sat a cadre of string theorists who worked in the intellectual shadow of Edward Witten. Next to Witten, who is likely smarter than anyone else anywhere, Freeman was the smartest person in the room. But even though Freeman was a superb mathematician—indeed, that was his first formal training—he found he had little to talk about with most of the young string theorists. It was difficult to keep up with the dozens of new papers with highly abstract mathematics that they produced every month. But more than that, he found their style incompatible with his. While he loved mathematics and number theory, he loved thinking about the universe more. And for most of the young people at the next table, our universe was just a rather boring special case of what were likely far more interesting mathematical entities.
At the other table sat a group of young astrophysicists, working under the guidance of an imperial figure in that field, John Bahcall. Freeman found himself interested in astrophysics in his later years, and often attended the astrophysics seminars. But even then, while he loved to think about astrophysics problems, he never really wanted to be a member of any club who would have him as a member.
Freeman began his intellectual career as a mathematician, studying at Cambridge. He returned there as a fellow after the war, writing two papers on number theory. The distaste he felt about having used his mathematical knowledge to analyze the impact of wartime bombing raids, along with the realization that conventional wisdom about the efficacy of bombing was misplaced, drove both his lifelong hatred of war and distrust of so-called experts. It also probably drove him away from mathematics. He moved to the United States to study physics with the renowned Hans Bethe, but spent much of his time learning from Richard Feynman, whom he revered.
Freeman’s greatest scientific contribution came shortly afterward. It ultimately helped ensure Feynman’s renown as a physicist, earning him a share of a Nobel Prize—an award that many of us believe Freeman also deserved to share, except that the arcane rules of the Nobel Foundation limit the number of individuals who can win the prize in any field to three people. What was characteristic about Freeman’s work was that it violated conventional wisdom. Two different formulations of the first true quantum theory of electromagnetism had been developed. One, developed independently by Julian Schwinger and Sin-Itiro Tomonaga, was mathematically rigorous and exceptionally difficult to understand. Another, developed by Feynman, relied on graphical diagrams, and appeared to many to be ad hoc. Freeman demonstrated that these two very different formalisms were in fact completely equivalent mathematically. He subsequently taught much of the rest of the physics community how to work with what became known as Feynman diagrams.
On the basis of this scientific milestone, Freeman first became a professor at Cornell and then moved to a permanent position at the Institute for Advanced Study, where he spent the rest of his career. He achieved these positions without ever having received a PhD. Perhaps that was another reason for his skepticism about expert opinion.
The Institute was the perfect place for Freeman to seek his own path. Unlike many scientists who, well after their most productive scientific years, continue to write slight variations on the same paper over and over again, Freeman decided his best research years were behind him. While he continued to publish scientific papers in a host of different fields, he branched out into writing. As he later put it, “Life begins at fifty-five, the age at which I published my first book.”1
Through his books, he inspired many young scientists, including myself, to try to think outside the box. His classic, Disturbing the Universe, reflected his eclectic and broad view of science and, when it appeared in 1979, helped inspire my own efforts to write about science.2 His hatred of war, combined with his realization that nuclear weapons were a far greater danger than most people believed, led to his book Weapons and Hope, which won a National Book Critics Circle Award in 1984.3
It is hard to find a field in which he worked where he simply furthered the majority viewpoint. He thought that metabolism rather than genetics was the key factor that led to the origin of life. He promoted notions of space travel using nuclear bombs, something that from a theoretical perspective might have seemed interesting, but which from a practical perspective was doomed.4
I suspect that Freeman’s distrust of conventional wisdom was driven not just by his early life experiences in the war, but frankly by a distrust in the intellectual capability of many other experts. He was, after all, smarter, more capable, and more scientifically literate than most of his colleagues. As the Nobel laureate Steven Weinberg observed, “I have the sense that when consensus is forming like ice hardening on a lake, Dyson will do his best to chip at the ice.”5
Speaking of ice—in his later years, Freeman became known as a climate change contrarian. Unlike many climate change deniers, he fully understood that human industrial activity is producing climate change. He disagreed, however, that this was a bad thing, and proposed inventive but ultimately impractical ways to deal with global warming, if necessary, including genetically engineering trees that could sequester carbon. I spent a number of hours debating issues of climate change with him. Ultimately I found that his views—which unfortunately others often distorted and used to justify their own refusal to accept reality—were based on a simple belief that climate experts ignore exotic or unexpected options. While my own explorations of this field suggest his distrust was misplaced, and while I think he ultimately did a disservice to the scientific community by making unfounded claims, his willingness to think outside the box nevertheless provides a very important example in a world of echo chambers and ideological camps. We all need to be willing to risk being wrong, and we all need to be willing to at least consider the unexpected.
Returning to our time together at the Institute, much of that year was spent debating the possible future of life in an eternally expanding universe. There, too, I believe he was ultimately incorrect, but nothing was as invigorating for me as going into his office with what I believed was an airtight argument and having him come into my office the next day and demolish it.
At that time, I often wrote science opinion pieces for various newspapers. It never ceased to surprise me when I came down to lunch with him, proudly presenting him with my latest piece, watching him read it, and then seeing him look up at me, smile, and tell me I was completely wrong.
It was just a week before his death that I sent him my most recent published piece, in which I argued that it is time for the Bulletin of the Atomic Scientists, of whose Board of Sponsors we had both been members, to retire their iconic Doomsday Clock in its present form.6 He wrote back the next day, stating, “I agree with this piece a hundred percent.” I do not think I was ever more shocked, and I am glad he continued to surprise me to the end.
I will miss him, but so should we all. Humanity is poorer whenever a great contrarian passes away.
