What Freeman Dyson taught the world

by Ashutosh Jogalekar

Freeman Dyson combined a luminous intelligence with a genuine sensitivity toward human problems that was unprecedented among his generation’s scientists. In his contributions to mathematics and theoretical physics he was second to none in the 20th century, but in the range of his thinking and writing he was probably unique. He made seminal contributions to science, advised the U.S government on critical national security issues and won almost every award for his contributions that a scientist could. His understanding of human problems found expression in elegant prose dispersed in an autobiography and in essays and book reviews in the New Yorker and other sources. Along with being a great scientist he was also a cherished friend and family man who raised six children. He was one of a kind. Those of us who could call him a friend, colleague or mentor were blessed.

Now there is a volume commemorating his remarkable mind from MIT Press that is a must-read for anyone who wants to appreciate the sheer diversity of ideas he generated and lives he touched. From spaceships powered by exploding nuclear bombs to the eponymous “Dyson spheres” that could be used by advanced alien civilizations to capture energy from their suns, from his seminal work in quantum electrodynamics to his unique theories for the origins of life, from advising the United States government to writing far-ranging books for the public that were in equal parts science and poetry, Dyson’s roving mind roamed across the physical and human universe. All these aspects of his life and career are described by a group of well-known scientists and science writers, including his son, George and daughter, Esther. Edited by the eminent physicist and historian of science David Kaiser, the volume brings it all together.  I myself was privileged to write a chapter about Dyson’s little-known but fascinating foray into the origins of life.

I was extraordinarily fortunate to know Freeman as a friend and mentor from 2009 to his passing in 2020. I first met him in November, 2009, purely as an admirer of his work who had been influenced by his evocative autobiography, “Disturbing the Universe“, when I was in college. Like others I was struck by his unique facility with both science and the humanities. That first meeting over lunch which I described in another piece has left a deep memory. What was really fortunate for me was that we struck up a correspondence for the next ten years or so that involved meeting almost every year as well as dozens of emails discussing books, politics, family and of course, science. He often wanted to know what was happening in my field of chemistry, claiming that chemistry was the one field he did not know much about. We talked about my family and his – six children and sixteen grandchildren – which he said were his first priority in life, before work. Every time he would invite me over for lunch at his perch at the Institute for Advanced Study in Princeton, and the discussion would continue before and after in his office. I don’t remember a single time it lasted anything less than three hours.

Seldom does a day pass when I don’t think of this remarkable man. And I miss him deeply, not just because I miss talking to him but because I think the world needs people like him more than ever, people who are brilliant contrarians but who can think and communicate clearly about complex issues. While it’s impossible to gauge all the minor and major influences that people in your life have on you, I think that my association with him has left a deep imprint regarding how I tend to think about the world at large. So what did I learn from him that has endured? Certainly many of the lessons I imbibed were a testament to his well-known qualities, but it’s worth discussing two of these in particular, qualities that I believe are terribly important for the future of civilization. The first is a spirit of rebellion and the other is a love of diversity.

He was, in the New York Times’s words, a “civil heretic“. One of his best essay collections is titled “The Scientist As Rebel” which begins with the words, “Science is an alliance of free spirits in all cultures rebelling against the local tyranny that each culture imposes on its children.” Unfailingly polite and considerate even when expressing the most outlandish ideas, it was Freeman who could talk with a straight face about ESP being a real phenomenon possibly on the edge of scientific measurement, or about kids growing genetically engineered organisms as pets in their rooms, or about looking for frozen fish in the orbit of Europa, or about life existing forever in an expanding universe.

Behind each of these thought processes was an entirely logical approach, often based on hard calculations. Caleb Scharf’s chapter in the new volume illustrates how Freeman could consider even the most far out ideas and then try to bracket them into the realm of possibility by doing actual calculations on them. He exemplified a quote by his friend and fellow physicist Steven Weinberg who once said, “The problem with our theories isn’t that we take them too seriously, it’s that we don’t.” Another friend, the neurologist Oliver Sacks, said that Dyson’s favorite word was “subversive”. One of his favorite mottos was the motto of the Royal Society – “Nullius in verba”, or “Take nobody’s word for it.”

Of course, an idea being subversive has little to do with it being right or wrong, and it’s worth discussing this connection a bit, both because Freeman often emphasized it and because it was the source of some misunderstandings about his beliefs. Late in his life he became controversial for his contrarian opinions about global warming. As Dave Kaiser documents in the new volume, he was far from being a climate change denier, but he thought that the experts weren’t right about all the details and that the utility of the climate models were often exaggerated. In fact it was our common skepticism about models – in my case models of molecular interactions – that gave us a lot to talk about in our early interactions; we once spent an entertaining afternoon talking about how hard it is to model even water, whether inside clouds or inside cells. Freeman wasn’t denying the utility of models but he understood that models are a poor, simplified representation of reality. In that sense he wasn’t saying that climate change models are wrong in their essence, only that they are wrong in some of their details. And when you are making big policy changes costing billions of dollars and potentially affecting the lives of millions of people, the details matter. It was to some extent a sad casualty of celebrity that actual climate deniers ran with some of his pronouncements and used his stature to support their views. Just like Dave Kaiser I think he could have done more to distance himself from the naysayers, but he repeatedly made the point that he wasn’t an expert and that his objections were general ones.

The noise surrounding the specific topics showcasing Dyson’s subversive, contrarian streak hides a more fundamental point in my opinion. He understood better than most that science flourishes not by consensus but by exception. It flourishes best at the fringe, where facts meet speculation. That does not mean that consensus is always wrong, but it’s important to note that consensus only comes much later, after a lone voice in the wilderness has had an idea. There is consensus about Darwin’s theory of evolution today, or about the Big Bang theory, but that’s now. At the beginning there was Darwin, and there was George Gamow, and there were Arno Penzias and Robert Wilson, and that’s all there was. All these scientists were challenging the status quo and were contrarians who thought differently. As a society we owe it to ourselves to encourage such contrarians if we are to reap the benefits of novel, out-of-the-box thinking and new science and technology. Dyson was only following a tradition going back to the Royal Society and before. Nullius in verba.

The second quality that Freeman vividly exemplified was diversity in the broadest sense of the term. It’s a theme that resonates in all his writings, most notably in his Gifford Lectures which were published as “Infinite in All Directions“. He respected both science and religion, both abstract science and practical engineering, both capitalism and socialism, both higher education and the lack of it, both professional science and amateur science. He wrote about all of these things. His efforts to bridge science and religion were recognized by being awarded the Templeton Prize. He wasn’t a formally religious man, but he recognized a quote attributed to Einstein that to thrive, humanity needs both science and religion. He importantly said that religion is not all about faith and much more about a sense of community. Science is also about a sense of community.

In science too he championed diversity. One of his most elegant essays is titled “Birds and Frogs“. Frogs are scientists who revel in solving particular problems and jumping around in the mud of complexity. Birds are scientists who like to survey the landscape from high above and build grand unified theories. Albert Einstein was a bird, Enrico Fermi a frog. Although he called himself a frog, Dyson was clear that science needs both frogs and birds. Another example of Freeman’s love of diversity was how he recognized the critical role of tool-driven scientific revolutions and not just the idea-driven ones described by Thomas Kuhn in his famous work, “The Structure of Scientific Revolutions”. And tools are often built by amateur scientists without formal education, the best example being many of the men who founded the Royal Society. In fact Freeman was always partial toward amateur scientists and engineers. Unlike some ivory tower scientists who might sneer at get-their-hands-dirty engineers, Freeman worked on actual engineering problems ranging from an intrinsically safe nuclear reactor called TRIGA to the outlandish but fascinating scheme Project Orion whose goal was to built a nuclear bomb-propelled spaceship. One of his favorite characters from the history of science was Bernhard Schmidt, a one-armed Estonian optician whose design for a telescope revolutionized astronomy.

There’s a deeper reason for respecting diversity which is to recognize the merits of all sides, an approach that is sorely needed today. Why pick sides between science and religion when both are important? Why pick between socialism or capitalism when society can benefit from a little bit of each system? Why pick between tools and ideas, frogs and birds or amateurs and professionals when all are critical for the future of science? In that sense Freeman was supremely egalitarian, and his lessons should be taken to heart by all of us to want to build a truly inclusive scientific community and society, based not just on diversity of race, gender and nationality but on the diversity of different modes of thinking and viewpoints. It is an enduring legacy.


In what follows, I provide brief summaries of the chapters in the new volume.

In “The Secret Club of Heretics and Rebels”, Amanda Gefter provides a vivid snapshot of Dyson’s childhood. Born in 1923, he was the son of two distinguished members of the English upper middle class. His mother was a lawyer and social worker, his father George was knighted for his contributions as a composer. Freeman who was a child prodigy grew up immersed in books and numbers and being exposed equally to C. P. Snow’s “two cultures” of science and the humanities: this exposure set him on his unique path as purveyor of both abstruse mathematical theories and thorny human problems. Gefter describes his experience as a top student at two hallowed British institutions – Winchester College (which, among other alumni, counts the recent newly elected Prime Minister of Britain, Rishi Sunak) and Cambridge University. Dyson really came into his own at Cambridge where he got to know such scientific greats as G. H. Hardy, Paul Dirac and Nicholas Kemmer. The chapter ends with Dyson winning all the school prizes and climbing the university steeples.

In “Calculation and Reckoning”, William Thomas talks about Dyson’s experience during World War 2 as a statistician at Bomber Command. This was a formative influence in his life. It exposed him to the tragedy of war, the hubris and flaws of the people who make it and the limitations of technology in solving problems related to wars. In many ways Dyson’s interest in reducing conflict, commitment to advising the U.S. government and finding peaceful uses for weapons of mass destruction stems from this experience.

In “The First Apprentice”, Dave Kaiser deftly teases apart Dyson’s most famous scientific contribution – his unification of two disparate theories of quantum electrodynamics and his creation of a set of practical tools that have allowed physicists to reach the most accurate agreement between theory and experiment in all of science. Kaiser describes Dyson’s early association with two great physicists, with Hans Bethe as a graduate student and with Richard Feynman as a colleague: both men became lifelong friends and mentors. It was Dyson’s wizardry with quantum electrodynamics as a young 24-year-old that made him famous and won him an appointment as a permanent member at Princeton’s Institute for Advanced Study from Robert Oppenheimer; all without ever getting a Ph.D. And it was this work that led Feynman in a seminar – after another colleague had praised the “beautiful theory of Feynman and Dyson” – to whisper loudly to Dyson what became the title of this volume – “Well, Doc, You’re In.” Kaiser has also written a wonderful book that expounds on Dyson’s scientific and cultural contributions to quantum electrodynamics.

In “A Frog Among Birds”, Robbert Dijkgraaf surveys Dyson’s enormous contributions to mathematical physics. One of the most important aspects of being a scientist is to recognize your strengths and weaknesses, and Dyson very early on realized that this real strength was in picking problems where elegant mathematics might make a difference. As Dijkgraaf describes, these problems included deep puzzles in diverse branches of physics. One of Dyson’s most original contributions was to provide a comprehensive mathematical solution to a seemingly simple question – why is matter stable? But Dijkgraaf also talks about another, non-scientific but equally important role that Dyson played – that of mediator. As perhaps the only member of the institute who was equally at home in the two cultures, he brought together warring factions and played an important role in establishing the place as a haven for both sciences and the humanities.

In “Single Stage to Saturn”, George Dyson leads us through Freeman’s fascinating work on Project Orion which sought to design a spaceship powered by exploding nuclear bombs (this effort is also documented in George’s first-rate book, “Project Orion“). As far-fetched as this exercise sounds, as George describes, there is no greater testament to Freeman’s awesome powers of mathematical calculation and creativity. The project was scuttled because of concerns about fallout and funding, but I think it’s still waiting in the wings, waiting for the time when escaping earth for the stars sounds less of an outlandish fantasy and more of an imminent necessity.

In “Dyson, Warfare and the Jasons”, Ann Finkbeiner talks about Freeman’s career-long contributions to advising the U.S. government on national security issues as part of an elite group of academic scientists called the Jasons. Although much of the group’s work was classified, enough has trickled out to ensure that Freeman’s work is recognized. In one important project, he helped develop the idea of adaptive optics that can correct telescopes for the effects of atmospheric turbulence and bring it into the public domain. In other projects, he helped assess the reliability of the U.S. nuclear weapons stockpile without explicit testing and tried to figure out how to keep census data safe. He was a member of the Jasons until the end, valued for his stature and his gentle nature and more importantly for his out-of-the-box, contrarian ideas.

In “A Warm Little Pond”, I describe Freeman’s original theories on the molecular origins of life. Unlike many theories which see the processes of replication and metabolism (roughly corresponding to nucleic acids and proteins) as interlinked, Freeman characteristically cut through the complexity required of these scenarios and instead suggested a separate origin for replication and metabolism. Using simple mathematical models he showed how metabolism could survive without replication and how replication could survive without metabolism. Some of his ideas have been quietly incorporated into modern work in the field without the practitioners even realizing it: there is no better evidence in my opinion of how a scientist’s ideas can organically become part of a standard edifice.

In “The Cosmic Seer”, Caleb Scharf explores the unfolding of Freeman’s creative mind on the grandest possible cosmic scales. From Dyson spheres that can help advanced alien civilization trap their sun’s energy to a rigorous argument for how life can survive in an expanding universe to “gravitational machines” that can harness the gravitational energy of white dwarfs and neutron stars for all kinds of purposes, the chapter is perhaps the best example of how Dyson could apply rigorous mathematical calculation to the most outlandish and astonishing cosmic phenomena. The lesson from Dyson’s work is that it’s perfectly respectable to work on problems at the fringe which most people would consider crazy as long as you can bring a certain degree of rigor to them.

In “A Bouquet of Dyson”, Freeman’s friend and longtime science writer Jeremy Bernstein describes his 50-year friendship with Freeman by drawing on letters and conversations.

Finally, in “Coda: Not the End”, Esther Dyson gives us warm memories of her father who, for all his formidable mind and reputation, was an everyman. I personally don’t remember meeting another scientist who was this eminent and yet so approachable and down to earth. Esther describes how her father was just a regular dad, enabling rather than directing his children, encouraging them to run around and just be kids instead of constantly engaging them in scientific conversation, retaining his childhood curiosity with them until the end. His attitude toward his children mirrored one of his central philosophies: “We are scientists second and human beings first, because knowledge implies responsibility.”