Remembering Freeman Dyson
Treasured moments with a genius we will all miss.
Freeman Dyson died last week at the age of 96 after injuring himself in a fall in the cafeteria at the Institute of Advanced Studies in Princeton, where he had continued to work right up to the end. I can’t resist adding to the outpouring of appreciation and love that has ensued. He has an outsized place in my mind and in my heart for someone whom I met in person fewer than a half-dozen times.
When I interviewed Freeman on stage at OSCON in 2004, along with his son George, the subject strayed to digital preservation. I lamented how much would be lost due to incompatible standards for information storage, and he said, “Oh no, forgetting is so important! It is what gives room for new ideas to come in.” This was such a typical Freeman moment: bringing a profoundly fresh perspective to any discussion. Perhaps the most famous example is the paper he wrote in 1949 at the age of 25 making the case that the visualizations of Richard Feynman were mathematically equivalent to the calculations of the more conventional physicists Julian Schwinger and Shin’ichirō Tomonaga, a paper that led to Feynman, Schwinger, and Tomonaga receiving the 1965 Nobel Prize in Physics for the theory of quantum electrodynamics.
This talent Freeman had for seeing to the heart of things was apparent even earlier, when he was working as a statistician in the operations research section of the Royal Air Force Bomber Command during World War II. As recounted in the first of his numerous volumes of autobiography, Disturbing the Universe, he had been asked to study the pattern of bullet holes on the bombers returning to Britain from their forays overseas with an eye to reinforcing the areas with the most anti-aircraft damage. No, no, Freeman argued, reinforcement may be more effective in areas that show little damage in returning planes, because hits to the most vital regions will have caused the planes to be lost! The essential information was to be found in what was missing.
After George sent an email to a group of friends about Freeman’s death, Danny Hillis replied with a story that seems to perfectly encapsulate this gift of Freeman’s for seeing things that others missed. “I visited him recently,” Danny wrote, “and we got into a conversation about self-organizing systems. After lunch we climbed up the long stairs to his office, and when we sat down he seemed a bit distracted. I asked him what was wrong. Well, he said, what seemed wrong was that self-gravitating systems have negative specific heat capacity. The thing to do, he said, was to figure out why that was right.” When the world doesn’t quite make sense, don’t brush the offending observations under the rug. Think harder.
My earliest memory of Freeman, from well before I met him, echoes the distracted air that Danny noticed. In Kenneth Brower’s book The Starship and the Canoe, about Freeman’s work on Project Orion and George’s work reconstructing early native American canoes in the Pacific Northwest, there was an account of the way Freeman would go so deep inside that he wouldn’t notice anyone around him—his interior world of thought was too vivid—and how sometimes, he would even break off in the middle of a conversation. Rude? No, he explained (as I recall it). Would someone think it rude if there were the sound of a car accident outside, and you broke off conversation to run to the window? Sometimes thoughts too are so compelling that you must immediately take notice. For those of us who are cursed (or gifted) with the experience that our interior world is sometimes more real than the outside, demanding all our concentration, this was a heady acknowledgement.
Another moment that I treasure was a fragment of an overheard conversation at the first Science Foo Camp in 2004. He and another physicist were discussing Michael Crichton’s novel Prey, in which the monster du jour was a swarm of nanoparticles. He said something like: isn’t it ridiculous how the nanoparticles are chasing people? Anyone knows that a particle moving in a viscous medium such as air moves at a velocity proportional to its length. (Or some such; I believe he offhandedly referenced a particular formula, which I don’t recall.) I was immediately struck by how differently the world appears to someone so deeply mathematical. We see the world through the lens of our received ideas, but for most of us, words predominate. Freeman had a gift for seeing with both words and numbers, and for throwing both away when needed, to see the world afresh.
Forgetting may be important, but so is remembering and honoring. Freeman was good at that, too. One of my favorite pieces of his writing is his foreword to a collection of Richard Feynman’s essays, The Pleasure of Finding Things Out. It is so good that over the years, I’ve managed to get only about halfway through the book, since each time I pick it up, I first re-read Freeman’s foreword. His account of how he came to write his seminal paper on quantum electrodynamics is the most glorious appreciation of another human being that I have ever read, and shows Freeman at his best: curious, deep, original, humble, kind, thoughtful, and remarkably literary. You can read about Freeman’s life and career in one of the many obituaries, like the one in the New York Times last week, but if you want to experience the man himself, you still can, through the many books and articles he left behind. This is as good a place as any to start:
“I did love the man this side idolatry as much as any,” wrote Elizabethan dramatist Ben Jonson. “The man” was Jonson’s friend and mentor, William Shakespeare. Jonson and Shakespeare were both successful playwrights. Jonson was learned and scholarly, Shakespeare was slapdash and a genius. There was no jealousy between them. Shakespeare was nine years older, already filling the London stage with masterpieces before Jonson began to write. Shakespeare was, as Jonson said, “honest and of an open and free nature,” and gave his young friend practical help as well as encouragement. The most important help that Shakespeare gave was to act one of the leading roles in Jonson’s first play, “Every Man in His Humour,” when it was performed in 1598. The play was a resounding success and launched Jonson’s professional career. Jonson was then aged 25, Shakespeare 34. After 1598, Jonson continued to write poems and plays, and many of his plays were performed by Shakespeare’s company. Jonson became famous in his own right as a poet and scholar, and at the end of his life he was honored with burial in Westminster Abbey. But he never forgot his debt to his old friend. When Shakespeare died, Jonson wrote a poem, “To the Memory of My Beloved Master, William Shakespeare,” containing the well-known lines: “He was not of an age, but for all time.” …
What have Jonson and Shakespeare to do with Richard Feynman? Simply this. I can say as Jonson said, “I did love this man this side idolatry as much as any.” Fate gave me the tremendous luck to have Feynman as a mentor. I was the learned and scholarly student who came from England to Cornell University in 1947 and was immediately entranced by the slapdash genius of Feynman. With the arrogance of youth, I decided that I could play Jonson to Feynman’s Shakespeare. I had not expected to meet Shakespeare on American soil, but I had no difficulty in recognizing him when I saw him.
Before I met Feynman, I had published a number of mathematical papers, full of clever tricks but totally lacking in importance. When I met Feynman, I knew at once that I had entered another world. He was not interested in publishing pretty papers. He was struggling, more intensely than I had ever seen anyone struggle, to understand the workings of nature by rebuilding physics from the bottom up….I seized every opportunity to listen to Feynman talk, to learn to swim in the deluge of his ideas. He loved to talk, and he welcomed me as a listener. So we became friends for life.
For a year I watched as Feynman perfected his way of describing nature with pictures and diagrams, until he had tied down the loose ends and removed the inconsistencies. Then he began to calculate numbers, using his diagrams as a guide. With astonishing speed he was able to calculate physical quantities that could be compared directly with experiment. The experiments agreed with his numbers. In the summer of 1948 we could see Jonson’s words coming true: “Nature herself was proud of his designs, and joyed to wear the dressing of his lines.” During the same year when I was walking and talking with Feynman, I was also studying the work of the physicists Schwinger and Tomonaga, who were following more conventional paths and arriving at similar results. Schwinger and Tomonaga had independently succeeded, using more laborious and complicated methods, in calculating the same quantities that Feynman could derive directly from his diagrams. Schwinger and Tomonaga did not rebuild physics. They took physics as they found it, and only introduced new mathematical methods to extract numbers from the physics. When it became clear that the results of their calculations agreed with Feynman, I knew that I had been given a unique opportunity to bring the three theories together…. My paper was published in the Physical Review in 1949, and launched my professional career as decisively as “Every Man in His Humour” launched Jonson’s. I was then, like Jonson, 25 years old. Feynman was 31, three years younger than Shakespeare had been in 1598. I was careful to treat my three protagonists with equal dignity and respect, but I knew in my heart that Feynman was the greatest of the three and that the main purpose of my paper was to make his revolutionary ideas accessible to physicists around the world. Feynman actively encouraged me to publish his ideas, and never once complained that I was stealing his thunder. He was the chief actor in my play.
Freeman undersells himself. He too was a genius. We will all miss him.