Source: Information Processing, Mar 2009

Dyson’s drawings as a child

The breakthrough came on summer trips Dyson made in 1948, traveling around America by Greyhound bus and also, for four days, in a car with Feynman. Feynman was driving to Albuquerque, and Dyson joined him just for the pleasure of riding alongside “a unique person who had such an amazing combination of gifts.”

The irrepressible Feynman and the “quiet and dignified English fellow,” as Feynman described Dyson, picked up gypsy hitchhikers; took shelter from an Oklahoma flood in the only available hotel they could find, a brothel, where Feynman pretended to sleep and heard Dyson relieve himself in their room sink rather than risk the common bathroom in the hall; spoke of Feynman’s realization that he had enjoyed military work on the Manhattan Project too much and therefore could do it no more; and talked about Feynman’s ideas in a way that made Dyson forever understand what the nature of true genius is.

Dyson wanted to unify one big theory; Feynman was out to unify all of physics. Inspired by this and by a mesmerizing sermon on nonviolence that Dyson happened to hear a traveling divinity student deliver in Berkeley, Dyson sat aboard his final Greyhound of the summer, heading East. He had no pencil or paper. He was thinking very hard. On a bumpy stretch of highway, long after dark, somewhere out in the middle of Nebraska, Dyson says, “Suddenly the physics problem became clear.” **What Feynman, Schwinger and Tomonaga were doing was stylistically different, but it was all “fundamentally the same**.”

Related Resources:

The Guardian, Mar 2020

The young Dyson reported that his happiest ever school holiday – from Winchester college – was spent working his way, from 6am to 10pm, through 700 problems in Piaggio’s Differential Equations. “**I intended to speak the language of Einstein**,” he said in his 1979 memoir Disturbing the Universe. “I was in **love with mathematics** and nothing else mattered.

NY Times, Feb 2020

Richard Feynman, a young professor at Cornell, had invented a novel method to describe the behavior of electrons and photons (and their antimatter equivalent, positrons). But two other physicists, Julian Schwinger and Sin-Itiro Tomonaga, had each independently devised a very different way. Each of these seemed to satisfy the requirements of both quantum mechanics and special relativity — two of nature’s acid tests. But which one was correct?

While crossing Nebraska on a Greyhound bus, Dr. Dyson was struck by an epiphany: The theories were mathematically equivalent — different ways of saying the same thing. The result was QED. Feynman called it “the jewel of physics — our proudest possession.”

Information Processing, Dec 2009

It’s been said that Quantum Electrodynamics or QED is the most successful theory science has ever produced, having been verified in some cases to an accuracy of 12 decimal places. It was worked out by two geniuses, Feynman and Schwinger, but their theories looked totally at odds—one used diagrams the other formal analysis.

In perhaps your most celebrated piece of physics, you showed they were equivalent. I’m curious, did Feynman and Schwinger grasp immediately what you had done?

Tim O’Reilly, Mar 2020

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.**

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.

*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.*

*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 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. *