Saturday, June 27, 2020

Thinking Big With Freeman Dyson: Project Orion

The writer is Professor Emeritus of Physics at the Stevens Institute of Technology.
From Inference Review:
As the reader will learn, my friendship with Freeman Dyson goes back well over half a century. I never stopped marveling at his genius. He simply could not help seeing things in a unique way. The last communication I had with Freeman not long before he passed away had to do with climate change. He was concerned about the next ice age, which he thought was long overdue, and about which he was certain that no one really understood the science. Only Freeman would worry about a forthcoming ice age. As part of this essay, we are fortunate to be able to publish something he wrote about space travel and which is typical Freeman.

In the fall of 1957, I arrived at the Institute for Advanced Study (IAS) in Princeton to begin what turned out to be a two-year stay. I had spent that summer as an intern in the Theoretical Division at Los Alamos. Everyone who worked in the Theoretical Division was required to obtain a Q clearance, the highest level of security clearance in use at the Department of Energy and the Atomic Energy Commission. It was a prerequisite for anyone working in close proximity to nuclear weapons and was only granted after an elaborate FBI background check.1 Q clearance holders were also authorized to receive classified information on a need-to-know basis. When I arrived at the IAS, I still held an active Q clearance. Despite having interned at Los Alamos, my knowledge of nuclear weapons was limited. None of the projects I had been involved with had any connections to the weapons program. At the end of the summer, I had been able to observe a couple of nuclear tests in Nevada, but I had no detailed knowledge of how the devices themselves actually worked.

At the Institute that fall, I became good friends with another physicist who was about the same age. Michael Cohen had obtained his degree at Caltech under the supervision of Richard Feynman, a rare distinction. Cohen was both very smart and very self-confident, two qualities he would have needed to succeed at Caltech. He later told me that, while he was getting his degree, he had consulted for the RAND Corporation in Los Angeles, a think tank that worked on nuclear strategy, among other topics, but that also did physics. Cohen suggested that he might be able to get me a summer job there. I took up his offer, and in June 1958, I found myself in Santa Monica, not far from the beaches of the Pacific Ocean. At first glance, the structure that housed RAND’s research facility in Santa Monica looked a bit like a small college campus. It had a tennis court and people ate lunch on tables outside. It was only when you got inside that you began to realize that its entire mission seemed to be devoted to nuclear war.

The security at RAND was even tighter than at Los Alamos. A pass had to be shown to gain access to the offices of the theory group, and an armed guard would frequently inspect the area to make sure that classified documents had not been left unattended. In one of the offices, a small seismograph was used to observe the tremors induced by hydrogen bomb tests in the Pacific. The nuclear theorist Herman Kahn was a notable presence at the facility. A larger-than-life figure in more ways than one, Kahn appeared to spend much of his time trying to convince anyone within earshot that the US could win a nuclear war. Kahn once loaned me the manuscript of a book he was working on. When I read it, I thought he must surely be joking. It was perhaps fitting that Kahn became one of the main sources of inspiration for the eponymous Dr. Strangelove in Stanley Kubrick’s film.

The longer I spent at RAND, the more obvious it became that there was not really anything much for me to do. The only work of any consequence that I was involved in during my time at the facility involved adding up a long column of numbers that apparently had some relevance to a nuclear test proposal. It did not take long before I began to feel that I was wasting my time.

Joining Orion
Freeman Dyson had been a hero of mine since graduate school. When I was first trying to understand quantum electrodynamics, I had attempted to read Feynman’s papers. I found them incomprehensible. I then tried to read Julian Schwinger’s papers. I found them incomprehensible too. It was only when I read Dyson’s paper, “The Radiation Theories of Tomonaga, Schwinger, and Feynman,”2 and the notes from his course on advanced quantum mechanics at Cornell that I finally began to understand what was going on.3 Dyson became a permanent member of the IAS in 1953 and was resident when I arrived there. He was always friendly, but, for the most part, kept to himself. He had lunch with us from time to time but did not say all that much. I once went into his office to ask a question and found him reading the Bible in Russian. He had been studying the language since high school.
My relationship with Dyson was forever changed by the sort of happy accident that occurs all too rarely. I had been in New York and was traveling back to Princeton on the train late at night. By coincidence, Dyson was on the same train. We spoke a little during the trip, and when we arrived in Princeton I offered to give him a lift home in my car. He invited me in, and we had a long talk over a couple of drinks. I was curious about his first mathematical experiences. Dyson told me that when he was still young enough to be put down for naps he began adding in his mind the sequence 1 + 1/2 + 1/4 + 1/16 + … and realized that the sum was converging to 2. He had invented the notion of the convergent infinite series.

Soon after our talk, Dyson left Princeton for his summer job in California. He was working in La Jolla as a consultant for General Atomics, a division of the General Dynamics Corporation. The previous summer in California had been an eventful one for Dyson. On the one hand, he led the design team that developed a class of nuclear research reactors, known as TRIGA (Training, Research, Isotopes, General Atomics), that are still in use to this day.4 On the other hand, during a day trip to Tijuana at summer’s end, he had been bitten by a dog that was thought to be rabid and had been forced to endure all manner of vaccinations as a result. I had no idea what he was working on in the summer of 1958.

All the occupants of our building at the IAS, myself and Dyson included, shared the services of a secretary, Jane Kane. Once a week, she would forward any mail that had arrived and pass on any gossip she had heard. I received a note from her that summer with news of Dyson. He was in La Jolla, as expected, but had recently returned to Tijuana to see a bullfight and was currently working on a design for a spaceship. I immediately to wrote Dyson saying that if either of these things were true, he was certainly having a much better time than I was. A few days later, much to my surprise, Dyson called me. He confirmed that he was indeed working on a spaceship, but quickly added that he could not tell me about it over the phone. Instead, he suggested that I visit him to see the work for myself. This was how I came to join the Orion project.

I still had my Q clearance when I arrived in La Jolla, so Dyson was able give to me a general outline of the project. The following account draws on both my own experiences and a wonderful book written by Freeman’s son George, entitled Project Orion, that was published in 2002.5 The majority of the key figures in the project were still alive when George was researching the book, and his account includes interviews with many of the participants. At the time of writing, nearly twenty years later, there were, as far as I knew, only two surviving members of the project—Freeman and myself.
After Freeman’s passing on February 28, 2020, I may be the only one left.

The Origins of Orion
Stanisław Ulam arrived in Los Alamos in the winter of 1943. He had been recruited to the Manhattan Project by John von Neumann and Hans Bethe. Before traveling to New Mexico, Ulam had been working as an assistant professor at the University of Wisconsin in Madison. He was not told what he would be working on; his instructions were simply to report to Lamy—the railway depot for Santa Fe. Ulam had never heard of Lamy and knew little, if anything, about New Mexico. He later recalled:
I went to the library and borrowed the Federal Writer’s Project Guide to New Mexico. At the back of the book, on the slip of paper on which borrowers signed their names, I read the names of Joan Hinton, David Frisch, Joseph McKibben, and all the other people who had been mysteriously disappearing to hush-hush war jobs without saying where.6

Also at Inference Review:
SARS-CoV-2: Research Guide
122 articles, updated June 1, 2020