Los Alamos National Laboratory

Los Alamos National Laboratory

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In Memoriam

Honoring Los Alamos National Laboratory Fellows and their contributions to the institution.

Freeman Dyson

(Dyson photo)

Freeman Dyson, an American intellectual giant with a long interest in nuclear deterrence, passed away on Feb. 28. He was 96 years old.

For more than 50 years, Dyson advised Los Alamos and the DOE and DOD on nuclear deterrence matters through his service on the JASON defense group. These annual studies include assessing our innovations in transformative defense technologies; assessing threats to the U.S. and our laboratory's science-based solutions to mitigate these threats; and advising on the laboratory's nuclear weapons and materials research directions. He was particularly valued for his ability to question received-wisdoms and suggest unanticipated solutions.

He was a quiet and self-effacing man who loved to talk about his passions (visionary science and technology and history); a contrarian who enjoyed poking fun at received wisdom.

Dyson was born in Berkshire, England, in 1923 and studied mathematics at Cambridge. During the war, he analyzed Royal Air Force data from British air bombings and he would later talk and write on how militarily-ineffective were these campaigns.

After the war, Trinity College Cambridge appointed him as a Fellow (what we would call a professor) without him first getting a doctorate. “Why bother!” he said. He subsequently moved to Cornell on the advice of G.I. Taylor, the great mathematician and turbulence researcher who worked at Los Alamos during the war. It was there that he met leading scientists who had been at Los Alamos: Hans Bethe, Robert Wilson and Richard Feynman.

Dyson thought about and wrote on nuclear weapons throughout his career. He would say that he heard about the accomplishments made in the Manhattan Project “right from the horse’s mouth” — from Bethe, at the beginning of his career. In January 2020, he wrote an article in the New York Review of Books on Ted Taylor, a Los Alamos primary weapons designer from the 1950s. Scientists from that era, including Mel Thieme and Pat Cadenhead, were responsible for innovations leading to tactical weapon miniaturization that had an enduring influence on the stockpile.

Dyson was most famous for his 1949 work on quantum electrodynamics, explaining the equivalence of the theories of Schwinger and Tomonaga, and Feynman, and he was the first to emphasize the importance and use of Feynman’s diagrams.

His other contributions are extensive. He designed the first TRIGA nuclear reactor, a small and safe design in use in universities around the world. He would say how disappointed he was that the U.S. did not build and test a large variety of reactor concepts so as to optimize the best choices for different applications, and instead quickly focused on one design.

Another important work was his theoretical insights into the fundamental basis for the stability of matter. This topic arose at a recent JASON review of aging work at the labs: before discussing how certain materials can degrade over time, it is interesting to understand why matter is so stable in the first place (Pauli’s exclusion principle was his answer).

Dyson, like his old colleague Sid Drell, hoped that the world would abolish nuclear weapons. He advocated bold steps for unilateral disarmament of strategic weapons. He was encouraged by George H. W. Bush’s removal of tactical nuclear weapons from Europe and from ships at the end of the Cold War, followed by a similar response by Gorbachev.

Although he knew that others viewed such a future step as naïve, he remained self-confident yet courteous in these discussions. He said of our weapons designers that they “command your respect because they really know the stuff in a way I never will. They believe what they have been doing makes sense.”


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