Variation and Diversity: A Tribute to Freeman Dyson

Theoretical Physics

Freeman Dyson, who died this February at the age of ninety-six, was an extraordinary man. He was extraordinarily brilliant and extraordinarily lucky. His upper-middle class English family included a father who was a conductor and composer, and later knight of the realm, while his mother trained as a lawyer. Both were lovers of literature, Chaucer, and poetry. Educated at Winchester College, the most intellectual of the English “public” schools, he went on to Cambridge University at the age of fifteen and then to graduate school with Hans Bethe at Cornell in the U.S. where he had another great stroke of luck. He first read about and then encountered the authors of two apparently incongruent ideas about quantum electrodynamics (QED). The first was intricately mathematical, proposed by theoretical physicist Julian Schwinger; the second was intuitive and graphical, the product