# Honorary fellows: Professor Freeman Dyson

Born in Berkshire, educated at Winchester College and at Trinity College, Cambridge. Freeman Dyson worked as a statistician at Headquarters, RAF Bomber Command, 1943-1945 and graduated from Cambridge with a BA in mathematics in 1945.

Dyson is most well known for his work in Quantum Electrodynamics, in which he showed the equivalence of Feynman's formulation, based on a diagrammatic representation of the path integral formalism, and the operator method employed by Schwinger, and more transparently by Tomonaga. This work was followed by a proof of the renormalisability of QED, and among the byproducts of Dyson's contribution to field theory are the Dyson series, the Dyson-Schwinger equations and the definition of the time-ordering product operator.

Dyson has also worked extensively on the environmental problems caused by human activity and more generally on climate studies and biotechnology. His speculation, in the paper *Time without end: physics and biology in an open* *universe*, that an intelligent being would be able to think an infinite number of thoughts in an open universe, seems to encapsulate his optimism and open-mindedness.