[1] While Dancoff was at Berkeley, Oppenheimer suggested that he work on the calculation of the scattering of a relativistic electron by an electric field.
However, some infinities remained uncanceled and the method (later called renormalization) did not give finite results.
[3] Once they repaired this omission, Dancoff's method worked, and they built on it to produce a theory of QED, for which Tomonaga shared the Nobel Prize in 1965.
)[3][4] During the Second World War, Dancoff worked on the theory of the newly invented nuclear reactors.
In the late 1940s, Dancoff began a collaboration with the Viennese-refugee physician and radiologist Henry Quastler in the new field of cybernetics and information theory.