[2][3] Furry made contributions to the early development of quantum field theory with J. Robert Oppenheimer, Vladimir Fock, and others.

Furry's theorem shows that the amplitude of a Feynman diagram consists of a closed loop of fermion lines with an odd number of vertices, vanishes.

[5] After the war, Furry continued teaching at Harvard, later becoming a full professor and serving for three years as chairman of the physics department from 1965 to 1968.

In early 1954, he dropped the Fifth Amendment defense in a nationally televised hearing before Senator McCarthy and answered questions about himself, but refused to name others.

He later played a significant role in the writing of Irving Emin's Russian—English Physics Dictionary (New York: John Wiley & Sons, 1963), a work that is still widely used today.

13, Propagation of Short Radio Waves, edited by Donald E. Kerr, as a part of the Massachusetts Institute of Technology Radiation Laboratory Series, McGraw-Hill Book Company, 1951.