He, along with the other theoretical Physics professors at Berkeley, refused to sign the McCarthy era loyalty oath on principle, and in 1950 went to Princeton to work for Bell Labs where he did research on superconducting materials.
He refused to sign the McCarthy era loyalty oath on principle. This was along with the other theoretical Physics professors at Berkeley. He went to Princeton. This was along with the other theoretical Physics professors at Berkeley, in 1950. This was to work for Bell Labs where he did research on superconducting materials.