'In February 1954 Robert Oppenheimer invited Yang to present the work at a seminar at the Institute for Advanced Study (IAS) in Princeton, New Jersey. Wolfgang Pauli was present. He had been pursuing a similar thought, but had quit after encountering what seemed to be a show-stopping issue: in such theories, the mass of such a field has to be zero. Pauli knew that in “Abelian” theories, such as quantum electrodynamics (QED), it’s alright if the force-carrying particle is zero; this is indeed what lies behind our understanding of the zero mass of the photon. But extending field theory to had…