ABSTRACT
Pauli’s neutron, or neutrino, solved the problem of the continuous energy spectrum and saved the conservation laws. If the neutrino was emitted along with the electron, then a unique electron energy was no longer required by the conservation laws. Two very important developments occurred in the first few years after Pauli’s suggesting the existence of the neutrino. These were Chadwick’s discovery of the neutron, a heavy neutral particle that was a constituent of the nucleus, and Fermi’s theory of β decay. Both of these would play an important role in solving the problems of nuclear structure and in determining whether the neutrino hypothesis or failure of the conservation laws accounted for the continuous energy spectrum in β decay. Gamow summarized the current views of the neutrino—no charge, small mass, and weak interaction with matter. Gamow noted that the evidence supporting Fermi’s theory told us that the mass of the neutrino was far less than the mass of the electron.
