Nuclear Theory

The dazzling complexity of the material world can, for almost all purposes, be reduced to a simple trinity: the proton, the electron, and the neutron. The neutron, a component of the nucleus of every atom except that of hydrogen, was the last of the trinity to be discovered, in 1932. Had they all been a little younger, the scientist who uncovered the neutron might have met on the battlefields of World War II. Brian L. Silver. The Ascent of Science (1998)