Arrival in the U.S.
Engineering physics at Lehigh University, 1926-1930; graduate work in physics at University of Wisconsin, 1930-1934; Ann Arbor summer school, 1934;
Early interest in physics in South Dakota: early training as a physicist, Univ.
Early career through 1939.
Natural radioactivity; ideas of nuclear constitution, size in 1920s; Gamow-Condon-Gurney theory of alpha decay 1928; discovery of neutron 1932; Cam