Career
Whilst at the Palmer Physical Laboratory at Princeton University from 1926-1928, he discovered alpha decay via quantum tunnelling, together with Edward Condon and independently of George Gamow. In the early 1900s, radioactive materials were known to have characteristic exponential decay rates or half lives. At the same time, radiation emissions were known to have certain characteristic energies.
By 1928, Gamow had solved the theory of the alpha decay of a nucleus via quantum tunnelling and the problem was also solved independently by Gurney and Condon.