The year was 1932, in the brief interim between two world wars. The Great Depressionwas near its nadir. In the US, unemployment was approaching 25%. Charles Lindbergh’s baby was kidnapped and murdered, and Amelia Earhart became the first woman
to fly solo across the Atlantic. Iraq was established as an independent country, and Franklin Roosevelt won the first of his four presidential elections. The American Institute of Physics was formally incorporated, and it appointed Harold Urey as the founding editor of its first journal, the Journal of Chemical Physics.
Urey was a 39-year-old associate professor of chemistry at Columbia University in 1932. He got off to a quick start that year: On New Year’s Day, Physical Review published “A hydrogen isotope of mass 2,” a letter to the editor by Urey, Ferdinand Brickwedde, and George Murphy that reported the discovery of deuterium. That was the first of four monumental discoveries of 1932. The discoveries of the neutron, the positron, and the disintegration of nuclei by particle accelerators followed in quick succession. Those discoveries promptly transformed the understanding of nuclear structure and demonstrated the reality of antimatter. Six Nobel Prizes are directly traceable to the work done in that one annus mirabilis. In this article, we look back from today’s perspective at those discoveries and their consequences.