June 3, 2016
Convergence of atomic spectroscopy and low temperature physics led to a discovery, on Thanksgiving Day, 1931, that soon solved the outstanding problems of nuclear physics and launched a technology that transformed the world. This discovery was a result of a collaboration that began at The Johns Hopkins University, and won the 1934 Nobel Prize in Chemistry for Harold Urey (JHU Associate in Chemistry, 1924-28). Another key collaborator was Ferdinand Brickwedde (JHU B.A. 1922, M.A. 1924, Ph.D. 1925) who was then at the National Bureau of Standards in Washington, DC. Two other legendary JHU physicists made foundational contributions to this discovery: Robert Williams Wood, author of the monograph "Physical Optics" and correspondent of Theodore Roosevelt; and Henry Augustus Rowland, master of the diffraction grating, whose portrait was painted by Thomas Eakins in 1897. I will outline the Thanksgiving 1931 discovery and another that followed in early 1932, with particular emphasis on their long-term impact and the role of the National Bureau of Standards.
Charles Clark is a theoretical atomic and molecular physicist. His main research activities are in the areas of ultracold gases, quantum information and telecommunications, and atomic and molecular phenomena on surfaces, in condensed matter, and in nuclear reactions. He is a Fellow and former Co-Director of the Joint Quantum Institute of the National Institute of Standards and Technology (NIST) and the University of Maryland, and a NIST Fellow in the Physical Measurement Laboratory. He received his Ph.D. in Physics from the University of Chicago in 1979.