Otto Laporte (July 23, 1902 – March 28, 1971) was a German-born American physicist who made contributions to quantum mechanics, electromagnetic wave propagation theory, spectroscopy, and fluid dynamics. His name is lent to the Laporte rule in spectroscopy and to the Otto Laporte Award of the American Physical Society.
Laporte’s ancestors came from French Huguenot families who fled to Switzerland in the 17th century. His father was an officer in the military. Before World War I, they were stationed in the fortified cities of Mainz (where Laporte was born), Cologne, and Metz, in which he received his early education. After the war started, they returned to Mainz.
In the spring of 1920, the family moved to Frankfurt, staying just one year, where Laporte attended the University of Frankfurt. There, he was influenced by the mathematicians Arthur Schoenflies, Ludwig Bieberbach, and Ernst Hellinger, and the physicists Max Born, and Alfred Landé. In the summer of 1921, the Laporte family moved to Munich, where Laporte became a student of Arnold Sommerfeld at the Ludwig Maximilian University of Munich (LMU). Max Born had sent an enthusiastic recommendation of Laporte to Sommerfeld. At that time, Wolfgang Pauli was an assistant to Sommerfeld and Sommerfeld’s students included Werner Heisenberg, Gregor Wentzel, Karl Herzfeld, and Paul Peter Ewald – all of whom would go on to become famous physicists in their own right. Laporte’s first independent research was on the diffraction of electromagnetic waves around a spherical body and this was the basis for his doctoral thesis under Sommerfeld. His doctorate was granted in 1924. While at LMU, he also analyzed various spectra and made a contribution to understanding atomic structure. Through these research efforts, he discovered in 1925 what is known in spectroscopy as the Laporte rule, which specifies that electronic transitions which conserve parity are forbidden.
When Sommerfeld was a visiting professor in the United States, he learned about the International Education Board fellowships set up through the Rockefeller Foundation. Sommerfeld heartily recommended Laporte for a fellowship, which was granted to him for two years starting in 1924. Laporte used the fellowship to do postdoctoral studies and research at the National Bureau of Standards in Washington, D.C. There, he was influenced by William F. Meggers, Gregory Breit, Merle A. Tuve, Paul D. Foote, F. L. Mohler, Arthur Ruark, and Harold Urey.
After his fellowship, Laporte was invited, in 1926, to the University of Michigan by Harrison M. Randall, chairman of the physics department. Laporte served as an instructor for one year and then was promoted to assistant professor. It was the intention of Randall to build up the theoretical physics capabilities at Michigan, so in 1927 Laporte was joined by George Eugene Uhlenbeck, Samuel Abraham Goudsmit, and David M. Dennison, who remained at Michigan for many years.
In 1928, Laporte was invited as a guest lecturer at the Imperial University of Kyoto. While in Japan, he got an urgent message from Sommerfeld, who was going to the United States and wanted Laporte to lecture in his place at LMU. Laporte had to cut his visit short and make a two-week, non-stop trip via the Trans-Siberian Railway in order to arrive in Munich in time. His next visits to Japan were as a lecturer at the University of Tokyo, on leave from Michigan, in 1933 and 1937; during these periods, he learned to speak Japanese and understand their culture. In between these visits, in 1935, he became a naturalized citizen of the United States. From 1954 to 1955, and again from 1961 to 1963, he was a scientific advisor to the American Ambassador in Tokyo. His activities resulted in a landmark atomic energy agreement between the United States and Japan, and he was cited by the U.S. State Department for his key contributions. Between his foreign services in Japan, he served the United States in Germany. From 1949 to 1950, Laporte was an intelligence analyst for the U.S. Army of Occupation in Heidelberg.
It was in 1944 that Laporte added a new area to his professional activities – fluid dynamics, which includes the sub-field of hydrodynamics. That year, he published a paper giving an exact solution to the problem of the lift of an airfoil of elliptical outline. Two years later, he conducted experiments in fluid dynamics with an advanced design shock tube facility put together under Lincoln Smith at Michigan. When Smith left in 1946, Laporte took over the facility. The shock tube allowed him to make spectroscopic measurements in new regions through the shock heating of gases. The addition of fluid dynamics to his research activities was in reality a convergence of a number of his professional interests in quantum mechanics and spectroscopy. And his time at LMU influenced this, as Sommerfeld had done work in hydrodynamics and Heisenberg’s doctoral thesis was on hydrodynamics. Laporte was one of the charter members of the American Physical Society’s Division of Fluid Dynamics, and he served as the division's chairman in 1965.
Laporte had a number of hobbies, which included playing the piano and horticulture, specializing in plants of the cactus and the euphorbia families.
Otto Laporte died in 1971 in Ann Arbor, Michigan of stomach cancer leaving Adele Laporte (wife) and daughters Claire Laporte, Irene Laporte (now Irene Plenefisch) and Marianne Laporte.