 He became interested in ultraviolet photolysis and worked with his doctoral advisor, Roscoe G. Dickinson, on an instrument to find the energy of ultraviolet light.It worked by shining the ultraviolet light onto a thermocouple, converting the incident heat into electricity, which drove a galvanometer.After receiving a Ph.D. in photochemistry in 1928 for this application of quantum theory to chemical reactions, Beckman was asked to stay on at Caltech as an instructor and then as a professor.