In this 100th episode of the television program “Science in Action,” which was broadcast in 1953, UC Berkeley and Berkeley Lab’s Glenn T. Seaborg speaks to Al Ghiorso about the discovery, in 1940 and the years following, of transuranic elements such as plutonium. The “Science in Action” program was created in 1949 by the California Academy of Sciences as a half-hour program on a specific scientific topic, presented by the Academy’s curator of the Steinhart Aquarium, Earl S. Herald along with an expert on the show’s subject. It ran for 16 years and included interviews with several Nobel Laureates.