Martin Kamen, a physicist who in 1940 co-discovered, with Sam Ruben, the isotope carbon-14, a crucial dating tool for biochemistry, was born in Toronto on this date in 1913. Three years after their discovery, Kamen was assigned to work on the Manhattan Project at Oak Ridge, Tennessee. In 1945 he was accused of leaking nuclear weapons secrets to Russia, and struggled for more than a decade to clear his name and regain his passport, an ordeal he described in his 1985 memoir, Radiant Science, Dark Politics. Kamen’s troubles began, according to an obituary in The Guardian, when he “asked a colleague who ran the cyclotron machine to prepare radioactive sodium for an experiment. When Kamen opened the container of sodium, he was surprised that it was glowing purple, signifying a much more intensely radioactive batch than could be produced in a cyclotron. He deduced immediately that the sodium must have been irradiated in an atomic reactor elsewhere in the laboratory. Because of security, he not been told of its existence. In his excitement, he blurted out his belief to colleagues. Shortly after, an investigation was launched . . . and Kamen was sacked shortly afterwards.” Among his many rewards, in 1996 Kamen shared the Enrico Fermi Award for lifetime achievements in energy research — awarded by the U.S. Department of Energy, which oversaw the laboratory that had fired him.

Kamen “helped lay a foundation for deciphering the chemical processes in plants and animals …  ‘The whole world changed,” said Dr. Arthur B. Robinson of the Oregon Institute of Science and Medicine, who was a doctoral student of Dr. Kamen. ‘Before [carbon-14], nobody could make any progress with biochemistry.”–Kenneth Chang, New York Times