Henri Becquerel (1852-1908) French physicist. In 1896 Becquerel discovered that uranium, when placed on a sealed, light-tight photographic plate, exposed the plate, producing an image of the uranium on the developed plate. He deduced that uranium was emitting an invisible but penetrating radiation. In 1903 he shared the Nobel prize for physics with Pierre and Marie Curie. Photograph by Nadar, Paris. Nadar was the pseudonym of Gaspard-Felix Tournachon (1820-1910) French journalist, artist and photographer. 19th century.