Radium experiment, 1904. Artist: Poyet

Radium experiment, 1904. Paths of alpha, beta, and gamma particles from a radium sample placed between the poles of an electromagnet, as used in Marie and Pierre Curie's laboratory, Paris. Continuing the research into radioactivity begun by Henri Becquerel, the Curies discovered two new chemical elements, radium and polonium. In 1903 they were awarded the Nobel Prize for Physics, sharing the award with Becquerel. (Photo by Ann Ronan Pictures/Print Collector/Getty Images)