In 1903 the husband and wife team of Marie and Pierre Curie received the Nobel Prize for physics for their discovery of radium. Their research into radioactivity set the stage for a profound revolution in the way humans under-stand the makeup of their world. Albert Einstein in 1905 proved that matter was energy in his famous equation E = mc ² . This equation showed that when matter was transformed into energy, as it did in radioactivity, a very small amount of matter produced a very large amount of energy. By the early 1930s, the structure of the atom was known to be composed of a central nucleus made of positively charged protons and uncharged neutrons; negatively charged electrons orbited the nucleus of the atom like planets around the sun. By the late 1930s, scientists all over Europe were bombarding atoms with neutrons to find out more about radioactivity...