Scientists discovered nuclear energy at the end of the nineteenth century. Within fifty years it became a decisive factor in our war with Japan and has affected international arms policies ever since. .

             The study of nuclear energy began in the nineteenth century when Marie and Pierre Curie discovered the radioactive elements radium and polonium. Before this only uranium and thorium were the only radioactive elements that were known. Radium and polonium were hundreds of times more radioactive than uranium. The Curies won the 1903 Nobel Prize in physics for these discoveries. Seven years later Marie Curie won the Nobel Prize in chemistry for refining radium. She was the first person to win the Nobel Prize twice. .

             Soon after the Curies made their discoveries, scientists discovered the radioactive element actinium. By 1912, thirty radioactive elements had been discovered.

             In 1905, Albert Einstein developed a theory about the relationship of mass and energy. The formula, E=mc2 is probably the most famous outcome from Einstein's theory of relativity. The formula states that Energy (E) equals mass (m) times the speed of light squared. In essence, it means mass is just one form of energy. Since the speed of light is an enormous number, 186,000 miles per second, and in the equation it is squared, a small amount of mass can be converted to a phenomenal amount of energy. Nuclear reactors are based around this theory because small amounts of mass can produce large amounts of energy. .

             In December 1938, two German scientist demonstrated nuclear fission. These two scientists, Otto Hahn and Fritz Strassman, found they could split the nucleus of a uranium atom by bombarding it with neutrons, which are the uncharged part of atoms. As the uranium nucleus splits, some of its mass is converted to energy by Einstein's Law. This discovery spread through the scientific community very rapidly.