Humanities › History & Culture Nuclear Power Timeline of Nuclear Technology and the Atomic Bomb Share Flipboard Email Print U.S. Navy Nuclear Test, Bikini Atoll, Marshall Islands. FPG/Getty Images History & Culture Inventions Invention Timelines Famous Inventions Famous Inventors Patents & Trademarks Computers & The Internet American History African American History African History Ancient History and Culture Asian History European History Genealogy Latin American History Medieval & Renaissance History Military History The 20th Century Women's History View More By Mary Bellis Inventions Expert Mary Bellis covered inventions and inventors for ThoughtCo for 18 years. She is known for her independent films and documentaries, including one about Alexander Graham Bell. our editorial process Mary Bellis Updated November 03, 2017 By definition "nuclear" as an adjective means relating to or constituting the nucleus of an atom, for example, nuclear physics, nuclear fission, or nuclear forces. Nuclear weapons are weapons deriving destructive energy from the release of atomic energy, for example, the atomic bomb. This timeline covers nuclear history. 1895 Mrs. Roentgen's hand, the first X-ray picture of the human body ever taken. LOC Cloud chamber for tracking charged particles is invented. Wilhelm Roentgen discovers x-rays. The world immediately appreciates their medical potential. Within five years, for example, the British Army is using a mobile x-ray unit to locate bullets and shrapnel in wounded soldiers in the Sudan. 1898 Marie Curie. LOC Marie Curie discovers the radioactive elements radium and polonium. 1905 Albert Einstein. LOC & Mary Bellis Albert Einstein develops the theory about the relationship of mass and energy. 1911 Georg von Hevesy conceives the idea of using radioactive tracers. This idea is later applied to, among other things, medical diagnosis. Von Hevesy wins the Nobel Prize in 1943. 1913 The Radiation Detector is invented. 1925 First cloud-chamber photographs of nuclear reactions. 1927 Herman Blumgart, a Boston physician, first uses radioactive tracers to diagnose heart disease. 1931 Harold Urey discovers deuterium aka heavy hydrogen which is present in all natural hydrogen compounds including water. 1932 James Chadwick proves the existence of neutrons. 1934 Leo Szilard. Courtesy Department of Energy On July 4, 1934, Leo Szilard filed the first patent application for the method of producing a nuclear chain reaction aka nuclear explosion. December 1938 Two German scientists, Otto Hahn and Fritz Strassman, demonstrate nuclear fission. August 1939 Albert Einstein sends a letter to President Roosevelt informing him of German atomic research and the potential for a bomb. This letter prompts Roosevelt to form a special committee to investigate the military implications of atomic research. September 1942 Atomic Bomb Explosion. Courtesy Outlawlabs The Manhattan Project is formed to secretly build the atomic bomb before the Germans. December 1942 Enrico Fermi. Department of Energy Enrico Fermi and Leo Szilard demonstrated the first self-sustaining nuclear chain reaction in a lab under the squash court at the University of Chicago. July 1945 The United States explodes the first atomic device at a site near Alamogordo, New Mexico - the invention of the atomic bomb. August 1945 The United States drops atomic bombs on Hiroshima and Nagasaki. December 1951 The first usable electricity from nuclear fission is produced at the National Reactor Station, later called the Idaho National Engineering Laboratory. 1952 Edward Teller. Ernest Orlando Lawrence Berkeley National Laboratory Edward Teller and team build the hydrogen bomb. January 1954 U.S.S. Nautilus. U.S. Navy The first nuclear submarine U.S.S. Nautilus is launched. Nuclear power enables submarines to become true "submersibles" - able to operate underwater for an indefinite period of time. The development of the Naval nuclear propulsion plant was the work of a team Navy, government and contractor engineers led by Captain Hyman G. Rickover.