Nuclear Power

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.

Marie Curie discovers the radioactive elements radium and polonium.

Albert Einstein develops the theory about the relationship of mass and energy.

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.

T​he Radiation Detector is invented.

First cloud-chamber photographs of nuclear reactions.

Herman Blumgart, a Boston physician, first uses radioactive tracers to diagnose heart disease.

Harold Urey discovers deuterium aka heavy hydrogen which is present in all natural hydrogen compounds including water.

James Chadwick proves the existence of neutrons.

On July 4, 1934, Leo Szilard filed the first patent application for the method of producing a nuclear chain reaction aka nuclear explosion.

Two German scientists, Otto Hahn and Fritz Strassman, demonstrate nuclear fission.

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.

The Manhattan Project is formed to secretly build the atomic bomb before the Germans.

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.

The United States explodes the first atomic device at a site near Alamogordo, New Mexico - the invention of the atomic bomb.

The United States drops atomic bombs on Hiroshima and Nagasaki.

The first usable electricity from nuclear fission is produced at the National Reactor Station, later called the Idaho National Engineering Laboratory.

Edward Teller and team build the hydrogen bomb.

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.