The atomic bomb could never have been realized if chain reaction was not possible. From the very beginning when radioactivity was discovered Leo Szilard (1898-1964) had believed that chain reaction is possible and that a very powerful bomb can be created from a runaway chain reaction. His belief prompted him to file a patent in 1934 and assigned it to the British Admiralty for safekeeping. However, at the start of the 1940s after learning the works of Otto Hahn and Lise Meitner on uranium fission, he was concerned that nuclear weapons might be developed by the Nazis. Together with Edward Teller (1908-2003) and Eugene Wigner (1902-1995), they approached Albert Einstein, urging him convincingly to write a letter to President Roosevelt for the likely event of such weapon falling in the hand of the enemy. This began the secretive government funded Manhattan Project to create the first atomic bomb.

In 1942, Szilard worked with Fermi, in Chicago, who at first did not believe that chain reaction is possible but together they built the first atomic test reactor. Szilard then extended the project to the desert of Los Alamos for the first successful testing of the atomic bomb. Near the end of WWII after Nazi Germany surrendered, Szilard had always opposed the idea of actually using the A-bomb on the Japanese empire. At the conclusion of WWII, Szilard became an active advocate for the peaceful use of atomic energy and for international control of nuclear weapons. In 1959, Leo Szilard was awarded the Atoms for Peace medal for believing the peaceful use of controlled chain reaction. But today, who would believe a sustainable chain reaction of cryonuclear fusion for the continuation of an advanced civilized world in many years to come?