Nuclear explosion debris. The first man made nuclear explosion occurred on July 16, 1945 at 5:50 am on the Trinity Test Site near Alamogordo, New Mexico in the United States, an area now known as the White Sands Missile Range. The event involved the full-scale testing of an implosion-type fission atomic bomb. In a memorandum to the U.S. Secretary of War, General Leslie Groves describes the yield as equivalent to 15,000 to 20,000 tons of TNT. Following this test, a uranium-gun type nuclear bomb (Little Boy) was dropped on the Japanese city of Hiroshima on August 6, 1945, with a blast yield
Soviet atomic bomb project Russian scientists, and their American counterparts, that such reaction could have military significance. The discovery excited the Russian physicists, and they began conducting their independent investigations on nuclear fission, mainly aiming towards power generation, as many were skeptical of possibility of creating an atomic bomb anytime soon. Early efforts were led by Yakov Frenkel (a physicist specialised on condensed matter), who did the first theoretical calculations on continuum mechanics directly relating the kinematics of binding energy in fission process in 1940. Georgy Flyorov's and Lev Rusinov's collaborative work on thermal reactions concluded that 3-1 neutrons were emitted per fission only