when did the discovery of the atom happen
Geiger–Marsden experiment Accolades soon flooded in. Hantaro Nagaoka, who had once proposed a Saturnian model of the atom, wrote to Rutherford from Tokyo in 1911: "Congratulations on the simpleness of the apparatus you employ and the brilliant results you obtained". The conclusions of these experiments revealed how all matter on Earth is structured and thus affected every scientific and engineering discipline, making it one of the most pivotal scientific discoveries of all time. The astronomer Arthur Eddington called Rutherford's discovery the most important scientific achievement since Democritus proposed the atom ages earlier.[11]
History of nuclear weapons In January 1933, Adolf Hitler was appointed Chancellor of Germany and it quickly became unsafe for Jewish scientists to remain in the country. Leó Szilárd fled to London where he proposed, and in 1934 patented, the idea of a nuclear chain reaction via neutrons. The patent also introduced the term critical mass to describe the minimum amount of material required to sustain the chain reaction and its potential to cause an explosion. (British patent 630,726.) He subsequently assigned the patent to the British Admiralty so that it could be covered by the Official Secrets Act.[2] In a very real sense, Szilárd was the father of the atomic bomb academically. Also in 1934, Irène and Frédéric Joliot-Curie discovered that artificial radioactivity could be induced in stable elements by bombarding them with alpha particles; Enrico Fermi reported similar results when bombarding uranium with neutrons.