The letter was for President Franklin Roosevelt, warning of the German potential to build extremely powerful bombs of a new type. Leo Szilard, an escaped Hungarian physicist, took a draft of a letter to Einstein, who, although pacifistic, signed the final version. It was felt that his help was needed to get the American government to make a serious effort at nuclear weapons as a matter of survival. None was more famous or revered than Einstein. It seemed that the military value of uranium had been recognized in Nazi Germany, and that a serious effort to build a nuclear bomb had begun.Īlarmed scientists, many of them who fled Nazi Germany, decided to take action. Within months after the announcement of the discovery of fission, Adolf Hitler banned the export of uranium from newly occupied Czechoslovakia.
The enormous energy known to be in nuclei, but considered inaccessible, now seemed to be available on a large scale. The possibility of a self-sustained chain reaction was immediately recognized by leading scientists the world over. Fermi, among others, soon found that not only did neutrons induce fission more neutrons were produced during fission. The discovery of fission, made by two German physicists, Otto Hahn and Fritz Strassman, was quickly verified by two Jewish refugees from Nazi Germany, Lise Meitner and her nephew Otto Frisch. The world was in turmoil when fission was discovered in 1938. Explain the ill effects of nuclear explosion.Discuss different types of fission and thermonuclear bombs.