At the beginning of World War II, Bohr, a great Danish physicist, learned the news of fission reaction from two colleagues who escaped Nazi rule. 1939 At the beginning of this year, Bohr went to America to tell American scientists the news. Szilard, a Hungarian physicist who immigrated to the United States, and others realized that nuclear fission could be used to make atomic bombs with unprecedented destructive power.
The first working atomic bomb exploded.
1939 in the summer, when szilard and others learned that German scientists began to discuss the use of atomic energy and banned the export of uranium ore in Czechoslovakia occupied by Germany, they were very worried. Szilard visited President Roosevelt's friend and personal adviser, economist Saxophone, and then met with Einstein, asking Einstein to sign the letter to President Roosevelt, which was handed over to Roosevelt by Saxophone. This letter expounds the importance of developing the atomic bomb to American security. At breakfast with Roosevelt at the White House, Sachs also told a historical story: Napoleon missed the opportunity to equip the French navy with submarines to defeat Britain because he did not support Fulton, who invented the ship. Roosevelt was moved by saxophone's argument and decided to support the development of the atomic bomb.
1945, 16 In July, the first atomic bomb test was conducted in an isolated area at Alamogordo Air Force Base in New Mexico. The code word for this bomb is "Fat Man". The test result is more successful than expected. 1945 On August 6, the United States dropped its first combat atomic bomb on Hiroshima, Japan, and dropped the second on Nagasaki on August 9.