Part 1 of Essay
Scientists in the 1930s, using machines that could break apart the nuclear cores of atoms, confirmed Einstein's formula E=mc² . The release of energy in a nuclear transformation was so great that it could cause a detectable change in the mass of the nucleus. But the study of nuclei -- in those years the fastest growing ar ....

Part 2 of Essay
.... for enormously devastating bombs. They had reason to fear that Nazi Germany might construct such weapons. Einstein, reacting to the danger from Hitler's aggression, had already abandoned his strict pacifism. He now signed a letter that was delivered to President F.D. Roosevelt, warning him to take action. This, and a second Einstein-Szilard letter of March 1940, joined efforts by other scientists to prod the United States government into preparing for nuclear warfare. Einstein played no other role in the nuclea ....