First nuclear reaction. In an abandoned courtyard in the basement of the University of Chicago, Italian physicist Enrico Fermi demonstrated the first controlled nuclear fission reaction in history. Two years earlier, Fermi, along with Hungarian physicist Leo Szilard and German physicist Albert Einstein, had written to President Franklin Roosevelt to warn him of the danger that the Nazis were developing a nuclear weapon. Roosevelt thus launched the US atomic bomb program. Construction of the atomic bomb under the “Manhattan Project” began in 1942. With the demonstration of nuclear fission, Fermi, who had won the 1938 Nobel Prize in Physics, marked one of the program’s first triumphs. In July 1945, the US successfully tested the world’s first atomic bomb and in August dropped two similar devices on Japan. Fermi died in 1954. A year later, the element “fermium” was named in his honor.
