Chicago Pile-1, 1942

1942 20th century america atom bomb atomic research bw c p 1 chicago pile 1 chicago pile 1 chicago controlled nuclear chain reaction cp 1 cp 1 december 2 december 2nd event famous first nuclear reactor history human made nuclear reactor manhattan project metallurgical laboratory nuclear bomb nuclear chain reaction nuclear physics nuclear research nuclear weapons research stagg field technology university of chicago uranium and graphite blocks usa weapon research