Changes

After Hahn and Strassmann discovered nuclear fission early in 1939, Fermi discovered the possibility of emission of secondary neutrons and of a chain reaction. He devised a classical series of experiments that generated the first controlled nuclear chain reaction, on a squash court beneath Chicago's stadium on Dec. 2, 1942. Fermi then played a key role in developing the first atomic bomb.

After Hahn and Strassmann discovered nuclear fission early in 1939, Fermi discovered the possibility of emission of secondary neutrons and of a chain reaction. He devised a classical series of experiments that generated the first controlled nuclear chain reaction, on a squash court beneath Chicago's stadium on Dec. 2, 1942. Fermi then played a key role in developing the first atomic bomb.