The Manhattan Project and Early Strategic Thinking
In 1934, Emilio Segrè and Enrico Fermi, working in Rome, Italy, bombarded uranium with slow neutrons and reported that they had "observed fission" -- that the uranium had broken apart. 1 But anything beyond this glimpse eluded them.
In 1938, Otto Hahn, a chemist at the Kaiser Wilhelm Institute in Berlin, wrote a letter to Lise Meitner, a noted physicist who was living in Sweden as a refugee from Nazi Germany, to tell her that he had repeated Fermi's experiment and had identified barium as one of the lighter elements in the residue. This clue enabled Meitner to work out and announce early in 1939 the theory of nuclear fission -- that when an uranium atom was hit by a neutron it would split into atoms of lighter weight and that this would be accompanied by an enormous release of energy.
The implications were staggering. If enough neutrons were also released when the uranium atom split, they would in turn split other uranium atoms in the pile of uranium around it, and a chain reaction would ensue. The energy released could be used to run steam engines or it could be used to make an explosive of fantastic, almost unbelievable power.
These implications were obvious to any physicist anywhere in the world. Indeed, J. Robert Oppenheimer, who became the director of the Los Alamos laboratories that created the atomic bomb, was fond of telling a story that illustrates the point. He was discussing the news of Meitner's announcement with a faculty colleague in a bar in Berkeley, California, that was frequented by both faculty and students. Oppenheimer's colleague expressed some doubt that physicists everywhere would immediately deduce that an atomic bomb was possible. The two of them made a bet, called over a beginning student in the physics department,