During this period the Hungarian physicist Leó Szilárd, who was residing in the United States at the time, realized that the neutron-driven fission of heavy atoms could be used to create a nuclear chain reaction.
Samtidigt med disse begivenheder indså den ungarske fysiker Leó Szilárd, som boede i USA på det tidspunkt, at den neutron-drevne fission af tunge atomer kunne bruges til at skabe en kædereaktion.