“It was a gift from the gods we disclosed...” boasted the British scientists sharing their top-secret discovery of a 10-centimeter cavity magnetron with the Americans. That revelation in September 1940 resulted in the creation of the MIT Radiation Laboratory or Rad Lab. “From first to last, the Laboratory lived by the law of cut-and-try.” It was a hybrid laboratory bringing together nuclear physicists, engineers, and skilled technicians. University professors worked side-by-side with researchers from industry and the military. In five years, the Rad Lab developed 150 different systems for radar, navigation, early warning, gun direction, and blind bombing as well as the LORAN navigation system. It grew from 50 to 4,000 employees, employing about one-fifth of the nation’s physicists, and was second in size only to the Manhattan Project. The Rad Lab reshaped MIT in fundamental ways after WWII. It also represents the Institute’s single greatest contribution to the nation in response to a crisis during its 150-year history.