The Day Oppenheimer Feared He Might Blow Up the World

In July 1943, Robert Oppenheimer called Arthur Compton to say he was coming to Michigan, where Compton was on a brief vacation with his wife and son in a lakeside house. He had to talk about a matter so important that it was worth taking the train all the way from Los Alamos, New Mexico.

Compton, a Nobel laureate in physics for his research on the interactions of light and matter, was one of the key scientific architects of the Manhattan Project, the secret operation at Los Alamos during World War II to construct an atomic bomb before the Nazis did. The project was led by Oppenheimer, an enigmatic, chain-smoking American theoretical physicist who had contributed important work in fields ranging from quantum mechanics to nuclear and molecular physics, astronomy to general relativity.

That kind of life-or-death gamble makes for a dramatic movie scene.

When Oppenheimer arrived, Compton drove him to the lake where they could talk in secrecy. In Compton’s later account, Oppenheimer explained that the Los Alamos scientists had discovered that, as well as liberating atomic energy by nuclear fission, very light atoms like hydrogen could release energy by together into heavier nuclei. Such a process would only be initiated at tremendous temperatures—but that is precisely what the fission bombs would produce. If the Manhattan Project