Oppenheimer writer-director Christopher Nolan initially became interested in physicist J. Robert Oppenheimer, the so-called "father of the atomic bomb," back in the '80s thanks to the then prevalent fear of nuclear war and the erudite wordsmithery of pop superstar Sting.

"I first heard about Oppenheimer when I was a kid," says the Inception director, 52, during EW's Around the Table conversation with Nolan and Oppenheimer stars Cillian Murphy, Emily Blunt, Matt Damon, and Robert Downey Jr. "That Sting song 'Russians' refers to Oppenheimer's 'deadly toys.' I was growing up in the U.K. at a time when people were very concerned about nuclear armaments. When I was 12 or 13, myself and my friends were absolutely convinced that we were going to experience a nuclear war at some point in our lives. Oppenheimer stuck with me as a figure and I learned more about him over the years."

One of the things which Nolan learned, and would include in the finished film, was the revelation that the scientists who worked at the Los Alamos-based Manhattan Project believed there was a chance the detonation of the first atomic bomb would cause a planet-destroying chain reaction in the atmosphere. "They couldn't completely eliminate the possibility," says Nolan. "For me, that was kind of the hook. It's such a dramatic moment. I referred to it in my last film, Tenet. (In the 2020 movie, Dimple Kapadia's arms dealer Priya tells John David Washington's character, 'Oppenheimer became concerned that the detonation might produce a chain reaction, engulfing the world.') I'm just very interested in taking the audience into that room, and being there, and kind of living in that moment. What would that have been like to push that button, knowing there was any possibility of that?"

Oppenheimer is based on Kai Bird and Martin J. Sherwin's Pulitzer Prize-winning book American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, which further enlightened Nolan on his subject.

"One of the first things I grabbed hold of from the book, as I was reading it the first time, was you realize that Los Alamos, which would become so important in history, is just this place [where] he and his brother liked to go camping," says Nolan. "That connection, the personal with the historic, I thought was really engaging."

Oppenheimer drops in theaters July 21.

See Nolan and his cast reveal more about the making of Oppenheimer in the full Around the Table video below.

EW's Around the Table interview was conducted prior to the start of the SAG-AFTRA strike.

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