Christopher Nolan revealed to Entertainment Weekly that he cast real scientists as extras in “Oppenheimer,” a historical drama about theoretical physicist J. Robert Oppenheimer, the Manhattan Project and the creation of the atomic bomb. The cast is full of stars such as Cillian Murphy, Emily Blunt, Robert Downey Jr., Matt Damon and Florence Pugh, but Nolan made sure to bring in actual scientists for certain scenes to maintain the film’s authenticity.
“We were in the real Los Alamos and we had a lot of real scientists as extras,” Nolan said. “We needed the crowd of extras to give reactions, and improvise, and we were getting sort of impromptu, very educated speeches. It was really fun to listen to.”
Nolan continued, “You’ve been on sets where you’ve got a lot of extras around and they’re more or less thinking about lunch. These guys were thinking about the geopolitical implications of nuclear arms and knew a lot about it. It actually was a great reminder every day of: We have to be really on our game, we have to be faithful to the history here, and really know what we’re up to.”
Murphy added to Entertainment Weekly about the cast, “Every day, you had these phenomenal actors, who are heroes of mine, coming in. Every day, you were having to raise your game to work with these legends. Everybody was so unbelievably well-prepared. Every single actor, no matter what size their role or the significance of their character in history, each one of them had this massive depth of knowledge that they could draw on.”
While Nolan brought real scientists to set, Murphy did not concern himself too much with the science behind the atomic bomb while prepping to play Oppenheimer. Instead, he read everything he could about the man himself.
“[I prepped by doing] an awful lot of reading,” Murphy told The Guardian last year. “I’m interested in the man and what [inventing the atomic bomb] does to the individual. The mechanics of it, that’s not really for me — I don’t have the intellectual capability to understand them, but these contradictory characters are fascinating.”
In his commitment to authenticity, Nolan also found a way to recreate atomic bomb explosions without using CGI. The filmmaker has always favored practical effects over VFX (he even blew up a real Boeing 747 for “Tenet”).
“I think recreating the Trinity test [the first nuclear weapon detonation, in New Mexico] without the use of computer graphics was a huge challenge to take on,” Nolan told Total Film magazine earlier this year. “Andrew Jackson — my visual effects supervisor, I got him on board early on — was looking at how we could do a lot of the visual elements of the film practically, from representing quantum dynamics and quantum physics to the Trinity test itself, to recreating, with my team, Los Alamos up on a mesa in New Mexico in extraordinary weather, a lot of which was needed for the film, in terms of the very harsh conditions out there — there were huge practical challenges.”
“Oppenheimer” is set to open in theaters nationwide July 21 from Universal Pictures.