Zack Sharf Digital News Director 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.”