Christopher Nolan and Robert Downey Jr., known for their work in successful superhero films, have finally collaborated on the movie "Oppenheimer." Despite their paths crossing briefly on "Batman Begins," it took a biopic about a physicist in the 1940s to bring them together. The film has achieved significant box office success, critical acclaim, and multiple Oscar nominations for both Nolan and Downey. In a recent conversation, they discussed their first meeting, their Oscar nominations, and the surprising casting of Downey as a character in the film.