Oppenheimer: Matt Damon Almost Took an Acting Hiatus Before Being Cast

Christopher Nolan's Oppenheimer opens in theaters this week and has a star-studded cast, including Matt Damon, who plays General Leslie Groves, the general who oversaw the Manhattan Project, in the film. For Damon, it's just the latest in a series of films over the past few years, as the actor has had a busy schedule with projects such as Air, The Last Duel, and more. And as it turns out, Damon was planning to take time off from acting because his schedule had been so packed before Nolan called. Damon told Entertainment Weekly, he and his wife have an actual caveat that they agreed on that he would forego time off if Nolan called.

"This is going to sound made up, but it's actually true," Damon said. "I had — not to get too personal — negotiated extensively with my wife that I was taking time off. I had been in Interstellar, and then Chris put me on ice for a couple of movies, so I wasn't in the rotation, but I actually negotiated in couples therapy — this is a true story — the one caveat to my taking time off was if Chris Nolan called. This is without knowing whether or not he was working on anything, because he never tells you. He just calls you out of the blue. And so, it was a moment in my household."

Oppenheimer's Script Was Written in First-Person

For Oppenheimer, Nolan did something a little unusual in terms of writing the film's script. Instead of writing it in third person and thus, an objective point of view, he wrote it in a subjective first-person point of view as though written by the real-life Oppenheimer himself, something that Damon and co-star Emily Blunt said made a major difference in how emotional it was.

"I felt like when I read the script, I remember finding it just really pulse racing and emotional and immersive, and that's clearly his intention. When [Christopher Nolan] wrote it, that it is within the traumatic brain of this one man. That's why it feels like you're left kind of destroyed by it because it plays like a horror movie," Blunt told ComicBook.com.

She continues, "It's so internal, the internal storm of this man the whole way through it. You kind of felt that when you read the script. Then I think because Oppenheimer was so enigmatic and ambiguous and it kept you leaning in. Chris wanted these quite, and they were, big personalities in his life that the characters were very colorful. [Oppenheimer's wife Kitty] was a real fireball, such an extraordinary person, really, not an easy person, but so exciting to play her."

Damon agreed, saying that the film hinged on Cillian Murphy's Oppenheimer from the start and thus, that role needed to be as dynamic as possible.

"Chris was so clear that with the way that it was written in that subjective voice and that the whole movie lived or died hinged on that performance," Damon adds. "The book it's based on won the Pulitzer Prize. It's called American Prometheus, but Chris said, 'I'm not calling the movie that. I'm calling it Oppenheimer because that's our way in.'"

Oppenheimer Recreated the Trinity Test for the Film, But Didn't Actually Detonate an Atomic Bomb

While Nolan worked hard to create much of the visuals in Oppenheimer without CGI, the filmmaker recently clarified that even though he did recreate the Trinity test — the first detonation of a nuclear weapon in 1945 — for the film, he didn't actually set off an atomic bomb.

"It's flattering that people would think I would be capable of something as extreme as that on the one hand, but it's also a little bit scary," Nolan shared. 

"I think recreating the Trinity test without the use of computer graphics, was a huge challenge to take on," Nolan previously told Total Film. "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." 

"It's a story of immense scope and scale," Nolan added. "And one of the most challenging projects I've ever taken on in terms of the scale of it, and in terms of encountering the breadth of Oppenheimer's story. There were big, logistical challenges, big practical challenges. But I had an extraordinary crew, and they really stepped up. It will be a while before we're finished. But certainly, as I watch the results come in, and as I'm putting the film together, I'm thrilled with what my team has been able to achieve."

Joining Murphy, Blunt, and Damon are Robert Downey Jr., Florence Pugh as Jean Tatlock, Benny Safdie as Edward Teller, Michael Angarano as Robert Serber, Josh Hartnett as Ernest Lawrence, Dylan Arnold as Frank Oppenheimer, David Krumholtz as Isidor Isaac Rabi, Matthew Modine as Vannevar Bush, Josh Peck as Kenneth Bainbridge, Devon Bostick as Seth Neddermeyer, Matthias Schweighöfer as Werner Heisenberg, Christopher Denham as Klaus Fuchs, Guy Burnet as George Eltenton, Danny Deferrari as Enrico Fermi, Emma Dumont as Jackie Oppenheimer, Gustaf Skarsgård as Hans Bethe, Trond Fausa Aurvåg as George Kistiakowsky, and Gary Oldman as Harry S. Truman.

Opening on July 21st, Oppenheimer is based on Kai Bird and Martin J. Sherwin's Pulitzer Prize-winning novel American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer.