How Cillian Murphy Found His ‘Resting Physicist’s Face’

“My job is to convince the audience that Oppenheimer knows what he’s doing. I really spent most of the time working on his psychology.� Photo: Melinda Sue Gordon/Universal Pic/Melinda Sue Gordon

This article was originally published on July 28, 2023. At the 2024 Oscars, Cillian Murphy won the award for Best Actor for his performance in Oppenheimer.

“Cillian, I’m making a movie. It’s called Oppenheimer and I’d like you to play Oppenheimer.� With those words, Christopher Nolan introduced Cillian Murphy to the role that may wind up defining the Irish actor’s career. After having made five previous films with Nolan, Murphy now plays the lead in the atomic-age drama Oppenheimer. It’s a historical biopic turned on its head — the story of the brilliant man who created a doomsday weapon and spent much of the rest of his life stewing in regret and shame. The part requires so much of Murphy, because the character’s emotional journey happens less through dialogue exchanges and more through subtle changes on his face and the way he moves, through the intimate spectacle of a man torturing himself in his own mind. When I interviewed the cast and crew about the film, just about everybody was full of gushing praise for Murphy, and it’s easy to see why. He has certainly given some staggering performances in the past, but he is particularly riveting and moving in Oppenheimer. Back in June, before the SAG-AFTRA strike, we spoke about this life-changing part.

When did Christopher Nolan approach you about doing this film?
Out of the blue, in typical Chris fashion. He gave me no preparation. There was no preamble. He just called me in September of 2021, I think. And he said in his very understated, low-key manner, “Cillian, I’m making a movie. It’s called Oppenheimer and I’d like you to play Oppenheimer.�

How much did you know about J. Robert Oppenheimer at that point?
Honestly, not a lot. I knew vaguely about the Manhattan Project and I knew he was the father of the atomic bomb, as they say. But other than that, he was pretty sketchy, so I had to dive in straight away.

Did Nolan have any initial guidance that he gave you? After you said yes to the role, what were your initial conversations like?
Oh, they were long and manifold. He came to Dublin to meet me and I went over to Los Angeles many times during prep, and we talked and talked and talked. Obviously, I read the book American Prometheus as well, and then I dove into all the archival material that’s available. But I leaned on Chris a lot because we have known each other for so long and because I have such great admiration for him and trust in him.

With real-life characters, it seems there’s often a fine line between accuracy and impersonation. There are the needs of the script, and the historical record, but then I imagine there’s a certain amount of imagination and creativity that you have to bring to this character, in order to inhabit the role.
We were very clear from the beginning that it wasn’t an impression or impersonation. It was a synthesis of Chris’s script and all the stuff that I had in my head. Chris creates a really safe space or environment for actors to create and to contribute. Because of our history, I felt I could really bring things to him and try stuff out. As the cast list grew, these incredible actors who I admire immensely became attached to the project, and it got more and more exciting. But it was very much a relationship between myself and Chris in developing the character. I would call him and I would do the voice for him, or we would be in L.A. and we would figure out how the clothes fit. He would send me pictures of David Bowie.

Why David Bowie?
Well, it was the silhouette. Do you remember that Bowie period, like the Thin White Duke or maybe Young Americans, when he was so skinny and kind of emaciated but he had these wonderful tailored suits with the trousers? If you look at some of the costuming in the movie, you can see these wide balloon pants and these beautifully tailored suits. That was the Oppenheimer silhouette. Oppenheimer was incredibly physically frail, but just so intellectually robust and strong.

I am a very big fan of your performance in Dunkirk, particularly the physicality of it, because you don’t get a lot of lines; nobody gets a lot of lines in that movie. But the way you carry yourself at different points in that film says so much about the emotions of the character and the journey he’s on. When early on, he’s so in charge and calm, and then after he’s rescued by the boat, how he tries to assert himself, but he’s falling apart, he’s almost concave. 
I come from theater, and I love acting with my body. You get to do that an awful lot in theater, but you don’t get to do it as much in film because film is about the close-up generally. And theater is always by necessity in a wide shot.

The book was very useful for Oppenheimer — with firsthand accounts of how he carried himself, his kind of energy, how he smoked a cigarette. I lost a lot of weight. And then immediately, that does something to the way you walk, the way you hold yourself, the way clothes fall on you. So that was an unpleasant but useful exercise. Sometimes you can build a character from the outside in, or sometimes the sort of superficial appearance can help with the interior landscape. Because a lot of the movie is kind of his interior landscape.

Let’s talk about that. In the film, after Hiroshima and Nagasaki, Oppenheimer doesn’t really express regret or shame, but it’s clear that he feels them. So much of the film becomes about his face and his bearing, not so much the dialogue. As a performance, that seems like it’d be incredibly difficult.
For me, they’re the performances I’m always attracted to — almost inexpressible, kind of beyond language. They’re the richest ones.  And the film actors that I’ve always loved are the ones that if they think it, you can feel it. I guess that’s kind of what I tried to do with him. A scene that is a beautiful combination of what I was trying to do and what Chris does so brilliantly was that scene where he is trying to give the speech after Hiroshima and there’s all these kids in the bleachers, and he just can’t speak. He goes into this fugue state. That was us trying to communicate to the audience what he was actually struggling with in a nonverbal way.

That scene, the way it’s cut and sound-edited, is very similar to the Trinity scene. Everything’s quiet, all we hear is Oppenheimer’s breathing, and then there’s the blast of sound that comes in — in one case, the explosion, and in the other, the belated roar of the crowd. Was it that way in the script? Did you know it was going to be put together that way?
Oh, a hundred percent. Everything is stage-directed in the script, everything is there. In Chris’s films, the script is the film. It doesn’t get moved around or experimented with much in the edit. So yes, it was all there.

The film also gives us just enough of the science to make sure that we’re not lost, but not so much that we’re suddenly confused. That’s obviously the script, too. But, as the guy who has to be the guy who knows everything, or pretend to be the guy who knows everything, how did you approach that?
Well, I’ve actually played a physicist before in a movie for Danny Boyle years ago called Sunshine. So I must have resting physicist’s face. I did an awful lot of research there. What became clear to me really quickly was that there’s no point in me wasting time trying to understand quantum mechanics. I don’t have the intellectual capability to do that. You have to study your whole life and there’s only a tiny fraction of the population that can understand it. My job is to go after the humanity. I spoke to Kip Thorne, who is the Oppenheimer science adviser, and I have a vague conceptual grasp on what the physicists were experimenting on. But that’s not my job. My job is to convince the audience that Oppenheimer knows what he’s doing. I really spent most of the time working on his psychology.

Were there any specific notes that Chris gave you during production that were particularly helpful or insightful?
It was probably in our first week of shooting in Los Alamos, and I was doing a scene with Groves, Matt Damon. I think I came in pretty hard on the scene a couple of times. A little more aggressive than was necessary, because Oppenheimer would use his intellect rather than his physical presence in these situations. I remember Chris took me aside, and he said, “He’s not a boxer, he’s a chess player.� All of a sudden, the whole scene made complete sense. With a note that concise and brilliant, that’s why he’s such a magnificent director.

Damon’s Groves, Robert Downey Jr.’s Strauss, Emily Blunt’s Kitty — I feel like those are characters who serve as foils for Oppenheimer. Groves is so certain of who he is and where he stands on these issues. In a way, Strauss is too. And Kitty is the one who’s always telling Robert to fight. She’s frustrated that he’s not. Can you describe that dynamic with them?
Groves needed Oppenheimer and Oppenheimer needed Groves to become the man that he became. The relationship with Kitty is so dysfunctional. It shouldn’t work, yet it does. It sustains and they both need each other again. I suppose the most complex one is with Strauss. I remember talking with Downey and Chris about that, and we used the Amadeus dynamic between Salieri and Mozart; that Strauss wants to be the genius, but he will never be the genius, and he sees the true genius in someone else, so he feels compelled to derail it.

In an interview with Downey — and I don’t know how tongue-in-cheek he was being — he said, “Well, Strauss is really the hero of the movie.� That’s a great thing to hear from an actor because they have to believe that to a certain extent to perform the part. 
I don’t think there’s anyone in this movie that’s a clear-cut antagonist. I don’t think Downey fulfills that. It’s far more complex. I love the fact that he feels slighted at one point, and that is enough for him to take down an individual. History can turn on one man feeling slighted by another.

Donald Trump probably doesn’t run for president if Barack Obama doesn’t make fun of him at the White House Correspondents’ Dinner …
I love that. That’s a great analogy. I think history is littered with that, with vanity and narcissism.

The film takes place over quite a long period of time, and there are flashes to Oppenheimer’s youth as a student. What did you have to do to embody him as a young man in his 20s, and then as a much older man?
That was a lot of testing hair and makeup stuff. We all know that Chris doesn’t use CGI, so we had an amazing hair and makeup team, and we worked a lot on that. It was all done really through me and hair and makeup. That was it.

So much of the film happens in close-up, and so much of the film is shot in Imax. I know Imax cameras are huge and loud. I imagine it’s different than just having an ordinary camera in your face?
It’s vastly different, but I’ve worked with Chris on a number of projects that he shot on Imax, so I’m kind of used to it. The thing about Chris’s films, despite the format that he’s using, it does feel like a small independent movie because on set it’s just Chris, the focus-puller, the boom operator, and the actors. There’s no monitors. He’s not away in a tent somewhere. He’s right there beside you. So it feels very intimate. I should pay tribute to Hoyte van Hoytema, our DP, who’s phenomenally talented and also a kind, calm, gentle presence on the floor.

One thing editor Jennifer Lame told me was that Chris was obsessed with images of droplets and ripples and things like that while shooting and editing the film. Was that something you talked about?
Chris has always been kind of haunted with this stuff. And he has incredible luck with weather. We needed it to rain specifically in that scene between Einstein and Oppenheimer, for the ripples and the droplets. And it rained! It was otherwise a beautiful blue-sky day, and then all of a sudden it rained exactly when it needed to. Similarly, when the storm kicks up before the Trinity test. An actual storm kicked up when I’m climbing up the tower.

What do you recall about shooting the film’s final scene with Einstein?
We shot that in one day. I remember it was me and Tom Conti and Downey. We shot that all in a day or two in Princeton. We shot in Oppenheimer’s office and in Einstein’s office, and then we went out onto the green and down to the pond. So it was all a real location. I absolutely think the ending of this film is extraordinary. I remember reading the script going, “Wow, that’s one of the greatest endings.� And I think it’s where many, many feature films fail is in the third act.