'Oppenheimer': Emily Blunt got 'withering' looks from Christopher Nolan for wearing Uggs

NEW YORK – Like most savvy actors, Matt Damon always picks up the phone for Christopher Nolan.

The A-lister, who previously appeared in Nolan’s 2014 film “Interstellar,” was planning to take a break from acting when the Oscar-nominated director called about “Oppenheimer” (in theaters Friday), his chilling new historical drama.

“I had told my wife I was taking time off,” says Damon, speaking to USA TODAY in a joint interview with co-star Emily Blunt before the Screen Actors Guild strike. “This was something we literally negotiated, but the one caveat was ‘if Chris Nolan calls.’ He was my get-back-to-work card, and then he actually called, which was a wonderful surprise.”

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Matt Damon brings levity to the 'wildly unpopular' Leslie Groves

In the white-knuckle epic, Damon plays gruff U.S. Army officer Leslie Groves, who calls on physicist J. Robert Oppenheimer (Cillian Murphy) to oversee the creation of the atomic bomb during World War II. Groves was “wildly unpopular” with the scientists, Damon says, and frequently butted heads with Oppenheimer. But there was still “mutual respect” between the two men.

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“They’re complete polar opposites,” says Damon, sitting at a hotel in New York's Tribeca neighborhood. “The military is obsessed with secrecy, and the scientists are trying to get to the root of the problem, which they do by sharing. Groves constantly felt like a kindergarten teacher chasing these guys around. So Chris found some comedy there, which is good for a movie about something so serious.”

“Maybe that’s why he cast you,” Blunt suggests. “Everyone loves you and you have a natural warmth. If you cast someone unlikable playing someone unlikable, it would’ve been (alienating).”

Emily Blunt's Kitty Oppenheimer is 'volatile' yet fiercely loyal

Blunt portrays Kitty, Oppenheimer’s caustic, alcoholic wife. When Oppenheimer is probed by government officials about possible Communist ties, she demands that he stop feeling sorry for himself. She’s similarly unsympathetic about the death of his former lover.

“Kitty didn’t do small talk. She only did big talk,” Blunt says. “There’s a lot about her that wouldn’t necessarily be ‘likable,’ but I don’t think she cared. She was such a force of personality.” Toward the end of the film, “she’s become so volatile and unpredictable – the drinking is out of control. But he says to his defense (team), ‘Kitty and I have walked through fire together, and I believe in her.’ She’ll fight for him when he won’t fight for himself.”

The movie's Trinity test scene was 'beautiful' yet 'nightmarish' to behold

One of the movie’s most thrilling sequences is the Trinity test, when the first nuclear weapon was detonated in the New Mexico desert in 1945. The bomb’s mushroom cloud and blinding light were recreated using practical effects.

“Because the explosion is real, it’s as beautiful as it is nightmarish,” Blunt says. “Because you know it’s not (computer-generated), you can’t dissociate from it.”

“You can’t take your eyes off it, but it’s the most terrible thing you’ve ever seen,” Damon adds. Witnessing it on the set, “it was a big boom. Everybody had their earplugs in.”  

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Emily Blunt recalls her 'Devil Wears Prada' moment with director Christopher Nolan

“Oppenheimer” is the second film Blunt, 40, and Damon, 52, have made together, including the 2011 sci-fi thriller “The Adjustment Bureau.” Blunt says they would “hang out constantly” while shooting the latter, going on double dates with her husband, John Krasinski, and Damon’s wife, Luciana Barroso.

“Now we’re vacation buddies and neighbors,” says Blunt, who lives in the same Brooklyn apartment building as Damon. “I know, it’s ridiculous. This is strange not to see Matt in his sweats and slippers.”

“The only time I wear shoes is when we do interviews together,” Damon quips. “I’ve got a great pair of house slippers, and I’m going to put them right on when I get home. I did accidentally wear my Ugg slippers on a school run once.”

“Do you know who hates Uggs more than anyone?” Blunt asks. “Christopher Nolan. I’ve never known anyone to detest a pair of Uggs more than Chris Nolan. It’s a testament to how he wants everything on set to look as it would (in the period). If there’s a plastic bottle in the shot, he’s like, ‘Ugh!’ He hates to even look at it. I would sometimes put on some Uggs and I’d just get this withering look down to my feet – it was like being in ‘The Devil Wears Prada’ again. Just the look down to the shoes. And I'd go, 'I know, I know. But I'm just sitting on an apple box in the background today!' "

As a joke, Blunt gave Nolan a pair of Uggs at the end of the shoot. His wife, Emma Thomas, “wrote to me and was like, ‘Brilliant wrap gift. He’s wearing them now,’ " Blunt recalls with a laugh. “I was so pleased!”