Speaking with Vulture, the actress discussed the secrecy surrounding the film, and admitted that sometimes even she didn't understand some of the scientific concepts Nolan wanted her character to master.
When asked how much of the movie's plot the trailer covered, Chastain told the site, "I can't say ANYTHING," adding, "Everyone knows pretty much who I'm playing," without confirming or denying her character's identity. (She's widely suspected to be portraying the now-grown daughter of space traveler Matthew McConaughey.) Of the mystery shrouding the film, Chastain said she wanted to do her part to follow Nolan's spoiler-free example.
"Christopher Nolan is the kind of person you NEVER want to disappoint," she told Vulture. "Not because he's mean, but just because, you know, if your dad ever said to you, 'I'm really disappointed in you,' you'd go, 'Oh my God!' That kind of thing. If he ever said, 'I'm really disappointed,' you'd be like, [pretends to sob] 'I've ruined everything!'"
What Chastain would reveal, however, centered around the film's exploration of the space-time continuum, and how Nolan's knowledge of the subject intimidated her. A special on-set consultant also helped set up some of the film's subject matter, she said.
"I'm playing a character where I should know certain things, so I tried to do what I could," Chastain said of learning more about the space-time continuum. "I mean, your brain either works a certain way or it doesn't. My brain is more like an artist's brain, not a science brain. But I had conversations with [theoretical physicist] Kip Thorne, which were really cool. He's one of the most famous physicists. I don't know if I'm allowed to say this, but he works in a certain types of space studies."
And as for "Interstellar"'s ultimate message, the actress indicated that it would mean different things to different people.
"To me it's a beautiful film because it's a metaphor, too," Chastain said. "There's more than just outer space. It's very emotional."
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