Tall and willowy in a summery off-white ensemble, Rachel Weisz allows that she has a certain ignorance of science and astronomy.
"I'm so bad at math - I had a lot of cramming to do," Weisz says. "Do you say 'cramming' in America? But this was way outside my comfort zone. Let me just say that nothing about science has trailed back to my everyday life."
Weisz needed the tutoring to play the real-life astronomer and mathematician Hypatia, who lived in Roman Egypt about 400 years after Christ. In her new film, Agora, which opened in limited release last week, she is part of a story that hypothesizes that Hypatia, who had translated the work of Ptolemy, could have conceptualized the Sun as the center of the universe, rather than Earth, perhaps a millennium before Copernicus and Galileo. As the film shows, that notion didn't go over any better in Hypatia's day than in Galileo's.
"Oh, they thought it was heresy," Weisz says. "What's remarkable is that everything she was doing was imaginary because she was working in the time before the telescope. Everything she was figuring out, she was doing with her imagination. There was some math to back it up - but what she did was imagine things. Which is what I do for a living as well."
Agora, a film by Alejandro Amenabar (The Sea Inside), captures a moment of upheaval in Hypatia's world, in which the ruling-class pagans' multiple gods are mocked and attacked by Christians, who are also subject to strife with the Jews. Even as Hypatia uncovers her own mathematic hypothesis about the heliocentric universe, the balance of power is shifting away from the world Hypatia knows.
The themes of religious intolerance and religious extremism were "why I wanted to do this," Weisz, 40, says. "When I first read it, it was clear to me that it was a contemporary story set in the Fourth Century. We go for more of an anti-biography, because it seems so contemporary. I mean, even with things like stem-cell research and other ways we've evolved, there are still places in the world where women are not allowed to be educated.
"People still kill in the name of religion. We haven't evolved to the point where we're one tribe called humans. And that's an important message. In that sense, the pagans of this era were actually pretty enlightened. They didn't have fundamentalism. On the other hand, they had slavery, which was a giant blind spot."
The British-born Weisz, who lives in Brooklyn with director Darren Aronofsky and their young son, has moved easily between independent films like Agora, where she got her start, to studio films such as Fred Claus and The Lovely Bones. She won an Oscar for best supporting actress for 2005's The Constant Gardener.
"That was an incredibly surreal moment," Weisz says. "I became very British. One wants to be present, to be in the moment but I would defy anyone. It's like an out-of-body experience - and the odd thing is having it happen to you. It's the kind of thing that happens to other people. And as a result, you get more interesting directors offering more interesting scripts."
Since 2008, she's been in The Lovely Bones, Agora, The Brothers Bloom and Definitely, Maybe - and has two more films (Dream House and The Whistleblower) awaiting release this year and next.
"I work in both worlds," she says. "I just did Dream House, a studio film for Jim Sheridan with Daniel Craig. And then I did a very low-budget independent film with a first-time Canadian director, The Whistleblower.
"When I first had my baby, I just wanted to do romantic comedies. My brain went soft, I think. I only wanted to do light things. But now I hope that, if anything, I'm more fearless. Having given birth - what could be scary after that?"