As Clark noted, there have been cases of humans surviving the vacuum. In the mid-sixties a NASA test subject in a chamber was exposed. He remembers his tongue starting to boil and Clark explained others have said they felt grittiness on their eyes, "basically bubbles forming." That's ebullism. Ultimately, though, you probably don't suffer very much, Clark said: "Every time you take a breath you are getting rid of oxygen. Then you just go out. You're just unconscious and then your brain starves and it dies and then your heart stops, but you don't suffer. It's pretty quick." On the other hand, if you're in a space suit that runs out of oxygen, carbon dioxide could become a problem—a problem which is in fact on display in the film. "If you’re in a suit though and you run out of oxygen the only downside to that is you could end up building up carbon dioxide and that could make you very anxious and air hungry," Clark explained. In the film, Sandra Bullock's panicked heavy breathing makes this situation feel all too real.

It's no spoiler to say that her character faces the discomfort of dying in her suit during her fight for survival. In doing so she spins out of control, the camera taking on her perspective in nauseating fashion. Clark said, "you're basically like a hockey puck, you're just going wherever the forces of mass and acceleration take you," though he did add that you can act like a "skater" and use your arms to lessen your spin. A NASA representative told us that likely wouldn't happen in a real life situation: their spacesuits are affixed with a SAFER backpack, a jet pack, that allows astronauts to control themselves. While Bullock's character does spin out of control at one point in the film, it's one of the errors Jeffrey Kluger of Time pointed out in his "fact check" of the film. That isn't the only not quite realistic part of Gravity — Dennis Overbye at the New York Times points out a major plot hole in the film, having to do with the differing orbits of the Hubble Telescope and the International Space Station — but its general sense of, uh, spaciness apparently ring true. It's hard to argue with a rave review from Buzz Aldrin in The Hollywood Reporter. "We're in a very precarious position of losing all the advancements we've made in space that we did 40 years ago, 50 years ago, " he wrote. "From my perspective, this movie couldn't have come at a better time to really stimulate the public." Stimulate it may—it also forces you to contemplate your place in the vastness and loneliness of space.

This article is from the archive of our partner The Wire.