Zero Gravity, Too Many Blunders

“Life in space is impossible.” There is no gravity, no sound, no air pressure, and no oxygen. Director Alfonso Cuarón opens the film, Gravity, with these facts about space on a black backdrop, accompanied by unnerving silence. When astrophysicist Neil deGrasse Tyson’s tweets dissected several inaccuracies in the film, many reviewers lashed back, arguing that the film is a science-fiction film and not a documentary: it makes no pretenses to scientific accuracy. But it does. I am neither an astrophysicist nor an astronaut—merely a chemistry major—but even I noticed a few key blunders in a film that painstakingly tries to be as scientifically accurate as possible. Little wonder science-minded viewers interpret every fact to be a taunt. Gravity throws down the gauntlet and dares us to find something wrong with it. Challenge accepted.

The film gets off to a respectable start. Visually Gravity is absolutely stunning. It portrays Dr. Ryan Stone (Sandra Bullock) and Matt Kowalski (George Clooney) in space and zero gravity with the right lighting and with computer-generated imagery, puppeteers, wire suspension systems, and new cinematography tools like “The Light Box.” Although Dr. Stone and Kowalski are essentially the only two characters in the film, Bullock’s emotional performance along with Clooney’s calm and collected, joking personality are more than enough to keep the viewers engaged for ninety minutes. For a movie with a simplistic plot: two astronauts in space try to make it back to Earth after a catastrophe caused by space debris, it may be surprising how Gravity became such a Blockbuster success. The success of the film can almost be purely attributed to the breathtaking cinematography. Cuarón’s opening 13-minute shot epitomizes the entire movie. In this shot, we slowly zoom into a team on a spacewalk to service the Hubble Telescope when suddenly a storm of space debris separates Dr. Stone from Kowalski. The one shot effortlessly captures the tranquility of space and the wondrous feeling of weightlessness with masterful sound design and camerawork. The free-floating nature of the camera and the absence of noise simulate the environment of space perfectly for the viewer. While the shot begins with a serene, panoramic view of space, it ends with the juxtaposition of the claustrophobic, terrifying nature of being trapped in a space suit and the eerie, vastness of space as Dr. Stone tumbles to infinity and beyond. Space is peaceful and lonely, limitless and suffocating, and beautiful and ominous. In just one shot, Cuarón is able to skillfully depict space in all its glory.

For a film so obsessed with detail and accurately portraying zero gravity, it is nerve-racking that the concept of weightlessness is clearly forgotten in one of the movie’s critical scenes. As Stone and Kowalski crash into the International Space Station (ISS), Stone’s leg gets tangled in parachute chords tethering her to the ISS. Meanwhile, she holds on to Kowalski by a strap on his space suit. Kowalski chooses to detach himself from Stone to save her, because he notices that his weight is pulling both of them away from the station. Since there is no gravity (basic physics: Forceweight­= mass*gravity) Kowalski is weightless; based on Newton’s laws, Kowalski could just pull on the strap, float toward Stone, and easily save himself. A potential counterargument for this weightlessness claim is that the Law of Conservation of Momentum applies in this situation, which could explain the downward force experienced by Kowalski.

Another critical inaccuracy of the film: the fire that starts in the ISS, which leads to the subsequent explosion. On Earth, fires consume oxygen and continue to burn due to the stack effect. Essentially, gravity allows hot, smoky air to rise, while cold air with fresh oxygen flows into the fire to sustain it. In zero gravity, the stack effect does not apply and a fire would smother itself with its own hot smoke and not receive a sufficient amount of oxygen to continue burning. Moreover, compartmentalization of segments of the ISS should definitely have prevented a massive fire from erupting because of how quickly the oxygen fuel would be consumed. While a chemical or electrical fire may be a bit more problematic, the highly flame-retardant material of the ISS should still be able to contain the flame.

Perhaps we can forgive Cuarón for some of the science blunders, since I doubt the narrative would have been as moving without them. In Gravity’s most heart-wrenching scene, Stone finally gets away from the exploding ISS in the Soyuz module only to realize that there is no fuel left. We empathize with her desperation and fear as she faces slow, impending death. Cuarón then paints one of the best shots in the film, capturing Stone’s floating, glimmering tears which visually echo the glistening stars in the background. While these tears capture the raw human emotion of the moment, and suggest how miniscule we are relative to the heavens above, Cuarón’s picturesque shot is completely inaccurate. In space, tears cannot fall down your face and float away. Instead, when you cry in space, tears simply collect on your face and aggregate into bigger and bigger pools of water. Adhesive forces of water allow tears to stick to the skin and not fall, while cohesive forces cause tears to accumulate into a pool. As Canadian astronaut Chris Hadfield demonstrates, tears in space appear more absurd than mystical (

Gravity’s other minor inaccuracies include the highly unrealistic odds of Stone surviving the storm of space debris twice, the ISS explosion, and re-entry into the atmosphere with the falling debris of the Chinese space station. Using a fire extinguisher as a propellant in space does obey the basic laws of physics, but it is ludicrous to assume that anyone could have much control and be able to navigate using it. And I can’t end without mentioning that the Hubble Telescope and the ISS are in completely different orbits and have different inclinations. It would be impossible to travel from one to the other using a jetpack or Manned Maneuvering Unit (MMU), which can usually only travel for a maximum of 1 km.

To be fair, Cuarón has stated that he was fully aware of this fact and that the screenplay’s original draft provided a scientific explanation for how the Hubble Telescope, ISS, and Chinese space station were all on the same plane. Evidently, these factual details were removed so the science would not detract from the narrative appeal of the film. In the case of these minor inaccuracies, it seems justifiable for Cuarón to sacrifice factual details for fiction. The primary objective of this film is to entertain audiences with a simulation of what space would be like, not put them to sleep with facts.

Gravity does get a lot right: the quiet nature of space, the feeling of weightlessness, the framework of the ISS, the muscular atrophy in space. It is precisely because of its general scientific accuracy that the problems stand out all the more. As a work of great cinematography, Gravity is a masterpiece, and one I hope will inspire a new generation to fall in love all over again with space exploration. As a work of science, however, it tries hard but ultimately doesn’t make the grade.

Overall Grade: A-

Physics Grade: B

Zinan Zhang is a senior in the Chemistry Department.