April 1968: The film 2001: A Space Odyssey gets (some of) the science right

On April 2, 1968, the movie 2001: A Space Odyssey premiered at the Uptown Theater in Washington, D.C. Today, it is a science fiction classic, having inspired many subsequent films: George Lucas borrowed filmmaking techniques used in the movie for depicting outer space in his 1977 movie Star Wars. Christopher Nolan cites 2001 as an influence for his 2014 film Interstellar.

The movie defies summarization. The plot tells the story of different groups of Earthlings, at different points in spacetime, who independently find a large, opaque slab left by aliens. The movie’s first act focuses on a group of apes on early Earth. The second act follows an astronaut as he travels to a colony on the moon. The third and fourth acts follow two more astronauts, whose artificial intelligence system tries to kill them en route to Jupiter.

The characters scarcely speak to each other. The movie features a baffling 10-minute sequence of moving streaks of light, as well as scenes of extensive silence. The central mystery of the movie — what is the slab? — is never explained.

When it premiered, a critic at The New York Times called it “somewhere between hypnotic and immensely boring.” The first time I saw it, in a movie theater in 2018, I fell asleep twice.

But 2001 becomes transcendent upon further viewings.

In 1964, Stanley Kubrick, the movie’s director, met with the science fiction writer Arthur C. Clarke to begin a four-year collaboration on what would become 2001. Kubrick wanted to make “the proverbial ‘really good’ science fiction movie,” he wrote Clarke in an initial letter. In particular, he wanted it to explore the deeper philosophical meaning of space travel.

For that, Kubrick wanted the science to be correct. This wasn’t strictly necessary; a movie doesn’t need to be scientifically accurate to be compelling, and too much technical detail can bog down the story. Sometimes the aliens are tiny and green, and that’s that. Sometimes you want a spaceship that can travel faster than light, no questions asked.

But in 2001, Kubrick’s adherence to scientific accuracy is central to the film’s emotional power. The science grounds the movie. The characters may be living in disorienting, rotating reference frames, in a vast, unknowable universe, but they still have the same physical limitations as real humans.

To make the movie realistic, Kubrick not only partnered with Clarke, who was known for scientifically accurate fiction, but also solicited input from space scientists and other technical experts. Some experts worked directly on the production, which took place at MGM’s film studios north of London. Frederick Ordway III, a NASA space scientist whom Kubrick met through Clarke, served as a scientific advisor on the film.

Traveling from the U.S. to the U.K. in a pre-Internet, pre-flash drive era, Ordway packed “dozens of trunks full of drawings and technical data,” he wrote in 1970 in The Making of Kubrick’s 2001. He also coordinated the construction of designs ranging from the space pods to the characters’ outfits, some of them tailored for the weightlessness of space. Stewardesses on the space shuttle, for example, wear padded hats in case they hit the ceiling when their Velcro shoes lose traction with the floor. His expertise also informed the production team’s “model makers,” who built a scale model of the moon, as mapped by a rocket.

To design the spaceships in the film, Kubrick relied on Harry Lange, a German immigrant who was the head of NASA’s future projects section and a skilled draftsman and illustrator. Kubrick “was an absolute stickler for detail,” Lange told the BBC in 2002 about Kubrick. Working with Lange, Kubrick churned through many iterations of the film’s space station and ships. Not all of Kubrick’s ultimate design choices were scientific: one version of the Discovery One spaceship consisted of panels that dissipated heat from the ship’s nuclear reactor. Kubrick ultimately scrapped the panels because he thought that the viewers would confuse it for wings.

Kubrick also wanted to accurately depict artificial gravity in spaceships. To do this, he commissioned a British airplane company to build a huge centrifuge for $300,000 at the time. The centrifuge did not actually simulate gravity, as it could only spin about 3 miles per hour, and all the furniture and props had to be nailed down. But combined with camera tricks in the centrifuge, Kubrick creates a disorienting scene where an astronaut gets exercise by jogging along the cylindrical interior of a spinning spaceship.

At one point, Kubrick considered buying insurance to cover the possibility that humans might discover alien life before he finished the movie, as NASA had recently launched a probe for a flyby mission to Mars. If we met aliens in real life, his thinking went, no one would want to watch a movie about it. (Ultimately, he rejected the premium offered.)

The scientific accuracy also contributes to the movie’s continued relevance. HAL, the AI aboard the ship bound for Jupiter, responds to the astronauts in an easy, manipulative tone that evokes the sycophantic words of ChatGPT. The parallels may stem, in part, from Kubrick consulting Marvin Minsky, an AI researcher at MIT, to create HAL. At the time, researchers were developing neural networks that would ultimately become the backbone of the large language models behind ChatGPT.

In addition, when HAL starts malfunctioning, it calls to mind current anxieties over AI. HAL is supposedly incapable of error, but the astronauts are using HAL on a mission to Jupiter that no one has completed before. In our world, companies release AI after safety testing, but this testing cannot account for all the chaos of a real-world setting.

By getting the science (mostly) right, the film can explore Kubrick’s philosophical questions. The strange slab becomes a metaphor for questions that science cannot answer.

“I don’t like to talk about 2001 much because it’s essentially a nonverbal piece,” Kubrick once said. “I think clearly that there’s a basic problem with people who are not paying attention with their eyes. They’re listening. And they don’t get much from listening to this film. Those who won’t believe their eyes won’t be able to appreciate this film.”

The movie doesn’t have answers. It lays out what’s possible with science, and leaves the rest a mystery.