Clarke was the authority on both the science and the science fiction, but an account he gave later provides a sense of what working with Kubrick was like: “We decided on a compromise—Stanley’s.” The world of “2001” was designed ex nihilo, and among the first details to be worked out was the look of emptiness itself. Kubrick had seen a Canadian educational film titled “Universe,” which rendered outer space by suspending inks and paints in vats of paint thinner and filming them with bright lighting at high frame rates. Slowed down to normal speed, the oozing shades and textures looked like galaxies and nebulae. Spacecraft were designed with the expert help of Harry Lange and Frederick Ordway, who ran a prominent space consultancy. A senior NASA official called Kubrick’s studio outside London “NASA East.” Model makers, architects, boatbuilders, furniture designers, sculptors, and painters were brought to the studio, while companies manufactured the film’s spacesuits, helmets, and instrument panels. The lines between film and reality were blurred. The Apollo 8 crew took in the film’s fictional space flight at a screening not long before their actual journey. NASA’s Web site has a list of all the details that “2001” got right, from flat-screen displays and in-flight entertainment to jogging astronauts. In the coming decades, conspiracy theorists would allege that Kubrick had helped the government fake the Apollo 11 moon landing.

Kubrick brought to his vision of the future the studiousness you would expect from a history film. “2001” is, in part, a fastidious period piece about a period that had yet to happen. Kubrick had seen exhibits at the 1964 World’s Fair, and pored over a magazine article titled “Home of the Future.” The lead production designer on the film, Tony Masters, noticed that the world of “2001” eventually became a distinct time and place, with the kind of coherent aesthetic that would merit a sweeping historical label, like “Georgian” or “Victorian.” “We designed a way to live,” he recalled, “down to the last knife and fork.” (The Arne Jacobsen flatware, designed in 1957, was made famous by its use in the film, and is still in production.) By rendering a not-too-distant future, Kubrick set himself up for a test: thirty-three years later, his audiences would still be around to grade his predictions. Part of his genius was that he understood how to rig the results. Many elements from his set designs were contributions from major brands—Whirlpool, Macy’s, DuPont, Parker Pens, Nikon—which quickly cashed in on their big-screen exposure. If 2001 the year looked like “2001” the movie, it was partly because the film’s imaginary design trends were made real.

Much of the film’s luxe vision of space travel was overambitious. In 1998, ahead of the launch of the International Space Station, the Times reported that the habitation module was “far cruder than the most pessimistic prognosticator could have imagined in 1968.” But the film’s look was a big hit on Earth. Olivier Mourgue’s red upholstered Djinn chairs, used on the “2001” set, became a design icon, and the high-end lofts and hotel lobbies of the year 2001 bent distinctly toward the aesthetic of Kubrick’s imagined space station.

Audiences who came to “2001” expecting a sci-fi movie got, instead, an essay on time. The plot was simple and stark. A black monolith, shaped like a domino, appears at the moment in prehistory when human ancestors discover how to use tools, and another is later found, in the year 2001, just below the lunar surface, where it reflects signals toward Jupiter’s moons. At the film’s conclusion, a monolith looms again, when the ship’s sole survivor, Dave Bowman, witnesses the eclipse of human intelligence by a vague new order of being. “2001” is therefore only partly set in 2001: as exacting as Kubrick was about imagining that moment, he swept it away in a larger survey of time, wedging his astronauts between the apelike anthropoids that populate the first section of the film, “The Dawn of Man,” and the fetal Star Child betokening the new race at its close. A mixture of plausibility and poetry, “real” science and primal symbolism, was therefore required. For “The Dawn of Man,” shot last, a team travelled to Namibia to gather stills of the desert. Back in England, a massive camera system was built to project these shots onto screens, transforming the set into an African landscape. Actors, dancers, and mimes were hired to wear meticulously constructed ape suits, wild animals were housed at the Southampton Zoo, and a dead horse was painted to look like a zebra.

For the final section of the film, “Jupiter and Beyond the Infinite,” Ordway, the film’s scientific consultant, read up on a doctoral thesis on psychedelics advised by Timothy Leary. Theology students had taken psilocybin, then attended a service at Boston University’s Marsh Chapel to see if they’d be hit with religious revelations. They dutifully reported their findings: most of the participants had indeed touched God. Such wide-ranging research was characteristic of Clarke and Kubrick’s approach, although the two men, both self-professed squares, might have saved time had they been willing to try hallucinogens themselves.

The Jupiter scenes—filled with what Michael Benson describes as “abstract, nonrepresentational, space-time astonishments”—were the product of years of trial and error spent adapting existing equipment and technologies, such as the “slit-scan” photography that finally made the famous Star Gate sequence possible. Typically used for panoramic shots of cityscapes, the technique, in the hands of Kubrick’s special-effects team, was modified to produce a psychedelic rush of color and light. Riding in Dave’s pod is like travelling through a birth canal in which someone has thrown a rave. Like the films of the late nineteenth century, “2001” manifested its invented worlds by first inventing the methods needed to construct them.

Yet some of the most striking effects in the film are its simplest. In a movie about extraterrestrial life, Kubrick faced a crucial predicament: what would the aliens look like? Cold War-era sci-fi offered a dispiriting menu of extraterrestrial avatars: supersonic birds, scaly monsters, gelatinous blobs. In their earliest meetings in New York, Clarke and Kubrick, along with Christiane, sketched drafts and consulted the Surrealist paintings of Max Ernst. For a time, Christiane was modelling clay aliens in her studio. These gargoyle-like creatures were rejected, and “ended up dotted around the garden,” according to Kubrick’s daughter Katharina. Alberto Giacometti’s sculptures of thinned and elongated humans, resembling shadows at sundown, were briefly an inspiration. In the end, Kubrick decided that “you cannot imagine the unimaginable” and, after trying more ornate designs, settled on the monolith. Its eerily neutral and silent appearance at the crossroads of human evolution evokes the same wonder for members of the audience as it does for characters in the film. Kubrick realized that, if he was going to make a film about human fear and awe, the viewer had to feel those emotions as well.

And then there is HAL, the rogue computer whose affectless red eye reflects back what it sees while, behind it, his mind whirrs with dark and secret designs. I.B.M. consulted on the plans for HAL, but the idea to use the company’s logo fell through after Kubrick described him in a letter as “a psychotic computer.” Any discussion of Kubrick’s scientific prescience has to include HAL, whose suave, slightly effeminate voice suggests a bruised heart beating under his circuitry. In the past fifty years, our talking machines have continued to evolve, but none of them have become as authentically malicious as HAL. My grandfather’s early-eighties Chrysler, borrowing the voice from Speak & Spell, would intone, “A door is ajar,” whenever you got in. It sounded like a logical fallacy, but it seemed pleasantly futuristic nonetheless. Soon voice-command technology reached the public, ushering in our current era of unreliable computer interlocutors given to unforced errors: half-comical, half-pitiful simpletons, whose fate in life is to be taunted by eleven-year-olds. Despite the reports of cackling Amazon Alexas, there has, so far, been fairly little to worry about where our talking devices are concerned. The unbearable pathos of HAL’s disconnection scene, one of the most mournful death scenes ever filmed, suggests that when we do end up with humanlike computers, we’re going to have some wild ethical dilemmas on our hands. HAL is a child, around nine years old, as he tells Dave at the moment he senses he’s finished. He’s precocious, indulged, needy, and vulnerable; more human than his human overseers, with their stilted, near robotic delivery. The dying HAL, singing “Daisy,” the tune his teacher taught him, is a sentimental trope out of Victorian fiction, more Little Nell than little green man.