The Etymology of Unobtanium

The much-mocked wonder-rock from the 2009 blockbuster ‘Avatar’ doesn’t have an atomic number, but engineers have used the actual word for decades

Floating unobtanium from the movie Avatar
The vaunted unobtanium from Avatar. Twentieth Century Fox via Avatar Wiki

The debut of the long-awaited sci-fi sequel Avatar: The Way of Water in movie theaters last weekend is news not just because it’s a follow-up to the highest-grossing film in history, but because it comes from writer-director James Cameron—a one-of-a-kind hybrid of fantasist and oceanographer. Though his film career began in earnest with 1984’s low-budget classic The Terminator, his movies have in more recent decades become famed for their technical innovation and massive expense. And whether they’re set primarily in the past (like 1997’s Academy Award-winning romance Titanic), the present (like 1989’s The Abyss) or the future (like 2009’s Avatar and its new follow-up), Cameron’s movies use pioneering technology to tell stories that share a deep skepticism about humankind’s ability to wield technology responsibly.

Avatar embodied this contradiction more literally than any Cameron production before. It’s about a mid-22nd-century experiment that allows human astrobiologists to inhabit other bodies—specifically, cloned versions of the 10-foot-tall, blue-skinned vessels of an intelligent species native to the exoplanet Pandora. Pandora is also the source of a metal so precious that the film’s “Resources Development Administration” has set up a permanent settlement on the planet, even though it’s an extremely hostile environment some six years’ spaceflight from Earth, to mine it.

Those who embraced Cameron’s ecological fable—wherein the colonizing, pillaging humans are (with a few exceptions) the villains, and the blue-skinned Na’vi, who revere and live in harmony with the flora and fauna of their home world, are the heroes—were obviously willing to suspend their disbelief to accept any number of imaginary elements. Ironically, the one that proved a bridge too far for some was the one Cameron did not invent: The name of the rare metal that served as the film’s MacGuffin.


“This pays for the whole party,” a villain portrayed by Giovanni Ribisi says in the 2009 film, contemplating a golf-ball-sized sample of the stuff floating in a little magnetic field on his desk. The silly-sounding name of the material provided a ready punchline at the time, and even 13 years later, some still haven’t figured out unobtanium is a real thing. Not an actual, corporeal substance like copper or tin or sour grapes, but a concept in engineering dating back at least as far as the 1950s.

James R. Hansen’s space history Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917-1958 documents the term’s usage in an October 1957 meeting lamenting “the lack of a superior high-temperature material (which the Langley structures people dubbed ‘unobtanium’).” The word became a sort of placeholder for an unknown material that would have the properties designers required of it, like plugging X into an equation.

“It’s not new to invent a new force of nature or a new element for a science-fiction story,” says Matthew Shindell, the National Air and Space Museum’s curator of planetary science and exploration. He cites Percy Greg’s seminal 1880 novel Across the Zodiac, which posited that space travel might be made possible through the generation of a type of anti-gravitational energy that Greg dubbed “apergy.” That word, insofar as I can tell, did not catch on. But Greg also named his imaginary spacecraft the Astronaut. It’s the earliest recorded usage of that word to refer to someone who travels in space.

In Greg’s case, a fictional word made its way into the lexicon of real science. In Cameron’s, or at least in the case of unobtanium, that calculus was inverted.

“In [Avatar], what’s interesting is that the unobtanium is what makes travel to that planet affordable,” Shindell says. “That actually rings kind of true to discussions about mining asteroids or even mining the moon. In order to make it feasible, you’d have to find some substance that was incredibly valuable”

That idea is captured in a second, related-but-slightly different usage of unobtanium: to describe a substance that actually does exist but is “so expensive or so limited in the quantities we could get that it might as well not,” Shindell elaborates.

Avatar was not even the first sci-fi movie to exploit unobtanium’s vast potential to make audiences chuckle. The journey-to-the-center-of-the-Earth adventure The Core featured it six years prior. The Core adopts unobtanium as the winking name of a substance used to build a drill to tunnel to the center of the Earth. (“Its real name has 37 syllables,” explains a scientist played by Delroy Lindo.)

It doesn’t seem like too great a leap to assume that Cameron, who also designs submarines and invents new types of cameras—and who, a little more than two years after Avatar hit theaters, became the first person in history to complete a solo dive to the deepest point in the ocean—would have stumbled across the term in a non-imaginary context.

A Toronto National Post story by Chris Vander Doelen about automotive designers published on June 9, 2006—or three-and-a-half years pre-Avatar, if we’re still keeping track—provided a neat definition of unobtanium courtesy of Pat Schiavone, then-director of car design for Ford North America. Schiavone told the reporter that unobtanium is a material that “virtually has no cost” and can assume any shape a design team can imagine. To be fair, the story is largely about the insular and silly-sounding vocabulary of designers. “Consumers,” Vander Doelen writes, “would be mystified by the secret slang used by automotive designers, the most mysterious—some say unhinged—people in the biz.”

While car designers can afford to speak in a secret dialect, blockbuster filmmakers must appeal to the broadest audiences possible to justify their films’ price tags. And whatever real-world properties 20th-century aeronautical engineers, 21st-century car designers or 22nd-century robber barons may imagine unobtanium to have, the linguistic of the word itself are somehow appealing to them all.

“It’s a word that’s very expressive of what it’s meant to be,” Shindell says.

Alas, in the sequel, Cameron and his four credited co-writers have deployed zero utterances of “unobtanium” in its superconducting 192-minute run time. Maybe Cameron was tired of hearing about it.

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