For much of the past decade, the world hasn’t been looking for the half step. We’ve been dazzled by visions of the giant leap. A few years ago, reports surfaced that Intellectual Ventures, the invention factory run by Nathan Myhrvold, a former Microsoft chief technology officer, was developing a Harry Potter–ish invisibility cloak. The idea has become so overpromised that physicsworld.com, a sort of Huffington Post for physicists, recently reported the theft of the world’s first flexible invisibility cloak. This set the scientific world buzzing—Did the cloak finally exist?—until the physicsworld editors revealed it was an April Fool’s joke.
That’s not to say the cloak is impossible. Two technologies have shown potential. One concept uses digital video to capture the back-side environment and project it onto front-side material. In 2003, a team of Japanese scientists developed a poncho that sort of worked. Its inventors made a video and took some photos that you can find on the Web. But it’s been nearly a decade, and the world still awaits version 2.0.
The other technology that shows promise involves so-called metamaterials, fabrics engineered at the nano level to interact with light to produce what’s known as a negative index of refraction. Refraction occurs when a wave—a microwave, a light wave—changes speed. Think of how a drinking straw in a water glass appears to bend at the surface. That’s refraction, produced as light moves from air to water. If scientists can figure out how to manipulate this action and bend light around an object (imagine a stream of water moving around a rock), they might be able to make the object appear to disappear. Or so the theory goes.
Late last year, Cramer told me about a project he’d been working on for two years that sounded like it relied on refraction. He called it “quantum stealth,” and it seemed like science fiction. “It works by bending light around an object,” he explained at the time. “So far, we’ve been able to make an object about the size of an orange completely disappear.” When he said this, I nodded and nearly choked on my skepticism. If Cramer spoke the truth, he’d have surpassed the preeminent experts in the study of light refraction.
In 2006, the Duke University engineering professors David Smith and David Shurig, working with the British physicist John Pendry, developed a method to bend microwaves. Three years ago, professor Xiang Zhang and a team at UC Berkeley managed to bend infrared waves. But nobody had yet figured out how to bend waves of visible light. I figured Guy Cramer was blowing smoke.
Months passed. Then, this spring, Cramer invited me to his workshop. When I entered, he lowered the shades. Then he pulled up his iPad and showed me a video that depicted a cream-colored wall with a dark baseboard. In front of the wall stood something resembling a Japanese shoji screen, with panes as clear as Saran Wrap: I could see the wall behind it. In the video, a woman entered the room and walked behind the screen so that her head stuck out above it. And then I watched as her body disappeared. Her head floated above the screen, and I could see the wall. But nothing of her body. “We’re bending the entire spectrum of light—infrared, ultraviolet, thermal,” Cramer told me. “People are disappearing. It doesn’t use cameras or mirrors or require power.”
I didn’t know what to make of what I had seen (and Cramer wasn’t explaining). In his work, he maintains a constant tension between concealment and revelation. His video was tantalizing proof of nothing. A kid could achieve the same effect with video-editing software. The notorious optical-camouflage poncho had seemed mind-altering when it was caught on tape too. But nothing came of it. Could Cramer have really taken such a huge leap into the realm of the invisible?
Amy Coyne thinks maybe. Coyne is vice president for program management at ADS, a Virginia-based military-equipment contractor that helps bring Cramer’s ideas to market (ADS connected the Afghans with Cramer when new army camo was needed). “We have confidence in the quantum-stealth technology,” she said. “When you think of its potential, it’s staggering.”
Whether the mysterious technology makes it out of the lab is still anybody’s guess. Scott Duncan, an official with Defence Research and Development Canada, has talked with Cramer about quantum stealth. “In an evolved form it may have some interesting applications for military and public security agencies,” he told me in an e-mail. Duncan’s near-comic reserve illustrates how unnerving Cramer’s work can be. We can’t simply trust what we’re looking at. And that, ultimately, is Guy Cramer’s craft. If we’re not entirely sure what we’re seeing, he’s doing his job.