RENEE MONTAGNE, HOST:
I'm Renee Montagne and - David - David, are you there?
DAVID GREENE, HOST:
Yeah, no, I'm here, Renee. I'm just hiding in a corner of the studio. I don't want the director to see me. He keeps pointing at me, wanting me to talk into the microphone. I don't know why he's doing that. Wouldn't it be cool to have the power to become the invisible?
MONTAGNE: Yeah.
GREENE: I mean, this summer we're hearing about gadgets that give us superpowers like this. Let's hear from NPR's Barry Gordemer.
BARRY GORDEMER, BYLINE: Invisibility as a superpower has been around for a long time.
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GORDEMER: H.G. Wells wrote about it in his novel "The Invisible Man," which became a movie in 1933. Claude Rains starred as a mad scientist who discovers the secret of invisibility.
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CLAUDE RAINS: (As Dr. Jack Griffin) It's easy, really. A few chemicals mixed together, that's all. And flesh and blood and bone just fade away.
GORDEMER: Trouble is the chemicals that made him invisible also turned him into a maniacal killer.
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RAINS: (As Dr. Jack Griffin) An invisible man can rule the world. He can hear every secret. He can rob, rape and kill (laughter).
GORDEMER: (Laughter) Now that's an evil laugh. John Howell is not a mad scientist. He's a regular scientist studying invisibility at the University of Rochester. He was inspired by another movie.
JOHN HOWELL: We want to make a Harry Potter cloak.
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RUPERT GRINT: (As Ronald Weasley) Whoa.
DANIEL RADCLIFFE: (As Harry Potter) My body's gone.
GRINT: (As Ronald Weasley) I know what that is. That's an invisibility cloak.
GORDEMER: Harry Potter sneaked around Hogwarts wrapped in a cloth that would make him disappear. Professor Howell has come up with a way to wrap things in an invisible zone created with lenses.
HOWELL: If we can use a set of optics that exactly replicates how light behaves then you can make a cloaking device.
GORDEMER: The lenses bend light so you see what's behind an object instead of the object itself.
HOWELL: If we can guide light around an object as if it isn't there then we don't know that the object is there. It's like Harry Potter being invisible in Hogwarts. He's still there, but you couldn't observe him because light had gone around him.
GORDEMER: Howell has been able to make small objects invisible, like a pencil, a ruler, even a hand, but everything has to be lined up just so for an object to appear as if it's disappeared. Other scientists like David Smith at Duke University are trying to make invisibility work from any angle. He's experimenting with what's known as metamaterials.
DAVID SMITH: With a metamaterial you can do things that are very unusual, like bend light the wrong way.
GORDEMER: Think of metamaterials as a coating or a wrapper that be put around something to make it invisible. Metamaterials have a texture or structure can steer light in odd directions.
SMITH: If you want to make something invisible and you're sitting on the other side of the object, you would normally see a shadow. To avoid the shadow you have to take the light, pull it around the object and restore it as if it had passed through free space.
GORDEMER: The issue with metamaterials is they're not good at hiding colors, which is a problem in a colorful world. Full Harry Potter invisibility is still a ways off, but the military is already experimenting with existing technologies to see how they could be used for camouflage. Doctors are interested in how it might be used help see around obstructions during surgery.
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GORDEMER: This is music from a YouTube video from the carmaker Land Rover. It demonstrates a car hood that becomes transparent so you can see obstacles in the road, which means you may not have to wait too long to experience a little Harry Potter magic of your own. Barry Gordemer, NPR News. Transcript provided by NPR, Copyright NPR.