for National Geographic News
The latest milestone in the quest for a Harry Potter-like invisibility cloak has been reached: a way of bending the geometry of space so that light from all directions travels around an object, rather than hitting it.
Unable to interact with light, the hidden object is therefore invisible, a new study found.
The advance follows on the heels of numerous ballyhooed invisibility advances, each one promising that we're one step closer to magical outerwear or a Star Trek-style spaceship concealer.
But how real is the possibility of an invisibility device? Is it years, decades, or millennia away? Even the author of the latest study doesn't want to hazard too strong a guess.
"I think it's a question of the will and the money put into this field," said Ulf Leonhardt, a visiting professor at the National University of Singapore.
Leonhardt's latest study, to be published tomorrow in the journal Science, is a theoretical calculation of the light-bending properties needed for a new kind of invisibility cloak.
The science behind his study isn't new. "If you look at a fish [in an aquarium] it's not where it appears to be," Leonhardt said.
That's because our brains insist on viewing light as having traveled in a straight line, when in fact the water has bent it.
Glass does the same thing, which is why telescope lenses make objects appear closer.
An invisibility cloak would simply replicate this process in a more sophisticated way, said Leonhardt, who co-authored the study with Tomá Tyc of the University of St. Andrews, U.K.
As recently as early 2005, cloaking was pure science fiction.
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