They are the ultimate form of camouflage. Put one on, and you disappear from view. One saved Harry Potter from many tight scrapes, and in the film Die Another Day the technology provided James Bond with the ultimate escape vehicle, an invisible car.
But now Japanese scientists have turned fantasy into reality by creating an invisibility cloak that makes it possible to see straight through its wearer. He, or she, simply vanishes from view.
The garment — demonstrated last week at Nextfest, an exhibition of emerging technologies in San Francisco — is the work of Japanese inventor Susumu Tachi, a professor of computer science and physics at the University of Tokyo.
”It’s a kind of augmented reality,” he said of his device.
In reality, the ”optical camouflage” cloak is anything but invisible. It is made up of ”retro-reflective material” coated with tiny light-reflective beads that cover its entire length. The cloak is also fitted with cameras that project what is at the back of the wearer on to the front, and vice versa. The effect, as the Japanese team demonstrated last week, is to make the wearer blend with his background.
The material was used to coat a ball, a brick and a cloak. In each case, it appeared as if the viewer could see through each item as it was moved about by a human operator to the back of the room.
The effect was not total, but it was sufficient to demonstrate that optical camouflage is technically possible, though one expert — writing in Wired magazine recently — pointed out that, for an invisibility cloak to work, it would have to have six stereoscopic cameras built into it, be covered with 11,6-million ”hyperpixels”, each consisting of a very bright electronic display, and be controlled by a super-fast computer that would run on a power source that could be built into the cloak.
In short, a little more work will be needed before invisibility technology becomes reality, and certainly has some way to go before it reaches the effectiveness of Harry Potter’s invisibility cloak. This originally belonged to his wizard father, James, and is used in Harry Potter and the Prisoner of Azkaban to let Harry move around the wizard village of Hogsmeade unnoticed.
The device is attracting serious attention from military experts keen to exploit a technology that could help troops move into action without being spotted.
Nor does the potential end there, says Tachi’s colleague, Naoki Kawakami.
”It could be used to help pilots see through the floor of the cockpit at a runway below, or for drivers trying to see through a fender to park a car.”
And, of course, there is also the prospect for mischievous, or even dangerous, misuse, from sneaking Celtic fans into the Glasgow Rangers end at Ibrox to wandering into changing rooms unseen. As one expert said: ”This technology has an awful lot of potential.” — Guardian Unlimited Â