No hiding it, invisibility is here
Kazutoshi Obana's jacket which is part space material, part camera trick.
Photo: AP
October 20, 2006 - 12:59PM
This is University Of Tokyo student Kazutoshi Obana with his version of a cloak of invisibility, using optical camouflage technology, in 2003.
The disappearing coat is part space-age material, part camera trick. A video camera behind the coat sends footage to a projector, which bounces the image off the front of coat's reflective surface much like a movie screen works.
But now a team of American and British researchers has developed its own cloak of invisibility in Washington.
The researchers have announced their own method of making an object partially invisible by passing microwaves and radar waves over its surface....
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According to Dr. Tachi, "[This invisibility cloak] is made of retro-reflective material so that the coming light is reflected back to the same direction that it comes from. Microscopic beads on the surface of the coat have the function of retro-reflection. A half mirror makes it possible for a spectator to see virtually from the position of the projector. An HMP projects an image of the background scenery captured by the video camera behind the camouflaged subject. A computer calculates the appropriate perspective and transforms the captured image to the image to be projected on the subject using image-based rendering techniques. Since the cloak the subject is wearing is made of a special retro-reflective material which reflects the incident light [in] the same direction it comes from... an observer looking through a half mirror sees a very bright image of the scenery [behind the subject] so that he [becomes] virtually transparent."
BBC NEWS | Science/Nature | Experts create invisibility cloak
Scientists develop
'invisibility cloak'
Tabloid News - 20/10/06 - Neil Davey
MegaStar says: ‘Come on, boys.
What practical use is that?
To think you could have spent all that effort
working on time travel…’
From Star Trek to Bond via, of course,
Harry Potter, cloaking devices have long been the
thing that fantasies were made of.
Now, however, it’s a reality.
A team of British and American scientists have developed an invisibility cloak that can make people, planes, cars, tanks and ships disappear. Sadly though, it only works with radar screens.
In order to work with the human eye, the cloak would need to bend light waves which – as yet and, sadly, probably never – is not possible. The device, however, works with microwaves and radar.
The device "grabs" the waves that head towards it and then makes them flow smoothly around the object. This means the object – whatever it may be – becomes invisible on radar. If you’re struggling to picture it, just think of a big rock in a river…
The principle would be the same for a “real” invisibility device, however scientists suggest that technology will never be advanced enough for that. Microwaves are easier to manipulate though as they have a wavelength 30,000 times longer than light waves.
Professor Sir John Pendry, a theoretical physicist at Imperial College, explained that "the cloak has got to do two things. One is to deflect any waves away from the object, because if it reflects, it can be seen.
"The second is to get rid of the shadow. It is a challenge because the waves have got to be released so it appears they have been going in the same direction and have not been deflected by any object."
Despite these requirements, the team have created a test device which works. They also believe that bigger devices will be easier to produce.
In an announcement that won’t come as a surprise to anyone with half a brain, “the American military have provided the funds”.