Invisable Cloaks Aren't Just Sci-Fi

[marby]

"Japanese boffins spawn almost invisible man"

Robin McKie, science editor
Sunday June 13, 2004
The Observer

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.'

Now you see it, now you don't: cloaking device is not just sci-fi

Ian Sample, science correspondent
Wednesday May 3, 2006
The Guardian

It's been the curse of the USS Enterprise and the Klingons' favoured weapon. But back on Earth, mathematicians claim to have worked out how to make a cloaking device to render objects invisible.
An outline for the device is described in a scientific paper published today in which the authors reveal how objects placed close to a material called a superlens appear to vanish.

Even in the world of science fiction, the technology is not perfect, and nor is the device proposed by Graeme Milton at Utah University and Nicolae-Alexandru Nicorovici at Sydney University of Technology. According to their calculations, the device would only work at certain frequencies of light, and only if the object is within close range of the superlens.

The cloaking device relies on recently discovered materials used to make superlenses that make light behave in a highly unusual way. Instead of having a positive refractive index - the property which makes light bend as it passes through a prism or water - the materials have a negative refractive index, which effectively makes light travel backwards. It's light, but not as we know it.

Prof Milton's team calculated that when certain objects are placed next to superlenses, the light bouncing off them is essentially erased by light reflecting off the superlens, making the object invisible.

The calculations show that while the device could be used to obscure almost any shape of object, it only works over a short range of wavelengths, so if used to hide objects from human vision, they might only partially disappear.

Sir John Pendry, a theoretical physicist at Imperial College London who invented superlenses, said: "Effectively, they are making a piece of space seem to disappear, at least as far as light is concerned."

The research appears in the journal Proceedings of the Royal Society today. Prof Pendry said the technology has great potential for hiding objects from radar or cloaking electronic instruments so they can be used in strong electromagnetic fields, such as those produced by hospital MRI brain scanners. "The secret is having the cloak itself be invisible and if you can do that cheaply and efficiently and it doesn't need to be metres thick, it would be extremely valuable for stealth. Even if you could cloak a single frequency, it would be very useful. The military is extremely interested in this."

So far the researchers have only worked through the mathematics to prove that the device is plausible. The practicalities of making one have yet to be solved.

Cool

[jojo22]

Ooooooo - that's what I want for Xmas. That and the ability to teleport anywhere I want to go instantaneously (now that is a prospect that should really make the oil companies sh*t themselves)

[Guest]

[jojo22]

Yeah - there's a point - there was some talk not long ago about microchipping children I shudder to think where that would lead.

[Guest]

There must be a way of turning water into a solid and walking on it. Hey isnt that what Jesus did? Or turning water into wine. I wonder if Jesus knew how to transmute the elements?

[boingo]

The US military has been working on invisiibility suits fow some yeas now. There was a TV series, hosted by Gillian Anderson, called: "Future Fantastic" where the story was briefly meantioned. Allegedly a high ranking military official saw the invisiblility suit on th film "Pretator" and said: "I want one of those", and the project was born.
During the recent Gulf War 2, there were sightings by the Iraqis of shadows moving around the US tanks. They, allegedly, believed what they saw were ghosts helping Iraq. I think it's more likely that it was US soldiers field testing the invisibility suits.

[Guest]

[Guest]

Ghosts stalk Thai tsunami survivors
By Tony Cheng
BBC News, Phuket

Lek looks nervously at the Patong sea shore as he describes the passengers who climbed into his tuk tuk minivan late at night on 6 January. "Go to Kata Beach", the seven foreign tourists told him, after agreeing on a 200 baht fee.

He drove a while, but then felt numb all over his body. Looking around he saw the cab was empty. He had had what he thinks was an encounter with the ghosts that many say are haunting the beaches and resorts on Thailand's Andaman coast. And the religious charms he wears around his neck are not helping him overcome his fears.

"I can't get over this. I'm going to have to get a new job. I have a daughter to support, but I'm too scared to go out driving at night," he said. Lek's experiences are by no means unique. Other apparitions which have been reported include a foreign woman, whose screams echo through the night from the wreckage of a hotel that was particularly badly hit.

A security guard on the site has already left his job because he could not bear it anymore. In Khao Lak, a local family say their telephone constantly rings through the day and night. When answered, the voices of friends and relatives cry out to be rescued from the flames of the crematorium.

Such reports, according to psychologist Dr Wanlop Piyamanutham, are signs of post traumatic stress disorder. He pointed to the fact that many stories started to appear about 10 days after the wave struck. That was when the real horror of the loss and devastation hit people, he says. Now it is spreading beyond those immediately affected.

"With all of the pictures on the television, and everyone talking about the disaster, it affected many more people, who have reported seeing ghosts and smelling corpses," he said. And Dr Wanlop has an explanation for why such a large number of "foreign" ghosts have been seen.

"Foreigners make a big impression on Thais," he said.

"They're physically imposing, and often seem rich and powerful. If people like that die in terrible circumstances, it's not surprising they should come back in people's minds as ghosts, especially when they have so far to get home."

Peace of mind

That might provide a logical explanation, but it does not provide much comfort. For that, many Thais have turned to Buddhism, the majority religion in the country. Although superstitious beliefs are common in Thailand, with many houses incorporating a spirit house to appease local ghosts, Buddhist scripture has guidance on dealing with the supernatural, much of which is a remnant of previous animist religious practices which pre-date the arrival of Buddhism. Local folk beliefs have given monks the power to dispel troubled spirits, and many are prepared to provide "protection" if it is needed.

"We can do nothing to ward off the spirits", says the venerable Bhikkhu Sugandha, "but if it helps make people feel more comfortable, we can be around to comfort them." He believes that in a period of crisis, monks can provide a very useful counselling service.

"At such times religion is very important because there is nothing else. The service the monks provide is just to listen, to be there, and to let them know that there is someone more grounded to listen." Other religions are offering more direct help, and Patong beach has seen several "exorcisms" performed by Chinese spiritualists in the last few weeks.

In one, white robed monks from the Pu Ta Gong sect chanted prayers and offered sacrifices of food to the spirits. Special offerings of pizza were included for foreign 'spirits', and paper clothes and money were burned to help in the passage to the after world. As clouds of incense drifted down the white sand and over the calm blue waters, the troubled spirits of the dead and missing were urged to return home, for the sake of the peace of mind of the living.

[swee]

[swee]

[Guest]

[swee]

Me neither.

[jojo22]

[swee]

[Guest]

I can just imagine them sneaking about in invisable cloaks, they could be doing anything, it makes me cringe.