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buglerbilly
19-03-10, 05:04 PM
Harry Potter: 'invisibility cloak' prototype created by scientists

A prototype "invisibility cloak", similar to those worn by fictional wizard Harry Potter, has been developed by European scientists.

By Andrew Hough, UK Daily Telegraph

Published: 9:00AM GMT 19 Mar 2010

An invisibility cloak, as worn by Harry Potter, could soon become a reality. British and German researchers have created the three-dimensional that can hide objects by bending light waves, which could pave the way for larger objects to be made invisible.

While the cloak of invisibility has played a major role in fiction and movies, it appears that scientists have taken a small, but important new step, toward making it reality.

Invisibility cloak 'in five years' In their study, researchers from the German Karlsruhe Institute of Technology and Imperial College London used the cloak, made using photonic crystals with a structure resembling piles of wood, to conceal a small bump on a gold surface.

In their study, published Thursday in the American journal Science, they rendered almost entirely invisible the bump that measured 0.00004 inches high by 0.00005 inches across, by "cloaking" it in a new material.

Invisibility cloaks have already been developed but they only worked on two dimensions.

In other words, the objects that were supposed to be made invisible were immediately visible from the third dimension, the study said.

The "cloak" invented by the European team is the first to work on three dimensions.

It is composed of special lenses that bend light waves to suppress light as it scattered from the tiny bump the researchers were trying to make disappear, the study says.

"For now these ... cloaking devices are just a beautiful and exciting benchmark to show what transformation optics can do," said Tolga Ergin, who led the research.

“This is very exciting, because mankind has always thought about being invisible or having invisibility cloaks.

"This is the first proof of principle. It shows that the technique works.

He added: "The value of the finding is that we learn more about the concepts of transformation optics, and that we have made a first step in producing 3-D structures in that field.”

He cautioned that it likely be years before anything as large as a person, car or tank could be made to disappear with this technique.

"There have been proposals in the field of transformation optics for different devices like beam concentrators, beam shifters, super antennas which concentrate light into one point from all directions, and much, much more," he said.

"It is really hard to say what the future will bring, but the field is definitely very broad and the possibilities are very large."

buglerbilly
03-02-11, 07:40 AM
Amazing scientific breakthrough: paper clip made invisible

February 3, 2011 - 4:13PM


Fiction ... A still from the old Invisible Man TV series starring Vincent Ventresca ... and fact, a paper clip which scientists can now make invisible using crystals.

Scientists are a step closer to creating a cloaking device after making an object visible to the naked eye disappear for the first time.

In the past, researchers have only been able to "cloak" microscopic objects using extremely complicated physics and so-called meta-materials made on a tiny scale.

But a new study at the University of Birmingham in the UK has taken a major step forward by making a paper clip invisible - an object thousands of times bigger than in previous experiments.

The research works by using a naturally forming crystal called calcite which has extraordinary light-bending abilities.

By placing the crystals over an object it "bounces" light around it rendering it invisible to the naked eye.

Dr Shuang Zhang, a physicist and lead investigator on the University of Birmingham team, said: "This is a huge step as, for the first time, the cloaking area is rendered at a size that is big enough for the observer to 'see' the invisible object with the naked eye.

"By using natural crystals for the first time, rather than artificial meta-materials, we have been able to scale up the size of the cloak and can hide larger objects, thousands of times bigger than the wavelength of the light."

The new technique is limited only by the size of the naturally formed crystals.

Calcite crystals can be up to 21ft long, so it could be used on a car or a military vehicle.

It may also be possible to manufacture crystals with similar qualities.

Dr Zhang explained: "Previous cloaks have succeeded at the micron level - which is much smaller than the thickness of a human hair - using a nano- or micro-fabricated artificial composite material.

"It is a very slow process to make these structures and they also restrict the size of the cloaking area.

"We believe that by using calcite, we can start to develop a cloak of significant size that will open avenues for future applications of cloaking devices," Dr Zhang said.

The research is published this week in the journal Nature Communications.

The Telegraph, London

Read More: http://www.telegraph.co.uk/science/science-news/8296871/Invisibility-cloaks-the-future.html