Scientists invent not 1, not 2, but 3 new 'invisibility cloaks'
But the cloak from "Harry Potter" is still the most invisible of them all.
Wed, Nov 13, 2013 at 12:08 PM
Cats got one step closer to world domination last week when scientists in Singapore and China premiered a box that could effectively make anything placed inside it invisible. The magical box is just one of three new "Harry Potter"-style invisibility cloaks announced this month, which follow numerous such announcements made so far this year.
The invisibility box comes our way via Dr. Zhang Baile, a researcher with the NTU School of Physical and Mathematical Science. His team's small device — the details of which were published in the journal Nature Communications — is called a "ray-optics cloaking device." It's a small, glass-like box made of more than two dozen internal and external angles that effectively bends light around anything in its center. When light is shone at the semi-transparent box, it passes around the box instead of through it, effectively masking whatever is inside. Zhang and his fellow researchers tested his device with live cats and fish, as you can see in this image from the paper:
Here he demonstrates the cloaking box with a teddy bear and a toy cat:
Granted, this only works in a fixed location and only when the light is moving in a particular direction, but it's still in its early phase, like all of these "Harry Potter" technologies.
The next new invisibility cloak takes a different approach. Instead of trying to render an object invisible to the naked eye, researchers from the University of Toronto are looking into ways to make objects invisible to radar. This research, published in the journal Physical Review X, isn't concerned with optics. Instead researchers have created a "cloak" of small antennas that produce an electromagnetic field capable of cancelling out any radar waves that hit it. So far they have only tried it with a small object, but they say it could be scaled up to hide massive objects such as tanks (yay for military applications) or to make buildings that currently block cellphone transmissions "invisible" to the radio waves.
The third new invisibility cloak comes from researchers at the University of Texas at Austin. Their work, published in Physical Review Letters, aims to beat all other such cloaks. They have developed a new ultrathin electronic system that they say could take an "active" role in invisibility. They say previous cloaks made items invisible only to particular wavelengths – red light, for example – making them "passive" systems. Their new system would be more adaptive to a wider range of situations.
Of course all of these systems are still in their infancy and require a lot more research. None of these "invisibility cloak" are likely to hit the market for years, which gives us all time to re-read the "Harry Potter" books and experience the real thing.
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