From KurzweilAI.net — I’ve blogged on 3D cloaking devices before, very likely the previous KurzweilAI.net linked blog post from mid-May is an earlier report of this project. Both stories originate from UC Berkeley.
At any rate, here’s 3D cloaking part two:
Practical Cloaking Devices On The Horizon? PhysOrg.com, Aug. 10, 2008University of California, Berkeley scientists have created a multilayered, “fishnet” metamaterial that unambiguously exhibits negative refractive index, allowing for invisibility in three dimensions for the first time, Nature magazine plans to report this week.
Update — Here’s another take on this story, once again from PhysOrg. This time with pictures!
From the link:
Two breakthroughs in the development of metamaterials – composite materials with extraordinary capabilities to bend electromagnetic waves – are reported separately this week in the Aug. 13 advanced online issue of Nature, and in the Aug. 15 issue of Science.
Applications for a metamaterial entail altering how light normally behaves. In the case of invisibility cloaks or shields, the material would need to curve light waves completely around the object like a river flowing around a rock. For optical microscopes to discern individual, living viruses or DNA molecules, the resolution of the microscope must be smaller than the wavelength of light.
The common thread in such metamaterials is negative refraction. In contrast, all materials found in nature have a positive refractive index, a measure of how much electromagnetic waves are bent when moving from one medium to another.
In a classic illustration of how refraction works, the submerged part of a pole inserted into water will appear as if it is bent up towards the water’s surface. If water exhibited negative refraction, the submerged portion of the pole would instead appear to jut out from the water’s surface. Or, to give another example, a fish swimming underwater would instead appear to be moving in the air above the water’s surface
And here’s the image: