Remember that evil piece of ^&$* called Snell's law ? Well, finally, I am pleased to say : He was wrong. Take that, Bijon, I told you so !(Even if I was not necessarily thinking of um... whatever : He was wrong !).
All known materials, tilll now, had a positive refractive index...
"But scientists from the University of California at San Diego described in Friday's issue of Science a strange composite that has a negative index, essentially reversing Snell's law. This new mix of fiberglass and copper rings and wires (see image) is far more than a curiosity, the researchers say. It may very well lead to novel electromagnetic devices and even perfect lenses, unhindered by diffraction limits and thus capable of focusing light in unforeseen ways.
Sheldon Schultz and his colleagues produced the class of composites last year, predicting at the time that it would defy a number of ordinary properties, including the Doppler effect. Their recent demonstration is only the first of what they hope will be several to reveal the composites' unorthodox behavior. In this case, they showed that microwaves—at the same frequency as those used in police radar guns—emerged from the material in the exact opposite direction from that predicted by Snell's law. Next they hope to extend the material's powers to focusing visible light. "
And a few months after this, along came the nearest thing to an invisibility device that we have today...
Okay.. first things first : these devices are made out of metamaterials; what the bloody F#^$ are metamaterials, you ask ? "A metamaterial is a composite structure, built of metal rings and wires embedded in fiberglass, that makes light behave in weird ways. Metamaterials can be used, for example, to bend light sharply or to focus it to a higher resolution than is normally possible. More recently, researchers pointed out that the technology should make it possible to construct spheres or cylinders capable of cloaking an object almost perfectly from detection by a single wavelength of light. When light strikes a metamaterial it causes the electrons in the metal pieces to vibrate; these vibrations in turn affect the speed of the light. A metamaterial shell with the right gradient of metal elements should cause light of a particular wavelength to wrap around the shell's interior. "
Soon, they hope to be able to conquer the challenge of completely cloaking an object from the visible frequency... ahh the prospects of such a device ! Are you pondering what I'm pondering ?
- Rasevaudez, Debayan.
