NegativeRefractiveIndex
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Researchers build a working tractor beam, on a very small scale
We recently saw research that suggested negative radiation pressure in light could lead to a practical tractor beam. A partnership between the Czech Republic's Institute of Scientific Instruments and Scotland's University of St. Andrews can show that it's more than just theory: the two have successfully created an optical field that flipped the usual pressure and started pulling objects toward the light. Their demo only tugged at the particle level -- sorry, no spaceships just yet -- but it exhibited unique properties that could be useful here on Earth. Scientists discovered that the pull is specific to the size and substance of a given object, and that targets would sometimes reorganize themselves in a way that improved the results. On the current scale, that pickiness could lead to at least medicinal uses, such as sorting cells based on their material. While there's more experiments and development to go before we ever see a tractor beam at the hospital, the achievement brings us one step closer to the sci-fi future we were always told we'd get, right alongside the personal communicators and jetpacks.
Negative radiation pressure in light could make some tractor beams real, we're already sucked in
Developing a real, working tractor beam has regularly been an exercise in frustration: it often relies on brute force attempts to induce a magnetic link or an air pressure gap, either of which falls a bit short of science fiction-level elegance. The Technion-Israel Institute of Technology's Mordechai Segev has a theory that would use the subtler (though not entirely movie-like) concept of negative radiation pressure in light to move objects. By using materials that have a negative refraction index, where the light photons and their overall wave shape move in opposite directions, Segev wants to create a sweet spot where negative radiation pressure exists and an object caught in the middle can be pushed around. His early approach would use extremely thin crystals stacked in layers to manipulate the refraction. As it's theorized, the technology won't be pulling in the Millennium Falcon anytime soon -- the millimeters-wide layer intervals dictate the size of what can be pulled. Nonetheless, even the surgery-level tractor beams that Segev hopes will ultimately stem from upcoming tests would bring us much closer to the future that we've always wanted.
Researchers develop metamaterial with negative refractive index
We've got next-to-invisible objects and cameras with ridiculously large sensors, and thanks to a team of brilliant researchers over in Germany, now we've got "an exotic material with a negative refractive index for visible light." Gunnar Dolling and his colleagues at the University of Karlsruhe in Germany have created a metamaterial with layers of silver sandwiching a thin sliver of nonconducting magnesium fluoride on a glass sheet, and once an array of square holes were etched in, his tests showed that the "structure had a negative refractive index of -0.6 for light with a wavelength of 780-nanometers," besting the previous record of 1,400-nanometers. While the scientific babble may not mean much to you, the long and short of it is that this discovery could "lead to further breakthroughs in invisibility cloaks, which could hide objects from the human eye" and make escaping your troubles quite a bit easier. Moreover, the technology could be used in "superlenses" to see details "finer than the wavelength of visible light," but Dolling is reportedly more interested in studying the effects of his discovery than attempting to build any mystical devices, which is probably for the good of mankind, anyway.[Via Slashdot]
Japanese researchers invent completely transparent material
In a breakthrough that could benefit fields as diverse as networking, photography, astronomy, and peeping, science-types at Japan's Institute of Physical and Chemical Research have unveiled their prototype of a glass-like material that they claim to be 100% transparent. Unlike normal glass, which reflects some of the incoming light, the new so-called metamaterial --composed of a grid of gold or silver nanocoils embedded in a prism-shaped, glass-like material -- uses its unique structural properties to achieve a negative refractive index, or complete transparency. Although currently just a one-off proof-of-concept (pictured, under an electron microscope), mass-produced versions of the new material could improve fiber optic communications, contribute to better telescopes and cameras, or lead to the development of completely new optical equipment.
