Jan 15, 2009 | 1
Look out, Harry Potter: researchers have advanced the study of cloaking—rendering objects invisible by forcing light waves to act as if the objects weren't there.
In a paper published in this week's Science, a team from Duke University and Southeast University in Nanjing, China, reports a new and improved cloak that can conceal a bump—and anything hidden beneath—on a flat surface. Both the surface and the bump (visible at the far left in the photo) must be reflective, however. The new setup is upgraded to function for a relatively broad spectrum of light, whereas previous models had very narrow operational regimes.
This cloak, like its predecessors from the group of David Smith, an electrical and computer engineering professor at Duke, is built from metamaterials—novel composite structures designed to make light work in unusual ways.
Aug 12, 2008 | 5
Researchers have taken the next step on the road to constructing a cloak of invisibility or a powerful "superlens" capable of capturing fine details undetectable to current lenses. A group from the University of California, Berkeley, this week is publishing the first demonstrations of materials capable of bending visible or near-visible light the "wrong" way in three dimensions.
Both are examples of metamaterials—specially designed structures that cause light to do things it normally wouldn't—in this case, bending backward, an effect called negative refraction. Researchers have built metamaterials capable of negatively refracting microwaves, but despite some successes bending visible light in two dimensions, they've had a harder time making three-dimensional versions.
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The Dow Chemical Company is the leading producer of polyalkylene glycols (PAGs) used in synthetic fluids and lubricants where petroleum,
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