There have been talks about a Harry Potter-like invisibility cloak for years and now a group of researchers at Berkley have constructed a material that can bend light around 3D objects. The disappearing act (light bending effect) is essentially the same effect (reversing refraction) that makes straws in water appear as though they are bent.
The material, which doesn’t occur in nature, is made on a nano scale that measures in billionths of a meter. Previous forays worked on a microwave wavelength that we, feeble humans, cannot see. The newly produced material works on a wavelength closer to that used in the telecom industry, which is a bit closer to the visible spectrum. The Berkley team made two different sets of metamaterials; one made from nanometer-scale stacks of silver and magnesium fluoride arranged in a “fishnet” structure, while the other used silver nanowires.
Light is neither absorbed nor reflected by the objects, passing “like water flowing around a rock,” according to the researchers. As a result, only the light from behind the objects can be seen.