Invisibility cloaks hit the big time: New approach can conceal objects big enough to see

Professor Snape beware — invisibility cloaks aren’t just for the microscopic anymore.

Using natural crystals, two independent research teams have designed “carpet cloaks” that can abracadabra 3-D objects as big as an ant or a grain of sand seemingly into nothing. Up to now, making things invisible has relied on tiny structures called metamaterials. These fabrications are often a mix of stacks and crisscrosses of nano-sized metals and other materials that can guide electromagnetic rays, such as microwaves or infrared and visible light, around objects. If researchers tweak metamaterials just right, they can make tiny things disappear — at certain light wavelengths and from certain angles, at least.