An anonymous reader alerts us to work out of Purdue University in Indiana, where researchers have produced a design for a method of cloaking objects of any shape and size at a single wavelength of visible light
. The math for such an invisibility effect was worked out last year at Duke and in the UK, but the new work, to be published in Nature Photonics this month, is the first practical design. The lead researcher, Vladimir Shalaev, notes that even though the current design works only at a single wavelength, and so would not convey true invisibility, it could still be useful — against, for example, night-vision goggles or laser target designators. Shalaev calls the technical challenge of producing an all-wavelengths cloak "doable in principle."