Invisibility cloaks may not be useful at macroscopic scales
AUG 01, 2016
DOI: 10.1063/PT.5.029992
New Scientist : Passive invisibility cloaks, which redirect light around objects without needing additional energy, may not be possible for macroscopic objects. Andrea Alù and Francesco Monticone of the University of Texas at Austin have shown that the size of the cloak and the range of wavelengths that it could redirect are inversely proportional. A cloak large enough to cover a person would redirect only a specific color of light, whose wavelength would be narrower than even the best lasers can produce. The researchers say that active cloaks, which use input energy to redirect or reemit light, may still be possible.
© 2016 American Institute of Physics
