The shape of things to comeMetamaterials make levitation thinkable

We wrote some time ago about scientists at Imperial College London and St. Andrew’s University in Scotland who were doing research of invisibility cloaks. These cloaks rely on so-called “metamaterials,” that is, composites so structured as to let electromagnetic waves flow through them, rather than reflect those waves back (what scientists call “negative refractive index”). In theory, it should work with any wavelength — ultraviolet, microwave, visible, etc. In practice, though, invisibility in the optical spectrum would be challenging because metamaterials will need to be constructed on a scale corresponding to the wavelengths of visible light, which is just a few hundred nanometers. Observers said that constucting such materials would take at least five years. What do you know: Purdue University scientists say they have created a metmaterial that bends “infrared light with a wavelength of 813 nm. This is claimed to be the shortest wavelength yet for such a metamaterial and lies just outside of the visible spectrum at 380