Fantasies, legends, and science fiction stories are crowded with examples of the desire to become invisible, from Greek myths (Perseus hides under an invisibility cloak to sneak up on the sleeping monster Medusa and kill her) to H.G. Wells’s thriller “The Invisible Man” to Star Trek’s Romulan “cloaking device” to invisibility cloaks worn by Frodo and Harry Potter.
Now in two serious scientific papers jointly released by the journals Nature and Science this week, the possibility of making objects vanish – at least to the spectrum of ordinary visible light – appears to be becoming more likely.
Scientists at the University of California describe two kinds of tiny nanoscale structures, called metamaterials, that have shown a “negatively refractive index” – in essence, have the ability to bend light, in the way that looking at an object in water can appear to make it larger or contorted. A release from Nature notes:
Although invisibility is the most attention-grabbing application, metamaterials like this have many more immediate uses in optical technology, for example as powerful new lenses or for carrying light-based signals around microchips.
Previous research has suggested that invisibility might be possible in two dimensions. But the current research proposes a technique that could cloak a three-dimensional object such as a human or a ship.
The AP explains in simple terms how the device might work:
People can see objects because they scatter the light that strikes them, reflecting some of it back to the eye. Cloaking uses materials, known as metamaterials, to deflect radar, light or other waves around an object, like water flowing around a smooth rock in a stream.
Britain’s The Times says the research is another example of how nanotechnology is beginning to impact scientific research:
No such material occurs naturally and it is only in the past few years that nano-scale engineering, manipulating matter at the level of atoms and molecules, has advanced sufficiently to give scientists the chance to create them.