Scientists at Germany’s Karlsruhe Institute of Technology have created a real life Invisibility Cloak. it’s not quite as cool as Harry Potter’s, though, mostly because it’s really, really tiny. Their cloaking device managed to prevent the detection of a .00004 inch high and .0005 inch across lump of gold in nearly visible infrared frequencies. Not that you could see it in the first place without a magnifying glass. Lead researcher Tolga Ergin says that, “in principle the cloak design is completely scalable; there is no limit to it.” Unfortunately, developing one of these new cloaks takes a long time, “so cloaking larger items with that technology is not really feasible.” He has hope, however, that, “other fabrication techniques, though, might lead to larger cloaks.
So why is this cool? It’s the first time that anyone has managed to make a cloaking device work in three dimensions. Cloaking has been managed before, but only in a two dimensional fashion. Earlier research at Duke University developed a way to cloak objects in two dimensions from microwaves. Like light and radar, microwaves usually bounce off objects, making them visible to instruments and creating detectable microwave shadows. This cloak is a structure of crystals, stacked together with open air between them, that bends light around the object it’s hiding.
The value of the find lies less in being a step towards actual invisibility and more in it being a step forward in transformation optics, a new field that is working to control the flow of light. Learning to control and manipulate the flow of light could lead to advances like computers and electronic devises that use light instead of electronic signals to process information, incredibly powerful microscopes that might be able to see things as small as DNA, advanced sensors and more efficient solar collectors. Plus the whole power of invisibility thing. Seems pretty cool to us.