German scientists Tolga Ergin and Nicolas Stenger at the Karlsruhe Institute of Technology have created a small-scale, 3-dimensional invisibility cloak that works in the infrared spectrum, very close to visible light wavelengths. Previous cloaks like this have only worked when viewed from one direction, which doesn’t help protect you from Predators, ’cause they could be anywhere. In trees, on the bus, they could even be disguising themselves as your grandma (I’ve read about wolves doing that, so you know it’s legit).
The trick is to change the speed and direction in which light travels through the material – that is, to change the material’s refractive index. The researchers achieved by this using a polymer crystal made up of very tiny rods. “By changing the thickness of the rods, you can change the ratio of air to polymer,” explained Dr Ergin. “Since the refractive index of air is about one and the refractive index of the polymer is about 1.52,” he explained, “in principle, we can get any refractive index between those two numbers,” he said. By tailoring the refractive index of the surface of the bump, the scientists rendered it invisible to a wide range of light wavelengths slightly longer than those that we can see. [BBC]
In order to create a 3-D cloak of this type in the visible spectrum, the rods would have to be reduced from their current size down to around 10 nanometers. Current laser techniques produce rods around 200 nanometers or larger. Why you always gotta be peeing in my cheerios, Reality? Can’t you see I’m trying to hide from Predators here? Shut up, Reality, they are to real.