The MIT Technology Review says that they both pulled their inspiration from the mind grapes of a British student who hypothesized that making objects look like a flat conducting sheet would successfully render an object invisible.

The basic idea is that objects hide under the mirror bump, and tiny silicon nanopillars on the surface of the mirrors steer light away from the object, making it—and the object it's covering—look flat. Technology Review likens this to hiding something under thick carpet.

That means, unfortunately, that this isn't an invisibility cloak we can run around in. These concepts follow suit with the original concept in thinking that a stationary, conductive sheet would work much better for rendering things invisible. So we all can't start skipping out on our dinner bills quite yet.

Still, you can't overlook the importance of taking little steps towards creating an invisible man. Invisibility is cool, even if just a concept in a lab somewhere. [Invisibility Cloak One and Invisibility Cloak Two via MIT Tech Review via KurzweilAI]

Waves pass along the radial corridors, interacting with the pillars and producing forces that pull the water away from the innermost ring. The water is then pushed out of the cloaking area as if it had not encountered anything at all. The circular formation could be used to protect anything from oil rigs to islands, though very few islands can probably afford the amount of pillars needed to make this effect work. [New Scientist via Dvice]