DARPA: Metamaterials developed to bend sound waves, deflect tsunamis, create invisible armies

DARPA: Metamaterials developed to bend sound waves, deflect tsunamis, create invisible armies: "Metamaterials are simply materials that exhibit properties not found in nature, such as the way they absorb or reflect light. The key is in how they’re made. By assembling the material — from photonic crystals to wire and foam — at a scale smaller than the length of the wave you’re seeking to manipulate, the wave can, in theory, be bent to will."