Research at Columbia Engineering School has yielded a material that is literally unlike any other known. Everything in the universe (that we can see) affects light one way or another. Slows it down, speeds it up, spreads it out, diffuses it in a certain way, whatever. Even man-made materials with “negative refractive indexes,” themselves unlike anything else in the universe, do something to the light. Not this stuff.
By combining two materials, one with a positive refractive index, and one with a negative, they’ve produced something with an interesting effect: light passes through it as if that material wasn’t even there. It has as zero refractive index. The photons come out the other end of the “nanofabricated superlattice” in the exact phase, angle, etc as they went in.
Sounds kind of cool, you say, but why should you care? Well, being able to control the phase of light in this way means that it can be used in completely new ways of using and propagating photons. Fiber optic communications may be revolutionized, and if the phase control could be expanded to spectra other than visible light, wireless communications could be as well. As always, expect a good five or ten year delay before you hear about real-world applications.