A property of a material that changes the speed of light, computed as the ratio of the speed of light in a vacuum to the speed of light through the material. When light travels at an angle between two ...

Introduction If you pour water into a clear glass, what color is it? It's clear, right? But what happens if you try to look through it to see the world on the other side of the glass? It looks a ...

The negative refraction of electrons in graphene has been seen for the first time in experiments done by physicists in the US. The work represents an important advance in the fabrication of graphene ...