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 ...

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 ...

Light bends when travelling through a concentration gradient of sugar in water. The top layer of liquid is pure water while the bottom layer is concentrated sugar water. In these layers, there is no ...