Reflection

Reflection of light is very predictable. The Law of Reflection describes it simply as "The angle of incidence is equal to the angle of reflection."

Law of reflection:
' = where is the angle of incidence and ' is the reflected angle from the normal.

Yeah, that is great for flat surfaces but what about curved surfaces? It works the same way. Simply draw the tangent line to the point of the curve and reflect the light according to the tangent line.

There are actually two types of reflections: specular and diffused.

Specular reflection is reflection from a smooth surface. When light strikes this smooth surface, all the reflected rays are in line with each other.

Diffused reflection is reflection from a rough surface. The small bumps and irregularities on a rough surface will cause each of the light rays to reflect in different directions, all following the law of reflection of course.

See also: Interactive Virtual Experiments and Demonstrations

Next article: Mirrors, mirrors, on the wall.