Do light rays reflect many directions on a smooth surface?

Answer 1

Wherever a light ray hits the reflecting surface, the angle of reflection is equal to the

angle of incidence. Both angles are measured with respect to the normal (perpendicular)

to the surface at that point, so if the surface is bumpy, and the normal to it is different

directions in different places, then light rays will reflect in several directions. But if the

surface is really a smooth plane, then every light ray that is incident in the same direction

will reflect in the same direction. The whole art and science of controlling where reflected

light rays go is really the ability to control the shape of the reflecting surface, and the

normal to it at different points on it.