Physics — Reflecting on Reflections

Diffuse reflection occurs when light reflects from a rough surface. The reflected rays are scattered in diffuse reflection. This scattering occurs because the local direction of the normal to the surface is different for the different rays. (The normal is a line perpendicular to the surface at the point where the incident ray reflects.) By contrast, regular reflection is reflection from a smooth surface, such as a mirror. In regular reflection, the reflected light rays are orderly because each local region of the surface has a normal in the same direction.