Mike Stevens, age 11, of Visalia, Calif., for his question:

HOW DOES A MIRROR REFLECT?

Any smooth surface which reflects light rays rather than absorbs them is a mirror. Most mirrors are made of a sheet of glass which is coated on the back so that the light cannot pass through, but is reflected.

The amount of light that is reflected by a mirror depends on the kind of material, the angle at which light hits it and how polished the surface is. The more mirrors are polished, the more light they will be able to reflect. Even the best mirrors do not reflect all of the light which falls upon them.

When you stand in front of a plane or flat mirror, your image is the same size as yourself and seems to be as far behind the mirror as you are in front of it.