Mirror Mirror on the Wall...how do you Work?

How mirrors are made? How reflection occurs?
- Corinna Walker
Valley High School, Orderville, Ut, America

Most of the mirrors you see around you are made up of three layers. The bottom layer is a dark protective layer, the middle is a layer of metal (like aluminum, silver, or tin), and the top is just glass. Glass is used on top because it is smooth, clear, and protects the metal. A mirror needs to be very smooth in order for the best reflection to occur. You may have noticed that light can reflect off of many smooth surfaces, such as the side of a car, a pond, a spoon, or even the computer screen you a looking into right now. Reflections occur when light particles, called photons, strike a surface that is so smooth that the photons will bounce back and not be distorted. For example, a jagged rock will not likely reflect light like a mirror, because the photons will be sent off in lots of directions. Also, for a good reflection to occur, the surface should be made of a kind of metal. Smooth metals reflect light better than say, smooth plastic, because of the way the metal atoms share electrons and can reflect the photons of light. Other substances around you absorb too much light to act as mirrors.

A reflection in a mirror occurs when light strikes an object in front of the mirror, then bounces to the mirror, and then to your eyes. Since mirrors have the properties described above (they are smooth, shiny, and metallic), the photons of light can bounce off in pretty much the same direction from which they came. When this happens, the image of the object that the photons originally hit is replicated in your eyes.

-B.Y.

(published on 10/22/2007)