In ancient Egypt, people used pieces of polished metal as mirrors. Why do some materials reflect light so perfectly? What kind of materials make good mirror?
Some materials reflect light better than others. Good reflectors are usually shiny and bright when light is shined on them. If you look at a good reflector you may see yourself clearly. If you look at a poor reflector your reflection may be blurred or not there at all.
Imagine that you and your friends have a basketball. Where would you rather bounce the ball, on a gym floor or on a dirt road? It is easier to bounce a ball on the gym floor because the floor is smooth.
Think of a beam of light as a stream of tiny particles. If the beam of light hits the surface of a flat mirror. The beam bounces off the mirror like basketball would bounce off a smooth gym floor.
What happens when light hits an uneven surface? The particles of light are scattered. When this happens, the light is not reflected evenly.
A good mirror is a very smooth reflector. Reflectors are used in cameras, flashlights, telescopes, microscopes.
