Why Does a Mirror Reflect Light?

mirror-reflect-light Credit: *Vintage Fairytale*/CC-BY-2.0

According to Scientific American, all objects reflect light, but very few reflect light in a way that allows one to see an image like that seen in a mirror. This is due to a certain type of light reflection called specular reflection. This type of reflection doesn't scatter light. Instead, it directs light directly back toward the observer, which allows for a clear image.

Light isn't seen by the human eye until it's reflected from an object. In the case of a silver mirror, a standard glass mirror with a silver-lined back, the light passes through the glass, hits the silver and reflects back toward the observer. However, some light is also reflected back from the glass as well. Since glass and silver reflect light differently, the result is a clear image and an intense reflection of light.

In addition to specular reflection, there are two other types of light reflections: reflected light and diffuse reflection. Reflected light occurs when light beams hit a smooth surface, and the light is then reflected in the opposite direction at the exact same angle. When light hits an uneven surface, however, the light beam is scattered in all directions, which is called diffuse reflection.