REFRACTION

Broken Pencil Illusion

What has happened to this pencil? It was perfectly normal and intact until someone decided to pour water into the glass. What kind of water does that to a pencil? The water in this picture is actually not special at all: it is ordinary tap water. This pencil is still intact, but it appears distorted because of a property of light called refraction. Refraction causes light to bend when it passes from one substance into another, in this case from air to water. You can test this property with any object, not just a pencil. You may observe refraction affecting your own body when you are at the swimming pool. The parts of your body out of the water may not line up with the parts in the water. This distortion is all due to the bending of light.

The term "refraction" is not exclusive to light. Refraction refers to the turning or bending of any wave, such as light and sound, when it passes through a substance of differing density . Refraction does not occur when light passes from blue-colored water to red-colored water because both waters have the same densities. We most commonly see refraction occur when light passes between air, water and glass.