Refraction
Wednesday, February 10, 2010 @ 3:06 AM
What has happened to this pencil? It was normal until someone added water into the glass. What kind of water could do this to a pencil? The water in this picture is actually not special at all, because it is just 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 medium to another medium of different densities
You may observe refraction 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 which is known as Refraction.
There is such a thing called Snell's law which is a formula used to describe the relationship between the angles of incidence and refraction, when referring to light or passing through a boundary between two different mediums, such as water and glass.
It can be calculated using this simple equation:
( n=sin i/sin r )
where n being the refractive index, i being the angle of incidence and r being the angle of refraction.
***When light is travelling from a less dense medium to a denser medium, it will bend TOWARDS the normal, and when light is travelling from a denser medium to a less dense medium, it bends AWAY from the normal.