Unit 10 Post - 7/20: Light Refraction!

Did you know that light travels at different speeds in different mediums? This causes light to bend which manipulates how you see things in glass or water opposed to in air. The fastest light can possibly travel is 3X10^8 m/s. A new value, the index of refraction ("n") is a ratio for how fast light travels in a specific medium. The lower the "n" value, the faster it travels in that medium. The n for air is 1, for water is 1.3, for glass is 1.5, and for diamond is 2.42. This explains why objects are distorted when looked at through water or glass! The formula used to find this is called "Shell's Law": n(1)(sine of theta1) =  n(2)(sine of theta2). The light bends and makes the position and orientation appear differently! If light is traveling from a fast medium to a slow one, it will bend towards "normal" (perpendicular to the surface) from the path it was originally on. But if it's traveling from a slow medium, like glass, to a faster one, like air, it will bend away from the "normal" of the surface. Light can also get trapped! The n of the first medium is greater than the n of the second (a slow to fast medium), light can't escape that medium and will reflect within it as a result. The angle at which this will start to happen is called the critical angle. You calculate this using the formula: sin-1(n2/n1)!