Journal Entry 9/28

1. When light reflects off of the water of a calm pond, the incident angle is the same as the reflected angle, with respect to the normal line at that point. If a light ray were to hit a rock at 60 degrees, that rock would then reflect the ray at 60 degrees. The reflected ray would hit the surface of the calm pond at 60 degrees and be reflected once more at 60 degrees. If that same pond was disturbed by a flock of birds, the motion of the water and the figures of the birds would be reflected, as opposed to the landscape of trees and such. 3. Rays reflect off of the handle of the spoon undisturbed (the incident angle is the same as the refracted angle), so when you look at the handle through the side, nothing is changed. In contrast, the rays that hit the surface of the water before touching the spoon experience refraction. When a light ray moves from air to water, it moves away from the normal. Let's say that a ray was entering the water at an angle of 35 degrees. A normal could be created at the point where the ray hits the water. Instead of continuing straight at 35 degrees though, the angle is refracted away from the normal. The refractive index for water is 1.33, and 1 for air, so to find the degree of refraction, you would take the sine inverse of the product of the refractive index for air multiplied by the sine of 35 degrees divided by the refractive index for water. Completion of this calculation results in 25.447 degrees. This means that a light ray entering the water at 35 degrees shifts 25.5 degrees away from its normal, upon entry into the water. The principle of refraction applies to the entire portion of the spoon under the water. As a result of so many refracted light rays, pieces of the spoon look distorted when looking through the side of the cup.