Home www.play-hookey.com Wed, 09-23-2020

Reflection, Part 2

Now that we have seen what reflection means and how light behaves as it reflects, let's take a look at a couple of special cases. Here, we look at reflecting surfaces that are smooth but curved. As you look at these examples, think of the distortions caused by the mirrors you might see in a fun house. Mirrors bent like this are entertaining, but can also be quite useful.

 If the reflecting surface is convex as shown to the left, parallel rays of light striking the surface will diverge from each other evenly. This type of reflector might be used to help illuminate a wider area from a single source of light, or to reflect light onto a shadowed space and allow a wider spread of illumination. In the reverse direction, converging light rays reaching a convex mirror will be reflected to be more nearly parallel to each other. If you look at a large image reflected in such a mirror, it will seem to be smaller to your eye, because of that convergence. If you look at your reflection in a Fun House mirror of this type, you will find that the farther away you are from the mirror, the larger the portion of your body reflected to you appears in the convex portion, but your reflection is always right side up. This type of mirror, with only a mild curvature, is used to allow a magnified view of a limited area. A typical application is for makeup application, since it allows closer and more accurate control of exactly where and how the makeup is applied. Another application is the right side mirror on an automobile. The convex surface allows the driver to see a wider angle, for better coverage. However, as the warning on that mirror says, the result is that objects reflected in the mirror appear smaller than normal, and so seem to be farther away than they really are. This is a reverse application of a convex mirror, since it takes converging light rays and bundles them together.