I learned a lot in my physics class, but one of the most important life lessons came from the day we studied rainbows. The unit was optics and we had just learned about refraction and reflection. As other noders have pointed out, rainbows appear when light is refracted in a raindrop and then reflected off of the other surface. To see this amazing phenomenon, one must be at exactly the proper angle with the sun behind his or her head. Finding the correct angle is not hard with millions of raindrops, but since each color requires a specific angle to be seen, placement of the eye does matter. If I see a rainbow standing in the middle of my yard and then move five feet to the left, I may still see a rainbow, but the colors will be coming from a slightly different area to make precisely the correct angle. After understanding this, I learned that both literally and metaphorically, since two people cannot possibly occupy the same space at the same time, everyone sees a different rainbow.