Rainbows and Dispersion

Rainbow

           This is a picture of me spraying a watering hose in the sunlight, which produces a rainbow. How does this beautiful phenomenon occur? Well in physics class this week, I learned the concept of refraction, or the bending of light. Light bends, or changes directions when it travels from one medium to another. This is because light travels at different speeds in different mediums. In this case, light passes through air, then through water, and back into the air. Light refracts into the water, then reflects internally, and refracts once more back into the air. Visible light, which is also known as white light, consists of many colors. Red, orange, yellow, blue, green, and violet separate when passing through a refracted material or specifically a prism. Each droplet of water acts like a prism that disperses the light and reflects it back to your eyes. Because each color has a different frequency, they bend at different angles. Because they bend at different angles, the colors of the rainbow appear in a predictable order each time it rains. This process is called dispersion.