What Makes a Rainbow?
Rainbows are a lovely natural phenomena caused by the same principle by which glass prisms cast colored light. Light from the sun enters the raindrop and is refracted and reflected off the back of the raindrop into your eye. Different wavelengths of light refract at different angles. For example, blue light is reflected back at a sharper angle (40 degrees) than red light (42 degrees).
In the learning object above, drag the raindrop up and down. As you move the raindrop lower in the sky, the angle relative to the eye makes it appears as red. As it descends further, it moves through all the colors of the rainbow, eventually becoming ultraviolet as it disappears from vision.
A rainbow is created by millions of raindrops, each at a different angle and each reflecting a different color into the eye of the beholder.
© 2003 Leo Brodie