Rainbows appear when the Sun is shining and it’s raining at the same time. That doesn’t happen very often. But you don’t have to wait to see rainbows—you can make them. It’s easy. Go out with a spray bottle on a sunny day. Stand with the Sun behind you and spray water into the air. You should see your very own rainbow!
WHAT MAKES A RAINBOW?
A rainbow is made by light bouncing back to you from the insides of raindrops. Ordinary light, like that from a light bulb or from the Sun, is called white light.
White light is actually a mixture of seven colors. Light bends when it passes through water. Each color bends a different amount. When white light enters a raindrop, the colors get separated. The white light splits into seven colors that you can see.
These seven colors always appear in the same order: red, orange, yellow, green, blue, indigo (bluish-purple), and violet (purple).
Sometimes you see two rainbows, a bright one inside a faint one. Here’s why double rainbows form. When light enters a raindrop, a lot of it bounces off the back surface of the drop. This light comes back out of the drop and makes a bright rainbow. Some light, however, bounces around inside the raindrop a couple more times before it manages to escape. This smaller amount of light makes the faint second rainbow. Every rainbow is actually a double rainbow, but the bigger one is usually too dim to see.
POTS OF GOLD?
It looks as though rainbows touch the ground at each end. People sometimes say there’s a pot of gold at the end of a rainbow. Unfortunately, you can never get to the end of a rainbow. You can’t see a rainbow when you’re too close to it. The light comes at you from the wrong angle. If you move toward a rainbow it just seems to get farther away and disappear.