Book 1, Question 56
Why Do Rainbows Appear? Light Bends and Splits!
Rainbows look like magic, but they come from light, water and a little science. Sunlight shines into tiny drops of water in the air, bends and splits into all its colors, and you see the rainbow when the Sun is behind you and the water is in front of you. The page says a second, fainter rainbow can appear above the first with its colors reversed. On a sunny day, stand with your back to the Sun and gently spray a hose or spray bottle to try making your own.
From the book
Page from A Million Whys Book 1
More fun facts
- A rainbow is not a thing in one place. It is a light effect that appears when the sunlight, the water drops, and you are all in just the right spots.
- To see a rainbow, the Sun must be behind you and there must be water drops floating in the air in front of you.
- Light slows down and bends when it goes from air into a water drop, because water is denser than air.
- Light bounces off the back of the drop, then bends again as it speeds up leaving the drop.
- A full rainbow is actually a complete circle. From the ground we only see part of it.
- From an airplane, in the right conditions, people can see a whole circular rainbow.
Sources: NOAA
Questions kids ask
Is a rainbow really a circle?
Yes. A full rainbow is a circle, but the ground usually hides the bottom part. From a plane you can sometimes see the whole thing.
Where should I look for a rainbow?
Stand with the Sun behind you and look toward rain or mist in front of you.