ELI5: What causes rainbows?
Imagine the sun is a big lightbulb, and rain is like a bunch of tiny mirrors hanging in the air.
Here's how a rainbow appears in nature:
- Sunlight: The sun's light looks white, but it's actually made of all the colors mixed together! Think of it like a box of crayons with every color inside.
- Raindrops: When sunlight hits a raindrop, something cool happens.
refraction. It's like when your straw looks bent in a glass of water. Because each color bends a little differently, they start to spread out.
The light bounces off the back of the raindrop, like hitting a mirror. This is called reflection.
As the light leaves the raindrop, it bends again* (refraction) and separates even more into all those different colors!
- The rainbow's arc: You only see a rainbow when the sun is behind you, and the rain is in front of you. All those raindrops are acting like tiny prisms, splitting the sunlight into its colors. The millions of raindrops together make a big arc of color in the sky.
- Why a bow? Rainbows are actually circles! But we usually only see a part of the circle (an arc) because the ground gets in the way. If you were in an airplane, you might see the whole circle!
How was this explanation?
Follow-Up Questions
Still curious? Ask a follow-up!
Test Your Understanding
Take a quick quiz and challenge your friends!
📧 Get this explanation by email
Receive this explanation in your inbox, plus get weekly simple explanations of trending topics!