What is a rainbow?
A rainbow is a big, pretty band of colors you can see in the sky when the sun shines while it is raining. It looks like a colorful arc or half‑circle.
Step-by-step: How a rainbow is made
- Sunlight is white. It looks white, but it is actually made of many colors mixed together.
- Raindrops act like tiny prisms. When sunlight enters a raindrop, the light bends. This bending is called refraction.
- Light reflects inside the drop. The light bounces off the back of the drop and comes out again.
- The white light splits into colors. As the light bends and comes out, the colors separate so you see red, orange, yellow, green, blue, indigo, and violet.
- Many drops make a curved band. Each raindrop sends just one color of light to your eyes. Lots of drops together make the whole arc of colors you see.
The order of colors
The colors from the top (outside) of the rainbow to the bottom (inside) are:
- Red
- Orange
- Yellow
- Green
- Blue
- Indigo
- Violet
People remember this order with the name "ROY G BIV" (one letter for each color).
Why is it curved and why can't you find the end?
A rainbow is actually a circle of colors, but the ground usually blocks the bottom part so we see an arc. The rainbow moves when you move, because it depends on the angle between the sun, the raindrops, and your eyes. That means you can never walk to the rainbow's end — it will always move with you.
What about a double rainbow?
Sometimes you can see two rainbows. The second one is fainter and has the colors reversed because the light bounced inside the drops two times.
Fun, safe experiment you can try with an adult
- Find a sunny window or go outside on a sunny day.
- Fill a clear glass with water and place it on a table where the sun shines through it.
- Put a white piece of paper on the floor or table where the light from the glass will hit.
- Move the glass a little until you see colors appear on the paper. These are the same colors as a rainbow!
Safety tip: Never look directly at the sun. Ask an adult to help.
Quick facts
- Rainbows appear when sunlight and raindrops are both in the sky.
- No two people see exactly the same rainbow; it depends on where you are standing.
- Sometimes you can see rainbows at waterfalls or from a hose if the sun lights the water just right.
Try to spot a rainbow next time it rains and the sun comes out. Have fun!