Why does a rainbow always have the same colors in the same order?
Breaking sunlight into colors
Let’s talk science!
I just love summer rain, Mark. It cools everything down… and sometimes it brings a rainbow!
Yeah! Summer wouldn’t be the same without those colorful rainbows. Remember when we talked about why the sky is blue? We said that a rainbow appears when sunlight is split into the colors it’s made of. But… have you noticed the rainbow always has the same colors in the same order?
Hmm, you’re right! It’s always red on top, then orange, yellow… and at the bottom, there’s blue and purple. But why?
I’m not sure… Let’s ask the teacher, they’ll know!
The teacher explains
A rainbow appears when sunlight passes through tiny drops of water in the air. Each drop acts like a little prism – it bends and splits the light into its basic colors.
Why this exact order?
Sunlight is made of many different wavelengths. Red light has the longest wavelength, while violet has the shortest. When light enters a water droplet, each color bends at a slightly different angle. Red bends the least, so it’s always on the top of the rainbow, while violet bends the most and ends up at the bottom.
Cool, right?
That’s why a rainbow always has the same color order: red, orange, yellow, green, blue, indigo, and violet. And if you ever see a double rainbow, the second one has the colors reversed!
Mini experiment
Take a glass of water and place it in sunlight. Look carefully at the wall or floor – you’ll see a tiny “piece of a rainbow”! You can also do this with a glass prism if you have one.