How to Make a Rainbow at Home

This is such a fun activity for a warm, sunny day – make a rainbow with the garden hose! It is so simple to do and the results are just a little bit magical.

How to Make a Rainbow

You will need:

• A sunny day
• A garden hose with a fine mist nozzle (or you can place your thumb over the end of the hose to create a fine spray – this makes it trickier for kids though)

To make your rainbow:

1. Stand in the sunshine with your back to the sun.
2. Point the hose in the direction of your shadow and turn it on.
3. Watch the spray against a dark background such as the grass, a dance or wall and check out your rainbow.

How Does It Work?

First there are two things to understand about light. Firstly, sunlight isn’t light of just one colour, it’s made up of different colours mixed together. Secondly, light travels in waves and these waves usually travel in straight lines through space, unless something interrupts it, or it travels through another material.

When sunlight shines on water droplets made by the hose (or rain) the water refracts the beams of sunlight and separates them into the different colours that were previously all mixed together.

What does refract mean? It means to change the direction of a ray of light, which is exactly what happens when the light travels through the water. Things that refract light bend it. A rainbow happens when raindrops refract light, breaking it from a whole into its component colours.

To understand more about the science of light, check out this post at Explain That Stuff.

For more great colour science experiments, plus color activities teaching the other STEM topics of technology, engineering and mathematics, as well as art, literacy and cooking, check out Kaleidoscope: Hands On Color Activities for Kids. It’s a great resource for parents, teachers, youth and community leaders.