How to Make Rainbows at Home

This week, Onetime and I had fun exploring some different ways of creating rainbows at home and we’re going to share those with you today.

I’ve also rounded up lots of other fun rainbow activities that you might be inspired to try with your kids.

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To Make Rainbows – You Will Need:

• • a flashlight or a sunny day
  • a mirror (at least 5″ by 5″)
  • a pan of water
  • a CD
  • a prism (we used this one: Tedco Light Crystal Prism – 2.5″)
  • some white paper
  • a small cue card
  • a tall, clear straight-sided glass of water

What Makes a Rainbow?

Before we began our rainbow making adventures, I talked with Onetime a little bit about how sunlight is made up of many colours all put together.

A rainbow appears when the light gets split up into its 7 different colours: red, orange, yellow, green, blue, indigo and violet. Sometimes referred to as “Roy G. Biv”

Usually – the reason the light gets split up is because it is passing through a substance that bends the light. The different coloured wavelengths bend in different amounts.

Red tends to bend the least, so it appears on the top of the rainbow, while violet bends the most and ends up on the bottom – with all the other colours in between.

When we see a rainbow in the sky, it is usually when the sun is behind us and it is shining through millions of tiny raindrops floating in the sky – all of which are bending the light and projecting the rainbow.

(Did you know that sometimes – rainbows appear at night too? Read this post to find out about Moonbows!)

In any case – we don’t need raindrops to make a rainbow. Here are our 5+ different ways to make rainbows of your own INSIDE!

1. Making Rainbows with a Mirror 

Let’s start with the easiest! Fill a large bowl or dish halfway with water and prop up a mirror inside it so that part of the mirror is under the water and part is out.

Place the rainbow maker near a sunny window with direct light coming in so that it hits the mirror (early morning or early evening light works best).

Play around with holding a large white piece of paper above the maker to “catch” the rainbow. You might have to move a bit until you find it.

Play around with moving the paper closer to the mirror and then farther away to see how your rainbow changes!

SAFETY NOTE: Just like you should never look directly into the sun, be sure that you do not look directly into the reflection from the mirror. It can damage your eyes. If you are at all concerned about this with your child, instead of using sunlight, try a darkened room with a strong light source instead.

2. Making Rainbows with a Glass of Water

When light goes through a glass of water – it also splits into a rainbow.

To get ready – take a piece of paper and cut a slot into the middle of it. Tape this onto the side of a smooth/clear drinking glass so that the sun’s rays can pass through the opening onto the SURFACE of the water in the glass.

You will need to do this on a very sunny day (or try a darkened room with a strong direct light source.)

Make sure that the glass of water is VERY FULL. Place the glass on a white floor or white piece of paper, making sure the sun’s rays are shining through the slot in your paper and hitting the surface of the water.

You should see a mini-rainbow appear below the glass!

Have your child describe the colours they see and you can talk about rainbows you have seen in the sky and how they are similar or different.

3. Making Rainbows with a Prism

If you’re lucky enough to have a crystal chandelier at home, or a hanging crystal decoration, you may not need to buy a prism. We didn’t – so I picked one up at our local kids’ toy shop.

Basically, all I did was place a large piece of white paper on the floor beside our living room window that lets in lots of direct sunlight in the morning.

Onetime figured out pretty quickly that by moving it around, he could make a rainbow beam appear on the paper.  He had lots of fun moving the prism in different ways and exploring how to change the size of the rainbow.

If you happen to have 2 of the standard prisms, you can have the light pass through one prism (which then breaks into a rainbow) and enter the other prism – which then bends it back into white light. Cool huh?

For other prism play ideas, check out Rainbow Prism Busy Bag, and Prism Play and Chalk Art.

4. Making Rainbows with a CD

You can make this really simple and just hold a CD up to some sunlight – or shine a flashlight on one in a darkened room – and you will see a rainbow on the CD.

Or go a little further, and try to catch the reflection of the light on some paper!

The reason why a rainbow appears is because there are tiny ridges in the surface of the CD that are reflecting the light in different directions. To read more about the science behind CD rainbows – check out this post at Exploratorium.

5. Making Other Rainbows

Other ways we didn’t try: misting a hose on a sunny day with the sun behind you, looking for rainbows in bubbles and oil slicks, wearing rainbow glasses (okay maybe that one doesn’t count!)

We plan on waiting for a warm spring day to try these out! For even more ideas and tips – check out this Rainbow Making WikiHow.

More Rainbow Activities

Experience colour mixing and crazy sensory fun with Rainbow Goop

Build a Fine-Motor Rainbow to work on fine-motor skills and to create a beautiful craft.

Make Milky Rainbows with ingredients from your kitchen.

Try making our St. Patrick’s Day Shamrock Math Bin for a fun search for gold and counting fun under the rainbow.

Other Rainbow Ideas

• Rainbow Fine Motor Play at Sugar Aunts looks like colourful fun.
• St. Patrick’s Day Rainbow Slime from Left Brain Craft Brain is glittery awesomeness!
• The New Rainbow Jello, Soda Bottle Rainbow craft, yummy-smelling Rainbow Rice, and Sort a Rainbow activities from A Little Pinch of Perfect will keep the kids busy.
• This St. Patrick’s Day Learning Pack from Totschooling has lots of shamrocks, gold and rainbows.
• This Rainbow Retelling bracelet craft from Growing Book by Book can be used with any story to build comprehension and retelling skills.
• Love this Liquid Rainbow Jar from Playdough to Plato for learning about density.

Picture Books for Learning About Rainbows

To find some excellent children’s books to learn more about rainbows – click on the picture below!

Hope you found some fun rainbow learning activities for your kids today. We certainly learned a lot and had a few very colourful days at home with these activities!

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