How to Make a Rainbow

Did you know the light around us ( white light ) is called is actually made up of all the colours of the rainbow.

What are the colours of the rainbow?

Red, orange, yellow, green, blue, indigo and violet

Rainbows are seen in the sky opposite the sun and are caused by the refraction ( bending of light ) and dispersion ( splitting up ) of sunlight in drops of rain or mist. Sunlight hitting the rain or mist is dispersed into its constituent colours this is because the light is reflected at varying angles, creating a rainbow because the different colours refract and bend by different amounts. Each colour of the rainbow has a different wavelength.

What is Refraction?

Refraction is when light bends as it passes through a transparent material for example, glass, prisms, rain drops.

How to make a rainbow on a sunny day

Make a rainbow with a hosepipe

If you have a spray bottle or hosepipe that can make a fine mist of water you can make a rainbow on a sunny day.

Stand with your back to the sun and spray the hosepipe into the air. You might have to move it around to find the best angle for a rainbow.

Why can you see a rainbow through water?

Tiny drops of water act like a prism, splitting light into individual colours depending on their wavelength. Violet light is bent ( refracted ) the most and red the least.

The bending of light is called refraction and the splitting up of light into a rainbow of colours is called dispersion.

If you have a sunny day you can also use a prism to make a rainbow.

Make a rainbow with a Mirror

Or try placing a mirror inside a glass and angling the glass so sunlight hits the mirror. You should be able to reflect a rainbow onto the wall.

Make a rainbow without the sun

Place a mirror inside a glass and shine a torch onto it until you can see a rainbow reflected onto the wall. You might have to adjust the angle of the glass to make it work.

If you can make a room very dark you might also be able to see a rainbow by shining a torch through a prism.

Find Rainbows in Bubbles

When white light shines through the bubble film, it is reflected and dispersed which splits the white light into its different wavelengths allowing you to see all the colours of the rainbow in the bubbles.

Rainbow Crafts for kids

Make rainbow paper like The Science Kiddo

We love this rainbow scavenger hunt from Hands on as we Grow.

Or how about a giant collage like The Imagination Tree?

Suitable for Key Stage 2 Science