Make a Rainbow

A rainbow forms in the fine spray from the hose

A rainbow is often a welcome sight when the sun comes out after a rain storm. Find out how to make your own rainbow when there’s not a cloud in sight!


  • A sunny day
  • A hose with a mist attachment
  • An open sunny space, such as a back yard

Safety first!

  • Always be sun smart when outside during the day – wear a hat, sunscreen, and clothing that covers as much of your skin as possible. 
  • It’s safest to stay in the shade in the hottest part of the day – fortunately, this experiment works best when done in the morning or afternoon.
  • Be aware that the wet ground might be slippery. Consider doing this experiment on a grassy area or near a garden so the water you use won’t go to waste!


  1. Stand in your sunny space with the sun behind you. You should be able to see your shadow in front of you.

2. Turn on your hose. If your hose attachment has a choice of nozzles, choose the one that makes the water drops the smallest – for best results it should be a fine mist.

3. Move the spray around in front of you until you see a rainbow form in the droplets!

A rainbow forms in the fine spray from the hose
Get the angle just right, and you'll see a rainbow form in the fine mist from the hose!

Further investigation

  • While looking at your rainbow, try moving to a different spot in your sunny space. Does the rainbow appear in the same place it did before?
  • If you are doing this experiment with a friend, get them to stand a short distance from you. Can they see your rainbow too? What if they have a turn with the hose and make their own rainbow – can you see it from where you are? 

What's happening?

A rainbow forms when sunlight hits small drops of water in the air. Water is denser than air, so the light slows down and bends (refracts) a tiny amount when it enters the water drop. The light bounces around inside the raindrop, then exits again at a different angle.

White light is actually made up of lots of different colours mixed together, but our eyes see them as six distinct colours – red, orange, yellow, green, blue, and violet. Each of the different colours that make up white light bends a slightly different amount inside the water drop. When the light exits the water drop, each of these colours shows up as a distinct band.

The location of the rainbow that you see depends on the angle between your eyes, the sun, and the water drops. When you moved, your eyes (hopefully) moved along with you – and therefore, so did your rainbow. Someone standing in a different spot in your back yard won’t see the rainbow in the same place you do – they might not even see it at all!

When you see a rainbow in the sky, there are usually many more water drops than you can make with your hose, so lots of people can see it at the same time. However, everyone will see it in a slightly different place depending on where they are standing. And unfortunately, this means that it’s impossible to visit the end of a rainbow. (Sorry.)

More on this topic

  • Rainbows are very mathematical – visit this site to learn more about the maths behind how they are formed.
  • You now know that viral images such as this one, claiming to show ‘a rainbow viewed from above’, don’t show anything of the sort! This cool rainbow-coloured phenomenon isn’t necessarily fake though…it could be due to polarisation of the window glass. But that’s another story…

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Myth Busting Monday: Rainbow Shapes

A rainbow arches over a country road after rain

You can’t help but feel happy when you see a rainbow. They’ve been interpreted as divine messages, adopted as symbols of various causes and movements, and used to decorate just about anything you could imagine. So it might surprise you to learn that one of the most recognisable features of the rainbow is not actually as it seems…

A rainbow arches over a country road after rain
There is more to a rainbow than meets the eye. Image by Free-Photos from Pixabay.

Myth: A rainbow is a semi-circular arc

Truth: There is more to a rainbow than meets the eye. The semi-circular arc is simply the part of the rainbow we can see – the rest is usually obscured by the ground.

First things first – how does a rainbow form?

A rainbow forms when sunlight hits small drops of water in the air. Water is denser than air, so the light slows down and bends (refracts) a tiny amount when it enters the water drop. The light bounces around inside the raindrop, then exits again at a different angle.

As we know, white light is made up of lots of different colours (Red, Orange, Yellow, Green, Blue, Violet) which all have different wavelengths and therefore different amounts of energy. The colours with longer wavelengths (the ‘red’ end of the spectrum) bend less than the colours with shorter wavelengths (the ‘violet’ end). This is what causes the light beam to split into that recognisable spectrum of colours that is so familiar to us.

White light is separated into its component colours (red, orange, yellow, green, blue, violet) by a triangular prism
White light is separated into its component colours (red, orange, yellow, green, blue, violet) by a triangular prism. Image by Lucas V. Barbosa - Own work, Public Domain,

Where can I see a rainbow?

The rainbow you see depends on where you are standing relative to the light and the raindrops. The sun has to be behind you, and the rainbow will form at an angle of 42 degrees from something called the ‘antisolar point’, which is roughly marked by the shadow of your head.

(In other words, if you drew a line from the shadow of your head to your eyeball, and another line from your eyeball to the rainbow, the angle between the lines would be 42 degrees.)

This means that if the sun is lower in the sky, the rainbow will appear higher, and vice versa.

Can I go to the end of the rainbow?

The rainbow’s position depends on your eyes’ position. This means that if you move slightly, so will the rainbow that you see. And someone standing next to you will see the rainbow in a slightly different position. And THAT means that it’s literally impossible to walk to the end of the rainbow. (Sorry.)

That’s a shame. Are you going to tell me what shape a rainbow is?

Of course. Consider that 42 degree angle you drew before, between your head shadow, your eye, and the rainbow. The water drops at the correct angle from your eye to form a rainbow aren’t just in one spot. They’re in an arc, all around your eye. ALL around, meaning that if you replaced the ground with a bunch more water droplets (or your vantage point was high enough), the rainbow you’d see would be a complete circle!

Mind. Blown.

A circular rainbow over the ocean
When viewed from a high enough vantage point, a rainbow will appear as a full circle. Photo by Jakob Owens from Stocksnap.

That’s amazing! But…there’s a but, isn’t there?

Yep. But…if you’re ready to have your mind blown even further, consider this.

Rain isn’t usually two-dimensional. It doesn’t just fall in a sheet and make a line on the ground. It’s three-dimensional – and so the rainbow-forming droplets also take up a three-dimensional space.

A rainbow therefore isn’t a fixed distance away from you, the observer – it can be anywhere there are droplets of water at the correct angle. If you are unlucky enough to be standing in a solid rainstorm with the sun shining behind you, there are rainbow-forming droplets everywhere from right next to your eyeballs, to several kilometres away.

So a rainbow isn’t just a two-dimensional circle…it’s actually a three-dimensional CONE. With your eyeballs at the point, and your head-shadow (the antisolar point) at the centre of the cone’s base.

Next time you see a rainbow, make sure you inform the nearest fellow observers that it is, in fact, a rainbow CONE.

And if you’ve managed to get your head around this, head on down to your nearest ice cream shop and treat yourself to a triple-scoop cone – you have certainly earnt it.

Rainbow swirl ice cream cone
Another slightly more delicious kind of rainbow cone. Photo by Key Notez from Pexels.

Need more detail? Here is a more in-depth look at the maths behind rainbows (external link).

Use your new-found rainbow knowledge to make your own rainbow at home.

Bang! Crash! Smash! Science!

Our Year One workshop focuses on the Australian Curriculum concept that “Light and sound are produced by a range of sources and can be sensed”.

So it’s probably little wonder that this is the noisiest of all our workshops, discovered recently with the help of the Year Ones of St Mark’s Primary School in Inala.

The children enjoyed making as much noise as possible with our great range of instruments and noisy everyday objects.

Children making noise in the name of scienceMore scientific noise-making










As well as the noisemakers, the workshop includes experimenting with light, colours and optical illusions. And they all got to try on the latest scientific fashion accessory – rainbow glasses!

Everyone wearing rainbow glasses

(It’s hard to tell from the picture, but the lenses of the glasses split light into rainbows, so everything the wearer looks at is edged with rainbow colours.)

They also had the chance to experience a bug’s-eye view of the world.

Bug's eye view


Thanks St Mark’s, we had lots of fun visiting your students!

Our Year One program isn’t the only one that focuses on the Australian Curriculum learning outcomes – in fact, all of our school programs do! Contact us to find out more about bringing a fantastic curriculum-based science lesson to your school.