Learn to make your own bubble mixture at home!
This formula keeps your bubbles light and floaty and the addition of glycerin makes the mixture thicker, so you should be able to blow big, long-lasting bubbles. Can you see a rainbow in your bubble?
What you’ll need:
- A container, bucket, or bowl to mix liquids in
- 350ml of distilled water
- 150ml of dishwashing liquid
- 50ml of glycerol (this might also be called “glycerin” at your local chemist shop)
Before you get started, make sure you’ve got a grown-up to help you with this experiment.
You should set your experiment up in a clean space, away from any electrical power sources or equipment.
If you’re doing this experiment outside, check that it isn’t too windy to avoid getting any bubble mixture blown into your eyes.
- Pour the distilled water into your container. Add the glycerol and dishwashing liquid and give it a stir. Set your bubble mixture aside to thicken for 30 minutes.
- While you wait, make a circle out of your piece of wire, leaving enough wire at the end so that you have a handle to hold when blowing bubbles.
- Once 30 minutes have passed, dip your wire in the bubble mixture and have fun blowing bubbles!
The science behind bubbles
What are bubbles made of?
Bubbles are bits of gas or air trapped inside a liquid ball. This is made up of two thin films of soap, with water in between.
Bubbles always hold gas or liquid inside them, with the least possible surface area for any given volume, which is a sphere. Scientists refer to bubbles as “minimal surface structures”.
Why do we sometimes see rainbows on bubbles?
We see the colours on a bubble through the reflection and refraction of the light waves off the inner and outer surface of the bubble wall.
When white light (which contains all the colours of the rainbow) hits the soap films, it gets reflected back, but sometimes it spreads out into a spectrum – or a rainbow.
As the two waves of light (one from the inner surface and the other from the outer surface) travel back, they interfere with one another, causing what we know as colour.
When the waves reinforce each other, the colour is more intense. When the waves get close to cancelling each other out, there is almost no colour.
That’s why sometimes we can see rainbows on bubbles, and sometimes we can’t.
Looking for more activities to do at home?