1. Pour some milk onto a plate.
2. Add some drops of food colouring to the milk.
3. Squirt a small amount of washing-up liquid into the centre of the plate of milk.
4. See what happens! (But don't drink the milk afterwards!)
■ What happens when you add lots of tiny drops of food colouring?
■ What happens if you just use red and blue food colouring or yellow and green?
■ What happens if you add two or three drops of washing-up liquid around the edges of the plate?
■ Place a piece of paper on the surface, then lift off and you’ve made a print!
The science behind magic milk
Milk is made up of molecules that pull each other together. These molecules stretch and turn the surface of the milk into an invisible skin. This is called ‘surface tension’. When you add the washing-up liquid, it changes the surface tension so that the milk molecules move around, mixing the food colouring together.
Edited extract taken from See Play Do by Louise Cuckow, Beatnik Publishing,
hardback RRP$34.99, paperback RRP$24.99, beatnikshop.com.