An artistic little experiment to do – using science to marble colours in milk.
What you need:
- shallow dish
- milk (full cream milk works best)
- different coloured food dyes
- dishwashing liquid
- cotton tip
What to do:
- Pour milk into a dish so it covers the bottom.
- Place drops of food dye all around the milk.
- Put some dishwashing liquid onto the cotton tip.
- Touch the cotton tip to the milk in different positions.
- Watch the swirls appear.
You can make a print of your image by placing a piece of paper over the milk, carefully lifting it up and letting it dry.
What happens:
It is the fat molecules in the milk that are affected by the dishwashing liquid, which is why full cream milk works best for this experiment. The dishwashing liquid is attracted to parts of the fat molecules in the milk, and they try and move to be together. The food dye is less dense than the milk so it stays on the surface of the milk. As the fat molecules move around, the food dye on top goes along for the ride, mixing with other food dye when it comes into contact.