Rainbow Milk DIY

Materials you'll need

• Paper towel
• Scissors
• Washable markers (red, orange, yellow, green, blue)
• Dish soap
• Milk
• Shallow plate

 

Step-by-step tutorial

Step 1: Cut a paper towel into a circle about the size of your palm.

Step 2: Color the circle in rainbow rings, starting from the outer edge and working in — red, orange, yellow, green, and finishing with blue or purple in the very center.

Step 3: Add one drop of dish soap right in the center of your colored circle.

Step 4: Pour milk into a shallow plate until it forms a thin layer covering the bottom.

Step 5: Place the circle face down, right in the center of the plate.

Step 6: Watch as the colors burst outward from the center, blooming into a rainbow flower pattern across the milk.

Step 7: Repeat with a new colored circle to add more blooms to the same plate of milk.

Learn more

This experiment is a tug-of-war between fat and soap. Milk isn't just white water; it's full of tiny fat droplets floating around, calm and settled. Dish soap molecules have two different ends: one end loves water, and the other end loves fat. The fat-loving end zooms toward the fat droplets in the milk and pulls them apart, and all that molecular commotion drags the marker ink along for the ride, painting swirling rainbow patterns across the plate. Once the soap and fat molecules settle into place, the colors stop moving, until you add a new circle and process starts all over again.