GOT MILK?

KILEY CRUSE | World-Herald Staff Writer

Keep the learning going over the summer with this tie dye milk science experiment.

Though the science behind it will be over their head, this experiment is so easy even preschoolers will have fun doing it.

When you dip a dish soap coated Q-tip into a plate of milk that has a few drops of food coloring, magic happens. The food coloring will being to swirl all on its own. Touch the Q-tip in a few places and you’ll have a tie dye pattern.

WHAT’S THE SCIENCE BEHIND THIS TIE DYE MILK EXPERIMENT?

Milk is mostly water, but it also has proteins, fats and other molecules mixed in. Because it’s mostly water, it acts a lot like water and has many of the same properties. One of these properties is called surface tension. Surface tension is how resistant a liquid is to external force, or how strong the surface of the liquid is. (It’s a bit like the surface of water having a sort of “skin.” This is how some insects can walk on water.) Soap is a surfactant. It lowers the surface tension of a liquid. When we dip the soap in the milk, it lowers its surface tension and causes not just the water molecules, but fat and protein molecules, to move as they quickly rearrange themselves. By adding food coloring, we can see the movement caused by lowering the surface tension. The food coloring will swirl around in interesting patterns, as if by magic.

Tie Dye Milk Science Experiment

• Liquid food coloring

• Dish soap

• Q-tips

• Milk

• Pie plate

1. Pour the milk into the pie plate adding just enough to cover the bottom.

2. Add 4 to 6 drops of food coloring to the milk.

3. Dip a Q-tip into the dish soap and place in the milk (don’t stir!). Watch the food coloring move creating a tie dye look!