Tie Dye Milk Experiment

The other day my daughter and I completed what we both thought was a very cool science experiment.  It's called Tie Dye Milk.  It's a very simple experiment with a very cool result.  To start, fill a bowl/saucer with milk until the bottom is covered.  Then place a few drops of food coloring (different colors) on different places of the milk's surface.  The food coloring may spread a little, but not by much.  In a separate bowl, mix a 1/2 cup of water with a teaspoon of dish soap.  Then the fun begins.  Take a Q-tip and dip it in the water/soap mixture.  Place the Q-tip on a food color spot in the milk.  At the moment of contact the food coloring will quickly disperse throughout the milk.  I was very impressed with how quick the food coloring dissolved.  Below is the video of our attempt.

As you can see, the color quickly disperses.  So what is going on here?  The Q-tip soaked in the water/soap mixture breaks the surface tension of the milk, allowing the food coloring to quickly move from one point to another.  You can do this over and over until the colors completely mix.  My daughter and I did it a few times and continued to be impressed.  So give it a try.  You probably have these materials already in your home and your kids will love it.