Here is the science behind why this experiment works: "Food coloring is less dense than the milk itself - so it remains suspended within the fat molecules of the milk. The dish soap breaks up the fat molecules, which then spread across the surface of the milk. As the molecules break and expand, they create movement in the milk and pull the food coloring along for the ride!"
After thinking about why this experiment works, Jack was able to explain to me why skim milk or water would not yield the same results (or any results at all)...some great critical thinking skills by Jack!
Here are a few pictures of Jack and Eve conducting this experiment: