We love Science experiments at our house. Hands on is always a hit!! Today we decided to try the fancy little video I have seen floating around facebook with the milk, dish soap and food coloring.
Our first couple of attempts didn't work out well. After taking my Husband's advice and warming up the milk the results greatly improved. Once we finished I did some research and found that the fattier the milk the better....so our 2% probably wasn't the best option.
We did the experiment two ways and we attempted to video tape them both but it turns out our family is loud and doesn't do so well in the background of instructional videos;-)
The first way was to put a thin layer of milk in the bottom of a plate. Then I dropped various dots of food coloring around the milk. Last I dropped in a small amount of dish soap and watched the magic!!
The second way was we repeated steps one and two but applied the dish soap to the ends of qtips and let the kiddos stick them into the mixture. This gave them control of the swirling beauty and they loved it!!!
Now sure this is cool but there is also a great science lesson involved. At first the drops of food coloring just sat on the surface where you placed them. Food coloring is less dense then milk and doesn't mix unless you stir the milk. But with just a drop of soap the magic begins!! The soap dissolves the fat molecules, which is why fattier milk works better. The surface of the milk outside the soap drop has a higher surface tension, so it pulls the surface away from that spot. That causes the food coloring to move or swirl away from the soap. As the soap and the milk get evenly mixed the magic will stop.