Daily Archives: April 1, 2006

Magic Milk

A few days ago, Aya herself reminded me that we haven’t done any experiments in a while. Uh-oh. I had been too wrapped up with so many things that I forgot to devote some time for this. I said OK. Right away Aya took out the book and chose which experiment we’d perform! I obliged, even if it was a weekday. As much as possible I wanted to do the experiments on weekends, where we have more time to spend. Anyways.

This experiment is relatively easy to do. Things you will need: Plate, milk, food coloring, and washing-up liquid. This experiment illustrates a literally colorful way to explain surface tension of liquids.

With the book wide open in front of her, Aya prepares the things needed.
Since we only had powdered food coloring, Aya has to dissolve each color in separate cups. We only have two colors, actually – red and yellow. We just combined the two colors to make orange. It would have been nice to have blue, though!
Next we pour milk onto the plate. The milk has to fill the plate up to the rim.
Aya adds food coloring to the milk by the spoonfuls.
Next, Aya drops a small amount of washing-up liquid onto the center of the mixture.
The washing-up liquid breaks the surface tension, and the milk molecules move apart. As the milk moves, the colors run into one another.What was really cool about this experiment is that once Aya poured the washing-up liquid, the mixture began moving and pulsing as if alive. Aya watched in fascination as the different colors began moving right before her eyes! We could even make out images of a flying bird, hehe. Parents, do try this at home with your kids! Highly recommended.