(Please excuse the poor quality of the photos. Something is wrong with my camera, but it was all that I had handy this particular day. Hoping to get it fixed soon.)
What you need:
- large bowl of cold water (or fill the kitchen sink)
- petroleum jelly
- winter glove or mitten
- latex glove
What You Do (Experiment #1):
- Spread petroleum jelly on the back of one hand.
- Immerse both hands in the water.
- Pull out your hands and observe them.
- Talk about what happened and discuss the differences of how the water reacted differently to the two hands.
- Talk about your experience compared to that of a penguin diving into water.
Before diving into the water, penguins do something called preening - coating their stiff, outer feathers with oil that they secreted in an oil gland near the base of their tail feathers. This oil acts as a barrier against the water, protecting the softer, downy feathers underneath and keeping them dry.
What You Do (Experiment #2):
- Put the winter glove or mitten on one hand (to represent the penguin's downy undercoat and blubber blankets).
- Over that, put the latex glove (to represent the penguin's outer coat of oiled feathers).
- Now immerse the double-gloved hand and the bare hand in water. (Be careful not to let water seep in through the wrist opening of either glove.)
- Which hand feels warmer and drier and why?
How is this like a penguin?
The penguin has a layer of fat called blubber underneath a layer of downy soft feathers. These two layers insulate the penguin and keep it warm in the same way that the winter glove kept your hand warm. Penguins spread a thin layer of oil on their outer stiff feathers. This layer of oily, stiff outer feathers keeps the underneath layer of downy feathers dry in the same way that the latex glove kept the winter glove dry.
Both of these experiments were fun, simple, and helped us to make a good connection with the scientific concepts.
Hands-on learning is the best!