Air (feathers) as thermal insulator

Principle

In this experiment, students observe the cooling of hot water in two screw-top jars. One of the glasses is surrounded by pieces of paper in a beaker. In doing so, they notice that insulation made of air ensures that the water in this screw-top glass cools down more slowly. In addition, they expand their knowledge of the concept of insulation, that cooling is not only slowed down by direct shielding with an insulating material as in the last experiment, but also by a protective layer of air.