Here we set up a convection cycle, where we heat part of a fluid; it expands, rises, then cools and sinks. A two dimensional model for real convection cycles in the atmosphere, oceans or stellar interiors.
Evaporation of water on duck's head cools vapor inside causing low pressure, etc.
How it works:
Dippy Duck is a small heat engine consisting of a hollow glass barbell with opposite ends able to seesaw about a knife edge pivot. One end of the barbell is...