Drinking bird

Back to 4C - Change of state
PIRA index: 4C31.30

Description

The drinking bird is a heat engine. It is made of two connected glass bulbs filled with dichloromethane and installed on the rim of a container filled with water. The evaporation of the water on the 'head' will lower the pressure inside suck the liquid in the head, tipping the bird into the water. Once the pressure and temperature inside are back to equilibrium, the bird's head goes back up and new water starts to evaporate and the process starts again.

Equipment

• Drinking bird
• Glass of water

Instructions

Put drinking bird on the rim of the glass (or next to it depending on the design). As long as there is water, it will tip back and forth.

Keywords

heat engine, evaporation, water, hypnosis