Drinking bird

Description

Who doesn't know this one from the 60s and 70s. The original "drinking bird". Drinking Bird works using the properties of thermodynamics, converting thermal energy into mechanical energy. How does it work? First, push the bird's head into a cup filled with water. The wet head of the bird cools down by evaporation - it condenses with the liquid vapors in the head, which creates a negative pressure. The fluid in the body is warmer so rises at higher pressure and rises in the tube to fill the lower pressure of the head. If it tilts forward, it returns the liquid and the cycle repeats. This process works much slower on very humid days where the temperatures of the head and body part are closer together. The process continues forever when the water is refilled. The classical scientific marvel; As soon as the bird starts drinking, it never stops!