Drinking Bird

Description

The Science of the Drinking Bird
The infamous Drinking Bird has been popular among children and adults for years. Once Drinking Bird's head is dunked in water, it will begin bobbing back and forth taking "drinks" with every bob.
Drinking Bird works using properties of thermodynamics, converting thermal energy into mechanical energy. The head and lower body of the bird are hollow glass chambers that are connected by a glass pipe. The pipe dips into the liquid (methylene chloride) in the lower body allowing the liquid to move up the pipe when the temperature of the head is slightly cooler.
The head is coated with red felt that absorbs water with every drink. Evaporation, aided by the swinging motion, reduces the temperature of the head. The vapor from the liquid will subsequently condense in the head. This makes the pressure in the head slightly lower than in the body, and the liquid is pulled up the pipe. The bird's center of gravity is altered as the liquid rises causing it to begin tilting toward the water and the bird takes a drink.
As the drinking bird tilts over, the liquid is eventually removed from the lower body and the lower portion of the pipe. The vapor above the liquid then rushes up the pipe which equalizes the pressure in the head and body. With this, the center of gravity returns to the lower body and with one swift motion, the bird swings back up away from the water.
The Drinking Bird is So Popular, We've Made it Our (Un)Official Mascot
In the real world, the Drinking Bird comes wearing a blue hat and red feet. The liquid comes in red or blue. *Caution: If broken, dye will stain!
You can buy your very own, real world working drinking Bird from Edmund Scientific @ scientificsonline.com
Please note this product is not a toy and is not intended for use by children under age 8. Contains methylene chloride and may stain clothing and other surfaces. Do not swallow liquid or allow to come in contact with eyes or skin. Non-flammable. Keep away from flame or other heat sources.