Drinking Bird: Effect of Water (Condensation/Cooling)

Evaporating water can cool the head of a novelty store drinking bird, causing it to tip over and drink.

A novelty store "Drinking Bird" repeatedly dips is beak into a beaker of water and then bobs back to an upright position. Visible movement of a liquid in the bird's body accompanies the bobbing; the movement is caused by changing vapor pressure of the liquid due to different temperatures at the bird's head and the bird's body. Using a heat lamp on the head does not cause bobbing, but using a heat lamp on the body does cause bobbing.

  • Design and Demonstration
    • David Whisnant Wofford College, Spartanburg SC 29303
  • Video
    • Jerrold J. Jacobsen University of Wisconsin - Madison, Madison, WI 53706