Drinking Bird

A classic novelty model that rocks back and forth so it seems to sip from a glass of water. Wetting the beak sets up a temperature difference between the liquid columns in the bird's body and head; this drives a continuous motion in which the bird dips its beak again and again until the glass is empty or the water is out of reach. In science and physics lessons it illustrates thermodynamic principles such as evaporation, pressure differences and energy conversion, giving a concrete way into heat, liquids and evaporation. It also works as a simple, intriguing demonstration of physics in action that sparks curiosity.