The magic drinking bird bobs up and down like it is drinking from a glass. Once it starts it does not stop! This is a longtime favorite for millions of people around the globe.it is sometimes considered a perpetual motion device. The dippy bird (also called the drinking bird or the dunking bird) is a popular novelty item or toy in the united states and other countries. Almost everyone remembers this hard to find educational toy with at least a twinge of nostalgia. The drinking bird is back, disguised as a great demonstration of thermodynamics. A dippy bird has the following parts: Two equal-sized, hollow glass bulbs a long glass tube that connects the bulbs fuzzy, water-absorbent material covering the head two plastic legs with a pivot connection To operate the dippy bird, you get its head wet. As the water evaporates, fluid moves up into the head, causing the bird to become top-heavy and dip forward. Once the bird dips forward, fluid moves back into the abdomen, causing the bird to become bottom-heavy and tip up. Here is how a dippy bird works: When water evaporates from the fuzz on the dippy bird's head, the head is cooled. decreasing the vapor pressure in the head relative to the vapor pressure in the abdomen. The greater vapor pressure in the abdomen forces fluid up through the neck and into the head. As fluid enters the head, it makes the dippy bird top-heavy. The bird tips. Liquid travels to the head. The bottom of the tube is no longer submerged in liquid. Vapor bubbles travel through the tube and into the head. Liquid drains from the head, displaced by the bubbles. Fluid drains back into the abdomen, making the bird bottom-heavy. The bird tips back up. If the bird dips into a cup of water, the fuzzy material absorbs water again and the cycle starts over. If you hold a dippy bird upright in your hand, touching the abdomen, the following happens:
