You've seen that bird that constantly drinks, maybe only at Grandma's house, or at a local restaurant. It's pitched as a perpetual motion machine, but you know there's no such thing. How does it work? Bill Hammack, the Engineer Guy (previously at Neatorama) explains that toy that fascinated you as a kid.
The secret is in how the bird is built. The liquid inside it is not water, and the air inside it is not air at all -it's a vacuum! The mechanism of its movement is quite interesting. And there's an explanation of why the bird drinks whiskey faster than it drinks water, which has nothing to do with getting drunk. -via Boing Boing