Is it a puzzle or is it a magic trick? Impossible objects are difficult to classify. They really aren't mechanical because they don't move (usually) and you don't manipulate any of their parts to solve them. You just look at them and think. And they aren't really a magic trick. There's no performer, at least not when you're dealing with the object. But they have the same "how did they do that" quality that a magic trick has. The puzzle is to figure out how they were made.
One of the oldest forms of impossible object is the ship in a bottle. The late Harry Eng carried this to the extreme by putting all sorts of objects into bottles your would not expect to find there. Decks of cards, books, shoes, padlocks, huge Turk's head knots, tennis balls, baseballs, your name it! I met Harry in 1992 and became fascinated with his bottles. He encouraged me to give it a try. I did, and I now make impossible object bottles myself. Most people either love them or could care less, but you'll have to admit that they are pretty strange.
