TWO PERPETUAL MOTION MACHINES
The perpetual motion machine is a utopian dream. Like other utopias, it attracts its share of cranks. Fortunately, in contrast to many social utopians of the past (and, unfortunately, present), these tend not to be dangerous and do not usually kill for an idea. Common to all utopias is an attempt to break a law—be it the law of conservation of energy, a law of economics, a law of human psychology, or a law of society.
The inventor of a perpetual motion engine must have limitless intelligence to rise to an infinitely difficult task of inventing the impossible. Attempted inventors of a perpetual motion machine include some very smart people, but few wise ones.
The two machines proposed here are puzzles, each asking to uncover a hidden flaw.1
1 In physics, debunking false theories became a safe activity soon after Galileo. In economics things took longer in some countries. A person I knew was sentenced to 12 years of hard labor in the former Soviet Union (around 1947) for wondering aloud in an economics class whether the profit motive is a necessary ingredient for a well-functioning economy.