You look at the price of gasoline and wish for a better way to fuel your car, or better yet, a way to create free fuel.
For centuries, inventors and schemers have tried to do that by contriving a perpetual motion machine. It would move forever with no external source of energy, according to the Massachusetts Institute of Technology. But, the school says the idea is considered so far-fetched that the American patent office requires a working model, and the British patent office refuses all applications on the idea.
