Once we understood electromagnetism, countless possibilities opened up before our eyes. The movement of a magnet induces an electric current, and an electric current induces a magnetic field. Using these principles, we devised the alternator, an ingenious device that converts the movement of magnets into an alternating electric current. This invention has become an essential component of cars, planes and other vehicles, as well as, of power plants, where the energy of nature is transformed into electricity for our own necessities.