In 1821, a year after Hans Christian Ørsted discovered electromagnetism, the great scientific thinker Michael Faraday figured out how to turn it into motion, thus creating the world’s first motor. Though a primitive device that served no practical purpose, it was a great leap for humankind and led to the much more sophisticated motors of today.
Let’s take a closer look at the forces that make that wire turn.
For his motor, Faraday first created a circuit comprised of a wire, a battery and a dish of mercury (a very good conductor). The wire was arranged so that one end hung free in the mercury bath. When current ran through the circuit (its direction is marked by arrows in the tutorial, going from positive to negative), it generated a circular magnetic field around the wire (the phenomenon discovered by Ørsted). The wire’s magnetic field interacted with a second force built into the instrument, the magnetic field of a permanent magnet fixed to the center of the dish.
Click on the Field Lines Button to see the magnetic field lines of the compass and the wire. It should be apparent how these two forces interacted to create motion – and change the course of history!
Barlow’s Wheel, invented not long after Faraday’s simple apparatus, was the next in a long evolutionary line of electric motors.