Happy 200th Birthday - Electric Motor

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Changed civilization. From IEEE Spectrum:

200 Years Ago, Faraday Invented the Electric Motor
In 1820, the Danish physicist Hans Christian Ørsted threw electromagnetic theory into a state of confusion. Natural philosophers of the day believed that electricity and magnetism were two distinct phenomena, but Ørsted suggested that the flow of electricity through a wire created a magnetic field around it. The French physicist André-Marie Ampère saw a demonstration of Ørsted's experiment in which an electric current deflected a magnetic needle, and he then developed a mathematical theory to explain the relationship.

English scientist Michael Faraday soon entered the fray, when Richard Phillips, editor of the Annals of Philosophy, asked him to write a historical account of electromagnetism, a field that was only about two years old and clearly in a state of flux.

A bit more backstory and then this:

On 3 September 1821, Faraday observed the circular rotation of a wire as it was attracted and repelled by magnetic poles. He sketched in his notebook a clockwise rotation around the south pole of the magnet, and the reverse around the north pole. "Very satisfactory," he wrote in his entry on the day's experiment, "but make more sensible apparatus."

The next day, he got it right. He took a deep glass vessel, secured a magnet upright in it with some wax, and then filled the vessel with mercury until the magnetic pole was just above the surface. He floated a stiff wire in the mercury and connected the apparatus to a battery. When a current ran through the circuit, it generated a circular magnetic field around the wire. As the current in the wire interacted with the permanent magnet fixed to the bottom of the dish, the wire rotated clockwise. On the other side of the apparatus, the wire was fixed and the magnet was allowed to move freely, which it did in a circle around the wire.

Of course, I am a big Nikola Tesla fan and we must not overlook his patents from 1988 for the first Practical electric motor. Some primitive direct current motors were built in the 1830's but Tesla was the first person to develop alternating current (single and polyphase current) motors.  These are the first practical substitute for steam.  The foundation of the Industrial Revolution.

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