Electricity and Motion

Imagine this.  After spending the afternoon investigating magnets, coils of wire, and Faraday’s strange theories, you begin gathering your things.  Perhaps electricity and magnetism really are connected like Faraday thinks.  You are about to thank Faraday and leave when something catches your eye.  In the far corner of the laboratory, partially hidden behind a stack of notebooks and jars, you see a thin metal arm spinning, round and round.  You watch for a minute, and it continues spinning the whole time, never stopping.

“What is that?” you ask.

A smile spreads across Faraday’s face.  “Ah! You’ve noticed it.”

Dustin leans in for a closer look.  After a quick inspection, he says, “I don’t see anything moving it.  How is it doing that?”

“That is a motor,” Faraday says.

“A motor?” Dustin says.  “That doesn’t look like any motor I have ever seen.”

“This is the first motor,” Faraday says.

“You invented the first motor?” you ask, a little surprised.

“I did!  It’s an amazing machine,” Faraday responds.

You look back at the machine, quite impressed.

“How did you make it?”  Dustin asks.

“Do you remember the story of the compass needle I told you about?” Faraday asks.  “The one that moved when electricity flowed through the wire?”

You nod, and Faraday continues.

“I ran the same experiment as the one in that story.  I ran a wire by a compass and then directed electricity down the wire.  Sure enough, the compass needle twitched.  I began to imagine that the electricity running through the wire was making something like a whirlpool of magnetism, and that was catching the compass needle and moving it.”

“A whirlpool?” Dustin asks.  “Like the swirling water in a toilet?”  

Faraday looks at Dustin, a bit confused, and then looks at you.  “Do you understand what I mean?”

You assure him that you do know what a whirlpool is, and that he can continue with his story.

“Well, like I was saying, I started thinking that if that whirlpool was strong enough to move the compass needle, then maybe we could create a bigger whirlpool that could move something bigger than a compass needle.  And then I started wondering how I could build a machine that could harness the power of that whirlpool and do something with it.”  Faraday points to the motor spinning next to you.  “And that is what I came up with.”

Dustin nods.  “So it’s like a big toilet?”

Wishing to cover up whatever Dustin says, you jump in immediately with a question: “So electricity can make things move?”  

“That is what I discovered,” Faraday says.  “That motor is the proof.”

You think back to Franklin’s Leyden jars, Volta’s batteries, Faraday’s magnets.  The pieces might just fit together after all.

Faraday watches you, and then says, “You know, a discovery is only truly understood when you make it yourself.”  He reaches into a drawer and pulls out several objects and places them on the table in front of you.  “Before you leave,” he says, “why don’t you see if you can build a motor, too?”