There Is No Free Launch
So some guy is tinkering with magnetic motor design, when suddenly his magnets go flying everywhere around his workshop. He thereupon concludes that he’s invented a perpetual motion machine.
First…let’s review: The three laws of thermodynamics are:
- The total energy of a closed system neither increases nor decreases.
- The entropy of that system always increases.
- The temperature of that system cannot ever reach absolute zero, because entropy cannot decrease.
That last one is a little tricky, but visualize it as, the heat has to go somewhere and it can’t go from a colder body to a hotter body.
Anyway… No:
‘Holy crap, this is really scary,’ inventor says of strange phenomenon
It all began back in 1985, when Thane Heins, having studied electronics at Heritage College in Gatineau, Quebec, started thinking about how magnets could be used to improve power generators.
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Heins tinkered away, making what seemed like good progress, until one day in early 2006 he stumbled on to something strange. As part of a test, he had connected the driveshaft of an electric motor to a steel rotor with small round magnets lining its outer edges. The idea was that as the rotor spun, the magnets would pass by a wire coil placed just in front of them to generate electrical energy – in other words, it would operate like a simple generator.
The voltage was there, but to get current he had to attach an electrical load to the coil – like a light bulb – or simply overload it, which would cause it to slow down and eventually stop. Heins did the latter, but instead of stopping, the rotor started to rapidly accelerate.
"The magnets started flying off and hitting the wall, and I had to duck for cover," says Heins, surprised because he was using a weak motor. "It was like, holy crap, this is really scary."
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Days later, Heins realized what had happened…
Uh, oh…
…The steel rotor and driveshaft had conducted the magnetic resistance away from the coil and back into the heart of the electric motor. Since such motors work on the principle of converting electrical energy into motion by creating rotating magnetic fields, he figured the Back EMF was boosting those fields, causing acceleration.
But how could this be? It would create a positive feedback loop. As the motor accelerated faster it would create a larger electromagnetic field on the generator coil, causing the motor to go faster, and so on and so on. Heins confirmed his theory by replacing part of the driveshaft with plastic pipe that wouldn’t conduct the magnetic field. There was no acceleration.
"What I can say with full confidence is that our system violates the law of conservation of energy," he says.
Ummm, probably…not. At a guess, the current he was trying to overload the rotor with shorted back into the motor causing it to spin faster. The plastic pipe after all, could not conduct electricity either. But I’ll leave it to the engineers to explain some day, if this guy ever tries to sell his idea to investors. Look…the fact is that people have been trying to invent perpetual motion machines for millennia and the reason why they never work is because the very fabric of this universe just doesn’t function that way.
There’s another way of expressing the three laws:
- You can’t win.
- You can’t break even.
- You can’t leave the game.
I’ve always found it more then a little amusing, that at the heart of Ayn Rand’s Atlas Shrugged, there is a perpetual motion machine. It’s really amazing how often the pull-yourself-up-by-the-bootstraps free-the-marketplace right tries to get its free lunch.