So You Want To Test Your Perpetual Motion Machine?

Steven Dutch, Natural and Applied Sciences, University of Wisconsin - Green Bay
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Frankly I was astonished when we didn't see a rash of perpetual motion machines appear after the first oil embargo of 1973. But they're starting to appear now. Since "perpetual motion" has a bit of a suspicious ring to it, some inventors are using the term "free energy" instead. Most people are savvy enough not to believe in perpetual motion but there are millions of people who believe it's possible to have free energy. (There is a legitimate use of the term "free energy" in chemistry - it has nothing at all to do with what we're discussing here.)

Some of the talk about "free energy" is based on weird notions of energy. It does not require energy for a magnet to stick to a refrigerator. It does not take energy for a table to keep a weight from falling to the floor.

Many of these inventors lament that they can't get scientists to test their devices. Well, always here to help, that's me. Here are three simple tests. In every case we assume your device puts out more energy than it uses - that's the definition of perpetual motion. So the device ought to be able to supply all the power it needs, plus have enough extra to run some kind of a load.

No, we're not the least bit interested in anything that would produce free energy if it weren't for friction, or that puts out excess energy if you don't count engineering losses, etc. A real energy source has to deal with friction and other losses, and if yours can't, it doesn't work. Period.

Test 1: The Loop

Simplicity itself. Hook the output of your device up to the input. You may need to use a startup source, but once the device is running, disconnect the startup source completely.

Test 2: Dual Engines

If you have two devices, hook the output of one to the input of the other and vice versa. Again, you may need to use a startup source, but once the device is running, disconnect the startup source completely.

The load is essential. We'd hate to have the current build up to catastrophic levels and burn out the motors.

Test 3: Dual Battery Sources

Here we have two battery banks. Use one bank to power the device and use the output to charge the other bank. A switching circuit switches the roles of the battery banks when the powering bank is depleted. We don't need a startup source here since we're hooked up to batteries all the time.

Circuits with significant capacitance or inductance can store a lot of energy, so getting Test 1 or Test 2 to work for a few seconds, or maybe even a few minutes, isn't sufficient. The initial energy would come from the power-up source and the devices would simply run off stored energy. 24 hours, now, that would be impressive.

Test 3 might run for some time depending on the load, the power needs of the device, and the power supplied by the batteries. A calibration run might use a battery bank to run the device plus the load, without recharging, until the batteries run down. If you can get 10 or 100 times as much life out of the batteries, you've got something.

For the real confirmation test, we'll put the setup in a locked room with a window and continuous video surveillance, if that's all right.


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Created 27 February, 2006;  Last Update 30 August, 2011

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