# Back to Basics.

## Magnetic Windmills.

I've often said that I seldom see anything fundamentally new in the perpetual motion and over-unity field. So people send me things that might surprise me. Philip Stephens sent me this one, probably to tease me, and tease visitors to this museum. I found this little animation very interesting, even without any text explanation. I have to admit that it is original, and was new to me.

A verbal description, designed to be deceptive, might go like this:

The magnetic field lines of the large magnet have direction shown by the arrowheads. In accordance with convention, these go from the magnet's north pole to its south pole. Two field lines are shown. The two little colored wheels are like windmills with vanes made of some ferrous magnetic material, and the circulation of the field lines from N to S poles causes the vanes to turn.

Some pesky skeptic is sure to ask about the colored windmills. In the diagram they are shown schematic only. What are they made of? Are their vanes magnets, and if so why isn't their polarity indicated?

Irrelevant questions. It simply doesn't matter. So long as the vanes are made of ferrous metal (say soft iron), the magnetic field of the large magnet will induce magnetism in the vanes and they will behave as magnets. Even if the vanes were permanent magnets, their polarity wouldn't matter either.

Now we ask readers to explain, in detail, what is wrong with this idea. Why won't it keep the windmills spinning perpetually?

1. Magnetic field lines are not something "real" in space, but only a mathematical map of the direction of the force that would act on a magnetic pole if placed at each point in the field.

2. The arrowheads shown on the field lines only indicate direction, they don't, by themselves, represent motion of anything. The field of a stationary magnet is a static (stationary) field.

3. Field lines can be drawn through all points in space. The animation shows only one of the infinity of lines one could draw. The inventor has ignored the totality of field lines.

4. If one of the field lines did force the inner windmill vanes to move, then by the same "reasoning" if you drew the field lines that passed through the outer parts of the windmills, the windmills would turn the opposite way. The net result of all such field lines "acting" on the wheel would be zero. The diagram shows one of the windmills (in blue). If the inventor had drawn this picture, the plausibility of the whole idea would have collapsed. By focusing attention on one field line drawn in the diagram, the inventor has ignored all the others.

5. Any induced magnetism in the windmill vanes would be bipolar, creating effective N and S poles in the vanes, so the net force and torque on the vanes would be zero.

6. Those who know something about field theory also know that in any region of space where the electric current is zero the curl of a static magnetic field is zero. The little windmill is a "curl-meter" registering zero.

There's a fundamental misconception at work here. People see pictures of fields—gravitational, electric or magnetic, and simplistically think of the fields as representing something "circulating" along the field lines in the direction of the arrows. They picture fields as if they were diagrams of wind velocity—perhaps winds in the luminiferous ether. In fact this is one variety of pseudoscientific field theory that has persisted since the time of Newton. I have a half dozen kooky books proposing such theories.[1] Even Nicola Tesla seemed to assume such a model when he speculated that with gravity shields one could make a wheel turn perpetually. He seemed to be thinking of a gravity shield as "blocking the gravity wind", and preventing it from "pushing" on part of the wheel. Of course gravity shields are impossible, as is perpetual motion.

A rich branch of pseudoscience imagines gravity as a "wind" in space, usually a wind that is constantly blowing downward toward the center of the earth, pushing things downward so they fall to earth if unsupported. This of course, raises the tricky question of what happens to this wind at the center of the earth, and where did the wind originate "out there".

## Endnotes:

[1] See, for example, my list of pseudoscience books, Incredible Pseudoscience.

All material in this museum is © 2002, 2005, 2013 by Donald E. Simanek, with the exception of text and materials indicated as from other sources.