Magnetic "perpetuum mobile"

Since ancient times, humanity has sought to create a variety of "perpetual motion machines". Numerous projects of "perpetual motion machines", which proved to be difficult to expose, are associated with magnets. For example, the magnetic "perpetuum mobile" of Pierre Perigrin de Maricour, who lived in the 13th century. He argued that if the magnetic stone is sharpened in the form of a regular ball and directed by poles precisely along the axis of the world, then such a ball will spin and it will rotate forever.

In the 17th century the magnetic perpetuum mobile was tried by the English bishop John Wilkens

In the 17th century the magnetic "perpetuum mobile" was tried by the English bishop John Wilkens. He even received an official confirmation of the "eternal engine" invented by him, but this did not work from it. John Wilkens believed that the steel ball, attracted by the magnet, rises along the upper inclined plane, but, not reaching the magnet, falls through the hole and rolls down the bottom tray. Rolling down, he again finds himself on his former path and so continues his movement forever. In fact, if the magnet was strong, then the ball did not fall into the hole, but jumped over it and stuck to the magnet. If the magnet was weak, then the ball stopped halfway on the bottom tray, or did not leave the bottom point at all.

But there are also real magnetic motors, which at first glance look like eternal.

If the iron is strongly heated, it completely stops attracting the magnet. Now the temperature at which iron, steel or alloys lose their magnetic properties is called the Curie point. This property made it possible to create a so-called magnetic mill. We will hang a wooden disk on a thread or put it on a steel needle like the arrow of a compass. Then stick a few knitting needles into it and place the pole of the strong magnet on the side. But this is not a magnetic "perpetuum mobile" - the mill will not rotate until we heat the neighboring magnet in the flame of the burner and with a slight push do not impart a rotation. The heated spoke is no longer attracted to the magnet, and the next one tends to it until it hits the flame of the burner. And while the heated knitting needle goes through a full circle, it will cool and re-attract the magnet.

On the one hand, what is not the magnetic "perpetuum mobile"? But, on the other hand, the energy of the burner goes to its rotation. Therefore, this engine is not eternal, but thermal, in principle the same as for cars and diesel locomotives.

Working on the same principle, the magnetic swing is easy to build on your own. A small iron object is suspended on the wire to the top of the rack of the swing. It is easiest to take a long piece of iron wire and roll its end into a small lump. Then on a small stand we put a magnet directed one pole to the side. We will move the stand with the magnet to the suspended iron lump, until it is attracted to the magnet. Now let's substitute under a swing an alcohol lamp or a candle so that a lump has appeared above the flame. After a while, having heated to the Curie point, it disappears from the magnet. Rocking in the air, he will cool again and again attracted to the pole of the magnet. Get an interesting swing, which will swing until we remove the burner.

Conventional iron has a sufficiently high Curie point: 753 0C, but now alloys are obtained for which the Curie point is not much higher than room temperature. Heated by solar heat, such material, especially painted in a dark color, is already non-magnetic. And in the shadow, the magnetic properties are restored, and the material can again be attracted. For example, for a gadolinium metal, the Curie point is only 20 0C. On this principle, for example, a magnetic "perpetuum mobile" is created, continuously pumping water in a hot desert. The sun provides it with its energy.

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