As you know, the Earth, due to the prevailing world order, has a certain gravitational field, and the dream of man has always been to overcome it by any means. Magnetic levitation is a term more fantastic than referring to everyday reality.
Initially, it meant the hypothetical ability to overcome gravity in an unknown way and move people or objects through the air without auxiliary equipment. However, now the concept of "magnetic levitation" is already quite scientific.
Several innovative ideas are being developed at once, which are based on this phenomenon. And all of them promise great opportunities for versatile applications in the future. True, magnetic levitation will be carried out not by magical methods, but using very specific achievements of physics, namely the section that studies magnetic fields and everything connected with them.
Just a bit of theory
Among people far from science, there is an opinion that magnetic levitation is a guided flight of a magnet. In fact, under thisthe term implies overcoming the object of gravity with the help of a magnetic field. One of its characteristics is magnetic pressure, which is what is used to "fight" the earth's gravity.
To put it simply, when gravity pulls an object down, the magnetic pressure is directed in such a way that it pushes it back up. This is how the magnet levitates. The difficulty in implementing the theory is that the static field is unstable and does not focus at a given point, so it may not be able to effectively resist attraction. Therefore, auxiliary elements are required that will give the magnetic field dynamic stability, so that the levitation of the magnet is a regular phenomenon. Various methods are used as stabilizers for it. Most often - electric current through superconductors, but there are other developments in this area.
Technical levitation
Actually, the magnetic variety refers to the broader term for overcoming gravitational attraction. So, technical levitation: an overview of methods (very short).
We seem to have figured out a little with magnetic technology, but there is also an electric method. Unlike the first one, the second one can be used for manipulations with products made of various materials (in the first case, only magnetized ones), even dielectrics. Separate also electrostatic and electrodynamic levitation.
The ability of particles to move under the influence of light was predicted by Kepler. BUTthe existence of light pressure was proved by Lebedev. The movement of a particle in the direction of the light source (optical levitation) is called positive photophoresis, and in the opposite direction - negative.
Aerodynamic levitation, differing from optical, is quite widely applicable in today's technologies. By the way, the "pillow" is one of its varieties. The simplest air cushion is obtained very easily - many holes are drilled in the carrier substrate and compressed air is blown through them. In this case, the air lift balances the mass of the object, and it floats in the air.
The last method known to science at the moment is levitation using acoustic waves.
What are examples of magnetic levitation?
Science fiction dreamed of portable devices the size of a backpack, which could "levitate" a person in the direction he needed with considerable speed. Science has so far taken a different path, more practical and feasible - a train was created that moves using magnetic levitation.
History of super trains
For the first time, the idea of a composition using a linear motor was submitted (and even patented) by the German engineer-inventor Alfred Zane. And that was in 1902. After this, the development of an electromagnetic suspension and a train equipped with it appeared with enviable regularity: in 1906, Franklin Scott Smith proposed another prototype, between 1937 and 1941. a number of patents on the same topic were received by Hermann Kemper, anda little later, Briton Eric Lazethwaite created a life-size working prototype of the engine. In the 60s, he also participated in the development of the Tracked Hovercraft, which was supposed to become the fastest train, but did not, because the project was closed due to insufficient funding in 1973.
Only six years later, again in Germany, a maglev train was built and licensed for passenger transport. The test track laid in Hamburg was less than a kilometer long, but the idea itself inspired society so much that the train functioned even after the exhibition closed, having managed to transport 50,000 people in three months. Its speed, by modern standards, was not so great - only 75 km / h.
Not an exhibition, but a commercial maglev (so they called the train using a magnet), ran between Birmingham airport and the railway station since 1984, and lasted 11 years in his post. The length of the track was even shorter, only 600 m, and the train rose 1.5 cm above the track.
Japanese
In the future, the excitement about maglev trains in Europe subsided. But by the end of the 90s, such a high-tech country as Japan became actively interested in them. Several fairly long routes have already been laid on its territory, along which maglevs fly, using such a phenomenon as magnetic levitation. The same country also owns the speed records set by these trains. The last one showed a speed limit of more than 550 km/h.
Furtherprospects for use
On the one hand, maglevs are attractive because of their ability to move quickly: according to theorists, they can be accelerated up to 1,000 kilometers per hour in the near future. After all, they are driven by magnetic levitation, and only air resistance slows them down. Therefore, giving the maximum aerodynamic outlines to the composition greatly reduces its impact. In addition, due to the fact that they do not touch the rails, the wear of such trains is extremely slow, which is very cost-effective.
Another plus is the reduced noise effect: maglev trains move almost silently compared to conventional trains. The bonus is also the use of electricity in them, which reduces the harmful effects on nature and the atmosphere. In addition, the maglev train is capable of climbing steeper slopes, eliminating the need to lay the track around hills and slopes.
Energy applications
No less interesting practical direction can be considered the widespread use of magnetic bearings in key components of mechanisms. Their installation solves a serious problem of wear and tear of the source material.
As you know, classic bearings wear out quite quickly - they constantly experience high mechanical loads. In some areas, the need to replace these parts means not only additional costs, but also a high risk for the people who service the mechanism. Magnetic bearings remain operational many times longer, so their use is highly advisable forany extreme conditions. Particularly in nuclear power, wind technology, or industries with extremely low/high temperatures.
Aircraft
In the problem of how to implement magnetic levitation, a reasonable question arises: when, finally, will a full-fledged aircraft, in which magnetic levitation will be used, be manufactured and presented to progressive mankind? After all, there is indirect evidence that such "UFOs" existed. Take, for example, the Indian "vimanas" of the most ancient era or Hitler's "discoplanes", which are already closer to us in terms of time, using, among other things, electromagnetic methods of organizing lift. Approximate drawings and even photos of working models have been preserved. The question remains open: how to bring all these ideas to life? But things are not going further than not very viable prototypes for modern inventors. Or maybe this is still too secret information?
