Properties of the magnet and the energy of the magnetic field
To such an object as a magnet, all have long been accustomed to. We do not see anything special in it. Associated with us, he usually with lessons in physics or demonstration in the form of focal points of the properties of a magnet for preschoolers. And rarely anyone thinks how many magnets surround us in everyday life. In any apartment there are dozens. A magnet is present in the device of each speaker, tape recorder, electric shaver, clock. Even a bank with nails is one.
We - people - are no exception. Thanks to the biocurrents in the body around us, there is an invisible pattern of its lines of force. A huge magnet is the planet Earth. And even more grandiose is the plasma ball of the sun. The dimensions of galaxies and nebulae incomprehensible to the human mind rarely allow the thought that all these are also magnets.
Modern science requires the creation of newlarge and heavy-duty magnets, the fields of application of which are associated with thermonuclear fusion, the generation of electric energy, acceleration in synchrotrons of charged particles, the rise of sunken ships. To create a superstrong field using the magnetic properties of a magnet is one of the tasks of modern physics.
Let's clarify concepts
A magnetic field is the force acting onpossessing the charge of the body, are in motion. It "does not work" with fixed objects (or devoid of charge) and serves as one of the forms of an electromagnetic field that exists as a more general concept.
If the bodies can create around themselves a magnetic field and themselves experience the power of its impact, they are called magnets. That is, these items are magnetized (they have a corresponding moment).
Different materials react differently to the externalfield. Weakening its action within themselves are called paramagnets, amplifying - diamagnetics. Individual materials have the property of a thousandfold increase in the external magnetic field. These are ferromagnets (cobalt, nickel with iron, gadolinium, and also compounds and alloys of these metals). Those of them, which, after being hit by a strong external field, themselves acquire magnetic properties, are called magnetically hard. Others, capable of behaving like magnets only under the direct impact of the field and ceasing to be so with its disappearance, are magnetically soft.
A little bit of history
By studying the properties of permanent magnets, peopleare engaged from very, very old times. It is mentioned in the writings of scholars of ancient Greece even 600 years before our era. Natural (natural origin) magnets can be found in deposits of magnetic ore. The most famous of the large natural magnets is stored at the University of Tartu. He weighs 13 kilograms, and the cargo, which can be raised with his help, is 40 kg.
Mankind has learned to create artificialMagnets using various ferromagnets. The value of powder (from cobalt, iron, etc.) is the ability to hold a weight of 5000 times its own weight. Artificial specimens can be permanent (obtained from magnetically hard materials) or electromagnets having a core, the material of which is soft magnetic iron. The voltage field in them arises due to the passage of an electric current through the winding wires, which is surrounded by a core.
The first serious book containing attemptsscientific study of the properties of the magnet, - the work of the London doctor Hilbert, published in 1600. This work contains all the information available at that time concerning magnetism and electricity, as well as authorial experiments.
Any of the existing phenomena a person tries to adapt to practical life. Of course, the magnet was no exception.
How magnets are used
What properties of the magnet did humanity take onArmament? Its scope is so wide that we can only briefly touch upon the main, most well-known devices and areas of application of this remarkable subject.
Compass is a well-known instrument fordetermination of directions on the ground. Thanks to him, they lay the ways of air and sea vessels, ground transportation, the purpose of pedestrian traffic. These devices can be magnetic (arrow type), used by tourists and topographers, or non-magnetic (radio and hydraulic compasses).
The first compasses of natural magnets weremade in the XI century and used in navigation. Their action is based on free rotation in the horizontal plane of a long needle made of magnetic material balanced on the axis. One end of it always faces the south, the other - to the north. Thus, it is always possible to accurately know the main directions concerning the sides of the world.
Areas where the properties of the magnet found the mainapplication - radio and electrical engineering, instrument making, automatics and telemechanics. From ferromagnetic materials, relays, magnetic cores, etc. are obtained. In 1820, the property of a conductor with a current was detected to act on the arrow of the magnet, forcing it to turn. At the same time, another discovery was made: a pair of parallel conductors through which a current of one direction passes through possess the property of mutual attraction.
Thanks to this, it was assumed thatbecause of the properties of the magnet. All such phenomena arise in connection with currents, including circulating inside magnetic materials. Modern ideas in science completely coincide with this assumption.
About engines and generators
Based on it, many varieties have been createdelectric motors and electric generators, that is, machines of rotational type, whose operation principle is based on the conversion of mechanical energy into electrical energy (we are talking about generators) or electric to mechanical (about engines). Any generator operates on the principle of electromagnetic induction, that is EMF (electromotive force) occurs in a wire that moves in a magnetic field. The electric motor operates on the basis of the phenomenon of the appearance of a force in a wire with a current placed in a transverse field.
Using the strength of the field-current interaction,which passes through the windings of the winding of their moving parts, devices called magnetoelectric devices operate. As the new powerful electric motor of an alternating current having two windings, the induction counter of the electric power acts. The conductive disk located between the windings is subject to rotation by a torque, the force of which is proportional to the power consumed.
And in everyday life?
Equipped with a miniature electric batteryThe wristwatch is familiar to everyone. Their arrangement through the use of a pair of magnets, a pair of inductance coils and a transistor is much simpler in terms of the number of available parts than a mechanical clock.
More and more locks are usedelectromagnetic type or cylinder locks, which are equipped with magnetic elements. In them, both the key and the lock are equipped with a code set. When the correct key is locked into the hole, the internal elements of the magnetic lock are attracted to the desired position, which allows it to be opened.
The action of magnets is based on the devicedynamometers and galvanometer (a highly sensitive device that measures weak currents). The properties of the magnet have found application in the production of abrasives. So called acute small and very hard particles, which are needed for mechanical processing (grinding, polishing, stripping) of a variety of objects and materials. In production, the necessary ferrosilicon in the mixture partly settles on the bottom of the furnaces, is partially incorporated into the abrasive. To remove it from there and require magnets.
Science and communication
Due to the magnetic properties of substances, science hasthe ability to study the structure of a variety of bodies. One can only mention magnetochemistry or magnetic flaw detection (a method for detecting defects by studying the distortion of a magnetic field in certain areas of products).
They are also used in the production of machineryultra-high frequency range, radio communication systems (military and commercial lines), heat treatment, both at home and in the food industry (everyone is familiar with microwave ovens). It is practically impossible within the framework of one article to enumerate all those complex technical devices and applications where the magnetic properties of substances are used today.
Scope of Medicine
The sphere of diagnostics andmedical therapy. Thanks to X-ray-generating electron linear accelerators, tumor therapy is performed, proton beams are generated in cyclotrons or synchrotrons, which have advantages over x-rays in the local direction and are more effective in treating eye and brain tumors.
As for biological science, even beforethe middle of the last century, the vital functions of the organism were not associated with the existence of magnetic fields. Scientific literature was occasionally replenished with single reports about one or another of their medical effects. But since the sixties, an avalanche of publications on the biological properties of the magnet began to flow.
Earlier and now
However, attempts to treat people were madealchemists in the 16th century. There have been many successful attempts to cure toothache, nervous disorders, insomnia and a variety of internal organs. It seems that in medicine, the magnet found its use no later than in navigation.
The last half a century, magneticbracelets, popular among patients with impaired blood pressure. Scientists have seriously believed in the ability of a magnet to increase the resistance of the human body. With the help of electromagnetic instruments have learned to measure the velocity of the blood stream, take samples or enter the necessary medications from the capsules.
Magnet removes the small ones caught in the eyemetal particles. Its operation is based on the work of electric sensors (anyone familiar with the procedure for removing the electrocardiogram). In our time, the cooperation of physicists with biologists to study the deep mechanisms of the effect on the human body of the magnetic field is becoming ever closer and necessary.
Neodymium magnet: properties and applications
Neodymium magnets are considered to possessmaximum impact on human health. They consist of neodymium, iron and boron. The chemical formula is NdFeB. The main advantage of such a magnet is the strong effect of its field at a relatively small size. Thus, the weight of a magnet with a force of 200 gauss is about 1 g. For comparison, an iron magnet equal in strength to it has a weight that is about 10 times larger.
Another undoubted advantage of these magnets is good stability and the ability to preserve the necessary qualities for hundreds of years. Throughout the century, the magnet loses its properties by only 1%.
How exactly are treated with a neodymium magnet?
With its help improve blood circulation, stabilize blood pressure, fight with migraine.
The properties of neodymium magnets began to be usedfor treatment about 2000 years ago. Mentions about this kind of therapy are found in the manuscripts of Ancient China. Treated then by applying magnetized stones to the human body.
Therapy also existed in the form of attaching them to thebody. Legend claims that Cleopatra was obliged to always wear a magnetic bandage on her head with excellent health and unearthly beauty. In the Xth century, Persian scientists described in detail the beneficial effects of the properties of neodymium magnets on the human body in the event of the elimination of inflammation and muscle spasms. According to the surviving evidence of the time, one can judge their use to increase muscle strength, bone tissue strength and reduce pain in the joints.
From all the ailments ...
Evidence of the effectiveness of such an impactwere published in 1530 by the famous doctor from Switzerland Paracelsus. In his writings, the doctor described the magical properties of a magnet that can stimulate the strength of the body and cause self-healing. A huge number of diseases in those days began to overcome, using a magnet.
Self-treatment withthe help of this money in the United States in the post-war years (1861-1865), when drugs were categorically lacking. They used it both as a medicine and as an anesthetic.
Since the XX century, the healing properties of a magnetreceived a scientific justification. In 1976, the Japanese doctor Nikagawa introduced the concept of a deficit of magnetic field. Studies have established its exact symptoms. They are included in weakness, fatigue, reduced efficiency and disturbances in the process of sleep. There are also migraines, joint and vertebral pains, malfunctions with the digestive and cardiovascular systems in the form of hypotension or hypertension. Concerning the syndrome and the field of gynecology, and skin changes. With the use of magnetotherapy, these states can be successfully normalized.
Science does not stand still
Scientists continue to experiment with magneticfields. Experiments are conducted both on animals and birds, and on bacteria. The conditions of the weakened magnetic field reduce the success of metabolic processes in experimental birds and mice, the bacteria abruptly stop multiplying. With prolonged deficit of the field, living tissues undergo irreversible changes.
It is for the fight against all such phenomena andMagnetotherapy as such is applied by numerous negative consequences caused by them. It seems that at the present time all the useful properties of magnets have not yet been studied to the proper degree. Ahead of the doctors a lot of interesting discoveries and new developments.