Powerful magnets. The largest magnets

The largest magnet

In our world there are a lot of different things, the origin of which is completely scientific explanation. But despite this, they still cause a lot of controversy and enormous interest among many people. One of these pressing issues is the use of the most powerful magnets. There are a lot of magnets in the world, each of which is unique in its own way. But which one is the most powerful?

An unusual and powerful star magnet

Magnetic neutron star, called Gamma Relay 1806-20, is the most powerful magnetic object in the Universe. It suppresses enough magnetic force to slow a locomotive from a distance of a quarter of a million miles (the path from the Earth to the Moon).

On this moment Only ten such unusual objects have been discovered. With a magnetic field of 100 billion Tesla, the star eclipses the Earth. The Earth's magnetic field is 0.00005 tesla. It is unlikely that any man-made device will ever approach the power of this most powerful magnet from space.

The most powerful American magnet

Most powerful magnet, developed in Florida, represents a technical milestone in construction order space station and is an engineering feat. Researchers from the state of Florida (USA) are currently recording using a hybrid magnetic system introduced in the nineties. The powerful magnetic system, weighing 35 tons, has a magnetic field a million times greater than the Earth's magnetic field.

Unusual magnet or giant horseshoe

Hearing this name, a huge horseshoe immediately comes to mind. However, in in this case We don’t think so at all. It's about about the universal magnetic system from Florida. It consists of two huge curved magnets working together. Outer layer- this is the most powerful magnet with supercooling and superconductivity. It has no equal among similar devices ever created by man. The magnet is constantly cooled with superfluid helium to temperatures close to absolute zero. At the center of the system is a huge resistive magnet.

Some interesting moments from the tests

This huge resistor magnet is a device located at the center of the complex fixture. But despite its size, this super magnet is rarely used. The thing is that a very small test site was allocated for its testing. Because of this, the test objects are tiny and no larger than the tip of a regular pencil.

Moreover, during testing, the test sample must be cooled to a certain temperature. To do this, it is lowered into a special cylindrical reservoir with coolant.

Application of magnet in medicine

Any most powerful magnet can easily find its application in medicine. The use of these devices allows us to solve the problem of modernizing modern medical equipment.

For example, the largest magnet used for tomography is located in Florida. This 24-ton giant allows you to study the brain and spinal cord, revealing not only various diseases, but also the injuries the patient once received. The higher the magnetic field, the more accurate the results. Brain University believes the use of super-powerful magnets will help in research into brain and spinal cord injuries.

One of the projects plans to use functional imaging of living cells using a powerful magnet. During the experiment, scientists will learn how much brain tissue is damaged over time and how medicines may influence this.

MRI technology, which also includes magnets, uses a powerful magnetic field to align the cell nuclei of the body. In this case, one magnet is stationary, while the other rotates the nuclei and generates a signal. This is what computers read. They then process and convert the received signal into a three-dimensional visual image.

Do magnets affect humans?

Expanding medical use magnets raises an obvious question: are magnetic fields good or bad for human body? IN last years there has been much debate about the consequences of living close high voltage lines power transmission

But since the fields fall quite quickly, someone living just 50 feet from a power line would likely experience no more than two milligauss. In the latest study, there was no evidence to suggest that this level of exposure would have harmful effects on the body.

Neodymium magnets: what and how

These magnets are very powerful. They are strong and fairly safe, but heavy. Some of them can weigh hundreds of kilograms. These are unique pieces of magnetic alloy endowed with super-powerful adhesive force. Such devices can be encased in an additional steel casing, which will increase their weight and grip. They may also be devoid of such an additional shell. Accordingly, they will have less grip and weight.

Thanks to the power and strength of such devices, it became possible to lift up loads weighing up to 1000 kg.

What are search magnets used for?

The most powerful search magnets are small devices used to search for valuables. metal objects and objects. Such finds always have historical meaning and important for various kinds research companies, archaeological societies and other antique enthusiasts.

As a rule, they consist of powerful neodymium magnets, rubber and steel cases, and other components. The dimensions of the devices are quite compact, so they can be carried in your hands. They can be used not only on the surface, but also in wells, swamps, and rivers. They can be double-sided or single-sided, and also differ in their weight and power.

Powerful and strong neodymium magnets

There are permanent magnets that can have the same attractive strength as the most powerful neodymium magnets. They are called AlNiCo magnets. Such devices are usually created on the basis of aluminum, cobalt and nickel. For larger sizes, a casting and its complex shapes are used.

According to experts, these types of magnets have excellent thermal characteristics. Thanks to this, they have found their application in the production of automotive ABS braking systems, products with reed switches (for example, sensors fuel supply) and guitar pickups.

As you can see, magnets are an important part of our lives. They are used in various fields our activities and for different purposes.

It was our compatriots who set a Guinness record in the late 50s of the twentieth century, which has not yet been broken in any country. The magnet was created in the Moscow region (Dubna), at the Joint Institute for Nuclear Research.

Why did Soviet physicists need such a giant? This magnet became the “heart” of a huge installation, which became known throughout the world as the synchrophasotron. It was intended to explore the microworld. His “father” is the famous physicist Vladimir Veksler.

Vladimir Veksler

Synchrophasotron – special kind charged particle accelerator. The latter are accelerated in the installation to ultra-high speeds and, as a consequence, to high energies. By the way they interact with other atomic particles, physicists form an idea of ​​the properties and structure of matter. One of the most important parameters of a synchrophasotron installation is the intensity of the accelerated particle beam.

Synchrophasotron

Why does the magnet have such impressive dimensions? The fact is that the particle beam in the synchrophasotron is weakly focused. It is located in a vacuum chamber whose dimensions are two meters by forty centimeters. Therefore, to keep the particles inside the ring, an unusually strong and powerful magnetic field is needed. This was provided by the giant Dubna magnet.

The idea of ​​Soviet scientists was picked up all over the world. After the launch of the first synchrophasotron, similar projects appeared in the USA and Switzerland. The accelerators built in recent years have been significantly modernized, but are still based on Wechsler’s principles.

What is the fate of the giant magnet? It has been partially dismantled along with the accelerator. It is simply impossible to transport him from the United Institute. For more than half a century, the weight of the magnet deformed the building. Therefore, if you start dismantling the structure for further transportation, the institute will simply collapse. The plan is to leave the magnet in place and turn it into a museum piece. As an option, joint construction with French scientists of a new accelerator based on the old one is also being considered. Several modern magnets will be placed inside the giant magnet, and the “elder” will serve as a biological shield for them.

Currently, the accelerator is conducting research papers By:

Searching for new methods of energy production;

Opening up innovative opportunities for nuclear waste disposal;

Achieving resistance of microcircuits to heavy ions.

As already mentioned, to date no one has managed to break the record of Soviet scientists. But there are attempts. So, the leadership of the main nuclear center India has made a statement that it is going to install the most powerful and largest permanent magnet in the southeast of the country, in the province of Tamil Nadu. It is expected to weigh more than 50,000 tons. They plan to use the giant in an underground neutrino observatory. Its construction was approved by the Indian authorities back in 2010. It is here that Indian scientists are going to thoroughly study the neutrinos “mined” during experiments at the accelerator. Of particular interest to the project developers is the ability of neutrinos to change from one form to another.

In the meantime, the Indian observatory exists only on paper, the Dubna magnet firmly occupies a well-deserved place in the Guinness Book of Records.

Also in Ancient China drew attention to the property of some metals to attract. This physical phenomenon is called magnetism, and materials that have this ability are called magnets. Now this property is actively used in radio electronics and industry, and especially powerful magnets are used, among other things, for lifting and transporting large volumes of metal. The properties of these materials are also used in everyday life - many people know magnetic cards and letters for teaching children. What kind of magnets there are, where they are used, what neodymium is, this text will tell you about it.

Types of magnets

IN modern world They are classified into three main categories based on the type of magnetic field they create:

• permanent, consisting of natural material possessing these physical properties, for example, neodymium;
• temporary, possessing these properties while in the field of action of a magnetic field;
• Electromagnets are coils of wire on a core that create an electromagnetic field when energy passes through the conductor.

In turn, the most common permanent magnets are divided into five main classes, according to their chemical composition:

• ferromagnets based on iron and its alloys with barium and strontium;
• neodymium magnets containing rare earth metal neodymium, alloyed with iron and boron (Nd-Fe-B, NdFeB, NIB);
• samarium-cobalt alloys, which have magnetic characteristics comparable to neodymium, but at the same time a wider temperature range of application (SmCo);
• Alnico alloy, also known as UNDC, this alloy has a high corrosion resistance and high temperature limit;
• magnetoplasts, which are a mixture of a magnetic alloy with a binder, this allows you to create products of various shapes and sizes.

Alloys of magnetic metals are brittle and quite cheap products with average qualities. It is usually an alloy of iron oxide with strontium and barium ferrites. Temperature Range stable operation magnet not higher than 250-270°C. Specifications:

• coercive force – about 200 kA/m;
• residual induction – up to 0.4 Tesla;
• average service life is 20-30 years.

What are neodymium magnets

These are the most powerful of the permanent ones, but at the same time they are quite fragile and not resistant to corrosion; these alloys are based on the rare earth mineral - neodymium. This is the most strong magnet from the permanent ones.

Characteristics:

• coercive force – about 1000 kA/m;
• residual induction – up to 1.1 Tesla;
• average service life is up to 50 years.

Their use is limited only by the low limit of the temperature range; for the most heat-resistant brands of neodymium magnet it is 140°C, while less resistant ones are destroyed at temperatures above 80 degrees.

Samarium-cobalt alloys

Possessing high technical characteristics, but at the same time very expensive alloys.

Characteristics:

• coercive force – about 700 kA/m;
• residual induction – up to 0.8-1.0 Tesla;
• average service life is 15-20 years.

They are used for difficult conditions works: high temperatures, aggressive environments and heavy load. Due to comparatively high cost their use is somewhat limited.

Alnico

Powder alloy made of cobalt (37-40%) with the addition of aluminum and nickel also has good performance characteristics, in addition, the ability to maintain their magnetic properties at temperatures up to 550°C. Their technical characteristics are lower than those of ferromagnetic alloys and are:

• coercive force – about 50 kA/m;
• residual induction – up to 0.7 Tesla;
• average service life is 10-20 years.

But, despite this, it is this alloy that is most interesting for use in the scientific field. In addition, the addition of titanium and niobium to the alloy helps to increase the coercive force of the alloy to 145-150 kA/m.

Magnetic plastics

They are used mainly in everyday life for making magnetic cards, calendars and other small things; the characteristics of the magnetic field decrease slightly due to the lower concentration of the magnetic composition.

These are the main types permanent magnets. The principle of operation and application of an electromagnet differs somewhat from such alloys.

Interesting. Neodymium magnets are used almost everywhere, including in design to create floating structures, and in culture for the same purposes.

Electromagnet and demagnetizer

If an electromagnet creates a field when passing through the turns of the winding of electricity, then the demagnetizer, on the contrary, removes the residual magnetic field. This effect can be used in for different purposes. For example, what can be done with a demagnetizer? Previously, the demagnetizer was used to demagnetize the playback heads of tape recorders, television picture tubes and perform other similar functions. Today it is often used for somewhat illegal purposes, to demagnetize meters after using magnets on them. In addition, this device can and should be used to remove residual magnetic fields from instruments.

The demagnetizer usually consists of an ordinary coil, in other words, in terms of design, this device completely replicates an electromagnet. An alternating voltage is applied to the coil, after which the device from which we remove the residual field is removed from the demagnetizer's coverage area, after which it turns off

Important! Using a magnet to “twist” the meter is illegal and will result in a fine. Improper use of the demagnetizer can lead to complete demagnetization of the device and its failure.

Making your own magnet

To do this it is enough to find metal bar made of steel or other ferroalloy, you can use a composite transformer core, and then make a winding. Wind several turns of copper winding wire around the core. For safety, it is worth including a fuse in the circuit. How to make a powerful magnet? To do this, you need to increase the current strength in the winding; the higher it is, the greater the magnetic force of the device.

When the device is connected to the network and electricity is supplied to the winding, the device will attract metal, that is, in fact, it is a real electromagnet, albeit of a somewhat simplified design.

The largest magnet

Magnetic storms are usually not considered a formidable natural phenomenon, such as earthquakes, tsunamis, or typhoons. True, they disrupt radio communications in the high latitudes of the planet and make compass needles dance. Now these interferences are no longer scary. Long-distance communications are increasingly carried out via satellites, and with their help, navigators set the course for ships and aircraft.

It would seem that the vagaries of the magnetic field may no longer bother anyone. But it is now that some facts have given rise to fears that changes in the Earth’s magnetic field can cause catastrophes that will make the most formidable forces of nature pale in comparison!

One such field change is happening today... Since the German mathematician and physicist Carl Gauss first gave a mathematical description of the magnetic field, subsequent measurements - over 150 years to the present day - show that the Earth's magnetic field has been steadily weakening.

In this regard, the questions seem natural: will the magnetic field disappear completely, and how can this threaten earthlings?

Let us remember that our planet is constantly bombarded by cosmic particles, especially intensely by protons and electrons emitted by the Sun, the so-called solar wind. They rush past the Earth at an average speed of 400 km/s. The Earth's magnetosphere does not allow charged particles to reach the surface of the planet. She directs them to the poles, where they give birth to fantastic lights in the upper atmosphere. But if there is no magnetic field, if the flora and fauna are under such continuous fire, then we can assume that radiation damage to organisms will have a most disastrous effect on the fate of the entire biosphere.

To judge how real such a threat is, we need to remember how the Earth’s magnetic field arises and whether there are any unreliable links in this mechanism that can fail.

According to modern concepts, the core of our planet consists of a solid part and a liquid shell. Heated by the solid core and cooled by the mantle located above, the liquid substance of the core is drawn into the circulation, into convection, which breaks up into many separate circulating flows.

The same phenomenon is familiar to the Earth's oceans, when deep heat sources are close to the ocean floor, causing it to warm up. Then vertical currents arise in the water column. For example, such a current in the Pacific Ocean off the coast of Peru has been well studied. It carries a huge amount of nutrients from the depths to the surface of the water, making this area of ​​the ocean especially rich in fish...

The substance of the liquid part of the core is a melt with a high content of metals, and therefore it has good electrical conductivity. From the school course we know that if a conductor moves in a magnetic field, crossing its lines, then an electromotive force is excited in it.

A weak interplanetary magnetic field could initially interact with the melt flows. The current generated by this, in turn, created a powerful magnetic field that surrounded the planet's core in rings.

In the depths of the Earth, in principle, everything happens as in a self-excited dynamo, a schematic model of which is usually available in every school physics classroom. The difference is that instead of wires in the depths there are flows of liquid electrically conductive material. And, apparently, the analogy between the sections of the dynamo rotor and the convection flows of the melt in the depths is quite legitimate. The mechanism that creates the Earth's magnetic field is therefore called a hydromagnetic dynamo.

But the picture, of course, is more complicated: ring fields, otherwise called toroidal, do not reach the surface of the planet. Interacting with the same electrically conductive moving liquid mass, they generate another, external field, which we deal with on the surface of the Earth.

Our planet with its external magnetic field is usually schematically depicted as a symmetrically magnetized ball with two poles. In reality, the external field is not so ideal in shape. Symmetry is broken by many magnetic anomalies.

Some of them are very significant and are called continental. One such anomaly is located in Eastern Siberia, the other in South America. Such anomalies arise because the hydromagnetic dynamo in the bowels of the Earth is not “designed” as symmetrically as electrical machines built in a factory, where they ensure the coaxiality of the rotor and stator and carefully balance the rotors on special machines, ensuring that their centers of mass coincide (more precisely, the main central axis of inertia) with the axis of rotation. Both the power of matter flows and the temperature conditions on which the speed of their movement depends are far from the same in different zones of the earth’s interior, where the natural dynamo operates. Most likely, a deep dynamo can be compared to a machine in which sections in the rotor winding are of different thicknesses and the gap between the rotor and stator varies.

Anomalies of a smaller scale - regional and local - are explained by the peculiarities of the composition of the earth's crust - such as, for example, the Kursk magnetic anomaly, which arose due to giant deposits of iron ore.

In a word, the mechanism that generates the Earth’s magnetic field is stable, reliable, and it seems there are no parts in it that can suddenly fail. Moreover, according to Professor G. Zoffel of the University of Munich, the electrical conductivity of the liquid material in the depths is so great that if for some reason the hydromagnetic dynamo suddenly “turns off,” the magnetic forces on the surface of the planet will signal us about this only after many millennia.

But the “breakdown” of a natural mechanism is one thing, the gradual attenuation of its action, similar to the cold snaps that gave rise to glaciations of the planet, is another.

To analyze this circumstance, we will need a more detailed understanding of the behavior of the magnetic field: how and why it changes over time.

Any rock, any substance containing iron or other ferromagnetic element is always under the influence of the Earth's magnetic field. Elementary magnets in this material tend to orient themselves like a compass needle along the field lines.

However, if the material is heated, there will come a point when the thermal motion of the particles becomes so energetic that it destroys the magnetic order. Then, when our material cools, starting from a certain temperature (it is called the Curie point), the magnetic field will prevail over the forces of chaotic motion. The elementary magnets will again line up as the field tells them, and will remain in this position if the body is not heated again. The field appears to be “frozen” in the material.

This phenomenon allows us to confidently judge the past of the earth's magnetic field. Scientists are able to penetrate into such distant times when the solid crust was cooling on the young planet. Minerals preserved from that time tell about what the magnetic field was like two billion years ago.

When it comes to studying periods much closer to us in time - within the last 10 thousand years - scientists prefer to take materials of artificial origin for analysis, rather than natural lavas or sediments. This is clay baked by humans - dishes, bricks, ritual figurines, etc., which appeared with the first steps of civilization. The advantage of artificial clay crafts is that archaeologists can date them quite accurately.

At the Institute of Earth Physics of the Russian Academy of Sciences, the laboratory of archaeomagnetism was studying changes in the magnetic field. Extensive data obtained in the laboratory and in leading foreign scientific centers was concentrated there. Russian scientists are also doing this.

Indeed, these data confirm that in our time the magnetic field is weakening. But a caveat is necessary here: precise measurements of the field’s behavior over long periods of time indicate that the planet’s magnetic field is subject to numerous oscillations with different periods. If we add them all up, we get the so-called “smoothed curve”, which coincides quite well with a sinusoid having a period of 8 thousand years.

At this time, the total value of the magnetic field is on the descending segment of the sinusoid. This is what caused concern among some authors. Higher values ​​are behind, further weakening of the field is ahead. It will continue for about another two thousand years. But then the field will begin to strengthen. This phase will last 4 thousand years, and then decline again. The previous maximum occurred at the beginning of our era. The multiplicity of magnetic field oscillations is apparently explained by the lack of balance in the moving parts of the hydromagnetic dynamo and their different electrical conductivities.

It is important to note that the amplitude of the sine wave is less than half the average field strength. In other words, these fluctuations cannot in any way reduce the field value to zero. This is the answer to those who believe that the current weakening of the field will eventually open the surface of the globe to particle bombardment from space.

As already mentioned, the curve is the sum of various overlapping oscillations of the Earth’s magnetic field - about a dozen of them have been identified so far. Well-defined periods have a duration of 8000, 2700, 1800, 1200, 600 and 360 years. The periods of 5400, 3600 and 900 years are less clearly visible.

Some of these periods are associated with significant phenomena in the life of the planet.

A period of 8000 years is undoubtedly of a global scale, in contrast to fluctuations of, for example, 600 or 360 years, which have a regional, local character.

Interesting relationships with many natural phenomena of the period of 1800 years. Geographer A.V. Shnitnikov made a comparison of various natural rhythms of the Earth and discovered their connection to the astronomical phenomenon named. Big sares, when the Sun, Earth and Moon are on the same straight line and at the same time the Earth is located at the shortest distance from both the luminary and the satellite. In this case, tidal forces reach their greatest value. The Great Sares repeats itself every 1800 years (with deviations) and is accompanied by the expansion of the globe in the equatorial zone - due to a tidal wave in which the World Ocean and the earth's crust participate. As a consequence of this, the moment of inertia of the planet changes, and it slows down its rotation. The position of the polar ice boundary is also changing, and the ocean level is rising. Great Sares affects the Earth's climate - dry and wet periods begin to alternate differently. Such changes in nature in the past were reflected in the world’s population: for example, the migration of peoples increased...

The Institute of Physics of the Earth set out to find out whether there were connections between the phenomena caused by the Great Sares and the behavior of the magnetic field. It turned out that the 1800-year period of field oscillations is in good agreement with the rhythm of phenomena caused by the relative positions of the Sun, Earth and Moon. The beginnings and ends of the changes and their maxima coincide... This can be explained by the fact that in the liquid mass surrounding the planet’s core, during the Great Sares, the tidal wave also reached its greatest value, therefore, the interaction of matter flows with the internal field also changed.

In the last 10 thousand years, the earth's nature has not suffered any disasters due to a restless magnetic field. But what does the deeper past hide? As is known, the most dramatic events in the Earth's biosphere lie far beyond 10 thousand years. Maybe they were caused by some changes in the magnetic field?

Here we will have to deal with a fact that has alarmed some scientists.

The magnetic fields of the past turned out to be “frozen” into volcanic lavas when they cooled and passed the Curie point. Magnetic fields are also imprinted in bottom sediments: particles sinking to the bottom, if they contain ferromagnets, are oriented along the lines of the magnetic field, like compass needles. It is preserved forever in fossilized sediments, unless the sediments are subjected to strong heating...

Palaeomagnetologists study ancient magnetic fields. They were able to discover truly enormous changes that the magnetic field underwent in the distant past. The phenomenon of inversion - a change of magnetic poles - was discovered. The northern one moved to the place of the southern one, the southern one to the place of the northern one.

By the way, the poles do not change so quickly - according to some estimates, the change lasts 5 or even 10 thousand years.

The last such movement occurred 700 thousand years ago. The previous one is another 96 thousand years earlier. There are hundreds of such shifts in the history of the planet. No regularity was found here - long quiet periods are known, they were replaced by times of frequent inversions.

The so-called “excursions” were also discovered - the departure of the magnetic poles from the geographic ones over long distances, ending, however, with a return to their previous place.

Many have tried to explain the polarity reversals. American scientists R. Muller and D. Morris, for example, believe that the primary cause of this was the impact of giant meteorites. The “shake-up” of the planet forced a change in the nature of the movement of melts in its depths. The authors of this hypothesis were based on the fact that 65 million years ago, the inversion and fall of a large cosmic body to Earth simultaneously occurred, as evidenced by sediments of that time, rich in cosmic iridium. The hypothesis looked impressive, but was unconvincing, if only because the temporal connection between these events was very weakly proven. Another hypothesis is that inversions are triggered by deep melt flows when giant lumps of ferromagnetic material fall into them. These lumps, concentrating the lines of the magnetic field in themselves, seem to “pull” it along with them.

And this hypothesis is controversial.

Obviously, over the billions of years of its existence, the Earth's core must have increased in size. It would seem that this could not but affect the Earth's magnetic field. Meanwhile, scientists who have information about what the planet’s magnetic field was like two billion years ago compare these data with today’s data and do not even find traces of the influence of core growth on the magnetic field. Could a phenomenon of a much more modest scale, such as the hypothetical “clumps” represent, affect the state of the field?

The currently accepted theory of hydromagnetic dynamo is capable of explaining the inversion, but this theory does not mean that a change of poles is obligatory, it just does not contradict this phenomenon.

The reason for the inversions are the same “constructive imperfections” of the natural hydromagnetic dynamo. But these are different defects than those that cause the already familiar spectrum of ten oscillations of the magnetic field, oscillations that monotonously repeat themselves after certain periods of time. Inversions do not have such a regular, systematic character.

One might believe that the phenomenon of inversion, the search for its causes and its consequences will arouse the interest only of researchers of terrestrial magnetism. But no, this phenomenon has attracted the attention of a wide range of scientists, including those who study the development of the earth’s biosphere.

Recently, several scientific articles have suggested that during reversals, the Earth's magnetic field disappears. Thus, we are talking about the planet losing its invisible armor for some time. And this, apparently, can lead to the death of many species of plants and animals. That is why in the changes to which the magnetic field is subject, some see a danger more formidable than that posed by the destructive trio: earthquakes, tsunamis, typhoons.

The authors of this assumption, as proof of their correctness, cite the relationship between the extinction of dinosaurs, which disappeared from the face of the Earth 65 million years ago, and the frequent inversions characteristic of that period.

The hypothesis of such a radical influence of polar reversals on the development of all living nature on Earth was met with particular satisfaction by evolutionists, who in the recent past used a computer to simulate the history of the biosphere of our planet, starting from the primary forms of living matter. The program included all the factors known at that time that influenced mutations and natural selection. The results of the study were unexpected: evolution from the first cell to man in the mathematical interpretation was much slower than in real conditions of earthly nature.

Obviously, the scientists concluded, the program did not take into account some energetic factors that force nature to simultaneously change species. Now, they believe, one of such strong accelerators of evolution has been found - this is the impact on the organic world of cosmic radiation during those periods when the poles exchanged places... Something similar, at least, to the Chernobyl disaster.

Against this background, the assertion of American geophysicists sounds either alarming or reassuring that they discovered layers of lava in Oregon, which show that the field “frozen” in them has rotated 90 degrees in just two weeks. In other words, change does not necessarily require thousands of years, but can be almost instantaneous. That is, the time of the destructive effects of cosmic radiation is short, which reduces their danger. It is not clear why the field rotated not 180 degrees, but only 90.

However, the assumption that during polarity reversals the magnetic field disappears is just an assumption, and not a truth based on reliable facts. On the contrary, some paleomagnetic studies suggest that the field is preserved during reversals. It, however, does not have a dipole structure and is much weaker - 10, and even 20 times. The interpretation of sudden field changes found in lavas from Oregon has raised serious objections. Professor G. Zoffel, whom we mentioned, believes that the discovery of American colleagues can be explained in a completely different way, for example, this way: a magnetic field generated by lightning that struck at that moment was “frozen” into the cooling lava.

But these objections do not exclude the possibility of a direct, perhaps weakened, impact of cosmic particles on the flora and fauna. Many scientists have joined in the search for answers to the questions posed by this hypothesis.

Noteworthy are the considerations expressed at one time by V.P. Shcherbakov, an employee of the Institute of Earth Physics of the USSR Academy of Sciences. He believed that during reversals, the planet’s magnetic field, although weakened, retains its structure, in particular, the magnetic lines of force in the region of the poles still rest against the surface of the planet. Above the moving poles during periods of inversion in the magnetosphere, there are constantly, as in our days, funnels into which cosmic particles seem to be poured.

During periods of inversions, with a weakened field, they can fly up to the surface of the green ball at the closest distances, and perhaps even reach it.

Paleontologists also joined the search. For example, the German professor G. Herm, who, in collaboration with many foreign laboratories, studied bottom sediments dating back to the end of the Cretaceous period. He found evidence that during these times there was a leap in the development of species. However, this scientist considers the inversions of that time to be just one of the factors that pushed evolution. G. Herm does not find any reason to worry about future life on the planet if sudden changes occur in the magnetic field.

Moscow State University Professor B. M. Mednikov, an evolutionary biologist, also does not consider them dangerous and explains why. The main protection from the solar wind, he says, is not the magnetic field, but the atmosphere. Protons and electrons lose their energy in its upper layers above the poles of the planet, causing air molecules to glow, “shine.” If suddenly the magnetic field disappears, then the aurora will probably be not only above the poles, where the magnetosphere now drives particles, but throughout the entire sky - but at the same high altitudes. The solar wind will still remain safe for living things.

B. M. Mednikov also says that evolution does not need to be “spurred on” by cosmic forces. The latest, more advanced computer models of evolution convince: its real speed is fully explained by molecular reasons internal to the body. When, at the birth of a new organism, its apparatus of heredity is created, in one out of a hundred thousand cases the copying of parental characteristics occurs with an error. This is quite enough for animal and plant species to keep up with changes in the environment. We should not forget about the mechanism of mass spread of gene mutations through viruses.

According to magnetologists, B. M. Mednikov’s objections cannot erase the problem. If the direct influence of changes in the magnetic field on the biosphere is unlikely, then there is also an indirect one. There are, for example, undoubted relationships between the planet’s magnetic field and its climate...

As you can see, there are many serious contradictions in the problem of the relationship between the magnetic field and the biosphere. Contradictions, as always, motivate researchers to search.

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