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Where did the earth's magnetic field come from? Earth as a magnet: Geomagnetic field

The Earth's magnetic field is a formation generated by sources within the planet. It is the object of study of the corresponding section of geophysics. Next, let's take a closer look at what the Earth's magnetic field is, how it is formed.

general information

Not far from the surface of the Earth, approximately at a distance of three of its radii, the lines of force from the magnetic field are arranged in a system of "two polar charges". Here is an area called the "plasma sphere". With distance from the surface of the planet, the influence of the flow of ionized particles from the solar corona increases. This leads to compression of the magnetosphere from the side of the Sun, and vice versa, the Earth's magnetic field is pulled out from the opposite, shadow side.

plasma sphere

A tangible effect on the surface magnetic field of the Earth is exerted by the directed movement of charged particles in the upper layers of the atmosphere (ionosphere). The location of the latter is from a hundred kilometers and above from the surface of the planet. The Earth's magnetic field holds the plasmasphere. However, its structure strongly depends on the activity of the solar wind and its interaction with the retaining layer. And the frequency of magnetic storms on our planet is due to solar flares.

Terminology

There is a concept of "magnetic axis of the Earth". This is a straight line that passes through the corresponding poles of the planet. The "magnetic equator" is the great circle of the plane perpendicular to this axis. The vector on it has a direction close to the horizontal. The average strength of the Earth's magnetic field is significantly dependent on geographical location. It is approximately equal to 0.5 Oe, that is, 40 A / m. At the magnetic equator, the same indicator is approximately 0.34 Oe, and near the poles it is close to 0.66 Oe. In some anomalies of the planet, for example, within the Kursk anomaly, the indicator is increased and amounts to 2 Oe. Field lines of the Earth's magnetosphere with a complex structure , projected onto its surface and converging at its own poles, are called "magnetic meridians".

The nature of occurrence. Assumptions and conjectures

Not so long ago, the assumption about the connection between the emergence of the Earth's magnetosphere and the current flow in a liquid metal core, located at a distance of a quarter or a third of the radius of our planet, gained the right to exist. Scientists have an assumption about the so-called "telluric currents" flowing near the earth's crust. It should be said that over time there is a transformation of the formation. The Earth's magnetic field has changed many times over the past one hundred and eighty years. This is fixed in the oceanic crust, and this is evidenced by studies of remanent magnetization. By comparing the sections on both sides of the ocean ridges, the time of divergence of these sections is determined.

Earth's magnetic pole shift

The location of these parts of the planet is not constant. The fact of their displacements has been recorded since the end of the nineteenth century. In the Southern Hemisphere, the magnetic pole has shifted by 900 km during this time and ended up in the Indian Ocean. Similar processes are taking place in the northern part. Here the pole is shifting towards the magnetic anomaly in Eastern Siberia. From 1973 to 1994, the distance that the section moved here was 270 km. These pre-calculated data were later confirmed by measurements. According to the latest data, the speed of the magnetic pole of the Northern Hemisphere has increased significantly. It has grown from 10 km/year in the seventies of the last century to 60 km/year at the beginning of this century. At the same time, the strength of the earth's magnetic field decreases unevenly. So, over the past 22 years, it has decreased by 1.7% in some places, and somewhere by 10%, although there are also areas where, on the contrary, it has increased. The acceleration in the displacement of the magnetic poles (by approximately 3 km per year) gives reason to assume that their movement observed today is not an excursion, this is another inversion.

This is indirectly confirmed by the increase in the so-called "polar gaps" in the south and north of the magnetosphere. The ionized material of the solar corona and space rapidly penetrates into the resulting extensions. From this, an increasing amount of energy is collected in the subpolar regions of the Earth, which in itself is fraught with additional heating of the polar ice caps.

Coordinates

The science that studies cosmic rays uses the coordinates of the geomagnetic field, named after the scientist McIlwain. He was the first to suggest using them, since they are based on modified variants of the activity of charged elements in a magnetic field. Two coordinates (L, B) are used for a point. They characterize the magnetic shell (the McIlwain parameter) and the field induction L. The latter is a parameter equal to the ratio of the average distance of the sphere from the center of the planet to its radius.

"Magnetic inclination"

Several thousand years ago, the Chinese made an amazing discovery. They found that magnetized objects can be placed in a certain direction. And in the middle of the sixteenth century, Georg Cartmann, a German scientist, made another discovery in this area. This is how the concept of "magnetic inclination" appeared. This name means the angle of deviation of the arrow up or down from the horizontal plane under the influence of the planet's magnetosphere.

From the history of research

In the region of the northern magnetic equator, which is different from the geographic one, the northern end goes down, and in the south, on the contrary, it goes up. In 1600, the English physician William Gilbert first made assumptions about the presence of the Earth's magnetic field, causing a certain behavior of pre-magnetized objects. In his book, he described an experiment with a ball equipped with an iron arrow. As a result of research, he came to the conclusion that the Earth is a large magnet. The experiments were also carried out by the English astronomer Henry Gellibrant. As a result of his observations, he came to the conclusion that the Earth's magnetic field is subject to slow changes.

José de Acosta described the possibility of using a compass. He also established the difference between the Magnetic and North Poles, and in his famous History (1590) the theory of lines without magnetic deviation was substantiated. Christopher Columbus also made a significant contribution to the study of the issue under consideration. He owns the discovery of the inconsistency of the magnetic declination. Transformations are made dependent on changes in geographic coordinates. Magnetic declination is the angle of deviation of the arrow from the North-South direction. In connection with the discovery of Columbus, research intensified. Information about what the Earth's magnetic field is was extremely necessary for navigators. M. V. Lomonosov also worked on this problem. For the study of terrestrial magnetism, he recommended conducting systematic observations using permanent points (like observatories) for this. It was also very important, according to Lomonosov, to carry out this at sea. This idea of the great scientist was realized in Russia sixty years later. The discovery of the Magnetic Pole in the Canadian archipelago belongs to the English polar explorer John Ross (1831). And in 1841, he also discovered the other pole of the planet, but already in Antarctica. The hypothesis about the origin of the Earth's magnetic field was put forward by Carl Gauss. Soon he also proved that most of it is fed from a source inside the planet, but the reason for its slight deviations is in the external environment.

First, consider what the Earth's magnetic field is. After all, first of all, the degree of influence of cosmic factors on the earth's atmosphere, as well as on human life and health, depends on it.

The Earth's magnetosphere is surrounded by intense radiation, which in a short time can decompose all the air in the Earth's atmosphere into ions and electrons and lead to other irreversible consequences in the Earth's biosphere and lithosphere, after which life on Earth would be impossible. The Earth's magnetic field protects us from this radiation. Actually, there is no other protection against high-energy corpuscular radiation in nature. If this protection were impeccable, then here we could not describe in more detail how the protective shell of the Earth is arranged. But it turns out that there are weaknesses or defects in the Earth's magnetic field, through which part of the solar radiation still enters its atmosphere. These defects in the Earth's magnetic shell are characteristic of certain zones, the location of which depends on the nature and configuration of the Earth's magnetic field. The zones are characterized by a special space climate, and the space weather in these zones differs significantly from that in other parts of the globe.

What is the earth's magnetic field? We know that a magnetized bar always has two poles - north and south, or, in other words, is a dipole. The configuration of the magnetic field is usually characterized by magnetic lines of force that have a certain direction (indicated by an arrow), and the density of these lines is determined by the magnitude of the magnetic field. To determine the direction of the magnetic field line, it is necessary to place the compass at different points in space around the magnet. The direction of the arrow each time and will show the direction of the magnetic field line. Who among us does not remember school experiments with magnets and metal filings? Here, each sawdust is a magnetic needle. In these experiments, the magnetic field of the dipole looks like this: the magnetic field lines come out of one pole of the magnet and enter the other pole. As you move away from the bar, the magnetic field strength decreases very quickly.

Now imagine that we placed such a bar inside the school globe with the south magnetic pole up (ie, to the north geographic pole), and the north down. Next, we will tilt this magnetic bar relative to the geographic axis so that an angle of 11 ° is formed between them, in other words, we will separate the geographic and geomagnetic poles by approximately 1100 km on the globe. After such a manipulation, a magnetic dipole will be obtained, similar to the earth's. True, a real terrestrial magnetic dipole has shifted not only the poles. The center of the dipole slightly coincides with the center of the globe, but this is not essential for the problem considered here. The Earth's dipole field is shown in Figure 1. The magnetic field of such a dipole is fairly easy to calculate.

Fig 1. Diagram of the dipole magnetic field of the Earth. The axis of the Earth (SYO) and the axis of the magnetic dipole (P With P YU) do not match. Magnetic meridians come from one magnetic poles to another.

(Attention!!! There is an error in this picture. See comments below. The correct picture is at the very end of the page.- Approx. admin.)

But the real magnetic field of the Earth is different from the dipole field. This is caused by the action of solar corpuscular radiation on it.

In the equatorial plane (middle of the dipole), magnetic field lines run parallel to the Earth's surface, while closer to the poles they exit the Earth in the south and enter the Earth in the north. This difference in the direction of the magnetic field lines is fundamental. How they are directed depends on how they are able to withstand solar corpuscular radiation.

In order for the magnetic field to serve as protection against solar corpuscular radiation and, in general, from any particles that have a negative or positive electric charge, it must be directed across the direction of radiation. At low latitudes, the Earth's magnetic field is directed across the radiation flux, and it serves as a good protection against it. Unfortunately, the closer to the poles, the less reliable this protection is. Where the lines of force of the magnetic field are vertical (at the poles), they are not able to counteract the radiation, and it can "roll" along the lines of force into the Earth's atmosphere without interference.

Everything would be exactly as described here if the Earth's magnetic field were exactly the field of a dipole. In fact, the earth's magnetic dipole is not located in a vacuum, and electric currents flow around it, which change its magnetic field. From the outside, the pressure force of the solar wind, i.e., solar plasma, acts on the Earth's magnetic field.

What is solar corpuscular radiation, we will consider a little further. Here we will only say that from the surface of the Sun, a plasma, consisting of the nuclei of light chemical elements, continuously propagates radially in all directions, the flows of which are called the solar wind. This solar wind, approaching the Earth's magnetic field, deforms it, as an ordinary wind could deform an air-filled balloon. As a result, the Earth's magnetic field from the side of the Sun does not extend to infinity, as it would in the case of an ideal dipole, but is compressed by the solar wind to a distance of 10 Earth radii (the Earth's radius is 6.370 km).

Thus, from the day side, our earthly home extends into space for approximately 63,700 km. Further, the Earth's magnetic field ends and the real space begins, the properties of which are completely different than those within the Earth's magnetic shell - the magnetosphere. This space inside the magnetosphere is commonly called near space or near-Earth space. This division is by no means arbitrary, since deep space has completely different magnetic fields, other characteristics of charged particles, etc.

The solar wind, which pressed the Earth's magnetosphere from the day side, changes the magnetic field lines on the night side and stretches them in the direction of its movement away from the Sun, like a rubber band of a slingshot. This is how a trail, or tail, of the magnetosphere is formed, extending on the night side of the Earth for hundreds of Earth radii. Thus, if an ideal magnetic dipole is symmetrical about the magnetic axis connecting the poles, then the Earth's magnetic field is very strongly deformed - closer to the Earth (at a distance of 3 - 4 Earth radii), the dipole remained almost untouched and the magnetic field lines rotate with the Earth, just as like the Earth's atmosphere, while the outer lines of force, extended into the tail of the magnetosphere, cannot rotate with the Earth, they are always extended in the night direction. At the same time, the near-pole field lines on the day side are twisted by the solar wind so that they go to the night side through the pole into the magnetotail.

If there were no solar wind, then the most vulnerable places on Earth would be the regions near the poles, where the magnetic field lines are vertical. But the solar wind, as it were, covers these areas with daytime field lines, which it directs through the poles into the magnetotail. At the same time, the most vulnerable band remains on the day side between the lines of force, closing through the day and night sides of the Earth. From which it is clear that on the day side there are two areas where the solar corpuscular radiation can break through into the upper atmosphere, despite the magnetic protection of the Earth. It can also be seen that the polar caps (the areas around the poles) are protected by daytime magnetic field lines. How much the solar wind distorts the Earth's magnetic field can be seen from a comparison of Fig. 1 and 2.

On the night side of the Earth, the outermost lines of force, to which the solar wind directly “clings” and which are extended into the tail of the magnetosphere for hundreds of Earth radii, are torn. After the break, the halves of the field line (southern and northern) grow together (or collapse) again and quickly rush back towards the Earth, taking charged particles with them. In place of these field lines, new ones, which have just been broken, enter the magnetotail. This process continues continuously.

It can be seen in Fig. 2 that on the night side at latitudes of 70° north and south there are also field lines that rest almost vertically on the Earth's surface and, therefore, do not prevent radiation from penetrating into the upper atmosphere. Thus, we can conclude that in certain areas the magnetic field does not protect the Earth and its atmosphere well enough from solar corpuscular radiation. These vulnerable areas are two ovals located around the north and south geomagnetic poles, the day parts of which are 10° away from the magnetic pole, and the night parts are 20° away. The width of this oval is only a few degrees, that is, several hundred kilometers. These two ovals are the places where the kitchen of space weather is located, where the northern and southern lights are most often seen, where electric currents of hundreds of thousands of amperes flow at an altitude of 100 km, where conditions for human health in terms of the influence of space weather on him are unfavorable.

We have established where bad space weather zones are located on Earth and what is the reason for their location. Next, it is necessary to analyze what constitutes solar corpuscular radiation. Therefore, we turn to the consideration of solar plasma ejection during solar storms.

Always wondered how the compass works? And today we will talk about such a thing as the MAGNETIC FIELD of the EARTH. And since, unfortunately, the editor is limited in time, and I want to give something interesting, we will tell you about “terrestrial magnetism” using several different sources.

So:

Earth's magnetic field long time remained a mystery, because there are no stone magnets, right? But as soon as you discover that there is a colossal amount of iron inside the Earth, everything seems to fall into place. Iron does not form a "permanent" magnet, like those attached to plastic piglets and bear cubs, which we ourselves, without knowing why, buy to attach to the refrigerator. The bowels of the earth are more like a dynamo. By the way, this is what is called - geomagnetic dynamo. As we have already mentioned, the iron in the core of the Earth is mostly in a molten state, with the exception of a solid, dense "ball" in the very center. The liquid part still continues to heat up. Previously, this phenomenon was explained by the fact that radioactive elements, being denser than anything else in the chemical composition of the planet, sank into the very center, being locked there, and heat was generated by the radioactive energy emitted by them. The modern theory offers a completely different explanation: the liquid part of the nucleus heats up, since the solid part cools down. Molten iron on contact with a solid core solidifies itself little by little, while heat is released. That heat has to go somewhere, it can't just disappear like a puff of warm air around a thousand miles of solid rock. Heat is transferred to the molten layer of the core, heating it.

It may surprise you that the part that comes into contact with the solid core can cool and solidify and, at the same time, heat up during this solidification. The explanation is simple: hot molten iron rises as it heats up. Remember the balloon. When you heat air, it rises. This is because when heated, the air expands, becomes less dense, and less dense substances float above denser ones. The balloon holds the air in a huge silk bag, often brightly colored and emblazoned with bank or real estate emblems, and rises with the air. Hot iron is unpainted, but rises in the same way as hot air, moving away from a solid core. It floats slowly, cooling down, and then, when it gets too cold, more precisely relatively cold, begins to sink into the depths again. As a result, the earth's core is in constant motion, heating up inside and cooling down outside. It cannot rise all at once, that is, some areas of the core rise, while others sink again. This kind of circulating heat transfer is called convection.

According to physicists, under certain three conditions, moving liquids can create a magnetic field. First, the liquid must conduct electricity, and iron does an excellent job of this. Secondly, at least a small magnetic field must initially be present, and there are good reasons to believe that our Earth, then very young, had a certain amount of personal magnetism. Thirdly, something must rotate this liquid, distorting the initial magnetic field, and for the Earth such rotation occurs due to the Coriolis force, similar to centrifugal force, but acting more weakly and resulting from the rotation of the Earth around its axis. Roughly speaking, the rotation distorts the initially weak magnetic field, twisting it like spaghetti on a fork. Then the magnetism rises up, caught by the floating masses of the iron core. As a result of all this rotation, the magnetic field becomes much stronger.

Yes, in a sense, you can say that the Earth behaves as if it has a huge magnet inside it, but in fact, everything is much more complicated. To flesh out the picture a little, let's recall that there are at least seven other factors that determine the presence of a magnetic field in the Earth. So, some components of the earth's crust can be permanent magnets. Like a compass needle pointing north, they gradually lined up along the stronger geomagnetic dynamo, further strengthening it. In the upper layers of the atmosphere there is a layer of charged ionized gas. Before satellites were invented, the ionosphere played a critical role in radio communications: radio waves bounced off charged gas instead of escaping into space. The ionosphere is in motion, and moving electricity creates a magnetic field. At an altitude of about 15,000 miles (24,000 km), a ring current flows, a layer of low-density ionized particles that forms a huge torus. This slightly weakens the strength of the Earth's magnetic field.

The next two factors are the so-called magnetopause and the magnetic tail, which have arisen under the influence of the solar wind on the Earth's magnetosphere. The solar wind is a constant stream of particles emitted by a hyperactive Sun. The magnetopause is the head wave of the earth's magnetic field, going against the solar wind, and the magnetic tail is the trace of this wave from the opposite side of the planet, where the Earth's own magnetic field "leaks" outward, besides being destroyed under the influence of the solar wind. In addition, the solar wind causes a kind of thrust along the Earth's orbit, creating an additional distortion of the magnetic field lines, known as field-aligned current in the magnetosphere. And finally, there are auroral flows. The Northern Lights, or aurora borealis, are delightful, mysterious sheets of pale light shimmering in the northern polar sky. A similar spectacle, aurora australis, can be seen near South Pole. Auroras are created by two bands of electric current flowing from the magnetopause into the magnetic tail. This, in turn, creates new magnetic fields and two electrical currents - western and eastern.

So you're saying the Earth is just a big magnet? Well, yes, and the ocean is a bowl of water.

Magnetic materials found in ancient rocks testify that from time to time the Earth's magnetic field changes its polarity, the north magnetic pole becomes south and vice versa. This happens about once every half a million years, although a strict pattern could not be traced. No one knows exactly why this happens, but mathematical models show that the Earth's magnetic field can be oriented equally in both directions, and neither direction is stable. Any position sooner or later loses stability and passes the baton to the opposite one. The transitions occur quickly, over about 5 thousand years, while the periods between them are a hundred times longer.

Most planets have magnetic fields, and this fact is even more difficult to explain than the earth's field. We still have a lot to learn about planetary magnetism.

Alfred Wegener

One of the most impressive properties of our planet was discovered in 1912, but was not taken into account until the 60s. The most convincing evidence in its favor was precisely the change of magnetic poles. We are talking about the fact that the earth's continents do not stand still, but slowly drift on the surface of the planet. According to the German scientist Alfred Wegener, who first published his theory, the current separate continents used to be one supercontinent, which he called Pangea(i.e. "All the earth"). It existed about 300 million years ago.

Surely Wegener was not the first to think of this. His idea, at least in part, arose under the influence of the amazing similarity of the outlines of the coasts of Africa and South America. On the map, this is especially evident. Naturally, Wegener relied on other data as well. He was not a geologist, but a meteorologist, a specialist in ancient climate, and he was surprised that in regions with a cold climate, rocks are found that clearly arose in regions with a warm one, and vice versa. For example, in the Sahara you can still find the remains of ancient glaciers, which are 420 million years old, and in Antarctica - petrified ferns. In those days, anyone would have told him that the climate had simply changed. However, Wegener was convinced that the climate remained practically the same, with the exception of the ice age, but that the continents themselves had changed, that is, moved. He assumed that they separated as a result of convection in the earth's mantle, but he was not sure.

This idea was considered insane, especially since it was not proposed by a geologist, and besides, Wegener ignored all the facts that did not fit into his theory. And that the similarities between Africa and South America not so perfect, and that the drift of the continents could not be explained. Convection obviously has nothing to do with it, since it is too weak. Great A'Tuin(suspects that A'Tuin is a girl), he may carry the whole world on his back, but he is just a fiction, and in the real world, it seems that such forces are simply unthinkable.

The word "unthinkable" we used not by chance. Many brilliant and respected scientists often repeat the same mistake. They confuse the expression "I don't understand how this can be" with "It's completely impossible." One of those, ashamed to admit one of us two, was a mathematician, and an excellent one, but when his calculations showed that the earth's mantle could not move the continents, it did not even occur to him that the theories on which the calculations were based were erroneous. His name was Sir Harold Jeffreys, and his problem was that he obviously lacked a flight of fancy, because not only did the outlines of the continents on both sides of the Atlantic coincide. From the point of view of geology and paleontology, too, everything converged. Take, for example, the petrified remains of a beast named mesosaurus, who lived 270 million years ago simultaneously in South America and Africa. It is unlikely that the mesosaurus swam across the Atlantic Ocean; rather, he simply lived on Pangea, having managed to settle on both continents when they were not yet separated.

However, in the 60s of the twentieth century, Wegener's idea was recognized, and his theory of "continental drift" was established in science. At a meeting of leading geologists, a young man named Edward Ballard, very reminiscent of Pondering Toops, and two of his colleagues demonstrated the capabilities of the then new device called a computer. They instructed the machine to find the best match not only between Africa and South America, but also North America and Europe, given possible, but small changes. Instead of taking the current coastline, which was not a very bright idea from the beginning, allowing drift opponents to argue that the continents did not coincide, the young scientists used a contour corresponding to a depth of 3200 feet (1000 m) below sea level, since, according to in their opinion, it was less eroded. The contours fit well and the geology is just so great. And although the people at the conference still did not come to consensus, the theory of continental drift finally received some recognition.

Today we have much more evidence and a clear understanding of the drift mechanism. In the central part of the Atlantic Ocean, halfway between South America and Africa, one of the mid-ocean ridges stretches from south to north (there are such, by the way, in all other oceans). Volcanic materials rise from the bowels along the entire ridge, and then spread along its slopes. And this has been happening for 200 million years. You can even send a submarine and just watch the process. Of course, the whole human life is not long enough to notice this, but America is moving away from Africa at a rate of 3/4 inch (2 cm) per year. Our nails grow at about the same rate, however, modern equipment is able to register these changes.

The most striking evidence of continental drift comes from the Earth's magnetic field: the rocks on both sides of the ranges have a curious pattern of magnetic stripes that reverse polarity from north to south and back, with the pattern on both slopes symmetrical. This means that the strips were frozen in the magnetic field as they cooled. When from time to time the earth's dynamo changed its polarity, the rocks of the ridge became magnetized in its field. Then, after the separation of the magnetized rocks, the same patterns appeared on opposite sides of the ridge.

The surface of the Earth is not a solid sphere. Both the continents and the ocean floor float on huge, especially hard plates that can move apart when magma seeps between them. (More often than not, this is due to mantle convection. It's just that Jeffreys didn't know everything we know about mantle movement.) There are about a dozen plates, ranging in width from six hundred (1,000 km) to six thousand (10,000 km) miles, and they keep turning. Where their boundaries touch, rub and slide, earthquakes and volcanic eruptions are constantly occurring. Especially in the Pacific Fire Belt, which stretches along the entire perimeter of the Pacific Ocean and includes the western coast of Chile, Central America, the USA and beyond the Japanese Islands and New Zealand. All of them are on the edge of one giant plate. Where plates collide, mountains arise: one plate is under another and lifts it, crushing and crushing its edge. India is not part of the Asian continent at all, it just crashed into it, creating the highest mountains in the world - the Himalayas. She accelerated so much that she still continues her movement, and the Himalayas are growing.

(c) Discworld Science, Terry Pratchett, Jack Cohen, Ian Stewart(Actually, read this book, you won’t find a better entertaining aid (but before that, in principle, familiarize yourself with Pratchett’s “Flat World” series in bibliographic NOT AS POPULAR order)).

Video of the Magnetic field from Roskosmos:

How the compass works

Who hasn't seen a compass? A small thing that looks like a clock with one hand. You twist it, turn it, and the arrow stubbornly turns in one direction. The compass needle is a magnet that rotates freely on the needle. The principle of operation of a magnetic compass is based on the attraction-repulsion of two magnets. Opposite poles of magnets attract, like poles repel. Our planet is also such a magnet. Its strength is not great, it is not enough to manifest itself on a heavy magnet. However, a light compass needle, balanced on a needle, also turns under the influence of a small magnetic field.

sports compass

So that the compass needle does not hang out, but clearly shows the direction, regardless of the shaking, it must be sufficiently strongly magnetized. In sports compasses, a flask with an arrow is filled with liquid. Non-aggressive for plastic and metal parts, does not freeze in winter temperatures. The air bubble left in the flask carries the functions of a level indicator to orient the compass in a horizontal plane.

The primacy in the study of the Earth's magnetic field belongs to the English scientist William Gilbert. In his book "On the Magnet, Magnetic Bodies, and the Great Magnet - the Earth", published in 1600, he presented the Earth as a giant permanent magnet, the axis of which does not coincide with the axis of rotation of the Earth. The angle between the rotation axis and the magnetic axis is called the magnetic declination.

As a result of this discrepancy, it is not entirely correct to say that the compass needle always points to the north. It points to a point located at a distance of 2100 km from the North Pole, on Somerset Island (its coordinates are 75 °.6 N, 101 ° W - data for 1965). The Earth's magnetic poles drift slowly. In addition to such an error in the direction of the arrow (we will call it systematic), one should also not forget about other reasons for the compass to work incorrectly:

Metal objects or magnets near the compass will deflect the needle.
Electronic devices that are sources of electromagnetic fields
Deposits of minerals - metal ores
Magnetic storms that occur during years of strong solar activity distort the Earth's magnetic field.

And now, try to answer the questions for the savvy:

In the meantime, I'll give you a few interesting facts about the earth's magnetic field.

It turns out that it weakens by about 0.5% every 10 years. According to various estimates, it will disappear in 1-2 thousand years. It is assumed that at this moment there will be a polarity reversal of the magnet - the Earth. After that, the field will begin to grow again, but the north and south magnetic poles will change places. It is believed that this has happened to our planet a huge number of times.

It turns out that migratory birds also navigate “by compass”, more precisely, the Earth’s magnetic field serves as a guide for them. Recently, scientists have learned that birds have a small magnetic “compass” in the eye area - a tiny tissue field in which magnetite crystals are located, which have the ability to be magnetized in a magnetic field.

The simplest compass can be made independently. To do this, leave a sewing needle next to the magnet for several days. After that, the needle will be magnetized. After moistening it with fat or oil, gently lower the needle onto the surface of the water poured into the cup. Fat will not let her drown, and the needle will turn from north to south (well, or vice versa :).

Impressed? Now, you can check your answers to the questions:

Where do you think the compass needle would point if you were between the geographic north pole and the magnetic north pole?
- The northern end of the arrow will point .. to the south, and the southern end - to the north!
Where does the arrow point when the compass is in the region of the magnetic pole?
- it turns out that an arrow suspended on a thread in the region of the magnetic pole tends to turn around ... down, along the magnetic lines of the Earth!
If, guided by a compass, for a very long time to go all the time strictly to the northeast, then where will you come?
- you will come to the north magnetic pole! Try to trace your path on the globe, it turns out a very interesting route.

and this could look like a marine compass on the ship Columbus

We hope you enjoyed this article. If yes, then we will make more of these different ones!

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To understand the concept of a magnetic field, you need to connect the imagination. The earth is a magnet with two poles. Of course, the size of this magnet is very different from the red-blue magnets familiar to people, but the essence remains the same. Magnetic field lines come out of the south and go into the ground at the north magnetic pole. These invisible lines, as if enveloping the planet with a shell, form the Earth's magnetosphere.

The magnetic poles are located relatively close to the geographic poles. Periodically, the magnetic poles change location - every year they move 15 kilometers.

This "shield" of the Earth is created inside the planet. The outer metallic liquid core generates electric currents due to the movement of the metal. These currents generate magnetic field lines.

Why do you need a magnetic shell? It holds the particles of the ionosphere, which in turn support the atmosphere. As you know, the layers of the atmosphere protect the planet from deadly cosmic ultraviolet radiation. The magnetosphere itself also protects the Earth from radiation by repelling the solar wind that carries it. If the Earth had not had a "magnetic shield", there would be no atmosphere, and life on the planet would not have arisen.

The meaning of the magnetic field in magic

Esotericists have long been interested in the earth's magnetosphere, believing that it can be used in magic. It has long been known that the magnetic field affects the magical abilities of a person: the stronger the influence of the field, the weaker the ability. Some practitioners use this information by influencing their enemies with magnets, which also reduce witchcraft power.

A person is able to sense a magnetic field. How and by what organs this happens is still unclear. However, some magicians who study human capabilities believe that this can be used. For example, many believe that it is possible to transfer thoughts and energy to each other by connecting to streams.

Also, practitioners believe that the magnetic field of the earth affects the human aura, making it more or less visible to clairvoyants. If you study this feature in more detail, you can learn to hide your aura from prying eyes, thereby strengthening your own protection.

Magic healers often use regular magnets in healing. This is called magnetotherapy. However, if it is possible to treat people with ordinary magnets, then the giant magnetosphere of the Earth can give even greater results in treatment. Perhaps there are already practitioners who have learned to use the general magnetic field for such purposes.

Another direction in which magnetic force is used is the search for people. By adjusting magnetic devices, the practitioner can use them to find the place where this or that person is located, without resorting to other measurements.

Bioenergetics also actively use magnetic waves for their own purposes. With its help, they can cleanse a person from damage and settlers, as well as cleanse his aura and karma. By strengthening or weakening the magnetic waves that bind all people on the planet, you can make love spells and lapels.

By influencing magnetic fluxes, it is possible to control the energy flows in human body. So some practices can affect the psyche and brain activity of a person, inspire thoughts and become energy vampires.

However, the most important area of magic, in the development of which an understanding of the power inherent in the magnetic field will help, is levitation. The ability to fly and move objects through the air has long excited the minds of dreamers, but practitioners consider such skills to be quite probable. Proper appeal to natural forces, knowledge of the esoteric side of geomagnetic fields and a sufficient amount of forces can help magicians fully move in the air.

The electromagnetic field of the Earth also has one curious property. Many magicians assume that this is also the information field of the Earth, from which you can draw all the information you need to practice.

Magnetotherapy

A particularly interesting method of using the strength of magnetic fields in esotericism is magnetotherapy. Most often, such treatment occurs due to conventional magnets or magnetic devices. With their help, magicians treat people both from diseases of the physical body, and from a variety of magical negativity. Such treatment is considered extremely effective, as it shows a positive result even in advanced cases of the destructive effects of black magic.

The most common method of treatment with a magnet is associated with the perturbation of energy fields at the time of the collision of the magnet poles of the same name. Such a simple impact of magnetic waves of the biofield makes a person’s energy shake up sharply and begin to actively develop “immunity”: literally tear and push out of himself magical negative. The same applies to diseases of the body and psyche, as well as karmic negativity: the power of the magnet can help cleanse the soul and body of any pollution. A magnet in its action is similar to an energetic for internal forces.

Only a few practitioners are able to use the forces of the vast earthly information field. If you learn how to work correctly with the energy-information field, you can achieve amazing results. Small magnets are extremely effective in esoteric practices, and the strength of the entire earthly magnet will give much greater opportunities for controlling forces.

Current state of the magnetic field

Realizing the significance of the geomagnetic field, one cannot but be horrified to learn that it is gradually disappearing. For the past 160 years, its power has been dwindling, and at a terrifyingly fast pace. So far, a person practically does not feel the influence of this process, but the moment when problems begin is getting closer every year.

The South Atlantic anomaly is the name given to a huge area of the Earth's surface in the southern hemisphere, where the geomagnetic field is weakening most noticeably today. Nobody knows what caused this change. It is assumed that already in the 22nd century there will be another global change of magnetic poles. What this will lead to can be understood by studying the information about the value of the field.

The geomagnetic background is weakening unevenly today. If in general on the surface of the Earth it fell by 1-2%, then in the place of the anomaly - by 10%. Simultaneously with the decrease in the field strength, the ozone layer also disappears, due to which ozone holes appear.

Scientists do not yet know how to stop this process, and believe that with a decrease in the field, the Earth will gradually die. However, some magicians believe that during the period of the decline of the magnetic field, the magical abilities of people are steadily growing. Thanks to this, by the time the field is almost completely gone, people will be able to control all the forces of nature, thereby saving life on the planet.

Many more magicians are sure that natural disasters and strong changes in people's lives occur due to the weakening geomagnetic background. The tense political environment, changes in the general mood of mankind and the growing number of cases of the disease they associate with this process.

The magnetic poles change places about once every 2.5 centuries. North goes to the place of the south, and vice versa. No one knows the reasons for the origin of this phenomenon, and how such movements affect the planet is also unknown.
Due to the formation of magnetic currents inside the globe, there are earthquakes. Currents cause the movement of tectonic plates, which cause earthquakes with high scores.
The magnetic field is what causes the northern lights.
People and animals live under the constant influence of the magnetosphere. In humans, this is usually expressed by the body's reactions to magnetic storms. Animals, on the other hand, under the influence of the electromagnetic flow, find the right path - for example, birds during migration are guided precisely along them. Also, turtles and other animals feel where they are, thanks to this phenomenon.
Some scientists believe that life on Mars is impossible precisely because of its lack of a magnetic field. This planet is quite suitable for life, but is unable to repel radiation, which destroys in the bud all life that could exist on it.
Magnetic storms caused by solar flares affect people and electronics. The strength of the Earth's magnetosphere is not strong enough to completely withstand flares, so 10-20% of the flare energy is felt on our planet.
Despite the fact that the phenomenon of reversal of magnetic poles has been little studied, it is known that during the period of change in the configuration of the poles, the Earth is more susceptible to radiation exposure. Some scientists believe that it was during one of these periods that the dinosaurs became extinct.
The history of the development of the biosphere coincides with the development of the Earth's electromagnetism.

It is important for every person to have at least basic information about the geomagnetic field of the Earth. And for those who practice magic, it is all the more worth paying attention to these data. Perhaps soon practitioners will be able to learn new methods of using these forces in esotericism, thereby increasing their strength and giving the world new important information.

Such a phenomenon as magnetism has been known to mankind for a very long time. It got its name thanks to the city of Magnetia, which is located in Asia Minor. It was there that a huge amount of iron ore was discovered. We can find the very first mention of the unique in the works of Titus Lucretius Cara, who wrote about it in the poem “On the Nature of a Thing”, around the 1st century BC.

Since ancient times, people have found use for the unique properties of iron ore. One of the most common devices, the action of which was based on the attraction of metals, was the compass. Now it is very difficult to imagine various industries in which simple magnets and electromagnets would not be used.

The Earth's magnetic field is an area around the planet that protects it from the harmful effects of radioactive materials. Scientists still argue about the origin of this field. But most of them believe that it arose thanks to the center of our planet has a liquid external and solid internal component. During rotation, the liquid part of the nucleus moves, dressed up electrical particles move and a so-called magnetic field is formed.

The Earth's magnetic field is also called the magnetosphere. The concept of "magnetism" is a comprehensive and global property of nature. On the this moment it is impossible to create a completely complete theory of solar and terrestrial attraction, but even now science is trying to understand a lot and it manages to give a fairly convincing explanation of various aspects of this complex phenomenon.

Recently, scientists and ordinary citizens have been largely concerned about the fact that the Earth's magnetic field is gradually weakening its influence. It has been scientifically proven that over the past 170 years, the magnetic field has been steadily weakening. This makes you wonder, since it is a kind of shield that protects the Earth and wildlife from the terrible radiation effects of the sun's rays. resists the flow of all such particles that fly towards the poles. All these streams linger in the upper atmosphere at the poles, forming a beautiful phenomenon - the northern lights.

If suddenly the Earth's magnetic field disappears or weakens to a large extent, then everything on the planet will be under the direct influence of cosmic and solar radiation. In turn, this will lead to radiation diseases and damage to all living organisms. The consequence of such a disaster will be terrible mutations or complete death. To my great relief, such a development of events is unlikely.

Paleomagnetologists were able to provide fairly reliable data that the magnetic field is constantly fluctuating, and the period of such fluctuations is different. They also made an approximate curve of the field fluctuations and found out that at the moment the field is in a downward position and will decrease for another couple of thousand years. Then it will increase again for 4 thousand years. The last maximum value of the attraction of the magnetic field occurred at the beginning of the current era. The reasons for such instability are put forward in a variety of ways, but there is no specific theory about this.

It has long been known that many magnetic fields have a negative effect on living organisms. For example, animal experiments have shown that an external magnetic field can delay development, slow down cell growth, and even change the composition of the blood. That is why they lead to a deterioration in the health of weather-dependent people.

For a person, the safe magnetic field of the Earth is a field with a strength value of no more than 700 oersteds. It is worth noting that we are not talking about the actual magnetic field of the Earth, but about the electromagnetic fields that are formed during the operation of any radio and electrical device.

The physical side of the process of the influence of the Earth's magnetic field on a person is still not entirely clear. But we managed to find out that it affects plants: the germination and further growth of seeds directly depend on their initial orientation with respect to the magnetic field. Moreover, its change can either accelerate or slow down the development of the plant. It is possible that someday this property will be used in agriculture.

Earth is the force of its attraction. In some places it fluctuates, but the average is 0.5 oersted. In some places (in the so-called tension increases to 2 Oe.