Why the core of the earth. The mystery of the earth's core: where does our planet's magnetic field come from

I will try to explain with the example of a basin.

The first mistake - the facts are not collected.

They are very heterogeneous and cluster themselves into systems at different distances from the historical center of knowledge. It's the most important. Science does not collect facts under the basin, it adjusts the basin to the facts. You think differently and do the opposite, this is a delusion, because you throw out those facts that will inevitably contradict your basin, that is, you simply do not see these facts, ignore them.

Further, everything depends on the stage of cognition, many basins are found, those that cover most of the facts are accepted as relatively true and are subsequently used as relative knowledge, which in practice becomes absolute knowledge, and the facts that do not fall, attention on practice are declared as an error, for example, 49%, 30%, etc. to 0% (this is a reflection of the progress of the basins, which is impossible with the thinking that you have). And you see only this, because you are taught this way at school, that this knowledge is a constant, this is just a feature of the teaching method, roughly speaking you are constantly deceived, saying that this knowledge is absolute, and science in general says that this knowledge is relative, this is normal, because this is how our brain is arranged, otherwise it could not learn, not science is imperfect, but our brain is imperfect. And only in a narrow specialization the brain begins to think in abstract scientific concepts, these are specialists, this is what I was talking about above.

But this is practice, and the scientific theory, which we are talking about gradually finding new basins, finds the last one, in which ALL facts from a given group fit at a certain distance, before that basins were called hypotheses, and this mega-basin is called theory (this is an old classification, today everything is hypotheses), and most importantly, it predicts ALL new facts that appear in a certain group, in a certain distance.

Here we are at the stage of a mega-basin today in most areas of knowledge, and what you bring up are old basins that are no longer needed, since they are ineffective, that is, not facts are discarded, but basins.

Now, further, as soon as we comprehended one group of facts, we began to see another group of facts, which are clustered at a farther distance than the center of knowledge and which we simply could not measure and see before and built hypotheses about them based on the facts lying on the borders, that is, there were a lot of basins without practice, which, to a greater or lesser extent, covered the totality of indirect facts that followed from the boundary facts for observation. Until a bowl appeared that would explain them all, all the indirect facts that we cannot see, but we can see their relationship both with the facts known to us before, and with each other. This basin may completely contradict the previous mega basin, because due to the distance, the laws according to which the groups of facts are always different, sometimes opposite.

These are, for example, the theories of Newton (megatazik) and Einstein (new indirect megatazik), they are opposite and at the same time objective. Gradually, due to progress in the often parallel direction of cognition, we are already starting to see direct facts, and not indirect facts, that is, the boundary of the observable is growing and if you are aware, then EVERYTHING in general relativity is experimentally confirmed today, as soon as a tool appears that can do this confirm, that is, an observable, not an indirect fact.

This cycle is endless, this is the guarantee of the effectiveness of the scientific method of cognition, if we do not see the fact and cannot indirectly find it, then we do not even look in its direction and do not worry, because in practice it cannot be used. This is the difference from faith, when such a fact is invented. That is, to the question of whether there is a god, science says I don’t know in theory, but in practice it says no, but this is relative knowledge, as soon as a fact arises in a certain field of knowledge, we will completely reconsider everything.

Another important aspect is predictive, if a new fact appears in a group of facts that were already included in a well-studied group of facts at a certain distance, which has already covered the mega basin, then the theory is declared inoperative and science changes completely, the old mega basin is thrown out, but it does not there is an old thrown out ordinary basin that defeated the mega basin, because it does not correspond to many older facts, but a new basin is being made that can be SIMILAR to the old basins and non-specialists begin to shout that science itself does not know what it wants and all scientific knowledge is bullshit and scientists always lie. This is also a mistake due to the fact that we think in analogies, we think in similarities, this is how neural circuits are arranged.

But we do not know that these new facts within the known group of facts are part of a new group of facts and, so to speak, the tip of the iceberg or part of the old group.

The first case is general relativity, the second case is, for example, the theory of evolution.

That is why we always say in theory that we do not know anything, we do not know whether Newton or Darwin are right, but in practice we say that yes, they are right and objective, and this is what is taught at school, which confuses the student even more. Since they found a bunch of facts that refute both Newton and Darwin, but they turned out to be from a different group of facts, mostly on the border between them. This is called a refinement of the theory, for example, Darwin has a synthetic theory of evolution, a theory of punctuated equilibrium and a modern theory of evolution, in which there is inheritance of acquired traits, etc., what all the previous ones denied and denied rightly, the scale was just different.

Scientists seem to have a new explanation for why the Earth's core remains solid, despite the fact that its temperature is higher than the temperature of the surface of the Sun. It turns out that this may be due to the atomic architecture of the crystallized iron "ball" located in the center of our planet.

The researchers suggest that the earth's core may be characterized by a never-before-seen atomic state that allows it to withstand the incredible temperatures and pressures that are characteristic, according to calculations, for the center of our planet. If scientists are right on this point, then this may help solve another mystery that has been haunting for decades.

A team of researchers at Sweden's Royal Institute of Technology in Stockholm used Triolith, one of the country's most powerful supercomputers, to simulate an atomic process that could take place some 6,400 kilometers below the earth's surface. As with any other metal, the atomic structures of iron can change under the influence of changes in temperature and pressure. At room temperature and at normal pressure, iron is in the so-called body-centered cubic (BCC) phase of the crystal lattice. Under high pressure, however, the lattice transforms into a hexagonal close-packed phase. These terms describe the arrangement of atoms within the crystal lattice of a metal, which, in turn, are responsible for its strength and other properties, such as whether the metal in this case remains in a solid state or not.

It was previously believed that the solid, crystallized state of iron in the Earth's core is due to the fact that it is in the hexagonal close-packed phase of the crystal lattice, since the conditions for bcc are too unstable here. However, a new study may indicate that the environment in the center of our planet actually hardens and condenses the state of the BCC, and does not destroy it.

“Under the conditions of the earth's core, the bcc lattice of iron demonstrates a previously unseen pattern of atomic diffusion. The bcc phase runs under the motto "What doesn't kill me makes me stronger." Instability can interrupt the bcc phase at low temperatures, but high temperatures, on the contrary, increase the stability of this phase,” says lead researcher Anatoly Belonoshko.

As an analogy for the increased activity of atoms in iron in the center of the Earth, Belonoshko cites a deck of shuffling cards, where atoms (represented by cards) can constantly and very quickly mix with each other under the influence of elevated temperature and pressure, but at the same time the deck remains a single whole. And these figures are very impressive: 3.5 million times higher than the pressure that we experience on the surface, and about 6000 degrees Celsius higher temperature.

Data from the Triolith supercomputer also shows that up to 96 percent (higher than previous calculations) of the mass of the Earth's inner core is most likely iron. The remainder is nickel and other light elements.

Another mystery that may be solved thanks to recent research is why seismic waves move faster between the poles and not across the equator. This phenomenon is often referred to as anisotropy. The researchers say that the behavior of the bcc lattice in iron under extreme conditions typical of the center of the Earth may be sufficient for a large-scale anisotropy effect, which, in turn, creates another field for scientists to study in the future.

It is important to note that this assumption was derived on the basis of specific computer simulations of the internal dynamic processes of the Earth, and on the basis of other models, the results of calculations may differ. Until we figure out how to lower the appropriate scientific instruments to such a depth, we will not be able to speak with absolute certainty about the correctness of the calculations. And given the temperature and pressure that can take place there, obtaining direct evidence of the activity of the planet's core may be completely impossible for us.

And yet, despite the difficulties, it is important to continue such research, because as soon as we can learn more about what is really happening inside our planet, we will have a better chance of knowing what will happen next.

MOSCOW, February 12 - RIA Novosti. American geologists say that the inner core of the Earth could not have arisen 4.2 billion years of the Earth in the form in which scientists imagine it today, since this is impossible from the point of view of physics, according to an article published in the journal EPS Letters.

“If the core of the young Earth consisted entirely of a pure, homogeneous liquid, then the inner nucleolus should not exist in principle, since this matter could not cool to those temperatures at which its formation was possible. Accordingly, in this case, the core may be inhomogeneous composition, and the question arises how it became so. This is the paradox we discovered, "says James Van Orman (James Van Orman) from Case Western Reserve University in Cleveland (USA).

In the distant past, the core of the Earth was completely liquid, and did not consist of two or three, as some geologists today suggest, layers - an inner metal core and a melt of iron and lighter elements surrounding it.

In this state, the core quickly cooled and lost energy, which led to the weakening of the magnetic field generated by it. After some time, this process reached a certain critical point, and the central part of the nucleus "froze", turning into a solid metal nucleolus, which was accompanied by a surge and growth in the strength of the magnetic field.

The time of this transition is extremely important for geologists, since it allows us to roughly estimate how fast the Earth's core is cooling today and how long the magnetic "shield" of our planet will last, protecting us from the action of cosmic rays, and the Earth's atmosphere - from the solar wind.

Now, as Van Orman notes, most scientists believe that this happened in the first moments of the Earth's life due to a phenomenon whose analogue can be found in the atmosphere of the planet or in soda machines in fast food restaurants.

Physicists discovered long ago that some liquids, including water, remain liquid at temperatures well below freezing, unless there are impurities, microscopic ice crystals, or powerful vibrations inside. If it is easy to shake it up or drop a speck of dust into it, then such a liquid freezes almost instantly.

Something similar, according to geologists, happened about 4.2 billion years ago inside the Earth's core, when part of it suddenly crystallized. Van Orman and his colleagues tried to reproduce this process using computer models of the planet's interior.

These calculations unexpectedly showed that the inner core of the Earth should not exist. It turned out that the process of crystallization of its rocks is very different from how water and other supercooled liquids behave - this requires a huge temperature difference, more than a thousand kelvins, and an impressive size of "dust grain", whose diameter should be about 20-45 kilometers.

As a result, two scenarios are most likely - either the core of the planet should have frozen completely, or it still should have remained completely liquid. Both are not true, since the Earth does have an inner solid and an outer liquid core.

In other words, scientists do not yet have an answer to this question. Van Orman and his colleagues invite all geologists of the Earth to think about how a sufficiently large "piece" of iron could form in the planet's mantle and "drown" in its core, or find some other mechanism that would explain how it was divided into two parts.

With a thickness of about 2200 km, between which a transition zone is sometimes distinguished. The mass of the core is 1.932 10 24 kg.

Very little is known about the core - all information is obtained by indirect geophysical or geochemical methods, and images of the core matter are not available, and are unlikely to be obtained in the foreseeable future. However, science fiction writers have already described in detail several times the journey to the core of the Earth and the untold riches hidden there. The hope for the treasures of the core has some grounds, since according to modern geochemical models, the content of noble metals and other valuable elements is relatively high in the core.

History of study

Probably one of the first assumptions about the existence of an area of ​​increased density inside the Earth was made by Henry Cavendish, who calculated the mass and average density of the Earth and found that it is much higher than the density characteristic of rocks emerging on the earth's surface.

The existence was proved in 1897 by the German seismologist E. Wiechert, and the depth (2900 km) was determined in 1910 by the American geophysicist B. Gutenberg.

Similar calculations can be made for metallic meteorites, which are fragments of the nuclei of small planetary bodies. It turned out that the formation of the core in them occurred much faster, over a time of the order of several million years.

Theory of Sorokhtin and Ushakov

The described model is not the only one. So, according to the model of Sorokhtin and Ushakov, presented in the book "Earth Development", the process of formation of the earth's core stretched for approximately 1.6 billion years (from 4 to 2.6 billion years ago). According to the authors, the formation of the core occurred in two stages. At first, the planet was cold, and there was no movement in its depths. Then it was warmed up by radioactive decay enough to begin to melt metallic iron. It began to flow to the center of the earth, while due to gravitational differentiation, a large amount of heat was released, and the process of separation of the core only accelerated. This process went only to a certain depth, below which the substance was so viscous that the iron could no longer sink. As a result, a dense (heavy) annular layer of molten iron and its oxide was formed. It was located above the lighter substance of the primeval "core" of the Earth.

Why does the Earth's core not cool down and remains heated to a temperature of approximately 6000°C for 4.5 billion years? The question is extremely complex, to which, moreover, science cannot give a 100% accurate intelligible answer. However, there are objective reasons for this.

Too much mystery

Excessive, so to speak, the mystery of the earth's core is associated with two factors. Firstly, no one knows for sure how, when and under what circumstances it was formed - it happened during the formation of the proto-Earth or already in the early stages of the existence of the formed planet - all this is a big mystery. Secondly, it is absolutely impossible to get samples from the earth's core - for sure no one knows what it consists of. Moreover, all the data that we know about the nucleus is collected by indirect methods and models.

Why does the Earth's core stay hot?

To try to understand why the earth's core does not cool down for such a long time, you first need to figure out what caused it to warm up in the first place. The bowels of ours, like any other planet, are heterogeneous, they are relatively clearly demarcated layers of different densities. But this was not always the case: the heavy elements slowly descended, forming the inner and outer core, the light ones were forced out to the top, forming the mantle and the earth's crust. This process proceeds extremely slowly and is accompanied by the release of heat. However, this was not the main reason for the heating. The entire mass of the Earth with great force presses on its center, producing a phenomenal pressure of approximately 360 GPa (3.7 million atmospheres), as a result of which the decay of radioactive long-lived elements contained in the iron-silicon-nickel core began to occur, which was accompanied by colossal heat emissions .

An additional source of heating is the kinetic energy generated as a result of friction between different layers (each layer rotates independently of the other): the inner core with the outer and the outer with the mantle.

The bowels of the planet (the proportions are not met). Friction between the three inner layers serves as an additional source of heating.

Based on the above, we can conclude that the Earth and, in particular, its bowels are a self-sufficient machine that heats itself. But it cannot continue so naturally forever: the stocks of radioactive elements inside the core are slowly disappearing and there will be nothing left to maintain the temperature.

It's getting cold!

In fact, the cooling process has already begun a very long time ago, but it proceeds extremely slowly - by a fraction of a degree per century. According to rough estimates, it will take at least 1 billion years for the core to cool completely and stop chemical and other reactions in it.

Short answer: The earth, and in particular the earth's core, is a self-sufficient machine that heats itself. The entire mass of the planet presses on its center, producing phenomenal pressure and thereby starting the process of decay of radioactive elements, as a result of which heat is released.

Our planet Earth has a layered structure and consists of three main parts: the earth's crust, mantle and core. What is the center of the earth? Core. The depth of the core is 2900 km, and the diameter is approximately 3.5 thousand km. Inside - a monstrous pressure of 3 million atmospheres and an incredibly high temperature - 5000 ° C. In order to find out what is in the center of the Earth, it took scientists several centuries. Even modern technology could not penetrate deeper than twelve thousand kilometers. The deepest borehole, located on the Kola Peninsula, has a depth of 12,262 meters. Far from the center of the earth.

The history of the discovery of the earth's core

One of the first to guess about the presence of a nucleus in the center of the planet was the English physicist and chemist Henry Cavendish at the end of the 18th century. With the help of physical experiments, he calculated the mass of the Earth and, based on its size, determined the average density of the substance of our planet - 5.5 g / cm3. The density of known rocks and minerals in the earth's crust turned out to be approximately two times less. From this followed a logical assumption that in the center of the Earth there is an area of ​​denser matter - the core.

In 1897, the German seismologist E. Wiechert, studying the passage of seismological waves through the inner parts of the Earth, was able to confirm the assumption of the presence of a core. And in 1910, the American geophysicist B. Gutenberg determined the depth of its location. Subsequently, hypotheses about the process of formation of the nucleus were also born. It is assumed that it was formed as a result of the settling of heavier elements to the center, and initially the substance of the planet was homogeneous (gaseous).

What is the core made of?

It is quite difficult to study a substance whose sample cannot be obtained in order to study its physical and chemical parameters. Scientists have only to assume the presence of certain properties, as well as the structure and composition of the nucleus by indirect signs. Especially helpful in the study of the internal structure of the Earth was the study of the propagation of seismic waves. Seismographs, located at many points on the surface of the planet, record the speed and types of passing seismic waves arising from tremors of the earth's crust. All these data make it possible to judge the internal structure of the Earth, including the core.

To date, scientists suggest that the central part of the planet is heterogeneous. What is at the center of the earth? The part adjacent to the mantle is a liquid core, consisting of molten matter. Apparently, it contains a mixture of iron and nickel. This idea led scientists to the study of iron meteorites, which are pieces of asteroid nuclei. On the other hand, the obtained iron-nickel alloys have a higher density than the expected density of the core. Therefore, many scientists tend to assume that in the center of the Earth, the core, there are also lighter chemical elements.

Geophysicists also explain the existence of a magnetic field by the presence of a liquid core and the rotation of the planet around its own axis. It is known that an electromagnetic field around a conductor arises when current flows. The molten layer adjacent to the mantle serves as such a giant current-carrying conductor.

The inner part of the nucleus, despite the temperature of several thousand degrees, is a solid. This is due to the fact that the pressure in the center of the planet is so high that hot metals become solid. Some scientists suggest that the solid core consists of hydrogen, which, under the influence of incredible pressure and enormous temperature, becomes like a metal. Thus, what is the center of the Earth, even geophysicists are still not known for certain. But if we consider the issue from a mathematical point of view, we can say that the center of the Earth is located approximately 6378 km. from the surface of the planet.

The Earth's core includes two layers with a boundary zone between them: the outer liquid shell of the core reaches a thickness of 2266 kilometers, under it there is a massive dense core, the diameter of which, according to estimates, reaches 1300 km. The transition zone has a non-uniform thickness and gradually hardens, passing into the inner core. On the surface of the upper layer, the temperature is in the region of 5960 degrees Celsius, although these data are considered approximate.

Approximate composition of the outer core and methods for its determination

Very little is known about the composition of even the outer layer of the earth's core, since it is not possible to obtain samples for study. The main elements of which the outer core of our planet can consist are iron and nickel. Scientists came to this hypothesis as a result of analyzing the composition of meteorites, since wanderers from outer space are fragments of the nuclei of asteroids and other planets.

Nevertheless, meteorites cannot be considered absolutely identical in chemical composition, since the original cosmic bodies were much smaller than the Earth in size. After much research, scientists came to the conclusion that the liquid part of the nuclear substance is highly diluted with other elements, including sulfur. This explains its lower density than iron-nickel alloys.

What happens in the outer part of the planet's core?

The outer surface of the core at the boundary with the mantle is inhomogeneous. Scientists suggest that it has a different thickness, forming a kind of internal relief. This is due to the constant mixing of heterogeneous deep substances. They are different in chemical composition and also have different densities, so the thickness of the boundary between the core and the mantle can vary from 150 to 350 km.

Fantasists of the past years in their works described a journey to the center of the Earth through deep caves and underground passages. Is it really possible? Alas, the pressure on the surface of the core exceeds 113 million atmospheres. This means that any cave would tightly “slam” even at the stage of approaching the mantle. This explains why there are no caves deeper than even 1 km on our planet.

How is the outer layer of the nucleus studied?

Scientists can judge what the core looks like and what it consists of by monitoring seismic activity. So, for example, it was found that the outer and inner layers rotate in different directions under the influence of a magnetic field. The core of the Earth still holds dozens of unsolved mysteries and is waiting for new fundamental discoveries.

The Earth, along with other bodies of the solar system, was formed from a cold gas and dust cloud by accretion of the particles that made it up. After the appearance of the planet, a completely new stage of its development began, which in science is usually called pregeological.
The name of the period is due to the fact that the earliest evidence of past processes - igneous or volcanic rocks - is not older than 4 billion years. Only scientists today can study them.
The pre-geological stage of the development of the Earth is still fraught with many mysteries. It covers a period of 0.9 billion years and is characterized by a wide manifestation of volcanism on the planet with the release of gases and water vapor. It was at this time that the process of stratification of the Earth into the main shells began - the core, mantle, crust and atmosphere. It is assumed that this process was provoked by an intense meteorite bombardment of our planet and the melting of its individual parts.
One of the key events in the history of the Earth was the formation of its inner core. This probably happened at the pregeological stage of the planet's development, when all matter was divided into two main geospheres - the core and the mantle.
Unfortunately, a reliable theory about the formation of the earth's core, which would be confirmed by serious scientific information and evidence, does not yet exist. How did the core of the Earth form? To this question, scientists offer two main hypotheses.
According to the first version, the substance immediately after the formation of the Earth was homogeneous.
It consisted entirely of microparticles, which can be observed today in meteorites. But after a certain period of time, this initially homogeneous mass was divided into a heavy core, where all the iron glassed, and a lighter silicate mantle. In other words, drops of molten iron and the heavy chemical compounds that accompanied it settled to the center of our planet and formed a core there, which remains largely molten to this day. As heavy elements aspired to the center of the Earth, light slags, on the contrary, floated up - to the outer layers of the planet. Today, these light elements make up the upper mantle and the earth's crust.
Why did such a differentiation of matter occur? It is believed that immediately after the completion of the process of its formation, the Earth began to heat up intensively, primarily due to the energy released in the process of gravitational accumulation of particles, as well as due to the energy of the radioactive decay of individual chemical elements.
An additional heating of the planet and the formation of an iron-nickel alloy, which, due to its significant specific gravity, gradually descended to the center of the Earth, was facilitated by the alleged meteorite bombardment.
However, this hypothesis faces some difficulties. For example, it is not entirely clear how an iron-nickel alloy, even in a liquid state, could sink more than a thousand kilometers and reach the region of the planet's core.
According to the second hypothesis, the core of the Earth was formed from iron meteorites that collided with the surface of the planet, and later it was overgrown with a silicate shell of stone meteorites and formed the mantle.

There is a serious flaw in this hypothesis. In this situation, in outer space, iron and stone meteorites should exist separately. Modern studies show that iron meteorites could only have arisen in the bowels of a planet that broke up under significant pressure, that is, after the formation of our solar system and all planets.
The first version looks more logical, since it provides for a dynamic boundary between the Earth's core and the mantle. This means that the process of separation of matter between them could continue on the planet for a very long time, thereby exerting a great influence on the further evolution of the Earth.
Thus, if we take the first hypothesis of the formation of the planet's core as a basis, then the process of differentiation of matter stretched for about 1.6 billion years. Due to gravitational differentiation and radioactive decay, the separation of matter was ensured.
Heavy elements sank only to a depth below which the substance was so viscous that iron could no longer sink. As a result of this process, a very dense and heavy annular layer of molten iron and its oxide was formed. It was located above the lighter substance of the primordial core of our planet. Further, a light silicate substance was squeezed out from the center of the Earth. Moreover, it was forced out at the equator, which, perhaps, marked the beginning of the asymmetry of the planet.
It is assumed that during the formation of the iron core of the Earth, a significant decrease in the volume of the planet occurred, as a result of which its surface has decreased by now. The light elements and their compounds that “surfaced” to the surface formed a thin primary crust, which, like all planets of the terrestrial group, consisted of volcanic basalts overlain from above by a layer of sediments.
However, it is not possible to find living geological evidence of past processes associated with the formation of the earth's core and mantle. As already noted, the oldest rocks on planet Earth are about 4 billion years old. Most likely, at the beginning of the evolution of the planet, under the influence of high temperatures and pressures, primary basalts metamorphosed, melted down and transformed into granite-gneiss rocks known to us.
What is the core of our planet, which was formed, probably, at the earliest stages of the Earth's development? It consists of outer and inner shells. According to scientific assumptions, at a depth of 2900-5100 km there is an outer core, which in its physical properties approaches liquid.
The outer core is a stream of molten iron and nickel, a good conductor of electricity. It is with this core that scientists associate the origin of the earth's magnetic field. The 1270 km gap remaining to the center of the Earth is occupied by the inner core, which is 80% iron and 20% silicon dioxide.
The inner core is hard and high temperature. If the outer is directly connected with the mantle, then the inner core of the Earth exists by itself. Its hardness, despite the high temperatures, is ensured by the gigantic pressure in the center of the planet, which can reach 3 million atmospheres.
Many chemical elements as a result pass into a metallic state. Therefore, it has even been suggested that the inner core of the Earth consists of metallic hydrogen.
The dense inner core has a serious impact on the life of our planet. The planetary gravitational field is concentrated in it, which keeps light gas shells, the hydrosphere and geospheric layers of the Earth from scattering.
Probably, such a field has been characteristic of the core since the formation of the planet, whatever it was then in terms of its chemical composition and structure. It contributed to the contraction of the formed particles to the center.
Nevertheless, the origin of the core and the study of the internal structure of the Earth is the most urgent problem for scientists who are closely involved in the study of the geological history of our planet. The final solution of this issue is still very far away. To avoid various contradictions, modern science has adopted the hypothesis that the process of core formation began to occur simultaneously with the formation of the Earth.