Earth's Magnetic Field and Life

There is another vital benefit of Earth's magnetic field beyond navigating. We are talking about this benefit in our article.
Sailors, who have been on the open seas for centuries, have found their direction using this nature principle. However, the magnetic field of the Earth has a vital benefit beyond navigating. Perhaps this benefit can be seen as a protectionist that owes the existence of not only human beings, but all living things on earth, to the present.

Although we do not want to remember much, we have experienced by experiencing the fatal destruction of radiation on vitality as a result of the Chernobyl, Hiroshima and Nagasaki disasters we encountered when we looked at our recent history. Our Sun, which is one of our renewable energy sources today, radiates dangerous radiation for life every second. Here, the magnetic field of the Earth protects us from this radiation that has thousands of Chernobyl power.

This is an information that relaxes and tells us that we are safe, but studies in recent years have shown that the Earth's magnetic field is weakening with great speed. This attenuation is so fast that in a few tens of millenniums there will be no trace of the Earth's magnetic field! So why is Earth's magnetic field weakening? Can we get information about the changes that occurred in the magnetic field of the Earth in the past? Can this information prepare us for the change regarding the future of the magnetic field? Is there really serious danger?

To answer all these questions, we first need to analyze the Earth's magnetic field well. This analysis is undoubtedly the foundation of a short development process that took place parallel to the invention of magnetism and compass.

The Place of Compass in the Birth and Development of Magnetism

The development of magnetism began at different times in different parts of the world. BC in China It is known that compass was used in the 13th century. B.C. In the 800s the Greeks knew about magnetism. According to legend; a shepherd experienced that magnetite stones (Fe3O4) pulled a different stone in the city of Magnesia (today's Manisa). The origin of the word magnet is also based on ancient Greek and is considered to be derived from the name of the city, Magnesia.
The first written documents we have about magnetism are the sources in which Thales' observations written by Aristotle are explained. According to these writings, Thales discovered that the magnet stone's ability to pull iron was able to attract light objects such as straw and feathers when amber was rubbed with wool. Thales' discovery of the charge of amber is undoubtedly an example of static electricity. These events were thought to be the same since the magnet pulled the iron at that time and the charge of amber with electricity was similar.

The development of magnetism entered a period of stagnation that would last hundreds of years after its discovery. This fundamental force of nature was able to reach a comprehensive analysis only after the 16th century when science was systemized.
In this process, engineering went ahead of science and the magnet was used as a solution to an important problem. Perhaps by chance, perhaps the magnet, which was deliberately stripped, was found to align in the north - south direction when placed on the water. With such a simple reality, the compass was invented. This was an important discovery for that period, but no one knew how this happened. It was Alexander Neckam (1157-1217) who first mentioned the compass in Europe in 1180, but it is known that the compass was found by the Chinese and reached Europe through the Arabs long before that.

Undoubtedly, compass is an important technological invention of the era and human beings have benefited from the magnetic field of the Earth by bringing a practical solution to the problem of finding direction since ancient times. However, since the progress in other fields of science has not reached a sufficient level for a very long period, no serious explanation has been made on how the compass works. Following the meeting of Europe with a compass, this important technological development of the period was removed from the primacy and developed, but it was also the subject of research through which natural event he worked. The first written source on this was created by Peter Peregrinus, a French scholar who studied magnets, in 1269 with the book Epistola de Magnete. Peregrinus described the magnetic pole in his book and mentioned that the same poles repel each other, opposite poles attract each other. Most importantly, he pointed out that by dividing a magnet in two, the poles will not separate from each other, and that both parts will continue to display magnet properties. In the same year, Pierre de Maricourt observed their orientation by placing needles on the surface of a natural magnet. He discovered that these orientations form lines that cross and cross the two points of the magnet, and that every magnetic material, regardless of its shape, has two poles, north and south.
The experiment by Maricourt gave a very similar result to the picture we saw above the magnetic field lines of a magnet. Today we know that a magnet creates lines of invisible magnetic fields. This image can be easily obtained by sprinkling iron powders onto white paper placed on a magnet.

In the 13th century, the works carried out with the enthusiasm to reveal the working principle of the compass then entered a long period of stagnation. We will not consider the development of magnetism in later years, as it has no direct relation with our subject. However, it can be seen that the compass, and therefore the magnetic field of the Earth, has a natural and important effect on the birth and development of magnetism.

In 1600, William Gilbert (1544-1603), the special doctor of Queen Elizabeth I, published his book titled De Magnete. In his book he made a great contribution to the theory of geomagnetism and clarified the working principle of the compass very clearly. Gilbert revealed that the Earth is a global magnet and the compass needle points to the Earth's magnetic pole. He also said that the compass needle, which is aligned in the north-south direction, deviates in the vertical direction.

As a result of the research carried out to reveal the working principles of the compass, it was determined that the magnet had north and south poles, and the pull was carried out by the opposite poles and the push was done by the same poles. In the light of all this information, it was concluded that in order for the compass to work, it must be another magnet that must interact. This magnet had to be in spherical dimensions compared to the fact that the compass works even in open seas. The compass's ability to work clearly required the presence of magnetic field lines that wrap the world from one end to the other. As a result of all these developments, Gilbert was explaining the existence of Earth's magnetic field.

Earth's Magnetic Field

Scientific progress has been behind engineering only a few times. The invention of the compass and the existence of the Earth, whose existence is understood later, is a good example.

The place is like a huge magnet. The magnetic field lines emerging near the south pole point surround the earth along a meridian and end near the north pole point. But the Earth's magnetic pole points and geographic pole points differ slightly.
Earth's magnetic south pole matches the geographic north pole, magnetic north pole matches the geographic south pole. We can understand this as follows. Since the north pole of the compass needle we have will attract the opposite poles, it will be pulled by the Earth's magnetic south pole and thus it will show the geographic north pole. But no magnetic compass can point north with absolute accuracy! This is because the geographic north pole and magnetic south pole do not overlap exactly. There are approximately 11 degrees of angle between the axis connecting the magnetic poles and the axis connecting the geographic poles. For this reason, the north direction indicated by the compass is slightly different from the geographic north. This difference, which may vary depending on the location, is called magnetic deviation, and this results in the conclusion that the direction shown by the compass actually contains a minor error. In addition to this, as seen in the picture above, the compass needle shows direction in the vertical direction as well as in the horizontal direction. This slope formed in the vertical is called magnetic slope and as can be expected, the slope in the equator is measured as zero and increases as the magnetic poles go. At magnetic pole points, since the magnetic field is perpendicular to the earth's surface, the magnetic slope is measured in ninety degrees.

The first question that comes to mind as soon as we face the reality of the Earth's magnetic field is how it came about. Could the existence of a magnetic field that allows sailors to navigate the open seas for centuries and protect all vitality from the lethal radiation of solar winds could be the same magnetic field of any natural magnet?
A computer simulation showing the Earth's magnetic field lines.
Earth's magnetic field lines are quite similar to the magnetic field lines of a magnet. In the first place, the magnetic field may seem to be represented by a giant magnet in the earth, and the large iron reserves in the core of the Earth can strengthen this idea. But it is understood from the existence of high temperatures that such a thing is not possible. The very high temperatures present in the core prevent permanent magnetization.

Although we know that there is no giant magnet in the ground, we do not have a theory today that can consistently explain the existence of the magnetic field. However, the space studies conducted in the last fifty years and the experiments carried out with the creation of the core of the Earth on a laboratory scale revealed some facts. First of all, we know that the Earth's magnetic field cannot be equated with the magnetism of any magnet. The magnetism of a magnet results from an alignment that takes place in atomic dimensions. The infinitely small magnetic effects of the molecules that make up the substance form the general magnetic field of the substance as the molecules line up. This general magnetic field disappears at very high temperatures. Because the temperature is the vibrations of atomic dimensions, and when the temperature rises, the molecules move randomly and the alignment disappears. Therefore, the general magnetic field of matter is also lost.

Based on this information, it is clear that the high rate of iron in the center cannot form a magnetic field due to the high temperatures in the core of the Earth. It is also understood by the observations made by the Mariner 2 spacecraft of Venus planet that the iron in the core is not the source of the magnetic field. Although Venus contains high levels of iron in its nucleus just like Earth, it does not have a magnetic field. So, other reasons must be sought for the source of the magnetic field, and comparisons with other planets may bring us closer to the answer to this question. Considering the rotation time of Venus around its axis, it is seen that it is 243 times slower than Earth. 243 days in the world correspond to 1 day in Venus.

"Could this slow rotation movement be the answer to the observation of the magnetic field on Earth and not to be observed in Venus?" For the answer to the question, scientists who formed a model of Earth's liquid outer core in the laboratory environment saw that the rotational movement is critical for the magnetic field. The rotational motion of the liquid metallic outer core, which contains billions of tons of iron and nickel, and the electric current generated by thermal effects are seen as the source of the magnetic field. In other words, our Earth, which can be seen as a gigantic spherical magnet, owes its magnetic field to its liquid metallic outer core and rotational motion. But we do not yet have any theory apart from this information based on experimental foundations for the causes of the magnetic field.

Attenuation of Magnetic Field

After understanding the magnetism of the world, the curiosity about its changes in the historical process was waiting to be eliminated. This curiosity would combine the branch of geomagnetism and archaeologists who studied Earth's magnetism. Yes, you have not heard wrong! Science can sometimes apply to unexpected areas in order to find answers to the questions it asks, and can put disciplines that cannot be connected with each other in the studies that need to be carried out jointly.

One of the efforts of archaeologists; to learn about the cultural and social structures of civilizations by examining the pots removed from the ground. But these pots tell different things to scientists who study geomagnetism. As it is known, the raw material of the pottery is clay obtained from soil and clay contains a substance called magnetite, which is iron-based. As we briefly mentioned while explaining the causes of magnetization, magnetite material contains magnets with a certain orientation in atomic size. In order for magnetite to be magnetized, its molecules must line up.
Pottery unearthed as a result of archaeological excavations sheds light on the history of the Earth's magnetic field.
In history, when a potter takes clay to process it, magnetite does not have a general magnetic field. Its molecules are ordered irregularly. The potter processes the pile of clay and then puts it in the oven for cooking. The real issue that concerns physicists starts after this point. Magnetite loses its magnetic property above 585 ° C. So, at these temperatures, the molecules in its content completely lose their old irregular orientation. The irregular molecule array of magnetite in the pot placed in the furnace, which does not generate a general magnetic field, disappears when said temperatures are reached. When removed from the oven, the high temperature pot has molecules that vibrate at high energies. This freedom causes the magnetite molecules to get rid of their old irregular arrangement and realign them in the strength and orientation of the earth magnetic field acting on all molecules of the material. When the pottery is left to cool, its historical record begins to be kept. All magnetite molecules become immobile as their energy decreases and they freeze with their new alignment! Nothing wakes up anymore, except to raise them back to 585 ° C. They have become historical witnesses that have kept track of the earth magnetic field at the moment they cooled down.

It can be easily said that; In every pottery removed from archaeological excavations, the magnetic field of the Earth has a historical record. By examining the general magnetic field in a pot known to be dated, information about the severity and orientation of the Earth's magnetic field can be easily obtained at the time the pot was made.

With this method, scientists studying some pots came up with a surprising result; Earth's magnetic field intensity was rapidly decreasing! This was a finding that should be taken seriously, given the benefits of the magnetic field.

The dimensions of the danger waiting for humanity were staggering! It was necessary to go back to older times. To much older dates than man started to make pottery! Is it possible to go back in the history of the magnetic field of the Earth? When the pottery is examined, only short histories can be reached, in which humanity can reach a certain level of civilization. If we can go back much older than human existence, perhaps the dimensions of the danger can be seen more clearly.

Magnetic Tumble - Displacement of Magnetic Poles

For the older one, it is necessary to look at some objects created by the hand of nature, not objects created by man. Scientists have studied volcanic rocks for older. Volcanic rocks, just like pottery, keep track of Earth's magnetic field. The only difference is that this method takes place in the natural process.
Volcanic rocks allow us to study the Earth's magnetic field until much earlier.
Magma has a high temperature when it reaches the earth, so the iron-based materials it contains have an irregular molecular sequence. The cooled lavas are magnetized in a certain amount with their molecules that are directed by the effect of the earth magnetic field. If the Earth's magnetic field is strong during the lava cooling, the magnetic field of the lava will also be severe. If the earth's magnetic field is weak, the lava's magnetic field will be equally weak. Similarly, the same magnetic field in the magnetic lava formed in the cooling lava is the same as the earth's magnetic field has the same orientation. In this direction, scientists who have studied the lava and obtained the magnetic field data of millions of years ago have seen that the field's severity decreased and increased many times. However, lava records revealed a more shocking truth beyond this result. Earth's magnetic poles have been displaced many times! Moreover, when all the findings were combined, it was seen that this event occurred many times in the history of the world. Scientists had an unexpected result.

It is seen that the magnetic tumors that occur in history do not have a regular periodicity when a record is kept. Between about one hundred thousand and one million years, magnetic poles have been constantly displaced and the most recent displacement took place 780 thousand years ago. Based on these data, it seems that a new magnetic displacement is about to happen. Considering the finding that the magnetic field seen from the pottery records is weakened, "can the weakening of the field be a precursor of the magnetic tumble?" comes to mind.

Thanks to the detailed studies conducted and the lava samples examined, it was observed that a similar scenario took place before each magnetic tumble. First, the magnetic field was subjected to continuous weakening, and when its polarity decreased sufficiently, the magnetic tumble was performed. Therefore, the fact that the magnetic field is in constant weakening and that enough time has passed since the last magnetic tumbler as it is understood from the volcanic rocks seems to be the precursors of a new magnetic displacement.

We do not have the slightest answer to why magnetic tumble, one of the important questions, happened. This is due to the fact that the nature of the magnetic field has not yet been fully understood. Although some questions remain unanswered for now, problems always have to be resolved by certain remedies. Otherwise, a dangerous future may be waiting for humanity.

The Vital Benefit of Earth's Magnetic Field

A charged particle moving in the magnetic field is exposed to the force exerted by the magnetic field. No force acts by the magnetic field on the stationary charged particle that does not move. The reason for this is that moving loads can create magnetic fields. The way to interact with a magnetic field is to have a similar magnetic field.
The Earth's magnetic field acts as a shield against the solar winds that are detrimental to our vitality.
The charged particles, such as moving protons and electrons, which undergo magnetic field effect, are forced to move spirally along the field line as a result of the force acting on them if their velocity has components in the direction of the magnetic field. If their velocity does not have a component in the magnetic field direction, they move circularly. The reason for these movements is that the direction of the magnetic force changes momentarily with the direction of the movement.

Space contains some extremely harmful substances for our life. Electrically charged radioactive materials in huge masses are thrown deep into space as a result of explosions in stars. In Supernova explosions, this level reaches an extreme level. The Sun is the primary source of radiation that is harmful to Earth, and it sprays billions of tons of charged particles in a matter of hours. The world is under the invasion of these particles every second. The amount of scattered particles may vary after some large Solar eruptions. These particles drift in space, forming the Sun winds. The magnetic field of the world acts as a shield against the sun winds. The charged particles with radioactive content coming from the sun are trapped by the Earth's magnetic field and flow through the magnetic field and head towards the poles. Magnetic shield protects the level of radiation on earth by preventing solar winds from entering the atmosphere.

Polar lights

These charged particles flowing into the poles cause great visual shows that can be watched from the polar circles. Kriler, who is a Native American people living in Canada, has found it appropriate to call this event "Dance of Spirits". In medieval Europe, polar lights were believed to be signs from God.
Arctic lights seen over Alaska-Bear Lake
Thanks to the advances we have made in science today, we can clearly explain such physical events; The particles trapped by the magnetic field and moving towards the magnetic pole along the field line ionize the oxygen and nitrogen atoms they collide in the atmosphere, in other words they transfer energy to them. When these ionized atoms go down to the basic energy level, they lose their excess energy by releasing photons. Photon propagation creates these colorful images. The colors change depending on the photon emission of oxygen and nitrogen. (You can read a more detailed article about this here)

Polar lights are an important natural phenomenon that occurs as a result of the interaction of charged particles emitted by the Earth's magnetic field and solar winds. It occurs not only on Earth, but also on other planets that have a magnetic field.
Arctic lights observed in Jupiter.
The magnetic field of the world stands before us as an important reality with the compasses we have used for centuries, as a protective shield against the solar winds, and the polar lights that it caused to occur. On the other hand, the fact that the field will weaken during the realization of the magnetic tumble, which we see approaching, and that more charged particles will enter the atmosphere as a result, creates a serious problem for humanity. Cosmic radiation, which will enter the atmosphere in greater amounts with the weakening of the field, will anticipate the radiation level of the earth. It is very difficult to predict the consequences of this on our vitality, but it can be thought that a typical nuclear accident will happen globally this time around.

We know that our magnetic field will not be able to fulfill its protective shield duty for a short time in the future. Magnetic displacement will definitely take place. The only problem is when this will happen. Whenever the civilization of the period will find a solution to this serious problem. Undoubtedly, the fact that the field will weaken during magnetic tumble will not cause a disaster. This event has occurred hundreds of times since the existence of the Earth and our vitality is still standing. In any case, the only field that can ensure that this process can be survived without any damage, will undoubtedly be science!

Beyond all this, there is something we know that one day our children's compass will show the south, not the north. By that day, our scientific level, which was reached with the curiosity of a few scientists, has long been invisible, and science will still be made with the same sense of curiosity specific to questioning minds.

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