The length of the earth's equator line. What is the equator? The earth stands on three pillars...

The equator is an imaginary line that divides the Earth into the Northern and Southern Hemispheres and acts as the starting point for geographic latitude. Countries located closest to the equator are distinguished by a hot, equatorial climate, the peculiarity of which is the absence of pronounced seasonal temperature changes; in such countries, the temperature is approximately the same all year round, +25 - +30 degrees.

Are there many countries through which the equator line passes? Let's count together.

In our understanding, the equator must pass through the land territory of the country; territorial waters do not apply to this. That is, we need countries where we can stand with one foot in the northern hemisphere and the other in the southern.

1. Sao Tome and Principe.

A small island state off the coast of Africa in the Gulf of Guinea. One of the tiny islands of this country - Rolas (port. Ilhéu das Rolas) is crossed by the equator. At the intersection there is a stele indicating the unusual position of the island, and there is also a bar and hotel.

2. Gabon.

Despite the fact that the equator divides the country almost in half, Gabon makes little use of this feature to attract tourists. There is not a single populated area on the equator. On the numerous roads crossing the equator, you won’t even see any post or sign notifying you that you are already in the other hemisphere.

3. Republic of the Congo.

The equator crosses the country into a sparsely populated area amidst dense jungle. As in Gabon, you will not find any information on the roads that cross the equator. Only in the small town of Makua, located precisely on the equator, there is a small frame of a globe on a dilapidated pedestal, from which one can guess that the equator passes here.

4. Democratic Republic Congo.

Not far from the border with the Republic of Congo, on the outskirts of the city of Mbandaka, there is a commemorative plaque, as well as in a couple of other places where major transport arteries (rivers or roads) cross the equator.

5. Uganda.

In the town of Cayabu, near Lake Victoria, there is a popular tourist complex in the form of two rings, where the equator line is indicated.

6. Kenya.

Tourism in this country is relatively well developed. That is why in Kenya, unlike other African countries, the fact of crossing the equator is very actively publicized. For example, in the city of Maseno, in the west of the country, there is a stele on the side of the road notifying that you have crossed the equator, and 200 meters to the east, right on the equator, there is a tourist complex with hotels and hostels. There is also a sign on the Nakuru - Eldoret highway and other busy roads.

Interesting fact, in the village of Nyang’oma-Kogelo, 100 m from the equator, there is a school named after the senator and former president USA - Barack Obama. In addition, the house of Obama's father's second wife is located in the same village.

7. Somalia.

The equator line runs through southern Somalia. But the country is immersed in its own problems: hunger, poverty, Civil War and an unstable political situation. Therefore, there is no time for tourism in Somalia. There is not a single stele or even sign in the country that you are crossing the equator.

Indonesia is a country in southeast Asia, located on several hundred islands. The equator crosses the three largest islands: Sumatra, Kalimantan, Sulawesi, as well as about ten smaller ones.

Along the entire line of the equator there are sculptures in the form of a globe indicating the direction of the equator.

9. Ecuador.

The name of the country itself comes from the word equator. 20 km north of the country's capital Quito, in San Antonio there is one of the most famous monuments along the entire equator line - “The Middle of the World”.

In addition, Ecuador has the highest point of the equator (4690 m), which is located on the southern slope of the Cayambe volcano, and only in this place on the equator can snow cover be observed. Another interesting fact is that in the Galapagos Islands (belonging to Ecuador), the equator passes directly through the active Wolf Volcano, which erupted on May 25, 2015.

10. Colombia.

The equator passes through the south of the country, where the impenetrable Amazon jungle is located. Tourists rarely set foot in these places. There is no infrastructure.

11. Brazil.

In Brazil, the equator line runs through the north of the country, in the west it goes through impassable jungle. In the municipality of Rorainópolis, the equator crosses the highway; a memorial with an indicator of the direction of the equator in the form of a hockey stick has been erected at this place. In addition, the city of Macapa in the Amazon Delta is located simultaneously in the Northern and Southern Hemispheres. In this city there is the Zeran stadium, crossed by the equator line almost along midline fields. Nearby is Marco Zero - a “monument” to the equator. From Marco Zero east almost to the Amazon coast, “Equatorial Street” (port. Avenida Equatorial) runs along the equator. Also interesting is the fact that the delta of the world's deepest river, the Amazon, is located precisely on the equator.

In total, we counted 11 countries through which the equator line passes. In some countries they are very proud of this fact and elevate it to the status of a national treasure, while others do not even react to it. In any case, crossing the equator line is a big event for a tourist, and this fact remains in the memory for a long time.

Equator in Latin means "call". It is generally accepted that the equator is a conventional circle dividing the globe into the northern and southern hemispheres, and the longest circle (or parallel) of the Earth, perpendicular to its axis of rotation.

The equator is the starting point for determining the coordinates of any place on the planet. Without it, it would be impossible to determine the exact position in space of any geographical objects, or it would be extremely difficult.

Everyone has long known that, to be academically accurate, the Earth is actually not a sphere, but a geoid. Geoid- a body whose proportions resemble a sphere, but is not one. Indeed, at the highest point of the planet the height is 8,848 m (Mount Everest) and at the lowest - 10,994 m (Mariana Trench) relative to sea level.

That is, if we take into account all the elevation differences, then any calculation will cause a lot of problems. Therefore, in the international community, for simplicity of calculations, our planet is usually considered a sphere. Including the equator is considered a circle, although in reality it is not one.

According to the international standard WGS-84 The radius of the Earth is 6,378,137 m. According to another standard, IAU-1976 and IAU-2000, the radius of the Earth is 6,378,140 m. The difference of three meters is due to the difference in approaches and calculation methods. However, the length of the equator is 40,075 km, whichever standard we take, since after calculating the circumference using the formula l=2πR the difference will only be in the second decimal place.

Calculation history

The first attempts to calculate the length of the equator were made V Ancient Greece Eratosthenes. Although, in fact, if we take the world known at that time, he did not calculate the equator, but the radius of the Earth in the region of Europe, which is tied to the circumference through 2πR. At that time, there was no scientific concept of the Earth as a planet.

Without going into details of the experiment, let us explain its essence. Eratosthenes determined that at the moment when in the city of Siena (now Aswan) the Sun is at its zenith and illuminates the bottom of the well, at the same moment in time in Alexandria it “lags” by about 7 degrees and does not illuminate the bottom of the well. Which, in turn, is approximately 1/50 of the circle. Now, knowing the distance from Siena to Alexandria (it was about 5000 stadia), it was possible to determine the circumference.

All the more unexpected are the results of the calculations. Eratosthenes considered the length of the equator to be 252,000 stadia. But since during his life he lived in both Alexandria (Egypt) and Athens (Greece), historians and geographers still cannot say with certainty which stages Eratosthenes used in his calculations. If Greek, then according to Eratosthenes the radius was 7,082 km, if Egyptian - 6,287 km. Whichever result you take for your time, it was an incredibly accurate calculation of the radius.

Later, attempts to calculate the length of the equator were adopted by many European scientists. For the first time, he spoke about the possible averaging of the radius for the convenience of calculations in calculations Dutchman Snellius. In the 17th century, he proposed calculating the radius without taking into account natural obstacles. In the 18th century, France (the first country) switched to the metric measurement system. Moreover, when calculating the standard of length, French scientists were tied precisely to the radius of the Earth.

The calculation was tied to the length of a mathematical pendulum, the half-cycle of which is one second. For its time, the idea was breakthrough. However, when traveling to southern latitudes, the French cartographer Jean Richet noticed that the period of oscillation had increased. The reason was that the Earth is a geoid and gravity decreases closer to the equator.

Research in Russia

IN Russian Empire Research was also carried out to determine the shape, length and other parameters of the Earth. Perhaps the largest and most important of them was project "Russian Arc" or "Struve Arc" under the leadership of Friedrich Georg Wilhelm Struve (Vasily Yakovlevich Struve). To carry out measurements, 265 triangulation points were constructed, which were 258 triangles with a common side. The length of the arc was 2820 km, which is 1/14 of the circumference of the Earth. The arc at that time passed through the territory of Norway, Sweden and the Russian Empire. The research was personally financed by Emperor Alexander I, and later by Nicholas I.

This project was the first of the measurements of the Earth, which accurately determined its shape and parameters. When measuring Earth parameters using satellite methods in the 20th century, Struve’s measurement error was 2 cm.

In the Soviet Union, the geodetic school also made attempts to calculate the parameters of the Earth's ellipsoid. In 1940, thanks to the work of A.N. Izotov and F.N. Krasovsky's ellipsoid was calculated and adopted as a standard for geodetic work in the USSR, which determines all the main parameters of the Earth's ellipsoid. According to Krasovsky, the following parameters are accepted:

1. The Earth's minor radius (polar radius) is 6,356.863 km.
2. Large radius (equatorial) 6,378.245 km.
3. The length of the equator is 40,075.696 km.
4. The surface area of ​​the Earth is 510,083,058 km2.

These facts will be interesting to know:

1. A car in Russia travels 40,075 km on average in two years.
2. The Earth's rotation speed at the equator is 465 meters per second, which is faster than the speed of sound. This is related to the preference for launching spacecraft closer to the equator. At launch, the rocket is already moving at supersonic speed relative to the Earth. This saves fuel significantly.
3. The only glacier on the equator is the cap of the Cayamba volcano in Ecuador.
4. When moving from the pole to the equator, objects and bodies lose 0.53% of their mass. This is due to the distance from the Earth's center of mass.
5. Not a single traveler has yet managed to walk along the earth's part of the equator.
6. In Brazil, in the city of Macapa there is a football stadium, in the middle of which the equator line runs.

Video

You will learn a lot of useful information about the Earth from this video.

Where does the equator lie and what is it, what is its duration, and why did scientists even need to come up with this imaginary line? Let's talk about all this in more detail.

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Definition of the concept

The equator is a conventional line that runs exactly through the center of our planet. Geographical latitude of the equator- 0 degrees. It serves as a reference point and allows scientists to carry out various calculations, which will be discussed below. The equator divides the globe into two absolutely equal parts.

Important! In the territories along which the equator passes, night is always equal to day, without deviation even for a split second.

The equatorial zone receives the greatest amount of ultraviolet rays. Consequently, the further a point is from the conditional line, the less heat and light it receives. That is why the highest temperatures were recorded in the area of ​​the conventional line.

Purpose

To carry out various calculations, scientists need to identify special dividers of the planet, which are the equator, parallels and meridians.

These conditional lines make it possible to determine the position of various objects, enable planes to navigate in, and ships - to.

In addition, it is this strip that allows scientists to divide the entire territory of the planet into climatic zones or belts.

In fact, the circumference of the equator is a key metric characteristic that is taken into account. It helps not only in sciences such as geodesy or elementary geography, but also in astrology and astronomy.

The territories of fourteen states are currently located on the equator. The political map of the world is constantly changing: countries appear and disappear, their borders can expand or contract. Which states are we talking about:

• Brazil,
• Ecuador,
• Indonesia,
• Maldives and other countries.

What is the circumference of the Earth at the equator

According to the most accurate calculations, the length of the equator in kilometers is 40075 km. But the length of the Earth's equator in miles reaches 24901 miles.

As for such a concept as radius, it can be polar and equatorial. The dimensions of the first in kilometers reach 6356, and the second – 6378 km

All areas located in close proximity to this imaginary line have a warm and humid climate.

It is no coincidence that life is simply bustling in these areas. This is where the greatest concentration is concentrated variety of plant and animal species.

Equatorial forests are considered the densest in the world, and some of them are even impenetrable wilds, even taking into account all modern scientific achievements.

Precipitation in the equatorial zone is almost daily and very heavy. It is precisely because everything that is located and grows here shines with a wide variety of colors.

On the planet there is a volcano called Wolf. So, the fact is that it is currently active and, interestingly, is on both sides of the conventional line.

Attention! The average annual temperature in this zone reaches 25-30 degrees Celsius.

High temperatures all year round make the countries that are in this region an ideal holiday destination for tourists. This is especially true for popular resorts located in the Maldives, where millions of vacationers from all over the world come every year.

Important! There is a glacier at the equator. It is located at an altitude of 4690 meters on the slope of a volcano called Cayambe.

This is an amazing place, especially for... The fact is that the speed of rotation of the Earth on this conventional line reaches more than 460 meters per second.

The speed of sound reaches only 330 meters per second. Therefore, any spacecraft, which are launched from here, already seem to start at supersonic speed.

We talked about the extent of the equator, what role it plays in modern life person. As many as three countries are named as part of it.

Without this conditional line, people would not be able to accurately determine the location of the island or even famous city. All planes and ships are guided by a conventional map of latitudes and parallels, where the key place is played by a line that crosses the Earth in exactly two halves.

The Congo River crosses the Earth's midline twice.

What is the equator, its characteristics

Calculate the length of the Earth's equator

Conclusion

The length of the equator is 40,075 kilometers. So that you can appreciate how huge this is, let’s compare it with the mileage of a regular passenger car. On average, a regular Nissan Juke needs three years to cover a similar distance. This line divides the planet into the Northern and Southern Hemispheres. It is here that the wettest regions of the planet are located, where the largest number of species of animals and plants, which we are accustomed to call exotic, are concentrated. It is here, in countries with a very warm climate, that he comes greatest number tourists.

Hi all! Last Sunday we marked another important point of our journey - at the equator. The equator is the zero parallel of the Earth, which divides the planet into the Northern and Southern Hemispheres. The equator passes through 14 countries in South America, Africa and Southeast Asia. But it is the equator in Ecuador that is considered the official middle of the Earth. Why? Because it was here that the equator was actually discovered! Ecuador has a very favorable area for studying the equator, because... in other regions, the imaginary line runs through impenetrable jungle, swamps or deserts.

Amazing story

The equator was discovered by a French geodetic expedition in the 18th century. Team leader La Condamine spent 10 years in Ecuador conducting research. He proved that the planet is not round - it is flattened at the poles. Accordingly, the widest part of the Earth is the equator.

Today, the official center of the world is located in the Ecuadorian city of Mitad del Mundo (“Mitad del mundo” - translated from Spanish literally “middle of the world”), 20 km from the capital of Ecuador, Quito. There is a huge entertainment complex here, the main attraction of which is the yellow line of the zero parallel.

Also in the park there is a famous 30-meter tower topped with a globe. On the days of the spring and autumn solstice, the monument does not cast a shadow. Inside the tower there are several floors of museums where you can perform a variety of physical experiments that are only possible at the equator.

In addition to the tower, Mitad del Mundo has other attractions: a planetarium, a church in which newlyweds can get married while in different hemispheres; French Expedition Museum; Ethnographic Museum, Museum of Colonial Quito; arenas with bull and cockfights, a terrace with alpacas, a coffee square. Photo exhibitions and concerts of national music and dances take place here, there are restaurants and shops for every taste. About one and a half million tourists come to Mitad del Mundo every year. You can spend the whole day here with interest... If not for one thing!

Swindle industry

The yellow line of the equator, all experiments and all activities (including weddings in different hemispheres) are a complete fake! The real equator, calculated using GPS, is located 240 meters from here! And what’s most interesting is that to get there, you need to leave the territory of the Mitad del Mundo entertainment center and pay for the entrance to the Intiñan Museum. It is on the territory of this museum that the real equator passes. And this is where real, not fake, experiments can be done.

Mitad del mundo is a really good entertainment complex, and everything would be fine, but they carefully hide from tourists that the equator here is not real! We repeatedly asked the staff how to get to the real equator, and we were constantly sent to that very famous tower. It feels like park staff have been trained to answer visitors something like: “What is the real equator? Here's the yellow line. Go take a photo." They all pretended that they didn’t understand us!)))

And only the park cleaner immediately said that to get the real equator we had to go to another museum. Apparently the cleaners do not undergo marketing training))) What’s most interesting is that in the entertainment center with the fake equator of tourists there is simply darkness! There are queues everywhere, hundreds of people take pictures on the yellow line. At the same time, there are few people on the real equator, the territory of the museum is very small, everything is somehow cozy and homely.

We asked the guide why this is? She replied that their museum cannot be covered in the media or advertised in any way. Because then the neighboring giant entertainment center will lose the frantic streams of tourists eager to visit the equator.

What happens at the equator?

The equator is an amazing place that gives rise to interesting phenomena. The equator is 21.3 kilometers farther from the center of the Earth than the poles. And in Ecuador it’s even further, because... here the equator passes through the Andes. The weather is always the same at the equator, although it is officially summer in Ecuador. Dawn here is always at 6 am, and sunset is always at 6 pm.

When you arrive at the Intiñan Museum, you can immediately take a tour in English or Spanish. The guide will tell you a lot of interesting things: about some of the peoples of Ecuador (for example, those who always walk naked and tie their penis to their stomach with a rope so that it does not dangle); about the traditions of tribes in the jungle (including mummifying the heads of enemies and wearing them around the neck as an amulet); about totems different countries; national Ecuadorian hats that can kill, and about guinea pigs that detect bad energy and squeak if you are angry. But that’s not about that now. The main part of the excursion is equatorial experiments.

Experiment 1. Egg

At the equator, all objects weigh less. Therefore, it is easier to place a chicken egg on a thin stick here than in any other place. The guide said that despite the simplicity of the procedure, only one out of 10 people can place an egg.

At the end of the excursion, everyone who completed the task receives an “Egg Balancer” certificate. By the way, we both received such a certificate.

Experiment 2. Water

Since the equator is the widest part of the Earth, the planet's rotation speed there is very high. Due to the action of centrifugal force, the water in the sink at the equator flows into the hole smoothly, without forming a funnel. In the Southern Hemisphere, water swirls clockwise, in the Northern Hemisphere, counterclockwise. You can see this in the video by looking at the leaves. This is the action of the Coriolis force.

Smart people say that this whole experiment is a scam for tourists. In fact, the Coriolis force cannot manifest itself enough for an observer to see it. IN in this case The decisive role is played by the side from which water is poured. If on the left, the water will swirl clockwise, if on the right, counterclockwise. Therefore, the demonstration of the experiment begins with draining the water at the equator: the settled water, with the plug carefully removed, will drain without a funnel. We tried to spot some kind of catch in the experiment, but we couldn’t. It seems that water is poured the same way in all cases. Watch the video!

Experiment 3. Walking in a straight line

If you stand on the equator line, close your eyes, extend your arms to the sides and start walking in a straight line, you won’t be able to do this, because... the rotational forces of different hemispheres will pull you in different directions and you will not be able to find balance. Nikita managed to go super smoothly, which means that the whole experiment was self-hypnosis...

Experiment 4: Human Power

It has been proven that at the equator a person weighs less and becomes weaker. Therefore, if, standing on the equator, a person tightly clasps his thumb and index finger, it will be very easy to unclench them, while near the equator this is no longer possible.

It really works! And it blows your mind! I can’t even believe that this is possible!

After all the experiments, sightseeing, visiting the cocoa exhibition and eating the most delicious chocolate, in the museum you can put a stamp in your passport about visiting the equator! Similar seals are also placed in the Northern and South Pole. But we didn’t have our passports with us, and the guide said that Russians never put such a stamp, because... They are afraid of border guards, and generally believe that this is illegal. While most tourists specifically collect various stamps.

How to get there?

The cheapest route from Quito to the equator consists of two buses. First from the historical center to the Ofelia stop. From there to the Mitad del mundo stop. One way fare is 90 cents per person. Travel time is 1.5 hours. If you have trouble, follow the crowd.

What is the price?

A visit to the Mitad del Mundo amusement park with a fake equator costs $3.50. If you want to go to the Equatorial Museum, which is located in the famous tower, then the price for admission to the park and museum is $6. If you also want to visit the Planetarium, then 7.5. The last option is called full pass. We took it because... they thought that the real equator included there, but this is not so. We advise you to take a ticket for 3.5 dollars, walk to the fake but historical equator, take a must-have photo and go to the real equator.

A visit to the Intiñan Museum with a real equator costs $4. This amount already includes the excursion. And even though some of the experiments, as they say, are not entirely authentic, the museum is very cool! Very impressive and interesting! You need to allocate at least two hours for it.

I will tell you about all the other interesting things that I mentioned in this article (especially about the naked tribe) later, in the following posts! Stay in touch!

Now you know that in the fabulous Universe of our distant ancestors, the Earth did not even resemble a ball. The inhabitants of Ancient Babylon imagined it as an island in the ocean. The Egyptians saw it as a valley stretched from north to south, with Egypt in the center. And the ancient Chinese at one time depicted the Earth as a rectangle... You smile, imagining such an Earth, but have you often thought about how people guessed that the Earth is not a limitless plane or a disk floating in the ocean? When I asked the guys about this, some said that people learned about the sphericity of the Earth after their first trips around the world, while others recalled that when a ship appears over the horizon, we first see the masts, and then the deck. Do these and some similar examples prove that the Earth is a sphere? Hardly. After all, you can drive around... a suitcase, and the upper parts of the ship would appear even if the Earth had the shape of a hemisphere or looked like, say,... a log. Think about this and try to depict what was said in your drawings. Then you will understand: the examples given only indicate that The earth is isolated in space and possibly spherical.

How did you know that the Earth is a ball? What helped, as I already told you, was the Moon, or rather, lunar eclipses, during which the round shadow of the Earth is always visible on the Moon. Set up a small “shadow theater”: illuminate objects of different shapes (triangle, plate, potato, ball, etc.) in a dark room and notice what shadow they create on the screen or just on the wall. Make sure that only the ball always forms a circle shadow on the screen. So, the Moon helped people learn that the Earth is a ball. Scientists in Ancient Greece (for example, the great Aristotle) ​​came to this conclusion back in the 4th century BC. But for a very long time, the “common sense” of man could not come to terms with the fact that people live on the ball. They couldn’t even imagine how it was possible to live on the “other side” of the ball, because the “antipodes” located there would have to walk upside down all the time... But wherever a person is on the globe, everywhere a stone thrown up will be under the influence of force gravity of the Earth to fall down, that is, to the earth's surface, and if it were possible, then to the center of the Earth. In fact, people, of course, nowhere except circuses and gyms have to walk upside down and upside down. They walk normally anywhere on Earth: the earth’s surface is under their feet, and the sky is above their heads.

Around 250 BC, Greek scientist Eratosthenes for the first time measured the globe quite accurately. Eratosthenes lived in Egypt in the city of Alexandria. He guessed to compare the height of the Sun (or its angular distance from a point above his head, zenith, which is called - zenith distance) at the same point in time in two cities - Alexandria (in northern Egypt) and Siena (now Aswan, in southern Egypt). Eratosthenes knew that on the day of the summer solstice (June 22) the Sun was at noon illuminates the bottom of deep wells. Therefore, at this time the Sun is at its zenith. But in Alexandria at this moment the Sun is not at its zenith, but is 7.2° away from it. Eratosthenes obtained this result by changing the zenith distance of the Sun using his simple goniometric instrument - the scaphis. This is simply a vertical pole - a gnomon, fixed at the bottom of a bowl (hemisphere). The scaphis is installed so that the gnomon takes a strictly vertical position (directed to the zenith). The pole illuminated by the sun casts a shadow on the inner surface of the scaphis, divided into degrees. So at noon on June 22 in Siena the gnomon does not cast a shadow (the Sun is at its zenith, its zenith distance is 0°), and in Alexandria the shadow from the gnomon, as can be seen on the scaphis scale, marked a division of 7.2°. In the time of Eratosthenes, the distance from Alexandria to Syene was considered to be 5,000 Greek stadia (approximately 800 km). Knowing all this, Eratosthenes compared an arc of 7.2° with the entire circle of 360° degrees, and a distance of 5000 stadia with the entire circumference of the globe (let's denote it by the letter X) in kilometers. Then from the proportion

it turned out that X = 250,000 stadia, or approximately 40,000 km (imagine, this is true!).

If you know that the circumference of a circle is 2πR, where R is the radius of the circle (and π ~ 3.14), knowing the circumference of the globe, it is easy to find its radius (R):

It is remarkable that Eratosthenes was able to measure the Earth very accurately (after all, today it is believed that the average radius of the Earth 6371 km!).

But why is it mentioned here? average radius of the Earth, Aren't all the radii of a ball the same? The fact is that the figure of the Earth is different from the ball. Scientists began to guess about this back in the 18th century, but it was difficult to find out what the Earth really was like - whether it was compressed at the poles or at the equator. To understand this, the French Academy of Sciences had to equip two expeditions. In 1735, one of them went to carry out astronomical and geodetic work in Peru and did this in the equatorial region of the Earth for about 10 years, and the other, Lapland, worked in 1736-1737 near the Arctic Circle. As a result, it turned out that the arc length of one degree of the meridian is not the same at the Earth's poles and at its equator. The meridian degree turned out to be longer at the equator than at high latitudes (111.9 km and 110.6 km). This can only happen if the Earth is compressed at the poles and is not a ball, but a body similar in shape to spheroid. At the spheroid polar radius is smaller equatorial(the polar radius of the earth's spheroid is almost shorter than the equatorial radius 21 km).

It is useful to know that the great Isaac Newton (1643-1727) anticipated the results of the expeditions: he correctly concluded that the Earth is compressed, which is why our planet rotates around its axis. In general, the faster a planet rotates, the greater its compression should be. Therefore, for example, the compression of Jupiter is greater than that of the Earth (Jupiter manages to rotate around its axis in relation to the stars in 9 hours 50 minutes, and the Earth only in 23 hours 56 minutes).

And further. The true figure of the Earth is very complex and differs not only from a sphere, but also from a spheroid rotation. True, in this case we are talking about a difference not in kilometers, but... meters! Scientists are still engaged in such a thorough refinement of the Earth’s figure to this day, using for this purpose specially conducted observations from artificial Earth satellites. So it is quite possible that someday you will have to take part in solving the problem that Eratosthenes took on a long time ago. This is something that people really need.

What is the best figure for you to remember on our planet? I think that for now it is enough if you imagine the Earth in the form of a ball with an “additional belt” put on it, a kind of “splash” on the equator region. Such a distortion of the Earth’s figure, turning it from a sphere into a spheroid, has considerable consequences. In particular, due to the attraction of the “additional belt” by the Moon, the earth’s axis describes a cone in space in about 26,000 years. This movement of the earth's axis is called precessional. As a result, the role North Star, which now belongs to α Ursa Minor, is alternately played by some other stars (in the future it will become, for example, α Lyrae - Vega). Moreover, due to this ( precessional) movement of the earth's axis Zodiac signs more and more do not coincide with the corresponding constellations. In other words, 2000 years after the Ptolemaic era, the “sign of Cancer,” for example, no longer coincides with the “constellation Cancer,” etc. However, modern astrologers try not to pay attention to this...