A huge flat circle: this is exactly how they saw the earth’s surface when they made their travels.
However, ideas about the shape of our planet have changed. About two thousand years ago, ancient Greek scientists already came to the conclusion that the Earth is spherical. It is easy to be convinced that the surface of the Earth is convex by watching a ship approaching by sea from the shore: first, its masts and pipes appear from behind the horizon, then the entire hull gradually becomes visible, as if the ship is rising from somewhere below. In order to see as far as possible in open areas, we climb onto a high object - a tree, the roof of a house, a hill, because the horizon expands with increasing height of the observation site.
The spherical shape of the Earth is especially clearly visible in space images.
Shape of the Earth
Dimensions of the Earth
Specially made measurements provide accurate information about the size of the Earth. The surface area of our planet is 510,000,000 km2. The distance from the center of the Earth to the equator is 6378 km, and to the poles - 6356 km, that is, our planet is slightly flattened at the poles. In order to travel around the Earth on a fast train, it will take about a month, since the circumference of our planet is 40,000 km.
Globe - model of the globe
This is a semblance of a globe, from which you can get an idea of the shape of our planet. The globe is always oriented so that the North Pole is at the top and the South Pole is at the bottom. The axis of rotation is tilted in the same way as the waxing axis of the Earth. The outlines of continents, oceans, seas, their relative locations and sizes are clearly visible on the globe. However, all images of geographical objects on a regular school globe are very small. The largest globe on Earth is considered to be a globe with a diameter of 10 m (its weight is 30 tons), which is located in. On such a globe, the surface of the Earth is depicted in sufficient detail, however, due to its size, it is very inconvenient to handle.
It is much more practical to deal with, which are flat images of parts of the earth's surface. Geographical objects are shown on maps much larger than on a globe. In addition, the cards are convenient to carry with you. However, when creating maps, they encounter another difficulty: any image of the surface of a ball on a plane turns out to be deformed and contains some error.
The problem of the shape of the Earth has concerned people for many millennia. This is one of the important questions not only for geography and ecology, but also for astronomy, philosophy, physics, history and even literature. Many works of scientists from all eras, especially Antiquity and the Enlightenment, are devoted to this issue.
Scientists' hypotheses about the shape of the Earth
So Pythagoras in the 6th century BC already believed that our planet has the shape of a ball. His statement was shared by Parmenides, Anaximander of Miletus, Eratosthenes and others. Aristotle conducted various experiments and was able to prove that the Earth has a round shape, since during eclipses of the Moon the shadow is always in the shape of a circle. Considering that at that time there were discussions between supporters of absolutely two opposing points of view, some of which argued that the earth was flat, others that it was round, the theory of sphericity, although it was accepted by many thinkers, needed significant revision.
Newton stated that the shape of our planet differs from that of a sphere. He was inclined to believe that it was more likely an ellipsoid, and to prove this, he conducted various experiments. Further, the works of Poincaré and Clairaut, Huygens and d’Alembert were devoted to the shape of the earth.
Modern concept of planet shape
Many generations of scientists have conducted fundamental research to determine the shape of the Earth. Only after the first flight into space was it possible to dispel all the myths. Now the accepted point of view is that our planet has the shape of an ellipsoid, and it is far from an ideal shape, flattened at the poles.
For various research and educational programs, a model of the earth has been created - a globe, which has the shape of a ball, but this is all very conditional. On its surface it is difficult to depict absolutely all geographical objects of our planet in scale and proportion. As for the radius, a value of 6371.3 kilometers is used for various purposes.
For problems of astronautics and geodesy, in order to describe the figure of the planet, the concept of an ellipsoid of revolution or geoid is used. However, at different points the earth differs from the geoid. To solve various problems, various models of earth ellipsoids are used in the future, for example, a reference ellipsoid.
Thus, the shape of the planet is a complex issue even for modern science, which has worried people since ancient times. Yes, we can fly into space and see the shape of the Earth, but mathematical and other calculations are not yet enough to accurately depict the figure, since our planet is unique and does not have such a simple shape as geometric bodies.
Near the Library of Alexandria, during the position of the Sun above Siena at its zenith, he was able to measure the length of the Earth's meridian and calculate the radius of the Earth. It was Newton who first showed that the shape of the Earth should be different from that of a sphere.
It is known that the planet was formed under the influence of two forces - the force of mutual attraction of its particles and the centrifugal force arising from the rotation of the planet around its axis. Gravity is the resultant of these two forces. The degree of compression depends on the angular velocity of rotation: the faster the body rotates, the more it is flattened at the poles.
Rice. 2.1. Earth Rotation
The concept of the figure of the Earth can be interpreted differently depending on what requirements are imposed on the accuracy of solving certain problems. In some cases, the Earth can be taken as a plane, in others - as a ball, in others - as a biaxial ellipsoid of rotation with low polar compression, in fourths - as a triaxial ellipsoid.
Rice. 2.2. Physical surface of the Earth ( view from space)
Land makes up approximately one third of the Earth's total surface. It rises above sea level by an average of 900 - 950 m. Compared to the radius of the Earth (R = 6371 km), this is a very small value. Since most of the Earth's surface is occupied by seas and oceans, the shape of the Earth can be taken to be a level surface that coincides with the undisturbed surface of the World Ocean and is mentally continued under the continents. At the suggestion of the German scientist Listing, this figure was called geoid
.
A figure bounded by a level surface coinciding with the surface of the water of the World Ocean in a calm state, mentally continued under the continents, is called geoid .
The World Ocean refers to the surfaces of seas and oceans connected to each other.
The surface of the geoid is perpendicular to the plumb line at all points.
The shape of the geoid depends on the distribution of masses and densities in the Earth's body. It does not have an exact mathematical expression and is practically indeterminable, and therefore in geodetic measurements, instead of the geoid, its approximation - a quasi-geoid - is used. Quasigeoid, unlike the geoid, is uniquely determined from the results of measurements, coincides with the geoid on the territory of the World Ocean and is very close to the geoid on land, deviating only a few centimeters on flat terrain and no more than 2 meters in high mountains.
To study the figure of our planet, first determine the shape and dimensions of a certain model, the surface of which is relatively well studied geometrically and most fully characterizes the shape and dimensions of the Earth. Then, taking this conditional figure as the original one, the heights of the points are determined relative to it. To solve many geodesy problems, the Earth model is taken Ellipsoid of revolution (spheroid).
The direction of the plumb line and the direction of the normal (perpendicular) to the surface of the ellipsoid at points on the earth’s surface do not coincide and form an angle ε , called deviation of the plumb line . This phenomenon is due to the fact that the density of masses in the Earth’s body is not the same and the plumb line deviates towards denser masses. On average, its value is 3 - 4", and in places of anomalies it reaches tens of seconds. The actual sea level in different regions of the Earth will deviate by more than 100 meters from the ideal ellipsoid.
Rice. 2.3. The relationship between the surfaces of the geoid and the earth's ellipsoid.
1) the world ocean; 2) earth's ellipsoid; 3) plumb lines; 4) the body of the Earth; 5) geoid
To determine the size of the earth's ellipsoid on land, special degree measurements were taken (the distance along a meridian arc of 1º was determined). Over the course of a century and a half (from 1800 to 1940), various sizes of the earth's ellipsoid were obtained (ellipsoids of Delembert (d'Alembert), Bessel, Hayford, Clark, Krasovsky, etc.).
Delembert's ellipsoid has only historical significance as the basis for establishing the metric system of measures (on the surface of Delembert's ellipsoid, a distance of 1 meter is equal to one ten-millionth of the distance from the pole to the equator).
The Clark ellipsoid is used in the USA, Latin America, Central America and other countries. In Europe, the Hayford ellipsoid is used. It was also recommended as an international one, but the parameters of this ellipsoid were obtained from measurements made only in the United States, and, moreover, contain large errors.
Until 1942, the Bessel ellipsoid was used in our country. In 1946, the dimensions of Krasovsky’s earth ellipsoid were approved for geodetic work on the territory of the Soviet Union and are still in effect on the territory of Ukraine.
The ellipsoid, which is used by a given state, or a separate group of states, to carry out geodetic work and project points on the physical surface of the Earth onto its surface is called reference ellipsoid.
The reference ellipsoid serves as an auxiliary mathematical surface to which the results of geodetic measurements on the earth's surface are led. The most successful mathematical model of the Earth for our territory in the form of a reference ellipsoid was proposed by prof. F. N. Krasovsky. The geodetic coordinate system Pulkovo-1942 (SK-42), which was used in Ukraine to create topographic maps from 1946 to 2007, is based on this ellipsoid.
Dimensions of the earth's ellipsoid according to Krasovsky
Semi-minor axis (polar radius) |
|
Semimajor axis (equatorial radius) |
|
Average radius of the Earth taken as a sphere |
|
Polar compression (ratio of semi-axis difference to semi-major axis) |
|
Earth's surface area |
510083058 km² |
Meridian length |
|
Equator length |
|
Arc length 1° along the meridian at latitude 0° |
|
Arc length 1° along the meridian at latitude 45° |
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Arc length 1° along the meridian at latitude 90° |
When introducing the Pulkovo coordinate system and the Baltic height system, the Council of Ministers of the USSR entrusted the General Staff of the Armed Forces of the USSR and the Main Directorate of Geodesy and Cartography under the Council of Ministers of the USSR with recalculating the triangulation and leveling network into a single system of coordinates and heights, completed before 1946, and obliged them to complete this work within a 5-year period. Control over the reissue of topographic maps was entrusted to the General Staff of the Armed Forces of the USSR, and nautical maps to the Main Headquarters of the Naval Forces.
On January 1, 2007, a USK-2000
- Ukrainian coordinate system
instead of SK-42. The practical value of the new coordinate system is the ability to effectively use global navigation satellite systems in topographic and geodetic production, which have a number of advantages compared to traditional methods.
The author of this textbook has no information that in Ukraine the coordinates of SK-42 were recalculated into USK-2000 and new topographic maps were published. On educational topographic maps published in 2010 by the State Research and Production Enterprise “Cartography”, the inscription “Coordinate system 1942” still remains in the upper left corner.
The 1963 coordinate system (SK-63) was a derivative of the previous state coordinate system of 1942 and had certain connection parameters with it. To ensure secrecy, real data was artificially distorted in SK-63. With the advent of powerful computer technology for high-precision determination of communication parameters between different coordinate systems, this coordinate system lost its meaning in the early 80s. It should be noted that SK-63 was canceled by a decision of the USSR Council of Ministers in March 1989. But subsequently, given the large volumes of accumulated geospatial data and cartographic materials (including the results of land management work during the USSR), the period of its use was extended until all data was transferred to the current state coordinate system.
For satellite navigation, the three-dimensional coordinate system WGS 84 (World Geodetic System 1984) is used. Unlike local systems, it is a single system for the entire planet. WGS 84 determines coordinates relative to the Earth's center of mass, the error is less than 2 cm. In WGS 84, the prime meridian is considered to be the IERS Reference Meridian. It is located 5.31″ east of the Greenwich meridian. The basis is a spheroid with a larger radius - 6,378,137 m (equatorial) and a smaller one - 6,356,752.3142 m (polar). Differs from the geoid by less than 200 m.
The structural features of the Earth's figure are fully taken into account in the mathematical processing of high-precision geodetic measurements and the creation of state geodetic reference networks. Due to the smallness of the compression (the ratio of the difference between the major and equatorial semi-axis ( A) of the earth's ellipsoid and the polar semi-minor axis ( b) to the semi-major axis [ a-b]/b) ≈ 1:300) when solving many problems, the figure of the Earth can be taken with sufficient accuracy for practical purposes sphere
, equal in volume to the earth's ellipsoid
. The radius of such a sphere for the Krasovsky ellipsoid is R = 6371.11 km.
2.2. BASIC LINES AND PLANES OF THE EARTH'S ELLIPSOID
When determining the position of points on the surface of the Earth and on the surface of the Earth's ellipsoid, some lines and planes are used.
It is known that the points of intersection of the axis of rotation of the earth's ellipsoid with its surface are poles, one of which is called the North Rs, and the other - South Ryu(Fig. 2.4).
Rice. 2.4. The main lines and planes of the earth's ellipsoid
Sections of the earth's ellipsoid by planes perpendicular to its minor axis form a trace in the form of circles, which are called parallels.
Parallels have radii of different sizes. The closer the parallels are to the center of the ellipsoid, the larger their radii. The parallel with the largest radius equal to the semi-major axis of the earth's ellipsoid is called equator
. The plane of the equator passes through the center of the earth's ellipsoid and divides it into two equal parts: the Northern and Southern Hemispheres.
The curvature of the ellipsoid's surface is an important characteristic. It is characterized by the radii of curvature of the meridian section and the section of the first vertical, which are called the main sections
Sections of the surface of the earth's ellipsoid by planes passing through its minor axis (axis of rotation) form a trace in the form of ellipses, which are called meridian sections
.
In Fig. 2.4 straight CO", perpendicular to the tangent plane QC" at the point of contact WITH, called normal
to the surface of the ellipsoid at this point. Each normal to the surface of the ellipsoid always lies in the meridian plane, and therefore intersects the axis of rotation of the ellipsoid. Normals to points lying on the same parallel intersect the minor axis (axis of rotation) at the same point. Normals to points located on different parallels intersect with the axis of rotation at different points. The normal to a point located on the equator lies in the equatorial plane, and the normal at the pole point coincides with the axis of rotation of the ellipsoid.
The plane passing through the normal is called normal plane
, and the trace from the section of the ellipsoid by this plane is normal
cross section
. An infinite number of normal sections can be drawn through any point on the surface of an ellipsoid. The meridian and the equator are special cases of normal sections at a given point of the ellipsoid.
Normal plane perpendicular to the meridian plane at a given point WITH, called plane of the first vertical
, and the trace along which it intersects the surface of the ellipsoid is a section of the first vertical (Fig. 2.4).
The relative position of the meridian and any normal section passing through the point WITH(Fig. 2.5) on a given meridian, is determined on the surface of the ellipsoid by the angle A, formed by the meridian of a given point WITH and normal section.
Rice. 2.5. Normal section
This angle is called geodetic azimuth
normal section. It is measured from the northern direction of the meridian clockwise from 0 to 360°.
If we take the Earth to be a ball, then the normal to any point on the surface of the ball will pass through the center of the ball, and any normal plane forms a trace on the surface of the ball in the form of a circle, which is called a great circle.
2.3. METHODS FOR DETERMINING THE FIGURE AND DIMENSIONS OF THE EARTH
The following methods were used to determine the shape and size of the Earth:
Astronomical - geodetic method
Determining the shape and size of the Earth is based on the use of degree measurements, the essence of which boils down to determining the linear value of one degree of meridian arc and parallel at different latitudes. However, direct linear measurements of a significant extent on the earth's surface are difficult; its unevenness significantly reduces the accuracy of the work.
Triangulation method.
High accuracy in measuring long distances is ensured by the use of the triangulation method, developed in the 17th century. Dutch scientist W. Snellius (1580 - 1626).
Triangulation work to determine the arcs of meridians and parallels was carried out by scientists from different countries. Back in the 18th century. it was found that one degree of arc of the meridian at the pole is longer than at the equator. Such parameters are typical for an ellipsoid compressed at the poles. This confirmed I. Newton's hypothesis that the Earth, in accordance with the laws of hydrodynamics, should have the shape of an ellipsoid of rotation, flattened at the poles.
Geophysical (gravimetric) method
It is based on the measurement of quantities characterizing the earth's gravity field and their distribution on the earth's surface. The advantage of this method is that it can be used in the waters of seas and oceans, i.e. where the capabilities of the astronomical-geodetic method are limited. Data from measurements of the gravity potential made on the surface of the planet make it possible to calculate the compression of the Earth with greater accuracy than using the astronomical-geodetic method.
Gravimetric observations began in 1743 by the French scientist A. Clairaut (1713 - 1765). He assumed that the surface of the Earth has the form of a spheroid, that is, the figure that the Earth would take if it were in a state of hydrostatic equilibrium under the influence only of the forces of mutual gravity of its particles and the centrifugal force of rotation about a constant axis. A. Clairaut also suggested that the body of the Earth consists of spheroidal layers with a common center, the density of which increases towards the center.
Space method
The development of the space method and the study of the Earth is associated with the exploration of outer space, which began with the launch of the Soviet artificial Earth satellite (AES) in October 1957. Geodesy was faced with new tasks related to the rapid development of astronautics. These include monitoring satellites in orbit and determining their spatial coordinates at a given point in time. The identified deviations of real satellite orbits from the precalculated ones, caused by the uneven distribution of masses in the earth's crust, make it possible to clarify the idea of the Earth's gravitational field and, as a result, its figure.
Questions and tasks for self-control
For what purposes are data on the shape and size of the Earth used?
By what signs did ancient people determine that the Earth has a spherical shape?
What figure is called the geoid?
What shape is called an ellipsoid?
What figure is called the reference ellipsoid?
What are the elements and dimensions of Krasovsky's ellipsoid?
Name the main lines and planes of the earth's ellipsoid.
What methods are used to determine the shape and size of the Earth?
Give a brief description of each method.
The generally accepted statement that ancient scientists considered our Earth to be flat is not entirely true. Of course, someone thought it was flat, but in fact there were several versions, including one that the Earth is a sphere. Today, it would seem, all the i’s are dotted and no one doubts that the Earth is a ball revolving around the Sun.
No matter how it is. Whether for fun or for PR, or maybe for religious reasons, the world is again split on this issue into two opposing camps. Are you surprised? If someone comes up to you and claims that the Earth is flat, will you twist it at your temple? Oh well. The fact that the Earth is a ball (to be precise, a geoid) and revolves around the Sun is a generally accepted theory and, it seemed, beyond doubt? It wasn’t there...
Which Earth is it: round or flat?
On the one hand, modern science claims that the Earth is round, and on the other... At the head, perhaps, is the Flat Earth Society. The main goal is to prove that the Earth is flat, and the governments of all countries are in a conspiracy and in various ways mislead about the sphericity of the Earth, hiding the fact that the Earth is flat.
The Flat Earth Society still has its adherents.
The basic concepts of the flat earth society are:
The Earth is a flat disk, 40,000 kilometers in diameter, centered near the North Pole.
The Sun and Moon and stars move above the surface of the Earth.
Gravity is denied. The acceleration due to gravity occurs because the Earth is moving upward with an acceleration of 9.8 m/s². Due to the curvature of space-time, this can last indefinitely.
South Polenet. Antarctica is actually the icy edge of our disk - a wall encircling our world.
All photographs of the Earth from space are fakes.
The distance between objects in the southern hemisphere is actually much greater. The fact that flights between them occur much faster than should be according to the flat Earth map can be explained simply - the airliner crews are involved in a conspiracy.
The Sun is something like a powerful searchlight 51 km in diameter, which circles above the Earth at a distance of 4800 km and illuminates it.
Everything that happens is an experiment on us.
All scientific institutes deliberately lie that the Earth is spherical, etc.
The government also lies - it works for its masters - the reptilians.
There were no flights into space, and there’s nothing to say about the Moon, it’s all a hoax.
All videos about space flights were filmed on Earth.
And off we go. Gradually the world is splitting into two halves. One goes to live on a round and spherical Earth, the other – also round, but flat.
Both sides provide “irrefutable” evidence of their vision of the shape of the earth.
Here are some of the most interesting facts of the universe from the lips of both opponents.
The earth is flat because:
IN THE AREA OF VISIBILITY THE HORIZONT LINE IS FLAT
Flat-Earth Evidence: Take any photograph where the horizon line is flat, not rounded. Ball-earth refutation: to see the real curves of the horizon line or plane in the frame, you need a much greater distance from the shooting point from the surface of the earth. This is clearly visible in photographs from space. Flat earth answer: all pictures from space are fakes from NASA and the like. Space doesn't exist. |
THE BIBLE TALKS ABOUT A FLAT EARTH
Flat earth proofs: In many descriptions in the Bible, the Earth is flat earth.
(Daniel 4:7, 8): “The visions of my head on my bed were as follows: I saw, behold, a very tall tree in the middle of the earth. This tree was large and strong, and its height reached to the sky, and it was apparently up to ends of the whole earth » -
- This expression only applies to flat earth.
Ball-earth rebuttal:(published taking into account the opinions of fundamentalist Christians):
It should be immediately clarified that the Bible is not a scientific work aimed at explaining the structure of the universe. In the Holy Scriptures, this is done figuratively and in a language understandable to the common people, based on the knowledge that the people had in those days. However, when carefully read and interpreted, the Bible does not contradict modern science and does not indicate that the Earth is not spherical.
In this case, the dream of Nebuchadnezzar, the king of the Neo-Babylonian kingdom, who reigned from September 7, 605 to October 7, 562 BC, is described. e.. The tree in the dream, as it turned out from Daniel’s interpretation of the dream, is Nebuchadnezzar himself. It is correct to consider the edge of the Earth to be the border of the Neo-Babylonian kingdom, for a simple reason: Nebuchadnezzar never ruled the entire Earth. Moreover, it speaks of vision, and not of direct observation.
Flat earth:
(Isaiah 42:5): “Thus says the Lord God, who created the heavens and their expanses, who spread out the earth with its products.” This can only be done with a flat earth.
Ball-earth rebuttal:
This description refers to what are currently called continents. Modern science, with minor reservations, considers the continents to be flat. If this action is considered applicable to a plane, this does not in any way indicate that the entire Earth is also flat.
Flat earth:There is no continuation of dialogue from the appender yet
(Matthew 4:8): “Again the devil takes Him [Jesus] to a very high mountain and shows Him all the kingdoms of the world and their glory.”
This is only possible if the Earth is flat.
Ball-earth rebuttal(from Bible scholars and scholars):
All the highest mountains on Earth are known. Climbers have climbed everything, and more than once. Unfortunately, it is not possible to examine all the “kingdoms” with any of them, and the reason is not at all that the Earth is round (this is not a hindrance), but because it is impossible to examine anything at such a distance . But a modern person can watch “all the kingdoms of the world” on a computer monitor or smartphone. However, Satan's capabilities and abilities far exceed those of humans. In what way he showed the kingdoms and why the high mountain was needed, we do not know.
The most interesting thing is that theoretically this is how the entire Earth can be viewed. Don't be surprised, this is really true. This phenomenon is called diffraction. Under certain conditions, we see the horizon line much further than theoretically we should see it. This is how mirages arise. Of course, in real life the chances of seeing something like this are incredibly small. After all, this requires a certain air temperature, humidity, transparency and, possibly, something else. There is even less chance of seeing the whole Earth. And it’s absolutely insignificant - to view what you want. But who said that the devil does not know how to use this phenomenon? Showing such mirage pictures to Jesus would be a very effective way to influence his human spiritual-sensual nature in order to achieve admiration from him. On the other hand, here we can also talk about vision without direct observation.
Flat earth:There is no continuation of dialogue from the appender yet
(Job 38:12,13): “Did you ever give orders to the morning in your life and show the dawn its place so that it would embrace ends of the earth and shook off the wicked..."
(Job. 37:3 )"Under the whole sky its roar, and its shine - to the ends of the earth ."
The edges can only have a plane.
Ball-earth rebuttal:(from Bible scholars and scholars):
The Lord speaks to Job about the unshakable order of alternation of day and night established by Him. It is figuratively said that the dawn disperses darkness and stops the deeds of the wicked committed at night. The expression “end of the earth” is also used by those who are well aware of the spherical shape of the Earth.
There are other references in the Bible to the edges and corners of the Earth, which can be interpreted in different ways: for example, that these are the edges of continents or countries. In addition, the Bible itself confirms that the word “earth” means dry land:
(Life 1:10 ) And God called the dry land earth , and called the collection of waters seas.
Therefore, it is impossible to accept these scriptures as proof that the Earth is flat.
Flat earth:There is no continuation of dialogue from the appender yet
BEDFORD EXPERIMENT
It was carried out in 1838 by Samuel Rowbotham. This experiment is considered the most reliable evidence.
The essence of the experiment is extremely simple. Rowbotham found a flat area of about 10 km (6 miles) on the Bedford River. I installed the telescope at a height of 20 inches (50.8 cm) from the surface of the water and began to watch the receding boat with a five-meter mast.
The mast was visible throughout the boat's movement. On the basis of which Rowbotham stated that the Earth is flat.
If the Earth were round, the mast should have disappeared from view.
Ball-earth rebuttal:
Lifting horizon in this case it happened due to the phenomenon of refraction. Due to positive refraction, the visible horizon has risen. As a result, its geographic range increased compared to its geometric range. This made it possible to see objects hidden by the curvature of the Earth. At normal temperatures, the horizon rise is 6-7%.
For reference: If the temperature increases excessively the visible horizon can rise to the true mathematical horizon. At the same time, the earth's surface will visually straighten. The earth will become flat, to the delight of flat-earthers. Of course, only visually. The visibility range under these conditions will become infinitely large. The radius of curvature of the beam can become equal to the radius of the globe.
For reference: The discoverer of light refraction is considered to be the Italian physicist and astronomer Grimaldi Francesco Maria (1618-1663)
Naturally, Samuel Rowbotham was well aware of the phenomena of refraction. And it is quite logical that the published book describing experiments proving that the Earth is flat did not arouse any interest among scientists. But there were many adherents. One of Hemplein’s followers even placed a bet of 500 pounds (not a small amount at that time) that he would allegedly prove to any opponent that the Earth was flat. And such an opponent was found. It was the scientist Alfred Wallace. Of course, he knew perfectly well what he was doing. The experiment was carried out in the same valley. But Wallace changed the observation slightly. He used an intermediate point - a bridge, on which a circle was fixed. A horizontal line was placed at the end point. The telescope, circle and line were at the same height relative to the surface of the water. If the Earth were flat, a line would be visible through the circle at its center. Naturally, this did not happen. However, Hamplen refused to pay the due amount and called Wallace a liar and a forger.
So what is the Earth like?
Isn't it time to tell the true story that Magellan simply swam in a circle, not around the Earth? Cook sailed along the edge of the Earth in search of Antarctica. And by the way, he was right: Antarctica does not exist! Kruzenshtern also had good reason to doubt it when he discovered Antarctica. After all, he just ran into an icy wall that was created to prevent the oceans from flowing out. It is not clear, of course, how he managed to get around our Earth’s disk (yes, a disk, let’s call a spade a spade) in 751 days. Again conspiracy and falsification! He didn’t put anything on the map and didn’t go anywhere, he probably drank beer somewhere in Australia, and the maps were given to him ready-made, drawn at NASO. NASO is a special organization that, for our billions, fools us, draws cool pictures of space, makes viewing programs for the supposedly round Earth, and films hoax shows of flights into space and to the Moon. Governments are in cahoots, all scientists are in cahoots, pilots are in cahoots, the police are also aware - collusion, all smart people are also in cahoots. In short, everything is in conspiracy against honest people who understand the essence of the true universe and, finally, with the advent of the Internet, are ready to open the eyes of those who are not yet in the know.
This is roughly what this serious problem looks like today. So what kind of Earth do we actually live on? If you know any facts, please report them in the comments. Perhaps you will be able to find inaccuracies in the article or the need to supplement it, we will also comment. And we will certainly make an addition, and possibly a continuation, taking into account all your comments and wishes. Please behave correctly, do not send your participants to the third grade of high school or to a psychiatrist, or twist your finger to your temple. Checked - doesn't work. Only strong arguments and evidence of a flat or spherical Earth will help save the situation.
Earth, with an average distance of 149,597,890 km from the Sun, is the third and one of the most unique planets in the solar system. It formed about 4.5-4.6 billion years ago and is the only planet known to support life. This is due to a number of factors, such as atmospheric composition and physical properties such as the presence of water, which occupies about 70.8% of the planet's surface, allowing life to flourish.
Earth is also unique in that it is the largest of the terrestrial planets (Mercury, Venus, Earth and Mars), which are composed of a thin layer of rock, compared to the gas giants (Jupiter, Saturn, Neptune and Uranus). Based on mass, density, and diameter, Earth is the fifth largest planet in the entire solar system.
Dimensions of the earth: mass, volume, circumference and diameter
Terrestrial planets (Mercury, Venus, Earth and Mars)
As the largest of the terrestrial planets, Earth has an estimated mass of 5.9722±0.0006×10 24 kg. Its volume is also the largest of these planets at 1.08321×10¹² km³.
In addition, our planet is the densest of the terrestrial planets, as it consists of a crust, mantle and core. The Earth's crust is the thinnest of these layers, while the mantle makes up 84% of the Earth's volume and extends 2,900 km below the surface. The core is the component that makes the Earth the densest. It is the only terrestrial planet with a liquid outer core surrounding a solid, dense inner core.
The average density of the Earth is 5.514×10 g/cm³. Mars, the smallest of the Earth-like planets in the solar system, has only about 70% of the density of Earth.
Earth is also classified as the largest of the terrestrial planets in terms of circumference and diameter. The equatorial circumference of the Earth is 40,075.16 km. It is slightly smaller between the North and South Poles - 40,008 km. The diameter of the Earth at the poles is 12,713.5 km, and at the equator - 12,756.1 km. By comparison, the largest planet in the solar system, Jupiter, has a diameter of 142,984 km.
Shape of the Earth
Hammer-Aitov projection
The circumference and diameter of the Earth are different because its shape is an oblate spheroid or ellipsoid instead of a true sphere. The planet's poles flatten slightly, resulting in a bulge at the equator and therefore a larger circumference and diameter.
The Earth's equatorial bulge is 42.72 km and is caused by the planet's rotation and gravity. Gravity itself causes planets and other celestial bodies to collapse and form a sphere. This is due to the fact that it pulls the entire mass of the object as close as possible to the center of gravity (the earth's core in this case).
As the planet rotates, the sphere is distorted by centrifugal force. It is the force that causes objects to move outward from their center of gravity. When the Earth rotates, the centrifugal force is greatest at the equator, so it causes a slight outward bulge, giving that area a larger circumference and diameter.
Local topography also plays a role in the shape of the Earth, but on a global scale it is minor. The greatest differences in local topography around the world are Mount Everest, the highest point above sea level at 8,848 m, and the Mariana Trench, the lowest point below sea level at 10,994±40 m. This difference is only about 19 km, which is very insignificant on a planetary scale. If we consider the equatorial bulge, the highest point in the world and the place farthest from the center of the Earth is the summit of the Chimborazo volcano in Ecuador, which is the highest peak near the equator. Its height is 6,267 m.
Geodesy
To properly study the size and shape of the Earth, geodesy is used, a branch of science responsible for measuring the size and shape of the Earth through surveys and mathematical calculations.
Throughout history, geodesy has been an important branch of science as early scientists and philosophers attempted to determine the shape of the Earth. Aristotle is the first person credited with attempting to calculate the size of the Earth and is therefore an early surveyor. This was followed by the Greek philosopher Eratosthenes, who estimated the circumference of the Earth at 40,233 km, which is only slightly larger than the current measurement.
To explore the Earth and use geodesy, researchers often refer to the ellipsoid, geoid, and reference ellipsoid. An ellipsoid is a theoretical mathematical model that shows a smooth, simplified representation of the Earth's surface. It is used to measure distances on a surface without taking into account factors such as changes in elevation and landform. Given the reality of the earth's surface, surveyors use the geoid, a model of the planet that is constructed using global mean sea level and therefore takes elevation differences into account.
The basis of geodesy today is data that acts as guidelines for global geodetic work. Today, technologies such as satellites and global positioning systems (GPS) allow surveyors and other scientists to make extremely accurate measurements of the Earth's surface. In fact, they are so precise that they can measure the Earth's surface down to centimeters, providing the most accurate measurements of the Earth's size and shape.
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