The history of the shape and movement of the earth, the process of human understanding of the shape

The shape of the earth, hence the name, is spherical. However, the understanding of the spherical shape has gone through a considerable process. In the fifth and sixth centuries B.C., ancient Greek philosophers believed that the earth was spherical based on the concept that the sphere was the most perfect.

In 350 B.C., the ancient Greek scholar Aristotle observed a lunar eclipse and scientifically demonstrated for the first time that the earth is a sphere based on the fact that the earth's shadow is a circle. Hui Shi, a philosopher during the Warring States period in China, has long put forward the idea that the earth is round. In 1591, five ships led by the Portuguese navigator Magellan completed the first voyage around the earth in three years, thus directly confirming that the earth is round.

Since then, people have unanimously referred to the world we live in as "Earth". After the 50s of the 20th century, the development of science and technology needs to be rapid, and a variety of ways have been opened up for geodesy, high-precision microwave ranging, laser ranging, especially artificial satellites in the sky, more accurately measured the size and shape of the earth. The Earth, to be exact, is a triaxial ellipsoid.

Human understanding of the shape of the earth has gone through a long process of imagining, speculating, verifying, witnessing, and measuring. The ancients relied on imagination to think that the earth is "a place where the sky is round", and there is a saying that "the sky is round like a cover, and the place is like a chess game". The success of Magellan's fleet around the world in the early 16th century proved that the earth was a sphere.

Also known as the Blue Star, the third planet, the Earth's surface is roughly a land mass of continents and islands, with the rest covered by water.

The Earth has a very long history, the original Earth was formed about 6.5 billion years ago, and the original surface of the Earth was an "ocean" of magma.

With a roughly ellipsoidal shape and a slight uplift near the equator, the Earth is the only known celestial body that supports life.

The shape of the Earth is an irregular spheroid with slightly flattened poles and slightly bulging equators.

The average radius of the earth is 6,371 kilometers, the maximum circumference is about 40,000 kilometers, and the surface area is about 100 million square kilometers. In fact, scientists have also debated the appearance of the earth. The British physicist Isaac Newton proposed that the Earth could not be a positive sphere because of its rotation on its axis.

Introduction to Earth. Earth is the third planet in the solar system from the inside and outside, and it is also the terrestrial planet with the largest diameter, mass and density in the solar system, about 100 million kilometers (1 astronomical unit) from the sun.

The Earth rotates from west to east while revolving around the Sun. At present, it is 100 million years old, and there is a natural satellite - the moon, and the two form a celestial system - the Earth-Moon system. It originated hundreds of millions of years ago from the primordial solar nebula.

The radius of the Earth's equator is kilometers, the polar radius is kilometers, the average radius is about 6371 kilometers, and the equatorial circumference is about 40075 kilometers. The Earth's surface area is 100 million square kilometers, of which 71% is oceans and 29% is land. The main components of the atmosphere are nitrogen and oxygen, as well as small amounts of carbon dioxide and argon.

The shape of the Earth is an irregular elliptical sphereWith the development of science and technology, people have a clear understanding of the shape of the earth: the earth is not a positive sphere, but an irregular sphere with slightly flattened poles and slightly bulging equators, with an average radius of 6,371 kilometers, a maximum circumference of about 40,000 kilometers, and a surface area of about 100 million square kilometers.

On the earth's surface, there are mountains, basins, rivers, lakes, and oceans, among others. It can be said that the surface of the earth is an extremely irregular curved surface, but these ups and downs are small relative to the whole earth.

The area of the earth is 100 million km2, the area of the ocean is about 100 million km2 of the earth's surface, and the land area is only about 100 million km2. The maximum undulation of the surface landform is 840m, and most of them account for 75% of the total area of less than 1000m.

The shape of the earth is also not static. It's always changing. Sometimes these changes are regular, such as the daily tides that affect the oceans and crust.

Other changes are irregular and very slow, such as the movement of the Earth's tectonic plates. Sometimes natural disasters cause sudden changes, such as **, volcanic eruptions, and meteor impacts.

The Earth is an irregular sphere with slightly flattened poles and a slightly bulging equator. The average radius of the Earth is 6,371 kilometers, the maximum circumference is about 40,000 kilometers, and the surface area.

About 100 million square kilometers.

The Earth's equatorial radius is longer than the polar radius, and the northern and southern hemispheres are asymmetrical: the North Pole is slightly convex, and the South Pole is slightly concave. In addition, the earth and its materials are always in motion, and the shape of the earth is constantly changing.

After long-term precise measurements, scientists have found that the earth is not a regular sphere, but an irregular elliptical sphere with slightly flattened equators at the poles. The Earth's equatorial radius is about long, which is so small compared to the average radius of the Earth that it can still be regarded as a regular sphere when viewed from the perspective of space.

The Earth is roughly ellipsoidal in shape. The rotation of the Earth.

The effect is slightly flattened along the Earth's axis that runs through the poles, and slightly uplifted near the equator. The Earth's equatorial radius is 43 kilometers (27 miles) larger than the polar radius. Therefore, the farthest point on the Earth's surface from the Earth's center of mass is not Mount Everest, the highest elevation.

Rather, it is located on the equator to tease Ecuadorian eggplant.

The peaks of Mount Chimborazo.

Due to the local undulations, the Earth deviates slightly from the ideal ellipsoid, but on a planetary scale, these undulations and the radius of the Earth.

Compared to the small amount, the maximum deviation is only.

The question of the shape of the earth is as follows:

The average radius of the earth is 6,371 kilometers, the maximum circumference is about 40,000 kilometers, and the surface area is about 100 million square kilometers.

Data Extension:

The shape of the earth, that is, the shape of the earth. With the development of science and technology, people have a clear understanding of the shape of the earth: the earth is not a positive sphere, but an irregular sphere with slightly flattened poles and slightly bulging equators, with an average radius of 6,371 kilometers, a maximum circumference of about 40,000 kilometers, and a surface area of about 100 million square kilometers.

However, it has been a long process to get this correct understanding.

In China, as early as the Zhou Dynasty more than 2,000 years ago, there was a kind of Gaitian theory that "the sky is round like a cover, and the place is like a chess game". With the development of production technology, the expansion of the scope of human activities, and the accumulation of various knowledge, people have finally discovered that there are some objective phenomena that cannot be explained by the intuitive and simple concepts of the early days.

Practice forced people to revise their original erroneous concepts, so some people put forward the idea of arching the earth, which gave rise to the "Hun Tian Theory".

Ancient Indians believed that the earth was carried by four elephants, standing on a giant turtle. The ancient Chinese believed that the sky was like a pot and was semicircular; The ground, on the other hand, is like a square chessboard, which is flat.

Zhang Heng, a famous scientist of the Han Dynasty, wrote in his "Notes on the Armillary Sphere": "The armillary sky is like a chicken, the celestial body is round like a projectile, the earth is like a chicken in the yellow, living alone, the sky is big and the earth is small." There is water in the sky, and the sky envelops the earth, and the shell is yellow. Heaven and earth stand by air, carrying water and floating. ”

According to the analysis of the lunar eclipse, the ancient Greek scholar Aristotle believed that the edge of the part of the moon that is obscured by the earth's shadow is arc-shaped, so the earth is a sphere or an approximate sphere. Magellan also made a voyage to prove that the Earth is a sphere.

Human beings have been exploring for a long time, and the first time Magellan ruler realized the circumnavigation of the world, confirming that the earth is a sphere. With the development of human science and technology and the application of modern detection technology, people finally discovered that the earth is an irregular sphere with slightly flattened poles and slightly bulging equators.

The shape of the Earth is almost as close to a spheroid as a spheroid, also known as an ellipsoid. However, due to the Earth's rotation and the uneven distribution of the Earth's crust and atmosphere throughout the Earth, the Earth is not exactly a perfect ellipsoid in detail. The Earth expands slightly at the equator, so the circumference of the equator is slightly longer than the circumference of the North and South Poles, giving the appearance of the Earth closer to that of a split stool ellipsoid.

Such a shape is very important to the Earth because it affects aspects such as the Earth's gravitational field, sea level, and climate.

The shape of the Earth can be approximately described as an ellipsoid. Specifically, the Earth takes on a slightly flattened shape, that is, it is slightly uplifted outward at the equator and slightly inwardly concave near the poles. This shape is known as the geosphere of the Earth.

In this geoellipsoidal model, the equatorial radius is about a kilometer longer than the polar radius.

However, it is important to note that the Earth is not an absolutely perfect state to take an ellipsoid. Due to factors such as the rotation of the earth, the density distribution inside the earth, and the movement of the earth's crustal plates, there are various topographic features on the earth's surface, such as mountains, plains, oceans, and continents, etc., so the shape of the earth is not completely uniform.

In addition, the sea level on Earth is not completely flat as it has ups and downs due to factors such as gravity and climate. To more accurately describe the shape of the Earth, scientists used the Earth's geid, which is an average surface established using sea level as a reference point.

Overall, the shape of the Earth is complex and varied, but can be approximated as a slightly flattened spheroid.

The shape of the Earth is an irregular sphere with slightly flattened poles and a slightly bulging equator. With the development of science and technology, people have a clear understanding of the shape of the earth. The average radius of the Earth is about 6,371 kilometers, and the maximum circumference is about 40,000 kilometers, or about 100 million square kilometers of surface area.

Specifically, the equatorial part of the Earth is bulging, a bit like a pear's "body", while the North Pole is a little pointed, like a "pear pedicle", and the South Pole is a little concave, like a "pear navel". Therefore, the earth is also figuratively likened to a "pear-shaped".

It should be noted that the shape of the earth is not completely regular, but an irregular spherical bridge. Due to the mass and gravitational distribution of the Earth, its shape may vary slightly from place to place. But these differences are so small that they are not noticeable to the early observations of human Pingsen.

The Earth is an irregular sphere with slightly flattened poles and a slightly bulging equator.

This conclusion was put forward by the British scientist Newton at the end of the 18th century after a series of careful calculations. He believes that because the earth is always rotating around its axis, the poles of the earth are slowly flattened in, and the equatorial part in the middle of the earth bulges out.

By the 20th century, developed scientific and technological means provided a variety of ways for earth surveying. Measurements show that the Earth's average equatorial radius is kilometers and the polar radius is kilometers, a difference of kilometers. Measurements also found that the Arctic region is about a metre higher than the Earth's reference ellipsoidal surface and the Antarctic region is 24.30 metres lower.

It is said that the shape of the earth is like a pear, that is, the equatorial part is bulging to be a "pear body", the North Pole is slightly pointed like a "pear pedicle", and the South Pole depression is like a "pear navel", so a "pear-shaped earth" is obtained.

Knowledge of measuring the shape of the Earth

We study the shape of the earth mainly in terms of the natural shape of the elastic earth's crust, as well as the surface shape of the land and ocean (bottom). Due to the complexity of the earth's natural surface, it is necessary to divide the earth's surface into a number of regions, carefully study the coordinates of the surface points within each area, and finally synthesize them.

In addition, the geophysical dynamics of the Earth's lithosphere, hydrosphere and atmosphere should be studied. The Sun, the Earth and the Moon should also be closely linked, and the Earth's gravitational field, magnetic field, thermal field and other physical fields, the Earth's rotation and revolution should also be studied. Due to the rotation of the earth, any point on the earth is affected by the earth's gravity and centrifugal force at the same time, and the combined force of the two is what we call gravity, and the direction line of gravity is called the plumb line, and the plumb line is also the reference line of the measurement work.

The above content reference: Encyclopedia - Earth Circle Swift Ball Shape.

Flat balls.

The earth is an irregular shape, it is slightly flattened, at first some people think it is round, oval, all kinds of speculation, but after some measurement data, with the midpoint of the earth as the center, the measured radius is about 40,000 kilometers, and its surface area is basically about 500 million square kilometers.

Newton's theories and laws were also opposed by other scientists, who believed that the earth was like an oval-shaped egg and a watermelon. Therefore, it is thought that French scientists sent two teams to actually measure the curvature of the earth, and through the actual measurement, they confirmed Mr. Newton's theory that the earth is an irregular oblate sphere, and thus it was recognized.

The movement of the earth

The Earth's gravitational pull interacts with other objects in space, especially the Moon, which is the Earth's only natural satellite. It takes about a few days for the Earth to revolve around the Sun.

The Earth's axis of rotation is tilted relative to its orbital plane, thus producing seasons on Earth. The gravitational interaction between the Earth and the Moon causes tides that stabilize the direction of the Earth on its axis and gradually slow down its rotation.