Why the earth is far away, why the earth is far away

To answer this question, we must first introduce the phenomenon of gravitational force. Physicist Isaac Newton discovered that all matter has a mutual attraction called gravitational or gravitational force. This attraction has a simple relationship with the mass and distance of the substance

The more substance and the greater the mass, the greater the attraction; And the closer the matter is to each other, the greater the gravitational pull. Even between two people, there is a gravitational pull; When people are in space where gravity is very small, the gravitational pull between people will bring their bodies closer. The gravitational pull of two big fat people is greater than that of two children at the same distance. Gravitational forces govern the movement of stars in the universe.

For example, the Moon revolves around the Earth, which is caused by the gravitational pull between the Moon and the Earth. Each planet contains a lot of matter, such as the Earth, and if you write its mass in kilograms, add twenty-four zeros after 6! In the universe, the Earth is just a relatively small planet.

The earth has so much material, and the gravitational pull is very large, which is why we will not fly out of space when we stand on the ground. Since all the material on the ground is attracted by the gravitational pull of the earth, it is difficult for the ground to get angled, and the mountains cannot be too high, because the gravitational pull of the earth wants to pull the material of the mountain peaks towards the center of the earth, so the earth is very round. The mass of the Moon is only one-eightieth that of the Earth, so the gravitational pull of the Moon is much smaller than that of the Earth, and the mountains on the Moon are much higher than those of the Earth (Figure 1).

According to the above theory, the more massive a planet is, the more round it is. Conversely, if the mass is small and the gravitational pull is small, the star may not be round. In fact, in addition to the nine planets, there are many asteroids with very small masses in the solar system, which are irregularly shaped, like a large rock (Figure 2).

However, even the largest planet, Jupiter (Figure 3), is not completely round. This is because Jupiter rotates very fast (one rotation every ten hours, the fastest of the nine planets), and the centrifugal force caused by its rotation is the largest, and the centrifugal force is greatest near the equator, so that the entire planet is flattened a little. In fact, all planets are the same, and we have to be very careful to observe.

This is determined by the peculiarities of the spherical shape.

Because the sphere is a central symmetry, every point on the surface is the same for the center—the same distance, the same force—this state should be the easiest shape to maintain relative to the others.

In addition, from the point of view of the formation of the earth, the earth was originally solidified by liquid, and by the action of gravity and tension, it was initially an approximate spherical shape. Moreover, even if the Earth was not circular at the beginning, it would have developed into a sphere during its continuous rotation for billions of years. The sharp places on the surface of the earth are more easily destroyed by external forces and gravity, which also makes the earth tend to be spherical.

Because of the law of gravitation, the earth absorbs the surrounding small stars and floating objects during the formation process, so that it expands, and because the earth rotates, it forms a sphere, so it is round.

Is the landlord a Martian?。。。 Think Earth is too far away from Mars?

The universe is very vast, because there are no spaceships, so human beings cannot go to the earth at present.

The earth is originally round, thank you for adopting.

The earth is round, and so are the other planets. The water droplets we see are also round in the air. The bubbles are also round.

Due to the surface tension of the liquid, the bubbles and small water droplets are round.

Why the earth is round begins with the birth of the earth. The original universe was a high-temperature, high-energy, high-density substance, and due to its large **, various planets were produced. At that moment, those planets were all hot and liquid, and also due to the action of surface tension, they were all round.

After hundreds of billions of years of cooling, the temperature on the surface of some planets gradually decreased, and then proteins were slowly produced, and life was born, and this planet is the Earth. In the various movements that followed, there was no reason to change it to other shapes, so it has always been in the circle until now.

But the Earth is not a standard sphere. The Earth is an irregular spheroid with slightly flattened poles. The radius of the Earth's equator (a) is 6378 140 km, the radius of the Earth's poles (b) is 6356 755 km, and the average radius of the Earth is (3 a2b) km.

From these data, we can see that the Earth's equatorial radius is large, why? That's because the earth is circling.

The centrifugal action of the middle part of the rotation is large, and the radius of the middle part, that is, near the equator, is larger.

In addition, the continuous changes in the earth's crust form the causes of mountains and oceans on the earth's surface, as well as **, volcanoes, etc., which will cause differences in the earth's surface.

Classmate, such a look, from outside the atmosphere.

Haha, because I like jokes. The shape of the Earth is mainly determined by its own gravitational pull, which in turn is centripetal. In the gravitational field, the plane is spherical, so the Earth is spherical.

Of course, the earth also has rotation (the axis of rotation is the north and south pole line), due to centrifugal force, the diameter of the earth at the equator is slightly larger than the diameter between the poles, a bit like an orange, not a perfect circle. Actually, it's not entirely certain that at the moment.

The circumference of the Earth's equator is 40,076 kilometers, and the circumference of the north and south poles is 39,900 kilometers.