Why the Earth is not square 5, why is the Earth not square

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 the substance, 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.

Lou pig brain (n words omitted here).

The reasons why the earth is not square: 1. Under the influence of various gravitational forces, it rotates and rotates, and the centrifugal force of rotation shapes the earth into a circle; 2. Affected by the tension of the object; 3. In space, where gravity is extremely small, liquid matter will automatically form a spherical shape.

The Earth is our living planet, and as we all know, the Earth is round, not square, and this is what we have been told since childhood. So why is the earth round? Many people don't know why, let's find out together.

01 The movement of objects in the universe is always affected by various gravitational forces, so they both revolve and rotate, and the centrifugal force of rotation shapes them into a spherical shape.

02 It is related to the tension of the object, just like a drop of water will appear spherical in a vacuum.

03 In space, where gravity is minimal, liquid matter will automatically form a spherical shape.

04 The Earth was born long ago when rocks in the solar system collided with each other to form planets. From the beginning of its formation until the present, the earth has been mainly composed of liquid rocks.

05 In space, where gravity is minimal, liquid matter will automatically form a spherical shape. This has been demonstrated by experiments conducted by astronauts in the space environment with substances such as water, fruit juice and liquid metal. The Earth is a huge liquid sphere at a considerable distance from the Sun, which gradually forms a circle as it moves through space.

The fact that the earth is square is only people's conjecture, because the range of activities is small and the technology is backward, so it can only be observed by sight and according to the naked eye.

With the production technology.

Through observation, people realize that the earth is arc-shaped.

Around 500 BC, Pythagoras.

The idea that the earth is spherical was proposed.

100 years later, Aristotle.

Arguments were made. (Lunar eclipse.)

when the Earth is projected on the Moon).

Zhang Heng, an astronomer of the Eastern Han Dynasty in China.

There was once a saying that "the sky is like a chicken, and the earth is like a yellow chicken".

1519-1521 Magellan.

The success of the Globe Week provides strong evidence for the idea that the Earth is spherical. The development of the nautical industry and the compass.

The invention guaranteed the success of circumnavigating the globe. (The computer screen shows the "Magellan route map", and as the route on the map slowly extends, the teacher briefly explains it, such as the place of departure, the ocean crossed, the strait, and back to the place of departure).

Time. Representatives.

Awareness of the shape of the earth.

Explain the method. Ancient times.

Not. The sky is round.

For example, an analogy. Afterward. Not.

The bend is in an arc.

Give an example. Around 500 BC.

Pythagoras.

Imagine that the earth is spherical.

More than 100 years later.

Aristotle.

Demonstrate that the earth is spherical.

Give an example. China's Eastern Han Dynasty.

Zhang heng. The ground is like a chicken in yellow.

Draw an analogy, make a comparison.

15th-16th centuries.

Magellan. Confirm that the earth is spherical.

Circumnavigating the globe. XVII century.

Newton. Assertion of the Earth's oblate sphere (inference).

Comparisons. Cassini.

Think of the Earth as a long sphere.

The 30s of the XVIII century (French scientists) measured an oblate sphere.

Right now. After the precise calculation of modern science, it is concluded that the earth is elliptical.

The equatorial radius is 6378140 meters, the polar radius is 6356755 meters, and the flattening rate is 1

According to normal development: male-female ratio.

It should be kept at 1:1

However, the development of some technologies has made it possible for people to control the sex of their children (such as fetal sex determination), which artificially interferes with the sex determination process and has a great impact on the ratio of male to female offspring.

I'm not a world culturer, but at least I'm familiar with Chinese culture, and I strongly believe that the global ratio is 106:100.

The extra 6 are all Chinese men.

Square EarthIf the earth is square, travel agencies can launch tours of the "Earth Octagon Tour". These eight corners may be high mountains. Can you imagine?

Okay, let's imagine that the earth is an octagonal box, and you're as small as an ant, walking around the box. The direction of "down" is always the ** of the box. If you stand in the middle of one side of the box, look up and see that the ground is flat.

Now let's say you start walking to the corner of the box with your tiny ant feet, and the closer you get to the corner, the more you feel like you're climbing a mountain, and the terrain is getting steeper and steeper. When you get to the corner, you're already on the top of the mountain.

What if our Earth were a cube? It is said that there will be 4 separate ecosystems! One Earth, Four Worlds.

Heh explained.

1. Surface tensionA drop of liquid suspended in space is spherical! This is due to the action of surface tension.

The Earth is almost liquid except for the solid surface of the Earth, which is a solid surface, and the Sun is even more fluid. Due to the same principle, it is spherical.

Interpretation. 2. Gravitational force. If not affected by external forces, all objects have a tendency to concentrate towards the center under the action of gravitational force. The most concentrated knots.

It's spherical! Although the surface of the earth is solid, because solids are also deformable, and solid fragments can move, these.

all make it possible to transform it into a spherical shape.

The activity of energy in the Earth's interior makes the Earth irregularly shaped. However, the stones of the mountains are rolled down from a high place by the gravitational pull of the earth (gravitational pull), and the rivers carry the sediment from the high to the low-lying oceans (the rivers also flow by the gravitational pull of the earth)...These are all examples of concentration towards the center, and they all make the earth.

The ball changes from irregular to spherical. If the Earth's interior ceases to move, it is possible that in many billions of years the Earth will become a very standard spherical shape (with the exception of centrifugal force and the gravitational pull of other celestial bodies).

Many asteroids, due to their own small mass, resulting in their own gravitational force is relatively small, and the star is generally composed of relatively hard solid rock, it is difficult to complete the process of moving to the center under the action of its own gravity, so their shape is strange, oval, rod-shaped.

With the continuous advancement of measurement technology, especially the use of artificial earth satellites, the Earth is now measured.

The equatorial radius is 6378140 meters, the polar radius is 6356755 meters, and the difference between the two is 21385 meters.

1/。In this respect, the earth is much rounder than oranges.

In addition, it has been found from the measurement that the equator of the earth is not a perfect circle, but an ellipse, the maximum.

The radius differs from the minimum radius by more than 200 meters. It was also found that the northern hemisphere of the earth is more slender than the southern hemisphere; North pole.

The area of geoid (i.e. mean sea level) is about 10 meters higher than the reference oblate sphere, the Antarctic region.

It should be recessed for about 30 meters. Therefore, some people compare the shape of the earth to a pear, and the earth body is said to be pear-shaped.

Body. In fact, the earth is neither like an orange nor a pear, but a sphere with its own unique shape.

If we shrunk this huge Earth into a globe with a diameter of 1 meter, the radius of the equator is only greater than the poles.

The radius is more than 1 mm long, and this slight difference cannot be represented on the globe, so we use it.

The globes are still perfectly round.

I know it's not round.