Why is the earth round, but now we are walking flat

This is due to the peculiarity of the circle, because the sphere is a central symmetry, and every point on the surface is the same for the center -- the same distance, the same force, and this state is supposed to 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 As for why it is elliptical, it is because the earth is rotating. The earth revolves around the earth's axis, and the equator is the fastest place to rotate, so the centrifugal force is large, and the earth's crust is "flung outward" and protrudes outward, becoming an ellipsoid. To put it mildly, if you have time to knead the dough, insert a stick in it to make a shaft, and then quickly turn the shaft, you can also see the dough slowly flattening.

This is the same as the flattening of the earth. Because of gravity, we can walk on the ground, such as Newton's discovery that the apple fell to the ground. And the earth is very big, you naturally feel that you are walking on flat ground, so have you ever seen the sunset?

At sunset by the sea, when the sun sets, the horizon at sea level is arcing, precisely because the earth is round, and all the galaxies of the universe are not round? Forehead. Let's take a look at Newton's theory of gravity.

Why is the earth round, but the ground flat?

The earth is round, but people feel flat on the ground because human beings are very small compared to the earth. This arc can be considered invisible because everything seen is flat.

In this case, the ground as seen by one is flat, even though the entire earth is round. If you look at the Earth from space, you can clearly see that the Earth is round and is a sphere.

The earth is so big that it can be seen flat everywhere people can see it, and if you want to see the arc, it is a very difficult thing to do. But when you put people on a certain point on the surface of the earth, the place where you can see is nothing to the curvature of the earth, and the earth as you see it from that point is flat.

The Earth is oval.

Earth is the third planet to be from the Sun and the only known object that harbors and supports life. 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.

Relatively small. Most of the Earth's polar regions are covered in ice.

Pivot inclination

The existence of the orbital inclination causes the Earth to revolve around the Sun.

when the sun shines directly on the point.

In the Tropic of Cancer and the Tropic of Cancer.

This is a return year with a mean solar day (i.e., 365 days, 5 hours, 48 minutes and 46 seconds).

The length of day and night and the angle of solar altitude in different latitudes on Earth.

This in turn causes the total amount of solar radiation received by these areas to change in a day, resulting in seasonal variations. When the North Pole is closer to the Sun relative to the South Pole, the direct point of the Sun is located in the Northern Hemisphere.

At this time, the days are long and the nights are short in the northern hemisphere, and the solar altitude angle is larger, which is half a year of summer; The southern hemisphere has short days and long nights, and the solar altitude angle is small, which is half a year in winter; Vice versa.

In the north temperate zone north of the Tropic of Capricorn, the sun always rises in the southeast direction and sets in the southwest direction; In the southern temperate zone, the sun rises in the northeast and sets in the northwest.

The earth is like a circle, not flat. 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, exaggeratedly speaking, a bit like a "pear", called a "pear-shaped body".

Peculiarities of the Earth.

The Earth is an irregular elliptical sphere with slightly flattened poles and slightly bulging equators. The Earth is one of the eight planets of the solar system.

It is the third planet in descending order from closest to the sun, and it is also the terrestrial planet with the largest diameter, mass and density in the solar system.

The air temperature on the Earth's surface is exposed to solar radiation.

The global average surface temperature is about 15. In the depths of the subterranean area, where sunlight is not visible, the temperature is mainly affected by geothermal heat, which increases with depth. The Earth's core at the center of the Earth.

The temperature is more than 6000 meters, which is higher than the surface temperature of the solar photosphere.