Before human beings walked out of the earth, it is difficult for us to feel the earth turning. Although we can see the sun rising and falling, and the moon moving constantly, in the eyes of the ancients, whether it is the sun or the moon, They all revolve around the earth, and the earth itself is still. This is the geocentric theory that has ruled the human world for thousands of years.
After overthrowing the theory of the center of the earth, people gradually realized that the sun is the center and that the earth moves around the sun. Of course, people at this time have not realized that the earth itself is also rotating at a high speed. It was not until human beings entered the age of science and technology that we discovered the rotation of other planets through astronomical telescope observations, and then realized that the earth is also rotating.
The reason why human beings cannot feel the rotation of the earth is actually due to the influence of gravity. The gravity of the earth firmly binds us so that everything on the surface can move in sync with the earth, so that we are still relative to the earth. Yes, it is natural not to feel that the earth is rotating at a high speed.
It was not until human beings stepped out of the earth with the help of science and technology that we could truly see the high-speed rotation of the earth from space. The rotation speed of the earth is very fast. If it is on the equator, it reaches 465 meters per second, and the rotation we can understand is 24 hours a day. This time is actually brought about by the rotation of the earth.
So is the rotation speed of the earth stellar? Of course not. According to the research of scientists, the speed of the earth’s rotation is not uniform. From the long-term trend, there are three characteristics: 1. Long-term slowing down; 2. Periodic change; 3. Periodicity Changes are irregular.
Since the birth of the earth 4.6 billion years ago, its rotation speed has been slowing down. In just the past 2000 years, the time has slowed down by more than 2 hours. However, 370 million years ago, the earth revolved 400 times around the sun, which means that there are 400 days in a year, while the current year is 365 days.
In addition, the rotation speed of the earth is not a complete stellar state within a year, and it will also accelerate or slow down at certain times. For example, the probability of slowing down in spring is high, but in autumn it is It may become faster. Scientists believe that the reason for this situation may be related to the monsoon on the earth.
You must know that the air is also of quality, and this quality is not small. According to research calculations, the air quality involved in the monsoon reaches 300 trillion tons every year. When such a large mass flows in the ocean and land, it will inevitably have a certain impact on the rotation speed of the earth. In addition to these, the movement of the plate will also affect the rotation speed of the earth, making it show periodic irregular changes.
So how did the force required for the earth’s initial rotation come from? How did the rotation of the earth come about? To understand the origin of the earth’s rotation, we need to travel back to 5 billion years ago, when the solar system was not yet born.
In 5 billion years ago, the position of the solar system was still a nebula, which we call the solar nebula. According to scientists’ research, stars and stellar systems basically originated in a nebula, but different nebulae have their origins. It’s different.
The predecessor of the solar system, the Sun Nebula, is not an ordinary nebula. We all know that the earth, including the entire solar system, is rich in various heavy metal resources. However, heavy metal resources are also very scarce in the universe. In the early days of the universe, there were only hydrogen, helium and a small amount of lithium, and the origin of various heavy elements was related to stars.
Nuclear fusion within a star can produce a certain amount of heavy elements, but the types of heavy elements that can be transformed by nuclear fusion are very limited, up to 26 element iron at most. The subsequent heavy elements can only be produced by the supernova explosion of massive stars and the collision and melting of neutron stars.
It can be seen that the solar system can have such a wealth of heavy metal resources, indicating that before the birth of the solar system, there used to be massive stars in this location. After the massive stars reached the end, after the supernova explosion occurred, a large amount of heavy metal elements were produced and merged. In the solar nebula.
At the same time, the huge force generated by the supernova explosion also promoted the rotation of the solar nebula, allowing it to spin up quickly, causing the matter in the nebula to aggravate the collision and fusion, so the central sun and the major planets were born.
In the process of planet formation, multiple planetesimals will continue to collide and merge, so that the original planet will have a relatively large angular momentum, so that the planet can rotate rapidly, of course, the conservation of angular momentum cannot fully explain the origin of the celestial body’s rotation. , Because according to the law of conservation of angular momentum, the greater the mass of the celestial body, the faster its rotation speed should be.
But in reality, what we see is not the case. The mass of the sun accounts for more than 99% of the total mass of the solar system, but its rotation speed is slow. Although the rotation speed of the eight major planets is fast, it cannot keep up with some. Compared with the rotation speed of the asteroid. Some asteroids rotate very fast,
Therefore, scientists believe that the formation of the rotation of celestial bodies cannot be explained by a simple conservation of angular momentum. It has other factors. As for the formation process of the earth’s rotation, scientists already have a lot of understanding.
Conservation of angular momentum and the sun’s gravitational force accounted for the main factors affecting the rotation of the earth. The reason why the rotation speed of the earth was very fast at first was affected by these two factors. But later, the appearance of a celestial body changed the rotation of the earth and also changed the destiny of the earth. It is the moon around us.
As for the origin of the moon, the current mainstream view is the impact hypothesis, that is, in the early days of the formation of the earth, another Mars-sized body in the same orbit hit the earth, and the debris from the impact formed the current moon.
The appearance of the moon has a great influence on the rotation of the earth. Because the mass of the moon itself is very large, its gravitational force is exerted on the earth, which makes the rotation speed of the earth continue to slow down. It is precisely because of the continuous slowing down of the earth’s rotation speed that the subsequent ecological system was formed and life was born.
The earth’s rotation speed has been slowing down all the time. In fact, the main factor is also related to the moon. Without the moon, the earth’s rotation speed will continue to slow down, but the slower speed will be much slower than it is now. The earth is very unfavorable for the birth and evolution of life. Therefore, the fact that the earth can become a planet of life is sometimes a part of luck.
Of course, the laws of the movement of celestial bodies are only the fur that human beings have, and we still have unsolved mysteries about gravity. What’s more, there are mysterious dark matter and dark energy in the universe, which human beings still don’t understand at all. They are hidden behind the universe and may be the origin of all the laws of the universe. To unravel this mystery, we need the assistance of scientific power. As long as human technology can continue to develop rapidly, I believe that one day, there will be no secrets in the universe.