Sunrise and sunset are a very common natural phenomenon for people on earth. As long as the earth does not stop rotating, this phenomenon will continue.
However, have you ever thought that All things need power to run. What is the power that supports the earth's rotation for 4.6 billion years? If one day this power is "used out", will the earth stop? What is it like to live on a stalled earth?
How was the rotation of the earth discovered?
In fact, people know that the earth will rotate, which is just a matter of recent hundreds of years.
As we all know, before the Middle Ages, it was generally believed that the earth was the center of the universe, and all other celestial bodies revolved around the earth in circular orbits. After all, the sun rises from the east and sets from the west are all commonplaces.
But a "madman" came out at this time. Copernicus tells everyone that this is not the case. It is not the sun revolves around the earth, but the earth revolves around the sun. The reason for day and night is because our earth is rotating around the axis.
This is obviously inconsistent with the physics of Aristotle advocated by the church at that time. Of course no one believed his point of view. Many people jumped out to refute Copernicus’s statement: You said that the earth will rotate, so why don’t the people above fall? If the earth is moving, then when the object falls down, it should not fall at the foot, but at the back, because when the object is falling in the air, the earth moves forward.
They believe that even if the earth is not the center of the universe, "the matter on the earth naturally falls to the center of the universe" should still be true, so if the earth is moving, the object should fall backward rather than vertically. It is said that the earth will rotate, so come out with your evidence.
Although it was later proved that Copernicus's idea was not only completely correct, but also opened a new era of astronomy, it was restricted by technical conditions at that time, and no one could prove through scientific experiments or observations that the earth was indeed rotating.
1679, after reading the universal gravitational research report of Newton , the famous scientist Levin Hook suddenly had a whim: if the earth is really rotating, then the path of a freely moving object, relative to a fixed reference coordinate system, will cause the visual path offset due to inertia.
For example, the ballistics of falling objects in the northern hemisphere will deflect to the right from the direction in which they are shot. So he threw a ball of iron at a height of 8.2 meters, predicting that it might deviate from the east by half a millimeter. However, the experiment was not successful due to insufficient whereabouts. It was not until nearly 300 years later that astronomers from Bologna and hamburger gathered together and re-exerted this experiment on the tower, which proved that Hook's idea was completely correct.
Another famous experiment came from the French physicist Fuke , who worked as a professor of physics at the Paris Observatory. In 1851, he hung an iron ball with a length of 67 m from the top of the tower at the Pantheon in Paris, France.
He imagined that if the earth is really rotating, it will cause the swinging plane to oscillate, thereby causing the offset, and the speed of rotation depends on the latitude. At the latitude of Paris, the predicted and observed offset is about 11 degrees clockwise per hour. This fully proves that Copernicus proposed the hypothesis of the earth's rotation back then, which was completely correct.
So the question is, since the earth has been rotating, why can't we feel it? Instead, do you feel that the sun is spinning around us? This is because we humans are too small compared to the earth. Just like we have to look at a very distant sea line to see the phenomenon of sails appearing before the hull, we also have to go a long distance to discover the impact of the rotation of the earth on the tiny human beings living on the surface of the earth.
What is the power of the earth's rotation?
The earth has been rotating for the past 4.6 billion years, so what force has been maintaining the earth's rotation?
In fact, in the universe, all celestial bodies are rotating, because in terms of physics, all celestial bodies have angular momentum .
The formation of the earth is only part of the birth of the solar system: initially there were only a large amount of rotating dust, rocks and gases in the solar system. The chemical element that made it was composed of hydrogen and helium produced by the Big Bang, and the heavy elements released by the supernova . This interstellar dust is uneven, and any asymmetry in the gravity accretion process leads to the angular momentum that eventually forms the planet.
The rotation of the earth is also because the original solar system nebula that forms the earth rotates and compresses. When the earth is formed, it naturally "shares" some of its angular momentum.
However, why does the earth's rotation axis direction have an inclination angle of 23.5 degrees with the solar system disk? Why does the earth rotate every 24 hours a week?
Currently, astronomers have different opinions on these two issues, but it is more common to believe that this is related to the impact of tidal force .
The rotation speed of the earth is not static. The tidal force of the sun and the moon on the ocean slows the earth's rotation speed. It is said that the Earth's 1.6 milliseconds will increase every 100 years. This also leads to a gradual decrease in the number of days on Earth in a year. There is scientific evidence that the middle period of the Devonian , and the year at that time is equivalent to the current 400 days.
Since the tidal force can make the earth rotate slowly, will there be a day when the earth really stops rotating? What will happen then?
Many people may think that we will be thrown to the east at a speed of 460 meters per second, because according to the law of inertia, a car driving at a high speed suddenly brakes, and people will definitely fall in the direction of the car driving.
But remember that it is a sudden brake. If it is really due to the effect of tidal forces, it is actually a process of gradual slowdown. Just like now, do you realize that our day has been longer than hundreds of years ago? Obviously not! Therefore, the situation where people are thrown out in an instant will naturally not occur due to tidal forces.
However, this does not mean that the slow slowdown and stopping of the earth will not bring disastrous consequences. The most obvious thing is that the earth is no longer divided into night and daytime. Half of the earth is in the light of day for a long time, and the other half is trapped in endless darkness.
The temperature of the eastern and western hemispheres will be very different. This will lead to a large number of biological extinctions. Even if a species eventually survives, it will probably be completely different from the species I see now.
Another influence is atmospheric movement. The atmosphere will continue to move forward under the action of inertia, causing the atmosphere and the ground that originally did relative movement together to become the atmosphere and do absolute movement, which eventually leads to all objects on the ground suffering from a strong hurricane.
There are many scientists who believe that although the earth stops rotation, it does not mean that there is a lack of rotation momentum or so-called angular momentum at the equator, because this angular momentum is transmitted to air, water and even rock along the equator, will continue to move at a speed of 1770 km/h. This movement causes the earth's surface to tear into pieces, which fly to the upper layer of the atmosphere and then spread to the outer space.
At the same time, the earth's crust will also shift, and earthquakes, volcanic eruptions, and other disasters are inevitable, and the atmosphere will also cause strong storms. It can be said that human beings will face unprecedentedly serious disasters.
Of course, this is just an interesting implementation of ideas by astronomers. After all, when the earth stops autobiography, humans may have moved to other planets long ago. Of course, I won’t worry about the disaster that will come.
