The pursuit of perpetual motion machine by human beings can be said to be an end that can never be reached in the history of science.
But have you ever wondered if we are in the operation of a "perpetual motion machine"?The Earth has been revolving around the Sun for 4.6 billion years and will continue to rotate until it is destroyed. What is the "power" that supports its rotation?
The cause of the Earth's rotation even needs to be traced back to the formation of the sun.
4.6 billion years ago, before the Sun was formed, the solar system was left with just a huge primordial nebula composed of a large amount of gas (mainly hydrogen and a small amount of other elements) and dust, floating aimlessly in the universe. Suddenly, one day, a supernova explosion occurred near this huge primordial nebula. Under the influence of the tremendous energy of the supernova explosion, the density of matter in a certain area of the interior of the primordial nebula increased.
The gravitational pull of the area of increased density must also be larger, and the gravitational pull of the gas and dust in the cloud gradually approaches and collects in this area. This leads to a further increase in the compression and density of the clouds.
In the center of the rotating disk of the primordial nebula, the core region begins to become hot and dense enough due to the increase in pressure and temperature. Under certain conditions, when the temperature of the gas core reaches about 15 million degrees Celsius, hydrogen begins to undergo nuclear fusion reactions. This nuclear fusion process releases a huge amount of energy that forms the sun. The core of the Sun continues to undergo fusion reactions and continuously releases light and heat.
After the sun is formed, because of the huge gravitational pull, it attracts the remaining material around it to revolve around it. Under the action of gravity, these materials gradually accumulate and contract, gradually forming stars in the solar system, including the earth. Due to the conservation of angular momentum, these rotating materials remain rotating after the formation of the Earth, which forms the rotation of the Earth.
This is currently the most widely disseminated hypothesis of the cause of the Earth's rotation. However, there are some problems with this hypothesis, for example, according to the theory of this hypothesis, the more massive the planet should rotate faster, and all the stars in the solar system should revolve and rotate in one direction.
But this is not the case, the mass of the Sun is much greater than that of the Earth, but its rotation speed is not as fast as that of the Earth. Moreover, most of the stars in the solar system do rotate in a counterclockwise direction, but a few planets such as Venus and Uranus rotate in a clockwise direction.
It is precisely because of these logical loopholes that hypotheses about the cause of the Earth's rotation have been put forward in recent years. However, none of these hypotheses are perfect, and they are more or less problematic, so they are not widely accepted.
Of course, the earth is by no means a perpetual motion machine, and although its rotation life is very long, it is not that it will not stop.
The force is what changes the state of motion of an object, and the state of motion of an object does not change without force. So, unless there is a force strong enough to shake the Earth's kinetic energy and angular momentum, the Earth's rotation will continue.
However, even now there is no force that can completely end the rotation of the Earth. However, there are always some forces that will have some effect on the rotation speed of the earth.
Chief among them is the gravitational force of the solar nucleus and the moon on the Earth. The gravitational force causes the earth's oceans and land to form periodic ebb and flow, which is commonly referred to as the ebb and flow of sea water. Because the ebb and flow of the tide creates friction, it consumes the kinetic energy of the earth, causing the earth's rotation to gradually slow down.
At the same time, the Moon will gradually move away from the Earth due to the gravitational force, causing the Moon's cycle to revolve around the Earth longer. It is estimated that the Earth's rotation slows down by about 17 milliseconds, the distance between the Moon and the Earth increases by about 38 cm.
In addition to the gravitational force, the Earth's rotation is also affected by other factors, such as atmospheric friction, continental drift, crustal activity, and nuclear testing. Because these factors may change the mass distribution, shape, and moment of inertia of the Earth, which in turn affects the speed and direction of the Earth's rotation. For example, in 2004, the Indian Ocean tsunami caused the Earth's rotation to speed up by about 3 microseconds, and the Earth's axis tilted by about 25 cm.
However, in fact, such effects are slow and negligible, and scientists speculate that it will be at least tens of billions of years before life on Earth can clearly feel the impact of changes in the Earth's rotation speed on the environment.
Exploring the rotation of the Earth is important for us to understand the mechanism and dynamics of the Earth. With enough knowledge of the Earth's rotation, we can understand natural phenomena such as climate change, weather patterns, and more.
At the same time, through the study of the Earth's rotation, it is essential to gain a deeper understanding of the Earth's internal structure, geophysical phenomena and interactions with other celestial bodies, which is essential to promote the development of earth science and raise the awareness of Earth conservation.