The statements in this article are based on reliable sources and are repeated at the end of this article
Text/Guanwen Shi said
Editor/Guanwen Shi said
Have you ever wondered why time always flies so quickly, a day passes in the blink of an eye? And now, there seems to be a scientific explanation for this question. [Floating clouds]
Scientists have found that since 2020, the Earth's rotation has accelerated!
We often say, "24 hours a day", but in reality, over the past few decades, our "day" has been quietly changing – getting shorter and shorter!
So why is that, how has the Earth's rotation changed, and how does it affect our modern society?
01
The rotation of the Earth
Since ancient times, the rotation of the earth has been the cornerstone of human understanding of the world, and its mystery lies in maintaining the dynamic balance of its own state of motion.
The rotation of the Earth is the rotational motion of the Earth around its own axis, and this axis is known as the Earth's axis.
The Earth's axis is not a physical existence, but a theoretical imagination, and the rotation of the Earth has led to the change of day and night as we know it.
In fact, due to the rotation of the Earth, the time of daylight is not the same in different regions, and in some areas it may be dark at six o'clock, while in others it may be necessary to wait until eight o'clock to get dark.
Conventionally, we divide the day by sunrise and sunset, but with the advancement of technology, we find that the day is actually made up of 23 hours, 56 minutes and 4 seconds, instead of the 24 hours we are Xi to.
But then scientists discovered that the Earth's rotation is accelerating, causing our daily hours to seem shorter.
For the past few decades, the Earth's rotation period has been slightly longer than the standard 24 hours, but in 2020, the situation changed, and the Earth's rotation speed suddenly accelerated, reducing the rotation period by about 1 millisecond.
To adjust for the difference between Coordinated Universal Time (UTC) and the Earth's rotation, scientists introduce a measure called "leap seconds".
A leap second is an addition of one second to the last minute of a particular day, making the day 61 seconds, and we have added 27 leap seconds since 1972.
On June 29, 2022, the shortest day for the Earth's rotation was a full 1.59 milliseconds shorter than the 24-hour period, which was the shortest day on record for the Earth's rotation.
02
What does it mean for the Earth to rotate faster?
Have you ever thought that you wake up every day to find that you have one minute missing? It's not because your phone is malfunctioning, it's not because you woke up too late, in fact, it's because our home, the earth, has been rotating at a certain speed for the past few decades.
According to the British "Daily Mail", as early as the early 90s of the 20th century, scientists have discovered the phenomenon of accelerating the earth's rotation, and speculate that it may be caused by a series of factors, including natural disasters such as earthquakes, volcanic eruptions and climate change, as well as global warming caused by human activities.
According to research, the Earth's rotation is gradually accelerating, shortening by about 1.4602 milliseconds per year.
This small change may not seem to have a noticeable impact on human daily life, but the Earth's ancient gravitational system and natural environment can change slightly, which can have an impact on infrastructure such as communications, electricity, and navigation around the world.
The acceleration of the Earth's rotation will lead to subtle changes in the magnetic field, which will directly affect the work of communication and navigation systems.
Changes in the magnetic field can cause signal interference, communication interruptions, and navigation errors, and devices that synchronize with NTP servers, such as computing devices and smartphones, also face time jumps, which in turn affect network communication and system operation.
Faster rotation will change the trajectory of ocean currents and atmospheric circulation, and may trigger abnormal weather events, such as typhoons, tsunamis, floods and droughts.
This not only poses a threat to human society, but also adversely affects the stability of ecosystems, which may lead to the survival of species and even extinction.
On the other hand, the acceleration of the Earth's rotation speed will also cause some changes to the Earth itself, and the shape of the Earth will shift, with the Northern Hemisphere shifting to the right and the Southern Hemisphere to the left, thus forming an irregular shape.
If the rotation speed exceeds the limits of the Earth's gravity, the Earth will not be able to hold all life and matter firmly, thus losing the holding power of matter on the surface, and everything will be thrown back into space.
This process also creates noticeable changes around people. As the rotation speed increases, people will feel a reduction in the weight of their bodies and it will become easier to carry heavy objects.
The day will also get shorter and shorter, and even the speed of water will slow down, and people will feel that the time passes faster.
Of course, the premise of the above result is that the rotation speed of the earth changes greatly, but now it seems that the rotation speed of the earth changes very little, so the impact is very small.
So why is the Earth's rotation accelerating?
03
The reason why the Earth is transforming itself fast
Since the birth of the Earth, its rotation speed has been slowly changing.
In the modern world, our daily lives do not seem to be affected, but the Earth's rotation rate does continue to accelerate.
What is causing this to happen?
Rising temperatures cause glaciers to melt, sea levels rise, and intensify internal movements in the Earth's crust, which affects the Earth's rotation speed, which is enough to see the impact of human activities on the Earth's rotation speed by 1.8 microseconds after a major earthquake in Japan.
Studies have shown that one of the main reasons why global warming affects the speed of the Earth's rotation is the melting of glaciers.
The rise in temperature causes glaciers to melt, causing a large amount of water to flow into the oceans, which changes the mass distribution of the oceans and affects the angular momentum of the Earth's rotation.
Rising sea levels also cause changes in the speed of the Earth's rotation. Rising sea levels adjust the Earth's mass distribution, which creates a torque on the Earth's rotation.
Another important factor is that the distance of the Moon is gradually increasing, and although this process is very slow, it has a significant impact on the entire Earth system.
The Moon has long been one of the important sources of gravity on Earth, and its presence not only controls the tidal laws on Earth, but also helps balance the Earth's rotational motion.
Due to a variety of complex factors, such as centrifugal forces generated during the formation of the Moon itself, the Moon is gradually detaching itself from the Earth and drifting towards space outside the solar system, which will cause the Earth to lose some of its gravitational restraint from the Moon, and its rotation speed will continue to increase.
So, which of these two factors is better to explain the current phenomenon of the Earth's rotational acceleration?
In fact, the relationship between the two is not monolithic or linear, but rather intertwined with each other, shaping what we see now.
With further research, scientists may be able to shed more light on the relationships and provide us with more scientific evidence, whether it's for current problems or for the future, which will be a significant endeavor.
04
Will humanity be thrown out of the earth as the Earth's rotation accelerates?
When it comes to the issue of the acceleration of the Earth's rotation, many people may worry about whether humans will be thrown out of the Earth's confines as a result.
First of all, let's be clear, although it is true that the Earth is constantly rotating, the speed of this process is very slow.
In fact, it takes about 24 hours for the Earth to rotate around in one cycle, and this speed is almost always the same, so even if the Earth's rotation accelerates, this small change has no effect on daily life.
We can safely say that the current acceleration of the Earth's rotation is not enough to have a direct impact on human beings, who will still stand firmly on the surface of the Earth.
At the Earth's equator, the Earth's rotation creates a huge centrifugal force, and although the average angular velocity makes the Earth's surface move so quickly, it does not mean that people will be thrown off the Earth as a result.
This is because our mass is not large enough to generate enough centrifugal force to counteract the gravitational pull of the Earth and take us out of orbit of the Earth, and in order to really leave the Earth, we need a huge thrust to overcome the action of the Earth's gravitational pull.
In fact, in order to counteract the limitations of the Earth's gravity, the rocket must be launched with a large amount of thrust to ensure that its speed and qualification exceed the Earth's gravity in order to successfully exit the Earth's surface.
When considering the acceleration of the Earth's rotational speed, it is important to note that the speed of the Earth is relative to the Sun, and an increase in the Earth's rotational speed will have a range of possible effects on the Earth.
If the Earth's orbit increases, the angle and time of day of the sun's illumination will change, which in turn will affect the seasons and weather patterns.
As the Earth gets closer to the Sun, the atmosphere may be exposed to stronger solar radiation, causing changes in the properties of the atmosphere, further altering its stability.
The acceleration of the Earth's rotation does not throw us into space, and the increase or decrease in the Earth's rotation speed will affect our lives in some ways.
In future research, we will be able to learn more about these phenomena and use this information to improve our lives and social environment.
05
How did 24 hours a day come about?
Did you know that the most common way to keep time in your life, "24 hours in a day", does not come directly from the time it takes for the Earth to rotate around its axis, but from a unit of time called a sidereal day.
Let's first understand how the earth rotates and revolutions.
When the Earth rotates along its axis, the phenomenon of day and night is formed, which is called rotation, while the rotation of the Earth around the Sun is known as revolution, and since this process takes much longer than rotation, people usually define a whole day as a complete rotation cycle.
However, the reality is not so simple, the rotation speed of the Earth is not uniform, which means that at some point it takes longer for the Earth to complete a rotation.
To ensure the accuracy of time, the International Organization for Standards has developed a global time system called Coordinated Universal Time, which is based on precise measurements by atomic clocks and takes into account factors such as changes in the Earth's rotation.
In this system, the "astronomical second" is the most basic unit of time, equivalent to the time it takes for the Earth to rotate around its own axis at an angle of about four trillions of trillions.
This tiny unit of time is very important for scientific research and technical applications, but it is clearly too precise for most activities of daily life.
In order to make time more suitable for daily use, scientists have further divided astronomical seconds into larger units of time, such as seconds, minutes, hours, etc.
The "hour" is defined as the time it takes for the Earth to rotate about 1/24 of a week along its axis, i.e. about 15 degrees of angular variation, and in this way, a day is divided into 24 hours.
It's important to note that although we now generally use a 24-hour clock, there is actually a slight difference in the actual length of the day. Since the Earth's rotation speed is not constant, it is affected by a variety of factors, including changes in the Earth's internal structure, ocean tides, and more. These factors cause subtle changes in the Earth's rotation speed, resulting in a difference in the rotation time from day to day.
In order to avoid the inconvenience caused by this situation, the researchers proposed a correction method to adjust the standard of earth time by adding or subtracting seconds, so as to ensure the synchronization and accuracy of time around the world.
This method is known as "leap seconds" and may occur several times a year.
06
How long is a second?
Historically, the length of the day was first defined by observing the rise and setting of the sun to determine the law of day and night.
Due to the instability of the Earth's rotation speed, the "day" obtained by this method is not a completely uniform unit of measurement.
Later, with the development of science and technology, people invented quartz clocks, whose oscillation frequency is relatively fixed, which greatly improves the accuracy of time, but this still cannot meet the needs of scientific research.
Have you ever wondered how long a second is? If your answer is simply to add the numbers on the calendar or understand it according to our common sense, then you are wrong!
In fact, with the advancement of time technology, human understanding of time has also deepened, and the length of a second has also changed.
Traditionally, we have used the time it takes for the Earth to rotate once as an hour, then an hour as a minute, and finally a minute as a second.
However, this method does not accurately measure the actual length of a second, as it is affected by a variety of external factors.
Due to changes in the Earth's gravitational pull, changes in atmospheric pressure, etc., the Earth's rotation speed will change slightly, which will affect the length of one second.
To solve this problem, scientists are constantly looking for a more stable time benchmark.
It wasn't until the 60s that they discovered one of the most stable phenomena in nature – the frequency of electron transitions – and defined it as a standard for a second.
According to this definition, 1 second is defined as the number of resonances of cesium-133 atoms under certain conditions, and this standard based on the definition of the physical properties of the atom makes one second more accurate and stable.
When we go deeper into the depths of the microcosm, we find that the division of time units becomes more subtle.
In physics, in addition to the common units of time such as seconds, milliseconds, and microseconds, there are also more elaborate units of time such as picoseconds (one trillionth of a second), femtoseconds (one quadrillion of a second), and attoseconds (one quadrillion of a second).
These units of time are particularly important when studying phenomena such as laser pulses, quantum entanglement, etc.
What's even more amazing is that when we look further into the extremely short time scales of Planck time (about 10 minus 43 seconds), we will find that time itself exhibits some peculiar properties, such as the quantum uncertainty principle.
At this scale, the concepts of time and space become blurred, leading to deep reflections on the nature of the universe.
The measurement of "one second" is not just a simple numerical problem, it reflects the deepening of human understanding of the laws of nature and the continuous progress of science and technology.
In the future, as we continue to explore the mysteries of the universe, there may be more new definitions and discoveries about time waiting to be revealed. #文章首发挑战赛#
Reference Sources:
Guangming Net - The Earth's rotation has accelerated by less than 24 hours a day, and time will pass faster in 2021 than in previous years
The earth's rotation has accelerated for less than 24 hours, netizens: Where has the time gone?
Jiupai News - The Earth's rotation speed has become faster, setting a record for the shortest day in less than 24 hours a day
Top News - The Earth "Mysterious" Accelerated Rotation, June 29 Becomes the "Shortest Day" on Record
Red Star News - The day is less than 24 hours! The Earth's "mysterious" acceleration of rotation, June 29 became the "shortest day" on record
China Youth Network - The Earth's rotation is accelerating, and the day is less than 24 hours! How long is that, why?