We are all inhabitants of the most beautiful planet in the Universe, it is called "blue" because of the abundance of water. It is in the solar system only one such, but all good sooner or later ends. Have you ever wondered if the Earth stops, what will happen? We will try to find the answer to this question in this article.
Still from the days of school, they know that our earth has the shape of a ball and rotates on its axis. It is also in continuous motion around our source of heat and light, the Sun. But what is the reason for the rotation of the Earth?
All these questions are quite interesting, for sure, every inhabitant of our planet asked this at least once in his life. The school course gives us little information of this kind. For example, everyone knows that as a result of the Earth's movement, we have a change of day and night, the air temperature is maintained, which is familiar to all of us. But all this is not enough, because this process is not limited only to this.
Rotation around the Sun
So, we figured out that our planet is always in motion, but why and at what speed does the Earth rotate? It is important to know that all the planets in the solar system rotate at a certain speed, and all in the same direction. Coincidence? Of course not!
Long before the appearance of man, our planet was formed, it arose in a hydrogen cloud. After that, there was a strong push, as a result of which the cloud began to rotate. In order to answer the question "why", remember that each particle passing through a vacuum has its own inertia, and all particles balance it.
Thus, the entire solar system rotates faster and faster. From this, our Sun was formed, and then all the other planets, and inherited from the luminary received those very movements.
Rotation around its own axis
Scientists are interested in this question even now, there are many hypotheses, but here is the most plausible one.
So, we have already said in the previous paragraph that the entire solar system was formed from the accumulation of "debris", which accumulated as a result of the fact that the young, at that time, the Sun attracted it. Despite the fact that the bulk of it went to our Sun, planets nevertheless formed around. Initially, they did not have the usual form for us.
Sometimes, colliding with objects, they collapsed, but had the ability to attract more fine particles, and gained their mass. Several factors made our planet spin:
- Time.
- Wind.
- Asymmetry.
And the last is not a mistake, then the Earth resembled the shape of a snowball made by a small child. Wrong shape forced the planet to be unstable, it was exposed to the wind and radiation of the sun. Despite, she got out of an unbalanced position and began to spin, pushed by the same factors. In short, our planet is not moving itself, but it was pushed many billions of years ago. We have not specified how fast the Earth is rotating. She is always in motion. And in almost twenty-four hours, it makes a complete revolution around its axis. This movement is called daily. The rotation speed is not the same everywhere. So at the equator, it is approximately 1670 kilometers per hour, and the North and South Poles can remain in place at all.
But besides this, our planet is also moving along a different trajectory. A complete revolution of the Earth around the Sun occurs in three hundred sixty-five days and five hours. This explains the fact that there is a leap year, that is, there is one more day in it.
Is it possible to stop?
If the Earth stops, what will happen? To begin with, the stop can be viewed both around its axis and around the Sun. We will analyze all the options in more detail. In this chapter, we will discuss some general points, and whether this is possible at all.
If we consider an abrupt stop of the Earth's rotation around its axis, then this is practically unrealistic. Only a collision with a large object can lead to this. Let us clarify right away that it will no longer make any difference whether the planet rotates or even flew away from its orbit, since such a large object can cause a stop that the Earth simply cannot withstand such a blow.
If the Earth stops, what will happen? If a sudden stop is practically impossible, then slow braking is quite possible. Although it is not felt, our planet is already gradually slowing down.
If we talk about flying around the Sun, then stopping the planet in this case is something from the realm of fantasy. But we will discard all probabilities and assume that it did happen. We suggest that you analyze each case separately.
Abrupt stop
Although this option is hypothetically impossible, we will still assume. If the Earth stops, what will happen? The speed of our planet is so great that an abrupt stop, for whatever reason, will simply blow everything on it.
To begin with, in which direction does the Earth rotate? From West to East at a speed of more than five hundred meters per second. From this we can assume that everything that moves on the planet will continue to move at a speed of more than 1.5 thousand kilometers per hour. The wind blowing at the same speed will cause a severe tsunami. On one hemisphere there will be six months a day, and then those who are not burned by the highest temperature will finish off six months of severe frost and nights. And what if they are still alive after that? Radiation will kill them. In addition, after the Earth stops, our core will make several more revolutions, while volcanoes will erupt in places where they have not been encountered before.
The atmosphere will also not stop its movement instantly, that is, there will be a wind blowing at a speed of 500 meters per second. In addition, partial loss of the atmosphere is possible.
This variant of catastrophe is the best outcome for humanity, because everything will happen so quickly that not a single person will have time to come to his senses, will not understand what is happening. Since the most likely result is the explosion of the planet. Another thing is the slow and gradual stop of the planet.
The first thing that comes to mind for many is an eternal day on one side, and an eternal night on the other, but this, in fact, is not much of a problem compared to the rest.
Smooth stop
Our planet slows down its rotation, scientists say that a person will not find its complete stop, since it will happen in billions of years, and long before that the Sun will increase in volume and simply burn the Earth. But, nevertheless, we will simulate a stop situation in the foreseeable future. Just to begin with, let's figure out the question: why is there a slow stop?
Previously, a day on our planet lasted about six hours, and the Moon has a strong effect on this factor. But how? It causes the water to vibrate with its force of attraction, and as a result of this process, a slow stop occurs.
Still happened
We are waiting for an eternal night or an eternal day in one of the hemispheres, but this is not the biggest problem compared to the redistribution of land and ocean, which will lead to the massive destruction of all life.
Where there is sun, all plants will gradually die out, and the soil will crack from drought, but the other side is the snowy tundra. The most suitable area for habitation will be intermediate, where there will be an eternal sunrise or sunset. Moreover, these territories will be quite small. The land will be located only at the equator. The North and South Pole will represent two large oceans.
It is no exception that a person will need to adapt to exist in the ground, and space suits are needed for walking on the surface.
Without movement around the sun
This scenario is simple, everything that was on the front side will fly into the free space of space, because our planet is moving at a very high speed, while others will receive an equally strong impact on the ground.
Even if the Earth gradually slows down its movement, it will eventually fall on the Sun, and this whole process will take sixty-five days, but no one will survive until the last, since the temperature will be about three thousand degrees Celsius. According to the calculations of scientists, then in a month on our planet the temperature will reach 50 degrees.
This scenario is practically unrealistic, but the absorption of the Earth by the Sun is a fact that cannot be avoided, but humanity will not be able to catch this day.
Earth flew out of orbit
This is the most fantastic option. No, we will not go on a journey through space, because there are laws of physics. If at least one planet from the solar system flies out of orbit, then it will wreak havoc in the movement of all the others, eventually falling into the "clutches" of the Sun, which will absorb it, attracting it with its mass.
The rotation of the Earth is one of the movements of the Earth, which reflects many astronomical and geophysical phenomena occurring on the surface of the Earth, in its depths, in the atmosphere and oceans, as well as in the nearby space.
The rotation of the Earth explains the change of day and night, the apparent daily movement of celestial bodies, the rotation of the swing plane of a load suspended on threads, the deviation of falling bodies to the east, etc. undermining of the right banks of rivers in the Northern Hemisphere and the left in the Southern Hemisphere of the Earth and in some features of atmospheric circulation. The centrifugal force generated by the rotation of the Earth partially explains the differences in the acceleration of gravity at the Earth's equator and poles.
To study the regularities of the Earth's rotation, two coordinate systems are introduced with a common origin at the center of the Earth's mass (Figure 1.26). The Earth system X 1 Y 1 Z 1 participates in the daily rotation of the Earth and remains stationary relative to points earth surface... The XYZ stellar coordinate system is not related to the daily rotation of the Earth. Although its origin moves in world space with some acceleration, participating in the annual motion of the Earth around the Sun in the Galaxy, but this motion of relatively distant stars can be considered uniform and rectilinear. Therefore, the motion of the Earth in this system (like any celestial object) can be studied according to the laws of mechanics for an inertial frame of reference. The XOY plane is aligned with the ecliptic plane, and the X axis is directed to the vernal equinox γ of the initial epoch. As axes earth system it is convenient to take the main axes of the Earth's inertia; another choice of axes is also possible. The position of the terrestrial system relative to the stellar system is usually determined by three Euler angles ψ, υ, φ.
Figure 1.26. Coordinate systems used to study the rotation of the Earth
Basic information about the rotation of the Earth is provided by observations of the daily motion of celestial bodies. The rotation of the Earth takes place from west to east, i.e. counterclockwise as viewed from the North Pole of the Earth.
The mean inclination of the equator to the ecliptic of the initial epoch (angle υ) is almost constant (in 1900 it was 23 ° 27 ¢ 08.26² and increased by less than 0.1² during the 20th century). The line of intersection of the Earth's equator and the ecliptic of the initial epoch (line of nodes) slowly moves along the ecliptic from east to west, moving by 1 ° 13 ¢ 57.08² per century, as a result of which the angle ψ changes by 360 ° in 25 800 years (precession). The instantaneous axis of rotation of the OR always almost coincides with the smallest axis of inertia of the Earth. The angle between these axes, according to observations made since the end of the 19th century, does not exceed 0.4².
The period of time during which the Earth makes one revolution around its axis about some point in the sky is called days. Points that determine the length of the day can be:
· The point of the vernal equinox;
· The center of the visible disk of the Sun, displaced by an annual aberration ("true Sun");
· "Middle Sun" - a fictitious point, the position of which in the sky can be calculated theoretically for any moment of time.
The three different time intervals defined by these points are called, respectively, stellar, true solar and average solar days.
The speed of rotation of the Earth is characterized by a relative value
where P s is the duration of the earth's day, T is the duration of a standard day (atomic), which is 86400 s;
- angular velocities corresponding to earth and standard days.
Since the value of ω changes only in the ninth to eighth decimal places, the values \u200b\u200bof ν are of the order of 10 -9 -10 -8.
The Earth makes one complete revolution around its axis relative to the stars in a shorter period of time than relative to the Sun, since the Sun moves along the ecliptic in the same direction in which the Earth rotates.
A sidereal day is determined by the period of rotation of the Earth around its axis with respect to any star, but since the stars have their own and, moreover, very complex motion, we agreed to count the beginning of a sidereal day from the moment of the upper culmination of the vernal equinox point, and the interval is taken as the length of a sidereal day time between two successive upper climaxes of the vernal equinox point, located on the same meridian.
Due to the phenomena of precession and nutation mutual arrangement the celestial equator and the ecliptic are constantly changing, which means that the location on the ecliptic of the vernal equinox changes accordingly. It has been established that a sidereal day is 0.0084 seconds shorter than the actual period of the Earth's diurnal rotation and that the Sun, moving along the ecliptic, reaches the vernal equinox point before it reaches the same place relative to the stars.
The Earth, in turn, revolves around the Sun not in a circle, but in an ellipse, so the movement of the Sun seems to us uneven from the Earth. In winter, the true solar days are greater than in summer, For example, at the end of December they are equal to 24 hours 04 minutes 27 seconds, and in mid-September - 24 hours 03 minutes. 36sec. 24h 03min is considered to be the average unit of a solar day. 56.5554 seconds of sidereal time.
The angular velocity of the Earth relative to the Sun due to the ellipticity of the Earth's orbit depends on the season. The slowest of all the Earth moves in its orbit, being in perihelion - the point of its orbit farthest from the Sun. As a result, the duration of the true solar day is not the same throughout the year - the ellipticity of the orbit changes the duration of the true solar day according to the law, which can be described by a sinusoid with an amplitude of 7.6 minutes. and a period of 1 year.
The second reason for the irregularity of the day is the inclination of the earth's axis to the ecliptic, leading to the apparent movement of the Sun up and down from the equator throughout the year. Right ascension of the Sun near the equinoxes (Figure 1.17) changes more slowly (since the Sun moves at an angle to the equator) than during the solstices, when it moves parallel to the equator. As a result, a sinusoidal term with an amplitude of 9.8 minutes is added to the duration of a true solar day. and a period of six months. There are other periodic effects that change the duration of a true solar day and depend on time, but they are small.
As a result of the combined action of these effects, the shortest true solar days are observed on March 26-27 and September 12-13, and the longest - on June 18-19 and December 20-21.
To eliminate this variability, the average solar day is used, tied to the so-called average Sun - a conditional point moving uniformly along the celestial equator, and not along the ecliptic, like the real Sun, and coinciding with the center of the Sun at the time of the vernal equinox. The period of revolution of the average Sun in the celestial sphere is equal to the tropical year.
Average solar days are not subject to periodic changes, like true solar days, but their duration monotonically changes due to a change in the period of the Earth's axial rotation and (to a lesser extent) with a change in the duration of the tropical year, increasing by about 0.0017 seconds per century. Thus, the duration of an average solar day at the beginning of 2000 was equal to 86400.002 SI seconds (the SI second is determined using an intra-atomic periodic process).
Sidereal days are 365.2422 / 366.2422 \u003d 0.997270 solar mean days. This value is a constant ratio of sidereal and solar time.
The mean solar time and sidereal time are related by the following relationships:
24 hours Wed solar time \u003d 24h. 03 minutes 56.555sec. sidereal time
1h \u003d 1h. 00 minutes 09.856 sec.
1 min. \u003d 1 min. 00.164 sec.
1 sec. \u003d 1.003 sec.
24 hours of sidereal time \u003d 23 hours 56 minutes. 04.091 sec. Wed solar time
1 hour \u003d 59 minutes 50.170 sec.
1 min. \u003d 59.836 sec.
1 sec. \u003d 0.997 sec.
Time in any dimension - stellar, true solar or mean solar - is different at different meridians. But all points lying on the same meridian at the same time have the same time, which is called local time. If you move west or east along the same parallel, the time at the origin will not match the local time of all other geographic points located on that parallel.
To to some extent eliminate this drawback, Canadian S. Fleshing proposed to introduce standard time, i.e. a time counting system based on dividing the Earth's surface into 24 time zones, each of which is 15 ° from the neighboring zone in longitude. Flushing mapped 24 major meridians on the world map. Approximately 7.5 ° to the east and west of them, the boundaries of the time of this zone were conditionally plotted. The time of the same time zone at every moment was considered the same for all its points.
Before Flushing, maps with different prime meridians were published in many countries around the world. For example, in Russia, longitudes were counted from the meridian passing through the Pulkovo Observatory, in France - through the Paris Observatory, in Germany - through the Berlin Observatory, in Turkey - through the Istanbul Observatory. To introduce the standard time, it was necessary to unify a single initial meridian.
Zone time was first introduced in the United States in 1883, and in 1884. in Washington at an international conference, in which Russia also took part, an agreed decision was made on the standard time. The conference participants agreed to consider the Greenwich Observatory meridian as the initial or zero meridian, and the local mean solar time of the Greenwich meridian was called universal or world time. The so-called "date line" was also established at the conference.
In our country, standard time was introduced in 1919. Taking as a basis the international system of time zones and the then existing administrative boundaries, time zones from II to XII inclusive were plotted on the RSFSR punishment. Local time in time zones located east of the Greenwich meridian increases by an hour from zone to zone, and decreases by an hour to the west of Greenwich.
When counting time in calendar days, it is important to establish on which meridian the new date begins (day of the month). According to international agreement, the date line passes for the most part along the meridian 180 ° from Greenwich, retreating from it: to the west - near Wrangel Island and the Aleutian Islands, to the east - off the coast of Asia, Fiji, Samoa, Tongatabu, Kermandek and Chatham.
To the west of the date line, the day of the month is always one more than to the east of it. Therefore, after crossing this line from west to east, it is necessary to decrease the number of the month by one, and after crossing it from east to west, increase by one. This change in the date is usually made at the nearest midnight after crossing the date line. It is quite clear that the new calendar month and new Year start on the date line.
Thus, the prime meridian and the 180 ° E meridian, along which the date line mainly passes, divide the globe into the western and eastern hemispheres.
Throughout the history of mankind, the daily rotation of the Earth has always served as an ideal standard of time, which regulated the activities of people and was a symbol of uniformity and accuracy.
The oldest instrument for determining the time before our era was a gnomon, in Greek a pointer, a vertical pillar on a leveled platform, the shadow of which, changing its direction as the sun moved, showed on a scale drawn on the ground near the pillar one or another time of day. The sundial has been known since the 7th century BC. Initially, they were distributed in Egypt and the countries of the Middle East, from where they moved to Greece and Rome, and even later penetrated the countries of Western and Eastern Europe. Astronomers and mathematicians of the ancient world, the Middle Ages and modern times were engaged in gnomonics - the art of making sundials and the ability to use them. In the 18th century. and at the beginning of the 19th century. gnomonics was presented in mathematics textbooks.
And only after 1955, when the requirements of physicists and astronomers to the accuracy of time greatly increased, it became impossible to satisfy the daily rotation of the Earth as a standard of time, already uneven with the required accuracy. The time, determined by the rotation of the Earth, is uneven due to the movements of the pole and the redistribution of the angular momentum between different parts of the Earth (hydrosphere, mantle, liquid core). The meridian adopted for timing is determined by the EOR point and the point on the equator corresponding to zero longitude. This meridian is very close to Greenwich.
The earth rotates unevenly, which causes a change in the length of the day. The speed of the Earth's rotation can be most simply characterized by the deviation of the duration of the Earth's day from the reference (86 400 s). The shorter the Earth's day, the faster the Earth rotates.
There are three components in the magnitude of the change in the rate of rotation of the Earth: secular deceleration, periodic seasonal fluctuations and irregular abrupt changes.
The secular slowdown in the Earth's rotation rate is due to the action of the tidal forces of attraction of the Moon and the Sun. The tidal force stretches the Earth along a straight line connecting its center with the center of the disturbing body - the Moon or the Sun. In this case, the compressive force of the Earth increases if the resultant coincides with the equatorial plane, and decreases when it deviates towards the tropics. The moment of inertia of the compressed Earth is greater than that of an undeformed spherical planet, and since the angular momentum of the Earth (i.e. the product of its moment of inertia and angular velocity) must remain constant, the rotation speed of the compressed Earth is less than that of an undeformed one. Due to the fact that the declination of the Moon and the Sun, the distances from the Earth to the Moon and the Sun are constantly changing, the tidal force fluctuates in time. The compression of the Earth changes accordingly, which ultimately causes tidal fluctuations in the speed of the Earth's rotation. The most significant of them are fluctuations with half-monthly and monthly periods.
The deceleration of the Earth's rotation speed is detected in astronomical observations and paleontological research. Observations of ancient solar eclipses led to the conclusion that the duration of a day every 100,000 years increases by 2 s. Paleontological observations of corals have shown that corals from warm seas grow in a belt, the thickness of which depends on the amount of light received per day. Thus, it is possible to determine the annual changes in their structure and calculate the number of days in a year. In the modern era, 365 belts are found on coral. According to paleontological observations (Table 5), the length of the day increases linearly with time by 1.9 s per 100,000 years.
Table 5
According to observations over the past 250 years, the day has increased by 0.0014 s per century. According to some data, in addition to tidal deceleration, there is an increase in the rotation speed of 0.001 s per century, which is caused by a change in the moment of inertia of the Earth due to the slow movement of matter inside the Earth and on its surface. Intrinsic acceleration reduces the length of the day. Therefore, if it were not for it, then the day would increase by 0.0024s per century.
Before the creation of the atomic clock, the rotation of the Earth was controlled by comparing the observed and calculated coordinates of the Moon, Sun, and planets. In this way, it was possible to get an idea of \u200b\u200bthe change in the rate of rotation of the Earth over the last three centuries - from the end of the 17th century, when the first instrumental observations of the movement of the Moon, the Sun and planets began to be carried out. Analysis of these data shows (Figure 1.27) that from the beginning of the 17th century. until the middle of the 19th century. the Earth's rotation rate changed little. From the second half of the 19th century. up to the present time, significant irregular fluctuations of velocity have been observed with characteristic times of the order of 60-70 years.
Figure 1.27. Deviation of the length of the day from the reference for 350 years
The fastest Earth rotated around 1870, when the duration of the Earth's day was 0.003 s shorter than the reference. The slowest - around 1903, when the Earth's day was 0.004 s longer than the reference. From 1903 to 1934 there was an acceleration of the Earth's rotation, from the end of the 30s to 1972. there was a slowdown, and since 1973. to the present, the Earth is accelerating its rotation.
Periodic annual and semi-annual fluctuations in the Earth's rotation speed are explained by periodic changes in the Earth's moment of inertia due to the seasonal dynamics of the atmosphere and the planetary distribution of atmospheric precipitation. According to modern data, the length of the day varies by ± 0.001 seconds throughout the year. At the same time, the shortest days are in July-August, and the longest - in March.
Periodic changes in the Earth's rotation rate have periods of 14 and 28 days (lunar) and 6 months and 1 year (solar). The minimum rotation speed of the Earth (acceleration is zero) corresponds to February 14, average speed (acceleration maximum) - May 28, maximum speed (acceleration is zero) - August 9, average speed (minimum deceleration) - November 6.
There are also observed random changes in the rate of rotation of the Earth, which occur at irregular intervals of time, almost multiples of eleven years. The absolute value of the relative change in the angular velocity reached in 1898. 3.9 × 10 -8, and in 1920. - 4.5 × 10 -8. The nature and nature of random fluctuations in the Earth's rotation rate are poorly understood. One of the hypotheses explains the irregular fluctuations of the angular velocity of the Earth's rotation by recrystallization of some rocks inside the Earth, which changes its moment of inertia.
Before the discovery of the unevenness of the Earth's rotation, the derived unit of measure of time - the second - was defined as 1/86400 of the average solar day. The inconstancy of the average solar day due to the uneven rotation of the Earth forced to abandon such a definition of the second.
In October 1959. The International Bureau of Weights and Measures decided to give the following definition to the fundamental unit of time, a second:
"The second is 1 / 31556925.9747 of the tropical year for 1900, January 0, at 12 o'clock ephemeris time."
The second thus defined was called "ephemeris". The number 31556925.9747 \u003d 86400´365.2421988 is the number of seconds in a tropical year, the duration of which for 1900, January 0, at 12 hours of ephemeris time (uniform Newtonian time) was 365.2421988 average solar days.
In other words, the ephemeris second is a time interval equal to 1/86400 of the average length of the average solar day, which they had in 1900, in January 0, at 12 hours of ephemeris time. Thus, the new definition of the second was associated with the movement of the Earth around the Sun, while the old definition was based only on its rotation around its axis.
Nowadays, time is a physical quantity that can be measured with the highest accuracy. The unit of time - a second of "atomic" time (SI second) - equated to the duration of 9192631770 periods of radiation corresponding to the transition between two hyperfine levels of the ground state of the cesium-133 atom, was introduced in 1967 by the decision of the XII General Conference of Weights and Measures, and in 1970 " atomic time was taken as a fundamental reference time. The relative accuracy of the cesium frequency standard is 10 -10 -10 -11 for several years. The standard of atomic time has neither daily nor secular fluctuations, does not age and has sufficient certainty, accuracy and reproducibility.
With the introduction of atomic time, the accuracy of determining the unevenness of the Earth's rotation has improved significantly. From that moment on, it became possible to register all fluctuations in the Earth's rotation speed with a period of more than one month. Figure 1.28 shows the course of average monthly deviations for the period 1955-2000.
From 1956 to 1961 the Earth's rotation was accelerating, from 1962 to 1972. - slowed down, and since 1973. to the present time - accelerated again. This acceleration is not over yet and will last until 2010. The acceleration of rotation 1958-1961. and deceleration 1989-1994. are short-term fluctuations. Seasonal fluctuations lead to the fact that the Earth's rotation rate is lowest in April and November, and highest in January and July. The January maximum is significantly less than the July maximum. The difference between the minimum deviation of the duration of the earth's day from the reference in July and the maximum in April or November is 0.001 s.
Figure 1.28. Average monthly deviations of the duration of the earth's day from the reference for 45 years
The study of the uneven rotation of the Earth, nutations of the Earth's axis and the movement of the poles is of great scientific and practical importance. Knowledge of these parameters is necessary to determine the coordinates of celestial and terrestrial objects. They contribute to the expansion of our knowledge in various fields of earth sciences.
In the 80s of the 20th century, astronomical methods for determining the parameters of the Earth's rotation were replaced by new methods of geodesy. Doppler observations of satellites, laser ranging of the Moon and satellites, global positioning system GPS, radio interferometry are effective means for studying the unevenness of the Earth's rotation and the movement of the poles. The most suitable for radio interferometry are quasars - powerful sources of radio emission of extremely small angular size (less than 0.02²), which are, apparently, the most distant objects of the Universe, practically stationary in the sky. Quasar radio interferometry is the most efficient means for studying the rotational motion of the Earth, independent of optical measurements.
It took a man many millennia to understand that the Earth is not the center of the Universe and is in constant motion.
Galileo Galilei's phrase "And yet it turns!" went down in history forever and became a kind of symbol of that era when scientists from different countries tried to refute the theory of the geocentric system of the world.
Although the Earth's rotation was proven about five centuries ago, the exact reasons driving it to move are still unknown.
Why is the Earth spinning on an axis?
In the Middle Ages, people believed that the Earth was motionless, and the Sun and other planets revolved around it. Only in the 16th century did astronomers manage to prove the opposite. Despite the fact that many associate this discovery with Galileo, in fact it belongs to another scientist - Nicolaus Copernicus.
It was he who, in 1543, wrote the treatise "On the conversion celestial spheres", Where he put forward a theory about the movement of the Earth. For a long time, this idea did not receive support either from his colleagues or from the church, but in the end it had a huge impact on the scientific revolution in Europe and became fundamental in further development astronomy. 
After the theory of the Earth's rotation was proven, scientists began to look for the causes of this phenomenon. Over the past centuries, many hypotheses have been put forward, but even today not a single astronomer can accurately answer this question.
Currently, there are three main versions that have the right to life - the theory of inertial rotation, magnetic fields and the effect of solar radiation on the planet.
The theory of inert rotation
Some scientists are inclined to believe that once (back in the time of its appearance and formation) the Earth spun, and now it rotates by inertia. Having formed from cosmic dust, it began to attract other bodies to itself, which gave it an additional impulse. This assumption applies to other planets in the solar system.
The theory has many opponents, since it cannot explain why at different times the speed of the Earth's movement either increases or decreases. It is also unclear why some of the planets of the solar system rotate in the other direction, such as Venus.
The theory of magnetic fields
If you try to connect two magnets with an equally charged pole together, they will start to repel each other. The theory of magnetic fields assumes that the poles of the Earth are also charged in the same way and, as it were, repel each other, which makes the planet spin. 
Interestingly, scientists recently made a discovery that the Earth's magnetic field pushes its inner core from west to east and makes it spin faster than the rest of the planet.
Sun exposure hypothesis
The most probable is the theory of solar radiation. It is well known that it heats up the surface shells of the Earth (air, seas, oceans), but the heating occurs unevenly, as a result of which sea and air currents are formed.
It is they who, when interacting with the solid shell of the planet, make it rotate. Continents act as turbines that determine the speed and direction of movement. If they are not monolithic enough, they begin to drift, which affects the increase or decrease in speed.
Why does the earth move around the sun?
The reason for the Earth's revolution around the Sun is called inertia. According to the theory of the formation of our star, about 4.57 billion years ago, a huge amount of dust arose in space, which gradually turned into a disk, and then into the Sun.
The outer particles of this dust began to combine with each other, forming planets. Even then, by inertia, they began to revolve around the star and continue to move along the same trajectory today. 
According to Newton's law, all cosmic bodies move in a straight line, that is, in fact, the planets of the solar system, including the Earth, should have flown away into open space long ago. But that doesn't happen.
The reason is that the Sun has a large mass and, accordingly, a huge gravity. The earth, while moving, always tries to rush away from it in a straight line, but gravitational forces pull it back, so the planet is held in orbit and revolves around the sun.
V \u003d (R e R p R p 2 + R e 2 tg 2 φ + R p 2 h R p 4 + R e 4 tg 2 φ) ω (\\ displaystyle v \u003d \\ left ((\\ frac (R_ (e) \\, R_ (p)) (\\ sqrt ((R_ (p)) ^ (2) + (R_ (e)) ^ (2) \\, (\\ mathrm (tg) ^ (2) \\ varphi)))) + (\\ frac ((R_ (p)) ^ (2) h) (\\ sqrt ((R_ (p)) ^ (4) + (R_ (e)) ^ (4) \\, \\ mathrm (tg) ^ (2) \\ varphi))) \\ right) \\ omega)where R e (\\ displaystyle R_ (e)) \u003d 6378.1 km - equatorial radius, R p (\\ displaystyle R_ (p)) \u003d 6356.8 km - polar radius.
- An airplane flying at this speed from east to west (at an altitude of 12 km: 936 km / h at the latitude of Moscow, 837 km / h at the latitude of St. Petersburg) will be at rest in the inertial frame of reference.
- The superposition of the Earth's rotation around an axis with a period of one sidereal day and around the Sun with a period of one year leads to an inequality of solar and sidereal days: the length of an average solar day is exactly 24 hours, which is 3 minutes 56 seconds longer than a sidereal day.
Physical meaning and experimental confirmation
The physical meaning of the Earth's rotation around its axis
Since any movement is relative, it is necessary to indicate a specific frame of reference with respect to which the movement of a particular body is studied. When they say that the Earth rotates around an imaginary axis, it means that it rotates relative to any inertial frame of reference, and the period of this rotation is equal to sidereal days - the period of a complete revolution of the Earth (celestial sphere) relative to the celestial sphere (Earth).
All experimental evidence for the rotation of the Earth around its axis is reduced to the proof that the frame of reference associated with the Earth is a non-inertial frame of reference of a special type - a frame of reference that rotates relative to inertial frames of reference.
Unlike inertial motion (that is, uniform rectilinear motion relative to inertial reference frames), it is not necessary to make observations over external bodies to detect non-inertial motion in a closed laboratory - such motion is detected using local experiments (that is, experiments performed inside this laboratory). In this sense of the word, non-inertial motion, including the rotation of the Earth around its axis, can be called absolute.
Forces of inertia
Centrifugal Force Effects
Dependence of the acceleration of gravity on the geographical latitude. Experiments show that the acceleration of gravity depends on the geographical latitude: the closer to the pole, the greater it is. This is due to the action centrifugal force... First, points on the earth's surface located at higher latitudes are closer to the axis of rotation and, therefore, when approaching the pole, the distance r (\\ displaystyle r) from the axis of rotation decreases, reaching zero at the pole. Second, with increasing latitude, the angle between the centrifugal force vector and the horizon plane decreases, which leads to a decrease in the vertical component of the centrifugal force.
This phenomenon was discovered in 1672, when the French astronomer Jean Richet, while on an expedition in Africa, discovered that at the equator pendulum clock go slower than in Paris. Newton soon explained this by the fact that the period of oscillation of the pendulum is inversely proportional to the square root of the acceleration of gravity, which decreases at the equator due to the action of centrifugal force.
Flattening of the Earth. The influence of centrifugal force leads to the flattening of the Earth at the poles. This phenomenon, predicted by Huygens and Newton at the end of the 17th century, was first discovered by Pierre de Maupertuis in the late 1730s as a result of processing data from two French expeditions specially equipped to solve this problem in Peru (led by Pierre Bouguer and Charles de la Condamine ) and Lapland (under the direction of Alexis Clairaut and Maupertuis himself).
Coriolis force effects: laboratory experiments
This effect should be most distinctly expressed at the poles, where the period of complete rotation of the pendulum plane is equal to the period of the Earth's rotation around the axis (sidereal day). In general, the period is inversely proportional to the sine of the geographic latitude; at the equator, the plane of oscillation of the pendulum is unchanged.
Gyroscope - a rotating body with a significant moment of inertia retains the angular momentum if there are no strong disturbances. Foucault, tired of explaining what happens to the Foucault pendulum not at the pole, developed another demonstration: the suspended gyroscope retained its orientation, which means it slowly turned relative to the observer.
Deflection of shells when firing with guns. Another observable manifestation of the Coriolis force is the deviation of the trajectories of shells (in the northern hemisphere to the right, in the southern hemisphere to the left), fired in a horizontal direction. From the point of view of the inertial frame of reference, for projectiles fired along the meridian, this is due to the dependence of the linear speed of the Earth's rotation on geographical latitude: when moving from the equator to the pole, the projectile keeps the horizontal component of the velocity unchanged, while the linear velocity of rotation of points on the earth's surface decreases , which leads to the displacement of the projectile from the meridian in the direction of the Earth's rotation. If the shot was fired parallel to the equator, then the displacement of the projectile from parallel is due to the fact that the trajectory of the projectile lies in the same plane with the center of the Earth, while the points of the earth's surface move in a plane perpendicular to the axis of rotation of the Earth. This effect (for the case of firing along the meridian) was predicted by Grimaldi in the 40s of the 17th century. and first published by Riccioli in 1651.
Deviation of freely falling bodies from the vertical. ( ) If the velocity of the body has a large vertical component, the Coriolis force is directed to the east, which leads to a corresponding deviation of the trajectory of the body freely falling (without initial velocity) from a high tower. When considered in an inertial frame of reference, the effect is explained by the fact that the top of the tower relative to the center of the Earth moves faster than the base, due to which the trajectory of the body turns out to be a narrow parabola and the body is slightly ahead of the base of the tower.
The Eötvös effect. At low latitudes, the Coriolis force when moving along the earth's surface is directed in the vertical direction and its action leads to an increase or decrease in the acceleration of gravity, depending on whether the body is moving to the west or east. This effect is named the Eötvös effect in honor of the Hungarian physicist Lorand Eötvös, who experimentally discovered it at the beginning of the 20th century.
Experiments using the law of conservation of angular momentum. Some experiments are based on the law of conservation of angular momentum: in an inertial reference frame, the magnitude of the angular momentum (equal to the product of the moment of inertia and the angular velocity of rotation) does not change under the action of internal forces. If at some initial moment of time the installation is motionless relative to the Earth, then the speed of its rotation relative to the inertial frame of reference is equal to the angular speed of rotation of the Earth. If you change the moment of inertia of the system, then the angular velocity of its rotation should change, that is, rotation relative to the Earth will begin. In a non-inertial frame of reference associated with the Earth, rotation occurs as a result of the action of the Coriolis force. This idea was proposed by the French scientist Louis Poinseau in 1851.
The first such experiment was carried out by Hagen in 1910: two weights on a smooth crossbar were installed motionlessly relative to the Earth's surface. Then the distance between the weights was reduced. As a result, the installation began to rotate. An even more graphic experiment was made by the German scientist Hans Bucka in 1949. A rod, approximately 1.5 meters long, was installed perpendicular to a rectangular frame. Initially, the rod was horizontal, the installation was motionless relative to the Earth. Then the rod was brought to a vertical position, which led to a change in the moment of inertia of the installation by about 10 4 times and its rapid rotation with an angular velocity 10 4 times higher than the Earth's rotation speed.
Funnel in the bath.
Since the Coriolis force is very weak, it has a negligible effect on the direction of swirling of water when draining in a sink or bathtub, therefore, in general, the direction of rotation in a funnel is not related to the rotation of the Earth. Only in carefully controlled experiments can the effect of the Coriolis force be separated from other factors: in the northern hemisphere, the funnel will be twisted counterclockwise, in the southern hemisphere, vice versa.
Coriolis force effects: phenomena in the natural environment
Optical experiments
A number of experiments demonstrating the rotation of the Earth are based on the Sagnac effect: if a ring interferometer rotates, then due to relativistic effects, a phase difference appears in the opposite rays
Δ φ \u003d 8 π A λ c ω, (\\ displaystyle \\ Delta \\ varphi \u003d (\\ frac (8 \\ pi A) (\\ lambda c)) \\ omega,)where A (\\ displaystyle A) - the area of \u200b\u200bthe projection of the ring on the equatorial plane (the plane perpendicular to the axis of rotation), c (\\ displaystyle c) - the speed of light, ω (\\ displaystyle \\ omega) - angular velocity of rotation. To demonstrate the rotation of the Earth, this effect was used by the American physicist Michelson in a series of experiments staged in 1923-1925. In modern experiments using the Sagnac effect, the rotation of the Earth must be taken into account for the calibration of ring interferometers.
There are a number of other experimental demonstrations of the Earth's diurnal rotation.
Irregularity of rotation
Precession and nutation
The history of the idea of \u200b\u200bthe Earth's diurnal rotation
Antiquity
The explanation of the diurnal rotation of the firmament by the rotation of the Earth around the axis was first proposed by representatives of the Pythagorean school, the Syracusans Giketus and Ekfant. According to some reconstructions, the rotation of the Earth was also stated by the Pythagorean Philolaus of Croton (5th century BC). A statement that can be interpreted as an indication of the rotation of the Earth is contained in the Platonic dialogue Timaeus .
However, practically nothing is known about Giket and Ekfant, and even their very existence is sometimes questioned. According to the majority of scientists, the Earth in the system of the world of Philolaus did not rotate, but translate around the Central Fire. In his other works, Plato follows the traditional view of the immobility of the Earth. However, numerous evidences have come down to us that the idea of \u200b\u200bthe Earth's rotation was defended by the philosopher Heraclides of Pontus (IV century BC). Probably, another hypothesis of Heraclides is connected with the hypothesis of the rotation of the Earth around the axis: each star is a world, including earth, air, ether, and all this is located in infinite space. Indeed, if the diurnal rotation of the sky is a reflection of the rotation of the Earth, then the premise of considering the stars to be on the same sphere disappears.
About a century later, the assumption about the rotation of the Earth became part of the first, proposed by the great astronomer Aristarchus of Samos (III century BC). Aristarchus was supported by the Babylonian Seleucus (II century BC), as well as Heraclides of Pontus, who considered the Universe to be infinite. The fact that the idea of \u200b\u200bthe daily rotation of the Earth had its supporters back in the 1st century AD. e., evidenced by some statements of the philosophers Seneca, Derkillides, astronomer Claudius Ptolemy. The vast majority of astronomers and philosophers, however, did not doubt the immobility of the Earth.
Arguments against the idea of \u200b\u200bthe earth's movement are found in the works of Aristotle and Ptolemy. So, in his treatise About Heaven Aristotle substantiates the immobility of the Earth by the fact that on a rotating Earth, bodies thrown vertically upward could not fall to the point from which their movement began: the surface of the Earth would move under the thrown body. Another argument in favor of the immobility of the Earth, given by Aristotle, is based on his physical theory: the Earth is a heavy body, and heavy bodies tend to move towards the center of the world, and not rotation around it.
From the work of Ptolemy it follows that the supporters of the hypothesis of the rotation of the Earth to these arguments responded that both the air and all earthly objects move together with the Earth. Apparently, the role of air in this reasoning is fundamentally important, since it is implied that it is precisely its movement with the Earth that hides the rotation of our planet. Ptolemy objects to this that
bodies in the air will always seem to lag behind ... And if the bodies rotated together with the air as one whole, then none of them would seem to be ahead of the other or lagging behind it, but would remain in place, in flight and throwing it would not make deviations or movements to another place like those that we see with our own eyes taking place, and they would not slow down or accelerate at all, because the Earth is not motionless.
Middle Ages
India
The first of the medieval authors to suggest the rotation of the Earth around its axis was the great Indian astronomer and mathematician Aryabhata (late 5th - early 6th centuries). He formulates it in several passages of his treatise. Ariabhatia, eg:
Just as a person on a ship moving forward sees fixed objects moving backward, so an observer ... sees fixed stars moving in a straight line to the west.
It is not known whether this idea belongs to Ariabhata himself or whether he borrowed it from the ancient Greek astronomers.
Aryabhatu was supported by only one astronomer, Prthudaka (9th century). Most Indian scientists advocated the immobility of the earth. So, the astronomer Varahamihira (6th century) argued that on a rotating Earth, birds flying in the air could not return to their nests, and stones and trees would fly off the surface of the Earth. The eminent astronomer Brahmagupta (VI century) also repeated the old argument that a body that fell from a high mountain, but could descend to its base. At the same time, however, he rejected one of Varahamihira's arguments: in his opinion, even if the Earth rotated, objects could not be torn off from it due to their gravity.
Islamic East
The possibility of the Earth's rotation was considered by many scientists of the Muslim East. Thus, the famous geometer al-Sijizi invented the astrolabe, the principle of which is based on this assumption. Some Islamic scholars (whose names have not reached us) have even found the correct way to refute the main argument against the rotation of the Earth: the verticality of the trajectories of falling bodies. In essence, at the same time, the principle of superposition of movements was expressed, according to which any movement can be decomposed into two or more components: with respect to the surface of the rotating Earth, the falling body moves along a plumb line, but the point that is the projection of this line onto the surface of the Earth would be transferred by it rotation. This is evidenced by the famous scientist-encyclopedist al-Biruni, who himself, however, tended to the immobility of the Earth. In his opinion, if some additional force acts on the falling body, then the result of its action on the rotating Earth will lead to some effects that are not actually observed.
Among the scientists of the XIII-XVI centuries, associated with the Maraginskaya and Samarkand observatories, a discussion arose about the possibility of an empirical substantiation of the immobility of the Earth. Thus, the famous astronomer Qutb al-Din ash-Shirazi (XIII-XIV centuries) believed that the immobility of the Earth can be verified by experiment. On the other hand, the founder of the Maragha observatory Nasir ad-Din at-Tusi believed that if the Earth rotated, this rotation would be separated by a layer of air adjacent to its surface, and all movements near the Earth's surface would occur in exactly the same way as if the Earth was motionless. He substantiated this with the help of observations of comets: according to Aristotle, comets are a meteorological phenomenon in the upper atmosphere; nevertheless, astronomical observations show that comets take part in the daily rotation of the celestial sphere. Consequently, the upper layers of the air are carried away by the rotation of the firmament, therefore, the lower layers can also be carried away by the rotation of the Earth. Thus, the experiment cannot answer the question of whether the Earth rotates. However, he remained a supporter of the immobility of the Earth, as this was consistent with the philosophy of Aristotle.
Most of the Islamic scholars of later times (al-Urdi, al-Qazwini, al-Naysaburi, al-Jurjani, al-Birjandi and others) agreed with at-Tusi that all physical phenomena on a rotating and stationary Earth would proceed in the same way. However, the role of air in this was no longer considered fundamental: not only air, but all objects are carried by the rotating Earth. Consequently, to substantiate the immobility of the Earth, it is necessary to involve the teachings of Aristotle.
A special position in these disputes was taken by the third director of the Samarkand Observatory, Alauddin Ali al-Kushchi (15th century), who rejected the philosophy of Aristotle and considered the rotation of the Earth to be physically possible. In the 17th century, the Iranian theologian and encyclopedic scholar Baha ad-Din al-Amili came to a similar conclusion. In his opinion, astronomers and philosophers have not presented sufficient evidence to refute the rotation of the Earth.
Latin West
A detailed discussion of the possibility of the Earth's movement is widely contained in the writings of the Parisian scholastics Jean Buridan, Albert of Saxony, and Nicholas Orem (second half of the XIV century). The most important argument in favor of the rotation of the Earth, and not the sky, given in their works, is the smallness of the Earth in comparison with the Universe, which makes the attribution of the daily rotation of the firmament of the Universe extremely unnatural.
However, all of these scientists ultimately rejected the Earth's rotation, albeit on different grounds. Thus, Albert of Saxony believed that this hypothesis was unable to explain the observed astronomical phenomena. Buridan and Orem justly disagreed with this, according to which celestial phenomena should occur in the same way regardless of whether the Earth or the Cosmos rotates. Buridan was able to find only one significant argument against the rotation of the Earth: arrows fired vertically upward fall down a plumb line, although when the Earth rotates, they, in his opinion, should lag behind the movement of the Earth and fall west of the point of shot.
But even this argument was rejected by Orem. If the Earth rotates, then the arrow flies vertically upwards and at the same time moves to the east, being captured by the air rotating with the Earth. Thus, the arrow must fall in the same place from where it was fired. Although the entrainment role of air is again mentioned here, it really does not play a special role. This is indicated by the following analogy:
Similarly, if the air were closed in a moving ship, then a person surrounded by this air would seem that the air does not move ... If a person was in a ship moving at high speed to the east, not knowing about this movement, and if he stretched out his hand in a straight line along the mast of the ship, it would have seemed to him that his hand was doing straight motion; in the same way, according to this theory, it seems to us that the same thing happens to an arrow when we shoot it vertically up or vertically down. Inside a ship moving eastward at high speed, all kinds of motion can take place: longitudinal, lateral, down, up, in all directions - and they seem exactly the same as when the ship is stationary.
Orem goes on to provide a formulation that anticipates the principle of relativity:
I conclude, therefore, that it is impossible by any experience to demonstrate that the heavens have diurnal motion and that the earth does not.
However, Orem's final verdict on the possibility of the Earth's rotation was negative. The basis for this conclusion was the text of the Bible:
However, everyone still supports and I believe that it is they [Heaven] and not the Earth that is moving, for “God created the circle of the Earth that will not shake,” despite all opposing arguments.
Medieval European scientists and philosophers of later times also mentioned the possibility of the Earth's diurnal rotation, but no new arguments were added that were not contained in Buridan and Orem.
Thus, virtually none of the medieval scientists ever accepted the hypothesis of the Earth's rotation. However, in the course of its discussion, scientists of the East and West expressed many deep thoughts, which will then be repeated by scientists of the modern era.
Renaissance and modern times
In the first half of the 16th century, several works were published, claiming that the reason for the daily rotation of the firmament was the rotation of the Earth around its axis. One of them was the treatise of the Italian Celio Calcagnini "On the fact that the sky is motionless, and the earth rotates, or about the eternal motion of the earth" (written about 1525, published in 1544). He did not make a big impression on his contemporaries, since by that time the fundamental work of the Polish astronomer Nicolaus Copernicus "On the rotations of the celestial spheres" (1543) had already been published, where the hypothesis of the diurnal rotation of the Earth became part of the heliocentric system of the world, as in Aristarchus of Samos ... Copernicus previously outlined his thoughts in a small handwritten essay Small Commentary (not earlier than 1515). Two years earlier, the main work of Copernicus was published by the German astronomer Georg Joachim Rethick First narration (1541), where Copernicus' theory is popularly stated.
In the 16th century, Copernicus was fully supported by astronomers Thomas Digges, Rethick, Christoph Rothman, Michael Möstlin, physicists Giambatista Benedetti, Simon Stevin, philosopher Giordano Bruno, theologian Diego de Zuniga. Some scientists accepted the rotation of the Earth around its axis, rejecting its translational motion. This was the position of the German astronomer Nicholas Reimers, also known as Ursus, as well as the Italian philosophers Andrea Cesalpino and Francesco Patrizi. The point of view of the outstanding physicist William Hilbert, who supported the axial rotation of the Earth, but did not speak out about its translational motion, is not entirely clear. At the beginning of the 17th century, the heliocentric system of the world (including the rotation of the Earth around its axis) received impressive support from Galileo Galilei and Johannes Kepler. The most influential opponents of the idea of \u200b\u200bthe Earth's motion in the 16th and early 17th centuries were the astronomers Tycho Brahe and Christopher Clavius.
The hypothesis of the Earth's rotation and the formation of classical mechanics
In fact, in the XVI-XVII centuries. the only argument in favor of the axial rotation of the Earth was that in this case there is no need to ascribe to the stellar sphere huge speeds of rotation, because even in antiquity it was already reliably established that the size of the Universe significantly exceeds the size of the Earth (this argument was contained even by Buridan and Orem) ...
This hypothesis was opposed by considerations based on the dynamic concepts of the time. First of all, it is the verticality of the trajectories of the falling bodies. Other arguments appeared, for example, equal firing range in the east and west directions. Answering the question about the unobservability of the effects of diurnal rotation in terrestrial experiments, Copernicus wrote:
Not only the Earth with the water element connected to it rotates, but also a considerable part of the air and everything that is in some way akin to the Earth, or the air already closest to the Earth saturated with earth and water matter, follows the same laws of nature as Earth, or has acquired motion, which is imparted to it by the adjacent Earth in constant rotation and without any resistance
Thus, the main role in the unobservability of the Earth's rotation is played by the entrainment of air by its rotation. Most of the Copernicans in the 16th century were of the same opinion.
The supporters of the infinity of the Universe in the 16th century were also Thomas Digges, Giordano Bruno, Francesco Patrizi - all of them supported the hypothesis of the rotation of the Earth around an axis (and the first two also around the Sun). Christoph Rothman and Galileo Galilei believed the stars to be located at different distances from the Earth, although they clearly did not speak out about the infinity of the universe. On the other hand, Johannes Kepler denied the infinity of the universe, although he was a supporter of the rotation of the Earth.
The Religious Context of the Earth Rotation Controversy
A number of objections to the rotation of the Earth were associated with its contradictions with the text of the Holy Scriptures. These objections were of two kinds. Firstly, some passages in the Bible were cited in confirmation that the daily movement is made by the Sun, for example:
The sun rises and the sun sets, and hurries to its place, where it rises.
In this case, the axial rotation of the Earth was hit, since the movement of the Sun from east to west is part of the daily rotation of the sky. A passage from the book of Joshua was often quoted in this connection:
Jesus cried to the Lord on the day that the Lord delivered the Amorite into the hands of Israel, when he killed them in Gibeon, and they were slain before the children of Israel, and said before the Israelites: Stand, the sun, over Gibeon, and the moon, over the valley of Avalon. !
Since the command to stop was given to the Sun, and not to the Earth, it was concluded from this that it is the Sun that makes the daily motion. Other passages have been cited to support the immobility of the earth, for example:
You have set the earth on solid foundations: it will not shake forever and ever.
These passages were considered to contradict both the opinion about the rotation of the Earth around its axis and the rotation around the Sun.
Supporters of the Earth's rotation (in particular, Giordano Bruno, Johannes Kepler and especially Galileo Galilei) defended in several directions. First, they pointed out that the Bible is written in language that common people, and if its authors gave clear formulations from a scientific point of view, it would not be able to fulfill its main, religious mission. So, Bruno wrote:
In many cases, it is foolish and inappropriate to bring a lot of reasoning more in accordance with the truth than in accordance with the given case and convenience. For example, if instead of the words: "The sun is born and rises, passes through noon and leans towards Aquilon" - the sage said: "The earth goes in a circle to the east and, leaving the sun, which is setting, bends towards two tropics, from Cancer to the South, from Capricorn to Aquilon, "- then the listeners would start thinking:" How? Does he say the earth is moving? What is this news? " In the end they would think him a fool, and he really would be a fool.
Answers of this kind were given mainly to objections concerning the diurnal motion of the Sun. Secondly, it was noted that certain passages of the Bible should be interpreted allegorically (see the article Biblical Allegorism). So, Galileo noted that if Holy Scripture is taken entirely literally, it turns out that God has hands, he is subject to emotions such as anger, etc. In general, the main thought of the defenders of the doctrine of the movement of the Earth was that science and religion have different goals: science examines the phenomena of the material world, guided by the arguments of reason, the goal of religion is the moral improvement of man, his salvation. Galileo in this connection quoted Cardinal Baronio that the Bible teaches how to ascend to heaven, not how heaven works.
These arguments were considered unconvincing by the Catholic Church, and in 1616 the doctrine of the rotation of the Earth was banned, and in 1631 Galileo was convicted by the Inquisition for his defense. However, outside Italy, this prohibition did not have a significant impact on the development of science and contributed mainly to the decline of the authority of the Catholic Church itself.
It should be added that religious arguments against the movement of the Earth were brought not only by church leaders, but also by scientists (for example, Tycho Brahe). On the other hand, the Catholic monk Paolo Foscarini wrote a small essay "Letter on the views of the Pythagoreans and Copernicus on the mobility of the Earth and the immobility of the Sun and on the new Pythagorean system of the universe" (1615), where he expressed considerations close to Galilean, and the Spanish theologian Diego de Zuniga even used Copernicus's theory to interpret certain passages of Scripture (although he later changed his mind). Thus, the conflict between theology and the doctrine of the movement of the Earth was not so much a conflict between science and religion as such, as a conflict between the old (by the beginning of the 17th century, already obsolete) and new methodological principles, which were the basis of science.
The value of the hypothesis of the rotation of the Earth for the development of science
Comprehension of scientific problems raised by the theory of a rotating Earth contributed to the discovery of the laws of classical mechanics and the creation of a new cosmology, which is based on the idea of \u200b\u200bthe infinity of the Universe. Discussed during this process, the contradictions between this theory and the literalist reading of the Bible contributed to the demarcation of natural science and religion.
It is interesting that all the planets of the solar system do not stand still, but rotate in one direction or another. Most of them are "in solidarity" with the Sun in this respect. spinning in the opposite direction to the clockwise direction, as seen with an Exception are Venus and Uranus spinning in the opposite direction. Moreover, if everything is clear with Venus, then the second planet has some problems with determining the direction, because scientists did not come to a consensus as to which pole is north and which is south because of the large tilt of the axis. The sun rotates around its axis at a speed of 25-35 days, and this difference is explained by the fact that the rotation is slower at the pole.
The problem of how the Earth rotates (around its axis) has several solutions. Firstly, some believe that the planet rotates under the influence of the energy of the star in our system, i.e. The sun. It heats up huge water and air masses, which act on the solid component, providing rotation at one speed or another for long periods of time. Proponents of this theory suggest that the force of impact may be such that if the solid component of the planet is not strong enough, then continental drift may occur. In defense of the theory, it says that planets with matter in three different states (solid, liquid, gaseous) rotate faster than those with two states. The researchers also note that on the approach to the Earth, a huge power of solar radiation is formed, and the power of the Gulf Stream in the open ocean is more than 60 times higher than the power of all rivers on the planet.
The most common answer to the question: "How does the Earth rotate during the day?" - is the assumption that this rotation has been preserved since the formation of planets from gas and dust clouds with the participation of others that crashed into the surface.
Representatives of various scientific (and not only) directions tried to find out what is connected with the around the axis. Some believe that for such a uniform rotation, certain external forces of an unknown nature are applied to it. Newton, for example, believed that the world often "needs fixing." Today it is assumed that such forces can operate in the Southern region and at the southern end of the Verkhoyansk ridge of Yakutia. It is assumed that in these places the earth's crust is "attached" to the inner part by bridges, preventing it from slipping along the mantle. Scientists are based on the fact that in these places interesting bends of mountain ranges on land and under water have been discovered, which have arisen under the influence of enormous forces acting in earth crust and under it.
It is no less interesting how the force of gravity acts here and thanks to which the planet is kept in its orbit like a ball twisted on a string. As long as these forces are balanced, we will not "fly away" into deep space, or, conversely, will not fall on the luminary. The way the Earth rotates, no other planet rotates. A year, for example, on Mercury lasts about 88 Earth days, and on Pluto - a quarter of a millennium (247, 83 Earth years).