Like other planets solar system, makes 2 main movements: around its own axis and around the Sun. Since ancient times, it is on these two regular movements that the calculation of time and the ability to draw up calendars have been based.

A day is the time of rotation around its own axis. A year is a revolution around the sun. The division into months is also in direct connection with astronomical phenomena - their duration is associated with the phases of the moon.

Rotation of the Earth around its own axis

Our planet rotates around its own axis from west to east, that is, counterclockwise (when viewed from the side North Pole.) An axis is a virtual straight line crossing the globe in the region of the North and South Poles, i.e. the poles have a fixed position and do not participate in rotational motion, while all other locations on earth's surface rotate, and the rotation speed is not identical and depends on their position relative to the equator - the closer to the equator, the higher the rotation speed.

For example, in the region of Italy, the rotation speed is approximately 1200 km / h. The consequences of the rotation of the Earth around its axis are the change of day and night and the apparent movement of the celestial sphere.

Indeed, one gets the impression that the stars and others celestial bodies of the night sky move in the opposite direction to our movement with the planet (that is, from east to west).

It seems that the stars are located around the North Star, which is located on an imaginary line - a continuation of the earth's axis in a northerly direction. The movement of the stars is not evidence that the Earth rotates on its axis, because this movement could be a consequence of the rotation of the celestial sphere, if we assume that the planet occupies a fixed, motionless position in space.

Foucault pendulum

Irrefutable proof that the Earth rotates around its own axis was presented in 1851 by Foucault, who conducted the famous pendulum experiment.

Imagine that, being at the North Pole, we set a pendulum in oscillatory motion. The external force acting on the pendulum is gravity, while it does not affect the change in the direction of oscillation. If we prepare a virtual pendulum that leaves tracks on the surface, we can make sure that after a while the tracks move in a clockwise direction.

This rotation can be associated with two factors: either with the rotation of the plane on which the pendulum oscillates, or with the rotation of the entire surface.

The first hypothesis can be rejected, taking into account that there are no forces on the pendulum capable of changing the plane of oscillatory motions. It follows from this that it is the Earth that rotates, and it makes movements around its own axis. This experiment was carried out in Paris by Foucault, he used a huge pendulum in the form of a bronze sphere weighing about 30 kg, suspended from a 67-meter cable. The starting point of oscillatory movements was fixed on the surface of the floor of the Pantheon.

So, it is the Earth that rotates, and not the celestial sphere. People observing the sky from our planet fix the movement of both the Sun and the planets, i.e. All objects in the universe are in motion.

Time criterion - day

A day is the length of time it takes for the Earth to complete one rotation around its own axis. There are two definitions of the term “day”. A "solar day" is the time interval of the Earth's rotation, in which . Another concept - "sidereal day" - implies a different starting point - any star. The duration of the two types of day is not identical. The longitude of a sidereal day is 23 h 56 min 4 s, while the longitude solar days equals 24 hours.

The different duration is due to the fact that the Earth, rotating around its own axis, also performs an orbital rotation around the Sun.

In principle, the duration of a solar day (although it is taken as 24 hours) is a variable value. This is due to the fact that the movement of the Earth in its orbit occurs at a variable speed. When the Earth is closer to the Sun, the speed of its movement in orbit is higher, as it moves away from the sun, the speed decreases. In this regard, such a concept as “average solar day” was introduced, namely, their duration is 24 hours.

Circulation around the Sun at a speed of 107,000 km / h

The speed of the Earth around the Sun is the second main movement of our planet. The earth moves in an elliptical orbit, i.e. the orbit is elliptical. When it is in close proximity to the Earth and falls into its shadow, eclipses occur. The average distance between the Earth and the Sun is approximately 150 million kilometers. Astronomy uses a unit to measure distances within the solar system; it is called the “astronomical unit” (AU).

The speed at which the Earth moves in its orbit is approximately 107,000 km/h.
The angle formed by the earth's axis and the plane of the ellipse is approximately 66 ° 33 ', this is a constant value.

If you observe the Sun from the Earth, it seems that it is it that moves across the sky during the year, passing through the stars and that make up the Zodiac. In fact, the Sun also passes through the constellation Ophiuchus, but it does not belong to the Zodiac circle.

The earth is constantly in motion: it rotates around its axis and around the sun. It is thanks to this that on Earth there is a change of day and night, as well as a change of seasons. Let's talk in more detail about how fast the Earth moves around its axis and what is the speed of the Earth around the Sun.

At what speed does the earth rotate?

In 23 hours, 56 minutes and 4 seconds, our planet makes a complete revolution around its axis, so this rotation is called daily. Everyone knows that during a given period of time on Earth, day has time to change into night.

At the equator, the highest speed of rotation, it is equal to 1670 km / h. But this speed cannot be called constant, since it varies in different places on the planet. For example, the lowest speed is at the North and South Poles - it can drop to zero.

The speed of rotation of the Earth around the Sun is approximately 108,000 km / h or 30 km / s. In orbit around the Sun, our planet overcomes 150 ml. km. Our planet makes a complete revolution around the star in 365 days, 5 hours, 48 ​​minutes, 46 seconds, so every fourth year is a leap year, that is, one day longer.

The speed of the Earth is considered a relative value: it can only be calculated relative to the Sun, its own axis, milky way. It is unstable and tends to change in relation to another space object.

An interesting fact is that the duration of the day in April and November differs from the standard ones by 0.001 s.

The earth rotates around an inclined axis from west to east. Half of the globe is illuminated by the sun, it is day there at this time, the other half is in the shade, there is night. Due to the rotation of the Earth, there is a change of day and night. The Earth makes one revolution around its axis in 24 hours - a day.

Due to rotation, moving streams (rivers, winds) in the northern hemisphere are deflected to the right, and in the southern hemisphere - to the left.

Rotation of the Earth around the Sun

The Earth revolves around the sun in a circular orbit, a complete revolution takes 1 year. The Earth's axis is not vertical, it is inclined at an angle of 66.5° to the orbit, this angle remains constant during the entire rotation. The main consequence of this rotation is the change of seasons.

Consider the rotation of the Earth around the Sun.

• December 22- winter solstice. Closest to the sun (the sun is at its zenith) at this moment is the southern tropic - therefore, summer is in the southern hemisphere, winter is in the northern hemisphere. The nights in the southern hemisphere are short, at the southern polar circle on December 22 the day lasts 24 hours, the night does not come. In the Northern Hemisphere, the opposite is true; in the Arctic Circle, the night lasts 24 hours.
• 22nd of June- the day of the summer solstice. The northern tropic is closest to the sun, in the northern hemisphere it is summer, in the southern hemisphere it is winter. In the southern polar circle, night lasts 24 hours, and in the northern polar circle, night does not come at all.
• March 21, September 23- the days of the spring and autumn equinoxes. The equator is closest to the sun, the day is equal to the night in both hemispheres.

Full rotation around its axis, i.e. 360° turn, the globe makes 4.1 seconds in 23 hours 56 minutes, i.e. approximately in ~ 24 hours, or per day. With the same period, the sunrise, its culmination, and sunset occur. For a long time, astronomers believed that the speed of the Earth's rotation was constant, but with the use of more accurate instruments, small deviations were found. Due to the friction generated by the sea tides and changes in the earth's crust, the speed of the earth's rotation is decreasing. Our day lengthens by 1/1000 of a second every 100 years. It's a tiny change, but scientists are watching it.

The Earth moves unevenly in its orbit around the Sun. At some points it is closer to the Sun, at others it is farther. The Earth's orbit is not a circle, it is slightly elongated in shape and resembles an oval. Mathematicians call such a figure an ellipse. When the Earth is as close as possible to the Sun, this position is called perihelion (point 1), when it is as far away as possible - aphelion (point 2). The speed of the Earth's movement depends on its distance from the Sun. The closer to the Sun, the faster the speed. At perihelion, the Earth's orbital speed is 30.2 km/s. The Earth passes this point in December, and at aphelion the Earth in June and its speed is 29.2 km / s.

The air "fur coat" of our Earth is called the atmosphere. Without it, life on Earth is impossible. On those planets where there is no atmosphere, there is no life. The atmosphere protects the planet from hypothermia and overheating. It infuriates 5 million billion tons. We breathe its oxygen carbon dioxide plants absorb. “Fur Coat” protects all living beings from the destructive hail of cosmic fragments that burn on the way…

The vegetation of deserts is very peculiar and depends on the type of desert, on the characteristics of the climate and the presence of moisture. First, the vegetation does not form a continuous cover anywhere. Secondly, in the desert there are no forests, no undergrowth, no grass, and, finally, large shrubs have no leaves. Sandy deserts are the richest in herbaceous vegetation. In the gypsum and rocky deserts, shrubs, semi-shrubs and sagebrush predominate….

Earth's crust- outer layer globe, the surface on which we live, consists of about 20 large and small plates, which are called tectonic. The plates are 60 to 100 kilometers thick and seem to float on the surface of a viscous, paste-like molten substance called magma. The word "magma" is translated from Greek as "dough" or ...

The aurora borealis is one of the most beautiful, grandiose and majestic phenomena of nature. Some people think that it only occurs in the North and call it “ northern lights". And this is wrong, because it is observed with equal success both in the northern and in the southern polar and circumpolar regions. Here is how the well-known explorer of Severnaya Zemlya figuratively describes it...

Time is constantly flowing, and everything in the world changes with time. The need to measure time in people appeared a very long time ago, everyday life is connected with the change of day and night. In ancient times, the position of the Sun in the sky served as a time indicator for man. By the Sun they were guided both in space and in time. The apparent movement of the Sun across the sky allowed a person to measure almost equal ...

The word “zodiac” is based on the Greek words “animal” and “circle”. Thus, its literal translation means "circle of animals". Indeed, 11 of the 12 zodiac constellations (with the exception of Libra) bear the names of living beings: Aries, Taurus, Gemini, Cancer, Leo, Virgo, Scorpio, Sagittarius, Capricorn, Aquarius, Pisces. Against the background of precisely these constellations, the apparent movement of the Sun, Moon and planets occurs ....

For a long time, almost one and a half millennia, the teachings of Ptolemy dominated the minds of people, stating that the Earth rests motionlessly in the center of the Universe. The geocentric system of Ptolemy was refuted by the great Polish scientist Nicolaus Copernicus (1473-1543). After thirty years of hard work, long observations of the sky, complex mathematical calculations, he proved that the Earth is only one of the planets, that all planets revolve around ...

American astronauts and our automatic station Luna-16 delivered samples of lunar soil to Earth. Analysis of these samples showed that the surface rocks on the Moon were formed as a result of a solidified basaltic melt. The lunar seas are plains once flooded with volcanic lava. The Moon, like the Earth, is made up of a crust, mantle, and core. The average thickness of the crust is about 60 km. Thickness…

The spectrum tells us about it. sun rays. Sunlight is a mixture of rays of different colors. This was first established by the great English physicist I. Newton. He took a glass prism and directed a beam of light at it. Instead of a white stripe, a wide multi-colored stripe appeared on the screen behind the prism. The colors alternated in the same order as the rainbow on ...

Venus is the sorceress of the firmament, she is brighter than the brightest of the stars. It can be seen even with the naked eye in daylight. The surface of Venus, the closest to the Earth of all the planets, is inaccessible to optical observations, since the planet is shrouded in clouds. Therefore, the vast majority physical characteristics planets obtained using radio methods and space research. How very bright object visible...

V = (R e R p R p 2 + R e 2 t g 2 φ + R p 2 h R p 4 + R e 4 t g 2 φ) ω (\displaystyle v=\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))= 6378.1 km - equatorial radius, R p (\displaystyle R_(p))= 6356.8 km - polar radius.

• An aircraft 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 rotation of the Earth around its 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 the average solar day is exactly 24 hours, which is 3 minutes 56 seconds longer than the sidereal day.

Physical meaning and experimental confirmation

The physical meaning of the rotation of the Earth around its axis

Since any movement is relative, it is necessary to indicate a specific frame of reference, relative to which the movement of a body is being studied. When they say that the earth rotates around an imaginary axis, it means that it makes rotary motion relative to any inertial frame 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 of 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 special kind- a frame of reference that performs a rotational motion relative to inertial frames of reference.

Unlike inertial motion (that is, uniform rectilinear motion relative to inertial frames of reference), to detect non-inertial motion of a closed laboratory, it is not necessary to make observations over external bodies, - such movement is detected with the help of 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

Effects of centrifugal force

Dependence of free fall acceleration on geographic latitude. Experiments show that the acceleration free fall depends on geographic latitude: the closer to the pole, the greater it is. This is due to the action of centrifugal force. First, points on the earth's surface located at higher latitudes are closer to axes of rotation and, consequently, when approaching the pole, the distance r (\displaystyle r) decreases from the axis of rotation, reaching zero at the pole. Secondly, 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 to Africa, discovered that pendulum clocks run slower near the equator than in Paris. Newton soon explained this by saying that the period of a pendulum is inversely proportional to square root from the acceleration due to 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 oblateness 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 (led by Alexis Clero and Maupertuis himself).

Coriolis Force Effects: Laboratory Experiments

This effect should be most clearly 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 its axis (sidereal days). In the general case, the period is inversely proportional to the sine of geographic latitude, at the equator the plane of the pendulum's oscillations is unchanged.

Gyroscope- a rotating body with a significant moment of inertia retains an angular momentum if there are no strong perturbations. Foucault, who was tired of explaining what happened to a Foucault pendulum not at the pole, developed another demonstration: a suspended gyroscope kept its orientation, which means it slowly rotated relative to the observer.

Deflection of projectiles during gun firing. Another observable manifestation of the Coriolis force is the deflection of the trajectories of projectiles (to the right in the northern hemisphere, to the left in the southern hemisphere) 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 velocity of the Earth's rotation on geographic latitude: when moving from the equator to the pole, the projectile retains the horizontal component of the velocity unchanged, while the linear velocity of rotation of points on the earth's surface decreases , which leads to a 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 the parallel is due to the fact that the trajectory of the projectile lies in the same plane with the center of the Earth, while points on the earth's surface move in a plane perpendicular to the axis of rotation of the Earth. This effect (for the case of shooting along the meridian) was predicted by Grimaldi in the 40s years XVII V. and first published by Riccioli in 1651.

Deviation of freely falling bodies from the vertical. ( ) If the speed 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 a 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.

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 free fall, depending on whether the body moves to the west or east. This effect is called the Eötvös effect in honor of the Hungarian physicist Lorand Åtvös, 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 momentum: in an inertial frame of reference, the value of momentum (equal to the product of momentum inertia times the angular velocity of rotation) does not change under the action of internal forces. If in some initial moment time the installation is motionless relative to the Earth, then the speed of its rotation relative to the inertial reference frame is equal to the angular velocity of the Earth's rotation. 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 Poinsot in 1851.

The first such experiment was carried out by Hagen in 1910: two weights on a smooth crossbar were installed motionless relative to the Earth's surface. Then the distance between the loads was reduced. As a result, the installation came into rotation. An even more illustrative experiment was made by the German scientist Hans Bucka in 1949. A rod about 1.5 meters long was installed perpendicular to a rectangular frame. Initially, the rod was horizontal, the installation was stationary 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 negligible effect on the direction of the swirl of water when draining in a sink or bathtub, so in general the direction of rotation in a funnel is not related to the rotation of the Earth. Only in carefully controlled experiments is it possible to separate the effect of the Coriolis force from other factors: in the northern hemisphere, the funnel will be twisted counterclockwise, in the southern hemisphere - vice versa.

Effects of the Coriolis Force: Phenomena in the Environment

Optical experiments

A number of experiments demonstrating the rotation of the Earth are based on the Sagnac effect: if the ring interferometer rotates, then due to relativistic effects, a phase difference appears in the oncoming beams

Δ φ = 8 π A λ c ω , (\displaystyle \Delta \varphi =(\frac (8\pi A)(\lambda c))\omega ,)

Where A (\displaystyle A)- the area of ​​the projection of the ring on the equatorial plane (the plane perpendicular to the axis of rotation), c (\displaystyle c)- speed of light, ω (\displaystyle \omega )- angular speed of rotation. To demonstrate the rotation of the Earth, this effect was used by the American physicist Michelson in a series of experiments carried out in 1923-1925. In modern experiments using the Sagnac effect, the rotation of the Earth must be taken into account to calibrate ring interferometers.

There are a number of other experimental demonstrations of the Earth's diurnal rotation.

Uneven rotation

Precession and nutation

History of the idea of ​​the daily rotation of the Earth

Antiquity

The explanation of the daily rotation of the sky by the rotation of the Earth around its axis was first proposed by the representatives of the Pythagorean school, the Syracusans Hicket and Ekfant. According to some reconstructions, the Pythagorean Philolaus of Croton (5th century BC) also claimed the rotation of the Earth. A statement that can be interpreted as an indication of the rotation of the Earth is contained in the Platonic dialogue Timaeus .

However, almost nothing is known about Giketa and Ekfant, and even their very existence is sometimes questioned. According to the opinion of most scientists, the Earth in the system of the world of Philolaus did not rotate, but forward movement around the Central Fire. In his other writings, Plato follows the traditional view of the immobility of the Earth. However, we have received numerous evidence that the idea of ​​the rotation of the Earth was defended by the philosopher Heraclides Pontic (4th century BC). Probably, another assumption of Heraclid is connected with the hypothesis of the rotation of the Earth around its axis: each star is a world that includes earth, air, ether, and all this is located in infinite space. Indeed, if the daily rotation of the sky is a reflection of the rotation of the Earth, then the premise of considering the stars as being on the same sphere disappears.

About a century later, the assumption of the rotation of the Earth became an integral part of the first, proposed by the great astronomer Aristarchus of Samos (3rd century BC). Aristarchus was supported by the Babylonian Seleucus (II century BC), as well as Heraclid Pontic, who considered the Universe to be infinite. The fact that the idea of ​​the daily rotation of the Earth had its supporters as early as the 1st century A.D. e., some statements of the philosophers Seneca, Derkillid, astronomer Claudius Ptolemy testify. The overwhelming majority of astronomers and philosophers, however, did not doubt the immobility of the Earth.

Arguments against the idea of ​​the Earth's motion are found in the works of Aristotle and Ptolemy. So, in his treatise About Heaven Aristotle justifies the immobility of the Earth by the fact that on a rotating Earth, bodies thrown vertically upwards could not fall to the point from which their movement began: the surface of the Earth would move under the thrown body. Another argument for 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 rotate around it.

It follows from the work of Ptolemy that the supporters of the hypothesis of the rotation of the Earth answered these arguments that both the air and all terrestrial objects move along with the Earth. Apparently, the role of air in this reasoning is fundamentally important, since it is understood that it is precisely its movement along with the Earth that hides the rotation of our planet. Ptolemy counters this by saying that

bodies in the air will always seem lagging behind ... And if the bodies rotated together with the air as a 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, such as we see with our own eyes taking place, and they would not slow down or accelerate at all, because the Earth is not stationary.

Middle Ages

India

The first of the medieval authors, who suggested that the Earth rotates around its axis, was the great Indian astronomer and mathematician Aryabhata (late V - early VI centuries). He formulates it in several places in his treatise. Ariabhatia, For example:

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 Aryabhata himself or whether he borrowed it from ancient Greek astronomers.

Aryabhata was supported by only one astronomer, Prthudaka (9th century). Most Indian scientists have defended the immobility of the Earth. Thus, 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 Earth's surface. The eminent astronomer Brahmagupta (6th century) also repeated the old argument that a body that fell from a high mountain could sink 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 break away from it due to their gravity.

Islamic East

The possibility of the Earth's rotation was considered by many scientists Muslim East. Thus, the famous geometer al-Sijizi invented the astrolabe, the principle of operation of which is based on this assumption. Some Islamic scholars (whose names have not come down to us) even found the right 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 stated, 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, which is the projection of this line onto the Earth’s surface, would be transferred to it. rotation. This is evidenced by the famous scientist-encyclopedist al-Biruni, who himself, however, was inclined 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 Maraga and Samarkand observatories, a discussion unfolded about the possibility of an empirical justification for the immobility of the Earth. Thus, the famous astronomer Kutb ad-Din ash-Shirazi (XIII-XIV centuries) believed that the immobility of the Earth could be verified by experiment. On the other hand, the founder of the Maraga Observatory, Nasir ad-Din at-Tusi, believed that if the Earth rotated, then 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 justified 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 entrained by the rotation of the sky, and therefore the lower layers can also be entrained 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 it was in line with the philosophy of Aristotle.

Most of the Islamic scholars of a later time (al-Urdi, al-Qazvini, an-Naysaburi, al-Dzhurjani, al-Birjandi and others) agreed with at-Tusi that all physical phenomena on a rotating and stationary Earth would result in the same way. However, the role of air in this case was no longer considered fundamental: not only air, but also all objects are transported by the rotating Earth. Therefore, to justify 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 (XV century), who rejected the philosophy of Aristotle and considered the rotation of the Earth physically possible. In the 17th century, the Iranian theologian and scholar-encyclopedist Baha al-Din al-Amili came to a similar conclusion. In his opinion, astronomers and philosophers have not provided sufficient evidence to disprove the rotation of the Earth.

latin west

A detailed discussion of the possibility of the Earth's motion is widely contained in the writings of the Parisian scholastics Jean Buridan, Albert of Saxony, and Nicholas Orem (second half of the 14th 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 attributing the daily rotation of the sky of the Universe to the highest degree unnatural.

However, all of these scientists ultimately rejected the rotation of the Earth, albeit on different grounds. Thus, Albert of Saxony believed that this hypothesis is not capable of explaining the observed astronomical phenomena. Buridan and Orem rightly disagreed with this, according to which celestial phenomena should occur in the same way regardless of what makes the rotation, the Earth or the Cosmos. Buridan could find only one significant argument against the rotation of the Earth: arrows fired vertically upwards fall down a sheer line, although with the rotation of the Earth, in his opinion, they would have to lag behind the movement of the Earth and fall to the west of the point of the shot.

But even this argument was rejected by Oresme. 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 which it was fired. Although here again the entraining role of air is mentioned, in reality it does not play a special role. This is illustrated by the following analogy:

Similarly, if the air were closed in a moving ship, then it would appear to a person surrounded by this air that the air is not moving ... If a person were in a ship moving at a high speed to the east, not knowing about this movement, and if he extended his arm in a straight line along the mast of the ship, it would have seemed to him that his arm was making a rectilinear movement; 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 at high speed eastward, all kinds of motion can take place: longitudinal, transverse, down, up, in all directions - and they seem exactly the same as when the ship is stationary.

Further, Orem gives a formulation that anticipates the principle of relativity:

I conclude, therefore, that it is impossible to demonstrate by any experience whatsoever that the heavens have a diurnal movement and that the earth does not.

However, Oresme'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, so far everyone supports and I believe that it is [Heaven] and not the Earth that moves, for "God created the circle of the Earth that will not shake", despite all the opposite arguments.

The possibility of a daily rotation of the Earth was also mentioned by medieval European scientists and philosophers of a later time, but no new arguments that were not contained in Buridan and Orem were added.

Thus, practically none of the medieval scientists accepted the hypothesis of the rotation of the Earth. However, in the course of its discussion by scientists of the East and West, many profound thoughts were expressed, which will then be repeated by scientists of the New Age.

Renaissance and Modern times

In the first half of the 16th century, several works were published that claimed that the reason for the daily rotation of the sky is 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 on the perpetual motion of the Earth" (written around 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 daily rotation of the Earth became part of the heliocentric system of the world, like Aristarchus Samossky . Copernicus previously expressed his thoughts in a small handwritten essay. Small Comment(not earlier than 1515). Two years earlier than the main work of Copernicus, the work of the German astronomer Georg Joachim Rhetik was published. First Narrative(1541), where the theory of Copernicus is popularly expounded.

In the 16th century, Copernicus was fully supported by the astronomers Thomas Digges, Retik, Christoph Rothman, Michael Möstlin, the physicists Giambatista Benedetti, Simon Stevin, the philosopher Giordano Bruno, the theologian Diego de Zuniga. Some scientists accepted the rotation of the Earth around its axis, rejecting its forward movement. This was the position of the German astronomer Nicholas Reimers, also known as Ursus, as well as the Italian philosophers Andrea Cesalpino and Francesco Patrici. Point of view not clear outstanding physicist William Gilbert, who supported the axial rotation of the Earth, but did not speak out about its translational motion. 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 ​​the Earth's motion in the 16th - early 17th centuries were the astronomers Tycho Brage and Christopher Clavius.

The hypothesis of the rotation of the Earth 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 attribute huge rotation speeds to the stellar sphere, 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 also contained by Buridan and Orem) .

Against this hypothesis, arguments based on the dynamic ideas of that time were expressed. First of all, this is the verticality of the trajectories of falling bodies. Other arguments also appeared, for example, equal firing range in the eastern and western 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 with it rotates, but also a considerable part of the air, and everything that is in any way akin to the Earth, or the air already closest to the Earth, saturated with terrestrial and water matter, follows the same laws of nature as The earth, or has acquired motion, which is communicated to it by the adjoining earth in constant rotation and without any resistance

Thus, leading role in the unobservability of the rotation of the Earth plays the entrainment of air by its rotation. This opinion was shared by the majority of Copernicans in the 16th century.

Supporters of the infinity of the Universe in the 16th century were also Thomas Digges, Giordano Bruno, Francesco Patrici - all of them supported the hypothesis of the rotation of the Earth around its axis (and the first two also around the Sun). Christoph Rothmann and Galileo Galilei believed the stars to be located at different distances from the Earth, although they did not explicitly 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 Debate

A number of objections to the rotation of the Earth were associated with its contradictions to the text. Holy Scripture. These objections were of two kinds. Firstly, some places in the Bible were cited to confirm that it is the Sun that makes the daily movement, 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 under attack, 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 has often been quoted in this connection:

Jesus called to the Lord on the day on which the Lord delivered the Amorites into the hands of Israel, when he struck them in Gibeon, and they were beaten before the face of the children of Israel, and said before the Israelites: Stop, the sun is over Gibeon, and the moon is 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 was the Sun that made the daily movement. Other passages have been cited in support of the Earth's immobility, such as:

You set the ground on solid foundations: it shall not be shaken forever and ever.

These passages were considered contrary to both the notion of the rotation of the Earth around its axis and the revolution around the Sun.

Supporters of the rotation of the Earth (in particular, Giordano Bruno, Johann Kepler and especially Galileo Galilei) defended in several directions. First, they pointed out that the Bible was written in a language understandable ordinary people, and if its authors had given clear formulations from a scientific point of view, it would not have been able to fulfill its main, religious mission. Thus, Bruno wrote:

In many cases it is foolish and inexpedient to give much reasoning according to the truth rather than according to 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 that sets, leans towards two tropics, from Cancer to the South, from Capricorn to Aquilo,” then the listeners would begin to think: “How? Does he say the earth is moving? What is this news? In the end, they would have considered him a fool, and he really would have been a fool.

Answers of this kind were given mainly to objections concerning the daily motion of the Sun. Secondly, it was noted that some passages of the Bible should be interpreted allegorically (see the article Biblical Allegorism). So, Galileo noted that if Holy Scripture is taken entirely literally, then it turns out that God has hands, he is subject to emotions such as anger, etc. In general, main idea The defenders of the doctrine of the movement of the Earth were that science and religion have different goals: science considers 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 quoted Cardinal Baronio in this connection that the Bible teaches how to ascend to heaven, not how the heavens are made.

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 of Italy, this ban did not have a significant impact on the development of science and mainly contributed to the fall of the authority of the Catholic Church itself.

It must 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 Brage). On the other hand, the Catholic monk Paolo Foscarini wrote short 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 Copernican theory to interpret certain passages of Holy Scripture (although he later changed his mind). Thus, the conflict between theology and the doctrine of the motion of the Earth was not so much a conflict between science and religion as such, but rather a conflict between the old (already obsolete by the beginning of the 17th century) and new methodological principles underlying science.

Significance of the hypothesis of the rotation of the Earth for the development of science

The understanding of the scientific problems raised by the theory of the rotating Earth contributed to the discovery of the laws classical mechanics and the creation of a new cosmology, which is based on the idea of ​​the 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.