Pupils 10 "k" GBOUSOSH 1908 Burmistrova Tatiana and Kozlova Maria
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HISTORY OF THE DEVELOPMENT OF ASTRONOMY
What is astronomy? Astronomy studies the structure of the universe, the physical nature, origin and evolution of celestial bodies and the systems they form. Astronomy also explores the fundamental properties of the universe around us. As a science, astronomy is based primarily on observations. Unlike physicists, astronomers are deprived of the opportunity to experiment. Almost all information about celestial bodies is brought to us by electromagnetic radiation. Only in the last 40 years have individual worlds been studied directly: by probing the atmospheres of planets, by studying the lunar and Martian soil. The scale of the observable Universe is huge and the usual units of measurement of distances - meters and kilometers - are of little use here. They are replaced by others.
The astronomical unit is used in the study of the solar system. This is the size of the semi-major axis of the Earth's orbit: 1 AU = 149 million km. Larger units of length - the light year and parsec, as well as their derivatives - are needed in stellar astronomy and cosmology. A light year is the distance traveled by a light beam in vacuum in one Earth year. The parsec is historically associated with measuring the distances to stars by their parallax and is 3.263 light years = 206,265 AU. e. Astronomy is closely connected with other sciences, primarily with physics and mathematics, the methods of which are widely used in it. But astronomy is also an indispensable testing ground on which many physical theories are tested. Space is the only place where matter exists at temperatures of hundreds of millions of degrees and near absolute zero, in the void of vacuum and in neutron stars. Recently, the achievements of astronomy have been used in geology and biology, geography and history.
Astronomy studies the fundamental laws of nature and the evolution of our world. Therefore, its philosophical significance is especially great. In fact, it determines the worldview of people. The oldest of sciences. Several thousand years before our era, landowners settled in the valleys of large rivers (Nile, Tigris and Euphrates, Indus and Ganges, Yangtze and Huang He). The calendar compiled by the priests of the Sun and the Moon began to play an important role in their lives. The priests carried out observations of the luminaries in ancient observatories, which were also temples at the same time. They are studied by archaeoastronomy. Archaeologists have found quite a few similar observatories.
The simplest of them - megaliths - consisted of one (menhirs) or several (dolmens, cromlechs) stones arranged in a strict order relative to each other. Megaliths marked the place of sunrise and sunset of the luminaries at a certain time of the year. One of the most famous buildings of antiquity is Stonehenge, located in southern England. Its main function is to observe the Sun and Moon, determine the days of the winter and summer solstices, predict lunar and solar eclipses.
Astronomy of ancient civilizations Approximately 4 thousand years BC. in the Nile Valley, one of the oldest civilizations on Earth, the Egyptian, arose. A thousand years later, after the unification of the two kingdoms (Upper and Lower Egypt), a powerful state was formed here. By that time, which is called the Old Kingdom, the Egyptians already knew the potter's wheel, knew how to smelt copper, and invented writing. It was during this era that the pyramids were built. At the same time, Egyptian calendars probably appeared: lunar-stellar - religious and schematic - civil. The astronomy of the Egyptian civilization began precisely with the Nile. Egyptian priest-astronomers noticed that shortly before the start of the rise of water, two events occur: the summer solstice and the first appearance of Sirius on the morning star after a 70-day absence from the sky. Sirius, the brightest star in the sky, was named by the Egyptians after the goddess Sopdet. The Greeks pronounced this name as "Sothis". By that time in Egypt there was a lunar calendar of 12 months of 29 or 30 days - from new moon to new moon. In order for its months to correspond to the seasons of the year, a 13th month had to be added every two or three years. "Sirius" helped to determine the time of insertion of this month. The first day of the lunar year was considered the first day of the new moon, which occurred after the return of this star.
Such an "observational" calendar with an irregular addition of a month was ill-suited for a state where strict accounting and order existed. Therefore, the so-called schematic calendar was introduced for administrative and civil needs. In it, the year was divided into 12 months of 30 days with the addition of an additional 5 days at the end of the year, i.e. contained 365 days. The Egyptians knew that the true year was a quarter of a day longer than the introduced one, and it was enough to add in every fourth, leap year, instead of five, an additional six days to harmonize it with the seasons. But this was not done. For 40 years, i.e. the life of one generation, the calendar went ahead by 10 days, not such a noticeable amount, and the scribes who managed the economy could easily adapt to the slow changes in the dates of the onset of the seasons. After some time, another lunar calendar appeared in Egypt, adapted to a sliding civil one. In it, additional months were inserted in such a way as to keep the beginning of the year not near the moment of the appearance of Sirius, near the beginning of the civil year. This "wandering" lunar calendar was used along with the other two.
Ancient Egypt had a complex mythology with many gods. The astronomical conceptions of the Egyptians were closely connected with it. According to their beliefs, in the middle of the world was Geb, one of the progenitors of the gods, the breadwinner and protector of people. He personified the Earth. Geb's wife and sister, Nut, was Heaven itself. She was called the Great Mother of the Stars and the Birth of the Gods. It was believed that every morning she swallows the luminaries and every evening gives birth to them again. Because of this habit of hers, Nut and Geb once had a quarrel. Then their father Shu, Air, raised the Sky above the Earth and separated the spouses. Nut was the mother of Ra (Sun) and the stars and ruled over them. Ra, in turn, created Thoth (Moon) as his deputy in the night sky. According to another myth, Ra floats on the celestial Nile and illuminates the Earth, and in the evening descends to the Duat (hell). There he travels along the underground Nile, fighting the forces of darkness, in order to reappear on the horizon in the morning.
Geocentric system of the world In the II century BC. Greek scientist Ptolemy put forward his "system of the world." He tried to explain the structure of the universe, taking into account the apparent complexity of the movement of the planets. Considering the Earth is spherical, and its dimensions are negligible in comparison with the distances to the planets, and even more so to the stars. Ptolemy, however, following Aristotle, argued that the Earth is the fixed center of the Universe, his system of the world was called geocentric. Around the Earth, according to Ptolemy, the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and stars move (in order of distance from the Earth). But if the motion of the Moon, Sun, stars is circular, then the motion of the planets is much more complicated.
Each of the planets, according to Ptolemy, does not move around the Earth, but around a certain point. This point, in turn, moves in a circle, in the center of which is the Earth. The circle described by the planet around the moving point, Ptolemy called the epicycle, and the circle along which the point moves around the Earth, the deferent. This false system has been recognized for nearly 1,500 years. It was also recognized by the Christian religion. Christianity based its worldview on the biblical legend of the creation of the world by God in 6 days. According to this legend, the Earth is the "concentration" of the Universe, and the heavenly bodies were created in order to illuminate the Earth and decorate the firmament. Any deviation from these views was mercilessly pursued by Christianity. The system of the world of Aristotle - Ptolemy, which placed the Earth at the center of the universe, perfectly corresponded to the Christian doctrine. The tables compiled by Ptolemy made it possible to determine in advance the position of the planets in the sky. But over time, astronomers have discovered a discrepancy between the observed positions of the planets and the predicted ones. For centuries, it was thought that the Ptolemaic system of the world was simply not perfect enough, and in an attempt to improve it, they introduced new and new combinations of circular motions for each planet.
The heliocentric system of the world The great Polish astronomer Nicolaus Copernicus (1473-1543) outlined his system of the world in the book "On the rotations of the celestial spheres", published in the year of his death. In this book, he proved that the universe is not arranged in the way that religion has claimed for many centuries. Long before Ptolemy, the Greek scientist Aristarchus argued that the Earth moves around the Sun. Later, in the Middle Ages, advanced scientists shared the point of view of Aristarchus on the structure of the world and rejected the false teachings of Ptolemy. Shortly before Copernicus, the great Italian scientists Nicholas of Cusa and Leonardo da Vinci argued that the Earth moves, that it is not at all in the center of the Universe and does not occupy an exceptional position in it. Why, in spite of this, did the Ptolemaic system continue to dominate? Because it relied on the all-powerful church authority, which suppressed free thought, hindered the development of science. In addition, scientists who rejected the teachings of Ptolemy and expressed correct views on the structure of the Universe could not yet convincingly substantiate them. This was done only by Nicolaus Copernicus. After 30 years of hard work, much thought and complex
Mathematical calculations, he showed that the Earth is only one of the planets, and all the planets revolve around the Sun. What does the book "On the rotation of the heavenly spheres" contain and why did it deal such a crushing blow to the Ptolemaic system, which, with all its flaws, had been kept for 14 centuries under the auspices of the all-powerful church? In this book, Nicolaus Copernicus argued that the Earth and other planets are satellites of the Sun. He showed that it is the movement of the Earth around the Sun and its daily rotation around its axis that explains the apparent movement of the Sun, the strange entanglement in the movement of the planets, and the apparent rotation of the firmament. Brilliantly simple, Copernicus explained that we perceive the movement of distant celestial bodies in the same way as the movement of various objects on Earth when we ourselves are in motion. Copernicus, like the ancient Greek scientists, suggested that the orbits along which the planets move can only be circular. After 75 years, the German astronomer Johannes Kepler, the successor of Copernicus, proved that if the Earth moved in space, then when observing the sky at different times, it would seem to us that the stars are shifting, changing their position in the sky. But no astronomer has noticed such displacements of stars for many centuries. It was in this that the supporters of the teachings of Ptolemy wanted to see evidence of the immobility of the Earth. However, Copernicus argued that the stars are at unimaginably great distances. Therefore, their insignificant shifts could not be noticed.
Classics of Celestial Mechanics The century after Newton's death (1727) was a time of rapid development of celestial mechanics, a science based on the theory of gravity. And it just so happened that the main contribution to the development of this science was made by five remarkable scientists. One of them is from Switzerland, although he worked most of his life in Russia and Germany. This is Leonardo Euler. The other four are French (Clero, D'Alembert, Lagrange and Laplace). In 1743, d'Alembert published his "Treatise on Dynamics", which formulated the general rules for compiling differential equations describing the motion of material bodies and their systems. In 1747, he submitted to the Academy of Sciences memoirs on the deviations of the planets from elliptical motion around the Sun under the influence of their mutual attraction. Alexis Claude Clairaut (1713-1765) did his first scientific work on geometry already at the age of less than 13. It was presented to the Paris Academy, where it was read by his father. Three years later, Clairaut published a new work - "On curves of double curvature." Youthful work attracted the attention of prominent mathematicians. They began to seek the election of a young talent to the Paris Academy of Sciences. But according to the charter, only a person who had reached the age of 20 could become a member of the Academy.
Then the famous mathematician Pierre Louis Maupertuis (1698-1759), the patron of Alexis, decided to take him to Basel to Johann Bernoulli. For three years, Clairaut listened to the lectures of a venerable scientist, improving his knowledge. Upon his return to Paris, having already reached the age of 20, he was elected to the adjunct of the Academy (junior rank of academicians). In Paris, Clairaut and Maupertuis plunged into the midst of a debate about the shape of the Earth: is it compressed at the poles or elongated? Maupertuis began to prepare an expedition to Lapland to measure the arc of the meridian. Clairaut also took part in it. Returning from Lapland, Clairaut received the title of full member of the Academy of Sciences. His life was now secure and he was able to devote it to scientific pursuits. Joseph Louis Lagrange (1735-1813) studied and then taught at the Artillery School in Turin, becoming a professor at the age of 18. In 1759, on the recommendation of Euler, the 23-year-old Lagrange was elected a member of the Berlin Academy of Sciences. In 1766, he already became its president. The range of Lagrange's scientific research was extraordinarily wide. They are devoted to mechanics, geometry, mathematical analysis, algebra, number theory, as well as theoretical astronomy. The main direction of Lagrange's research was the presentation of the most diverse phenomena in mechanics from a single point of view. He derived an equation describing the behavior of any systems under the action of forces. In the field of astronomy, Lagrange did much to solve the problem of the stability of the solar system; proved some particular cases of stable motion, in particular for small bodies located at the so-called triangular libration points. These bodies are asteroids
"Trojans" - were discovered already in the 20th century, a century after the death of Lagrange. In solving specific problems of celestial mechanics, the paths of these scientists repeatedly crossed; they voluntarily or involuntarily competed with each other, coming either to close, or to completely different results. Modern Astronomy The whole history of the study of the Universe is, in essence, the search for means that improve human vision. Until the beginning of the 17th century, the naked eye was the only optical instrument of astronomers. The whole astronomical technique of the ancients was reduced to the creation of various goniometric instruments, as accurate and durable as possible. Already the first telescopes immediately sharply increased the resolving and penetrating power of the human eye. The universe turned out to be completely different than it had seemed until then. Gradually, receivers of invisible radiation were created, and at present we perceive the universe in all ranges of the electromagnetic spectrum - from gamma rays to ultra-long radio waves. Moreover, corpuscular radiation receivers have been created that capture the smallest particles - corpuscles (mainly atomic nuclei and electrons) that come to us from celestial bodies. If you are not afraid of allegories, we can say that the Earth has become sharper, its "eyes", that is, the totality of all cosmic radiation receivers, are capable of
to fix objects from which rays of light reach us for many billions of years. Thanks to telescopes and other instruments of astronomical technology, over three and a half centuries, man has penetrated such cosmic distances, where light - the fastest thing in this world - can only reach in billions of years! This means that the radius of the universe studied by mankind is growing at a speed that is many times greater than the speed of light! Spectral analysis - the study of the intensity of radiation in individual spectral lines, in individual parts of the spectrum. Spectral analysis is a method by which the chemical composition of celestial bodies, their temperature, size, structure, distance to them and the speed of their movement are determined. In 50 years, presumably, planets near the nearest 5-10 stars will be discovered (if any). Most likely they will be detected in the optical, infrared and submillimeter wave ranges from extra-atmospheric installations. In the future, interstellar probe ships will appear to fly to one of the nearest stars within 5-10 light years, of course, to the one near which the planets will be discovered. Such a ship will move at a speed of no more than 0.1 of the speed of light with the help of a thermonuclear engine.
2000 years ago, the distance of the Earth from the Sun, according to Aristarchus of Samos, was about 361 Earth radii, i.e. about 2.300.000 km. Aristotle believed that the "sphere of stars" is located 9 times further. Thus, the geometric scales of the world 2000 years ago were "measured" by a value of 20,000,000 km. With the help of modern telescopes, astronomers observe objects located at a distance of about 10 billion light years. Thus, over the mentioned period of time, the scale of the world has grown by 5,000,000,000,000,000 times. According to Byzantine Christian theologies, the world was created 5508 BC, i.e. less than 7.5 thousand years ago. Modern astronomy has provided evidence that already about 10 billion years ago the Universe available for astronomical observations existed in the form of a giant system of galaxies. Scales in time "grew" in 13 million times. But the main thing, of course, is not in the digital growth of spatial and temporal scales, although they are breathtaking. The main thing is that man has finally reached the broad path of understanding the real laws of the universe.
END Thank you for your attention!
slide 1
History of astronomy
slide 2
Stonehenge - Bronze Age Observatory
In plan, Stonehenge is a series of almost exact circles with a common center, along which huge stones are placed at regular intervals. The outer row of stones has a diameter of about 100 meters. Their location is symmetrical to the direction to the sunrise point on the day of the summer solstice, and some directions correspond to the directions to the sunrise and sunset points on the equinoxes and on some other days. Undoubtedly, Stonehenge also served for astronomical observations.
slide 3
The earth seemed to them flat, and the sky - a huge dome, spread over the Earth. The picture shows how the firmament rests on four high mountains located somewhere at the end of the world! Egypt is in the center of the earth. The celestial bodies seem to be suspended on a dome.
Ideas about the world of the ancient Egyptians
slide 4
Ideas about the world of the peoples of Mesopotamia
The Chaldeans are the people who inhabited Mesopotamia, starting from the 7th century BC. believed that the Universe was a closed world, in the center of which was the Earth, resting on the surface of the world's waters and representing a huge mountain. The sea was considered forbidden. Everyone who would try to explore it gave, was doomed to death. The Chaldeans considered the sky to be a large dome, towering over the world and resting on the "dam of heaven." It is made of solid metal by the supreme boron Marduk.
slide 5
The universe according to the ancient Greeks
He considered the earth to be a flat disk, surrounded by a sea inaccessible to man, from which stars come and go every evening. From the eastern sea in a golden chariot, the sun god Helios rose every morning and made his way across the sky.
slide 6
Claudius Ptolemy The famous ancient Greek astronomer and astrologer, mathematician and geographer of the 2nd century AD. e.
Slide 7
Geocentric system of the world - (the idea of \u200b\u200bthe structure of the universe, according to which the central position in the Universe is occupied by the motionless Earth, around which the Sun, Moon, planets and stars revolve
Slide 8
Astronomical representations in India
A flat earth with a huge mountain in the center is supported by 4 elephants who are standing on a huge turtle floating in the ocean.
Slide 9
Observatories of the ancient Maya
The painting depicts a Mayan observatory (circa 900). In form, this structure reminds us of modern observatories, but the Mayan stone dome did not rotate around its axis and they did not have telescopes. Observations of celestial bodies were made with the naked eye using goniometers.
Slide 10
Ideas about the world in the Middle Ages
In the Middle Ages, under the influence of the Catholic Church, there was a return to the primitive ideas of antiquity about a flat Earth and the hemispheres of the sky based on it.
slide 11
Nicolaus Copernicus 02/19/1473 - 05/24/1543
Polish astronomer, mathematician and economist
slide 12
World system according to Copernicus
slide 13
1. The center of the Earth is not the center of the universe, but only the center of mass and orbit of the Moon. 2. All planets move in orbits, the center of which is the Sun, and therefore the Sun is the center of the world. 3. The distance between the Earth and the Sun is very small compared to the distance between the Earth and the fixed stars. 4. The Earth (together with the Moon, like other planets), revolves around the Sun, and therefore the movements that the Sun seems to make (the daily movement, as well as the annual movement when the Sun moves around the Zodiac) are nothing more than an effect the movements of the earth.
Slide 14
Giordano Bruno 1548– 02/17/1600 Italian philosopher and poet, representative of pantheism
slide 15
Developing the heliocentric theory of Copernicus, Bruno expressed ideas about the infinity of nature and an infinite number of worlds of the Universe, asserted the physical homogeneity of the world (the doctrine of the 5 elements that make up all bodies - earth, water, fire, air and ether).
“Ignorance is the best science in the world, it is given without difficulty and does not sadden the soul!” (Giordano Bruno).
slide 16
Galileo Galilei 02/15/1564 - 01/08/1642
Italian philosopher, mathematician, physicist, mechanic and astronomer
Slide 17
1. In 1609, Galileo independently built his first telescope with a convex lens and a concave eyepiece.
2. On January 7, 1610, Galileo was the first to point his telescope at the sky. Telescope observations have shown that the Moon is covered with mountains and craters and is thus a body similar to the Earth.
Slide 18
4. Galileo discovered mountains on the Moon, the Milky Way broke up into separate stars, but the 4 satellites of Jupiter he discovered were especially struck by his contemporaries
Slide 19
Galilean moons of Jupiter (modern photos)
Slide 20
Galileo invented: hydrostatic balance to determine the specific gravity of solids. proportional compass used in drawing. the first thermometer, still without a scale. improved compass for use in artillery. microscope, poor quality (1612); with it, Galileo studied insects. He also studied optics, acoustics, the theory of color and magnetism, hydrostatics, and the strength of materials. Determine the specific gravity of air. He conducted an experiment to measure the speed of light, which he considered finite (without success)
slide 21
There is a well-known legend according to which, after the trial, Galileo said, “And yet it spins!”
Galileo before the court of the Inquisition
slide 22
Tomb of Galileo Galilei. Cathedral of Santa Croce, Florence.
What is astronomy? Astronomy (from the Greek στρο "star" and νόμος "law") is the science of the Universe that studies the location, movement, structure, origin and development of celestial bodies and systems. Astronomy studies the structure of the universe, the physical nature, origin and evolution of celestial bodies and the systems they form. Astronomy also explores the fundamental properties of the universe around us. As a science, astronomy is based primarily on observations. Unlike physicists, astronomers are deprived of the opportunity to experiment. Almost all information about celestial bodies is brought to us by electromagnetic radiation. Only in the last 40 years have individual worlds been studied directly: by probing the atmospheres of planets, by studying the lunar and Martian soil. The scale of the observable Universe is huge and the usual units of measurement of distances - meters and kilometers - are of little use here. They are replaced by others.
The astronomical unit is used in the study of the solar system. This is the size of the semi-major axis of the Earth's orbit: 1 AU = 149 million km. Larger units of length - the light year and parsec, as well as their derivatives - are needed in stellar astronomy and cosmology. A light year is the distance traveled by a light beam in vacuum in one Earth year. The parsec is historically associated with the measurement of distances to stars by their parallax and is 3.263 light years = a. e. Astronomy is closely connected with other sciences, primarily with physics and mathematics, the methods of which are widely used in it. But astronomy is also an indispensable testing ground on which many physical theories are tested. Space is the only place where matter exists at temperatures of hundreds of millions of degrees and near absolute zero, in the void of vacuum and in neutron stars. Recently, the achievements of astronomy have been used in geology and biology, geography and history.
Astronomy studies the fundamental laws of nature and the evolution of our world. Therefore, its philosophical significance is especially great. In fact, it determines the worldview of people. The oldest of sciences. Several thousand years before our era, landowners settled in the valleys of large rivers (Nile, Tigris and Euphrates, Indus and Ganges, Yangtze and Huang He). The calendar compiled by the priests of the Sun and the Moon began to play an important role in their lives. The priests carried out observations of the luminaries in ancient observatories, which were also temples at the same time. They are studied by archaeoastronomy. Archaeologists have found quite a few similar observatories.
The simplest of them - megaliths - consisted of one (menhirs) or several (dolmens, cromlechs) stones arranged in a strict order relative to each other. Megaliths marked the place of sunrise and sunset of the luminaries at a certain time of the year. One of the most famous buildings of antiquity is Stonehenge, located in southern England. Its main function is to observe the Sun and Moon, determine the days of the winter and summer solstices, predict lunar and solar eclipses.
Astronomy of ancient civilizations Approximately 4 thousand years BC. in the Nile Valley, one of the oldest civilizations on Earth, the Egyptian, arose. A thousand years later, after the unification of the two kingdoms (Upper and Lower Egypt), a powerful state was formed here. By that time, which is called the Old Kingdom, the Egyptians already knew the potter's wheel, knew how to smelt copper, and invented writing. It was during this era that the pyramids were built. At the same time, Egyptian calendars probably appeared: lunar-stellar - religious and schematic - civil. The astronomy of the Egyptian civilization began precisely with the Nile. Egyptian priest-astronomers noticed that shortly before the start of the rise of water, two events occur: the summer solstice and the first appearance of Sirius on the morning star after a 70-day absence from the sky. Sirius, the brightest star in the sky, was named by the Egyptians after the goddess Sopdet. The Greeks pronounced this name as "Sothis". By that time in Egypt there was a lunar calendar of 12 months of 29 or 30 days - from new moon to new moon. In order for its months to correspond to the seasons of the year, a 13th month had to be added every two or three years. "Sirius" helped to determine the time of insertion of this month. The first day of the lunar year was considered the first day of the new moon, which occurred after the return of this star.
Such an "observational" calendar with an irregular addition of a month was ill-suited for a state where strict accounting and order existed. Therefore, the so-called schematic calendar was introduced for administrative and civil needs. In it, the year was divided into 12 months of 30 days with the addition of an additional 5 days at the end of the year, i.e. contained 365 days. The Egyptians knew that the true year was a quarter of a day longer than the introduced one, and it was enough to add in every fourth, leap year, instead of five, an additional six days to harmonize it with the seasons. But this was not done. For 40 years, i.e. the life of one generation, the calendar went ahead by 10 days, not such a noticeable amount, and the scribes who managed the economy could easily adapt to the slow changes in the dates of the onset of the seasons. After some time, another lunar calendar appeared in Egypt, adapted to a sliding civil one. In it, additional months were inserted in such a way as to keep the beginning of the year not near the moment of the appearance of Sirius, but near the beginning of the civil year. This "wandering" lunar calendar was used along with the other two.
Ancient Egypt had a complex mythology with many gods. The astronomical conceptions of the Egyptians were closely connected with it. According to their beliefs, in the middle of the world was Geb, one of the progenitors of the gods, the breadwinner and protector of people. He personified the Earth. Geb's wife and sister, Nut, was Heaven itself. She was called the Great Mother of the Stars and the Birth of the Gods. It was believed that every morning she swallows the luminaries and every evening gives birth to them again. Because of this habit of hers, Nut and Geb once had a quarrel. Then their father Shu, Air, raised the Sky above the Earth and separated the spouses. Nut was the mother of Ra (Sun) and the stars and ruled over them. Ra, in turn, created Thoth (Moon) as his deputy in the night sky. According to another myth, Ra floats on the celestial Nile and illuminates the Earth, and in the evening descends to the Duat (hell). There he travels along the underground Nile, fighting the forces of darkness, in order to reappear on the horizon in the morning.
In our time, historical science believes that the beginning of the Ancient Chinese civilization coincides in time with the accession of the First Dynasty of the Early Kingdom of Ancient Egypt, that is, it actually dates back to the end of the 4th millennium BC. You can trace the development of astronomy in China since ancient times. In general, the interest of the inhabitants of this country in the study of everything in the world is a feature of the national character. This also applies to astronomy. So, archaeologists have found painted pottery, which is years old. It contains lunar and solar symbols, as well as ornaments associated with the lunar calendar. On fortune-telling bones and tortoise shells of the Shang-Yin era (second half of the 2nd millennium BC), there are names of some constellations and calendar signs. Some solar eclipses are also mentioned. The practice of keeping records of celestial phenomena did not stop in all periods of the history of Ancient China. The number of accumulated handwritten documents of astronomical content is the largest in comparison with those available in any other civilization.
Like almost all primitive peoples, the Chinese have used the lunar calendar since time immemorial, that is, a way of counting days by the phases of the moon. Since a month of 2930 days was considered long as a measure of time intervals of ancient life, it was quite natural to divide it into 34 parts. In China, as in other agrarian civilizations of the ancient world, the formation of the lunar calendar was most closely connected with the economic needs of the agricultural population. The Chinese character for time (shi), which is already found in ancient texts, graphically expresses the idea of seeds growing under the sun in the earth. And later, the concept of time in China never lost touch with the idea of a qualitative stage-by-stage, natural duration inherent in the life process. Even in ancient China, the phases of the moon were chosen as the main unit of time. In the Chinese lunar calendar, the beginning of the month coincides with the new moon, and the middle with the full moon. The quarter phases of the moon are also distinguished as cardinal points of the lunar month, which have their own characteristics. Twelve lunar months form a year. It is by the lunar months that almost all traditional holidays in China and neighboring countries are still oriented.
The practice of keeping records of celestial phenomena did not stop in all periods of the history of Ancient China. The number of accumulated handwritten documents of astronomical content is the largest in comparison with those available in any other civilization. Approximately in the III millennium BC. e. Chinese astronomers divided the sky into 28 constellation sections, in which the Sun, Moon and planets moved. Then they singled out the Milky Way, calling it a phenomenon of unknown nature. The founder of the Zhou Dynasty Wu-wang (ruled, according to some sources, in the years BC) ordered the erection of an astronomical tower in Gaochengzheng. It was the first observatory in China. Starting from the Chunqiu era (BC), the Chinese recorded the appearance of comets in writing, which were called “broom stars” in China and were considered harbingers of misfortune from time immemorial. Later, their detailed descriptions and sketches appeared. It was noticed that the tail of a comet is always at a distance from the Sun. In the chronicle called "Chunqiu" of the same period, 37 solar eclipses were recorded, observed over a period of 242 years. Modern scientists have confirmed 33 of them. The earliest occurred on February 22, 720 BC. e.
Astronomical observations for the inhabitants of ancient Mesopotamia (Babylon) were not unusual. Near the equator, it is difficult to build a solar calendar, and observations of the moon are much easier, so the Babylonians used the phases of the moon to build a calendar, although they were forced to reduce it to the solar one, for its use in agriculture and for religious purposes. The calendar of the ancient Sumerians consisted of 12 months of 29 and 30 days and contained 354 or 355 days. At the same time, a seven-day week was introduced, each day of which was dedicated to one of the luminaries (Mercury, Venus, Mars, Jupiter, Saturn, the Moon and the Sun). In Babylon, careful observations were made of the movement of the sun and moon. Their position was plotted on a map divided into 12 sectors (later called the zodiac). Stars were cataloged, solar and lunar eclipses were recorded, observations were made of the planets, and the motion of Venus was especially carefully studied. A detailed diagram of the movement of the Sun and Moon was drawn up, which served as the basis for an accurate calendar, and made it possible to predict eclipses. A similar scheme was used to determine the positions of the planets. An important role was played by astrology, which studied the influence of heavenly bodies on earthly affairs. The ancient Babylonians knew the saros - a period of time (about 18 years) through which the Sun, Moon and Earth return to the same relative position.
Due to the common features of the ancient Indian civilization with the ancient cultures of Babylon and Egypt and the presence of contacts between them, although not regular, it can be assumed that a number of astronomical phenomena known in Babylon and Egypt were also known in India. Apparently, our information about the science of the most ancient Indians will expand significantly as a result of deciphering the existing inscriptions. e. Although these writings are not specifically devoted to the exact sciences, one can find in them a lot of evidence regarding astronomy. It contains, in particular, information about solar eclipses, intercalations with the help of the thirteenth month, a list of nakshatras of lunar stations; finally, the cosmogonic hymns dedicated to the goddess of the Earth, the glorification of the Sun, the personification of time as the primordial power, also have a certain relation to astronomy.
The ancient Greeks represented the Earth as a flat or convex disk surrounded by an ocean, although Plato and Aristotle already spoke of the sphericity of the Earth. Aristotle observed the Moon and noticed that at certain phases it looks like a ball, illuminated from one side by the Sun. So the moon is spherical. Further, he concluded that the shadow that covers the Moon during eclipses can only belong to the Earth, and since the shadow is round, then the Earth must be round. Aristotle pointed to another fact that proves the sphericity of the Earth: the fact that the constellations change position when moving north or south. After all, if the Earth were flat, then the stars would remain in place. The idea that the Earth revolves around the Sun was expressed by Aristarchus of Samos. He tried to calculate the distance between the Earth, the Sun and the Moon, as well as the ratio of their sizes. Aristarchus calculated that the Sun is 19 times farther from the Earth than the Moon (according to modern data, 400 times farther), and the volume of the Sun is 300 times the volume of the Earth. Then he wondered how the huge Sun could revolve around the small Earth, and concluded that it was the Earth that revolved around the Sun. Aristarchus also explained why there is a change of day and night: the Earth simply rotates not only around the Sun, but around its own axis.
The ancient Greeks represented the Earth as a flat or convex disk surrounded by an ocean, although Plato and Aristotle already spoke of the sphericity of the Earth. Aristotle observed the Moon and noticed that at certain phases it looks like a ball, illuminated from one side by the Sun. So the moon is spherical. Further, he concluded that the shadow that covers the Moon during eclipses can only belong to the Earth, and since the shadow is round, then the Earth must be round. Aristotle pointed to another fact that proves the sphericity of the Earth: the fact that the constellations change position when moving north or south. After all, if the Earth were flat, then the stars would remain in place. The idea that the Earth revolves around the Sun was expressed by Aristarchus of Samos. He tried to calculate the distance between the Earth, the Sun and the Moon, as well as the ratio of their sizes. Aristarchus calculated that the Sun is 19 times farther from the Earth than the Moon (according to modern data, 400 times farther), and the volume of the Sun is 300 times the volume of the Earth. Then he wondered how the huge Sun could revolve around the small Earth, and concluded that it was the Earth that revolves around the Sun. Aristarchus also explained why there is a change of day and night: the Earth simply rotates not only around the Sun, but around its own axis. The Greeks used the lunisolar calendar. The years in it consisted of 12 lunar months of 29 and 30 days in total, there were 354 days in a year with an insert, approximately once every 3 years, of an additional month. As the calendar was streamlined, an 8-year cycle (octaetherides) was introduced, in which the month was inserted in the 3rd, 5th and 8th year (in Athens, its introduction is attributed to Solon in 594 BC); in 432 BC. e. the astronomer Meton suggested a more accurate 19-year cycle with 7 intercalary months, but this cycle came into use slowly and so to the end and did not take root in the Olympiad in the calendar sense 4-year intervals between Greek sports held at Olympia. They were used in the ancient Greek chronology. The Olympic Games were held on the days of the first full moon after the summer solstice, in the month of hecatombeion, which corresponds to modern July. According to calculations, the first Olympic Games took place on July 17, 776 BC. e. At that time, a lunar calendar was used with additional months of the Metonic cycle.
Geocentric system of the world In the II century BC. Greek scientist Ptolemy put forward his "system of the world." He tried to explain the structure of the universe, taking into account the apparent complexity of the movement of the planets. Considering the Earth is spherical, and its dimensions are negligible compared to the distances to the planets, and even more so to the stars. Ptolemy, however, following Aristotle, argued that the Earth is the fixed center of the Universe, his system of the world was called geocentric. Around the Earth, according to Ptolemy, the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and stars move (in order of distance from the Earth). But if the motion of the Moon, Sun, stars is circular, then the motion of the planets is much more complicated.
Each of the planets, according to Ptolemy, does not move around the Earth, but around a certain point. This point, in turn, moves in a circle, in the center of which is the Earth. The circle described by the planet around the moving point, Ptolemy called the epicycle, and the circle along which the point moves around the Earth, the deferent. This false system has been recognized for almost years. It was also recognized by the Christian religion. Christianity based its worldview on the biblical legend of the creation of the world by God in 6 days. According to this legend, the Earth is the "concentration" of the Universe, and the heavenly bodies were created in order to illuminate the Earth and decorate the firmament. Any deviation from these views was mercilessly pursued by Christianity. The system of the world of Aristotle - Ptolemy, which placed the Earth at the center of the universe, perfectly corresponded to the Christian doctrine. The tables compiled by Ptolemy made it possible to determine in advance the position of the planets in the sky. But over time, astronomers have discovered a discrepancy between the observed positions of the planets and the predicted ones. For centuries, it was thought that the Ptolemaic system of the world was simply not perfect enough, and in an attempt to improve it, they introduced new and new combinations of circular motions for each planet.
The Julian calendar ("old style") is the calendar adopted in Europe and Russia before the transition to the Gregorian calendar. Introduced in the Roman Republic by Julius Caesar on January 1, 45 BC, or 708 from the founding of Rome. Since there are not exactly 365 days in a year, but several more, the idea was to establish a leap year: the duration of every fourth year was set at 366 days. Caesar went on to establish a year of 365 days, starting on January 1, to limit the power of the pontiff - the high priest, who set the length of the year arbitrarily, lengthening and shortening different years for personal purposes. The Julian calendar was the official calendar in Europe until 1582 AD. e., when it was introduced by Pope Gregory XIII into the Catholic Gregorian calendar. The Orthodox Church (Eastern Rite Christians) still uses the Julian calendar.
There was no people in all of Mesoamerica who achieved more significant success in the sciences than did the Maya, a people of extraordinary abilities. A high level of civilization was determined primarily by astronomy and mathematics. In this area, they really found themselves in pre-Columbian America without any competition. Their achievements are incomparable to any others. The Maya surpassed even their European contemporaries in these sciences. Currently, at least 18 observatories are known to exist. The priests, who made up the highest stratum of society, kept great-great-grandfather's astronomical knowledge about the movement of the stars, the Sun, the Moon, Venus and Mars. Based on centuries of observations, they calculated the length of the solar year with an accuracy that surpasses the Gregorian calendar that we currently use. According to their calculations, the length of this year was equal to days; according to the Gregorian calendar, it is days, and according to modern astronomical data, days. They knew how to calculate the onset of solar eclipses, came close to understanding the 19-year Metonic cycle. In 682, the priest-astronomers of Copan introduced a formula according to which 149 lunar months equaled 4400 days. Soon this formula was adopted in almost all cities of the classical period. According to it, the length of the lunar month was equal to days on average - a figure very close to the data of our astronomers (days).
There was no people in all of Mesoamerica who achieved more significant success in the sciences than did the Maya, a people of extraordinary abilities. A high level of civilization was determined primarily by astronomy and mathematics. In this area, they really found themselves in pre-Columbian America without any competition. Their achievements are incomparable to any others. The Maya surpassed even their European contemporaries in these sciences. Currently, at least 18 observatories are known to exist. The priests, who made up the highest stratum of society, kept great-great-grandfather's astronomical knowledge about the movement of the stars, the Sun, the Moon, Venus and Mars. Based on centuries of observations, they calculated the length of the solar year with an accuracy that surpasses the Gregorian calendar that we currently use. According to their calculations, the length of this year was equal to days; according to the Gregorian calendar, it is days, and according to modern astronomical data, days. They knew how to calculate the onset of solar eclipses, came close to understanding the 19-year Metonic cycle. In 682, the priest-astronomers of Copan introduced a formula according to which 149 lunar months equaled 4400 days. Soon this formula was adopted in almost all cities of the classical period. According to it, the length of the lunar month was equal to days on average - a figure very close to the data of our astronomers (days). The cycle of the planet Venus with an average length of days was used as a calendar; on the sheets of the Dresden manuscript, a wonderful calendar of Venus is set out, correct for a total of 384 years. Maya were known and Other planets: Mars, Saturn, Mercury, Jupiter. However, here, as in other astronomical issues, the opinions of researchers differ so much from each other that only one thing becomes clear: the work has only just begun. Astronomical observations were made by the Maya from the tops of their pyramidal temples with the naked eye; the only instrument perhaps was two crossed sticks to fix the vantage point. At least, such tools are depicted in the manuscripts of Nuttol, Selden and Bodley near the priests watching the stars. In addition, there were special architectural complexes designed to determine the turning points of the seasons.
There was no people in all of Mesoamerica who achieved more significant success in the sciences than did the Maya, a people of extraordinary abilities. A high level of civilization was determined primarily by astronomy and mathematics. In this area, they really found themselves in pre-Columbian America without any competition. Their achievements are incomparable to any others. The Maya surpassed even their European contemporaries in these sciences. Currently, at least 18 observatories are known to exist. The priests, who made up the highest stratum of society, kept great-great-grandfather's astronomical knowledge about the movement of the stars, the Sun, the Moon, Venus and Mars. Based on centuries of observations, they calculated the length of the solar year with an accuracy that surpasses the Gregorian calendar that we currently use. According to their calculations, the length of this year was equal to days; according to the Gregorian calendar, it is days, and according to modern astronomical data, days. They knew how to calculate the onset of solar eclipses, came close to understanding the 19-year Metonic cycle. In 682, the priest-astronomers of Copan introduced a formula according to which 149 lunar months equaled 4400 days. Soon this formula was adopted in almost all cities of the classical period. According to it, the length of the lunar month was equal to days on average - a figure very close to the data of our astronomers (days). Hundreds of years ago in ancient Russia, the world system created in the 6th century by the Byzantine monk Kozma Indikoplov was especially popular. He assumed that the Earth, the main part of the universe, having the shape of a rectangle, is washed by the ocean, and on its four sides there are sheer walls, on which the crystal sky rests. According to the teachings of Cosmas, all heavenly bodies are set in motion by angels and created to illuminate and heat the Earth. In ancient Kievan Rus, they did not learn how to predict astronomical phenomena, such as a solar eclipse or the appearance of comets, but ancient Russian chronicles provide detailed descriptions of these events. In particular, in the annals of Kievan Rus, as a relatively northern state, the northern lights are described in some detail, which allowed modern astronomers to be convinced of the constancy of the solar cycle.
There was no people in all of Mesoamerica who achieved more significant success in the sciences than did the Maya, a people of extraordinary abilities. A high level of civilization was determined primarily by astronomy and mathematics. In this area, they really found themselves in pre-Columbian America without any competition. Their achievements are incomparable to any others. The Maya surpassed even their European contemporaries in these sciences. Currently, at least 18 observatories are known to exist. The priests, who made up the highest stratum of society, kept great-great-grandfather's astronomical knowledge about the movement of the stars, the Sun, the Moon, Venus and Mars. Based on centuries of observations, they calculated the length of the solar year with an accuracy that surpasses the Gregorian calendar that we currently use. According to their calculations, the length of this year was equal to days; according to the Gregorian calendar, it is days, and according to modern astronomical data, days. They knew how to calculate the onset of solar eclipses, came close to understanding the 19-year Metonic cycle. In 682, the priest-astronomers of Copan introduced a formula according to which 149 lunar months equaled 4400 days. Soon this formula was adopted in almost all cities of the classical period. According to it, the length of the lunar month was equal to days on average - a figure very close to the data of our astronomers (days). The history of the development of astronomy in ancient Spain is associated first with Carthage (New Carthage, Cartagena), which was founded around 227 BC. e. Since the Carthaginian civilization was in many ways the bearer of ancient Greek culture, astronomical knowledge in understanding the structure of the world of this civilization differed little from ancient Greek. With the establishment of Roman rule in Spain in 218 BC. e. - 17 AD e. Roman law is introduced in Spain, including the Julian calendar.
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Astronomy is the most ancient among the natural sciences. It was highly developed by the Babylonians and Greeks - much more than physics, chemistry and technology. In antiquity and the Middle Ages, not only purely scientific curiosity prompted calculations, copying, corrections of astronomical tables, but above all the fact that they were necessary for astrology.
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In ancient China for 2 thousand years BC. the apparent movements of the sun and moon were so well understood that Chinese astronomers could predict the onset of solar and lunar eclipses.
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The system of the world of Ptolemy completes the stage of development of ancient Greek astronomy. The development of feudalism and the spread of the Christian religion led to a significant decline in the natural sciences, and the development of astronomy in Europe slowed down for many centuries. In the era of the gloomy Middle Ages, astronomers were engaged only in observations of the apparent movements of the planets and the coordination of these observations with the accepted geocentric system of Ptolemy.
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During this period, astronomy received rational development only among the Arabs and the peoples of Central Asia and the Caucasus, in the works of outstanding astronomers of that time. Al-Battani (850-929) Biruni (973-1048) Ulugbek (1394-1449)
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The development of trade and navigation urgently required the improvement of astronomical knowledge and, in particular, the theory of planetary motion. The development of productive forces and the requirements of practice, on the one hand, and the accumulated observational material, on the other, prepared the ground for a revolution in astronomy, which was produced by the great Polish scientist Nicolaus Copernicus (1473-1543), who developed his heliocentric system of the world, published in the year his death.
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The new astronomy gained the opportunity to study not only the visible, but also the actual motions of celestial bodies. Her numerous and brilliant successes in this area were crowned in the middle of the 19th century. the discovery of the planet Neptune, and in our time - the calculation of the orbits of artificial celestial bodies.
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Astrophysics arose, which received especially great development in the 20th century. and continues to grow rapidly today. In the 40s. 20th century radio astronomy began to develop, and in 1957 the foundation was laid for qualitatively new research methods based on the use of artificial celestial bodies, which later led to the emergence of a virtually new branch of astrophysics - x-ray astronomy
What is astronomy? Astronomy studies the structure of the universe, the physical nature, origin and evolution of celestial bodies and the systems they form. Astronomy also explores the fundamental properties of the universe around us. As a science, astronomy is based primarily on observations. Unlike physicists, astronomers are deprived of the opportunity to experiment. Almost all information about celestial bodies is brought to us by electromagnetic radiation. Only in the last 40 years have individual worlds been studied directly: by probing the atmospheres of planets, by studying the lunar and Martian soil. The scale of the observable Universe is huge and the usual units of measurement of distances - meters and kilometers - are of little use here. They are replaced by others.
The astronomical unit is used in the study of the solar system. This is the size of the semi-major axis of the Earth's orbit: 1 AU = 149 million km. Larger units of length - the light year and parsec, as well as their derivatives - are needed in stellar astronomy and cosmology. A light year is the distance traveled by a light beam in vacuum in one Earth year. The parsec is historically associated with the measurement of distances to stars by their parallax and is 3.263 light years = a. e. Astronomy is closely connected with other sciences, primarily with physics and mathematics, the methods of which are widely used in it. But astronomy is also an indispensable testing ground on which many physical theories are tested. Space is the only place where matter exists at temperatures of hundreds of millions of degrees and near absolute zero, in the void of vacuum and in neutron stars. Recently, the achievements of astronomy have been used in geology and biology, geography and history.
Astronomy studies the fundamental laws of nature and the evolution of our world. Therefore, its philosophical significance is especially great. In fact, it determines the worldview of people. The oldest of sciences. Several thousand years before our era, landowners settled in the valleys of large rivers (Nile, Tigris and Euphrates, Indus and Ganges, Yangtze and Huang He). The calendar compiled by the priests of the Sun and the Moon began to play an important role in their lives. The priests carried out observations of the luminaries in ancient observatories, which were also temples at the same time. They are studied by archaeoastronomy. Archaeologists have found quite a few similar observatories.
The simplest of them - megaliths - consisted of one (menhirs) or several (dolmens, cromlechs) stones arranged in a strict order relative to each other. Megaliths marked the place of sunrise and sunset of the luminaries at a certain time of the year. One of the most famous buildings of antiquity is Stonehenge, located in southern England. Its main function is to observe the Sun and Moon, determine the days of the winter and summer solstices, predict lunar and solar eclipses.
Astronomy of ancient civilizations Approximately 4 thousand years BC. in the Nile Valley, one of the oldest civilizations on Earth, the Egyptian, arose. A thousand years later, after the unification of the two kingdoms (Upper and Lower Egypt), a powerful state was formed here. By that time, which is called the Old Kingdom, the Egyptians already knew the potter's wheel, knew how to smelt copper, and invented writing. It was during this era that the pyramids were built. At the same time, Egyptian calendars probably appeared: lunar-stellar - religious and schematic - civil. The astronomy of the Egyptian civilization began precisely with the Nile. Egyptian priest-astronomers noticed that shortly before the start of the rise of water, two events occur: the summer solstice and the first appearance of Sirius on the morning star after a 70-day absence from the sky. Sirius, the brightest star in the sky, was named by the Egyptians after the goddess Sopdet. The Greeks pronounced this name as "Sothis". By that time in Egypt there was a lunar calendar of 12 months of 29 or 30 days - from new moon to new moon. In order for its months to correspond to the seasons of the year, a 13th month had to be added every two or three years. "Sirius" helped to determine the time of insertion of this month. The first day of the lunar year was considered the first day of the new moon, which occurred after the return of this star.
Such an "observational" calendar with an irregular addition of a month was ill-suited for a state where strict accounting and order existed. Therefore, the so-called schematic calendar was introduced for administrative and civil needs. In it, the year was divided into 12 months of 30 days with the addition of an additional 5 days at the end of the year, i.e. contained 365 days. The Egyptians knew that the true year was a quarter of a day longer than the introduced one, and it was enough to add in every fourth, leap year, instead of five, an additional six days to harmonize it with the seasons. But this was not done. For 40 years, i.e. the life of one generation, the calendar went ahead by 10 days, not such a noticeable amount, and the scribes who managed the economy could easily adapt to the slow changes in the dates of the onset of the seasons. After some time, another lunar calendar appeared in Egypt, adapted to a sliding civil one. In it, additional months were inserted in such a way as to keep the beginning of the year not near the moment of the appearance of Sirius, near the beginning of the civil year. This "wandering" lunar calendar was used along with the other two.
Ancient Egypt had a complex mythology with many gods. The astronomical conceptions of the Egyptians were closely connected with it. According to their beliefs, in the middle of the world was Geb, one of the progenitors of the gods, the breadwinner and protector of people. He personified the Earth. Geb's wife and sister, Nut, was Heaven itself. She was called the Great Mother of the Stars and the Birth of the Gods. It was believed that every morning she swallows the luminaries and every evening gives birth to them again. Because of this habit of hers, Nut and Geb once had a quarrel. Then their father Shu, Air, raised the Sky above the Earth and separated the spouses. Nut was the mother of Ra (Sun) and the stars and ruled over them. Ra, in turn, created Thoth (Moon) as his deputy in the night sky. According to another myth, Ra floats on the celestial Nile and illuminates the Earth, and in the evening descends to the Duat (hell). There he travels along the underground Nile, fighting the forces of darkness, in order to reappear on the horizon in the morning.
Geocentric system of the world In the II century BC. Greek scientist Ptolemy put forward his "system of the world." He tried to explain the structure of the universe, taking into account the apparent complexity of the movement of the planets. Considering the Earth is spherical, and its dimensions are negligible in comparison with the distances to the planets, and even more so to the stars. Ptolemy, however, following Aristotle, argued that the Earth is the fixed center of the Universe, his system of the world was called geocentric. Around the Earth, according to Ptolemy, the Moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and stars move (in order of distance from the Earth). But if the motion of the Moon, Sun, stars is circular, then the motion of the planets is much more complicated.
Each of the planets, according to Ptolemy, does not move around the Earth, but around a certain point. This point, in turn, moves in a circle, in the center of which is the Earth. The circle described by the planet around the moving point, Ptolemy called the epicycle, and the circle along which the point moves around the Earth, the deferent. This false system has been recognized for almost years. It was also recognized by the Christian religion. Christianity based its worldview on the biblical legend of the creation of the world by God in 6 days. According to this legend, the Earth is the "concentration" of the Universe, and the heavenly bodies were created in order to illuminate the Earth and decorate the firmament. Any deviation from these views was mercilessly pursued by Christianity. The system of the world of Aristotle - Ptolemy, which placed the Earth at the center of the universe, perfectly corresponded to the Christian doctrine. The tables compiled by Ptolemy made it possible to determine in advance the position of the planets in the sky. But over time, astronomers have discovered a discrepancy between the observed positions of the planets and the predicted ones. For centuries, it was thought that the Ptolemaic system of the world was simply not perfect enough, and in an attempt to improve it, they introduced new and new combinations of circular motions for each planet.
The heliocentric system of the world The great Polish astronomer Nikolai Copernicus () outlined his system of the world in the book “On the Rotations of the Celestial Spheres”, which was published in the year of his death. In this book, he proved that the universe is not arranged in the way that religion has claimed for many centuries. Long before Ptolemy, the Greek scientist Aristarchus argued that the Earth moves around the Sun. Later, in the Middle Ages, advanced scientists shared the point of view of Aristarchus on the structure of the world and rejected the false teachings of Ptolemy. Shortly before Copernicus, the great Italian scientists Nicholas of Cusa and Leonardo da Vinci argued that the Earth moves, that it is not at all in the center of the Universe and does not occupy an exceptional position in it. Why, in spite of this, did the Ptolemaic system continue to dominate? Because it relied on the all-powerful church authority, which suppressed free thought, hindered the development of science. In addition, scientists who rejected the teachings of Ptolemy and expressed correct views on the structure of the Universe could not yet convincingly substantiate them. This was done only by Nicolaus Copernicus. After 30 years of hard work, much thought and complex
Mathematical calculations, he showed that the Earth is only one of the planets, and all the planets revolve around the Sun. What does the book "On the rotation of the heavenly spheres" contain and why did it deal such a crushing blow to the Ptolemaic system, which, with all its flaws, had been kept for 14 centuries under the auspices of the all-powerful church? In this book, Nicolaus Copernicus argued that the Earth and other planets are satellites of the Sun. He showed that it is the movement of the Earth around the Sun and its daily rotation around its axis that explains the apparent movement of the Sun, the strange entanglement in the movement of the planets, and the apparent rotation of the firmament. Brilliantly simple, Copernicus explained that we perceive the movement of distant celestial bodies in the same way as the movement of various objects on Earth when we ourselves are in motion. Copernicus, like the ancient Greek scientists, suggested that the orbits along which the planets move can only be circular. After 75 years, the German astronomer Johannes Kepler, the successor of Copernicus, proved that if the Earth moved in space, then when observing the sky at different times, it would seem to us that the stars are shifting, changing their position in the sky. But no astronomer has noticed such displacements of stars for many centuries. It was in this that the supporters of the teachings of Ptolemy wanted to see evidence of the immobility of the Earth. However, Copernicus argued that the stars are at unimaginably great distances. Therefore, their insignificant shifts could not be noticed.
Classics of Celestial Mechanics The century after Newton's death (1727) was a time of rapid development of celestial mechanics, a science based on the theory of gravity. And it just so happened that the main contribution to the development of this science was made by five remarkable scientists. One of them is from Switzerland, although he worked most of his life in Russia and Germany. This is Leonardo Euler. The other four are French (Clero, D'Alembert, Lagrange and Laplace). In 1743, d'Alembert published his "Treatise on Dynamics", which formulated the general rules for compiling differential equations describing the motion of material bodies and their systems. In 1747, he submitted to the Academy of Sciences memoirs on the deviations of the planets from elliptical motion around the Sun under the influence of their mutual attraction. Alexis Claude Clairaut () at the age of less than 13 made his first scientific work on geometry. It was presented to the Paris Academy, where it was read by his father. Three years later, Clairaut published a new work - "On curves of double curvature." Youthful work attracted the attention of prominent mathematicians. They began to seek the election of a young talent to the Paris Academy of Sciences. But according to the charter, only a person who had reached the age of 20 could become a member of the Academy.
Then the famous mathematician Pierre Louis Maupertuis (), the patron of Alexis, decided to take him to Basel to Johann Bernoulli. For three years, Clairaut listened to the lectures of a venerable scientist, improving his knowledge. Upon his return to Paris, having already reached the age of 20, he was elected to the adjunct of the Academy (junior rank of academicians). In Paris, Clairaut and Maupertuis plunged into the midst of a debate about the shape of the Earth: is it compressed at the poles or elongated? Maupertuis began to prepare an expedition to Lapland to measure the arc of the meridian. Clairaut also took part in it. Returning from Lapland, Clairaut received the title of full member of the Academy of Sciences. His life was now secure and he was able to devote it to scientific pursuits. Joseph Louis Lagrange () studied and then taught at the Artillery School in Turin, already becoming a professor at the age of 18. In 1759, on the recommendation of Euler, the 23-year-old Lagrange was elected a member of the Berlin Academy of Sciences. In 1766, he already became its president. The range of Lagrange's scientific research was extraordinarily wide. They are devoted to mechanics, geometry, mathematical analysis, algebra, number theory, as well as theoretical astronomy. The main direction of Lagrange's research was the presentation of the most diverse phenomena in mechanics from a single point of view. He derived an equation describing the behavior of any systems under the action of forces. In the field of astronomy, Lagrange did much to solve the problem of the stability of the solar system; proved some particular cases of stable motion, in particular for small bodies located at the so-called triangular libration points. These bodies are asteroids
"Trojans" - were discovered already in the 20th century, a century after the death of Lagrange. In solving specific problems of celestial mechanics, the paths of these scientists repeatedly crossed; they voluntarily or involuntarily competed with each other, coming either to close, or to completely different results. Modern Astronomy The whole history of the study of the Universe is, in essence, the search for means that improve human vision. Until the beginning of the 17th century, the naked eye was the only optical instrument of astronomers. The whole astronomical technique of the ancients was reduced to the creation of various goniometric instruments, as accurate and durable as possible. Already the first telescopes immediately sharply increased the resolving and penetrating power of the human eye. The universe turned out to be completely different than it had seemed until then. Gradually, receivers of invisible radiation were created, and at present we perceive the universe in all ranges of the electromagnetic spectrum - from gamma rays to ultra-long radio waves. Moreover, corpuscular radiation receivers have been created that capture the smallest particles - corpuscles (mainly atomic nuclei and electrons) that come to us from celestial bodies. If you are not afraid of allegories, we can say that the Earth has become sharper, its "eyes", that is, the totality of all cosmic radiation receivers, are capable of
To fix objects from which rays of light reach us for many billions of years. Thanks to telescopes and other instruments of astronomical technology, over three and a half centuries, man has penetrated such cosmic distances, where light - the fastest thing in this world - can only reach in billions of years! This means that the radius of the universe studied by mankind is growing at a speed that is many times greater than the speed of light! Spectral analysis - the study of the intensity of radiation in individual spectral lines, in individual parts of the spectrum. Spectral analysis is a method by which the chemical composition of celestial bodies, their temperature, size, structure, distance to them and the speed of their movement are determined. In 50 years, presumably, planets near the nearest 5-10 stars will be discovered (if any). Most likely they will be detected in the optical, infrared and submillimeter wave ranges from extra-atmospheric installations. In the future, interstellar probe ships will appear to fly to one of the nearest stars within 5-10 light years, of course, to the one near which the planets will be discovered. Such a ship will move at a speed of no more than 0.1 of the speed of light with the help of a thermonuclear engine.
2000 years ago, the distance of the Earth from the Sun, according to Aristarchus of Samos, was about 361 Earth radii, i.e. about km. Aristotle believed that the "sphere of stars" is located 9 times further. Thus, the geometric scales of the world 2000 years ago were "measured" by the value in km. With the help of modern telescopes, astronomers observe objects located at a distance of about 10 billion light years. Thus, over the mentioned period of time, the scale of the world has grown by several times. According to Byzantine Christian theologies, the world was created 5508 BC, i.e. less than 7.5 thousand years ago. Modern astronomy has provided evidence that already about 10 billion years ago the Universe available for astronomical observations existed in the form of a giant system of galaxies. Scales in time "grew" in 13 million times. But the main thing, of course, is not in the digital growth of spatial and temporal scales, although they are breathtaking. The main thing is that man has finally reached the broad path of understanding the real laws of the universe.
