Sumer and Babylon
The Sumerian-Akkadian state of Babylon existed from the II millennium BC to the VI century BC (in recent decades it was ruled by the Chaldeans, and in the VI century BC Persia took over the country). The Babylonian priests left many astronomical tables. They also identified the main constellations and the zodiac, introduced the division of the full angle by 360 °, and developed trigonometry. Observation of the equinox at the prehistoric Pizzo Vento site in Fondacelli Fantina, Sicily In the II millennium BC, the Sumerians had a lunar calendar, improved in the I millennium BC. The year consisted of 12 synodic months — six for 29 days and six for 30 days, a total of 354 days. At first, in order to coordinate with the solar year (the duration of which they determined to be 365 days), they inserted the 13th month, but then they stopped doing it. Having processed their tables of observations, the priests discovered many laws of the motion of the planets, the Moon and the Sun, could predict eclipses. In 450 BC, the Babylonians already knew the "Metonic cycle" (235 months coincide with 19 solar years with great accuracy). However, the Chinese discovered it even earlier. Probably, it was in Babylon that the seven-day week appeared (each day was dedicated to one of the 7 luminaries).Ancient Egypt
The floods of the Nile occur at the beginning of summer, and just at this time the first sunrise of the brightest star of the sky — Sirius, called "Sothis" in Egyptian, falls. Up to this point, Sirius is not visible. This is probably why the "sotic" calendar was used in Egypt along with the civil one. The Sothic year is the period between the two heliacal sunrises of Sirius, that is, it coincided with the sidereal year, and the civil year consisted of 12 months of 30 days plus five additional days, a total of 365 days. At first there were no weeks, the month was divided into 3 decades. A lunar calendar with a metonic cycle, coordinated with the civil one, was also used in Egypt. Later, under the influence of Babylon, a seven-day week appeared. The day was divided into 24 hours, which at first were unequal (separately for light and dark), but at the end of the IV century BC acquired a modern look. In Egypt, unlike Babylon, the decimal system was used, but in days, except for 10 light hours, they allocated another hour for transitional periods, so it turned out 12 hours; the same for the dark time of the day. The degree of development of Egyptian mathematics and astronomy is unclear. There are almost no documents on this topic, but the Hellenes highly valued Egyptian astronomers and studied with them. Astrology did not appear in Egypt (according to the general opinion of historians, in Mesopotamia), but divination by the Moon and planets was used very widely there. The Egyptian system of the world, according to the description of Heraclides of Pontus (IV century BC), was geocentric, but Mercury and Venus revolve around the Sun (although with it — around the Earth). The upper planets (which can be observed in opposition to the Sun) were considered in ancient Egypt to be incarnations of the god Horus, while the Egyptians took the lower planets as one, without making any distinctions between them. The Egyptians divided the sky into constellations. This can be evidenced by references in texts, as well as drawings on the ceilings of temples and tombs. A total of 45 constellations were known in ancient Egypt. For example, the constellation Mes (apparently the Big Dipper) is mentioned; the constellation AN in the form of a figure with the head of a falcon piercing the constellation Mes with a spear.Ancient Greece
The Hellenes, apparently, were interested in astronomy back in Homeric times, their sky map and many names have remained in modern science. Initially, the knowledge was shallow — for example, the morning and evening Venus were considered different luminaries (Phosphorus and Hesperus); the Sumerians already knew that this was the same luminary [source not specified 1176 days]. Correction of the error of the "bifurcation of Venus" is attributed to Pythagoras and Parmenides. The pole of the world at that time had already left the Alpha of the Dragon, but had not yet moved closer to the Polar One; perhaps that is why the direction to the north is never mentioned in the Odyssey. The Pythagoreans proposed a pyrocentric model of the universe in which the stars, the Sun, the Moon and six planets revolve around a Central Fire (Hestia). In order to get the sacred number — ten — spheres, the sixth planet was declared the Anti-Earth (Antichthon). Both the Sun and the Moon, according to this theory, shone with the reflected light of Hestia. This was the first mathematical system of the world — the rest of the ancient cosmogonists had imagination rather than logic. The distances between the spheres of the luminaries of the Pythagoreans corresponded to musical intervals in the scale; when they rotate, the "music of the spheres" sounds unheard by us. The Pythagoreans considered the Earth spherical and rotating, which is why there is a change of day and night. However, some Pythagoreans (Aristarchus of Samos and others) adhered to the heliocentric system. The Pythagoreans also had the concept of ether for the first time, but most often this word meant air. Only Plato isolated the ether as a separate element. Plato, a disciple of Socrates, no longer doubted the spherical shape of the Earth (even Democritus considered it a disk). According to Plato, the Cosmos is not eternal, since everything that is felt is a thing, and things age and die. Moreover, Time itself was born together with the Cosmos. Plato's call to astronomers to decompose the uneven movements of the luminaries into "perfect" movements along circles had far-reaching consequences. This call was answered by Eudoxus of Cnidus, the teacher of Archimedes and himself a disciple of the Egyptian priests. In their (not preserved) In his writings, he outlined a kinematic scheme of planetary motion with several superimposed circular motions, a total of 27 spheres. However, the agreement with observations for Mars was bad. The fact is that the orbit of Mars is noticeably different from the circular one, so that the trajectory and speed of the planet's movement across the sky vary widely. Evdox also compiled a star catalog. Aristotle, the author of Physics, was also a disciple of Plato. There were a lot of rational thoughts in his writings; he convincingly proved that the Earth — sphere, based on the shape of the Earth's shadow during lunar eclipses, estimated the circumference of the Earth at 400,000 stadia, or about 70,000 km — overestimated almost twice, but for that time the accuracy is not bad. But there are also many erroneous statements: the separation of the earthly and heavenly laws of the world, the denial of emptiness and atomism, the four elements as the fundamental principles of matter plus the heavenly ether, contradictory mechanics: "the arrow in flight is pushed by the air" — even in the Middle Ages this ridiculous position was ridiculed (Philopon, Buridan). He considered meteors to be atmospheric phenomena akin to lightning. Aristotle's concepts were canonized by some philosophers during his lifetime, and in the future many sound ideas that contradict them were met with hostility — for example, the heliocentrism of Aristarchus of Samos. Aristarchus also tried for the first time to measure the distance to the Sun and Moon and their diameters; for the Sun, he was mistaken by an order of magnitude (it turned out that the diameter of the Sun is 250 times larger than the Earth's), but before Aristarchus, everyone believed that the Sun was smaller than the Earth. That's why he decided that the Sun was at the center of the world. More accurate measurements of the angular diameter of the Sun were made by Archimedes, in his retelling we know the views of Aristarchus, whose writings are lost. Eratosthenes in 240 BC fairly accurately measured the length of the earth's circumference and the inclination of the ecliptic to the equator (i.e., the inclination of the earth's axis); he also proposed a system of leap years, later called the Julian calendar [source not specified 1176 days]. Since the third century BC, Greek science has assimilated the achievements of the Babylonians, including in astronomy and mathematics. But the Greeks went much further. Around 230 BC Apollonius of Perga developed a new method of representing uneven periodic motion through the base circle — the deferent — and the secondary circle circling around the deferent — the epicycle; the luminary itself moves along the epicycle. This method was introduced into astronomy by the outstanding astronomer Hipparchus, who worked in Rhodes. Hipparchus discovered the difference between tropical and sidereal years, specified the length of the year (365.25 — 1/300 days). Apollonius' method allowed him to construct a mathematical theory of the motion of the Sun and Moon. Hipparchus introduced the concepts of orbital eccentricity, apogee and perigee, specified the duration of the synodic and sidereal lunar months (to the nearest second), the average periods of the planets' rotation. According to the tables of Hipparchus, it was possible to predict solar and lunar eclipses with an unprecedented accuracy for that time — up to 1-2 hours. By the way, it was he who introduced geographical coordinates — latitude and longitude. But the main result of Hipparchus was the discovery of the displacement of celestial coordinates — the "precession of the equinoxes". After studying the observation data for 169 years, he found that the position of the Sun at the time of the equinox shifted by 2°, or 47" per year (in fact, by 50.3"). In 134 BC, a new bright star appeared in the constellation of Scorpio [source not specified 1176 days]. To make it easier to track changes in the sky, Hipparchus compiled a catalog for 850 stars, dividing them into 6 classes by brightness. 46 BC: The Julian calendar was introduced, developed by the Alexandrian astronomer Sozigen on the model of the Egyptian civil calendar. The Hipparchus system was completed by the great Alexandrian astronomer, mathematician, optician and geographer Claudius Ptolemy. He significantly improved spherical trigonometry, compiled a table of sines (after 0.5 °). But his main achievement is "Megale syntax" (Large construction); the Arabs turned this name into "Al Majisti", hence the later "Almagest". The work contains a fundamental exposition of the geocentric system of the world. Being fundamentally incorrect, Ptolemy's system, nevertheless, made it possible to calculate the positions of the planets in the sky with sufficient accuracy for that time and therefore satisfied, to a certain extent, practical needs for many centuries. Ptolemy's world system completes the stage of development of ancient Greek astronomy. The spread of Christianity and the development of feudalism in the Middle Ages led to a loss of interest in the natural sciences, and the development of astronomy in Europe slowed down for many centuries.Ancient China
Of the countries of East Asia, ancient astronomy received the greatest development in China. Already during the legendary Xia Dynasty (late III — early II thousand BC), there were two positions of court astronomers in China. According to legend, in 2137 BC, astronomers Ho and Hee were executed for failing to predict an eclipse. A lot of astronomical information is contained in the monument of Chinese literature "Shi Jing" ("Book of Songs") (~ VI century BC). Around the same time, the Chinese specified the duration of the solar year (365.25 days). Accordingly, the celestial circle was divided into 365.25 degrees or 28 constellations (according to the movement of the Moon). Observatories appeared in the XII century BC. But much earlier, Chinese astrologers diligently recorded all unusual events in the sky (eclipses, comets — "broom stars", meteor showers, new stars). The first record of the appearance of a comet dates back to 631 BC, about a lunar eclipse — to 1137 BC, about a solar eclipse — to 1328 BC, the first meteor shower was described in 687 BC. The earliest unambiguously identifiable message about Halley's comet dates back to 240 BC. that the observed comet of 466 BC is also the appearance of Halley's comet. Starting from 87 BC . e. all subsequent appearances are marked. In 301, sunspots were first noticed; later they were recorded repeatedly. Among other achievements of Chinese astronomy, we note the correct explanation of the causes of solar and lunar eclipses, the discovery of the uneven motion of the Moon, the measurement of the sidereal period first for Jupiter (12 years, the exact value: 11.86), and since the III century BC — and for all other planets, both sidereal and synodic, with good accuracy. There were many calendars in China. By the VI century BC, the Metonic cycle was discovered and the lunisolar calendar was established. The beginning of the year is the winter solstice, the beginning of the month is the new moon. The day was divided into 12 hours (the names of which were also used as the names of months) or into 100 parts. Calendar reforms in China were carried out constantly. The years were combined into a 60-year cycle: each year was dedicated to one of the 12 animals (Zodiac) and one of the 5 elements: water, fire, metal, wood, earth. Each element corresponded to one of the planets; there was also a sixth — primary — element "qi" (ether). Later, qi was divided into several types: yin-qi and yang-qi, and others, in accordance with the teachings of Lao Tzu (VI century BC).India
Main article: Indian Astronomy The Indians had no notable successes in astronomy — unlike mathematics —; later they willingly translated and commented on Greek writings. The earliest information about the knowledge of Indians in the field of natural sciences belongs to the era of the Indian civilization, dating back to the III millennium BC. In the Vedic era in India, the universe was considered divided into three different parts: the sky, the firmament and the Earth, as evidenced by the Vedic literature of those times. Indian scientists, unlike Babylonian and ancient Chinese, were practically not interested in studying stars and did not make star catalogues. In the V century A.D., astronomer and mathematician Ariabhata suggested that the planets rotate around their axis. He also correctly explained the causes of solar and lunar eclipses and predicted several upcoming eclipses. His views aroused the indignation of devout Hindus, to whom even Brahmagupta joined: The followers of Ariabhata say that the Earth is moving and the sky is at rest. But in their refutation it was said that if this were the case, then stones and trees would fall from the Ground… There are some people who think that eclipses are not caused by the Head [of the dragon Rahu]. This is an absurd opinion, because it is she who causes eclipses, and most people in the world say that it is she who causes them. In the Vedas, which are the Word of God, it is said from the mouth of Brahma that the Head causes eclipses. On the contrary, Ariabhata, going against everyone, out of hostility to the sacred words mentioned, claims that the eclipse is caused not by the Head, but only by the Moon and the shadow of the Earth… These authors must submit to the majority, because everything in the Vedas is sacred. Although science in India declined after the Muslim conquest (XI century), some major scientific achievements belong to Bhaskar II in the XII century. Inca Empire Main article: Inca Astronomy Inca astronomy is directly related to cosmology and mythology, since each waka (sacred place on earth) reflected a certain celestial body or phenomenon. This is reflected in many legends, where, at the creation of the world, celestial objects descended into the ground, and then again emerged from rocks, caves, springs, that is, from every uaka. The peoples themselves came out of them, according to the ideas of the Incas. The primary celestial object was considered to be the Milky Way ("Mayu" — River), on which or near which all smaller significant objects are located. The positions of the Maya during periods when, as a result of the rotation of the earth, the axis of the Milky Way deviates as much as possible in one direction and in the other from the North—South line, mark the boundaries dividing the world into four sectors. On the ground, two central streets of the village (and the roads that continue them) and irrigation canals intersect at approximately the same angle. The Incas knew the difference between stars (Quechua Quyllur) and planets (Quechua Hatun quyllur). It is known for sure that they observed Venus (Ch'aska), Jupiter (Pirva) and Saturn (Haucha), there is no reliable information about their observation of Mercury and Mars. Inca names of planets give reason to believe that Inca astronomers were aware of the Galilean moons of Jupiter and the fuzziness of the edges of the disk of Venus caused by the atmosphere. Measurements were carried out on the pillars or stones placed on the hills and hills near Cuzco: two to the East of the city, and two to the West. The sun came out and set through them when it reached the Tropic of Cancer and Capricorn. The two stones used to determine the beginning of winter were called Pukui-Sukanka; the other two, which marked the beginning of summer, were called Chirav(?)-Sukanka. Jose de Acosta mentions 12 pillars. He calls them Succanga. Antonio de la Calancha gives information about 8 pillars on the east side and 8 pillars on the west. It seems that already in the middle of the XVI century, after the Spanish conquest, these pillars in Cuzco were abandoned and surveillance of them ceased or weakened.Central America
The Maya civilization (II—X century AD) attached great importance to astronomical knowledge, which is proved by numerous archaeological excavations at the sites of cities of this civilization. Ancient Maya astronomers were able to predict eclipses, and very carefully observed various, most clearly visible astronomical objects, such as the Pleiades, Mercury, Venus, Mars and Jupiter. The remains of cities and temples-observatories look impressive. Unfortunately, only 4 manuscripts of different ages and texts on steles have been preserved. The Maya conducted astronomical research without any instruments at all, standing on the tops of pyramids-"observatories". The only tool they used was crossed sticks to fix the observation point. The priests who study the stars are depicted together with the devices in the manuscripts of Nuttall, Selden and Botley. The Maya determined the synodic periods of all 5 planets with great accuracy (Venus was especially revered), and came up with a very accurate calendar. The month of Maya contained 20 days, and the week - 13. The beginning of the calendar era is attributed to 1738 BC, although the chronology of his people was conducted from 3113 BC.