History Of Astronomy In Ancient Times (Part I)
The first reported records of periodic astronomical statements date back to the Assyro-Babylonians around 1000 BCE. From this seedbed of culture in Mesopotamia – in the southern part of present-day Iraq – astronomers had made up details of the heavenly bodies and registered their periodic movements.
Mesopotamia
The origins and birth of Western astronomy can be found in the civilizations of Mesopotamia, "the lands between the Tigris and Euphrates rivers," where the ancient kingdoms of Sumer, Assyria, and Babylon were located. A type of writing known as cuneiform was popular among the Sumerians around 3500-3000 BC. Our current knowledge of Sumerian astronomy is indirect and comes from the earliest Babylonian star lists of about 1200 BC. The fact that many star names appear in the Sumerian language indicates continuity to the Early Bronze Age. Astral theology was famous for the planetary gods and played an important role. This stellar theology began with the Sumerians in Mesopotamian mythology and religion.
The Sumerians also used a place value number system that simplified recording large and tiny numbers. The Sumerians also invented and started the modern method of dividing a circle into 360 degrees or an hour into 60 minutes.
Classical sources often use the word Chaldeans for Mesopotamian astrologers, priest-scribes specializing in astrology, and other forms of prediction based on astrological or superstitious principles.
The first evidence of recognizing the periodicity of astronomical phenomena and using mathematics in predicting them is related to Babylon. When did the ancient Babylonian tablets document the use of mathematics in changing the length of daylight during a solar year? Centuries of Babylonian observations of celestial phenomena have been recorded in a series of cuneiform tablets called "Yinuma Anu Enlil." The oldest significant astronomical text in our possession is Tablet 63 of the same collection, the Venus Tablet of Ami Saduke, which lists Venus's first and last apparent risings over a 21-year period and is the first evidence to document this phenomenon. It shows.
A significant increase in the quality and frequency of Babylonian observations appeared during the reign of Nabunsar (747-733 BC). For example, the systematic recording of ominous phenomena in Babylonian astronomical diaries that began around this time allowed the discovery of a repeating 18-year cycle of lunar eclipses.
Greek astronomer Claudius Ptolemy used Nabunsar's reign several hundred years later to establish the beginning of an era, as she felt that the first usable observations began at this time.
The final stages of the development of Babylonian astronomy occurred during the Seleucid Empire (323-60 BC). In the 3rd century BC, astrologers began using "target year texts" to predict planetary movements. These texts compiled records of past observations to find recurrences of ominous phenomena for each planet. Around the same time, or shortly after, astronomers developed mathematical models that allowed them to predict these phenomena without consulting records directly. One of the prominent Babylonian astronomers at this time was the Seleucus of Seleucia, who was a fan of the halocentric model.
Babylonian astronomy was the foundation of many works in Greek and Hellenistic astronomy, classical Indian astronomy, Sassanid Iran, Byzantium, Syria, Islamic astronomy, Central Asia, and Western Europe.
India
Astronomy in the sugar subcontinent dates back to the Indus Valley Civilization in the 3rd millennium BC when it was used to create a calendar. Since the Indus Valley Civilization did not leave written records, the oldest extant Indian astronomical text is the Vedanga Jyotisha, which dates back to the Vedic period. The Vedanga Jyotisha is attributed to Lagada and has an internal date of approximately 1350 BCE and describes rules for tracking the movements of the Sun and moon for ritual purposes. These documents are available in two versions, one belonging to the Rig Veda and the other to the Yajur Veda. According to Vedanga Jyotisha, there are five solar years, 67 mahri cycles, 1830 days or 1835 unreal days, and 62 synodic months in yoga or age. During the sixth century, astronomy was affected by Greek and Byzantine astronomical practices.
Aryabhata (476-550), in 499 AD, proposed a system of calculations based on a planetary model, in which the Earth was considered to be rotating on its axis and the periods of the planets concerning the Sun. Early supporters of Aryabhata's model contained Varahamihira, Brahmagupta, and Bhaskara II.
Astronomy made significant progress during the Shunga Empire, producing many astronomical documents. The Shunga period is known as the "Golden Age of Indian Astronomy." During this period, he witnessed the development of calculations for the movements and locations of different planets, their sunrises and sunsets, correlations, and eclipse calculations.
Indian astronomers in the 6th century believed that comets were celestial bodies that periodically reappeared. This was a view expressed in the 6th century by astrologers such as Varahamihira and Bhadrabahu. The 10th-century astrologer Batutpala listed some comets' names and estimated periods, but it needs to be clarified how these figures were calculated or how accurate they are.
Bhaskara II (1114-1185) was the head of the astronomical observatory at Ujjain, which continued the mathematical practices of Brahmagupta. He wrote the Siddhantasirumani, divided into Gladhayaya (Globe) and Grahaganita (Mathematics of the Planets). He also calculated the time of the Earth's rotation around the Sun to 9 decimal places. Nalanda Buddhist University at that time offered formal courses in astronomical studies.
Other critical Indian astronomers include Madhava of Sangamgrama, Niklakantha Somayaji, and Jishtadeva, who were members of the Kerala School of Astronomy and Mathematics from the 14th to the 16th century. Niklakanta Somayaji and Jishtadeva himself, a commentary on Aryabhata, developed his computational system on a subtropical planetary model in which Mercury, Venus, Mars, Jupiter, and Saturn revolved around the Sun, which in turn revolved around the Earth, similar to the Tychonic system, was later proposed by Tycho Brahe in the late 16th century.
However, the Nilakanta system was mathematically more efficient than the Tychonic system due to the proper consideration of the equation of the center and the transverse motion of Mercury and Venus. Most astronomers of the Kerala School of Astronomy and Mathematics who observed him took his planetary example.
