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# 2.23 Indian Astronomy

India was a major center of ancient knowledge. Astronomy is referenced in the Rigveda, one of the foremost texts of Hinduism, created between 1700 and 1100 B.C. In this and other. Vedic texts,astronomy is interlaced with religious tradition so it is sometimes hard to tell them apart. Astronomical practices in India date back to about 1500 B.C. Indian texts dating from around 450 A.D. used Greek computational methods and referred to the longitudes of both Alexandria and Benares, a major Indian astronomical center. Indian mathematicians invented the number system that uses zero, which is the basis of our decimal system. The first known astronomy text in India appeared in about 600 A.D. Written by Aryabhata, it described planetary motions and eclipses. By this time, India had extensive contact with the Mesopotamian and Greek worlds, and influences probably traveled both ways. However, Aryabhata had original ideas that were not widely accepted elsewhere. He adopted a heliocentric model and believed that the Moon reflected the light of the Sun and the Earth rotated rather than the skies. Around the same time, Varihamihara proposed that the same force holding objects to the Earth also held celestial objects in place, anticipating a much later Newtonian concept. Aryabhata and his contemporaries treated the orbits of the planets as elliptical rather than circular, another example of being a thousand years ahead of their time.

Aryabhata, mathematician and astronomer in Ancient India. Click here for original source URL

.Unfortunately, invaders in the 12th century destroyed most of the records of this fertile early period of Indian science. When we judge the scientific contributions of other cultures, we must remember that the historical record is often obscured by conquest (climate can be important too; many artifacts from Mesopotamia and Egypt survived because the Middle East is so dry). The great astronomical observatory at Benares was destroyed in 1194, and various university libraries of Buddhist and other ancient literature were burned in religious wars. A massive observatory — one of the world’s five major observatories by the 1700s — was reestablished at Benares in later centuries (and then damaged yet again by a new wave of invaders). In the later phase of Indian astronomy, during the reign of the Mughal emperors, the most impressive achievements were large observatories. The Maharaja of Jaipur built five observatories, and largest of these, Jantar Mantar, is a major tourist attraction in India. Indian metallurgists created metal celestial globes without seams in the 10th Century, thought to be impossible without modern technology. Throughout this time, there was a flow of astronomical ideas and data between East and West.

Jantar Mantar observatory in New Delhi, India. Click herefor original source URL.