Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
112<br />
Astronomy<br />
Like other disciplines of Indian thought, astronomy and its origins<br />
may be genetically related back to the Vedas. The Vedic Aryans<br />
were well acquainted with the natural routine cycles of heavenly<br />
bodies. The vault of the sky, for example, was seen as being<br />
governed by the eternal ordinances of an inherent universal<br />
principle, Rita (literally, the course of things), which determines<br />
the paths and phases of the moon and the planets, the day/night<br />
cycle and occurrences of eclipses.<br />
The Jyotisha Vedanga and the Surya Prajnapati (c. 400 BC-AD 200)<br />
record the earliest Hindu astronomical statements. In early times,<br />
astronomy developed out of pragmatic speculations which were<br />
necessary and therefore of paramount importance for the careful<br />
calculation of appropriate times for rituals and sacrifices. The<br />
important treatises on Indian astronomy were the Gargi-samhita (c.<br />
AD 230), the Aryabhattiya of Aryabhata (AD 499), the Siddhantasekhara<br />
of Sripati, and the Siddhanta-Siromani of Bhaskara II (AD<br />
1114-1160).<br />
By the beginning of the Christian era, a great upsurge in the<br />
astronomical search was formalized in a number of methodical<br />
studies; many works of great importance, such as the five<br />
Siddhantas, of which the Surya Siddhanta is probably the best<br />
known, were compiled and later summarized by the sixth-century<br />
astronomer and mathematician Varaha-Mihira in his Panchasiddhantika<br />
(The Five Astronomical Systems), written about AD 550.<br />
In his outstanding work, the Brihat-samhita (The Great Compendium),<br />
he describes the motions and conjunctions of celestial<br />
bodies and their significance as omens.<br />
The classical period of ancient Indian astronomy is considered<br />
to have ended with Brahmagupta who wrote the Brahmasiddhanta,<br />
in AD 628, and the Khandakhadyaka, a practical treatise on<br />
astronomical calculations, in AD 664. Aryabhata's new epicyclic<br />
theory, and his postulates regarding the sphericity of the earth, its<br />
rotation upon its axis and revolution around the sun, as well as his<br />
formulae for the determination of the physical parameters of<br />
various celestial bodies (such as the diameters of the earth and the<br />
moon), and the prediction of eclipses and the correct length of the<br />
year by means of mathematical calculation, were significant<br />
achievements which anticipated and agree with the modern ideas.<br />
Aryabhata also gave the first fundamental definition of trigonometric<br />
functions and was responsible for pointing out the<br />
importance of zero.