
Aryabhata Aryabhata was
born in 476 A.D. in Ashmaka, lived in Kusumapura and died in 629 A.D. He is called the first of
the great astronomers of the classical age of Aryabhata His book, the Āryabhatīya, presented astronomical and
mathematical theories in which the Earth was taken to be spinning on its axis
and the periods of the planets were given with respect to the sun. He affirmed the theory of the heliocentrism. In this book,
the day was reckoned from one sunrise to the next, whereas in his Āryabhatasiddhānta he took the day from one
midnight to another. He stated that 1,582,237,500 rotations of the Earth are
equal to 57,753,336 lunar orbits. This is an extremely accurate ratio of a fundamental
astronomical ratio (1,582,237,500/57,753,336 = 27.3964693572), and is perhaps
the oldest astronomical constant calculated to such accuracy. Showing the lowercase Greek letter equivalent to “p” in the Roman alphabet Aryabhata also
gave an accurate approximation for pi, the most accurate among those of the
ancients. He does not explain how he found this accurate value, but it could be
an approximation to half the perimeter of a regular polygon of 256 sides
inscribed in the unit circle. In the Aryabhatiya, he
wrote: "Add four to one
hundred, multiply by eight and then add sixtytwo thousand. The result is
approximately the circumference of a circle of diameter twenty thousand. By
this rule the relation of the circumference to diameter is given." In other words,
π ≈ 62832/20000 = 3.1416, correct to four roundedoff decimal
places. Reference
for the contents above and further information of Aryabhata’s
live: http://www.jqjacobs.net/astro/aryabhata.html http://www.albertson.edu/math/History/skuek/Classical/disc1.htm http://en.wikipedia.org/wiki/Aryabhata Ziegenbalg J.: Algorithmen, von Hammurapi bis Gödel; Spektrum Akademischer Verlag 
