Aryabhatta

Aryabhata was the first great Indian mathematician and astronomer. His two most famous works are the Aryabhatiya and Arya-Siddhanta. Aryabhatiya is a compendium of mathematics and astronomy. Arya-Siddhanta is his work on astronomical computations. The place-value system and the knowledge of zero were clearly in place in his work. Aryabhata concluded that the value of Pi is irrational, and his calculated value of 3.1416 is accurate to five significant figures. It is quite an insight because the irrationality of Pi was proved in Europe only in 1761.

In astronomy, Aryabhata believed that the earth rotates about its axis. Moon and planets shine by reflected sunlight. His computation of the earth’s circumference was only 0.2% smaller than today’s known value and his calculation of slide-real rotation and slide-real year were considered to be the most accurate of the period.

India’s first satellite “Aryabhata” and the lunar crater “Aryabhata”, and Aryabhata Research Institute of Observational Sciences near Nainital are named in his honor.