Aryabhatta and the Brahma School of Astronomy: Some historians believe that Aryabhatta was the first great scientist, astronomer and mathematician of ancient India. Earlier, mathematical or astronomical projections needed for religious ceremonies and rituals were deduced from the Vedas or Sulabh Sutras, which were believed to have been contributed by great sages and were essentially functional in nature.
Aryabhatta also approached science initially from a religious angle as he was a great devotee of Lord Brahma (The creator of the Universe according to Hindu scriptures). His motivation was that it was necessary to investigate the truth about Nature in order to know the truth about its Creator. Astronomy was therefore his first love. But since astronomical principles could be worked out only through mathematics it was important to study that subject too. His devotion to Brahma was such that he acknowledges the grace of Brahma in one of the closing shlokas (verses) of his book, prompting many people to believe that 'Aryabhatia' was actually revealed to him by Lord Brahma.
The Brahma School of Astronomy was the most ancient school of Hindu astronomy, and Aryabhata probably felt drawn to it because the astronomers of Kusumpura where he lived were followers of that school. Pandurangaswamy, Latadeva and Nisenku are some of the astronomers who studied astronomy from him. Astronomical Findings: Aryabhatta was the first Indian scientist to record his planetary observations and then consolidate it with other available mathematical and astronomical results scattered among the various scriptures, into a textbook for astronomy. Unlike the Greek mathematicians he did not prove his results but presented them in compact form in the Indian tradition. In just fifty shlokas, he explained the motion of the sun, the moon and the planets in the celestial sphere. He also explained the methods of finding the length of the earth's shadow and related it to the lunar eclipse.
Some of Aryabhatta's theories, such as his notion about a spherical earth, movement of the earth around the sun, the positions of the different planets were brilliant and precise concepts and are still referred to by modern day mathematicians and astronomers. Aryabhatta produced three major works on astronomy - Aryabhatiya, Aryabhatta-Siddhanta, and Surya-Siddhanta-Prakara, of which the first is the best known. The Aryabhatiya deals both with astronomy and mathematics. He wrote the first edition when he was only 23 and later modified it when he was older. The Aryabhatiya was partly based on available literature which had been corrected and revised to rectify all errors, and the rest consisted of his own astronomical paradigms which were based on his own observations.
Aryabhatta started a new branch of astronomy, which came to be known as the Aryabhatta School. Bhaskara I was the most illustrious disciple of this school. At an age when telescopes and other astronomical instruments had not been invented, Aryabhatta came up with innovative technique to calculate astronomical positions and movements, made accurate predictions about the occurrence and duration of eclipses and worked out geometrical and theoretical method for constructing sine tables. He was probably the first mathematician to prepare a table of sine differences.Mathematical Findings: Aryabhata dealt with mathematics in thirty-three slokas (verses) of his book. He covered a wide range from geometrical figures and their properties, interest, series, simultaneous and quadratic equations, linear indeterminate equations, square roots, cube roots, method of constructing sine table etc
Aryabhatta also introduced a new system of calculating astronomical time. Unlike the Greeks he did not believe in the theory of creation and destruction of the world. He believed that time was a continuous process without beginning and end.The beginning of Yuga and kalpa, had nothing to do with terrestrial occurrence, he believed. He based his theory entirely on astronomical phenomena, which consisted of -1 day of Brahma of Kalpa = 14 manus; 1 manu = 72 Yugas; 1 Yuga = 43,20,000 years. Aryabhatta's critical work in arithmetic came in the area of performing calculations according to decimal place - value numeration. He was, in fact, the first Indian mathematician to adopt the decimal system and to write formally about it in book.
Aryabhatta was probably born around April 13, 476 AD at Kusumpura (some have identified it with modern Patna) on the River Ganges. During this period, Indian civilization had reached an intellectual peak with great scholars and artists gracing almost all branches of arts, science and literature. No authentic information is available about the chronological history of Aryabhatta’s life, such as his parentage, education and other aspects of personal life. It is only from the writings of Bhaskara I, who was one of his students, that it is known that Aryabhatta took up the profession of a teacher. He earned great fame as a teacher of astronomy and was referred to as Acharya (Professor) and Sarva- Siddhanta Guru by Bhaskara I. He was also called the Kulapati, which is usually a designation given to the Head of a University. From this it was assumed that Aryabhatta was probably the Head of the University of Nalanda which was one of the premier learning centres of India at that time.