Aryabhata: The man from Bihar who gave world the concept of modern day Mathematics

By Prachi Mishra

Aryabhata was one of the first Indian mathematicians and astronomers belonging to the classical age. A pioneer in the field of mathematics, he went on to discover the digit 0.

He was born in 476 BC in Tarenaga, a town in Bihar, India. However, some sources mention that he belonged to Kerala. He completed his education at the well-known ancient University of Nalanda, which is located near Kusumapura in the present Indian state of Bihar. Since the University had an observatory in its premises, it is conjectured that Aryabhata was the principal of the institute as well.

Work in the field of Mathematics

Aryabhata wrote the scholarly work Aryabhattiya at a young age of 23, which is a summary of mathematics of his time. The work is divided into four sections. In the first section, the method of denoting big decimal numbers by alphabets has been described. The second section comprises of questions from topics of modern day Mathematics, such as number theory, geometry, trigonometry and Beejganita (algebra). The remaining two sections are on astronomy.

The discovery of zero enabled him to find out the exact distance between the earth and the moon. It also exposed a new feature of negative numerals.

For the first time, he gave the approximate value of pi as 3.1416. He arrived at this value by calculating the approximate circumference of a circle having a diameter of 20,000 units, which came out to be 62,832. He also gave the correct formula for calculating the area of a triangle.

He was also the first mathematician to give what later came to be known as the tables of Sines. The birth of trigonometry was influenced by his definitions of sine (jya), cosine (kojya), versine (utkrama-jya), and inverse sine (otkram jya).

Contribution to Astronomy

The last two sections of Aryabhattiya deal with astronomy.

Much before Copernicus enlightened the West with the discovery that sun is at the centre of solar system and all the planets including earth revolve around it, Aryabhata made this discovery by adopting the heliocentric theory. He disregarded the popular belief that earth is stationary and stated the theory that earth is round and rotates on its own axis, which causes the occurrence of day and night.

Aryabhatta challenged various prevalent superstitious beliefs and gave scientific explanations for many natural phenomena. He correctly stated that the moon and other planets do not have light of their own and shine because of the reflection of the light of the sun.

There was a popular Hindu belief that solar and lunar eclipses occurred because Rahu and Ketu (demon's head) gobbled the sun and the moon. Aryabhata demolished this myth by proposing the theory that eclipses occur due to the shadows casted by the earth and the moon.

Due to his immense contribution towards developing mathematical and astronomical studies, the first satellite sent into orbit by India has been named after Aryabhata.