India’s first indigenously built satellite, the Aryabhata, that was launched on April 19, 1975 was named after the famous 5th century Indian astronomer and mathematician Aryabhata.
The satellite’s name was so chosen because Aryabhata, whose timeline spanned 476-550 CE, was the first of the major mathematician-astronomers of the classical age of Indian mathematics and Indian astronomy. Among many of his achievements — both real and attributed to him as his legend grew over the centuries — the most stunning is his exact calculation of the earth’s circumference (with less than 1% error) a thousand years before the Western world calculated it right.
Where Did He Live?
Aryabhata’s timeline makes him the resident of the Gupta Empire, which is widely considered the Golden Age of Indian History, when arts and sciences flourished.
We know about his timeline because in one of his famous books, the Aryabhatiya, he mentions that he was 23 years old in the 3,600th year of Kali Yuga, which corresponds to 499 CE, implying that he was born in 476 CE. He also hints that he was a resident of Kusumpura (which was the name of Pataliputra, or present day Patna), through the phrase: Kusumapura abhyaarcitam gnaanam, which loosely translated means knowledge respected in Kusumpura.
Though less accepted, there has been another hypothesis on the place of his origin. Some scholars believe he hailed from present-day Kodungallur in Kerala because of the reference to a city of stone being Aryabhata’s place of birth in Aryabhatiyabhasya, the commentary on Aryabhatiya by 7th century mathematician and astronomer Bhaskara I. The ancient name of Kodungallur meant ‘a city of hard stones’.
At any rate, Aryabhata definitely lived in Kusumpura for advanced studies at the Nalanda University. This is known from some contemporary Hindu and Buddhist texts. Besides, Bhaskara I’s commentary on Aryabhatiya mentions that the legendary mathematician-astronomer had an astronomical observatory and was the head of a university in Kusumpura, in clear reference to the Nalanda University of Pataliputra that flourished at that time.
Nalanda, founded in the 5th century, was a revered Buddhist monastery (Mahavihara) and a world-renown university in the ancient kingdom of Magadha. At its peak, it attracted scholars and travellers from beyond the subcontinent, such as from Tibet, China, Korea and Central Asia. Nalanda’s Buddhist monks were hungry for scientific knowledge and took a keen interest in the works of Greek and Mesopotamian scholars who had made advances in astronomy, mathematics, physics and related subjects. The intellectual churn at Nalanda made it one of the most sought after centres of learning in this part of the world.
Aryabhata’s Works
Aryabhata wrote several books and treatises on mathematics and astronomy, some of which, however, have been lost forever. We know of those lost works through their mention in the works of later day scholars who would have been inspired by Aryabhata’s works.
However, Aryabhatiya, which has survived to the modern times, is the most well-known. Besides surviving as a book itself, this compendium of mathematics and astronomy has been referred to in Indian mathematical literature throughout history.
It’s interesting to note that the title Aryabhatiya may not have been given to this treatise by its author himself; it was thus named by later day scholars. It has also been referred to as Ashmakatantra (Treatise by the Ashmaka) or Aryashatasashta (or Aryabhata’s 108), as it comprises 108 verses.
A detailed study of Aryabhatiya and commentaries on his lost works all imply one thing with certainty — that this ancient Indian scholar was not just a genius but a man worthy of study even 15 centuries later, and at a time when the lasting value of many surprising and great inventions does not go beyond a human being’s lifetime.
Aryabhata, India’s first indigenous
satellite launched on April 19, 1975
The text contains 108 verses and 13 introductory verses. It is divided into four chapters, such as:
1. Gitikapada, dealing with large units of time such as kalpa, manvantra and yuga.
2. Ganitapada, dealing with mensuration, arithmetic and geometric progressions
3. Kalakriyapada, dealing with different units of time and determining the positions of planets
4. Golapada, dealing with geometric and trigonometric aspects of the celestial sphere
The Aryabhatiya was a text meant for serious scholars as it was quite a complex. It could be understood only with the help of commentaries or bhashyas, and these commentaries continued to be written for centuries.
Aryabhata Siddhanta was another of his works that is mentioned frequently by later day scholars and commentators. However, it is lost and what it contained can only be gleaned from its references in later day texts. What makes it important is the fact that this book, unlike the author’s own Aryabhatiya, propounded midnight, and not the sunrise, as the starting hour of each day.
Legend Unparalleled
So little is known about Aryabhata, yet he continues to stand tall among astronomers and mathematicians even 15 centuries after his time. What makes him such an unparalleled legend?
It his work in the field of astronomy and mathematics, unprecedented those many years ago, that has made him a scholar par excellence even in the 21st century.
Modern estimates suggest that Aryabhata calculated the earth’s circumference as 39,968 km, extremely close to the modern calculation of 40,074 km. It is incredible considering that the ancient scholar did not have any of the modern scientific aids.
He calculated an accurate table of sines, considered the first sine table constructed in the history of mathematics. It is not a table in the modern sense, comprising values in rows and columns, but it is a computation of the half-chords of certain set of arcs of a circle. It served as a standard table in ancient India and later scholars worked upon it and improved it further. It eventually resulted in the discovery of the power series expansions of the sine and cosine functions by Madhava of Sangamagrama (c. 1350 – 1425 CE), the founder of the Kerala school of astronomy and mathematics.
A hypothesis states that Aryabhata’s table may have been inspired by earlier Greek works but there is no extant Greek work to prove the point.
As is evident in the first chapter of Aryabhatiya, Aryabhata propounded that the earth rotated about its axis daily and the apparent movement of the stars was due to the relative motion caused by the earth’s rotation and not due to the rotation of the sky, which was widely believed for many centuries thereafter.
He also stated that sun was the only source of light in the universe; not just other planets but even stars reflected the light of the sun.
Aryabhata also worked on the approximation of pi and accurately calculated it to three decimal places as 3.141. Though he did not use zero in his mathematical verses and calculations, its use was implicit in his place-value system.
Aryabhata’s work was of great influence in the Indian astronomical tradition and influenced several neighbouring cultures through translations. The Arabic translation during the Islamic Golden Age (c. 820 CE) was particularly influential.
