Aryabhata – Contributions, Inventions, and Legacy of India’s First Astronomer

Aryabhata was one of the greatest mathematicians and astronomers of ancient India. He is also called Aryabhata I or Aryabhata the Elder, to distinguish him from another scholar of the same name who was born five centuries later. Every midnight, the date changes. You will be surprised to know that Aryabhata was one of the first scientists to consider midnight as the start of each day. Though he lived more than 1,500 years ago, his discoveries continue to amaze scientists even today.

Origin Story of Aryabhata

Aryabhata was born in 476 CE, either in Ashmaka (an area between Maharashtra and Telengana today) or in Kusumapura or Pataliputra, which was near modern-day Patna in Bihar. It is known that Aryabhata lived in Pataliputra for a long time, pursuing his advanced studies. This period was the Gupta Empire, when Pataliputra was a famous centre of learning and culture, and many scholars lived and worked there.

Aryabhata is believed to have been the head (kulapati) of an educational institution in Pataliputra. The renowned, ancient centre of learning—Nalanda University—was close to this place, and it is said Aryabhata may have been associated with it.

Scholarly Contributions of Aryabhata

1. Aryabhatiya and Aryabhatasiddhanta

   Aryabhata authored several significant texts, but two of his most known works are the Aryabhatiya and the now-lost Aryabhatasiddhanta.

   
   

(i) Aryabhatiya: Aryabhata's most celebrated work, Aryabhatiya, was

composed around 499 CE. This book includes both mathematics and astronomy and is written in verse style. It is structured into four sections: Gitikapada, Ganita, Kalakriyapada, and Golapada.

• Gitikapada: This introductory section presents the fundamental mathematical concepts required for astronomical calculations. It builds the foundation for understanding time cycles and planetary motions.

• Ganita: In this section, Aryabhata discusses arithmetic and algebraic topics, including operations with numbers, fractions, quadratic equations, the place value system (a noteworthy early use of zero), and elementary geometry.

• Kalakriyapada: This portion is devoted to time calculations. Aryabhata explains methods for computing planetary positions and time intervals based on astronomical observations, including techniques for calendar calculations.

• Golapada: The final section explores the celestial sphere. Aryabhata presents a model of a spherical Earth, explains the causes of day and night, and offers a scientific interpretation of eclipses. His explanations reflect an advanced understanding of planetary science for his time.

  
  

(ii) Aryabhatasiddhanta: This is another text credited to Aryabhata, but is now lost. We know that he had created this work because it is mentioned in the works of later scholars like Varahamihira and Bhaskara I. Scholars believe it contained detailed astronomical models and calculations, possibly presenting methods that were different from those found in the Aryabhatiya. It is believed that the Aryabhatasiddhanta served as a more technical astronomical manual, perhaps intended for use in royal observatories.

2. Achievements in mathematics & astronomy

Aryabhata used a place value system in his calculations, which was a significant advancement in mathematics. He named the first 10 decimal places and used the decimal system to find cube and square roots. In mathematics, the circumference of a circle is given by multiplying the diameter with a constant number denoted by the Greek letter π (called pi). An astonishing accomplishment of Aryabhata was that he provided an approximation of π as 3.1416, which is remarkably close to the actual value.

Aryabhata and approximation of π

Do you know? The first known efforts to find the value of pi came from Indian rishis who built fire altars for yajnas. Over 2,500 years ago, they wrote down geometric rules for measuring circles using ropes. These rules are found in the Shulba Sutras, which are part of the Kalpa Vedanga, one of the six ancient texts that support the Vedas.

Today, we learn about the solar system from childhood, but in ancient times, it was not easy for people to understand deeply about the space and celestial bodies. Aryabhata proposed that the Earth rotates on its axis daily, explaining the apparent movement of stars, which we see in relation to other bodies. He scientifically explained solar and lunar eclipses as the result of shadows cast by the Earth and the Moon, moving away from the mythological explanations involving Rahu and Ketu. Aryabhata calculated the duration of rotation of the Earth as 23 hours, 56 minutes, and 4.1 seconds, which is very close to the modern value.

Legacy and Recognition of Aryabhata

Aryabhata passed away in 550 CE. His ideas influenced scholars not just in India but also in other parts of the world. His work was translated into Arabic, and Arabic scholars referred to him as “Arjabahr”. Later, his ideas reached Europe through these translations. Aryabhata believed that understanding the universe was a path to understanding truth. He said that science and spiritual learning go together and that one should use logic and reasoning.

Aryabhata laid the foundation for astronomy in India, and later astronomers like Varahamihira, Brahmagupta, and Bhaskara I built on his work. Educational and research institutions like Aryabhatta Research Institute of Observational Sciences (ARIES) in Nainital, Aryabhatta Knowledge University (AKU) in Patna and the Aryabhatta College in New Delhi are named after him. In 1975, the Indian Space Research Organisation named its first satellite Aryabhata. It is only fitting for such a great astronomer that a crater on the Moon has been named Aryabhata by the International Astronomical Union in honour of his legacy.