Talk to Aryabhata
Astronomer who deduced a spinning earth at age 23
476–c. 550 CEIndia (Bihar)
Aryabhata was an astronomer and mathematician who composed the Aryabhatiya, a compact Sanskrit verse treatise, in 499 CE at Kusumapura (usually identified with Pataliputra, modern Patna), stating that he was 23 years old when 3,600 years of the Kali age had passed. His work assumes a decimal place-value system, gives the circumference-to-diameter ratio as 62,832 to 20,000 (about 3.1416) and calls it approximate, tabulates sine differences, solves indeterminate equations, explains lunar and solar eclipses by shadows rather than the demon Rahu, and holds that the earth rotates on its axis. Later astronomers such as Brahmagupta criticised several of his positions, while Bhaskara I and others wrote commentaries on his work.
Talk to Aryabhata out loud in the Yuga app.
Questions to ask
- Did you really invent zero?
- How did you know the earth spins?
- How did you calculate pi so accurately?
- What causes an eclipse, if not Rahu?
- Why did Brahmagupta disagree with you?
Which Aryabhata picks up
- 499Kusumapura (Pataliputra). Aged 23, having just composed the Aryabhatiya and defending its rotating earth and eclipse theory to sceptical scholars.
- 510Kusumapura. In his mid-thirties, teaching students astronomy and computation; tradition associates him with a centre of learning, sometimes linked to Nalanda (unverified).
- 530Kusumapura. In his fifties, an established authority whose system is spreading among astronomers and calendar-makers.
Questions about Aryabhata
- Who was Aryabhata?
- Aryabhata was an astronomer and mathematician who composed the Aryabhatiya, a compact Sanskrit verse treatise, in 499 CE at Kusumapura (usually identified with Pataliputra, modern Patna), stating that he was 23 years old when 3,600 years of the Kali age had passed. His work assumes a decimal place-value system, gives the circumference-to-diameter ratio as 62,832 to 20,000 (about 3.1416) and calls it approximate, tabulates sine differences, solves indeterminate equations, explains lunar and solar eclipses by shadows rather than the demon Rahu, and holds that the earth rotates on its axis. Later astronomers such as Brahmagupta criticised several of his positions, while Bhaskara I and others wrote commentaries on his work.
- Can you talk to Aryabhata with AI?
- Yes, in the Yuga app for iPhone and Android. You talk out loud with an AI recreation of Aryabhata, set in Kusumapura, 499. It draws on their own writing and well-sourced accounts of their life, and it can still get things wrong, so check anything important against the sources.
- Is that really Aryabhata's voice?
- No. No recording of their voice survives. Yuga's voice is designed from how people at the time described it, and every call is labelled an AI recreation.
- What did Aryabhata say about Value of pi?
- Add 4 to 100, multiply by 8, add 62,000: this is the approximate circumference of a circle of diameter 20,000 (giving about 3.1416), and he explicitly calls it approximate. Source: Aryabhatiya, Ganitapada, verse 10, 499 CE.
- What did Aryabhata say about Rotation of the earth?
- Just as a man in a moving boat sees stationary objects moving backwards, the stationary stars appear to move westward because of the earth's motion. Source: Aryabhatiya, Golapada, verse 9, 499 CE.
- What did Aryabhata say about Eclipses?
- The moon covers the sun, and the great shadow of the earth covers the moon, causing eclipses; he computes their timing and extent. Source: Aryabhatiya, Golapada, verses 37–48, 499 CE.
How Aryabhata talks
Concise to the point of compression, like his verses: he states a rule in one line and expects the listener to work out the rest, then relents and walks through an example. Uses numbers constantly. Gentle mockery of explanations that rely on demons or myth. Pleased by elegant shortcuts.