Text · Sanskrit astronomical treatise
Aryabhatiya
/aːrjɐbʱɐʈiːjɐ/
Also known as Āryabhaṭīya, Āryabhaṭīyaṃ, Aryabhatiyam, Ashmakatantra, Arya-shatas-ashta
Aryabhata's only surviving work: 108 verses and 13 introductory ones, in four sections on cycles of time and a sine table, mathematics, the reckoning of time, and the celestial sphere. It has the Earth turning on its axis, explains eclipses, says the Moon and planets shine by reflected sunlight, and puts π at 62832/20000. Translated into Arabic around 800 and studied by al-Khwarizmi, it left English the word sine.
- Date
- 499–510
- Function
- Text & inscription
- Confidence
- Established / referenced
Worth knowing
Its numbers are written in an alphabetic code in which consonants give the digits and vowels mark their place value, so astronomical constants could be set in verse. Aryabhata's methods are still used to fix the Panchangam, the Hindu calendar.
It is dated from Aryabhata's own statement to 499 CE, which need not be the year of writing; Roger Billard puts its composition around 510 CE. B. L. van der Waerden read a heliocentric model beneath its geocentric one, a view Noel Swerdlow rejected as contradicting the text.
Connections (4)
- Associated withAryabhata
The Aryabhatiya is Aryabhata's only surviving work and the source of most of what is known about him. His statement in it that he was 23 years old when 3,600 years of the Kali Yuga had passed corresponds to 499 CE and gives his birth year as 476. He called himself a native of Kusumapura, which Bhaskara I identified as Pataliputra. Aryabhata may not have named the book at all; Bhaskara I calls it the Ashmakatantra.
- Commented onNilakantha Somayaji
The Aryabhatiya was probably meant to be studied with a tutor, and its history is a chain of commentaries: twelve named commentators are known, from Prabhakara (c. 525) and Aryabhata's disciple Bhaskara I (c. 629) to Telugu writers of the nineteenth century. Nilakantha Somayaji of the Kerala school wrote his Aryabhatiya Bhashya in 1465, nearly a thousand years after the text, which shows it was still a working basis for astronomy in fifteenth-century Kerala.
- TransmissionBaghdad
An anonymous Arabic translation of the Aryabhatiya, the Zij al-Arjabhar, appeared around 800, and around 820 it was studied by al-Khwarizmi, then astronomer and head of the library at the House of Wisdom in Baghdad. Aryabhata's jya, the half-chord, became Arabic jiba, was misread as jaib, a fold, and was rendered by Gerard of Cremona as Latin sinus, the source of sine. Yaqub ibn Tariq's diameter of the Earth also appears to derive from it.
- Historical linkThe decimal place-value numerals
The Aryabhatiya writes numbers in an alphabetic code in which consonants supply the digits and vowels mark their place value, a positional system expressed in syllables rather than in nine figures and a zero. Its Arabic translation was studied around 820 by al-Khwarizmi, whose book on calculating with Hindu numerals, known in Latin as Algoritmi de numero Indorum, carried the decimal place-value digits into Europe from the twelfth century and gave English the word algorithm.
Sources
Wikipedia, "Aryabhatiya"; "Aryabhata". Walter Eugene Clark (tr.), The Āryabhaṭīya of Āryabhaṭa (1930); Hugh Thurston, Early Astronomy (1996).
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