Person: Lalla

Lalla was an Indian mathematician who wrote mainly on the application of mathematics to astronomy.

Lalla was an Indian astronomer and mathematician who followed the tradition of Aryabhata I.
Lalla's most famous work was entitled Shishyadhividdhidatantra.
In this volume Lalla examined topics such as: graphical representation; the celestial sphere; the principle of mean motion; the terrestrial sphere; motions and stations of the planets; geography; erroneous knowledge; instruments; and finally selected problems.
In Shishyadhividdhidatantra Lalla uses Sanskrit numerical symbols.
Lalla argues in his commentary, like many other Indian astronomers before him such as Varahamihira and Brahmagupta, that if the earth rotated then the speed would have to be such that one would have to ask how do the bees or birds flying in the sky come back to their nests?
Lalla misinterpreted some of Aryabhata I's statements about the rotating earth.
Lalla improved on these tables and he produced a set of corrections for the Moon's longitude.
One aspect of Aryabhata I's work which Lalla did follow was his value of π.
Lalla also wrote a commentary on Khandakhadyaka Ⓣ('edible bite' or 'morsel of food'), a work of Brahmagupta.
Lalla's commentary has not survived but there is another work on astrology by Lalla which has survived, namely the Jyotisaratnakosa.

Born about 720, India. Died about 790, India.

View full biography at MacTutor

Ancient Indian, Astronomy, Origin India

Thank you to the contributors under CC BY-SA 4.0!

O’Connor, John J; Robertson, Edmund F: MacTutor History of Mathematics Archive