Lalla (astronomer)

This article is about the astronomer Lalla. For the Tasmanian Lalla Rookh see Truganini ; for other meanings see Lalla Rookh .

Lalla (* around 720 ; † around 790 ) was an Indian astronomer and mathematician. His most famous work is Shishyadhividdhidatantra . The first part of this work deals with, for example, 13 chapters

• mean and true longitudes of the planets ,
• Lunar and solar eclipses ,
• Sunrise and sunset,
• Moon shadow and
• Planetary conjunctions with each other and with fixed stars .

The second part dealt with mathematical spheres .

Another work is Jyotisaratnakosa . This book was the most popular astronomy book in India for 300 years. Another work is considered lost.

Lalla was wrong in some areas. So he did not believe that the earth was rotating - a claim made by Aryabhata the Elder over 200 years earlier. Lalla's Shishyadhividdhidatantra also contains the oldest known description of a (non-functioning) perpetual motion machine : the classic wheel with a changing center of gravity (using mercury ), which has been a common thread through the perpetual motion machine literature since then.

English translations

• Bina Chatterjee: Sisyadhivrddhidatantra of Lalla (critical edition with Commentary of Mallikarjuna Suri). 1969-1971. Indian National Science Academy, 1981.
• Bina Chatterjee: Sisyadhivrddhidatantra of Lalla (English translation with mathematical notes). 1969-1971. Indian National Science Academy, 1981.

Web links

• John J. O'Connor, Edmund F. Robertson :  Lalla (astronomer). In: MacTutor History of Mathematics archive .