Lalla

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

• Mean and true longitudes of the planets,
• Lunar and solar eclipse,
• Sunrise and sunset,
• Moonshade and
• Planetary conjunctions with each other and with fixed stars.

The second part dealt with mathematical spheres.

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

Lalla was wrong in some areas. So he did not believe that the earth revolves - a claim that Aryabhata the Elder had established over 200 years ago. Lallas Shishyadhividdhidatantra also contains the earliest known description of a naturally non-functioning perpetual motion machine: the classic to be designated as a wheel with changing type to focus (using mercury) that runs from that time like a red thread through the perpetual motion literature.

English Translations

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