Lalla ( 720–790 CE) was an Indian

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...

astronomer An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, moons, comets and galaxies – in either o ...

, and

astrologer Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Di ...

who belonged to a family of astronomers. Lalla was the son of Trivikrama Bhatta and the grandson of Śâmba."Lalla." Complete Dictionary of Scientific Biography. He lived in central India, possibly in the

Lāṭa Lata (IAST: Lāṭa) was a historical region of India, located in the southern part of the present-day Gujarat state. Location and extent ''Shakti-Sangam-Tantra'', a Shakt sampradaya text composed before 7th century CE, states that Lata wa ...

region in modern south

Gujarat Gujarat (, ) is a state along the western coast of India. Its coastline of about is the longest in the country, most of which lies on the Kathiawar peninsula. Gujarat is the fifth-largest Indian state by area, covering some ; and the nin ...

. Lalla was known as being one of the leading Indian astronomers of the eighth century. Only two of his works are currently thought to be extant.Bracher, Katherine His best-known work is the ''Śiṣyadhīvṛddhidatantra'' ("Treatise which expands the intellect of students"). This text is one of the first major Sanskrit astronomical texts known from the period following the 7th-century works of

Brahmagupta Brahmagupta ( – ) was an Indian mathematician and astronomer. He is the author of two early works on mathematics and astronomy: the '' Brāhmasphuṭasiddhānta'' (BSS, "correctly established doctrine of Brahma", dated 628), a theoretical tr ...

and Bhāskara I. It generally treats the same astronomical subject matter and demonstrates the same computational techniques as earlier authors, although there are some significant innovations, such that Lalla’s treatise offers a compromise between the rival astronomical schools of his predecessors, Āryabhaṭa I and Brahmagupta. It is within the ''Śiṣyadhīvṛddhidatantra'' that the earliest known description of ''

perpetual motion Perpetual motion is the motion of bodies that continues forever in an unperturbed system. A perpetual motion machine is a hypothetical machine that can do work infinitely without an external energy source. This kind of machine is impossible, a ...

'' is described. The other extant work by Lalla is the ''Jyotiṣaratnakośa'' ("Treasury of Jewels"), a treatise on catarchic astrology. This work is one of the earliest known Sanskrit astrological works for determining auspicious and inauspicious times. No edition of this text has ever been published while the known manuscripts are incomplete. In his work, Lalla drew on his predecessors

, and Bhāskara I. In turn, he influenced later generations of astronomers, including

Āryabhaṭa II Āryabhaṭa (c. 920 – c. 1000) was an Indian mathematician and astronomer, and the author of the ''Maha-Siddhanta Āryabhaṭa (c. 920 – c. 1000) was an Indian mathematician and astronomer An astronomer is a scientist in the f ...

Śrīpati Śrīpati (1019–1066) was an Indian astronomer,astrologer and mathematician, the author of '' Dhikotidakarana'' (written in 1039), a work of twenty verses on solar and lunar eclipses; '' Dhruvamanasa'' (written in 1056), a work of 105 verses o ...

, Vaṭeśvara, and

Bhāskara II Bhāskara II (c. 1114–1185), also known as Bhāskarāchārya ("Bhāskara, the teacher"), and as Bhāskara II to avoid confusion with Bhāskara I, was an Indian mathematician and astronomer. From verses, in his main work, Siddhānta Shirom ...

(who later wrote a commentary on the ''Śiṣyadhīvṛddhidatantra''). He followed the Āryapakṣa or the school of

Āryabhaṭa Aryabhata ( ISO: ) or Aryabhata I (476–550 CE) was an Indian mathematician and astronomer of the classical age of Indian mathematics and Indian astronomy. He flourished in the Gupta Era and produced works such as the ''Aryabhatiya'' (whi ...

(continued by Bhāskara I), but divided the ''mahāyuga'' in the traditional way, following the Brāhmapakṣa school. of

Works

* ''Śiṣyadhīvṛddhidatantra'': The most extensive extant exposition of the views of the Āryapaksa school. It contains twenty-two chapters divided into two books: : I. On the Computation of the Positions of the Planets # On the mean longitudes of the planets. # On the true longitudes of the planets. # On the three problems involving diurnal motion. # On lunar eclipses. # On solar eclipses. # On the syzygies. # On the heliacal settings and risings of the planets. # On the shadow of the moon. # On the lunar crescent. # On planetary conjunctions. # On conjunctions of the planets with the stars. # On the pātas of the sun and moon. # Conclusion. : II. On the Sphere # On graphical representations. # On the construction of the celestial sphere. # On the principles of mean motion. # On the terrestrial sphere. # On the motions and stations of the planets. # On geography. # On erroneous knowledge. # On instruments. # On certain (selected) problems" * ''Jyotiṣaratnakośa'': A popular book on astronomy in IndiaMacTutor biography * A commentary on

's ''Khandakhadyaka'', now lost

Notes

References

* * K. V. Sarma. "Lalla." ''Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures'', ed.

Helaine Selin Helaine Selin (born 1946) is an American librarian, historian of science, author and the editor of several bestselling books. Career Selin attended Binghamton University, where she earned her bachelor's degree. She received her MLS from SUNY A ...

, Dordrecht: Kluwer Academic Publishers, 1997, p. 508. * *
Lalla
" Complete Dictionary of Scientific Biography. Vol. 7. Detroit: Charles Scribner's Sons, 2008. 582-583. Gale Virtual Reference Library. Web. 3 June 2013. *Bracher, Katherine
The Biographical Encyclopedia Of Astronomers
lectronic Resource/ Edited By K. Bracher ... t Al. n.p.: New York ; London : Springer, 2006., 2006. UNIV OF OKLAHOMA LIBRARIES's Catalog. Web. 6 June 2013. {{Authority control 8th-century Indian astronomers 8th-century Indian mathematicians 720 births 790 deaths Scholars from Gujarat