|
Kelallur Nilakantha Somayaji (1444–1544) (also referred to as Kelallur Comatiri) was a major mathematician and astronomer of the Kerala school of astronomy and mathematics. One of his most influential works was the comprehensive astronomical treatise ''Tantrasamgraha'' completed in 1501. He had also composed an elaborate commentary on Aryabhatiya called the ''Aryabhatiya Bhasya''. In this Bhasya, Nilakantha had discussed infinite series expansions of trigonometric functions and problems of algebra and spherical geometry. ''Grahapareeksakrama'' is a manual on making observations in astronomy based on instruments of the time. ==Biographical details== Nilakantha Somayaji was one of the very few authors of the scholarly traditions of India who had cared to record details about his own life and times. So fortunately a few accurate particulars about Nilakantha Somayaji are known.〔''Tantrasamgraha'', ed. K.V. Sarma, trans. V. S. Narasimhan in the Indian Journal of History of Science, issue starting Vol. 33, No. 1 of March 1998〕 In one of his works titled ''Siddhanta-star'' and also in his own commentary on ''Siddhanta-darpana'', Nilakantha Somayaji has stated that he was born on Kali-day 1,660,181 which works out to 14 th June 1444 CE. A contemporary reference to Nilakantha Somayaji in a Malayalam work on astrology implies that Somayaji lived to a ripe old age even to become a centenarian. Sankara Variar, a pupil of Nilakantha Somayaji, in his commentary on Tantrasamgraha titled ''Tantrasamgraha-vyakhya'', points out that the first and last verses of Tantrasamgraha contain chronograms specifying the Kali-days of the commencement (1,680,548) and of completion (1,680,553) of Somayaji's magnum opus Tantrasamgraha. Both these days occur in 1500 CE. In Aryabhatiya-bhashya, Nilakantha Somayaji has stated that he was the son of Jatavedas and he had a brother named Sankara. Somayaji has further stated that he was a Bhatta belonging to the Gargya-gotra and was a follower of Asvalayana-sutra of Rigveda. References in his own ''Laghuramayana'' indicate that Nilakantha Somayaji was a member of the Kelallur family (Sanskritised as Kerala-sad-grama) residing at Kundagrama, now known as Trikkandiyur in modern Tirur, Kerala. His wife was named Arya and he had two sons Rama and Dakshinamurti. Nilakantha Somayaji studied vedanta and some aspects of astronomy under one Ravi. However, It was Damodara, son of Kerala-drgganita author Paramesvara, who initiated him into the science of astronomy and instructed him in the basic principles of mathematical computations. The great Malayalam poet Thunchaththu Ramanujan Ezhuthachan is said to have been a student of Nilakantha Somayaji. The epithet ''Somayaji'' is a title assigned to or assumed by a Namputiri who has performed the vedic ritual of ''Somayajna''. So it could be surmised that Nilakantha Somayaji had also performed a ''Somayajna'' ritual and assumed the title of a ''Somayaji'' in later life. In colloquial Malayalam usage the word Somayaji has been corrupted to Comatiri. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Nilakantha Somayaji」の詳細全文を読む スポンサード リンク
|