imported>Florian Blaschke: sp

2021-07-15T19:46:04Z

New page

{{Short description|Indian mathametician/astronomer (1444–1544)}}
{{Use dmy dates|date=August 2019}}
{{Use Indian English|date=August 2019}}
{{ infobox person
| name = Nilakantha Somayaji
| caption =
| birth_name =
| birth_date = 14 June 1444
| birth_place = [[Tirur]], [[Kerala]]
| death_date = 1544{{citation needed|date=February 2020}}
| death_place =
| resting_place_coordinates = 
| nationality = Indian
| citizenship =
| other_names = Kelallur Comatiri
| known_for = Authorship of [[Tantrasamgraha]]
| education =
| alma_mater =
| employer =
| notable works = Golasara, Candrachayaganita, Aryabhatiya-bhashya, [[Tantrasamgraha]]
| occupation = Astronomer-mathematician
| years_active =
| title = Somayaji
| boards =
| spouse = Arya
| partner =
| children = Rama, Dakshinamurti
| parents = Jatavedan (father)
| relations =
}}

'''Keļallur Nilakantha Somayaji''' (14 June 1444 – 1544), also referred to as '''Keļallur Comatiri''',<ref>{{cite journal|last=K.D. Swaminathan|date=1972|title=Jyotisa in Kerala|journal=Indian Journal of History of Science|volume=8|issue=1 & 2|pages=28–36|url=http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005b62_28.pdf|access-date=3 February 2010}}</ref> was a major [[Indian mathematics|mathematician]] and [[Indian astronomy|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]]. ''Grahapariksakrama'' is a manual on making observations in astronomy based on instruments of the time. Known popularly as '''Kelallur Chomaathiri''', he is considered an equal to [[Vatasseri Parameshwaran Nambudiri]].

==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.<ref name="text">{{cite web|url=http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_2/20005a5d_s1.pdf|title=Tantrasamgraha with English translation|last=[[K.V. Sarma]] (editor)|others=Translated by V.S. Narasimhan|publisher=Indian National Academy of Science|pages=48|language=sa, en|access-date=17 January 2010|url-status=dead|archive-url=https://web.archive.org/web/20120309014402/http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_2/20005a5d_s1.pdf|archive-date=9 March 2012}}</ref><ref>''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</ref>

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 yuga|Kali-day]] 1,660,181 which works out to 14 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 yuga|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 [[Shakha|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]]''.<ref>{{cite web|url=http://www.namboothiri.com/articles/yajnam.htm|title=Yaagam (Yajnam)|last=P. Vinod Bhattathiripad|author2=K.D. Nambudripad |date=3 May 2007|publisher=Namboothiri Websites Trust|access-date=4 February 2010}}</ref> 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.

==Nilakantha Somayaji as a polymath ==
Nilakantha's writings substantiate his knowledge of several branches of Indian philosophy and culture. It is said that he could refer to a Mimamsa authority to establish his view-point in a debate and with equal felicity apply a grammatical dictum to the same purpose.
In his writings he refers to a Mimamsa authority, quotes extensively from Pingala's chandas-sutra, scriptures, Dharmasastras, Bhagavata and Vishnupurana also. Sundararaja, a contemporary Tamil astronomer, refers to Nilakantha as sad-darshani-parangata, one who had mastered the six systems of Indian philosophy.<ref name="text"/>

==Astronomy==
In his ''[[Tantrasangraha]]'', Nilakantha revised [[Aryabhata]]'s model for the planets [[Mercury (planet)|Mercury]] and [[Venus]]. His equation of the [[Center of mass|centre]] for these planets remained the most accurate until the time of [[Johannes Kepler]] in the 17th century.<ref name=Joseph>George G. Joseph (2000). ''The Crest of the Peacock: Non-European Roots of Mathematics'', p. 408. [[Princeton University Press]].</ref>

In his ''Aryabhatiyabhasya'', a commentary on Aryabhata's ''[[Aryabhatiya]]'', Nilakantha developed a computational system for a partially [[heliocentrism|heliocentric]] planetary model in which Mercury, Venus, [[Mars]], [[Jupiter]] and [[Saturn]] orbit the [[Sun]], which in turn orbits the [[Earth]], similar to the [[Tychonic system]] later proposed by [[Tycho Brahe]] in the late 16th century. Most astronomers of the Kerala school who followed him accepted this planetary model.<ref name=Joseph/><ref>K. Ramasubramanian, M. D. Srinivas, M. S. Sriram (1994). "[https://physics.iitm.ac.in/~labs/amp/kerala-astronomy.pdf Modification of the earlier Indian planetary theory by the Kerala astronomers (c. 1500 AD) and the implied heliocentric picture of planetary motion]", ''[[Current Science]]'' '''66''', p. 784-790.</ref>

==Works of Nilakantha Somayaji==
{{further|Tantrasamgraha|Jyotirmimamsa}}

The following is a brief description of the works by Nilakantha Somayaji dealing with astronomy and mathematics.<ref name="text"/><ref>{{cite journal|last=A.K. Bag|date=1980|title=Indian literature on mathematics during 1400 - 1800 AD|journal=Indian Journal of History of Science|volume=15|issue=1|pages=79–93|url=http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005af2_79.pdf|access-date=30 January 2010|url-status=dead|archive-url=https://web.archive.org/web/20120309124530/http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005af2_79.pdf|archive-date=9 March 2012}}</ref>

#''[[Tantrasamgraha]]''
#''Golasara'' : Description of basic astronomical elements and procedures
#''Sidhhantadarpana'' : A short work in 32 slokas enunciating the astronomical constants with reference to the Kalpa and specifying his views on astronomical concepts and topics.
#''Candrachayaganita'' : A work in 32 verses on the methods for the calculation of time from the measurement of the shadow of the gnomon cast by the moon and vice versa.
#''Aryabhatiya-bhashya'' : Elaborate commentary on Aryabhatiya.
#''Sidhhantadarpana-vyakhya'' : Commentary on his own Siddhantadarapana.
#''Chandrachhayaganita-vyakhya'' : Commentary on his own Chandrachhayaganita.
#''Sundaraja-prasnottara'' : Nilakantha's answers to questions posed by Sundaraja, a Tamil Nadu-based astronomer.
#''Grahanadi-grantha'' : Rationale of the necessity of correcting old astronomical constants by observations.
#''Grahapariksakrama'' : Description of the principles and methods for verifying astronomical computations by regular observations.
#''[[Jyotirmimamsa]]'' : Analysis of astronomy

==See also==
*[[Indian mathematicians]]
*[[Indian astronomy]]

==References==
{{reflist}}

==Further reading==

*{{cite journal|last=R.C. Gupta|title=Second order interpolation in Indian mathematics up to the fifteenth century|journal=Indian Journal of History of Science|volume=4|issue=1 & 2|pages=87–98|url=http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005b65_86.pdf|url-status=dead|archive-url=https://web.archive.org/web/20120309121926/http://www.new.dli.ernet.in/rawdataupload/upload/insa/INSA_1/20005b65_86.pdf|archive-date=2012-03-09}}
* [[K. V. Sarma]] (2008) "Nilakantha Somayaji", [[Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures]] (2nd edition) edited by [[Helaine Selin]], Springer, {{ISBN|978-1-4020-4559-2}}.
*{{cite journal|last=Shailesh A Shirali|date=May 1997|title=Nilakantha, Euler and pi|journal=Resonance|pages=28–43|url=http://www.ias.ac.in/article/fulltext/reso/002/05/0029-0043|access-date=6 September 2016}}
*{{cite journal|last=Ranjan Roy|date=Dec 1990|title=The discovery of the series formula for π by Leibnitz, Gregory and Nilakantha|journal=Mathematics Magazine|publisher=[[Mathematical Association of America]]|volume=63|issue=5|pages=291–306|url=http://www.maa.org/programs/maa-awards/writing-awards/carl-b-allendoerfer-awards/the-discovery-of-the-series-formula-for-pi|access-date=6 September 2016|doi=10.2307/2690896|jstor=2690896}}

==External links==
{{commons category|Nilakantha Somayaji}}
* [https://chenthala.in/ Official Website of Chenthala Vishnu Temple]
* [https://chenthala.in/tantrasamgraham-tantra-sangraha-of-somayaji/ Tantrasamgraha Official Website]
* [https://chenthala.in/kelallur-nilakantha-somayajipadu/ Official Website of Kelallur Nilakantha Somayaji]

{{Indian mathematics}}

{{Authority control}}

{{DEFAULTSORT:Somayaji, Nilakantha}}
[[Category:1444 births]]
[[Category:1544 deaths]]
[[Category:Indian Hindus]]
[[Category:16th-century Indian astronomers]]
[[Category:Kerala school of astronomy and mathematics]]
[[Category:15th-century Indian mathematicians]]
[[Category:16th-century Indian mathematicians]]
[[Category:People from Malappuram district]]
[[Category:Scientists from Kerala]]
[[Category:15th-century Indian astronomers]]
[[Category:Scholars from Kerala]]

Nilakantha Somayaji - Revision history

imported>Florian Blaschke: sp