Vatasseri Parameshvara Nambudiri ( 1380–1460) was a major

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

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 ...

and

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

of the

Kerala school of astronomy and mathematics The Kerala school of astronomy and mathematics or the Kerala school was a school of Indian mathematics, mathematics and Indian astronomy, astronomy founded by Madhava of Sangamagrama in Kingdom of Tanur, Tirur, Malappuram district, Malappuram, K ...

founded by Madhava of Sangamagrama. He was also an

astrologer Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions ...

. Parameshvara was a proponent of observational astronomy in

medieval India Medieval India was a long period of post-classical history in the Indian subcontinent between the ancient and modern periods. It is usually regarded as running approximately from the break-up of the Gupta Empire in the 6th century to the star ...

and he himself had made a series of eclipse observations to verify the accuracy of the computational methods then in use. Based on his eclipse observations, Parameshvara proposed several corrections to the astronomical parameters which had been in use since the times of

Aryabhata Aryabhata ( ISO: ) or Aryabhata I (476–550 CE) was the first of the major mathematician-astronomers from the classical age of Indian mathematics and Indian astronomy. His works include the '' Āryabhaṭīya'' (which mentions that in 3600 ' ...

. The computational scheme based on the revised set of parameters has come to be known as the ''Drgganita'' or Drig system. Parameshvara was also a prolific writer on matters relating to astronomy. At least 25 manuscripts have been identified as being authored by Parameshvara.

Biographical details

Parameshvara was a

Hindu Hindus (; ; also known as Sanātanīs) are people who religiously adhere to Hinduism, also known by its endonym Sanātana Dharma. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pp. 35–37 Historically, the term has also be ...

of Bhrgu gotra following the Ashvalayanasutra of the

Rigveda The ''Rigveda'' or ''Rig Veda'' (, , from wikt:ऋच्, ऋच्, "praise" and wikt:वेद, वेद, "knowledge") is an ancient Indian Miscellany, collection of Vedic Sanskrit hymns (''sūktas''). It is one of the four sacred canoni ...

. Parameshvara's family name (''Illam'') was Vatasseri and his family resided in the village of Alathiyur (Sanskritised as ''Asvatthagrama'') in Tirur,

Kerala Kerala ( , ) is a States and union territories of India, state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile ...

. Alathiyur is situated on the northern bank of the river Nila (river Bharathappuzha) at its mouth in Kerala. He was a grandson of a disciple of Govinda Bhattathiri (1237–1295 CE), a legendary figure in the astrological traditions of

. Parameshvara studied under teachers Rudra and Narayana, and also under Madhava of Sangamagrama (c. 1350 – c. 1425) the founder of the

. Damodara, another prominent member of the Kerala school, was his son and also his pupil. Parameshvara was also a teacher of Nilakantha Somayaji (1444–1544) the author of the celebrated Tantrasamgraha.

Work

Parameshvara wrote commentaries on many mathematical and astronomical works such as those by Bhāskara I and

. He made a series of eclipse observations over a 55-year period. Constantly attempted to compare these with the theoretically computed positions of the planets. He revised planetary parameters based on his observations. One of Parameshvara's more significant contributions was his mean value type formula for the inverse interpolation of the sine. He was the first mathematician to give a formula for the

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

of the

circle A circle is a shape consisting of all point (geometry), points in a plane (mathematics), plane that are at a given distance from a given point, the Centre (geometry), centre. The distance between any point of the circle and the centre is cal ...

circumscribing a cyclic quadrilateral. The expression is sometimes attributed to Lhuilier 782 350 years later. With the sides of the cyclic quadrilateral being ''a, b, c,'' and ''d'', the radius ''R'' of the circumscribed circle is: :

R = \sqrt .

Works by Parameshvara

The following works of Parameshvara are well-known. A complete list of all manuscripts attributed to Parameshvara is available in Pingree. *''Bhatadipika'' – Commentary on

Āryabhaṭīya ''Aryabhatiya'' (IAST: ') or ''Aryabhatiyam'' ('), a Indian astronomy, Sanskrit astronomical treatise, is the ''Masterpiece, magnum opus'' and only known surviving work of the 5th century Indian mathematics, Indian mathematician Aryabhata. Philos ...

of Āryabhaṭa I *''Karmadipika'' – Commentary on ''Mahabhaskariya'' of Bhaskara I *''Paramesvari'' – Commentary on ''Laghubhaskariya'' of Bhaskara I *''Sidhantadipika'' – Commentary on ''Mahabhaskariyabhashya'' of Govindasvāmi *''Vivarana'' – Commentary on Surya Siddhanta and Lilāvati *''Drgganita'' – Description of the Drig system (composed in 1431 CE) *''Goladipika'' – Spherical geometry and astronomy (composed in 1443 CE) *''Grahanamandana'' – Computation of eclipses (Its epoch is 15 July 1411 CE.) *''Grahanavyakhyadipika'' – On the rationale of the theory of eclipses *''Vakyakarana'' – Methods for the derivation of several astronomical tables

References

External links

*
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* {{Authority control 1380s births 1425 deaths Indian Hindus 14th-century Indian mathematicians 15th-century Indian astronomers Medieval Indian astrologers Kerala school of astronomy and mathematics 15th-century Indian mathematicians 14th-century astrologers 15th-century astrologers Scientists from Kerala People from Malappuram district Scholars from Kerala

Biographical details

Work

Works by Parameshvara

See also

References

Further reading

External links