Surya Siddhanta

Verse 1.1 (prayer to Brahman)

The Surya Siddhanta (IAST: Sūrya Siddhānta; lit. 'Sun Treatise') is a Sanskrit treatise in Indian astronomy dated to 4th to 5th century,[1][2] in fourteen chapters.[3][4][5] The Surya Siddhanta describes rules to calculate the motions of various planets and the moon relative to various constellations, diameters of various planets, and calculates the orbits of various astronomical bodies.[6][7] The text is known from a 15th-century CE palm-leaf manuscript, and several newer manuscripts.[8] It was composed or revised probably c. 800 CE from an earlier text also called the Surya Siddhanta.[5] The Surya Siddhanta text is composed of verses made up of two lines, each broken into two halves, or pãds, of eight syllables each.[3]

As per al-Biruni, the 11th-century Persian scholar and polymath, a text named the Surya Siddhanta was written by Lāṭadeva, a student of Aryabhatta I.[8][9] The second verse of the first chapter of the Surya Siddhanta attributes the words to an emissary of the solar deity of Hindu mythology, Surya, as recounted to an asura called Maya at the end of Satya Yuga, the first golden age from Hindu texts, around two million years ago.[8][10]

The text asserts, according to Markanday and Srivatsava, that the Earth is of a spherical shape.[4] It treats Earth as stationary globe around which Sun orbits, and makes no mention of Uranus, Neptune and Pluto.[11] It calculates the Earth's diameter to be 8,000 miles (modern: 7,928 miles),[6] the diameter of the Moon as 2,400 miles (actual ~2,160)[6] and the distance between the Moon and the Earth to be 258,000 miles[6] (now known to vary: 221,500–252,700 miles (356,500–406,700 kilometres).[12] The text is known for some of the earliest known discussions of fractions and trigonometric functions.[1][2][13]

The Surya Siddhanta is one of several astronomy-related Hindu texts. It represents a functional system that made reasonably accurate predictions.[14][15][16] The text was influential on the solar year computations of the luni-solar Hindu calendar.[17] The text was translated into Arabic and was influential in medieval Islamic geography.[18] The Surya Siddhanta has the largest number of commentators among all the astronomical texts written in India. It includes information about the mean orbital parameters of the planets, such as the number of mean revolutions per Mahayuga, the longitudinal changes of the orbits, and also includes supporting evidence and calculation methods.[3]

  1. ^ a b Menso Folkerts, Craig G. Fraser, Jeremy John Gray, John L. Berggren, Wilbur R. Knorr (2017), Mathematics, Encyclopaedia Britannica, Quote: "(...) its Hindu inventors as discoverers of things more ingenious than those of the Greeks. Earlier, in the late 4th or early 5th century, the anonymous Hindu author of an astronomical handbook, the Surya Siddhanta, had tabulated the sine function (...)"
  2. ^ a b John Bowman (2000). Columbia Chronologies of Asian History and Culture. Columbia University Press. p. 596. ISBN 978-0-231-50004-3., Quote: "c. 350-400: The Surya Siddhanta, an Indian work on astronomy, now uses sexagesimal fractions. It includes references to trigonometric functions. The work is revised during succeeding centuries, taking its final form in the tenth century."
  3. ^ a b c Cite error: The named reference burgess was invoked but never defined (see the help page).
  4. ^ a b Markanday, Sucharit; Srivastava, P. S. (1980). "Physical Oceanography in India: An Historical Sketch". Oceanography: The Past. Springer New York. pp. 551–561. doi:10.1007/978-1-4613-8090-0_50. ISBN 978-1-4613-8092-4., Quote: "According to Surya Siddhanta the earth is a sphere."
  5. ^ a b Plofker, pp. 71–72.
  6. ^ a b c d Richard L. Thompson (2007). The Cosmology of the Bhagavata Purana. Motilal Banarsidass. pp. 16, 76–77, 285–294. ISBN 978-81-208-1919-1.
  7. ^ Cite error: The named reference montgomery104 was invoked but never defined (see the help page).
  8. ^ a b c Thompson, Richard L. (2007). The Cosmology of the Bhāgavata Purāṇa: Mysteries of the Sacred Universe. Motilal Banarsidass. pp. 15–18. ISBN 978-81-208-1919-1.
  9. ^ Hockey, Thomas (2014). "Latadeva". In Hockey, Thomas; Trimble, Virginia; Williams, Thomas R.; Bracher, Katherine; Jarrell, Richard A.; Marché, Jordan D.; Palmeri, JoAnn; Green, Daniel W. E. (eds.). Biographical Encyclopedia of Astronomers. New York, NY: Springer New York. p. 1283. Bibcode:2014bea..book.....H. doi:10.1007/978-1-4419-9917-7. ISBN 978-1-4419-9916-0. S2CID 242158697.
  10. ^ Gangooly 1935, p. ix (Introduction): Calculated date of 2163102 B.C. for "the end of the Golden Age (Krta yuga)" mentioned in Surya Siddhanta 1.57.
  11. ^ Richard L. Thompson (2004). Vedic Cosmography and Astronomy. Motilal Banarsidass. p. 10. ISBN 978-81-208-1954-2.
  12. ^ Murphy, T W (1 July 2013). "Lunar laser ranging: the millimeter challenge" (PDF). Reports on Progress in Physics. 76 (7): 2. arXiv:1309.6294. Bibcode:2013RPPh...76g6901M. doi:10.1088/0034-4885/76/7/076901. PMID 23764926. S2CID 15744316.
  13. ^ Brian Evans (2014). The Development of Mathematics Throughout the Centuries: A Brief History in a Cultural Context. Wiley. p. 60. ISBN 978-1-118-85397-9.
  14. ^ David Pingree (1963), Astronomy and Astrology in India and Iran, Isis, Volume 54, Part 2, No. 176, pages 229-235 with footnotes
  15. ^ Duke, Dennis (2005). "The Equant in India: The Mathematical Basis of Ancient Indian Planetary Models". Archive for History of Exact Sciences. 59 (6). Springer Nature: 563–576. Bibcode:2005AHES...59..563D. doi:10.1007/s00407-005-0096-y. S2CID 120416134.
  16. ^ Pingree, David (1971). "On the Greek Origin of the Indian Planetary Model Employing a Double Epicycle". Journal for the History of Astronomy. 2 (2). SAGE Publications: 80–85. Bibcode:1971JHA.....2...80P. doi:10.1177/002182867100200202. S2CID 118053453.
  17. ^ Roshen Dalal (2010). Hinduism: An Alphabetical Guide. Penguin Books. p. 89. ISBN 978-0-14-341421-6., Quote: "The solar calendar is based on the Surya Siddhanta, a text of around 400 CE."
  18. ^ Canavas, Constantin (2014), "Geography and Cartography" (PDF), The Oxford Encyclopedia of Philosophy, Science, and Technology in Islam, Oxford University Press, doi:10.1093/acref:oiso/9780199812578.001.0001, ISBN 978-0-19-981257-8, retrieved 2020-07-19