Indian astronomy

Indian astronomy—the earliest textual mention of which is given in the religious literature of India (2nd millennium BCE)—became an established tradition by the 1st millennium BCE, when "IAST|Jyotiṣa Vedānga" and other ancillary branches of learning called "Vedangas" began to take shape. During the following centuries a number of studied various aspects of astronomical sciences and global discourse with other cultures followed. A number of instruments were used in Indian astronomy, which was also applied for calendrical studies.

Early History

Early astronomy in India—like in other cultures— was intertwined with religion.Sarma 2008 in "Astronomy in India"] The first textual mention of astronomical concepts comes from the Vedas—religious literature of India. According to Sarma (2008): "One finds in the R.gveda intelligent speculations about the genesis of the universe from nonexistence, the configuration of the universe, the spherical self-supporting earth, and the year of 360 days divided into 12 equal parts of 30 days each with a periodical intercalary month." More on Indian astronomy with relation to religion is given in the section below.

The cardinal directions are found in the "Śulbasūtra" (1st millennium BCE), a treatise containing mathematical applications used for altar construction. Mathematics and astronomical instruments were employed to calculate time after sunlight, daylight periods, computation of sunrise, computation of sunset, and general measurement of time. Ōhashi (1993) states that "IAST|Jyotiṣa Vedānga" astronomy gained a foothold between the 6th and the 4th centuries BCE.Ōhashi 1993] The common era saw the presence of numerous "Siddhāntas", out of which the "Surya-siddhānta" was particularly notable. Both the "Yavanajataka" and "Romaka Siddhānta" confirm that Indian and western astronomical sciences had been a part of a global scientific discourse (given in the section below).

The "Pañcasiddhāntikā" (Varahimira, 505 CE) approximates the method for determination of the meridian direction from any three positions of the shadow using Gnomon. By the time of Aryabhata I the motion of planets was treated be be elliptical rather than circular. Other topics included definitions of different units of time, eccentric models of planetary motion, epicyclic models of planetary motion, and planetary longitude corrections for various terrestrial locations.

Relation with religion

In India astronomy and religion were interwoven during early times, begining from the Vedic Period (2nd millennium BCE-1st millennium BCE) when the Vedas were composed. Sarma (2008) notes that the Vedas are compositions of religion, and not science. However, they do hold a certain amount of astronomical information. The religious texts of India often contained astronomical observation for carrying out ritual associated with religion at a certain time. Sarma (2008) comments on one such text:

Hindus kept a pañcānga for calculations of "tithi" (lunar day), vāra (weekday), naksatra (asterism), and "karan" (half lunar day) for social and religious events. Klostermaier (2003) states that: "Indian astronomers calculated the duration of one "kalpa" (a cycle of the universe during which all the heavenly bodies return to their original positions) to be 4,320,000,000 years."Klostermaier 2003]

Calenders

The divisions of the year were on the basis of religious rites and seasons ("Rtu"). The duration from mid March—Mid May was taken to be spring ("vastanta"), mid May—mid July: summer, mid July—mid September: rains ("varsha"), mid September—mid November: autumn, mid November—mid January: winter, mid January—mid March: "dew" ("śiśira").

In the "IAST|Vedānga Jyotiṣa", the year begins with the winter solstice. [Bryant 2001:253] Hindu calendars have several eras:

* The Hindu calendar, counting from the start of the Kali Yuga, has its epoch on 18 February 3102 BC Julian (23 January 3102 BCE Gregorian).
* The Vikrama Samvat calendar, introduced about the 12th century, counts from 56-57 BCE.
* The "Saka Era", used in some Hindu calendars and in the Indian national calendar, has its epoch near the vernal equinox of year 78.
* The Saptarshi calendar traditionally has its epoch at 3076 BCE. [Cunningham, A. 1883. A Book of Indian Eras.]

J.A.B. van Buitenen (2008) reports on the calendars in India:

Astronomers

Instruments used

Among the devices used for astronomy was Gnomon, known as "Sanku", in which the shadow of a vertical rod is applied on a horizontal plane in order to ascertain the cardinal directions, the latitude of the point of observation, and the time of observation. This device finds mention in the works of Varāhamihira, Āryabhata, Bhāskara, Brahmagupta, among others.Abraham 2008] The Cross-staff, known as "Yasti-yantra", was used by the time of Bhaskara II (1114 – 1185 CE). This device could vary from a simple stick to V-shaped staffs designed specifically for determining angles with the help of a calibrated scale. The clepsydra ("Ghatī -yantra") was used in India for astronomical purposes until recent times. Ōhashi (2008) notes that: "Several astronomers also described water-driven instruments such as the model of fighting sheep."

The armillary sphere was used for observation in India since early times, and finds mention in the works of Āryabhata (476 CE).Sarma 2008 in "Armillary Spheres in India"] The "Goladīpikā"—a detailed treatise dealing with globes and the armillary sphere was composed between 1380–1460 CE by Parameśvara. On the subject of the usage of the armillary sphere in India, Ōhashi (2008) writes: "The Indian armillary sphere ("gola-yantra") was based on equatorial coordinates, unlike the Greek armillary sphere, which was based on ecliptical coordinates, although the Indian armillary sphere also had an ecliptical hoop. Probably, the celestial coordinates of the junction stars of the lunar mansions were determined by the armillary sphere since the seventh century or so. There was also a celestial globe rotated by flowing water."

An instrument invented by the mathematician and astronomer Bhaskara II (1114 – 1185 CE) consisted of a rectangular board with a pin and an index arm. This device—called the "Phalaka-yantra"—was used to determine time from the sun's altitude. The "Kapālayantra" was a equatorial sundial instrument used to determine the sun’s azimuth. "Kartarī-yantra" combined two semicircular board instruments to give rise to a 'scissors instrument'. Introduced from the Islamic world and first finding mention in the works of Mahendra Sūri—the court astronomer of Firuz Shah Tughluq (1309 - 1388 CE)—the astrolabe was further mentioned by Padmanābha (1423 CE) and Rāmacandra (1428 CE) as its use grew in India.

Invented by "Padmanābha", a nocturnal polar rotation instrument consisted of a rectangular board with a slit and a set of pointers with concentric graduated circles. Time and other astronomical quantities could be calculated by adjusting the slit to the directions of α and β Ursa Minor. Ōhashi (2008) further explains that: "Its backside was made as a quadrant with a plumb and an index arm. Thirty parallel lines were drawn inside the quadrant, and trigonometrical calculations were done graphically. After determining the sun’s altitude with the help of the plumb, time was calculated graphically with the help of the index arm."

Ōhashi 2008 reports on the observatories constructed by Jai Singh II of Amber:

The seamless celestial globe invented in Mughal India, specifically Lahore and Kashmir, is considered to be one of the most impressive astronomical instruments and remarkable feats in metallurgy and engineering. All globes before and after this were seamed, and in the 20th century, it was believed by metallurgists to be technically impossible to create a metal globe without any , even with modern technology. It was in the 1980s, however, that Emilie Savage-Smith discovered several celestial globes without any seams in Lahore and Kashmir. The earliest was invented in Kashmir by Ali Kashmiri ibn Luqman in 998 AH (1589-90 CE) during Akbar the Great's reign; another was produced in 1070 AH (1659-60 CE) by Muhammad Salih Tahtawi with Arabic and Sanskrit inscriptions; and the last was produced in Lahore by a Hindu metallurgist Lala Balhumal Lahuri in 1842 during Jagatjit Singh Bahadur's reign. 21 such globes were produced, and these remain the only examples of seamless metal globes. These Mughal metallurgists developed the method of lost-wax casting in order to produce these globes. [citation|first=Emilie|last=Savage-Smith|title=Islamicate Celestial Globes: Their history, Construction, and Use|publisher=Smithsonian Institution Press, Washington, D.C.|year=1985]

Global discourse

Ōhashi 2008 notes the foreign Greek influence and writes: 'Greek ideas of astronomy and astrology had some influence in India from the second to the fourth century AD. After that, Hindu astronomy ("Jyotisa") established itself as an independent discipline, and several fundamental texts called "Siddhāntas" were composed.'Ōhashi 2008 in "Astronomical Instruments in India"]

Indian astronomy reached China with the expansion of Buddhism during the Later Han dynasty (25–220 CE). Further translation of Indian works on astronomy was completed in China by the Three Kingdoms era (220–265 CE).Ōhashi 2008 in "Astronomy: Indian Astronomy in China"] However, the most detailed incorporation of Indian astronomy occurred only during the Tang Dynasty (618-907) when a number of Chinese scholars—such as Yi Xing— were versed both in Indian and Chinese astronomy. A system of Indian astronomy was recorded in China as "Jiuzhi-li" (718 CE), the author of which was an Indian by the name of Qutan Xida—a translation of Devanagari Gotama Siddha—the director of the Tang dynasty's national astronomical observatory.

Fragments of texts during this period indicate that Arabs adopted the sine function (inherited from Indian mathematics) instead of the chords of arc used in Hellenistic mathematics.Dallal, page 162] Another Indian influence was an approximate formula used for timekeeping by Muslim astronomers. [King, page 240]

Nearly a thousand years later in the 17th century, the Mughal Empire saw a synthesis between Islamic and Indian astronomy, where Islamic observational instruments were combined with Hindu computational techniques. While there appears to have been little concern for planetary theory, Muslim and Hindu astronomers in India continued to make advances in observational astronomy and produced nearly a hundred Zij treatises. Humayun built a personal observatory near Delhi, while Jahangir and Shah Jahan were also intending to build observatories but were unable to do so. After the decline of the Mughal Empire, it was a Hindu king, Jai Singh II of Amber, who attempted to revive both the Islamic and Hindu traditions of astronomy which were stagnating in his time. In the early 18th century, he built several large observatories called Yantra Mandirs in order to rival Ulugh Beg's Samarkand observatory and in order to improve on the earlier Hindu computations in the "Siddhantas" and Islamic observations in "Zij-i-Sultani". The instruments he used were influenced by Islamic astronomy, while the computational techniques were derived from Hindu astronomy. [citation|title=Sawai Jai Singh and His Astronomy|first=Virendra Nath|last=Sharma|year=1995|publisher=Motilal Banarsidass Publ.|isbn=8120812565|pages=8-9] [Baber, pages 82-89]

Through Islamic astronomy, Indian astronomy had an influence on European astronomy via Arabic translations. During the Latin translations of the 12th century, Muhammad al-Fazari's "Great Sindhind", which was based on the "Surya Siddhanta" and the works of Brahmagupta, was translated into Latin in 1126 and was influential at the time. [Joseph, page 306]

Some scholars have suggested that knowledge of the results of the Kerala school of astronomy and mathematics may have been transmitted to Europe through the trade route from Kerala by traders and Jesuit missionaries. Kerala was in continuous contact with China and Arabia, and Europe. The existence of circumstantial evidence [Raju, C. K. (2001). "Computers, Mathematics Education, and the Alternative Epistemology of the Calculus in the Yuktibhasa", "Philosophy East and West" 51 (3), p. 325-362] such as communication routes and a suitable chronology certainly make such a transmission a possibility. However, there is no direct evidence by way of relevant manuscripts that such a transmission took place.Almeida, D. F., J. K. John, and A. Zadorozhnyy. 2001. "Keralese Mathematics: Its Possible Transmission to Europe and the Consequential Educational Implications." "Journal of Natural Geometry", 20:77-104]

Later in the early 18th century, Jai Singh II of Amber invited European Jesuit astronomers to one of his Yantra Mandir observatories, who had bought back the astronomical tables compiled by Philippe de La Hire in 1702. After examining La Hire's work, Jai Singh concluded that the observational techniques and instruments used in European astronomy were inferior to those used in India at the time. It is uncertain whether he was aware of the Copernican Revolution via the Jesuits, but it appears Indian astronomers were not concerned with planetary theory, hence the theoretical advances in Europe did not interest them at the time. [Baber, pages 89-90]

See also

*History of astronomy
*Chinese astronomy
*Islamic astronomy
*Hindu calendar
*Hindu cosmology

Notes

References

* Abraham, G. (2008) in "Gnomon in India", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 1035-1037. ISBN 978-1-4020-4559-2.
*
*Harvard reference|last=Dallal|first=Ahmad |contribution=Science, Medicine and Technology|editor-last=Esposito|editor-first=John|title=The Oxford History of Islam|year=1999|publisher=Oxford University Press, New York.
* Hayashi, Takao (2008). "Aryabhata I". Encyclopedia Britannica.
* Hayashi, Takao (2008). "Bhaskara I". Encyclopedia Britannica.
* Hayashi, Takao (2008). "Brahmagupta". Encyclopedia Britannica.
* Hayashi, Takao (2008). "Shripati". Encyclopedia Britannica.
* J.A.B. van Buitenen (2008). "calendar". Encyclopedia Britannica.
* Joseph, George G. (2000). "The Crest of the Peacock: Non-European Roots of Mathematics", 2nd edition. Penguin Books, London. ISBN 0691006598.
*Harvard reference|last=King|first=David A.|year=2002|title=A Vetustissimus Arabic Text on the Quadrans Vetus|journal=Journal for the History of Astronomy|volume=33|pages=237-255.
* Klostermaier, Klaus K. (2003) in "Hinduism, History of Science and Religion", "Encyclopedia of Science and Religion" edited by J. Wentzel Vrede van Huyssteen. Macmillan Reference USA. 405-410. ISBN 0-02-865704-7.
* Ōhashi, Yukio (2008) in "Astronomy: Indian Astronomy in China", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 321-324. ISBN 978-1-4020-4559-2.
* Ōhashi, Yukio (2008) in "Astronomical Instruments in India", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 269-273. ISBN 978-1-4020-4559-2.
* Ōhashi, Yukio (1993). "Development of Astronomical Observation in Vedic and Post-Vedic India". Indian Journal of History of Science 28.3 (1993): 185–251.
* Ōhashi, Yukio (1997). "Early History of the Astrolabe in India". Indian Journal of History of Science 32.3 (1997): 199-295.
* Sarma, K.V. (2008) in "Acyuta Pisarati", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 19. ISBN 978-1-4020-4559-2.
* Sarma, K.V. (2008) in "Armillary Spheres in India", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 243. ISBN 978-1-4020-4559-2.
* Sarma, K.V. (2008) in "Astronomy in India", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 317-321. ISBN 978-1-4020-4559-2.
* Sarma, K.V. (2008) in "Lalla", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 1215. ISBN 978-1-4020-4559-2.
* Sharma, V.N. (2008) in "Observatories in India", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 1785-1788. ISBN 978-1-4020-4559-2.
* Subbaarayappa, B.V. (1989) in "Indian astronomy: an historical perspective", "Cosmic Perspectives" edited by Biswas etc. Cambridge University Press. 25-41. ISBN 0521343542.
* Tripathi, V.N. (2008) in "Astrology in India", "Encyclopaedia of the History of Science, Technology, and Medicine in Non-Western Cultures (2nd edition)" edited by Helaine Selin. Springer. 264-267. ISBN 978-1-4020-4559-2.