Indian astronomy
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'''Indian astronomy''' refers to the study of [[astronomy]] in the [[Indian subcontinent]], as documented in literature spanning the [[Maurya period|Maurya]] ([[Vedanga Jyotisha]], ca. 3rd century BCE) to the [[Mughal Empire|Mughal]] (such as the 16th century [[Kerala school of astronomy and mathematics|Kerala school]]) periods.
The astronomy and the [[astrology]] of [[ancient India]] ([[Jyotisha]]) is mainly based on a [[sidereal]] system of calculations. A [[Tropics|tropical]] system has also been used in a few cases. For example, a tropical determination of the [[Uttarayana]] (Uttarāyana उत्तरायन) is found in the ''[[Mahabharata]]''{{Fact|date=September 2007}}, and also in the ''[[Vedanga Jyotisha]]'' of [[Lagadha]],<ref>Pingree(1978)</ref> but not in subsequent systems, which have been sidereal.
The first named authors writing treatises on astronomy emerge from the 5th century CE, the date when the classical period of Indian astronomy can be said to begin. Besides the theories of [[Aryabhata]] in the ''[[Aryabhatiya]]'' and the lost ''Arya-siddhānta'', we find the ''[[Pancha-Siddhāntika]]'' of [[Varahamihira]]. From this time on, we find a predominance of [[geocentric model]]s, and possibly [[Heliocentrism|heliocentric]] models, in Indian astronomy, in contrast to the "[[Mount Meru (mythology)|Merucentric]]" astronomy of [[Puranas|Puranic]], [[Jainism|Jaina]] and [[Buddhism|Buddhist]] traditions whose actual [[Indian mathematics|mathematics]] has been largely lost and only fabulous accounts remain.{{Fact|date=August 2007}}
==Literature==
While the [[Vedanga Jyotisha]] of Ladaga documents the state of Indian astronomy in the [[Maurya period]], astronomy of the classical [[Gupta period]], the centuries following [[Indo-Greek]] contact, is documented in treatises known as [[Siddhanta]]s (which means "established conclusions" <ref>Cf. Burgess, Appendix by Whitney p. 439.</ref> ).
[[Varahamihira]] in his ''[[Pancha-Siddhantika]]'' contrasts five fo these: The [[Surya Siddhanta]] besides the [[Paitamaha Siddhanta]]s (which is more similar to the "classical" [[Vedanga Jyotisha]]), the [[Paulisha Siddhanta|Paulisha]] and [[Roma ka Siddhanta|Romaka]] Siddhantas (directly based on Hellenistic astronomy) and the [[Vasishta Siddhanta]].
The work referred to by the title ''Surya Siddhanta'' has been repeatedly recast. There may have been an early work under that title dating back to the Buddhist Age of India (3rd century BC). The work as preserved and edited by Burgess (1858) dates to the Middle Ages.
Whitney classifies these ancient siddhāntas into four categories : "a revelation", "attributed to ancient and renowned sage", "works of actual authors", and "later texts of known date and authorship" . Only a few of these ancient siddhāntas can be adequately reconstructed and some of them might have been vitiated by later interpolators <ref>Cf. Burgess, Appendix by Whitney p. 441-444.</ref> .
Whitney's list of these siddhāntas are as follows according to four categories of Whitney <ref>Cf. Burgess, Appendix by Whitney p. 439-444.</ref>:
#''Revelations :'' (1)Brahma-siddhānta (a part of {{IAST|Viṣṇu-dharmottara-Purāṇa}}; now lost), (2)Surya-siddhānta, (3)Soma-siddhānta(Bentley said it followed the system of Surya Siddhānta), (4){{IAST|Bṛhaspati}}-siddhānta (Whitney could not locate any extant version), (5)Nārada-siddhānta.
#''By ancient sages :'' (6)Garga-siddhānta, (7)Vyāsa-siddhānta, (8)Parāśara-siddhānta, (9)Pauliśa-siddhānta, (10)Pulastya-siddhānta, (11){{IAST|Vasiṣṭha}}-siddhānta.
#''Ancient authors :'' (12)Laghu Arya-siddhānta, (13){{IAST|Bṛihad}}-Arya-siddhānta, (14)Varāha-siddhānta, (15)Brahma-siddhānta (of Brahmagupta), (16)Romaka-siddhānta.
#''Dated authors :'' (17)Bhoja-siddhānta, (18)Siddhānta-śiromani, (19)Siddhānta-sundara, (20)Graha-lāghava, (21)Siddhānta-tattva-viveka, (22)Siddhānta-sārvabhauma.
==Coordinate system==
In Hindu Astronomy, the [[vernal equinox]] (the [[First Point of Aries]]) is often calculated at 23°From 0° [[Aries (constellation)|Aries]] (1950 CE), i.e. about 7° [[Pisces (constellation)|Pisces]].<ref>(Frawley 1991:148){{Verify credibility|date=September 2007}}</ref> The constellation that marks this vernal [[equinox]] is the Uttarabhadra. {{Fact|date=August 2007}}
In the time of the Puranas, the vernal equinox was marked by the Ashwini [[constellation]] (beginning of Aries), which gives a date of about 300-500 CE. The [[Vishnu Purana]] (2.8.63) states that the equinoxes occur when the Sun enters Aries] and [[Libra (constellation)|Libra]], and that when the sun enters [[Capricorn]], his northern course (from winter to summer [[solstice]]) commences, and the southern course when he enters [[Cancer]].The Brahmanas place the Equinox in Krittika (Pleidas) and the Rig Veda in Mrigasira (Orion). These would indicate a time of around 1900 BCE and 4000 BCE, respectively. {{Fact|date=August 2007}}
In the [[Surya Siddhanta]], the rate of [[precession]] is set at 54" (it actually is 50.3"), which is much more accurate than the number calculated by the [[Greek astronomy|Greeks]].<ref>(Frawley 1991:148){{Verify credibility|date=September 2007}}</ref>
The Hindus use a system of 27 or 28 [[Nakshatra]]s ([[Lunar mansion|lunar constellations]]) to calculate a [[month]]. Each month can be divided into 30 lunar [[tithi]]s (days). There are usually 360 or 366 days in a year. {{Fact|date=August 2007}}
It has been argued that Nilakantha Somayaji's (1444-1550) work shows a better equation of the center for Mercury and Venus "than was available either in the earlier Indian works or in the [[Islamic astronomy|Islamic]] or European traditions of astronomy till the work of [[Johannes Kepler|Kepler]], which was to come more than a hundred years later."<ref>Ramasubramanian et al. 1994, cited in Subhash Kak. Birth and Early Development of Indian Astronomy. In Astronomy across cultures: The History of Non-Western Astronomy, Helaine Selin (ed), Kluwer, [[2000]]</ref>
== Computational planetary models ==
There are a large number of computational planetary models presently employed by almanac makers in India. Many Indian almanacs are now prepared on the basis of modern astronomy, including the Rashtriya Panchanga published by government, which no pandit buys. Surya Siddhānta, two Ārya Siddhāntas of two Āryabhattas and Brahma Siddhānta are major ancient theoretical models which form the basis of most of traditional almanacs. Of these [[Surya Siddhanta]] ("Saura") is the most important, which Vārāha Mihira had declared in ca. 550 AD to be the "most accurate" <ref>cf. G. Thibaut, Pañcasiddhāntika, chapter 1, verse 4.</ref>. It is interesting to note that Vārāha Mihira did not include [[Aryabhatiya]] among the five major siddhantas dealt by him, although Āryabhatiya had been written just half a century before Pañcasiddhāntika.
===Āryabhatan model===
{{main|Aryabhatiya}}
[[Aryabhata]] ([[476]]–[[550]]), in his magnum opus ''[[Aryabhatiya]]'', propounded a computational system based on a planetary model in which the Earth was taken to be [[Earth's rotation|rotating on its axis]] and the periods of the planets were given with respect to the Sun. Some have interpreted this to be a [[heliocentrism|heliocentric]] model,<ref>[[Bartel Leendert van der Waerden|B. L. van der Waerden]] (1970), ''Das heliozentrische System in der griechischen,persischen und indischen Astronomie,'' Naturforschenden Gesellschaft in Zürich, Zürich: Kommissionsverlag Leeman AG. ([[cf.]] [[Noel Swerdlow]] (June 1973), "Review: A Lost Monument of Indian Astronomy", ''Isis'' '''64''' (2), p. 239-243.)
<br>[[Bartel Leendert van der Waerden|B. L. van der Waerden]] (1987), "The heliocentric system in Greek, Persian, and Indian astronomy", in "From deferent to equant: a volume of studies in the history of science in the ancient and medieval near east in honor of E. S. Kennedy", ''[[New York Academy of Sciences]]'' '''500''', p. 525-546. ([[cf.]] Dennis Duke (2005), "The Equant in India: The Mathematical Basis of Ancient Indian Planetary Models", ''Archive for History of Exact Sciences'' '''59''', p. 563–576.).</ref><ref>Thurston (1994), p. 188.
{{quote|"Not only did Aryabhata believe that the earth rotates, but there are glimmerings in his system (and other similar systems) of a possible underlying theory in which the earth (and the planets) orbits the sun, rather than the sun orbiting the earth. The evidence is that the basic planetary periods are relative to the sun."}}</ref><ref>[[Lucio Russo]] (2004), ''The Forgotten Revolution: How Science Was Born in 300 BC and Why It Had To Be Reborn'', [[Springer Science+Business Media|Springer]], Berlin, ISBN 978-3-540-20396-4. ([[cf.]] Dennis Duke (2005), "The Equant in India: The Mathematical Basis of Ancient Indian Planetary Models", ''Archive for History of Exact Sciences'' '''59''', p. 563–576.)</ref>
but this view has been disputed by others.<ref>[[Noel Swerdlow]] (June 1973), "Review: A Lost Monument of Indian Astronomy" [review of [[Bartel Leendert van der Waerden|B. L. van der Waerden]], ''Das heliozentrische System in der griechischen, persischen und indischen Astronomie''], ''Isis'' '''64''' (2), p. 239-243.
{{quote|"Such an interpretation, however, shows a complete misunderstanding of Indian planetary theory and is flatly contradicted by every word of Aryabhata's description."}}</ref><ref>David Pingree (1973), "The Greek Influence on Early Islamic Mathematical Astronomy", ''Journal of the American Oriental Society'' '''93''' (1), p. 32.
{{quote|"The reader should note that, in writing this survey, I have disregarded the rather divergent views of [[Bartel Leendert van der Waerden|B. L. van der Waerden]]; these have been most recently expounded in his ''Das heliozentrische System in der griechischen, persischen und indischen Astronomie'', Zürich 1970."}}</ref><ref>Dennis Duke (2005), "The Equant in India: The Mathematical Basis of Ancient Indian Planetary Models", ''Archive for History of Exact Sciences'' '''59''', p. 563–576 [http://people.scs.fsu.edu/~dduke/india8.pdf].
{{quote|"Thus for both outer and inner planets, the mean motion given is the heliocentric mean motion of the planet. There is no textual evidence that the Indians knew anything about this, and there is an overwhelming amount of textual evidence confirming their geocentric point of view. Some commentators, most notably van der Waerden, have however argued in favor of an underlying ancient Greek heliocentric basis, of which the Indians were unaware. See, e.g. B. L. van der Waerden, “The heliocentric system in greek, persian, and indian astronomy”, in ''From deferent to equant: a volume of studies in the history of science in the ancient and medieval near east in honor of E. S. Kennedy'', Annals of the new york academy of sciences, 500 (1987), 525-546. More recently this idea is developed in about as much detail as the scant evidence allows in L. Russo, ''The Forgotten Revolution'' (2004)."}}</ref>
He recognized that the light from the Moon and the planets was reflected from the Sun and accurately calculated many astronomical constants, such as the periods of the planets, times of the [[solar eclipse|solar]] and [[lunar eclipse|lunar]] [[eclipse]]s, and the instantaneous motion of the Moon (expressed as a [[differential equation]]).<ref>Joseph (2000) {{page number}}</ref><ref>Thurston (1994).</ref> The first major astronomer to attack the ''Aryabhatiya'' was [[Varahamihira]].<ref>[[Varahamihira]], ''Panchsiddhāntikā''-3.6-7, translation and commentary by G.Thibaut and Sudhakar Dwivedi.</ref> [[Brahmagupta]] was the greatest critic of Aryabhatiya; he devoted an entire chapter 'Tantra Parikshā' in his treatise ''[[Brahmasphutasiddhanta|Brāhm-Sphuta-Siddhānta]]'' to criticizng the ''Aryabhatiya'' in the harshest of terms.<ref>Gunākar Mule, Itihāsa, p.31.</ref>
[[Bhaskara II]] ([[1114]]–[[1185]]) expanded on early models in his astronomical treatise ''Siddhanta-Shiromani'', where he mentioned the law of [[gravity]], discovered that the planets don't orbit at a uniform [[velocity]], and calculated many astronomical constants based on this model, such as the solar and lunar eclipses, and the velocities and instantaneous motions of the planets.<ref>Joseph (2000) {{page number}}</ref><ref> Bhaskaracharya's Siddhantashiromani (Golādhyāya, Bhuvanakośa,6), p. 180-181.
::आकृष्टिशक्तिश्च मही तया यत् खस्थं गुरु स्वाभिमुखं स्वशक्त्या ।
::आकृष्यते तत्पततीव भाति समे समन्तात् क्व पतत्वियं खे ॥६॥
Jain (2000) p. 116 {{Verify credibility|date=September 2007}} interpreted Bhāskarāchārya to the effect that "Earth has a force of attraction, from this force Earth pulls nearby things towards herself; this force of attraction is greater in the vicinity of Earth and lesser as distance increases ... and heavier objects do not take longer time to fall" </ref>
[[Arabic]] translations of Aryabhata's ''Aryabhatiya'', known as ''Jije Al Arzbahar'' by [[al-Khwarizmi]], were available from the [[8th century]] but is not available now, while [[Latin]] translations were available from the [[13th century]],<ref>[http://www-history.mcs.st-andrews.ac.uk/HistTopics/Arabic_numerals.html The Arabic numeral system]</ref><ref>[http://www.infinityfoundation.com/mandala/t_es/t_es_shah_m_astronomy_frameset.htm Indian Astronomy Through Ages]</ref> before [[Copernicus]] had written ''De revolutionibus orbium coelestium''. In 1030, [[Abū Rayhān al-Bīrūnī|al-Biruni]] had also discussed the theories of [[Aryabhata]], [[Brahmagupta]] and [[Varahamihira]] in his ''Ta'rikh al-Hind'' (''Indica'' in Latin; ''Chronicles of India'' in English), often quoting Brahmagupta's ''Brahmasiddhānta'' for authoritative statements. Regarding whether the earth was at rest or revolving, the latter being the view of Aryabhata, he wrote:<ref>Edward Sachau (tr. and ed.), ''Alberuni's India'', Indialog Publications, New Delhi, ISBN 81-87981-42-3, p.207-8</ref>
{{quote|As regards the resting of the earth [...] this, too, is a dogma with the Hindu astronomers. Brahmagupta says in the ''Brahmasiddhānta'': "Some people maintain that the ''first'' motion (from east to west) does not lie in the meridian, but belongs to the earth. But Varāhamihira refutes them by saying: 'If that were the case, a bird would not return to its nest as soon as it had flown away from it towards the west.' And, in fact, it is precisely as Varāhamihira says.
Brahmagupta says in another place of the same book: "The followers of Aryabhata maintain that the earth is moving and heaven resting. People have tried to refute them by saying that, if such were the case, stones and trees would fall from the earth."
But Brahmagupta doe not agree with them, and says that that would not necessarily follow from their theory, apparently because he thought that all heavy things are attracted towards the center of the earth. He says: "On the contrary, if that were the case, ''the earth would not vie in keeping an even and uniform pace with the minutes of heaven, the prāṇas of the times.''"}}
===Nilakanthan model===
In 1500, [[Nilakantha Somayaji|Nilakanthan Somayaji]] (1444-1544) of the [[Kerala school of astronomy and mathematics]], in his ''[[Tantrasangraha]]'', 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=Joseph408>George G. Joseph (2000), p. 408.</ref>
Nilakanthan Somayaji, in his ''Aryabhatiyabhasya'', a commentary on Aryabhata's ''Aryabhatiya'', developed his own 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. Nilakantha's system, however, was mathematically more effient than the Tychonic system, due to correctly taking into account the equation of the centre and [[latitude|latitudinal]] motion of Mercury and Venus. Most astronomers of the [[Kerala school of astronomy and mathematics]] who followed him accepted his planetary model.<ref name=Joseph408/><ref>K. Ramasubramanian, M. D. Srinivas, M. S. Sriram (1994). "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>
== Calendars ==
{{see|Hindu calendar}}
In the Vedanga Jyotisa, the year begins with the winter solstice.<ref>Bryant 2001:253</ref> Hindu calendars have several [[calendar era|eras]]:
* The [[Hindu calendar]], counting from the start of the [[Kali Yuga]], has its epoch on [[18 February]] [[4th millennium BC|3102 BC]] Julian ([[23 January]] [[4th millennium BC|3102 BC]] Gregorian).
* The [[Vikrama Samvat]] calendar, introduced about the 12th century, counts from 56-57 BC,.
* The "[[Saka|Saka Era]]", used in some [[Hindu calendar]]s 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.<ref>Cunningham, A. 1883. A Book of Indian Eras.</ref>
==Interactions with foreign traditions==
===Hellenistic astronomy===
{{see also|Greek astronomy}}
[[Image:AiKhanoumSunDial.jpg|thumb|250px|Greek equatorial [[sun dial]], [[Ai-Khanoum]], [[Afghanistan]] 3rd-2nd century BCE.]]
[[Hellenistic civilization|Hellenistic]] astronomy is known to have been practiced near India in the [[Greco-Bactrian Kingdom|Greco-Bactrian]] city of [[Ai-Khanoum]] from the [[3rd century BCE]]. Various sun-dials, including an equatorial sundial adjusted to the latitude of [[Ujjain]] have been found in archaeological excavations there.<ref>"Afghanistan, les trésors retrouvés", p269</ref> Numerous interactions with the [[Mauryan Empire]], and the later expansion of the [[Indo-Greek Kingdom|Indo-Greeks]] into India suggest that some transmission may have happened during that period.<ref>"Les influences de l'astronomie grecques sur l'astronomie indienne auraient pu commencer de se manifester plus tot qu'on ne le pensait, des l'epoque Hellenistique en fait, par l'intermediaire des colonies grecques des Greco-Bactriens et Indo-Grecs" (French) Afghanistan, les trésors retrouvés", p269. Translation: "The influence of Greek astronomy on Indian astronomy may have taken place earlier than thought, as soon as the Hellenistic period, through the agency of the Greek colonies of the Greco-Bactrians and the Indo-Greeks.</ref>
Several Greco-Roman astrological treatises are also known to have been imported into India during the first few centuries of our era. Some say that the ''[[Yavanajataka]]'' ("astronomy of the Greeks") was translated from Greek to Sanskrit by [[Yavanesvara]] during the 2nd century CE, under the patronage of the [[Western Satrap]] [[Saka]] king [[Rudradaman I]but no original Greek book is available to substantiate this view. Actually the original text was the Sanskrit prose text composed by Mayasura, who was called Yavaneshvara. Sphuridhvaja during the time of the Satrapa king Rudradamana wrote it in Sanskrit in the verse form and called versified version as the Yavanajataka..
Later in the 6th century, the ''[[Romaka Siddhanta]]'' ("Doctrine of the Romans"), and the ''[[Paulisa Siddhanta]]'' ("Doctrine of [[Paulus Alexandrinus|Paul]]") were considered as two of the five main astrological treatises, which were compiled by [[Varahamihira]] in his ''Pañca-siddhāntikā'' ("Five Treatises").<ref>"the Pañca-siddhāntikā ("Five Treatises"), a compendium of Greek, Egyptian, Roman and Indian astronomy. Varāhamihira's knowledge of Western astronomy was thorough. In 5 sections, his monumental work progresses through native Indian astronomy and culminates in 2 treatises on Western astronomy, showing calculations based on Greek and Alexandrian reckoning and even giving complete Ptolemaic mathematical charts and tables. Encyclopedia Britanica Vol12, p269 [http://www.iranchamber.com/podium/history/030812_varahamihira_iranic_astronomer.php Source]</ref> Varahamihira wrote in the [[Brihat-Samhita]]: "The Greeks, though impure, must be honored since they were trained in sciences and therein, excelled others....."<ref>":Mleccha hi yavanah tesu samyak shastram idam sthitam
:Rsivat te api pujyante kim punar daivavid dvijah
:-(Brhatsamhita 2.15)</ref>
===Chinese astronomy===
{{see also|Chinese astronomy}}
The astronomical table of [[Trigonometric functions|sines]] by the [[Indian mathematics|Indian mathematician]] and astronomer, [[Aryabhata]], were translated into the Chinese mathematical book of the ''[[Treatise on Astrology of the Kaiyuan Era]]'' (''Kaiyuan Zhanjing''), compiled in 718 AD during the Tang Dynasty.<ref name="needham volume 3 109">[[Joseph Needham]], Volume 3, p. 109</ref>
The ''Kaiyuan Zhanjing'' was compiled by [[Gautama Siddha]], an astronomer and mathematician born in [[Chang'an]], and whose family was originally from India. He was also notable for his translation of the [[Navagraha]] calendar into [[Chinese language|Chinese]].
===Islamic astronomy===
{{see also|Islamic astronomy}}
Early [[Islamic astronomy]] was greatly influenced by Indian astronomy, particularly the ''[[Surya Siddhanta]]'' and the works of [[Aryabhata]] and [[Brahmagupta]], which were translated from [[Sanskrit]] into [[Arabic language|Arabic]]. These works were compiled as the ''Zij al-Sindhind'', based on the ''Surya Siddhanta'' and the works of Brahmagupta, which were translated by [[Muhammad al-Fazari]] and [[Yaqūb ibn Tāriq]] in 777. Sources indicate that the text was translated after an Indian astronomer visited the court of [[Caliph]] [[Al-Mansur]] in 770.
Fragments of texts during this period indicate that [[Arab]]s adopted the [[Trigonometric function|sine function]] (inherited from [[Indian mathematics|Indian trigonometry]]) instead of the [[chord]]s of [[Arc (geometry)|arc]] used in [[Greek mathematics|Hellenistic mathematics]].<ref name=Dallal162>{{Harv|Dallal|1999|p=162}}</ref> Another Indian influence was an approximate formula used for [[time]]keeping by Muslim astronomers.<ref>{{Harv|King|2002|p=240}}</ref>
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 [[Indian mathematics|Hindu computational]] techniques. While there appears to have been little concern for planetary theory, [[Muslim]] and [[Hindu]] astronomers in [[History of India|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, however, 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 in order to rival [[Ulugh Beg]]'s [[Samarkand]] observatory and in order to improve on the earlier Hindu computations in the ''[[Siddhanta]]s'' 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.<ref>{{citation|title=Sawai Jai Singh and His Astronomy|first=Virendra Nath|last=Sharma|year=1995|publisher=[[Motilal Banarsidass]] Publ.|isbn=8120812565|pages=8-9}}</ref><ref>{{citation|title=The Science of Empire: Scientific Knowledge, Civilization, and Colonial Rule in India|first=Zaheer|last=Baber|year=1996|publisher=[[State University of New York Press]]|isbn=0791429199|pages=82-9}}</ref>
The [[Seamlessness|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 [[globe]]s 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 [[wiktionary:seam|seams]], 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.<ref>{{citation|first=Emilie|last=Savage-Smith|title=Islamicate Celestial Globes: Their history, Construction, and Use|publisher=Smithsonian Institution Press, Washington, D.C.|year=1985}}</ref>
===European astronomy===
Through [[Islamic astronomy]], Indian astronomy had an influence on [[Europe]]an astronomy via [[Arabic language|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.<ref>G. G. Joseph, ''The Crest of the Peacock'', p. 306.</ref>
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.<ref name=almeida/> Kerala was in continuous contact with [[China]] and [[Arabia]], and [[Europe]]. The existence of [[circumstantial evidence]]<ref>C. K. Raju (2001). "Computers, Mathematics Education, and the Alternative Epistemology of the Calculus in the Yuktibhasa", ''Philosophy East and West'' '''51''' (3), p. 325-362.</ref> 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.<ref name=almeida>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.</ref>
Later in the early 18th century, [[Jai Singh II of Amber]] invited European [[Jesuit]] astronomers to his observatory, 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.<ref>{{citation|title=The Science of Empire: Scientific Knowledge, Civilization, and Colonial Rule in India|first=Zaheer|last=Baber|year=1996|publisher=[[State University of New York Press]]|isbn=0791429199|pages=89-90}}</ref>
== Terminology ==
{|
| valign="top" |
*aparapaska ([[full moon]] to [[new moon]] period)
*[[daksinayana]], pitryana: period when the sun moves south
*[[mahavrata]]: winter [[solstice]]
*naksatra-vidya, [[jyotisa]]: [[astronomy]]
| valign="top" |
*purvapaska (new moon to full moon period)
*[[uttarayana]]: period when sun moves north (winter to summer solstice)
*visuva: [[spring equinox]]
*visuvant: summer solstice
|}
=== Seasons ===
*madhu, madhava in vasanta: spring
*sukra, suci in grisma: summer
*nabha, nabhasya in varsa: rains
*isa, urja in sarada: autumn
*saha, sahasya in hemanta: winter
*tapa, tapasya in sisira: freeze
== See also ==
*[[History of astronomy]]
*[[Aryabhata]]
*[[Aryabhatiya]]
*[[Surya Siddhanta]]
*[[Yuga]]
*[[Indian mathematics]]
*[[Science and technology in ancient India]]
*[[Jyotish]] (Vedic astrology)
*[[Archaeoastronomy and Vedic chronology]]
*[[Hindu calendar]]
*[[Hindu units of measurement]]
*[[Hindu cosmology]]
*[[Chinese astronomy]]
*[[Islamic astronomy]]
==Notes==
{{reflist}}
==References==
;Editions of primary texts
*Ebenezer Burgess. "Surya-Siddhanta, Text with English Translation and Notes",Edited by S.Jain,Oriental Book Centre,Delhi,2005, ISBN 81-8315-017-9, pp.552 plus editorial 52 pages.
*Ebenezer Burgess. "Translation of the Surya-Siddhanta, a text-book of Hindu Astronomy", Journal of the American Oriental Society 6 (1860): 141–498.
*Surya Siddhānta,with Hindi commentary by Dr Rāmchandra Pāndey (Head of Department of {{IAST|Jyotiṣa}}, BHU University),Chowkhambā,Vārānasi.
*{{Citation
| last=Śāstri
| first=Hargovinda
| year=1978
| title={{IAST|Amarkoṣa}} with Hindi commentary
| place=Vārānasi
| publisher=Chowkhambā Sanskrit Series Office
| edition=
| isbn=
}}
* G.Thibaut and Sudhakar Dwivedi."Panchasiddhantika",Chowkhambha,Varanasi, India,1888,reprint 1997
* Gunākar Mule,Shruti-Smriti Paramparā and Ganitajna-Jyotishi Aryabhatta, published in Itihāsa,vol.3, Jan-Dec 1994, Research magagine of 'Indian Historical Research Council',35 Firoze Shah Road, New Delhi.
* Bhāskarāchārya, Siddhāntaśiromani, published by Chowkhambā Sanskrit Sansthāna, Vārānasi, 3rd reprint 1999.
* Burgess, Ebenezer (tr.) ''The Surya Siddhanta''. Delhi: [[Motilal Banarsidass]], 1989 (1860)
* Kuppanna Sastry, T.S., ''Vedanga Jyotisha of Lagadha''. Indian National Science Academy, Delhi 1985.
* Vidyalankara, V. ''Satapatha Brahmanastha Agnicayana Samiksa''. Bahalgarh, 1985.
* Rāmniwās Rāi, Āryabhatiya,with Hindi commentary, published by Indian National Science Academy, Bahādurshāh Zafar Mārg, New Delhi,1976 (published on the occasion of 1500th birth anniversary of Āryabhata).
;Secondary literature
*J.M. Roberts, The Hutchinson History of the World, BI Publications, 54 Janpath, New Delhi-1 (In association with Hutchinson Publishing Group of 3 Fitzroy Square, London W.1).
* Billard, R. ''L'Astronomie Indienne''. Ecole Francaise d'Extreme Orient, Paris, 1971.
*{{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]]
}}
* Duke, Dennis. 2005. "The Equant in India: The Mathematical Basis of Ancient Indian Planetary Models." ''Archive for History of Exact Sciences'' 59: 563–576[http://people.scs.fsu.edu/~dduke/india8.pdf].
* Filliozat, Jean. 1969. "Notes on Ancient Iranian and Indian Astronomy." ''Journal of the K.R. Cama Oriental Research Institute'' 42:100-135.
* [[Sri Yukteswar Giri]]. ''The holy science''. Los Angeles, Ca: Self-Realization Fellowship, 1984.
* Joseph, George G. (2000). ''The Crest of the Peacock: Non-European Roots of Mathematics'', 2nd edition. Penguin Books, London. ISBN 0691006598
* [[Subhash Kak|Kak, Subhash C.]] (2000). 'Birth and Early Development of Indian Astronomy'. In Selin, Helaine (2000). ''Astronomy Across Cultures: The History of Non-Western Astronomy'' (303-340). Kluwer, Boston. ISBN 0-7923-6363-9.
*{{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
}}
* Kramrisch, S. The Presence of Siva. Princeton University Press, Princeton 1981.
* Pingree, David (1978). "History of Mathematical astronomy in India." ''Dictionary of Scientific Biography'', vol. 15, pp. 533–633, New York: Charles Scribner's Sons.
* Pingree, David (1996). "Astronomy in India." in Christopher Walker, ed., ''Astronomy before the telescope'', pp. 123-142. London: British Museum Press. ISBN 0-7141-1746-3.
* Sen, S.N., and K.S. Shukla, eds. 1985. ''History of Astronomy in India''. New Delhi: Indian National Science Academy.
* Thurston, Hugh (1994). ''Early Astronomy''. Springer-Verlag, New York. ISBN 0-387-94107-X
* Nemichandra (Śāstri) Jain, Bhāratiya {{IAST|Jyotiṣa}}, published by Bhāratiya Jñānpith, New Delhi, 31rst reprint 2000, ISBN 81-263-0003-5.{{Verify credibility|date=September 2007}}
==External links==
*[http://cs.annauniv.edu/insight/insight/astro/introduc.htm Online course material for InSIGHT], a workshop on traditional Indian sciences for school children conducted by the Computer Science department of Anna University, Chennai, India.
*http://www.galileotelescope.com
*http://www.bharatvani.org/books/ait/ch22.htm
*http://www.sanskrit.org/Astronomy/Astronomy%20Index.htm
*http://www.jqjacobs.net/astro/aryabhata.html
*Bjorn Merker, [http://www.positiveatheism.org/india/s1990c12.htm Rig Veda Riddles In Nomad Perspective], Mongolian Studies, Journal of the Mongolian Society XI, 1988.
[[Category:Hindu astronomy|*]]
[[Category:Ancient astronomy]]
[[Category:History of astronomy]]
[[Category:History of astrology]]
[[id:Astronomi India]]