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Indian astronomy refers to the study of astronomy in the Indian subcontinent, as documented in literature spanning the Maurya (Vedanga Jyotisha, ca. 3rd century BCE) to the Mughal (such as the 16th century Kerala school) periods. The astronomy and the astrology of ancient India (Jyotisha) is mainly based on a sidereal system of calculations. A 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,[citation needed] and also in the Vedanga Jyotisha of Lagadha,[1] but not in subsequent systems, which have been sidereal. The first named authors writing treatises on astronomy were Yajnavalkya and Lagada before the Common Era, but authored treatises do not become common until 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 models, and possibly heliocentric models, in Indian astronomy, in contrast to the "Merucentric" astronomy of Puranic, Jaina and Buddhist traditions whose actual mathematics has been largely lost and only fabulous accounts remain.[citation needed]
[edit] Vedic period
Early Indian astronomy during the Vedic period, dated to the 2nd and 1st millenia BCE, was largely "Meru-centric", as described in the Puranic, Jaina and Buddhist traditions whose actual mathematics has been largely lost and only fabulous accounts remain. Belief in a flat Earth was common at this time. The only authors writing treatises on astronomy at the time that are known by name were Yajnavalkya, author of Shatapatha Brahmana, and Lagada, author of Vedanga Jyotisha. [edit] Controversies
Several writers have suggested that the concept of a spherical Earth may be implicit, though with ambiguity, in the Aitareya Brahmana, an ancient Indian philosophical text dating back to the early 1st millenium BC. One of the earliest writers to make this claim was Madame Blavatsky, who suggested that the "Serpent-Mantra" of the Aitareya Brahmana refers to the Earth (ilam) as the "Queen of the Serpents" (Sarpa-rajni) who initially had a bald head but grew hair as she became vegetated:[2]
Blavatsky has interpreted the "description of the earth in the shape of a round and bald head, which was soft at first, and became hard only from being breathed upon by the god Vayu, the lord of the air, forcibly suggests the idea that the authors of the sacred Vedic books knew the earth to be round or spherical".[2] Subhash Kak has interpreted another verse of the Aitareya Brahmana as suggesting that the Earth's rotation may be the cause of the apparent motion of the Sun rising and setting. He cites verse 4.18, which states:[3]
An alternative interpretation of the verse by Shyam Singh Shashi suggests that it may be referring to the Sun having a bright side in day and a dark side in night being the cause of its apparent rising and setting.[4]
According to theosophists, the earliest traces of a counter-intuitive idea that it is the Earth that is actually moving and the Sun that is at the center of the solar system, hence the concept of heliocentrism, may be found in several Vedic Sanskrit texts written in ancient India.[5][2] Yajnavalkya (c. 9th–8th century BC) believed that the Sun was "the center of the lokas" as described in the Vedas at the time. In his astronomical text Shatapatha Brahmana, he states:
Some interpret this to mean that the Sun is stationary, hence the Earth is moving around it,[2] though others are less clear about the meanings of the terms.[6] This would be elaborated in a later commentary Vishnu Purana (2.8) (c. 1st century BC).[3] Yajnavalkya recognized that the Sun was much larger than the Earth, which would have influenced this early heliocentric concept.[5] He also is said to have accurately measured the relative distances of the Sun and the Moon from the Earth as 108 times the respective diameters of these heavenly bodies, close to the modern measurements of 107.6 for the Sun and 110.6 for the Moon.[7] He described an accurate solar calendar in the Shatapatha Brahmana.[7] The Aitareya Brahmana (2.7) (c. 9th–8th century BC) also states: [edit] Siddhanta literatureWhile 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 Siddhantas (which means "established conclusions" [8] ). Varahamihira in his Pancha-Siddhantika contrasts five fo these: The Surya Siddhanta besides the Paitamaha Siddhantas (which is more similar to the "classical" Vedanga Jyotisha), the Paulisha and 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 [9] . Whitney's list of these siddhāntas are as follows according to four categories of Whitney [10]:
[edit] Coordinate systemIn Hindu Astronomy, the vernal equinox (the First Point of Aries) is often calculated at 23°From 0° Aries (1950 CE), i.e. about 7° Pisces.[11] The constellation that marks this vernal equinox is the Uttarabhadra.[citation needed] 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, 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.[citation needed] 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 Greeks.[12] The Hindus use a system of 27 or 28 Nakshatras (lunar constellations) to calculate a month. Each month can be divided into 30 lunar tithis (days). There are usually 360 or 366 days in a year.[citation needed] 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 or European traditions of astronomy till the work of Kepler, which was to come more than a hundred years later."[13] [edit] Computational planetary modelsThere 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" [14]. 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. [edit] Āryabhatan modelAryabhata (476–550), in his magnum opus Aryabhatiya, propounded a computational system based on a planetary model in which the Earth was taken to be rotating on its axis and the periods of the planets were given with respect to the Sun. Some have interpreted this to be a heliocentric model,[15][16][17] but this view has been disputed by others.[18][19][20] 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 and lunar eclipses, and the instantaneous motion of the Moon (expressed as a differential equation).[21][22] The first major astronomer to attack the Aryabhatiya was Varahamihira.[23] Brahmagupta was the greatest critic of Aryabhatiya; he devoted an entire chapter 'Tantra Parikshā' in his treatise Brāhm-Sphuta-Siddhānta to criticizng the Aryabhatiya in the harshest of terms.[24] 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.[25][26] 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,[27][28] before Copernicus had written De revolutionibus orbium coelestium. In 1030, 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:[29]
[edit] Nilakanthan modelIn 1500, Nilakanthan Somayaji (1444-1544) of the Kerala school of astronomy and mathematics, in his Tantrasangraha, revised Aryabhata's model for the planets Mercury and Venus. His equation of the centre for these planets remained the most accurate until the time of Johannes Kepler in the 17th century.[30] Nilakanthan Somayaji, in his Aryabhatiyabhasya, a commentary on Aryabhata's Aryabhatiya, developed his own computational system for a partially 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 latitudinal motion of Mercury and Venus. Most astronomers of the Kerala school of astronomy and mathematics who followed him accepted his planetary model.[30][31] [edit] Calendars
In the Vedanga Jyotisa, the year begins with the winter solstice.[32] Hindu calendars have several eras:
[edit] Interactions with foreign traditions[edit] Hellenistic astronomy
Hellenistic astronomy is known to have been practiced near India in the 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.[34] Numerous interactions with the Mauryan Empire, and the later expansion of the Indo-Greeks into India suggest that some transmission may have happened during that period.[35] 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 Paul") were considered as two of the five main astrological treatises, which were compiled by Varahamihira in his Pañca-siddhāntikā ("Five Treatises").[36] Varahamihira wrote in the Brihat-Samhita: "The Greeks, though impure, must be honored since they were trained in sciences and therein, excelled others....."[37] [edit] Chinese astronomy
The astronomical table of sines by the 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.[38] 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. [edit] 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. 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 Arabs adopted the sine function (inherited from Indian trigonometry) instead of the chords of arc used in Hellenistic mathematics.[39] Another Indian influence was an approximate formula used for timekeeping by Muslim astronomers.[40] 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, 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 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.[41][42] 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 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.[43] [edit] European astronomyThrough 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.[44] 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.[45] Kerala was in continuous contact with China and Arabia, and Europe. The existence of circumstantial evidence[46] 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.[45] 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.[47] [edit] Terminology
[edit] Seasons
[edit] See also
[edit] Notes
[edit] References
[edit] External links
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