Greek influence on Indian astronomy

Greek influence lies at the heart of Indian astronomy (and, unfortunately, astrology).

[By the way, anyone interested in the interaction between Greek and Indian thought, needs to read ‘The Shape of Ancient Thought‘, by Thomas McEvilly.]

In the words of the 6th century Indian astronomer and mathematician Varahamihira, “The Greeks, though impure, must be honored since they were trained in sciences and therein, excelled others…..” He is echoed by the Garga Samhita, which says: “The Yavanas are barbarians, yet the science of astronomy originated with them and for this they must be reverenced like gods.”

The influence began with the Alexandrian conquest of North Western influence, but continued throughout the Greco-Roman period, as several astronomical texts are known to have been translated into Sanskrit in the early centuries of our era.

The influence is apparent by looking at the founders of Indian astronomy (passages taken from Encyclopedia of Ancient Natural Scientists: The Greek Tradition and its Many Heirs):

Yavanesvara (149/150 CE)

“Anonymous author in 149/150 CE of a Sanskrit prose translation of an unidentified Greek (probably Alexandrian) text on horoscopy, a translation known only from the surviving Sanskrit verse version Yavanajataka composed by Sphujidhvaja in 269/270. The title Yavanesvara then meant literally “lord of the Greeks,” evidently a high position among the Greek residents of western India under the western Ksatrapa rulers in the Saka or Skuthian dominion of the area… His text as known through the Yavanajataka became the chief inspiration for Indian horoscopic astrology”

Sphujidhvaja (269/270 CE)

“Composed in 269/270 CE a Sanskrit verse adaptation, entitled Yavanajataka (YJ) or Greek Horoscopy, of a prose translation from Greek by an anonymous Yavanesvara (“lord of the Greeks”)… clearly reveals its Greek origin, including many transliterated Greek technical terms.”

Minaraja (ca 300 – 325 CE)

“Minaraja was a yavanadhiraja, i.e., person of authority in the settlements of Greeks under the western Ksatrapas in what is now Gujarat and Rajasthan in western India. He wrote a long astrological compendium, the Vr.ddhayavanajataka, covering every subject of astrology, in 71 chapters. The work is based on Sphujidhvaja’s Yavanajataka and a lost work of Satya..”

[text] Paitamahasiddhanta (ca 425 CE?)

“The extant form of the Paitamahasiddhanta still contains many of the basic features of classical Indian astronomy that were apparently derived from Hellenistic spherical astronomy models. These include large-integer period relations used to calculate mean celestial positions, planetary epicycles and equations for correcting mean positions on the assumption of circular orbits, and orbital sizes and geocentric distances. Their details reflect a rather chaotic mix of (among other things) Babylonian and Aristotelian notions invoked by various early Hellenistic theories that fell into oblivion after Ptolemy. Indian astronomers combined these concepts with other parameters and techniques in their astronomical tradition to produce the cosmological and computational models that became standard in siddhantas… appears to be the inspiration for much of the classical siddhanta tradition in Indian mathematical astronomy. The siddhanta is a standard treatise format that explains universal computations for all significant astronomical phenomena… The core siddhantas of the two earliest major schools or paksas of Indian astronomy (upon which the later schools are based) – namely, the Aryabhatiya of Aryabhata(ca 500 CE) in the Aryapaks.a and the Brahmasphutasiddhanta of Brahmagupta (628 CE) in the Brahmapaksa – both claim to follow a treatise of Brahma. Similarities in content strongly indicate this Paitamahasiddhanta as the treatise referred to in both cases. It is considered to be the founding text of the Brahmapaksa, although its original version has long been lost.”

Aryabhata (circa 500 AD)

“The planetary model used by Aryabhata is derived from a pre-Ptolemaic Greek model, which sought to preserve the Aristotelian principle of concentricity. The mean planet moves in a circle around the Earth, and centered around the mean planet are one or two epicycles, depending on whether the planet is one of the two luminaries or a star-planet. Pingree (DSB 15.590) believes that the mean motions of the planets in the Aryabhatıya, apparently unrelated to those of the Brahmapaksa, were derived from a Greek table of mean longitudes corresponding to noon on 21 March 499 CE.”

Varahamira (circa 550 AD)

“A descendant of Zoroastrian immigrants from Iran to India and a resident of the area near Ujjain, and a prolific writer, whose works cover all aspects of traditional Indian astrology and astronomy. His Pañcasiddhantika is a summary of five astronomical works current at his time, but now lost: the Paitamahasiddhanta, which expounds astronomy influenced by Mesopotamia… the Vasisthasiddhanta, the Paulisasiddhanta, the Romakasiddhanta and the Suryasiddhanta, which all expound Indian versions of Greco-Babylonian astronomy. The Pañcasiddhantika is an important work both in shedding light on the Indian astronomical tradition prior to 500 CE, and in recording pre-Ptolemaic Greek astronomy from which the Indian tradition borrowed. Varahamihira authored three works on divination… On genethlialogy, Varahamihira authored two works… both based on the Indian adaptation of Greek material in the works of Sphujidhvaja and others.”

Rise and Fall of Ancient Natural Science

From the Encyclopedia of Ancient Natural Scientists: The Greek Tradition and its Many Heirs. It’s a pretty awesome book, including something like 2,000 ancient natural scientists – obviously using a pretty loose definition of ‘natural scientist’. But they come up with these awesome graphs showing the rise and fall of the ancient natural scientists.

Because many of them had less certain date ranges, they spit them into two graphs, the ‘narrow-range’ with well known dates, and ‘wide-range’ for those whose dates were less exact.

The Antikythera Mechanism: