Editing Flat Earth (section)

====East Asia====
{{Further|Chinese astronomy}}
In [[History of China#Ancient China|ancient China]], the prevailing belief was that the Earth was flat and square, while the heavens were round,<ref name="needham volume 3 498">{{cite book | last=Needham | first=J. | title=Science and Civilisation in China: Volume 3, Mathematics and the Sciences of the Heavens and the Earth | publisher=Cambridge University Press | year=1959 | isbn=978-0-521-05801-8 | url=https://books.google.com/books?id=jfQ9E0u4pLAC | page=498}}</ref> an assumption virtually unquestioned until the introduction of European astronomy in the 17th century.<ref name="Jean-Claude Martzloff 69">{{cite journal |last=Martzloff |first=Jean-Claude |date=1993–1994 |title=Space and Time in Chinese Texts of Astronomy and of Mathematical Astronomy in the Seventeenth and Eighteenth Centuries |url=https://www.eastm.org/index.php/journal/article/viewFile/526/457 |url-status=usurped |journal=Chinese Science |issue=11 |pages=66–92 [p. 69] |jstor=43290474 |archive-url=https://web.archive.org/web/20190907183516/http://www.eastm.org/index.php/journal/article/viewFile/526/457 |archive-date=2019-09-07 |access-date=2018-01-23}}</ref><ref name="Cullen on Needham">{{cite journal |last=Cullen |first=Christopher |date=1980 |title=Joseph Needham on Chinese Astronomy |journal=[[Past & Present (journal)|Past & Present]] |issue=87 |pages=39–53 [pp. 42, 49] |doi=10.1093/past/87.1.39 |jstor=650565}}</ref><ref>{{cite journal |last=Cullen |first=Christopher |date=1976 |title=A Chinese Eratosthenes of the Flat Earth: A Study of a Fragment of Cosmology in Huai Nan tzu 淮 南 子 |journal=Bulletin of the School of Oriental and African Studies |volume=39 |issue=1 |pages=106–27 [pp. 107–09] |doi=10.1017/S0041977X00052137|s2cid=171017315 }}</ref> The English [[Sinology|sinologist]] Cullen emphasizes the point that there was no concept of a round Earth in ancient Chinese astronomy:<ref name="Cullen">{{cite journal |first=Christopher |last=Cullen |title=A Chinese Eratosthenes of the Flat Earth: A Study of a Fragment of Cosmology in Huai Nan tzu 淮 南 子 |journal=Bulletin of the School of Oriental and African Studies |volume=39 |issue=1 |date=1976 |pages=106–27 [p. 107] |doi=10.1017/S0041977X00052137 |s2cid=171017315 }}</ref>
{{blockquote|Chinese thought on the form of the Earth remained almost unchanged from early times until the first contacts with modern science through the medium of [[Jesuit]] missionaries in the seventeenth century. While the heavens were variously described as being like an umbrella covering the Earth (the Kai Tian theory), or like a sphere surrounding it (the Hun Tian theory), or as being without substance while the heavenly bodies float freely (the Hsüan yeh theory), the Earth was at all times flat, although perhaps bulging up slightly.}}

[[File:Illustration of the Earthdisc floating out of the Water.jpg|thumb|Illustration based on that of a {{nowrap|12th-century}} Asian [[Cosmography|cosmographer]]]]
The model of an [[Egg (biology)|egg]] was often used by Chinese astronomers such as [[Zhang Heng]] (78–139&nbsp;AD) to describe [[Celestial sphere|the heavens]] as spherical:<ref name="needham">{{cite book |title=Science and Civilisation in China |last=Needham |first=Joseph |date=1959 |publisher=[[Cambridge University Press]] |isbn=978-0-521-05801-8 |volume=3 |page=219 |author-link=Joseph Needham}}</ref>
{{blockquote|The heavens are like a hen's egg and as round as a [[crossbow]] bullet; the Earth is like the yolk of the egg, and lies in the centre.}}

This analogy with a curved egg led some modern historians, notably [[Joseph Needham]], to conjecture that Chinese astronomers were, after all, aware of the Earth's sphericity. The egg reference, however, was rather meant to clarify the relative position of the flat Earth to the heavens:<ref name="Cullen on Needham"/>
{{blockquote|In a passage of Zhang Heng's cosmogony not translated by Needham, Zhang himself says: "Heaven takes its body from the Yang, so it is round and in motion. Earth takes its body from the Yin, so it is flat and quiescent". The point of the egg analogy is simply to stress that the Earth is completely enclosed by Heaven, rather than merely covered from above as the Kai Tian describes. Chinese astronomers, many of them brilliant men by any standards, continued to think in flat-Earth terms until the seventeenth century; this surprising fact might be the starting-point for a re-examination of the apparent facility with which the idea of a spherical Earth found acceptance in fifth-century BC Greece.}}

Further examples cited by Needham supposed to demonstrate dissenting voices from the ancient Chinese consensus actually refer without exception to the Earth being square, not to it being flat.<ref name="Cullen"/> Accordingly, the 13th-century scholar [[Li Zhi (mathematician)|Li Ye]], who argued that the movements of the round heaven would be hindered by a square Earth,<ref name="needham volume 3 498"/> did not advocate a spherical Earth, but rather that its edge should be rounded off so as to be circular.<ref name="Cullen"/> However, Needham disagrees, affirming that Li Ye believed the Earth to be spherical, similar in shape to the heavens but much smaller.<ref>Needham, Joseph; Wang, Ling. (1995) [1959]. ''Science and Civilization in China: Mathematics and the Sciences of the Heavens and the Earth'', vol. 3, reprint edition. Cambridge: Cambridge University Press. {{ISBN|0-521-05801-5}}, p. 498.</ref> This was preconceived by the 4th-century scholar [[Yu Xi]], who argued for [[Static universe|the infinity]] of [[outer space]] surrounding the Earth and that the latter could be either square or round, in accordance to the shape of the heavens.<ref>Needham, Joseph; Wang, Ling. (1995) [1959]. ''Science and Civilization in China: Mathematics and the Sciences of the Heavens and the Earth'', vol. 3, reprint edition. Cambridge: Cambridge University Press. {{ISBN|0-521-05801-5}}, pp. 220, 498.</ref> When Chinese geographers of the 17th century, influenced by European cartography and astronomy, showed the Earth as a sphere that could be [[Circumnavigation|circumnavigated]] by sailing around the globe, they did so with formulaic terminology previously used by Zhang Heng to describe the spherical shape of the Sun and Moon (i.e. that they were as round as a crossbow bullet).<ref>Needham, Joseph; Wang, Ling. (1995) [1959]. ''Science and Civilization in China: Mathematics and the Sciences of the Heavens and the Earth'', vol. 3, reprint edition. Cambridge: Cambridge University Press. {{ISBN|0-521-05801-5}}, pp. 227, 499.</ref>

As noted in the book ''[[Huainanzi]]'',<ref>Joseph Needham, p. 225.</ref> in the 2nd century BC, Chinese astronomers effectively inverted [[Eratosthenes]]' calculation of the curvature of the Earth to calculate the height of the Sun above the Earth. By assuming the Earth was flat, they arrived at a distance of {{val|100,000|u=''[[Li (unit)|li]]''}} (approximately {{val|200,000|u=km}}). The ''[[Zhoubi Suanjing]]'' also discusses how to determine the distance of the Sun by measuring the length of noontime shadows at different latitudes, a method similar to Eratosthenes' measurement of the circumference of the Earth, but the ''Zhoubi Suanjing'' assumes that the Earth is flat.<ref>{{cite book |title=Adversaries and Authorities: Investigations into ancient Greek and Chinese science |last=Lloyd |first=G. E. R. |publisher=[[Cambridge University Press]] |year=1996 |isbn=978-0-521-55695-8 |place=Cambridge |pages=59–60 |author-link=G. E. R. Lloyd}}</ref>