The flat earth theory

Flat Earth is an archaic and scientifically disproven conception of the Earth's shape as a plane or disk. Many ancient cultures subscribed to a flat-Earth cosmography.

The idea of a spherical Earth appeared in ancient Greek philosophy with Pythagoras (6th century BC). However, most pre-Socratics (6th–5th century BC) retained the flat-Earth model. In the early 4th century BC, Plato wrote about a spherical Earth. By about 330 BC, his former student Aristotle had provided strong empirical evidence for a spherical Earth. Knowledge of the Earth's global shape gradually began to spread beyond the Hellenistic world.[1][2][3][4] By the early period of the Christian Church, the spherical view was widely held, with some notable exceptions.

It is a historical myth that medieval Europeans generally thought the Earth was flat.[5] This myth was created in the 17th century by Protestants to argue against Catholic teachings.[6] Despite the scientific fact and obvious effects of Earth's sphericity, pseudoscientific[7] flat-Earth conspiracy theories are espoused by modern flat Earth societies and, increasingly, by unaffiliated individuals using social media.[8][9]

Belief in flat Earth

West Asia

In early Egyptian[10] and Mesopotamian thought, the world was portrayed as a disk floating in the ocean. A similar model is found in the Homeric account from the 8th century BC in which "Okeanos, the personified body of water surrounding the circular surface of the Earth, is the begetter of all life and possibly of all gods."[11]

Greece

Both Homer[17] and Hesiod[18] described a disc cosmography on the Shield of Achilles.[19][20] This poetic tradition of an Earth-encircling (gaiaokhos) sea (Oceanus) and a disc also appears in Stasinus of Cyprus,[21] Mimnermus,[22] Aeschylus,[23] and Apollonius Rhodius.[24]

East Asia

Further information: Chinese astronomy

In ancient China, the prevailing belief was that the Earth was flat and square, while the heavens were round,^[48] an assumption virtually unquestioned until the introduction of European astronomy in the 17th century.^[49][50][51] The English sinologist Cullen emphasizes the point that there was no concept of a round Earth in ancient Chinese astronomy:^[52]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.Illustration based on that of a 12th-century Asian cosmographerThe model of an egg was often used by Chinese astronomers such as Zhang Heng (78–139 AD) to describe the heavens as spherical:^[53]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.