Flat Earth

For other uses, see Flat Earth (disambiguation).

The Flammarion engraving (1888) depicts a traveller who arrives at the edge of a flat Earth and sticks his head through the firmament.

15th century adaptation of a T and O map. This kind of medieval mappa mundi illustrates only the reachable side of a round Earth, since it was thought that no one could cross a torrid clime near the equator to the other half of the globe.

The Flat Earth model is a view that the Earth's shape is a flat plane or disk. Most ancient cultures have had conceptions of a flat Earth, including Greece until the classical period, the Bronze Age and Iron Age civilizations of the Near East until the Hellenistic period, India until the Gupta period (early centuries AD) and China until the 17th century. It was also typically held in the aboriginal cultures of the Americas, and a flat Earth domed by the firmament in the shape of an inverted bowl is common in pre-scientific societies.

The paradigm of a spherical Earth was developed in Greek astronomy, beginning with Pythagoras (6th century BC), although most Pre-Socratics retained the flat Earth model. Aristotle accepted the spherical shape of the Earth on empirical grounds around 330 BC, and knowledge of the spherical Earth gradually began to spread beyond the Hellenistic world from then on.

The misconception that educated people at the time of Columbus believed in a flat Earth, and that his voyages refuted that belief, has been referred to as "The Myth of the Flat Earth". In 1945, it was listed by the Historical Association (of Britain) as the second of 20 in a pamphlet on common errors in history.

Historical development

Ancient Near East

Imago Mundi Babylonian map, the oldest known world map, 6th century BCE Babylonia.

In early Egyptian and Mesopotamian thought the world was portrayed as a flat disk floating in the ocean. A similar model is found in the Homeric account of the 8th century BCE 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."

The Hebrew Bible carried forward the ancient Middle Eastern cosmology, such as in the Enuma Elish, which described a circular earth with a solid roof, surrounded by water above and below, as illustrated by references to the "foundations of the earth" and the "circle of the earth" in the following examples:

• "He sits enthroned above the circle of the earth, and its people are like grasshoppers. He stretches out the heavens like a canopy, and spreads them out like a tent to live in."
• "For the foundations of the earth are the LORD's; upon them he has set the world."
• "You shall not make for yourself a carved image, or any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth."

There are isolated quotations which can be taken as evidence of something different:

• "He spreads out the northern skies over empty space; he suspends the earth over nothing."

but these are complicated by references to "pillars of the heavens" in subsequent stanzas.

Classical world

Possible rendering of Anaximander's world map

Poets

Both Homer and Hesiod described a flat disc cosmography on the shield of Achilles.

This poetic tradition of a earth-encircling (gaiaokhos) sea (Oceanus) and a flat disc also appears in Stasinus of Cyprus, Mimnermus, Aristophanes, and Apollonius Rhodius.

Homer's description of the flat disc cosmography on the shield of Achilles with the encircling ocean is also found repeated far later in Quintus Smyrnaeus’ Posthomerica (4th century AD) which continues the narration of the Trojan War.

Philosophers

Many pre-Socratic philosophers considered the world to be flat, at least according to Aristotle. According to Aristotle, pre-Socratic philosophers, including Leucippus (c. 440 BC) and Democritus (c. 460–370 BC) believed in a flat Earth. Anaximander (c. 550 BC) believed the Earth to be a short cylinder with a flat, circular top that remained stable because it is the same distance from all things. Anaximenes of Miletus believed that "the earth is flat and rides on air; in the same way the sun and the moon and the other heavenly bodies, which are all fiery, ride the air because of their flatness." Xenophanes of Colophon (c. 500 BC) thought that the Earth was flat, with its upper side touching the air, and the lower side extending without limit. Belief in a flat Earth continued into the 5th-century BC. Anaxagoras (c. 450 BC) agreed that the Earth was flat, and his pupil Archelaus believed that the flat Earth was depressed in the middle like a saucer, to allow for the fact that the Sun does not rise and set at the same time for everyone.

Ancient India

Further information: Indian astronomy

In antiquity, a cosmological view prevailed in India that held the Earth is a disc that consists of four continents grouped around the central mountain Meru like the petals of a flower. An outer ocean surrounds these continents. This view was elaborated in traditional Jain cosmology and Buddhist cosmology, which depicts the world (in this case solar system/universe and not Earth) as a vast, flat oceanic disk (of the magnitude of a small planetary system), bounded by mountains, in which the continents are set as small islands. The belief in a disk remained the dominant one in Indian cosmology until the early centuries AD, such as in the Puranas:

In the Puranas the Earth is a flat-bottomed, circular disk, in the center of which is a lofty mountain, Meru.

Norse and Germanic

The ancient Norse and Germanic peoples believed in a flat earth cosmography of the earth surrounded by an ocean, with the axis mundi (a world-tree: Yggdrasil, or pillar: Irminsul) in the centre. The Norse believed that the in the world-encircling ocean sat a snake called Jormungandr. In the Norse creation account preserved in Gylfaginning (VIII) it is stated that during the creation of the earth, an impassable sea was placed around the earth like a ring:

...And Jafnhárr said: "Of the blood, which ran and welled forth freely out of his wounds, they made the sea, when they had formed and made firm the earth together, and laid the sea in a ring round. about her; and it may well seem a hard thing to most men to cross over it."

Ancient China

Further information: Chinese astronomy

In ancient China, the prevailing belief was that the Earth was flat and square, while the heavens were round, an assumption virtually unquestioned until the introduction of European astronomy in the 17th century. The English sinologist Cullen emphasizes the point that there was no concept of a round Earth in ancient Chinese astronomy:

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.

The model of an egg is often used by Chinese astronomers to describe the heavens as spherical. Historian Joseph Needham quotes Zhang Heng (78-139 AD) as saying:

The heavens are like a hen's egg and as round as a crossbow bullet; the earth is like the yoke of the egg, and lies in the centre.

The Yu Ji Tu, "Map of the Tracks of Yu", carved into stone in 1137, located in the Stele Forest of Xi'an. This 3 ft (0.91 m) squared map features a grid of 100 li squares. China's coastline and river systems are clearly defined and accurately positioned on the map. See Chinese geography

Zhang Heng is better known for his invention of the rectangular grid or coordinate system that was used for terrestrial maps in the same way as Marinus of Tyre and Ptolemy, who were contemporaries. Cullen comments:

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 B.C. Greece.

Likewise, the 13th century scholar Li Ye, arguing that the movements of the round heaven would be hindered by a square Earth, did not advocate a spherical Earth, but rather that its edge should be rounded off so as to be circular.

As noted in the book Huai Nan Zu, in the 2nd Century BC Chinese astronomers effectively inverted Eratosthenes' calculation of the curvature of the earth in order to calculate the height of the sun above the earth. By assuming the earth to be flat, they arrived at a distance of 100,000 li, a value short by three orders of magnitude.

Decline of the Flat Earth model

Further information: Spherical Earth and History of geodesy

Classical world

When a ship is at the horizon, its lower part is obscured due to the sphericity of the Earth.

It has been suggested that seafarers probably provided the first observational evidence that the Earth was not flat. Greek thalassocracy was receptive to the idea, unlike the Chinese, whose cosmology was firmly land-based.

Semi-circular shadow of Earth on the Moon during the phases of a lunar eclipse

Some ancient authorities in the doxographic tradition credited the Greek philosophers Pythagoras, in the 6th century BC, and Parmenides, in the 5th, with recognizing that the Earth is spherical.

Around 330 BC, Aristotle provided observational evidence for the spherical Earth.

The Earth's circumference was first determined around 240 BC by Eratosthenes. Eratosthenes knew that in Syene, in Egypt, the Sun was directly overhead at the summer solstice, while he estimated that the angle formed by a shadow cast by the Sun at Alexandria was 1/50th of a circle. He estimated the distance from Syene to Alexandria as 5,000 stades, and estimated the Earth's circumference was 250,000 stades. Subsequently, ignorance of the size of a stadia caused problems both to the Arabs and to Christopher Columbus.

The Terrestrial Sphere of Crates of Mallus (ca. 150 B.C.).

In the 2nd century BC, Crates of Mallus devised a terrestrial sphere which divided the Earth into four continents, separated by great rivers or oceans, with people presumed to be living in each of the four regions. Opposite the oikumene, the inhabited world, were the antipodes, considered unreachable both because of an intervening torrid zone (equator) and the ocean. This took a strong hold on the medieval mind.

Lucretius (1st. c. BC) opposed the concept of a spherical Earth, because he considered that in an infinite universe there was no center towards which heavy bodies would tend, thus he considered the idea of animals walking around topsy-turvy under the Earth to be absurd. But by the 1st century AD, Pliny the Elder was in a position to claim that everyone agrees on the spherical shape of Earth, although there continued to be disputes regarding the nature of the antipodes, and how it is possible to keep the ocean in a curved shape. Pliny also considers the possibility of an imperfect sphere, "shaped like a pinecone".

Ptolemy derived his maps from a curved globe and developed the system of latitude, longitude, and climes. His Almagest was written in Greek and only translated into Latin in the 11th century from Arabic translations. But once it was known, it remained the basis of European astronomy throughout the Middle Ages.

In late antiquity such widely read encyclopedists as Macrobius (4th c.) and Martianus Capella (5th c.) discussed the circumference of the sphere of the Earth, its central position in the universe, the difference of the seasons in northern and southern hemispheres, and many other geographical details. In his commentary on Cicero's Dream of Scipio, Macrobius described the Earth as a globe of insignificant size in comparison to the remainder of the cosmos.

The Talmud

The Jerusalem Talmud says that Alexander of Macedon (Alexander the Great) was lifted by birds to the point that he saw the curvature of the Earth. This story is mentioned as well by the Tosafos commentary on the Babylonian Talmud. This is used to explain why a statue of a person holding a sphere in his hand is assumed to be an idol. The sphere being held in its hand symbolizing the idol's purported dominion over the world whose shape is a sphere.

Early Christian Church

From Late Antiquity, and from the beginnings of Christian theology, knowledge of the sphericity of the Earth had become widespread. There was considerable misunderstanding illustrated by the debate concerning the possibility of the inhabitants of the antipodes:

After his conversion to Christianity, Lactantius (245–325) became the tutor to the son of emperor Constantine and a trenchant critic of all pagan philosophy. In Book III of The Divine Institutes he ridicules the notion that there could be inhabitants of the antipodes "whose footsteps are higher than their heads". After presenting some arguments which he attributes to advocates for a spherical heaven and Earth, he writes:

But if you inquire from those who defend these marvellous fictions, why all things do not fall into that lower part of the heaven, they reply that such is the nature of things, that heavy bodies are borne to the middle, and that they are all joined together towards the middle, as we see spokes in a wheel; but that the bodies that are light, as mist, smoke, and fire, are borne away from the middle, so as to seek the heaven. I am at a loss what to say respecting those who, when they have once erred, consistently persevere in their folly, and defend one vain thing by another;

Though he was not a theologian, his books remained widely read and admired and were among those printed first in the fifteenth century.

Saint Augustine (354–430) took a more cautious approach in arguing against assuming that people inhabited the antipodes:

But as to the fable that there are Antipodes, that is to say, men on the opposite side of the earth, where the sun rises when it sets to us, men who walk with their feet opposite ours that is on no ground credible. And, indeed, it is not affirmed that this has been learned by historical knowledge, but by scientific conjecture, on the ground that the earth is suspended within the concavity of the sky, and that it has as much room on the one side of it as on the other: hence they say that the part that is beneath must also be inhabited. But they do not remark that, although it be supposed or scientifically demonstrated that the world is of a round and spherical form, yet it does not follow that the other side of the earth is bare of water; nor even, though it be bare, does it immediately follow that it is peopled.

Since these people would have to be descended from Adam, they would have had to travel to the other side of the Earth at some point; Augustine continues:

It is too absurd to say, that some men might have taken ship and traversed the whole wide ocean, and crossed from this side of the world to the other, and that thus even the inhabitants of that distant region are descended from that one first man.

Scholars of Augustine's work have traditionally understood him to have shared the common view of his educated contemporaries that the Earth is spherical, in line with the quotation above, and with Augustine's famous endorsement of science in De Genesi ad litteram. That tradition has, however, recently been challenged by Leo Ferrari, who concluded that many of Augustine's passing references to the physical universe imply a belief in an essentially flat Earth "at the bottom of the universe".

The notion that hell was below the earth is stated clearly in early Christian tradition by the belief, still recited by most Christians in the Apostolic and Athanasian creeds, that Christ "descended into hell" between his death and resurrection. The Harrowing of hell, combined with the theme of Christ's ascension into heaven, became a favourite motif in medieval art and drama and led to the three tiers of the mystery plays. This was possibly the only source of cosmology available to most unlearned people until literacy became more widespread after the invention of printing.

Cosmas Indicopleustes' world picture - flat earth in a Tabernacle.

Diodorus of Tarsus (d. 394) may have argued for a flat Earth based on scriptures; however, Diodorus' opinion on the matter is known to us only by a criticism of it by Photius. Severian, Bishop of Gabala (d. 408), wrote that the Earth is flat and the sun does not pass under it in the night, but "travels through the northern parts as if hidden by a wall". The Egyptian monk Cosmas Indicopleustes (547) in his Topographia Christiana, where the Covenant Ark was meant to represent the whole universe, argued on theological grounds that the Earth was flat, a parallelogram enclosed by four oceans.

In his Homilies Concerning the Statutes St.John Chrysostom (344–408) explicitly espoused the idea, based on his reading of Scripture, that the Earth floated on the waters gathered below the firmament, and St. Athanasius (c.293–373) expressed similar views in Against the Heathen.

A very recent essay by Leone Montagnini, discussing the question of the shape of the Earth from the origins to the late Antiquity, has shown that the Fathers of the Church shared different approaches that paralleled their overall philosophical and theological visions. Those of them who were more close to Platonic visions, like Origen, shared peacefully the geosphericism. A second tradition, including Basil, Ambrose and Augustine, but also Philoponus, accepted the idea of the round Earth and the radial gravity, but in a critical way. In particular they pointed out a number of doubts about the physical reasons of the radial gravity, and hesitated in accepting the physical reasons proposed by Aristotle or Stoicism. However, a "flattist" approach was more or less shared by all the Fathers coming from the Syriac area, who were more inclined to follow the letter of the Old Testament. Diodorus, Severian, and Cosmas Indicopleustes, but also Chrysostom, belonged just to this latter tradition.

At least one early Christian writer, Basil of Caesarea (329–379), believed the matter to be theologically irrelevant.

Early Middle Ages

9th century Macrobian cosmic diagram showing the sphere of the Earth at the center, (globus terrae)

With the end of Roman civilization, Western Europe entered the Middle Ages with great difficulties that affected the continent's intellectual production. Most scientific treatises of classical antiquity (in Greek) were unavailable, leaving only simplified summaries and compilations. Still, many textbooks of the Early Middle Ages supported the sphericity of the Earth. For example: some early medieval manuscripts of Macrobius include maps of the Earth, including the antipodes, zonal maps showing the Ptolemaic climates derived from the concept of a spherical Earth and a diagram showing the Earth (labeled as globus terrae, the sphere of the Earth) at the center of the hierarchically ordered planetary spheres. Further examples of such medieval diagrams can be found in medieval manuscripts of the Dream of Scipio. In the Carolingian era, scholars discussed Macrobius's view of the antipodes. One of them, the Irish monk Dungal, asserted that the tropical gap between our habitable region and the other habitable region to the south was smaller than Macrobius had believed.

12th century T and O map representing the inhabitated world as described by Isidore of Seville in his Etymologiae. (chapter 14, de terra et partibus).

Europe's view of the shape of the Earth in Late Antiquity and the Early Middle Ages may be best expressed by the writings of early Christian scholars:

• Boethius (c. 480 – 524), who also wrote a theological treatise On the Trinity, repeated the Macrobian model of the Earth as an insignificant point in the center of a spherical cosmos in his influential, and widely translated, Consolation of Philosophy.
• Bishop Isidore of Seville (560 – 636) taught in his widely read encyclopedia, the Etymologies, that the Earth was round and "resembles a wheel". Resembling Anaximander in language and the map that he provided, this was widely interpreted as referring to a flat disc-shaped Earth though some recent writers believe that he recognized the Earth to be globular. He did not admit the possibility of antipodes, which he took to mean people dwelling on the opposite side of the Earth, considering them to be legendary and noting that there was no evidence for their existence. "The work remained unsurpassed until the thirteenth century and was regarded as the summit of all knowledge. It became an essential part of European medieval culture. Soon after the invention of typography it appeared many times in print." Isidore's disc-shaped map, essentially unchanged from its predecessors of 1,200 years previously, continued to be used through the Middle Ages by authors, e.g. the 9th century bishop Rabanus Maurus who compared the habitable part of the northern hemisphere (Aristotle's northern temperate clime) with a wheel.

Isidore's portrayal of the five zones of the earth

An illustration from Isidore's De Natura Rerum shows the five zones of the earth as adjacent circles showing that he had no conception of a spherical earth. The text confirms that he thought the Arctic and Antarctic zones to be adjacent to each other.

• The monk Bede (c.672 – 735) wrote in his influential treatise on computus, The Reckoning of Time, that the Earth was round ('not merely circular like a shield [or] spread out like a wheel, but resembl[ing] more a ball'), explaining the unequal length of daylight from "the roundness of the Earth, for not without reason is it called 'the orb of the world' on the pages of Holy Scripture and of ordinary literature. It is, in fact, set like a sphere in the middle of the whole universe." (De temporum ratione, 32). The large number of surviving manuscripts of The Reckoning of Time, copied to meet the Carolingian requirement that all priests should study the computus, indicates that many, if not most, priests were exposed to the idea of the sphericity of the Earth. Ælfric of Eynsham paraphrased Bede into Old English, saying "Now the Earth's roundness and the Sun's orbit constitute the obstacle to the day's being equally long in every land."
• St Vergilius of Salzburg (c.700 – 784), in the middle of the eighth century, discussed or taught some geographical or cosmographical ideas which St Boniface found sufficiently objectionable that he complained about them to Pope Zachary. The only surviving record of the incident is contained in Zachary's reply, dated 748, where he wrote:

"As for the perverse and sinful doctrine which he (Virgil) against God and his own soul has uttered—if it shall be clearly established that he professes belief in another world and other men existing beneath the earth, or in (another) sun and moon there, thou art to hold a council, deprive him of his sacerdotal rank, and expel him from the Church."

Some authorities have suggested that the sphericity of the Earth was among the aspects of Vergilius's teachings which Boniface and Zachary had considered objectionable. Others have considered this unlikely, and take the wording of Zachary's response to indicate at most an objection to belief in the existence of humans living in the antipodes. In any case, there is no record of any further action having been taken against Vergilius. He was later appointed bishop of Salzburg, and was canonised in the 13th century.

12th century depiction of a spherical Earth with the four seasons (book "Liber Divinorum Operum" by Hildegard of Bingen)

A possible non-literary but graphic indication that people in the Middle Ages believed that the Earth (or perhaps the world) was a sphere, is the use of the orb (globus cruciger) in the regalia of many kingdoms and of the Holy Roman Empire. It is attested from the time of the Christian late-Roman emperor Theodosius II (423) throughout the Middle Ages; the Reichsapfel was used in 1191 at the coronation of emperor Henry VI. However the word 'orbis' means 'circle' and there is no record of a globe as a representation of the Earth since ancient times in the west till that of Martin Behaim in 1492. Additionally it could well be a representation of the entire 'world' or cosmos.

A recent study of medieval concepts of the sphericity of the Earth noted that "since the eighth century, no cosmographer worthy of note has called into question the sphericity of the Earth." However, the work of these intellectuals may not have had significant influence on public opinion, and it is difficult to tell what the wider population may have thought of the shape of the Earth, if they considered the question at all.

High and Late Middle Ages

Further information: Spherical Earth § Medieval Europe

Picture from a 1550 edition of On the Sphere of the World, the most influential astronomy textbook of 13th century Europe.

By the 11th century Europe had learned of Islamic astronomy. The Renaissance of the 12th century from about 1070 started an intellectual revitalization of Europe with strong philosophical and scientific roots, and increased interest in natural philosophy.

Illustration of the spherical Earth in a 14th century copy of L'Image du monde (ca. 1246).

Hermannus Contractus (1013–1054) was among the earliest Christian scholars to estimate the circumference of Earth with Eratosthenes' method. Thomas Aquinas (1225–1274), the most important and widely taught theologian of the Middle Ages, believed in a spherical Earth; and he even took for granted his readers also knew the Earth is round. Lectures in the medieval universities commonly advanced evidence in favor of the idea that the Earth was a sphere. Also, "On the Sphere of the World", the most influential astronomy textbook of the 13th century and required reading by students in all Western European universities, described the world as a sphere. Thomas Aquinas, in his Summa Theologica, wrote, "The physicist proves the earth to be round by one means, the astronomer by another: for the latter proves this by means of mathematics, e.g. by the shapes of eclipses, or something of the sort; while the former proves it by means of physics, e.g. by the movement of heavy bodies towards the center, and so forth."

The shape of the Earth was not only discussed in scholarly works written in Latin; it was also treated in works written in vernacular languages or dialects and intended for wider audiences. The Norwegian book Konungs Skuggsjá, from around 1250, states clearly that the Earth is round - and that there is night on the opposite side of the Earth when there is daytime in Norway. The author also discusses the existence of antipodes - and he notes that they (if they exist) will see the Sun in the north of the middle of the day, and that they will have opposite seasons of the people living in the Northern Hemisphere.

However Tattersall shows that in many vernacular works in 12th and 13th century French texts the Earth was considered "round like a table" rather than "round like an apple". "In virtually all the examples quoted...from epics and from non-'historical' romances (that is, works of a less learned character) the actual form of words used suggests strongly a circle rather than a sphere.

Portuguese exploration of Africa and Asia, Columbus's voyage to the Americas (1492) and finally Ferdinand Magellan's circumnavigation of the Earth (1519–21) provided the final, practical proofs for the global shape of the Earth.

Ancient India

The idea of a spherical Earth surrounded by the spheres of planets was finally introduced into India during the early centuries AD through the reception of Greek astronomy. Key parts of traditional Indian astronomy, heavily attacked by progressive Indian astronomers, were discarded, while others were attempted to be adapted to the new paradigm. Thus, the circumference of the Indian disk of the Earth was modelled into the equator of the Greeks.

The works of the classical Indian astronomer and mathematician, Aryabhata (476-550 AD), deal with the sphericity of the Earth and the motion of the planets. The final two parts of his Sanskrit magnum opus the Aryabhatiya, which were named the Kalakriya ("reckoning of time") and the Gola ("sphere"), state that the Earth is spherical and that its circumference is 4,967 yojanas, which in modern units is 39,968 km (24,835 mi), which is close to the current equatorial value of 40,075 km (24,901 mi).

Islamic world

Further information: Spherical Earth § Medieval Islamic scholars

In the 9th century Abbasid Caliphate, most of the Greek works of cosmology from Constantinople, including Aristotle's De caelo and Ptolemy's Almagest were translated into Arabic in the House of Wisdom in Baghdad. Some Islamic scholars adopted from Greek astronomy the ideas that the Earth was spherical (Spherical Earth) and at the center of the universe (Geocentric model), that the universe was without void spaces and mainly divided into the wider planetary space composed of the Four Elements on the one hand, and the celestial space beginning from the moon and extending to the edge of the universe on the other. By the time they were re-exported back to Europe they had been enriched by spherical trigonometry, which they used in these calculations and the Arabic numeral system.

Muslim scholars who held to the round Earth theory used it for a quintessentially Islamic purpose: to calculate the distance and direction from any given point on the Earth to Makkah (Mecca). This determined the Qibla, or Muslim direction of prayer.

A terrestrial globe (Kura-i-ard) was among the presents sent by the Persian Muslim astronomer Jamal-al-Din to Kubla Khan in 1267. It was made of wood on which "seven parts of water are represented in green, three parts of land in white, with rivers, lakes etc." Ho Peng Yoke remarks that "it did not seem to have any general appeal to the Chinese in those days".

The Quran mentions that the world was "laid out" or "spread out". Surat Al-Ghashiya 88:18-19 reads "Do they never reflect on .. the heaven, how it was raised on high? The mountains, how they were set down? The earth, how it was made flat?". To this the classic Sunni commentary Tafsir al-Jalalayn (1505) says "As for His words sutihat, ‘laid out flat’, this on a literal reading suggests that the earth is flat, which is the opinion of most of the scholars of the [revealed] Law, and not a sphere as astronomers (ahl al-hay’a) have it, even if this [latter] does not contradict any of the pillars of the Law." Other translations render "made flat" as "spread out".

Ming China

As late as 1595, the first Jesuit missionary to China, Matteo Ricci, recorded that the Chinese say: "The earth is flat and square, and the sky is a round canopy; they did not succeed in conceiving the possibility of the antipodes". The universal belief in a flat Earth is confirmed by a contemporary Chinese encyclopedia from 1609 illustrating a flat Earth extending over the horizontal diametral plane of a spherical heaven.

In the 17th century, the idea of a spherical Earth spread in China due to the influence of the Jesuits, who held high positions as astronomers at the imperial court. The Ge Chi Cao treatise of Xiong Ming-yu (1648) showed a printed picture of the Earth as a spherical globe, with the text stating that "the round earth certainly has no square corners". The text also pointed out that sailing ships could return to their port of origin after circumnavigating the waters of the Earth.

The influence of the map is distinctly Western, as traditional maps of Chinese cartography held the graduation of the sphere at 365.25 degrees, while the Western graduation was of 360 degrees. Also of interest to note is on one side of the world, there is seen towering Chinese pagodas, while on the opposite side (upside-down) there were European cathedrals. Western influence of geographical knowledge was used by Xiong to enforce what he believed had already been argued by earlier Chinese astronomers. However, the French sinologist Jean-Claude Martzloff regards this as a retrospective interpretation:

European astronomy was so much judged worth consideration that numerous Chinese authors developed the idea that the Chinese of antiquity had anticipated most of the novelties presented by the missionaries as European discoveries, for example, the rotundity of the earth and the “heavenly spherical star carrier model.” Making skillful use of philology, these authors cleverly reinterpreted the greatest technical and literary works of Chinese antiquity. From this sprang a new science wholly dedicated to the demonstration of the Chinese origin of astronomy and more generally of all European science and technology.

Modern period

"Myth of the Flat Earth" in modern historiography

Main article: Myth of the Flat Earth

Martin Behaim's Erdapfel, the oldest surviving terrestrial globe and finished before the news of the discovery of the Americas had reached Europe (1492), demonstrates that knowledge of the round Earth was common on the continent before.

During the 19th century, the Romantic conception of a European "Dark Age" gave much more prominence to the Flat Earth model than it ever possessed historically.

In 1945 the Historical Association listed "Columbus and the Flat Earth Conception" second of twenty in its first-published pamphlet on common errors in history.

This belief is even repeated in some widely read textbooks. Previous editions of Thomas Bailey's The American Pageant stated that "The superstitious sailors [of Columbus' crew]  ... grew increasingly mutinous...because they were fearful of sailing over the edge of the world"; however, no such historical account is known. Actually, sailors were probably among the first to know of the curvature of Earth from everyday observations, for example seeing how mountains vanish below the horizon on sailing far from shore.

Some historians consider that the early advocates who projected flat Earth upon Christians of the Middle Ages were highly influential (19th century view typified by Andrew Dickson White); current historians (late 20th century view typified by historian and religious studies scholar Jeffrey Burton Russell) have asserted that White's and other writings projecting flat Earth belief upon Christians are inaccurate, citing centuries of theological writings, and suggested the motivations for the promotion of such inaccuracies.

According to Russell, the common misconception that people before the age of exploration believed that Earth was flat entered the popular imagination after Washington Irving's publication of A History of the Life and Voyages of Christopher Columbus in 1828. Although some of the arguments attributed by Irving to Columbus's opponents had been recorded not long after the latter's death, there is no record of their having argued that the Earth was flat, and none before Irving is known to have accused them of doing so. Modern historians have dismissed the claim that they did so as a fabrication of Irving's.

The only denial published at the time came from Zacharia Lilio, a canon of the Basilica of St. John Lateran in Rome in 1496. In a section entitled "That the earth is not round" he argues that "when they assert that the earth is round, Ptolemy and Pliny do not add to the evidence, collected on the spot, they simply make a conjecture based solely on reasoning". It is notable that Copernicus, writing only twenty years after Columbus in 1514, dismisses the idea of a flat Earth in two sentences and has to go back to the early Greeks to find a supporter, though he expends more effort on showing that other current ideas were fallacious and demonstrating the sphericity of the earth. In reality, the issue in the 1490s was not the shape but the size of the Earth, as well as the position of the east coast of Asia.

Modern flat-Earthers

In the modern era, belief in a flat Earth has been expressed by isolated individuals and groups, but no scientists of note.

English writer Samuel Rowbotham (1816–1885), writing under the pseudonym "Parallax," produced a pamphlet called Zetetic Astronomy in 1849 arguing for a flat Earth and published results of many experiments that tested the curvatures of water over a long drainage ditch, followed by another called The inconsistency of Modern Astronomy and its Opposition to the Scripture. One of his supporters, John Hampden, lost a bet to Alfred Russell Wallace in the famous Bedford Level Experiment, which attempted to prove it. Rowbotham also produced studies that purported to show the effects of ships disappearing below the horizon could be explained by the laws of perspective in relation to the human eye.

In 1883 he founded Zetetic Societies in England and New York, to which he shipped a thousand copies of Zetetic Astronomy. Challenges were issued in the New York Daily Graphic offering $10,000 to charity to anyone proving the Earth revolved on an axis.

William Carpenter, a printer originally from Greenwich, England, was a supporter of Rowbotham and published Theoretical Astronomy Examined and Exposed - Proving the Earth not a Globe in eight parts from 1864 under the name Common Sense. He later emigrated to Baltimore where he published A hundred proofs the Earth is not a Globe in 1885. He argues that:

• "There are rivers that flow for hundreds of miles towards the level of the sea without falling more than a few feet — notably, the Nile, which, in a thousand miles, falls but a foot. A level expanse of this extent is quite incompatible with the idea of the Earth's convexity. It is, therefore, a reasonable proof that Earth is not a globe."
• "If the Earth were a globe, a small model globe would be the very best - because the truest - thing for the navigator to take to sea with him. But such a thing as that is not known: with such a toy as a guide, the mariner would wreck his ship, of a certainty!, This is a proof that Earth is not a globe."

John Jasper, the black ex-slave preacher said to have preached to more people than any Southern clergyman of his generation, echoed his friend Carpenter's sentiments in his most famous sermon "Der Sun do move and the Earth Am Square", preached over 250 times always by invitation.

In Brockport, N.Y, in 1887, M.C. Flanders argued the case of a flat Earth for three nights against two scientific gentlemen defending sphericity. Five townsmen chosen as judges voted unanimously for a flat Earth at the end. The case was reported in the Brockport Democrat.

'Professor' Joseph W. Holden of Maine, a former justice of the peace, gave numerous lectures in New England and lectured on flat Earth theory at the Columbian Exposition in Chicago. His fame stretched to North Carolina where the Statesville Semi-weekly Landmark recorded at his death in 1900: 'We hold to the doctrine that the earth is flat ourselves and we regret exceedingly to learn that one of our members is dead'.

After Rowbotham's death, Lady Elizabeth Blount created the Universal Zetetic Society in 1893 in England and created a journal called Earth not a Globe Review, which sold for twopence, as well as one called Earth which only lasted from 1901 to 1904. She held that the Bible was the unquestionable authority on the natural world and argued that one could not be a Christian and believe the Earth to be a globe. Well-known members included E. W. Bullinger of the Trinitarian Bible Society, Edward Haughton, senior moderator in natural science in Trinity College, Dublin and an archbishop. She repeated Rowbotham's experiments, generating some interesting counter-experiments, but interest declined after the First World War. The movement gave rise to several books which argued for a flat, stationary earth (e.g.).

In 1898, during his solo circumnavigation of the world, Joshua Slocum encountered a group of flat-Earthers in Durban. Three Boers, one of them a clergyman, presented Slocum with a pamphlet in which they set out to prove that the world was flat. Paul Kruger, President of the Transvaal Republic, advanced the same view: "You don't mean round the world, it is impossible! You mean in the world. Impossible!"

Wilbur Glenn Voliva, who in 1906 took over the Christian Catholic Church, a Pentecostal sect that established a utopian community at Zion, Illinois, preached flat Earth doctrine from 1915 onwards and used a photograph of a twelve mile stretch of the shoreline at Lake Winnebago, Wisconsin taken three feet above the waterline to prove his point. When the airship Italia disappeared on an expedition to the North Pole in 1928 he warned the world's press that it had sailed over the edge of the world. He offered a $5,000 award for proving the Earth is not flat, under his own conditions. Teaching a globular Earth was banned in the Zion schools and the message was transmitted on his WCBD radio station.

Modern biblical literalists have swung to the other extreme over flat Earth theories. For example, the Biblical Astronomer website, while supporting a geocentric model of the Earth, is clear on this, although its description of the foundations shows ingenuity: "In summary, the Bible teaches that the earth is basically a sphere in shape; that there are pillars which undergird the world and which we conclude to be the crystalline rock corresponding to what we commonly call the mantle."

Mohammed Yusuf, creator of the Boko Haram Islamic sect in Nigeria, stated his belief in a flat Earth.

Flat Earth Society

Main article: Flat Earth Society

This flat Earth model depicts Antarctica as an ice wall surrounding a disk shaped Earth

In 1956, Samuel Shenton set up the International Flat Earth Research Society, better known as the Flat Earth Society, as a direct descendant of the Universal Zetetic Society, just before the Soviet Union launched the first artificial satellite, Sputnik. He responded to this event "Would sailing round the Isle of Wight prove that it were spherical? It is just the same for those satellites." His primary aim was to reach children before they were convinced about a spherical Earth. Despite plenty of publicity, the space race eroded Shenton's support in Britain until 1967 when he started to become famous due to the Apollo program. His postbag was full but his health suffered as his operation remained essentially a one-man show until he died in 1971.

Final Frontier Voyager or Flat Earth Society, by George Grie.

Shenton's role was taken over by one of his correspondents, Charles K. Johnson, as he retired in 1972 to the Mojave Desert, California. He incorporated the IFERS and steadily built up the membership to about 3,000. He spent years examining the studies of flat and round Earth theories and proposed evidence of a conspiracy against flat-Earth: "The idea of a spinning globe is only a conspiracy of error that Moses, Columbus, and FDR all fought…" His article was published in the magazine Science Digest, 1980. It goes on to state,

• "If it is a sphere, the surface of a large body of water must be curved. The Johnsons have checked the surfaces of Lake Tahoe and the Salton Sea without detecting any curvature."

The Society declined in the 1990s following a fire at its headquarters in California and the death of Charles K. Johnson in 2001. It was revived as a website in 2004.

Cultural references

The notion of a flat Earth continues to be referred to in a wide range of contexts. Indirect references to the theory include the widely used idiom "the four corners of the earth". The term "flat-Earther" is often used in a derogatory sense to mean anyone who holds views so antiquated as to be ridiculous.

An early mention in literature was Ludvig Holberg's comedy Erasmus Montanus (1723). Erasmus Montanus meets considerable opposition when he claims the Earth is round, since all the peasants hold it to be flat. He is not allowed to marry his fiancée until he cries "The earth is flat as a pancake". In Rudyard Kipling's The Village that Voted the Earth was Flat, the protagonists spread the rumor that a Parish Council meeting had voted in favor of a flat Earth. The 1980 film The Gods Must Be Crazy concerns a Bushman of the Kalahari who decides to travel to "the edge of the world" to dispose of a Coca-Cola bottle that he thinks has evil powers.

Fantasy fiction is particularly rich in references to flat worlds. In C. S. Lewis' The Voyage of the Dawn Treader the fictional world of Narnia is "round like a table" (i.e. flat), not "round like a ball", and the characters sail toward the edge of this world (although, in Lewis' subsequent Narnian novel The Silver Chair, the Earth itself is accepted and written as being spherical, with Narnian king Caspian X being amazed by this fact). Terry Pratchett's Discworld novels (1983 onwards) are set on a flat, disc-shaped world that rests on the backs of four huge elephants that stand on the back of an enormous turtle. Many explorers died falling off the edge trying to prove that it's not so.

Scientific satire

In a satirical piece published 1996, Albert A. Bartlett, an emeritus Professor of Physics at the University of Colorado at Boulder, uses arithmetics to show that sustainable growth on Earth is impossible in a spherical Earth since its resources are necessarily finite. He explains that only a model of a flat Earth, stretching infinitely in the two horizontal dimensions and also in the vertical downward direction, would be able to accommodate the needs of a permanently growing population and economy.

The purpose of this piece is to demonstrate the impossibility of permanent growth rather than to advocate the idea of a flat Earth, given that it does not present any evidence for a flat infinite Earth but rather lists a number of reasons which make this very unlikely, making the satirical character of this essay clear:

If the “we can grow forever” people are right, then they will expect us, as scientists, to modify our science in ways that will permit perpetual growth. We will be called on to abandon the “spherical earth” concept and figure out the science of the flat earth. We can see some of the problems we will have to solve. We will be called on to explain the balance of forces that make it possible for astronauts to circle endlessly in orbit above a flat earth, and to explain why astronauts appear to be weightless. We will have to figure out why we have time zones; where do the sun, moon and stars go when they set in the west of an infinite flat earth, and during the night, how do they get back to their starting point in the east. We will have to figure out the nature of the gravitational lensing that makes an infinite flat earth appear from space to be a small circular flat disk. These and a host of other problems will face us as the “infinite earth” people gain more and more acceptance, power and authority. We need to identify these people as members of "The New Flat Earth Society" because a flat earth is the only earth that has the potential to allow the human population to grow forever.”

The satiric nature of the piece is also made clear by a comparison to Bartlett's other publications, which mainly advocate the necessity of curbing population growth.

See also

• Bedford Level experiment
• Denialism
• Earth's rotation
• Geographical distance
• Hollow earth
• Scientific mythology
• Skepticism
• Spherical Earth

Further reading

• Fraser, Raymond (2007). When The Earth Was Flat: Remembering Leonard Cohen, Alden Nowlan, the Flat Earth Society, the King James monarchy hoax, the Montreal Story Tellers and other curious matters. Black Moss Press, ISBN 978-0-88753-439-3
• Garwood, Christine (2007) Flat Earth: The History of an Infamous Idea, Pan Books, ISBN 1-4050-4702-X
• Simek, Rudolf (trans.Angela Hall) "Heaven and Earth in the Middle Ages"[10]

External links

• The Myth of the Flat Earth
• The Myth of the Flat Universe
• You say the earth is round? Prove it (from The Straight Dope)
• Flat Earth Fallacy
• Zetetic Astronomy, or Earth Not a Globe by Parallax (Samuel Birley Rowbotham (1816-1884)) at sacred-texts.com
• The flat-earth myth and creationism