SURVEYING THE EARTH

 

 

BEYOND THE FAIRYTALE LAND of heroes and villains and momentous conflicts between truth and falsehood on an individual, cultural and conceptual scale, flat-earth belief can be traced back to some of the most ancient civilizations in world history. The first of these are the Sumerians and Babylonians, who inhabited Mesopotamia, the land between the Tigris and the Euphrates (the site of modern Iraq) from c. 4500 to 500 BC. Although these peoples left texts describing a range of cosmological theories - too many to speak of a single, overarching Mesopotamian world-view - they developed the idea of a tripartite universe, with the earth as a flatsurface ruled by the god Enlil, sandwiched between the sky and the underworld. For the Egyptians, the same triple-decker arrangement applied, with the sky resting on four pillars, forked poles or mountain peaks rising from the corners of the flat earth beneath. While the Egyptian system differed in detail from the Sumero-Babylonian world-view, it too personified natural phenomena, representing the earth as the earth-god, Geb, lying outstretched to create the plane. The sky, meanwhile, was the goddess Nut, mother of the sun-god Re, who was depicted as a giant standing cow or a young woman arched over the earth like a canopy. And so the situation remained; while later Egyptians made voyages to the so-called land of Punt, thought to be along the coast of East Africa, and other evidence suggests that they circumnavigated the continent, such experiences had no impact on ideas about the shape of the earth. This being the case, in the eyes of the oldest civilizations for which we have records, whether in the form of Babylonian clay tablets or Egyptian papyri, the earth continued to be a flat surface of a circular or rectangular shape.1

It remained the same for the ancient Hebrews, who were flanked by the Egyptians to the south-west and the Sumero-Babylonians to the north-east, and whose cosmology resembled the assumptions of their powerful neighbours about the form of the earth. In terms of cosmology and creation, the Old Testament owes much to Mesopotamian mythology, which has led to claims that the Bible is a 'flat-earth book'.2 Although the scriptures do contain disparate passages relating to cosmology they are not a systematic study of the heavens, however, rendering any presentation of a Biblical world-view a patchwork of statements scattered through books written over several centuries. Nevertheless, it had been claimed that the Bible presents a reasonably clear and consistent view of a tiered universe based on the Sumero-Babylonian model. In this system, the cosmos consists of the vault of heaven (shamayim), or 'firmament', containing the sun, moon and stars (Genesis 1:14-17). The Bible teaches that these heavenly bodies move across the stationary earth (Psalms 19:1-7), while the firmamentrests on pillars or mountains (Job 26:11) rooted in the flat earth below. Beneath the earth lies the underworld, Sheol, seen as the abode of the dead (Numbers 16:28-34; I Samuel 28:13-15; Isaiah 14:9-11; Ecclesiastes 9:10). The earth, which is generally depicted as an immovable disc or 'circle' (Job 26:10), supported on water (Psalms 24:2) or in empty space (Job 26:7), is bordered by a protective barrier, probably a mountain range. As for its shape, it is generally spoken of as a flat disc, so that if one travelled far enough one would eventually arrive at the 'ends of the earth' (Deuteronomy 13:8, 28:64; Isaiah 5:26; Psalms 135:7). Within this scheme, the four corners of the earth (Isaiah 11:12, Ezekiel 7:2) might refer to distant regions, unless taken literally, when the earth could be considered rectangular or square.3

Flat-earth belief was also prevalent in Ancient Greece, details of which are provided in the writings of Aristotle (384-22 BC), who had a habit of reviewing his predecessors' opinions as a precursor to demolishing them with his own. His cosmological treatise On the Heavens (350 BC) provides a useful, if polemical, survey of opinions dating from Thales, the Ionian geometer, astronomer and engineer (c. 625-c. 547 BC), in the sixth century BC.4 The first speculative thinker of the Ionian school, he believed the earth was a circular disc floating like a piece of wood on the world (meaning universe) ocean, while his pupil or younger associate, Anaximander (c. 611-c. 545 BC), argued that the earth was a cylindrical column floating upright in air in the centre of the universe. According to Aristotle, Anaximander believed that this column was three times as broad as it was high with humankind inhabiting the flat uppermost surface.5

Meanwhile, the third philosopher of the Ionian school, Anaximenes (c. 585-525 BC), is reputed to have believed that the heavenly bodies were flat, and likely thought the same of the earth, although the precise details of his view remain unknown. Indeed, when dealing with pre-Socratic thinkers - each of whom seemed to design his own cosmological system but left no writings - we are reliant on fragments for clues about a number of complexviews. Yet in terms of who knew what, when and how, the Ionian school has been credited with being the first to practise a broadly philosophical and naturalistic way of looking at the world; that is to say, they began to ask a new range of questions about nature in terms of its phenomena, its composition and the way that it worked. Thales and Anaximander began to think of the world as an orderly, unitary whole that was worth investigating for its own sake, beyond its role as the realm of gods, and they looked further than Zeus and his cohorts for explanations about the way things worked. Here, then, are traces of the beginnings of what we now know as 'science' and 'philosophy', although religion and astrology continued to play a central role in and around new lines of enquiry, meaning that shifts were exceedingly gradual and sporadic. The same may be said of the development of ideas concerning the shape of the earth.6

It was not until the late sixth century BC that the flat-earth thinking that had dominated world-views for several millennia was to take a more radical turn through the teachings of the Pythagoreans. A much-mythologized philosophical school, it was based at the other extremity of the Greek world from the Ionians, in the thriving city of Croton in what is now southern Italy. Its leader, Pythagoras (582-500 BC), the most famous mathematician in Ancient Greece, was the son of a silversmith and gem engraver and later a pupil of Thales and Anaximander at Miletus. Having travelled in Babylonia and Egypt, at some time around 530 BC, Pythagoras settled at Croton where he established the Pythagorean brotherhood, a large, close-knit religious community that held extensive political power in its hometown and the surrounding area, Magna Graecia (Greek-governed southern Italy). While Pythagoras appears to have been a visionary who, according to Athenian philosopher Plato (c. 427-c. 347 BC), taught a whole way of life, in the absence of writings it is impossible to extricate his ideas from those of his followers in a school of thought that was bound by confidentiality and which undoubtedly developed its doctrines over something in the region of two centuries. Amongan abundance of ideas that have been ascribed to the Pythagoreans or Pythagoras himself are a focus on purification and the practice of silence, the belief in a mystical union with all living things and the immortality and transmigration of the soul, along with a veto on various activities, including leaving a cooking pot's imprint visible in the ashes of a fire and standing on one's own toenail clippings. Best known, however, is Pythagoras's teaching that number lies at the heart of all things; it is the realm of eternal perfection and absolutes of which all things are composed. The contemplation of geometrical forms and patterns was believed to allow the mind to surpass the earthly appearance of reality and engender a connection to the divine, although again there is no certainty about exactly what Pythagorean number-related teaching involved.7 As a whole, Pythagorean philosophy seemed to be based on a vision of mystical unity in nature, with number at the root of all things, from the theorem governing right-angled triangles (the square of the hypotenuse is equal to the sum of the squares of the two other sides) to those governing rhythm and acoustics in music- the connection between the pitch of a note, for example, and the length of a string.

In a religious world-view based on numbers and measurement, shapes and sizes, patterns and unity, heavenly movements and the shape of the earth were obvious sources of interest as natural manifestations of the divine. It has been suggested that Pythagoras learned the basics of his astronomy and mathematics from his travels in 'the East', but whatever the case, when it comes to ideas about the shape of the earth, a feature at the heart of traditional histories of science is entirely bypassed. While Pythagoras, or the Pythagoreans, are generally credited with being the first to argue that the earth is a globe (although doubtless someone suggested the idea before), it is ironic that the name of the first individual 'discoverer' of one of the most basic scientific facts is a mystery. All that can be said is that the Pythagoreans believed that the earth was a globe floating freely in space because the sphere was the perfect shape. In addition, it is impossible to say how readily thisdoctrine was accepted outside their school, in educated circles or through society as a whole. Importantly, post-Pythagorean philosophers, most notably Anaxagoras of Clazomenae (497-428 BC) and the atomists Leucippus of Miletus (fl. 440) and Democritus of Abdera (c. 460 BC-c. 370 BC), were still arguing that the earth was disc- or drum-shaped in the fifth century BC.8 That said, Pythagorean speculations brought into play the idea of a spherical earth and were to have a profound influence on Plato. By the time his pupil Aristotle was writing, later in the fourth century BC, the globe concept seems to have become widely accepted among educated people.

In this way, the three-tiered earth, heaven and underworld system of Near Eastern cultures gradually faded from view, replaced by visions of a spherical earth and an all-encompassing sky. Undoubtedly, changing perceptions were bolstered by practical, cultural and environmental factors, particularly that the Ancient Greek world was surrounded by sea. It has been suggested that the culture's consequent geographical knowledge and maritime experience may have triggered the switch from the world-view prevalent in the literal and metaphorical flatlands of Babylonia and Egypt.9 Certainly Aristotle invoked the proof of ships disappearing over the horizon, hull before masts, along with the earth's circular shadow on the moon during a lunar eclipse and the different appearance of stars when viewed from different latitudes, to support the contention that the earth was a globe in his book On the Heavens. The mainstream consensus, all of the renowned Greek writers, from Plato to Eudoxus (c. 375 BC), Euclid (c. 300 BC), Aristarchus (c. 310-230 BC) and Archimedes (287-212 BC), accepted a globular earth, while Aristotle's geocentric cosmology - centring on an immobile sphere at the centre of the universe with the planets moving around it in perfect concentric circles - was to dominate Western cosmological thinking until the work of Copernicus and Galileo nineteen centuries later.10

With consensus reached on the shape of the earth, focus shifted to estimating its size. By the fourth century BC, Aristotle reports,efforts had already been made to calculate the circumference - perhaps by the different positions of the stars when viewed from different latitudes - which had resulted in the oldest existing estimate at 400,000 stadia. If a stade is taken to be c. 500 feet (a moot point because measurements were not standardized), this would give a figure of 39,000 or 40,000 miles at the equator.11 Further estimates followed and by the third century BC we have details of an experiment to measure the globe's diameter. The test was undertaken by the Greek polymath, Eratosthenes (c. 276-c . 194 BC), director of the famous library in the museum of Alexandria, then the Egyptian capital and centre of Hellenistic culture and learning. Essentially, he is said to have noticed that at noon on the summer solstice the sun was directly overhead at Syene (present-day Aswan) because a vertical pointer cast no shadow and the sun's rays shone to the bottom of a deep well. At the same time in Alexandria, which Eratosthenes believed to be 5000 stadia (approximately 530 miles) due north, the sun made an angle equivalent to one-fiftieth of a circle or 7.2 degrees to the vertical. Assuming that the sun's rays are basically parallel, Eratosthenes then used geometry to calculate the earth's circumference to 250,000 stadia, possibly somewhere in the region of 29,000 miles.12 Although there were flaws in Eratosthenes's data, and the exact length of a stade, or stadium, is unknown, his estimate for the earth's circumference is not far from the present-day value of approximately 24,860 miles.

Mathematicians continued to estimate the size of the earth, while they also focused on cracking a puzzle on a much larger scale: explaining their geocentric vision of the universe, or how the planets moved around the central, immovable and, of course, spherical earth. In the second century, the theories and findings of six centuries of astronomical research were finally drawn together by the Greek geographer, mathematician and astronomer Claudius Ptolemy (c. 130-75), in his encyclopedic compilation of ancient knowledge Syntaxis, commonly known by its Arabic name Almagest or 'the greatest'. Compiled from the archives of the library atAlexandria, where Eratosthenes had earlier been based, the book's name was fitting indeed, for the theories of Almagest remained the mainstream for Arabic and Latin civilizations until set aside in favour of the heliocentric, or sun-centred, solar system proposed by Copernicus in the mid-sixteenth century. The Ptolemaic system was essentially a more complex version of the Aristotelian system, with adjustments to account for variations in the observed distances of the planets from the earth. By late antiquity, the Aristotelian-Ptolemaic system of circles and spheres, cycles and epicycles, dominated perceptions of the heavens, with a static spherical earth placed in the centre. Moreover, in common with Aristotle, Ptolemy's Almagest provided a number of 'sensible' (sense-related) proofs for why the earth must be this shape.13

With the earth established as spherical for a number of centuries, the question becomes the survival and dissemination of the idea. Although factors surrounding the gradual disintegration of the Roman Empire (180-450) caused many works of classical antiquity to be lost to the Latin-speaking West, including Aristotle's On the Heavens and Ptolemy's Almagest, a few significant texts were translated into Latin from the original Greek. Such works included a partial fourth-century translation of Plato's cosmological treatise Timaeus, which, albeit primitive by later Greek standards, reflected a globular view of the earth. The book was to serve as a principal cosmological authority alongside the work of popular Roman writers Pliny the Elder (c. 79), Macrobius (c. 400), Martianus Capella (c. 420) and Boethius (c. 480-524), all of whom helped the Ptolemaic view of a spherical earth to survive in the Christian West without any input from the Islamic world.

Although the earth and its shape or size were not focal points for education or research, Christianity had a critical role in preserving and spreading the scientific knowledge that had survived from Greco-Roman times. Of particular importance was the study of the quadrivium, the study of four liberal arts - arithmetic, geometry, astronomy and music (often accompanied by medicine) - which took place in monastic and cathedral schools between thefifth and twelfth centuries and further disseminated knowledge of the spherical shape of the earth.14

Although Christian flat-earthism was a favourite theme of 'Dark Age' promoters and warfare polemicists Draper and White, early Church fathers were not Biblical literalists who believed that the Bible was the only authority on the natural world or that the earth was a plane. The majority accepted that it was a globe, took the scriptures allegorically or simply sidestepped the issue and any associated controversy. However, there are always extremists in any field, and Lactantius and Cosmas Indicopleustes were joined in the promotion of Bible-based flat-earth belief by an atypical few, most notably Severianus, Bishop of Gabala (c. 409), and his contemporary, one-time Bishop of Constantinople, St John Chrysostom (344-408). Some detractors founded their argument on scriptural passages such as those referring to the four corners of the earth, while others were also keen to denigrate pagan (pre-Christian) culture, including the teaching that the earth was a globe. Among a number of radical flat-earth arguments, the most common was the 'fable of the Antipodes' - that there could not be an undiscovered side of the earth where crops and trees grew upside-down and people walked with their feet above their heads. The term 'Antipodes' (podes being Greek for 'feet ' ) was coined by Pythagoras and means 'feet pointed in a direction that was opposite' or 'people with their feet turned towards ours'. For flat-earth advocates, the idea of the Antipodes was absurd so they reasoned that the earth must be flat.

The problem for the majority of theologians, meanwhile, was not the existence of the Antipodes, or the associated fact that the earth was a globe, but rather the idea that people could live on the other side of the sphere. This concept of an inhabited Antipodes was opposed on a variety of grounds: it conflicted with Christian belief in the unity of the human race, descended from Adam and Eve, and the consequent universality of original sin and redemption to be resolved on Judgement Day. If there was another race living in the Antipodes, how had they got there, how could they havereceived the Word of God (if the Apostles were instructed to preach the Gospel to all nations) and why did the Bible not mention them? These questions were bolstered by a more practical point. Even ancient mariners had experienced an increase in temperature as they neared the equator and the fact that no one had ever voyaged into the southern hemisphere was translated into the idea that the equator was too hot to cross and the other side of the earth too sultry to be inhabited. (It was these assumptions, along with those about the distance involved, that underpinned questions about Columbus's voyage, rather than concerns that he would sail off the edge of the earth. At a time when no one was certain just what proportion of the world was land and what was sea, the revolutionary aspect of Columbus's endeavour lay in putting theoretical knowledge to a practical test.)15

Arguments about whether people lived in the Antipodes had no impact on mainstream acceptance of a spherical earth, and all of the most widely renowned and distributed authors of the early medieval period were in firm agreement on the point. They included St Augustine (354-430), Bishop of Hippo in Romancontrolled North Africa (now Annaba, Algeria), who confirmed his belief in a spherical earth in a number of his writings. However, like many early Christian writers, St Augustine was far more concerned with the spiritual than the natural world, and with the Church and eternal salvation at stake, questions such as the shape of the earth faded into comparative insignificance. His emphasis on an allegorical rather than literal reading of the scriptures naturally extended to the shape of the earth, and he argued that depictions of a flat earth with the sky spread over it like a tent were simply metaphors or figures of speech.16 But where he argued most vociferously was on the Antipodes issue for, like the majority, St Augustine was convinced that people could not live on the other side of the globe because the Bible 'speaks of no such descendants of Adam', does not mention any preaching of the gospel in that region and Antipodeans would not be able to see Christ come down to earth when he returned on Judgement Day. While StAugustine believed the earth was a globe, he followed many of his contemporaries in asserting that men were confined to the oikoumene, the inhabited portion of the earth, and it was impossible for anyone to cross the immense expanse of ocean that surrounded this, the known world.

In the sixth and seventh centuries, St Augustine's stance on the shape of the earth was supported, albeit vaguely, by the most popular encyclopedist of the era, St Isidore of Seville (died in 636), and more directly by the so-called father of English history, the Venerable Bede (673-735). Along with St Ambrose's and St Jerome's, their work was standard educational fare in monastic and cathedral schools and libraries, and so, too, was the lesson that the earth was a globe. As monks or those taught in monasteries constituted much of the educated class in early medieval Europe, the spherical consensus of the Greeks - represented by Plato, reflected by Pliny, St Augustine, Bede and others and disseminated through theological channels - survived, despite the objections of an extreme few.

From the twelfth century onwards, the situation became clearer still, when Latin translations of works from Greek antiquity, along with Arabic and Jewish scholarship, gradually became available in the West. The intellectual impact of such waves of translation is inestimable. Complete versions of Ptolemy's Almagest, Aristotle's Physics, Metaphysics, Meteorology, On the Heavens and more opened up a whole new vista of ideas, methodologies and technical know-how, ready for integration into the curricula of the new universities that were being established around Europe. In this context, astronomia (astronomy) was a branch of philosophy, rather than an area for study in its own right, but with geometry and geography it was a compulsory subject taught as part of the standard university curriculum focusing on the seven liberal arts.17 In educated circles, Ptolemy's Almagest and Aristotle's On the Heavens, complete with discussion and proofs of a spherical earth, gradually displaced Plato's Timaeus as the key cosmological treatises of the age. With important exceptions (not least about the creation), aspects of Aristotle's work was accepted by medieval theologians as thestandard guide to the natural world.18 Writ large, the relationship of natural philosophy and religion was one of complex interaction, assimilation, reconciliation and interchange, rather than outright suppression or unmitigated dispute.19

From the twelfth century onwards, the flat-earth concept is almost a non-issue, so prevalent are written and visual images of a spherical earth. From the most popular astronomical text of the Middle Ages, John of Sacrobosco's On the Sphere (De sphaera, c. 1250), to the work of scholastic philosophers such as Thomas Aquinas (1225-74) and Jean Buridan (1300-58), not to mention Dante's Divine Comedy and the royal 'earth' orb held by medieval kings, culture was suffused with images of terra rotunda to such an extent that serious promulgation of flat-earth belief would become little more than a waste of time. The only remaining cause for confusion is medieval mappae mundi, or maps of the world. Until the fifteenth century the most common variety of world map was the 'T and O' type, which seems to depict the earth as a flat disc consisting of a central T-shaped landmass with Asia at the top of the T, Europe in the bottom left area and Africa to the right, surrounded by an O-shaped ring of sea. To twenty-first-century eyes, these maps present strange and frequently beautiful images, decorated with mythical beings and sea-monsters in hand-painted colour embossed with gold, yet they were not intended as literal representations of the world. Unlike modern-day maps, with a more functional purpose, medieval mappae mundi were symbolic depictions of the known inhabited portion of the sphere, the T-shaped oikoumene, which was confined to the northern hemisphere because, although, like St Augustine, they were aware that the earth was a globe, monastic map-makers believed the Antipodes were uninhabitable and not worth including on their maps. With a focus set on conveying moral meaning to the illiterate masses, medieval cartographers represented the earth in its religious, political and spiritual aspects rather than in strictly geographical terms. Consequently, their maps featured images of Christ and kings, towers and turrets, Adam and Eve and the Garden of Eden, withJerusalem placed at the centre of the world to highlight its place as the metaphysical rather than literal heart of the world.20

With flat-earth belief firmly consigned to the ancient past, from the mid-sixteenth century, debate became concentrated on the supposed position and motions of the terrestrial sphere. Central to this development was the work of Polish astronomer Nicolaus Copernicus, who published On the Revolution of the Celestial Orbs in 1543. Shockingly, the book challenged the Aristotelian-Ptolemaic vision of a geocentric (earth-centred) universe, an idea that had dominated astronomy for approximately 1800 years. As an alternative, Copernicus posited a heliocentric (sun-centred) system, whereby the earth became just another planet in orbit round the sun, rather than the fixed centre of the universe as the subject of God's special creation. In 1616, mindful of the potential impact on Biblical interpretation, the Catholic Church banned books that argued in favour of the motion of the earth. Nevertheless, the Copernican thesis was explored and expanded by German mathematician Johannes Kepler, who discovered that the planets do not trace a circular course round the sun, as Copernicus had thought, but instead move in ellipses. Meanwhile, in Italy, Galileo Galilei was using a telescope to make a number of discoveries that contradicted the Aristotelian system with empirical proof of a Copernican sun-centred universe.

Most widely lauded in later popular imagination, however, was Cambridge-based mathematician Sir Isaac Newton, whose classic works, the Principia (1687) and Opticks (1709), underpinned the marriage of mathematics with astronomy. Fundamentally, Newton presented the world with a rational, well-regulated cosmological system; from the analysis of observed facts he seemed to impose order and regularity with general principles such as the three laws of motion and the principle of universal gravity. On the earth itself, Book III of the Principia provided theoretical proof that it is not a perfect sphere but an oblate spheroid that bulges at the equator due to its rotation, a result confirmed by French expeditions during the eighteenth century. Yet Newton's findingswere applied far beyond geodesy and astronomy, exceeding even the realms of natural philosophy. Throughout the eighteenth century aspects of his work were adopted as key features of Enlightenment thinking: French philosophes like Voltaire were gripped by the possibilities it seemed to promise. Nature appeared to be reasonable, operating by laws that were waiting to be uncovered by the rational observer. Inspired by the idea, thinkers assumed that man, as part of nature, must be the product of similar principles. The ramifications of this were staggering, some philosophes supposed, for if overarching laws could be discovered in the external world around us, then why not in human beings and society as a whole? Spurred on by their interpretation of Newton's work, their attempt to find fundamental laws was translated from mathematics and astronomy to ethics and morality, while the path to such discovery was believed to be reason.

Henceforward, the philosophes proclaimed that the study of human society should be characterized by scientific methods; it was believed that careful observation and the collection of empirical data, rather than the contemplation of abstract principles, could uncover the laws governing human existence.

Armed with this new-found confidence to discover causality, radical thinkers promoted the idea that humankind was no longer at the mercy of strange forces beyond its comprehension. In some philosophical circles, scepticism was paramount and French Enlightenment thinkers, keen to identify themselves as modern and revolutionary, attempted to banish irrational beliefs of the supposed 'Dark Ages' to the shadows.21 In this there was a great irony: Newton - Protestant, Bible scholar, astrologer and alchemist - viewed science, philosophy and theology as inseparable components of one great whole. While many chose to promote a materialist 'Newtonian' image of a mechanical, clockwork universe (in itself first promoted by French philosopher, René Descartes), Newton had not removed God from the equation: he believed that the Deity intervened in his creation from time to time.22 In fact, the approach common to Newton and his contemporaries wasmuch different from what we now understand as science; 'Natural Philosophy' was a diverse corpus of ideas and practices that would seem arcane, alien and peculiar to scientists practising today.23 But Newton's personal religious views or the realities of natural philosophy were beside the point for philosophes with a radical, secular goal in mind. In their efforts to popularize Newton's achievement, Voltaire and his disciples glossed over the religious, astrological and alchemical aspects of his work in keeping with their programme of sweeping social reform.

Through the eighteenth and early-nineteenth centuries, authors, savants and travelling lecturers shouldered the task of disseminating accessible versions of Newton's work to educated audiences in England and abroad. It was a weighty undertaking: among many rival cosmologies, Newton's achievements were immense and few possessed the technical knowledge to fathom fully their profundity and magnitude. It has been estimated that around the time the Principia (1687) was published, it was read from cover to cover by less than a hundred contemporaries and fully understood by just a fraction of those.24 Speakers confronted this issue by boiling down Newton's work into more easily digestible versions,25 while the coffee-houses and academies of Europe provided platforms for the explanation and popularization of these Newtonianism(s). In the eighteenth-century heyday of the popular astronomy lecture, lay audiences were entranced by what the speakers revealed. The exploitation of visual aids - models, orreries, simple demonstrations and illuminated lantern slides - could render such occasions both exciting and sublime, while expositions, dictionaries, handbooks and fictionalized accounts became important channels for the dissemination of key ideas.26

Just as Newton's work was reconstituted and sold to the public so, too, were his manuscripts, his scientific instruments and even locks of his hair, fuelling a phenomenon that raised him to the status of secular sainthood. While this thirst for objects - for a piece of Newton - fed burgeoning trends of commemoration and reverence, his image, literal and figurative, was being carved bycraftsmen and savants across England and beyond. As sculptures, engravings and death masks were bought and sold, haggled and competed over by collectors and memorabilia hunters on the Continent, authors and lecturers presented Newton as the epitome of the high-principled scientific genius who had provided a faultless demonstration of how the scientific method of observation and experiment could uncover the truth about the external world.27 As with Darwinism centuries later, Newtonian astronomy was customized, re-presented and co-opted to support a diverse range of interests. Criticisms were advanced and the dissemination of its ideas was patchy, but the principles and practices it embodied grew to have a massive impact, lasting through the eighteenth century and beyond.

By the 1830s, ideas about the earth and its creation were also shifting rapidly, and the apparent divergence between a literal interpretation of Genesis and scientific findings, especially from the groundbreaking new field of geology, was the subject of extensive discussion and controversy. While medieval theologians had not interpreted Genesis word for word, seventeenth-century churchmen and scholars had begun to promote a literal reading of the Bible. When understood in this way, Genesis seemed to describe the creation as a series of sudden, miraculous, Godinspired events that could have occurred as recently as 4004 BC, according to one well-known estimate. According to the Bible, this episode had supposedly established a fixed and unchanging natural order, a great chain of being from God to man to the lowest life forms. By the nineteenth century, however, this system was being brought into question by the flourishing young science of geology. Within this field, new techniques enabled the surveying and mapping of strata and their fossilized contents in chronological order, an innovation connected with amateur geologist William Smith, the first to work out the correct succession of strata in England and Wales. While establishing boundaries between various stratigraphical systems (Silurian, Devonian and so on) subsequently caused much dispute, debate was also simmering about theage of the earth. In his book Theory of the Earth (1795), Scottish geologist James Hutton had argued that it was created by a never-ending cycle of slow changes over an extensive period of time. One of many competing theories at the time, the majority favoured an alternative model - catastrophism - which held that the earth and the whole work of creation were produced by violent, sudden change. This theory was challenged in the 1830s, when Hutton's 'steady state' model of the earth's history, known as uniformitarianism, was fully articulated by barrister-turned-geologist Sir Charles Lyell in his controversial three-volume Principles of Geology (1830-33). This book showed how ever-present change operated through agents such as earthquakes and erosion, thus disputing the idea of a relatively recent, sudden creation as described in Genesis. Debates on the issue were heated and ongoing, but the basic tenet of Lyell's theory - that the earth had an extensive history - eventually became the more mainstream view.

Meanwhile, further reassessment of the Genesis story had been prompted by sequential fossil finds that revealed the earth had passed through a number of geological ages, each with its own species of animals and plants. It appeared that creatures such as mammoths and mastodons had once existed, but had become extinct. Such findings, commonly associated with French palaeontologist Georges Cuvier, challenged the Biblical image of a fixed and unchanging great chain of being from God to man to the lowest life forms, although Cuvier advanced the idea of immense geological catastrophes followed with new creations by God to explain new species in the fossil record. More radical, however, were the evolutionary ideas of French naturalist, Jean-Baptiste Lamarck. In Zoological Philosophy (1809), he advanced a theory that the simplest forms of life had originated in matter as the result of a series of physical and chemical reactions - a type of spontaneous generation. This living matter, forced to exert itself to adapt to its environment, had transmuted (evolved), passing on its acquired characteristics to the next generation, producing higher and more complex organisms until the development of man.Lamarck, sidelined in his lifetime and after his death, had a limited impact on his peers and the public, and failed to provide an adequate explanation for what made life-forms grow and develop (a mechanism, natural selection, was later discovered by Charles Darwin and Alfred Russel Wallace). However, the idea of transmutation central to Lamarck's theory introduced the abominable notion that man, supposedly the highest being created in God's own image, had evolved from the most menial life-forms by a natural, non-divine self-motivating mechanism.28 Finally, radical challenges to Genesis were joined by cosmology in the shape of the 'nebular hypothesis'. A theory proposed in the eighteenth century by German philosopher Immanuel Kant, and refined by French physicist Pierre-Simon Laplace, the nebular hypothesis taught that the stars and planets originated from immense, diffused revolving clouds of cosmic gas and dust (nebulae), a process that, when taken at its most extreme, dispensed with the need for creation and a creator altogether.29

Although some ideas, such as transmutation, were so radical they were deemed taboo, most theologians were able to integrate new geological findings into a liberal reading of the Genesis story. At a time when most geologists were Anglicans, it was common for them to explain the great age of the earth by interpreting the six 'days' of creation as long geological ages (day-age theory) or by incorporating a series of catastrophes and new creations into the earth's history to explain the fossil record, as with Cuvier. While eighteenth-century philosophes had promulgated the myth that reason replaced superstition through science, the reality remained one of synthesis rather than substitution. The materialist vision of a mechanistic 'clockwork' universe promoted by Enlightenment thinkers was a concern for the British scientific elite, however, because this was a seemingly random world created by blind natural laws. Such radical attempts to remove God from the equation provoked a revival of 'Natural Theology,' whereby the Anglican clergymen who dominated natural philosophy and monopolized related academic posts sought to collect and present evidence ofGod's design in nature. Their vision, rooted in seventeenth-century ideas, emphasized nature as God's creation; thus, the central purpose of their surveys was to provide plentiful proof of the divine architect's wisdom and skill. In keeping with Christianity's predominance in eighteenth-century society, belief and intellectual life, it was held that the existence and nature of God could be demonstrated by the study of his creation; conversely, the world was so perfect in its design that it was evidence of a benevolent higher power at work. In 1802, the 'argument from design' found its most celebrated expression in clergyman William Paley's Natural Theology; or Evidence of the Existence and Attributes of the Deity, collected from the Appearance of Nature, which famously used the complexity of the human eye as an example of deliberate, intricate invention by God. Within this system it was assumed that each creature had been specifically designed for its place in nature and society; thus natural theology was used as an ideological prop for the existing social order and the political status quo - fine for the parsons in their cosy country parishes, less satisfactory for child workers in mills.30 Whatever the case, the argument from design dominated popular scientific culture; it was an immensely powerful and appealing idea. In the late 1820s, the eccentric Earl of Bridgewater, Francis Henry Egerton, was so inspired by Paley's Natural Theology and the desire to atone for an eventful life, that he bequeathed £8000 to the Royal Society to finance a similar work.31 The subsequent eight-volume survey of the 'divine watchmaker's' handiwork, The Bridgewater Treatises (1833-40), was hefty, expensive and, as a consequence, not widely read yet it indicated the scientific status quo in the 1830s, the continuing influence of the argument from design, the cross-fertilization and interconnection between science and Christianity, and the might of creationist (although not literalist) views.32

So this survey has come full circle. From the myths of modern writers to those of ancient civilizations, from images of medieval flat-earth belief to nineteenth-century creationist views, the history of ideas about the earth is more than a straightforward narrativeabout the establishment of a scientific fact. Yet amid a mass of shifting perceptions - of science, religion and history alongside changing views of the physical world - a globular earth has been the educated consensus since at least the fourth century BC.33 Despite this, the flat-earth idea, last commonly believed by educated people in the far reaches of antiquity, has been transformed into a political tool by modern storywriters hunting for an angle, or by polemicists seeking to argue their case for science against supposed Christian closed-mindedness. It is here that history takes a strange twist indeed, defying expectations about the progress of knowledge from varying points in the human past. For the flatearth idea has undergone a revival through the nineteenth and twentieth centuries - the work of a movement of true believers determined to prove that conventional scientific knowledge is a delusion, the Bible is literally correct and the earth is flat.

Notwithstanding its status as the world's most infamous alternative idea, flat-earth belief is important in several respects. Because believers claim the Bible teaches that the earth is flat, it provides vital insights into the rise of modern creationism, generally traced to the work of Seventh Day Adventist geologist George McCready Price (1870-1963), and The Genesis Flood, a book published by John C. Whitcomb Junior and Henry M. Morris in 1961.34 In fact, in adhering to an exceptionally strict literal interpretation of the Bible, flat-earth believers might be classed as extreme creationists, a salient point in the light of contemporary debates about the teaching of evolution in schools and other ongoing Christian fundamentalist campaigns, such as those opposed to same-sex marriage and abortion. While flat-earth belief is widely ridiculed, it remains a central point of departure between a literal interpretation of the Bible and the findings of science; indeed, flat-earth campaigns provide interesting comparisons with the modern creationist movement in a variety of ways. For this reason the flat-earth idea is a pivotal concept: it is one of the most radical and readily refutable Bible-based truth claims about the natural world, while the rotundity of the earth is one of the most fundamentalscientific facts, a cornerstone of received knowledge. Despite its apparent absurdity, flat-earth belief therefore occupies a unique place in the relationship between science and Christianity. It raises issues central to science education, the uses and abuses of information, the making of knowledge about the natural world and the psychology of human faith, while the extraordinary history of flat-earth campaigns involves a plethora of conspiracies, counter-cultural critiques and subversive discourses ranging from the moon-landing hoax to the end of the world.