New Atheists love astronomer and science educator Neil deGrasse Tyson. It’s not hard to see why, given that Tyson is a pretty lovable guy: he’s charismatic, articulate, poised, funny and does a good job of bringing science to the masses. And this is something he did back in January where a rapper called “B.o.B.” began tweeting that the world is actually flat. Yes, this genius actually believes that the whole spherical world idea, known since the sixth century BC and proven by small things like Magellan’s circumnavigation and thousands of space flights, is actually a big conspiracy. B.o.B also believes that genetically modified crops, the Holocaust, NASA and science generally are all conspiracies as well. Because he’s a moron.
So Tyson did what a good science educator should do and gave B.o.B. and his fans a quick lesson in how we know that the earth is, in fact, not flat. And he was doing well … until he tweeted this:
So according to Neil deGrasse Tyson, people 500 years ago believed the earth was flat. Except, ummm, they didn’t. Luckily there are a few people out there whose grasp of history is rather better than Tyson’s, so a few days later someone questioned the great man’s assertion:
But the great STEM Lord was having none of this and proceeded to use his mighty powers of sciency scienceness to make declarations about history because, science:
Ah – the “Dark Ages”! So the impertinent peon was silenced and everyone got back to being all scientific and rational. Neil deGrasse Tyson had spoken and, being a scientist, what he had said must be right. Because, science.
Except, he was wrong.
Inventing the Flat Earth
Tyson can perhaps be forgiven to a certain extent. The idea that the knowledge of the shape of the earth was “lost to the Dark Ages” and only finally restored by Columbus’ voyage is still commonly believed and is very much a part of the American foundation myth. No doubt like most of his generation Tyson would have have seen the 1951 Bugs Bunny cartoon “Hare We Go” in which Bugs helps Columbus prove the earth is round in the face of a medieval king’s scepticism. And as recently as 1983, when Tyson was in college, Daniel Boorstin was able to write:
“A Europe-wide phenomenon of scholarly amnesia …. afflicted the continent from A.D. 300 to at least 1300. During those centuries Christian faith and dogma suppressed the useful image of the world that had been so slowly, so painfully and so scrupulously drawn by ancient geographers.” (The Discoverers, 1983, p. 100)
Boorstin goes on to pour scorn on the “legion of Christian geographers” who followed the path of the stupid sixth century flat-earther Cosmas Indicopleustes and so plunged Europe into this millennium of ignorance. So, for some at least, the idea of the medieval belief in a flat earth remains a useful stick with which to beat those detested “Dark Ages” and Christianity’s dead hand on “progress”.
Back in 2012 New Atheist blogger Donald Prothero took hold of the flat earth stick and gave Christianity a vigorous beating. Prothero is Professor of Geology at Occidental College in Los Angeles and he had just seen Alejandro Amenábar’s woeful tripe Agora, so naturally he felt these things qualified him to lecture the readers of Skepticblog about history. In a post entitled “Hypatia, Agora and Religion vs. Science”, he praised Amenábar’s highly distorted biopic of Hypatia and used that as a jumping off point for a sermon about the alleged suppression of science by religion that was peppered with classic New Atheist bad history howlers. As I’ve detailed elsewhere, the result was total butchery of the facts, but he finished in grand style, with a reference to “Christians suppressing the heretical notion that the Earth is round”, showing that the Medieval Flat Earth Myth is alive and kicking at the more clueless end of the New Atheist paddling pool.
And it’s easy to see why this myth is so hard for the New Atheists to resist – it conforms to every element of their pseudo historical metamyth. We have the wise and rational Greeks discovering the earth is a sphere using science. Then the terrible Christians destroying this knowledge (presumably by burning down the Great Library of Alexandria and murdering Hypatia), plunging Europe into a 1000 year Dark Age of Church oppression where the Bible must be interpreted literally at all times. And finally, a brave rationalist arising at the dawn of Modernity to boldly defy the Church proves the Greeks right by sailing to the Americas.
But those of us who actually care to check facts – something the New Atheists preach about but, strangely, rarely do on matters historical – know that this is all complete crap. Anyone who can bother to read Jeffrey Burton Russell’s Inventing the Flat Earth: Columbus and Modern Historians (1991), Google a Wikipedia article or even read Cracked.com can get a solid understanding of how the idea that the Medieval Church suppressed the concept of a spherical earth and taught that the earth was flat is a wholesale fiction that arose in the nineteenth century. They can read up on how, in 1828, the American novelist Washington Irving invented the whole idea of a conflict between the Church and Columbus to spice up the otherwise rather dull story in his fictionalised biography A History of the Life and Voyages of Christopher Columbus. This book, unfortunately, became the best selling biography of Columbus for the next century, and so fixed the myth in the English speaking world as something “everyone knows”. Despite the fact it was completely made up.
The Medieval Sphere of the World
In fact, the idea that the earth was a sphere was never disputed in the Middle Ages. The weird flat earth cosmology of the sixth century Byzantine writer Cosmas Indicopleustes, who Boorstin erroneously blamed for his alleged centuries of “scholarly amnesia”, was in fact virtually unknown even in the Eastern Roman Empire and was completely unknown in western medieval Europe. His obscure book did not appear in a Latin edition in Europe until 1706.
The writer who actually influenced western medieval thinking on the matter was Plato, because his Timaeus – the only Platonic dialogue known in the early medieval west and one of the most influential works throughout the period – stated categorically that the Creator “made the world in the form of a globe, round as from a lathe, having its extremes in every direction equidistant from the centre, the most perfect and the most like itself of all figures”. And if an authority as august as Plato said so, that, as far as most medieval scholars were concerned, was that.
Though after the influx of lost Greek learning via translations from the Arabic in the twelfth century, they were also well aware of the rational proofs of the shape of the earth established by the ancient astronomers and physicists. In his introduction to astronomy, the Tractatus de Sphaera (“Treatise on the Sphere” – the title is something of a hint), John Sacrobosco (c.1195- c.1256) gave several proofs of the shape of the earth:
“That the earth, too, is round is shown thus. The signs and stars do not rise and set the same for all men everywhere but rise and set sooner for those in the east than for those in the west; and of this there is no other cause than the bulge of the earth. Moreover, celestial phenomena evidence that they rise sooner for Orientals than for westerners. For one and the same eclipse of the moon which appears to us in the first hour of the night appears to Orientals about the third hour of the night, which proves that they had night and sunset before we did, of which setting the bulge of the earth is the cause.” (Sacrobosco, Tractatus, Ch. I.9)
He also shows how it can be known that the surface of the sea is, therefore, also spherical:
“That the water has a bulge and is approximately round is shown thus: Let a signal be set up on the seacoast and a ship leave port and sail away so far that the eye of a person standing at the foot of the mast can no longer discern the signal. Yet if the ship is stopped, the eye of the same person, if he has climbed to the top of the mast, will see the signal clearly. Yet the eye of a person at the bottom of the mast ought to see the signal better than he who is at the top, as is shown by drawing straight lines from both to the signal. And there is no other explanation of this thing than the bulge of the water.” (Sacrobosco, Tractatus, Ch. I.11)
Sacrobosco’s book was the standard text in medieval universities for anyone who studied astronomy, which was essentially anyone who took an Arts Degree. So the idea that the earth was round was so well known and unquestioned that Thomas Aquinas used it as an illustrative example of an accepted, objective and scientific fact:
“Both an astronomer and a physical scientist may demonstrate the same conclusion, for instance that the earth is spherical; the first, however, works in a mathematical medium prescinding from material qualities, while for the second his medium is the observation of material bodies through the senses.” (Summa Theologica, q.1, a.1).
In short, this was all standard, accepted and unquestioned as far as medieval scholars were concerned. As Stephen Jay Gould (a scientist who actually did bother to check his facts on history) summarised it:
” … there never was a period of ‘flat Earth darkness’ among scholars (regardless of how the public at large may have conceptualized our planet both then and now). Greek knowledge of sphericity never faded, and all major medieval scholars accepted the Earth’s roundness as an established fact of cosmology.” (Gould, “The late birth of a flat earth”, Dinosaur in a Haystack: Reflections in Natural History, pp. 38–50)
“But, what about … ?”
So that, you would think, settles that. But myths die hard and even those who are made aware of all the abundant evidence that this one is total bunk find ways to clutch at some straws. One such is to try to claim that while some or even most medieval scholars accepted that the earth was round, there were still a few who did not. And so it’s claimed that there was some kind of “dispute” over the issue. Some of those who try to argue along these lines point to assertions made in the Middle Ages about “the antipodes”, disputing that they exist. For example:
“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 on us, men who walk with their feet opposite ours, there is no reason for believing it.” (Augustine, De Civitate Dei, XVI.9)
In 748 AD Pope Zachary declared the belief “that beneath the earth there was another world and other men, another sun and moon” to be heretical and rejection of this antipodean world is found elsewhere in early medieval writings.
But these are not references to any dispute about the shape of the earth. These writers are echoing a dispute between ancient philosophers about whether the other side of the round earth could have its own lands and inhabitants. This was disputed on the grounds that the equatorial region was considered so hot that it was impassible, though for Christian writers it was also considered impossible because they believed mankind had been created in the northern hemisphere (with Eden being in the region of Jerusalem) and then spread out from Mount Ararat after the Great Flood. So Noah’s descendants could not have passed the equator to populate the southern hemisphere and any lands which may be there would be uninhabited.
As it happens, it was medieval travellers who ventured as far afield as Sri Lanka, Java and Sumatra by the thirteenth century that finally debunked the idea of an impassable equatorial zone and put the debate about the antipodes to rest. But the point here is that this dispute was not about the shape of the earth – on the contrary, it presupposed the earth was spherical.
“Okay, but what about … ?”
A few more tenacious defenders of the myth try even harder and come up with a passage from Isidore of Seville that they think is a clincher. Isidore’s Etymologiae was an encyclopaedia (of sorts) compiled by the sixth century bishop of Seville (c. 560-636) and organised according to his often highly fanciful etymologies for key words. Given that the early medieval period had very few such works of general reference, it was a widely copied and read text. Therefore if Isidore said the earth was anything other than round, surely this indicates that there was some dispute or doubt on the matter, at least in the early part of the medieval era. And some feel this passage indicates just that:
“It is in virtue of its circular form that we speak of the orbis terrae (orb of the earth), because it is like a wheel; hence the name for a small wheel is orbiculus. The ocean flowing around the land encircles its limits on all sides. It is divided into three parts, the first is called Asia, the second Europe and the third Africa.” (Isidore, “De orbe” in Etymologiae, XIV.2)
If here we have one of the most influential scholars of the early Middle Ages saying the earth is shaped “like a wheel” then surely this is clear evidence of at least some belief that it was something other than round, right? Well, actually, wrong. Sorry.
Elsewhere in the Etymologiae Isidore makes it clear that he understood the earth to be spherical. For example, here is how he defines and describes the heavens:
“The sphere (sphaera) of the sky is so named because it has a round shape in appearance. But anything of such a shape is called a sphaera by the Greeks from its roundness, such as the balls that children play with. Now philosophers say that the sky is completely convex, in the shape of a sphere, equal on every side, enclosing the earth” (Isidore, “De partibus caeli” in Etymologiae, XIII.5)
Obviously if the spherical heavens are enclosing the earth and are “equal on every side”, the earth too must be spherical. And in another of his works, De natura rerum, he makes the same point:
“The earth, as Hyginus states, is situated in the middle of the universe. Equidistant from all of [the universe’s parts] it occupies the centre. The ocean, spread out by the limit of the circumference of the sphere, bathes virtually the entire globe.” (Isidore, De natura rerum, XLVIII)
The explicit references here to “the sphere” and “the globe” here are quite clear. Finally he makes the point again in Book XIV, just before the “like a wheel” passage quoted above:
“The earth is placed in the central region of the [universe], standing fast in the centre equidistant from all other parts of the sky.” (Isidore, “De terra” in Etymologiae, XIV.1)
So what was he saying when he goes on to write in the next section of Book XIV that the “orbis terrae” is “like a wheel”? The key to understanding this apparent contradiction lies in the quote from De natura rerum above. He notes that the ocean “bathes virtually the entire globe”. This follows the Greeks, who thought that most of the earth was covered in ocean and that the three continents took up only a portion in the northern hemisphere, with the existence of any land masses in the southern hemisphere merely a conjecture, as discussed above. More specifically, following Aristotle, they held that the continents occupied the northern temperate zone, between the frigid arctic zone and the torrid and impassable equatorial one:
“If we put a man in any part of the world, and we draw the diameter of the earth passing from his feet to the other extremity of the earth, and through the centre of the earth, and if there is another man in that extremity which is touched by the other part of the diameter, those men, who are the diameter of the earth distant from themselves, are called the antipodes of each other.” (Tostado, Commentaria in Deuteronomium, Qaestio IV Cap. VII)
“I have often thought of a story I have heard, when I was young, of a worthy man of our country who went once upon a time to see the world. He passed India and many isles beyond India, where there are more than five thousand isles, and travelled so far by land and sea, girdling the globe, that he found an isle where he heard his own language being spoken…He marvelled greatly, for he did not understand how this could be. But I conjecture that he had travelled so far over land and sea, circumnavigating the earth, that he had come to his own borders; if he had gone a bit further, he would have come to his own district.”
“If you take an apple and hang it close to the flame, so near that it is heated, the apple will darken nearly half the room or even more. However, if you hang the apple near the wall, it will not get hot; the candle will light up the whole house; and the shadow on the wall where the apple hangs will be scarcely half as large as the apple itself. From this you may infer that the earth-circle is round like a ball and not equally near the sun at every point.”
“I neglected to mention that the “five-centuries” reference in my tweet the B.o.B refers to the dawn of the earliest maps of a spherical Earth. A time where all doubt was removed from the minds of cartographers. I am most fascinated by this transition of world view, before which everybody drew themselves in the center of a flat circle.”