The Myth of the Flat-Earth Myth

Science

by Noah Beck

If, like me, you grew up in the 1980s and ’90s, you learned from your teachers, your textbooks, and perhaps a TV/VCR combo that rolled into the classroom on a giant cart that Christopher Columbus set sail in 1492 for the east by heading west, proving once and for all that the earth was round. The scene might be emblazoned in your mind as it is in mine: a young and brave Columbus standing before a dark and brooding council of hooded theologians, each of whom believed the earth was some kind of cosmic pancake, endeavoring to prove to them through logic and reason that they live on a sphere.

There is one problem with that scene: It’s a myth. Humanity had never held the idea that the earth was flat. No educated person, no scholar, no university, no sailor, in Columbus’s day or before, believed in a flat earth. In fact, the Greek mathematician Eratosthenes not only knew the earth was spherical, he calculated its circumference by measuring a stick’s shadow in Alexandria on the summer solstice and knowing the distance south to Syene, where the sun was directly overhead. His calculation was within 10% of the value we know today. He even went on to measure the tilt of earth’s axis within a degree and the length of the year as precisely 365 ¼ days. As you can tell by his name, Eratosthenes was no modern thinker or even a contemporary of Columbus. This was in 240 B.C.

Surely, then, it must be that the ancient Greeks were enlightened, and Columbus and his Renaissance contemporaries were ushering in a rebirth out of what must have been dark ages in between, no? Actually, the phrase “Dark Ages” was coined by the Italian writer Petrarch in the 14th century. Petrarch, among other humanists of his day, denied the scientific, artistic, and philosophical advancements of the previous 1,000 years. From his vantage point in Italy, he yearned for the glory of the Roman Empire before its division and the subsequent fall of the west. In his book, Inventing the Flat Earth, historian Jeffery Burton Russell writes, “The Humanists perceived themselves as restoring ancient letters, arts, and philosophy. The more they presented themselves as heroic restorers of a glorious past, the more they had to argue that what had preceded them was a time of darkness.” Petrarch loved traveling to Europe to rediscover and republish classic Latin and Greek texts. But whom did he think had maintained and meticulously transcribed them for the past 1,000 years? In reality, the “Dark Ages” (a concept we also learned in elementary school) were not so dark after all.

Some 300 years hence, Petrarch’s influence was obvious in the pseudo-historical writings of Washington Irving. Irving, one of America’s most popular writers in the early 19th century, is best remembered today for his short stories “Rip Van Winkle” and “The Legend of Sleepy Hollow.” It’s less widely remembered that while he was traveling in Europe in the 1820s, Irving gained access to a massive archive of Spanish history, and set out to write a multi-volume biography of Columbus. But finding the real story of Columbus a tad dry, Irving fabricated the flat-earth myth and promoted the reason-versus-religion narrative that accompanied it. The semi-fictional account was passed off as a faithful biography, and it was the most popular biography of Columbus for the next 100 years. Drama sells.

What is perhaps more interesting than the genesis of this myth is its persistence. Why do so many people still believe it? It is because we humans seek patterns and order in this world. Facts, ideas, and experiences bombard our brains every hour of every day. Unless we are consciously curious and open to conflicting narratives, our default is to accept the ideas that fit our predetermined worldview and to discard the rest. In the case of the flat-earth myth, by the turn of the 20th century the conventional worldview in Europe and America was one of ongoing war between science and religion. For much of the population, religion had been relegated to mere superstition that belonged in the past and science promoted to the only source of truth. From such a lopsided epistemological framework, a rational and scientific Columbus confronting unenlightened medieval Christians fits the boxes already present in one’s own mind and is readily accepted as truth. As this myth became more widespread during the 20th century, medieval historians and historians of science presented ever-increasing empirical evidence of its falsehood, but to no avail. In an ironic twist, our desire for such stories that fit our worldview won out over evidence and logic. This is an all-too-common story in human history: tidy convenient narratives winning out over facts.

Lest we arrogantly sit in judgment against the champions of progress or religion’s supposed scientific enemies for peddling false narratives, we ought to remind ourselves of how easily susceptible religious communities are as well to such dubious storytelling. The lesson is that everyone is vulnerable to warping the truth to fit a story that promotes them, their tribe, and its values. Religion is the usual suspect in this offense, but the Columbus flat-earth myth demonstrates that science can succumb to the same. Perhaps it is harder to be objective, neutral, and scientific than we imagine.

The real story of Columbus is much less exciting. The debate over his travels was not about the shape of the earth, but rather about its size and the relative positions of the continents. The best estimates of his day (dating back to Ptolemy in the 2nd century) were that the known world of Europe, Asia, and Africa measured 180° in longitude. The other half of the planet was ocean to be traversed. Eager to get on his way with the crown’s support, Columbus used a more generous (and generally rejected) 225° across. He added 28° more based on Marco Polo’s travels, fudged Japan out another 30°, and gave himself another 9° for leaving from the Canary Islands. On top of spacing out the known world, he made some unit errors in his assumptions of the curvature of the earth, making the planet about 25% too small. At the end of the day, Columbus estimated a voyage of just 2,400 miles to reach Japan—less than a quarter of the actual distance of 10,600 miles. With his crew on the verge of starvation when they happened upon the New World, Columbus turned out to be very wrong, but very lucky.

The modern flat-earth myth, which held that ancient and backward societies thought the earth was flat until Columbus proved otherwise is, after thriving for hundreds of years, at last finding its way to the scrap bin of human ideas. The idea of a medieval “dark age” is slowly following. Unfortunately, some of the other myths that go along with these—the notion that social progress is clean, linear, and always easy to recognize, or that science and religion are diametrically opposed—have so far proven more durable. But while we hope for the day when those, too, are discredited, we can also take away some lessons here for our own lives. The historical arc of the flat-earth myth might remind us to be more humble and to hold our own assumptions a little more lightly. It may remind us to look for wisdom in both ancient and modern sources. And it should certainly alert to be skeptical about simplistic stories—especially when they tell us what we want to hear.

Noah Beck is vice president of active equities at the investment-management firm Research Affiliates. He previously worked as a rocket scientist at Boeing and studied science and religion at Fuller Theological Seminary. He lives with his wife and three children in Laguna Nigel, California.