>>Thank you for joining me in the History of Science Collections of the University of
Oklahoma Libraries. Let's see what stories are waiting for us from the vault that throw
light on the shape of the Earth.
In the late 20th century, members of the Flat Earth Society dismissed the evidence of photographs
of the Earth from space by insisting that the Apollo Moon Missions were a hoax.
In the late 19th-century, you could have read that the Earth is flat in The Zetetic Society
journal. "Zetetic" is is derived from a Greek verb
meaning "to seek" or "to inquire."
The Zetetic Society journal was founded to promote the ideas of this book, Zetetic Astronomy:
Earth not a Globe, published by Samuel Rowbotham in London, 1873 under the pseudonym "Parallax."
What is the story behind this book and this journal? Why did these moderns believe the
Earth was flat? Ironically, they were protesting against the evils of modernism and trying
to go back to an idealized, pre-modern past, in which they thought everyone believed the
Earth was flat. By the end of the 19th century, the view was
well entrenched that medieval people thought the Earth is flat. So Rowbotham felt bound
to agree, and promoted the anti-modernist idea of a flat Earth for many years as an
itinerant lecturer.
The first edition of this book in 1865 contained 220 pages. This second edition almost doubled
in thickness. In the copious additions, Rowbotham responded to various critics who (for some
reason) reviewed the first edition unfavorably. Rowbotham even issued a £1000-pound challenge
to anyone who could prove him wrong. Alfred Russell Wallace tried unsuccessfully to claim
that reward.
Yet the Zetetic Society and the Flat Earth Society are a modern development, not a medieval
or early modern movement. They arose in reaction to polarizing rhetoric about scientific authority
in the late 19th century. But most people cite them as proof of a pre-modern belief
in a flat earth, which they are not.
But didn't Columbus have to prove that the Earth is round? Actually, no. This mistaken
modern belief is the true "Flat Earth Myth."
The origin of the modern "Flat Earth Myth" lies in part with one of America's earliest
writers, Washington Irving. Irving's far-fetched Life of Columbus presented itself as biography,
not fiction. Unfortunately, it was about as factual as the headless horseman. Irving fabricated
a tale of Columbus pleading his case before a council of Inquisitors at a convent in Salamanca,
who assailed him with citations from the Bible and the teachings of the Church.
Irving's account is mischievous nonsense, which should have been read simply as a pleasant
romance. Other French and American writers endorsed
the Flat Earth Myth, and by the end of the 19th century, it was being taught in elementary
schools and universities.
In fact, medieval people, both the educated elite and the unlearned laity, knew the Earth
is round. Dante's Divine Comedy, for example, assumes the Earth is round.
Far from advocating a flat Earth, both Plato and Aristotle assumed that the Earth is a
sphere. Wherever their influence held sway, belief in a round Earth was not seriously
contested.
For Aristotle, the spherical Earth lies in the center of the universe. Surrounding the
Earth are giant celestial spheres. The large sphere containing the fixed stars
rotates around the Earth every 24 hours, while the planets are carried in spheres around
the Earth at different times. Don't confuse an Earth in the middle of the
universe with a flat Earth. The Aristotelian cosmos was centered upon the Earth, but the
Earth was a globe. Aristotle's theory of gravity stipulated that
the natural motion of every earthy body is straight down. So if earthy bodies are falling
straight down, then they will compact on every side. Aristotle's theory of gravity required
the Earth to be as round as a globe.
In another argument for the sphericity of the Earth, Aristotle argued from lunar and
solar eclipses. Now in Aristotle's day, the nature of lunar and solar eclipses was well
understood. In a lunar eclipse, the Sun, Earth and Moon line up on a straight line, with
the Earth in the middle. The Sun casts the Earth's shadow upon the Moon. By the 4th century
BC, continuous lunar eclipse observations from Babylon went back several centuries.
Now in every lunar eclipse, to observers located anywhere on the dark side of the Earth, north
or south, or east or west, the Earth's shadow on the Moon always appears curved.
If the Earth were flat or any other shape than a globe, at least some of these eclipse
shadows would be straight or angular. The curved shadow tells us that the edge of
the Earth is curved, no matter how the Earth's shadow is cast onto the Moon, from any angle.
Therefore, the Earth must be a three-dimensional globe.
We see the Earth's silhouette on the face of the Moon, so lunar eclipses prove that
the far side of the Earth is curved. It is not necessary to circumnavigate the
globe to behold with our own eyes that the Earth is a sphere.
So the Flat Earth Myth is not an alleged medieval belief in a flat Earth, but the mistaken modern
belief that medieval people thought the Earth is flat, when it's so easy to show that they
knew the Earth is round.
But myths have a life of their own. Have you seen this woodcut before? To me, this woodcut
means that we have set out on a journey of discovery and exploration. I think that is
the greatest appeal of the image and the reason it is so frequently reproduced. Yet most people
who see it also believe it is evidence for a medieval belief in a flat earth.
This woodcut adorns the jacket cover of the best-selling book, The Discoverers, by Daniel
Boorstin, a distinguished Librarian of Congress. In fact, you may visit Boorstin's library
here in the University of Oklahoma Libraries. Yet the inside flap of the book jacket credits
the artwork to an "early 16th century woodcut." This attribution is mistaken.
Similarly, J.D. Bernal, the great Irish scientist, published a monumental 4-volume history of
science. In the first volume, Bernal reproduced the woodcut, also attributing it to the 16th
century. Yet the woodcut is not from the middle ages
or even the 16th century at all. It dates to the late 19th-century.
It was created for this book, published in 1888, Camille Flammarion, The Atmosphere.
Camille Flammarion was the "Carl Sagan of the nineteenth-century," whose many books
inspired and informed a general readership. He bridged astronomy and popular culture.
Flammarion's books, published in both French and English, fill several shelves here in
the History of Science Collections.
And in this book, Flammarion created the woodcut to propagandize the Flat Earth Myth.
The woodcut has proven to be an extremely durable piece of visual rhetoric, often reproduced
by people who have no idea that it originated only in the late 19th century.
You may download a colorized version of the woodcut from our website and make a poster
or a coffee mug, or use it in whatever way you like.
Science is a story. What stories do you want to hear and tell about the shape of the Earth?