Category: Press and Public Understanding of Science

Astrolabes and S•Town

On Thursday, February 16, at 5:36 PM I was standing in a faculty meeting when my phone vibrated. I fished it out of my pocket and looked at the screen. I had just received a voicemail and a text from the same number, a number I didn’t recognize. The text asked, simply: “Is this the phone of Darin Hayton?”

I stepped outside and listened to the voicemail. The person identified himself as a researcher for This American Life, asked if he had reached Darin Hayton, and wanted to ask about astrolabes. His message sounded urgent. I was intrigued. Why would anybody feel a pressing need to learn about astrolabes, at 5:30 on a Thursday evening? And why would that person not just turn to Wikipedia or some other on-line resource?[1] So I decided to respond.

As I was still, at least physically, in a meeting, I texted rather than phoned and offered to call later that evening or the next morning. He asked that I call him as soon as I was free.

Texting with the guy who turned out to be a researcher for This American Life.
When I phoned he immediately started asking about astrolabes. He had clearly done some research on them but wanted to confirm what he had learned—e.g., Hipparchus had developed the mathematics but not an instrument; early instruments dated from the late 9th century; you could use it to tell time. He was particularly interested in developments introduced by 10th-century Islamic scholars. He asked about different innovations we might attribute to them and wanted to know how they improved the astrolabe. Most of the innovations he mentioned cannot easily or definitively be traced back to early Islamic instrument makers. We chatted for 10–15 minutes. As our conversation wound down, I tried to find out why he was so interested in astrolabes. He offered few details, saying only that he was doing research for an up-coming This American Life show on a man from Alabama who had studied astrolabes and had even built his own. He wouldn’t tell me the man’s name, but did mention that he had recently died.[2]

After we hung up I tweeted about my brush with fame. I am clearly a nerd since I think having This American Life phone me constitutes fame.

I tweeted about my brush with fame—clearly I’m a nerd because I think talking to This American Life constitutes fame.
Fifteen minutes or so later as I stood in my bathroom brushing my teeth, my phone rang again. Same guy confirming a couple points and asking if his formulation was correct. Something to the effect: the Greek astronomer Hipparchus developed the mathematics behind the astrolabe and 10th-century Islamic scholars refined it to time their daily prayers. Yes, I said, that’s fine.

Because I am always late to the party, I didn’t hear about S•Town until late April, a month or so after it was released and became an instant hit.[3] Finally, when a friend suggested I listen to it because they “talk about astrolabes,” I downloaded it and listened while I repaired my washing machine. Sure enough, about 15 minutes in John B. McLemore (the main character) mentions astrolabes:

Because kids are talking about getting girls, or deer hunting, or football. Whereas I was interested in the astrolabe, sundials, projective geometry, new age music, climate change, and how to solve Rubik’s cube.


But he doesn’t say much more. Then, 30 minutes later, the astrolabe suddenly returns in the context of telling time.[4] Brian Reed, the host, reflects on various methods for tracking time, then describes the astrolabe:

BRIAN REED: The astrolabe looks kind of like a clock crossed with a compass. It’s a flat dial with a map of the night sky laid over it, and a pointer, or I guess a sight, attached on top of that. You pick a star in the sky, and aim the sight at it, twist the sky map until it aligns with the sight in a certain way. And then the dial shows you your direction, as well as the month, day, and time.

It’s a beautiful, complex device. And as a kid, John longed to figure it out, to put himself inside the brains of the people who puzzled through the earliest versions—the Greek astronomer Hipparchus, who devised the mathematics behind it, or the 10th century Islamic scholars, who refined the invention to help them time their daily prayers.

John wanted to go through what they had to go through to create an astrolabe. Which is why he made his own, designed specifically for the coordinates of this house. It hangs on the wall of his mother’s bedroom. That’s what he’s showing me, his astrolabe, when Skyler Goodson happens to walk in the front door.

When I heard this, I immediately recalled the man who had phoned six weeks earlier asking about astrolabes. There, in Brian Reed’s brief description, was the final version of what the man on the phone had crafted. It turns out that the man on the phone had been doing research for S•Town.

Thanks to S•Town and John B. McLemore, astrolabes are enjoying their 15 minutes of fame. Reddit pages on S•Town have astrolabe discussions. Websites promise to show you “How to Build an Astrolabe Like John B. McLemore From ‘S- Town’.” S•Town fans are turning up in museums asking to see astrolabes.

Visitors to Harvard’s museum are S•Town fans and want to see astrolabes.
Hey This American Life, perhaps you would like to do a whole show on astrolabes. While not as eccentric as John B. McLemore, I have built my own astrolabe, I know its history better than most, and I’m available. Your researcher/fact checker has my number. Have him give me a call.


  1. In talking to him, it seems he started with on-line resources, including my An Introduction to the Astrolabe.  ↩
  2. He probably used a euphemism, but somehow I think John B. McLemore would have preferred “died,” and I prefer it.  ↩
  3. And because I can’t just be late to the party, I find out late that I am late to the party, I learned about S•Town while listening to an old podcast of Wait Wait…Don’t Tell Me featuring Sarah Koenig[3a] that I had downloaded and then didn’t listen to for nearly a month. And even then I was in no hurry to listen to S•Town.  ↩

    3a. I should probably point out that the name Sarah Koenig meant nothing to me because I am one of perhaps only a handful of people, including John B. McLemore, who has never listened to Serial and only vaguely knows what it is.  ↩

  4. To be exact, Brian Reed’s description of the astrolabe comes at 44:05 into chapter 1. Astrolabes are mentioned in two other places: the first time is about 16 minutes into chapter 1; the last time is 2:35 into chapter 7. I don’t think I would say, as my friend did, that they “talk about astrolabes” in S•Town, but any popular culture reference is better than none.  ↩

Yet Another Flat Earther

In a footnote to a previous post I worried that in a post on Columbus and the flat earth myth Valerie Strauss had preferred the opinions of a mathematician over the expertise of a historian. And in fact, Strauss did prefer the dilettante to the expert. She rejected the historian’s conclusions, which were based in training, evidence, and experience, and relied instead on the opinions of a non-expert, which ignored both evidence and experts.

Perhaps because she is awed by mathematics or assumes scientists are smarter than everybody else, Strauss aped the mathematician Robert Osserman’s fantasy about people in the early middle ages believing in a flat earth. Osserman was an accomplished mathematician at Stanford. He was also celebrated for bringing “math to a broad audience.” Turns out, he also happens to have been a flat earther.

Rober Osserman’s Poetry of the Universe

For reasons that make little sense, Osserman repeats a particular version of the flat earth myth in his Poetry of the Universe. Chapter 2, “Encompassing the Earth,” opens with a rejection of the idea that Columbus proved the earth was round. Osserman even calls out this myth, saying

One of the enduring myths of the Western world is that in order to gain support for his expeditions, Christopher Columbus had to first overcome a pervasive belief that the earth was flat rather than round …

So far, so good. But then Osserman succumbs to the fantasy,

The myth undoubtedly stems in part from a compression of the historical past, conflating the early Middle Ages, when a belief in a flat earth was indeed widespread in Europe, with the late Middle Ages…

Osserman too traffics in the flat earth myth.

No, the myth doesn’t stem from a “compression of the historical past” but rather a willful rejection of the historical past, a willful rejection of historical fact, a willful rejection of evidence, and a profound intellectual laziness validated by arrogance and hubris. I am confident that Osserman had multiple colleagues at Stanford who could have explained to him how his beliefs were wrong, were myths. All he had to do was dial an extension or walk across campus and ask them. But he chose not to. He chose, instead, to traffic in a myth, to spread misinformation, and to do so with the authority of being a “mathematician.”

That authority was persuasive. It dazzled Strauss and convinced her to reject the expertise of the historian in favor of the unfounded beliefs of the mathematician. Her preference for the mathematician has, in turn, disseminated the myth yet further, now robed in the authority of a Washington Post column that claims to be grounded in research and to be a resource for teachers and parents. Unfortunately, Strauss has mislead the teachers, parents “(and everyone else)” who reads her column.

Another Flat Earther

I marvel at the power of that old chestnut about people in the middle ages believing the earth was flat. Even a person who rejects the myth that Columbus proved the earth was a sphere nevertheless trots out the poor, benighted medieval Europeans as believers in a flat earth. Consider, for example, Valerie Strauss’s post for the Washington Post: “Busting a myth about Columbus and a flat Earth.” Despite the promising title, she traffics in one of the typical versions of the flat earth myth.

Strauss celebrates scholars in antiquity who knew the earth was a spherical. Aristotle, Euclid, Ptolemy, these people got it right. Medieval Europeans, however, were apparently not so bright. On the basis of no evidence, she claims:

During the early Middle Ages,[1] it is true that many Europeans succumbed to rumor and started believing that they lived on a flat Earth.

In her story, medieval Europeans were back on the right track by the 1200s CE, when texts like Sacrobosco’s De sphaera “discussed the Earth’s shape.”

Strauss has no excuse for making this claim. She is simply and demonstrably wrong. And she should know it.

Strauss cites Jeffrey Burton Russell’s book, Inventing the Flat Earth, implying that she has read it. If she has, she can’t also believe that people in the early middle ages thought the earth was flat. If she has read even the first 30 or so pages of Russell’s book, she will recognize her version of this myth as one of the most common. Russell spends some time surveying this form of the flat earth myth:

Another version of the Error is that the ancient Greeks may have known that the world was round, but the knowledge was lost (or suppressed) in medieval darkness.… Many inconsistent varieties of this version exist: The knowledge was lost in the first century A.D., or the second, or the fifth, or the sixth, or the seventh; and on the other end it was lost until the fifteenth century, or the twelfth, or the eighth. The mildest variety, therefore, posits only a few years of darkness from the flattening of the Greek earth to the rounding of the modern one.[2]

Yet Strauss seems as committed as ever to a Dark Ages model of history, complete with its flat earth fantasy.[3]

Orlando Ferguson’s amazing map of a flat earth, from 1893.

Two further thoughts:

First, I am particularly worried because Strauss’s myth-busting post appeared on her regular column, “The Answer Sheet,” which she characterizes as a “A school survival guide for parents (and everyone else).” How many parents and everyone else’s have read and been misinformed by Strauss’s “survival guide?” At least one other person has read, believed, and repeated Strauss’s claim about medieval Europeans thinking the earth was flat.

On April 15 the anonymous blog, “Today in History,” posted “Columbus’s Flat Earth.”[4] Borrowing closely from Strauss, the author asserts:

Since Columbus owned a copy of an ancient Greek book [i.e., Ptolemy’s Geography] that outlined the reasons why the earth must be round, he did not believe that the earth was flat. So did anyone ever believe that the earth was flat? Actually, yes. During the Middle Ages in Europe, many people began to believe the rumors that the earth was actually flat.

Actually, no. During the Middle Ages in Europe, almost nobody began to believe or likely even heard any rumors that the earth was actually flat. The person who runs “Today in History” claims to be “someone who love history” and is “passionate about learning” and hopes to “provide more insight into event in the past.” Alas, duped by Strauss’s “survival guide” the person who runs “Today in History” is passing on misinformation and falsehoods.

Second, I also worry that Strauss believes expertise in mathematics is somehow a) applicable to other, non-scientific domains of knowledge and b) superior to historical expertise. Why else would she gratuitously cite a mathematician for evidence that “Columbus did not worry that he would fall off the Earth’s edge.”

On the one hand, Strauss’s post reflects willful ignorance and dogmatic rejection of evidence. On the other hand, Strauss’s post reflects historians’ failure to dispel this myth. Despite all our ranting and raving, we historians have failed to communicate with audiences, e.g., scientists, journalists and authors, politicians, educators, etc. I have fared no better in various efforts to combat this myth (some of which you can find by searching this blog for flat earth).

I am going to give it another go next week, at Taste of Science Philadelphia, where I am speaking along with climate scientists at “Climate change: How we got here, and looking to the future.” Maybe lubricated with some beer and good food I’ll have better luck.


  1. I can only guess that Strauss means by “early Middle Ages” some portion of the millennium between Ptolemy and Sacrobosco.  ↩

  2. J.B. Russell, Inventing the Flat Earth (1991), 28–29.  ↩

  3. Perhaps the other book Strauss cites, R. Osserman, Poetry of the Universe makes this asinine claim. I haven’t had a chance to look at it. If it does, and if she preferred to accept the comments of a mathematician over those of a historian, i.e., to accept the opinion of a non-expert over the knowledge of an expert, we have other problems.  ↩

  4. The “Columbus’s Flat Earth” post linked to my “Washington Irving’s Columbus and the Flat Earth,” which led me to Strauss’s post and, in turn, prompted this current post. ↩

Flat Earth Globe!

“As part of Groupon’s commitment to science,” the online coupon site offered on April 1 a special on 2-D, flat earth globes.

Groupon’s 2-D, flat earth globe, showing the wall of ice we’ve been tricked into thinking is polar ice caps.

The description neatly poked fun at the recent NBA fad to claim the earth is flat—gotta like referring to Shaquille O’Neal as “The Big Aristotle”—as well as conspiracy theories about NASA hiding evidence that the polar ice caps are really ice walls around the rim. I guess we’ll find out when they melt.

The Groupon page advertising the 2-D, flat earth globe, complete with description that mocks NBA players and conspiracy theorists.

Sadly, it is no longer available. But if you really want one, contact me. I along with more than 680 other people downloaded the PDF. In case you missed it, I covered the PDF to a JPG (option-click or right-click to download).

Atlas Obscura but Not So Accurata

Atlas Obscura seems to have reached a point that it no longer can describe itself as, well, obscura. The website enjoys more than 300,000 pageviews each day and has produced a book, which is currently the “#1 Best Seller in General Travel Reference” and #293 overall at Amazon. While individual entries might be, physically, off the “beaten path,” they are smack in the center of the virtual beaten path. Given Atlas Obscura’s place in popular culture, and our current anxieties about misinformation, it would be nice if Atlas Obscura tried to ensure it provided accurate information. Regrettably, the one entry I happened to check, the “Rosicrucian Pyramids of Bucks County,” seems to be a hodgepodge of misunderstood and misreported information, historical errors, and factually incorrect statements.

Atlas Obscura’s popup promises to escape the beaten path.
When Atlas Obscura promises to “escape the beaten path,” does that also mean the beaten path of facts?

By looking at two paragraphs from the post—one that purports to provide historical information and one that purports to describe observable facts—we see an author who doesn’t try very hard to distinguish fact from fiction and a website that doesn’t care enough to factcheck its posts.

First, a paragraph drawn from history:

Inspired by the idea of a secret society of learned men, astronomers such as Johannes Kepler, Georg Joachim Rheticus, John Dee and Tycho Brahe formed an actual society, known as the Invisible College, to acquire knowledge through experimental investigation. It would eventually become the Royal Society.

Well, no. Insofar as “the Invisible College” existed, it was an informal network of scholars in the latter 1640s, long after Rheticus, Brahe, Kepler, and Dee had all died. Its connection to the Royal Society is a myth, as Charles Webster pointed out four decades ago.[1] More recently, Lauren Kassell has stated unambiguously:[2]

The once common but erroneous identification of the Invisible College as an antecedent of the Royal Society derives from Boyle’s eighteenth-century editor Thomas Birch. There is now thought to be no link between Boyle’s ‘college’ and the philosophical society …. It is this group, with which Boyle became associated during the 1650s, that is regarded as the precursor to the Royal Society….

If the author of the Atlas Obscura post had looked at the Wikipedia entry on the Invisible College, which cites Lauren Kassell’s entry, perhaps we wouldn’t be reading this myth yet again.

Some of the problems in this paragraph that described the pyramids.

Second, the description of what can be found on the property is riddled with problems:

…the Fraternitas Rosae Crucis … settled in Pennsylvania, and today owns land in Bucks County on which three Rosicrucian pyramids sit. The headquarters of the Fraternitas Rosae Crucis, besides the three temples, it includes a number of normal buildings and “The Beverly Hall,” a large stone building named after the fraternities founder Paschel Beverly Randolph.
Surrounded by “No Trespassing” signs, the pyramids are aligned smallest to largest and covered in Rosicrucian symbolism inside and out, including images of a winged world crowned by a skull and crossbones, and the infamous pyramid with floating eye…

Um… no. There are four pyramids, not three. Only one is large enough to enter and could be mistaken for a temple, though it seems more likely a mausoleum or similar memorial. Two resemble garden fountains that stand 4–5 feet tall (when I visited only one was functioning). The smallest pyramid seems to be a pedestal type decoration. As of a year ago, there were no “No Trespassing” signs (there weren’t any the first time I visited either).[3] Finally, the pyramids are all but unadorned. They certainly are not “covered in Rosicrucian symbolism inside and out.” The largest, the mausoleum (?), has some brass plaques on the outside that list names of deceased members, and you can see a few decorative plaques inside that do have some Rosicrucian symbols on them.

Much of this paragraph seems to be an exaggerated and enthusiastic mélange drawn from Weird Pennsylvania, pp. 55–56. Other parts of the post weave together fictions from history, on the one hand, and fanciful Rosicrucian mythologies, on the other. Disentangling the history from the mythologies of the Fraternitas Rosæ Crucis is a challenge—clearly too much work for the author of the Atlas Obscura post. But it shouldn’t be too difficult for the author get the easily verifiable history correct or to stop short of making things up. For a brief post on the local Rosicrucians and some photos of these pyramids, see “Pyramids of the Fraternitas Rosæ Crucis.”

Perhaps this entry on the Rosicrucian pyramids is aberrant. Perhaps all the other posts are accurate. Or, perhaps, Atlas Obscura should be rebranded Atlas Obscura but Not So Accurata.


  1. Even Frances Yates, who was particularly adept at finding Rosicrucians, did not link Rheticus or Brahe to Rosicrucians or invisible colleges. Dee, to be sure, figured large in her discussion of Rosicrucians. And Kepler was an odd case, whom she called “a heretic from Rosicrucianism” (F. Yates, The Rosicrucian Enlightenment, p. 223). More typically, Samuel Hartlib, Jan Comenius, and Robert Boyle are associated with the Invisible College. Yates devotes a chapter to the relationship between the invisible college and the Royal Society. Charles Webster refutes this Rosicrucian association. He finds, instead, a network that includes Boyle as well as other lesser known physicians and Baconian-minded experimentalists. The role of “the Invisible College” has all but disappeared from recent histories of early modern science, e.g., Wootton’s The Invention of Science all but omits it (I found only a passing reference on page 341 to “an ‘invisible college’” as a correspondence network).  ↩

  2. See Lauren Kassell’s entry “Invisible College” for the Oxford Dictionary of National Biography (paywall).  ↩

  3. I suppose it’s possible that they’ve surrounded the place with “No Trespassing” signs, but given the other factual problems with this post, I’ve no confidence the author happened to get this right.  ↩