My scholarly identity hinges on bringing my expertise to diverse and varied audiences. Consequently, you will find me offering evening, continuing education classes, public lectures, consulting with television programs, presenting at academic conferences, and even on stage with comedians. I work to make the history of science accessible and available. I am happy to bring my expertise to any audience. Just ask.

Below are some places I’ve turned up (jump to Academic Lectures or Comedy):

Public Education & Public Lectures

Plagues and Epidemics in History

Epidemics seem to burst onto the historical scene unannounced, killing with complete impunity aristocracy and paupers alike. Through a series of case studies, this course analyzes the impact of epidemics on human societies, including mortality rates, efforts to contain the contagion and the infected, attempts to treat the purported illness, and expressions in art and literature. Examples will concentrate on pre-modern epidemics, from the Plague of Athens in the fifth century BCE through the great medieval plagues and the French Disease (typically equated with syphilis) to the late, major plague outbreaks in the seventeenth century. The course will conclude by looking at more recent epidemics, Yellow Fever in eighteenth-century Philadelphia and Typhoid Mary in early twentieth-century New York.

A free lecture course, offered evenings at the Free Library. Supported by The Wagner Free Institute of Science.

Great Books of the Scientific Revolution. A History

Viewed from the 21st century, the Scientific Revolution is readily reduced to a series of titles that stand in for revolutionary (and modern) ideas. Copernicus’s “De Rev” is the origin of the heliocentric system or Newton’s “Principia mathematica” not only gave us gravity but also modern, classical physics. In this approach, we tend to forget that these are titles of books, i.e., of physical objects that were the product of considerable effort by authors and printers, and that were purchased and read by people who were often authors themselves. In other words, we lose sight of the history of these books. This course seeks to retell the familiar history of the Scientific Revolution through a series of biographies of the books we most commonly associate with that revolution. We will try to see the content of each book as part of a broader set of questions, and we will try to understand the various motivations and anxieties that animated those questions. Further, we will investigate the publishing history and dissemination of the books to get a better sense of who read these books, how they came to see certain ideas in them, and how they responded to those ideas.

A free lecture course, offered evenings at the Free Library. Supported by The Wagner Free Institute of Science.

History of Cartography from Antiquity to Longitude

Today perhaps more than ever before we interact with maps through our in-dash GPS systems or Google Earth in our pockets, rarely to we pause to think about how maps are functioning. Maps are complicated and confusing instruments that function on many levels. We often don’t appreciate how maps are doing much more than simply indicating how to get from point A to point B. They continually and silently shape how we view the world. Rather than consider maps as more or less accurate depictions of the earth or as tools showing us how to get to our destination, over the next few weeks we will try to understand maps as instruments produced by particular cultures and societies to answer specific questions or address specific needs. As the questions and needs changed, cartographers adapted their maps accordingly. We will look at some of the narrative, political, religious aspects of maps. We will also work through the often sophisticated mathematics and geographic knowledge that undergirded cartographic projects, from antiquity to the 18th century when people finally solved the longitude problem.

A free lecture course, offered evenings at the Free Library. Supported by The Wagner Free Institute of Science.

Cosmos: A History of Modern Astronomy

When astronomers in the early 17th century turned the newly-invented telescope at the heavens, they saw things people had never seen before. These new observations challenged accepted ideas about the size, age, and very nature of the universe, as well as our place in it. From Galileo’s discovery of the moons of Jupiter, to Herschel’s discovery of Neptune, to Hubble’s discovery of the expanding universe, astronomers have challenged our comfortable assumptions about the universe. This course will focus on the work of some of these astronomers and the key problems they tried to solve. We will also see how astronomy promised to solve mundane, practical problems that were very important to governments, such as standardized time and commerce.

A free lecture course, offered evenings at the Free Library. Supported by The Wagner Free Institute of Science.

Cosmos: A History of Early Astronomy

The history of astronomy is a journey through foreign lands populated with cultures that struggled to understand the heavens, as we still struggle to do today. But when peoples in the past looked up, they saw a different sky, they asked different questions, and they looked for different answers. This course will explore some of these cultures to learn why they invested considerable time and effort in studying the heavens and the uses to which they put their knowledge of the stars and planets. Our journey will take us from early Babylonian clay tablets to a solar system that looks vaguely familiar. Along the way we will look at horoscopes, priceless instruments, medieval maps, and calendars.

A free lecture course, offered evenings at the Free Library. Supported by The Wagner Free Institute of Science.

Almanacs, Stars, and the Popular Press

As part of the “History After Hours: Seafarers and Stargazers!” program at the Museum of the American Revolution, I spoke about almanacs and astrology in 18th-century Philadelphia and the Mid-Atlantic region. Inexpensive and printed in huge numbers, annual almanacs have for centuries been widely trusted sources of knowledge about the natural world. Their pages are filled with meteorological predictions, astronomical and astrological information, and guidance for health and wellbeing. These almanacs offer us a window into daily life and shared beliefs about science and, at the same time, reflect the ways those beliefs were slowly changing, or not.

Measuring the World With Second Graders

One sunny Thursday in the fall I taped/glued gnomons (little sticks) to large, inflated exercise balls. I took my model earths to a local grammar school where I met a class of second graders and helped them recreate Eratosthenes’ method for calculating the size of the earth. The previous Thursday I had visited their classes and explained who Eratosthenes was and how he had calculated the circumference of the earth. This week we got to go out and try it ourselves. Divided into small groups, I sent them off with a model earth and a set of instructions (here’s a jpg of the instruction sheet).

Read more at “Eratosthenes and Second Graders” and my thoughts “Taking History of Science to Them.”

A Biography of Humoral Medicine

As part of a mini-course on the history of medicine, I spoke to middle school students about the theory of humoral medicine from antiquity through Benjamin Rush. We talked about what the humors were and how they seemed to be related to certain season, how physicians tried to regulate the humors through diet and activity, how physicians resorted to more interventionist techniques such as purgatives and the ever popular bleeding, and how bleeding patients was perfectly reasonable in this context. The students got a chance to read and wonder at clinical observations from the medieval world. All this was in preparation for a visit to the Mütter Museum.

The Black Death

I had the opportunity to speak to a local 6th-grade about the black death—its purported origin, spread, and guesstimated mortalities. The best part was giving them a chance to hear contemporary accounts about the advent, spread, treatment, and prophylactics measures. I used the occasion to make a short movie illustrating the spread of the plague from 1346 until 1351 (see here). They asked some great questions about how and why it began, how we know, why it spread so quickly, and why it died out.

“What is an Astrolabe and How is it used?”

I spoke to 4th graders at Friends’ Central School on astrolabes, scientific instruments, and the history of science more broadly. See “Taking the History of Science to ‘Them’” for why I feel this outreach is so important.

Astrology, Kingship, and Scientific Advisors in Fifteenth-Century Hungary

I spoke to a great audience of former scientists, academics, and interested people at The Quadrangle, a local senior community. Using astrology in Renaissance Hungary as an example, I outlined how Matthias Corvinus, the Hungarian King, used his patronage of astrology and astrologers as a mechanism for asserting his authority and shoring up his right to rule. In this we see, I argued, an early example of a prince publicly relying on scientific advisors to accomplish his political and dynastic goals.

Academic Lectures

Ps-Ptolemy’s Ὁ Καρπός and Byzantine Astrological Practice

The collection of astrological aphorisms that circulated under Ptolemy’s name raises a number of questions about the practice of astrology in the later Byzantine empire. The form and the content of the collection points to a thriving culture of astrology, one that possibly included social performances. In this lecture I will explore the various facets of this text — e.g., its material history and circulation, the aphorism as a form of authority and knowledge making, the arrangement and content of individual aphorisms and their sequence — in order to articulate some of those questions about the culture of astrology and to suggest some possible answers. Parts of this lecture will be speculative, but I hope generatively so.

Planetary Conjunctions and Politics, Or Something Like That

I’ve been invited to speak at the conference, “On the Political Skies: Harmonies between Heaven and Earth,” happening in May 2020. I don’t yet know what, exactly, I will talk about. Stay tuned. Clearly this was cancelled.

Constructing Astrolabes in 14th-Century Constantinople

I was invited to speak on astrolabes in the medieval Greek context. I traced the history of texts on constructing astrolabes, or texts that indicated there was some knowledge of how to construct and use astrolabes, with a focus on the latter Byzantine period. This lecture was part of the “Astrolabes in Pre-Modern Cultures,” presentations hosted by the Insitut für Jüdische Studien, at WWU Münster.

The Case of the Missing Byzantine Astrolabes

At a recent DVMA meeting I spoke about Byzantine astrolabes. Or rather, I spoke about the lack of Byzantine astrolabes and wondered aloud about how to account for their absence. Why, in other words, does only one astrolabe (and a part of a second) survive from the Greek empire while hundreds survive from the Islamic and Latin worlds? Spoiler alert: I don’t really know, but I suggested some plausible ideas.

I not only enjoyed airing my thoughts, I benefitted from the audience’s insightful questions and the conversations that followed. Thanks to everybody who participated.

Byzantium: The Other East

In November I participated in an excellent panel on “Re-Thinking Medieval and Early Modern Science” at the History of Science Society annual meeting. I spoke on Byzantine science, which does not fit neatly into our standard histories of science. To the extent that we recognize any Byzantine science, it is neither properly “east” nor properly “medieval.” Moreover, Byzantine scholars were not particularly innovative, preferring to comment on Plato an Aristotle in archaic Greek. Beyond preserving various classical texts, they contributed little to the development of science. We too readily dismiss Byzantine science because it does not contribute to scientific progress. I suggested that we should take Byzantine science more seriously. If we see the production of scientific knowledge as a culturally meaningful activity, Byzantine science is interesting precisely because its relevance does not derive from technical innovation or scientific progress.

Numbering Our Days in Sixteenth-Century Europe

We’ve long recognized the transformative role that the clock and keeping time played in regulating society. I want to ask about a similar role for calendars. The spread and success of print in the 16th century made yearly calendars increasingly common. In addition to seemingly banal quantified information, e.g., what year it was, these calendars contained an array of more personal, quantified guidelines: when to let blood, when to bathe, or wean a child. What happens when people begin to rely on these calendars to regulate their activities? And what happens when that regulation becomes centralized and standardized?

Historians of Science Watching COSMOS

I joined a roundtable discussion at the History of Science Society’s annual meeting to discuss the challenges and opportunities that last year’s COSMOS presents. Historians of science, often a nitpicky bunch, alternately derided and praised the show. We at the roundtable tried to move beyond mere criticism and think about how we could use COSMOS’s strengths and weaknesses as an opportunity to contribute to a wider discussion about the history of science.

“Politics as Astrological Expertise in Renaissance Hungary”

I spoke at the Renaissance Society of America annual conference on how politics shaped scientific knowledge in Renaissance Hungary. By examining how and why the Hungarian King Matthias Corvinus enlisted scientific authority, we can see how the exercise of political authority establishes scientific authority and, in turn, how scientific authority is used to legitimate political authority.

“Empiricism, Prediction, and Instruments: The Creation of Expertise in 14th-Century Constantinople”

I spoke at Penn on technical expertise in Byzantine politics. This presentation examines how Nikephoros Gregoras constructed his technical expertise and how he defended it against competing claims to expert knowledge.


On the World Cafe Live stage (April 2014)

Sounds Made Up (True) Tales from the History of Science

Once again I had the chance to work with Secret Pants, a local group of comedians, to put together a show that takes a lighthearted look at episodes from the history of science. This year I will be talking about 17th-century extraterrestrials. Three other historians—returning again are Elly Truitt, and Mike Yudell, and newcomer Audra Wolfe—will pair up with other comedians for a two hours of fun. Sounds Made Up has become one of the most popular parts of the Philadelphia Science Festival. Buy your tickets here and come learn a little about the history of science and have a good laugh at the same time.

Philadelphia Science Festival: “Sounds Made Up: Tales from the History of Science” (April 2013)

I once again had the opportunity to take part in the Philadelphia Science Festival’s program that pairs local historians of science with local comedian. As with previous shows, we once again had a great time dragging history of science into a new forum and bringing it to a broader audience.

“Life, Sex, Death and Food: A Historical Look at the Science That Drives Us”

Another performance at the Philadelphia Science Festival. Once again, historians of science were paired with comedians from the Philadelphia Improv Theater to explore in a humorous and serious way episodes from past science. I spoke about a woman who in 1569 gave birth to a cat, a hairless, dead cat. For more information and tickets, see here.

Seemed Right at the Time?! Scenes from Science Past

The first of a number of performances at the Philadelphia Science Festival. I paired up with improve comedians to romp through some amazing 16th-century astrological material. Perhaps most interesting was the German scholar who worried that the Great Comet of 1577 was going to cause plagues and famines. More terrifying for him, however, was the likelihood that the comet would produce more Frenchmen. The history of science is hilarious.