Thursday, October 27, 2022

4:30pm, Scheuer Room

Institutions and Idealism

In this paper I claim that institutions ought to foster an ethos of idealism among their members. Of course there is a sense in which most of us would prefer our colleagues and fellow citizens to display a refreshing optimism about the world rather than being weary cynics, but my claim is (hopefully) more specific than that. The basic thought is that very existence of institutions depends on people following their rules, yet those rules can never determine their own application. If an institution is to remain as the institution that it is, rather than changing into a different institution or simply decaying, its agents must therefore use their judgment to further its characteristic purposes. But to do that they need to ask themselves what those institutions are actually aiming at. That requires thinking about how an institution might best fit into the wider context of which it is a part, given its particular resources and capabilities as well its history and traditions. If this argument holds, then non-ideal, real-world institutions work best when represented by people who are idealists in a specific sense. This will be true of each and every agent and officer, not simply those at the top.

Thursday, November 9, 2022

4:30pm, Scheuer Room

Glass Stronger Than Steel: Experimental Investigations into the Physics of Glasses

Glasses take on many important roles, with applications ranging from rewriteable optical storage media and optical fibers, to high strength gorilla glass and metallic glass used in the screen and casings of smart phones. Connections between the physical properties of glasses and the underlying physics are heavily investigated, yet the nature of glass and the glass transition is “one of the deepest and most interesting unsolved problems in solid state theory [1].” This talk presents the work in my research group investigating the thermal properties of glasses- how they absorb heat from their surroundings- and the dynamics of glasses- how the absorption of heat controls the motions of atoms. I will introduce the strange world of glasses, present data we’ve collected in my lab here at Swarthmore and at the Spallation Neutron Source at Oak Ridge National Lab, and describe our findings in the context of addressing physics’ long-standing struggle to describe the true nature of a glass.  [1] Anderson, P. W. Science 267, 1615 (1995).

Thursday, February 16, 2023

4:30pm, Scheuer Room

New Perspectives on Neural Processing of Sound Source Location

One of the many functions of sound-responsive neurons in the brain is to create a sense of auditory space.  This can be useful for humans (when attempting to isolate a speaker's voice from a noisy background, for instance) and is essential for nocturnal or echolocating animals (those that rely on auditory cues to navigate their surroundings).  There is a "textbook" picture of parallel neural pathways that create auditory space: a low-frequency "channel" sensitive to timing-differences between the ears and a high-frequency "channel" sensitive to level-differences between the ears.  Emerging physiological evidence, however, is changing this long-held view.   I will discuss how I use mathematical modeling to study the specialized dynamics of neurons that create the sense of auditory space.  I will highlight new insights from this work including: how neurons can process microsecond-scale time differences at very high frequencies, and how neurons that process level-differences can extract timing information from brief sounds.  As I describe these specific projects, I will also offer some historical context regarding the rich history of mathematical modeling in neuroscience.

Thursday, March 23, 2023

4:30pm, Scheuer Room

Transmissions and Transgressions: The Voiced Body of Katherine of Alexandria in Medieval Devotions

Soon after the arrival of her putative relics in 11th-century Rouen, three distinct plainchant liturgies were composed in veneration of the apocryphal St Katherine of Alexandria. These musical repertories would become a vehicle of transmission for the cult of St Katherine, which soon became a transregional cultural phenomenon. By the turn of the fifteenth century, Katherine was arguably the second-most revered holy woman in Europe–after the Virgin Mary–a testament to the effectiveness of musical publicity. Various musical approaches to Katherine’s public theological disputation with the Roman Emperor and his all-star team of philosophers elicit questions about the meaning of women’s speech and subjectivity precisely at a moment of increasing surveillance and suppression. In this presentation, I interrogate how musical-liturgical representations of St Katherine were deployed for political, religious, and gendered purposes during the long twelfth century, arguing that any interpretation must consider an embodied Katherine, performed in song.

Student Speaker: Ava Pressmen '25