Glassworks

TRANSPARENCY—OPACITY—REFLECTION

February 7-8, 2020

glassworks.princeton.edu

The Program in History of Science Annual Workshop
Princeton University

Workshop organized by Daniel Jütte, Katja Guenther, and Jennifer Rampling

Glass is an invisible, indispensable agent in scientific work. It is the material we see through, or which reflects back faithfully. It is the source of rich, metaphorical language: whether opening a window on the world or engaging in self-reflection. In this workshop we explore both the material and conceptual worlds of glass, using as our lens the interlinked properties of transparency, opacity, and reflection.

Transparency is the property most commonly associated with glass. Many of the scientific uses of glass —whether as container, experimental space, or optical tool— relate to this state of vitreous perviousness. However, the transparency of scientific objects is more than just a practical convenience; it has also come to signal precision, accountability, and “good practice.” How did vitreous transparency acquire this powerful symbolic meaning? And how, in turn, does the notion of “good transparency” inform the (popular) image of modern science and its practitioners?

Historically, of course, glass was not always clear; and when made clear, it did not always stay that way. In fact, throughout the past, opacity had no shortage of practical applications, as products and technologies evolved to exploit the differing grades of translucency made possible by the vitreous medium. Makers of artificial gems and colored glass sought to imbue their materials with opacity, sometimes in order to more accurately imitate nature. In early photographs and magic lanterns, the transparency of the medium was deliberately interrupted in order to create both permanent and ephemeral images.

The more glass becomes opaque, the better it is able to reflect: a technique fundamental to modern mirror-making, where reflective surfaces are constructed by combining a transparent pane of glass with an opaque metal substance. The same technique made mirrors central experimental tools in the history of the post-war human sciences, most notably in the form of the self-recognition test. Yet not every mirror is glass. The mirrors of antiquity were made from polished metals, and this affected the visual experience of the reflected image. The introduction of glass in mirror-making added complexities to their use that have had important historical ramifications —for instance, in early telescopes, which exploited both the reflecting and the refracting properties of glass. In interrogating such complexities, we seek to render visible the manifold ways in which glass has contributed to the production of knowledge —in short, how glass works.