Light, Liturgy, and Art at the Monastery of Saint John in Müstair, Switzerland: A Software Demonstration

In the early Middle Ages, solar observance shaped the art and architecture of Christian churches in various ways. Medieval writers from across the Mediterranean related dramatic lighting effects to alignment with the rising sun on astronomically and liturgically significant days. Medieval tradition about the Jewish temple in Jerusalem provided the model for these lighting effects as well as for the common use in early medieval churches of windows with jambs and sills that widen on the inside to expand the projection of natural light. Archaeoastronomers have hypothesized that select medieval pictorial programs were coordinated with fenestration to spotlight specific scenes and figures on specific days and at specific hours. We have created a 3D model that visualizes passage of sunlight on any particular day onto and across the walls of the monastery of Saint John in Müstair, Switzerland, the earliest standing church for which such coordination has been proposed. Our model tests and refines the theory of Gion Gieri Coray-Lauer, a Swiss archaeoastronomer.

The history of the region and other notable features of the church make Coray-Lauer’s hypothesis highly attractive. First, early medieval churches in the region were commonly aligned with still-standing prehistoric markers delineating astronomical lines or with the rising sun on a patron’s feast day. Second, the windows of the church have highly decorated jambs and sills, and they slant at various angles according to the direction that they face. Third, the feast days of the saints highlighted in the three apses of the church cluster around the summer solstice, when persistent pagan practices denounced by local preachers culminated each year.

Although situated in a remote alpine valley, the main church of the Monastery of Saint John preserves the most extensive program of church decoration in the west to survive from the first millennium. The program includes the earliest preserved monumental Last Judgment, east or west, among many precocious pictorial themes. The highly visible wall paintings display great clarity and exemplify the dictum of Pope Gregory the Great that pictures could serve as books for the illiterate. A greater understanding of the lighting effects deepens our understanding of the multi-sensory experience of medieval church decoration as well as our understanding of a medieval monument of great importance both for the extensiveness of its pictorial program and for the precocity of many images within it.

Scholars have well explored the symbolism of light in Christianity, both in text and image. Writers, both medieval and modern, have also written about the potential for light to move and dazzle the worshipper. Older scholarship on the quality of light in churches was based entirely on observation, but the methods and calculations of archaeoastronomy, which are generally incomprehensible to humanities scholars, have yet to penetrate the mainstream of art historical scholarship. The visualization of archaeoastronomical data within 3D virtual models enables art historians to judge more easily archaeoastronomical theories and to incorporate them into interpretations of how architects and designers of decorative programs structured and shaped religious experience.

We propose to demonstrate our software application in an interactive poster session.

References
iav.ipfw.edu/iu_home.html