ESHS/HSS Annual Meeting

Cultural Anthropology and the geometry of gnomonic projections from ancient times to present days

• In Event: Representing the Sky from the Earth and Vice Versa: Gnomonic, Archeoastronomy, Cartography and Geometry

English Abstract

Humanity has always based its relationship with space and time on the continuous change of sunlight. Light controls the processes of biological life, and even certain human hormonal activities depend on it; consequently, even primitive humans had an awareness, albeit not a scientific one, of temporal phenomena. But the ambition of ancient populations was to understand, control, predict, and thus participate in temporal processes that went beyond the brief interval of individual life.
Thanks to gnomonics, the ancients were able to calculate and represent (and thus control through the prediction of the phenomenon's cyclicality) the complex movements of the Sun, which were otherwise intangible and remote. With the advent of optical and mechanical instruments, and later digital ones, time measurement became independent of gnomonics, which had the limitation of marking the time of a single location, as it was strictly dependent on latitude.
Gnomonics is today considered an outdated discipline belonging to ancient civilizations and artifacts, resulting in many sundials being abandoned to decay, despite being precious testimonies of art, history of science, and especially cultural anthropology. Although no longer useful for timekeeping, the science of gnomonics continues, however, to provide those inescapable geometric relationships between sunlight and cast shadows to predict the latter's shape and size.
The geometry of light and shadow from ancient gnomonics has been adopted today by some architects and artists whose works use the same geometric models of the past for time measurement, but not for chronometric purposes. These works, of high geometric and symbolic value, show us the potential of art and architecture to facilitate our ability to observe and understand the world—be it terrestrial or cosmic, human or deified—as well as highlighting our role within them.

Author

• Alessandra Pagliano, University Federico II of Naples