The Body of Breath: Morphologies of Air Movement

Abstract

Iva Rešetar (IR): As we look back on our experiments with schlieren photography1, we can start this conversation by drawing connections between the role this technique had in the natural sciences and the ways we re-enact or ‘repurpose’ it in experimental design research. One can describe the schlieren apparatus as an optical set-up consisting of a parabolic mirror, a razor blade, a camera and a light – all placed in a precise configuration to expose differences in the refractivity of air. In this way, whatever transpires in front of the mirror will cause small changes in air density, temperature and pressure, creating the streaking effect of deflected light captured by the camera. This analogue manner of observing the temporal structure of air flows to “see the invisible”2 has made schlieren a tool for visualizing the complex behavior of fluid bodies, the patterns of their movement and expansion, and their interplay with solids. Tracing its sporadic deployment in science – from detailing candle plumes or plant respiration, to the high-speed physics of supersonic and ballistic experiments in the military-scientific context, it seems that for most of the time, without practical use and in the hands of many improvisers, it retained its character as a demonstrator – not necessarily for quantifying fluid dynamics processes, but as an ex perimental stage for performance and Léa Perraudin, Iva Rešetar & Clemens Winkler in Conversation