Fading Fringes, Failing Experiments

• In Event: When Infrastructures Fall Apart: Cuts and Ruptures in STS

Abstract

Cuts and ruptures play a central role in the epistemic practices of quantum physics. Karen Barad emphasizes the necessity of enacting a cut that separates the subject from the object and decides what is part of the measurement apparatus and what is part of the investigated object. Such cuts stop the evolution of the intra-action of observer and observed and produce the result of an experiment.
However, experimental setups seem to be broken pretty much all the time. Rhythms of building, aligning, maintaining and repairing the apparatus form a much larger part of laboratory work than actual measurements. In a rupture it is the fragility of the apparatus itself, that exhibits the multitude of agencies contributing to an observation.
Faults and failures limit the lifetime of experimental setups. I will present the case of a dying quantum physics experiment, the Kapitza-Dirac-Talbot-Lau interferometer for molecules of the Vienna QuantumNanoPhysics group. This interferometer currently holds the world record for the largest particles exhibiting quantum superposition. Its performance decreased significantly after ten years of operation, and the interference fringes began to fade. This triggered intense social conflicts within the group, driven by questions of power and differences in culture as well as experimental practice, but also influenced by external political pressure. Over a period of two years parts were exchanged and realigned, revealing the interdependence of the material practices and the status of the interference-pattern as artifact. Finally the interferometer was declared dead and bid farewell with funeral rites.

Authors

• Lukas Mairhofer, Institute of Physics, University of Vienna

• Anne Dippel, Friedrich Schiller University of Jena