Constructing Stillness: Theorization, Discovery, Interrogation, and Negotiation of the Expanded Laboratory of the Laser Interferometer Gravitational-Wave Observatory

Abstract

What if someone asked you to keep a four-kilometer-long ruler absolutely still so that you could measure deformations of length of ~1x10^-18m using light? On September 14, 2015, physicists and engineers at the Laser Interferometer Gravitational-Wave Observatory (LIGO) accomplished this absurd feat when they first detected gravitational wave signals—the result of the most violent events in our universe, such as the collision of two black holes—using two immense L-shaped instruments with arms four-kilometers in length and placed in what seemed to be the middle of nowhere.

The focus of this dissertation centers on how scientists must have an intricate understanding of the environment surrounding LIGO’s instruments to understand the vast and active universe through the detection of gravitational waves. I explore how LIGO physicists and engineers constructed stillness to distinguish the surrounding natural and built environment from gravitational wave signals. I explore how the pre-LIGO and LIGO laboratory spaces became an expanded laboratory extending as an overlay into the surrounding environment and beyond. I show that the metes and bounds of the expanded laboratory are defined by what the interferometers are sensitive to. I further explore how physicists, engineers, and data scientists theorized an experiment that required such an extreme sensitivity (i.e., imagining stillness), developed methods to investigate, understand, and abate noise, disturbances, and aberrations (i.e., engineering stillness), found sites with minimal noise profiles, both physical and social, that would accommodate the size and function of the instruments despite land uses in conflict with the experiment (i.e., finding stillness), and understood the overlapping human and non-human uses of the land that jeopardized the ability to make these highly precise detections and mediate solutions that would allow for concurrent use of the land (i.e., negotiating stillness).

Through this history, I conclude that the level of sensitivity the physicists and engineers can attain in the LIGO interferometers is predicated on constructed stillness. This determines the instruments’ ability to measure the minute deformations in length caused by gravitational waves such that the physicists, engineers, and data scientists can rule out the geography of noise and make the claim that the heterogeneity of their locations at Hanford and Livingston does not negate their assertion of twin detections of gravitational wave signals across their two sites.