The Epistemology of Gravitational-Wave Astrophysics

This dissertation provides a philosophical study of gravitational-wave astrophysics.This field was launched in 2015 by the first “direct detection” of gravitational waves and the first “direct observation” of a binary black hole merger by the LIGO-Virgo Collaboration. The dissertation includes three main chapters. The first provides an account of the sense in which the LIGO-Virgo detections of gravitational waves are“direct,” and examines the epistemic significance of the direct/indirect distinction thus given. The second concerns the use of gravitational waves to observe binary black hole mergers. I argue that a problematic circularity arises in this context due to the model-dependence of these observations. Finally, the third chapter considers the implications of multi-messenger observations (in this case, observations of the same event with both electromagnetic and gravitational radiation) for overcoming the epistemic challenges of astrophysics. Overall, this dissertation delves into the methodology and epistemology of this emerging field with an aim of understanding both the new resources it offers for learning about the universe and the epistemic challenges (new and old) that confront it in doing so.