Biography:

Stephen Fairhurst is a Professor of Physics and Astronomy at Cardiff University. After earning a BA and Part III in Mathematics from Cambridge and a PhD in Physics from Penn State in 2001, he held postdoctoral positions in Canada and the U.S. before joining Cardiff in 2007 as a Royal Society University Research Fellow. His research focuses on gravitational-wave detection and astrophysics, contributing to landmark discoveries such as GW150914 and GW170817. In 2025 he became the first non-U.S. spokesperson for the LIGO Scientific Collaboration.

Abstract:

Just over ten years ago, the first gravitational-wave signal, emitted during the merger of two black holes, was observed.  Since then, we have observed four hundred gravitational wave signals.  I will present the most recent observations, presented in the fourth gravitational-wave transient catalog (GWTC-4), including several exceptional events.  I will also discuss how gravitational-wave observations help us understand the nature of black holes and how they form in the Universe.