In August 2025, the global network of gravitational-wave observatories operated by the LIGO-Virgo-KAGRA (LVK) Collaboration released a huge new logbook of cosmic collisions – its fourth Gravitational-Wave Transient Catalog (GWTC-4.0) [1-6]. These gravitational waves, or ripples in spacetime, are created when the most extreme objects in the Universe, black holes and neutron stars, crash into…