236 merging black holes weigh in on the Hubble tension

Using 236 gravitational-wave events from GWTC-5.0, the LVK collaboration measures the Hubble constant at 71.0 (+9.0/−7.1) km/s/Mpc — splitting the difference between the two conflicting standard methods, though still too uncertain to resolve the tension. The improvement comes from combining black-hole mass-spectrum features, galaxy catalog cross-matching, and the single binary neutron star with a light signal (GW170817). Crucially, the waves themselves show no deviation from general relativity across cosmic distances.