A newfound gravitational wave ‘hum’ may be from the universe’s biggest black holes
The timing of pulses from dead stars hints at ripples in spacetime that are light-years long
Dead stars called pulsars (illustrated) emit beams of radio waves that sweep past Earth like clockwork. Gravitational waves from supermassive black hole pairs (upper left) are thought to ripple the fabric of spacetime and alter the pulsars’ timing.
Aurore Simonnet/Sonoma State University, NANOGrav