"Gravitational waves are fundamentally different. Not only is a gravitational wave a side-to-side, lateral wave like light, not a longitudinal wave like sound, but it isn’t a ripple through objects in spacetime; it passes through spacetime itself. When a gravitational wave passes by, spacetime squeezes and contracts. This oscillation influences matter, which exists in spacetime – but doesn’t require matter to be able to travel. It’s quite demeaning to gravitational waves to call their detection ‘hearing the sound of black holes in space’ as some have done. By comparison, sound is a trivial local effect. Gravitational waves make the universe itself vibrate."
- Brian Clegg (1955 - )
Gravitational Waves