Black Hole
An astronomical object whose gravity is so strong that not even light can escape. Nothing that happens inside its boundary, the event horizon, can be communicated to the outside.
The supermassive black hole in the Perseus galaxy cluster sends sound waves through surrounding hot gas. Each oscillation takes about ten million years, far below human hearing. In 2022, NASA pitched it up about 57 octaves and released it as the viral 'sound of the universe.'
0