Natural History Wanderings

The New York Times reports

In space you can’t hear a black hole scream, but apparently you can hear it sing.

In 2003 astrophysicists working with NASA’s orbiting Chandra X-ray Observatory detected a pattern of ripples in the X-ray glow of a giant cluster of galaxies in the constellation Perseus. They were pressure waves — that is to say, sound waves — 30,000 light-years across and radiating outward through the thin, ultrahot gas that suffuses galaxy clusters. They were caused by periodic explosions from a supermassive black hole at the center of the cluster, which is 250 million light-years away and contains thousands of galaxies.

Read more at Hear the Weird Sounds of a Black Hole Singing – The New York Times