"Scientists say they are starting to find signs of an elusive type of rumbling through space that could be created by the biggest, baddest black holes in the universe.
The discovery means that astrophysicists may have opened a whole new window onto supermassive black holes. These mysterious, extremely dense objects, millions to billions of times more massive than the sun, sit at the center of galaxies like our own."
Read the full NPR article.
