Back to Article List The Real Reality Show: How Many Black Holes are in the Universe? While evidence for their existence is relatively new, black holes are showing up in huge numbers and in various sizes. By Astronomy Staff | Published: June 24, 2015 Get all the latest black hole news on Astronomy.com!
Cosmology, Exotic Objects, Science Ask Astro: Why do colliding supermassive black holes give off low-frequency gravitational waves?