(Image credit: NASA, ESA, and D. Coe, J. Anderson, and R. van der Marel (STScI))

Black holes are the most extreme objects in the universe. These hyper-dense celestial phenomena exert gravitational forces so powerful that not even light can escape their pull, and time itself is distorted in their orbit.

Physicist Karl Schwarzschild accidentally discovered the concept of black holes in 1916 while working on a solution to Einstein's general theory of relativity. However, at that point, black holes were still theoretical, and many scientists refused to believe they existed.

In 1930, Indian astrophysicist Subrahmanyan Chandrasekhar proved that they could exist by showing that above a certain density, no force can overcome gravity. It then took another 40 years for scientists to find one when, in 1972, astronomers Paul Murdin and Louise Webster surmised that a known galactic X-ray source called Cygnus X-1 was, in fact, a black hole.

Though we haven't known about these awe-inspiring objects for very long, our knowledge has come a long way in recent years. Has your black hole knowledge been keeping up?

Try as you might, you can't escape the pull of our black hole quiz, so it's time to find out how much you know about these cosmic drain holes. Be sure to login if you want to try for a spot on our leaderboard -- and feel free to hit the hint button if these perplexing objects leave you stumped.