What are black holes? Everything you need to know about the darkest objects in the universe
Black holes are regions of space where the gravitational pull is so strong that nothing — not even light — can escape. Rather than empty space, black holes are chock full of matter that gets squeezed into a teensy space. Who discovered black holes? Physicist Karl Schwarzschild accidentally discovered black holes in 1916, when he was figuring out a particular solution to Einstein's general theory of relativity. He was trying to find the solution to the gravitational pull of a single, solitary, symmetric ball of matter — such as the sun at the center of our solar system. But that solution contained a peculiar feature: the theory behaved strangely at a specific radius, known today as the Schwarzschild radius. It was later realized why this radius was so special. If you compressed the mass of an object into a space smaller than that radius, its gravitational pull would overwhelm every known force and nothing could escape. Early physicists assumed that this situ...