SECRETS OF BLACK HOLES

PLACES WHERE THE LAWS OF PHYSICS ARE PUSHED TO THE EXTREME

- Giles Sparrow

Black holes are the most mysterious objects in the universe. They're places where physics is pushed to its most extreme, where light cannot escape and where space-time itself is twisted and even punctured, leading to the most incredible and counter-intuitive phenomena. A black hole is a region of space where gravity is so strong that nothing, not even light, can escape from its grasp. Within a certain proximity of one, closer than the black hole's 'event horizon', you'd have to travel faster than light to get away from it. Since nothing can go faster than light - at least as far as scientists know - then whatever falls down a black hole stays down the black hole.

The discovery of black holes dates back to Einstein's general theory of relativity. Einstein himself didn't predict the existence of black holes per se, but general relativity, which describes mass, space, time and gravity, provides the mathematical foundations for understanding them. These were realised by Einstein's German compatriot Karl Schwarzschild, who solved Einstein's equations to describe the gravitational field around a nonrotating, spherical mass and to determine the Schwarzschild radius, which is the size of a black hole's event horizon. In the 1960s, Roy Kerr solved Einstein's equations for a more realistic scenario that of a black hole that's spinning.