A supermassive black hole is quite simply gravity gone mad. An object of such concentrated matter its gravitational pull is insatiable. Nothing can escape it, not even light itself. Anything that gets close- gas, stars and entire solar systems are sucked into oblivion. It even destroys the very fabric of the universe. If you think of the universe as a space-time web, the gravity of ordinary stars and planets creates a dent in this web. But the immense gravity of a supermassive black hole is so destructive that it distorts spacetime to breaking point.
At the heart of a supermassive black hole is one of the most mysterious things in physics-the singularity(奇點(diǎn)), a point where space, time and all known laws of physics fall apart.
What happens at the center of the singularity is a complete mystery. And solving it is going to require new physics that we just don't have right now. Some people think you can fall through the singularity and pop out in another part of the universe. The theories for the singularity are, some of them are very, very radical. We just don't know.
Supermassive black holes are so bizarre that until recently many scientists doubted they existed at all. They were an extreme idea dreamt up to explain a very rare and distant type of galaxy: active galaxies. These are amongst the brightest objects in the universe. These galaxies have a brilliant burning core with vast jets of energy spurting out of the center.
oblivion: destruction, extinction
space-time: the four-dimensional continuum in which all objects are located and all events occur, viewed as a single and continuous framework for existence. Space-time consists of length, width, depth, and time.
singularity: Astrophysics. A point in space-time at which gravitational forces cause matter to have infinite density and infinitesimal volume, and space and time to become infinitely distorted
an active galaxy is a galaxy where a significant fraction of the energy output is not emitted by the normal components of a galaxy: stars, dust and interstellar gas. This energy, depending on the active galaxy type, can be emitted across most of the electromagnetic spectrum, as infrared, radio waves, Ultra Violet, X-ray and gamma rays.