Black holes, but not as we know them

 作者:钟离窍钥     |      日期:2019-03-15 03:07:06
By JR Minkel THEY are the most fearsome objects in the universe. They swallow and destroy everything that crosses their path. Everyone knows that falling into a black hole spells doom. Or does it? In the past few years, cracks have started to appear in the conventional picture. Researchers on the quest for a more complete understanding of our universe are finding that black holes are not so black, and perhaps not holes either. Furious debates are raging over what black holes contain and even whether they deserve the name. The term “black hole” was coined in the 1960s by physicist John Wheeler to describe what happens when matter is piled into an infinitely dense point in space-time. When a star runs out of nuclear fuel, for example, the waste that remains collapses in on itself, fast and hard. The gravitational attraction of this matter can overwhelm its natural tendency to repel itself. If the star is big enough, the result will be a singularity. Around the singularity lies an event horizon, a point of no return. Light cannot escape once it passes beyond this boundary, and the eventual fate of everything within it is to be crushed into the singularity. But this picture always contained the seeds of its own destruction. In 1975 Stephen Hawking at the University of Cambridge calculated that black holes would slowly but inexorably evaporate. According to the laws of quantum mechanics,