时间的开始与结束
No stars . No planets . Not even any atoms . At the moment of its birth, the universe was emptiness. Then, in a burst of inflation—a bit like a balloon blowing up—a very tiny area grew much, much larger. This happened when the age of the universe was just “a trillionth of a trillionth of a trillionth of a second”, says Alexei Filippenko. He’s an astronomer at the University of California, Berkeley. The dramatic period is extremely brief. During inflation, the universe’s size doubled around at least 100 times.