If we run the movie of our universe backwards, we know that there was a Big Bang in our past, and we might even hear the cacophonous sound of it, but was our Big Bang the only Big Bang?
如果我们倒着播放宇宙的历程， 我们可以知道过去曾有过一次大爆炸， 我们甚至可以听到它那吵杂的声音， 但我们的大爆炸是宇宙中唯一的大爆炸吗？