First of all, if the universe cannot collapse without a little mass, then it is absolutely impossible for the universe to be reborn, because it is impossible to expect all civilizations to return all the mass. Don't forget how the universe ends: civilizations pinch each other as soon as they meet, and murderous two-phase foil is thrown around. Now, if you ask these civilizations to spit out all the food they eat as soon as they are broadcast, it is very likely that all the individuals in the civilization will die. Do you think it's possible?
In fact, the three-body ending of Daliuyuan design is like this:
As soon as Guan Yifan and Cheng Xin returned to the big universe, they found that the big universe had changed beyond recognition. After analyzing the universe, Naoko told them that no civilization responded to the return movement. On the contrary, civilizations have intensified their efforts to seize mass and energy to carve up the big universe to supplement their own small universe. In order to seize more territory, they have used the laws of the universe to attack other civilizations at an unprecedented frequency-including using weapons that can directly reduce the three dimensions to 1. One-dimensional silk is vicious in that it can skillfully ensure that one-dimensional life can still survive, that is, to ensure that the other civilization is trapped in one-dimensional space forever, and life is worse than death. . . Naoko blew himself up when he finished all this, and then Notre Dame Cheng watched in amazement as Guan Yifan was pulled alive into silk by one dimension. Of course, Cheng himself of Notre Dame was not spared. The final result is that Guan Yifan and Cheng Shengmu are trapped in one-dimensional space forever, and what they see in one-dimensional space is a point representing each other. . .