LZ. Please bear with me and read my thoughts. After all, this is a question that can only be speculated on. It can only be speculated using philosophical and mathematical methods. We observe the following facts about the universe: 1. Seen from the earth. All stars in the universe are moving away from us, and the speed is proportional to the distance. 2. Quantum theory and relativity seem to be incompatible, but if string theory is used as the theoretical basis, these two centuries of theory appear to be in perfect harmony. 3. Philosophically speaking, the universe must evolve into what it is now before we can exist (people follow the principles of the universe and deduce causes from the results) 4. The direction between space and time is consistent (our universe continues to expand, and we The defined time direction is the direction of space (the direction of the universe is forward). From the above points, we can imagine that our universe is currently like a hydrogen balloon. One of the points where we are on a hydrogen balloon. The balloon keeps inflating. It keeps getting bigger. When we are at one point of this balloon, we will have a scene similar to how we look at other planets from the earth - all the points on this balloon are moving away from us) However, we can still find this balloon on this balloon Isn’t there a central point when there was no mine? Because the center point of this balloon mine when it was big is no longer where we are. (LZ Just imagine that the center point of the balloon is at the center of the balloon (provided that you observe the balloon from outside the balloon) but we are on the edge of the expansion of the balloon. We will never find the center point of the balloon... This LZ, you must understand string theory, which means that string theory describes the universe as having eleven dimensions! (Time is one dimension and space is ten dimensions.) The theory of relativity and quantum theory are perfectly combined under the geometric mathematics of ten dimensions! According to this statement, the center point of our universe does not actually exist in the three-dimensional world! ! You can imagine that countless points constitute lines, countless surfaces constitute a body, and the universe is actually a The n(n>3)-dimensional body (if the universe can be seen from outside the universe) is like the earth. If we have no other reference and no modern technology, we will never be able to get out of the earth. So I think, even if the universe stops. Expansion, if you start from the earth and keep walking, you will eventually go back to the earth, because for us, space belongs to the universe. "Objects" like us can only exist in space (of course, if there is a universe. It cannot be said that there is no space outside, I just assume) just like we are on the earth. Because we belong to the space inside the earth, it is really difficult to describe your problem without the help of other technologies. This question can be imaginative... But my overall point is that there is "space" outside the universe (I don't know whether it is the "space" of our universe). If we Earthlings haven't been able to fly yet, If we go out of space, can we all think that space is only a unique property of the earth? It turns out that the universe has space. So we cannot say that time and space can only be equal to our universe. Maybe there is space and time outside the universe. But I agree that there are universes outside the universe, because maybe the "universe" we currently think of is just one of the many "universes" that we can't observe. Our universe is the same. Each one expands in an unimaginably large space. When everyone comes into contact, a large fusion of matter can occur (Imagine the ripples on the lake surface colliding). When the mass of matter fusion reaches a certain critical point. When the so-called Big Bang happens again, the "second generation" universe will be born again! Please accept my answer! It is definitely the most thoughtful answer to your question. ! (Summary: Singularity either doesn’t exist.

Either depends on where the two universes meet)