Hello, dear reader!
The essay was written by two fourth-year students of the Chemical Technology course. We would like to touch on a topic that is not directly related to our training profile. The essay we wrote consists of about 90% "fiction" and only 10% "science". But after all, the rules of the competition did not specify how much percent is allocated to the "fantastic" and how much to the "scientific" part of the work? We decided to take advantage of this and talk about our assumptions and hopes, relying not so much on the existing laws of various sciences as on our own opinion. When writing the essay, we also turned to special literature so that our ideas would not contradict the existing facts too much.
Universe. How did she appear? What is it like? How old is she? People asked themselves similar questions many years ago and are still asking them. At the moment, scientists can answer most of them. Humanity is developing at a high speed (we want to believe in it), does not stop there, strives to find out what is far beyond our planet, tries to look into the most remote parts of the universe. It became possible not only to observe the processes taking place in the Universe almost from the moment of its origin, people were also able to go into outer space. Perhaps, in the very near future, a flight into space will resemble a school trip on an excursion. Therefore, in our essay, we would like to step outside the universe, hoping that its secrets will be solved in the coming years. 
The theory of parallel universes is quite common in the literature. For example, the notorious Stephen King has many books devoted to this topic; it is also worth mentioning Neil Gaiman, whose "Coraline" has received a number of prestigious awards. Let's not forget one of the pioneers, Michael Moorcock and his "Split Worlds".  Writers describe the ways of moving between universes in different ways, as well as the universes themselves. If earlier not so many people supported this idea, considering it a fantasy, fiction, now, we believe, more and more of those who are inclined to the existence of parallel universes, among these people include scientists. And some use the theory of parallel universes to explain the phenomena that we may encounter in everyday life. For example, it seems to us that many of you have at least once felt as if you had already done something before, but knew that this had not happened. Yes, we are talking about the so-called "deja vu". This phenomenon can be explained by a short transition to a parallel world. (Unfortunately, we could not find the original source of this assumption). As far as we know, at the moment it was not possible to confirm the theory, but they also could not prove its fallacy. As you might guess, we hold the position that the theory is correct, and we also hope that by 2100, or a little later, there will be evidence in favor of its correctness. 
If earlier confirmation of the theory of parallel universes was rather caused by the desire to achieve the truth, then every year the search for parallel universes and access to them become a necessity. First, our universe is continuously expanding, which leads to cooling. This means that after some time, although it is quite long, we will not be able to exist in it [1]. Secondly, the Sun, which belongs to the G-type main sequence stars, is short-lived. Life without the Sun will be hard to imagine. Thirdly, there is a possibility that our Galaxy, also not in a couple of years, of course, but will be "eaten" by the Andromeda nebula in a collision [1].
Where can I find a door that opens the entrance to parallel worlds? We believe that the Kerr black hole can serve as such a door [1]. This option seems to be the most likely, despite some disadvantages. We think we've already grabbed the handle of this door, but it's too scary for scientists to open it. There is a high probability that by 2100 people will thoroughly study this door, be able to look behind it, or perhaps take it off its hinges and carefully examine what is behind it. And then they will boldly step forward.    
The main question remains – what awaits us outside the door? What do parallel universes look like? Answering these questions, we will fantasize a little.
Parallel universes can be completely empty. We mean that there are no signs of life there. Perhaps there are no habitable conditions there, or maybe the basic laws that are the foundation of our universe do not apply there. Then it will be either impossible or very difficult for people to get used to such a world. We can continue to search for a suitable universe further. 
Let's consider another acceptable option. Another universe may be suitable for our existence from the point of view of our habitual living conditions, but it is quite possible that unfamiliar creatures live there, which are very different from us in appearance and behavior. This option may seem undesirable, because there is a possibility of danger caused by the creatures described above.  Of course, there is no complete certainty that these creatures pose any kind of threat. We will think positively and believe that unknown subjects are peaceful and ready to make friends. 
We can also assume that instead of very friendly unknown creatures other than us, there are people like us living in a parallel universe. This theory is also not ideal, since one cannot be sure that "other people" will not be hostile. Especially if their universe is much younger than ours and they are not yet ready to peacefully receive a large number of guests who have appeared, one might say, out of thin air. What if dinosaurs are still alive in this universe? They won't be too happy about the new arrivals either. Again, we prefer to be positive in this essay. Therefore, let's assume that in a parallel universe, "other people" are slightly ahead of our time and they may not just be ready to accept us, but also waiting. Then why don't they want to visit our universe themselves? It is quite logical that they do not have such an opportunity yet or are not even looking for it, since it is not necessary. We can also assume that they do not want to interfere in the life of an alien universe without important reasons. Or we just don't notice them. 
In fact, as you understand, there are many different supposed variants of parallel universes. Some, quite possibly, go beyond our understanding. The main thing is that scientists cannot with full confidence deny the existence of universes, which, for example, are proposed in our essay, even if they go beyond common sense, until facts appear that refute the possibility of such universes. We tried to choose the ones that look pretty convincing.
Would you like to travel through parallel universes? If so, what would you like to see in front of you – a "different person", a void, or a supermind, perhaps green in color with three eyes?