Everything that can be imagined exists. Otherwise it cannot be imagined. The idea of the world is in the brain, in representations. The many-worlds interpretation, or the Everett interpretation, is an interpretation of quantum mechanics that assumes the existence (in a sense) of "parallel universes", in each of which the same laws of nature operate and which are characterized by the same world constants in different states.
The scientific community does not need to be told about the scientific background of the theory of multiple worlds. It is for the average person such things are perceived as fantasy, because not everyone knows that there is a scientific justification for the existence of parallel worlds. There are several explanations, among which are the Copenhagen interpretation, Everett's many-worlds interpretation and other similar ones. The bottom line is that the scientific community is studying this issue, so you should not take it lightly. It is better to try to understand how it is possible, how such a thing can be realized.
Many people will be surprised, but a large number of people who adhere to the scientific basis of the universe are convinced that these parallel worlds do exist, moreover – they are an exact copy of ours. As proof, I will give you quantum teleportation. Since not everyone, to whom I present my idea, understands subtleties of justifications, – I will give detailed explanations.
Let's start with scientific substantiation of cloning methods, digitalization of memory and existence of other civilizations that exactly repeat our world. For example, everyone knows about animal cloning and the methodology of fast growing, for example, broiler chickens. In this way, by slightly transforming the technology, it is possible to make human clones. A human can be "created" within a year. The next stage is loading consciousness into him. It seems incredible, but it's much simpler than that. This is achieved by recording the brain radiation, and then converting this radiation into a form that affects the chemical reactions in the brain. You say how? Now let's see what we already have of this.
There is such a topic – about "invisible radiations" constantly emitted by living matter. This is ultra-weak ultraviolet radiation, not only emitted by all cells, but also stimulating their division. Its nature is so mysterious that it has been forgotten because of its obscurity. We will not dwell on it in detail, as I have misspoke, – scientific to scientific. I will only say that already with the help of tomography, using the method of comparison, we study changes in the brain during these or those thought processes. In fact, we study an incomprehensible "foreign language" with the help of examples, comparisons and comparisons. What is important is that having recorded one state, it is possible to force a reverse process, although in nature, in our life, this happens all the time. That is, we live this way. The main thing for us is that in this way one brain state is transferred to another. After all, you are not surprised when your thoughts, transformed by you into words (and scientifically – into sound waves), get to the ear, from there to the brain, and there already cause the necessary reactions. You can read about the existence of brain waves, their transmission to devices on the network. For example, you can use your thoughts to type what you are reading. Not with words, but with thoughts. All of this is already real.
Now the question is: do other worlds exist? This can be answered in terms of both religion and science. It's a win-win to convince you. Surely you either believe in God or science, and most people believe in both in different interpretations. So, let's take an example from the Bible, and in almost all known religions there is a mention of other worlds: "And the other inhabitants of the universe have not fallen". And the scientific example is based on probability and imagination about infinity. Here you are, can you imagine infinity, for example, of time and space? Whatever magnitude you imagine – there must be something beyond it. From this follows a logical conclusion: there is everything in infinity. And if you have doubts now, it means that you have imagined the smallest part of this infinity.