It is generally accepted that the Universe arose as a result of the Big Bang about 13.8 billion years ago. However, some researchers believe that this hypothetical event was not one of a kind. It is possible that many such "explosions" have occurred before. The result of such revolutionary leaps could be the formation of many universes, different from the one in which humanity happened to live.
How many universes are there?
Three decades ago, the so-called theory of inflation began to spread in the scientific world. At the center of this concept is the idea of a special form of matter, called "false vacuum". It has very high energy characteristics and high negative pressure. The most amazing property of false vacuum is repulsive gravity. The space filled with such a vacuum can quickly expand in different directions.
Spontaneously arising "bubbles" of vacuum propagate at the speed of light, but practically do not collide with each other, because the space between such formations expands at the same speed. It is assumed that humanity lives in one of many such "bubbles" that are perceived as an expanding universe.
From an ordinary point of view, multiple “bubbles” of false vacuum are a series of other, completely self-sufficient universes. The catch is that there are no direct material connections between these hypothetical entities. Therefore, alas, it will not work to move from one universe to another.
Scientists conclude that the number of universes that look like "bubbles" can be infinite, and each of them expands without any restrictions. In universes that never intersect with the one where the solar system is located, an infinite number of options for the development of events are formed. Who knows, maybe in one of these "bubbles" the history of the Earth is exactly repeated?
Parallel universes: hypotheses need confirmation
It is possible, however, that other universes, which can be conditionally called parallel, are based on completely different physical principles. Even the set of fundamental constants in the “bubbles” may differ significantly from that provided for in the native Universe of mankind.
It is quite possible that life, if it is a natural result of the development of any matter, in a parallel universe can be built on principles incredible for earthlings. What then can there be Intelligence in neighboring universes? So far, only science fiction writers can judge about this.
It is not possible to directly verify the hypothesis of the existence of another universe or even a set of such worlds. Researchers are working on collecting "circumstantial evidence", looking for workarounds to confirm scientific assumptions. So far, scientists have only more or less convincing guesses based on the results of studying the relic radiation, which sheds light on the history of the origin of the Universe.