#multiple universes

#I often hear or read comments on the subject of multiple universes. Why have we come to this hypothesis and is it really proven? What does multiple universes mean?

In fact, the conclusion of multiple universes results from a proven scientific theory called "cosmic inflation." At first, how do we know that the universe started from an early event and that it hasn't been in its present shape ever since?

Several physical clues have brought scientists to the conclusion of the Big Bang. The most important of these is the fact that our universe is expanding rapidly. Galaxies far away from us are increasing. It's nice in science that finding the answer asks more questions, so I'm going to list the series of questions and answers that have brought us to conclude that there are multiple universes.

Expansion:
The world Hubble discovered that being full of galaxies and the earlier assumption that being a single galaxy is wrong. This new reality was a sense of curiosity to see how far these galaxies were from us, and when the galaxies were observed, it was discovered that the frequency of light coming from them brought us down to red. This discovery means that the light coming towards us from these galaxies is moving away from us because of the Doppler principle, which describes the mechanism of wave action in nature and how its frequency changes depending on the direction in which it proceeds. We all recognize the sound of the ambulance going through our side and how it's loud and sharp and then it goes down towards the direction of the car. This phenomenon that makes the sound of the ambulance gradually decline is the same one that makes the light of galaxies get us down to red because it's far from us.

If we discover that the universe consists of many galaxies and that these galaxies are moving in the opposite direction to us as a result of the expansion of space between us and those galaxies.

From here the idea of the Big Bang began to emerge, since if we go back in time, these galaxies must have been very close to each other until we reach a very small point.

Cosmic background radiation:
In research on the Big Bang, researchers launched an observatory to measure the radiation effects of the beginning and expansion of the universe, the result being what we call a map.
In other words, a map showing the radiation effect of nuclear reactions in the universe. This map shows how the universe is homogeneous throughout and cannot be distinguished anywhere in the map.

This result asked a very important and difficult question. Since the universe is expanding.