The concept of parallel universe is an idea that arises from the multiverse theory, suggesting that our universe is one of many existing universes.Parallel universe is a hypothetical self-contain reality co-existing with one’s own. A specific group of parallel universe called a multiverse. According to Stephen Hawkins there is another universe similar to us and have their own galaxies,blackhole and well settled civilization. According to this , the way the Earth had created similarly there was creation of other universes. Many socials also agreed Stephen Hawkins that these had created on the same way the earth had created.
Theories
1) Multiverse
According to this theory there are several universes. Scientist stated that there are infinite universes, stars, planets, galaxies and there can be planet similar planet similar to earth. If there are infinite universes so after a limit there is a possibility of repetition of things. As a result there can be people who look alike you. Parallel universe assumes space is infinite (it very well could be) and the physical laws of these other universes are the same as ours, but are so far away from us that we causally got disconnect, meaning that no messages can received or sent because we can only receive messages from within our own Hubble volume.
2) Quantum Theory of Multiverse
It says that when the multiple possibilities are involve, every new possibility give arise to a new possibility. We can understand this concept with an example like: According to Big bang theory the Earth had created 4.5 billion years ago, and if theia had crashed to mars instead of Earth then mars was stable. As a result earth was barren and at the same time the mars was full of colourful people due to butterfly effect. There was no existence of earth.

3) Mirror Universe Theory
According to this theory when Big bang happened, then our universe got expand in one direction and a mirror universe had created in the opposite direction. It looks like similar to our universe but matter and anti-matter came out as a difference between them. It also says that time increase in forward direction. As a result when this mirror universe expand it directly reached to its future.Ultimately having behind just one universe is our universe.
4) Cosmic Inflation Theory
It says when big bang has happen 13.8 billion years ago then gravitational and strong nuclear force separated after that the weak electric force could not hold the universe tightly. As a result, our universe got expanded between 1036 to 10³² this is known as Inflationary Epoch. According to some cosmologist if some universes Inflationary Epoch had finished before 10³² then their Earth had formed before us. As a result their earth had been shifted towards the sun habitable Goldilock zone due to which their earth would be had been warn and where carbon based life would be warn. So due to evolution instead of carbon their silicon based life had formed. This is because…
- Silicon can formed chains like carbon.
- Silicon is more stable at high temperature.
Hence there is a possibility that people living there consumes energy from sun.
Read More- Layers of Atmosphere
Evidences
1) John Titor
A man named John Titor claims that he was from 2036. He told that he had travelled back to 1975 to bring IBM 5100 computer and while going back in 2036 he had stayed in 2000. On asking proofs he uploaded the photo of time machine which design looks like real. On giving further proofs he told that we should stop space shuttle over heat problem, and at 2003 Colombia space craft crashed due to overheating. He also told many other prediction and but some were correct and some not. But suddenly he disappears in 2001.

2) A Man from Taured
In 1954 a plane landed in Japan airport, where a man looking like a businessman came out of the airport. When his passport got checked everybody get shocked. The passport was of Taured country of Europe, but the Taured country had never exist. On investigation he located his country on the map of Europe. Further checking his license it was found that his country was Taured. Everybody was confuse then they put him in the room. Next morning he suddenly disappears with all his official documents.
3) College Girls Disappears
Maria, Crystal, Jonny and Abey… together took a day trip to Nevada, to see the radeo in pioche. It was night time when they returned on highway 56, But while returning they got confuse because all the roads looked same. They all agreed to move towards Gadianton Canyon. On going further the roads changed from black to white concrete. They reached at the end of the Highway where there was Dead End, so they decided to drove back. While going back they saw that the place had changed. Instead of desert they saw fields of Wheat. They had lost. On moving ahead on road they saw glow of civilization. They saw a neon sign which was not in English. Further they saw group of men coming out of the restaurant. Crystal screamed that those are not humans, Then jonny pull her car back and started moving. They saw that an egg shaped vehicle which was not from earth, following them. Jonny drove the car very fast and they secede to came out from there.
Read More- Facts About Earth