This topic has been under controversy for a long duration of time but before digging deep into it, let us know some facts about it and what is it actually.
Well the theory originated from a term called multiverse and it came to light after it was highlighted in the sci-fi movies. So what is actually Multiverse:
Around 13.7 billion years ago, simply speaking, everything we know of in the cosmos was an infinitesimal singularity. Then, according to the Big Bang theory, some unknown trigger caused it to expand and inflate in three-dimensional space. As the immense energy of this initial expansion cooled, the light began to shine through. Eventually, the small particles began to form into the larger pieces of matter we know today, such as galaxies, stars, and planets.
One big question with this theory is: are we the only universe out there? With our current technology, we are limited to observations within this universe because the universe is curved and we are inside the fishbowl, unable to see the outside of it (if there is an outside.)
There are at least five theories why a multiverse is possible, as a 2012 Space.com article explained:
1. Infinite universes. We don't know what the shape of space-time is exactly. One prominent theory is that it is flat and goes on forever. This would present the possibility of many universes being out there. But with that topic in mind, it's possible that universes can start repeating themselves. That's because particles can only be put together in so many ways. More about that in a moment.
2. Bubble universes. Another theory for multiple universes comes from "eternal inflation." Based on research from Tufts University cosmologist Alexander Vilenkin, when looking at space-time as a whole, some areas of space stop inflating like the Big Bang inflated our own universe. Others, however, will keep getting larger. So if we picture our own universe as a bubble, it is sitting in a network of bubble universes of space. What's interesting about this theory is the other universes could have very different laws of physics than our own, since they are not linked.
3. Daughter universes. Or perhaps multiple universes can follow the theory of quantum mechanics (how subatomic particles behave), as part of the "daughter universe" theory. If you follow the laws of probability, it suggests that for every outcome that could come from one of your decisions, there would be a range of universes — each of which saw one outcome come to be. So in one universe, you took that job to China. In another, perhaps you were on your way and your plane landed somewhere different, and you decided to stay. And so on.
4. Mathematical universes. Another possible avenue is exploring mathematical universes, which, simply put, explain that the structure of mathematics may change depending in which universe you reside. "A mathematical structure is something that you can describe in a way that's completely independent of human baggage," said theory-proposer Max Tegmark of the Massachusetts Institute of Technology, as quoted in the 2012 article. "I really believe that there is this universe out there that can exist independently of me that would continue to exist even if there were no humans."
5. Parallel universes. And last but not least as the idea of parallel universes. Going back to the idea that space-time is flat, the number of possible particle configurations in multiple universes would be limited to 10^10^122 distinct possibilities, to be exact. So, with an infinite number of cosmic patches, the particle arrangements within them must repeat — infinitely many times over. This means there are infinitely many "parallel universes": cosmic patches exactly the same as ours (containing someone exactly like you), as well as patches that differ by just one particle's position, patches that differ by two particles' positions, and so on down to patches that are totally different from ours.
After knowing some details about the multiverse , now let us explore the parallel universe;
So before starting it again the basic question arises: What is Parallel Universe?
Until now it was just an introduction, now let me tell you what does NASA have to say about it:
According to the New York Post, Nasa Scientists have detected some evidence of a parallel universe, so what are they?
According to the Scientists, Low-energy, subatomic neutrinos with a mass close to zero can pass completely through Earth, but higher-energy objects are stopped by the solid matter of our planet, according to the report.
That means the high-energy particles can only be detected coming “down” from space, but the team’s ANITA detected heavier particles, so-called tau neutrinos, which come “up” out of the Earth.
The finding implies that these particles are actually traveling backward in time, suggesting evidence of a parallel universe, according to the Daily Star.
Now finally let me give you some evidence that shows the existence of the parallel universe (or maybe they are just hoaxed depends on you):
1. Mysterious Ripples In Space-Time May Offer Proof Of Parallel Universes
Finding evidence of parallel universes is very challenging. Scientists have hoped that the Large Hadron Collider (LHC) might reveal evidence of their existence, but so far definitive proof has not been discovered with the LHC. Physicists have studied gravitational waves, ripples in space-time caused by the motion of massive objects and now they suggest these waves might allow for a single, coherent theory of the universe. Basically, this means that signs of extra dimensions may reveal themselves in the way they impact gravitational waves.
If there are extra dimensions in the universe, then gravitational waves can walk along any dimension, even the extra dimensions. This suggests parallel universes can exist.
2. Black Holes Could Be Gateways To Parallel Universes
The idea that black holes could be gateways to parallel universes has been a popular science fiction topic for long, but is it scientifically possible?
According to Stephen Hawking, renowned theoretical physicist and cosmologist, mysterious, destructive, dark parts of the universe could answer one of the most puzzling paradoxes of physics – the existence of parallel universes.
Stephen Hawking has argued in favor of parallel universe theory for many years. It has previously been assumed that anything that falls into a black hole would be destroyed and lost forever, but Hawking is of a different opinion.
Hawking suggests the black holes are not as black as previously thought. In his opinion it is highly possible that something falls through black holes, without being destroyed and entering a parallel universe.
To explain how information can escape from a black hole is a challenge. Stephen Hawking calculated that black holes eventually must end. According to his calculations, the black holes eventually begin to leak information and eventually explode, which would release the trapped particles in any form. “That way out wouldn’t take people back to where they’d come from, he said. Instead, they would reappear, but somewhere else – perhaps even in an alternative universe.
3. A ‘Mirror World’ Could Be Hiding Behind Dark Matter
Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but would account for most of the matter in the universe.
The possibility that there could be a mirror world hiding behind dark matter would rewrite our understanding of the Universe.
Dark matter is one of the great mysteries of the universe. No one knows what it consists of and no one has seen it, because it doesn’t interact with the matter scientists know about.
Many scientific labs are trying to detect dark matter since the Earth is moving in a cosmic wind of the dark matter. Final identification of what makes up the enigmatic dark matter would open up whole new areas of research including the possibility of multiple universes and other dimensions, physicists say.
4. South Atlantic Anomaly – Could Black Holes On Earth Be Portals To Parallel Universes?
Vortices on our planet are similar to black holes. Scientists have discovered that each vortex boundary in a turbulent fluid contains a singularity, just like an astrophysical black hole.
The South Atlantic Anomaly (SAA) refers to the area where the Earth’s inner Van Allen radiation belt comes closest to the Earth’s surface. This leads to an increased flux of energetic particles in this region and exposes orbiting satellites to higher than usual levels of radiation. The effect is caused by the non-concentricity of the Earth and its magnetic dipole, and the SAA is the near-Earth region where the Earth’s magnetic field is weakest.
An intriguing possibility is that such remarkable vortices could be gateways to parallel worlds or other dimensions.
5. Mystery Of The Mandela Effect: Are ‘False Memories’ Proof Of Parallel Universes?
A controversial and intriguing theory suggests that ‘false memories’ could be proof of parallel universes.
Scientists are naturally divided on this topic and most think false memories are a result of how we misremember things. Yet, perhaps there is more to it than we are aware of. It has been suggested that people are sliding between multiple universes and that’s how we can create very odd memories of something we have never seen or heard in this world.
Basically, the Mandela Effect refers to a phenomenon in which a large number of people share false memories of past events, referred to as confabulation in psychiatry. Some have speculated that the memories are caused by parallel universes spilling into our own, while others explain the phenomenon as a failure of collective memory.
6. Can Parallel Universes Explain The Déjà Vu Phenomenon?
Another intriguing possibility is that there is a hidden connection between déjà vu and the existence of parallel universes.
Have you ever had a déjà vu experience? It’s the feeling, or impression that you have already witnessed or experienced a current situation.
The term déjà vu is French and means, literally, “already seen.”
It is a rather common, yet little-understood phenomenon. Most of us have experienced being in a new place and feeling certain that we have been there before, but we have difficulties understanding how it is possible.
In recent years, as more scientists began studying this phenomenon, a number of theories about déjà vu have emerged, suggesting that it is not merely a glitch in our brain’s memory system.
Psychologists have suggested that déjà vu may occur when specific aspects of a current situation resemble certain aspects of previously occurring situations.
If there is a lot of overlap between the elements of the new and old situations, we get a strong feeling of familiarity.
Alternative explanations associate déjà vu with prophecy, past life memories, clairvoyance, or a mystic signpost indicating fulfillment of a predetermined condition on the journey of life.
Whatever the explanation, déjà vu is certainly a phenomenon that is universal to the human condition, and its fundamental cause is still a mystery.
Another intriguing possibility is that there is a hidden connection between déjà vu and the existence of parallel universes. According to Dr. Kaku, quantum physics states that there is the possibility that déjà vu might be caused by your ability to “flip between different universes”.
Dr. Kaku mentions Professor Steve Weinberg, the famous theoretical physicist and Nobel Prize winner, supports the idea of a multiverse.
Weinberg says that there is an infinite number of parallel realities coexisting with us in the same room.
7. Are Some Of Our Dreams Glimpses From A Parallel Universe?
In this world there could be a copy of yourself making different decisions and seeing places that somehow later manifest themselves in your dreams.
For thousands of years people have wondered about the meaning of dreams. Why do some people dream about future events? Why are some dreams full of hidden meaning?
Can some of our dreams be glimpses of events taking place in an alternate reality, a parallel Universe?
For almost a hundred years science has been haunted by a dark secret: that there might be mysterious hidden worlds beyond our human senses.
Mystics had long claimed there were such places. They were, they said, full of ghosts and spirits. The last thing science wanted was to be associated with such superstition, but ever since the 1920s physicists have been trying to make sense of an uncomfortable discovery. When they tried to pinpoint the exact location of atomic particles like electrons they found it was utterly impossible. They had no single location and this is one of the reasons why scientists are becoming more and more interested in the possible existence of parallel worlds.
The only explanation which anyone could come up with is that the particles don’t just exist in our Universe. They flit into existence in other universes, too and there is an infinite number of these parallel universes, all of them slightly different.
8. Stories About People Who Entered A Parallel Universe
There are many strange stories about people who vanished into thin air never to be seen again. Did these people enter a parallel world? For example, many years ago, El Tiempo, one of the largest newspapers in Venezuela reported about a very strange and unexplained disappearance of a Professor who simply vanished in front of many people. He was never seen again.
So finally according to me till we don’t find any apt proof it is being real, the theory of parallel universes will remain a theory and after all it depends on us how much we believe in it. I am neither in support of this theory nor against it, according to me until we get Armstrong proof it will remain a hoax for me.