With past years our understanding of science and the universe has expanded exponentially giving us a complete new outlook towards the cosmos opening up a very controversial idea yet an intriguing one: do parallel universes exist?
People might say “that's a completely philosophical bullshit having no solid proof” but as science and our understanding of the universe is escalating we have, with all interest and purpose started taking this idea critically and realized that the probability of this simple idea being actually true is quite high. Many popular and widely successful theories like the quantum entanglement and the theory of expansion of the universe has led many of the scientists to strongly believe that our universe is not alone!
Before understanding and exploring the concept of parallel universes let's first understand how everything we know of came into existence. About thirteen billion years ago when an extremely dense matter exploded, it created galaxies, stars, planets, humans and perhaps universes.
This universe is entirely crafted out of atoms linked together, forming matter and anyone with basic knowledge of atoms would be aware of the fact that atoms are further made out of three subatomic particles. Protons ,which have a positive charge, along with neutrons (neutral charge), form the nucleus and around them electrons ,having a negative charge, revolve at a great speed which is also called as quantum spin. Everything in this universe is made out of millions of atoms bonded in complex structures giving the matter, the unique properties it possesses.
We all are taught at schools and universities that electrons and protons have negative and positive charge, receptively but in 1955 two scientists named Emilo Segre and Owen Chamberlain discovered something called antimatter which is matter but made out of positive electrons and negative protons. Since the discovery of antimatter, we have been able to make antimatter in the laboratories and study their properties. Interestingly an antimatter behaves exactly the same way as matter but on collision they annihilate one another, leaving behind only energy. Now here is where things become interesting. When the universe evolved, it should have created equal amounts of matter and antimatter and in the next few seconds of the inception of the universe, matter and antimatter would have collided vanishing and leaving absolutely nothing but after thirteen billion years, mostly all the universe is composed of matter so where did all the antimatter go? What if after the big bang, a force ,similar to repulsion, would have prevented matter and antimatter colliding leading to the antimatter forming a completely different and its own universe where humans just like us would be questioning the existence of matter. Where humans just like us would be studying the same physics class but a different history one!
The second compelling argument for why multiverses exist is given by science’s most successful branch, quantum physics. Quantum entanglement is a phenomenon which states that two states of matter gets entangled. In quantum physics, entangled particles remain connected so that actions performed on one affect the other, even when separated by great distances. For example if you absorb that electrons of atom A moving in clockwise direction and then move on to observe movement of electrons of atom B (of the same matter) then you would observe that the electrons of atom B are revolving in an anticlockwise direction which is opposite to the movement of electrons in atom A leading the states getting entangled. Consider placing a cat in a box with a bomb which has only half the probability to blow off. Until you reopen the box, there is no way of knowing whether the bomb exploded or not, and thus, no way of knowing if the cat is alive or dead. In quantum physics, we could say that before our observation the cat was in a superposition state. It was neither alive nor dead but rather in a mixture of both possibilities, with a 50% chance for each.
The bomb in a superposition of decayed and not decayed gets entangled with the detector and in turn the cat, now remember we are also made of electrons and atoms which obey the laws of quantum mechanics so we are quantum mechanical - so when we open the box we get entangled with the state of everything inside the box so we see the cat alive and we see the cat dead. Before you are going to call me loon and say how could a cat be both alive and dead, hear me out. It's because the you that saw the cat alive and the you that saw it dead actually inhabit separate worlds, by that I mean they exist in their own complete realities and those realities will never interact creating your parallel self in a parallel universe. It says that there are millions of parallel universes actually inhibited by you but doing exactly opposite things. You might have parked a car in a parking lot in your world whereas in another universe your car might have been stolen. This theory might be criticized or considered too unrealistic but many scientists believe in this strongly and are working on to bring it forward and show it to the world and maybe one day with the development of Quantum computers being able to perform very precise and lengthy calculation, which would have taken us thousands of years, in fraction of second then maybe we could come on a conclusion of the existence of parallel universes.
Many would find the idea of a parallel universe too fascinating and unreal but as our science is expanding day by day we are realizing that this idea might actually be real. Many theories like string theory only works if we include different universes, even successful theories like the expansive universe says the same. In addition, a recent research by NASA found few abnormalities in the data which could only be sufficed by the idea that parallel universes do exist. Even though we are few miles away from finding real hard proof; we strongly believe that our universe might just not be alone and discovery of the same could bring a complete revolution in everything we know.