Do we live in a parallel universe? Is it possible that we live in a multiverse?
A parallel universe, also known as an alternate universe or alternate reality, is a hypothetical self-contained reality co-existing with one’s own. A specific group of parallel universes are called a “multiverse”, although this term can also be used to describe the possible parallel universes that constitute reality.(Source: wikipedia)
The universe is what that is used to describe collection of all things that exists in space. The observable universe might be 46 billion light years in all directions from our point of view, but there is certainly more unobservable universe beyond that.The universe appears finite to us not because it is actually finite in size but because due to fact that we cannot see the universe beyond that. This does not mean that there isn’t more universe out there beyond the part that is accessible to us. In fact from various points-of-view there is plenty more to observe.
Let us consider an example as mentioned in the book Dark Matter by Blake Crouch “Imagine you’re a fish, swimming in a pond. You can move forward and back, side to side, but never up out of the water. If someone were standing beside the pond, watching you, you’d have no idea they were there. To you, that little pond is an entire universe. Now imagine that someone reaches down and lifts you out of the pond. You see that what you thought was the entire world is only a small pool. You see other ponds. Trees. The sky above. You realize you’re a part of a much larger and more mysterious reality than you had ever dreamed of.”Broadly, there are millions of ponds out there which you are completely unaware of.
Another example would be of legendary Schrödinger’s Cat. A cat, a flask of poison, and a radioactive source are placed in a sealed box. If an internal monitor detects radioactivity (i.e. a single atom decaying), the flask is shattered, releasing the poison that kills the cat. In the case of the Schrödinger’s cat, the cat is the superposition of “dead” and “alive” states. When we open the box, only one of the state is possible that is either the cat is dead or alive. However, one can just as well choose to accept that all these possibilities are true, and that they exist in different universes of a multiverse.
Some scientists believe that we live in a parallel universe that closely resembles to our own universe. In 1954, a Princeton University doctoral candidate Hugh Everett came up with an idea that due to various quantum effects, the universe splits each time an action is taken. In layman terms, it simply means that a universe is created each time you take some sort of action, each universe having different outcomes. An analogy of same can be understood as eating a pizza, then the present universe will give rise to two other universes, where in one you decided to eat pizza(Present me will surely be in this one) whereas in other you decided not to eat pizza. Another analogy would be this, consider a scenario in which you have black hairs whereas in another universe all your body traits would be same but the only difference would be that in this universe your hairs would be brown. So according to theory of Hugh Everett we are living in multiverse of countless universes with multiple copies of each one of us. Beyond the universes that is accessible to us there might exist a multitude of universes which are bounded to repeat themselves. If there exist a multiverse then action you take in this universe might not only affect your lives but the lives of your duplicates that exists on other universes. The idea of parallel universe comes out of String Theory which says that there exists more then three spatial and one temporal dimensions. The laws of physics might work differently in other universes. Here are some theories that suggests that parallel universes exist:
Many scientists believe that big bang could prove that there are other universes, according to a theory big bang was so powerful that it created not only universe and everything but also something known as eternal return, which suggests that our universe is bound to repeat itself over and over again which means that there could be infinite number of parallel universes which contain a world exactly like our own but with different outcomes.
Many people believe that supernatural activities are a result of afterlife but some scientists say that ghosts are nothing but people living in other universes. Ghosts may be vision through breaches between planes and alternate realities in timelines that exists in parallel with ours, which simply means that we will also be acting as ghosts in other universes(Scary, isn’t it?)
Had a dream last night? No one ever knows why we have dreams, some scientists suggests that dreams are closest we will ever get to an alternate world. The ability to travel through time and space suggests that what would be like to be in another plane of existence.
Parallel Universe is just a theoretical concept and some scientists believe that since it’s not observable and provable, it is unscientific to bring it into discussion. However as the humans evolve and technology advances, we might end up with solid proof’s one day and might be able to interact with our duplicate living in some other universe.
Space is deep, dark and full of unresolved mysteries.