We’ve all thought about parallel universes in one way or another. The idea of an alternate reality where you didn’t make that mistake or had studied for that test. Even regret falls into that category, the idea of “What if”. It fascinates us all. But is there such a place in science for such wistful speculation? If the universe is actually what we can see, this notion can’t be real right? Because otherwise, the pair or whatever else there was would actually be everything.vv
Physicists often say universe when in actuality they mean the observable universe. The observable universe is the part of the universe which we can see. Because light doesn’t travel fast enough, we can’t see beyond that. But most likely, the universe is much more than that. If the universe is taken to be that, then yes, there are multiple observable universes for different observers. But that’s different from parallel universe.
It is important to mention that no scientific evidence exists for any of these so anything we mention is just imagination and speculation. But we should remember that the idea of a universe beyond our solar system and galaxy was also once speculation.
Often in science fiction, when “parallel universe” is talked about, it is often meant to be different bubbles of realities. If our universe is actually infinite in the truest sense, then there are no other realities or universes out there. But we know that matter in the universe should be arranged in a finite way. Would that mean that patterns eventually start repeating? We aren’t going to get into the shape of the universe but according to Einstein, this should be applicable in a flat universe, given infinite time.
In physics, the term multiverse is used to describe parallel universes. And in the above thought experiment, the universe is one and it just starts repeating itself indefinitely when all combinations of matter run out. If there was a shortcut like an Einstein-Rosen bridge or a wormhole that existed locally, it could send us to a point where we could be able to interact. It is a possibility however that these different parts of the universe may have different laws of Physics and may prevent survival for a second let alone the interaction. For example, a universe made of antimatter may cause you to explode the moment you enter it (matter interacting with antimatter results in total annihilation)
Another popular idea is that of higher dimensions. A solution of Einstein’s equations for higher dimensions yields beautiful results and it formed the basis of the different string theories. But if there are beings living in that dimension, it is fair to say that we may never witness their full glory being, at best, 4-dimensional beings. Imagine it this way, beings living in a flat plane may never see a 3-dimensional sphere passing their plane. All they’ll be able to see is a flat line changing size. Transcending to the higher dimension might be different though but there would still be limitations to what we can fathom. And then, there’s the idea of the higher dimensions being curled up so close together in the tiniest scales imaginable as most string theories suggest. What kind of interaction can that allow? You can’t even fathom those scales, let alone interactions in them.
There may be a very unorthodox way, in my understanding however, that in terms of religion, the soul and the death realm may exist within the higher dimension. That might offer an explanation to some religious reasoning but strictly under those rules, there is only one of yourself.
There may be no scientific answer to the questions posed, but there’s an endless array of answers in the minds of those that ponder it and whether you talk about religion or science, neither has a definitive answer. But if you can imagine an infinite universe created by an infinite God, it may not be so crazy to think that there’s another version of you somewhere unimaginably far away. Whether there is any physical or nonphysical way to interact with it is really the question of Schrodinger’s cat being alive or dead before the box is opened.
Shawaz Lodhi is a freelance writer and a sports freak.