An article taking us deep down into the possibilities of our universe having a boundary or not.
Universe, a mysterious realm of endless questions. A place where the obvious doesn’t exist. Where we drift into limitless possibilities. And one such possibility which itself gives birth to a mind boggling question is, does the universe as we know it, have a boundary? Few possible theories have been put forward which might lead to the greatest revelation of our generation.
1. Upon venturing into the most controversial question of the era, the strongest theory which emerges is Hartle-Hawking state. But don’t get your hopes high since this theory is all about denial about any sort of a boundary, like our earth, which has no edge or limit. It talks about the beginning of our universe, when time was yet to be born and only space existed. This theory is dependent upon quantum mechanics and wave function theory, considering the universe a particle like an electron. Now, if the value of a wave function is high, then the particle, in our case our universe, exists with a good probability, in a particular state. But if value is less, then yes low are its chances of existence. When Hartle and Hawking carried out observations for all observable universes [which should mean that there must be a boundary in order to reach another universe], they found out that only our universe’s wave function was high enough as compared to the other probable universes’, making their existence questionable. And that means only our universe exists, like a sphere with no boundary or edge.
2. Well Hartle-Hawking state did have some loopholes of its own. To contradict it, some theories were put forward. Hartle and Hawking do support the expansion of our universe. They know that the universe will one day collapse under its own gravity. And here comes the real pickle. Observations of present time suggest that there is not enough matter in our universe to create sufficient gravity to re-collapse it. And yes our dear universe is expanding at a rate faster then we previously imagined it. This makes scientists in favor of the idea of an open universe, which will continue to expand. And since this theory can’t be denied, therefore Hartle-Hawking state must not be true.
3. Now we know our universe is expanding, but into what? Now that is some major brain-collapsing question to shed our hair. Well, space is definite, as believed by some scientists. Now imagine our space as surface of our balloon. We don’t need extra material on our balloon to make extra room rather we stretch it. Similarly, universe/space is not making extra sections through its expansion, it’s simply spreading itself out. Imagine spilling milk on the floor. It will spread out, yes, but still it’ll spread with some boundaries, however irregular they may seem. I hope you have gotten my point.
4. We all know that light is the fastest matter that has ever existed. We only observe what is being reflected back to us by it. Now there are numerous places in our universe where light has yet to be reached for us to see them, and ‘probably’ the boundary of our universe is one such place. Well, our universe is indeed a darn big place to explore. We still don’t know what exactly lies beyond our solar system. So yes, maybe the boundaries are patiently waiting for us to reach them.
5. In the next theory for our topic, according to Hubble law and some of our scientists, the age of our universe is estimated to be 13.7 billion years. So we can assume the radius of our universe to be 13.7 billion light years (since light year is a measurement of distance). And since nothing can go faster than speed of light, than it must be the only thing that has travelled that much distance. So folks, we can theoretically state that 13.7 billion light years is the limit of our universe at present.
6. Now there’s this theory of multiverse or multiple universes. So if so many universes do exist out there, in which one of them I may actually be ruling England, thank you very much, then it means these universes must be aligned together. And that also means that in order to go into another universe, where I hopefully may bask in the limelight with my other self, I have to cross this universe. And when do we cross something? Yes, when it has a boundary.
7. As I have stated earlier, our universe is expanding. And many scientists and physicists firmly believe that it’s expanding into nothingness. I mean from last 13.7 billion years, the universe is just spreading out, hitting no walls yet! So maybe, there is no edge, maybe there’s no boundary of our universe. Maybe we are heading towards…..nothing. Sweet!!
8. But we have Bubbletheory, which both confirms as well as denies the existence of the boundary. Actually it’s a sub-theory of multiverse which obviously takes into account many ‘unobservable’ universes. It states that post big-bang expansion caused bubbles, which are actually an area that stopped stretching, to form into space. All of the bubbles formed their own universes and laws. Now I quote from an article “In this scenario, space is infinite. If you are somehow able to breach the boundary of our bubble, then the space between is still expanding, so you just won’t be able to reach another bubble.” So in short, yes we do have a boundary, which can’t be reached.
9. Well all last points were pure science. But if we try to tip into the world of religion, then some light is indeed shed onto this topic. According to one article, which by far really did impress me with its argument, that God lies beyond the boundary of our universe, who is unimaginable and thus no real boundary can ever exist. Now, for all the science-loving sweethearts, this may seem a bit too far-fetched. And indeed some scientists did oppose saying “When the universe is imaginable made of imaginable cosmic energy as the fundamental cause, how can you say that universe is unimaginable?” For this, a simple statement was given. When we reach the boundary of our imaginable universe, we must perceive the imaginable nature of our universe on our side and the unimaginable nature of the one on the other side. But if that other side’s nature also becomes imaginable, then the boundary of imaginable nature is not achieved. On the other hand, if that unimaginable nature cannot be imagined by our intelligence, it means we had never reached the boundary of the imaginable universe. Now it may seem a bit confusing, ok a lot confusing. But go on, read it again. Read? Finally getting some idea, yes. Well according to me, this is the best theory for determining the boundary of our universe and yes a crisp slap on the face of our science.
If all these theories are clipped together, then we can say is that well there is definitely some limit, an edge for our universe, only we don’t have the intelligence and yes the technologies to perceive it. And of course, we poor beings are born in the wrong century, when the mysteries of our universe have slightly started to unravel themselves. We can only hope to wander a bit more far into those enigmatic depths of our universe before our bodies unite with the stars, forever.