How will the universe end, and could anything survive?
The universe serves up spectacle after spectacle with so much ease and effortlessness that you cannot help but wonder how it has so many complexities hidden within its ulterior cloak of beauty. On the surface, the universe is magnificent and splendid. The immortal souls that are credited for creating it are not yet finished with it. Perhaps, they get lost in its admiration and in its beauty and lose track of the job at hand. The fact that the universe can be so alluring despite its intricacies is in itself worth cherishing. But, like all good things, the universe will come to an end.
The end of the universe is not near, however, it is inevitable. There might not be any need to set alarm bells ringing anytime in the near future, but, the universe does have an expiration date.There have been several theories on how the universe could end. If the universe has been a cause for fascination and you want to learn more about how it could potentially all end, then, this article is just for you. Read on.
Let’s start from the beginning, the Origin of the Universe
To predict an ending, you would have to understand the beginning. Like all spectacular things, the universe too had a spectacular origin. This beginning was the Big Bang. The Big Bang theory explains the evolution that the universe had to undergo. This theory states that the universe was initially extremely hot and dense.As time passed, the universe began to cool and expand.
According to the Standard model, the four fundamental forces in the universe are gravity, strong and weak attractive forces and electromagnetic radiation. Of the four, gravity is considered to be the weakest. It is hypothesized that during the beginning of the universe that gravity was as strong as the other fundamental forces. All the matter in the universe was condensed into such small spaces that the gravity had to be extremely high. The universe did not stay in this condensed state for too long and began to expand. The expansion is considered to be perpetual and is taking place even while you are reading this.
What is really scary is the fact that the rate of this expansion keeps increasing every second. This expansion is credited to dark energy, but, nobody really knows for sure what it is. Here are the theories that try to explain how the universe could end.
The Big Rip
For as long as we have known, the universe has been expanding. During this process of expansion, lots and lots of space was created. Galaxies began to move apart since the space between them increased. Within the galaxy, the space also expanded. However, the gravity acted as the glue that kept it all together. The gravity provides the force that keeps the galaxies together. It is strong enough to negate the expansion. In the Big Rip scenario, the rate of expansion increases so drastically that it reaches a point where gravity cannot counter or negate the effect of the expansion of space. The acceleration of space expansion would be tremendously high.This causes the universe to, well, rip. This is what is referred to as the Big Rip.
This effect would start with the larger bodies and slowly propagate to the smaller bodies. It would first start with the galaxies. These galaxies would get ripped apart. Then, black holes, stars, and planets would die. Since the gravity is not strong enough, they would simply just dissolve into their constituents. Then these smaller components would disintegrate. Everything we know would get ripped apart.
Space would then start expanding so fast that it would be faster than even light! Atoms and subatomic particles would also tear apart. Since space is moving so fast, there would be no interaction between particles. So, even the small particles that remain after this massive expansion cannot interact with anything in the universe to form bigger particles. This universe would be so strange that when you compare it with today’s universe, it would seem ridiculous.The possibility is unfathomable, but, not impossible.
The Big Freeze
Simply put, the difference between the Big Freeze and the Big Rip is that in the Big Freeze scenario, matter does not disintegrate, it gets converted into radiation in a process that could take forever. To understand this, you will need to understand entropy. The second law of thermodynamics states that the entropy of an isolated system can never decrease, therefore, every body moves to a state which increases its entropy. This means that every body cools down and it disintegrates until it reaches some form of equilibrium. This is true for the universe as well. The matter in the universe slowly disintegrates and spreads out. Every body, whether big or small, will have its matter disintegrating into radiation.
The gas clouds required to generate stars would disintegrate. The universe will become an extremely dark place as a result. The suns would also disintegrate. Black holes would be the only entities left in the universe. These black holes, however, will also lose energy in the form of Hawking radiation and also disintegrate. Slowly but almost surely, only a few light particles would remain. But, even these will eventually decay. The universe would be reduced to nothing. A place of nothingness. Entropy would have reached its maximum, and the highest form of equilibrium would have been reached. The universe would have finally ended.
However, all hope is not lost. The phenomenon of quantum tunneling could cause a change in the entropy leading to another Big Bang. In this case, the universe would just restart as if nothing really happened.
The Big Crunch and The Big Bounce
Gravity, which is the weakest of all fundamental forces could one day become the most powerful. This is possible if the amount of dark energy reduces substantially over time. This would mean that the universe would simply stop expanding. This would mean that the rate of expansion would slow down at some point and keep slowing down until the process of expansion ceases. Then, it slows down even more and reverses. The universe, instead of growing, would begin to contract and become smaller and smaller. Galaxies will merge, and the universe will get significantly hotter. The temperatures would reach such high levels that bodies that cannot bear such temperatures would disintegrate. Everything will get denser.
Black holes that consume everything close to them, would begin consuming bodies. As things get closer and closer, more objects would get closer to black holes. These black holes would consume everything including other black holes. The amount of gravity will be immense. All black holes will eventually form a single supermassive blackhole at the center of the universe. At the last moment of the Big Crunch, the entire universe would be consumed by the gigantic black hole and finally, it would consume itself. The Big Bounce theory states that this entire process has been taking place for a long while. According to the Big Crunch, the universe is stuck in a loop of expansion and contraction leading to many deaths and rebirths of the universe.
The timeline for the end of the universe
Our planet will cease to exist in about 1 billion years from now. The Sun would burn 10% brighter and the heat from the sun would dry up all the water on earth. All life will be extinguished. In about 5 to 8 billion years, the sun would undergo expansion to reach a size that is so big that it would devour most planets. In about 1 trillion years from now, all galaxies would merge into one. In 100 trillion years, we would enter the degenerate era. This era is marked by the death of all stars in the galaxies, which, results in black holes. In 10 to 100 quintillion years, everything would be consumed by black holes. In a decillion years time, we might have the black hole era, where the universe is dominated by black holes. Eventually, these black holes will lose energy in the form of Hawking radiation and die too. In about a googol year, the universe would cease to exist.
Erich Fromm, a renowned psychologist, and sociologist once said, “The quest for certainty blocks the search for meaning. Uncertainty is the very condition to impel man to unfold his powers”. There is so much uncertainty around. Everything in the universe is uncertain, so much so that even the universe itself is uncertain! The universe always has a clever way to teach important lessons. Uncertainty should compel humanity to make the most of the time we have.
The universe can die but it can start all over again. The reality that we observe today may not be considered reality at all in the distant future. Whether the universe ends or not, one thing is certain, the universe should be cherished and celebrated while we can all still bask in its splendor.