The definition of how the universe started is widely combined under The Big Bang Theory that started about 14 billion years ago. It is a prevailing cosmological model that defines our universe’s past and explains the existence of the observable universe. But what about the future? By the Law of God, everything that is created is bound to end and so is the fate of our universe- How is our universe going to end? This is an important question among Astrophysicists who break it down into three possible theories about ‘The End’. The three possible answers to this question are the Big Freeze, the Big Rip, and the Big Crunch.
To understand these theories, it is important to know about dark energy. Cosmologists suggest that our universe is expanding at an unbelievable rate and will keep on expanding. It is similar to throwing a ball and watching it go away from you wider and wider. But the only way why we are still revolving in our own orbit is gravity. The gravitational force of the universe is doing its best to hold everything together but this also means that there is also a repulsive force that is acting opposite to gravity keeping our universe from colliding. In essence, there are two forces holding galaxies together and preventing them from the collision as well as ultimate expansion.
According to astrophysicists, the force that keeps our galaxies from colliding is called dark energy. It is invisible and the least is known about it. However, scientists assume that dark energy makes up to 70% of the universe. Thus, the above three theories are based on the basic concept of gravity and dark energy.
How the universe is going to end?
The fate of our universe depends upon two forces- gravity and dark energy.
The Big Freeze: This theory is based on the prediction of what would happen if the repulsive force of the universe pulling objects apart overcomes the gravitational force and though the gravity will remain there, it might not be enough to hold the universe together. In this scenario, the galaxies would first tear apart followed by small black holes, planets, and stars.
This way, planets and objects within the galaxy would move away from the sun until they dissolve into lonely objects. They will eventually float alone in the vast space and the light they emit would be redshifted to long wavelengths into low energies and that gas emanating from them would short of creating new stars. As a result, the universe would become darker and colder, approaching a frozen state. This all the objects including life in the universe would freeze to death also known as the Heat death of the universe.
The Big Rip– But what if this repulsive force is so strong that it breaks the gravitational force? In this scenario, it will overcome not just gravitational force but also electromagnetic, weak, and strong nuclear forces that hold atoms and nuclei together. If the expansion continues, this force will not just tear apart galaxies and universes but also break them down all the matter that makes up the universe. This theory is called the Big Rip. The entire universe will end up becoming tiny isolated particles drifting aimlessly around.
The Big Crunch– If we assume that cosmologists are wrong and there isn’t as much dark energy around there as imagined then it means that eventually, it will be the gravitational force that wins out. After trillions of years, if this happens, the gravity will bring universe expansion at hold or maybe reverse it. It would result in galaxies shrinking together and universal objects coming closer to each other resulting in the ultimate crash. The temperature would rise as space would get tighter and compressed in a small space. The heat would rip apart atoms initiating the Big Crunch. The black holes would then make up one mega black hole that will hold the entirety of the universe.
This theory sounds exactly like the Big Bang, isn’t it? In fact, what if the end is the beginning of another universe but also how many times have had it happened already in history? There are so many questions that remain shrouded in mystery as we know the least of what this magnificent universe holds.