what is the fate of the universe? How will universe end??

Everything which starts must end. Every story has a climax, may it be a movie or life, book or the universe. The universe started with the big bang and is expanding since then. There will be a time when it will die as everything else. 

Why would this happen in the first place? How will universe come to end? What will happen to the humans and other living beings? How can we save ourselves? we will try to find the answers to all these questions. 

Let’s get started… 

Why will the universe die? 

The second law of thermodynamics states that the total entropy of the universe always increases. Entropy means the degree of disorder in everything. In simple words, everything must age and run down. Let’s take some examples and try to understand entropy: -

* When coffee falls on the floor, its entropy increases. 

* When you successfully arrange all the pieces of Jigsaw puzzle, its entropy decreases. 

* Ice melts into water, its entropy increases 

* Coal burns into ashes, its entropy increases

One thing common in all these examples is that when the disorder increases, entropy increases and vice versa. Entropy is the reason why water can’t be transferred to a height without doing external work (like water pump), entropy is the reason why our coffee gets cooled after sometime, entropy is the reason why our cars and other machines work. In everything around us, entropy plays an important role.   

Entropy is increasing and ultimately it will reach to the peak or we can say to its maximum, that will be the end of the universe. It will not happen suddenly but gradually. That gradual process from the birth to the end of the universe can be divided into 5 stages. 

Stages of the universe  

Fred Adams and Gregory Laughlin divided the age of the universe into 5 stages. We will take a look at the different stages: -

Fred adams and Gregory Laughlin

1. Primordial era 

This is the era in which the big bang happened. Our universe came into existence in this era. The expansion and cooling of the universe, super force broke into 4 parts (gravitational force, electrostatic force, weak nuclear force and strong nuclear force) all these took place in this era. Universe was opaque and sky (space) was white at the beginning. After 3,80,000 years, atoms were formed and the sky became black. Hydrogen atoms fused into helium, as a result Steller fuel was created. Life, as we know, was not possible. With the formation of life, the primordial era ended.    

2. Stelliferous era 

This is the stage in which universe is at present. At the beginning of this stage hydrogen rich stars were formed. Life came into existence in this era. This era will continue for few million years. Ultimately our sun will turn into a red giant. The next era will be started with the phase of the sun as red giant.

3. Degenerate era 

In this era the energy of the stars will begin to exhaust. The stars will be converted into either dwarf stars or neutron stars or black holes depending on their masses. The stars will run out of fuel and stop shining as they shine now. As a result, universe will become dark, temperature will fall, freezing everything, we know. Our home planet will freeze too. 

4. Black hole Era 

With the end of degenerate era, most of the stars will be converted into blackholes. The remaining will eventually become black hole. The only source of energy remaining will be the evaporation from the black holes. 

The evaporation from the blackholes is known as Hawking Radiation. It is too weak to be detected. With the extinction of sun, our energy source, can we survive?  Before answering that take a look at the final stage. 

5. Dark era 

This is the final stage of the universe. In this stage, every heat source will be exhausted, including the blackholes. The temperature will approach to 0 kelvin. All atoms will stop. 

This is due to 3rd law of thermodynamics. Third law of thermodynamics states that at 0 kelvin the atoms stop vibrating. 

This will be the end of our universe. 

The end of the universe 

There are many factors determining the end of the universe like the shape of the universe, the dark matter, the dark energy, etc. We don’t know about the 96% of the universe. Based on our present knowledge physicists have speculated 3 possible ways in which universe could end. Those are: -

1. The big Freeze 

As we have discussed previously the universe is expanding. The universe was hot earlier and with the expansion, its temperature is decreasing. So, in the far future the temperature of the universe will decrease more, approaching to absolute zero (0 kelvin). This will be the stage of maximum entropy. 

The black holes will disintegrate, the galaxies will move apart and won’t be visible to us, the stars will die and the protons will decay. All will die because of freezing cold. That’s why it is called BIG FREEZE.

 2. Big rip 

We know that the universe is not only expanding but also it is accelerating. This means that the farther parts of the universe are expanding at faster rate than the nearer parts. There will be a time when the galaxies will be far apart from each other. The star clusters of all galaxies will move apart. After that the planets then ultimately, the atoms will move apart from each other. In short, everything will be ripped apart from each other, tearing the universe and leading to its end.  

3. The big crunch 

This is the scenario in which the universe stops expanding and begins contracting. Let’s take a feel of the situation, imagine throwing a ball in the air vertically upwards. The ball rises to a height and after sometime it starts falling towards you. why does this happen? It is because the force applied by you on the ball takes the ball to that height but as soon as the force decreases to zero, the gravity pulls the ball towards the surface of Earth. 

Same will be the scenario if the Big Crunch happens. The universe is expanding, it is possible that in the far future the gravity begins to show its affect. If this happens then everything will start moving towards each other. Ultimately leading the universe to turn into a blackhole. 

All of these are the possible scenarios. Physicists don’t know exactly which of these will turn to be the fate of the universe. This is because we are unaware of the dominating part of the universe i.e. the dark matter and dark energy. Secondly, we are unaware of the shape of the universe. These are the important parameters needed to find out the ultimate fate of the universe. 

Can intelligent life survive? 

The intelligent life means, for Earth, we humans. There might be another form of intelligent life on other planets whom we call aliens. The survival of intelligent life depends on the 2 questions. 

1. Can machines operate in that era? 

Thermodynamics states that the higher the temperature difference, the greater will be the efficiency. The temperature difference decides the movement of energy. As we discussed above, the universe will reach to 0 kelvin of temperature. This means that our body temperature will reach the freezing point of water. So, it will be difficult for us to survive in the flesh and blood body. Hence the suitable option will be to go for android bodies which we have discussed previously. The robotic bodies can withstand the cold in a better way than our biological body. The survival of us in robotic body depends on the second question. 

2. Can information be transferred at 0 kelvin temperature?      

The information theory states that the small unit of information transferred is directly proportional to the temperature. So, in order to transfer information at 0 kelvin temperature condition, the unit of information should be much smaller than it is today. The transfer of information is an important part for our survival. The only option remaining will be to “think slowly”. In this way the unit of information can be made smaller. 

Ultimately the survival of human depends of the conservation of energy. If we are successful in conserving energy, we would increase the chances of our survival. This is what some insects and animals do in winter. Hibernation helps in conserving energy.  We need to obey the laws of thermodynamics and information theory in order to survive the ultimate fate of the universe. 

The chances of the survival of intelligent life are very low. It is because of the expansion of the universe. According to the laws of physics, intelligent life is doomed to perish. But what if we could escape the universe??

There is no need to worry for us neither for many more generations to come. Scientists estimate that there are almost 50 billion years before the universe meets its fate. Till then we can find several methods to escape the universe and reach another universe. There are many universes like ours in the big multiverse. 

Thankyou for reading till the end. I hope you like it. What are your thoughts? let me know in the comments below. If you have any topic suggestion then also let me know 

Do aliens exist? 

What is the multiverse and do it really exist? 

What is the android body?  

How do we know that universe is expanding