Entropy of the finite universe

"Some may find it perplexing but it is a simple question of a mathematical equation. A wasteful body cannot be eternal. If it is eternal, it cannot be wasteful."
"Some may find it perplexing but it is a simple question of a mathematical equation. A wasteful body cannot be eternal. If it is eternal, it cannot be wasteful."

When one ponders about the existence of God, one should remember that, though it is reasonable and natural to question the existence of God, it is necessary for one to be of pure intention for a fair conclusion to one’s thoughts or arguments which should be reached after thorough research. The existence of God can be proven through logic to an extent but one can only believe in The Existence of God through personal experience. Our beloved Huzoor, Hadhrat Khalifah-tul-Masih V abaabbreviation for "May Allah be his helper" has advised us many times that we should share our own personal experiences with God with those whom we try to convey monotheism to. However, some atheists will only accept physical answers and want a completely scientific argument for the existence of God. For example, they want to actually see God with their eyes to believe in His existence, despite it taking away the whole purpose of belief and life itself.

The argument I will be discussing in this article has been beautifully explained by Hadhrat Mirza Tahir Ahmad, Khalifah-tul Masih IV rhabbreviation for "May Allah have mercy on him/her/them" in his inspiring book ‘Revelation, Rationality, Knowledge & Truth’. It is regarding the ‘finiteness’ of the universe and how the universe originated and will ultimately meet its end. The base of the argument is the cosmological argument, also known as the first cause argument, which states that every effect must have had a cause to make the effect happen. Let’s look at an example: a watch requires a watchmaker to assemble the different components of a watch to build it and so the watch is made. The universe’s existence is an effect itself, so a being must have caused this effect. We call this being ‘God’. Most people from this point question, ‘Who caused God if everything has a cause?’. This is what comes to almost everyone’s mind when this argument is brought up – however, the answer is quite logical: There cannot be an infinite number of causes, i.e. there can’t be an infinite number of Gods who created each consecutive one, as it leads to an eternity of causes with no actual first cause which completely depletes the point of finding a first cause. If there is no cause at all, to affect the universe, then it means that we don’t exist at all! So the simple answer is that there must be an Uncaused Cause which created the universe: One who is “Independent and Besought of All” (The Holy Qur’an 112:3)

Hazrat Mirza Tahir Ahmad  rhabbreviation for "May Allah have mercy on him/her/them", 4th Khalifa of the Ahmadiyya Muslim Community

To further elaborate, everything depends on something, however useful it may be on its own. For example, one of the primary causes of life on Earth is the Sun, as it provides light and heat for plants to grow and for the water cycle to work etc. But the sun itself is not independent or eternal as it is slowly running out of fuel and will eventually become a Red Giant no longer providing any assistance to life. Neither was the Sun always there as it formed from dense gases over thousands of years. Hence, the universe demands a being who is Independent and one who is free from the limits of time itself. That is none other than Allah The Eternal.

It does not end here, unfortunately. The atheists reply with an interesting idea, saying that the universe itself was never created and has always existed. They argue that the universe itself is the first cause. The actual theory and concept used to come to such a conclusion are actually acceptable. In fact, we Ahmadis accept most of the theories which they use but have a more logical concept and conclusion relating to it. By this I do not mean that we believe that the universe is the first cause itself; rather, the theory they use to claim the universe is Eternal is mostly correct but their conclusion of it to mean that the universe is Eternal is wrong. I will explain this further in the article. The concept is that this universe was born out of a previous universe’s black hole, and that universe from an even ‘earlier’ universe’s black hole, and that from another previous black hole, and so on…

To discuss any further about the theory and the actual answer to the argument of the eternity of the universe, we need to understand the second law of Thermodynamics called Entropy. Imagine you place a fresh cup of coffee in a closed room. What happens to the coffee? Obviously, the coffee cools down, right? Why does the coffee cool to the ambient temperature of the room and not heat up with the energy of the air particles around it? This is simply because the particles of the coffee transfer their energy to the particles of the air above the coffee, and the cup’s particles themselves transfer their energy to the particles of air around the cup. For example, when you transfer a warm drink from one cup to another constantly, the drink cools down faster because the liquid contacts more of the air particles and there’s more liquid itself exposed to the air; so more of the energetic particles of the warm drink can transfer their energy to more of the cooler, less energetic air particles. The air particles have energy too, so why don’t they instead transfer their energy to the coffee? Without the help of any external system, this is simply not possible due to the second law of Thermodynamics.

The second law of Thermodynamics

The Second Law of Thermodynamics relates to the overall disorder or the overall wasteful energy in a closed system. To first understand entropy, we need to understand what wasteful energy is. Wasteful energy is the amount of energy in a system that can never be used again for a reaction or process. It may sound like an alien concept to most of us as we are commonly taught in school that ‘Energy cannot be created, nor destroyed’ ~ according to Julius Robert Mayer. However, wasteful energy is not that which is destroyed, but it is the energy which is never available to be used again in a system. The fact that Energy is constant in the universe relates to this law because if energy could somehow be added to the universe, then the system’s Entropy wouldn’t tend towards a maximum as it could always be reduced by adding energy. This will seem clearer further on. Entropy is the law which states that the quantum of wasteful energy always increases and the quantum of useful energy continues to fall.

What is Entropy

Entropy is the law which gives time a direction! When a process occurs which is thermodynamically positive or feasible, the energy in the system becomes more disordered. This means that the particles have been ‘disarranged’ from an orderly manner to a disordered state. This means that the particles are almost infinitely unlikely to arrange themselves in an order to be used. There is some energy released during reactions which cannot be used again as it becomes part of the universe’s ever-increasing wasteful energy. For example, when a child makes a sand castle on the beach, the sand is arranged in a very ordered way which requires a lot of energy to make and arrange. But just the slightest breeze will topple the castle. The very well-arranged castle is easily destroyed with much less effort than is required to build it. This can be explained through probability. The chances of a breeze moving sand particles in such a way that a sand castle is formed by itself is infinitely small that it is considered impossible but with enough energy (such as the energy and intelligence of the child), it is something that is feasible. Entropy does not mean that a system can only go from disorder to order but the overall system (i.e. the universe) tends to a maximum disorder. This is because there can be no energy added to the universe to decrease the Entropy of the overall universe. This was theorised by the German Physicist Rudolf Clausius who is known to be a very important figure in the study of thermodynamics. He said that:

1. The energy of the universe is constant.

2. The entropy of the universe tends to a maximum.

(Rudolf Clausius, Ninth Memoir. On Several Convenient Forms of the Fundamental Equations of the Mechanical Theory of Heat (1867))

Now we have sufficient knowledge of Entropy that we can continue the argument. The ‘theory’ of repeating universes and Black Holes is a combination of the two theories:

The Big Bang and the Big Crunch

The Big Bang is the widely accepted theory that the universe came from a singularity and expanded out into the very existence it is right now and is still expanding. It is known to be originally definitively theorised by Georges Lemaître – who was a Belgian Physicist and Catholic priest. Later on, after him, many scientists further expanded his theory and some more discoveries were made derived from this one. For example, the expansion of the universe was hinted at by Georges but Edwin Hubble claims the theory and has founded Hubble’s law.

The Big Crunch is a theory about the predicted end of the universe which was founded by John Wheeler. Scientists believe the universe could implode in on itself by getting sucked into a Supermassive Black Hole. This is something some scientists believe to be the most likely if not definite, fate and origin of ‘All/previous universes’. Allah the Almighty talks about the Big Bang and the Big Crunch in The Holy Qur’an almost 1400 years ago:

Remember the day when We shall roll up the heavens like the rolling up of written scrolls by a scribe. As We began the first creation, so shall We repeat it—a promise binding upon Us; We shall certainly perform it.

(The Holy Qur’an 21:105)

The rolling up of the heavens is a likely reference to the possible ‘Big Crunch’ which is the Big Bang reversed. This is the base behind the belief that the universe is self-existing and eternal. Atheists try to misinterpret the orderly Majesty of The Creation by claiming that nature is the only cause behind it and that the universe itself is self-sustaining.

Scientists believe that The Big Crunch could repeat for our universe as well, but some scientists are more inclined to believe in a different path to the end of our universe… One of the still unsolved mysteries in the universe is its ever-accelerating expansion. The universe seems to expand faster and faster over time while theoretically, it should be slowing down. It is theorised that the expansion will accelerate even faster than the speed of light. As the universe tends to a maximum disorder, the energy will be ‘wasted’ to such an extent that the universe would be left with nothing but wasteful energy. This means that eventually, however remote of a time to us, the universe must have no processes left to undergo – as the useful energy would all have been ‘used up’. A complete state of Equilibrium would be reached where there would be no further reactions and the universe would come to a Halt – there would be no cause left to cause an effect, as the universe would come to a standstill. Entropy will have consumed our universe!

The only solution to the dilemma of Entropy and the origin of the universe is that every universe is not recycled into a new one, rather it is Allah the All-Powerful who creates a new universe after the former has served its purpose.

A scientist, Paul Davies, who supported this concept wrote in his books the following few extracts: In his book ‘God and the New Physics’, Davies writes:

“If the universe has a finite stock of order, and is changing irreversibly towards disorder— ultimately to thermodynamic equilibrium— two very deep inferences follow immediately. The first is that the universe will eventually die, wallowing, as it were, in its own entropy. This is known among physicists as the “heat death” of the universe. The second is that the universe cannot have existed for ever, otherwise it would have reached its equilibrium end state an infinite time ago. Conclusion: the universe did not always exist”

Davies in his book ‘The Mind of God: Science and The Search for the Ultimate Meaning’ writes:

“At the heart of thermodynamics lies the second law, which forbids heat to flow spontaneously from cold to hot bodies, while allowing it to flow from hot to cold. This law is therefore not reversible: it imprints upon the universe an arrow of time, pointing the way of unidirectional change. Scientists were quick to draw the conclusion that the universe is engaged in a one-way slide toward a state of thermodynamic equilibrium. This tendency toward uniformity, wherein temperatures even out and the universe settles into a stable state, became known as the “heat death.” It represents a state of maximum molecular disorder, or entropy. The fact that the universe has not yet so died—that is, it is still in a state of less-than-maximum entropy—implies that it cannot have endured for all eternity.”

Let’s assume that the universe is eternal in relation to its past; so there have been infinite loops of Big Bangs and Big Crunches.

Eternity and wastefulness cannot co-exist

If the universe ends with a Heat Death, there will be an end to the loops of Big Bangs and Big Crunches, and so there cannot be infinite loops of Black Holes. The fact that the Heat Death of the universe is probably depletes the whole idea of Eternity. This is beautifully explained by Hadhrat Khalifah-tul-Masih IV rhabbreviation for "May Allah have mercy on him/her/them" in his book, which I have been inspired by to write this very article: Revelation, Rationality, Knowledge & Truth. Huzoor rhabbreviation for "May Allah have mercy on him/her/them" explains:

“Wastefulness and eternity cannot go hand in hand. Everything wasteful must come to an end. But lo! We are here, both the writer of these words and the reader at this moment in time. The universe which gave birth to us has no right to occupy this point in time along with all the inanimate forms of existence, if it were eternal. Some may find it perplexing but it is a simple question of a mathematical equation. A wasteful body cannot be eternal. If it is eternal, it cannot be wasteful. The only option left to us is to believe in an Eternal Creator Who is beyond and above the reach of entropy and wastefulness.”


The above extract from Huzoor’s  rhabbreviation for "May Allah have mercy on him/her/them" book explains the argument perfectly. Many scientists in the world have agreed upon the fact that an actual infinity in our universe is metaphysically impossible. If we were to exist in a universe which is part of a chain of universes, then it would have required infinite universes for us to get to this point in time. As the German mathematician David Hilbert said ‘Our principal result is that the infinite is nowhere to be found in reality. It neither exists in nature nor provides a legitimate basis for rational thought’. This is true for all cases other than the existence of The Eternal Being which, in fact, created the whole of the universe. We see that most scientists who disagree with infinity understand that the universe cannot be eternal. However, logic through the cosmological argument leads us to believe that there has to be one primary cause to all causes in the world if we are to believe in even our own existence. This is because if we do not accept that an uncaused cause has caused the creation of the universe, then we are led to believe that nothing exists at all. We cannot believe the universe to be the uncaused cause, as it has been proven it will not last forever because entropy should have consumed it an eternity ago if it were the case. Therefore, only one solution remains. But as I said at the start of this article, one can only fully have certainty that a Benevolent Creator exists after personal communication with Him.


This article was originally published in the Annual Printed Edition of Majallatul Jamia

Talha Ahmad

Talha Ahmad

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