What Does Thermodynamics Have to Do with God?

Christians are frequently asked by unbelievers to “prove” that God exists. While many Christians know from experience the truth of God’s existence, it is difficult to offer those experiences as proof of God to a skeptic and a scoffer. They are typically demanding proof be given through some kind of scientific way.

While many Christians know that science confirms the existence of God, they are not quite sure how to walk through that evidence with an unbeliever. Some may even go so far as to reference the 1^st and 2^nd Laws of Thermodynamics as a proof of God’s existence. But some may not be able to fully articulate how that proves God is real. In fact, many atheists mock the reference to those laws because they have not been presented as proof in the correct way.

So what are the Laws of the Thermodynamics and what do they have to do with the existence of God?

The Laws of Thermodynamics are a set of scientific laws that define how heat, work, and energy relate to one another. Keep in mind, scientific laws are not invented by humans but simply discovered by us. Scientific laws are a description of how things interact based on repeated experiments and observations. So while the existence of God isn’t proved directly through a scientific method approach (because we cannot weigh, measure, observe, and perform a repeatable experiment on God), that does not make God’s existence any less real. We will prove God’s existence as the logical deduction from things that can be proven through the scientific method. The Laws of Thermodynamics are a perfect example of this.

The First Law of Thermo states that matter cannot be created or destroyed. The Second Law of Thermo states that all natural processes tend toward entropy, unless energy is applied to the system. But how does that affirm that God exists?

The use of these laws actually must go back to the discussion of the cause of the universe. Our existence – the existence of the universe – must be explained in some way. Before we get into the science of it though, we can use logic to look at the possible explanations for our existence.

1. The universe is eternal. It has always existed and always will exist. If this is the case, then the universe doesn’t need a cause. It has just always been.

2. The universe is not eternal. There really isn’t a third option. The universe either is eternal or it is not. The universe cannot be semi-eternal. However, if the universe is not eternal, then it does require some kind of cause. Though finding a cause for the universe could seem overwhelming, there are only two possible causes: itself or something else. Either the universe created itself, or it did not create itself.

It is from this point of logic where we will begin to determine if God exists. Many people say God’s existence is not necessary because the universe has always been here. Eternal things do not need a cause. Eternal things have always existed and always will exist. If the universe is eternal, God is not necessary. In fact, in the early 1900s, scientists relied on the argument that the universe was eternal to avoid having to account for a god. There was even a theory, the Steady State theory, that proposed there was the continuous creation of matter to eventually generate the entire universe. However, the work of Albert Einstein, Alexander Friedmann, and Edwin Hubble painted a different picture. Through their observations of the universe, each of them concluded that the universe had a beginning, a starting point in time. They even coined a term to refer to this beginning: the Big Bang Theory. The Big Bang Theory acknowledges there was a singularity event from which the universe began, meaning the universe is not eternal.

In addition to those observations, the Laws of Thermodynamics prove the same point. The First Law of Thermodynamics states that neither matter nor energy is created or destroyed in nature. Matter can be converted to energy and energy can be converted to matter, but the total of amount of matter and energy in the universe remains constant. This was the breakthrough discovered by Einstein when he related mass to energy in his famous equation, E = mc². From this law, it indicates we have the same amount of matter and energy now as we have always had. Therefore, the universe could not continuously create its own matter. Matter cannot be further created so what we observe today is what we started with. It had to have been placed here by some cause. There was some beginning to this amount of matter and energy in the universe.

The Second Law of Thermodynamics states that all things tend towards entropy—or disorder and decay, unless energy is applied into the system. There are plenty examples of this all around us. Your garden left unattended will no longer be neat and orderly. Left unto itself, it will go to disorder and decay. Everything is slowly degenerating and breaking down over time. Yet eternal things do not decay. Therefore, if the universe is decaying, then the universe is not eternal. It reminds us that the universe has a beginning, and it will have an end.

All three scientific discoveries – the existence of a singularity event and the First and Second Laws of Thermo – prove the universe is not eternal. The universe’s existence requires some kind of cause. While many describe the singularity event in terms of the Big Bang Theory, the Second Law of Thermo can also be used to combat some ideas found in the Big Bang Theory. In that theory, there was a massive explosion (the big bang) that resulted in the universe. But according to the Second Law, natural processes tend toward entropy, not order. An explosion would not settle into the orderly design seen in this universe, from planetary motion to cellular replication. Our universe is very ordered and precise. The intricacies of biology, the fact that all the forces that govern matter are precisely what they need to be to have life here, the symbiotic relationships of things like plants giving out what we breathe in and vice versa, show there is tremendous order here. That cannot happen naturally out of a chaotic event. In addition, there is the obvious question of what exactly was banging together for this explosion to happen. The universe is not eternal so the existence of whatever exploded must be explained.

Going back to our initial logical breakdown, the first possibility of the explanation of the finite universe is that it created itself. However, if the universe created itself, it would be both the cause and the effect. Plus, something cannot create itself if it does not yet exist. This breaks with all laws of logic and reasoning.

We are left with the only true option. Something outside of this universe made this universe. If our universe is defined as time, space, energy, and matter, then whatever caused this universe must exist outside of time, space, energy, and matter. In other words, God.