The Russian cosmologist Alexander Vilenkin said,
“With the proof now in place, cosmologists can no longer hide behind the possibility of a past-eternal universe. There is now no escape, they have to face the problem of a cosmic beginning.”
On this page we will look at ideas of an infinite universe, a finite universe, and the implications of these beliefs. We will also consider how the first and second laws of thermodynamics (laws which govern the universe) answer the question: why believe in God?
An Infinite Universe
In the 4th Century BC the famous Greek philosopher, Aristotle (a student of Plato) introduced the idea of potential infinity and included the universe as an example of this in the sense that the universe had existed forever in the eternal past with no beginning time and also stretches on for ever with no physical end. So in terms of space and time, it cannot be measured. Aristotle saw the earth as the centre of this perfect universe.
During the middle ages (from 5th Century AD till the Renaissance in16th C. AD) theologians and philosophers were influenced by creation stories found in Judaism, Christianity and Islam. The Catholic Church in particular had a strong influence on what people believed.
The result of this influence saw the development of the idea of a finite universe which had a clear beginning in the past; the universe had not always existed. This was rooted in the belief that "In the beginning, God created the heavens and the earth" (Genesis 1:1).
During the 16th century Renaissance, European academics developed a renewed interest in ancient Greek philosophy and with this, a renewed belief for many in an infinite universe.
Immanuel Kant (a German philosopher who lived from 1724 to 1804) said, "Two things inspire me to awe: the starry heavens above and the moral universe within" (Critique of Pure Reason). He promoted the idea that the universe was infinite because time was infinite (having an infinite past and future) and the universe existed in the time space dimension. Stephen Hawking says that for Kant and just about everyone else in that period, time was absolute, it was the backdrop to everything. Einstein's Theory of Relativity changed that.
A Finite Universe
In 1915, Einstein's Theory of Relativity said that space and time were no longer Absolute. Instead of being a fixed backdrop to everything that happened in the universe, they were dynamically shaped by the matter and energy contained in the universe. They only existed because the universe existed and therefore, apart from the universe it was illogical to speak of either space or time. You could not speak of 'time' before the beginning of the universe because 'time' did not exist before the universe.
With the new scientific technology and discoveries that came after this, many cosmologists now believe that the universe is finite. Many attribute this to the Big Bang Theory, originally espoused in 1920 by a Belgian priest named Georges Lemaître. Lemaître's theory was that the universe was finite and began from a single "primordial atom". This theory was given support through observations by Edwin Hubble who noted that galaxies seemed to be speeding away from the earth in all directions. This it is believed showed an expansion of the universe which implied that at one point in the past, it BEGAN expanding.
Although the Big Bang Theory is now being abandoned by many scientists, it is not actually necessary to provide scientific evidence that the universe is finite. Some of this evidence is discussed below under the headings of the first and second laws of thermodynamics.
Implications of a finite universe
What could a finite universe mean? It means in the first instance, that the universe has a cause. Something other than the universe caused it to come in into being. Those who believe in God would say, "Well, that's simple, God created the universe! An eternal and "uncaused" God caused the universe to exist." For those who do not believe in God, this creates a problem because they must answer the question "How did the universe come into existence from nothing if there is no supernatural external force or energy (God) to create the universe?"
Did the universe create itself?
To answer this question, some have tried to redefine the word 'nothing'. They have come up new definitions of nothing but that nothing still involves something: energy. If that were the case (ie. energy created the matter which exploded into a universe) then where did the energy come from? Other theories have also been explored that might give hope to the idea of a finite universe that doesn't need a creator. But none of these theories (unsupported by any evidence) provide any answer for the way in which the first and second laws of thermodynamics point to an eternal creator God... and therefore a reason to believe in God.
No exemptions have ever been found to the first and second laws of thermodynamics.
The first law of thermodynamics, or the law of conservation of matter, says that all the energy (including energy stored as matter) in the universe (or even one small isolated part of the universe) is constant and never changes. This energy never increases or decreases.
The brilliant Isaac Asimov, biochemistry professor and author of over 500 books, wrote...
“This law is considered the most powerful and most fundamental generalization about the universe that scientists have ever been able to make. No one knows why energy is conserved... All that anyone can say is that in over a century and a quarter of careful measurement scientists have never been able to point to a definite violation of energy conservation, either in the familiar everyday surroundings about us, or in the heavens above or in the atoms within.” [Smithsonian Institution Journal, 1970, p.6].
Energy may change form, transfer or move but there is no new energy being created and no existing energy being destroyed. This is something that can be backed up by empirical scientific data which is both testable and observable.
A simple example is the energy we get from eating an apple. No new energy is produced and none is destroyed. Rather, by certain predetermined processes (who put them there?) energy is transferred from apple to body. The matter and energy still exist but in different forms.
Another example is when you burn a log of wood in a fire. Although it may appear that new energy is created it is actually only transferred in the form of heat. And while matter may appear to have been destroyed, it still exists in the from of soot, ashes, chemicals released.
Because the first law of thermodynamics shows that new energy cannot be created (though it can be transferred) then all the energy that exists in the universe must have been created at some point in the past. This would have to have been done by some independent power that exists outside of the universe. Something, or rather someone, some incredible mind created the universe from nothing! This is a most powerful reason why a person would believe in God.
It is reasonable to conclude that if the natural processes at work in the universe cannot create energy or mass then it is highly unreasonable that we should expect them to create something as complex as one living cell, much less human life! If nothing in the natural can produce matter or energy, then something supernatural must have created them. Why believe in God? Because the first law of thermodynamics cries out that only a supernatural, all powerful God could create something as immense and complex as the the finite universe we live in.
In A Brief History of Time (p. 140-141), Stephen Hawking said, “So long as the universe had a beginning, we could suppose it had a creator.”
The second law of thermodynamics (which says that all things wear out) shows clearly that the universe had a beginning, a time when it was new, and therefore it had a creator!
Not only does scientific evidence show from the second law of thermodynamics that the earth had a beginning but the second law of thermodynamics is also found in the Bible. The following passages for example speak of the the universe will grow old and wear out like a garment: Psalm 102:25-26; Isaiah 51:6 and Hebrews 1:10-12.
This thermodynamic stuff may be new but hang in there as we unpack this unchangeable law of our universe; a law set in motion by sin (Genesis 3:17-18, Romans 8:20-21).
The second law of thermodynamics, or the law of increased entropy, says that over time, everything breaks down and tends towards disorder - entropy! Entropy is the amount of UNusable energy in any systems; that system could be the earth's environment or the universe itself. The more entropy there is, the more disorganisation and chaos.
Therefore, if no outside force is adding energy to an isolated system to help renew it, it will eventually burn out (heat death). This can be applied to a sun as well as a cup of tea - left to themselves, both will grow cold. You can heat up a cold tea, you cannot heat up a cold sun. NOTE: when a hot tea in an air tight room goes cold (loses all it's energy) not only do we NOT expect the process to reverse by natural causes (ie. the tea will get hot again), but both room temp and tea temp will be equal. Keep that in mind as you read the next paragraph.
Look at it like this, because the energy in the universe is finite and no new energy is being added to it (1st law), and because the energy is being used up (2nd law), the universe cannot be infinite. If our universe was infinite but was using up a finite supply of energy, it would have suffered 'heat death' a long time ago! If the universe was infinite all radioactive atoms would have decayed and the universe would be the same temperature with no hot spots, no bright burning stars. Since this is not true, the universe must have begun a finite time ago.
If a car passes you on a street corner it does this because of the energy supplied by the petrol and a mechanism to convert that petrol to movement. But as the car passes you, you know two things (1) the energy supply is finite and (2) unless it is topped up, it's going to run out of petrol and the car will eventually stop!
Now if you know that the cars energy supply is finite, and that this energy supply is running out, then you know this car must have started its journey at a finite time in the past.... so, at the point at which the car reached you, the car cannot have been traveling for an infinite period of time. That would not be possible on a finite supply of energy: a tank full of petrol.
Likewise, the universe has a finite supply of petrol (gas) which is not being added to and therefore is running out. Because the universes supply of energy is finite and because it is running out, we can easily conclude there must have been a finite time in the past when the universe began it's journey.In the next sections you will see examples of entropy in the universe