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The fine-tuned universe

The words ‘fine tuning of the universe’ have been around for quite a while and are greeted with bafflement, scepticism and wonder; in about equal proportions. What on earth (or in the universe) does it mean? Theoretical physicist Paul Davies calls it The Goldilocks Enigma.[1] Is it real or just a cranky argument from some fundamentalist religious nutcases?

And even if there appear to be very precise conditions needed in the universe for life, is it not just what you would expect anyway? After all life is here! — So the conditions must have been right for it to have appeared, in order for it to be here. Is it all just a circular argument and nothing else? Then what about the idea of multiple universes with our one just happening to accidently have the right conditions? Does that not deal with the improbability problem? Is this not very human centred anyway; just another way of thinking we are special when we are not?

Schematic scenario of a big-bang expansion

I hope to unravel at least some of these ideas in this article. But we need to start with facts. The facts may seem somewhat abstruse to those with little science background but the details are not as important as the implications they lead us to contemplate.

The big bang is reckoned by most cosmologists to have occurred 13.7 billion years ago. It is simply not known what led to the big bang; there are many ideas out there. What we can do is apply the known laws of physics and run backwards in time to very close to that beginning. The universe must have started at a particular time because of the second law of thermodynamics. This, when applied to the present known universe, shows us that it is gradually heading for heat death, a maximising of its entropy. This is a process that is time limited and can be worked backwards. So there was a beginning. The microwave cosmic background radiation that surrounds us is strong confirmation of that beginning. It is like an afterglow of the stupendous event. The mounting evidence for the expansion of the universe, first noted by the astronomer Hubble, is very much part of the reason why we can apply known laws and determine both the time and the conditions of the earliest moments as we run the tape of time backwards. Space itself is expanding in every direction and there must have been some moment when it all started.

As physicists did their calculations to work out what were the actual conditions at the start, they began to uncover some very extraordinary facts. A few of these will be listed here. What these facts showed was that the conditions had to be extraordinarily precise for there to be a universe as we know it now, fit for life. Change these conditions very slightly and you do not get just a slightly different universe, you get a variety of possibilities but not one of them would allow life to occur and most would not even allow for galaxies, stars and planets.

Unevenness in the expanding energy

As the primordial universe grew, there needed to be a very slight unevenness in the expanding energy. If the energy had been entirely evenly distributed then there would be no coalescence of matter into galaxies; instead there would have been a homogenous and featureless universe. As a matter of fact the universe is fairly smooth, with very similar conditions and distributions of galaxies in every direction. Some of this smoothness is thought to be due to a short burst of what cosmologists call inflation, very close to the beginning. Inflation is when, after a split second, the universe is said to have suddenly jumped in size by an enormous factor of about 1025 (ten trillion trillion), after which it resumed its normal expansion rate. This inflation is thought to have stretched the initial irregularities away rather like an inflating balloon loses its wrinkles. However, there was still enough irregularity to allow for clumping into galaxies. The amplitude of these non-uniformities is described by a simple number, Q, which is the energy difference between the peaks and troughs in the density, expressed as a fraction of the total energy of the initial universe. Computer models show that Q had to be very close to 0.00001 in order for any galaxies to form. If it was minutely lower then no structures would have formed. If it was minutely higher then all matter would have collapsed into huge black holes. In other words Q had to be just right.

Matter vs. Anti-matter

At the beginning of the universe there was matter and anti-matter. If the amounts of each had been exactly the same then they would have cancelled each other out, leaving just energy in the form of photons. The Russian physicist Andrei Sakharov showed that matter and anti-matter are not precise mirror images of each other. There is a very slight asymmetry which favours matter over anti-matter. This difference is absolutely crucial and is only about one part in a billion. We, and all the rest of matter in the universe, only exist because of this one in a billion difference. As Martin Rees, former Astronomer Royal, writes in his book ‘Our Cosmic Habitat’, referring to this fact, “we owe our existence to a difference in the ninth decimal place.”[2]

Expansion Energy vs. Gravity

It was crucial for the expansion of the universe at the very first second of the big bang that the expansion energy (or impetus) was finely balanced with the gravitational force, which was pulling it all back together. If the expansion energy had been too big then galaxies and stars would never have been able to pull themselves together with gravity. If the expansion energy had been too small then there would have been a premature ‘big crunch’ as the universe imploded into itself. It has been mathematically calculated that, back at one second, the universe’s kinetic (expansion) energy and gravitational energies must have differed by less than one in 1015(one part in a million billion). If it was any different, in either direction, then there would be no galaxies, no stars, and no earth.

Ratio of nuclear forces

Physicists tell us that if the ratio of the nuclear strong force to the electromagnetic force had differed by 1 part in 1016, no stars would have formed.

Ratio of electromagnetic and gravitational forces

Also, the ratio of the electromagnetic force constant to the gravitational force constant must be precisely balanced. If you increase it by only 1 part in 1040 then only small stars will form. Decrease it by the same amount and only large stars will form. To have life there must be both large stars (to produce the elements) and small stars to burn long enough to sustain a planet with life.

To understand something of the kind of accuracy to achieve a 1 in 1040 chance of a certain state occurring it is helpful to illustrate this in various ways. Paul Davies writes that it is the kind of accuracy a marksman would need to hit a coin at the far side of the observable universe, twenty billion light years away.[3] Astrophysicist Hugh Ross gives another illustration:[4] cover America with coins in a column reaching to the moon (236,000 miles away), then do the same for a billion other continents of the same size. Paint one coin red and put it somewhere in one of the billion piles. Blindfold someone and ask them to pick it out. The odds are about 1 in 1040 that they will.

The odds of getting a low entropy start

Eclipsing even this, eminent mathematician Roger Penrose writes about the way in which the universe had to start with low entropy to have galaxies, stars and life. To have this state, and the resultant second law of thermodynamics, the ‘Creator’ had to aim for what is called a certain volume of ‘phase space’ This aim would have to have been accurate to 1 part in 10 to the power 10123. This is a number so large that the zeros far exceed the number of particles in the universe.[5] While we may not all understand what ‘phase space’ is, we can grasp the enormity of what he is saying here. The universe, to have a second law of thermodynamics and thus the possibility of sentient beings like ourselves, required extraordinarily special conditions at the big bang; special because the conditions, out of the endlessly other possible ones, simply had to be as they were.

Resonance energy of carbon

We can go on giving even more examples of how the universe, our solar system and our planet seem honed to the most precise states possible so that conditions exist for life to occur, and the last one I will mention is about carbon. We, and the rest of life, are made of carbon-based chemistry. The carbon that is in you and me was manufactured in some star prior to the formation of the solar system. We are literally made of star dust. Each carbon nucleus (six protons and six neutrons) is made from three nuclei of helium within stars. Astrophysicists Hoyle and Salpeter worked out that this process of forming carbon works only because of a strange feature: a mode of vibration or resonance with a very specific energy. If this was changed by more than 1% either way then there would be no carbon to make life. Hoyle confessed that it looked as if a ‘super intellect has monkeyed with physics as well as with chemistry and biology’ and that ‘there were no blind forces in nature worth talking about’.[6]

The physicist Freeman Dyson wrote: “I do not feel like an alien in this universe, the more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense must have known that we were coming.”[7] Is this just make-believe or is there really evidence here for a Creator? I will now look at some of the common objections to the idea of a designer of the universe.

Many will question that the universe is really finely tuned at all. Is what we see not just the way it is? After all, if we look at any system or group of objects we see highly unlikely complexity. If I pick up the all the pieces from a set of scrabble and throw them on the floor then the resultant order and position of the pieces is very unlikely; if I throw them again the chances of getting that particular assemblage again is astronomically small. There has been no design input and pure chance can account for the assemblage of pieces. I decide to leave the pieces scattered on the floor and have a cup of coffee. Coming back five minutes later I find that the pieces are still on the floor but some of them are arranged in a sentence. The sentence reads: “Dad is very messy and should not leave scrabble pieces on the floor”. There is no one in the room but I quickly decide that one of my children has actually arranged the pieces, by design, into that sentence. Whereas the first assemblage of pieces was very unlikely and due to chance, the second arrangement is also very unlikely but due to design. What is the difference? The difference is that the second arrangement is specified. It is specifically saying something in English. It has specified complexity. William Dembski the mathematician is one of the principle thinkers to elucidate this subject.[8] Many systems can undergo this same test, not least biological ones. In the case of the universe however we see very very specified complexity. The conditions at the beginning, spelled out, if you like, life being possible in the future. Nothing else would have done the trick.

Martin Rees, and others, have used the example of a firing squad to show that there really is something to marvel at when we see fine-tuning.[9] Imagine a man before a firing squad with 50 marksmen who fire at him. All of them miss. He opens his eyes and is allowed to walk away. He says to himself, “well, I am alive, so they must have missed! Nothing extraordinary about that.” His lack of wonder at the small chance of them missing is not at all unlike the sceptic who says there is nothing special about the fine-tuning of the universe.

Multiple universes?

Most cosmologists accept the fact that there is at least something to be explained about the fine tuning. They look to a way to reduce the incredible improbability of the specified conditions at the beginning. One way is to say that there are multiple universes, trillions times trillions of them in fact. So many, that in at least one of them we will find the unlikely conditions we have in our universe. By posing this possibility, the design argument is seemingly unnecessary. It allows science to regain control if you like of the situation. To many, the idea of a supernatural designer is simply too much to accept. After all, science is about the natural world and to speak these days of a designer is just outside the brief of cosmology.

There is no evidence, theoretical or experimental, for any universe other than our own. To pose the idea of multiple universes is because of a particular belief system (“there is no designer”) rather than about science. So in fact it is a step which is outside of science. This is not to say there could not be more universes; it is just that the idea of them is coming from outside any scientific knowledge. Multiple universes of course do not do away with a designer either. The problem with the idea will always be (unless actual evidence emerges) that it is proposed for unscientific reasons.

The idea that science cannot cope with a designer is very open to dispute, as is seen from the history of great scientists such as Newton, who did wonderful science while all the time firmly of the view that all he saw was designed. It is a peculiarly modern phenomenon to say we cannot speak of a designer. In the end it is much more reasonable to see design or not from the evidence, not from any prior views about the supernatural. Physicist Edward Harrison has written: “Take your choice: blind chance that requires multitudes of universes, or design that requires only one.”[10]

Is this man’s arrogance?

Is not the anthropic principle (the idea that the fine tuning leads to the appearance of life and mankind) very arrogant? Surely, since Copernicus showed that the earth is not the centre of the universe, we can avoid any such ego-centric nonsense! This is a sort of gut reaction many give to this idea of fine tuning. It is an admirably humble way of seeing our insignificance in the scheme of things. Many would add that evolution shows man to be just one of the many life forms and that there has been no actual purpose or teleology in our appearance.

The problem with this idea of man’s insignificance is that it has been made into a sort of law by many. There can be no deviation from it. Yet the Copernican astronomy had nothing to do with fine tuning. It was about the place of the earth within the solar system and beyond. The subject matter is entirely different. To make a blanket law from it seems excessive, to put it mildly. It is also important to note that the anthropic principle does not actually refer to mankind specifically. It refers to the appearance of any life at all. It is not in this sense man-centred. In the end, particular world views about our significance or lack of it, must bow to the simple facts of the precision tuning we find. We need to step out of our prejudices, including any religious ones we might have, and see this objectively. Does the evidence point to design or not?

God of the gaps?

John Lennox, Professor of Mathematics and Philosophy of Science at Green Templeton College, Oxford, has written much in support of the design arguments from fine tuning. He writes concerning these arguments: “We should note that the preceding arguments are not ‘God of the gaps’ arguments; it is advance in science, not ignorance of science, that has revealed this fine-tuning to us. In that sense there is no ‘gap’ in the science, The question is rather: how should we interpret the science? In what direction is it pointing?”[11]

His conclusion is that science overwhelmingly provides evidence for a designer of the universe.



[1] Davies, Paul. 2006. The Goldilocks Enigma. Penguin

[2] Rees, Martin 2002. Our Cosmic Habitat. London: Weidenfeld & Nicolson.

[3] Davies, Paul. 1983. God and the New Physics. London, J M Dent & Sons.

[4] Ross, Hugh. 1995. The Creator and the Cosmos. Colorado Springs, Navpress.

[5] Penrose, Roger. 1989. The Emperor’s New Mind. Oxford University Press. P. 344

[6] Hoyle, F. 1982. Annual Reviews of Astronomy and Astrophysics, 20. P. 16

[7] Dyson, F. 1979. Disturbing the Universe. Harper and Rowe, New York

[8] Dembski, W.A. 1998. The Design Inference. Cambridge University Press.

[9] Rees, Martin. Just Six Numbers.

[10] Harrison, E. 1985. Masks of the Universe. New York: Collier Books, Macmillan.

[11] Lennox, John. 2007. God’s Undertaker. Has Science Buried God? Lion Hudson.

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Antony Latham, 24/12/2016