Chapter Five

Cosmology and the unexpected return of design

In chapters two and three, we discussed how the idea of natural selection supports the idea that life on earth is undesigned i.e. that there is no meaning or purpose or intelligence behind it. Spending so much time talking about the meaninglessness of life may have given you the impression that I am, as P G Woodhouse put it, not the kind of person who is likely to mistaken for a ray of sunshine. If so, hopefully this chapter will give you a quite different impression. Natural selection could, plausibly, explain how the evolution of life on earth occurred, starting from (relatively) simple life forms, and eventually leading to the great variety of life that we see today. How the simple, or rather the not so simple, life forms came about in the first place remains unknown, and possibly unknowable. I am not saying: ‘We don’t know how that happened, therefore God did it’.  I’m saying: ‘we don’t know how that happened.’

But, when it comes to the story of how the galaxies and the stars, the planets, the sun and the earth and the moon, and the 92 chemical elements of which they are made all came about, we know a great deal about how that happened. However life on earth began, it could not have begun without the earth and sun or, many scientists would argue, without the moon. It certainly could not have begun without the elements. Without them there would be nothing to make life with. The story of life begins, then, with the story of the universe. This wider story shows that although the idea of design may have left the stage when Darwin came along, with modern Big Bang cosmology, it has made an unexpected but triumphant return!

The main subject of this chapter is cosmological fine tuning. If you want to delve more deeply into the subject of fine tuning I have three recommendations for you: Just Six Numbers by Astronomer Royal Martin Rees, The Goldilocks Enigma by physicist and writer Paul Davies, and A Fine Tuned Universe by Alister McGrath. There are more than six numbers to consider. Rees combines various numbers together for reasons which he explains in the book. Rees calls them cosmic numbers, so I shall do likewise. The Goldilocks Enigma is the fact that these numbers are just right, like Goldilocks’ porridge in the traditional story. Rees is an atheist who is sympathetic to Christianity, at least in its cultural aspects. Davies has interesting views on faith, but he is not a religious believer in any conventional way. Neither has any theological axe to grind; they just discuss the physics. McGrath is a Christian theologian and also a biologist, and so he gives contrasting perspectives in two different ways. Before we can see the significance of these cosmic numbers we need some background knowledge in cosmology.

 

What is the Big Bang Theory?

Cosmology is the study of the universe as a whole: it’s origin, its history and its possible futures. In this book, by universe, I mean the observable universe, the universe where we live, and which we can observe, measure and test; the universe which can therefore be studied by science. Cosmology uses the full spectrum of ideas from physics, combining together nuclear physics, quantum mechanics, thermodynamics, and so on; but the theory which underlies it all is Einstein’s theory of gravitation, usually called general relativity, since gravity is the force that dominates the history of the universe.

The Big Bang theory is the modern scientific story of the universe. We might call it Life: the Prequel. The Bible story begins with the words: ‘in the beginning …’ The Big Bang story begins: ‘very shortly after the beginning …’ If you feel tempted to connect those two statements together, that’s one temptation you don’t need to resist too hard. Very shortly after the beginning, all the matter in the universe was in a hot, dense state. The universe expanded and as it did so it cooled, became less dense. Matter eventually condensed, under the influence of gravity, into stars which, once again under the influence of gravity, were collected together into galaxies. At this point in the history of the universe, most of the matter in the universe consisted of the two lightest chemical elements: hydrogen and helium. Atoms of the elements consist of a very small dense central nucleus made up of two types of particles: protons and neutrons. The nucleus is orbited by lighter particles called electrons. This is not unlike the way in which planets orbit the sun. Copernicus again. The number of protons in the nucleus determines which element you have. In the centre of a star, matter is in a hot, dense state, although not as hot and dense as the universe shortly after the beginning. Under these conditions, a series of nuclear fusions takes place in which lighter nuclei merge together to make heavier ones, that is ones with more protons. Since the new nuclei have more protons, they are now the nuclei of different elements. This is the process which creates the nuclei of most of the familiar chemical elements, starting from hydrogen and helium. The bigger and hotter the star, the more elements can be made. Some stars, the bigger hotter ones, end their lives in a tremendous explosion called a supernova. During the supernova, nuclei of the remainder of the elements are made. The elements are thus spread into space. The matter left over from the supernova can, under the influence of gravity, form a new generation of stars; but this time the heavier elements are involved: carbon, nitrogen, oxygen the basic building blocks of life, iron, and also silicon from which rock is made; and all the rest. Around this second generation of stars, planets and moons which are made of iron and silicon and all the rest could form. Thus did our moon, our sun, and our earth, with its potential for life, come to be (Jones and Lambourne, 213 – 304). And so here we find ourselves 13,800,000,000 years after the beginning wondering how we got here and why we are here. A priest who worked as the chaplain of a mental hospital once began his Sunday sermon with the rhetorical question: ‘Why are we all here?’ One of the congregation replied, ‘because we are not all there.’ He didn’t try that opening again.

The Big Bang theory was given its name by cosmologist Fred Hoyle, one of science’s truly larger than life characters. He once wrote: ‘Space isn’t remote at all. It’s only an hour’s drive away if your car could go straight upwards.’ Hoyle did not believe in the Big Bang theory; the name he gave it was supposed to be taking the mick, but it stuck anyway.

Hoyle was an enthusiastic atheist but changed his mind because of the discovery of cosmological fine tuning, which is a striking feature of modern cosmology, and which is the principal theme of this chapter. In fact, Hoyle discovered the first known example of cosmological fine tuning in the 1950s; the ‘coincidence’ in the laws of physics that leads to the creation of the nuclei of the element carbon inside stars whose unique properties are essential to the creation of life. The creation of carbon is also an essential link in the chain of nuclear fusions that creates of most the other elements which are also essential to life (Davies, 153 – 158). Eventually, Hoyle came to the conclusion that this coincidence was not a coincidence.

As Hoyle puts it:

A common sense interpretation of the facts suggests that a super intellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature (McGrath, 134).

He didn’t become a Christian and did not believe in God per se, but this is an example of how a scientific discovery presents a challenge to atheism not Christianity. According to some people’s view of the relationship between science and Christianity, that’s not supposed to happen – but it did. We will discuss this coincidence some more later on in the chapter.

 

The history of the Big Bang theory

The story of the theory itself begins in 1905, Einstein’s ‘annus mirabilis’ in which he published no fewer than four foundational scientific papers. One of them was on the photoelectric effect, a key step in the development of quantum mechanics, for which he won the Nobel prize in 1921. Two of the other papers established what became known as the theory of special relativity. The other paper explained the mathematics of Brownian motion and finally banished any lingering doubt about the existence of atoms. Of course, you can’t trust atoms. They make up everything. In 1915 he published papers on his general theory of relativity which extended special relativity to include the force of gravity. Central to this theory is a set of ten equations known as the Einstein field equations. Einstein produced an approximate solution to these, which was enough to account for the strange orbit of the planet Mercury, which Newton’s Laws of motion could not explain. This was the first confirmation that the theory was correct. He was immensely relieved to discover that his work on the theory up to that point had not been in vain. The first exact solution to the equations was not produced not by Einstein but by Karl Schwarzschild who was serving with the German Army on the Eastern front at the time. Not the ideal situation for doing maths you would have thought but that didn’t stop him. It’s not a complete solution, but it can be applied to objects which are spherical and there are quite a lot of those in space. The solution tells us, amongst other things, about the mathematics of black holes. Schwarzschild gives his name to the Schwarzschild radius which tells you where to find the ‘event horizon’ of a black hole. Unfortunately, he died the following year in 1916. Still, he outsmarted arguably the smartest man who ever lived, and got the event horizon of a black hole named after himself which has got to be one of the coolest things ever if you’re a nerdy kind of person, so he went out in a blaze of glory.

The next confirmation came from measurements carried out by British scientist Arthur Eddington during an eclipse of the sun on 29^th May 1919, which he observed from the island of Principe, an island in the Gulf of Guinea off the coast of West Africa. The theory predicted that a ray of light from a star passing close to the surface of the sun would be bent because of the curvature of space in the sun’s powerful gravitational field. This means that the star will appear to have moved from the position you expect it to be in. This is like the effect you see when you look at an object at the bottom of a swimming pool. It appears to be closer to the surface than it actually is. This is because rays of light from the object are bent as they pass out of the water and into the air. By measuring the difference between the known true position of the star and the position it appeared to be in as observed from earth, the precise predictions of the theory could be tested. The eclipse provided the opportunity to make the measurements which would normally be impossible due to the brightness of the sun. The observations confirmed the theory and general relativity was truly in business! (Jones and Lambourne, 221; 237)

It was Eddington who was responsible for making General Relativity famous in the English speaking world. Someone once asked him, ‘Professor Eddington, it is said that you are one of only three people in the world that truly understand Relativity Theory. Is that true?’ Eddington hesitated. ‘Oh, I’m sorry Professor. Modesty forbids.’ ‘Oh no,’ replied Eddington. ‘I was just wondering who the third one was.’

Eddington was, like many pioneers of science, a man of profound Christian faith.

The next solution to Einstein’s field equations was produced independently by two people: Alexander Friedmann and Georges Lemaître. The solution is another set of equations, called the Friedmann-Lemaître or FL equations, sensibly enough. These apply Einstein’s field equations to the universe as whole. They are based on the cosmological principle, that is the idea that space is homogenous, the same everywhere and everywhen, and isotropic, the same in every direction. On a large enough scale, such as the scale of the whole universe for example, observations show this is pretty much true. Like Schwarzschild, Friedmann died relatively young in 1925 and did not live to see how significant his equations proved to be. Friedmann was a mathematician not an astronomer. Lemaître was an engineer, artillery officer, computing pioneer, mathematician, astrophysicist and, as it happens, catholic priest. Lemaître did which Friedmann was not able to do, which was to make connections between different aspects of the problem and thus create what became the Big Bang theory. He was the first person to propose that the present universe evolved from a highly dense beginning which is why he is known as the father of the theory (Carroll and Ostlie, 1190). Two things in particular which he connected together were: a) the fact that the field equations predict that the universe is expanding and b) the evidence from astronomical observations that the distant galaxies are receding away from the earth. (Jones and Lambourne, 233, 237; IAU, ‘On a suggested renaming of the Hubble Law’)

Einstein obviously realised that his theory predicted that the universe was expanding (or contracting) but he did not like the idea. His comment to Lemaître was: ‘Vos calculs sont corrects, mais votre physique est abominable.’ Even if you don’t speak French, I don’t think that needs translation! Einstein added a number, ‘the cosmological constant’, to his equations to make the ‘problem’ of the expanding universe go away. Later, he described this as his ‘biggest blunder’ and he took the number out. This addition of this number was a contrived, ad hoc modification to a theory and we know all that’s a bad thing, don’t we? See principles 2 and 3 in the prologue. Einstein called it ugly.  Ironically, it turned that it wasn’t a mistake at all and the cosmological constant was put it back in. Nowadays, it’s central to cosmology. Ah, well. It’s a funny old universe. The expansion is still there though, with or without the ‘biggest blunder’ (Jones and Lambourne, 228-229).

 

Why believe the Big Bang theory: what is the evidence for it?

1. The universe is expanding. This is predicted by Einstein’s theory – and Einstein’s theory is strongly supported by evidence as we have seen. We already mentioned that there was evidence in 1927 when Lemaître published his paper on the Big Bang that the distant galaxies are receding away from the earth as you would expect if the universe is expanding. To illustrate how this this can be known, we can go back the example of travelling in a car which we used to illustrate stellar parallax in the prologue. This time, though, you are standing on the side of the road watching someone else travelling in a car. You will have noticed that as a car goes past, the sound which it makes drops in pitch. The effect is more noticeable when the car is a police car or ambulance with its siren going. Sound travels as a wave. As the car approaches you the wave is squashed and the pitch of the sound goes up. As the car moves away from you the wave is stretched and the pitch of the sound goes down - hence the change in pitch which you hear. This change in pitch is called the Doppler Shift. The faster the car goes the bigger the effect. In fact, you can tell how fast the car is going by measuring the pitch of the sound. The police radar gun which they use to check if you are speeding works on the same principle except that in this case it’s radar waves fired from the gun that are bouncing off your car and giving the game away rather than sound waves.

Something similar happens to the light coming from distant galaxies since light also travels as a wave. The galaxies are receding from the earth and so the light from them is stretched. When a sound wave is stretched the pitch of the sound is lowered. When a light wave is stretched its colour changes – it becomes closer to red, so this effect is called red shift. The red shift in the light from the galaxies is called cosmological red shift. This cosmological red shift is not strictly speaking the Doppler Effect although it is similar. The stretching of the wave is down to the stretching of space in between the galaxies. You can illustrate what is happening by drawing a wave on a rubber balloon and then inflating the balloon. As the balloon inflates, it’s surface expands, and therefore so does the length of the wave; it is stretched. Most physics students have done this at some point. All of my students have certainly. And yes, all of them then release the balloon afterwards and watch the balloon fly across the classroom making that noise that they all find so amusing for some reason. It’s as predictable as the … orbit of Mercury. Kids will be kids, even when they are eighteen. The amount of red shift in the light coming from a galaxy tells you how fast it is receding from the earth. More red shift = faster speed of recession. As it turns out, the amount of red shift and therefore the speed of the galaxy is proportional to the distance of the galaxy from the earth. This was confirmed by observations made by Edwin Hubble published in 1929 and so this proportionality is known as Hubble’s Law. In 2018 however, the International Astronomical Union recommended that the name should be changed to the Hubble-Lemaitre Law to honour both men’s contribution. (IAU, ‘On a suggested renaming of the Hubble Law’)

Imagine that all the galaxies, including our own, started in the same place and then the others ‘exploded’ outwards from our galaxy. The faster moving galaxies would now be further away from us that the slower moving ones. In fact, a galaxy moving at twice the speed of another would be twice as far away and so on. But that is what we see and precisely what is described by Hubble’s law – speed and distance are proportional. You can see how Hubble’s law leads to the idea of the Big Bang! It looks distinctly like universe started from a single point, which Lemaître referred to as the primaeval atom or cosmic egg, and it expanded from there.

This doesn’t mean the earth is the centre of the universe by the way. An alien in another far away galaxy would see exactly the same thing. It also doesn’t mean that the universe is expanding into an empty space that was already there. There is no ‘space’ outside the universe. It is space itself which is expanding.

2. The proportions of the elements. The visible matter in the universe is 75% hydrogen, the lightest element; 23% helium, the second lightest; and 2% other heavier elements. This is what the Big Bang theory predicts. Theories which can correctly predict things are good theories. See principle 4 from the prologue.
3. The Cosmic Microwave Background or CMB. This was predicted in the 1930s and discovered by Penzias and Wilson in 1964 almost by accident. Whilst studying something else entirely, they found that coming from every direction in space there is a constant background microwave signal which is the same (almost) no matter which direction you look in. Of course, these sorts of discoveries aren’t really accidents, even if they do involve a stroke of luck. Penzias and Wilson’s real achievement was to realise the significance of their discovery through their communications with other physicists. They won the Nobel prize for this in 1978. Microwaves travel as waves. You probably guessed that. Light waves and microwaves are the same type of wave – they are electromagnetic waves i.e. electromagnetic radiation. The difference is that the light waves are much shorter.

When the universe was about 380,000 years old, a critical event in its history occurred. As we noted earlier, atoms of the elements consist of a very small dense central nucleus orbited by lighter electrically charged particles called electrons. This is not unlike the way in which planets orbit the sun. Before this time, when the temperature of the universe was extremely high, the electrons had too much energy to be bound in orbit around a nucleus. They were free electrons. They were able to interact with electromagnetic waves which then filled space. After this time the universe had expanded and cooled enough for electrons became bound to nuclei, thus forming atoms, and they were no longer free to interact. Thus, matter became ‘decoupled’ from radiation. From this time on, matter and radiation each went their own separate ways. The light waves from this time have now been red shifted, stretched, by the expansion of space so that they have become microwaves. This is the CMB detected by Penzias and Wilson. The CMB is a kind of snapshot of the universe when it was 380,000 years old and it contains vast amounts of information about the history of the universe.

Satellites such as the Cosmic Background Explorer (COBE) satellite that orbited in 1989–1996, and the Wilkinson Microwave Anisotropy Probe (WMAP), operating from 2001 to 2010 have made precise measurements of the CMB. People used to joke that there is speculation, speculation squared and then there is cosmology. There was some truth in that before the discovery of the CMB; but now thanks to thanks to COBE, WMAP and more recent even more precise measurements, we have entered the age of precision cosmology. We now have very reliable evidence on which to base our theories about the history of the universe (Jones and Lambourne, 307 – 343).

 

What is cosmological fine tuning?

At last, we are in a position to talk about cosmological fine tuning.

There are certain numbers, constants, which characterise the laws of physics and the universe that those laws describe. There are around 20 - 30 of these numbers, depending on how you count them. These concern the strengths of the various forces of physics: the force of gravity, the electromagnetic force, the two nuclear forces, the strong and the weak; also the density of the universe and the number of dimensions of space - there are three, but you knew that - and of course Einstein’s ‘greatest blunder’, the cosmological constant. One of these numbers is big gee: G. No, not THE big G i.e. God. Big gee in this case is Newton’s constant. We will use G to illustrate what these numbers do. G appears in Newton’s law of gravitation. The equations in Einstein’s theory of gravitation are much more complicated than the one in Newton’s theory, but G still appears in them. If you don’t like equations, please feel to ignore this one. Understanding it is useful, but not essential.

F =  G x M x m                                                                                                            

           R x R

This is Newton’s Law of Gravity. F is the force of attraction between two objects due to gravity, M is the mass of the larger object, m is the mass of the smaller object and R is the distance between them. The role of G in the equation is to tell you how strong or weak the force of gravity is. The bigger G is, the bigger the force is between the two objects or indeed any two objects. All the other numbers in the equation change depending on the situation, but G is always the same; it is a constant. The other constants play similar roles in the other equations which describe the laws of physics, but one equation is enough to illustrate the idea!

There are two important things to notice about G and all the other constants. Firstly, they are the same everywhere and everywhen. How do we know that they are the same everywhere and everywhen? We don’t. As we noted in the prologue, science is based on the belief that there is a rational, intelligible, reliable order underlying the universe. Believing that these constants really are constants everywhere is part of this belief (unless and until evidence shows otherwise of course). As we also noted in the prologue, our experience so far indicates that this is a justified belief. Secondly, there is no law of physics, and no law of logic which tells us what these constants should be. They just are what they are, as far as we know (Davies, 88). Consequently, the only way of knowing what they are, is to measure them.

The precise value of G is of immense importance in the history of the universe as described by the Big Bang theory. It is G which sets the scale of things in the universe, the size of galaxies, stars, planets, even the size of human beings (Rees, 29-35). It also determines how long stars last and how hot they burn. In fact, G determines whether or not galaxies, stars, planets and therefore human beings come into being at all. It turns out that our existence depends on G having more or less precisely the value that it does. How do we know that?

We can use general relativity, and the other equations of physics containing the constants, aided and abetted by the ‘unreasonable effectiveness of mathematics’, to work out what would have happened if G or any of the other numbers had been different. We can try out any number of alternative scenarios for the history of the universe with different values of the constants. This is how we know that if any of these numbers were even a little different, the history of the universe would have been completely different from the actual history described above (Davies, 147-170, McGrath 92-93).

In one scenario, the universe expands then contracts back into a single point - a big crunch. In this universe there would be no time for life to evolve and we would not exist. In another scenario, the universe expands so fast that the galaxies, stars and planets never form. In a universe like this we, obviously, would not exist. In yet another scenario, there are no chemical elements created other than the lightest ones. This is down to the ‘coincidence’ first noticed by Fred Hoyle. It has to do with the relative strength of the electromagnetic and strong nuclear forces as described by our cosmic numbers. It is only because they have rather precisely the values that they do in our universe, that the element carbon, essential to life, and also to the creation of most of the other elements, can be made by nuclear fusion inside stars. In a universe like the one in this alternative scenario, we would not exist since we are made out of the chemical elements.

The way in which Hoyle discovered his coincidence is interesting. In fact, I would go as far as to say it’s rather entertaining! Hoyle reasoned thusly. We exist. Therefore, it is possible for us to exist. You can’t fault his logic there! Since we cannot exist without the element carbon it must therefore be possible for nuclei of the element carbon to be created by nuclear fusion inside stars, since that is how nuclei are created. This is only possible if a certain ‘resonance’ exists within the carbon nucleus. Thus, concluded Hoyle, this resonance must exist. He persuaded scientists at Caltech in the US to test his idea and - lo and behold – there was the resonance, just as Hoyle predicted (Davies, 156).

It turns out that our existence depends on all the other constants having more or less precisely the value that they do, it’s not just G. This is what is meant by cosmological fine tuning. All the cosmic numbers, the fundamental constants of physics, appear to be ‘fine-tuned’ to precisely the values they need have in order for us to exist.

Some have tried to calculate the probability of this fine tuning happening by chance. I don’t think it’s possible to come up with a precise figure, we just don’t know enough for that; but we can get an idea, and it’s safe to say the probability is inconceivably small. Our existence appears, on the basis of cosmological fine tuning, to be not just a stroke of luck, more like a miracle.

As physicist Freeman Dyson put it, ‘The more I examine the universe and study the details of its architecture, the more evidence I find that the universe in some sense knew we were coming.’ (McGrath, p120)

McGrath describes how this fine tuning is important in biology and in evolution. Evolution depends on the properties of the chemical elements, and these in turn depend on our cosmic numbers.

As McGrath puts it, chemical constraints shape evolution: the key processes are possible only because specific metals, allow them to occur. Without this, he says, evolution wouldn’t have arrived at solutions like photosynthesis, nitrogen fixation, or oxygen transport. Evolution can only fine tune itself because of the predetermined properties of the chemical elements. If those properties had been significantly different, such fine-tuning wouldn’t be possible (McGrath, 164).

The chemical properties of carbon are especially important. He says:

It is clear that a capacity to encode information is of decisive importance for evolution in general and evolvability in particular. And that, as we have seen, is critically dependent upon the organic chemistry of carbon which permits the formation of long, stable chains. No other element has this property; without out it, RNA and DNA would be impossibilities, as would the replicative processes they control. The capacity of evolution to fine tune itself is thus ultimately dependent on fundamental chemical properties which in themselves can thus be argued to represent a case of robust and fruitful fine tuning (McGrath, 180 -181).

Perhaps evolution by natural selection would still be possible if carbon and the other chemical elements had different properties. Well, perhaps, but as McGrath remarks:

There is an implicit assumption that life would adapt to whatever hand of physical and chemical cards were dealt to it. Yet this is untested and intrinsically questionable (McGrath, 180).

The understatement of all time?

 

Does this mean that the universe is designed?

I find that fact that anything at all exists astounding. Why isn’t there just nothing? I find the fact that the universe that does exist is governed by a rational order even more astounding. Why isn’t there just uniform chaos? Recall the principles I listed in the prologue. We expect to find simplicity in the universe and an absence of contrivance. There is nothing more simple than pure nothing; there’s nothing Heath Robinson about … nothing. There’s no need to explain nothing. If the universe consisted of some sort of uniform chaos that would require some sort of explanation, if only to explain why there is something rather than nothing. OK, so if there was just uniform chaos, there would be no one there to do that explaining – fair point – but let’s carry on. Uniform chaos would still be very simple and uncontrived, much more so that the universe we actually observe. The fact that the universe exists, that it is not maximally simple, and is governed by a rational, reliable, intelligible order is, in my view at least, even more astonishing that the fine tuning of the cosmic numbers that we have been discussing; and these other things are surely much more theologically significant. So why focus on the fine tuning of the cosmic numbers rather than these other things? This is like listening to a concerto played on a particularly magnificent Stradivarius violin, and then remarking on how well tuned the violin was. Focussing on the tuning of the violin, rather than the violin itself, or indeed the violinist’s performance of the concerto, is rather missing the point!

However, the cosmic numbers have a useful feature that the other things do not. There is no way of calculating how likely or unlikely it is that something exists rather than nothing, or how likely or unlikely it is that there is a rational order rather than pure chaos. We have no way of assessing how surprising these things are. We wouldn’t even know how to start calculating a probability in the way that we could calculate the probability of winning the lottery, or pulling four aces out of a pack of cards. We are really just stuck with astonishment. But the cosmic numbers are numbers, and so we can do maths with them; so, we stand a chance of actually quantifying how astonishing it is that the cosmic numbers are fine tuned for life. I’m not sure what the word is to describe how astonishing this is – perhaps flabbergasting. If you can think of a better word, let me know.

The fine tuning of the numbers makes it look like the universe was designed for the purpose of creating life, but we have learned from the case of William Paley’s watchmaker argument, described in chapter four, to be cautious. Perhaps it only appears to be designed. Is there another way this fine tuning could have come about?

Rees says that there are three main candidates: coincidence, providence or multiverse (Rees, 164-179); Davies explores some more exotic possibilities throughout his book summarising at the end (Davies, 295-303); but let’s stick with the three. Rees favours the multiverse, Davies doesn’t really favour any of them, and McGrath, you will not be surprised to learn, prefers providence.

1. The multiverse. So far, we have used the word universe to mean the observable universe; the universe where we live, and which we can observe, measure and test; the universe which can therefore be studied by science. But perhaps, this universe is not all that exists. Perhaps it is part of something larger. Our universe had a beginning, but perhaps this larger universe is eternal; perhaps it did not come into being. Perhaps this larger universe is able to create baby universes like ours; perhaps extremely large numbers of them. Perhaps each of these baby universes has the same laws of physics as our observable universe, but values of the cosmic numbers which vary randomly. The vast majority of these universes would not contain life because they would not be fine-tuned. Very few would contain beings such as ourselves. But, of course, if all this were so, we would be living in one of the baby universes which is fine-tuned because we couldn’t exist in a universe that wasn’t. If all this were so, then his would explain why the cosmic numbers in our universe are fine tuned for life. We are the winners in a cosmic lottery. It is very unlikely that any particular individual will win the lottery, but is likely that someone will. Almost all baby universes are losers, but we live in one of the winners.

Problem solved then! All is explained. Well, perhaps, and perhaps not.

There are some ideas in physics which might explain how a multiverse with the properties above might work, for example string theory or eternal inflation, but they are speculative and untested (McGrath 124, Rees 166, Davies 298). If the multiverse idea is testable at all, this is not obvious. It is certainly not falsifiable, that is to say, if someone wants to claim that other universes exist which are invisible and completely undetectable there is nothing you can do to prove that they don’t. This means that the multiverse is not a scientific theory. Does this mean that believing in other universes is like believing in fairies at the bottom of the garden? I think that would be overstating the case! Perhaps there is a partial way around the unfalsifiability problem if we can rely on the unreasonable effectiveness of mathematics; after all that is what we did when we claimed that we can work out what the universe would have been like if the cosmic numbers were different, which is quite a claim. General relativity is a mathematical theory which is supported by an impressive body of empirical evidence. It also has a track record of correctly predicting things, as we have noted: the orbit of mercury, the bending of light rays, the expansion of the universe, the existence of black holes, and most recently gravitational waves. If physicists came up with a multiverse theory which was similarly well supported by observation and experiment and which made successful predictions about this universe which could be tested, and which also predicted the existence other universes with the required properties, then perhaps we would have reason to believe in the multiverse in spite of there being no direct evidence.

But even if there were such a theory, it wouldn’t really explain fine tuning; it would just exchange one kind of fine tuning with another. If the multiverse were a giant universe making machine with just the right properties to create life giving universes like ours, then it would have the appearance of being a machine designed for the purpose of creating life, albeit in a rather profligate way. As it happens, there is no such theory, which leaves the multiverse idea at least for the moment looking like a rather convenient way of avoiding a creator of the universe for those who find that idea alarming, distasteful or irritating; perhaps a bit too convenient.

2. Coincidence. Does this mean coincidence as in dumb luck? Actually, this scenario would involve the fulfilment of an age-old dream of physicists - but with one unexpected fly in the ointment - a rather big one. We have been following the story of the dream so far in this book, starting with Ptolemy and proceeding though Copernicus, Galileo, Kepler, Newton, Maxwell, Einstein to the present day. The dream is to one day discover a set of laws, expressed as mathematical equations, which would give us a complete explanation of this universe, the observable one, the one we live in, without anything as messy, frustrating and annoying as a multiverse. In the dreams of physicists, such a theory would be so simple and so elegant that the full set of equations could be printed on T shirt. We would all be very happy with that. But some go further, and hope that once we had such a theory, we would see why things are the way they are, and we would see that they could not be any other way. Such a theory would tell us why the cosmic numbers have the values that they do and show that they could not be otherwise. It would show that they were necessary not contingent. The fly? According to fine tuning, the way things must logically be would then just happen to be the way they need to be to for us to exist. Our existence then would be, yes, dumb luck.
3. Providence. For me, the most striking thing about fine tuning is the fact that its discovery it came as a complete surprise. Once again as McGrath put it:

There is an implicit assumption that life would adapt to whatever hand of physical and chemical cards were dealt to it. Yet this is untested and intrinsically questionable (McGrath, 180).

In other words, scientists in the past tended to take the way the universe is for granted, and assume that there was nothing to explain. It was just the background to the story of life. No one can make that assumption now.

Cosmological fine tuning does not prove that the universe is designed by God for the purpose of creating life. There are other possible explanations. It does however prove that the belief that that the universe is designed by God for the purpose of creating life is rational, and is not contradicted by the findings of science. As a matter of fact, it sits rather comfortably with the findings of science.

Furthermore, perhaps all this at last provides a possible answer to the question posed in chapter four: when should we assume that something puzzling in the universe has a natural explanation and when should we attribute it to design? Is this a false dichotomy? Perhaps both types of explanation are true. Perhaps what we are now seeing is that everything in the universe makes sense, but that sense points beyond itself to something greater. Everything in the universe has a natural explanation, which is complete as a natural explanation, but which leaves unanswered questions. As someone once put it, science answers all our questions except the ones that matter. Maybe so, but perhaps science helps us to ask the questions that matter. Could it be that everything in the universe has a natural explanation but is also designed, that is to say, there are not many designs but one? Is there is one God and one design, the universal design, revealed by science?

Summary

Cosmology is the study of the universe as a whole: it’s origin, its history and its possible futures. In this book, by universe, I mean the observable universe, the universe where we live, and which we can observe, measure and test; the universe which can therefore be studied by science. The framework for modern cosmology is provided by the Big Bang theory which is the modern scientific story of the universe.

If natural selection gives us a reason to believe that life on earth is undesigned, purposeless and meaningless, then cosmology, and in particular cosmological fine tuning, gives us a reason to believe the opposite. All the cosmic numbers, the fundamental constants of physics, appear to be ‘fine-tuned’ to precisely the values they need have in order for us to exist. This is an example of how a scientific discovery presents a challenge to atheism not Christianity. According to some people’s view of the relationship between science and Christianity, that’s not supposed to happen – but it did.

Cosmological fine tuning does not prove that the universe is designed by God for the purpose of creating life. There are other possible explanations for it. There are three main candidates: coincidence, providence or multiverse.

It does however prove that the belief that that the universe is designed by God for the purpose of creating life is rational, and is not contradicted by the findings of science. As a matter of fact, it sits rather comfortably with the findings of science.

 

Works Cited

Carroll, Bradley, and Dale Ostlie. An Introduction to Modern Astrophysics. 2^nd ed., Cambridge University Press, 2017.

Davies, Paul. The Goldilocks Enigma. Penguin Books, 2007.

International Astronomical Union. ‘On a suggested renaming of the Hubble Law’, 30th General Assembly, Resolution B4, 2018. https://www.iau.org/static/archives/announcements/pdf/ann18048a.pdf accessed 27 May 2024.

McGrath, Alister. A Fine Tuned Universe: The Quest for God in Science and Theology. Westminster John Knox Press, 2009.

Rees, Martin. Just Six Numbers. Weidenfeld & Nicolson, paperback ed., 2015.

Jones, Mark H, and Robert J. Lambourne, editors. An introduction to Galaxies and Cosmology. Cambridge University Press, 2004.