“Wherever physicists look, they see examples of fine‑tuning.”
— Sir Martin Rees (See here.)
“Imagine a puddle waking up one morning and thinking, ‘This is an interesting world I find myself in — an interesting hole I find myself in — fits me rather neatly, doesn’t it? It must have been made to have me in it!’”
— Douglas Adams (See here.)
The English physicist and writer Paul Davies (in his book The Cosmic Blueprint) wrote that the
“universe looks as if it is unfolding according to some plan or blueprint”.
The problem here is that if the laws and initial conditions determine the constraints and limits of everything that occurs in the universe, then they could well be seen as the cosmic blueprint… Thus, this effectively means that every physicist believes in the cosmic blueprint! Of course, plans are devised by human minds or by God’s mind. This is the additional part of the package which most physicists do not accept.
So physicists do often sound like believers in Intelligent Design when discussing fine-tuning. However, they state: “Our theory is incomplete.” More relevantly, they don’t talk about choice or purpose.
God has just been mentioned
One point that Paul Davies repeatedly makes is that unlike the argument of Creationists, Intelligent Designers and others who say that God must have designed the fantastic complexity and structural fit of the world, he believes that much of this can be explained without even mentioning the Judeo-Christian God. Instead, it’s the laws and initial conditions themselves which need to be explained.
First Class and Second Class Fine-Tunings
First Class Fine-Tunings:
fundamental constants, particle masses, couplings, the cosmological constant, dimensionality, initial conditions, etc.
Davies often asks: What of the initial conditions or laws themselves? He answers in the following way:
“We must either accept them as truly amazing brute facts, or seek a deeper explanation.”
Needless to say, Davies doesn’t accept them as being brute facts. He attempts to offer a deeper explanation of them. (Davies’s use of the term “brute fact” can be questioned here.)
Second Class Fine-Tunings:
Galaxy formation, star lifetimes, chemistry, planets, biochemistry, etc.
The claim here isn’t that the second class of “fine-tunings” are arbitrary or irrelevant outcomes of the first class. The second class is, however, constrained by the first class. Small changes in the first class can have big consequences when it comes to the second class.
So why the interest, and even concentration upon, the second class of “fine-tunings” by so many people? Such people emphasise the “improbabilities” which occur in the second class. But they’re to be expected. Improbable things happen all the time in large, contingent systems.
More relevantly, if something is highly improbable, then that doesn’t mean it is fine-tuned.
Let’s now focus on a second-class “fine-tuning” that’s become a favourite.
Fred Hoyle clearly recognised that the carbon resonance looked highly specific. His own phrasing was that it seems to be a “a put-up job”. He also said that it’s “as if a super-intellect had monkeyed with physics”.
Thus, Hoyle acknowledged the appearance of fine-tuning, and he took it seriously. However, he didn’t treat that appearance as final or ultimate.
Let’s return to Paul Davies
First-Class Fine-Tunings and Evolution
Davies believes in evolution for both the animal kingdom and for the universe itself. However,
“[w]hen it comes to the laws of physics and the initial cosmological conditions [ ] there is no ensemble of competitors”.
In simple terms, there is no evolution when it comes to the laws of physics and the initial conditions. These things are what are required to allow all future evolutionary processes to begin. In evolutionary-speak, the laws didn’t need to compete with… anything. They were (or are) given. They are given, but Davies believes that they still should be explained.
Davies argues that once the laws and initial conditions are in place, then there’s almost no limit to the complexity and structural fit that can follow. In Davies’s own words:
“Unlike mechanisms, which can slowly evolve to more complex or organised forms over time, the ‘crossword’ of particle physics comes ready- made. The links do not evolve, they are simply there, in the underlying laws.”
Davies puts this in another simpler way when he tells his readers that “[t]he input is the cosmic initial conditions, and the output is organized complexity, or depth”.
Yet another way of putting this is the following: despite the various and numerous manifestations of complexity and structural fit, they occur in the way they did (or do) because the “crossword” was already “simply there”. The manifestations may be interesting on their own terms. However, the initial conditions and laws are even more interesting (at least to many fundamental physicists and cosmologists).
Yet there is a problem here.
Once the base parameters are fixed, you can generate an arbitrarily long list of “If X were slightly different, then Y wouldn’t occur” statements. It may well be the case that if X were slightly different, then Y wouldn’t occur. But have we moved to X being fine-tuned here?
It seems obvious that if X were different, then what follows from X would be different too.
Davies’s Unspoken Example
Davies himself points out a distinction between the first class and the second class of fine-tunings without saying that’s his purpose. He writes:
“It is particularly striking how processes that occur on a microscopic scale — say, in nuclear physics — seem to be fine-tuned to produce interesting and varied effects on a much larger scale — for example, in astrophysics.”
The underlying point is that the second class of “fine-tunings” is downstream of the first class.
The point here is that just because the first class is required for the second class (in this case, conditions and states in nuclear physics and things which occur in astrophysics), then that doesn’t mean that anything that happens in the second class must include fine-tunings too. Even if it can be said that certain things occur and (partially) have the physical nature that they do because of the fine-tunings of the first class, then that still doesn’t mean that the second class itself includes its own fine-tunings.
So now it will help readers to see what example Davies himself gives of this. He continues:
“Thus we find that the force of gravity combined with the thermodynamical and mechanical properties of hydrogen gas are such as to create large numbers of balls of gas. These balls are large enough to trigger nuclear reactions, but not so large as to collapse rapidly into black holes. In this way, stable stars are born. Many large stars die in spectacular fashion by exploding as so-called supernovae.”
Here we move from the small scale of the force of gravity and the thermodynamical and mechanical properties of hydrogen gas to the large scale of stars and black holes. It’s here that we can distinguish between the first class of genuine fine-tunings to what occurs downstream of that class.
Davies provides his own example. In The Mind of God, he wrote:
“Suppose it could be demonstrated that life would be impossible unless the ratio of the mass of the electron to that of the proton was within 0.00000000001 percent of some completely independent number — say, one hundred times the ratio of the densities of water and mercury at 18 degrees centigrade (64.4 degrees Fahrenheit).”
The electron-proton mass ratio (which, sure enough, directly affects chemistry and atomic structure) seems to be mentioned a lot in these debates. (Davies himself mentioned the electron-proton mass ratio directly above.) Yet isn’t it smuggling in yet another “miracle”, which is actually a consequence of the miracle of the values of the proton and electron?
So what about the electron itself and its values?
Take the following two conditionals:
If an electron were to “lose” its any of its properties of mass, charge and spin,
then it wouldn’t be an electron at all.
More relevantly and with a little more detail:
If an electron didn’t have a charge of -1, a mass of 9.109389 × 10 −31 kg and spin,
then it wouldn’t be an electron.
In other words, if the electron has precise properties/values, and the proton has precise properties/values, then the ratios between them must be equally precise too. More clearly, if the electron wouldn’t be the particle it is without having its precise values, then if the electron-proton mass ratio were at a different value, then we wouldn’t actually be talking about the electron at all. The only way the ratio could change is if the electron became a non-electron. (This would be a new particle that could exist in a “toy universe”.)
So, here again, people are being profligate with their “surprises”. Yet the mass ratio isn’t a surprise. It strictly follows from the nature and values of the electron and proton taken individually. Sure enough, we can be surprised by the values of protons and electrons too. The mass ratio itself isn’t really “miraculous”. It follows from the precise masses of the electron and proton. Once they’re “in place”, then the ratio is determined.
Davies himself asks a question about the supposedly “fishy” nature of these and other (what he calls) “coincidences”. He asks what makes them intrinsically improbable. For example:
“From what range might the value of, say, the strength of the nuclear force (which fixes the position of the Hoyle resonances, for example) be selected? If the range is infinite, then any finite range of values might be considered to have zero probability of being selected. But then we should be equally surprised however weakly the requirements for life constrain those values.”
In simple terms, what are we comparing the (actual) strength of the nuclear force to? What criteria determine the status of its values? If the nuclear force could (or might) have had any value in an infinite range of possible values, then each possible selection would “have zero probability of being selected”. But then Davies states something which I’ve noted many times myself. Any alternative to the fine-tunings would cause equal surprise. In Davies’s example, any alternative that still allows for life would cause as much surprise as the actual value of the nuclear force.
The problem here is that this is an example (fine-tuning for life) from the second class of fine tunings. And that’s why other values work too. Such things cannot be said of the first class of fine-tunings.
Note:
Excitement and surprise about improbabilities reminds me of something Richard Feynman once said:
“You know, the most amazing thing happened to me tonight. I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing!”
This passage from Feynman can be reformulated as this simple question:
Of all the millions of license plates in the state, why did I see that particular one tonight?
This question isn’t in exactly the same ballpark as talk of fine-tunings. However, it is on the borders of that ballpark.
To spell it out. It’s not weird or improbable that Feynman should have seen that particular number plate. So it may not be such a deep mystery that laws or constants have the values which they do have. Moreover, perhaps there’s no deep answer — other than mundane facts about probabilities — to the question as to why Feynman should have seen that number plate when he did. Similarly, with the values of particles, constants, etc. In other words, beyond the fact that these things are the way they are, there may be nothing more to say.
