Greg Rampinelli
The famous neo-Atheist biologist Richard Dawkins writes in The Blind Watchmaker, “The universe we observe has precisely the properties we should expect if there is at bottom, no design, no purpose, no evil and no good, nothing but blind pitiless indifference.”[i]
The evidence from physics shows that the universe is fine-tuned for life, which strongly suggests design and purpose. This is widely accepted among physicists, including prominent atheists like the late Stephen Hawking, who attempt to explain it through naturalist means. This article discusses some examples of fine-tuning in physics as well as its implications.
Examples of Fine-Tuning
The Hoyle Resonance
The idea of fine-tuning may have originated with astrophysicist Fred Hoyle, who was trying to discover why stars were able to create carbon. After the young universe cooled off enough for atoms to form, there were only two elements in the universe: hydrogen and helium. These atoms came together through gravity to form young stars. As these elements came closer together, the young stars heated up, and the resulting fusion process created the heavier elements, atoms with more protons and neutrons. Hoyle was puzzled because the fusion of beryllium (4 protons and 4 neutrons) with helium (2 protons and 2 neutrons) to create carbon (6 protons and 6 neutrons) was energetically unlikely: beryllium and helium together have a higher energy state than carbon. To produce enough carbon for the universe, there had to be a carbon excitation state with at least 7.596 and 7.716 megaelectron volts more than in the carbon ground energy state, which is a small range. He later discovered that this precise carbon excitation state existed, which is good because otherwise there would be no carbon in the universe (and hence no life).
Hoyle was impressed by the precision required. In 1981 he wrote:
“Some super-calculating intellect must have designed the properties of the carbon atom, otherwise the chance of my finding such an atom through the blind forces of nature would be utterly minuscule. A common sense interpretation of the facts suggests that a superintellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.”[i]
Fundamental Particles
The fundamental particles in the universe include electrons and the up and down quarks, as well as a few other quarks, leptons (electrons, muons, tauons, and neutrinos), and force carriers (photons, gravitons, etc.). Up quarks have a charge of +2/3, down quarks have a charge of –1/3, and electrons have a charge of -1. Protons are made of two up quarks and one down quark, so they have a charge of +1. Neutrons consist of one up quark and two down quarks, so they have a charge of 0. Antiparticles, with opposite charges, also exist. The masses of these particles are important. The up quark has a mass of 2.3MeV, which is 4.5 times that of the electron, which has a mass of 0.511 MeV, while the down quark’s mass is 4.8 MeV, which is 9.4 times that of the electron. That means neutrons are heavier than protons. Since protons are lighter than neutrons, they are inherently stable. As neutrons are heavier, they will decay into a proton, an electron, and an antineutrino within about 15 minutes, unless they are captured in an atom’s nucleus.[ii]
Examples of Fine-Tuning of Particles
The masses of the particles are very important and appear to be fine-tuned. If the mass of the down quark were increased by a factor of 3, the only element in the universe would be hydrogen, as neutrons would decay even in a nucleus. If the mass of the up quark were increased by a factor of 6, protons would fall apart and decay into neutrons, positrons, and neutrinos. There would be no atoms, just a universe filled with neutrons. On the other hand, if the mass of the down quark declined by 8 percent, protons would capture electrons and form neutrons, creating a neutron universe. The same would happen if the mass of electrons increased by a factor of 2.5.[iii]
Are these different values for the quark masses and electrons theoretically possible? As far as we know, yes. An absolute upper boundary for the mass of particles is the Planck mass, at which the particle would become its own black hole. This mass is 1.2 x 1022 MeV, which is astronomically higher than the mass of the up quarks, down quarks, and electrons. The largest quark ever observed (the top quark) had a mass of 1.73 x 105 MeV, which is over 37,000 times larger than the down quark and over 78,000 times larger than the up quark. Even if we take this value as an upper boundary instead of the Planck mass, the likelihood of the up quark and down quark falling in a life-permitting range is very small. As for the electron, the muon and tauon, also leptons, are 206 and 3477 times heavier than the electron’s mass. While there might be reasons why the range of possible values would be less, we don’t know what they are. In conclusion, if the masses of the up quarks and down quarks were determined by chance alone, we would probably not have any elements besides helium.
Neutrinos are extremely common particles, numbering about 340 million per cubic meter in the universe, compared to two hydrogen atoms per cubic meter. They are leptons like electrons but have very little mass, only about one-millionth of the electron’s mass. If the neutrino’s mass increased by a factor of 2, the additional mass in the universe would have prevented galaxy formation.[iv]
Fundamental Forces
Physicists recognize four fundamental forces: the gravitational force, the electromagnetic force, the strong nuclear force, and the weak nuclear force. The gravitational force is familiar to us in everyday life: If you drop a ball, it will fall to the ground. We experience the electromagnetic force through electricity and magnetism, but its importance goes far beyond that. For example, the light we see results from this force. With the electromagnetic force, particles with opposite charges (e.g. protons and electrons) attract each other, while particles with the same charge repel each other. The strong force holds the nucleus of an atom together, while the weak force governs radiation but can also convert up quarks into down quarks, and vice versa. These forces can be described through equations. For example, Newton’s gravitational force equation is F = G(M1M2)/d², where M1 is the mass of the first object, M2 is the mass of the second object, d² is the square of the distance between them, and G is the gravitational constant. All forces have constants in their equations. But physics can’t explain why the constants have the values that they do.
Examples of Fine-Tuning of Forces
If the strong force were twice as strong, the early universe would have turned more than 90 percent of the hydrogen formed into helium, instead of the actual 25 percent. In this hydrogen-poor universe, stars would burn very poorly and probably not create more complex elements. Similarly, if gravity were stronger, the universe would have cooled more slowly and protons would have been locked away in helium, so the universe would not have enough hydrogen to make efficient stars or complex elements.[v] But if gravity were much weaker, stars and galaxies would not have formed at all. As for electromagnetism, if it were much weaker, there would be no chemical reactions. If the strong force were much weaker, nuclei larger than hydrogen would not exist. Likewise, if the weak force were weaker, we’d have more neutrons, and all hydrogen would be transformed into helium.
As an example, let’s look at gravity. The strongest of the fundamental forces, the strong force, is 1040 times stronger than gravity. If we take that as an upper bound, the range that gravity could fall in while still permitting life is quite small. If gravity’s force were increased by 3×10³, planets could not last for more than a billion years, which would not be enough time for life to develop. Divided by the maximum range of 1040, the probability that gravity would be consistent with life would be a minuscule 3×10-37. That’s 3 divided by 10 followed by 37 zeros. In contrast, 3 chances in a billion would be 3 divided by 10 followed by 9 zeros. If gravity increased by a factor of a billion (109), any land animals larger than insects would be crushed, or the earth would have to be reduced to a diameter of about 13 meters. But the probability that gravity would fall by chance even within this range is 1031, still minuscule.[vi]
The ratios of the fundamental forces are also important. The ratio of the gravitational force to the electromagnetic force could not vary much from its current value, or there would be no stable stars. The range of ratios consistent with stable stars is about 1 in 1035 of all possible ratios.[vii] The ratio of the strong force to the electromagnetic force must likewise be similar to its current value. If the ratio were significantly different (0.4 percent), stars would not create carbon (if the strong force were stronger), or the carbon created would all turn into oxygen (if the strong force were weaker).[viii] Furthermore, many elements would not be stable if the ratio of the strong force to the weak force were significantly lower.[ix]
The Cosmological Constant
Einstein originally introduced the cosmological constant, Λ, into his field equations of general relativity to offset the effect of gravity, which would otherwise cause the universe to collapse into itself. He later removed it, but physicists found that it was necessary and so added it back in. Cosmologists today interpret it as “dark energy”, the energy associated with the quantum vacuum. This energy causes the universe’s expansion to accelerate, which is what we observe. The problem is, if we add up the energies in the vacuum, we get a much larger number – by a factor of 10120 – than the actual observed constant. In other words, there must be something that offsets this and does so to an exquisite degree of precision. One possibility might be negative dark energy, which would offset the positive dark energy. If this is the correct interpretation, the ratio of positive and negative dark energy appears to be very precise, since the cosmological constant is 2.888×10-122 lP-2.[x] This is very close to zero, but not quite. If the cosmological constant were strongly negative, the universe would collapse since it would not offset gravity.[xi] If it were slightly more positive, the universe’s expansion would accelerate even more, and galaxies and stars would not have formed.[xii]
The Density of the Universe
The parameter Ω, commonly known as the density parameter, is the mean density of the universe divided by the “critical density”, which is the density at which the universe is flat and Euclidean geometry applies. The density parameter is very close to 1. At the time of the Big Bang, the universe needed to expand at just the right rate. If the expansion rate had been too small, the density would have been much larger than the critical value, and the universe would have recollapsed before galaxies and stars could form. If the expansion rate had been too large, the density would have been much smaller than the critical mass, and regions of small excess density (inhomogeneities) would have been too small for gravity to condense into galaxies. To avoid both cases, Ω at one second after the Big Bang would have to be equal to 1 to within an error of 10‑15.[xiii] Put another way, the density of the universe one nanosecond after the Big Bang was around 1024 kg/m³. If it had been just one kg/m³ higher, the universe would have collapsed by now. If it had been one kg/m³ lower, the universe would have expanded too rapidly to form stars and galaxies.[xiv]
Entropy
Entropy means disorder. According to the Second Law of Thermodynamics, a closed system over time will increase in entropy. That means, the energy it has available to do useful work will decline over time since its energy will be transformed into heat, which will dissipate. Eventually, our universe will die a heat death, with no useful energy available and all matter dispersed throughout space. That we obviously have not reached a state of total entropy means the universe is not infinitely old (which we already know from the Big Bang). It also means that the amount of entropy was less in the past as the universe was younger. The closer we are to the Big Bang, the lower the entropy. If the universe were organized simply by chance, high entropy universes would be far more likely than the low entropy universe we have. Oxford physicist Roger Penrose estimated the likelihood that our universe would have such low entropy as it has at 1 chance in 1010(123). That’s 101230. In comparison, the known universe has “only” about 1080 particles.
There are other examples of fine-tuning in the universe. These are just some of the most prominent ones. There are also arguments that our planet is fine-tuned for life and that the origin of life required a high degree of fine-tuning as well, but these will be the subject of other articles.
Explanations
Explanation 1: There is no real fine-tuning
Physicist Victor Stenger argued that the laws of physics had to be as they were, and no other self-consistent laws were possible. Furthermore, science can explain the apparent fine-tuning. A variant of this argument is, since we haven’t observed any other values for these constants of nature (since we haven’t observed any alternative universes), we simply can’t say whether there’s fine-tuning or not. This is a minority view. Most physicists, including prominent atheists like Stephen Hawking and Roger Penrose, recognized the reality of fine-tuning. Now, perhaps some of these examples of fine-tuning could not be otherwise, given the laws of science. And some physicists hope that a “theory of everything” will someday explain the apparent fine-tuning. There’s clearly some wishful thinking here.
Explanation 2: The Weak Anthropic Principle
The weak anthropic principle argues that any universe we observe would have to be fine-tuned for life since otherwise, we couldn’t observe it – we wouldn’t exist. This explanation is not satisfying. It’s like saying that a man facing a firing squad survives, but there’s no need to explain why, since if he hadn’t survived, he wouldn’t know that he did. The argument is circular. If a man facing a firing squad survives, the most logical explanation is that the shooters intentionally missed. The weak anthropic principle combined with the multiverse is discussed below.
Explanation 3: The Strong Anthropic Principle
As argued by John Barrow and Frank Tipler, the strong anthropic principle argues that “the Universe must have those properties which allow life to develop within it at some stage in its history.” [i] One view of quantum mechanics argues that everything is in the form of potential particles until collapsed when observed. In other words, observers determine reality from potential reality by observing it. This is not as far-fetched as it sounds. Experiments show that light can be in the form of waves or particles, depending on how it is observed. Still, this is a minority position.
Explanation 4: The Multiverse, Combined with the Weak Anthropic Principle
The idea of the Multiverse is consistent with some “theories of everything”. One theory is that the quantum vacuum generates “island universes” eternally. The field of island universes expands (inflation) so that these universes are completely independent of each other. Each would have its own set of physical laws and constants. If an infinite number of universes are generated, sooner or later there will be one (or more) that would permit life. Then the weak anthropic principle applies: if we observe a universe, it must be one that supports life. This theory cannot be proved or disproved.
An argument against this is based on “Boltzmann brains”. Named after 19th-century physicist Ludwig Boltzmann, a Boltzmann brain is a fully formed brain with memories of past events that didn’t exist. The argument is, it’s far more likely that random fluctuations in the quantum vacuum would create a small universe observed by a Boltzmann brain than a huge universe like ours. While the argument might sound ludicrous, is it any less realistic than the Multiverse theory?
The Multiverse theory is currently the most popular one among physicists attempting to explain fine-tuning without a designer. But if the Multiverse theory is true and the quantum vacuum is everywhere, why don’t we observe new universes popping into existence?
Explanation 5: Aliens from outside the Universe
Elon Musk and others argue that an advanced civilization from outside the universe might have created a computer game that mimics a universe. This simulation is so realistic that we think we are real, even though we’re only part of the simulation. This begs the question of how the aliens’ own universe came into being.
Explanation 6: God
Theists, such as Christians, Jews, and Muslims, believe in a God who created the universe. God is omnipotent, omniscient, and transcendent, outside space and time. Such a God could certainly create a finely tuned universe and would do so if He wanted life to exist.
The principle of Occam’s Razor says we should prefer the simplest explanation. Assuming that fine-tuning is real, which it certainly seems to be, the best competing explanations are the Multiverse and God. While committed atheists reject God as an impossible explanation and so embrace the Multiverse, the Multiverse is a complex cause that requires an infinite number of universes to explain fine-tuning. Theists argue there’s also other evidence for God (such as revelation and experience), so it’s hardly surprising that God created a life-permitting universe. While not denying the possibility of a Multiverse (God could make one if He wanted), theists claim that Occam’s Razor favors a designer God.
[i] Dawkins, Richard The Blind Watchmaker, p. 133
[i] Fred Hoyle, “The Universe: Past and Present Reflections.” Engineering and Science, November 1981. pp. 8–12 Quoted in Wikipedia
[ii] Lewis and Barnes A Fortunate Universe p. 47
[iii] Lewis and Barnes A Fortunate Universe pp. 50-53
[iv] Lewis and Barnes A Fortunate Universe pp. 173-177
[v] Lewis and Barnes A Fortunate Universe p. 78
[vi] Holder, Big Bang, Big God pp. 96-97
[vii] Lewis and Barnes A Fortunate Universe p. 111
[viii] Holder, Big Bang, Big God p. 91, Lewis and Barnes A Fortunate Universe p. 118
[ix] Lewis and Barnes A Fortunate Universe pp. 72-75
[x] Wikipedia Cosmological Constant, retrieved Sep. 29, 2021
[xi] Lewis and Barnes A Fortunate Universe p. 158-159
[xii] Wikipedia Fine-Tuned Universe, retrieved Sep. 29, 2021
[xiii] Holder, Big Bang, Big God p. 88
[xiv] Lewis and Barnes A Fortunate Universe p. 167
[i] Dawkins, Richard The Blind Watchmaker, p. 133