PLANETS AND LIFE

Another recent gigantic leap forward in our knowledge of the universe, which will play a large role when we consider the theological implications of the cosmos as we now understand it, has been the growing evidence that the universe is teeming with planets. Furthermore, a huge number are likely to exist that are capable of sustaining some form of life based on chemical processes. This does not even include the possibility of other forms of life that may not be chemical.

There was never any theoretical reason to think that planets weren't plentiful. But finding actual evidence has been a daunting task because of the brightness of the stars they orbit. Nevertheless, modern technology has once again met the challenge.

Only a dozen or so planets have been detected by direct imagining, all except one, Fomalhaut b, being much larger than Jupiter. However, thousands of others have been discovered by indirect means in which the motion of the planet causes observable changes in the light seen from its parent star. As of November 6, 2013, 1,039 confirmed planets were listed in The Extrasolar Planets Encyclopedia.1

The Kepler Space Observatory was launched on March 7, 2009, with the express purpose of searching for Earth-sized planets. As of November 2013, Kepler had confirmed the detection of 167 planets with another 3,568 candidates awaiting confirmation.² On May 11, 2013, the failure of reaction wheels that are used to steer the spacecraft brought the main mission to a close. However, since the rest of the system is intact, Kepler is now operating in a new mode.

On November 4, 2013, astronomers from the Universities of California and Hawaii reported on their analysis of the measured brightnesses of forty-two thousand stars from the Kepler mission. They found 603 planets including ten that were Earth-sized, that is, with radii 1–2 times the Earth radius that also received comparable levels of stellar energy. That is, the planets orbited in a habitable zone where liquid surface water could exist.3

The authors concluded that 22 percent of sunlike stars harbor Earth-size planets orbiting in their habitable zones. Furthermore, they speculate that the nearest such planet may be as close as twelve light-years.

Seth Shostak, senior astronomer of the SETI (Search for Extraterrestrial Intelligence) Institute has crunched the data further.⁴ Since stars like the sun make up about 20 percent of the approximately two hundred billion stars in the Milky Way, this gives nine billion planets in our galaxy able to support life. In addition, Shostak refers to another analysis of Kepler data that implies 16 percent of all red dwarf stars sport planets in the habitable zone, thus adding another twenty-four billion candidates giving a total of perhaps thirty-three billion habitable worlds within our own galaxy.

Since there are about 150 billion other galaxies in the visible cosmos, this multiplies out to 5,000,000,000,000,000,000,000 planets (five sextillion) within our horizon capable of supporting life of some form. However, this number could be off by orders of magnitude, so just remember—it is very, very big.

These are just the planets within forty-six billion light-years of Earth, which is the horizon beyond which light cannot reach us in the 13.8 billion-year age of the universe. If inflation is correct, beyond that limit exists a far vaster region of space that Alan Guth estimates contains a minimum of twenty-three orders of magnitude as many galaxies as those inside our horizon.⁵ It is probably much greater.

This is not pure speculation. It is based on the empirically well-established cosmology. Also note that I am not talking about other universes here—just our universe—the result of a single big bang.

More speculative are estimates of the likelihood of life anywhere except Earth. As long as we do not have a proven theory of how life began, there will be those who will argue that it could only have been the result of a miraculous creation. As we will see later in the chapter, life on other planets, in particular, intelligent life, presents great difficulties for traditional theologies, which were formulated by people whose best knowledge of the universe was that Earth sat alone at the center of all there is.

However, based on our best current knowledge it is hard to imagine that in this immense universe there aren't countless planets with some form of life. That life is likely to be very different from our own, given the major role of random chance in the evolution of life. All we know about our kind of life based on carbon chemistry is that it developed very easily and quickly on Earth once the conditions were right. We also know that the chemicals needed for our kind of life, including amino acids, are very plentiful in space. We just have not found any evidence yet for extraterrestrial life because of the immense distances between stars.

THE FINE-TUNING QUESTION

In recent years, many theologians and Christian apologists have convinced themselves and their followers that they have a knock-down, drag-out scientific argument for the existence of God. They claim that the parameters of physics are so finely tuned that if any one of these parameters were just slightly different in value, life—and especially human life—would have not been possible anywhere in the universe.

Of course, like all design arguments this is a God-of-the-gaps argument that they cannot win in principle because they can never prove conclusively that the values of these parameters cannot be natural. But they keep trying.

Assuming, on no basis whatsoever, that those parameters are independent and could have taken on any value over a wide range, they conclude that the probability of a universe with our particular set of parameters is infinitesimally small. Further assuming, on no basis whatsoever, that the probability of a divine creator is not equally infinitesimally small, they conclude that such a creator existed who fine-tuned the universe for life, particularly human life. Note that there is also no basis whatsoever to assume that this creator was the personal God worshipped by Christians, Muslims, and Jews or the god of any major religion. A deist creator works equally well.

William Lane Craig summarized the argument this way in his 1998 debate with philosopher Massimo Pigliucci (and in other debates available on his website):

During the last 30 years, scientists have discovered that the existence of intelligent life depends upon a complex and delicate balance of initial conditions given in the Big Bang itself. We now know that life-prohibiting universes are vastly more probable than any life-permitting universe like ours. How much more probable?

The answer is that the chances that the universe should be life-permitting are so infinitesimal as to be incomprehensible and incalculable.

John Barrow and Frank Tipler estimate that a change in the strength of gravity or of the weak force by only one part in 10¹⁰⁰ would have prevented a life-permitting universe.6 There are around 50 such quantities and constants present in the Big Bang which must be fine-tuned in this way if the universe is to permit life. And it's not just each quantity which must be exquisitely fine-tuned; their ratios to one another must be also finely-tuned. So improbability is multiplied by improbability by improbability until our minds are reeling in incomprehensible numbers.⁷

Just because Craig's mind reels and he personally can't comprehend the numbers, it does not follow that they are in fact incomprehensible to the rest of us.

I have written extensively on the subject of fine-tuning but need to cover some of it again here for completeness. I will try to bring the subject up to date without, I hope, being too repetitive. Recently I contributed a chapter arguing against fine-tuning for an Oxford University Press anthology Debating Christian Theism and will refer to some of that material.8 Christian philosopher Robin Collins of Messiah College presented the case for fine-tuning in an accompanying chapter.⁹ In it he criticizes a number of my previous arguments, to which I will respond here. These responses have not appeared elsewhere.

The multiverse provides a very simple, purely natural, solution to the fine-tuning problem. Suppose our universe is just one of an unlimited number of individual universes that extend for an unlimited distance in all directions and for an unlimited time in the past and future. If that's the case, we just happen to live in that universe that is suited for our kind of life. Our particular universe is not fine-tuned to us; we are fine-tuned to it.

The multiverse explanation is adequate to refute fine-tuning. Note the multiverse does not need to be proved to exist to refute fine-tuning claims. It just must be plausible. Those who dispute this have the burden of proving otherwise. This they have not done.

Nevertheless, the multiverse remains unverified so it behooves us to continue to examine the credibility of the divine fine-tuning hypothesis for our single, lone universe.

In a book published in 2011 titled The Fallacy of Fine Tuning, I provided purely natural explanations for the values of the so-called fine-tuned parameters that appear most frequently in the theistic literature.¹⁰

Many authors have written on fine-tuning, often misleadingly referred to as the anthropic principle, which suggests it has something to do with human beings. They insist certain parameters are fine-tuned to exquisite precision. And, by “exquisite precision,” they don't just mean within an order of magnitude or 10 percent, or even 1 percent. Rather, they assert that some parameters must be tuned to one part in fifty to a hundred orders of magnitude for any life to be possible.

Before I get to the specific parameters that are supposedly so fine-tuned, let me say a word about my basic interpretation of their meaning. The models of physics are human constructions, and so it follows that the quantities, parameters, and “laws” that appear in these models are likewise constructed. It strikes me as somewhat-incongruous to think of them as fine-tuned by God or nature. Physicists in another galaxy might have their own models with a totally different set of parameters.

Thus the parameters that are supposedly fine-tuned need not have any specific ontological significance. Of course, the models must agree with observations and so, as I have emphasized, they must have something to do with whatever objective reality is out there. They are not arbitrary, just as a landscape painting is not a random splash of colors (unless it's by Jackson Pollock).

Let us now look at the specifics. Physicist and Christian apologist Hugh Ross lists twenty-nine “characteristics of the universe” and forty-five characteristics of the solar system “that must be fine-tuned for any kind of life to be possible.”11 Right off the bat this statement is incorrect. More than half of Ross's parameters do not address life in general but life on this planet alone and, in some cases, even more particularly to human life.

The most common fallacy made by Ross and others who agree with his position is to single out the carbon-based life we have on Earth and assume that it is the only possible type of life. According to Christian belief, humans are made in the image of God (Genesis 1:26), so it is not surprising that they find it difficult to imagine other life-forms. However, with only one example available, they simply do not have the data to allow them to conclude that all other forms of life are impossible, whether based on carbon chemistry or not.

Referring to the possibility that the parameters can vary randomly, Collins asks, “Why should they give rise to precisely the right set of laws required for life?”12 Well, that's the whole point. They didn't have to be precise to lead to some form of life somewhere in this vast universe. In The Fallacy of Fine Tuning I showed that wide ranges of physical parameters could plausibly lead to conditions, such as long ages of stars, that could in principle allow for the evolution of life of one form or another.

TRIVIAL PARAMETERS

Two of the parameters that appear in most lists of fine-tuned quantities are

• the speed of light in a vacuum, c, and
• Planck's constant, h.

As basic as these parameters are to physics, their values are arbitrary. The fundamental unit of time in physics is the second. As we saw in chapter 6, the units for all other measurable quantities in physics, except for those that are dimensionless, are defined relative to the second. The value of c is chosen to define what units will be used to measure distance. To measure distance in meters you choose c = 3 × 10⁸. To measure distance in light-years you choose c = 1.

The value of Planck's constant h is chosen to define what units will be used to measure energy. To measure energy in joules you choose h = 6.626 × 10^–34. To measure energy in electron-volts you choose h = 4.136 × 10^–15. Physicists like to work in what they call “natural units,” where ħ = h/2π = c = 1. Other arbitrary quantities that are often claimed to be fine-tuned include Boltzmann's constant, k_B, which simply converts from units of absolute temperature, degrees Kelvin, to energy, and Newton's gravitational constant, G, which also depends on the choice of units. In Planck units, G = 1.

PARAMETERS NEEDED FOR ANY FORM OF LIFE

Less trivially, let us look at five parameters that are claimed by theists to be so finely tuned that no form of life could exist in any universe in which any of the values differed by an infinitesimal amount from their existing values in our universe.13 These are:

• The ratio of electrons to protons in the universe
• The ratio of the electromagnetic force to gravity
• The expansion rate and mass density of the universe
• The cosmological constant

The ratio of electrons to protons in the universe

Ross asserts that if this ratio were larger, there would be insufficient chemical binding. If smaller, electromagnetism would dominate gravity, preventing galaxy, star, and planet formation.

The fact that the ratio is exactly equal to one can be easily explained. The number of electrons in the universe should equal the number of protons from charge conservation, on the reasonable expectation that the total electric charge of the universe is zero. While there are other charged particles in the standard model, the proton and electron are the only ones that are stable.

The ratio of electromagnetic force to gravity

Ross says that if this ratio were larger, there would be no stars less than 1.4 solar masses and hence short and uneven stellar burning. If it were smaller, there would be no stars more than 0.8 solar masses and hence no heavy element production.

The ratio of the forces between two particles depends on their charges and masses. As I have already remarked, despite the statement often heard in most (if not all) physics classrooms—that gravity is much weaker than electromagnetism—there is no way one can state absolutely the relative strengths of gravity and any other force. Indeed, if one were to define the strength of gravity using the only natural mass, the Planck mass, you find that gravity is 137 times stronger than electromagnetism.

The reason gravity is so weak in atoms is the small masses of elementary particles. This can be understood to be a consequence of the standard model of elementary particles in which the bare particles all have zero masses and pick up small corrections by their interactions with other particles.

Collins misunderstands this point when he writes: “Stenger's attempt to explain away this apparent fine-tuning [the low mass of the proton and neutron] is like someone saying protons and neutron are made up of quarks and gluons, and since the latter masses are small, this explains the smallness of the former masses.”14

This is a complete misrepresentation of my position. Nowhere have I used this argument. Collins provides no direct quotation or citation. In truth, I make the very reasonable assumption, based on the standard model, that all the elementary particles (the proton and neutron are not elementary) were massless when they were first generated in the early universe. All have low masses today, compared to the Planck mass, since those masses were just small corrections provided by the Higgs mechanism. And, before Collins complains that the Higgs mechanism is another arbitrary assumption, recall that it is part of the standard model, which emerged undesigned from the symmetries of emptiness and the randomness of symmetry breaking.

The expansion rate and mass density of the universe

Ross claims that if the expansion rate of the universe, given by the Hubble parameter H, were larger, there would be no galaxy formation; if smaller, the universe would collapse prior to star formation. He also asserts that if the average mass density of the universe were larger, there would be too much deuterium from the big bang and stars would burn too rapidly. If it were smaller, there would be insufficient helium from the big bang and too few heavy elements would form.

In chapter 12, we saw that inflation results in the mass density of the universe being very close to the critical value ρ_c. This, in turn, implies that H also has a critical value. Only one of the two parameters is adjustable. Let's assume it's H.

Now, in the approximation of a linear expansion given by Hubble's law (see chapter 8), the age of the universe is given by T = 1/H. This is currently 13.8 billion years and is hardly fine-tuned for life. Life could just as well have evolved for T = 12.8 billion years or T = 14.8 billion years. In fact, suppose T = 1.38 billion years. Then we could not have life now, but it would come along ten billion years or so later. Or, suppose T = 138 billion years. The life will have already appeared 124 or so billion years earlier.

The cosmological constant

The cosmological constant is equivalent to an energy density of the vacuum and is the favorite candidate for the dark energy, which is responsible for the acceleration of the universe's expansion—constituting over 68 percent of the total mass/energy of the universe.

We saw in chapter 13 that calculations of the energy density of the vacuum that assume it equals the zero-point energy give answers that are 50–120 orders of magnitudes larger than the maximum value allowed by observations.

Physicists have not reached a consensus on the solution to the cosmological-constant problem. Some prominent figures, such as Steven Weinberg¹⁵ and Leonard Susskind,¹⁶ think the answer lies in multiple universes. Both refer to the fact that string theory, or its more advanced version called M-theory, offers a “landscape” of perhaps 10⁵⁰⁰ different possible universes. But we have no need for such speculation.

As I pointed out in chapter 13, the original energy-density calculations incorporated a fundamental error by summing all the states in a given volume. Since the entropy of a system is given by the number of accessible states of the system, the entropy calculated by summing over the volume will be greater than the entropy of a black hole of the same size, which depends on its area rather than its volume. But since we cannot see inside a black hole, the information that we have about what is inside is as small as it can be and so the entropy is as large as it can be.

Therefore, it was a mistake to calculate the number of states by summing over the volume. Correcting this by summing over the area, or, equivalently, setting the number of states equal to the entropy of a black hole equal to the size of the volume, we can naturally constrain the vacuum energy density. This calculation yields the result that an empty universe will have a vacuum energy density about equal to the critical density, just the value it appears to have.

For technical reasons, cosmologists are not ready to accept this solution to the cosmological-constant problem. Nevertheless, I think it is fair to conclude that the original calculation is simply wrong—as far wrong as any other calculation in the history of physics—and should be ignored. In any case, don't give up all your worldly goods and enter a monastery or convent because the cosmological constant is so small.

OTHER PARAMETERS

This takes care of the five parameters that are supposedly fine-tuned to such precision that even a tiny deviation would make life of any kind impossible. Note that only four are independent despite theist claims. Next let us move to those parameters for which proponents of fine-tuning can only use to claim that life would be very unlikely if the values of the parameters were slightly different.

The Hoyle prediction

In chapter 9, we covered the brilliant achievement of astronomer Fred Hoyle and his collaborators in showing how most of the elements of the periodic table are formed in stars during gravitational collapse after burning all their hydrogen fuel. In 1951, Hoyle predicted that the carbon nucleus would have an excited state at about 7.7 MeV above its ground state in order for enough carbon to be produced in stars to make life in the universe possible. This story is of great historical interest because it is the only case where anthropic reasoning has led to an empirically verified prediction. Shortly thereafter the excited state was found at 7.656 MeV.

However, calculations since have demonstrated that the same carbon would have been produced if the excited state were anyplace between 7.596 MeV and 7.716 MeV. Furthermore, sufficient carbon for life would have occurred for an excited state anywhere from just above the ground state to 7.933 MeV.¹⁷ A state somewhere in such a large range is expected from standard nuclear theory. Furthermore, carbon is not the only element upon which life might be based.

Relative masses of the elementary particles

The masses of elementary particles affect many features of the universe, and a number of fine-tuning claims refer to their values. Let me begin with the mass difference between the neutron and the proton. If the difference in masses between the neutron and the proton were less than the sum of the masses of the electron and the neutrino (the neutrino mass in our universe is negligible for this purpose but may not be in some other universe), there would be no neutron decay. In the early universe, electrons and protons would combine to form neutrons and few, if any, protons would remain. If the mass difference were greater than the binding energies of nuclei, neutrons inside nuclei would decay, leaving no nuclei behind.

There is a range of 10 Mev or so for the mass difference to still be in the allowed region for the full periodic table to be formed. The actual mass difference is 1.29 Mev, so there is plenty of room for it to be larger. Since the neutron and proton masses are equal to a first approximation, and the difference results from a small electromagnetic correction, it is unlikely to be as high as 10 MeV.

Next let us bring in the mass of the electron, which also affects the neutron-decay story. A lower electron mass gives more room in parameter space for neutron decay, while a higher mass leaves less.

The ratio of the electron and proton masses helps determine the region of parameter space for which chemistry is unchanged from our universe. We can show that this region is quite substantial and no fine-tuning is evident here either.

Relative strengths of the forces and other physics parameters

The dimensionless relative force strengths are the next set of physical parameters whose fine-tuning is claimed for reasons I found wanting. The gravitational-strength parameter α_G is arbitrary. Thus, there is nothing about α_G to fine-tune. As we have seen, the so-called weakness of gravity compared to the electromagnetic force between elementary particles results from their low masses and not their relative inherent strengths.

Next let me consider the dimensionless strength of the weak interaction α_W. Ross claims it is fine-tuned to give the right amount of helium and heavy-element production in the big bang and in stars. The key is the ratio of neutrons to protons in the early universe when, as the universe cools, their production reactions drop out of equilibrium. A significant range of parameters is allowed.

The electromagnetic strength represented by the dimensionless parameter α, historically known as the fine-structure constant, has the famous value 1/137 at low energies. Ross tells us that there would be insufficient chemical bonding if it were different. But, as I proved in The Fallacy of Fine-Tuning, the many-electron Schrödinger equation, which governs most of chemistry, scales with α and the mass of the electron. Again, a very wide range allows for chemistry as we know it and, particularly, the chemistry of life.

There are many places where the value of α relative to other parameters comes in. I have attributed the weakness of gravity relative to electromagnetism in matter to the natural low masses of elementary particles. This can also be achieved with a higher value of α, but it's not likely to be orders of magnitude higher.

The relative values of α and the strong force parameter α_S also are important in several cases. When the two are allowed to vary, no fine-tuning is necessary to allow for both nuclear stability and the existence of free protons.

There are two other facts that most proponents of fine-tuning ignore: (1) the force parameters α, α_S, and α_W are not constant but vary with energy; (2) they are not independent. The force parameters are expected to be equal at some unification energy. Furthermore, the three are connected in the current standard model and are likely to remain connected in any model that succeeds it. They are unlikely to ever differ by many orders of magnitude.

Other parameters such as the decay rate of protons and the baryon excess in the early universe have quite a bit of room to vary before they result in life-threatening radiation.

Cosmic parameters

We have already disposed of the cosmic parameters that were deemed so crucial in making any livable universe possible: the mass density of the universe, the expansion rate, and the ratio of the number of protons and electrons are not only not fine-tuned, they are fixed by conventional physics and cosmology or, in the case of the Hubble parameter, practically any value would allow for life.

Similarly, the deuterium abundance has little relation to the existence of life. The amount needed for life is small, and a wide range of two orders of magnitude is allowed.

The Astronomer Royal of the United Kingdom, Martin Rees, and others have claimed that the lumpiness of matter, represented by a quantity Q, in the universe had to be fine-tuned within an order of magnitude to allow for galaxy formation. An order of magnitude is hardly the kind of fine-tuning the theists are claiming, which are more typically one part in fifty to one hundred orders. What's more, varying the nucleon mass along with Q allows, again, for more parameter space for life.

In chapter 14 we discussed the ΛCDM model that gives a precise fit to the anisotropies of the cosmic microwave background and is consistent with observations on galactic structure. That model contains only six adjustable parameters, none of which are included in the parameters Ross or other divine fine-tuners have made such a big show about. The density of matter is not a parameter but is assumed to equal the critical value. The expansion rate (Hubble parameter) is not an adjustable parameter but is calculated in the model. One parameter is the dark-energy density relative to the critical density. Rees's parameter Q is not included but is implicit in the calculation of galactic structure.

In short, the divine fine-tuners have to go back to the drawing board and run the ΛCDM model over a range of parameters and show that life of any form would be impossible unless the six parameters were exactly what they are of our universe.

Simulating universes

The aggregate properties of the universe as we know it today are determined by just three physics parameters: the electromagnetic strength α and the masses of the proton and electron, m_p and m_e. From these we can estimate quantities such as the maximum lifetime of stars, the minimum and maximum masses of planets, the minimum length of a planetary day, and the maximum length of a year for a habitable planet. Generating ten thousand universes in which the parameters are varied randomly on a logarithmic scale over a range of ten orders of magnitude, I find that 61 percent of the universes have stellar lifetimes over ten billion years, sufficient for some kind of life to evolve.

Collins has previously objected to my preliminary, twenty-year-old conclusion that long stellar lifetimes are not fine-tuned.18 He argues that not all these universes are livable, that I have not accounted for life-inhibiting features. He refers to John Barrow and Frank Tipler, who in their classic (though containing numerous typographical and mathematical errors) The Anthropic Cosmological Principle estimated that α ≤ 11.8α_S for carbon to be stable.¹⁹

Since in my study I was varying all the parameters by ten orders of magnitude, I would not expect such a tight criterion to be satisfied very often. Nevertheless, I have checked and found the Barrow-Tipler limit to be satisfied 59 percent of the time. I have also studied what happens when the parameters are varied by just two orders of magnitude. Then 91 percent of the time we have α ≤ 11.8α_S. Again I must stress that the fine-tuners are claiming far greater sensitivity than ranges of an order of magnitude.

Applying rather-tight limitations to all three parameters in order to produce life, 13 percent of all universes are capable of supporting some kind of life not too different from ours when I vary them by ten orders of magnitude. Varying by two orders of magnitude, which is more realistic since the parameters are not independent but related, I find that 92 percent of the universes have stellar lifetimes over ten billion years and 37 percent are capable of supporting some kind of life not too different from ours. Life very different from ours remains possible in a large fraction of the remaining universes, judging from the large stellar lifetimes for most.

I don't claim to have provided an explanation for the values of every parameter of physics and cosmology. I don't have to in order to refute the opposing claim that many are fine-tuned to incredible precision such as one in 120 orders of magnitude. Uncertainties of 1 percent, to 10 percent, or even an order of magnitude—as was the case for the lumpiness parameter Q—do not classify as fine-tuning.

SUMMARY OF THE CASE AGAINST FINE-TUNING

The following is a summary of the logical and scientific errors made by proponents of fine-tuning (not all make every error) that I have uncovered in my studies:

1. They make fine-tuning claims based on the parameters of our universe and our form of life, ignoring the possibility of other life-forms.
2. They claim fine-tuning for physics constants whose values are arbitrary, such as c, h, and G.
3. They assert fine-tuning for quantities whose values are precisely set by cosmological physics or have wide allowable ranges, such as the ratio of electrons to protons, the expansion rate of the universe, and the mass density of the universe. These are not even varied in the current standard cosmological model.
4. They assert that the relative strength of the electromagnetic and gravitational forces is fine-tuned, when in fact this quantity cannot be universally defined.
5. They assert that an excited state of the carbon nucleus had to be fine-tuned for stars to produce the carbon needed of life, when calculations show that a wide range of values for the energy level of that state will produce sufficient carbon.
6. They claim fine-tuning for the masses of elementary particles when the ranges of these masses are set by well-established physics and sufficiently constrained to give some form of life.
7. They assume the strengths of the various forces are constants that can independently change from universe to universe. In fact, they are dependent on one another and vary with energy, and their relative values and energy dependences are close to being pinned down by theory, in ranges that make some kind of life possible.
8. Most make a serious analytical mistake in taking all the parameters in the universe to be fixed while varying only one at a time. This fails to account to the fact that a change in one parameter can be compensated by a change in another, opening up more parameter space for a viable universe.
9. They misunderstand or misuse probability theory, ignoring the fact that events with “mind-boggling” low probabilities occur billions of times a day. The only way one can use a low probability to argue that something is unlikely is to compare it with the probabilities of all the alternatives. What is the probability of God? In The Fallacy of Fine-Tuning, I compared the calculations for the probability of God using sophisticated Bayesian statistics made by two physicists, one a believer and one a nonbeliever. The believer came up with 0.67, while the nonbeliever's result was 10^–17.20
10. They claim many parameters of Earth and the solar system are fine-tuned for life, failing to consider that with quadrillion planets in the visible universe in habitable regions of their stars, and the countless number beyond our horizon, a planet with the properties needed for life is likely to occur many times. Nevertheless, the universe is hardly life-friendly. If God wanted to fine-tune it for life, he could have made it a lot friendlier.
11. The fine-tuners are also wrong to reject the multiverse solution as “unscientific.” It is not unscientific to speculate about invisible, unconfirmed phenomena that are predicted by existing models that, so far, agree with all the available data. The neutrino was predicted to exist in 1930 based on the well-established principle of energy conservation but was not detected until 1956, and even then indirectly. If the physics community and granting agencies had used the fine-tuners’ criterion, my late colleague Fred Reines and his (also late) collaborator Clyde Cowan would not have been able to get the money and support to engage in the search that finally discovered the neutrino.
12. The current, highly successful ΛCDM cosmological model has only six parameters, none of which has been shown to be fine-tuned.

As my discussion illustrates, the explanations for apparent fine-tuning are technical and require adequate training to understand. A proper analysis finds there is no evidence that the universe is fine-tuned for life and all we have is yet another God-of-the-gaps argument that is doomed to failure by its implicit assumption that some phenomena exist that science will never be able to explain without introducing God into the explanation.

SOMETHING RATHER THAN NOTHING

Since cosmic creationists continue to fail in their attempts to use science to provide a credible case for a creator god, they frequently fall back on three questions that are increasingly more philosophical in the order presented below:

1. How can something come from nothing?
2. Where do the laws of physics come from?
3. Why is there something rather than nothing?

1. How can something come from nothing?

The first question can still be discussed in largely scientific terms. Let me restate it as follows: How can matter come from nonmatter?

The universe has mass, which is a measure of the amount of matter, and since mass and rest energy are equivalent, it would seem that the law of conservation of energy must have been broken to create the matter of the universe out of “nothing.”

However, we have seen that when the negative potential energy of gravity is included, the total energy of the universe is zero, give or take quantum uncertainties. So the law of conservation of energy was not broken for the universe to appear from an earlier state of zero energy and zero matter.21 Indeed, no law of physics was broken in bringing our universe into existence. And, of course, no law of physics was broken in bringing the multiverse into existence, since it always existed.

Now, I need to mention that there is considerable debate over whether one can define the total energy of the universe within the framework of general relativity. There are prominent physicists and cosmologists on both sides of the argument. I will not go into this question, which is highly technical.

However, I have a simple observation. As I have explained, according to Noether's theorem, energy conservation is required in any model that is to apply at all times. Einstein's general relativity is a model. If you are building a model based on general relativity you have two choices: (1) include energy and energy conservation in your model to help guarantee it is good at all times or, (2) exclude energy and energy conservation and accept the fact that the model isn't valid at all times.

2. Where do the laws of physics come from?

This leads to the second question: Where did the law of conservation of energy and, indeed, all the laws of physics come from? Robin Collins argues that any explanation for a universe without God only works if “the explanation does not merely transfer fine-tuning up one level to newly postulated laws, principles and parameters.”²²

I don't see how transferring fine-tuning up one level to God is any improvement. In fact, it is less informative since we have no idea how God did his fine-tuning whereas we have some idea from cosmological science how the universe may have come from nothing. In the first case we can do nothing useful with that assumption. In the second case we can make certain predictions that are empirically testable. For example, we can predict that the energy density of the universe will always remain at it critical value as measurements continue to improve.

In any case, we have seen that the “law” of conservation of energy follows from the fact that there is no special moment in time. It was not handed down by God. It's more necessary than God.

As described in chapter 11, physicists in the twentieth century discovered a set of principles I call metalaws that are required to be present in all physics models. In order to describe the universe objectively, physicists must formulate their models so that they describe observations in ways that are independent of the point of view of particular observers, what I call point-of-view invariance. This gives the model builders no choice but to include the great conservation principles or metalaws of energy, linear momentum, angular momentum, and electric charge. Point-of-view invariance leads to all of classical physics, including Newton's laws of mechanics and gravity, Maxwell's equations of electromagnetism, thermodynamics, fluid mechanics, and Einstein's theory of special relativity. Much of general relativity and quantum mechanics (if not all), including the Heisenberg uncertainty principle, also follow.²³

When I argue that some parameter is in a range consistent with known physics, apologists come back with, “Where did physics come from?” My answer: the physics came from physicists formulating models to describe observations that must include metalaws that constitute the basic laws of physics. The metalaws do not set all the parameters of physics. Many occur by accident. However, as we have seen, the values of the parameters in the models that successfully describe all observations in our universe are within the ranges set by the metalaws.

3. Why is there something rather than nothing?

The third question is largely philosophical because it deals more with the meaning of words than with actual physics. In a book published in 2012 called A Universe from Nothing: Why There Is Something Rather Than Nothing,²⁴ cosmologist Lawrence Krauss describes how our universe could have arisen naturally from a preexisting structureless void he calls “nothing.” I don't think anything he says disagrees with this book, which was written independently.

In a New York Times review of Krauss's book, philosopher David Albert asks “why the world should have consisted of the particular elementary stuff it does, as opposed to something else, or to nothing at all.”25 Krauss admits he does not know but suggests it may arise randomly, in which case some universe like ours would have arisen without a prescribed cause.

Clearly, no consensus exists on how to define “nothing.” It may be impossible. To define “nothing” you have to give it some defining property, but, then, if it has a property it's not nothing!

Albert was not satisfied that Krauss answered the fundamental question: Why there is something rather than nothing, that is, why is there “being” rather than “nonbeing”? Again, I have a simple retort to Albert: Why should nonbeing, no matter how defined, be the default state of existence rather than being? Why is some creative act needed to convert nonbeing to being? Perhaps such an act is needed to convert being into nonbeing.

If nonbeing is the natural state, then why is there God? Once theologians assert that there is a God as opposed to nonbeing, they can't turn around and demand a cosmologist explain why there is a universe as opposed to nothing. They claim God is a necessary entity. Why can't a godless multiverse be a necessary entity?

As my late friend and colleague mathematician Norm Leavitt once said, “What is there? Everything. So what isn't there? Nothing.”

But we can do even better than this standoff and make an argument for something being a more natural state than nothing. We can provide a plausible reason based on our knowledge of existing physics.

It is commonly thought that a complex physical system can only come about by the deliberate act of an intelligent designer who must necessarily be even more complex. The chain of design then leads back to God as Aristotle's Prime Mover and Aquinas's First Cause Uncaused, the maximally complex creator of all that is.

We even do not have to rely on sophisticated scientific arguments to see from common experience alone that Aristotle and Aquinas, as well as everyone since who has used the design argument, had it backward. In nature, complexity arises out of simplicity. Consider the phase transitions observed in familiar matter. In the absence of external heat, water vapor will naturally condense into liquid water, which then will freeze into solid ice. With each transition, we move from a state of higher symmetry to one of lower symmetry—from simplicity to complexity. Complexity is broken symmetry, and the transition from simple to complex occurs spontaneously. Simplicity begets complexity, not the other way around. The particular crystal structure that results from the liquid-water-to-ice transition is unpredictable, that is, random. No two snowflakes, which result from a direct vapor-to-solid transition, are alike.

Physical systems move naturally from simple to complex without the need for design. Indeed, the fact that specific events, such as atomic transitions, are random can be taken as strong evidence against any design, intelligent or stupid.

And so how do we get something from nothing? Since no thing is more symmetric than nothing, we would expect nothing to naturally undergo a phase transition to something. As Nobel laureate Frank Wilczek put it in a Scientific American article back in 1980, “Nothing is unstable.”26

It also should be remarked that although the universe is something rather than nothing, it is pretty close to being nothing in the sense that it is only 30 percent matter, which makes it 70 percent nothing.

I have presented the material in this section, in one form or another, in several books. However, if you want to read an excellent elucidation of these ideas at a layperson level by a professional science writer, see chapter 7 of The Never-Ending Days of Being Dead by Marcus Chown.²⁷

THE GRAND ACCIDENT

Stephen Hawking and Leonard Mlodinow addressed the something-from-nothing question in their 2010 book The Grand Design, mentioned in the previous chapter. They concluded, “Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist. It is not necessary to invoke God to light the blue touch paper and set the universe going.”²⁸

The book should have been called The Grand Accident, because that's what “spontaneous” refers to—an uncaused accident. The authors agree there was no design, grand or otherwise. I suspect the publisher picked the title to sell more books.

Hawking and Mlodinow provide a picture of spontaneous creation that follows from Feynman's sum-over-histories formulation of quantum mechanics, which was mentioned in chapter 15.

As we have seen, M-theory offers the possibility of 10⁵⁰⁰ universes with different properties. Hawking and Mlodinow propose that these are “alternate histories” to which Feynman's model can be applied. By summing over all the histories we get the probability for the universe that we observe.

In this view, the universe is taken as it is at the present time and the most probable path back to the origin is calculated. As the authors put it, “The universe appeared spontaneously, starting off in every possible way.”²⁹ The 10⁵⁰⁰ universes converged on the one that has the necessary structure to produce life as we know it. With such a huge number of possibilities, many would be expected to allow for some kind of life different from ours as well as for our kind.

Hawking and Mlodinow also emphasize, “The multiverse is not a notion invented to account for the miracle of fine-tuning, as often charged by apologists.” Rather, “it is a consequence of the no-boundary condition as well as many other theories of modern cosmology.”³⁰ And once you have one accidental universe, you will have many.

THE GOD HYPOTHESIS

So, where does that leave the hypothesis of God? I often hear the argument that God is not a scientific hypothesis since he is a spirit that can never be observed. Furthermore, religion and science are two separate realms and one should not be applied to describe the other. However, if God has any role in the universe, the results of some of his actions should be observable even if he is not, and science can be called upon to attempt to test if those observations have a supernatural cause.

In the spirit of Ockham's razor, we must recognize that currently God is an additional hypothesis not required by the data. If he were, he would be included in the set of premises that constitute scientific theories. He is not. While we certainly do not know everything, we know of no observed fact that requires the existence of God. Indeed, many observed facts that are inconsistent with the God hypothesis serve to prove beyond a reasonable doubt that a God who plays an active role in the universe and in human lives does not exist.31

On winter mornings I can look out my office window to an empty field covered with fresh snow. Occasionally I will see footprints of wild animals—foxes, coyotes, or whatever. I rarely see the animals themselves, but I know they exist by the fact that they left footprints. God has left no footprints on the snows of time.

Of course there are many purported facts that are claimed as evidence for God or gods. These are generally referred to as miracles, that is, events inconsistent with mundane and scientific explanation but with moral significance for those who observe them. But every time a claim is thoroughly investigated, its miraculous nature evaporates. Teardrops from a statue of Mary are found to be cooking oil from the rectory kitchen. The woman who got up and walked at the evangelical revival was placed in a wheelchair when she walked into the hall. The miraculous imprint on Jesus’ shroud was painted by a thirteenth-century con man.³²

Lourdes, France, is perhaps the most famous site of purported miracles. Visiting there, you will find on display many crutches that have been discarded. In a quotation usually attributed to the French author Anatole France (1844–1924) but actually expressed by one of his friends, “One single wooden leg would have been much more convincing.”33

Believing scientists and science-savvy Christian theologians have made heroic attempts to find a model of an active theist God, as opposed to an inactive, deist god, that is consistent with both science and Christianity. Most use quantum mechanics and chaos theory to find a place for God to act without the product of his actions showing up as miracles in our scientific instruments. But, as I showed in Quantum Gods,³⁴ and Robert Price and Edwin Suiminen have more recently confirmed in Evolving out of Eden,³⁵ it doesn't work. God simply isn't hidden in electron clouds.

A SUMMARY

This book has traced the history of humanity's view of the cosmos from the distant past to the present. Summarizing, we have seen that plausible scenarios exist for a natural origin of our universe—many worked out fully mathematically and published in peer-reviewed scientific journals. We now have a surprisingly simple model of cosmology that combines with the standard model of elementary particles to provide not only a description of the physical world that is fully consistent with all observations but also, in many cases, successful quantitative predictions of exquisite precision. Of course, neither should be taken as the “final word.”

While more speculative but still based on our best knowledge, cosmologists have inferred that our universe is but one in an unbounded, eternal multiverse that contains an unlimited number of other universes. Although one has not yet been observed, the possibility exists that another universe may have left a detectable imprint on ours. While the multiverse hypothesis is hardly confirmed, it has sufficient scientific backing to take it seriously and consider the philosophical and theological consequences.

Theologians and apologists who are willing to accept for the purpose of argument the possibility of many universes insist that their existence still requires some prior, divine cause. If, as I have argued, the multiverse follows as a consequence of the known laws of physics, they ask: Where did those laws come from other than a supernatural lawgiver?

Most physicists and cosmologists simply accept the laws of physics as brute facts and prefer not to involve themselves in theological debate. I have tried to show that the multiverse scenario can be described without recourse to any special dynamical principles or laws that must be assumed as brute facts.

To understand this requires a drastic revision of the common notion of natural laws as “ordinances” handed down by some great legislature in the sky. As we have seen, what we call the basic principles and laws of physics, such as the conservation laws, are simply statements that automatically appear in the mathematical models of physics when those models are designed to be independent of the point of view of any particular observer. It follows that the models contain certain symmetries, some of which can be broken spontaneously to give the tiny amount of asymmetry, one part in one hundred thousand, that leads to complexity in structures, such as galaxies, stars, and planets.

Few people, even scientists, have come to grips with the fact that the universe is mostly particles moving around randomly and that the wonder that so enamors us is just a minor statistical fluctuation.

The beautiful galactic structures that we spend so much time admiring constitute just 0.5 percent of the mass of the universe and a billionth of the total number of elementary particles therein. Most of the universe is composed of particles in largely random motion. That is, our universe looks very much as it should look if it came from a perfectly symmetric, unstructured state that we can, for want of a better name, call “nothing.”

The widespread assertion that our universe is fine-tuned for life is greatly overblown and not required by known physics. Our existence on Earth is a simple matter of natural selection. With every type of planet possible in the multiverse, we naturally evolved on one with the properties needed for intelligent life.

In short, nothing in our observations of the universe requires the existence of God. Furthermore, the absence of evidence that should be there for the actions of God rules out beyond a reasonable doubt the kind of God worshipped by most of humanity.

The universe visible from Earth contains an estimated 150 billion galaxies, each galaxy containing on the order of a hundred billion stars. It is known to be 13.8 billion years old with an uncertainty of less than one hundred million years. The most distant object we can in principle see is now forty-six billion light-years away, taking into account the expansion of the universe during the time the photons carrying its image traveled to our telescopes. This marks a horizon beyond which we cannot see because light has not had the time to reach us in the age of the universe.

As discussed in chapter 14, well-established inflationary cosmology implies that on the other side of our horizon lies a region containing at least twenty-three orders of magnitude as many galaxies as those inside, which arose from the same primordial seed that produced our universe. It is likely to be many orders of magnitude greater. Our visible universe can be likened to a grain of sand in the Sahara desert.

And that's just our personal universe. Besides that, a strong case can now be made that we live in an eternal multiverse containing an unlimited number of other universes. However, for the purposes of the discussion in this section I will ignore the possibility of other universes and just stick with the one that indisputably exists—our own.

Let us consider two alternative possibilities that are so far consistent with our best knowledge:

1. Intelligent life exists on only a single planet, Earth.
2. Life is rare, and intelligent life even rarer. But the universe is so vast that there still are countless numbers of intelligent beings in our universe.

1. We are alone

Believers are told that they are the special creation of a single divinity that created everything that is. While making sure every photon and electron in the universe behaves properly without us noticing, their God is also listening to their every thought and helping them to do the right thing—as he defines it.

This involves God controlling momentous events such as telling a president of the United States to go to war, as George W. Bush said God did,36 or redirecting a tennis ball off a Christian lady's racquet so it wins her the point as she shouts, “Thank you, Jesus!”

Of course, a God of limitless power could do all that. By why would he have waited until just 150,000 years ago to create humans? And why would he have confined us to a tiny speck of dust in a vast ocean of space, with no chance, at least with our present physical makeup, of ever traveling much beyond the environs of Earth? If he desired the worship of humans so badly, then you would think he should have made it available to him for all times and at all places.

As we have seen, apologists make an illogical argument that they think is the clincher for the existence of God. They claim that life in the universe depends very sensitively on the value of a large number of physical parameters. According to this view, since the specific values of the parameters needed for life cannot possibly have resulted from chance (they can't prove that), they must have been “fine-tuned” by God in order to produce us.

Surely any God worthy of the name would not have been so incompetent as to build a vast, out-of-tune universe and then have to delicately twiddle all these knobs so that a single planet is capable of producing human beings. It would have made a lot more sense for him to have enabled us to live anywhere in the universe, even outer space. But the fact is—he did not.

So far, we know of no form of life anywhere in the universe besides Earth. At best we might one day find primitive life on Mars or someplace else in the solar system; any other intelligent life has to be a great distance away. Since 1979, the SETI program has listened for possible radio transmissions from alien civilizations with no success. Let's face it: the universe is not life-friendly. But it's not life-forbidding either, or else we wouldn't be here.

2. We are not alone

New estimates based on the brightness variations of thousands of stars measured by the Kepler Space Observatory suggest that within our horizon there may be as many as 5 × 10²¹ planets capable of sustaining biological life of some form.37 We have seen that beyond our horizon exists a far vaster region of space. It is estimated that this region contains a minimum of twenty-three orders of magnitude as many galaxies as those inside our horizon but is likely to be much bigger.³⁸ This gives at least 10⁴⁴ possible habitable planets in our universe.

This is not pure speculation. It is based on observations and the theory of cosmic inflation that is now empirically well established. So even if the probability of intelligent life for an otherwise-habitable planet is miniscule, say one part in a trillion-trillion (10^-24), this leaves 10²⁰ planets with some form of intelligent life.

Of course, fundamentalists still believe literally in the cosmology of the Bible and think scientists are a bunch of frauds, so they have no self-contradiction here. Science is just wrong. There is just one universe created six thousand years ago with no evolution or climate change, which are just “hoaxes.”

Moderate Protestants and Catholics, on the other hand, have yet one more conflict between science and religion among the many they must reconcile in order to both accept the findings of science and still hold onto some semblance of Christian faith.

The Judeo-Christian-Islamic God is a mighty God when viewed from the perspective of the desert tribes in the Middle East that conceived him. But that God is not mighty enough from the perspective of modern science.

Religion claims to teach us humility. But it really trades in a false pride, telling people they are the children of God, that they are the center of the universe and the reason for its existence—that they'll live forever if they just follow instructions. But it's an unearned pride. So, when science shows that we occupy but a tiny mote in space and time, the religious recoil from this lesson in humility.

Still, the very fact that in the short period of a few thousand years humans have been able learn so much about the universe by just looking up in the sky and at the world around them, and reasoning over what they saw, testifies that we are unique among the millions of species on this planet. We cannot yet compare ourselves with whatever intelligent life-forms might be out there. But we are special, at least on Earth and in the solar system. Even though magical thinking and hubris may still destroy us, we can hope that our unique abilities will lead us to a better future.