Book Looks at the Universe's Many Royal Flushes

The fascinating question of cosmic fine-tuning has been given a very impressive and comprehensive treatment in the recent book A Fortunate Universe: Life in a Finely Tuned Cosmos by astrophysics professor Geraint F. Lewis and astronomy postdoctoral researcher Luke A. Barnes. The book looks at the many ways in which our universe seems to have improbably “hit the jackpot” or “won the lotto,” having a series of incredibly lucky breaks that were necessary for our eventual existence. On page 29 the authors describe the thesis of a fine-tuned universe like this: “The claim is that small changes in the free parameters of the laws of nature as we know them have dramatic, uncompensated, and detrimental effects on the ability of the universe to support the complexity needed for physical life forms.” 

One case involves the existence of abundant carbon and oxygen in the universe, two elements that must exist in abundance for life to exist. Carbon and oxygen didn't exist in the early history of the universe, which was almost entirely hydrogen and helium. Carbon and oxygen were formed gradually by stars. A great deal of luck is required for any universe to be able to produce either carbon or oxygen; and for a universe to produce abundant amounts of both carbon and oxygen, some fantastically improbable strokes of luck are required. The authors note this on pages 118-119 (referring to the strong nuclear force that binds protons and neutrons in the nucleus of the atom):

If we nudge the strength of the strong force upwards by just 0.4 per cent, stars produce a wealth of carbon, but the route to oxygen is cut off. While we have the central element to support carbon-based life, the result is a universe in which there will be very little water. Decreasing the strength of the strong force by a similar 0.4 per cent has the opposite effect: all carbon is rapidly transformed into oxygen, providing the universe with plenty of water, but leaving it devoid of carbon.

Protons and neutrons are made up of smaller particles called quarks. A proton is made of two up quarks and one down quark, while a neutron is made of two down quarks and one up quark. On page 50 to 51 of the Fortunate Universe book, we are told some reasons why a life-bearing universe requires that these quark particles have masses not too far from the mass they have. If the down quark was about 70 times more massive or the up quark was about 130 times more massive, there would be only one element, and complex chemistry would be impossible. More sensitively, if the up quark was more than six times more massive, protons could not exist, and there would be no atoms. But later we learn of a much more sensitive requirement demanding that the quark masses be almost exactly as they are in order for the universe to be hospitable for life.

Reiterating the conclusions of this scientific paper, the book also notes on page 120 that we would not have a universe with abundant carbon and oxygen if the quark masses were different by much more than a few per cent. The book notes how improbable such a case of “hitting the distant bulls-eye” was:

And remember from last chapter that because the quarks are already “absurdly light” in the words of physicist Leonard Susskind, a range of mass that is a small percentage of their value in our Universe corresponds to a tiny fraction of their possible range. It is about one part in a million relative to the Higgs field, which gives them their mass. It is about one part in 10²³ relative to the Planck mass!

On page 75 of the book we have a diagram that is basically the same as the diagram below from an article by one of the authors. The author shows that if you make random values for the strong nuclear force and a fundamental constant called the fine structure constant, then only a very tiny fraction will allow carbon-based life. Because the graph uses a logarithmic scale, it visually exaggerates the size of the tiny white rectangle. If you were to program a computer to assign random numbers for these two (the strong nuclear force and the fine structure constant) between 0 and 1000, less than one in a million times would the numbers end up within the tiny white rectangle. 

From Barnes article here

On page 63 the book has a discussion of fine-tuning involving the Higgs mass and Higgs boson:

Life requires a value not too much different to what we observe. There must be an as yet unknown mechanism that slices off the contributions from the quantum vacuum, reducing it down to the observed value. This slicing has to be done precisely, not too much and not so little as to destabilize the rest of particles. This is a cut as fine as one part in 10¹⁶...This problem – known as the hierarchy problem – keeps particle physicists awake at night.

On page 111 of the book we are told about some ways in which the strong nuclear force is sensitive to changes:

A small decrease in the strength of the strong force by about 8 per cent would render deuterium unstable. A proton can no longer stick to a neutron, and the first nuclear reaction in stars is in danger of falling apart. An increase of 12 per cent binds the diproton – a proton can stick to another proton. This gives stars a short cut, an easy way to burn fuel. If the diproton were suddenly bound within the Sun, it would burn hydrogen at a phenomenal rate, exhausting its fuel in mere moments.

So many royal flushes

Then there is the cosmological constant problem, the case of fine-tuning discussed here. It's the issue that quantum field theory predicts that ordinary space should be very densely packed with quantum energy, making it even denser than steel. But somehow we live in a universe that has only the tiniest sliver of the vacuum density that it should have. Below is what page 162 of the book has to say about this:

Maybe there is a mechanism at work here, a mechanism that we clearly don't yet understand, which trims the energy in the quantum vacuum; so, while it is intrinsically very large, the value we observe, the value that influences the expansion of the universe, appears to be much, much smaller. But this would have to be a very precise razor, trimming off 10¹²⁰ but leaving the apparently tiny amount that we observe....But what if this mechanism for suppressing the influence of the cosmic vacuum energy was not so efficient, removing the effect of 10¹¹⁹ rather than 10¹²⁰, so there would be ten times the vacuum energy density we actually measure? Remember, such vacuum energy accelerates the expansion faster and faster, emptying out the Universe, cutting off the possibility of stars, planets, and eventually people.

Towards the end of the book, the authors discuss some common objections made to minimize the importance of such conclusions. One objection goes like this: improbable things happen all the time (for example, there was only 1 chance in a billion that you would have the 9-digit Social Security number that you have). The objection is easily dismissed on these grounds: improbable things do happen all the time, but improbable lucky things do not happen all the time. The cases of cosmic fine-tuning are not merely improbable things happening, but incredibly improbable lucky things happening; and it is not at all true that incredibly improbable lucky things happen all the time.

Another objection appeals to the existence of a multiverse: maybe there are an infinity of universes, and in such a case the odds of one of them being successful might be good. This is not a sound objection because it merely increases the number of random trials; and increasing the number of random trials does nothing to increase the chance of any one random trial succeeding. If you drive into Las Vegas and drive out with $50,000,000 in your car, that's an astonishing piece of luck; and it's no less astonishing if there are an infinity of such lucky winners scattered across an infinity of universes in which an infinity of different things happen. Adding a multiverse does not increase the odds of lucky events in any one particular universe such as ours.

In so many different ways (physics, cosmology, biology) the universe seems to scream at us in a thundering voice: “Purpose and non-randomness!” But all this falls on the deaf ears of many experts in academia who keep summarizing things by telling us, “It's all just randomness.”

With Overwhelming Likelihood, a Random Universe Would Be Lifeless and Light-Less

Shortly after publishing an essay on the topic of cosmic fine-tuning that had some of the worst reasoning I have ever read on the topic (which I discuss here), the Nautilus web site is out with another essay on this weighty topic that I have often discussed on this blog. The new essay by scientist Fred Adams is entitled “The Not So-Fine Tuning of the Universe.” Adams pulls some misleading tricks to try to make you believe his very wrong conclusion that “our universe does not seem to be particularly fine-tuned.”

Here are the main fallacies Adams is guilty of:

• The “ant near the needle hole” fallacy of visually representing something incredibly unlikely to make it look as if it is likely
  
• The fallacy of considering any type of star allowing life when considering stars and cosmic fine-tuning, while not considering the equally important likelihood of stars as suitable for life's evolution as our own sun
  
• The fallacy of considering only less sensitive requirements when considering the likelihood of stars existing, and ignoring a vastly more sensitive requirement which makes the existence of stars incredibly unlikely in random universes
  
• The fallacy of ignoring the universe's most dramatic cases of cosmic fine-tuning, and focusing only on less dramatic cases
  

Adams' scientific specialty is stars. He gives us a graph that plots possible strengths of the electromagnetic force and the gravitational force in hypothetical possible universes. A shaded portion taking up a fairly large part of the graph is described as an area “consistent with life.” The graph makes clear that stars require an unlikely balance between the gravitational force and the electromagnetic force, but from looking at the graph you might think that such a thing wasn't all that unlikely. 

Adams here is guilty of a fallacy that we might call the fallacy of the “ant near the needle hole.” Consider an ant that somehow wanders into your sewing kit. If it were smart enough to talk, the ant might look at the eye of a needle hole in your sewing kit, and say, “Wow, that's a big needle hole!” Such an observation will only be made if you have a perspective looking a few millimeters away from the needle hole. 

 Similarly, Adams has given us a graph in which his “camera” is placed a few millimeters from the needle hole that must be threaded for stars to exist. He has graphed a parameter space in which two fundamental constants vary by only a few times. But physicists routinely deal with a difference of 40 orders of magnitude (10,000,000,000,000,000,000,000,000,000,000,000,000,000), which, for example, is roughly the difference between the strength of the strong nuclear force and the gravitational force. So if we are imagining a parameter space of alternate universes, we must imagine a parameter space vastly larger than the relatively microscopic parameter space Adams has graphed. Rather than just visualizing something like the small changes in the fundamental constants Adams graphs, we should imagine that any of them could vary by a trillion times or a quadrillion times or a quintillion times. 

Given such a parameter space, a realistic visual representation of the chance of a random universe having parameters allowing stars to exist would be one like the visual below, which shows a tiny needle hole somewhere in the Grand Canyon. It is therefore correct to say that with overwhelming likelihood, a random universe would not have stars. Since stars are necessary for both light and life to exist, it is correct to say that with overwhelming likelihood, a random universe would be lifeless and light-less.

 

The misleading nature of Adams' graph is discussed on page 40 of this excellent scientific paper by physicist Luke Barnes, who concludes (contrary to Adams) that “the existence of stable stars is indeed a fine-tuned property of our universe.”

The second fallacy Adams commits is the fallacy of merely considering the likelihood of stars in relation to cosmic fine-tuning, when he should also be considering the likelihood of stars as suitable for life as our own star.

Among the stars in our universe are short-lived blue stars, long-lived yellow stars like our sun, and much less bright “red dwarf” stars that are very long-lived. It could be that life exists on planets around red dwarf stars, but it is almost universally recognized that life is much less probable to arise on planets revolving around such stars. There are two main reasons, discussed fully here. One is that since red dwarf stars are much dimmer, a planet would have to be fairly close to a red dwarf star for life to exist on the planet; and at such closer distances the planet would be subjected to very troublesome tidal effects that might make it uninhabitable. The second reason is that red dwarf stars are more unstable than stars like our sun; as a wikepedia.org article says, “Red dwarfs are far more variable and violent than their more stable, larger cousins,” such as our sun. Such variability would make a planet near a red star much more likely to get zapped by crippling radiation.

So it's kind of like this: yellow stars like our sun are good for the evolution of life, but red dwarf stars are not-so-good (kind of what we may call borderline possibilities). But when considering how much cosmic-fine tuning our universe has, we should consider the odds of getting the best thing we have, not just the odds of getting some “just barely works” borderline possibility. In fact, the requirements for sun-like stars are much more stringent than for red dwarf stars. The physicist Paul Davies says this on page 73 of The Accidental Universe: 

If gravity were very slightly weaker, or electromagnetism very slightly stronger (or the electron slightly less massive relative to the proton), all stars would be red dwarfs. A correspondingly tiny change the other way, and they would all be blue giants.

So we can put it this way: it is incredibly unlikely that a random universe would have any stars, and super-incredibly unlikely that a random universe would have sun-like stars. Clearly we should pay attention to both of these probabilities when judging how fine-tuned the universe is.

I can give an analogy. Suppose you walk deeply into the wooded wilderness of a national park with your friend, and come across a log cabin. You may say, “That must have been fine-tuned” or “That must have been designed.” Now your friend may say, “Not so, because trees might have fallen in such a way to provide you with some type of shelter from the rain.” This is fallacious, because the relevant thing to consider is the most fine-tuned thing you see, not some other less suitable thing that luck might have given you. And similarly, when considering fine-tuning in regard to stars, we should be noting that the requirements of the most suitable types of stars (stars like our sun) are much, much more stringent than the requirements of “some type of stars.” Adams ignores these more stringent requirements.

The third fallacy Adams commits is the fallacy of considering only some of the less stringent requirements of stars, while ignoring the most stringent requirement for stars. The most stringent requirement of stars is that the proton charge exactly balance the electron charge. This requirement has been pointed out by the astronomer Greenstein, who pointed out that no stars could exist if the proton charge did not exactly match the electron charge.

If there was a very small difference between the electron charge and the proton charge, you would either have (1) an electrical imbalance between particles which would completely overwhelm gravity, making it impossible for stars to hold together, or (2) an electrical imbalance between particles that would completely preclude the possibility of the thermonuclear reactions we observe in stars.

In our universe each proton has a mass 1836 times larger than each electron, but the charge of the proton exactly matches the charge of the electron to at least eighteen decimal places, as measured here (the only difference being that the proton has a positive charge and the electron has a negative charge). Stars could not possibly exist if this precise fine-tuning did not exist. Adams has simply ignored this ultra-stringent requirement, focusing on less stringent requirements. Were he to consider this requirement, he might realize that stars are trillions of times less probable to exist in random universe than he imagines.

I may note that this requirement is an entirely different requirement than the one previously considered. So for a random universe to have stars, it must not only “thread the needle” involving the balance of the gravitational and electromagnetic force (the balance that Adams has considered), but a random universe would also have to “thread the microscopic needle” of having the proton charge exactly match the electron charge. So it is as if the arrow of the blind archer must hit not just one very distant bulls-eye for stars to exist, but two very distant bulls-eyes.

We are then doubly justified in saying: with overwhelming likelihood, a random universe would be both lifeless and light-less.

The fourth fallacy that Adam commits is the fallacy of ignoring the universe's most dramatic cases of fine-tuning, and focusing only on less dramatic cases. The three most dramatic cases of cosmic fine-tuning all seemingly involve fine-tuning more precise than 1 part in 1,000,000,000,000,000,000,000,000. They are:

• the exact match of the absolute magnitude of the proton charge and the electron charge, to more than 18 decimal places
• the fine-tuning of the vacuum energy density, discussed here, by which we have a cosmological constant more than 10⁵⁰ times smaller than the amount predicted by quantum field theory (such as we would have if opposing parameters of nature accidentally canceled out each other to more than fifty decimal places)
• the fine-tuning of the universe's initial expansion rate (in which the universe's initial critical density matched the actual density to something like 1 part in 10⁵⁰).

Which of these does Adams discuss in his Nautilus essay? None of them. Of course, he does not want to discuss such things as they would obliterate his claim that “our universe does not seem to be particularly fine-tuned.” 

Adams is very well aware of the cosmological constant problem (also known as the vacuum density problem and the “vacuum catastrophe” problem), because he discusses it at length in a scientific paper he co-authored. There he gives us some reasoning that is as off-the-mark as his insinuations about the likelihood of accidental universes having stars.

The issue in regard to the cosmological constant is that quantum field theory predicts the cosmological constant should be 10⁶⁰ or 10¹²⁰ times larger than the value we observe. This prediction (which you can find discussion of by doing a Google search for “worst prediction in the history of physics”) is that the vacuum of space should be super-dense – much denser than steel. But the actual vacuum of space has very little energy or density – it's almost empty.

We know that life could never exist if the vacuum was anything like that predicted by quantum field theory. Obviously you can't have life if the space between a star and a planet is thicker than steel – light cannot even travel through that. But an interesting question is: by how much could the cosmological constant differ from its current value and still allow life to exist?

Adams concludes that the cosmological constant could be up to 10³⁰ times larger and still allow life to exist. This is almost certainly a far-too-generous estimate, and other estimates have estimated much greater sensitivity. He uses this estimate to support a conclusion in the paper that “the universe is not overly fine-tuned.” But he should be reaching exactly the opposite conclusion from these facts. If the cosmological constant is supposed to be 10⁶⁰ or 10¹²⁰ times larger than the value we observe because of quantum considerations, and  a value 10³⁰ times larger than the observed value would have prevented life, then how much luck did we have in this regard to have a habitable universe? The answer is: luck with a probability of about 1 part in 10³⁰ or 1 part in 10⁹⁰. Adams should have reached the conclusion that the universe is astonishingly fine-tuned, in a way that less than 1 universe in a billion trillion should have by chance.

Adams also gives some misinformation about the fine-tuning issue involving nuclear resonances and the triple-alpha process, a process by which stars produce energy. He claims that this fine-tuning issue “goes away,” because there's some particular way in which an alternate physics could allow carbon to exist. He's using some fallacious reasoning he uses in this scientific paper. The fine-tuning issue involving the triple-alpha process and resonances is that the physics of the universe must be fine-tuned for both carbon and oxygen to exist in abundant qualities, as it does in our universe. But in his paragraph claiming a way to make this fine-tuning “go away,” he does not discuss oxygen. And on page 26 of his paper, he says, “This set of simulations does not include nuclear reactions that produce oxygen, neon, and heavier elements.” So he cannot truthfully claim to have made this fine-tuning issue “go away.” The difficulty is explaining how a random universe could have abundant amounts of both oxygen and carbon, not just carbon.

This fine-tuning requirement is correctly stated in a 2014 scientific paper which tells us on page 16 that in order for you to have abundant quantities of oxygen and carbon, you need for the quark masses to be within 2 to 3 percent of their current values, and you also need for the fine-structure constant to be within 2.5% of its current value. You could therefore say nature has to hit two different “holes in one,” and these aren't the only “holes in one” nature has to hit in order to end up with intelligent life. Because these two “holes in one” that nature must hit are different from the two other “holes in one” I discussed before, while discussing stars.

Another bit of sloppy thinking Adams gives in his Nautilus essay is when he attempts to explain away a fine-tuning of the strong nuclear force by claiming that if some alternate physics were true,  "The longest-lived stars could shine with a power output roughly comparable to the sun for up to 1 billion years, perhaps long enough for biological evolution to take place."  This is laughable, since earthly life is believed to have required 3.5 billion years to have appeared; and obviously a universe in which stars like ours can burn brightly for 10 billion years is greatly preferable to one in which they can only burn for 1 billion years.  Again, I may note that you do not explain a more favorable case of fine-tuning by imagining some much less favorable situation requiring less fine-tuning.

In his Nautilus essay, Adams misreads what nature is telling us, and his conclusion that “our universe does not seem to be particularly fine-tuned” is very much at odds with both the facts and the statements of numerous other scientists with a variety of philosophical standpoints, who have again and again stated the opposite. 

Postscript: I may note based purely on Adam's graph plotting the electromagnetic force versus the gravitational force and a life-compatible region, and the fact that the potential parameter space in random universes is more than a billion trillion times larger than the parameter space he has graphed, we should conclude that the chance of stars in a random universe is less than 1 in a billion trillion (less than 1 in 1,000,000,000,000,000,000,000).  The requirement of the proton charge matching the electron charge is simply a second reason for drawing the same conclusion. 

An Analysis of the Recent Claim the Solar System Is in a “Unique Area of the Universe Just Right for Life”

Imagine if some huge extraterrestrial spaceship were to appear in a fixed position above some US city. Suppose the extraterrestrials wanted to get started communicating with us. How could they start the conversation, if their language was so different from ours that English was utterly unintelligible to them? One way would be for them to place 1836 identical small objects in a field. Every physicist would understand the meaning of this. 1836 is the ratio between the proton mass and the electron mass, a constant throughout the universe.

Or if the extraterrestrials wanted to do something similar that wouldn't require so many objects, they could place 137 identical small objects on a field. Every physicist would recognize what this meant. 137 is the number associated with a universal constant of nature known as the fine-structure constant. Its value is normally represented as 1/137 (or more exactly, 0.007297351). The behavior of stars crucially depends on the value of the fine-structure constant.

A few days ago the Daily Galaxy web site had an article involving the rather prosaic topic of the fine-structure constant. Following the Daily Galaxy's standard rule of “spice things up to the max,” the article had this sensational title: Our Solar System “Is In a Unique Place in the Universe – Just Right for Life.”

Such a title must have excited those who like to believe the egotistical idea that man is the centerpiece of the universe. But the facts cited by the Daily Galaxy story do not warrant the article's sensational title implying something special about the position of our solar system.

The article in question refers to some research published in 2012 by John Webb and his colleagues at the University of New South Wales. The relevant scientific paper can be found here. Studying the fine-structure constant (a fundamental constant generally believed not to vary in time or space), the scientists claimed to find evidence that the fine-structure constant “increases with increasing cosmological distance from Earth.”

But the variation reported was only about 1 part in 100,000. There is probably insufficient basis for thinking that a variation of only 1 part in 100,000 in the fine-structure constant would rule out the habitability of a particular region.

There are some reasons for thinking that stars like the sun could not exist if the fine-structure constant were much larger or smaller. The fine-structure constant controls the strength of electromagnetism. On page 73 of his book The Accidental Universe, Paul Davies states the following:

If gravity were very slightly weaker, or electromagnetism very slightly stronger, (or the electron slightly less massive relative to the proton), all stars would be red dwarfs. A correspondingly tiny change the other way, and they would all be blue giants.

But we see yellow stars like the sun all over the galaxy, and in many other nearby galaxies. So a space-dependent variation of 1 part in 100,000 cannot justify any claim that our solar system is in a “unique place in the universe – just right for life,” not unless you mean “place” to mean some large fraction of the universe.  The problem with such a claim is not the "just right for life" part, but the "unique" part implying some special zone of habitability in just one part of the universe.

 Bubble around a bright star (Credit: NASA)

There has been other research on the fine-structure constant that does not agree with that of Webb and his colleagues. A more recent paper (published in June 2016) found no evidence for variation in the fine-structure constant, not even 3 parts in a million.

So the Daily Galaxy's article title seems to be unwarranted. Another interesting result on the fine-structure constant was reported in 2016 in a scientific paper by scientist McCullen Sandora. Sandora dealt with the “inverse fine structure constant,” which is the fine-structure constant divided by 1 (this has been measured to be 137.036). The iron lying around our planet (needed for technical civilizations) is believed to have arisen in the core of a distant star (stars shoot out iron when they explode in supernova explosions). Sandora found that for stars to produce iron, the inverse fine-structure constant must have a value of 145, give or take 50. 

Sandora also found a more sensitive requirement, finding that for a planet to have plate tectonics like the Earth, the inverse fine-structure constant must be 145, give or take 9. Sandora gives some complicated reasons why such plate tectonics are a requirement for the appearance of creatures such as us. 

The latter finding puts the measured value of the inverse fine-structure constant (137.036) just barely inside the range consistent with a planet like Earth (a range between 136 and 154). This finding is consistent with the claim in this scientific paper, which says that an inverse fine structure constant “close to 137 appears to be essential for the astrophysics, chemistry and biochemistry of our universe.”

The fine-structure constant is actually derived from three other fundamental constants of nature. The formula for the fine structure constant is that it is equal to e²/hc, where e is the charge of the proton, h is Planck's constant, and c is the speed of light.

According to Sandora, planets just like ours (with plate tectonics) could not exist if the fine-structure constant varied by more than 6%. If the fine structure constant must fall in a very narrow range, then think of how fine-tuned the proton charge must be, if the fine structure constant depends on the square of the proton charge.

This is only one way in which the proton charge must be exquisitely fine-tuned. There is the additional fact (involving a far-greater sensitivity) that planets will not hold together unless the proton charge and the electron charge match each other to many decimal places (the only difference being that the electron charge is negative). For if there were not so precise a match (far more unlikely than you randomly guessing correctly someone's Social Security number), the electromagnetic force (more than a trillion trillion trillion times stronger than the gravitational force) would cause repulsion exceeding the gravity holding the planet together (as mentioned here). Experiments have shown that the proton charge and the electron charge do actually differ by less than 1 part in 1,000,000,000,000,000,000. This fact is unexplained by our physicists, and is extremely surprising given that each proton has a mass 1836 times greater than each electron.

We therefore have hints some very precise fine-tuning went on here, although we have no adequate reason for thinking that it is some special blessing applying only to our local region of the universe. 

Scientific Materialism Makes the Wrong Prediction About Our Universe's Habitability

In my previous post I discussed cosmic habitability categories, which involve four possible types of universes: uninhabitable universes (in which life can't exist), barely habitable universes (in which it is very hard but just barely possible for intelligent life to exist), moderately habitable universes (offering more favorable conditions), and abundantly habitable universes (in which life might be able to evolve all over the universe, with many planets having life all over them, and intelligent life having great prospects for being able to survive for eons). It seems that our universe is the fourth type of universe, as it does not have any serious shortfall in regard to habitability.

Now let us consider two interesting questions: (1) which of these types of universes are the most likely and the second-most-likely to exist? (2) what type of prediction about the habitability of the universe is implied by scientific materialism?

In my previous post I described a group of habitability necessities that are required for any universe to be habitable, and I also listed a series of factors I called habitability boosters, each of which would increase the habitability of a universe (without being an absolutely necessary precondition for the habitability of a universe). I then used these factors to define the different habitability categories:

Uninhabitable universe: A universe in which intelligent life cannot evolve anywhere, because it is missing one or more of the habitability necessities.

Barely habitable universe: A universe that has all of the habitability necessities, but none or only one or two of the habitability boosters.

Moderately habitable universe: A universe that has all of the habitability necessities, and roughly half of the habitability boosters.

Abundantly habitable universe: A universe that has all of the habitability necessities, and all or almost all of the habitability boosters.

So to delve into the relative likelihood of these types of universes, we must consider first : what is the chance of the habitability necessities occurring? Then we can consider what is the chance of the habitability boosters occurring.

Why a Random Universe is Overwhelmingly Likely To Be Uninhabitable

The first habitability necessity I mentioned was stable atoms heavier than hydrogen. We take heavy elements such as carbon and oxygen for granted, but we shouldn't. We should not expect them to exist in more than a very tiny fraction of all random universes. You wouldn't have atoms other than hydrogen unless you have the strange convenience we call the strong nuclear force, which binds together nuclei together, overcoming the electromagnetic repulsion between protons. First such a force must exist. Second, it must have the right strength level (and it is actually the strongest known force). You must also have electromagnetism causing a force of attraction between protons and electrons, which keeps electrons in an atom. Then you need quantum mechanical laws that prevent such attraction from causing electrons to fall into the nucleus. Given all of the ways you can wrong, it seems the chance of atoms existing in a universe of random constants and forces is very low.

The second habitability necessity I mentioned was planets with a reasonable level of gravity. To meet this necessity a universe needs a universal force of gravitation that is attractive. The very existence of such a force would seem to be no more than a one-in-three likelihood, since we can imagine two other equally likely possibilities (a universe with no such force at all, and a universe with a force of repulsion between all particles). But the likelihood of habitable planets in a random universe is actually much, much smaller than that. For one thing, the strength level of gravitation (signified in our universe by the gravitational constant) must be within a quite narrow range of values. If gravitation is too weak, planets won't hold together. If gravitation is too large, then the gravity on all planets will so great that no animals will be able to move around on a planet (and there are also reasons why an expanding universe would have collapsed into black holes if gravitation had been much higher). There is also fine-tuning required in regard to the proton charge and the electron charge. For example, in our universe if the proton charge and the electron charge were not exactly the same, gravitation would not be enough to hold planets together (since the electromagnetic force is roughly a trillion trillion trillion times stronger than the gravitational force, even a relatively tiny difference in the proton charge and the electron charge would cause repulsive effects exceeding the attractive effects of gravitation in large bodies such as planets, preventing their existence, as mentioned by Greenstein here).

In short, while we take planets for granted (having lived on one all our lives), it seems that we should expect only a tiny fraction of random universes to have planets suitable for the existence of mobile living creatures

The likelihood of a random universe being habitable seems even smaller when we consider the third habitability necessity I mentioned, the necessity of having a relatively empty vacuum. The issue (discussed here) is that according to quantum mechanics, quantum fluctuations should cause the vacuum to be teeming with energy. This is the “vacuum catastrophe” problem or cosmological constant problem that is perhaps the biggest unsolved problem in physics. According to the predictions of quantum field theory, we should live in a vacuum that is at least 10⁶⁰ times denser than the observed vacuum – so dense that a square meter of the vacuum should be denser than a square meter of steel. Pretty much the only idea physicists have as to why our vacuum is so relatively empty is that there was some fantastically improbable and coincidental “cancellation of contributions” leaving us with a nearly empty vacuum – something rather like the annual savings of Chinese citizens coincidentally matching the annual credit card charges of US citizens, with an exact match to the penny. The chance of such a thing in a random universes is very, very low.

The likelihood of a random universe being habitable seems even smaller when we consider the fourth habitability necessity I mentioned, the necessity of having both carbon and oxygen in the universe. Scientists have discussed how if the strong nuclear force had been slightly weaker or slightly stronger, we would have been left with a universe that would have had either lots of carbon but no oxygen, or lots of oxygen but no carbon. Apparently getting both required a lot of luck that would be very unlikely in most random universes.

Based on these considerations (which do not at all discuss all of the habitability necessities of a habitable universe), we can conclude that uninhabitable universes are vastly more likely than habitable universes. Such a conclusion has been made by quite a few previous scientists. A recent article by physicist Luke Barnes has a relevant graph showing habitable universes as just a small portion of a parameter space that is much bigger (and there are lots of bulls-eyes that nature must hit for a universe to be habitable, not just the one illustrated here).

Why a Barely Habitable Universe Should Be Vastly More Likely Than a Moderately Habitable Universe Or an Abundantly Habitable Universe

The conclusion above has been made by many writers, but now let's look at a question rarely considered, but quite important: in the class of all habitable universes, what fraction should be we expect to be just barely habitable? In other words, should we expect that barely habitable universes are vastly more common than moderately habitable universes and abundantly habitable universes?

I will now argue that we should expect exactly that, mainly because the habitability boosters that I identified are unlikely to occur in random universes. Let's look at the first habitability booster I identified, the existence of radiant stars.

The likelihood of you getting radiant stars in a random universe is discussed in section 4.7 of the scientific paper here. The paper quotes a scientific paper by Adams mentioning a 1 in 4 chance of stars being possible if you allow the fine-structure constant and the gravitational constant to have values differing from their current values by ten times. But this is an example of “putting the camera near the needle hole in order to make the needle hole look big.” There's no reason why the the fine-structure constant and the gravitational constant could not have values a million times smaller or larger. When we properly consider that, we are then left with a probability of less than 1 in a million that a random universe would have radiant stars. See here for more on this issue. On page 40 of this paper, physicist Luke Barnes says, “We conclude that the existence of stable stars is indeed a fine-tuned property of our universe” – in other words, something that would be very unlikely to occur in a random universe.

Another habitability booster I mentioned is the existence of sun-like stars. A universe that has such stars will tend to be a lot more habitable than one merely having red stars (planets around red stars are predicted to be tidal-locked planets on which there is only a ring of habitability between the side facing the star and the opposite side). It turns out that the fine-tuning for sun-like stars is far greater than the fine-tuning needing for red stars. Below is a quote from page 73 of The Accidental Universe by physicist Paul Davies:

If gravity were very slightly weaker, or electromagnetism very slightly stronger, (or the electron slightly less massive relative to the proton), all stars would be red dwarfs. A correspondingly tiny change the other way, and they would all be blue giants.

It seems, therefore, that in random universes we are extremely unlikely to see sun-like stars, and that the requirements for such stars are much more special (much greater “long shots”) than the requirements for stars in general, just as the requirements for getting into Harvard are much harder-to-meet than the requirements for getting into “some type of college.”

Another habitability booster I mentioned is the existence of large amounts of both carbon and oxygen. Scientists have identified this as something that would not occur unless fundamental constants are fine-tuned. According to page 41 of this paper, a 1 part in 100,000 change in one fundamental constant would change things so that the main stellar process producing carbon and oxygen would produce either carbon or oxygen, but not both. That paper concludes, “The ability of stars in our universe to produce both carbon and oxygen seems to be a rare talent.” So we can conclude that this habitability booster (an abundance of both carbon and oxygen) is highly improbable in a random universe.

Another habitability booster I mentioned is low radioactivity. For simplicity let's just assume there is maybe 1 chance in 2 of such a condition. It would seem to be many times harder for a universe to have the last habitability booster I mentioned, that of low static electricity (so there are not all kinds of lethal static electricity amounts hanging around all over the place, ready to kill anyone who touches them). Low static electricity seems to require two different coincidences: the coincidence that the number of protons in a universe roughly equals the number of electrons (as it seems to do in our universe), and the coincidence that the proton charge equals the electron charge (as it does in our universe, to twenty decimal places). If you change those conditions just a little, you will be left with a universe in which there is so much free-floating static electricity (excess charges floating about) that life should be very rare, very short-lived or both (imagine a planet teeming with billions of “static electricity landmines” and you'll get the idea).

So speaking very generally, not only are the habitability necessities rare strokes of luck that should be very unlikely to occur in a random universe, but also the habitability boosters are almost all rare strokes of luck that should be very unlikely to occur in a random universe. Consequently, barely habitable universes should be vastly more likely than moderately habitable universes or abundantly habitable universes. Barely habitable universes should be much more likely because they require much fewer “improbable strokes of luck” than moderately habitable and abundantly habitable universes.

The visual below illustrates this idea. This is a very schematic visual, and its proportions are not supposed to represent the actual ratio between different habitability categories. The visual refers merely to probabilities, not actualities.  In the first bar we see something that represents very roughly a ratio between uninhabitable universes and habitable universes (although the actual fraction of habitable universes should be much smaller). The second bar is a closeup of the right edge of the first bar. When we zoom in and look at the habitable universes, we find that almost all of them are barely habitable universes, with a few (on the right side) being moderately habitable. The third bar is a closeup of the right edge of the second bar. When we zoom in and look at the universes that are better than barely habitable, we find that almost all of them are moderately habitable and only a tiny fraction are abundantly habitable. Although this visual is highly schematic, I think it gives a rough idea of the relative probabilities of a random universe being uninhabitable, barely habitable, moderately habitable or abundantly habitable.

What Prediction Does Scientific Materialism Make About Our Universe's Habitability?

Now let us consider: what type of prediction does scientific materialism make about the habitability of our universe? The answer is: it makes a prediction that could not be more wrong.

The actual prediction that scientific materialism makes about the habitability of universe is that our universe should be about the most uninhabitable universe imaginable. This is because of the long-standing problem in physics known as the cosmological constant problem or the vacuum catastrophe problem. Because of weird quantum mechanical considerations, physics predicts the vacuum of space should be seething with a very dense sea of virtual particles, particles that should cause each cubic meter of space to have more mass-energy than solid steel. Under such conditions, no type of life could exist for even an instant – it would be easier for life to exist in the middle of the sun.

So what we get from scientific materialism is the prediction that the universe should be as uninhabitable as anything we can imagine. But suppose we grant a special favor, and simply ignore the predictions of quantum mechanics. Suppose we pay no attention to the whole cosmological constant problem and vacuum catastrophe issue that physicists have been puzzled by for forty years. What type of universe does scientific materialism then predict? It then still predicts that our universe should be an uninhabitable universe. This is simply because an uninhabitable universe should be trillions of times more likely than any type of habitable universe. That's because of all the extremely improbable long shots and coincidences for a universe to meet the habitability necessities I have mentioned (and others I haven't mentioned).

But what if we grant a second special favor, and assume that observers must exist in a universe, perhaps by using some kind of dubious “selection effect” reasoning or “anthropic principle” reasoning. There is no sound basis for granting such a favor, but suppose we grant it anyway. What then does scientific materialism predict? It then predicts that our universe should only be a barely habitable universe. Why? Because, as we have seen, barely habitable universes should be vastly more likely than abundantly habitable universes like the one we live in. The list of long shots and coincidences that must be met in order to have a barely habitable universe is much shorter than the list of long shots and coincidences that must be met for moderately habitable universes or abundantly habitable universes.

So even if we grant two special favors, scientific materialism still makes the wrong prediction about what type of universe our universe should be. But what if we throw in a multiverse – the assumption that there are many universes? Does that help? No, it doesn't help at all. The habitability predictions of scientific materialism regarding our universe are not changed at all if we assume that there are many universes. It is a basic fact of probability math (ignored by multiverse enthusiasts) that you do not increase the chance of success on any one random trial by increasing the number of random trials.

The predictive failure of scientific materialism in this regard is very spectacular. It's a predictive failure far worse than has ever been made by any errant gypsy fortune teller or any misguided apocalyptic preacher. A failure this spectacular is a sure sign of underlying false assumptions. What we need is a worldview that predicts that our universe should be a type of universe like the type that it is, an abundantly habitable universe. 

Cosmic Habitability Categories: Four Types of Universes

When we hear scientists talk about different types of universes, they are usually talking about the spatial geometry of the universe, and distinguish between a flat universe, an open universe and a closed universe. But there is another very interesting way to classify universes. We can classify universes based not on their geometry but on their habitability – how easy it is for life to develop in a universe. We can distinguish between universes that are abundantly habitable, moderately habitable, barely habitable and uninhabitable.

Before presenting such a classification, let's look at two types of things that can contribute to a universe's habitability. The first type of thing is what can be called habitability necessities – things that a universe must have in order for any life to exist in it. The second type of thing is what can be called habitability boosters. By “habitability boosters” I mean things that are not absolutely necessary for any type of life to exist in a universe, but things which will tend to make life more common and prevalent and long-lasting if they exist in a universe.

The Main Habitability Necessities

Let's look at some habitability necessities – things that absolutely must be present for any advanced life to exist in a universe.

One habitability necessity is stable atoms heavier than hydrogen, atoms such as carbon and oxygen. We take stable atoms for granted, but quite a few things have to go right in order for them to be possible. In order for you to have elements other than hydrogen, you need to have a strong nuclear force that binds protons together in the nucleus. Such a force must be very strong to overcome the electromagnetic repulsion between protons (all particles with the same charge repel each other). Another requirement of stable atoms other than hydrogen is an electromagnetic force, which keeps electrons orbiting around the nucleus of the atom. If you don't have such a force, or if electrons and protons have the same type of charge (both positive or both negative), or if the electron charge differs greatly from the proton charge, you cannot have atoms such as oxygen atoms and carbon atoms. Another requirement for stable atoms and stable molecules are certain quantum mechanical laws such as the Pauli exclusion principle. As mentioned here, if there were no Pauli exclusion principle there would be no chemistry.

Another habitability necessity is the existence of large bodies such as planets, with moderate levels of gravity on their surface. This requires a universal force such as gravitation. This force must be strong enough to hold planets together, but not so strong that organisms living on the planet have to endure a crushing force that always keeps them pinned in the same place on the ground. So a habitable universe needs not just a universal force of gravitation, but one that is neither too large nor small.

Another habitability necessity is a relatively empty vacuum. By this I simply mean a vacuum that has less mass-energy than solid steel. This is something we take for granted, but (as discussed here) there are physics considerations that imply such a thing should be incredibly unlikely. Strangely, quantum field theory predicts that there should be all kinds of quantum contributions to the vacuum that should cause it to be incredibly dense with mass-energy. This is an unresolved problem of physics known as the cosmological constant problem or the “vacuum catastrophe” problem.

Another habitability necessity is the existence of both carbon and oxygen in adequate amounts. As far as we know, life could not exist without either one. When physicists imagine universes with greatly different physics, particularly a strong nuclear force much stronger or weaker, it often means a universe with lots of carbon and no oxygen, or lots of oxygen and no carbon.

This is not a complete list of habitability necessities, but is enough to clarify the concept.

The Main Habitability Boosters

Now let's look at some habitability boosters – things that are not absolutely necessary for life to exist in a universe, but things that will tend to make life much more widespread and long-lasting if they do exist. The first habitability luxury I can think of is radiant stars – stars that produce light and heat.

It may surprise you that I have classified radiant stars as a habitability booster rather than a habitability necessity. How could life exist without stars? But the benefit that stars or suns supply is light and heat, and a planet might have light and heart without any radiant star near by. Volcanic activity, geological activity and tidal effects can produce light and heat, such as we see on Jupiter's moon Io. 

 

We can actually imagine intelligent life evolving on a small number of planets in a universe that had no radiant stars. It would require a rare type of planet which had volcanic activity or geological activity or tidal activity that consistently produced heat and light over many millions or billions of years. Even though there would be probably less than one planet in a thousand that would have such characteristics, there would still be quite a few such planets in a universe with trillions of planets.

But it could be argued that such planets could not exist, because carbon and oxygen are formed in radiant stars. However, even if there were no radiant stars there would probably be rare. freak events that would cause carbon and oxygen to be created in rare spots – events such as collisions of large astronomical bodies.

It has been estimated that the total number of stars in the observable universe is something like 10 to the twenty ninth power. Let's imagine an alternate universe in which heavy elements such as carbon and oxygen only form from freak events such as collisions of large astronomical bodies. That would still leave you with trillions of planets that might have heavy elements such as oxygen and carbon. If you then imagine no radiant stars, and life only forming on planets that gave off heat and light through geological activity, you would still have a few hundred, thousand or million such planets (possibly even billions).

So we must classify radiant stars as a habitability booster rather than a habitability necessity. There is a related thing that we can classify as a stronger and more specific habitability booster: the existence of sun-like stars. It is believed that intelligent life might evolve on planets revolving around small red stars. But it is believed that if a planet existed in the habitable zone of a red dwarf star, the planet would be so close to the star that it would keep the same side pointed towards the star, without rotation. This would probably limit life to existing in a ring-like area of the planet, between the side facing the star, and the side facing away from it. If a universe has not just red dwarf stars but also sun-like stars, it will tend to be more habitable, with more life (all other things being equal). Planets revolving around sun-like stars can have life existing all over them, not just in a narrow ring between the front and the back of the planet. 

Another thing that must be classified as a habitability booster is the presence of large amounts of both carbon and oxygen. Having lots of carbon and oxygen around may be necessary for a universe with a huge amount of life. But for a universe to be barely habitable, with only a tiny amount of life, it needs only to have a few lucky spots where there is a decent amount of carbon and oxygen.

Another thing we can list as a habitability booster is low radioactivity. In our universe radioactivity has a negligible effect on habitability, because only rare very heavy elements such as uranium are radioactive. But we can imagine a universe in which the strong nuclear force was much weaker. In that case most elements would be radioactive. The effect would probably be that creatures such as us could not live longer than about 20 or 25 years before dying of cancer caused by radioactivity.

Another thing we can list as a habitability booster is low radiation from sources such as gamma ray blasts and supernova explosions. We can easily imagine a universe a little different in which there would be a high chance of any newly evolved intelligent species being wiped out by gamma ray blasts or supernova explosions, within a few million years of when it appeared.

Another thing we can list as a habitability booster is a low static electricity. This is something that we take for granted, but which is extremely unlikely in random universes. We have low amounts of static electricity because the number of protons in the solar system is roughly equal to the number of electrons, and the charge on the proton (1836 times more massive than the electron) is the exact opposite of the charge on the electron. But if such coincidences did not exist, we might live on a planet that was teeming with local charge imbalances -- lethal concentrations of static electricity. On such a planet it might be very common for organisms to be killed when a creature simply stepped on a rock with enough excess electrons to cause a lethal shock.

Four Types of Universes

Having listed these types of habitability necessities and habitability boosters, it is now easy to categorize four types of universes. They are as follows:

Uninhabitable universe: A universe in which intelligent life cannot evolve anywhere, because it is missing one or more of the habitability necessities.

Barely habitable universe: A universe that has all of the habitability necessities, but none or only one or two of the habitability boosters.

Moderately habitable universe: A universe that has all of the habitability necessities, and roughly half of the habitability boosters.

Abundantly habitable universe: A universe that has all of the habitability necessities, and all or almost all of the habitability boosters.

Let's imagine some universes, and then classify them as belonging to these four types.

Universe 1: There are no sun-like stars, but many red dwarf stars. In almost all solar systems in which a life-bearing planet revolves around a red dwarf star, the planet keeps the same side always pointing toward the star, and life exists in a narrow band between that side and the other side of the planet. There's also a lot more gamma ray bursts than in our universe.

What type of universe is this? It seems like a moderately habitable universe.

Universe 2: There are no radiant stars at all, and the night sky always looks dark. Carbon and oxygen are rare. But in certain rare places some freak events such as astronomical collisions led to local abundances of carbon and oxygen that eventually became planets. In a small number of these planets, special geological conditions created enough light and heat for intelligent life to evolve. But the future prospects are dim for such life forms, since a change in geological conditions might deprive them of the heat and light they need.

What type of universe is this? It seems like a barely habitable universe.

Universe 3: There are radiant stars, and countless stable planets. There are not just red stars, but also stars like the sun. There are no habitability factors that should limit the universe from having trillions of planets bearing intelligent life. Planets typically enjoy low amounts of harmful radiation, low radioactivity, and low amounts of static electricity. There are trillions of planets on which nothing physical prevents intelligent life from existing for billions of years.

Which type of universe is this? It's an abundantly habitable universe.

Which type of universe do we live in? Each of the habitability boosters I previously listed are conditions of our universe. And obviously our universe has all of the habitability necessities, or we wouldn't exist. So we must classify our universe as an abundantly habitable universe.

Recent news stories bolster this conclusion. A significant fraction of the universe's galaxies are rather spherical-shaped elliptical galaxies different from our own spiral galaxy. It used to be believed that elliptical galaxies must be lifeless, because of a lack of heavy elements. But recently scientists concluded that large elliptical galaxies can produce up to 10,000 times as many Earth-like planets as our galaxy. It seems, in fact, that all of the three major types of galaxies in our universe (spiral, irregular, and elliptical) can support planets with life. The Kepler telescope has helped confirm that there are planets all over the place in our galaxy. We know of very few or no habitability shortfalls in our universe, so it must be classified as abundantly habitable.

But what type of universe should we expect our universe to be? This is a fascinating question with some interesting philosophical implications. In my next post I will discuss this question, discussing the relative probabilities of getting the types of universes I have listed. I will show that conventional assumptions like those made by most scientists lead to shockingly erroneous predictions about the type of universe our universe should be. 

As I will show in my next post, without the cheat of assuming there must be an observer, such assumptions lead to the prediction that our universe should be uninhabitable. Even if one makes such a cheat, by assuming an observer, such assumptions lead to the prediction that we should live in a barely habitable universe much, much less favorable to life than the one we live in.