Cosmological Natural Selection Theory Gets Even More Falsified

Scientists have long been bothered by why the physical conditions, laws and fundamental constants of the universe seem to be so fine-tuned to allow the existence of planets such as ours and living beings such as us. On page 235 of his book Chaos and Harmony, a University of Virginia professor of astronomy (Trinh Xuan Thuan) stated this:

"The evolution of the cosmos is determined by initial conditions (such as the initial rate of expansion and the initial mass of matter), as well as by fifteen or so numbers called physical constants (such as the speed of the light and the mass of the electron). We have by now measured these physical constants with extremely high precision, but we have failed to come up with any theory explaining why they have their particular values. One of the most surprising discoveries of modern cosmology is the realization that the initial conditions and physical constants of the universe had to be adjusted with exquisite precision if they are to allow the emergence of conscious observers. This realization is referred to as the 'anthropic principle'...Change the initial conditions and physical constants ever so slightly, and the universe would be empty and sterile; we would not be around to discuss it. The precision of this fine-tuning is nothing short of stunning. The initial rate of expansion of the universe, to take just one example, had to have been tweaked to a precision comparable to that of an archer trying to land an arrow in a 1-square-centimeter target located on the fringes of the universe, 15 billion light years away!"

One excellent book is the rather poorly titled book “Modern Physics and Ancient Faith” by Stephen M. Barr, a physics professor at the University of Delaware (which doesn't at all brush away religious thinking as an ancient relic, despite the title). In that book there is an interesting discussion of “anthropic coincidences” that are necessary for our existence. One example given is that of a parameter called v. On pages 126-127 the book makes these interesting comments:

"The long technical name of the parameter v is 'the vacuum expectation value of the Higgs field.'....The value of v is a great puzzle to particle theorists; in fact, it is one of the central puzzles of physics. What is puzzling is that in reasonably simple theories v seems to want to come out to be, not 1, but a number like 10¹⁷, i.e, 100,000,000,000,000,000...As far as the possibility of life emerging in our universe is concerned, it would be a disaster for v to be 100,000,000,000,000,000. It would also be a disaster if it were 100,000,000,000,000, or if it were 100,000,000, or if it were 100,000, or if it were 100. Indeed, it would be a disaster if it were 10, or 5, or even 1.5. It would probably be a disaster if v were even slightly different from the value it happens to have in the real world."

So nature “hit the bullseye,” a very distant bullseye, it would seem. This is only one of many astonishing “coincidences” required for our existence. Barr lists seven other such cases, one of which is even more dramatic: the fine-tuning of the cosmological constant. As Barr puts it on page 130 of his book:

"In order for life to be possible, then, it appears that the cosmological constant, whether it is positive or negative, must be extremely close to zero – in fact, it must be zero to at least 120 decimal places. This is one of the most precise fine-tunings in all of physics."

It would be very hard to overestimate how thoroughly all major objects in our universe depend upon the fundamental constants being just right. It is not merely that the existence of extremely organized things such as mammals depends on a fine-tuning of fundamental constants. It is also that the existence of objects such as stars and planets depend on such a fine-tuning.  On pages 64-65 of his book "The Symbiotic Universe," astronomer George Greenstein (a professor emeritus at Amherst College) said this about the equality of the proton and electron charges (which have precisely the same absolute value): 

"Relatively small things like stones, people, and the like would fly apart if the two charges differed by as little as one part in 100 billion. Large structures like the Earth and the Sun require for their existence a yet more perfect balance of one part in a billion billion." 

In fact, experiments do indicate that the charge of the proton and the electron match to eighteen decimal places. Because of the dependency of stars on a very delicate fine-tuning of fundamental constants, you can state it this way: a random universe would be both lifeless and lightless. 

In an attempt to explain such things, physicist Lee Smolin has long advanced a groundless theory he calls  cosmological natural selection, one that no one seems to advance other than himself. It's a theory of a cyclical universe in which the laws of the universe change in each cycle.

 In his book Time Reborn, Smolin describes the theory as follows:

"The basic hypothesis of cosmological natural selection is that universes reproduce by the creation of new universes inside black holes. Our universe is thus a descendant of another universe, born in one of its black holes, and every black hole in our universe is the seed of a new universe. This is a scenario within which we can apply the principles of natural selection."

Smolin claims to have a theory of how the physics of the universe could evolve through natural selection. But how on earth can we get anything like natural selection out of the idea of new universes being created by the formation of black holes? Smolin gave the following strained reasoning: (1) he claimed that the physics that favors a habitable universe are similar to the physics that favor the production of black holes; (2) he claimed that a new universe produced by a black hole might have slightly different physics from its parent universe; (3) he claimed that random variations in physics that would tend to produce universes that produce more black holes would cause such universes to produce more offspring (more universes); (4) he claims that as a result of this “increased reproduction rate” of some types of universes, we therefore would gradually see the evolution of physical laws and constants that tend to favor the appearance of life and also the production of black holes.

The speculations described above hinge upon the linchpin claim that a new universe can be produced from the collapse of a huge star to form a black hole. Some analysts let Smolin get away with making this claim, but there is no reason why that should be done. The idea that a new universe can be produced from the collapse of a black hole is a complete fantasy, with no basis in fact. We have no observations to support such a theory. Nor is there any physics or mathematics to support such a theory. There is no way to write an equation in which you put a new universe on the right side of an equal sign. 

The idea of universes being produced from black holes is a very silly one. A typical black hole arises from the collapse of a star with only only a few solar masses. A universe like ours has a mass-energy of at least 1,000,000,000,000,000,000,000 solar masses. Claiming a new universe can arise from a black hole is like claiming a planet can arise from a grain of sand. 

Smolin claimed that one advantage of his theory of cosmological natural selection is that it makes a falsifiable prediction. In a 2004 paper (page 38) he lists one such prediction:

“There is at least one example of a falsifiable theory satisfying these conditions, which is cosmological natural selection. Among the properties ...that make the theory falsifiable is that the upper mass limit of neutron stars is less than 1.6 solar masses. This and other predictions of CNS have yet to be falsified, but they could easily be by observations in progress.”

But by now this prediction has proven to be incorrect. In September 2019 a science news story reported on observations of one of the most massive neutron star ever found. We are told, “The researchers, members of the NANOGrav Physics Frontiers Center, discovered that a rapidly rotating millisecond pulsar, called J0740+6620, is the most massive neutron star ever measured, packing 2.17 times the mass of our Sun into a sphere only 30 kilometers across.” A 2021 story lists the mass of this neutron star as 2.14 solar masses. 

Last week in our science news we had the headline of "Black Widow Pulsar Sets Mass Record." A Sky and Telescope story dated July 28 tells us this: 

"The pulsar PSR J0952-0607, which is some 20,000 light-years away in the constellation Sextans, already holds the title of second-fastest-known rotator, spinning around its axis 707 times per second. Now, it has also shattered the record for most massive neutron star known, weighing in at 2.35 solar masses."

 A CNN story last week confirms; it states, "The PSR J0952-0607 star is 2.35 times the mass of the sun." Below we see an artist's depiction of a neutron star. 

Credit: NASA Goddard Space Flight Center

So Smolin told us that the cosmological natural selection theory would be falsified if any neutron stars were found to be more massive than 1.6 solar masses, and by now it has been found that one neutron star has 2.14 solar masses and another has 2.35 solar masses. Given last week's announcement that the neutron star PSR J0952-0607 has 2.35 times the mass of the sun, we can consider the cosmological natural selection theory to be even more falsified than it previously was. 

But alas, in the world of science it is sadly true that theories keep living on in the speech of scientists long after they have been falsified, kind of like the zombies of bad movies that keep walking about even after they have been killed. Some of the main theories claimed to be "scientific fact" seem to be theories of this type. 

In the past week we had two other science new stories throwing cold water in the face of theorists:

(1) A news story entitled "No trace of dark matter halos" quotes a scientist saying that *the number of publications showing incompatibilities between observations and the dark matter paradigm just keeps increasing every year."

(2) Another article reports that some cosmological model trying to speculate about an eternal cyclical universe falls flat, and actually requires a beginning of the universe. 

Smolin Seems to Have Lost His Multiverse Enthusiasm

Physicist Lee Smolin has a new book entitled Einstein's Unfinished Revolution: The Search for What Lies Beyond the Quantum. In the book, Smolin sells himself as a realist. Contrary to many scientists, he claims that quantum mechanics does not require any radical revision of old-fashioned ideas about the relation between the physical world and the observer. In the preface, he states, “Commonsense realism, according to which science can aspire to give a complete picture of the natural world as it is, or would be in our absence, is not actually threatened by anything we know about quantum mechanics.”

His case for this claim is not terribly convincing. He discusses some theories that supposedly allow us to keep quantum mechanics and maintain such a “commonsense realism.” But he's frank in discussing problems, shortcomings and drawbacks of such theories, so frank that we're not left thinking that any one of these theories is very likely to be true.

In the preface Smolin refers rather scornfully to the idea of the multiverse, that our universe is only one of many universes. He states the following:

“A vocal minority of cosmologists proclaims that the universe we see around us is only a bubble in a vast ocean called the multiverse that contains an infinity of other bubbles....The fact that all, or almost all, of the other bubbles are forever out of range of our observations, means the multiverse hypothesis can never be tested or falsified. This puts this fantasy outside the bounds of science.”

That sounds very down-to-earth, and fits in with Smolin's positioning of himself in the book as a realist. But what is strange is that Smolin himself was for many years a champion of a multiverse theory that he had created. He called the theory “cosmological natural selection,” and advanced it in a book called The Life of the Cosmos. In his book Time Reborn, Smolin describes the theory as follows:

“The basic hypothesis of cosmological natural selection is that universes reproduce by the creation of new universes inside black holes. Our universe is thus a descendant of another universe, born in one of its black holes, and every black hole in our universe is the seed of a new universe. This is a scenario within which we can apply the principles of natural selection.”

I discuss this theory and some reasons for doubting it in this post.  

Smolin claimed that one advantage of his theory of cosmological natural selection is that it makes a falsifiable prediction. In a 2004 paper (page 38) he lists one such prediction:

“There is at least one example of a falsifiable theory satisfying these conditions, which is cosmological natural selection. Among the properties W that make the theory falsifiable is that the upper mass limit of neutron stars is less than 1.6 solar masses. This and other predictions of CNS have yet to be falsified, but they could easily be by observations in progress.”

But by now this prediction has proven to be incorrect. In September 2019 a science news story reported on observations of the most massive neutron star ever found. We are told, “The researchers, members of the NANOGrav Physics Frontiers Center, discovered that a rapidly rotating millisecond pulsar, called J0740+6620, is the most massive neutron star ever measured, packing 2.17 times the mass of our Sun into a sphere only 30 kilometers across.”

So Smolin told us that the cosmological natural selection theory would be falsified if neutron stars were found to be more massive than 1.6 solar masses, and by now it has been found that a neutron star has 2.17 solar masses. I guess we can consider the cosmological natural selection theory to be falsified.

Art depicting a neutron star (Credit: NASA'S Goddard Space Flight Center)

Judging from his latest book, Smolin may have kind of deep-sixed or lost interest in his main theoretical offspring, the theory of cosmological natural selection. Such a theory was a multiverse theory, but now in the passage I quoted Smolin dismisses multiverse theories as “fantasy.” The index of Smolin's new book makes no mention of the theory of cosmological natural selection, and I can't recall him mentioning it in the book. The book jacket lists other books Smolin has written (including his excellent book The Trouble with Physics), but makes no mention of his opus The Life of the Cosmos selling us the theory of cosmological natural selection.

Smolin's latest book book is very thoughtful, readable and well-written, explaining some abstruse topics (such as pilot-wave theory) more clearly than I have ever read them expounded. Smolin denounces the Everett “many-worlds” theory, stating on page 172, “The Everett hypothesis, if successful, would explain vastly too much, and also much too little.”

The Everett many-worlds theory is the groundless nonsensical notion that reality is constantly splitting up into different copies of itself, so that there are an infinity of parallel universes. On page 178 of the book, Smolin perceives the ruinous moral implications of such a theory. Using the term “somewhere else in the wave function” to refer to imagined parallel universes, he notes, “If every eventuality we worked to eliminate, whether starvation, disease or tyranny, was actual somewhere else in the wave function, then our efforts would not result in an overall improvement.” Smolin states the following:

“If no matter what choices I make in life, there will be a version of me that will take the opposite choice, then why does it matter what I choose? There will be a branch in the multiverse for every option I might have chosen. There are branches in which I become as evil as Stalin and Hitler and there are branches where I am loved as a successor to Gandhi. I might as well be selfish and make the choices that benefit me....This seems to me to be an ethical problem because simply believing in the existence of all those copies lessens my sense of moral responsibility.”

I had made a very similar comment prior to Smolin's 2019 book. In a post published on April 8, 2018 I called the Everett many-worlds theory an evil doctrine because of its morality-killing tendencies. I stated the following:

“Why is the Everett 'many worlds' theory an evil doctrine? It is because if a person seriously believed such a doctrine, such a belief would tend to undermine any moral inclinations he had. I will give a concrete example. Imagine you are driving in your car at 2:00 AM on a bitterly cold snowy night, and you see a scantily clad very young child walking alone far from anyone. If you don't believe in the Everett 'many worlds' theory, you may stop your car and call the police to alert them of this situation, or do something like give your warm coat to the child to keep her warm. But if you believe in the Everett “many worlds” theory, you may reason like this: regardless of what I do, there will be an infinite number of parallel universes in which the child freezes to death, and an infinite number of other parallel universes in which the child does not freeze to death; so there's really no point in doing anything. So you may then drive on without stopping or doing anything, convinced that the multiverse would still be the same no matter how you acted.”

Being infinitely extravagant and completely groundless, as well as morally disastrous, the Everett “many worlds” theory of an infinity of parallel universes (and infinite copies of yourself) is best described as “evil nonsense.” I am pleased to find that I am not the only who recognizes how morally ruinous such speculation is.

The Implications If Black Holes Don't Exist

Black holes have been a leading player on the astrophysical scene since at least the 1970's. We know that on the surface of stars like the sun, there is a delicate balance between the inward force of gravity and the outer force caused by thermonuclear fusion, the process by which the sun produces energy. When stars like the sun run out of fuel, this balance is broken, and the force of gravity becomes dominant. This causes the star to collapse into a smaller, denser type of star called a white dwarf. For other stars more massive than the sun, the gravitational collapse of a dying star may be more drastic, causing the core of the star to collapse to become an ultra-dense neutron star. But when even more massive stars collapse at the end of their lifetime, scientists believe the collapse just keeps on going uncontrollably until a black hole is formed.

A black hole (Credit: NASA/CXC/M.Weiss)

At the core of a black hole is believed to be an infinite density called a singularity. Black holes are believed to have a tremendous gravitational attraction, but no observable surface features in themselves (although we can see their nearby effects). A black hole is believed to be a very simple object that can be completely described by only a few numbers, one of which is its mass.

But yesterday physicist Laura Mersini-Houghton published a scientific paper (not yet peer-reviewed) claiming to show that black holes don't actually exist. According to her calculations, when the most massive type of star is undergoing gravitational collapse, it shrinks to a very small size, but then quantum mechanical effects start to dominate, preventing the star from collapsing to become an infinitely dense singularity.

I gather that by claiming that black holes don't really exist, the idea is not that black holes are a complete illusion, but that they are simply things that don't really have an infinitely dense singularity, as astrophysicists assumed. We know from astronomical observations that the cores of many galaxies have objects that are something like black holes, regardless of whether they have an infinitely dense singularity.

I am a bit skeptical about this “black holes don't exist” claim, partially because Mersini-Houghton is the same scientist who made some previous cosmological claims that I found to be unwarranted. But let's ignore that, and assume that Mersini-Houghton may be right about this matter. What are the implications if it turns out that black holes don't really exist?

I can think of two big implications. The first implication is that the nonexistence of black holes would completely destroy Lee Smolin's theory of cosmological natural selection. That is the theory that attempts to account for fine-tuning in our universe by imagining that our universe is the product of a “cosmic natural selection” process that supposedly occurs because black holes collapse to become new universes.

The theory of cosmological natural selection is truly a “flight of fancy” which is 99% wild speculation and 1% fact. We have no reason for believing that a black hole collapse would form another universe. As the physicist Leonard Susskind has pointed out, the theory of cosmological natural selection violates a central finding about black holes, which is that information cannot be transferred from a black hole. As Susskind put it in his “Final Letter” in the Smolin/Susskind debate (The Universe page 198):

No information about the parent can survive the infinitely violent singularity at the center of a black hole. If such a thing as a baby universe makes any sense at all, the baby will have no special resemblance to the mother. Given that, the idea of an evolutionary history that led by natural selection to our universe makes no sense.

As mentioned here, the theory of cosmological natural selection also has been stymied by observations that contradict its predictions. If it is true that black holes do not even exist, that would be the final nail in the coffin of the theory of cosmological natural selection (because black holes are a crucial pillar of the theory).

If no black holes exist, it could also have implications relating to the Big Bang. Contrary to what a few people have suggested, if black holes are ruled out, it would not endanger the Big Bang theory. The Big Bang theory was introduced long before the idea of black holes came into prominence, and the Big Bang theory has no dependence on the existence of black holes formed from stars. The central reason for believing in the Big Bang is the fact that the universe is expanding; "run the film backward" on such an expansion, and you are forced to begin with something like the Big Bang. 

The only relation to black holes and the Big Bang theory is that the event described by the Big Bang theory is rather like a black hole collapse in reverse (although vastly larger). Scientists say that the Big Bang was an expansion of the universe from an infinitely dense singularity. So it was a little like the collapse of a star into an infinitely dense singularity (a black hole), except the opposite, and involving incomparably more matter.

This similarity doesn't really do much of anything to make the Big Bang seem less astonishing. But at least it gives scientists some thread of similarity they can use to compare the Big Bang to a natural event. It's a very, very thin thread of similarity, because saying that the Big Bang is like a black hole collapse in reverse is kind of like saying, “No big deal,” after seeing a three-egg omelet jump back into three egg shells, on the basis that it's just the breaking of the eggs in reverse.

But what if there are no black holes? Then even this slim thread of similarity to a natural event is eliminated, and we are left with a Big Bang that would be absolutely unlike any event in nature, going forward or going in reverse. That would make the Big Bang seem all the more miraculous. 

Black Widow Pulsar Gives Fatal Bite to Theory of Cosmological Natural Selection

Faced with the fine-tuning problem of why the universe seems to be so well calibrated to allow the existence of intelligent life, some thinkers have advanced the idea of a multiverse, the idea that there is a vast ensemble of universes. The thinking is that if there are an infinite or nearly infinite number of universes, then we might expect one of them to luckily have just the right conditions allowing for observers. The drawbacks of this approach are many: the nearly infinite baggage of assuming all of those universes, almost all uninhabited; the violation of the principle of Occam's Razor asserting that “entities should not be multiplied beyond necessity” when trying to explain something; the violation of the principle of mediocrity asserting that a random sample from a larger population should be assumed to be representative of the population; the fact that we have never had a verified case of anything being successfully explained by a multiverse; the fact that while the probability of some universe being habitable by chance may be improved by assuming other universes, the probability of any particular universe (including our universe) being habitable by chance is not at all improved by such an assumption, not even by even 1 percent.

Perhaps sensing the weakness of a simple multiverse theory, some theorists have advanced a more complicated theory – a theory they call cosmological natural selection. The idea seems to have first been advanced by the physicist Lee Smolin (author of the excellent book The Trouble With Physics). In his book Time Reborn, Smolin describes the theory as follows:

The basic hypothesis of cosmological natural selection is that universes reproduce by the creation of new universes inside black holes. Our universe is thus a descendant of another universe, born in one of its black holes, and every black hole in our universe is the seed of a new universe. This is a scenario within which we can apply the principles of natural selection.

Smolin claims to have a theory of how the physics of the universe could evolve through natural selection. But how on earth can we get anything like natural selection out of the idea of new universes being created by the formation of black holes? Smolin gives the following strained reasoning: (1) he claims that the physics that favors a habitable universe are similar to the physics that favor the production of black holes; (2) he claims that a new universe produced by a black hole might have slightly different physics from its parent universe; (3) he claims that random variations in physics that would tend to produce universes that produce more black holes would cause such universes to produce more offspring (more universes); (4) he claims that as a result of this “increased reproduction rate” of some types of universes, we therefore would gradually see the evolution of physical laws and constants that tend to favor the appearance of life and also the production of black holes.

Artist's depiction of black hole (Credit: NASA Goddard Space Flight Center)

But there are many holes in this theory based on black holes.

First, let's look at the linchpin claim that a new universe can be produced from the collapse of a huge star to form a black hole. Some analysts let Smolin get away with making this claim, but there is no reason why that should be done. The idea that a new universe can be produced from the collapse of a black hole is a complete fantasy, with no basis in fact. We have no observations to support such a theory.

But let's try to open the door to such an idea. What would it be like if the matter in a collapsing star formed a black hole, and that extreme density of matter caused the surrounding space to be pinched off into its own little bubble? What would we then have? Such a little bubble should not be called a new universe, as that gives a completely misleading idea of some vast area with enough matter to form many galaxies. The bubble would be properly referred to as a spacetime bubble, or a micro-universe.

If such a spacetime bubble were to be formed, what would happen to the matter that was trapped in the black hole? It would be separated from our universe permanently, sealed off in its own little realm. We would no longer observe the gravitational effects of that matter in our universe. We would observe that black holes do not exert gravitational effects once they form. But that is not at all what we observe in regard to black holes. Black holes continue to exert very strong gravitational effects (such as sucking up all nearby gas), just as if their matter continued to exist in our universe. In short, our observations are in conflict with the idea that when a massive star collapses to become a black hole, that matter exits our universe to form another universe. Our observations indicate that the matter lost in black holes is still here in our universe.

And what if the matter in a collapsing star were to cause a new universe when a black hole formed, and the matter moved over to that universe? You would then have a tiny little one-star-sized universe. Such a possibility is worthless in explaining our universe, which has the mass of at least 1,000,000,000,000,000,000 stars. 

Another problem with Smolin's theory is that it absolutely requires you to believe that our universe has been optimized to produce a maximum number of black holes -- a thesis that is rather implausible given the fact that the nearest black hole is no closer than 1500 light years away, and that only one in about 30,000,000 nearby stars is a black hole.  In fact, other scientists maintain that the universe is not at all optimized to produce black holes. 

Another huge problem with Smolin's idea is that it does not explain how any universe could have originally came to exist in the state in which black holes could exist in it (a state similar to a state in which life could exist in it), a state enormously improbable to occur by chance. Although you may associate the concept of black holes with ideas of chaos, randomness, or disorder, there are actually many requirements that any universe must meet in order for it to have stars that can form into black holes. Smolin lists 6 such requirements on page 36 of this paper, all of which are incredibly lucky long shots. Another requirement is that the proton charge very precisely match the electron charge to many decimal places, for unless you have that coincidence there will never exist the stars from which black holes form.

In our universe the proton charge and the electron charge match to at least eighteen decimal places, and there is every reason to think that this fine balance is necessary for stars to exist. Imagine if the proton charge and the electron charge differed by one part in a trillion. That would be like increasing the electromagnetic forces on a star by one part in a trillion. But the electromagnetic force (one of the four fundamental forces) is about a trillion trillion trillion times greater than the gravitational force (another of the four fundamental forces), which means that even if there were a very tiny difference in the proton charge and the electron charge (say, 1 part in a trillion), the resulting repulsive force would be many, many times greater than the force of gravity holding together stars, and stars could not hold together. Greenstein (a professor emeritus at Amherst) says that the proton charge and the electron charge have to be balanced to 18 decimal places for stars to exist.

So let's imagine a collection or series of universes with random properties. It would require an incredibly unlikely set of conditions for any particular one of these universes to have the conditions necessary to produce black holes – a long shot with odds of no greater than 1 in a billion billion. According to Smolin's theory, once such a universe existed it might begin making copies of itself, as black holes formed new universes. So if you started out with several billion billion universes, a few might produce black holes, and then gradually (according to Smolin's theory), the fraction of the universes that had black holes (and that were compatible with life) might keep getting higher and higher over the eons. Such a theory might comfort some people by making our universe seem not so untypical in a collection of universes. But it would do nothing to explain the original incredibly unlikely long shot.

To give an analogy, imagine you have a book-copying robot which is given a copy of a rare and wonderful book, such as a first edition of Dickens. Such a robot might then make 1000 copies of the book, and stack them on your bookshelf. Seeing all of those copies on your bookshelf, you might then tend to think that the original first edition was not so rare and wonderful, but this machine would not at all explain the origin of the first edition in the first place, something that would be very hard to plausibly explain by any theory of luck.

Smolin claims that one advantage of his theory is that it makes a falsifiable prediction, and in a 2004 paper (page 38) he lists one such prediction:

There is at least one example of a falsifiable theory satisfying these conditions, which
is cosmological natural selection. Among the properties W that make the theory
falsifiable is that the upper mass limit of neutron stars is less than
1.6 solar masses. This and other predictions of CNS have yet to be falsified, but

they could easily be by observations in progress.

But in this 2010 Science Daily piece reported the discovery of a neutron star: “The researchers expected the neutron star to have roughly one and a half times the mass of the Sun. Instead, their observations revealed it to be twice as massive as the Sun."

So according to Smolin's own guideline, the theory of cosmological natural selection has been falsified. He said it would be falsified if we discovered any neutron stars greater than 1.6 solar masses, and a neutron star with a mass of 2.0 solar masses has been discovered.

In fact, this paper estimates that a particular neutron star called the black widow pulsar has 2.4 solar masses. In his book Time Reborn, Smolin concedes, “If that finding holds up under more precise measurements, cosmological natural selection will be falsified.”

It would seem that the black widow pulsar has delivered a fatal bite to the theory of cosmological natural selection, somewhat like a black widow spider giving a fatal bite to a human.