Fine-tuning of the cosmological constant

Fine-tuning of the  cosmological constant

https://reasonandscience.catsboard.com/t1885-fine-tuning-of-the-cosmological-constant

Geoff Brumfiel Outrageous fortune 04 January 2006
In much the same way as Kepler worried about planetary orbits, cosmologists now puzzle over numbers such as the cosmological constant, which describes how quickly the Universe expands. The observed value is so much smaller than existing theories suggest, and yet so precisely constrained by observations, that theorists are left trying to figure out a deeper meaning for why the cosmological constant has the value it does. To explain the perfectly adjusted cosmological constant one would need at least 1060 universes
https://www.nature.com/articles/439010a

The Cosmological constant (which controls the expansion speed of the universe) refers to the balance of the attractive force of gravity with a hypothesized repulsive force of space observable only at very large size scales. It must be very close to zero, that is, these two forces must be nearly perfectly balanced. To get the right balance, the cosmological constant must be fine-tuned to something like 1 part in 10^120. If it were just slightly more positive, the universe would fly apart; slightly negative, and the universe would collapse. As with the cosmological constant, the ratios of the other constants must be fine-tuned relative to each other. Since the logically possible range of strengths of some forces is potentially infinite, to get a handle on the precision of fine-tuning, theorists often think in terms of the range of force strengths, with gravity the weakest, and the strong nuclear force the strongest. The strong nuclear force is 10^40 times stronger than gravity, that is, ten thousand, billion, billion, billion, billion times the strength of gravity. Think of that range as represented by a ruler stretching across the entire observable universe, about 15 billion light-years. If we increased the strength of gravity by just 1 part in 10^34 of the range of force strengths (the equivalent of moving less than one inch on the universe-long ruler), the universe couldn’t have life-sustaining planets.

Neil A. Manson The Fine-Tuning Argument  4/1 (2009)
The universe would not have been the sort of place in which life could emerge – not just the very form of life we observe here on Earth, but any conceivable form of life, if the mass of the proton, the mass of the neutron, the speed of light, or the Newtonian gravitational constant were different.  In many cases, the cosmic parameters were like the just-right settings on an old-style radio dial: if the knob were turned just a bit, the clear signal would turn to static. As a result, some physicists started describing the values of the parameters as ‘fine-tuned’ for life. To give just one of many possible examples of fine-tuning, the cosmological constant (symbolized by the Greek letter ‘Λ’) is a crucial term in Einstein’s equations for the General Theory of Relativity. When Λ is positive, it acts as a repulsive force, causing space to expand. When Λ is negative, it acts as an attractive force, causing space to contract. If Λ were not precisely what it is, either space would expand at such an enormous rate that all matter in the universe would fly apart, or the universe would collapse back in on itself immediately after the Big Bang. Either way, life could not possibly emerge anywhere in the universe. Some calculations put the odds that ½ took just the right value at well below one chance in a trillion trillion trillion trillion. Similar calculations have been made showing that the odds of the universe’s having carbon-producing stars (carbon is essential to life), or of not being millions of degrees hotter than it is, or of not being shot through with deadly radiation, are likewise astronomically small. Given this extremely improbable fine-tuning, say, proponents of FTA, we should think it much more likely that God exists than we did before we learned about fine-tuning. After all, if we believe in God, we will have an explanation of fine-tuning, whereas if we say the universe is fine-tuned by chance, we must believe something incredibly improbable happened.
http://home.olemiss.edu/~namanson/Fine%20tuning%20argument.pdf


Stephen C. Meyer: The return of the God hypothesis, page 185
The cosmological constant requires an even greater degree of fine-tuning. (Remember that the cosmological constant is a constant in Einstein’s field equations. It represents the energy density of space that contributes to the outward expansion of space in opposition to gravitational attraction.) The most conservative estimate for that fine-tuning is 1 part in 10^53 , but the number 1 part in 10^120 is more frequently cited. Physicists now commonly agree that the degree of fine-tuning for the cosmological constant is no less than 1 part in 10^90 .

To get a sense of what this number means, imagine searching the vastness of the visible universe for one specially marked subatomic particle. Then consider that the visible universe contains about 200 billion galaxies each with about 100 billion stars along with a panoply of asteroids, planets, moons, comets, and interstellar dust associated with each of those stars. Now assume that you have the special power to move instantaneously anywhere in the universe to select—blindfolded and at random—any subatomic particle you wish. The probability of your finding a specially marked subatomic particle—1 chance in 10^80—is still 10 billion times better than the probability—1 part in 10^90—that the universe would have happened upon a life-permitting strength for the cosmological constant.

Sean Carroll: The Cosmological Constant 7 February 2001 8
We happen to live in that brief era, cosmologically speaking, when both matter and vacuum are of comparable magnitude.  This scenario staggers under the burden of its unnaturalness. A major challenge to cosmologists and physicists in the years to come will be to understand whether these apparently distasteful aspects of our universe are simply surprising coincidences, or actually reflect a beautiful underlying structure
we do not as yet comprehend.

My comment: Or the data may lead to the conclusion that God hat to be involved in creating the universe, and set the constants just right.

The most fine-tuned of these parameters seems to be the cosmological constant, a concept that Albert Einstein proposed to provide an outward-pushing pressure that he thought was needed to prevent gravity from causing the universe's matter from collapsing onto itself. 7

On the largest scales, there’s also a cosmic tug-of-war between the attractive force of gravity and the repulsive dark or vacuum energy. Often called the cosmological constant, which is theorized to be the result of a nonzero vacuum energy detectable at cosmological scales, it’s one of the few cosmological parameters that determine the dynamics of the universe as a whole. By observing Type Ia supernovae, astronomers have determined that today it contributes about as much to the dynamics of the universe as the gravitational attractive force from visible and dark matter combined. This coincidence remains unexplained, but some cosmologists suspect it’s amenable to “anthropic explanation.” 6

There’s only one “special” time in the history of the universe when the vacuum and matter-energy densities are the same, and we’re living very near it. If the vacuum energy had become prominent a few billion years earlier than it did in our universe, there would have been no galaxies. If it had overtaken gravity a little earlier still, there would have been no individual stars. A few billion years might seem like a lot of room to manoeuvre, but there’s an even more striking level of fine-tuning here. The second “cosmological constant problem” is that the observed value of the vacuum energy is between 10^53 and 10^123 times smaller than that expected from theory. The vacuum energy density is, basically, the energy density of spacetime in the absence of fields resulting from matter.28 Until the Type Ia supernovae results demonstrated a few years ago that the cosmological constant is something other than zero, most cosmologists hoped that some undiscovered law of physics required it to be exactly zero. They already knew that its observational upper limit was much smaller than the “natural” values expected from various particle fields and other theoretical fields. These particle fields require an extraordinary degree of fine-tuning— at least to one part in 10^53—to get such a small, positive, nonzero value for the vacuum energy. At the same time, its value must be large enough in the early universe to cause the newborn universe to expand exponentially, as inflation theory postulates. How the present value of the vacuum energy relates to the early expansion is yet another issue of debate.

Max Tegmark:
“How far could you rotate the dark-energy knob before the “Oops!” moment? If rotating it…by a full turn would vary the density across the full range, then the actual knob setting for our Universe is about 10^123 of a turn away from the halfway point. That means that if you want to tune the knob to allow galaxies to form, you have to get the angle by which you rotate it right to 123 decimal places!

That means that the probability that our universe contains galaxies is akin to exactly 1 possibility in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 . Unlikely doesn’t even begin to describe these odds. There are “only” 10^81 atoms in the observable universe, after all.
http://www.secretsinplainsight.com/2015/09/19/cosmic-lottery/

The cosmological constant
The smallness of the cosmological constant is widely regarded as the single the greatest problem confronting current physics and cosmology The cosmological constant is a term in Einstein’s equation that, when positive, acts as a repulsive force, causing space to expand and, when negative, acts as an attractive force, causing space to contract. Apart from some sort of extraordinarily precise fine-tuning or new physical principle, today’s theories of fundamental physics and cosmology lead one to expect that the vacuum that is, the state of space-time free of ordinary matter fields—has an extraordinarily large energy density. This energy density, in turn, acts as an effective cosmological constant, thus leading one to expect an extraordinarily large effective cosmological constant, one so large that it would, if positive, cause space to expand at such an enormous rate that almost every object in the Universe would fly apart, and would, if negative, cause the Universe to collapse almost instantaneously back in on itself. This would clearly, make the evolution of intelligent life impossible. What makes it so difficult to avoid postulating some sort of highly precise fine-tuning of the cosmological constant is that almost every type of field in current physics—the electromagnetic field, the Higgs fields associated with the weak force, the inflaton field hypothesized by inflationary cosmology, the dilaton field hypothesized by superstring theory, and the fields associated with elementary particles such as electrons—contributes to the vacuum energy. Although no one knows how to calculate the energy density of the vacuum, when physicists make estimates of the contribution to the vacuum energy from these fields, they get values of the energy density anywhere from 10^53 to 10^120 higher than its maximum life-permitting value, max.6 (Here, max is expressed in terms of the energy density of empty space.)
GOD AND DESIGN The teleological argument and modern science , page 180

Max Tegmark:
“How far could you rotate the dark-energy knob before the “Oops!” moment? The current setting of the knob, corresponding to the dark-energy density we’ve actually measured, is about 10−27 kilograms per cubic meter, which is almost ridiculously close to zero compared to the available range: the natural maximum value for the dial is a dark-energy density around 1097 kilograms per cubic meter, which is when the quantum fluctuations fill space with tiny black holes, and the minimum value is the same with a minus sign in front. If rotating the dark-energy knob…by a full turn would vary the density across the full range, then the actual knob setting for our Universe is about 10^123 of a turn away from the halfway point. That means that if you want to tune the knob to allow galaxies to form, you have to get the angle by which you rotate it right to 123 decimal places!

That means that the probability that our universe contains galaxies is akin to exactly 1 possibility in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,
000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 . Unlikely doesn’t even begin to describe these odds. There are “only” 10^81 atoms in the observable universe, after all. 4

The Balance of the Bang: In order for life to be possible in the universe, the explosive power of the Big Bang needed to be extremely closely matched to the amount of mass and balanced with the force of gravity, so that the expansion-speed is very precise. 1 This very exact expansion-speed of the universe, is called the "Cosmological Constant." If the force of the bang was slightly too weak, the expanding matter would have collapsed back in on itself before any planets suitable for life (or stars) had a chance to form, ---but if the bang was slightly too strong, the resultant matter would have been only hydrogen gas that was so diffuse and expanding so fast, that no stars or planets could have formed at all.

Science writer Gregg Easterbrook explains the required explosive power-balance of the Big Bang, saying that, "Researchers have calculated that, if the ratio of matter and energy to the volume of space ...had not been within about one-quadrillionth of one percent of ideal at the moment of the Big Bang, the incipient universe would have collapsed back on itself or suffered runaway relativity effects" (My emphasis.) (ref. G.Easterbrook, "Science Sees the Light", The New Republic, Oct.12, 1998, p.26).
In terms of the expansion rate of the universe as a result of the Big Bang: "What's even more amazing is how delicately balanced that expansion rate must be for life to exist. It cannot differ by more than one part in 10^55 from the actual rate." (My emphasis.) (Ref: H.Ross, 1995, as cited above, p.116). (Note: 10^55 is the number 1 with 55 zeros after it ---and 10^55 is about the number of atoms that make up planet earth).
THE PROBABILITY: The chances we can conservatively assign to this: It was about one chance out of 1021 that the force of the Big Bang could have randomly been properly balanced with the mass & gravity of the universe, in order for stars and planets to form, so that life could exist here in our cosmos.

Leonard Susskind  The Cosmic Landscape:
"To make the first 119 decimal places of the vacuum energy zero is most certainly no accident." (The vacuum energy relates to the cosmological constant.) 2
“Logically, it is possible that the laws of physics conspire to create an almost but not quite perfect cancellation [of the energy involved in the quantum fluctuations]. But then it would be an extraordinary coincidence that that level of cancellation—119 powers of ten, after all—just happened by chance to be what is needed to bring about a universe fit for life. How much chance can we buy in scientific explanation? One measure of what is involved can be given in terms of coin flipping: odds of 10^120 to one is like getting heads no fewer than four hundred times in a row. if the existence of life in the universe is completely independent of the big fix mechanism—if it’s just a coincidence—then those are the odds against our being here. That level of flukiness seems too much to swallow.”

The Case of Negative λ 
So far I have told you about the repulsive effects that accompany positive vacuum energy. But suppose that the contribution of fermions outweighed that of bosons: then the net vacuum energy would be a negative number. Is this possible? If so, how does it affect Weinberg’s arguments? The answer to the first question is yes, it can happen very easily. All you need is a few more fermion-type particles than bosons and the cosmological constant can be made negative. The second question has an equally simple answer—changing the sign of λ switches the repulsive effects of a cosmological constant to a universal attraction: not the usual gravitational attractive force but a force that increases with distance. To argue convincingly that a large cosmological constant would automatically render the universe uninhabitable, we need to show that life could not form if the cosmological constant were large and negative. What would the universe be like if the laws of nature were unaltered except for a negative cosmological constant? The answer is even easier than the case of positive λ. The additional attractive force would eventually overwhelm the outward motion of the Hubble expansion: the universe would reverse its motion and start to collapse like a punctured balloon. Galaxies, stars, planets, and all life would be crushed in an ultimate “big crunch.” If the negative cosmological constant were too large, the crunch would not allow the billions of years necessary for life like ours to evolve. Thus, there is an anthropic bound on negative λ to match Weinberg’s positive bound. In fact, the numbers are fairly similar. If the cosmological constant is negative, it must also not be much bigger than 10^120 Units if life is to have any possibility of evolving. Nothing we have said precludes there being pocket universes far from our own with either a large positive or large negative cosmological constant. But they are not places where life is possible. In the ones with large positive λ, everything flies apart so quickly that there is no chance for matter to assemble itself into structures like galaxies, stars, planets, atoms, or even nuclei. In the pockets with large negative λ, the expanding universe quickly turns around and crushes any hope of life.
https://3lib.net/book/2472017/1d5be1

Cover America with coins in a column reaching to the moon (380,000 km or 236,000 miles away), then do the same for a billion other continents of the same size.  Paint one coin red and put it somewhere in one billion of the piles.  Blindfold a friend and ask her to pick the coin.  The odds of her picking it are 1 in 10^37

Stephen Hawking writes in A Brief History of Time, p. 125:
"The remarkable fact is that the values of these numbers (i.e. the constants of physics) seem to have been very finely adjusted to make possible the development of life" (p. 125)

Extreme Fine Tuning - the Cosmological Constant 3
The recent Nature study popularized in the press regarding the nature of the universe has confirmed some of the original studies involving supernovae type 1.¹ The supernovae results suggested that there was a "springiness" to space, called the "cosmological constant," that causes the universe to expand at a faster rate the more it has expanded. Often described as an "anti-gravity" force, it doesn't really oppose matter, but only affects matter as it is associated with the fabric of space.

The balloon-borne microwave telescope (called "Boomerang") examined the cosmic background radiation left over from the Big Bang.² The angular power spectrum showed a peak value at exactly the value predicted by the inflationary hot Big Bang model dominated by cold dark matter. This model predicts a smaller second peak, which seems to be there, but cannot be fully resolved with the initial measurements. The presence of the second peak would all but seal the reliability of the Big Bang model as the mechanism by which the universe came into existence.

How does this study impact the Christian faith? The Bible says that the universe was created in finite time from that which is not visible.³ In addition, the Bible describes an expanding universe model. The Bible describes the Creator being personally involved in the design of the universe, so that we would expect to see this kind of design in His creation.⁴

How does this discovery impact atheists? Those who favor naturalism had long sought to find the simplest explanation for the universe, hoping to avoid any evidence for design. A Big Bang model in which there was just enough matter to equal the critical density to account for a flat universe would have provided that. However, for many years, it has been evident that there is less than half of the amount of matter in the universe to account for a flat universe. A cosmological constant would provide an energy density to make up for the missing matter density but would require an extreme amount of fine tuning. The supernovae studies demonstrated that there was an energy density to the universe (but did not define the size of this energy density), and the recent Boomerang study demonstrated that this energy density is exactly what one would expect to get a flat universe. How finely tuned must this energy density be to get a flat universe? One part in 10¹²⁰,⁵ which is:
1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
What do atheist think about this level of design? Here is a quote from a recent article:

"This type of universe, however, seems to require a degree of fine tuning of the initial conditions that is in apparent conflict with 'common wisdom'."¹

Atheists see a conflict because this level of design is something that one would not expect by chance from a universe that began through a purely naturalistic mechanism. "Common wisdom" is common only to those who must exclude a supernatural explanation for the creation of the universe. In fact, a purely naturalistic cause for the universe is extremely unlikely and, therefore, illogical. The Bible says that the fear of the Lord is the beginning of wisdom,⁶ and that He created the universe.⁷ When a model doesn't work, scientists must be willing to give up their model for a model that fits the facts better. In this case, the supernatural design model fits the data much better than naturalistic random chance model.

Guillermo Gonzalez, Jay W. Richards: The Privileged Planet: How Our Place in the Cosmos Is Designed for Discovery 2004 page 205
on the largest scales, there’s also a cosmic tug-of-war between the attractive force of gravity and the repulsive dark or vacuum energy. Often called the cosmological constant, which is theorized to be the result of nonzero vacuum energy detectable at cosmological scales, it’s one of the few cosmological parameters that determine the dynamics of the universe as a whole. By observing Type Ia supernovae, astronomers have determined that today it contributes about as much to the dynamics of the universe as the gravitational attractive force from visible and dark matter combined. This coincidence remains unexplained, but some cosmologists suspect it’s amenable to “anthropic explanation.”27 There’s only one “special” time in the history of the universe when the vacuum and matter-energy densities are the same, and we’re living very near it. If the vacuum energy had become prominent a few billion years earlier than it did in our universe, there would have been no galaxies. If it had overtaken gravity a little earlier still, there would have been no individual stars. A few billion years might seem like a lot of room to maneuver, but there’s an even more striking level of fine-tuning here. The second “cosmological constant problem” is that the observed value of the vacuum energy is between 1053 and 10123 times smaller than that expected from theory. The vacuum energy density is, basically, the energy density of space-time in the absence of fields resulting from matter.28 Until the Type Ia supernovae results demonstrated a few years ago that the cosmological constant is something other than zero, most cosmologists hoped that some undiscovered law of physics required it to be exactly zero. They already knew that its observational upper limit was much smaller than the “natural” values expected from various particle fields and other theoretical fields. These particle fields require an extraordinary degree of fine-tuning— at least to one part in 1053—to get such a small, positive, nonzero value for the vacuum energy. At the same time, its value must be large enough in the early universe to cause the newborn universe to expand exponentially, as inflation theory postulates. How the present value of the vacuum energy relates to the early expansion is yet another issue of debate.
https://3lib.net/book/5102561/45e43d



1. http://worldview3.50webs.com/mathprfcosmos.html
2. http://www.uncommondescent.com/intelligent-design/coin-flips-do-matter/
3. http://web.archive.org/web/20090730174024/http://geocities.com/CapeCanaveral/Lab/6562/apologetics/cosmoconstant.html
4. http://www.secretsinplainsight.com/2015/09/19/cosmic-lottery/
5. GOD AND DESIGN The teleological argument and modern science , page 180
6. Guillermo Gonzalez and Jay W. Richards THE PRIVILEGED PLANET HOW OUR PLACE IN THE COSMOS IS DESIGNED FOR DISCOVERY page 205
7. https://www.insidescience.org/news/more-finely-tuned-universe
8. https://sci-hub.ren/10.12942/lrr-2001-1

CALUM MILLER Defence of the fine-tuning argument JULY 25, 2017

The cosmological constant
As Collins puts it, “the smallness of the cosmological constant is widely regarded as the single greatest problem confronting current physics and cosmology.” The cosmological constant, represented by Λ, was hypothesised by Albert Einstein as part of his modified field equation. The idea is that Λ is a constant energy density of space which acts as a repulsive force – the more positive Λ is, the more gravity would be counteracted and thus the universe would expand. If Λ is too negative, the universe would have collapsed before star/galaxy formation while, if Λ is too positive, the universe would have expanded at a rate that similarly precluded star/galaxy formation. The difficulty encountered is that the vacuum energy density is supposed to act in an equivalent way to the cosmological constant, and yet the majority of posited fields (e.g. the inflaton field, the dilaton field, Higgs fields) in physics contribute (negatively or positively) to this vacuum energy density orders of magnitude higher than the life-permitting region would allow. Indeed, estimates of the contribution from these fields have given values ranging from 1053 to 10120 times the maximum life-permitting value of the vacuum energy density, ρmax.

As an example, consider the inflaton field, held to be primarily responsible for the rapid expansion in the first 10-35 to 10-37 seconds of the universe. Since the initial energy density of the inflaton field was between 1053ρmax and 10123ρmax, there is an enormous non-arbitrary, natural range of possible values for the inflaton field and for Λeff.[3] And so the fact that Λeff < Λmax represents some quite substantial fine tuning – clearly, at least, Wr/WR is very small in this case.

Similarly, the initial energy density of the Higgs field was extremely high, also around 1053ρmax. According to the Weinberg-Salem-Glashow theory, the electromagnetic and weak forces in nature merge to become an electroweak force at extremely high temperatures, as was the case shortly after the Big Bang. Weinberg and Salem introduced the “Higgs mechanism” to modern particle physics, whereby symmetry breaking of the electroweak force causes changes in the Higgs field, so that the vacuum density of the Higgs field dropped from 1053ρmax to an extremely small value, such that Λeff < Λmax.

The final major contribution to Λvac is from the zero-point energies of the fields associated with forces and elementary particles (e.g. the electromagnetic force). If space is a continuum, calculations from quantum field theory give this contribution as infinite. However, quantum field theory is thought to be limited in domain, such that it is only appropriately applied up to certain energies. However, unless this “cutoff energy” is extremely low, then there is considerable fine tuning necessary. Most physicists consider a low cutoff energy to be unlikely, and the cutoff energy is more typically taken to be the Planck energy. But if this is the case, then we would expect the energy contribution from these fields to be around 10120ρmax. Again, this represents the need for considerable fine tuning of Λeff.

One proposed solution to this is to suggest that the cosmological constant must be 0 – this would presumably be less than Λmax, and gives a ‘natural’ sort of value for the effective cosmological constant, since we can far more plausibly offer some reasons for why a particular constant has a value of 0 than for why it would have a very small, arbitrary value (given that the expected value is so large). Indeed, physicist Victor Stenger writes,

…recent theoretical work has offered a plausible non-divine solution to the cosmological constant problem. Theoretical physicists have proposed models in which the dark energy is not identified with the energy of curved space-time but rather with a dynamical, material energy field called quintessence. In these models, the cosmological constant is exactly 0, as suggested by a symmetry principle called supersymmetry. Since 0 multiplied by 10120 is still 0, we have no cosmological constant problem in this case. The energy density of quintessence is not constant but evolves along with the other matter/energy fields of the universe. Unlike the cosmological constant, quintessence energy density need not be fine-tuned.

As Stenger seems to recognise, the immediate difficulty with this is that the effective cosmological constant is not zero. We do not inhabit a static universe – our universe is expanding at an increasing rate, and so the cosmological constant must be small and positive. But this lacks the explanatory elegance of a zero cosmological constant, and so the problem reappears – why is it that the cosmological constant is so small compared to its range of possible values? Moreover, such an explanation would have to account for the extremely large cosmological constant in the early universe – if there is some kind of natural reason for why the cosmological constant has to be 0, it becomes very difficult to explain how it could have such an enormous value just after the Big Bang. And so, as Collins puts it, “if there is a physical principle that accounts for the smallness of the cosmological constant, it must be (1) attuned to the contributions of every particle to the vacuum energy, (2) only operative in the later stages of the evolution of the cosmos (assuming inflationary cosmology is correct), and (3) something that drives the cosmological constant extraordinarily close to zero, but not exactly zero, which would itself seem to require fine-tuning. Given these constraints on such a principle, it seems that, if such a principle exists, it would have to be “well-design” (or “fine-tuned”) to yield a life-permitting cosmos. Thus, such a mechanism would most likely simply reintroduce the issue of design at a different level.”

Stenger’s proposal, then, involves suggesting that Λvac + Λbare = 0 by some natural symmetry, and thus that 0 < Λeff = Λq < Λmax. It is questionable whether this solves the problem at all – plausibly, it makes it worse. Quintessence alone is not clearly less problematic than the original problem, both on account of its remarkable ad hoc-ness and its own need for fine tuning. As Lawrence Krauss notes, “As much as I like the word, none of the theoretical ideas for this quintessence seems compelling. Each is ad hoc. The enormity of the cosmological constant problem remains.” Or, see Kolda and Lyth’s conclusion that “quintessence seems to require extreme fine tuning of the potential V(φ)” – their position that ordinary inflationary theory does not require fine tuning demonstrates that they are hardly fine-tuning sympathisers. And so it is not at all clear that Stenger’s suggestion that quintessence need not be fine tuned is a sound one. Quintessence, then, has the same problems as the cosmological constant, as well as generating the new problem of a zero cosmological constant.

There is much more to be said on the problem of the cosmological constant, but that is outside the scope of this article. For now, it seems reasonable to say, contra Stenger, that Wr/WR << 1 and therefore that F obtains for the value of the cosmological constant.
https://calumsblog.com/2017/07/25/full-defence-of-the-fine-tuning-argument-part-4/


The task of a multiverse generator
The smallness of the cosmological constant is widely regarded as the single the greatest problem confronting current physics and cosmology. The cosmological constant acts as a repulsive force, causing space to expand and, when negative, acts as an attractive force, causing space to contract. To get our universe, this constant must be right amongst 10^123 possibilities. That means that the statistical likeliness that our universe contains galaxies is akin to exactly 1 possibility in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000, 000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 . Unlikely doesn’t even begin to describe these odds. There are “only” 10^81 atoms in the observable universe, after all. Thirty billion years contains only 10^18 seconds. By totaling those, we find that the maximum elementary particle events in 30 billion years could only be 10^143.
Now let's suppose there was a multiverse generator. He would have had to make up to 10^123 attempts to get one universe with the right expansion rate. He would have made 10^18 attempts after 30 billion years.

Once he had that right, to get a universe with atoms, he would have to make the following number of trials:
the right Ratio of Electrons: Protons 1:10^37
Ratio of Electromagnetic Force: Gravity 1:10^40
If a multiverse generator existed, he must have been VERY busy in the last trillion trillion trillion years to get out only our unverse......
does that make sense?

The cosmological constant is a number that determines the energy density of the vacuum. It acts like a kind of pressure that, depending on its value, acts against gravity to push the universe apart or acts with gravity to pull the universe together towards a final Big Crunch.

Until recently, cosmologists had assumed that the constant was zero, a neat solution. But the recent evidence that the universe is not just expanding but accelerating away from us, suggests that the constant is positive.

But although positive, the cosmological constant is tiny, some 122 orders of magnitude smaller than Planck’s constant, which itself is a small number.

So Page and others have examined the effects of changing this constant. It’s straightforward to show that if the the constant were any larger, matter would not form into galaxies and stars meaning that life could not form, at least not in the form we know it,.

So what value of the cosmological constant best encourages galaxy and star formation, and therefore the evolution of life? Page says that a slightly negative value of the constant would maximise this process. And since life is some small fraction of the amount of matter in galaxies, then this is the value that an omnipotent being would choose.

In fact, he says that any positive value of the constant would tend to decrease the fraction of matter that forms into galaxies, reducing the amount available for life.

https://www.technologyreview.com/s/422444/evidence-emerges-that-laws-of-physics-are-not-fine-tuned-for-life/

The cosmological constant problem Steven Weinberg (1989), p. 1
"Theoretical expectations for the cosmological constant exceed observational limits by some 120 orders of magnitude."
https://repositories.lib.utexas.edu/bitstream/handle/2152/61094/Weinberg_1989.pdf;jsessionid=72C4FCD78529AF994F5622C8DC805DA1?sequence=1

"The Cosmological Constant" Carroll, S. M.; Press, W. H.; Turner, E. L. (1992).
"This, as we will see later, is approximately 120 orders of magnitude larger then what is allowed by observation."
https://preposterousuniverse.com/wp-content/uploads/cpt92.pdf

General Relativity: An Introduction for Physicists (2014 ed.) Hobson, Efstathiou & Lasenby (2006), p. 187
"This gives an answer about 120 orders of magnitude higher than the upper limits on Λ set by cosmological observations. This is probably the worst theoretical prediction in the history of physics!"

The Cosmological Constant and Einstein’s Greatest Blunder

Einstein’s “greatest blunder” turned out to be a breakthrough.
The strength of the force that drives the expansion of the universe is determined by a number called the cosmological constant (\LambdaΛ).




\LambdaΛ is incredibly small. It has 120 zeros after the decimal point, and then a two. \LambdaΛ is referred to by many names, such as quintessence, dark energy, vacuum energy, zero-point energy, anti-gravity, and the fifth force.
Regardless of what we call it, all names refer to the same phenomenon: that the universe’s expansion is not slowing but accelerating.
In 1917, in an effort to explain how the universe could be static and eternal (the prevailing belief at the time), without gravitationally collapsing, Einstein introduced \LambdaΛ as a parameter to his equations of general relativity.

Albert Einstein in “Cosmological Considerations in the General Theory of Relativity” (1917) wrote:The system of equations allows a readily suggested extension which is compatible with the relativity postulate, and is perfectly analogous to the extension of Poisson’s equation. For on the left-hand side of [the equation] we may add the fundamental tensor g_{uv}guv​ multiplied by a universal constant, - \Lambda−Λ, at present unknown, without destroying the general covariance. […] This field equation, with \LambdaΛ sufficiently small, is in any case also compatible with the facts of experience derived from the solar system.

But observations by Vesto Slipher and later by Edwin Hubble and Milton Humason suggested the universe was not static, but dynamic. In 1922, Alexander Friedmann showed that the equations of general relativity could account for and describe an expanding universe.
In a final blow, Arthur Eddington, who ironically proved Einstein right in 1919 by performing the first test of general relativity, proved Einstein’s static cosmological model wrong in 1930. Eddington showed that a static universe is unstable and therefore could not be eternal.
Einstein was quick to change his mind. He said, “New observations by Hubble and Humason concerning the redshift of light in distant nebulae make the presumptions near that the general structure of the universe is not static.” He added, “The redshift of the distant nebulae have smashed my old construction like a hammer blow.”
According to George Gamow, Einstein said, “The introduction of the cosmological term was the biggest blunder he ever made in his life.”
Einstein likely considered it a blunder not for being wrong, but because he missed an opportunity. Had Einstein not tried to prove a static universe and instead looked at what his own equations implied, he might have predicted a dynamic universe before observational results came in. Einstein could have scooped Hubble.
The idea of a cosmological constant was abandoned.
But in 1980, it made a return with the theory of cosmic inflation. Cosmic inflation filled gaps in the big bang. It explained where all the matter and energy came from, why the universe is expanding, and why the density of the universe rests on a knife edge. (See: “What caused the big bang?“)
All inflation needed to get started was for the energy of the vacuum to be non-zero. If vacuum energy is non-zero, space expands on its own, exactly in the way that a cosmological constant predicts.

Alan Guth in “Eternal inflation and its implications” (2007) wrote:The repulsive gravity associated with the false vacuum is just what Hubble ordered. It is exactly the kind of force needed to propel the universe into a pattern of motion in which any two particles are moving apart with a velocity proportional to their separation.

Inflation provided an answer to one fine-tuning question. It answered “Why is the density of the universe so close to the critical density?”
But in doing so, inflation reintroduced \LambdaΛ. And the value of \LambdaΛ highlighted a fine-tuning coincidence so extreme that it’s considered one of the greatest unsolved mysteries in physics.
John Wheeler and Richard Feynman estimated that there ought to be enough vacuum energy in the space of a light bulb to boil the Earth’s oceans. Image Credit: Wikipedia
According to quantum field theory we expect the inherent energy of the vacuum to be 10^{113}10113 joules per cubic meter. A type II supernova, by comparison, is just 10^{46}1046 joules.
But when cosmologists measured the vacuum’s energy, they found it to be pitifully weak: one billionth of a joule per cubic meter. In this case, theory and experiment disagreed by a factor of 10^{122}10122!
This error is described as, “The worst theoretical prediction in the history of physics.” The question of why this prediction was so bad is called the cosmological constant problem, or the vacuum catastrophe. It remains one of the great unsolved mysteries of physics.
But there is at least one reason why vacuum energy is so low. You probably guessed: had it not been as small as it is, life could not exist.
In 1987, before \LambdaΛ was measured, Steven Weinberg predicted that \LambdaΛ must be nonzero, positive, and smaller than 10^{-120}10−120. Weinberg reasoned that had \LambdaΛ been negative, the universe would have gravitationally collapsed billions of years ago. Had instead \LambdaΛ been slightly larger than it is, say around 10^{-119}10−119, then the universe would expand too quickly for galaxies, stars, or planets to form.
In 1998, two teams of astronomers studying distant supernovae confirmed Weinberg’s prediction. They found that the expansion rate of the universe was not slowing down, but accelerating.
The observed rate of accelerated expansion places \LambdaΛ at 2.888 \times 10^{-122}2.888×10−122. This was exactly in the range Steven Weinberg had predicted, 11 years earlier. For their discovery, Saul Perlmutter, Adam Riess and Brian Schmidt received the 2011 Nobel Prize in Physics.
Eighty years after introducing it, Einstein’s cosmological constant was vindicated. The only difference is \LambdaΛ is not at a value that keeps a static universe, but instead is slightly larger, and so it drives an expansion.
Vacuum energy appears in the Casimir effect and van der Waals forces. These forces allow Geckos to climb walls and colloidal solutions like mayonnaise to hold together despite being a mix of oil and water. The same energy that holds mayo together pushes the galaxies apart.
But the probability of \LambdaΛ having the value it does is so low that it was inconceivable to physicists. There appears to be no reason it should be so small, aside from the fact that a miniscule \LambdaΛ is necessary for there to be any complex structures or life in this universe.

Leonard Susskind in “What We Still Don’t Know: Are We Real?” (2004) wrote:The fine tunings, how fine-tuned are they? Most of them are 1% sort of things. In other words, if things are 1% different, everything gets bad. And the physicist could say maybe those are just luck. On the other hand, this cosmological constant is tuned to one part in 10^{120}10120 — a hundred and twenty decimal places. Nobody thinks that’s accidental. That is not a reasonable idea — that something is tuned to 120 decimal places just by accident. That’s the most extreme example of fine-tuning.

https://alwaysasking.com/is-the-universe-fine-tuned/

Can the quantum vacuum fluctuations really solve the cosmological constant problem?
https://link.springer.com/article/10.1140/epjc/s10052-019-7554-1