3.5 The Cosmological Argument

The sections of this chapter before this section:

3.1 General and Special Relativity
3.2 Three Cosmologies
3.3 An Inflationary Cosmology
3.4 Ex Nihilo Creation

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3.5.1 Ancient and Medieval Versions
In the chapter so far, we have noted that both secular cosmology and Christian theology suggest that the universe had a beginning. We have also seen how many naturalistic scientists of the twentieth century resisted the idea of a "Big Bang" because of traditional arguments for God as Creator. In this section, we turn to the long-standing Christian tradition known as the cosmological argument, which maintains that belief in a Creator is a deeply reasonable conclusion based on the universe having a beginning.

Perhaps the first articulation of the cosmological argument did not even come from a Christian or Jew but from the Greek philosopher Aristotle in the late 300s BCE. Aristotle noted that things in motion have been moved by something else. He thus imagined things being moved now being moved by something before them. But he didn't think this sequence of one thing pushing another could go back infinitely, so he suggested there must have been a "Prime Mover." This first mover moved everything else but was unmoved itself. [1] However, he did not see this mover as a person.

In the 1200s, Thomas Aquinas would take this line of thought and Christianize it. [2] God, he argued, was this first mover. He had several other arguments for the existence of God. Probably the one of most interest to us is his argument from "efficient causes." As we observe the world around us, everything that happens has a cause. And those events had a cause. But this sequence cannot go back infinitely, he supposed. Therefore, there must have been a first Cause, which is God.

He had three more. One was an argument from contingency. Everything around us is not necessary. The Earth is not necessary. The Milky Way galaxy is not necessary. However, if everything were contingent, at some point nothing would exist. But then nothing could exist now. Surely there must be at least one Necessary entity to ground existence. And this, he argued, is God. He had two other arguments about degrees of perfection and the order of nature.

These kinds of arguments are variations on what is called the cosmological argument or the argument from cause. You might liken it to the line of the song from the Sound of Music -- "Nothing comes from nothing. Nothing ever could." And, therefore, there must be a God, a Creator.

The chief objection to such arguments is the question of why the progression cannot go back forever. In the 1700s, David Hume (1711-76) made such an objection. Just because it does not match our common sense, he argued, does not disprove that it could be so. [3]

3.5.2 Contemporary Versions
We have already seen in this chapter that the Big Bang theory answers this question of infinite regression. This is some of the reason that so many scientists of the twentieth century resisted it. As Georges Lemaître rightly observed, the idea of a beginning in cosmology directly supports the cosmological argument.

We might note some of the modern efforts to address the question of infinite regression from a philosophical and even mathematical perspective. The key figure here is William Lane Craig, who revived a medieval Islamic argument for the existence of God called the Kalaam argument. [4] A simple version of his argument goes like this:

Textbox: 1. Whatever begins to exist has a cause.
2. The universe began to exist.
3. Therefore, the universe has a cause.

Sometimes you will hear a popular response of, "Then where did God come from?" However, God does not fit within this logic because he does not have a cause. The first premise is that "whatever begins to exist has a cause." But God is not in this category.

Here is another way to put it. The argument is an argument about this universe. Everything that happens in this universe has a cause. And the universe itself as a whole would seem to need a Cause. However, God is not this universe. God is prior to and distinct from this universe. He is therefore outside this argument. We do not know if he needs a cause from this argument. Therefore, this attempt at rebuttal confuses God with the creation and is a non sequitur -- something that does not follow from the logic. 

Craig has also argued that an actual infinite does not exist in this universe. This is an intriguing concept that is attractive in many ways. Craig himself has argued for this idea by invoking the absurdity of a parable known as "Hilbert's Hotel." In this parable, there is a hotel with infinite rooms that are full. But when a new guest arrives, the clerk can simply move the person in room 1 to room 2 -- along with all other subsequent rooms -- and there is now a vacancy. In fact, by moving all the people in odd rooms to even rooms, there is now an infinite vacancy. Craig suggests that, while this seems mathematically possible, it makes little sense in the real universe.

Whatever one thinks of Craig's argument, the universe does not seem to be infinite, and the current thinking is that it had a beginning. In chapter 5, we will explore the quantum realm and realize that infinite does not exist on the quantum level either. The world cannot be divided infinitely small in space either. So it would seem that Craig is correct. While infinite may exist in mathematics, it does not seem to be a real entity in the physical universe.

3.5.3 The Attributes of God
It seems fitting to end this discussion of the cosmological argument with some possible inferences we can draw about the nature of a Creator based on cause. From a standpoint of faith, let us move beyond a mere scientific argument to one that includes faith that God created the universe out of nothing. The issue of creation would seem to be one in which science and faith are potentially in continuity. Science does not tell us what triggered the creation. Scripture may or may not specify the how of creation. The two might easily be in continuity with each other, overlapping but distinct in the questions they address.

Accordingly, let us assume by faith that the universe was created by God out of nothing. Let us assume by faith that God created not only the matter of the universe but space itself. Let us assume that God designed it thoroughly, determining what the laws of the universe would be. This is a quite different situation from a cook coming up with a new recipe using existing ingredients. The cook did not invent the ingredients or their chemical makeup. The cook did not invent the laws of chemistry that govern how those molecules will interact with each other.

No, creation ex nihilo is not something that we have any experience with. God creates the very rules and laws of this universe. Perhaps God creates the logic of this universe. What God might create in some other universe might be completely incomprehensible to us because we have no point of reference to understand it. We are exploring the concept of true and thoroughgoing creation out of nothing.

What might this imply about God? First, if God truly creates the universe out of nothing, then he must surely have as much power as he creates or more. That is to say, he must surely be omnipotent or all-powerful in relation to the creation. You cannot lift 200 pounds if you are not 200 pounds strong. By inference, therefore, God must be at least "universe-strong."

Some pose non-sensical questions like, "Can God create a rock so big that he cannot move it?" This is a game with words, the fallacy of equivocation where the same word is used with different meanings. God can lift any rock he creates because he is all-powerful. Because he is all-powerful, it is not possible that he would create a rock he could not lift. The wording makes it sound like this means he is less powerful, but that is a mere trick of wording. God can lift any rock.

A second implication is that God must surely have exhaustive knowledge of the universe he has created. Again, he is not like a cook in the kitchen. He is designing everything. God must therefore be omniscient in relation to the workings of the universe -- every possible aspect of the creation. If everything in the universe is determined, he must also know every actual dimension of the universe as well. In chapter 6, we will argue that God can know every actual aspect of the universe without determining it as well.

It can take some processing for us to begin to fathom the depths of such omniscience. Presumably, God knows all our possible experiences -- he created their possibility. God learns nothing. Emotions in God must then surely be personifications -- images to help us understand God that are not literally applicable to him. For example, anger implies reaction, but if God knows everything, then he does not react in the same way that we react as humans.

As creator of everything, God must also be the creator of the possibility of evil. We will discuss in chapter 5 the theological benefits of seeing God as permitting evil to happen rather than him being the direct cause. Nevertheless, omniscience would seem to imply that God thoroughly knows what evil is because he created its possibility.

On some of these matters, we may find out in the kingdom of God that our feeble reasonings missed the mark. After all, we are discussing the infinite and that which is beyond our comprehension. Our finite and fallen state suggests that we should approach all these questions with great humility, for we are but dust.

[1] Aristotle talks about the Prime Mover in several places, Metaphysics 1071b12–22, 1072a19–30, 1074b33–1075a11 and Physics, VIII.5–6.

[2] Aquinas, Summa Theologica, I.2.3.

[3] Hume, Dialogues Concerning Natural Religion.

[4] William Lane Craig, The Kalam Cosmological Argument (Macmillan , 1979).

3.2 Three Cosmologies

Previous writings here on the blog have included:

2.1 Relationships between Science and Faith
2.2 Critical Realism and the Coherence of Truth
2.3 Approaches to Scripture

3.1 General and Special Relativity

8.1 Approaches to Genesis 2-3
8.2 Situating Genesis 2-3
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3.2 Three Cosmologies
As the vastness of the universe became more and more apparent over the course of the twentieth century, three primary theories emerged to account for its origins and ongoing nature. At the middle of the century, the favorite was the so-called steady state theory, championed to great effect by individuals like Fred Hoyle. A small minority thought the math of general relativity might point to a beginning of the universe with something like a "big bang." The name "big bang theory" was actually given to this approach in ridicule. However, after it became clear that this was the most likely beginning to the universe, some suggested an ongoing oscillating big bang so as to avoid the need to invoke something like a Creator. [1]

textbox: Three Models:
steady state theory -- the universe has no beginning and matter is constantly being created as space expands
big bang theory -- the universe began at a point in the past in a dense hot state that has been expanding and cooling ever since 
oscillating big bang theory -- the universe begins, expands, contracts, expands again endlessly

3.2.1 Steady State Theory
After Einstein introduced the general theory of relativity, it was not long before individuals like Alexander Friedmann (1922) and Georges Lemaître (1927) recognized that the theory could point to a beginning to the universe followed by cosmic expansion. Einstein himself did not find this possibility appealing. He preferred a static universe that neither expanded nor contracted but that more or less stayed the same for all time. To counteract gravity and keep the universe static, he introduced a "cosmological constant" to his equations.

However, in 1929 Edwin Hubble discovered that the universe was expanding -- everywhere. As a light-emitting object moves away, the frequency of the waves gets elongated (like the Doppler effect when a siren is moving away from you). The result is what's called a "red shift." Galaxies all appeared to be moving away from one another, as though space itself were stretching. 

So, despite Einstein's attempt with the cosmological constant, the scientific community now had to come to grips with a universe that wasn't static at all. [2] In fact, it might very well have had a beginning. Georges Lemaître had seen this theoretical possibility of the math in 1927. He was both a scientist and a Belgian Roman Catholic priest. He saw this evidence as support for the idea of God as a Creator.

Enter Hermann Bondi, Thomas Gold, and Fred Hoyle in 1948. Finding the possibility of a "Big Bang" at the beginning distasteful, they proposed a "steady state theory." The idea was that as the universe expanded, the average density of the universe stayed the same by creating matter to fill the gaps. They proposed that about every billion years, one hydrogen atom came into being for every cubic meter in the universe. They suggested that matter is continuously being created and thus that there did not need to be a beginning (or a Creator). Thus, the universe had no beginning or end in time.

Hoyle was known for his charismatic personality. In fact, he was the one who coined the expression "big bang" for the idea of a beginning. He regularly appeared on the radio and made it easy for the public to believe that his preferred cosmological option was the best of the alternatives.

3.2.2 The Big Bang Theory
As early as 1922, Alexander Friedmann recognized that Einstein's relativity equations could be interpreted to suggest a beginning to the universe in a very dense state. Friedmann's life unfortunately was cut short in Russia by typhoid, but seven years later the Belgian scientist Georges Lemaître independently came to the same conclusion.

With the confirmation of the universe's expansion in 1929, the possibility that the universe began with a "big bang" became even more plausible. Although the expression was originally one of derision, the name stuck. Nevertheless, this option remained unpopular among naturalists until the mid-1960s. Naturalism insists on explaining all the phenomenon of the world without recourse to the existence of the supernatural or spiritual. Many naturalists resisted the idea of a cosmic beginning, since a universe with no beginning seemed to remove the need for any first cause or Creator.

Nevertheless, events that unfolded in 1965 finally settled the debate. Early, in the 1940s, scientists like George Gamow had suggested that if the universe did begin in a hot, dense, fiery state, then the leftover radiation from that fireball should be detectable still today. As space stretched, the leftover radiation would stretch into the microwave frequencies and would form a sort of cosmic microwave background (CMB) everywhere in the universe, with a temperature a few degrees above absolute zero.

It was by accident in 1965 that Arno Penzias and Robert Wilson stumbled upon this very background
radiation. They were working on a radio telescope for Bell Labs, but wherever they pointed the telescope in the sky, it was picking up a faint microwave hiss. They tried everything to eliminate possible noise sources, even cleaning out pigeon droppings inside the antenna. But the signal remained.

When Robert Dicke and Jim Peebles at nearby Princeton University heard about the situation, they immediately suspected that Penzias and Wilson had come upon the very "afterglow of creation" that for which they were planning to test. This puzzling signal was exactly what Gamow and others had predicted if the universe had begun with a "big bang." Hoyle and others were unable to account for it with their steady state theory, and the big bang theory became the primary theory for the universe's origin.

As we will see in the section on the inflationary universe, the current thinking is that the cosmic microwave background comes from around 380,000 years after the beginning, when the universe cooled enough for photons to be released universe wide. "Let there be light," you might say. If the universe were infinitely old, the background radiation would have already dissipated. The CMB is thus strong evidence that the universe had a beginning.

3.2.3 The Oscillating Big Bang
Naturalism insists on explaining the phenomena of the world without recourse to the supernatural or spiritual. However, the Big Bang theory suggested that the universe had a beginning, which raised the question of why the universe began. Theists were all too ready with an answer -- a Creator. This left the naturalist to ask what other explanation there might be.

One option came to be known as the "oscillating" big bang. As early as the 1930s, Richard Tolman had explored the possibility of "cyclic" universes. In the late 1900s, the theory revived of a universe that was in a constant process of rapid expansion, then contracting into a crunch, then expanding again in an endless, eternal cycle. In this way, the universe would have no beginning or ending. It would just be one endless cycle of expansion and contraction -- bang and crunch, bang and crunch for all eternity.

The main problem with the theory was entropy, the tendency of systems to increase in disorder and to lose heat. Each recycled universe would thus have less usable energy than the previous one. The result is basically a countdown to a universe without order -- not an infinitely repeatable cycle. Further, by the early twenty-first century, it was clear that there was not enough matter in the universe for its gravity to pull it back into a crunch. Indeed, the expansion of the universe seems to be accelerating. Its destiny could actually be a cosmic "rip" rather than a cosmic "crunch."

[1] Einstein preferred a static model in the early twentieth century, with the universe always being more or less as it is today.

[2] Einstein later called the constant a blunder, although it did turn out to be part of the equation.

Friday Science: Just Six Numbers (book review)

I have pretty much finished Hawking, but will post the rest of his book next Friday, dv.

1. I took my son to Clinton, Iowa Tuesday for him to meet in person some online friends of his that have played video games together for about six years. (Interesting development in this new world, where you go to meet some of your best friends for the first time after years of playing together. I have a nephew that first met a friend in person for the first time this spring... as best man in his wedding.) So while I was sitting in a hotel room, Starbucks, parking lots, etc, I finally read/skimmed Martin Rees' Just Six Numbers.

In the last few decades, a strong argument for the existence of God has emerged called the "fine tuning" argument. It falls under the category of an argument for design. There are a number of ratios and constants in the universe that are necessary for us to be here. An atheist at this point invokes the anthropic principle--we wouldn't be here to discuss them if there weren't. So if there are universes in the "multiverse" that do not have these precise ratios, there is no one there to talk about them. In other words, we are just the lucky ones.

By contrast, the theist says, "We are fearfully and wonderfully made." "Oh the depth of the riches of the knowledge and wisdom of God!"

Rees' book is about these constants. I am now working on my third Gabriel novel. This one is called Gabriel's Diary: The Creation. It is going to be truly spectacular and probably a bit controversial. I am hypothesizing what creation might look like from a Christian point of view that engages with contemporary science. I'm not saying it's right. But it will be a book for people who are convinced about the science but not so convinced about God. The first three chapters will embody the fine tuning argument and engage my feeble apprehension of modern cosmology.

2. Here is a summary of my take-aways from Rees' book. I have put them in the order that is most helpful for my writing. Fine tuning arguments are in bold.

Chapter 1: The Cosmos and the Microworld

• Rees goes with the anthropic principle and the multiverse model: "An infinity of other universes may well exist where the numbers are different. Most would be stillborn or sterile. We could only have emerged (and therefore we naturally now find ourselves) in a universe with the 'right' combination" (4).
• He uses an "ouraborus" to picture the scale of the universe. The breadth of size is 10⁶⁰. The smallest size imaginable is about 10^-33 cm. The universe is about 10²⁸ cm across. (These are my numbers, not his.)

Chapter 3: The Large Number N: Gravity in the Cosmos

• He calls the constant discussed in this chapter, N. I've never heard of it but he is referring to the ratio between the electromagnetic force and the force of gravity. It turns out that the electromagnetic force is about 10³⁶ times more powerful. 
• Gravity is always attractive, while electromagnetic forces can be either attractive or repulsive. So with large objects, gravity accumulates a large attractive force, while the electromagnetic forces more or less even out.
• There is an inverse square law that applies to these two forces. The force weakens as the square of the distance increases. More on the significance of this fine tuning in chapter 10.
• Gravity makes objects as big as the Moon and larger spherical.
• If the ratio were less, everything would be smaller--smaller stars, smaller planets, potentially smaller life. Galaxies would form quickly and would be miniaturized. They would be more densely packed.
• Stellar lifetimes would be much shorter, which according to Rees would not have given enough time for complex life to evolve. 
• A weaker gravity might have allowed more elaborate and longer-lived structures to develop, but a stronger gravity would not have allowed enough time for humanity to emerge.
• A little on Einstein - the speed of light is the speed limit of the universe. Near large masses time slows down relative to elsewhere.
• Millions of black holes in our galaxy, the remnants of large stars that have already burnt out. Slightly smaller stars become neutron stars. Our Sun will become a white dwarf when it burns out.
• Some explanations of black holes, event horizons, etc., atomic sized black holes.

Chapter 10: Three Dimensions (And More)

• The number he discusses in this chapter is 3, three-dimensions of space.
• In a three dimensional world, forces like gravity and the electromagnetic force obey an inverse-square law mentioned above.
• William Paley used the inverse square law as part of his argument from design. If it were an inverse cube law, there could be no orbiting of planets or electrons around a nucleus.
• There is an asymmetry of the arrow of time. "No such asymmetry is built into the basic laws governing the microworld" (153). The asymmetry is linked to the expansion of the universe. [Hawking calls this the cosmological arrow. Entropy is another basis for the arrow, which Hawking calls the thermodynamic arrow.]
• The expansion of the universe was fast enough to end nuclear reactions before they could convert more than 23% of the hydrogen into helium. This left fuel for suns.
• There was just the right asymmetry in the earliest phase to leave a slight excess of matter over antimatter. Otherwise, nothing but energy would be here.
• He also talks a little about Planck units. The smallest length is 10¹⁹ times smaller than a proton, 10^-35 the length of a meter. The smallest unit of Planck time is 10^-43 seconds. Space and time are arguably granular, not continuous. Take that, Zeno.
• He mentions superstrings. I believe this approach is increasingly discredited.

Chapter 9: Our Cosmic Habitat III: What Lies Beyond Our Horizon?

• Helium was formed at about the three minute threshold.
• grand-unified (all forces united) to quarks (strong from electroweak) to leptons (electro from weak)
• magnetic monopoles?

Chapter 8: Primordial Ripples: The Number Q

• Q is the ratio between the rest mass energy of matter and the force of gravity. It is 1 to 100,000. 
• It has to do with the "roughness" of space, the "ripple amplitude" of the gravitational waves of cosmic inflation.
• It has to do with the energy that would be needed to break apart galaxies.
• The slight asymmetry of the universe seems to relate in some way, enabling things to form structures.
• If Q were smaller, galaxies wouldn't form. If Q were larger, galaxies would crunch much sooner and the universe would be a rougher place.

Chapter 6: The Fine-Tuned Expansion: Dark Matter and Ω

• What Rees calls Ω is the ratio between the force of universe expansion and the force of gravity. This ratio determines whether the universe will expand forever, expand steadily, or eventually contract again. These correspond to whether the ratio is less than 1, exactly 1, or greater than one.
• Because of gravity, if there were five atoms for every cubic meter in the universe, it would contract one day. As it is, there only seems to be 0.2 atoms per cubic meter, at least as far as ordinary matter is concerned.
• All the indications are thus that this number is less than 1. But it is likely that there is "dark matter" out there, stuff we can't see. It is thought that about 26.8% of the universe is dark matter.
• Candidates for dark matter include brown dwarfs (suns less than 8% of our sun's mass), neutrinos, black holes, "axions," but more likely something we don't yet know about.
• At about one second after creation, Ω could not have differed from 1 by 1 in 10¹⁵. If the expansion force were greater, there would have been no time for stars and galaxies to develop. If the mass were greater, the universe would have collapsed too soon for life as we know it to develop.
• Another fine-tuned factor is the slight asymmetry between matter and antimatter. If there were perfect symmetry in the early universe, they both would have emerged in equal amounts and completely annihilated. But there must have been a slight asymmetry.
• There are different suggestions for the asymmetry. Rees suggests the K° decay, associated with the weak nuclear force, may be the reason. What if, for every billion quarks and antiquarks generated in the earliest universe, one extra quark were produced?

Chapter 7: The Number Λ: Is Cosmic Expansion Slowing or Speeding

• As far as I can tell, Λ doesn't contribute much more than the discussion of omega in the previous chapter. 
• Einstein added Λ to his general relativity equations with the hope of a universe that wasn't expanding. He regretted that when Hubble showed it was. But there does seem to be an unknown force that is affecting comic expansion. This was apparently confirmed in 1998.
• It is relatively small, about 0.7. It is a force driving expansion.
• [It seems to relate to what scientists now are calling "dark energy."]

Chapter 5: Our Cosmic Habitat II: Beyond Our Galaxy

• Galaxies are the building blocks of the universe. Stars and their solar systems collect together to form galaxies. Galaxies often have huge black holes at their centers. Galaxies cluster (our cluster is the "Local Group").
• Galaxies crash into each other. The kind of galaxy known as elliptical galaxies may be the result of galaxies that have crashed into each other. [Hawking had a different thought here in the 80s.]
• There are bigger aggregates like the "Great Wall."
• At every point we look in space, everything is speeding away from us, often faster than the speed of light, which suggests that space itself is expanding, since nothing can move faster than the speed of light in its own reference frame.
• The expansion of space has been well established in the last fifty years. [When Hawking wrote, he hoped it might crunch again but we seem rather headed for a cosmic rip from accelerating expansion.]
• Cosmic Microwave Background radiation (CMB) discovered in 1965 points to a Big Bang. Together, the fact that the universe had a beginning coupled with the fact that it won't re-compress fits well with the notion of creation.
• CMB comes not from the creation itself but from some 380,000 years after the beginning (13.8 billion years ago) when the universe cooled down enough for electrons and protons to form neutral atoms, releasing a massive amount of energy in photons.

Chapter 4: Stars, the Periodic Table and ɛ

• A third number is ɛ, which I've never heard called that, but which is the percentage of mass released as energy when hydrogen is fused into helium. 0.007 or 0.7%
• This has to do with the strength of the strong nuclear force that binds protons and neutrons together in a nucleus. This force is the strongest of all the forces but it only works within the space of a nucleus. It is thus just strong enough to hold a nucleus together without interfering with the electromagnetic forces that are essential for the overall working of an atom or the weak nuclear force that comes into play with large atoms with atomic numbers over about 50.
• Helium is fused in two stages. First, a proton and a neutron fuse together to form deuterium (heavy hydrogen). Then two deuterium atoms fuse together into helium. 
• If the percentage converted to energy were any more, no hydrogen would have survived the big bang. It would have all become helium or heavier, leaving no fuel for stars. If it had been less, no helium would have formed and the universe would just consist of hydrogen.
• Carbon only forms from a helium and beryllium nucleus because the carbon nucleus has a resonance with a very specific energy that can fuse just before primitive beryllium decays. Without carbon, life as we know it would not exist.
• The Earth is thought to be about 4.5 billion years old. The universe about 13.8 billion.
• When a star's hydrogen has all been converted to helium, the core pulls inwards. Prior to that time, the energy from the fusion pushed back against the gravity of the mass.
• When it contracts, it heats up more and heavier nuclei are formed. Iron is the most tightly bound nucleus. When it gets to a critical size, it implodes to a neutron star and supernovas the overlying material. In this material are the trace elements of heavier elements.

Chapter 2: Our Cosmic Habitat I: Planets, Stars and Life

• Stars start as warm blobs ("protostars"). They contract over millions of years under their own gravity. 
• Any slight spin is amplified under a collapse, like a skater pulling in arms. The resulting disks are the precursors of planetary systems. (14)
• Small wobbles in the orbits of stars may indicate planets. Christiaan Huygens in 1698 suggested every star might have planets around them. These are now considered certain.
• A "barycenter" is the center of mass of an orbiting pair like the sun and Jupiter.
• The early history of a solar system is filled with crashes. (A huge crash 65 million years ago (crater underwater in Gulf of Mexico near Chicxulub is thought to have killed the dinosaurs.) This event paved the way for mammalian life to emerge as winners.
• The Moon is thought to have been formed from the earth by a collision with another protoplanet. Uranus' weird axis spin also explained by such collisions.
• For life to exist on a planet like Earth, gravity must pull strongly enough to prevent the atmosphere from evaporating into space but it can't really be any stronger than Jupiter (cf. 32).
• For water to exist on the surface, planets must be neither too hot or too cold.
• The orbit must be stable, not crossed by a Jupiter-like planet in an eccentric orbit.
• The oxygen of our environment is thought to come from primitive bacteria early in earth's history.
• Cf. p32. Gravity makes objects Moon sized and larger spherical.

Chapter 11: Coincidence, Providence - Or Multiverse

• Rees goes with the multiverse theory. It is a logical option for someone who doesn't believe in God as creator. It doesn't preclude God, although it might push creation back further. It seems more philosophical in some ways rather than scientific per se.
• He suggests that the values of these constants might be difference in other universes.

Quantum Physics, Cosmology, and God

David Higle and I were exchanging emails about sources on quantum physics and theology. He already knew everything I thought of, especially Polkinghorne's Quantum Physics and Theology. I'm on a slow train pursuing these things, but thought I would give a snapshot of musings.

1. Big Bang
Contrary to some rhetoric, I've long thought that the idea of a Big Bang plays right into Christian theology. Why? Because it suggests a beginning of sorts to the universe. If the universe had a beginning, then we can ask why it began. In other words, the Big Bang seems to play right into the cosmological argument for the existence of God.

The current theory is:

• The universe had a beginning--matter is not being eternally created somewhere (steady-state theory).
• It does not have enough mass to re-collapse, meaning it probably has not been banging in some eternal cycle (oscillating big bang).
• That suggests a beginning, which leads us to ask, "Why?" "What caused it?"

Cosmological theory has developed significantly over the last couple decades, but I think it still more or less amounts to the same thing. At 10^-43 seconds, all the universe was in a ball the size of 1.6 x 10^-33 meters. In the next moment, it expanded astronomically to something much closer to its current size.

2. Quantum Uncertainty
In the 1600s, Newton reinforced a deterministic universe, where all the future could be predicted as the simple playing out of laws and objects in motion. It fit well with the theology of Calvin and Hobbes.

The quantum world is not a deterministic world. It is an indeterministic world. That is to say, you cannot predict the future at all on an individual scale. All you can predict are the averages. There are still some who think there may be "hidden variables" that would return us to determinism, but most do not agree.

This suggests that the universe on some level has a mind of its own. There is an unpredictability to the universe. You cannot predict what I will do (I can't either) because there is a fundamental uncertainty at the bottom of everything. It is not exactly free will as we once might have thought of it, but it is similar.

3. Quantum entanglement
Certain particles are entangled with each other after they part. They may be on opposite sides of the universe but if you know what the one is doing then you know what the other is. I'm not sure what the implications are for us. I once tweeted that God has been quantumly entangled with the whole universe since the creation, implying that he knows everything and is connected to everything. But is was really more of a poetic thought than something that actually makes sense. :-)

4. Time
It is not clear what time is. Each frame of reference has a certain internal clock of sorts, meaning that "time" moves at different rates for different things. From one perspective, time is merely the rate at which things change, with light as the ultimate speed limit.

Time is a puzzle on the quantum level. In one respect, there is no real difference between past and future on the quantum level. All processes are reversible.

On the macro-scale, entropy is what really tells time. The loss of heat in disorder seems to be the only truly irreversible aspect to this universe. It tells time.

What does this say about God? It does suggest that entropy is not a consequence of the Fall. There would be no past or future without it.

It doesn't help us figure out God's knowledge of the future. How do we know how God knows what he knows? He was "outside" the universe "before." Who knows what that means for during and after?

That's it. My attempt for today...

Rovelli 5: Fundamental Constants of the Universe

This is my fifth post on Carlo Rovelli's new book, Reality Is Not What It Seems. The first three posts were:

• From Democritus to Relativity to Quantum Mechanics
• Spacetime is Quantum
• Quanta of Space
• Time Does Not Exist

1. Chapters 8-11 are fairly short. Some of it covers basic material from cosmology but there are some helpful synthetic thoughts too.

Chapter 8 fills in some gaps with regard to the Big Bang. He gives high praise to Georges Lemaître, a Belgian priest, for supporting the idea of a "primordial atom" even though Einstein strongly disagreed. Einstein's equations seemed to suggest that the universe was expanding, but he didn't want to believe it. In fact he added a "cosmological constant" to his equations to fix it (Λ). Lemaître turned out to be right about expansion.

Then Einstein lamented adding the cosmological constant and wanted to remove it. Again, Lemaître suggested he should leave it. Lemaître proved to be right again over Einstein. So in both cases Rovelli writes, "It doesn't fall to everyone to disprove Einstein" (204).

Then Lemaître stopped the Pope, apparently, from making the Big Bang official church belief. Again Rovelli says, "It is not given to everyone to disprove the pope" (205). This falls under the principle of not inserting God too dogmatically into your scientific theories, because theories change.

2. Rovelli favors something he calls "the Big Bounce." The idea here is that "our universe could be the collapse of a previous contracting universe passing across a quantum phase, where space and time are dissolved into probabilities" (208). This seems to me to be a form of the oscillating Big Bang theory.

I thought that the current sense of things was that there was not enough matter in the universe to pull everything back together and thus that the universe was headed for a "Big Rip" at the end of things. This is also different from the multiverse idea that other books I've read have suggested, namely, that our universe is just one of an infinite number of universe bubbles.

Meanwhile, Rovelli nicely, I think, counters Lee Smolin's sense that the universe is all there is by definition. Rovelli, much more soundly says, "The word 'universe' has assumed another meaning in cosmology: it refers to the spacetime continuum that we see directly around us, filled with galaxies and history of which we observe. There is no reason to be certain that, in this sense, this universe is the only one in existence" (208).

Take that Smolin, who says in the first chapter of Quantum Gravity, "By definition the universe is all there is" (17). Let's just say Rovelli is a much better philosopher, although I don't always agree with him.

The dissolution of spacetime into a cloud of possibilities when you have that much mass at a quantum size is an intriguing idea.

3. Chapter 9 asks if we have any experimental evidence for loop quantum gravity. A number of times he pushes back both against those who say you cannot talk about anything that you cannot now experimentally show and those who wildly speculate detached from current trajectories. To me this positioning makes perfect sense.

On the one hand, a theory should proceed to experimentation. "A theory lacking empirical confirmation is a theory that has not yet passed its exams" (212). On the other hand, he disagrees with wild hypotheses. "Many theoretical physicists are today looking for new theories by picking arbitrary hypotheses... I don't think that this way of doing science has ever produced good results" (215-16).

Rather, all the experimental evidence has been confirming the three cornerstones of modern physics: general relativity, quantum mechanics, and the Standard Model within quantum mechanics. The new findings have brought a complete absence of surprise. Hawking was disappointed.

The three big findings of this decade are 1) the confirmation of the Higgs boson, 2) the cosmic measurements of the Planck satellite, and 3) the detection of gravitational waves.

Also, the fact that CERN has not discovered supersymmetry is a blow to string theorists, which is why Sheldon on Big Bang Theory went looking for something else to study. :-)

4. Mapping of the cosmos has given us a sense of the lay of the background radiation left not too long after the so called Big Bang. The idea here is that it took some time for the universe to cool down enough for the light (photons) of creation to be released.

The remnants of this release are called "cosmic background radiation" (CBR), alleged to have happened some 380,000 years after the Big Bang.

Apparently, if LQG is correct (loop quantum gravity), then there should also be a gravitational background radiation. An experiment called LISA involving three satellites around the sun, might be able to test for these.

5. Chapter 10 looks at quantum black holes. There are black holes at the centers of most galaxies and, in at least one theory, they may account for what it otherwise called dark matter.

The horizon of a black hole is the point where you might stay out. Past that, nothing can get out. Time stops at the horizon. Stephen Hawking's claim to fame was his discovery that black holes slowly evaporate. Eugenio Bianchi showed that loop quantum gravity can also demonstrate Hawking's formula for the heat of a black hole.

What LQG would show is that, since spacetime is not infinitely divisible--since it never can reach a singularity--at some point a black hole should explode in a miniature version of the Big Bang. From our perspective outside a black hole, this would take billions years, even if it is only moments inside the black hole. Since the universe is allegedly 14 billion years old, we might find some of these. Rovelli suggests that some "fast radio bursts" detected by radio telescopes could be such.

6. Chapter 11 is called the end of infinity. The common sense of the suggestion here is so obvious I've thought of it for some time now and I'm not even a scientist. Why didn't Dirac and Feynman? Quantum mechanics and relativity are plagued with infinities. Feynman the pragmatist simply substituted the experimental values for certain infinities to get his equations to work.

But LQG, because it sees space as quantized, eliminates the infinities. This seems so obvious to me that it is surprising it is not a fundamental working assumption of modern physics.

"Putting a limit to infinity is a recurrent theme in modern physics. Special relativity may be summarized as the discovery that there exists a maximum velocity for all physical systems. Quantum mechanics can be summarized as the discovery that there exists a maximum of information for each physical system. The minimum length is the Planck length L_P, the maximum velocity is the speed of light c, and the total information is determined by the Planck constant h" (232).

Now we are getting somewhere. This is what I've been thinking and looking for someone to put succinctly like this. "The existence of these minimum and maximum values for length, velocity, and action fixes a natural system of units. Instead of measuring speed in kilometers per hour... we can measure it in fractions of the speed of light.. In the same way, we can posit L_P = 1 by definition and measure length in multiples of Planck's length. And we can posit h = 1 and measure actions in multiples of Planck's constant. In this way, we have a natural system of fundamental unities from which the others follow" (233).

One more seems to complete Rovelli's set, namely, the cosmological constant (Λ) used in relativity. I have a book called Just Six Numbers that is also on my reading list. I'm hoping it will help me understand the importance of the ratio between the cosmological constant and the Planck length.

My next post should finish the book.

Friday Science: Cosmic Inflation

Another chapter of Brian Greene's, The Fabric of the Cosmos. I'm now within 200 pages of the end. My first nine summaries are at the bottom.

I thought I would quote his summary of this chapter from p. 301 and then add some "expansionary" comments:

1. "Early on, the energy of the universe was carried by the inflaton field, which was perched away from its minimum energy state."

The current majority opinion is that the "bang" of the big bang did not happen immediately but a small fraction of a fraction of a fraction of a second after zero (let's call it creation). Measurements indicate that the universe is expanding. And yet the temperature of the universe as a whole is more or less the same.

Alan Guth and Henry Tye realized in 1979 that if the Higgs field paused for the briefest of fractions at a not quite minimum value ("supercooled"), a special situation would be set up where gravity didn't attract but actually would repel at a tremendous value. This could explain how the universe could go from a speck to its massive size in a fraction of a fraction of a second.

2. "Because of its negative pressure, the inflaton field drove an enormous burst of inflationary expansion. Then, some 10^-35 seconds later, as the inflaton field slid down its potential energy bowl, the burst of expansion drew to a close and the inflaton released its pent-up energy to the production of ordinary matter and radiation."

So this would explain the "horizon problem," the fact that microwave background radiation is basically the same wherever you look in the universe. All the parts of space we see were once touching each other. Another problem it eventually helped solve is the "flatness problem."

The density of the universe would seem to be just right for a flat universe--at least as far as we can see. Nebraska seems flat when you're standing in it. But in the light of the earth, it isn't. But the matter/energy density of the universe seems just right, a "critical density." This is quite astounding at first glance. If it were a little more or a little less, we would think we would observe a vast difference today from what we do.

But repulsive gravity apparently pushes the value of the matter/energy density toward its critical value, so that space in our neck of the woods at least looks flat. Also, repulsive gravity seems to have gone "slower" at the beginning of the fraction of a fraction of a fraction of a second so that the temperature could even out (cf. Andrei Linde, Paul Steinhardt, and Andreas Albrecht).

3. "For many billions of years, these familiar constituents of the universe exerted an ordinary attractive gravitational pull that slowed the spatial expansion."

There is a bit of a puzzle in that, while the universe seems to fit with the critical density being the case, we can only observe 5% of matter and energy toward what that amount should be. Starting in the 1930s, there was a suggestion that some sort of matter we cannot see must be out there, keeping the stars of the galaxies we see from flinging out of them.

Thus the idea that there is some sort of "dark matter" out there has been around a long time. And it seems to account for another 25% of the matter/energy we would need for the critical density number that fits with observation to be realized.

4. "But as the universe grew and thinned out, the gravitational pull diminished. About 7 billion years ago, ordinary gravitational attraction became weak enough for the gravitational repulsion of the universe's cosmological constant to become dominant, and since then the rate of spatial expansion has been continually increasing."

By "cosmological constant," Greene refers to a debate that goes back to Einstein. Einstein didn't like the idea of an expanding universe, so he suggested a constant in his equations that held the universe static. When Hubble observed in 1929 that the universe was expanding, Einstein was embarrassed for letting his sense of how the universe should be interfere with his equations.

Years later, though, something like Einstein's constant seems to be in play. In particular, careful measurements in the 1990s suggest that the universe suddenly began to speed up big time at some point. If something else was functioning something like the constant Einstein had speculated about, it would explain it. In fact, if the remaining missing 70% of the matter/energy density were some kind of "dark energy" we can't see, that would do it.

And so there is the current suggestion. The observable universe is only 5% of the matter/energy that exists. Another 25% is a kind of matter we cannot observe ("dark matter") that holds galaxies together. The remaining 70% is a kind of energy we cannot observe ("dark energy") which is responsible for the massive acceleration that started about half-way through time. It will eventually result in a cosmic rip where the universe looks very dark and empty indeed.

Reality's Arena
1. Overview
2. Spinning Space Buckets
3. Relativity and the Absolute
4. Particles Separated at Birth

Time and Experience
5. Does time flow?
6. Does time have an arrow?
7. Quantum crazy

Spacetime and Cosmology
8. Universal symmetry
9. The Higgs Ocean

Friday Science: Universal Symmetry

One day I'll finish this book: Brian Greene's, The Fabric of the Cosmos. My first seven summaries were:

a. Overview
b. Spinning Space Buckets
c. Relativity and the Absolute
d. Particles Separated at Birth
e. Does time flow?
f. Does time have an arrow?
g. Quantum crazy

1. This chapter was about symmetry in the universe, and I found it much more enjoyable than the last two (maybe because I understood it better). Greene suggests that perhaps the most significant finding of modern science is that "Symmetry underlies the laws of the universe" (219).

You can move from here to there (translational symmetry). You can rotate (rotational symmetry). You can transport across the galaxy. The same laws work everywhere. You can move at a constant velocity and Einstein says the laws will work the same. You can accelerate, and Einstein's general relativity says the laws work the same. "Symmetries are the foundation from which laws spring" (225).

2. Time of course is not currently symmetrical. "The existence of time thus relies on the absence of a particular symmetry" (226).

But the cosmos is fantastically uniform on a large scale. Cosmic background radiation is amazingly uniform everywhere. This bespeaks 1) to the young universe being homogeneous and 2) to the development of the cosmos being nearly identical everywhere. It also suggests that time has generally elapsed the same everywhere in the universe as well.

The universe is expanding. Interestingly, the more distant the galaxy, the faster it is receding--and in every direction. The general consensus is that space itself is swelling. Space is getting bigger. Every point in the universe is moving away from every other point like pennies taped to a balloon you are blowing up. There is no center.

3. So if there were clocks taped to a universal balloon, they are all ticking the same, even though the expansion of space is causing them to move rapidly away from each other. They are not moving through space but space is "moving" between them. So some parts of the universe may seem to be moving faster than the speed of light, but it is rather a consequence of the space expanding between things.

The chapter also looks at the shape of space. It isn't really known, but an infinitely flat space is possible, perhaps even the leading contender according to Greene. Other possibilities are a spherical shape, a saddle shape, and a Pac Man flat screen where you leave one side and come back on the other.

Friday Science: Inflation before the Bang

Review Post #3

I've been working my way through Max Tegmark's, Our Mathematical Universe. My post on the first two chapters is here. My post on the third chapter is here.

1. Today I want to cover chapters 4 and 5. I can't believe how much has been happening in cosmic science these last few years. It feels like the cutting edge of science is moving faster than most of us could imagine. It feels like you have to be way smarter to be part of it than ever before. Man I feel old.

So chapter 4 includes some interesting claims. According to the latest estimates, only about 3% of the cosmos is ordinary matter. To get the expansion rate correct, about 68% of the universe would need to be "dark energy," where this is energy we cannot observe that does not cluster to form galaxies and such. It is energy that has a repulsive gravitational effect (77). Then 27% of our universe would be "dark matter," matter that we cannot observe that contributes to the mass of the universe that does affect the clustering of ordinary matter into galaxies.

I don't particularly like the concept of dark matter and energy. They sound like things we make up because our theory is wrong. (They remind me of an old notion called phlogiston). But Tegmark assures us that the numbers have been suggested from more than one universe measurement.

The chapter goes through some of the chase that arrived at these numbers. They mostly seem to derive from precision measurements of fluctuations in cosmic background radiation (a chart on p.72). The "cosmic matter budget" is also said to explain how the total cosmic density can be 10 to the 10th power lower than water and how space can be flat.

2. I would need to reread these chapters to put everything together better. The current thinking seems like something that could be radically reconceived if an Einstein came along, but Tegmark certainly gives the impression that the current thinking is pulling together toward the same conclusions from multiple directions. So I'm writing them down in construction pencil, although some of these findings are far enough along that Nobel Prizes have been awarded.

According to the varied measurements, the universe is currently thought to be about 13.7 or 13.8 billion years old. The "big bang" for Tegmark was a point near the very beginning where the universe doubled its size in under a second. It spent the next few minutes fusing about 25% of total hydrogen into helium. Then this hydrogen-helium plasma cooled for about 400,000 "years" (Gamow), after which the clumping and expansion took place that has resulted in the current visible universe with its swirling galaxies and such.

3. In chapter 5, Tegmark pushes back before this cosmic "big bang." I understand now a little better what he meant when he said that the big bang is not exactly the beginning. If I am getting it right, there is about a third of a second before this "big bang" that needs to be explained. (I have a couple other books I really need to read--Hawking's Brief History and a book called The First Three Minutes).

The key players here are Alan Guth and Andrei Linde. Guth addressed a "horizon problem." Why is the universe the same temperature when there are parts of it that one might say have never touched? Another problem is the "flatness problem." I'm not entirely sure what it means to say that the universe is flat, but apparently, it is balanced exactly right like a bike standing up without a kick stand.

Guth's suggested explanation was "inflation." In 10 to the negative 38th power seconds, the mass of the universe doubled 260 times. It borrows the energy to create this mass from gravitation, if I understand correctly. The gravitational waves which were observed last year are a prediction of this model.

At the end of this chapter, Tegmark suggests that this inflation has never stopped. It's just that it stopped in our pocket of the universe. Following Alex Vilenkin, about a third of the inflating substance of the universe "bangs" into galaxies while the rest continues to inflate beyond our sight. So our "Big Bang" was really the end of inflation in our part of space.

Meanwhile, inflation can, according to general relativity, create an infinite volume inside a finite volume. So our universe began "inside" a space smaller than an atom.

4. Well now. I don't know enough even to understand, much less evaluate these strange theories. But I will read on. I was struck by the tenuousness of it all, how the numbers need to be just right to get what we have. The anthropic principle, which seems to fit nicely into an argument from design.