Initial Condition of Universe

Copyright © 1994 by Tienzen (Jeh-Tween) Gong

Are laws of creation different from and independent of laws of physics? In order to answer this question, we must first review the question of initial condition at or before the Big Bang.

In cosmology, there are two key issues -- the amount of matter and its distribution in the universe. These two issues then give rise to many other issues -- the geometry of the universe, the initial conditions, the evolution of the universe, etc..

I: The Cold Dark Matter Model

In the early 1930s, Fritz Zwicky pointed out that many galaxies were moving and rotating much faster than the amount of visible matter in them can hold them together with gravity force. Forty years or so later, this missing mass phenomenon was rediscovered as a missing radiation problem, that is, there must be some dark matter in those galaxies.

What are those dark matter? There are basically of two types -- baryonic and fictitious dark matter. The baryonic dark matter is made of particles we know of. The black holes, brown draft stars, intergalactic hydrogen clouds, blue (very old and distant) galaxies and neutrinos are baryonic dark matter. These type of baryonic dark matter do indeed exist. Although they are invisible themselves, they can be detected with other means, such as the absorption spectrums and the gravitational lenses. With those baryonic dark matter, the missing mass issue for galaxies can be resolved.

Then, why shall we contemplate any fictitious dark matter, such as squarks or sleptons, etc.. As I mentioned in previous TOE papers, those fictitious matter were predicted by supersymmetry which was only a half-right idea. Although those fictitious particles have never been observed in laboratories around the world, many physicists and cosmologists believe in them because our universe sort of needs them.

There are three possible geometry for the universe -- open, flat or closed. These three possibilities are described with a fundamental cosmological number know as omega. Omega is the ratio between the density of matter there really is in the universe and the amount it would take to slow the expansion forever but never stop it.

If omega is small than one (1), the universe will expand forever and reach a heat death which is a state of uniform temperature (that is, at absolute zero degree of kelvin). If omega is larger than one (1), the universe will eventually stop expansion and begin to contract into a Big Crunch, the ultimate inferno. Both of these conditions will eliminate the human race eventually. But, if omega is equal to one (1) exactly, then the universe will expand forever but with a smaller and smaller rate. In this case, there is a chance for civilizations to build bio-islands in that universe and thus to last eternally.

Today, omega appeared to be about .35, based on a rough estimate of the number of galaxies in the universe and the presumed weight of each, which includes all baryonic dark matter. Seemingly our fate has set; we will face the heat death on the judgement day.

Not so! Most of physicists and cosmologists believe that omega must be exactly equal to one, and we simply haven't found the missing 65%. Their faith comes from two reasonings -- anthropic and teleological.

The anthropic argument: If omega was less than one at early stages of universe, it will be close to zero by now after 15 billion years of evolution. If omega was larger than one at early stages of universe, it will be close to infinity by now. In both cases, we would not be here to discuss what value omega is. The fact we are talking about it implies that omega must be exactly equal to one at all time.

The teleological argument: The universe has some deep meaning, and part of that meaning is ourselves. In order to avoid the heat death or inferno and to perpetuate these meanings, the omega must be equal to one.

At any rate, if omega is equal to one exactly, then there must be some non-baryonic dark matter. Those fictitious matter predicted by supersymmetry thus become the foundation of a new cosmology theory -- the CDM (Cold Dark Matter model).

Why cold? What does it mean? Cold is the opposite of hot. In cosmology, neutrino is called hot dark matter. The temperature of those dark matter is defined in terms of the free streaming scale.

The free streaming scale is determined by the time it would take a blob of particles to collapse under gravity versus the time it takes the typical particle to traverse the blob.

When baryons try and form into a blob, there are two competing forces at work: gravity, which makes the blob want to collapse, and pressure, which resists collapse. For neutrinos, there is no such thing as pressure, since the particles don't even notice each other, let alone other matter or light. This tendency to boil off into space is the reason it is called hot.

The free streaming scale for neutrino is a least ten thousand times bigger than the size of an average galaxy. If neutrinos were the dark matter to bring omega to one (1), then the most fundamental mass concentrations in the universe should be supercluster instead of galaxy. It also means that a neutrino-dominated universe shall form structure on the largest scales first, and on the scale of galaxies last. But, there is strong evidence that the reversed order is true, that is, galaxies formed first, the superclusters last.

Furthermore, because of its large free streaming scale (being too hot), the neutrino cannot be packed too tightly. It means that galaxies much smaller than the Milky Way shouldn't have significant dark halos at all, but observation of the dwarf galaxies show that they do have massive dark halos.

Now, it is clear that neutrino cannot be a major factor to bring omega to one (1), if it plays any role at all. So, cosmologists must find some colder dark matter if they insist that omega ought to be one (1). They must be cold enough to allow galaxies to form first, that is, their free streaming scale must be equal to the size of galaxy.

A big zoo of those kind of cold dark matter was dreamed up by physicists. Since they are fictitious particles, their temperature (hot or cold) can be assigned arbitrarily depending upon the needs of the physicists. No one can prove one way or another anyway. Gravitinos are considered to be warm. The photino, the supersymmetric counterpart of photon, is cold.

The original cold dark matter model (CDM) consists of three components. First, CDM claims that omega must be equal to one (1) exactly. Since the observed omega is much less than one, there must be dark matter. Second, these dark matter must be cold, which is to say that their characteristic speed as they whip through the universe is much slower than the speed of light. Third, the universe went through a period of incomprehensibly rapid inflation before it was far into its first second of life; it increased in size by an astounding factor of 30th power of 10 in a fraction of a trillionth of a second before the explosive expansion of the Big Bang.

Under this CDM, the cosmos should have a hierarchy of structure, with galaxies huddled together into clusters of galaxies, and the clusters gathered into superclusters. For almost a decade, the universe looked seemingly exactly like the CDM model. But by 1986, two independent sky surveys discovered Giant Bubbles and the Great Wall. In a universe dominated by CDM, those newly discovered cosmic objects are too big to exist comfortably.

In order to overcome these new difficulties, cosmologists dreamed up a fourth component to add into the original CDM. It is called biasing, that is, the galaxies formed not everywhere, but only in the most densely packed regions of dark matter.

All these four statements of CDM are unproven. The first statement came from a religious craving, sort of at least. The second statement on the one hand is demanded by the known structure (galaxies first, superclusters last) of cosmos; on the other hand, it claims that many fictitious particles (squarks, photinos, etc.) to be realities. So, these first two statements are sort of science fictions.

On the contrary, the fourth statement is demanded by some new observations, but the most important of all is the third statement. If CDM is a genuine science theory at all, it is because it contains this third statement -- the inflationary scenario.

The inflationary scenario was proposed by Alan Guth in 1980. This new idea solved three long standing cosmological issues -- the horizon problem, the flatness problem and the large-scale structure problem -- at least on the observational level if not on the metaphysical level.

Today, the prevailing view is that our universe is about 15 billion years old. When lights from two opposite sides of universe took 15 billion years to reach us, it means that they could never have been in causal contact at any stage of their entire history. This is the horizon problem.

According to the Big Bang theory, the universe shall become more curved as time passes. But observation reveals that the spatial geometry on the part of the universe we can observe is extremely flat, although it may indeed be curved at some scale far beyond the horizon. This is the flatness problem.

In order to understand the large scale structure problem, we must first discuss the Copernican Cosmological Principle.

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II: Copernican Cosmological Principle

In 1510s, Nicolas Copernicus formulated a cosmological principle which declares: the Earth does not represent a special observation position. This principle was later expanded to contain two statements. First, the universe looks identical in whichever direction we look, that is, it is isotropic. Second, it goes one step further, that the universe is isotropic as seen from any other point, which is known as homogeneity. A homogeneous and isotropic universe has the greatest possible degree of spatial symmetry and the simplest spatial structure.

With this Copernican Cosmological Principle (CCP), many predictions about the structure of cosmos can be made, and many of them were proved to be true. The first prediction is the Olbers' paradox in an infinite universe: Why does it get dark at night? In 1823, Heinrich Olbers showed with a simple mathematical model that the night sky ought to be as bright as day if the universe is infinite in size and if the CCP (Copernican Cosmological Principle) is true. The fact that the night sky is dark means that those assumptions are wrong or there are some unknown factors at work, such as the universe is expanding or it had a finite beginning (not infinite in size).

In 1922, Alexander Friedmann combined CCP with General Relativity and predicted that the universe cannot be static. His prediction was ignored by the world (including Einstein) but was confirmed seven years later in 1929 by Edwin Hubble.

Since the universe is expanding, then it must have a finite beginning. In 1948, George Gamow put forward the idea of the Big Bang theory, and the Olbers' paradox was put to rest. The expansion of the universe will dim the light (through red-shift) by a factor of about 2. The finite size of universe (that is, the universe is still young) gives darkness to the night sky.

Although in a small scale (such as the size of a galaxy or a cluster of galaxies) the mass distribution is not very uniform; the universe does seem to be roughly the same in every direction, provided one views it on a large scale compared to the distance between clusters of galaxies.

Not only CCP survived, but it predicts that there shall be a primordial microwave background when CCP is combined with the Big Bang theory. When the background temperature of the universe was above 6000 degrees Kelvin, the photons couldn't travel very far before being absorbed, and photons and mater tied together in the cycle of emission and reabsorption. This is called coupling era which lasted until 300,000 years after the Big Bang.

When the temperature of the universe dropped below six thousand degrees, the decoupling took place, and photons were finally able to shine freely. The photons that escaped at the time of decoupling, and which has been shining more or less unimpeded since then, shall be still here with us now. After 15 billion years since the decoupling, those primordial photons ought to be cooled to about 3 degree Kelvin (2.7 to be exact) and to have shifted its wavelength into the microwave region according to the calculation of the Big Bang theory. This microwave background was accidentally discovered by two radio engineers (not physicists) in 1965, and they were awarded the Nobel Prize for physics in 1978.

The discovery of this microwave background on the one hand reaffirms the validity of CCP, on the other hand gives rise to the large-scale structure problem. After almost three decades of measurement, this microwave background is too smooth (being isotropic and homogeneous to an accuracy of at least one part in ten thousand) to be able to give rise to a cosmos like the one we know of. Since there is indeed a hierarchy of structure of galaxies, there must be some fluctuation in the microwave background.

In short, there is a seemingly irreconcilable difficulty between the smoothness of microwave background and the actual large scale structures of the universe. This is the large scale structure problem. This situation was getting even worse in late 1980s. In a deep sky survey, many giant void (bubbles) and the Great Wall (a sheet of galaxies five hundred million light years long, two hundred million wide and about fifteen million thick) were discovered.

Although the Copernican Cosmological Principle allows some anisotropy in a small scale (in the size of cluster of galaxies), these newly discovered giant bubbles and the Great Wall are much bigger than the traditional CCP allows. In short, the validity of CCP is again in question.

In 1989, the COBE (COsmic Background Explorer) satellite was sent into orbit around Earth to probe deeper than ever before into the microwave background. In 1992, the COBE team reported that they have seen God -- the fluctuation (about seventeen millionths of a degree Kelvin) during the inflation which was before the Big Bang.

All these theories (CDM, HDM- Hot Dark Matter), discoveries (giant bubbles, the Great Wall, the microwave background), the principle (CCP) and the claim (seeing God) boil down to a single issue -- the initial condition before or at the inflationary bang. What is the initial condition at and before the creation.

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III: Initial Condition

On the one hand, the inflationary scenario seemingly provided an answer. It solves the horizon problem because the observed universe moved out of each other's horizon from this huge inflation. The flatness problem vanishes because the huge expansion blows the universe up so much that it appears flat. The large structure problem is also solved because the sudden expansion would have locked in quantum fluctuations that could have seeded the formation of large-scale structures.

On the other hand, this inflationary scenario gives rise to some new questions. Why would such a moment of inflation happen? What happened before inflation? In short, the inflationary scenario does not really solve the question of initial condition but only pushes it further back in time.

For the name sake, the initial condition has at least two attributes. One, it cannot be the result of any known physics process (including the Big Bang) because it is the condition at or before the Big Bang. That is, it must be a self-existent and a self-referencing entity. Two, it cannot be annihilated by any process, such as the inflationary bang or a converging system which rapidly lose memory of their initial condition or a diverging system which is ultimately chaotic. That is, it must still exist even today in some forms.

Since the microwave background is the finger print of the initial condition, the microwave background cannot be influenced by any process (such as galaxies formation) in any scale (the size of galaxy, cluster or supercluster). The degree of fluctuation must have been just about the same for all scales -- tiny, large or extralarge. This is in fact the finding of COBE. The mathematical expression of this microwave background is described as HZP (Harrisons - Zel'dovich - Peeble) spectrum. The COBE data matches HXP spectrum very well. Both of them hug along the line of zero. In fact, the areas above and under the zero line can very much cancel each other out. That is, the net fluctuation is zero although the local fluctuation gave rise to the large structure of the universe. Thus, we can very confident to state a initial condition hypothesis as follow: The initial condition at or before Big Bang is that the net quantum fluctuation is ZERO.

In order to maintain this initial condition, any localized positive fluctuation (which gave rise to galaxies) must be canceled out by a negative fluctuations (which gave rise to gravity), and this is the real-ghost creation process.

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IV: Cycling Universes

The modern cosmology is based on Friedmann's model and Hubble's discovery. Friedmann's model is based on CCP and General Relativity. General Relativity was intended to be a gravity theory which was supposed to describe an attractive force. Then, for heaven's sake why shall the universe expand? There are only four type forces in nature. Two of them (strong and gravity) are attractive forces. Electromagnetic and weak forces can be either attractive or repulsive. The weak force operates in an extremely short distance. It did influence the structure of the early universe. Today, it still makes contribution on many cosmic processes, such as the supernova, but it seems not to be the force to expand the universe. The electromagnetic force is a long range force, but most of large objects are electrically neutral. Although the momenta of photons randomly impact the objects in the universe, the photon momenta cannot be accounted to cause the expansion of the universe.

In the whole world, only Einstein and Alan Guth felt the need to introduce a kind of antigravity force. Einstein came up with a cosmological constant, but it turned out to be equal to zero exactly, that is, there is no cosmological constant. Guth came up the idea of false vacuum which acted as an antigravity only during the inflationary period which was before the Big Bang. Why shall the universe continue to expand even today after Guth's antigravity force (the false vacuum) vanished 15 billion years ago. What is the antigravity force now? Any cosmology model without including an antigravity force is doomed to failure because Hubble's discovery is a fact in nature.

The expansion of the universe is described by Hubble's law: Galaxies recede from the Milky Way at speeds proportional to their distances. So, all galaxies seem to fly away from Milky Way. If those galaxies are flying, they are powered by something. But, what kind of motor do those galaxies run on -- General Motor, Ford motor or a Datsun? This is not a joke. On the other hand, those galaxies can be viewed as stationary, but the space between them is expanding. Their recessional velocity is only the illusion caused by the expanding space. With a uniform expanding rate, the Hubble's law remains valid -- twice as far away looks twice as fast.

Why shall and how can space expand? The space expansion is the essence of this new physics, described with Equation Zero. The bouncing between real and ghost time creates 64 subspaces. A quarter of these 64 subspaces are true space, pure vacuum. Three quarter of these 64 subspaces are particles, baryonic matter. So, when time is bouncing forward, the space is expanded, and matter is created. In short, the Big Bang is not an isolated single event in the long ago history of our universe but is only a beginning of a continuous process.

Although in essence the CDM (Cold Dark Matter model) is a science fiction, it cannot be completely wrong because its description of universe is quite close to the real world. Although the omega does not have to equal to one (1) and there is no need for those fictitious cold dark matter (such as squarks, photinos, etc.), there ought to have some nonbaryonic cold dark matter. What are those nonbaryonic cold dark matter in this new physics? They are the unborn baryonic matter.

The essence of this new physics is that the universe not only is interacting with the past (such as the primordial fluctuation, the primordial neutrinos, supernova remnants, etc.) but with the future (the unborn baryonic matter). That is what life is all about. The universe is a conscious life. I will discuss this in a much better details in a future TOE issue The Conscious Universe.

As I have shown before, the gravity is the ghost partner of those created space and matter. Gravity acts as the banker on the one hand lends out energy for new spacetime, on the other hand it charges interest for the repayment. Thus, matter and anti-matter alternately appear in each Big Bang, and the size of the universe will increase by a factor 2 during each cycle. See Figure 1. These oscillating universes keep energy conservation law valid while new spacetime and matter are created constantly, and also give meanings to anti-matter.

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V: Conclusion