Creation of the Universe Part I.

©Fernando Caracena 2013

The Big Bang Paradox

The amazing thing about physics is that it can be used to speculate intelligently about the origin of the universe, when mass, time and space were coming into being, and perhaps before the the laws of physics came to be as we know them now. How could that be? Physics begins by defining mass, time and space as the basic modes of physical perception, from which are defined the fundamental units of measure of physics; and yet, these modes of perception came into being just after the first spark of creation as everything unfolded during the process called the Big Bang. The basic modes of perception used to anchor ideas in physics did not exist initially. Other important units of measure, such as for energy, momentum and angular momentum are defined as composites of these fundamental units. Modern theories of physics combine these various concepts into still more complex composites. For example, Einstein's General Theory of Relativity relates the geometry of space-time to the distribution of energy and momentum. So what is it about physics and the universe that allows physicists to speculate about what happened in the universe during extremely small fractions of a second after the moment of creation before our fundamental modes of perception came into being?

Notice that I have used the term "speculate" rather than "analyse" or "theorise" above, because as yet there is no unified theory of Relativity (General and Special) and Quantum Mechanics, which two theories are the two legs on which modern physical thought stands. In cosmology, the two theories are applied to what happened after the first spark that set off the Big Bang.

At the moment of creation, none of the modes of perception that we consider fundamental were even possible. Time, space and mass emerged in the early universe from transitions of the state of everything as it cooled from a very hot dense, undifferentiated state. We are talking about time scales on the order of 10^-32 seconds, before it became possible to tell time in the conventional sense. How is it possible to talk of times scales when time itself did not exist? In a sense time had no meaning then. It has meaning only from our current perspective looking back about 13.8 billion years to the early moments of creation. Further, position and distance had no meaning at the beginning since they are defined only in terms of our own present standards by things that did not then exist.

Fig. 1 Cosmic Inflation From Wikimedia Commons under the Creative Commons Attribution-Share Alike 3.0 Unported license. Its use here does not imply any endorsement of this essay by the originators of this graphic image.

From a Newtonian physics perspective it seems only logical to assume that our fundamental modes of sensation are the correct choices of fundamental quantities. Newtonian physics has matter (represented by mass and volume) moving in the framework of space in time. But now we know that mass and space-time are properties emerging from a deeper, yet unknown reality and are not fundamental at all (see a previous blog on Emergent Properties and Physics). The current perspective from Quantum theory and Relativity allows us to discuss the early moments of the universe in some way rendered meaningful by standards that were rendered possible by emergent properties of the universe.

But why are contemporary physicists (especially high energy particle physicists) interested in what went on during the Big Bang? The answer is simple. During the earliest moments of the Big Bang, the state of its proto-substance was in such a a hot dense state that when particles did emerge, they were banging together with energy far in excess of what is now available in the most advance particle accelerators. Because of a cosmic inflation far exceeding the speed of light, their quantum effects were spread out and fossilized over a vast area of space, which furnishes a basis for estimates of their physical properties. In other words, the very small-scale quantum effects currently not available to high energy physicists are writ large on a comic scale, which high energy particle physicists can now profitably read in the heavens.

Fundamental Forces

Today physicists explain the structure and organization of the various scales and structures of the universe in terms of four fundamental forces: the strong nuclear force, which holds the protons and neutrons of the nucleus (nucleons) together under the strong repulsion of like, electric charges; the weak nuclear force that explains some rare but very important nuclear decays; the electromagnetic force that holds together and accounts for the stability and structure of the atom; and the force of gravity that holds galaxies and solar systems together. At the moment of creation, there was no structure nor mass, space and time to identify any point of reference in space, nor anything to be seen as an object subjected to forces. The four "fundamental forces" did not exist as separate phenomena; neither did mass exist. Any estimates of sizes and time intervals are based on contemporary units extrapolated backward from the present to the first moments of creation, when these units did not, nor could not, exist.

The cosmology of the Big Bang is based on two principles: the  the universality of the laws of physics and the approximate homogeneous and isotropic structure of the universe, for which there is good evidence on an intermediate scale of many galaxies. The idea of physical universality is basically violated by the idea of a moment of creation in the Big Bang, when there was no continuity in the existence of all things.  The assumption of a homogeneous and isotropic universe basically rules out weird solutions to the Einstein field equations such as the one proposed by Kurt Gödel for a rotating universe, which predicts the possibility of time-travel.

The Big Bang Senario

Extremely short-time events followed the first spark of creation [see the above Fig. 1]. What was it that caused the emergence of everything? What was that first spark? We actually do not know.Physicists think that it may have been something like a quantum fluctuation, subject to Heisenberg' s Uncertainty Principle, which was stated in a previous blog on The Old Quantum Theory: [OQT]

ΔE Δt ≥ h.                                                                              (9a)

Already, this assumes something about the nature of physical reality i. e., something containing quantum fluctuations pre existed all that we can now subject to measurement. Such assumptions are dangerous in that they can lead to an infinite regress into the unknown, but they are useful as a gambit to get the whole physics of the event amenable to analysis.

The closest philosophical concept to the equation OQT.9a that I can find from the premodern physics days is in the work of Emanuel Swedenborg's Principia, where he develops his ideas about how God created the material universe as the ultimate base for all creation. To quote from a synopsis of the work published by the Swedenborg Scientific Association:

"In Volume One, which he called The Principia, according to the habit of eighteenth-century philosophers, he presented his primary cosmological conclusions. He based his explanations of the 'Principles of Natural Things', on experience, geometry, and reason and postulated the creation of a 'first natural point' of matter. This first natural point, caused by divine impulse to action, consisted of pure motion. From this point of pure motion a series of finites descended, each series larger and somewhat less active than the preceding finite. Swedenborg's cosmology thus teems with energy from beginning to end. He argued that activity permeated all three natural kingdoms, animal, vegetable, and mineral. Any material substance emanated energy spheres which interacted with surrounding matter. His studies of magnetism, crystallography, phosphorescence, and metallurgy contributed to his belief in an active universe."

The initial singularity, which resulted in the Big Bang is as close as physics can define a point in space, which is the Planck length, which is

l_p=1.616199(97)x10^-35 m.

There is also a shortest time interval that we can physically define within our current physical context called the Planck time,

t_p=5.39206(32)x10^-43 sec.

In Swedenborg's philosophy The Divine is pure energetic love that has all the capability of bringing forth the whole of creation. When atheists ask the question, "If God exists, where is he. He must manifest himself if he really exists." The answer to that question was given by St. Paul, who said, "In God we move and have our being." So to the atheists, Swedenborg would point to the visible universe and its wonders and say, "You cannot see God directly. He is infinite. But, all this is the partial manifestation of God written in finite forms, for the rest, search the Holy Scriptures." Christians of course see God a manifested in the person of Jesus Christ.

Anyway, here we are focusing on the science, and for the purpose of discussion, we set aside theological and philosophical discussion.

The Cosmological Constant and Cosmic Inflation

Einstein felt that the universe should be static, otherwise, how could it last for eternity. When he set up the equations for The General Theory of Relativity, he found that the solution for a spherically symmetric universe always implied a change, either collapse or expansion. Einstein found that he could get a static solution for his field equation under those conditions by adding an additional terms to his theory that involved a constant called a cosmological constant. When Hubble presented astronomical evidence that the universe is indeed expanding, Einstein concluded that he had made a huge blunder in assuming a cosmological constant, which he called the biggest blunder of his life. It turns out in retrospect that Einstein was wrong in assuming that he had blundered. Fortunately, his cosmological term was included in his publication.

Pressure represents a positive energy density, which in General Relativity theory gravitates. In the later stages of stellar collapse, the very pressure that keeps the star inflated, contributes to the gravitation that causes its further collapse. The cosmological term however, does not correspond to a pressure, but rather to something more like a tension, which is like a negative pressure.

It turns out that space is filled with a dark energy, that dwarfs all other forms of energy. Many physicists feel that dark energy may be related to the zero point energies that are present in "empty" space, although there is some controversy over this, as some physicists feel that empty space should contain nothing at all, whereas zero point energy is something. I think that the origin of dark energy and of its companion dark matter are still areas of forefront research. For example, here is a research paper on the subject. Some physicists who are not very well informed about current research, may even call it a hoax, especially when debunking "perpetual motion" machines, the inventors of which claim that their machines extract energy out of the zero point energy of space. Anyway, zero point energy does conform to the correct behavior of the equation of state that would generate negative pressure under expansion.

Whatever it is, dark energy, which is portrayed by the cosmological term in Einstein's field equations, has the properties to drive a rapid expansion of the universe.

I am not an expert in General Relativity, nor cosmology, although I watch with interest Susskind's lectures on the subject from Stanford University. I have also read several books on the subject of cosmic inflation described in laymen's terms. Although I do not have expertise in using the mathematical tools, I can see how they operate, and if my life were long enough, I would devote a few years to studying them, along with learning to use symbolic math software that is available online to solve abstruse mathematical problems by way of the computer. Two books of interest to the lay persons on the subject are the following:

1) Weinberg, Steven, 1993 2nd edition: "The First Three Minutes". Basic Books, Perseus Book Group, New York, N. Y. 203 pp.

2) Guth, Alan H., 1997: "The Inflationary Universe". Basic Books, Perseus Book Group, New York, N. Y.358 pp.

Note, the second reference listed above, is a more modern treatment by a physicist who contributed to the current theory of cosmic inflation.

End of Part I.