Chapter 1: Big Bang

Why is there a universe? Why is there matter? And why is there energy? Why are there the hardness of flint and of steel, and the beauty of planets, stars and galaxies? Why do they exist? How have they arisen? What have scientists found out about this?

Harald Fritzsch is Professor of Physics at the University of Munich. He writes about the theory of the big bang and its different stages: "The starting-point for the primary explosion, which we want to introduce now as Point Zero in our time scale and where, according to the extrapolations of the physicists, was an immensely huge temperature. It is not clear yet, how matter will behave at temperatures of more than 10³³ degrees, since at those energy densities our normal ideas about space and time will break down. Well, one can easily estimate that in the time between the primary explosion and the 10^-43 seconds after that, the temperature of the universe must have been higher than 10³³ degrees." (1983:265).

The mystery of the first 10^-43 seconds. "The early primary universe is actually a rather simple thing, whose state is mainly characterized by a single parameter: by the data of its temperature. If one knows the temperature, one can calculate, which types of particles are playing in the universe a role, how often these particles will occur, and so forth." (1983:266).

1^st epoch: the mysterious first 10^-43 seconds. "From the big bang to 10^-43 seconds after the big bang, the temperature was larger than 10³² degrees. Details about this first era are unknown."

2^nd epoch: 10^-43 seconds till 10^-33 seconds. "This epoch begins after the first 10^-43 seconds. At the beginning of this epoch, the temperature is about 10^-32 degrees. The universe is filled with a ‘primary soup’ of all possible sorts of particles: also quarks, electrons, neutrinos, photons, gluons, X-particles. The temperature of the universe then began to decrease fast. After 10^-33 seconds, the temperature sinks below 10^-28 degrees. The X-particles decay and leave behind them in the highly energetic plasma more quarks than antiquarks. The quarks that are left over are forming the primary matter. From them, later one, the galaxies, stars and planets will be made."

"We emphasize that this ‘surplus’ of quarks is very small. At the end of the 2^nd epoch, the universe consists of a very hot plasma, containing quarks, antiquarks, photons, and other particles. There were then about as many quarks or antiquarks as there were photons. That is why the number of the ‘surplus’ quarks is very small, compared with the number of all the quarks or antiquarks, about the order of magnitude of 10^-9. For one billion quarks or antiquarks each, there is only one ‘surplus’ quark. This ‘surplus’ of quarks, which the X-particles have left behind, does not play at first any role at all." - Fritzsch, H. (1983:267, 268).

At Planck-Time or at Time Zero?

The big bang is supposed to explain, how our universe arose some 15 to 20 billion years ago in a huge explosion. - When? - There are two different opinions: The one group of physicists says: The big bang occurred at the Planck-time, when the universe was 10^-43 seconds old. It had then a Planck-length of 4∙10^-35 meter, a Planck-temperature of 3∙10^-32 Kelvin, and Planck-energy of 5∙10⁹ Joule, and a Planck-mass of 5∙10^-8 kilogram. From this one Planck-particle, they say, our whole universe has then arisen. - And what was before the big bang? - They say: It is useless to ask: What was before the big bang?, because there is no "before"! For the time and space of the universe have only then arisen. Before the time of 10^-43 seconds (towards time zero), all our physical laws are breaking down. A black hole arises then, a singularity, a chaos. And in this black hole, all information is destroyed. At the singularity, the numerical values are all going to the infinite!

Physicists of the other group, however say: The world has arisen in the big bang. That is true. But not at the Planck-time, when the universe was 10^-43 old, but already before that: at time zero, at the singularity. At this time zero, the time, space, and energy of our universe have arisen.

Frank Tipler is Professor of Mathematics and Physics at the Tulane University in New Orleans, Louisiana, USA. He writes about the Planck-time: "Often one sees in the literature assertions that ‘the most likely radius of the universe according to quantum mechanics is the Planck-length’. Such assertions are not true. They arise from attempting to impose classical concepts on the quantum world; the only length scale that can appear in quantum gravity is the Planck length, so it is inferred that the radius corresponding to the peak of the wave function is the Planck length." (1986:212).

Professor F. Tipler clearly distinguishes in his books between the "time 0", calling it the "singularity", and the Planck time, where the universe was 10^-43 second old. The universe begins at "time 0", and not at the Planck-time of 10^-43 second. (1990:82, 123), Table 41.

Also Michael Berry, Professor of Physics at the University of Bristol, England, clearly distinguishes in his "history of world matter" between the Planck-time of 10^-43 second, which he calls the "quantum chaos", and the "time zero in seconds". (1990:182) Table 4.

Herwig Schopper is Professor of Physics and a former Director-General of CERN, near Geneva, Switzerland. He reports: "Lately, a speculation of the English physicist Stephen W. Hawking has caused some turbulence in public opinion. In his theory, he investigates the cosmic period, still lying before the inflationary expansion, and ending about 10^-43 second after the beginning of time. Also here, the universe must be treated as a quantum-system, since its size was at those times one billion one billion times smaller than an atomic nucleus. ... Hot big bang, cold inflation, and bubble universe: all of these theories do permit a universe with a beginning and an end, but also a world, which will be able to exist forever." - Schopper, H. (1989:391)

Is it true?

Has the big bang theory now been proved scientifically? Is it true? - Not all do agree with it. - Jonathan J. Halliwell is a postdoctoral associate at the Center of Theoretical Physics at the Massachusetts Institute of Technology. And he was a student of Stephen W. Hawking. He writes in Scientific American, December 1991, page 28, about the theories, dealing with the origin of the world:

"The conventional ideas are incomplete. They fail to explain or even describe the ultimate origin of the universe. ... The hot big bang model makes definite predictions about the universe as it exists now. It predicts the formation of nuclei, the relative abundance of certain elements and the existence and exact temperature of the microwave background - the glow of radiation left over from the initial explosion, which permeates the universe. ... Despite its successes, the hot big bang model leaves many features of the universe unexplained.

"For example, the universe today includes a vast number of regions that in the hot big bang model could never have been in causal contact at any stage in their entire history. These regions are moving away from each other at such a rate that any information, even traveling at the speed of light, could not cover the distance between them. This ‘horizon problem’ makes it difficult to account for the striking uniformity of the cosmic background radiation." - Halliwell, J. J. (1991:28).

"Then there is the ‘flatness problem.’ The hot big bang model indicates the universe to become more curved as time passes. But observations reveal that the spatial geometry of the universe we can observe is extremely flat. The universe could exhibit such flatness only if it started out almost exactly flat - to within one part in 10⁶⁰. Many cosmologists consider such fine-tuning deeply unnatural. Perhaps most significant, the hot big bang model does not adequately explain the origin of large-scale structures, such as galaxies. ... But the fundamental origin of these fluctuations remained completely unknown. They had to be assumed as initial conditions. In brief, therefore, the hot big bang model suffered from extreme dependence on initial conditions. Finding the present universe in this model would be as unlikely as finding a pencil balanced on its point after an earthquake." - Halliwell, J. J. (1991:28, 29).

The Universe: no Coincidence

Has the universe arisen through chance, through some lucky coincidence? Or has an intelligent Being designed it? What have scientists found out about this?

Horst Hiller, a German physicist, has done calculations in astrophysics. He writes in his book, Die Evolution des Universums (The Evolution of the Universe) (1989:145) under the heading, "The improbable universe": "The physicists asked: Why does the universe possess just those characteristics, that have been observed and measured by us, and why just these ones? The physical laws and a few - about a dozen - basic physical constants - lay down these characteristics. That is, solid, given values, that are contained in the physical laws. Newton’s law of gravitation, for instance, says something about the mutual attractive force between two bodies. The strength of this force is determined by the gravitational constant; it is one of those physical basic constants. Its numerical value has been measured, but cannot be explained. It is just accepted. Actually, the gravitational constant reveals a sort of ignorance. We do not know, why this constant is so and not otherwise. And this means also, that we do not know, why the gravitational force is just so and so strong and not stronger or weaker."

"To this set of physical values belongs also the speed of light. We cannot explain, why it is just 299,800 km/s, and why it is not less or more. The same applies to the masses of the nuclear particles, the proton and neutron, the mass of the electron and its electric charge, the Hubble’s constant and the matter-density of the universe. The last two values, though, are not always constant, but depend on the age of the universe." - Hiller, W. (1989:145).

"Sharp-witted thinking is showing us now, that those physical basic values are not only determining the characteristics of the universe, but that the universe owes its existence at first to the fact, that these values are just so and not otherwise. There is a very delicate balance. When one of these values is changed mentally, there will be serious results for the universe and with that, also for life and for mankind. One could change, of course, also certain natural laws, but then it would be much more difficult, to think through and to follow up on all the results for the physical world.

"If the strong force, working within the atomic nucleus, and that is holding here the nuclear particles proton and neutron together, were only a little weaker, there could be no hydrogen in the universe. Atoms with several nuclear particles would not be stable; the somewhat weaker force would not be able then, to keep the atom together. But out of hydrogen alone, we could hardly have arisen.

"If the force were only a little stronger, it would be easier to build up helium from hydrogen. Already in the glowing oven of the primeval explosion, a perfect nuclear fusion would have occurred. No hydrogen, but only helium and heavier elements, the universe would have contained then after this original fireworks. How could the stars have arisen then, that are living from the fusion of hydrogen and helium? The strong force, thus, lies within the narrow limits of just such a strength, that this universe was able to arise and to evolve." - Hiller, H. (1989:146).

What about the electromagnetic force?

Horst Hiller: "The electromagnetic force is binding the electrons to the atomic nucleus. If this force were weaker, than it actually is, the electrons could not be held at the nucleus, and there would be no chemistry. If this force were stronger, the electrons would fall into the nucleus. And also then, chemical reactions and the existence of life were impossible.

"But also the weak force reacts seriously towards changes. An imagined reaction prevents the fusing of hydrogen into helium. And the stars would have no energy-source. If the weak force increased during the big bang, all matter would fuse into helium." (1989:146).

"Our universe is therefore a rather improbable event, in view of the countless possible numerical values of the physical fundamental constants. Changing them always leads to a completely different universe, so that at least the development of life would be impossible. It seems that the physical fundamental constants are not arbitrary, but that they have been finely tuned, guaranteeing the evolution of life. It seems, as if life were only possible within this real cosmos." - Hiller, H. (1989:147).

Expanding Universe

How fast is the universe expanding? And how fast should it expand?

Horst Hiller: "The universe should expand with just such a speed, that space contains no curvature... The speed of expansion must be very close to the critical speed, or, and that means the same, the mass-density must lie near the critical density. Had the speed of expansion of the expanding universe, one second after point zero, been only a millionth part smaller, the expansion would have stopped again already 30 million years later, due to the mass-attraction. The universe would have collapsed into itself.

"Had the speed been much larger, though, matter, while expanding, would have thinned out so quickly, that it could not have condensed into stars and galaxies. At the known strength of the gravitational force, the universe, thus, expanded with the greatest accuracy at just such a speed, that the galaxies were able to arise. Galaxies and stars are the basic requirement for planets and for life. Within their atomic oven, the stars are also building up the heavy elements. When such a star then explodes at the end of his life, these elements can be used again to build up new stars and planets. Heavy elements are also needed for the development and existence of life, beside many other basic requirements." - Hiller, H. (1989:150).

Coincidence or Design?

Why is the universe there? Why does it exist? - Through a lucky coincidence or through design?

Horst Hiller: "The characteristics of the world, thus, do not seem to be coincidental. It appears to us, that nature is arranged in such a way, that there can be life and human beings. This astonishing fine tuning of the physical basic constants and the conditions at the beginning of the universe, caused Collins and Hawking as the first ones to conclude: ‘The universe is, as it is, because we are’."

"The question about the Creator is raised already by the big bang itself. For until now, we cannot explain, why this important event happened. Now we must also add the astounding latest scientific finding that this universe has been made in just such a way, that we ourselves can be there. The question about the Originator of this finely tuned system, existing above space and above time, should be asked."

"This world is ruled by a complete physicality. Without such a conviction it would make no sense, to search for a United Field Theory. In this theory, all natural laws and basic values are connected. There are certainly connections between the four basic forces and the constants of nature. The electromagnetic, the weak and the strong force, one was able to explain already as the expression of a single force. Only the gravitational force is still missing. But the physicists do hope of being able at some far-away day, to reduce all of the four basic values to one theory into a single force." - Hiller, H. (1989:150-153).

How precise

How precisely must the universe have started off at the beginning, when it began to expand? How precisely must its mass have been determined?

Horst Hiller: "Let us find out, what this would mean for the early state, right after point zero. Had the mass ratio been exactly 1, this value would have been maintained then, while the cosmos was expanding. And we would exist then in an open Euclidean cosmos. Variations of the mass ratio do show us a rather astounding result. The mass ratio can only lie now in the reported region of 0,1 to 2, if the variation from the critical mass ratio, one second after the cosmos was born, was differing so little from 1, that it was allowed to change only after the 15^th position after the comma, that is:

1.000,000,000,000,005.

It just seems unbelievable, that this value was able to adjust itself so precisely. Why does the density-ratio not lie near 100 or near 0,01?" (1989:157).

Big Bang Computer Simulation

What does one need, to make a universe: its particles, atoms, molecules, solar systems and galaxies? What must one know and be able to do, to make our universe? Which physical laws and fundamental constants must one apply then? What must one know and be able to do, if one only simulates the beginning in a computer?

The American physicist Heinz R. Pagels says about this in his book, The Search for the Beginning of Time (1985:239): "Let us imagine that we have a supercomputer that has programmed into it all the laws of physics as we know them today. The program contains the standard model of quarks, leptons and gluons along with some input numbers obtained from experiments, like the masses of the quarks and leptons and the interaction strengths of the gluons. Using these data, the supercomputer can calculate the properties of the hadronic particles, determine how they scatter from each other and then build a model of nuclei and atoms." (1985:239).

"The supercomputer has also programmed into it Einstein’s equations. It deduces that there are three homogeneous and isotropic spaces that could describe the whole universe - the FRW cosmologies. But we have to tell the computer which of these three FRW cosmologies applies to our universe. For definiteness we will tell it that the cosmic parameter omega = 1/10 corresponds to the open FRW cosmology. If the total matter density is a bit smaller or larger than this value, our supercomputer informs us that the computations on the early universe are not dramatically altered.

"Finally, the supercomputer has programmed into it the laws of statistical mechanics and thermodynamics. We tell the computer that for very early times in the history of the universe it can treat the universe as a homogenous gas of quantum particles governed by the laws of statistical mechanics. This is an immense simplification that results in a huge saving of computer time. The computer determines that such a gas is in approximate equilibrium and so, to compute all it needs to know, is the temperature of the gas, the specific entropy of the various quantum particles, the conservation laws for the interactions of the quantum particles and their masses. We give it these input data and it is ready to go." - Pagels, H. R. (1985:238, 239).

"In short, our supercomputer simulates the universe much in the same way that computers used by astrophysicists simulated the evolution of stars. Like Galileo’s telescope in an earlier age, computers, because of their capacity to manage complex information, open a new window on reality. They show us a picture of a world, we would otherwise never see.

"While the supercomputer is used in giving us a quantitative model of the universe, it is also useful for us to have a simple visual picture of mind, to help us interpret its output, especially for the big-bang period. The big bang should not be visualized as an explosion that originates at a point in space and expands outward. A better way of visualizing the big bang is to imagine that the space of the universe is closed and is just the two-dimensional surface of a sphere. On the surface of that sphere is the homogenous gas of quantum particles at a definite temperature, which interacts according to the laws of statistical mechanics. The expansion or contraction of the universe is visualized as the expanding or contracting of the sphere. As the sphere contracts in time the gas on its surface gets hotter, and if it expands it gets cooler." - Pagels, H. R. (1985:239).

What happens then?

Heinz R. Pagels: "Now we run the supercomputer and it calculates the properties of the universe, as it evolves in time. We can examine its output, displayed on screens and graphs, at our leisure, and see in detail what is going on. One thing we notice right away is that its most interesting output is for very early times measured in minutes, seconds and microseconds. That is because for these very early times the temperature of the gas of photons has risen sufficiently for it to react significantly with matter. After those initial hot early times, for billions of years to the present day, not much goes on from the viewpoint of microscopic quantum-particle physics. During these latter times the all-important macroscopic structures - galaxies, stars, planets and life - are made out of the primordial gas."

"Examining the very early universe, we learn that the basic parameter that governs the physical processes is the temperature of the gas of interacting quantum particles that fills the whole space of the universe. Temperature, because of its proportional to the average energy of the colliding particles, establishes which new quantum particles can be created from the energy of the collisions. For particles of a certain mass to be created out of pure energy, a minimum threshold energy is required.

"Such energy thresholds are observed in high-energy-accelerator experiments for which a minimum energy is needed in order to produce new particles. These specific energy or temperature thresholds can be computed from the known mass-energy of the quantum particles observed in the laboratory. Since the temperature of the universe increases as we go backwards in time, the existence of these temperature thresholds for particle creation implies that the early universe can be viewed as a series of stages or eras, each separated from the last by such a threshold." - Pagels, H. R. (1985:240).

What do you mean by this "threshold"?

Heinz R. Pagels: "For example, consider the threshold that occurs at the beginning of the ‘lepton era,’ when the universe is only about one second old and the temperature about 10¹⁰ K. (Here, and in what follows, all the temperatures and times will be approximate.) Below this temperature the universe consists of mostly a radiant gas of photons. But as the universe heats above this temperature, something new happens.

"The colliding photons become so energetic that pairs of photons collide and convert themselves into massive electron-positron (anti-electron) pairs. We know precisely the temperature at which this process first takes place because we know the minimum energy of a photon that accomplishes this transformation (which is proportional to the photon temperature) is just equal to the mass of the electron, a known quantity, times the speed of light squared - the Einstein E = mc² equation is used. Of course, the electrons and positrons will annihilate back into photons almost as soon as they are made, but they hang around long enough to influence the dynamics of the gas."

"This picture of particle-antiparticle production will be a basic theme of the big bang story as the temperature further increases, beyond the threshold of the lepton era at 10¹⁰ K. At even higher temperatures, muon-antimuon pairs are produced by the photons. The universe as it heats up becomes filled with every kind of quantum particle and its antiparticle - a scene of vast carnage and creation. There are several important features of this picture that we must bear in mind.

"First, the quantum particles, while each has a characteristic rest mass, may be treated as if it were massless - just like the photons - once the temperature of the universe is significantly greater than the mass-energy. The reason one may make this useful approximation is that the particles are moving so rapidly at high temperatures that almost all their energy is in their kinetic energy of motion and not their rest mass-energy. Effectively, material particles become like radiation - massless, and moving at the speed of light." - Pagels, H. R. (1985:242).

"Second, the new particles, once created, share the total available big-bang energy with the photons. For example, once the temperature threshold for the production of electrons and positrons is crossed, the universe consists of approximately equal numbers of photons, electrons and positrons, each having about the same energy. This equipartion of the numbers of different particles and their energy is a consequence of the universe’s being in equilibrium as it expands - the rate of particle collisions is greater than the expansion rate of the universe. Then the available energy can be spread out evenly to each class of particles that participates in the interactions. For example, if we imagine that for a split second photons outnumbered electrons and positrons, then more electrons and positrons would be created until a balance, or equilibrium, was achieved. ...

"Using the laws of statistical mechanics (with the appropriate modifications to take into account the different quantum statistics for the integer- and half-integer-spin particles) one can determine precisely the number of particles per unit volume for each of the various quantum particles in equilibrium at any time during the big bang. The power of statistical mechanics is that we can determine such numbers solely from the fact that the particles are in equilibrium - the details of the complicated interactions need not concern us. ... The importance of the exact conversation laws, like the charge conservation, lepton-number conservation and baryon-number conservation laws, which I previously discussed, also become apparent." - Pagels, H. R. 1985: 242, 243