PART I. THE ECOLOGY OF THE UNIVERSE
This part consists of four chapters that deal with the creation of the earth. The part stresses the ecological theme that if it were not for the peculiar ecological position of the earth there never would have been any life. Indeed, all forms of life can be seen as variations of ways in which living organisms capture the energy of the sun. The theme of the chemical basis of life is also stressed in that the origin of the universe is described in terms of physics and chemistry.
Chapter one deals with the origin of the universe itself. It describes the nature of the atom, which is the basis for the science of chemistry. The first chapter also describes the significant degree of randomness within the atom itself. Rather than talking about chaos in the world, this randomness can be perfectly handled by the science of statistics. Chapter two describes how statistics applies to all the liberal arts disciplines. Chapter three explains the elementary basics of chemistry. This chapter is absolutely necessary, for any discussion of the origin of life has to include a discussion of chemistry. Chapter four deals with the origin of our galaxy, solar system, and earth. The fortunate ecological position of the earth makes possible the existence of life. In turn, the structure of the earth itself sets the ecological context in which life developed.
CHAPTER 1. ORIGIN OF THE UNIVERSE
A major theme of the book is that chemistry and chemical evolution are the basis for all life. This first chapter deals with the physics of this chemistry, for it deals with the origin of chemical units, that is, the atomic elements.
This chapter covers the basics of atomic physics necessary for understanding statistics and chemistry, which in turn forms the building blocks of life itself, for not only is life itself chemical, but man's thought processes are also chemical. This does not mean, however, that life is just chemical, because thought becomes self-conscious and thus frees itself from chemistry. While thought is more than simple chemistry, it has to be understood within a chemical context.
The question of origins is an important one. Man has traditionally described human origins in religious or moralistic terms of a higher being or a higher purpose. However, the evidence now clearly indicates that the origins of the universe and our solar system and earth are explainable by natural laws.
This chapter discusses the field of cosmology, that is, the study of the origin and development of the universe. Before this can be done, however, a short review of some basic terms in nuclear physics is necessary to make the subsequent theoretical discussions easier to follow.
The reason for discussing the nature of the atom is that we need to understand the physical basis for chemistry, that is, the basis of life itself. The simplest model of the atom consists of a negatively charged electron swirling around a positively charged nucleus. This simple nucleus is composed of a positively charged proton and neutrally charged neutron. The opposite electrical forces between the positively charged proton and the negatively charged electron attract each other, thus keeping the atom together. This electromagnetic force just offsets the centrifugal force of the revolving electron.
More complicated models of atoms involve those that have a greater mass (i.e., the total amount of material in the atom). These models include additional electrons, protons, and neutrons.
Two Basic Categories of Elementary Particles: Hadrons and Leptons
There are two basic categories of elementary particles in the universe: hadrons and leptons. Hadrons, which make up the protons and neutrons, are made of sub-subatomic particles known as quarks. In addition to the quarks, scientists have found about two hundred "new" subatomic particles. In fact, so many new particles have been discovered that the physicists have come up with the expression the "particle zoo" to describe the many subatomic components.
Leptons are not made of quarks. Leptons are the class of subatomic particles found outside the nucleus that constitute three kinds of electrons -- the familiar electron, the heavier muon, and the recently discovered, much heavier tau. Associated with each kind of electron is a neutrino, providing a total of six leptons.
Four Basic Forces
Now that the atom has been defined, the basic forces affecting the atom and its constituent particles can be discussed. There are four basic forces in the universe. The strong nuclear force cements the nucleus of an atom together by holding the protons and neutrons to each other. Electromagnetism keeps the electrons in place around the nucleus, making ordinary matter seem solid. The weak nuclear force holds the various types of electrons together. The overall dominating force is gravity, which controls the biggest objects in the universe.
Quantum mechanics is the study of the elementary particles and three of the nuclear forces (excluding the fourth force, gravity). The name quantum comes from quantum theory that states that radiation is not emitted continuously, but in small, separate units; each unit being called a quantum. For instance, all light is made of quantum units known as photons. Light usually behaves like a wave, but it comes in specific-sized bits, like particles. Thus, light is both a wave and a particle.
A traditional stumbling block for physics has been the difficulty of bridging the gap between quantum mechanics and gravity theory. Einstein developed gravity theory and always dreamed of finding a unified field theory that could account for all four nuclear forces. The theories that hope to lead to the ultimate grand unity of all the forces are called grand unified theories (GUTs). Recently, there have been some promising attempts to bring quantum mechanics and gravity theory together (see superstring theory below).
Most of the theories about the origin of the universe are derived mathematically. This is just one illustration of the importance of mathematics for understanding the nature of the universe and the world around us. Math is also very important for the social sciences and increasingly so for the humanities. Math is the basis for the science of statistics and this science has been extremely necessary for the progress of the social sciences. So, even though, the treatment in this book is a non-mathematical one, this is merely for ease of understanding rather than a reflection of the way science is conducted.
THE ORIGIN OF THE UNIVERSE
Now that the basic terms have been introduced, a discussion of the origin of the universe can proceed. It must be clearly stated, however, that science cannot provide answers to such issues as the existence of God and the nature of the soul. Many books have been written about prominent physicists, such as Stephen Hawking, who talk about knowing the mind of God. The existence of God, however, cannot be proved or disproved by physics or physicists. These subject matters are beyond science. Despite this word of caution, if religion makes concrete statements about the nature of the observable world, science can check these statements to see if they are accurate or not.
Possible Origins of the Universe -- Time Zero
The big bang theory is currently accepted as the dominant theory of the origin of the universe. However, because of problems with uniting quantum and gravitational theories, this theory says very little about the actual origins of the universe. The theory has an explanation for the big bang that occurred very shortly after the start of the universe, but does not explain why the big bang occurred. Therefore, additional theories have to be applied before discussing the big band.
Something from Nothing
Marcia Bartusiak (1986) in her book Thursday's Universe explains some of the ideas about the universe at time zero (around fifteen billion years ago). Some nuclear physicists have been working on the idea that the universe arose out of nothingness. One such theory (that does not violate the basic law of conservation that matter or energy cannot be either created or destroyed) is that of physicist Edward Tryon. In his version of a zero-energy universe, the known universe may be balanced by an unknown universe of negative gravitational potential energy located somewhere in our cosmos. The existence of a balancing universe would make the total energy of the universe equal to zero, the positive energy being balanced by the negative energy. Since this calculation does not upset the total sum of energy in the two spheres, it would have been possible for the known universe to have appeared out of nothingness.
Nothingness is a state without space or time as we know it. The Russian émigré physicist Alexander Vilenkin also theorizes that the universe appeared out of nothingness. Support for this theory comes from the spontaneous creations that have actually been measured in physics laboratories (Bartusiak 1986:259). Lasting no more than a billionth of a trillionth of a second, physicists have seen electrons and their antimatter emerge out of nothingness and just as quickly vanish.
Before the origin of our universe there existed only an ultramicroscopic froth of space-time bubbles. One can imagine this as a cauldron roiling with tiny closed universes. These would start to grow, then collapse upon themselves, and disappear back into nothingness. But, there was always a small chance that one of the bubbles, instead of collapsing, would explode outward releasing its latent energy. This explosion could have given birth not only to the universe, but also to time itself. The actual shape of the universe is a hypersphere. This type of structure has no edge or boundary. Theoretically, an astronaut starting from one point would return to the same starting point, if the astronaut kept the space vehicle always pointed in the same direction.
Given the thesis of roiling bubbles, our known universe may only be one of a whole family of sister universes. After all, present telescopes can only see out to a distance of twelve billion light-years. However, the true boundaries of the space- time domain may be 100 billion billion times more distant.
Physicist Alan Guth theorizes that the universe began with a brief moment of superaccelerated expansion. At 10 to the minus 35 power of the first second into the birth of the known universe, an unimaginably hot bubble began to expand or "inflate."
The inflationary universe is identical to the big bang universe for the time after 10 to the minus 30 power of the first second. Prior to that time, there was a brief period of extraordinarily rapid expansion during which the scale of the universe increased by a factor of 10 to the 50 power times more than was suggested by standard big bang models.
For every piece of matter, there is a piece of antimatter. Normally, one would expect these to cancel each other out. How did our universe survive this? One answer is that at 10 to the minus 35 power of the first second, there was cooling to such a degree that the fluctuating mixture of particles and antiparticles froze into place. For every 10 billion or so bits of matter and antimatter that settled out of the teeming cosmic soup, one extra particle of matter arose. In other words, there were roughly, 10,000,000,001 specks of matter for every 10,000,000,000 bits of antimatter. Within a millionth of a second, the quarks and antiquarks, leptons and antileptons, paired off and annihilated one another. Fortunately, that tiny surplus of quarks over the number of antiquarks remained to create our material universe.
As the universe expanded, it cooled. In fact, it became so supercooled that the pressure in this state reversed the effect of gravity. (Gravity actually became a repulsive force causing space to balloon outward at a superaccelerated rate.) The universe doubled until it became the size of a softball. This momentary inflationary epoch ended when the supercooled symmetry began to break spontaneously. Upon freezing, the inflationary universe converted all its latent energy into a cascade of extremely hot matter. This in turn led to the explosion known as the big bang. Gravity subsequently returned to being an attractive force.
The Big Bang
Physicists think that there was one unified force that existed at the instant of the big bang. At ten to the minus 35 power of the first second, gravity broke its bond with this single unified nuclear force. (Nobody knows for sure, since there is no quantum treatment of gravity.) Gravity ultimately became the weakest of the forces. For example, the gravitational force between an electron and a proton is 10,000 trillion trillion trillion times feebler than the electrical force binding the electron and proton together in an atom.
At about 10 to the minus 30 power of the first second, the big bang occurred. The explosion caused parts of the universe to move apart by stretching the space between the parts. The example usually given is one of a spotted balloon with dots representing parts of the universe. The balloon never goes into an external void but rather simply inflates. (Nothingness is not the equivalent of space. Nothingness is "no space.")
As the universe exploded, its pure energy began to condense into pointlike particles, such as quarks and leptons. The strong force then broke away from the one unified nuclear force to develop its own characteristics. At 10 to the minus 10 power of the first second, the universe had grown to about the size of our own solar system. At this time, the electromagnetic force separated from the weak nuclear force.
The universe was a seething soup of quarks. The quarks were too energized and too densely packed to form hadrons. Between 10 to the minus 6 power and 10 to the minus 4 power of the first second, the basic constituents of matter in the universe were created, as quarks combined in groups of three, forming neutrons and protons. At 10 to the minus one power of the first second, that is at about one hundredth of a second, the temperature of the universe was about 200 billion degrees Celsius. At three minutes past zero the universe started to cool enough so that protons and neutrons could join to form nuclei. Before this time any joining was prevented by collisions with photons from background radiation or with other particles.
The first nucleus created this way was that of heavy hydrogen. The strong force pulled a proton and two neutrons together to form the nucleus. At about the same time, nuclei of helium were being created out of a pair of protons and one or two neutrons. It was at this time that the 75:25 hydrogen-helium ratio that exists to this day in the universe became established. Nuclei of a few other light elements (i.e., those with few electrons and protons) were also formed.
When the earth was 500,000 years old (that is, 14.5 billion years ago), elementary particles joined together to form complete atoms. Before this, the universe was still too hot for an electron to fall into a quantum orbit around a nucleus. Weightier elements emerged from deep inside stars either from the gradual actions of stellar winds or catastrophically from the explosion of a supernova.
Superstring theory may prove to be the first quantum theory of gravity that does not violate basic physical laws. At the heart of superstring theory is its redefinition of the fundamental building blocks of nature. Such entities as quarks and leptons are not really pointlike particles, but rather one-dimensional strings that come in the form of closed loops. The nuclear forces and the particles of the universe depend on the manner in which these superstrings behave in a world composed of ten dimensions. Which of the various elementary particles a string represents depends on the manner in which it vibrates. A single string has the potential to turn into an infinite variety of particles, just as there are innumerable frequencies at which a guitar string can vibrate. (When the weak, strong, and electromagnetic forces were united in a single force, it is believed that quarks and leptons were virtually indistinguishable, quickly and easily changing from one form to the other.) Strings can join or divide -- two coming together to form one or one dividing into two. This interaction is the origin of the fundamental force responsible for gravity, electromagnetism, and the two nuclear forces. Superstrings could thus be the long-sought key to the unifying theory of the universe.
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