011911
Part 1: Cosmogony, Cosmic Evolution, Evolution of Earth Earth
.
Content of the essay “Cosmogony, Cosmic Evolution, Evolution of Earth”:
. Page
Introduction 1
.
1. Cosmogony, Cosmic Evolution: 2
1.1. Abstract Beginnings 2
1.2. First Surprises: Granulation: Strings, Subatomic Particles, Forces –
Diversification and Complexity arise. The miracle of existence 5
1.3. The Next Surprise: The Combinatorial Principle, Evolution Begins:
The Origin of Atoms and Molecules 8
1.4. Order or Chaos – Deterministic or Open-Ended? 9
1.5. The “Basic Principle of Evolution” 10
1.6 Collapsing Clouds: Quasars, Black Holes, Galaxies, Stars 11
1.7 Formation of the Heavy Elements 14
1.8. Supernovae, Heavy Dust, Pre-Organic Molecules: Foundation for the Next Step 15
1.9. The “Principle of Limits in Development and Branching Progress”:
The Origin of Planetary Systems, Our Own Solar System 16
1.10 Some Remaining Mysteries of the Originating Universe 19
2. The Origin and Evolution of Earth, the Moon, and the Atmosphere 19
2.1. The origin of our “Earth” 19
2.2. The origin of the Moon 20
2.3. The History of Earth 22
2.4. The Early Oceans, the Early Atmosphere, and Climate 24
2.5. Resilience in Great Catastrophes 27
2.6. Singularities in Earth’s Evolution 28
.
Introduction:
.
When we pause for a moment in our busy life – at lunch, during a holiday, on vacation – we can perceive the wonderful and sometimes cruel existence we live in – the universe, nature on this planet Earth, our surroundings, our body, our mind. In trying to understand this existence, we find that everything in our world is evolving – has always been evolving and will continue to do so. If we want to understand our existence, we should attempt to understand this evolution.
.
Not too many years ago, one of the early NASA space projects provided the very first and rather beautiful pictures of Earth as seen from outer space. Astronomic telescopes had already provided excellent pictures of distant galaxies. Now we could visualize how our own “Milky Way” galaxy would look with the tiny spot of our Sun as one of billions of others somewhere in its outer reaches – and a still smaller, blue planet, "Earth”, whirling around that tiny sun – about four billion times already since its appearance. That small Earth is our only home, but our brains that evolved only a few ten thousand years ago allow our minds to span the universe in time and space. What were the starting conditions, principles, laws, and forces of nature that let this evolution occur?
Recent progress in astronomy has taught us how our universe originated in one spot some 14 billion years ago and has been expanding in all directions ever since. What happened in time and space that, out of the original burst of energy at that time, finally we humans, with all our exceptional talents, came to exist and live on this tiny planet where we now are – and to develop the mental capabilities we now have?
.
A few key aspects of Creation and evolution appear to be fundamental to the understanding of what occurred. They are especially surprising and impressive [1].
Come along on a mental voyage – to explore the existence which we live in – from the vastness of the universe to submicroscopic molecular life, the virtual phenomena of the mind, and unfolding civilizations – from an origin in the distant past to an expected end in the distant future!
.
.
1. Cosmic Evolution:
.
1.1. Abstract Beginnings
.
What can be seen as the essence of “existence” in space and time? According to one perspective, “difference” is the essence of space, and “change” is the essence of time. Without difference in at least one parameter in at least one dimension – whether density, color, or anything else – there would be no definable space. And without change, there would be no definable time.
The scientific understanding of the ultimate origin of our universe is shrouded in abstract speculations, none verifiable by observation. The various scientific theories of origin mainly attempt to render unnecessary the religious or traditional “ex nihilo” (from or out of nothing) assumption of Creation and to present a precedent situation leading to the Big Bang in an understandable way, consistent with the observations and structure of the universe after the Big Bang.
There are various problems with this approach. The (possibly assumed) precedent situation only leads to another question of its beginning, thereby merely shifting the original question of origin to an earlier time. Otherwise, a perpetual, cyclic or ongoing sequence or multiple creative starts in the form of other universes originating out of a super-universe have to be assumed, stretching indefinitely into the past – thereby assuming time without a beginning.
This model still leaves us with the question of how the infinite cyclic or ongoing sequence of the super-universe – if it has not existed “forever” – was ever established. There are various theories of this genre. Earlier theories considered the effects of imaginary time or the spontaneous appearance of our universe through quantum mechanical effects [2]. Another theory [3] proposes a multitude of universes, as bubbles following each other, possibly several in parallel – like the “fractals” of chaos theory. A newer theory [4] is an outgrowth of “string” theory and posits the perpetual repetition of “branes” in multidimensional space touching each other as starting points of new universes every time one of them cools off in infinite dissipation.
The most commonly accepted theory at this time, one also derived from string theory and the recognition of “inflation”, visualizes a super-universe with an almost limitless variety of possible individual universes, all possibly quite different from each other (dimensionally, and in character) [5], totally unrelated to ours – thereby allowing no connection or exploration [6]. This theory still leaves the question of the specific origin of all those universes and their specific structure unanswered. More or corrected theories may be presented from time to time [7].
Most people, however, hold a basic transcendental belief [8] concerning the ultimate cause of creation of our universe, or of any other universe, or of a “multi-verse” – specifically in view of the finely tuned forces, natural laws, and basic constants that let our universe appear as a highly intellectual composition. This belief assumes a transcendental force or “formative essence of existence”, not simply a physical force, or a higher intelligence or a “spirit” as the ultimate base of existence. The assumption of a transcendental force, spirit, or essence is considered to be “religious”, while the other assumptions are considered “scientific” speculations of theoretical or mathematical physics. They both seem to meet at the same point.
There is actually little mental difference between the views of “religiously believing” and “scientifically assuming”. Both are based on mental assumptions that are provable only by their perceived effect in the universe – but both look at the same universe. Such observations often are, but should not be, arbitrarily selective – especially the religious ones. Otherwise, they can lead to a variety of contradictory theories, depending on the selectivity of their observation. All such theories can serve as the foundation for mental systems of thoughts and interpretations of the universe – only that the “transcendental” view allows an originating cause to be more than just a “physical” phenomenon, even more than just an “intellectual essence”, one possibly including the dimensions of emotions (love?), ethics, values, aesthetics, and other dimensions that are fundamental to our minds and cultures and that usually are not the key concern of the sciences in cosmogony.
It is a matter of the now very active discussion of “Science and Religion” to elucidate to what extent the factual observation of the universe justifies, or does not justify, a transcendental assumption concerning the origin of the universe [9].
It is quite a different matter to then also assume, or prove, any further “action” of such spiritual force of origin in the subsequent evolution of the universe (see Chapters 3.1.2 and 3.3), the possible “responsiveness” to personal prayer, and the divine “setting of moral standards” – unless one sees those moral standards as anchored in human nature and, thereby, in evolution – and, therefore, in the foundation of Creation and, by this roundabout way, in its possible transcendental essence [10].
Irrespective of all these considerations, the original energy bursting out of the Big Bang, still not structured into particles in its beginning, can be seen only as energy “fields” of very high power in a small space. Fields of energy are nothing material – yet, something real – existing in the emptiness of space – in the nothingness – in the vacuum. How can emptiness or nothingness – the vacuum of space – harbor fields? What are fields held by emptiness?
.
One cannot leave the discussion of the origin of our universe without marveling at another aspect of this universe: The originating universe exhibited the phenomenon of constantly flowing time (not slowing down, not accelerating, but always flowing at a constant rate in the vastness of the universe over the past 14 billion years – at least as far as is inferred from observations [11]). The fact (see Relativity Theory) that time flows at a constant rate for any one observer, but appears to flow at different rates for observers moving relative to each other (and possibly stops in “Black Holes”), renders this phenomenon all the more mysterious [12]. Additionally, there is the quantum-mechanical surprise that there is no smaller time increment than so-called “Planck” time. One can also marvel at the fact that the originating universe had three dimensions of space (not two, or four, or any other number [13]).
.
The fact that our universe is governed and constrained by forces, laws, and principles of nature –and, therefore, functions in an order that can be described by mathematics or theoretical physics – is another mystery of origin. It is specifically this “intellectual” character of the universe that can be seen as pointing to a transcendental origin, foundation, or “Formative Essence of Existence”.
.
Another “miracle” of Creation occurred within the first fraction of the first second of existence – a short inflationary period of the originating universe. At that early time, the energy ball that constituted the infant universe expanded from negligible size to approximately the size of a baseball. The expanding space itself mysteriously provided a very large amount of additional energy and the expansion speed was a multiple of the speed of light – while afterwards, the speed of light was found to be the highest speed that can possibly exist in nature.
There are new theories that take this inflationary period into account. Some scientists are inclined to think that such theories, properly representing the occurrences in nature, are expressions of the originating force. One must be somewhat careful with such a posteriori statements. For example, one cannot say that, since the new theories allowed the inflationary period to happen, it must have happened. If the occurrences had been found to be different, science would have found a mathematical presentation or theory to represent the universe accordingly. In other words, not the theories drive the world but what the world is found to actually be leads to suitable theories – theories that often change quite dramatically as new insights are gained concerning the workings of the universe [14].
.
.
1.2. First Surprises: Granulation: Strings, Subatomic Particles, Forces –
Diversification and Complexity arise. The miracle of existence
.
As the Big Bang occurred, the original energy – as it expanded in space and time – quickly assumed some structure – by partially “condensing” into a variety of subatomic particles [15].
There are several surprising, and very significant, aspects of this first phase of cosmic formation:
- The original energy of the Big Bang did not expand as one big wave – as, for example, the wave that forms and expands around a pebble that falls into a quiet pond. Instead, a large portion of the original energy broke down – granulated – into extremely small, discrete parts that filled the originating space.
- Not only one type, but a limited, diverse set of different strings or subatomic particles occurred – where “strings” can be visualized vaguely as short energy waves – like tiny multidimensional or circular energy waves concentrated in one point and oscillating at different frequencies.
.
Modern science can prove the necessity for the formation of subatomic particles and could even predict which new ones are yet to be found. But one should be careful with this view. As is said above, it is not the theory that forces nature to exist in a certain form. When nature is understood, theories become formulated that best describe its appearance. As new knowledge is gained, theories are changed until they fit. The miracle still lies in nature, not in the theories – unless one considers the fact that nature can be understood and described by certain mathematically formulated theories as a miracle in itself, as well as an indication of its intellectual character, some would say, its “spiritual” essence.
Scientific research has found three groups of subatomic particles, each with a certain variety of members:
- Quarks (or “hadrons”): Commonly, six different types are indicated. But it has been proposed that there are actually only four or five different types, all with unusual names (“up”, “down”, “strange”, “charm”, and “bottom”). Two of them make up most of the material universe. The other three have an unstable, short-lived existence.
- Leptons: Some members of this family are better known (“electrons”) than others (“muons” and “taus”), and all have associated “neutrino” particles.
- Bosons: These subunits of the universe serve to transmit forces. For example, the transmission of “W bosons” provides the action of the “electro-weak force”. The “gluons” function is the transmission of the “strong force” that can bind quarks together.
.
All together, there may be a couple of hundred different basic particles. More important is the fact that, for each type of particle, there exists a type of “anti-particle” with an equal amount but opposite kind of energy, such that a combination of the two would neutralize or annihilate both. The newly created universe appears to have produced an asymmetrical amount of those two types, allowing the existence of the world as we know it after most opposite particles annihilated themselves and only the not-matched ones were left over. The resulting “matter” makes up about 5% of our universe – half of this located in all the galaxies, the other half expected to be in some large intergalactic clouds of hot gas, as recently discovered. This figure may possibly have to be corrected upward by a large percentage (up to 18% has already been reported) if the mass and also the number of brown dwarfs and smaller stars, which already constitute possibly more than half of the mass in the galaxies, are both confirmed to be larger (possibly by a factor of two) than presently assumed.
Another large part (maybe 25%) of the original energy of the nascent universe condensed into “dark matter”, not visible and little understood so far, but possibly forming the bulk of all galaxies. Finally, there is the recently discovered “dark energy”, accounting for the largest part of our Universe, the remaining 70% of it, understood as part and expression of space in the universe and responsible for driving the galaxies apart at increasing speed. It is still a mystery how space can harbor forces and provide the gigantic energy for all the galaxies’ acceleration.
The figures for the dark matter and dark energy would have to be corrected downward if the percentage of normal matter is corrected upward.
A small remaining part of the original energy – the part that did not form discrete strings and subatomic particles or dark matter and dark energy – remained in the form of radiation – that ever since has moved around in the created space.
.
It is a special mystery of the origin of existence that the particles resulting from the original energy – the strings or subatomic particles – exhibited various types of forces that emanated out into space – namely the electromagnetic forces, gravity, and certain atomic forces, each very different from the other. Those forces became responsible for giving structure to the existence we live in. The atomic forces structure all matter by keeping the subatomic particles together in the atoms while also keeping different atoms apart. The electromagnetic force structures the protective field around Earth and provides us now with electric energy, light, and communication, including the internet. The gravitational force, small as it may be between atoms, is, in accumulation, the gigantic force in the universe that structures galaxies and solar systems.
No particle is fully independent in the universe.
.
All these forces emanated at a certain speed, the “speed of light”, through the empty space that separated those particles from each other. How can forces exist between particles that are themselves combinations of “strings”, of fields in space? Only a limited set of different forces occurred between particles. That specific set and no other forces determined the course of the world ever since.
In other words, all of existence – all energy, specifically also all matter, all radiation, and all forces in the universe – in other words, all phenomena that we perceive as constituting the reality of the universe (including us) – are merely fields in the vacuum – absolutely abstract phenomena of empty space. When we touch things, we merely sense the repulsive forces between approaching “strings” that constitute what we call “particles.” When we see things, we perceive only the electromagnetic radiation that was emitted, modified, or deflected by combinations of “strings”. That is all there is in existence – fields!
It is a mystery how empty space can host fields or forces, how these fields and forces can be propagated by the vacuum at a precisely given speed, and how they can form all there is in the universe – the celestial bodies, us, and our brains providing our minds.
.
Furthermore, some of the subatomic particles – though composed only of energy strings in the vacuum – exhibited the effect of “mass”. They require force for acceleration and show “momentum” as they move along. Mass can be understood as a form of concentrated energy and can be transformed back into radiation – as in Einstein’s law, e = mc2, where the dissipated energy “e” is equal to the product of the mass being dissipated and the square of the speed of light. This is the same law as for the dynamic energy of a moving object, being the product of their mass and the square of their velocity – as when something hits you. It is a mystery how an accumulation of strings or subatomic particles – energy waves or field accumulations in the vacuum of space – can have “mass” with inertia.
Was it inherent in the original energy of the Big Bang that this structure of particles and forces had to occur, or is there a two-aspect creativity – two different concepts of Creation – of energy and of structure – of power and of controlling laws – that resulted in the structure of the universe – miraculously understandable to us (in part) by the mathematics of theoretical physics?
.
The fact that several different types of particles and forces appeared out of the original burst of energy is the first demonstration of nature’s principle of diversification – and increasing complexity – later to be found throughout ongoing evolution. It is bewildering how many types of subatomic particles appeared and how complex their interaction is. Some few particles may account for the majority of what we perceive as the material universe, but all types of particles are needed and all types play their role to form the universe we know.
.
As if the above view of the originating universe – with all its field effects in the vacuum, its multitude of particles, and its various forces – were not mysterious enough, one must additionally consider the findings of quantum mechanics or quantum physics.
- Max Planck found in 1900 that not only all matter, but also all energy is “granulated” into discrete quantities of energy of multiples of a basic “action quant” – as confirmed in 1905 by Einstein. Planck also found the duality of light as existing both as wave and as particle – later expanded to other subatomic particles by Schrödinger.
- Pauli, in 1924, discovered the “exclusion principle” – whereby no two sets of quantum numbers defining the energy state of the particles in an atom, molecule, or “fermion-accumulation” can be alike.
- Uhlenbeck and Goudsmit brought the discovery of “spin” in electrons in 1925.
- In 1927, Heisenberg presented his “uncertainty principle”, indicating the probabilistic nature of all particles in the dimensions of space and momentum. Ultimately, this led to the recognition that some particles and their anti-particles may appear spontaneously in space in a probabilistic distribution – and annihilate themselves again.
- Later, some scientists were led to the assumption that the origin of our universe could have been a quantum-mechanical event.
- Hawking arrived at the conclusion that “Black Holes”, the ultimate form of celestial bodies in the dying universe, can become dissipated over long periods of time – through asymmetric absorption of such spontaneously generated particle pairs on the black hole’s surfaces – leaving nothing but dispersing radiation in an ever-expanding space.
- This insight of uncertainty or indeterminism – together with chaos theory, whereby even the smallest variation may cause the greatest consequences – resulted in a breach of the Laplacian determinism as a basic understanding of the universe. (The deterministic character of the wave aspect of particles remains but within a probabilistic distribution for the particle represented by the wave).
.
In sum, there were the following creative aspects of the origin of existence that one must see as having appeared together:
- The appearance of energy
- The spreading of the original energy in appearing space and time
- The granulation of energy into “strings” and subatomic particles
- The appearance of forces that provided for structures
- The appearance of natural laws (and principles and constants) that provided for the dynamic evolution of the universe in time
- The combinatorial principle allowing for the emergence of new and ever higher dimension of existence out of composing particles of whatever kind
.
What a strange world this universe is that we now inhabit!
.
.
1.3. The Next Surprise: The Combinatorial Principle, Evolution Begins:
The Origin of Atoms and Molecules
.
As the originating universe cooled due to its expansion, the “subatomic particles” began to combine, thereby forming a variety of larger “atomic particles” – mainly neutrons (without an electric charge), protons (with a positive electric charge and consisting of three quarks), electrons (much smaller particles, with a negative electric charge, consisting of leptons), and the particles that form the little-understood, so-called “dark matter” of the universe.
Some of these “atomic particles”, in turn, combined to form a variety of “atoms”, the building blocks of the many chemical elements, resulting in 105 types [16] or “elements” of increasing atomic size in total. These “elements” became the building blocks of the universe.
Finally, some of the atoms combined to form the first miniature “molecules”. The accumulation of these molecules later formed the various materials in this world – from air, water, and minerals to all the organic substances.
In each step, the forces between the smaller particles determined the structure of the newly emerging larger particles.
.
These three steps – the appearance of the different types of atomic particles out of the combination of subatomic particles, then the emergence of atoms, and finally the emergence of molecules out of atoms – are the first demonstration of nature’s “combinatorial principle”. This principle indicates that nature allows for the combination of smaller building blocks into larger ones which then assume totally new characteristics – new dimensions of existence – that were not observable with the smaller building blocks [17].
A pile of toy marbles remains just a pile of toy marbles. But if a pile of neutrons, protons, and electrons had always stayed a pile of neutrons, protons, and electrons and had not formed atoms – or a pile of atoms had always stayed just a pile of atoms and had not formed molecules – the world we know could not have developed.
For example, the atoms constituting the elements hydrogen, calcium, and gold are something descriptively altogether different from neutrons, protons, and electrons of which all of them are combined – just in different configurations. The descriptive nature of molecular water (combined out of 2 atoms of hydrogen and 1 atom of oxygen), salt (combined out of 1 atom of hydrogen and 1 atom of chloride), and sugar (a combination of 6 atoms of carbon, 6 atoms of hydrogen, and 6 atoms of oxygen or a multiple thereof, depending on the type of sugar) are different in their principal characteristics from the elemental atoms of which they are composed. .
This becomes even more apparent when considering the very large and complex organic molecules that make up the living organisms composed mainly only of atoms of carbon, oxygen, hydrogen, nitrogen, phosphorus, and sulfur – plus some trace elements.
This phenomenon of the combinatorial principle can be compared to the use of bricks to build a cathedral or electronic components to build a computer – the combination of letters to form words and of words to form sentences – or the combination of basic elements of knowledge and perception to arrive at new concepts or systems of thought.
.
The three phenomena of Creation, the granulation of the original energy of Creation providing the first building blocks and the forces acting between them, plus the combinatorial principle that allows their ongoing combination to ever larger and different units of existence, are the foundation of the phenomenon of evolution that brought us the world we now inhabit.
.
.
1.4. Order or Chaos – Deterministic or Open-Ended?
.
It is important to note that the expanding universe – in its distribution of energy, radiation, and particles within the expanding space – showed, for reasons unknown, a large degree of randomness in density distribution.
A three-dimensional model of the universe at our time would look like a sponge – with certain bubble-like spaces containing almost no stars, galaxies, or dust clouds – and other spaces containing “filaments” and knots of accumulations of matter in the form of stars, galaxies, or dust clouds – all in a random arrangement like a sponge.
In other words, the essence of the expanding universe demonstrated a duality of strictly following the laws and principles of nature, while also containing large areas of randomness – a duality of order and freedom.
.
This duality can be observed much closer in our sphere of life. The stars in the sky appear in a random distribution – though in their movements strictly following the order prevailing within the galaxies in the universe. The surface of an ocean, seen from a great altitude, appears smooth and following the round shape of the surface of Earth. From up close, the ocean is covered with a random distribution of waves. An approaching snow storm may appear as a cloud with a given shape, but within it, the distribution of snowflakes is totally random – each having a well-defined geometric shape as given by the laws of crystallography.
Thus it appears as if spheres of strict order in accordance with the laws of nature are superimposed on, or alternating with spheres of randomness or freedom within the structure of the universe.
This duality of order and randomness not only allowed the evolution of a large variety of structures, but also made future development of structures not-deterministic, unpredictable in detail, and, at best, probabilistic.
.
Equally important for all later development is the duality between normal physics and quantum mechanics resulting in the duality between deterministic predictability of large-scale events and probabilistic, non-deterministic phenomena on the atomic level leading to unexpected developments.
In other words, development does follow the laws and principles of nature – but also includes the indicated background randomness of the universe and the uncertainty of quantum mechanics. Chaos Theory shows how minute differences in detail can result in major changes of the overall system.
.
.
1.5. The “Basic Principle of Evolution”
.
The probabilistic variations and random events in the universe result in an evolutionary thrust in evolution [18]. Actually, there are the following elements to be found in an evolutionary step:
- The starting conditions define the character of a potential step in evolution
- The boundary conditions may limit the evolution; but, more importantly, they may indicate new options for viable evolution
- Probabilistic variations allow a gradually different relation to the boundary or environmental situation and, thereby – if viable – may offer a step in evolution
- Random events may allow for radically new approaches in evolution
.
With probabilistic variations and random events occurring at all times, there is an ongoing thrust for further evolution – occurring as starting conditions and opportunities permit.
This will be discussed in greater detail in the chapter on the natural evolution of life, where this “Basic Principle of Evolution” becomes most significant and best observable, as high propagation rates and limited resources or adversity augment the evolutionary pressure in the sphere of life.
The sum of this principle and all observations indicates that:
- The universe is not developing in accordance with a plan and converging on a goal
- Instead, the universe evolves in steps as possible at any one time or place in accordance with the then and there given starting and boundary conditions – with evolution being driven by probabilistic or random variations, and finding viability in accordance with opportunity and qualification.
.
Therefore, all evolution – in each of its steps – is not end-point conditioned or goal-attracted, but is starting-point conditioned (for each step) and forward-directed. Thereby, evolution remains open-ended within the limits of opportunity [19]. This will be discussed in more detail in connection with the progress of natural evolution.
.
.
1.6 Collapsing Clouds: Quasars, Black Holes, Galaxies, Stars
.
As the nascent universe formed enormous clouds of particles, some important inherent instability became apparent. A diversity of phenomena resulted from that.
The original atoms or molecules in the so-called gaseous “dust clouds” were attracted to each other by gravity, weak as those forces were for each atom alone over large distances. The high temperature of those clouds – indicating the high speed of the individual particles – did not allow the dust in those clouds to coalesce or “accrue”. But the gaseous dust clouds cooled by means of radiation (natural emanation of radiation), and, in the areas of highest concentration of those clouds, the probabilistic motion of the particles could lead to probabilistic accumulations. Such accumulations – after some cooling – had, finally, higher gravitational attraction than the heat-related dispersion.
Once a nucleus of many particles had been formed, their accumulated gravitational force increased and ever larger amounts of particles were attracted. Thus, an avalanche of large accretions of matter could form, as permitted by cooling. Such gravitational collapse of gaseous dust clouds could take diverse courses. The most notable ones were the formation of quasars, Black Holes, and galaxies.
.
Quasars:
Their characteristics are:
- Relatively small size of these celestial objects (only about one light-year in diameter, while galaxy diameters are in the hundreds of thousands of light-years)
- Enormous luminosity (about 1,000 times the luminosity of a large galaxy)
- Mostly formed in the first 2 billion years of the universe
- Explained as the formative processes of Black Holes
- Their radiation resulted from the gases falling as an avalanche at high speed into the respectively forming new black holes
.
Black Holes:
The “stellar” black holes are understood as resulting from the avalanche-like collapse of dense clouds of dust in a single point (small area) whereby, when large enough, such enormous pressures are created at the center of the collapse that the phenomenon of “Black Holes” was created, a gravitational concentration of such size that not even light could escape such a hole any longer.
To understand this phenomenon, one must consider that the nuclei of atoms have only one ten-thousandth the diameter of the whole atom – the diameter being defined by the sphere of electrons circling around the atom core and keeping other atoms at that distance. In other words, normal materials consist mostly of empty space separating the atomic nuclei from each other by means of their electron orbits. But when the external pressure exceeds a certain point, the electron spheres are crushed and the atomic nuclei are pushed directly together. This creates such an enormous material density with its associated gravity that no atomic particle can escape this core any longer. No longer can any quanta of light escape – resulting in the “black” appearance of these aggregations.
“Galactic” or “quasar” black holes form at less pressure or density, but with the same effect.
.
Galaxies:
A collapsing cloud of dust – at first a giant ball of dust with higher concentration at the center – ends up forming a disk. This results from any spurious rotational momentum in the part of the cloud that was collapsing. As when rotating ice skaters hold weights in outstretched hands and their rotation accelerates as they retract the hands with the weights, the collapsing clouds rotate faster as they collapse (in accordance with the natural law of “the conservation of angular momentum”). Actually, each attracted particle will rotate on a differently inclined plane around the center; but the intersecting planes will lead to collisions until all parts find themselves in the plane of the original cloud rotation – in a disk.
Further gravitational collapse of such a disk – after cooling due to the emission of radiation – can permit the formation of a small core – later to become a black hole when the pressure in the core and its mass is high enough. Some theories propose the opposite sequence, with the formation of a black hole first and subsequent attraction of galactic masses of gas around it.
For reasons that are not fully understood, the dust disk around many galaxies shows mostly two (estimated to be in more than 60% of galaxies), but sometimes three, spiral arms of accumulated star formation. In many large galaxies, the spiral arms bifurcate, resulting in 4 to 6 branches in the outer areas. This spiral pattern rotates around the galaxy’s core (at a different rotation rate from that of the stars). Occasionally, a large central ring and, more often, a central bar can be seen in the galaxies, sometimes rotating at a different speed, sometimes with arm protrusions from each of its ends (e.g., galaxy NGC 1087 in the constellation Cetus). One theory of galactic evolution assumes that avalanche effects in the collapsing proto-galactic dust discs form gigantic shock waves circulating around the center of the galaxy-to-be. Actually, the spiral arms of galaxies do not wrap up tightly – rather, they keep their pattern and look like rotating sprinklers, suggesting effects emanating from the rotating center, possibly having something to do with shock waves emanating from black holes at the centers of the galaxies [20]. The presently prevailing theory sees “resonances” in the stellar orbits as the cause for the spiral arm formation [21].
.
Galaxies come in a large variety of shapes (round and elliptical, flat or with a central bulge) or sizes. The smallest discovered so far is Andromeda IX with only 3,000 light-years diameter, at a distance of 2 million light-years from our sun (see www.SDSS.org). Other small ones have already merged or are in the process of merging with our galaxy, the Milky Way [22].
.
Stars:
Those shock waves in the galactic disks are thought to cause new accretions in the galactic dust clouds, but on a smaller scale. The resulting smaller dust disks also form concentrated centers. Those are the ones that become stars when their mass, inner pressure and temperature allow thermonuclear reactions to set in. Therefore, these newly formed centers that became stars light up, letting the luminous spiraling arms of the galaxies appear [23].
.
There are by now approximately 100 billion stars in our galaxy, the Milky Way, with more still forming while there is interstellar dust left over [24].
The largest stars are the brightest and have the shortest period of light emission – only in the 100-million-year range – and end in an explosion as supernovae. There are about 10,000 supernovae per million years in our galaxy. That translates into 500,000 supernova explosions per spiraling arm per revolution of that arm at the distance of Earth from the center of the galaxy.
The supernova explosions past the edge of the star-forming spiral arms circulating the core of galaxies may contribute to the propagation of these as shock waves, like a cosmic ram-jet.
The smaller stars, like our Sun [25] – with a light-emitting life of about 10 billion years – leave the shock waves or arms of the galaxies, thereby also leaving the area of the most intense and destructive radiation resulting from the supernova explosions. This fact is important in the evolution of life on planets of such stars. Our Sun with its planets is assumed to rotate once every 220 million years around the center of our galaxy, the Milky Way.
On a clear night, one can see a multitude of stars and galaxies. A good telescope allows seeing a still greater quantity. Actually, however, the universe is mostly empty space. If one were to build a model of the universe in which the Sun had a diameter of only 2 inches (5 cm), Earth would be about 15 feet (5 meters) distant from it and would have a diameter of less than 1/64th of an inch (0.5 mm).
Correspondingly small and widely distributed would be the other planets in empty space. The next solar system to ours would be at a distance of more than 500 miles (750 km). In between, there would be nothing but empty space, even where we are, right within the disk of a galaxy, in our Milky Way.
Between the distributed galaxies there is, again, nothing but expansive empty space. The galaxies are distributed in the universe much like the material in a sponge. There are accumulations of galaxies in some clusters, as well as a multitude of ribbons of galaxies on the periphery of gigantic bubbles of almost empty space.
This exotic structure is in slow motion in consequence of the ongoing expansion of the universe, gravitational forces, and other causes for the motion of galaxies, occasionally leading to their collision. Our Milky Way is expected to collide with the galaxy called the Andromeda Nebula in some billions of years [26] as it may have collided already with some smaller galaxies in the past (that may have provided the star belt around the Milky Way).
.
.
1.7 Formation of the Heavy Elements
.
After the Big Bang, the majority of the atoms formed in consequence of the above-explained “combinatorial principle”. They were of the smallest kind, mostly just hydrogen and some helium, composed of one or two neutrons, one or two protons and one or two electrons.
When sub-segments of galactic dust disks – the forerunners of galaxies or their later companion gas cloud – collapsed, as indicated above, they formed small cores, the future stars. These cores came in different sizes as they formed the stars-to-be. Consequently, the compression and heat in the centers of these developing stars varied according to their size. Within the medium-size stars, the pressure and heat were enough (at about 10 million degrees Kelvin or C) to weld several hydrogen atoms into larger helium atoms – the same transformation that occurs in atomic hydrogen bombs. The excess energy appeared as the bright radiation of such stars. This occurred to our Sun.
As this atomic transformation within our Sun continues, it becomes more intense. In another 2 to 3 billion years, shortly before all hydrogen is used up to form helium, the Sun will further heat up, as it has done in a minor way during all of its life – then rendering all life on Earth impossible. At the very end of the cycle, in 4 to 5 billion years, the Sun will have enlarged enormously, its gaseous edge reaching the path of Earth, while its glow will be reduced to a dark red. Then, as the heat is dissipated and no new heat is generated due to lack of hydrogen to be transformed into helium, this “Red Giant” begins to slowly contract..
This contraction will produce such pressure at the center of the then much smaller Sun that – combined with the heat from the contraction – a new atomic reaction will set in – forming mainly the elements of carbon and oxygen out of helium. What is left of such a sun is then a small star called a “White Dwarf” containing much carbon and oxygen – the destiny of possibly 95% of all stars.
.
The atomic burning (or construction) process of larger atoms, beyond carbon, works much faster in very large stars than in medium-size stars like our Sun, completing the life of such giant stars in only about 100 million years. In a sequence of steps, finally the relatively heavy element iron is formed, consuming almost all their atomic particles. When those larger stars collapse for the last time as supernovae at the end of the atomic process that burned all hydrogen and helium and finally formed iron, such enormous pressure and temperature occur at their center that free neutrons are formed, allowing the formation of all the remaining heavy atoms (or chemical elements) beyond iron – up to uranium, plutonium, and beyond. There is a limit, however. Larger atoms are not stable and fall apart as quickly as they are being built. This is the end of atomic evolution in astronomic or astrophysical terms. Later, in planetary development, nature forms molecules – accumulations of atoms that far exceed the size of the heaviest elements and open new approaches to evolutionary development.
.
.
1.8. Supernovae, Heavy Dust, Pre-Organic Molecules: Foundation for the Next Step
.
When the process of forming heavy atoms in the largest stars is completed and no further heat is generated from atomic processes, gravity prevails over the dissipating force of heat. At that point, the very large stars collapse in such a fury that their implosion appears like an explosion when most of the material around their core is driven away into outer space – distributing atoms of a large variety and, including great quantities of heavy elements, all over cosmic space. Such a supernova explosion takes place about once every hundred years in a galaxy like ours – that means 10,000 times in a million years.
Another aspect of such implosions/explosions of supernovae is the distribution of strong radiation into space. This radiation can lead to the formation of methane (a carbon atom linked to 4 hydrogen atoms) and many other types of proto-organic molecules out of the hydrogen, carbon, oxygen, and other elements contained in the great dust clouds in space.
Many of the heavy atoms being distributed by exploding supernovae are a bit overloaded with atomic particles, providing some instability and the need for minor corrections in atomic content. This appears as radioactivity when these atoms shed the extra particles or fall apart into two more stable parts. Such radioactivity provides additional radiation that further contributes to the formation of proto-organic molecules in space.
As will be shown, new gravitational collapses – in other areas of the galaxy, forming new stars and their planets at a later time – utilize these heavy materials resulting from supernovae in their dust disks to form heavy planets such as our Earth and possibly use the proto-organic molecules for the formation of life.
.
.
1.9. The “Principle of Limits in Development and Branching Progress”:
The Origin of Planetary Systems, Our Own Solar System
.
The formation of the heaviest possible (and still stable) elements in supernova-yielding stars of large mass may have appeared as the end of cosmic evolution. It seems to be a principle of evolution in the universe that all developments ultimately reach a limit when they lead to a size or complexity that results in instability – later also observable in natural, technical, or political evolution. But the surprising phenomenon of evolution in the universe consists of the fact that evolution then continues in a different dimension, on a different level, as on a new branch. At the point of development of the universe when supernovae reached the limit in producing heavy elements, this evolutionary branching occurred through the development of complexity in or on planetary systems – ultimately leading to life and the appearance of humans. .
As already described, collapsing segments of the dust disk of a galaxy formed smaller discs with stars as their massive centers. The prevalent turbulence or rotation within the galactic disk– that may have caused the galactic collapse in the first place – led to a rotation of the small dust discs forming the stars. As long as such a disk had low density and high temperature, further accretion of matter was delayed. But as such a disk cooled through dissipation of radiation and increased in density, a surprising phenomenon occurred. Different from the very large galactic discs that developed rotating “arms” or shock waves full of nascent stars, the much smaller discs around stars formed discrete bands. Those bands “accreted” (consolidated) over time, giving birth to planets.
There seems to be a specific regularity of such formation of bands and of planets out of each band – most likely dependent upon the density of the disk material and the temperature (compare the formation of snowflakes out of humid air as it cools – of rather uniform size at originally similar distances – depending on temperature and humidity). There is a balance of forces in a dust disk around a nascent star. The heat of the dust and the radiation pressure from the new star drive the gas and dust outward; gravity pulls it inward. In consequence, the heavy elements in the dust disc settle closer to the nascent star in the center, and the light elements remain farther out. But the many perturbations and collisions of the coalescing masses allow some of the lighter elements and water molecules to arrive at or remain in the inner bands, including that of our Earth.
The developing bands in the dust disk around a nascent sun split into narrower bands closer to the star and much wider bands farther out.
.
Ultimately, a planet develops in each band, accumulating much of the material within that band. This may be facilitated by the fact that all those particles within a band do not circulate in parallel but most often on elliptical paths around the star with innumerable intersections of their paths and consequent collisions. Their motion is further complicated by the fact that each collision that varies their forward motion also results in a change of their rate of rotation around their sun and, consequently, their distance from the sun. Faster-circulating particles will move farther out and rotate slower on those wider paths, while slower particles will drop closer in on the central star and begin to rotate faster on those narrower paths. This creates additional turbulence in each band, first facilitating the narrowing of the band and then accretion in the form of a planet [27].
Some recent discoveries indicate that planets formed around some new stars in the “short” time of only a few million years after the origin of their respective sun.
.
Our own solar system formed in the large area of the Milky Way galaxy where earlier supernova explosions had left enough dust containing heavy elements. As this dust disk of our nascent solar system cooled enough to accrete into bands and those into planets, the heavy dust had already had time to gravitationally sink down closer to the center of the whirl around our Sun. Furthermore, the temperature of the dust disk is greater in the vicinity of the central Sun due to its radiation and the greater friction at the higher speed of rotation of the closer particles. This allows only heavier materials to accrete, driving the lighter materials toward accretion farther out in the solar dust disk. Thereby, several planets consisting of heavy material were formed closer to the Sun, while the gaseous planets – usually accreting into larger bodies – were formed farther out in the disk.
The formation of bands, their distance from the Sun and their width, and the distance of the subsequent planets from the center of our solar system followed closely a mathematical sequence (the Titius-Bode sequence). One will have to discover more solar systems with planets like ours in outer space to fully understand the astrophysical background of this sequence – and the probability for the formation of other Earth-like planets in the universe, possibly in large numbers.
The accretion of planets out of bands in the dust disk around a central sun is a rather messy affair. From the time of the original formation of the dust disc, and due to its mode of formation, the dust particles rotate around the central sun on various planes that are just slightly inclined to each other. They also move not in perfect circles, but rather on slightly elliptic courses. This leads to collisions of dust particles and, first, accretions into small clumps. At the same time, some particles, in transferring their kinetic energy to another particle or clump without sticking, will lose their rotational movement around the sun and the consequent centrifugal force. They will fall in large numbers into the central sun. Other dust particles may be excessively accelerated by impact and may fly off, out of the still accreting band at any possible angle, contributing to space dust that will possibly impact any of the forming planets of the solar system at a later time until it is wiped out of the solar system by the “stellar wind” emanating from the turbulence of the central sun.
As such initial clumps of accretion get larger, they begin to exert an increasing gravitational force on their environment, attracting more dust to accrete around them. Larger accretions of material are called planetesimals. They, too, can collide with each other due to their different speeds and paths, possibly leading to further accretion into ever larger bodies, finally forming a planet. But some such collisions of planetesimals can be destructive, with some particles losing kinetic energy and falling into the central sun, others possibly being thrown out of the accretion band and becoming comets. In sum, only a limited part of the original dust bands ends up in the formation of planets, with much of the material having fallen into the Sun or having been thrown off course [28]. The final rate of rotation and ecliptic inclination of the planet’s rotation relative to its path around the Sun are also influenced by those accretionary collisions and later comet or asteroid encounters. Until more Earth-like planets are discovered in outer space and their rotation evaluated, we do not know how unusual or typical Earth’s rotation is – and, consequently, the foundation of its climate, as discussed below.
A special case is the beginning accretion of a planet out of a band of dust between Mars and Jupiter. This band rotates around the Sun at a slightly different rate from Jupiter due to the difference in distance from the sun. Consequently, Jupiter perpetually keeps sweeping over this band. Accretion clumps or planetesimals in this band are disturbed by the passing gravitational force of Jupiter. This leads to the break-up of the planetesimals before they become too large, leaving only a band of various chunks of material, called the Asteroid Belt. It also leads to additional collisions within the band with resulting ejections that become comets. Many of the comets reaching Earth in our days result from this Asteroid Belt and many more must be expected in the future [29].
Comets of planetesimal origin have played an important role in our solar system. In the very early solar system, some very large ones existed (the number is believed to have been more than 10), possibly as large as the planet Mercury or Mars now is. One of those, possibly out of the same band as Earth, is supposed to have hit Earth more than 4 billion years ago, leading to the formation of our Moon, as described in a later chapter. Others have hit Earth from time to time, leading to great devastation, as also described later on.
.
The band out of which Earth developed contained heavy elements, but very little carbon or water. Outer planets (Jupiter and beyond) evolved out of planetesimals containing these materials in great quantities. It is assumed that icy comets that originated in the accretion of those outer planets – or, in later time, were part of the Kuiper or Oort Belt (see prior footnote) – contributed the large amounts of water and carbon that was subsequently found on Earth.
Some icy comets, possibly from the formation of the outer planets, collected space dust on their surfaces through the long time of their existence in outer space. Some of that dust on their surfaces contained proto-organic molecules. These surfaces allowed further chemical changes of the proto-organic substances under the influence of radiation from the Sun and radioactive materials in space, leading to proto-organic materials of higher complexity and precursor materials of life, as also described later, possibly triggering life as they struck the Earth some 3.8 billion years ago [30].
A preceding chapter of this essay called attention to the fact that the universe contains spheres of clear order in strict adherence to the laws of nature (see, for example, the perfect rings around Saturn) superimposed to or combined with spheres of chaotic, random, or probabilistic disorder (note the random appearance of comets) leading to an unpredictable evolution of existence. The above described origin of planets, planetesimals, and comets – and their interaction – is another such example, in this case leading to the evolution of Earth and our evolution on it – possibly to other similar or different evolutions in outer space.
The observation of the first extra-solar planets around other stars in our galaxy in recent time, by means of the newest and most advanced telescopes, has shown a number of very large planets of those stars on mostly very elliptical orbits. They were found in connection with about 8% of all Sun-like stars that could be observed.
Some comments: Only very large planets can be detected with the present means of astronomy, and only those that travel in the plane of observation (not perpendicular to it). The elliptical orbit allows those planets to sweep a large area of their respective dust disk, consequently allowing them to become quite large. What causes this ellipticity is not clear at this time – but, possibly, it is the passing of celestial objects. It is not clear whether most areas around stars are thus disturbed, leading to such large planets on elliptical orbits – and whether our solar system, with its quiet formation of near-circular bands and of consequently smaller planets, is the exception – or, vice versa, the rule.
Furthermore, some of the detected planets are very close to their stars. One theory suspects a migration of such planets toward the center, closer to their stars. But one could also discuss the rate of rotation of the forming dust disk. If that was very low, planets should be found close to their star – and vice versa. The question arises, again, whether our planetary system was caused by fortuitous circumstances, in this case, with a favorable rate of rotation of the originating dust disk, or what the distribution of those rates of rotation in the universe are with what consequences for star formation. NASA’s “Kepler” telescope mission (a successor to Hubble) should bring further information sometime after 2007.
.
.
1.10 Some Remaining Mysteries of the Originating Universe
.
The expansion of the universe caused by the explosive Big Bang had been expected to slow down on account of the gravitational forces between all the components of the universe – the dust clouds, the black holes, and the galaxies. Much to the surprise of all scientists, it was found just recently that the universe expands at an accelerating rate. The common explanation is found in a repulsive energy emanating from space (“dark energy”), as during the inflationary period shortly after the Big Bang.
At this time, it is open to question whether such acceleration will permanently keep augmenting with the increase of space in the universe or whether there could be a reduction in repulsive energy and, ultimately, a reversal, leading to a new collapse of the universe.
.
The other remaining mystery of the universe is given by the fact that only a small amount of all the mass or matter constituting the universe is visible or detectable. The vast balance of all matter is called “dark matter” but has not yet been identified, fully located, or understood.
In sum, the content of the universe is now seen by some scientists as being only 5% in conventional matter (atoms, molecules), 25% (or more) in “dark matter, and possibly 70% in the still mysterious “dark energy” – unless substantial corrections come from the recently discovered larger weight of the numerous “brown dwarfs” and smaller stars. This indicates the magnitude of the challenge for science in trying to fully understand the universe – in addition to the question of unifying relativity theory based on gravity with quantum mechanics concerning the world of subatomic particles, electrons, and atoms.
.
.
2: The Origin and Evolution of Earth, the Moon, and the Atmosphere
.
2.1 The origin of our “Earth”
.
The band where our Earth was formed around the Sun contained much iron and other heavy materials as well. Most importantly, this band also contained enough carbon, oxygen, nitrogen, phosphorus, sulfur, calcium, silicon, and water that were so very important for its future development. This mix should not be considered overly exotic. The universe is old enough for many super-star collapses and supernovae to have occurred in our and many other galaxies, thereby seeding space in the universe, specifically within the “arms” of their respective galaxies and in between the arms, with all those heavy elements, as indicated earlier.
The specific composition and rate of rotation of the cloud of dust where our solar system was formed was favorable for the later development of life. Our resulting Sun had a size to allow a long period of sufficient energy production. A smaller size would have provided less energy, a larger size a shorter solar life. The rate of rotation allowed heavy planet formation at a suitable distance from the Sun. A higher rate of rotation of the disk would have resulted in planets at a greater distance with less solar energy availability. A slower rate of rotation would have formed no heavy planets or only closer to the Sun with excessive solar radiation.
The accreting and initially very hot Earth allowed the heaviest materials (iron, nickel, and others) to sink into its center. Some of the captured material was slightly radioactive, for the reasons indicated above, with very long decay times. This remaining inner radioactivity of Earth caused the its inner areas to continually be heated up, resulting in some inner convulsion, which led to a protective magnet field and, equally important, to plate tectonics, as described later. A balance between this core heating effect and the dissipation of the heat through the Earth’s surface and its atmosphere corresponds to the size of the Earth and its age – and could be typical of such planets in other parts of the universe.
Earth’s outermost layer was formed by the lightest among the heavy materials. It still contains large amounts of trapped, very light elements that can develop into gasses and escape into the atmosphere when driven out of their rocky enclosure, as through fractioning and heat or volcanic eruptions. The rocky outer layer of Earth has the characteristic of very poor heat conductivity, thereby keeping the inner mantle and core temperature under its cover more elevated.
.
.
2.2. The Origin of the Moon
.
There are various theories explaining how the moon was formed to circle around Earth.
The least likely theory indicates the capture of another celestial body by Earth. But the almost perfectly circular orbit and the similarity of material and age (about 4 billion years) indicate that the Moon either came out of Earth or out of the same band that formed Earth.
Since Earth rotates faster than the Moon spins around Earth, the tidal wave created by the Moon on Earth is always being pulled ahead of it, thereby accelerating the movement of the Moon. Consequently, in the course of time, the Moon assumes a path with a wider orbit around Earth and Earth is slowed down in its rotation. The Moon actually gains about 4 cm in altitude per year at this time. It would have gained more per year while it was closer to Earth where the tidal pull was stronger. Fossil records in ancient coral indicate that, 350 million years ago, the Earth rotated 400 times per year, compared to only 365 times now; 450 million years ago, it rotated even faster – 450 times per year – resulting in the length of a day being only 20 hours. Following this reasoning back in time, calculation would indicate that the moon “separated” from Earth only 2 billion years ago – if the oceans and their tidal waves were always similar to the present ones (but, actually, the oceans had different shapes at different locations on Earth in the past) and if the Moon actually ever did separate as one body and was not formed in a different way.
The rock of the moon indicates that it began to form about 4 billion years ago and had attained very high temperature when it was formed, possibly higher than the rock on Earth – as indicated by the loss of all material from the Moon that becomes volatile at or below such a certain elevated temperature (anything more volatile than potassium is missing from the Moon’s material).
The difference of time between the age of the rock (4 billion years) and the calculated beginning of Moon-lifting (2 billion years ago) has not been well explained so far! The proposed formation of the Moon through accretion out of a ring of debris should not have required 2 billion years. Furthermore, if the Moon had been lifted out of a low orbit of accretion at an early time, not only the tides, but also the tidal deformations of Earth’s crust would have been enormous, leading to significant heating. On the other hand, flowing water can be shown to have already existed on Earth 3.8 billion years ago – but possibly derived from the impact of an icy comet at that time.
The Moon does not revolve around Earth on the equatorial plane! The Moon’s plane of revolution is tilted relative to Earth’s rotation. This required some external influence or impact – unless one can assume that at first a debris ring formed around Earth, that the rotation axis of Earth then changed its direction (under the gravitational influence of the Sun) and was stabilized only as the solid Moon had accreted at a later time, that was then found to rotate around Earth at a somewhat inclined plane.
The most likely theory indicates that the Moon accreted (possibly less than 4 billion years ago) from a ring of debris (itself possibly 4 billion years old) circulating around Earth. But how did this debris originate, being basically of the same material as Earth? After all, two other planets also have rings of dust or debris and their origin is not very clear either – but their rings are in their equatorial plane – and our Moon revolves around Earth in a plane that is at an angle to Earth’s equator. Six of the nine solar planets have one or several moons – a total of 33..
Presently, there are various alternative theories to explain the origin of the original ring of debris around Earth that is thought to have accreted to form the Moon, none of them quite satisfactory:
Fission theory:
One theory indicates that the Moon split off from an irregularity of Earth. That would have required a certain “resonance” of Earth that could be expected if Earth rotates once every 2 hours. But the above calculation of “Moon-lifting” indicates that the highest rate of rotation of Earth would have been once every 5 or 6 hours at a time when the Moon was almost touching Earth, as calculated from the combined angular momentum of Earth and Moon [31]. At that slower rate of rotation, Earth would have had to be much bigger to reach resonance – and what mass remains between Earth and Moon is not enough for that – unless a large amount of material was thrown off at that time through vaporization (as indicated above) and subsequently disappeared. That would have been a very hot event – going somewhat with the very hot origin of the Moon’s rock. But the band where planet Earth formed around the Sun did not yield that much gaseous material for accretion. Also in this theory, the separated part of Earth would have broken up into small pieces, first forming a ring of debris, with subsequent, slow accretion.
The fission theory specifically is questioned by the fact that the Moon’s orbit around Earth is not on the equatorial plane – where it would have to be in case of having centrifugally moved out of Earth – unless one can assume, as already indicated above, that at first a debris ring formed around Earth, that the rotation axis of Earth then changed its direction (under the gravitational influence of the Sun) and was stabilized only as the solid Moon had accreted at a later time, that was then found to rotate around Earth at a somewhat inclined plane.
.
Another theory assumes the remote possibility that a close pass of another celestial body could have drawn the mass for the originating Moon out of Earth – then forming a ring of debris at an angle to Earth’s equator.
The parallel accretion theory:
In a simple model, the ring of debris would have formed at the same time as Earth accreted. Subsequently, this ring around Earth would have accreted to form the Moon. The Moon’s rock indicates that it solidified about 4 billion years ago, indicating a formation of the ring of debris at that time. But why should such an original ring have formed at an angle to the band out of which Earth was formed – the ring that provided Earth’s revolution around the Sun – and also at an angle to Earth’s equator?
Impact theory (presently preferred by the sciences): Often cited is the theory indicating that Earth was impacted at an early time by a very large object that pushed or tore enough material out of Earth to form that ring of debris that resulted in the Moon. This theory is based on the assumption that several (up to 10) very large, possibly Mars-size, bodies with odd trajectories were contained in the early solar system. One of them could have caused the impact on Earth that formed the Moon.
An impact of that strength would have influenced Earth’s rotation. The angle of rotation of Earth is only slightly inclined in relation to its rotation around the Sun – resulting in the seasons. The speed of rotation – 24 hours per rotation now, faster in the past – prevents excessive heating during the day or cooling during the night. The impact theory could explain the rather high rate of rotation of Earth. It could also explain the angle of the Moon’s orbit to the Earth’s equator. If the impacting body was part of the solar system, the Earth’s path around the sun could have stayed well aligned with the other planets. Upon the assumed impact, the separated part of Earth would have broken up into small pieces, forming a ring of debris, subsequently to accrete to form the Moon.
.
One cannot leave the discussion of the Moon without mentioning its stabilizing effect on the direction of the axis of Earth. Without a body of that size at that distance, Earth’s axis could change direction as any free-spinning top or wheel would under external influences – in the case of Earth, the influence of the Sun’s (and Jupiter’s) gravitation. A different angle or continuous changes of the angle of the axis of Earth’s rotation relative to its path around the Sun could possibly have had the gravest consequences for the climate on Earth – (possibly by a large degree or at a fast rate in terms of biological evolution) – and, consequently, for the appearance and development of life, as discussed in a later chapter. On the other hand, the alternative – Earth rotating without a moon or with a different moon – has not been thoroughly investigated. Only the example of the planet Venus is used for comparison, with its very low angle of inclination of its axis of rotation. But that may have been the consequence of a very unfavorably aimed impact, not necessarily solely the consequence of lacking a moon.
.
In sum:
In any event, Earth ended up having less crust material than it would have had if the material that formed the Moon had remained part of Earth or had been accumulated together with Earth right at the beginning of its formation. Equally important, Earth was allowed to have a reasonably constant and benign climate for the development and evolution of advanced forms of life. Both of these fortuitous facts resulted from the same impact of a celestial body on Earth. This well-aimed impact of a body of specific size on Earth at the most propitious time can be seen as a most mysterious aspect of Earth’s evolution.
.
.
2.3. The History of Earth
.
Whatever the cause of the forming of the Moon, this event deprived Earth of a large amount of crust surface material. The reduced surface material on Earth was no longer enough to cover the entire surface of Earth – as it does on other planets.
Since some of Earth’s deeper materials, in the mantle and outer core, are like a very thick liquid with high viscosity at that temperature, they form internal convection turbulence like a boiling soup, though at a very low speed.
It now occurred that the specific areas of the mantle that happened to be under the patch of remaining and shielding surface crust material were unable to shed heat and, consequently, arrived at a higher temperature. This always leads to a degree of expansion that makes the hotter material in the mantle and outer core lighter and less viscous – thus permitting it to rise. The area not covered, however, cools more easily and becomes heavier, thereby sinking back toward the core of Earth.
The consequence is that the patch of surface material on Earth over the hot area will be torn apart by the uprising turbulence underneath, moving apart in pieces toward the cooler area where the converging turbulence lets the surface currents flow together to sink and collect the pieces of crust over the sinking core material, to form another coherent patch of surface material in such an area in the course of time. [32]
This movement of parts of the Earth’s surface material became known as continental drift, or plate tectonics, and has already led to the formation of at least three super-continents and their subsequent fractioned redistribution in the course of Earth’s history so far. The last of those was “Pangea” that existed approximately 200 to 300 million years ago (possibly formed in the southern hemisphere out of a combination of the southern super-continent Gondwana and the northern Laurasia). When it broke up 200 million years ago at the rate of approximately 1.5 inches per year (4 centimeters per year), the Atlantic Ocean opened up. At the same time, the ocean to the East, called “Tethys Sea”, became enclosed and compressed, leaving only some disconnected pieces – the Mediterranean, Black Sea, Caspian Sea, and Lake Aral.
Prior to Pangea/Gondwana/Laurasia, the super-continent “Rodinia” had formed and brok up about 800 million years ago. Going back in time, an earlier one did so about 1.5 billion years ago.
The convulsions of the crust of the Earth, the crunching together in some areas and tearing apart in others, led to the formation of mountains, zones of upwelling, depressions, and subduction zones. It also changed the course and intensity of ocean currents. For example, the Gulf Stream – now providing for the temperate climate in Europe – originated only as some large Caribbean islands drifted west and blocked the gap between North and South America, forming Central America.
The plate tectonic movements through the billions of years – specifically through the last 500 million years – had another important effect: They facilitated and accelerated natural evolution – as will be shown in a later chapter. The broken-up continents created numerous different and isolated niches and, consequently, favored the diversifying evolution of life. The multitude of climate changes, some on account of changes in carbon-dioxide content in the atmosphere – subsequent to plate tectonic events, as volcanism and subsequent greenhouse effects – created additional stimulation for natural evolution, as at the time of elimination of the dinosaurs. Climate changes also brought substantial changes in ocean water elevations – varying by hundreds of meters over time – in consequence of glaciations or warming that also added to evolutionary stimulation.
Another consequence of the internal convulsion in Earth’s mantle and core is the formation of a magnetic field, surrounding Earth and deflecting some dangerous radiation. On the other hand, the cyclic changes of the magnetic field are not fully understood, are poorly explained by some thermodynamics and turbulence changes in the core and mantle, and are possibly augmented by self-induction effects, as in some electric machinery in correlation with Earth’s rotation (after all, the ocean currents all run east-to-west along the equator, but west-to-east in northern areas). In any event, the magnetic field changes must be explained differently from the turbulence changes causing plate tectonics.
.
.
2.4 The Early Oceans, the Early Atmosphere, and Climate
.
The origin and evolution of Earth’s oceans, atmosphere, and climate must be considered together. The oceans and the atmosphere have similar origins. Together with climate, all three influence each other in their evolution.
Water molecules and the molecules or atoms that later formed our atmosphere (mainly nitrogen, carbon dioxide, methane, oxygen, and spurious others) were part of the band around the Sun out of which our Earth was formed – though a small part of it only. All these molecules or atoms accreted within Earth and took part in the separation process that let the heavy particles (e.g., iron and nickel) sink toward the center of Earth and the lighter ones form the mantle and crust. Most of the lightest particles were driven to the surface of the atmosphere and may have disappeared in outer space. But some quantities of these particles remained trapped in the mantle and crust and were only driven out to the surface in the course of time through convulsions and volcanism. Every upwelling, as in the Daccan Traps and others, or in present-day volcanism, still brings more water (in the form of vapor) or gases to the surface. The original oceans and atmosphere, most likely formed by material contributed by comets, were augmented by these processes.
The other heavy planets in the solar system (Mercury, Venus, and Mars) lack plate movements and show limited volcanism, which deprives them of any out-gassing phenomena – or they once had momentary and catastrophic out-gassing phenomena, as possibly once on Venus, with catastrophic climatic consequences and the loss of most of the lighter gases of its atmosphere to outer space – possibly the result of the unfavorable impact of another celestial body.
The water on Earth may be merely a product of the formation of Earth. But it is more likely that an encounter or collision with a celestial body, as the one assumed to have formed the Moon – or, most likely, one or a number of comets consisting of ice, as so many others that are flying around – would have left the large amount of water on Earth. Probabilistically, as those comet encounters occurred, this could have been too little water for the subsequent evolution of a favorable climate for life on Earth – or it could have been too much water [33], covering all continents and most of their mountain ranges – leaving little room for the diversified life on dry land to evolve. Could intelligent life ever have originated underwater? (Could extraterrestrial intelligent underwater life be expected, and could it then communicate with us?).
As indicated above, geological convulsion, some volcanoes, and weathering of igneous rock can bring out-gassing of gaseous remnants from the rocky crust of Earth. The enormous eruptions of the Deccan Traps in India and similar large-scale eruptions at other times (for example, in Siberia; see the discussion of geologic catastrophes below) may have been special contributors. The fossil and geological record of Earth indicates enormous climate changes over millions of years, including ocean-level changes of several hundred feet. Such climate changes must be seen in connection with atmospheric changes, whether as cause or result.
The climate effect of high carbon dioxide content in the atmosphere, resulting in a greenhouse effect, was especially important during the early part of the history of Earth. Three billion years ago, when early life began to appear, the Sun had a lower luminosity than today – only 70 percent of its present value. With the present atmosphere, all water in all oceans would have been frozen over at that time and would not have thawed by the slowly warming Sun until about 1.2 billion years ago. But already 3.8 billion years ago, running water was present. By the time the atmosphere had lost much of its carbon dioxide and the greenhouse effect was reduced, the Sun had reached enough luminosity to keep the oceans warm. One can see this as one more of the very surprising aspects of evolution leading up to our environment on Earth.
The climate on Earth was in danger of ending up in either of two catastrophic extremes. If too much vapor had developed early in Earth’s history, the greenhouse effect of this vapor could have further heated the surface of Earth, leading to ever more evaporation. When the atmospheric temperature becomes elevated, more vapor reaches stratospheric height where ultraviolet light can decompose the water molecules into their components of hydrogen and oxygen. The light hydrogen can escape to outer space, thus depriving Earth of ever having any meaningful quantities of water again. This is thought to have happened to Venus [34].
Inversely, if the temperature on Earth had ever been low enough to let large parts of the oceans freeze, the reflectivity of such “white” surfaces would have prevented absorption of solar power, leading to further freezing. Earth could never have recuperated from such a permanent frost – unless it was reduced by volcanic ashes and gasses that, after the settling of the ashes, also led to a greenhouse effect and, combined with the warming of the Sun, to climatic recovery – as possibly happened after some catastrophic basalt eruptions as at the Deccan and Siberian traps.
.
In this context, one should mention the great importance of the anomaly of water. While all other materials are less dense and, consequently, lighter after melting, when in their liquid state – or, inversely, heavier in their solid state – water is different. Solid ice floats on water, being lighter than liquid water. If ice being formed at the surface of bodies of water were heavier, it would sink to the bottom and would soon fill all lakes and most oceans, since warming from the sun would not reach it any longer (only the warming from the inner radioactivity of Earth could). This could quickly lead to a total freeze-over of all of Earth. This is prevented by that strange or most fortuitous anomaly of water that lets ice float!
.
In our intermediate status of surface temperatures on Earth between the freezing and the boiling of water, carbon dioxide plays an important regulatory role. Carbon dioxide is slightly acidic and, thereby, transforms and dissolves earlier limestone deposits (forming the famous caves and carrying along all the calcium that we also find in drinking water), carrying calcium into the oceans. Carbon dioxide also is a greenhouse-effect-producing gas (letting the warming solar light reach the surface of Earth but not the subsequent infrared heat radiation escape). Algae and plankton in the oceans need calcium and carbon dioxide to form their shells which then are deposited as limestone on the ocean floor. Geophysical subduction and subsequent volcanism can decompose limestone and eject carbon dioxide as a gas back into the atmosphere. The regulatory effect comes from higher temperature leading to increased sediment dissolution and increased algae and plankton life that deplete the carbon dioxide in the atmosphere and lead to cooling. Lower temperature leads to a decrease in those factors and an increase in carbon dioxide in the atmosphere, with consequent warming.
The greenhouse effect presently feared on Earth is dangerous on account of its resulting in a dislocation of large parts of the by now stationary population of an overpopulated world – by driving people out of desertifying agricultural areas. Historically, Earth had periods of much higher surface temperatures than the present one, and recovered from them – at whatever very high cost of dislocation or extinction of plant and animal life during those transition periods.
Short-term climate effects are related to sun-spot activity, which are caused by major hot eruptions on the surface of the sun. Earth’s climate is warmer during intense sun-spot periods (augmenting since the 20th century) and colder during quiet periods (for example, Europe’s “little ice age” from 1550 to 1850, only briefly interrupted from 1630 to 1680).
There are some long-term climate effects unrelated to the oceans or the atmosphere. They result from the slow wobbling of Earth (as a spinning top with a 40,000-year cycle) due to its slight bulge and also on account of the deformation of Earth’s path around the Sun (with a 100,000-year cycle) due to the passing Jupiter, that enormous planet just a bit farther out in the solar system. These effects can change the solar exposure for the different parts of the surface of Earth during winter and summer, bringing much colder winters that are not sufficiently reverted in summers, or the opposite.
The famous glacial periods in more recent times are the consequences of these short-term and long-term variations of Earth’s movements. Seen over longer periods of time, they are especially strong in connection with the forming and dissolution of the super-continents when the large land masses show “continental climate” cooling, when reduced seafloor spreading does not produce any carbon dioxide for greenhouse effects, and when ocean currents are redirected. Six major continental glaciation periods have been determined so far, all indicated in millions of years ago (My):
- at 2.800 (My) ago
- from 2.400 to 2.300 (My) ago
- from 900 to 600 (My) ago
- at 450 (My) ago
- from 350 to 250 (My) ago
- from 15 (My) ago to the present (the last episode ended only 10,000 years ago and was possibly mitigated (and a repetitive outbreak prevented) by the effects of the onset of agriculture with its production of “greenhouse” gasses).
Each major glaciation period is possibly combined out of numerous individual episodes. The results of the glaciations are, among other effects, large variations in sea level relative to the land masses due to the binding of water in the ice sheets and augmented by the change of buoyancy of the large land masses with or without ice sheets of the super-continents.
The original ocean or oceans on Earth contained large amounts of dissolved iron, augmented mainly by submarine volcanic activity and the influx of sediments. The dissolved oxygen from the original atmosphere and any other oxygen later formed by algae photosynthesis were absorbed and depleted in forming insoluble iron oxides that resulted in deposits of banded iron formations at the bottom of the oceans. Only after all iron had been deposited out of the oceans could oxygen accumulate in any quantity in the atmosphere – beginning about 2.5 billion years ago and steeply increasing since that time as a product of biological activity.
The original oceans and atmosphere of Earth contained large amounts of carbon dioxide. As experienced from later volcanic eruptions, one must assume that the atmosphere during the early convulsive period of Earth also contained much sulfur. The naked surface of Earth did not give cause for a change in atmospheric content, but the algae-containing oceans did.
Early forms of life in the oceans began to combine dissolved calcium with carbon dioxide to form limestone that was deposited in great quantities on the ocean floor. It took a couple of billion years of mono-cellular algae action in the oceans to slowly absorb most of the carbon dioxide and emit oxygen before the atmosphere had changed to approximately what it is in our time and to leave just enough carbon dioxide for the climate-regulating effect mentioned above.
The change to higher oxygen production and absorption of carbon dioxide accelerated when multi-cellular organisms appeared and the photosynthesis-producing plants came out of the oceans to colonize all the large dry surface of the Earth, all the continents and islands, beginning about 550 million years ago. The size of the plants began to increase rapidly, as this was a specific benefit on dry land (underwater, the Sun’s radiation does not penetrate very deep and an advantage is only in spreading horizontally, but not vertically).
As plant-eating animals appeared, an additional advantage in plant size became apparent (cows don’t eat trees and even giraffes reach only the lowest branches). Plant size increased the absorption of carbon dioxide and production of oxygen.
Our modern time of human civilizations indicates a trend toward much higher carbon dioxide production by means of fuel-burning in power plants and automobiles (combined with the production of other even more dangerous gases leading to ozone depletion, acid rain, and still stronger greenhouse effects – as by Methane). This raises the important question whether the oceans will be able to play their role of absorbing these large amounts of carbon dioxide or whether a substantial greenhouse type of warming will set in
.
One cannot leave this section of the essay concerning the formation and evolution of Earth without recognizing how absolutely standard or normal the planetary development of Earth was in the universe, while at the same time marveling at some of the unique effects and coincidences that made our planet’s climate as comfortably livable as it is. We should expect to find planets like ours (and Venus) all over our galaxy and all over the other galaxies of the universe – around mid-size stars, in areas of their galaxies that were seeded with heavy materials from the many prior supernova explosions and safely outside the central areas of galaxies with their very high radiation from ongoing supernova explosions.
But how often can it happen that a moon formation or other effect left such planets with a partial crust to produce ample plate tectonics, out-gassing of water vapor and carbon-dioxide, and variable niche formation for accelerated natural evolution? [35] How often is the balance found between the retention of enough water for ocean formation, catastrophic vaporization, and eternal overheating as on Venus on one side, or cooling to a point of ocean freezing and eternal winter, on the other? How often is the climate balance by means of carbon dioxide action possible?
.
Our planet Earth may be a special wonder of nature – for us to care for.
.
.
2.5 Resilience in Great Catastrophes
.
Fossil records indicate that five major “extinctions” of up to 99% of all living species have occurred during the last 600 million years – and one must assume some more before that time. Enormous events must have taken place to cause these extinctions. By now, only two causes have been identified:
- occasional impacts of very large meteorites and
- repetitive, very large volcanic eruptions, possibly a combination of both in interlinked events (see the discussion below).
.
The most recent among the very large extinctions, 65 million years ago, wiped out the dinosaurs and with them about 80% of all species. The evolution of mammals followed this extinction that, therefore, became the most studied of all of them. It turned out that this extinction, and another one about 200 to 250 million years ago, can be seen in connection with meteorite impacts as they occur randomly. However, both of those extinctions, as well as all others, were connected to – and, most likely, were caused by – the surfacing of enormous bubbles of highly liquefied basaltic magma that were rising up at random intervals from the D” or other layers deep within Earth [36]. As these upsurges perforated the surface of the Earth, they caused enormous explosions and the delivery of very large quantities of poisonous gases (sulfur and carbon dioxide), some reaching high up into the stratosphere of the Earth, destroying the entire ozone layer and causing copious acid rain. Then followed the formation of large cracks on the surface of the Earth, many hundreds of miles long, some perpendicular to each other, leading to the fast distribution of the highly liquid basalts over very large areas and the delivery of more gases. This occurred in dozens of individual ejections over some time – each one possibly occurring within days and quickly running up to hundreds of miles in distance. Due to related geological events, the surface of the oceans dropped by up to 800 feet, destroying the most abundant, remaining aquatic life in the shallow waters that was not destroyed by the poisonous gases and consequent acid rains.
The most famous basaltic deposits resulting from those events are the Deccan Traps in India, about the size of France and more than 5,000 feet thick in some places. They are connected with the dinosaur extinction. Equally important were the very large Siberian Traps, connected with the earlier extinction of life of the Trilobite era. Areas in Ethiopia, sea beds in the Pacific, the Palisades along the Hudson River near New York City, and an area along the Columbia River are minor basaltic deposits. It appears certain that more catastrophes of this sort will occur at random time intervals in the future.
.
In view of these enormous catastrophes, the resilience of Earth’s atmosphere and climate is specifically noteworthy – always recovering the original and life-favorable consistency – thereby allowing life to recover, though in varied form.
.
.
2.6. Singularities in Earth’s Evolution
.
What are “singularities”?
- Extremely unlikely events (very low probability) that made the appearance of human existence possible
- Events that did occur, but only once, and never occurred again
- Also the non-occurrence of expected events?
.
List of “singularities” concerning the evolution on Earth:
- At the beginning, a suitable dust disk around the Sun; proper composition, unperturbed, properly rotating
- The appearance of the Moon where, when, and as is
- The reaching and maintaining of climatic balance through all catastrophes
.
There are a number of other important factors in the evolution of life on Earth, but they may not be “singularities”, which are described here as valid only for Earth, for example, the magnetic field protecting Earth against some radiation.
.
At the Beginning, a Suitable Dust Disk:
To be suitable for the formation of our life-harboring Earth or a similar one in the universe, the original dust disk around the Sun or another sun in the universe had to contain the distributions of heavy elements that we find on Earth. These, however, result largely from supernovae and can be expected in this concentration in a large area of most galaxies.
The dust disk must be allowed to accrete in a largely unperturbed way, resulting in a number of almost circular bands. A large disturbance could lead to highly elliptical bands and only a few, very large planets.
.
The rate of rotation must be suitable. If the rotation is extremely low, the dust disk could either fall into the central sun or form planets too close to the respective sun, with consequent very high surface temperatures. If the rate or rotation is high, the planets, if forming at all, would be too far from their sun and, consequently, too cold.
The rate of rotation is basically derived from the same cause that brought the rotation of the galactic disk. There may be only a certain range of acceptable rotation rates for disks to form galaxies, with very slow rates leading to a collapse in a black hole in the center of the galaxy, large rotation rates not allowing galaxy formation. Consequently, the rotation rates of solar dust disks within a galaxy may be in a similarly suitable range.
The above indicates that suitable dust disks around young stars for Earth-like planet formation may not be all that rare in the universe.
.
.
The Appearance of the Moon
If the impact theory for the origin of the Moon proves to be correct, then it is the question of the probability of such an impact – to occur at the right time, of the right size, in the right place.
Indications are that about ten very large objects were flying around in our nascent planetary system, all large enough that their impact on Earth could have caused the Moon. Consequently, the impact on Earth had to occur as early as it did. Venus may have been hit by another one, but at an unsuitable spot, causing the low axis tilt and very low rotation of Venus – with the consequent loss of its water and resulting high surface temperature. Any such flying object reaching beyond Mars could have been swallowed up by Jupiter – or could have been decomposed by Jupiter’s gravitational pull and may have formed the Asteroid Belt between Mars and Jupiter. Not enough is known about Mercury to formulate any conjecture regarding early large impacts..
The point of impact, in order to be suitable, had to be such that the resulting axis inclination of Earth and rate of rotation resulted in a life-suitable climate. If Earth is seen as a target with a circular cross-section, about 10% of this target section could be considered suitable – and an equal amount unsuitable, with the balance of intermediate or neutral effect, but not leading to a suitable moon.
Venus may have been hit in an unsuitable area, Earth in a suitable one. Either way, seen from the point of this consideration, the origin of a suitable moon was not as unlikely as is often presented in the literature.
.
.
The Climatic Balance Throughout All Catastrophes:
As indicated in an earlier chapter, a planet like ours is in a delicate climatic balance between overheating with desertification or under-cooling, with total and permanent ice coverage.
The limited observation of our own solar system indicates that Earth-like planetary bodies tend to overheat rather than undercool. It is possible that undercooling can be repaired by large volcanism, as in the case of the recurring trap eruptions (Dacca, Siberia, and others). Overheating would not be repaired once all water is lost – unless a large ice-meteor should impact – apparently a highly unlikely event in the later course of planetary existence. Earth may have had this good fortune of receiving water and vapor during its early formation, when such objects were possibly more numerous in our solar system.
Once life is established and a starting climatic balance given, that balance can be maintained by means of carbon-dioxide regulation, as described in an earlier chapter.
The fact that Earth recovered from the major catastrophes – whether meteor impacts or very large basaltic eruptions (Dacca, Siberia, and others) – indicates a great climatic resilience, capability for climatic recovery, or climatic stability of our planet’s atmosphere. There is no reason to assume that this is extraordinary in the universe.
In sum, the arrival at, and maintenance of, a suitable climate like ours is a probabilistic event, but not one of extreme lack of probability – possibly even of a probability in the single- or double-digit range – that would be a high probability, considering the astronomic number of planetary systems in the universe – leading to the expectation of many more life-inhabited planets in the universe.
.
.
011911
[1] An excellent presentation of cosmic and planetary evolution – also covering the origin of life on Earth, going into detail and a depth considerably beyond this essay – is presented in Peter Ulmschneider’s book, “Intelligent Life in the Universe”, published by Springer in 2003/4, ISBN 3-540-43988-9, 250 pages. Additionally, the swift progress of astrophysics and astronomy requires ongoing awareness of the newest leading publications in that field.
[2] See Edward Tryon, City University of New York, 1973.
[3] A theory proposed by Professor Gott of Princeton University.
[4] This theory was proposed by Professor Steinhardt of Princeton University.
[5] This theory evolved from work done by Leonard Susskind and Yoichira Nambu (since 1969), Andrei Linde, Alan Guth, and others (see their publications). A good summary of present scientific thought is provided by Dennis Overbye’s article in the New York Times, Science Times section, September 2, 2003. One must be aware that the progress of such scientific thought is quite fluid and that new interpretations of string theory may occur at any time.
[6] A number of scientists are involved in this discussion, and a final result is not visible at this time.
[7] See the recently presented theories by E. Rebhan, U. Düsseldorf, Germany; and G. Ellis; together with R. Maartens, both at the University of Cape Town, South Africa.
[8] Webster’s definition of “transcendental”: “Beyond the reach of common thought or experience”. In scientific terms: not describable in physical terms.
[9] A wide selection of books with diverse perspectives on these subjects are presented and discussed in the journal “Science & Theology News” (see www.stnews.org).
[10] See, for example, the publication “Research News and Opportunities in Science and Theology” by the Templeton Foundation (www.researchnews.org or www.templetonpress.org under the “science and religion” tab) or this author’s essay, “Science and Religion: Theology, Astrophysics, and the SETI-Project” (posted on the internet under www.schwab-writings.com/pt/tas/index.html)
[11] Through observation of the structure, spectral emissions, and spectral absorption lines of very distant – and, consequently, very old – cosmic formations.
[12] See the “Theory of Relativity”, proven by observation in this point, but indicating this difference in the flow of time only at very high relative speeds.
[13] Except possibly seven or eight more dimensions of minute extension as assumed by string theory.
[14] The a posteriori development of theories can also be found in the explanation of historic developments, in politics and in economics – even in the private sphere of individual lives. What counts is the reliably predictive value of theories – which far too seldom exists – for there are always new factors or new insights.
[15] This left an ongoing duality in the universe between particles/matter (discrete) and forces/fields (analog) – with transitions between them due to the original energy character of particles, see Einstein’s equation e = mc2 (the energy is equal to the mass multiplied by the square of the speed of light – or the inverse).
[16] With some additional ones having recently been produced artificially, but being of unstable nature.
[17] Lloyd Morgan, in 1923, had already proposed his concept of “Emergent Evolution”, whereby “all properties of matter have emerged from some forerunners …. being effectively related to the systems from which they emerged”, applying this all the way up in evolution, even to human consciousness. The study of “emergence” recently became quite active again, extending also into the study of evolving human consciousness (see James Ogilvy and others).
[18] Evolutionary thrust does not necessarily imply progression to, for example, “higher” forms of life. Some progression is to simpler forms, shedding unnecessary features (see the snakes without limbs or the blindness of organisms in caves, or the evolution of the virus) – keeping in mind that the great cosmic evolution ultimately ends in the extinction of all stars and a cosmic collapse or cosmic dissolution, as discussed later.
[19] Stephen Wolfram, in his book “A New Kind of Science”, follows essentially such a view.
[20] A new theory and observations indicate that such ejecta actually do occur occasionally as black holes “digest” additional material, but possibly perpendicular to the galactic disc.
[21] An ample amount of recent publications can be found at http://adsabs.harvard.edu, specifically at:
“http://fulltext.ads.harvard.edu/cgi-bin/nph-ref_query?bibcode=2003egsa.book.....H&refs=AR&db_key=AST”
[22] A very small galaxy, the Sagittarius Dwarf Elliptical Galaxy, is in the process of being absorbed by the Milky Way.
[23] There is a need for some further explanation of the phenomenon of spiral arms around the core of galaxies in connection with star formation and star movement. Recent theories (or measurements) that the stars circulate the core of the galaxy at twice the rate of the spiral arms. Earth – and stars at the same distance from the center of our galaxy – is assumed to rotate once every 220 million years around the center of our galaxy and happens to be presently in the position of entering one spiral arm. This would indicate that the luminous section of a spiral arm where Earth passes is only about 50 million years of star movement wide. What happens to all the luminous stars within the arms? Do so many of them have such a short life? Also, the spiral arm pattern remains (does not wrap up), while stars closer to the center of a galaxy necessarily circulate faster than distant ones, leading to wrapping. More explanations are needed!
[24] The space between Earth and its neighboring stars in the Milky Way appears very clear. The next star is over 4 light-years distant from Earth. This indicates great emptiness of space around Earth and little probability that another star could be formed nearby. As a matter of fact, it appears surprising that our solar system and the one next to ours could have formed at all with what little gas or dust there was. But there are many dark dust-nebula within our galaxy a few hundred light-years distant from Earth as possible sources of future stars.
[25] Our Sun can be seen as being of medium size in the universe or in our own galaxy, the Milky Way. A large proportion of stars barely reaches ignition of thermonuclear reaction, lighting up for a short time and continuing as “brown dwarfs”. Other stars are larger than the Sun but not as large as those leading to supernova explosions.
[26] At this time, the Andromeda Nebula is still at a distance of more than 2 million light-years from Earth – but that is only some twenty times the diameter of our Milky Way galaxy.
[27] This effect appears to be different in the case of bands in the dust disks around planets of stars; see Saturn. These planetary bands of disks appear to be rather stable. Why bands of dust lead to planets in the case of bands around suns, but do not accrete around planets, is not fully explained.
[28] This implies that the mass of planets resulting from accretion of a band of dust is a matter of probability and could possibly have been much larger or much smaller than what we actually observe in our solar system. What if Earth had resulted to have retained much more or less of the material in its band and had become much larger or much smaller? Would this have led to a different crust with different plate tectonic consequences? Would the atmosphere have been much denser or much thinner with significant consequences for the later origin and evolution of life? Is it another miracle of evolution that Earth turned out to be just the way it now is?
[29] There are other belts of asteroids much further out in the solar system, called the Kuiper and Oort Belts, consisting of small planets and comets, mostly of ice.
[30] There is one more consideration concerning the comets in the solar system. Our Sun is part of a cluster of stars, now dispersed, that formed more or less at the same time out of the same large galactic dust cloud. Any passage of such related stars in the vicinity of our nascent solar system before they dispersed would have resulted in correspondingly significant gravitational impact – and, possibly, the generation of comets from within the nascent system.
[31] The angular-momentum considerations should include the volatile material that was lost from the Moon upon its formation, as indicated above. There may have been volatile material lost from Earth, too. No calculations of this effect could be found in the literature, and no indication whether this would influence the theories.
[32] A good textbook on this subject is “Origin and Evolution of Earth” by Kent Condie and Robert Sloan, Prentice Hall, ISBN 0-13-491820-7.
[33] See Ward and Brownlee, “Rare Earth”, 2000/4, Copernicus, ISBN 0-387-95289-6.
[34] Venus is quite similar to Earth in size and, while closer to the Sun, could still have been a candidate for the development of life, especially while the Sun had lower luminosity in the past. Venus, however, has an atmosphere that now consists mainly of carbon dioxide and a surface temperature of 450 degrees Celsius. It rotates very slowly, requiring 243 Earth days for one Venus day and does so counter-clockwise to Earth. Could one think of an early impact on Venus that vaporized all the water (that once existed there in large quantities, as indicated by the high deuterium-hydrogen ratio in its atmosphere) and almost stopped the rotation? There was an immense outpouring of volcanic basalts on Venus some 500 to 300 million years ago! Could the conditions on Venus be reversed if a large comet composed of ice (as the Halley comet) were to hit it at just the right angle – or would be directed to hit it by future technology? But what could a large impact of one or the other kind do to Earth?
[35] On a more positive note, one could speculate that rogue celestial bodies flying around within nascent solar systems are rather common as the result of collisions upon accretion of the planets. The favorable target area upon hitting another planet in the system like Earth is about 10% to 20%. This would indicate a rather good probability for the origin of another Earth with a life-supportive moon somewhere else in the Milky Way or wider universe.
[36] See the research done by McLean, Virginia Polytech, Jason Morgan, Princeton, New Jersey and Courtillot, Paris, and the book “Evolutionary Catastrophes” by Vincent Courtillot, Cambridge University Press, ISBN 0 521 89118 3.