Why one is Needed and How it might be Derived




НазваниеWhy one is Needed and How it might be Derived
страница6/23
Дата08.09.2012
Размер0.78 Mb.
ТипДокументы
1   2   3   4   5   6   7   8   9   ...   23

Summary

Religions have been developed by the efforts of prophets and their followers, men and women who refined ideas and beliefs about how human life might be improved, and then conveyed these ideas in a convincing manner to others. For this to happen, divine intervention has never been required--everything that such prophets and their followers experienced, witnessed, undertook, or relayed, everything that happened then, and everything that has happened since, can be more realistically explained as being the result of other causes. Nevertheless, approximately five billion (or about 80%) of the world's population state that they believe in a god, and most, presumably, try to obey what they have been told are their god's wishes.159

Today we have over a million religions, all vying for attention, with many of them, in one manner or another, decrying their competitors. Is there no way our moral thinking might be better ordered?

I, for one, am sure that there is. A way that does not deny or attempt to replace any of the existing religions--that would be an insult to some of humanity's greatest achievements and a nonsensical proposition. But it must be possible to unify beliefs under a banner that allows all to embrace both old and new. There must be at least one universal moral code that captures the essence of being human, that defines who we are, states what we stand for, and guides nations when there are difficult decisions to make. An integrated and forward-looking code that might one day constitute the backbone of a universal religion.

The second half of this book begins the search for such an ideal.


CONCLUSION TO PART TWO


Humans have learned much over the last two thousand years. In the past, we made incorrect guesses about the orbits of stars, today we build machinery that replicates their fusing atoms' behaviour; we used to speculate about the nature of blood, today we routinely replace failing organs; a thousand years ago men on horseback spread the news, today we employ the light-speed of electromagnetic waves.

All such progress depended, and will continue to depend, upon one thing--the ability to identify and root out faulty assumptions and replace them with facts. In other words, progress necessitates recognizing that the universe (and all that it contains and everything that happens) is rational. Once we do this, we realize that all situations can be analyzed and treated logically. Then, given enough time and effort, almost anything becomes possible--even by-passing emotionally-charged, long-standing, religious differences.

We have employed a rational approach in every field of human endeavour except religion. There, we fight new understandings, progress, and each other. No time has ever been more appropriate than the present to investigate alternative ways to meet our religious needs. Religions are not beyond betterment; they can incorporate new understandings, they can be redesigned. The rational approach can be used, even in the field of religious belief.

Science and religion have not always been strangers to one another. In Ancient Greece all speculative thought was considered to be philosophy; science and religion were (and often still are) speculative in nature. Both might profit from a tighter union for both address aspects of the same problem--our lack of knowledge. Most spiritual religions attempt to explain the creation of the universe and the planet's organisms; many scientists work on exactly the same questions. However, religion and science operate at different ends of the knowledge gap. Religion starts at the "big end" with all the answers, usually declaring at the outset that a supreme being created all; science works at the "small end" and begins by asking questions, slowly building an understanding of the whole from a thorough examination of its parts.

Religion and science have another feature in common: both are founded upon a belief. While the belief held by religions is invariably made clear for everyone, the belief held by scientists is usually overlooked--however, it is just as fundamental and important.

Scientists, without exception, believe that all of the universe's behaviour is rational, i.e., that effects follow causes which follow effects (the causality discussed in Chapter One). Religions, apparently sensing that some aspect of this belief counters theirs, invariably state (in one way or another) that some parts of the universe are not subject to rational inquiry.

Because science and religion are both based upon a belief, I suspect that unifying these beliefs would fully unify science and religion. Although not its intended purpose, the last half of this book seems to be showing how this might be brought about. Essentially, the belief that heads both disciplines is that which is used by each to make purposeful decisions. Religious beliefs regarding a judgement day and an afterlife influence behavioural decisions made by followers. Scientific beliefs that the universe is causal or rational determine the accuracy of solutions proposed by scientists. Both beliefs provide the "purpose" needed by the decision maker to make a choice about how to act--the religious in order to enter heaven, the scientist in order to have his or her findings accepted as valid.

To my mind, there is no reason for the purpose that heads scientific inquiry to be any different from the purpose that heads a religion. The problem is--how might such a joint purpose be stated? "To seek the truth," might be accurate, but this is too simple a statement to have any practical utility. (The purpose proposed toward the end of Chapter Nine may be a more useful one.) I leave this as a problem that some readers might like to take up. What a foundation for future civilizations to build upon would be created, should scientific and religious purposes become one!


Part Three: Purpose


INTRODUCTION TO PART THREE


What better way to commence our search for a universal religion than to examine what is currently known about the universe and its living contents? Using knowledge carefully compiled over many centuries and replacing assumptions with facts--this is, after all, why the majority of us no longer live in caves.

Communal decision-making (moral or practical) is facilitated by valuing the attainment of a communally valued purpose, one which is readily recognized as applicable to all--a universal purpose. Unfortunately, as the next two chapters relate, to the best of our current understanding nothing about either the universe or life necessitates that they be purpose-driven. Scientists can't prove that a purpose was necessary for the universe or life to form; neither can they prove that a purpose was not necessary. All they can state is that both the universe and life are present, both change over time, and nothing more than that described by a few laws, principles and theories of physics is needed to explain their existence and ensure their evolution. As Chapter Nine notes, our current physics is not powerful enough to determine whether or not a purpose existed before our universe began--the only place a predetermining purpose might be found.

However, there is a possible way around the dilemma created by our failure to find a universe-governing purpose. This is discussed in Chapter Ten which suggests that a possible consequence of life's behaviour could be used as a "surrogate" purpose. It turns out that this "consequence" has a number of valuable contributions to offer (it can readily be used to guide moral decision making, for instance--an exercise explored in Chapter Thirteen). Part Three concludes by constructing a reason to think that the "possible consequence" might even be a "probable consequence" (which would greatly increase its value, should it be adopted to be the "purpose" that heads a universal religion).

But first, we must update Genesis I.


CHAPTER SEVEN: THE UNIVERSE


Most of our discoveries about the universe have come through collecting and studying electromagnetic radiations. For many centuries, visible light waves were the only kind of radiation we could detect, and we could not do much with them until Galileo constructed his telescopes. But the electromagnetic spectrum holds much more information than that contained in the light waves visible to our eyes. The full spectrum ranges from very long radio waves, microwaves and the infrared, through the rainbow's hues, to ultraviolet, X-rays, and highly energetic gamma rays. Our ability to understand what is happening throughout the universe depends upon our ability to invent, build and utilize instruments able to gather in these waves, remove spurious background noise, then to amplify, analyze and make sense of the minute differences so revealed. The past few decades have opened many electromagnetic inspection windows, and the next will undoubtedly open many more. Thus, what follows in this chapter will certainly need to be updated as we learn more, but the chapter's major premises will likely remain valid, for they are supported by many millions of solidly based observations.

Let us begin this explanation of what has been discovered about the universe by describing just a little of what everyone can readily see. We will then use the laws of physics and the "causality principle" to extrapolate backwards in time; this reveals how things must have been in the past to cause them to be as we see them today.

1. What we see in the Sky

Who has not looked at the sky on a starry, cloudless night and felt the wonder of living on a planet surrounded by so many mysterious shining points of light? Two thousand years ago, many thought that most of these were merely copies of each other, and that they were positioned on one of several "shells" which surrounded the Earth--a very uninspiring arrangement. We now know how incorrect that view was, and any reasonably good backyard telescope can provide hints about how our new perspective was obtained. It can be seen that these points of light are not all the same: many vary in brightness, some possess tinges of colour, and, while most hardly ever change their position relative to one another, a few move about from one night to the next, and the whole rotates with the time and season.

Even four hundred years ago it was not generally known that the Earth and planets are satellites of the sun. Although the Greek astronomer Aristarchus (around 250 BCE) had guessed as much, most preferred to believe otherwise. The Catholic Church had adopted Aristotle's cosmology, and it maintained that three concentric spheres or "shells" encompassed the Earth, with the sun and moon moving on the surface of the first sphere, the planets moving on the second, and all of the stars being at rest on the third.160 This conformed to the notion that a perfect heaven awaited above (while volcanoes and hot springs were said to prove that hell and brimstone lay beneath). There is a well-known story of how Galileo,161 after careful use of a telescope he had constructed, declared in 1616 that Copernicus was right and that the Earth and planets did revolve around the sun; this led to the Church placing Galileo under house arrest for the rest of his life.162 However, the increasing use of telescopes gradually altered popular opinion, and by the middle of the seventeenth century most astronomers agreed that the sun-centred description was correct.

A six-inch telescope and some careful scrutiny will uncover numerous small, fuzzy patches of light in the night sky. Careful observation at higher magnifications shows that these are actually collections of stars, or galaxies. Galaxies, typically comprising thousands of millions of stars, mostly appear in one of three arrangements: elliptical, spiral163 or irregular. Astronomers further find (through careful examination of photographs taken using giant telescopes) that galaxies themselves collect together in groups and clusters, and that these clumps form even bigger collections. The size of these massive groupings (called superclusters164 and galaxy walls) can exceed many hundreds of millions of light-years.

Astronomers have also observed several pairs of galaxies colliding. This sounds catastrophic, but it produces nowhere near the (relative) damage caused, for example, when comets or asteroids crash into planets. This is because galaxies are vast (which is another way of saying that they are mostly empty space) and one galaxy can pass right through another with relatively few direct impacts (orbital disruptions would be much more likely to happen).165

A number of dark patches are also noticeable in the night sky, areas which seem to be devoid of light-emitting stars. One well-known dark region can be seen in the Great Orion Nebula forming part of Orion's sword and lies some 1500 light-years away. (The reason such dark patches exist is explained in section four of this chapter.)

Stars, galaxies, superclusters, and other objects in the universe have been photographed, numbered, catalogued and intensively studied for decades. Their brilliance, variabilities, emissions, compositions, movements, ages, and much else, have been repeatedly measured by a wide range of very powerful instruments. Over years of study, it has been found that most objects and phenomena can be grouped into categories, and these have been given names (for example, white and brown dwarfs, red giants, neutron stars, gas giants, black holes, Cepheids, pulsars, quasars, novae, supernovae, and so on). Much has been learned in just a few decades about the nature and properties of members of each category, but a great deal more remains to be discovered.

By studying the variations in intensity of emitted radiation, astronomers have found how to measure the distance between Earth and a particular kind of varying star called a Cepheid variable. By associating these stars with galaxies, it has been determined that the light from the most distant galaxies has been travelling for more than thirteen billion years! This means that, when viewing those galaxies, we are looking at something that is about 12x1022 kilometres away (calculated by multiplying the distance light travels in one year by 13 billion), and, perhaps more significantly, it means we are seeing light that was emitted from them as they existed over thirteen billion years ago.166 To see these galaxies as they exist today, we would have to wait another thirteen billion years for their current emissions to reach Earth (or we would have to instantaneously travel 12x1022 kilometres to where they are, an impossibility). Knowing how far an object is from Earth has allowed astronomers to "look into the past"--the farther away a celestial entity is, the older the light we are seeing. Thus, the properties of distant objects can be examined and compared to closer (i.e., younger) emitting bodies. Such analyses have led to many meaningful discoveries about the origins of our universe and its evolution over time.

Some eighty years ago astronomers discovered that the spectral emissions167 from all distant objects are displaced, i.e., that their spectral dark bands168 have been shifted from their normal position. All galactic radiation (except that coming from a few, nearby, galaxies) shows spectral lines that have been moved toward the red end of the spectrum; this has been termed the "red shift."169 This phenomenon has been found to occur in every direction we look, and means that all distant objects are moving away from us. In fact, the farther away an object is, the faster it recedes.170

Unfortunately, for those who would have otherwise, this does not make us unique. Although it seems to place the Earth (and therefore humanity) at the centre of the universe, this is not the case. The true explanation is that everything is moving away from everything else, because the intervening space is expanding rather than the objects themselves moving. (They do move, of course, just as our planet moves around our sun. Our sun travels around the centre of our galaxy, and galaxies themselves move. But galactic recession is due to space expansion. Space expansion is perhaps most clearly visualized using the analogy of specks of dirt on the surface of a balloon. When the balloon is inflated, the distance between each speck increases, and those furthest apart separate at the greatest speed, but no speck is more centrally positioned than any other.)

Finding that billions of galaxies exist, each containing billions of stars, has been exciting. Finding that they are speeding away from each other was at first unbelievable, then astonishing, and it immediately claimed the attention of all cosmologists. This galactic recession (or expansion of the universe, which is another way of saying the same thing) was so fundamental and far-reaching an observation that few astronomers could concentrate upon any other issue--an explanation had to be found.

2. The Expanding Universe

Two competing theories quickly emerged to explain the expanding universe phenomenon: the Steady State theory and the Big Bang theory. The first postulated that the universe is self-sustaining, and claimed that what we see today is what will be seen in billions of years time; galaxies move apart, but the total picture remains the same. According to the Steady State theory, the stars that are moving outwards are being replaced by new ones that are perpetually being formed out of cosmic dust. This dust is being created from atoms, the theory went, that themselves are being continuously created from cosmic energy. (We cannot observe this creation, because the theory predicts that it need only occur at a rate of about one atom per 500 cubic meters, every 1000 years,171 which is far too slow to be detected.)

In contrast, the Big Bang explanation stated that the universe began with an explosion, and that everything within has been moving apart since that moment, with the intervening space expanding and cooling172 as it proceeds. In this theory, everything was created during, or shortly after, "the bang," rather than slowly and continuously, atom by atom.173

I remember reading some of the discussions reported in the press when these theories were announced, shortly after the second world war. They provided a stimulating intellectual alternative to the dreary task of becoming formally educated. At that time, I favoured the Steady State theory because I couldn't understand how everything could come from nothing in one big burst. Creation seemed slightly more feasible if it happened very slowly, and I thought that perhaps the atoms being created came from energy released as the matter in receding galaxies became stretched further and further apart.174 The Steady State theory also seemed more appealing philosophically, because if the universe continued forever, one would never have a beginning to explain.

However, three observations eventually dismissed the Steady State theory. First, if the universe did start with a bang, then there should still be some trace evidence of this explosion to be found. And there is; it has been heard since radio astronomy first began. Everywhere one searches, in addition to the electromagnetic information received from stars and galaxies, there is a constant hiss of background radiation. This hiss comes from energy that remains (unconverted into matter) from the originating Big Bang.175

Second, the universe does not remain the same over time, as the Steady State theory requires; it changes as it becomes older. This was discovered when quasar locations were established upon a four-dimensional map of the universe. This showed them to exist only at great distances from our system, signifying that they were present billions of years ago but no longer exist today.176 Astronomers also find (by searching far and near in distance, and so effectively far and near in time) that galaxies tend to change their shape as they age.

Third, scientists have calculated the variety and abundance of chemical elements that should have been formed following the Big Bang, and their calculations predict exactly the ratios that are found to exist in space. Furthermore, the particular mixture predicted by the Big Bang theory (and corroborated by observation) is quite different from the mixture that the Steady State theory predicts.

Various other kinds of evidence support the Big Bang theory, and it rules the roost today.177 The creating Bang is calculated to have occurred about 13.7 billion years ago.

While no cosmologist doubts that our universe is expanding, there has been much debate about whether it will continue to expand forever. Should this be the case, our universe will end up as a diffuse, dark, frigid, dead junkyard, with no energy differences left to power change. If, however, the attractive gravitational forces are strong enough, the universe's current expansion will be slowed down, stopped, then reversed. This reversal would cause everything to be pulled tighter and tighter together, and it would all eventually be gathered into one gigantic black hole, presumably to continue shrinking until it reverted back to whence it came.

This uncertainty about the universe's future may have been resolved by measurements taken over the last five or so years. Measurements of the brightness and red shift of distant supernovae (see next section) yield the recession speed of the universe when it was young. Comparisons of that speed with the recession speed shown by nearby galaxies reveals that the universe's rate of expansion is increasing, not slowing down.178 (It is currently thought that the slightly repulsive gravitational force of the "vacuum energy"179 of empty space may be causing this acceleration.)

3. What Happened after the Big Bang

The Big Bang theory postulates that the universe came into being when what amounts to an infinitely large amount of energy suddenly appeared as an infinitesimally small speck (fittingly called a singularity). Where this energy came from--no one knows.180 How so much energy could occupy next to zero volume--no one knows. One theory postulates the existence of another universe, vastly bigger than the one we inhabit and hidden in additional space/time dimensions, and suggests that it could have created and fed the singularity. This background universe could be periodically "blowing bubbles" that inflate into universes.181 Our (relatively small, on this scale) universe could have originated within one of these bubbles.182 Superstring Theory (see "The Conservation Laws," a postscript to Chapter Seven) supports the existence of many universes (of which ours is one), each being formed from, and eventually returned to, empty space.

Regardless of what actually occurred to "begin our universe," and what was needed before this event to cause it to happen, scientists can account for what is seen today simply by postulating that everything came from a single point in one Big Bang then applying some known laws of physics.

Rather than making guesses about what might have happened beyond and before our universe began (guesses that can never be substantiated--see section six of this chapter), let us start with what is generally accepted--a Big Bang/Inflationary origin to our universe. This theory is able to explain much that we observe, and it yields accurate predictions, hallmark properties of a good scientific theory. Assuming that the laws of physics as we know them today also applied almost immediately following the Bang,183 we can reconstruct the history of the universe. This has been carried out by various people over the past fifty years, with modifications and revisions being made each time someone was able to improve the fit between astronomical observations and theory. Today, scientists think that something very like the following occurred.

Immediately upon the original insertion of energy, time in this continuum began, and space was created by separating energy components. This was followed by an extremely rapid expansion. Starting about 10-37 of a second after the Bang,184 and lasting until about 10-34 of a second,185 this minute bubble of pure energy that was to become our universe inflated to 1050 times its previous size.186

For the first one hundred seconds or so following the Bang, only energy (in various forms of radiation) could have existed.187 Continued expansion and further cooling of this hot dense ball of energy continued until, after about 300,000 years,188 the temperature was low enough (about 3,000°C) for atoms of hydrogen (and helium, the next lightest element) to remain intact. From this time onward the universe would contain matter.189

These atoms of hydrogen and helium190 continued to move apart, and the temperature of the universe continued to drop. Gravitational forces pulled wisps of atoms closer together, forming tremendous, irregularly shaped clouds, and these eventually further condensed to form many giant gas balls. Condensation continued, with the gases at the centre of each ball forming first black holes, then supermassive black holes.191 Electrically charged gases (spiralling ever faster and faster around these holes before being swallowed) emitted intense electromagnetic radiation fields that pushed the surrounding gases away. Clouds of these gases then themselves condensed to form additional smaller balls. As gravity pulled the gases in each of these balls tighter together they began to heat up. Eventually the temperature within each became so high that thermonuclear reactions occurred, and the gas balls began to emit light. These high-temperature, hydrogen-gas balls, are called stars.192 The large collections of stars that rotate around supermassive black holes are called galaxies.

4. The Life of a Typical Star

Stars contain huge amounts of hydrogen, and the gravitational forces near their centre are extremely high. This creates a pressure which pushes the hydrogen nuclei closer and closer, eventually fusing pairs of them together, creating helium. Since one helium nucleus has slightly less mass than the two hydrogen nuclei that formed it, the surplus mass has to be released. This occurs, but the release is not in the form of a particle of matter; the mass difference is radiated away as energy,193 and many such fusings quickly raise the sun's core temperature (which stabilizes at about twenty million degrees Celsius). Physicists replicate this process in hydrogen bombs,194 and they are attempting to do the same thing in the laboratory. (Here the biggest problem is how to contain and control the high temperatures involved195--about 100 million degrees, or over five times the temperature of the sun's core, in some research reactors.)

The average star today196 burns for about ten billion years. As a star's hydrogen continues to form helium, its core gradually shrinks. This causes it to become hotter, and its nuclear fusions become more complex. Through fusions, helium is converted into carbon and oxygen, then into other elements (those in approximately the first quarter of the periodic table). Further core shrinkage eventually creates enough radiation to induce a big expansion of the outer layers, and stars that are about the size of our sun become red giants, enveloping any orbiting planets in incandescent gases. Eventually, fusion can no longer be sustained in the core, and red giants shrink, lose their outer layers of gases, and become compact white dwarfs. This is likely to be the fate of our sun and its planets, some six billion years in the future.

A number of stars are large enough to avoid this kind of relatively slow death. Their extra mass creates higher core temperatures and heavier elements are formed. However, forming nuclei of elements beyond iron requires an input of energy (because extra energy is needed to hold together the many mutually repulsive protons such nuclei contain). This reduces the energy released during fusion to a point where it can no longer counterbalance gravitational attraction, and the star collapses. This sudden implosion releases tremendous amounts of energy and everything immediately heats up again. This, in turn, rapidly fuses many of the existing elements into the larger and more complex elements that exist beyond iron (over eighty of them; copper, silver, gold and mercury, for example). The core's raging furnace builds in intensity and soon explodes, scattering the star's chemical elements into space. Some massive stars undergo several cycles of explosions and collapses. (Astronomers occasionally witness these events; each explosion is termed a nova.) Other giant stars explode completely in one detonation; what is then seen is called a supernova.197 Both appear abruptly as bright patches of light in the sky, often intense enough to be visible in daylight, occurring in the spot formerly occupied by a star.198

Observers find and study one or two new novae each year, and witness gigantic supernovae blossoming within our galaxy, the Milky Way, an average of twice a century. In the ten billion years of our galaxy's existence,199 about two hundred million supernovae have spewed out the chemical elements we know from spectroscopic evidence to be present throughout its volume. The dark patches (mentioned earlier in this chapter), observed within interstellar and intergalactic space, are due to the presence of vast clouds of these minute dust particles. This dust (altogether amounting to hundreds of times more matter than is contained within the total of every galaxy's collection of stars and planets) is mostly composed of the elements formed and ejected during novae and supernovae explosions. These particles absorb and obscure light from the stars and galaxies that lie beyond, and it is the absence of this light that produces regions that appear to be dark.

The visible universe is estimated to contain some 100,000,000,000 (100 billion) galaxies, and an average galaxy (such as ours) accommodates a collection of some 2-300,000,000,000 (200-300 billion) stars. Thus, there are twenty to thirty thousand billion billion (i.e., 20-30,000,000,000,000,000,000,000, that is, 20-30 sextillion, or 2-3x1022) stars all told in our universe.200

As mentioned, stars of all descriptions have been found.201 Some, only about a half-million years old,202 have been photographed via the infrared radiation they emit. These newly formed "baby" stars already show a spin (imparted by the kinetic energy of condensing gases as they are drawn into the star by gravitational attraction), which the star retains for its lifetime. Observations suggest that about half of all newly formed stars are also accompanied by a rotating disk of gases, particles, dust and debris. Matter that is not pulled into the star is gradually pushed away by the star's radiation and most eventually disperse into space. However, gravity also pulls some of the disk's matter and dust together to form aggregates; the largest of these we call planets.203

The brightness and remoteness of stars generally prevent us from directly observing any planets that might orbit them.204 However, the presence of planets can be inferred by various techniques, and some nearby stars are now known to have orbiting bodies. One way to determine if a star has one or more planetary companions is to measure its wobble205 (caused because the orbiting bodies together rotate about their common centre of mass, i.e., the star no longer rotates about its own centre and therefore looks as if it is "wobbling." A similar wobble can occur when a car tire is "unbalanced.") Another way to find planets is to look for lensing effects, when light from distant stars becomes bent due to gravitational pull as it passes close to large masses, such as those of giant (e.g., Jupiter-size or greater) planets.206 Astronomers also look for emission intensity variations and dark spots transiting the face of stars (caused by planets crossing in front of a star and so preventing some of its light from reaching the observing telescopes).207 The presence of rings of matter surrounding some stars gives observers yet another way to infer that planets have been (or are being) formed about a star, and circular gaps within such rings of dust almost certainly mean that planets are present. (Clumps of particles within a ring gravitationally sweep up additional dust as they travel around a star; this causes the orbiting bodies to gradually enlarge and leaves the gaps that are seen. These dust aggregates may ultimately become large enough to form asteroids and planets.208 Most stars, including our own, lose much of their dust halo due to this process [as well as due to pressure from the star's radiation] in the first 400 million years following their birth.) Planets may also be sought and even studied by examining the doppler-shifted starlight scattered by their atmospheres.209 Over one hundred exoplanets (as planets outside our solar system are called) have been found to date, a number that is being added to every few weeks. Undoubtedly, with time and as astronomers refine their planet-finding techniques, many more will be discovered.

5. The Earth

The Earth was formed (as were all of the planets in our solar system) from the aggregates that orbited our sun approximately 4.6 billion y.a.--less than half a billion years after the sun itself formed (and about 9 billion years after the Big Bang). As it was forming, the Earth's accumulating mass was constantly bombarded by matter-adding meteorites, comets and huge planetesimals (mini-planets), and this, together with the energy released by radioactive decay of the heavy elements that settled to its core,210 kept our planet in a molten state for its first two or three hundred million years. The Earth's solid surface crust formed about four and a quarter billion y.a.211

Today, our planet consists chiefly of a liquid iron alloy core (at a temperature of approximately 5,000(C212), covered by a mantle of hardened oxides that float on the core's surface. The core is slowly cooling as convection currents and eddies in its upper layers transfer heat into the mantle. These currents also cause the Earth's continents to drift, almost imperceptibly, but constantly. In several places, subterranean tectonic plates bump into each other, inevitably pushing one under the other. The uppermost plate (usually the lightest one) lifts to form mountains, with rifts, or valleys, forming in between. The plate pushed underneath remelts to form magma, some of which may find its way to the surface again through volcanoes.

Most of the water that covers three-quarters of the Earth's surface arrived in the form of comets early in our planet's life, but another 500 tons or so is added daily as the Earth sweeps up space-dust (much of which is water213). Water is ubiquitous throughout the universe simply because its constituents (two atoms of hydrogen, and one atom of oxygen) are elemental and universal--hydrogen being the first element formed following the Big Bang, and oxygen being one of the elements produced as stars evolve, and later thrown into space as they nova.

As we doubtless remember from our school days, the sun's radiation evaporates water (that then condenses to form the clouds that produce rain, lightning and thunder). The sun's energy also heats the land and sea; temperature differences between these create winds and drive the water cycle that sustains life on land.

More than three billion years of continuously varying weather has eroded the Earth's ever-changing mountains, turning their rock into the sand, dust and silt that have become major constituents of our planet's soil and the bottoms of its lakes, rivers and oceans. Silt and material on the ocean floors, compressed by the weight of water and accumulated matter above, has formed layers of sedimentary rock that trap and hold evidence of the conditions and life forms that existed from the recent past to many hundreds of millions of years ago. Ice locked at depths within glaciers provides ancient liquids and gases that scientists have collected and analyzed, further adding to what is known about how our planet aged and changed. These sources have also told us much of what is known about how life evolved on our planet.

6. What Started it all?

Although we can conjecture, we are never likely to find out what caused the Big Bang; that is, what created our universe in the first place. The reason this is so is to be found in at least two places: Gödel's Incompleteness Theorem, and General Systems theory. These are not too hard to understand in outline, as the brief summary given in the next two paragraphs aims to show. (A little more information is provided in postscripts to this chapter.)

In his Incompleteness Theorem, Kurt Gödel proved that no system can contain all of the information needed to answer every question that can be posed from within that system. No matter how much we understand about the system we are examining from within, logical paradoxes will always exist. Asking what started our universe is posing just such a logical paradox

General Systems theory states that all systems are either open or closed. Open systems interact with (and obtain what they need to continue their existence from) their supersystem.214 Closed systems are cut-off from the outside, and no energy of any form (e.g., radiation, matter, or information) can enter or leave such a system. All our current theories suggest that our universe is a closed system, and, if this is so, we will never be able to obtain information from outside.

1   2   3   4   5   6   7   8   9   ...   23

Похожие:

Why one is Needed and How it might be Derived iconThe family name Reoviridae is derived from the prototype “reovirus” strain of the genus

Why one is Needed and How it might be Derived iconThe Messiah will only come when he is no longer needed

Why one is Needed and How it might be Derived iconPaper title (maximum two rows if needed)

Why one is Needed and How it might be Derived iconChapter 1: Hop (Humulus lupulus L.)-derived bitter acids as multipotent bioactive compounds

Why one is Needed and How it might be Derived iconToward a Method for Providing Database Structures Derived from an Ontological Specification Process: the Example of Knowledge Management

Why one is Needed and How it might be Derived icon1997: Snowmelt on the Greenland Ice Sheet as derived from passive microwave satellite data. J. Climate, 10, 165-175. (Klima) Ahlnäs, K., and G. R. Garrison, 1984

Why one is Needed and How it might be Derived iconImplement a method for refining comparative models based on remote homologs by combining the “ zippers ” strategy for sampling protein backbones with restraints derived from bioinformatics

Why one is Needed and How it might be Derived iconTo deliver the Earth and Life Sciences discoveries needed to meet the challenges society faces as stewards of our changing planet

Why one is Needed and How it might be Derived iconDiscusses the work of loggers, activities at sawmills, various products derived from trees, and measures taken to insure a continued supply of lumber. Grades 3+. Isbn: 0671340077, found library

Why one is Needed and How it might be Derived iconValidation of Atmospheric temperature profiles derived using Neural Network approach from amsu-a measurements onboard noaa-15 and noaa-16 satellites and their

Разместите кнопку на своём сайте:
Библиотека


База данных защищена авторским правом ©lib.znate.ru 2014
обратиться к администрации
Библиотека
Главная страница