To Examine Beliefs
Inventory of Philosophical Beliefs
First Principles (The Top-Bottom Approach)
The Tone of the Past
A Grand Vision of Philosophy
The Romantic Era's System: Idealism
Revolt against Idealism
New Trends
Metaphysics Discredited
Well-Founded Metaphysics
A Prison of Certainty
Metaphysical Study and Modest Gains
The Metaphysics of the People
Looking Ahead in This Book
The Next Two Books
Sense Experience
The Road to Modern Skepticism
The Observations
Confirmation
Clear and Distinct Objects
Universal Agreement on Objects
The Existence of Objects
I Am an Object, Therefore I Am
I Perceive, Therefore I Am
Descartes' Agenda
Object Deniers
Nonphysical Objects and Ghosts
Two-Dimensional Ghosts
Projected Two-Dimensional Images
Extra-Galactic Matter
Images from Nothing
Descartes' Dream Approach
Images Inside the Mind
Physical Objects inside the Mind
Two-Dimensional Images in the Mind
Dreaming Neurons
Confusion of the Mind
Chapter Summary
Reliance on Science
Relevant Scientific Issues
Physics: The Smallest Things
Inside the Atom
More Subatomic Particles
Quarks
Cooperative Quarks
Bosons: Force Carriers
Electronic Action
The Inception of Quantum Theory
Wave-Particle Duality
Particular Uncertainty
Superposition
Quantum Entanglement
Nonlocality
Everyday Perception
Alternative Interpretations
Need More Study
An Evolutionary Standpoint
Accepting All the Physical World
Flapdoodle
Chemistry: The Actions of Atoms
The Work of the Electrons
Growth of the Earth
Composition of the Earth
The Ingredients of the Ground
The Rock Cycle
The Hydrologic Cycle
Hades
Early Ideas on Weather
Meteorologia
Air and Water
Air Pressure
The Wind
Cyclones
Ocean Currents
Fierce Storms
Lightning
Hurricanes
Chaos Theory
Implications
Historical Highlights in Cosmology
Discoveries After 1900
Disreputable Territory
The Cosmic Background Radiation
Ground Zero
Planck Time--10-43 Second
Inflation Era
The Electroweak Era
The Quark Confinement Era
The Neutrino Era
The Nucleosynthesis Era
Coalescence of the Atoms
The Matter Era
On to the Stars (Suns)
Galaxies
Stars as Ovens for Elements
Our Solar System
Contemporary Problems
The Future of the Earth and Sun
The Universe Expanding Onward
What is Life?
Chemical Constituents of Life
Proteins
Carbohydrates
Lipids
Ions
Carbonic Compounds
How Life Works
History of the Inhabitants of Earth
Entry of Organisms
The First Animals
Rise of the Mammals
Summary
Neurons
The Nervous System
The Triune Human Brain
Chemical Messengers
Brain Analysis
Chapter Conclusion
In all parts of the world, disputes are always in progress. This has been the case since humanity began. There is ample friction in families and between neighbors. While these disagreements occur on a small scale, they can bring tragic consequences. Then there are the continuing quarrels between different groups in countries and even across transnational boundaries. Violence and war have come out of this. There are various reasons for this turmoil.
An important reason is difference in beliefs. Some beliefs are held with rabidly emotional intensity. That can lead to rigid opinions that become closed to considering facts and enlightened values. This can eventually lead to cruel, authoritarian institutions. The task then is to find the correct facts and the conclusions that follow from them. This could lead to a unity of belief among humans and a corresponding general peace and unity. It is something we should all work toward.
To Examine Beliefs
With this in mind, it is my goal to examine certain beliefs that contribute to great division. I will try this with the aid of philosophy, a subject that has traditionally examined beliefs closely in order to determine what is correct. I have written three philosophy books to accomplish this task. They comprise a trilogy, The Meaning of the Universe. The first book is this one, The Predominance of the Physical World. The second one is entitled Knowledge and Free Choice and the third one, The Search for God.
The consideration of a belief can involve examination of a large set of underlying beliefs that can involve wide-ranging areas such as the cosmos, the world, and human nature. When a set of beliefs ranges that far, it can include what are called metaphysical beliefs. The word "metaphysical" has a number of different meanings. In this book a metaphysical belief will be taken to be simply a very general and fundamental one about life and the universe.
Starting with such basic, foundational beliefs, philosophers have constructed comprehensive metaphysical systems that purport to explain all of existence. It is the aim of this book to construct such a fact-based metaphysical system with the hope that it will help bring a greater harmony of belief among people. The system will be an abbreviated one, however. Many issues will of necessity have to be simplified, and there will not be the time to deal with other issues at all.
Most people do not question their own metaphysical beliefs. They usually cherish, guard, and defend them closely. Philosophy long ago took on the task of examining beliefs to see if they could be properly justified, and for that reason its path in trying to see how to come to sound opinions will be explored. The record of philosophers has not been perfect. They have sometimes fallen short of the mark and failed to subject their own beliefs to rigorous examination. Plato, for instance, left his celebrated "Ideas" vague and perplexing. Rene Descartes posited God to help explain his claim to certainty but never justified his basis for certainty in the existence of a God. It was probably the Inquisition that made Descartes fearful of discussing even a theoretical doubt in the existence of God.
In the 1800's, a number of philosophers became engaged in designing vague, speculative, and grand metaphysical systems. Much of this was inspired by Immanuel Kant and George Wilhelm Friedrich Hegel. Around 1900, two philosophers, G.E. Moore and Bertrand Russell, made a concerted effort to analyze philosophical ideas very closely, taking particular aim at grand metaphysical systems. They were followed in their quest by Logical Positivism based in Vienna and by analytic philosophy. Both movements went far in discrediting the 19th century speculative system approach. Unfortunately, they also discouraged the study of even rigorously argued metaphysics.
Russell never completely abandoned an interest in metaphysics, at least of the nonmystical kind. His professed approach was to first carefully examine philosophical ideas. With that approach, the small philosophical problems would be solved. Once the smaller problems were solved, philosophers could more comfortably proceed to put it all together and solve the big problems of philosophy. Russell's student, Ludwig Wittgenstein, believed--at least at one time--that all philosophical problems were the result of confusion in language. Once the linguistic conundrums were solved, the philosophical ones would simply melt away. Hence, there was no need to attack the big problems directly. Russell did not get very far toward solving the small bedrock problems. Wittgenstein's idea that all philosophical problems were at bottom linguistic ones, while given consideration, never gained wide acceptance. Nevertheless, Russell's idea that philosophy should concentrate solely on the small, individual problems before even considering the big problems gained wide acceptance and is still the standard for doing philosophy today. Unfortunately, there has not been much progress in solving the small problems.
Inventory of Philosophical Beliefs
There are other good reasons for trying to construct a metaphysical system besides the desire to reach a consensus of belief. One motive would be a desire to see what picture would emerge after examining all the widely accepted philosophical doctrines together. No doubt there would be disagreement over which doctrines should be widely accepted. General acceptance need not make a philosophical belief a true one. Nevertheless, even if the accepted beliefs proved later to be false, it would still be beneficial to assess their aggregate effect at the time. Looking at the big picture created by the total belief system could actually reveal weaknesses in the individual doctrines.
Even if one insists on a piecemeal, gradual approach, it would still seem beneficial to take inventory of those beliefs that have been established. Stepping back to examine their total effect could be beneficial. Tentatively building a metaphysical system on the foundation laid down by all the individual, established beliefs could do that. To fail to do this is like the architect who spends months designing specific rooms and features in a building but never takes any time to consider what the edifice is going to look like as a whole. A view of the entire project can reveal defects in the foundation that should be fixed before going any further. Even if no defects were found, it would seem that a periodic inspection of the project could help in the development of the best final production.
The idea of first solving small philosophical problems, e.g. the knowledge problem or the foundations of mathematics, before assessing the big picture can be called a bottom-up approach. This piecemeal approach amounts to a subject-by-subject advance. For some time, it has been the practice to divide philosophy into different subject areas and concentrate on studying those areas. For centuries, there have been the traditional areas of metaphysics, epistemology, ethics, and logic. More recently, new areas have arisen such as aesthetics, philosophy of science, philosophy of mathematics, philosophy of language, philosophy of religion, philosophy of history. Subcategories of these later appeared such as philosophy of physics, philosophy of biology, philosophy of economics, semantics, Christian philosophy, Hindu philosophy. More unusual categories have been formed such as philosophy of sports or philosophy of cinema.
This study of subject areas fits well with the idea that philosophy is actually analytic philosophy or the analysis of concepts. To do philosophy, according to this view, is to meticulously examine and evaluate either a traditional philosophical issue or a subject that is amenable to philosophical examination. The question then arises: what is it to engage specifically in the philosophical analysis of a subject? After all, physicists and economists engage in close analysis of ideas and concepts involved in their disciplines all the time. Continuing examination and reevaluation of general ideas, especially in the light of significant new information, has to be part of the study of a subject. A physicist reevaluates the concept of force in connection with recent information on the role subatomic particles play in the action of forces. An economist may have to take another look at the effect on monetary policy of the people's changing attitude toward their personal debt.
The difference between the philosophical approach and the regular approach is in the extent of the generality. The approach of philosophy is to examine the over-all purpose of a particular subject, its reason for existing, and its methodology--its means of accomplishing its aims. This is consistent with the popular use of phrases, such as "look at it philosophically" or "let's get philosophical." The phrases imply a stepping back to take a general view of a subject or endeavor. The idea of taking this wider view is to look at what one is trying to accomplish and to assess whether the means of achieving the aim are proving effective. The philosophical approach is not even simply an overview of the subject to assess its scope or extent. It tries to go deeper than that. It is a look into a purpose for engaging in the endeavor in the first place. Secondly, but very importantly, it looks into methodology in order to assess how well the purpose is being realized.
The question then is, even under a subject approach, why can't the subject to be studied philosophically be the universe as a whole, in other words, all of existence? If it is acceptable to analyze small segments of the universe, why is it not acceptable to study the nature and purpose of everything as a whole? As mentioned before, Russell had ambitions of tying together all the knowledge gained through philosophical analysis. Wilfrid Sellars seemed open to a comprehensive view of philosophy when he stated, "The aim of philosophy is to understand how things in the broadest possible sense of the term hang together in the broadest possible sense of the term," (Wilfrid Sellars, "Philosophy and the Scientific Image of Man," Robert Colodny, ed., Frontiers of Science and Philosophy (Pittsburgh, PA: University of Pittsburgh Press, 1962); reprinted in Science, Perception and Reality, (London, England: Routledge & Kegan Paul Ltd and New York, NY: The Humanities Press, 1963) 37; reissued (Atascadero, CA: Ridgeview Publishing Co., 1991).) Incidentally, Sellars and his father, Roy Wood Sellars, were 20th-century philosophers who apparently defied the trend and took more of a system approach to philosophy. David Armstrong is another exception. It appears, however, from the interests of most contemporary philosophers--especially the Anglo-Americans--that there is no longer any place in philosophical study for consideration of existence as a whole. One surmises this much from the published books and papers of professional philosophers since 1940.
The philosophical study of existence as a whole, as contrasted with the nonphilosophical study of the universe known as cosmology, needs to be considered seriously by those who insist on approaching philosophy through a subject-by-subject approach. The same standards of care and rigor can be applied to the comprehensive study of things as can be used in their piecemeal study. Lack of precision is surely what contemporary analytic philosophers fear since there has been such a long history of fuzziness in connection with metaphysical writing. The comprehensive study can perhaps be an aid in understanding the small areas, but even if it isn't, there is no reason for precluding the comprehensive study almost completely as has been done.
First Principles (The Top-Bottom Approach)
The search for a comprehensive picture is in tune with the ancient Greek idea of looking at philosophy as a search for the principle or principles behind nature or existence. It seems that early Greek philosophers were motivated by the idea of finding fundamental principles that would explain the universe. It may have been difficult for them to articulate exactly what they were seeking, but it appears they were thinking of principles from which all other facts could flow. Thales was the first philosopher to announce a principle, and it was actually an assertion in physics. He claimed that everything in the world was made of water. In today's scientific parlance, we would say that he was claiming that there was only one item from which everything else had been formed and that item was water. It is not clear that Thales meant only that. He may well have thought that his water idea would explain more than just a physical fact about the world. As in the case of most philosophers who came after Thales, his search for some ultimate explanation or meaning of the universe was important. The philosophers who immediately followed Thales also were intent on primarily finding the basic elements of nature, and for that reason, could be considered more physicists than philosophers. The line between the two was not clear.
Plato seems to have found a general explanatory principle, and it was based on his Ideas and particularly on the Idea of the Good. Aristotle was interested in finding principles behind the facts of nature (physis) in some of his writings. These writings were later collected by one of his followers and called meta ta physica (after the physics). From this came the word "metaphysics" which implies a study of what is behind physics or nature. In the past philosophy was divided into metaphysics, ethics, and logic. Logic has been a tool to aid in correct thinking, and ethics has shown at least some dependence on metaphysical doctrines.
Consequently, metaphysics has taken up a large space of philosophy. Metaphysics can be defined in a narrow sense as the analysis of concepts that need to be considered before undertaking the study of many other subjects in the universe. Traditionally, metaphysics has also included ideas concerning what has been considered the "ultimate" nature of the universe, such as the existence and nature of God or whatever other force may animate the universe. I will use this traditional meaning in this trilogy. It was understandable for Thales and philosophers that followed him to try to formulate a principle that might provide a full explanation for the nature of the universe. They had little knowledge of the physical world in comparison with what we know today, but they had observed enough to allow them to make a few assertions. As far as is known, the early Greek philosophers did not formulate any scientific laws like the ones we know today. They may not have even had a concept of scientific law, but they surely had noticed a number of regularities in nature.
One of the most obvious regularities to people at any period of human history are those recurring cycles that are seen throughout a year. Early humans observed these occurrences--the morning rises and evening settings of the sun. Both occur at approximately the same times of the day, but upon closer study, a gradual change in these times is found from one week to the next. Still, there is regularity in the daily changes so that it is known that the sun will rise and set at the same time on the same day in different years. For instance, on May 22nd of each year, the sun will rise at the same time and will set at the same time. The coldest part of the year will come during the days in which sunrise and sunset are closer to each other (the days are shorter). The hottest days will coincide with the longest periods of time between sunrise and sunset (the days are longer). Most plants will bloom after winter and before summer, i.e. in the spring, and give fruit in the autumn. Objects will always fall to the ground under a force called gravity.
Even those humans living many millennia before the preSocratic philosophers observed these and other patterns. From this, a desire must have arisen to find a common source of explanation. The desire was no doubt fueled by a natural curiosity exhibited in a wish to know simply for the sake of knowledge. There must have been an additional desire to find an original phenomenon or cause that had either created everything or at least had set it in motion. This originating phenomenon could provide an explanation for the patterns seen by the inhabitants of the earth. The originating phenomenon could be impersonal, but more than likely, primitive people imagined it to be like a human. This phenomenon would explain the patterns seen in nature. It would be easily assumed then--by primitives--that superior inventing minds had consciously designed the patterns.
The invention of myth then arose from that pervasive human desire to know something about the origins of things. Often the myths may not have made much sense as explanations, but it seems that once a mythical explanation became established not many people questioned it. That is until people like Thales came along. He apparently was not completely satisfied with the mythical explanations of his day and thought it more accurate that there would be a physical explanation for the nature of things. This was probably due to his close observation of physical phenomena. For instance, it is said that he predicted a solar eclipse in 585 B.C.E.
The bold step by Thales need not mean that he believed that nature was cold and completely impersonal. It appears that he and the other preSocratic philosophers still held some belief--even if only a weak one--about animistic forces in nature. Some of the preSocratics, like Thales and Anaximander, focused on physical phenomena like water and air as originating materials, but Anaximenes looked to something that was not physical--love and strife.
Then there was the concept of the nous, which was well known in Greek philosophy. It was inherited as a mythic/religious idea. The religion associated with Orpheus had a wide following and held a belief in the nous. The concept had an association with both the human individual and with the wider universe. On the individual level, nous referred to the mind apart from the body. It could also mean the soul, especially the rational soul. In a wider sense, it referred to a cosmic or divine mind that controlled the universe. Plato and Aristotle believed in both aspects of nous and wrote about it. Of course, there were probably different shades of meaning of nous understood by different philosophers. This is common in connection with any elusive concept as seen from the perspectives of different individuals.
A clear line between science and philosophy had probably not even occurred to the preSocratic philosophers. They saw their search as one for a principle that explained everything, not simply physical phenomena. They thought that such a principle could be found through thinking and reflecting on the nature of things rather than by a thorough and painstaking investigation and classification of the various parts and aspects of the world and the surrounding universe. Instead, a close consideration of the processes seen in the world would reveal the full picture of how it operated. This would then divulge its ultimate purpose and meaning. Aristotle made some observations of plants and for that reason could be seen as acting as a scientist, but his overall approach toward understanding is still clearly that of a philosopher. His speculation on the existence of a first cause, or Prime Mover as he called it, is that of a philosopher looking for general principles that explain widely.
Looking at it more closely, this top-down approach toward trying to find a complete explanation of the nature of the universe was a justifiable one on the part of the early philosophers. It could be worth the effort to try to understand the universe simply through discernment of a few basic principles that could be discovered through reflection on commonly observed matters. There were numerous relevant observations that could be made. Anaximenes' conjectures about love and strife as the motivating forces behind everything combined observations about the inanimate world and the animal world. It was a hypothesis which was worthy of consideration at the time and which was apparently considered seriously but simply could not stand up under scrutiny.
Given what the preSocratic philosophers knew, they could have discovered a principle, under their basic observational approach, that gave a credible explanation of everything and yet did not account for every single detail. In other words, an accurate sense of the meaning of the universe could have been obtained without, for example, knowing much about atoms. Of course, their understanding of the meaning of the universe would have been subject to change in the event of new discoveries.
Likewise, we today should be able to proceed to build a metaphysical system that would present an accurate picture of the meaning of the universe without having to wait until all the scientific details are established or all the individual philosophical problems are solved. This would mean that our assessment would not be an absolutely certain one. Every effort would be made to come as close as possible to a position of certainty both in the general principles announced and in the supporting details. Nevertheless, it would be perfectly acceptable to admit that we do not have complete knowledge about the universe; in fact we are probably far from having it. In other words, our knowledge would be defeasible, i.e. subject to defeat or change. It would be acceptable that our assessment of the meaning of the universe turned out to be erroneous and in need of revision. In other words any pronouncement on the meaning of the universe would not be a dogmatic and immutable one.
The Tone of the Past
Unfortunately, the tone of past metaphysical systems has been mostly dogmatic. Their authors have not given much indication that they were open to being wrong or that even the details behind their system could later prove to be mistaken. Writers like Plato, Spinoza, Kant, and Hegel seemed to assume that their pronouncements on the subject were the final word and that there was no room for possible later modification. This was no doubt a function of their times. Any person who wanted to appear credible on a significant subject had to convey a strong sense of authority and command of the subject. Any ambivalence of any kind would show that the writer did not have sufficient confidence in what he was proposing and would risk not being taken seriously.
In addition, there was the long-standing attitude in philosophy that a position must command certainty to be valid. A high degree of probability was not enough. This requirement of certainty would naturally make a philosopher more reluctant to reveal any sense of hesitation regarding his pronouncements. Today, people seem more willing to admit error than in the past. People seem more able to look at their mistakes with a sense of humor. When they find others have the same attitude about error, it further reinforces a person's willingness to openly admit errors. In fact, it is now the sign of an educated person to be able to acknowledge error. In the past, an educated person probably felt that to admit error could risk giving the impression that s/he was not so well educated after all.
A Grand Vision of Philosophy
Philosophers should not shrink from seeking a grand vision. The goal of the first philosophers was to gain a comprehensive understanding of rerum natura, the nature of things, and that can still be done. Even the thinker who tends to avoid looking at a large vista should try to understand the desire of some to seek a peek at the big picture. Such a restricted thinker could be of aid to the wider thinker by helping to keep the latter in line through appropriate criticism. In order to be able to furnish helpful criticism, the critical philosopher would benefit from trying the best to understand the impulse to seek the grand vision.
If nothing else, the delineation of a grand vision can provide psychological solace for some people. For a number of centuries, it appears that a large segment of human society has felt a need to fashion a view of the nature of the universe. Myth and religion have been the most popular means of providing this for the majority of people. Today religion continues to be an influential institution, and an interest in mythology has been renewed, especially after the writings of Joseph Campbell. Given that people are going to show curiosity about their origins and purposes, it would seem preferable that such myths and explanations be subjected to philosophical scrutiny. For this reason alone, it would seem that detractors of the synthetic or synoptic view would want to take an interest--if only to offer criticism.
Those who take a positive interest in attaining a grand view of existence have several sound reasons for making the attempt. The first is pure intellectual curiosity about knowing what is at the bottom of everything, what is at the foundation. This search for fundamental facts can also be approached on metaphysical grounds as seen in the debates over physicalism (materialism) and dualism. The search has a corresponding epistemological aspect based on beliefs.
Whichever of these two approaches is taken, there would appear to be a benefit of sorting out what the basic facts are. Sorting the facts can be more than just intellectually elegant. It can bring insights based on the facts we know, amplifying our understanding in ways we may not have imagined before. An example of the influence of fact on belief may be found in astrology. A believer in astrology could change his mind about its truth after realizing that the stars in the sky are too far away to exert any significant gravitational force on the earth. Another important consideration may be that the faint light that we see from the stars today left them many light-years ago. Then there is the observation by astronomers that the astrological maps are incorrect.
The need to establish foundational facts at the bottom of all existence is based on intellectual curiosity, but it has to be more than that. Questions about the foundation of existence involve the following: What is the meaning of life? What is the origin of the universe? Is there an "afterlife"? What will happen to me if there is an afterlife? Most people who have thought of these questions, have wanted to know definitive answers to them, and have come up with their own answers. It is true that the vast majority has not thought its answers through very carefully and has instead adopted answers that have been passed onto them by their families or their cultures.
Nevertheless, the questions are of universal interest, and people take them seriously. If they sometimes seem to treat them lightly, there could be several reasons. For one, they could realize that the answers they have come up with are not incontrovertible ones and that they are open to well founded criticism. They could feel frustrated with not being able to find definitive and fully satisfying answers to those questions and thus may act more as if the questions are a nuisance. They could perhaps feel vulnerable in even having to consider those questions, and so they discuss them in a seemingly frivolous manner. Finally, they could feel uncomfortable discussing their views with people who could have widely different views from their own.
In spite of people not appearing to take a deep and continuing interest in these questions, issues of mortality appear to become more pressing after people reach middle age. This is understandable since it is about that time that more signs of physical infirmity appear. People may also realize that the day of their death is getting closer. It is a common observation that older people go to church in larger percentages than other age groups. By contrast, young people--say those under 25--are filled with a feeling of invincibility, and contemplation on death is far from their mind. Apart from how much people may think about these ultimate questions, some are in fact important ones that reach into the very core of our lives. It is certainly important to investigate what consequences our actions may have beyond the obvious immediate effects.
John thinks about stealing $100 from the cash register where he works. There are several consequences that can result if he is caught. The most serious is that he could suffer divine punishment, both here and in the hereafter. Most of the world's religions teach of divine retribution in some form, so John may decide to take that into account. People are tempted every day to engage in acts which could be considered immoral or sinful and thus subject to divine punishment, so it would seem advisable to know as closely as possible whether divine punishment actually exists.
Other ultimate questions involve our destiny. A big question is whether we survive this life. Whether we have free will is also important for our destiny. The desire to survive into another life, or even better, to become immortal has been called egotistical, but it need not be so. The desire to live on can be based on a simple love of life. If a person enjoys being alive, it is understandable that s/he would want it to continue indefinitely. It is actually hard to understand how someone who is happy in life would not wish to extend that enjoyment if at all possible. It would also seem understandable that someone who had established cherished relationships on this earth, either with family or with friends, would want to continue to be able to enjoy their company and comfort without end. Even if there had to be interruptions in seeing those who were close to us, even long interruptions, it would still be preferable to be able to see them periodically rather than suffer the permanent separation caused by death.
Philosophy should not be afraid to reach for the grand vision in seeking answers to ultimate questions of life, death, and destiny. It has a long history of trying to understand what is at the basis of existence, and it should not stop short of trying to answer those questions. If any area of intellectual endeavor is well equipped for that particular task, it is philosophy.
The Romantic Era's System: Idealism
The movement known as German Idealism was begun by Kant when he posited a distinction between the phenomenal world of objects and a transcendent ding-an-sich, or thing-in-itself, also known as the noumenal world. The world of phenomena was supposed to be a world that we perceive everyday but behind them there is something else--the ding-an-sich. It is not only not visible, it is also not knowable, but it is there.
Kant propounded the idea of a transcendent reality in an attempt to come up with answers to problems David Hume had uncovered about our ability to gain reliable knowledge of the natural world. Kant thought the root of the epistemological problem is in our imperfect sense perceptions. He believed that we do have the ability to perceive the ideas of space, time, and the categories of the understanding that in turn allows us to gain sound knowledge of the phenomenal world.
This ability was based on our transcendental self, the component in us that allows us to gain information. Our transcendental selves apparently have contact with transcendental reality and are thus able to gain sound knowledge of phenomenal reality. These transcendental selves are not part of the natural world but are ideal, or spiritual. You can say these transcendental selves are our souls. The term transcendental Idealism for this aspect of Kant's philosophy comes from this. Kant did not try to explain the nature of either transcendental reality or transcendental selves. One then has to ask how he came to know of their existence. While they may have seemed useful to Kant to avoid Hume's skepticism about the phenomenal world, it does not follow that they in fact exist.
These ideas were most fully developed in The Critique of Pure Reason, one of the best known classics of Western philosophy as well as one of the most turbidly written of all literary works. Kant could write clearly as exhibited in works such as Prolegomena to Any Future Metaphysics, which was intended to lay the groundwork for The Critique of Pure Reason. While Kant clearly indicated that nothing could be known about the transcendent ding-an-sich, his Idealist successors had no such reservations and proceeded to give their own accounts of the nature of the transcendental realm. They did not seem inclined to put a tight reign on their imagination, even in connection with such a mysterious area.
Johan Gottlieb Fichte actually visited Kant to share his ideas on extending Idealism. Fichte tried to overcome Kant's dualism of phenomena and noumena by positing an absolute mind, or ego, which constituted all existence. Furthermore, that absolute mind was moral reason. This absolute ego is divided into numerous relative egos that are the minds of humanity. The human mind is a manifestation of the absolute ego, which moves progressively through history to a final destiny by means of the relative egos. Areas of human experience such as ethics, religion, and aesthetics in their ongoing evolution are part of the absolute ego.
Friedrich Schelling accepted much of Fichte's conception of the absolute ego, or Absolute (they spelled it with a capital "a") but wanted to have a clearer picture of nature. While Schelling did not attribute consciousness to nature, he did present it as a pantheistic system of spiritual forces similar to the monads of Leibniz. Supposedly, the monads were immaterial souls that made up the universe. The Absolute sits in self-contemplation reminiscent of Aristotle's Prime Mover.
Friedrich Schleiermacher was the most religious of the philosophers who constructed Idealist systems. He influenced others to move toward a more religious orientation of metaphysical Idealism. Fichte and Schelling modified their views to make room for religious experience in human life. Fichte came to see the progression toward a civilized state as one in which religious faith is paramount partly because of its positive influence on ethical conduct. Schelling also felt a need to modify his system. Like Fichte's, it had been too formal and abstract to provide for actual human experience. Schelling now saw the phenomenal world working its way back to God. This movement proceeded through a religious process culminating in the Christian union of God with man.
Georg Wilhelm Friedrich Hegel saw a gradual, progressive development in the consciousness of humanity taking place through history in a dialectical manner. In the process, the Absolute lifts itself up from mere possibility and apparently does it through human experience. The Absolute is the same as God, except not personally involved with humans. The entire process is a spiritual one for which religion and ethics are important.
In Britain, Idealism gained acceptance later through the writings of such men as T.H. Green and Edward Caird followed by Bernard Bosanquet, J.M.E. McTaggart, and F.H. Bradley. All of them had a closer affinity to Hegel than to any other German Idealist, but as with many other neo-Hegelians, each felt free to deviate from the master's lead and built his own Idealist system. This was understandable since so much of what Hegel wrote was appallingly confusing and thus open to any number of conflicting interpretations. This is not to say that the other Idealists wrote clearly. After all, it was not easy with the burden of having to explain such elusive, mysterious, and ethereal concepts as the thing-in-itself, universal consciousness, dialectical progression, and the Absolute. The approach was often vague, unsubstantiated, fantastical, and outright illogical. The interdependence of different concepts was sometimes strained since it was done to make the different parts cohere tightly with one another when that simply could not be done.
With all this conceptual confusion, it is not surprising that there was eventually a revolt against Idealist thought. One thing that must be asked is that if the Idealists could claim to understand transcendental reality, how could it be that they came up with such a varying array of conceptions?
Revolt against Idealism
The first to rebel against the romantic tone of Idealism at the time was Arthur Schopenhauer even though his system was an Idealist one based on reference to a thing-in-itself. However, his portrait of the underlying reality behind the phenomenal appearance was in stark contrast to the other Idealists. His underlying thing-in-itself was a World Will that was blind, impulsive, did not follow a progressive course, and did not seem concerned with human edification or welfare. The only capability within human power was to quiet that driving urge. In this, Schopenhauer's ideas were in consonance with those of Buddhism, which was just then being introduced to the West. He, in effect, turned the Absolute of Fichte and Hegel on its head. He disliked Hegel and went so far as to call him a charlatan. As a result of his dissent, he failed to land a job in academe and was labeled the philosopher of pessimism.
Two others in the 1800's who attacked Idealist systems, particularly Hegel's, were Soren Kierkegaard and Friedrich Nietzsche. Kierkegaard rejected Hegel's system as being too rigid and sterile. He desired to see a greater importance given to emotion in human life and a place for a less rationalized Christian faith. (Perhaps Kierkegaard's emphasis on emotion can be at least partially explained by the high likelihood that he was a manic-depressive.) Nietzsche also rebelled against the extremely formal nature of Idealism but went in a very different direction from Kierkegaard in regard to religious faith. He was a strong critic of Christianity.
About the same time, a single individual began another movement with a definite agenda in mind of discrediting not only Idealism but also metaphysics in general. The movement was called positivism, and its moving force was Auguste Comte. His contention was that metaphysics had been useful to people at one point to give an explanation of the world, but that with the growing success of science, it had outlived its usefulness. By metaphysics, Comte meant the study common in the 19th century of a transcendent, supersensible, spiritual reality. Science, to him, was a positive and direct approach to obtaining knowledge in comparison with metaphysics and before it, myth.
New Trends
With all this opposition to it in the 1800's, Idealist metaphysics still had to contend with new opposition at the dawn of the 20th century. As mentioned before, G.E. Moore and Bertrand Russell mounted an attack on Idealism although both had previously been faithful adherents. Moore wrote "Refutation of Idealism" in 1903 but shied away from trying to construct an alternative metaphysical system. Russell attacked Idealism by discrediting Hegel's logic and arguing against Bradley's ideas on internal relations.
Russell later came up with his own nonIdealist metaphysical system which he labeled Logical Atomism. As J.O. Urmson wrote in 1956, "[A]s presented in the documents of its heyday, logical atomism is one of the most thorough-going metaphysical systems yet elaborated." (J.O. Urmson, Philosophical Analysis (Oxford University Press, 1956) 4.) Russell said he was inspired to think of developing Logical Atomism in the course of his thinking about the philosophy of mathematics. He certainly had plenty of time to think about the philosophy of mathematics during his writing (along with Alfred North Whitehead) of Principia Mathematica in which he tried to establish the foundation of mathematics in logic. (While Russell never expressly wrote down a comprehensive metaphysical system covering such subjects as ethics and aesthetics, a complete study of his pronouncements on a variety of topics would likely reveal a coherent metaphysical system. He did say, at one point, that it had been his intention to write first about mathematics and the sciences, then to write about the social sciences, and finally to put it all together.)
Russell's idea for the metaphysics of Logical Atomism was that it would be based on a perfect language that would itself be an outgrowth of Principia Mathematica. The language would be built on atomic facts that would form elementary propositions into which everything that needed to be said could be broken down. Since the language would be a perfect one, false propositions would be eliminated through logical techniques. Ultimately, the language would be a perfect mirror of the world, and it would be possible to gain a full understanding of the world through it. Based on Russell's initial pronouncements on the subject, Wittgenstein wrote his Tractatus Logico-Philosophicus, a more fully developed account. A number of philosophers also tried to develop it. Rudolf Carnap, the most active writer of the Vienna Circle of Logical Positivists, in 1928 wrote The Logical Structure of the World, which title at least seemed inspired by Logical Atomist ideas. Eventually Logical Atomism was abandoned by its own creators. Wittgenstein repudiated the Tractatus in later years.
Logical Atomism's failure as a metaphysical system may be understandable in that it was trying to build on a logical foundation, and it is very hard to see how one can possibly establish the physical world solely on logic. Logical Atomism was an abstract system of knowledge. How can an abstraction be a foundation for the physical world? Perhaps Russell and others were misled by the enormous success of mathematics in helping to understand physical science. They perhaps thought that in a similar fashion logic in association with a perfect language would be able to explain the entire world.
The members of the Vienna Circle, who started meeting in 1922, studied the Tractatus very closely. It expressed doubt about the validity of metaphysics. Wittgenstein pointed out that sentences had to be verifiable, or else it had to be said that they were nonsense. By nonsense, he didn't mean that such statements were silly. He meant that since they were not verifiable they contained no literal sense and thus need not even be considered for discussion. He pointed this out but did not elaborate. The Logical Positivists, however, readily took up the idea, and it later became the centerpiece of their movement, the principle of verifiability. They discussed and wrote about verifiability extensively. Through its use, they hoped to eliminate metaphysics by showing that metaphysical assertions, such as "the world consists of ideas" as Idealists claimed, were devoid of meaning because their proponents could not come up with any method of verifying them. Unfortunately, the Logical Positivists could never soundly establish the principle. Several formulations were attempted, including a weak and a strong version, but none was found without defect.
The Logical Positivists themselves acknowledged shortcomings in the principle. For one thing, it was not clear that the verifiability criterion itself was acceptable under its own standard of what sentences were cognitively meaningful. Consequently, there was no rule established that could conclusively banish metaphysical pronouncements as automatically meaningless, but the idea that philosophy should observe basic standards of rigor was reinforced. From ancient times, there had always been a standard in philosophy that required that claims be based on at least a minimal amount of justification or verification. The Logical Positivists tried to formulate a simple rule for verification. Their failure did not excuse the need for justification; it strengthened awareness that adequate justification was necessary.
Russell and the Logical Positivists were either scientists or were scientifically inclined. Among them, Rudolf Carnap went farthest in writing books and articles to try to find an ideal language for science, one which would provide the smoothest avenue for scientific investigation. Many of the Logical Positivists were not so much interested in trying to reconcile varying metaphysical beliefs, as with trying to totally preclude their serious consideration. Any endeavor to consider metaphysical beliefs related to the meaning of the universe as a whole appeared to them as a waste of time. Although the Logical Positivists were able to clarify some of the issues involved in the communication of scientific ideas, they were not able to come up with a perfect language for science. Too many issues arose involving the philosophy of language itself.
The Logical Positivists not only disapproved of the turbid writing of the Idealists, they appeared to despise it. (This distaste could have been based on their having had to read and show respect for Hegel as students.) Take Hans Reichenbach, the founder of the Berlin Circle of Logical Positivists. In his 1951 book, The Rise of Scientific Philosophy, on the very first page he questioned what a quote from a famous philosopher could mean.
Reason is substance, as well as infinite power, its own infinite material underlying all the natural and spiritual life; as also the infinite form, that which sets the material in motion. Reason is the substance from which all things derive their being. (Hans Reichenbach, The Rise of Scientific Philosophy (Berkeley, CA: University of California Press, 1951) 3.)
Reichenbach pointed out the varied meaning that the passage could evoke from a reader would eventually make him give up and throw away the book in which it was found. The passage was written by Hegel. It may have been writing like this and criticism of it that caused people to gradually move away from Idealistic metaphysics more than any substantive criticism.
Metaphysics Discredited
After the aforementioned attacks, metaphysics, through its identification with Idealism, was left highly discredited. It is no surprise that philosophers have not shown an interest in proposing any new metaphysical systems. Neither has Continental philosophy engaged in producing metaphysical systems, although it has criticized the overtly minute approach of Anglo-American philosophy. Existentialism, it is widely agreed, is hard to even define because there are a number of disparate ideas that seem to fall under the rubric. Continental philosophers have also taken an interest in special areas such as deconstruction, semiotics, Marxism, and cultural studies, but no system tying all these together has appeared. Idealism did have defenders well into the 20th century such as William Ernest Hocking and Brand Blanshard. Nor have many philosophers tried to work out a consistent system based on the rival school of materialism, more recently called physicalism. Yet, Carnap himself allowed for the building of a metaphysical system, at least as he defined it.
I do not include in metaphysics those theories--sometimes called metaphysical--whose object is to arrange the most general statements of the various systems of scientific knowledge in a well-ordered system; such theories belong actually to the field of empirical science, not of philosophy, however daring they may be.(Rudolf Carnap, Philosophy and Logical Syntax, (London: Kegan Paul, Trench, Trubner & Co., 1935), Part I, reprinted in 20th Century Philosophy: The Analytic Tradition, Morris Weitz, editor (New York: The Free Press, 1966) 207.)
Of course, one can disagree with Carnap on what is to count as metaphysical. If metaphysics is the study of what exists, there is no reason why an empirical statement about the existence of an object cannot also be a metaphysical statement. Three paragraphs after the quoted passage, Carnap tried to distinguish between what he considered two different concepts of reality, one composed of empirical statements and the other of philosophical statements. He recognized as empirical the statement by a zoologist asserting the reality of kangaroos and pointed out that both the realist--who today would more likely be called a physicalist--and the Idealist would recognize it as true. He then claimed that where both the realist and the Idealist went wrong was in going on to talk of the reality of the physical world as a whole.
Carnap was unfair to the realist (physicalist) on this point. Most realists accept the existence of the physical world as an empirical proposition but are also interested in defending that proposition against attack from the Idealists. It is not their aim--in contrast to the Idealists--to uphold any propositions beyond the simple empirical proposition that the physical world exists apart from any perception of it. If Carnap was accusing the realists of improperly delving into metaphysics merely by entering into debate over the issue, then they must stand so accused. Carnap's opprobrium should have been aimed at the Idealists whose practice had been to undermine the acceptance of physical reality and to posit a separate reality over and above the physical world.
Well-Founded Metaphysics
The Logical Positivists were physicalists or realists no matter how much they may have wished to stay above the metaphysical fray through the use of their cherished principle of verifiability. Anyone claiming, as they did, that objects exist in a physical world in a system of space and time and nothing more has to be classified as a physicalist. In fact, Otto Neurath, fellow member of the Vienna Circle, convinced Carnap to adopt a physicalist basis by 1932 for his analysis of scientific language. Carnap became progressively more flexible in his ontological views, (See "Empiricism, Semantics, and Ontology," Revue Internationale de Philosophie, p. 11 (1950), reprinted in Semantics and the Philosophy of Language, Leonard Linsky, ed. (Chicago: University of Illinois Press, 1952) 207) although he insisted throughout the rest of his career that metaphysics was a meaningless pursuit.
It may be possible to build "a well-ordered system" as Carnap suggested based on empirical data as long as some accommodation is made for introspective observations that are checked by intersubjective comparisons with the introspective observations of other people. Perhaps introspection could be counted as a sixth sense for the purpose of philosophical understanding.
While the rejection of grand metaphysical systems has had a salutary effect, there is nevertheless a need for a comprehensive and systematic compendium of well-founded, rational beliefs about the universe. Such a study would in effect be an attempt to find the meaning or purpose of the universe, if any. It would not involve a study of the universe in all its detail. That is left to the sciences, starting with physics and continuing with chemistry, biology, and all the rest. Cosmology is a science that makes a study of the origins of the universe but also confines its approach to a narrow examination based on the more basic physical sciences--physics, chemistry, astronomy, and geology.
Saying that it is desirable to construct a comprehensive metaphysical system need not mean it has to be written in "muddle-headed" style. In contrast to the old systems, a metaphysical system can be one that is (1) clearly written, (2) founded on logical arguments, and (3) based on well-established facts and well-founded beliefs. A valid metaphysical system need not have an answer to every question, as was once assumed. That assumption was another reason system builders sometimes engaged in logic chopping and concept stretching. That way they apparently assumed that it could appear that every question was correctly answered and everything fit together perfectly.
A 21st-century system can go as far as possible to base its doctrines on currently established fact but also to point out instances in which the available information is not so reliable. In spite of these limitations, it can proceed because it need not prove all of its propositions to a point of certainty. It can instead be satisfied to found its propositions on what is the most probable case with regard to any given issue. It may even at times have to choose one belief over another because it is simply the one that is more probable than the other.
This approach is in tune with the less authoritarian, more modest attitude. A wider intellectual modesty has perhaps come as a result of the continual appearance, for more than a century now, of new scientific and technological breakthroughs that have too often been the cause of embarrassment to those who had assumed that nature was static or that humans were not capable of uncovering it. Examples are earlier doubts about how wide the applications of the internal combustion engine could become or about the extent to which human-made flying machines could be developed. Today a philosopher can try the best to present theories and doctrines that are grounded on the most solid foundation given the contemporary state of knowledge but still be cognizant that new discoveries can change the parameters that have seemed the most acceptable. Alternate paths can also be discussed and considered.
A Prison of Certainty
Philosophers also need to rethink an admirable goal of philosophy: to try to reach the level of complete certainty in all its assertions. There is no doubt that philosophy should have high standards of rigor and exactitude in its search for the truth. Perhaps it should in a sense be "uncompromising," but that word has to be used in a way that takes account of human limitations in getting at the truth. It may be good to say that one is not going to compromise on the truth for the sake of expediency or for the sake of not offending sensitive people. It is another thing to insist that one cannot make a rational, well-founded assessment that a proposition is true unless one is certain on the matter.
Part of the source of this unbending devotion to certainty has been the insistence by many philosophers since Plato that philosophy has a particular method for gaining knowledge that other fields, like science, do not have. Philosophers who have made this claim have been labeled rationalists for their belief that they can gain knowledge simply through the efforts of reason. Furthermore, they have proposed that the knowledge they can gain is a certain knowledge that is untainted by errors to which acquisition of data by the senses is prone. Plato proposed that one could gain this supersensible knowledge through his Ideas. Kant thought it could be done through his synthetic a priori statements that are neither acquired through the senses nor solely through logic.
Yet, uncertain but highly probable statements are accepted not only in everyday life but even in scientific endeavors, which seek a high degree of certitude. Atoms and their constituent particles are discussed even though physicists are far from certain in regard to what an atom looks like. Gravity is accepted and measured in spite of questions about its exact nature and about how it can act at a distance. These and many other propositions and concepts are accepted and used with full awareness that there is no certainty as to their exact nature.
In philosophy, there have been a number of assertions that could be made with a high degree of confidence but have still not been maintained because of their lack of certainty. Instead, these assertions have caused a tremendous amount of consternation in the history of philosophy. The most prominent example that comes to mind is that of doubt over the existence of everything around us. Descartes, in the early 1600's, questioned the existence of everything around him as well as himself. He did this for the purpose of setting his knowledge on a foundation of total certainty. (Augustine had actually been first, in the fourth century, to observe that his awareness of his own thinking made it clear that he existed.)
Descartes' simple rationale for believing in the existence of the objects around him was that they were clearly and distinctly present and that he did not believe that God would allow him to be deceived. This justification for believing in the existence of external objects satisfied many people in addition to Descartes, but there were others who were not so easily convinced. Descartes' ruminations on the issue did succeed in starting a controversy that is still rumbling today although not with the intensity that it once had.
Myriad attempts were made to establish that physical objects existed as well as the opposing proposition that they did not exist. The controversy has gone on because philosophers have continued to search for certainty behind the belief in physical objects and have not been able to do so. The related problem of doubt about the existence of other minds is another one that continues to be controversial because of the insistence on certainty. Still another certainty problem involves the definition of knowledge itself.
While the quest for certainty need not be given up completely, there is no reason philosophy cannot make significant, permanent gains on the basis of a simple high level of evidentiary justification for beliefs. We cannot be absolutely certain that the moon exists or that water will always turn into ice. After all, the silvery orb we have been observing on some nights for millennia and have known as the moon could simply be an optical illusion. The flights that were supposedly made by men to the moon around 1970 could have been part of a well-orchestrated conspiracy. (There are people who have seriously made this claim.)
The conspiracy could have been formed for any one of a number of reasons. It could have been a plan by the U.S. government to intimidate and humiliate the Soviet Union, or it could have been the idea of a secret global society in control of both countries that had some unknown reason for perpetrating the hoax. As for the formation of ice, there is no guarantee that just because water has turned to ice for countless millennia that it will do so again tomorrow. (Hume pointed out this lack of a guarantee that an effect would always follow a particular cause in his idea of "constant conjunction" for characterizing the cause and effect relationship.)
Countless other examples like these could be offered of facts for which there is little room for real doubt but that cannot ultimately be known with absolute certainty. Nevertheless, there are numerous facts which everyone believes to be true without an inkling of doubt. Nor are those the types of facts that people might assume simply because they did not take much time to reflect on the matter. There are many hard-to-doubt beliefs that even the most cautious and exacting philosophers, after close and thorough analysis, would find hard to sincerely disbelieve. Examples of universally accepted facts are that objects fall to the ground, water flows, a sun exists near the earth, lights called stars can be seen above the earth at night, a person will bleed after suffering a severe cut, and a creature without eyes cannot see.
Many of these facts are found universally throughout the world and are fundamental to human life as we know it. If we couldn't rely on a number of facts remaining as they are from one day to the next, our lives would be much more difficult. Those facts are reliable and repetitive, and yet we can't be absolutely certain that things are as they appear to be. For instance, how does any one person gain assurance that the sun is spherical? It looks very much like a two-dimensional disk.
We can gather near certain facts and obtain at least some idea of how they fit together. From there, we can proceed to analyze other supposed facts that are less certain. We can weigh the reasons for and against accepting this more doubtful group of facts as true. After we have done that, we can go on to inspect and hopefully be able to decide on the truth of succeeding levels of less obvious facts. After completing our analysis, we can see if we can form a coherent, comprehensive picture based on all the facts. It is possible that we would not be able to agree that a single, comprehensive picture or system could be formed, but then perhaps the mass of facts could be seen as forming two or three possible systems. Ultimately, it could be discovered that no coherent system at all could be formed, that the totality of facts was simply too jumbled to present any "big picture."
Metaphysical Study and Modest Gains
Even the discovery of this latter result would be of benefit. Based on the available evidence, it would indicate that to try to formulate any kind of metaphysical system would be a dead end. It would validate the rejection by many philosophers in the 20th century of all metaphysical schemes. It would perhaps give greater ease of mind to philosophers in the future to simply concentrate on the individual problems of philosophy. Perhaps most importantly, it would help prevent people from being misled by charlatans who claimed to have discovered a new metaphysical system.
On the other hand, a sound metaphysical system could be discovered. It could turn out to be the only legitimate system that could be supported by the facts. Alternatively, it could more modestly be the most acceptable one among other plausible ones. There would be a number of advantages in having one predominant, factually based metaphysical system. As in the case where no metaphysical system was found legitimate, it would help to discredit falsely based systems. Any proposed system could be compared side-by-side with the legitimate one to see where it could have gone wrong.
The greatest aid in having a single metaphysical system would hopefully be in the greater intellectual harmony, at least among philosophers and other thinkers. Perhaps, this greater unity could even spread to the population at large. There could even be great benefit to the world's society from everyone reading on the same page. There is greater social cohesion and harmony when the members of a society share a common outlook and values. This is understandable since there is less friction and less time spent on trying to understand and reconcile disparate viewpoints. In such a society, individuals do not have to accept or adopt mores or laws based on the values or ideas of others that are alien or even objectionable to their own way of thinking. Instead, a common ground of values and morals eases the reaching of a consensus on any particular issue, with the only grounds for contention being how to apply commonly held values to a particular situation.
With the arrival of multiculturalism, all this may sound reactionary and provincial, but it need not be so. A metaphysical, and consequently a moral, consensus need not mean that it would be reached in an authoritarian or unthinking manner. A consensus would be based only on facts, and most of those facts would be either readily ascertained or at least noncontroversial to reasonable persons. It would not be forced on anyone either by a legal system or by a social atmosphere that made it uncomfortable for individuals to disagree, such as has happened in past societies especially before the establishment of democracies.
The consensus metaphysical system would have wide assent because it would be based on solid evidence. There would be no need for coercion for it to be accepted. Besides, it would be based on free and open inquiry into the facts that compose the world and not on any preordained agenda to achieve a particular social purpose. There would still be room for dissent in a society that would adopt the system. Presumably, there would not be many rational dissenters since the truth supporting the system would be obvious.
Analytic philosophy came to mean linguistic analysis; yet there were misgivings. Gilbert Ryle in his famous article, "Systematically Misleading Expressions" observed that the function of philosophy was to expose linguistic statements that were improperly expressed and rephrase them in a form that brought out the correct meaning of the statement. He added,
And I am for the present inclined to believe that this is the sole and whole function of philosophy . . . But as confession is good for the soul, I must admit that I do not very much relish the conclusions to which these conclusions point. I would rather allot to philosophy a sublimer task than the detection of the sources in linguistic idioms of recurrent misconstructions and absurd theories.(Proceedings of the Aristotelian Society, 1931-1932, quoted in Philosophical Analysis 165.)
No, Professor Ryle, philosophy does not have to be so limited.
The Metaphysics of the People
While philosophers have not spent much time on metaphysical systems since 1950, there have been others who have remained very busy promoting their cherished metaphysical systems. While these others have not put forward much that is new in the area of metaphysics, they have continued to advance and refine systems that have been in place for thousands of years in some cases. These metaphysical systems are the ones put forward by the different religions of the world. Schopenhauer said that religion is the metaphysics of the people. There are any number of people who act as the metaphysicians (metaphysicists?) of religion: ministers, priests, theology professors, religious philosophers, and anyone else who can attract a large enough following for their teachings.
As is done in metaphysical systems, religion posits a set of beliefs that it claims are a comprehensive and coordinated explanation of the world and which gives guidance to humans on how they are to lead their lives. There are also related ideas of what happens to people after they die, and there is the assumption that people are capable of making choices under a capacity called free will.
There is also the very important teaching that there is an entity (or entities) that runs the universe, determining its nature and destiny. The entity is usually considered to be transcendent, outside of space and time, and is exempt from all physical laws. It is also usually thought that this entity created the universe. Sometimes the entity is the universe itself and so is not transcendent. These are the pantheistic religions. The entity is generally referred to as God and can resemble humans in characteristics to a great extent. For instance, God is often pictured as having emotions such as anger, joy, and even regret. He takes an interest in humanity and its ethics.
Philosophy has shown an interest in investigating these same ideas. Here are just a few examples. Several preSocratic philosophers believed the nous was the mind in control of the universe. The Pythagoreans were considered philosophers but were perhaps more of a religious cult, as shown by a number of rituals they observed. Plato, who was something of an unofficial Pythagorean, talked about a God who seemed to be related to Plato's idea of the Good. During the Middle Ages, philosophy and religion were considered by both Jews and Christians to be closely related. Christian scholars called philosophy the handmaiden of theology.
Descartes found the existence of God during his ruminations about what could be certain. Kant reviewed the traditional proofs of the existence of God and showed them to be inadequate but nevertheless posited a God for the sake of the enforcement of human ethics. The Idealists presented the notion of the Absolute as their concept of God and built elaborate metaphysical structures on that foundation. Many of them remained Christians, although they probably could not be considered orthodox.
While it is true that before the 20th century there was a close association between philosophy and theology, there has been a difference in approach. The difference goes back to the very founding of philosophy at the time of Thales. Philosophy was born when, in contrast with myth and religion, it began to determine facts about the universe on the basis of close observation and thought. Myth and religion had great credibility and power in determining what people should believe to be the true facts about the universe. Myth based its belief on tales that had been passed down by storytellers such as Homer and had been accepted by tradition as giving sound explanations of events in the world. Religions also depended on ancient tales but in addition relied on social and sometimes governmental authority that demanded that certain religious conventions to be observed. For centuries, few people challenged myth and religion as vessels of the truth.
Today ignorance and prejudiced belief continue to be based on unfounded allegations and on dogmas which have no more than tradition and fear to support them. Religious leaders promise success in life, teach people to disparage well-founded scientific facts, and lead followers to commit violence and bloodshed in the name of their gods. Religious faithful sometimes take harmful stances, either to others or to themselves, such as discriminating against those with different beliefs, attacking those whom they consider sinful such as homosexuals, and refusing some forms of medical treatment for themselves or their children.
Analytic philosophy has at times examined and criticized these pernicious tendencies observed in some religious believers; however, there has not been enough criticism. Perhaps if there had been more criticism, unenlightened trends would not have taken the hold that they have. Religions offer a grand vision to their converts and potential converts based on faith in the words from men in the past and in prophecies of what is to come in the future. On the constructive side, philosophy needs to investigate these grand visions through a system that is based on the best evidence and on rational judgment.
It is my intention in this trilogy, The Meaning of the Universe, to construct a contemporary metaphysical system that will try to present a picture of the significance of sentient beings in the universe based on the evidence available at this time. The system will address salient issues in philosophy, weigh the plausibility of different resolutions to the issues, and try to choose the best resolution. Every effort will be taken to make choices based on the best available evidence rather than on venerated tradition or on outcomes that make people feel comfortable.
This book will not delve deeply into epistemology, the theory of knowledge. Perhaps it should. After all, how can any assertions be made here without first assessing how statements can be known? The decision was made not to deal with epistemology here because it would have made the book too long. The statements in this book will simply be assumed as correct especially since they deal to a great extent with less controversial observations of the world. Epistemology will be studied in Book 2. That will hopefully clarify knowledge questions that may come up in this book.
The approach will be empiricist; that is, significant trust will be placed on what the senses tell us either directly or indirectly. From that, it follows that great weight will be put on the information provided by science. This will be done in full recognition that scientific findings and theories are not fixed, dogmatic pronouncements. They are open to revision as scientists continually investigate and analyze the information in their fields. There are often a number of competitive theories due to the ongoing accumulation of data and to the understandable disagreement among individual scientists on the interpretation of the data.
Another important point is that science many times deals in probabilities. On account of this lack of complete certainty, what was first assumed to be true may turn out not to be so. A well-known use of probability is made in the area of quantum mechanics in physics where the inner workings of the atom are studied. The social sciences make great use of probability. Philosophy also has recently revised its emphasis on accepting only infallible results and has begun to accept the idea of "inference to the best explanation." (Gilbert Harman was the philosopher who first used that phrase in 1965.)
The foundational approach will be tried with the system being built by starting with the most basic and reliable facts and proceeding from those to the next level of more complex facts. The idea behind foundationalism is that by using this stairway of sound facts one can build an impressive edifice of knowledge for understanding the world as well as our own lives. It will be interesting to see how far we get in building this edifice of knowledge. The type of foundationalism to be followed is the modest kind, meaning that the basic facts need not possess certainty and need not perfectly (deductively) support the second level of facts. They only need to support justification of the second level of beliefs.
Rene Descartes is still the best known exponent of foundationalism. He first announced his new approach in his essay "A Discourse on Method." (Rene Descartes, "A Discourse on Method," reprinted in The Rationalists (New York: Dolphin Books, 1960) 35.) He was confident that it could clear confusion and lead to certainty about facts. Descartes estimated that the sciences had not been able to reach the same level of certainty because they had not used the deductive approach of mathematics. Once the sciences used the same deductive foundational method, they would be able to enjoy the same level of certainty. Presumably, the same method could be used to ascertain simpler, nonscience related facts.
Descartes was correct in pointing out the highly reliable method of deduction in mathematics. However, we have since discovered that the facts of the world do not lend themselves to revelation by a strict deductive approach. The approach to understanding them is called an inductive one. The strict deductive method only applies to mathematics and formal logic. Unfortunately, faith in a strict deductive method continued to push philosophers to seek absolute certainty. Descartes envisioned a strict deductive method that has been labeled radical foundationalism. A moderate form of foundationalism does not require that foundational beliefs possess certainty or that they deductively support all the overlying beliefs.
My system will be primarily what could be called an analytic metaphysical one. No, it will not delve for pages into linguistic analysis of sentences but will try to be clear in the words and sentences used in the discussion. Hazy concepts will not be discussed unless they are unavoidably important. The nature of far away space and quantum mechanics come to mind as examples of unclear, confusing subjects that need to be considered. Only concepts that have been formulated on the basis of close observation and carefully gathered evidence will be relied upon. While the proposed system will be analytic in the sense of trying to be as rigorous and clear as possible, it will also be synthetic. After analyzing the significant available knowledge of the universe, it will be synthesized to give the clearest possible picture of the meaning of the universe. It will not simply strive to come up with the best possible philosophical ideas on individual subjects.
The system to be presented here will strive for a synoptic vision (a term used by Plato for the wide picture philosophy should present) but will not be intended as speculative. It will undertake a comprehensive survey of information that has been put to a vigorous test for veracity and try to assess its impact on human life. It is sincerely hoped that it will meet the criterion of Rudolf Carnap quoted in the preceding chapter for an acceptable metaphysical system. If it fails to meet the criterion, hopefully Carnap and other tough-minded analytic philosophers would not find it too objectionable.
You will notice some writing idiosyncrasies. At times, i will use the pronoun "i" whenever it seems more straightforward to do so. You will notice that i do not use the customary capitalization of the pronoun "i"; it seems too egotistical. At times, the pronouns "we" and "you" may be used whenever appropriate and in order to let you feel more involved. I will use "metaphysicist" for the traditional "metaphysician" and "ideaism" for "idealism." Metaphysicist is preferable to be consistent with the use of physicist for someone who studies physics. Ideaism should be preferred to idealism because the latter also means the holding of high ideals. Ideaists have probably enjoyed the two meanings being run together throughout all these years, but it is not fair. Ideaism should be clearly set apart from any hint that it holds any moral superiority over rival metaphysical systems. Furthermore, ideaism is also closer to the claim that ideas in human minds are paramount in reality.
Looking Ahead in This Book
The objective of this first book, The Predominance of the Physical World, is to establish that there is a physical universe existing in space and that correspondingly our world is a physical one that supports everything on it. The evidence will cast doubt on claims that there is a spiritual or mental substance apart from physical substance. It will address the claims of nonmaterialists and extreme ideaists who believe that all that exists is spirit and that there is nothing material. To them, any physical objects are an illusion. In philosophical terms, this book will try to show that the philosophical doctrine of physicalism is the correct one, as opposed to ideaism and dualism.
The first two chapters will set out the most basic observations a person can make about nearby objects and their own existence and then examine the composition of objects. Several chapters that follow will provide a brief look at different scientific areas to see what light they cast on the substance of the world. They will show that there are extensive physical explanations of how the world works. Important issues in the philosophy of mind will then be treated including the mind-body problem. I will discuss my possible solution. A final look at the concept of spirit will be taken, along with the question of whether God could be material. An attempt will be made to come up with an acceptable definition of matter, along with an examination of the nature of space, time, and mathematics.
The Next Two Books
Book 2, Knowledge and Free Choice, will approach some traditional philosophical problems that need close attention. It will first delve into epistemology, the study of knowledge. Certain issues need to be considered, including some that bear relation to the special knowledge claimed by religious people. Hopefully Book 2 will clarify questions about knowledge that may have come up in this book.
It is common for people in everyday life to assume that others are in full control of their actions and that they should be held responsible whenever they cause harm to others. This is clearly the assumption under which the criminal justice system works since the accused are meted punishment under the assumption that they were able to control their wrongful actions. The same goes for the religious context since most religions hold that the gods punish humans for their sins. With these considerations in mind, an attempt will be made to gain an understanding of free will, the ability to control decisions. The doctrine of determinism holds that actions cannot be controlled. Some conclusions will be attempted in deciding to what extent humans can be held responsible for their actions in light of human nature and the nature of the world.
Hopefully the findings about the world and human nature will help in Book 3, which will be an exploration of the mystery of God. The book will begin with some traditional topics in the philosophy of religion, such as evaluation of the proofs of the existence of God. It will assess what kind of world God wanted to create. Divine punishment will be considered in connection with free will. A basic ethical rule that applies widely will be proposed. The book will finally attempt to come up with the most accurate picture of God based on the evidence available and to assess how humans can be expected to respond to such a picture.
Some minor topics in philosophy will not be discussed, thus it can be said that these books will not present a complete metaphysical picture. The subjects presented in this trilogy should suffice for giving a very wide sense of what the universe is about. Other topics like aesthetics and language are interesting but not crucial to the understanding of the universe and the place of humans in it.
In attempting to reach fundamental ontological truths, I will make simple, initial observations of what i find in my immediate surroundings and then use those observations as a basis for deciding what phenomena are truly found in the universe. The test that i will use to determine whether something that i observe actually exists rather than being a mere illusion will be that the observation be "clear and distinct," the exact phrase repeatedly used by Descartes as the standard for gathering indubitable truths. It is not possible to elaborate very much on those words beyond their common and accepted meaning. It is true that much criticism has historically been leveled at the phrase for being too vague, but i will forge ahead and use it because it is hard to see that any other phrase would do any better. The criterion for deciding whether something exists definitely has to be a solidly reliable one. Conjecture will not suffice nor will bias nor wishfulness that an alleged thing actually exists.
Sense Experience
I will proceed in a philosophically naive manner without stopping to decide whether sense experience constitutes knowledge or not. I will not try to decide whether Wilfrid Sellars was right in alleging that there was a "myth of the given."(See Empiricism and the Philosophy of Mind, Robert Brandom, ed. (Cambridge, MA: Harvard University Press, 1997).) In pointing out there was a myth of the given, Sellars was disputing the claim by empiricists that sense experiences furnish knowledge. A well-known proponent of the idea of the given was C.I. Lewis.(See Mind and the World Order (New York: Dover, 1956; originally published by Scribner's, New York, 1929). I will assume that there is at least some information in sense experience. After all, even Sellars admitted there has to be some kind of noninferential knowledge based on sensory experience, and F.H. Bradley, an ideaist who attacked the empiricist position, saw the given "as a coexisting mass."(F.H. Bradley, Appearance and Reality (Oxford: Clarendon Press, 1969) 198.)
To accommodate the questions about the given, I will assume that the act of perceiving a stimulus does not necessarily give complete knowledge but is only the gathering of information by the brain, like a computer or video recorder gathering data only. A specific example would be a digital sphygmomanometer (blood pressure meter) that displays a person's blood pressure readings on its screen. It does not seem that the instrument is engaging in the act of thought or of acquiring knowledge by simply measuring, recording, and displaying numbers.
The human act of perceiving is immediately followed by the brain's assessing and judging the details of the stimulus or sense datum. (I will even dare to use that old term.) In the case of the perception of a red apple, for instance, the brain makes the assessment that the red image in front of it is indeed a red apple because it is round and yet not perfectly spherical but instead has characteristic features. Touching, smelling, and tasting it confirms other relevant features. The perceiver was taught from childhood that all these observations indicated the object was a red apple. On the basis of the assessments, the final judgment is made that it is a red apple. The process of assessing and judging the sense data involves the gathering of knowledge, but the actual initial taking in of the sense data may not count as knowledge.
I am taking a leap in proceeding to employ my sensory experience in trying to gain knowledge before dealing with related epistemological issues brought up by some philosophers who came after Descartes. I will take this avenue partly because Descartes started his analysis about what he could establish as fact without delving into epistemological concerns. It also seems as if it is the most natural way that people would start taking inventory of what they know.
It would seem that the proposition that we know physical objects through perception by our senses is obvious and noncontroversial, but such is not the case. Under philosophical scrutiny, the proposition has been very hard to justify with complete certainty. How certain can we be that all the objects that we observe all the time really exist? The problem falls under the heading of "knowledge of the external world."
The Road to Modern Skepticism
It was John Locke that stirred the pot unintentionally in his Essay Concerning Human Understanding.(John Locke, An Essay Concerning Human Understanding, Peter H. Nidditch, ed (Oxford: Oxford University Press, 1975).) The skeptics of the first century B.C.E. had claimed that one only knows sensations and nothing about the objects that might represent them.(D. W. Hamlyn, "Epistemology, History of," The Encyclopedia of Philosophy, Paul Edwards, ed. In chief (New York: Macmillan & The Free Press, 1967).) Like Descartes whom he admired, Locke wanted to set down what humans could count as certain knowledge. He specifically wanted to ascertain what it was that humans know about objects, or bodies as he called them. He pointed out that the mind does not immediately come in contact with an object with which it is confronted but instead perceives an idea produced by the object. More specifically, the object possesses qualities that give it the power to produce an idea in the mind.
These qualities he divided into primary qualities and secondary qualities. Locke considered that the primary qualities were inherent in the object and could not be separated from it. The primary qualities included solidity, extension, shape, motion, and number. Locke took the primary qualities to show that objects exist because the primary qualities resemble them. The secondary qualities did not reside in the objects themselves but were considered by Locke to merely be powers in the objects to produce certain effects like color, sound, and taste. Secondary qualities did not play a part in establishing that the object existed. Another way of looking at it was simply to say that physical objects standing apart from our minds had to cause the ideas that we had of them.
George Berkeley pointed out in 1710 that the primary qualities were not as steadfast as Locke assumed. For instance, the size or the shape of an object could vary depending on the distance or angle of observation. Primary qualities were just sensations, just as in the case of the secondary ones. They could not be used as proof that there were any physical objects causing them. All that could be said when we observed objects was that we experienced sensations. For all we knew, there were no objects. It was all in our mind. Berkeley took on the skeptical problem related to objects in an external world because he was concerned that the skeptical doubts that had been unleashed by Locke could cause religious doubts in people. Berkeley was an Anglican bishop. In spite of his best efforts, Berkeley only introduced more skepticism into the discussion. Hume pointed this out and introduced additional skeptical observations.
Immanuel Kant later lamented that by his time no solution had been found to the problem. He offered clarification that was widely accepted by philosophers that followed him. There were groups called the Kantians and later the NeoKantians. Today, few think Kant came up with any satisfactory answer to the problem. Kant did come up with a new name for putative objects in the external world, ding-an-sich (things-in-themselves), but admitted they could not be known by the human mind.
Philosophers have been struggling mightily with the question to this day but have still not come up with a solution. Hume said the problem did not bother him in his everyday life. He simply went about his social interactions as if there were no problem at all. It was only in his philosophical ruminations that he paid attention to the matter. Most people who have studied the problem no doubt feel the same way. For this reason, i will proceed under the assumption that our senses are reliable enough to inform us that when we observe an object, it is in fact present in some form and not merely a perception in our mind. There is something outside of our bodies that causes our sensations of seeing, hearing, etc. There is an important point that is subsumed under the idea of lack of knowledge of an external world. It is that skepticism about physical objects has to include doubt about the existence of living objects (beings) other than you, the observer.
If you decide to believe that humans are actually out there, then there is still the problem of the existence of other minds. After all, beings that appear to have a mind could simply be robots without inner consciousness or any awareness that they exist. This is the problem of other minds that has been studied in philosophy for a long time now. All of this can ultimately lead to solipsism, the position that the only thing that can be known with certainty is the mind of the perceiver. Book 2 will tackle the problem of solipsism.
Here i will try to assume as little as possible before making these fundamental observations but will need to refer to some extent to past acquaintance with the parts of the universe that i have easily observed in the past. I will assume facts known to most people in order to round out some of the observations. I am confident that these assumptions will not be controversial. I will, for instance, use concepts like shape and color. If i were only becoming conscious of my surroundings for the first time, i would surely be noticing different shapes and colors without even having names for them. I will have to use the names in order to communicate with you the reader. I will begin my observations outside in the daytime. It will be in a desert area near a neighborhood of residential homes.
The Observations
I look down and see different images near my feet and around me. Some are brighter than others and also differ in shape and color. They are all on top of an extended image. I raise my gaze gradually and continue to see the image until my eyes meet with another extensive image immediately above the first one. It is present all around and above me. If i turn around a full 360 degrees, it is always present. It appears to be located a long distance away. In it there is a round image along with a few other images of different shapes and sizes. I cannot look at the round image because it hurts my eyes.
The first extended image continues into the distance and in some places rises into different formations of varying shapes. Some formations are further away than others. So far i have only seen images and have no evidence that they are anything apart from my imagination. So i reach down to pick up one of the images near my feet lying on top of the extended image below me and observe how it feels in my hands. I turn it around in different directions and observe that it has an uneven surface. It does not extend flatly like the other images I see but instead has another quality. That quality i will consider as depth. It is hard.
For this reason, i will call it an object rather than an image. It is a beige color. I release the object and it goes straight down. I pick up another object near my feet, only this one is smaller. It also has depth and, when i let it go, drops straight down like first one. I pick up several other objects of different shapes and sizes to see if they will all fall and find they also fall straight down in the same amount of time. Touching the objects clearly furnishes additional information to simply perceiving them with my eyes. They make a sound when they hit below but are silent otherwise. I smell them and and lick a couple of them and do not find much taste. There are other objects lying around that are green and yellow. None of the objects mentioned so far show any movement of their own, but i am able to move them readily.
Now i see a small black object that is moving in front of me. I walk toward it, and it accelerates its movement and turns to the right. It moves using four protrusions under it. I crouch down to get a closer look, and it stops suddenly and does not move at all. After i stand up and take a few steps back, it starts to move hurriedly away from me. It is dome-shaped on top.
Let us review. I talked about images in the beginning to show that one is only truly aware of two dimensions of vision unless one explores further by walking around objects or by handling them. I referred in general to colors and varying degrees of light in connection with the rocks lying on the first extended image, the ground. The ground met the sky that extended all around me and well above the ground. The sun and some clouds were in the sky. I could have described the sky as blue, the sun as yellow, and the clouds as white, and that would not have been in doubt.
I then noted that the ground at some places rose to higher levels and formed mounds, hills, and mountains. I picked up a rock and noted it was round and hard. It was three-dimensional. I dropped it and some other rocks, and they all consistently took the same amount of time to fall to the ground. I tested all my five senses on the rocks. Even if one or more of my senses had fooled me, it would not have meant that they did not provide me with accurate information. It would not have meant that i could not be confident that they existed.
Descartes doubted his senses in his Meditations on First Philosophy.(Reprinted in The Rationalists (New York: Dolphin Books, 1960) 99.) The Meditations was a fuller exposition of the method Descartes first announced in the "Discourse on Method." Both found that the senses are not reliable. I found the opposite. My senses seemed very reliable. I saw some areas with yellow grass and some green plants. They were stationary, and i could easily touch them. Finally, i saw a black beetle scurrying across my path that reacted to my movement. It was clearly conscious of me when it froze in its tracks to avoid being detected. Unlike the ground, rocks, and plants, it was capable of self-motion (locomotion).
From here on, i will make greater use of common names in order to make the narration easier and clearer. I wanted to start by using few common names in order to engage in the most basic observations in the most stark manner possible to ensure that the observations were clear and distinct and, if not exactly indubitable, then difficult to doubt.
I will now walk further. I am now approaching houses and my house is not far away. I see a tree with its leaves moving. The leaves move irregularly. I stand there for a while to see what makes the leaves move. After some time, I notice that something in space seems to push on me. The force is not visible. I then observe that the tree leaves move at the same moments that I feel the force. I later also realize that the leaves are pushed in the same direction toward which the force seems to push me. I continue feeling this force as I walk. This force is the wind. I conclude that objects are always stationary until i move them, while others seem free to completely move on their own like the black beetle.
The sun is in a different position than it was this morning so i must infer that it has moved. I stop for several minutes to see if i detect any movement of the sun but do not observe any. I see two small objects move quickly above me. They are birds. I see a man walking two blocks ahead of me. I see a small object similar to the beetle i saw before. It is standing as if contemplating something. I am at a safe enough distance away that it doesn't run away as i pass by. It is facing in the same direction i am going. It is moving its antennae busily. It is a cockroach.
I see another large moving object. It is composed of two arms, two legs, a head with two eyes, two ears, a nose, and a mouth. There is hair on its head, and none on the face. I observe myself. I see that i have two hands each attached to an arm that is each in turn attached to my torso. I have two feet with their corresponding legs with which i am able to walk. I can see and feel the rest of my body. If i look down, i can see my nose but not the rest of my head or my neck or my back. I can, however, feel these with my hand including the hair on my head, my two ears, and my two eyes. When i pass my hand over each eye, the respective eye feels the touch of the hand and sees the hand just before it touches the eye. I appear to be very similar to the object i saw.
Confirmation
I reach my house, go in, and walk to the bedroom to stand in front of the closet doors that are completely covered with reflective mirror glass. I now have a complete look at myself. I turn and look at my sides and parts of my back. I then use a hand mirror to get a look at any part of my body that i want to see. I walk forward, then backward, to my left, to my right, and jump up and come down. This confirms that there are three dimensions.
I remember walking in the desert earlier and making the observations that i did. I remember seeing the man at a later moment. This confirms that there is such a thing called time by which we keep track of motions of objects. I now want to confirm a few facts and so go into the room where my wife is reading.
I ask her, "Is that a different book you're reading?" I assume so because i haven't seen her with it before, and it is open to the beginning pages.
"Yes, i started it this morning."
I stand in front of her, hold up my left arm and ask, "What am i doing?"
"Holding up your arm."
I hold up my right arm, "What am i doing now?"
"Holding up your other arm." She looks puzzled.
"I am conducting a test," i inform her.
"O.K., whatever," she comments and goes back to reading.
It is clear that i was visible to her and that we were in coordination on what we were observing. There was intersubjectivity. We could each confirm what the other was seeing. I could have gone on to ask many more questions, but i don't think it was necessary. I am confident of the answers i would have gotten and that they would have shown coordination in our observations. I am also confident that there would have been consistent intersubjective confirmation with any number of other persons that i could have asked to confirm my observations. So far i can confidently say that many images appear to be beyond me and not simply a product of my imagination.
After nightfall, i eat dinner, which consists of broccoli, fresh carrots, oatmeal with white beans, bread, and an apple. I now get the chance to feel objects in a different way. I bite into them, chew them, roll them around in my mouth. When I swallow them, i feel a solid lump going down. They are definitely solid. The food came out of the ground or grew on plants that came out of the ground. The material for manufacturing the pots, plates, and utensils used to prepare and serve the food also came out of the ground.
Later, i listen to the news about the day on the radio and read some news items on my cellphone. I go to the window and find that visibility is greatly diminished from what it was during the day. The sun is nowhere to be seen, and there is no longer a blue color above. Instead, it is all black. Upon a close look, i see points of light in the darkness above. They are all small.
In reviewing the observations catalogued today--and there were very few in comparison with the total number of perceptions that i normally make on any given day--i know that i had a clear and unobstructed view of the things i saw. I am confident that my knowing was beyond much doubt. Now i am not claiming that no one could reasonably dispute that i was correct in claiming certain details. I could have been wrong in identifying the beetle and the cockroach as such. They could have been another kind of insect. What is important in what i claim is the broader picture: a thing called the ground, stones on it of different sizes and colors as well as different plants, a bright sun in the sky, and so on. The objects i pointed out were in the sky or were standing on the ground or came from the ground. The important point is that there are some very familiar objects that are the subject of very commonplace, basic observations. Only an unreasonable person would dispute these observations, or perhaps a philosopher under the spell of an unrelenting skeptic who always insists on absolute certainty.
Clear and Distinct Objects
I can confidently say that not only i, but also virtually all humans--to say nothing of all the other animals--have a clear and distinct idea of all the objects found in everyday experience. I not only had a clear and distinct idea of each of the objects i observed, i was amply familiar with the type of objects they were. That is, in my many years on this earth, i had many times seen beetles, cockroaches, and other crawling insects as well as trees with fluttering leaves caused by something called the wind, which is completely invisible. In that time, i became well-acquainted with stepping on the ground, seeing it extend indefinitely in all directions with different shapes of rocks, plants, and trees on it, and a sun, sky and sometimes clouds above. I became so well acquainted with those and other common phenomena that i eventually took them for granted and never doubted that they were present.
I suppose i may have previously doubted the existence of these familiar objects at some point, perhaps in the first two years of my life. It may have happened, as it may happen to all other children under the age of two, that i had doubts about objects around me and explored them carefully. That certainly seems to be what many children are doing when they peer at and carefully handle objects over and over again as if making sure that they are truly real. They may also be trying to find out their composition. I don't have any recall of doing that, much less what i was thinking as i did it. I have never talked to any one who had memories along these lines.
All my life i have had continuing contact with humans as well as other animals starting with my first acquaintance with my mother, father, doctor, and nurses who were at the hospital where i was born. I have seen thousands of humans in person in my lifetime, both individually and en masse, as in auditoriums and in stadiums. I have also seen many of them in photographs and films. I have observed that humans have the same general physical characteristics, such as eyes, nose, mouth, arms, stomach, etc. I have had occasion to touch many humans. I have also observed many cats, dogs, domestic birds, and other animals and insects.
My senses have always been in good working order, as far as i can remember. I have not been fooled. Based on touch, i can say without a doubt that these creatures are all physical objects existing in three-dimensional space. The existence of these creatures is supported by references in books and other media. I have examined books on biology, human anatomy and physiology, and medicine containing extensive studies with drawings and photographs of creatures, which shows that many other people are aware of the existence of these objects as well as their parts.
There are a number of natural objects and phenomena that i did not mention such as water, rain, fire, lightning, etc. that exist without a doubt. Then there are multitudes of artifacts that have been constructed by humans throughout the many years of their existence. While these artifacts are not found in nature, they are all physical objects that were fabricated from material that came from the earth. Many pots, pans, spoons, knives, and other kitchen items are made from iron, copper, aluminum, and other metals. Gardening tools are made from wood and pure or amalgamated metals. These kinds of items have been fabricated for millennia and have been commonplace in homes.
Houses and other buildings are constructed from items derived from dirt, sand, wood, and rubber that come from trees, iron, copper, and other natural materials. The furniture inside the house comes from wood, pure and amalgamated metals, cotton, and other natural and synthetic fabric. Similarly, clothing is derived from cotton and other natural and synthetic fabric. Numerous items today contain different types of plastic, which is derived from oil found under the earth's surface.
Many types of items found in the world today would not have been recognized by people living before 1900. The Industrial Age produced a multitude of tools, instruments, and gadgets and continues to do so at a brisk pace. Numerous physical and chemical materials have been formulated by humans and have enabled the manufacture of machines, weapons, instruments, drugs, and many other objects since 1900.
In spite of all this novelty, there is still not a single item, not even the most advanced cellular phones or computers, that does not count as a physical object and that is not ultimately manufactured from physical objects that are extracted from the earth, which itself could be counted as one immense physical object.
If people living in the year 1600 were to witness the countless technological innovations that have been invented since their time, they would probably believe there were supernatural forces behind many of the inventions. This is especially understandable in relation to some inventions like the camera, the radio, and television. It is said that some native Americans in the late 1900's did not want to be photographed because they thought a person's soul was captured in a photograph.
There is not a single invention ever made that is explained by supernatural forces. All the machines, toys, and gadgets found on the earth today are composed of parts that are physical objects. They have all been designed, created, and manufactured by human beings following scientific and technological knowledge related to the earth and its nearby surroundings. No human-designed item has been found that operates by other than known physical or chemical principles or is composed of other than material from the earth. At least, there has been no credible report of any of this.
It is hard to ask someone else to confirm the existence of specific physical objects; they find it hard to see the point and get impatient. Probably less than .1% of the population would express any doubt about the existence of the types of specific objects i discussed above or of physical objects in general, from the big to the small. Only someone suffering from a severe defect in their sight or touch or someone having extreme schizophrenia would have doubts and then probably only about some of the objects. It is clear and distinct that physical objects exist.
Universal Agreement on Objects
If questioned on the basics of the world, virtually everyone would declare the existence without question of all the items mentioned above and many more. They would vouch that numerous objects exist that move in predictable patterns.
They would also express great confidence in a number of other facts about the world that they might not understand very well but with which they are very familiar. Examples of such natural phenomena are the wind, microbes, fire, food that imparts energy and nutrition to living things, gasoline that enables motor vehicles to move, and a type of electromagnetic radiation that makes it possible for millions of people thousands of miles apart to listen to the same words simultaneously on their phones, televisions, and radios. Those who have studied these phenomena can explain all of them to the public.
I have tested the idea of the existence of physical objects in three ways. First, i carefully and methodically observed various objects and decided i had a clear and distinct perception of the existence of all of them. Second, i consulted my lifelong memories and found that i had a clear and distinct idea of the same objects (rocks, the sun, the moon, etc.) from the past. I also remembered an additional multitude of physical objects that i had experienced in the past. I also found that the images from the past were consistent with my present perceptions of same or similar objects. Third, i imagined in my mind what answers i would receive from people if i asked them if common objects really existed. I know they would have confirmed the existence of the same objects based on their present perception as well as their past memories.
The fourth and final test i would like to run is one of negation. I will simply deny that physical objects exist. I am looking at a chair, a small television, a bureau of drawers, a stereo speaker, my bed, and a painting on a wall. I am writing on a notebook that is supported on a thin board and am holding the pen i am using. I am looking at several walls inside my house. My lovebird Lulu is in her cage that is hanging from the ceiling. I will deny the existence of all these, as well as many other things that i see in my house. I will also deny the existence of my house along with all the objects outside like the ground, the trees, and the sun. For good measure i will also deny that i have ever in my life seen an object.
I close my eyes to give a chance for all these items to disappear by the time i open my eyes again. I open my eyes and find all the items still there. I close my eyes again and keep them closed for a longer time, about ten minutes this time to make sure enough time goes by. I open my eyes again and see everything there again, exactly as before. I am still on my bed with the same pen in my hand. All the other items are the same; they haven't even moved (except for Lulu) or changed appearance. I get up to touch the television and the chair, and they feel exactly the same as they did before. That night before i go to bed, everything is the same. I sleep for seven hours, get up, and everything is still the same. It seems that denying the existence of objects has no effect on them. They are still there just the same as before.
The Existence of Objects
It has now come time to conclude that objects exist. They cannot be denied, are ubiquitous, and are readily confirmed by others. The evidence for objects is overwhelming. I conclude that there are always objects all around. There are more under the ground and inside the oceans. Objects are capable of motion in three perpendicular directions, known as three-dimensional space. Objects move predictably according to rules such as the law of gravity. Some motions take place before others. With the help of certain objects, such as the sun, sundials, or clocks, one can keep track of time.
Objects are most commonly perceived by vision. Touch and sound also come into play in the experience of objects with smell and taste being less common. There are a countless number of objects in the world, to say nothing of the rest of the universe. Any one person gets to experience only a very small portion of the material world. Hardly anyone gets to see the oil deposits and water tables under the ground surface. Few people get to see the glaciers in Antarctica or plants at the bottom of the ocean or Mt. Everest or the city of Tikrit, Iraq.
Nevertheless, people have little trouble believing in the existence of numerous objects because of the nature of those things and of the evidence. It is not hard to believe that there are places where oil or water is pumped out of the ground. One can arrange to go see them first hand at the site of oil or water wells. It is not difficult to believe that there are plants and mountains and cities full of people on other parts of the earth. Hearing eyewitness accounts or reading books or viewing photographs and videotapes about distant places is reliable evidence. If there are doubts, they are usually about details, like where a particular species of bird is found in northwestern India.
Furthermore, there is great consistency in what appears on different parts of the earth. The familiar things i observed before are seen universally around the globe. The main differences are in the appearance of the terrain--desert, mountain, forest, seaside. Things like dirt, water, stars, and tomatoes look the same around the world. All of this contributes to the unquestioned confidence people have in the existence of things found in the world.
I Am an Object, Therefore I Am
People, even the most punctilious of philosophers, have clear and distinct ideas of objects that are capable of motion in space. Why was the same not obvious to Descartes upon beginning his skeptical investigations? The simple reason was that Descartes had an agenda that required the mind to come out well ahead of the body. More on that at the end of the chapter. He did eventually establish the existence of objects in a roundabout way. If Descartes had honestly examined the reasons for accepting objects at the outset, he would have found sound reason for believing in their existence before having to discover his thinking mind.
For the sake of comparison with Descartes' way of proving his own existence, i would now like to find the simplest way to show my own existence. In examining objects that were around earlier, it did not take long before i realized that at least parts of me, like my hands and feet, were present. Upon closer examination, i could see that they appeared to be objects that were part of a larger object that was my body. I went into the bedroom and stood in front of the closet doors with mirrors and saw my complete body. I could further see that i looked very similar to other objects called humans and could understand that i was a member of that group. I now look at my body again and see that it still appears as it has for many years. I look down and see my chest on top of my stomach on top of my legs on top of my feet. The same goes for my arms and hands. I am sure that if i returned to the mirror doors, i would be able to see my back. Everything is there as before.
I could choose to go to a different room in the house and my body would come along wherever i might decide to go. I could even go for a walk outside and my body would inevitably go. It is inconceivable that it wouldn't go. I would need it to get around. It has never happened otherwise. There is no escaping it. I can imagine my head moving in the air down the street while leaving the rest of my body behind, but nothing remotely like that has ever happened. I have never heard that it ever happened to anyone else. How would my head be able to move independently without falling to the ground?
As i did before in testing the existence of other objects, i can use my other senses besides sight to confirm my existence. I touch my forearm and feel that, while the muscles and skin are pliable, it is nevertheless a solid object. It exists in three dimensions. I talk and clap my hands and thus hear sounds made by my body. I lick my right forearm and find no taste. I try to smell myself and happily detect nothing, but then i know my olfactory sense is not very sharp.
I can remember seeing my body or parts of it many times before in my lifetime. It has always been essentially the same face going back to childhood, although now sadly with added wrinkles. I have photographs of myself as a young boy that have a similarity to me today. I can confirm the photographs because i remember where they were taken and remember going to have them taken. I still have faint scars from cuts i remember getting as a kid. I can still walk and move my body freely but not as quickly as in the past. My mind is also slower. (If i live to 100, my mind will deteriorate much more. Could that mean that my immortal soul (mind) will be forced to operate at that level for eternity?) My body has had a relatively fixed and constant identity. It has followed a determinate timeline since birth. I have never switched bodies, and even if i had been able to, i would still be object-based. I would still be an object at all times, even if not always the same one.
Descartes went for pages of the Meditations asking himself what he was. I do not have to do that to find out if i exist. It is clear that i am an object, more often referred to as a body. I can declare: I am an object, therefore i am.
The objection can be made to considering myself to be an object is that my hands, feet, and other parts of my body may not exist in space but only be figments of my imagination. If that is true, i am still something. My hands, feet, and the other parts of my body may just be puffs of imagination rather than spatial objects, but they are still something. Furthermore, they perform acts and functions that are helpful to others and me. They don't need to exist in space in order to do that. In virtue of those capacities, they have existed for a long time and continue to exist. If I am imaginary, it also has to be that all other objects are imaginary. This seems a very outre notion, but even if this were the case, i could still say that i knew that i existed, even if it was only as an image.
I Perceive, Therefore I Am
It is possible to further confirm my existence by a method closer to, but more simple than the one used by Descartes. It appears he envisioned thinking as the use of various human mental faculties. It was not necessary, however, to enlist many faculties of the human mind to make the point that he existed.
It is clear that i am perceiving various things--objects or even just images. I don't even have to commit to seeing clearly or to perceiving three-dimensional objects. As long as i engage in perceiving something, i can know that i am a perceiving subject or instrument of some kind. I don't even have to know what i am looking at, only that i am something that is perceiving stimuli. I can even have a limited, subhuman mind. I have to be is a perceiving instrument, even something similar to a "seeing eye."
Alternatively, the perception would not have to involve sight. It could be any one of the other senses, like hearing sound or tasting food or feeling pain. If i hear music, i know i must be something--a sound amplifier or a home theater system or the conductor of the New York Philharmonic. I do not have to go so far as claiming that i can only discover my existence through thinking. The sufficient phrase in this connection is i perceive, therefore i am.
An indispensable factor involved, and which Descartes failed to specifically mention, is that i must perceive that i am perceiving. In order to become aware of my existence, i must not only engage in perceiving, i need to also be aware that i am perceiving. In other words, i need to have at least a minimal amount of self-consciousness. I must be able to realize (1) that it is an individual object or entity that is doing the looking or tasting and (2) that the object is "i." The more accurate formulation for knowing that i exist: i am aware that i perceive, therefore i am.
Most humans, and perhaps some primates to a limited extent, have the capacity for self-consciousness. It is doubtful that a fly has the ability. It no doubt is aware of objects around it, but whether it is aware of itself is another story. However, i wouldn't have to have the level of self-consciousness found in humans to perceive that i exist. Humans can after all be very articulate in describing their inner states. I would only need a weak self-awareness. This reveals still another formulation for knowing that i exist: I am self-conscious, therefore I am. It would not involve thinking beyond that level of minimal self-consciousness, if that can be called thinking at all.
Descartes' Agenda
Descartes did not need to go so far as to establish that he was a fully thinking being in order to be convinced of his existence. All that was necessary was to establish the simple requirements of being an object, even an imagined one, and of having a minimal awareness of that. Instead, Descartes went through the much more elaborate approach of showing he was a thinking human. This was important to him because he was ultimately trying to establish more than a basic awareness. Why was it that he could not be sure of anything until he found what was later called the cogito argument--cogito, ergo sum(i think, therefore i am)?(Meditations 119)
First, Descartes had a premeditated agenda that was made obvious by the letter he printed at the beginning of the Meditations. It was addressed, "To the very sage and illustrious, the dean and doctors of the sacred faculty of theology of Paris," which was at the Sorbonne. Descartes clearly announced his motive: to use philosophical arguments rather than theology to establish "that the human soul does not perish with the body and that God exists."(Id. 99) Although he pointed out at the outset that the senses were reliable,(Id. 113) it was still possible to doubt them and the existence of objects, including the body.
So it was not surprising that the body and other physical objects got short changed under Descartes' scheme. After some rumination on how he could be deceived, the mind or soul (Descartes seemed to make no distinction), came shining through. Not only did it indubitably exist, the mind--rather than the sense of sight--was actually accomplishing the perception of a piece of wax. ("I know the nature of this piece of wax not by imagination, but by purely mental perception" and "[T]he objects that I thought i saw with my eyes, I really comprehended only by mental power of judgment."(From Meditation II in Descartes' Philosophical Writings E. Anscombe and P. Geach, trans. Bobbs-Merrill, 1971.) Since Descartes was trying to prove that the human soul was immortal while the body was perishable, it was convenient to postulate that (1) its existence was much less immune to doubt and that (2) it was superior to the bodily senses even in the act of perception.
Second and related to assuming the soul to be nonmaterial, Descartes followed an old philosophical tradition going back to the time of Plato that the perishable body is to be considered inferior to the soul. With all these prejudices being so obvious, it would seem that the later followers of Descartes on matters of the soul and metaphysics would have been more skeptical of what he had to say.
From a metaphysical (and practical) standpoint, there are strong reasons for assuming that objects really exist apart from the observer, that there is space containing countless objects, and that the observer is one of those objects. Up to this point, the existence of physical objects has been determined by the way they look and feel. One of the first things i did in my physical investigation was to pick up a stone and notice that i could feel that it not only had length and width; it had depth. I later saw that i could move in six different directions--left, right, forward, backward, up, and down. The stone and i were thus three-dimensional objects in three-dimensional space. It felt hard and solid, and when i knocked on it, there was a hard sound. John Locke thought that a feeling of solidity showed that an object was three-dimensional.(Locke 122-127)
In spite of these well-known observations, the investigation will be continued into whether physical objects exist. We could be deceived into thinking there are three dimensions. After all, good painters have for centuries been able to make their paintings look three-dimensional while yet existing on what can be considered a two-dimensional surface. Computer artists are always continuing to improve their computer images to look as solid and life-like as possible.
From here forward, whenever an object is said to exist in space, it is to be a physical or a material object with "physical" and "material" understood as synonymous. Physical is taken to have body, be measurable, be made of matter, and exist in space. I will later use the word "material" closer to the sense in which it means the elements or parts or constituents out of which things are made.
Object Deniers
There is hardly anyone to be found who seriously believes that there are no physical objects so the following discussion will probably seem unnecessary and tedious in view of its parsing of various unlikely possibilities, but it will be undertaken in the interest of thorough philosophical analysis. There have been those who have claimed that the physical world does not exist including early metaphysicists in India. The Ideaists (customarily known as Idealists) of the 1800's seemed to at least come close to expressing that.
Followers of the more recent religion of Christian Science also deny the existence of a physical world, but as with other nonphysicalists, it is not clear how they support their ideas on physicality apart from claiming insight into the divine mind that informs them on all the details of the universe. Mary Baker Eddy was the founder of the religion in the 1870's and made various disparaging remarks about the physical world. Here is a passage from her main book of guidance, "There is no life, truth, intelligence nor substance in matter. All is infinite Mind and its infinite manifestation, for God is All-in-all . . . . . Spirit is the real and eternal; matter is the unreal and temporal."(Mary Baker Eddy, Science and Health with Key to the Scriptures (Boston: Christian Science Publishing Society, 1875) 468.)
The attitude that matter is not real continues among Christian Scientists to this day. In 2005 the Christian Science Journal, a monthly magazine of the Church's publisher, printed an article commemorating Albert Einstein's discoveries in the year 1905. The author talked about how Einstein's findings on relativity made unclear the nature of time and space. Many New Age authors have also liked to use Einstein's theories of relativity to point out strange inferences about time and space and even that they don't exist. The article contained three interviews: one with physicist Brian Greene who had written a book on string theory and two with Christian Scientists. Greene made it clear that he believed in physical things. Neither of the other two challenged Greene on physical grounds. One of the other interviewees made the assertion that matter does not exist but based this wholly on religious grounds. Here is a statement of the author of the article from his introduction, "Hence, the stunning significance of Mary Baker Eddy's challenge to the uber-assumption that matter exists and her conclusion that instead reality is entirely spiritual. That you and I are immortal ideas--unique thought-forms created and maintained by the one infinite Mind, or God . . . . . That matter is not real--Spirit is real."(Jeffrey Hildner, "Time Space Matter: Seeing Through the Grand Illusion," Christian Science Journal, July, 2005, 44 at 46.(Vol 123, No. 7).)
While it is not clear what the opponents of the existence of physical objects believe does exist, they have in common the desire to deny or diminish the physical world. One claim is that the only thing that exists is a single spirit or mind. The question then arises: is this spirit itself a physical object--the only one in existence--or is it something else? Usually these solitary-mind proponents get away with simply answering that the mind is nonphysical and are not pressed any further on it. Given these and other questions, it is important to delve into the question further.
Nonphysical Objects and Ghosts
Spirit, mind, and soul are often considered to be synonymous. Mind can be thought a little differently but the similarity is there. Philosophers can mean something apart from spirit. Dualists are more likely to use the terms synonymously. Dualism is the doctrine that body and mind are made of two very different substances usually called material substance and spiritual or mental substance. Spiritualism or ideaism is monistic in holding that there is only one substance in the universe and it is spirit or mind. Physicalism or materialism is also monistic in holding that there is only one substance and it is matter.
The first possibility for the composition of spirit--which is clearly claimed to be different from that of physical objects--is that it is made of some special material, mental substance as Descartes labeled it. Nonmaterialists do not give details on the constitution of this special substance or how it works. A nonmaterialist or spiritualist is someone who does not believe physical objects exist at all. Some may concede that physical things exist in some form but all disparage their significance. None accept the view of matter commonly found in the science of physics.
The special substance of spirit or mind is considered nonphysical in that it is not supposed to have anything like the composition of ordinary physical objects. Often it seems to be considered as something fine and airy that is not knowable by humans. A ghost would be a good example of something made from it. Ghosts or spirits would be individual instances of this special substance.
Another possibility for spirit or mind is that it is not made of anything. It is so special that it can be made of nothing. A third possibility that is rarely considered is that spiritual substance could be made from the same material that makes up ordinary matter. It could be made from the very same physical elements that have been catalogued by scientists but arranged in such a way to make it very different. It could still interact with ordinary matter.
Exploration of the possibilities has to be based on common human experience of how things have worked in the past. One would expect a description or explanation based on past experience of how spirits are made, and if not, at least some justification for accepting that they are different from ordinary objects.
What then are those ubiquitous images? The nonmaterialist could claim that they have a makeup similar to ghosts, which have been understood to be nonphysical. Usually a ghost is supposed to be the disembodied spirit of a dead person. Even if many people don't assume that ghosts come to visit earth, they still believe that our souls or ghosts depart our bodies and go elsewhere when we die. As with other assertions of the spiritualist, there has been little offered by way of explanation about how spirits or ghosts are able to operate.
Discussion of ghosts should be sufficient for trying to understand all alleged nonphysical objects since those other objects appear to be very similar to ghosts. If the existence of ghosts is false, the same will be true of the rest of the allegedly nonphysical images. I will proceed through the method of reductio ad absurdum. I will assume that the images we observe when awake are not physical but instead are nonphysical ghosts and consider whether that is a well founded belief.
Common lore has it that ghosts are cloud-like resemblances to the living person from whom they departed. They are thus often described as moving much like bodies, except that sometimes they can move much faster. As bodies, they have a front, a back, and sides; they can appear to be three-dimensional. They are able to laugh, scream, hit objects, and play musical instruments. Sometimes these misty bodies have feet (can their footsteps be heard?), but often they don't have feet and are like clouds that float in the air. They have been known to talk with a human voice. While the living cannot always see ghosts, they sometimes supposedly look like human bodies made of floating white clouds. A cloud that has feet is probably not a real ghost but a human impostor.
The fact is that all the characteristics mentioned are associated with commonly known physical bodies. For humans and other animals to be able to see objects in space means the objects have to be physical, i.e. have bodies. This is the only explanation that has ever been found for the eye seeing something other than in a dream or hallucination. Light reflects off the object and is detected by the eye. Physical bodies are necessary to move about freely. Physical vocal chords are needed to make human vocal sounds like talking, screaming, and laughing.
What could the clouds that comprise ghosts be made of? The clouds most commonly seen are in the sky and are made of water vapor, a gaseous form of water. Alternatively, the ghosts could be made of clouds of smoke or some other gas or combination of gases. Smoke is a combination of gases that are produced by materials that are burned. The exact composition of the smoke depends on the type of material burned. Carbon particles and carbon dioxide are common byproducts of burning. All clouds of smoke are physical entities. They are not normally referred to as objects since clouds and gases are not solid, but they do have a physical composition. They can be thought of as very low density objects until their dispersal in the air carries their constituent particles so far apart they can no longer even be considered a cloud.
Perhaps a nonmaterialist could claim that ghosts are simply made of air, but as any middle school science student knows, air is made of nitrogen and oxygen (about 99%) and about 1% carbon dioxide, argon, helium, krypton, neon, and xenon.( The New Book of Popular Science, Volume 3 (Danbury, Connecticut: Grolier Incorporated, 1982) 189, hereinafter New Book.) All these components are physical elements. All vapors and smoke are made of gases that in turn are made of physical elements or combinations of them.
Given that ghosts look like three-dimensional clouds, move about in space, and have abilities that allow them to perform physical acts like laughing and screaming, it seems they have to be composed of physical constituents whether it be smoke, water vapor, or vapor from a combination of materials. There is no getting around a physical composition for ghosts. If ghosts have to be physical, the same has to be true for all other objects that have a construction of vapor or smoke like that of ghosts.
Two-Dimensional Ghosts
Perhaps, the nonmaterialist would then claim that ghosts look as if they operate in three dimensions but actually only exist in a two-dimensional plane. The appearance of depth or a third-dimension is only an illusion, according to this idea. Many of the same problems in believing in disembodied three-dimensional ghosts are present in the case of disembodied two-dimensional ghosts. While two-dimensional objects or ghosts could reside in three-dimensional space, they may also be able to exist in two-dimensional space. It is at least theoretically possible for there to be a two-dimensional space.
In the abstract, mathematicians have posited and worked on problems in n-dimensional space, where n can be any number they choose. They even work in infinite dimensional space. Vector spaces are types of spaces that have been studied, especially in relation to physics problems. String theorists in physics have come up with the idea that the universe is not composed of three dimensions but more like 10 or 11 depending on which version of the theory is followed.
Ghosts residing in a two-dimensional world could possibly be perceived by living beings as having depth or a third-dimension, but this would be an illusion. It would be akin to a hologram which is a special photograph made on an essentially two-dimensional surface but which exhibits three-dimensional depth. While this two-dimensional scheme avoids three-dimensional space, it is still stuck with the existence of things in space even if it is a different space. It does not avoid the existence of physical objects that are simply flattened out. The objects would still be out in the open for everyone to see suspended in space, even if it was a two-dimensional space. There would still be good grounds for claiming the objects were physical. Otherwise, it would be a dream or hallucination. Besides, the ghosts would still have to be made of something material. As discussed in the case of three-dimensional ghosts, in all past experience there has to be a physical object in space in order for the eye or ear to detect it.
Then there is the question of the composition of these two-dimensional ghosts and other ghost-like objects. Are they made of anything like the molecules and atoms found on this earth? If so, the molecules and atoms themselves would have to be three-dimensional. They do have some depth, even if it is not much. Perhaps, this means that the ghosts would only be one layer deep. They would have regular height and width but only be one layer of molecules and atoms thick (or thin, if you prefer). The depth of these atoms would be so small that raw human senses could not detect them. Instruments such as electron microscopes would be necessary to measure them. Since atoms are individually considered to be three-dimensional, a group of them arranged in a sheet one layer thin collectively would form a three-dimensional object. Ghosts and similar objects existing in alleged two-dimensional space made of regular three-dimensional atoms in actuality would have to themselves be three-dimensional.
The other possibility is that the ghosts would be made of atoms that would be completely flat (whatever that means) and can be arranged in a sheet that is completely flat. They would have height and width but no depth whatsoever. If this is were the case, it would be perplexing how their atoms could perform the operations normally performed by atoms such as striking each other or combining to form molecules. Perhaps, they could do these things because they would be special and different. However different they would be, they would still have to perform all the operations necessary to allow all the ghosts that they comprise to perform the acts they have been claimed to be able to do such as moving and laughing.
Physical existence has not been associated with two dimensions, but then again there has not been much serious study of any objects existing in the second dimension. It is hard to understand how a two-dimensional ghost could appear to look and act every bit like a three-dimensional one. It seems highly unlikely that certain special objects like ghosts would be made out of flat atoms and exist only in two dimensions. It just seems simpler for ghosts to exist as physical clouds in a three-dimensional world like all the rest of us.
Even if a ghost or object exists only in two-dimensional space and is constructed of flat atoms, there would still be a good claim for calling it a physical object. It would still be out in the open for instruments to detect and would still be in a space even if it were not the customary three-dimensional space. Of course, it has been claimed that ghosts can choose who will or will not detect them, but as long as it is possible for them to be detected by more than one living person at a time, they would satisfy the test of intersubjective perception.
A two-dimensional ghost would still be made of atoms even if those atoms were flat, special ones. Remember that atoms are considered as physical. These same arguments apply even in the case that all images were only one-dimensional while appearing to be three-dimensional. They would still exist in the open for several persons, possibly through instruments, to perceive intersubjectively. One-dimensional space and two-dimensional space are subspaces of three-dimensional space. It is hard to see how the material making them up would not be classified as physical.
Projected Two-Dimensional Images
If the images are not three-dimensional or two-dimensional or one- dimensional ghosts, it could be claimed they are projected two-dimensional images. That is, they would not even be made of flat atoms but would instead be dimensionless projections onto surfaces that would make them perceivable by humans. Human experience of two-dimensional images has always been that they have to be placed on some medium. Drawings are made on paper, fabric, wood, or cardboard, among other things. Etching is done on metal, wood, or glass. Painting can be done with color on paper (water color, usually), on fabric, or on canvas. Mural paintings are made on walls that in turn are usually made of stone, masonry, or wood. There are other examples of drawings or paintings that can be put with different types of materials (charcoal, oil paint, etc.) onto different types of physical surfaces.
Moving images are projected using different methods on different materials. Motion picture films and slides can be projected on light-colored walls or on specially made screens. Television, cellphone, and computer images are projected onto a screen. Images placed on these and other surfaces may be thought of as two-dimensional. If we watch a movie projected onto a wall or a screen and go to the screen to touch the images that appear in the movie, we will not feel any solidity of the images themselves. Nor will we be able to walk around the images to see what they look like from behind. All we will be able to do is feel the surface of the wall or screen. We will not detect any effect of the images on the surface. All we will be able to do is see the images with our eyes. If we try to taste or smell them, we will only be tasting or smelling the material that makes up the screen. Any sound the images would apparently make would not come from them but from speakers designed to provide the sound of the film, and those speakers would not be attached to the screen.
From these considerations, it becomes obvious that from our experience all two-dimensional images are found on material surfaces of one form or another. In fact, one-dimensional lines are found on surfaces. The surfaces can be made of many different materials with different consistencies. An image can be made on water or some other liquid from a reflection from something nearby, although it would be temporary. Whatever the surface, however, it has to be made of something and that something is always physical. Furthermore, not only is the surface on which every image is found made of some kind of matter, the image itself is usually made of paint, carbon (from a pencil), charcoal, water color, ink, or some other material that can make marks. Images made by televisions, computers, move projectors, slide projectors, and the like are not permanent. They are made by light falling on the target screen.
Light has a dual nature. It can be considered to be a particle--specifically a photon-as well as a wave. As a photon, it is one of the subatomic particles and is thus considered to be matter. As a wave, it is considered a form of energy. Energy is convertible to matter in accordance with Einstein's famous equation, E=mc2. Furthermore, the instrument that produces the light to make the image is always a material object. The images are recorded on some material medium such as a computer hard drive or photographic film. Thus, the images that we see that appear to have no solidity, that appear to be two-dimensional are nonetheless created using material products through material processes on material surfaces. There seems to be nothing in human experience of two-dimensional images that can get around the involvement of matter, either in the process of creation of the image or as a medium or surface for the display of the image. It is very difficult for someone who might want to deny the existence of physical things to retreat to a world of two-dimensional images. Two-dimensional images are ultimately made of matter and every bit a part of the physical world.
Extra-Galactic Matter
The nonmaterialist may now want to claim that ghosts are made of matter from another world, even another galaxy if you will. Still they act every bit as much like objects made from earth material. They are detectable to the senses. Some ghost proponents have said that electrical instruments here on earth have registered their presence. There has been no credible demonstration of this, as would be expected if it could be done.
Even if the extra-galactic matter were different from that found on earth, it would still be matter. It would exist in three-dimensional space. The elements might just be different from those found here on earth. It would still have to be counted as physical or material substance unless the nonmaterialists could demonstrate that it produced, by itself, the spiritual traits that are supposed to be found in ghosts. The makeup of the ghosts could not depend on any form of physical substance. The nonmaterialists would have to furnish solid proof for their claim of otherworldly spiritual substance. They would also have to explain how the ghosts travel back and forth from their home to here. They would have to overcome the belief of physical scientists that the same chemical elements appear throughout the universe.
Images from Nothing
Perhaps at this point, the nonmaterialist could maintain that the images we perceive are simply made from nothing. There is no need to analyze what they are made of; it won't be possible to come up with an answer since they are made of nothing. To a nonmaterialist the images are just there. At this point, an omnipotent creator could be invoked who makes things out of nothing at all. It is indeed a very peculiar notion that something could be made of nothing. How can something made of nothing count as anything? Doesn't something made of nothing inevitably have to itself be nothing? If Object 1 is on the left and Object 2 is on the right, both made of nothing, how does one tell them apart? How does one distinguish the boundary between them? How does one tell one nothing ghost from another nothing ghost?
In the 1600's, philosopher Gottfried Leibniz proposed the idea of the Identity of Indiscernibles. It was the simple proposition that if two things are indiscernible from each other, then a fortiori they are one and the same thing, i.e. identical. There have been questions ever since on how exactly the principle should be properly formulated, but it at least debunks the claim that a great variety of images with widely varying characteristics could be made of nothing.
Note that in the spiritualist world the perceiver has to also consist of spiritual substance. There has to be an explanation of what processes take place to accomplish perception by a spiritual mind, especially if it is made of nothing. There is no conception of how this occurs and the nonmaterialists give no explanation of it. A similar question has to be asked if there is a spiritual God. Some religions posit this, including Christianity, which holds that one form of God is the Holy Ghost. How is he capable of doing much as a ghost?
The nonmaterialist may want to go further and insist that everything--both physical and spiritual--is made of nothing except for one single spirit who perceives all, like God. It could further be claimed that the entire universe existed in his mind. This would seem to be an arbitrary position stubbornly maintained as a last ditch effort to harshly diminish physical reality. As with the other positions of the nonmaterialist that are hard to conceive, the burden of proof of establishing this idea of nothingness should be squarely on the nonmaterialist.
At this point i will declare that there is insufficient evidence for a special substance called spirit or mind. Everything has to be physical. Even if spirit may appear to be special, it is still dependent on the physical. This refutes the doctrine of spiritualism. It also invalidates dualism, which also maintains that there is spiritual substance. Note that the opposing evidence has not been complex. It has been around for centuries, so materialism should have been accepted as the correct view long ago. The following chapters will present more evidence to confirm that the universe is physical and nothing else.
Descartes' Dream Approach
In spite of all that has been discussed, there is still another possible explanation that the nonmaterialist can cling to. The nonmaterialist may well think that it is not necessary to ponder on how images and objects are associated with matter for the reason that there is simply no such thing as an external world, whether the three or two or one dimensional kind, to which a person looks out. There is simply nothing "out there," not even ghosts. Everything that the mind perceives and experiences is internal; it is all in the mind. The mind itself is supposed to be purely spiritual. The nonmaterialist takes that to show that the images are solely inside our minds.
The scheme is like Descartes imagined it might be at the beginning of his ruminations. He did not simply mention doubt about the existence of objects. He ultimately based his doubt on the possibility that he was always in a dream. In other words, he wondered if what he perceived as his ordinary consciousness was in fact a dream-like state. This would be over and apart from the false experiences he had while asleep and which are normally understood as dreams. It would mean that all objects were made up in his mind.
While we are dreaming in our sleep, we feel no doubt that things are actually taking place just as if we were experiencing them in ordinary life. Everything seems real, and we do not think to question whether events are truly occurring. Likewise, why can it not be that our everyday experience of life, even though it appears perfectly real and permanent, is itself just a dream with all the objects and characters in it just being imaginary items in the dream?
One reason against believing that our ordinary consciousness could be a dream is that it is a very different experience from that found in the sleeping dreams we frequently experience at night. While we are having a sleeping dream it seems perfectly real, but after we wake up, we can compare it with our waking state and notice some big differences. There are many senseless elements in sleeping dreams. The sequence of events is often disjointed and sometimes downright impossible. In the dreams, we deal with people as friends or close acquaintances but, upon waking up and reviewing the dream, realize we have never even met those persons. In dreams we may live in a completely different house in a strange neighborhood in an unknown city and find nothing unusual in that. Sometimes scientific laws are completely ignored; we fly like birds on occasion.
Ordinary experience is much more coherent and predictable in regular waking life. Although life can sometimes be absurd, scientific laws remain consistent, we can keep track of the difference between strangers and acquaintances, and many common daily events follow a regular course. The level of awareness in wakefulness remains the same. In our awake life, we never seem to have any moments in which we "wake up" from our regular consciousness.
There are situations in which our quality of consciousness changes, but they can be readily explained. For instance, there are the times when we are drowsy, somewhere between awake and asleep. It is a different feeling from being in either state--a hybrid between being awake and asleep. It often alternates between the two. At one moment we may be listening to someone talking, the next moment we are in the black of sleep, and then soon we are listening to the person again. Drowsy episodes can occur under ordinary circumstances, or they can take place when we are ill. Another time at which we may notice a different feeling of consciousness is when we have taken a drug. Supposedly, the same hallucinations can be derived from the same drug on different occasions.
Regardless of any number of explanations that could be given for believing that everyday experience is not a dream, there is no irrefutable argument supporting that belief. No matter how certain a person may feel that the objects observed in actuality exist physically and are not a dream, the person could still be mistaken. After all, everything appears perfectly real in an actual dream, so couldn't the same thing be taking place in ordinary consciousness? This all leads to solipsism, which was mentioned before, the idea that i (or you in your case) am the only observer in the entire universe.
Images Inside the MindWe will now examine more closely this last possible assertion by the nonmaterialist: all the images observed as well as the sounds and other sensations are "inside the mind," produced by and for the mind. Yet you are not in a well known dream state. You are fully awake but still there is nothing going on outside your mind. There are no ghosts or anything else outside of you. We will only be referring to what takes place inside your mind. After all you are the one who perceives everything from your perspective. It could well be that every person in your experience is only a construction of your mind and may not actually have a mind. I, the author of this book, may not exist anywhere but in your mind. These pages are just in your mind.
Mind will not be defined here. Chapter 12 will attempt to find an understanding of the meaning of mind. If some of the following discussion seems ludicrous, i ask you to consider that to be due to the claims of the nonmaterialist rather than the fault of the author. In philosophy we respond to all the suppositions.
There are four very remote possibilities as to how the images could be constructed if they are only "inside the mind." The first two possibilities are remote in the extreme. They are that physical objects--either three- or two-dimensional ones--would actually exist inside the mind. The other two possibilities are that (3) neurons or something like them would produce the nonphysical images or (4) they would be nothing.
Physical Objects inside the Mind
A nonmaterialist could concede that the images that exist "inside the mind" are actually physical objects. This would avoid the problem of explaining how objects can possibly exist in a completely nonphysical universe. It would mean then that the spiritualist would actually be a dualist because s/he would be agreeing that at least something was physical. This concession of physical objects would be unlikely but it would still allow the spiritualist to at least deny that there are any physical objects outside the mind. Let us assume for this discussion that the spiritualist does concede that objects literally inside the mind are actually physical.
Physical objects literally inside the mind could be various sizes, depending on the size of your mind. (Your mind would not have to be the same size you think it is now. Realize that we are engaging in a thought experiment here and this gets especially hard on the imagination.) If your mind were the size that you have always taken it to be, all the objects you observe would have to be much smaller than they appear to be in order to literally fit into your mind. (I am assuming your mind to be your brain for now, or at least contained in it.) A man appearing seven feet tall to you would have to be much smaller even though his image would show him to be very tall. Even the earth would have to be small enough to fit in your mind. This would make everything else proportionately tiny. A bird would have to be minuscule.
On the other hand, objects could be the same size that they appear to be. A seven-foot tall man could actually be seven feet tall. Your mind in that case would have to be of enormous size in order to accommodate all the objects that apparently exist. (It might feel good to have a huge mind.) It would seem that your mind would have to be at least the size of the earth to be able to include it. The sun and moon and stars could be imaginary. Or they could be suspended in a firmament like the writers of the Tanakh (Christian Old Testament) thought or located in spheres like the astronomer Ptolemy assumed.
In either of the last two alternatives, the celestial bodies would seem to be a long distance from the earth, and your mind would have to extend far enough to encompass them. They could also be as far away as modern astronomers have estimated them to be, which often involves thousands of light-years. A light-year is the distance light travels in one year at its speed of almost 300,000 kilometers per second. That distance is 9.46 million million kilometers. Your mind would then have to be truly enormous to contain the entire universe. Perhaps, you should only consider it to be the size of the visible universe rather than the possible universe. You wouldn't want to seem presumptuous by claiming it to be any larger.
The actual size of objects is not that important as long as they can adequately be contained in your mind. You have perceived objects all your life that have remained constant in their size, so you have taken that as the "normal" size of things. It is the only way you have ever seen things. Under the scheme in which the entire visible universe is inside your mind, you cannot step outside your mind to inspect the actual size of your mind and the objects in it. It is hard to visualize how this could even occur. Thus it is useless to speculate on the true size of things. For all you know, your mind could be way out of proportion to the objects it holds. It could be immense while the objects are relatively small with much extra unused space. This would leave room for a spreading of the objects.
Apart from the relative size of the objects and the mind, what could be the composition of the objects? If objects in your mind were simply inner versions of the three-dimensional objects outside the mind that were discussed above, the same considerations about physical objects would apply. In order to be detected, objects have to perform particular physical actions like emitting sound or releasing an odor. Light has to reflect from them in order to be visible. In total darkness, they simply cannot be seen.
The mind in turn has to perceive these manifestations from objects in order to detect them. The mind would need physical characteristics to be able to pick up the effects produced by the objects. It would have to be able to see the light coming from the objects that make them visible. In our understanding of the world, sound is produced by the compression of air caused by the source and detected by the ear. The mind would need some mechanism for detecting sounds produced by objects. It wouldn't have to be an ear, but it would have to be some instrument or process.
None of the processes necessary for the mind to be able to perceive the objects in it would have to be the same as what we believe takes place in the world as we think we know it. For instance, the mind would not need to have the aid of two eyes, two ears, and a nose. Instead, it could simply have a "mind's eye." Nevertheless, it would have to have something to perceive and process the sensations emitted by the objects. Whatever the mechanism might be, it would have to be a physical one if it were to process physical phenomena such as light or sound. This invalidates the spiritualist claim that the mind is not physical.
Two-Dimensional Images in the Mind
If there is nothing but the mind, then a second possibility is that all the apparent objects you see as part of a vast universe are actually two-dimensional images inside your mind. This parade of images is all the multitude of events that take place in the universe. It is like the earlier situation considered in which the universe supposedly consisted solely of two-dimensional images, but in that instance, the images were assumed to be outside the mind.
As in that case, how are the images perceptible to the mind if they are not physical bodies of some type? Minds as we know them can only perceive physical things--unless they are dreaming or hallucinating. It would seem then that the images would have to be physically constructed inside the mind. If they were made of the kinds of atoms that are familiar in physics, they would be three-dimensional and so the apparent two-dimensional images would in fact be three-dimensional. All the same considerations that were reviewed in relation to two-dimensional images outside the mind apply here. The two-dimensional images have to be physical.
It could next be claimed by the nonmaterialist that the images don't have any kind of bodies; they are not physical in any sense. The images are simply observed inside the mind. The assertion still obtains that these images have to exist physically in some sense even if they are only in the mind. As mentioned before, matter has always been involved in producing images. Why should it be any different inside the mind? Matter has been involved in providing a surface on which the images rest and in making the images visible to the physical eye. Light has always been involved. One would expect an instrument to produce the images and to project them onto a surface. One would expect some description akin to a material one, or failing that, some explanation why it doesn't work that way.
Perhaps the nonmaterialist would at least concede that the mind is held by a physical brain as is often admitted by those who talk seriously about a separate brain and a separate mind, the dualists. In that case, the brain (your brain remember) would have some special mechanism for showing images to the mind. That mechanism can't be detected, or if detected, understood. Or, what a surprise, the brain may operate just like neurologists and other investigators say it does, except that the images it sees don't come from outside of it. Instead, they appear in some mysterious way and are processed by the physical brain so they can be understood. They are processed in the manner discovered by neurologists with different parts of the brain being involved in different functions like hearing or affection.
Another possible scenario is that your mind is not the only one in the universe. Instead each person in the world could be a separate mind, and the different minds could communicate with each other. Two or more minds could observe the same images in a coordinated fashion, as happens when two people are together in the same room. All the minds could be lined up in a mind warehouse. These would be the only things to exist in the universe, and they would all be physical.
Dreaming Neurons
Consider what neurologists have discovered about dreaming to see what light it can cast on this subject. They usually only refer to the brain and not the mind. Think of the brain and the mind as the same thing. That the brain produces what you are sensing totally within its boundaries is the closest possibility to your being in a dream-state all the time. Assume the only thing that exists in the universe is your brain, and it dreams everything without any physical objects around. There is no need for a three-dimensional space or any other kind of space containing images either outside or inside your brain. The brain has a nonphysical method for producing them. Perhaps that process is similar to that which neurologists theorize takes place when brains produce sleeping dreams. There is presently no complete picture of what that process is, but a number of scientists continue to study it.
Neurologists and physiologists, after many years of studying the brain, particularly while it is in the dream state, have deduced that dream images are generated spontaneously in the brain. During dreams, images clearly do not arrive from outside the body through the eyes since they are closed. Additionally, communication from the retina to the brain is blocked.(J. Allan Hobson, Sleep (New York: Scientific American Library, 1995) 162.)
Images are produced by electrical signals that originate in nerve cells (neurons) in the pons, which is in the brain stem. The images project to the lateral geniculate body in the thalamus, the occipital cortex, and the spinal cord.(J. Allan Hobson, Dreaming (Oxford: Oxford University Press, 2002) 60-64; Sleep 82.) Due to the contact of these electrical signals with these three areas of the brain, they are called ponto-geniculo-occipital (PGO) waves and are electrically measured and recorded in electroencephalograms (ECG). At the same time that PGO waves are observed, "rapid eye movement" or REM sleep takes place, which is closely associated with dreams. Three specific subsets of neurons in the brain stem are active during sleep. They are the midbrain reticular formation and the oculomotor neurons that control the rapid eye movements. These two groups of neurons are also involved in waking. The third group is the medullary reticular formation, which produces complete muscle relaxation (atonia) thus preventing any actual body movement during sleep.(J. Allan Hobson, The Dreaming Brain (New York: Basic Books, 1988) 175.)
Two other groups of neurons work in a complementary manner to bring on rapid eye movement and the dreaming associated with it. The first group of neurons is active during waking, works against rapid eye movement, and releases either one of two chemicals, norepinephrine or serotonin. During sleep, these cells diminish in their activity and this allows a second set of cells to become active and bring on REM and dreaming. After several minutes, the first group of neurons become active again, inhibit the REM-related cells again, and dreaming stops.(Id. 184-202; Sleep 132-137.) These neuromodulatory neurons have been called a "brain-within-the-brain." They are relatively few and are localized in the brain stem.(Dreaming 63-64)
This oscillating activity between these two groups of neurons forms what is called the reciprocal interaction model, which leads to a possible explanation of what happens during dreams known as the activation-synthesis hypothesis. According to this idea, the activation of the cells in the brain stem produces images in the brain that are familiar but usually follow no logical pattern for their production. Areas in the forebrain, particularly the cortex, that are normally associated with memory and vision are also stimulated and appear to be involved in piecing together a narrative out of disparate images and memories. (Id. 205-210; Sleep 145-148.) Allan Hobson and Robert McCarley, research psychiatrists at Harvard Medical School, proposed the activation-synthesis hypothesis after many years of studying dreams.(J. Allan Hobson and Robert W. McCarley, "The Brain As a Dream-State Generator: An Activation-Synthesis Hypothesis of the Dream Process," American Journal of Psychiatry, 134 (1977) 1335-1368.)
A number of questions have to be answered before the hypothesis can be said to be the definitive explanation for what takes place in dreams, but one thing is clear: different parts of the brain communicate with each other by means of neurons, the structural and functional units of the brain.(Sleep 11) There are billions of neurons in the brain with some estimates putting the number at 100 billion.(Henry L. Roediger III et al., Psychology, 2nd ed. (Boston: Little, Brown, 1987) 37.) Neurons do not just exist in theory. They have been detected electrically and have been photographed. (See the photographs, id. 39.)
A neuron consists of a cell body that contains a nucleus and cytoplasm and is physically entangled with numerous other neurons by means of appendages called dendrites and axons. A neuron receives information from other neurons through any one of a number of dendrites that are branchlike fibers attached to the cell body. It transmits information to other neurons by a single axon that can extend several inches from the cell body and joins up with the dendrites of other neurons. The dendrites and axons don't touch each other but instead are separated by a very small gap called a synapse.
The neurons communicate by electrical and chemical means. A neuron always bears an electrical charge that varies depending on whether it has been activated or not. When at rest, a neuron possesses a resting potential of negative 70 millivolts (-70 mv), which is created by ions inside and outside the cell's membrane. The charge inside the cell membrane is negative while that outside is positive, similar to the electrical potential of a battery created by its negative and positive poles that enable it to produce an electric current. Negatively charged proteins exist inside the cell. Among the most important ions, there are negatively charged chloride ions and positively charged sodium and potassium ions both inside and outside the cell body and its axon. (Id. 40). An ion is an atom that has lost one or more electrons and thus acquired a positive electrical charge. Less often an atom gains one or more electrons and becomes negatively charged. (John Gribbin, Companion to the Cosmos (Boston: Little, Brown, 1996) 228.)
Whenever the neuron's membrane detects an electrical charge coming from other neurons through its dendrites, the negative potential of the membrane decreases. This allows the flow of sodium ions across the membrane and that increases the potential to +50 mv. This entire change in voltage takes about one millisecond and is called the action potential. This change in potential cascades down the length of the axon and is called the firing of the neuron.(Roediger 41). It would be simple if the end of the axon were connected to the dendrites of the adjacent receiving cell and the action potential could simply be directly transmitted to it, but there is the matter of those synapses that separate the neurons. Chemical neurotransmitters are the means of traversing what is called the synaptic cleft. They can be either excitatory or inhibitory to the action of neurons.(Sleep 12)
The axon branches into several terminal buttons. When a button receives an electrical signal due to an action potential, it releases a neurotransmitter through the presynaptic membrane of the transmitting cell into the synaptic cleft. The receiving cell has several different specialized receptor sites on its membrane that accommodate different neurotransmitters. Depending on the neurotransmitter and its corresponding receptor site, a receiving cell can be excited into changing its charge into an action potential or be inhibited to stay at rest. Any one neuron can have its dendrites tied to a thousand other neurons so that whether it fires depends on the combined action of all the neurotransmitters it receives.(Roediger 44) There are several neurotransmitters among them acetylcholine, norepinephrine, dopamine, and histamine. (Id.)
Much more could be explained about what is known about the process of dreaming as well as what has been recently discovered of the nature of the brain, but it is clear that it is very much a physical process. It involves electricity and chemical elements and compounds. There is no magical or mysterious action in the actual dreaming that we know. As Hobson stated, "[O]ur so-called minds are functional states of our brains. The mind is not something else--it is not a spirit, it is not an independent entity." (Dreaming 64)
Given all this, it is very difficult to see how your alleged ongoing dream can be anything other than a physical process. The description of regular dreaming as a physical process is strong evidence that any other kind of dreaming, or consciousness for that matter, must be a physical process. It is simply too hard to imagine Descartes' dreaming as being in any way a mysterious phenomenon that was not associated with a physical occurrence. Once again the physical props up its head and cannot be denied.
The final claim could be that the images inside the mind are made from nothing. The images nevertheless exist, and the mind is still able to perceive and differentiate these different nothings. The fact that these nothing images are inside the mind as opposed to outside it does not make the idea that the images are made of nothing any more plausible. The idea of nothings that can be identified from one another is still incoherent. How anything can be made of nothing and still be perceived seems impossible.
Confusion of the Mind
The status of the mind is utterly incompehensible in these possible spiritualist scenarios. There are two basic possibilities for the composition of the mind: nonphysical or physical. If it is nonphysical, it is hard to see how it can observe or contain physical objects or facilitate physical processes like those carried out by neurons. It is even harder to understand what would be its composition. A nonphysical mind with everything else being physical would involve a dualist situation, and it has never been explained how a nonphysical mind can interact with spiritual substances. If it is physical, then that immediately refutes spiritualism.
Then there is the bizarre notion that the entire universe is contained in one mind, which could be in huge proportions or it could be minuscule with everything measured in nanometers. Suppose your mind is the only item in the universe-whether physical or not and whether dreaming or not. That still leaves the huge question of why all the characters you have ever encountered behave and talk as if everything were solidly physical. Why have physicists and chemists studied and discovered the various elements, the physical laws, and the methods for understanding and controlling what has come to be known as matter? Why would the universe mislead all these people to such a great extent? Descartes said he did not believe God would deceive us. Why would God deceive us in this fundamental question--the composition of the universe?
Another puzzling question is why do I need a body in the event the mind is only spiritual? It would seem enough for me to have a mind to observe everything without any need for a body. Yet my mind is apparently always beholding my body as an object. It appears every bit as if I am an object because i can perceive almost all of my body directly with my eyes and my hands and can sometimes smell myself. In Chapter 3 i looked at my whole body in the mirror including my face. People treat me as a commonly seen object, i.e. a typical human being. Of course, if my mind is the only mind in existence, it would probably not be of much use to ask other people if i was an object because they could just be concoctions of my mind and would tell me what i want to hear.
My mind considers me a physical person interacting with the world and appearing as just another one of billions of humans. Why is that? Why can i not simply be a mind completely detached and observing everything or even better controlling everything? I think i could even enjoy being able to, at will, get into the minds (if they have them) of various people and other animals from time to time. Instead, i have to be just another face in the crowd although my mind is the container of everything in the universe.
There is the clear feeling that my mind doesn't control everything. It would seem that it would if it were the only mind. I don't have more control over world events than anyone else (with a few exceptions in world leaders). It doesn't help me much that my mind has the unique status of being the only thing in the universe. To me, my mind has never left my body, yet it would seem to be perfectly free to do that. Perhaps, it does that while i am asleep. That is what it really means to "lose your mind."
The hardest thing for me to understand is that this sole, universal mind of mine that contains the entire universe of physical objects inside it should choose to dwell in, or at least be associated with, my body. I suppose my body should be flattered. It may be just another case of this mind wanting to deceive. Maybe, it lives in all other thinking beings and makes each one of us think it dwells in each of us exclusively. Perhaps this is how the one universal mind of some ancient Indian philosophers actually works. It is very hard for me to adjust to the idea.
Remember the alternative mentioned previously that would avoid the idea that my mind was the only true entity in the universe. That is the conclusion you have to reach if all images are a product of the mind. Each person appearing in my mind's dream could be a separate mind standing on its own and on equal footing with me. The different minds could communicate with each other. Two or more minds could observe the same images in a coordinated fashion, as happens when two people are together in the same room. All the minds could be lined up in a mind warehouse. These would be the only things existing in the universe. They could be physical or nonphysical. Either way they would still communicate with each other.
Chapter Summary
I have tried several ways to account for the appearance of material objects in my field of sensation. I have dealt mostly with my own observations since strictly speaking i cannot speak about the observations of other perceiving beings because if the universe is only made of mind, that mind could well be only my mind. In your case, all this would apply to your mind. I have taken two major approaches: one was to assume that the source of my sensations, what i usually called images, came from outside my mind. There was ample evidence to show that physical objects exist outside of us in space. Even people who report seeing ghosts claim that they exist in space and perceive them as bodies. There can be no bodiless spirits.
The other approach was to take all images as being produced as well as observed inside my mind. Under this scenario, it could be said that there was only one thing that was certain in the universe--my mind. There could not even be any spirits outside my mind. For this to be true, one would have to count all the images in the universe as a product of my mind. In other words, the universe and my mind would have to be one and the same. The proposition that all the images i see (while fully awake) exist wholly inside my mind and represent nothing outside it is frankly preposterous. If these images did exist, they would surely have to be made of some material that could be shaped into distinguishable entities in order to be able to tell them apart. Whether they are outside or inside the mind does not obviate that requirement. If the mind is the brain, itself a physical object, then it would have to produce images by chemical compounds. That means standard physical processes would construct them.
Whatever way it is examined, there is little credible evidence for the idea that images are nonmaterial (nonphysical) and that the universe is totally spiritual. Furthermore all this disproves the idea that there are any spirits intertwined in the physical world, the position of dualism. It is an unavoidable conclusion that the images we perceive, including ourselves, are physical objects. They are pervasive throughout the universe and are certainly not to be ignored or disparaged. This is well founded in light of what technology has accomplished in the last two hundred years by manipulating and transforming physical objects. The following chapters will review this development in science as further evidence for physical reality.
Metaphysics has too many times failed to pay close attention to the findings of science before the formulation of its doctrines. Metaphysicists have often excused this on the grounds that the two disciplines are vastly different, that metaphysics deals with concepts that may be used by scientists but are not questioned or evaluated by them. Conceptual analysis is supposed to be the area of expertise of metaphysics. Metaphysics studies questions like the one examined in the last chapter: are there any physical objects? Scientists assume that physical objects exist and go on from there. They are allegedly puzzled by anyone wanting to spend much time on what seems to them plainly obvious.
Reliance on Science
While there are differences in the approaches taken by the two disciplines, metaphysics often relies on the findings of science. The physical nature of the universe and the existence and function of atoms have been considered by metaphysicists. This practice goes back to the pre-Socratics. In more recent times, philosophers have studied quantum mechanics and the theory of relativity in physics.
An example where metaphysicists have not taken sufficient account of scientific knowledge has perhaps been in the area of philosophy of mind. More attention to neurology has been needed.(Patricia and Paul Churchland have been more attentive than most to neurology. See Patricia Churchland, Neurophilosophy (Cambridge, MA: MIT Press, 1986)). A famous example of a philosopher who did not go far enough in his scientific investigations is Descartes, even though he was a great pioneer in encouraging scientific observation and especially in using mathematics for the deeper understanding of facts. In his observations of the minds of animals, he was too hasty in his conclusions that they had no capacity for thinking or communication but were instead not much better than machines.(Descartes, "Discourse on Method," reprinted in The Rationalists (Garden City, New York: Dolphin Books, 1960) 81-82.)
If he had taken more time to observe animals, he might have observed that they can sometimes solve simple problems and engage in rudimentary communication. It might have helped if he had simply consulted with observant pet owners. He might have learned that cats and dogs can learn to open doors on their own, that cats apparently use reason in climbing up and down trees, or that some birds use a variety of songs for giving signals to other birds. It has recently been discovered that some monkeys use a spoken language with numerous names for different objects and animals.
Of course, it is unfair to judge Descartes by standards other than those applicable in his time. It is a good bet that his contemporaries, even educated ones, had a low opinion of the mental ability of animals, but even then one wonders how many went as far as Descartes in considering them to be no more than machines. Clearly, Descartes' judgment was influenced by his overriding desire to prove the existence of a soul that was exclusive to humans. For animals to possess even the semblance of a soul would somehow be demeaning to humans. Unfortunately, too many humans have sympathized with this view to the detriment of animals.
Relevant Scientific Issues
A review of the present status of knowledge in all areas of science would be beneficial in formulating a sound metaphysical system. However, a complete review would be impractical since it would involve covering an immense amount of information known today in a large number of scientific areas. Within those fields, there are branches that themselves constitute sizable bodies of knowledge. In physics, there are classical mechanics, thermodynamics, electricity, magnetism, optics, solid-state physics, nuclear physics, particle physics, quantum mechanics, relativistic mechanics, biophysics, and conservation laws. Biology contains the branches of zoology, botany, anatomy, physiology, cytology, embryology, ecology, genetics, morphology, molecular biology, and neurology. These are just two of the sciences.
Obviously to cover all the subjects of science would be an extensive undertaking under any circumstances. To be done thoroughly, it would have to be done by a number of scientists each with an expertise in a specific area. While such a project could yield some benefit, more likely it would involve much more of a review than is necessary for the purpose of formulating a metaphysical system.
A more realistic approach is to do a narrow review of a few topics that would cast light on the relevant philosophical issues. There is no guarantee that the facts found in these scientific areas will answer the related philosophical questions beyond a doubt, but if they at least cast some light, the quest is worth pursuing. Scientific findings have penetrated so far that it is doubtful that any future discoveries would bring great change to the philosophical picture of the universe proposed here. The scientific details to be covered in the next few chapters are interesting, but you will not need to remember the details. It will be beneficial if you just get a good sense of the extent of the knowledge of nature today.
A traditional search in philosophy has been to try to determine the composition of material objects. The pre-Socratic philosophers conjectured that everything was made of a very few basic constituents. Since then, physicists have gone a long way in finding more basic, intricately arranged constituents. What they have found will be examined but only on a very basic level. Physics will first be consulted to learn something about the smallest constituents of matter. Several other sciences will then be reviewed to get a fuller picture of the nature of the universe.
Physics: The Smallest Things
Humans have always been curious about the nature of the smallest bits of matter. Specks of dirt and pieces of lint are some of the smallest objects visible to the naked eye. It is easy to make the conjecture that such objects could be subdivided even more, to the point where they would not be visible. Leucippus and Democritus seemed to think so. After they posited that everything was made of invisible, indivisible atoms, there was not much progress made in supporting the idea for more than 2,000 years.
Lucretius, a Roman poet of the 200's B.C.E., was an admirer of Democritus and Epicurus and wrote the long poem DeRerum Natura in which he provided various arguments for believing that atoms make up everything in the universe. The book caught the attention of many readers but did not inspire widespread belief in the existence of atoms. That was still the situation in the 1600's when Isaac Newton expressed an opinion on their existence even though he did not engage in specific research on them. He was prescient about the structure of the atom. He not only thought that atoms existed and formed chemical bonds with one another to form ordinary objects, he also expressed belief in two levels of subatomic particles which is consistent with what has been found to be the case.(Hans Christian von Baeyer, Taming the Atom (New York: Random House, 1992) 13.)
In 1738 Daniel Bernoulli explained how the motion of atoms striking the walls of a closed container accounted for the pressure felt against the walls. His mathematical calculations describing how the pressure of a gas was inversely proportional to the volume of the enclosing container were widely accepted. Still there was a reluctance to adopt belief in the reality of atoms.(Id. 15)
In the early 1800's, Englishman John Dalton devised a system of notation for keeping track of the growing number of elements that were being discovered. He believed that each element was uniquely represented by a type of atom with specific characteristics. Many contemporary scientists did not share Dalton's literal belief in atoms. That skeptical attitude remained through the 1800's. Scientists talked about atoms during that time but thought of them only as a convenient fiction.(Id. 16.) Reference to atoms was made as a practical and useful aid, but any judgment on their actual existence was withheld. Perhaps the main reason for this reluctance was the belief that until atoms were observed directly they should not be considered real.
Ernst Mach, a highly respected physicist in the late 1800's, was one of those who were very reluctant to accept the existence of anything that did not rest on direct sensations. He was also an influential philosopher of science who was later carefully studied by the Vienna Circle. Mach and like-minded scientists wanted to be careful to avoid agreeing to the existence of entities on weak grounds or what they considered metaphysical suppositions. Mach's most enduring contribution to philosophy was his steadfast suspicion of anything "metaphysical." ("Mach, Ernst," The Cambridge Encyclopedia of Philosophy, 1995 ed.) This scientific skepticism is certainly constructive in avoiding hasty claims about what should be considered scientific fact.
By the end of the 1800's, the actual existence of the atom was well accepted by the scientific community,(von Baeyer 18) but the atom was not able to enjoy undisputed reign for long as the smallest thing in the universe. In 1897, Cambridge physics professor Joseph John (J.J.) Thompson was studying rays that could be produced in a glass tube from which most of the air had been removed. The tube contained a highly charged negative metal plate and a positively charged plate. The rays flowed from the negative plate (called the cathode) to the positive plate (called the anode). The rays were called cathode rays and could be affected by a magnet. Thompson measured the deflection and concluded the rays were negatively charged.(Kenneth W. Ford, The Quantum World (Cambridge, Massachusetts: Harvard University Press, 2002) 31.)
Thompson decided to further investigate the cathode ray particles. He could measure the ratio of the mass of the particles to their charge and compare it to the same ratio for a hydrogen ion. An ion is an atom with a positive charge because it is missing an electron. Using these measurements, he was able to deduce that the mass of a cathode ray particle was much smaller than that of an atom. We now know that this cathode ray particle was what was later named the electron.(Id.) For this discovery, Thompson received the Nobel Prize in 1906 and launched the new field of particle or subatomic physics.
The hydrogen ion is actually a proton that is about 2000 times the mass of the electron.(Id. 251) The name cathode ray is no longer used by physicists but has remained associated with the cathode ray tube (CRT) that was used for many years to provide the images in televisions and computer monitors.
Inside the Atom
To get an idea on the size of an atom, a million atoms lined together are no wider than a period on this page.(Robert M. Hazen and James Trefil, Science Matters (New York: Anchor Books, 1991) 55.) By 1932, it was known that the atom contained a nucleus that was composed primarily of protons and neutrons and was located in the center. The nucleus comprises 99.9 percent of an atom's mass but only a trillionth of its volume.(Id. 56) Electrons weigh only about 1/1860th of a proton or neutron. Atoms are made almost entirely of empty space between the nucleus and the electrons.(Id. 58) Each proton has a positive charge of +1, and each electron has a negative charge of -1. Neutrons do not have any electrical charge, so the protons have to be equal in number to the electrons in order for an atom to remain electrically neutral.
In 1913, physicist Niels Bohr came up with a description of the atom that suggested a similarity to the solar system with the nucleus in the place of the sun and the electrons circling around it in the manner of the planets at a great distance away. This picture became etched in the popular mind and is still used today to depict the atom. Also the popular conception has remained that an atom is comprised of protons, neutrons, and electrons and nothing else. In 1934, these subatomic particles along with the electron neutrino were considered by physicists as the "fundamental" or "elementary" particles. Democritus and Dalton had been wrong. While atoms were the smallest constituents of elements and were relatively free to move and bind with each other, they were not the smallest objects. There was another level below them. As physicists continued to study the atom, they continued to find a more complicated situation than had been expected.
More Subatomic Particles
The next thing discovered by physicists was that there was a whole world of antiparticles. The antielectron has a positive charge of +1, equal in magnitude but opposite in charge to the negatively charged electron. It is usually referred to as the positron. Every particle has an antiparticle, except for a few neutral particles. These are also said to be their own antiparticles.(Ford 35)
By now, hundreds of subatomic particles have been found. Many of them are composite particles, and many are unstable, meaning that they exist for only a small fraction of a second. There are so many more particles than originally expected that they have been named the "particle zoo." It seems there are twenty-four particles that are not composed of smaller particles and so can be called fundamental. These twenty-four do not include the corresponding antiparticles and the hypothetical graviton that is thought to carry the gravitation force.
The fundamental particles are divided into two main groups: fermions that compose all the matter found in the universe and bosons that carry the forces that allow the fermions to interact. The fermions can be thought of as the matter particles and the bosons can be thought of as the force particles. Fermions have rest mass as well as gravitational mass that allows gravitational attraction. Some bosons do not have rest mass. Fermions include six quarks and six leptons.
Quarks and Company
The six quarks were given unusual names in the 1960's, which were Up, Down, Charm, Strange, Top, and Bottom. There are six leptons: electron, muon, and tau. Each one has a neutrino associated with it such as the electron neutrino. Then there are the twelve known bosons with their associated forces.
Bosons
Particle --- Associated Force
Photon --- electromagnetic
Gluons (8) --- strong nuclear
Weak gauge bosons(3) --- weak nuclear
Graviton(?) --- gravitational
What happened to the protons and the neutrons that make up the nucleus of the atom? Along the way, it was discovered that they were made of the smaller quarks. The name quark was first applied by Cal Tech physicist Murray Gell-Mann, which he got from a phrase from Finnegan's Wake by James Joyce. The names for the quarks have no relation to their properties; they were chosen whimsically.
Cooperative Quarks
No quark has ever been found to exist alone, only in combinations of two and three. Two up quarks and one down quark make up the proton, while the opposite configuration, one up quark and two down quarks make up the neutron. These two quarks plus the electron and the electron neutrino make up all the atoms that constitute ordinary matter.(Gribbin 335) Quarks and antiquarks have only fractional electric charges of either +1/3, -1/3, +2/3, or -2/3 and then combine in such a way that their composite particles balance out to have zero or unit charge.(Ford 69)
Like a number of other things in the subatomic world, quarks exhibit unexplained characteristics. It is difficult to assess their masses (because they are so small). The heaviest one is 60,000 times larger than the smallest one.(Id. 67) Quarks have other properties such as spin, color, and baryonic number.
There are hundreds of composite particles made up of various combinations of quarks, but they are not normally found on the earth. They either come to the earth from outer space as cosmic rays or are produced as a side effect of experiments by physicists using particle accelerators such as the two-mile long Stanford Linear Accelerator (SLAC). Accelerator-produced particles have a very short life, only a tiny fraction of a second. The accelerator creates them by the smashing of atoms by particles. A similar process takes place in cosmic radiation. Most cosmic radiation is protons. They collide with the nuclei of atoms in the earth's atmosphere and produce numerous other particles, most of which never reach the earth's surface. Most of the charged particles that reach the ground are muons. They arrive constantly along with trillions of neutrinos.(Id. 45)
Bosons: Force Carriers
Atoms and particles interact with each other, but they don't do this through a simple matter of bumping into each other or by gravitational attraction as one might imagine. This is where bosons come in. They are particles that are force carriers. All microscopic interactions take place through the creation or annihilation of particles. For instance, electromagnetic attractions are possible through the creation or annihilation of photons.(Id. 43) Quarks are joined together by gluons that carry the strong nuclear force. This force also keeps protons and neutrons together. The weak gauge bosons carry the weak nuclear force. It is estimated that a particle named the graviton could carry the gravitational force, but it has not yet been detected. In the 1970's, the electromagnetic and weak nuclear forces were shown to be similar enough to be considered the same force, called the electroweak force.(Id. 76-77) Physicists have tried to search for a single unifying force that stands behind all the forces in a grand unified theory (GUT).
Electronic Action
Electrons in orbit around the nuclei of atoms exhibit interaction with photons every time they move to a different orbit. The orbits around the nucleus have precise energy levels. When an electron moves to a different orbit, it releases or absorbs energy. If an electron moves to an orbit that is closer to the nucleus, it gives up energy by emitting a photon.(Hazen and Trefil 60.) If instead an electron moves to an orbit further away from the nucleus, it absorbs a photon and thus gains greater energy. The energy of the photon absorbed or emitted is precisely equal to the difference in energy of the two orbits involved. There is never a gradual and continuous release or absorption of energy when an electron moves to a different orbit. Nor does the electron gradually traverse the space between the orbits, as we would expect because that is the way we observe things take place in everyday experience, i.e. in the macroscopic world.
Instead, the electron makes a "quantum leap" from one orbit to the other, disappearing in the first orbit and reappearing in the second orbit.(Id.) The accompanying photon accounts for the energy involved in the transaction, which satisfies the law of the conservation of energy. The orbits in any one atom always maintain the same discrete energy level and can accommodate only a specific number of atoms depending on their location in the atom. The orbit closest to the nucleus has space for only two electrons. The second and third orbits can hold no more than eight electrons each.(Id. 63)
The mathematical theory that describes the interaction of electrically charged particles such as electrons through the exchange of photons is known as quantum electrodynamics. The process involves the appearance and disappearance of what are called "virtual" particles. These particles are created from the energy around them and then very quickly give up their energy and disappear. QED theory integrates quantum mechanics and the theory of electromagnetism. QED's fantastic idea of virtual particles has received a very high degree of experimental confirmation. (Bryan Bunch, Handbook of Current Science and Technology (Detroit: Gale, 1995) 650.)
The Inception of Quantum Theory
Quantum mechanics is a very important and comprehensive theory of what takes place inside the atom. It is difficult to understand partly due to its mathematical rigor and partly because it has still not given scientists a satisfying visualization of what goes on, especially in regard to the movement of the electron. Yet since its inception in 1900, quantum theory has proven very successful through the many accurate predictions it has provided and is thus universally accepted among physicists. There are no serious competing theories, but there is abundant confusion and a subsequent variety of interpretations of what is going on in the actual space occupied by the atom. The mathematics involved doesn't provide a satisfying intuitive picture.
The central ideas in quantum theory are that (1) in the subatomic area, including energy, everything appears in discrete bundles or "quanta" rather than in any continuous flow or stream, (2) particles are also waves (wave-particle duality), and (3) there is an unavoidable uncertainty in the measurement of subatomic entities.
Quantum theory began in 1900 when Max Planck tried to get a better understanding of how energy was emitted from a closed container as its temperature varied. He discovered that the formula E=hf fit the results accurately. E is the energy, f is the frequency of a vibrating charge, and h is the constant of proportionality, which is now known as Planck's constant.(Ford 95) Planck was perplexed on how the formula could work until he postulated that the energy was radiated not in a continuous flow like running water but in discrete lumps that he named "quanta."
In 1905 Albert Einstein offered an explanation for the photoelectric effect by assuming that light traveled in light quanta (later renamed photons). He won the Nobel Prize for this explanation. Before Einstein's use of the idea, physicists had been confident for many decades that light traveled in waves. However before that, it was thought that light traveled in particles, or corpuscles as they were called then, based on studies by Isaac Newton. Yet a contemporary of Newton, Christian Huygens, had developed a complete wave theory of light.(Gribbin 215) Nobody thought light could consist of both waves and particles at the same time.
Wave-Particle Duality
One of the controversial features of quantum theory has been its inability to resolve the question of how light can consist of both particles (photons) and waves at the same time. Instead, it has been necessary to assume that light comes in both forms although each has a very different appearance and properties. It was further found that not only light but also electrons, x-rays, and other electromagnetic phenomena exhibited this wave-particle duality.
The classic way it has been shown that light has a wave nature is by the double-slit experiment. Thomas Young performed an early version of this experiment in England in 1802. A light is directed at two narrow, vertical, closely spaced slits in an opaque sheet. A second detecting sheet is placed behind it. One would expect to have two corresponding vertical bars of light appear on the detecting sheet separated by a dark bar, corresponding to the two slits and the space between them on the first sheet.
Instead, an array of equally wide, alternately placed vertical light and dark bars appears on the second sheet. This shows that the light coming out of the two slits toward the screen travels in two sets of waves traveling side by side. The light bars are the places where the two different waves strike the sheet in phase with each other--crests lined up with each other and troughs lined up with each other. They reinforce each other. The dark bars are the places where the waves strike with the troughs of one canceling out the crests of the other. They destroy each other. All this is consistent with the way other types of waves interact--water waves, sound waves, etc. Experiments with electrons show the same results albeit on a special screen that can detect them.(See drawing in Ford 195) The wave-length of the particle can be calculated from the distance between the two slits and the distance between the bars on the detecting sheet.
The same experiment conducted with very slow photons or electrons brings an astonishing result in quantum physics. A single particle, say a photon, is fired at the two slits at one time. In this experiment instead of a detecting sheet, there is an array of detectors that signal the arrival of a single photon. The first photon that is sent hits at some unpredicted point on the detecting screen. The same will be true of the second photon that is sent after the first one. The pattern that emerges after the first few photons is one that shows them arriving randomly. After about 10,000 photons have hit, however, alternating light and dark bars appear just as in the case in which multiple photons are sent in the form of a beam of light. The dark bars here represent the areas where the photons landed, and the light ones the places where no photons hit. The bars indicate that the photons traveled as waves. Each photon was created as a point and arrived at the detectors as a point but between the two events acted as a wave. Each photon passes through both slits.
This action demonstrates the wave-particle duality of individual particles. The same one-at-a-time particle experiment works for the electron. The explanation is consistent with quantum theory and with various other experiments.(Ford 196) It is amazing, to physicists as well as nonprofessionals, to see that a particle can pass through both slits as a wave. Its locality cannot be pinpointed between its travel from the source to the detector because the wave is spread out. This is the quantum property of nonlocalizability of waves. It makes it very hard to find the location of any given electron in an atom.
This and other aspects of quantum mechanics are so puzzling to quantum physicists that Richard Feynman, one of the creators of quantum electrodynamics, for which he shared the 1965 Nobel Prize said, "My students don't understand it either. That is because I don't understand it."(Richard Feynman, QED (Princeton, New Jersey: Princeton University Press, 1985) 9.) He had as much knowledge as anyone of quantum theory and was also highly respected as a teacher. Feynman commented that the action of electrons in the one-at-a-time particle double slit experiment was the central mystery of quantum theory.(Gribbin 333)
In 1925, Werner Heisenberg formulated a version of quantum theory based on the mathematical subject of matrices. Heisenberg's theory was correct and accepted by other physicists, but he believed it could only make sense in a mathematical manner. He did not think it was possible to understand what particles were doing in a physical sense. It could not be visualized.
Particular Uncertainty
Two years later, Heisenberg announced the now widely known Uncertainty Principle that introduced further puzzlement into physics. The principle, which is based on mathematics and not mere conjecture, enunciated that the position and the momentum of a subatomic particle cannot be known with certainty at the same time. If an experimenter wants to measure the position of an electron precisely, it will be impossible to take an accurate measurement of its momentum. If it is necessary to take an accurate measurement of momentum, it will not be possible to know the position accurately. This is not a matter of inadequate instruments. It is a principle that derives from the nature of the quantum world and is related to the superposition of different wavelengths. The principle applies to other pairs of related physical quantities, like time and energy and time and frequency.
In 1926, Erwin Schrodinger came up with a wave equation that described a particle such as the electron in a hydrogen atom. He and other physicists did not understand what it represented about the electron in a physical sense. Max Born offered two explanations. The first was that the wave function, labeled Ψ (the Greek letter psi), was an unobservable quantity. Second, the observable quantity was the square of the absolute value of the wave function, |Ψ|2, and was to be interpreted as a probability.(Ford 204) Born offered no physical picture of the electron, only an interpretation of the mathematics describing the action of the electron, which was gradually accepted by physicists, although with much perplexity.
To this day, the mathematical description that began in the 1920's is still accepted. The location of a given electron in an atom cannot be pinpointed at any one time. The best that can be done is to assess the probability that it will be at a location at any given time. In similar fashion, it cannot be specifically predicted when an electron will change energy states as it moves around the nucleus of the atom.
Only the probability that an electron will change energy states is the same as what is also called changing orbits, but to talk of electrons moving in any kind of a smooth, regular orbit around the nucleus is probably inaccurate. It is not clear how they travel around the nucleus. They apparently travel in wave-like fashion, and that makes it difficult to visualize their paths since waves can take many different forms and spread out significantly.
Superposition
A very perplexing aspect of quantum theory is that of superposition and measurement. Because of the wave nature of subatomic particles and the probabilistic association of a particle with a wide array of wavelengths, the state of a particle can be described by a mixture--a superposition--of different states. One expects that an electron circling an atom's nucleus has a definite energy or definite momentum at every instant, but under quantum theory the electron has a great number of different momenta corresponding to the different superposed wavelengths. This does not mean that the electron has one momentum among many possibilities and that the laboratory scientist finds the correct value of the momentum once she takes a measurement. In quantum theory, the electron has all the different momenta at once.
That situation remains the case and changes only if and until a measurement or an interaction with a large object takes place. Once that happens, a precise value for the momentum is manifested and only then does an exact value appear. Before that, there was only a known range of probable values that it could become. This is another unusual feature of quantum mechanics.
The subatomic particles do not possess specific values such as momentum in their normal everyday perambulations wherever they may be. It is only after an interaction with a macroscopic object like a measuring instrument that a value is set. Before that moment, it appears that particles simply will not commit to specific values. The best a scientist can do is to assess the probabilities that particular values will turn out to be the correct ones. The different probabilities are represented by different waves, and the measurement that brings out a specific value is referred to as the "collapse of the wave function."
Quantum Entanglement
The last strange feature of quantum theory that i want to mention is entanglement, which is simply a form of superposition in which two or more different systems become separated. Two different systems can be atoms actually superposed in space or two photons created in a superposed state by a disintegrating radioactive atom. If the pair of photons has a total spin of zero, each photon must always have a spin that is opposite to the spin of the other. In one of the superposed states, the first photon has its spin up and the second photon has its spin down. In the second superposed state, photon #1 has spin down and photon #2 has spin up. There is no actual spin of the photons until at least one of them is measured or engages in interaction outside the system.
Assume that the two photons are created by a radioactive atom and are then separated and travel several city blocks apart. If a technician detects the first photon and finds that its spin is down, then a second technician stopping the second one several blocks away will always find that it has an up spin. The spin of the two photons will always be opposite. The experiment or something similar to it has been conducted many times and the spins of the particles have always been opposite even though this would not be expected because they have always been far apart. Particle physicists are at a loss how to explain this seemingly coordinated action by the superposed particles acting at a distance. Einstein never believed it actually took place, calling it "spooky action at a distance."
Nonlocality
The experiment with the two separating particles exhibits an aspect of quantum theory known as nonlocality by which particles show coordination with each other even though not located close to each other. Before quantum phenomena were discovered, physical action always appeared to take place in proximate areas. Things acted locally. (One notable exception was the action at a distance of gravity across the planets of the solar system. Newton discovered the universal law of gravitation and that it applied to celestial objects but was hard put to explain satisfactorily how it could actually work at large distances.)
An experiment (or one like it) to show nonlocality was first proposed in 1935 by Einstein and two of his colleagues at the Institute for Advanced Study at Princeton. For them, it was only a thought experiment and was not tried out in a laboratory. It showed that based on quantum equations, two particles created together and then separated by a wide distance would continue to always act in coordinated fashion as if they had never been separated. Einstein thought this was absurd and that it showed that quantum theory had to be wrong. It became known as the Einstein-Podolsky-Rosen (EPR) Experiment or Paradox and contributed to many lively debates for years to come between critics and defenders of quantum theory.
In 1964 John Stewart Bell came up with a way to test whether particles could engage in a coordinated manner at a distance. His idea is known as Bell's Theorem or Bell's Inequality and is similar to the proposed EPR experiment. Years would go by before the technology became available to perform his experiment. In the 1970's, the experiment was conducted more than once and showed that Einstein had been wrong to scoff at quantum mechanics. Partner particles were found in coordination even after being separated by many meters.
Quantum theorists are confident this would still be the case even if the particles were to become separated light-years apart in space. Imagine a hypothetical experiment in which two particles were created on earth and then separated. One would stay on earth, while the other one would be dispatched to a planet two thousand light-years away where a native extraterrestrial physicist would agree to measure it. It is believed that once the earth physicist measured the photon that stayed on earth and determined, for instance, that its spin was up, the planetary physicist would detect that the spin of the emigrant particle was down and this would happen concurrently.
Of course, there would be a big problem in the time taken for communication between the experimenters. Even if the communication were to take place at the speed of light, for example, through two-way radio somehow, it would take two thousand years for each message to arrive. In 2018 a team of Viennese scientists used a space observatory on the Canary Islands to conduct an experiment involving two quasars vast distances apart in space that they claimed also confirmed nonlocality.
Everyday Perception
Physicists have found it hard to reconcile quantum theory with the everyday perception of how things work in the ordinary physical world with which we are all amply familiar. The subatomic world simply follows a number of rules that are different from those controlling larger objects, and it is for this reason thought of as absurd or weird.
This is referred to as the distinction between the microscopic world and the macroscopic world or between quantum physics and classical physics, the latter being all the subject matter of physics before 1900. The main subjects covered in classical physics are mechanics, thermodynamics, optics, sound, electricity, and magnetism. Since its birth in 1900, quantum physics has become so well established that it could now also be considered "classical." The distinction is perhaps better made between prequantum and quantum physics or between the subatomic world and the atomic world, the latter including atoms and everything larger.
Two of the main founders of quantum mechanics, Planck and Einstein, were two of its biggest doubters. Planck was never comfortable with the idea that energy was transmitted in bundles rather in a continuous flow like a liquid. He tried all his life to reconcile quantum physics with the old familiar physics but never found a way. Neither man could accept the idea of wave-particle duality. It seemed that everything in nature had a clear and definite appearance and did not vacillate in chameleon-like fashion (chameleons being an exception). There was the problem with when a subatomic entity was a particle and when it was a wave. This was not easily ascertainable; it was always a matter of probability. Where an electron was located in an atom could only be approximated using probability before it was actually measured. Once there was a measurement, a location could be specified.
Even the supporters of quantum physics have expressed bafflement at how it is so different from our experience of common objects. Niels Bohr was another one of the founders of quantum mechanics. What has developed as the standard model of the atom is sometimes called the Bohr atom, and the most widely accepted interpretation of quantum mechanics is called the Copenhagen interpretation. Bohr worked most of his life in Copenhagen, Denmark, where he was director of the Institute of Theoretical Physics until his death. He stated, "If someone says that he can think about quantum physics without becoming dizzy, that shows only that he has not understood anything whatever about it."(Murray Gell-Mann, The Quark and the Jaguar (New York: Freeman, 1994) 165.)
Alternative Interpretations
The confusion and perplexity presented by the Copenhagen interpretation has not been accepted complacently. Some physicists have devised alternative interpretations that have eliminated some of the quirks but have still not succeeded completely in painting a coherent picture. Sometimes the new approach has been even more strange than the Copenhagen one.
One such example is the "many worlds" interpretation proposed by Hugh Everett. While this approach did simplify some aspects of the Copenhagen approach, it had a very strange result--each time a quantum interaction took place an entirely new universe would be created. This creation of universes could repeat itself many times. One claim was that "parallel universes" were made. Unfortunately, this many worlds interpretation was greatly sensationalized by numerous authors, not only science fiction writers but even physicists who have written books touching on quantum physics. The interpretation is not so outlandish. A more fitting label would be "alternative histories." All histories are treated alike but have different probabilities. It is not necessary to believe in different parallel universes, all equally real.(Gell-Mann 138) Regardless of the name, there are still many questions that need to be worked out.
Another well-known interpretation is the deBroglie-Bohm hidden variables interpretation. David Bohm worked on developing this interpretation because as a Marxist he was not comfortable with the probabilistic picture of the universe. The hidden variables have not been found to this day, and the double-slit experiment with an oil droplet has cast doubt on it.
It seems funny that Einstein along with other physicists had a hard time accepting the results that seem to follow from theory and experiments in the quantum realm but had no trouble visualizing the nature of space-time in the physical world. Physical scientists readily accepted the notion from Einstein's general theory of relativity that gravitational attraction between objects occurs due to the "curvature of space-time" caused by the objects. There is no doubt that from a mathematical standpoint this is a good description of what happens, but it would seem to be far removed from everyday observation. It seems odd that there is no better explanation that can be readily visualized.
Need More Study
To this day there is no doubt among physicists--to say nothing of lay people--that there is much left to understand about quantum theory. Specialists in quantum theory continue to try to clarify what is taking place but without great success. There are two important possible explanations for why quantum theory seems so unclear. One is that particle physicists simply have not uncovered enough of the facts of the subatomic world. The theoretical physicists need to know more about how particles interact and whether there are more particles. If there are more particles, are they significant in connection with quantum theory? Experimental physicists need to make these findings but have been stumped by the lack of sufficiently powerful particle accelerators or colliders that can create the high speeds necessary to detect new particles as a byproduct of particle collisions. Perhaps once a fuller picture of the particle domain is acquired, the results won't seem so odd.
The more intriguing possibility is that the quantum reality that has gradually become the norm over more than 100 years is actually the most accurate view of the world that physicists will ever lay out. This would mean that the discrepancy between quantum theory and the human perspective would not derive from a defect in the theory but rather from shortcomings in our perception.
An Evolutionary Standpoint
It could be that our ability to obtain a satisfying view of all aspects of the universe simply falls short. Our ability is sound in connection with the objects we need to regularly manipulate in the world like tasting water or throwing a stone or assessing the fragrance of an edible plant. We don't even have trouble examining otherwise invisible objects like amoebae or even atoms through a high-powered microscope. We don't, however, engage much in peering at subatomic particles. In fact, this has never been done. The best particle physicists have been able to do to track the path of particles and then to record the traces of their action on photographic film.
From an evolutionary standpoint, this inability is readily understandable. Our human ancestors, as well as our animal ancestors, never had a need to examine subatomic particles in the jungle or in the forest. Biologists believe that evolution has taken place through natural selection of those traits that appeared in a species that tended to favor survival and continued reproduction.
The ability to perceive things working in the subatomic realm was simply not a necessary one for those living in a primitive environment. Instead they had to concentrate their every effort on survival and the basic needs of living. These evolutionary calculations help explain why it is so hard for humans to accept what goes on in quantum mechanics. Perhaps if we had the ability to observe quantum actions and were familiar with them from 300,000 years ago, it would not seem so strange.
Accepting All the Physical World
Even then, the question could still be asked: Why is there such a disconnect between quantum entities and the larger objects they make up? Leptons and photons appear as both particles and waves unlike anything seen in everyday observation, thus defying what we consider sound logic. Aristotle long ago posited the Law of Excluded Middle: either the thing A exists or it doesn't, there is no in between. This has been widely accepted, but it doesn't appear to always apply in the quantum area. Logicians have developed consistent, many-valued logic systems in contrast to Aristotle's two-valued logic.
The opposition to quantum mechanics appears not to be a disagreement based on evidence or consistency of results. The theory has been supported over and over again through experiment. Most physicists have just learned to accept it and dealt with it like the renown physicist Isidor Rabi who told Gerald Edelman, "Quantum mechanics is just an algorithm. Use it. It works, don't worry."(Gerald Edelman, Bright Air, Brilliant Fire: On the Matter of the Mind (New York: Penguin, 1992) 216.)
The opposition has been based more on anthropocentric prejudice against something that does not appear familiar to human observation. There is no reason that the universe should be fully comprehensible to human beings. Nobody made a contract with us guaranteeing we would be able to understand everything clearly and in accordance with our preconceived notions. Humans and any similar humanoids in other parts of the universe apparently only occupy a small part of it. We do not appear important in the entire scheme of things. The universe creates without regard for everyone. This is probably what Niels Bohr had in mind when he retorted after Einstein repeated his well-known saying, "God does not play dice with the universe." Bohr replied, "Albert, stop telling God what to do." (Hazen and Trefil 69.) It would have been better for Einstein to state that the feature of probability in quantum mechanics was something that he did not accept rather than try to declare God's intentions.
In spite of the bewilderment exhibited by physicists about quantum theory, there seems to be unanimous agreement that it describes the particles that compose all objects in the universe. It is also consistent and integrated with the visible realm. While it is hard to understand how the quantum laws in the minute subatomic range manage to relate to and, in a sense, control the actions of the larger objects, the laws of the latter still operate much as formulated by scientists before 1900.
The physical continuum (as opposed to quantum) laws still produce the same predictable actions and results they did many millennia ago. Rivers still flow, boulders still fall, liquids still evaporate, winds still blow with a strong force, animals still get hungry, dynamite explodes, lightning kills, the world turns. Nothing in the larger universe is different. The various long-standing laws are no less effective now than they were before quantum mechanics. It is silly to even think of nature and its laws changing or ceasing to function simply because humans discover something. Although the quantum world and the atomic world seem very different, they interacted smoothly well before humans delved inside the atom. When you think about it, it should not be too surprising that things as tiny as photons and electrons should act differently from larger items.
Flapdoodle
Then there are all the wacky claims about what quantum theory implies. In The Quark and the Jaguar, Nobel Prize winner Gell-Mann lamented this unfortunate situation. He is well known for coining the term "quark." In a chapter entitled "Quantum Mechanics and Flapdoodle," Gell-Mann pointed out
While many questions about quantum mechanics are still not fully resolved, there is no point in introducing needless mystification where in fact no problem exists. Yet a great deal of recent writing about quantum mechanics has done just that.Because quantum mechanics predicts only probabilities, it has gained a reputation in some circles of permitting just about anything.(Gell-Mann 167)
Gell-Mann discussed the EPR Experiment and Bell's Theorem. He pointed out that related experiments did not show that photons could travel faster than the speed of light. They did demonstrate that quantum mechanics was correct. According to Gell-Mann, the experiments should have quieted disputes about quantum theory but instead:
The principal distortion disseminated in the news media and in various books is the implication, or even the explicit claim, that measuring the polarization, circular or plane, of one of the photons somehow affects the other photon. In fact, the measurement does not cause any physical effect to propagate from one photon to the other.(Id. 172)
He also took issue with claims that quantum theory favors paranormal phenomena.
Next, certain writers have claimed acceptability in quantum mechanics for alleged "paranormal" phenomena like precognition, in which results of chance processes are supposed to be known in advance to "psychic" individuals. Needless to say, such phenomena would be just as upsetting in quantum mechanics as in classical physics; if genuine, they would require a complete revamping of the laws of nature as we know them.(Id. 173. See also Victor Stenger, Physics and Psychics 1990.)
Chemistry: The Actions of Atoms
Particle physics has discovered the particles that seem to be the smallest items in the universe. Quarks and leptons make up atoms but have not been found existing alone. Electrons apparently travel individually in electric current, but they are not considered to be alone in that flow. The stream of electrons is created in connection with the atoms in which they are originally lodged.
Atoms are the smallest objects that can maintain a stable existence on their own. There are different kinds of atoms depending upon the number protons, neutrons, and electrons they contain. Each kind of atom makes up an element that is considered a pure substance that cannot be broken down into smaller substances by chemical means.(Frederick Bettelheim, William Brown, and Jerry March, Introduction to General, Organic, and Biochemistry, 6th ed. (Philadelphia, Pennsylvania: Harcourt College Publishers, 2001) 28.) They can be broken down by bombardment of their nuclei with smaller particles such as protons, but this is not considered a chemical reaction. Instead, it is a brute physical action. This technique using particle accelerators falls in the area of physics.
Chemistry is the study of the structure, properties, and reactions of atoms in some of their changes in form. There are now 114 known elements. Eighty-eight have been found in nature while the rest have been synthesized by physical scientists.(Id.) All matter found in the earth is constructed in some way from the 88 natural elements. Scientists are highly certain that all the matter in the entire universe is likewise composed of these elements.
The next step up from the elements in the staircase of physical existence is mixtures and compounds made from the elements. A mixture need not always contain the same proportion of elements. The dust found on the ground is a mixture of different proportions of different elements and compounds depending upon the location found on earth. Blood, butter, gasoline, and soap are mixtures.(Id. 30). The air all around is a mixture of several elements in relatively constant proportions. It has been claimed that there is slightly less oxygen in the air today than there was 100 years ago, so the mixture can vary.
Compounds are combinations of elements that are always found in the same fixed proportions by weight. Compounds aren't simply made by stirring different elements in a container as in the case of mixtures. Compounds either occur naturally or are produced by some process like heating.
Zinc is an element that is black, while sulphur is yellow in color. When simply mixed together, one can discern black and yellow particles in the resulting mixture. On the other hand when heated to a specific temperature, the compound zinc sulfide (ZnS) is produced which has no black or yellow color but is instead solely white. The characteristics or properties of zinc sulfide are different from either zinc or sulfur. A compound always has the same proportions of its different constituent elements. Zinc sulfide (ZnS) has one part zinc and one part sulfur, a ratio of one to one. Table salt or sodium chloride (NaCl) likewise has a ratio of 1:1 of sodium to chlorine. Water is a little different. Its formula is H2O. This means that it has two parts of hydrogen for each part of oxygen. An element with no subscript counts as only one part.
To keep track of what happens during chemical reactions, chemists long ago devised chemical equations. For instance in the making of a compound, the symbols for each of the elements or compounds are written on the left, followed by a horizontal arrow pointing to the right, followed by the substance(s) (compounds or elements) that are produced on the right. Here is an example that shows the burning of propane gas that leaves carbon dioxide and water as byproducts.
The large numbers in front of three of the formulas are called coefficients and help balance the equation. The balancing makes sure there is the same number of atoms on each side of the equation. This reflects what always happens in nature which is that, regardless of the chemical reaction, the total number of atoms in the materials (called reactants) present before the reaction takes place is always equal to the number of atoms in the products. This confirms the Law of the Conservation of Mass discovered by Antoine Lavoisier in the late 1700's that states that matter can neither be created nor destroyed. Every chemical reaction has its corresponding equation.
The Work of the Electrons
How is it that atoms of one element are able to adhere to the atoms of one or more other elements and form the new materials known as compounds? What happens when compounds are broken up into their constituent elements or smaller compounds? Are compounds put together by a glue?
The process is not a simple matter of glue being applied to atoms. It all has to do with the electrons of atoms. That is why chemistry has been called first and foremost the science of electrons and their interactions. (Hazen and Trefil 76.) The activity that binds and separates atoms takes place in the outer electron shell of the atom. The electrons in this shell are called valence electrons.
It is not a matter of different shells around an atom's nucleus in which different electrons travel around the nucleus. It is much more complicated. Scientists do refer to shells but electrons also exist in orbitals that are designated different numbers and letters. The lowest energy state--the ground state--is called the 1s orbital with the next higher energy levels consisting of orbitals 2s and 2sx, 2sy, and 2sz. There are a number of still higher energy level orbitals.
Chemists have devised elaborate systems of notation for keeping up with the electrons in the atom. One such scheme is that of Lewis structures. For each element, its atomic symbol is written down with dots placed around it--each dot representing the number of valence electrons (the ones in the outer shell).
The number of valence electrons in the atoms of different elements explains why elements in the same column in the periodic table of elements have similar properties. Dmitri Mendeleev published his first table of elements in 1869, and the periodic nature of the table was noticed immediately. No one could, however, explain why groups of elements had similarities.
With the discovery of electron configuration, chemists were finally able to discern how the periodicity manifests itself. Elements in the same column have the same configuration of electrons in the outer shell. Those similar elements also have differences that are explained in that they have a different number of protons and a different number of inner shells.
Electron configuration also explains how the atoms of different elements bind together. In general, atoms have a tendency to acquire a filled valance shell that in most cases is eight electrons. This is called the Octet Rule. (Bettelheim 56) To gain a full valence shell, some electrons give up electrons while others gain them. Atoms with a surplus or deficiency of electrons in the outer shell become ions. A positively charged ion is called a cation; a negatively charged one is an anion. Opposite charges attract, so sometimes these two types of ions (of different elements) unite by an ionic bond to make a compound.
At other times, atoms may share electrons in what is called a covalent bond. These are the main types of bonds. There are two others. One is the metallic bond that involves a large number of atoms of different metallic elements sharing outer electrons in a large system. Another bond is called the van der Waals bond. Metals give up outer-shell electrons more easily than other elements, which is why they are good conductors of electricity. This is another aspect of chemical bonding. At the opposite tendency from metals are the inert gases, which do not exchange electrons with other elements.
There are materials made from elements all around us. There is nothing that we see or touch that does not come from the elements, even if it is a mixture or a compound. Of course, even much of what we don't see is also elements or is derived from them. The clearest example of this is the air we breathe--made up of nitrogen, oxygen, hydrogen, and small amounts of inert gases. The very ground we walk on, the mountains we climb, the seawater we swim in is made of element-based material. Most of the material on and inside the earth is made of mixtures rather than pure elements or compounds.
When standing on the earth, one stands on rock--either solid rock or dirt that comes from the deterioration of rock. Geologists call this deterioration, weathering. Geology is that part of earth science that studies a variety of the aspects of the earth, for the most part concentrating on its crust and interior. Oceanography keeps up with the oceans and other large bodies of water. A large subtopic of geology is petrology, the study of rocks, since that is the composition of so much of the earth. Since in turn rocks consist of different minerals, mineralogy contains a wide body of knowledge. Chemistry is involved in all aspects of earth science including the classification and analysis of all the things that comprise the earth and its surroundings. For this reason, there is an area called geochemistry.
Growth of the Earth
The rocks that are seen today were not present at the beginning of the earth although most of us probably think they were. A continuous process of formation and deformation has been taking place ever since. Geology has catalogued in detail how the earth has changed in drastic ways from the time that it started. Most people probably assume that the continents and oceans have always looked much like they do today, with some small change due to erosion and volcanic activity in a few special locations where volcanoes are found today. There is also the frequent assumption that the earth will always look much like it does today. Some might know that there has been drastic geological change but also think that all that is something of the past and that there will be little change from here on.
One basis for those assumptions is probably another assumption--that the earth is only a few million years old. For a long time, it was believed that the earth was only a few thousand years old. In the mid-1600's, an Anglican archbishop in Ireland, James Ussher, was a respected Bible scholar. He calculated, on the basis of the narrative events found in the Tanakh (Old Testament), that the earth was created in 4,004 B.C.E.(Edward Tarbuck and Frederick Lutgens, Earth Science, 9th ed. (Upper Saddle River, New Jersey: Prentice Hall, 2000) 273.) That is a little more than 6,000 years ago. Religious leaders and even scientific scholars of the time accepted this.(Id.) The geologists and cosmologists who have been studying the earth's age have today come up with a much different number--about 4.567 billion years.
One way that the age has been calculated is through radiometric dating. This method makes use of the instability of the nuclei of the isotopes of some elements like uranium, potassium, and carbon. An isotope is a variant form of the element. It has a different number of neutrons from that found in the common form of the element. The instability of a nucleus is due to the weakness of the force binding the protons and neutrons in the nucleus of the particular isotope. This weakness allows some of the nuclear particles to be emitted from the nucleus on a regular basis. This process is what we know as radioactive decay or radioactivity. Measurements can be made of the byproducts of this radioactive decay. This has been found to give a very accurate assessment of the age of rocks and other materials. The rate of decay is highly regular and predictable and so the age measurement is very reliable.
4.6 billion years for the age of the earth makes it much more plausible that many of the processes that took place did so at a gradual pace. When it was believed that the earth was only a few thousand years old, an accompanying belief was that mountains and canyons had to be have been formed as a result of large-scale geological catastrophes. This idea is known as catastrophism.(Id.) With the much greater age estimated today, there was more time for the gradual formation of mountains and the various landscapes as well as a slow creation, development, and extinction of living things.
In the very beginning of this world, if you had been able to stand, you would not have found any rocks or ground on which to do it. You would have had to stand on a thin mass (more like a cloud) of the first elements that were to congeal. These were mostly the gases hydrogen and helium with a small percentage of heavier elements.(Id. 297) As the temperature cooled, iron and nickel were probably the first to solidify, followed by silicon, carbon, and other elements that compose sand and rock. You would have only been standing on tiny particles, perhaps just atoms of elements and they would have been very hot.
This thin cloud of simple dust would have begun as part of a much larger cloud that began spinning about 5 billion years ago. The spin accelerated gradually and heated up, especially in the center, and flattened into a disk. Over a period of a half-billion years, this disk cloud coalesced into our solar system. The center became hotter and hotter and eventually became the sun. At the same time, the outer part of the disk became significantly cooler.
After several million years of condensation of the primordial material, protoplanets began to slowly form from the accumulated dust in the air. As this dust settled, it began to allow sunlight to reach the protoplanets and warm them. The inner planets, including the earth, became too hot to retain the gases and water vapor that had formed. These lighter materials were carried away by particles coming from the sun. The planets farther away from the sun were cooler and thus able to keep the gases in and around them. It is thought that this is the reason that to this day those planets, since they contain much more gaseous material, are much larger but have less density.
Heating of the earth caused the melting of the denser metallic elements like iron and nickel, which facilitated their sinking toward the center. At the same time, the lighter elements floated to the top and formed the rocky outer layers. This is still occurring to some extent today. The process explains why the earth is not made of the same material throughout but rather consists of shells of varying material.
Composition of the Earth
The earth is composed of the core, the mantle, and a very thin crust. The core is divided into the inner core and the outer core. The distance from the center of the earth to the end of the inner core is 1,216 kilometers (754 miles). The inner core is a solid metal sphere that, along with the constant rotation of the earth, helps to account for the magnetic field around the earth. The outer core appears to be a mobile liquid that is 2,270 kilometers (1,407 miles) thick. The mantle is made of rock, is 2,885 kilometers (1,789 miles) thick, and consists of a lower and an upper mantle. The lower mantle is about four times thicker than the upper mantle. On top of all this lies either the oceanic crust or the continental crust that on average is 35 kilometers thick. It is understandably thicker in mountainous regions. The oceanic crust measures only 5 kilometers in thickness.(Id. 174-175)
Geologists have mostly been able to determine all this information through the measurement of seismic waves produced by earthquakes. These waves travel through the earth and can be detected by seismographs at different parts of the earth's surface, including all the way to the other side of the globe. Differences in the speed of the waves in arriving at different points indicate that there are differences in thickness in the interior. Seismographs have come in very handy for this purpose, in addition to their better known function of predicting earthquakes. It has not been possible to learn much through direct penetration into the earth. The deepest well goes in only 8 miles, which is only .2% of the distance to the center.
The Ingredients of the Ground
The earth's crust is made of rock, including dirt and sand that consist mostly of weathered or worn-down rock. Only eight elements form most of the rocks on the crust. By weight, they compose more than 98% of the continental crust.(Id. 24) Oxygen is the most abundant element in the earth's crust, about 46.6% by weight, followed by silicon at 27.7%. After that, aluminum weighs in at 8.1% followed by iron at 5% and calcium at 3.6%, with only a few more taking up the rest.(Id. 26)
Elements are not usually found alone in the crust but instead combine to form a variety of compounds called minerals. Over 50% of the entire crust is composed of a group called the feldspars, which in turn belong to a larger group known as the silicates. They all contain silicon and oxygen combined in a tetrahedron structure of four large oxygen atoms surrounding a smaller silicon atom.(Id.)
All silicates have other elements associated with them in one combination or another. The orthoclase feldspars, for instance, have the chemical formula KAlS3O8. They are potassium (K) and aluminum (Al) in addition to silicon (S) and oxygen (O). Quartz is the only mineral that is constructed solely of silicon and oxygen (SiO2).
Nonsilicate minerals make up only one-fourth of the continental crust. The carbonates are the largest group of these. Halite (table salt) and gypsum are well-known minerals. Gold, silver, copper, and carbon (in the form of diamond and graphite) are found alone and considered nonsilicate minerals.
The Rock Cycle
These minerals were gradually shaped into the rocks we know today over the long lifetime of the planet. Where rocks are found today may have been the site of a sand dune, a river, a volcano, or an ocean among other things many eons ago. The surface of the earth has gone through many transformations to bring us what we see today.
After many years of close study, geologists have discerned a rough pattern for how rock has been created, and it is sufficiently regular and consistent to be named the rock cycle. This cycle can be said to begin with the formation of magma, which everyone knows about because it comes out of volcanoes. For this molten material to flow out of the earth clearly implies that the earth must be very hot inside. Lava is similar to magma except that it carries little gas in it.(Id. 36) Not all magma rises to the surface. Some of it fails to travel that far and simply solidifies among the rocks below. In the early years of the planet when it was much hotter, there was probably much more of this kind of inner earth activity. Because these rocks are created by fire, they are called igneous rocks.
Very slowly these rocks experience weathering. The dust they give off is then eroded by water and wind. This dust is eventually deposited in what is called sediment. Most of it goes into the seas and oceans, but it can also form sand dunes. Over more time, layers of sediment are deposited on earlier layers. The weight of the upper layers causes compaction of the lower sedimentary layers. After that, the sediment is further solidified when water carries minerals into any spaces still left. This process is called cementation, and along with compaction, produces what is called sedimentary rock.
This type of rock comprises the majority of the rock on the surface of the earth but very little of the rock that exists further down. Sediment can form only on the surface. Some forms of sedimentary rock have proven very important. For instance, petroleum and natural gas are found in the pores of sedimentary rock. Coal has had widespread use in generating electricity.(Id. 44) Quartz is used to make watches and clocks that keep accurate time. Luckily it is abundant.
The next step in the cycle involves the transformation of igneous and sedimentary rock into metamorphic rock. This occurs through the intense heat and pressure that build underneath the surface. Pressure can be exerted from above in the same way that it works to make sedimentary rock. The upper layers exert gravitational pressure on those beneath, with even greater pressure on those farther down. Those lower layers are at the same time subjected to pressure from underneath because of the activity that takes place below. There can also be pressure from a horizontal direction.
The rocks at the lower levels are subject to the greater heat at those levels and are more pliable than the hard rocks with which we are familiar. They are bent, curled, and otherwise reshaped into a much different shape and texture than they had before. Rock that comes into contact with magma is also metamorphised by the high temperatures of the magma.
As mentioned before, igneous rocks can be changed into metamorphic rock, thus skipping the step in the rock cycle that involves the making of sedimentary rock. Another way that the cycle can be broken occurs when sedimentary rock breaks down before there is the chance for it to change into metamorphic rock. Instead, the sedimentary rock turns back into loose sediment in the same way igneous rock does, by weathering and by erosion.
Chemical processes can also produce metamorphic rock. Water is found in the pores of rocks and helps to bring in ions that change the crystal form or the mineral composition of the rock. Finally, metamorphic rock located in the right place can be melted into magma and complete the cycle.
The Hydrologic Cycle
A cycle of the earth that is very important and is easily recognized by people is the hydrologic cycle. Mention was made of this in the Tanakh in Ecclesiastes 1:7:
Every river flows into the sea, but the sea is not yet full. The water returns to where the rivers began, and starts all over again.(Good News Bible (New York: American Bible Society, 1978).)
The hydrologic cycle involves the precious and unique compound, water, which is in abundance on earth, unlike any other planet in our solar system. 97% of the water in our hydrosphere--the total body of active water in and around the planet--is in the oceans. Of the remaining portion, the greatest part is in glaciers.(Id. 90) The hydrologic cycle is simple. Precipitation in the form of rain, snow, sleet, hail, or dew fall on the land and the oceans. This happens quickly in comparison with the slow evaporation that follows. Since the oceans cover 71% of the surface, most of this action takes place over them. The water vapor that rises to the sky forms clouds that when full enough unload the water back onto the earth. Some of the water that falls on the continents runs off the land into the oceans and other bodies of water. A small amount of water on land seeps down into the earth but rises again and comes into lakes from underneath. The precipitation that has fallen on mountain peaks has shaped those mountains by running down from them.
The water cycle and the rock cycle work in tandem with each other for part of their duration. This occurs after precipitation has fallen and the resulting water flows to bodies of water to lay down sediment. In the rock cycle, this is the step that eventually produces sedimentary rock. The rock and hydrologic cycles are two subsystems that help give the earth the characteristics that it exhibits. Subsystems often interact with each other. Together they comprise that greater complete system which is the earth.
The solid earth is not simply a static stone but is always active continually reconstructing itself. The hydrologic cycle is a process of the hydrosphere that involves all the water of the earth including that in clouds and under the ground. The atmosphere is the system that involves the air that provides a protective shield against overheating by the sun, as well as much of the lethal radiation that it sends our way. The atmosphere also provides the carbon dioxide that is essential to plants and the oxygen essential to animals. Finally, the biosphere includes all plants, insects, and animals. Living things depend on the other systems for their survival and well-being. They also contribute to the earth.
For example, the remains of plant and animal matter are essential in the soil in order to grow crops. Lay people think of soil as simply dust or dirt, the loose bits of rock material that are found on the ground.(Dirt is supposed to have a connotation of a material that is unclean. The word is derived from an old Norse word for excrement.(Webster's New World Dictionary, College Edition (Cleveland, Ohio: The World Publishing Co., 1960).)
Earth scientists have a special name for dirt, regolith. They distinguish soil from regolith by holding that soil additionally contains organic matter, the remains of plant and animal matter. Soil also has to contain a small amount of water and air, and all these four ingredients are necessary for growing plants. Regolith alone is not enough. Humus is the name for the decayed remains of former living things, mostly plants. There are hundreds of soil types around the world. Three generic types are pedalfers, pedocals, and laterites. Coal is a sedimentary rock that contained humus when it first began to take shape. Without this component, it might not be as useful as it is today.
Hades
The mythology of different cultures has held that after people finish their normal lives they go to a dark place underground where there is gloom and lethargy. The earliest account of such a place is found in the earliest known literary work, the Sumerian Epic of Gilgamesh. Sheol was the ancient Hebrew name for it. Belief in it was widely accepted in the Middle East. It was mostly mentioned in poetry.(The Wordsworth Dictionary of Beliefs and Religions, Rosemary Goring, ed. (Hertfordshire, England: Wordsworth Editions Ltd., 1995) 478.) The Greeks also believed in an underworld with Hades as its king. Later, the place itself began to be called Hades.
Claims are made today by a few people that there are colonies of humans living inside the earth. Supposedly, the underground beings residing there are responsible for at least some of the flying saucers or unidentified flying objects (UFO's) that some people have at times claimed to spot in the sky, especially at night.(The AM radio show, Coast to Coast, had guests who have made these and other unusual claims.)
Geologists have probed underground to a great extent and have learned much about earthquakes and volcanoes but have not reported finding either an underworld or civilizations of living conscious beings. They have found a hot earth below with magma that rises to the surface at different locations but nothing more dynamic than that. The world below appears very much to be mundane, inorganic, and physical.
Early Ideas on Weather
In the world's ancient religions, there were numerous gods who were in charge of different features of nature. They could whip up the seas or the winds on their command whenever they became displeased with humans, even individual ones. If other innocent humans or animals had to suffer because of the deity's displeasure with a solitary individual, then so be it.
A sun god was worshipped by a number of primitive civilizations. The Egyptian sun god was Ra and was believed to control all the heavenly bodies and to move across the sky in a boat each day and return to the starting point through the underworld at night. Ra was also king of the gods. The Aztec sun god was Tonatiuh, who can be seen in the center of the Aztec calendar.(William J. Burroughs, Bob Crowder, Ted Robertson, Eleanor Vallier-Talbot, and Richard Whitaker, A Guide to Weather (San Francisco, California: Fog City Press, 2002) 62.) The Babylonians, whose civilization in the Middle East lasted from about 2,000 B.C.E. to 539 B.C.E., had as their god of the sun, Tammuz, also known as Dumu-zi and Adonai. (Anne Baumgartner, Ye Gods (Secaucus, New Jersey: Lyle Stuart, Inc. 1984) 170.) The god of the sun for the Slavs was Svarog while Svatog was god of the atmosphere.(Id. 166) In India, Vishnu was the god of the sun but Agni was also the god of the sun who in addition controlled lightning and fire.
In Germanic religious belief, Thor was the god of thunder. His name was the old German word for thunder. In ancient Greek religion, Zeus was the king of the gods but was specifically in charge of the rain and thunder. It was thought that he specifically hurled the lightning bolts that came out of rain clouds. Poseidon, brother of Zeus, was the god of the sea. Zeus put Aeolus in charge of the winds. It is not clear whether he was a mortal. ("Aeolus," Encyclopedia Britannica: Micropedia, 1987.) In Native American lore, a giant thunderbird was in charge of thunder, lightning, and rain.
Meteorologia
Early Greek philosophers were involved in understanding meteorological phenomena at the same time they were trying to decide what everything was made of. They clearly eschewed explanations based on belief in godlike personal forces but instead turned to close observation of nature. Thales, mentioned earlier as the first known philosopher, was the first person known to accurately predict a solar eclipse. He did this in 585 B.C.E., not by consulting an oracle or divining what the gods would do, but by consulting observational records of Babylonian astronomers that he had collected.(Burroughs 64)
Aristotle made some accurate observations about weather phenomena in his treatise, "Meteorologia." The title gave rise to the term for the study of the weather. To this day, metereologists have continued to base their organized accounts, not on faceless sources passing down myths from the amorphous past, but on careful, repeated observations by thousands of people and deductions from that collected information.
Air and Water
The weather phenomena that we frequently observe in the atmosphere are based on the movement of air and water. The composition of both is very simple. Air is a mixture of elements, mostly nitrogen (78%) and oxygen (21%). This totals 99%. The other 1% is mostly argon at .9%. The other .1% is made of carbon dioxide (.003%) and traces of neon, helium, krypton, hydrogen, and ozone.(Id. 24)
These two materials, air and water, simple as they may be from a chemical standpoint can undergo significant transformation in the atmosphere and cause havoc on the inhabitants below. Just to start, air is responsible for those summer days when it becomes sweltering. This involves a simple matter of air pressure. Whenever air sinks from the higher levels of the atmosphere toward the ground, it creates high air pressure right above the ground. This high pressure brings what is called "fair weather," meaning the skies are clear of clouds.
Air Pressure
In the winter, this can be a welcome situation because it allows the sun to shine through and provides some warmth. In the summer, the sun can overdo the job of warming the earth, especially in desert areas. If the sun shines through with high pressure for a number of consecutive days, it can bring a heat wave. The greater air pressure means that air molecules are moving faster and are more crowded around you. This is what makes you feel hotter. Reference is made to air molecules rather than atoms because in the lower atmosphere oxygen can be found in the form of molecules each composed of two atoms.
The condition of low pressure occurs whenever air rises from the ground. This facilitates the formation of clouds, which are simply dense condensations of water, not instruments of the gods. Thus the first basic component of weather phenomena, the movement of air, is instrumental in bringing about the second component--the movement of water. Air pressure affects the movement of air up and down. Air pressure also affects the horizontal movement of air that we can definitely feel. It is what we call wind or breeze.
Uneven heating of the earth by the sun causes differences in air pressure in different areas. Regions with the same pressure are called pressure cells or systems or centers. There are many of those at any one time around the globe. Whenever a high-pressure cell is found next to a low-pressure one, there is a natural move toward equalization of the pressure by movement of molecules from the high-pressure area to the low-pressure one. The difference in pressure between the two cells is called the pressure gradient, and the greater the difference, the higher the speed of the winds that always travel from the high pressure area to the low pressure area. Meteorologists use maps with isobars, which are lines indicating the different areas of pressure. They use a system of arrows to show the differences in wind speed.
The uneven heat that produces the differences in pressure comes from the sun, the prime mover of air. The heat from the sun's rays also causes the movement of water upward to form clouds through the evaporation of water, mostly from the oceans. Thus the sun is ultimately the prime cause of wind and clouds.
The Wind
One reason there is uneven heating of the earth's surface is that the tropical regions retain more heat from the sun than they radiate back, while the polar regions lose more than they receive. A better balance is then sought, so a global heat transfer system moves warm air from the equator toward the poles while pushing cold polar air toward the equator. Ocean currents contribute a little to this system.
There are numerous wind cells around the globe, and a general pattern has been discovered. At the equator, air rises and flows toward the poles. At latitudes of 30o both north and south of the equator, the air sinks to the ground. Most of the earth's deserts are located in these 30o latitudes due to the high pressure created by the sinking air.(Id. 30) The air cells force some air out of the 30o latitude, which then travels back toward the equator in what are called the trade winds. These winds do not flow directly north or south back to the equator. In the northern hemisphere, they come out of the northeast and in the southern hemisphere, out of the southeast. There are other winds in the two hemispheres that have the same name and are mirror images of each other in their direction of flow. In addition to the trade winds, there are the westerlies and the polar easterlies.
At 30o latitude, both north and south wind cells exist which circulate air between 30o and 60o where it meets with air from the polar cells. The cells in between 30o and 60o are called Ferrel cells. The air in the polar cells travels back to the poles from the 60o latitude lines.(Id. 31) The jet streams travel from the west (the same direction as the earth's rotation) along the 30o latitude north and south. Jet streams were discovered by World War II pilots when they went high in the air. They are located about 35,000 feet (10,500 meters) high and can be strong, sometimes getting to a speed of 180 miles per hour (300 kph).(Id.)
The foregoing description of winds is an idealized one. Besides the effect of different pressures in producing winds, the earth's rotation also affects wind direction. Due to the rotation, the points on the earth's surface are constantly changing position. Wind travels in a straight path above the surface, and when it travels several miles, it arrives at a point that is different from the point it would hit if the earth were not rotating. This situation makes it appear that the wind direction has shifted to someone taking a measurement of direction. This change is known as the Coriolis effect after the French scientist who first described it.(Tarbuck 444)
Within a few kilometers above the earth's surface, friction with the surface affects wind direction by slowing air movement. This braking effect does not directly affect direction, which makes sense once you think about it. The influence is an indirect one because higher wind speed increases the deflection produced by the Coriolis effect.(For more detail refer to Tarbuck 445-446.)
In addition to the large-scale wind circulation patterns (which are only generalizations), there are local winds. Pressure differences also generate those winds. One example of a local wind is a sea breeze. This happens because in the early part of the day air over coastal land warms faster than adjacent air over water. By the late afternoon, the warmer land air rises allowing cool air over the water to blow onto the land. This keeps the temperatures for coastal residents lower than they would be otherwise. At night, the opposite process takes place creating a land breeze flowing to the sea.
Cyclones
Most people think of a cyclone as simply a strong spiraling wind accompanied by heavy rain. Meteorologists define a cyclone in more detail. A cyclone or low is a low-pressure system with pressure higher on its boundary than in its center. A cyclone can cover an area of thousands of miles. Since wind travels from high pressure to low pressure, the wind in a cyclone swirls from the outside to the center. Furthermore, the Coriolis effect insures that in the northern hemisphere the wind spirals in a counterclockwise direction and in the southern hemisphere in a clockwise direction. Cyclones move west to east across the United States. They are common and need not be the kind of violent storm that produces headlines, but they do cause common storms. Weather forecasters in the media talk about these as lows rather than cyclones for good reason; they don't want to alarm listeners.
Weather professionals also know about anticyclones (highs) of which most of the public never hears. They are the opposite of cyclones because their centers contain higher pressure than their outside so the wind always moves outward from the center. The Coriolis effect makes the wind spiral clockwise in the northern hemisphere and counterclockwise in the southern one. Anticyclones feature air descending down their columns that warms as it falls creating high pressure and preventing cloud formation. They are associated with clear skies, while lows or cyclones bring precipitation.
Air travels rapidly in the form of wind, but it also moves gradually in immense air masses. These masses can be 1,000 miles (1,600 kilometers) across and several miles thick.(Id. 464) An air mass is characterized by a similar level of temperature and moisture throughout at the same altitude and latitude. Air masses are classified by region of their source. There are two major types: polar and tropical. These are further subdivided into those that originate in the oceans (maritime) and those that start over land (continental).
Air masses at times collide with one another. The boundaries of these clashes are called fronts, so named by Norwegian meteorologists during World War II because they imagined them like advancing armies.(Id. 467) When warm air moves and displaces cooler air, it is called a warm front, and when cold (cool in the summer) air occupies a region formerly held by warm air, it is considered a cold (cool) front.
Both warm and cold fronts produce clouds but warm fronts advance slowly and thus produce moderate precipitation over a large area for several hours. In both types of fronts, the warm air lifts over the cold air, but this happens more rapidly in a cold front, which also advances faster. Both of these two factors contribute to heavier precipitation with strong wind gusts from a cold front, but the storms also pass quickly. Sometimes neither the warm air mass nor the cold air mass is able to invade the other but instead run parallel to each other in a parallel front.
Ocean Currents
Water heats and cools more slowly than land. Ocean currents can travel long distances and carry warm or cold water to far away places. The temperature of ocean or sea water affects climate. Meteorologists have recently appreciated how ocean currents originating in one area of the globe can affect remote locations.
It had been noticed some time ago that the temperature of ocean currents affects coasts. For instance, the California current runs from the Pacific Ocean toward California where it splits and then runs partly along the coast to the north and partly to the south. In the summer, it has the effect of producing winds that cool the coast while locations just a few miles inland like Palm Springs experience temperatures in the 100's (Fahrenheit). England lies at the same latitude as the northern parts of Germany, Russia, and Canada, yet enjoys much milder winters. This is attributable to the Gulf Stream which carries warm water from the direction of the United States and passes north of England.(Burroughs 38)
There is one particular ocean current effect that started receiving attention after 1997. It always occurs around Christmas time and so was given the name El Nino (Christ child). Every year the waters off the coast of Ecuador and Peru warm up for several weeks around that time.
Normally, there is a strong equatorial current running from the coast of Ecuador westward to the island of New Guinea, north of Australia. This westward current helps bring up cold water from deeper in the ocean near Ecuador and Peru. The cold water brings up nutrients that feed fish, especially anchovies.(Tarbuck 453) Every 3 to 7 years at Christmas time, the coastal waters become especially warm. This is due to the reversal in the normal flow of wind and warm water in the equatorial Pacific Ocean. Trade winds shift direction and go east instead of west and much warm water flows toward Ecuador.
The warm water arriving at the coast blocks the cold water bringing nutrients from below and starves anchovies, harming the economies of nearby fishing communities. There are also heavy rains and floods in normally arid regions of Ecuador and Peru. In 1997 and 1998, a very strong El Nino brought 350 centimeters of precipitation to areas that normally receive only about 12 centimeters. At the other end of the countercurrent, there were also dire effects. In Indonesia, Australia, and the Philippines, there were severe droughts that caused huge crop losses and consequent economic effects.
The most interesting part was the discovery that the warmer El Nino currents had surprising effects thousands of miles away. Fierce storms struck the California coast that caused widespread flooding and landslides. Even further away, heavy rain with flooding drenched states in the U.S. located north of the Gulf of Mexico. On the beneficial side, it seems that one of the effects of El Nino was to chop off the northern portions of storms in the Atlantic Ocean, making it one of the quietest hurricane seasons in years.
Fierce Storms
There are three severe types of storms that evoke much fear and attention due to their rapid and dramatic appearance as well as the widespread death and destruction they can bring. The first of these is the thunderstorm with which everyone if familiar. They occur more frequently than the other two, the tornado and the hurricane. A thunderstorm occurs by itself but is also a component of tornadoes and hurricanes.
At any one moment, there are about 2,000 thunderstorms going on around the world. In a single day, there are about 45,000 thunderstorms and in a year, there are an average of 16 million. Lightning strikes different parts of the earth about 100 times per second.(Id. 476) Lightning is the reason thunderstorms are also known as electrical storms. "Lightning storm" is probably the better name since thunder is really a sound effect caused by a lightning bolt. The temperature of a bolt is 40,000oF (22,000o C). The air around a lightning bolt expands very rapidly due to this intense heat and then collapses again. This collapse of the air makes the sound we hear as a thunder clap. We see the lightning before we hear the thunder because light travels many times faster than sound.(Burroughs 51) If the lightning hits next to us, we'll experience them at once.
Tornadoes and hurricanes are much more intense and therefore better publicized than thunderstorms. They can cause great havoc in a few hours. Many people never experience even one tornado or hurricane in their entire lifetimes but live through hundreds of thunderstorms. Accordingly, lightning storms and plain old rainstorms cause more deaths than tornadoes and hurricanes. According to the National Weather Service, the average number of deaths caused by four different types of weather events in a 30-year period was as follows:
Floods ......................... 139
Lightning ..................... 84
Tornadoes .................... 69
Hurricanes ................... 27
Lightning
Lightning only recently started to receive the attention it needs as a potential killer. Death and injury by lightning occur with only one or two victims at a time and so it manages to escape notice in that regard.
The clouds that bring lightning storms are created like any other cloud--by the lifting of water vapor upward by warm air. As with all cloud creation, a condition of low pressure is necessary. The difference between a regular cloud and a thunderhead or cumulonimbus cloud is that with the latter the moist air just keeps going and going up. The updrafts of air exceed speeds of 60 miles (100 kilometers) per hour to build clouds reaching more than 7 miles (12 kilometers) high. After that point, the water in the cloud becomes too much for the updrafts to support and precipitation begins to fall with downdrafts. This most active part of the storm brings strong winds, lightning, heavy rain, and sometimes hail. Each cumulonimbus cell only lasts about an hour, but in a moving storm new cells are created to continue the action of the storm.(Tarbuck 477-478)
Lightning is simply a massive electrical current created by opposing electrical charges that build up within cumulonimbus clouds. The ground can also be positively charged. It is still not known why electric charges build up in clouds, but it looks like the positive charge that appears at the top of lightning clouds is associated with ice crystals that form there, while warmer water droplets in the bottom part of the cloud become negatively charged. After the charges become very high, a discharge occurs between opposites.(Burroughs 50)
Most charges occur in the clouds either within the same cloud between top and bottom or from cloud to cloud between opposite charges of the different clouds. Cloud to air lightning can occur if the nearby air has a sufficient charge. Only one in four lightning bolts hits the ground. A bolt can go from the bottom of the cloud to something on the ground with a positive charge, usually a taller object like a tree or building. Occasionally, the positively charged top of the cloud will discharge all the way to the ground. In order to travel this farther distance, the bolt has to be much more powerful.(Id. 240) You definitely do not want to even get close to a lightning strike.
Tornadoes are the product of a few especially severe lightning storms. Luckily, less than 1% of all lightning storms produce tornadoes. (Tarbuck 479) Tornadoes can also be thought of as small, short-lived cyclones that develop out of lightning storms. A tornado is a rotating column of air that extends out of a cumulonimbus cloud. It is often also called a funnel cloud or vortex. It can reach a speed of 300 miles (480 kilometers) per hour.(Id. 478) Tornadoes can lift trees, cars, and people into the air and upend aircraft. Any single tornado does not last long, but they come in groups. It is not clear how the funnel builds up, but meteorologists calculate that strong updrafts in the lightning storm interact with winds situated higher up in the troposphere.
Hurricanes
Hurricanes are the strongest storms on earth. Like tornadoes, they are small cyclones that form in tropical ocean areas. They do not cover nearly as wide an area as the large cyclones (lows) discussed earlier. In the Indian Ocean, hurricanes are known as cyclones. In the western Pacific they are called typhoons.
The wind of a hurricane, which has been known to reach 185 miles (300 kilometers) per hour, can cause great destruction.(Id. 486) A storm surge is a dome of water about 40 miles (65 kilometers) wide that swoops across the coast at the strongest part of the storm. The surge is 6 to 10 feet (2 to 3 meters) above the normal height of the tide.(Id. 486) On a coastal area, the storm surge is responsible for 90% of all hurricane-related deaths. In 1970, a cyclone landed on a vulnerable coastal area of Bangladesh off the Indian Ocean and killed 200,000. Another cyclone almost as destructive struck again in 1991.
Hurricanes do not naturally give a warning of their approach. People can experience clear skies and little wind just a day before. Due to this quiet approach, the city of Galveston, Texas, was struck suddenly on September 8, 1900, by a hurricane even as people were merrily enjoying a day at the beach. No one expected the storm that hit the island and killed 6,000 people. 2,000 more were killed in nearby locations.(Id. 485)
With the aid of technology today, hurricanes can be anticipated several days in advance. Hurricanes that struck New Orleans and Houston in September, 2005, were anticipated well enough in advance to give residents who were able to do so a chance to drive to other locations. Satellites, radar, computers, and other physical equipment have been able to do what in the past priests, shamans, and soothsayers only wished they could do. This technology, like the dynamic weather systems themselves, has operated at all times on principles of physics. There has been no evidence that Aeolus or any other weather god has directed the movements of the weather.
The storms and other phenomena are based on simple physical components:
1. Energy, by way of heat, produced by the sun.
2. Water
3. Air being moved around in different ways by the energy from the sun.
4. Gravity to move the water from the clouds to the ground.
5. Lightning, which is peripheral to the downpours with which it is associated, is simply the movement of electrically charged ions to and from clouds or within them.
Chaos Theory
Chaos theory is a new area that mathematicians and scientists began to study in the 1960's. Chaos takes on a special meaning here. It does not mean total lack of order but rather involves the complexity (another name for it) and lack of predictability of certain processes in nature. Perhaps a better name would be "unpredictability theory" or "incomplete predictability theory." It is not that nothing can be predicted, but that after a certain point predictability cannot be exact.
Weather prediction is a fruitful area for investigation by chaos theory. For a long time, it has been clear that it is very difficult to predict weather patterns more than a few days in advance. In the early 1960's, meteorologist Edward Lorenz at the Massachusetts Institute of Technology studied the unpredictability of weather patterns and inspired later work in chaos theory.(Tim Palmer, "A Weather Eye on Unpredictability," Exploring Chaos: A Guide to the New Science of Disorder, Nina Hall, ed. (New York, New York: W.W. Norton & Company, 1993) 69 at 72.)
The atmosphere is air and acts like a turbulent fluid. Turbulence and disorder in fluids was observed long ago. Take, for instance, the flow of water from a tap. When it is only opened a little, there is a smooth flow in what looks like an inverted cone with regular walls. This simple flow is difficult enough to study even with the use of today's super computers. Incidentally, the calculations that can be carried out by supercomputers have been very beneficial in the study of chaos. Open the tap more, and you see the flow become turbulent and disordered, more like the flow found in nature in brooks, waterfalls, and the atmosphere. It becomes impossible to calculate the flow from the Navier-Stokes equations of fluid dynamics.(Tom Mullin, "Turbulent Times for Fluids," id. 60 at 61.)
Lorenz devised a mathematical model in three dimensions of all possible weather states. This model became known as the Lorenz attractor, or strange attractor. It was called strange because it had a fractional dimension of 2.06. Drawings of it are often shown as graphic presentations of equations in chaos theory. Fractals are another often seen example.
Needless to say chaos theory has helped confirm the idea that it will be very difficult to ever produce precise, long-term weather forecasts. There are simply too many variables. Figuring out all the initial conditions is also very difficult. The slightest variation in the initial conditions of any system, whether it be fluid, weather, or otherwise can have a strong effect on later conditions. In weather, a well-known example that has been used has been that of a butterfly flapping its wings in China causing a hurricane in the United States. Chaos theory has impinged on other areas e.g., population dynamics, mathematics, stock trading, engineering, and planetary orbits.
All of this is not to say that there are not some very accurate predictions made about weather, especially compared to before 1940. Weather forecasts keep getting better all the time. Yet science may have limitations in how far it can go in obtaining knowledge. Some people have pointed this out and apparently hoped for it. They seem to think that this signals that society should turn away from science and place its faith in religion or ancient rituals. Chaos theory implies nothing of the sort. Performing rain dances to influence the weather or consulting tea leaves to divine the future were proven dismal failures ages ago and that has not changed, even if science is shown to have limits.
While matter is now abundant throughout different parts of the universe, was it always there and in the same form? Has everything in the universe always been as we see it today through our telescopes? In other words, do we live in a static universe? If it had a beginning, how did it happen? Creation stories such as those found in religious myths usually have creatures make their appearance in full and final form. Neither they nor the universe itself go through any long period of development. Do the investigations of astronomers and physicists into the origin and development of the universe run into a blank wall after they go back to a particular point in time, or can they get a good idea of what might have happened in the beginning? The study of the origin and development of the universe is known as cosmology.
Implications
The importance of these considerations is that they can perhaps give us better insight into the nature of physical reality. If energy and matter have filled the universe for some time but before that cosmologists cannot find that they existed, that could mean something. If perhaps sound evidence could be found that the universe had operated before matter appeared or that spirit had created energy and matter, it would be a significant finding. It is not clear what would constitute solid evidence for spirit and its actions, but that is one possible claim for how matter could have originated. Even if it could be found that energy and matter were created at a certain point in time but that the universe had been operating mysteriously for a long time before without energy or matter, it could give reason to pause, considering that the two are of great ultimate importance. Also, looking at the origins of the physical universe could illuminate questions about the understanding of matter that we face today.
With this in mind, review some history of what has been thought are the features of the universe. After that, there will be a closer review of what recent cosmologists have calculated has happened in the early age of the universe, especially during the very eventful first five minutes.
Historical Highlights in Cosmology
For most of history, there was firm belief in a static universe. While many entertained the idea of a beginning of the universe, there were not many who believed it grew from a small seed and expanded gradually into what appeared later. It was assumed that the universe was created in full bloom with features that remained the same until the present.
The study of astronomy in ancient periods was connected with religion as priests and sages tried to find a way to divine future events from the position of the stars. The cult of Pythagoras taught that the movement of the heavenly bodies was directed harmoniously by natural laws.
In his book On the Heavens, Aristotle presented arguments for the earth being spherical rather than a flat plate. First, there was the observation that as ships coming toward land appeared on the horizon one would first see the sails and later, after the ship got closer, the hull of the ship. Eclipses of the moon also furnished evidence of the earth being a sphere. The shadow the earth cast on the moon was always round. If the earth had been a plate, one would expect that the shadow would sometimes look like an ellipse. The shadow would also be ellipses of different shapes depending on the angle of the sun to the earth during the particular eclipse.(Stephen Hawking and Leonard Mlodinow, A Briefer History of Time (New York, New York: Bantam, 2005) 6.)
Aristotle believed that the earth did not rotate like other bodies in the sky but instead was stationary (just like it felt) and was the center of the universe. He thought that the moon, planets, and stars moved in circular orbits around the earth. A Greek who did not agree with Aristotle's astronomical ideas lived about 50 years after him. This was Aristarchus of Samos who taught that the sun was the center of the universe with all the other celestial bodies including the earth moving in circles around it.(Id. 28) His scheme did not catch on.
Eratosthenes, who lived in Alexandria around 200 B.C.E., was the first to make a good estimate of the circumference of the earth by measuring the angular height of the sun at different places at the same time. His estimate was 29,000 miles while today we know it is 25,000 miles.(Gribbin 139)
Around 140 C.E., Ptolemy developed Aristotle's ideas in the Almagest, a thirteen-volume description of the universe. He took a scientific approach.(Id. 325) In his system, the moon and the planets were each associated with a sphere that rotated around the earth. The motion of these bodies could not simply be described by saying that each body was embedded in its respective sphere, so Ptolemy had to come up with epicycles associated with the spheres for the bodies to travel in. All the other stars seen in the sky were considered to be in one outermost sphere because their motion appeared to be in unison.(Hawking 8)
The Christian church later adopted Ptolemy's scheme, and it became heresy to believe otherwise. This was the reason that a Polish churchman Mikolaj Kopernigk (Nicolaus Copernicus) was so reluctant to publish his idea in the early 1500's that the sun was the center of the universe.(Gribbin 88) Due to his reticence, he did not suffer persecution from the Church, but it was a different story for followers of his like Galileo Galilei and Giordano Bruno.
Galileo was imprisoned and later recanted his belief in the new solar system while Bruno was more steadfast and refused to abandon the belief. He was burned at the stake by the Inquisition for this and other heretical beliefs, among them that there were innumerable inhabited worlds.("Bruno, Giordano," Encyclopedia of Philosophy, Paul Edwards, ed. in chief (New York, New York: Macmillan Publishing Co., 1967).) None of these thinkers seemed to give much thought to the nature of the stars beyond the solar system or to the idea of an expanding universe. Indeed, there would have been little basis for an expanding universe.
In 1750 Thomas Wright of Durham, England published a book, Original Theory or New Hypothesis of the Universe, in which he pointed out that the Milky Way, which had been observed for centuries, was a slab of stars, flat like a grindstone. Our sun was part of that slab but was not at its center.(Steven Weinberg, The First Three Minutes (New York, New York: Bantam, 1984) 13.) He also suggested that the nebulae or "little clouds" seen in the sky were outside the Milky Way.(Gribbin 425) Immanuel Kant picked up on this in his 1755 publication Universal Natural History and Theory of the Heavens and suggested the nebulae were other galaxies. By 1800, a number of observers accepted that the nebulae could be additional galaxies.(Weinberg 15)
Discoveries After 1900
The matter rested there until the 1910's when American astronomer Vesto Slipher discovered that shifts toward the red end of the spectrum of light were coming from some of the nebulae.(Id. 17) A light or sound source emits waves of light or sound at a specific frequency, but if the source is moving away from the observer, the frequency decreases and the wavelength elongates. Conversely, if the source is moving toward the observer, the frequency increases and the wavelength shortens. This phenomenon is called the Doppler effect. A decrease in frequency from a light causes a change in the spectrum of light coming from it toward the red end. In relation to a star or galaxy, it indicates that it is moving away from the earth.
In 1915, Einstein offered his general theory of relativity and two years later tried to describe the space-time geometry of the universe in terms of it. He could not find a solution to the equations that described a static universe. The idea that the universe was static was so set in everyone's mind, including Einstein's, that he did not allow the solutions to indicate we were in a nonstatic universe. So he introduced a "cosmological constant" that would ensure that the general theory did not show that the universe was expanding but was instead static. Later, he would call this his greatest blunder.
In 1917, Dutch astronomer Willem de Sitter and Russian mathematician Aleksandr Friedmann both came up with solutions of the field equations of the general theory of relativity that allowed for an expanding universe. Friedmann, wanting to get Einstein's opinion, did not publish his results until 1922.(Gribbin 153) Friedmann understood right away that he was dealing with a family of solutions to the equations and that each solution represented a cosmological model.(Id. 151)
In 1927, Georges LeMaitre, an ordained Belgian priest who became an astrophysics professor, published a paper showing that a solution of the equations of general relativity described an expanding universe. It was the same approach taken by Friedmann, but LeMaitre was unaware of his work. In 1946, LeMaitre developed his ideas in a book Hypothesis of the Primal Atom in which the universe began with the explosion of a sphere about 30 times bigger than the sun. None of LeMaitre's writings caught much attention in his lifetime, but the book introduced the terms "primeval atom" and "cosmic egg."(Id. 242) It is Friedmann's models that cosmologists later studied.
Actually, the scientists from the time of Newton onward should have realized that the universe had to be expanding. Based on Newton's theory of gravity, if the universe had been stationary at any time, or even just expanding slowly, the force of gravity of all the stars in it would have caused everything to contract back to a center.(Hawking 58)
In the 1920's, American lawyer turned astronomer Edwin Hubble and other astronomers observed through their telescopes that the galaxies were almost all moving away from the earth. Furthermore, in 1929 Hubble published the finding that the farther away a galaxy was from the earth, the faster it was moving.(Id. 57) Most astronomers became convinced that the universe was expanding and that meant there had to be a beginning.
Disreputable Territory
Physical scientists, however, did not work much on the problem of the origin of the universe. Steven Weinberg, Nobel Prize winning physicist, mentioned this in The First Three Minutes. It was published in 1977 and was the first book to ever try to describe the earliest time of the universe. He had this to say:
[A]n aura of the disreputable always surrounded such research. I remember that during the time that I was a student and then began my own research (on other problems) in the 1950's, the study of the early universe was widely regarded as not the sort of thing to which a respectable scientist would devote his time. Nor was this judgment unreasonable. Throughout most of the history of modern physics and astronomy, there simply has not existed an adequate observational and theoretical foundation on which to build a history of the early universe.Now, in just the past decade, all this has changed. A theory of the early universe has become so widely accepted that astronomers often call it "the standard model." It is more or less the same as the "big bang" theory . . . . .(Weinberg 2)
In the late 1940's, one physicist who ventured into disreputable territory was George Gamow. He was probably motivated by his interest in the subject when he was a student of Friedmann at the University of Leningrad. He and his students, Ralph Alpher and Robert Herman, showed that protons and neutrons in the Big Bang would have produced primordial helium. They also claimed that weak microwave radiation left over from the Big Bang should fill the universe.(Gribbin 166) These ideas made no impression on the astrophysical community.
In the 1940's, another interesting development took place--the formation of the Steady State Hypothesis by Fred Hoyle, Hermann Bondi, and Tommy Gold. They did not quarrel with the idea of the expansion of the universe. Hoyle's scientific approach tried to show that galaxies are being created to take the place of those moving out. By the late 1960's, that hypothesis was proven false with the mounting evidence for a dramatic beginning.(Id. 383) Hoyle was the one who coined the term "Big Bang" with derisive intent. His discomfort with the Big Bang model came from its feature that the universe started in a singularity, a tiny point filled with all the energy and mass later found in the universe.(Id. 207) Inflation theories developed since 1981 have removed the need to posit a singularity.(Id. 383)
The Cosmic Background Radiation
Nothing dramatic happened in cosmology until 1965. Physicists Arno Penzias and Robert Wilson were employed at Bell Telephone Laboratories and decided to do some radio astronomy with an antenna designed to work with satellites. It was sensitive to radio waves as well as to microwave radiation, which are both part of the electromagnetic spectrum. The measurements they wanted to make were precise, and so they had to eliminate as much extraneous noise as possible. They found that there was some noise they could not eliminate. It occurred at all times of the day and night and came from every direction. They cleaned the antenna of pigeon droppings that could possibly be causing the problem, but it didn't help much. They consulted with two physicists from Princeton who told them it was the microwave radiation left over from the Big Bang and that they themselves had been preparing an antenna to try to find it.(Hawking 61) The radiation was further tested and confirmed.
Penzias and Wilson measured the microwave radiation to be at an "equivalent temperature" about 3.5o Kelvin.(Weinberg 43) This temperature reading does not mean that the temperature at an antenna picking up radiation gets very cold or anything like that.(See Weinberg for an explanation of "equivalent temperature.") On the Kelvin scale, 0 is absolute zero, the lowest temperature that can be attained. It corresponds to -273 degrees on the Celsius (centigrade) scale. The magnitude of a degree on each scale is the same. Gamow and his colleagues had come close in 1948 when they predicted it would be 5o K.(Id. 46)
The National Aeronautics and Space Administration (NASA) in the U.S. later launched two satellites, the Cosmic Background Explorer (COBE) and the Wilkinson Microwave Anistropy Probe (WMAP). They were supposed to determine any fluctuations of the cosmic microwave background radiation, which can tell scientists much about the initial conditions of the universe. The information sent back confirmed that the universe was once much hotter than it is today.(John Barrow, The Origin of the Universe (New York, New York: Basic Books, 1994) 13.) Scientists wrote numerous papers based on the findings of the two probes. The WMAP satellite had instruments that could detect temperature fluctuations less than one millionth of a degree. It was launched in 2001 and had traveled more than a million miles by 2006.
Ground Zero
Here follows a likely scenario of what happened at the very beginning of the universe. All the details are not known and not all cosmologists are in agreement.
Time: 0
Temperature: unknown
The first era is known as the Planck Era. It is assumed that at the very beginning all forces were unified.("Cosmology," Discover Science Almanac 90.) At the point where everything was contained in a tiny quantum object, it could have undergone random fluctuations. It could have been supercooled. One fluctuation could have had profound effects. It could have created particles, although they would have been different from the ones we know today.(Id.) The fluctuations could have been unpredictable and particles could have gone in and out of existence somewhat like they do today. For this reason, the Planck Era has been described as a writhing foam.(Voyage Through the Universe: The Cosmos (Alexandria, Virginia: Time-Life Books, 1988) 105, hereinafter The Cosmos.)
In spite of much effort, scientists have not been able to come up with a theory that shows how all the forces could have been unified. It appears that to do this it would be necessary to reconcile quantum mechanics with the general theory of relativity. The combined theory has not yet been established but has already been given a name: the quantum theory of gravity.(Hawking 102) It appears the quantum theory of gravity requires more than four dimensions. String theory has been given a very close look because it posits a universe with 11 dimensions, give or take a couple of dimensions depending on the variant of the theory.
Supposedly, the reason astrophysicists can trace events to the beginning is that they can tell with accuracy what the temperature was at different time points at the very beginning. This in turn gives them a good idea what was going on with respect to energy and matter at the corresponding time. Yet, we have to live with the very small period of ignorance between the Bang and 10-43 second.
Planck Time--10-43 Second
Time: .0000000000000000000000000000000000000000001 second
Temperature: 100,000,000,000,000,000,000,000,000,000,000o K
The earliest time that cosmologists can study is 10-43 second. The temperature was 1032 degrees Kelvin. Both figures are set out in common notation above. That was 10 trillion trillion times hotter than the core of an average star.(The Cosmos 120) If you want to know what 1032 degrees K is in Fahrenheit, the conversion formula is F=K-241.15. For Centigrade measure, the formula is C=K-273.15. At such a high temperature, the three different temperature scales do not yield very different numbers for the temperature.
That scientists can make any credible estimate of what went on at that time in the life of the universe is amazing, but of course, they would like to go farther back. It is believed that right before Planck Time gravity and mass appeared. Gravity was the only force.("Cosmology" 91) There were quarks, leptons, and bosons, the force carriers for each of the fundamental forces. There were also leptoquarks and antileptoquarks, which disappeared after being turned into quarks and leptons. Quarks were turning into leptons and then back into quarks.(The Cosmos 120) Components of energy and matter were colliding violently against each other. Photons, the form of light, carried the electromagnetic force. There were no protons, neutrons, or electrons--the constituents of atoms.
There were also unknown particles. Under the conditions, photons were interchangeable with particles in accordance with the well-known physical law E=mc2 which shows that energy and matter can be converted into each other. Particles disappeared in collisions that created other particles. The newly created particles could then possibly vanish in other collisions that would create other particles. It was unknown what particles would be produced by a crash between the colliding particles. An impact between particles of the very same kind could yield different results each time.(Id.)
If you had been there to witness this, you would have seen nothing for two reasons. First, everything was so dense that the photons that were needed to move far enough to produce light could not travel. The universe was completely opaque and remained so for eons. Second, at those temperatures you would have been vaporized as soon as you were created. The positive thing is that you would not have felt a thing.
There was about an equal amount of antimatter as there was matter. Paired particles of opposite charge were annihilating each other at an astounding rate. Cosmologists say there was a very slight excess of positive matter from which the universe was eventually made. (Why they never assume we were made of excess negative matter is not clear.) This time has been called the GUT (Grand Unified Theory) Era because the forces were almost all unified. At this time, the mass of the cosmic soup was so dense that a cluster of galaxies could have been stuffed into a hydrogen atom.(Id.)
Inflation Era
Time: .00000000000000000000000000000000001 second
Temperature: 1,000,000,000,000,000,000,000,000,000o K
At 10-35 second, the Inflation Era began. The temperature dropped dramatically, but the total energy of the universe grew, causing a tremendous expansion. The volume of space increased more than a trillion trillion times.(Id. 122) The Inflationary Period ended with the universe still only the size of a grapefruit.("Cosmology" 91) This period was proposed in 1980 by Alan Guth. It seems like a fantastic event, yet WMAP observations seem to support such an occurrence. Other variants of the theory have also been proposed. The idea gained acceptance because it helped explain some puzzling questions that had arisen, including how galaxies could form. If the universe had expanded uniformly from the beginning, each atom would have receded from all the other atoms too rapidly to allow for clumps of matter to coalesce. It follows that those giant clumps of matter known as galaxies would have never taken shape.
There were now two forces, gravity and a combined force. The latter would later split into the color, electromagnetic, and weak nuclear forces. Color would later produce the strong nuclear force.(Id. 91)
The Electroweak Era
Time: .000000000000000000000000000000001 second
Temperature: 100,000,000,000,000,000,000,000,000o K
H Higgs bosons appeared at 10-33 second dividing the combined force into the three remaining forces. Leptons and antileptons broke down into electrons and positrons, respectively, as well as into neutrinos and antineutrinos which are subject to the weak force. The mass of objects was such that the earth could have fit into a thimble.(The Cosmos 124)
The Quark Confinement Era
Time: .000001 second
Temperature: 10,000,000,000,000o K
Much, much later (relatively speaking) the energy level became low enough that the formation of certain particles with which we are more familiar could take place. The time was now 10-6 second. Gluons, the carriers of the strong force, were now able to unite quarks into protons, neutrons, and their antiparticles.(Id. 126) Some neutrons decayed into protons, so there came to be more protons than neutrons. Matter and antimatter continued to annihilate each other but did not produce other matter as before. Instead, they produced photons. These photons blocked the production of proton-electron pairs, which in turned prevented the formation of atoms. Although the energy level was much lower, it was still a million times hotter than the core of our sun today.
Paul Steinhardt and Neil Turok said their alternative theory of a cyclic universe that has been going forever was in agreement with the standard Big Bang model with the exception of the first second.(Paul J. Steinhardt and Neil Turok, Endless Universe: Beyond the Big Bang (Phoenix, 2008, ISBN 978-0-7538-2442-9.) Much happened in that first second.
The Neutrino Era
Time: 2 seconds
Temperature: 10,000,000,000o K
The creation of electrons and positrons that had started during the Electroweak Era ceased because of the lower level of energy. Neutrinos and antineutrinos stopped interacting with other particles.(The Cosmos 124) Neutrinos and antineutrinos are chargeless and almost massless so they became almost impossible to detect, yet they are ubiquitous still today. Traveling at the speed of light, billions of neutrinos pass through the earth and through our bodies every day. If scientists set up instruments to detect them, billions pass through detectors but only a handful are stopped. It is suspected that they may constitute what is called dark matter in the universe.
The Nucleosynthesis Era
Time: 1 minute
Temperature: 1,300,000,000o K
At this point, the energy of photons diminished to the point where they could no longer prevent protons and neutrons from combining to form atomic nuclei. One proton and one neutron form what is called a deuteron, which is identical to the nucleus of deuterium, an isotope of hydrogen. Hydrogen also has one proton in its nucleus but not a neutron. Another combination is two protons and one neutron. They make a helium-3 nucleus.
The most common nuclear combinations were varieties of hydrogen and helium nuclei. Hydrogen and helium are the elements we find most in the universe today. The photons still had enough energy to prevent the positively charged nuclei from combining with negatively charged electrons to form atoms.
At three minutes, the density of the universe was like that of water.(Id. 128) After five minutes, the temperature had cooled enough to reduce the energy of photons so that they were less able to prevent protons and neutrons from combining. The subsequent combining formed the atomic nuclei of varieties of hydrogen and helium. No nuclei of other elements (except lithium) were formed for perhaps a billion years. Photons retained enough energy to knock away any electrons that tried to combine with the atomic nuclei that had been formed. This prevented the formation of complete atoms. It was still hot enough to prevent atomic nuclei with a greater number of protons and neutrons than those of hydrogen and helium from taking shape.(Id. 136)
At this time, the number of neutrons was only 14% of the number of protons. The two particles had been equal in number when they were born, but collisions with electrons and positrons had been less kind to neutrons.(Gribbin 55) The atomic nuclei of helium had been synthesized and made up 25% of the nuclear material in the universe. Everything else was lone protons, which also happen to be hydrogen nuclei. The time during which protons and neutrons combined is called the Nucleosynthesis era. It lasted four minutes starting after minute one and ending after minute five.
Coalescence of the Atoms
It took the passage of 300,000 years for the formation of atoms to begin. This happened after the photons started to weaken so that they gradually interfered less with the electrons. The photons weakened because the temperature had fallen to 3,000o K.(Illustrated Encyclopedia of the Universe (New York: Watson-Guptall, 2001) 128.) This atom formation took place over approximately the next 500,000 years.(Gribbin 56) Still, this only involved the atoms of three elements--hydrogen, helium, their isotopes, and a slight bit of lithium, which was the heaviest atom of the time. It has two neutrons, three protons, and three electrons.
The formation of the atoms marked the transition from the Radiation era to the Matter era. Radiation did not again have any significant interaction with matter. It is said that they "decoupled."(Gribbin 56) All the preceding is set out in the Big Bang theory, which is widely accepted except for some details. In turn, it draws on the well-established general theory of relativity and the knowledge of nuclear interactions.
The Matter Era
Time: 1,000,000 years
Temperature: 3,000o K
The cosmic plasma fog that had filled the universe had occurred because the photons were colliding with the free electrons in space. With more electrons out of the way because they were combining with nuclei to make atoms, space became transparent.(The Cosmos 130-131) Some believe that this era began much earlier, perhaps as early as 400,000 years. Hydrogen, helium, and some lithium continued as the only elements.(Id. 131)
In 2005, there began some change in what was imagined the beginning looked like. A three-year study greatly surprised the researchers involved. It had always been assumed that the universe started out as a hot, dense cloud of gas with quarks and gluons flying wildly in every direction. The study involved hundreds of scientists, mostly physicists, collecting data at the Brookhaven National Laboratory on Long Island, New York. Using the atom smasher known as the Relativistic Heavy Ion Collider (RHIC), the researchers sent charged gold atoms at near light speed through a tunnel. A fireball was produced with a temperature 150,000 times that at the center of the sun. This was supposed to simulate the conditions in the universe at the very beginning. Instead of a chaotic soup, they witnessed particles flow together in coordinated streams. It resembled a perfect fluid. By 2020 it appeared that a 4 trillion degree quark-gluon plasma permeated the early universe.
On to the Stars (Suns)
It would be about another million years before any stars could begin to take shape. There is disagreement on the time that stars appeared as well as on how they fused the various elements, but there is a general picture. Galaxy formation may not have begun until 1 billion years after the start of it all.(Encyclopedia of the Universe 128) Little is known about what happened during star and galaxy formation. Much more is known about the first five minutes of the universe.
Stars are spawned from large, cool, dense clouds of gas and dust in space. This is a gradual and difficult process. While gravity is working to collapse the cloud into a smaller body, there are other forces working against that. First, heat may build up in the cloud from radiation from nearby stars, and this heat may build up considerable outward pressure. Then there are magnetic fields, and if the cloud is rotating, there is centrifugal force. A cloud that does start to collapse breaks up into fragments that warm up on account of the heat producing gravitational energy involved.
After a certain point of heat build-up, the fragments become precursors of stars, protostars. A hot core forms in each fragment after about 100,000 years of continuing collapse. A protostar may become surrounded by a disc of matter, especially if it is solitary as opposed to one paired with another protostar in what is called a binary system. The surrounding matter can later form planets. After the interior temperature reaches at least 10 millionoK, nuclear fusion reactions begin, and it becomes a stable star. Stars with similar mass to our sun reach this point after about 50 million years. More massive stars reach that point more quickly and smaller ones take longer.(Gribbin 380)
The lifetime of a star depends only on its mass. The more massive the star, the shorter its life span. Our sun is neither among the most massive nor the smallest. It is predicted that it will last a total of 10 billion years. It is middle-aged, since it came into being about 4.6 billion years ago.(Id. 19)
The elements besides the first three had to wait to be formed inside of stars only after the stars developed hot cores.(The Cosmos 131) Nucleosynthesis in stars does not take place until the temperature at the core reaches about 10 milliono K. It takes some time from the birth of a star for it to reach this temperature.(Id.)
At the time of atom formation starting at 300,000 years after the Big Bang, gas shown brilliantly for a time. It eventually turned into the cosmic background radiation of radio waves detected in 1965. Radio waves do not shine in any way and so the matter that was left behind was dark and cold.
Galaxies
At the universe's age of 300 million years, the gravity of that dark matter began to pull the gas into narrow regions that were separated by huge empty voids. The gas later formed the first galaxies.(Heather Couper and Nigel Humbest, D.K Space Encyclopedia (New York: D.K. Publishing, Inc., 1999) 228.) The composition of the universe at the time was 77% hydrogen, 23% helium, and a very minute amount of lithium.(Id. 224) Those proportions of the three elements are still the same today.
Galaxies were mostly formed by colliding clouds of gas.(Id. 229) This of course took place on a very large scale. There are different forms that galaxies take. There are spiral, elliptical, and irregular ones. Our galaxy, the Milky Way, is a spiral one. Our star is not near the center as was once thought. It is situated well away from the center on one of the spiral arms. The Milky Way is 100,000 light-years across and 2,000 light-years thick. It has been flattened by its rotation. It orbits around its center, taking 220 million years to complete one revolution. It appears to be 12 billion years old based on the age of its oldest star clusters.(Id. 194-195) In the 1990's, it was learned that galaxies merge with and absorb one another.(Gribbin 160) Most star formation occurs in disc galaxies. Elliptical galaxies are created from the merger of two disc galaxies, which is the reason ellipticals are often much larger than disc galaxies.(Id. 161)
Bright stars, like our sun, use nuclear fusion that converts hydrogen into helium.(Id. 261) The specific type of fusion is the proton-proton reaction in which two hydrogen protons combine and eventually produce a helium-4 nucleus and two protons. This is what generates energy from a star.(Id. 324) We know that this is made possible in our sun because it is about 70% hydrogen, 28% helium, and 2% heavy elements.(Id. 325)
In the process of collapse, some stars don't make it to the point where they can generate nuclear fusion reactions. This happens in the cases in which the mass of the star is less than 8% that of our sun. These are called brown dwarfs and burn faintly for about 100 million years due to gravitational energy.(Gribbin 69)
Stars as Ovens for Elements
The stars have produced all the elements besides the first three through what is called stellar nucleosynthesis. One could say the stars, which are themselves made of elements, have been nuclear ovens for the manufacture of all the other elements. All these elements have gone on to comprise everything: planets, moons, comets, and living things including us.
The process has depended on the helium-4 nucleus that under the proton-proton reaction is produced abundantly. The helium-4 nucleus joins with other nuclei to produce elements in steps of 4 atomic mass units. Carbon-12, for instance, was an element that was abundantly produced since it took the fusion of three helium-4 nuclei to make it. Other elements and their isotopes were made by this fusion up to iron-56 with energy being produced with every reaction. Fred Hoyle and the team of astrophysicists he led learned all this in the 1950's.(Id. 297)
Elements heavier than iron cannot be produced by fusion because their construction requires taking in energy rather than giving it up, as with lighter elements. One way these heavier elements are produced is through supernova explosions where the gravitational energy from the collapsing core of a star allows nuclei to quickly capture neutrons.(Id. 298) Copper, zinc, and iodine are heavier elements that are found in our bodies. This means they were transported to our cosmic vicinity for millions of miles from a distant supernova explosion. This had to have happened before the formation of the sun and earth.("Cosmology" 92)
It seems hard to believe how astrophysicists could find out about the production of elements since they were not able to observe stars forming them. The scientists were able to come up with solid conclusions because they were able to experiment with the process using particle accelerators and because they have been able to get a good inventory of the abundance of elements in the universe today. Calculations on how they were formed are consistent with these two methods.
Our Solar System
Our solar system formed in much the same way as the billions of other solar (star) systems, as described before. A nebula of dust and gas was ambling along until a disturbance occurred. A supernova, an explosion of a large star, could have caused this change. Such an explosion can be felt for a long distance, and it spreads the many elements created inside the star. The disturbance started the nebula spinning around. Gradually clumps began to appear while the cloud slowly flattened into a disk-like shape as it spun around. The larger clumps eventually formed into the planets while numerous sizable clumps continued to fly around. The paths of all these clumps were not set apart neatly, so as to not cross each other; there were ongoing collisions.
The densest clump settled in the center of the nebula and became the sun. The clumps flying around and crashing freely into other bodies were named asteroids and are still flying around in varying sizes. Most of them have orbits between Mars and Jupiter but some cross the earth's orbit. Some hit the earth and a big one could cause extensive damage. Comets are icy objects that orbit well beyond the outer edge of the system, in what is called the Kuiper belt.(Smithsonian Earth, James Luhr, ed. (New York: DK Publishing,Inc., 2003) 25.)
The sun blew a solar wind consisting of energetic particles toward the planets. This carried hydrogen and helium to the outer portion of the solar system.(Id.) This left little of the two gases for the inner planets--Mercury, Venus, earth, and Mars--so they developed as rocky planets with hard surfaces. The four outer planets--Jupiter, Saturn, Uranus, and Neptune--became gigantic gas planets consisting mainly of hydrogen and helium. Their surfaces are soft. The gas composition gradually becomes denser toward their interiors.
Our solar system came into existence about 9 billion years after the Big Bang. This is under the latest estimate by astroscientists of the age of the universe as 13.72 billions years and of the age of the solar system as 4.57 billion years. The sun and planets were likely formed at about the same time. The earth was probably formed from the collision of protoplanets that came into existence with the protosun. The protoplanets melted completely from the heat of the collisions and then the planets coalesced from the melted material.("Cosmology" 91) Based partly on the study of similar stars, the sun has a likely lifetime of 10 billion years.
Contemporary Problems
There are disturbing problems on earth that threaten the well-being of living things as well as the longevity of some species, possibly even the human species in the long run. They are physical problems. Just two of them are pollution and global warming. More narrowly, these problems are chemical in that they involve elements and compounds in the environment that can cause biological harm to living things.
Two important types of pollution involve air and water. Chemicals in the air like ozone, nitrogen oxides, sulfur dioxide, and carbon monoxide can cause physiological problems for children, the elderly, and those with lung and heart disease.("Pollution," Discover Science Almanac, (New York, New York: Hyperion, 2003) 629.)
Water pollution in addition to threatening human health directly through contaminated drinking water. Microorganisms like bacteria can breed in drinking water and bring diseases like cholera, typhoid fever, and hepatitis A. Fish can eat heavy metals like mercury, arsenic, chromium, and cadmium. Humans can then eat those fish to their detriment.(Id. 637) There were warnings issued for several years about eating too much tuna because it contains dangerously high levels of mercury. This metal poses a special risk for fetuses.
Global warming has gained great attention as a threat that could have serious long-term consequences. It has been noted that glaciers in or near the Arctic are melting and could eventually bring dangerously high sea levels to coastal cities. Warmer temperatures cause problems for many species that then have to migrate to more hospitable areas. It also means that as one species moves away or dies because of climate change, another species depending on the first for its food may become extinct.
Global warming is caused by humans and other large animals through the gases they produce which rise upward and stay in the atmosphere, trapping the heat trying to escape from the surface. Some of the gases involved are carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), ozone (O3), hydrofluorocarbons, and perfluorocarbons. Carbon dioxide is the most abundant and is produced by the burning of fossil fuels and other materials like wood.("Global Warming," Discover Science Almanac 603.) In addition to the threats of pollution and global warming, there is the continuing threat to the living things on earth from nuclear weapons. The fission and hydrogen fusion bombs are based on the questionable use of clearly established physical laws.
The Future of the Earth and Sun
What is going to eventually happen to the earth? The life of the earth is closely tied to the fate of the sun. It is believed that the sun will continue functioning as it does now for another 5 billion years. Stars with high mass last only a few million years, while stars with low mass go on for hundreds of billions of years.(William Kaufmann III, Universe (New York, New York: W.H. Freeman and Company, 1985) 393.) The mass of our star is in between. What determines how long a star lasts is the length of time it takes to burn the hydrogen in its core.
Once our sun burns all the hydrogen in its core, it will eke out a few more million years by burning the hydrogen contained in a thin shell surrounding the core. More helium (produced by the burned hydrogen) will be added to the core, which will contract and become hotter. The helium nuclei will begin to fuse into carbon nuclei.
Somewhere about this time, the increased heat of the sun will make it too uncomfortable for living things to survive on earth. It is uncomfortable enough now when temperatures pass 100o on some summer days. Even if humans could build huge dwellings underground where it is always cooler, would it be cool enough and how would they produce food? Where would oxygen cool enough to breathe come from?
After a few million years, the sun's core will become compressed to about one-fiftieth of its original radius and increase in temperature from 15 million degrees K to 100 million degrees K. The sun will become hot enough that the energy produced will cause its outer layers to expand with the boundary reaching beyond the orbit of Mercury. It will lose about a quarter of its mass by ejecting some of its material into space, which will form a nebula. The temperature of the surface will fall from 5,800o K to 2,300o K (Kaufmann 395) but that will not make it any more comfortable on earth.
The sun will now join the class of red giants. It's size will be so great that it will be 100 times brighter than it is today. The sun will last only 1 billion years as a red giant.(Gribbin 385) Stars of similar size go through the same process in their waning lives. The inner planets will be vaporized, and the gaseous atmospheres of the outer planets will be boiled away leaving relatively tiny rock cores.(Kaufmann 395) Large stars see a different end, often exploding into supernovae.
After the red giant stage ends, the sun will become a white dwarf with a mass about half of what it is today. The core will probably be carbon and oxygen with an atmosphere of hydrogen. It will be a cinder rich in carbon.(Gribbin 386)
The Universe Expanding Onward
Scientific discussion about what might be the fate of the universe started in 1850 after Rudolf Clausius came up with the idea that heat energy systems, such as machines, always seem to go to a state of greater disorder. Machines tend toward disorder and eventually break down. There are a number of natural processes that also seem to go to greater disarray. Clausius called this progression to a greater disorder "entropy," and the idea became known as the second law of thermodynamics.(Barrow 23)
He and others began to consider the universe itself as a closed energy system and conjectured it might in the far future reach a state of maximum possible disorder and not recover but instead remain in a "heat death". All that would be left throughout the universe would be uniform radiation. This also caused some speculation in 1873 by British philosopher of science William Jevons that there must have been a beginning to the universe when there was maximum possible order.(Id. 24) In the 1930's astrophysicists Arthur Eddington and James Jeans introduced the general public to the notion of a steady dissolution into a "heat death of the universe" in popular books they wrote.
Aleksandr Friedmann's exploration of the equations of general relativity not only invited consideration of its origin but also of its fate. There are three basic cosmological models that come out of the equations, but there can be other variations. All models present an expanding universe that started with the Big Bang.
The first model has the universe expanding to a certain point and then collapsing again to its original state in a Big Crunch. There are two possibilities at that point. Either the universe ends in that state, or it starts to expand all over again. This latter scenario is the one that some religious seekers in the East proposed centuries ago. It is an oscillating universe where everything is destroyed only to rise up from the ashes. It comes about if there is enough matter in the universe to produce a gravitational pull that overcomes the expansion and brings on the contraction.
The second model shows the expansion proceeding and then slowing gradually to a point where it stops and remains there. This means there would be just enough matter to bring about a gravitational brake on the expansion but not enough to provoke a contraction.
In the third model, gravitation is too weak to stop the universe from expanding indefinitely. Based on the latest astronomical observations, it appears this is the model the universe is following. In 1998, astronomers observed that the universe was expanding at an accelerating rate. This has become accepted as correct.
This accelerating expansion has helped bring about a picture of the universe that posits that there is much more than the regular matter seen around earth and through telescopes in space. Regular, visible matter is sometimes called bright matter. It can be detected through electromagnetic means. Astronomers first started seeing evidence of additional matter in our galaxy in the 1930's when they saw stars that bobbed up and down slightly. The presence of additional matter would explain this movement, but it could not be detected through any instrument. This dark matter also explains the way other galaxies rotate and the way they have gathered in clusters.(Gribbin 105) The composition of dark matter is not clear. Astroscientists have been busy trying to figure that out for a long time.
The discovery that the universe seems to be expanding at an accelerating rate forced the search for an explanation, and it now seems there must be something else out there in addition to the dark matter. It has received the name dark energy.("R&D: Astronomy and Cosmology," Discover Science Almanac 30) It does not seem to have been very abundant when the universe was young but is now propelling the acceleration. There is not much known about what it is. One thing that appears clear is that the bright matter with which we are familiar constitutes only a small part of all of the matter-energy out there-perhaps 4%! Dark matter makes up around 24% and dark energy 72%.
The way the universe is going it looks like tens of billions of years from now the galaxies will move very far apart from each other. If perchance there are any observers left in our galaxy, they will not be able to see other galaxies. Our sun will be a white dwarf.("Cosmology" 92) A hundred trillion years from now, all the stars will be burned out. The large stars will be black holes, and the others will be cinders radiating no energy. There will be no visible light or other radiation at a higher frequency. There will be a little infrared or lower radiation in individual atoms.(Id.)
A trillion trillion trillion trillion trillion years from now, any matter left will fall into black holes. There will be no radiation, leaving everything black at all wavelengths. As in the beginning, there will only be the force of gravity.(Id.)
It has been shown that the rocks, seas, and atmosphere that make up the earth are made of elements, compounds, and mixtures (the last two in turn made of elements). Furthermore, these elements were made through the process of nuclear fusion in stars. It is widely accepted that the celestial bodies seen throughout the universe are physical in that they are made of the chemical elements. Some people believe that humans enjoy a special status and are also made of a special substance called spirit.
This chapter will delve into what living things are made of and whether that material is different from that found in inanimate objects like rocks. It will be instructive to probe further into living things by examining their structure and how they are able to stay alive. It will also be enlightening to see some of their interrelationships and to examine how it was that they developed on this earth.
What is Life?
Unfortunately, there is no simple, universally accepted definition of life. It involves some characteristics like responsiveness to stimuli, stimulability. A living thing like a plant grows when it has access to a regular supply of water, and it may even move in the direction of the source of the water. A cockroach may react to light and a snake may respond to heat. The prick of a pin by causing pain can bring a reaction in an insect, a fox, or a human. An extensive and permanent response to stimuli can be what is called an adaptation.
Growth is another characteristic observed in living things. They go through a life cycle from birth through youth, middle age, old age, and finally death, which seems to be the fate of all life. Living things need some form of nutrition to sustain them, but they do not simply ingest food. They are capable of breaking it down and transforming it to serve their own needs.
Another common characteristic is that living things are able to reproduce their own kind but not any other kind. Nonliving things cannot produce living things although it was once believed that this happened in some instances. Educated men taught, on the basis of their immediate observation, that aphids were produced by dew on plants, that maggots were produced by decaying meat, and that the mud of the Nile River spawned fish.("What is Life?" New Book 375.)
A final fact that sets life apart is its composition. Living things are made of cells that are made of most of the same elements and compounds. Viruses do not have cells and are not made of the same material. For this reason, there is a widespread opinion that they should not be classified as living things.
Chemical Constituents of Life
Chemists have been analyzing living things or their remains for over two hundred years and have found that they are made of hundreds of elements and compounds. The main constituents have become widely known since they are often discussed in the media and in the many diet books that are continually being published. These are proteins, carbohydrates, fats, vitamins, and minerals. There are also water (the most important of all), nucleic acids, and salts. Water makes up 60 to 90 per cent of living bodies. It is essential in many ways, including as a solution for many materials.(Id. 380)
The consistency of a living body can vary considerably. It can be liquid, jellylike, or solid as in the case of bone. The variation in consistency can show up between different plants and animals and between different parts of the same plant or animal. There are almost thirty chemical elements in living things.(Id.) It was estimated that in 1998 the approximate market price of all the elements in the human body was $9.95.(Robert Krebs, The History and Use of Our Earth's Chemical Elements (Westport, Connecticut: Greenwood Press, 1998) 2.)
Carbon is found widely and could be said to be the most essential element to living things. It is not found in water, and water is the most essential compound to living things. Oxygen and hydrogen make up water, and they are the next two most abundant elements in living things. Nitrogen follows after that. These four elements are found in a vast number of organic molecules. Organic is a collective name for something derived from living or once living things. Adding the elements phosphorus and sulfur completes the group of elements that are most involved in the molecules found in living things. A mnemonic for remembering these six elements is CHNOPS.(Hazen and Trefil 209) Some other elements found in living bodies are potassium, chlorine, sodium, calcium, magnesium, copper, and iron.("What is Life?" 380)
Proteins
Proteins are the building blocks of living matter. Very appropriately, the name comes from the Greek proteios, meaning of first importance. They perform many functions among which the most important are the following:
1. Structure. In animals, structural proteins are the chief ingredients in skin, bone, hair, and nails. Two important structural proteins are collagen and keratin.
2. Movers. Muscles that are composed of the protein molecules myosin and actin carry out every movement we make.
3. Enzymes. Enzymes are proteins that speed up virtually all reactions in living bodies so that the reactions can be useful.
4. Hormones. Many hormones are proteins, e.g. insulin and oxytocin.
5. Transporters. A large number of proteins are involved in transportation. Hemoglobin, for instance, operates in the blood to move oxygen from the lungs to the cells for utilization and transports the waste product carbon dioxide from the cells to the lungs for release into the air.
6. Protection. Sometimes a foreign protein will invade the body. To fight these intruders the body will make its own proteins known as antibodies. Fibrinogen is a protein that will ensure there is clotting of blood; otherwise, we would bleed to death from a small cut.
7. Storage. Some proteins are used to store materials. An example is ferritin which stores iron in the liver.
8. Regulation. Proteins through their control of genes regulate the manufacture of other proteins in the cell.
A typical cell has about 9,000 different proteins, while an individual human being has about 100,000 different proteins.(Bettelheim 508)
Proteins contain hundreds, sometimes thousands, of molecules of amino acids. There are hundreds of amino acids but only twenty are found in living bodies. It is clear that the many possible combinations of these twenty amino acids can produce a large number of proteins. Proteins composed solely of amino acids are called simple proteins. Complex proteins can be constructed of amino acids and other matter like carbohydrates and phosphorus. Each amino acid contains an amino group, -NH3, and a carboxyl group, -COOH, with links to other amino acids.("Cells," New Book 384.)
There are some interesting facts about exactly how amino acids combine to form the different proteins needed by living bodies. A person does not have to ingest all the amino acids that make up a specific protein at the same time. As long as enough of all the amino acids needed to make a protein are ingested regularly, the cells combine them to constitute the protein. It is important that the cell arrange the amino acids in the proper number and order so as to come up with the specific protein desired. Each different protein has a different number and order of amino acids.(Stephen Kreitzman, "Biochemistry," New Book 426, 427.)
This unique number and order for each protein is called its primary structure, which is involved in determining the special functions of the cell and how they are carried out. The string of amino acids involved in each protein is folded and twisted in a unique way that also helps determine the special functions of the cell. This twisting is called the secondary structure. A string can have an extra-complicated structure through complicated folding with some parts open and others hidden. This contributes to the protein's unique functions and is called the tertiary structure.
Enzymes are large protein molecules that are very important for the functioning of the body. They facilitate chemical reactions at temperatures much lower than what is normal, and they control the speed of chemical reactions.(Id. 428) Enzymes have a very specific function. For each of the thousands of chemical reactions that take place in a human body everyday, there is only one enzyme that aids each reaction.(Hazen 209) Molecules that regulate inorganic chemical reactions are called catalysts.
Carbohydrates
Carbohydrates provide energy for bodies. They are the most abundant carbonic compounds in the plant world. They are widely known as (1) storehouses of chemical energy, but they are also (2) part of supportive structures in plants (cellulose) and animals (shells and connective tissues), and (3) essential components of nucleic acids.(Bettelheim 440) Carbohydrates are constructed of carbon, hydrogen, and oxygen with the proportion of the latter two being two to one, the same as water, H2O. For this reason, they are thought of as hydrated carbons. Carbohydrates often unite with proteins or minerals such as sulfur or phosphorus to form complex molecules, including nucleic acids.("Cells" 385)
The carbohydrate glucose, C6H12O6, is an important simple sugar (monosaccharide) used in many hospital intravenous solutions to provide energy when the patient has problems eating. Monosaccharides can combine to form polysaccharides. ("Cells" 385) Two well-known disaccharides are sucrose and lactose. Sucrose is table sugar, while lactose is found in milk. Starch is a polysaccharide that is stored in granules and is an energy reserve. Cellulose is the principle fiber in plants, which gives them their stiffness.(Hazen 212)
Lipids
Fats or lipids are part of the structure of cells, which makes it hard to lose weight. It is also a source of reserve energy, standing by to go into action after sugars have been depleted. Lipids make good material for cell membranes because they do not dissolve in water.
Glycerol and the fatty acids make up the simple lipids. Some complex lipids are phospholipids found in nerve cells, steroids, and lipoproteins. Certain steroids work as hormones regulating functions of the body.(Id.) Lipoproteins are linked to protein molecules and have become better known recently because low-density lipoproteins are involved in unhealthy deposits in coronary arteries. High-density lipoproteins are beneficial to the cardiovascular system.
Ions
Ions from salts and minerals are found in cells. The ions appear separately in the water of the cells and not in the combined form in which they are found in salts. The right amount of each ion must exist in the cell fluid in order to keep the necessary balance between them. Ions are from sodium, calcium, magnesium, potassium, and chloride. The same delicate balance of concentrations of ions occurs in body fluids as in ocean water. Scientists believe this is one of the clues that life began in the oceans. Sodium ions are the most abundant.("Cells" 385) Potassium and calcium play an important part in the conduction of nerve impulses and in the contraction of muscles. Calcium also speeds up the action of certain enzymes. Magnesium is an important part of chlorophyll. Iron, copper, zinc, and sulfur are part of various enzymes. The phosphate ion forms a bond with lipids, proteins, and sugars that are an important source of energy.
Carbonic Compounds
Organic chemistry is the subfield of chemistry that concentrates on the study of elements and compounds found in plants and animals--dead or alive. The chemical study of minerals is inorganic chemistry, and chemists delved in it before turning their attention to organic matter. In organic chemistry, it was realized that all the compounds contained the element carbon. For that reason, the area could be called carbonic chemistry, but the organic label has stayed. A carbon atom has four electrons in its outer shell and room for four more. This allows it to make covalent bonds with four electrons from other atoms. The simplest organic compound is methane, CH4, in which a carbon atom shares covalent bonds with four hydrogen atoms. The notation "CH4" is the compositional formula.(Id. 132)
There are a number of naturally found organic compounds that do not come from anything alive today. Items like coal and oil are examples. They count as organic because they were formed by the decomposition of plants that lived millions of years ago. There are numerous carbonic compounds that have proved very useful. Some natural ones are oil, plastic, rubber, paper, wood, and petroleum.
Many of the organic compounds worked on today have been created in the laboratory rather than found in nature. Carbon compounds that are considered inorganic are carbon oxides, carbonates, and cyanides.(Donald Gregg, "Organic Chemistry," New Book 129, 131.) There are many synthetic ones produced by industry such as the fibers polyester and nylon that in some ways improve on natural ones.(Id. 131) All in all, chemists have discovered or synthesized over ten million compounds composed of carbon, hydrogen, oxygen, and nitrogen with an estimated 100,000 new ones being found or made in laboratories every year.(Bettelheim 252)
Biochemistry has much in common with organic chemistry. It studies compounds and related processes found in living organisms, while organic chemistry looks at compounds containing carbon. The more recent field of molecular biology overlaps with biochemistry in studying many of the same processes.
There is an interesting story on how organic chemistry got its start. In the early 1800's, one of the most respected chemists around was the Swede Joens Jakob Berzelius. His academic degree was actually that of medical doctor. While he discovered several elements, he did not work on organic compounds, expressing the opinion that humans would never be able to prepare an organic compound because living things contained some "vital force."
In 1828, the young German chemist Friedrich Woehler heated ammonium cyanate and produced the organic compound urea, which is found in urine. In the ensuing years, chemists produced more organic compounds and never looked back. Within a few decades, more organic compounds had been produced than inorganic ones.("Organic Chemistry" 130)
Scientists soon after that stopped placing much stock in a "vital force." The same could not be said for philosophers and the general public as the idea continued to carry weight. In the 1920's, the French philosopher Henri Bergson gained a wide following with his writings about the elan vital (vital force). His prominence has waned, but there are still some who seem sympathetic to the notion of vitalism.
How Life Works
There are close to thirty elements in the human body. There are different numbers of elements for other animals and plants, but elements are important in all. We saw before that these elements were created billions of years ago--the lightest three about 300,000 years after the Big Bang and the rest in stars. These in turn combine to make compounds, sometimes complex ones, with long chains of atoms mainly carbon, oxygen, and hydrogen. However, in living bodies, these materials are not just simply piled up to perform different functions. They are used in the basic building block of bodies--the cell. There are many one-celled organisms like bacteria, and then there is the human body that contains about 10 trillion cells.(Hazen 213) Most cells are about one ten-thousandth of an inch wide with bacteria being much smaller.
Cells have two primary functions: (1) as locations where the complex chemical reactions take place that make the body function and (2) as copiers of themselves. Cells have walls called membranes. There is an outer membrane separating a cell from the other cells, and there are inner membranes partitioning different production areas called organelles.(Id. 216) Not all membranes are exactly the same. A typical one is a double layer of lipid molecules with water-repelling ends head-to-head on the inside and water-absorbing ends on the outside.
Interspersed on a cell's outer membrane are receptors that interact with only one type of molecule on the outside. These receptors are three-dimensional and made of large protein and carbohydrate molecules. Whenever one of these receptors senses the type of molecule with which it is supposed to interact, it binds the molecule and sucks it into the cell. A tiny membrane, a vesicle, then transports the molecule around the cell so that it can be used. A vesicle also transports material after it is no longer needed and forces it through the cell's outer membrane. Thousands of vesicles dart around the cell following the paths provided by fine filaments.
Each organelle has a specific chemical function. It can produce needed proteins to the cell, serve as a platform for protein assembly, provide energy, or digest food molecules. Each organelle has its set of receptors.(Id. 217) The nucleus of a cell is like a command center. It houses the material that directs the operation of the cell.
Every cell needs energy and has tiny sausage-like mitochondria to generate it. Partially digested foods such as carbohydrates are burned in the mitochondria that act like furnaces. There are hundreds of them in a typical cell.(Id. 218) The energy that is not used immediately is transported to other places where it may be needed. Almost all cells use adenosine triphosphate (ATP) to transport small amounts of energy. Cells need larger molecules to move large amounts. The cell has to perform many functions and has thousands of parts to carry it all out.
Plant cells have significant differences from animal cells including a hard cellulose structure. They also have a different process for producing energy. Plants use a complicated chemical process called photosynthesis. Molecules of chlorophyll or related pigments in the plant absorb photons from the sun and convert the photon energy into chemical energy. Carbon dioxide is absorbed from the air as well as water from precipitation or the surroundings. These are converted into glucose or other carbohydrates. Oxygen is expelled into the air as a waste product.
Animals come along and breathe this oxygen waste, which they must have to survive. Where do the animals get their fuel? They can get it only from plants--either directly or indirectly. They get it indirectly from eating other animals who have eaten plants. Ultimately, all animal food has to come from plants. If all the plants disappeared, there are not enough animals around to provide food for very long. Animals burn the fuel they have obtained (in the mitochondria of their cells) and exhale carbon dioxide as a waste product. This animal process of burning fuel by using oxygen with carbon dioxide as a waste product is known as respiration. The two processes of photosynthesis and respiration are a complementary cycle.
The nucleus of the cell can be thought of as the command center because it contains deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), large molecules that instruct the cells what functions to carry out and in what order. Each is built from strings of molecules called nucleotides, which themselves are constructed from smaller molecules. There are trillions of nucleotides in the human body.(Id. 227) DNA carries the genetic code that is present in every cell of every living thing. The genetic code instructs cells to form a rabbit or a bacterium or a human or to form kidney cells or finger nails. It also tells the cells to form and continue renovating the same living thing. It instructs the cells in your body to continue renewing the same individual that you are, distinct from other human beings. It does all this by directing which amino acids are to be built and how. The amino acids in turn make up the proteins necessary for each part of a body.
A DNA nucleotide is composed of three different molecules: (1) a phosphate group, (2) a sugar, and (3) a base. The phosphate group molecule consists of one phosphorus atom surrounded by four oxygen atoms. The sugar is deoxyribose. In the RNA the sugar is ribose. The base molecule is one of four possibilities: adenine, cytosine, guanine, or thymine. They are similar in size but different in shape.(Id. 228) The DNA nucleotide makes an L-shape with the phosphate group and the sugar in a line and the base molecule sticking out perpendicular to the line.
To picture what DNA looks like, start with numerous of these L-shaped nucleotides lined up on top of each other. The bases would be sticking out on one side. Take another chain of nucleotides just like the first and line up the bases opposite to each other and attach them. You have what looks like a ladder with the legs of the ladder made of the two columns of phosphate and sugar molecules stacked on top of each other and the two adjoining bases forming the rungs. You then twist the ladder vertically until it completely acquires a spiral shape. RNA differs in a few ways from DNA including that it is only a half ladder. It is made of only one phosphate-sugar leg and the bases sticking out. The exact language of the instructions of DNA is written in the different combinations of the bases of the nucleotides. There are 6 feet (2 meters) of DNA in each human cell nucleus, which is 5 micrometers long. (modencode. sciencemag.org/chromatin/introduction)
RNA executes the instructions of the DNA. There are two types of RNA: messenger RNA (mRNA) and transfer RNA (tRNA). Messenger RNA delivers the instructions to the cell where the task is to be carried out. From there, tRNA lines up the amino acids in the proper sequence required by the instructions.
The DNA is very well protected; a good thing since it contains very important information. It is inside a cell and then inside the nucleus of the cell away from the cell walls. DNA comes in a long strand wrapped around several small spools made of protein. The strand and the spools together are called a chromosome. Different species have different amounts of chromosomes. Humans with 46 beat mosquitoes that only have 6, but lest you get too proud, goldfish have 94.(Id. 235)
Only about 5% of the DNA in your body is actually taken up by genes.(Id. 240) Gene is the name given a long time ago to what delivers the instructions to cells. It turns out genes are actually a specific segment of a much longer DNA molecule.(Id. 234) There are about 90,000 genes in the human body.
Cells reproduce in two ways. Mitosis is the reproduction of cells from a single cell. This is necessary for a plant to grow or for a cut to heal. Meiosis takes place only in reproductive cells. It is called reproduction but is actually the new production of an individual from two parents with each parent contributing half of the genes that go to make up the new individual. Mitosis is actually more accurately called reproduction since exact copies of the original cell are made, unlike in meiosis. There a new individual is produced with a mix of traits taken from the two parents.
History of the Inhabitants of Earth
What do scientists know about how living things developed in this world? What can looking at that history tell us? Is there consistency between the structure of plants and animals and the scientific estimate of how they developed?
The geologists have studied the earth and estimated that it is 4.6 billion (4,600 million) years old, and the astronomers have found that to be consistent with their investigations of the universe. The world was totally inhospitable to life for the first billion years, and complex life that was even near to how we know it today did not appear until the earth was 4 billion years old or around 600 million years ago (mya).
In the beginning, volcanic eruptions, lightning storms, and meteor strikes were very common. There was no oxygen. The thin atmosphere was mostly hydrogen, ammonia, methane, and water vapor. This was no shield to the ultraviolet radiation coming from the sun inimical to advanced life.("Primordial Soup," The Way Nature Works 90.) However, oceans existed that contained all the elements needed to produce the type of life known today. For a long time it was puzzling how this ambience could allow the raw materials of life to take form.
In 1953 Stanley Miller and Harold Urey at the University of Chicago mixed hot water vapor with hydrogen and ammonia in a laboratory flask and subjected the mixture to frequent electrical charges to simulate lightning. Within a few days, the liquid turned brown and when tested was discovered to contain amino acids. Later experiments used other combinations of gases or ultraviolet radiation and always came up with amino acids, sugars, nucleic acids, and other molecules necessary for life. More recent laboratory experiments have shown there is no problem with producing complex molecules in conditions of the primitive atmosphere and oceans.(Hazen 246)
There is still an important gap in the knowledge of how early life-related molecules (the primordial soup) could produce actual living organisms. The first living things would have most probably been single cells. There are a number of theories, but more evidence is needed to decide which is correct. There is a belief that there could have been numerous amino acids in the ocean's upper layers that could have linked to make the first proteins. Sugars and bases could have joined to make primitive DNA. Lipid molecules could have stuck together until they formed spherical membranes. One theory has it that these fatty membranes were formed first and the fusion of other parts then took place inside them.(Id. 247)
In whatever way they were formed, the first organisms were prokaryotes, another name given by biologists to bacteria. They originated about 3.8 billion (3,800 million) years ago. Their fossils date back to 3.5 billion years ago. They appeared when the earth was 800 million years old. These are very simple cells without a nucleus that reproduce by division or budding and contain no organelles.(Ernst Mayr, What Evolution Is (New York, New York: Basic Books, 2001) 47.) There are different kinds of bacteria, and they were the only life on earth for one billion years.
Biologists believe that at the end of those one billion years one bacteria swallowed another (perhaps of a different kind). That created a more complex cell with a double membrane.(Hazen 215) The new cell was the eukaryote meaning "true nucleus." Its creation may have been the most important event in the history of life on earth.(Id.) It made a later more complex organism possible with its cell nucleus, sexual reproduction, meiosis, and other advanced properties. All of these characteristics were not acquired immediately but sequentially over a long period of time. Some unicellular eukaryotes are the amoebas and most algae.
The entry of the eukaryotes did not mean that the prokaryotes were pushed out. If anything they may have become more abundant due to their status as scavengers and parasites. Today, some calculations estimate the total biomass of earth's bacteria (the prokaryotes) is equal to the total of that of all eukaryotes.(Id.) Eukaryotes include the plant and animal kingdoms, which include us humans.
What is known about the history of life depends greatly upon the fossil record. A fossil is an imprint on rock of an animal that died and was buried suddenly (1) without decomposition, (2) without destruction by scavengers, and (3) with a hard surface capable of leaving the imprint. There have been thousands of fossils found deposited throughout the millions of years of existence of living things. Almost 250,000 fossil species have been identified. About 1.75 million living species have been formally identified, but it is estimated that another 10 million have existed.(Frank Garcia and Donald Miller, Discovering Fossils (Mechanicsburg, Pennsylvania: Stackpole Books, 1998.)
The more recent the time period, the more fossils found. Fossils can often be seen when hiking in mountains or forests. They are not hard to find if one is vigilant. Numerous fossils have been found for certain animals and their ancestors. The horse is an example. Note that it is a more recent animal. Naturalists are still finding fossils of previously unknown plants and animals. Yet in spite of the many fossils that have been left behind, there are still many gaps in the picture of the past because fossils are not easily recorded in the ground. The necessary conditions rarely occur. The time before the appearance of hard-bodied animals left very few fossils. Biologists believe there had to be many animals of the time but their soft bodies left very rare traces.("Primordial Soup," 91) The complex living beings that first appeared 600 mya were only found in the oceans. It was much later that life moved to the land.
Here is a simplified timetable of how life progressed on earth intended to give an idea of relative time periods on earth.
Entry of Organisms
Time of Entry ................................ Organism
(millions of years ago)
4,600 ..................................... formation of earth
3,500 ..................................... prokaryotes (bacteria)
2,700 ..................................... multicellular organisms
600 ........................................ spined animals
550 ........................................ shelled organisms
430 ........................................ fish
410 ........................................ land plants
400 ........................................ insects
360 ........................................ amphibians
340 ........................................ reptiles
220 ........................................ dinosaurs
206 ........................................ mammals
150 ........................................ birds
65 ....................................... extinction of dinosaurs
55 ....................................... horses
25 ....................................... apes
.25 (250,000 years) .............. humans (homo sapiens).(Mayr 20.)
David Attenborough gave a good way to gauge the relation of these times to each other in the following:
Such vast periods of time baffle the imagination, but we can form some idea of the relative duration of the major phases of the history of life if we compare the entire span, from the first beginnings until today, with one year. Since we are unlikely yet to have discovered the oldest fossils of all, we can reckon that life started well before 3000 million years ago and as a rough guide, it will serve to let one day represent ten million years. On such a calendar . . . . . algae-like organisms . . . . . are seen to be quite latecomers in the history of life, not appearing until the second week of August. In the Grand Canyon, the oldest worm trails were burrowed through the mud in the second week of November and the first fish appeared in the limestone seas a week later. The little lizard will have scuttled across the beach during the middle of December and man did not appear until the evening of 31 December.(David Attenborough, Life on Earth: A Natural History (Boston, Massachusetts: Little, Brown and Company, 1979) 20.)
The First Animals
650 mya the oxygen in the atmosphere had reached about 17% of what it is today. This enabled the first animals and plants to later appear. Still the first ones lived in shallow areas of the ocean near shores where the sun's rays penetrated. The first animals probably appeared not long after 600 mya. They have been named ediacarans. They were soft-headed and are possible relatives of jellyfish and worms. There were about 100 species of them, and they could grow to six feet long.
Later there was a great increase in animal diversification, which biologists labeled the Cambrian explosion. The Cambrian period lasted about 50 million years from around 543 mya to 495 mya, so in one sense it was a very slow and gradual explosion. In another sense, it could be called an explosion because comparatively nothing had gone on for the preceding 4,000 million years. All these animals and contemporary plants were still underwater. It would be several million years before the first living things would go on land. They were mats of algae, lichens, and bacteria that only stayed on the edge of shallow pools.
By 530 mya, a wide variety of sea animals with hard mineralized shells and spines were on the scene. This marked the beginning of an "evolutionary arms race."(Robert Hazen, The Story of Earth (Penguin Books, 2012) 237.) This means that there arose a predation system among animals in which certain of them, the predators, kill and eat others for their sustenance, the prey. It is in very wide practice to this day. These early animals grew progressively larger in order to fight more successfully. They gained new armor in teeth and claws. Their hard shells and sharp spines were designed for sound defense. About 520 million (.5 billion) years ago, all the major subdivisions of the animal kingdom were in existence.
The first fossils of what are counted by earth scientists as actual plants were found in rocks 475 mya. They were not what we normally think of as plants. Instead, they were microscopic plant spores. They were probably similar to liverworts descended from green algae that only lived in low, wet places.(Id. 242) Evolution would not bring about leaves for tens of millions of years. Plants slowly left exclusively wet areas and spread to barren lands. Actual fossils of the bodies of plants of the time have not been found. This is not surprising since they were likely small, delicate, and decayed readily. Around 410 mya, larger, visible plants went on land, followed by the first air-breathing animals, millipede-like arthropods. Arthropods are a group of invertebrates possessing legs with joints and segmented bodies.
By 360 mya, forests appeared in swampy areas. For the first time, the color green could be observed. Plants and trees with their unique biochemical systems came to affect the mineralogical makeup of the soil and rock they inhabited. In turn, the latter helped determine the nature of the plants that appeared--all in a symbiotic relationship.
It was a slow transition for animals to make it onto the land from the water. A few fish developed primitive lungs for utilizing air, but it would be millions of years before there would any amphibians representing an intermediate stage. The first creatures to make a home on land were invertebrates, meaning without a spine. They were small, for example insects, spiders, and worms. Fish were the first animals to develop backbones. Fossil bones from 375 mya reveal the earliest four-legged land animal, a walking fish with finlike feet. One line of fish developed a bony skeleton, air-breathing lungs, and limbs strong enough to walk on land. It was not until 340 mya that the first true amphibians appeared--clearly distinct from fish.
Gradual increase in the percentage of oxygen helped bring about the proliferation of diverse healthy plant and animal species. 380 mya the atmosphere was about 18% oxygen, 350 mya it was at 25%, and 300 mya up to at least 30%. Today it is at 21%. It is possible that it got close to 35% at one point. This bode well for the health of animals and enabled some of them to grow to megasizes. For instance, dragonflies came to have two foot wingspans. Cockroaches came into being 325 mya and have been one of the few genera to survive to now. Supposedly, they can live by eating almost anything-an explanation why it's hard to keep them out of your house. For tens of millions of years, life was good for hundreds of thousands of wide-ranging species enjoying the aid of a favorable climate and plentiful resources as had never been seen before. Still, there were tough times. Climate could cause great destruction.
One of the lines of fish evolved into the reptiles that were able to extend themselves to every available habitat and adapted into different forms. Some took to flight like the pterodactyls and archaeopteryx. Others returned to rule the waters, for example plesiosaurus and ichthyosaurus.("Rulers of the Earth," The Way Nature Works 92.) Then there were the dinosaurs. The time period from 250 mya to 65 mya has been called the Age of Reptiles. Officially, it is called the Mesozoic Era. Dinosaurs are classified as reptiles. Small mammals appeared during this time but remained inconspicuous and were able to survive the presence of the dinosaurs. Perhaps this was good training for them for the future.
A wide-ranging extinction of animals (perhaps some microbes, too) occurred 444 mya. That was the first of numerous mass extinctions, which will be discussed more fully in a chapter on the design of the world in Book 3. The Age of Reptiles came to an end when the dinosaurs and many other species became extinct in relatively quick fashion as mostly the result of the impact of a giant meteorite in the Yucatan Peninsula that sent plumes of dust into the atmosphere that blocked sunlight for years. This extinction is perhaps the one best known to the public. One occurred 250 mya, right before the beginning of the Age of Reptiles, in which it is estimated that about 96% of all marine life became extinct. There have also been numerous gradual extinctions. The other big ones each killed between 80 and 85% of existing species.(Mayr 202) It is thought in the biology community that "99.99 percent of all evolutionary lines have become extinct."(Id. 140) Life on this planet has been very fragile.
Rise of the Mammals
With the dinosaurs out of the way, mammals had more freedom to flourish. Contemporaneously, flowers and trees also proliferated. Eventually, forests and vast grasslands appeared to house the growing species of mammals that spread all over the world. The flora and fauna began to look more like they do today. Early primates started using trees and developed precise control of their hands and feet and an enlarged brain. One of their line evolved into the apes.("The Warm-blooded World," The Way Nature Works 94.) Primates also include prosimians, lemurs, and monkeys.(Mayr 234) Some forms of mammals like the ancestors of the elephants and rhinoceroses developed into large forms, i.e. the woolly mammoth, and later became extinct.
Do humans fit into any of this? Is there any evidence of humans in the fossil record or any other source of information? Or is there a wide gap in the fossil record or any other type of evidence that would show humans as a special creation? Ernst Mayr, who has been called the "sage of 20th century biology," had this to say:
No well-informed person any longer questions the descent of man from primates and more specifically from apes. The evidence for this conclusion is simply too overwhelming . . . (Id. 235)
Mayr pointed to three types of evidence to support this. Humans are like apes, particularly chimpanzees, in all anatomical details except for a few strictly human characteristics like the proportion of arms to legs, the mobility of the thumb, body hair, and the size of the brain. Secondly, there are numerous fossils showing intermediate and later stages in the transition from a chimpanzee-like ancestor to humans. Humans did not evolve directly from chimpanzees although it is often talked as if they did. Then there is evidence that has been recently developed in molecular biology. The macromolecules in African apes are more similar to humans than to those found in any other primate. Certain enzymes and proteins in chimpanzees are virtually identical to those of humans; others differ only slightly. Chimpanzees are more different from monkeys than they are from humans.
About 8 million years ago, chimpanzees lived in the trees of rainforests of Africa. They ate leaves, stems, and soft fruits and had a small brain. They used tools, as has been discovered is also the case for other mammals.
After that, a line of chimpanzee-like apes established posts in the tree areas surrounding the rainforests. They were not much different from the chimpanzees except that they became bipedal and developed harder and longer teeth to deal with the tougher vegetation they had available. They could live in calm since there were no predators around like lions and wild dogs and, in any case, they could resort to climbing trees in order to escape. It is a reasonable inference that they also used tools although no relics have been found. They appeared to be peaceful vegetarians.(Id. 243) These apes are called australopithecines and are now extinct.
The trees started to disappear about 2.5 mya because of a definite climate change correlated with the beginning of an ice age in the northern hemisphere. As the climate became more arid, there were fewer and fewer trees to which the australopithecines could retreat in the face of lions, hyenas, and wild dogs who could outrun them. They had to become creative in defending themselves. There is much room here for speculation. They could have used long poles like chimpanzees do in western Africa or swung thorny branches. They may well have been the first apes to ignite and use fire even to the extent of using it as a barrier surrounding them at night. They were the first apes to use flaked stone tools, perhaps even making lances.(Id. 245) This line of australopithecines was gradually turning into the genus Homo.
"This shift was the most fundamental one in all of hominid history," Mayr said. (Id.) Brain size became dramatically larger while teeth became smaller. Teeth could become smaller because of change in diet. Early Homo probably used fire to cook plants and animals that it now started to hunt. Homo had turned into an aggressive carnivore.
All of this narrative on the development of Homo is subject to change depending on future findings, especially fossils of australopithecus and Homo. Two species, Homo rudolfensis and Homo erectus, appeared in eastern Africa, but they may have migrated from northwestern and southern Africa. Homo erectus was very successful and was the first hominid to emigrate from Africa.(Id. 247) He went to Asia and Europe where there is a rich fossil record of his transition through Homo heidelbergensis to Neanderthal.
In Africa, Homo erectus evolved into Homo sapiens (modern humans) who later spread rapidly to diverse parts of the world including Australia. About 100,000 ya, H. sapiens spread over areas inhabited by Neanderthal. The group of H. sapiens that reached western Europe about 35,000 ya is called Cro-Magnon. About five thousand years later, Neanderthal disappeared. It is not clear what caused this demise. It could have been climate or disease that didn't affect Cro-Magnon or inadequacy in meeting challenges or it has been asked whether it was the victim of genocide by Cro-Magnon.(Id. 250)
Similarities
The physical basis of all living things is widely evident as is their similarity to each other in the way they are constructed. There is first the connection of living things to the early inanimate universe in that the elements that are found in them were made at that time, mostly during the formation of stars. Those elements make up constituents of living bodies such as proteins, carbohydrates, nucleic acids, and vitamins. They are found in all living bodies but in different amounts. Animals eat food that has the same or similar constituents that are consequently found in their bodies. Certainly animals have a great dependence on plants. The structure and function of all cells is very similar. There is a gradual, continuing, and cohesive history for the development of living things.
For the purposes here, it has not been necessary to go deeply into evolution. It is very clear that living things have great similarities especially if they are in similar classes like the sea plants or primates regardless of whether evolution ever took place. The latest detractors of evolution claim that intelligent design has to explain the complexity of living things. According to them, evolution could not be responsible for the complicated construction of living things especially the human; there had to be an intelligent designer. If they are correct, it would seem that the intelligent designer often used designs of earlier living things as models for the new ones he constructed. A good example is the human with so many similarities to the chimpanzee. The human is simply a new and improved model of the chimpanzee after the intermediary step of the now extinct australopithecine.
The brain is not the mysterious receptacle that it was once thought to be. It is not impossible to understand. While there is still much to learn about the brain, much progress has been made in the last hundred years and continues everyday. Continuing advancements in the technical instruments that help in examination of the brain make the study easier.
This chapter will go over the function of nerve cells, what the different areas of the brain apparently control, and how neuroscientists have been able to observe those different areas in action. All animals have nerve cells and nervous systems. Those of mammals have great similarities to each other. This is the reason neuroscientists have been able to perform experiments on the brains of rats and monkeys and draw inferences from those findings to the workings of human brains.
Neurons
Nerve cells, also called neurons, are like the other cells of the body in their basic protein and fat composition and in the way they receive their nourishment and discard waste. They are in charge of transmitting information through the brain and nervous system. They do not have the cubelike shape of most cells but rather look more like a tree with the dendrites representing the branches, the cell body serving as the top of the trunk, the axon being a long trunk, and the terminal fibers of the axon serving as the roots. Dendrite comes from the Greek word dendron for tree.
The dendrites are the various branch-like fibers that receive stimuli from adjacent neurons while the cell body contains the cell nucleus and the other parts normally found in a regular cell. The stimulus is felt as a change in the electric potential called the action potential. The electrical stimulus passes to other neurons or to muscles and organs out of branch-like terminal fibers at the end of the axon. These fibers are intertwined with the dendrites of many other neurons. You can also think of the electrical impulse as an electric current. Surrounding the axon fiber of some neurons is a layer of fat cells called a myelin sheath that helps speed the impulse.
An electrical intensity greater than the action potential necessary to produce a stimulus would not aid the transmission of the impulse in any way. The neuron acts like a switch; it either "fires" producing an impulse or it doesn't. Nor would a heightened intensity speed up matters any. Depending on the type of fiber, the impulse travels from 2 to 200 miles per hour.(David Myers, Psychology 3rd ed. (New York, New York: Worth Publishers, 1992) 29.) This is much slower than a computer, which unfortunately is the reason we sometimes respond to an emergency much more slowly than we would like. The way the intensity of a stimulus is transmitted is by causing more neurons to fire or for them to fire more often.
There are three types of neurons in the nervous system. There are sensory, or afferent, neurons that send electrical impulses from the body's tissues and organs inward to the spinal cord and brain. The spinal cord and brain process information through the use of interneurons. Any instructions the spinal cord or the brain need to send to the other parts of the body are sent through motor, or efferent, neurons.
An interesting illustration of neural pathways at work involves the simple pain reflex. If you touch a flame, sensory neurons will send a signal to the spinal cord, which processes the information through its interneurons. The spinal cord quickly decides that you should move your hand away from the fire and sends a signal to your hand through motor neurons. The spinal cord then sends the information that you have touched a flame to the brain, which then realizes what has happened. The brain, however, is not involved in the decision to move your hand. The spinal cord can take care of that by itself. For simple reflexes, it doesn't need the brain to decide what to do. It just reacts. All the sensory and motor neurons involved are part of the somatic nervous system.
The Nervous System
The nervous system of the human body is divided into two subsystems, the central nervous system and the peripheral nervous system, which are in turn further divided into other subsystems. The central nervous system consists of all the neurons in the brain and spinal cord. They are linked to the body's sense receptors, muscles, and glands via the peripheral nervous system.
The central nervous system does not have any subsystems while the peripheral has two, the somatic and the autonomic nervous system. The former includes all the sensory and motor neurons and is thought of as voluntary because it involves control of voluntary movements of our muscles. The autonomic nervous system involves the glands and the functioning of internal organs. It influences such operations as heartbeat and digestion. This system is further broken down into the (1) sympathetic nervous system that arouses the body for necessary action, as when there is a threat. It facilitates processes like accelerating the heartbeat and raising blood sugar to prepare us for action. After the threat is over, the (2) parasympathetic nervous system calms us down by slowing the heartbeat, lowering blood sugar, and halting perspiration.
The Triune Human Brain
The human brain is organized into three separate regions that seem to have been formed in accordance with evolutionary development. This "triune" brain was proposed by Paul Maclean in the mid-twentieth century.(Steven Johnson, Mind Wide Open (New York, New York: Scribner, 2004) 204.)
The first and most primitive part is at the bottom: the brain stem. It is also called the "old brain" or "central core."(Myers 37) It sits atop the spinal cord with a part called the medulla, which controls heartbeat and breathing. This is also the location of the crossover of nerves which connect the left brain with the right side of the body and the right brain with the left side of the body. The reticular formation is a network of neurons located in the brainstem and helps control arousal and attention. It connects to the thalamus situated above the brainstem. It is the brain's sensory switchboard routing neuronal impulses to the appropriate parts of the brain that deal with sight, hearing, taste, and touch.
The limbic system (limbus means border in Latin) is somewhere between the brainstem system and the cerebral part. There is disagreement among neuroscientists on whether it is a truly unified system. It is comprised of the amygdala, hippocampus, and hypothalamus and is involved with emotions, motivation, and memory. Take out some of the cells (called lesioning) in the amygdala of a rhesus monkey that is normally ill-tempered, and it will become very placid even if you poke and pinch it. Similar results can be obtained with wild animals like wolverines and rats. Also, similar results can be obtained with aggressive human criminals, but for ethical reasons, this has not been practiced because of other drastic changes in the person.
The more complex animals like cats and monkeys have a cerebral cortex that gives them greater intelligence and adaptability. One area in the cortex is known as the sensory cortex. Incoming sensory messages from different parts of the body are received here. A specific spot in the sensory cortex will feel each individual sensation coming from its corresponding place in the body.
Neurosurgeons discovered this by pricking specific areas in the sensory cortex. Neuroscientists have identified spots on the sensory cortex that correspond to parts of the body as specific as the upper lip, the lower lip, the little finger, the ring finger, the pharynx, as well as all the larger parts like the hip, the foot, and the leg.(Henry L. Roediger III et al., Psychology, 2nd ed. (Boston: Little, Brown, 1987) 57.) The brain can be pressed with a hard object without producing any pain to it because it itself has no sensory receptors. Sensations do not just involve one point on the sensory cortex but can involve several parts of the brain. Say you look at a photograph with a caption underneath it. The bare visual image will first be received in the occipital lobe at the back of the brain, but it needs to be interpreted. The sensation that identifies the image goes to other parts of the brain such as those for recognizing faces, discerning emotions, and reading words.
The motor cortex is located next to the sensory cortex and is in charge of making different muscles move. Stimulate a specified point in the motor cortex and a specific muscle or set of muscles will react, for instance, a leg will twitch. Neuroscientist Jose Delgado stimulated a point in the left motor cortex to make a patient's right hand make a fist while asking the man to resist the force and keep his fingers extended. The patient's fingers closed despite his best efforts. He remarked, "I guess, Doctor, that your electricity is stronger than my will."(Jose Delgado, Physical Control of the Mind: Toward a Psychocivilized Society (New York, New York: Harper & Row, 1969) 114.) This and similar examples bring up serious questions about the existence of free will.
The remaining part of the cerebral cortex, aside from the sensory and motor cortexes, is known as the association areas and makes up about three-quarters of the cerebral cortex. It does not respond to electrical stimulation like the sensory and motor areas. Neurons here communicate with each other and with neurons in the sensory and motor areas.
Association areas perform a variety of mental functions. An area in the right temporal lobe aids in the recognition of faces. If that spot is injured, you would not be able to recognize your next-door neighbor, maybe not even your spouse, but you would be able to look at a face and describe its features, age, and gender. This is because complex mental functions like learning and memory involve more than one area. This is very helpful because it allows the retention of abilities even if one area of the brain affecting a related ability is damaged. Language is another ability that involves different parts of the cortex. Association areas in the frontal lobe facilitate judging and planning. The large frontal lobe of humans distinguishes them from other animals with a frontal lobe. Persons with damage to this area can retain all their memories and maintain their previous level of intelligence but not be able to plan a simple shopping trip.
Damage to the frontal lobe can bring permanent, dramatic personality change, as in the case of American railroad worker Phineas Gage. One afternoon in 1848, he was at work and an accidental gunpowder explosion blew a tamping iron into his upper jaw and out the top of his skull. The 25-year-old survived and returned to work--for a time. Amazingly, he could still talk and retained all his mental abilities and memories. However, his personality changed dramatically. Before the accident, Gage had been friendly and soft-spoken, but afterwards he was irritable and capricious. He lost his job and had to work at a fairground exhibit. His friends said he was a different man.(Myers 45) Personality changes like this call into question the idea of the soul since it has been taken as something that is permanent and constant in each person, not subject to physical alteration. People say things like he is a "steady soul" meaning he has a constant, enduring character.
The triune brain has been considered from an evolutionary perspective. From that point of view, the brain stem is also called the reptilian brain. It is pretty much what is found in reptiles--providing coordination of bodily functions and basic instincts but incapable of complex emotions. The limbic system is known as the paleo-mammalian brain and is shared by most mammals. Humans are more likely to have dogs and cats as pets rather than snakes and lizards because their greater emotional repertoire that can be better appreciated. Third, the cerebral cortex is also known as the neocortex.(Johnson 205) It is at the top of the brain as if stacked on in later evolutionary epochs. Rats and other mammals have a very small cerebral cortex, primates like cats and monkeys have a substantial version, but that of humans is dramatically larger.
Chemical Messengers
Electric current flows out of the fibers at the end of an axon to carry a message to the next neuron, yet the two neurons do not touch. Between the two neurons, there is a very slight gap filled with fluid called the synapse. The terminal fibers at the end of the axon of the transferring neuron are called the presynaptic site; the area containing the receptors on the dendrite of the receiving neuron is called the postsynaptic site.
In the presynaptic site, there are vesicles that store neurotransmitters, chemical compounds that help carry the message.(Frederick Bettelheim, William Brown, and Jerry March, Introduction to General, Organic & Biochemistry 6th ed. (Fort Worth, Texas: Harcourt College Publishers, 2001) 547.) Each neuron transmits only one kind of neurotransmitter. When the electrical impulse arrives from the axon, the neurotransmitter leaves the vesicles, crosses the synapse in 1/10,000th of a second, and binds to receptors on the surface of the postsynaptic site. The binding of the neurotransmitter to the receptors allows ions to either enable or inhibit the receiving neuron from carrying an electrical impulse forward.(Myers 30)
After this takes place, the neurotransmitter molecules must be removed from the receptors. Accordingly, enzymes are assigned to dispose of specific neurotransmitters. For instance in the case of acetylcholine, the enzyme acetylcholinesterase is assigned the clean up.
There are a number of neurotransmitters, some of which are acetylcholine, norepinephrine, dopamine, serotonin, histamine, and glutamic acid. Some neurotransmitters are amino acids. There is much to learn about neurotransmitters and their actions and interactions with each other and with drugs. Each neurotransmitter is assigned a different function or functions. Different externally ingested drugs can enhance or inhibit their actions.
Acetylcholine acts primarily on motor nerves causing skeletal muscles to contract. It is an excitatory neurotransmitter so if you introduce a substance into the body that blocks its release, it can have paralyzing consequences. Botulinum, which comes from contaminated food, is an example of a chemical that can go so far as to cause death. Curare, the drug put by South American Indians into their darts, stops the victim from being able to breath. On the other hand, the black widow spider's venom increases the release of acetylcholine causing muscle spasms.
Serotonin is a neurotransmitter that contributes to a sense of well being and pleasure. The well-known psychiatric drug fluoxetin (Prozac) is one of a number of selective serotonin reuptake inhibitors (SSRI's) slowing down the clean up (reuptake) of the serotonin in the postsynaptic site as mentioned above and thereby relieving depression. It seems that part of the problem with people who suffer depression may be insufficient production of serotonin. Visual exposure to sunlight during the day can help the body increase its serotonin level.
Endorphins are opiates produced by the body in response to pain. They act similarly to morphine, which is why their name comes from "endogenous morphine." The first endorphin was discovered in 1975.(Hughes, J., Smith, T.W., Kosterlitz, H.W., Fothergill, L.A., Morgan, B.A., & Morris, H.R., "Identification of Two Related Pentapeptides From the Brain With Potent Opiate Agonist Activity," 258 Nature 577-579 (1975).)
Hormones are another type of compound produced by the body that aid in various processes. Some of the better known hormones are insulin, thyroxine, oxytocin, cortisol, progesterone, and testosterone. They are secreted by glands in the endocrine system such as the hypothalamus, pituitary, and the adrenals situated on top of the kidneys. Hormones differ from neurotransmitters only in that they act at greater distances from the source of secretion. Neurotransmitters act across the tiny width of a synapse, while hormones can travel 20 centimeters from the secretory gland through the bloodstream to the target cell.(Bettelheim 548) Epinephrine and norepinephrine are either neurotransmitters or hormones depending on the distance they have to act. Vitamins and minerals aid the work of hormones. Iodine, for instance, is necessary for the thyroid to carry out its hormone production.
Brain Analysis
The oldest way of observing the brain through technical instruments is with the electroencephalograph. Before that, the only way to explore the brain was to surgically perform a lesion (removal of cells) on an area of the brain to see what effect it would have. For instance, it was discovered that performing a particular lesion on a rat would eliminate its appetite to the point that it would have to be force-fed. Alternatively, doing the lesion in a different nearby area would cause gluttony.
The electroencephalograph was invented in 1929. It uses probes much like those used in an electricity measuring ammeter. The probes are attached to the head to pick up electrical activity. In the beginning, the electroencephalograph could only provide a picture of the electrical activity of the entire brain. For instance, it could inform, by the type of wave detected and displayed on a screen, whether the subject was excited, resting, asleep, or in a coma. This had limited usefulness. With the use of computers, it became possible to filter out the part of the brain's activity in which the testers had no interest. A stimulus would be applied repeatedly to the specific spot on the brain that was being examined, and only the electrical waves from that place would be displayed for consideration. Brain damage can be discovered in this manner very quickly.
Brain imaging is a more recent method for investigating brain function. Actually, there are three major methods that have developed that differ in technical procedure. The first is the computerized axial tomograph (CAT) scan first developed in the early 1970's. Tomography is a radiologic technique for taking X-rays. The conventional chest X-ray with which most people are familiar is a static representation of the interior of a person's chest including the lungs. It is adequate for various purposes but not enough for viewing deep internal structures obscured by overlying organs or soft tissues. In linear and multidirectional tomography, the X-ray tube and the film on which the impressions are made are moved in varying directions to get a better representation.
In the CAT scan, the impression is not made on a film but is picked up by a radiation detector and recorded as a pattern of electrical variations. Many sweeps of the X-ray beam are made and recorded at thousands of points by a computer showing a varying brightness on a screen corresponding to the varying density of tissue under scrutiny. Damage to any tissue can be detected, including brain tissue.
The positron emission tomograph (PET) scan makes use of the relatively rare positively charged analog of the electron, the positron. A subject is given a temporarily radioactive form of glucose and given different thinking tasks. The PET scan picks the differing amounts of radioactivity in the brain, which betray which areas of the brain are involved, and to what extent in the performance of different tasks. The level of activity is indicated because the more active the neuron the more glucose it demands and consumes. The PET scan has helped narrow down the different brain areas involved in such activities as singing, working on a crossword puzzle, and daydreaming.
With magnetic resonance imaging (MRI), a good picture of soft tissue can be obtained when a magnetic field aligns the spinning atoms in the tissue. Radio waves then momentarily disrupt this alignment. When the atoms return to their normal spin, electrical pulses are released and displayed by a computer. The varying density of tissue is demonstrated. One brain application is the detection of enlarged, fluid-filled brains of some schizophrenic people.(Myers 35-36) As with the PET scan, the MRI is also capable of displaying brain activity in relation to tasks being performed.(For a personalized description of taking an MRI to analyze brain activity see Chapter 6, "Scan Thyself," Johnson 158.)
Chapter Conclusion
It is clear that the brain is not some impenetrable dark chamber that must remain mysterious--at least in humans--because it houses an elevated component--the soul. The brain has much in common with the rest of the body and can be measured in similar ways. The brain and the nervous system to which it is intimately related operate in harmony through several means.
There is a physical and mechanical organization of the body, with the neuron as the important means of communication and coordination. Sensations felt by the body trigger appropriate responses by certain parts within the body. The spinal cord and the brain bring about mechanical actions through muscle movement. The brain is arranged into various compartments. The primate brain shows evidence of a gradual evolutionary development with the most recent cerebral cortex positioned on top of the earlier areas.
Neurons pass required information by electrical and chemical means. Hormones and other chemical compounds are essential in facilitating certain body functions. Drugs are chemical compounds that can enhance or inhibit the operation of neurotransmitters. It is clear that the brain and nervous system operate by physical means, especially in the way that the neurons are formed, nourished, and broken down. Electricity plays a big part in carrying signals throughout the brain and nervous system. It is no surprise that the phrase "electric brain" was coined. Chemical compounds play a big part, so "chemical brain" would also be appropriate.
One curious observation in the operation of neurons is that it would seem that the chemical communication that has to take place at the synapse through neurotransmitters could have been made to be far more efficient. The chemical involvement certainly slows things down. Communication solely through electrical means would be much faster, just as it is in the circuitry of manmade electrical instruments such as the computer. It would seem that a better design would have been to let neurons touch so they could forego the chemical interactions and transmit information solely through much faster electrical means. A code like the binary code in computers could have been used to provide varying messages instead of the assortment of neurotransmitters. Neurons do not seem to be the product of intelligent design but rather of evolutionary serendipity.