A PHILOSOPHY OF THE FOUR-DIMENSIONAL SPACE-TIME
The Worldview of Relative Simultaneity
CHAPTER III The Problems of Time Representation
1. Reflective Examination of Time
(3) Subjective Time (Temporal Modality and Subjective Specificity)
In this way, the physical universal time unit was established and the objective concept of time was acquired and refined. Meanwhile, however, time and its passage occur in the human mind. Our mind is constantly connected with the passage of time. In the case of space, if you close your eyes and stay still, you can eliminate these spatial dimensions from your awareness (although strictly speaking, unless your whole body is paralyzed, your spatial senses will not go dead). In contrast, this is not the case with time. Even if you can stop breathing for a short period of time, you cannot keep your heart from beating. If you could stop your heart from beating and could stay alive, you could not keep your consciousness from working. Even if you put your hands over your ears, you cannot do anything about the rhythmic music running in your heart. As long as you are aware, time always accompanies your awareness. In addition, your awareness does not need to be clear. Time runs even in your dreams.
With a focus on philosophical history, Aurelius Augustinus (354–430) considered that time occurred within the human mind and Kant regarded time as a form of inner intuition in relation to human internal senses. (However, it seems that Kant did not intend to totally reduce time itself to human spiritual elements.) Henri Louis Bergson (1859–1941) critically examined time in the form of space and highlighted the “pure duration” within the human mind. From Bergson’s perspective, Kant was also a focus of criticism as a thinker who recognized time in the form of space. In addition, the analysis of the concept of time by Edmund Husserl (1859–1938), which was based on phenomenology, also focused on the examination of human internal awareness of time, just as his concept of “retention of the past” demonstrates.
All events that have clock time allocated to them are quickly becoming things of the past and remain just in our memory and records. By the same token, events that are expected to occur in the future always become things of the present over time and subsequently pass into the past. We categorize time into past, present and future. These are called temporal modality.
The interpretation of temporal modality can be ontologically divided into the following three major viewpoints:
(1) Only the present exists (presentism).
Which one of these three viewpoints should be selected is a major issue of discussion in the area of philosophical time theories. Whereas some people argue that the essence of time is the present, which constantly repeats the process of coming into being and vanishing, others claim that the essence of time is the distribution of incidents from the past to the future. I do not intend to examine these three viewpoints in detail. This study is based on the third viewpoint.
(2) The period of time from the past to the present exists (growing block theory).
(3) All the time processes from the past to the future exist (eternalism and block universe theory).
In theory, it is possible to think that the period of time from the present to the future exists, but no one argues that such is the case.
This concept of temporal modality is not involved in the objective concept of time in terms of physics and objective clock time in terms of historical studies. This is because the present cannot be objectively established independently from the speaker’s standpoint. Thus, physical laws are expressed in the form of a function including a time parameter and history is represented in the form of a chronological table. Both involve no present at all and can have an arbitrary point of time as the virtual present. In addition, it is certain that the relativity of simultaneity represented by the theory of relativity has completely collapsed the objective uniqueness of the present in principle.
However, it is also certain that the time presentations of the past, present and future exist in our consciousness. Our awareness can grasp time only on the basis of such presentations.
(3-1) Time Presentations and an Image of Their Flow
People often associate time presentations with the image of flow. I wonder why. The flow of time does not mean that a kind of entity as time physically flows from one place to another. Time cannot be considered something fluid.
The image of time flowing involves the following two situations. First, consider a flowing river. Imagine the situation in which you are looking at water or objects floating on the surface of the river from the riverbank. As time passes by, the sight of the river’s surface constantly changes from upstream to downstream. This situation can overlap with the passage of time. Fallen leaves and driftwood floating on the river’s surface can be compared to various events in the world and the riverside can be compared to your present consciousness. This is one image of time flow. Now imagine a second situation in which you are aboard a small boat floating on the flowing river, looking at the constantly changing landscape of the riverbank and the nearby land. The riverbank scene is constantly changing and never returns to the way it was just a few seconds ago. In this case, the riverbank landscape can be compared to historical events and you, who are aboard the boat, can be compared to your own current consciousness itself.
The first situation with you on the riverbank represents an image of events flowing outside of you and the second with you on the boat represents an image of you flowing in historical events. In either case, these images seem to show that various events you perceive originally existed. In accordance with this reasoning, it is conceivable that people have been familiar with the model of human existing consciousness scanning four-dimensional space-time since early times in human evolution.
If you intend to envisage an image of time from the perspective of constant present creation and disappearance and pure present endurance, an image of a river flowing may be inappropriate. Instead, an image of flow could be compared to that of water springing from a fountain. Water in the fountain represents the present. There exists nothing but it. The past has dribbled away and the future has yet to emerge. The past exists only in human memory and the future is a non-existence in the form of prediction and anticipation.
(3-2) Now as a Pronoun
What is “now” or “the present”? This question poses the biggest mystery in our concept of psychological time. If you seek a spatial concept corresponding to “now,” it would be “here.”
The word here represents a concept that depends on the speaker’s standpoint. There exists no absolute here in the universe. Any place can be here. The arbitrariness is evident.
Before the relativity of simultaneity was accepted, many people had considered “the present” to be the only and absolute thing in the universe. People had recognized that any point of time involved the arbitrariness of having been “now” and of being “now” in the future, but they had not recognized the arbitrariness of equal “now” being able to coexist in multiple forms. In comparison with space, this situation is analogous to people aboard a moving vehicle thinking that a particular spatial point used to be “here” and another point will be “here” in the future. In this case, people suppose that their current vehicle (or their own body) is the only and absolute one and that here is the only and absolute spatial point; they speculate that many other places exist only in their imagination. But with the exception of solipsists, few people have a notion of the only here. However, people have long believed that now is the only and absolute thing, and many still believe that.
Then, what is the critical difference between here and now? In my opinion, the biggest difference is that interactive communication is possible between different spatial points of here, whereas interactive communication is impossible between different temporal points of now. This is the principal reason why people think that now is the only and absolute thing in the universe. What makes it impossible to have interactive communication between different temporal points of now is that, in Minkowski space-time, communication can be conducted in only one direction and its velocity is also limited by the speed of light (at least, in a macro-realm where our consciousness exists). In contrast, in the case of space, all directions are equal, which makes it possible to have interactive communication between different spatial points of here.
In this context, I note that now is a concept similar to that of personal pronouns. Personal pronouns, such as I, you, he, she and they, can represent many people arbitrarily, but their representations differ with the first person, the second person and the third. Third-person expressions, he, she and they, can represent anyone other than the speaker or the listener. In sharp contrast, the first and second persons depend totally on who the speaker and the listener are. In particular, the first-person singular represents a particular speaker and involves no arbitrariness whatever. For the first-person plural (for example, we), the arbitrariness is limited to the groups to which the speaker belongs. For the first-person pronouns, the substitution is based only on the fact that an arbitrary person can be the speaker. In the general case of first-person pronouns, it is impossible to arbitrarily choose a particular person in any consciousness. Who the first-person pronouns represent in each context is predetermined in a self-evident manner.
I want to note the pronoun here again. What it specifically represents is arbitrary. The idea that the representations of here constantly change in the context is established on the assumption that you yourself are moving according to a static criterion such as observations of land passing by you. Probably, there are even a few advocates of the Ptolemaic system who believe that they are always static and that everything else is in motion. Theoretically, it is possible for you to have the worldview that the absolute static criterion of the universe is your right eye. In accordance with this thinking, a quick glance at the right means that the entire universe including your body except for your right eye is turning to the left in a moment. In this worldview, here represents nowhere, but you are looking with your right eye and every scene exists there. That is, here in this context is absolute and involves no arbitrariness for a particular eyeball. The arbitrariness of here is based on the fact that a particular spatial point is here for an arbitrary eyeball. However, in general, with regard to any eyeball, it is impossible to arbitrarily choose a particular eyeball as a criterion. The place representing here is firmly predetermined for any eyeball. Here is quite similar to the first-person pronouns.
Next, I move on to examine “now”. In fact, now is a kind of first-person pronoun, but this concept was not recognized for a long time. This is because many people believed that now is completely a sole concept with no arbitrariness for substitution in particular consciousness. Once the relativity of simultaneity was established, it became clear that every temporal point can be now. In accordance with this reasoning, now can be looked at as a kind of pronoun similar to I and we. It was evident for a long period of time that the scope of the group represented by we was changeable, but it was not clear until the theory of relativity was established that the spatial scope of simultaneity now represented was also changeable. This explains why people took so long to recognize that now and we were quite similar as pronouns.
Presentists would criticize this argument, arguing it is based on the existence of four-dimensional space-time. In fact, the argument is actually based on the existence of four-dimensional space-time. The logic is consistent with what I have argued in this study thus far.
The majority of time theorists share the critical view that the concept of time processed by and comprising scientific knowledge is artificial and that the genuine concept of time is purely duration itself intuitively perceived by the human mind.
Certainly, it does not seem a philosophical attitude to blindly accept the notion of time that is presented by natural science or is unconsciously used in our daily lives and production activities.
However, I cannot avoid being doubtful of the idea that stark duration is something fundamental. I wonder if we can regard that duration as of ontological origin. I also wonder if we can avoid being trapped in solipsism as a result of examining the subject as closely as possible.
Bergson was persistent in criticizing the spatial concept of time, claiming that the true concept of time consisted of pure duration inside human consciousness. He looked upon space as something even and homogeneous and had the critical view that this spatial homogeneity was forcibly applied to time as well. However, his idea that space is even and homogeneous has now become obsolete from the perspectives of the theory of relativity and quantum theory. It would be at most valid to focus on space on the basis of the assumption that it approximately involves homogeneity. Bergson addressed the theory of relativity and argued about it, but it is unclear how much he actually understood the theory.
More than anything else, Bergson intended to highlight heterogeneity between space and time in a radical way. To restore the time representations of specific life and spiritual activities that had been sacrificed to obtain objectivity and universality, he removed the spatial concept of time and considered that pure duration, which could be understood only through intuition without any theoretical analysis, was the true nature of time. In addition, he presented the concept of philosophy of life toward Creative Evolution.
Bergson regarded pure duration as the truly vital time instead of unvital time, but I wonder how well such an ambiguous, unspecified abstract concept could create specific vital life activities. Abstract concepts in natural state as a result of being abstracted are just constructs of imagination and not active on their own. However, focusing only on this aspect ignores what concepts are all about. The real evaluation of the significance of abstract concepts depends on the specific information they contain and how sophisticated that information is condensed so as to be applied to specific things. The real evaluation also depends on the wide variety of areas in which abstract concepts can be involved. How will the concept of pure duration make specific development? I speculate that what can arise from the concept is merely philosophical self-complacency based on philosophy of life established for its own convenience. I cannot sense any endogenous power of development by itself in this concept.
Music is often mentioned in the context of the concept of pure duration, but I do not think that music makes any sense when spatial entities are removed from their context. Music is like architecture for four-dimensional space-time in which space and time are united. Separating only temporal aspects probably leads you astray from the heart of the matter. You cannot dance without any space. Even if no dancing is involved, the basis of music is in beat and rhythm, not melody. The origin of beat and rhythm is the heartbeat and is based on spatial repetitive movements.
Fundamentally, the vivid activities of life are conducted in a four-dimensional way. This perspective is well and proper for understanding specific aspects of one’s life. The unlimited concept of pure duration just mystifies the essence of life activities.
In fact, it is a sheer reality that the representation of duration exists in our consciousness. It makes sense to study the subject in terms of our awareness of time, but I do not agree with the idea of regarding duration as something fundamental. However difficult it may be, unless we examine how our consciousness of duration arises with a focus on the structure of a four-dimensional cognitive subject, we will not be able to link it with the scientific system.
Certainly, the expressive form of four-dimensional space-time depends on mathematics or a spatial image of its entirety by reducing spatial dimensions. Its appearance may make you think it a product of dead thoughts, which is hugely different from the real world. This is just a form of expression based on the limits of our representational ability, and real existing four-dimensional space-time is something that can be approached, for example, by such expression. What has been expressed should be distinguished from what is being expressed.
(3-4) Perspective of Cognitive Theoretical Criticism
In spite of what I have just described, it is definite that scientifically constructed notions are complicated and difficult to understand without intense learning. Undeniably, we will be induced to feel that those notions are far from primitive. We can become more familiar with something that we can directly feel more than with something we cannot. We are also astounded by the qualitative difference between what we can directly feel and concepts that have been reconstructed by science. Quite certain is that the two are excessively different. I call what we can directly feel qualia(*1) after a word that became trendy in recent years. The question is the difference between scientific time and time’s qualia.
In fact, it is possible to relate sound qualia and color qualia to body organs perceiving air vibrations and light wavelengths as well as those qualia and the nervous system handling information. These are not the same, but they form undeniable correspondence relationships. The point is to what extent we should deny or accept those relationships.
There are wide gaps between the concept of time as interpreted by science and the qualia of time, which is called pure duration or internal sense of time, and time as we perceive it. Those gaps are so wide that it is quite natural for people to find it difficult to recognize both as the same thing.
In addition, there is no guarantee that science is absolutely right. This recognition is stronger among practicing scientists than among those who just accept science. Given that even the great philosophers firmly believed Newtonian dynamics an absolute eternal truth, it is probable that a majority of people suspect that the theory of relativity and quantum mechanics will also suffer a similar demise. Actually, I am one of those people. Throughout history, many specific and detailed theories have been overturned by new discoveries.
Science involves these uncertainties as being not fully reliable. Therefore, naturally, philosophy handles science in a critical and reflective manner in a quest for secure, solid knowledge. In this sense, I support the phenomenological approach of critically examining scientific world models and precisely considering facts arising in consciousness in an introspective way. Scientific knowledge, daily knowledge and philosophical knowledge are all phenomena that occur in human awareness. Even though it may be uncertain if various forms of knowledge are true, the fact that I am thinking now is undeniable. The recognition that this is a definite starting point of discussion is at the core of reflective philosophical thinking. I still remember the vivid impression made on me when I first understood René Descartes’ famous phrase, “Je pense, donc Je suis” (“I think, therefore I am”) when I was in my third year of junior high school. I told my father about the phrase, and he said that this phrase was the starting point of philosophy. I was so delighted to know that, but at the same time, I also wondered what I, who was delighted at that time, was.
Currently, I still have no idea of why I am just the way I am now. I wish I could be more than what I am now, but actually, I am nothing but what I am now. The problem is myself who is abstractly thinking. I am involved in a world with physical and psychological characteristics, abilities and inabilities, and I spend every day consumed with a sense of both inferiority and superiority. The question is what is this concrete myself.
When I was in my second year of junior high school, my mother died. She died all of a sudden. One year before that, my grandfather had died of old age. As a junior high school student, I was very interested in the fact that the entire world was composed of elements and that they were neatly aligned like a chemical periodic table. I tried very hard to memorize atomic symbols. At that time, I happened to see clouds of smoke rising out of the crematory’s chimney twice in short period of time. While looking at that smoke, I was thinking of atomic symbols, such as C and P. I was remembering how gentle my mother had been and also how rigorous she had sometimes been. I was just staring at clouds of smoke in front of me in an absent-minded manner, while considering atomic symbols written in the textbook. I was astonished by this correspondence relationship among these seemingly irrelevant factors. I was so panicky that I was quite at a loss what to think. Under usual circumstances, it would have been natural and appropriate to distinguish between my mother and science, but I completely confused them. Not until long afterward did I understood that philosophy was effective for handling this mess. I was also inspired by my father’s collection of philosophy books.
Personally, I think it impossible to have philosophical thoughts separate from scientific knowledge and this stance stemmed from the formative experiences of my boyhood. What is matter? What is the universe? What is time? What is the existence of one’s self? In my frame of reference, these questions are all connected.
I was earlier interested in the irrationalness of human existence and regarded philosophy as existentialism, which was then popular, but existentialism was based on phenomenology. Because I intended to approach the matter of self-existence in relationship to the universe, I was soon disappointed in existentialism. I got the impression that existentialism was confined to narrow-mined worldviews; existentialism involved difficulty in exploring matters concerning the universe. Phenomenology confines itself inside a wall of strictness and prevents people from actively progressing into systematic thinking. However, I had the awareness of the issue in which the subject of one’s self, the subject of the world, the subject of politics and the subject of life and the universe would all be interconnected. I found myself thinking that the key common denominator of these subjects was time. I learned to think that philosophy was based on materialism from the ontological and epistemological perspectives. Even if you cannot avoid the limits of age and circumstance, you need some form of world model. I came to think that I would be unable to gain anything from assuming a cynical attitude toward the assumption of the world model by regarding it as naive realism. Sophisticated materialism is established where it criticizes naive realism, that is, where it reveals the social mental actions hidden in what is considered to exist regardless of our psychological actions. At the time, materialism was tightly linked with Marxism. I chose Marxism because I focused on materialism. In most cases, the choice of Marxism led to materialism and people told me that my reverse case was quite rare. Whether you choose materialism or idealism and how to approach a major thought movement such as Marxism are different in level and perspective.
I place strong emphasis on securing specificity. Instead of blindly seeking specific knowledge and information, I am attracted by specificity based on abstract and fundamental concepts. The world of science is the richest source of those elements.
Monism is another perspective that I do stick to. Its origin comprises my dead mother, smoke and atoms. This perspective is not just reduced to the pessimistic view that dead people turn into smoke. Although the perspective may include such implications, it is based primarily on more profound and complicated thinking, involving the solemn feeling that human beings are connected with what is created at the universal scale, such as atoms. It seems that I have developed these formative experiences from boyhood into a complicated feeling that I cannot easily express over a long period. That feeling forms the basis for my sticking to monism.
Furthermore, I put little trust in the human mind, including mine. The mind easily betrays people and is not trustworthy. It is undeniable that I have an indescribable emotional attachment to the mind, which is inseparably linked to the body and works as part of body function, as minds are intently living while confronting, depending on, making use of, or supporting each other although they are sometimes troublesome. The mind never exists by itself. Mind body dualism will never fail to face problems at a certain point of time if we approach our specific journey from birth to death and the theory will become deceitful or break down. This can be said even without mentioning advances in cranial nerve science.
The monism of the mind can also exist. This thinking ultimately leads to the idea that only my mind and consciousness are true forms of existence or the idea that everything depends on God’s will. I take neither of these stances, however. In accordance with this reasoning, monism just boils down to materialism in a broad sense.
In the beginning, I had no idea of how to describe this section on epistemological issues. Fundamentally, I am incapable of giving a high-flown argument on philosophical history, and even if I can do that, it is easily imaginable that such argument is far beyond the scope of this section. It is impossible to demonstratively argue about such serious issues. That is why I thought I had no other choice but to fudge by describing how I had chosen a basic philosophical reference point.
Now, I need to mention what stance I will take on the world models that science presents. As previously noted, there is no guarantee that scientific worldviews are absolutely right. A primary reason why I focused on physics is that it comprises the most basic and stable foundation for scientific worldviews, but there is no absolute guarantee for that. In this context, it is conceivable to extract and study general forms of scientific thinking. However, this just follows precedents and prevents me from getting to the core of the subjects of the specific universe and human existence.
After all, I gave up partway and came to the conclusion that it was extremely arrogant for me to try to obtain entire truths because I have only a limited amount of resources. I had no choice other than considering how to shape my limited cognitive ability. What I can examine within the limited scope of my personal knowledge and reflective thinking is limited in content, but science involves an enormous accumulation of human intellectual achievements over a long period of time, before the advent of formal science and philosophy. Those achievements are examined by many specialists and applied to production and medical technologies as support for the foundation of our daily lives. It is essential to acquire valuable knowledge on the basis of those worldviews as the central axis.
Some dubious arguments run rampant in the name of science and it is impossible to evaluate all scientific theories equally. Critical ability to be able to judge the proper scope of science based on the scientific content instead of judging from the outside of science should be explored.
The content of adequately examined scientific knowledge is retained even after theoretical paradigms have been revised. Much of Newtonian dynamics is retained on the basis of the theory of relativity and quantum mechanics. If the theory of relativity and quantum mechanics are subsumed into higher level theories in the future, much of their content will be retained. The minimum test of new theories is their consistency with the scope of what has been adequately examined by existing theories. Based on this assumption, if new theories can go beyond the limits that existing theories cannot exceed and their conclusions can be demonstrated through specific experiments, they will gain credit.
The relativity of simultaneity, which is the most important subject of this book, comprises the basic understanding achieved by the theory of relativity. It is conceivable that the relativity of simultaneity will be re-theorized in the future from other perspectives, but it is unthinkable that the relativity of simultaneity will return to the level of Newtonian dynamics, just as the Copernican system will not return to the Ptolemaic system. For this reason, I placed the relativity of simultaneity as the base of time examinations.
However, if physicists do nothing but describe physical time in a physical manner, philosophical frustration just mounts. I intend to examine time, including the psychological time, in accordance with monism. To conduct such an analysis, it is necessary to present and reconstruct bird’s-eye world models separately from the world of our mind, even if the bird’s-eye model is inadequate. It is inevitable that the reconstructed mind and the real mind are different. Recognizing the correspondence relationship between these two types of mind is just possible, and I accept that. It is significant to sense the connection between the mind and the universe through the reconstruction process. This attitude is much more modest thinking than to blindly make up something sacred.
(*1) individual qualitative feelings of subjective, conscious experience.