I’ve just started to read Hans Reichenbach’s The Direction of Time and lines of thought came to life before I’d even finished Hilary Putnam’s foreword for the 1991 reprinting of an English translation by the University of California Press.
I’ll probably write multiple essays on this subject of the direction of time, though it doesn’t seem to be a major problem in my worldview. But it does provide some interesting openings for various explorations of that worldview. I’ll start off by explaining in this essay why the direction of time isn’t a major problem in my worldview, though I’ve noted in past essays that there is no inherent reason known to mathematicians or physicists why time in a universe like ours moves in any one particular direction. See As the Universe Ages, It Forgets What It Once Was for a recent discussion of some general issues regarding time and the universe.
We live in a concrete, highly particularized, universe in which a variety of decisions have, in a manner of speaking, been made — I qualify matters only to leave room for the truth that God is a Creator whose ways of deciding and implementing His decisions in Creation aren’t fully describable in terms of creaturely deciding or creaturely acting. There are a number of physical constants which appear in equations of gravitational force or electromagnetic force, classical or quantum, or nuclear physics or… Though we know not what the exact shape of spacetime is, it seems clear that it has a set of highly particular properties though there are vast numbers of possibilities just in the geometries, topologies, and differential structures currently being considered as the most plausible, or even the barely plausible, for our universe as we currently know it.
From a practical standpoint, the answer to the question, “Why does time move only in the direction we label as `forward’?” is simply: That’s the way the world is. We are creatures of such a world and our minds work as the world works.
Let me unbundle that a little. In my worldview, as I’ve often explained, I’ve restated the symmetry speculations of physicists and mathematicians in a somewhat sharpened but more meta-physical way:
- Created being lies on a spectrum from the more abstract to the more concrete, where the more concrete is shaped from the more abstract.
- Abstract forms of created being remain in the concrete forms which are shaped from them — this can be considered the soul-like aspects of things, especially living things.
- The directly perceivable aspects of our universe are the aspects of very particular, concrete, thing-like, being.
- We see the universe as a story being told by the Creator when we come to some understanding, however incomplete and imperfect, of the specific moral purposes of the Almighty.
Let me move a bit beyond my first answer: Time moves as it does because of the need for moral intention in the Thomistic sense, that is, moral growth and development processes. As individuals and as communities and as the Body of Christ as a whole, we intend toward a certain state which has proven to be quite a moving target, which is hardly unexpected since we can’t see even possibilities too far into the future and rarely can be sure about what will happen an hour from now. The basic idea remains the same: we are to first of all accept reality as it is and not just to accept the behavior of atoms before denying the equal but more perceptible reality of moral behavior, in men and wolves, and the immaterial aspects of relations in general.
The universe isn’t forced into the mold of a world, a morally well-ordered story. The universe naturally moves in such a way that certain types of evolution and development occur. Lines of creatures arise which evolve into lines of social creatures. Stable societies, at least at the level of mammals and birds, involve behaviors which can be properly labeled as `moral’, however defective or incomplete the behavior of social birds or rodents. Moral natures and minds and other immaterial entities arise naturally in this world and those immaterial entities are `made up’ of relations as the heart is made of flesh and blood. The language is clumsy for now, though I can hope we’ll learn to speak more clearly as we recognize more explicitly that the immaterial aspects of physical creatures are fully as real as the mathematically describable abstract entities which freeze into the stuff of this world. See my recent essay, Frozen Soul and Other Delicacies for a discussion of the symmetry-breaking process by which a force unobservable — as yet — in this universe, the electroweak force, breaks down into the electromagnetic force and the weak nuclear force. For that matter, a little knowledge of the problems that Faraday and others had in establishing the existence of magnetic fields should hint strongly at the truth that we really can’t observe electromagnetism in the same way we can observe a tomato plant or a hunk of asphalt. Fields of all sorts can be directly explored by physical means but they have much of the nature of entities more abstract than the more concrete forms of thing-like being.
Even from a physical standpoint, we’re seeing a universe which makes no sense unless we see it as somehow moving toward certain local goals of order. The universe as a whole has to be seen as at least providing the large-scale setting for the regions of order, even if that order often has immaterial aspects of the sort not to be explored in the way of an experimental physicist — economics and other social sciences remain historical arts more than sciences as we understand the term nowadays. In terms of an anthropomorphic argument, you could move on to draw various sorts of weak or strong conclusions about us not existing to observe the universe unless it were a certain sort of entity or even that the universe in some sense is made for us. This smells too much of subjectivism though the arguments aren’t entirely wrong. If we are to find objective truth of a grander sort, we have to retain an objective attitude when we study the universe — most specifically in terms of its current phase of expansion. We must assume the universe is an entity which exists and see what that means before we start discussing a creature which came to exist 13 billion years or so after the start of that expansion.
The very violent beginning to the current expansion of the universe, the so-called Big Bang, was from a state so highly specific as to dictate the direction of entropy — that initial state of this expansionary phase was so particular that it had very little entropy. Entropy tends strongly to increase because that state of the universe was so particular, that is, so low in probability. The universe is moving over a path which is taking it toward a state higher in probability. The story God is telling is that path. And far more. But at least that path.
The universe follows that path as it — so to speak — seeks a more probable and more stable state and that path is headed toward that state, headed in a direction we label `into the future’. It would seem the universe is yet at a state of relatively low entropy, but we don’t know what the comparison is. We know only the facts — the universe moves in one direction in time as-if consciously seeking some different state. That movement has allowed the development of complex structure which develop by decreasing their own entropy and, as a consequence, increasing the rate of the overall increase of entropy of their environments. It isn’t possible to use energy with perfect efficiency, hence there are no perpetual motion machines, and, hence, any local movements toward lower entropy, such as the development of a living organism or the growth of a civilization, will cost some entropy overall.
The story moves on. How do we come to learn this?
The human brain can be seen as evolving at the species level and developing at the individual level. When we expand our perspective to the mind, the immaterial aspects of human intelligence, then we have to make more complex statements involving human communities. I think much confusion about human thought-systems, with their insights and defects, comes from some sort of tendency to think of the human mind as being something independent from the evolving human brain. Let me suggest, quite speculatively, that a child learns about the direction of time by being constrained to see certain streams of events as the development of an entity with constant existence. The constraints come from the strong built-in belief that things have continuous and permanent existence.
The child sees a kitten and then sees it grow and develop into a somewhat different animal but, the instinct remains to think it’s the same it was when it was a tiny helpless kitten. The child sees seeds placed in the ground or perhaps a piece of potato suspended in a clear drinking-glass. Where the seed was buried, a plant rises. The piece of potato begins to grow stalks and then leaves. That child is shaping his mind as he actively responds, including those responses which are tied to seemingly passive but attentional perception. He sees things which continue to exist but they change. At some point, not too many months after gaining some toddling fluency in language, he’s ready to be integrated into the surrounding stories. At first, he listens as an adult reads to him of, perhaps, an Easter bunny which grows and prospers under the care of a child and his mother. He hears stories of exotic animals and perhaps of children going on simple adventures at a farm or even in a jungle across the ocean.
I don’t know what sorts of socializing stories a child might hear in our brave, new world, but we once heard stories about the farmer and the milkman and the policemen. We heard, however implicitly, of the formation of communities and the formation of human bonds, concrete and even those somewhat abstract bonds to those who worked in far distant lands to provide us with bananas. Looking back, I still have good memories from my pre-teen years of reading a series of properly whitewashed biographies of great men and women. I think I learned a lot about moral order and even a bit of history from those books however distorted those books were in some ways, but properly distorted in ways better clarified in later years.
Children generally acquire a naive but plausible and basic understanding of the nature of long-lasting entities, and learn of the error of some of their assumptions when Grandpa disappears one day. The little boys and girls, siblings and cousins, might hear of a place called Heaven or they might hear some vaguer words meant to comfort by obscurity. Often, I fear, they hear a form of obscurity which is a verbalization of their parents’ confusion and lack of well-defined faith.
This is where two of my concerns meet. There is substantial evidence gathered by brain-scientists that human beings are born with certain important instincts about their environments of things and living things and relationships. Those instincts are part of the foundation of sophisticated views of moral causation — found in more human beings than sophisticated views of physical causation. Given my beliefs in the nature of the human mind, its capability of shaping itself to reality, given the overall shape of pathways through time which are traveled by stars and living creatures alike, those forms of cause-and-effect which relate to the moral order would seem more fundamental than more physical forms of cause-and-effect. We’re creatures who strive to see order in our complex perceptions of static environments and in dynamic streams of events and moral causation is generally even more important to us than physical causation. Often enough, we delude ourselves, a well-researched problem since it can even distort the work of trained observers. We tend to see creaturely forms of purpose in our environments and that is nowadays labeled as `anthropomorphic’. In our modern efforts to deal with this error, there are many, including some serious philosophers and theologians and scientists, who throw the baby out with the bathwater, forgetting that it remains at least an open question as to the nature of causation at more abstract levels of being, let alone at the level — however speculative — of the Creator.