It is entropy, not energy, that keeps stones on the ground and the world turning.
The entire coming into being of the cosmos is a gradual process of disordering, like the pack of cards that begins in order and then becomes disordered through shuffling. There are no immense hands that shuffle the universe. It does this mixing by itself, in the interactions among its parts that open and close during the course of the mixing, step by step. Vast regions remain trapped in configurations that remain ordered, until here and there new channels are opened through which disorder spreads.99
What causes events to happen in the world, what writes its history, is the irresistible mixing of all things, going from the few ordered configurations to the countless disordered ones. The entire universe is like a mountain that collapses in slow motion. Like a structure that very gradually crumbles.
From the most minute events to the more complex ones, it is this dance of ever-increasing entropy, nourished by the initial low entropy of the universe, that is the real dance of Shiva, the destroyer.
TRACES AND CAUSES
The fact that entropy has been low in the past leads to an important fact that is ubiquitous and crucial for the difference between past and future: the past leaves traces of itself in the present.
Traces are everywhere. The craters of the moon testify to impacts in the past. Fossils show the forms of living creatures from long ago. Telescopes show how far off galaxies were in the past. Books contain our history; our brains swarm with memories.
Traces of the past exist, and not traces of the future, only because entropy was low in the past. There can be no other reason, since the only source of the difference between past and future is the low entropy of the past.
In order to leave a trace, it is necessary for something to become arrested, to stop moving, and this can happen only in an irreversible process—that is to say, by degrading energy into heat. In this way, computers heat up, the brain heats up, the meteors that fall into the moon heat it; even the goose quill of a medieval scribe in a Benedictine abbey heats a little the page on which he writes. In a world without heat, everything would rebound elastically, leaving no trace.100
It is the presence of abundant traces of the past that produces the familiar sensation that the past is determined. The absence of any analogous traces of the future produces the sensation that the future is open. The existence of traces serves to make it possible for our brain to dispose of extensive maps of past events. There is nothing analogous to this for future ones. This fact is at the origin of our sensation of being able to act freely in the world: choosing between different futures, even though we are unable to act upon the past.
The vast mechanisms of the brain about which we have no direct awareness (“I know not why I am so sad,” mumbles Antonio at the beginning of The Merchant of Venice) have been designed during the course of evolution in order to make calculations about possible futures. This is what we call “deciding.” Since they elaborate possible alternative futures that would follow if the present were exactly as it is except for some detail, we are naturally inclined to think in terms of “causes” that precede “effects”: the cause of a future event is a past event such that the future event would not follow in a world that was exactly the same except for this cause.101
In our experience, the notion of cause is thus asymmetrical in time: cause precedes effect. When we recognize in particular that two events “have the same cause,” we find this common cause102 in the past, not in the future. If two waves of a tsunami arrive together at two neighboring islands, we think that there has been an event in the past that has caused both. We do not look for it in the future. But this does not happen because there is a magical force of “causality” going from the past to the future. It happens because the improbability of a correlation between two events requires something improbable, and it is only the low entropy of the past that provides such improbability. What else could? In other words, the existence of common causes in the past is nothing but a manifestation of low entropy in the past. In a state of thermal equilibrium, or in a purely mechanical system, there isn’t a direction to time identified by causality.
The laws of elementary physics do not speak of “causes” but only of “regularities,” and these are symmetrical with regard to past and future. Bertrand Russell noted this in a famous article, writing emphatically that “The law of causality . . . is a relic of a bygone age, surviving, like the monarchy, only because it is erroneously supposed to do no harm.”103 He exaggerates, of course, because the fact that there are no “causes” at an elementary level is not a sufficient reason to render obsolete the very notion of cause.104 At an elementary level there are no cats either, but we do not for this reason cease to bother with cats. The low entropy of the past renders the notion of cause an effective one.
But memory, causes and effects, flow, the determined nature of the past and the indeterminacy of the future are nothing but names that we give to the consequences of a statistical fact: the improbability of a past state of the universe.
Causes, memory, traces, the history itself of the becoming of the world that unfolds not only across centuries and millennia of human history but in the billions of years of the great cosmic narrative—all this stems simply from the fact that the configuration of things was “particular” a few billion years ago.105
And “particular” is a relative term: it is particular in relation to a perspective. It is a blurring. It is determined by the interactions that a physical system has with the rest of the world. Hence causality, memory, traces, the history of the happening of the world itself can only be an effect of perspective: like the turning of the heavens; an effect of our peculiar point of view in the world. . . . Inexorably, then, the study of time does nothing but return us to ourselves.
12 THE SCENT OF THE MADELEINE
Happy
and master of himself
is the man who
for every day of his life can say:
“Today I have lived;
tomorrow if God extends for us
a horizon of dark clouds
or designs a morning
of limpid light,
he will not change our poor past
he will do nothing without the memory
of events that the fleeting hour
will have assigned to us.” (III, 29)
Let us turn to ourselves, then, and to the role we play in relation to the nature of time. Above all else, what are we as human beings? Entities? But the world is not made up of entities, it is made from events that combine with each other . . . So what, then, am “I”?