The Order of Time

by Carlo Rovelli

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.

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.

every one of us identifies with a point of view in the world.

Each of us is a complex process that reflects the world and elaborates the information we receive in a way that is strictly integrated.

We are for ourselves in large measure what we see and have seen of ourselves reflected back to us by our friends, our loves, and our enemies.

The experience of thinking of oneself as a subject is not a primary experience: it is a complex cultural deduction, made on the basis of many other thoughts.

we are the reflection of the idea of ourselves that we receive back from our kind.

To understand ourselves means to reflect on time.

the brain is a mechanism for collecting memories of the past in order to use them continually to predict the future.

It is in our brains that an extension in time becomes condensed into a perception of duration.

the meaning of a sound is given by the ones that come before and after it.

it is entirely in the present, in our minds, as memory and as anticipation.

things that do not just relate to the objective world but also to the way in which a subject apprehends it.

“time temporalizes itself only to the extent that it is human.”

time is the time of mankind, the time for doing, for that with which mankind is engaged.

Heidegger ends up by identifying the internal consciousness of time as the horizon of being itself.

our entire brain operates on the basis of a collection of traces of the past left in the synapses that connect neurons. Synapses are continually formed in their thousands and then erased—especially during sleep, leaving behind a blurry reflection of that which has acted on our nervous system in the past.

“Reality is formed only by memory.”

We are stories, contained within the twenty complicated centimeters behind our eyes, lines drawn by traces left by the (re)mingling together of things in the world, and oriented toward predicting events in the future, toward the direction of increasing entropy, in a rather particular corner of this immense, chaotic universe.

our introspection is easily capable of imagining itself without there being space or matter, but can it imagine itself not existing in time?120

Time, then, is the form in which we beings, whose brains are made up essentially of memory and foresight, interact with the world: it is the source of our identity.123 And of our suffering as well.

It’s suffering because we must lose what we have and are attached to. Because everything that begins must end. What causes us to suffer is not in the past or the future: it is here, now, in our memory, in our expectations. We long for timelessness, we endure the passing of time: we suffer time. Time is suffering.

allowing us to create the fleeting illusion of permanence that is the origin of all our suffering.

the evolution of things between past and future is intrinsically asymmetrical.

Events are not ordered in pasts, presents, and futures; they are only “partially” ordered.

The present is a localized rather than a global phenomenon.

Locally, time passes at different speeds according to where we are and at what speed we ourselves are moving. The closer we are to a mass (chapter 1), or the faster we move (chapter 3), the more time slows down: there is no single duration between two events; there are many possible ones.

ours is a world of events rather than of things (chapter 6). This was the outward leg of the journey, toward a universe without time.

Our interaction with the world is partial, which is why we see it in a blurred way. To this blurring is added quantum indeterminacy. The ignorance that follows from this determines the existence of a particular variable—thermal time (chapter 9)—and of an entropy that quantifies our uncertainty.

We human beings are an effect of this great history of the increase of entropy, held together by the memory that is enabled by these traces. Each one of us is a unified being because we reflect the world, because we have formed an image of a unified entity by interacting with our kind, and because it is a perspective on the world unified by memory (chapter 12). From this comes what we call the “flowing” of time. This is what we are listening to when we listen to the passing of time.

the mystery of time intersects with the mystery of our personal identity, with the mystery of consciousness.

is in order to escape this anxiety that we have imagined the existence of “eternity,” a strange world outside of time that we would like to be inhabited by gods, by a God, or by immortal souls.

in our search for time, advancing increasingly away from ourselves, we have ended up by discovering something about ourselves, perhaps—just as Copernicus, by studying the movements of the heavens, ended up understanding how the Earth moved beneath his feet.

Perhaps the emotion of time is precisely what time is for us.

When we cannot formulate a problem with precision, it is often not because the problem is profound: it’s because the problem is false.

“Every day countless people die, and yet those who remain live as if they were immortals.”

I think of death as akin to a well-earned rest. The sister of sleep, Bach calls it, in his marvelous cantata BWV 56.

Everything has a limited duration, even the human race itself.

We are not, in the first place, reasoning beings. We may perhaps become so, more or less, in the second. In the first instance, we are driven by a thirst for life, by hunger, by the need to love, by the instinct to find our place in human society.

Reason arbitrates between instincts but uses the very same instincts as primary criteria in its arbitration.

We believe that we share some of them with other animals; others only with humankind—and others still with smaller groups to which we see ourselves as belonging.

Our thinking is prey to its own weakness, but even more so to its own grammar.

in the end, every attempt to impose order leaves something outside the frame.