Source of book: Borrowed from the library
I previously read Rovelli’s better known book, Seven Brief Lessons on Physics, which is a quick and easy to understand look at the physics revolution of the last century.
The Order of Time is still a short book, but at over 200 pages, it is significantly longer than the other one. It also is more directly connected to the research that Rovelli himself has devoted his life to: Quantum Gravity and Thermal Time.
As with the other book, this one is translated from Italian by Erica Segre and Simon Carnell, who bring the beauty of Rovelli’s prose to life in English.
Based on the previous book, I expected a book that took difficult topics and made them understandable to a lay audience. After all, Rovelli is a great communicator. I was not at all disappointed: this book is definitely that.
But it is more than that. A lot more. From Rovelli’s starting each chapter with a quote from Horace’s Odes, to the liberal references to poetry and literature and philosophy, this book is quite a bit more emotionally moving. It also intersected with metaphysics and theology in ways that I definitely did not expect - and really gave me plenty to think about regarding mortality, human nature, and existence in the world we live in.
I won’t even really try to go into the substantive stuff. Time is, as Doctor Who put it, rather “timey-wimey and wibbly-wobbly.” It isn’t the same everywhere, but moves at different “speeds.” It is dependent on velocity and gravity. At the quantum level, it doesn’t have a direction. It is connected to, well, connections. It is the interactions of spacetime and quantum dimensions that allow us to observe it at all. And it is, well, just really weird.
Rovelli also argues, based on our current understanding of time, that it isn’t some objective passing, or connected to some great cosmic clock. Rather, time is made up of events, occurrences, interactions.
We as humans experience time in a certain way, but our ability to do so is limited. It really is our memory and ability to predict the future based on the past that allows us to see time beyond the present moment.
It is this exploration of the subjectivity of time, and the limitations of human experience that sound strikingly like the theological discussions about eternity and human limitations.
Finally, Rovelli makes a compelling case that all existence - all life for certain - is inextricably tied to an increase in entropy. Life is decay, disintegration, entropy. Life simply builds dams delaying the decay one step at a time in order to harness that decay.
If there were no change in entropy, no life could exist. In fact, a static universe like that could never change, could never live in any real sense.
Again, there is no way I can summarize better than Rovelli’s thoroughly delightful writing and lucid explanations. You really should read the book and enjoy for yourself.
Let me start out with a few of the poetic things. I could have quoted all of the Horace, for sure, but this was my favorite:
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
of events that the fleeting hour
will have assigned to us.”
(III, 29)
The author also quotes the Grateful Dead, in a quote that is simply perfect for the discussion he uses it in.
Look out 'cause here comes some free advice
Walk in the sunshine, watch for the bright sun
Be all those things you're able to be
You got to listen to the heavens
You got to try and understand
The greatness of their movement
Is just as small as it is grand
Try not to hurry, it's just not your worry
Leave it to those all caught up in time
You got to deep-six your wristwatch
You got to try and understand
The time it seems to capture is just the movement of its hands
I ain't preachin', 'cause I don't know
How to make fast things move along slow
Can't stop it, can't make it go
Just 'cause I say it, that don't mean that it's so, no, no
There is a lot more, but I will leave that to the reader. Oh, and many of his illustrations for time use the Smurfs. He clearly has a great sense of whimsy.
I’ll hit a few highlights from the text itself as well.
First, the book literally starts with a simple fact:
Time passes faster in the mountains than it does at sea level.
Did you know that? It’s true. The difference is really small, but you can actually measure it with a precision timepiece, available online for a few thousand bucks.
Why, though? Well, gravity affects time. The more gravity, the slower time. Hence why at the event horizon of a black hole, time…stands still. Hence, “event” horizon. Which, well, that’s pretty wild.
This, in addition to the fact that time slows as the observer approaches the speed of light.
Time also isn’t a continuum, even though we humans experience it that way. Rather, like electron energy levels, or photon energy levels, it exists at particular discrete moments. I love how Rovelli explains this.
Continuity is only a mathematical technique for approximating very finely grained things. The world is subtly discrete, not continuous. The good Lord has not drawn the world with continuous lines: with a light hand, he has sketched it in dots, like the painter Georges Seurat.
I also want to point out this excellent observation, in the passage on the explosion of science surrounding the French Revolution.
Rebellion is perhaps among the deepest roots of science: the refusal to accept the present order of things.
If you want to understand why MAGA and the authoritarians they worship are so anti-science, this is why. MAGA is all about returning to a particular order, with women and minorities put firmly back in their place. Science challenges all of that, as well as the religious and political delusions that MAGA uses to support its hierarchical view of the world.
Science seeks absolute truth, not absolute authority.
One of the figures that features early in the book is Leibniz. You may have heard of him. In addition to co-inventing Calculus, he disagreed with Newton about the nature of time. Leibniz actually agreed with the earlier Greek tradition that time is only the order of events, not some autonomous quantity.
What I hadn’t heard previously about him was the legend (which may or may not be true - no one is sure) that Leibniz, whose name was originally Leibnitz, removed the “t” from his name in protest against the Newtonian idea of time, written in equations as “t.”
Another truly mind-blowing idea in this book is that “things” as such, do not exist. While we humans think of the universe as consisting of objects, it really doesn’t, at the quantum level. What we experience as objects are really just the events of interaction between the various grids of dimension. (He explains this a lot better than I do.) By analogy, then:
What works instead is thinking about the world as a network of events. Simple events, and more complex events that can be disassembled into combinations of simpler ones. A few examples: a war is not a thing, it’s a sequence of events. A storm is not a thing, it’s a collection of occurrences. A cloud above a mounts is not a thing, it is the condensation of humidity in the air that the wind blows over the mountain. A wave is not a thing, it is a movement of water, and the water that forms it is always different. A family is not a thing, it is a collection of relations, occurrences, feelings. And a human being? Of course it’s not a thing; like the cloud above the mountain, it’s a complex process, where food, information, light, words, and so on enter and exit…A knot of knots in a network of social relations, in a network of chemical processes, in a network of emotions exchanged with its own kind.
And later:
We therefore describe the world as it happens, not as it is. Newton’s mechanics, Maxwell’s equations, quantum mechanics, and so on, tell us how events happen, not how things are. We understand biology by studying how living beings evolve and live. We understand psychology (a little, not much) by studying how we interact with each other, how we think…We understand the world in its becoming, not in its being.
As you can see, this is right at the intersection of physics (which in this case is fairly well understood) and metaphysics, philosophy, theology even. God is change.
In another amazing passage, Rovelli uses the analogy of descending from a mountain into a foggy valley, for how our limited perception warps how we see and experience the universe. From afar, the fog looks like a well-defined surface, but as you descend, there is not clear dividing line. Likewise, the surface of my desk here at my office sure seems solid enough, but if I could see it at the atomic scale, it would be a fog of electrons.
We see through a glass, dimly, as Saint Paul would have it. And it is even deeper than that.
If we give a description of the world that ignores point of view, that is solely “from the outside” - of space, of time, of a subject - we may be able to say many things but we lose certain crucial aspects of the world. Because the world that we have been given is the world seen from within it, not from without.
Many things that we see in the world can be understood only if we take into account the role played by point of view. They remain unintelligible if we fail to do so. In every experience, we are situated within the world: within a mind, a brain, a position in space, a moment in time. Our being situated in the world is essential to understanding our experience of time.
Again, very in line with some of the theological ideas that have resonated for me from my childhood. As a friend who was raised Episcopal put it, in her view now, perhaps humans are atoms in God’s body. We see God from the inside, which is why what we see is both incomplete and inseparable from our perspective, our point of view, our vantage point to see.
“In him we live and move and have our being.”
I definitely was the most affected, however, by the explanation of the relationship of entropy and time. It is one of the most lucid explanations of the fundamental truth of “life, the universe, and everything” that I have seen.
Death is not separable from life. If we did not die, we could not live. This is not a theological viewpoint, but a simple fact of the universe. Life is decay. Life is death. And life is fleeting and beautiful anyway.
Regarding these chapters, let me start with this. We mislearn some things in school, and one of them is the idea of “energy.” We are taught that living organisms need “energy” to function. This is not true. Otherwise, we could all park ourselves at Death Valley, where there is plenty of energy, and never have to eat again.
Clearly this doesn’t work.
Because what we need is not energy, but sources of low entropy.
Energy - as I was also told at school - is conserved. It is neither created nor destroyed. If it is conserved, why do we have to constantly resupply it? Why can’t we just keep using the same energy?
The truth is that there is plenty of energy and it is not consumed. It’s not energy that the world needs in order to keep going. What it needs is low entropy.
What makes the world go round are not sources of energy but sources of low entropy. Without low entropy, energy would dilute into uniform heat and the world would go to sleep in a state of thermal equilibrium - there would be no longer any distinction between past and future, and nothing would happen.
Rovelli makes a pretty good case that without changes in entropy, time would not exist. Indeed, time itself consists of changes in entropy.
We are processes, events, composite and limited in space and time. But if we are not an individual entity, what is it that founds our identity and its unity? What makes it so - that I am Carlo - and that my hair and my nails and my feet are considered part of me, as well as my anger and my dreams, and that I consider myself to be the same Carlo as yesterday, the same as tomorrow; the one who thinks, suffers, and perceives?
His answer to this is too long to reproduce here, but it can be summed up as being a point of view, our own perception of ourselves and others as individuals (rather than groups of cells including bacteria that outnumber us), and most importantly, our memory.
This is definitely into the realm of philosophy, metaphysics, and theology. The science can tell us a lot about what, but the why of perception is complex, and not easily reduced to the physics of it all.
I will end with a passage on mortality that I think is just amazing. It really sums up a lot of my own feelings about things.
You can read a bit more about this in my recently posted review of White Noise by Don DeLillo, which is all about the fear of death.
I would not wish to live as if I were immortal. I do not fear death. I fear suffering. And I fear old age, though less now that I am witnessing the tranquil and pleasant old age of my father. I am afraid of frailty, and of the absence of love. But death does not alarm me…I love life, but life is also struggle, suffering, pain. I think of death as akin to a well-earned rest. The sister of sleep, Bach calls it.
The Order of Time is pretty mind-blowing in so many ways. But it also is, surprisingly, deeply human. Rovelli’s ability to combine both science and humanity is a great reason I love his writing.
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