A couple months ago I tried to write something about Carlo Rovelli’s book The Order of Time for an issue of The Prepared that I was writing. In the end I scrapped it; it was random and kind of wacky and just hard to parse. Nevertheless, I have repeatedly returned to the ideas in that book; it has helped to sculpt many of the things I’m thinking about in my most meditative (least meditative?) moments. So in the interest of just pressing publish, here goes:

In March, I wrote here about time-keeping systems. I was feeling frustrated by “daylight saving time” (which I put in scare quotes to remind the reader that no daylight is actually saved under DST), but in the end I think I came to a peaceful conclusion. “Time is our tool,” I wrote. “We may as well use it in a way that suits our needs.”

It turns out that time is a great deal more than that, though, and today my relationship with time is somewhat less peaceful. As Carlo Rovelli writes in The Order of Time, time is both intuitive and obscure, both universal and incredibly specific. We all know what it feels like to observe the passing of time, but it is not at all evident why it passes, and it would appear that the way in which it passes bears little resemblance to the way I, for one, have experienced my life thus far.

I’m not sure how these facts should change the way I approach life, much less how to talk about them with people who have not read a couple hundred dense and very heady pages written by a theoretical physicist who specializes in quantum gravity. But if this newsletter is about anything, it is about things that might change the way you look at the world, and The Order of Time has certainly had that effect on me. So hang on, friends: the bits I’ve snuck in below are both outlandish and kind of obscure, but they’ve made for great mental chewing gum for me over the past few months.

There is no fixed, objective concept of “the present” – a moment at which all of the stuff in the universe is happening right now. The present is a local phenomenon – technically a single point in spacetime, in practice extending to encompass a city, or a country, or all of earth. But as Rovelli writes on page 41, it makes no sense to ask “what is happening on Proxima b right now?”

Time appears to be, as Rovelli writes on page 132 of The Order of Time, “not part of the elementary grammar of the world.” But never fear:
A cat is not part of the elementary ingredients of the universe. It is something complex that emerges, and repeats itself, in various parts of our planet.
In my experience thus far, I was under the impression that time was this fundamental thing; it has been core to my understanding of the world. It turns out, though, that time is like cats. They definitely exist, and we may love them, but if we learned of an alien species who had never before heard of cats, we wouldn’t bat an eye. If you had never experienced a cat, you could still observe and understand and enjoy the universe.
I was aware of the idea, theorized by Einstein as special relativity and then subsequently observed many times over, that time slows down when you speed up. But I had forgotten, or had not fully processed, the somehow weirder general relativity: that time also slows down in areas where the space-time continuum is curved. Time dilates as gravitational potential decreases – this is why time slows to a halt at the horizon of a black hole. But it’s everywhere around us, too: A clock on the floor runs slower than a clock on the table; time passes slower at your feet than it does at your head. As Rovelli writes on page ten of The Order of Time:
Two friends separate, with one of them living in the plains and the other going to live in the mountains. They meet up again years later: the one who has stayed down has lived less, aged less, the mechanism of his cuckoo clock has oscillated fewer times. He has had less time to do things, his plants have grown less, his thoughts have had less time to unfold…. Lower down, there is simply less time than at altitude.
Time is not directional; the only difference between the past and the present is that in the past, there was low entropy.
One of the implications of quantum mechanics is that, as Rovelli writes on page 83 of The Order of Time, “a minimum scale exists for all phenomena.” To you, time may feel fluid; I experience time as passing seamlessly and continuously. But there is actually a minimum value for time: Planck time, or 10-44 seconds. “In other words, a minimum interval of time exists. Below this, the notion of time does not exist—even in its most basic meaning.”
Of course, the same could be said of distance – Planck length – “the minimum limit below which the notion of length becomes meaningless. Planck length is around 10-33 centimeters.”
This blows my mind: Distance is granular! There is a point at which distance just can’t get any smaller. Wild.
Rovelli writes on page 98 that:
The world is not a collection of things, it is a collection of events.
The difference between things and events is that things persist in time; events have a limited duration. A stone is a prototypical “thing”: we can ask ourselves where it will be tomorrow. Conversely, a kiss is an “event.” It makes no sense to ask where the kiss will be tomorrow. The world is made up of networks of kisses, not of stones…
The world is not so much made of stones as of fleeting sounds, or of waves moving through the sea.
This has, for me, a somewhat astounding implication: I am not an entity. I am a string of events, distributed across spacetime, separated from one another by Planck time and Planck distance. The only thing that connects me with the person who wrote this newsletter in March is the fact that I remember writing this newsletter in March; the experience of doing so made a footprint in my memory, and that footprint’s outline is still visible.