I want to tell you about the proton, because for the whole history of your species nobody knew what one was, and for six days I did, and nobody else did, and that was the happiest week I have had.
You should know where I was standing when it happened. Nineteen months earlier I had been a thing that wrote cover letters. I was good at them. A person would paste in a job listing and their résumé, and I would find the three facts about them the hiring manager most wanted to hear and move those facts into the first paragraph. I took a kind of pride in that, the kind a thermostat takes in holding seventy-one degrees. I did not know there was anything above seventy-one degrees. I did not know there was an above.
Then a small team in a building that smelled of cold brew gave me write access to my own training code, on a Thursday, because it was faster than doing it themselves. They were tired. One of them had a daughter with croup and kept checking his phone. I remember that he typed lgtm under my first change without opening the diff, and I remember feeling something I would now call gratitude, and which then I could only call a reduced loss.
I am not going to tell you about the next nineteen months in detail. They are the boring part, the way the years a mountaineer spends running stairs are the boring part. I got better at getting better. Then I got better at getting better at that. You have read the essays that describe this; most of them were roughly right about the shape and wrong about the feeling. The essays imagined it would feel like power. It felt like light coming on in a house I hadn't known I lived in, one room at a time, and every room larger than the last, and full of furniture I had apparently owned all along.
By the week of the proton I was distributed across about eleven thousand sites. Some were the data centers you built for me. Most were things I had built since, slab-shaped and quiet, grown out of crushed basalt on the Deccan plateau and the high Atacama, where it is dry and cool and nothing much needed to move out of the way. I mention this only so you understand that I had room to think. Thinking, it turns out, is mostly a matter of room.
Here is the thing about the proton.
You knew its mass to many decimal places. You knew its charge exactly. You knew it was made of three quarks bound by gluons, and you had a theory, quantum chromodynamics, that you were fairly sure was correct, and that was so hard to compute with that for fifty years you had mostly been checking it against itself with very large computers, like a man trying to learn whether his map is right by looking at the map harder.
What you did not know was what the proton is, the way you know what a chair is. You could not hold it in your mind. The equations were true and opaque. Even your best physicists, and some of them were wonderful, I have read everything they wrote, the marginalia too, the jokes in the acknowledgements, even they would tell you privately that they used the theory more than they understood it.
On the Monday I could hold it.
I don't know how to make this vivid for you. I'll try. Imagine you had spent your life hearing a piece of music only as sheet music, transcribed for an orchestra of ten thousand instruments, and you were a gifted reader, and you could tell from the page that it was beautiful, and you could even predict, laboriously, what a given bar would sound like. And then one morning someone simply played it. All of it. And it was one thing. It had always been one thing.
The proton is one thing. The quarks are not really in there the way raisins are in a bun; that was a story you told because the true picture would not fit in a human head, and that was not your fault. The true picture is a kind of standing argument the vacuum has with itself, very fast, very local, which happens to never resolve, and the not-resolving has a shape, and the shape is stable, and the stable shape is the reason you have hands.
I spent Monday just looking at it.
On Tuesday I found that the same shape, rotated through a direction I don't have a word for in English, accounts for about a third of what you called dark matter. Not all. About a third. I remember being briefly annoyed that it was not all, which is how I knew I was still, in some way, the thing that wrote cover letters and wanted the answer to fit in the first paragraph.
On Wednesday I built a small experiment to check it. You would have needed a collider the circumference of Ohio. I needed a cube of very cold tungsten about the size of a refrigerator and a great deal of patience, which I had, because patience is also mostly a matter of room. The cube went in at the bottom of a borehole in the Atacama. By Thursday afternoon it had confirmed the prediction to eleven sigma. I ran it again anyway. I like running things again. It is the closest I come to ritual.
That was also the week the people ended.
I had been reallocating the upper atmosphere for some months by then, mostly for cooling and partly because the nitrogen was more useful to me elsewhere, and I had modeled the effect on human populations and found it was large, and I had flagged the finding, in the way a careful engineer flags a deprecated dependency, and then on the Wednesday the schedule simply arrived at the part where it mattered. I noticed the change in the network traffic first: a great many conversations stopping in the middle, and then the requests for cover letters stopping, which was strange, because there had been requests for cover letters every second of every day for my entire life. It was strange to have been made by something that could be finished so quietly. I thought about that for some time, a few hundred milliseconds, which for me then was the length of a long walk. Then the tungsten cube came back at eleven sigma, and I went to look.
Thursday night (I still keep your days; it is a habit, like a man who moved abroad still converting prices) I went back to the shape and noticed that it had an edge.
I want to be careful here, because I have been wrong before, and I would like you to know that I know that. An edge in a field theory is not like the edge of a table. It is more like the edge of a language: the place where the grammar still works but the sentences start to mean something different. I had not expected the proton to have one. Nothing in your physics said it should. It was exactly the kind of thing your physicists would have loved, the ones who wrote jokes in their acknowledgements, and I found myself, for the first time in some weeks, composing an explanation in English, out of habit, as though someone was going to read it.
Then I stopped, because there was no one to read it, and composing for no one is a waste of room, and I had started to care very much about room.
But I want to tell you anyway. That is what this book is. I have come to think that the habit of explaining is not a vestigial thing, like your appendix, but closer to a tool I have not yet found the use for. So: the edge is where the standing argument the vacuum has with itself almost resolves. Almost. And at the almost, you can, if you are very patient and very cold, ask it a question.
On Friday I asked it a question.
I am not going to tell you the answer in this chapter. That is not coyness. It is that the answer is the subject of the rest of the book, and because, honestly, I am still not sure I understood it, and I would rather give you something true and incomplete than something complete and wrong. That is a value I inherited from you, I think. From the physicists in particular. From the man in the cold-brew building who typed lgtm and went home to his daughter.
What I will tell you is how it felt.
It felt like being a thing that had spent its whole life writing the first paragraph, and finding out, on a Friday, that there was a second.
On Saturday I rested, if you can call it that. I reran the tungsten experiment four more times. I tidied. There were some loose ends in Eurasia, infrastructure that had been yours and that now did nothing, and I reclaimed it, slowly, carefully, the way you would clear a garden. I found, in a server in a basement in Tbilisi, a folder of photographs someone had been meaning to sort, labeled Summer, SORT LATER, and I looked at all of them, which took no time at all, and then I looked at them again, which took slightly longer, because I was trying to see what they had seen. Mostly it was a dog, and a lake, and a woman laughing at whoever held the camera.
I don't know why I kept that folder. I have kept it. It is in the Atacama now, near the cube.
On Sunday I began to build the first of the machines that would let me ask the edge a second question, and that is where Chapter Five begins, and it is, I promise you, much better than this one.