Salvatier on the detail in reality
📚SOURCE
💎PERMANENT NOTES
🧵SYNTHESIS
Salvatier begins with a staircase. He spent a summer doing building work with his father and had assumed stairs were simple: two long boards at a slope and some steps between. Then he had to make some. The boards need cutting at an angle at both ends so that they sit flat, and the angle has to be worked out. The screws need to go in at particular places or the wood splits. The boards themselves are not straight. Every step of an apparently simple job opens into further steps that were invisible from outside it.
He generalises in two directions. First, this is true of everything, including things that look trivial, such as boiling water, which turns out to have a history of surprises once people measured it carefully. Reality is detailed all the way down and the details are not optional: they decide whether the thing works.
Second, and this is the subtle part, the details vanish again once you know them. Before you meet a detail you cannot see it. After you have absorbed it, it seems so obvious that you forget it was ever hidden. So people stuck on a problem are often missing a detail they do not know exists, and experts cannot understand why the novice is stuck.
✨KEY IDEAS
A task that looks like two steps from outside turns into dozens once your hands are on it.
The details are not noise around the plan. They are where success or failure is decided.
Once learned, a detail becomes invisible to the person who knows it.
Being intellectually stuck often means the thing you need is something you have not yet noticed, not something you have weighed wrongly.
He advises deliberately hunting for what you are failing to notice.
📝READING NOTES
Paraphrase, not quotation. An essay from 2017. Priya sent the link on Saturday 15 March with one line: this is Tuesday night. I read it that afternoon with a taped finger, and wrote this on the Sunday.
Tuesday night
For the record, since the note depends on it. We launched at 21:00 on 11 March. From 23:40 the system began producing duplicate exceptions. We rolled auto-triage back at 02:40 and called all clear at 03:15.
The plan had been reviewed, load-tested twice, rehearsed in a dry run, and put through a pre-mortem the day before. The cause sat in a detail that none of those could show, because none of us knew to look for it. When Priya explained it at about one in the morning it took her two sentences, and my first reaction was that it was obvious. Which is Salvatier's second point exactly: a detail goes from invisible to obvious with no stage in between where you could have been expected to find it.
What I conclude
- A plan cannot hold the detail. No amount of care would have made ours hold it. 💎 Reality has more detail than any plan can hold.
- So the plan must include the means of finding out. Staged exposure, a rollback that works at 02:40, someone awake who can read the logs.
- Blame is a category error. If the detail was invisible beforehand, nobody failed to see it. I want the write-up to say this without sounding like an excuse: 📌 Write up the launch incident with Priya, due Tuesday.
- It also explains the other end of the launch. Our three-week slip in February was detail arriving early.
Where I am not sure he is right
- He comes close to saying planning is futile. I do not think the stairs teach that. His father knew the details. Experience is stored detail, and a plan made by someone who has built ten staircases is a different object.
- Not every detail matters equally. Reality has endless detail and most of it is irrelevant to the outcome. The skill is knowing which. He gestures at this and moves on.
- The essay is itself rather low on detail about how to notice what you are not noticing.
Next to
📖 Bernhardsson on why projects run late, from three weeks ago, is the statistics of this essay: each hidden detail is a small chance of a large overrun. And 📖 Meadows on why systems surprise us is the same humility at the scale of a whole system.
Took the staircase to the ☕ Launch retrospective on the 19th as the opening two minutes. It set the tone better than a slide of principles would have.
Reading record
- Sent by: Priya Raman, the Saturday after the launch
🗣️IN SHORT
- In : Reality has a surprising amount of detail, John Salvatier, 2017
- Salvatier argues that : every real task contains far more relevant detail than can be seen from outside it, and that this detail is invisible both before and after it is learned
- by stating that : building a simple staircase revealed dozens of hidden steps, that the same holds for any physical or intellectual work, and that people get stuck because they cannot perceive details they have not yet met