In the end I screwed some wall shelves in and called it good enough.
Momentarily baffled, I realized that, despite appearances, the old frame was actually not square, in fact it was a parallelogram. I'd measured the height and width and assumed it was square. The previous (experienced) carpenter who'd built the doors I was replacing had clearly noticed this, and simply allowed for the misalignment in his design. He built perfectly square-appearing doors that mounted to the not-square frame. I had to go back and rework mine considerably for them to fit without looking ridiculous. They're still there and holding up well, but I also still think of this lesson on a regular basis in my day to day life now.
Here's the thing we - a flat full of nerdy tech students - never figured out.
The walls in two of the bedrooms (including mine) were perfectly plumb, all four walls straight. Bookshelves lined up nicely with the walls. The floor was flat and level.
But the room was 10cm narrower at the ceiling.
If you built the bookshelf in wood, it will be expanding, contracting and shifting over time with temperature and humidity variation throughout the day and season. And asymmetrically depending on the grain.
The straight right angles won't stay that way, and it's better to design such that they change in complementary ways, rather than remain perfect.
The walls aren't straight, either vertically or horizontally, and they're not even consistently wonky along any given axis.
So I installed uprights vertically, using transparent polycarbonate spacers of different depths at the attachment points[0]. I then installed shelves on the uprights and aligned them horizontally.
The variation is only +/- 6mm or so (for around 12mm variation across the 2.5m x 2.44m wall) but, if I hadn't done this, my shelves wouldn't be level, and wouldn't even be consistently non-level, so would have been awkward to install along the full length of the wall, would all be misaligned with eachother, and would have looked incredibly janky.
[0] In hindsight I wish I'd gone for these in different colours rather than just plain transparent, to make more of a feature of them. The walls are white so I think orange, blue, red, and yellow would have worked well.
This must be a well-known fact to all trades people who work on cupboards, tiling, door mounting, etc. But when you understand this, then you realize that everything is built to be forgiving of this reality.
E.g. prefabricated bedroom cupboards will always be fitted with fillers on each side and a kickboard for the bottom. This allows you to use feet/wedges underneath the cupboard to make it stand-up perfectly straight (which is not necessarily parallel with the floor and/or walls), but because of the fillers/kickboard being wide/tall enough and cut to fit the irregular/skew shape, you don't tend to notice.
Beading around wooden door frames is for the same reason, it hides the little gap that is invariably at points around it, either due to the hole in the wall being skew and/or slightly arched.
I definitely prefer that with software it can be “perfect” and easily changed later if you find it’s not.
Also learned that lath and plaster needs some special consideration when screwing/nailing things for securement, as the lath (wood strips) could split, causing a subsequent crack in the plaster. Basically for screws or bigger nails, it’s a good idea to drill a small hole first to lessen the pressure, or do a bigger hole and use a spring bolt anchor.
Hate hate hate hate hate
I can never look at staircases the same.
Soon you realize that an surprising amount of walls are just not straight or level.
I put up a notice board in my kitchen when I moved into a new place, and it looked squint even though my level said it was straight. I flipped the spirit level end-for-end, still straight - if the level was off and the workpiece was straight, then flipping it would make it read wrong.
Nope. Level was okay. Checked the wall, wall is plumb. Wait a sec - the wallpaper is not straight.
So the notice board went on lined up with the wallpaper, not reality.
The other one was fitting a six metre aluminium pole with a two metre aerial on top to a brand new multi-million pound building. The brackets and pole were absolutely straight and plumb. Got back down off the cherry picker, walked back across the yard to the van, pole looks really squint.
After much upping and downing and to-ing and fro-ing, it became clear that I needed to pack the aerial pole mounting to lean it over by a couple of degrees so it didn't look wrong!
The pole was straight, the multi-million pound brand new high end amazing building was distinctly on the piss with not one truly plumb vertical component anywhere.
It's not the codes, but the physics. The first two years after a building is build, it will change it's geometry until it settles. That happens because building has a significant weight and the earth under the building was unsettled, and now is under a pressure.
Not very noticeable in a light weight houses, but even small brick one-family house will do that.
Building codes account for that, but it's better and significantly cheaper to build that way then to build a totally rigid structure. Rigid is brittle.
I think I'm drawn to programming because the fiddliness is tractable, and fixable.
In which other domain can I:
* introspect the relevant processes/state, step by step
* snapshot/undo
* fix niggles, once and for all, and for everyone; and get their fixes too
* probe and test my inputs and outputs, checking for quality. Get notified if a part changes in a way that breaks me.
And the only tool I need is a commodity general purpose PC.
When I try woodwork, or even electronics, I'm struck by much friction is in even simple tasks: tools, parts, lead time, safety, space, physical effort, cost, ...
The best I could do with woodworking in the end to approximate programming was live with wasting some timber, leave a lot of margin on the main cuts and size all the pieces as a whole.
Woodworking (the more constructive, furniture-making kind), rewards a deliberate, controlled process and it savagely penalizes mistakes. Those lessons transfer well to other disciplines. I’d have been a much better student if I’d learned wood working in high school.
Woodworking was part of my first 3 years of high school, but it was mainly about learning safety and tool usage and not planning, estimating, selecting or purchasing timber.
These days I only want to go to the lumberyard once for a project. Learnt the hard way on my first project that you need to take the time to carefully select the timber - checking straightness, matching grain and also colour before I started. Major hassle and waste of time to have to go back to swap boards.
Sure enough, several had cracks at the ends, knots in poor places, and other things that, had I bought it, would have caused me trouble.
I can be a naive person in that I assume good faith. I would never knowingly sell something poor quality to someone else. I had assumed because I was being sold it, it was okay.
I know about wood quality and I have deliberately bought higher and lower grade wood. But even so, quality varies greatly.
With wood you are up against nature. With software you are up against corporations and comities.
You're up against your wood vendor. Anyone familiar with Home Depot "fresh from the tree" lumber has discovered this.
And also that’s why AI tools create mix reactions. A couple of months ago a post went viral which was really insightful on what I was originally drawn to cs.
I have to point out stairs aren't typically made like this. That's a really complicated way to do it.
I really like this article though. Something that stuck out to me early in my career was a master trim carpenter who told me God is in the Details.
Carpenters constantly battle physics and make dozens of little micro adjustments with the end result being something that is pleasing to the eye that will stand the test of time.
Can't help but think that translates to anything in life no matter what you're doing. Mastering those micro adjustment, whatever your craft may be, takes things to a whole new level.
What do you mean? That's exactly how most residential stairs are built. Two to four stringers with risers and thread boards attached to them.
Granted, they will draw a template on one board and copy it to the others to make the stringers quickly well before mounting anything.
You add a serious amount of un needed complexity by using brackets described.
The rise is typically the only thing you need to know in order to calculate all other dimensions of the stairs.
The main difference between how the author describes the construction is stringers get cut, this description skips that step.
Things like tread depth, riser height can be modified too if needed.
https://news.ycombinator.com/item?id=16184255 - Jan 19, 2018
https://news.ycombinator.com/item?id=22020495 - Jan 11, 2020
https://news.ycombinator.com/item?id=29429385 - Dec 3, 2021
https://news.ycombinator.com/item?id=38407851 - Nov 24, 2023
https://news.ycombinator.com/item?id=43087779 - Feb 21, 2025
https://contraptions.venkateshrao.com/p/truth-in-inconvenien...
There's the Popper observation that any model of reality has zero chance to be true, since our models are finite, yet we're trying to describe a fractal reality. It's amazing how few levels of decomposition we need to go through to get something useful, like the stairs in the article (3 decomposition steps, as compared to thousands). If I were to never interact with reality and rely on pure reason alone, I would expect nothing humans ever do to work.
Abstraction and exploration are unreasonably effective.
"We" (the 8 billion) have made some insanely great abstractions or puzzle pieces to work with. There is just an insane amount of work that goes into even elementary things to get the world to where it works this way.
I thought of this because this morning I was putting a small fence around some plants we want to protect from deer. The fence consisted of 20 sections (bought on Amazon), each about 24 inches wide. Our ground is like rock, and the fence was not that sturdy, so I had to pound a heavy spike into the ground to the depth of the fence posts, then pull the spike out and put each section's legs in, leaving room for the next section's leg to go into the same spike hole. I wanted to be sure I was putting each section in at the right position, lest I end up with a 12 inch gap and have to go back and adjust lots of sections. Long story short, I pretty much succeeded, although when it cools down I may adjust a few sections. But the problem was sort of like the stairs: I wanted an integer number of fence sections, each the same length, to exactly fit around the bushes---just like you want an integer number of vertical steps in a diagonal stair, each of the same (more or less standard) height.
There is an argument to be made for using humans, but I think we need humans to be more capable, more curious, more adaptive. LLMs are far better than the average human, but they are fundamentally inferior to the motivated human working with an LLM to augment themselves at the frontier.
Then we give it to someone else and it fails on their first or second attempt. They simply tried to use it in a way that we did not anticipate. It doesn't mean that we are dumb for not thinking of those possibilities; it just means that we did not think of every one of them.
And it pretty much is most times. For us. But indeed I did run into the "why would they use it like that though" scenario, where it fails. So I have to patch that usecase. At which point I go all "ok now it's really done" until another fringe usecase pops up and so on and so forth. And I did think about how sure I was it was bulletproof, humbling moment.
AI doesn't deal with reality, it deals with tokens. This is why all those vibe-coded harnesses, little more than glue between various text IO interfaces, are several hundreds of thousands of source lines of code.
It's why a SOTA model took 100kSLoK to write a C compiler to compile one specific project.
It's why, when I asked for a simple markdown -> ansi escape codes converter (for terminal output) in Python, SOTA Claude and SOTA ChatGPT both give me +- 150 SLoC when my own LUT-based version came to under 10 lines of code + a LUT.
Reality has a surprising amount of detail, but LLMs don't exist in reality, they exist in a virtual world made up off tokens.
All information gets compressed. Even your own perception of reality gets compressed.
Yes.
> Or just in a virtual world made up of sensory signals?
No, definitely reality. Things affect my thought whether I sense them or not.
I think the more interesting corollary of this article is that if we're living in a simulation, it's an impossibly, improbably detailed one. I really want some compute time on the HPC that's running it.
Okay, lets go with that :-)
I might be living in a virtual reality, correct, I have no way of knowing.
What I do know is that the reality I am in is many thousands of times higher in resolution than the reality of the LLM.
As an analogy, the LLM is seeing a downscaled 32x32 pixel image while I see the original 8k image. Whether there is a larger 1b^2 image that I cannot see is not relevant to the question of whether the LLM can see my reality or not - it can't.
Reality is by definition our physical reality, which is about an infinite number of levels more detailed than the, you know, _virtual_ digital world computers exist in.
Whatever world we construct for LLMs, no matter how detailed we make it, will always be a blocky projection of the real domain onto a virtual one.
It follows then that any insight gained in the virtual world is at best a rough approximation which can be quite useful at times but also utterly faulty on occasion.
How often it is useful vs. wrong is (partially) a function of how complete the real-to-virtual approximation for a given domain.
Certain domains, given their limited degrees of freedom, can be quite accurately modeled, such as a subway map.
But many domains cannot, and it's important to be aware of that inherent limitation in digital models including but not limited to LLM """reasoning"""
I don't know exactly why but I never really understood this argument. Might be some kind of control thing? Because for me it's pretty simple, it's basically free to give access to reality. Just add "sensory organs" as it were. I can argue you can make them perceive reality even better than we (humans) do, just enlarge the audio/video spectrums. Bam...more reality. The whole point of the argument is we're missing information.
Again, I get the need for controlling the environment for what LLM/AI/AGI/whatever will be, but that will always cost more than giving them access to like...reality. Same reason I don't really believe in the whole simulation argument, it's just more expensive all around, loses resolution, let alone control. I don't doubt there will be some people that would indulge in neverending hedonism but not all people. You need to give up control for that.
First, reality is continuous whereas the digital world is discrete.
Second, data in the real world is many orders of magnitude more detailed than what we're able to model with today's computers.
I dunno what you mean by "free". The model is trained on text. To "give" the model sensory organs it would need to be trained on those sensory organs.
Current models can predict text, because that's what the weights represent. Models with sensory organs will need to be trained on the output of those sensory organs.
That sounds close to impossible in the foreseeable future.
Reality is free. You don't have to waste any resources to model it, you just need to capture it.
>The model is trained on text.
See in my previous reply:
>LLM/AI/AGI/whatever will be
LLMs don't even have a sense of time because they work differently to a human brain.
I expect there's a lot of detail that I'm unaware of relating to running a company (planning; risk; legal; ...) that might make a decision foolish to me, but make sense if given more context.
Infinite is a very big claim.
It's just that intuition doesn't scale and a lot of common cases can be handled with models, rules, definitions etc. People continue to be confused that just adding more rules eventually solves reality but it never has anywhere for anything so continuing to believe it will is wild
I am assuming that you put the board at the correct angle on the floor, let it go over the upper entry floor, use a ruler to extend the line of the wall over to the board, trace that, cut it, then reverse the process but this time the part you just cut can go on the floor which will produce the correct angle on the wall?
Contemplating the details of a thing is really satisfying. At times I find myself sitting there and trying to decompose the astonishing amount of work, research, both evolutionary and revolutionary progress that has gone into reaching the current level of something. Buying myself a coffee and stare at the local ferry and acknowledge that someones life's work went into figuring out how to make the paint stick to metal.
Naturally the other point also sticks.. I too often get stuck on the details. :P
- you genuinely learn once your assumptions about how a system works break, you realize it, try differently, validate, get a better model of that system
- your interfaces must remain permissive while providing feedback, namely you provide wiggle room then only once it behaves roughly as expected do you tighten then up
No matter how many data centers are built, it is impossible to accommodate that level of detail.
> As you learn, notice which details actually change how you think.
Lovely article. The older I get the more I appreciate this.
One point worth making: in many cases, after learning to see & appreciate the details, you gain the power to ignore the details that don't matter to you. This can be quite freeing.
But actually in the years since this was written, I do think the world has shifted. Doing things on a computer used to be really hard. Even just installing a framework or getting >python to call the right python on windows. Then install Django and get Django to work with nginx etc. It was just a lot of thankless, frustrating work to get from zero to 1%.
Aside from AI, the tools and packages and culture of computing has gotten better. But AI means you just get all the trivial but difficult stuff for free. And I think a lot of people who would have given up now make it through to see something work and they’ll feel the thrill of building something. It’s just better and easier now.
I visit every couple of days. It's REMARKABLE how fast things get done. One day, there were no walls. The next day, almost all of the walls were in place!
... and yet, at the same time, things take a long amount of time because reality has a surprising amount of detail. I haven't taken into account how much you have to do to frame a house. So incredible amounts of work get done, day after day, but 3/4 of them are things I had no idea needed to get done! Gazing up into the roof, the detail is incredible. The PSL beams, the brackets, the joists, the trusses, just.. EVERYTHING!
I thought the structural engineer's plans had an incredible amount of detail on them, and they do, but they also don't really say anything about _how_ to build the thing. How to put up the walls, how to hold them together temporarily, how to lift beams into place. In what order things can and should be done. That all just takes experience.
It’s always a little disappointing to me when I think I’ve run into something unique but it ends up being user error or something.
Being a founder has a lot of SRE like activities. Fortunately I used to actually like troubleshooting and hence love being a founder but I know a lot of people quit this path because of the "suprising amount of details" in reality!
> you could be intellectually stuck right at this very moment, with the evidence right in front of your face and you just can’t see it.
> Frames are made out of the details that seem important to you. The important details you haven’t noticed are invisible to you, and the details you have noticed seem completely obvious and you see right through them. This all makes makes it difficult to imagine how you could be missing something important.
When you hire someone to work on the stairs for you, you /hope/ they know what they're doing, especially if you don't have the skills yourself to judge their work. Same for an agent.