Bill Hammack of engineerguy explains how medieval engineers designed stone cathedrals using rules of thumb, with no science, mathematics or literacy. He uses it to define the engineering method.
Why Hacker News points people here: HN recommends the series as a thoughtful account of engineering as rule-of-thumb problem solving that predates formal science.
“I encourage everyone to watch this series of videos.”HN comment, 2023
“I encourage everyone to watch this series of videos.”
Series on engineering using rules of thumb
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What everyone is talking past here is that the Babylonians discovered what engineers call a "rule of thumb", and engineering is focused on getting things done using rules of thumb. The best possible rule of thumb is a mathematical proof or a scientific discovery, but it's by no means necessary. . Observing that something always holds and even having a formula for it is not the same thing as having a proof, and the proof is what makes it mathematics and geometry and not "just" engineering. The babylonians had a rule of thumb -- the greeks discovered the theorem -- and more than that, they seem to have invented the mathematical/geometrical proof as a concept, along with formal logic. Without that mental framework, it's hard to say that the babylonians proved anything or had any theorems at all, only collections of rules of thumb. It's quite likely that lots of babylonians sort of independently and intuitively understood _why_ it must be true, but they don't seem to have ever written it down. Not that there's anything wrong with having rules of thumb -- it's a huge achievement to even notice and collect and teach those things, all the stuff around you is built relying on them. I encourage everyone to watch this series of videos. this video
Strongly recommendssublinearJun 2026
“It's too important of a topic to not drive this point home crystal clear by someone who is far more respected than me.”
Engineering improvisation is impressive, not inferior
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As other comments have implied, but not explicitly said, they do their own engineering already with what they have. Since materials can be scarce and inconsistent, much of it is improvised. That in no way diminishes their efforts, results, or knowledge. If anything, that's way more impressive. Lots of engineers in the first world will throw a tantrum if they can't have things exactly their way and probably still make something that doesn't work as well. Entire businesses have shit their pants and gone bankrupt the moment a part is discontinued. Trying to do better than the people who live there is not only arrogant, but it's own variation of Chesterton's Fence. EDIT: I can't help myself and have to post an engineerguy video. It's too important of a topic to not drive this point home crystal clear by someone who is far more respected than me. "Building a Cathedral without Science or Mathematics: The Engineering Method Explained" this video
RecommendsmayormcmattMay 2023
“Truly fascinating.”
Ancient structures built with rules of thumb, not science
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Just yesterday I started watching the video series promoting Bill Hammack's book "The Things We Make" in which he discusses how many incredible ancient structures were built using rules of thumb rather than an actual understanding of the science /math underpinning their strength. Truly fascinating. this video
RecommendsmcpackiehSep 2023
“Bill Hammack aka engineerguy has a good video about this”
Engineering preceded Newtonian physics
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> or building slender towers supported on intricate networks of arches without engineering calculations or even Newtonian physics. In fact engineering solutions came long before Newtonian physics. Bill Hammack aka engineerguy has a good video about this: this video
RecommendsoscareJun 2024
“this excellent video from the 'engineerguy'”
Defines the engineering method as rules of thumb
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Lately I've come to understand the term engineer somewhat differently from this excellent video from the 'engineerguy': this video He defines the Engineering Method as: 'Solving problems using rules of thumb that cause the best change in a poorly understood situation using available resources.' In that sense a Software Engineer would not necessary need to know all the complexities of the complete system to make something work as specified. And I would equate a 'Programmer' more like the Scientist or Mathematician in this case. Funny how there are so many different ways to look at a title.
Cites ittobrJun 2023
“Solving problems using rules of thumb that cause the best change in a poorly understood situation using available resources.”
Definition of the engineering method
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Matches well with the definition of the engineering method provided by Bill Hammack, “the engineer guy” [1]: > Solving problems using rules of thumb that cause the best change in a poorly understood situation using available resources. 1: this video
Cites itempath75Nov 2025
“How do you think all of those engineering organizations came up with those manuals and regulations”
Engineering existed before government manuals
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Government did not invent the discipline of engineering. This is just completely backwards. How do you think all of those engineering organizations came up with those manuals and regulations, were they not doing any engineering until they published a manual? Complete nonsense. this video