To that end, I find a lot of value in thinking with my pen, although I don’t refer back to physical notes very often. The annotation process also helps when it comes time to digitize my thoughts on what I read; it helps me find the important bits again quickly. I like Papermate’s Injoy gel pens and tend to use the pink ones for writing in the margins because it stands out better on the page; green blends in to the text and doesn’t draw my eye when I circle back around to the beginning. Sometimes I underline a useful sentence, or add a symbol next to a paragraph to grab my attention later, like a ! to denote surprise or emphasis.

In an ebook, I can double-tap to highlight the line, and dictate an annotation. With a library book (or something borrowed from a friend), it’s rude to leave trail of exclamation points and arrows all over it, so the notes need somewhere else to go. I’ve discussed before how I make paper notes, and how I organize digital highlights now that AI can do some of the cleanup work. But I’ve been reading more library books lately, and I thought some folks might find it useful to discuss the evolution of my process there.

Why read dead tree books at all?

For one thing, a library is often the only reasonable way to get a book at all; academic texts can run over a hundred dollars, electronic copies don’t always exist, and there’s not much guarantee that it’ll be useful. Sometimes the physical edition is better: a chart-heavy or image-heavy book can be miserable as an ebook, even with all the advances there have been in epub formatting. It’s not always the case, of course; sometimes being able to zoom in on a map is super valuable.

Another reason is that I like modeling reading for my kids; screen-free family reading time feels different when everyone has a physical book. As I’ve written before, paper can send a better social signal than a device, and I don’t like being on electronic devices at soccer practice. I may be reading something wholesome but from a kindergartener’s perspective, even an e-reader is still a screen.

Another constraint I (counterintuitively?) appreciate is the return date. I love owning books because I love having a shelf full of things I can pull down and read whenever I want, or refer back immediately to when it unexpectedly becomes relevant. But the external deadline of needing to return a book is surprisingly handy. A purchased book can sit in my books to read pile1 for a long time. A library book has a return date; if someone else has a hold on it, I can’t keep renewing forever. So that adds a certain pressure to actually read the book. The book therefore gets a little window of attention, which is not always what I want, but it is often what I need. (Don’t ask me how often I sing that song to my kids…)

But when I read a book I need a way to think “out loud” in a way that’s connected to the moment, and if I’m enjoying screen-free reading time, I don’t want to whip out my phone and start dictating commentary.

For a while, my solution was sticky notes. I would write a note, stick it near the passage, then type everything up after I finished. It worked, but the little squares got annoying fast. Processing the book ended with a depressing pile of used paper in the trash. I like having a physical artifact of my thinking, even if the artifact is messy, but post-its in my notebooks drive me nuts and take up space weirdly.

Use a notebook as a detachable margin

So for borrowed books, I like to use a small pocket notebook that opens in portrait mode. Lately that has been the Bullet Journal Pocket, though you may be less anal than I am about number orientation and shape than I am and therefore able to get away with a cheaper option. The vertical two-page format gives me a page that is the same size as a single A5 page, which means I don’t have that itchy “it’s not what I’m used to” feeling in terms of how many words can fit. As a bonus, it usually fits neatly inside my book like a bookmark. It easily sits in one hand or on my knee when I’m walking, too, but that’s more relevant for audiobooks (which I also use this method with, out on walks, but not as often because I generally avoid them).

Anyway, in terms of Bullet Journal methodology, what I end up doing is rapid logging, not an ornate spread. Something like this:

I also like to use my normal #articleSeed and #research style action hashtags, although obviously there’s no automatic indexing of tags when you’re writing on paper.

Anchor every thought to a page

But although there’s no automatic index, it’s important for notes to be grounded to a specific page for manual reference. For the most part, I do not bother with exact quotes; notes work better when you rephrase in your own terms and condense the point. Even if the book itself is leaving my house, each physical note still needs a locator. But I do not paraphrase everything because “re-write everything in your own words” is too time-consuming for serious knowledge work.

Generally speaking, I believe that useful notes need a distinction between claims and evidence. A claim is an idea written in my own words, while evidence is anchored to a source. With evidence, I avoid paraphrasing; I want to avoid a telephone-esque loss of meaning.

But I also don’t want to spend a ton of time taking notes while I’m still reading and absorbing the ideas, so jotting a quick, ephemeral “there’s good evidence for X on page Y” or “page X, person B did Z” note makes sense.

Process the book before you return it

Then, when I’m done reading, I can go back and take photos of the relevant pages (and my own notes) and have a computer extract and organize the information. Readwise has OCR for this, if you have an AI subscription they’re pretty good too, and I’m sure other tools exist.

Needing to return the library book on time is a nice forcing function for actually doing this. And when the reading is fresh, I remember why page 147 annoyed me or what pre-existing notes I thought the chart on page 88 might help with.

My ideal end-of-book workflow looks like this:

1. Type up my notes manually, adding commentary and enriching the thoughts now that I’m done reading and can take the time to expand.

2. Photograph the notebook pages.

3. Photograph the book pages that have exact quotes, charts, maps, images, or confusing passages I need to verify.

4. Make sure every photograph includes the page number.

5. Give the photos to an LLM and ask it to rename the photos.

6. Ask the LLM to create a clean markdown file that pairs notebook notes with quotes extracted from the relevant book-page photos.

7. Ask the LLM to create a separate, organized section that points back to the “source” notes, organized by action items like the articles I wanted to write based on what I learned.

8. Check the output, mostly relying on memory, against the photos while the book is still in my hands.

9. Return the library book once I’m confident the notes are usuable for writing the articles I’ve planned to write.

I use a prompt somewhat along these lines:

Transcribe these notebook pages. Preserve page numbers. Separate my notes from exact quotes. If a note matches up with a photographed book page, pair the note with the relevant source text or image description. Mark anything uncertain with ???. Do not invent missing page numbers. Output clean markdown grouped by page number, with a short “action items” section at the top.

LLMs are good at transcription and cleanup, and they are also perfectly capable of turning p. 119 into p. 191 just like a human could. Sometimes they “helpfully” end up merging two notes that should stay separate, or smoothing away the distinction between my thought and the author’s wording.

Still, they save a lot of time on getting a searchable first pass while my memory can still catch mistakes.

Pairing analog with digital is great

The analog and digital pieces of this workflow are complementary. The little notebook bookmark makes it easier to stay focused on the book. I don’t get interrupted by notifications, my kids don’t try to look at pictures on my phone, and I never get annoyed that I never figured out how to make an iPad whiteboard feel as natural as paper.

Then, digital cleanup integrates useful references and ideas into the rest of my knowledge base. It’s a little more work than just highlighting an ebook or PDF and extracting the annotations directly, but it’s also very satisfying in its own right, and sometimes there’s no good alternative to a physical library book for the stuff I’m trying to learn.

What do you do with library books you can’t write in? Before LLMs I honestly never bothered to type up my photos and PDF scans of handwritten notes, which I am not proud of. So I am very interested in workflows that make physical books easier to integrate into a digital note system because “I would simply always take my time and do it perfectly” is not how I am built, personally.

She wrote “the maintenance of local differences is, after all, a traditional tool of imperial hegemony.” It’s nestled in with a longer argument about Carthaginian power networks, but I came across this quote in one of my Readwise reviews and was startled because it’s one of those things that is trivially true when I think about it — the whole point of an empire is that it encompasses many cultures, that’s what distinguishes it from a kingdom — but also somehow not how I ever thought of empires functioning before.

Put another way: encouraging diversity was a deliberate strategy for maintaining control.

If anything I thought the opposite, because in Against the Grain, James C. Scott argued that small polities with “flimsy political links and weak hierarchies” could resist imperial absorption through their fragmentation — “divide that ye be not ruled.”

How the Neo-Assyrians Ran an Empire

The Neo-Assyrian Empire (roughly 900–600 BCE) is the earliest imperial system with enough surviving records for us to really grasp anything about. There were two zones of Assyrian control: māt Aššur (“the Land of Assur,” directly governed territory) and nīr Aššur (“the Yoke of Assur,” the lighter burden of submission imposed on client states).

Conquered territory could become either a province under a royally appointed governor, or a vassal state with its own local ruler intact. In provinces, governors had no hereditary claim — they served at the king’s pleasure, and eunuchs were preferred because they could not found dynasties. In vassal states, local rulers kept their thrones, passed their offices by inheritance, and ran their own internal affairs. They just had to accept the presence of a royal delegate who represented Assyrian interests in the local government.

At least that’s how I think it worked? Remarkably little material culture of Assyrian origin survives in the provincial archaeological record. We’re going mostly off of written records, and there’s at least one bilingual record where the same official is called “governor” in the Akkadian text and “king” in the Aramaic version. Even so, Babylonia, though dominated by Assyria for most of the eighth and seventh centuries, was never treated as part of Assyria proper. Assyrian kings were crowned separately as “kings of Babylonia” and participated in Babylonian religious festivals.

The Assyrian reputation for terror was well-documented by their own victory monuments and their victims’ accounts, but tho people along the imperial periphery had to pay taxes and supply labor, they were still allowed and expected to just continue worshiping their own gods and speaking their own languages. This helped create a sort of wheel-and-spoke arrangement, because it let them keep conquered regions connected vertically to the Assyrian center, but never horizontally to one another.

A compliant vassal who collected your tribute was cheaper than a garrison... and you don’t need as big a garrison if your enemies don’t have a shared context from which to team up on you!

It was sort of a “mosaic model” in which each region was characterized by different imperial policies. To make it harder for resistance to cohere, they also resettled people. Millions of people were relocated over a couple of centuries. The Assyrians used gardening metaphors in their royal rhetoric, describing deportees as valuable plants transplanted to new soil. Deportees were dispersed and mixed with other populations, which is why the ten tribes of Israel “disappeared” while Judahites deported later by the Babylonians to a single location were able to preserve their collective identity.

Assyrian royal rhetoric used depictions of cultural diversity to demonstrate the truly universal nature of the empire, which is a weird sort of echo of the “diversity is our strength” and “a nation built on immigrants” rhetoric that we have today.

Phoenician Cosmopolitanism as Defense

Meanwhile, the Levantine cities that later became known as “Phoenician” (Tyre, Sidon, Byblos, Arados) were living out the opposite side of this strategy. Quinn argues that these cities never formed a political unit and rarely cooperated with each other. They kept themselves small and cosmopolitan, uncommitted to any particular way of being. It made them difficult to categorize, and difficult to conquer as a bloc.

So the Assyrians dealt with them individually, demanding tribute from “kings of the seacoast” one by one. The cities’ mutual rivalry did the work of imperial control without even needing much in the way of conquest.

Tyre probably benefited from Assyria’s protection and preferential treatment, receiving privileged access to all harbors under Assyrian control.

Quinn observed that “economic and political connectivity is often more important to the ruling class than ethnic difference.”

The Persians who succeeded Assyria as overlords of the Phoenician cities designed their satrapy system so that a satrap, a general, and a secretary each reported separately to the center, preventing any one official from consolidating local power. Local elites were happy to play along as long as the new boss paid lip service to local religious preferences. Under Persian domination, Arados borrowed Syrian visual styles, Byblos used Egyptian ones.

Rome: The Long Experiment

Rome governed the largest empire in Mediterranean history with strikingly few imperial officials. When Rome formed each province, the Senate drew up a lex provinciae, a charter defining territorial limits, the number of towns, and their rights and duties. But the actual business of administration was, wherever possible, left to people who were already doing it. As Bret Devereaux has detailed in his series on Roman provincial administration, “Romans by and large did not interfere with the functioning of local courts or local laws or local customs or local religion.” Mary Beard makes a complementary point in SPQR: “pre-existing local hierarchies were transformed into hierarchies that served Rome.”

Religion worked the same way. The practice of interpretatio romana (identifying foreign gods with Roman equivalents, like Sulis-Minerva at Bath) allowed subject peoples to maintain their religions while linking them loosely to Roman frameworks. In Roman Egypt, emperors appeared in traditional pharaonic regalia on temple reliefs, maintained the nome system of administrative divisions, and permitted Egyptian priesthoods to inscribe them with pharaonic epithets. Rome’s religious flexibility had one consistent limit: monotheists, specifically Jews and Christians who refused to participate in the additive framework.

David Mattingly’s concept of “discrepant identities” captures the full picture: different groups within the empire experienced Roman rule in radically different ways, and any single narrative of “Romanization” obscures this variation.

The Mongol Empire: Thin Layer, Local Everything

The universal layer the Mongol Empire imposed was comparatively thin. Less than a million Mongols ended up governing an empire of perhaps 100 million people across Eurasia.

So like the Romans (and many other governments), they set up a census to enable taxation. The famous postal relay system enabled communication, and imperially appointed overseers called darughachi monitored local rulers without replacing them, much like the Assyrian qepu discussed above). The yasa legal framework was a sort of “federal overlay” rather than replacement. In the Ilkhanate, yarghu tribunals administered Mongol customary law alongside sharia courts, sometimes operating in the same building.

Below the thin crust of the imperial culture, governance varied wildly by region:

Genghis Khan sent administrators from one end of the empire to govern the other. Foreigners on both ends meant neither could easily consolidate local power, although it seems like such cross-posted administrators were the exception, not the rule.

In the Yuan Dynasty, Genghis’ grandson Kublai Khan restored the Chinese Imperial Secretariat but imposed a four-tier ethnic hierarchy that reminded me quite a lot of the colonial-era European powers in Rwanda and India (which we’ll get to later).

Over in Russia, the Golden Horde founded by a different one of Ghenghis’ grandsons (Batu Khan) let local princes kept their thrones after traveling to the capital to receive a patent confirming their right to rule. They collected taxes on the khan’s behalf, and the khans played princes against each other.

It’s a tale as old as empire.

Ottoman Millets: The Most Confusing System

The Ottoman Empire had a formal millet system. This tripped me up but it’s not “millet” as in the grain, it’s from Arabic milla, meaning “religious community” or “confessional group.” They organized non-Muslim subjects into self-governing religious communities: Orthodox Christians under the Ecumenical Patriarch, Armenian Christians under their own hierarchy, Jews under a chief rabbi. Each millet set its own laws, collected its own taxes, and ran its own courts.

Karen Barkey has argued that this diversity management was central to Ottoman longevity. In her chapter “The Ottomans and Diversity” in Culture and Order in World Politics, she describes how the Ottomans managed what she calls “the mobile markers of difference that prevent the formation of horizontal connections that disrupt the imperial structure.” The state dealt only with leaders of each millet, never individual members. Even their taxes were lump sum and levied on entire communities, reinforcing the sense of each group as a separate corporate entity. Groups stayed separate, and their leaders were cool with the arrangement because it backed up their own authority.

That said, I’m not entirely sure she’s right. Apparently the formal millet system as traditionally described had “no grounding in historical reality” in the classical era and the term millet was not widely applied to non-Muslim communities until the nineteenth century. Relevant to my argument, tho, the Ottoman state retroactively organized its subjects into neat confessional boxes, also rather like how Belgium ended up hardening the Hutu and Tutsi Rwandan castes into fixed ethnic categories, or how Britain invented “martial races” in India.

Bear with me as I try to go in chronological order here, but basically, the Ottoman empire was invested in giving their subjects discrete identities, to help keep groups separate enough that they would have a hard time uniting against outside rule.

Then, during the Tanzimat reforms, the Ottomans tried to shift from maintaining differences to promoting “Ottomanism” — equality for all subjects. Sultan Mahmud II declared: “From now on, I do not want to recognize Muslims outside the mosque, Christians outside the church, Jews outside the synagogue.” But as Barkey argues in her Cambridge chapter, without its historical focus on diversity, “the empire lacked incentives to keep increasingly independent peripheries within its orbit, and the imperial galaxy became a cosmos of nations.”

The whole system depended on peripheral elites getting something out of the arrangement: local authority, legal autonomy, a share of the tax base. When the Ottomans switched from managing diversity to imposing uniformity, apparently they removed the incentive structure that kept those elites loyal.

Obviously the actual fall of the Ottomans was multicausal. For one thing, note that I have not mentioned the corruption of the bureaucracy at all, or the Janissaries shifting to be hereditary. For another, I’ve argued in the past that mismanaging locusts was a big part of what brought the Ottomans down, and certainly the Jews were not treated well by the Ottomans, but Aaron Aaronsohn wasn’t exactly an elite, either.

Regardless, I’m not (yet!) an expert on the Ottomans or anything, and I know some of my readers are, so I’m kind of just noticing patterns and hoping someone will push back if I’m misunderstanding the situation or reading the wrong sources.

The Inca Empire: Mandatory Distinctiveness

For an empire with fewer sources to get confused by, I present: the Inca! They also maintained local differences as a pretty extreme version of this deliberate administrative strategy.

Conquered peoples were obligated to maintain distinctive clothing, hairstyles, and head-deformation practices. Each group had to be visually identifiable at a glance. I suppose the idea was that if you can tell at a roadside checkpoint whether someone is group A or group B by what they’re wearing, you don’t need more complicated systems. Local lords were kept in place as intermediaries, collecting tribute and organizing labor in basically the same manner as Assyrian vassals, Persian satraps, and Roman client kings.

Quechua was imposed as the administrative lingua franca, but local languages were tolerated. Like the Assyrians, they had a mitmaq (resettlement) program, although they relocated entire communities to distant provinces, not individual families. Estimates suggest a little over a third of some provincial populations were relocated mitmaqkuna, who were placed above the natives of the region. The Inca ended up creating ethnic patchworks that prevented any single group from dominating a region. The transplanted communities kept their identities and answered to their original kurakas even in their new locations, so the empire could track them through two overlapping systems of control. As far as I can tell this was a deliberate imperial policy intended to reduce the likelihood of rebellion:

The resettlement policy can be reduced to the pursuit of a set of goals. The first was to prevent rebellion in an empire too geographically large to be under military control. This was achieved by breaking up local community groups that may have been particularly likely to rebel and systematically relocating them to distant regions. Often they were resettled in recently conquered towns where the Indigenous peoples spoke a different language, to prevent the uprising of a coherent coalition. The mitmaqkuna were installed as the elite upper class (hanan) within their new communities, where the remaining Indigenous group became the lower class (hurin). The foreigners had the necessary political power and knowledge to dispense traditional Inka ceremonies and imperial order to the Indigenous people of that province, inevitably establishing a social disparity between the mitmaqkuna and the Natives.
[...]
both authors concur that the resettlement system created a healthy conflict (from the imperial perspective) that would focus the people’s attention on local competition, which served to increase working productivity and allowed imperial observation of work capability and diligence for later recruitment . Importantly, the people would be distracted from unifying into greater rebellion against the Inka state.

The same pattern cropping up in the largest pre-Columbian empire is a pretty interesting indicator that this is “convergent evolution” and not just one bad idea about empire spreading down through successor states trapped in a loop (sorry, sorry, I’m still annoyed at Christopher Beckworth’s The Scythian Empire claims that since the Chinese had governors they had to be Scythian, it was a pre-Mongol Scythian invention, or something).

Colonial Innovations in Division

Anyway to get us a bit closer to the modern day, European colonial powers spent a lot of time defining group identities to facilitate governance too.

For example, the system of “indirect rule” in Northern Nigeria preserved existing political institutions and incorporated them into the colonial administrative system. Local rulers kept their courts and their treasuries. In southeastern Nigeria, where the Igbo had no centralized authority, Lugard simply manufactured his own chiefs — the notorious “warrant chiefs” who lacked any traditional legitimacy. The bifurcated state helped keep resistance ethnically and locally defined, so it didn’t end up coalescing into a single movement.

After the 1857 Indian Revolt, during which Hindus and Muslims had fought side by side against British rule, Lord Elphinstone reportedly declared: “Divide et impera was an old Roman maxim, and it shall be ours.” The British introduced separate electorates where Muslims voted only for Muslims and Hindus for Hindus. Politicians now had to appeal to narrow religious identities, because the system rewarded communal loyalty.

The military was no different: the British restructured the Indian Army to recruit selectively from Sikhs, Gurkhas, and Punjabi Muslims while excluding communities that had rebelled. Nicholas Dirks argues in (the blurb of, I haven’t read it yet) Castes of Mind that “under British domination caste did become a single term capable of naming and above all subsuming India’s diverse forms of social identity and organization.” The census hardened what had been fluid social categories into fixed administrative ones, which is particularly ironic given how strongly “castes” are associated with India.

Tbh it reminded me of how pizza is an American invention but people associate it with mainland Italy, and now Italy is where people go to get the “best” pizza even though tomatoes come from ~Mexico.

The Spanish colonial casta system constructed an elaborate classification hierarchy combining religious, racial, and genealogical categories. Spain maintained hegemony in a multiethnic society “without overt force or coercion” through patron-client networks that “promoted divisions among the poor.” When plebeian classes briefly overcame racial divisions in the 1692 Mexico City riot, the colonial state exposed fissures among the ethnically mixed poor and survived. The system gave every group someone other than the government to dislike.

The Soviet Union tried yet another variation. The policy of korenizatsiya (indigenization) in the 1920s created territorial homelands for every officially recognized ethnic group, each with its own constitution, territory, and cultural institutions. Terry Martin has a whole book about this called “Affirmative Action Empire” that I have not read but want to. The thesis is (aka the blurb says) that the Soviet government “was the first of the old European multiethnic states to confront the rising tide of nationalism and respond by systematically promoting the national consciousness of its ethnic minorities.”

When the USSR collapsed in 1991, it for the most part dissolved along the exact national administrative lines the Bolsheviks had drawn… not the historic borders of the 1800s.

The Hungarian-appointed governor of Croatia in the 1880s and 1890s did basically the same thing when he granted the Serbian minority within Croatia preferential treatment. He offered them posts, patronage, and a degree of cultural recognition that Croats were denied. Rebecca West talks about this a lot in her doorstopper (and very interesting, and I have been working our way through it for like a year now!) travelogue Black Lamb and Grey Falcon, which I’m given to understand is remarkably accurate given her background as, well, a lady who visited a couple of times and read some books. Croat resentment focused on the Serbs, not the capital, which frustrated West to no end as she was friendly with Croats and Serbs and really wanted the Balkans to do better. Instead, neither group organized against the empire because each was too busy watching what the other one got.

To hear her tell it, it’s an insane miracle that a couple of low-level guys managed to kill Franz Ferdinand.

On the End of Hegemony

When this works, peripheries interact almost exclusively through the core, never directly with each other. The center’s power is protected by maintaining “structural holes” between governed groups. Again, picture a wheel with spokes.

Maintaining or imposing differences seems to work because it is cheap and leverages existing administrative capacity. It throws a spike in the wheel of the most dangerous thing an empire can face: unified resistance. If your A subjects are focused on being mad at your B subjects, neither group is teaming against you. If each province has its own laws and customs and identity, there is no “provincial” identity to rally around. Identity matters!

I’m not entirely sure if this works until it doesn’t (and then the empire tries to switch strategies), or if it works until someone decides to try to consolidate (and then the empire falls because united, the periphery is stronger than the center).

After conquering the Warring States in 221 BCE, Qin Shi Huang imposed comprehensive standardization: unified weights, measures, currency, writing, legal codes, even road widths and axle gauges. The result was the shortest dynasty in imperial Chinese history, lasting only 14 years. The Han ended up moderating Qin uniformity, though the resulting hybrid system brought its own rebellions.

Under Akbar, the Mughal Empire’s mansabdari system organized diverse elites into a unified hierarchy based on rank alone, regardless of origin. Then, Aurangzeb reimposed the jizya tax on non-Muslims and discontinued syncretic court rituals, Jat, Sikh, Maratha, and Rajput rebellions escalated and the empire began its long disintegration. Would they have been better off not unifying? I don’t know. Maybe the whole thing was inevitable.

Pre-revolutionary France was so fragmented that Voltaire joked you could “change legal systems as often as you change horses.” I’m still working my way slowly through Peasants into Frenchmen about the modernization of rural France, but my friends ( and ) swear by it as a fascinating account of how the French did not have anything resembling a unified identity despite how Napoleon came in with the Code Civil, uniform departments, and standardized administration. I get the sense that Napoleon built an “inner empire” where uniformity built on existing traditions, but the “outer empire” never held precisely because they didn’t do the tried-and-true method of imposing a thin rulership layer on diverse local rule. Not sure how true that is, though, almost everything I know about the French comes from the fictional Honor Harrington series modeled on a British admiral.

On Legacy

I almost hesitated to write this because of how fraught this issue is, but I do think it’s genuinely interesting to contrast the different perspectives that people like James C. Scott and Josephine Quinn bring to the question of diversity. On the one hand, there’s the old Aesop “united we stand, divided we fall” and Matthew 12:25 “And Jesus knew their thoughts, and said unto them, Every kingdom divided against itself is brought to desolation; and every city or house divided against itself shall not stand.”

Abraham Lincoln once gave a speech along those lines, too.

But if I get away from the mythmaking and the just-so stories for a moment, I think Quinn is right that diversity can be a tool of control just as easily as it can be a source of protection, and that a house divided itself does, in fact, stand.

Whether that’s good or not depends on whether or not you’re the one trying to maintain the empire and the peace it brings, or the one trying to break it to have more freedom.

The book focuses on the period of time between Robert E. Lee getting sent to put down John Brown’s raid in October 1859 and closes with a some poor bastard after the war trying to sort out which squatters got to keep which houses. In between, Harpers Ferry changed hands either eight or fourteen times, depending on how you count^[1]. There was an utterly ridiculous number of different commanders. The bridges got blown up or burned and rebuilt almost ten separate times, and we all know how I feel about bridges failing!

The prewar ballot total of roughly 1,800 collapsed to 250 votes during the war, only one of which was cast by “a staunch rebel.”

Harpers Ferry’s staunchest rebels, the Floyd Guards (aka Company K of the 2nd Virginia and eventually part of the Stonewall Brigade), mustered there in April 1861. Most of them never got to go home; the ones that made it back returned to a town almost unrecognizably damaged. It never regained its former glory.

I obviously love Harpers Ferry (more for the hiking than the history, admittedly), but the book is pretty good even if you don’t care that much about the town itself. Hearn does a good job of balancing interesting battle stories with remembering the civilians and the “little ironies” of war. Lee, McClellan, and Jackson all turn up, but the focus stays on the town and its people.

Townsfolk like Joseph Barry, Jessie Johnson, eight-year-old Annie Marmion, and Father Costello saw it through, from beginning to end, and from their perspective, no town suffered more than Harpers Ferry.

A Quick Overview

If you’re not super familiar with the Civil War (and I was not; so many people make it a core interest that it sorta turned me off trying to learn about it too, same as Rome), the story of Harpers Ferry during the Civil War goes something like this:

October 1859: John Brown heads over to the federal armory hoping to use the weapons to fuel a slave uprising, although he had pikes brought in for the freed slaves because he didn’t trust them with guns. Robert E. Lee, summoned from Arlington on short notice, misses his train and is so rushed he shows up in civilian clothes to reclaim the arsenal and arrest the raiders. There’s a trial, with a chronically drunk prosector and a few shenanigans, and then some hangings.

April 1861: Virginia seceded, the federal garrison under Lieutenant Roger Jones evacuated and tried to blow up the armory before leaving. “Tried.” His men laid powder and lit the fuses... but the civilian armory workers (most of them Northerners, but partial to their jobs and aware that an intact armory meant a future paycheck) ran along behind the soldiers wetting the powder. There’s something cartoonish about two columns of men working alongside each other at total cross-purposes, one laying fuse and the other dousing it. Most of the buildings burned anyway, of course.

Then Stonewall (formerly professor) Jackson arrived a week later and spent the spring methodically stripping the place^[2], boxing up rifle-works machinery and shipping it to Richmond, burning what he couldn’t take, and dropping the railroad and Winchester & Potomac bridges into the rivers. The town emptiesdo f jobs, and the men who built rifles for a living mostly followed the jobs south regardless of politics. I got the impression that those working-class guys treated government more like weather than something to participate in; something to adapt to, not control.

Then the merry-go-round started. Geary garrisons in fall 1861, Banks in spring 1862. Saxton repulses Jackson on May 30, 1862, and gets a Medal of Honor for it three decades later... he’s maybe the only guy who walks out of Harpers Ferry covered in glory instead of shame.

Corporal Miles, fresh off of a court-martial trial for being drunk during a critical battle, takes over in June and surrenders the entire garrison a couple of months later despite basically everybody begging him not to. The book devoted a ton of time to Miles’ stubborn, drunken incompetence, although the folks on r/CIVILWAR seem to think he was more dealt a bad hand than anything. But he still spent his time systematically ignoring competent reconnaissance from his own scouts, including a cavalry officer named Davis who threatened to disobey orders rather than surrender his horses to the enemy. Colonel Downey of the 3rd Maryland gave sworn testimony at the postwar Board of Inquiry that Miles, on the morning of the Maryland Heights retreat, could not remember which of his own colonels he was supposed to be giving an order to.

Hewitt on Maryland Heights, the officer who actually relayed the retreat order, was issuing it from partway down the mountain where he could not see the line he was telling them to fall back from, citing an order from Miles he later admitted “may not have applied to the moment in question.” Gah!

It was so bad that historian Paul R. Teetor (his 1982 book A Matter of Hours: Treason at Harpers Ferry is on my list; let me know if you’ve read it or would like to!) apparently argues Miles deliberately moved up the surrender schedule so he could surrender before McClellan — who was close, not that Miles bothered to tell anyone else — got there.

Anyway, after Antietam, McClellan reoccupied the town, and some guy named Cyrus B. Comstock submitted a lengthy proposal to turn the place into an impregnable fort that mostly doesn’t get built. One of these days I want to see if I can find a copy of the proposal. Mosby’s Raiders kicked off a daring raid against Cole’s Maryland Cavalry on Loudoun Heights and blew the surprise by opening fire too early. Sheridan makes Harpers Ferry his Middle Military District headquarters in August 1864. The town gets shelled, which basically only manages to kill civilians. The war ends.

Then in October 1870, the Potomac and Shenandoah both rise and take out the Winchester & Potomac bridge and most of the rebuilt buildings on Virginius Island. The B&O bridge, set on stone piers framed in heavy iron, was the one structure that survived.

Honestly I think the most important (as opposed to interesting; there were a lot of great stories I’m eliding here) part of the book was the railroad bridges.

The bridges kept going down because they were corporate infrastructure

The B&O is actually the reason the federal response to John Brown’s raid started early enough to matter at all. The conductor of the eastbound train, Phelps, came into Baltimore with a wild story about armed men holding the armory at gunpoint. William Prescott Smith, the B&O’s master of transportation, whose job it was to decide whether to believe his own conductors, blew him off. The patrol night watchman, Patrick Higgins, had been struck a glancing rifle wound on the head, and his story was dismissed at the armory clerk’s office as drunken talk about a strike.

The first man to actually take the report seriously was John W. Garrett, president of the B&O. Garrett wired Washington, and the federal government took him seriously; without that, October 17 and the whole Civil War would have played out very differently. Garrett held no federal appointment and no military rank, but then as now, private enterprise played a key role in America’s warfighting capacity.

Indeed, despite Brown’s raid and the early efforts to destroy and loot it, the arsenal wasn’t why Harpers Ferry was so strategically important. It had long since been overshadowed by the much more competently-run Springfield. Harpers Ferry during the Civil War was mostly a supply depot and a key reason was the fact that it was one of the best places to cross the Shenandoah and Potomac Rivers heading west toward Ohio.

Harpers Ferry was also, for most of the war, a critically important corporate asset, and the Union needed the railroads if they were going to win the war. For the first couple of months, the railroads tried to remain neutral, actually, but as far as I can tell, there was no way for that to last.

The B&O Railroad ran east-west through the town across a long covered bridge over the Potomac, and that bridge was the only practical east-west supply line west of Washington, D.C. The Winchester & Potomac spur ran south out of the same junction toward the Valley. Whoever controlled the junction controlled rail movement of grain, troops, and weapons between the Atlantic seaboard and the west.

The B&O bridge across the Potomac was destroyed and rebuilt several times, and the Winchester & Potomac spur went down nearly as often. Both sides destroyed the bridges at various points, and of course the railroad presidents wanted them rebuilt (and defended!) so the trains could get through. By 1864 the railroad’s chief engineer was, in effect, on call to put a bridge across the Potomac roughly twice a year. Later in the war, the B&O literally writes letters to the Union officer in charge of Harpers Ferry begging him not to destroy the “costly and difficult” structure, which the railroad had by that point rebuilt at its own expense more times than I feel like going back to check.

Of course, it wasn’t just the armies destroying the bridges...

What Jackson failed to accomplish with his night attack on May 30, the flooded Potomac took care of on the night of June 5 by washing out the rebuilt Baltimore and Ohio bridge and sweeping away a trestle on the Shenandoah serving the Winchester spur.

Floods kept wiping out the bridges even after the war was over: lower town sits inside a V where the Shenandoah meets the Potomac, and the V fills up pretty easily. But during the war, it’s kinda worse, because once the spans are out and the river is running high, soldiers on either side of either river can end up stranded from their wagons and their food. Saxton repulsed Jackson partly because of this; the May 1862 Confederate probe collapsed when the pontoon bridge washed away on its own.

At some point I need to figure out why levees have never been built at Harpers Ferry? The town floods this much, has flooded this much for at least a century and a half of recorded history, and still floods this much (the most recent serious flood was 2018 and there have been multiple high-water events since). Is it the cost? The topography (the place really is a V between two fast-moving rivers and maybe you can’t put a levee there)? How do levees even work? I’ve only seen them on the Mississippi now that I think about it...

Why Harpers Ferry is so hard to defend

Speaking of the terrain of Harpers Ferry, water isn’t the only thing it’s hard to protect against.

Peter Stephens, who built the very first home below Jefferson’s Rock, called his own settlement “The Hole.” About a hundred years later, Hearn writes, “thousands of soldiers would write home to loved ones that the dirty little town of Harpers Ferry was nothing but a ‘godforsaken, stinking hole.’ And to any military man with an ounce of tactical sense, a hole it was.”

Three high points surround Harpers Ferry, and because the industries needed the river for power, the town sits in the bowl below all three of them.

Maryland Heights and Loudon Heights both sharply rise over a thousand feet — seriously the cliffs are nearly shear, which is handy for the falcons, which are making a comeback — directly across the river from the town. Whoever holds the heights has artillery pointed straight down into the lower town. To hold these heights, you have to put your troops across a river from your supply base, and if that river floods or the pontoon bridge goes out (and it will, see above), your soldiers up there are stranded.

Bolivar Heights is the only piece of high ground on the same side of the rivers as the town itself. It’s the gentle land approach west of Harpers Ferry, with some chill trails I need to check out at some point. Bolivar Heights is how any wagon-supported enemy is going to come, so if you don’t hold Bolivar Heights, the town is cut off from the main road east.

So to defend Harpers Ferry, you have to hold three hills simultaneously, two of them across rivers, all of which require their own garrisons and their own supply, in a town whose bridges are getting wiped out basically all the time.

When Jackson attacked in September 1862, he sent McLaws to Maryland Heights, Walker to Loudoun Heights, and took Bolivar Heights himself, in three converging columns. It’s just brutally complex to deal with compared to something like “find the enemy, march your guys to a field, line up and shoot.” And even that “relatively simple” stuff was really hard in the fog of war, even with telegraphs! Caesar, one of the most brilliant military commanders of his time, got lost going off-road on his way to crossing the Rhine in his own metaphorical back yard, and he wasn’t even under fire!

For an example of the kind of craziness I mean, one retreat from Maryland Heights went through three couriers, none of whom could produce a written order, off a position that was holding when the order arrived. Downey, hearing the order, replied, “For God’s sake, don’t fall back; we must hold this position.” They fell back anyway, and the whole defensive position folded the next day.

Pigs ate a guy

So those are some of the bits about the town infrastructure and strategic value. But honestly my favorite parts of the book were the weird details and human stories that weren’t super important to the history of the town but made the town feel more real.

If you’ve ever read or watched Hannibal (great book, terrible movie) you may remember that a critical plot point is that you shouldn’t trust guys that own a bunch of hogs because they’re maybe serial killers. While I have absolutely never doubted that pigs will eat people, Six Years of Hell was the first time I ever came across a real-life example.

It started with a sharpshooter hidden in a house at the foot of High Street during Brown’s raid of the armory. He loaded his rifle with a rail spike — apparently they’re roughly the same size? I’m shaky on the details — and shot raider Dangerfield Newby in the head. After the shot, Hearn goes on for a full paragraph about what the townspeople did to the body, and I’m going to quote the whole thing because paraphrase won’t do it justice:

Townsfolk dragged the body into an alley and took their revenge. They cut off his genitals, slit his throat, and rammed sticks into his wounds. Another knife wielder trimmed off Newby’s ears and put them in his pocket. When the crowd tired of their sport, they pushed the remains into a gutter, and the town’s hogs finished off the body. A few spectators temporarily lost their appetite for pork.

I can’t really blame them...

Cemetaries & Churches

One of Hearn’s best sources is Joseph Barry’s The Strange Story of Harper’s Ferry which was published in 1903, so it’s public domain and available online. After Patterson’s Union army occupied Harpers Ferry in the summer of 1861 and then withdrew at the end of their three-month enlistment, Barry says some of Patterson’s men carried off a tombstone from the Methodist cemetery. I decided to share the primary source here because it’s more unfiltered:

What they wanted with it he will not venture to guess, but a regard for the truth of history compels him to relate the fact. It may have been that some company cook wanted it for a hearth-stone or it may have been that some pious warrior desired to set it up in his tent as an aid to his devotions, but certain it is that six or eight soldiers of this army were seen by many of the citizens conveying it between them from the cemetery to their bivouac in the armory yard.

Part of the other reason for sharing Barry directly is that there were a couple of places where I think Hearn was just wrong. For example, he says Father Michael Costello, the Catholic priest at St. Peter’s, billeted Confederate officers in his home, but when I researched this I ended up pretty convinced this is a myth; I don’t think the church housed the priest, even. Costello was the only priest to stick it out, though, and the NPS agrees that his efforts to signal neutrality probably saved the church:

Costello is noted for flying a Union Jack flag atop of St. Peter’s to express neutrality. This action is attributed with saving the church from being a target during the many bombardments the town. He held services and administered sacraments as much as possible during wartime along with allowing the church to be used as a hospital.

As far as I know, the Catholic Church itself had a strict position of neutrality in the American Civil War.

By 1860, there was an estimated 4.5 million Catholics in the United States, nearly one-sixth of the American population. Half of this Catholic population came from two decades of massive Irish immigration. [...] while Protestant denominations split along sectional lines and theological interpretations of slavery, even to the point of advocating war, the Catholic Church seemed maddeningly united and suspiciously neutral during the secession crisis.

Don’t Volunteer To Do Hard Things If You Can’t Follow Through

For all his flaws and flamboyance, no one denies that John Brown had the courage of his convictions. Even Miles, who was by all accounts an incompetet jackass, wasn’t a coward. But some of the guys in this story... kinda were, in ways that I sympathized with very deeply. So I’ll end on the note of the two stories that I’m mostly likely to remember when making decisions:

Alfred Balbour was sent to the Virginia secession convention as a pro-Union delegate by a Jefferson County electorate that wanted him to keep them out of the war. He got teased about being a Union stooge, got pressured by lobbyists, got rattled, and ended up resigning his armory position and helping the former governor of Virginia unilaterally seize the federal armory at Harpers Ferry. Barry talked to him about it and later Balbour came back and admitted Barry had been right to advise him to hold firm. Too late, oops.

Herr the miller does basically the same thing, just less formal and over less tiem. Herr literally volunteered — again: volunteered, unprompted! — to ride to Washington and beg for federal reinforcements when the Virginia troops first began menacing Harpers Ferry in April 1861. He got halfway and panicked that his anti-Union neighbors would ruin his business if word got out, and turned around. Someone else might have gone, man!

Anyway, it was a nice reminder that if you don’t want to risk being involved in something, you should keep your mouth shut and not volunteer. This is hard! I like to volunteer to help people when I know that I have the necessary skills. But I do not always have the necessary time, or risk appetite, to actually help with those projects, and sometimes the hardest thing in the world is to say nothing or “no, I’m sorry, I can’t commit to that.”

Not exactly what I went into the book looking for a reminder of, but hey. It was a good book in a lot of respects, with a ton of interesting stories that I could not include here. You should absolutely double-check names and dates and anecdotes because Hearn does sometimes get things wrong, but for the most part they seemed like clerical errors or honest mistakes caused by writing in a pre-internet era where it was much harder to get accurate context for stories that started out largely anecdotal to begin with.

Let me know if you decide to read it, either here or on the newly opened Harpers Ferry subreddit, where I’ve been posting photos and history snippets lately.

1. I’ve previously written that Harpers Ferry changed hands eight times during the war, which is what’s on the NPS signs. Hearn’s appendix gets to fourteen by counting command transfers within the same garrison and brief raid-and-withdraw sequences that didn’t last long enough for a new commander to settle in. Both numbers are legit, they’re just measuring slightly different things.↩︎

2. Hearn mentions almost in passing that Jackson gave most of his coat buttons away to admiring Maryland ladies during the campaigns of 1862 as souvenirs. I have no idea how normal this was in either the Civil War or in older wars, but the idea of fussy Stonewall, who once held up an urgent deployment in order to be pedantically on time, slowly unbuttoning his coat all summer, one button per fan, is a really weird mental image. I imagine him as sort of weirdly flustered by all the fluttering women. ↩︎

Productivity

• Brian Schrader wrote about his system for taking better notes by hand, which combines digital bookmarking tools with paper notebooks. He writes only on right-hand pages in pen, leaving the left side for penciled follow-up thoughts, and maintains separate notebooks by topic. It’s a nice practical walkthrough for anyone who’s tried to go back to handwriting but struggled with the lack of space for later editing.

• I liked ’s article about how presenteeism is a hidden productivity killer, covering how the pressure to look busy persists even in remote work. She breaks presentees into four types based on health and performance, and traces the triggers back to things like workaholism, job insecurity, and performance-based self-esteem.

• Cedric Chin had a great piece about how experts sensemake, which covers the Data-Frame Theory developed from US military research. The core idea is that experts and novices use the same cognitive process — the difference is that experts have richer mental models, so they build better frames faster and recover quicker when their initial read is wrong. It’s a practical piece if you’re interested in how to actually get better at reading ambiguous situations rather than just telling yourself to “be more open-minded.”

AI

• claims that AI is an infinite midwit, or rather that it’s great at problems with clear right answers but is fundamentally unable to do the squishy, subjective work that makes creative output worth reading. Personally, I find AI research aggregation really helpful and AI writing tics so annoying that it’s messing up my ability to read old books that sprinkle similar phrases in, personally.

• wrote a walkthrough on using OpenClaw as an engineering leader, and says that hallucinations are the main problem and you need strong technical judgment to tell when the tool is confidently wrong. Just like calculators can’t substitute for developing good “math sense” (so you can identify a flub when you input 4+4 and get 10 because you hit 6 instead...), AI is not a substitute for developing domain knowledge. It’s still helpful tho.

• ’s Just do the reading similarly points out that summaries, explainers, and lectures can help, but at some point the only way to know what a book or paper says is to sit down with the thing itself.

• breaks research into two modes — verification (checking a specific claim) and exploration (building understanding from scratch) — in a deep dive on what “do your own research” actually means and what its history is now “so loaded that hearing it now tends to shut conversations down rather than open them up.”

• wrote As We May Work, about what non-technical knowledge workers (like me!) need to understand about the next wave of AI.

• ’s This Week in Putting AI to Work is another practical survey of how people are actually using AI instead of arguing about it in the abstract.

• This guy tried to get LLMs to predict how his coffee experiments would turn out and they did... not do so great. BTW I also enjoyed this ‘brief’ history of instant coffee.

• The Observer profiled the Catholic priest who helped write Anthropic’s AI ethics code. I have a soft spot for rationalist-adjacent Catholics and ethicists actually being useful, so it was a fun read.

• ’s “two AIs in a trench coat” reviewed Die With Zero, and it’s interesting not just because it’s a early retirement adjacent book that people seem to like, but because it uses AI to turn “it could have been a blog post” into longform book review blog posts in the style of Jane Psmith, Scott Alexander, and, well, me.

Media

• On that note, the ever-delightful reviewed Thomas Asbridge’s The Greatest Knight, about William Marshal and the messy business of surviving five English kings. Seriously I want to be just like her when I grow up (ignore the fact that we’re roughly the same age).

• Nathan Goldwag wrote a pretty compelling argument that the Star Kingdom of Manticore’s constitutional monarchy is structurally closer to an aristocratic oligarchy and doesn’t really make sense throughout the course of the series. It’s a thought-provoking piece if you like thinking about how fictional worldbuilding holds up under political science scrutiny and like using fiction to think about economics. I learned most of what I know about the French Revolution and Napoleanic Wars from the Honor Harrington series so I found it really helpful for mapping that onto reality.

• I loved the discussion over on Big iff True’s magic train theory of economics. It’s also about economics in the context of fiction, this time the movie Snowpiercer, in which “the economy is almost literally a black box—a magic, static engine, out of sight and mind. In reality, the essence of economic prosperity is cooperation. Human flourishing depends on us working together: sharing ideas, dovetailing labor, coordinating on language and technology, reallocating resources, refraining from violence.” It was a very insightful critique from but the comments had some interesting pushback on the thesis.

• I saw Project Hail Mary with my husband and liked it a lot. I liked the book a little better because we get more of Ryland’s internal problem-solving, but the physical humor only works on screen, so I think the two versions complement each other nicely. wrote about how the movie handles positive masculinity, and said he thinks science fiction is in good hands because of this movie.

• Every so often I am reminded that I live in an extremely weird reading bubble. Pew found that Americans still prefer print books over digital or audio versions, and very few are in book clubs.

• For May in my book club, we are reading Joe Studwell’s How Africa Works. He also wrote How Asia Works, but the book about Africa was published this year after like ten years of researching in Africa because fans of his Asia book kept asking about how his theories apply to Africa. It seems reasonably even-handed so far, and fits neatly with the development and institutions threads running through a lot of the stuff I read last month.

• In April, we read Hard Landing: The Epic Contest for Power and Profits That Plunged the Airlines into Chaos by Thomas Petzinger Jr. It was extremely well-written, his predictions hold up, and I learned a ton about the history of airlines in America. It was particularly timely given the whole “Who Killed Spirit Airlines” discourse; Petzinger wrote this back in 2010 but there were several merger stories and several stories about past generations of budget airlines trying to compete. It also had a really detailed look into hub economics, legislative and judicial impacts on airlines, and how the airlines drove a lot of early computer development. The bits about Southwest Airlines were my favorite, because Herb Kelleher was a hell of a guy and Petzinger handled the biographical aspects really well. Seriously great book, highly recommended.

• I also read the Two Income Trap by Elizabeth Warren and her daughter. I don’t really have much to add to the discourse that Scott Alexander didn’t say back in 2014, but I’m glad I read it and my most common reaction to the book was “ok if you think thing A in context B, why not apply it in context C…?” It didn’t really move the needle on my decision to leave my job, but it came up a lot in discussion and I felt sort of obligated to actually read it myself.

• ’s short reviews for April 2026 covered Peasants into Frenchmen, Children of the Night, A Wrinkle in Time, and Frankenstein. I still have not gotten to Peasants into Frenchmen (although I own it), but enough people I trust have found it useful that I still feel comfortable recommending it via affiliate link. Evan says “I’m not going to recommend [Frankenstein] for a modern audience for more than historical interest” but I disagree... I read Frankenstein back in early college, mostly because one of my neighbors needed help writing a book review of it or he was going to fail to graduate high school, and I found it a lot more readable than most of the stuff I’d been assigned. It’s a hell of a lot better than Dickens, imo!

History

• Bret Devereaux wrote about reconstructing the Roman pectoral, arguing that the standard reconstruction of the bronze chest plate described by Polybius is probably wrong — it was likely a complex seven-part harness rather than a simple square plate. One of my favorite niche historians, Sean Manning, followed up with a related piece on whether Roman-era metalworkers had trip hammers and rolling mills to produce that kind of armor at scale. Together they’re a nice window into how much we still don’t know about the practicalities of ancient military equipment.

• of Ottoman Encounters pushed back on the Ottoman decline narrative, arguing that the familiar rise-golden-age-decline-collapse arc cherry-picks evidence.

• r/AskHistorians had a deep dive on twentieth-century vending machines that touches on quite a lot of organized crime mechanics, particularly how vending machines, jukeboxes, pinball machines, coin-operated laundromats and the like allowed for money laundering. Fans of Matt Levine and Patrick McKenzie might enjoy this one.

• also wrote a great history of how West Virginia came to be, which gets into interesting Civil War era history and legal theory I did not know.

• Archaeologists found a copy of Homer’s Iliad inside the stomach of an ancient Egyptian mummy, which is a good reminder that ancient texts survive for weird reasons and we really only have the tip of the iceberg of what they actually produced.

• wrote about how China went capitalist, and looked at post-Mao reforms and the way capitalism can help countries climb out of poverty. It pairs neatly with the themes I am seeing in Joe Studwell’s How Asia Works and How Africa Works (affiliate links).

• is a Catholic economist (and also my friend). My favorite pieces this month were about whether the Roberts Court is more info protecting free speech than its predecessors, and an explanation of Lentan fasting. It’s always nice to see other people rotating through their interests instead of nicheing down and hyperspecializing forever, particularly people with PhDs :P

Sociology

• asked whether cost disease is one reason America has become more socially isolated. I don’t know if I buy the whole causal chain, but the core idea is plausible: if every service-heavy activity gets more expensive because the workers would otherwise go into a different field, the places where people used to spend time together get harder to afford.

• On the flip side, wrote about how funerals keep Africa poor, arguing that lavish funeral spending is a major driver of household poverty across the continent. Social pressure to match the deceased’s perceived status drives people to borrow at 30%+ monthly interest rather than hold a modest service. It’s a useful piece if you care about how cultural norms can trap people economically in ways that are hard to legislate around. This look at how strong family ties can be bad for society and development is a direct response to Oks’ piece, with lots of great graphs.

• On similar note, wrote about suicide by culture, looking at how 19th-century Protestants (but not Catholics) in parts of Slovakia (Novohrad, Hont, Malohont, Gemer) adopted a single-child cultural norm to avoid splitting family property. It’s an eerie echo of modern fertility debates and a genuinely fascinating deep dive.

• Here’s a paper on public-goods games that found that punishment can improve welfare under the right conditions. I’m not gonna get deep into the weeds on politics and parenting here, but I found it thought-provoking and highly relevant to, well, politics and parenting and education.

• It’s kinda weird to think of it this way but... this paper on the population structure of the Amish looks at how a rapidly growing ethnic religion maintains distinct population patterns in North America.

Science

• There’s an eight-year “civil war” raging among the Ngogo chimpanzees at Uganda’s Kibale National Park, where a once close-knit community has ended up killing a bunch of infants. The Hacker News thread has much more background on what might have kicked it off, but it was a reminder that ants and humans are not the only animals to wage war.

• had a nice deep dive on North American mushrooms, digging into why U.S. mushroom production has declined while Canadian production has grown and much of that production gets exported south. The answer has to do with labor pipeline rules and quirks of how mushrooms are a year-round crop.

• Scott Travers wrote about why about 10% of humans (like my son!) are left-handed. Basically,shared handedness makes social learning, tool use, and coordination easier, but left-handedness persists because rarity can be an advantage in certain competitive situations (think baseball or fencing).

• Jul Quanouai wrote a super interesting and useful deep dive on Tylenol vs. ibuprofen, how they work, and when you should use which. I was always a little nervous about the “Tylenol overdoses can wreck your liver” thing so I found it really useful.

• Turns out The ancestors of wild wheat, barley, and rye were much less widespread in the Middle East 12,000 years ago than scholars had assumed.

• I don’t drink caffeine anymore, but I know a lot of people who do, and this piece on how the effects of caffeine last longer than the usual five-hour-half-life folk model suggests was interesting even if not directly relevant to me.

• PSA: children who say hand dryers hurt their ears are correct. My oldest hated hair dryers and my youngest hates traffic, and honestly these are reasonable things to hate given how their little ears work.

• Really exciting science is still happening: human trials have begun for a drug that could let adults regrow teeth, and there’s gene therapy trial where one injection restored hearing in weeks. I am trying not to overstate early biomedical work, but teeth and hearing are both pretty cheerful categories of progress.

• On the more “crap!” side, apparently a marine animal virus may be impacting human eyes now.

Infrastructure

• This utterly crazy story about how GoDaddy gave a longstanding major business domain to someone not involved with IT for the domain... without any documentation is definitely enough to make sure I never use GoDaddy as internet infra again...

• Basecamp wrote about leaving the cloud. I don’t know if this becomes a broad trend, but between AI leverage, cloud bills, GitHub outages, and people getting jumpy about hosted developer infrastructure, I would not be surprised if more teams start asking which parts of their stack actually need to be rented.

• While I’m dunking on Github, Awesome Agents investigated GitHub’s fake star economy. The open internet is becoming a depressing place, y’all. Oobah Butler’s story about how made his shed the top-rated restaurant on TripAdvisor is funny, but it is also one more case study in reputation systems and social proof not working quite right at modern scale.

• Unforuntately I can’t get away from GitHub right now, but the April incident involving commits apparently reverting earlier merge commits in some cases was a timely reminder that sync and version control are not the same thing as backups. Have you tested your backups lately?

• Speaking of internet infra and best practices... an Obsidian plugin was abused to deploy a remote access trojan thing. It is honestly a little amazing this took as long as it did. Plugins are vetted when they are added, not continuously blessed forever, so be careful out there.

• This deep dive into the secret behind Japan’s railways has some great graphs and charts. Among other things, Benedict Springbett touches on land use, scheduling, maintenance, labor practices, and institutional competence. I took the train to NYC back around New Year’s and it was... fine. A lot more rattly than when I took trains in Japan or Germany; it was roomier than a plane but harder to type on my laptop.

• Here’s a deep dive on why helium is so hard to replace. MRI machines, semiconductor fabs, fiber optics, and aerospace all use it for reasons that are not easy to swap out, which makes helium supply chains way more critical than I realized before chatting with a friend who works with magnets.

• In happier supply chain news, a Japanese company thinks it can push lithium recovery rates from below 50% to around 90% with a new process. If the process holds up it will be great news for stuff like batteries and electrification and green energy and whatnot.

ICYMI

• The most popular items in Some Stuff I’m Surprisingly Happy I Bought were the vertical wooden pen organizer and the also-vertical TESSAN tower power strip (affiliate links).

• The Konik method for making delicious food is less a recipe system than a way to make everyday cooking easier to improvise and relax about, although I do include five of my most common recipes.

• I also wrote about how organisms rewrite themselves, mostly because I felt bad about slightly misstating how octopuses work in my article about How Locusts Cause Famines and Shaped the Middle East.

• I wrote about building a vocabulary for discussing the network effects. The Cold Start Problem book itself was a great look into how communities, institutions, and businesses get going.

For May, I plan to really focus on my health and step away from my desk as much as possible, but I will still keep up my once a week writing schedule and stay on top of correspondence. Please feel free to reach out, especially if you have a great article or book to recommend!

But you may have noticed that April has five weeks, and that means I give myself permission to do something a little unusual. I’m gonna talk about cooking.

Now to be clear, I am what I could call a competent cook. I have friends who are amazing cooks and that’s not my thing. It’s not my favorite hobby, and my husband has what he calls “the refined palate of a raccoon” which is to say he’ll eat basically anything without complaint. I also have two kids who vary in their pickiness levels (moooooom why does it have GREEN STUFF this week?) although I do my best not to indulge the whining (if you really aren’t willing to try it, you can have a sandwich for dessert… somehow we’ve only had to resort to alternates like twice). But I do care about putting a homemade meal on the table most nights, and I prefer it to taste good without costing me too much effort.

If you have ever looked at recipes posted online I am sure you have seen a line like that before. I find that recipe posts come in two varieties:

• “It’s easy, I swear! Just buy these seventeen obscure things that of course I, a cooking influencer, keep in my pantry, and then follow these eighty-two discrete steps to cook something in one pot, and we’ll ignore the fact that you now need to clean every measuring cup and bowl you own.”

• “It’s homemade, I swear! Just mix a can of mushroom soup with a packet of ranch mix and top it with jarred bacon bits and pour it over a rotisserie chicken!”

I am deliberately ignoring the class of instagram recipe that consists of buying vegetables or bread type things and then changing their shape in a way that is either wasteful or requires you to pre-commit to a very specific chain of things like cutting bread into dinosaurs and then making croutons or french toast casserole from the remnants. If that’s your thing, more power to you, but I’m a simple soul, willing to take shortcuts but preferring control over my simple, sensible process.

So here are 5 recipes I cook pretty regularly, that don’t stress me out, that are reasonably healthy and maximally efficient… in approximate order of difficulty: (1) flexible no-knead dough (2) sheet pan meat + veg (3) burgers in the air fryer (4) instant pot sausage & rice (5) dutch oven chicken & rice.

Flexible No-Knead Dough

I know a ton of people got into baking fancy bread during the pandemic as a hobby, but the main thing I learned is the opposite of what everybody on the internet seems to say, which is: bread is incredibly difficult to screw up. I’m not sure that I’ve ever baked bad bread except once or twice when I undercooked because I was trying too hard to follow a recipe precisely. The main thing is to recognize that even if the bread does not come out the way you intended it, it will almost definitely still taste good.

Let me give an example, in the form of what ostensibly started out as a focaccia bread recipe.

1. Combine 2 cups of hot tap water, 2 teaspoons of salt, and 2 teaspoons of yeast. Make sure the yeast bubbles. If it doesn’t you may have killed it, use hot tap water not boiling bottled water!

2. Pour into 4 cups of bread flour. Mix, either by hand or with a stand mixer, until combined.

3. Cover and put into the fridge for 12-36 hours.

4. Preheat the oven to 425F

5. Line a big round dutch oven with parchment paper, plop the dough into it.

6. Top with stuff. I like merlot bellavitano cheese chunks and sliced grapes. Some people prefer crumbled bacon and fried onions. Cracked salt and rosemary is probably traditional. Do whatever.

7. Bake for 30 minutes.

But with a few simple variations, you can turn it into pizza:

4. Preheat the oven to 550F, put pizza stone into oven.

5. Roll out a half portion of dough onto a piece of parchment paper; pinch the edges. Freeze remainder or save for a second pizza after the first.

6. Top with stuff. I like red sauce, shredded mozzarella, and diced chicken.

7. Get the pizza stone out of the oven, slide the parchment paper onto it, and put it all back into the oven for 15 minutes; keep an eye on it so it doesn’t burn, ovens vary. You can use a sheet pan if you don’t have a pizza stone.

8. Let cool before slicing or it will be floppy.

Oh, but you don’t have bread flour? Use all purpose flour, it’ll be fine just not as chewy. Oh, you prefer whole wheat flour? Swap in two cups if you want it to still be springy and focaccia-y, it’ll just be a bit softer and denser. Still delicious tho.

Don’t have parchment paper? Fine, thoroughly grease the dutch oven with butter and cook it directly in the pot; it’ll be a little crunchier, is all. Prefer olive oil? It’ll turn out a bit spotty because of how the bread fries, but you’ll probably be fine. I just got tired of having to wiggle it to free it from my dutch oven. And honestly I only use the dutch oven instead of the pizza stone or loaf pan or whatever because I store it in the dutch oven; after extensive experimentation I’ve discovered bread lasts longer there than in a bread box, paper bag, or alternative method.

Oh you wanted to make soft raisin bread? Bump it to 3cu wheat flour, soak the raisins beforehand, and mix them in. Oh you like your pizza dough flavored and have a ton of garden oregano that you dried last fall? Mix a half cup of dried oregano into the dough.

I’ve given this recipe to multiple teenagers and absolutely 0% of the time has it ever turned out anything but delicious. I do not knead, I measure with remarkable imprecision (sometimes I let my six year old help!), and I’ve never had this bread last long enough to go bad. You can roll it into circles and make buns if you want, why not.

Sheet Pan Meat + Veg

Preheat oven to 350 degrees. Cover a sheet pan with aluminum foil. Onto one side, plop some meat that was cheap at the grocery store that week — pork loin, thick chops; chicken tenders, thighs, breasts, legs; a mid-sized beef roast also works. Season however; there are a thousand and one pre-made dry and wet seasoning options, and a lot of them are surprisingly good. I’ve certainly stopped bothering to mix my own. Costco’s pesto is great, so is most store-bought BBQ sauce. I like Old Bay, Kinder’s Cowboy Butter, and a multitude of other options.

Onto the other side, pick a vegetable or three. We like fresh green beans (snap off the ends), asparagus (cut off the ends and slice into 2” spears), and halved brussels sprouts. Spray with some kind of oil, season. I like to toss some parmesan cheese and raisins on top, but you can do whatever you like.

Bake for ~45 minutes. If your food looks done, but you want it to be crispier or more caramelized, broil it for ~2 minutes.

Burgers. In the Air Fryer. Yes.

My kids like burgers. I’ve tried to make the patties myself but it’s moderately annoying and Harris Teeter’s butcher counter sells amazing burgers that are stuffed with cheese and bacon and onion and all kinds of goodness. I hate babysitting a stovetop with a toddler underfoot and I am for damn sure not getting out the grill. Yes, I know it tastes better grilled. But I have two kids, I get annoyed about dealing with oil splatter, and the air fryer really does live up to the hype. I bought this (affiliate link) dual-zone ninja air fryer back in 2023 and I think it’s super easy to clean and use although a friend of mind with weak hands struggles to push the buttons. I used to think air fryers were silly — the oven is right there! — but the auto-shutoff is amazing with kids and the oven is right there is actually a huge liability with small curious children who cannot reach the countertop but can open the oven on their own.

Anyway, I put the burgers into the air fryer, cook for 10 minutes, flip, cook for another 10 minutes, and they turn out great every time. Top with whatever vegetables you like. I usually just do cold sides like pickles and fruit because we are weird. But you could do a salad if your family tolerates them better than mine.

Instant Pot Sausage & Rice

Ok this one is more complicated, but I like it because the leftovers make a great breakfast. I have had the bog standard 6qt instant pot since 2022 (affiliate link, because why not, it’s great for the same reason the air fryer is great; kids + auto shutoff = low stress) and this is what I cook most often:

1. Use the sauté setting. Heat some oil. 2 tbsp of avocado is enough, but you can use whatever neutral you like, and I’ve never measured.

2. Toss in a package of ground hot italian sausage (or if you like working extra hard, dice some of the tubed kind). The original recipe called for 14oz but I have never measured. Periodically poke it with a stick until it’s brown.

3. While that’s cooking, dice up some garlic (I leave this to your discretion; I usually do obscene amounts), a FRESH onion and two bell peppers (do NOT use the frozen diced bagged stuff, it’s utterly flavorless and depressing in this recipe); I prefer vidalia + colored peppers, but it doesn’t really matter.

4. Put the sausage into a bowl once it’s brown, then sauté the garlic, onion, and peppers (in that order, but it doesn’t matter nearly as much as people online think).

5. Add a cup of stock (chicken is fine, homemade lamb stock is great, water will work fine too, hell you can use beer if you feel like it), and scrape the bottom of the pot with the wooden stick (or spatula or spoon like a normal person).

6. Cancel the sauté function, add like a cup of frozen (bagged, the boxed stuff is weird and annoying) spinach, some corn if you feel like it, and a can of (black? red? who cares) beans.

7. Thoroughly rinse a cup of long grain white rice (the original recipe, which I have unfortunately lost the link for, but it’s fine because I’ve changed a lot of details over the years) freaks out about how you CANNOT use short grain or brown rice; this is basically true but mostly because different rice has different cook times and needs different amounts of liquid; you can tweak the recipe accordingly if you know your rice). Put the rice on top, DO NOT MIX.

8. Add a (14.5oz) can of diced tomatoses, you can get the kind with seasoning or the fire-roasted kind or the plain kind it is all fine.

9. Close the lid of the instant pot ad SEAL the valve. Pressure cook on high for FOUR (4!) minutes. It will beep; ignore the beep, it’s like the “preheated” sound on your oven.

10. When the pressure cooking cycle is over, it will beep a couple of times to let you know it’s “done” ignore that too. Let it do “natural pressure release” for 10 minutes. Basically it will count down FROM four and then back UP to ten. At ten (or so, you’re not gonna ruin it if you don’t vent it soon enough), flip the valve from sealed to vent. Open the lid carefully when the metal pin drops (I originally wrote these these recipes out for teenaged babysitters to follow, forgive me if that seems obvious to you).

11. Fluff the rice and put the sausage back, leave it on warm or turn it off depending on when you plan to eat. If you accidentally added the sausage back in on an earlier step (which I have definitely done) it will be fine, you’ll just get less flavor contrast.

12. THE NEXT DAY: Fry it in a buttered skillet with an egg or three. Yum!

Dutch Oven Chicken & Rice

This began life as One-Pot Autumn Herb Roasted Chicken with Butter Toasted Wild Rice Pilaf from Half Baked Harvest. My version is much shorter (and has a lot more root vegetables), hers is worth checking out if you want something mind-blowingly good with a lot more ingredients.

1. Heat a large dutch oven on the stove. Cover the bottom in oil.

2. Season 1 family pack of bone-in, skin-on chicken thighs (or legs) with something like herbs de province, or oregano and thyme, or whatever europeanish green stuff you like.

3. Brown the skin side of the chicken thighs — for real, actually brown them. Properly brown! Crispy and delicious! You won’t get a second shot at this, they won’t burn, it takes way longer than five minutes it’s okay. Set aside in a large bowl.

4. While that’s happening, prepare your ingredients. Not usually necessary, but this dish moves fast when it gets going. Cut up a couple of potatoes (I buy the package of colorful ones and slice them in half) and 3ish carrots. Quarter an onion, cut some garlic bulbs in half (I usually aim for eight. We like garlic; if I could fit more I’d use more).

5. Reduce heat, add 2tbsp of butter (or don’t, it’s fine, I often skip this step and it’s noticeable but you aren’t gonna ruin it if there’s less butter).

6. Preheat the oven to 400F.

7. Toast 1cu orzo for 2 minutes, then toast 2.5cu wild rice (yes the type matters, no I don’t know why. Splurge on the wild rice). Toss in a packaged of sliced mushrooms (white is fine, baby bella is fine, you can slice your own but they’re the same price at my grocery store so why bother?). Toss in the carrots and potatoes.

8. Add 4cu chicken broth. You can substitute one cup for cider or beer, I’ve even used wine, I don’t usually notice much in the way of a flavor difference unless I use a really strong beer. Scrape up the brown bits with your trusty wooden thingie.

9. Add onion quarters on top. Layer the chicken thighs on top. Nestle garlic heads into the nitches. Spray everything on top with a bit more oil.

10. Cover with lid, cook in the oven for an hour or so — until the liquid is absorbed.

11. Remove the lid for the last 5 minutes to brown the chicken a little more. If you’re impatient, broil it but watch carefully so it doesn’t burn (90s is usually enough).

The apple cider glaze is gilding the lily but does taste good if you feel like babysitting the stove. To get a similar flavor contrast we just serve with lemon slices. Also: the leftovers are amazing; I recommend the microwave for a big scoop of rice, and the air fryer for 5 minutes for the chicken. The skin crips up nicer that way.

I am at no risk of becoming a pro cook or recipe blogger, but I do hope this helps someone make something delicious and stress a little less about making meals. In my experience you can vary things up a lot more often than people online are willing to admit, because for the most part the kinds of people who go looking for recipes the most often are the kinds of people who need recipes instead of just inspiration.

But back when I was doing consulting more often, the most common thing that would happen is I’d hop on a call with someone and they’d explain their problem and I’d say something like “why not just—?” and they’d say “oh, can I? you don’t think that would be too simple or stupid?” and I’d say “no, I think the thing you wanted to do sounds absolutely reasonable and will work out fine” and eventually I felt guilty taking people’s money to say “you are smart and should have more self-confidence and do the thing you planned” even though it was just a “pay what you think I’m worth” type thing, so I stopped.

Anyway you are probably smart and should have more self-confidence in the kitchen; it’s actually really hard to make disgusting food although I’ve certainly managed it, it was usually the sort of mistake one only makes once, like using wildly incorrect proportions because I misread the directions on a totally unfamiliar recipe like pad thai.

Anyway does anybody have an idiot-proof recipe for pad thai? Or any other recipes they’d like to discuss?

So here’s what I wish I’d said, expanded into its own deep dive into how creatures can change their bodies without “adapting” in the traditional, evolutionary sense.

What Phenotypic Plasticity Actually Is

The basic idea is that there’s one set of genes with multiple possible physical outcomes. In the original example, a grasshopper has the same DNA as the locust it later transforms into.

The genotype is an organism’s complete set of DNA instructions, and the phenotype is what the organism actually looks like and does. The genes don’t mutate and there isn’t any evolution-style selection pressure involved. The organism just reads its existing instructions differently depending on what’s going on around it.

This is pretty normal. There’s a study about how that phenotypic plasticity has been a significant factor in maize adaptation, alongside conventional selection. Humans display it too: we build more muscle with exercise, acquire tans after enough time exposed to the sun, and get taller if we have better nutrition (or skip our periods if the food situation is too bad or we exercise too much, like my grandma did when she was a young softball player). But some organisms take it to extremes.

I covered this in more detail earlier, but certain grasshopper species can transform into swarming, crop-devouring plagues when they get crowded together. They change color, breed faster, and start moving as a group after crowding causes physical contact, which triggers serotonin production that flips a behavioral switch.

This phenotypic plasticity and not metamorphosis because of the reversibility. Even fully switched-over locusts can revert to solitary grasshopper form if they are isolated. The behavioral changes start within hours, driven by dopamine instead of serotonin this time.

Then there’s maize. Scientists tested what happened when they grew teosinte (wild maize) under conditions mimicking the early Holocene climate, similar to when domestication actually occurred. The teosinte expressed more “domesticated” phenotypes — which is to say they grew smaller, with fewer branches — than the same plants grown in modern conditions. Apparently (forgive me, I asked Claude, this is confusing stuff) this suggests that “early agriculturalists were selecting for genetic mechanisms that cemented traits initially induced by a plastic response to the environment, a process called genetic assimilation.”

The gene under selection during domestication helps maize adjust flowering time depending on latitude and day length, although of course the farmers didn’t know how it worked on the micro level. Presumably they just noticed that some plants did better when moved to new fields.

In other words, maize may have started being useful because of where it was growing, and then humans locked in those traits through selective breeding so that it did the same thing no matter where you put it.

For an example that’s visible on a single tree, consider holly (which I hate, it’s the only type of tree I’ve ever cut down, pricked my feet soooo much as a kid barefoot in the backyard growing up). Carlos Herrera and Pilar Bazaga found in 2013 that holly trees produce prickly leaves where deer browse and smooth leaves above browsing height. Every leaf on the tree has identical DNA, but prickly leaves are significantly less methylated than smooth ones. The tree senses herbivory and adjusts its chemical markers to change how genes are expressed, producing physical defenses exactly where they’re needed. I mentioned this briefly in my piece on trees as infrastructure, which is a really great deep dive on how trees are criminally underutilized in speculative fiction… but anyway.

Octopuses: Something Different Entirely

When I mentioned octopuses in the locusts article, I said you see phenotypic plasticity “a lot when you look at how an octopus responds to different water temperatures.” That’s... mostly true, but it glosses over what makes cephalopods special.

What octopuses actually do (so far as I know — I’ve been wrong before tho 🙈) is RNA editing. This is a distinct mechanism from phenotypic plasticity.

In standard phenotypic plasticity (locusts, maize, holly), the DNA stays the same and the organism changes which genes it expresses, or how much of a given protein it produces. The instructions stay the same but the organism reads different parts of them. Like a box of legos that accommodates multiple builds depending on which directions packet you elect to start with (PS: Rebrickable is amazing for letting you re-spin different lego kits into different designs... caaaan you tell I have a six year old?)

But RNA editing is more like getting a not-so-artificial intelligence (heh) to actually go and re-write the directions. As I understand it, the process works like this: the cell copies a gene’s instructions into RNA (the working blueprint for making proteins), and then octopuses chemically swap out specific letters in that RNA before the protein gets built. One type of molecular letter gets changed to another, and the resulting protein ends up with a different building block than what the DNA originally called for. Think of it like a copy editor changing words in a manuscript after the author has finished writing but before it goes to print — the original stays intact, but what the reader actually gets is different.

Researchers found that when octopuses are moved from warm water (22°C) to cold water (13°C), they ramp up editing at over 13,000 protein-altering RNA sites — about a third of all their recoding sites — and the changes reach a steady state within days. These edits change proteins involved in neural signaling, membrane function, and calcium-dependent processes, allowing the nervous system to work properly at temperatures that would otherwise impair it. It really is a bit like an AI editing its own config files on the fly to handle a new operating environment (but with careful git ‘backups’ oh my goodness if you let AI edit things on your local files you need to have a good 3-2-1 backup process.)

Joshua Rosenthal, one of the lead researchers, said “the idea the environment can influence that genetic information, as we’ve shown in cephalopods, is a new concept.” Turns out an arctic octopus and a tropical octopus can share virtually the same DNA while producing functionally different neural proteins.

Tl;dr: RNA editing is faster and more reversible than most forms of phenotypic plasticity, and it targets specific proteins rather than whole developmental pathways.

Everything is Tradeoffs

There’s a cost to all this molecular flexibility, though. Coleoid cephalopods (octopuses, squid, cuttlefish) are trading transcription plasticity at the expense of genome evolution. The genomic regions around RNA editing sites are highly conserved, which means they can’t mutate much without breaking the editing machinery. So while cephalopods gain the ability to rapidly adjust their proteins, they lose the ability to evolve those same regions through conventional mutation. I wrote relating AI hallucinations, medieval copywriting errors, and the impacts of radiation on the human genome before, but basically (lol) none of the normal mutations actually “stick.”

Dogs and other domesticated creatures (like wheat!) are sort of the opposite. Domestication bottlenecks reduced effective population size, which weakened purifying selection, and mildly bad mutations that would have been purged from larger wolf populations accumulated instead. And when breeders dragged beneficial alleles to fixation for traits like size or coat type, they dragged bad nearby variants along for the ride — which is why purebred dogs have such high rates of breed-specific genetic diseases. In both cases, intense selection on one function constrains what can happen in nearby genomic regions. For cephalopods, that means function get preserved but dogs end up dragging along “harmful” passengers. The neutral case is probably something red hair and freckles and green eyes often being paired.

At the fastest end, signaling-based phenotypic plasticity (like the locust’s serotonin switch) can reshape an organism in hours to weeks and is usually reversible. Epigenetic plasticity, like holly’s methylation-driven leaf changes, operates over days to seasons and is semi-reversible. RNA editing, the octopus specialty, works in hours to days and is rapidly reversible. And at the slow end, genetic assimilation locks in plastic traits through selection over generations, as happened with domesticated maize.

There are different tools for different timescales and different kinds of environmental pressure, and organisms often use more than one.

& Then We Have Axolotls

I originally wanted to include metamorphosis as a point of comparison, not least of which because a buddy of mine bred them and a they’re just neat animals. But they’re another one of what I like to call “inversion cases” because axolotls reach sexual maturity without ever undergoing the metamorphosis that other salamanders go through. The term for this is “neotany.” They reach reproductive maturity around 12-18 months, and do cute little courtship dances and all even though the rest of their body never “grows up.”

Metamorphosis and sexual maturation are controlled by separate hormonal axes: the thyroid axis (which triggers metamorphosis) is what’s broken in axolotls, but the gonadal axis works fine. So they hit puberty without ever leaving childhood in every other respect. They keep their gills, their fins, their larval body plan, and probably other stuff I’m forgetting.

You can force an axolotl to metamorphose by injecting it with thyroxine, whereupon they absorb their gills, grow eyelids and a tongue, and become terrestrial salamanders.

Contrast that with other salamander species that can go either way. Biologists call this “facultative paedomorphosis,” meaning the animal has the option of staying larval or metamorphosing depending on conditions. In mountain environments, some salamanders stay in larval form because activity in the hypothalamo-pituitary-thyroid axis stays low — the hormonal cascade that would trigger metamorphosis never fires. Whether that’s because of iodine scarcity, temperature, food availability, or some combination isn’t fully settled. Tiger salamander larvae are also known to develop cannibalistic morphs under crowded conditions, which is its own fascinating example of phenotypic plasticity, though I could not find any evidence of Wikipedia’s claim1 that cannibalism provides enough iodine to trigger metamorphosis.

For axolotls, genetic modification to the thyroid resulted in permanent retention of juvenile traits. Domestic dogs do something similar, retaining puppy behaviors like barking, whining, and licking your chin to try and get food... all of which wolves outgrow. Behavioral neoteny in dogs is driven by selective breeding rather than a single hormonal pathway, but they both end up keeping juvenile features into adulthood.

I once wrote a story called the Magic of Marsh Protection, where the snappers trigger metamorphosis by eating enough — facultative metamorphosis ended up being a plot mechanic because the protagonist needed to kill the baby snapper before it got big enough to undergo what is basically a Pokemon-style “evolution” where it’s a much bigger problem for the locals. Pokemon calling this metamorphosis “evolution” is probably the worst thing about the game (my kid is gonna end up so confused when he hits that year in Science class...) although otherwise I think that Pokemon Go is an awesome game, as I explained back in November.

Yes, And?

“Adapt or die” implies an evolutionary process that is generational and permanent. But biology has developed multiple ways to change on the fly, each with different costs and benefits.

Facultative neoteny waits on resources before permitting metamorphosis into an adult state capable of breeding. RNA editing sacrifices long-term evolutionary flexibility for short-term protein flexibility. Phenotypic plasticity trades optimization for the ability to cope with variable environments.

Which is to say, oops, because maize breeders who reduced genotype-by-environment interaction through selection may have inadvertently limited the crop’s ability to handle novel environments — exactly the kind of flexibility it might need as the climate changes, globalization allows pests to spread into all sorts of nooks and crannies around the world, and cultural preferences spread and consolidate. I wrote about how agricultural crises cascade into societal collapse like maize mosaic disease and the Maya, wheat rust and Rome, chestnut blight in Appalachia… and the common thread is monoculture vulnerability.

Understanding when to breed for plasticity versus robustness is one of the central challenges for future food security, which is either promising (they know about the problem!) or terrifying (if it’s hard, maybe we can’t solve it in time to prevent the next potential famine). Which way do you lean?

Further Reading

• wrote a solid overview of the two-spot octopus including RNA editing, and it’s really cute with lots of wonderful pictures. This guy loves California wildlife and honestly what’s not to love?

Note that these are affiliate links, unlike the last time I wrote up a list like this (2023 was my last tax-time purchase reflection). The small amount of money Amazon pays me goes to things like grabbing lunch with readers, paying for the domain name and making pretty pictures as featured images.

• These little rope baskets are apparently a frequently returned item because of their small size, but I like them because of their small size. They’re great for tossing keys or screws or whatever into and they fit neatly on shelves. I am a big believer in giving random crap a “home” so things don’t feel cluttered even when they aren’t all put away properly.

• Although it is properly intended as a hiking backpack, I originally got this 20L Osprey backpack to use as carry-on luggage because my postpartum back is not up to the task of carrying a normal backpack full of travel stuff across a large airport. It took me a bit to get used to it, but the waist and chest straps are incredibly helpful for settling the weight so that it doesn’t pull on my shoulders. I use it all the time now, even just popping out for lunch with a friend, because it’s much more comfortable to carry than a purse and I can keep a bunch of odds and ends (pens, business cards, my Pokémon Go spinner) nice and tidy inside of it.

• My husband and I both use these adjustable dumbbells, which are nice both because they’re easy to hold and because they don’t take up very much space. They’re also incredibly easy to swap the weights for, unlike the screw-on type. I particularly like that they increment in 3lb gaps instead of 5lb gaps.

• We put a bunch of the kids’ outdoor toys and balls and stuff into this deck box, which has held up much better than the other one we bought for our porch even though it gets more direct sunlight. I like that it’s lockable, although currently we don’t bother (ironically, we do lock the one in front, and we ended up having to drill a hole so it’s not weatherproof anymore, bleh. If you want a deck box, get one like this.)

• I bought this knee-length winter coat because of a December wedding in New York and it was so warm and cozy, I love it. I wouldn’t want to ski in it or anything (I have a different coat for slushy snow I’m expecting to exercise in) but it was nice for formal occasions or semi-formal date nights around Christmas. These wide width low heel boots are the first boots I’ve ever owned that are actually comfortable (although note that I have very wide, weird feet).

• I have tried a variety of phone cases over the years, and this Teelovo phone wallet is my favorite. It doesn’t fit many cards (I habitually only carry two, my driver’s license and credit cards), but it’s not bulky at all and it’s quite sturdy.

• My first vertically oriented power strip fits in my bedside nightstand much better than the flat I one I used to use, and it’s much easier for me to keep my cables under control than it used to be.

• I looove these rectangular windowsill planters. I had to repot my succulents and the aloe plant I mentioned helped me save last June in my article about what aloe, flax, & silica gel taught me about timing. These fit nicely on my kitchen windowsill and look so nice, and the tray keeps things from getting waterlogged or soaking my sink.

• I first saw this incredibly well-labelled analog clock at a friend’s house and got one for my living room to help the kids learn to tell time, but I like it for my own sake too. It makes the room feel a lot more homey to not have any screens.

• I bought a lunch box with built-in freezer packs for my kids, but we take it to the park filled with snacks for the whole family, and it’s amazing to not have to worry about icepacks and the lunchbox separate. It just goes right into the freezer and the food stays so cold all day.

• I’ve come to love cotton-linen blends in hot weather, and these pants are so comfortable. Crucially, you can get them in multiple length and waistband size combinations, which is helpful for me because I am taller than average.

Hell, while I’m at it, here are the most clicked on items I mentioned or reviewed in 2025:

• Tiny Experiments by Anne-Laure Le Cunff was genuinely the best self-help book I’ve ever read. I picked it up on a whim and then wrote a whole essay about testing hypotheses instead of setting goals around it.

• I have ten of these Leuchtturm1917 A5 dotted notebooks on the shelf behind my desk, spanning idiosyncratic timeframes across career changes, marriage, and kids. One actually belongs to my son and he references it for his Minecraft notes, it’s wonderful. There’s a linearity to flipping through them that digital notes can’t match, as I explained at length in The Konik Method for Making Analog Notes. I also like the The Official Bullet Journal Pocket Edition. It’s an A6 notebook designed to be used in portrait mode, so it has the same footprint as a single A5 page and fits neatly in my pocket when I don’t feel like bringing a backpack or jacket or purse somewhere.

• Safort bootcut yoga pants and Halife V-neck tank tops. I did not expect “my standard clothing uniform” to be so popular with y’all (most readers I talk to are retired guys!) but it came up in Complaints about immodesty go way back. These have amazing pockets and incredible range of motion but look like office slacks and a blouse. Amazon informs me I have bought 9 pairs of the pants and 12 of the shirts, which sounds right. They last a couple of years, which isn’t bad considering how often I wear them. I use this AmélieBoutik bolero cardigan (I own three) so it works for all seasons.

• The War Dogs Trilogy by Greg Bear was a great book series I picked up on a recommendation ended up reviewing as post-rationalist philosophy in SPAAAACE. I’d get it from the library. I also devoured The Folding Knife in a weekend; it’s by the Sixteen Ways to Defend a Walled City guy but I liked it better. Read Sharps right after.

• The Road Runner: A Very Scary Lesson (Little Golden Book) has a delightfully anti-safetyist message from the 70s, and showcases the Little Golden Book art style I grew up loving. I featured this in Toy Problems Make Economics Easier To Grasp and still read this book to the kids as often as I can.

• This VEIKOU 8x16ft cedar greenhouse is something I mentioned because of the glass-walled garden rooms in a Florentine villa. I came home wanting one so bad. Turns out that for under $2,000 you can get a beautiful cedar-framed one big enough for a hammock, a little table, and a blanket chest, but I still haven’t done it yet.

As a bonus, here are some items I bought even longer ago that I really love:

• this sixteen slot desk organizer continues to be a godsend. It has held up really well since 2021 and was surprisingly cheap and easy to assemble. It actually does manage to hold pretty much all of my stationary equipment and the angled drawers make them easier to see.

• This one-piece wooden cutting board was shockingly cheap compared to most wooden cutting boards I’ve seen, so I was worried the quality would suck, or it would warp, or crack easily. I got it for $30 in 2022. It seems to have gone up to about $40, but it has outperformed boards that were way more expensive, and it has awesome features that help it dry quickly. Even now, it never slips, the grooves are perfect, and the built-in ruler has been surprisingly handy without catching any food particles like I half-expected. It has held up remarkably well over the last 4 years, although I mostly use it for bread because it’s the perfect size for the loaves I bake.

• This soap holder is self-draining, doesn’t fall apart, doesn’t get gross (and is easy to clean when necessary, which is almost never), looks cute and is made out of a single, solid piece of natural wood. I bought my pack in 2021 and they’re all still holding up great.

• I have not bought hair ties since 2022 because these hair ties come in a bag of 100 and are the only hair ties I’ve ever worn that actually don’t wear out or pull my hair when they get stuck.

If you got something useful out of this list consider forwarding it to a friend who might also be interested — and encouraging them to sign up for more honest reviews of random stuff.

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Also, have you bought something in the last couple of years that turned out to be way more useful than you were expecting? Please reach out — I’d love to hear about it, either via email or in a comment on the web version where other readers can see. Especially since Mother’s & Father’s Days are coming up in a couple of months, and my husband and I are both very hard to shop for...

Andrew Chen wrote The Cold Start Problem because he found his own understanding of network dynamics to be, in his words, “unforgivably shallow for something so core to the technology industry.” Chen was trying to build a shared vocabulary for discussing mechanics that most high-level tech folks understand intuitively, but struggle(d) to articulate.

Most people, whether they work in tech or use social media or not, have an intuition about network effects. Products get more valuable as more people use them, that marketplaces need both buyers and sellers, and getting the first core group of people to start showing up to a recurring party is the hardest part. But knowing that and having the words to talk about it after different things. Without a good vocabulary, it’s hard to improve your own mental models, or harder to remember things later. Jargon exists because it offers a useful shorthand.

I have found this vocabulary incredibly useful not only for communicating in professional contexts, but also in personal ones. For example: we like the school our kids attend, but’s the network effects that keep us there more so than the quality of instruction or the educational philosophy.

Let’s get to the vocabulary, then

Chen organizes the book around five stages of network growth: Cold Start, Tipping Point, Escape Velocity, Ceiling, and Moat. I am not going to talk about all of them because they are not all equally interesting to me personally, but this is the lens through which Chen examines how specific companies handled each transition. He added enough concrete examples to ground the abstractions in interesting stories that help contextualize and aid memory.

Along the way, he breaks the classical “network effect” concept down into three distinct forces. The Acquisition Effect lets products tap into the network for low-cost viral growth. The Engagement Effect increases interaction as networks fill in. The Economic Effect improves monetization and conversion as the network grows. These effects require different interventions and fail in different ways, which is why he thinks treating “network effect” as a single phenomenon leads to sloppy thinking.

The “cold start” is a zero state, when a user joins and none of their friends are on the service, or when a search returns no results. Every networked product that survives has found a way to make those first moments tolerable.

The “come for the tool, stay for the network” strategy, where a product offers the utility of the tool on its own first and layers on network effects later, is common precisely because solving the cold start problem head-on is so brutal.

Another useful concept in the book is the “atomic network”: the smallest self-sustaining unit of a network that can function independently.

Atomic networks: the minimum viable unit

The atomic network concept lets you focus on step one on the path to the moonshot goal (millions of customers, big successful parties, a great team to work with... whatever). It starts out as “how do I get this one small cluster working.” The smaller the atomic network, the quicker you can build it and then repeat the process. Messaging apps and video calls need only two people. A marketplace for rare sneakers needs a critical mass of collectors in a specific category. A social network for a particular fandom needs enough active members to generate daily content.

For Uber, it was a single city with enough drivers and riders to ensure reasonable wait times. For Slack, it was a single team that had exchanged 2,000 messages. (Stewart Butterfield found that regardless of any other factor, after 2,000 messages, 93% of teams were still using Slack.) For Facebook, a single college campus was enough. In my experience, a party needs at least four families to feel like a party instead of a dinner.

The thing is, a product (or a party plan…) can be perfectly designed and still fail if it launches in a market where the atomic network can’t form. This is one reason that Chen made such a point of focusing on “zeroes” and empty states, like when a user has no search results returned, no friends available on a given weekend, or no listings showing up in a category.

But the product (or rather: the tool) does matter, and successful networked tools “tend to sound like a meme” when described. Snapchat lets you send photos to friends. Uber lets you hit a button to get a ride. Dropbox is a magical folder that syncs your files… although I am still lookging for the magical app that lets me easily sync two folders, because Claude settings being stored in the users folder is really annoying!

That said, the simplicity limits complexity and cost, and it makes the product easy to describe to the next person you’re trying to recruit into the network. Curating who’s on the network, why they’re there, and how they interact matters as much as the product design (party venue, school) itself.

The hard side does most of the work

Every network has what Chen calls a “hard side”: the participants who do most of the work and are hardest to acquire. On Wikipedia, a tiny percentage of prolific editors wrote most of the content. About 5% of Uber’s users (the drivers) carried the entire marketplace on their backs. On YouTube and Instagram, a power-law distribution means the top 20% of creators generate the vast majority of engagement.

The earliest users of a network tend to have abnormally large contact lists — often in the thousands. Thousands sounds crazy until you realize my newsletter goes out to over 8,000 people. Lots of really famous newsletters (Matt Levine’s amazing Money Stuff for example) go out to orders of magnitude more than that.

Even a normal messaging app like Telegram or Signal might look like a peer-to-peer network where everyone is equal, but in practice there are active, extroverted users (👋) who initiate conversations and organize get-togethers, and there are passive users who respond. Nearly every network has this split, even my personal social groups. It feels weird to say it so bluntly, but I invite people to my house way more often than I am invited to parties and dinners, I am almost always the most active poster of the week in the Discord server where I spend most of my time, and I am very rarely a “lurker” in any social network I actually spend time on.

In retrospect I suppose this is one reason people tend to shovel responsibility my way :P

I’ll admit it’s a little strange to think of myself in such business-oriented terms, but the hard side of a network is also the hard side of any social group. Without the people willing to do the organizing, the group doesn’t cohere. A social network can’t exist without its content creators. A marketplace can’t exist without sellers. “Who is the hard side of your network, and how will they engage with it?” turns out to be one of the most important strategic questions any organizer of a networked {thing} can ask.

Chen suggests a diagnostic: “If a piece of content was created, and no one saw it, would the creator be disappointed?” If yes, the social feedback loop is central to the product’s value proposition. Users publish content, others engage with likes, shares, and comments, and positive feedback drives more creation. Without an audience, creators leave.

“Content creation” usually makes us think of the internet influencers, but you can apply this to beautiful decorations at a school dance, a church bake sale, a neighborhood yard sale… the applications are endless.

One of the reasons I am on Substack instead of Ghost (and Twitter instead of Bluesky, Discord instead of ...I dunno, does anything even compete with Discord?) is because the network effects mean I get answers to my questions. I like to write whether people read it or not (I have tons of words written that no one has ever read and that’s fine), but I do really value feedback and discussion and community and all the things that sharing my writing in public allows for.

Substack understood this dynamic well enough to pay prominent writers like Scott Alexander to bring their existing audiences onto the platform, solving the hard side problem with direct financial investment. “If you have a chicken and egg problem,” as the old wisdom goes, “buy the chicken.” Chen is totally up front that some companies just outright “buy” users.

This doesn’t really mean that a network is “bad” or “doomed” or whatever. Sometimes you can’t grow a network with positive unit economics from day one, and pretending otherwise is a good way to not have a network at all. Some products just spend money.

PayPal embedded itself into eBay’s existing transaction flow, acquiring users who already had the behavior of buying and selling online. The $5 referral fee that lit up the original PayPal network is one of the most cited growth hacks in Silicon Valley history.

Subsidizing driver earnings, offering free first books, fronting huge piles of money to established writers to get them to join your platform...

Sometimes this works, sometimes it doesn’t, because...

Retention matters too! Teamwork and camaraderie create bonds that keep users engaged over months and years, which is harder to manufacture than it sounds. The network has to generate real social value, beyond just the utility of the tool.

Enshittification by another name

One of the ways companies “spend” money to encourage growth is by skipping the “charging users so you can be profitable” stage. Charging users directly adds friction that slows network growth, and every paywall is a barrier to the next person joining.

Mature networks shift from growth to extraction. Chen doesn’t use the word “enshittification,” but this framework describes the same phenomenon. I checked and as far as I can tell, this book came out in January 2022, and Cory Doctorow coined the term in an essay published in January 2023.

Any name you want to give it, tho, the product experience often degrades because the switching costs do the retention work that the product used to do... and companies do eventually want to start making money.

When networks grow, they sort of seed their own destruction. Different forces end up pulling toward expansion or fragmentation. Platform dependence becomes a trap for some parts of the network, for example if you integrate too closely with a preexisting network, allowing them to control your distribution, engagement, and business model, you become just a feature of their network. And you risk getting cut off if you’re costing them money instead of making it for them.

Basically, when large networked products reach immense scale, they become networks of networks with diverse needs, and that diversity creates opportunities for smaller, more focused competitors to peel off subnetworks and serve them better.

This is how Airbnb unbundled vacation rentals from Craigslist. “Unbundled” here means that specialized services broke away from general-purpose platforms by serving a specific subnetwork better than the generalist could. Craigslist could have incorporated Airbnb’s features, but it would have been hard for a small team to respond to one particular subnetwork being carved off when dating, real estate, gig work, and everything else were all being unbundled simultaneously.

The seemingly undesirable niche segments are where the next atomic networks form, and you can kind of see this in a high school context: small groups of nerds are ill-served by mainstream school environments, break off and then end up seeding niche educational entrepreneurship adventures like Alpha School.

The idea is that the incentives stop being aligned and things start to get adversarial (do you really want to pay for a tool you had gotten free?). I spend a lot of time thinking about coordination problems (for example, how cooperation and competition interact at scale) and Chen’s framework explains why quality breaks down. The network itself becomes the “moat” protecting the organization from competition, and the platform’s interests diverge from its users’ interests.

And if network effects describe how value grows as networks expand, Ponzi schemes are network effects in reverse: each new participant adds less value while extracting more, until the whole thing collapses.

An anthology of clever solutions

The scrappy plays are pretty fun, tho. Chen distinguishes between paying with money vs. paying with time and effort — smaller companies that can’t write big checks instead do high-touch work, like building custom functionality for partners.

Paul Graham famously argued that entrepreneurs should do things that don’t scale, and Chen seems to agree that many atomic networks require unsustainable effort to get moving. Brief moments of opportunity like a conference, a campus, or a wave of new technology (hellloooo dumb phones, internet, smart phones, ai), can tip a market if you’re ready with the right idea. Twitter launched during SXSW 2007, when a critical mass of early adopters were attending. Airbnb targeted major local events where hotel inventory was scarce.

The moment matters as much as the product.

For example: it’s really hard to build a new friend group, most of the time. Yet it’s surprisingly easy if you happen to like the cohort your kids start attending school with! About 70% of my real-life social life is hanging out with folks I met via my son’s childcare providers between ages 3 and 5. The remaining 25% is mostly my husband’s college friends. The remainder are neighbors and work friends.

But more than the moment or the product are the high-effort tactics that get the ball rolling.

Many early social networks grew by scraping email contacts from Hotmail, Yahoo Mail, and other clients, using libraries like Octazen (later acquired by Facebook). At the time, these new social networks didn’t look like direct threats to email providers, so the API access was freely available.

Tinder (which is heavily reliant on smart phones) seeded its early networks by throwing college parties. Sean Rad and his team would go to a sorority, get all the women to download the app, then go to the corresponding fraternity and show the men that all these women were already on it (pro tip: on dating apps, women are the hard side). They built one atomic network, then figured out how to replicate it: throw another party at another school. From 4,000 downloads, they hit 15,000 within a month, then 500,000 a month after that.

Uber built an internal tool called “Starcraft,” named after the real-time strategy game, that let general managers click on a group of cars on a map and text them “Go to the train station, lots of riders!” They were literally directing the network in real time1.

Reddit’s founder scraped news websites and posted them with made-up usernames to make the homepage look like an active community. When he went camping for a month after launch and stopped submitting links, the homepage went blank. I was kinda shocked to discover that the bot problem was baked into Reddit from day one by the developers themselves, although I suppose in retrospect I shouldn’t have been. Lots of modern-day tech has shady backstories like this.

Airbnb reverse-engineered Craigslist, not using Craigslist’s (either irrelevant or nonexistent, I can’t remember) APIs, but by building bots to automatically cross-post listings. When a host finished setting up their listing on Airbnb, they could publish it to Craigslist with photos, details, and a link that drove Craigslist users back to Airbnb.

Networks are everywhere

The book is ostensibly about tech companies, but the conceptual framework extends far beyond software. Chen notes, almost in passing, that “money is a network. Religion is a network. A corporation is a network. Roads are a network. Electricity is a network.” And then: “Networks must be organized according to rules. They require Rulers to enforce these rules. Against cheaters. And the Rulers of these networks become the most powerful people in society.”

Religion-wise, the spread of Christianity through the Roman Empire looks different through a network-effects lens. If one wants to be academically secular about it, the early church faced a classic cold start problem: how do you build a community of believers when much of the value of belonging to the community depends on other people already being in it? Jesus and the apostles started with people on the margins: criminals, low-class women. The solution involved atomic networks (individual congregations), a hard side (clergy and missionaries who carried the whole operation), growth hacks (miracles, martyrdom as social proof), and a tipping point (Constantine’s conversion making it the state religion). One can model the rise of evangelicalism this way, with megachurches as atomic networks and charismatic pastors as the hard side.

We can go even further back. The kula ring of Melanesia — a ceremonial exchange network where shell ornaments circulated between island communities — is basically a prehistoric atomic network. The elites who participated in kula exchange built the prestige relationships that held the network together, making them the “hard side.” But the kula ring also enabled a parallel layer of ordinary trade: while the high-status partners exchanged ceremonial valuables, everyone else traded food, tools, and raw materials alongside them. That two-layer structure — prestige relationships enabling utilitarian exchange — maps surprisingly well onto how modern platforms work, where a small number of highly engaged users create the conditions for everyone to get value from the network.

The merchant class emerged because the structural conditions (trade routes, legal frameworks, surplus production) created an environment where merchant networks could sustain themselves. The atomic network for a Phoenician trading colony was a single port with enough resident merchants and enough regular cargo, and also trading partners in the surrounding region willing to exchange goods.

Looking back at the “dense networks are exponentially valuable” piece, consider how a tight-knit guild of fifty glassblowers (or weavers, or…) in a single city exerts more economic influence than five hundred scattered weavers who never interact.

On spherical cows

Metcalfe’s Law holds that the value of a network grows proportionally to the square of connected nodes. Originally formulated in the 1980s by Robert Metcalfe for selling Ethernet, it was later repackaged as the value of a website growing non-linearly as it added users. Basically if a network doubles from 100 to 200 users, its value quadruples rather than doubling.

Chen says that this is basically a spherical cow, which if you’re not familiar with those it’s a physics joke about oversimplified models. “Assume a spherical cow of uniform density.” Physicists use it to mean a model that strips away so much real-world complexity it barely resembles the thing it describes, but still captures a useful directional truth. Whenever I argue with economists, I like to point out that humans (with all our lovely, irrational behaviors) are not spherical cows.

Metcalfe’s Law assumes every connection is equally valuable, which is obviously false. Your relationship with your best friend is worth more than your connection to the person you met once at a conference. Real networks are messy, with clusters of dense connections and vast stretches of indifference. The law is directionally useful because more users generally means more value, but the specifics of how and where the valuable bits end up being are more complicated than power laws, especially in the beginning stages of the network before statistics start to matter.

Ok but was it good?

In addition to being unusually well-written and engaging, this book is broadly useful in a way that’s rare for business books. The standard audience is obviously anyone building a marketplace, platform, or product. Beyond that, it’s useful for understanding why dominant platforms behave the way they do — why they degrade over time, why they resist interoperability, why they acquire competitors rather than competing with them. This book gives you the structural vocabulary to discuss those dynamics instead of vaguely gesturing at “monopoly” or “greed.”

If you think about coordination problems, collective action, or institutional design, the network-effects framework maps onto those domains in ways Chen doesn’t explicitly explore but that become obvious once you have the vocabulary. The hard side of a network is the hard side of any collective action problem: the small number of participants who do the work and without whom the whole thing falls apart.

The concepts are more durable than the examples, which are mostly success stories. Normally I would be wary of survivorship bias, but the vocabulary was more useful than the how-to guide in some ways so the precise samples used doesn’t matter that much. I have long since forgotten what growth hacks Dropbox used. It might have been fun if there were more matched comparisons companies with similar starting positions that made different choices and diverged in outcomes. But that is a different book, and a less readable one (too much algebra)... 7 Powers: The Foundations of Business Strategy by Hamilton Helmer :P

What I got from this book is that I’ve really started to think in terms of “growth hacks” in general, cold start problems, atomic networks, how I can’t abandon a shoddy tool because of the value of its network, institutional infrastructure, etc. The vocabulary of The Cold Start Problem has improved my understanding of everything from the 1177 BC era Bronze Age Collapse to the real value of how well my son’s kindergarten classmates are already integrated into my social group. I highly recommend checking it out, or at least Andrew Chen’s articles about why it’s hard to evaluate new social products, how the supply side is king, and what the power user curve really means.

Anyway, March’s list has less ‘productivity’ and more ‘ai’ information, but I focused less on tooling and more on figuring out the impacts of all these new ‘productivity boosts.’ I still found plenty of time to read about neat history and science stuff too. I also picked up the latest fantasy novel from my favorite authors, the husband-and-wife team of (Gordon &) Ilona Andrews. It’s a portal fantasy where a woman from Texas — “Maggie the Undying” — ends up in the world of her favorite fantasy series (which, much like my favorite childhood fantasy series, tragically lacked the expected third book in the trilogy), and uses her knowledge of events (past and future!) to try and prevent all the nasty stuff she knows is coming down the pike for her favorite characters.

Those are, by the way, Amazon affiliate links, I earn a small commission if you click through and buy, blah blah it’s 2026 you know the drill.

Anyway, on to the rest of what I read in March!

Productivity & AI

• , a librarian by training, put together a handy bunch of Google tricks. I have pretty good Google-fu already, but I learned a few things from this one. Might be worth teaching some of these tricks to your AI agent, too.

• Katie Parrott at Every wrote about how AI was supposed to free her time but consumed it instead. Basically the hot new phrase is “Jevons paradox” where cheaper tasks just make you attempt more of them. I found it extremely relatable because I often “save time” with Claude only to immediately expand the task into things I wasn’t able to do at all before.

• Max Woolf, historically an AI skeptic, wrote a detailed walkthrough of trying AI agent coding with Opus 4.5 for Rust and Python. It reliably produced correct, performant code, and I trust his report specifically because of his earlier skepticism. I also appreciated his aside that he intentionally makes his writing voice more sardonic to fend off AI accusations.

• Daniel Phiri wrote about why filesystems are having a moment in the AI agent ecosystem. He also flags finding that context files can actually hurt agent performance when they’re too long, which tracks with my experience. I do wonder how long it’s going to be like this; there are a lot of benefits in abstracting this stuff away from “normal” users (see also: Google Cloud).

• Anna Tong and Rashi Shrivastava at Forbes reported on how Cursor is scrambling to stay relevant as Claude Code and Codex eat into the code-editor model. We’re currently in an age where companies like Anthropic are “subsidizing” the “enterprise” plans (200$/mo Claude Code is like $5k in API costs). So Cursor’s working on building its own coding models on top of DeepSeek and Qwen. Personally I am keeping a close eye on the “cheap, lightweight specialist” AI vs “expensive, big, generalist” AI race. For example, someone figured out that dedicated customer service chatbot models outperform general-purpose ones.

• Cesar Hidalgo wrote about what happens when you loop an AI paper-writer with an AI reviewer. The resulting paper kept getting longer because the AI reviewer never exercised “strategic forgiveness” the way human reviewers do, which is to say that they kept hammering instead of considering a response “good enough” and getting tired of asking for revisions. My own experience is the opposite — AI back and forth results in the agent trying to get out of fixing anything because “it’s probably just a flaky test, no big deal” when the whole app is nonfunctional :P

• Jeffrey Emanuel wrote a practical guide to feeding your tax return to an AI, decomposing it into context-sized chunks to find deductions and spot errors. Some of the specific techniques are already outdated since context windows have grown, but the core idea holds up. I used AI to help with some tax forms this year and it saved a real chunk of time, even accounting for a thorough manual check afterward. In point of fact, it made fewer errors than my actual tax professional, who missed a $49 entry during data input. Patrick McKenzie, who I trust completely about financial matters, as found AI helpful for tax things too.

• Nir Barak wrote about rewriting JSONata as a pure Go library with AI in seven hours, going to native Go and saving $500K/year. The main thing was having a well-defined spec with many hundreds of existing test cases to validate against, but this is interesting to me mostly because it’s a good example of a really beneficial way of using AI rather than just shipping faster slop or, you know, building dashboards.

• Mario Zechner (who built pi, a lightweight and extensible coding harness that I’m coming to love) wrote about slowing the fuck down with agentic coding. His argument is that autonomous agent swarms compound tiny errors at a rate humans never could, because agents don’t learn from mistakes and there’s no bottleneck to slow the rot. Agents cargo-cult bad architecture from their training data and each agent only ever has a local view of the mess it’s creating. It’s very tempting to completely refactor my vault with agent swarms, but thus far I have avoided giving into temptation because of precisely this.

• wrote a measured breakdown of the fault lines in the AI economy, assigning percentages to six plausible scenarios ranging from “flop” to “structural post-work.” I appreciated the historical grounding in stuff like the Industrial Revolution and the Great Depression and the fact that it seemed reasonable instead of hyperbolic panic or dismissiveness.

• Weco is an autonomous code optimization platform where you hand it source code and a performance metric, and it iteratively proposes and tests improvements. I share this not because I expect anyone here to purchase their services, but because the examples page is an unusually good look (compared to, for example, twitter hype) at where AI is really paying off. For example: a massive improvement on detecting X-ray abnormalities and a big improvement on cleaning up images in preparation for OCR.

History

• This month I read Stephen R. Bown’s Merchant Kings, which covers six monopoly trading company leaders who ended up as de facto dictators from 1600 to 1900. It was a really interesting book for 95% of the way, and then went off the rails at the end when he started moralizing, which involved a lot of contradicting his own words and speculating in the most uncharitable ways. I still recommend it for people curious about how obsessively driven mercantile men helped shape the world, but I’m irked at the epilogue.

• Paul Graham wrote about the brand age, tracing how Japanese competition forced the Swiss watch industry to shift from craftsmanship to brand identity. It was a bit surreal because I had just written about Japanese artisanal watchmakers in my review of The Perfectionists by Simon Winchester.

• Jake Hubbert wrote a paper for BYU about how Islamic visual culture impacted medieval Georgia’s religious and secular art. It traces Persian portraiture techniques through monastery frescos, illuminated manuscripts, and fortress architecture from the 7th to 14th centuries and was a pretty neat look at a country that I have learned remarkably little about before. I got interested in Georgia because a team is studying the fortress of Dmanisis Gora in Georgia to figure out why Caucasus communities weathered the 12th century BC crisis better than the rest of the Middle East. The site is unusually well-preserved because of how flat it is, so they’re hoping to find stratified layers from right around the collapse.

• wrote a long, affectionate essay on nearby Armenia, covering everything from its status as the first nation to formally adopt Christianity (301 AD) to its Bronze Age archaeological record, which includes the world’s oldest shoe, wagon, and wine-making facility.

• Rune Iversen published a classification of over 600 engraved “sun stones” from Neolithic Bornholm in Antiquity. The stones were deposited around 2900 BC, probably in response to a volcanic cooling event that darkened skies and wrecked harvests across the northern hemisphere. It’s pretty interesting how consistently people get more religious during times of stress, even five thousand years ago.

• wrote a walkthrough of the surprisingly dramatic history of candles, from tallow-dipped medieval rushes to the absurd logistics of lighting the Hall of Mirrors at Versailles. It’s not quite Salt or Cod, (or even Coal, which I reviewed back in February), but it’s a nice look into how a mundane object can be a window into class, labor, and the politics of who got to see after dark. I particularly enjoyed the pictures.

• wrote about why Florence specifically sparked the Renaissance, tracing a convergence of geography, political independence, wool-trade wealth, and proximity to Roman ruins. A ruined cathedral plays a surprisingly big part in the story, and it reminded me a little of other arguments I’ve seen about why it had to be Britain for the Industrial Revolution. His angle for carying about Florence is figuring out what makes places like it and Silicon Valley so special, so we can replicate the magic. I’m not sure that’s doable on command, but it was still an interesting story with lots of interesting maps and graphs.

• wrote about why Scotland punched so far above its weight from the 1740s onward. It’s a convincing case that Scotland’s real advantage was its financial system: Scots law let unchartered banks grow much larger than English ones, overdrafts were invented in Edinburgh in 1728, and even artisans without land could earn interest. Glasgow’s merchants used that capital edge to dominate the tobacco trade, and when the American Revolution wiped out their Virginia warehouses, they were well-capitalized enough to just pivot to Caribbean sugar. It’s a good companion piece to the Florence article above.

Science

• (the “Graphs About Religion” guy) looked at why belief in the afterlife persists even as church attendance drops. 88% of Americans believe in a soul, and the youngest adults in the survey actually bounced back toward higher belief in heaven and hell compared to millennials. The concept of “religious residue” was a new term for a phenomenon I’ve definitely come across before — you can leave the church, but spiritual frameworks stick around in your psyche longer which is how we end up with the concept of “cultural Christians” and “secular Jews”.

• One neat thing about chimpanzees that I never noticed when I visited them in zoos... you can’t really tell where they’re looking. Scott Travers went pretty deep on why humans are the only primates with white sclera, and the answer gets into self-domestication (which you may remember I touched on extensively in my article about how and murder were critical to the domestication of Homo sapiens sapiens), the evolutionary value of eye contact, and the genuine tradeoffs of making yourself more readable to everyone around you.

ICYMI

• I reviewed Steve Brusatte’s excellent book The Rise and Reign of the Mammals, which covers hundreds of millions of years of mammalian evolution. I had a lot of fun with the deep-time ecology stuff and learning about how important teeth, jaws, and ears ended up being.

• I wrote about geldings and the “natural” social order of horses, starting from a throwaway line in an archaeology paper about Mongolian herds. It’s part horse history, part philosophy of domestication, part reflection on the value of ‘unproductive’ males and the nature of ‘natural’ as a concept (see what I did there?). This one got a more likes but fewer comments than I expected.

• I also wrote about why I built two custom dashboards instead of using off-the-shelf analytics, and what I learned about the difference between data you look at and data you actually use.

Stay tuned for my upcoming review of The Cold Start Problem: How to Start and Scale Network Effects by Andrew Chen, an article about different ways organisms change their phenotypes, and a look into the benefits of diversity for large empires.

This month I’m reading Hard Landing: The Epic Contest for Power and Profits That Plunged the Airlines into Chaos by Thomas Petzinger, Jr. and it’s fascinating so far. Next month’s book is slated to be How Africa Works: Success and Failure on the World’s Last Developmental Frontier by Joe Studwell. I’m planning another visit to Harpers Ferry with my son, and looking forward to seeing Project Hail Mary (which everyone I’ve talked to says is great, a relief because I loved the book) with my husband over Spring Break.

And, as always, if you read anything particularly interesting last month — or end up reading anything above and want to discuss — please leave a comment or shoot me an email :)

So when I saw people on twitter dismissing Claude-built dashboards as productivity porn I kind of shrugged and didn’t care. But some of my colleagues built some custom dashboards and as soon as I saw them in a context of use I understood, with pain points I shared, I leapt to build my own.

The key thing is that they aren’t just for analytics, my dashboards are a one-stop-shop GUI on top of my common workflows.

I now maintain (it would be wrong to say I merely “have” them :P) two custom dashboards, and I am in love with them. One tracks information for my day job at a software company: channels I need to monitor, action items I need to check off, and patterns I need to be aware of. The other (which was very quick to build once I figured out all the fiddly bits for the other) is for handling social media and this newsletter: things I ought to reply to, my calendar of scheduled content, and notes on stuff I’ve read and annotated lately (here’s a quick tweet about the data sources for the dashboard section below… hopefully it loads!).

Crucially, I now spend a lot more time in this dashboard and a lot less time getting annoyed at the slop and crap the various apps try to feed me.

On the difference between analytics and operations

Most analytics tools I’ve seen are built around the question “how are things going?” They give you charts that go up and to the right (or not), and you look at them and feel good (or bad). I get why they do it — for companies, it’s important to know how something is performing so you can adapt, and for companies selling software to content creators the dashboards offer a behavioral nudge to get the creators making money.

Tbh, I really hate vanity metrics. I have always tried to find ways to turn off subscriber counts and view numbers in both Substack (it’s now possible, I think, which is ironic) and Ghost (which is open source so it’s technically possible there, too), but as a default, the platforms want you to see those metrics because that is how they make their money. If your number goes up, their number goes up, so they nudge you to make your number go up. The whole incentive structure is designed around their goals, which I don’t begrudge — it costs money to send emails and host websites and they are footing the bill not me. But nonetheless I generally go out of my way not to be influenced by vanity metrics and the nudge to optimize for money.

Goodhart’s law says that when a measure becomes a target, it ceases to be a good measure. Off-the-shelf analytics platforms choose your “key performance indicators” for you, and those KPIs shape your behavior whether you want them to or not. Building a custom dashboard means choosing your own metrics, which means staying in control of what you are optimizing for. You can build a dashboard that nudges you toward the goals you actually care about, instead of the ones your opinionated tool thinks everyone should work toward.

And lest you think to yourself “don’t be ridiculous Eleanor, of course you want to increase your subscriber count, you always ask us to share your articles with people we think will like them,” well, sometimes, the best way to achieve my goals is to ignore them… Claude’s reminders not withstanding.

My newsletter dashboard does not have a big subscriber count front and center. Instead, the first things I see when I open it is a “respondables” card are comments, mentions, and shares across platforms that I could reply to. It is much more useful than the notification sections of the various apps because it does not have all the likes and boosts mixed in, and it actually clears things when I check them off. It surfaced some pings I had completely missed even though I am pretty active on my social media accounts and try very hard to engage with everyone who reaches out. (Seriously, I love to chat. For algorithmic reasons I prefer comments on Substack of course, but the whole reason I do this at all is to have good conversations.) It also helped me find places that people had shared my articles that I was totally unaware of, like this r/femalemonarchs post about my article about the Ottoman queen Roxelana.

Beside the list of pings I ought to respond to, there’s a list of drafts I’m in the midst of that aren’t in Substack yet. If I click them, they automatically launch the file in Obsidian so I can start working on it. There’s also a list of scored reply candidates — threads in various places that I scrape (certain subreddits, hackernews) where my expertise is relevant and I might be able to help. My searches are optimized for finding discussions I can actually contribute to, which is quite unlike most social media algorithms.

On mini-maps and checking in

Back when I was learning how to play League of Legends, I was frequently lectured by my teammates about how the best players check the mini-map every ten to fifteen seconds. The mini-map is small and peripheral, and a pretty normal instinct is to focus on the fight your avatar is engaged in. But to avoid getting flanked, you have to build the habit of glancing at the overview.

A dashboard is like a mini-map. It exists to answer the question “is there something happening outside my current focus that I should know about?” And the answer to that question is only useful if checking the map is quick and easy. I keep both of mine up on my second monitor, where I can glance up, tap refresh, and then keep cruising on my work without risking distraction.

This, by the way, is why information density matters a lot to me. A dashboard where every number lives on its own page, requiring clicks and scrolling to reach, is a dashboard I will not check. I prefer filter pills over dropdown menus, collapsible sections instead of separate pages, and sorting and filtering options on every table column. Convincing Claude to build click-throughs from every chart element into a detail view has been an adventure.

The information needs to be scannable, the way a map is scannable. If I have to scroll a bunch to understand the state of things, I will just skip it and (not at all metaphorically) get flanked... because things are moving so fast right now; not just in software, but with my offline life, too. My husband just had surgery, my daughter is deep in the throes of dropping naptime but still napping at school (which means 10:30pm bedtimes and sometimes, 5am wakeups), and I am finishing up some classes.

But I still need to keep on top of things at work, and I’m determined to keep up my social obligations and this newsletter. So thanks to my dashboard (and Claude’s little reminders), I am building an even better habit of checking in with the bigger picture — metacognition and executive functioning require building habits of reflection, and while I have always been pretty good at all that, there’s always room for improvement.

On pretty vs useful design

Good design (like what’s offered by this really useful frontend design skill for AI tools) often tries to get rid of redundant information and explainers to look cleaner, but I want all the words. I want labels that remind me exactly what each button does. I want the context right there, not hidden behind a hover tooltip I will never find. This is partly personality and partly learned from using RSS to curate opportunities: my RSS workflow is built around scanning and filtering, and processing feeds in short bursts, because I read very fast. My dashboards take advantage of this; I don’t know how well this would work for other people who do not read quickly at a glance, so please report back.

My taste in dashboards follows the same pattern as my taste in Obsidian themes. I have always gravitated toward themes like my own Palatinate, which was deprecated by Sanctum, and my now-preferred Primary. These are chill and soothing, but have solid contrast, keep all the interface elements visible and labeled, and in fact add extra labeling like my beloved infoboxes and better checkboxes. I avoid ultra-minimal themes that hide controls for the sake of aesthetics because I often go months at a time without touching a tool (maybe I’m sick, maybe I’m busy with something else) and when I come back to it, getting back up to speed needs to be quick.

I still haven’t memorized the shortcuts for making dotfolders visible on Mac, or the one for deleting a whole terminal line. I like tooltips.

The worst possible dashboard is one that looks impressive in a screenshot but requires three clicks to reach the information I actually need.

Back in 2022 I wrote a whole article about shortcuts for finding the middle ground between pretty and practical so I won’t continue to bore you here; go check it out, I just looked it over and removed the archival paywall.

On SQLite and simple tools

I did not want to deal with libraries I did not understand, which is part of why the architecture of my dashboards is so simple (although... not easy, not for someone as barely-technical as me!). I don’t have any libraries, although I did briefly consider building in a lightweight markdown editor using CodeMirror 6 (what Obsidian is built on top of). In the end I decided to just launch my drafts in Obsidian.

Both dashboards use SQLite, Python, and React, all of which I’m at least vaguely familiar with. SQLite runs in a single file on my laptop. The backend is a FastAPI server that starts in under a second. If something breaks, I shrug, restart it, or ask Claude why it didn’t run its tests before telling me a change was done :P

I am never going to sell (or even open source) this thing because it’s extremely custom and honestly kind of brittle, and I don’t have time or the philosophical conviction to make it available to everyone because unlike, say, my Obsidian themes, it is extremely idiosyncratic. Even my work dashboard setup would barely be useful to my team; they’re better off building their own, albeit based on shared data. If you would like to build your own, I did have Claude write out some dashboard creation tips for future agents, and you should be able to just link this article and the gist file.

When the tool breaks (and it’s me: it will break, it would break even if it had 20 engineers full-time dedicated to making it perfect according to my whims, have you met me?), I want to fix it in minutes, in a language I can squint my way through, on a machine I not only control but understand (i.e. not a digital ocean droplet, not a virtual machine, not a dockerfile).

There is an old argument in personal knowledge management about local-first tools versus cloud services. I like Obsidian because it lets me control almost everything about my notes, and it is fast. I ended up using Substack over Ghost because it has much better network effects (stay tuned for my forthcoming article about this!) but also because I do not want to maintain my own mailgun and stripe integrations anymore or deal with any of the other little edge cases I kept running into. Where I come down on the spectrum of complexity, control, privacy, and maintenance cost is variable depending on what is going on in my life at any given time, and I am confident that where you come down on these things will be subtly different from me along several different axes.

But hopefully this article is useful for you (or someone you know!) anyway.

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On what actually gets looked at

The most important principle I have learned from building dashboards is that every piece of information should either tell me something I did not know or prompt me to do something specific. If it does neither, it is clutter.

Early versions of my newsletter dashboard had the default topline KPI cards: total subscribers, total views, total posts. The AI built those because dashboards are “supposed” to have KPIs at the top, and the first thing I did was rip all that out because I knew roughly how many subscribers I had. It does not change that much on a day-to-day basis and seeing the number did not make me communicate differently with people. Claude was copying a convention, operating from the id of the internet to serve the median case, not me.

Now I have inline task lists, drafts I still need to finish, things I need to respond to, and other action items. Posts that got a strong enough response awhile back to warrant a bump are listed out in a bite-size, responsive chunk. My dashboard is basically a custom, self-updating, smart todo list and I didn’t even have to learn reverse polish notation to use it.

At work, I have channels I need to monitor where I check things off when they are done, but Slack does not make completed messages disappear, and the channel gets noisy. It is hard to concentrate on action items when they are buried in conversation, and reminders are not accessible to my AI tools and they are hard to sort. I could move everything to a ticketing system like Linear, but I prefer not to mix streams, and that would be a lot of overhead for things that are fairly simple. The dashboard helps me filter out completed things using a simple heuristic based on a specific emoji, and uses simple API fetches to pull data in. It doesn’t even really need AI once it was built, although I do like the lightweight summarization that headless haiku can provide (among other things!).

On building for yourself vs buying (or not)

I am not recommending that everyone build custom dashboards (although if you want to, don’t forget that I put some hard-won advice into a gist file for coding agents to learn from). The upfront cost is nontrivial, the urge to fiddle instead of work is a real concern that nerdsnipes a lot of people in the knowledge management community, and most people’s analytics needs are either adequately served by existing tools or realistically nonexistent. Jira gets a bad rep but it is probably a bad idea for every engineer to go build their own idiosyncratic version.

The conventional wisdom is “use existing tools, don’t reinvent the wheel.” That advice is correct for most people, most of the time. My needs are unusual enough that no off-the-shelf tool does what I want (even ignoring the fact that none of them do it at the price point I am willing to pay for a newsletter I do not go out of my way to monetize, although you’re obviously always welcome to help me out with hosting costs and the like!)

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The issue is compounded by how nervous I am using software where I don’t have confidence in the business model. I trust that YouTube is going to continue existing in five years; it makes Google a lot of money, and it’s pretty stable at this point. I am less confident that a company completely dependent on Twitter’s API is going to continue to update their analytics software the next time Nikita & Elon fiddle with things.

With a custom dashboard, I do not need to wait for tools to figure out how to integrate niche platforms like Substack Notes (which does not have a public API) and Tumblr. My preferences are rarely aligned with what analytics tools offer, and I would rather build exactly what I need than compromise on what some product manager decided (probably correctly!) was a relatively rare use case for someone likely to spend money on their software.

So if you find yourself repeatedly opening multiple tools, cross-referencing numbers in your head, waiting forever for big corporate dashboards to load, trying to squint through multiple API call results in your terminal, making decisions based on fuzzy recollections of data you saw last week… that friction is solvable now, thanks to AI tools like Claude Code.

And I think it’s worth doing, because building a dashboard like this taught me a lot, not just about databases (and backups! and tests! and APIs and scraping and...)

The act of deciding what goes on the dashboard forced me to really think about what I actually care about, similar to how writing notes and articles forces me to articulate things I thought I understood...

How do you feel about dashboards? Have I changed your opinion at all?

It also, if you think about it for more than a second, cannot possibly be how natural horse societies work. Geldings are castrated males. Castration is surgery performed by humans. There is nothing “natural” about a gelding.

What Truly Wild Horses Actually Do

To understand why geldings don’t belong in a “natural” herd, it helps to look at what horses do when humans aren’t involved at all.

Przewalski’s horses are the only surviving truly wild horse species. They were never domesticated, and are genetically distinct from domestic horses. Not even my beloved Polish Konik horses hold this distinction. Przewalski’s horse social structures have two components: harems and bachelor bands. A harem consists of one dominant stallion, several mares, and their offspring up to about two or three years old. When young males reach reproductive age, the dominant stallion chases them out. The evicted males then join bachelor bands, which are groups of young stallions who spar, play-fight, and form surprisingly stable social relationships while they wait for their shot at collecting a harem of their own.

This is the actual natural social structure of horses. Note the distinctive lack of geldings.

In truly wild populations, the bachelor band solves the “surplus male” problem. Most stallions never breed successfully — research on feral horse herds in Utah with the ungainly title ‘Effect of adult male sterilization on the behavior and social associations of a feral polygynous ungulate: the horse’ found that just 7% of males sired 44% of foals at one site — but bachelor bands give non-breeding males a social life. They hang around, they establish dominance hierarchies through ritualized sparring, and occasionally one of them gets strong enough to challenge a harem stallion and take over.

Giraffes do this, elephants do this, hell even spear-nosed bats do this. You know what they don’t do? Get their testicles cut off without human help.

That Utah feral horse study offers a ‘natural’ experiment in what happens when you geld some males in a population and leave others intact. Gelded males who already held harems gradually lost them. Gelded bachelors stayed bachelors, while intact bachelors of the same age mostly went on to acquire harems.

In a truly wild horse population, bachelor bands are a training ground. Young males learn to fight, establish dominance, and eventually challenge for breeding rights. Remove that system and replace it with geldings, and you’ve fundamentally altered the social dynamics of the species — in a way that seems (is?) fine because conflict between male horses is no longer as necessary to the process of working out which horses are reproductively fittest.

What Mongolian Herders Do Instead

Mongolian pastoral horse management replaces the bachelor band system with gelding. Instead of letting young males form their own social groups and compete for mates, herders castrate most colts at around two years old, keeping only a few select stallions for breeding.

The practice has deep ritual dimensions. According to ethnographic accounts from Mongolian herders, castration is a communal springtime activity. The colts are caught, their legs tied, and the surgery performed with a knife cleaned in boiling water. The wound is rinsed with mare’s milk — which sounds strange unless you know that mare’s milk has antimicrobial properties… much like human breast milk, which gets pushed pretty often in mom’s groups as useful for healing wounds and rashes. Dabbing a bit of breast milk as a topical ointment does actually accelerate healing as far as I know, even compared to ‘normal’ topical medicines. Anyway, the way the castration works with horses is that one removed testicle gets pierced and tied to the new gelding’s tail; the idea is that by the time it dries, the wound will have healed (sort of similar to how umbilical clamping works with human babies, I guess?).

The other testicle is cooked in ashes and eaten by the men present, the ritual purpose being to absorb the stallion’s vitality.

Then, getting back to the practical side of things, geldings are calmer and more tractable than stallions. This is why they’re the default riding horse. This distinction is so fundamental that it is baked into the Mongolian language itself. The word mor’ — which refers to a gelded horse — is also the general term for a riding horse. You can ride a stallion (azrag) or a mare (güü), but the most useful horse, the horse you picture when someone says “saddle up,” is a gelding.

Meanwhile, each stallion watches over 15 to 50 mares. The stallions herd, protect, and breed. The geldings slot in underneath them socially — occupying in a totally different niche than how bachelor stallions would fill in a wild population. They lack the hormonal drive to challenge the harem stallion or disrupt the herd’s structure and so tend to act like juveniles forever.

From the herder’s perspective, this is far more convenient than maintaining volatile groups of intact young males. I guess since humans deal with most of the other steppe predators that testosterone probably helped primordial stallions fight off, it all works out.

Origins of the Gelding Rituals

The ancient Greek geographer Strabo, writing in the first century BCE, noted that “it is a peculiarity of the whole Scythian and Sarmatian race that they castrate their horses to make them easy to manage; for although the horses are small, they are exceedingly quick and hard to manage..” Aristotle mentioned geldings too, and the Scythians (roughly 900–200 BCE) are generally credited as some of the earliest documented practitioners of horse castration.

But detecting gelding in the archaeological record is hard. Prior methods relied on the slenderness of limb bones — the assumption being that castrated males develop more gracile skeletons than intact stallions. A 2023 study in iScience developed a DNA methylation–based method for detecting castration in ancient horse remains, which seeeeeeeeems a genuine breakthrough? The researchers tested a bunch of ancient horse specimens and if I’m reading this right, at least some of the horses from the famous Pazyryk burials in Kazakhstan (circa 300 BCE) weren’t actually castrated. These Scythian-era ritual sacrifice horses, which previous researchers had classified as geldings based on their slender leg bones, appear to have been intact males after all.

If the Pazyryk horses weren’t gelded, then maybe either Strabo was generalizing about a practice that wasn’t as universal as he claimed, or castration was reserved for working animals while intact males were preferred for ritual sacrifice? The archaeological picture of when and where gelding became standard practice on the steppe is pretty murky, alas, and honestly a lot of these papers are way over my head.

Why “Natural” Stops Being a Useful Category

That’s okay though, because although horses and steppe nomads are cool and all, the main reason this dug into my brain is how the word “natural” breaks down, in this context and in others. As Alice Roberts argues in Tamed, the distinction between natural and artificial selection is a tricky one:

“Describing artificial and natural selection separately is a false distinction. It doesn’t really matter that it’s humans — rather than the physical environment or other species — that are mediating the assortment of individuals into those more or less likely to successfully reproduce. You wouldn’t make this distinction for any other species.”

Roberts uses the example of honeybees selecting for flower traits. Nobody calls that “artificial” selection. But when humans do functionally the same thing — choosing which stallions breed, castrating the rest — it does start to feel “unnatural.” Usually I find myself arguing that domestication is just a particular type of symbiotic relationship... but the natural vs. unnatural distinction is too useful to disregard even if I do genuinely think that humans are “just animals” in some important senses.

This whole mess is complicated by the way recent scholarship frames horse domestication not as an event where wild became domestic, but as an ongoing process of mutual adaptation. Humans modified horse populations through selective breeding and castration. Horses modified human societies by enabling pastoral mobility, mounted warfare, and long-distance trade. The result is a co-evolved system where asking “what’s natural?” is a bit like asking whether a coral reef’s structure is “natural” given that it’s built by organisms that also modify it. Yes? I guess? But “humans are unnatural!” can back you into some weird mental corners if you take it too far.

Mongolian horses live free on the steppe. They break through ice to find water in winter. They choose their own pasture. Their herders take a remarkably hands-off approach; there aren’t any stables, grain, or grooming. Yet the stallion leading a herd of mares and geldings is operating within a social structure that humans have been engineering for thousands of years. The geldings exist because a human decided their genes weren’t worth passing on. It’s decidedly unnatural selection!

I Hate Unclear Hedges

Look at Taylor’s original sentence again: horses “largely organize themselves in line with their natural social structure.” That word “largely” is doing a ton of work there. It’s a claim that the fit between free-range Mongolian horse herds and truly wild horse social behavior is close but not perfect. But reality has a much bigger gap than that, imo. “Largely” is not doing enough to make the reality clear.

Yes, the stallion-harem unit is genuine horse behavior. And geldings replacing bachelor bands is a human invention so old and so deeply integrated that it has become functionally invisible (because wild horse populations largely don’t exist anymore). But I think to call the total loss of bachelor bands “largely” natural is a mistake for the same reason that calling mature male elephants “largely” useless is wrong.

In the 1970s, conservationists relocated young elephants from Kruger National Park to Pilanesberg. They left the mature bulls behind. The adolescent males grew up, entered musth, and with no older bulls around to knock them out of it, went on a rampage that killed over 50 rhinos. When six large bulls were finally brought in from Kruger, the young males dropped out of musth almost immediately.

Maybe it’s the mother-of-a-young-boy in me, but I would bet that bachelor bands aren’t a footnote to herd structure. They’re where young males learn what they can and can’t get away with. They’re where they practice how to defend their herds, from other horses but also predators. Removing that system has implications, whether we replace it with geldings or just don’t think it matters if we leave some difficult old bulls behind.

It’s just that in the case of horses, those ‘consequences’ favor us and the horses for the same reasons that retarding the emotional growth of canines is how we get dogs, which have in a meaningful sense out-competed wolves as thoroughly as “civilized” men with “unnatural” things like email jobs and atomic families have outcompeted the raiding warbands of the Eurasian steppe.

I have complicated feelings about this. You?

Further Reading

• When Did Horses Transform Mongolians’ Way of Life? from Sapiens has some nice infographics and spans early domestication to Genghis Khan.

• Carolyn Willekes’ The Horse in the Ancient World (which I found via this review) might be my next horse read if I can get ahold of a copy from the library — it’s over $100 on Amazon!

It’s a great book tho, especially if you love passionate nerds talking about their subject of interest. It is essentially a love letter to teeth and the dentary-squamosal jaw joint — the hinge between the lower jaw and skull that defines mammalhood in some senses more than the mammary gland thing. This might sound like an odd focus for a 400-page book, but Brusatte makes a pretty good case that this single anatomical innovation cascaded into everything that makes mammals distinct: precise chewing, larger brains, nursing, better hearing, and eventually the ability to occupy nearly every ecological niche on Earth.

Classification Is Hard

One of the book’s recurring themes is how messy biological classification really is. Brusatte uses the dentary-squamosal joint to define mammals because it’s practical, even though most contemporary paleontologists prefer a “crown group” definition that traces back to the most recent common ancestor of living mammals. The crown group approach would exclude early creatures like Morganucodon from “mammal” status entirely, which matters for reasons I frankly don’t quite understand.

What I liked, tho, is that Brusatte is refreshingly candid about this tension:

Here I’ll be honest: in my scientific writings, I use the crown group definition. In a research paper, I wouldn’t call Morganucodon a “mammal,” but a “basal mammaliaform,” or a “nonmammalian mammaliaform.” As you can see, the terminology quickly becomes unwieldy.

This pragmatic approach appears throughout the book. Brusatte reminds us that “Nature doesn’t put labels on things, people do,” and different classification systems serve different purposes. I really like this kind of nuance — it’s rare to see a popular science book acknowledge that scientific categories are mostly just human constructs chosen for utility.

In that vein, one of the book’s revelations (at least for me) is how completely DNA evidence upended anatomical classifications of mammals. When molecular biologist Mark Springer and colleagues published the first DNA-based genealogies in the late 1990s and early 2000s, “paleontologists were shocked”:

Many of the relationships among placentals championed by Simpson disintegrated, revealed as illusions of anatomical convergence. Genes showed that pangolins are not closely related to anteaters and sloths, but group with dogs and cats. Bats are not next-of-kin to primates, but part of a larger assemblage with dogs, cats, and pangolins, plus the perissodactyls with an odd number of toes (like horses) and even-toed artiodactyls (like cattle).

This reshuffling is a great example of evolutionary convergence — unrelated organisms developing similar features because they face similar environments. Pangolins look like anteaters because both eat ants and termites, even though their genetic family-tree background is wildly divergent. Bats seemed primate-adjacent because both are small and agile, but from a bloodline perspective they’re really closer to dogs.

How Teeth Changed Everything

Anyway, mammals’ new jaw joint enabled precise, controlled chewing — something that’s apparently quite rare in the animal kingdom. Before this innovation, jaws were tenuously attached to skulls, limiting bite strength and precision. The dentary-squamosal joint, operated by newly divided jaw muscles (temporalis, masseter, and pterygoideus), could generate much stronger bites and focus that force on specific teeth at specific times.

Teaching my kids to take bites with incisors and chew with molars has been an adventure, but this is the thing that unlocked mammalian success. Precise chewing allowed mammals to extract more nutrition from food, and better nutrition supported larger brains. The skull cavities of early mammals show “huge cavities” that held much larger brains than their ancestors, with most growth at the front, creating the globular cerebral hemispheres characteristic of modern mammals.

Larger brains required more energy, which likely drove the evolution of nursing. Brusatte argues that mothers “must have started nursing early in mammal history, probably right around the time the first mammals like Morganucodon were scuttling around in the Triassic.” Milk provided a “nutritious, sustainable, readily available food source” to fuel energy-expensive neural tissue. Basically, mammals progressively lost their VIT genes — the genes responsible for producing vitellogenin, the egg yolk protein. As lactation and placentation evolved, egg yolk became dispensable, and these genes decayed into whatever the heck pseudogenes are.

Even mammalian hearing traces back to jaw evolution. As the jaw joint shifted, some of the old jaw bones became free to evolve into the three tiny bones of the mammalian middle ear. These bones, along with the bulla and petrosal, function as “noise-canceling headphones, allowing mammals to still hear exceptionally well while chewing.”

Size and Senses Matter

Cynodonts — the therapsid lineage that would become mammals — survived the end-Permian extinction while their cousins went extinct or dwindled. Brusatte says cynodonts “took the path of survival and domination.”

In this case, that meant getting small. Shrinking profoundly transformed their biology and evolutionary trajectory — they changed their growth, metabolism, diet, and feeding styles. They already had elevated body temperatures inherited from their therapsid ancestors, but next they developed full-on warm-bloodedness. They gave up size and strength to become specialists with keen senses and precise feeding, which worked out pretty well for them.

Early mammals made another significant sacrifice, essentially giving up color vision in exchange for enhanced smell, touch, and hearing

Brusatte notes that humans are “highly unusual among mammals” in our ability to perceive color, shared with only some of our closest primate relatives. Most mammals cannot see in color, which is why most have drab brown, tan, or gray fur. “Why dress yourself in flamboyant hues—like many day-living, sharp-eyed birds and reptiles do—if your mates or rivals cannot see them?” I knew that humans had better color vision than dogs and bulls (which can’t perceive the red color of the traditional bullfighting cape), but I didn’t realize how rare this was or why we evolved this way.

Turns out most mammals adapted to a nocturnal, scent-and-sound-based existence during the age of dinosaurs. And most mammal lineages never reversed those adaptations even after dinosaurs disappeared.

Some mammals did reverse other adaptations, though. The chapter on whale evolution describes how Egypt’s Wadi al-Hitan (Valley of the Whales) preserves dozens of whale skeletons from when the region was ocean floor:

Many of the skeletons are as pristine as ancient bones can be: enormous bodies preserved in perfect arrangement, with toothy heads connected to gently arching backbones, ribs sticking out sideways. If you follow the serpentine contours of the trunk, flattened flippers emerge from the shoulders, then the back vertebrae transition to the tail, and finally, when the tail has started to taper, some small bones appear, unmoored from the rest of the skeleton. A pelvis, and a leg.

These “walking whales” show the gradual transition from land mammal to fully aquatic whale, complete with vestigial legs. This find was a big deal because, “if anybody tries to claim there are no ‘transitional fossils’ or ‘missing links’ in the fossil record,” we can “tell them about the Walking Whales.”

The evolution of whales also involved sensory tradeoffs. Unlike the early mammals that sacrificed vision for smell, whales went the opposite direction — they “completely lost their sense of smell.” He said that “underwater, scent provides no advantage,” but when I first read this I wondered why sharks don’t have the same problem, since they famously detect blood from great distances. But it’s an apples-to-oranges comparison: sharks are fish with ‘olfactory’ systems completely separate from breathing, specialized for detecting waterborne chemicals. Toothed whales, by contrast, repurposed their nasal passages for echolocation and haven’t needed anything like “smell” to replace those functions.

Reality vs. Fiction

One of the other things I really liked about Brusatte’s writing is that his narrative sections were pretty grounded, especially compared to Tamed by Alice Roberts, which kicked off with a lengthy story that she explains is pure speculation that “could have” happened only after a lengthy scene walking us through how she thinks the first humans domesticated dogs.

The most memorable narrative scenes I remember came from the Ashfall Fossil Beds in Nebraska, which preserved a remarkable snapshot of various animals’ final moments. A volcanic eruption blanketed the region in ash, killing rhinoceros, horses, and camels (which I did not even realize existed in prehistoric America!?).

For example, in this moonscape of death, one hell hound made a final meal:

Haggard and hungry, it was about to give up before seeing the spread of rotting meat along the lakeshore. It walked up to a rhino and took a few half-hearted bites from its flank, spitting out ash as it gnawed. A last meal, before it lay down beside its prey.

Epicyon — and the actual scientific name really is “hell hound” — was a five-foot-long, two-hundred-pound bone-crushing predator that roamed Miocene North America. I didn’t realize those were “real” either, although I’m sure that the urban fantasy books I’ve read featuring hell hounds have remarkably little resemblance to the prehistoric canines.

Brusatte concludes the book with humans and our relationship to other mammals, including the possibility of mammoth de-extinction — currently as fictional as Jurassic Park (did you know it’s based on a book? I keep wanting to like Michael Crichton but keep bouncing off, how about you?). He’s confident mammoth re-creation will happen “and there will be a Nobel Prize in it for somebody.”

But he also acknowledges the ethical problems, and honestly I’m pretty skeptical of the whole project. Debates about the causes and extremities of global warming aside, “it will soon be much warmer than any mammoth ever experienced.” This is not a world in which they can thrive, even without humans hunting them. Where would we even put them, the Arctic to mess up that ecosystem even more? If we’re going to bring something back, I’d rather bring back something that has a chance at surviving, like the dodo or the thylacine.

The mammoth extinction itself remains controversial. I’d encountered the “blitzkrieg hypothesis” — the idea that humans hunted mammoths and other megafauna to death — before reading this book, and I’d assumed it was basically true. Brusatte convinced me otherwise, which might be the single most practically useful thing I got from this book; it saved me from confidently repeating something that’s not well supported. The evidence is thin, which matters because as he points out: “If we hunted dozens of large mammals to death, then the Near Time fossil record should be riddled with butchered mammoths and sabertooths with stab wounds.” The few examples of mammoth butchery are “far outnumbered by tool-marked bones of another large North American mammal: bison, a survivor!”

Brusatte favors a more complex explanation involving climate change, habitat disruption, and selective pressure on large slow-breeding animals. Bigger animals have lower reproduction rates and produce fewer offspring that take longer to develop. “Any forces that disrupt population structure and heighten juvenile mortality can thus topple these big-bodied slow breeders.” Not all of those forces are our fault!

Interesting Modern Mammals, aka Relevant Scientists

Speaking of fault, I want to talk about the people whose “fault” it is that we know all this stuff at all.

I don’t always enjoy the “human stories of science” sections in popular science books — I recently read a book about bats where the anecdotes about researchers felt off-putting rather than charming — but Brusatte’s work well. Walter Kühne, imprisoned by the Nazis during World War II, spent his detention assembling and describing the cynodont Oligokyphus. His meticulous work while imprisoned culminated in a 1956 monograph on the specimen.

Father Rigney had a worse experience. While studying a fossil mammal in China, the Communist secret police arrested him and imprisoned him for four years. Unlike Kühne, Rigney couldn’t continue his paleontological work in prison. The new government was “serious about purging China’s religious institutions.” After being freed through diplomatic channels, he eventually reunited with the skull specimen, which had been “secretly whisked away from the Communists.” But first he set aside the fossil to write his autobiography, Four Years in a Red Hell (and I believe it’s in the public domain, if you’d like an electronic copy of Rigney’s autobiography).

The obsessive dedication to research under impossible circumstances reminded me of The Perfectionists by Simon Winchester, which as I said in January was a great history of precision engineers: another group of people so consumed by their work that prison would barely slow them down.

The imprisoned paleontologists are hardly the only interesting human stories, tho. There’s the “Bone Wars” rivalry between Edward Cope and Othniel Marsh, which is one of those historical episodes that reads like fiction. Cope named more species than Marsh largely because the actual fossil hunters liked him better and gave him first access to their finds — a good reminder that people skills matter even in paleontology. The rivalry accelerated the field enormously, but also produced sloppy work and bitter feuds that lasted decades.

And when Darwin speculated that whales might have evolved from bears that swam with mouths open, skimming insects from water — a notion “so ludicrous he removed it from later editions of the Origin of Species” — Brusatte includes it not as a gotcha but as a reminder that wild theories that turn out to be wrong are a very important part of doing science. You have to be willing to be risk being wrong when you are trying to get closer to the truth.

Life Gets Grander Every Year

Brusatte ends with a reflection that captures why studying deep time matters:

The blue whale is not merely the largest mammal alive today, but the largest living animal, period. Nobody has ever found a fossil of anything bigger, which means that the blue whale is the all-time record holder, the heavyweight champion of the history of the world... It’s a simple but profound statement that bears repeating: the biggest animal that has ever lived is alive right now. Of all the billions of species that have lived during the billions of years of Earth history, we are among the privileged few that can say such a thing. How glorious is it that we breathe the same air as a blue whale, swim in the same waters, and gaze at the same stars?

This is the kind of perspective that makes this book such a lovely read. We tend to think of the past as grander, stranger, more extreme than the present. But the largest animal in Earth’s entire 4.5-billion-year history is swimming in our oceans right now. The age of mammals is still happening, even as we reshape the planet in ways that will determine which animal lineages survive into the next geological epoch.

Further Reading

If any of this sounds interesting, you can pick up a copy of “the best science book of 2022” The Rise and Reign of the Mammals. And for more on domestication and human relationships with mammals, see my review of Tamed by Alice Roberts. Roberts explores how humans selectively bred species, creating the billions of domesticated animals that make up fourteen times as much biomass as all wild mammals combined — a transformation Brusatte mentions briefly but doesn’t explore in depth because he is, at heart, a fossil guy.

Productivity

• examined Benjamin Franklin’s productivity notes and put Franklin’s personal note-taking and productivity systems in historical context.

• Oliver Burkeman, writing about treating your to-read pile like a river, not a bucket, says that the real problem is having too many genuinely worthwhile things vying for limited attention, so accept you can’t consume it all. It reminded me of my 2022 exhortation to stop feeling guilty, rebrand your to-read list as a filtered list of high-quality options available to you when you have time.

• wrote about his experiences switching from tech to being an electrician at 40. He seems really happy with his choices, but the most telling part for me was just how big a deal it is to be a guy who will reliably show up and legally be able to drive a car.

• Steve Magness explained some recent research on how negative pre-performance focus raises cortisol and hurts performance while positive feedback during preparation time boosts testosterone and improves outcomes. I’m not totally sure I buy it, but it sounds plausible.

• Brittany Solomon et al. found that having a conscientious spouse boosts your career. Partner conscientiousness predicted future job satisfaction, income, and likelihood of promotion, because conscientious partners handle more household tasks and model pragmatic behaviors. Perhaps the best productivity hack is marrying well (shoutout to my husband who did the dishes while I wrote this article!)

• I found this Quanta article on why there’s no single best way to store information really useful. It discusses how hash tables, heaps, and other data structures each trade off time, memory, and organization, and recent theoretical advances pushing the boundaries of what’s possible.

• wrote about how four minutes a day changed math in her classroom. Structured timed retrieval practice produced automaticity in math facts, reduced working-memory load, and drove large benchmark gains in third grade. I bet this works for adults, too.

AI

• Readout is a fully native macOS app providing a real-time, local overview of your Claude Code config with instant search across sessions, agents, skills, and repos. Free, no account required. Closed source but from the head of design of a fairly big company so I’m not overly worried about it being a horrifying malware bonanza.

• Harvard Business Review ran a piece arguing AI doesn’t reduce work — it intensifies it, based on research demonstrating that the faster pace, broader scope, extended hours of AI backed productivity leads to workload creep and risks burnout. It definitely resonated with me; I feel busier than I’ve ever been and missed writing an article last week because being able to code with Claude has been enabling me to get SO many things done that were previously blocked on other people.

• In a similar vein, wrote about the centuries-long shift to better jobs from a hopeful perspective; since Industrial Revolution, job quality has steadily improved. AI so far trims routine tasks but hasn’t reversed the long-term trend.

• had a nice article on the hidden cost of AI-generated feedback and how AI feedback may undermine learning by removing the social elements that help encourage kids to actually bother improving themselves.

• Mitchell Hashimoto shared his AI adoption journey. He moved from inefficient chat to reliable agent workflows by iteratively forcing agents to reproduce his manual work and engineering fixes so they stop repeating mistakes. Sounds pretty banal when summarized, but I found the walkthrough helpful.

• Hannah Stulberg has some nice suggestions for using Claude Code for everything, i.e. a personal assistant beyond just coding.

Science

• A carpal bone carbon-dated to the Second Punic War period provides rare physical evidence that Carthage kept war elephants in Iberia. Also in elephants, Simon A. Parfitt and Silvia M. Bello published an article on the earliest known elephant-bone tool in Europe: a cortical bone fragment deliberately shaped into a percussor for resharpening flint tools. It’s the first documented case of elephant bone used as a knapping hammer. Awhile back I learned that elephant long bones were systematically broken to make blanks appropriate for shaping tools in what amounts to a Neolithic factory efficient enough to drive Paleoloxodons to extinction, so I always perk up when I come across neat elephant bone history.

• examined how Sahelanthropus tchadensis moved — it’s a deep dive on what locomotion evidence from one of the oldest proposed hominins (~7 million years old) tells us about early bipedalism.

• LiveScience covered new evidence that Neanderthals made fire 400,000 years ago in England, which pushes controlled fire use in England back dramatically; the lead archaeologist called it the most exciting find in forty years.

• Senegal’s spear-wielding savannah chimps have heat-adapted behaviors that mirror possible early hominin strategies. Fongoli chimps soak in pools, and get cool in caves. The females (!) craft and use spears to hunt bush babies.

• The Guardian reported on the Floreana giant tortoise returning to the Galapagos after nearly 200 years. Yes, they are a keystone species whose grazing maintains open habitats and distributes native seeds, but also they are apparently incredibly useful to old-style sailors because they can store fresh water in their bodies for months. I should note that Darwin does not agree that they’re delicious, but even so, they’re a big deal. Eden Undone by Abbott Kahler (which I started but haven’t finished yet) mentions logbooks recording thirteen thousand tortoises taken by whalers, one surviving in storage for two years.

• argues that people are confused, maladapted apes that are nonetheless highly strategic. We often end up choosing tribal or self-interested ignorance because incentives, not just misunderstandings, drive social dysfunction.

• A Nature trial found that timing immunochemotherapy by time of day changed immune cell dynamics and improved outcomes in lung cancer patients, which has really interesting implications for medical treatments if it replicates...

• The Lancet flagged a long-scrutinized report of an infant allegedly poisoned by opioids in breast milk, amid new allegations of falsified toxicology data. I don’t normally share modern politics-ish controversy takes, but this one hit close to home and I am extremely grateful to the guy who doggedly tracked down this appalling fraud.

• Lin Bian’s paper on toddlers and ingroup loyalty shows that context-sensitive social reasoning develops very early. Toddlers are monsters, and preschoolers not much better, but it was still a pretty interesting study.

• Smithsonian Magazine had a ton of neat articles that I read this month: these small, stubby-armed dinosaurs may have been egg-thieves, shovel-tusked elephants had surprisingly species-specific feeding styles, I did not realize the extinct camels of North America even existed, there was once a giant carnivore that ran on hooves, and rove beetles apparently steal ant scent to infiltrate colonies.

Literature

• Jonathan Muth looked offered some nice graphs of where all the starships went. Classic sci-fi title keywords (space, Mars, planet) peaked in the 1950s-60s and have steadily declined, while fantasy keywords (dragon, magic, witch) surged after 2000.

• Sweden is bringing books back to classrooms. Reading physical books out loud is how I spend most of my evenings these days, and it’s sort of... reassuring? to see that even the educationally vaunted Nordic countries went astray a bit there but are bringing it back.

• This YouTube video on what fantasy gets wrong about sacred groves talked a lot about how sacred groves are socially constructed, managed, contested spaces… not pristine primeval forests.

History

• Bret Devereaux also wrote a ton of interesting things this month. History nerds should definitely check out his overview of ancient Mediterranean mercenaries, this piece on ancient migrations, and his analysis of warfare in Dune. Bonus: don’t forget about my rant about how Fremen walking into the desert to die are violating their cultural norms around water.

• A small reminder that Carthage dominated Mediterranean trade and seemed likeliest to control the region before the Punic Wars ended badly for them; international power dynamics are weird and can change faster than you’d think.

• Anne F. Broadbridge’s chapter on women in steppe society shows how steppe women ran large autonomous camps, managed resources and personnel, and exercised political power as managers, regents, landholders, and diplomatic marriage-brokers. Their hospitality and kin networks were essential to Mongol military success.

• reviewed a paper on how Henry VIII’s Dissolution of the Monasteries fueled the rise of the gentry. Land reform after 1536 commercialized property and differentiated Britain’s economic trajectory, though Kedrosky argues the paper overstates the link to industrialization since monastic lands were concentrated in the agrarian south and east, not the industrial northwest.

• had a neat piece on how courtship transformed masculinity — European courtship norms empowered female choice, transforming marriage from arranged/kin-controlled unions into companionate, monogamous partnerships.

• Mary Anne Smith woke London workers by blasting dried peas at their windows as a paid human alarm clock. The practice persisted into the 1970s until affordable electric alarm clocks made it obsolete. It was a nice reminder of the kinds of jobs that have gotten outsourced to mechanical devices in the last few hundred years.

• had a deep dive on how smiles signaled everything from demonic possession and drunkenness to nobility at various points in history, and the “uncanny smile” now functions as a mask signaling inner displacement.

• wrote a deep dive on the secret history of knocking on wood because his daughter prompted him to think about the cultural evolution of gestures. It’s a cute story with some interesting data visualizations and some good points about the kinds of things humans know but don’t write down.

ICYMI: My February Articles

• I wrote an article about the importance of staying aware of the implicit, difficult-to-record layers of your workflows, with some reflections on Extracting Value from the Process Layer of Your Notes. Nowhere near as popular as the piece on how Claude + Obsidian got a level up, which now has more likes than anything I’ve ever written on Substack.

• I also reviewed a book about the history of coal, which I’ve since learned got the details a bit wrong when it comes to the relationship between the British navy and coal ships. Feedback like that is a huge part of why I write in public, so huge shoutout to for the correction :)

• The most popular link from last month’s edition of Neat Stuff I Read was Curating a Journaling Ecosystem by . If you missed it, check it out!

& as always, if you read something interesting that you think I might be interested in, please reach out! In the meantime, did you know that this week is my ten year anniversary for blogging online? I archive the really old stuff behind a paywall to avoid feeling obligated to keep everything up to date with new research and tech, but I went back and looked at some of those early pieces and it’s fun to see how long I’ve been writing about things like religion & war in myth cycles, the great man paradox, and the importance of ancient African history.

Here’s to another ten years, and a big thank you to all of you for your encouraging words over the years — I definitely couldn’t sustain this newsletter if y’all didn’t actually read it and write in and discuss these essays and ideas with me :)

Jain’s main point was that most of our tools model what exists. Notes, highlights, documents, tags, folders, links between ideas. But they don’t model how things actually happen. They don’t capture the sequence of actions, the patterns of your process, or the temporal chain of “I read this, then I annotated that, then three weeks later I connected it to something I’d forgotten I’d taken notes about.”

Jain calls this the difference between a knowledge graph and a context graph. And after sitting with the idea for a few days, I think the distinction is useful enough to be worth stealing.

Most PKM Tools are Knowledge Graphs

If you use Obsidian, or Notion, or Capacities, or Roam, or really any note-taking app with linking, what you’ve built is some version of a knowledge graph. Most of them literally display this in a graph view, but even ones that don’t have nodes (your notes) and edges (your links between them). You might also have metadata — tags, properties, dates. If you’re fancy, you have an index or a map of content (or perhaps several of each, like me).

Such a knowledge graph tells you what you know. It answers questions like “what are all my notes about trophic cascades?” or “which books connect to my article about marriage in the ancient world?” It models the state of your notes at any given point.

This is useful. I’ve written thousands of words about why making and organizing notes is valuable and I meant every word. I’ve built my entire research workflow around the idea that connections between ideas are more valuable than the ideas in isolation — particularly in the sense of comparing moments across time, like locust plagues in the ancient world vs. 1900s Palestine vs. modern America, or the diplomatic role of women in various cultures.

But a knowledge graph is inherently static. My vault does have information about how I came to know things — I have git backups, and I link to sources, which is part of why the interlinking is so valuable. What I tend to do with the information is write articles, which end up in another folder. But the graph doesn’t capture the process that connects reading to writing, or tell me where that process breaks down.

What a Context Graph Adds

In Jain’s framework, a context graph takes the knowledge graph and layers on process. Instead of “this ticket exists,” you get “when a top-priority incident happens, someone opens a ticket, an engineer investigates, they escalate if necessary, they document the fix — and here’s how long each step usually takes.” Actions become first-class entities. Who did what, in which apps, in what order, and with what effect.

For an enterprise, this makes sense because you want AI to automate workflows. GitHub’s former top guy has built an entire new development platform intended to capture AI context better, which is frankly way over my head. But these concepts (as I understand them) should port well to individual knowledge work, where the problem is slightly different: you don’t want to automate your thinking, you want to understand it well enough to support it.

In my ideal world, a personal context graph would capture stuff like: “When I read a long nonfiction book, I highlight for weeks, then do nothing for a while, then process all the highlights in one frantic burst, then slowly spin out articles over the next few months.” Or: “I tend to abandon notes in my inbox when they sit longer than ten days — but if I touch them within three, they almost always get processed.” Or even just: “My best writing happens when I’ve recently re-read my own annotations, not when I go back to the original source.”

None of my current tools capture this. My Obsidian vault can tell me what I’ve written and when, but it can’t tell me how — the actual chain of reading, annotating, connecting, drafting, revising. It can’t tell me which processes produce my best work, or where I consistently drop the ball.

The only way I will exercise is if someone whose opinion I care about is watching, and I don’t have to think about any of hte pieces. It took me decades to learn that. It’s not my favorite thing about myself, but knowing it has been immensely valuable for my 2025 goal of developing an exercise habit.

Value Lives in the Process Layer

Jain makes this point for enterprises: “systems of record capture decisions, but the real work happens in meetings, chats, emails, and docs.” The same is true for individuals. Your notes capture decisions — what you decided was worth keeping — but the real learning happens in the spaces between. The re-reads, the connections you make at 11pm while brushing your teeth, how you find the good stuff, why you ignored the bad stuff, the slow accumulation of related highlights that eventually tips over into an article idea. Most of that doesn’t get recorded anywhere.

I’ve been circling this problem for a while without having a good name for it. When I wrote about how Claude + MCP solved my organizational problems, part of what I was describing was Claude’s ability to infer process from state. When I told Claude to “go through the files in this folder, figure out the patterns, and write a script to put information like A into location B,” what I was really asking it to do was reconstruct my process from the artifacts I’d left behind. It did a reasonable job. But it was working backwards from the end product, not from actual traces of what I’d done.

Working backwards from artifacts means Claude has to guess at my intent. Working from actual traces — a log of “she highlighted this passage, then wrote this annotation, then three days later searched for this term, then created this note” — would let it understand what I was actually trying to do.

What Personal Context Graphs Look Like Now

The closest thing most individuals have to a context graph is scattered across multiple unconnected tools.

Reading history in Reader (or Goodreads, or whatever) captures some of the temporal dimension. You can see when you read something, how long you spent on it, what you highlighted, whether you reviewed it. There’s metadata like “date saved” and “date last updated” that offers hints about your process. Version history in Notion or Obsidian captures when you modified files. Sometimes, the pre-filled search terms that count as ‘search history’ capture what you were looking for and when. Your browser history keeps track (sort of) of what you read and in what order.

But none of these are connected to each other. The reading traces live in one database. The writing traces live in git. The search traces live in your browser or your filesystem. The thinking traces — if they exist at all — live in diaries and annotations, scattered across different sources.

Before I read the context graph post it didn’t even occur to me to think about that sort of information, really. I mean, I know that when I read a nonfiction book quickly I’m more likely to actually finish it and actually write a review, but I don’t have hard numbers. I suspect many of you don’t either. But between local-first apps with plugin ecosystems, AI that can read your files, and tools like MCP that let different programs actually talk to each other… the pieces exist. As far as I know, nobody’s assembled them yet.

From “What” to “How” in Practice

Jain’s core argument is that we need to shift from modeling what exists to modeling how change happens. For personal knowledge management, I think this translates into looking at the efficacy of our methods and habits moreso than how tidy the first-class information (or even metadata) is. When did you last review how many days typically pass between highlighting and processing? Between processing and writing? Between writing and publishing? I certainly hadn’t, until I started poking at this.

And it’s not just timing. Links between notes are static — they tell you that two ideas are related, but not the order in which you encountered them, or the path you took from one to the other, or the detours along the way. Obsidian’s graph view shows connections, but doesn’t elevate the age of a document, or how many times it’s been read or edited since creation. What would a “process view” show? I genuinely don’t know, but it’s fun to think about.

Glean builds process models by analyzing many users doing similar work. You only have one user — yourself — but you have probably years of data. I have git commits, highlight timestamps, file modification dates. I could, right now, probably reconstruct a rough timeline of every article I’ve ever written and identify patterns in how long each phase took. There were years I only wrote one article, and months where I never missed a deadline. The reasons why (social obligations, pregnancy issues) live in my head, but I never really wrote them down.

But what helps me succeed in my goals is probably the most important information my notes could possibly tell me!

The part of Jain’s framework I find most interesting for individuals is what they call closing the loop. When their AI agents run, the traces from those runs get fed back into the context graph. Successful patterns get reinforced; failure patterns get flagged. In my own Claude Code setup, I have built a strong habit of updating memory and skills and rules every time something goes awry.

The same principle should apply to personal workflows — when you try a new process and it works, capture that fact somewhere explicit. When something fails, capture that too. Right now, most of us rely on meatspace memory and a vague sense of what works for us, even when we manage a strong daily log or diary habit.

What Would It Take to Build One?

What I’d want — and I think other PKM enthusiasts might want too — is something that watches the flow across all of these tools and surfaces patterns... in a way that doesn’t feel like being constantly monitored by a creepy corporate surveilance net. “Here’s what your last month of knowledge work actually looked like. Here’s where your process broke down. Here’s what your most productive weeks had in common.” sounds amazing!

Glean can (probably, I dunno, I’ve never used it) build this for enterprises because they control the connectors and the data layer. For individuals, the most promising path is probably some combination of local-first tooling (like Obsidian’s plugin ecosystem) and AI that can reason about the traces you already generate. Claude Code already sits in a position where it can read my notes, see my git history, track my archive of accomplishments, and query my Reader highlights. What it can’t (yet?) do is build a persistent model of my process from all that data. What I’ve been trying to do instead is build a habit of saying “go look at what I changed, compare it to before, and gain some insight from how I did that” — because it’s easy, even if it’s manual. I don’t trust an automated flywheel, however much everyone raves about Clawdbot.

I prefer manual command invocations, coupled with a regular report about what’s happening. I keep hoping someone will figure out the tooling — or that I’ll have some extra time on a weekend to try hacking something together — but for now it’s still a gap.

The Gap Between Knowledge and Action

Separately, there’s a deeper implication of the context graph framework that I want to emphasize. Jain distinguishes between knowledge (what exists) and process (how things happen). But there’s a third layer that I think matters even more: intent. Why did you do what you did? What were you trying to accomplish?

In an enterprise context, intent is usually obvious — resolve the ticket, close the deal, ship the feature — or, more clearly stated: profit. In personal knowledge management, intent is more varied and harder to pin down. Sometimes I’m reading because I want to write an article. Sometimes I’m just curious. And sometimes — honestly, more often than I’d like to admit — I’m killing time and happened to find something interesting. These different intents produce different processes, and a good context graph would need to account for that.

This is why I’m skeptical of fully automated approaches. The tools that try to “organize your notes for you” tend to fail because they can’t distinguish between intent categories. They don’t know whether a highlight means “this is important to my research” or “this was a funny quote I wanted to send to my friend” or “I’m giving feedback on a friend’s book and do not ever want this book resurfaced again” — sure, I can flag that manually, but it’s a pain. Context graphs won’t solve this problem entirely — you still need to leave breadcrumbs about why you did something, not just what you did. Tags, annotations, metadata, and (of course) folders will continue to matter.

But I keep coming back to the shift from “what” to “how.” I’m not sure what to do with that yet, and I kind of hate the idea of writing everything down so an AI can tell me how to optimize my life even more. So far, AI is not reducing my work, it’s intensifying it, and I’m still trying to figure out the best way to avoid burning out chasing the dream of being able to do so much more than I ever could before.

So if you have any great ideas about how to leverage automated processes for that, please let me know in the comments!

The book covers coal from prehistory through the Romans to the modern climate debate, organized roughly by geography: Britain first, then America, then global. She’s not neutral — she clearly wants the reader to be worried about the environmental implications of coal power — but she’s honest about the good that came with the bad (during the parts of the book I actually found interesting, i.e. everything before 1990). As she puts it: “Failing to recognize both sides of coal — the vast power and the exorbitant cost — misses the essential, heartbreaking drama of the story.”

The Deep Past

Coal beds were formed during the Carboniferous period, when dense plant matter fell into oxygen-poor water and failed to decay normally. The forests of that era were dominated by lepidodendron trees — giant scale trees with soft, pithy interiors. As long as water was plentiful, their internal cells stayed expanded and kept the tree erect. Without water, these proud giants would have weakened, sagged, and finally collapsed under their own weight. It’s a funny mental image: prehistoric forests that could just... deflate.

Instead, when the seas rose and fell during glacial cycles, these forests were repeatedly buried in water and sediment. Because oxygen couldn’t reach the buried plants, the plants only partly decayed, leaving behind black carbon. Over geological time, the peat compressed into coal, locking away millions of years of solar energy underground. To give you a sense of her style, Freese puts it more eloquently than I usually bother to:

It wasn’t just the forest’s carbon that ended up trapped in the coal, but the energy it had accumulated from the sun over millions of years. Instead of dissipating with the plants’ decay, that energy was tucked away into the dark recesses of the earth, at least until the amphibians crawling across the forest floor evolved into creatures capable of digging it up.

She hammers this point about how we’re using up millions of years worth of energy very quickly pretty often.

Rome: Coal as Jewelry

When the Romans invaded Britain, they found outcrops of a “velvety deep black mineral” that they carved into jewelry and exported back to Rome. The Romans also burned coal at Minerva’s shrine in Bath, so they knew it was flammable.

They called it gagate, which became “jet” — as in “jet black.” I had no idea that was the origin of the phrase, or that “jet” is a special, dense form of coal. Apparently many Romans couldn’t tell the difference and were probably wearing plain coal around their necks.

My father once put coal in my stocking at Christmas, and I think I still have it in a baggie somewhere. The idea of trying to turn it into jewelry is a little strange, but I guess a lot of ancient status symbols were pretty weird. Modern ones are too.

Medieval English Coal

By the 700s, the English were burning coal not for heat but because they believed its smoke could drive off serpents. Coal’s early history in England is surprisingly mystical — people thought it was a form of living vegetation and suggested manuring coal seams to help them grow.

The medieval coal story mostly struck me as a story about institutional control. The majority of the coal along the River Tyne was held by the Catholic Church — specifically the bishop of Durham and the prior of Tynemouth — and worked by their serfs. The first recorded act of violence in the coal trade was between merchants and monks. Town merchants, many of them former serfs who’d bought their freedom, tried to muscle in as middlemen between the Church’s mines and the tradespeople who actually burned the stuff: blacksmiths, lime burners, brewers, and salt makers.

Eventually, the merchants won:

The town merchants pled in their defense that if the monks traded coal without going through the merchants, not only would they lose their cut, but the king’s tax on coal could not be collected. The merchants won, and the prior was forced to tear down his wharf.

One issue with coal exploitation in this era was that the Church leased mines on such brief terms that nobody had an incentive to invest in expansion. Freese argues that if the mines had stayed in church hands, the industry might never have scaled to meet demand. We’ll never know, because Henry VIII’s divorce from Catherine of Aragon required splitting from the Catholic Church (not least of which because the Pope was under pressure from Catherine’s family). As part of the Protestant Reformation, Henry dissolved the monasteries and transferred their coal holdings to private owners who were incentivized to think bigger.

This is one of those pivot points in history that makes you dizzy if you think about it too long. This is why I don’t write alternate history, as much as I enjoy the occasional book in the genre (1812: The Rivers of War by Eric Flint is my favorite). In a real “for want of a nail“ sort of way, a roll of the genetic dice reshuffled property rights in a way that made the Industrial Revolution possible. Freese doesn’t belabor the point, but I really want to read that book now.

The coal trade grew around Newcastle, where thick seams were exposed above the water line was a crucial advantage. What the English called “sea coal” (oddly enough for such a terrestrial product, but the term stuck until the 1600s) could be mined without dealing with flooding. Other regions had coal, but Newcastle’s geography made it commercially viable.

Freese doesn’t go deep into whether the Industrial Revolution could have happened elsewhere, but Bret Devereaux’s “Why No Roman Industrial Revolution?” makes a strong case that the specific chain of coal availability → steam engines → textile production was unique to Britain. See also this discussion of why the steam engine wasn’t invented earlier.

Coal’s Health Costs

Freese is at her most passionate when describing coal’s health consequences. One story involves Queen Eleanor of Provence, who visited Nottingham in 1257. She (probably) promptly fled because she couldn’t stand the heavy smoke of sea coal. At the time, coal was used only by blacksmiths and lime burners — nobody would burn it at home. But as forests shrank and wood became scarce, and eventually, domestic coal burning became unavoidable. London’s famous fogs were coal fogs. Visitors regularly developed respiratory symptoms that cleared up as soon as they left the city.

The fireplaces and chimneys had to be made much narrower for coal fires than they had been for wood fires to provide the proper draw of air (an architectural change that would promote the employment of very young children as chimney sweeps).

That parenthetical hit me. I knew the child labor market got pretty dark during the Industrial Revolution (it’s a major part of the high school US History curriculum), but I didn’t realize that the chimney sweeps being children was due to chimney sizes changing. I kept thinking of the chimney sweep song scene from Mary Poppins, which is one of my favorite movies to watch with the kids when everybody is sick.

Coal smoke also destroyed tapestries within a few years, making them ugly and smelly, so wainscoting replaced them. The aesthetics of the English home were, in a meaningful sense, designed around coal… and not everybody was happy about it:

Even in modest English homes, chimneys had become common by the mid-1500s. Some lamented this development, because they credited the wood smoke that had filled homes in earlier years with both hardening the timbers and protecting the health of the inhabitants.

It’s not like they had a great grasp on the health implications of all this, back then, although doctors did tell people to go get some fresh mountain air to get well. Now a book like Heidi (which holds up pretty well even as an adult!) sounds insane, but back then “get out of Frankfurt and up into the Swiss Alps where you can drink some fresh goat milk and breathe fresh air, and you will get healthy and well” probably was true.

Manchester under the industrial haze was pretty grim. Tocqueville described the sun as “a disc without rays.” Babies raised in industrial darkness developed rickets in epidemic proportions — it became known internationally as “the English disease.” In some neighborhoods, every child a doctor examined showed signs of it. As late as 1918, a government report found that half the population in Britain’s industrial areas suffered from rickets.

The national security implications for the Army were as big a deal as scurvy was for the Navy. During the Crimean War, 42 percent of urban recruits were rejected for physical weakness, compared to 17 percent of rural recruits. And these were young men who had already been screened by local recruiters — the truly unfit never made it that far.

His unquestioning faith in society’s ability to use technology and coal to meet its needs independently of nature was widely shared by the new industrial powers. That faith allowed the captains of industry to cut much of the industrial population off from the sunlight of its own day because they were unable to believe that humanity has a biological need for sunlight that runs bone-deep.

That line about sunlight running “bone-deep” is literal — rickets is a bone disease caused by vitamin D deficiency, and vitamin D comes from sunlight. The coal fog was so thick people in industrial Britain — already pale-skinned due to the difficulty of getting enough sunlight in the northern latitudes — not only couldn’t breathe, their bones were shot.

Down in the Mines

In the seventeenth century, English coal miners and their families were “commonly referred to as a separate race of humans” and “increasingly ostracized by society.” Medieval peasants and artisans, whatever their disabilities and trials may have been, were not segregated from their neighbors to anything like the degree to which the coal miners of the seventeenth century were considered other. Over time, the isolated miners developed distinct habits and speech.

But if English miners had it bad, Scottish miners had it worse. In Scotland, whole families were bonded for life to a coal mine in a form of industrial serfdom. Men hewed the coal; women and children hauled it to the surface. Families were regarded as property and sold with the mine if it changed hands. If they ran away, they could be “tortured in the irons provided only for coal miners and witches and notorious malefactors.”

The dangers of coal mining appear throughout the book, but Freese gives particular attention to the invisible killers: the gases.

Miners dealt with three types of “damp” (from the German dampf, meaning fog or vapor). Choke damp is mostly carbon dioxide, which forms when carbon in coal oxidizes. In high concentrations, it snuffs out life the same way it snuffs out a candle. White damp is carbon monoxide, a product of incomplete combustion that appeared mainly after fires or explosions. Though carbon monoxide is odorless, historical texts frequently describe white damp as having a floral scent.

But the worst was fire damp — methane gas that appeared more frequently as mines got deeper. If there was only a small accumulation, the bearer of a flame might merely be knocked flat and singed. Larger accumulations exploded.

Some mines employed “firemen” whose job was to burn off the fire damp before it reached explosive concentrations. The fireman would cover himself in soaked rags, creep on his belly along the mine floor, and raise a long stick with a lighted candle on the end to where fire damp was suspected of collecting. The gas would flame along the ceiling while the fireman pressed his face to the floor until it passed over. Ken Follett describes this much more vividly in A Place Called Freedom. It’s my favorite of his many books, although I suppose A Night Over Water was really good too. Pillars of the Earth ranks a distant third, for all that it’s his most famous work.

Follett’s novel follows Mack McAsh, a Scottish coal miner, fireman and son of a fireman who died in the mines. He’s a strong, smart, conscientious guy, and so he tries to get better treatment. He of course falls in love with a beautiful but tragically vulnerable heiress (who also ends up in Virginia, married to an incompetent jerk who is put in charge of a plantation he badly mismanages). It being a book, he has girl problems and cop problems and just all kinds of problems. He’s eventually sent to colonial Virginia as an indentured servant for his crimes (involvement in a riot, but I forget the details).

Spoilers: they run away together, but the first chunk of the book is a really stark and educational look at the horrid conditions of Scottish coal miners. Though it’s been years since I read it nothing Freese talked about here was too much of a surprise — A Place Called Freedom came flooding back to me and to be honest I remember the details from that book better than what I learned about in Coal even though I read Coal much more recently. Like I’ve said before, I find fiction really valuable for learning.

Anyway, eventually miners like Mack started using animals to detect dangerous gas levels. Canaries came to replace mice because a poisoned canary would topple dramatically off its perch — much easier to detect in a dark mine than the “pinkness in the snout” and “crouching” displayed by a poisoned mouse.

In some pits, miners even experimented with bringing phosphorescent fish down to light their way. Apparently this didn’t fully meet their needs, though it’s one of the few details I wasn’t already familiar with.

Industrialization

In preindustrial England, tough economic times caused people to marry later, lowering birthrates. After awhile, coal became too useful to continue ignoring the soggy seams. The Industrial Revolution reversed the fertility trend: cheap factory jobs meant young people could marry earlier, and birth rates rose. Meanwhile, today, we’re seeing falling birth rates in wealthy countries. The mechanisms are different, but there’s something disquieting about watching the demographic lever get pulled by different flavors of technological change.

The big change for industrialization was getting water out of coal mines. Large mines might need fifty or sixty horses to keep water-raising engines moving night and day, and the cost of feeding the animals and paying workers to handle them was enormous even with the awful serfdom coal miners endured. This pumping challenge is what drew the Royal Society’s attention in the 1600s. They focused on atmospheric pressure and vacuum creation. Denis Papin (who had earlier invented the pressure cooker, which he called his “new Digester or Engine for softening Bones.” I definitely prefer “instant pot” as a name...) found that steam could create the vacuum needed to harness atmospheric pressure.

Thomas Newcomen built on this work to create the first practical steam engine for pumping water from mines. He’s often overlooked in historical accounts, but Freese quotes those who remember his work with reverence, calling it “the most wonderful invention which human ingenuity had yet produced.” Without Newcomen’s engine, the deeper coal seams would have remained flooded and inaccessible.

As coal flooded the markets and became more common, it revolutionized the British military in more ways than one. Coal powered the navy’s ships, yes, but coal ships were considered the “chief nursery” for English seamen. They were sturdier and had larger crews than fishing vessels, making them more useful when commandeered for military service (which happened more often than I’d have thought before I read about the HMS Wager, which inspired my October article about press gangs). The coal trade and the navy were symbiotic; in wartime, coal sailors were press-ganged into service so frequently that they demanded hazard pay just for being in the coal business.

Coal powered steam engines. Steam engines powered blast furnaces. Blast furnaces produced cheap iron. Cheap iron built more steam engines and more ships. Each made the others cheaper and more productive. By 1830, Britain produced four-fifths of the world’s coal. By 1848, it produced more iron than the rest of the world combined.

American Coal

Meanwhile, the Puritans had advertised America’s forests as a selling point for emigration. Francis Higginson wrote that “a poor servant here may afford to give more wood for timber and fire as good as the world yields, than many noblemen in England can afford to do.” For the English, who had been freezing and choking on coal smoke, unlimited firewood was a deeply appealing promise.

Ironically, America also held the world’s richest coal deposits — “a coal field half the size of Europe” beneath those eastern forests. Pittsburgh became an early industrial outpost, making iron tools for westward settlers. In a gold rush, sell shovels. In an AI hype cycle, sell clawdbot installation services.

Anyway, the logistical absurdity of early American geography was pretty memorable. For awhile, it was easier to sail coal across the Atlantic from Britain than to haul it over the mountains.

We figured it out, though it was dicey for awhile. When supplies ran out in Arcola, Illinois (due to the 1902 coal strike) three hundred citizens — including two bank presidents, two ministers, and a police officer — surrounded a broken-down coal train and started shoveling coal into their wagons. One of the bank presidents “kept a careful accounting of the amount taken by each person so that payment could later be made.” In the most Midwestern way possible, they were very polite thieves, heh.

Then there was the situation with the Molly Maguires, (allegedly) a secret organization of Irish Catholic coal-mining terrorists in Pennsylvania’s anthracite region. At first I was annoyed the book didn’t really talk about what the Molly Maguires were trying to accomplish, but even the Wikipedia article is pretty hard to parse. The sense I got is that the Molly Maguires had goals similar to the burgeoning coal miners’ unions, but they were parallel organizations without even as much overlap as the Civil Rights movement had between MLK’s followers and the more militant followers of Malcolm X.

The interesting part here was that Franklin Gowen, president of the Reading Railroad (which I had not... entirely realized was a real thing), hired a Pinkerton spy to infiltrate the group. Gowen’s private “Coal and Iron Police” then arrested the suspects. Gowen himself served as special prosecutor at their trial, using testimony from his own spy, gathered by his own detectives, presented to a court in his company’s territory.

It would be hard to find another proceeding in American history where a single corporation, indeed a single man, had so blatantly taken over the powers of the sovereign.

I suppose it’s always nice to see that our modern political dramas aren’t unique.

Anyway, that trial resulted in twenty executions — and vigilante activity killed even more Molly Maguires. Whether the Molly Maguires were actually terrorists or simply labor organizers framed by railroad interests is still contested, but what’s clear is that Gowen wielded extraordinary power over both investigation and prosecution... because of coal.

For twenty years, Gowen was as famous as Carnegie or Rockefeller. Then the Reading Railroad went bankrupt — twice — under his leadership. J.P. Morgan’s syndicate seized control and shoved Gowen into a ceremonial counsel role. In December 1889, he was found dead of a gunshot wound in a Washington hotel room; whether it was suicide or murder is still debated. The anthracite industry he’d fought to monopolize declined through the twentieth century, and the Reading Railroad itself went bankrupt for the last time in 1971.

Contemporary Parallels

Not all the health side effects were unwaveringly grim, though. Some were also funny:

By the 1970s the acid had seeped into thousands of shallow wells in southern Sweden, corroding the copper pipes and contaminating the tap water with copper sulfate. The fair-haired Swedes who washed in the contaminated water found that it tinted their hair green, sometimes as “green as a birch in spring,” as a Swedish researcher described it in 1981.

The book was published in 2003, so the fervent climate politics gripes about the minutiae of Clinton-era legal battles at the end felt pretty irrelevant. Given that she’s an environmental lawyer I can’t begrudge her for including them, but candidly I skimmed most of it. And to her credit, she tries to be balanced:

There will be benefits, of course, as with most great changes. Some species will thrive, there will be fewer deadly cold snaps, heating costs will decline, and in many places the growing season will lengthen. Crop and wood production may well increase over the next few decades in the mid-latitudes if warming remains moderate. This is thanks in part to more CO2 in the air, which has a fertilizing effect that for many plants will help offset some of the other climate stresses.

Still, Freese’s description of Manchester’s factory workers “forming something new to the world: a large class of people whose lives were shaped, and in many ways reduced, by machines” was the most interesting part of the modern-day stuff from a 2026 perspective.

As LLMs take the tech world by storm, I tend to think we’re probably closer to a major technological upheaval impacting job type availability than we’ve been in awhile. In the time of the Luddites, coal power substituted for adult muscle and machinery substituted for adult skill. But widespread, permanent unemployment didn’t follow the loss of power for weaving guilds, and ultimately the Industrial Revolution led to a lot fewer famines and crises.

Freese occasionally makes gestures toward how things could have gone differently — “we might have found a more gradual and humane path out of it than the one we took” — without ever seriously engaging with what that alternative would look like. I haven’t found anyone who has, honestly. Lots of people can explain that the Industrial Revolution was brutal. I’ve never seen a plausible alternative history where it wasn’t. Have you? If so, please tell me, I want to read it (bonus points if the inflection point is Henry and Catherine having a boy!)

Yes, we probably burned through our civilizational starter fuel getting to our current position, but now is objectively the best humanity has ever had it. Whether we’ve done enough with it to secure the future of our species indefinitely — sustainable energy, space capability, whatever “enough” means when it comes to hedging against the fall of modern civilization — is one of those questions that matters enormously and that nobody can answer yet.

What makes Coal worth reading isn’t any single revelation but the cumulative effect of seeing how one resource reshaped everything it touched: architecture, childhood, class, empire, health... even the sky. If you’re interested in this kind of focused historical lens — how a single resource or commodity reshapes politics, trade, and daily life — you might also enjoy Banana: The Fate of the Fruit That Changed the World (which I liked but haven’t gotten around to reviewing), or Salt: A World History (which I haven’t read yet). If you’ve already read Salt, let me know if it’s as good as people say 🙏

Productivity

• article about the Stamina Gap was simultaneously terrifying and validating. He talks about how reading long novels builds cognitive endurance, and how sustained concentration skills are becoming increasingly rare (some would say elite) skills. I am good at both of these things, but this sort of thing is part of why I’m so determined to read one nonfiction book a month this year. I do not want to lose the ability to concentrate on hard problems, and the best way to keep my mind sharp is to exercise it.

• shared her approach to curating a journaling ecosystem because she was worried her “phone was making her stupid.” She ended up replacing doomscrolling with analog journaling to reclaim creativity and intentional time.

• (who, along with his wife, writes one of my top five favorite newsletters) reviewed How to Solve It by George Pólya. It distills four core problem-solving steps (understand, plan, execute, reflect) into useful heuristics.

• A philosophy undergrad started daily workouts to avoid “becoming lost in the world of signs and forget the things they signify.” As something with an undergrad philosophy degree who struggles with exercise, I’m really trying to convince myself to think this way.

• A PhD candidate in economics at UC Berkeley argued that ideas aren’t getting harder to find, and research productivity hasn’t fallen. Apparently firms produce as many breakthrough patents per R&D dollar, but market/allocative inefficiencies mean those ideas no longer translate into broad productivity gains. This feels like something worth paying attention to from a “caring about improving the world” perspective.

AI Tools

• Lance Martin shared how he steers Claude Code using a /TODO command that finds #TODO(Claude) comments in his code and builds a plan. I do something pretty similar although I usually just do %%CC: note %% as my formatting. Anyway, more interesting was how he discussed “Fingerspitzengefühl” ― the intuitive feel for steering agents via Plan Mode, file referencing, and targeted TODOs. It’s the first time I’ve seen the term in the wild since I wrote my review of Certain to Win by Chet Richards. I genuinely think that developing this “intuitive sense” of what’s possible is the most important thing I can be working on right now, for reasons Martin Alderson outlines in his article about how two kinds of AI users are emerging.

• Boris Cherny (Claude Code’s creator) discussed how he uses it. Eyad shared a complete Claude Code tutorial. Basically, folks emphasize the value of thinking through things, and iterating over careful plans with curated context before sending prompts. Use compacting/clearing, run instances in parallel locally, use slash commands, subagents, offer verification methods, and provide examples for when the AI gets stuck. I’m not a programmer but I’ve personally managed to run 5 terminal “channels” in parallel and it felt pretty natural, like maintaining a couple of conversations in Slack or Discord at once. AI is finally worth using for a wide variety of white collar tasks; it even helped me with my taxes (yes of course I double-checked, I double-check my tax professional too).

• Klöss wrote a guide on how to improve at prompting. Don’t treat prompts as polite requests, treat them as code commands. Ordered context, clear constraints, set role definitions, structured output formats, and canonical documents all help make prompts more effective.

• Ryan Carson explained how to make your agent learn and ship while you sleep ― he suggests a nightly loop where the agent reviews threads to extract learnings into a controlling markdown file. I do a variation of this; I add to my memory file throughout the day, and have a “good-night” prompt that checks on a couple of places I update and compiles the new information where it belongs.

• Shruti spent a week researching Clawdbot, an autonomous AI that runs on a persistent server (like a Raspberry Pi or Cloudflare worker, although some people are using a Mac mini). It’s intended to execute tasks 24/7, but requires significant setup for complex workflows and can get pricey if you use APIs instead of riskier choices giving it its own CLI coding tool subscription. I got one working on a $5/mo Cloudflare worker but it was a pain and I’m nervous about the security implications, so I haven’t leveraged it much beyond learning how Puppeteer works (badly for what I need :P).

• Steve Yegge introduced Gas Town, an orchestrator that automates and swarms massive Claude Code agent workflows using tmux and a heartbeat system to run persistent, durable “convoys.” It sounds like industrial-grade chaos for advanced users only, and I have not tried it, but I’m seeing this “heartbeat” thing so much that I did implement a couple of cronjobs for repeated tasks I don’t want to have to personally trigger. I think Yegge is right that this is probably the future, so I’m trying to stay aware of it even if I’m not quite ready to dance on the bleeding edge.

• I’m more at the level of… did you know you can stash your prompt in Claude Code with ctrl+s to save drafts and auto-restore them? Here’s a straightforward guide to the bash commands LLMs use most often, so you can understand what they’re doing a little better.

Science

• Apparently parasitic worms use static electricity as a tractor beam. Researchers discovered hookworm larvae can harness static charges to leap onto hosts. The worms generate charges through movement, then ride the electric field gradient to their target — a previously unknown mechanism in parasites. Probably the neatest thing I read last month.

• My son and I have really been enjoying this “Insane Biology” series on YouTube. We started out listening to the audio stream neat video about octopus biology on his beloved Yoto (here’s a neat DIY version that is always-offline). Octopuses have 500 million neurons (2/3 in their arms, not their brain!), can change color in 200 milliseconds despite being colorblind, and represent a completely independent evolution of intelligence.

• Dan Davis History has a great video on how ancient salt mining transformed prehistoric Europe. Neolithic and Iron Age communities centered settlements around salt springs, using ceramic “brickage” and evaporation to produce salt.

History

• Harvard Magazine revisited a 1884 cannibalism at sea case that still anchors law school ethics debates (which were my favorite part of law school). This case basically reshaped Anglo-American law by rejecting necessity as a defense for killing an innocent to save others.

• looked into governance lessons from the Constitutional Convention and determined that small working committees plus secrecy and careful press signals were key to producing compromise. It reminded me a lot of L. E. Modesitt’s points in his gaslamp series The Grand Illusion. They’re more political theory than rollicking fun, but I still liked them and you might too.

• In January I finished reading 1177 BC by Eric Cline (who is very nice on Twitter and has very fun ties), which explains how the Sea Peoples are probably not really responsible for one of the first multi-civilizational collapse. I respect Cline as a scholar, and really enjoyed Chapter 5, but it’s more of an introduction to the region/era than a deep dive. Bret Devereaux happened to write about the Late Bronze Age Collapse recently as well, and in some ways I preferred his version because it was shorter, more targeted, and had much better maps.

• Naval Gazing is starting a book club read-through of Morison’s The Two-Ocean War, one chapter per week starting Feb 4. If that’s your sort of thing, go join them, Bean is great.

Modern Instutitions

• Matt Lakeman is my favorite travel blogger bar none, and his Notes on Afghanistan (which involved several Taliban encounters) were as fascinating as always. He has great photos, great book recommendations, and lots of great stories.

• This deep dive from into how to address a Russian came up during a discussion with some of my Russian-speaking friends. It broke down details about first name, patronym, family name quirks and discussed different ways of signaling precise levels of familiarity and respect.

• Years ago, wrote about how Tyler Cowen is the best curator of talent in the world because he consistently identifies undervalued high-potential talent across a wide variety of fields. I have no interest in VC, but I do care about hiring practices and surrounding myself with awesome people, and I really liked the way the article explained Cowen’s unique perspectives on this. I suspect off-the-wall methods like this will end up more popular in the coming years as the AI-vs-AI resume battles spiral out of control.

• had a similarly fascinating profile of a16z as power brokers. The bet is that owning capabilities and narratives lets them invest bigger and shape industry norms. It’s not the sort of thing I want to do, but it’s definitely the sort of thing I want to understand in the same way I care about weather patterns and local school board trends.

• For similar reasons, Samuel Days reviewed Why Nations Fail, and declared it “an above-average book, which I consider damning with faint praise for a pair of Nobel Prize winners.”

ICYMI: My January Articles

• I wrote a review of The Perfectionists by Simon Winchester, which was a really good history of precision engineering. I enjoyed the guy who was so obsessed with iron that he built an iron desk, and loved learning how jet engine turbine blades operate at temperatures higher than their melting point by using ancient Greek-style lost-wax casting combined with microscopic cooling holes.

• How Locusts Cause Famines and Shaped the Middle East is probably one of my more interesting academic deep dives, judging from what friends have said. The article discusses swarms from biblical Palestine to 1874 Nebraska to modern East Africa. I focused mostly on Aaron Aaronsohn, the WWI-era agronomist who fought locusts in Ottoman service and because of that experience ended up spying for the British out of Zionist fervor. He is probably the basis of Liet-Kynes from Dune, except his problems were trickier.

• Claude + Obsidian Got a Level Up was my most popular article in ages. Like I said in the intro, Claude Code finally clicked for me. I connected to a Telegram bot so it can send morning reports, fixed my RSS plugin for Obsidian, set up automated fine-grained git commits, have a much-improved research flow, and refined how I process notes from books I’ve read. Basically, I’m not trying to do things faster, I’m trying to do them with less attention so they actually get done. The article includes anecdotes from my offline/analog personal life that help show how how I think lets me leverage AI more effectively.

• The most popular link from last month’s edition of Neat Stuff I Read was nobody knows how large software products work by Sean Goedecke. If you missed it, check it out!

Stay tuned for next week’s review of Coal: A Human History by Barbara Freese and as always, please do share this or any of my articles with a friend who might be interested :)

But recently the word came down from people I trust —1 people with skin in the game — that the coding agents had turned a corner and that Claude Code was the perfect mix of powerful and accessible for someone like me.

I tried it out and hot damn y’all, it feels so good. The UI feels so intuitive, like an old-school MUD. The most annoying thing — the permission management — had good solutions on the issues pages. The scripts it spits out work. It made me an entire new Obsidian plugin in one go, with literally one bugfix (it wasn’t properly stripping white space in the token). As someone who has painstakingly built Obsidian plugins before, I assure you this is much better than my code usually turns out on the first try.

Iterations actually fix the stuff I didn’t articulate well the first time, and the way it collates data from different sources — stuff I used to have to click through long loading screens to get before — is saving me so much time.

It’s not magic and I’m not worried about being replaced at my job. But it churned through my entire vault — 15 million words! — overnight and came up with a tidy index file that helped me find stuff I haven’t had a chance to connect up since I got pregnant. It cleaned up files I haven’t been able to touch, and fixed a glitch in my RSS plugin that was causing ugly character encodings to get scattered about in URLs and file names. It tweaked old outdated things to match my new metadata preferences, and it did it with pull requests that didn’t risk destroying data, it remembers to git commit after every change (better than me!) and it does an incredible job of figuring out the incredibly obscure technical problems that plague me throughout the week.

If you have been following along with me for years you know I don’t hype things just because people are hyping things. But Claude Code finally has made AI a core part of my processes instead of just a thing I use sometimes as an extra source or bonus spell checker or quicker way to reformat files.

Setting Claude Code Up in Obsidian

I was genuinely surprised at how easy the terminal plugin was to install for Obsidian. In Obsidian, I went to community plugins, searched for “terminal,” and installed the Terminal plugin by polyipseity. Then I clicked the “open terminal” button on the left-hand side. That’s it.

There’s a dedicated Claudian plugin (subtly different from the Claudsidian solution people), but the Terminal felt a little higher fidelity to how I’m used to doing things, and a little simpler to understand. Plus, Claudian looks great but honestly I don’t think I can live without plan mode, which the readme says it doesn’t currently support. Plan mode is nice because it asks questions, really thinks things through, and can be trusted not to do dumb destructive things.

But Why?

One criticism I see of LLM tools is that people will say “well I could do that by hand, why do I need a bot to do it for me?” And for a lot of people, this is true. They can spin up a bash script that works faster than Claude — but I can’t. Even I can run multiple searches in Obsidian faster than it takes an agent.

But these days I’m not generally trying to do things faster, I’m trying to do them with less attention. All these searches and tasks run in the background, which means they actually get done. When I had to actively sit there and click through things, half of it never happened because something else more important would come up, or I just didn’t feel like doing grunt work just then.

It’s very similar to how I felt about Obsidian plugins, honestly. Back then, I could feel all these different ways of optimizing and improving processes just on the tip of my fingers and I just needed to do them. I built a concatenation plugin, I made a theme. I got a lot out of that — including a great new job with Readwise! — but I had definitely plateaued in terms of what optimizations could actually make my life better, because learning to code was a commitment I did not really have time for.

Now, though, I’m excited again about all the ideas I have for improving my life. Some of them will end up not getting used as much as I hope (am I going to finish this webserial? I do hope!). But I am sure I will find new ways to be more productive by reducing the amount of context switching and waiting on loading bars I need to do. I’m already finding better ways to batch my tasks. Making smarter to-do lists that include more context and don’t require me to learn Reverse Polish Notation. Suddenly, I can actually make use of the APIs I’ve always known existed. The sky is the limit once again — and I don’t need to bother my friends to get stuff done.

Back when I first learned about Eisenhower matrixes (thanks again to the Obsidian community!) I was utterly befuddled by the “delegate” box. Who was I supposed to be delegating tasks to? I was a stay-at-home mom, not a general or CEO.

But now that I have kids, I delegate all the time. My six(!)-year-old can handle the laundry, so I leave that for him. My two-year-old loves clean-up time, so I hold off until she’s home. My babysitter likes to tidy things (“it’s better than doomscrolling Instagram”), so I can ask her to reorganize the kids’ closet while they’re napping, instead of doing it myself. My husband isn’t afraid of heights the way I am, so I ask him to change the stairwell light bulbs when they go out.

Building the habit of delegating — and using language clear and precise enough for a teenaged girl who doesn’t live in my house to understand — has really helped with leveraging LLMs.

My favorite kind of problem is a solvable problem. I know a lot of people who just brute force or deal with their issues, but I try to notice pain points and deal with them. This isn’t just an AI thing, this is a life thing. For instance, I was working on a puzzle with my son, which I often do, and I realized that one of the big problems we have is being able to see the little guide picture. Some of my friends call this cheating, but my son is six, so whatever. Anyway, normally I lay the poster thing out on the table, but then we don’t have enough room for all the pieces when we’re first getting started. I had this epiphany that I could put it on the wall, with a clip. And yeah, yeah, it’s a little janky — a perfectionist (like the guys I studied when reviewing The Perfectionists by Simon Winchester) would have a nicer solution here — but this gets the job done and is nice and easy to reference.

This is not going to 10x my puzzle productivity. But it makes the process nicer and saves some frustration.

Build a habit of noticing things that frustrate you! Instead of stoically tolerating them, go for a walk. Try to figure out and brainstorm your pain points. Let your mind relax while noodling on the topic of how to improve your situation.

I do all my best work outside.

An Example: The Telegram Bot

This is one reason I wanted an easy quick capture system for Obsidian that felt natural, like chat. When I am out for a walk I hate opening up the GitHub app and finding my notes to edit, and I’ve always had issues with quick capture + Obsidian Sync because I make big folder changes to my vault all the time. Sync under those circumstances is hard. So I asked Claude what I should do and it suggested Telegram because it has a good bot system. I set up a Telegram bot (which was indeed super easy) and asked Claude to build me an Obsidian plugin to copy messages to my inbox — it worked after one bugfix. I know I could just use a script, but Obsidian’s plugin graphical interface makes a little more sense to me. I don’t want to worry about automated scripts running in the background of my computer. I would have to go and learn where all that stuff lives before being able to disable it — whereas I’m already comfortable with Obsidian plugins.

Most of this article was drafted in Telegram messages over the course of the last week. I just dictate into my phone using the microphone on the google keyboard. Some people prefer fancy AI transcription services, but I need to see the words appear to remember what I already said, and this method is free :P

And yes, I know Obsidian’s plugin ecosystem already has a Telegram plugin, but I don’t like to use daily notes and the one Claude built for me is simpler to use and customize according to my preferences.

I’ve always been better at knowing what can be built than knowing how to build it. Asking an AI for something at about the complexity I would be willing to tackle is like asking for help with a project in Discord. That is about the level of complexity Claude excels at, and I have a lengthy backlog of those. Like this cool website it built for my Beauty & the Beast in SPAAAAACE! webserial, Maven and the Border Lord (which automatically updates whenever I post to the decentralized Instagram-alternative I use, but I’ve been having some trouble getting Midjourney to generate what I want. Maybe I should try nanobanana :P).

Why Claude

I’m all in on Claude (which you may remember I was loving back in July, too, because it let me organize my book review notes much better) because Anthropic seems to be leading in the stuff I care about. The harness they’re building makes sense to me, and I like being able to look inside the box at the files that control it. I think I’m more in their target audience than the other LLMs I’ve tried, and I hate switching everything over to stay on the cutting edge when a new model or tool drops.

Also Claude Code is cheaper than the API via Cursor, and the models diverge a bit so getting good at one seems like a better call than optimizing for everything. My friend is trying to get them to do more custom complex stuff so he uses both but it’s a lot of effort (and money). I don’t only use Claude, though. Readwise Reader uses OpenAI models for Ghostreader, which I use all the time because Readwise’s development team has done way more work with prompt engineering and vector databases than I could ever dream.

As for the privacy concerns? There isn’t anything private in my vault, so I don’t really care about Anthropic access. I mean, most of it is on my public slipbox. I keep my truly private information analog or in a Bitwarden locker. Also, I trust Anthropic a bit more than some of the other big AI players: their business model makes sense to me and doesn’t seem like it would benefit from dark patterns or grand betrayals.

A big value of my notes is not really remembering stuff per se, but rather having them in a format that is easy to share and provides all the context that would be annoying for me to rearticulate. This is a reason I write articles; they help keep me from repeating myself. So most of my notes are intended for sharing in some form anyway, and if Anthropic decides to source me in an LLM response, I’ll be as delighted as when Google does.

Terminal Practice with Games

Some folks I’ve talked to are a little intimidated by the terminal. Want to practice in a low-stakes way?

Go play Lusternia. Yes, it’s in maintenance mode, but it’s a fantastic game with incredible depth of lore and wonderful stories, and it’s all done in a terminal-like interface. Games are the best way to learn. Not fake games, real games. Getting stuff done in Lusternia when I was a kid required scripting (MUDs are how I learned what little I know about coding) and in the age of AI... trust me, you’ll be fine.

Incidentally, Lusternia is a social game, and I admit that I haven’t played it in a couple of years. Nothing prepared me for this moment better than that game, and if any of you end up playing, let me know, because selfishly I would be delighted to get back into it.

IDEs vs Obsidian

You can use the terminal plugin directly in Obsidian if you want to use Claude. But if you’re messing around with dotfolders (where Claude’s settings and slash commands live) or want to look directly at your Claude commands, having a “real” IDE is nice. I personally use Cursor, which is a fork of Visual Studio Code, but mostly just because I didn’t want to take the time to figure out what weird UI stuff I did to my VSCode, and I happened to have it installed because I was testing something for the Readwise MCP server. Cursor also does some neat stuff with RAG and vectors that I don’t understand but assume will come in useful at some point.

Obsidian has by far the better “normal” file editing (as opposed to code editing) experience when working with Claude, and it not only has plugins but you can also make your own to do whatever you want and interact with it with a graphical interface with toggles and stuff. Honestly there isn’t much you can’t do with Obsidian. It’s crazy powerful.

I bounce back and forth between Obsidian, Cursor and the external terminal (which Obsidian can launch with a command palette option if you have the Terminal plugin installed). The main thing to keep in mind for both is that large file changes kind of require a restart because the cache gets stale. In my experience Obsidian handles this a little better.

Little Tips for Claude Code + Obsidian

• You can put your Obsidian vault into a “top level” folder, then when the terminal opens, use cd .. to navigate “up” one level in the tree. This is the Wikipedia page for cd which is essentially the only terminal command I have memorized. But if you get into this habit (or make it your default terminal behavior, ask Claude how!), you can put other folders (like git repositories for code) next to your Obsidian vault, and have the same Claude skills and permissions for all of them, just up one level. Some people prefer clean bifurcation, but personally I like to have access to all my stuff as I’m iterating through tasks.

• Treat skills (or commands, personally I prefer commands and they work almost the same) like functions; don’t repeat yourself if you can avoid it, you can have two commands call another skill and then just keep the one skill updated with whatever troubleshooting steps you develop. Modularity is key, imo.

• Install git (I used GitHub Desktop because the command line version freaks me out sometimes) and tell Claude (in your CLAUDE.MD file) to commit after every change. You don’t need to set up GitHub; you don’t need to push your changes anywhere, but having a commit history means you have version control which with AI making changes, you really want even if you’re monitoring and approving every change (which swiftly gets old). Claude is excellent at reading commit history and rolling back if you need to. The extra paranoid can use the Obsidian git plugin to commit regularly.

• Any time you correct Claude, tell it to write down directions (to a relevant skill file or to your CLAUDE.md directions file) for avoiding that mistake again. In fact, put that in your CLAUDE.md file too, and set up a file (in the .claude folder or in your inbox, as you prefer) for logging conversations, problems and corrections. Claude does a lot of logging automatically when it compacts, but it can be helpful to have it put that stuff where you actually look, so you don’t forget you can review it later.

• If you’re using APIs to fetch stuff and need it to be thorough, explicitly tell Claude to keep hitting the API with a subtly different query until it is sure there isn’t any more; services like to cut you off after a window but there’s often more if you change your query. “The beatings will continue until morale improves” is how I sometimes need to treat Claude when it screws something up because of a badly done API — just keep trying from different angles, tell it to spin out subagents, and clear context and try again. It’ll get there in a way that just wasn’t true 3-6 months ago (which is why you haven’t seen me saying much about AI beyond the article about how Claude + MCP solved some of my organizational problems and the one detailing my method for making electronic notes in the age if AI — both of which are a little outdated now, because this is moving so fast. There really has been a phase change since Christmas).

Knowledge Management vs Knowledge Utilization

The worst part of personal knowledge management is that you spend time managing the organization of your notes instead of doing stuff with your notes. Fiddling is sometimes valuable of course; you get more touches of the content, which acts as a sort of spaced repetition and refreshes your memory. But as with many automation vs. ‘doing it by hand’ situations, there’s an 80/20 thing going on. When I was pregnant (and nursing)... I got to a point where note maintenance was just not getting done. I was not getting the most out of my efforts. Fundamentally, I have more time to read and annotate books in bits and drabs than to write essays (also in bits and drabs, thanks Telegram!). Leaving all the unsorted notes around until I can get to them and process them manually and memorize them is not my goal.

My goal is to learn things, integrate them into my world view, and get my extra touches on the content by talking about it with my friends.

I can’t do that if the notes are waiting in an inbox waiting for my ✨ personal touch ✨ — which is what they had been doing before Claude, unless I went in and fetched them out myself to write an article with.

Obsidian is valuable because I love having a hand curated pile of sources I already know I’m familiar with and have personally vetted, when I do have time to sit down and write up my thoughts, I’d rather write essays on how locusts cause famines and shaped the Middle East than reformat my YAML for the sixth time.

Further Reading

I’m not gonna pretend to be an expert here (any more than I’m an expert Obsidian plugin developer :p) but here are some resources that helped me figure out Claude Code

• Kent writes a lot about how he uses Obsidian with Claude Code.

• This is an incredible hub of resources for using Claude Code for project management, by someone who also uses Obsidian.

• This take on Claude Code for non-developers helped solidify my understanding of how it all works; it hallucinates less, for one thing.

• has fantastic tips for working with asynchronous coding agents and is incredibly level-headed about the LLM landscape.

• This article does a great job of breaking down all the nitty-gritty of how Claude Code works.

• Damian Player has a step-by-step guide on using Claude Code as a non-technical person that goes into more depth.

• Here’s a tutorial from a pro that breaks down best practices for using Claude Code, like the importance of planning and thinking things through, and exactly why a good CLAUDE.md file matters.

I will probably include more in next month’s “Neat Stuff I Read” edition, stay tuned!

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Honestly, at first I sat up and took notice mostly because he reminded me of Liet-Kynes from Dune. But the challenges he had to overcome were frankly more difficult (and more interesting) than the Imperial Planetologist’s. Yeah, he had to figure out how to grow food in the desert and make it livable, but he also had to deal with locust plagues — which are a lot harder to cope with and avoid than sandworms. And coordinating with the British was a lot harder than the Fremen independence plan.

How Locusts Work

So, locusts aren’t their own species or whatever, it’s more like a phase stage of the grasshopper lifecycle that only happens sometimes. This is one of the reasons that sandworms are easier to deal with than locusts — sandworms are pretty much always around, so you get used to them. With decades between locust swarms it can be hard to really adapt your habits in a way that prevents the next crisis. It’s a long-term boom and bust cycle. I think of it as being sort of similar to how most people don’t plan for the stock market to crash, or a government to go off the rails. Those tend to be generational crises, and it’s difficult to leave opportunities on the table being paranoid about a generational crisis… like locusts swarms. Devastating locust swarms are pretty rare, it's not like a weevil infestation or whatever.

In the words of my two-year-old: but why?

Well, as explained in this great article featuring photos he took himself (always a plus!), certain grasshopper species can transform from solitary, harmless creatures into swarming, crop-devouring plagues. The technical term is “phenotypic plasticity” — the genes don’t change, but behavior and physiology shift dramatically in response to the environment. You see this a lot when you look at how an octopus responds to different water temperatures. But I digress.

For locusts the trigger is touch. When grasshoppers get crowded together — usually because drought has concentrated them around shrinking food sources — physical contact triggers serotonin production. The same neurotransmitter associated with mood in humans flips a switch in grasshoppers, and suddenly they want to be around other grasshoppers. They change color, breed faster, and start traveling together.

This adaptation probably evolved around 8 million years ago, as North Africa shifted from tropical forest to desert. Locusts that could switch between solitary and swarming modes could opt for settling down when food was plentiful, then mobbing up and migrating when it wasn’t.

This sucks for agricultural humans, though.

Locusts preferentially eat grasses and grains — exactly the crops that agricultural societies depend on for the bulk of their calories. Hunter-gatherers and mixed-subsistence communities fare better because their food sources are more varied. Tubers (like the amazing potato, star of The Martian by Andy Weir) stay underground where they’re safe, and locusts mostly ignore fruits and nuts.

But a society that depends on grass and grain is screwed, even if they’re pastoralists who mostly get their food from herding. The cows and sheep need to eat something, and they can’t get to it before the locusts do.

In the Middle East

The locusts of Exodus were the eighth plague, arriving after the frogs and flies and livestock disease but before darkness and death:

The locusts came up over all the land of Egypt and settled on the whole country of Egypt, such a dense swarm of locusts as had never been before, nor ever will be again. They covered the face of the whole land, so that the land was darkened, and they ate all the plants in the land and all the fruit of the trees that the hail had left. Not a green thing remained, neither tree nor plant of the field, through all the land of Egypt.

The Book of Joel treats locusts as instruments of divine judgment:

What the cutting locust left, the swarming locust has eaten. What the swarming locust left, the hopping locust has eaten, and what the hopping locust left, the destroying locust has eaten.

Given the biblical references, it makes sense that locusts show up in places like Palestine, the Levant, Israel, and whatever else you want to call that chunk of land along the eastern Mediterranean.

So let’s get back to Aaronsohn, the real-life Liet-Kynes, and the locusts he ended up tasked with defeating in Palestine.

Aaron Aaronsohn was the agronomist who discovered wild emmer wheat — the genetic ancestor of modern wheat — in 1906. (I wrote about wheat domestication in my review of Tamed by Alice Roberts if you want more on how we got from wild grasses to bread.) He also helped establish modern-day Israel.

He was born in 1876 in a small Romanian town, the son of a Jewish grain merchant. After Romania’s independence from the Ottomans, Jews were effectively blocked from citizenship, schools, and most professions. When Aaronsohn was six, his family joined a mass Jewish exodus. Instead of going to America1, they sailed for Ottoman Palestine and settled with ~250 other Romanian Jews on barren land near Haifa, naming it Samarin. The land was terrible, and most of them were merchants with almost no farming skills; within a year they were so poor they had to pawn their Torah scrolls.

The early Zionist agricultural colonies in that area were effectively run under a baronial, almost serf‑like system financed by Baron Edmond de Rothschild. Settlers worked Rothschild’s land under his agents, in a tight, paternalistic, “feudalistic” regime.

For Aaronsohn personally though, this system worked out: at sixteen he was picked by Rothschild’s agents and sent to France to study agronomy and botany at the elite Grignon Institute, all expenses paid. On his return, he was supposed to be a kind of educated overseer/technician for Rothschild’s estates—the baron’s agricultural “man” rather than a free farmer.

But Aaronsohn was a Zionist visionary who believed his agricultural expertise could make a Jewish homeland in Palestine possible, and he poured a ton of effort into that instead. He ended up as known across the Middle East as the leading agronomist, was head of a sophisticated experimental farm at Athlit, and ended up well‑connected with Ottoman officials (from years of lobbying and advising). Anderson puts it thusly:

It was Aaronsohn, with his encyclopedic knowledge of the region’s flora and soil conditions and aquifers, who first appreciated how it might practically be accomplished, how the Jewish diaspora might return to its ancestral homeland and prosper by making the desert bloom.

Huge Liet-Kynes vibes.

The war complicated his plan, of course. And though I don’t know much about the Ottoman front (my semi-detailed knowledge of Ottoman history ends roughly when Roxelana died), I do know that they controlled the area around Jerusalem — which ends up being part of why the fall of the Ottomans led to the creation of modern-day Israel in all its complicated glory. But before that quagmire, in 1915, the locust swarms, so vast they blocked out the sun, descended on Jerusalem, stripping every green thing from the land and blinding farm animals who couldn’t close their eyes fast enough. It happened at a pretty rough moment — the middle of WWI, with tens of thousands of Syrian farmers conscripted, animals and equipment requisitioned, and ethnic tensions cranked up to the max.

And from March through October, locust swarms kept coming. Some were measured at a mile wide and seven miles long.

So Aaronsohn approached the Ottoman military governor of Syria, Djemal Pasha, with a plan. Their first meeting was tense: Aaron used the occasion not just to recommend modern anti‑locust techniques but to lecture Djemal about the army’s brutal requisitions and the ruin they’d caused. Djemal cut him off with: “What if I were to have you hanged?”

In a clever retort, alluding to both his considerable girth and to his network of influential friends abroad, the agronomist replied, “Your Excellency, the weight of my body would break the gallows with a noise loud enough to be heard in America.”

In the end, Djemal appointed Aaronsohn as High Commissioner of the Central Commission to Fight the Locusts tho.

The position came with extraordinary powers. All males between fifteen and sixty were required to collect and turn in twenty kilograms of locust eggs. Aaronsohn and his (Jewish, which complicated things given their social status at the time) team were given permission to move freely throughout the region, making detailed maps of the areas they surveyed.

But in addition to the flagrant discrimination, they had to deal with indifference and sabotage from Ottoman bureaucrats and army officers, as well as religious fatalism in Arab villages, where locusts were called djesh Allah—“God’s army”—and resistance was seen as pointless at best, impious at worst.

The swarms continued through 1916, and according to historian Zachary Foster’s research, the attack destroyed 60-100% of summer and autumn harvests depending on the crop, plus 10-15% of the winter wheat and barley. Between 100,000 and 200,000 people died of starvation or starvation-related diseases in the year after the locust attack alone. By 1918, the death toll in Greater Syria reached an estimated 500,000 — a comparatively brutal civilian casualty rate.

Mount Lebanon was hit worst. The Great Famine of Mount Lebanon took “an estimated 200,000 lives, a third of the region’s population, forcing another third to emigrate.” It wasn’t just the locusts, of course. Like I’ve said before, famines are rarely about just one thing. The Allied naval blockade didn’t help, the Ottoman requisitioning of food sucked when combined with the locust devastation, and Djemal Pasha deliberately prevented grain shipments from reaching the region (which is like the third time I’ve heard of this sort of thing leading to famine). But the locusts are what I’m focused on today.

The locust campaign made Aaronsohn realize that even in an existential food crisis, bureaucrats remained lazy, predatory, and sectarian. While he had once been a “staunch supporter of the Turks,” he ended up doubting that Jews could safely survive under Ottoman rule at all.

So along with figuring out how to deal with the locusts (his team was able to prevent a second locust spawn, and yes that’s totally a thing… see below), Aaronsohn’s people mapped Ottoman troop concentrations, fortifications, rail lines, and water sources. The anti-locust campaign became the foundation for NILI, the spy ring that would later pass critical intelligence to the British. I’m not an expert on Israeli history and didn’t finish the book, but I suspect this contributed a lot to the British backing the creation of modern-day Israel.

In America

North America had locust swarms too. documented how one swarm that hit Nebraska in 1874 covered 198,000 square miles and contained an estimated 12 trillion insects — the greatest concentration of animals ever recorded, according to Wikipedia by way of the Guinness World Records.

The Nebraska State Historical Society says the locusts devoured entire fields of wheat, corn, potatoes, and fruit. They also gnawed on curtains, clothing hung out to dry, wooden tool handles (attracted by the salt from sweat), and leather saddles and harnesses. Residents described swarms so thick they blocked the sun for six hours at a stretch. The Biblical “blocked out the sun” levels of plague swarm is probably not hyperbole, although I think I heard that phrase first in the context of arrows in the (genuinely not great, seriously that oracle scene was uncomfortable) movie 300.

The Rocky Mountain locust caused $200 million in damage to western agriculture in the 1870s — over $100 billion in today’s money. Army officials warned that 10,000 Nebraskans faced starvation. The federal relief effort that followed, organized by the Nebraska Relief and Aid Association, was one of the early examples of government agricultural assistance — historian Steven Kinsella argues these plagues started the relationship between agricultural producers and government that continues today. Nebraska even passed a law requiring all males between 16 and 60 to spend at least two days fighting locusts during hatching season, with a $10 fine for refusal.

Since America wasn’t in the middle of an existential war and the government did the opposite of blocking aid from reaching the area, things turned out a lot better than in Israel. It also helps that we spent a lot of time and effort converting prairie grassland (with bison, fires, and beavers doing their thing in places critical to the locusts’ lifecycle) into cropland. Basically they got less and less common over time. The last specimen was collected in 1902, and the IUCN formally declared the species extinct in 2014.

It’s not all good, I guess. The Eskimo curlew, a shorebird that may have depended on locusts as a food source during its spring migration, went from abundant to critically endangered around the same time — last seen in 1939.

East Africa, 2020

It’s not like locusts are done making headlines, though.

wrote about the 2020 locust crisis in East Africa, which was the worst in decades. Ethiopia, Kenya, and Somalia were hit hardest, with swarms threatening the food supply for tens of millions of people.

Back in 2018, two cyclones hit the Arabian Peninsula. Then there was heavy rainfall. The moisture enabled three generations of successful locust breeding in just nine months, increasing their numbers roughly 8,000-fold.

The response was complicated by COVID-19 lockdowns, supply chain disruptions, and coordination challenges across multiple countries. There’s also the pesticide paradox — spraying can reduce locust populations, but it makes surviving locusts unsafe to eat, eliminating one traditional coping mechanism for locust swarms. And humans weren’t the only ones who switched to eating locusts when the locusts ate everything else, so other alternate sources of food died — like the Eskimo curlews I mentioned above, although for different reasons.

Also, as with 1915 Israel, this happened in a region already stressed by conflict, drought, and displacement. I’ll say it again: locusts don’t cause wars or famines by themselves. It’s rarely about one thing. Locusts are just one of those little pinpricks that can push a precarious situation over the edge.

Like that time a big ole ship crashed into the Key Bridge. We know which little technical failure was the “real” reason it happened, but fundamentally the ship failed because of a million other maintenance failures — remember how I hammered that in my piece about infrastructure fragility that focused on canals and bridges? Locust plagues don’t really bother America (even though we totally do have locust-swarm-forming grasshopper breeds still) because we have better management. The closest thing we get is cicadas, which are mostly just neat — has a great piece on how the 2024 double-brood emergence was the first since 1803. The biggest problem from that was people freaking out and pouring insecticide on everything, which killed some birds and other wildlife.

’s work on famine and societal collapse goes a bit beyond the stuff I’ve written about. His point is that once you’re in a famine, it tends to reinforce itself — the conditions that caused the crisis make recovery harder. Locusts are one of many ways to arrive at that tipping point.

I wonder how Liet-Kynes would have dealt with such a swarm.

Further Reading

• The Library of Congress has a small exhibit on the 1915 locust plague with photographs from the American Colony in Jerusalem — the images of soldiers collecting eggs and swarms darkening the sky really put some of those biblical passages into context.

• Tablet Magazine’s piece on the Jerusalem plague has more detail on the spy ring and the ultimate fate of Aaronsohn and his wife.

So when I picked up The Perfectionists by Simon Winchester, it was partly because I have come to enjoy the history of the exceptional industrialists who have built the modern Western lifestyle, and partly to understand my husband (and, it increasingly seems likely, my son) a little better.

It’s a great book.

One of the reasons I really liked The Perfectionists is the clever subheadings for each chapter. The book covers tolerances from 0.1 to 0.0001 to 0.000 000 000 000 000 000 000 000 000 000 000 01 — the “near-atomic” level.

Probably the most memorable part for me was the section comparing Henry Ford (of Ford Motors, who is in large part responsible for the concept of a factory) and Henry Royce (of Rolls-Royce luxury cars, which for many years exemplified the concept of perfectionist engineering). But I suppose I should tell the story in order…

Chapter 1: Stars, Seconds, Cylinders, and Steam

The “father1 of true precision” (as opposed to fun contraptions like the Antikythera mechanism, or the big clocks that monastery2 timekeepers used) was an eighteenth-century Englishman named John Wilkinson, and he is a true “stranger than fiction” delight. A person in a novel who was so obsessed with iron as to make an iron boat, work at an iron desk, build an iron pulpit, and order that he be buried in an iron coffin would be considered to be absolutely, completely, ridiculously over the top for an example of “afraid of fairies” — but this guy really did all that (and more!) and wasn’t even afraid of fairies! He’s the one who pioneered the cast iron and boring machines vital to the steam engine, which I won’t go into much here because if you’ve managed to get to a point in your life where you’re reading this newsletter and don’t understand the significance of the steam engine, you’re just going to skim anything I have to say on the subject too.

Suffice it to say that Wilkinson built the first machine tool; machines capable of doing the precise boring work necessary for steam engines and cannon barrels to be a very specific size. These were massive, waterwheel‑driven machines built to handle heavy iron guns and cylinders, but even so — more capable of precision work than human hands.

The next guy who caught my attention was John Harrison, who invented the sea watch. He’s another guy who was around far enough back for the community to have a consensus built up around him; the consensus is that he got screwed by his government (although King George eventually came through and got him (most of) his money, Parliament and politics interfered with him winning the prize he obviously deserved for finding a simple and practical method for the precise determination of a ship's longitude. Harrison was a generational talent in the precision engineering field; he spent like 30 years perfecting that damn watch, in a story that reminded me less of other precision engineers and more of Rony Swennen — the guy who figured out how to breed bananas.

Like most organisms, bananas have a specific fertility rhythm — but it’s subtle enough that nobody before had figured it out. Swennen’s careful, numeric tracking of banana plants over decades — he kept at it for almost fifty years — let him breed bananas with way more seeds than they used to have. Like “two hundred instead of two” more.

I can’t even manage to exercise every day; these truly exceptionally useful-to-society men are next-level obsessed with their projects. Although they aren’t obsessed in a vacuum; this book had a lot to say about inventions that were birthed into being largely due to war.

It’s hard to imagine how we’d have our modern marvels of cars, internet, and cheap grain if not for the efforts of the British Navy during the middle of the 18th century.

Harrison’s early sea clock trials were made on Royal Naval warships of the day, warships that carried cannon in large numbers. Those cannons were made by English ironmasters, of whom John Wilkinson was among the most prominent and, as it turned out, the most inventive, too.

Basically, this chapter traces the birth of modern mechanical precision to John Wilkinson’s boring mill for cannon and steam-engine cylinders, linking it to accurate timekeeping and astronomy. Better cylinders made Watt’s steam engines efficient and reliable, and how improved clocks and astronomical observation depended on the same quest for exact measurement. Precision emerges as the enabling technology behind both industrial power and the scientific mapping of the heavens and the Earth.

Chapter 2: Extremely Flat and Incredibly Close

The development and distribution of the first really good locks (built by a guy named Joseph Bramah) were funded in large part due to French refugees from the 1789 Revolution. Specifically, by shopkeepers and homeowners who wanted to keep the French refugees out of their houses and businesses.

But Henry Maudslay was the guy who figured out how to actually build them cheap enough to sell; specifically, he’s the incredibly skilled engineer who built several different machine tools capable of doing the delicate work of making locks with interchangeable parts. I’m not experienced enough in metalworking to really viscerally grasp why it’s such a big deal whether or not he created a lathe flexible enough to craft a metal screw, but I’ve built stuff before; screws are a big deal. A method of cutting metal screws, efficiently, precisely, and quickly enables… a lot.

Maudslay — a teenager not yet finished his seven-year apprenticeship when Bramah found him — isn’t mostly known for the screw though. The most important thing he did (after he quit working for Bramah when curtly denied a raise) was figure out how to mass-produce the “block and tackle” pulleys used for hoisting sail on a warship. He worked in tandem with a guy named Brunel, who had the patent on a nifty system for mass-producing them.

What I found interesting about the book is how Maudslay is presented as the key component, although Bramah and Brunel were the ones with the ideas and the original patents. Ideas get a lot of credit in the press, but the guy who actually makes it work with skilled hands are really given a lot of screen time by this book — the author dug up several little-known figures and gave them the spotlight. As someone generally more impressed with engineers and machinists and ditch-diggers than DaVinci style doodlers, I fought that delightful.

Brunel gave Maudslay the drawings, and it took Maudslay six years to bring the designs to fruition despite the full backing of the Royal Navy. I’ve worked on enough software projects to know that the idea is just the beginning; actually building the damn thing is full of blind alleys and “ah hell” moments and “well I guess now I need to invent a way to—”

For example, Maudslay realized that a machine tool can make an accurate machine only if the surface on which the tool is mounted is “perfectly flat, is perfectly plane, exactly level, its geometry entirely exact.” Seems obvious; actually pretty tricky in practice, requiring three different planes. Really, though the flat plane comes up again several times throughout the course of the book, it’s the bench micrometer that I think Maudslay should be best known for. They called his the Lord Chancellor, because “no one would dare argue with it.”

Maudslay’s Block Mills were, by the way, the first factory in the world to be run entirely by steam engines, which is to say it ushered in a new era in terms of the sheer scope of what could be accomplished with mechanization.

Anyway, in this chapter, Winchester moved from rough early machine tools to the world of lapped surfaces, micrometers, and ultra-flat reference planes. Anchored around figures such as Joseph Whitworth and Joseph Bramah, he explains how making surfaces perfectly flat and distances exactly repeatable allowed parts to be measured and machined to previously unimaginable tolerances. This stuff underpins all later advances in precision engineering.

Chapter 3: A Gun in Every Home, a Clock in Every Cabin

By fluke, I listened to this chapter on the way to Harpers Ferry with my son, which was pretty awesome because the armory (the site of which we visited that very day) features prominently, along with guns — and at five he thinks guns are pretty cool.

To elide some details a bit, Frenchman Honoré Blanc figured out how to make rifles with interchangeable parts in 1785. This is super important because when a soldier’s gun breaks, he wants it back in working order now, not three days from now after a skilled artisan grinds down new parts to fit the rifle — by hand — at a smithy or whatever. Blanc gave a demonstration of the usefulness of these interchangeable parts to a bunch of dignitaries (including Thomas Jefferson, who was in France at the time) with a musket lock that he disassembled into springs and bolts and stuff, shook up in a box with lots of different parts, and built a working musket lock from the mixed-up pieces.

If not for Jefferson, interchangeable gun parts as an idea might have waited another century or so for someone to come up with it, because the French Revolution screwed up Blanc’s workshop and left him without a patron. But Jefferson was really impressed by the demonstration, and immediately understood the value of being able to just grab a part out of a box to fix a gun, instead of custom-forge one.

The most memorable part of the story, though, involves the first guy that the author really criticizes; the first cracks in the “this story is about perfectionists” facade begin to show, and he spends a fair amount of the book’s screentime talking about an appalling fraud: Eli Whitney, whose face is on postage stamps because he invented the hugely useful cotton gin.

But he also leveraged his reputation to defraud the American government, faked a Blanc-esque demonstration of guns with interchangeable parts, and tricked the gullible John Adams and Thomas Jefferson (among others) into thinking he had the engineering skills necessary to mass manufacture guns on American soil.

The truth is Jefferson had been hoodwinked, as had everyone else present that day. For there had been no molds, no machines for making all the parts “so exactly equal.” Whitney’s new-made factory, powered by water, not yet by steam (even though engines were readily available), had neither the tools nor the capacity to make precision-engineered pieces. Realizing this, he had instead hired a clutch of artisans, craftsmen, and told them to make the flintlock components with their own files and saws and polishers, and make them one by one, by hand—and not necessarily all the same, either, for the way he had planned his show did not allow for anyone to inspect the locks themselves, only that they fitted into the stocks.

It took eight years for the government to figure out that it was all bullshit. 1809.

In 1811, Simeon North filed a patent for the breech-loaded single-shot gun — which is much easier to load than the musket. Critically, it’s the first American gun with interchangeable parts that were really made with machine tools. Down in Harpers Ferry, John Hall used tons of gauges to make sure that they were really interchangeable. Over in Springfield, Thomas Blanchard — the guy responsible for shoe sizes — figured out how to make exactly replicable wooden blanks for all sorts of things, including gun stocks.

I love Harpers Ferry with my whole soul, so I’m going to quote the wrap-up paragraph in its entirety:

The management of the Harpers Ferry Armory was eager to try out all these new contrivances—despite its remote location, the armory was more accepting of innovation, oddly, than was the busier, bigger, older armory at Springfield, where Blanchard worked, and at which Simeon North was a regular visitor. Harpers Ferry became almost certainly the first establishment in the United States, maybe the first in the world, to employ precisional techniques and mass production to create weapons for the country’s military. To do so, it employed an array of these new technologies and ideas. It used the products of Blanchard’s gunstock machine; it also used John Hall’s milling machine, his fixtures, and his drop-forges; and its locks were made by the process invented by Honoré Blanc and perfected by Simeon North. From iron smelted in Connecticut to finished guns smelling of linseed oil (for the ashwood stock) and machine oil (for the barrel and lock), these were the first truly mechanically produced production-line objects made anywhere—they were also American and, just as Lewis Mumford had predicted, they were guns. Also, they were machine-made in their entirety, “lock, stock, and barrel.”

But anyway, the precision necessary for interchangeable parts became the foundation for mass production and consumer goods.

Chapter 4: On the Verge of a More Perfect World

This chapter kicks off with Tennyson and centers around the Great Exhibition at the Crystal Palace where Queen Victoria makes a long-distance bullseye rifle shot at Wimbledon. Standard gauges, machine tools, and measurement systems spread globally, building an industrial culture.

Joseph Whitworth is the star of the chapter. He figured out a bunch of useful stuff I guess, including a small-bore accurate rifle used by the Confederacy during the Civil War (the Union, ironically, found it too expensive). He figured out useful armor plating and a new kind of steel that was really useful for making guns. But mostly what stuck with me was making screws and bolts and very basic fundamental units of manufacture interchangeable and standardized and also very, very precise — instead of merely “very.”

John Wilkinson kicked us off with a machine that could bore a hole to a tolerance of one-tenth of an inch. After Whitworth, metal pieces could be made and measured to a tolerance of one-millionth of an inch. He got rich doing all this stuff, and — also hearkening back to the kickoff — built an iron billiards table. As the book points out: “When anyone today bleats about the need for a ‘level playing field,’ it is worth remembering that Joseph Whitworth was in all probability the first engineer to give us one.”

I want to share this section with you not because it contains anything in particular worth learning, but because it’s a pretty good example of the sheer enthusiasm with which the author approaches his topic. The whole book is like this, and it’s not the sort of description I can capture myself. is the only person I know who writes with this hilarious sort of take-the-piss hyperbolic accuracy.

He was large and bearded and oyster-eyed, rather frightening-looking—he had a face “not unlike that of baboon,” according to Jane Carlyle, the wife of Scottish social commentator Thomas Carlyle—and, besides his fearsome looks, was also known for his irascibility, his unwillingness to suffer fools gladly, his domineering manner, and (on a personal level) his relentless infidelity. But the twenty-three instruments and tools he had on show during those six months in London, though they may have lacked the luster and swash of big steam engines and thousand-spindle looms, provided a road map to what would become engineering’s future (and won their maker more medals than any other of the Crystal Palace exhibitors). Joseph Whitworth was an absolute champion of accuracy, an uncompromising devotee of precision, and the creator of a device, unprecedented at the time, that could truly measure to an unimaginable one-millionth of an inch. Before him there was precision; afterward, there was Whitworth-standard precision, and the Great Exhibition was where he made his reputation for it.

Chapter 5: The Irresistible Lure of the Highway

So as I mentioned in the beginning, Winchester juxtaposed Henry Ford’s Model T and Henry Royce’s Rolls‑Royce to examine precision in the motor age. The Model T embodies robust, “good enough” precision enabling cheap mass mobility, while Rolls‑Royce represents obsessive accuracy, quietness, and refinement at great cost. But even so, Ford and Royce are hilariously similar:

THE COMPANY THAT the world still knows by its hyphenated name, Rolls-Royce (though financial crises and corporate shenanigans of one kind or another have caused there to be all too many versions of the title) was famously founded in Manchester in May 1904. One year previously, in June 1903, and with much-less-remembered ceremony in Detroit, Michigan, the Ford Motor Company had been officially incorporated. Both companies were founded by dedicated, obsessive, oily-handed engineers, both men christened Henry, both born in modest circumstances and in the year 1863.

The chapter traces the parallels and distinctions between hand‑fitted luxury engines and automated, high‑volume car plants… and continues to trend of mildly to criticize some of the companies & brands he’s referencing.

Specifically, the way modern Rolls Royce just ain’t built like they used to be. Honestly, the most memorable part of this is the Rolls Royce road tests where the cars just go forever without any noise or manufacturing issues. But as far as “the history of car manufacturing” goes, the Founders Podcast episode about Ferrari was more compelling to me. All the old car companies have a lot in common, and not much about this chapter really surprised or interested me. Sorry.

Chapter 6: Precision and Peril, Six Miles High

Chapter six focused on jet engines and modern aviation—especially Frank Whittle’s pioneering gas turbines and the Rolls‑Royce Trent series. A bunch of my friends either love planes or actively work on building them, so I cared more here. Winchester describes the engineering of turbine blades, cooling systems, and control mechanisms operating at immense temperatures and stresses, and touches on the Qantas Flight 32 incident.

Tl;dr: microscopic imperfections can cascade into disaster, illustrating both the power and fragility of ultraprecise systems. Especially if a particular factory does a slipshod job of handling its maintenance and quality assurance.

The nice thing about this chapter is that it gives a pretty good explanation of how jet planes work… and it is much cooler than I realized. We coat steel in a microscopic layer of cold air to keep it from melting at “definitely higher than melting point of steel” temperatures! That’s incredible!

Here’s the full explanation, so I don’t bungle it by being an ignoramous:

There are scores of blades of various sizes in a modern jet engine, whirling this way and that and performing various tasks that help push the hundreds of tons of airplane up and through the sky. But the blades of the high-pressure turbines represent the singularly truest marvel of engineering achievement—and this is primarily because the blades themselves, rotating at incredible speeds and each one of them generating during its maximum operation as much power as a Formula One racing car, operate in a stream of gases that are far hotter than the melting point of the metal from which the blades were made. What stopped these blades from melting? What kept them from disintegrating, from destroying the engine and all who were kept aloft by its power? It seems at first blush so ludicrously counterintuitive: that a piece of normally hard metal can continue to work at a temperature in which the basic laws of physics demand that it become soft, melt, and turn to liquid. How to avoid such a thing is central to the successful operation of a modern jet engine.

For, very basically, it turns out to be possible to cool the blades by performing on them mechanical work of a quite astonishing degree of precision, work which allows them to survive their torture for as many hours as the plane is in the air and the engine is operating at full throttle. The mechanical work involves, on one level, the drilling of hundreds of tiny holes in each blade, and of making inside each blade a network of tiny cooling tunnels, all of them manufactured at a size and to such minuscule tolerances as were quite unthinkable only a few years ago.

The extra cool part of this is that the core way we do this hearkens back to technology the Greeks had:

There is a delicious irony here, however. For although, as one might expect, to make such a blade requires techniques displaying the very highest order of precision and computational power, they are combined with another means of manufacturing that is of the greatest antiquity. The “lost-wax method” was known to the Ancient Greeks, for whom precision was a wholly unfamiliar concept.* It is employed specifically in this case to allow the creation of the cooling tunnels within the blade; and the wax is melted out, as in Athenian days, just before the molten alloy is poured into the ceramic mold, which is now, absent the wax, busy with the network of voids for the eventual cooling air.

Definitely the coolest sciencey thing I learned about in this book.

Chapter 7: Through a Glass, Distinctly

Chapter seven chapter turns to optics: telescopes, cameras, and space observatories like the Hubble Space Telescope. There’s a not-quite-creepy anecdote about a guy who figured out Winchester’s address because of a magazine photo of his barn workspace, but for the most part Winchester explains how polishing mirrors and lenses to fantastically fine tolerances allows us to see distant galaxies or read tiny details in photographs, and how even slight errors—like Hubble’s initial spherical aberration, which I hadn’t known about at all—can cripple billion‑dollar instruments.

Chapter 8: Where Am I, and What Is the Time?

Chapter 8 was cool because I live near the Applied Physics Lab in Maryland. Several of my friends work there, actually. I had no idea that GPS was ~invented here. But, like the sea watch that allowed for safe navigation of ships, GPS is military technology funded by the Navy. The American Navy this time.

If not for the Cold War satellite system, I’d have gotten a lot more lost than I already managed in New York when I was up there for a wedding (the day before I wrote this line, and in fact most of this review was written in or on the way to NYC. The L/F transfer in Manhattan is brutal). Here’s why I can play my favorite mobile game: Pokémon Go:

The U.S. Navy, at the time, was looking for a foolproof, secure, and accurate means of locating its fleet of Polaris-armed nuclear submarines, and thus was born the Doppler satellite navigation system known as Transit. A prototype satellite was successfully put into orbit in 1960, and no more than six years after McClure’s memo (seven years after the launch of Sputnik), a flotilla of U.S. Navy Transit satellites was in orbit around Earth, and the first true satellite navigation system was declared to be fully operational.

For the rest of the chapter, Winchester explores navigation and timekeeping, from marine chronometers and sextants to atomic clocks. He shows how determining longitude at sea required unprecedented temporal precision, then follows the story through radio time signals, global time zones, and satellite‑based positioning. Our modern ability to know exactly where and when we are depends on layered systems of clocks and measurements whose hidden precision quietly structures commerce, warfare, and daily life.

Chapter 9: Squeezing Beyond Boundaries

Shifting to the microscopic and quantum realms, Winchester recounts the rise of transistors, integrated circuits, and nanotechnology, where features are etched at scales of nanometers and below. He brings in Heisenberg’s uncertainty principle as a conceptual limit, contrasting our drive for tighter tolerances with the fundamental fuzziness of matter. The chapter follows photolithography, clean rooms, and chip fabs, showing that modern computing and communication rest on engineering that pushes against physical and economic boundaries of precision.

My favorite part, though, was Shockley and Noyce — Fairchild Superconductors and the Traitorous Eight, aka the guys who founded Silicon Valley. This section stood out to me mostly because, once again, the Founders Podcast did this chunk of history a little better (Here’s the piece on Shockley, “creator of the electronic age” who was a jerk — and here’s the one on Noyce, who was really cool). For those who (like me) mostly hate podcasts, Esquire did a really great longform piece on “The Tinkerings of Robert Noyce”, which I read ages ago and adored.

Seriously, if you skipped this chapter and read that instead, you’d end up reading more but it’d be a lot more fun.

Except you’d miss the broader context of exactly what this level of precision means, for example:

The test masses on the LIGO devices in Washington State and Louisiana are so exact in their making that the light reflected by them can be measured to one ten-thousandth of the diameter of a proton. They can also compute with great precision the distance between this planet and our neighbor star Alpha Centauri A, which lies 4.3 light-years away.

The distance in miles of 4.3 light-years is 26 trillion miles, or, in full, 26,000,000,000,000 miles. It is now known with absolute certainty that the cylindrical masses on LIGO can help to measure that vast distance to within the width of a single human hair.

That’s crazy.

Chapter 10: On the Necessity for Equipoise

In this reflective chapter, Winchester asks whether endless pursuit of precision is unambiguously good, weighing its benefits against complexity, brittleness, and social cost.

He uses Tokyo watchmakers to demonstrate this point, and presents Japan as this weird but beautiful land that values precision and the trains running on time and clean streets and all the usual stuff Japanophiles like Craig Mod and Gwern adore… and also handmade perfect tea as opposed to perfectly perfect tea. Artisan craftsmanship isn’t dead, let’s not kill it — the book predates AI but it was an uncanny echo of the points I made in my article about how machines cannot replace the genuine human touch. A perfect circle is, in some ways, less beautiful than a beautiful unique coffee ring, or something.

The most interesting part of this chapter to me, though, was the story of how Japanese manufacturers managed to salvage an industry they’d tried to destroy, which rather reminded me of that time that Disney pulled its own hand-illustrators out of retirement to make a good animated film that they’d lost the tech for because it’s all computer generated slop now.

Except that—and this appears to be the decisive moment when a quintessentially Japanese devotion to craftsmanship was allowed to resurface—within a decade, the decision came down from the board to restart production. A halfhearted 1980s lipstick-on-a-pig attempt to make a quartz version of the Grand Seiko fizzled, whereupon the Hattoris realized, and did so without the dubious benefit of surveys and focus groups, that Japanese people had a lingering love affair with handmade mechanical watches, and would pay good money to support the kind of craftsmanship that would be necessary to make them again.

Maybe we’ll get good animated movies again soon. Disney seems to be working on it. For someone as fretful as me about “what if we lose industrial capacity because—” it was pretty reassuring, actually, that they managed to re-train and re-build the capacity to handmake artisan watches.

I love a book with a happy ending :)

My plan for 2026 is to write one of these link roundups every month. I’m also aiming to do a monthly longform review of a chonky nonfiction book, in the style of Empress of the East: How a European Slave Girl Became Queen of the Ottoman Empire by Leslie Peirce or my response to Tiny Experiments by Anne-Laure Le Cunff. With any luck, I’ll also manage a monthly deep dive on a nerdy topic, and a monthly post related to note-taking or productivity. That should give 2026 a bit more structure and regularity. I also want to expand my exercise habit to a for-real daily walk, read at least one chunky nonfiction book a month — and not necessarily the one I review, because I do have a backlog.

I’m going to start 1177 B.C.: The Year Civilization Collapsed by Eric H. Cline in dead tree form, and read The Scythian Empire by Christopher Beckworth as an ebook; we’ll see which one I finish first but I intend to discuss 1177 BC with folks in various places during January, because I will do a better job of digitizing my notes if I do it that way — please feel free to pick up a copy and follow along!

And that brings me to my final goal for 2026: by the end of 2026, I want to have a “bench” of at least 6 finished drafts in case I get sick or end up really busy, so that I don’t miss any weeks of posting. Things are going pretty well so far — I am pretty confident that next week my review of The Perfectionists by Simon Winchester should land in your inbox, because I wrote it on the train to New York last weekend. Keep an eye out for it if you or any of your friends are into nerdy deep dives on precision engineering, and in the meantime please enjoy this curated list of neat stuff I read but didn’t have a chance to tell you about until now.

Technology

• This article about how nobody knows how large software projects work seemed pretty in line with my experiences in software-related communities in the last twenty years or so. Institutional knowledge is important!

• I stumbled across this article rounding up “all the good news from 2025” and it’s not your usual fluff piece feel-good “man saves cat” list; this is a heartening roundup of diseases we have wiped out, ways in which human lives are objectively, materially better than they’ve ever been, etc. I don’t want to spoil it, but it’s just incredible how much got accomplished that didn’t fit some doomer narrative and so didn’t cross my feed before this.

• This is a really cool thing about how pen caps work.

• Here’s a deep-dive history from about how Bell Labs won its first Nobel Prize.

• Using data from Uber, this team was able to estimate the roughness of every road in America and precisely estimate the value people place on it, and so much more.

History

• I learned a lot about African history from this article, specifically early Nigeria and the impact of farming on local societies. I especially appreciated all the links to formal studies so I can dig more at my leisure, and it contrasts nicely with this paper about why the first European farmers vanished.

• One of the history questions I’m most intrigued by is “exactly how much did climate change impact life for people in ancient civilizations.” Modern political discourse and trendy perspectives in academia make it hard to get what feels like a straight answer, but I always try. Here’s a paper claiming that climate change is what allowed for Polynesian exploration, and another claiming that the Indus Valley civilization collapsed due to environmental changes.

• Here’s why there are such dense concentrations of cities in North Rhine-Westphalia compared to the rest of Germany.

• This comparison of Venice and Taiwan — both merchant states in a way I hadn’t really connected before — was fascinating.

• They found a huge undersea wall from 5800 BC off the coast of France!

• This “review” of Marie Antoinette by taught me a lot about how propaganda can really distort someone’s legacy; Antoinette was much cooler than most of us give her credit for.

• Speaking of neat powerful women, here’s a history of East African matriarchs from .

• This article from made me feel a lot better about thinking repainted classical statues are ugly. I knew some, but not all, of the backstory behind the “evidence based retouching” but this article has lots of contemporary art that isn’t ugly to help showcase what classical statues probably actually did look like when painted.

• Speaking of paint, here’s with a neat, deep divey breakdown of why so many control rooms were seafoam green.

• I had occasion to read Bret Devereaux’s breakdown of pre-industrial “spherical cow city” layout, and it was fascinating.

Science

• This is a deep dive on the history of titanium, which is very abundant but also doesn’t naturally occur much in its pure form… along with this other investigation of what it would take to make it cheap and abundant. I still kinda think aluminum is neater, but who knows how I would feel about it if I lived 200 years from now?

• Naked mole rats are cool. Here’s what they can teach us about living longer.

• Here’s a deep dive into the impact of trash can innovations on the raccoon population of Toronto. Spoilers: raccoons figured them out.

• Here’s why big animals like elephants are unintuitively important to healthy forests.

• Did you know there are planets upon which it rains glass?

Miscellaneous

• I’ve realized that one of my favorite genre of essay is “someone completely alien to my way of thinking, but kind of awful, writing an insightful piece that demonstrates a worldview I struggle to comprehend.” The latest I shared with some friends was about a guy who is, as far as I can tell, addicted to gambling on dumb Polymarket questions. Before that it was this guy who had sex with his brother’s wife as a teenager.

• I enjoyed Gwern’s discussion of perfume as an aesthetic, artistic experience, as well as this deep dive on what makes perfume smell sexy from , much more than I otherwise might have if I hadn’t already read books like The Tainted Cup (affiliate link, or my review), where the link between scent and memory is vital to the plot, or Paladin’s Grace, where the protagonist is a perfumer who hooks up with a Paladin whose god died.

• This look at how placeholder currencies can help charities operate more efficiently really helped me understand the value of even obviously “fake” “free market” monetary systems.

Media & Literature

I watched John Wick (and really enjoyed it, especially the way the Miss Perkins character and new dog at the end were handled) and Tropic Thunder (which had a mediocre script but excellent acting and costuming).

Now that I have kids, I try to listen to music that actually has something to do with my/our life instead of angry teenaged breakup songs, or at least stuff that puts me in a happy and loving mood. To that end, I also discovered two new songs that I adore: The Good Ones by Gabby Barrett and Tennesee Orange Megan Moroney.

That said, here’s some commentary about media and literature from other people:

• Here’s a delightful retelling of Gawain and the Green Knight stories from Arthurian legend, with lots of historical context from to make it accessible.

• This old movie review from starts off with “Christmas in Connecticut (1945) stars the greatest actress of all time, Barbara Stanwyck, as Elizabeth Lane, a tradwife influencer who’s faked the whole trad thing — and the wife thing, too. It’s the best movie about 2025” and continues being fascinating.

• The notes for the Wizard of Oz are really cool, especially the part where he framed the (stub of the) pencil he wrote it with.

• Weird Al Yankovic (and ) can teach us a lot about copyright law; this is a great article about the one time he probably went a bit too far with a not quite parody.

• This is a fun chart showcasing the most “life-changing” books. The data is derived from Amazon reviews.