jacobolus

The Antikythera mechanism is 4 centuries after Thales, during which time there was extensive additional study done by Greek astronomers. Evidence of old solar eclipse predictions seems pretty sparse; I can't figure out when the first successfully predicted solar eclipse was that we are certain about.

Sorry, typo: 585 BC

Thales' supposed prediction of a solar eclipse is not considered plausible by experts in the history of astronomy. At the time and for long afterward there was no sufficiently accurate data / theory to predict solar eclipses.

There are a wide range of speculations about what Herodotus might have meant by the relevant passage:

> [...] another combat took place in the sixth year, in the course of which, just as the battle was growing warm, day was on a sudden changed into night. This event had been foretold by Thales, the Milesian, who forewarned the Ionians of it, fixing for it the very year in which it actually took place. The Medes and Lydians, when they observed the change, ceased fighting, and were alike anxious to have terms of peace agreed on.

Herodotus doesn't give any additional details. Later people assumed he must have meant a solar eclipse and the one of the only ones that makes sense for the place is the one of 485 BC, but there are plenty of historical details that make that seem dubious. For example, that eclipse would have arrived around sunset, and one of the kings Herodotus mentioned apparently died about 10 years before that.

"Original Cast" is a record label that sells records of obscure musical theater shows.

Usa is a city in Japan, and according to the internet the "Made in USA" thing is a joke or myth.

As far as I can tell both of your speculative claims don't reflect any real thing that happened.

> overestimate how well they learn things without the feedback of formal education

People benefit greatly from external human feedback, but 1:1 tutoring (with a good tutor) is roughtly an order of magnitude more effective and efficient than a classroom, and classrooms themselves vary wildly; in general the more participatory the better.

Self learning without any help can be more effective and efficient than a typical classroom, because as it is self directed, self paced, can use the best materials someone can find and a whole variety of them vs. whatever was assigned, etc., but it takes a lot of skill (which comes from past practice) and effort on the part of the learner. Many researchers/scholars are doing significant amounts of self-directed learning as their career, and can get very good at it with decades of practice.

The speed of learning in a classroom with 15+ students is inevitably unbelievably slow, and the time is used incredibly inefficiently. This isn't any particular problem with specific teachers, but as far as I can tell an inherent problem with aligning a bunch of people's preparation, motivation, and attention, and a problem with giving feedback in a 1:many setting. Teaching/learning speed generally seems worse at a primary school level vs. at a college level, given a very good teacher in both; I'm not sure if this is because of better prepared (because older) students, or just more motivated students.

This will possibly help region-central cities keep a small proportion of the jobs that have moved to the biggest national/international cities. It's not going to help rural villages.

He made a previous video about washboarding: https://practical.engineering/blog/2026/6/2/why-roads-get-wa...

Larry Sanger's "life's work" is trying to destroy or undermine Wikipedia. He needs to give it up.

He was involved in the project for a very brief time. He immediately despised the volunteer community, couldn't handle the democratic governance model and discussions focused on evidence rather than credentials.

He left, and has spent the entire rest of his career starting a series of failed competitors and whining. Recently he has become a weird right wing conspiracy theorist, or at least pitched his public comments that way, I guess because nobody else cares anymore what he has to say.

The login gating on Twitter was relatively recent (within a year or two, IIRC) before Musk took over, and also relatively mild. Non-logged-in users could still read most tweets, conversations, lists, etc. It was annoying and user-hostile though.

When Musk's people took over they very briefly removed any login gate, then very soon after they completely blocked all meaningful non-logged-in access to the site. Which is frankly fine with me: it's a good reason to never visit a place that has become a cesspool of scams, porn, and white supremacist propaganda.

It's a cute little optimization puzzle they made for people to solve, with lawn mowing as a graphical hook to make the problem more approachable and fun. Similarly, my kids have a physical logic puzzle where the theme is putting plastic cats into plastic boxes, but it's not supposed to be training for actually optimizing cat packaging.

How is this any more or less valid a use of time vs. mini-golf?

(The "real" analogous problems are things like optimizing factories or delivery routes, and the way they are solved is by programming a computer to, but this is a toy version.)

You can have high information density and still not have words running into each-other. Taking all of the space out from around text and information graphics makes them less legible, even for experienced "power users".

I think the goal here is more an aesthetic of being for "serious traders only" rather than a UI optimized for speed and clarity. The UI designers probably have little choice but to match the preferences of the user group though, even when those preferences are empirically detrimental.

Yes, it's "number of prescriptions" (but not "number of people prescribed" or "number of doses"). One person could be prescribed an antibiotic (or multiple) several times a year.

I'm amazed that there are 1216 antibiotic prescriptions per 1000 people per year in West Virginia though (2.5x the rate of California or Colorado, which itself frankly seems pretty high). Are large parts of the South just awash with bacterial infections, are people being prescribed antibiotics for viral illnesses, or are they just taking antibiotics prophylactically?

The "hornworm" caterpillars leave amazing poops behind. They look like (not so) little green grenades.

Their moths are important pollinators of some nice native flowers.

Strunk and White promote all sorts of prescriptivist nonsense, taking arbitrary personal preferences and elevating them to sacred rules (including many which they themselves constantly violate because they don't accord with idiomatic English).

As you say, the current profoundly corrupt Supreme Court majority will make up whatever justification they need to get the outcome they want, case by case, and don't believe in the concept of precedent, even their own.

The only thing that can be done is "re-chartering" the court – immediate significant expansion/packing followed later by drastic structural reforms.

I think the worldwide disruption of the pandemic melted people's brains, and the recent surge in the anti-vax movement is a symptom. Along the lines of: if all this bad stuff happened and my life was significantly harmed, it must be someone's fault; all those doctors and scientists kept advising everyone on what they thought was happening and what to do, so they're probably the ones who caused the problem.

The owner of a book doesn't owe anything to a random future person who picks it up from their estate sale or whatever. Vanishingly few books are irreplaceable enough to need to be treated as special relics to carefully preserve for posterity, and those that are tend to be already in a museum, library, or the collection of someone fastidious.

> sucks to see someone else's notes

You don't have to buy books with notes in them.

The basic problem is that to get to the objects you mention here is at least 3 or 4 years of full-time study away from the kind of math people learn for a typical college degree in science or engineering. If you really want to understand them, to make your "digging" efficient you should probably just get a pure math degree, but setting aside several years to satisfy occasional curiosity is not feasible for most people for various reasons.

One unfortunate feature of published pure math research is that often the ideas are quite accessible and straightforward and don't really require special abstractions or terminology, but those get used anyway because for someone who already has a math PhD it saves a bit of effort.

The big problem I have with Axler's presentation of the SVD is that it's backwards. It leads with a bunch of completely dry and technical minutiae written formally, loads students up with tedious and confusing technical exercises they aren't likely to appreciate, and defers the motivation, context, explanation, and pictures until a few dozen pages later (probably multiple weeks later for a course), and in my opinion doesn't do a great job with them even then. I think this does a big disservice to students, and I wouldn't recommend anyone learn about the SVD this way. (Admittedly, the SVD is treated more like a curious aside than a centrally important tool in Axler's book; he's not trying to train people to use numerical methods.)

The best place to learn about the SVD is probably in the context of some kind of concrete problem (the most illuminating would be a problem in statistics, image processing, geometry modeling, or whatever, but it could also be a more abstract pure math problem, something about quadratic forms or something) that demonstrates an actual need for it, and then introduce the idea with an intuitive explanation supported by pictures and spatial reasoning. The actual technical details are not really that complicated or hard to figure out once you understand the concept, but if you don't understand the concept then trying to prove a bunch of obscure technical statements just seems like pointless busywork.

That's all well and good, but you also shouldn't excuse authors for not providing context, motivation, or explanation under the theory that the students should really be figuring out the whole subject from scratch for themselves.

If you are really lucky the result of not explaining things might be an occasional exceptional student who works out a correct personal concept. But more commonly the result is just an unfilled gap in understanding and either a moderately motivated student who develops fluency with symbol twiddling but doesn't get the point of what they're doing or a less-motivated student who decides the topic sucks and gives up.

I've read a lot of linear algebra books, and I personally find Axler's to have average quality exposition and a not tremendously insightful point of view. I know other people who swear by the book though, so YMMV. It's more appropriate for a well prepared pure math student who wants to go to grad school and has a goal of internalizing a lot of jargon so they can read/write pure math papers than for a scientist or computer programmer.

You can represent any arbitrary colors using RGB values for whatever "R", "G", and "B" primaries you like, they just might not fit in the range [0, 1].

(At least, under the strong assumptions we make in color modeling using the CIE system of colorimetry; the basic keyword is "Grassmann's laws".)

Really? I find the part about the SVD in Axler's book extremely unhelpful, big blobs of opaque formulas and jargon with next to no explanation or context that basically require either knowing the topic fully beforehand or a huge amount of effort to parse.

e.g. Axler's definition of singular values is the extremely dry and technical:

> Suppose T is in L(V, W). The singular values of T are the nonnegative square roots of the eigenvalues of T†T, listed in decreasing order, each included as any times as the dimension of the corresponding eigenspace of T†T.

(Using a dagger instead of an asterisk for the conjugate transpose since HN interprets and asterisk to mean italics.)

If you already just proved a lot of stuff about eigenvalues, this could be a serviceable definition; at any rate it saves space. But it doesn't really explain the point.

I'd recommend anyone interested in this or related topics read Trefethen & Bau (1997) Numerical Linear Algebra.

Housing has gotten much more expensive in many places, and jobs less stable.

Scott Perry didn't present any evidence for those claims. Ideologically he is opposed to the humanitarian work USAID does around the world, and he cheered as Elon Musk dismantled the agency.

Perry was also one of the key figures in the criminal conspiracy trying to overturn the result of the 2020 election and overthrow the US government to install Donald Trump as a dictator based on a series of outrageous lies. If Trump hadn't been elected again in 2024, interrupting the relevant investigations, there's a decent chance Perry would be either on trial or perhaps even already convicted for his crimes (conscious of his guilt, he directly asked Trump for a pardon).

I wouldn't consider any claims he makes credible without some corroborating evidence.

In practice what happens is that on average the tool-user's wages go up slightly but most of the jobs in the field are eliminated, and the resulting large profit mostly goes to managers and financiers.

Each congressperson's staff gathers all of the comments they get, counts them up, and reports back to the congressperson, passing along anything they think would be useful information; if you write a clear and careful letter about an obscure topic there's a decent chance the congressperson themself will see it. Congresspeople typically have local ties in their area and caring what their constituents think is their job.

It's a serious problem that there are some congresspeople who don't do any local events, send all comments straight to the trash, etc. You should vote those folks out.

In the longer term, we should push for significantly increasing the size of the US House of Representatives to 5–10x the current size and implement serious campaign finance reforms. In combination, these will help make congresspeople more responsive to constituents and less reliant on donors.

One is people's lived experience: "Hard-working families immigrate to a land of better opportunity and build a life for themselves, integrating as upstanding members of the community."

The other is nativist propaganda: "Hordes of scary 'aliens' are coming to take your jobs and destroy your way of life, bringing their drugs and crime and turning your neighborhood into a trash heap. They might even eat your pets!"

People have difficulty noticing that the second story is supposed to be a description of what they or their ancestors personally lived as the first story; people compartmentalize and sometimes believe the propaganda version even though it directly contradicts their lived experience.

Scholars aren't supported by sales of their published work, but by teaching/research salaries, much of the money for which comes from the public via government grants.

Musicians by and large aren't supported by record sales, especially in the streaming era, but by concert tickets, merch, etc., or often by other income sources like paid lessons, session work, one-off commissions for specific customers, etc.

Very few fiction authors make a living at it, and most of those who do are barely scraping by.

Journalism is in a very sorry state in the 2020s; its long-time essential income source – classified ads – collapsed a couple decades ago under pressure from free or cheap online substitutes and the industry still hasn't figured out a viable alternative at scale. There has been a 75% drop in local journalists since 2000, most important local news now goes unreported (in many places there is no local reporting whatsoever) and regional/national scale journalism has been increasingly co-opted by the super-wealthy and turned to propaganda. Independent industry leaders with integrity are, over time, replaced by shills and the ethics of industry culture is degenerating.

Big budget TV/movies is probably closest to matching your argument, since these require large-scale coordination by hundreds of people to produce, but here too there are significant complications.

In all of these industries, the people making most of the profit are businesspeople rather than creators, though a trivial number of celebrity creators make good money.

Much of the published culture you mention is done entirely as a hobby, and our current copyright regime actually stands in the way of creation as much as supports it.

One thing to keep in mind is that many (most?) of the books and papers in these archives are decades old, usually no longer in print, make zero or vanishingly small amounts of money for their original creators, are sometimes only physically available from distant libraries that are challenging to access, etc.

In doing scholarly research, it's extremely helpful to be able to quickly search and skim hundreds of vaguely relevant sources, but simply wouldn't be worth the trouble to pay for or track down a "legitimate" copy of every one, and in many cases would be physically impossible. These "pirate" archives make doing real library research, previously limited to scholars at top-tier universities, accessible to orders of magnitude more people.

There really isn't that much profit in most of these works, and whether a scholar reads one on their laptop screen vs. in a physical book in a university library somewhere doesn't have any material impact on the original authors, editor, illustrator, translator, printer, etc.

That sounds plausible. Most of the features are kind of gimmicky bolt-ons added piecemeal and not really integrated with each-other. They make for cool 10-second demos but then most users ignore them because they aren't part of a coherent system. The result is a menu after menu of gimmicks, like a cabinet of hyper-specialized kitchen tools bought from infomercials. There has been limited product vision about the core abstractions and their basic composability. If you give a skilled user a photoshop version from the early 2000s they'll largely be able to do what they need, because there hasn't really been much fundamental innovative improvement in the past ~25 years.