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idoubtit

3,429 karma · joined July 6, 2017

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idoubtit··on What do Visa and Mastercard do? An intro to card networks
> Visa transactions costs are 0,22 € out of a payment of 1 €, Mastercard's is 0,23 €, and the French CB network is 0,17 €.

Are you sure of these values? Because that's different from what I was told, which was that CB was cheaper for transactions of more than 10 €, because their fees were fixed, not rates like Visa and Mastercard.

From what I've just read (not counting the possible extra tax by the bank of the seller):

CB: 0.20% + 0.00117 € ⇒ 0.00317 € for 1 €, 0.20117 for 100 €

Visa: 0.20% + (0.01% to 0.014%) ⇒ up to 0.00214 € for 1 €, 0.214 € for 100 €

Mastercard: 0.20% + (0.15 to 0.17%)

The 0.20% is for the "interchange" described in the article. So it applies only when the seller and the buyer do not have the same bank. The maximal rate is fixed by the UE, and AFAIK everyone use the max value.

idoubtit··on PISA 2025 Students' reading and mathematics performance declined across the OECD
> The U.S. scores are interesting.

Unfortunately, those scores are not reliable. It is a recurring problem with the USA for the PISA studies.

The preliminary chapter explains why data has lower confidence is some places. For the USA, there were many problems, including political reluctance in some states or schools, that lead to uncontrolled biases. Notably, the ratio of unreachable children is 40 %, twice more than their upper limit for valid results.

idoubtit··on bzip3
Yes, bzip3 compresses that 1GB text file into 170 MB while zstd needs 213 MB (SI units, from my own tests with the "enwik9" file of the GP's page, and the latest releases of both programs, same commands). But the decompression (memory and speed) is a different story.

On my desktop, decompressing with zstd requires 128 MB and 1 s, while bzip3 uses 3.2 GB and 90 s.

Without `-b 511`, bzip3's ratio decreases and decompression requires about the same memory as zstd. But the decompression is still two orders of magnitude slower.

idoubtit··on Japan halves speed limit to 30km/h on all narrow city streets
Maybe in Japan it will be effective. Since their "zone 30" creation was apparently a success, it seems probable that people will generally comply. My experience in France differs.

I live in a French town where the default speed limit is 30 km/h instead of the national 50 km/h. In the street where I live, the drivers that willingly (sometimes they can't overtake bikes and slow cars) observe that limit are a tiny minority. Why would they, since there are no automated controls in the city, and police sets manual controls once in a blue moon.

My street was already at 30 km/h in 2016 when the global speed limit was introduced by the city council. I'm pretty sure the mean speed has increased since then, though I don't have hard facts to prove it[^1]. At first I thought that, since all road signs were removed except on the city borders, the drivers needed a constant reminder of a limit that they'd prefer to ignore. Now I just think that people soon saw that there was almost no risk in breaking the law.

[^1]: There was a study, but the methodology was so poor that it was inconclusive. They monitored the speed in a dozen streets before and after the change, but it was done for different lengths of time (one or two weeks), at different times of the year, and with explicitly no attention payed to potential popular events or roadworks. So the average speed was globally lower after the change, but in most streets it had increased!

idoubtit··on A Note from LWN
Do you realise that almost no one can understand what you're alluding to? So the comment looks not only vindicative but also stupid.

Just a reminder that may be relevant to your gripe: allowing free speech is perfectly compatible with forbidding abuse and hate speech.

idoubtit··on European Commission Revives Push for Encryption Backdoors in ProtectEU Strategy
The average American voter does think the USA play a positive role for the world, while the average non-American think otherwise. In details, a 2026 study from the Pew Research Center states that:

- 57% of A. think the USA contribute to peace in the world a great or a fair amount.

- Republicans and supporter think so at 82%.

- Outside of the USA, the median is at 35%.

idoubtit··on How would you know whether an ancient culture had zero?
No, that implication is not automatic. The Babylonian numeral system evolved over milenaries, and the simple space noting the absence of a digit between two digits was later noted by a "0" digit. But this symbol was never used by itself, so it did not mean "nothingness". In the same way, a civilization having the concepts of addition and subtraction does not automatically induce the concept of negative numbers.

On the other side, ancient Egyptian numerals did have a zero, but it was only for nothingness. But they did not have a placeholder zero, because their systems was similar to Greek and Roman numerals.

idoubtit··on How would you know whether an ancient culture had zero?
The question is the title is left unanswered by this shallow article. At least it's not AI slop since there are spelling mistakes ("You’re best hope").

> Say you’ve found 17 numeric symbols. You might infer that the writing used a base 20 system

Reals numerical systems are much more diverse than that. For instance, Babylon used a base 60 (hence our minutes and hours). But there were much less than 60 numeric symbols, since they had a symbol for 1 and 10. So 2 symbols for a base 60!

> never appears at the beginning of a number, you might infer that is a zero

In the later times Babylonians had a kind of zero, but it was very limited, only used to point the lack of a number between two, i.e. "2∅1" but never "21∅∅" which was written "21" (so numbers were ambiguous if the context didn't give the magnitude).

And Babylonians had floating numbers. So "4" could also mean 4/60.

What I mean is that Babylon had a zero, but it only covered a part of the positional modern zero. They could not write 0 - 3. And if their zero had been fully positional, there would have been numbers beginning with it, i.e. sexagecimals floats.

idoubtit··on Aphantasia Beginner's Guide
Same here. I immediately visualized one of my juggling balls (the hard kind, pastel blue) on my kitchen table, so the scene was clear. But I was focused on the ball, so I only felt someone approaching and saw their hand pushing the ball, which rolled and fell.

I tried to visualise a scene with more unfamiliar objects (a box in the street then a flood wave arrives) and I also built the scene from my own memories. But I'm obviously biased after the first test.

With objects that I've never seen myself (e.g. a handgun), I have a hard time imagining them and placing them in my imaginary scenes.

idoubtit··on Fuzzing the Gleam Compiler
I'm sorry, but I can't understand how AFL++ could be applied to the Gleam case.

The main presentation of the tool lacks any description of its coverage, but from deep inside the documentation[^1] I gather that AFL++ is only relevant for GCC/LLVM languages. Gleam is not one of those.

[^1]: https://github.com/AFLplusplus/AFLplusplus/blob/stable/docs/...

idoubtit··on More than half of adults in U.S. say they lack basic statistical understanding
The fact that 62% of Americans have little or no understanding of statistics may be related to those 40% of Americans that believe in Creationism, i.e. human (and fossils) were created by God a few thousands of years ago, and not of randomness and evolution over millions of years. I think no other industrial country has that disbelief in science. https://news.gallup.com/poll/261680/americans-believe-creati...

This problem with science is apparent in another survey: in 2009, a Pew Center publication showed that 33% of scientists in the USA believed in God (and 18% in a transient power), which is much lower than the 80% belief of the general American population at the time. Of course, this is not a proof of causality in either direction, but scientific knowledge is seemingly inversely correlated to religiosity. And the USA are still more religious than any other industrial more-or-less-democratic country.

idoubtit··on France's tax agency got hacked (in French)
I'm surprised. The stolen data had two parts: some relevant to the income taxes paid, some detailing the real estate (houses and lands) owned by the household. Are both of them public in Norway?

Anyway, the main problem is that the breaches into the many French national data stores seem increasingly frequent.

idoubtit··on France's tax agency got hacked (in French)
The post is verbose, but lacks substance:

- The last two sections (≈20% of the article, 5.Cloud and 6.IA) are barely relevant.

- Some comparisons are questionable. It claims that, since some taxes data was compromised, the trust in the national Federated Identity is eroded "as if Facebook Connect was hacked". That's strange, I think it should be "as the trust in Facebook Connect would be eroded when Facebook is hacked". Anyway, I think most people won't care.

- Some sentences make no sense: "Le piratage de Ficoba semble en être l'exemple type"... But "Ficoba" is not mentioned anywhere, and, though I know what the word means, I can't guess what the sentence points to.

The OP should have mentioned another important hack of French national structures that happened in december 2025 and which is well documented. IIRC, through phishing, a keylogger was installed on a teacher's computer. Then the hackers got credentials to an internal training platform for teachers. Then they exploited multiple security breaches and connections between Ministries to get access to the national police files.

idoubtit··on PostgreSQL for Everything
Why write a fanboy text with unfair comparisons that hide the Postgres limitations?

For instance, for many simple needs MySQL is simpler than Postgres, with similar performance and consistency.

* No need for a connection pool, while many use cases with Postgres require PgBouncer and Co.

* Easy sort (and basic search) of multilingual text, because MySQL has case insensitive UTF8 collations.

* No need to VACUUM, which can be a hard problem (it was, the last time I used Postgres).

For full text search, I once worked on a project that considered several alternatives for this, including Postgres. Manticore Search was finally chosen because it was more performant, with better search results.

idoubtit··on Show HN: Laptop is the last place your secrets are still in plaintext
* Dealing with encrypted files is easy, and more versatile than a generic wrapper. E.g. to load a secret environment: `eval $(age -d -i secrets.env.age)`. With the added bonus that it only relies on a trusted tool, age.
idoubtit··on A shell exclamation mark is not for yelling. Be lazy
Decades ago, I was taught to use `!` and Co, by a Linux user who was fond of the `sudo !!` trick. Then I switched from this implicit interpolation to explicit shortcuts, and I'm glad I did.

As suggested in the FAQ at the bottom, instead of !… you can use ctrl-r. Or better, optionally type the first letters then alt-p or "up". It's more powerful and more extensible. Other shortcuts, like alt-., allow navigating into the past parameters.

With up, alt-p, alt-. and such, the command line displays the real command. The !… magic is more error-prone and ambiguous; with zsh, I'd suggest hitting TAB to expand the magic into a static text.

I would add other entries to the FAQ: When I enter `sudo !!` will it be stored unchanged in the shell history, or stored after interpolation of `!!`? When I start a command line with a space, so that zsh does not put it in the shell history, will !… also ignore that line? Is `!$` recursive?

idoubtit··on We replaced Redis with MySQL for inventory reservations and it scaled
> not the best design [...]

So those engineers at Shopify worked hard for months on a more performant system, but they missed the obvious structure? They chose a complex denormalization for no good reason?

It may be true, but I think it's presumptuous to belittle their work when we have only partial information. My guess is that they had good reasons to think that the more obvious ways would not scale.

And from reading your comments in this thread, I believe your structure would fail at their scale. A SQL query that uses 2 sub-queries with "group by" is probably too heavy. From the post, at peaks there would be millions of active shopping carts.

BTW, I suspect most orders are just for 1 or 2 of each item, so the denormalization is not as heavy as it seems.

idoubtit··on Wikimedia Foundation refuses union recognition, hires union-busting law firm
> Almost half of their expenses still go into "keeping Wikipedia up" (+ it's companion projects)

That's a bit of a stretch. I couldn't find any up to date information, but for 2024-2025 WMF wrote: "Across the Product & Tech department, we plan on allocating an estimated 50% of our resources to Wiki Experiences, 30% to Signals and Services, 5% to Future Audiences, and the remaining 15% to Product and Engineering Services."[0]

So "keeping Wikipedia up" is a very minor part (15%) of the "Investments in Technology" budget. It receives around 7% (15% of 48%) of the WMF total budget.

That not to say the rest of those "Investments in Technology" is useless. It's just that it's mostly about developing features, like updating the Wikipedia app, or creating functions and Wikipedia Abstract.

[0]: https://meta.wikimedia.org/wiki/Wikimedia_Foundation_Annual_...

idoubtit··on How to Exist
> task-oriented jobs, like milking the cows, [...] or harvest the fields, [...] humans are more evolved to this kind of work given our 200'000 years of task-based genetics

The agricultural examples are not representative of the human past that forged our genetic structure.

Hominins are about 5 millions years old. Humans, 2m years. Modern humans, 300k years. Agriculture appeared around 10k years ago in the Middle-East, later in other parts of the world. So most of the human past is about hunting and gathering.

Apart from this detail, I wonder if there are well established scientific argument that make that "genetics of behavior" the main factor in our modern behavior. At first glance it looks like a wild theory, created by a journalist who wrote self-help books and held a psychology column.

idoubtit··on KOReader
> - I literally endure calibre because that's how I feed koreader. Any alternatives?

I use USB mass storage.

In details, I configured KOReader not to start mass storage automatically, so I need two taps after connecting the USB. Then on my Linux PC, I mount the device, exec a `rsync` command, then umount.

My ebooks directory uses Git (with LFS) so I can update it from several computers. I considered switching to git-annex, instead of gitlfs+rsync, but I'm not motivated enough to change a system that works.

> - Is there really no practical way to mark a book as read other than give it a star rating or a custom tag?

There are 3 states : reading, on hold, finished. The rating is optional. A long press on a book title will give access to this states and more.

All that metadata is stored in lua data files (a bit similar to JSON). With mass storage, it's easy to read or update these files. I use "on hold" to mean "dropped" (and I hide them in the listings).

idoubtit··on How the FSF sysadmins block botnets with reaction
That's interesting. I haven't used fail2ban for a long time, but reaction is worth evaluating. Unfortunately, that post does not describe their full configuration. Maybe it's on purpose, so that attackers can't adjust to fit.

My experience is that modern web scraping had no obvious pattern, since it is proxied through many IPs. The last time a server was failing to handle the pressure, we decided to temporarily ban IPs from some Asian regions. How does the FSF decide to ban an IP?

Why do they use iptables + ipset instead of nftables? Is there a technical reason or is it just legacy? AFAIK, Nftables is more performant, and IMO simpler. And it has native sets, see https://wiki.nftables.org/wiki-nftables/index.php/Sets

idoubtit··on How the terrorist group Boko Haram uses frontier AI
After a cursory read of the PDF, my impression is that the methodology is sound, but the results are blown out of proportion. Of course, if the title was "Boko Haram's internal hearsay about their use of AI", it would draw much less attention.

The weak part is that the interview were with only 15 persons that had knowledge about AI. But, from what I understand, but they never used it themselves. Only the top commanders and the specialized units could send prompts. So it's hard to guess what is the real AI use from a few indirect statements. For example, the commanders could have decided to spread the rumor they were using AI a lot, even if they mostly used plain web search, because they thought it would boost the morale.

For instance, why would anyone pay an AI service to get basic help like that:

> AI provided both immediate technical fixes by teaching “how to uncouple the gun by washing it with diesel” and tactical guidance, in terms of “how to change the military formation so that fighters with jammed guns move to the back and others take their positions until the problem is solved.”

BTW, the paper does explain that Boko Haram was initially just a plain sect, rather living peacefully. Then "following a violent government crackdown and Yusuf’s death in police custody in 2009, the movement turned into a jihadist insurgency". And the last time I read a report by Amnesty International about the conflict, it estimated that 55 % of civilian casualties were caused by the terrorist group, and 45 % by the security forces. The Nigerian army sometimes razed whole villages. Like always, the world is not black and white, good guys and bad guys.

idoubtit··on How the terrorist group Boko Haram uses frontier AI
If you opened the OP link, you missed the section "Featured in The New York Times".
idoubtit··on Road to Elm 1.0
> your definition of dead is elms definition of stability

If Elm's definition of stability is keeping bugs and runtime errors for years, then I'm glad I stopped using Elm long ago.

Not only were the issues unaddressed, but for the past years the PR got no human response. For instance this one¹ fixes infinite loops in the core. [¹]: https://github.com/elm/core/pull/1137

idoubtit··on Organic Maps
I also use OsmAnd~ for hiking, and even more for cycling. I tried CoMaps after a friend recommended it. In my experience, OsmAnd is much more powerful, and if you can tolerate its complexity and battery-drain, it's worth it.

- CoMaps is much simpler, but lacks features. OsmAnd has (too many) features and requires heavy configuration, e.g. to disable some features I never use and optimize battery life.

- Loading a track (GPX) in CoMaps is cumbersome (you have to "Open with..." from a file navigator). OsmAnd can load tracks from within the app, and just display them or turn one into a route. With CoMaps, I couldn't load more than one on a map. My GPX routes are prepared with BRouter on my desktop computer, since both apps are unable to build routes of 150 kms

- CoMaps is better at energy saving. OsmAnd drains my battery in 5-6 hours when the screen is on (the screen roughly accounts for half of the drain). YMMV. For long rides, I switch the phone off as soon as I don't absolutely require its help for navigation.

- OsmAnd has features that I would never give up. Notably, displaying markers on "drinking water" POI, so that I know when I'll be able to refill, or decide if I must deviate my route toward a drinking tap.

- There are more maps and data in OsmAnd than in CoMaps, and more visualisation options.

- Last time I tried CoMaps (from F-Droid), at some point the screen went blinking, alternating between home and CoMaps. The only way out was to shutdown the phone.

[edit: BRouter for routing]

idoubtit··on Podman v6.0.0
podman can work with kube files, which is the YAML format from Kubernetes. That's more "platform agnostic" than docker-compose. And it can be read as a documentation in the same way.
idoubtit··on The disappearance of Japan's animators
Of course quality is subjective, but my own stats on AniDB show no decline.

I've watch at least one anime produced every year from 1977 to now. For 2000-2025 I've watched 24 to 62 anime of each year. My average vote by year is surprisingly stable at 5 ±0.6.

My top votes also don't show any significative tendency. Out of my 25 favorite anime, 6 were produced in 2020 or later. Notably the film "Kaguya-hime no monogatari", but also seinen series like "Nami yo Kiite Kure", "ACCA" or "Eizouken".

BTW, "Eizouken" (2020) is wonderful, and it's about a young girl wishing to become an animator, and how she creates short animes with her friends. I strongly recommend it!

idoubtit··on Mistral OCR 4
My father once received a letter from Algeria, with 3 words on the envelope : his first name, "Créteil" (the town where he lived, ≈100k inhabitants), and "France". Of course, in the 70s there was no Internet nor central database to find him, yet the postal service managed to deliver the letter. He was a very active social worker, managed a youth football team, etc. which made him locally well-known by his first name.

Nowadays, many people can't find anyone or any place unless their phone helps them. And postmen never stop to chat. Such a letter would not pass through the technology process, and probably not through the human network.

idoubtit··on Can you see three trees?
I also think these are harmful simplifications, for several reasons.

First of all, I'm skeptical about the study that proves that people seeing three trees have better mental health. There are so many factors that it's hard to separate one. A solid study would compare families living in the same building, roughly at the same floor, and with similar parameters (family size, income, education, street noise, etc.). Comparisons from different buildings induce too many side factors. I think that collecting this sample would be very hard. I can't access the full-text behind the paywall, so I don't know their methodology, and their abstract is vague, so I fear the paper is meaningless.

Then do people really watch that much through their windows? I'd be surprised that having a glimpse of a few trees at home once a day could change anyone's life.

Even if trees did has a positive impact on mental health, I suppose inciting people to bike or walk (at least partly) to workplaces and stores would dwarf that impact, for mental and physical health.

Lastly, the 30% of tree cover seems arbitrary. For the same percentage, would covering every street with trees have the same impact as keeping trees inside parks? I think the goal to provide places where people go for a walk requires different solutions than the goal to reduce the heat in a concrete jungle.

idoubtit··on Let's Encrypt bans certificate usage in any US sanctioned territory [pdf]
There were reason to believe they were less subject to US juridiction: their Subscriber Agreement is for "Sectigo Limited, a limited company formed under the laws of England and Wales". See https://www.sectigo.com/uploads/backgrounds/Certificate-Subs...

Sadly, their United Terms and Conditions in section 8.2 are even more restrictive than LE's. They reject any entity "located in, incorporated under the laws of, or owned (meaning 50% or greater ownership interest) or otherwise, directly or indirectly, controlled by, or acting on behalf of, a person located in, residing in, or organized under the laws of any country sanctioned under the laws of the U.S. or E.U." See https://www.sectigo.com/uploads/backgrounds/United-Terms-and...

From a layman point of view, it could even mean that the ICC and the UN are prohibited from using Sectigo. The Customer must have no "affiliates, officers, directors, or employees" that are on sanction lists, and the US have sanctioned some high-profile members of the UN and the ICC that spoke about the genocide in Gaza.

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