Kienose Dissalwerg

Mathematician, algebraic topology, algebraic geometry, foundation of mathematics. He/him.

[Finn @aduno_tal]

A failed physicist, turn failed economist, turned blogger has thoughts on mathematics he doesn't understand.

[Arnaud Bertrand @RnaudBertrand]

We keep seeing videos of clashes between French highschoolers and the police but almost no-one speaks about why these highschoolers are in the street, as if it all happened in a vacuum.

They have several complaints: missing teachers (a huge issue, almost 10% of class hours aren't taught at all according to the French ministry of education - https://t.co/ucW9dFnebY - mostly due to missing teachers, it's insane, the equivalent of 2 whole days of class a month gone!), run-down buildings, classrooms above 40°C during summer, classes of 32-35 students, etc.

But, to me, the most salient complaint has to do with the new French system for getting into higher education, called "Parcoursup", which borders on the absurd and is a perfect illustration of France's Kafkaesque technocracy.

So, it used to be the case - when I was a highschooler in France myself - that getting to university or Grandes Écoles was relatively straightforward.

If you passed the bac - France's national end-of-high-school exam - you could enroll at your local uni. Dead simple.

And, if you wanted to go to a Grande École, you had to apply to a so-called "prépa" - a notoriously grueling two-year preparatory program - then sit the competitive exam. That wasn't simple at all but at least it was clear.

There was, admittedly, one issue with this system: since anyone with the bac could enroll into university, the most popular programs ended up with more applicants than seats, and had to resort to drawing lots.

In 2017, for instance, medicine in the Paris region received 8,507 first-choice applications for 7,650 places, and 857 applicants were left out by lottery (https://t.co/LfdCaFf6p7). A real problem, but a narrow one, affecting a limited number of programs.

In typical French technocratic fashion, the government's answer was to take a sledgehammer to crack a nut. They decided to tear down the entire system - which had largely been established under Napoleon - and rebuild it from scratch, for all 640,000 high schoolers who apply every year.

Now, you will undoubtedly be surprised to learn that, among other absurdities in the new system, highschoolers still pass the baccalauréat ("bac") but it's become almost entirely useless.

It's very hard to describe the new Parcoursup system without giving you a headache, because it is very complex. And that's a big part of the issue.

I'm still going to try though.

Here's how it works. In your final year of high school, you list up to 10 choices of program (e.g. "law at Panthéon-Sorbonne University") on the Parcoursup platform, and you're not allowed to rank them. This includes prépas for Grandes Écoles as well.

Every program then ranks every single applicant according to their own criteria, which are variable and may change every year.

First 5 absurdities:

1) As a student you're institutionally not allowed to have preferences when applying, your 1st choice counts just as much as your 10th choice. And you can't game the system by selecting only 1 choice, because it gains you nothing: programs can't see your other choices anyway. Choosing only one program just removes your safety net.

2) You're playing a game whose rules are only revealed once most of the moves have been played.

Say you really want to go into a specific program - again, let's take the example of law at Panthéon-Sorbonne University: this program will only tell you which criteria it uses to rank you, and how much each one weighs, in December of your final year of high school, shortly before you apply on Parcoursup.

And by then, most of what you'll be judged on (your grades from the previous year, your choice of subjects, etc.) is already set in stone, so all you can do is look at the previous years' criteria and pray they don't change.

3) The most absurd of all. As we saw above, Parcoursup was meant to end the "injustice" of popular programs having more applicants than seats, and of drawing lots as a result.

This exact problem has now been compounded by an order of magnitude: since everyone applies to 10 programs without ranking them, each of these programs gets absolutely flooded with applicants, most of whom will end up elsewhere.

For instance, in 2025, law at Panthéon-Sorbonne received 19,404 applications for 745 seats (https://t.co/RFMI6U58mt). In other words, ironically, the new system took a problem that was an exception - hitting a limited number of students - and made it the rule for all 640,000 who apply each year, all in the name of solving it. Completely Kafkaesque!

4) The new system is - obviously - also unpopular with university teachers, who have to do the ranking. I mean: imagine being a law teacher at Sorbonne and being told that your job now includes having to join a committee that has to review and rank some 19,404 application files every year. At 3-4 minutes per file reported by one university committee (https://t.co/QmxJVcbU95), that's 140-180 working days a year!

In practice, this means that committees rely on algorithms to pre-rank applicants and only look closely at some files. Which means students produce application files that nobody really reads: funnily, to prove this, a student last year replaced her cover letter with a brownie recipe and still got in (https://t.co/nBihkJXul0).

5) And, yes, it means the bac - an institution in France, put in place by Napoleon - is now almost completely useless given that, by the time bac results come out in July, you've already gone through Parcoursup. As a result, whether you have a good or bad grade doesn't change your fate one bit, as long as you pass.

Getting a 19/20 gets you exactly the same as an 11/20: Napoleon's bac has been reduced to a pass/fail formality.

But that's not all, we haven't yet spoken about the process after you apply and start getting responses from programs, which happens starting early June.

This one is a real beauty of majestic French bureaucratic complexity.

So programs can give you one of 3 answers: yes, no, or waiting list. Waiting list means not yet, but maybe later if another candidate gives up their seat.

As a student, you have 3 rules:
Rule 1. Once you get a yes, you have two days to accept it (reduced to one day if the answer comes in mid-August), or you lose it.
Rule 2. You can only hold one "yes" at a time
Rule 3. You can keep your waiting-list places while holding a yes. If a program you prefer later says yes, you can switch to it, and your previous "yes" seat is released automatically.

And, funnily enough, once you've received your first answers, you're suddenly obliged to rank the programs you're still waitlisted on, within a four-day window, a few days before the bac. Any you forget to rank get deleted.

Are you lost by now? If you are, you're not alone: in one survey, only 6% of French parents find it transparent, and only 5% fair (https://t.co/uZucbJCKUS).

Quite an achievement for a system whose literal objective was to make access to higher education fairer and more transparent.

And it's not as if the problem hadn't been solved elsewhere, in ways France could have learned from.

For instance in China, once you have your Gaokao score - China's national university entrance exam, roughly equivalent to the French bac - you list your choices for university in order of preference and places are then filled in one go, best scores first: each student lands in the highest-ranked choice their score allows. Done. Procedurally fair - even brutally so - simple and transparent.

But no, we French had to somehow decide that - bizarrely - the bac wasn't going to count anymore but previous grades would, that students wouldn't be allowed to rank their choices (until, suddenly, they're forced to in June), that each program would invent its own criteria and only reveal them once most of your grades are set in stone, and that the whole thing would play out not in one go but over weeks of waiting lists and 48-hour deadlines. All ending in a system that piles an immense amount of work, complexity, anxiety and stress on everyone involved.

And it culminates with protests against the administrative Kafkaesqueness of it all, and tear gas for the kids complaining about it.

How very, very French.

[doomslide @doomslide]

Check out this loser!

>uploads a draft to Chat on Sept. 8th
>gets scooped by Chat on Oct. 6th

"The result released by OpenAI (#311) on October 6, 2026... identical to a preliminary version of the present paper that was uploaded to ChatGPT on September 8, 2026"

LMAO get rekt

[Mayank Jha @mayankjha1089]

The actual excitement in math is and will always be doing math, not reading some 400 problem set slop I'm sorry.

[Kind and generous eunuch @fudanchee]

How twitter "leftists" look at you when you have crazy extremist opinions like "ethnostates are bad"

[ChessBase @ChessBase]

The dark side of the online world: Hanna Sayce's story #Chess #Schach #ChessNews https://t.co/j2y6FNakvb

[lll กกต หัวควย 🇹🇼🇭🇰🇺🇦🇲🇲 #ยกเลิกม.112 @Freiheit_NHLC]

ยอมรับใช่ป่ะว่ารัฐบาลมึงกระจอกขนาดนั้นจนต้องให้ฝ่ายค้านช่วยหรอ ไวบ์เดียวกับสลิ่มตามหาธนาธรช่วยน้ำท่วมเป๊ะเรยค่ะ 55555555

[Aubrey รักพ่อจ๋าที่สุด ☃️🖤🩷🤍✨️✨️ @WasAubrey]

เขาไม่ได้ห้ามเพราะพระเลือกกิน เขาห้ามเพราะมันอันตราย บางคนดูเห็ดไม่เป็นเก็บเห็ดมีพิษมาแกงให้พระกินก็ตุยยกวัดเด้อ อย่าหาทำ เขาห้ามก็ทำอย่างอื่นไปถวาย ไม่พอใจก็ไปวัดอื่น

[wise political commentator (derogatory) @b_n_d_l_e]

“math production will be democratized, indeed vibe math is already a thing” it was already democratized and how does having to pay a private company for the new tools make it more so?

[redhead ophelia 🇺🇦🏳️‍🌈 @redhead_ophelia]

WE SAVED THE OZONE LAYER. It hasn’t fucking been forgotten. We as a humanity just took action and saved it.

[Kienose Dissalwerg @KDissalwerg]

@alynokioku @DLovegoodzb @B_Rockin_98 You’re officially unc

[IMFR @imfr_imfr_imfr]

อ่านโควท การเมืองสำหรับนางแบกกลายเป็นเรื่องตลก/สนุกไปวันๆแล้ว จริงๆแล้วอาการนี้คือความสิ้นหวังอย่างแท้จริง

[Force To Live @ForceToLife]

คนโลกกว้าง vs คนโลกแคบด้านการศึกษา ชั้นเคยเจอคนขับแกร้บอายุ 19 ที่เอาเงินเก็บทั้งบ้านมาออกมอไซค์ ทำงานเช้า - 5 ทุ่ม ละตอนกลางคืนไปนั่งเรียนภาษาอังกฤษ มึงจะให้เขาตั้งใจเรียนยังไงไหว

[Delip Rao @ COLM26 @deliprao]

> Kevin Buzzard had a 5-year grant to formalize the proof of Fermat's Last Theorem, but now Claude has done it in 11 days

This is unhelpful framing that only enables grant agencies to justify their STEM funding cuts. These two outcomes are different — one is uplifting mathematicians’ understanding and the other is self-serving. See my previous tweet in the reply.

[ท๊าดา @TadaaVoila]

แอคนี้โว้กเรื่องความเหลื่อมล้ำรอบที่ n แต่เวลาว้อแตกก็เหยียดการศึกษาคนอื่นรอบที่ n เช่นกัน พ้อยครือ

[Tim Rice @TimRiceDC]

Francis Fukuyama, I’m sorry I ever doubted you.

[Meow’Dib loves The Odyssey @meowdib]

Shitting on Ed Witten (a Fields medalist and perhaps the greatest living physicist) while replying to one of the most verified crackpots in the world is the clearest indicator of being mental stunted

[iannnnn  @iannnnn]

เย้ เท่านี้เราก็ไม่ต่างจากเทียนอันเหมินที่บูลลี่ชาวเน็ตจีนมานานแล้ว

[Massimo @Rainmaker1973]

🦝: it's me it's me it's mee

[Yuan Yi Zhu @yuanyi_z]

Another proof of the Chinese as spiritually American hypothesis: