Was the first model to explain the Balmer series, notably linking atomic spectra to the Planck constant and therefore to other initial quantum mechanical observations.

This was one of the first major models that just said:

It still treats electrons as little points spinning around the nucleus, but it makes the non-classical postulate that only certain angular momentums (and therefore energies) are allowed.

Bibliography:

Since 2015 Ciro Santilli has carried out a campaign to promote freedom of speech in China.

Centerpiece: github.com/cirosantilli/china-dictatorship

Fully rendered at: github.com/china-dictatorship

The campaign has centered around publishing censored keywords on his Stack Overflow username, thus using his considerable Stack Overflow presence to sabotage the website in China. Here is an early web archive.

Like most people in the West, Ciro has always been for political freedom of speech, and therefore against the Chinese government's policies.

However, the seriousness of the matter only fully dawned on him in 2015 when, his mother-in-law, a then a 63-year-old lady, was put into jail for 15 days for doing Falun Gong.

And all of this was made 100 times worse because Ciro deeply loves several aspects of China, such as food, language, art and culture, and saw it all being destroyed by the Communists: cirosantilli.com/china-dictatorship/does-ciro-santilli-hate-china

The rationale of this is to force the Chinese government to either:

In the beginning, this generated some commotion, but activity reduced as novelty wore off, and as he collected the reply to all possible comments at: github.com/cirosantilli/china-dictatorship.

This campaign has led him to have an insane profile view/reputation ratio, since many people pause to look at his profile. He is point "A" at the top right corner of Figure 2. "Scatter plot of Stack Overflow user reputation vs profile views in March 2019 with Ciro Santilli marked as A":

Ciro feels that the view count started increasing more slowly since 2020 compared to his reputation, likely every single Chinese user has already viewed the profile.

Further analysis has been done at: stats.stackexchange.com/questions/376361/how-to-find-the-sample-points-that-have-statistically-meaningful-large-outlier-r

Ciro Santilli's Stack Overflow contributions have, unsurprisingly, centered around the subjects he has worked with: systems programming and web development, and necessary tooling to get those done, such as Git, Python, Bash and Ubuntu.

His best answers are listed at: Section "The best articles by Ciro Santilli".

Stack Overflow has been the initial centerpiece of Ciro Santilli's campaign for freedom of speech in China, until Ciro noticed that GitHub might be potentially even more effective for it.

In Stack Overflow Ciro likes to:

In practice it also happens that Ciro:

When he gets an upvote on one of his more obscure answers, Ciro often re-reads it, and often finds improvements to be made and makes them.

He doesn't like to refresh the homepage looking for easy reputation on widely known subjects. See also: online forums that lock threads after some time are evil.

The result is that Ciro ends up getting relatively a lot of reputation without much work! The term passive income, much beloved by fake investment gurus, comes to mind. But now it's "passive reputation"! And it is useless! Yay!

For this reason, Necromancer is Ciro's favorite badge (get 5 upvotes on a question older than 60 days), and as of July 2019, he became the #1 user with the most of this badge. Announcement on Twitter.

The number two at the time was VonC (see also: Section "Epic Stack Overflow users"), who had about 16 times more answers than Ciro in total! From this query: data.stackexchange.com/stackoverflow/query/1072396?&Date=2019-07-01&UserId=895245 it can be seen that as of July 2019, 1216 out of his 1329 answers were answered 60 days after the questions and constitute potential necromancers! Compare that to VonC's 1643 potential necromancers out of 21767 answers!

VonC eventually took back the lead in 2022, dude's a machine!!! twitter.com/cirosantilli/status/1546389532014247936

Someone at Ciro's work once said something along:and this does ring true in Stack Overflow as well. When you are answering stuff, it means that you either didn't know, or that the information wasn't well available, and so your specific application is progressing slowly because of that. Once the generic prerequisites are well solved and answered, you will spend much more time on your business specific things rather than anything else that can be factored out across projects, and so you will get more "directly useful work" done, and less Stack Overflow answers. Of course, without the prior research in place, you can't get the final product done either.

In terms of per year reputation ranks, Ciro was in the top 100 in of the 2018 ranking with 38,710 reputation gained in that year: stackexchange.com/leagues/1/year/stackoverflow/2018-01-01?sort=reputationchange&page=4 (archive). He reached top 50 in 2022. Note that daily reputation is mostly capped to 200 per day, leading to a maximum 73000 per year. It is possible to overcome this limit either with bounties or accepts, and Ciro finds it amazing that some people actually break the 73k limit by far with accepts, e.g. Gordon Linoff reached 135k in 2018 (archive)! However, this is something that Ciro will never do, because it implies answering thousands and thousands of useless semi duplicate questions as fast as possible to get the accept. Ciro's reputation comes purely from upvotes on important question, and is therefore sustainable without any extra effort once achieved. Interestingly, Ciro appeared on top of the quarter SE rankings around 2019-11: web.archive.org/web/20191112100606/https://stackexchange.com/leagues but it was just a bug ;-)

There is no joy like answering an old question, and watching your better answer go up little by little until it dominates all others.

Stack Overflow reputation is of course, in itself, meaningless. People who contribute to popular subjects like web development will always have infinitely more reputation than those that contribute to low level subjects.

What happens on the specialized topics though is that you end up getting to know all the 5 users who contribute 95% of the content pretty soon as you study those subjects.

Like everything that man does, the majority of Ciro's answers are more or less superficial subjects that many people know but few have the patience to explain well, or they are updates to important questions reflecting upstream developments. But as long as they save 15 minutes from someone's life, that's fine.

There is great beauty when you are involved in a programming problem, and you suddenly remember: wait, I answered something related a few years ago! And especially so when you can go back and improve your old answer with new insight. This has great value, because when you were more newbie, you would have typed different words into Google Search than you would now. So by updating posts from when you were a newbie, you are helping other newbies more, as they are more likely to be also searching for those keywords. It is also very nice to have some head start on the answer's upvote count and not have to bootstrap yet another answer from 0 upvotes and have to go through all the competition!

For example, Ciro's most upvoted answer as of July 2019 is stackoverflow.com/questions/18875674/whats-the-difference-between-dependencies-devdependencies-and-peerdependencies/22004559#22004559 was written when he spent his first week playing with NodeJS (he was having a look at Overleaf, later merged into Overleaf, for education), which he didn't touch again for several years, and still hasn't "mastered" as of 2019! This did teach a concrete life lesson to Ciro however: it is impossible to know what is the most useful thing you can do right now very precisely. The best bet is to follow your instincts and do as much awesome stuff as you can, and then, with some luck, some of those attempts will cover an use case.

Ciro tends to take most pride on his systems programming answers, which is a subject that truly relatively few people know about. He likes it when he goes insanely deep into a subject, way beyond what OP had in mind, exposing full root causes and broader causes, see e.g.:

Ciro also derives great joy from his "media related answers" (3D graphics, audio, video), which are immensely fun to write, and sometimes borderline art, see answers such as those under "OpenGL" and "Media" under the best articles by Ciro Articles or even simpler answers such as:

There is something of greater value in perfectly presented technical knowledge, that goes beyond than simply getting something done. The pleasure of understanding and mastering something, and perhaps of the explanation itself. Sometimes when answering, Ciro feels like a tailor, where ASCII is his cloth. See also: Section "The art of programming", Section "Physics and the illusion of life".

Ciro's deep understanding of Stack Overflow mechanisms and its shortcomings also helped shape his ideas for: OurBigBook.com. So it is a bit funny to think that after all time Ciro spent on the website, he actually wants to destroy it and replace it with something better. There can be no innovation without some damage. It also led to Ciro's creation of Stack Overflow Vote Fraud Script.

After answering so many questions, he ended up converging to a more or less consistent style, which he formalized at:Like any other style guide, this answer style guide, once fully incorporated and memorized, allows Ciro to write answers faster, without thinking about formatting issues.

Ciro also made a question title style guide: meta.stackexchange.com/questions/10647/how-do-i-write-a-good-title/311903#311903 but for some reason the Stack Overflow community prefers their semi-defined title meta-language to proper English. Go figure.

Ciro started contributing to Stack Overflow in 2012 when he was at École Polytechnique.

Like all things that end up shaping the course of one's life, Ciro started contributing without thinking too much about it.

His first answer was to the LaTeX question: Standalone diagrams with TikZ?, which reflects the fact that this happened while Ciro was reaching his Ciro Santilli's Open Source Enlightenment.

Ciro's first upvote was for his 2012 question: How to run a Python script portably without specifying its full path?

When he started contributing, Ciro was still a newbie. One early event he will never forget was when someone mentioned a "man page", and Ciro commented saying that there was a typo!

When Ciro reached 15 points and gained the ability to upvote, it felt like a major milestone, he even took a screenshot of the browser! 1k, 10k and 100k were also particularly exciting. When the 100k cup (archive) arrived in 2018, Ciro made a show-off Facebook post (archive). At some point though, your brain stops caring, and automatically filters out any upvotes you get except on the answers that you are really proud of and which don't yet have lots of upvotes. The last remaining useless gamed achievement that Ciro looked forward to was legendary (archive), and which he achieved on 2021-02-16.

From the start, Ciro's motivations for contributing to Stack Overflow have been a virtuous circle of:

It is also amazing when you start having a repertoire of answers, and as you are writing a new answer, you remember: "hey, the knowledge of that answer would be so welcome here", and so you link to the other answer as well at the perfect point. This somewhat achieves does what OurBigBook.com aims to do: for each small section of a tutorial, gather the best answers by multiple people.

Ciro feels that his Stack Overflow alter ego is kenorb.

Another one is Aaron Hall, who is also very high on the necromancer list, answers in Python which is a topic Ciro cares about, and states on his profile:so another necromancer.

Way to go.

Ciro also asks some questions on a ratio of about 1 question per 10 answers. But Ciro's questions tend to be about extremely niche that no one knows/cares about, and a high percentage of them ends up getting self answered either at asking time or after later research.

Some fun reactions to Ciro's Stack Overflow activity: