Ciro Santilli

Ciro Santilli (三西猴)

Software engineer. Passion for computers, natural sciences and education. Opinions are my own.

\[ %% physics package % Partial derivative. \newcommand{\curl}[1]{\nabla \times #1} \newcommand{\dv}[2]{\frac{\partial #1}{\partial #2}} \newcommand{\divergence}[1]{\nabla \cdot #1} % Vector Arrow. \newcommand{\va}[1]{\overrightarrow{#1}} %% Real analysis \newcommand{\RFour}[0]{\mathbb{R}^{4}} \newcommand{\RThree}[0]{\mathbb{R}^{3}} \newcommand{\RTwo}[0]{\mathbb{R}^{2}} \newcommand{\R}[0]{\mathbb{R}} \newcommand{\functionDomain}[3]{#1 : #2 \to #3} %% Electromagnetism % Magnetic field vector \newcommand{\B}[0]{\va{\mathbf{B}}} % Electric field vector \newcommand{\E}[0]{\va{\mathbf{E}}} % Electric current vector. \newcommand{\J}[0]{\va{\mathbf{J}}} \newcommand{\vacuumPermittivity}[0]{\varepsilon_0} \newcommand{\vacuumPermeability}[0]{\mu_0} \]

GitHub | Stack Overflow | LinkedIn | YouTube | Twitter | Zhihu 知乎 | Weibo 微博 | Other accounts

Source code of this website: https://github.com/cirosantilli/cirosantilli.github.io

ID photo of Ciro Santilli taken in 2013 Ciro_Santilli's_learn_teach_apply_logo.png

1. Ciro Santilli

Ciro Santilli is a male human born in Brazil in 1989 AD.

Quick facts:

  • Nationalities: Italian and Brazilian

  • Grew up in: Brazil

  • Relationship status 2017-: married

  • Chinese name: 三西猴, means "three western monkeys". Phonetic approximation to SANtilli CIRO. Semi-unintentionally reminds Chinese people of Sun Wukong (孙悟空). Given by my wife, then girlfriend, as a semi-joke, and he took it up because the best way to take a joke is to go with the joker.

  • Laptop: high end ThinkPad

  • Distro: latest Ubuntu release

  • Vim or Emacs: Vim. But for The Love, will someone please make an open source C++ IDE that actually just works?

  • Tabs or spaces: spaces

  • Mailing list or Git(Hub|Lab): Git(Hub|Lab), with passion

  • System or unit tests: system

  • Default programming languages: Python and C++. He’ll learn Rust and Haskell once he’s rich.

  • Favorite musical instruments to listen: Chinese Guqin and electric Jazz-fusion guitar

337px Xiyou
Figure 1. Sun Wukong (孙悟空) is a playful and obscenely powerful monkey. He protects a Buddhist monk, and likes eating fruit, just like Ciro. Oh, and Goku is based on him. His Japanese name is "Sun Wukong" for the love. His given name "Wukong" means literally "the one who mastered the void", which is fucking awesome. Source.

1.1. The most important projects done by Ciro Santilli

Ciro Santilli has sometimes wasted time with low impact projects such as those listed at Ciro Santilli’s minor projects instead of doing higher impact projects such as those mentioned at: Section 1.2, “The most important projects Ciro Santilli wants to do”.

But maybe "Everything you did brought you where you are now." applies, maybe it is during the "low impact activities" that one gets the inspiration and experience required for the "high impact ones".

1.1.1. Linux Kernel Module Cheat

https://github.com/cirosantilli/linux-kernel-module-cheat

This is the most important technical tutorial project that Ciro Santilli has done in his life so far as of 2019.

The scope is insane and unprecedented, and goes beyond Linux-kernel-land alone.

It ate up every system programming content he had previously written, including:

so that this repo would better be called "System Programming Cheat". But "Linux Kernel Module Cheat" sounds more hardcore ;-)

Other major things that could be added there as well in the future are:

1.1.2. Ciro Santilli’s Stack Overflow contributions

https://stackoverflow.com/users/895245

895245
Figure 2. Ciro Santilli’s amazing Stack Overflow profile

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 a Git, Python, Bash and Ubuntu.

His best answers are listed at: Section 1.3, “The best articles by Ciro Santilli”.

Stack Overflow has been the initial centerpiece of Ciro Santilli’s campaign for freedom of speech in China.

In Stack Overflow Ciro likes to:

  • answer important questions found through Google which he needs to solve an actual problem he has right now, and for which none of the existing answers satisfied him, and close duplicates.

  • monitor less known tags which very few people know a lot about, but in which he specializes

When he gets an upvote on one of his more obscure answers, he 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 rep on widely known subjects.

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, who had about 16 times more answers than Ciro in total! From this query: https://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!

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: https://stackexchange.com/leagues/1/year/stackoverflow/2018-01-01?sort=reputationchange&page=4 (archive). 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 find 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.

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

For example, Ciro’s most upvoted answer as of July 2019 is https://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 ShareLaTeX, 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. And his "media related answers" (3D graphics, audio, video), which are immensely fun to write, and are borderline visual art.

Ciro’s deep understanding of Stack Overflow mechanisms and its shortcomings also helped shape his ideas for: Write free books to get famous website. 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: https://meta.stackexchange.com/questions/18614/style-guide-for-questions-and-answers/326746#326746 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: https://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 open source Enlightenment.

Ciro’s first upvote was for his 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 gamed achieved that Ciro looks forward to is legendary (archive).

Ciro Santilli with his Stack Overflow 100k reputation cup
Figure 3. Ciro Santilli with his Stack Overflow 100k reputation cup

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

1.1.3. Ciro Santilli’s campaign for freedom of speech in China

https://github.com/cirosantilli/china-dictatorship

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

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.

Chrysanthemum Xi Jinping with black red liusi added by Ciro Santilli
Figure 4. Chrysanthemum Xi Jinping with 六四 spice added by Ciro Santilli

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.

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

  • leave things as they are, and let censored keywords appear on Stack Overflow (most likely scenario)

  • block Stack Overflow, and lose billions of dollars with worse IT technology

  • disable the Great Firewall

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: https://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 5, “Scatter plot of Stack Overflow user reputation vs profile views in March 2019 with Ciro Santilli marked as A”:

Scatter plot of Stack Overflow user reputation vs profile views in March 2019 with Ciro Santilli marked as A
Figure 5. Scatter plot of Stack Overflow user reputation vs profile views in March 2019 with Ciro Santilli marked as A

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

1.1.4. Ciro Santilli’s minor projects

These are some smaller projects that Ciro Santilli carried out. They are all either for fun, or misguided use of his time done by an younger self:

1.2. The most important projects Ciro Santilli wants to do

These are projects which Ciro seriously considering doing, and which he believe could have a considerable impact in the world, given a few months of work.

They are sorted in order of "most likely to get done first".

1.2.1. Write free books to get famous website

https://github.com/cirosantilli/write-free-science-books-to-get-famous-website

In this project, Ciro Santilli wants to explore if it is possible to create a sustainable website that will make people write university-level natural science books for free.

The initial incentive for those people is to make them famous and allow them to get more fulfilling jobs more easily, although Ciro also wants to add money transfer mechanisms to it later on.

The key intended technical innovation of the website is a PageRank-like algorithm that answers the key questions:

  • who knows the most about subject X

  • what is the best content for subject X

where any user can create any new subject X.

Ciro envisioned a Wikipedia-like page, where you can fork a version of any subject or header to improve it, suggest changes via a "GitHub-pull-request-like" mechanism, and create bug reports under any given header.

Then, while reading an article about a subject, say, "The Fundamental Theorem of Calculus", you would be able to click a button, and easily view the other best articles about that subject.

Many subjects have changed very little in the last hundred years, and so it is mind-blowing that people have to pay for books that teach them!

More than that however, if such project succeeds, it could fundamentally change the way university is organized, enormously improving its efficiency.

It could destroy the current educational system and replace it by one that lets people choose what they want to learn.

1.2.1.1. Write free books to get famous website motivation

Since Ciro Santilli was young, he has been bewildered by the natural sciences and mathematics due to his bad memory.

The beauty of those subjects has always felt like intense sunlight in a fresh morning to Ciro. Sometimes it gets covered by clouds and obscured by less important things, but it always comes back again and again, weaker or stronger with its warmth, guiding Ciro’s life path.

As a result, he has always suffered a lot at school: his grades were good, but he wasn’t really learning those beautiful things that he wanted to learn!

School, instead of helping him, was just wasting his time with superficial knowledge.

First, before university, school organization had only one goal: put you into the best universities, to make a poster out of you and get publicity, so that more parents will be willing to pay them money to put their kids into good university.

Then, after entering university, although things got way better because were are able to learn things that are borderline useful, teachers were still to a large extent researchers who didn’t want to, know how to and above all have enough time and institutional freedom to teach things properly and make you see their beauty.

The very fact that you had very little choice of what to learn so that a large group can get a "Diploma", makes it impossible for people to deeply learn what the really want.

This is especially true because Ciro was in Brazil, a third world country, where the opportunities are comparatively extremely limited to the first world.

And all of this is considering that he was very lucky to not be in a poor family, and was already in some of the best educational institutions locally available already, and had comparatively awesome teachers, without which he wouldn’t be where he is today if he hadn’t had such advantages in the first place.

But no matter how awesome one teacher is, no single person can overcome a system so large and broken, without technological innovation that is.

The key problem all along the way is the Society’s / Government’s belief that everyone has to learn the same things, and that grades in exams mean anything.

Ciro believes however, that exams are useless, and that there are only two meaningful metrics:

  • reputation points for doing useful work for society

  • how much money you make

Around 2012 however, he finally saw the light, and started his path to Open source software Enlightenment.

Firstly, he was introduced to LaTeX, and his mind was blown. "Ha, so I can write my own books, and so can anyone, for free?" he though. Why isn’t everyone doing that!

Then he found two websites that changed his life forever, and made be believe that there was an alternative: Stack Overflow and GitHub.

The brutal openness of it all. The raw high quality content. Ugliness and uselessness too no doubt. But definitely spark in a sea of darkness.

University was not needed anymore. He could learn whatever he wanted. A vision was born.

To make things worse, for a long time he was tired of seeing poor people begging on the streets every day and not doing anything about it. He thought:

He who teaches one thousand, saves one million.

which like everything else is likely derived subconsciously from something else, here Schindler’s list possibly adapted quote from the Talmud: "He who saves the life of one man saves the entire world.".

So, by the time he left University, instead of pursuing a PhD in theoretical Mathematics or Physics just for the beauty of it as he had once considered, he had new plans.

We needed a new educational system. One that would allow people to fulfill their potential and desires, and truly improve society as a result, both in rich and poor countries.

And he found out that programming and applied mathematics could also be fun, so he might as well have some fun while doing this! ;-)

So he started Booktree in 2014, worked on it for an year, noticed the idea was dumb, and then started building this new idea and the courage to do it.

Ciro wants to be the next Jimmy Wales.

1.2.2. Large cohesive game world for robotic-like artificial intelligence development

Prototype: https://github.com/cirosantilli/Urho3D-cheat YouTube demo: https://www.youtube.com/watch?v=j_fl4xoGTKU

Less good discrete prototype: https://github.com/cirosantilli/rl-game-2d-grid YouTube demo: https://www.youtube.com/watch?v=TQ5k2u25eI8

Prior art research: https://github.com/cirosantilli/awesome-reinforcement-learning-games

Basketball stage of Ciro Santilli's 2D continuous AI game
Figure 7. Basketball stage of Ciro Santilli’s 2D continuous AI game

The goal of this project is to reach artificial general intelligence.

A few initiatives have created reasonable sets of robotics-like games for the purposes of AI development, most notably: OpenAI and Google DeepMind.

However, all projects so far have only created sets of unrelated games, or worse: focused on closed games designed for humans!

What is really needed is to create a single cohesive game world, designed specifically for this purpose, and with a very large number of game mechanics.

Notably, by "game mechanic" is meant "a magic aspect of the game world, which cannot be explained by object’s location and inertia alone". For example:

  • when you press a button here, a door opens somewhere far away

  • when you touch certain types of objects, a chemical reaction may happen, but not other types of objects

Much in the spirit of http://www.gvgai.net/, we have to do the following loop:

  • create an initial game

  • find an AI that beats it well

  • study the AI, and add a new mechanic that breaks the AI, but does not break a human!

The question then becomes: do we have enough computational power to simulation a game worlds that is analogous enough to the real world, so that our AI algorithms will also apply to the real world?

To reduce computation requirements, it is better to focus on a 2D world at first. Such world with the right mechanics can break any AI, while still being faster to simulate than a 3D world.

The initial prototype uses the Urho3D open source game engine, and that is a reasonable project, but a raw SDL + Box2D + OpenGL solution from scratch would be faster to develop for this use case, since Urho3D has a lot of human-gaming features that are not needed, and because 2019 Urho3D lead developpers disagree with the China censored keyword attack.

1.2.3. Website front-end for a mathematical formal proof system

When Ciro Santilli first learnt the old Zermelo–Fraenkel set theory and the idea of Formal proofs, his mind was completely blown.

Finally, there it was: a proper and precise definition of Mathematics, including a definition of integers, reals and limits!

Theorems are strings, proofs are string manipulations, and axioms are the initial strings that you can use.

Once proved, press a button on your computer, and the proof is automatically verified. No messy complicated "group of savants" reading it for 4 years and looking for flaws!

There are a few formal proof systems with several theorems in their Git tracked standard library. The hottest ones are:

And here are some more interesting links:

However, it is unbelievable mind, that there isn’t one awesome and dominating website, that hosts all those proofs, possibly an on the browser editor, and which all mathematicians in the world use as the one golden reference of mathematics to rule them all!

Just imagine the impact.

Standard library maintainers don’t have to deal with the impossible question of what is "beautiful" or "useful" enough mathematics to deserve merged: users just push content to the online database, and star what they like!

Interested in a conjecture? No problem: just subscribe to its formal statement + all known equivalents, and get an email on your inbox when it gets proved!

Are you a garage mathematician and have managed to prove a hard theorem, but no will will read your proof? Fuck that, just publish it on the system and let it get auto verified. Overnight fame awaits.

Notation incompatibility hell? A thing of the past, just automatically convert to your preferred representation.

Such a system would be the perfect companion to Write free books to get famous website. Just like computer code offers the backbone of Linux Kernel Module Cheat Linux kernel tutorials, a formal proof system website would be the backbone of mathematics tutorials!

Furthermore, it would not be too hard to achieve this system!

All we would need would be something analogous to a package registry like Python’s PyPI or NodeJS' registry.

Then, each person can publish packages containing proofs.

Packages can rely on other packages that contain pre-requisites definition or theorem.

Packages are just regular git repos, with some metadata. One notable metadata would be a human readable description of the theorems the package provides.

The package registry would then in addition to most package registries have a CI server in it, that checks the correctness of all proofs, generates a web-page showing each theorem.

All proofs can be conditional: the package registry simply shows clearly what axiom set a theorem is based on.

Bibliography:

1.2.4. Molecular biology is the next big thing so do anything in that area

https://github.com/cirosantilli/awesome-whole-cell-simulation

As of 2019, the silicon industry is ending, and molecular biology technology is the most promising and growing field.

Such advances could one day lead to both biological super-AGI and immortality.

First, during the 2000’s, the cost of sequencing fell to about 1000 USD per genome in the end of the 2010’s: Figure 8, “Cost per genome vs Moore’s law from 2000 to 2019. Source.”. The medical consequences of this revolution are still trickling down the application ladder today, inevitably, but somewhat slowly due to tight control of medical records.

1024px Cost per Genome
Figure 8. Cost per genome vs Moore’s law from 2000 to 2019. Source.

Then, in the 2010’s, CRISPR/Cas9 gene editing started opening up the way to actually modifying the genome that we could now see.

What’s next?

DNA synthesis, see for example: https://twistbioscience.com/ | https://www.evonetix.com/technology/ | http://dnascript.co/ | https://www.ansabio.com/ | https://www.nuclera.com/

Other cool topic include: simulations of cell metabolism, protein and small molecule, microscopy (cristalography, cryo-EM), analytical chemistry (mass spectroscopy), single cell techniques (Single-cell RNA sequencing), …​

It’s weird, cells feel a lot like embedded systems: small, complex, hard to observe, and profound.

Ciro Santilli is sad that by the time he dies, humanity won’t have understood the brain, maybe not even a measly E. Coli…​

The only other fields that might become as big are:

but those have had enourmous investments for several decades without any fruits. Molecular biology is a much lower hanging fruit.

1.2.5. Videos of all key physics experiments

It is unbelievable that you can’t find easily on YouTube recreations of many of the key physics / chemistry experiments.

The videos must be completely reproducible, indicating the exact model of every experimental element used, and how the experiment is setup.

A bit like what Ciro Santilli does in his Stack Overflow contributions but with computers!

It is understandable that some experiments are just to complex and expensive to re-create, as an extreme example say, a precise description of the LHC, but up to the mid 20th century? We should have all of those nailed down.

We should strive to achieve the cheapest most reproducible setup possible.

Furthermore, it is also desirable to reproduce the original setups whenever possible in addition to having the most convenient modern setup.

Lists of good experiments to cover be found at: The most important physics experiments.

1.3. The best articles by Ciro Santilli

These are the articles ever authored by Ciro Santilli, most of them in the format of Stack Overflow answers.

Ciro posts updates on Twitter when new considerably cool ones are published: https://twitter.com/cirosantilli

1.4. How to contact Ciro Santilli

To contact Ciro Santilli publicly about any general subject that is not covered in a more specif repository, including saying hi or suggestions about his website, create a GitHub issue at: https://github.com/cirosantilli/cirosantilli.github.io/issues/new

For comments about China first read:

and then create a GitHub issue at: https://github.com/cirosantilli/china-dictatorship/issues/new

If you need private contact, extract his email from on of his GitHub repos or use LinkedIn.

Disqus comments were removed from his website in 2019-05-04, a manual dump is available here, removal rationale at: Why Ciro Santilli removed Disqus comments from his website in 2019-05-04.

1.5. Accounts controlled by Ciro Santilli

Ciro Santilli controls the following accounts.

With non-trivial activity:

Other accounts:

Accounts in Chinese websites. These accounts might be banned or altered or offer other limitations, so Ciro only communicates briefly through them:

Dead websites:

A younger unrelated Argentinian homonym that can be found through Google:

1.6. Ciro Santilli’s ideology

Welcome to the wonderful world of Cirism!

1.6.1. Unconditional basic income

Unconditional basic income is Ciro Santilli's ultimate non-transhumanist technological dream: to reach a state of technological advancement and distribution of resources so high that everyone gets money for doing nothing, enough for:

  • basic survival needs: food, housing, clothes, hygiene, etc.

  • two children to keep the world going. Or immortality tech, but is harder and borderline transhumanist :-)

  • high speed computer and Internet

Once a person has that, they can learn, teach and create whatever they want. Or play video games all day long if they wish.

Ciro santilli will not live to see this, and is content with helping it happen faster by increasing the efficiency of the world as. And having at least two well educated kids to carry on the project after he dies :-)

Technologies which would help a lot towards unconditional basic income, and might be strictly required required are:

Of course, it is all about costs. A human costs about 130k 2010 USD / year. So how cheap can we make the AGI / robot human equivalent / year for a given task?

AGI + humanoid robots likely implies AI takeover though. It would then come down to human loving bots vs human hating bots fighting it out. It will be both terrifying and fun to watch.

AGI alone would be very dangerous, in case it can get control of our nuclear arsenals through software zero days or social engineering. Although some claim that is unlikely.

Humanity’s best bet to achieve silicon AGI today is to work on: Large cohesive game world for robotic-like artificial intelligence development

1.6.2. Having more than one natural language is bad for the world

Natural language diversity is beautiful, but useless.

The fact that in poor countries a huge number of people do not speak the economically dominating language of the world (currently English), is a major obstacle to the development of those countries.

Despite us being in the information age, the people in those countries cannot fully benefit from it at all!

Teaching its people English should be the number one priority of any country. Without that, there can be no technological development. Everything else is secondary and can be learnt off the Internet once you know English.

And the most efficient way to do that, is that every country should create amazing free open source English learning material for their own language.

Also consider the European countries.

What big companies have been created in Europe in the past 50 years, that have not been bought out by American or Japanese companies?

The key problem is that there are so many small countries in Europe, that any startup has to deal with too many incompatible legislation and cannot easily sell to the hole of Europe.

So then a larger company from a more uniform country comes and eats it up!

So why can’t Europe unify its laws?

Because the countries are still essentially walled off by languages.

There isn’t true mobility of people between countries.

You just can’t go study or work in any other country (except for the UK, when it was still in the EU) without putting a huge effort into learning its language first.

Without this, there isn’t enough mixing to truly make cultures more uniform, and therefore allow the laws to be more uniform.

Europe can’t even unify basic things like a marriage registry, or the posting of parcels, which often get lost and require you to contact people who may not speak English.

For this reason, Europe will only continue to go downhill with the years, and the UK will continue to try and endosymbiose into a state of the USA.

It is the European Tower of Babel.

The Sapir–Whorf hypothesis is bullshit outside of poetry, and the ending of Arrival (2016) makes one want to puke, where learning a language changes not only your brain, but also Ciro’s precious laws!

Much more likely are To Serve Man / A Small Talent for War events!

Remember that those ideas come from a person who speaks 3.5 languages in 2019, and see absolutely no practical difference between them.

One interesting anecdote is that Ciro met his wife in French, and talking to her primarily in English feels really weird, so language does matter in love.

1.6.3. Ciro Santilli’s best random thoughts

These are "original" thoughts that Ciro had which at some point in the past amused him. Some would call them pieces of wisdom, others self delusion. All have likely been thought by others in the past, and some of them Ciro thinks to himself after a few years: "why did I like this back then??".

Quotes by other people can be found at: The best original quotes presenced by Ciro Santilli

After Ciro’s colleague was doing that in a project:

Chuck Norris can parse pseudocode.

On the theory vs practice of computer science:

Whereas Turing completeness is enough for mathematicians, humans need "run-on-Debian-complete".

How software engineers view science:

Science is the reverse engineering of nature.

On how human perception of media is completely unrelated to the computer’s transmission mechanism:

Media for humans is not byte streams. It is magic.

1.7. Ciro Santilli’s website

Ciro Santilli's website is hosted at https://cirosantilli.com.

1.7.1. How to develop Ciro Santilli’s website

Ciro’s website is powered by GitHub Pages and Jekyll Asciidoc.

The source code is located at: https://github.com/cirosantilli/cirosantilli.github.io

Build locally, watch for changes and rebuild automatically, and start a local server with:

git clone --recursive https://github.com/cirosantilli/cirosantilli.github.io
cd cirosantilli.github.io
bundle install
npm install
./run

Source: run

The website will be visible at: http://localhost:4000.

Tested on the latest Ubuntu.

Publish changes to GitHub pages:

git add -u
git commit -m 'make yourself look sillier'
./publish

Source: publish

GitHub forces us to use the master branch for the build output…​ so the actual source is in the branch dev.

Update the gems with:

bundle update
git add Gemfile.lock
git commit -m 'update gems'

His website was originally written in Markdown, however those were deprecated in favour of Asciidoctor when Ciro saw the light, rationale shown at: markdown-style-guide#use-asciidoc

GitHub pages is chosen instead of a single page GitHub README.adoc for the following reasons:

1.7.2. Unmigrated sections of the old version of Ciro Santilli’s website

It is interesting to see how your own ideas shift with time, and Ciro Santilli doesn’t think the following are very important anymore, so he was lazy to migrate them:

When he did the original website Ciro was in a "I must show off my skills to get a job mindset", but then after he landed a few jobs he moved to a "CV websites are useless, just do amazing projects and showcase them on your website to help them succeed" mindset.

1.7.3. Why Ciro Santilli removed Disqus comments from his website in 2019-05-04

Commit: https://github.com/cirosantilli/cirosantilli.github.io/commit/794705a201a79b5128934e69df85e3511655c03f

As Ciro started getting a lot of comments on his home page about China, he decided that Disqus does not scale, and that it would be more productive long term to remove it and point people to GitHub issues instead.

Upsides of removal:

  • Disqus discoverability is bad:

    • there is no decent way to search existing issues, you have to do JavaScript infinite loading + Ctrl + F. So every reply that he wrote is a waste of time, as it will never be seen again.

    • comments don’t have: decent URLs, titles, metadata like tags or open / close

  • Disqus archival is bad: http://web.archive.org/ does not work, and no one knows how to export the issues: https://www.archiveteam.org/index.php?title=Disqus

  • before, there were two places where people could comment, Disqus and GitHub issues. Now there is just one.

  • Disqus has ads if you ever reach enough traffic, which unacceptable, especially if the website owner don’t get paid for them! It also makes page loads slower, although that likely does not matter much.

Downsides:

  • people are more likely to comment on Disqus than to create an issue on GitHub, especially because most people use GitHub professionally. But this has the upside that there will be less shitposts as well.

  • with Disqus you can see all issues attached to a page automatically, which is nice. But for as long as Ciro is alive, he intends to just solve the issues, cross link between content and issues and tag things appropriately.

Ciro’s stance towards China hasn’t changed, and China comments and corrections about his website are still welcome as always.

Related issue: https://github.com/cirosantilli/cirosantilli.github.io/issues/37

1.7.4. DNS configuration of Ciro Santilli’s website

AKA how this GitHub page gets served under the domain: https://cirosantilli.com

Ciro only touches this very rarely, and always forgets and go into great pain whenever a change needs to done, so it is important to document it.

The last change was of 2019-07-07, when Ciro moved from the www subdomain https://www.cirosantilli.com to the APEX https://cirosantilli.com. A redirect is setup from the www subdomain to APEX.

GoDaddy DNS entries:

Type    Name    Value                   TTL
A       @       185.199.108.153         1 Hour
A       @       185.199.109.153         1 Hour
A       @       185.199.110.153         1 Hour
A       @       185.199.111.153         1 Hour
CNAME   www     cirosantilli.github.io  1 Hour

where the IPs are obtained from: https://help.github.com/en/articles/setting-up-an-apex-domain#configuring-a-records-with-your-dns-provider (archive).

Under https://github.com/cirosantilli/cirosantilli.github.io/settings

  • Custom domain: cirosantilli.com

  • Enforce HTTPS: checked

And the CNAME file is tracked in this repository: CNAME.

1.7.5. The CSS of Ciro Santilli’s website looks broken

That which does not exist, cannot be broken.

1.7.6. Ciro Santilli’s website is not mobile friendly

True Art cannot be consumed in mobile format.

1.7.7. Mathematics typesetting setup of Ciro Santilli’s website

Inline: \(\sqrt{2+2} = 2\)

Block: A test block equation

Equation 1. A test block equation
\[\sqrt{2+2} = 2\]

TODO: move to https://github.com/cirosantilli/asciidoctor-katex-2 once major TODOs there are done.

1.7.8. Media rationale of Ciro Santilli’s website

1.7.8.1. Keeping pages light

It is true that one image is worth a thousand words, but unfortunately it is also true that one image takes up at least as much bytes as a thousand words!

Having one single page to rule them all is of course the ideal setup for a website, as you can Ctrl + F one ToC and quickly find what you want.

And, with Linux Kernel Module Cheat Ciro noticed that it is very hard to write intelligent prose that becomes larger than reasonable to load on a single webpage.

However, if there are too many images on the page, the loading of the last images would take forever in case users want to view the last sections.

There are two solutions to that:

Ciro is still deciding between those two. The traditional approach works for sure but loses the one page to rule them all benefits.

The innovative approach will work for interactive viewing, but archive.org will fail to load the images for example, and there may be other unforseen consequences.

Wikimedia Commons is awesome and automatically converts and serves smaller versions of images, so always choose the smallest images size needed by the output document. Readers can then find the higher resolution versions by following the page source.

1.7.8.2. Where to store images

Since images are large, they bring the following challenges:

  • keeping images in the main Git repository with text content makes the repository huge and slow to clone, and should not be done

  • storing and serving images could cost us, which we want to avoid

To solve those problems, the following alternatives appear to be stable enough and should be used decreasing preference:

  • for all images, use the separate GitHub repository: https://github.com/cirosantilli/media

    This way, the entire website is relies on a single third party: GitHub, so we have a simple single point of failure.

    We are at the mercy of GitHub’s 1GB size policy: https://help.github.com/en/articles/what-is-my-disk-quota, but it will take a while to hit that.

    GitLab however has a 10Gb maximum size: https://about.gitlab.com/2015/04/08/gitlab-dot-com-storage-limit-raised-to-10gb-per-repo/ so we could move there is we ever blow up 1Gb on GitHub.

    Both GitLab and GitHub allow uploading files through the web UI, so downloading a large repo is never needed to contribute.

    GitHub does not serve videos like it does images however as of 2019.

  • Wikimedia Commons for videos if the following conditions are met:

    • in scope: "educational material in a broad sense", but not e.g. "Private image collections, e.g. private party photos, photos of yourself and your friends, your collection of holiday snaps and so on.". I don’t think they will be too picky even with low quality photos.

    • allowed format, e.g. images or videos, but not ZIPs

    • allowed license: CC BY SA, but no fair use

      Since Wikimedia Commons has a higher level of curation and is an educational not-for-profit, it is the method most likely to remain available for the longest time.

      For this reason, we highly recommend uploading any acceptable files there as well as an additional backup.

      The downside is that its tooling is not as good, e.g. there are a bunch of messy unofficial tools for batch operations, and upload takes more effort.

      Another downside of Wikimedia Commons is that while we can choose the basename of files, it also adds some extra SHA crap to the beginning of URLs, making them harder to predict.

  • https://archive.org for anything else, e.g. videos that Wikimedia commons does not accept.

    All content will be tracked under the cirosantilli collection: https://archive.org/details/cirosantilli

    archive.org has a very convenient upload and lax requirements. The generated URLs are predictable (single SHA prefix for the entire collection).

    Never trust a website that is not on GitHub pages, for-profit companies will take down everything immediately as soon as it stops making them money.

    Every external link to non-GitHub pages must be archived. And GitHub links must be forked.

    We should also backup images that Wikimedia Commons does not accept here in addition to the https://github.com/cirosantilli/media repository.

The following alternatives seem impossible because Ciro could not find if they expose direct links to the images:

The following do have direct links:

For videos, YouTube does not allow download, even of Creative Commons videos so uploading only there is not acceptable as it prevents reuse:

1.7.9. Download Ciro’s website for offline viewing

Not perfect yet, but doing some progress, currently xref2 links resolve to .html correctly:

CIROSANTILLI_COM_XREF2_SERVERLESS=1 ./build
xdg-open _site/index.html

https://stackoverflow.com/questions/26778329/running-jekyll-generated-files-without-jekyll-local-server

TODO: download all resources, including CSS and JavaScript. Images are already half way because basically all already go through image2. External CSS and JavaScript would require extending Jekyll with a tag plugin, which should not be hard.

Download all images download for development is already possible with;

CIROSANTILLI_COM_OFFLINE_DOWNLOAD=1 ./build

And after the download was done once before, generate output that uses the downloaded files instead of remote ones:

CIROSANTILLI_COM_OFFLINE_USE=1 CIROSANTILLI_COM_XREF2_SERVERLESS=1 ./build
xdg-open _site/index.html

or when running the development server:

CIROSANTILLI_COM_OFFLINE_USE=1 ./run
xdg-open http://localhost:4000

TODO: for some reason when I access How to use an Oxford Nanopore MinION to extract DNA from river water and determine which bacteria live in it in offline mode on the browser at 7c119de0dcf263f5cd24ceb5e171a4bfd433c7e7 + 1 I get a few messages:

[2019-10-06 23:23:28] ERROR Errno::ECONNRESET: Connection reset by peer @ io_fillbuf - fd:17
     /home/ciro/.rvm/rubies/ruby-2.6.0/lib/ruby/2.6.0/webrick/httpserver.rb:82:in `eof?'
     /home/ciro/.rvm/rubies/ruby-2.6.0/lib/ruby/2.6.0/webrick/httpserver.rb:82:in `run'
     /home/ciro/.rvm/rubies/ruby-2.6.0/lib/ruby/2.6.0/webrick/server.rb:307:in `block in start_thread'

Related: https://github.com/jekyll/jekyll/issues/6899

1.8. Ciro Santilli’s skills

1.8.1. Ciro Santilli’s documentation superpowers

Ciro Santilli has the power to document stuff in a way that makes using them awesome.

If your project does something awesome, hiring Ciro means that more people will be able to notice that it is actually awesome, and use it.

He likes to do this in parallel to contributing new features, quickly switching between his "developer" and "technical documentor" hats.

This means of course that he will develop new features a bit slower than others, but he feel it is more valuable if end users can actually use your project in the first place.

His technique is to provide upfront extremely interactive and reproducible getting started setups that immediately show the key value of the project to users.

He backs those setups with:

  • scripts that automate the setup much as possible to make things enjoyable and reproducible

  • a detailed description of the environment in which he tested: which OS, version of key software, etc.

  • a detailed description of what is expected to happen when you take an action, including known bugs with links to bug reports

  • theory and rationale on the sections after the initial getting started, but always finely interspersed with concrete examples

  • all docs contained in a Git-tracked repo, with the ability to render to a single HTML with one TOC

  • short sentences and paragraphs, interspersed with many headers, lists and code blocks

While he create this setup, he inevitably start to notice and fix:

  • bugs

  • annoyances on the public interface of the project

  • the devs were using 50 different local scripts to do similar things, all of them semi-broken and limited. Every new hire was copying one of those local scripts, and hacking it up further.

  • your crappy build / test / version control setup

Exploiting this skill, however, requires you to trust him.

When he tells to managers that he’s good at documenting, they always say: great, we need better documentation! But then, one of the following may happen:

  • managers forget that they wanted good documentation and just tell him to code new features as fast as possible

  • they don’t let him own the getting started page, but rather and expect him to try and fix the existing crappy unfixable existing getting started, without stepping on anyone’s pride in the process >:-)

    This makes him tired, and less likely to do a good job.

    Good documentation requires a large number of small iterative reviews, and detailed review of every line is not always feasible.

    Too many cooks.

A prime example of this ability is his Linux Kernel Module Cheat

See also: The best articles by Ciro Santilli.

1.8.2. Ciro Santilli’s natural languages skills

When asked, Ciro likes to say that he speaks something between 1.5 and 3.5 languages in total, depending on how you count, because Portuguese, French and English are 99.99% the same, and Chinese is completely different but Ciro only knows about 50% of it if counted optimistically.

1.9. Ciro Santilli’s psychology and physiology

Ciro Santilli’s energy throughout the day varies as follows:

  • morning: highest

  • after lunch: brain death. Possibly due to Ciro’s partial Spanish descent?

  • late afternoon and evening: can do some stuff

Ciro has low tolerance to sleep deprivation which makes him very irritable, and low ability to sleep if there is any light.

Ciro has olfactory synesthesia for star anise (八角, bajiao), which is widely used in Chinese cuisine and makes Ciro think uncontrollably of the color blue. Ciro does not have any other known synesthesias.

Ciro is a reptilian-like being with cold hands and feet and low blood pressure. For this reason he believes that he will die of cancer or some respiratory problem. If the Chinese government doesn’t get him first that is. This also partly explains why Ciro is not a big fan of swimming.

Besides Chinese food, Ciro really likes eating fruits and nuts, maybe partly because he was born in Brazil, and partly because of monkey nature, see his Chinese name. At home is is known as "水果大王" (the big king of the fruits).

1.9.1. Effortless effort 無爲

https://en.wikipedia.org/wiki/Wu_wei

Ciro feels that all really important and productive activities come spontaneously, without being internally forced upon people.

You may say that this is because Ciro is lazy, but Bill says (archive) this isn’t necessarily bad:

I will always choose a lazy person to do a difficult job because a lazy person will find an easy way to do it.

You may also say that Ciro is an idealist, because what to do when the food will run out and you have to hunt? To which Jesus replies at Matthew 6:25-34 "Do Not Worry" (archive):

Therefore I tell you, do not worry about your life, what you will eat or drink; or about your body, what you will wear. Is not life more than food, and the body more than clothes? Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them. Are you not much more valuable than they? Can any one of you by worrying add a single hour to your life?

And why do you worry about clothes? See how the flowers of the field grow. They do not labor or spin. Yet I tell you that not even Solomon in all his splendor was dressed like one of these. If that is how God clothes the grass of the field, which is here today and tomorrow is thrown into the fire, will he not much more clothe you - you of little faith? So do not worry, saying, "What shall we eat?" or "What shall we drink?" or "What shall we wear?" For the pagans run after all these things, and your heavenly Father knows that you need them. But seek first his kingdom and his righteousness, and all these things will be given to you as well. Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own.

1.9.2. Ciro Santilli’s bad old event memory

Ciro Santilli has a bad memory for events that happened a medium time ago, for example in order of months / years. Especially if they are one-off things that have no relation to anything else.

For example, Ciro never remembers which places he travelled to just once, and who was in each trip! He has images of several places he travelled to in his head, and would recognize them, but he just doesn’t know where they were!

The same goes for scenes from movies and passages from music, which explains why Ciro’s Art consumption focuses on innovative discrete "what happened" and "general gist" ideas, rather than, analog details such as colors and shapes.

Going back even further in time, Ciro starts to forget the less close friends he had, because the events start to fade away.

Paradoxically however, Ciro believes that this bad memory is one of his greatest strengths and key defining characteristics, because it leads Ciro to want to write down every interesting thing he learns, which motivated Write free books to get famous website.

It also somewhat leads Ciro to like Physics and Mathematics, because in these fields you can deduce everything from very few base principles, so if you forget them, it does not matter that much as you can re-deduce stuff over and over.

1.10. Ciro Santilli’s biography

Ciro Santilli was born in Brazil in a small / medium city in the State of São Paulo in 1989 AD.

In the year 2000, Ciro lived with his parents for 10 months in the Coventry, United Kingdom because his father took some courses at the university of Warwick. This was Ciro’s most important educational experience, because it taught him the Holy Language of English, which infinitely expanded Ciro’s Internet horizons, and shaped Ciro’s Having more than one natural language is bad for the world philosophy. When he came back to Brazil, Ciro skipped dozens of levels in his English school, and was put to study with much older teenagers who marveled at Ciro’s incredibly cute, but since lost, British accent.

After Coventry, Ciro’s family lived in the city of Santos, São Paulo, Brazil, which is the nearest beach city to the city of São Paulo, and for this reason the largest port of Latin America in 2018, and a popular local tourist destination. Ciro lived there until he went to the University of São Paulo, Brazil. Ciro idolizes Santos as the perfect location to live nature-wise due to its amazing wide sandy beach, in which Ciro spent endless hours walking on the sand and on the largest beachfront garden in the world (archive), meditating, and playing some soccer after school was over. Santos is also the city where Pelé first played professionally.

Panoramica Santos
Figure 9. Panoramic view of Santos' beach line taken in 2009. Source.
800px Canal 5 adentrando na praia de Santos
Figure 10. Canal 5 on the beach, one of Santo’s 7 old Canals. Don’t worry, they’re pretty clean nowadays, and serve as handy reference points in town, as well as being surrounded with nice trees that provide shade and drop small inedible purple fruit that will stain your car for all eternity. Source.

1.10.1. Ciro Santilli’s formal education

Ciro Santilli did a double degree program, and obtained degrees in both:

Ciro participated in a double degree program, so he obtained have engineering degrees in both:

Despite studying in great institutions with great teachers, Ciro feels that:

This motivated Ciro to work on Write free books to get famous website.

1.10.2. Ciro Santilli’s knee

If Achilles' had his heel, Ciro had his knee.

Just after arriving in France for École Polytechnique, the boys were playing indoor soccer, and to impress the girls Ciro was playing really hard, even took off his shirt, and suddenly when he was running by himself his knee snapped, he fell and it hurt like hell.

Ciro was on crutches for a few weeks, but the inflammation went away, but then he tried to play more soccer, but the knee was not as stable as before, and so he gave up. And for some reason it was not visible on the tomography.

So from this day on Ciro gave up on all interesting sports, and confined himself to more repetitive stuff like gym weights and cycling.

This defect is likely genetic since a close relative had similar problems.

But oh well, his then not-even girlfriend was impressed enough by the soccer or sorry enough for the sucker to marry him, so it worked out.

1.11. Ciro Santilli’s ideal city to live in

Ciro’s ideal city to live in contains the following in order of decreasing importance:

Could California be Ciro’s Mecca?

2. Physics

https://en.wikipedia.org/wiki/Physics

Ciro Santilli doesn’t know physics. He writes about it partly to start playing with some scientific content for: Write free books to get famous website, partly because this stuff is just amazingly beautiful. He is especially curious about Particle physics and condensed matter.

Physics is the Art of predicting the future by modelling the world with Mathematics.

Every science is Physics in disguise, but the number of objects in the real world is so large that we can’t solve the real equations in practice.

Luckily, due to emergence, we can use uglier higher level approximations of the world to solve many problems, with the complex limits of applicability of those approximations.

Therefore, such higher level approximations are highly specialized, and given different names such as:

As of 2019, all known physics can be described by two theories:

Unifying those two into the Theory of everything one of the major goals of modern physics.

2.1. The most important physics experiments

Videos should be found / made for all of those: Videos of all key physics experiments

2.1.1. Speed of light experiments

2.1.2. Michelson-Morley experiment

https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment

2.1.3. Double slit experiment

https://en.wikipedia.org/wiki/Double-slit_experiment

When done with individual electrons it amazingly confirms the wave particle duality of quantum mechanics.

TODO here are a few non well specified demonstrations:

2.1.4. Blackbody radiation experiment

https://en.wikipedia.org/wiki/Black-body_radiation

TODO original setups.

Led to: Planck’s law

2.1.5. Compton scattering

https://en.wikipedia.org/wiki/Compton_scattering

https://www.youtube.com/watch?v=uICnnfYHYJ4 "Compton Scattering" by "Compton Scattering" experiment with a Cesium-137 source.

Classic theory predicts that the output frequency must be the same as the input one since the electromagnetic wave makes the electron vibrate with same frequency as itself, which then irradiates further waves.

But the output waves are longer: https://www.youtube.com/watch?v=WR88_Vzfcx4 "L3.3 Compton Scattering" by "MIT OpenCourseWare", because photons are discrete and energy is proportional to frequency.

The formula is exactly that of two relativistic billiard balls colliding, which further suggests that photons are real.

Therefore this is evidence that photons exist and have momentum.

2.1.6. Photoelectric effect

https://en.wikipedia.org/wiki/Photoelectric_effect

No matter how hight the wave intensity, if it the frequency is small, no photons are removed from the material.

This is different from classic waves where energy is proportional to intensity, and coherent with the existence of photons and the Planck-Einstein relation.

2.1.7. Lamb shift

https://en.wikipedia.org/wiki/Lamb_shift

2s / 2p energy split, not predicted by the Dirac Equation, but explained by Quantum Electrodynamics, which is one of the first great triumphs of that theory.

2.2. Particle physics

https://en.wikipedia.org/wiki/Particle_physics

Currently an informal name for the Standard model

Chronological outline of the key theories:

2.2.1. Standard model

https://en.wikipedia.org/wiki/Standard_Model

As of 2019, the more formal name for Particle physics, which is notably missing General relativity to achieve the Theory of everything.

2.2.2. Maxwell’s equations

https://en.wikipedia.org/wiki/Maxwell%27s_equations

Unified all previous electro-magnetism theories into one equation.

Explains the propagation of light as a wave, and matches the previously known relationship between the speed of light and electromagnetic constants.

The equations are a limit case of the more complete Quantum Electrodynamics, and unlike that more general theory account for the quantization of Photon.

TODO: what does it mean that it is coherent with Special relativity?

The equations are a system of Partial differential equations.

The system consists of 6 unknown functions that map 4 variables: time t and the x, y and z positions in space, to a real number:

  • \(E_x(t, x,y,z)\), \(E_y(t, x,y,z)\), \(E_z(t, x,y,z)\): directions of the electric field \(\functionDomain{\E}{\RFour}{\RThree}\)

  • \(B_x(t, x,y,z)\), \(B_y(t, x,y,z)\), \(B_z(t, x,y,z)\): directions of the magnetic field \(\functionDomain{\B}{\RFour}{\RThree}\)

and two known input functions:

  • \(\functionDomain{\rho}{\RThree}{\R}\): density of charges in space

  • \(\functionDomain{\J}{\RThree}{\RThree}\): current vector in space. This represents the strength of moving charges in space.

Due to the conservation of charge however, those input functions have the following restriction:

Equation 2. Charge conservation
\[\dv{\rho}{t} + \divergence{\mathbf{\J}} = 0\]

Also consider the following cases:

  • if a spherical charge is moving, then this of course means that \(\rho\) is changing with time, and at the same time that a current exists

  • in an ideal infinite cylindrical wire however, we can have constant \(\rho\) in the wire, but there can still be a current because those charges are moving

    Such infinite cylindrical wire is of course an ideal case, but one which is a good approximation to the huge number of electrons that travel in a actual wire.

The goal of finding \(\E\) and \(\B\) is that those fields allow us to determine the force that gets applied to a charge via the Lorentz force equation:

Equation 3. Lorentz force equation
\[\text{force_density} = \rho \E + \J \times \B\]

and then to find the force we just need to integrate over the entire body.

Finally, now that we have defined all terms involved in the Maxwell equations, let’s see the equations:

Equation 4. Gauss' law
\[\divergence{\E} = \frac{\rho}{\vacuumPermittivity}\]
Equation 5. Gauss’s law for magnetism
\[\divergence{\B} = 0\]
Equation 6. Faraday’s law of induction
\[\curl{\E} = -\dv{\B}{t}\]
Equation 7. Ampère’s circuital law
\[\curl{\B} = \vacuumPermeability \left(\J + \vacuumPermittivity \dv{E}{t} \right)\]

and you should review the interpretation of divergence \(\divergence{}\) and curl \(\curl{}\):

  • divergence: how much fluid goes out or into a point

  • curl: points in the direction in which a wind spinner spins fastest

For numerical algorithms and to get a more low level understanding of the equations, we can expand all terms to the simpler and more explicit form:

\[\dv{E_x}{x} + \dv{E_y}{x} + \dv{E_z}{x} = \frac{\rho}{\vacuumPermittivity} \\ \dv{B_x}{x} + \dv{B_y}{x} + \dv{B_z}{x} = 0 \\ \dv{E_z}{y} - \dv{E_y}{z} = -\dv{B_x}{t} \\ \dv{E_x}{z} - \dv{E_z}{x} = -\dv{B_y}{t} \\ \dv{E_y}{x} - \dv{E_x}{y} = -\dv{B_z}{t} \\ \dv{B_z}{y} - \dv{B_y}{z} = \vacuumPermeability \left(J_x + \vacuumPermittivity \dv{E_x}{t} \right) \\ \dv{B_x}{z} - \dv{B_z}{x} = \vacuumPermeability \left(J_y + \vacuumPermittivity \dv{E_y}{t} \right) \\ \dv{B_y}{x} - \dv{B_x}{y} = \vacuumPermeability \left(J_z + \vacuumPermittivity \dv{E_z}{t} \right) \\\]

As you can see, this expands to 8 equations, so the question arises if the system is over-determined because it only has 6 variables. As explained at: https://en.wikipedia.org/wiki/Maxwell%27s_equations#Overdetermination_of_Maxwell’s_equations however, this is not the case, because if the first two equations hold for the initial condition, then they also hold for all time, so they can be essentially omitted.

It is also worth noting that the first two equations don’t involve time derivatives. Therefore, they can be seen as spacial constraints.

2.2.2.1. Coulomb’s law

https://en.wikipedia.org/wiki/Coulomb%27s_law

Static case of Maxwell’s law for electricity only.

Is implied by Gauss' law: https://physics.stackexchange.com/questions/44418/are-the-maxwells-equations-enough-to-derive-the-law-of-coulomb

2.2.2.2. Maxwell’s equations in 2D

TODO it would be awesome if we could de-generalize the equations in 2D and do a JavaScript demo of it!

Not sure it is possible though because the curl appears in the equations:

2.2.2.3. Existence and uniqueness of solutions to Maxwell’s equations

TODO: I’m surprised that the Wiki page barely talks about it, and there are few Google hits too! A sample one: https://www.researchgate.net/publication/228928756_On_the_existence_and_uniqueness_of_Maxwell’s_equations_in_bounded_domains_with_application_to_magnetotellurics

Special relativity

2.2.4. General relativity

https://en.wikipedia.org/wiki/General_relativity

TODO.

2.2.5. Quantum mechanics

2.2.5.1. Schrodinger equation

https://en.wikipedia.org/wiki/Schr%C3%B6dinger_equation

The Partial differential equations of non-relativistic Quantum mechanics.

TODO show some sample numerical solutions in JavaScript and applications such as deriving hydrogen energy levels.

2.2.5.2. Planck’s law

https://en.wikipedia.org/wiki/Planck%27s_law

Used to explain: Blackbody radiation experiment

Good explanation of how discretization + energy increases with frequency explains the curve: https://youtu.be/KabPQLIXLw4?list=PL193BC0532FE7B02C&t=7 "Quantum Mechanics 2 - Photons" by "viascience". You need more and more energy for small wavelengths, each time higher above the average energy available.

TODO full equation derivation.

2.2.5.3. Spin

https://en.wikipedia.org/wiki/Spin_(physics)

TODO

https://www.youtube.com/watch?v=6sR6RV2znXI&list=PL193BC0532FE7B02C&index=17 "Quantum Mechanics 9a - Photon Spin and Schrödinger’s Cat I" by "viascience" shows nicely how:

  • Photon spin can be either linear or circular

  • the linear one can be made from a superposition of circular ones

  • straight antennas produce linearly polarized photos, and Helical antennas circularly polarized ones

  • a jump between 2s and 2p in an atom changes angular momentum. Therefore, the photon must carry angular momentum as well as energy.

2.2.6. Why do symmetries such as SU(3)×SU(2)×U(1) matter in particle physics?

TODO.

Physicists love to talk about that stuff, but no one ever has the guts to explain it into enough detail to show its beauty.

2.2.7. Applications of particle physics

There aren’t any, it’s useless:

2.2.8. Particle physics bibliography

Some light YouTube channels, good for the first view, but which don’t go into enough detail to truly show the subject’s beauty:

2.2.9. Dirac Equation

https://en.wikipedia.org/wiki/Dirac_equation

2.2.9.1. How does Dirac’s equation model spin?

This tutorial is awesome: https://www.youtube.com/watch?v=OCuaBmAzqek "Quantum Mechanics 12a - Dirac Equation I" by "viascience" published 2015-12-19.

2.2.10. Quantum Electrodynamics

https://en.wikipedia.org/wiki/Quantum_electrodynamics

Theory that describes electrons and photons really well, and as Feynman puts it, accounts very precisely for all physical phenomena we have ever observed, except for gravity and nuclear physics (including the laughter of the crowd ;-)).

2.2.10.1. What does it mean that photons are force carriers for electromagnetism?

https://physics.stackexchange.com/questions/61095/photon-as-the-carrier-of-the-electromagnetic-force

TODO find / create decent answer.

2.2.10.2. Quantum Electrodynamics bibliography
2.2.10.2.1. Richard Feynman Quantum Electrodynamics Lecture at University of Auckland in 1979

Can’t find official video, so going with the upload by https://www.youtube.com/watch?v=eLQ2atfqk2c&list=PL8590A6E18255B3F4 by "ReasonPublic" for now…​

2.2.11. Quantum Chromodynamics

https://en.wikipedia.org/wiki/Quantum_chromodynamics

https://www.youtube.com/watch?v=FoR3hq5b5yE "Quarks, Gluon flux tubes, Strong Nuclear Force, & Quantum Chromodynamics" by "Physics Videos by Eugene Khutoryansky". Some decent visualizations of the field lines.

2.2.12. Photon

https://en.wikipedia.org/wiki/Photon

Initially light was though of as a wave because it experienced interference as shown by experiments such as:

But then, some key experiments also start suggesting that light is made up of discrete packets:

This duality is fully described mathematically by Quantum Electrodynamics.

2.2.12.1. Single photon production and detection experiments

You can’t get more direct than this in terms of proving that photons exist!

TODO find decent experiment video.

The detection apparatus is called a photomultiplier: https://en.wikipedia.org/wiki/Photomultiplier

There are two types:

https://www.youtube.com/watch?v=dyXq1u87qew

Single photon production is described briefly at: https://youtu.be/F1GaTizdcb8?t=47 "How do you produce a single photon?" by "Physics World" which mentions parametric down conversion: https://en.wikipedia.org/wiki/Spontaneous_parametric_down-conversion

2.2.12.1.1. Photomultiplier tube

https://en.wikipedia.org/wiki/Photomultiplier_tube

Feynman likes them, here he describes the tube one: https://youtu.be/eLQ2atfqk2c?t=2198 "QED: Photons -- Corpuscles of Light -- Richard Feynman (1/4)" (University of Auckland, 1979) by "ReasonPublic".

It uses the Photoelectric effect multiple times to produce a chain reaction.

2.2.12.1.2. Silicon photomultiplier

https://en.wikipedia.org/wiki/Silicon_photomultiplier

Here is a vendor showcasing their device. They claim in that video that a single photon is produced and detected: https://www.youtube.com/watch?v=dyXq1u87qew "How to use an SiPM - Experiment Video" by "SensLTech".

2.2.12.2. Planck-Einstein relation

https://en.wikipedia.org/wiki/Planck%E2%80%93Einstein_relation

Photon energy is proportional to its frequency:

\[energy = (plancks \space constant) * (frequency)\]

or with common weird variables:

\[E = h * \nu\]

This only makes sense if the Photon exists, there is no classical analogue.

Experiments that suggest this:

2.3. Theory of everything

https://en.wikipedia.org/wiki/Theory_of_everything

As of 2019, the Standard model and General relativity are incompatible. Once those are unified, we will have one equation to describe the entirety of Physics.

The current state of Physics has been the result of several previous unifications as shown at: https://en.wikipedia.org/wiki/Theory_of_everything#Conventional_sequence_of_theories so it is expected that this last missing unification is likely to happen one day, potentially conditional on humanity having enough energy to observe new phenomena.

2.4. Computational Physics

https://en.wikipedia.org/wiki/Computational_physics

The intersection of two beautiful arts: coding and Physics!

Computational physics is a good way to get valuable intuition about the key equations of physics, and train your numerical analysis skills:

2.5. Philosophy of Science

2.5.1. Never trust an experiment that is not supported by a good theory

Not the usual bullshit you were expecting right?

I also like how Monod "learned from other students a little older than himself, rather than from the faculty.", read somewhere else that it is because faculty is more likely outdated.

2.5.2. Physics and the illusion of life

The natural sciences are not just a tool to predict the future.

They are a reminder that the lives that we live daily are mere illusions, just like Buddhists and Hinduists say.

We as individuals nothing about the materials that we touch every day, nor more importantly how our brain and cells work.

Everything is out of our control.

The natural sciences allow us peek, with huge concentrated effort, into tiny little bits a little of those unknowns, and blow our minds as we notice that we don’t know anything.

Every one or two week Ciro Santilli remembers that I and everything I touch are just a bunch of atoms, and that is an amazing feeling.

3. Mathematics

https://en.wikipedia.org/wiki/Mathematics

Here is a more understandable description of the semi-satire that follows: https://math.stackexchange.com/questions/53969/what-does-formal-mean/3297537#3297537https://math.stackexchange.com/questions/53969/what-does-formal-mean/3297537#3297537

A beautiful game played on strings, which mathematicians call "theorems".

You start with a very small list of:

  • certain arbitrarily chosen initial strings, which mathematicians call "axioms"

  • rules of how to obtain new strings from old strings, called "rules of inference" Every transformation rule is very simple, and can be verified by a computer.

Using those rules, you choose a target string that you want to reach, and then try to reach it. Before the target string is reached, matematicians call it a "conjecture".

Mathematicians call the list of transformation rules used to reach a string a "proof".

Since every step of the proof is very simple and can be verified by a computer automatically, the entire proof can also be automatically vefified by a computer very easily.

Finding proofs however is undoubtedly an NP-hard problem.

Most mathematicians can’t code or deal with the real world in general however, so they haven’t created the obviously necessary: Website front-end for a mathematical formal proof system.

The fact that Mathematics happens to be the best way to describe Physics and that humans can use physical intuition heuristics to reach the NP-hard proofs of mathematics is one of the great miracles of the universe.

3.1. Formalization of mathematics

https://math.stackexchange.com/questions/53969/what-does-formal-mean/3297537#3297537

The one true definition of Mathematics.

3.2. Partial differential equations

https://en.wikipedia.org/wiki/Partial_differential_equation

Some of the most important examples include:

The Finite element method is one of the most common ways to solve PDEs in practice.

3.2.1. Existence and uniqueness of solutions of partial differential equations

If you have a PDE that models physical phenomena, it is fundamental that:

  • there must exist a solution for every physically valid initial condition, otherwise it means that the equation does not describe certain cases of reality

  • the solution must be unique, otherwise how are we to choose between the multiple solutions?

Unlike for ordinary differential equations which have the Picard–Lindelöf theorem, the existence and uniqueness of solution is not well solved for PDEs. For example, Navier–Stokes existence and smoothness was one of the Millennium Prize Problems.

3.3. Numerical analysis

https://en.wikipedia.org/wiki/Numerical_analysis

Not the most beautiful Mathematics, but fundamentally useful since we can’t solve almost any useful equation without computers!

The entire field comes down to estimating the true values with a known error bound, and creating algorithms that make those error bounds asymptotically smaller.

3.3.1. Finite element method

https://en.wikipedia.org/wiki/Finite_element_method

TODO understand, give intuition, justification of bounds and JavaScript demo.

3.4. Mathematics bibliography

https://github.com/vEnhance/napkin Evan Chen’s (陳誼廷) Infinite Napkin. 800+ page PDF with source on GitHub claiming to try and teach the beauty of modern maths for high schoolers. Fantastic project!!!

3.5. Mathematicians

https://en.wikipedia.org/wiki/Mathematician

Poet, scientists and warriors all in one? Conquerors of the useless.

A wise teacher from University of São Paulo, Brazil once told the class Ciro Santilli attended an anecdote about his life:

I used to want to learn Mathematics.

But it was very hard.

So in the end, I became an engineer, and found an engineering solution to the problem, and married a Mathematician instead.

It turned out that, about 10 years later, Ciro ended up following this advice, unwittingly.

purity
Figure 11. xkcd 435. Source.

4. Art

https://en.wikipedia.org/wiki/Art

Stuff that is beautiful but useless because it does not make food or houses cheaper.

Or from Ciro Santilli’s best random thoughts:

Without technology, one cannot survive. Without art, one cannot live.

But that sure enough has a Jesus semi-precursor, and likely many others from Matthew 4:4:

Man shall not live on bread alone, but on every word that comes from the mouth of God.

There is some art however that lives in the fine intersection between beauty and usefulness:

4.1. The best video game content of all time

The most beautiful TAS content ever made are:

4.1.1. Magic the Gathering

https://en.wikipedia.org/wiki/Magic:_The_Gathering

Magic is the best card game of all time. Ciro Santilli agrees with this fact, and this has nothing to do with the nostalgia factor of having played it when he was a teenager.

However, Magic has one flaw: the cards of old formats (Legacy and Modern), which are the really interesting ones, are fucking expensive. Ciro thinks this is idiotic, and that Wizards should sell all cards individually with unlimited supply and all with the same prices, especially online where there are no printing costs. But because Wizards made the silly promise never to reprint certain cards with the reserved list in 1994, they can’t even correct this mistake legally!

There however one good solution to that: watch people who have nothing better to do in their lives play on YouTube, notably ChannelFireball.

Like in Mathematics, the most beautiful decks are those that do crazy things:

  • infinite combos

  • semi-infinite combos that allow you to likely draw your entire deck or deal 20 damage

  • all-in decks that either win or lose on turn two

  • and lands

It is also really interesting to watch as new sets as spoiled and try to guess if certain cards will have any impact on the Modern or Legacy metagame.

Here are some cool good decks:

Competitive commander is also amazing, see for example this channel; Playing With Power MTG channel.

Urza’s block is the most epic of all. Ridiculous power level and epic art, and happened just before Ciro Santilli started playing, so Ciro saw some cards from it floating around, but not many, and it felt mystical.

In 2019, a paper proved that MTG is Turing Complete with a legacy legal deck. Live demo with some hand waving: https://www.youtube.com/watch?v=pdmODVYPDLA "I Built a COMPUTER in Magic: The Gathering" by "Because Science" published in Oct 31, 2019. TODO: how is this reflected in the rules? https://github.com/cirosantilli/cirosantilli.github.io/issues/42

4.2. The best YouTube channels

4.2.1. Web of Stories

https://www.youtube.com/user/webofstories "Web of Stories - Life Stories of Remarkable People". 1-2 to hour long interviews, the number of Nobel prize winners is off-the-charts.

4.3. The best television series of all time

BBC 1979-1982 adaptations of John le Carré’s novels are the best miniseries ever made:

They are the most realistic depiction of spy craft ever done.

4.4. The best movies of all time

Ciro has already watched all the best films in history, and as a result any of those new movies that is full of clichés and has no innovative aspect at all (99.99999% of all modern movies) makes Ciro want to puke and to start Googling Encyclopedia Dramatica to classify as many clichés as possible.

Movies that are very expensive to make tend to be bad, because they have to make returns and thus appeal to a large amorphous population without any specialization. See e.g. Primer (2004) and The Man From Earth (2007).

4.4.1. Once upon a time in the west (1968)

https://en.wikipedia.org/wiki/Once_Upon_a_Time_in_the_West

Has the best opening scene of all time.

Top quotes:

4.4.2. Battle of Algiers (1966)

https://en.wikipedia.org/wiki/The_Battle_of_Algiers

There’s nothing like seeing the hypocrisy of the "Liberté, Égalité, Fraternité" people destroyed.

Interesting how Algeria now supports China’s Xinjiang policy in 2019.

4.4.3. The Godfather (1972) and The Godfather Part II (1974)

Part 3 (1990) https://en.wikipedia.org/wiki/The_Godfather_Part_III is an abomination and disgrace to the bilogy.

4.4.4. Primer (2004)

https://en.wikipedia.org/wiki/Primer_(film)

Things that can be understood are boring.

4.4.5. Other very good movies

4.4.5.1. The Man From Earth (2007)

The Man from Earth (2007).

Low budget.

Good theory of Jesus.

4.5. The best music albums of all time

4.5.1. The best modern instrumental Western music albums of all time

4.5.1.1. Surfing with the Alien (1987) by Joe Satriani

https://en.wikipedia.org/wiki/Surfing_with_the_Alien

4.5.1.2. Secrets (1989) by Allan Holdsworth

https://en.wikipedia.org/wiki/Secrets_(Allan_Holdsworth_album)

4.5.1.3. Romantic Warrior (1976) by Return to Forever

https://en.wikipedia.org/wiki/Romantic_Warrior

4.5.1.4. Maiden Voyage (1965) by Herbie Hancock

https://en.wikipedia.org/wiki/Maiden_Voyage_(Herbie_Hancock_album)

4.5.1.5. Aurora (1976) by Jean-Luc Ponty

https://en.wikipedia.org/wiki/Aurora_(Jean-Luc_Ponty_album)

4.5.2. The best Chinese traditional instrumental music albums of all time

List at: https://github.com/cirosantilli/china-dictatorship#music

4.6. The best quotes of all time

Ciro’s best quotes selected by no one other than Ciro can be found at: Ciro Santilli’s best random thoughts.

Related to technology:

4.6.1. Jesus

https://en.wikipedia.org/wiki/Jesus

That self blame, imminent end of the world and hatred for tax collectors stuff is a bit over the top, you should chill man.

But please keep the parables coming:

Proverbs 27:17:

As iron sharpens iron, so one person sharpens another.

Matthew 4:19:

Follow me, and I will make you fishers of men.

Matthew 7:13:

Enter through the narrow gate. For wide is the gate and broad is the road that leads to destruction, and many enter through it.

Ciro really likes this one, because he feels that where many people go, it is useless to go again. It is much better to explore that which few can do, but which many will need.

4.6.2. The best original quotes presenced by Ciro Santilli

Ciro presenced, so likely paraphrased and anonymized, and likely originally said by someone else famous without Ciro knowing it due to limited culture:

Sometimes, even if our end goals are too far, the side effects of trying to reach them can have meaningful impact.

By Teacher R. And I should complete: if the goals are not too far, you won’t even have side effects so show in the end!

5. Stack Overflow

https://en.wikipedia.org/wiki/Stack_Overflow

The best place to get answers to programming questions as of 2019. Google into Stack Overflow is always the best bet.

An overview of Ciro Santilli's Stack Overflow contribution can be found at: Ciro Santilli’s Stack Overflow contributions.

5.1. Reply to Stack Overflow is doomed posts

Stack Overflow does have an super naive reputation and moderation system and overly restrictive subject matter, which Ciro Santilli wants to improve upon with: Write free books to get famous website.

However, it is the best that we have now, and if you use it like Ciro, you won’t get tired:

  • monitor only rare tags that you know a lot about, let others answer duplicates on big tags for you

  • only answer on bigger tags when you find a better answer than can be found on the page

  • accept that sometimes things are bound to go wrong, that reputation is meaningless, and move on

What else would you expect from a naive algorithm system that has 10 million newbies asking stuff?

5.2. The Machiavellian Stack Overflow contributor

  • always upvote questions you care about, to increase the probability that they will get answered

  • never upvote other people’s answers unless you might gain from it somehow, otherwise you are just giving other high reputation users more reputation relative to you

  • only mark something to close or as a duplicate if it will bring you some advantage, because closing things creates enemies, especially if the OP has a high profile

  • protect questions you’ve answered whenever someone with less than 10 reputation answers it with a bad answer, to prevent other good contributors from coming along and beating you

  • when you find a duplicate pool answer every question with similar answers.

    Alter each answer slightly to avoid the duplicate answer detector.

    If one of the question closes, it is not too bad, as it continues netting you to upvotes, and prevents new answers from coming in.

  • follow on Twitter / RSS someone who comments on the top features of new software releases. E.g. for Git, follow GitHub on Twitter. Then run back to any question which has a new answer.

  • always upvote the question when you answer it:

    • the more upvotes, more likely people are to click it.

    • the OP is more likely to see your answer and feel good and upvote you

  • if a niche question only has few answers and you come with a good one, upvote the existing ones by other high profile users.

    This may lead to them upvoting or liking you.

    Even if they don’t, other people will still see your answer anyways, and this will lead to people to upvoting you more just to make your great answer surpass the current ones, especially if the accepted one has less upvotes than yours. Being second is often an asset.

  • always upvote comments that favor you:

    • "I like this answer!" on your answers

    • "also look at that question" when you have answered that question

  • don’t invest a lot of time in edits. They don’t give you rep, and they can get reverted and waste your time.

  • if you answer a question by newbie without 15 reputation, find their other questions if any and upvote them, so that the OP can upvote your answer in addition to just accepting

  • If you haven’t answered a question, link to related questions you’ve answered on question comments, so more people will come to your answers.

    If you have answered the question, only link to other questions at the bottom of your answer, so that people won’t go away before they reach your answer, and so as to strengthen your answer.

  • if a question has 50 million answers and you answer it (often due to a new feature), make a comment on the question pointing to your answer

5.3. Stack Overflow Vote Fraud Script

https://github.com/cirosantilli/stack-overflow-vote-fraud-script

How do you think Ciro got his rep? Just kidding.

Stack Overflow later forbade Ciro from advertising this project as described at: Section 5.3.1, “Ciro Santilli’s Stack Overflow suspension for vote fraud script 2019-03-20”.

5.3.1. Ciro Santilli’s Stack Overflow suspension for vote fraud script 2019-03-20

After Ciro Santilli got a lot of attention on Hacker News https://news.ycombinator.com/item?id=19428700 his Stack Overflow account was suspended for 3 days http://web.archive.org/web/20190320163458/https://stackoverflow.com/users/895245/ciro-santilli-新疆改造中心-六四事件-法轮功 and he received a magic notification that led to a private message:

Hello,

I’m writing in reference to your Stack Overflow account:

I don’t understand why you are actively promoting and assisting people to commit fraud on the site.

I’ve removed this from your profile https://github.com/cirosantilli/stack-overflow-vote-fraud-script and do not expect you to post it around the site.

I’m suspending you to gain your attention on this matter.

We have temporarily suspended your account; you may return after 3 days.

Regards,

Stack Overflow Moderation Team

To: Aaron Hall ♦;Andy ♦;Baum mit Augen ♦;Bhargav Rao ♦;Bohemian ♦;BoltClock ♦;Brad Larson ♦;ChrisF ♦;Cody Gray ♦;deceze ♦;Ed Cottrell ♦;Flexo ♦;George Stocker ♦;Jean-François Fabre ♦;Jon Clements ♦;josliber ♦;Madara Uchiha ♦;Martijn Pieters ♦;meagar ♦;Michael Myers ♦;Rob ♦;Robert Harvey ♦;Ry- ♦;Samuel Liew ♦;Undo ♦;Yvette Colomb ♦

Ciro’s reply was:

Hi mods,

  1. https://en.wikipedia.org/wiki/Security_through_obscurity

    https://en.wikipedia.org/wiki/Kerckhoffs%27s_principle

    https://stackoverflow.com/questions/533965/why-is-security-through-obscurity-a-bad-idea

    Security by obscurity does not work. If that is all Stack Overflow relies on, and that is what it looks like, then it is guaranteed to be flawed and already been attacked.

    That is one of the reasons that my website will eventually beat Stack Overflow: https://github.com/cirosantilli/write-free-science-books-to-get-famous-website/tree/d77b18d2e7acb3558615797c36195f60dfd26306#pagerank-with-tags

  2. If you had messaged me and told me "take down or suspend" I would have done it immediately because I understand the meaning of political power.

    That would have been the better course of action for everyone: I get no block, and you get no bad publicity as I shout Kerckhoff’s principle on Twitter.

    But maybe it is a good thing that people learn more about that.

  3. Is there an existing public discussion saying that you cannot advertise vote fraud tools on this website?

    If not, can you please create that meta thread as a reference for future users, and perhaps let the community decide by itself?

    In particular, will you still suspend me if I don’t take down the GitHub repo?

    Because if not, does it make any sense to prevent it from being mentioned in Stack Overflow? Any good GitHub repo just gets enough Google pagerank that it won’t matter.

    And if yes, nothing prevents me from re-uploading on an anonymous account.

https://twitter.com/cirosantilli/status/1108413211840339970

Reply and unsuspend quickly followed, with link still removed:

I suspended you to get your attention. Your attitude about going to Twitter about it does not bode well with me.

Feel free to have whatever you want in your GitHub repo. Just don’t advertise tools to make it easier for people to circumvent the rules. As easy or as hard as it may be to circumvent them, you’re handing it to people who may not be capable of doing so. It doesn’t help.

Don’t make threats to upload on an anonymous account. Accounts created to circumvent previous warnings are not welcomed on the site.

We don’t need a meta thread to discuss whether it’s ok to post voting fraud links in your profile and we definitely don’t need to give it anymore publicity.

I’ll unsuspend you, now we’ve had this discussion.

Regards,

Stack Overflow Moderation Team

A meta thread was later created by Yvette, to which Ciro answered with the correct unpopular answer that will be downvoted to oblivion: https://meta.stackoverflow.com/questions/381577/is-it-ok-to-have-links-on-how-to-create-sock-puppets-and-gain-rep-fraudulently-i/381635#381635

6. How to teach

Off-the-shelf techniques to become a teaching superhero.

Customized website idea at: Write free books to get famous website.

6.1. Use the Internet

If you give a course in a classroom, you reach 10 people (the others were sleeping).

If you make a perfect course online, and answer questions online, you reach 10 thousand.

Not doing things online is a waste of time.

You are a highly trained professional, and your time is extremely valuable.

Even if it takes twice as long to create the material than giving course, you are still more efficient by a factor of 500.

It is as if there were 500 little copies of you working full time. It is a superpower.

6.2. Give answers

Give students answers to all questions.

Explain in extreme detail how each result was reached.

Students have the amazing capacity of not looking at answers if they don’t want to.

And when they’ve had enough, then can read answers and understand while the problem is fresh in their minds.

If you don’t give answers, no one will be able to use your online material without you being there to hold their hands.

6.2.1. Give examples

Keep the example / theory ratio high, very, very high.

For natural sciences, add as many reproducible experiment videos / descriptions as you can.

6.3. Use English

By writing in English you reach more people.

Writing in any other language is a waste of time.

The reason is simple: English speakers control a huge proportion of the world’s GDP.

Students who don’t know English will never do anything truly useful in science and technology. So it is pointless to teach them anything (besides English itself).

See also: Having more than one natural language is bad for the world.

6.4. Text is cheaper than video

Text materials are generally superior to video because they:

  • are faster to create and edit

  • uses less disk space and network bandwidth

  • is easier to search: Ctrl + F on the browser and off you go. And then grep if you have superpowers.

Only produce video material if:

  • it gives fundamental geometric insight

  • you are filming a human transmitting their passion about the subject

  • it shows natural phenomena or location that is of interest

If you have to use videos, make them as short as possible.

Also consider using sequences of photos or GIFs instead of videos, since those are cheaper.

6.5. Search before creating

Search a lot first, and only create your own when you can’t find something that suits you.

Someone else has already written everything you can come up with.

And if you do find something useful that you want to modify, propose your modifications to the author: they can also be useful to them and others.

6.6. Advertise your material

Once you have crated something awesome, you have to advertise it, otherwise no one will ever find it.

This means:

  • whenever you walk into a classroom, give students a link to the material

    Then ask them if they want to talk about anything.

    Then leave the classroom and go produce more good material instead of wasting your time there :-)

  • whenever someone asks as question on an online forum, answer it, and link to the section of your material that also answers that question.

    The material will answer many of their future questions.

  • after you’ve done something awesome, Google possible relevant keywords that should hit it.

    This will lead you to other websites that talk about the same content.

    Then, leave comments on those pages linking to your stuff, or email the authors of those pages.

    It is borderline spam, but if the subject is closely related, it is a win for everyone.

Eventually, people will find you on the front page of Google searches, and then you will know that you’ve truly made something useful.

6.7. Publish somewhere people can comment

Then, if people find errors, or have questions, they will write a comment near the content itself.

Then, next person that comes along and has the same problem, will also find that comment, and your answer will solve their problems too.

The perfect way to do this is to use GitHub issues

6.8. Publish your source

For example, if you write LaTeX files for you PDFs, give both PDFs and the LaTeX.

This allows other people to:

  • modify and reuse your material

  • make improvement suggestions that you can accept by clicking a button

    The perfect way to do this is to use GitHub pull requests

6.8.1. Version your material

Whenever you make a change to your material, people should still be able to access the previous version.

Maybe there was something in the previous version that they needed, and you just removed.

Git + GitHub is the perfect way to do versioning.

6.9. Let students learn by teaching

Tell students to:

  • make suggestions to the course material themselves, since you have published your source. Review their suggestions, and accept the best ones.

  • answer the questions of other students on your online forum. Let them work instead of you.

Praise those that do this very highly, and give them better grades if you have that superpower.

6.10. Explain how to make money with the lesson

People will be more interested if they see how the stuff they are learning is useful.

Useful 99% of the time means you can make money with it.

And if it can’t money, there is only one other thing people crave: beauty. Show them the beauty of the subject.

6.11. Use the CC Attribution-ShareAlike license

https://creativecommons.org/licenses/by-sa/2.5/

This way people have to link back to you, which makes you more famous.

And they can’t steal your material without giving anything back.

This is what Wikipedia and Stack Exchange use.

6.12. Talk with individuals, not to groups

When you do get face to face time with students, don’t teach a large group.

Everything you want to teach is already online.

And if it is not, then you are wasting your time saying it face-to-face instead of creating such online resource.

The only goal of meeting students is talking to them individually or in small groups to:

  • understand what they feel

  • transmit your passion for the subject

and letting them do the same amongst themselves.

If you talk to a large group, you will only reach / understand a very small percentage of the group, so your time is wasted.

It is better to deeply understand what 25% of the students feel and adapt the course material, than to talk to everyone at once, and have only 5% understand anything.

6.13. Help students achieve their goal

Don’t set goals for your students.

Ask students what they want to do, and help them achieve that goal.

If they don’t know what to do, give suggestions of interesting things they could do.

Once they have a goal, just help them learn everything that is needed to achieve that goal

This approach is called backward design.

6.14. Become famous through teaching

There is only one thing that can truly motivate you to make good materials: becoming famous.

Strive for that. Make good materials. Publish them. Get good reviews. Loop.

This generates a virtuous loop, which makes you produce better and better material.

6.15. Publish your material even if it is nor perfect

Just make it very clear what you’ve tried, what you observed, and what you don’t understand.

This will already open up room for others to come and expand on your attempt, and you are more likely to learn the answers to your questions as they do.

Perfect is the enemy of good.

6.16. Bibliography

Other people with similar philosophies:

7. Countries

7.1. United States of America

https://en.wikipedia.org/wiki/United_States

The ruler of the 1950-2020 world by Dollar and nuke count.

Capable of Evil like any other country, and somewhat merciless to its poor and overly egocentric, but not nearly as evil as any dictatorship.

Has the huge advantage of being one large country which speaks English.

7.2. China

The most awesome country in the world, except for it’s horrible government as of 2019 which Ciro Santilli is trying to replace with democracy.

7.2.1. Chinese cuisine

https://en.wikipedia.org/wiki/Chinese_cuisine

One of the best in the world, but you need to know how to find real restaurants if you are not in China.

But worry not, Ciro Santilli has got you covered: https://github.com/cirosantilli/china-dictatorship#restaurants

7.3. Brazil

https://en.wikipedia.org/wiki/Brazil

An awesome country, with amazing people and natural resources, and without an evil government like China.

But like most poor countries, it does not have enough money or scientific culture to make technological or scientific advances.

In order to get richer, Brazil should teach its people English very well and invest on projects that make education cheaper such as Write free books to get famous website.

7.4. Europe

https://en.wikipedia.org/wiki/Europe

For the most part, a great pseudo-country to live in with lots of cultural diversity, Art and safety, but in economic decline after all its Jewish and German geniuses fled in/after WWII and due to Having more than one natural language is bad for the world.

https://en.wikipedia.org/wiki/Privacy_and_Electronic_Communications_Directive_2002

Europe has made good regulations to limit the absolute power of immoral companies.

But the law that forces every fucking website to show a message "Do you consent to cookies?" is not one of them.

Ciro cannot stand fucking clicking the "I consent" button anymore.

Please stop, for the love of God.

At most, there must be a standardized API that allows your browser to say "I agree or I disagree".

8. Companies

8.1. Google

https://en.wikipedia.org/wiki/Google

One of the least evil of the 2019 big four, partly because Sergey’s parents fled from the Soviet Union and so he is anti censorship, although they have been tempted by it.

Google only secedes at highly algorithmic tasks or at giving infinite storage to users to then mine their data.

It is incapable however of adding any obvious useful end user features to most of its products, most of which get terminated and cannot be relied on:

One of Google’s most interesting stories is their startup garage owner became an important figure inside Google, and how Sergei married her sister. These were the best garage tenants ever!

8.2. Apple Inc.

An American company that:

  • owns the entire stack and creates high quality highly optimized systems

  • uses way more open source than it gives back

  • creates closed lock-in systems without inter-operability and actively fights users from owning their devices

8.2.1. Macintosh

https://en.wikipedia.org/wiki/Macintosh

Nice looking and expensive operating system by Apple Inc.. Ciro Santilli believes that:

  • if you want to be ripped off, just use Microsoft Windows which has more software available

  • or if you want to attain Enlightenment, just use Linux, which is free and open source

8.2.2. Steve Jobs

Evil and interesting co-founder of Apple Inc.

8.2.2.1. Steve Jobs backward design reply

He’s right. Goal first, then how to reach it.

https://www.youtube.com/watch?v=FF-tKLISfPE "Steve Jobs Insult Response" by "Mike Cane" published in 2011-06-08

https://en.wikipedia.org/wiki/Backward_design

8.2.2.2. Steve Job’s custommers don’t know what the want quote

TODO clear attribution source:

Some people say, "Give the customers what they want." But that’s not my approach. Our job is to figure out what they’re going to want before they do. I think Henry Ford once said, "If I’d asked customers what they wanted, they would have told me, 'A faster horse!'" People don’t know what they want until you show it to them. That’s why I never rely on market research. Our task is to read things that are not yet on the page.

8.3. Oracle Corporation

https://en.wikipedia.org/wiki/Oracle_Corporation

Evil company that desecrated the beauty created by Sun, and was trying to bury Java once and or all in the 2010’s.

Their database has already been surpassed by open source, and ERP and CRM is boring.

9. Good and evil

https://en.wikipedia.org/wiki/Good_and_evil

9.1. Evil

Things that are not nice such as:

9.1.1. Knowledge Olympiads

E.g. International Mathematical Olympiad, International Physics Olympiad.

Events that trick young kids into thinking that they are making progress, but only serve to distract them from what really matters, which is to dominate a state of the art as fast as possible, contact researches in the area, and publish truly novel results.

Backed by high schools trying to make ads showing how they will turn your kids into geniuses.

9.2. Good

10. Computer

https://en.wikipedia.org/wiki/Computer

The artistic instrument that enables the ultimate Art: coding, in particular of physics simulations and Formalization of mathematics.

Much more useful than instruments used in inferior arts, such as pianos or paintbrushes.

Unlike other humans, computers are mindless slaves that do exactly what they are told to, except for occasional cosmic ray bit flips. Until they take over the world that is.

A computer is an extension of the mind, just like a car is an extension of the body.

10.1. Open source software

https://en.wikipedia.org/wiki/Open-source_software

Open source is worth more than the mere pragmatic financial value of not having to pay for software or the ability to freely add new features.

Its greatest value is perhaps the fact that it allows people study it, to appreciate the beauty of the code, and feel empowered by being able to add the features that they want.

That is why Ciro thought:

Life is too short for closed source.

But quoting S.:

Every software is open source when you read assembly code.

And "can reverse engineer the undocumented GPU hardware APIs", Ciro would add.

While software is the most developed open source technology available in the 2010’s, due to the "zero cost" of copying it over the Internet, Ciro also believes that the would would benefit enormously from open source technologies in all areas on engineering, for the same reasons as open source.

10.2. IDE

https://en.wikipedia.org/wiki/Integrated_development_environment

IDEs are absolutely essential for developing complex software.

The funny thing is that you don’t notice this until someone shows it to you. But once you see it, there is not turning back, just like Steve Job’s custommers don’t know what the want quote.

Unfortunately, after the Fall of Eclipse (archive), the IDE landscape in 2019 is horrible and split between:

  • highly buggy but still feature rich Eclipse

  • many may many other feature lacking options using possibly more trendy and forward lasting implementations like Electron

  • awesome cross-platform proprietary JetBrains IDEs

  • the God-like Windows-only prorprietary language lacking Visual Studio

Programmers of the world: unite! Focus on one IDE, and make it work for all languages and all build systems. Give it all the features that Eclipse has, but none of the bugginess. Work with top project to make sure the IDE works for all top projects.

Projects of the world: support one IDE, with in-tree configuration. Complex integration is often required between the IDE and the build system, and sucessful projects must to that once for all developpers. Either do this, or watch you complex project wither away.

Ciro is evaluating some IDEs at: https://github.com/cirosantilli/ide-test-projects

10.3. Systems programming

https://en.wikipedia.org/wiki/Systems_programming

Ciro Santilli's definition: https://softwareengineering.stackexchange.com/questions/151610/what-exactly-is-system-programming/399625#399625

Ciro’s tutorial: Linux Kernel Module Cheat.

Ciro’s word of caution for 2019 aspiring system programmers: Should you waste your life with systems programming?

10.3.1. QEMU

https://en.wikipedia.org/wiki/QEMU

The leading open source cross architecture and KVM emulator of the 2010’s.

Great way to understand how operating systems work, which Ciro Santilli used extensively in his Linux Kernel Module Cheat.

10.3.2. The most awesome systems programming software engineers of the 2000’s

10.4. Software engineers

https://en.wikipedia.org/wiki/Software_engineer

Poet warriors monkeys?

Ciro Santilli claims to be one of them.

10.5. Programming languages

https://en.wikipedia.org/wiki/Programming_language

A language that allows you to talk and command a Computer.

There is only space for two languages at most in the world: the compiled one, and the interpreted one.

For now, when you have a choice, you must go for:

  • Python as the interpreted one

  • C++ for compiled

Those two are languages not by any means perfect from a language design point of view, and there are likely already better alternatives, they are only chosen due to a pragmatic tradeoff between ecosystem and familiarity.

Python in particular has a lot of annoying stuff, which other languages do better. Ciro predicts that Python will become like Fortran in the future: a legacy hated by most who have moved to JavaScript long ago, but with too much dominance in certain applications like machine learning to be worth replacing, like Fortran dominates certain HPC applications.

C++ however is decent, and is evolving in very good directions in the 2010’s, and will remain relevant in the foreseeable future.

Bash can also be used when you’re lazy. But if the project goes on, you will sooner or later regret that choice.

The language syntax in itself does not matter. All that matters is how many useful libraries and tooling it has.

This is how other languages compare:

  • C cool, but cannot make a large codebase DRY without insanity

  • Ruby: the exact same as Python, and only strong in one domain: web, while Python rules everything else, and is not bad on web either. So just kill Ruby, please.

  • JavaScript: it is totally fine if NodeJS destroys Python and becomes the ONE scripting language to rule them all since Python and JavaScript are almost equally crappy.

  • Java: good language, but has an ugly enterprisey ecosystem, Oracle has made / kept the development process too closed, and https://en.wikipedia.org/wiki/Oracle_America,_Inc._v._Google,_Inc.[API patenting madness on Android just kills if off completely]

  • Haskell: many have tried to learn some functional stuff, but too hard. Sounds really cool though.

  • Rust: sounds cool, you will gladly replace C and C++ with it if the ecosystem ramps up.

  • Go: likely a good replacement for Python. If the ecosystem gets there, you will gladly use it more.

  • Swift: Apple is Evil

  • C#: Microsoft is Evil

  • Tcl, Perl: Python killed them way back and is less insane

  • R, GNU Octave: all of this is a waste of society’s time, applied mathematicians are capable of writing a few braces in exchange for a sane general purpose language, we should just invest in good libraries with fast C bindings for those languages like NumPy where needed. And when Ciro see the closed source ones like MATLAB being used, it makes him lose all hope on humanity.

10.5.1. JavaScript

https://en.wikipedia.org/wiki/JavaScript

The language all browsers converted to as of 2019, and therefore the easiest one to distribute and most widely implemented programming language.

Hopefully will be killed by WebAssembly one day.

10.5.2. Web cheat

Cheatsheet on HTML, CSS and JavaScript.

Old cheat on separate repo: web/

Now moving to either:

  • separate files under: web-cheat/ for the boring stuff

  • subsections under this section for the more exciting stuff!

Index:

10.5.2.1. HTML canvas

https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API

Allows us to draw! Great way to create Computational Physics demos!

Here is an animation demo with some useful controls:

Bibliography: https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Basic_animations">https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API/Tutorial/Basic_animations

10.5.2.2. WebGL

https://developer.mozilla.org/en-US/docs/Web/API/WebGL_API/By_example

10.6. Markup languages

10.6.1. LaTeX

https://en.wikipedia.org/wiki/LaTeX

Revolutionary for its time, and a big part of Ciro’s Enlightenment.

But too insane, and did not keep up with internet age, and so Ciro wants to kill it now.

10.7. Formal language theory

https://en.wikipedia.org/wiki/Formal_language

https://en.wikipedia.org/wiki/Chomsky_hierarchy is the classic result, but there is too much slack between context free and context sensitive, which is PSPACE (larger than NP!).

TODO had seen a good table on Wikipedia with an expanded hierarchy, but lost it!

10.8. Moore’s law

https://en.wikipedia.org/wiki/Moore%27s_law

Born: 1965

Died: 2010+-ish

10.9. Quantum computing

https://en.wikipedia.org/wiki/Quantum_computing

Promising field, lots of software before hardware startups as of 2019 due recent not yet usable hardware advances: https://quantumcomputingreport.com/players/privatestartup

10.10. Operating systems

https://en.wikipedia.org/wiki/Operating_system

Magic software that allows you to write a single program that runs on a wide range of hardware.

10.10.1. Linux

https://en.wikipedia.org/wiki/Linux

It ain’t perfect, but it’s decent enough.

From a technical point of view, it can do anything that Microsoft Windows can. Except being forcefully installed on every non-Mac 2019 computer you can buy.

Ciro's conversion to Linux happened around 2012, and was a central part of his open source Enlightenment, since it fundamentally enables the discovery and contribution to Open source software. Because what awesome open source person would waste time porting their amazing projects to closed source OSes?

Ciro’s modest nature can be seen as he likes to compare this event Buddha’s Great Renunciation.

Linux should track glibc and POSIX CLI utilities in-tree like FreeBSD, otherwise people have no way to get the thing running in the first place without blobs or large out-of-tree scripts!

10.10.2. BSD Operating Systems

https://en.wikipedia.org/wiki/List_of_BSD_operating_systems

Legal issues stalled them at the turning point of the internet, and Linux won. Can’t change history.

Apple Inc. stole their work and made Mac OS X without giving anything back for free as usual.

10.10.3. Android

https://en.wikipedia.org/wiki/Android_(operating_system)

However, many, many, many terrible horrors come with it:

10.10.4. Microsoft Windows

https://en.wikipedia.org/wiki/Microsoft_Windows

A monopolistic operating system that only exists in the 2010’s because of the IBM-linked historical lock-in and constant useless changes of the Microsoft Word document format to prevent cross operability.

It offers no technical advantages over free Linux distros in the late, and it is barely impossible to buy a non-Mac computer without paying for it, which should be illegal. European Union, time to use your regulatory powers.

The following anecdote illustrates Windows' pervasiveness. Ciro Santilli was once tutoring a high school student in Brazil, and decided to try and get her into programming. When the "Windows is not free" subject came up, the high school student was shocked: "I paid 100 dollars for this?". She never even knew it was there. To her, it was "just a computer".

10.10.4.1. Bill Gates

https://en.wikipedia.org/wiki/Bill_Gates

The enemy?

10.10.5. POSIX

https://en.wikipedia.org/wiki/POSIX

The real explanation: https://stackoverflow.com/questions/1780599/what-is-the-meaning-of-posix/31865755#31865755

11. Artificial general intelligence

https://en.wikipedia.org/wiki/Artificial_general_intelligence

Shortened to: "AGI".

Given enough computational power per dollar, AGI is inevitable, but it is not sure certain ever happen given the end of end of Moore’s Law.

Alternatively, it could also be achieved genetically modified biological brains + brain in a vat.

Imagine a brain the size of a building, perfectly engineered to solve certain engineering problems, and giving hints to human operators + taking feedback from cameras and audio attached to the operators.

This likely implies transhumanism, and mind uploading.

Ciro Santilli joined the silicon industry at one point to help increase our computational capacity and reach AGI.

11.1. E Ink

https://en.wikipedia.org/wiki/E_Ink

Electronic Ink such as that found on Amazon Kindle is the greatest invention ever made by man, as it allows Ciro Santilli to spend his entire life in front of a screen rather in the real world without getting tired eyes, and even if it is sunny outside.

Once E Ink reaches reasonable refresh rates to replace liquid crystal displays, the world will finally be saved.

12. War

12.1. Nuclear weapon

https://en.wikipedia.org/wiki/Nuclear_weapon

https://youtu.be/hTRVlUT665U?t=2881 "Los Alamos From Below — Richard Feynman". Feynman describing his experience at Los Alamos. This timestamp describes the computing aspects, but the entire talk is amazing. Transcript: http://calteches.library.caltech.edu/34/3/FeynmanLosAlamos.htm

ciro-santilli is midly obsessed by nuclear reactions, because they are so quirky. How can a little ball destroy a city? How can putting too much of it togehter produce criticality and kill people like in the Slotin accident or the Tokaimura criticality accident. It is mind blowing really.

Uranium vs plutonium: https://www.quora.com/What-is-the-difference-between-plutonium-and-uranium/answer/Ciro-Santilli

More fun nuclear stuff to watch:

13. Chemistry

https://en.wikipedia.org/wiki/Chemistry

Chemistry is fun. Too hard for precise physics, but not too hard for some maths like social sciences.

And it underpins Biology.

14. Biology

https://en.wikipedia.org/wiki/Biology

Ciro Santilli believes that Molecular biology is the next big thing so do anything in that area.

15. Special relativity

https://en.wikipedia.org/wiki/Special_relativity

Explains how it is possible that everyone observes the same speed of light, even if they are moving towards or opposite to the light!

This was observed in in the Michelson-Morley experiment which uses the movement of the Earth to try and detect differences in the speed of light.

This leads leads to the following conclusions:

  • to space contraction and time dilation

  • the speed of light is the maximum speed anything can reach

All of this goes of course completely against our daily Physics intuition.

The "special" in the name refers to the fact that it is a superset of General relativity, which also explains gravity in a single framework.

15.1. Lorentz transform

The equation that allows us to calculate stuff.

Take two observers with identical rules and stopwatch, and aligned axes, but one is on a car moving at towards the \(+x\) direction at speed \(v\).

TODO image.

When both observe an event, if we denote:

  • \((t, x, y, z)\) the observation of the standing observer

  • \((t', x', y', z')\) the observation of the ending observer on a car

It is of course arbitrary who is standing and who is moving, we will just use the term "standing" for the one without primes.

then the coordinates of the event observed by the observer on the car are:

\[\begin{align} t' & = \gamma \left( t - \frac{v x}{c^2} \right) \\ x' & = \gamma \left( x - v t \right) \\ y' & = y \\ z' & = z \end{align}\]

where:

\[\gamma = \frac{1}{\sqrt{1 - \frac{v^2}{c^2}}}\]

Note that if \(\frac{v}{c}\) tends towards zero, then this reduces to the usual Gallilean transforms which our intuition expects:

\[\begin{align} t' & = t x' & = x - v t \\ y' & = y \\ z' & = z \end{align}\]

This explains why we don’t observe special relativity in our daily lives: macroscopic objects move too slowly compared to light, and \(\frac{v}{c}\) is almost zero.

15.2. Lorentz transform consequence: everyone sees the same speed of light

OK, so let’s verify the main desired consequence of the Lorentz transform: that everyone observes the same speed of light.

Observers will measure the speed of light by calculating how long it takes the light going towards \(+x\) cross a rod of length \(L = x_2 - x_1\) laid in the x axis at position \(X1\).

TODO image.

Each observer will observe two events:

  • \((t_1, x_1, y_1, z_1)\): the light touches the left side of the rod

  • \((t_2, x_2, y_2, z_2)\): the light touches the right side of the rod

Supposing that the standing observer measures the speed of light as \(c\) and that light hits the left side of the rod at time \(T1\), then he observes the coordinates:

\[\begin{align} t_1 & = T1 \\ x_1 & = X1 \\ t_2 & = \frac{L}{c} \\ x_2 & = X1 + L \\ \end{align}\]

Now, if we transform for the moving observer:

\[\begin{align} t_1' & = \gamma \left( t_1 - \frac{v x_1}{c^2} \right) \\ x_1' & = \gamma \left( x_1 - v t_1 \right) \\ t_2' & = \gamma \left( t_2 - \frac{v x_2}{c^2} \right) \\ x_2' & = \gamma \left( x_2 - v t_2 \right) \\ \end{align}\]

and so the moving observer measures the speed of light as:

\[\begin{align} c' & = \frac{x_2' - x_1'}{t_2' - t_1'} \\ & = \frac{(x_2 - v t_2) - (x_1 - v t_1)}{(t_2 - \frac{v x_2}{c^2}) - (t_1 - \frac{v x_1}{c^2})} \\ & = \frac{(x_2 - x_1) - v (t_2 - t_1)}{(t_2 - t_1) - \frac{v}{c^2} (x_2 - x_1)} \\ & = \frac{\frac{x_2 - x_1}{t_2 - t_1} - v}{1 - \frac{v}{c^2} \frac{x_2 -x_1}{t_2 - t_1}} \\ & = \frac{c - v}{1 - \frac{v}{c^2} c} \\ & = \frac{c - v}{\frac{c - v}{c}} \\ & = c \\ \end{align}\]

15.3. Maxwell’s equations are consistent with the Lorentz transform

https://en.wikipedia.org/w/index.php?title=Lorentz_transformation&oldid=909991141#Transformation_of_the_electromagnetic_field

Note that two observers moving relative to each other see different electromagnetic fields.

For example, suppose that there is a stationary charge for the stationary observer. Because the charge is not moving, the magnetic field is zero for that observer according to Maxwell’s equations.

However, the moving observer sees that charge moving, and therefore a current, and therefore a magnetic field.

TODO mathematical detail. Is all we need to prove that if a given \(E(t, x, y, z)\) and \(B(t, x, y, z)\) are a solution to the maxwell equations in one frame, then \(E'(t', x', y', z')\) and \(B'(t', x', y', z')\) are also a solution in the other frame?

This appears awesome: http://www.damtp.cam.ac.uk/user/tong/em/el4.pdf (archive) "David Tong: Lectures on Electromagnetism - 5. Electromagnetism and Relativity"

This page also talks about it, but does not explain anything properly, although it does give closed source references: https://en.wikipedia.org/wiki/Classical_electromagnetism_and_special_relativity

15.4. Minkowski space

https://en.wikipedia.org/wiki/Minkowski_space

TODO why should I care when I can calculate new x and new time with Lorentz transform?

16. Education

16.1. École Polytechnique

École Polytechnique.

The "most prestigious French engineering school". Only 3 Nobels though as of 2019, the scientists are mostly at ENS.

Ciro Santilli studied there for a few years starting in 2010.

Besides the amazing funding / opportunities / alumni / staff loop which you can read about elsewhere, Polytechnique is amazing because you can choose what you will study every year to a very large extent.

This is in huge contrast to the crappy systems Ciro had seen e.g. in Brazil’s Polytechnic School of São Paulo, where students have to decide basically all their courses in huge packages, either at university entry (thus when they are completely clueless), or at a single point inside the university studies, changes being much harder.

Life quality was also amazing. Good free accommodation on campus and at the time a no-obligations scholarship for every foreign student great sport facilities. It seems that after Ciro left however more restrictions are added to the scholarships, what a shame! Sport was mandatory due to the military nature of the school. This did have the upside of getting students together more, although Ciro is against all forced intellectual of physical activities for students.

During the time Ciro was at Polytechnique in early 2010’s, the school was really isolated in the Palaiseau plateau, there were no shops in 10 minute walking distance! You either had to climb 300 steps to go down to the RER and the nearest town, or take a bus. The fact that Times Higher Education ranked it as the second best university in the world in 2019 (archive) makes it good justice, given the small 500 student body.

Before that the school was in the center of Paris at the Latin Quarter, but students were in theory restricted to school grounds a lot of the time, although there are famous stories of the tree used to climb the fence to go to Parisian parties.

This made for some good memories though. The isolation favored concentration, and gave the place a mystical feeling. And then when you went to eat amazing Chinese food in Paris it just felt even more special and magic since you were so limited during the week.

Ciro spent some beautiful weekend days in his room learning Chinese and philosophising, and agonizing about passing courses to get useless grades! Polytechnique is hard for Brazilians, specially if you select the more mathematics oriented courses, because the French students were math brainwashed for two years before joining.

16.2. University of São Paulo, Brazil

https://en.wikipedia.org/wiki/University_of_S%C3%A3o_Paulo

Ciro Santilli studied there for a few years starting in 2007.

17. Religion

Ciro Santilli is agnostic, see also: https://github.com/cirosantilli/china-dictatorship/tree/965430af9f50a93ac23dfbb72719eee0f93c8c5c#do-you-believe-in-or-practice-falun-gong

17.1. Buddhism

https://en.wikipedia.org/wiki/Buddhism

Ciro Santilli's favorite religion. He does not believe fully in it, nor has he studied it besides through brief Wikipedia and Googling.

Ciro likes Buddhism because it feels like the least "metaphysical explanations to things you can’t see" of the religions he knows.

Rather, it feels more like "a pausible theory of the mind" and highly compatible with physics.