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??".
After Ciro's colleague was doing that in a project:
On the theory vs practice of computer science:
Whereas Turing completeness is enough for mathematicians, humans need "run-on-Debian-complete".
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.
On how you make the best friends in life when dealing with hardships together.
The bond between men is like the bond between two metals: it is better made under fire.
In Ciro's case, this in particular means going through high school/universities studies and work projects, though of course war would apply particularly well. Perhaps inspired by as iron sharpens iron, so one person sharpens another.
This is of course just another version of one picture is worth a thousand words.
Animal rights by Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli has mixed feelings about animal rights.
On one hand, his irrational side wants of course all animals to be happy.
On the other, he does not care about this enough to not kill and eat them, even though he believes that you could live off plants relatively well.
His more rational side says: humans are sacred. Either because you believe in the soul, or because your built-in empathy behaviours. If it is not a human, do whatever you want to it. Killing is already undoubtedly the greatest sin. It is not OK to kill a human painlessly is it? So if torturing it brings humans good, then do it.
Of course, this does get use close and closer to "the what is a human" question, which is more relevant than ever in the awakening of genetics: all species are after all a continuum right?
And Ciro does not have a simple solution to this problem, besides that in 99.9999% the answer is obvious to 99.9999% of the people, and for the others cases, we have to do it like the law and make flawed rules to cover the remaining 0.000099999% cases and let juries decide the rest.
The only other sensible sacredness barrier is the common vegetarian "nervous systems are sacred" one. But how can you believe that if you also follow the religion of physics, where everything is just made of atoms?
Is it evil to take one neuron and torture it? What does that even mean? It will be fun when pain and pleasure are fully understood.
Laws in most 2020 Western modern societies have converged to a hypocritical balance between not offending people too much by hiding the killing and minimizing the pain when possible at low cost. Killing animals painlessly is basically always fine if it brings any "non sadistic" pleasure to humans. And torturing animals is fine with approval e.g. to make medicines.
This has the downside of increasing costs for society. Maybe there are practical benefits besides people feeling bad about animals? Maybe we would have more serial killers if people were free to torture animals? Maybe people in butcher shops would become depressive if their bosses weren't forced to use more expensive painless killing methods? Neither of those seems like huge arguments though.
It eventually comes down to: "how much more is a human life worth than that of an animal" which brings Jesus's Matthew 6:25-34 "Do Not Worry" (archive) quote to mind:
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?
Non-vegetarian pets owners also baffle Ciro, as most of them basically extend the sacred human line further arbitrarily to certain other cute looking animals like dogs, cats or rabbits, but will gladly kill a cow indirectly by paying someone to pay someone to pay someone to cut it into small pieces. Or they believe that certain specific individuals are sacred. Admittedly, the latter is more rational, and looks a lot of how we treat our own families well, and can accept that other families are not doing so well.
Ciro's even more rational evil side says: the real reason why humans are sacred is a practical one: people have families that love them, and they come to kill you if you kill them, and this starts endless chains of violence that make society unbearable.
While animals feel pain when their children are killed, their memory and logic is just not good enough to fully understand that humans in general have an evil plot to it, and they don't have a method to communicate between themselves and fight back.
For similar reasons, Ciro is pro-abortion.
Ciro should stop discussing topics in which infinite argument has already been had. Sometimes he writes things down so he can stop caring the next time the subject comes up, as there's no need to say it again once it is written.
Ciro Santilli is against affirmative action university entry quotas that reserve spaces e.g. for students from discriminated races or poor families. Instead, he believes that affirmative action should take place on earlier stages of education as described at: free gifted education.
Notably, Brazil has implemented a very heavy university entry quota system after Ciro had left university there: www.bbc.co.uk/news/business-23862676
This is of course easy for a white male from a privileged background to say, and infinite debate has already been had on this matter, but here goes again.
First, in defense to the personal attack, Ciro raises the fact that he has dedicated large chunks (all?) of his life to open source software and knowledge in general, which Ciro believes is the only way to actually make the world fairer to poor countries. His money (time) is where his mouth is.
One good argument in favor of the Brazilian quota system, is that the kids who enter university because of quotas do just as well as those who don't.
Ciro has actually believes that this is possible, and offers the following possible explanation: most of pre-university knowledge is useless, and university selection system is crap, and Ciro wants to destroy it with a system in which anyone can learn university stuff from home.
Both the top end of the quota and non-quota kids are basically equally capable of doing useful stuff therefore.
Only a tiny fraction of what you learn in high school is useful for university or your career.
And possibly more importantly than knowledge, Ciro saw many of his colleagues (basically all of which were from relatively privileged backgrounds) "do badly" in university, because of lack of motivation, because they had chosen a course only to find that they were not interested in it because the existing high school educational system is crap and does not help them find what they love and because it costs you several years of your life to change your choice in most universities (long live École Polytechnique).
Maybe the fact that poor kids know that they are fucked if they fail, and so they have to succeed at any cost, might also help with motivation. Which is a terrible terrible thing, because only those who have to leeway to take risks end up taking them and making the the next big thing.
Ciro believes instead that only once kids have learnt university level stuff in their area of interest for free on the Internet should they go through selection based on that specific and much more concentrated useful knowledge.
And this competition must only be used to distribute resources which you can't learn from fucking computers:
Once this point knowledge is reached however, it starts to become unclear if a single "everyone takes the same test to avoid discrimination" test is feasible anymore, and we start entering the much more relevant (and potentially discriminatory) "I am a teacher trying to advance the state of the art, and I need a person mildly skilled in the art to do some slave labor for me", which is PhDs selection work.
If quota are in place, what will happen is that parents of the rich kids will start investing less in education, and possibly just put their kids in high schools, and do home schooling instead. This would therefore reduce the total investments the country makes in education!
Outside of the obvious technical evolution proposed, Ciro is a huge proponent of free gifted education. Or closely related, creating scholarships that focus on poor students. The entry requirements should be the same, but once you qualify, everyone should have enough money to lead a decent life during their studies.
Then let those kids pass exactly the same university entry exams, and watch them crush the average privileged kids.
This advice is similar to what is mentioned at: what poor countries have to do to get richer. When you don't have money to do everything, you must select a few good bets and focus on them. You can't pay a lot to every public school teacher, so you must select a few select places that need it the most. As those smart bets pay off, you start to have more and more money to expand the system further.
Video 1.
Inside Westside Barbell by Vice News (2018)
Source.
One sentence of this nice documentary about the notorious Westside Barbell gym where the openly pro-performance-enhancing-drug powerlifting legend leader and cult-leader-like personality Louis Simmons teaches just stuck to Ciro Santilli's mind. His top tenant and manager Tom Barry talks about Louis:
The man [Louis] lives in his own world, and he just rejects everything outside of it, it doesn't matter. Like: "what's your name"? He doesn't care. If you lift numbers, he cares about that, that's more important.
Ciro admires this level of focus, directness and meritocracy. Just don't take drugs, children. Louis' creation of a cult-like training atmosphere is another interesting aspect, see also: Section "Group students by interest, not by age".
Ciro wonders if Louis is a white supremacist though, this was asked here but is inconclusive. But being composed almost exclusively of a bunch of white bald ex-prisoners in the US makes it a bit suspicious. Racism is bad BTW.
This is one of the main reasons why Ciro Santilli invested in OurBigBook.com.
Ciro believes that the only thing students must be forced to learn is to speak read and write English and that a teacher's main job after that is to help students find their next big goals and also ties into the backward design philosophy.
Everything else, the student must choose.
This idea is generally known as self-directed learning.
This is most notable in University entry examinations of poor countries, where students often have to waste one extra year of their lives to go through preparation for the useless university entry exams. And then, surprise surprise, if they actually get in, they find that this is not what they really wanted to do, and they just go through to the end miserably because they understandably they don't want to risk another year of their lives.
Ciro saw this first hand École Polytechnique which was way freer than his university in Brazil.
Video 1.
The Purpose of Education by Noam Chomsky (2012)
Source.
  • 0:00 discusses Education as a system of indoctrination: indoctrination for people to comply with the Establishment and pass tests, vs the Age of Enlightenment in which education should help you achieve your own intellectual/life goals. He suggests without specific evidence that after the 60's there was explicit intervention in the US to increase the indoctrination aspect, of which debt is a part.
  • 15.45: assessment vs autonomy: exams are useless, except as a tool to help improve teaching and self assess. Tells anecdote about little girl who wanted to learn more about a subject, asked teacher how to learn more, teacher said you can't, you have to study for this useless national exam instead which will determine your future, and if I'm rehired or not.
Godfrey Hounsfield, 1979 Nobel Prize in Physiology and Medicine:[ref]
They tried hard to educate me but I responded only to physics and mathematics
Since Ciro Santilli is Brazilian, this is understandably a common conversation opener.
And rightly so, since soccer in particular is truly ridiculously popular in Brazil, where "what is your local soccer team?" is just as valid a conversation starter as "Which city are you from?".
So here goes Ciro's 2020 cynic answer:
I currently root actively against Brazil.
The ironic reason is simple: maybe is Brazil loses more on this useless art, then maybe people will get tired of it, and instead invest on more useful and beautiful arts.
Notably, what Ciro really wants people to root for are:
Don't get Ciro wrong.
Observing professionals who do it amazingly can be beautiful.
But why the F do you have to root for a team unless your wife or children are playing in it (and even then..., how will that help?)?
What will you get from that?
Even if it is your national team, why does it matter if they win or lose?
Hooliganism just takes that uselessness to a hole new level.
Now some confessions.
A five year old Ciro will never forget when the feeling of Brazil won the 1994 World Cup on the penalties and everyone went mad that evening.
A nine year old Ciro stopped watching the 1998 World Cup Final of Brazil vs France half way during the 3-0 massacre and went to his front garden to kick his soccer ball on the metallic fence gate which represented a goal.
After that, Ciro went through puberty he guesses, and noticed that the natural sciences are just cooler than this soccer watching bullshit.
Video 3.
Rooting for sports is for suckers by Lit Nomad
. Source.
Companies are getting too much power to distort regulations and destroy privacy.
Taxes pay for the physical car roads, so why shouldn't they also pay for the "online roads" of today?
Other less simple ones that might also be feasible:
All of them should have strong privacy enabled by default: end-to-end encryption, logless, etc. Governments are not going to like this part.
And then if you ever forget a password or lose a multi-factor authentication token, you can just go to an ID center with your ID to recover it.
Ciro Santilli is a big believer that there is value in tutorials written by beginners, because beginners are more likely to explain things in a way that other beginners can understand.
Even though they make more mistakes, this more approachable point of view can be very valuable.
And mistakes/omissions can be corrected on comments by people with more knowledge, so that the writer also ends up learning something new.
By other people:
  • jakobschwichtenberg.com/about/ from Jakob Schwichtenberg mentions quotes C. S. Lewis book "Reflections on the Psalms"[ref]:
    It often happens that two schoolboys can solve difficulties in their work for one another better than the master can. [...] The fellow-pupil can help more than the master because he knows less. The difficulty we want him to explain is one he has recently met. The expert met it so long ago he has forgotten. He sees the whole subject, by now, in a different light that he cannot conceive what is really troubling the pupil; he sees a dozen other difficulties which ought to be troubling him but aren't.
Cirocoin by Ciro Santilli 40 Updated 2025-07-16
Good pious Cirists earn Cirocoins.
Cirocoins are the most valuable form of currency that exists at any point.
Cirocoins can only be issued by Ciro Santilli.
Cirocoins are strictly nominal, and cannot be traded by recipients with anyone but Ciro, i.e. they are extremely illiquid.
Cirocoins can be removed from recipients at any point if they commit non-Cirist acts.
It is not possible to give a precise number to how many Cirocoins anyone owns. This is decided on a transaction by transaction basis. Ciro can therefore only inform you if your Cirocoin balance increased or decreased, but any attached number has no value, and thus are equivalent to expressions of type "you gained/lost a Cirocoin".
The following inferior currencies come to mind:
Limit (mathematics) by Ciro Santilli 40 Updated 2025-07-16
The fundamental concept of calculus!
The reason why the epsilon delta definition is so venerated is that it fits directly into well known methods of the formalization of mathematics, making the notion completely precise.
Derivative by Ciro Santilli 40 Updated 2025-07-16
The derivative of a function gives its slope at a point.
More precisely, it give sthe inclination of a tangent line that passes through that point.
Measure theory by Ciro Santilli 40 Updated 2025-07-16
Main motivation: Lebesgue integral.
The key idea, is that we can't define a measure for the power set of R. Rather, we must select a large measurable subset, and the Borel sigma algebra is a good choice that matches intuitions.
Fourier series by Ciro Santilli 40 Updated 2025-07-16
Approximates an original function by sines. If the function is "well behaved enough", the approximation is to arbitrary precision.
Fourier's original motivation, and a key application, is solving partial differential equations with the Fourier series.
The Fourier series behaves really nicely in , where it always exists and converges pointwise to the function: Carleson's theorem.
Video 1.
But what is a Fourier series? by 3Blue1Brown (2019)
Source. Amazing 2D visualization of the decomposition of complex functions.
Topology by Ciro Santilli 40 Updated 2025-07-16
Just by havin the notion of neighbourhood, concepts such as limit and continuity can be defined without the need to specify a precise numerical value to the distance between two points with a metric.
As an example. consider the orthogonal group, which is also naturally a topological space. That group does not usually have a notion of distance defined for it by default. However, we can still talk about certain properties of it, e.g. that the orthogonal group is compact, and that the orthogonal group has two connected components.
Generalize function to allow adding some useful things which people wanted to be classical functions but which are not,
It therefore requires you to redefine and reprove all of calculus.
For this reason, most people are tempted to assume that all the hand wavy intuitive arguments undergrad teachers give are true and just move on with life. And they generally are.
One notable example where distributions pop up are the eigenvectors of the position operator in quantum mechanics, which are given by Dirac delta functions, which is most commonly rigorously defined in terms of distribution.
Distributions are also defined in a way that allows you to do calculus on them. Notably, you can define a derivative, and the derivative of the Heaviside step function is the Dirac delta function.
Complex analysis by Ciro Santilli 40 Updated 2025-07-16
The surprising thing is that a bunch of results are simpler in complex analysis!

Pinned article: Introduction to the OurBigBook Project

Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
We have two killer features:
  1. topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculus
    Articles of different users are sorted by upvote within each article page. This feature is a bit like:
    • a Wikipedia where each user can have their own version of each article
    • a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
    This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
    Figure 1.
    Screenshot of the "Derivative" topic page
    . View it live at: ourbigbook.com/go/topic/derivative
  2. local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:
    This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
    Figure 5. . You can also edit articles on the Web editor without installing anything locally.
    Video 3.
    Edit locally and publish demo
    . Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    Descendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact