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Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Accounts controlled by Ciro Santilli by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Ciro Santilli controls the following accounts.

With non-trivial activity:

github.com/cirosantilli on GitHub
stackoverflow.com/users/895245 on Stack Overflow
www.linkedin.com/in/cirosantilli on LinkedIn
www.youtube.com/c/CiroSantilli on YouTube
Twitter: see Section "Ciro Santilli's Twitter accounts"
archive.org/details/@cirosantilli2 on the Internet Archive. Was archive.org/details/@cirosantilli but got deleted due to an "admin error" and the old username cannot be restored!^[ref]
en.wikipedia.org/wiki/User:Cirosantilli2 and commons.wikimedia.org/wiki/User:Cirosantilli2: Ciro tries to upload all educational CC content he creates to Wikimedia Commons as an extra backup and sometimes to use in Wikipedia pages
www.facebook.com/cirosantilli/ Ciro accepts all friend requests there, but expect a few non-technical posts. Unless you look like a massive honeypot account, please send context in advance in that case.
www.quora.com/profile/Ciro-Santilli
www.reddit.com/user/cirosantilli/ is Ciro's Reddit account, mostly computer and China topics
maps.app.goo.gl/npV35XTppSBTmNqC8: Google Maps. Ciro Santilli likes to make additions to certain niche topics that are missing, having reached Local Guide Level 6 as of 2024. He can't do as much as he'd like so as to not reveal his current city however.

Trivial or no activity:

Profiles without URLs (OMG...):

Discord: username cirosantilli, previously cirosantilli#8921

Accounts in Chinese websites. These accounts might be banned or altered or offer other limitations, so Ciro only communicates briefly through them. All communication through those channels should obviously be assumed to be compromised:

bbs.nibaedu.com/index.php?m=space&uid=70
www.renren.com/338003848/profile
www.tianya.cn/109285544 (can't post, no cell phone)
hacpai.com/member/cirosantilli unable to login as of 2019-10-12, reason unclear, either ban or website too crappy.
pincong.rocks/people/cirosantilli Lost account tested as of 2022-11 and likely much earlier. Last existing password not working, and there doesn't seem to be a reset password button. Creating cirosantilli2
pincong.rocks/people/cirosantilli2
tieba.baidu.com/home/main?id=5cd56369726f73616e74696c6c69c944
v2ex.com/member/cirosantilli: Ciro was blocked and or account deleted on 2020-07-23: cirosantilli.com/china-dictatorship/v2ex
- v2ex.com/member/cirosantilli2: was created by someone else most likely and cannot be re-registered. Also blocked.
- v2ex.com/member/cirosantilli3: Ciro created this new account November 2023, let's see how long it lasts.
www.zhihu.com/people/cirosantilli. Ciro was prevented from posting in 2018-06-25, and the account and all content mentioning him were taken down in 2019-11-03.
www.weibo.com/p/1005055601627311: started requiring a cell phone to login in 2020, and Ciro didn't want to give his cell phone number to the CCP and didn't have the patience to manage a secondary phone number, so he is not logging in for now. The account was blocked in 2021: cirosantilli.com/china-dictatorship/ciro-santillis-weibo-block

Accounts in Russian websites:

vk.com/id595305194

Dead websites:

www.citeulike.org/user/cirosantilli (2019-05)

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Pleistocene by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Agriculture is not the official definition of the age. But it is good enough. Likely related to the official end of glaciations thing.

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Ciro Santilli's Twitter accounts by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Accounts controlled by Ciro Santilli on Twitter:

twitter.com/cirosantilli primary channel, contains only updates on Ciro's best technical content. Low volume.
twitter.com/cirosantilli2 secondary channel, contains smaller technical updates that didn't make it to the primary channel, and some China fun. Higher volume.

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Poincaré conjecture by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Pre-order depth-first search by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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This is the order in which you would want to transverse to read the chapters of a book.

Like breadth-first search, this also has the property of visiting parents before any children.

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Primality test by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Prime number by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Print only the matching group in Perl by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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stackoverflow.com/questions/5617314/perl-regex-print-the-matched-value/5617355#5617355

perl -lne 'print for /mykey=(\d+)/'

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Privacy coin legality by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Privacy focused email provider by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Eon by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Poincaré group by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Full set of all possible special relativity symmetries:

In simple and concrete terms. Suppose you observe N particles following different trajectories in Spacetime.

There are two observers traveling at constant speed relative to each other, and so they see different trajectories for those particles:

space and time shifts, because their space origin and time origin (time they consider 0, i.e. when they started their timers) are not synchronized. This can be modelled with a 4-vector addition.
their space axes are rotated relative to one another. This can be modelled with a 4x4 matrix multiplication.
and they are moving relative to each other, which leads to the usual spacetime interactions of special relativity. Also modelled with a 4x4 matrix multiplication.

Note that the first two types of transformation are exactly the non-relativistic Galilean transformations.

The Poincare group is the set of all matrices such that such a relationship like this exists between two frames of reference.

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Evil by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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Things that are not nice such as:

Taboola, Outbrain, and other chumbox
BLOBs
Europe cookie law
adhesive inside mobile phones and more generally, planned obsolescence
Jupyter Notebook
typographical characters that look like ASCII ones, but are not the ASCII ones, e.g. typographical quotes, em-dash. The non-breaking hyphen is not even whitespace, and by def Why not stick to ASCII when ASCII is good enough?
excessive encapsulation
replacement of master and slave terminology from technology
mailing lists. And to add insult to injury, HTML on mailing list messages instead of plaintext.
blank lines in code added by people trying to increase clarity, especially when there is already indentation for that. Every blank line must be preceded by a line comment explaining what the following block is about, or removed.
messaging software that force you to have a mobile phone
advertisements by telephone/SMS
"state" such as global variables and object members, long live functional programming?
mosquitoes, the only intrinsically bad thing about tropical countries
projects with slow compilation times
Microsoft Windows
the 2019 Chinese government
e-learning websites that only allows verified teachers to write content. Cowards who can't handle ranking algorithms.
domain-specific language
a build system without an out-of-tree option
non-linear Git history: stackoverflow.com/questions/20348629/what-are-advantages-of-keeping-linear-history-in-git
visual programming languages like Scratch. Waste of time. Text programming languages are already equally as visual due to indentation:
```
if x == 0:
    x = 1
```
Just make good serious gamedev libraries and integrated development environments for those real languages instead.
software that prevents you from running as root. Let me fucking shoot myself in the foot if I want to. It is better than having to deal with your hand holding bullshit, which is done in a different way for every project. E.g.: stackoverflow.com/questions/17466017/how-to-solve-you-must-not-be-root-to-run-crosstool-ng-when-using-ct-ng/53099177#53099177
Medium
luxury goods
euphemism
closed access academic journals are evil
websites without OAuth
shower room without a window to the exterior (mould!!!)
single programs with their interface split across multiple windows, e.g. GIMP, ZynAddSubFX
graphical user interfaces
logograms
infinitesimals. Just use limit instead, please
country
knowledge olympiads
programming languages without a decent dominating package system
closed source offline software used by millions
exams
security through obscurities
dots in Gmail address
things in websites that look like links, and behave like links, but don't let you middle click to open them on a separate tab
K-pop
numerical computing language
fiscal paradises
when the front-end of an website changes an important permanent state, but the URL does not change
splash screens: you should show boot messages so that people will know what to Google for when things fail. Do you think computer newbies will be afraid and have nightmares?
milk chocolate: why would you eat that instead of dark chocolate if you are older than 10?
to talk about something without giving the real name to not scare off the audience
mathematical symbol that looks like a Greek letter but isn't. Or perhaps mathematical notation in general
when more than two people gather to play a board game or video game, and two or more people start chatting on and on about random subjects rather than concentrating on the game
watching television while eating. Same for reading, or doing basically anything else but eat. The only acceptable activity is talking relaxedly, not about work.
noises coming out of your bicycle. It is so hard to find where they come to fix them!!!
code drop
private cars as opposed to public transport. As a cyclist, you can just see the effect that large roads have on nearby areas, it just destroys nature.
closed standards
double consonants that make no difference to sound. Dilema? Dilemma? Dillema? Dillemma? Please!
social media websites that show stuff from people you don't follow when you don't explicitly want that, including things which are not ads, just random suggestions. Twitter starting being like that cirac a 2022. Facebook got worse around that time. It is a constant fight against those stupid websites.
- Facebook
  - www.quora.com/How-do-we-turn-off-suggested-anything-on-Facebook-so-that-these-never-show-up-again
- Twitter
  - twitter.com/danbarreirokfan/status/1415328096568360964?lang=en-GB
  - www.quora.com/How-do-I-disable-suggested-topics-on-Twitter
socks with short legs that don't protect your ankle/lower calf from cold/scratches/dirt, e.g. liner socks
Presta valves. Why would such a flimsy tech have become so popular compared to the infinitely superior Schrader!

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Point-contact transistor by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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The first working one in 1947 by John Bardeen and walter Brattain in Bell Labs Murray Hill.

People had already patented a lot of stuff before without being able to make them work. Nonsense.

As the name suggests, this is not very sturdy, and was quickly replaced by bipolar junction transistor.

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1972 Nobel Prize in Physics by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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DNS configuration of Ciro Santilli's website by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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AKA how this GitHub page gets served under the domain: 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 www.cirosantilli.com to the APEX 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

Moved cirosantilli.com to Porkbun 2022-02, unfortunatly records were not automatically updated and domain went down for a bit, upadded to new entries for IPv6 as well which are not documented by GitHub:

TYPE 	HOST	ANSWER	TTL	PRIORITY	OPTIONS
A	cirosantilli.com	185.199.108.153	600
A	cirosantilli.com	185.199.109.153	600
A	cirosantilli.com	185.199.110.153	600
A	cirosantilli.com	185.199.111.153	600
AAAA	cirosantilli.com	2606:50c0:8000::153	600
AAAA	cirosantilli.com	2606:50c0:8001::153	600
AAAA	cirosantilli.com	2606:50c0:8002::153	600
AAAA	cirosantilli.com	2606:50c0:8003::153	600
CNAME	www.cirosantilli.com	cirosantilli.github.io	600

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

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

Custom domain: cirosantilli.com
Enforce HTTPS: checked

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

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1965 Nobel Prize in Physics laureate by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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1955 Nobel Prize in Physics by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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The key initial quantum electrodynamics experiments:

Willis Lamb for the Lamb-Retherford experiment
Polykarp Kusch for the anomalous magnetic dipole moment of the electron, key publication: The Magnetic Moment of the Electron by Kusch and Foley (1948)

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Problem Book in Quantum Field Theory by Voja Radovanovic (2008) by

Ciro Santilli 35  Updated 2025-04-24  +Created 1970-01-01

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www.springer.com/gp/book/9783540770138

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 Pinned article: ourbigbook/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!

Video 1.

Intro to OurBigBook

. Source.

We have two killer features:

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
Video 2.
OurBigBook Web topics demo
. Source.
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:
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
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 2.
You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website
.
Figure 3.
Visual Studio Code extension installation
.
Figure 4.
Visual Studio Code extension tree navigation
.
Figure 5.
Web editor
. 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.
Video 4.
OurBigBook Visual Studio Code extension editing and navigation demo
. Source.
Internal cross file references done right:
Infinitely deep tables of contents:
Figure 6.
Dynamic article tree with infinitely deep table of contents
.
Live URL: ourbigbook.com/cirosantilli/chordate
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

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