Ciro Santilli @cirosantilli 37

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Eta (letter) Updated 2025-07-16

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Lowercase looks like a lowercase letter N for some reason.

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nodejs/sequelize/raw/parallel_update_async.js Updated 2025-07-16

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Conservation laws in Schrodinger equations Updated 2025-07-16

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physics.stackexchange.com/questions/229885/energy-equation-in-quantum-mechanics

TODO is there any good intuitive argument or proof of conservation of energy, momentum, angular momentum?

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How to contact Ciro Santilli Updated 2025-07-26

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Ciro Santilli is very happy to meet people with related interests, he really loves his like-minded online friends. Even if you don't have something a specific goal in mind for the contact, please just say hi.

To contact Ciro publicly about any general subject that is not covered in a more specific GitHub repository, including saying hi or suggestions about his website either:

create a GitHub issue at: github.com/cirosantilli/cirosantilli.github.io/issues/new or Giscus thread
at mention Ciro's main Twitter account

For comments about China, first read:

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

Publicly viewable contact is preferred if possible to more effectively share Ciro's wisdom with the world.

But if you feel more comfortable with private contact, no problem, either:

email: username cirosantilli with provider ProtonMail which has domain name proton.me. Note that Ciro also controls the Gmail address with that same username, and keep in mind that dots are ignored in Gmail addresses. But ProtonMail preferred because why should we give our private minds to the CIA by default? Push notifications disabled.
Signal: username cirosantilli.89 signal.me/#eu/BuJjV0enXYTOnFFc1FZV5LFcWodL1a2Oy9VZ5uyQU7xrYxqw+npIcaHBqghWudrI. 89 is a reference to Ciro Santilli's birth year 1989. Push notifications enabled, but treat like email unless we are actively chatting back and forth.

For other less good methods that will also likely work, use direct messages of the following profiles from under Section "Accounts controlled by Ciro Santilli":

LinkedIn: www.linkedin.com/in/cirosantilli
Reddit: www.reddit.com/user/cirosantilli
Facebook: www.facebook.com/cirosantilli
Telegram: telegram.me/cirosantilli. Note that end-to-end encryption is present on secret chats only, which don't have device sync. Ridiculous.

Ciro's Twitter DMs are also open, but note that Ciro receives endless Chinese language SPAM there which Twitter is doing nothing to combat, so it's not as reliable.

If you are a privacy freak or are going to tell Ciro state secrets Ciro has this GNU Privacy Guard public key: pubkey.gpg, but it's not something that he has ever really used.

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.

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Content moderation Updated 2025-07-16

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gothinkster/realworld Updated 2025-07-16

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github.com/gothinkster/realworld

Ciro Santilli's implementation: node Express Sequelize Next.js realworld example app.

Ahh, you can't have new ideas anymore!

Basically puts together every backend with Front-end web framework to create the exact same website.

The reference live demo can be found at: demo.realworld.io/#/ It is based on Angular.js as it links to: github.com/gothinkster/angularjs-realworld-example-app TODO backend?

There are however also live demos of other frontends, e.g.:

React: react-redux.realworld.io. But note that tag addition at post creation is broken there as of March 2021, but not on master: github.com/gothinkster/react-redux-realworld-example-app/issues/151#issuecomment-808417846 so they forgot to update the live server.
Vue.js: vue-vuex-realworld.netlify.app

Note that all those frontends communicate with the same backend.

As of 2021 Devs are seemed a bit too focused on monetizing the project through their "how to use this project" premium tutorial, and documentation could be better: just getting the hello world of the most popular backend with the most popular frontend is not easy... come on.

github.com/gothinkster/realworld/issues/578 asks for community support, as devs have moved on since unfortunately.

Remember:

by default, the frontends hardcode the upstream public data API: https://conduit.productionready.io/api so you have to hack their code to match the port of the backend. And each backend can have a different port.
when you switch between backends, you must first manually clear client-side storage cookies/local new run will fail due to authentication issues!

Important missing things from the minimum base app:

server-side rendering:
- github.com/arrlancore/nextjs-ssr-real-world-app-example. As advertised, that global instance does render with JavaScript disabled! Proposed for upstream at: github.com/gothinkster/realworld/issues/423
- github.com/gothinkster/realworld/issues/266
no javaScript bi-directional communication library built-in... come on: github.com/gothinkster/realworld/issues/107
email notifications however as tested on the live demo: demo.realworld.io/#/
error handling is broken/missing/inconsistent across apps

First you should the most popular backend/frontend combination running, which is the most likely to be working. We managed to run on Ubuntu 20.10, React + Node.js Express.js as described at github.com/gothinkster/node-express-realworld-example-app/pull/116:

github.com/cirosantilli/node-express-realworld-example-app/tree/mongo4 which has a simple patch on top of github.com/gothinkster/node-express-realworld-example-app/tree/ba04b70c31af81ca7935096740a6e083563b3a4a for MongoDB 4 support
This requires you to first install MongoDB on Ubuntu and ensure you can login to it from the command line.

github.com/gothinkster/react-redux-realworld-example-app/tree/9186292054dc37567e707602a15a0884d6bdae35 patched to use the correct server host/port localhost:3000:

diff --git a/src/agent.js b/src/agent.js
index adfbd72..e3cdc7f 100644
--- a/src/agent.js
+++ b/src/agent.js
@@ -3,7 +3,7 @@ import _superagent from 'superagent';

 const superagent = superagentPromise(_superagent, global.Promise);

-const API_ROOT = 'https://conduit.productionready.io/api';
+const API_ROOT = 'http://localhost:3030/api';

 const encode = encodeURIComponent;
 const responseBody = res => res.body;

Then just:

npm install
npm start

on both server and client, and then visit the client URL: localhost:4100/

You have to hit the Enter key to add tags, it's terrible: github.com/gothinkster/react-redux-realworld-example-app/issues/151#issuecomment-808417846

One cool thing is that the main repo has unified backend API tests:

git clone https://github.com/gothinkster/realworld
cd realworld
git checkout e7adc6b06b459e578d7d4a6738c1c050598ba431
cd api
APIURL=http://localhost:3000/api USERNAME="u$(date +%s)" ./run-api-tests.sh

so the per-repository tests are basically useless, and that single test can test everything for any backend! There is no frontend testing however: github.com/gothinkster/realworld/issues/269 so newb.

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All science is either physics or stamp collecting Updated 2025-07-16

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26 parameters of the Standard model on the blackboard. If one of those parameters should happen to be erased, 25 parameters of the Standard model on the blackboard....

But certainly, mathematics is not a part of.

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All the financial advice you’ll ever need fits on a single index card Updated 2025-07-16

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This is a good concept. For the ammount most people save, having a simple and easy to apply investment thesis is the best way to go.

Video 1.

All the financial advice you’ll ever need fits on a single index card

. Source.

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Continuous spectrum (functional analysis) Updated 2025-07-16

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Unlike the simple case of a matrix, in infinite dimensional vector spaces, the spectrum may be continuous.

The quintessential example of that is the spectrum of the position operator in quantum mechanics, in which any real number is a possible eigenvalue, since the particle may be found in any position. The associated eigenvectors are the corresponding Dirac delta functions.

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Controlled quantum gate Updated 2025-07-16

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Controlled quantum gates are gates that have two types of input qubits:

control qubits
operand qubits (terminology made up by Ciro Santilli just now)

These gates can be understood as doing a certain unitary operation only if the control qubits are enabled or disabled.

The first example to look at is the CNOT gate.

Figure 1.
Generic controlled quantum gate symbol
. Source.
The black dot means "control qubit", and "U" means an arbitrary Unitary operation.
When the operand has a conventional symbol, e.g. the Figure "Quantum NOT gate symbol" for the quantum NOT gate to form the CNOT gate, that symbol is used in the operand instead.

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The CSS of Ciro Santilli's website looks broken Updated 2025-07-16

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That which does not exist, cannot be broken.

And of course:

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Cool data embedded in the Bitcoin blockchain / AtomSea & EMBII data format Updated 2025-07-16

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For a detailed analysis of one transaction see: Nelson-Mandela.jpg.

Best guess so far, all in ASCII hex of output scripts:

remove the single output value different from first one from payload, that's the change, and it is randomly placed as far as I see
64 bytes: hex address of top level text
1 byte: some random punctuation
decimal number of bytes of some payload
1 byte: some random punctuation
64 bytes: same as the first address
CR LF
ends in NUL

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Cool data embedded in the Bitcoin blockchain / Bibliography Updated 2025-07-16

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Other Bitcon analysis:

"Annotated blockchain project"
- etherpad.mit.edu/p/r.e33d2e7230fafc0612a0f2e7ebc87bae
- etherpad.mit.edu/p/r.19b7b3e2c5ea08a61cb0bef0aeb213fd image list (February 8, 2017) We tried going over it, but it is just too much work, the huge majority of the results are just AtomSea & EMBII so not that interesting.
- archive.ph/Zz7m5
- www.reddit.com/r/Bitcoin/comments/5wax5v/a_group_is_working_on_building_a_fully_annotated/
- archive.4plebs.org/pol/thread/111742853/
Does the same as this page, just that it is an uncomprehensible mess of broken links. But they have soe good ideas!
Their main techniques seem to be:
```
mkdir binout
for file in blk*dat; do echo "$file"; binwalk --dd='.*' "$file" -C binout/. --log=binout/"$file""res.txt"; done
```
and:
```
mkdir subfileout
for file in blk*dat; do mkdir subfileout/"$file"; done
for file in blk*dat; do echo "$file"; hachoir-subfile --category=image,video,audio,container,archive,misc "$file" subfileout/"$file" > subfileout/"$file""subfile.txt"; done
```
which seem promising.
These are installable on Ubuntu 23.10 with:
```
sudo apt install binwalk hachoir
```
TODO how to they automatically map back to transaction IDs? There is a line "Script to add the TX ID to each file." Our attempts: Section "Get transaction id from position in dat file"

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Why is COVID-19 so serious in some people but not in others? Updated 2025-07-16

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There are a few possibilities:

genetics
- bibliography:
  - www.science.org/doi/10.1126/scitranslmed.abj7521 Identification of driver genes for critical forms of COVID-19 in a deeply phenotyped young patient cohort by Carapito et al. (2021)
state of the immune system based on disease history
age