There is value in tutorials written by early pioneers of the field Updated 2025-07-16
Everyone is beginner when the field is new, and there is value in tutorials written by beginners.
For example, Ciro Santilli felt it shocking how direct and satisfying Richard Feynman's scientific vulgarization of quantum electrodynamics were, e.g. at: Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979), and that if he had just assumed minimal knowledge of mathematics, he was about to give a full satisfactory picture in just a few hours.
Other supporters of this:
- Ron Maimon: the same also applies to early original papers of the field, not just tutorials
- Dean Kamen: quick mention at: fi.edu/en/awards/laureates/dean-kamen, but a better longer mention on Dreamer (2020), nearby section from trailer: youtu.be/Cj2VKVJKf1I?t=16
Concurrent Versions System Updated 2025-07-16
It is said, that once upon a time, programmers used CSV and collaborated on SourceForge, and that everyone was happy.
These days, are however, long gone in the mists of time as of 2020, and beyond Ciro Santilli's programming birth.
Confucianism Updated 2025-07-16
Connected components of the orthogonal group Updated 2025-07-16
The orthogonal group has 2 connected components:
- one with determinant +1, which is itself a subgroup known as the special orthogonal group. These are pure rotations without a reflection.
- the other with determinant -1. This is not a subgroup as it does not contain the origin. It represents rotations with a reflection.
It is instructive to visualize how the looks like in :
- you take the first basis vector and move it to any other. You have therefore two angular parameters.
- you take the second one, and move it to be orthogonal to the first new vector. (you can choose a circle around the first new vector, and so you have another angular parameter.
- at last, for the last one, there are only two choices that are orthogonal to both previous ones, one in each direction. It is this directio, relative to the others, that determines the "has a reflection or not" thing
As a result it is isomorphic to the direct product of the special orthogonal group by the cyclic group of order 2:
A low dimensional example:because you can only do two things: to flip or not to flip the line around zero.
Note that having the determinant plus or minus 1 is not a definition: there are non-orthogonal groups with determinant plus or minus 1. This is just a property. E.g.:has determinant 1, but:so is not orthogonal.
Endofunction Updated 2025-07-16
ENIAC Updated 2025-07-16
Stack Overflow Updated 2025-07-16
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.
Stack Overflow in a nutshell
. Source. As the "WTF look at my points" guy, Ciro Santilli approves of this meme. A few more elements could be added, notably deletion of the last link-only answer, but good enough.
By the profile image, the "Grammar Nazi" editor is actually appropriately the notorious serial editor Peter Mortensen. Ciro Santilli welcomes grammar fixes, but more subjective style fixes can be a bit annoying.
Catching mice by Nakanoart
. Possible non-canonical source: twitter.com/nixcraft/status/1376023938749190147 The Social Network Updated 2025-07-16
Thiel Fellowship Updated 2025-07-16
Ciro Santilli approves of this one, related: Section "Free gifted education".
The downside of the Thiel Fellowship is that it is realistically impossible for its fellows to do anything in deep tech, only information science startups would be possible, as they would not have the labs, or lab skills required for any deep tech if they drop out before a PhD. Related: Section "The only reason for universities to exist should be the laboratories".
The only solution is the harder process of actually remodelling our very broken educational system.
Equity (finance) Updated 2025-07-16
Eric W. Weisstein Updated 2025-07-16
Ahh, this dude is just like Ciro Santilli, trying to create the ultimate natural sciences encyclopedia!
Essential fatty acid Updated 2025-07-16
Eta (letter) Updated 2025-07-16
nodejs/sequelize/raw/parallel_update_async.js Updated 2025-07-16
Conservation laws in Schrodinger equations Updated 2025-07-16
TODO is there any good intuitive argument or proof of conservation of energy, momentum, angular momentum?
Content moderation Updated 2025-07-16
gothinkster/realworld Updated 2025-07-16
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.:Note that all those frontends communicate with the same backend.
- 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
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/apiso 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:Then just:on both server and client, and then visit the client URL: localhost:4100/
- 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 supportThis 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;
npm install
npm startYou 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: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.
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 All science is either physics or stamp collecting Updated 2025-07-16
All the financial advice you’ll ever need fits on a single index card Updated 2025-07-16
Continuous spectrum (functional analysis) Updated 2025-07-16
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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