Maxwell's equations with pointlike particles by 
Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01In the standard formulation of Maxwell's equations, the electric current is a convient but magic input.
Would it be possible to use Maxwell's equations to solve a system of pointlike particles such as electrons instead?
The following suggest no, or only for certain subcases less general than Maxwell's equations:
This is the type of thing where the probability aspect of quantum mechanics seems it could "help".
This section is more precisely about classical mechanics.
Ciro Santilli wonders how legal it is. They very explicitly do not mention the words Magic: The Gathering anywhere.
No online play.
Bibliography:
- Subtle is the Lord by Abraham Pais (1982) chapter III "Relativity, the special theory" has a good sketch as you may imagine.
By Andy Haas, an experimental particle physics professor: as.nyu.edu/content/nyu-as/as/faculty/andy-haas.html What an awesome dude!
CIA 2010 covert communication websites SSL certificate by Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01The CGI comms websites contain the only occurrence of HTTPS, so it might open up the door for a certificate fingerprint as proposed by user joelcollinsdc at: news.ycombinator.com/item?id=36280801!
crt.sh appears to be a good way to look into this:They all appear to use either of:
- backstage.musical-fortune.net:
- clients.smart-travel-consultant.com
- members.it-proonline.com
- members.metanewsdaily.com
- miembros.todosperuahora.com
- secure.altworldnews.com
- secure.driversinternationalgolf.com
- secure.freshtechonline.com
- secure.globalnewsbulletin.com
- secure.negativeaperture.com
- secure.riskandrewardnews.com
- secure.theworld-news.net
- secure.topbillingsite.com
- secure.worldnewsandent.com
- ssl.beyondnetworknews.com
- ssl.newtechfrontier.com
- www.businessexchangetoday.com
- heal.conquermstoday.com
- Go Daddy
- Thawte DV SSL CA
- Starfield Technologies, Inc.
crt.sh/?q=globalnewsbulletin.com has a hit to: crt.sh/?id=774803. With login we can see: search.censys.io/certificates/5078bce356a8f8590205ae45350b27f58f4ac04478ed47a389a55b539065cee8. Issued by www.thawte.com/repository/index.html. No hits for certificates with same public key: search.censys.io/search?resource=certificates&q=parsed.subject_key_info.fingerprint_sha256%3A+714b4a3e8b2f555d230a92c943ced4f34b709b39ed590a6a230e520c273705af or any other "same" queries though.
Let's try another one for secure.altworldnews.com: search.censys.io/certificates/e88f8db87414401fd00728db39a7698d874dbe1ae9d88b01c675105fabf69b94. Nope, no direct mega hits here either.
The perfect video game is an infinitely hard one by Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01Ciro once commented that the best game is an infinitely hard one, where you can progress infinitely. To which his great friend J. replied:Or more broadly, one may argue that the perfect video game is life itself, or difficult life goals like making money, becoming famous or changing the world.
Fine, so the perfect game for you is mathematics. Stage one: prove the Riemann hypothesis!
Thinking about it, "infinitely hard" is perhaps not a very precise term, as it could be interpreted as impossible. And if you have mathematical proof that something is impossible, it would be "pointless" to try, trying would be equivalent to pure meditation.
Maybe a better way to put it would be in terms of a difficulty curve. Real life also involves a lot of waiting, either for some experiment to finish running, of for you mental energy to restore a bit.
But so be it, you get the idea.
But this is basically what Ciro feels on every video game. It happens too often on PVE games that things are is either:
- too slow and easy (Ciro would rather skip those with saves made by other)
- or too fast hard, Ciro would rather tool-assisted speedrun those parts
Not to mention the incredible breach of suspension of disbelief of most PvE games where enemies are unbelievably stupid. E.g., why doesn't Bowser just build one fucking wall 15 tiles high to prevent Mario from coming through to his castle? And then put a gate and a hundred guards in front of it? TODO there was a YouTube video of this, I think it was Toad pointing it out to Mario that it is quite weird that Bowser is so stupid, it almost feels like he wants to be beaten.
Maxwell's equations are Lorentz invariant by Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01Subtle is the Lord by Abraham Pais (1982) chapter III "Relativity, the special theory" mentions that this fact and its importance (we want the laws of physics to look the same on all inertial frames, AKA Lorentz covariance) was first fully relized by poincaré in 1905.
And at that same time poincaré also immediately started to think about the other fundamental force then known: gravity, and off the bat realized that gravitational waves must exist. general relativities is probably just "the simplest way to make gravity Lorentz covariant".
lujakob/nestjs-realworld-example-app SQLite port by Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01
Ciro Santilli 37 Updated 2025-05-09 +Created 1970-01-01Tried a quick port to SQLite to get rid of annoying local databases for development, but failed, at c1c2cc4e448b279ff083272df1ac50d20c3304faandthen:fails with:Attempt to hack it:and after that it seems to run.
npm install sqlite3 --save-dev{
"type": "sqlite",
"database": "db.sqlite3",
"entities": ["src/**/**.entity{.ts,.js}"],
"synchronize": true
}npm startDataTypeNotSupportedError: Data type "timestamp" in "ArticleEntity.created" is not supported by "sqlite" database.--- a/src/article/article.entity.ts
+++ b/src/article/article.entity.ts
@@ -20,10 +20,10 @@ export class ArticleEntity {
@Column({default: ''})
body: string;
- @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+ @Column({ default: () => "CURRENT_TIMESTAMP"})
created: Date;
- @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+ @Column({ default: () => "CURRENT_TIMESTAMP"})
updated: Date;I can signup and login, terrible error reporting as usual, make sure to use long enough usernames/passwords.
However, article creation fails with:
Unhandled Rejection (TypeError): Cannot read property 'slug' of undefined
TypeScript is good. It does find errors in your JavaScript. But it is a form of "turd polishing". But Ciro Santilli would rather have a polished turd than a non-polished one.
Part of the reason TypeScript became popular is due to the universality of asset bundlers. Once you are already using an asset bundler, changing the
.js extension into .ts to get a less shitty experience is an easy choice.The other big reason is that JavaScript is so lose with type conversions, notably undefined happily converting to strings without problems, and any missing properties of Object happily being undefined. We should actually use ES6 Map everywhere instead of using Objects as maps.
Since TypeScript is not the default form of the language however, it inevitably happens that you need to add external types for a gazillion projects that are using raw JavaScript, and sometimes fight a lot to get things to work. And so we have: github.com/DefinitelyTyped/DefinitelyTyped. Not sure if this is beautiful, or frightening.
But in the end, as with other type of static linters, TypeScript generally transforms a few hard to debug runtime issues, into a bunch of stupid to solve compile time issues, which is generally a good thing.
The fact that this it parses comments JSDoc comments in JavaScript files is quite amazing.
Examples under typescript. Run each one of them with:Helper:
npx tsc example.ts
node example.jstsr() (
# ts Run
f="$1"
npx tsc "$f"
node "${f%.*}.js"
)
tsr example.ts- typescript/inferFromInit.ts. Should fail with:since TypeScript infers the type of
ifrom first assignment asstring, and we then attempt anumberassignment later on - typescript/inferAfterInit.ts. Does not fail, as the first assignment cannot be computationally determined at runtime without breaking computer science.
- typescript/js-from-ts/main.ts: call JavaScript file typescript/js-from-ts/notmain.js from TypeScript.TODO we are unable to make it typecheck that require, i.e. make that fail, but we've seen cases in complex codebases where that did happen and www.typescriptlang.org/docs/handbook/intro-to-js-ts.html has infinite information on supporting it. So... how to make it fail??
npx tsc jsFromTs.ts && node jsFromTs.js - typescript/functionArgument.ts: basic argument tests
- typescript/functionOptionalArgument.ts:
f(n?: number)
- typescript/functionOptionalArgument.ts:
- typescript/functionOptions.ts:
f({n, s}: {n: number, s: string})
Some major annoyances of TypeScript:
- destructuring assignment in function arguments requires repeating all arguments:
- stackoverflow.com/questions/12710905/how-do-i-dynamically-assign-properties-to-an-object-in-typescript how to dynamically assign properties to objects without defining explicit interfaces? We really need a syntax of type:
const myobj = { i: 2, [s string], } if (something) { myobj.s = 'asdf' }
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!
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-calculusArticles 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/derivativeVideo 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: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.
- 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
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 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. 
- Infinitely deep tables of contents:
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