Toy model of matter that exhibits phase transition in dimension 2 and greater. It does not provide numerically exact results by itself, but can serve as a tool to theorize existing and new phase transitions.
As mentioned at: stanford.edu/~jeffjar/statmech/intro4.html some systems which can be seen as modelled by it include:
- the spins direction (up or down) of atoms in a magnet, which can undergo phase transitions depending on temperature as that characterized by the Curie temperature and an externally applied magnetic fieldNeighboring spins like to align, which lowers the total system energy.
- the type of atom at a lattice point in a 2-metal alloy, e.g. Fe-C (e.g. steel). TODO: intuition for the neighbor interaction? What likes to be with what? And aren't different phases in different crystal structures?
Also has some funky relations to renormalization TODO.
Bibliography:
The Ising Model in Python by Mr. P Solver
. Source. The dude is crushing it on a Jupyter Notebook.One of the dudes from the AtomSea & EMBII Bitcoin-based file upload system.
- github.com/embiimob
- Real name: likely "Eric Bobby" according to:According to Figure "
Loraine.jpg" however, his mother's name was "Loraine Elizabeth White", so there's some chance his real family name is Mr. White.However according to bitfossil.org/root/937f70bf641ccabaf623772367df64bd867ad44c53fd227d01f2662e74aeacbf/ his daughter is Maddy Bobby, so maybe he is actually Bobby. - twitter.com/EMBII4U
- twitter.com/TheAtomSea/status/990318090738196481 sample link
- x.com/EMBII4U/status/1901769408453718146 possibly retired in 2021 after working as a barista
- he seems to have been quite interested in natural science at around high school before he decided to waste his life as a crypto artist
- x.com/EMBII4U/status/1936278732760666236:
I was science student of the year 1992 all because of molecular biology for real
- x.com/EMBII4U/status/1727331097447428199 a love declaration to Marie Curie
Why can't you collimate incoherent light as well as a laser? by 
Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli 40 Updated 2025-07-16You could put an LED in a cavity with a thin long hole but then, most rays, which are not aligned with the hole, will just bounce inside forever producing heat.
So you would have a very hot device, and very little efficiency on the light output. This heat might also behave like a black-body radiation source, so you would not have a single frequency.
The beauty of lasers is the laser cavity (two parallel mirrors around the medium) selects parallel motion preferentially, see e.g.: youtu.be/_JOchLyNO_w?t=832 from Video "How Lasers Work by Scientized (2017)"
One is reminded of Ulillillia, see also: www.youtube.com/watch?v=9-79yOZ13qg The Story of Ulillillia by Atrocity Guide (2019)
Non-POSIX only here.
As mentioned on the introduction, the main objective of the course is to try predict qualitative properties of materials, notably the existence of certain phase transitions, starting from first principle toy models.
Key phenomena covered include:
New developers won't want to learn your project, because they would rather shoot themselves.
Of course, at some point software gets large enough that things won't fit anymore in 5 seconds. But then you must have either some kind of build caching, or options to do partial builds/tests that will bring things down to that 5 second mark.
A slow build from scratch will mean that your continuous integration costs a lot, money that could be invested in a new developer!
One anecdote comes to mind. Ciro Santilli was trying to debug something, and more experience colleague came over.
To reproduce a problem, ciro was running one command, wait 5 seconds, run a second command, wait 5 seconds, run a third command:
cmd1
# wait 5 seconds
cmd2
# wait 5 seconds
cmd3The first thing the colleague said: join those three commands into one:And so, Ciro was enlightened.
cmd1;cmd2;cmd3
This is a weak point of grep, it can't handle large lines that don't fit fully into memory:
- superuser.com/questions/1703029/is-there-a-limit-for-a-line-length-for-grep-command-to-process-correctly what is the grep line limit?
- unix.stackexchange.com/questions/223078/best-way-to-grep-big-binary-file/758528#758528 Ciro's
bgrepcanon - large not required but mentioning bgrep anyways:
- superuser.com/questions/1368263/use-grep-for-a-long-line-to-get-the-part-of-the-line/1811969#1811969
- unix.stackexchange.com/questions/217936/equivalent-command-to-grep-binary-files/758544#758544
- stackoverflow.com/questions/2034799/how-to-truncate-long-matching-lines-returned-by-grep-or-ack/77263826#77263826
- stackoverflow.com/questions/9988379/how-to-grep-a-text-file-which-contains-some-binary-data leaving this one alone for now
- stackoverflow.com/questions/65674717/how-to-check-if-a-binary-file-is-contained-inside-another-binary-from-the-linux search pattern from file
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!
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 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. 
- 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