Busy Beaver Challenge by Ciro Santilli 40 Updated 2025-07-16
Project trying to compute BB(5) once and for all. Notably it has better presentation and organization than any other previous effort, and appears to have grouped everyone who cares about the topic as of the early 2020s.
Very cool initiative!
Borlotti beans by Ciro Santilli 40 Updated 2025-07-16
This looks a lot like the beans that Brazilians venerate and can be easily found in the United Kingdom as of 2020.
The more exact type seems to be pinto bean, but this is close enough.
2021-03: same but 2.5 teaspons, seems to be the right ammount.
2021-02-10: attempt 3: 500g 1 hour 30 minutes no pressure, uncontrolled water. Salt with one chorizo: put 3 teaspoons, it was a bit too much, going to do 2 next time and see.
2020-12-14: attempt 3: 250g of beans, 1.5l of water, 30 minutes pressure.
2020-11-30: attempt 2: 275ml of dry beans, about 50% of 500g bag, putting 1650 ml (6x) of water on pressure cooker Still had to throw out some water.
Density dry raw: 216 g/250 ml = 432 g / 500 ml = 500 g / 580 ml = 864 g/L
500 g dry expands to in water after 12 hours: 1200 ml
Therefore 500 g dry = 864 / 2 L = 432 ml expands about 3x.
Therefore, to the maximum 2.5L of the cooker with 8x dry volume water from this recipe I can use:
2500 = volume expanded bean + volume water = 3 volume dry bean + 8 volume dry bean = 11 volume dry bean
and so:
volume dry bean = 2500/11 = 227ml
which is about 227 / 580 = 40% of the 500 g bag.
After first try, I found that 8x volume of water is way, way too much. Going to try 6x next time.
Common sense by Ciro Santilli 40 Updated 2025-07-16
Video 1.
My Job is to Open and Close Doors by Mattias Pilhede (2019)
Source. An interesting humorous short meditation on common sense.
Charles Simon by Ciro Santilli 40 Updated 2025-07-16
Basically it looks like the dude got enough money after selling some companies, and now he's doing cooler stuff without much need of money. Not bad.
Ring signature by Ciro Santilli 40 Updated 2025-07-16
Used for example:
PageRank by Ciro Santilli 40 Updated 2025-07-16
When Ciro finally understood that this is a play on Larry Page's name (of course it is, typical programmer/academic humor stuff), his mind blew.
Gridworld AI game by Ciro Santilli 40 Updated 2025-12-13
This is one of the most canonical examples of "Cult leader Jesus tries to divert faith from an old religion into his own".
AlphaGo Zero by Ciro Santilli 40 Updated 2025-07-16
Figure 1.
AlphaGo Zero cheat sheet by David Foster (2017)
Source.

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!
We have two killer features:
  1. 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
  2. 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.
    Figure 2.
    You can publish local OurBigBook lightweight markup files to either https://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.
  3. https://raw.githubusercontent.com/ourbigbook/ourbigbook-media/master/feature/x/hilbert-space-arrow.png
  4. Infinitely deep tables of contents:
    Figure 6.
    Dynamic article tree with infinitely deep table of contents
    .
    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