Second brain by Ciro Santilli 40 Updated 2025-07-16
In the 2020's, this refers to writing down everything you know, usually in some graph structured way.
This is somewhat the centerpiece of Ciro Santilli's documentation superpowers: dumping your brain into text form, which he has been doing through Ciro Santilli's website.
This is also the closest one can get to immortality pre full blown transhumanism.
Ciro's still looking for the restore this plaintext backup on a new body though.
It is a good question, how much of your knowledge you would be able to give to others with text and images. It is likely almost all of it, except for coordination/signal processing tasks.
His passion for braindumping like this is a big motivation behind Ciro Santilli's OurBigBook.com work.
Zettelkasten by Ciro Santilli 40 Updated 2025-07-16
zettelkasten.de/posts/overview/ mentions one page to rule them all:
How many Zettelkästen should I have? The answer is, most likely, only one for the duration of your life. But there are exceptions to this rule.
Applejack can refer to a few different things, depending on the context: 1. **Cider**: Traditionally, applejack is a type of alcoholic beverage made from apples, similar to apple cider but with a higher alcohol content. It is produced through the process of freezing cider and removing the ice, which concentrates the alcohol. 2. **Character**: In the realm of popular culture, Applejack is also a character from the animated television series "My Little Pony: Friendship Is Magic.
Brain-in-the-loop by Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli invented this term, derived from "hardware in the loop" to refer to simulations in which both the brain and the body and physical world of organism models are modelled.
Connectome scale by Ciro Santilli 40 Updated 2025-07-16
A Drosophila melanogaster has about 135k neurons, and we only managed to reconstruct its connectome in 2023.
The human brain has 86 billion neurons, about 1 million times more. Therefore, it is obvious that we are very very far away from a full connectome.
Instead however, we could look at larger scales of connectome, and then try from that to extract modules, and then reverse engineer things module by module.
This is likely how we are going to "understand how the human brain works".
This is the most plausible way of obtaining a full connectome looking from 2020 forward. Then you'd observe the slices with an electron microscope + appropriate Staining. Superintelligence by Nick Bostrom (2014) really opened Ciro Santilli's eyes to this possibility.
Once this is done for a human, it will be one of the greatest milestone of humanities, coparable perhaps to the Human Genome Project. BUt of course, privacy issues are incrediby pressing in this case, even more than in the human genome project, as we would essentially be able to read the brain of the person after their death.
As of 2022, the Drosophila connectome had been almost fully extracted.
This is also a possible path towards post-mortem brain reading.
Figure 1. Source. Unconfirmed, but looks like the type of frozen brain where a Microtome would be used.

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