Telephone by Ciro Santilli 40 Updated 2025-07-16
We are at a point in history where the electrical telegraph is well established.
But people don't want to press letters one by one on a switch. They want to talk!
The first phones appear to have used telegraph lines directly.
Also wired phones don't require modulation, which likely made their development much easier than wireless voice transmission. You just send the signal as a voltage differential directly obtained from the air pressure: how the telephone works.
This section is about telecommunication systems that are based on top of telephone lines.
Telephone lines were ubiquitous from early on, and many technologies used them to send data, including much after regular phone calls became obsolete with VoIP.
These market forces tended to eventually crush non-telephone-based systems such as telex. Maybe in that case it was just that the name sounded like a thing of the 50's. But still. Dead.
Video 1.
Long Distance by AT&T (1941)
Source. youtu.be/aRvFA1uqzVQ?t=219 is perhaps the best moment, which attempts to correlate the exploration of the United States with the founding of the U.S. states.
Telex by Ciro Santilli 40 Updated 2025-07-16
Not a telephone-based system, needing its own network, and was killed particularly by fax which is. Telex evolved from the Telegraph, which is a binary system at the physical layer.
Video 1.
Siemens T1000 Fernschreiber by dragonforces (2015)
Source.
Fax by Ciro Santilli 40 Updated 2025-07-16
Uses telephone lines, and therefore were still usable much much after the Internet made them obsolete, which is quite funny.
Video 1.
Teletype ASR 33 Part 10: ASR 33 demo by CuriousMarc (2020)
Source.
Video 2.
Fax Machine by Museum of Obsolte Objects (2011)
Source.
Autodidacticism by Ciro Santilli 40 Updated 2025-07-16
There are two types of people:
  • those who are autodidacts
  • those who didn't really learn
Some possible definitions:
  • learning without a gun pointed at your head
  • learning from an e-book or video rather than from a talking head 5 rows of chairs in front of you
    How that is different from a video, you tell me.
Paulo Freire by Ciro Santilli 40 Updated 2025-07-16
en.wikipedia.org/wiki/Paulo_Freire:
During his childhood and adolescence, Freire ended up four grades behind, and his social life revolved around playing pick-up football with other poor children, from whom he claims to have learned a great deal. These experiences would shape his concerns for the poor and would help to construct his particular educational viewpoint. Freire stated that poverty and hunger severely affected his ability to learn. These experiences influenced his decision to dedicate his life to improving the lives of the poor: "I didn't understand anything because of my hunger. I wasn't dumb. It wasn't lack of interest. My social condition didn't allow me to have an education. Experience showed me once again the relationship between social class and knowledge"
OMG so nice.
Kingdom (biology) by Ciro Santilli 40 Updated 2025-07-16
There's six to eight in different systems of the end of the 20th century:This mess is because people don't realize that clades are all that really matter.
Phylum by Ciro Santilli 40 Updated 2025-07-16
There's about 60 of them.

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 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.
  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