The IBM 7080 is a transistorized mainframe computer that was introduced by IBM in the early 1960s. It was part of the IBM 7000 series and was designed to provide enhanced performance over its predecessor, the IBM 7070, which was based on vacuum tube technology.
This is a general philosophy that Ciro Santilli, and likely others, observes over and over.
Basically, continuity, or higher order conditions like differentiability seem to impose greater constraints on problems, which make them more solvable.
Some good examples of that:
Discrete by Ciro Santilli 40 Updated 2025-07-16
Something that is very not continuous.
Notably studied in discrete mathematics.
And do 5 big queries instead of hundreds of smaller ones.
For example, a README.ciro document that references another document saying:
The \x[speed-of-light] is fast.
needs to fetch "speed-of-light" from the ID database (previously populated e.g. by preparsing light.ciro:
= Light

== Speed of light
to decide that it should display as "Speed of light" (the title rather than the ID).
Previously, I was doing a separate fetch for each \x[] as they were needed, leading to hundreds of them at different times.
Now I refactored things so that I do very few database queries, but large ones that fetch everything during parsing. And then at render time they are all ready in cache.
This will be fundamental for the live preview on the browser, where the roundtrip to server would make it impossible
Infinity by Ciro Santilli 40 Updated 2025-07-16
Chuck Norris counted to infinity. Twice.
There are a few related concepts that are called infinity in mathematics:
Derivative by Ciro Santilli 40 Updated 2025-07-16
The derivative of a function gives its slope at a point.
More precisely, it give sthe inclination of a tangent line that passes through that point.
Chain rule by Ciro Santilli 40 Updated 2025-07-16
Here's an example of the chain rule. Suppose we want to calculate:
So we have:
and so:
Therefore the final result is:
Ship abandonment refers to the situation where a vessel is left by its crew, typically due to dangerous conditions or the ship becoming unmanageable. This can occur in various circumstances, such as severe weather, mechanical failures, or after a ship has run aground. When a ship is abandoned, it may pose environmental hazards, particularly if it is left in navigable waters or if it contains hazardous cargo or materials.
"Tap tap" can refer to a few different things depending on the context: 1. **Tap Tap (App)**: In the context of mobile applications, "Tap Tap" often refers to the app store for Android devices, particularly in regions where Google's Play Store is restricted or unavailable. Tap Tap allows users to download and share apps, games, and other digital content.
Transmetro is a bus rapid transit (BRT) system in Barranquilla, Colombia. It was inaugurated in 2010 and serves as an essential part of the city's public transportation infrastructure. The system is designed to provide efficient, rapid, and reliable transit options for residents and visitors, helping to alleviate traffic congestion and improve air quality in the area. The Transmetro network includes dedicated bus lanes, modern vehicles, and integrated stops that allow for quick boarding and transferring between routes.
Travel technology refers to the use of technological tools, platforms, and applications to enhance the travel experience, improve operational efficiencies in the travel industry, and facilitate the booking and management of travel-related services. This encompasses a wide range of components and innovations, including: 1. **Booking Platforms**: Online travel agencies (OTAs) like Expedia, Booking.com, and Airbnb that allow users to search for and book flights, accommodations, and other travel services.

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