A foot per second (ft/s or ft/sec) is a unit of speed or velocity that indicates how many feet are traveled in one second. It is part of the imperial system of measurement and is commonly used in the United States for various applications, including engineering, physics, and everyday life.
T-symmetry, or time reversal symmetry, is a concept in physics that refers to the invariance of the laws of physics under the reversal of the direction of time. In other words, a physical process is said to exhibit T-symmetry if the fundamental equations governing the dynamics of the system remain unchanged when the time variable is replaced by its negative (\(t \rightarrow -t\)).
Gunter's chain is a measurement tool used in surveying, particularly in the field of land surveying. It is named after the English mathematician Edmund Gunter, who introduced it in the early 17th century. The chain consists of a series of linked metal pieces or "links," each typically measuring 7.92 inches (or 20.1 centimeters) long. A complete Gunter's chain traditionally comprises 100 links, making the total length 66 feet (or 20.
A Tornado Debris Signature (TDS) is a specific pattern observed in radar data that indicates the presence of a tornado and the associated debris being lifted into the atmosphere. When a tornado occurs, it can pick up various materials from the ground, such as dirt, leaves, and man-made objects, and fling them into the air. This debris can create a distinct radar signature. Meteorologists use Doppler radar to detect these signatures during storm events.
Ukrainian biophysicists are scientists from Ukraine who specialize in the field of biophysics, which is an interdisciplinary area that combines principles from physics and biology to study biological systems. Biophysicists often focus on understanding the physical properties and behaviors of biological molecules, cells, and organisms, employing techniques from physics to explore complex biological processes.
Underwater diving explorers are individuals or groups who engage in the exploration of underwater environments, such as oceans, lakes, rivers, and other bodies of water. This exploration can involve a variety of activities, including scientific research, archaeological investigations, marine conservation, and recreational diving. These explorers may use various diving techniques and equipment, such as scuba gear, rebreathers, or submersibles, to conduct their activities.
Underwriting profit refers to the profit that an insurance company earns from its core business of underwriting insurance policies. It is calculated by taking the total premiums collected from policyholders and subtracting the costs associated with underwriting, such as claims, expenses, and losses incurred during a specific period.
Uriel Feige is a notable computer scientist known for his work in theoretical computer science, particularly in the areas of computational complexity theory and graph theory. He has contributed to various topics such as approximation algorithms, algorithms on graphs, and the study of computational problems.
"Vehicles by brand" typically refers to the various automobile models and types manufactured by specific automotive brands or companies. Each brand usually offers a range of vehicles, such as sedans, SUVs, trucks, and hybrids or electric vehicles. Some well-known automotive brands include: 1. **Toyota** - Known for models like the Camry, Corolla, RAV4, and Prius. 2. **Ford** - Offers vehicles such as the F-150, Mustang, and Explorer.
I guess ended up doing all the "how things should look like" features because they clarify what the website is supposed to do, and I already have my own content to bring it alive via
ourbigbook --web upload.But now I honestly feel that all the major elements of "how things should look like" have fallen into place.
I was really impressed by Trillium Notes. I should have checked it long ago. The UI is amazing, and being all Js-based, could potentially be reused for our purposes. The project itself is a single-person/full trust notetaking only for now however, so not a direct replacement to OurBigBook.
Ciro's Edict #7 Email verification and reCAPTCHA signup protection by
Ciro Santilli 40 Updated 2025-07-16
Added this basic but fundamental protection layer to the website.
The email setup will of course be reused when notifications are eventually implemented.
Every article now has a (very basic) GitHub-like issue tracker. Comments now go under issues, and issues go under articles. Issues themselves are very similar to articles, with a title and a body.
This was part of 1.0, but not the first priority, but I did it now anyways because I'm trying to do all the database changes ASAP as I'm not in the mood to write database migrations.
Here's an example:
- ourbigbook.com/go/issue/2/donald-trump/atomic-orbital a specific issue about the article "Atomic Orbital" by Donald Trump. Note the comments possibly by other users at the bottom.
- ourbigbook.com/go/issues/1/donald-trump/atomic-orbital list of issues about the article "Atomic Orbital" by Donald Trump
You can now write:in lieu of the old:
<Blue cats> are nice.
= Blue cat
= Big blue cat
{parent=Blue cat}\x[blue-cat]{c}{p} are nice.
= Blue cat
= Big blue cat
{parent=blue-cat}Binary stars are systems consisting of two stars that are bound together by their mutual gravitational attraction and orbit a common center of mass. These systems can be classified into several types based on the nature of their orbits and the way they are observed: 1. **Visual Binaries**: These binary stars can be distinguished as separate stars through a telescope. They are visually observable, and their orbits can be tracked over time.
A moment is a measure of the tendency of a force to rotate an object about an axis or point. In physics and engineering, it is often referred to in terms of "torque." The moment of a force is calculated by multiplying the force applied by the distance from the point of rotation (also known as the moment arm or lever arm) to the line of action of the force.
The planetary core is the innermost layer of a planet, typically composed of dense materials, primarily metals like iron and nickel, though it can also contain lighter elements such as sulfur and oxygen. The structure and composition of a planetary core vary among different celestial bodies, but they generally play a crucial role in a planet's geology and magnetic field generation. ### Key Characteristics: 1. **Composition**: The core is usually made of heavy metals, and in some cases, may include lighter materials.
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






