Yield strength anomaly refers to unusual behavior observed in the yield strength of certain materials under specific conditions, often deviating from the expected mechanical properties based on established theories or models. This phenomenon can occur in various materials, including metals and alloys, and can be influenced by factors such as temperature, strain rate, microstructural changes, or the presence of defects and impurities.
Long-duration gamma-ray bursts (GRBs) are extremely energetic explosions observed in distant galaxies that are characterized by their prolonged emission of gamma rays. These events are among the most powerful explosions in the universe and are typically associated with the collapse of massive stars, which can lead to the formation of black holes or neutron stars.
GRB 221009A is a gamma-ray burst (GRB) that was detected on October 9, 2022. It gained significant attention in the astronomical community due to its extraordinary brightness and duration, marking it as one of the most intense and energetic gamma-ray bursts recorded. GRBs are among the most powerful explosions in the universe, typically associated with the collapse of massive stars or the merging of neutron stars.
Vela was a series of satellites launched by the United States starting in the 1960s, primarily intended for detection of nuclear explosions in the atmosphere and space. The Vela program was part of the U.S. effort to monitor compliance with nuclear test ban treaties. The satellites were equipped with advanced sensors capable of detecting the light and radiation emitted during a nuclear explosion.
Weather insurance is a type of insurance that provides financial protection against losses resulting from adverse weather conditions. It is often used by businesses and individuals whose operations or income are affected by weather events, such as farmers, event planners, and outdoor venues. Here are some key points about weather insurance: 1. **Coverage Types**: Weather insurance can cover various weather-related events, such as droughts, excessive rain, snow, frost, or high temperatures. The specific terms of coverage depend on the policy.
A Markov number is a specific type of positive integer that is associated with a particular solution to Markov's equation, which is given by: \[ x^2 + y^2 + z^2 = 3xyz \] where \( x \), \( y \), and \( z \) are positive integers. A set of numbers \( (x, y, z) \) that satisfies this equation is called a Markov triple.
Pell's equation is a specific type of Diophantine equation, which is an equation that seeks integer solutions. It is typically expressed in the form: \[ x^2 - Dy^2 = 1 \] Here, \( x \) and \( y \) are integers, and \( D \) is a positive integer that is not a perfect square. The main objective is to find integer pairs \((x, y)\) that satisfy this equation.
A **primitive Pythagorean triple** consists of three positive integers \( (a, b, c) \) that satisfy the equation \( a^2 + b^2 = c^2 \) and have a greatest common divisor (gcd) of 1, meaning they are coprime.
The Sum of Four Cubes Problem refers to the mathematical question of whether every integer can be expressed as the sum of four integer cubes.

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