The torsion tensor is a mathematical object that arises in differential geometry and is used in the context of manifold theory, especially in connection with affine connections and Riemannian geometry. It provides a way to describe the twisting or non-symmetries of a connection on a manifold. ### Definition In general, a connection on a manifold defines how to compare tangent vectors at different points, allowing us to define notions such as parallel transport and differentiation of vector fields.
"MacGyver" is a popular television series originally created by Lee David Zlotoff that aired from 1985 to 1992. The show follows the character Angus "Mac" MacGyver, played by Richard Dean Anderson, who is a secret agent known for his resourcefulness and scientific knowledge. Rather than relying on weapons, MacGyver often uses everyday items and creative problem-solving skills to escape dangerous situations and solve complex problems.
Bargaining theory is a framework within economics and game theory that analyzes how individuals or groups negotiate and reach agreements over the allocation of resources, goods, or services. It examines the strategies, behaviors, and outcomes of bargaining situations, where parties have conflicting interests or preferences but seek to find a mutually acceptable solution. Key components of bargaining theory include: 1. **Players**: The individuals or parties involved in the negotiation. They may have different objectives, needs, and available resources.
Determinacy, in a general sense, refers to the property of a system or situation where outcomes are predictable and can be determined based on initial conditions and rules governing the system. It contrasts with indeterminacy, where outcomes cannot be predicted due to the influence of random factors or insufficient information.
Algebraic topology is a branch of mathematics that studies topological spaces with the help of algebraic methods. The fundamental idea is to associate algebraic structures, such as groups or rings, to topological spaces in order to gain insights into their properties. Key concepts in algebraic topology include: 1. **Homotopy**: This concept deals with the notion of spaces being "continuously deformable" into one another.
Relational algebra is a formal system for manipulating and querying relational data, which is organized into tables (or relations). It provides a set of operations that can be applied to these tables to retrieve, combine, and transform data in various ways. Relational algebra serves as the theoretical foundation for relational databases and query languages like SQL.
Topological algebra is an area of mathematics that studies the interplay between algebraic structures and topological spaces. It focuses primarily on algebraic structures, such as groups, rings, and vector spaces, endowed with a topology that makes the algebraic operations (like addition and multiplication) continuous. This fusion of topology and algebra allows mathematicians to analyze various properties and behaviors of these structures using tools and concepts from both fields.
Universal algebra is a branch of mathematics that studies algebraic structures in a generalized framework. It focuses on the properties and relationships of various algebraic systems, such as groups, rings, fields, lattices, and more, by abstracting their common features. Key concepts in universal algebra include: 1. **Algebraic Structures**: These are sets equipped with operations that satisfy certain axioms.
A subliminal channel typically refers to a method of communication that conveys messages below the threshold of conscious perception. This can involve visual, auditory, or digital media that integrates stimuli not readily detectable by the conscious mind. The idea is that these subliminal messages can influence thoughts, feelings, or behaviors without the individual's awareness. For example, in advertising, subliminal messages might include quick flashes of a brand name or sound clips that are so faint as to go unnoticed.
The "Cube" film series is a Canadian science fiction horror franchise that began with the release of the original "Cube" film in 1997, directed by Vincenzo Natali. The series is known for its unique premise, where characters find themselves trapped in a mysterious and deadly maze-like structure composed of interconnected, cube-shaped rooms.
The spacetime triangle diagram technique is a conceptual tool used primarily in theoretical physics, particularly in the context of special relativity and quantum field theory. Though it may not be a widely standardized term, it can refer to methods involving three-dimensional representations or visualizations of spacetime events, particles, and their interactions.
In the context of geometry, a "stub" typically refers to a short or incomplete version of a geometric concept. However, it's important to clarify that the term "stub" is not commonly used in formal geometry vocabulary. In programming and web development, particularly in platforms like Wikipedia, a "stub" usually refers to an article or entry that is incomplete and in need of expansion.
In mathematics, a transformation is a function that maps elements from one set to another, often changing their form or structure in some way. Transformations can be classified into various types depending on their properties and the context in which they are used. Here are a few key types of transformations: 1. **Geometric Transformations**: These are transformations that affect the position, size, and orientation of geometric figures.

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