Symmetry in mechanics refers to properties or behaviors of mechanical systems that remain unchanged under certain transformations, such as translations, rotations, or reflections. Symmetry plays a fundamental role in understanding the physical behavior of systems, simplifying analyses, and identifying conserved quantities. Here are a few key aspects of symmetry in mechanics: 1. **Types of Symmetry**: - **Translational Symmetry**: A system exhibits translational symmetry if its properties are invariant under shifts in position.
"Ligeti Scholars" typically refers to a network or group of researchers, musicians, and scholars who study the works and contributions of the Hungarian composer György Ligeti. Ligeti (1923-2006) is known for his innovative and influential music, particularly in the realms of contemporary classical music and avant-garde composition.
Half-Life 2: Episode Three was meant to be the third installment in a series of episodic sequels to the critically acclaimed game Half-Life 2, developed by Valve Corporation. Announced alongside Half-Life 2: Episode One in 2006, Episode Three was intended to continue the story of protagonist Gordon Freeman and his struggle against the oppressive Combine forces, picking up where Episode Two left off.
A Hall-effect thruster (HET) is a type of electric propulsion system used primarily in spacecraft. It operates by utilizing the Hall effect to generate thrust through ionized propellant. Here is how it works: 1. **Ionization**: The thruster uses a noble gas, typically xenon, as propellant. Inside the thruster, this gas is ionized by an electric discharge, which turns it into plasma consisting of positively charged ions and free electrons.
GoldSrc is a game engine developed by Valve Corporation, which was the foundation for many popular games, including the original "Half-Life." Over time, numerous mods and modifications have been created using the GoldSrc engine, leading to a wide range of gameplay experiences, enhancements, and entirely new content. Here's a list of some notable GoldSrc mods: 1. **Counter-Strike** - A team-based first-person shooter that became one of the most popular multiplayer games in history.
In theoretical physics and mathematics, a **canonical transformation** refers to a type of transformation between sets of coordinates and momenta in Hamiltonian mechanics that preserves the form of Hamilton's equations.
The Laughlin wavefunction is a product of the field of condensed matter physics and quantum mechanics, specifically relating to the fractional quantum Hall effect (FQHE). It was introduced by Robert Laughlin in 1983 as a theoretical description of the ground state of a two-dimensional electron gas subjected to a strong magnetic field.
The Quantum Hall transition refers to the phenomenon observed in two-dimensional electron systems subjected to strong magnetic fields at low temperatures, leading to quantized Hall conductance. This occurs when the system transitions between different quantum Hall states, characterized by distinct plateaus in the Hall conductance as the magnetic field is varied.
SMART-1, which stands for Small Missions for Advanced Research and Technology, was a European Space Agency (ESA) spacecraft that was launched on September 27, 2003. It was primarily designed as a technology demonstration mission to test various new technologies for future spacecraft.
The Liouville–Arnold theorem, also known as the Liouville–Arnold theorem of integrability, is a result in Hamiltonian mechanics concerning the integrability of Hamiltonian systems. It provides a criterion under which a dynamical system can be considered integrable in the sense of having as many conserved quantities as degrees of freedom, allowing the system to be solved in terms of action-angle variables.
Valentin Danilov is a name that may refer to different individuals or contexts, but the most notable reference is to a Russian scientist and engineer known for his work in the field of computer science and information technology. He has been associated with research related to artificial intelligence, education, and technology.
A trunnion is a cylindrical protrusion used as a mounting or pivoting point in various engineering applications. It typically supports or allows the rotation of a mechanism. Trunnions are most commonly associated with: 1. **Mechanical Engineering**: In machinery, trunnions are used to support rotating parts, such as in the case of a pivot point for a rotating arm or other components.
A turnbuckle is a device used to adjust the tension or length of cables, ropes, or rods. It typically consists of a metal frame with two threaded end fittings that can be turned to tighten or loosen the tension. When the end fittings are turned in opposite directions, the central body of the turnbuckle lengthens or shortens, allowing for precise adjustment of tension in various applications.
In differential geometry, a tautological one-form is a specific type of differential form associated with a principal bundle or a fiber bundle, often used in the context of symplectic geometry and the study of certain geometric structures. For example, let's consider the cotangent bundle \( T^*M \) of a manifold \( M \).
The Weinstein conjecture is a hypothesis in the field of geometric topology and symplectic geometry, formulated by the mathematician Alan Weinstein in the 1970s. It concerns the existence of certain types of periodic orbits in Hamiltonian dynamical systems. More specifically, the conjecture posits that every closed, oriented, and compact contact manifold must contain at least one Reeb chord.
"Badge tether" typically refers to a secure and convenient method for authentication used in various applications, such as accessing physical spaces or digital services. In many cases, it involves using an identification badge that is linked or "tethered" to a person's identity or account, allowing for streamlined access to services or locations. For example, in a workplace setting, a badge tether might allow an employee to gain entry to secure areas simply by presenting their ID badge.
Door furniture refers to the various fittings and fixtures that are used on and around doors. This includes a wide range of hardware components, such as: 1. **Handles and Knobs**: These are used for opening and closing doors. They come in various styles and materials. 2. **Locks and Latches**: Essential for security, these devices keep doors closed and can provide varying levels of access control.
The term "gudgeon" can refer to a couple of different things depending on the context: 1. **Fish**: The most common usage refers to a small freshwater fish belonging to the family Gobiidae. Gudgeons are typically found in Europe and some parts of Asia, inhabiting ponds, rivers, and streams. They are characterized by their elongated bodies and are often considered important for freshwater ecosystems.
"Pintle" can refer to a couple of different concepts, primarily in engineering and maritime contexts: 1. **Pintle as a Mechanical Component**: In mechanical terms, a pintle is a type of bearing or pivot mechanism, typically a short shaft or pin that serves as a hinge or pivot point. Pintles are often used in conjunction with a socket or a similar component to allow for rotational movement. They are commonly found in applications such as steering systems, hinges, or rotating machinery.
The term "segmented spindle" typically refers to a type of mitotic spindle observed during cell division. In a standard mitotic process, the spindle apparatus, which is composed of microtubules, helps in the separation of chromosomes into daughter cells. A segmented spindle is characterized by a non-continuous arrangement of spindle fibers. This can happen in certain cells or under specific conditions, often observed in some types of cancerous cells or during particular stages of cell division.

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