Reanalysis is a scientific method used in climatology and meteorology to produce comprehensive and consistent datasets of past weather and climate conditions. It involves the assimilation of various observational data sources, such as weather station records, satellite measurements, and ocean buoys, into numerical weather prediction models. The goal of reanalysis is to create a long-term, coherent dataset that enables researchers to study climate patterns, trends, and variability over time.
Situational logic is a form of reasoning that focuses on understanding and interpreting situations rather than relying solely on formal rules or abstract principles. It recognizes that the context surrounding a situation can significantly influence the validity of arguments and conclusions. Key aspects of situational logic include: 1. **Context Dependency**: Situations are often unique and can change based on various factors, such as social dynamics, cultural norms, and individual perspectives. Situational logic takes these elements into account when analyzing scenarios.
A computational model is a mathematical or algorithmic representation of a system or process that is used to simulate its behavior, predict outcomes, or analyze its properties. These models are built using computational techniques, allowing for complex systems to be understood and investigated through simulations on computers. Computational models can vary widely in their application and complexity, and they are commonly used in various fields, including: 1. **Physics**: To simulate physical systems ranging from particle interactions to astrophysical phenomena.
The Global Cascades Model is a framework used to understand and analyze the spread of information, behaviors, or phenomena across connected entities, such as individuals, organizations, or networks. This model is particularly relevant in contexts such as social media, marketing, epidemiology, and the diffusion of innovations. ### Key Features of the Global Cascades Model: 1. **Network Structure**: The model typically operates on a network, where nodes represent individuals or entities, and edges represent connections or relationships.
JuMP (Julia Mathematical Programming) is a domain-specific modeling language for mathematical optimization built on the Julia programming language. It provides a high-level interface for defining and solving linear, integer, and nonlinear optimization problems. JuMP allows users to express mathematical models in a way that is both expressive and readable, leveraging Julia's capabilities for performance and array handling.
Minimum-distance estimation is a statistical technique used to estimate parameters of a model by minimizing the distance between theoretical predictions and observed data. It is particularly useful when dealing with models where traditional methods, such as maximum likelihood estimation, are difficult to apply or may not yield valid results. Here’s a basic outline of how minimum-distance estimation works: 1. **Distance Metric**: Define a distance metric that quantifies the discrepancy between the observed data and the model's predictions.
A propagation graph is a type of graphical representation used to illustrate the relationships and flow of information, influence, or effects within a network or a system. It is often employed in various fields, including computer science, systems theory, telecommunications, and social networks, among others. The concept can manifest in different ways depending on the context, but several common applications include: 1. **Signal Propagation**: In telecommunications and networking, propagation graphs can depict how signals or data packets travel through a network.
The "Radiation Law" related to human mobility is often associated with the concept of spatial interactions, specifically in the context of geography and urban planning. It deals with how people move and interact based on the proximity between different locations. This can be compared to the "gravity model" in transportation studies. ### Key Components of Radiation Law: 1. **Distance Decay**: The likelihood of interactions (such as travel or migration) decreases with increasing distance.
A Turing pattern refers to a mathematical model that describes how complex patterns can emerge in biological systems through the interaction of two or more substances that diffuse and react with each other. This concept was introduced by the British mathematician and logician Alan Turing in his 1952 paper titled "The Chemical Basis of Morphogenesis.
A Caccioppoli set is a concept from the field of geometric measure theory, particularly in the study of sets of finite perimeter and variational problems. Named after the Italian mathematician Renato Caccioppoli, this concept plays a crucial role in the regularity theory of solutions to variational problems, such as those arising in the calculus of variations and partial differential equations.
Dirichlet's principle, also known as the Dirichlet principle or the principle of the least action, encompasses various concepts in mathematics and physics. However, one of its most common formulations relates to a principle in variational calculus regarding the solution of boundary value problems.
Hamilton's principle, also known as the principle of stationary action, is a fundamental concept in classical mechanics that states that the path a system takes between two states is the one for which the action is stationary (i.e., has a minimum, maximum, or saddle point).
A Lagrangian system refers to a framework in classical mechanics that is used to analyze the motion of mechanical systems. This approach is based on the principle of least action and utilizes the concept of a Lagrangian function, which is defined as the difference between the kinetic energy (T) and potential energy (V) of a system: \[ L = T - V \] In this context: - **Kinetic Energy (T)**: The energy associated with the motion of the system.
Noether's theorem is a fundamental result in theoretical physics and mathematics that establishes a profound relationship between symmetries and conservation laws. Named after the German mathematician Emmy Noether, the theorem essentially states that for every continuous symmetry of a physical system, there corresponds a conserved quantity. In more precise terms: 1. **Continuous Symmetries**: These are transformations of a physical system that can be performed smoothly and without abrupt changes.
A double pendulum is a system consisting of two pendulums attached end to end. It is an example of a complex mechanical system that exhibits chaotic behavior. The first pendulum is fixed at one end and swings freely, while the second pendulum is attached to the end of the first pendulum and also swings freely. The double pendulum is notable for its rich dynamics; its motion depends on several factors, including the initial angles and velocities of each pendulum.
Iris folding is a paper craft technique that involves creating decorative designs by folding strips of paper in a specific pattern to resemble the shape of an iris (the colored part of an eye). The technique typically involves taking various colors and patterns of paper and arranging them in a spiral or layered fashion that creates a swirling effect, resembling the petals of an iris flower. The process usually begins with a template that outlines the desired design.
In physics, a "field" is a physical quantity that has a value for each point in space and time. Fields are fundamental concepts used to describe various physical phenomena, and they can be categorized into different types depending on their nature and the forces they describe. There are several important types of fields in physics: 1. **Scalar Fields**: These fields are characterized by a single value (a scalar) at every point in space and time.
Potential theory is a branch of mathematical analysis that deals with potentials and potential functions, typically in relation to fields such as electrostatics, gravitation, fluid dynamics, and various areas of applied mathematics. The theory is largely concerned with the behavior of harmonic functions and their properties. At its core, potential theory examines the concept of a potential function, which describes gravitational or electrostatic potentials in physics.
Generalized Clifford algebras are an extension of the standard Clifford algebras defined over a vector space equipped with a quadratic form. They generalize ideas from traditional Clifford algebras to accommodate broader classes of geometrical and algebraic structures. A standard Clifford algebra \( Cl(V, Q) \) is constructed from a finite-dimensional vector space \( V \) over a field (usually the real or complex numbers) together with a non-degenerate quadratic form \( Q \).
The Hunter–Saxton equation is a nonlinear partial differential equation that arises in the study of certain physical and mathematical phenomena, particularly in the context of fluid dynamics and optical pulse propagation.

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