Malthusian equilibrium refers to a concept in population dynamics and economic theory derived from the work of the British economist and demographer Thomas Robert Malthus, particularly his 1798 work "An Essay on the Principle of Population." In this context, Malthusian equilibrium describes a state where a population's growth is balanced by the means of subsistence available in its environment, leading to a stable population size over time.
A Patlak plot is a graphical analysis tool used primarily in the field of medical imaging, particularly in dynamic positron emission tomography (PET) studies. It is named after the researcher who developed it, Dr. Albert Patlak. The Patlak plot is used to analyze the kinetics of radiotracer uptake in tissues over time, helping to estimate parameters related to tissue perfusion and metabolic activity.
The quasispecies model is a concept in evolutionary biology and virology that describes the dynamics of a population of genetically related organisms, such as viruses, that exist in a state of genetic variability. This model was proposed by the biologist Manfred Eigen in the 1970s and helps explain how populations evolve, particularly under conditions of high mutation rates and selection pressures.
An elastic pendulum is a mechanical system that combines the principles of a traditional pendulum with elastic properties, typically involving a mass (or bob) suspended from a spring or elastic material. The elastic pendulum demonstrates interesting dynamics because the motion is governed by both gravitational forces and spring (or elastic) forces.
Asana-Math is a term that usually refers to a collaborative approach that combines yoga (asana) practices with mathematical concepts or problems. The idea is to create a learning environment where physical movement and mental problem-solving are integrated, promoting both physical well-being and cognitive engagement. In such contexts, practitioners may engage in yoga poses (asanas) that are designed to enhance focus and clarity of mind, which can assist in tackling mathematical challenges.
Minion is a serif typeface designed by Robert Slaughter and released by Adobe in 1990. It is characterized by its classical proportions, which are inspired by the typefaces of the Renaissance period. Minion is known for its readability and elegant design, making it a popular choice for both print and digital applications. The typeface comes in a variety of styles and weights, including regular, italic, bold, and small caps, among others.
The STIX Fonts project, which stands for Scientific and Technical Information Exchange Fonts, is an initiative aimed at creating a comprehensive set of fonts specifically designed for the representation of scientific and technical content. These fonts are intended to support a wide range of mathematical symbols, special characters, and other notations commonly used in academic and scientific publishing.
The paradoxes of infinity refer to various counterintuitive and often perplexing problems or situations that arise when dealing with infinite quantities or sets. These paradoxes challenge our understanding of mathematics, logic, and philosophy. Here are some well-known examples: 1. **Hilbert's Hotel**: This paradox illustrates the counterintuitive properties of infinite sets. Hilbert’s Hotel is a hypothetical hotel with infinitely many rooms, all occupied.
The paradoxes of set theory are surprising or contradictory results that arise from naive set theories, particularly when defining sets and their properties without sufficient constraints. These paradoxes have played a crucial role in the development of modern mathematics, leading to more rigorous foundations. Here are some of the most well-known paradoxes: 1. **Russell's Paradox**: Proposed by Bertrand Russell, this paradox shows that the set of all sets that do not contain themselves cannot consistently exist.
The Staircase Paradox is a thought experiment in the field of mathematics and philosophy, and it typically explores the concepts of motion and infinity. It's often illustrated using a staircase and can be related to the Zeno's paradoxes, particularly the paradox of Achilles and the tortoise. In a typical presentation of this paradox, consider a staircase with a finite number of steps.
The Bertrand paradox is a problem in probability theory that highlights the ambiguities that can arise when dealing with random experiments that seem intuitively straightforward. It was formulated by the French mathematician Joseph Bertrand in the 19th century. The paradox demonstrates that different methods of defining a "random" choice can lead to different probabilities for the same event. The classic version of the Bertrand paradox involves the following situation: 1. **A Circle and a Chord**: Imagine a circle with a diameter.
A Lorentzian manifold is a type of differentiable manifold equipped with a Lorentzian metric. This structure is foundational in the theory of general relativity, as it generalizes the concepts of time and space into a unified framework. Here are the key features of a Lorentzian manifold: 1. **Differentiable Manifold**: A Lorentzian manifold is a differentiable manifold, which means it is a topological space that locally resembles Euclidean space and allows for differential calculus.
Mathematical methods in general relativity refer to the mathematical tools and techniques used to formulate, analyze, and solve problems in the context of Einstein's theory of general relativity. General relativity is a geometric theory of gravitation that describes gravity as the curvature of spacetime caused by mass and energy. This theory uses sophisticated mathematical concepts, particularly from differential geometry, tensor calculus, and mathematical physics.
An Einstein manifold is a Riemannian manifold \((M, g)\) where the Ricci curvature is proportional to the metric tensor \(g\). Mathematically, this relationship can be expressed as: \[ \text{Ric}(g) = \lambda g \] where \(\text{Ric}(g)\) is the Ricci curvature tensor and \(\lambda\) is a constant, often referred to as the "Einstein constant.
Analytical Dynamics is a branch of classical mechanics that focuses on the use of analytical methods to study the motion of particles and rigid bodies. It is concerned with the principles and laws governing systems in motion, utilizing mathematical formulations to describe and predict their behavior. Analytical dynamics can be contrasted with numerical methods or computational approaches, as it emphasizes the development of equations and solutions based on fundamental principles. **Key Concepts of Analytical Dynamics:** 1.
The Bargmann–Wigner equations describe a set of relativistic wave equations for particles with arbitrary spin in the framework of quantum field theory. They are named after Valentin Bargmann and Eugene Wigner, who developed these equations in the context of defining fields for particles with spin greater than \( \frac{1}{2} \). **Key Aspects of The Bargmann-Wigner Equations:** 1.
De Donder–Weyl theory is a framework in theoretical physics and mathematics that generalizes classical Hamiltonian mechanics to systems with an infinite number of degrees of freedom, particularly in the context of field theory. The theory was developed in the late 19th and early 20th centuries by scientists Émile de Donder and Henri Weyl.
"Classical Mechanics" by Kibble and Berkshire is a well-regarded textbook that provides a comprehensive introduction to the principles and applications of classical mechanics. The book covers fundamental concepts in classical mechanics, such as Newton's laws of motion, conservation laws, oscillations, gravitation, and non-inertial reference frames, while also exploring advanced topics like Lagrangian and Hamiltonian mechanics.
Best-Lock is a brand known for creating building block toys that are similar to LEGO bricks but are often offered at a lower price point. The company produces a variety of sets, including themed collections that may cover topics like vehicles, buildings, and scenes from history or fantasy. Best-Lock products generally feature compatible minifigures, vehicles, and accessories, allowing for a similar play experience to that of other popular building block systems.

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