The R* rule, or R* theory, is a concept in ecology that describes the relationship between resource availability and the growth and survival of competing species. The term was popularized by ecologist Bob Holt and refers to the minimum level of resource concentration that a species needs to survive and reproduce.
Yael Tauman Kalai is a prominent researcher in the fields of computer science and cryptography. She is particularly known for her work on cryptographic algorithms, secure multiparty computation, and related areas. Kalai has contributed to the development of theoretical frameworks and practical applications in cryptography, enhancing the security and efficiency of various cryptographic systems. Her work often intersects with other areas in computer science, including algorithms and complexity theory.
Coexistence theory is a concept in ecology and evolutionary biology that explores how multiple species can coexist in the same habitat without one outcompeting the others to extinction. The theory addresses the mechanisms and conditions under which species can share resources and maintain stable populations. Key components of coexistence theory include: 1. **Niche Differentiation**: Coexisting species often exploit different resources or use the same resources in different ways (niche partitioning), which reduces direct competition.
The Correspondence Theory of Truth is a philosophical concept that posits that the truth of a statement or proposition is determined by how accurately it reflects or corresponds to reality or the actual state of affairs. In simpler terms, a statement is considered true if it matches or aligns with the facts or the way things actually are. For example, the statement "The sky is blue" is true if, in fact, the sky is blue at a given time and place.
A transcomputational problem refers to a type of computational problem that exceeds the capabilities of any Turing machine or, more broadly, exceeds the limits of computability as defined by the Church-Turing thesis. This means that such problems cannot be solved by any algorithm or computational process that can be performed by a Turing machine, which serves as a fundamental model of computation in computer science.
Undecidable problems are problems for which no algorithm can be constructed that will always lead to a correct yes-or-no answer. This means that there is no general procedure or method that can solve these problems for all possible inputs. Here is a list of some well-known undecidable problems: 1. **Halting Problem**: Given a description of a program and an input, determine whether the program will eventually halt (finish running) or continue to run forever.
A *nondeterministic algorithm* is a theoretical model of computation that allows multiple possibilities for each decision point in its execution. In other words, rather than following a single, predetermined path to reach a solution, a nondeterministic algorithm can explore many different paths simultaneously or choose among various possibilities at each step.
Eötvös rule, named after Hungarian physicist Loránd Eötvös, is an empirical rule in geophysics that describes the relationship between the density of a fluid and the gravitational force acting on it. Specifically, it states that the gravitational attraction of a fluid is proportional to its density when considering the gravitational potential difference over a vertical column of that fluid.
Cartesian doubt is a philosophical method associated with René Descartes, a 17th-century French philosopher, mathematician, and scientist. This method involves systematic skepticism about the validity of one’s beliefs and knowledge claims in order to establish a foundation for true knowledge. Descartes employed this technique in his work "Meditations on First Philosophy," where he sought to identify what can be known with absolute certainty.
Boltzmann's entropy formula is a fundamental equation in statistical mechanics that relates the entropy \( S \) of a system to the number of microstates \( \Omega \) associated with that system. The formula is expressed as: \[ S = k \ln \Omega \] where: - \( S \) is the entropy of the system. - \( k \) is Boltzmann's constant (\( k \approx 1.
The Gibbs–Duhem equation is a relationship in thermodynamics that describes the changes in the chemical potential of a system in relation to its temperature, pressure, and composition. It arises from the fundamental thermodynamic definition of the differential change in the Gibbs free energy \( G \).
Isentropic expansion waves refer to a type of wave that occurs in compressible fluid dynamics, particularly in the context of gas dynamics and supersonic flows. The term "isentropic" implies that the process is both adiabatic (no heat transfer) and reversible (no entropy generation). ### Key Concepts: 1. **Isentropic Process**: An isentropic process is one in which the entropy remains constant.
Heat capacity is a physical property of a substance that measures the amount of heat energy required to change its temperature by a certain amount. It quantifies how much heat is needed to raise the temperature of a material based on its mass and specific heat capacity. There are two key concepts related to heat capacity: 1. **Specific Heat Capacity**: This is the amount of heat required to raise the temperature of one unit mass of a substance by one degree Celsius (or one Kelvin).
The coil–globule transition is a phenomenon observed in polymer science, particularly in the behavior of macromolecules such as proteins and synthetic polymers in solution. This transition refers to the change in the conformation of a polymer chain from a random coil (expanded, flexible form) to a globule (compact, more ordered form) in response to certain environmental conditions.
In thermodynamics, conjugate variables are pairs of physical quantities that are related to each other in a specific way, typically in the context of work and energy interactions in a thermodynamic system. Conjugate variables often arise in the context of the first and second laws of thermodynamics and are fundamental to understanding the relationships between different forms of energy and the processes that occur in thermodynamic systems.
Richard Mollier (1863–1935) was a notable German engineer and physicist, best known for his contributions to the field of thermodynamics, particularly in the study of psychrometrics and the behavior of moist air. He developed the "Mollier diagram," also known as the enthalpy-entropy diagram, which graphically represents the relationships between various thermodynamic properties of moist air, such as temperature, humidity, enthalpy, and entropy.
Thermal stability refers to the ability of a substance or material to maintain its physical and chemical properties at elevated temperatures. It is an important characteristic in various fields, including materials science, chemistry, and engineering, as it determines how a material behaves when exposed to heat. Key aspects of thermal stability include: 1. **Decomposition**: Many compounds will break down or decompose when exposed to high temperatures. A material with high thermal stability will not decompose until it reaches the decomposition temperature.
Kleptothermy is a behavioral adaptation observed in certain animal species, where individuals steal heat from other animals to regulate their body temperature. This phenomenon typically occurs in cold environments where maintaining warmth is crucial for survival. Animals that exhibit kleptothermy might huddle together or share burrows, allowing them to benefit from the heat generated by their companions. By relying on the body heat of other individuals instead of generating their own, these animals can conserve energy and reduce their metabolic demands.
The phonograph, invented by Thomas Edison in 1877, is an early device for playing back recorded sound. It works by capturing sound vibrations through a diaphragm that creates grooves on a rotating cylinder or disk. The most common early form of the phonograph played sound from a cylindrical medium, while later developments led to the creation of flat discs known as records.
Tuvan throat singing, also known as "höömii," is a traditional vocal technique that originates from the Tuva Republic in Siberia, Russia. This unique form of singing allows a single performer to produce multiple pitches simultaneously, creating a harmonious sound that includes distinct overtones. The singer typically produces a fundamental pitch while simultaneously resonating higher harmonics, resulting in a rich, layered auditory experience.

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