Fodor's lemma is a result in set theory that is often used in the context of infinite combinatorics and descriptive set theory. It is named after the Hungarian mathematician Géza Fodor, who introduced it. **Statement of Fodor's Lemma:** Let \( X \) be a set and let \( \kappa \) be an infinite cardinal.
The Thurston norm is a mathematical concept in the field of low-dimensional topology, particularly in the study of 3-manifolds. It provides a way to assign a "norm" to elements of the second homology group \( H_2(M; \mathbb{R}) \) of a 3-manifold \( M \). This norm is associated with the concept of surface representations in the manifold and is used to measure the complexity of surfaces that can be embedded into the manifold.
The Afshar experiment is a thought experiment and a physical experiment designed to test principles of quantum mechanics, particularly focusing on the wave-particle duality and the concept of complementarity. It was proposed by Iranian physicist Shahriar Afshar in the early 2000s. The experiment is a variant of the well-known double-slit experiment.
AgniKul Cosmos is a private aerospace startup based in India that focuses on developing small satellite launch vehicles. Founded in 2017, the company aims to provide affordable and flexible launch services for small satellites, catering to the growing demand for satellite deployment in various sectors, including telecommunications, earth observation, and scientific research. One of AgniKul's notable developments is the Agnibaan rocket, which is designed to be a fully customizable launch vehicle capable of delivering small payloads into orbit.
The number 174 is an integer that comes after 173 and before 175. It can be expressed in various ways: - **In Roman numerals**: 174 is written as CLXXIV. - **In binary**: 174 is represented as 10101110. - **In hexadecimal**: It is represented as AE.
Albert I, Prince of Monaco (1848–1922) was the sovereign prince of Monaco from 1889 until his death in 1922. He is known for his significant contributions to the principality during his reign, particularly in promoting scientific exploration and research, as well as advancing Monaco's status on the international stage. Albert I was a passionate oceanographer and made notable strides in marine science. He funded and undertook numerous oceanographic expeditions, contributing to the understanding of marine environments.
Albert Nasibulin is a scientist known for his work in the field of nanotechnology and materials science, particularly in the research and development of carbon-based materials such as graphene and carbon nanotubes. He has contributed to the understanding of the properties, applications, and synthesis of these materials, which have significant implications in various industries, including electronics, energy storage, and biotechnology. Nasibulin’s work often involves exploring the potential applications of carbon nanomaterials in cutting-edge technologies.
Aleksandr Khinchin (often spelled Khinchinskii) was a prominent Russian mathematician known for his contributions to various areas of mathematics, particularly in probability theory, number theory, and mathematical statistics. He was born on March 19, 1894, and passed away on December 31, 1959.
Galina Kurlyandskaya is a notable Russian mathematician, recognized for her contributions to mathematical logic, particularly in model theory, set theory, and combinatorial aspects of logic. She has been influential in advancing the field and has published numerous papers and works related to her areas of expertise.
Poly(pentafluorophenyl acrylate) is a polymer derived from the polymerization of pentafluorophenyl acrylate, which is an acrylate monomer containing a pentafluorophenyl group. The "pentafluorophenyl" refers to a phenyl ring (a six-carbon aromatic ring) that has five of its hydrogen atoms replaced with fluorine atoms.
Alison Etheridge is a prominent British mathematician known for her contributions to the fields of probability theory and mathematical biology. She has particularly worked on stochastic processes and their applications, including evolutionary biology and population dynamics. Etheridge has published numerous papers in reputable journals and has held academic positions, contributing to research and education in mathematics.
The Alliance for the Union of Romanians (AUR, or Alianța pentru Unirea Românilor in Romanian) is a political party in Romania. It was founded in December 2019 and has positioned itself as a nationalist and conservative party, focusing on promoting Romanian identity, culture, and unity. The party has gained attention for its anti-immigration stance, advocacy for traditional family values, and critiques of the European Union's policies.
Pondcrete is a type of material used in the construction of ponds and water features. It is a specialized concrete formulation designed to be waterproof and durable in aquatic environments. Pondcrete often contains additives that enhance its resistance to water permeation and biological growth, making it suitable for landscaping and garden ponds. In practical terms, Pondcrete can be used to create custom-shaped pond liners, walls, or other structures that need to withstand water exposure while providing a solid and stable base.
In engineering, particularly in the context of software development and project management, "alpha strike" typically refers to an early-stage focus on delivering a minimum viable product (MVP) or a foundational version of a product. It emphasizes rapidly building and testing a product to gather feedback, iterate, and make improvements. The term can also be used in other engineering disciplines to denote an initial phase of a project where essential components are developed to evaluate feasibility, performance, or integration.
"American public speakers" generally refers to individuals in the United States who engage in the art of public speaking, which can encompass various forms of communication such as speeches, presentations, motivational talks, and lectures. This group can include politicians, activists, educators, authors, business leaders, and motivational speakers. Some noteworthy American public speakers include: 1. **Martin Luther King Jr.** – Known for his powerful speeches advocating for civil rights and social justice.
The amplitude damping channel is a type of quantum channel that models a common form of quantum noise. It represents a particular kind of decoherence that can occur in quantum systems, especially relevant to quantum computing and quantum information theory. In more technical terms, the amplitude damping channel describes the process by which a quantum state behaves similarly to the way a dissipative system loses energy.
Andrey Muchnik is not widely known in public discourse, and there could be multiple individuals with that name.
In finance, **time consistency** refers to the concept that an individual's or a decision-maker's preferences and plans regarding future actions should remain consistent over time. This concept has implications for financial decision-making, investment strategies, and policy formulation. Here are a few key points regarding time consistency: 1. **Expectation and Future Actions**: A time-consistent decision maker will make plans today that they will want to stick to in the future.
Trend type forecasting is a method used to predict future values based on the historical trend of data points over time. This approach is widely utilized in various fields, including economics, finance, sales, and production, to inform decision-making and strategic planning. Here are some key characteristics of trend-type forecasts: 1. **Identification of Trends**: Trend forecasts focus on recognizing underlying patterns in historical data. These trends can be upward, downward, or stable over time.
Frateschi is a brand known for producing model trains and accessories, particularly in the scale of 1:87 (HO scale) and 1:160 (N scale). The company, originally from Brazil, specializes in various types of model railway products, including locomotives, rolling stock, and scenic elements, catering to hobbyists and collectors within the model railroading community.

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