Deuterium by Ciro Santilli 37 Updated 2025-07-16
Applications:
Griffiths' inequality is a result from statistical mechanics and probability theory, specifically relating to the behavior of certain random configurations in lattice systems. The inequality is usually stated in the context of a lattice model of statistical mechanics, notably in the study of spins or percolation. In simple terms, Griffiths' inequality provides a way to compare the probabilities of different configurations in statistical systems, particularly under conditions of positivity or negativity related to interactions among particles (or spins).
The Hard Hexagon Model is a statistical mechanics model that explores the behavior of hard hexagonal particles arranged on a two-dimensional lattice. This model is a specific case of hard particle systems, where the particles are represented as non-overlapping, rigid shapes—in this case, hexagons.
Kinetic exchange models of markets are a type of economic model that use concepts from statistical mechanics and kinetic theory to describe the behavior of markets through the interactions of agents. These models typically focus on how individual agents (such as traders or investors) make decisions about buying and selling based on their local information, interactions with other agents, and the aggregated effects of these interactions over time.
The Jordan-Wigner transformation is a mathematical technique used in quantum mechanics and condensed matter physics to map spin systems to fermionic systems. It provides a way to express operators of spin-1/2 systems (like those found in quantum spin chains) in terms of fermionic creation and annihilation operators.
The Lifson–Roig model is a theoretical framework used to describe the dynamics of polymer chains, particularly in the context of statistical mechanics and polymer physics. Developed by the physicists I. Lifson and M. Roig in the 1960s, the model provides insights into the behavior of flexible polymers or polypeptides in solution, focusing on aspects such as chain conformation and interactions.
The Maximum Term Method is a systematic approach used in the field of operations research and optimization, particularly in the context of linear programming and decision-making processes. It aims to find the solution that maximizes the minimum gain (or, inversely, minimizes the maximum loss) across possible scenarios or outcomes. Here’s a brief overview of how it works: 1. **Decision Problems**: Relevant in scenarios where a decision-maker faces uncertainty about the outcomes resulting from actions taken.
Scaled Particle Theory (SPT) is a theoretical framework used primarily in statistical mechanics and condensed matter physics to study the properties of fluids, particularly in the context of small particles or solutes interacting with a solvent. Developed in the 1960s, the theory provides a systematic way to analyze the behavior of fluids with respect to the size and interactions of particles. The main idea behind SPT is to characterize the effect of a particle's size on its interactions with the surrounding medium or solvent.
Microscopic reversibility is a principle in statistical mechanics and thermodynamics that states that the underlying microscopic processes of a system can occur in either direction, and the statistical behavior of the system remains invariant when those processes are reversed. This idea is rooted in the concept that at the molecular or atomic level, the laws of physics—particularly the laws of motion—are time-invariant, meaning they don't change if time is reversed.
In statistical mechanics, "multiplicity" refers to the number of ways a particular state or configuration can be achieved for a system of particles. It is a measure of the number of microstates corresponding to a specific macrostate. A microstate is a specific detailed configuration of a system (e.g., the positions and velocities of all particles), while a macrostate is defined by macroscopic properties such as temperature, pressure, and volume.
Order and disorder are concepts that can be applied across various fields, including physics, philosophy, sociology, and more. Here’s a brief overview of each concept: ### Order 1. **General Definition:** Order refers to a state of arrangement, organization, or structure where elements follow a certain pattern or system. In a state of order, components interact in predictable ways, leading to stability and coherence.
The National Trauma Data Bank (NTDB) is a comprehensive trauma registry in the United States that collects data on trauma-related injuries and outcomes. Established by the American College of Surgeons (ACS), the NTDB aims to improve the quality of trauma care by collecting and analyzing data from participating trauma centers across the country.

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