Free molecular flow refers to a regime of gas flow where the mean free path of gas molecules is much larger than the characteristic dimensions of the system through which the gas is flowing. In this condition, gas molecules travel between collisions without interacting with other molecules, often behaving as if they are in a vacuum. ### Key Characteristics of Free Molecular Flow: 1. **Mean Free Path**: This is the average distance a molecule travels between successive collisions.
The Haynes similitude principle, often referred to simply as "similitude," is a concept used primarily in fluid dynamics and related fields. It is a method that allows engineers and scientists to predict the behavior of one fluid system based on the behavior of another fluid system that is similar in certain respects. The principle is based on the idea that certain dimensionless parameters can be used to create relationships between different systems.
Rana X. Adhikari is a physicist known for his work in the fields of gravitational physics and astrophysics. He has contributed to research on gravitational waves, the study of black holes, and the dynamics of complex systems in astrophysics. Adhikari is also associated with institutions focusing on experimental physics, including work related to the Laser Interferometer Gravitational-Wave Observatory (LIGO).
The Marker-and-Cell (MAC) method is a numerical technique used to solve fluid dynamics problems, particularly for simulating incompressible flows. It was developed in the early 1970s and is widely applied in computational fluid dynamics (CFD) due to its effectiveness in handling complex boundary conditions.
The Okubo–Weiss parameter is a measure used in fluid dynamics, particularly in the study of turbulent flows, to analyze the stability and behavior of vortical structures in fluid motion. It helps to distinguish between different types of fluid flow by quantifying the balance between strain and rotation in the flow field.
Patch dynamics is a concept that arises in various fields, including physics, ecology, and systems biology. In the context of physics, it often pertains to the study of dynamic systems that can be modeled as composed of distinct "patches" or regions, each of which can have different properties or behaviors while interacting with one another.
Preferential concentration refers to a phenomenon in fluid dynamics and particle dynamics, particularly in suspensions and aerosols, where particles are not uniformly distributed throughout a flow. Instead, they tend to cluster or align preferentially in certain regions of the flow field, often in areas of low vorticity or high shear. This clustering can occur due to a variety of factors, including the interplay between the particles' inertial effects and the flow field's characteristics.
Standard sea-level conditions, often referred to as standard atmospheric conditions or International Standard Atmosphere (ISA), are a set of idealized atmospheric conditions defined for the purpose of measurement and comparison. The conditions are typically specified at sea level and are assumed to be: - **Temperature:** 15 degrees Celsius (59 degrees Fahrenheit) - **Pressure:** 1013.25 hPa (hectopascals), or 1013.25 millibars, or 29.
Transition modeling is a statistical and computational approach used to represent and analyze the changes (or transitions) between different states or conditions in a system over time. This concept is widely applied in various fields, such as economics, ecology, engineering, social sciences, and health sciences, to model dynamic processes. Here are some key aspects of transition modeling: 1. **State Space**: A transition model typically defines a finite or infinite set of states that a system can occupy.
Vortex stretching is a phenomenon in fluid dynamics that occurs in turbulent flows. It refers to the process by which a vortex line, or a thin filament of vorticity, is stretched as the surrounding fluid moves. This stretching leads to an increase in the strength and intensity of the vortex, ultimately resulting in the formation of smaller vortices and a more complex flow structure.
A generic filter is a conceptual tool or mechanism used in various fields, such as computer science, data processing, and image manipulation, to process or manipulate data in a flexible and reusable way. The term can apply in different contexts, so here are a few interpretations: 1. **In Programming**: A generic filter refers to a function or method that can take various types of input and apply a filtering operation based on specified criteria.
LEO (short for "LEO I" and "LEO II") refers to a series of early commercial computers developed by the British company J. Lyons and Co. in the 1950s. The LEO computers are historically significant because they are among the first electronic computers used for business applications. The first LEO, introduced in 1951, was capable of performing calculations for business operations such as payroll and inventory management.
"Martin's maximum" typically refers to a concept in statistical mechanics and thermodynamics related to the maximum probability distribution in the context of certain systems, or it might refer to principles in optimization or social choice theory depending on the context. However, it's not a widely recognized term. If you are referencing a specific theory, paper, or concept introduced by an individual named Martin, could you provide more context? That would help clarify your question.
Epistemic logic is a branch of modal logic that focuses on the representation and reasoning about knowledge and beliefs. In epistemic logic, modalities are used to express knowledge (often symbolized as "K") and belief (often symbolized as "B"). The basic idea is to provide a formal framework for discussing what agents know or believe about a particular situation or world.
The Arf invariant is a topological invariant associated with a smooth, oriented manifold, particularly in the context of differential topology and algebraic topology. It is especially relevant in the study of 4-manifolds and can be used to classify certain types of manifolds. The Arf invariant can be defined for a non-singular quadratic form over the field of integers modulo 2 (denoted as \(\mathbb{Z}/2\mathbb{Z}\)).
Rules of inference are logical principles that dictate valid arguments and reasoning patterns in formal logic. They allow one to derive new propositions (conclusions) from existing ones (premises) using established logical structures. These rules are fundamental in mathematical logic, computer science, and philosophy, as they provide a framework for reasoning and proof construction. Here are some common rules of inference: 1. **Modus Ponens**: If \( P \) implies \( Q \) (i.e.
A system of probability distributions refers to a collection or framework of probability distributions that describe the probabilities of different outcomes in a certain context, often involving multiple random variables or scenarios. This concept can be applied in various fields such as statistics, machine learning, economics, and decision theory. Here are several key aspects related to systems of probability distributions: 1. **Joint Distributions**: This refers to the probability distribution that covers multiple random variables simultaneously.
The decidability of first-order theories of the real numbers is a significant topic in mathematical logic, particularly concerning model theory and the foundations of mathematics. In general terms, a first-order theory consists of a set of axioms and rules for reasoning about a particular mathematical domain. When we talk about the first-order theory of the real numbers, we typically refer to the standard axioms that describe the real numbers, including properties of addition, multiplication, order, and the completeness property of the reals.
Elementary function arithmetic refers to the basic operations that can be performed on elementary functions, which are a class of functions that include well-known mathematical functions such as polynomials, exponential functions, logarithmic functions, trigonometric functions, and their inverses.
An axiomatic system is a structured framework used in mathematics and logic that consists of a set of axioms, rules of inference, and theorems. It is designed to derive conclusions and build a coherent theory based on these foundational principles. Here's a more detailed breakdown of its components: 1. **Axioms**: These are fundamental statements or propositions that are accepted as true without proof. Axioms serve as the starting points for further reasoning and the development of theorems.

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