A Pythagorean triple consists of three positive integers \(a\), \(b\), and \(c\) that satisfy the equation \[ a^2 + b^2 = c^2 \] In this equation, \(c\) represents the length of the hypotenuse of a right triangle, while \(a\) and \(b\) are the lengths of the other two sides.
Packing problems are a class of optimization problems that involve arranging a set of items within a defined space in the most efficient way possible. These problems often arise in various fields such as operations research, logistics, manufacturing, computer science, and graph theory. The goal is usually to maximize the utilization of space, minimize waste, or achieve an optimal configuration based on certain criteria.
The "sums of three cubes" problem refers to the mathematical challenge of expressing certain integers as the sum of three integer cubes. Specifically, the equation can be stated as: \[ n = x^3 + y^3 + z^3 \] where \( n \) is the integer we want to express, and \( x \), \( y \), and \( z \) are also integers.
Tijdeman's theorem is a result in number theory concerning the equation \( x^k - y^m = 1 \), where \( x \), \( y \) are positive integers, and \( k \), \( m \) are integers greater than or equal to 2. The theorem states that the only solutions in positive integers \( (x, y, k, m) \) to this equation occur for certain specific values.
The mathematics of rigidity is a field that studies how structures maintain their shape and resist deformation under various forces. It encompasses a wide array of concepts and applications from geometry, topology, and structural engineering, focusing on both the theoretical and practical aspects of rigidity. ### Key Concepts in the Mathematics of Rigidity: 1. **Rigidity Theory**: This area investigates the conditions under which a geometric object (like a framework or structure) is rigid.
Bellman's lost in a forest problem is a classic problem in decision theory and optimal control, named after Richard Bellman, who developed dynamic programming. The problem illustrates how to formulate and solve problems involving uncertainty, where an agent must make a series of decisions in an unknown environment. ### The Problem Statement: The scenario involves a person who finds themselves lost in a forest. The person needs to determine which direction to go to find their way back to a known point (e.g.
Close-packing of equal spheres refers to the arrangement of spheres (or balls) in such a way that they occupy the maximum possible volume relative to the total volume of the space in which they are contained. This concept is particularly important in fields such as crystallography, materials science, and solid-state physics.
The Kepler conjecture is a famous problem in the field of discrete mathematics and geometry, specifically concerning the arrangement of spheres. It was proposed by the German mathematician Johannes Kepler in 1611. The conjecture states that no arrangement of spheres (or, more generally, circles or other three-dimensional shapes) can pack more densely than the face-centered cubic (FCC) packing or the hexagonal close packing (HCP).
The Kobon triangle problem, also known as the "Kobon triangle," is a mathematical problem often discussed in the context of optimization and game theory. However, it seems there might be some confusion since the term "Kobon triangle problem" is not widely recognized in established mathematical literature up to my knowledge cutoff in October 2023.
The packing constant (or packing density) is a measure of how efficiently a shape can fill space when repeated. Different shapes have various packing constants based on how they can be arranged. Here is a list of some shapes with known packing constants: 1. **Circle**: - Packing Constant: \(\frac{\pi}{\sqrt{12}} \approx 0.9069\) for hexagonal packing 2.
In graph theory, a **regular map** is a specific type of graph that satisfies certain symmetrical properties related to vertex and face structure.
A straight skeleton is a geometric construct that is generated from a polygon by tracing its edges and creating a new structure that reflects the shape of the original polygon. It is particularly significant in computational geometry and has applications in areas such as computer graphics, urban planning, and architecture. ### Definition To create a straight skeleton for a given polygon: 1. **Starting Point**: Begin with a simple polygon, which can be convex or concave but should not have holes.
Tarski's circle-squaring problem is a famous problem in the field of geometry and mathematics, proposed by the logician and mathematician Alfred Tarski in 1925. The problem involves the task of transforming a circle into a square (or vice versa) with the same area, using only a finite number of straightedge and compass constructions. Specifically, the question is whether it is possible to construct, with traditional geometric methods (i.e.
The Erdős Distance Problem is a classic problem in combinatorial geometry that concerns the maximum number of distinct distances that can be formed by a finite set of points in the plane. Specifically, the problem is named after the Hungarian mathematician Paul Erdős. The fundamental question can be stated as follows: Given a finite set of \( n \) points in the plane, what is the maximum number of distinct distances that can be formed between pairs of points in this set?
BLAST, which stands for Basic Local Alignment Search Tool, is a bioinformatics protocol used to compare biological sequences, such as nucleotide or protein sequences. The tool is designed to identify regions of similarity between sequences, which can provide insights into the functional and evolutionary relationships among genes and proteins. Here’s a brief overview of how BLAST works: 1. **Query Sequence**: A user inputs a query sequence, which can be DNA, RNA, or protein.
"Doll stubs" typically refer to short sections of dolls' bodies, generally the arms, legs, or head, that are not fully constructed or are leftover materials from the doll-making process. In some contexts, doll stubs might also refer to incomplete or damaged dolls that can be used for repairs or as spare parts in crafting or customization projects.
Traditional dolls refer to a wide variety of dolls that are created based on cultural, historical, or regional customs. These dolls often reflect the clothing, characteristics, and traditions of specific societies or communities. They can serve various purposes, including as toys, collectors' items, or cultural symbols. Here are some key aspects of traditional dolls: 1. **Cultural Representation**: Traditional dolls often embody the attire, craftsmanship, and cultural symbols of a particular group.
"Dollmakers" can refer to a few different contexts depending on the subject matter. Here are some possibilities: 1. **Literature**: "Dollmaker" is a well-known novel by Harriett Arnow, published in 1954. The story focuses on a Kentucky woman, her family, and her struggles, set against the backdrop of her art of making doll figures.
BTRON is a computer operating system and environment that was developed in Japan as part of a broader effort to create a multimedia platform. It is part of the TRON (The Real-time Operating system Nucleus) project, which was initiated in the 1980s by Professor Ken Sakamura at the University of Tokyo. TRON aims to create an open architecture for embedded systems, allowing various devices and applications to communicate and operate seamlessly.
A "bare machine" generally refers to a physical computer or server that is devoid of any operating system or software. This term is often used in the context of virtualization, cloud computing, or hardware provisioning, where the goal is to describe the raw hardware before any software has been installed or any virtual environments have been created. In contrast to a bare machine, a fully provisioned environment would include an operating system, drivers, applications, and any necessary configurations to make the machine ready for use.

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