YBC 7289 is an ancient Babylonian clay tablet that contains a cuneiform inscription, which is considered one of the earliest known examples of mathematical problem-solving. The tablet is dated to around 1800 BC and it is part of the collection of the Yale Babylonian Collection, housed at Yale University.
As of my last knowledge update in October 2021, there was no widely recognized product or service known as "Ubersketch." It’s possible that it could refer to a variety of concepts, such as a design tool, a service, or even an app that may have emerged after that date.
A "spat" is a unit of angular measurement that is used primarily in fields such as astronomy and navigation. It is defined as \(\frac{1}{3600}\) of a degree, which means that there are 3600 spats in one degree.
Standardized moments are statistical measures that help describe the shape and characteristics of a probability distribution, particularly in terms of its central tendency and variability. They are derived from the moments of a distribution, which are mathematically defined as expectations of powers of deviations from the mean. Standardized moments are typically defined in relation to the distribution's mean and standard deviation.
The term "trisected perimeter point" typically refers to a concept in geometry related to the division of a polygon's perimeter into three equal segments or divisions. In the context of a triangle, for example, the trisected perimeter points would be the points along the perimeter that divide it into three equal parts. To understand this concept better: 1. Calculate the total perimeter of a triangle (or polygon). 2. Find the length of one-third of the perimeter.
Campbell's theorem is a result in differential geometry that pertains to the geometry of a Euclidean space and the properties of certain curves and surfaces within it. Specifically, it deals with the concept of the Frenet frame and the curvature of curves. In its essence, Campbell's theorem states that for a certain class of curves in Euclidean space, there exists a correspondence between curvature and torsion.
Castelnuovo's contraction theorem is a result in algebraic geometry, specifically dealing with the properties of smooth projective varieties. The theorem is part of the study of the behavior of certain types of morphisms between algebraic varieties, particularly in the context of contraction maps in the context of the minimal model program (MMP).
The Fold-and-Cut theorem is a result in computational geometry and combinatorial geometry that deals with the problem of folding paper to achieve a desired cut. Specifically, it states that any shape that can be formed by a straight cut through a folded piece of paper can be realized by an appropriate folding of the paper beforehand.
Soddy's hexlet is a configuration in geometry involving three circles that are tangent to each other in a specific way. Named after the British chemist Frederick Soddy, who explored this arrangement in connection with the theory of circles, Soddy's hexlet refers to the construction of two smaller circles that are tangent to three larger circles, along with two additional larger circles that touch the three originals.
Glide reflection is a type of geometric transformation that combines two basic transformations: a translation and a reflection. It can be described in the following steps: 1. **Reflection**: An object is first reflected over a line (in two dimensions) or a plane (in three dimensions). This means that every point of the object is mapped to a corresponding point on the opposite side of the line or plane at an equal distance from it.
The Standard Conjectures on algebraic cycles are a set of conjectures in algebraic geometry that relate to the study of algebraic cycles and their properties, particularly in the context of algebraic varieties over a field. The conjectures were primarily formulated by Pierre Deligne, Alexander Grothendieck, and others in the mid-20th century.
Skydrol is a brand of hydraulic fluid used primarily in aviation and aerospace applications. It is a phosphate ester-based fluid known for its fire-resistant properties and stability under extreme temperatures. Skydrol is formulated to meet specific military and aviation standards, making it suitable for use in a variety of aircraft hydraulic systems.
The Supergolden ratio, often denoted by the symbol \( \xi \) or \( \Phi_s \), is a mathematical concept that generalizes the golden ratio. It is defined as the positive root of the polynomial equation \( x^3 - x - 1 = 0 \). The value of the Supergolden ratio is approximately \( 1.8392867552 \).
The Klein quadric, also known as the Klein surface, is a remarkable geometric object in the field of algebraic geometry and topology. It is represented as a certain kind of algebraic variety, specifically a projective quadric surface in projective 3-space.
The Projective Orthogonal Group, often denoted as \( P\text{O}(n) \), is a group that arises in the context of projective geometry and linear algebra. It is closely related to the orthogonal group and the projective space. Here's a breakdown of the definitions and concepts involved: 1. **Orthogonal Group**: The orthogonal group \( O(n) \) consists of all \( n \times n \) orthogonal matrices.
A border tripoint, also known as a tri-junction or tri-point, is a geographical point where the borders of three distinct regions, countries, or administrative divisions meet. This point serves as a significant landmark and is often of interest both politically and geographically. For example, a well-known border tripoint is the area where the borders of three countries converge, such as the point where the borders of France, Belgium, and Luxembourg meet.
The Riemann sphere is a model for visualizing complex numbers and their geometric properties in a compact form. It is named after the German mathematician Bernhard Riemann. The Riemann sphere is essentially a way of extending the complex plane by adding a point at infinity, allowing for a more complete understanding of complex functions, including those that have poles or essential singularities.
The term "Border States" typically refers to the slave states that did not secede from the Union during the American Civil War. These states were situated on the border between the North (the Union) and the South (the Confederacy). The five Border States are: 1. **Delaware** 2. **Kentucky** 3. **Maryland** 4. **Missouri** 5.
An aerospace manufacturer is a company or organization that designs, develops, and produces aircraft, spacecraft, satellites, and related components or systems. The aerospace manufacturing industry encompasses a wide range of activities, including: 1. **Design and Engineering**: Creating blueprints and specifications for aerospace products, often involving advanced simulations and modeling techniques. 2. **Production**: Fabricating parts and assembling complete aircraft or spacecraft. This may involve advanced materials, precision machining, and various manufacturing techniques.

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