The lexicographic order topology on the unit square, which we denote as \( [0, 1] \times [0, 1] \), is based on an ordering of the points in the unit square. In this topology, we define a way to compare points \((x_1, y_1)\) and \((x_2, y_2)\) in the square using the lexicographic order, similar to how words are ordered in a dictionary.
In general topology, various examples illustrate different concepts and properties. Here is a list of significant examples that are commonly discussed: 1. **Discrete Topology**: In this topology, every subset is open. For any set \(X\), the discrete topology on \(X\) consists of all possible subsets of \(X\).
In topology, a **Moore space** is a particular type of topological space that satisfies certain separation axioms and conditions related to bases for open sets. More specifically, a Moore space is a topological space that is a *second-countable* and *reasonable* space.
In the context of mathematics, particularly in topology, an **open set** refers to a fundamental concept that helps define various properties of spaces. Here's a more detailed explanation: 1. **Definition**: A set \( U \) in a topological space \( X \) is called an open set if, for every point \( x \) in \( U \), there exists a neighborhood around \( x \) that is entirely contained within \( U \).
A **proximity space** is a type of mathematical structure used in topology that generalizes the concept of proximity, or nearness, between sets. While traditional topological spaces focus on the open sets, proximity spaces provide a way to directly express the notion of how close two subsets of a given set are to each other.
In topology, a **second-countable space** is a type of topological space that has a specific property related to its basis. A topological space \(X\) is said to be second-countable if it has a countable basis for its topology. More formally, a **basis** for a topology on a set \(X\) is a collection of open sets such that every open set in the topology can be expressed as a union of sets from this basis.
Zorich's theorem is a result in the field of dynamical systems, specifically concerning the behavior of interval exchange transformations (IETs). An interval exchange transformation is a way of rearranging an interval by cutting it into subintervals and then permuting these intervals. Zorich's theorem states that for a generic interval exchange transformation with sufficiently smooth (e.g., piecewise continuous) functions, the trajectory of almost every point under the IET will exhibit unique ergodicity.
Geodesy organizations are institutions or associations dedicated to the study and application of geodesy, which is the science of measuring and understanding the Earth's geometric shape, orientation in space, and gravity field. These organizations often focus on various aspects such as satellite positioning, GPS technology, mapping, and earth observation. Geodesy organizations can vary widely in their scope and activities.
Surveying and geodesy are both essential fields in mapping and understanding the Earth's surface, and they rely heavily on markers for precision and accuracy. ### Surveying Surveying is the science and art of determining the relative positions of points on the Earth's surface. It involves measuring distances, angles, and elevations to create maps, establish land boundaries, and set out construction projects.
The annual cycle of sea level height refers to the seasonal fluctuations in sea level that occur due to a variety of factors, including temperature, precipitation, and wind patterns. Here are some key components that contribute to this cycle: 1. **Thermal Expansion**: Sea water expands as it warms. During warmer months, typically around summer in each hemisphere, sea surface temperatures rise, leading to thermal expansion and a slight increase in sea level.
A gravity anomaly is a measurement of the difference between the observed gravitational field of the Earth at a specific location and the expected gravitational field, which is typically calculated based on a model of the Earth's shape and mass distribution. Gravity anomalies can provide valuable insights into geological structures and variations in subsurface density. They are instrumental in fields like geophysics, geology, and natural resource exploration.
ED50, or the "effective dose 50," is a term commonly used in pharmacology and toxicology to describe the dose of a drug or substance that produces a therapeutic effect in 50% of a population or experimental subjects. It is a key measure in assessing the efficacy of a drug and helps to understand its potency and the dose-response relationship.
The term "geographical pole" refers to the two points on the Earth's surface where its axis of rotation intersects the surface. These points are known as the North Pole and the South Pole. 1. **North Pole**: Located at 90 degrees north latitude, the North Pole is the northernmost point on Earth. It lies in the Arctic Ocean and is covered by sea ice for much of the year.
The Geodetic Reference System 1980 (GRS80) is a geodetic reference system that defines the shape and size of the Earth and serves as the basis for creating the reference frame associated with the Global Positioning System (GPS) and other geospatial applications. It was established in 1980 as an update to earlier geodetic systems.
Geographical distance refers to the physical space between two points on Earth's surface. It is usually measured in units such as kilometers or miles. Geographical distance can be calculated using a variety of methods, including: 1. **Euclidean Distance**: This method measures the shortest straight-line distance between two points, often used in a Cartesian coordinate system.
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!
Intro to OurBigBook
. Source. We have two killer features:
- 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-calculusArticles 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/derivativeVideo 2. OurBigBook Web topics demo. Source. - 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.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
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. - Infinitely deep tables of contents:
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





