A perfect totient number is a type of number related to the concept of totient functions in number theory. The totient function, denoted as \( \phi(n) \), counts the integers up to \( n \) that are coprime to \( n \).
A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself. In other words, a prime number is only divisible by 1 and the number itself, meaning it cannot be divided evenly by any other integers. For example, the numbers 2, 3, 5, 7, 11, and 13 are all prime numbers.
The number 104 is an integer that comes after 103 and before 105. It is an even number and can be factored into its prime components as \(2^3 \times 13\).
A **quasiperfect number** is a hypothetical concept in number theory. It is defined as a positive integer \( n \) for which the sum of its proper divisors (all divisors excluding the number itself) is equal to \( n + 1 \).
Wolstenholme numbers are a special sequence of natural numbers related to combinatorial mathematics and number theory. Specifically, a Wolstenholme number \(W_n\) is defined as the binomial coefficient \(\binom{2n}{n}\) for a given non-negative integer \(n\), which counts the number of ways to choose \(n\) items from a set of \(2n\) items.
Znám's problem is a concept in the field of complexity theory and computational mathematics, specifically related to the study of decision problems and their difficulty. However, there might be some confusion or less familiarity with this term in broader contexts compared to well-known problems like the P vs NP problem. Typically, problems that fall under this umbrella deal with the difficulty of certain types of mathematical functions, especially in relation to numeric functions and complexity classes.
The proof that π is irrational was first established by Johann Lambert in 1768. His proof is somewhat complex and relies on properties of continued fractions, but I can provide a high-level overview of the concepts involved in proving the irrationality of π. ### Overview of Lambert's Proof 1. **Definitions**: A number is irrational if it cannot be expressed as a fraction of two integers.
The term "History of Large Numbers" typically refers to a concept in probability and statistics rather than a specific historical narrative. It might be a misunderstanding or conflation of two distinct ideas: the "Law of Large Numbers" and the general historical context of how large numbers and probabilities have been understood throughout time.
"Top lists" typically refer to curated collections of items ranked based on specific criteria, such as popularity, quality, or relevance. These lists can cover a wide range of topics and categories, including: 1. **Entertainment:** Top movies, TV shows, songs, or books. 2. **Travel:** Top destinations, hotels, or travel experiences. 3. **Food:** Top restaurants, dishes, or recipes. 4. **Technology:** Top gadgets, apps, or software.
A list of numbers is simply a collection of numerical values arranged in a specific order. This can be presented in various formats, such as a sequence (e.g., 1, 2, 3, 4, 5), a column, or a row in a table. Lists of numbers can be finite or infinite and can include different types of numbers, such as integers, fractions, decimals, or even complex numbers.
Recycling codes are numerical or alphanumeric symbols printed on plastic products to indicate the type of plastic resin used in their manufacturing. These codes help consumers and recycling facilities identify the material composition of plastics for proper recycling and waste management. The codes are typically found in the form of a triangle made of arrows, with a number inside, ranging from 1 to 7.
Radiometry is the science of measuring optical radiation, which includes electromagnetic radiation in the visible and invisible spectrum, such as ultraviolet and infrared light. It encompasses various concepts and units related to the detection and quantification of light energy, including its intensity, power, and distribution across different wavelengths. Key terms in radiometry include: 1. **Radiant Power (or Radiant Flux)**: The total amount of energy emitted by a light source per unit time, measured in watts (W).
The Polygon experiment typically refers to a decentralized layer 2 scaling solution for Ethereum called Polygon (previously known as Matic Network). It aims to enhance the scalability and user experience of Ethereum by providing faster transaction speeds and lower fees while maintaining the security of the Ethereum network. Polygon achieves this through a variety of technologies, including Plasma chains, zk-Rollups, and Optimistic Rollups, among others.
The Pound–Rebka experiment, conducted by physicists Robert Pound and Glen A. Rebka in 1959 at Harvard University, was a pivotal experiment designed to test the predictions of Einstein's theory of general relativity, specifically the gravitational redshift effect. In essence, the gravitational redshift effect posits that light emitted from a source in a gravitational field (such as the Earth) will lose energy as it climbs out of that field.
Tests of relativistic energy and momentum involve experimental validations of the principles established by Albert Einstein's theory of relativity, particularly the relationships between energy, momentum, and mass at relativistic speeds—those close to the speed of light. ### Key Concepts 1.
Torricelli's experiment refers to a historical scientific experiment conducted by the Italian physicist Evangelista Torricelli in the 17th century (specifically, in 1643). This experiment demonstrated the principles of atmospheric pressure and led to the invention of the barometer. In Torricelli's experiment, he filled a long glass tube (approximately 1 meter in length) with mercury and then inverted the tube into a basin filled with mercury.
James L. Flanagan is a prominent figure in the field of electrical engineering, particularly known for his contributions to signal processing and telecommunications. He has authored or co-authored numerous papers and has been involved in various research projects throughout his career. Flanagan is also recognized for his work in developing algorithms and techniques that have had a significant impact on voice processing and audio signal analysis.
The Nevill Mott Medal and Prize is an award established by the Institute of Physics (IOP) in the UK to recognize outstanding contributions to the field of condensed matter physics. Named after the renowned physicist Sir Nevill Francis Mott, who was awarded the Nobel Prize in Physics in 1977, the medal and prize honor significant achievements in research and development within the discipline.
LIGPLOT is a computational tool used in molecular modeling and bioinformatics to visualize and analyze protein-ligand interactions. It generates 2D representations of protein-ligand complexes, highlighting the interactions between the ligand (often a small molecule or drug candidate) and the surrounding amino acids in the protein structure. The tool typically shows key interactions such as hydrogen bonds, hydrophobic contacts, and ionic interactions, making it easier for researchers to understand how ligands bind to their target proteins.

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