A rotary valve is a type of valve that controls the flow of fluids or gases in a system by utilizing a rotating mechanism. These valves are commonly used in various applications, including engines, HVAC systems, and industrial processes. ### Key Features of Rotary Valves: 1. **Design**: Rotary valves typically consist of a cylindrical body with an internal mechanism that can rotate to open or close the flow path. The most common types of rotary valves include ball valves, butterfly valves, and plug valves.
A pseudovector, also known as an axial vector, is a type of vector in physics and mathematics that behaves differently under certain transformations compared to regular (true) vectors. Specifically, pseudovectors are associated with quantities that have an inherent sense of direction and magnitude but behave differently under parity transformations (reflections). ### Key Characteristics of Pseudovectors: 1. **Transformation Under Parity**: - True vectors (e.g.
The Zwanzig projection operator is a mathematical tool used in the field of statistical mechanics and nonequilibrium thermodynamics to derive reduced descriptions of many-body systems. Named after Robert Zwanzig, it is particularly useful for studying systems with a large number of degrees of freedom, allowing one to focus on the relevant variables while ignoring others. The basic idea behind the Zwanzig projection operator is to split the total phase space of a system into "relevant" and "irrelevant" parts.
Probabilistic models are mathematical frameworks used to represent and analyze uncertain systems or phenomena. Unlike deterministic models, which produce the same output given a specific input, probabilistic models incorporate randomness and allow for variability in outcomes. This is useful for capturing the inherent uncertainty in real-world situations. Key features of probabilistic models include: 1. **Random Variables**: These are variables whose values are determined by chance.
As of my last knowledge update in October 2021, there isn't a specific organization universally recognized as the "Statistical Modelling Society." It's possible that such an organization has been established since then, or the term may refer to a group, society, or community focused on statistical modeling techniques and applications in various fields such as data science, statistics, and machine learning.
A **factored language model** is an extension of traditional language models that allows for the incorporation of additional features or factors into the modeling of language. This approach is particularly useful in situations where there are multiple sources of variation that affect language use, such as different contexts, speaker attributes, or syntactic structures. In a standard language model, probabilities are assigned to sequences of words based on n-grams or other statistical techniques.
John Archibald Wheeler by Ciro Santilli 40 Updated 2025-07-16
Richard Feynman's mentor at Princeton University, and notable contributor to his development of quantum electrodynamics.
Worked with Niels Bohr at one point.
Web of Stories interview (1996): www.youtube.com/playlist?list=PLVV0r6CmEsFzVlqiUh95Q881umWUPjQbB. He's a bit slow, you wonder if he's going to continute or not! One wonders if it is because of age, or he's always been like that.
Teletext Ltd. is a media company that was originally known for providing teletext services in the UK. Established in the 1970s, it was one of the pioneers in delivering information to television viewers through a system that allowed access to news, sports updates, weather, and other types of information via a dedicated teletext signal. The service was widely used before the rise of the internet and digital TV. Teletext Ltd.
Murray Gell-Mann by Ciro Santilli 40 Updated 2025-07-16
The way this dude speaks. He exhales incredible intelligence!!!
In the interviews you can see that he pronounces names in all languages amazingly, making acute effort to do so, to the point of being notable. His passion for linguistics is actually mentioned on Genius: Richard Feynman and Modern Physics by James Gleick (1994).
Maybe this obsession is partly due to his name which no English speaking person knows how to pronounce from the writing.
This passion also led in part for his names to some physics terminology he worked on winning out over alternatives by his collaborators, most notably in the case of the naming of the quark.
Paul Dirac by Ciro Santilli 40 Updated 2025-07-16
Eccentric nerdy slow speaking physicist mostly based in University of Cambridge.
Created the Dirac equation, what else do you need to know?!
QED and the men who made it: Dyson, Feynman, Schwinger, and Tomonaga by Silvan Schweber (1994) chapter 1.3 "P.A.M. Dirac and the Birth of Quantum Electrodynamics" quotes Dirac saying how being at high school during World War I was an advantage, since all slightly older boys were being sent to war, and so the younger kids were made advance as fast as they could through subjects. Exactly the type of thing Ciro Santilli wants to achieve with OurBigBook.com, but without the need for a world war hopefully.
Dirac was a staunch atheist having said during the Fifth Solvay Conference (1927)[ref]:
If we are honest - and scientists have to be - we must admit that religion is a jumble of false assertions, with no basis in reality. The very idea of God is a product of the human imagination. It is quite understandable why primitive people, who were so much more exposed to the overpowering forces of nature than we are today, should have personified these forces in fear and trembling. But nowadays, when we understand so many natural processes, we have no need for such solutions. I can't for the life of me see how the postulate of an Almighty God helps us in any way. What I do see is that this assumption leads to such unproductive questions as why God allows so much misery and injustice, the exploitation of the poor by the rich and all the other horrors He might have prevented. If religion is still being taught, it is by no means because its ideas still convince us, but simply because some of us want to keep the lower classes quiet. Quiet people are much easier to govern than clamorous and dissatisfied ones. They are also much easier to exploit. Religion is a kind of opium that allows a nation to lull itself into wishful dreams and so forget the injustices that are being perpetrated against the people. Hence the close alliance between those two great political forces, the State and the Church. Both need the illusion that a kindly God rewards - in heaven if not on earth - all those who have not risen up against injustice, who have done their duty quietly and uncomplainingly. That is precisely why the honest assertion that God is a mere product of the human imagination is branded as the worst of all mortal sins.
Video 1.
Paul Dirac and the religion of mathematical beauty by Royal Society (2013)
Source.
As of my last knowledge update in October 2021, "Ten15" could refer to several different things, as it's not a widely recognized term on its own. It may refer to a brand, company, product, or initiative depending on the context. However, without additional information, it's difficult to provide a specific answer.
Signedness refers to the property of a data type that indicates whether it can represent both positive and negative values (signed) or only non-negative values (unsigned). This concept is important in computer science, particularly in programming and data representation. 1. **Signed Data Types**: A signed data type can represent both positive and negative numbers. For example, in many programming languages, an `int` (integer) type is typically signed by default.
"Presumed security" is a concept that refers to the assumption that certain systems, protocols, or environments are secure by default, often due to their design, reputation, or the ways in which they have been implemented. This presumption can lead users and organizations to believe that they do not need to take additional precautions or to scrutinize the security measures in place, potentially leading to vulnerabilities if the underlying assumptions turn out to be incorrect.
A Marsquake refers to seismic activity on the planet Mars, analogous to earthquakes on Earth. These quakes are detected and measured by instruments designed to capture vibrations in the Martian crust. NASA's InSight lander, which landed on Mars in late 2018, is equipped with a seismometer capable of detecting these seismic events.
Sednoid generally refers to a group of trans-Neptunian objects located in the outer region of the solar system, specifically in the distant area beyond Neptune. The term is primarily associated with a particular object known as 90377 Sedna, which was discovered in 2003. Sedna is notable for its highly elongated elliptical orbit, taking it far beyond the traditional boundaries of the solar system.
"Richard Robertson" could refer to multiple individuals depending on the context. Without additional details, it's challenging to provide a specific answer. Here are a few possibilities: 1. **Richard Robertson (Ice Hockey)**: A professional ice hockey player who has played in various leagues. 2. **Richard Robertson (Scottish Cricketer)**: An athlete known in the cricketing world.

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