Wally Smith is a mathematician known for his contributions to the field of mathematics, particularly in the areas of combinatorial design and finite geometry. He has been involved in various mathematical research, teaching, and outreach activities. Smith's work often intersects with topics such as graph theory and coding theory. However, specific details about his contributions or achievements may not be widely documented in mainstream academic literature.
Boundary layers refer to a thin region of fluid (liquid or gas) that is affected by the presence of a solid surface, such as the surface of a wing, a pipe wall, or any other boundary where the fluid dynamics are influenced by that surface. This concept is crucial in the field of fluid mechanics and is particularly important in the study of aerodynamics and hydrodynamics. The boundary layer typically forms when a fluid flows over a surface.
The Boy or Girl paradox is a thought experiment in probability that involves a seemingly counterintuitive scenario regarding gender. The classic version goes like this: A family has two children. We know that at least one of the children is a boy. What is the probability that both children are boys? Intuitively, many people might think the probability is 1/2, as there are two equally possible scenarios: either the children are (boy, boy) or (boy, girl).
For this sub-case, we can define the Lie algebra of a Lie group as the set of all matrices such that for all :
If we fix a given and vary , we obtain a subgroup of . This type of subgroup is known as a one parameter subgroup.
The immediate question is then if every element of can be reached in a unique way (i.e. is the exponential map a bijection). By looking at the matrix logarithm however we conclude that this is not the case for real matrices, but it is for complex matrices.
TODO example it can be seen that the Lie algebra is not closed matrix multiplication, even though the corresponding group is by definition. But it is closed under the Lie bracket operation.
Symplectic group by Ciro Santilli 40 Updated 2025-07-16
Intuition, please? Example? mathoverflow.net/questions/278641/intuition-for-symplectic-groups The key motivation seems to be related to Hamiltonian mechanics. The two arguments of the bilinear form correspond to each set of variables in Hamiltonian mechanics: the generalized positions and generalized momentums, which appear in the same number each.
Seems to be set of matrices that preserve a skew-symmetric bilinear form, which is comparable to the orthogonal group, which preserves a symmetric bilinear form. More precisely, the orthogonal group has:
and its generalization the indefinite orthogonal group has:
where S is symmetric. So for the symplectic group we have matrices Y such as:
where A is antisymmetric. This is explained at: www.ucl.ac.uk/~ucahad0/7302_handout_13.pdf They also explain there that unlike as in the analogous orthogonal group, that definition ends up excluding determinant -1 automatically.
Therefore, just like the special orthogonal group, the symplectic group is also a subgroup of the special linear group.
Caller ID spoofing is the technique of artificially manipulating the phone number that appears on the recipient's caller ID display. This can be done for a variety of reasons, both legitimate and illegitimate. ### How It Works When a call is made, the phone network typically transmits the calling party's number, which the receiving party sees on their caller ID.
Carl August von Schmidt (1822–1892) was a German architect best known for his significant contributions to the architectural landscape of the 19th century, particularly in Germany. His work encompassed a variety of building types, including churches, civic buildings, and residential structures. He often utilized elements of the Neoclassical and Historicist styles, which were popular during his time.
Trouton's rule is a principle in physical chemistry that provides an estimate for the entropy of vaporization of a liquid. It states that the entropy of vaporization (\( \Delta S_{vap} \)) of many liquids at their normal boiling points is approximately equal to a constant value, which is about 88 to 100 J/mol·K. This rule holds true for a variety of organic liquids, particularly those that are non-polar or weakly polar.
Cather Simpson is a renowned physicist and a professor known for her work in ultrafast optics and photonics. She has conducted significant research in the field of laser science and its applications, particularly in studying light-matter interactions on extremely short timescales. In addition to her scientific contributions, Cather Simpson is recognized for her commitment to science communication and education, aiming to inspire the next generation of scientists.
Athanase Dupré is a notable figure in the field of French art, particularly recognized for his contributions as a painter and artist in the 19th century. He is often associated with the Barbizon School, which emphasized naturalism and landscape painting. His work is characterized by a focus on the beauty of nature and the depiction of rural life.
"Causality" is a book by Judea Pearl, published in 2000, that presents a comprehensive analysis of causal reasoning and its implications in various fields such as statistics, artificial intelligence, and philosophy. Pearl, a prominent figure in the field of artificial intelligence, introduces a framework for understanding causation that goes beyond traditional correlation-based approaches. In the book, Pearl discusses the importance of distinguishing between correlation and causation, providing tools and methodologies for reasoning about causality.
The term "Centered World" might refer to various concepts depending on the context in which it is used. Without more context, it's difficult to provide a definitive answer, as "Centered World" doesn't correspond to a widely recognized concept in fields like psychology, sociology, philosophy, or geography. However, here are a few potential interpretations of the term: 1. **Philosophical or Psychological Context**: It could refer to a state of mental or emotional equilibrium.
Public transport by mode refers to the various types of transportation systems available for public use, categorized based on the mode of travel. Here’s an overview of the primary modes of public transport: 1. **Buses:** - Buses are a common mode of public transport that operate on fixed routes and schedules. They can serve cities, towns, and rural areas and are often cost-effective and accessible.
The Čech-to-derived functor spectral sequence is a tool in homological algebra and sheaf theory that relates Čech cohomology to derived functors, particularly sheaf cohomology. This spectral sequence emerges in contexts where one is interested in understanding the relationship between local properties, codified by Čech cohomology, and global properties captured by derived functors like the derived functors of sheaf cohomology. ### Overview of the Components Involved 1.
Puerto Rico, as a territory of the United States, primarily uses the imperial system of measurement, which includes units such as inches, feet, and pounds. This is consistent with the measurements used in the mainland U.S. However, the metric system is also widely recognized and used, particularly in scientific, educational, and medical contexts. In everyday life, Puerto Ricans will commonly express distances in miles, height in feet and inches, and weights in pounds.

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
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