A cognitive map is a mental representation of spatial knowledge and the environment that an individual uses to navigate and understand their surroundings. The concept can also extend to include knowledge about relationships between objects, events, and concepts in both physical and abstract spaces. Here are some key points about cognitive maps: 1. **Spatial Awareness**: Cognitive maps help us orient ourselves in physical space, allowing us to understand the layout of places such as our home, neighborhood, or city.
The sociology of space is a subfield of sociology that examines how social relations and structures are influenced by and interact with physical spaces and environments. It encompasses the study of the ways in which spatial arrangements, such as urban and rural environments, buildings, public spaces, and even virtual spaces, shape social behaviors, interactions, and power dynamics.
A spectral sequence is a mathematical tool used in algebraic topology, homological algebra, and related fields to compute homology or cohomology groups that may be difficult to compute directly. It provides a method to systematically approximate these groups through a sequence of pages (typically indexed by integers) and associated differentials.
The Krein–Rutman theorem is an important result in functional analysis and the theory of linear operators, particularly in the study of positive operators on a Banach space. It provides conditions under which a positive compact linear operator has a dominant eigenvalue and corresponding eigenvector. This theorem has significant implications in various fields, including differential equations, fixed point theory, and mathematical biology.
A "rigged Hilbert space" (also known as a Gelfand triplet) is a mathematical concept used in quantum mechanics and functional analysis to provide a rigorous framework for dealing with the states and observables in quantum theory. The term describes a specific construction involving three spaces: a Hilbert space, a dense subspace, and its dual.
NIRSpec, or the Near Infrared Spectrograph, is a scientific instrument aboard the James Webb Space Telescope (JWST). It is designed to perform spectroscopy in the near-infrared range (0.6 to 5 microns), allowing scientists to study the composition, temperature, density, and motion of various astronomical objects, including stars, galaxies, and exoplanets.
Anders Jonas Ångström (1814–1874) was a Swedish physicist and astronomer known for his significant contributions to the field of spectroscopy and the study of light. He is best recognized for his work in measuring the wavelengths of various spectral lines and for founding the science of spectrometry. Ångström is particularly noted for his studies of the spectrum of light emitted by different elements, which laid the groundwork for modern spectroscopy.
A Computed Tomography Imaging Spectrometer (CTIS) is an advanced imaging technology that combines principles from both computed tomography (CT) and spectroscopy. It is used to capture detailed images of objects while simultaneously measuring their spectral properties, allowing for the analysis of material composition and other characteristics at different wavelengths of light. ### Key Features of CTIS: 1. **Imaging and Spectroscopy**: CTIS can produce spatial images while capturing spectral information across a range of wavelengths.
A DU spectrophotometer is a type of laboratory instrument used for measuring the absorbance or transmittance of light by a sample at specific wavelengths. The "DU" in DU spectrophotometer typically refers to a specific model series produced by Beckman Coulter, a company known for its laboratory instruments and analytical devices.
John Simons is a notable chemist known for his work in the field of electrochemistry. He is particularly recognized for his contributions to the study of ionic liquids and their applications. His research has significantly impacted areas such as physical chemistry, materials science, and even energy storage. One of his key contributions includes the development of techniques for characterizing ionic liquids, as well as understanding their properties and behaviors at the molecular level.
A superlattice is a periodic structure formed by alternating layers of two or more different materials, typically semiconductors, on a nanometer scale. These layers can be only a few nanometers thick and are engineered to create unique electronic, optical, or mechanical properties that differ from those of the individual materials. The properties of superlattices arise from quantum mechanical effects, specifically when the layer thickness approaches the electron mean free path or the de Broglie wavelength of electrons.
A comparison function is typically a function that helps in comparing two values or objects with respect to a certain criterion. In programming and algorithms, comparison functions are commonly used for sorting, searching, and determining order among data. ### Characteristics of Comparison Functions: 1. **Return Values:** - A comparison function usually returns: - A negative value if the first argument is less than the second argument. - Zero if both arguments are considered equal.
Particle statistics is a branch of statistical mechanics that deals with the distribution and behavior of particles in systems at the microscopic scale. This field is essential for understanding the properties of gases, liquids, and solids, as well as phenomena in fields such as condensed matter physics, quantum mechanics, and thermodynamics.
Lagrange stability refers to a concept in the field of dynamical systems and control theory, specifically concerning the stability of equilibria in nonlinear systems. Named after the mathematician Joseph-Louis Lagrange, this stability concept is closely related to other stability notions such as Lyapunov stability. However, the term "Lagrange stability" is not as commonly referenced as others, and may sometimes lead to some confusion or misattribution.
Linear stability refers to the analysis of the stability of equilibrium points (also known as steady states or fixed points) in dynamical systems by examining the behavior of small perturbations around those points. It is a fundamental concept in various fields such as physics, engineering, biology, and economics. When considering a dynamical system described by equations (often ordinary differential equations), the stability of an equilibrium point can be assessed by performing a linearization of the system.
The "Bob and Wheel" is a poetic device used in Middle English literature, particularly in the alliterative poetry of the 14th century. It is most famously found in the poem "Sir Gawain and the Green Knight," attributed to the Pearl Poet. The structure of the Bob and Wheel consists of two main parts: 1. **The "Bob"**: This is a short line, typically consisting of two or three stressed syllables.
Ottava rima is a form of poetry that consists of eight-line stanzas (octaves) with a specific rhyme scheme of ABABABCC. This structure is typically written in iambic pentameter, meaning each line has ten syllables with an alternating pattern of unstressed and stressed syllables.
Spin stiffness is a concept from condensed matter physics and statistical mechanics that is related to the resistance of a magnetic system to changes in its spin configuration. It's particularly important in the study of magnets, spin systems, and quantum materials. In more technical terms, spin stiffness quantifies how much energy is required to twist the spins in a magnetic system away from their preferred orientation. This can be understood in the context of both classical and quantum systems.
The Tarantula Nebula, also known as 30 Doradus, is a large emission nebula located in the Dorado constellation. It is one of the most prominent star-forming regions in our local group of galaxies and is situated within the Large Magellanic Cloud, a dwarf galaxy that orbits the Milky Way.
Multiple stars are a group of two or more stars that are physically related and bound by gravity. They can exist in several configurations, categorized primarily into binary stars, triple stars, and higher-order systems. Here are the main types of multiple stars: 1. **Binary Stars**: These systems consist of two stars orbiting around a common center of mass. They can be further classified into: - **Visual Binaries**: Stars that can be distinguished from one another through a telescope.

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