The study of astronomy has a rich history with numerous astronomers who contributed significantly to the field across different periods. Here's a brief overview of some key astronomers categorized by historical periods: ### Ancient Astronomy (Before 500 AD) - **Claudius Ptolemy (c. 100c. 170 AD)**: Proposed the Ptolemaic system, which placed the Earth at the center of the universe. - **Aristarchus of Samos (c.
Europe cookie law by Ciro Santilli 40 Updated 2025-07-16
"Anna Becker" could refer to a number of different people or concepts, as it is a relatively common name. Without additional context, it’s difficult to provide a precise answer. It could refer to: 1. A person, such as a public figure, artist, or professional in a certain field. 2. A fictional character in a book, movie, or TV show. 3. A historical figure or someone notable in a particular domain.
Marie-Louise Saboungi is not a widely recognized individual or term as of my last update in October 2023. It could refer to a specific person or character within a niche context, such as literature, art, or academia, but additional information would be necessary to provide a definitive answer.
As of my last update in October 2021, Michael S. Montalbano does not appear to be a widely recognized public figure or historical figure. If he is a person who has gained prominence after this date, I wouldn't have that information. Could you provide more context or details regarding who he is or what field he is associated with?
A black brane is a theoretical object in the context of string theory and higher-dimensional gravity, particularly in the study of black holes and their generalizations. The term "brane" refers to higher-dimensional objects (short for "membranes") that can exist in various dimensions in string theory, while "black" indicates that the object has the properties of a black hole, such as having an event horizon and being related to the gravitational collapse of matter.
The Wilkie investment model, also known as the Wilkie Framework, is a financial model used primarily in the context of investment for life insurance companies and pension funds. Developed by actuary David Wilkie in the 1980s, this model provides a stochastic approach to forecasting asset returns and liabilities, allowing for a more nuanced evaluation of investment risks and returns over time.
The Soviet Union developed a number of microprocessors during the Cold War era, primarily for military and civilian applications. Below is a list of some notable Soviet microprocessors: 1. **K580** - A family of microprocessors based on the Intel 8080 and Zilog Z80 architecture. They were used in various computing systems.
Surface gravity refers to the gravitational acceleration experienced at the surface of a celestial body, such as a planet, moon, or star. It is a measure of how strongly the body attracts objects toward its center due to gravity. Surface gravity can be calculated using the formula: \[ g = \frac{G \cdot M}{r^2} \] Where: - \( g \) is the surface gravity, - \( G \) is the gravitational constant (\(6.
"DONE" can refer to various concepts depending on the context. Here are a few interpretations: 1. **General Term**: In everyday language, "done" means something has been completed or finished. For example, "I am done with my homework" indicates that the homework task is complete. 2. **Project Management**: In project management, "done" often relates to completed tasks or milestones. It's essential for tracking progress and ensuring that all criteria for completion have been met.
Felisa Núñez Cubero is a prominent figure in the field of social work and social intervention in Spain. She is known for her contributions to social work education, research, and practice. Her work often focuses on social welfare policies, community development, and the improvement of social services.
A Planck star is a theoretical concept in the realm of quantum gravity, particularly in the context of certain models that attempt to unify quantum mechanics and general relativity. The idea was proposed by physicist Carlo Rovelli and others as part of an effort to understand the behaviors of black holes and the nature of singularities. In simple terms, a Planck star is thought to be a hypothetical state of matter that represents the quantum gravitational state of a black hole.
Conditional probability distribution refers to the probability distribution of a subset of random variables given the values of other random variables. It allows us to understand how the probability of certain outcomes changes when we have additional information about other related variables. In mathematical terms, given two random variables \(X\) and \(Y\), the conditional probability distribution of \(Y\) given \(X\) is denoted as \(P(Y | X)\).
Gallium arsenide by Ciro Santilli 40 Updated 2025-07-16
This is apparently the most important III-V semiconductor, it seems to actually have some applications, see also: gallium arsenide vs silicon.
Oxford by Ciro Santilli 40 Updated 2025-07-16
The city clearly exists because it is in the confluence of the river Thames and the River Cherwell. In such confluences, terrain tends to be flat, and fords are also common, with crossings wide and shallow, and so it was an important crossing place.
Notably, the River Cherwell is a natural link between London and the North towards Coventry, and then Birmingham, as it, and then the Thames in which it goes into, puncture through both the Chilterns, then North Essex Downs and the Cotswolds hills. The M40.

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