Ulam numbers are a sequence of integers that start with the numbers 1 and 2. Subsequent Ulam numbers are generated using a specific rule: each Ulam number is the smallest positive integer that can be expressed as the sum of two distinct earlier Ulam numbers in exactly one way. The sequence begins as follows: 1. The first two Ulam numbers are 1 and 2.
A Baire set is a concept from descriptive set theory, a branch of mathematical logic dealing with different levels of complexity in sets of real numbers or points in topological spaces. In the context of a Polish space, which is a separable completely metrizable topological space, Baire sets can be defined in relation to the constructible hierarchy of sets.
"Cardo" can refer to different things depending on the context: 1. **Geographical Term**: In ancient Roman towns, the "Cardo" was one of the principal streets, typically running north-south. It was an essential component of the Roman grid layout for urban planning.
In the context of lasers, "gain" refers to the amplification of light that occurs within the laser medium. More specifically, it represents the increase in the intensity of light as it travels through the gain medium, which is the material that provides the necessary optical gain for lasing to occur.
The Journal of Nanoscience and Nanotechnology is a peer-reviewed scientific journal that focuses on research in the field of nanoscience and nanotechnology. It publishes articles covering a wide range of topics related to the manipulation and application of materials at the nanoscale, typically at dimensions of 1 to 100 nanometers.
Focal length by Ciro Santilli 40 Updated 2025-07-16
If you pass parallel light.
For a biconvex spherical lens, it is given by:
where:
  • n: f nidnex
Church of England by Ciro Santilli 40 Updated 2025-07-16
Political division:
  • nominal leader: British monarch
  • toplevel arch-dioceses/provinces of Cantebury and York. One archbishop each, who is also bishop of Cantebury and York diocese
  • within provinces: one cathedral and bishop per diocese
The following things come to mind when you look into research in this area, especially the search for BB(5) which was hard but doable:
Turing machine acceleration refers to using high level understanding of specific properties of specific Turing machines to be able to simulate them much fatser than naively running the simulation as usual.
Acceleration allows one to use simulation to find infinite loops that might be very long, and would not be otherwise spotted without acceleration.
John the Baptist by Ciro Santilli 40 Updated 2025-07-16
A pre-Jesus-like figure, likely possibly a mentor or competitor with Jesus.
He would have deserved a scene in Jesus Christ Superstar (1973).

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