Poincaré sphere by Ciro Santilli 40 Updated 2025-07-16
A more photon-specific version of the Bloch sphere.
In it, each of the six sides has a clear and simple to understand photon polarization state, either of:
The sphere clearly suggests for example that a rotational or diagonal polarizations are the combination of left/right with the correct phase. This is clearly explained at: Video "Quantum Mechanics 9b - Photon Spin and Schrodinger's Cat II by ViaScience (2013)".
Video 1.
Fabry Perot Interferometer by JFC UCL (2016)
Source. Description only, reasonable animations. Considers the case of two nearby beam splitters.
Video 2.
Fabry-Perot Introduction by Williams College Physics (2020)
Source.
Shows a working device. Confocal optical cavity, one of the mirrors scans back and forward moved by a piezoelectric motor, this is called a "scanning Fabry-Perot interferometer".
Does not produce an interference pattern, only an on/off blob, which is then fed into an oscilloscope for analysis. The oscilloscope shows both the mirror displacement (which is given by a voltage) and the light detector output.
Video 3.
Aligning a Scanning Fabry-Perot Interferometer by University of South Florida (2016)
Source. Very detailed, and shows of some nice equipment and techniques.
Optical fibre by Ciro Santilli 40 Updated 2025-07-16
Video 1.
The Story of Light by Bell Labs (2015)
Source. A ultra quick and Bell Labs focused overview of the development of optical fibre.
Higgs boson by Ciro Santilli 40 Updated 2025-07-16
Initially there were mathematical reasons why people suspected that all boson needed to have 0 mass as is the case for photons a gluons, see Goldstone's theorem.
However, experiments showed that the W boson and the Z boson both has large non-zero masses.
So people started theorizing some hack that would fix up the equations, and they came up with the higgs mechanism.
Pocket Disc is a lightweight, portable, and flexible flying disc designed for recreational play. It is typically made from a fabric material that allows it to be easily thrown and caught, making it suitable for various outdoor activities such as disc golf, beach games, or casual tossing in the park. One of its standout features is its soft texture, which helps prevent injuries while playing, making it a popular choice for families and children.
A reverberation room is a specialized space designed to create a controlled acoustic environment where sound can reflect off walls, ceilings, and floors, simulating the acoustic behavior of various environments.
Chris Brink may refer to different individuals or contexts, but without additional specificity, it's difficult to provide a precise answer. One prominent figure named Chris Brink is a South African academic known for his work in higher education, including his role as a vice-chancellor at the University of the Free State in South Africa.
Vaalputs is a waste disposal site located in South Africa, specifically in the Northern Cape province. It serves as a national facility for the disposal of low- and intermediate-level radioactive waste. The site is managed by the National Radioactive Waste Disposal Institute (NRWDI), and its primary purpose is to ensure the safe and secure disposal of radioactive materials generated from various sources, including medical, industrial, and research facilities.
Thyspunt is a site located along the coast of the Eastern Cape province in South Africa, near the town of Jeffreys Bay. It has garnered significant attention due to proposals for the development of a nuclear power station by the South African government and the state-owned power utility, Eskom. The Thyspunt site is part of a broader plan to address South Africa's energy needs through the expansion of nuclear energy as a means of providing reliable and stable power.
SOUD can refer to different concepts depending on the context. One common interpretation is that it might be an acronym or a specific term in fields such as technology, finance, or a particular organization. However, as of my last knowledge update in October 2023, there isn't a widely recognized definition or meaning for "SOUD" that stands out universally.
Aleksandr Nekrasov can refer to different individuals, depending on the context. However, one prominent figure associated with that name is a Russian artist and political figure, notably involved in various political movements and activities.
Elbrus refers to a line of microprocessors developed in Russia, designed for general-purpose computing. These processors are named after Mount Elbrus, the highest peak in Europe, located in the Caucasus Mountains. The Elbrus processors are part of a series of models that have evolved over the years, with the aim of providing high-performance computing capabilities, particularly for tasks that are critical in the fields of government, defense, and scientific research.
The Fast Universal Digital Computer M-2 (FUDC M-2) is a type of computer that was developed in the Soviet Union during the 1960s. It is part of a series of digital computers that were designed to perform various computational tasks, particularly in scientific and engineering applications. The FUDC series was notable for its relatively high speed and versatility, aiming to serve the needs of research institutions and industries.
Kičevo Municipality is a municipality located in the western part of North Macedonia. Its administrative center is the town of Kičevo. This region is known for its rich cultural heritage, beautiful landscapes, and historical significance. The area is characterized by a mix of urban and rural settings, with several smaller villages surrounding the town. Kičevo has a diverse population, and the region is home to various ethnic communities, which contribute to its cultural diversity.

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