Anuška Ferligoj is a noted Slovene statistician and professor recognized for her contributions to the field of statistics, particularly in social science research methodology, survey methodology, and particularly in the context of multilevel modeling and psychometrics. She has been involved in academic research and has published numerous papers in her field. Furthermore, she has been influential in various professional organizations related to statistics and has played a role in promoting statistical education and research.
The Apple Tape Backup 40SC is a tape backup device that was designed for use with Macintosh computers, primarily in the late 1990s. It was part of the SCSI (Small Computer System Interface) family of products and offered a way to back up data onto magnetic tape. The "40SC" in its name indicates its storage capacity and speed—specifically, it could back up data at a rate of 40 MB per minute.
Sensitivity analysis is a powerful tool used in business to evaluate how changes in certain input variables can affect the outcome of a model or decision. Here are several applications of sensitivity analysis in a business context: 1. **Financial Modeling**: Businesses use sensitivity analysis to understand how changes in key financial assumptions (e.g., sales volume, pricing, cost of goods sold) impact profitability, cash flow, and overall financial performance.
Applied Spectroscopy Reviews is a peer-reviewed scientific journal that focuses on the application of spectroscopic techniques in various fields. It publishes reviews on the latest developments, advancements, and applications of spectroscopy in areas such as chemistry, biology, materials science, and environmental science, among others. The journal aims to provide a platform for researchers to share detailed insights into how spectroscopic methods are being utilized to solve complex problems or advance knowledge in different disciplines.
"Area code stubs" typically refer to placeholder or incomplete entries related to telephone area codes in databases, software, or telecommunications systems. These stubs may indicate that information regarding a specific area code has not been fully populated or updated in a given context. In telecommunications, area codes are numerical prefixes that designate specific geographic regions for phone numbers.
Parallel light by Ciro Santilli 40 Updated 2025-07-16
Often just called collimated light due to the collimator being the main procedure to obtain it.
However, you move very far away from the source, e.g. the Sun, you also get essentially parallel light.
Silicon photonics by Ciro Santilli 40 Updated 2025-07-16
Video 1.
Silicon Photonics: The Next Silicon Revolution? by Asianometry (2022)
Source.
Video 2.
Running Neural Networks on Meshes of Light by Asianometry (2022)
Source.
Video 3.
Silicon Photonics for Extreme Computing by Keren Bergman (2017)
Source.
Polarization of light by Ciro Santilli 40 Updated 2025-07-16
This section discusses the pre-photon understanding of the polarization of light. For the photon one see: photon polarization.
People were a bit confused when experiments started to show that light might be polarized. How could a wave that propages through a 3D homgenous material like luminiferous aether have polarization?? Light would presumably be understood to be analogous to a sound wave in 3D medium, which cannot have polarization. This was before Maxwell's equations, in the early 19th century, so there was no way to know.
Particularly cool is to see how Fresnel fully understood that light is somehow polarized, even though he did not know that it was made out of electromagnetism, clear indication of which only came with the Faraday effect in 1845.
spie.org/publications/fg05_p03_maluss_law:
At the beginning of the nineteenth century the only known way to generate polarized light was with a calcite crystal. In 1808, using a calcite crystal, Malus discovered that natural incident light became polarized when it was reflected by a glass surface, and that the light reflected close to an angle of incidence of 57° could be extinguished when viewed through the crystal. He then proposed that natural light consisted of the s- and p-polarizations, which were perpendicular to each other.
Malus' Law by Ciro Santilli 40 Updated 2025-07-16
Matches the quantum superposition probability proportional to the square law. Poor Étienne-Louis Malus, who died so much before this was found.
Given the view of the Standard Model where the electron and quarks are just completely separate matter fields, there is at first sight no clear theoretical requirement for that.
As mentioned e.g. at QED and the men who made it: Dyson, Feynman, Schwinger, and Tomonaga by Silvan Schweber (1994) chapter 1.6 "Hole theory", Dirac initially wanted to think of the holes in his hole theory as the protons, as a way to not have to postulate a new particle, the positron, and as a way to "explain" the proton in similar terms. Others however soon proposed arguments why the positron would need to have the same mass, and this idea had to be discarded.
Quantum mechanics by Ciro Santilli 40 Updated 2025-07-16
Quantum mechanics is quite a broad term. Perhaps it is best to start approaching it from the division into:
Mathematics: there are a few models of increasing precision which could all be called "quantum mechanics":
Ciro Santilli feels that the largest technological revolutions since the 1950's have been quantum related, and will continue to be for a while, from deeper understanding of chemistry and materials to quantum computing, understanding and controlling quantum systems is where the most interesting frontier of technology lies.
Fine structure by Ciro Santilli 40 Updated 2025-07-16
Split in energy levels due to interaction between electron up or down spin and the electron orbitals.
Numerically explained by the Dirac equation when solving it for the hydrogen atom, and it is one of the main triumphs of the theory.
Hydrogen line by Ciro Santilli 40 Updated 2025-07-16
21 cm is very long and very low energy, because he energy split is very small!
Compare it e.g. with the hydrogen 1-2 spectral line which is 121.6 nm!
Quantum Hall effect by Ciro Santilli 40 Updated 2025-07-16
Quantum version of the Hall effect.
As you increase the magnetic field, you can see the Hall resistance increase, but it does so in discrete steps.
Figure 1.
Hall resistance as a function of the applied magnetic field showing the Quantum Hall effect
. Source. As we can see, the blue line of the Hall resistance TODO material, temperature, etc. It is unclear if this is just
Gotta understand this because the name sounds cool. Maybe also because it is used to define the fucking ampere in the 2019 redefinition of the SI base units.
At least the experiment description itself is easy to understand. The hard part is the physical theory behind.
Video 1.
Integer and fractional quantum Hall effects by Matthew A. Grayson
. Source. Presented 2015. This dude did good.

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