Search for extraterrestrial intelligence by Ciro Santilli 35 Updated +Created
Search engine by Ciro Santilli 35 Updated +Created
Scorewriter by Ciro Santilli 35 Updated +Created
Basically a GUI music editor where you can specifically see and export classical music notation instead of tablature-style notation.
Best open source one found so far as of 2020: MuseScore.
Probability distribution by Ciro Santilli 35 Updated +Created
Science fiction author by Ciro Santilli 35 Updated +Created
Finite field by Ciro Santilli 35 Updated +Created
A convenient notation for the elements of of prime order is to use integers, e.g. for we could write:
which makes it clear what is the additive inverse of each element, although sometimes a notation starting from 0 is also used:
For fields of prime order, regular modular arithmetic works as the field operation.
For non-prime order, we see that modular arithmetic does not work because the divisors have no inverse. E.g. at order 6, 2 and 3 have no inverse, e.g. for 2:
we see that things wrap around perfecly, and 1 is never reached.
For non-prime prime power orders however, we can find a way, see finite field of non-prime order.
Video 1.
Finite fields made easy by Randell Heyman (2015)
Source. Good introduction with examples
Distributive property by Ciro Santilli 35 Updated +Created
One of the defining properties of algebraic structure with two operations such as ring and field:
This property shows how the two operations interact.
Science communication by Ciro Santilli 35 Updated +Created
Schrödinger picture example: quantum harmonic oscillator by Ciro Santilli 35 Updated +Created
TODO: use the results from the quantum harmonic oscillator solution to precisely illustrate the discussion at Schrödinger picture with a concrete example.
Scanning transmission electron microscopy by Ciro Santilli 35 Updated +Created
Video 1.
50,000,000x Magnification by AlphaPhoenix (2022)
Source.
Scanning electron microscope by Ciro Santilli 35 Updated +Created
Video 1.
The Scanning Electron Microscope by MaterialsScience2000 (2014)
Source. Shows operation of the microscope really well. Seems too easy, there must have been some extra setup before however. Impressed by how fast the image update, it is basically instantaneous. Produced by Prof. Dr.-Ing. Rainer Schwab from the Karlsruhe University of Applied Sciences.
Video 2.
Mosquito Eye Scanning Electron Microscope Zoom by Mathew Tizard (2005)
Source. Video description mentions is a composite video. Why can't you do it in one shot?
Lecture 1 by Ciro Santilli 35 Updated +Created
Course outline given:
Non-relativistic QFT is a limit of relativistic QFT, and can be used to describe for example condensed matter physics systems at very low temperature. But it is still very hard to make accurate measurements even in those experiments.
Defines "relativistic" as: "the Lagrangian is symmetric under the Poincaré group".
Mentions that "QFT is hard" because (a finite list follows???):
There are no nontrivial finite-dimensional unitary representations of the Poincaré group.
But I guess that if you fully understand what that means precisely, QTF won't be too hard for you!
Notably, this is stark contrast with rotation symmetry groups (SO(3)) which appears in space rotations present in non-relativistic quantum mechanics.
SARS-CoV-2 N protein by Ciro Santilli 35 Updated +Created
Sand mandala by Ciro Santilli 35 Updated +Created
Embryonics by species by Ciro Santilli 35 Updated +Created
Sandia National Laboratories by Ciro Santilli 35 Updated +Created

Pinned article: ourbigbook/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 5. . 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.
  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