de Broglie relations by Ciro Santilli 40 Updated 2025-07-16
Relates particle momentum and its wavelength, or equivalently, energy and frequency.
The wavelength relation is:
but since:
the wavelength relation implies:
Particle wavelength can be for example measured very directly on a double-slit experiment.
So if we take for example electrons of different speeds, we should be able to see the diffraction pattern change accordingly.
"Discoveries" by Donal O'Ceallaigh is likely a work that delves into themes of exploration, understanding, or personal reflection, though specific details about the text, such as its content, themes, or analysis, are not widely recognized or available in mainstream literature as of my last training cut-off in October 2023.
One of the most beautiful things in mathematics are theorems of conjectures that are very simple to state and understand (e.g. for K-12, lower undergrad levels), but extremely hard to prove.
This is in contrast to conjectures in certain areas where you'd have to study for a few months just to precisely understand all the definitions and the interest of the problem statement.
David McDonald is not a widely recognized figure in the field of astronomy based on the latest information available up to October 2023. It's possible that you might be referring to a lesser-known work or a publication that has not gained significant attention.
"Discoveries" by Chad Trujillo is a work that focuses on various aspects of astronomy and planetary science, particularly through the lens of Trujillo's own discoveries and research in the field. Chad Trujillo is known for his significant contributions to the discovery of trans-Neptunian objects in the outer solar system, including dwarf planets like Haumea and Eris.
"Discoveries" by Carl W. Hergenrother is a book that focuses on various scientific and mathematical concepts, often aiming to explore and explain significant discoveries and innovations that have shaped our understanding of the world. It may cover topics in fields such as physics, chemistry, biology, and mathematics, delving into the history and context of these discoveries, as well as their implications.
Monotreme by Ciro Santilli 40 Updated 2025-07-16
The weirdest mammal clade: they lay fucking eggs. Only 5 known species alive as of 2020.
Eggs are basal: they simply didn't evolve out of what other reptiles do. From which we conclude that milk came before eggs stopped.
So this is the most basal subclade of mammals.
Etymology: means "single hole" in Greek, because like other reptiles it has a single hole for shit, pee and fucking: the cloaca.
"Discoveries" by Brett J. Gladman is a book that explores the field of astronomy and planetary science, focusing on significant discoveries and developments in our understanding of the solar system and beyond. The author, Brett J. Gladman, is a well-known astronomer who has contributed to research in areas such as planetary dynamics, near-Earth objects, and the outer solar system.
Human loss of fur by Ciro Santilli 40 Updated 2025-07-16
Video 1.
How Humans Lost Their Fur by PBS Eons (2020)
Source. Says it is linked to bipedalism to help hunting in hot weather. But could only happen fully after the invention of fire, otherwise you'd be too cold at night.
Exceptional object by Ciro Santilli 40 Updated 2025-07-16
Oh, and the dude who created the en.wikipedia.org/wiki/Exceptional_object Wikipedia page won an Oscar: www.youtube.com/watch?v=oF_FLN-TmCY, Dan Piponi, aka @sigfpe. Cool dude.
Cool examples:
Hilbert's problems by Ciro Santilli 40 Updated 2025-07-16
He's a bit overly obsessed with polynomials for the taste of modern maths, but it's still fun.

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