Topics Top articles New articles Updated articles Top users New users New discussions Top discussions New comments+ New article
The Neurokernel Project aims to build an open software platform for the emulation of the entire brain of the fruit fly Drosophila melanogaster on multiple Graphics Processing Units (GPUs).
Once you have crated something awesome, you have to advertise it, otherwise no one will ever find it.
This means:
- whenever you walk into a classroom, give students a link to the materialThen ask them if they want to talk about anything.Then leave the classroom and go produce more good material instead of wasting your time there :-)
- whenever someone asks as question on an online forum, answer it, and link to the section of your material that also answers that question.The material will answer many of their future questions.
- after you've done something awesome, Google possible relevant keywords that should hit it.This will lead you to other websites that talk about the same content.Then, leave comments on those pages linking to your stuff, or email the authors of those pages.It is borderline spam, but if the subject is closely related, it is a win for everyone.
Eventually, people will find you on the front page of Google searches, and then you will know that you've truly made something useful.
A Jackdaw is a type of crow: en.wikipedia.org/wiki/Western_jackdaw
Considered one of the 10 famous Chaozhou music pieces TODO list.
Was also adapted by Liu Baoshan (1937-1997) as a pipa song. Ciro Santilli prefers the pipa version.
Bibliography:
Jackdaw Playing With Water performed by Xu Lingzi on the guzheng at the Wiener Musikverein
. Source. Jackdaw Playing With Water performed by Lin Shicheng on the pipa
. Source. Ciro Santilli once visited the chemistry department of a world leading university, and the chemists there were obsessed with NMR. They had small benchtop NMR machines. They had larger machines. They had a room full of huge machines. They had them in corridors and on desk tops. Chemists really love that stuff. More precisely, these are used for NMR spectroscopy, which helps identify what a sample is made of.
Basically measures the concentration of certain isotopes in a region of space.
Introduction to NMR by Allery Chemistry
. Source. - only works with an odd number of nucleons
- apply strong magnetic field, this separates the energy of up and down spins. Most spins align with field.
- send radio waves into sample to make nucleons go to upper energy level. We can see that the energy difference is small since we are talking about radio waves, low frequency.
- when nucleon goes back down, it re-emits radio waves, and we detect that. TODO: how do we not get that confused with the input wave, which is presumably at the same frequency? It appears to send pulses, and then wait for the response.
How to Prepare and Run a NMR Sample by University of Bath (2017)
Source. This is a more direct howto, cool to see. Uses a Bruker Corporation 300. They have a robotic arm add-on. Shows spectrum on computer screen at the end. Shame no molecule identification after that!Proton Nuclear Magnetic Resonance by Royal Society Of Chemistry (2008)
Source. This video has the merit of showing real equipment usage, including sample preparation.
Says clearly that NMR is the most important way to identify organic compounds.
- youtu.be/uNM801B9Y84?t=41 lists some of the most common targets, including hydrogen and carbon-13
- youtu.be/uNM801B9Y84?t=124 ethanol example
- youtu.be/uNM801B9Y84?t=251 they use solvents where all protium is replaced by deuterium to not affect results. Genius.
- youtu.be/uNM801B9Y84?t=354 usually they do 16 radio wave pulses
The most minimal hello world with gnuplot visualization!!! stackoverflow.com/questions/11175694/bullet-physics-simplest-collision-example/36987063#36987063
gnuplot plot of the y position of a sphere bouncing on a plane simulated in Bullet Physics
. Source. From: What is the simplest collision example possible in a Bullet Physics simulation? Physics education needs more focus on understanding experiments and their history by 
Ciro Santilli 35 Updated 2025-01-22 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-01-22 +Created 1970-01-01This is the only way to truly understand and appreciate the subject.
Understanding the experiments gets intimately entangled with basically learning the history of physics, which is extremely beneficial as also highlighted by Ron Maimon, related: there is value in tutorials written by early pioneers of the field.
"How we know" is a basically more fundamental point than "what we know" in the natural sciences.
In the Surely You're Joking, Mr. Feynman chapter O Americano, Outra Vez! Richard Feynman describes his experience teaching in Brazil in the early 1950s, and how everything was memorized, without any explanation of the experiments or that the theory has some relationship to the real world!
Although things have improved considerably since in Brazil, Ciro still feels that some areas of physics are still taught without enough experiments described upfront. Notably, ironically, quantum field theory, which is where Feynman himself worked.
Feynman gave huge importance to understanding and explaining experiments, as can also be seen on Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979).
Inward Bound by Abraham Pais (1988) page 282 shows how this can be generalized from the Maxwell-Boltzmann distribution
2022-02: Kiea Barlast floor lamp: www.ikea.com/gb/en/p/barlast-floor-lamp-black-white-50437810 Bulb: LED bulb E27 globe opal white.
Sampling from a complex wavefunction by Ciro Santilli 35 Updated 2025-01-22 +Created 1970-01-01
Ciro Santilli 35 Updated 2025-01-22 +Created 1970-01-01A series of systems usually derived from the International System of Units that are more convenient for certain applications.
Search a lot first, and only create your own when you can't find something that suits you.
Someone else has already written everything you can come up with.
And if you do find something useful that you want to modify, propose your modifications to the author: they can also be useful to them and others.
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:
- 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-calculusArticles 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 - 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.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
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.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. - Internal cross file references done right:
- Infinitely deep tables of contents:
Figure 6. Dynamic article tree with infinitely deep table of contents.Live URL: ourbigbook.com/cirosantilli/chordateDescendant 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