Hermitian matrix by Ciro Santilli 35 Updated +Created
Hidden Answers by Ciro Santilli 35 Updated +Created
www.reddit.com/r/onions/comments/sfquss/hidden_answers_is_back/ gives pbqttnffb5sh6ckgnz4f5by55w25gd6tuw5f5qcctmnyk62eyhgx6rad.onion which is Dead Janary 2024
Adenine by Ciro Santilli 35 Updated +Created
Structure of the ribosome by Ciro Santilli 35 Updated +Created
High Mountain and Flowing Water by Ciro Santilli 35 Updated +Created
Composed by Bo Ya for the guqin.
But there is an awesome guzheng adaptation which is perhaps better known in modern times, partly because it is not as long/slow. TODO origin.
Video 1.
High Mountain and Flowing Water performed on the guzheng by Xiang SiHua (2000)
Source. Performer Chinese name: 項斯華
History of the World Wide Web by Ciro Santilli 35 Updated +Created
Video 1.
Why web tech is like this by Steve Sanderson (2022)
Source.
Hollerith tabulating machine by Ciro Santilli 35 Updated +Created
Video 1.
The 1890 US Census and the history of punchcard computing by Stand-up Maths (2020)
Source. It was basically a counting machine! Shows a reconstruction at the Computer History Museum.
PCR verification with gel electrophoresis by Ciro Santilli 35 Updated +Created
Biology experiments are hard, and so they go wrong, a lot.
For this reason, it is wise to verify that certain steps are correct whenever possible.
And so this is the first thing we did on the second day!
Gel electrophoresis separates molecules by their charge-to-mass ratio. It is one of those ultra common lab procedures!
This allows us to determine how long are the DNA fragments present in our solution.
Since we know that we amplified the 16S regions which we know the rough size of (there might be a bit of variability across species, but not that much), we were expecting to see a big band at that size.
And that is exactly what we saw!
First we had to prepare the gel, put the gel comb, and pipette the samples into wells present in the gel:
Figure 1.
Gel electrophoresis insert comb.
Source.
Figure 2.
Gel electrophoresis top view with wells visible.
Source.
Figure 3.
Gel electrophoresis pipette sample into wells.
Source.
To see the DNA, we added ethidium bromide to the samples, which is a substance that that both binds to DNA and is fluorescent.
Because it interacts heavily with DNA, ethidium bromide is a mutagen, and the biology people sure did treat the dedicated electrophoresis bench area with respect! Figure 4. "Gel electrophoresis dedicated bench area to prevent ethidium bromide contamination.".
Figure 4.
Gel electrophoresis dedicated bench area to prevent ethidium bromide contamination.
Source.
Figure 5.
Gel electrophoresis dedicated waste bin for centrifuge tubes and pipette tips contaminated with ethidium bromide.
Source.
The UV transilluminator we used to shoot UV light into the gel was the Fisher Scientific UVP LM-26E Benchtop 2UV Transilluminator. The fluorescent substance then emitted a light we can see.
As barely seen at Figure 8. "Fischer Scientific UVP LM-26E Benchtop 2UV Transilluminator illuminated gel." due to bad photo quality due to lack of light, there is one strong green line, which compared to the ladder matches our expected 16S length. What we saw it with the naked eyes was very clear however.
Figure 6.
Fischer Scientific UVP LM-26E Benchtop 2UV Transilluminator
. Source.
Figure 7.
Fischer Scientific UVP LM-26E Benchtop 2UV Transilluminator loading gel.
Source.
Figure 8.
Fischer Scientific UVP LM-26E Benchtop 2UV Transilluminator illuminated gel.
Source.
Homotopy by Ciro Santilli 35 Updated +Created
Horrible Horrendous Terrible Tremendous by Ciro Santilli 35 Updated +Created
They might have shut down, but they still have the cutest name! And they've made some cute inscriptions too, see: HHTT
How can a chemical substance be unstable but not flammable? by Ciro Santilli 35 Updated +Created
I can't believe there isn't a YouTube video comparing various substances for each flammability and instability ratings, this would be a huge hit.
How to decide if an ORM is good? by Ciro Santilli 35 Updated +Created
How to decide if an ORM is decent? Just try to replicate every SQL query from nodejs/sequelize/raw/many_to_many.js on PostgreSQL and SQLite.
There is only a very finite number of possible reasonable queries on a two table many to many relationship with a join table. A decent ORM has to be able to do them all.
If it can do all those queries, then the ORM can actually do a good subset of SQL and is decent. If not, it can't, and this will make you suffer. E.g. Sequelize v5 is such an ORM that makes you suffer.
The next thing to check are transactions.
Basically, all of those come up if you try to implement a blog hello world world such as gothinkster/realworld correctly, i.e. without unnecessary inefficiencies due to your ORM on top of underlying SQL, and dealing with concurrency.
How to diagnose a genius by Wilhelm Ostwald (1909) by Ciro Santilli 35 Updated +Created
From the abstract:
Much money, his student went on to say, is spent by various Governments in attempting to discover those people whose thorough education may be expected to bring in a return of value to the State, and the question how best to discover latent genius is an eminently practical one. After cogitation, Prof. Ostwald came to the conclusion that it is those students who cannot be kept on the rails - that is, who are not contented with methodical teaching - who have within them the seeds of genius
Ciro Santilli couldn't agree more... notably students must have a flexible choice of what to learn.
The first/only way Ciro could find was with ampy: stackoverflow.com/questions/74150782/how-to-run-a-micropython-host-script-file-on-the-raspbery-pi-pico-from-the-host/74150783#74150783 That just worked and it worked perfectly!
python3 -m pip install --user adafruit-ampy
ampy --port /dev/ttyACM0 run blink.py
TODO: possible with rshell?

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