PostgreSQL logging by Ciro Santilli 35 Updated +Created
Ubuntu 21.10 has a certain default level of logging by default to:
/var/log/postgresql/postgresql-13-main.log
but it does not log everything, only/mostly errors it seems.
Setting:
log_statement = 'all'
under:
/etc/postgresql/13/main/postgresql.conf
and then restarting the server:
sudo service restart postgresql
just works.
Dilution refrigerator manufacturer by Ciro Santilli 35 Updated +Created
Order of a tensor by Ciro Santilli 35 Updated +Created
has order
Potassium by Ciro Santilli 35 Updated +Created
OurBigBook CLI by Ciro Santilli 35 Updated +Created
German nuclear weapons program by Ciro Santilli 35 Updated +Created
Order (algebra) by Ciro Santilli 35 Updated +Created
The order of a algebraic structure is just its cardinality.
Sometimes, especially in the case of structures with an infinite number of elements, it is often more convenient to talk in terms of some parameter that characterizes the structure, and that parameter is usually called the degree.
Optical tweezers by Ciro Santilli 35 Updated +Created
Sample usages:
Video 1. . Source. Setup on a optical table. He drags a 1 micron ball of polystyrene immersed in water around with the laser. You look through the microscope and move the stage. Brownian motion is also clearly visible when the laster is not holding the ball.
Optical microscope by Ciro Santilli 35 Updated +Created
Definition not very nice, as it excludes X-ray crystallography, which is also photon based.
Optical fiber by Ciro Santilli 35 Updated +Created
Video 1.
The Story of Light by Bell Labs (2015)
Source. Gives some ideas of the history of fiber optics. Features: Herwig Kogelnik.
Video 3. . Source. 2008 at MIT. Theory and demonstration.
Molecular biology by Ciro Santilli 35 Updated +Created
Molecular Sciences Course of the University of São Paulo by Ciro Santilli 35 Updated +Created
A fantastic sounding full time 4-year course that any student could transfer to called that teaches various natural science topics, notably mathematics, physics, chemistry and molecular biology.
Many past students Ciro talked to however share a common frustration with the course: in the first 2 years at least, the "basic cycle", you have infinitely many courses, and no time to study, and no choice of what to study, it is only in the latter 2 years (the advanced cycle) that you get the choices.
Also, if you get low grades in a single subject, your out. And exams are useless of course.
Here's a Quora question in Portuguese about the course: pt.quora.com/Como-funciona-o-tal-do-curso-secreto-da-USP, the only decent answer so far being: pt.quora.com/Como-funciona-o-tal-do-curso-secreto-da-USP/answer/Victor-Soares-31. Very disappointing to hear.
On the advanced cycle, you have a lot of academic freedom. You are basically supposed to pick a research project with an advisor and go for it, with a small amount of mandatory course hours. Ciro was told in 2022 that you can even have advisors from other universities or industry, and that it is perfectly feasible to take courses in another university and validate the course hours later on. Fantastic!!!
Students from the entire University of São Paulo can apply to transfer to it only after joining the university, with the guarantee that they can go back to their original courses if they don't adapt to the new course, which is great!
Not doing it is one of Ciro Santilli's regrets in life, see also: don't be a pussy.
Around 2007, they were in a really shady building of the University, but when Ciro checked in 2021, they had apparently moved to a shiny new entrepreneurship-focused building. Fantastic news!!!
This place has one of the best changes of spawning the first Brazilian Nobel Prize or unicorn.
One of the Brazilians who came to École Polytechnique together with Ciro was from this course. The fact that he is one of the most intelligent people Ciro knows gave further credit to that course in his eyes.
Monero ASIC resistance by Ciro Santilli 35 Updated +Created
Googling does not lead to any commercial ASICs on sale that is not just a CPU or as efficient as certain CPUs, so perhaps they've actually manged it!
Money creation vs tax by Ciro Santilli 35 Updated +Created
To Ciro Santilli, a key observation is:
The rich are more easily able to avoid the harm than poor and middle-class people [...] they are more likely to have large amounts of non-cash assets to shield themselves from inflation.
Clearly the rich will be much, much more shielded by keeping large parts of their wealth in shares... from this point of view, it is insane to print money!!! Tax the rich instead...
Geographical division of England by Ciro Santilli 35 Updated +Created
Monty Python by Ciro Santilli 35 Updated +Created
Video 1.
How Not To Be Seen by Monty Python
. Source. This sketch is based on actual military training films such as: www.youtube.com/watch?v=URwmZq70_DU
Glucose by Ciro Santilli 35 Updated +Created
The most important on in metabolism internals, everything else gets converted to it before being processed in the .

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