Heavy water Updated +Created
International System of Units Updated +Created
The key is to define only the minimum number of measures: if you define more definitions become over constrained and could be inconsistent.
Learning the modern SI is also a great way to learn some interesting Physics.
Programming paradigm Updated +Created
Quaternary Updated +Created
Relational database Updated +Created
Binary tree Updated +Created
Enzyme Updated +Created
For an initial concrete example, consider e. Coli K-12 MG1655 gene thrA.
Video 1.
How Enzymes Work by RCSBProteinDataBank (2017)
Source. Shows in detail how aconitase catalyses the citrate to isocitrate reaction in the citric acid cycle.
Invertible matrix Updated +Created
The set of all invertible matrices forms a group: the general linear group with matrix multiplication. Non-invertible matrices don't form a group due to the lack of inverse.
ipinf.ru Updated +Created
Type system Updated +Created
Vim Updated +Created
Before we get a decent open source integrated development environment, what else can you do?
But also perfect for small one-off files when you don't have the patience to setup said IDE.
vim's defaults are atrocious for the 21st century! Vundle is reasonable as an ad-hoc package manager, but it can't set fixed versions of packages:
Rigid body dynamics simulator Updated +Created
Ripples by ripples Updated +Created
A Baidu Baike page: baike.baidu.hk/item/層層水瀾/12386243 mentions that the score was published in 1970 by Tao Yimo (陶一陌) in a eponymous score book.
Video 1.
Ripples by ripples performed by Wu Li on the guzheng
. Source. Peformer's Chinese name: 吳莉.
River Cam Updated +Created
Video game difficulty Updated +Created
Water Margin Updated +Created
Talks about rebellion of the oppressed (and bandits), and therefore has been controversial throughout the many Chinese dictatorships.
The book is based on real events surrounding 12th century rebel leader Song Jiang during the Song dynasty.
It is also interesting that Mao Zedong was apparently a fan of the novel, although he had to hide that to some extent due to the controversial nature of the material, which could be said to instigate rebellion.
The incredible popularity of the novel can also be seen by the large number of paintings of it found in the Summer Palace.
This is a good novel. It appeals to Ciro Santilli's sensibilities of rebelling against unfairness, and in particular about people who are at the margin of society (at the river margin) doing so. Tax the rich BTW.
It also has always made Ciro quite curious how such novels are not used as a way to inspire people to rebel against the Chinese Communist Party.
Full text uploads of Chinese versions:
Wave equation solver Updated +Created
This section talks about solvers/simulators dedicated solving the wave equation. Of course, any serious solver will likely be able to solve a wider range of PDE, so this section contains mostly fun toys. For more serious stuff see: Section "PDE solver".
JavaScript toy solvers:
Wave function collapse Updated +Created
Similar to quantum jump in the Bohr model, but for the Schrödinger equation.
The idea the the wave function of a small observed system collapses "obviously" cannot be the full physical truth, only a very useful approximation of reality.
Because then are are hard pressed to determine the boundary between what collapses and what doesn't, and there isn't such a boundary, as everything is interacting, including the observer.
The many-worlds interpretation is an elegant explanation for this. Though it does feel a bit sad and superfluous.
Wayback Machine rate limit Updated +Created
archive.org/details/toomanyrequests_20191110 says 15 archives / minute, but apparently aslo 15 retrievals per minutes on Wikipedia, after which 5 min blacklist. After that, you start getting some 429s, and after that, server refuses to connect at al.
CDX: no limits apparently, they might just throttle you? Made 10k requets on bash loop and was going fine. But not that if you get blacklisted by create/fetch requests blacklist, server fails to connect here as well.

There are unlisted articles, also show them or only show them.