Dirac-von Neumann axioms Updated 2025-07-16
This is basically what became the dominant formulation as of 2020 (and much earlier), and so we just call it the "mathematical formulation of quantum mechanics".
Discogs Updated 2025-07-16
The IMDb of music! They actually have a reputation system apparently. And sneaked in a vinyl marketplace as well.
The website name sounds like play on words: disc + hog, with hog in the sense "memory-hog", i.e. something that consumes all your computer's memory.
Video 1.
Everything you need to know about discogs.com by Vinyl for Miles (2019)
Source. Gives a good overview of the website.
Video 2.
AnalogPlanet Interviews Discogs Founder Kevin Lewandowski (2019)
Source.
Chinese musical instrument Updated 2025-07-16
The main four instruments are undoubtedly:but there is also amazing content on others which must not be missed, including:
Video 1.
25 musical instruments OF China by Learning Music Hub
. Source. Great video, covers all the most important ones briefly with examples of varying relevance.
Video 2.
A beginner’s guide to Chinese musical instruments by SCMP
. Source. 2024. Terrible editing, way to hard to see instrument name.
Video 3.
Chinese vs Western musical instrument battle scene from Our Shining Days
. Source. A bit cheap, but it has some value.
C. elegans nervous system Updated 2025-07-16
Video 1.
Interview with John White by MRC Laboratory of Molecular Biology (2023)
. Source.
Symplectic group Updated 2025-07-16
Intuition, please? Example? mathoverflow.net/questions/278641/intuition-for-symplectic-groups The key motivation seems to be related to Hamiltonian mechanics. The two arguments of the bilinear form correspond to each set of variables in Hamiltonian mechanics: the generalized positions and generalized momentums, which appear in the same number each.
Seems to be set of matrices that preserve a skew-symmetric bilinear form, which is comparable to the orthogonal group, which preserves a symmetric bilinear form. More precisely, the orthogonal group has:
and its generalization the indefinite orthogonal group has:
where S is symmetric. So for the symplectic group we have matrices Y such as:
where A is antisymmetric. This is explained at: www.ucl.ac.uk/~ucahad0/7302_handout_13.pdf They also explain there that unlike as in the analogous orthogonal group, that definition ends up excluding determinant -1 automatically.
Therefore, just like the special orthogonal group, the symplectic group is also a subgroup of the special linear group.
The best films of all time Updated 2025-07-16
There is only a very fine difference between a very good film, and the best films of all time. Perhaps it is something to do on how epic the subject matter is? It is often very hard to tell, and switches between the categories are also possible.
Chinese traditional painting Updated 2025-07-16
Unclear legality:
Chomsky hierarchy Updated 2025-07-16
This is the classic result of formal language theory, but there is too much slack between context free and context sensitive, which is PSPACE (larger than NP!).
A good summary table that opens up each category much more can be seen e.g. at the bottom of en.wikipedia.org/wiki/Automata_theory under the summary thingy at the bottom entitled "Automata theory: formal languages and formal grammars".
Super Mario 64 Updated 2025-07-16
And as a result, adult Ciro really enjoys tool-assisted speedruns of the game.
The Man From Earth (2007) Updated 2025-07-16
Good theory of Jesus.
List of similar feeling films: www.youtube.com/watch?v=zwYwFoanrNg 11 Underrated Hard Sci-fi Movies by Marvelous Videos (2021)
TwinsUK Updated 2025-07-16
Church of England Updated 2025-07-16
Political division:
  • nominal leader: British monarch
  • toplevel arch-dioceses/provinces of Cantebury and York. One archbishop each, who is also bishop of Cantebury and York diocese
  • within provinces: one cathedral and bishop per diocese
Chu (state) Updated 2025-07-16
Slow neutron Updated 2025-07-16
Tangent space Updated 2025-07-16
TODO what's the point of it.
Bibliography:

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