Codomain by Ciro Santilli 37 Updated 2025-07-16
Vs: image: the codomain is the set that the function might reach.
The image is the exact set that it actually reaches.
E.g. the function:
could have:
Note that the definition of the codomain is somewhat arbitrary, e.g. could as well technically have codomain:
even though it will obviously never reach any value in .
The exact image is in general therefore harder to characterize.
Mechanics by Ciro Santilli 37 Updated 2025-07-16
This section is more precisely about classical mechanics.
Point particle by Ciro Santilli 37 Updated 2025-07-16
This idealization does not seems to be possible at all in the context of Maxwell's equations with pointlike particles.
This paper appears to calculate the Schrödinger equation solution for the hydrogen atom.
TODO is this the original paper on the Schrödinger equation?
Published on Annalen der Physik in 1926.
Open access in German at: onlinelibrary.wiley.com/doi/10.1002/andp.19263840404 which gives volume 384, Issue 4, Pages 361-376. Kudos to Wiley for that. E.g. Nature did not have similar policies as of 2023.
This paper may have fallen into the public domain in the US in 2022! On the Internet Archive we can see scans of the journal that contains it at: ia903403.us.archive.org/29/items/sim_annalen-der-physik_1926_79_contents/sim_annalen-der-physik_1926_79_contents.pdf. Ciro Santilli extracted just the paper to: commons.wikimedia.org/w/index.php?title=File%3AQuantisierung_als_Eigenwertproblem.pdf. It is not as well processed as the Wiley one, but it is of 100% guaranteed clean public domain provenance! TODO: hmmm, it may be public domain in the USA but not Germany, where 70 years after author deaths rules, and Schrodinger died in 1961, so it may be up to 2031 in that country... messy stuff. There's also the question of wether copyright is was tranferred to AdP at publication or not.
Contains formulas such as the Schrödinger equation solution for the hydrogen atom (1''):
where:
  • In order for there to be numerical agreement, must have the value
  • , are the charge and mass of the electron
Infinity (1996 film) by Ciro Santilli 37 Updated 2025-07-16
Good film, it feels quite realistic.
It is a shame that they tried to include some particularly interesting stories but didn't have the time to develop them, e.g. Feynman explaining to the high school interns what they were actually doing. These are referred to only in passing, and likely won't mean anything to someone who hasn't read the book.
The film settings are particularly good, and give what feels like an authentic view of the times. Particularly memorable are the Indian caves shown the film. TODO name? Possibly Puye Cliff Dwellings. Puye apparently appears prominently up on another film about Los Alamos: The Atomic city (1952). It is relatively close to Los Alamos, about 30 km away.
The title is presumably a reference to infinities in quantum field theory? Or just to the infinity of love etc.? But anyways, the infinities in quantum field theory theory come to mind if you are into this kind of stuff and is sad because that work started after the war.
https://upload.wikimedia.org/wikipedia/en/4/46/Infinity_film_poster.jpg
Video 1.
Infinity Trailer (1996)
Source.
The most important ones are:
Other super important ones:
Lu Zhishen by Ciro Santilli 37 Updated 2025-07-16
Early on, he's usually called by others as Major Lu (魯提轄).
His original name is Lu Da 魯達
He then receives the Buddhist name Zhishen (智深, profound wisdom) during conversion.

Pinned article: Introduction to the OurBigBook Project

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