Spectral line Updated 2025-07-16
A single line in the emission spectrum.
Has been the leading motivation of the development of quantum mechanics, all the way from the:
- Schrödinger equation: major lines predicted, including Zeeman effect, but not finer line splits like fine structure
- Dirac equation: explains fine structure 2p spin split due to electron spin/orbit interactions, but not Lamb shift
- quantum electrodynamics: explains Lamb shift
- hyperfine structure: due to electron/nucleus spin interactions, offers a window into nuclear spin
SQL SERIALIZABLE isolation level Updated 2025-07-16
The European Union is a failure Updated 2025-07-16
It hasn't achieved anything beyond the Schengen zone.
Related:
- having more than one natural language is bad for the world
- Video "The Euro Has Never Been More Problematic by Yanis Varoufakis (2018)" youtu.be/cCA68U3P_Z8?t=433 mentions a quote attributed to Gandhi, although Quote Investigator does not think that the attribution evidence is strong:to which Ghandi answers:
What do you think of Western civilization?
Finite special general linear group Updated 2025-07-16
Just like for the finite general linear group, the definition of special also works for finite fields, where 1 is the multiplicative identity!
Note that the definition of orthogonal group may not have such a clear finite analogue on the other hand.
Mathematics illustration software Updated 2025-07-16
Survey by Ciro Santilli: math.stackexchange.com/questions/1985/software-for-drawing-geometry-diagrams/3938216#3938216
Many plotting software can be used to create mathematics illustrations. They just tend to have more data-oriented rather than explanatory-oriented output.
Open source standard cell library Updated 2025-07-16
Open source ones:
- www.quora.com/Are-there-good-open-source-standard-cell-libraries-to-learn-IC-synthesis-with-EDA-tools/answer/Ciro-Santilli Are there good open source standard cell libraries to learn IC synthesis with EDA tools?
Pivot (strategy) Updated 2025-07-16
Applications of the Fourier series Updated 2025-07-16
How to value startup shares Updated 2025-07-16
The Final Encyclopedia (Paul Allen) Updated 2025-07-16
The Google Story Chapter 21. A Virtual Library mentions that Paul Allen was interested in trying to create something like the "Final Encyclopedia" from this book. This is somewhat the same motivation for Google Books and Google's activities more broadly, as shown in their organise the world's information mission statement.
C7.4 Oxford physics course Updated 2025-07-16
- qubit.guide/ HTML version od the book.
- github.com/thosgood/qubit.guide. Source code. Written in Bookdown.
- www.arturekert.org/iqis links to the lectures: www.youtube.com/@ArturEkert/playlists Well done in splitting those videos up!
- zhenyucai.com/post/intro_to_qi/
Interesting presentation cycle at Merton BTW: www.arturekert.org/teaching/merton
Cadmium Updated 2025-07-16
Calculus of variations Updated 2025-07-16
Calculus of variations is the field that searches for maxima and minima of Functionals, rather than the more elementary case of functions from to .
Heavyside step function Updated 2025-07-16
Induced pluripotent stem cell Updated 2025-07-16
Microwave Updated 2025-07-16
Microwave production and detection is incredibly important in many modern applications:
- telecommunications, e.g. being used in
- Wi-Fi
- satellite communicationsyoutu.be/EYovBJR6l5U?list=PL-_93BVApb58SXL-BCv4rVHL-8GuC2WGb&t=27 from CuriousMarc comments on some piece of Apollo equipment they were restoring/reversing:Ah, Ciro Santilli really wishes he knew what that meant more precisely. Sounds so cool!
These are the boxes that brought you voice, data and live TV from the moon, and should be early masterpieces of microwave electronics, the blackest of black arts in analog electronics.
- 4G and other cellular network standards
- radar. As an example, 1965 Nobel Prize in Physics laureate Julian Schwinger did some notable work in the area in World War II, while most other physicists went to the Manhattan Project instead.This is well highlighted in QED and the men who made itby Silvan Schweber (1994). Designing the cavity wasn't easy. One of the key initial experiments of quantum electrodynamics, the Lamb-Retherford experiment from 1947, fundamental for modern physics, was a direct consequence of post-radar research by physicists who started to apply wartime developments to their scientific search.Wikipedia also mentions en.wikipedia.org/w/index.php?title=Microwave&oldid=1093188913#Radar_2:
The first modern silicon and germanium diodes were developed as microwave detectors in the 1930s, and the principles of semiconductor physics learned during their development led to semiconductor electronics after the war.
- microwave is the natural frequency of several important Atomic, Molecular and Optical Physics phenomena, and has been used extensively in quantum computing applications, including completely different types of quantum computer type:Likely part of the appeal of microwaves is that they are non-ionizing, so you don't destroy stuff. But at the same time, they are much more compatible with atomic scale energies than radio waves, which have way way too little energy.
- trapped ion quantum computer; Video "Trapping Ions for Quantum Computing by Diana Craik (2019)"
- superconducting quantum computer; e.g. this Junior Microwave Design Engineer job accouncement from Alice&Bob: archive.ph/wip/4wGPJ
The Fourier transform is a bijection in Updated 2025-07-16
As mentioned at Section "Plancherel theorem", some people call this part of Plancherel theorem, while others say it is just a corollary.
This is an important fact in quantum mechanics, since it is because of this that it makes sense to talk about position and momentum space as two dual representations of the wave function that contain the exact same amount of information.
Theft Updated 2025-07-16
The Great Sage, Heaven's Equal (Strange Tales from a Chinese Studio story) Updated 2025-07-16
There are unlisted articles, also show them or only show them.