Sal Khan Updated 2025-07-16
Like Jimmy Wales, he used to work in finance and then quit. What is it with those successful e-learning people??
Sass (stylesheet language) Updated 2025-07-16
The more of their syntax gets merged into mainline Cascading Style Sheets, the better the world will be.
Leo Szilard Updated 2025-07-16
Leo Szilard: The Genius Behind the Bomb
. Source. 1992. TODO an external link to the production? Producers credited at end: Helen Weiss and Alain Jehlen. As indicated at: archive.org/details/TheGeniusBehindtheBomb it was apparently produced by WGBH, public radio station from Boston. Level: Asian Updated 2025-07-16
This is true. The level of competition in university entry exams in Asia in insane in the early 21st century compared to the West.
This is actually both good and bad. Good because it selects some very good exam passers. And bad because it selects some very good exam passers.
Library classification Updated 2025-07-16
Life difficulty level meme Updated 2025-07-16
Planned obsolescence Updated 2025-07-16
2019 cell phones are glued together with adhesive, which makes them impossible to repair them unless you have a heat gun, spend hours and hours learning and planning, and accept the risk of breaking the screen
Repairability scores: www.ifixit.com/smartphone-repairability
If you take a phone less than 300 dollars to a repair shop in the first world, they will say: I've never repaired this crap, and likely for the price of the repair you should just buy a new one, and so to the trash goes the old one, polluting the planet, and in comes a new one, enriching the manufacturer further.
Oh, there is some 2017 EU action actually: (archive) www.europarl.europa.eu/news/en/press-room/20170629IPR78633/making-consumer-products-more-durable-and-easier-to-repair
Pleistocene Updated 2025-07-16
Agriculture is not the official definition of the age. But it is good enough. Likely related to the official end of glaciations thing.
Second law of thermodynamics Updated 2025-07-16
Subtle is the Lord by Abraham Pais (1982) chapter 4 "Entropy and Probability" mentions well how Boltzmann first thought that the second law was an actual base physical law of the universe while he was calculating numerical stuff for it, including as late as 1872.
But then he saw an argument by Johann Joseph Loschmidt that given the time reversibility of classical mechanics, and because they were thinking of atoms as classical balls as in the kinetic theory of gases, then there always exist a valid physical state where entropy decreases, by just reversing the direction of time and all particle speeds.
So from this he understood that the second law can only be probabilistic, and not a fundamental law of physics, which he published clearly in 1877.
Second quantization Updated 2025-07-16
Second quantization also appears to be useful not only for relativistic quantum mechanics, but also for condensed matter physics. The reason is that the basis idea is to use the number occupation basis. This basis is:
- convenient for quantum field theory because of particle creation and annihilation changes the number of particles all the time
- convenient for condensed matter physics because there you have a gazillion particles occupying entire energy bands
Bibliography:
- www.youtube.com/watch?v=MVqOfEYzwFY "How to Visualize Quantum Field Theory" by ZAP Physics (2020). Has 1D simulations on a circle. Starts towards the right direction, but is a bit lacking unfortunately, could go deeper.
Secrets (Allan Holdsworth album) Updated 2025-07-16
Secrets Allan Holdsworth album
. Source. Linear operator Updated 2025-07-16
Examples:
- a 2x2 matrix can represent a linear map from to , so which is a linear operator
- the derivative is a linear map from to , so which is also a linear operator
Line (geometry) Updated 2025-07-16
Lines through origin model of the real projective plane Updated 2025-07-16
This is the standard model.
List of AI games Updated 2025-07-16
List of anatomical systems Updated 2025-07-16
List of books Updated 2025-11-05
List of nuclear weapons Updated 2025-07-16
List of Stack Overflow users Updated 2025-09-09
List of version control systems Updated 2025-07-16
There are unlisted articles, also show them or only show them.

