Interactive Linear Algebra by Margalit and Rabinoff Updated 2025-07-16
Intercontinental ballistic missile Updated 2025-07-16
Missileers by BBC (2000)
Source. Documentary about American ICBM crews working on the Francis. E. Warren Air Force Base. Wiki mentions that there are 3 main sites in the USA, and plainshumanities.unl.edu/encyclopedia/doc/egp.ii.042 suggests all/most of them are in the Great Plains area. They operate a Minuteman system, which as of 2021 is the only nuclear ICBM system in the USA.
Good documentary, shows well the day-to-day life of the operator, including outside of the work site.
- youtu.be/w1tMx27Q4O0?t=1390 they drive 100 miles to get to work. They do 8 alerts per month.
- youtu.be/w1tMx27Q4O0?t=1473 the actual missiles are a few miles away from the control center, scattered in a few different locations
- youtu.be/w1tMx27Q4O0?t=1619 they have a television in there at least. Presumably a pre-recorded selection.
Logistics support management by USAF
. Source. Shows logistic operations behind the American ICBM system of the time. Reuploaded to showcase the IBM 705 system used to track parts, notably the usage of a punch cards. Phanerozoic Updated 2025-07-16
The term "visible life" refers to multicellular from before people knew there was life in the proterozoic.
Internal and spacetime symmetries Updated 2025-07-16
The different only shows up for field, not with particles. For fields, there are two types of changes that we can make that can keep the Lagrangian unchanged as mentioned at Physics from Symmetry by Jakob Schwichtenberg (2015) chapter "4.5.2 Noether's Theorem for Field Theories - Spacetime":
- spacetime symmetry: act with the Poincaré group on the Four-vector spacetime inputs of the field itself, i.e. transforming into
- internal symmetry: act on the output of the field, i.e.:
From the spacetime theory alone, we can derive the Lagrangian for the free theories for each spin:Then the internal symmetries are what add the interaction part of the Lagrangian, which then completes the Standard Model Lagrangian.
Internal combustion engine Updated 2025-07-16
International Computers Limited Updated 2025-07-16
International Standard Music Number Updated 2025-07-16
Why was this so rarely used as of 2020s compared to ISBNs? It would have been perfect for helping find obscure records from Chinese traditional music and Indian classical music!
Internet company Updated 2025-07-16
IntoUniversity Updated 2025-07-16
Investigations on the theory of the Brownian movement by Einstein (1905) Updated 2025-07-16
Is AES quantum resistant? Updated 2025-07-16
2020-so-far yes, Grover's algorithm would only effectively reduce key sizes by half:
but there isn't a mathematical proof either.
ISBN Updated 2025-07-16
Phaser hello world Updated 2025-07-16
- phaser/hello.html: a minimal hello world adapted from web.archive.org/web/20230323212804/https://phaser.io/tutorials/getting-started-phaser3/part5. Not an actual game strictly speaking though, just shows the phaser logo bouncing around the screen.
- phaser/hello-game.html: an actually hello world game where you have to collect stars and avoid bombs.Based on labs.phaser.io/index.html?dir=games/firstgame/&q=:
- finished version: labs.phaser.io/view.html?src=src/games/firstgame/part10.js
- corresponding tutorial: web.archive.org/web/20230323210501/https://phaser.io/tutorials/making-your-first-phaser-3-game/part10.
PhD Comics Updated 2025-07-16
Is the MacOS kernel open source? Updated 2025-07-16
Iterative algorithm Updated 2025-07-16
Iterative post-order with two stacks Updated 2025-07-16
It is hard for complex organisms to evolve because longer DNA means longer replication time Updated 2025-07-16
Because DNA replication is a key limiting factor of bacterial replication time, such organisms are therefore strongly incentivized to have very minimal DNAs.
Power, Sex, Suicide by Nick Lane (2006) 7 "Why bacteria are simple" page 169 puts this nicely:
Bacteria replicate at colossal speed. [...] In two days, the mass of exponentially doubling E. coli would be 2664 times larger than the mass of the Earth.Luckily this does not happen, and the reason is that bacteria are normally half starved. They swiftly consume all available food, whereupon their growth is limited once again by the lack of nutrients. Most bacteria spend most of their lives in stasis, waiting for a meal. Nonetheless, the speed at which bacteria do mobilize themselves to replicate upon feeding illustrates the overwhelming strength of the selection pressures at work.
It is not possible to see stars outside of the Milky Way by naked eye Updated 2025-07-16
Photomultiplier tube Updated 2025-07-16
Can be used to detect single photons.
Richard Feynman likes them, he describes the tube at Richard Feynman Quantum Electrodynamics Lecture at University of Auckland (1979) at one point.
It uses the photoelectric effect multiple times to produce a chain reaction. In particular, as mentioned at youtu.be/5V8VCFkAd0A?t=74 from Video 1. "Using a Photomultiplier to Detect single photons by Huygens Optics" this means that the device has a lowest sensitive light frequency, beyond which photons don't have enough energy to eject any electrons.
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