MAC address Updated 2025-07-16
Hardcoded and unique network addresses for every single device on Earth.
Started with 48 bits (6 bytes), usually given as 01:23:45:67:89:AB but people now encouraged to use 64-bit ones.
How they are assigned: www.quora.com/How-are-MAC-addresses-assigned Basically IEEE gives out the 3 first bytes to device manufacturers that register, this is called the organizationally unique identifier, and then each manufacturer keeps their own devices unique.
Lysozyme structure resolution (1965) Updated 2025-07-16
With X-ray crystallography by David Chilton Phillips. The second protein to be resolved fter after myoglobin, and the first enzyme.
Published at: Structure of Hen Egg-White Lysozyme: A Three-dimensional Fourier Synthesis at 2 Å Resolution (1965). The work was done while at the Davy Faraday Research Laboratory of the Royal Institution.
Phillips also published a lower resolution (6angstrom) of the enzyme-inhibitor complexes at about the same time: Structure of Some Crystalline Lysozyme-Inhibitor Complexes Determined by X-Ray Analysis At 6 Å Resolution (1965). The point of doing this is that it points out the active site of the enzyme.
Lu Zhishen uproots willow tree Updated 2025-07-16
Processor (computing) Updated 2025-07-16
Luminiferous aether Updated 2025-07-16
Can you just imagine what if luminiferous aether was one single fixed rigid body? This is apparently what Maxwell believed, Subtle is the Lord by Abraham Pais (1982) page 111 quoting his entry to Encyclopedia Britannica:Then it would provide a natural space coordinate for the entire universe!
There can be no doubt that the interplanetary and interstellar spaces are not empty but are occupied by a material substance or body, which is certainly the largest, and probably the most uniform, body of which we have any knowledge.
Luke Dashjr Updated 2025-12-25
Accounts:
- twitter.com/lukedashjr on Twitter. Status as of January 2024:This dude doesn't fuck around. Or perhaps he only fucks around. Either way.
father of 10 children
- www.linkedin.com/in/lukedashjr/ on LinkedIn
- bitcointalk.org/index.php?action=profile;u=3318 on bitcointalk.org
- www.reddit.com/user/luke-jr/
- github.com/sponsors/luke-jr
- freenode username:
luke-jr, mentioned e.g. at bitcointalk.org/index.php?topic=38007.0 from Section "Prayer wars"
Author of the prayer side of the Prayer wars.
Creator of Eligius pool Bitcoin mining pool.
According to LinkedIn he studied at the Benedictine College in Kansas.
TODO is his real birthname "Luke Dash Jr."?
Apparently he had his coins stolen in January 2023, then worth $3.5m: blog.cryptostars.is/luke-dashjr-an-original-bitcoin-developer-loses-all-his-btc-88421c395ce5p...
lujakob/nestjs-realworld-example-app SQLite port Updated 2025-07-16
Tried a quick port to SQLite to get rid of annoying local databases for development, but failed, at c1c2cc4e448b279ff083272df1ac50d20c3304faandthen:fails with:Attempt to hack it:and after that it seems to run.
npm install sqlite3 --save-dev{
"type": "sqlite",
"database": "db.sqlite3",
"entities": ["src/**/**.entity{.ts,.js}"],
"synchronize": true
}npm startDataTypeNotSupportedError: Data type "timestamp" in "ArticleEntity.created" is not supported by "sqlite" database.--- a/src/article/article.entity.ts
+++ b/src/article/article.entity.ts
@@ -20,10 +20,10 @@ export class ArticleEntity {
@Column({default: ''})
body: string;
- @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+ @Column({ default: () => "CURRENT_TIMESTAMP"})
created: Date;
- @Column({ type: 'timestamp', default: () => "CURRENT_TIMESTAMP"})
+ @Column({ default: () => "CURRENT_TIMESTAMP"})
updated: Date;I can signup and login, terrible error reporting as usual, make sure to use long enough usernames/passwords.
However, article creation fails with:
Unhandled Rejection (TypeError): Cannot read property 'slug' of undefined Program Raspberry Pi Pico W with MicroPython Updated 2025-07-26
Then there are two appraoches:
- thonny if you like clicking mouse buttons:and select the interpreter as the Pico.
pipx install thonny - ampy if you like things to just run from the CLI: How to run a MicroPython script from a file on the Raspberry Pi Pico W from the command line?
Proxima Centauri Updated 2025-07-16
It is so close that we can notice its proper motion, and its distance to us will vary significantly across a few tens of thousands of years!
Program the Micro Bit in C Updated 2025-07-27
Official support is abysmal, very focused on MicroPython and their graphical UI.
The setup impossible to achieve as it requires setting up the Yotta, just like the impossible to setup Compile MicroPython code for Micro Bit locally on Ubuntu 22.04 with your own firmware setup.
So we just use github.com/lancaster-university/microbit-samples + github.com/carlosperate/docker-microbit-toolchain:.hex file size for the hello world was 447 kB, much better than the MicroPython hello world downloaded from the website which was about 1.8 MB!
docker pull ghcr.io/carlosperate/microbit-toolchain:latest
git clone https://github.com/lancaster-university/microbit-samples
cd microbit-samples
git checkout 285f9acfb54fce2381339164b6fe5c1a7ebd39d5
# Select a sample, builds one at a time. The default one is the hello world.
cp source/examples/hello-world/* source
# Build and flash.
docker run -v $(pwd):/home --rm ghcr.io/carlosperate/microbit-toolchain:latest yotta build
cp build/bbc-microbit-classic-gcc/source/microbit-samples-combined.hex "/media/$USER/MICROBIT/"If you try it again for a second time from a clean tree, it fails with:presumably because after Yotta died it started using GitHub as a registry... sad. When will people learn. Apparently we were at 5000 API calls per hour. But if you don't clean the tree, you will be just fine.
warning: github rate limit for anonymous requests exceeded: you must log in Meritocracy Updated 2025-07-16
Point groups in three dimensions Updated 2025-07-16
Point group Updated 2025-07-16
Point-contact transistor Updated 2025-07-16
As the name suggests, this is not very sturdy, and was quickly replaced by bipolar junction transistor.
Poincaré group Updated 2025-07-16
Full set of all possible special relativity symmetries:
In simple and concrete terms. Suppose you observe N particles following different trajectories in Spacetime.
There are two observers traveling at constant speed relative to each other, and so they see different trajectories for those particles:Note that the first two types of transformation are exactly the non-relativistic Galilean transformations.
- space and time shifts, because their space origin and time origin (time they consider 0, i.e. when they started their timers) are not synchronized. This can be modelled with a 4-vector addition.
- their space axes are rotated relative to one another. This can be modelled with a 4x4 matrix multiplication.
- and they are moving relative to each other, which leads to the usual spacetime interactions of special relativity. Also modelled with a 4x4 matrix multiplication.
The Poincare group is the set of all matrices such that such a relationship like this exists between two frames of reference.
Pokemon Updated 2025-07-16
One of the main children cartoons Ciro Santilli liked to watch. Part of the Pokemon Mania of the 90s of course.
Ciro could not understand why Nintendo won't make a proper 3D MMORPG Pokemon with actually 3D Pokemon roaming the land, which is obviously what everyone wants. There are even fan games getting there!until this explaiend it beautifully Video 1. "The Downfall Of Mainline Pokemon Games by GONZ media (2020)":
- pokemon-mmo-3d.com Interesting concept here, where when you deploy a Pokemon, you start controlling the Pokemon rather than the main character
- www.quora.com/Why-won-t-Nintendo-make-an-open-world-3D-Pokémon-RPG/answer/Ciro-Santilli
Platform game Updated 2025-07-16
Plane wave function Updated 2025-07-16
In this solution of the Schrödinger equation, by the uncertainty principle, position is completely unknown (the particle could be anywhere in space), and momentum (and therefore, energy) is perfectly known.
The plane wave function appears for example in the solution of the Schrödinger equation for a free one dimensional particle. This makes sense, because when solving with the time-independent Schrödinger equation, we do separation of variable on fixed energy levels explicitly, and the plane wave solutions are exactly fixed energy level ones.
Planck's law Updated 2025-07-16
Used to explain the black-body radiation experiment.
Published as: On the Theory of the Energy Distribution Law of the Normal Spectrum by Max Planck (1900).
The Quantum Story by Jim Baggott (2011) page 9 mentions that Planck apparently immediately recognized that Planck constant was a new fundamental physical constant, and could have potential applications in the definition of the system of units (TODO where was that published):This was a visionary insight, and was finally realized in the 2019 redefinition of the SI base units.
Planck wrote that the constants offered: 'the possibility of establishing units of length, mass, time and temperature which are independent of specific bodies or materials and which necessarily maintain their meaning for all time and for all civilizations, even those which are extraterrestrial and nonhuman, constants which therefore can be called "fundamental physical units of measurement".'
TODO how can it be derived from theoretical principles alone? There is one derivation at; en.wikipedia.org/wiki/Planck%27s_law#Derivation but it does not seem to mention the Schrödinger equation at all.
Planck-Einstein relation Updated 2025-07-16
There are unlisted articles, also show them or only show them.

