Circuit-based quantum computer Updated 2025-07-16
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Fabless semiconductor company Updated 2025-07-16
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CIA 2010 covert communication websites / Breakthroughs Updated 2025-07-16
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Some less-trivial breakthroughs:
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Software license that starts closed and becomes open once a certain amount of money is raised Updated 2025-07-16
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This is an interesting licensing model that might just scale.
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Software with bad user interface Updated 2025-07-16
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It is hard to pinpoint why, but the following useful software just feel bad for some reason:
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Stockfish CLI Updated 2025-10-14
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Most of what follows is part of the Universal Chess Interface. Tested on Ubuntu 22.10, Stockfish 14.1.
After starting stockfish on the command line, d (presumably display) contains:
 +---+---+---+---+---+---+---+---+
 | r | n | b | q | k | b | n | r | 8
 +---+---+---+---+---+---+---+---+
 | p | p | p | p | p | p | p | p | 7
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 6
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 5
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 4
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 3
 +---+---+---+---+---+---+---+---+
 | P | P | P | P | P | P | P | P | 2
 +---+---+---+---+---+---+---+---+
 | R | N | B | Q | K | B | N | R | 1
 +---+---+---+---+---+---+---+---+
   a   b   c   d   e   f   g   h

Fen: rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
Key: 8F8F01D4562F59FB
Sweet ASCII art. where:
Move white king's pawn from e2 to e4:
position startpos moves e2e4
Then display again:
d
gives:
 +---+---+---+---+---+---+---+---+
 | r | n | b | q | k | b | n | r | 8
 +---+---+---+---+---+---+---+---+
 | p | p | p | p | p | p | p | p | 7
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 6
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 5
 +---+---+---+---+---+---+---+---+
 |   |   |   |   | P |   |   |   | 4
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 3
 +---+---+---+---+---+---+---+---+
 | P | P | P | P |   | P | P | P | 2
 +---+---+---+---+---+---+---+---+
 | R | N | B | Q | K | B | N | R | 1
 +---+---+---+---+---+---+---+---+
   a   b   c   d   e   f   g   h

Fen: rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1
Key: B46022469E3DD31B
so we see that the pawn moved.
Now let's make Stockfish think for one second what is the next best move for black:
go movetime 1000
gives as the last line:
bestmove c7c5 ponder g1f3
TODO:
  • what is ponder? Something to do with thinking on the opponent's turn: permanent brain.
  • understand the previous lines
To make the move it as suggested for black, we have to either repeat the entire sequence of movements:
position startpos moves e2e4 c7c5
d:
 +---+---+---+---+---+---+---+---+
 | r | n | b | q | k | b | n | r | 8
 +---+---+---+---+---+---+---+---+
 | p | p |   | p | p | p | p | p | 7
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 6
 +---+---+---+---+---+---+---+---+
 |   |   | p |   |   |   |   |   | 5
 +---+---+---+---+---+---+---+---+
 |   |   |   |   | P |   |   |   | 4
 +---+---+---+---+---+---+---+---+
 |   |   |   |   |   |   |   |   | 3
 +---+---+---+---+---+---+---+---+
 | P | P | P | P |   | P | P | P | 2
 +---+---+---+---+---+---+---+---+
 | R | N | B | Q | K | B | N | R | 1
 +---+---+---+---+---+---+---+---+
   a   b   c   d   e   f   g   h

Fen: rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2
Key: 4CA78BCE9C2980B0
or alternatively we could also use the previous FEN notation as a starting point;
position fen rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1 moves c7c5
Note how the Universal Chess Interface interface is very simple: we just load a state and then decide what to do next for that one state. The engine holds only one and exactly one state at a time, and you can't even modify it differentially without loading new one from scratch.
Let's move white again with our brain with either:
position startpos moves e2e4 c7c5 d2d3
position fen rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2 moves d2d3
Set a specific position from fen:
position fen rnbqkbnr/pppppppp/8/8/4P3/8/PPPP1PPP/RNBQKBNR b KQkq - 0 1
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RNA-Seq Updated 2025-07-16
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Sequencing the DNA tells us what the organism can do. Sequencing the RNA tells us what the organism is actually doing at a given point in time. The problem is not killing the cell while doing that. Is it possible to just take a chunk of the cell to sequence without killing it maybe?
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Delft University of Technology Updated 2025-07-16
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Electric charge Updated 2025-07-16
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LibreTexts Updated 2025-07-16
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Follows the "certified teacher only" approach which is in Ciro Santilli's opinion a fatal flaw of most elearning systems out there, OurBigBook.com won't suffer from that!
But that is a very, very good project.
All notes appear to have been extracted from existing notes, as noted on the bottom of each page.
TODO how does it work exactly? Do they ask for permission from authors in every case, including when the content has open license? Or when it has open license, do they just do it? In some cases, the notes have no license, so they must have asked.
TODO what is the source code that authors write? LaTeX or something else? LaTeX feels extremely likely given that it is what most original materials were already written in.
They are attempting a "model up this entire university" thing: phys.libretexts.org/Courses which is good. E.g. they have a bunch of "quantum mechanics ones under: phys.libretexts.org/Bookshelves/Quantum_Mechanics
Appears to be UC Davies-based mostly.
They claim to use this closed source backend: www.nice.com/resources/cxone-expert-knowledge-management? Seriously? For a publicly funded project with low-tech requirements?? It is mind blowing.
Some issues:
OK let's database it:
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Logic gate Updated 2025-07-16
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Ohm Updated 2025-07-16
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Teach For All Updated 2025-07-16
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Eigenvalue Updated 2025-07-16
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Superconductor resistivity experiment video Updated 2025-07-16
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Video 1.
Superconductor, 4-probe measurement by Frederiksen Scientific A/S (2015)
Source. OK experiment, illustrates the educational kit they sell. No temperature control, just dumps liquid nitrogen into conductor and watches it drop. But not too bad either. The kit sale link is broken (obviously, enterprise stuff), but there are no archives unfortunately. But it must be some High-temperature superconductor
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Surely You're Joking, Mr. Feynman Updated 2025-07-16
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Solutions for the Schrodinger equation with multiple particles Updated 2025-07-16
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Bibliography:
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Parity violation Updated 2025-09-17
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This is quite mind blowing. The laws of physics actually differentiate between particles and antiparticles moving in opposite directions!!!
Only the weak interaction however does it of the fundamental interactions.
Some historical remarks on Surely You're Joking, Mr. Feynman section "The 7 Percent Solution".
It gets worse of course with CP Violation.
Video 1.
This Particle Breaks Time Symmetry by Veritasium
. Source.
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Partial derivative symbol Updated 2025-07-16
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Nope, it is not a Greek letter, notably it is not a lowercase delta. It is just some random made up symbol that looks like a letter D. Which is of course derived from delta, which is why it is all so damn confusing.
I think the symbol is usually just read as "D" as in "d f d x" for .
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Suwu herding sheep Updated 2025-07-16
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www.ibiblio.org/chinese-music/html/traditional.html contains an amazing orchestral version for di flute TODO identify! When attempting to upload to YouTube, it identifies as "Su Wu Tending the Sheep" and give a name "Chen Tao", but no further information. Chen Tao is presumably this dude: www.barduschinamusic.org/chen-tao-dizi | www.melodyofdragon.org/chentao.html 陈涛
baike.baidu.com/item/苏武牧羊/5532#11_2 mentions that it comes from an erhu concerto composed by Peng Xiuwen
The sadness of the erhu perfectly fits the role and mood of the story! Brilliant!
Video 1.
Suwu herding sheep played by Song Fei (2017)
Source.
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