From first principles Updated 2025-07-16
Los Alamos From Below by Richard Feynman (1975) Updated 2025-07-16
Amazing talk by Richard Feynman that describes his experiences at Los Alamos National Laboratory while developing the first nuclear weapons.
Transcript: calteches.library.caltech.edu/34/3/FeynmanLosAlamos.htm Also included full text into Surely You're Joking, Mr. Feynman.
- www.youtube.com/watch?v=uY-u1qyRM5w&t=2881s describes the computing aspects. Particularly interesting is the quote about how they used the typist secretary pool to emulate the IBM machines and debug their programs before the machines had arrived. This is exactly analogous to what is done in 2020 in the semiconductor industry, where slower models are used to estimate how future algorithms will run in future hardware.
Los Alamos From Below by Richard Feynman (1975)
Source. Polynomial over a ring Updated 2025-07-16
However, there is nothing in the immediate definition that prevents us from having a ring instead, i.e. a field but without the commutative property and inverse elements.
The only thing is that then we would need to differentiate between different orderings of the terms of multivariate polynomial, e.g. the following would all be potentially different terms:while for a field they would all go into a single term:so when considering a polynomial over a ring we end up with a lot more more possible terms.
If the ring is a commutative ring however, polynomials do look like proper polynomials: Section "Polynomial over a commutative ring".
Possible new effects in superconductive tunnelling Updated 2025-07-16
The inaugural that predicted the Josephson effect.
Published on Physics Letters, then a new journal, before they split into Physics Letters A and Physics Letters B. True Genius: The Life and Science of John Bardeen mentions that this choice was made rather than the more prestigious Physical Review Letters because they were not yet so confident about the results.
Video codec Updated 2025-11-18
GitHub's replacement of
master branch with main (2020) Updated 2025-07-16By GitHub around Black Lives Matter, due to a possible ludicrous relationship with slavery of black people:
For the love of God, the word "master" is much more general than black slavery. If you are going to ban it, you might as well ban the word "evil".
GitLab Updated 2025-07-16
See also: Ciro Santilli's minor projects.
Good video game to watch Updated 2025-07-16
Google X Updated 2025-07-16
Wikipedia reads:so basically exactly what Ciro Santilli wants to do on OurBigBook.com. Ominous.
Any contributor could create and own new Knol articles, and there could be multiple articles on the same topic with each written by a different author.
Like any closed source "failure", everything was deleted. wiki.archiveteam.org/index.php/Knol
History of special relativity Updated 2025-07-16
Bibliography:
- Subtle is the Lord by Abraham Pais (1982) chapter III "Relativity, the special theory" has a good sketch as you may imagine.
History of the United States Updated 2025-07-16
How can a chemical substance be unstable but not flammable? Updated 2025-07-16
How to store data in the Bitcoin blockchain Updated 2025-07-16
There are apparently two methods:
- in the script, e.g. as in the Genesis block message
- in output addresses
Specific implementations:
- eternitywall.it/ Eternity WallLaunched 2015 www.newsbtc.com/news/bitcoin/eternity-wall-records-1150-documents-blockchain-first-year/Shutdown sometime after 2019, working archive: web.archive.org/web/20190417074034/https://eternitywall.it/ says "Sorry, the service is not properly working at the moment..." and last working message timestamped "April 16, 2019 8:02 PM GMT".
How to teach Explain why the subject is beautiful Updated 2025-07-16
And if you really can't make money from a subject, there is only one other thing people crave: beauty.
You have to give the beauty motivations upfront, before boring people to death with endless prerequisites, otherwise no one will ever want to learn it.
PostgreSQL GIST Updated 2025-07-16
The highly underdocumented built-in module, that supports SQL spatial index and a lot more.
Quite horrendous as it only seems to work on geometric types and not existing columns. But why.
And it uses custom operatores, where standard operators would have been just fine for points...
Minimal runnable example with points:The index creation unfortunately took 100s, so it will not scale to 1B points very well whic his a shame.
set -x
time psql -c 'drop table if exists t'
time psql -c 'create table t(p point)'
time psql -c "insert into t select (point ('(' || generate_series || ',' || generate_series || ')')) from generate_series(1, 10000000)"
time psql -c 'create index on t using gist(p)'
time psql -c "select count(*) from t where p <@ box '(1000000,1000000),(9000000,2000000)'" Hydrogen line Updated 2025-07-16
Hypercube Updated 2025-07-16
Convex hull of all (Cartesian product power) D-tuples, e.g. in 3D:
( 1, 1, 1)
( 1, 1, -1)
( 1, -1, 1)
( 1, -1, -1)
(-1, 1, 1)
(-1, 1, -1)
(-1, -1, 1)
(-1, -1, -1) Kudos Updated 2025-07-16
Ahh, Ciro Santilli was certain this was some slang neologism, but it is actually Greek! So funny. Introduced into English in the 19th century according to: www.merriam-webster.com/dictionary/kudo.
is by far the most important of because it is quantum mechanics states live, because the total probability of being in any state has to be 1!
has some crucially important properties that other don't (TODO confirm and make those more precise):
- it is the only that is Hilbert space because it is the only one where an inner product compatible with the metric can be defined:
- Fourier basis is complete for , which is great for solving differential equation
Laplacian in Einstein notation Updated 2025-07-16
There are unlisted articles, also show them or only show them.