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
PostgreSQL serialization failure Updated 2025-07-16
When using SQL REPEATABLE READ isolation level and SQL SERIALIZABLE isolation level, concurrent transactions may fail with a serialization failure, and then you might need to retry them. You server code or your ORM must always account for that.
Related questions:
- stackoverflow.com/questions/7705273/what-are-the-conditions-for-encountering-a-serialization-failure
- stackoverflow.com/questions/59351109/error-could-not-serialize-access-due-to-concurrent-update
- stackoverflow.com/questions/50797097/postgres-could-not-serialize-access-due-to-concurrent-update/51932824
Signal (software) Updated 2025-09-09
Basic must haves:
Other cool stuff:
- sealed sender: signal.org/blog/sealed-sender/ Nice!
TODO what's the fucking official discussion/feature request forum?
- community.signalusers.org appears to be the de-facto non-official one.
- github.com/signalapp/Signal-Android/issues/5372
- whispersystems.discoursehosting.net
- github.com/signalapp/Signal-Desktop/issues/1318 closes and points to discoursehosting
- github.com/signalapp/Signal-Desktop/issues/549
- www.reddit.com/r/signal/comments/lipo6z/community_signal_forum_vs_reddit/ gives some good history, says they pay for community.signalusers.org/ and have admin powers there.
Silicon Graphics Updated 2025-07-16
This company is a bit like Sun Microsystems, you can hear a note of awe in the voice of those who knew it at its peak. This was a bit before Ciro Santilli's awakening.
Both of them and Sun kind of died in the same way, unable to move from the workstation to the personal computer fast enough, and just got killed by the scale of competitors who did, notably Nvidia for graphics cards.
Some/all Nintendo 64 games were developed on it, e.g. it is well known that this was the case for Super Mario 64.
Silicon Graphics Promo (1987)
Source. Highlights that this was one of the first widely available options for professional engineers/designers to do real-time 3D rendering for their designs. Presumably before it, you had to do use scripting to CPU render and do any changes incrementally by modifying the script. Silicon photonics Updated 2025-07-16
- youtu.be/29aTqLvRia8?t=714 GlobalFoundries seems to be one of the leaders at the time. E.g. quantum computing company PsiQuantum uses them. Part of this was from acquiring IBM's microelectronics division in 2014.
- youtu.be/t0yj4hBDUsc?t=566 mentions the paper Deep learning with coherent nanophotonic circuits
- youtu.be/t0yj4hBDUsc?t=440 block diagram
- youtu.be/t0yj4hBDUsc?t=456 Lightmatter lightmatter.co/ seems to be using an in-silicon Mach-Zehnder interferometer to do analog matrix multiplication with light. It is an actual analog computer element!
Silicon Photonics for Extreme Computing by Keren Bergman (2017)
Source. Limtless (2011) Updated 2025-07-16
That makes Ciro Santilli most mad about this film is the fact that the dude was passionate about writing, and when he became a genius, rather than write the best novels ever written, he decided instead to play the stock market instead. This paints an accurate picture of 2020's society, where finance jobs make infinitely more money than other real engineering jobs, and end up attracting much of the talent.
Another enraging thing is how his girlfriend starts liking him again once he is a genius, and instead of telling her to fuck off, he stays with her.
The other really bad thing is the ending. He fixed the drug by himself? He scared off De Niro just like that?
Silicon Valley (TV series) Updated 2025-07-16
Loop-mediated isothermal amplification Updated 2025-07-16
Like PCR, but does not require thermal cycling. Thus the "isothermal" in the name: iso means same, so "same temperature".
Not needing the thermo cycling means that the equipment needed is much smaller and cheaper it seems.
Lost Horse LLC Updated 2025-07-16
www.irishtimes.com/life-and-style/people/mackenzie-scott-how-the-former-mrs-bezos-became-a-philanthropist-like-no-other-1.4850049 MacKenzie Scott: How the former Mrs Bezos became a philanthropist like no other (2020) has some good mentions:
But as Scott's fame for giving away money has grown, so too has the deluge of appeals for gifts from strangers and old friends alike. That clamour may have driven Scott's already discreet operation further underground, with recent philanthropic announcements akin to sudden lightning bolts for unsuspecting recipients.
Lowering and raising Updated 2025-07-16
Metallurgical Laboratory Updated 2025-07-16
The lab that made Chicago Pile-1, located in the University of Chicago. Metallurgical in this context basically as in "working with the metals uranium and plutonium".
Given their experience, they also designed the important X-10 Graphite Reactor and the B Reactor which were built in other locations.
Momentum operator Updated 2025-07-16
In three dimensions In position representation, we define it by using the gradient, and so we see that
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