I caught and overcame a minor addiction to Cataclysm: Dark Days Ahead.
It does bring back the The Sims feeling from my teenage years, but with killer zombies added in.
I especially like going to sleep in that game, and how you need to setup a confy bed for it.
Some further comments at: Section "Cataclysm: Dark Days Ahead".
The way to quit is simple: delete your saves, then get annoyed with slowness of progressing back up, then use built-in debug/cheat menu to overcome that, then it's not fun anymore. This is a major advantage of single player open source games: addiction resistance!
Before
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After
. Added font awesome icons. github.com/ourbigbook/ourbigbook/issues/151
Didn't manage to subset, but so be it for now: stackoverflow.com/questions/62395038/how-can-i-export-only-one-character-from-ttf-woff-file-to-avoid-load-unnecessa/71197892#71197892
A disaster. More cars and less trains...
Bibliograpy:
- Losing Track by Channel 4 (1984), especially episode 5
- www.theguardian.com/uk/2013/mar/02/beeching-wrong-about-britains-railwaysToday the makeup of UK transport looks very different from the one envisaged by Dr Beeching. Rail passenger figures have almost doubled over the past 10 years; commuter trains are crammed; young people are deserting the car for the train; and Britain's railway bosses are struggling to meet soaring demands for seats. The legacy of Beeching - dug-up lines, sold-off track beds and demolished bridges - has only hindered plans to revitalise the network, revealing the dangers of having a single, inflexible vision when planning infrastructure."The crucial lesson to take from the Beeching anniversary is that you have to be flexible when planning transport infrastructure. Beeching was not," says Colin Divall, professor of rail history at York University. "Yes, many loss-making lines did need closing down, but nowhere near the number earmarked by Beeching, as we can now see with terrible hindsight."
Most commonly known as a byproduct radioactive decay.
Their energy is very high compared example to more common radiation such as visible spectrum, and there is a neat reason for that: it's because the strong force that binds nuclei is strong so transitions lead to large energy changes.
A decay scheme such as Figure "caesium-137 decay scheme" illustrates well how gamma radiation happens as a byproduct of radioactive decay due to the existence of nuclear isomer.
Gamma rays are pretty cool as they give us insight into the energy levels/different configurations of the nucleus.
They have also been used as early sources of high energy particles for particle physics experiments before the development of particle accelerators, serving a similar purpose to cosmic rays in those early days.
But gamma rays they were more convenient in some cases because you could more easily manage them inside a laboratory rather than have to go climb some bloody mountain or a balloon.
The positron for example was first observed on cosmic rays, but better confirmed in gamma ray experiments by Carl David Anderson.
See also: e-learning website.
After something broke on the website due to SQLite vs PostgreSQL inconsistencies and took me a day to figure it out, I finally decided to update the test system so that
OURBIGBOOK_POSTGRES=true npm test will run the tests on PostgreSQL.Originally, these were being run only on SQLite, which is the major use case for OurBigBook CLI, which came before the website.
But the website runs on PostgreSQL, so it is fundamental to test things in PostgreSQL as well.
We know that superfluidity happens more easily in bosons, and so electrons joins in Cooper pairs to form bosons, making a superfluid of Cooper pairs!
Isn't that awesome!
The Busy beaver scale allows us to gauge the difficulty of proving certain (yet unproven!) mathematical conjectures!
To to this, people have reduced certain mathematical problems to deciding the halting problem of a specific Turing machine.
A good example is perhaps the Goldbach's conjecture. We just make a Turing machine that successively checks for each even number of it is a sum of two primes by naively looping down and trying every possible pair. Let the machine halt if the check fails. So this machine halts iff the Goldbach's conjecture is false! See also Conjecture reduction to a halting problem.
Therefore, if we were able to compute , we would be able to prove those conjectures automatically, by letting the machine run up to , and if it hadn't halted by then, we would know that it would never halt.
Of course, in practice, is generally uncomputable, so we will never know it. And furthermore, even if it were computable, it would take a lot longer than the age of the universe to compute any of it, so it would be useless.
However, philosophically speaking at least, the number of states of the equivalent Turing machine gives us a philosophical idea of the complexity of the problem.
The busy beaver scale is likely mostly useless, since we are able to prove that many non-trivial Turing machines do halt, often by reducing problems to simpler known cases. But still, it is cute.
But maybe, just maybe, reduction to Turing machine form could be useful. E.g. The Busy Beaver Challenge and other attempts to solve BB(5) have come up with large number of automated (usually parametrized up to a certain threshold) Turing machine decider programs that automatically determine if certain (often large numbers of) Turing machines run forever.
So it it not impossible that after some reduction to a standard Turing machine form, some conjecture just gets automatically brute-forced by one of the deciders, this is a path to
How a quartz watch works by Steve Mould (2017)
Source. Mentions feedback loop loop with the quartz tuning fork for the piezoelectricity and an amplifier. Also mentions the choice of 32768 Hertz () as the first power of 2 that is outside of the human hearing range, and then how a frequency divider is used to reduce the frequency to get the second counter.You are nothing but useless leeches in the Internet age.
You must go bankrupt all of you, ASAP.
Research paid with taxpayer money must be made available for free.
Researchers and reviewers all work for peanuts, while academic publishers get money for doing the work that an algorithm could do. OurBigBook.com.
When Ciro learned URLs such as www.nature.com/articles/181662a0 log you in automatically by IP, his mind blew! The level of institutionalization of this theft is off the charts! The institutionalization of theft is also clear from article prices, e.g. 32 dollars for a 5 page article.
Long live the Guerilla Open Access Manifesto by Aaron Swartz (2008).
Key physics papers from the 50's are still copyright encumbered as of 2020, see e.g. Lamb-Retherford experiment. Authors and reviewers got nothing for it. Something is wrong.
Infinite list of other people:
- blog.machinezoo.com/public-domain-theft by Robert Važan:
Scientific journals are perhaps one of the most damaging IP rackets. Scientists are funded by governments to do research and publish papers. Reviews of these papers are done by other publicly funded scientists. Even paper selection and formatting for publication is done by scientists. So what do journals actually do? Nearly nothing.
Discovered in 1988, the first high-temperature superconductor which did not contain a rare-earth element.
Cross files references to IDs: yes. But no check by default for duplicates when doing automatic ID from title. Just automatically disambiguates with
-1, -2 suffixes, and links take the last one available.Source page splitting: splits at h2 by default. If configurable, likely always af fixed level?
Has some nice image generation from inline code from standard R plotting functions.
Hello world documented at: bookdown.org/yihui/bookdown/get-started.html
Hello world on Ubuntu 23.04 after installing R:The build CLI comes from: stackoverflow.com/questions/50888871/how-to-use-rscript-command-line-tool-to-build-a-book-in-bookdown
sudo R -e 'install.packages("bookdown")'
git clone https://github.com/rstudio/bookdown-demo
cd bookdown-demo
Rscript -e 'bookdown::render_book("index.Rmd")'
xdg-open _book/index.htmlThe installatoin
Rscript -e 'bookdown::render_book("index.Rmd")' takes several minutes, it compiles a bunch of stuff from source apparently. but it did work.Ultimate explanation: math.stackexchange.com/questions/776039/intuition-behind-normal-subgroups/3732426#3732426
Only normal subgroups can be used to form quotient groups: their key definition is that they plus their cosets form a group.
Intuition:
One key intuition is that "a normal subgroup is the kernel" of a group homomorphism, and the normal subgroup plus cosets are isomorphic to the image of the isomorphism, which is what the fundamental theorem on homomorphisms says.
Therefore "there aren't that many group homomorphism", and a normal subgroup it is a concrete and natural way to uniquely represent that homomorphism.
The best way to think about the, is to always think first: what is the homomorphism? And then work out everything else from there.
Interesting to note that there are quite a few nearer than Sagittarius A, as of 2022 we know of one at 1.5 kly: universemagazine.com/en/discovered-the-closest-black-hole-to-the-sun/
It is interesting that a few months earlier there seemed to be no known specific black holes in the Milky Way: www.nasa.gov/feature/goddard/2022/hubble-determines-mass-of-isolated-black-hole-roaming-our-milky-way-galaxy although their count is estimated to be in the hundreds of millions.
Some people from them contacted Ciro Santilli after Ciro's initial publishing of CIA 2010 covert communication websites.
After a quick Discord chat with them, it was apparent that these people were really cool and knowledgeable.
Also many of them seem to think university is broken and just go hack straigh away.
A perfect example of a dojo learning model.
Also they don't seem to need sleep. Go figure!
With pepole like this, there's hope for Brazil: Section "What poor countries have to do to get richer".
The fact that ATP is the universal energy storage mollecule of all life on Earth is such an incredible unifying principle of biology!
It is the direct output of all the major forms of "energy generation" in cells: ATP synthesis mechanism.
It is just as fundamental as the genetic code for example.
No wonder dozens of Nobel Prizes were related to its discovery, given its complexity.
There are two ways to organize a project:
- linear history
- branched history: history with merge commits
Some people like merges, but they are ugly and stupid. Rebase instead and keep linear history.
Linear history:
5 master
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4
|
3
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2
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1 first commitBranched history:
7 master
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| \
6 \
|\ \
| | |
3 4 5
| | |
| / /
|/ /
2 /
| /
1/ first commitHere commits 6 and 7 are the so called "merge commits":
- they have multiple parents:
- 6 has parents 3 and 4
- 7 has parents 5 and 6
- they are useless and don't contain any real information
Which type of tree do you think will be easier to understand and maintain?
????
????????????
You may disconnect now if you still like branched history.
These examples are written in the Sequelize library using raw queries.
Sequelize is used minimally, just to feed raw queries in transparently to any underlying database, and get minimally parsed results out for us, which we then assert with standard JavaScript. The queries themselves are all written by hand.
By default the examples run on SQLite. Just like the examples from sequelize example, you can set the database at runtime as:
./index.jsor./index.js l: SQLite./index.js p: PostgreSQL. You must manually create a database calledtmpand ensure that peer authentication works for it
Here we list only examples which we believe are standard SQL, and should therefore work across different SQL implementations:
- nodejs/sequelize/raw/index.js: basic hello world to demonstrate the setup and very simple functionality
- nodejs/sequelize/raw/many_to_many.js: illustrates many-to-many relations with JOIN. Contains:
- SQL transaction examples:
- nodejs/sequelize/raw/commit_error.js: stackoverflow.com/questions/27245101/why-should-we-use-rollback-in-sql-explicitly/27245234#27245234 and stackoverflow.com/questions/48277519/how-to-use-commit-and-rollback-in-a-postgresql-function/48277708#48277708 suggest that on PostgreSQL, once something fails inside a transaction, all queries in the current transaction are ignored, and
COMMITsimply does aROLLBACK. Let's check. Yup, true for Postgres, but false for SQLite, SQLite just happily runs anything it can, you really needROLLBACKfor it. - SQL isolation level example
- nodejs/sequelize/raw/commit_error.js: stackoverflow.com/questions/27245101/why-should-we-use-rollback-in-sql-explicitly/27245234#27245234 and stackoverflow.com/questions/48277519/how-to-use-commit-and-rollback-in-a-postgresql-function/48277708#48277708 suggest that on PostgreSQL, once something fails inside a transaction, all queries in the current transaction are ignored, and
- GROUP BY and SQL aggregate functions:
- nodejs/sequelize/raw/group_by_extra_column.js: let's see if it blows up or not on different DB systems,
sqlite3Node.js package allows it:- github.com/sequelize/sequelize/issues/5481#issuecomment-964387232
- dba.stackexchange.com/questions/141594/how-select-column-does-not-list-in-group-by-clause/141600 says that it was allowed in SQL:1999 when there are no ambiguities due to constraints, e.g. when grouping by unique columns
- github.com/postgres/postgres/blob/REL_13_5/src/test/regress/sql/functional_deps.sql#L27 shows that PostgreSQL wants it to work for
UNIQUE NOT NULL, but they just haven't implemented it as of 13.5, where it only works if you group byPRIMARY KEY - dba.stackexchange.com/questions/158015/why-can-i-select-all-fields-when-grouping-by-primary-key-but-not-when-grouping-b also says that
UNIQUE NOT NULLdoesn't work. Dan Lenski then points to rationale mailing list thread:
- nodejs/sequelize/raw/group_by_max_full_row.js: here we try to get the full row of each group at which a given column reaches the max of the group
- Postgres: has
SELECT DISCINTCT ONwhich works perfectly if you only want one row in case of multiple rows attaining the max.ONis an extension to the standard unfortunately: www.postgresql.org/docs/9.3/sql-select.html#SQL-DISTINCT Docs specify that it always respectsORDER BYwhen selecting the row.- stackoverflow.com/questions/586781/postgresql-fetch-the-row-which-has-the-max-value-for-a-column asks it without the multiple matches use case
- stackoverflow.com/questions/586781/postgresql-fetch-the-rows-which-have-the-max-value-for-a-column-in-each-group/587209#587209 also present in simpler form at stackoverflow.com/questions/121387/fetch-the-rows-which-have-the-max-value-for-a-column-for-each-distinct-value-of/123481#123481 gives a very nice OUTER JOIN only solution! Incredible, very elegant.
- dba.stackexchange.com/questions/171938/get-only-rows-with-max-group-value asks specifically the case of multiple matches to the max
- stackoverflow.com/questions/586781/postgresql-fetch-the-row-which-has-the-max-value-for-a-column asks it without the multiple matches use case
- SQLite:
- stackoverflow.com/questions/48326957/row-with-max-value-per-group-sqlite
- stackoverflow.com/questions/48326957/row-with-max-value-per-group-sqlite/48328243#48328243 teaches us that in SQLite min and max are magic and guarantee that the matching row is returned
- stackoverflow.com/questions/48326957/row-with-max-value-per-group-sqlite/72996649#72996649 Ciro Santilli uses the magic of
ROW_NUMBER
- stackoverflow.com/questions/17277152/sqlite-select-distinct-of-one-column-and-get-the-others/71924314#71924314 get any full row without specifying which, we teach how to specify
- code.djangoproject.com/ticket/22696 WONTFIXed
DISTINCT ON- stackoverflow.com/questions/50846722/what-is-the-difference-between-postgres-distinct-vs-distinct-on/72997494#72997494
DISTINCTvsDISTINCT ON, somewhat related question
- stackoverflow.com/questions/50846722/what-is-the-difference-between-postgres-distinct-vs-distinct-on/72997494#72997494
- stackoverflow.com/questions/48326957/row-with-max-value-per-group-sqlite
- stackoverflow.com/questions/5803032/group-by-to-return-entire-row asks how to take the top N with distinct after order limit. I don't know how to do it in Postgres
- Postgres: has
- nodejs/sequelize/raw/most_frequent.js: illustrates a few variants of findind the mode, including across GROUP
- nodejs/sequelize/raw/group_by_max_n.js: get the top N in each group
- nodejs/sequelize/raw/group_by_extra_column.js: let's see if it blows up or not on different DB systems,
- order results in the same order as
IN: - LIMIT by a running total: TODO links
There are unlisted articles, also show them or only show them.